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A study on engine performance of EGR valve problem in Hybrid vehicles (하이브리드 자동차의 EGR 밸브 오작동 시 엔진 성능에 미치는 영향)

  • Song, Rak Hyun;cho, Haeng Muk
    • Journal of Energy Engineering
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    • v.24 no.3
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    • pp.34-39
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    • 2015
  • Recently, Air pollution is gradually increasing which are coming from the exhaust of the ICE vehicles in the world. ICE vehicle exhaust gas and $CO_2$ are widely suspected of contributing to the called greenhouse effect, fueling fears of global warming. Therefore, many countries are striving to decrease the vehicle exhaust gas and have developed a variety of policies as air pollution regulation plans. To comply with the regulations, automotive industry has developed hybrid vehicles, which have features of both ICE vehicles and electric vehicles. Hybrid car is eco-friendly and has lowered exhausting gases and improved fuel efficiency. This research has been written to show that break down cases with EGR valve in hybrid cars, steadily increasing in use, and to help with on-site maintenance.

Research Analysis for Trouble Case of Power Capacitor (전력용 커패시터 사고 사례 조사 분석)

  • Kim, Jong-Gyeum;Park, Young-Jeen;Lee, Eun-Woong;Kim, Il-Joong;Cho, Seung-Su
    • Proceedings of the KIEE Conference
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    • 2008.04b
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    • pp.217-220
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    • 2008
  • 전력용 커패시터는 부하의 역률개선과 선로전류의 감소에 의한 변압기 용량의 여유와 선로의 리액턴스나 저항에 의한 전압강하가 감소로 전압이 안정되어 부하설비의 생산 능률과 제품의 품질 향상에 도움이 되기 때문에 송배전 회로망 또는 부하설비에 설치 운영되고 있다. 한편 부하의 변동에 따른 역률조정을 위한 스위칭 동작과 비선형 부하 등의 사용은 고조파 전류의 유입으로 전압 및 전류 스트레스를 증가시킬 수 있다. 커패시터는 낙뢰와 같이 일시적인 과전압에 의해 커패시터를 고장 나는 것도 있지만, 오랫동안의 스트레스로 고장이 나는 경우가 많아 커패시터가 고장 나는 정확한 원인분석을 체계적으로 한 보고서가 많지 않다. 본 연구에서는 국내외 일부 발표된 자료를 가지고서 커패시터가 전기품질 변동에 의해 고장이 일어날 수 있는 원인 등을 찾아 분석하였다.

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위암(胃癌)의 처방(處方) 운용(運用) 및 화학요법(化學療法) 병행(竝行) 치료(治療)에 관(關)한 소고(小考) (1990년(年) 이후(以後) 중의학(中醫學) 잡지(雜誌)를 중심(中心)으로)

  • Seo, Yeong-Cheol;Im, Seong-U;Lee, Won-Cheol
    • THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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    • v.3 no.1
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    • pp.193-206
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    • 1997
  • Stomach cancer is one of the most important cause of death. So recently, the first consideration Chinese Medicine Journal(after 1990th) to study on stomach cancer treatment(Herb medicine) and side effect on chemical therapy after side effect rate studied. According to the literally study of journal, the results run as follow. Herb medicine use in combination therapeutic method on stomach cancer decreased reaction.(G-I trouble, marrow and hematisis system) We expect that herb medicine treatment effects give to good advantage on stomach cancer.

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Design and Development of the Multi-joint Tracked Robot for Adaptive Uneven Terrain Driving (험지 주행을 위한 다관절 트랙 로봇 설계 및 개발)

  • Koh, Doo-Yeol;Kim, Soo-Hyun
    • The Journal of Korea Robotics Society
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    • v.4 no.4
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    • pp.265-272
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    • 2009
  • IVarious driving mechanisms to adapt to uneven environment have been developed for many urban search and rescue (USAR) missions. A tracked mechanism has been widely used to maintain the stability of robot's pose and to produce large traction force on uneven terrain in this research area. However, it has a drawback of low energy efficiency due to friction force when rotating. Moreover, single tracked mechanism can be in trouble when the body gets caught with high projections, so the track doesn't contact on the ground. A transformable tracked mechanism is proposed to solve these problems. The mechanism is designed with several articulations surrounded by tracks, used to generate an attack angle when the robot comes near obstacles. The stair climbing ability of proposed robot was analyzed since stairs are one of the most difficult obstacles in USAR mission. Stair climbing process is divided into four separate static analysis phases. Design parameters are optimized according to geometric limitations from the static analysis. The proposed mechanism was produced from optimized design parameters, and demonstrated in artificially constructed uneven environment and the actual stairway.

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Early Software Quality Prediction Using Support Vector Machine (Support Vector Machine을 이용한 초기 소프트웨어 품질 예측)

  • Hong, Euy-Seok
    • Journal of Information Technology Services
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    • v.10 no.2
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    • pp.235-245
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    • 2011
  • Early criticality prediction models that determine whether a design entity is fault-prone or not are becoming more and more important as software development projects are getting larger. Effective predictions can reduce the system development cost and improve software quality by identifying trouble-spots at early phases and proper allocation of effort and resources. Many prediction models have been proposed using statistical and machine learning methods. This paper builds a prediction model using Support Vector Machine(SVM) which is one of the most popular modern classification methods and compares its prediction performance with a well-known prediction model, BackPropagation neural network Model(BPM). SVM is known to generalize well even in high dimensional spaces under small training data conditions. In prediction performance evaluation experiments, dimensionality reduction techniques for data set are not used because the dimension of input data is too small. Experimental results show that the prediction performance of SVM model is slightly better than that of BPM and polynomial kernel function achieves better performance than other SVM kernel functions.

