• 한국자동차공학회논문집
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• 제17권1호
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• pp.169-175
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• 2009

Real-time multibody vehicle dynamics software has been developed for virtual handling tests. The software can be utilized for HILS(Hardware In the Loop Simulations) and consists of three modules such as a graphical vehicle modeling preprocessor, a real time dynamics solver, and a virtual reality graphic postprocessor for virtual handling tests. In the graphical vehicle modeling preprocessor, vehicle hard point data for a suspension model are automatically converted into multibody vehicle model. In the real time dynamics solver, the efficient subsystem synthesis method is used to create multibody equations of motion for a subsystem by a subsystem. In the virtual reality graphic postprocessor, an animator has been also developed by using Matlab Virtual Reality Toolbox for virtual handling tests.

• 농촌의학ㆍ지역보건
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• 제23권2호
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• pp.295-303
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• 1998

Toxocariasis is a parasitic zoonosis caused by infestation of humans with larvae of Toxocara canis, the common roundworm in dogs. Two syndromes have been identified : visceral larva migrans and ocular toxocariasis. In this study we were characterized proteinase activity in crude extracts from liver, lung, kidney and heart of mice infected with Toxocara canis and the dynamics of their changes in different stages of disease. The optimal pH was 5.5. In liver of mice infected with Toxocara canis, the maximun activity of proteinase was observed in 5 day post infection. In lung, the activity reached its maximun on 5th day in A group (infected with 100 embryonated eggs), and on 5th week in B group (infected with 50 embryonated eggs). In kidney, the maximum activity was shown at 6th week in A group, and in B group was shown at 10th day. In early infection, the activity reached its maximun in heart of mice infected with Toxocara canis. As we could see, the dynamics of the changes of proteinase activity in mice is similar in the case of the disease with other biochemical and immunological indices observed in toxocariasis.

• Management Science and Financial Engineering
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• 제10권1호
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• pp.1-23
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• 2004

The changing structure of organization and the increasing diversity of business have forced organizations to have abilities to coordinate dispersed business activities. They have required cooperation and coordination among the functional units in the organization which should involve group decision-making processes. Although many group decision-making support tools and methods have been introduced to enable the collaborative process of group decision-making, they often lack the features supporting the dynamic complexity issue frequently occurring at group decision-making processes. This results in cognitive unfit between the group decision-making tasks and their supporting tools, bringing about mixed results in their effects on group decision-making. This study proposes system dynamics modeling as a group decision-making support tool to deal with the group decision -making tasks having properties of dynamic complexity in terms of cognitive fit theory.

• Carbon letters
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• 제11권4호
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• pp.316-324
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• 2010

The effects of geometrical parameters on mechanical properties of graphite-vinylester nanocomposites and their constituents (matrix, reinforcement and interface) are studied using molecular dynamics (MD) simulations. Young's modulii of 1.3 TPa and 1.16 TPa are obtained for graphene layer and for graphite layers respectively. Interfacial shear strength resulting from the molecular dynamic (MD) simulations for graphene-vinylester is found to be 256 MPa compared to 126 MPa for graphitevinylester. MD simulations prove that exfoliation improves mechanical properties of graphite nanoplatelet vinylester nanocomposites. Also, the effects of bromination on the mechanical properties of vinylester and interfacial strength of the graphene.brominated vinylester nanocomposites are investigated. MD simulation revealed that, although there is minimal effect of bromination on mechanical properties of pure vinylester, bromination tends to enhance interfacial shear strength between graphite-brominated vinylester/graphene-brominated vinylester in a considerable magnitude.

• 대한수학회지
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• 제56권1호
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• pp.39-52
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• 2019

The aim of this paper is to introduce the notions of (quasi) weakly almost periodic point, measure center and minimal center of attraction of amenable group actions, explore the connections of levels of the orbit's topological structure of (quasi) weakly almost periodic points and study chaotic dynamics of transitive systems with full measure centers. Actually, we showed that weakly almost periodic points and quasiweakly almost periodic points have distinct orbit's topological structure and proved that there exists at least countable Li-Yorke pairs if the system contains a proper (quasi) weakly almost periodic point and that a transitive but not minimal system with a full measure center is strongly ergodically chaotic.

