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prof. Ing. Jan Holub, Ph.D.

Všechny publikace

Cepstral Coefficients Effectiveness for Gunshot Classifying

  • DOI: 10.1088/1361-6501/ad3c5d
  • Odkaz: https://doi.org/10.1088/1361-6501/ad3c5d
  • Pracoviště: Katedra měření
  • Anotace:
    This paper analyses the efficiency of various frequency cepstral coefficients (fCC) in a non-speech application, specifically in classifying acoustic impulse events - gunshots. There are various methods for such event identification available. The majority of these methods are based on time or frequency domain algorithms. However, both of these domains have their limitations and disadvantages. In this article, an fCC, combining the advantages of both frequency and time domains, is presented and analyzed. These originally speech features showed potential not only in speech-related applications but also in other acoustic applications. The comparison of the classification efficiency based on features obtained using four different fCC, namely Mel-frequency Cepstral Coefficients (MFCC), Inverse Mel-frequency Cepstral Coefficients (IMFCC), Linear-frequency Cepstral Coefficients (LFCC), and Gammatone-frequency Cepstral Coefficients (GTCC) is presented. An optimal frame length for an fCC calculation is also explored. Various gunshots from short guns and rifle guns of different calibers and multiple acoustic impulse events, similar to the gunshots, to represent false alarms are used. More than six hundred acoustic events records have been acquired and used for training and validation of two designed classifiers, Support Vector Machine, and Neural Network. Accuracy, Recall and Matthew's correlation coefficient measure the classification success rate. The results reveal the superiority of GFCC to other analyzed methods.

A Novel Method of Subjective Sound and Audio Playback User Experience Evaluation in Multitasking Context: Two Case Studies

  • Autoři: prof. Ing. Jan Holub, Ph.D., Kowalczuk, Y., Schaefer, M., Reimes, J.
  • Publikace: Human Interaction & Emerging Technologies: Artificial Intelligence & Future Applications Proceedings of the 7th International Conference on Human Interaction and Emerging Technologies, IHIET-AI 2022, April 21–23, 2022, Lausanne, Switzerland, Eds. T. Ahram and R. Taiar, AHFE International, Apr 22, 2022 - Technology & Engineering - 854 pages.. Basel: Springer Nature Switzerland AG, 2022. ISSN 2771-0718. ISBN 978-1-7923-8989-4.
  • Rok: 2022
  • DOI: 10.54941/ahfe100890
  • Odkaz: https://doi.org/10.54941/ahfe100890
  • Pracoviště: Katedra měření
  • Anotace:
    Present-day telecommunication devices are rarely utilized by comfortably seated users who do not perform any other parallel task. The typical communication scenario includes walking, driving a car, watching TV, working on a PC, etc., during a conversation. However, transmission quality evaluation has traditionally taken place in ideal laboratory conditions. The authors of this paper have prepared a new standard for subjective transmission quality testing with a parallel task that has been approved as ETSI TR 103 503. The paper summarizes the most widely-used transmission quality testing methods, discusses their disadvantages, and in-troduces a new testing methodology with a parallel task. It also presents two ex-periments performed in parallel task scenarios and highlights some differences in human perception in these scenarios.

How the COVID-19 Changed the Hands-on Laboratory Classes of Electrical Measurement

  • DOI: 10.21014/actaimeko.v11i4.1301
  • Odkaz: https://doi.org/10.21014/actaimeko.v11i4.1301
  • Pracoviště: Katedra měření
  • Anotace:
    This article depicts how COVID-19 affected practical teaching at Czech Technical University in Prague, Faculty of Electrical Engineering, Department of Measurement. It introduces the subject of Electrical Measurement and its hands-on laboratory classes. The course applies to more than 100 undergraduate students per semester. Since COVID-19 mainly affected the teaching of the hands-on laboratory courses, the article narrates how the COVID-19 lockdown has changed classes. An experience with the rapid transformation of lectures during the lockdown focusing on the hands-on laboratory classes is discussed, and the improvements that have been done to preserve its objectives, but also to adapt them to another possible lockdown, and the need to switch to the distance teaching, is revealed. The changes have been inspired by the results of a survey carried out among more than 250 students. The outline of the laboratory tasks transformation with an emphasis on the possibility of switching the real face-to-face measurement to the distance teaching remote lectures is described. The change includes reducing the number of laboratory tasks taught while preserving most of the objectives. All 11 new laboratory tasks are described in detail, and it is discussed how the possible change from hands-on to remote classes will affect every task.

Increasing of Sampling Rate of Internal ADC in Microcontrollers by Equivalent-Time Sampling

  • Pracoviště: Katedra měření
  • Anotace:
    The paper describes the Equivalent-Time Sampling (ETS) in Software-Defined Instruments (SDI) - typically oscilloscopes. It introduces a possible solution of the microcontrollers drawback caused by the maximal sampling frequency and its limitations in digitizing quick transient responses. The principle of ETS used in microcontrollers is explained, and the jitter effect is taken into account. Analog-to-digital converter input model and real properties of software-defined oscilloscope from ETS point of view are introduced and explained. In the system for circuit behavior analysis as a step response, where a microcontroller with internal peripherals (pulse-width modulation and analog-to-digital converter) is used for a test signal generation and data digitization, the use of ETS may increase the equivalent sampling rate of the internal analog-to-digital converter up to tens of MSa/s.

Online Teaching of Practical Classes Under the Covid-19 Restrictions

  • DOI: 10.1016/j.measen.2022.100378
  • Odkaz: https://doi.org/10.1016/j.measen.2022.100378
  • Pracoviště: Katedra měření
  • Anotace:
    COVID -19 pandemic and its restrictions bring new challenges to all aspects and phases of higher education. At universities, new remote formats have been developed and deployed for lectures and laboratory exercises. This article addresses challenges and introduces the new experience with lectures and laboratory classes during the pandemic time at the Department of Measurement of the Czech Technical University in Prague, Faculty of Electrical Engineering. Based on the student survey of more than 250 students describes the possibilities of how to adapt the lectures during the lockdown. The article also introduces the Home Lab, a tool developed in the department that helps in distance teaching practical electronic classes. Home Lab includes two parts with functional groups, a Laboratory Experimental Device and a System of Measurement Instruments. The article also shows the opportunity for suitable remote exercises and variants of circuits that can be easily assembled and measured using Software Defined Instrument based on various microcontrollers. A detailed description of all Software Defined Instruments is also present. During the Pandemic, the home lab model was successfully practically verified during distance learning in three subjects, with more than 150 students per semester. It has also been shown that the Home Lab can be successfully deployed for a semester project. The article also presents experience with the teaching software-oriented courses. At the end of the article, practical knowledge and an experience from distance teaching during a three-semester lockdown are shared.

Subjective Influence of Camera-Gaze Angular Offset

  • Autoři: prof. Ing. Jan Holub, Ph.D., Isabelle, S., Krylová, A., Avetisyan, H.
  • Publikace: IEEE Access. 2022, 10(1), 9321-9327. ISSN 2169-3536.
  • Rok: 2022
  • DOI: 10.1109/ACCESS.2022.3143814
  • Odkaz: https://doi.org/10.1109/ACCESS.2022.3143814
  • Pracoviště: Katedra měření
  • Anotace:
    The study aimed to evaluate the difficulty in maintaining eye contact during a teleconference for different camera-gaze angular offsets. Videoconferencing systems may compromise the eye contact between participants due to imperfect angular alignment between the center of the screen and the camera. During a teleconference, difficulty maintaining eye contact may be perceived as uncomfortable or unsatisfying by participants in the call. An experiment deploying 33 test subjects was performed and evaluated. Groups of three test subjects performed a videoconference call. The effect of camera-gaze angular offset was quantified by assessing Effectiveness and Engagement ratings. It was shown that even 10 degrees of misalignment cause a statistically significant drop in Effectiveness for business-type teleconference calls. Camera-gaze angular offset is an important parameter to be considered during videoconferencing equipment design or setup. Higher misalignments may cause significant drops in perceived call quality (Quality of Experience). Our research results can be practical in conferencing equipment design and setup, modern telecommunication equipment design, workplace ergonomics, or distance learning equipment setup.

Evaluation of Digital Watermarking on Subjective Speech Quality

  • DOI: 10.1038/s41598-021-99811-x
  • Odkaz: https://doi.org/10.1038/s41598-021-99811-x
  • Pracoviště: Katedra měření
  • Anotace:
    New methods of securing the distribution of audio content have been widely deployed in the last twenty years. Their impact on perceptive quality has, however, only been seldomly the subject of recent extensive research. We review digital speech watermarking state of the art and provide subjective testing of watermarked speech samples. Latest speech watermarking techniques are listed, with their specifics and potential for further development. Their current and possible applications are evaluated. Open-source software designed to embed watermarking patterns in audio files is used to produce a set of samples that satisfies the requirements of modern speech-quality subjective assessments. The patchwork algorithm that is coded in the application is mainly considered in this analysis. Different watermark robustness levels are used, which allow determining the threshold of detection to human listeners. The subjective listening tests are conducted following ITU-T P.800 Recommendation, which precisely defines the conditions and requirements for subjective testing. Further analysis tries to determine the effects of noise and various disturbances on watermarked speech’s perceived quality. A threshold of intelligibility is estimated to allow further openings on speech ompression techniques with watermarking. The impact of language or social background is evaluated through an additional experiment involving two groups of listeners. Results show significant robustness of the watermarking implementation, retaining both a reasonable net subjective audio quality and security attributes, despite mild levels of distortion and noise. Extended experiments with Chinese listeners open the door to formulate a hypothesis on perception variations with geographical and social backgrounds.

Metody Výuky Praktických Předmětů na Katedře Měření FEL ČVUT v Době Covidu

  • Pracoviště: Katedra měření
  • Anotace:
    Pandemie COVID-19 prakticky přes noc dramaticky změnila nebo dokonce dočasně zastavila výuku na mnoha univerzitách. Tato situace byla výzvou zejména pro technické univerzity s původně spoustou praktických činností a laboratorních cvičení, protože vyžadovala vytvoření stabilního a plnohodnotného online vzdělávacího systému. Vše, co dosud probíhalo formou přímého kontaktu, od samotných přednášek, seminářů, praktických ukázek a laboratorních cvičení, přes písemné testy až po ústní zkoušky, bylo nutné převést do digitální podoby, o dalších právních a administrativních procesech pro zajištění výuky nemluvě. Významnou výhodou FEL ČVUT bylo, že drtivá většina pedagogů již měla předchozí zkušenosti s poskytováním online vzdělávání a disponovala řadou nástrojů, které bylo možné k tomuto účelu použít. Rychlý přechod z prezenční formy studia na distanční nicméně vyžadoval přehodnocení koncepce organizace výuky a zajištění řady souvisejících činností, zejména v oblasti komunikace, plánování vzdělávacích aktivit a výběru vhodných metod.

Online teaching at CTU in Prague aka university under COVID restrictions

  • DOI: 10.1016/j.measen.2021.100121
  • Odkaz: https://doi.org/10.1016/j.measen.2021.100121
  • Pracoviště: Katedra měření
  • Anotace:
    Covid-19 related restrictions bring new challenges to all aspects and phases of higher education. At universities, new remote formats are deployed or even developed both for lectures and laboratory exercises. This article addresses new challenges and describes the experience with lessons during the pandemic time at the Department of Measurement of the Czech Technical University in Prague, Faculty of Electrical Engineering. It introduces the best practices exercised using the Home Lab, which helps in distance teaching of practical electronic classes. Home Lab includes two models with functional groups, a Laboratory Experimental Device and System of Measurement Instruments. The article also shows the possibilities of suitable remote exercises and variants of circuits that can be easily assembled and measured using Software Defined Instrument based on STM microcontrollers. During the pandemic, the home lab model was successfully practically verified during distance learning in three classes, with more than 150 students. The article also presents experience with the teaching of software-oriented courses. At first glance, their transformation can be viewed as straightforward. However, practical realization reveals few remarkable details.

Subjective Video QoE with a Hybrid Cognitive-motor Task

  • Autoři: prof. Ing. Jan Holub, Ph.D., Avetisyan, H., Lima, P.-V.
  • Publikace: IEEE Access. 2021, 9 109605-109611. ISSN 2169-3536.
  • Rok: 2021
  • DOI: 10.1109/ACCESS.2021.3101288
  • Odkaz: https://doi.org/10.1109/ACCESS.2021.3101288
  • Pracoviště: Katedra měření
  • Anotace:
    This paper reports on the subjective video quality analysis with and without a parallel task. It aims to understand how the quality perceived by the human observer brain is affected when the subject is not entirely focused on the judgment task. For this purpose, two subjective video quality tests were performed according to the ITU-T P.910 recommendation - Subjective video quality assessment methods for multimedia applications. They consisted of two parts involving a total of 24 subjects. Unlike the first test, the second test included an additional (parallel) psychomotor task where subjects had to sort different colors of pasta into three bowls. Various analyses were provided, including preliminary analysis, group analysis, and RMSE analysis. Surprisingly, the results show that not all the spectrum of quality is affected equally by parallel task introduction.

