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EN
This paper presents the results of comparison of vibration reduction levels between standard square based piezo actuators and piezoelectric sensor-actuator hybrids. Modelling was done using FEM method in ANSYS software. Model consisted of a steel plate with piezo elements attached. One of the elements was used as an actuator to excite plate’s vibrations. The other was either a standard homogeneous square based actuator or a sensor actuator hybrid with 2 possible sizes of the sensor part of said hybrid. Harmonic analyses were performed for the 1st, 2nd, 4th and 5th mode shapes with the goal function being the minimalization of displacement vector sum of a number of nodes (there were 3 possible cases). Significant vibration reduction levels were obtained with no significant differences in said levels between standard actuators and sensor-actuator hybrids. Reducing the size of sensor part of sensor-actuator allowed for lower voltages needed to achieve vibration reduction levels.
EN
This paper presents numerical analyses of the impact of the size of the sensor-actuator part on sensor-actuator efficiency. For that purpose, numerical models of a steel plate clamped on all sides were created with two piezoelectric actuators attached to it. One was used to excite the plate and the second (which could be either a standard actuator or a sensor-actuator, having different shapes and sensor part size) to reduce plates vibrations. Harmonic analyses were performed with the goal function being the minimum of the displacement vector sum of n nodes, where n can have different values depending on the case study.
EN
This paper deals with numerical analyses of plates vibration reduction effectiveness of an integrated disc based piezoelectric sensor-actuator compared to standard type disc based piezoelectric actuator. For that purpose 400 x 400 x 2 mm plate clamped on all sides was modelled with 2 piezo elements attached to it. One was a standard square based piezoelectric actuator used to excite the plate. The second one is disc based and can be either a standard element or an integrated sensor-actuator and is used for vibration reduction. The harmonic analyses were performed for the 1st, 2nd, 4th and 5th mode. Voltage used for plates excitation was always set to 100 V. The amplitude of voltage applied to the actuator was selected using internal ANSYS optimization procedures. The goal function for this was the minimum of the displacement vector sum of n nodes of the plate, with n having 3 possible values.
PL
Metody hybrydowej kompresji wizji zrewolucjonizowały sposób zapisu oraz transmisji cyfrowego obrazu. Coraz wydajniejsza reprezentacja obrazu torowała drogę do szerokiego wdrożenia multimedialnych systemów kolejnych generacji, jak cyfrowa telewizja, kino domowe czy telewizja w Internecie. Jednak możliwości te nie pojawiły się z dnia na dzień. Są one wynikiem wielu lat badań, ulepszeń już istniejących rozwiązań, ale również wdrażania nowych pomysłów. W artykule przedstawiono skalę tego postępu w ciągu ostatnich dwóch dekad. Poddano ocenie kolejne generacje koderów obrazu, od MPEG-2 do nowej techniki HEVC, zarówno pod względem samych osiągów kompresji, jak również innych cech techniki, których nie sposób pominąć realizując jej wdrożenie.
EN
Hybrid video compression has revolutionized the way of a video saving and transmission. More and more efficient representation of a video paved the way for the broad implementation of multimedia systems of successive generations, such as digital television, home cinema or television over the Internet. However, these opportunities did not appear from day to day. They are the result of many years of research, improvements of existing solutions, but also the implementation of new ideas. The paper presents the scale of this progress over the last 2 decades. It evaluates the successive generations of video encoders, from MPEG-2 to the new HEVC technology, both in terms of its compression efficiency, as well as other technical features that can not be omitted while putting the technology into the market.
EN
The paper presents Improved Adaptive Arithmetic Coding algorithm for application in future video compression technology. The proposed solution is based on the Context-based Adaptive Binary Arithmetic Coding (CABAC) technique and uses the authors mechanism of symbols probability estimation that exploits Context-Tree Weighting (CTW) technique. This paper proposes the version of the algorithm, that allows an arbitrary selection of depth D of context trees, when activating the algorithm in the framework of the AVC or HEVC video encoders. The algorithm has been tested in terms of coding efficiency of data and its computational complexity. Results showed, that depending on depth of context trees from 0.1% to 0.86% reduction of bitrate is achieved, when using the algorithm in the HEVC video encoder and 0.4% to 2.3% compression gain in the case of the AVC. The new solution increases complexity of entropy encoder itself, however, this does not cause an increase of the complexity of the whole video encoder.
