• Rapid Communication in Photoscience
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• v.3 no.3
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• pp.42-47
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• 2014

Development of molecular and supramolecular systems showing efficient photoinduced energy or electron transfer are of current research interest due to their applications in various chemical and biological processes. Various polypyridine metal complexes including Ru(II), Ru(III), Os(II), Pt(II), Fe(II), Re(I), Ir(III) and so on as a metal center introduce for expanding some more understanding of molecular-scale photoelectronics. Their complexes are concisely classified by the types of relay ligands as follows; (a) metal-direct ligand-metal system; dinuclear or trinuclear systems, (b) metal-nonconjugated ligand-metal system and metal-nonconjugated ligand system having flexible/rigid ligand, (c) metal-conjugated ligand-metal system, and (d) conjugated ligand-metal-conjugated ligand system and metal-self assembly ligand-metal system. It is pointed out that the role played by the relay ligands is important in constructing the metal complexes.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.159-167
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• 2005

Considering the increase of interest in $H_{2}O_2$ as a rocket propellant, a test facility and a rocket engine have been developed to research in areas of $H_{2}O_2$ mono-propellant propulsion. A detailed design-study of a $H_{2}O_2$ mono-propellant rocket engine of 100-N thrust is presented. Several firings attempted in early stage had some problems with misfire and chamber pressure decrease. Low environmental temperature and impurities included in hydrogen peroxide were considered to be the reasons. Addressing these points resulted in successful firing of the rocket engine and obtained thrust about $100\sim107-N.$

• Proceedings of the Society of Korea Industrial and System Engineering Conference
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• 2002.05a
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• pp.119-124
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• 2002

Clustering of data is of a great interest in many data mining applications. In the field of document clustering, a document is represented as a data in a high dimensional space. Therefore, the document clustering can be accomplished with a general data clustering techniques. In this paper, we introduce a document clustering system based on similarity among documents. The developed system consists of three functions: 1) gatherings documents utilizing a search agent; 2) determining similarity coefficients between any two documents from term frequencies; 3) clustering documents with similarity coefficients. Especially, the document clustering is accomplished by a hybrid algorithm utilizing genetic and K-Means methods.

• Journal of Korean Institute of Industrial Engineers
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• v.14 no.1
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• pp.91-101
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• 1988

Break-even analysis is a simple and useful tool in decisions and planning activities though its use is somewhat limited to short-term analysis. The subject is discussed in the fields of engineering economics, production management, cost and managerial accounting, finance, marketing, and so on. Conventional break-even analysis suits the case of stable price and low interest rate. In this paper, we try to overcome the limit by considering following factors, namely, time value of money, depreciation, tax, and capital gains. Also, considering learning effect, we increase applicability to a new project which raises certain changes such as a replacement of production process, an employee turnover, etc. Thus, we suggest a model which has a dynamic break-even quantity per period for the project. Furthermore, we examine the effect of inflation in break-even analysis.

• Journal of the Korean Applied Science and Technology
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• v.15 no.3
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• pp.39-45
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• 1998

In recent years, there has been considerable interest in the development of new functional surfactant including new type of anionic surfactants. Anionic surfactants, ${\alpha}-sulfo$ fatty acids that straight long chain alkyl group having from 12 to 18 carbon atoms, were synthesized with sulfur trioxide-dioxane complex to good yield. Xylitol ${\alpha}-sulfo$ fatty acid esters were obtained by reaction that the acetification and esterification of xylitol, by addition reaction with sodium chloride and hydrolysis respectively. These compounds were a new group of destructible surfactants which readily hydrolyzed and oxidized in natural water reservoirs. Physical properties of these new compounds involved surface tension, critical micelle concentration(cmc), foaming power, emulsion power, and hydrolysis properties, were measured. The cmc values of the compounds by ring method were assumed to $7.0{\times}10^{-3}{\sim}3.0{\times}10^{-2}mol/{\ell}$ range and surface tensions at cmc were $25{\sim}31dyne/cm$ respectively.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.27 no.1
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• pp.38-46
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• 2004