System for an Acoustic Detection, Localization and Classification

  • DOI: 10.21014/acta_imeko.v10i2.1041
  • Odkaz: https://doi.org/10.21014/acta_imeko.v10i2.1041
  • Pracoviště: Katedra měření
  • Anotace:
    At present, acoustic detection techniques of gunshots (gunshot detection and its classification) are increasingly being used not only for military applications but also for civilian purposes. Detection, localization, and classification of a dangerous event such as gunshots employing acoustic detection is a perspective alternative to visual detection, which is commonly used. In certain situations, to detect and localize a source of a gunshot, an automatic acoustic detection system, which can classify the caliber, may be preferable. This paper presents a system for acoustic detection, which can detect, localize and classify acoustic events such as gunshots. The system has been tested in open and closed shooting ranges and tested firearms are 9 mm short gun, 6.35 mm short gun, .22 short gun, and .22 rifle gun with various subsonic and supersonic ammunition. As “false alarms,” sets of different impulse acoustic events like door slams, breaking glass, etc. have been used. Localization and classification algorithms are also introduced. To successfully classify the tested acoustic signals, Continuous Wavelet and Mel Frequency Transformation methods have been used for the signal processing, and the fully two-layer connected neural network has been implemented. The results show that the acoustic detector can be used for reliable gunshot detection, localization, and classification.

The Improved Automatic Control Points Computation for the Acoustic Noise Level Audits

  • DOI: 10.21014/acta_imeko.v10i3.1067
  • Odkaz: https://doi.org/10.21014/acta_imeko.v10i3.1067
  • Pracoviště: Katedra měření
  • Anotace:
    The acoustic noise level in the interior is one of the quantities specified by a standard and is subject to audits to ensure a comfortable living environment. Currently, the noise level audits are performed manually by a skilled operator, who evaluates the floor plan and uses it to calculate the control points location in which the measurement is performed. The computation is proposed to automate the audit by formulating an optimisation problem for which an algorithm was designed. The algorithm computes the solution that satisfies all constraints specified in the standard, for example, the minimum distance among the control points and fixed obstacles (walls or columns). In the proposed optimisation problem, the fitness function was designed based on the measurement purpose, and two typical use-cases were analysed: (i) long-term stationary noise measurement and (ii) recurring short-term noise measurement. Although the set of control points for both use cases complies with the given standard, it is beneficial to distinguish the location of control points based on the measurement purpose. The number of control points is maximised for the stationary noise and for the immediate coverage area for the short-term noise. The proposed algorithms were tested in a simulation for several floor plans of different complexity.

A measurement system for the long-term diagnostics of the thermal and technical properties of wooden houses

  • DOI: 10.21014/ACTA_IMEKO.V9I3.762
  • Odkaz: https://doi.org/10.21014/ACTA_IMEKO.V9I3.762
  • Pracoviště: Katedra měření
  • Anotace:
    To reduce the construction costs and to increase energy savings and the indoor environmental quality in a woodhouse, an energy consumption measuring system for diagnostics of thermal and technical properties of buildings envelope has been developed. At present, the vast majority of calculations for the thermal and technical characteristics of buildings are based on simple mathematical models of building envelope behavior derived primarily from the thermal transmittance of individual materials. However, the thermal transmittance is measured in a stable laboratory environment. Therefore, the measured values may not match the real behavior of materials in continually changing climatic conditions. The Energy Consumption Measuring System has been installed to seven woodhouses in different climatic areas to diagnose the thermal and technical properties of a building's envelope. The power consumption, temperature, and humidity of the air and of the wood, CO2 concentration, temperature of the individual layers of the envelope sandwich structure, and wind speed and direction are measured. Thanks to the sets of real measurements of the thermal and technical behavior, the actual dependence of the indoor environment quality on the outdoor climatic conditions can be obtained. The presented system can reveal imperfections in heat capacity and hygroscopicity of materials used for the construction of a woodhouse. Based on this measurement, the materials can be revised to save the construction costs, energy savings, and to increase the indoor environment quality, together with environmental impact reduction.

Automatic Control Points Computation for the Acoustic Noise Level Audits

  • Autoři: Ing. Tomáš Drábek, Ph.D., Petrík, V., prof. Ing. Jan Holub, Ph.D.,
  • Publikace: 17th IMEKO TC 10 and EUROLAB Virtual Conference: “Global Trends in Testing, Diagnostics & Inspection for 2030”. Warsaw: IMEKO TC10, 2020. p. 374-379. ISBN 978-92-990084-6-1.
  • Rok: 2020
  • Pracoviště: Katedra měření
  • Anotace:
    The acoustic noise level in the interior is one of the quantities specified by a standard and is subject to audits to ensure a comfortable living environment. Currently, the noise level audits are performed manually by a skilled operator, who estimates the floor plan and uses it to calculate the control points location in which the measurement is performed. We propose to automate the computation by formulating an optimization problem for which we designed an algorithm. Algorithm computes the solution that satisfies all constraints specified in the standard, for example, the minimum distance among the control points and fixed obstacles (walls or columns). In the proposed optimization problem, we designed the fitness function based on the measurement purpose, and we analysed two typical use-cases: (i) long-term stationary noise measurement and (ii) recurring short-term noise measurement. Although the set of control points for both use cases obeys the given standard, it is beneficial to distinguish the location of control points based on the measurement purpose. We maximize the number of control points for the stationary noise and maximize the immediate coverage area for the short-term noise. We tested the proposed algorithms in simulation for several floor plans of different complexity.

Low Bit-rate Coded Speech Intelligibility Testing in Czech Language using Parallel Task

  • Autoři: Avetisyan, H., prof. Ing. Jan Holub, Ph.D., Slavata, O.
  • Publikace: Journal of Audio Engineering Society. 2020, 2020(3), 284-291. ISSN 1549-4950.
  • Rok: 2020
  • DOI: 10.17743/jaes.2020.0008
  • Odkaz: https://doi.org/10.17743/jaes.2020.0008
  • Pracoviště: Katedra měření
  • Anotace:
    This article deals with subjective tests of speech intelligibility. A set of samples in Czechlanguage, recorded by four different narrators, was distorted with different noise levels andencoded by a low bit-rate encoder. The subjective test consisted of two parts. The first part(45 participants) proceeded according to the ITU-T Recommendation P.807 - Subjective testmethodology for assessing speech intelligibility. The second part (70 participants) included anadditional (parallel) psychomotor task deploying a laser-shooting simulator, where subjectshad the roles of “shooters” and “counters”. The purpose of the parallel task is to bring thetesting closer to the real use of technology. Significant differences have been found in theresults of the intelligibility of samples from different speakers. There were also differences inevaluation with and without a parallel task. Samples from male narrators have a significantlyhigher intelligibility score in the standard laboratory test, but also show a greater decrease inintelligibility after engaging a parallel task.

Statistical-Based Control Points Selection for Indoor Illuminance Measurement

  • DOI: 10.1109/TIM.2020.2987635
  • Odkaz: https://doi.org/10.1109/TIM.2020.2987635
  • Pracoviště: Katedra měření
  • Anotace:
    The distribution of indoor illuminance affects the health and the performance of humans, and is therefore subject to audits. Audits are performed after each modification of the light sources, and the currently adopted approach uses a human operator to perform measurements manually. This process is time-consuming, and we therefore aim to automate it with a mobile platform. In order to automate the process, we propose an online algorithm for selecting the control points. The algorithm is iterative, and it takes previous measurements into account in order to select the control points adaptively. We show how the proposed method can be combined with a mobile platform to perform the audit autonomously. Initially, the mobile platform, equipped with a laser range finder, is used to build the floor plan of the room. This floor plan is then used to restrict the area within which the control points can be selected. The whole measurement process is then executed without the presence or the intervention of a human operator, and this reduces the time needed for the audit. We have performed simulated and real experiments to demonstrate the performance of the proposed approach.

System for Acoustic Detection

  • Pracoviště: Katedra měření
  • Anotace:
    At present, acoustic detection techniques of gunshots (gunshot detection) are increasingly being used not only for military applications but also for civilian purposes. Detection, localization, and classification of gunshots employing acoustic detection is perspective alternative to visual detection, which is commonly used. In certain situations, to detect a source of a gunshot, an automatic acoustic detection system may be preferable. This paper presents a system for acoustic detection, which can detect localize and classify acoustic events such as gunshots. Tested firearms are 9 mm short gun, 6.35 mm short gun, .22 short gun, and .22 rifle gun with various subsonic and supersonic ammunition. As “false alarms,” sets of different impulse acoustic events like door slams, breaking glass, etc. have been used. To successfully classify the tested acoustic signals, Continuous Wavelet and Mel Frequency Transformation methods have been used for the signal processing, and the fully two-layer connected neural network has been implemented. The results show that the acoustic detector can be used for reliable gunshot detection, localization, and classification.

Akustická detekce a lokalizace zdroje střelby

  • Pracoviště: Katedra měření
  • Anotace:
    V současné době jsou techniky detekce akustických impulzních signálů (detekce výstřelů) čím dál více využívány nejen pro vojenské aplikace, ale také pro civilní účely. S přibývajícími útoky ve školách, kampusech, nákupních centrech nebo v nemocnicích vzniká požadavek automatického rozpoznání střelby i jinými metodami než kamerovými systémy ve spojení s operátorem. Lokalizace a klasifikace střelby pomocí akustické detekce je proto z hlediska bezpečnosti obyvatelstva čím dál tím důležitější.

Characterization of the Solar Cells Under the Real Conditions

  • Pracoviště: Katedra měření
  • Anotace:
    With an increasing number of wearable devices of all shapes and forms, which are equipped with new types of sensors to count steps, measure heart rate or even detect a fall, there is a requirement for more energy. Energy harvesting is one of the possible ways to increase the energy capability of such devices. The solar cells offer a renewable green source of energy to increase the power of wearable devices. At present, there is no binding uniform methodology for Solar Cell characterization under real light conditions of everyday life. The article presents a daily generation of energy in various daily life activity such as walking, car driving or office working with indoor illuminating. The solar cell, working in Maximum Power Point Tracking, attached to the hand of the person has been used. The presented results show expected amounts of generated energy in everyday life activities, which could be used for a better characterization of solar cells in the future.

F0-Lab - the simple tool for laboratory experiments in measurement and instrumentation

  • DOI: 10.1117/12.2530621
  • Odkaz: https://doi.org/10.1117/12.2530621
  • Pracoviště: Katedra měření
  • Anotace:
    Platform F0-Lab including LEO (Little Embedded Oscilloscope) was designed and developed to substitute a professional set of instruments in experiments concerning electronics, measurement, and instrumentation. It is based on a microcontroller, which includes the sufficiently fast ADC. It enables to realize (in connection with PC) a simple DC voltmeter, a digitizing oscilloscope, a waveform recorder, and a PWM signal generator. The microcontroller can be placed in a solderless breadboard where the student realizes experimental circuits. The PC controls this virtual instrument, displaying results and supplying the power of the entire set using USB. F0-Lab is successfully used for three years and more than 300 various implementations have been already realized.

Laboratory exercise of digital measurement system based on Modbus protocol used for indoor environment monitoring

  • DOI: 10.1117/12.2527892
  • Odkaz: https://doi.org/10.1117/12.2527892
  • Pracoviště: Katedra měření
  • Anotace:
    The proposed laboratory exercise is focused on the measurement of indoor environment quality (temperature, humidity, CO2 concentration) using digital measurement system based on Modbus protocol. Students acquire practical knowledge and general principles of the Modbus protocol, configuration and communication principles of smart sensors and measurement of temperature, humidity, CO2 concentration together with power consumption. The benefit for students in comparison with the old task is the improved quality of the laboratory task in the area of measurement circuits and fieldbus communication with the focus on industrial application.

Parallel task contexts in QoE testing. Can EEG help to understand the results?

  • Autoři: prof. Ing. Jan Holub, Ph.D., Pánek, D.
  • Publikace: Proceedings of the 23rd International Congress on Acoustics, integrating 4th EAA Euroregio 2019. Dresden: Deutsche Gesellschaft für Akustik, 2019. p. 6150-6157. ISSN 2226-7808. ISBN 978-3-939296-15-7.
  • Rok: 2019
  • DOI: 10.18154/RWTH-CONV-238824
  • Odkaz: https://doi.org/10.18154/RWTH-CONV-238824
  • Pracoviště: Katedra měření
  • Anotace:
    Improved intelligibility of distorted speech has been observed after a parallel psycho-motor task has been introduced. Electroencephalographic activity has been recorded and analyzed for several test situations – neutral, a plain intelligibility test, an intelligibility test with parallel aimed shooting, and an intelligibility test with parallel hit counting. Our findings indicate increased brain activity in the area of the central auditory circles, which evaluate the content of audio information during a parallel cognitive and motor task when the complex motor parallel task is considered to be primary (more important).

