• 대한산업공학회지
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• 제23권1호
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• pp.39-54
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• 1997

This paper presents four process models for machining processes : 1) an economical mathematical model of machining process, 2) a prediction model for surface roughness, 3) a decision model for fuzzy cutting conditions, and 4) a judgment model of machinability with automatic selection of cutting conditions. Each model was developed the economic machining, and these models were applied to theories widely studied in industrial engineering which are nonlinear programming, computer simulation, fuzzy theory, and neural networks. The results of this paper emphasize the human oriented domain of a nonlinear programming problem. From a viewpoint of the decision maker, fuzzy nonlinear programming modeling seems to be apparently more flexible, more acceptable, and more reliable for uncertain, ill-defined, and vague problem situations.

• 제어로봇시스템학회논문지
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• 제8권11호
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• pp.970-975
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• 2002

We suggests an effective method to construct time-varying C-obstacles in the 3-dimensional configuration space (C-space) using free arc. The concept of free arc was defined mathematically and the procedure to find free arc in the case off-dimensional C-space was derived in [1]. We showed that time-varying C-obstacles can be constructed efficiently using this concept, and presented simulation results for two SCARA robot manipulators to verify the efficacy of the proposed approach. In this paper, extensions of this approach to the 3-dimensional C-space is introduced since nearly all industrial manipulators are reasonably treated ill the too or three dimensional C-space f3r collision avoidance problem The free arc concept is summarized briefly and the method to find lice arc in the 3-dimensional f-space is explained. To show that this approach enables us to solve a practical collision avoidance problem simulation results f3r two PUMA robot manipulators are presented.

• 한국과학교육학회지
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• 제36권6호
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• pp.867-876
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• 2016

지식과 정보의 양이 폭발적으로 증가하는 최근 사회의 변화에 의해 지식의 선택과 활용 능력을 신장해야 한다는 요구가 더 높아지고 있다. 이를 반영하기 위한 하나의 방안으로 문제기반학습은 구체적 맥락에서 문제를 해결하여 지식의 이해와 활용을 가능하게 하는 접근 방안임을 강조했다. 하지만, 주어진 문제를 해결하는 경험만으로는 본래의 목표를 달성하기 어렵다는 비판이 많은 것이 사실이다. 따라서 학생들이 주어진 상황으로부터 문제 해결을 위한 구체적 목표와 방법을 결정하는 경험을 쌓게 하여 문제를 발견하는 능력을 강조해야 한다. 본 연구는 대학생들이 과학기술 분야를 어떻게 활용하여 문제를 발견하는지 이해하고자 하였다. 이러한 선상에서 융합형 교수학습프로그램에 참여한 대학생들 중, 과학기술 분야를 활용한 네 명의 참여자들의 사례에서 문제발견 과정과 과학기술 분야의 활용 방식, 활용 이유를 조사하였다. 연구결과는 문제 제안서, 중간발표인 포스터, 최종 보고서와 함께 인터뷰 자료를 분석하여 도출하였다. 연구결과, 연구 참여자들은 초기의 비구조화된 문제로부터 구조화하여 결론을 구체적으로 도출할 수 있는 형태로 변화시켰다. 과학기술 분야는 문제의 구조화를 위한 구체적 사례로 활용되거나, 타 학문 분야와 연계하기 위한 분석 도구 혹은 배경 이론으로 활용되는 것을 확인하였다. 과학기술 분야가 도입된 이유는 사전 경험에 근거한 개인적 흥미와 불만족 해소를 위한 기존 학문 분야의 대안으로 설명할 수 있었다. 연구 결과를 토대로 문제기반학습에서 문제발견을 촉진할 수 있는 방안으로 직관적 사고와 논리적 사고의 통합적 관점, 메타인지적 조절을 제안하였다.

• 동의생리병리학회지
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• 제22권1호
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• pp.256-261
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• 2008

Anorexia is a common symptom in the elderly patients. Causes of anorexia in the elderly are very diverse and multifactorial. Causes include physiological changes associated with aging, mental disorders such as depression, anorexia tardive, dementia, medical diseases such as cancer(lung and gastrointestinal cancer), benign gastrointestinal disorders, cardiac disorders, pulmonary disease, thyroid disorders, infection. Medications such as digoxin, theophylline have also been implicated in the problem. No cause is found in about one quarter of patients. Management is directing at treating causes and providing nutritional support. In Oriental medicine, the appetite has close relation to Biwi. The main cause of anorexia is the insufficiency of Biwi. The physiology of Biwi is that Bi sends clarity(food essence) upward and Wi sends digested food downward. Specially if the physiologic function of Wi is disordered by various factors, Wi cannot send digested food downward. As a result, the anorexia can present by the disorder of Wi function. We experienced a case of an 74 years old female patient with ill-defined severe anorexia differentiated as Wijoongheohan. The patient was managed with fluid therapy and Jeonghyangsiche-tang. The anorexia and other symptoms improved continuously during hospitalization.

