• Journal of KIISE:Computer Systems and Theory
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• v.34 no.10
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• pp.511-520
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• 2007

Decay usage scheduling algorithm gives preference to processes that have consumed little CPU in the recent past. It has been widely-used in time-sharing systems such as UNIX, where CPU-intensive processes and interactive processes are mixed. However, there has been no sound understanding about the mixed effects of decay usage parameters on the service performance. This paper empirically analyzes their effects in terms of the resulting service bandwidth and delay Based on such empirical analysis, we derive the clear meaning of each parameter. Such analysis and understanding provides a basis of controlling decay usage parameters for desirable service provision as required by applications.

• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.6
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• pp.991-1000
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• 1987

Existence of triple flames in a lean-rich concentration field is studied both experimentally and theoretically using large activation energy asymptotic technique adopting counterflow system as a model problem. Experiment shows that in triplet system of a lean and a rich premixed flame separated by a diffusion flame, either lean or rich premixed flame merges with diffusion flame as stretch is increased, such that transition boundary between 3-flame and 2-flame exists. The region in which 3-flame can exist forms an island within rich-lean concentration fields for large stretch, where as it is extends to the line of (.OMEGA.$_{0}$/.OMEGA.$_{F}$)$_{R}$=0 or (.OMEGA.$_{F/}$.OMEGA.$_{0}$)$_{L}$=0 for small stretch. Theoretical results show the qualitative agreement with experiment and the existence of limiting stretch over which 3-flame can not exist.t.t.t.t.t.t.

• Journal of the Korean Chemical Society
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• v.27 no.6
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• pp.399-404
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• 1983

Raman spectra for the carbonyl stretching mode of the amides, and amide-solvent systems have been recorded to investigate the effect of alkyl substitutions at the carbonyl carbon and at the nitrogen on the amide hydrogen-bonding. The data have shown that the interaction affinities are in the order of amide-amide > amide-water > amide-alcohol in formamide system, and amide-water > amide-amide > amide-alcohol in acetamide and propionamide systems. The strength of the proton acceptor of the carbonyl oxygen is increased by the presence of alkyl group to the carbonyl carbon and the proton donorcity of the amide is decreased by the alkyl substitution at the nitrogen. The above results are in good agreement with the ab initio SCF MO calculation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.2
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• pp.286-290
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• 2008

This paper summarizes the components of an explicit aeroelastic solver developed especially for the simulation of dynamic fracture events occurring during the flight of solid propellant rockets. The numerical method combines an explicit Arbitrary Lagrangian Eulerian (ALE) version of the Cohesive Volumetric Finite Element (CVFE) scheme, used to simulate the spontaneous motion of one or more cracks propagating dynamically through a domain with regressing boundaries, and an explicit unstructured finite volume Euler code to follow the flow field during the failure event. A key feature of the algorithm is the ability to adaptively repair and expand the fluid mesh to handle the large geometrical changes associated with grain deformation and crack motion.

• Journal of the Korea Safety Management & Science
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• v.14 no.3
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• pp.229-236
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• 2012

소프트웨어 기반의 시스템 설계과정에서 설계자가 고려해야 하는 요소들이 다양해지면서 시스템 설계가 점점 어려워지고 있다. 다양한 설계 요소들이 존재하지만 사용자의 특성 및 직무, 사용가능한 정보기술의 특성 등이 핵심적인 요소로 간주된다. 또한 정보기술이 발달하면서 인간과 시스템의 상호작용이 점점 인지적인 특징을 지니게 되었다. 따라서 사용성 높고, 효율적이면서 안전한 소프트웨어 기반의 시스템을 개발하기 위해서는 시스템 설계자가 사용자의 인지적인 요구사항 및 그들의 직무를 시스템 설계과정에서 체계적으로 다룰 수 있어야 한다. 그러나 소프트웨어 공학, 시스템 공학 및 인간-컴퓨터 상호작용 등에서의 전통적인 시스템 설계 방법은 이러한 설계자의 설계활동을 효과적으로 지원하는데 한계가 있었다. 그 대안으로 인지시스템공학(cognitive systems engineering; CSE)은 인간중심의 설계철학을 바탕으로 소프트웨어 기반의 복잡한 시스템 설계과정에서 설계자의 활동을 체계적으로 도와줄 수 있는 유용한 개념과 방법을 제공해주고 있다. CSE는 원래 사람이 실시간으로 감시 및 제어해야 하는 복잡한 사회기술적 시스템(예: 원자력발전소 및 공항관제소)의 분석, 설계 및 평가를 위해 태동한 학문이다. 그러나 CSE에서 제공하는 이론적 및 방법론적 프레임워크는 소프트웨어 기반의 시스템을 설계하는 데에도 유용하게 활용할 수 있는 충분한 가능성을 갖고 있다. 이 논문은 CSE의 근간을 이루는 핵심 개념 및 원칙을 고찰하고 소프트웨어 기반 시스템 설계에의 활용가능성 및 그 방안을 논의한다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.11 no.2
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• pp.77-89
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• 1991