Smart Acoustic Sensor

  • DOI: 10.1109/RTSI.2019.8895591
  • Odkaz: https://doi.org/10.1109/RTSI.2019.8895591
  • Pracoviště: Katedra měření
  • Anotace:
    To automatically detect dangerous situations in public areas, systems based on visual detection are the most commonly used. In certain situations, to detect a source of danger, an automatic acoustic detection system may be preferable. This paper presents a smart acoustic sensor system, which automatically detects acoustic pulse events, such as gunshots, in public places, and localizes the position of the acoustic source. Tested firearms are 9 mm short gun, 6.35 mm short gun, .22 short gun with various subsonic and supersonic ammunition. Various sounds like door slams, human screams, etc. represent false alarms.

Solar Panel and Harvesting Systems - Use Cases, Measurements and Reporting Methodologies

  • Pracoviště: Katedra měření
  • Anotace:
    With an increasing number of wearable devices of all shapes and forms, which are equipped with new types of sensors to count steps, measure heart rate or even detect a fall, there is a requirement for more energy. Energy harvesting is one of the possible ways to increase the energy capability of such devices. The solar cells offer a renewable green source of energy to increase the power of wearable devices. At present, there is no binding uniform methodology for Solar Cell characterization under real light conditions of everyday life. The article presents a daily generation of energy in various daily life activity such as walking, car driving or office working with indoor illuminating. The solar cell, working in Maximum Power Point Tracking, attached to the hand of the person has been used. The presented results show expected amounts of generated energy in everyday life activities, which could be used for a better characterization of solar cells in the future.

The new subject at the Czech Technical University in Prague: laboratories of industrial electronics and sensors

  • DOI: 10.1117/12.2530690
  • Odkaz: https://doi.org/10.1117/12.2530690
  • Pracoviště: Katedra měření
  • Anotace:
    The subject of the Industrial Electronics and Sensors Laboratory has been designed to be focused on the practical part of the teaching. Here we describe its concept, used equipment and task examples. Experience gathered during subject first run is reported, including final students’ feedback.

Woodhouse Energy Consumption Measurement System for Diagnostics of Thermal and Technical Properties of Buildings Envelope

  • Autoři: Ing. Jakub Svatoš, Ph.D., prof. Ing. Jan Holub, Ph.D.,
  • Publikace: 23rd IMEKO TC4 Symposium Electrical & Electronic Measurement. Budapest: IMEKO TC4 Technical Committee on Measurement of Electrical Quantities, 2019. p. 1-5. 23. ISBN 978-606-13-5238-8.
  • Rok: 2019
  • Pracoviště: Katedra měření
  • Anotace:
    To reduce the construction costs and to increase energy savings and the indoor environmental quality in a woodhouse, an energy consumption measuring system for diagnostics of thermal and technical properties of buildings envelope is introduced. At present, the vast majority of calculations for the thermal and technical characteristics of buildings are based on simple mathematical models of building envelope behaviour derived primarily from the thermal conductivity of individual materials. However, the thermal conductivity is measured in a stable laboratory environment. Therefore, the measured values may not match the real behaviour of materials in continually changing climatic conditions. The Energy Consumption Measuring System has been installed to eight woodhouses in different climatic areas to diagnose the thermal and technical properties of buildings envelope. The power consumption, temperature, and humidity of the air and of the wood, CO2 concentration, temperature of the individual layers of the envelope sandwich structure and wind speed and direction are measured. Thanks to the sets of real measurements of the thermal and technical behaviour, the actual dependence of the indoor environment quality on the outdoor climatic conditions are obtained.

Akustická detekce střelby (nejen) v ulicích města

  • Pracoviště: Katedra měření
  • Anotace:
    V současnosti jsou techniky detekce akustických impulzních signálů, neboli detekce střelby, používány nejen ve vojenských aplikacích, ale také v civilních oblastech, jako jsou detekce střelby ve školách, kampusech, nákupních centrech nebo v nemocnicích. Detekce, lokalizace a klasifikace střelby je z hlediska bezpečnosti obyvatelstva čím dál tím důležitější.

Analysis of the Dependency of Call Duration on the Quality of VoIP Calls

  • Autoři: prof. Ing. Jan Holub, Ph.D., Wallbaum, M., Smith, N., Avetisyan, H.
  • Publikace: IEEE Wireless Communications Letters. 2018, 7(4), 638-641. ISSN 2162-2337.
  • Rok: 2018
  • DOI: 10.1109/LWC.2018.2806442
  • Odkaz: https://doi.org/10.1109/LWC.2018.2806442
  • Pracoviště: Katedra měření
  • Anotace:
    This paper analyses call detail records of 16 million live calls over Internet-Protocol-based telecommunications networks. The objective is to examine the dependency between average call duration and call quality as perceived by the user. Surprisingly, the analysis suggests that the connection between quality and duration is non-monotonic.

Assessment of ECG and respiration recordings from simulated emergency landings of ultra light aircraft

  • DOI: 10.1038/s41598-018-25528-z
  • Odkaz: https://doi.org/10.1038/s41598-018-25528-z
  • Pracoviště: Katedra měření
  • Anotace:
    Pilots of ultra light aircraft have limited training resources, but with the use of low cost simulators it might be possible to train and test some parts of their training on the ground. The purpose of this paper is to examine possibility of stress inducement on a low cost flight simulator. Stress is assessed from electrocardiogram and respiration. Engine failure during flight served as a stress inducement stimuli. For one flight, pilots had access to an emergency navigation system. There were recorded some statistically significant changes in parameters regarding breathing frequency. Although no significant change was observed in ECG parameters, there appears to be an effect on respiration parameters. Physiological signals processed with analysis of variance suggest, that the moment of engine failure and approach for landing affected average breathing frequency. Presence of navigation interface does not appear to have a significant effect on pilots.

Elektrická měření - Přístroje a metody

  • Pracoviště: Katedra měření
  • Anotace:
    Stejně jako původní vydání knihy Elektrická měření – přístroje a metody z roku 2003 i toto shrnuje informace týkající se oblasti elektrických a magnetických měření na úrovni absolventa inženýrského studia elektrotechnických oborů. Vzhledem k prudkému rozvoji elektroniky a číslicové techniky však byla náplň většiny kapitol značně modernizována popř. rozšířena a část věnovaná analogovým přístrojům naopak významně zredukována. V publikaci jsou vysvětleny základní principy používané v současné době pro měření elektrických popř. magnetických veličin a principy nejčastěji používaných metod pro měření ostatních fyzikálních veličin s mezipřevodem na elektrický signál. Jsou popsány též běžně používané měřicí přístroje a principy jejich činnosti, s čímž samozřejmě souvisí i jejich vlastnosti. Vzhledem k tomu, že jejich základním blokem jsou analogově-číslicové popř. číslicově-analogové převodníky, je samostatná kapitola věnována i digitalizaci signálu. Problematika určování nejistot měření je klíčovým parametrem při řízení a kontrole kvality výroby. Nejistotám měření je proto věnována nejen celá 1. kapitola, ale odhad nejistot je také zmíněn i v kapitolách věnovaným metodám měření aktivních elektrických veličina parametrů pasivních součástek.

Low Bit-rate Coded Speech Intelligibility Tested with Parallel Task

  • DOI: 10.3813/AAA.919207
  • Odkaz: https://doi.org/10.3813/AAA.919207
  • Pracoviště: Katedra měření
  • Anotace:
    A speech intelligibility test in realistic environments has been designed and performed deploying 51 subjects. A single set of speech samples distorted by various background noises and low bit-rate coding techniques has been used - without and with additional (parallel) psychomotor tasks. The addition of psychomotor tasks to the test simulates realistic environments. The differences in intelligibility test results between standard laboratory and parallel task test methodology were identified. Overall, the intelligibility of regular tests was mainly higher than for tests with a parallel task. Intelligibility results of certain samples have been found counterintuitive, which is possibly explained by a different mode of thinking under parallel task conditions.

Subjective audio quality testing, with tasting and car driving as parallel task

  • Autoři: prof. Ing. Jan Holub, Ph.D., Sula, J., Soares, L., Slavata, O.
  • Publikace: IEEE Access. 2018, 2018(2018), 60769-60775. ISSN 2169-3536.
  • Rok: 2018
  • DOI: 10.1109/ACCESS.2018.2873568
  • Odkaz: https://doi.org/10.1109/ACCESS.2018.2873568
  • Pracoviště: Katedra měření
  • Anotace:
    The article reports subjective test results of two different test sets, always without and with parallel task. Based on the subjective test results, an objective estimator of speech quality assessed with a parallel task based on enhanced ITU-T P.863 (POLQA) algorithm has been derived. It provides more accurate estimate of the subjective test results with a parallel task the the original POLQA algorithm.

Subjective Speech Quality Measurement with and without Parallel Task: Laboratory Test Results Comparison

  • DOI: 10.1371/journal.pone.0199787
  • Odkaz: https://doi.org/10.1371/journal.pone.0199787
  • Pracoviště: Katedra měření
  • Anotace:
    This paper focuses on a novel methodology of subjective speech quality measurement and repeatability of its results between laboratory conditions and simulated environmental conditions. A single set of speech samples was distorted by various background noises and low bit-rate coding techniques. This study aimed to compare results of subjective speech quality tests with and without a parallel task deploying the ITU-T P.835 methodology. Afterward, tests results performed with and without a parallel task were compared using Pearson correlation, CI95, and numbers of opposite pair-wise comparisons. The tests show differences in results in the case of a parallel task.

Subjective Testing of Car Audio Systems With and Without Parallel Task

  • Pracoviště: Katedra měření
  • Anotace:
    This contribution presents a comparison between listening tests that were conducted in two different simulated listening situations: listening only in a stationary, parked car and listening while driving a (simulated) car. In both tests, identical signals and identical playback configurations were used leaving the situation as only variable in the test.

Stress Measurement and Inducement in Experiments with Low Cost Flight Simulator for Testing of General Aviation Pilots

  • Autoři: Bruna, O., Levora, T., prof. Ing. Jan Holub, Ph.D.,
  • Publikace: HCI International 2017 – Posters' Extended Abstracts. Cham: Springer International Publishing AG, 2017. p. 218-223. Communications in Computer and Information Science. vol. 713. ISSN 1865-0929. ISBN 978-3-319-58749-3.
  • Rok: 2017
  • DOI: 10.1007/978-3-319-58750-9_31
  • Odkaz: https://doi.org/10.1007/978-3-319-58750-9_31
  • Pracoviště: Katedra měření
  • Anotace:
    Full flight simulators are mainly a domain of airliner pilots. Such simulators with moving platform are high fidelity devices, which can reliably replicate real flight experience. Unfortunately the cost of a flight hour and maintenance is rather high and therefore not suitable for training of pilots of ultra-light aircraft. Yet there are accidents which might have been prevented with extended flight hours and additional training, like emergency landings, dealing with spiral spin, engine outage. Low cost simulators can be a viable solution for additional training and practice. This poster is based on data taken from stress inducing experiment. Poster presents analysis of physiological measurements taken from pilots interacting with a low cost 6DOF flight simulator of ultra-light aircraft with the goal to assess presence of stress and identify its generating factors. Proper identification and classification of these factors may help to generate such state during training and testing. The goal is to evaluate physiologically measurable response. The experiment attempts to generate stress with engine outage observing ECG and respiration signals.

Subjective speech quality measurement repeatability: comparison of laboratory test results

  • Autoři: prof. Ing. Jan Holub, Ph.D., Avetisyan, H., Isabelle, S.
  • Publikace: International Journal of Speech Technology. 2017, 20(1), 69-74. ISSN 1381-2416.
  • Rok: 2017
  • DOI: 10.1007/s10772-016-9389-6
  • Odkaz: https://doi.org/10.1007/s10772-016-9389-6
  • Pracoviště: Katedra měření
  • Anotace:
    This article reports on a multi-lab subjective listening experiment aiming at inter-lab and intra-lab test results repeatability verification. An identical set of speech samples corresponding to contemporary networks has been tested by three independent labs deploying ITU-T P.835 methodology. The tests results have been compared regarding Pearson correlation, RMSE, RMSE* and numbers of opposite pair-wise comparisons. The results show the level of inter-lab and intra-lab repeatability in the case of identical test speech samples utilization and thus confirm the subjective tests are highly repeatable in case they follow recommendation requirements strictly. The tests also show differences in results in case subject expectations are set differently using a wider set of test speech samples (as presented in one of the labs).

Emotion models for textual emotion classification

  • Autoři: Bruna, O., Avetisyan, H., prof. Ing. Jan Holub, Ph.D.,
  • Publikace: Journal of Physics: Conference Series. Bristol: Institute of Physics Publishing, 2016. Journal of Physics: Conference Series. ISSN 1742-6596.
  • Rok: 2016
  • DOI: 10.1088/1742-6596/772/1/012063
  • Odkaz: https://doi.org/10.1088/1742-6596/772/1/012063
  • Pracoviště: Katedra měření
  • Anotace:
    This paper deals with textual emotion classification which gained attention in recent years. Emotion classification is used in user experience, product evaluation, national security, and tutoring applications. It attempts to detect the emotional content in the input text and based on different approaches establish what kind of emotional content is present, if any. Textual emotion classification is the most difficult to handle, since it relies mainly on linguistic resources and it introduces many challenges to assignment of text to emotion represented by a proper model. A crucial part of each emotion detector is emotion model. Focus of this paper is to introduce emotion models used for classification. Categorical and dimensional models of emotion are explained and some more advanced approaches are mentioned.

