• 한국미생물·생명공학회지
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• 제19권5호
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• pp.521-535
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• 1991

Cephalosporium 배양시 균체의 형태학적 측면을 고려한 cephalosporin C 생합성에 대한 모델식을 제안하였다. 제한기질로 glucose와 methionine을 고려한 double-substrate 모델을 설정하였는데 여기서 glucose는 균체의 증식 정도를, methionine은 균체의 증식속도를 제어하게 된다. Cephalosporin C의 생산은 균체의 형태학적 분화와 밀접한 관계가 있다. 한편 cephalosporin C의 생산성을 증대시키기 위해 모델식을 유가식 배양에 응용하였다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.223-224
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• 2023

Optimal fleet management in the planning stage is one of the most critical activities that guarantee successful construction projects. In South Korea, the construction standard production rate database (CSPRD) is normally employed. However, when it comes to a trade-off problem that involves decision-making on optimal sets of equipment to perform a certain task, the method will require the planners' in-depth knowledge and experience regarding the target process and a time consuming estimation of the performance of every possible scenario must be conducted for the deduction of the optimal fleet management. On this account, this research paper proposes a lightweight method of using mixed integer nonlinear programming (MINLP) in multi-objective problems based on CSPRD-based mathematical equations to assist planners in the preplanning stage of choosing the optimal sets of types and size machinery to efficiently arrange the construction scheduling and budgeting.

• 대한전기학회논문지
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• 제39권10호
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• pp.1108-1120
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• 1990

본 논문에서는 소량 다품종 생산에서 FMS(Flexible Manufactturing System)의 공정제어를 위한 지능형 제어기를 설계하였다. 설계된 제어기는 최적화 기법과 경험적 생산 규칙을 통합하여 가공품의 적재 및 흐름이 제어되고 선정된 성능 평가 기준 지표를 최대로 만족할 수 있도록 한다. 최적화 기법에 의해 구현되는 제어 기능은 생산시스템의 가공용량을 초과하지 않는 범위내에서 가공품의 순시생산율을 계산한다. 생산규칙 구성에 따르는 경험적 제어를 위하여 지식베이스가 형성되고 순시생산율 및 현재의 공정 정보를 기반으로 최종 대안이 선정된다. 이 경우 지식 베이스에는 대안 심사, 결정수립 기준, 그리고 가공품의 흐름제어에 관한 규칙들을 대상으로, 그리고 데이타베이스는 공정 정보 관리, 수정 침 저장을 대상으로 각각 구축된다. 공정 정보를 이용하여 생산계획의 진행 상황을 도시하게 되는 글래픽 시뮬레이션이 수행되며, 설계된 제어기의 성능평가는 컴퓨터 시물레이션을 통해 검토된다.

• 산업경영시스템학회지
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• 제38권4호
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• pp.159-167
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• 2015

We consider a wafer lot transfer/release planning problem from semiconductor wafer fabrication facilities to probing facilities with the objective of minimizing the deviation of workload and total tardiness of customers' orders. Due to the complexity of the considered problem, we propose a two-level hierarchical production planning method for the lot transfer problem between two parallel facilities to obtain an executable production plan and schedule. In the higher level, the solution for the reduced mathematical model with Lagrangian relaxation method can be regarded as a coarse good lot transfer/release plan with daily time bucket, and discrete-event simulation is performed to obtain detailed lot processing schedules at the machines with a priority-rule-based scheduling method and the lot transfer/release plan is evaluated in the lower level. To evaluate the performance of the suggested planning method, we provide computational tests on the problems obtained from a set of real data and additional test scenarios in which the several levels of variations are added in the customers' demands. Results of computational tests showed that the proposed lot transfer/planning architecture generates executable plans within acceptable computational time in the real factories and the total tardiness of orders can be reduced more effectively by using more sophisticated lot transfer methods, such as considering the due date and ready times of lots associated the same order with the mathematical formulation. The proposed method may be implemented for the problem of job assignment in back-end process such as the assignment of chips to be tested from assembly facilities to final test facilities. Also, the proposed method can be improved by considering the sequence dependent setup in the probing facilities.

