Wyniki wyszukiwania - BazTech

1

A Video-Based Fall DetectionUsing 3D Sparse Convolutional Neural Networkin Elderly Care Services

Fu Fangping

Machine Graphics and Vision

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2025

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Vol. 34, No. 1

53--74

EN

Falls in the elderly have become one of the major risks for the growing elderly population. Therefore, the application of automatic fall detection system for the elderly is particularly important. In recent years, a large number of deep learning methods (such as CNN) have been applied to such research. This paper proposed a sparse convolution method 3D Sparse Convolutions and the corresponding 3D Sparse Convolutional Neural Network (3D-SCNN), which can achieve faster convolution at the approximate accuracy, thereby reducing computational complexity while maintaining high accuracy in video analysis and fall detection task. Additionally, the preprocessing stage involves a dynamic key frame selection method, using the jitter buffers to adjust frame selection based on current network conditions and buffer state. To ensure feature continuity, overlapping cubes of selected frames are intentionally employed, with dynamic resizing to adapt to network dynamics and buffer states. Experiments are conducted on Multi-camera fall dataset and UR fall dataset, and the results show that its accuracy exceeds the three compared methods, and outperforms the traditional 3D-CNN methods in both accuracy and losses.

2

The True Random Number Generator design using a high-noise oscillator

Butryn Igor, Derlecki Mariusz, Łuczyk Arkadiusz, Jasiński Jakub, Wielgus Andrzej, Siwiec Krzysztof

International Journal of Electronics and Telecommunications

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2025

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Vol. 71, No. 4

24

EN

The growing importance of creating appropriate safeguards in electronic systems forces design of integrated circuits dedicated for cryptographic purposes. The paper focuses on True Random Number Generator (TRNG) circuits design allowing generation of random bit stream. Presented TRNG architecture uses low frequency high-noise oscillator for sampling high frequency clock signal. The article also describes a method for obtaining a high noise level in the oscillator. Achieved bit rate of designed TRNG equals 1 Mb/s. The circuit dissipates 144 μW. The design of the TRNG, simulation and measurement results of the manufactured IC chips have been described in the paper also. TRNG circuit has been implemented in 180 nm CMOS technology.

3

SPAD timing jitter modeling using Fourier series

Eyvazi Kaveh, Karami Mohammad Azim

Optica Applicata

|

2023

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Vol. 53, nr 2

239--248

EN

In this paper, a simple analytical model for the Gaussian’s peak response part of the timing jitter of single photon avalanche diodes (SPADs) is proposed using Fourier series in the multiplication time calculation. The multiplication time characterizes avalanche multiplication process speed in which low multiplication time suggests a swifter response time and a higher avalanche speed. This paper presents an analytical solution which results in a more accurate multiplication time. The model is verified for SPADs implemented in 0.15 and 0.18 μm standard CMOS process, and the accuracy of the proposed analytical method in full-width at half-maximum (FWHM) calculation is improved by 25% and 5% with respect to the numerical model, respectively.

4

Open concurrent network communication methods in building distributed web applications

Buchwald Paweł, Dawid Aleksander

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2021

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Vol. 25, No 4

409--418

EN

The attractiveness of real-time multimedia communication as part of an e-learningplatform largely depends on the quality of the telecommunications infrastructure and on theservices that support the exchange of audiovisual data. The research subject of this workis communication between stationary and mobile devices using distributed services such asWeb Real-Time Communication (WebRTC) running in HTML5 compliant web browsers. Thetest connections were carried out in a peer-to-peer architecture over a local wireless WiFinetwork and a mobile network supporting the Long Term Evolution (LTE) standard fordata interchange. Several audiovisual sessions between two clients were analyzed for differentconnection scenarios. Parameters responsible for the transmission quality, such as delay, jitter,packet loss, or the speed of sending and receiving video frames were measured for each scenario.Open audiovisual communication system performance experiments were conducted under realoperating conditions. The obtained results indicated potential applications in the developmentof e-learning websites.