Overview of existing algorithms for emotion classification. Uncertainties in evaluations of accuracies.

  • Autoři: Avetisyan, H., Bruna, O., prof. Ing. Jan Holub, Ph.D.,
  • Publikace: Journal of Physics: Conference Series. Bristol: Institute of Physics Publishing, 2016. Journal of Physics: Conference Series. ISSN 1742-6596.
  • Rok: 2016
  • DOI: 10.1088/1742-6596/772/1/012039
  • Odkaz: https://doi.org/10.1088/1742-6596/772/1/012039
  • Pracoviště: Katedra měření
  • Anotace:
    A numerous techniques and algorithms are dedicated to extract emotions from input data. In our investigation it was stated that emotion-detection approaches can be classified into 3 following types: Keyword based / lexical-based, learning based, and hybrid. The most commonly used techniques, such as keyword-spotting method, Support Vector Machines, Naïve Bayes Classifier, Hidden Markov Model and hybrid algorithms, have impressive results in this sphere and can reach more than 90% determining accuracy.

Impact of the Codec and Various QoS Methods on the Final Quality of the Transferred Voice in an IP Network

  • Autoři: Slavata, O., prof. Ing. Jan Holub, Ph.D.,
  • Publikace: 2014 joint IMEKOTC1-TC7-TC13 Symposium: Measurement Science Behind Safety and Security. Madeira: IOPscience, 2015, ISSN 1742-6588. Available from: http://iopscience.iop.org/1742-6596/588/1/012011/
  • Rok: 2015
  • DOI: 10.1088/1742-6596/588/1/012011
  • Odkaz: https://doi.org/10.1088/1742-6596/588/1/012011
  • Pracoviště: Katedra měření
  • Anotace:
    This paper deals with an analysis of the relation between the codec that is used, the QoS method, and the final voice transmission quality. The Cisco 2811 router is used for adjusting QoS. VoIP client Linphone is used for adjusting the codec. The criterion for transmission quality is the MOS parameter investigated with the ITU-T P.862 PESQ and P.863 POLQA algorithms.

New Approach in Subjective and Objective Speech Transmission Quality Measurement in TCP/IP Networks

  • Autoři: Souček, P., Slavata, O., prof. Ing. Jan Holub, Ph.D.,
  • Publikace: 2014 joint IMEKOTC1-TC7-TC13 Symposium: Measurement Science Behind Safety and Security. Madeira: IOPscience, 2015. p. 1-4. ISSN 1742-6588.
  • Rok: 2015
  • DOI: 10.1088/1742-6596/588/1/012020
  • Odkaz: https://doi.org/10.1088/1742-6596/588/1/012020
  • Pracoviště: Katedra měření
  • Anotace:
    This paper deals with problems of speech transmission quality measurement in modern telecommunication networks. It focuses on problems caused by specific types of distortions and errors caused present in transmissions using TCP/IP networks and proposes a new method for their consideration.

Přenosný systém pro měření akustické odrazivosti povrchu

  • Autoři: Bruna, O., prof. Ing. Jan Holub, Ph.D.,
  • Publikace: Sympozium Energeticky efektivní budovy 2015. Praha: Společnost pro techniku prostředí, 2015, pp. 33-38. 1. vydání. ISBN 978-80-02-02615-0.
  • Rok: 2015
  • Anotace:
    Akustická odrazivost materiálu je vlastnost, vyplývající ze složení měřeného povrchu. Podle této vlastnosti lze tedy teoreticky posoudit, o jaký materiál se jedná a předejít fyzickému odebrání vzorku. Příspěvek popisuje princip měření akustické odrazivosti povrchu prostřednictvím nové metody. Výhodou této metody je její flexibilita a potencionální možnost použití přímo v terénu. Text vysvětluje principy použité metody, testovací měření a prezentuje výstupy těchto měření.

The Innovation of the Autonomous System for Indoor Illuminance

  • Autoři: Ing. Tomáš Drábek, Ph.D., prof. Ing. Jan Holub, Ph.D.,
  • Publikace: Proceedings of the 21st International Conference LIGHT SVĚTLO 2015. Brno: Brno University of Technology, FEEC, Department of Electrical Power Engineering, 2015, pp. 273-276. ISBN 978-80-214-5244-2.
  • Rok: 2015
  • Pracoviště: Katedra měření
  • Anotace:
    The goal of this report is to show the results we achieved in the field of autonomous indoor illuminance measurement. At the beginning of the paper the state of the art measurement methodology is shown. It is followed by the description of the robotic unit we designed for the purpose of automation of the measurement process. Moreover, the algorithm for measurement process is described in detail. The rest of the paper deals with possible improvements of the robotic platform mainly by adding new sensors and by adding the illuminance vector measurement unit.

Using long samples in subjective testing of voice transmission quality in IP network

  • Autoři: Slavata, O., Souček, P., prof. Ing. Jan Holub, Ph.D.,
  • Publikace: 2015 Wireless Telecommunications Symposium (WTS). New York: IEEE, 2015. ISSN 1934-5070. ISBN 978-1-4799-6776-6.
  • Rok: 2015
  • DOI: 10.1109/WTS.2015.7117260
  • Odkaz: https://doi.org/10.1109/WTS.2015.7117260
  • Pracoviště: Katedra měření
  • Anotace:
    This paper deals with problems of speech transmission quality measurement in TCP/IP networks. It focuses on problems caused by the inaccuracy of current methods for measuring the quality degradation caused by packet loss and jitter. The proposed solution is to use longer samples for listening tests. This article compares three evaluation methods for listening tests.

Determination of Material Acoustic Features Using Small Samples

  • Autoři: prof. Ing. Jan Holub, Ph.D., Desbos, B., Vacek, V., Kolísko, J.
  • Publikace: Local Mechanical Properties X. Zurich: TRANS TECH PUBLICATIONS LTD, 2014. pp. 111-114. ISSN 1013-9826. ISBN 978-3-03835-062-0.
  • Rok: 2014
  • DOI: 10.4028/www.scientific.net/KEM.606.111
  • Odkaz: https://doi.org/10.4028/www.scientific.net/KEM.606.111
  • Pracoviště: Katedra měření
  • Anotace:
    One method to determine acoustic absorption in-situ is described in this paper. For practical consideration, this measurement can be performed on small samples (square of 60x60cm). This paper describes all the steps needed to obtain results: device setup, recording, signal processing.

Options of Assessment of Absorption Capacity of Noise Barrier

  • Autoři: Vacek, V., prof. Ing. Jan Holub, Ph.D.,
  • Publikace: Advanced Materials Research. Uetikon-Zurich: Trans Tech Publications Inc., 2014. pp. 125-129. Proceedings of the Conference on the Rehabilitation and Reconstruction of Buildings CRRB 2013. ISSN 1022-6680. ISBN 978-3-03835-083-5.
  • Rok: 2014
  • DOI: 10.4028/www.scientific.net/AMR.923.125
  • Odkaz: https://doi.org/10.4028/www.scientific.net/AMR.923.125
  • Pracoviště: Katedra měření
  • Anotace:
    The contribution deals with the possibilities of measuring the sound absorption coefficient of concrete panels. On the example of the modified concrete shows one of the possible methods that could be used to check for changes in the case of acoustic properties of restoration of the damaged panels. The issue of evaluation of the sound absorption coefficient is quite complex and difficult in the interpretation of the results, primarily due to the impact of the size of the tested element and parasitic interference in the surrounding environment.

Přenosné zařízení pro měření akustické odrazivosti a pohltivosti povrchů

  • Autoři: prof. Ing. Jan Holub, Ph.D., Slavata, O., Bruna, O., Vacek, V.
  • Publikace: Sdělovací technika. 2014, 61(9), 43-45. ISSN 0036-9942.
  • Rok: 2014
  • Pracoviště: Katedra měření
  • Anotace:
    Článek popisuje jednu z metod měření akustické odrazivosti a pohltivosti povrchů a její zjednodušenou implementaci ve formě aplikace pro mobilní telefon. Praktické měření bylo demonstrováno na betonových deskách s různým množstvím pryžového recyklátu, a to pomocí mobilního telefonu s operačním systémem Android a připojeným externím reproduktorem.

Towards Layer Adaptation for Audio Transmission

  • Autoři: prof. Ing. Jan Holub, Ph.D., Slavata, O., Souček, P., Zisimopoulos, O., Toumpakaris, D., Kotsopoulos, S.
  • Publikace: International Journal of Interdisciplinary Telecommunications and Networking. 2014, 6(4), 35-41. ISSN 1941-8663.
  • Rok: 2014
  • DOI: 10.4018/IJITN.2014100104
  • Odkaz: https://doi.org/10.4018/IJITN.2014100104
  • Pracoviště: Katedra měření
  • Anotace:
    The purpose of this paper is to investigate if rate adaptation can be avoided, and a system can rely instead on the audio encoder and decoder to alleviate the effect of channel errors.

Towards Layer Adaptation for Audio Transmission

  • Autoři: prof. Ing. Jan Holub, Ph.D., Slavata, O., Souček, P., Zisimopoulos, O., Toumpakaris, D., Kotsoupoulos, S.
  • Publikace: 2014 Wireless Telecommunications Symposium (WTS). Piscataway: IEEE, 2014, pp. 1-4. ISBN 978-1-4799-1297-1.
  • Rok: 2014
  • Pracoviště: Katedra měření
  • Anotace:
    This contribution reports on a set of experiments on various combinations of channel conditions, constellation sizes and audio encoding used and on the final audio quality achieved. The Mean Opinion Score (MOS) is used for performance evaluation. The MOS values are generated using the ITU-T P.862 (PESQ) and P.863 (POLQA) algorithms, and are corroborated using tests by experts. The result support the common practice of adapting the physical layer parameters to changing channel conditions. However, in sime cases, it is possible to maintain a constant rate without impacting significantly the quality of the audio. This means that the complexity associated with physical layer and audio rate adaptation can be avoided keading to simpler and more robust designs.

Effect of speech activity parameter on PESQ's predictions in presence of independent and dependent loses

  • Autoři: Počta, P., prof. Ing. Jan Holub, Ph.D.,
  • Publikace: Computer Standards & Interfaces. 2013, 1(36), 143-153. ISSN 0920-5489.
  • Rok: 2013
  • DOI: 10.1016/j.csi.2013.07.001
  • Odkaz: https://doi.org/10.1016/j.csi.2013.07.001
  • Pracoviště: Katedra měření
  • Anotace:
    The paper deals with the investigation of PESQ's (Perceptual Evaluation of Speech Quality; also known as ITU-T Recommendation P.862) behavior under independent and dependent loss conditions from a speech activity parameter perspective. The results show that an increase in amount of speech in the reference signal (expressed by the activity parameter) may result in an increase of the PESQ sensitivity to packet loss change as well as PESQ's prediction accuracy improvement. On the other hand, it seems that human brain is a bit less sensitive to loss of some parts of words than PESQ. The reasons for those findings are particularly discussed.

Evaluation of Objective Speech Transmission Quality Measurements in Packet-based Networks

  • Autoři: Slavata, O., prof. Ing. Jan Holub, Ph.D.,
  • Publikace: Computer Standards & Interfaces. 2013, 36(3), 626-630. ISSN 0920-5489.
  • Rok: 2013
  • DOI: 10.1016/j.csi.2013.09.003
  • Odkaz: https://doi.org/10.1016/j.csi.2013.09.003
  • Pracoviště: Katedra měření
  • Anotace:
    Paper presents an analysis of the relation between IP channel characteristics and final voice transmission quality. The NISTNet emulator is used for adjusting the IP channel network. The transmission quality criterion is an MOS parameter investigated using the ITU-T P.862 PESQ, future P.863 POLQA and P.563 3SQM algorithms. Jitter and packet loss influence are investigated for the PCM codec and the Speex codec.

Experimental Stress Assessment in Biomedical Measurement Class

  • Autoři: Bruna, O., prof. Ing. Jan Holub, Ph.D., doc. Ing. Pavel Pačes, Ph.D.,
  • Publikace: IDAACS 2013 - Proceedings of the 2013 IEEE 7th International Conference on Intelligent Data Acquisition and Advanced Computing Systems. Berlin: IEEE, 2013, pp. 99-102. pozn.: CD má na nálepce jiné ISBN: 978-1-4799-1427-2. ISBN 978-1-4799-1426-5.
  • Rok: 2013
  • DOI: 10.1109/IDAACS.2013.6662648
  • Odkaz: https://doi.org/10.1109/IDAACS.2013.6662648
  • Pracoviště: Katedra měření
  • Anotace:
    Classes at Czech Technical University in Prague focused on biomedical engineering are mainly working with physiological aspects of human body. Nowadays it becomes more common to include also psychological effects on human body, because a mental state of a person can affect the way he or she behaves and approaches problems. This paper describes a class which shows how human body can be affected by its state [1],[3],[4]. The aim is make students realize, that people’s mental state can influence state of body’s function. It is important, because the psychological state can affect decision making skills and erformance. In today’s society is very important to consider a human as a part of the loop.

