• International journal of advanced smart convergence
• /
• v.6 no.3
• /
• pp.22-28
• /
• 2017

With the recent development of technologies to manage vast amounts of data, data mining technology has had a major impact on all industries.. Data mining is the process of discovering useful correlations hidden in data, extracting executable information for the future, and using it for decision making. In other words, it is a core process of Knowledge Discovery in data base(KDD) that transforms input data and derives useful information. It extracts information that we did not know until now from a large data base. In the decision tree, c4.5 algorithm was used. In addition, the C4.5 algorithm was used in the decision tree to analyze the difference between frequency and mortality in the region. In this paper, the frequency and mortality of percutaneous coronary intervention for patients with heart disease were divided into regions.

• Proceedings of the KSME Conference
• /
• 2003.04a
• /
• pp.1730-1735
• /
• 2003

The plume-induced shock wave is a complex phenomenon, consisting of plume-induced boundary layer separation, separated shear layer, multiple shock waves, and their interactions. The knowledge base of plume interference effect on powered missiles and flight vehicles is not yet adequate to get an overall insight of the flow physics. Computational studies are performed to better understand the flow physics of the plume-induced shock and separation particularly at high plume to exit pressure ratio. Test model configurations are a simplified missile model and two rounded and porous afterbodies to simulate moderately and highly underexpanded exhaust plumes at the transonic/supersonic speeds. The result shows that the rounded afterbody and porous wall attached at the missile base can alleviate the plume-induced shock wave phenomenon, and improve the control of the missile body.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2017.01a
• /
• pp.163-166
• /
• 2017

본 논문에서는 학생들에게 자신의 진로결정에 도움이 될 수 있는 비교과 및 교과 정보 제공 시스템을 제안한다. 이는 교수들의 학생 수강지도에 활용되어 정확한 진로 지도에 도움을 줄 수 있다. 이러한 시스템을 구현하기 위하여, 온톨로지 기반 지식베이스를 구축한다. 온톨로지 지식베이스는 강의, 역량, 능력단위, 직무, 기업 정보로 구성이 되어있으며 유지보수가 쉬운 구조로 설계하였다. 또한 온톨로지 지식베이스가 가진 정보로 새로운 지식들을 추론한다. 이 추론 결과를 웹 인터페이스를 활용해, 사용자가 개념들 간의 관계를 파악하고 자신에게 맞는 과목 및 직무를 추천받을 수 있도록 한다.

• Proceedings of the KIEE Conference
• /
• 2002.11c
• /
• pp.521-524
• /
• 2002

This paper deals with the rule generation from data for control system and data mining using rough set. If the cores and reducts are searched for without consideration of the frequency of data belonging to the same equivalent class, the unnecessary attributes may not be discarded, and the resultant rules don't represent well the characteristics of the data. To improve this, we handle the inconsistent data with a probability measure defined by support, As a result the effect of uncertainty in knowledge reduction can be reduced to some extent. Also we construct the rule base in a hierarchical structure by applying core as the classification criteria at each level. If more than one core exist, the coverage degree is used to select an appropriate one among then to increase the classification rate. The proposed method gives more proper and effective rule base in compatibility and size. For some data mining example the simulations are performed to show the effectiveness of the proposed method.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.4 no.2
• /
• pp.205-210
• /
• 2004

This paper deals with rule extraction from data using rough set theory. We construct the rule base in a hierarchical granulation structure by applying core as a classification criteria at each level. When more than one core exist, the coverage is used for the selection of an appropriate one among them to increase the classification rate and accuracy. In Addition, a probabilistic approach is suggested so that the partially useful information included in inconsistent data can be contributed to knowledge reduction in order to decrease the effect of the uncertainty or vagueness of data. As a result, the proposed method yields more proper and efficient rule base in compatability and size. The simulation result shows that it gives a good performance in spite of very simple rules and short conditionals.

