• 응용통계연구
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• 제33권2호
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• pp.161-170
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• 2020

${\bar{X}}-S^2$ 관리도는 공정 평균과 산포의 변화를 동시에 탐지하는 전통적인 관리도들 중 하나이다. 일반적으로 사용하는 ${\bar{X}}-S^2$ 관리도의 설계 방법은 병행하는 관리도의 오경보율은 주어진 값을 만족하면서 각 관리도는 동일한 개별적인 오경보율을 갖도록 설정하는 것이다. 이 논문에서는 각 관리도의 개별 오경보율을 다르게 설정하고 이것이 ${\bar{X}}-S^2$ 관리도의 성능에 어떠한 영향을 주는지 살펴보았다. 이를 위해 ${\bar{X}}$ 관리도의 오경보율을 S² 관리도의 오경보율에 γ배한 경우를 고려하였고, γ값에 따른 ${\bar{X}}-S^2$ 관리도 성능을 비교하였다. 관리도의 성능을 평가하는 측도로는 특정한 변화에 대한 성능을 판단하는 경우 이상상태에서의 평균런길이를 사용하였고, 전반적인 성능을 판단하는 경우 RMI(relative mean index)를 사용하였다.

• 한국정보시스템학회지:정보시스템연구
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• 제26권2호
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• pp.43-62
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• 2017

Purpose This study provided empirical support for the model that explain the formation of privacy concerns in the perspective of Information Boundary Theory. This study investigated an integrated model suggesting that privacy concerns are formed by the individual's disposition to value privacy, privacy awareness, awareness of privacy policy, and government legislation. The Information Boundary Theory suggests that the boundaries of information space dependends on the individual's personal characteristics and environmental factors of e-commerce. When receiving a request for personal information from e-commerce websites, an individual assesses the risk depending on the risk-control assessment, the perception of intrusion give rise to privacy concerns. Design/methodology/approach This study empirically tested the hypotheses with the data collected in a survey that included the items measuring the constructs in the model. The survey was aimed at university students. and a causal modeling statistical technique(PLS) is used for data analysis in this research. Findings The results of the survey indicated significant relationships among environmental factors of e-commerce websites, individual's personal privacy characteristics and privacy concerns. Both individual's awareness of institutional privacy assurance on e-commerce and the privacy characteristics affect the risk-control assessment towards information disclosure, which becomes an essential components of privacy concerns.

• Journal of Electrical Engineering and Technology
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• 제13권1호
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• pp.240-249
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• 2018

Individual DC voltage balance problem is an inherent issue for cascaded H-bridge (CHB) based converter. When the CHB-based static synchronous compensator (STATCOM) is operating at zero current mode, the software-based individual DC voltage balancing control techniques may not work because of the infinitesimal output current. However, the different power losses of each cell would lead to the individual DC voltages unbalance. The uneven power losses on the local supplied cell-controllers (including the control circuit and drive circuit) would especially cause the divergence of individual DC voltages, due to their characteristic as constant power loads. To solve this problem, this paper proposes an adaptive voltage balancing module which is designed in the cell-controller board with small size and low cost circuits. It is controlled to make the power loss of the cell a constant resistance load, thus the DC voltages are balanced in zero current mode. Field test in a 10kV STATCOM confirms the performance of the proposed method.

• 대한기계학회논문집A
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• 제38권1호
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• pp.1-9
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• 2014

로터에 작용하는 불균형한 반복 하중은 풍력발전기에 구조적 하중을 발생시키고 이러한 하중이 구조물에 지속적으로 누적되면 피로 파괴와 수명 단축을 발생시킨다. Individual pitch control(IPC)는 이러한 구조적 하중을 저감시키고 풍력발전기의 작동 수명 연장에 효과가 있는 제어 방법이다. 본 연구에서는 Decentralized LQR(DLQR)과 Disturbance accommodating control(DAC)를 이용한 IPC 설계를 제시한다. DLQR은 로터 회전속도 제어를 위해 사용하였고 DAC는 블레이드에 외란으로 작용하는 바람(난류) 효과를 상쇄하도록 구성하였다. 제시된 IPC제어기의 구조적 하중 저감 효과는 Gain-scheduled PI로 설계된 Collective pitch control(CPC)과 비교하여 확인하였다. 또한, IPC의 구조물 하중 저감 효과를 확인하기 위해 피로 누적에 의한 손상정도를 나타내는 피로등가하중(DEL)을 이용하였다.

