• 품질경영학회지
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• 제30권3호
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• pp.66-78
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• 2002

Process capability indices are being used as indicators for measurements of process capability for SPC of quality assurance system in industries. In view of the enhancement of customer satisfaction, process capability indices in which loss functions are used to deal with the economic loss In the processes deviated from the target, are in an adequate representation of the customer's perception of quality In this connection, the loss function has become increasingly important in quality assurance. Taguchi uses a modified form of the quadratic loss function to demonstrate the need to consider the proximity to the target while assessing its quality. But this traditional quadratic loss function is inadequate to assessing the quality and quality improvement since different processes have different sets of economic consequences on the manufacturing, Thereby, a flexible approach to the development of the loss function needs to be desired. In this paper, we introduce an easily understood loss function, based on reflection of probability density function of the normal distribution. That is, the Reflected Normal Loss function can be adapted to an asymmetric loss as well as to a symmetric loss around the target. We propose that, instead of the process variation, a new capability index, CpI using the Reflected Normal Loss Function that can accurately reflect the losses associated with the process and a new capability index CpI Is compared with the classical indices as $C_{p}$ , $C_{pk}$, $C_{pm}$ and $C_{pm}$ $^{+}$.>.+/./.

• 전기전자학회논문지
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• 제23권1호
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• pp.310-313
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• 2019

This paper used the majority function to digitally filter back-electromotive force as an explanation of the Brushless DC MOTOR control algorithm. The cause and improvement of motor noise, which are operating in close proximity to high frequency sources, did not use conventional low pass filter and comparator elements. Also, they repeatedly output a noise-free BEMF signal for the input value of the majority detection filtering. These filtering steps can help reduce costs and minimize the area of a PCB by requiring relatively little hardware.

• Architectural research
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• 제3권1호
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• pp.21-27
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• 2001

This study addressing the underlying strategies for Andong municipal museum complex development is in timely view that Andong has obtained a worldwide reputation as a treasury of traditional Korean Confucian culture. Thus far, there has been a tendency that various local museums are proposed to meet architectural aspirations architects and users commonly hold. Overall, though, the major role they play in making overall city image has not been considered in a systematic manner. Based on Lee's (2001) two previous studies, this study summarized the utility of cognitive distance and cognitive map concepts, which are proposed by Kevin Lunch (1976) to evaluate city image, in planning Andong municipal museum complex (AMMC). Sample is stratified into city residents and outsiders, and also into the general public and design-related professionals to see if there is any group difference in constructing their mental image. Three major findings are obtained. First, familiarity, so-called the degree of knowing, is the function of the length of stay in a designated area. That is, the longer people stay in Andong, the more likely they are familiar with its overall environmental aspects. Second, mental proximity of Andong municipal museum complex relative to existing cultural landmarks is closely related to the degree of how people value those landmarks in terms of their significance. Dosan Seowon and Hahoe folk village are most highly valued, which means higher proximity. Third, functional diversity turned out to be the most important design dimension, while display mechanism are least valued. Cognitive simulations of this sort are meaningful in that projected composite image might be a rough first approximation of true public image.

• 한국환경과학회지
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• 제13권10호
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• pp.939-946
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• 2004

The relationships between subjective symptoms of toluene exposed workers and concentration of their urinary excretion of hippuric acid were investigated. The exposed groups of 146 workers exposed to toluene and the control groups of 47 workers have never been exposed to toluene in Ulsan area were selected and studied. Hippuric acid was measured by HPLC, and counts of blood cells and liver function test were also performed. The mean value of urinary hippuric acid concentration of the control group was 0.322($\pm$0.267) g/L, while that of the exposed group was 1.260($\pm$0.395) g/L. As the concentration of hippuric acid had statistical proximity in $0.1\%$ level, WBC, GOT, and GPT didn't have any proximity(P>0.05). The exposed group showed lower level of leucocyte counts 6522.40(1710.3) than the control group 6891.50(1483.7). The exposed group showed higher level of GOT(25.75), GPT(27.09) than GOT(23.75), GPT(25.21) of the control group. Dried skin was the highest complained symptom of toluene exposed workers, the second strained eye, the third poor auditory function, and the fourth was headache.

• 산업경영시스템학회지
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• 제18권36호
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• pp.275-285
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• 1995

In recent years there has been increasing interest in the issue of process centering in manufacturing process, The traditional process capability indices Cp, Cpk and Cpu are used to provide measure of process performance, but these indices do not represent the issue of process centering. A new measure of the process capability index Cpm is proposed that takes into account the proximity to the target value as well as the process variation when assessing process performance. However, Cpm only considers acceptance cost for deviation from target value within specification limits, do not includes economic consideration for rejected items. This paper proposes flexible process performance measures that considered quadratic loss function caused by quality deviation within specification limits, rejection cost associated with the disposition of rejected items, and inspection cost. In this model disposition of rejected items are considered under perfect corrective procedures and the absence of perfect corrective procedures.

• East Asian mathematical journal
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• 제25권1호
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• pp.55-68
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• 2009

In this paper we propose new large-update primal-dual inte-rior point algorithms for $P_*(\kappa)$ linear complementarity problems(LCPs). New search directions and proximity measures are proposed based on the kernel function$\psi(t)=\frac{t^{p+1}-1}{p+1}+\frac{e^{\frac{1}{t}}-e}{e}$,$p{\in}$[0,1]. We showed that if a strictly feasible starting point is available, then the algorithm has $O((1+2\kappa)(logn)^{2}n^{\frac{1}{p+1}}log\frac{n}{\varepsilon}$ complexity bound.

