• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 제5회 압연심포지엄 신 시장 개척을 위한 압연기술
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• pp.175-183
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• 2004

In hot strip rolling, a capability for precisely predicting roll force is crucial for sound process control. In the past, on-line prediction models have been developed mostly on the basis of Orowan's theory and its variation. However, the range of process conditions in which desired prediction accuracy could be achieved was rather limited, mainly due to many simplifying assumptions inherent to Orowan's theory. As far as the prediction accuracy is concerned, a rigorously formulated finite element(FE) process model is perhaps the best choice. However, a FE process model in general requires a large CPU time, rendering itself inadequate for on-line purpose. In this report, we present a FE-based on-line prediction model applicable to precision process control in a finishing mill(FM). Described was an integrated FE process model capable of revealing the detailed aspects of the thermo-mechanical behavior of the roll-strip system. Using the FE process model, a series of process simulation was conducted to investigate the effect of diverse process variables on some selected non-dimensional parameters characterizing the thermo-mechanical behavior of the strip. Then, it was shown that an on-line model for the prediction of roll force could be derived on the basis of these parameters. The prediction accuracy of the proposed model was examined through comparison with measurements from the hot strip mill.

• Industrial Engineering and Management Systems
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• 제7권2호
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• pp.160-170
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• 2008

This paper proposes a mathematical model for converting conveyor assembly line to cellular manufacturing in complex production environments. Complex production environments refer to the situations with multi-products, variant demand, different batch sizes and the worker abilities varying with work stations and products respectively. The model proposed in this paper aims to determine (1) how many cells should be formatted; (2) how many workers should be assigned in each cell; (3) and how many workers should be rested in shortened conveyor line when a conveyor assembly line should be converted, in order to optimize system performances which are defined as the total throughput time and total labor power. We refer the model to a new production system. Such model can be used as an evaluation tool in the cases of (i) when a company wants to change its production system (usually a belt conveyor line) to a new one (including cell manufacturing); (ii) when a company wants to evaluate the performance of its converted system. Simulation experiments based on the data collected from the previous documents are used to estimate the marginal impact that each factor change has had on the estimated performance improvement resulting from the conversion.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 C
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• pp.1242-1244
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• 1999

AVR parameter tuning for voltage control of power system generators has generally been done with the open-circuit model of the synchronous generator. When the generator is connected on-line and operating at rated load conditions, the AVR operates in an entirely different environment from the open-circuit conditions. This paper describes a new method for AVR parameter tuning using optimization technique with on-line linearized system model. As this method considers not only the on-line models but also the off-line open-circuit models, AVR parameters tuned by this method can give the sufficiently stable performance at the open-circuit commissioning phase and give the desired performance at the operating conditions. Also this method estimates the optimum parameters for desired performance indices that are chosen for satisfying requirements in some practical applications, the performance of the AVR can satisfy the various requirements.

• Journal of information and communication convergence engineering
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• 제7권1호
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• pp.1-6
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• 2009

In order to obtain a 3-D urban model, an abstraction of the surface model is required. This paper describes works on the 3D reconstruction and modeling by the grouping 3D line segments extracted from the stereo matching of edges, which is derived from multiple images. The grouping is achieved by conditions of degrees and distances between lines. Building objects are determined by the junction combinations of the grouped line segments. The proposed algorithm demonstrates effective results of 3D reconstruction of buildings with 2D aerial images.

• 전기의세계
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• 제29권1호
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• pp.65-72
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• 1980

Arstrong-Whitehead theory on effective shielding and shielding failure is extended so that it is applicable to vertical line configuration the existing approaches on back-flash rate calculation are summerized and compared in particular on Model Line, and the usefulness of the whitehead approach is suggested.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 춘계학술대회논문집
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• pp.176-179
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• 2003

The mean temperature prediction of strip is very important in hot strip finishing mill because of affecting on product quality and shape. Also, temperature can be used by basic information in other on-line control models with affecting control accuracy in factory. So, FE based on-line temperature model was developed for predicting strip mean temperature accurately in various process conditions and factory environments. There are many variables in affecting strip mean temperature in on-line states of factory. But some problems are occurred in considering all variables for making temperature model because of the bad efficiency of regression or fitting analysis. In this report, we have adopted dimensional analysis for solving these problems. We have many variables with dimensions affecting strip temperature but we are able to make non-dimensional variables less than dimensional variables from the combination of dimensional variables caused by PI-Theorem in fluid mechanics. The developed models are divided by two parts. The one is interstand temperature prediction model. The other is roll gap temperature model.