To be successful in increasingly competitive Internet marketplace, it is essential to capture customer loyalty. This paper deals with an intelligent agent approach to incorporate customer's sensibility into an one-to-one recommendation service in on-line shopping mall. In this paper the focus of interest is on-line recommendation service algorithm for development of Human Sensibility based web agent system. The recommendation agent system composed of seven services including specialized algorithm. The on-line recommendation service algorithm use human sensibility ergonomics and on-line preference matching technologies to tailor to the customer the suggestion of goods and the description of store catalog. Customizing the system's behavior requires the parallel execution of several tasks during the interaction (e.g., identifying the customer's emotional preference and dynamically generating the pages of the store catalog). Most of the present shopping malls go through the catalog of goods, but the future shopping malls will have the form of intelligent shopping malls by applying the on-line recommendation service algorithm.

• Korean Journal of Child Studies
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• v.30 no.6
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• pp.323-336
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• 2009

There has been a significant increase in the number of divorced families during the past 10 years in Korea. Divorce imposes a great impact on their children as well as divorcees. As many as 1.41 million children under 20 years-old have experienced their parents' divorce in past 10 years. Children are faced with much difficulty in adjustment after the parental divorce. Issues of the research and policy on the divorced family are discussed in this study. For future studies, a longitudinal research model, father-custody and grandparent-custody families, custody parents's gender, a theoretical model for Korean divorced families should be considered. New legislations have been recently enacted to enhance children's well-being, but further efforts such as the involvement of child development specialists in the divorce process should be followed in the pursuit of the best interest of the children.

• International Commerce and Information Review
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• v.1 no.2
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• pp.295-323
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• 1999

A main purpose of this study is to examine the international mercantile custom of Russia. After the collapse of the Soviet Union, the new Russia have to make a relation external world for economic development. The geostrategic importance and natural resources in Russia attracted constant interest of western countries. There are many difficulties in this country and hundreds of Korean and western companies already operate in Russia and their activities are more and more of a long-tenn character. So, the settlements of trade and understanding between Korea and Russia are very important. It includes effective methods of trade settlement, factors of successful negotiation, differences of trade customs and business environment.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.11a
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• pp.527-530
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• 2005

센서 네트워크는 다수의 센서 노드들이 싱크(sink) 노드와 데이터 중심(Data centric) 기반으로 통신을 하게 되는데 이때 사용되는 라우팅 알고리즘 중 한 가지가 Directed Diffusion이다. Directed Diffusion 은 싱크(sink)의 named data 질의 방송(diffuse)에 기반을 둔 라우팅 프로토콜(protocol)로 다수의 소스 노드와 다수의 싱크 노드의 상황에서도 효율적으로 동작한다는 점과 각각의 질의에 의한 라우팅 경로 중에 aggregation 과 caching을 수행할 수 있다는 장점을 갖는다. 그러나 강화된 gradient 패스를 얻기 위해 요구되는 부담이 크다는 단점을 갖는다. 따라서 본 연구에서는 interest 패킷에 hop-count를 도입하여 gradient가 과다하게 설정되는 것을 제한함으로써 에너지 사용 효율을 높일 수 있는 개선된 Directed Diffusion 알고리즘을 제시한다. 또한 시뮬레이션을 통해 제안된 알고리즘의 유용성 확인을 확인하고자 한다.

• Journal of The Korean Association For Science Education
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• v.12 no.3
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• pp.119-128
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• 1992

The contents of two elementary science textbooks are analyzed; they are HBJ Science and Holt Science. A) The ratio of the contents is as follows physics area, 21-27% ; chemistry area, 6-7% ; biology area, 32-41% ; earth science area, '27-31 %. B) The jobs related in science and technology are introudced in both textbooks. The kinds of jobs found in Holt Science and HBJ Science are 94 and 55, respectively. C) There cent developments in science and technology are introduced in Holt Science and HBJ Science are 57 and 46 times respectively. The introductoin of the recent development of science & technology and the jobs relcated in science & technology may interest children in science.