A Study on Harmonics Detection for Power Equipments (전력설비의 고조파진단에 관한 연구)

  • Lee, Buhm;Kim, Yong-Ha;Choi, Sang-Kyu;Kim, Jong-Kuk
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2000.10a
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    • pp.669-672
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    • 2000
  • This paper presents the methodology which analyze the effect of harmonics in power system. Considering the effect of less-harmonics, economic life and system loss, we have made the comprehensive countermeasure. According to the results of studying harmonics diagnosis and countermeasure, the following problems are pinpointed: protection of power system double investment space of the field. Therefore, in the initial stage, the countermeasure of harmonics trouble are set up. h a results, the following work has been done: $\circled1$ Generation source of harmonics and it's effect into en power system $\circled2$ Review of law related to harmonics, $\circled3$ Countermeasures to reduce the harmonics

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On-Line Defect Discrimination of Knitted Fabrics by the Narrow Band Eliminating Spatial Filtering Method -Analysis in Spatial Frequency Domain- (협대역 제거형 공간필터법에 의한 직물 결함의 온라인 종류판별 -공간주파수 영역에서의 해석-)

  • 전승환;김정률
    • Journal of the Korean Institute of Navigation
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    • v.20 no.1
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    • pp.81-85
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    • 1996
  • The defects occurred in knitted fabrics have several types due to some trouble sources. In particular, the defects caused by knitting machine troubles give a serious damage to the whole webs. It is, therefore, necessary to discriminate the kind of defects. The method to discriminate the type and size of defects has been proposed, which is used a pair of narrow band eliminating spatial filters. This method is based upon an isotropic signal processing in time domain. This paper is to confirm that the proposed method can be useful in the discrimination of defects, having analyzed in spatial frequency domain.

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Economic Analysis of the Receiver Pays Principle

  • Kim, Jeong-Yoo;Lim, Yoon-Sung
    • Proceedings of the Korea Technology Innovation Society Conference
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    • 1999.05a
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    • pp.117-149
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    • 1999
  • This paper is to examine the effect of the receiver pays principle (RPP) on the calling price, social welfare and interconnection charge. A significant trouble with introducing this system in telecommunications pricing is the possibility that the receiving party may refuse to receive a call if the charge he has to bear is very high. We find the condition for no calls to be refused and show that the profit maximizing prices charged to the calling party and the receiving party must satisfy this condition. We demonstrate that the calling price under RPP must be lower than the price under the caller pays principle (CPP), that the profit of a firm will be increased under RPP, but that the consumer surplus will not necessarily be increased under RPP despite the lowered calling price. Also, we show that, if the demand function is linear, the reciprocal interconnection charge under RPP is higher than that under CPP.

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The Evaluation of The Back Muscle's Tension for The Revision of The Sitting Posture (앉은 자세 보정을 위한 등근육 긴장도 평가)

  • 유종현;홍성찬;백승은;백승화
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.53 no.4
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    • pp.300-308
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    • 2004
  • Nowadays, many people have a lot of time on chair in their life. If the sitting posture is not correct, there is some trouble with the waist. And if the sitting posture goes on long time at a slant, it sometimes causes the hurts of waist or the deformded spinal column. A crouched posture is an obstacle to breath and it give rise to drowsiness because of the lack of oxygen. The sitting posture is a habit so that people can't feel it oneself and look over some kind of risks. The evaluation of the sitting posture is analyzed by measuring EMG of spinal both side of spinal-bones. In this paper, we can evaluate a right the sitting posture by analyzing the increase of the tention of muscle in one or the other side of muscles when the posture inclines one side and describes the usefulness of the signal of EMG to evaluate the influence of the sitting posture on waist.

Noisy Parameter Estimation of Noisy Passive Telemetry Sensor System using Unscented Kalman Filter (잡음환경에서 UKF를 이용한 원격센서시스템의 파라메타 추정)

  • Kim, Kyung-Yup;Yu, Dong-Gook;Choi, Woo-Jin;Lee, Kwan-Tae;Lee, Joon-Tark
    • Proceedings of the KIEE Conference
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    • 2006.07d
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    • pp.1787-1788
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    • 2006
  • In this paper, a noisy passive telemetry sensor system using Unscented Kalman Filter (UKF) is proposed. To overcome these trouble problems such as a power limitation and a estimation complexity that the general passive telemetry sensor system including IC chip has, the principle of inductive coupling was applied to the modelling of a passive telemetry sensor system (PTSS) and its noisy capacitive parameter was estimated by the UKF algorithm. Specialty, to show the effective tracking performance of the UKF, we compared with the tracking performance of Recursive Least Square Estimation (RLSE) using linearization

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