• Journal of the Chungcheong Mathematical Society
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• v.8 no.1
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• pp.105-110
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• 1995

Suppose A is a local global ring (with many units) and $T{\subset}A$ is a preordering. Let $a_i{\in}A^*$, $i=1,2,{\cdots},n$ and $a{\in}({\sum}_{i=1}^{l-1}\;a_iT){\cap}A^*$. Then, for any integer l, 1 < l ${\leq}$ n, there exist $x{\in}({\sum}_{i=1}^{l-1}\;a_iT){\cap}A^*$ and $y{\in}({\sum}_{i=l}^n\;a_iT){\cap}A^*$ such that a=x+y.

• Journal of the Korean Operations Research and Management Science Society
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• v.19 no.1
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• pp.41-52
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• 1994

Imprecision of evaluation or lack of prior information about preference can be an obstacle for decision maker in representing his strict preference. Therefore, fuzziness of preference can take place, and in addition, intransitivity or incomparability of preference becomes the critical difficulty in making complete preorder of alternatives. In order to get better solution and to improve practical usufulness, MCDM should be established as a pseudo-criterion model that include fuzzy preference. In this paper, we suggest a pseudo-criterion model that can make complete preorder of alternatives by metric distance measure.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1993.10a
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• pp.63-65
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• 1993

전통적 의사결정 이론에 입각한 기존의 다기준 의사결정 모형은 명확하게 정의된 문제에 대해서 실함수로 표현된 사전의 선호정보에 의하여 모호함이 없이 확실한 선호의 판별을 산출하는 true-criterion 모형이다. 그러나 현실적인 의사결정 환경하에서 선호정보가 사전에 명확하게 하나의 실함수로 얻어지기는 매우 어렵다. 이는 곧 선호의 불확실성(fuzziness)이나 선호판별을 할 수 없는 비교불가능성(incomparability)등이 있을 수 있음을 의미한다. 1980년대 이후의 다기준의사결정 이론에 대한 연구는 불명확한 문제의 정형화나 선호의 불확실성을 인정하고, 이를 fuzzy 이론을 이용하여 모형의 설정에 반영하고 있다. 심지어는 선호관계의 비추이성(intransitivity)이나 비교불가능성까지도 인정하는 등 모형의 강건성(robustness)을 고려하는 연구가 활발하게 이루어지고 있다.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.12
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• pp.1163-1168
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• 2006

Manufacturing technology for the production of high value-added fine chemical products is emphasized and getting more attention as the diversified interests of customers and the demand of high quality products are getting bigger and bigger everyday. Thus, the development of advanced batch processes, which is the preferred and most appropriate way of producing these types of products, and the related technologies are becoming more important. Therefore, high-precision batch distillation is one of the important elements in the successful manufacturing of fine chemicals, and the importance of the process operation strategy with quality assurance cannot be overemphasized. Accordingly, proposing a process structure explanation and operation strategy of such processes including batch processes and batch distillation would be of great value. We investigate optimal operation strategy and production planning of multi-purpose plants consisting of batch processes and batch distillation for the manufacturing of fine chemical products. For the short-term scheduling of a sequential multi-purpose batch plant consisting of batch distillation under MPC and UIS policy, we proposed a MILP model based on a priori time slot allocation. Also, we consider that the waste product of being produced on batch distillation is recycled to the batch distillation unit for the saving of raw materials. The developed methodology will be especially useful for the design and optimal operations of multi-purpose and multiproduct plants that is suitable for fine chemical production.