• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.25-26
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• 2006

The method measuring the absolute position of a point diffraction source emitting a spherical wavefront in three-dimension is proposed. Two-dimensional interference of spherical wavefronts is used to overcome ambiguity of phase order. The spherical wavefront is explicated by Taylor series expansion, from which a radius of curvature of a spherical wavefront and its center position in three-dimension are obtainable. The spherical wavefront is reconstructed by a modified lateral shearing interferometer, which uses single-mode fiber as a point diffraction source.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1997년도 추계학술대회논문집
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• pp.313-319
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• 1997

There is currently a focus on usability of interactive computer software. Previous research in software ergonomics has indicated the importance of evaluating the usability of software user interfaces. Software developers, interface designers or human foctors engineers often confront the task of comparative evaluation among systems, versions or interface designs. This study presents a structured model for comparative evaluation of user interface designs using usability criteria and measures. The proposed model consists of twomain phases : the prescreening phase ad the evaluation phase. The first phase involves expert judgment-based approach with qualitative criteria. The prescreening phase uses absolute measurement analytic hierarchy process to filter possible altermative interfaces to a reasonable subset. The second phase involves user-based approach such as usability testing, with quantitative criteria. The objective of the evaluation phase is to evaluate a subset of altermatives using objective measures. A set of criteria and measures for evaluating the usability of computer software designs is presented. The proposed model provides practitioners with a structured approach to select the best interface based on usability criteria and measures.

• 한국정보통신학회논문지
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• 제15권5호
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• pp.1018-1024
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• 2011

최대 토크를 발휘하도록 정현파형 영구자석형 동기전동기를 구동하기 위해서는 회전자 절대위치에 동기화된 120도 위상차를 갖는 3상 정현파 전류 입력이 고정자 코일에 요구된다. 그러므로 회전자 절대위치 검출이 필연적이다. 그리고 고정자 자계와 회전자 자계 사이의 90도 위상 관계가 정류 동작에 의해 유지되어야 한다. 정류를 위한 절대 위치 검출은 일반적으로 모터 축에 부착된 엔코더 출력 신호의 분석에 의해 이루어진다. 본 연구는 현대의 엔코더 시스템을 부착한 모터의 절대위치를 검출 할 수 있는 신호처리 논리회로 설계를 목적으로 하며, 고정자 코일에 정현파 전류 입력을 만들어주기 위한 삼상 기준파형을 발생시킨다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.912-914
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• 2002

Single phase SRM(Switched Reluctance Motor) can not be started by itself and torque ripple is more generated than multi-phase SRM. But it is excited by single phase current and has very simple structure. Therefore it can be used in domestic appliance. Torque and speed of single phase SRM is controlled by adjusting exciting current and exciting section. Driver, which is composed with absolute encoder and DSP, is fabricated for control of exciting section on this paper. Then driving characteristics with exciting section is confirmed by using salient pole rotor type single phase SRM, which is fabricated in preceding research.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1304-1306
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• 1995

In this study, a neural network algorithm through a data standardization method was developed to discriminate the phase-shifted partial discharge(PD) patterns such as a $\phi$-q-n pattern. Considering the PD measurement in the field, it is not so easy to acquire absolute phase angles of PD pulses. As a consequence, one of the significant problems to be solved in applying the neural network algorithm to practical systems is to develop a method that can discriminate phase-shifted $\phi$-q-n patterns. Therefore, authors established a new method which could convert phase-shifted $\phi$-q-n patterns to a standardized $\phi$-q-n pattern which was not influenced by phase shifting. This new standardization method improved the recognition performance of a neural network for the phase-shifted $\phi$-q-n patterns considerably.

