• Journal of Magnetics
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• 제17권4호
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• pp.233-241
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• 2012

In this work, Monte Carlo simulation was used to investigate the magnetization properties of thin ferromagnetic films under a perturbation from a supplied heat pulse on one surface of the films. The finite difference method was used to extract the local temperature of each layer of the films as a function of time for various heat source power and heating period. Then, with the variation of the films temperature, Metropolis method was used to update the magnetic moment in magnetic grain, under the Ising framework and using the FePt parameters. With the extracted magnetization profiles, the relationship between magnetization relaxation in accordance with relevant heat parameters and films thickness was reported and discussed, with a purpose to form a database for future use.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2004년도 춘계학술대회 학술발표 논문집 제14권 제1호
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• pp.139-143
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• 2004

Lee et al have proposed a framework for the linguistic map-based navigational planning of a mobile robot on dynamic environment and provided simulation results applied it to the static environment[1], In this paper, we extends the navigational planning of a mobile robot into dynamic environment. There are two kinds of dynamic obstacles： (1) Time-obstacles that change condition of obstacles with time. (2) Space-obstacles that move their position with time. We propose an algorithm which a mobile robot identifies and avoids the two kinds of dynamic obstacles. The proposed algorithm consists of two stages： (1) The fuzzy logic-based perception stage which identifies the dynamic obstacles around a mobile robot by using sensory data and fuzzy rules, (2) The planning stage which plans the path to goal by avoiding the dynamic obstacles[2-6]. We provide computer simulation results for a mobile robot in order to show the validity of the proposed algorithm.

• 대한지리학회지
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• 제39권3호
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• pp.444-456
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• 2004

최근 GIS 분야에서는 GIS와 동적 프로세스 모델링에 기반한 셀룰라 오토마타(CA)의 결합을 통한 공간모델링 연구가 활발히 진행되고 있다. 그러나 선행 연구에서의 CA 모델링은 해결하고자 하는 문제의 핵심이 되는 규칙을 찾아내는 기능은 제공하지 못하고 있다. 본 연구에서는 GIS와 지식 발견 기법을 이용하여 공간 연관규칙을 추출하는 방법론을 제시하고 실제 사례에 적용하였다. 이러한 방법론의 제시는 CA 모델링의 기능을 더욱 향상시킬 것으로 기대된다. 또한 본 연구에서 사례로 적용한 도시지역 확장 외에 다양한 문제에 대한 활용이 가능할 것으로 판단된다.

• Asia pacific journal of information systems
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• 제9권3호
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• pp.177-194
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• 1999

Identifying knowledge as the single most important asset ultimately defining organizational competitiveness, enterprises are trying to move towards knowledge-oriented practices. Such practices have given rise to learning and agile organization, This paper presents applied information technologies to realize the learning and agile organization, focusing on systems thinking. Firstly, in order to establish a framework for the systems thinking, an information systems development method based on process chain is proposed. Then, an agent-based microworld simulation approach is presented. The approaches provide visible and analytical information to knowledge workers so that they can have systems thinking capabilities eventually. Various microworlds on the top of the information system can be constructed with agents and simulated for possible business events. All decision makings are dynamic in nature. To let knowledge workers look ahead the possible outcomes of the whole relevant processes is the core capability of the approaches. Through watching, the knowledge workers would be able to acquire new insights or problem solving knowledge for the problem in hand.

• Journal of International Society for Simulation Surgery
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• 제4권1호
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• pp.21-23
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• 2017

Purpose In this paper, we proposed alternate neighborhood system and reverse spread-direction approach for accurate and fast cellular automata-based image segmentation method. Materials and Methods On the basis of a simple but effective interactive image segmentation technique based on a cellular automaton, we propose an efficient algorithm by using Moore and designed neighborhood system alternately and reversing the direction of the reference pixels for spreading out to the surrounding pixels. Results In our experiments, the GrabCut database were used for evaluation. According to our experimental results, the proposed method allows cellular automata-based image segmentation method to faster while maintaining the segmentation quality. Conclusion Our results proved that proposed method improved accuracy and reduced computation time, and also could be applied to a large range of applications.

