• Journal of Korean Institute of Industrial Engineers
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• v.23 no.1
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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.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.11
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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.

• Journal of The Korean Association For Science Education
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• v.36 no.6
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• pp.867-876
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• 2016

In accordance with the changing of society, remarkable increase in knowledge and information, the competencies to choose and use proper information in various domains are considered as an important skill. As one of the methods in developing these competencies, it is emphasized that a problem-based learning can make student understand and use knowledge by solving the contextualized problem. However, it is skeptical of learner's development of competencies to use knowledge by solving well-defined given problem. Therefore it is required that students be allowed to develop the competency to find problem through experiences to determine and evaluate the purpose of the problem and method. The purpose of this study is to understand how undergraduate students use science or technology in finding a problem. In this line, this study articulated four cases conducted by participants who engaged in convergence teaching-learning program. And this study investigated the participants' process of problem-finding, method and reason to apply science or technology. The results were drawn by analyzing interviews and written data, including their proposal, a poster, and final reports. Participants changed the form of problem from initial ill-structured one into a concrete one, where the participant could derive a detailed solution. Science or technology applied as the detailed example to convert problem into a concrete form, or as the analyzing tool or theoretical background of problem to make a link with other domain. Their reason of applying science or technology could be summarized in 'personal interest based on prior experience' and 'alternatives to resolve a dissatisfaction.' Based on the result, this study suggests holistic approach that is included in both intuitive thinking and logical thinking and metacognitive regulation to stimulate problem-finding in problem-based learning program.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.1
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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.

• Journal of Korean Port Research
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• v.7 no.1
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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.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.19 no.40
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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.

• Korean Institute of Interior Design Journal
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• v.24 no.3
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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.

• Journal of Korean Library and Information Science Society
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• v.18
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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.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.04a
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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.

• Proceedings of the KIEE Conference
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• 2000.07d
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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.