5

Współczesne metody i układy generacji taktów zegarowych o wysokiej dokładności i stabilności oraz znikomym jitterze

Leśniewicz Marek

Przegląd Elektrotechniczny

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2021

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R. 97, nr 7

98--105

PL

W artykule przedstawiono wyniki prac nad wykorzystaniem sygnałów GNSS do generacji taktów zegarowych o wysokiej dokładności i stabilności oraz o znikomym jitterze. Intencją tych prac było opracowanie prostego i taniego modułu, oddającego referencyjne sygnały dla przyrządów pomiarowych oraz urządzeń telekomunikacyjnych. Badania przeprowadzono na samodzielnie skonstruowanych modułach, zawierających najnowsze rozwiązania w dziedzinie odbioru sygnałów GNSS i technik redukcji jittera. Wyniki badań udokumentowano pomiarowo.

EN

The article presents the results of work on the use of GNSS signals to generate clock cycles with high accuracy and stability, and with negligible jitter. The intention of these works was to develop a simple and inexpensive module that would provide reference signals for measuring instruments and telecommunications devices. The research was carried out on self-constructed modules containing the latest solutions in the field of GNSS signal reception and jitter reduction techniques. The test results were documented by measurement.

6

Jitter generation model based on timing modulation and cross point calibration for jitter decomposition

Ren Nan, Fu Zaiming, Lei Shengcu, Liu Hanglin, Tian Shulin

Metrology and Measurement Systems

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2021

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Vol. 28, nr 1

123--143

EN

High-speed serial standards are rapidly developing, and with a requirement for effective compliance and characterization measurement methods. Jitter decomposition consists in troubleshooting steps based on jitter components from decomposition results. In order to verify algorithms with different deterministic jitter (DJ) in actual circuits, jitter generation model by cross-point calibration and timing modulation for jitter decomposition is presented in this paper. The generated jitter is pre-processed by cross-point calibration which improves the accuracy of jitter generation. Precisely controllable DJ and random jitter (RJ) are generated by timing modulation such as data-dependent jitter (DDJ), duty cycle distortion (DCD), bounded uncorrelated jitter (BUJ), and period jitter (PJ). The benefit of the cross-point calibration was verified by comparing generation of controllable jitter with and without cross-point calibration. The accuracy and advantage of the proposed method were demonstrated by comparing with the method of jitter generation by analog modulation. Then, the validity of the proposed method was demonstrated by hardware experiments where the jitter frequency had an accuracy of ±20 ppm, the jitter amplitude ranged from 10 ps to 8.33 ns, a step of 2 ps or 10 ps, and jitter amplitude was independent of jitter frequency and data rate.

7

High performance optical shutter design with scalable aperture

Pokryszka Piotr, Wośko Mateusz, Kijaszek Wojciech, Paszkiewicz Regina

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2021

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Vol. 69, nr 5

art. no. e138236

EN

In this paper, design, construction and switching parameters of a self-made optical shutter with scalable aperture were reported. The aim of the study was to obtain the shortest possible switching times, minimum shutter open time and comparable with commercial shutter, the switch-on and switch-off times. For this purpose, numerical simulations were performed using Comsol Multiphysics 5.4. The design of the shutter and the control system have been optimized accordingly to the obtained results of numerical simulations. The optimized design was fabricated in a professional mechanical workshop and operational parameters of the constructed device were investigated. The switching parameters of the shutter, such as opening time, closing time, minimum shutter open time and other parameters were measured. The values of the parameters were determined from a statistical analysis of a sample consisting of 10,000 measurement results. The performed characterization showed that the tested device has the opening time of 0.8 ms, while the closing time is approximately 1 ms. The designed device is characterized by the minimum shutter open time of 6.4 ms.

8

Permutation Coding with Injections for Modified PAM System

Ogunyanda Opeyemi O., Shongwe Thokozani, Swart Theo G.

