• 전기학회논문지
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• 제61권7호
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• pp.1007-1013
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• 2012

Modeling of photovoltaic power systems is significant to analytically predict its dynamics in practical applications. This paper presents a novel modeling algorithm of such system by using probability and statistic theories. We first establish a linear model basically composed of Fourier parameter sets for mapping the input/output variable of photovoltaic systems. The proposed model includes solar irradiation and ambient temperature of photovoltaic modules as an input vector and the inverter power output is estimated sequentially. We deal with these measurements as random variables and derive a parameter learning algorithm of the model in terms of statistics. Our learning algorithm requires computation of an expectation and joint expectation against solar irradiation and ambient temperature, which are analytically solved from the integral calculus. For testing the proposed modeling algorithm, we utilize realistic measurement data sets obtained from the Seokwang Solar power plant in Youngcheon, Korea. We demonstrate reliability and superiority of the proposed photovoltaic system model by observing error signals between a practical system output and its estimation.

• 수산해양기술연구
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• 제30권1호
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• pp.25-32
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• 1994

An underwater speaker was made of a moving coil driver unite of usual speaker, acryl-boards, polyester resin, rubber and castor oil and it's frequency characteristics was measured in range of 250~600Hz in air water tank and sea. The results of measurements are follows: 1. Transmitting and receiving frequency of measurement frequency were similar in air, water tank and sea. 2. The input and output wave forms of a manufactured speaker which is not water-proof in air were similar to each other in 300~450Hz, but other frequencies showed distorted wave forms. 3. The input and output wave forms of an underwater speaker in water thank and sea were similar to each other in 250~600Hz. But output wave forms showed combination waves with very low frequency. 4. Transmitting and receiving frequency wave forms and resisting pressure of an underwater speaker at 80m in the depth of water were in good condition. Therefore it can be possible to use it as an underwater speaker.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.1-6
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• 1993

This report proposes a novel method of identification of continuous time-delay systems from sampled input-output data. By the aid of a digital pre-filter, an approximated discrete-time estimation model is first derived, in which the system parameters remain in their original form and the time delay need not be an integral multiple of th sampling period. Then an identification method combining the common linear least squares(LS) method or the instrumental variable(IV) method with the genetic algorithm(GA) is proposed. That is, the time-delay is selected by the GA, and the system parameters are estimated by the LS or IV method. Furthermore, the proposed method is extended to the case of multi-input multi-output systems where the time-delays in the individual input channels may differ each other. Simulation resutls show that our method yields consistent estimates even in the presence of high measurement noises.

• 유통과학연구
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• 제15권7호
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• pp.5-17
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• 2017

Purpose - This study analyzes an economic effect on the project that Korean government supported for the vitalization of traditional markets using an input-output model. From 2002 to 2013, the government provided 180.8 billion won for a Management Modernization Project and 2.851 trillion won for a Facility Modernization Project for vitalization of traditional markets. Research design, data, and methodology - The present study conducted inter-industry analysis by matching industries related to the Traditional Market Project for the measurement, and calculated the ripple effect of each project. Result - The results from the study showed that from 2002 to 2012, the Management Modernization Project and Facility Modernization Project showed a 296.1 billion won effect on production inducement, a 158.7 billion won value-added inducement effect, and a 3,135-person effect on employment inducement in total. From 2002 to 2013, the Facility Modernization Project showed a 6.948 trillion won effect on production inducement, a 2.1109 trillion won effect on value-added inducement, and 40,209-person of effect on employment inducement in total. Conclusions - This study provided an empirical demonstration of a clear effect of the governmental support to traditional markets on developing regional economies. In particular, this study empirically analyzed and presented that there were a considerable amount of an economic effect by region due to governmental policy support to traditional markets.

• Journal of Magnetics
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• 제8권4호
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• pp.160-163
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• 2003

In magnetic flux measurement, output voltage drift of electronic integrator is an essential problem. In this work, we have developed a new kind of Miller type integrator using a sample and hold amplifier. Input bias current was measured and this value was hold in the sample and hold amplifier, after that input bias current of Miller integrator was compensated automatically using the value which holds in the sample and hold amplifier. Developed flux-meter shows the drift of flux-meter are smaller than 10$^{-5}$ Wb/min in full scale of 10$^{-2}$, and we could also measure multi-channel magnetic flux simultaneously.