Incorporating Human Stress Measurements into Biomedical Engineering Class

  • Autoři: Bruna, O., Souček, P., prof. Ing. Jan Holub, Ph.D.,
  • Publikace: 2013 Joint IMEKO (International Measurement Confederation) TC1-TC7-TC13 Symposium: Measurement Across Physical and Behavioural Sciences. Bristol: IOP Publishing Ltd, 2013, pp. 1-6. Journal of Physics Conference Series. ISSN 1742-6588.
  • Rok: 2013
  • DOI: 10.1088/1742-6596/459/1/012011
  • Odkaz: https://doi.org/10.1088/1742-6596/459/1/012011
  • Pracoviště: Katedra měření
  • Anotace:
    The topic of this paper is to describe the current course at Czech Technical University in Prague X38KLS (Construction of medical systems) and to describe proposed improvements and differences between novel and old approach. The changes and in a state of preparation and have not been fully implemented. The new course should take over the old in September 2013.

Innovation of Laboratory Exercises in Course "Distributed Systems and Computer Networks"

  • Autoři: Souček, P., Slavata, O., prof. Ing. Jan Holub, Ph.D.,
  • Publikace: 2013 Joint IMEKO (International Measurement Confederation) TC1-TC7-TC13 Symposium: Measurement Across Physical and Behavioural Sciences. Bristol: IOP Publishing Ltd, 2013, pp. 1-4. Journal of Physics Conference Series. ISSN 1742-6588. Available from: http://iopscience.iop.org/1742-6596/459/1
  • Rok: 2013
  • DOI: 10.1088/1742-6596/459/1/012012
  • Odkaz: https://doi.org/10.1088/1742-6596/459/1/012012
  • Pracoviště: Katedra měření
  • Anotace:
    This paper is focused on innovation of laboratory exercises in course Distributed Systems and Computer Networks. These exercises were introduced in November of 2012 and replaced older exercises in order to reflect real life applications.

Management Conversational Quality Predictor

  • Autoři: prof. Ing. Jan Holub, Ph.D., Počta, J., Monfort, J.-F., Pomy, J.
  • Publikace: PQS 2013. Vienna: Telecommunications Research Center Vienna FTW, 2013. pp. 147-150.
  • Rok: 2013
  • Pracoviště: Katedra měření
  • Anotace:
    In a majority of modern networks traditional end-to-end transmission planning is no longer possible, but popular field testing in technologies such as UMTS, NGN and LTE, typically reveals only one quality component of the QoS. This paper describes an operational quality estimator developed within ETSI STF 436 project called Management Conversational Quality Predictor (MCQP) which can combine results from field trials with other impairments such as one-way delay, echo loss, type of conversation, etc. Potential areas for an extension of the designed model are outlined in a conclusion of the paper.

MOŽNOSTI HODNOCENÍ POHLTIVOSTI PROTIHLUKOVÝCH PANELŮ

  • Autoři: Vacek, V., prof. Ing. Jan Holub, Ph.D.,
  • Publikace: Zkoušení a jakost ve stavebnictví 2013. Brno: Vysoké učení technické v Brně, 2013. pp. 135-140. VUT Brno. ISBN 978-80-214-4777-6.
  • Rok: 2013
  • Pracoviště: Katedra měření
  • Anotace:
    Příspěvek se zabývá jednou z možností měření zvukové pohltivosti panelů. Popsaný postup je realizován na malých deskách, ve snaze získat na menších vzorcích výsledky srovnatelné s hodnocením velkých panelů, využitelné při jejich vývoji.

New Concept of Laboratory Exercise on Temperature Measurements Using Thermocouple

  • Autoři: Slavata, O., Souček, P., prof. Ing. Jan Holub, Ph.D.,
  • Publikace: 2013 Joint IMEKO (International Measurement Confederation) TC1-TC7-TC13 Symposium: Measurement Across Physical and Behavioural Sciences. Bristol: IOP Publishing Ltd, 2013, pp. 1-6. Journal of Physics Conference Series. ISSN 1742-6588. Available from: http://iopscience.iop.org/1742-6596/459/1/012059/pdf/1742-6596_459_1_012059.pdf
  • Rok: 2013
  • DOI: 10.1088/1742-6596/459/1/012059
  • Odkaz: https://doi.org/10.1088/1742-6596/459/1/012059
  • Pracoviště: Katedra měření
  • Anotace:
    The proposed exercise is focused on the measurement of temperature using thermocouple, students acquire theoretical knowledge of the Seebeck effect, the design and application of thermocouples including the differences between their various types. The students measure the voltage at the thermocouple by various methods: directly with a compensation box, using operational amplifiers and USB module. The exercise explains also general principles of low voltage measurements, error compensation and uncertainty evaluation.

Shift in Speech Quality and Acceptability Level between 2008-2012

  • Autoři: prof. Ing. Jan Holub, Ph.D., Souček, P.
  • Publikace: Wireless Telecommunications Symposium 2013 - Papers and Presentations. Piscataway: IEEE, 2013.
  • Rok: 2013
  • Pracoviště: Katedra měření
  • Anotace:
    This paper presents results of quality and acceptability level tests, performed on similar groups of listeners with two years span in years 2008, 2010 and 2012. It shows shift in both quality and acceptability level and compares them. The tests were conducted according to P.800.

Shift in Speech Quality and Acceptability Level between 2008-2012

  • Autoři: prof. Ing. Jan Holub, Ph.D., Souček, P.
  • Publikace: International Journal of Interdisciplinary Telecommunications and Networking. 2013, 5(3), 63-68. ISSN 1941-8663.
  • Rok: 2013
  • DOI: 10.4018/jitn.2013070107
  • Odkaz: https://doi.org/10.4018/jitn.2013070107
  • Pracoviště: Katedra měření
  • Anotace:
    This paper presents results of quality and acceptability level tests, performed on similar groups of listeners with two years span in years 2008, 2010 and 2012. It shows shift in both quality and acceptability level and compares them. The tests were conducted according to P.800.

Evaluation of a Flight-guidance System for Ultra-Light Aircraft

  • Autoři: Bruna, O., Levora, T., prof. Ing. Jan Holub, Ph.D.,
  • Publikace: HCI-Aero 2012 Proceedings - "Transition of Science into Reality". Brussels: Honeywell (USA), Eurocontrols (France), 2012. pp. 1-4.
  • Rok: 2012
  • Pracoviště: Katedra měření
  • Anotace:
    This early stage research paper describes the methodology for evaluation of a flight guidance system of an emergency landing decision support system for ultra-light aircraft. This system is intended to be used in small sport aircraft in order to help pilots cope with critical situations such as engine failure. Paper is focused on evaluation of first dry-run round, where four different metaphors were tested. As a result a hypothesis is formed and a direction of future research is proposed.

Evaluation of ITU-T P.863 POLQA in Chinese

  • Autoři: Souček, P., prof. Ing. Jan Holub, Ph.D.,
  • Publikace: IDAACS-SWS\'2012. Piscataway: IEEE, 2012. pp. 124-126. 1. ISBN 978-1-4673-4677-1.
  • Rok: 2012
  • Pracoviště: Katedra měření
  • Anotace:
    The main goal of this experiment is to evaluate performance of ITU-T P.863 POLQA in case of low-bitrate coders, namely MELPe, and Chinese language. Performance of POLQA is compared to its predecessor ITU-T P.862 PESQ.

Impact of IP Channel Parameters on the Final Quality of the Transferred Voice

  • Autoři: prof. Ing. Jan Holub, Ph.D., Slavata, O.
  • Publikace: Wireless Telecommunications Symposium 2012 Papers and Presentation. Pomona (CA): California State Polytechnic University, 2012. p. 1-5. ISBN 978-1-4577-0580-9.
  • Rok: 2012
  • Pracoviště: Katedra měření
  • Anotace:
    This paper deals with analysis of relation between IP channel characteristics and final voice transmission quality. For adjusting of IP channel network emulator NISTNet is used. Criterion of transmission quality is a MOS parameter investigated with an algorithms ITU-T P.862 PESQ, future P.863 POLQA and P.563 3SQM. The following characteristics have been explored: codec PCM, codec Speex, jitter and packet loss.

Impact of Jitter and Jitter Buffer on the Final Quality of the Transferred Voice

  • Autoři: Slavata, O., prof. Ing. Jan Holub, Ph.D., Hübner, P.
  • Publikace: IDAACS-SWS\'2012. Piscataway: IEEE, 2012. pp. 120-123. 1. ISBN 978-1-4673-4677-1.
  • Rok: 2012
  • Pracoviště: Katedra měření
  • Anotace:
    This paper deals with analysis of relation between packet delay variations (jitter), length of jitter buffer and final voice transmission quality. For adjusting of IP channel network emulator NISTNet is used. For adjusting of buffer length VoIP client Linphone is used. Criterion of transmission quality is a MOS parameter investigated with an algorithms ITU-T P.862 PESQ and P.863 POLQA.

Small Aircraft Emergency Landing Decision Support System - Pilots' Performance Assessment

  • Pracoviště: Katedra měření
  • Anotace:
    This paper describes the methodology for investigating the usability of an emergency landing decision support system for ultra-light aircraft pilots. The introduction covers the aim of the device, while section methodology describes what the goal was and how it was achieved. The evaluation discusses the interpretation of the data measured and interviewed outputs. This paper is concluded with our learning and suggests future work.

Subjective Testing and Objective Modelling of Influence of Different Social Classes to Voice Call Quality Perception

  • Pracoviště: Katedra měření
  • Anotace:
    Analysis of subjective testing and objective modelling of influence of different social classes to voice call quality perception is described in the article.

User-Centric Service Model in Wireless Networks: The Transition from Technical Excellence to Customer Experience Excellence in Wireless Networks

  • Autoři: prof. Ing. Jan Holub, Ph.D.,
  • Publikace: Wireless Telecommunications Symposium 2012 Papers and Presentation. Pomona (CA): California State Polytechnic University, 2012, pp. 1-37. ISBN 978-1-4577-0580-9. Available from: http://www.csupomona.edu/~wtsi/wts/Previous%20Conferences/WTS2012/program.htm
  • Rok: 2012
  • Pracoviště: Katedra měření
  • Anotace:
    Network operators realized the technical excellence is not enough and even worse might be unnecessarily expensive. User-centric approach enables to target different parts of customer portfolio with different service quality levels, keeping both capex and opex conveniently optimal but even discovering faults that are not easily visible just using purely technical approach.

How the Perceived Speech Quality and Acceptability Level Shift during Time

  • Autoři: Souček, P., prof. Ing. Jan Holub, Ph.D.,
  • Publikace: Measurement of Speech, Audio and Video Quality in Networks 2011. Praha: CTU Publishing House, 2011. pp. 31-33. ISBN 978-80-01-04848-1.
  • Rok: 2011
  • Pracoviště: Katedra měření
  • Anotace:
    The paper presents results of quality and acceptability level tests, performed on same group of listeners with two years span. It shows how it shifted in both quality and acceptability level. The tests were conducted according to P.800.

Objective Quality Measurements of Low Bit-Rate Coded Speech

  • Autoři: prof. Ing. Jan Holub, Ph.D.,
  • Publikace: MCC 2011 - Military Communications and Information Technology: A Comprehensive Approach Enabler. Warsaw: University of Warsaw, 2011. pp. 441-445. ISBN 978-83-62954-20-9.
  • Rok: 2011
  • Pracoviště: Katedra měření
  • Anotace:
    New results of speech transmission quality measurements obtained by a recently developed algorithm POLQA - ITU-T P.863 are presented. Our research shows acceptable accuracy for databases containing significant portion of low bit-rate coded samples, namely by MELPe 2.4 kbit/s. The POLQA results are compared with subjective test results based on ITU-T P.800.

Predicting the Quality of Synthesized and Natural Speech Impaired by Packet Loss and Coding Using PESQ and P.563 Models

  • Autoři: Počta, P., prof. Ing. Jan Holub, Ph.D.,
  • Publikace: ACTA ACUSTICA UNITED WITH ACUSTICA. 2011, 97(5), 852-868. ISSN 1610-1928.
  • Rok: 2011
  • DOI: 10.3813/AAA.918465
  • Odkaz: https://doi.org/10.3813/AAA.918465
  • Pracoviště: Katedra měření
  • Anotace:
    This paper investigates the impact of independent and dependent losses and coding on speech quality predictions provided by PESQ (also known as ITU-T P.862) and P.563 models, when both naturally-produced and synthesized speech are used.