International Journal of Electronics and Telecommunications

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2020

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Vol. 66, No. 3

399--404

EN

Arriving at a good combination of coding and modulation schemes that can achieve good error correction constitutes a challenge in digital communication systems. In this work, we explore the combination of permutation coding (PC) and pulse amplitude modulation (PAM) for mitigating channel errors in the presence of background noise and jitter. Since PAM is characterised with bi-polar constellations, Euclidean distance is a good choice for predicting the performance of such coded modulation setup. In order to address certain challenges facing PCs, we therefore introduce injections in the coding system, together with a modified form of PAM system. This modification entails constraining the PAM constellations to the size of the codeword’s symbol. The results obtained demonstrate the strength of the modified coded PAM system over the conventional PC coded PAM system.

9

Intonation accuracy and pitch stability during crescendo as the voice quality and singer’s experience indicator among choral singers

Gawlik Mateusz, Wszołek Wiesław

Vibrations in Physical Systems

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2019

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Vol. 30, nr 1

art. no. 2019138

EN

The ability to correctly reproduce notes by the voice is one of the essential features of the singing task and called intonation. In combination with other parameters like timbre, formants, and sound attack, it affects the reception of listening impressions. In this paper, we present results of the examination concerning the automatic evaluation of intonation among the nonsingers, untrained and trained choral singers. We performed both pitch error during vocalization and pitch stability in crescendo task analysis among studied groups. We used Zero Band Filtering method to determine fundamental frequency from the singing signal. We noticed significant differences between singers with different skills and experience, and the possibility to classify the level of advancement of the singer by using intonation characteristic.

10

Fractional order model of measured quantity errors

Cioć R., Chrzan M.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2019

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Vol. 67, nr 6

1023--1030

EN

The paper presents an interpretation of fractional calculus for positive and negative orders of functions based on sampled measured quantities and their errors connected with digital signal processing. The derivatives as a function limit and the Grunwald-Letnikov differintegral are shown in chapter 1 due to the similarity of the presented definition. Notation of fractional calculus based on the gradient vector of measured quantities and its geometrical and physical interpretation of positive and negative orders are shown in chapter 2 and 3.

11

GNSS-based sound card synchronization

Carôt Alexander, Mahmood Hasan, Hoene Christian

Annals of Computer Science and Information Systems

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2019

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Vol. 18

309-–312

EN

Audio communication on the public Internet suffers from not synchronized word clocks of the involved audio devices. The resulting clock drift leads to audio dropouts, which is typically compensated by a sample rate conversion (SRC) in standard telecommunication systems. This, however, does not fulfill the requirements of a high-quality audio system, in which all devices share one and the same word clock. Professional IP based network audio systems such as DANTE or AVB with their respective clock synchronization techniques have so been limited to LAN usage, where network jitter and loss have negligible importance regarding the required accuracy in the dimension of several nanoseconds. In a WAN, however, jitter in the millisecond dimension would lead to unacceptable measurement errors for the intended clock synchronization. As a consequence, we decided to investigate alternative clock synchronization techniques for WAN-distributed devices and developed a GNSS-based approach, which leads to precise clock synchronization.

12

Comparison of singing voice quality from the beginning of the phonation and in the stable phase in the case of choral voices

Półrolniczak Edward, Kramarczyk Michał

Annals of Computer Science and Information Systems

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2019

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Vol. 18

349–-353

EN

In the process of acoustic voice analysis, in this case of singing, it is important that the sound samples contain a stable phase of phonation. Sometimes, however, it is not possible. This study was prepared to determine how big are the differences between the values of the acoustic parameters obtained for the initial phase of phonation and for the stable phase of phonation. The values of acoustic parameters, such as, among others shimmer, jitter, RAP, PPQ, APQ, HNR or SPR were estimated for registered singing samples in the initial phase of phonation and in the middle phase. The analysis were performed over the samples of singing of the vowel 'a' recorded many times for different pitches. In the process of analyzing of the obtained results, it was found that the impact of the selection phase of phonation for analysis is crucial in assessing the singing voice quality.

13

Opóźnienie transmisji danych w sieciach teleinformatycznych energetyki w świetle międzynarodowych norm i raportów technicznych IEC

Świderski J.

