• Journal of the Institute of Electronics Engineers of Korea TE
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• v.37 no.2
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• pp.33-40
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• 2000

In this study, a shape decomposition method using morphological operations is studied for decomposing the complex shape in 2-D image into its simple primitive elements. The serious drawback of conventional shape representation algorithm is that primitive elements are extracted too much to represent and to describe the shape. To solve these problems, a new shape decomposition algorithm using primitive elements that are similar to the geometrical characteristics of shape and 4 scan modes is proposed in this study. The multiple primitive elements as circle, square, and rhombus are extracted by using multiscan modes in a new algorithm. This algorithm have the characteristics that description error and number of primitive elements is reduced. Then, description efficiency is improved. The procedures is also simple and the processing time is reduced.

• Journal of Auto-vehicle Safety Association
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• v.12 no.1
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• pp.33-38
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• 2020

Since a diesel vehicle scandal related to the 'A' automobile company was issued in the United States in 2015, many countries have been interested in emission defeat devices. Being embedded in some diesel passenger cars sold in Korea, a defeat device for exhaust gas may have influence on both fuel economy and NOx emissions. In order to examine such effects, we carried out laboratory indoor tests as well as real road driving tests using four models of 'A' automobile company which may employ defeat devices. Those tests were performed observing the test modes of FTP-75, HWFET, and NEDC. Although fuel economy and NOx emissions according to indoor tests comply with the suggested tolerance, the findings in the real road driving tests do not satisfy the tolerance. Along with the results provided in this study, further evaluation may be necessary to investigate the noticeable difference between the indoor and real road tests.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.12C
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• pp.1039-1045
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• 2008

The H.264/AVC video coding standard shows extremely higher coding efficiency, but it causes high computational complexity. Especially, the intra mode decision using the rate-distortion method requires many computations. Thus, the efficient intra mode decision methods have been proposed by decreasing the encoding complexity. In this paper, we propose an efficient intra mode decision algorithm using $4{\times}4$ integer transform coefficients in the conversion of MPEG-2 to H.264 standard. It is shown that the proposed algorithm reduces encoding time and complexity compared to the conventional algorithm, while showing similar PSNR performance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.9A
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• pp.874-881
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• 2008

This paper presents an automatic frequency control algorithm for RTLS DS-SS modem based on the standard of ISO/IEC 24730-2. The presented automatic frequency control algorithm consists of frequency acquisition mode and frequency tracking mode, and the frequency acquisition mode is divided into the angle estimation step for frequency offset estimation and the verification step for removing the angle ambiguity. In the angle estimation step, three different sub-bit angles are estimated according to the timing intervals, then the estimates are used to re move the angle ambiguity in the verification step. The theoretical analysis and the simulation results of the proposed frequency control algorithm are presented.

• The Magazine of the IEIE
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• v.38 no.8
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• pp.33-39
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• 2011

HEVC(High Efficiency Video Coding)는 현재 국제 비디오 부호화 표준화 단체인 JCT-VC에서 표준화가 진행되고 있는 새로운 국제비디오 부호화 표준이다. 이 표준화에서는 H.264/AVC를 넘어선 높은 부호화 성능을 갖기 위해서 다양한 부호화 방법들이 논의되고 있다. 본고에서는 HEVC의 새로운 부호화 모드 중 화면 내 예측(intra prediction) 부호화 방법에 대해 소개한다. 화면 내 예측 부호화는 시간적으로 다른 영상을 참조하지 않고 오직 현재 부호화하려는 영상에서 공간적 주변 정보를 이용하여 현재 블록을 예측하는 방법이다. 이 화면 내 부호화 방법은 화면 간 예측(inter prediction) 부호화 방법과 함께 부호화 효율 향상에 기여할 뿐만 아니라, 임의 접근(random access)을 가능하게 하고 부호화 된 비트스트림의 에러 내성을 높인다. HEVC 화면 내 부호화 방법은 예측 모드의 종류를 최대 35개까지 확장함으로써 기존 비디오 부호화 표준에 비해 높은 부호화 효율을 갖는다.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.6 s.99
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• pp.652-659
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• 2005

