• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2001년도 추계학술대회 논문집
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• pp.121-124
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• 2001

On-line prediction model which calculate roll force, roll power and forward slip of continuous hot strip rolling was built based on the results of plane strait rigid-viscoplastic finite element process model. Using the integrated FE process model, a series of finite element simulation was conducted over the process variables, and the influence of various process conditions on non-dimensional parameters was inspected. The prediction accuracy of the proposed on-line model under front and back tension is examined through comparison with predictions from a finite element process model over the various process conditions. In addition, we examined the validity of the on-line prediction model through comparison with roll force of experiment in hot rolling.

• 한국시뮬레이션학회논문지
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• 제11권4호
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• pp.69-80
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• 2002

This study deals with the productivity improvement on a flow production system with the consideration of line-balancing. In a flow production system, similar product models are produced on a same assembly line, the predefined process order and the limitation of total worker number. The system can be increased the work-in -process(WIP) inventory and the worker's idle time. In this study, the worker assignment model is developed to assign evenly workload of process to each product model in such a manner that each process has the different number of worker. This worker assignment model is the mathematical model that determines worker number in each process such that the idle time of processes is reduced and the utilization of worker is improved. We use a simulation technique to simulate the production line proposed by the mathematical model and apply real production line. With the result of simulation, this study analyzes the propriety of production line and proposes the alternatives of new production line

• 산업경영시스템학회지
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• 제5권6호
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• pp.49-53
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• 1982

Because of the ever increasing demands of consumers for a greater choice of product models, manufacturers are forced to produce a wider variety of models. Therefore, more and more assembly lines are being converted to handle the larger number. As the complexity in achieving an efficient mixed model assembly line is related to the degree of likeness between models on the line. To measure likeness between two or more models an method was developed in this study, which is based on the association of work element and their processing times on each model for mixed model assembly line.

• 한국콘텐츠학회논문지
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• 제9권10호
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• pp.492-499
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• 2009

본 연구는 학습자의 효과적 학습을 위해 온라인 상 콘텐츠 품질을 구성하는 요소와 오프라인 강의가 콘텐츠 품질을 인식하는데 얼마나 영향을 주는가를 알아보기 위한 연구이다. 다속성 태도모델(multiattribute attitude model)의 속성만족도-중요도 모델(attribute satisfaction-importance model)을 중심으로 온라인 학습에 있어 콘텐츠 품질이 학습태도에 미치는 영향과 오프라인 강의를 병행했을 때의 학습태도(learning attitude) 형성의 변화에 대한 관계를 살펴보고자 한다. 콘텐츠 만족도에 대한 신념(belief)은 콘텐츠 품질을 구성하는 요소로 음성강의, 동영상강의, WBI방식 강의로 나누어 평가한다. 여기에 웹상의 강의와 오프라인 강의를 병행했을 때 형성되는 학습태도의 변화에 대해 연구한다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2001년도 추계학술대회 논문집
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• pp.134-137
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• 2001

In this paper on-line model is derived from investigating via series of finite element process simulation. Some variables that little affect on non-dimensional parameters. ie. forward slip and torque factor. is extracted from composing on-line model Especially, this research focused on deriving on-line model which exactly predict roll force and roll power in the roughing mill process under small shape factor and small reduction ratio. The prediction accuracy of the proposed model is examined through comparison with predictions from a finite element process model

• 대한전기학회논문지:전력기술부문A
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• 제48권10호
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• pp.1293-1302
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• 1999

In this paper, an on-line process scheme is presented for implementation of a intelligent on-line modeling of nonlinear complex system. The proposed on-line process scheme is composed of FNN-based model algorithm and PLC-based simulator, Here, an adaptive fuzzy-neural networks and HCM(Hard C-Means) clustering method are used as an intelligent identification algorithm for on-line modeling. The adaptive fuzzy-neural networks consists of two distinct modifiable sturctures such as the premise and the consequence part. The parameters of two structures are adapted by a combined hybrid learning algorithm of gradient decent method and least square method. Also we design an interface S/W between PLC(Proguammable Logic Controller) and main PC computer, and construct a monitoring and control simulator for real process system. Accordingly the on-line identification algorithm and interface S/W are used to obtain the on-line FNN model structure and to accomplish the on-line modeling. And using some I/O data gathered partly in the field(plant), computer simulation is carried out to evaluate the performance of FNN model structure generated by the on-line identification algorithm. This simulation results show that the proposed technique can produce the optimal fuzzy model with higher accuracy and feasibility than other works achieved previously.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2009년도 춘계 종합학술대회 논문집
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• pp.373-377
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• 2009

본 연구는 학습자의 효과적 학습을 위해 온라인 상 콘텐츠 품질을 구성하는 요소와 오프 강의가 콘텐츠 품질을 인식하는데 얼마나 영향을 주는가를 알아보기 위한 연구이다. 다속성 태도모델(multiattribute attitude model)의 속성만족도-중요도 모델(attribute satisfaction-importance model)을 중심으로 온라인 학습에 있어 콘텐츠 품질이 학습태도에 미치는 영향과 오프 강의를 병행했을 때의 학습태도(learning attitude) 형성의 변화에 대한 관계를 살펴보고자 한다. 콘텐츠 만족도에 대한 신념(belief)은 콘텐츠 품질을 구성하는 요소로 음성강의, 동영상강의, WBI방식 강의로 나누어 평가한다. 여기에 웹상의 강의와 오프강의를 병행했을 때 형성되는 학습태도의 변화에 대해 연구한다.

• 대한전기학회논문지:전력기술부문A
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• 제51권3호
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• pp.118-126
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• 2002

AVR parameter tuning for voltage control of generators has generally been done with the off-line open-circuit model of the synchronous generator. When the generator is connected on-line and operating with load the AVR operates in an entirely different environment from the open-circuit conditions. This paper describes a new method for AVR parameter tuning for on line conditions using SQP(Sequential Quadratic Programming) meshed with frequency response characteristics of linearized on-line system model. As the proposed method uses the un - line system model the tuned parameter sets show more optimal behavior in the on-line operating conditions. furthermore, as this method considers the performance indices that are needed for stable operation as constraints, AVR parameter sets that are tuned by this method could guarantee the stable performance, too.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2000년도 춘계학술대회논문집
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• pp.52-55
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• 2000

Investigated via a series of finite element process simulation is the effect of diverse process variables on some selected non-dimensional parameters characterizing the strip in hot strip rolling. Then on the basis of these parameters an on-line model is derived for the precise prediction of roll and roll power. The prediction accuracy of the proposed model is examined through comparison with predictions from a finite element process model.

• 한국산업정보학회논문지
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• 제15권3호
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• pp.59-65
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• 2010

This paper proposes a modified heuristic mixed model assembly line (MMAL) balancing algorithm that provides consistent station assignments on a model by model basis as well as on a station by station. Basically, some of single model line balancing techniques are modified and incorporated to be fit into the MMAL. The proposed algorithm is based on N.T. Thomopoulos' [8] method and supplemented with several well proven single model line balancing techniques proposed in the literature until recently. Hoffman's precedence matrix [2] is used to indicate the ordering relations among tasks. Arcus' Rule IX [1] is applied to generate rapidly a fairly large number of feasible solutions. Consequently, this proposed algorithm reduces the fluctuations in operation times among the models as well as the stations and the balance delays. A numerical example shows that the proposed algorithm can provide a good feasible solution in a relatively short time and generate relatively better solutions comparing to other three existing methods.