• 경영과학
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• 제31권3호
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• pp.113-130
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• 2014

Cooperative coevolutionary algorithm (CCEA) has proven to be a very powerful means of solving optimization problems through problem decomposition. CCEA implies the use of several populations, each population having the aim of finding a partial solution for a component of the considered problem. Populations evolve separately and they interact only when individuals are evaluated. Interactions are made to obtain complete solutions by combining partial solutions, or collaborators, from each of the populations. In this respect, we can think of various interaction modes. The goal of this research is to develop a CCEA for a supply chain network design (SCND) problem and identify which interaction mode gives the best performance for this problem. We present general design principle of CCEA for the SCND problem, which require several co-evolving populations. We classify these populations into two groups and classify the collaborator selection scheme into two types, the random-based one and the best fitness-based one. By combining both two groups of population and two types of collaborator selection schemes, we consider four possible interaction modes. We also consider two modes of updating populations, the sequential mode and the parallel mode. Therefore, by combining both four possible interaction modes and two modes of updating populations, we investigate seven possible solution algorithms. Experiments for each of these solution algorithms are conducted on a few test problems. The results show that the mode of the best fitness-based collaborator applied to both groups of populations combined with the sequential update mode outperforms the other modes for all the test problems.

• 한국과학교육학회지
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• 제26권7호
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• pp.843-855
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• 2006

본 연구는 지구과학 탐구활동에서 그룹의 상호작용 양식에 따라 학생들의 반성적 탐구는 어떤 특징을 보이는지를 알아보고, 수업의 3가지 맥락들은 반성적 탐구활동에서 어떻게 관련되는지를 알아봄으로써 학생들의 반성적 탐구의 실제를 이해하고 반성적 탐구를 촉진하기 위한 탐구활동 수업의 시사점을 얻고자 하였다. 이를 위해 고등학교 1학년 1개 학급을 선정해서 본 연구에서 개발한 반성적 탐구활동수업을 실시하고 수업을 녹화 전사해서 언어행동분석틀과 수업상황의 3가지 맥락으로 분석하였다. 사전 검사를 통해 알아낸 학습자 특성을 기초로 그룹을 나누어 수업을 실시하였으며 면담을 실시하여 수업분석에 참고하였다. 반성적 탐구활동수업에서 그룹 상호작용양식에 따른 반성적 탐구의 차이는 조화적 상호작용양식을 보이는 그룹에서는 전개와 정리단계에서 자료와 과제맥락이 연결된 반성적 탐구가 자주 나타난 반면, 대립적 상호작용양식 그룹에서는 자료맥락과 연결된 반성적 탐구가 아주 드물고 반성적 탐구척도 값도 2 배 이상 낮게 나타났다. 즉 조화적 그룹이 양적으로 더 많은 반성적 탐구진술을 했으며 자료맥락과 과제맥락을 연결하는 더 의미 있는 반성적 탐구를 했다는 것을 알 수 있었다. 탐구능력과 인지양식에 있어서 이질그룹은 정의적 측면에서 대립적 상호작용양식을 보여 반성적 탐구에 가장 부정적인 영향을 끼쳤고, 인지양식과 탐구능력 모두에서 동질그룹은 조화적 상호작용양식을 보여 반성적 탐구에 긍정적인 영향을 주었다는 것을 알 수 있었다. 이러한 결과로부터 반성적 탐구활동을 촉진시키기 위한 그룹조직의 시사점을 얻을 수 있었다.

• Structural Engineering and Mechanics
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• 제3권2호
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• pp.107-120
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• 1995

A soil-structure interaction formulation is used here which is based on consideration of the dynamics of the structure with a free, rather than a fixed, base. This approach is shown to give a quite simple procedure for coupling the dynamic characteristics of the structure to those of the foundation and soil in order to obtain a matrix formulation for the complete system. In fixed-base studies it is common to presume that each natural mode of the structure has a given fraction of critical damping, and since the interaction formulation uses a free-base model, it seems natural for this situation to assign the equal modal damping values to free-base modes. It is shown, though, that this gives a structural model which is significantly different than the one having equal modal damping in the fixed-base modes. In particular, it is found that the damping matrix resulting in equal modal damping values for free-based modes will give a very significantly smaller damping value for the fundamental distortional mode of the fixed-base structure. Ignoring this fact could lead one to attribute dynamic effects to interaction which are actually due to the choice of damping.

