Wyniki wyszukiwania - BazTech

1

Synthesizing Non-Uniformly Excited Antenna Arrays Using Tiled Subarray Blocks

Mohammed Jafar Ramadhan

Journal of Telecommunications and Information Technology

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2023

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nr 4

25--29

EN

Conventionally, non-uniformly excited antenna arrays are synthesized by independently determining the excitation amplitude and phase of each single element. Such an approach is considered to be the most expensive and complex design method available. In this paper, the tilling technique is harnessed to synthesize non-uniformly excited antenna arrays. To apply this technique, the array elements are first divided into different subarray shapes, such as rectangles or squares known as tiles. The use of rectangular tile blocks instead of a single element architecture greatly simplifies the array design process and reduces array complexity. Next, the problem concerned with synthesizing sub-arrays comprising rectangular tile blocks is formulated and solved by using horizontal and vertical orientations of tiles having different shapes and sizes, and their larger integer expansions. The third approach to tiled design is a mixture of both previous tile architectures. A genetic algorithm is used to design such tiled arrays offering optimum sidelobe levels, beam width, directivity and taper efficiency. Simulation results demonstrated the effectiveness of the proposed tiled arrays.

2

Method of Compact Ground Launching Devices Shape Formation for Unmanned Aerial Vehicles

Sereda Vladyslav A., Ambrozhevich Maya V., Kornev Aleksey V.

Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa

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2022

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Vol. 13, Nr 1 (47)

9--26

EN

The purpose of this paper is to develop a method for forming the shape of compact ground launching devices (GLDs) unmanned aerial vehicles (UAVs), which includes three stages. Firstly, the choice on the basis of the theory of dimension and similarity of the closest analogue of the design object based on world experience gained in this field. Secondly, the creation of a comprehensive model of the working process of GLD and a universal method for its numerical implementation. Thirdly, the solution to the problem of optimizing the dynamic characteristics of GLD. At the described stages of the formation of the shape of an GLD UAV, a statistical analysis of the technical perfection of known analogues of UAV launch systems, methods of the theory of similarity and dimension in mechanics, methods of numerical simulation of the working process, and also methods of conditional parametric optimization are used. The undoubted importance of the problem of the equivalent development of the components of the UAS, consisting of an aircraft and a launch system (catapult). The traditionally non-priority status of GLD in the general cycle of the complex design program is also known. A systematic solution to this problem lies in the mainstream of creating common approaches, one of which is contained in this article. The proposed method of forming the appearance of compact GLDs UAV can be extended to a wide class of starting systems containing a thermal expansion machine and a mechanical component. In the presented form, the method is not applicable to systems of air, aerodrome and manual launch of UAVs. A method has been developed for the formation of the shape of GLD based on the energy relations of the criterion type between useful functions and the corresponding costs, with subsequent verification numerical studies of the launch processes based on specially created technology of a computational experiment, as well as optimization of the dynamic characteristics of GLD. The method of forming the shape of compact GLD is universally applicable to any type of catapults, regardless of the type of transmission and drive, since many particular forms of organization of the working process are generalized using the criteria of energy perfection, a comprehensive physical and mathematical model and normalization of the starting overload.

3

Performance Targeted Synthesis of ASM Controllers on FPGA

Salauyou V., Bulatowa I.

Measurement Automation Monitoring

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2018

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Vol. 64, No. 2

31--33

EN

Performance-driven synthesis of controller circuits is very important and challenging task in digital systems design. The clock frequency of a synchronous sequential logic circuit is dependent in a large part on the maximum propagation delay through its combinational block. The paper presents a new method for FPGA-based design of high-speed Algorithmic State Machine (ASM) controllers. The proposed approach is based on the introduction of additional states of the state machine in order to simplify transition and output logical functions to implement them in the single-level structures. The proposed technique is applied at the stage of converting the ASM chart to the finite state machine description and allows obtaining such an HDL specification that provides an increase in the designed system speed. Experimental results show that our approach achieves an average performance gain of 22.24% to 29.72% (for various FPGA devices) compared with the conventional synthesis method.

4

Analiza zużycia energii przez karty WLAN w trybie zmniejszonego poboru mocy

Natkaniec M., Janawa M., Szczęsny P.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

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2016

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nr 6

352--356, CD

PL

Artykuł przedstawia analizę zużycia energii przez karty WLAN pracujące w trybie zmniejszonego poboru mocy. W pracy analizowano i porównano zachowanie dwóch różnych kart WLAN, pracujących w trzech stanach: transmisji, odbioru i bezczynności. Szczegółowym badaniom poddany został również wpływ parametrów beacon_int oraz timeout na zużycie energii oraz wydajność pracy.

