• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.5
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• pp.373-378
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• 2001

The optimization method based on an enhanced genetic algorithms is for multimodal function optimization in this paper. This method is consisted of two main steps. The first step is a global search step using the genetic algorithm(GA) and function assurance criterion(FAC). The belonging of an population to initial solution group is decided according to the FAC. The second step is to decide the similarity between individuals, and to research the optimum solutions by single point method in reconstructive search space. Four numerical examples are also presented in this papers to comparing with conventional methods.

• The Korea Journal of Herbology
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• v.27 no.2
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• pp.31-36
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• 2012

Objective : For the purpose of making use the wild edible plants of Ulleung island smoothly, this study was designed. Method : For the first time, I searched the wild edible plants of Ulleung island from various data. And I examined herbological books and research papers on the wild edible plants of Ulleung island. Result : The herbaceous plants in Ulleung island were 12 family and 22 species, Compositae and Liliaceae plants take the highest number of them. The woody plants in Ulleung island were 1 family(Araliaceae) and 2 species. The herbal medicines that originated from the wild edible greens of Ulleung island were 25 species. The herbal medicines that have the effects of clearing away heat(淸熱), eliminating toxin(解毒), subduing swelling(消腫) and promoting blood circulation to remove blood stasis(活血祛瘀) take the highest number of the effects of these herbal medicines. Conclusion : For the purpose of making use the wild edible plants of Ulleung island smoothly, we should recognize not only medical benefits but also matters that pay special attention.

• Proceedings of the KIEE Conference
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• 2001.05a
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• pp.201-205
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• 2001

This paper presents the load modeling process and bus load models for KEPCO power system. At first, load devices commonly used in KEPCO power systems were selected, and tested for measuring the voltage and frequency sensitivity of active and reactive power. From this test, about 40 voltage and frequency dependent load models have been obtained. The bus load composition rate for KEPCO power system has been determined using the various recent surveys and papers in order to develop the load model for a power system bus. To verify the accuracy of developed bus load models, the field test for measuring active and reactive power according to artificial variation of the bus voltage was performed at 8 substations for spring summer, autumn, winter cases. With data of this seasonal field test, more reliable bus load models for KEPCO power systems were developed.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.6
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• pp.1520-1534
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• 1994

A new analytical method for the prediction of the buckling behavior of laminated plates consisting of layers having different properties in tension and compression, so called bimodulus, is proposed in this paper. Buckling analysis of bimodular composite laminated paltes are performed with the results reduced from plate bending analysis. The governing equations of bimodular plates are based on the first shear deformation theory. As a case study, bending and buckling of simply supported, multilayered, symmetric, antisymmtric, and specially orthotropic laminates under uniformly distributed lateral load for bending analysis and in-plane load for buckling are considered. The results of the bending analysis are compared with the previous papers. Then, the fundamental critical buckling loads and buckling modes are calculated for the various bimodular composite rectangular thin plates.

• Journal of the Korean School Mathematics Society
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• v.5 no.1
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• pp.13-19
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• 2002

In this experiment we emphasized the cooperative small group learning and the members of my group worked together to succeed and communicate their mathematics ideas freely. The researcher(teacher) became an observer and facilitator of small group interaction, paying attention to the ongoing learning process, Sometimes the researcher suggested some investigation approach(or discovery)being written by computer software or papers. In this experiment we provided 6 activities as follows : (1) changing the conditions in given problem. (2) operating the meaningful heuristics with the problem sets. (3) creating the problem situations related to understanding (4) creating the Modeling situations. (5) creating the problem related to combinatorial thinking in real world. (6) posing some real problem from real world. we could observed several conjectures First, Attitude and chility to interpret the problem setting is highly important to pose the problem effectively. Second, Generating the understanding can be a great tool to pose the problem effectively. Third, Sometimes inquiry approach represented by software or programmed book could be some motivation to enhance the posing activities. Forth, The various posing activities relate to one concept could give the students some opportunity to be adaptable and flexible in the their approach to unfamiliar problem sets.

• Research in Mathematical Education
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• v.8 no.2
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• pp.69-80
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• 2004

It is undeniable that teachers play the principal roles in education. This is why education and professional development of teachers are so important. Some of recent works have made this fact clearer. In America, in particular, many reports and research papers have recently been published on these problems. In this paper, we first introduce briefly the current system of education, employment, and professional development of mathematics teachers in Korea. And then we mention a research project on education of mathematics teachers. The final report of the project contains some suggestions for curriculums of the department for education of mathematics teachers. We describe one example of extended syllabus which implements those suggestions. The example is on Modern Algebra I.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.10
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• pp.137-146
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• 2004

This is the second of two companion papers concerned with the analysis and design of a pneumatic vibration isolation system. The properties of the system are clarified by observation of the transmissibility surface calculated by the models and algorithm developed in the first paper of this research. It Is shown that the nonlinear model proposed in this research is more closer to experimental results than the linear model that have been used in previous studies. The design optimization of the major design variables that affect the performance of the system is achieved by using the condition for attenuation, disturbance rejection and maximum damping in resonance peak. The design space search method is adopted for the optimization of the orifice area. The models, transmissibility calculation algorithms and design optimization techniques developed in this research are shown to be greatly helpful to the optimal design of the pneumatic vibration isolation system by experiment.

• Proceedings of the Korean Society for Quality Management Conference
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• 2010.04a
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• pp.16-23
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• 2010

This research analyzed about inconsistence and cause of the audit result on national defense quality management system in certification company. Direction of research analyzes corelation with distribution by items at national defense quality management system standard by Investigated number and occurrence of examination report slight and critical incongruity on 2008 and 2009. Study finding slight and critical incongruity happened to first examination average 10.2 items, renewal examination average 7.0 items. By incongruity occurrence appeared high in item that there are a lot of examination item shares of standard requirement, it was studied by correlative thing between the examination with standard. Factor of incongruity occurrence was proved to comprehension insufficiency for quality management system, quality procedure insufficiency, didn't fulfil proceedings, business was unripe. In this papers, we contribute to propose direction for improvement of national defense quality management system comprehensive faculty elevation and national defense quality certification in this treatise.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.583-589
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• 2001

For several decades many researchers have studied various algorithms, known as non-destructive testing, to identify abnormalities within a structure. Damage detection technique using vibration signal is a kind of these methods. Many researchers have published lots of papers dealing vibration signal to identify structural damage. All the methods for damage detection using vibration signal can be divided into two big categories. The first category is the method that requires some reference model such as finite element model, and the second is the method that does not require any reference model but needs only experimental data. This paper will be devoted to classify damage detection methods that utilize vibration signal.

• Journal of KSNVE
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• v.6 no.4
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• pp.447-456
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• 1996

Dynamic characteristics of the bell-type structure including acoustic effects and transient dynamic problems were analyzed numerically. Natural frequencies, mode shapes and transient dynamic analysis used the finite element method with 3-D general shell element. Mode shapes and stress distributions of transient dynamic analysis were expressed by computer graphics. The method using this study was evaluated by comparision of theoretical results at reference papers(14), (15) and the experimental test using Fast Fourier Transform analyzer. Vibrational modes governing acoustic characteristics of the typical bell-type structure depended on the first flexural mode(4-0 mode) and the second flexural mode(6-0 mode). Asymmetric effects by Dangiwas, acoustic holes gave rise to beat frequencies, and the Dangjwa was found to be most effective. When impact load acted on the bell, stress concentration occured at the rim part of bell. It was found that the bell type structure should be designed thickly at the rim part in order to prevent impact load from stress concentration.