• 한국산학기술학회논문지
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• 제16권8호
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• pp.5534-5540
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• 2015

철도 신호제어시스템에서 열차의 위치 및 점유 유무를 검지하기 위하여 궤도회로 이외에 axle counter적용 사례가 증가하고 있는 추세이다. 이에 본 연구에서는 열차검지 및 차축계수의 신뢰성을 높이기 위해 axle counter의 센서 방식을 지자기 센서 방식과 근접센서 방식을 비교하였으며, 그에 따른 차이점과 결과를 제시하였다. 또한, 정확한 차축검지를 위한 센서부의 취부조건 등을 고려한 설치에 대해 현장 경험을 기반으로 적용된 결과를 제시한다. 본 연구에서는 차축검지의 신뢰성 향상을 위해 센서의 위상차를 판단할 수 있도록 설계 변경한 결과 차축검지 기능뿐만 아니라 다양한 기능까지(열차의 방향검지, 열차속도검지 등) 수행할 수 있는 확장성을 확보하였다. 또한 열차의 종별, 무게 등의 특성에 종속되지 않았으며, 자체적으로 제작한 차축검지를 위한 모의차축 이송장치와 Test Bed를 구축하여 Lab. 테스트를 수행한 결과 350km/h의 속도에서도 차축 검지의 누락이 발생하지 않았음을 확인하였다. 이를 통해 열차의 검지뿐만 아니라 통과하는 열차의 속도와 편성 수, 선로전환기 통과 시 철사쇄정 조건 그리고 건널목 장치에도 적용할 수 있는 기반을 마련하였으며, 향후 철도 신호제어 시스템 전반에 확대 적용하게 되면 열차안전운행에 많은 기여를 할 것으로 판단된다.

• 한국정보과학회논문지:데이타베이스
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• 제36권3호
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• pp.198-214
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• 2009

RFID 태그의 시공간 이력정보는 리더에 의해 수집된 선분인 태그간격으로 모델링될 수 있으며, 태그 식별자(TID), 위치 식별자(LID), 시간(TIME)을 축으로 하는 3차원 도메인에서 색인될 수 있다. 도메인 공간에서 태그간격의 분포는 태그 위치추적 질의의 성능을 결정짓는 주요 요소이며 이는 각 도메인 좌표의 정렬에 따라 달라진다. 특히, 시간에 따라 변경되는 태그의 위치 이력을 검색하는 태그 위치추적 질의는 위치정보를 제공하는 LID가 도메인에서 정렬되는 순서에 따라 성능이 달라진다. 따라서, 색인에 저장된 태그간격의 검색 성능 향상을 위해서는 최적의 LID 순서를 결정하는 것이 필요하다. 이를 위하여 이 논문에서는 LID 간의 새로운 순서화 기준으로써 적용하기 위한 LID 근접성을 정의하고, 질의 시 함께 접근되는 태그간격을 색인에서 근접 저장하기 위한 LID 근접성 함수를 제안한다. 또한, 이를 기반으로 이미 부여된 LID의 재순서 기법을 제안한다. 성능 평가 결과 이 논문에서 제안한 LID 재순서 기법을 색인에 적용했을 때 기존의 LID 부여방식보다 월등한 질의 성능 향상을 보여주고 있다.

• 가정과삶의질연구
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• 제20권4호
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• pp.149-164
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• 2002

The purpose of this study was to identify the types of social networks of urban housewives according to different network composition patterns and to analyze the structural and functional characteristics of identified types. The data used in this study were collected from 589 full-time housewives residing in Taejeon city. The major findings are as follows: 1) The social networks of housewives in urban nuclear families were classified into eight types: the kin network, the non-kin network, the kin-centered network, the friend-centered network, the neighbor-centered network, the associate-centered network, the parallel network, and the decentralized network. 2) The structual characteristics (size, density, homogeneity, duration, proximity, frequency, closeness, direction) varied according to the type. The kin network type and the non-kin network type showed extreme degrees in network characteristics. The parallel network type and the decentralized network type showed an average level of network characteristics. The kin-, friend-, neighbor-, and the associate-centered types showed network characteristics of an intermediate level between the single-category types and the decentralized type. 3) The average levels of function of social network types were different in only two(service support, interference) of the six function areas(emotional support, service support, material support, information support, social companionship support, interference). The average level of service support by the non-kin network type was higher than other types. The average level of interference by the kin-centered network type was higher than other types, and that of the neighbor-centered network type was lower than other types. On the other hand, the total amount of function performance of social network types was different in all function areas. The total amount of social support given by the decentralized network type was greater than the other types. The total amount of interference given by the non-kin network type was smaller than the other types.

• 대한기계학회논문집 C: 기술과 교육
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• 제3권3호
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• pp.175-181
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• 2015

전투차량의 내부는 혹서기에는 약 $80^{\circ}C$에 이를 만큼 고온 다습한 환경에 노출되어 감지거리를 측정하여 제어기에 신호를 전달하는 근접센서가 감지거리가 늘어나면서 결국에는 센서 자체의 금속물질을 인식하여 작동이 안되는 고장이 다발하여 원인분석 및 개선을 수행하게 되었다. 개선은 2차에 걸쳐 수행되었고 많은 시행착오를 거쳐 고온에 장기적으로 노출될 경우 고장이 발생된다는 것을 알아내어 개선방안을 도출한 결과, 이미터코일(Emitter Coil)을 한 개 더 추가하여 전압차이를 높여 감지 정확도를 향상시키고, 내부 몰딩 면적을 높여 진동 및 충격 내성을 강화하여 온도 및 습도 변화에 둔감하도록 설계개선을 하였다. 입증을 위해 고온 다습($85^{\circ}C$, 85%습도)한 환경챔버에서 136시간 내구시험을 실시하여 고장 발생이 없음을 확인하였다.