• 한국지진공학회논문집
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• 제19권3호
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• pp.85-92
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• 2015

Response spectra of a building are made with a SDOF system taking into account a first mode shape, even though higher modes may affect on the dynamic responses of a high-rise building. A soft soil layer under a building also affects on the responses of a building. In this study, seismic responses of a MDOF system were investigated to examine the effects of higher modes on the response of a tall building by comparing them with those of a SDOF system including the kinematic interaction effect. Study was performed using a pseudo 3D finite element program with seven bedrock earthquake records downloaded from the PEER database. Effects of higher modes on the seismic responses of a tall building were investigated for base shear force and base moment of a MDOF system including story shear forces and story moments. Study results show that higher modes of a MDOF system contribute to a reduction of base shear force up to 1/4-1/5 of KBC and base moment. The effect of higher modes is more significant on the base shear force than on the base moment. Maximum story shear force and moment occurred at the top part of a building rather than at a base in the cases of tall buildings differently from short buildings, and higher modes of a tall building affected on the base forces making them almost constant at the base. A soft soil layer also affects some on the base shear force of a high-rise building independently on the soft soil type, but a soft soil effect is prominent on the base moment.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2000년도 제18회 학술발표회 논문개요집
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• pp.118-118
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• 2000

We investigate Frohlich-like electron--optical-phonon interactionsin uniaxial crytals based on the macroscopic dielectric continuum model. In general, the optical-phonon branches support mixed longitudinal and transverse modes due to the anisotropy. For heterostructures with double interfaces and superlattices, it is known that confined, interface, and half-space optical phonon modes exist in zincblende cystals. In uniaxial structures, additional propagating modes may exist in wurtzite heterosystems due to anisotropic phonon dispersion. This is especially the case when the dielectric properties of the adjacent heterostructure materials do not differ substantially. The dispersion relations and the interaction Hamiltonians for each of these modes are derived.

• 한국HCI학회논문지
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• 제12권1호
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• pp.25-32
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• 2017

본 연구의 목적은 대화면 스마트폰을 한 손으로 조작 시 터치가 어려운 사각영역의 효율적인 터치를 지원하는 한 손 모드 인터랙션의 유용성을 평가하는 것이다. 이를 위해 아이폰과 안드로이드 스마트폰 내 두 종류의 기존 한손 모드들을 분석하였고, 보다 유용할 것으로 기대되는 두 개 유형의 한 손 모드들을 추가적으로 제안하고 구현하였다. 기존 및 제안한 한 손 모드들의 유용성을 검증하기 위해, 네 개의 한 손 모드들과 일반터치를 비교하는 실험을 수행하였다. 실험 결과, 일반터치에 비해 한 손 모드로 사각영역을 터치하는데 오히려 더 긴 시간이 걸렸다. 이는 한손 모드의 경우 모드진입 조작 및 모드전환 애니메이션 시간이 기본적으로 필요했기 때문이었다. 그러나 실험참여자들이 일반터치로 사각영역을 터치 시에는 엄지를 많이 뻗어서 터치해야 해서 손의 위치변화가 커지고 연속된 조작을 어려워하였다. 또한 한 손 모드로의 전환효과와 터치 조작반경의 축소로 인하여 주관적 만족도는 한 손 모드를 사용하는 것이 더 높았다. 한편, 한 손 모드들 중에서는 아이폰의 하단이동 한 손 모드가 가장 좋은 것으로 평가되었다.