• 한국정보과학회논문지:소프트웨어및응용
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• 제32권2호
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• pp.119-127
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• 2005

제품계열분석(product line analysis)은 제품계열자산(product line asset)을 개발하기에 앞서, 제품계열 내에 속한 제품들의 다양한 요구사항과 이들 간의 관계 및 제약사항을 분석하는 활동을 말한다. 지금까지 특성모델링(feature modeling)이라 불리는 특성 지향의 공통성과 가변성 분석은 제품계열분석의 핵심적인 부분으로 간주되어 왔다. 비록 공통성과 가변성 분석이 제품계열분석의 핵심적인 요소이지만, 이것만으로는 재사용가능하고 적응성이 뛰어난 제품계열자산(예, 아키텍처와 컴포넌트) 개발에 한계가 있다. 특성간의 의존성 및 특성결합시간도 제품계열자산 개발에 중대한 영향을 미치는 요소이다. 따라서 본 논문에서는 기존에 공통성과 가변성 관점에서 제품계열을 분석한 결과인 특성모델(feature model)을 세 가지의 특성 측면(즉, 제품특성의 공통성과 가변성, 특성간의 의존성, 그리고 특성결합시간)으로 확장한 특성지향의 제품계열분석 모델을 제안한다. 특히, 세 가지 측면의 일관성을 검증하기 위해서, 특성 지향의 제품계열분석 모델을 정형적으로 정의하고, 모델의 일관성을 검사하는 규칙을 제공한다.

• 한국멀티미디어학회논문지
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• 제9권12호
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• pp.1657-1668
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• 2006

The last few years have represented a boom for the online gaming industry. Internet-based online games have been an increasingly popular form of entertainment. The gaming industry estimates there will be over 26 million online gaming participants in 2002. The rapid development of online game content and related information technology will increase the size of the industry and have a profound impact on many aspects of our lives and our society. This paper develops the exploratory LISREL model for identifying the factors affecting the players' loyalty to a specific brand of online game. The concepts of flow, word of mouth, feedback, challenge, social norms, and online community activities, etc, are all introduced into the model, as the independent variables directly and indirectly affecting loyalty. Based on data collected from an online survey, the validity of the model has been tested and interesting conclusions have been developed concerning the relationships between loyalty and flow, word of mouth, and other independent variables. It is hoped that this result might provide useful guidelines for developing successful online game content.

• Journal of Power Electronics
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• 제15권6호
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• pp.1628-1639
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• 2015

Line-interactive uninterruptible power supply (UPS) systems are good candidates for providing energy storage within a microgrid. In this paper, a control scheme for a line-interactive UPS system applied in a low-voltage microgrid is presented. It is based on the Q-w and P-E droop control to achieve a seamless transition between grid-connected and stand-alone operation modes. Moreover, a new model for designing the controllers is built in the dq-frame based on the instantaneous power definition. The new-built model takes into account the dynamic performance of the output impedance of the inverter in the dq-frame and can be evaluated in the time domain. Compared to the traditional model based on the instantaneous power definition, the new-built model is more accurate to describe the dynamic performance of the system. Simulation and experimental results obtained with a microgrid consisting of two 40-kW line-interactive UPS systems are given to validate the control strategy of the line-active UPS system and the accuracy of the new-built model.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제5권11호
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• pp.585-592
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• 2016

글이나 대화를 일정한 주제의 단위로 나누는 것을 주제 분리라고 한다. 지금까지 주제 분리는 주로 완결된 하나의 문서에서 최적화된 분리를 찾는 방향으로 진행되어 왔다. 하지만 몇몇 응용은 글이나 대화가 진행 중에 주제 분리를 할 필요가 있다. 본 논문에서는 합성곱 신경망을 이용한 교사 학습 모델을 통해 문장의 진행 중에 주제 분리를 수행하는 모델에 대해 제안한다. 그리고 제안한 모델의 성능 검증을 위해 On-line 상황을 가정한 실험과 기존의 C99모델을 결합한 실험을 수행하였다. 실험결과 각각 17.8과 11.95의 Pk 점수를 얻었고, 이를 통해 본 논문의 모델을 통한 On-line 상황에서의 주제 분리 활용의 가능성을 확인하였다.