• 한국항만학회지
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• 제7권1호
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• pp.13-24
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• 1993

The rapid progress of the intermodal freight transportation in recent years has induced fierce competition among the adjacent hub ports for container transport. This brings increased attention to the evaluation of the port competitive ability. But it is not easy to evaluate the port competitive ability because this belongs to ill-defined system which is composed of ambiguous interacting attributes. Paying attention to this point, this paper deals the competitive ability of container port in Far-East Asia by fuzzy integral evaluation which is adequate to interacting ambiguous attribute problem. For this, the proposed fuzzy evaluation algorithm is applied to the real problem, based on the factors such as cargo volumes, costs, services, infrastructure and geographical sites These are extracted from the precedent study of port competitive ability, etc. The results show that the port evaluation factors come in following order ; services, costs, infrastructure, geographical sites and cargo volumes. There are some interactions(interaction coefficient, ${\lambda}=-0.664$ between evaluation attributes. The port competitive ability comes in following order : Singapore, Hongkong, Kobe, Kaoshiung and Busan. According to the sensitivity analysis, the rank between Busan and Kaoshiung changes when ${\lambda}=0.7$. From the analysis of the results, we confirmed that the proposed fuzzy evaluation algorithm is very effective in the complex-fuzzy problem which is composed of hierarchical structure with interacting attributes.

• 산업경영시스템학회지
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• 제19권40호
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• pp.15-22
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• 1996

Methods to find an optimal solution that is the function of the design variables satisfying all constraints have been studied, there are still many difficulties to apply them to optimal design problems. A method to solve the above difficulties is developed by using Genetic Algorithms. but, several problems that conventional GAs are ill defined are application of penalty function that can be adapted to transform a constrained optimization problem into an unconstrained one and premature convergence of solution. Thus, we developed an modified GAs to solve this problems, and two examples are given to demonstrate the effectiveness of the methodology developed in this paper.

• 한국실내디자인학회논문집
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• 제24권3호
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• pp.30-37
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• 2015

The target of design is a harmony between Beauty and Usefulness. Design is a result from representation of visual language by designer's creative thinking system. also, As an ill-defined problem cannot be described completely. and subjectively interpret depend on the situation, it is very difficult to present a theoretical standard. There have been many Design Sciences researches in recent years. such as Rule Based Design, Parametric Design, Replacement Design, Analogy Design, Metaphor Design, Genetic Algorithm. but Objective research is still unsatisfactory condition to investigate true nature about Design. At this point, It is very important to formulating about meaning of Design Language and Thinking. This study will define about that, and based on this definition, Lay out a logical basis for Treatment design variable and materialization of process by "Elements", "Relationship", "Schema". ultimately it look forward to provide a framework and minimize the complexity about Design Thinking.

• 한국도서관정보학회지
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• 제18권
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• pp.245-268
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• 1991

Some conclusions derived from the study are as follows : 1) Most conventional information retrieval systems require users do precisely that specify the information they require, but user's information needs are not always precise. 2) Information need arise from when users are in an anomalous stats of knowledge about some problem, so user's information needs are not always precise. 3) Information retrieval systems must assist to users make themselves correct, complement, and specify their information need. When information need arise, systems should understand the state of knowledge and will be design to present and specify their ill-defined potential information need. 4) Existing information retrieval techniques need a tool to complement current its disadvantages and to enhance retrieval efficiency. Browsing searching will be a role such as a tool. 5) Browsing searching can understand user's state of knowledge and assist to specify not only pre-searching information need but also changed information need during searching progress.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 봄 학술발표회 논문집
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• pp.199-209
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• 1998

Since most engineering problems have had open-ended and ill-defined characteristics, design process is in advance attended with determination of alternatives based on realistic constraints after definition of appropriate problem. And it is completed with selection of best alternative through their comparison and investigation, and with performance of selected-alternative's detail design. As the process of structural design compared with that of general design, this paper presents a paradigm which can generate structural design alternatives, select optimum structure among them and simultaneously set its optimum design variables in reference of several objective as a result in more extended design region. For this purpose, specialized genetic algorithms which can handle design alternatives and multicriteria problems is used.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2311-2313
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• 2000

In this paper, we consider $H^{\infty}$ optimal Kalman filter problems for linear weakly coupled stochastic systems. We introduce a decomposition for the systems of the Hamiltonian form, which plays an important role of exclusion of ill-condition by ${\varepsilon}$-effect and the parallel computation possibility. It is shown that the algebraic Riccati equation of the weakly coupled $H^{\infty}$ optimal Kalman filter problem is decoupled into completely independent reduced-order, well-defined, two suboptimal Kalman filters.