• KIEE International Transactions on Power Engineering
• /
• 제2A권3호
• /
• pp.95-101
• /
• 2002

This paper illustrates a new fuzzy effective load model for probabilistic and fuzzy production cost simulation of the load point of the composite power system. A model for reliability evaluation of a transmission system using the fuzzy set theory is proposed for considering the flexibility or ambiguity of capacity limitation and overload of transmission lines, which are subjective matter characteristics. A conventional probabilistic approach was also used to model the uncertainties related to the objective matters for forced outage rates of generators and transmission lines in the new model. The methodology is formulated in order to consider the flexibility or ambiguity of load forecasting as well as capacity limitation and overload of transmission lines. It is expected that the Fuzzy CMELDC (CoMposite power system Effective Load Duration Curve) proposed in this study will provide some solutions to many problems based on nodal and decentralized operation and control of an electric power systems in a competitive environment in the future. The characteristics of this new model are illustrated by some case studies of a very simple test system.

• Clinical and Experimental Pediatrics
• /
• 제55권1호
• /
• pp.24-28
• /
• 2012

Partial anomalous pulmonary vein connection (PAPVC) is a rare congenital abnormal cardiac defect involving the pulmonary veins draining into the right atrium (RA) directly or indirectly by venous connection. Ninety percent of PAPVCs are accompanied by atrial septal defect (ASD). To our knowledge, there is no previous report of PAPVC with ventricular septal defect (VSD) without ASD in Korea, and in this paper, we report the first such case. A 2-day-old girl was admitted into the Chonnam National University Hospital for evaluation of a cardiac murmur. An echocardiogram revealed perimembranous VSD without ASD. She underwent patch closure of the VSD at 5 months of age. Although the VSD was completely closed, she had persistent cardiomegaly with right ventricular volume overload, as revealed by echocardiography. Three years later, cardiac catheterization and chest computed tomography revealed a PAPVC, with the right upper pulmonary vein draining into the right SVC. Therefore, correction of the PAPVC was surgically performed at 3 years of age. We conclude that it is important to suspect PAPVC in patients with right ventricular volume overload, but without ASD.

• Journal of Oral Medicine and Pain
• /
• 제46권3호
• /
• pp.69-74
• /
• 2021

As for temporomandibular joint arthritis (TMJ OA), managing the contributing factors at an early stage through accurate diagnosis is necessary to prevent irreversible bone changes. TMJ OA, which is a multi-organ disease caused by various pathophysiological mechanisms, is developed mainly due to mechanical overload. It is a disease characterized by degeneration of articular cartilage and subchondral bone as a low-level inflammatory arthritis condition developed by dysregulation of catabolic and anabolic activity of chondrocytes. Age, mechanical overload sensing of cartilage, chondrocyte apoptosis, catabolic enzymes, inflammatory factors, abnormal remodeling of subchondral bone, and estrogens may be involved in the pathogenesis of arthritis. Therefore, a comprehensive evaluation is needed to diagnose and manage progressive cartilage degeneration, subchondral bone remodeling, and associated symptoms of TMJ OA.

• Fisheries and Aquatic Sciences
• /
• 제19권4호
• /
• pp.21.1-21.11
• /
• 2016

Background: The evaluation of suitable reference genes as normalization controls is a prerequisite requirement for launching quantitative reverse transcription-PCR (RT-qPCR)-based expression study. In order to select the stable reference genes in abalone Haliotis discus hannai tissues (gill and hepatopancreas) under heavy metal exposure conditions (Cu, Zn, and Cd), 12 potential candidate housekeeping genes were subjected to expression stability based on the comprehensive ranking while integrating four different statistical algorithms (geNorm, NormFinder, BestKeeper, and ${\Delta}CT$ method). Results: Expression stability in the gill subset was determined as RPL7 > RPL8 > ACTB > RPL3 > PPIB > RPL7A > EF1A > RPL4 > GAPDH > RPL5 > UBE2 > B-TU. On the other hand, the ranking in the subset for hepatopancreas was RPL7 > RPL3 > RPL8 > ACTB > RPL4 > EF1A > RPL5 > RPL7A > B-TU > UBE2 > PPIB > GAPDH. The pairwise variation assessed by the geNorm program indicates that two reference genes could be sufficient for accurate normalization in both gill and hepatopancreas subsets. Overall, both gill and hepatopancreas subsets recommended ribosomal protein genes (particularly RPL7) as stable references, whereas traditional housekeepers such as ${\beta}-tubulin$ (B-TU) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes were ranked as unstable genes. The validation of reference gene selection was confirmed with the quantitative assay of MT transcripts. Conclusions: The present analysis showed the importance of validating reference genes with multiple algorithmic approaches to select genes that are truly stable. Our results indicate that expression stability of a given reference gene could not always have consensus across tissue types. The data from this study could be a good guide for the future design of RT-qPCR studies with respect to metal regulation/detoxification and other related physiologies in this abalone species.

