• Title/Summary/Keyword: Electronics Units

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천리안위성의 발사체와의 전자파 적합성 시험결과 분석 (RF Compatibility Test Results of COMS satellite with Launch Vehicle)

  • 최재동
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2010년도 추계학술대회
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    • pp.215-217
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    • 2010
  • This paper describes the test results of radiated compatibility with Ariane 5 launcher performed on the COMS Satellite test facility. Firstly, the Radiated Emission test results are analyzed in compliance with the Radiated Susceptibility requirement specification of Ariane 5 launcher. The satellite nominal operation is monitored during injection a radiated electric field corresponding to the launcher emissions levels in critical frequency ranges. And also, E-field are measured through a probe located at external units level in order to assess the EMC safety margin in Radiated mode.

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Two-Step Rate Distortion Optimization Algorithm for High Efficiency Video Coding

  • Goswami, Kalyan;Lee, Dae Yeol;Kim, Jongho;Jeong, Seyoon;Kim, Hui Yong;Kim, Byung-Gyu
    • Journal of Multimedia Information System
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    • 제4권4호
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    • pp.311-316
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    • 2017
  • High Efficiency Video Coding (HEVC) is the newest video coding standard for improvement in video data compression. This new standard provides a significant improvement in picture quality, especially for high-resolution videos. A quadtree-based structure is created for the encoding and decoding processes and the rate-distortion (RD) cost is calculated for all possible dimensions of coding units in the quadtree. To get the best combination of the block an optimization process is performed in the encoder, called rate distortion optimization (RDO). In this work we are proposing a novel approach to enhance the overall RDO process of HEVC encoder. The proposed algorithm is performed in two steps. In the first step, like HEVC, it performs general rate distortion optimization. The second step is an extra checking where a SSIM based cost is evaluated. Moreover, a fast SSIM (FSSIM) calculation technique is also proposed in this paper.

통합변압기 적용 넓은 출력전압제어 LED 전원공급장치 (An Integrated Transformer-based LED Power Supply with Wide-Output-Voltage Control)

  • 강철하;주종성;김은수;원종섭;이영수;김동희
    • 전력전자학회논문지
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    • 제20권5호
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    • pp.437-447
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    • 2015
  • In this paper, implementation of an integrated transformer applicable to power supply units (PSUs) for a 150-W LED with a wide range of output voltage is presented. The transformer is comprised of a PFC inductor and an LLC resonant transformer, each of which is placed and integrated on an E-I-E-type magnetic core. Integrated transformers with two different air gap topologies (i.e., the side and center gap topologies) are considered in the design phase to investigate their applicability. The design consideration on the LLC resonant converter used for the wide-output-voltage control ranges is described, and the overall performance of the proposed system is verified through realization of it onto a 150-W LED PSU board.

A Gyro-Free INS Algorithm in the Navigation Frame and Its Application to the Spinning Vehicle with High Rotation Rate

  • Lee, Junhak;Kim, Heyone;Oh, Sang Heon;Do, Jae Chul;Nam, Chang Woo;Hwang, Dong-Hwan;Lee, Sang Jeong
    • Journal of Positioning, Navigation, and Timing
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    • 제7권2호
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    • pp.91-103
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    • 2018
  • Conventional inertial measurement units cannot be used in the spinning vehicle with high rotation rate due to gyro's narrow operation range. By the way, angular acceleration can be measured using the accelerometer array distributed in the vehicle. This paper derives a mechanization for the gyro-free INS in the navigation frame, and proposes a gyro-free INS algorithm based on the derived mechanization. In addition, the proposed algorithm is used to estimate angular velocity, attitude, velocity, and position of a spinning vehicle with high rotation rate. A MATLAB-based software platform is configured in order to show validation of the proposed algorithm. The reference trajectory of a spinning vehicle at 3 round per second, 30 round per second are set up, and the outputs of accelerometer are generated when triads of accelerometer are located at the origin and all the axes. Navigation results of the proposed algorithm for the generated output are presented. The results show that the proposed navigation algorithm can be applied to the spinning vehicle with high rotation rate.

Control strategies of energy storage limiting intermittent output of solar power generation: Planning and evaluation for participation in electricity market

  • Sewan Heo;Jinsoo Han;Wan-Ki Park
    • ETRI Journal
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    • 제45권4호
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    • pp.636-649
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    • 2023
  • Renewable energy generation cannot be consistently predicted or controlled. Therefore, it is currently not widely used in the electricity market, which requires dependable production. In this study, reliability- and variance-based controls of energy storage strategies are proposed to utilize renewable energy as a steady contributor to the electricity market. For reliability-based control, photovoltaic (PV) generation is assumed to be registered in the power generation plan. PV generation yields a reliable output using energy storage units to compensate for PV prediction errors. We also propose a runtime state-ofcharge management method for sustainable operations. With variance-based controls, changes in rapid power generation are limited through ramp rate control. This study introduces new reliability and variance indices as indicators for evaluating these strategies. The reliability index quantifies the degree to which the actual generation realizes the plan, and the variance index quantifies the degree of power change. The two strategies are verified based on simulations and experiments. The reliability index improved by 3.1 times on average over 21 days at a real power plant.