Subjective Measurement and Objective Modeling of Voice Quality in a Conference Call for a Stressed Listener

  • Autoři: Slavata, O., prof. Ing. Jan Holub, Ph.D.,
  • Publikace: Measurement of Speech, Audio and Video Quality in Networks 2011. Praha: CTU Publishing House, 2011, pp. 14-19. ISBN 978-80-01-04848-1.
  • Rok: 2011
  • Pracoviště: Katedra měření
  • Anotace:
    This paper verifies the effect of delay of voice information between the participants in a conference telephone call on the subjective assessment of the quality of the conversation. And evaluate changes in the assessment of individual respondents based on their mental state. Criterion of transmission quality is a parametr MOS obtained from respondents of subjective tests before and after the stressful situation.

Validation of ITU-T P.863 for Low Bit-rate Coded Speech Quality Measurements

  • Autoři: prof. Ing. Jan Holub, Ph.D.,
  • Publikace: WTS 2011 - Wireless Telecommunications Symposium 2011. New York: IEEE, 2011, pp. 1-2. ISSN 1934-5070. ISBN 978-1-4577-0162-7.
  • Rok: 2011
  • Pracoviště: Katedra měření
  • Anotace:
    The paper presents new results of speech transmission quality measurements obtained by a recently developed algorithm POLQA - ITU-T P.863. Even though the algorithm is declared by its authors as not intended for coding technologies under 4kbit/s, our research shows acceptable accuracy for databases containing significant portion of low bit-rate coded samples, namely by MELPe 2.4 kbit/s.

Impact of Different Active-Speech-Ratios on PESQ`s Predictions in Case of Independent and Dependent Losses

  • Autoři: Počta, P., prof. Ing. Jan Holub, Ph.D., Vlčková, H., Polková, Z.
  • Publikace: Radioengineering. 2010, 19(1), 79-88. ISSN 1210-2512.
  • Rok: 2010
  • Pracoviště: Katedra měření
  • Anotace:
    The relation between Active-Speech-Ratio of input speech sample and PESQ (ITU-T P.862) estimation accuracy is described. It was shown that increasing the ASR may lead to decreasing the PESQ quality prediction accuracy.

Impact of IP Channel Parameters on the Final Quality of the Transferred Voice

  • Autoři: prof. Ing. Jan Holub, Ph.D., Slavata, O.
  • Publikace: MESAQIN 2010. Praha: České vysoké učení technické v Praze, 2010. pp. 18-22. ISBN 978-80-01-04569-5.
  • Rok: 2010
  • Pracoviště: Katedra měření
  • Anotace:
    Impact of IP Channel Parameters on the Final Quality of the Transferred Voice is presented.

Intelligibility in Case Non-native Listeneres and its Dependence on their Language Proficiency

  • Autoři: prof. Ing. Jan Holub, Ph.D., Souček, P.
  • Publikace: MESAQIN 2010. Praha: České vysoké učení technické v Praze, 2010. pp. 23-25. ISBN 978-80-01-04569-5.
  • Rok: 2010
  • Pracoviště: Katedra měření
  • Anotace:
    Intelligibility in Case Non-native Listeneres and its Dependence on their Language Proficiency is described.

Transmitted Speech Quality versus Perceptual Annoyance and Service Acceptibility Thresholds

  • Autoři: prof. Ing. Jan Holub, Ph.D., Počta, P.
  • Publikace: Third International Workshop on Perceptual Quality of Systems. Bochum: ISCA - International Speech Communication Association, 2010. pp. 100-102. ISSN 1680-8908.
  • Rok: 2010
  • Pracoviště: Katedra měření
  • Anotace:
    Transmitted Speech Quality versus Perceptual Annoyance and Service Acceptibility Thresholds is described.

Voice Transmission Quality Measurement Algorithm with Non-native Listener Emulation Capability

  • Autoři: prof. Ing. Jan Holub, Ph.D.,
  • Publikace: Wireless Telecommunications Symposium (WTS), 2010. Pomona, California: IEEE Communications Society, 2010. ISSN 1934-5070. ISBN 978-1-4244-6557-6.
  • Rok: 2010
  • Pracoviště: Katedra měření
  • Anotace:
    Voice transmission quality measurement algorithm with non-native listener emulation capability is described.

Dependency of Subjective Echo Perception on Echo Quality

  • Autoři: prof. Ing. Jan Holub, Ph.D., Dušek, J.
  • Publikace: MESAQIN 2009 Measurement of Speech, Audio and Video Quality in Networks. Praha: CTU Publishing House, 2009. ISBN 978-80-01-04361-5.
  • Rok: 2009
  • Pracoviště: Katedra měření
  • Anotace:
    The paper presents new subjective results of talking quality (TQ) dependency on echo quality for defined return loss and echo delay.

End-to-End Network Simulator for Conversational Quality Measurements

  • Autoři: prof. Ing. Jan Holub, Ph.D., Veřmiřovský, R.
  • Publikace: Digital Technologies 2009. Žilina: University of Žilina, 2009, ISBN 978-80-554-0150-8.
  • Rok: 2009
  • Pracoviště: Katedra měření
  • Anotace:
    End-to-end telecommunication network simulator design and realization is described in the paper. The main applications of the simulator are conversational tests e.g. as per ITU-T P.800 and impairment demonstrations.

End-to-End Network Simulator for Conversational Quality Measurements

  • Autoři: prof. Ing. Jan Holub, Ph.D., Mička, J.
  • Publikace: WTS 2009 Wireless Telecommunications Symposium 2009 Papers and Presentations. Praha: CTU Publishing House, 2009. ISSN 1934-5070. ISBN 978-1-4244-2588-4.
  • Rok: 2009
  • Pracoviště: Katedra měření
  • Anotace:
    End-to-end telecommunication network simulator design and realization is described in the paper. The main applications of the simulator are conversational tests e.g. as per ITU-T P.800 and demonstrations. The simulator can be also used as a replacement of telecommunication chain part that is missing during end-to-end testing or measurements. Examples of achieved subjective test results are presented.

Impact of Different Active-Speech-Ratios on PESQ's Predictions in Simulated VoIP Environment

  • Autoři: Počta, P., prof. Ing. Jan Holub, Ph.D., Mrvová, M.
  • Publikace: ACTA ACUSTICA UNITED WITH ACUSTICA. 2009, 95(5), 950-958. ISSN 1610-1928.
  • Rok: 2009
  • DOI: 10.3813/AAA.918225
  • Odkaz: https://doi.org/10.3813/AAA.918225
  • Pracoviště: Katedra měření
  • Anotace:
    In this work, we experimentally study how behaviour of the PESQ predictions varies with reference signal characteristic. In particular we investigate the impact of different Active-Speech-Ratios on speech quality prediction in simulated VoIP environment from objective and subjective testing point of view.

Speech Quality Aspects and Issues in NNEC

  • Autoři: Blašková, L., prof. Ing. Jan Holub, Ph.D., Novák, J.
  • Publikace: MCC 2009 Military Communications and Information Systems Conference. Brno: Univerzita obrany, 2009, ISBN 978-80-7231-678-6.
  • Rok: 2009
  • Pracoviště: Katedra měření
  • Anotace:
    The first part describes the test methodology and results of speech transmission quality testing in interoperating telecommunication networks where multiple voice coders are in the communication chain (voice transcoding or coder tandeming). The second part focuses on the fact that users are different than regular users of traditional radio networks, namely the language used for the communication is not native either for the speaker and/or for the listener, or the users are under heavy physical or mental stress.

Technical and Phonetic Aspects of Speech Quality Assessment: The Case of Prosody Synthesis

  • Autoři: Tučková, J., prof. Ing. Jan Holub, Ph.D., Duběda, T.
  • Publikace: Lecture Notes in Artificial Intelligence. 2009, 5641(2009931057), 126-132. ISSN 0302-9743.
  • Rok: 2009
  • DOI: 10.1007/978-3-642-03320-9_13
  • Odkaz: https://doi.org/10.1007/978-3-642-03320-9_13
  • Pracoviště: Katedra měření
  • Anotace:
    The present paper proposes a discussion of methods used for subjective assessment of speech quality in technical sciences and in linguistics. Stressing the fact that purely mathematical evaluation of synthetic speech is not sufficient, we try to show that the perspectives and approaches used in the two scientific domains are not necessarily the same. Next we proceed to a pilot experiment consisting in the assessment of synthetic sentences as generated by five different prosodic models, by means of the MOS formalism (ITU-T P.800). The two groups of listeners involved (students of engineering vs. linguistics) provide rather similar results.

How do Non-native Listeners Perceive Quality of Transmitted Voice?

  • Autoři: prof. Ing. Jan Holub, Ph.D., Blašková, L.
  • Publikace: Measurement of Speech, Audio and Video Quality in Networks 2008. Praha: CTU Publishing House, 2008. p. 22-26. ISBN 978-80-01-04193-2.
  • Rok: 2008
  • Pracoviště: Katedra měření
  • Anotace:
    This paper describes the test methodology and results of speech transmission quality testing in the environment of non-native listeners. The subjective tests results confirm systematic and repeatable shift in subjective quality assessment performed by non-native listeners.

How Do Non-native Listeners Perceive Quality of Transmitted Voice?

  • Pracoviště: Katedra měření
  • Anotace:
    The paper describes test methodology and results of speech tranmsission quality testing in the environment of non-native listeners. The tests were carried out based on ITU-T P.800 recommendation on a database of English speech samples affected by various coding distortions and background noise conditions.

Objective and Subjective Degradations of Transcoded Voice - Heterogeneous Radio Networks Interoperability

  • Autoři: prof. Ing. Jan Holub, Ph.D., Tomíška, O.
  • Publikace: DAGA 2008. Dresden: DAGA, 2008. pp. 245-246. ISBN 978-3-9808659-4-4.
  • Rok: 2008
  • Pracoviště: Katedra měření
  • Anotace:
    The objective tests using ITU-T P.862 and P.563 algorithms and subjective tests based on ITU-T P.800 are presented for different transcoded voice cases in coder tandem arrangements.

Transcoded Speech Contemporary Objective Quality Measurements Reliability

  • Autoři: prof. Ing. Jan Holub, Ph.D., Blašková, L.
  • Publikace: WTS 2008 Wireless Telecommunications Symposium. Pomona, California: IEEE Communications Society, 2008. ISSN 1934-5070. ISBN 978-1-4244-1869-5.
  • Rok: 2008
  • Pracoviště: Katedra měření
  • Anotace:
    Speech transcoding (coder tandeming) is unavoidable source of transmission quality degradation for ad-hoc or permanently interoperating networks. Test methodology and results of voice transmission quality measurement for transcoded voice in coder tandem arrangement is described. The objective tests have been performed using ITU-T P.862 (PESQ) and P.563 (3SQM) algorithms. The subjective tests results based on ITU-T P.800 are also presented. The objective results confirm additional degradations caused by abovementioned transcodings, highlighting coder combinations causing extreme impairments. The subjective tests quantify objective measurement accuracy.

Delay Effect on Conversational Quality in Telecommunication Networks: Do We Mind?

  • Autoři: prof. Ing. Jan Holub, Ph.D., Kastner, M., Tomíška, O.
  • Publikace: Wireless Telecommunications Symposium 2007. Pomona, California: IEEE Communications Society, 2007.
  • Rok: 2007
  • Pracoviště: Katedra měření
  • Anotace:
    Transmission delays are unwanted effects of every day telecommunication systems. These effects influence the overall quality of a telephony connection as perceived by end users. This article summarizes known subjective experiments testing the influence of delays on the perceived quality. In order to find a possible explanation for the differences in the results of those experiments a new conversational test was conducted. The new subjective tests are also presented and compared to already existing experiment results.

Intrusive Speech Transmission Quality Measurement in Chinese Environment

  • Autoři: prof. Ing. Jan Holub, Ph.D., Liu, J.J.
  • Publikace: Sixth International Conference on Information, Communications and Signal Processing ICICS 2007. Singapore: Nanyang Technological University, 2007. ISBN 1-4244-0983-7.
  • Rok: 2007
  • Pracoviště: Katedra měření
  • Anotace:
    This paper describes testing of speech transmission quality measurement algorithm in Chinese environment, comparing ITU-T P.862 PESQ-LQ and subjective listening quality results for various types of contemporary speech coders and distortions.

Non-monotonicity in Perceived Quality of Delayed Talker Echo

  • Autoři: prof. Ing. Jan Holub, Ph.D., Tomíška, O.
  • Publikace: Measurement of Speech, Audio and Video Quality in Networks. Prague: Czech Technical University, 2007. p. 67-68. ISBN 978-80-01-03734-8.
  • Rok: 2007
  • Pracoviště: Katedra měření
  • Anotace:
    Transmission delays are unwanted effects of every day telecommunication systems. These effects influence the overall quality of a telephony connection as perceived by end users. This article summarizes known subjective experiments testing the influence of delays on the quality perceived by end-users. In order to find a possible explanation for the differences in the results of those experiments a new conversational test was conducted. The new subjective tests are also presented and compared to already existing experiment results.