• 한국신뢰성학회지:신뢰성응용연구
• /
• 제14권4호
• /
• pp.236-242
• /
• 2014

Since permanent magnet coupling transfers power by magnetic force without contact, it has little shock, vibration, noise. In case of overload, it protects a pump or a motor which is relatively important by slipping internally. In this study, failure analysis and test evaluation on the permanent magnet coupling have been proposed and the process that reliability of the product improves through design improvement has been presented. And failure cause of typical failure case has been investigated and improvement plan has been presented. Finally, reliability improvement is established by analysis of the test results of before and after acceleration test.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1993년도 정기총회 및 추계학술대회 논문집 학회본부
• /
• pp.59-62
• /
• 1993

The evaluation of the temperature of the motor in operation is necessary for smaller and lighter design of motors and for the determination of insulation class. And the evaluation of the temperature in thermal transient state is necessary for the determination of the intermittent rating and the protection from the thermal overload. The temperature can be calculated exactly by considering the loss distribution, the thermal resistances and the thermal capacities dependent on temperature. Using the detailed thermal equivalent circuit, the temperature of any local part of the motor can be evaluated. The comparison between the calculated results and the experiments is performed to verify the validity of the analysis.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2001년도 춘계학술대회논문집D
• /
• pp.903-908
• /
• 2001

A web-based client/server program, MOVIDIK(Motor-Operated-Valve Integrated Database Information of KEPCO) has been developed to perform a design basis safety evaluation for a motor-operated-valve(MOV) in the nuclear power plant. The MOVIDIK consists of seven analysis modules and one administrative module. The analysis module calculates a differential pressure on the valve disk, thrust/torque acting at a valve stem, maximum allowable stress, thermal-overload-relay selection, voltage degradation, actuator output and margin. In addition, the administrative module manages user information, approval system and code information. MOVIDIK controls a huge amount of evaluation data and piles up the safety information of safety-related MOV. The MOVIDIK will improve the efficiency of safety evaluation work and standardize the analysis process for the MOV.

• 디지털콘텐츠학회 논문지
• /
• 제10권3호
• /
• pp.395-400
• /
• 2009

인터넷 서비스가 광범위하게 제공되면서 혁신적으로 웹 GIS가 발달하게 되었다. 그러나 현실적으로 인터넷 지리 정보 시스템에서는 대용량의 공간 데이터의 전송에 따른 사용자 응답 시간 지연, 네트워크의 트래픽, 그리고 서버 과부하 문제가 발생한다. 본 논문에서는 이와 같은 문제를 해결하기 위하여 클라이언트 측의 캐시 알고리즘을 제안하고자 한다. 제안된 알고리즘은 단위 시간과 공간 근접성의 개념을 이용하여 기존의 연구를 개선한다. 그리고 효율성의 향상 정도를 측정하기 위해 성능 평가를 실시하고 결과를 분석한다. 성능 평가 결과, 공간 데이터의 질의 시에 기존의 알고리즘에 비하여 적중률에 있어서 보다 좋은 성능을 나타내었다.

• 디자인학연구
• /
• 제17권1호
• /
• pp.253-264
• /
• 2004

본 연구의 최종 목표는 모바일 인터넷 서비스의 사용편의성을 높이는 데 있어 그래픽디자인 평가 방법론을 개발하고, 인터페이스 디자인에서의 사용자 니즈(needs)를 예측할 수 있는 측정모델을 개발하며, 평가기반을 시스템화 하는데 있다. 이를 위해 GUI 디자인 평가 방법론의 핵심 내용을 시스템화하여 프로토타입(Prototype) 설계 및 평가과정을 직접 지원하는 UI 설계지원 시스템으로 구현하였다. Small Screen이라는 제한된 display 환경에서는 사용자가 인지의 과부하 없이 단시간에 임무를 완성하도록 조작정보의 흐름을 즉각적이고 함축적인 방법으로 알려줄 수 있는 사용자 중심의 시각언어-이미지를 이용하여야 하며, 또한 UI 설계에 반영함에 있어서는 객관성을 높여야만 한다. 이에 모바일 인터넷의 사용편의성을 체계적으로 평가할 수 있는 디자인 평가 방법론은 매우 중요하며, 특히 사용자의 디자인 니즈 및 트렌드(Trend)를 예측할 수 있는 그래픽디자인 평가모델은 사용자의 감성적인 측면을 인터페이스 디자인에 반영할 수 있다는 특성으로 해서 그 의의가 매우 크다고 할 것이다. 이러한 디자인 평가라는 결과를 토대로 모바일 인터넷 표준 GUI가 설계되었으며, 차후 유비쿼터스(Ubiquitous) 환경의 GUI 개발에도 활용이 될 수 있는 기초가 되었으면 한다.

• 인터넷정보학회논문지
• /
• 제1권1호
• /
• pp.27-34
• /
• 2000

최근 지리 정보 시스템은 인터넷의 발전과 더불어 사회의 각 분야에서 그 활용성이 증가하고 있다. 그러나, 현실적으로 인터넷 지리 정보 시스템에서는 대용량의 공간 데이터ㅢ 전송에 따른 사용자 응답 시간 지연, 네트워크의 트래픽, 그리고 서버 과부하 문제가 발생한다. 본 논문에서는 이와 같은 문제를 해결하기 위하여 클라이언트 측의 캐쉬 알고리즘을 제안하고자 한다. 제안된 알고리즘은 단위 시간과 공간 근접성의 개념을 이용하여 기존의 연구를 개선한다. 그리고, 효율성의 향상 정도를 측정하기 위해 성능 평가를 실시하고 결과를 분석한다. 성능 평가 결과, 공간 데이터의 질의 시에 기존의 알고리즘에 비하여 적중율에 있어서 보다 좋은 성능을 나타내었다.