• 한국산업융합학회 논문집
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• 제23권5호
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• pp.773-787
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• 2020

In the injection molding process, the controlling stability of products quality is a very important factor in terms of productivity. Even when the optimum process conditions for the desired product quality are applied, uncontrollable external factors such as ambient temperature and humidity cause inevitable changes in the state of the melt resin, mold temperature. etc. Therefore, it is very difficult to maintain prodcut quality. In this study, a system that learns the correlation between process variables and product weight through artificial neural networks and predicts process conditions for the target weight was established. Then, when a disturbance occurs in the injection molding process and fluctuations in the weight of the product occur, the stability control of the product quality was performed by ANN predicting a new process condition for the change of weight. In order to artificially generate disturbance in the injection molding process, controllable factors were selected and changed among factors not learned in the ANN model. Initially, injection molding was performed with a polypropylene having a melt flow index of 10 g/10min, and then the resin was replaced with a polypropylene having a melt floiw index of 33 g/10min to apply disturbance. As a result, when the disturbance occurred, the deviation of the weight was -0.57 g, resulting in an error of -1.37%. Using the control method proposed in the study, through a total of 11 control processes, 41.57 g with an error of 0.00% in the range of 0.5% deviation of the target weight was measured, and the weight was stably maintained with 0.15±0.07% error afterwards.

• 한국산학기술학회논문지
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• 제11권9호
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• pp.3417-3421
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• 2010

USN은 인간의 생활공간, 생활기기, 기계 등 모든 사물에 컴퓨팅 및 네트워킹 기능을 부여하여 환경과 상황의 자동인지를 통해 사용자에게 최적의 서비스를 가능하게 함으로써 인간생활의 편리성과 안정성을 고도화 하는 기술이라 할 수 있다. 본 논문에서는 이와 같은 USN기술을 이용하여 학습자의 학습환경을 실시간으로 파악하여 이를 기초로 최적의 학습환경으로 만들어주기 위한 학습지원시스템을 임베디드 시스템 기반으로 개발한다.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2005년도 춘계공동학술대회 발표논문
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• pp.643-650
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• 2005

The object of this study is the development of a measuring framework for supply chain flexibility. Prior to treat supply chain flexibility, time flexibility, quantity flexibility, and cash-flow flexibility for each company are newly suggested. Especially, all developed measures can deal with the monetary point of view through various cost functions. Then weights of time flexibility, quantity flexibility, cash-flow flexibility are determined to find the effect of the level of flexibility in the supply chain. This is based on the relationship between the ratio of profit to revenue and value of three developed flexibility measures. To find the level of weight for each flexibility measure, neural network theory is used. Then the forecasting of the ratio of profit to revenue for all companies in the next period can be available. Therefore, all companies in the supply chain can control their operating processes to improve flexibility.

• 대한안전경영과학회지
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• 제9권3호
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• pp.119-125
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• 2007

As competition in manufacturing enterprise is contested, the scope of safely production planning, manufacturing enterprise should ensure, has been reduced. The more upstream of SCM, the more reduction of scope of production planning. As a result, order fluctuation is more sharply contested. Through improving the logistics network, it is best way that the end user's demand information is conveyed to upstream of SCM, but it is difficult in fact. In this paper, it mention the way of robustic adjustment, in the suppliers' point of view, the end user's demand information is dammed up, as they postpone responding the customer's order as a possible. And it will show the result of appling the way, as a case study.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2007년도 춘계학술발표논문집
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• pp.143-146
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• 2007

컴퓨터 네트워크에서 전송제어 프로토콜 상에서 다중시간 간격으로 혼잡제어의 지연을 피드백 루프의 시간간격을 조정하여 명시적 예측을 실행해 제어의 단점을 개선하는데 연구한다. 먼저 TCP의 모둘 형 확장에서 Tahoe, Reno, Vegas등 다양한 버전의 TCP에 적용되는 간단한 인터페이스를 통한 함수 호출을 정의하고, 이것이 성능을 크게 향상시는 것을 입증한다. 두 번째로, 광대역 WAN에서 지연-대역폭의 곱이 높을 경우 더욱 심각해지는 사후 제어의 불확실성 차이를 해소함으로써 MTS TCP가 기반 피드백 제어에 사전성을 부여한다는 것을 입증한다. 세번째는 트래픽 제어의 3가지 차원인, 즉 추적 능력, 연결 지속 기간, 공정성이 성능에 미치는 영향 등을 비교 분석하여 입증한다.