In this paper, seismic qualification analysis for the Plant control Panel is carried out to confirm the structural integrity under the seismic conditions represented by required response spectra(RRS). The finite element method(FEM) is used for the analysis and a mode combination method is adopted to obtain a more reliable spectrum analysis results. In addition, the experimental analysis is performed to compare the reliability of the analytical results. The analysis results shows that the plant control panel system is designed to have the dynamic rigidity with no resonance frequency below 33 Hz. The analytically calculated maximum stress of the plant control panel system is $36\%$ of the field strength of material, thus it can be shown that the system has a stable structure for the seismic load.

• Journal of Industrial Technology
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• v.33 no.A
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• pp.9-14
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• 2013

Reliability plays a pivotal role in the development of medical instruments. A hyperbaric oxygen chamber, as a medical/health device, is known to help medical therapy for diversity of diseases through provision of high purity oxygen. The use of hyperbaric oxygen chamber is expected to increase in the future and study to examine reliability and safety is needed. We have performed reliability assessment for a newly developed hyperbaric oxygen chamber in this study. We first briefly discussed the system structure and mechanism. We then performed FMEA (Failure Mode and Effect Analysis) for the chamber. We drew major failure modes affecting the system performance and performed in depth analysis for measuring the expected effects.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.1
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• pp.33-39
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• 2003

Interior parts of a vehicle are getting important to reduce interior noise. Therefore, prior analysis of cabin noise related with interior parts are necessary at first design stage. Recently, Statistical Energy Analysis(SEA) has been suggested as a possible way for high frequency range noise analysis of interior parts. The validity of noise analysis with SEA to interior parts has been preyed by comparing with experimental result, and the developed method with SEA has been applied in finding optimized interior parts package.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.32-33
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• 2017

기존 EMI 필터 설계의 경우, 설계 가이드 없이 반복적인 측정을 통해 규제를 만족하도록 설계하기 때문에 많은 시간을 소모하게 된다. 또한 필터 내의 불필요한 소자 사용으로 인해 회로의 부피 및 가격 상승의 문제점이 있다. 따라서 본 논문은 대상 시스템에 대한 노이즈를 공통모드 노이즈(Common Mode Noise)와 차동모드 노이즈(Differential Mode Noise)로 분리하여 측정하였으며, 등가회로 모델링 및 제안 설계 가이드를 통해 최적 EMI 필터를 설계하였다. 또한 제안 EMI 필터 설계방법을 통해 설계 시간 단축, EMI 필터 단가 및 부피 저감이 가능하게 된다. 본 논문에서는 제안 방법을 이론으로 분석하고 모의실험을 통해 확인하였으며, 실제 측정을 통해 제안 방식의 우수성을 검증하였다.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.287-288
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• 2014

본 논문에서는 3레벨 4레그 컨버터에서 커먼 모드 전압(Common-mode Voltage, CMV)을 저감하기 위한 삼각파 비교 전압 변조 기법을 제안하였다. 제안한 PWM 방법은 매우 직관적이고, DSP 제어 시스템에서 쉽게 구현할 수 있다. SVPWM, SPWM의 스위칭 패턴 분석을 통하여 CMV 저감을 위한 4번째 레그(f상)의 극 전압 패턴을 제안하였고, 해당하는 f상 극 전압의 합성을 위하여, f상 양/음의 극 전압 지령 값을 계산하였다. 또한 a, b, c상 전압 왜곡을 막기 위한 옵셋 전압을 유도하였다. 제안한 PWM 방법의 유효성은 모의실험과 실험 결과를 통하여 검증되었다. 제안된 방법에서 CMV의 첨두치 및 스위칭 수는 SVPWM 방법에 비하여 각각 33%, 25%로 대폭 감소하였다.