• 대한가정학회지
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• 제44권12호
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• pp.53-64
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• 2006

The purpose of this study was to investigate the variables on employees' retirement expectations divided into imposed frustration, new beginning, transition to rest, and continuing. Independent variables were individual(gender, age, occupation, income, education, and health condition), psychological(self-esteem, locus of control, attitude of leisure, and attitude of family), and job-related variables(job attitude, job satisfaction, and job stability). In order to achieve this purpose, a survey was conducted with 515 employees from Daegu and Kyungpook. Retirement expectations were measured with questionnaire based on several studies. The data analyzed by frequency, percentage, mean, factor analysis, Cronbach's $\alpha$, correlation, and multiple regression. The major findings were as follows. First, imposed frustration was affected by income, self-esteem, locus of control, job satisfaction, job attitude, and job stability. Second, new beginning was affected by self-esteem, locus of control, attitude toward leisure and family, and job stability. Individual variables were not statistically significant predictors of new beginning. Third, transition to rest was affected by locus of control, attitude toward family, job satisfaction, job attitude, and job stability. Individual variables were not statistically significant predictors of transition to rest. Finally, continuing was affected by age, education, job satisfaction. Psychological variables were not statistically significant predictors of continuing.

• 대한기계학회논문집A
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• 제24권9호
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• pp.2361-2370
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• 2000

The introduction of inexpensive cylinder pressure sensors provides new opportunities for precise engine control. This paper presents a control strategy of spark advance based upon cylinder pressure of spark ignition engines. A location of peak pressure(LPP) is the major parameter for controlling the spark timing, and also the UP is estimated, using a multi-layer feedforward neural network, which needs only five pressure sensor output voltage samples at -40˚, -20˚, 0˚, 20˚, 40˚ after top dead center. The neural network plays an important role in mitigating the A/D conversion load of an electronic engine controller by increasing the sampling interval from 10 crank angle(CA) to 20˚ CA. A proposed control algorithm does not need a sensor calibration and pegging(bias calculation) procedure because the neural network estimates the UP from the raw sensor output voltage. The estimated LPP can be regarded as a good index for combustion phasing, and can also be used as an MBT control parameter. The feasibility of this methodology is closely examined through steady and transient engine operations to control individual cylinder spark advance. The experimental results have revealed a favorable agreement of individual cylinder optimal combustion phasing.

• Genomics & Informatics
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• 제3권1호
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• pp.1-7
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• 2005

Case-control studies are widely used for disease gene mapping using individual genotyping data. However, analyses of large samples are often impractical due to the expense of individual genotyping. The use of DNA pooling can significantly reduce the number of genotyping reactions required; hence reducing the cost of large-scale case-control association studies. Here, we discuss the design and analysis of DNA pooling genetic association studies.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.34-39
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• 1998

This paper describes the simulation approaches employed for a vector control system of induction motor drive using SIMNON for windows program. SIMNON program tool can solve differential and difference equations for nonlinear dynamical control system. One powerful feature is its ability of allowing integration of individual program modules after each individual module is programed and tested independently. This particular feature is exploited here for an SVPWM inverter drive by real-time modeling and simulation. The suggested programs are provided a simple and complete simulation for induction motor vector drive system.

• 한국자동차공학회논문집
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• 제5권1호
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• pp.186-194
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• 1997

The objective of this study is to develope knock control algorithms which can increase engine power without causing frequent knock occurrence. A four cylinder spark-ignition engine is used for the experiments to develop knock control algorithms which use block vibration signals. Knock occurrence is detected accurately by using knock threshold values which consider the difference of transmission path of each cylinder. Spark timing is controlled both simultaneously and individually. With the simultaneous control, torque gain is achieved by retarding the spark timing on knock occurrence in propotion to the knock intensity. The individual knock control algorithm results in higher torque gain than the simultaneous knock control algorithm. The knock occurrence frequency of the individual knock control algorithm is about twice the value of the simultaneous knock control algorithm results. Both control algorithms give similar torque gain of about 3% when they are optimized.

• 가정과삶의질연구
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• 제26권5호
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• pp.109-127
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• 2008

There are few studies on the characteristics of debtors in individual rehabilitation procedures, though research in this field is needed. The scarcity of research means that public policy and perception are being made with inadequate information and, to a certain extent, based on personal prejudices and misconceptions. The purpose of this study was to find out demographic, economic and psychological characteristics of debtors in individual rehabilitation procedures. For this study, an in-depth interview was used. The major findings were as follows : The focus of this study is debtors in individual rehabilitation procedures. They were all under 40 and received relatively high educations. Interestingly, they showed a high tendency to use debt and an inability to manage their money. They had short time horizons and imperfect self-control in consumption and borrowing decisions. Monthly income, expenditures, asset and debt of the debtors, and monthly payment to creditors were reported. There were a lot of reasons for their bankruptcy : business failure, job loss, the cost of raising children, and expenditures for entertainment causing them to file for individual rehabilitation procedures. One of the major conclusions of this study was the discovery that their psychological characteristics were nearly the same. The implications of the study suggest that financial education and counseling must consider psychological characteristics.