Based on Boussinesq equation, the parabolic approximation equation is used to analyse the propagation of shallow water waves with currents over slowly varying depth. Rip currents (jet-like) occur mainly in shallow waters where the Ursell parameter significatly exceeds the range of application of Stokes wave theory. We employ the nonlinear parabolic approximation equation which is valid for waves of large Ursell parameters and small scale currents. Two types of currents are considered; relatively strong and relatively weak currents. The wave propagating over rip currents on a sloping bottom experiences a shoaling due to the variations of depth and current velocity as well as refraction and diffraction due to the vorticity of currents. Numerical analyses for a nonlinear theory are valid before the breaking point.

• Journal of Digital Contents Society
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• v.19 no.2
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• pp.277-284
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• 2018

This study suggested a brand alliance strategy of follow brand to overcome the leading brands. At the same time, we also examined the effect of Moderating the brand awareness of ingredient brands(high / low) and origin(favorable / unfriendly). First, purchase intention of alliance product showed significant interaction effect according to market entry order of parent brand and brand awareness of ingredient brand. Second, purchase intention of alliance product showed significant interaction effect according to market entry order of parent brand and country of origin. Based on the results, we discussed about theoretical and practical implications of this study, limitations of this study, and future research.

• Journal of Digital Convergence
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• v.9 no.2
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• pp.65-77
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• 2011

The current study investigated how interpersonal trust is developed in online communities, where most of individual identities are unknown or doubtful. To better understand and theorize the underlying mechanism, a survey was conducted integrating the literature on computer-mediated communication (CMC) and extending previous research on social identify model. The findings confirmed that integrity, benevolence, and openness are essential components in the concept of trustworthiness, which is predicted by social identification and persistency of communication activities in the virtual community.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.11a
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• pp.118-121
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• 2014

격자 양자 색역학(Lattice Quantum ChromoDynamics; Lattice QCD)은 자연계에 존재하는 중력, 전자 기력, 약한 핵력, 그리고 강한 핵력 등의 기본적인 상호작용 중 강한 핵력의 상호작용을 이해하기 위한 핵물리 분야의 이론이다. 이 물리 역학은 몬테 카를로(Monte Carlo) 기법을 이용하여 대규모 수치 연산을 필요로 하고, 수행시간 단축을 위하여 병렬처리가 필요하다. 본 논문에서는 격자 양자 색역학에서 요구되는 대규모 수치 연산에 대하여 마이크로프로세서와 성능가속기에 최적의 작업부하 분배를 통한 이기종 병렬처리 방법을 제안하고 성능가속기반을 사용한 방법과 제안 방법의 성능을 비교한다.

• The Journal of Natural Sciences
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• v.12 no.1
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• pp.41-48
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• 2002

Atomic coherences can be induced via atom-light interaction and can exhibit new interesting phenomena. Electromagnetically-induced-absorption (EIA) is one of such phenomena where the absorption of probe beam is increased due to the presence of strong coupling beam. EIA can be observed in multiple-V type atomic systems. This paper present a method to study EIA when the frequencies of probe beam and coupling beam are both near resonant to the same transition line. Time-varying interaction Hamiltonian was introduced and density matrix equations were solved and the amplitude of oscillations was used to calculate the EIA.