• 한국산업정보학회:학술대회논문집
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• 한국산업정보학회 2001년도 춘계학술대회논문집:21세기 신지식정보의 창출
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• pp.145-151
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• 2001

An extension of interaction matrix formulation to the problem of system and disturbance identification for a plant that is corrupter by both process and output disturbances is presented. With only an assumed upper bound on the order of the system and an assumed upper bound on the number of disturbance frequencies, it is shown that both the disturbance-free model and disturbance effect can be recovered exactly from disturbance-corrupted input-output data without direct measurement of the periodic disturbances. The rich information returned by the identification can be used by a performance-oriented model-based loaming or repetitive control system to eliminate unwanted periodic disturbances.

• 한국컴퓨터정보학회논문지
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• 제8권4호
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• pp.165-175
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• 2003

국제적으로 측정결과의 신뢰성을 판단할 수 있는 척도로서 불확도(Uncertainty)개념이 도입되고 국제 표준화기구(ISO)가 여러 국제기구와 합동으로 "측정불확도표현지침(GUM)"을 1993년에 발간하게 되었다. 본 논문에서는 시료의 산포가 존재하는 경우 시료산포를 불확도 인자로 적용하여 측정결과에 대한 불확도를 평가할 수 있는 측정모델을 구축하여 제시하고, GUM에서 제시한 불확도 전파법칙의 문제점을 분석하여 이를 보완할 수 있는 새로운 불확도의 평가방법으로 몬테칼로 시뮬레이션을 이용한 컴퓨터프로그램 활용의 필요성을 논하고자 한다. 또한 이러한 이론적 근거를 바탕으로 하여 불확도를 평가할 수 있는 컴퓨터 프로그램 개발사례를 제시하고자 한다. 제시하고자 한다.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.200-204
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• 2015

This paper presents 10 input measures influencing project outcomes. Construction Industry Institute (CII), a consortium of more than 130 project owner and contractor companies, has collected project-level data for over 20 years. Recently, CII has developed a new system measuring project-level performance and factors presumably influencing project performance. The system, called 10-10, collects data for 10 input and 10 output measures for capital projects. The input measures include planning, organizing, leading, controlling, design efficiency, human resources, quality, sustainability, supply chain, and safety. This paper provides theoretical background for these measures. Although the input measures have been known to impact on project outcomes such as cost and schedule, there has been no study quantitatively evaluating how they are operated in the construction industry. This study contributes to revealing the current status of their uses, which will be helpful in establishing strategies improving construction project performance.

• Transactions on Electrical and Electronic Materials
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• 제12권6호
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• pp.241-244
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• 2011

An isolator transmits light in the forward direction and blocks light from passing in the reverse direction. It is regarded an essential optical component in medical, industrial, and research lasers for blocking reflection beams that cause optical damage and noise. It is also used as a communicative light intensifier to expand the lifespan of devices and enhance transmission quality. This study analyzed the characteristics of the core components in the construction of a polarization-independent isolator, namely, the walk-off polarizer and the Faraday rotator. Measurement of the extinction ratio of the resultant walk-off polarizer revealed that the ratio between the vertical and horizontal rays was 1,050:1 with a laser output of 0.032 W and 1,010:1 with a laser output of 2.68 W, thus presenting ratios similar to 1,000:1. In addition, the walk-off polarizer and Faraday rotator constructed in this study were used to compare output changes according to changes in power of input light and to check the penetration ratio. Results from the study presented variations in output value according to changes in power of input light. However, the average penetration ratio remained relatively consistent (~81.4%).

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.145-149
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• 1993

This paper considers the adaptive predictive control problem of a system characterized by a multiplexed measurements and multirate sampling mechanism. Plant outputs are measured in various sampling rates through a multiplexed measurement system where a single common instrument is shared by several controllers. In general, output measurement sampling rate is assumed to be slower that input update rate. An adaptive predictive control algorithm is developed for systems with multiplexed measurements.