A Novel Non-Intrusive Voice Transmission Quality Measurement Algorithm

  • Autoři: prof. Ing. Jan Holub, Ph.D., Street, M., Tomíška, O.
  • Publikace: WTS 2006 - Wireless Telecommunications Symposium 2006. Piscataway: IEEE, 2006. ISBN 1-4244-0046-5.
  • Rok: 2006
  • Pracoviště: Katedra měření
  • Anotace:
    A new, wavelet-based, non-intrusive method for speech transmission quality measurements is described in the abstract. The Discrete Wavelet Transform, unlike a Fourier Transform, enables a significant reduction in the computational power required. In comparison with standardized methods (based on ITUT P.563 algorithms), the described method saves about 90% of the operations needed, achieving about 90% of the results of P.563. Thus, it is suitable for continuous assessment, or even for applications embedded in the mobile terminal.

Computationally Efficient Non-Intrusive Algorithm for Speech Transmission Quality Measurement

  • Autoři: prof. Ing. Jan Holub, Ph.D., Street, M., Tomíška, O.
  • Publikace: IMEKO - XVIII World Congress and IV Brazilian Congress of Metrology. Rio de Janeiro: IMEKO, 2006.
  • Rok: 2006
  • Pracoviště: Katedra měření
  • Anotace:
    A new, wavelet-based, non-intrusive method for speech transmission quality measurements is described in the abstract. It models human perception of quality of transmitted speech signal. The deployed Discrete Wavelet Transform, in comparison with Fourier Transform, enables to reduce the computational power. In comparison with standardized methods (based on ITU-T P.563 algorithms), the described method saves about 90% of operations needed, achieving about 90% of the results of P.563. Thus, it is suitable for operational continuous assessment, or even for applications embedded in the mobile terminal.

Conversation Quality Assessment

  • Autoři: Tomíška, O., prof. Ing. Jan Holub, Ph.D.,
  • Publikace: Nové smery v spracovaní signálov VIII. - Zborník príspevkov medzinárodnej vedeckej konferencie. Tatranské Zruby: Akadémia ozbrojených síl gen. M. R. Štefánika, 2006. pp. 305-309.
  • Rok: 2006
  • Pracoviště: Katedra měření
  • Anotace:
    The only way how to estimate conversation quality today is performing subjective conversation test. This test has been performed in CVUT, FEE, K13838. A proprietary end-to-end DSP-based network simulator has been developed to enable the performance of these tests. The test results can be directly used for design and verification of objective estimator of conversational quality.

Conversation Quality Assessment

  • Autoři: Tomíška, O., prof. Ing. Jan Holub, Ph.D.,
  • Publikace: Nové smery v spracovaní signálov VIII. Medzinárodná vedecká konferencia. Tatranské Zruby: Akadémia ozbrojených síl gen. M. R. Štefánika, 2006. pp. 305-309. ISBN 80-8040-294-9.
  • Rok: 2006
  • Pracoviště: Katedra měření
  • Anotace:
    The only way how to estimate conversation quality today is performing subjective conversation test. This test has been performed in CVUT, FEE, K13838. A proprietary end-to-end DSP-based network simulator has been developed to enable the performance of these tests. The test results can be directly used for design and verification of objective estimator of conversational quality.

Non-Intrusive Voice Transmission Quality Objective Estimator for Devices with Limited Computational Power

  • Autoři: prof. Ing. Jan Holub, Ph.D., Tomíška, O.
  • Publikace: Digital Signal Processing and its Applications. Moskva: IEEE, 2006. p. 623-626.
  • Rok: 2006
  • Pracoviště: Katedra měření
  • Anotace:
    The developed algorithm is suitable for operational quality measurement where massive amount of call records must be evaluated. Due to the low computational power required by the algorithm, it is possible to embed such an application directly in mobile terminals (where the computational power as well as battery life and available memory space are limited).

Objective Assessment of Speech Distribution Quality by means of Unconventional PESQ Application - A Case Study

  • Pracoviště: Katedra měření
  • Anotace:
    The article describes non-traditional deployment of ITU-T P.862 (PESQ) algorithm for quality assessment of speech distribution. Subjective and objective results are presented and compared.

Proprietary Low Bit-rate Radio-communication Network - Objective and Subjective Speech Transmission Quality Assessment

  • Autoři: prof. Ing. Jan Holub, Ph.D., Drozdová, A.
  • Publikace: Measurement of Speech and Audio Quality in Networks. Prague: Czech Technical University, 2006. p. 63-66. ISBN 80-01-03262-0.
  • Rok: 2006
  • Pracoviště: Katedra měření
  • Anotace:
    Test design and results of subjective, PESQ and 3SQM testing in low-bit rate network is given.

Measurements of ADCs Effective Resolution

  • Autoři: prof. Ing. Jan Holub, Ph.D., Neškudla, J., doc. Ing. Josef Vedral, CSc.,
  • Publikace: ADDA 2005 - The 5th IEE International Conference on Advanced A/D and D/A Conversion Techniques and their Applications. Limerick: The IEE Measurement, Sensors, Instrumentation and NDT Professional Network, 2005. p. 255-257. ISBN 0-86341-542-3.
  • Rok: 2005
  • Pracoviště: Katedra měření
  • Anotace:
    The article describes some aspects of understanding, defining and measurements of high effective resolution of ADC in Microconvertor ADUC834. The disadvantages and misleading results of commonly used definition are shown and possible solutions are discussed. Finally, one new solution is given and arguments for its correctness and usability are collected.

Měření kvality přenosu hlasu v neveřejných sítích

  • Pracoviště: Katedra měření
  • Anotace:
    Měření kvality přenosu hlasových signálů v neveřejných sítích přináší řadu nových problémů a nároků kladených na měřicí algoritmy. V článku je představen měřící algoritmus vyvinutý na katedře měření FEL ČVUT.

Methodology for Voice Transmission Measurement Systems Verification

  • Pracoviště: Katedra měření
  • Anotace:
    Set of tests designed for VTQOS system verification is proposed, including examples and practical reasons for this selection.

Mobile Network Voice Transmission Quality Estimation based on Radio Path Parameters

  • Autoři: Doležalová, B., prof. Ing. Jan Holub, Ph.D., Street, M.
  • Publikace: Wireless Telecommunications Symposium 2005 - Proceedings. Pomona, California: IEEE Communications Society, 2005. ISBN 0-7803-8857-7.
  • Rok: 2005
  • Pracoviště: Katedra měření
  • Anotace:
    The article describes design, development and test results of a voice transmission quality estimating algorithm that offers results (MOS estimates) comparable to intrusive speech quality measurements but which employs different techniques - analyzing radio path parameters only.

Testing of ADCS with Noise Signal

  • Pracoviště: Katedra měření
  • Anotace:
    High-linearity and high-resolution AD converters that are difficult to test by standard methods using deterministic signal [1] can be tested by means of stochastic test methods. Histogram test can use various input signals and principally allows use noise as the input signal. To overcome difficulties related to generation of large-scale uniformly distributed stochastic signal, a method based on superposition of Gaussian noises with equidistantly spaced DC shifts has been proposed and theoretical analysis has been provided in [2]. In current development stage, it can host the following 16-bits ADCs with SAR transfer technology.

A Dependence between Average Call Duration and Voice Transmission Quality: Measurement and Applications

Dynamic Parameters Testing of 24-bit Resolution ADCs

High Resolution ADC Data Acquisition System

Impact of End to End Encryption on GSM Speech Transmission Quality - a Case Study

  • Autoři: prof. Ing. Jan Holub, Ph.D., Street, M.D.
  • Publikace: The 2nd IEE Secure Mobile Communications Forum. London: IEE, 2004. p. 6/1-6/4. ISSN 0537-9989. ISBN 0-86341-461-3.
  • Rok: 2004

Measurements of Effective Resolution of ADC in Microconverter ADUC834

  • Autoři: doc. Ing. Josef Vedral, CSc., prof. Ing. Jan Holub, Ph.D.,
  • Publikace: DDECS - Proceedings of 7th IEEE Design and Diagnostics of Electronic Circuits and Systems Workshop. Stará Lesná: Institute of Informatics, Slovak Akademy of Sciences, Bratislava, 2004. pp. 255-258. ISBN 80-969117-9-1.
  • Rok: 2004

Processing Power Optimisation for PESQ

  • Pracoviště: Katedra měření
  • Anotace:
    This article identifies several areas of possible reduction of processing power requirements of the PESQ algorithm (ITU-T P.862). As a result, PDA-based implementation of PESQ-based speech transmission quality measurement system for GSM networks is presented and required computational times are discussed.

Step Gauss Test - New Method for Testing of ADCs

Stochastic Test of 24 bit-AD Converter - Case Study

Stochastic Test of 24 bit-AD Converter - Case Study

Stochastic Testing of ADC - Step-Gauss Method

Zkoumání morfologických reakcí spinálních ganglií metodami 3D mikroskopie

  • Pracoviště: Katedra měření
  • Anotace:
    Příspěvek popisuje metody získávání třídimenzionálních obrázků objektů ze dvoudimenzionálních obrazů snímaných optickým mikroskopem. Výsledek číslicového zpracování obrazových signálů je kompletní 3D ostrý obrázek objektu získaný jako kombinace zaostřených částí jednotlivých obrazů. Metody jsou aplikovány pro výzkum morfologických reakcí spinálních ganglií na neurotoxické látky.

Application of Noise Signal for Testing High Resolution ADCs

Child Listeners as the Test Subject - Comparison with Adults and P.862

Dynamic Testing of 16 bit ADC with Sinewave and Stochastic Signals

IN-based Measurements of Voice Transmission Quality in Mobile Networks

  • Autoři: prof. Ing. Jan Holub, Ph.D.,
  • Publikace: Proceedings of Workshop 2003. Praha: České vysoké učení technické v Praze, 2003, pp. 472-473. ISBN 80-01-02708-2.
  • Rok: 2003

Intrusive Speech Transmission Quality Measurements for Low Bit-Rate Coded Audio Signals

Low Bit-rate Networks - A Challenge for Intrusive Speech Transmission Quality Measurements

  • Autoři: prof. Ing. Jan Holub, Ph.D., Street, M.D.
  • Publikace: Measurement of Speech and Audio Quality in Networks. Praha: České vysoké učení technické v Praze, 2003, pp. 47-49. ISBN 80-01-02822-4.
  • Rok: 2003

Step-Gauss Stochastic Testing Method Application for Transportable Reference ADC Device

Stochastic Test Method Application for 16-Bit Reference ADC Device

Stochastic Test Method Application for 16-Bit Reference ADC Device

  • Autoři: prof. Ing. Jan Holub, Ph.D., Komárek, M., Kříž, M., doc. Ing. Josef Vedral, CSc.,
  • Publikace: Measurement 2003 - Proceedings of the 4th International Conference on Measurement. Bratislava: Slovak Academy of Sciences, Institute of Measurement Science, 2003. pp. 95-98. ISBN 80-967402-6-1.
  • Rok: 2003

Testing of High Resolution ADCs with Deterministic and Stochastic Signals

Voice Transmission Quality Measurement Based on Wavelet Transformation

Voice Transmission Quality Measurement Based on Wavelet Transformation

Wavelet Transform in Voice Transmission Quality Measurements

A Novel Intrusive Voice Transmission Quality Test System for Mobile Networks

Aspects of ADC Effective Resolution: Definitions and Measurements

Aspects of ADC Effective Resolution: Definitions and Measurements

Comparison of Methods for Testing of Analog-to-Digital Converters

  • Autoři: prof. Ing. Jan Holub, Ph.D., Kubín, M.
  • Publikace: ETW'02 - 7th IEEE European Test Workshop. Athens: University of Athens, 2002. pp. 207-208.
  • Rok: 2002

Comparison of Parameters of Systems Used for AD Converters and Modules Testing

Data Processing and Dither Enhancement of ADC Parameters - Trends, Applications, Limits

  • Autoři: prof. Ing. Jan Holub, Ph.D., Aumala, O.
  • Publikace: ADDA & EWADC 2002. Praha: České vysoké učení technické v Praze, 2002. pp. 127-134. ISBN 80-01-02540-3.
  • Rok: 2002

Data Processing and Dither Enhancement of ADC Parameters - Trends, Applications, Limits

  • Autoři: prof. Ing. Jan Holub, Ph.D., Aumala, O.
  • Publikace: ADDA & EWADC 2002. Praha: České vysoké učení technické v Praze, 2002. pp. 127-134. ISBN 80-01-02540-3.
  • Rok: 2002

Echo Measurement in Mobile Networks

  • Autoři: prof. Ing. Jan Holub, Ph.D., Prošek, D.
  • Publikace: Proceedings of Workshop 2002. Praha: České vysoké učení technické v Praze, 2002. pp. 444-445. ISBN 80-01-02511-X.
  • Rok: 2002

High Resolution ADC Testing by Means of Standard Test Methods

Histogram Test of Sigma Delta ADC

Improvement of Step-Gauss ADC Stochastic Test Method

  • Autoři: Kubín, M., prof. Ing. Jan Holub, Ph.D.,
  • Publikace: Proceedings of Workshop 2002. Praha: České vysoké učení technické v Praze, 2002. pp. 458-459. ISBN 80-01-02511-X.
  • Rok: 2002