Wiadomości Elektrotechniczne

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2018

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R. 86, nr 4

12--16

PL

Opracowane przez IEC (International Electrotechnical Commission) normy i raporty techniczne dotyczące transmisji danych w sieciach teleinformatycznych energetyki specyfikują graniczne wartości opóźnienia transmisji odrębnie dla różnych strumieni danych. Jednakże wspomniane normy i raporty nie są w wymienionym zakresie jednolite, co może utrudniać ich praktyczne stosowanie, a także wywoływać kontrowersje w środowisku inżynierów odpowiedzialnych m.in. za funkcjonowanie systemów automatyki stacji elektroenergetycznych i tzw. produkcyjnych systemów dyspozytorskich energetyki.

EN

The standards and technical reports developed by the IEC (International Electrotechnical Commission) on data transmission in electric power data communication networks specify the transmission delay limits separately for different data streams. However, these standards and reports are not uniform in the above-mentioned scope, which may hinder their practical application, as well as cause controversy among engineers responsible for the operation of automation systems for power stations and the dispatching control systems.

14

Monitoring of phase jitter in fibre optic time and frequency transfer systems

Salwik K., Śliwczyński Ł., Krehlik P.

Metrology and Measurement Systems

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2018

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Vol. 25, nr 3

487--497

EN

The phase jitter enables to assess quality of signals transmitted in a bi-directional, long-distance fibre optic link dedicated for dissemination of the time and frequency signals. In the paper, we are considering measurements of jitter using a phase detector the detected frequency signal and the reference signal are supplied to. To cover the wideband jitter spectrum the detected signal frequency is divided and - because of the aliasing process - higher spectral components are shifted down. We are also examining the influence of a residual jitter that occurs in the reference signal generated by filtering the jitter occurring in the same signal, whose phase fluctuations we intend to measure. Then, we are discussing the evaluation results, which were obtained by using the target fibre optic time and frequency transfer system.

15

Evaluation of Selected Timing Parameters of FPGA Device

Sondej D., Szymanowski R., Szplet R.

Measurement Automation Monitoring

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2018

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Vol. 64, No. 1

23--25

EN

We present a method and results of measurements of FPGA (Field Programmable Gate Array) selected timing parameters crucial in many timing sensitive applications such as precise time and frequency metrology. Two main parameters, i.e. the delay and its jitter, were evaluated for look-up-tables (delay 740 ps/jitter 1.33 ps), IO buffers (na/0.45 ps) and carry-chain multiplexers (28ps/0.153 ps) integrated in a programmable device Spartan-6 (Xilinx) which is one of most popular FPGA chips on the market now. Measurements were performed with the use of fast real-time sampling oscilloscope.

16

The method of quality parameters measurement and evaluating of audio-video data transmission

Mazur D.

Studia Informatica

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2017

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Vol. 38, nr 3

57--72

EN

The paper describes the passive method of measuring the values of the data transmission quality parameters during audio-video calls performed in computer network. It also describes how the computer network can be evaluated in terms of providing an adequate level of service quality during audio-video data transmission. One can find in the paper the computer network testing procedure as well as results of measurements performed in a given test environment with the usage of described method. Presented method not only allows for computer network troubles diagnosis, but also for evaluation of newly build data quality transmission protocol’s mechanisms.

PL

W artykule opisano pasywną metodę eksperymentalnego wyznaczania wartości parametrów jakości transmisji danych podczas połączeń audio-wideo realizowanych w sieci komputerowej. Opisano również sposób oceny badanej sieci komputerowej pod względem zapewniania odpowiedniego poziomu jakości usług podczas transmisji danych audio-wideo. W artykule znajduje się również procedura testowania sieci komputerowej oraz wyniki badań przeprowadzonych w środowisku testowym przy wykorzystaniu opisywanej metody. Prezentowana metoda pozwala na diagnozę problemów sieci komputerowej, jak również na ocenę nowo budowanych mechanizmów w protokołach dla zapewnienia jakości danych.