• 가정과삶의질연구
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• 제20권4호
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• pp.189-196
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• 2002

The purpose of this study is to investigate the effects of factors of family leisures on family intra-system dynamics and quality of family life. A total 309 questionnaires was analyzed from married men and women of school-age families. Factors of family leisures were classified in 'education oriented', 'hobby oriented', social oriented'and 'family oriented'in the study ahead.(Refer to Journal of korean Home Management association Vol. 19(2).) The major results of this research were as follows. First, family intra-system dynamics was classified 'individual progress', 'sentimental stability','interaction'and 'management efficiency'. Second, the group that participated more in 'social oriented'and less in 'family oriented'activities had higher level of 'individual progress'. The group that participated less in 'social oriented'and more in 'education oriented'activities had higher level of 'sentimental stability'The group that participated more in 'education oriented'activities had higher level of 'interaction'and 'management efficiency '. Based on the results as above, we suggest people need to overcome 'a mental panic'through the family leisure. And we need to develop concern with family leisure as a practical loaming.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2008년도 Asian Magnetics Conference
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• pp.101.2-101.2
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• 2008

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2011년도 한국컴퓨터종합학술대회논문집 Vol.38 No.1(A)
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• pp.316-319
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• 2011

그룹 키 협정 (Group key agreement)1)은 그룹 내의 노드 (member)가 하나의 비밀 키 (secret key)를 공유하도록 하는 프로토콜이다. 이 때, 그룹 키를 맺는 시간을 줄이기 위해 메시지의 수, 지수연산, 라운드 수가 적을수록 좋다. 그렇기 때문에 기존의 연구들에서는 이러한 요소들을 고려하여 프로토콜을 구성하였다. 하지만 그룹 내의 노드들이 계속 머무르는 상태에서 똑같은 그룹을 형성하는 것이 아니라 중간에 어떤 노드가 그룹을 떠나는 경우 (leave)도 있고 새로운 노드가 들어오는 경우 (join)도 있다. 또한, 그룹이 빠지는 경우 (group leave)도 있고, 그룹이 들어오는 경우 (group join)도 있다(Group Dynamics). 이러한 시나리오는 충분히 발생할 수 있기 때문에 이러한 요소들도 고려하여 프로토콜을 구성해야 한다. 그래서 이논문에서는 그룹 노드들의 join과 leave, 그룹들 간의 join, leave가 빈번한 경우도 고려하여 프로토콜을 제시할 것이다.

• 한국시스템다이내믹스연구
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• 제9권1호
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• pp.57-71
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• 2008

This research paper describes a complex and vague settings in which organization makes a decision and explains a role of decision maker's learning process. The original paper, written by Cohen, March, Olsen in 1972, said that all members of organization depended on the technology taken through trials and errors, which is the 'learning' process literally. But they intended to exclude the learning process in their simulation model because their PORTRAN model couldn't replicate the learning concept. As a result, they couldn't explain how all agents of garbage can simulation model resolve the problem dynamically. To overcome this original paper's limitations, we try to rebuild a learning process simulation model using by system dynamics approach that can capture the linkage between organization leanings and agents-based decision-makings. Our learning simulation results reveal two points. First, decision maker's leanings process improves the efficiency of decision making in complex situation. Second, group learning shows a superior efficiency to an individual learning because group members share organizational memory and energy.

• Journal of Microbiology and Biotechnology
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• 제19권9호
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• pp.1028-1033
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• 2009

In this study, the dynamics of living cells (LC) and dead cells (DC) in a laboratory-scale biofilm membrane bioreactor for waste gas treatment was examined. Toluene was used as a model pollutant. The bacterial cells were enumerated as fluoromicroscopic counts during a 140 operating day period using BacLight nucleic acid staining in combination with epifluorescence and confocal laser scanning microscopy (CSLM). Overall, five different phases could be distinguished during the biofilm development: (A) cell attachment, (B) pollutant limitation, (C) biofilm establishment and colonization, (D) colonized biofilm, and (E) biofilm erosion. The bioreactor was operated under different conditions by applying different pollutant concentrations. An optimum toluene removal of 89% was observed at a loading rate of 14.4 kg $m^{-3}d^{-1}$. A direct correlation between the biodegradation rate of the reactor and the dynamics of biofilm development could be demonstrated. This study shows the first description of biofilm development during gaseous toluene degradation in MBR.