Improvement of Stepp-Gauss ADC Stochastic Test Method

Improvement of Stepp-Gauss ADC Stochastic Test Method

Intrusive Speech Quality Measurements in Czech Environment

Intrusivní měření kvality přenosu hlasu v sítích mobilních prostředků

  • Autoři: prof. Ing. Jan Holub, Ph.D.,
  • Publikace: Nové smery v spracovaní signálov VI - kniha 1. Liptovský Mikuláš: Vojenská akadémia, 2002, pp. 104-107. ISBN 80-8040-180-1.
  • Rok: 2002

Methods for Testing of High Resolution ADC

Standard sériového rozhraní pro měřicí přístroje

Stochastic Testing Signals in ADC Testing

Time versus Frequency-Domain Methods for High Resolution ADC Testing

Voice Transmission Quality - On-line Workshop

Voice Transmission Quality Measurement

ADC Testing by Means of Stochastical Signal

Advanced Measurements in Mobile Networks

Combined Testing Signal for ADC Histogram Test

Complex Measurement Laboratory Exercising

Digital Oscilloscopes Testing System

Electronic Measuring Circuits Laboratory Exercises at Dept. of Measurement of FEE CTU

Evaluation of Frequency Dependence of Effective Number of Bits by means of Stochastic Testing Signal

Evaluation of Frequency Dependence of Effective Number of Bits by means of Stochastic Testing Signal

Hodnocení hlasových přenosů v telekomunikačních sítích

How to Exercise Complex Measurements

How to Exercise Complex Measurements

Measurement of Voice Transmission Quality in Mobile Networks

Measuring System for Testing of Digital Oscilloscopes

Metrological Aspects of Digital Oscilloscopes

Oscilloscope Testing by Means of Stochastic Signal

Přenos hlasu v moderních telekomunikačních sítích - měření kvality

Sensors Linearity Improvement by Means of Dithering: Feasibility and Limits

Sensors Linearity Improvement by Means of Dithering: Feasibility and Limits

Stochastic Testing of A/D Converters-Step-Gauss Method

ADC Testing Using Combined Test Signal

Information Transfer of Dithered A/D Converters

  • Autoři: Aumala, O., prof. Ing. Jan Holub, Ph.D.,
  • Publikace: XVI IMEKO World Congress IMEKO 2000 - EWADC'2000. Wien: TU Wien, Abteilung Austauschbau und Messtechnik, 2000. pp. 45-50. ISBN 3-901888-12-8.
  • Rok: 2000

Large Scale Error Reduction in Dithered ADC

  • Autoři: prof. Ing. Jan Holub, Ph.D., Aumala, O.
  • Publikace: XVI IMEKO World Congress IMEKO 2000 - EWADC'2000. Wien: TU Wien, Abteilung Austauschbau und Messtechnik, 2000. pp. 171-176. ISBN 3-901888-12-8.
  • Rok: 2000

Measuring of Effective Resolution of Sigma-Delta ADC

Measuring of Effective Resolution of Sum-Delta ADC

Mobile Networks: Advanced Measurements and Special Applications

Nové výsledky v oblasti testování dynamických vlastností AČ modulů

Practical Experience with Linearity Improvement in Dithered ADC

Signal Source for Statistical Testing of ADC

Statistical Method for Testing of Sigma-Delta Converters

Statistical Testing of Sigma Delta ADCs

Stochastic Testing of Analog-to-Digital-Converters

Stochastic Testing Signals in ADC Testing

Stochastické metody testování analogově-číslicových převodníků

  • Autoři: prof. Ing. Jan Holub, Ph.D.,
  • Publikace: EE - Odborný časopis pre elektrotechniku a energetiku. 2000, 6 74-76. ISSN 1335-2547.
  • Rok: 2000

Testing of Digital Oscilloscopes

Various Scale Errors in Dithered Quantizers. Visualisation and Reduction

Vlastnosti analogových vstupů mikropočítače 80552

Využití protokolu WAP a jazyka WML v měřicí a řídicí technice

A New Time-Saving Method for ADC Testing

A Quadrature Bridge for QHE-Based Calibration of Capacitance Standards

Application of Sensor Fusion Principle for Positioning System Improvement

Aspects of Quantization in Digital Measurement

  • Autoři: prof. Ing. Jan Holub, Ph.D.,
  • Publikace: Proceedings of Workshop 99. Praha: České vysoké učení technické v Praze, 1999. pp. 211.
  • Rok: 1999

Chirp Based Method for ADC Testing: Simulation and Evaluation

High-Resolution Multiplexing Analog-to-Digital Module

  • Autoři: prof. Ing. Jan Holub, Ph.D., doc. Ing. Josef Vedral, CSc.,
  • Publikace: 8th Scientific Conference Theoretical Electrical Engineering and Electrical Measurement. Košice: Dep. of Theoretical Electrical Engineering and El. Measurement FEI TU of Košice, 1999. pp. 109-116.
  • Rok: 1999

Introduction to New Trends in ADC Testing

  • Autoři: prof. Ing. Jan Holub, Ph.D.,
  • Publikace: Poster 1999. Praha: České vysoké učení technické v Praze, Fakulta elektrotechnická, 1999. pp. 50-51.
  • Rok: 1999

Intrusivní měření v sítích GSM

  • Pracoviště: Katedra měření
  • Anotace:
    Třetí díl seriálu je věnován intrusivním měřením v sítích GSM. Pojem "intrusivní" naznačuje, že při těchto měřeních je sledována odezva sítě GSM na specifické podněty, které jsou měřicím přístrojem generovány pouze pro účel měření. Intrusivní měření lze rozdělit na dvě skupiny: zátěžové a provozní testy a intrusivní měření kvality služeb.

Měření na rádiovém rozhraní sítě GSM

  • Pracoviště: Katedra měření
  • Anotace:
    Pokračování série článků je věnováno měření na rozhraní Um, neboli na rádiovém rozhraní sítě, které spojuje mobilní stanice (MS) se základnovými stanicemi BTS. V minulém dílu bylo stručně popsáno dělení kmitočtového spektra v systému GSM a principy TDMA a FDMA. Detailní popis rozhraní Um je k dispozici v jeho specifikaci ETSI-GSM Rec. 04.04. Připomeňme pouze, že každý ze 124 kmitočtových kanálů je principem TDMA dělen na 8 časových kanálů. Délka každého časového kanálu (Burst Period) je 577 mikrosekund. Během této doby je přeneseno 156,25 bitu, z toho 114 bitů užitečných dat. Je použita 4-stavová modulace 0,3-GSMK.

Měření v sítích GSM

  • Pracoviště: Katedra měření
  • Anotace:
    Mobilní komunikace jsou v posledním desetiletí bezesporu nejúspěšnějším a nejrychlesi se rozvíjejícím odvětvím. V evropském regionu jednoznačně převládá standard GSM. V situaci, kdy v liberalizovaném prostředí si lze jen těžko představit další výrazné snižování cen mobilních služeb, může být další konkurenční výhodou jejich kvalita a spolehlivost zajišťovaná vhodnými postupy měření a monitorování sítě.

Neintrusivní měření v sítích GSM

  • Pracoviště: Katedra měření
  • Anotace:
    Pojem "neintrusivní" naznačuje, že při těchto měřeních nejsou měřicím přístrojem generovány žádné umělé podněty, pouze je pasivně monitorován reálný provoz sítě (přenosy hovorů a související signalizace). Získaná data jsou potom podrobena dalšímu zpracování a výsledkem jsou buď různé statistické ukazatele, nebo úzká vybraná skupina záznamů, vhodná např. pro analýzu určitého problému nebo pro určení vadné části (prvku) sítě.

Statistical Method for Testing of Sigma-Delta Converters

Testing of High-Resolution Multiplexing A/D Converters

Trojrozměrné měření a popis tvaru v mikroskopii biologických vzorků

  • Pracoviště: Katedra měření
  • Anotace:
    Článek přibližuje vybrané metody pro trojrozměrné (dále jen 3D) mikroskopické snímání biologických objektů a popis jejich tvaru pro účely měření a hodnocení tvarových změn.

Využití MATLABu ve výuce Zpracování signálů na katedře měření ČVUT FEL

  • Pracoviště: Katedra měření
  • Anotace:
    Na katedře měření FEL ČVUT se v rámci cvičení předmětů Zpracování signálů a obrazů a Vybrané metody digitalizace signálu používá program MATLAB s toolboxy Signal Processing a Wavelets, které obsahují sadu funkcí zabývajících se analýzou a syntézou signálů. Byla vytvořena interaktivní rozhraní např. pro základní seznámení s rychlou Fourierovou transformací, návrh číslicových filtrů typu FIR a IIR z průběhu jejich přenosové charakteristiky, demonstrace výpočtů vzájemné korelační a autokorelační funkce, atd.

A Novel Low-Cost Dithering Application for ADC in Single-Chip

  • Autoři: prof. Ing. Jan Holub, Ph.D.,
  • Publikace: Dithering in Measurement: Theory and Applications. Praha: ČVUT FEL, Katedra měření, 1998, pp. 29-33. ISBN 80-01-01806-7.
  • Rok: 1998

Dithering Design for Measurement of Slowly Varying Signals

Full-Test of Performance of ADC Input in Single-Chip Microcontrollers

Linearization of Transfer Characteristics of A/D Converters Using Dithering

  • Pracoviště: Katedra měření
  • Anotace:
    Linearizace převodních charakteristik A/D převodníků přídavným signálem

Metrologic Parameters Improvement of ADC in Single-Chip Microcontroller

  • Autoři: prof. Ing. Jan Holub, Ph.D.,
  • Publikace: Poster 1998. Praha: České vysoké učení technické v Praze, Fakulta elektrotechnická, 1998. pp. 13-14.
  • Rok: 1998

Možnosti zvyšování přesnosti AD převodu přídavným signálem

  • Autoři: prof. Ing. Jan Holub, Ph.D.,
  • Publikace: Aplikovaná elektronika 98. Plzeň: Západočeská universita, 1998, pp. 54-57. ISBN 80-7082-443-3.
  • Rok: 1998
  • Pracoviště: Katedra měření
  • Anotace:
    Číslicovou filtrací sady výstupních slov AD převodníku, na jehož vstup je přiveden součet měřeného a vhodně zvoleného přídavného signálu, lze dosáhnout zvýšení přesnosti (tj. rozlišovací schopnosti a linearity) na úkor sníženého efektivního vzorkovacího kmitočtu. Teoretické možnosti tohoto postupu však v praxi narážejí na chyby reálných AD převodníků, které zhoršují výsledné parametry. Jsou prezentovány výsledky experimentů, prováděných na zásuvných měřicích kartách do PC a na jednočipových mikropočítačích s AD převodníkem na čipu.

Praktické použití Internetu jako média pro virtuální konferenci

  • Pracoviště: Katedra měření
  • Anotace:
    Virtuální konference pořádané pomocí Internetu představují atraktivní a efektivní metodu pro výměnu vědeckých informací. Její základní výhodou je rychlost, úspora nákladů na cestovné a ubytování účastníků. Je však nutné řešit problémy s uznáváním příspěvků vědeckou komunitou a s nedostatkem interpersonálních kontaktů.

Pros and Cons of On-line Workshop Held Using Internet Technology

Testing of Dynamic Performance of ADC Input in Single-Chip Microcontrollers

Virtuální internetová konference Dithering in Measurement: Theory and Applications

Visualisation and Reduction of Various Scale Errors in Dithered Quantizers

Visualisation of Errors of Dithered Quantizer Using Continuous Wavelet Transform

Application of Dithering for ADC Plug-in Cards Accuracy Enhancement

  • Autoři: prof. Ing. Jan Holub, Ph.D.,
  • Publikace: Measurement '97 Proceedings. Bratislava: Slovak Academy of Sciences, Institute of Measurement Science, 1997, pp. 39-42. ISBN 80-967402-1-0.
  • Rok: 1997

Dithered Quantizer of ADC Plug-In Card: Theoretical Model and Practical Testing

Měřicí systém s korekcí nelinearit a adaptivní rozlišitelností na bázi zásuvné měřicí karty do PC

Metrological Reliability of Dithered Quantizer of Plug-in Card for PC

  • Autoři: prof. Ing. Jan Holub, Ph.D.,
  • Publikace: Poster 1997. Praha: České vysoké učení technické v Praze, Fakulta elektrotechnická, 1997. pp. 23-24.
  • Rok: 1997

Návrh integrovaných analogových filtrů počítačem

Využití spínaných filtrů v měřicí technice

Zvýšení rozlišovací schopnosti AD převodníku pomocí ditheringu

Shift in speech quality and acceptability level between 2008-2012

  • Pracoviště: Katedra měření
  • Anotace:
    This paper presents results of quality and acceptability level tests, performed on similar groups of listeners with two years span in years 2008, 2010 and 2012. It shows shift in both quality and acceptability level and compares them. The tests were conducted according to P.800.

Za stránku zodpovídá: Ing. Mgr. Radovan Suk