학습 기능을 내장한 신경 회로망의 하드웨어 구현 (Implementation of artificial neural network with on-chip learning circuitry)

  • 최명렬
    • 전자공학회논문지B
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    • 제33B권3호
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    • pp.186-192
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    • 1996
  • A modified learning rule is introduced for the implementation of feedforward artificial neural networks with on-chip learning circuitry using standard analog CMOS technology. Learning rule, is modified form the EBP (error back propagation) rule which is one of the well-known learning rules for the feedforward rtificial neural nets(FANNs). The employed MEBP ( modified EBP) rule is well - suited for the hardware implementation of FANNs with on-chip learning rule. As a ynapse circuit, a four-quadrant vector-product linear multiplier is employed, whose input/output signals are given with voltage units. Two $2{\times}2{\times}1$ FANNs are implemented with the learning circuitry. The implemented FANN circuits have been simulatied with learning test patterns using the PSPICE circuit simulator and their results show correct learning functions.

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CCD에 의한 GF($p^m$)상의 다치 승산기 구성에 관한 연구 (A Study on Construction of Multiple-Valued Multiplier over GF($p^m$) using CCD)

  • 황종학;성현경;김흥수
    • 전자공학회논문지B
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    • 제31B권3호
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    • pp.60-68
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    • 1994
  • In this paper, the multiplicative algorithm of two polynomials over finite field GF(($p^{m}$) is presented. Using the presented algorithm, the multiple-valued multiplier of the serial input-output modular structure by CCD is constructed. This multiple-valued multiplier on CCD is consisted of three operation units: the multiplicative operation unit, the modular operation unit, and the primitive irreducible polynomial operation unit. The multiplicative operation unit and the primitive irreducible operation unit are composed of the overflow gate, the inhibit gate and mod(p) adder on CCD. The modular operation unit is constructed by two mod(p) adders which are composed of the addition gate, overflow gate and the inhibit gate on CCD. The multiple-valued multiplier on CCD presented here, is simple and regular for wire routing and possesses the property of modularity. Also. it is expansible for the multiplication of two elements on finite field increasing the degree mand suitable for VLSI implementation.

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High-Performance Korean Morphological Analyzer Using the MapReduce Framework on the GPU

  • Cho, Shi-Won;Lee, Dong-Wook
    • Journal of Electrical Engineering and Technology
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    • 제6권4호
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    • pp.573-579
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    • 2011
  • To meet the scalability and performance requirements of data analyses, which often involve voluminous data, efficient parallel or concurrent algorithms and frameworks are essential. We present a high-performance Korean morphological analyzer which employs the MapReduce framework on the graphics processing unit (GPU). MapReduce is a programming framework introduced by Google to aid the development of web search applications on a large number of central processing units (CPUs). GPUs are designed as a special-purpose co-processor. Their programming interfaces are typically formulated for graphics applications. Compared to CPUs, GPUs have greater computation power and memory bandwidth; however, GPUs are more difficult to program because of the design of their architectures. The performance of the Korean morphological analyzer using the MapReduce framework on the GPU is evaluated in comparison with the CPU-based model. The proposed Korean Morphological analyzer shows promising scalable performance on distributed computing with the GPU.

두 개의 송신코일을 갖는 위상 천이 자기 공진 무선 전력 전송 시스템 (Phase Shifted Magnetic Resonance Wireless Power Transfer System with Two Transmit Coils)

  • 정재엽;이강현
    • 전력전자학회논문지
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    • 제23권4호
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    • pp.290-293
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    • 2018
  • This paper proposes a new magnetic resonant wireless power transfer system. Two transmitters are arranged to secure a range wider than the existing one-to-one resonance, thereby enhancing the practicality of the system. Two identical transmission units are arranged to strengthen the magnetic field and to subsequently increase the magnitude and distance of the power transmitted to the reception unit. A constant power can be maintained in a wide range through the phase control of different output powers according to the positions of the transmitting and receiving coils. A constant power can also be obtained by transmitting to the receiver. The experiment results show that the proposed method outperforms the conventional method.

ISO 26262 automotive functional safety: issues and challenges

  • Ismail, Azianti;Liu, Qiang
    • International Journal of Reliability and Applications
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    • 제15권2호
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    • pp.151-161
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    • 2014
  • Recently, the automotive industry has been introduced to ISO 26262 in November 2011 to address the necessity of safety risk from sensor to actuator by providing guidance in the form of requirements and processes. The malfunctioning behaviour of these systems could have significant impact on the safety of humans and/or the environment. Most of the modern automobiles are equipped with embedded electronic systems which include lots of Electronic Controller Units (ECUs), electronic sensors, signals, bus systems and coding. Due to the complex application in electrical, electronics and programmable electronics, the need to carry out detailed safety analyses which focuses on the potential risk of malfunction is crucial for automotive systems. In this paper, the international trends on pre and post introduction of ISO 26262 through publications will be analyzed as well as to take a glimpse in the activities for implementing this standard by the automotive manufacturers. The issues and challenges which have been occurring from implementing this standard also will be highlighted.

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