• 산업경영시스템학회지
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• 제29권2호
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• pp.7-12
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• 2006

This study considers the problem of scheduling jobs on uniform parallel machines with a common due date. The objective is to minimize the total absolute deviation of job completion times about the common due date. This problem is motivated by the fact that a certain phase of printed circuit board manufacturing is bottleneck and the processing speeds of parallel machines in this phase are uniformly different for all jobs. Optimal properties are proved and a simple polynomial time optimal algorithm is developed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.887-888
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• 2006

Switched Reluctance Motor(SRM) is rotated by reluctance force generated between rotor pole and stator pole. So SRM must be switched by exciting current according to rotor position. but SRM takes the advantages of high speed driving and very simple structure. The single phase SRM can not be start by itself and torque ripple is generated more than multi-phase SRM. But mechanical structure and driver is simpler than multi-phase SRM. The single phase SRM driver is composed with the absolute encoder and DSP to control exciting section and current, and is supplied by constant voltage. So The paper is intend to measure the speed charactrer of double silent pole type SRM by using the unipolar driving curcuit.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.72-76
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• 2015

Capital project benchmarking requires an effective cost normalization process to compare cost performance of projects accomplished in different time and location. Existing cost normalization approaches have been established based on the assumption that all required information for cost normalization is fully identified once a project is completed. Cost normalization, however, is sometimes required to evaluate phase-level outcomes of an ongoing project where the required information is not fully available. This paper aims to provide a cost normalization procedure for phase-based performance assessment. The procedure consists of three normalization steps: currency conversion, location adjustment, and time adjustment considering various scenarios where the required information is not fully identified. This paper also presents how the cost normalization procedure has been applied to the 10-10 Performance Assessment Program, which is a phase-based performance assessment system developed by the Construction Industry Institute (CII). Both researchers and industrial professionals can apply the cost normalization procedure to studies and practices regarding to cost estimation, feasibility analysis, and performance assessment.

• 정신신체의학
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• 제3권2호
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• pp.115-125
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• 1995

Reports about the prevalence of premenstrual symptoms state that occurs in 20 to 100% of most reproductive-age women. There is a close association between premenstrual syndrome and affective disorders as well as same some other psychiatric disorders. Late luteal phase dysphoric disorder (LLPDD) is a premenstrual condition defined in DSM-III-R by severe mood changes and other symptoms that repeatedly occur only in the luteal phase of the menstrual cycle. However, DSM-III-R does not specify how to compute the change from the follicular to the luteal phase or how to determine when the amount of change is great enough to warrant the diagnosis nor how to determine occupational or social functional impairment. This study was conducted to evaluate the nature, severity and magnitude of premenstrual syndrome in women with current psychiatric disorders by using prospective Daily Rating Form(DRF), and to measure symptom changes according to three scoring methods for diagnosing LLPDD. Our study obtains the data about premenstrual changes estimated by DRF from 22 women with psychiatric disorders who had met criteria for major depressive syndrome on the Premenstrual Assessment Form (PAF). The data was scored by each three methods and was determined to meet criteria A for LLPDD. The results are as follows: 1) the subjects, when scored according to the percent change method, effect size method and absolute severity method, met the DSM-III-R criteria A for LLPDD in 36.4% (8 subjects), 14% (3 subjects) and 4.5% (1 subject) of the cases respectively. 2) The items of irritability, anger and impatience were occurred most frequently on the DRF, when it was scored according to the three scoring methods. And the item of breast pain was next frequent according to the effect size method and the percent change method but according to the absolute severity method. 3) The PAF item of impaired social functioning was reported by 16 (73%) of the subjects. 4) 4 (18%) of the subjects met criteria A for LLPDD and reported impaired social functioning. The prevalency of LLPDD according to each method varied. The percent change method yielded the greatest (36.4%), and the absolute seventy method yielded the laest (4.5%), The effect size method yielded an intermediate frequency (14%). Therefore, for maximizing the diagnostic accuracy of LLPDD, a diagnostic procedure including a measure of change (e.q., effect size method, percent change method) as well as confirmed diagnosis by DRF, will be needed. Also, an accurate tool to evaluate impaired social functioning will be required.

• 조명전기설비학회논문지
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• 제26권6호
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• pp.38-46
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• 2012

In this paper, the necessity for the identification of the absolute phase value is introduced and analyzed for a particular conductor line of a 3-phase type distribution network and the recent methods are also introduced. For the determination of the exact phase value for a specific point in the line, as compared with the phase reference point, the measured phase value must be within a range of ${\pm}60[^{\circ}]$. However, the phase of a particular point can fluctuate depending on the line constant, transformer wiring method, line length, line amperage, etc. A theoretical formulation such as Simulink modeling and analysis for a distribution network are conducted for the identification of phase at a specific point in the line. In particular, through evaluating the effects of unbalanced current loads at the time of determination of the phase value, the limitations of the present method for the determination of phases is described.