• Journal of the Korean Society for Precision Engineering
• /
• v.8 no.3
• /
• pp.27-43
• /
• 1991

연소 가공은 고품질 고정도를 필요로 하는 경우 매우 유효한 가공방법이지만 그 공정이 많은 Parameter에 의해 구성되기 때문에 동일한 조건에서도 정량적인 평가가 어려우므로 작업현장 에서는 과학적 원리와 공학적 지식 보다는 숙련자의 경험과 기능에 의존하고 있는 실정이다. 본 연구에서는 이와 같은 국면에 대처한 문제 해결을 위해 Computer가 인간사고에 근접 할 수 있도록 Fuzzy 이론과 Default 이론을 도입하고 전문가의 이론적 지식과 숙련자의 감각적 지식을 적극 수용 하여 연소용 Expert system (최적 가공 조건의 설정 System과 Trouble shooting system)을 개발하였다. 또한 연소 가공 Data의 불확실한 애매성을 효과적으로 이용 할 수 있도록 Fuzzy 가능성이론에 의해 가공 Datad을 회귀 분석하여 실가공 Data base에 축적시켜 재활용토록 설계하었으며 개발된 본 System 의 실행 결과 그 활용성이 높음을 입증하였다.

• Korean Journal of Computational Design and Engineering
• /
• v.3 no.3
• /
• pp.168-176
• /
• 1998

This paper deals with an application on the mould machining of air intake hose product by using 3-dimensional parametric modeling techniques. The detailed domain is the 3-dimensional product with similar shapes and different sizes which needs too much working time for preparation of modeling or machining due to making a trial and errors repeatedly. Decision making rules for selection of modeling order and technique, and for calculation of cutting conditions, and for determination of sequence and method concerning machining operations are required by interview of expert engineers in the field. The developed expert system of modeling and machining is programmed by using a user programming language under the CAD/CAM software of the Personal Designer. The developed system that aids a mould engineer who is working in the modeling and machining section which deal with air intake hose product provides strong and useful capabilities.

• The Korean Journal of Ecology
• /
• v.26 no.2
• /
• pp.53-58
• /
• 2003

Ever-growing recreation, tourism and ecotourism worldwide have become a significant factor of resource degradation in many protected areas. Managers of these areas are increasingly challenged to implement policies, strategies and actions that would protect the resource base while providing quality visitor experience. One major issue in managing protected area visitations is that of carrying capacity, or the question of "how much use is too much\ulcorner". Scientific studies of visitor impacts, often known as recreation ecology, has generated a knowledge base that provides valuable input to the visitor carrying capacity management process adopted by the U.S. National Park Service. This paper aims at (a) providing an overview of recreation ecology research and its application in managing visitor carrying capacity, and (b) examining the relevance of recreation ecology to East Asian protected areas with special reference to the visitor capacity issue.ity issue.

• Journal of the Korean Society of Safety
• /
• v.7 no.1
• /
• pp.31-38
• /
• 1992

This paper presents a study on application of expert system technique for the diagnosis of fire-causes in plants. A need is recognized for new methods to diagnose exactly the causes of fires without the help of the human experts. To cope with the difficulty, the expert system techiuque is applied to this area. The expert system suggested in this paper is developed to infer the causes of fires(or, ignition source ) by using the information drawn from the circumstances in fire. For the convenience of inference, ignition sources we classified into eight types ; elecoic spark, adiabatic compression, welding spark, material of high temperature, impact and friction, spontaneous ignition, naked fire, and static electricity. The knowledge base is composed of the rule base and dynamic database, which contain the rules and facts obtained by the expenence in this area, respectively. Both depth-first search and backward chaining schemes are used in reasoning process. This expert system is written in an artificial intelligence language "PROLOG", and its availability is demonstrated through the case study.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2002.10a
• /
• pp.141-146
• /
• 2002

Real-time monitoring and control of the cutting force is essential for unmanned cutting process. Although the cutting force can be measured directly using tool dynamometers, their implementation is not feasible in industry due to high cost. Alternative approach is the cutting force estimation based on spindle drive models, but it requires the knowledge of their characteristics with the spindle speed variation. This paper investigates the power-factor and frictional characteristics of three-phase induction motors and determines its characteristics below and above the base speed, respectively. In order to realize the proposed cutting force monitoring system, a stand-alone DSP board was utilized. Its monitoring and control performance is evaluated in a CNC lathe.