• 대한인간공학회지
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• 제33권3호
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• pp.241-253
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• 2014

Objective: The objective of this study was to examine multi-modal interaction effects of input-mode switching on the use of smart phones. Background: Multi-modal is considered as an efficient alternative for input and output of information in mobile environments. However, there are various limitations in current mobile UI (User Interface) system that overlooks the transition between different modes or the usability of a combination of multi modal uses. Method: A pre-survey determined five representative tasks from smart phone tasks by their functions. The first experiment involved the use of a uni-mode for five single tasks; the second experiment involved the use of a multi-mode for three dual tasks. The dependent variables were user preference and task completion time. The independent variable in the first experiment was the type of modes (i.e., Touch, Pen, or Voice) while the variable in the second experiment was the type of tasks (i.e., internet searching, subway map, memo, gallery, and application store). Results: In the first experiment, there was no difference between the uses of pen and touch devices. However, a specific mode type was preferred depending on the functional characteristics of the tasks. In the second experiment, analysis of results showed that user preference depended on the order and combination of modes. Even with the transition of modes, users preferred the use of multi-modes including voice. Conclusion: The order of combination of modes may affect the usability of multi-modes. Therefore, when designing a multi-modal system, the fact that there are frequent transitions between various mobile contents in different modes should be properly considered. Application: It may be utilized as a user-centered design guideline for mobile multi modal UI system.

• 한국지구과학회지
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• 제30권3호
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• pp.366-380
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• 2009

본 연구는 수업의 3가지 맥락(자료, 과제, 역할)에서 학습자의 특성과 그룹의 상호작용에 따른 그룹과 개인의 반성적 탐구는 어떤 차이가 있는지를 알아보고 이를 통해 효율적인 반성적 탐구활동을 위한 소그룹 구성과 교사의 지도에 시사점을 얻고자 하였다. 이를 위해 고등학교 1학년 1개 학급을 선정해서 반성적 탐구활동수업을 실시하고 수업을 녹화 전사해서 언어행동분석틀과 수업상황의 3가지 맥락으로 분석하였다. 본 연구의 결과로부터 학생개인과 그룹의 반성적 탐구는 학생들의 개별특성 그 자체보다는 다튼 학생과 학급에서 어떤 관계를 가지느냐에 더 영향을 받는다는 것을 알 수 있었다.

• Steel and Composite Structures
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• 제21권1호
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• pp.195-216
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• 2016

The dynamic characteristics of continuous steel-concrete composite beams considering the effect of interlayer slip were investigated based on Euler Bernoulli's beam theory. A simplified calculation model was presented, in which the Mode Stiffness Matrix (MSM) was developed. The natural frequencies and modes of partial-interaction composite continuous beams can be calculated accurately and easily by the use of MSM. Proceeding from the present method, the natural frequencies of two-span steel-concrete composite continuous beams with different span-ratios (0.53, 0.73, 0.85, 1) and different shear connection stiffnesses on the interface are calculated. The influence pattern of interfacial stiffness on bending vibration frequency was found. With the decrease of shear connection stiffness on the interface, the flexural vibration frequencies decrease obviously. And the influence on low order modes is more obvious while the reduction degree of high order is more sizeable. The real natural frequencies of partial-interaction continuous beams commonly used could have a 20% to 40% reduction compared with the fully-interaction ones. Furthermore, the reduction-ratios of natural frequencies for different span-ratios two-span composite beams with uniform shear connection stiffnesses are totally the same. The span-ratio mainly impacts on the mode shape. Four kinds of shear connection stiffnesses of steel-concrete composite continuous beams are calculated and compared with the experimental data and the FEM results. The calculated results using the proposed method agree well with the experimental and FEM ones on the low order modes which mainly determine the vibration properties.

• 대한가정학회지
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• 제47권5호
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• pp.107-121
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• 2009

The purpose of this study was to examine leadership-related variables of young children. Subjects were 467 fiveyear-olds from the region. Data were subjected to descriptive statistical analysis. Pearson’s correlation, and multiple regression analysis. Results showed that leadership in young children was related to their temperament, peer interaction, verbal control modes of mothers, and home environment. Positive peer interaction was the strongest predictor for leadership of young children.