EN
Intensive use of induction heating (IH) technology can be seen in many areas such as industrial, domestic and medical applications. The evolution of high-frequency switches has facilitated the design of high-frequency inverters, the key element of induction heating technology. Controling output power in a high-frequency inverter for induction heating application is complex. However, the importance of IH technology is not widespread. Induction heating technology requires accurate output power and current control with appropriate dynamics. Several power control techniques have been discussed inrelation to designing high-frequency inverters for IH applications. This paper makes a comprehensive review of the various power control techniques regarding high-frequency inverters for modern IH applications (domestic & industrial).
PL
Pokazano, jak dużą cześć całkowitego ruchu telekomunikacyjnego stanowi ruch związany z przesyłaniem obrazu ruchomego i przedstawiono skrótowy przegląd technik kompresji obrazu ruchomego. Na tym tle pokazano nową normę bardzo efektywnego kodowania wizyjnego (High Efficiency Video Coding - HEVC). Nową normę i związaną z nią technikę kompresji opisano z perspektywy wprowadzania nowych usług multimedialnych. W ostatniej cześoi artykułu omówiono pokrótce prace normalizacyjne związane z jednej strony z samą normą HEVC, a z drugiej strony - z jej planowanymi rozszerzeniami dotyczącymi kompresji obrazów stereoskopowych i trójwymiarowych.
EN
The considerations of the paper start with the discussion about the role of video transmission in the total telecommunication traffic. Then, a very brief overview is given for the international video compression standards. The above mentioned introductory considerations precede the introduction to the norm of HB/C (High Efficiency Video Coding). The new standard and the corresponding compression technology arę briefly described from the point of view of the new multimedia services. Therefore the last part of the paper contains a brief description of the HEVC-related standardization activities as well the description of the planned HD/C extensions for scalable and multwiew and 3-D video extensions.
PL
W artykule zaprezentowano oryginalną platformę przetwarzania rozproszonego wykorzystującą sieć NoC (Network-on-Chip) jako infrastrukturę komunikacyjną. Proponowaną platformę zrealizowano wykorzystując układy FPGA jako elementy na których zaprogramowano interesujące projektanta bloki obliczeniowe. Pokazano cechy takiego systemu oraz zalety przetwarzania rozproszonego realizowanego na wielu niezależnych fizycznie układach ASIC czy FPGA.
EN
The paper presents an original dissipated processing platform based on Network on Chip as communicative infrastructure. In the introduction the need for using dissipated processing to increase computational power of video compression systems is shown. Features of the dissipated processing system and advantages of its implementing in many physically independent FPGA or ASIC are shown. Several consecutive logical structures of the proposed system, differing in flexibility and implementation efforts, are given. In the third section a novel version of Network on Chip used as a communicative layer in the proposed platform is described. The hierarchic structure of this network and implemented communication modules are described. The proposed platform was built basing on Field Programmable Gate Array (FPGA) as elements on which computational blocks were programmed. Schematic diagram of the proposed system is shown in Fig. 1. The complete platform composed of nine boards with Field Programmable Gate Array (FPGA) is presented in Fig. 5.
PL
Omówiono rozwój nowych technik multimedialnych ze szczególnym uwzględnieniem najnowszej generacji metod kompresji obrazu i dźwięku. Te opanowane już technologicznie metody pozwalają istotnie zmniejszyć prędkość transmisji kosztem znacznego zwiększenia złożoności kodeków. W nowych systemach, w tym w systemach telewizyjnych tworzonych od początku, na przykład w nowych systemach cyfrowej telewizji naziemnej lub kablowej, zastosowanie technik kompresji czwartej.
EN
The paper deals with the development of new multimedia tech- niques, in particular, with the new generation of video and audio compression methods. These new methods are well developed and lead to considerable reductions of bitrate at the cost of a high increase of codec complexity. In new systems, in particular, in newly developed terrestrial and cable television systems, application of the techniques of fourth generation is a good alternative for obsolete MPEG-1/2 systems.
PL
Przedstawiono w skrócie bezdyskusyjnie dominującą w technice metodę kompresji cyfrowych sekwencji wizyjnych - metodę hybrydową. Omówiono aktualny stan techniki, a także najważniejsze cechy nowego standardu kompresji cyfrowych sekwencji wizyjnych - standardu H. 264/AVC. Zasygnalizowano prace badawcze dotyczące zastosowania technik falkowych w kompresji cyfrowych sekwencji wizyjnych.
EN
The paper briefly reports the absolutely dominated technique of digital video compression - the hybryd coding. Considered is state of technology and the most important features of the new video compression standard H. 264/avc. Mentioned is the research on wavelet-based techniques of digital video coding.
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