17

Testing Time and Frequency Fiber-Optic Link Transfer by Hardware Emulation of Acoustic-Band Optical Noise

Lipiński M., Krehlik P., Śliwczyński Ł., Buczek Ł., Kołodziej J.

Metrology and Measurement Systems

|

2016

|

Vol. 23, nr 2

309--316

EN

The low-frequency optical-signal phase noise induced by mechanical vibration of the base occurs in field-deployed fibers. Typical telecommunication data transfer is insensitive to this type of noise but the phenomenon may influence links dedicated to precise Time and Frequency (T&F) fiber-optic transfer that exploit the idea of stabilization of phase or propagation delay of the link. To measure effectiveness of suppression of acoustic noise in such a link, a dedicated measurement setup is necessary. The setup should enable to introduce a low-frequency phase corruption to the optical signal in a controllable way. In the paper, a concept of a setup in which the mechanically induced acoustic-band optical signal phase corruption is described and its own features and measured parameters are presented. Next, the experimental measurement results of the T&F transfer TFTS-2 system’s immunity as a function of the fibre-optic length vs. the acoustic-band noise are presented. Then, the dependency of the system immunity on the location of a noise source along the link is also pointed out.

18

A low-jitter, full-differential PLL in 0.18μm CMOS technology

Modarresi F., Ghasemzadeh M., Mazlumi M., Amini A., Abolfathi T.

International Journal of Microelectronics and Computer Science

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2016

|

Vol. 7, nr 4

119--122

EN

This paper presents a Phase Locked Loop (PLL) which works with minimum jitter in the operation frequency range of 600MHZ to 900MHZ. Utilizing a full differential architecture that consists of several blocks of differential VCO, a differential PFD and a differential CPL leads to limiting the RMS jitter to 4.06ps, with 50mV power supply noise in the frequency range of 750MHz. Simulation results using 0.18μm CMOS TSMC standard technology demonstrate the power-consumption of 4.6mW at the supply voltage of 1.8V.

19

Metoda pomiaru parametrów jakości transmisji audio-wideo

Mazur D.

Przegląd Teleinformatyczny

|

2015

|

T. 3, Nr 1-2 (39)

41-64

PL

W artykule opisano pasywną metodę eksperymentalnego wyznaczania wartości parametrów jakości transmisji danych podczas połączeń audio–wideo realizowanych w sieci komputerowej. Opisano sposób oceny badanej sieci komputerowej pod względem zapewniania odpowiedniego poziomu jakości usług podczas transmisji danych audio-wideo. Przedstawiono również wyniki pomiarów wykonanych w środowisku platformy programowej Microsoft OCS (ang. Office Communications Server).

EN

The paper discusses a passive method of measuring values of data transmission quality parameters during audio-video calls performed in a computer network. It describes how the computer network can be evaluated in terms of providing an adequate level of service quality during audio-video data transmission. Results of measurements conducted in the system which includes the Microsoft OCS (Office Communications Server) platform are presented.

20

Practical application of cross correlation technique to measure jitter of master-oscillator-power-amplifier laser system

Młyńczak J., Sawicz-Kryniger K., Fry A. R., Glownia J. M., Leemans S.

Opto-Electronics Review

|

2014

|

Vol. 22, No. 4

218-223

EN

The Linac coherent light source (LCLS) at the SLAC National Accelerator Laboratory (SLAC) is the world’s first hard X-ray free electron laser (XFEL) and is capable of producing high-energy, femtosecond duration X-ray pulses. A common technique to study fast timescale physical phenomena, various “pump/probe” techniques are used. In these techniques there are two lasers, one optical and one X-ray, that work as a pump and as a probe to study dynamic processes in atoms and molecules. In order to resolve phenomena that occur on femtosecond timescales, it is imperative to have very precise timing between the optical lasers and X-rays (on the order of ~20 fs or better). The lasers are synchronized to the same RF source that drives the accelerator and produces the X-ray laser. However, elements in the lasers cause some drift and time jitter, thereby de-synchronizing the system. This paper considers cross-correlation technique as a way to quantify the drift and jitter caused by the regenerative amplifier of the ultrafast optical laser.