• 대한산업공학회지
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• 제34권3호
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• pp.289-295
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• 2008

The shared-route decision algorithms in multicasting communications networks to provide the internet-based services such as IPTV, remote education/health, and internet broadcasting are presented. The three main measures of maximum delay, average delay and estimated delay between each node and member are adopted. Under the Mesh network with the uniform random cost between each node, the algorithm's performance is compared to the optimal solution with the minimum cost by all enumeration. The simulation results show that the algorithm using the estimated delay outperforms the other two methods.

• 한국산업정보학회논문지
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• 제11권5호
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• pp.11-17
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• 2006

최근 디지털 기술들의 눈부신 발전을 거듭하고 있다. 이를 바탕으로 다양한 전자제품이 디지털화 되었고 그 대상이 점차 확대되고 있다. 이에 따라 임베디드 기술과 인터넷 기술이 결합된 임베디드 홈 오토메이션 시스템에 대한 개발이 많은 관심을 모으고 있다. 특히 유비쿼터스 시대를 맞이하여 일반 가정에도 경제적으로 우수한 홈 오토메이션 시스템을 선호하게 되었다. 따라서 본 연구에서는 현재 구현되고 있는 홈오토메이션시스템들의 단조로운 제어에서 탈피하여 지능화된 유비쿼터스 환경을 가정에 도입하기 위한 시스템을 설계하고자 한다.

• 한국산학기술학회논문지
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• 제5권1호
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• pp.49-54
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• 2004

본 논문은 자동차용 자동변속기의 변속전환 핵심 부품인 인히비터 스위치 케이스를 CAM을 활용하여 직접 제작하였다. 자동차 부품의 대부분은 주조로 만들어 대량생산과 복잡한 형상의 가공이 용이하지만 기계적 성질의 저하, 정밀도의 저하, 환경의 문제, 후처리를 해야하는 문제점이 있다. 이러한 문제점을 해결하기 위하여 CAM을 활용하여 제작함으로서 새로운 가공 방향을 제시하였다.

• 산업경영시스템학회지
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• 제21권45호
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• pp.47-56
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• 1998

This paper describes a moving path generation method for the Autonomous vehicles (AV) to search for paths in an unknown environment by using fixed obstacle information. Algorithms for the AV which were recently proposed have some problems, so it was difficult to utilize these algorithms in the real world. The purpose of this research is to examine the applicability of real-time control and efficient improvement by reducing calculation iterations. In the network which is constructed by the cell-decomposition method, a gate is installed in each cell. By verifying the possibility of gate pass-over, the number of cells which should be considered to find the solution can be reduce. Therefore, algorithm iterations can be dramatically improved. In this paper we have proven that path-generated algorithms are efficient by using simulation.

• 대한산업공학회지
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• 제26권4호
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• pp.315-324
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• 2000

This paper presents an efficient dynamic programming(DP) method, so called EDPAS (Efficient Dynamic Programming Algorithm for Signal), for optimally controlling traffic signal in real-time mode at a single intersection. The objective of EDPAS is to minimize total vehicle delay. It applies reaching method to solve forward DP functional equation, which does not need any priori knowledge on the states of DP network. Two acceleration techniques within reaching method are the main feature of EDPAS. They are devised to eliminate inferior DP states by comparing between states and maintaining incumbent value, resulting in a great amount of computational efficiency. An example is shown to verify the advantage of EDPAS.