• 한국CDE학회논문집
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• 제12권1호
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• pp.1-7
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• 2007

In this paper, we present a machining time estimation algorithm for 5-axis high-speed machining. Estimation of machining time plays an important role in process planning and production scheduling of a shop. In contrast to the rapid evolution of machine tools and controllers, machining time calculation is still based on simple algorithms of tool path length divided by input feedrates of NC data, with some additional factors from experience. We propose an algorithm based on 5-axis machine behavior in order to predict machining time more exactly. For this purpose, we first investigated the operational characteristics of 5-axis machines. Then, we defined some dominant factors, including feed angle that is an independent variable for machining speed. With these factors, we have developed a machining time calculation algorithm that has a good accuracy not only in 3-axis machining, but also in 5-axis high-speed machining.

• 복식문화연구
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• 제17권3호
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• pp.512-522
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• 2009

The purpose of this study is to analyze IT infrastructure of Korean apparel industry in order to enhance business effectiveness and customer's satisfaction in information society with global networks. For this study, the questionnaires were distributed to 57 apparel industries in Korea. The data were analyzed by factor analysis, descriptive statistics, Cronbach's alpha coefficient, multi regression analysis. The results of this study are as follow: First, Considering the apparel industry, construction of information system is essential for assistance of information policy and utilization of information. Understanding of e-business policy affects profits of suppliers. Second, Apparel industry with higher information policy has higher productivity with flexibility. Third, Apparel industry which has close relationship with suppliers has better customer support. Flexible scheduling and production line are important factors for quick response of customer's order and need.

• 산업경영시스템학회지
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• 제20권42호
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• pp.193-200
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• 1997

For the industrialized nations, the manufacturing industries have becomes increasingly difficult to meet customers' demands and complete on the international market. Thus, manufacturing industries must be able tn react quickly to prevailing market conditions and to maximize the utilization of resources. Within recent years, computer technology, in conjunction with software technology, has made available to the manufacturer tools which can greatly improve their reaction to a new market situation, speeding up the design of products, improving process planning, maximizing resource scheduling, and streamling production flow through factories. This paper investigate "CALS" systems for motor's companies. The purpose of this study is to give some ideas of finding a better way of constructing "CALS" system in Korea motor's companies.a motor's companies.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.354-356
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• 2011

Renewable energy resources such as wind, wave, solar, micro hydro, tidal and biomass etc. are becoming importance stage by stage because of considering effect of the environment. Solar energy is one of the most successful sources of renewable energy for the production of electrical energy following solar energy. And, the solar/photovoltaic cell generators depend on the solar radiation, which is a random variable so this poses difficulty in the system scheduling and energy dispatching, as the schedule of the photovoltaic cell generators availability is not known in advance. This paper proposes to use the two-layered artificial neural networks for predicting the actual solar radiation from the previous values of the same variable.

• 한국전자거래학회지
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• 제1권1호
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• pp.227-247
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• 1996

Presented in this paper is a control model for developing virtual factory simulator, which is being operated under the distributed environment. The control model consists of production activity plan and information flows. To incorporate elements of the characteristics of the distributed control system, we suggested a collaboration model. This model is working under the client/server architecture, and also designed for cooperative-distributed shop control(CDSC) system in order to exploit several advantages of client/server architecture. Collaboration among each agent(or client) is done through negotiation and task sharing. Based on a contract net model, the CDSC system has three kinds of agents-order agent, resource agent, and communication forwarding agent. Each agent performs shop scheduling and control through negotiation on contract net. No node in CDSC system can have authority over other node. A bidding scheme is employed far negotiation between order agent and resource agents. The CDSC system can support re-negotiation among resource agents and an algorithm for re-negotiation is also developed. Experimental results are shown to advocate the effectiveness of the CDSC system for CIM environments.

• 산업공학
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• 제13권3호
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• pp.358-377
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• 2000

A supply chain is a network of facilities and distribution options that performs the functions of procurement of materials, transformation of these materials into intermediate and finished products, and the distribution of these finished products to customers. SCM(Supp1y Chain Management), by definition, encompasses all activities associated with moving goods, from the raw materials stage through to the end user. It includes source and procurement, production scheduling, order processing, inventory management, transportation, warehousing, and customer service. Importantly, it encompasses the information systems used to monitor these activities. In this paper, the present situation and problems of marketing process in Korean agricultural environments were reviewed through a systematic methodology, and then we proposed a new business process for solving these problems by appling a supply chain management. We expect this supply chain management system applied to agricultural marketing process can improve significantly the rationality and transparency of Korean agricultural marketing structure.