• Nuclear Engineering and Technology
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• 제41권1호
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• pp.21-38
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• 2009

The use of multi scale modeling concepts and simulation techniques to study the destabilization of an ultrathin layer of oxide interface between a metal substrate and the surrounding environment is considered. Of particular interest are chemo-mechanical behavior of this interface in the context of a molecular-level description of stress corrosion cracking. Motivated by our previous molecular dynamics simulations of unit processes in materials strength and toughness, we examine the challenges of dealing with chemical reactivity on an equal footing with mechanical deformation, (a) understanding electron transfer processes using first-principles methods, (b) modeling cation transport and associated charged defect migration kinetics, and (c) simulation of pit nucleation and intergranular deformation to initiate the breakdown of the oxide interlayer. These problems illustrate a level of multi-scale complexity that would be practically impossible to attack by other means; they also point to a perspective framework that could guide future research in the broad computational science community.

• Archives of Plastic Surgery
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• 제41권3호
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• pp.213-217
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• 2014

The widespread use of microsurgery in numerous surgical fields has increased the need for basic microsurgical training outside of the operating room. The traditional start of microsurgical training has been in undertaking a 5-day basic microsurgery course. In an era characterised by financial constraints in academic and healthcare institutions as well as increasing emphasis on patient safety, there has been a shift in microsurgery training to simulation environments. This paper reviews the stepwise framework of microsurgical skill acquisition providing a cost analysis of basic microsurgery courses in order to aid planning and dissemination of microsurgical training worldwide.

• JSTS:Journal of Semiconductor Technology and Science
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• 제6권1호
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• pp.1-9
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• 2006

We introduce our in-house program, NANOCAD, for the modeling and simulation of carrier transport in nanoscale MOSFET devices including quantum-mechanical effects, which implements two kinds of modeling approaches: the top-down approach based on the macroscopic quantum correction model and the bottom-up approach based on the microscopic non-equilibrium Green’s function formalism. We briefly review these two approaches and show their applications to the nanoscale bulk MOSFET device and silicon nanowire transistor, respectively.

• Advances in Computational Design
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• 제2권3호
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• pp.241-256
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• 2017

This paper introduces the process for Multi-objective Optimization Framework (MOF) which mediates multiple conflicting design targets. Even though the extensive researches have shown the benefits of optimization in engineering and design disciplines, most optimizations have been limited to the performance-related targets or the single-objective optimization which seek optimum solution within one design parameter. In design practice, however, designers should consider the multiple parameters whose resultant purposes are conflicting. The MOF is a BIM-integrated and simulation-based parametric workflow capable of optimizing the configuration of building components by using performance and non-performance driven measure to satisfy requirements including build programs, climate-based daylighting, occupant's experience, construction cost and etc. The MOF will generate, evaluate all different possible configurations within the predefined each parameter, present the most optimized set of solution, and then feed BIM environment to minimize data loss across software platform. This paper illustrates how Multi-objective optimization methodology can be utilized in design practice by integrating advanced simulation, optimization algorithm and BIM.

• Composites Research
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• 제15권5호
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• pp.44-52
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• 2002

To study numerically the mechanical behaviors of advanced composite materials considering the microscopic phenomena as well as the macroscopic properties and behaviors, a multi-scale modeling and analysis by the mathematical homogenization method with the help of the finite element method(FEM) are reviewed. The hierarchical modeling strategy and the formulation are briefly described first to give some idea of the multi-scale framework. The latter half of this article focuses on the verification of the multi-scale analysis by the homogenization method in its applications to real advanced materials. The first example is the verification of the predicted macroscopic(homogenized) properties based on the microstructure of porous ceramics. In spite of the complexity of the random microstructure, the error between the predicted and the measured values was only 1%. Next, two applications to the process simulation of fiber reinforced polymer matrix composites are presented. The permeability characteristics are evaluated for sheared weave fabrics for resin transfer molding(RTM) simulation, and the thermoforming of FRTP sheet is analyzed considering the large deformation of the knit structure during the deep-draw forming was verified by comparison with the experimental results.