EN

The paper presents the energy consumption analysis of a WLAN cards in power saving mode. The behavior of two different WLAN cards was analyzed and compared for three states of operation: transmission, reception and idle. The influence of beacon_int and timeout parameters on power consumption and performance was also studied.

5

Lean Manufacturing – przepis na sukces

Lebitko T.

Napędy i Sterowanie

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2014

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R. 16, nr 11

30--32

PL

Od czasu, kiedy wydano słynną książkę The Machine That Changed the World Womacka i Jonesa, minęło 20 lat. W publikacji zaprezentowano wyniki kilkuletnich badań, dokumentujących przewagę modelu Lean nad modelem produkcji masowej. W przełomowych latach 90. ub.w. książka stała się objawieniem i wydawało się, że sukces filozofii Lean będzie szybki i spektakularny. Jednak ta metoda zarządzania wciąż nie jest powszechnie stosowana, chociaż efekty, które przynosi, robią wrażenie na największych światowych koncernach. Tym bardziej warto przyjrzeć się z bliska sposobom jej implementacji na przykładzie BorgWarner Cooling Systems – niemieckiej firmy z sektora automotive.

6

A new data mining approach for power performance verification of an on-shore wind farm

Castellani F., Garinei A., Terzi L., Astolfi D., Moretti M., Lombardi A.

Diagnostyka

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2013

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Vol. 14, No. 4

35--42

EN

Monitoring wind energy production is fundamental to improve the performances of a wind farm during the operational phase. In order to perform reliable operational analysis, data mining of all available information spreading out from turbine control systems is required. In this work a SCADA (Supervisory Control And Data Acquisition) data analysis was performed on a small wind farm and new post-processing methods are proposed for condition monitoring of the aerogenerators. Indicators are defined to detect the malfunctioning of a wind turbine and to select meaningful data to investigate the causes of the anomalous behaviour of a turbine. The operating state database is used to collect information about the proper power production of a wind turbine and a number map has been codified for converting the performance analysis problem into a purely numerical one. Statistical analysis on the number map clearly helps in detecting operational anomalies, providing diagnosis for their reasons. The most operationally stressed turbines are systematically detected through the proposal of two Malfunctioning Indices. Results demonstrate that a proper selection of the SCADA data can be very useful to measure the real performances of a wind farm and thus to define optimal repair/replacement and preventive maintenance policies that play a major role in case of energy production.

7

Porting the OPATM-BFM Application to a Grid e-Infrastructure – Optimization of Communication and I/O Patterns

Cheptsov A., Dichev K., Keller R., Lazzari P., Salon S.

Computational Methods in Science and Technology

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2009

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Vol. 15, nr 1

9-19

EN

OPATM-BFM is an off-line three-dimensional coupled eco-hydrodynamic simulation model used for biogeochemical and ecosystem-level predictions. This paper presents the first results of research activities devoted to the adaptation of the parallel OPATMBFM application for an efficient usage in modern Grid-based e-Infrastructures. For the application performance on standard Grid architectures providing generic clusters of workstations, such results are important. We propose a message-passing analysis technique for communication-intensive parallel applications based on a preliminary application run analysis. This technique was successfully used for the OPATM-BFM application and allowed us to identify several optimization proposals for the current realization of the communication pattern. As the suggested improvements are quite generic, they can be potentially useful for other parallel scientific applications.

8

Optimization of performance of queuing systems with long-tailed service times

Kubica B.J., Malinowski K.

Prace Naukowe Politechniki Warszawskiej. Elektronika

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2006

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z. 156

237-245

EN

This paper considers the problem of the performance optimization of a queuing system with long-tailed service time. Due to nonconvexity of the problem global optimization methods have to be used. Interval methods and genetic algorithms are considered. Approximation of the Laplace transform of the probability distribution function of the service time arises as a subproblem. A new method to do it is developed.

9

Efficient Programming and Optimization of Parallel Applications for Cluster Systems

Becker-Lemgau U.

Computational Methods in Science and Technology

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2006

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Vol. spec. issue

7-11

EN

Designing parallel applications and parallelizing sequential applications for cluster systems require powerful development tools to achieve scalable, reliable and highly efficient applications. The Intel Cluster Toolkit offers a toolset for development of MPI based applications and enables the developer to build, analyze, and optimize the parallel application. This article will describe the basic functionality and use of these tools.