• 통상정보연구
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• 제10권2호
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• pp.117-139
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• 2008

This study examines the determinants of trade show performance of export-oriented small and medium enterprises(SMEs). In this regard, the trade show performance is categorized into two dimensions, such as sales objective performance vs. non-sales objective performance Based on the analysis of 116 exporters participated in trade show held in DaeGu EXCO, it is found that the roles of the show organizers play more important roles in both the sales objective performance and the non-sales objective performance than the roles of the exhibitors do. It is also interesting to find that export experience has a negative influence on both the sales objective performance and the non-sales objective performance. These results suggest that trade show organizers should provide high service quality so as to enhance the trade show performance of exhibitors.

• Nuclear Engineering and Technology
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• 제55권6호
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• pp.2125-2138
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• 2023

The printed circuit heat exchanger (PCHE) with airfoil fins has the benefits of high compactness, high efficiency and superior heat transfer performance. A novel multi-objective optimization approach is presented to design the airfoil fin PCHE in this paper. Three optimization design variables (the vertical number, the horizontal number and the staggered number) are obtained by means of dimensionless airfoil fin arrangement parameters. And the optimization objective is to maximize the Nusselt number (Nu) and minimize the Fanning friction factor (f). Firstly, in order to investigate the impact of design variables on the thermal-hydraulic performance, a parametric study via the design of experiments is proposed. Subsequently, the relationships between three optimization design variables and two objective functions (Nu and f) are characterized by an improved particle swarm optimization-backpropagation artificial neural network. Finally, a multi-objective optimization is used to construct the Pareto optimal front, in which the non-dominated sorting genetic algorithm II is used. The comprehensive performance is found to be the best when the airfoil fins are completely staggered arrangement. And the best compromise solution based on the TOPSIS method is identified as the optimal solution, which can achieve the requirement of high heat transfer performance and low flow resistance.

• 한국게임학회 논문지
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• 제7권2호
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• pp.1-10
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• 2007

MMORPG처럼 다수의 플레이어가 게임을 플레이하는 방식에서 과연 플레이어에게 많은 보상을 제공하는 것이 플레이어를 즐겁게 만드는 방법이 될 수 있을까? 그동안 대다수의 게임 개발 업체에서는 플레이어가 어떤 목표를 성취했을 때 단지 양의 보상만을 제공하면 플레이어들이 즐거워할 것이라고 판단해 왔다. 하지만 심리학의 형평이론에 따르면, 어떤 과업을 수행하는 과정에서 자신이 얻은 객관적 성과에 대한 만족감은 단지 자신이 투입한 노력 대비 객관적 성과를 제공 받는 것 뿐 아니라 타인의 경우도 함께 고려해서 객관적 성과에 대한 만족감을 경험하게 된다고 한다. 본 연구는 형평성 이론을 기반으로 MMORPG와 같이 타 플레이어와 다양한 형태의 협업 작업을 수행하는 경우 협업 작업의 형태에 따라 플레이어에게 객관적 보상을 달리해야 플레이어가 즐거움을 경험하게 될 것이라는 가설을 설정하고, 실제 MMORPG 플레이 과정을 통해 본 연구의 가설을 검증하였다. 결과를 살펴보면, 객관적 성과를 동일하게 제공했음에도 불구하고 객관적 성과의 제공 방식이 형평성을 유지했을 때 인지적 성과, 몰입, 행동 의도가 형평성이 유지 되지 못했을 때보다 더 높은 것으로 분석되었다. 이는 MMORPG처럼 다수의 플레이어가 함께 목표 성취를 수행할 경우에는 개별 플레이어의 노력에 따라 많은 양의 객관적 성과를 제공하는 것 보다는 객관적 성과에 대한 형평성을 보장해 주는 것이 플레이어의 즐거운 경험을 더 높일 수 있음을 말해 준다. 따라서 MMORPG를 기획할 때 플레이어의 협업 형태에 따른 적합한 보상 시스템을 설계하는 것이 플레이어의 즐거움을 더욱 높일 수 있을 것이다.

• 교육시설 논문지
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• 제18권2호
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• pp.25-33
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• 2011

This study performs the objective evaluation on simple comparison and calculation works by students under LED illumination conditions according to three types of color temperatures (7000K, 5000K, 3000K) in the classroom, Since the objective of this study is to develop an electric lighting conditions suitable for students in the classroom, the learning performance under three types of LED illumination conditions were analyzed. The 4 kinds of simple tests concerning with learning performance were developed and test results under natural light and LED illumination by 3 types of color temperatures were analyzed. There were differences by t-test in most cases among simple experiment results of different illumination conditions ($p{\leq}.05$). It was confirmed that illumination condition plays an important role when students simply compare words or perform arithmetic calculations. The experimental results of this study might be applied to designing better luminous environment.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.1247-1252
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• 2004

A objective quality assessment for the evaluation performance of a video transmission system as a basic step for construction of digital video transmission system between the spots and headquarter. Due to a limit of an analog video transmission system and the developments of various digital media and digital video standards, the need of introduce of a digital system are increased gradual1y, At this points. previously performance evaluations are performed and the quality assessment is the most important thing. We can be divided quality assessment method by the subjective quality assessment and objective quality assessment. The subjective quality assessment method has some problems which are required high cost and much time to evaluate the quality, And because existing objective quality assessment method such that PSNR are based on an analog form, the correlation with subjective data is very low. Therefore we design a new objective quality assessment method using Gabor wavelet transform reflecting HVS(Human Visual System), Designed objective quality assessment method is superior to other objective method such that PSNR or EPSNR In this paper, we proposed objective quality assessment using Gabor wavelet can be used for performance evaluation and verification of video transmission system.

• 한국멀티미디어학회논문지
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• 제16권4호
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• pp.472-482
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• 2013

본 논문에서는 실내 위치 인식 및 네트워크 성능 향상을 고려한 무선 랜 토폴로지의 구성 방안을 제안하였다. 먼저 위치 인식 및 네트워크 성능 향상을 고려하여 최적화된 무선 랜 토폴로지를 생성하는데 사용되는 4개의 목적 함수들을 설계하였다. 그리고 주어진 목적 함수로부터 근사 최적해를 생성하는 시뮬레이티드 어닐링과 타부 탐색 및 유전자 알고리즘 기반 메타 휴리스틱 알고리즘을 구현하였다. 마지막으로, 목적 함수와 메타 휴리스틱 알고리즘을 사용하여 제안한 무선 랜 토폴로지의 구성 방안에 대한 성능 분석을 수행하였다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제10권6호
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• pp.661-669
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• 2018

Engineering system problems consist of multi-objective optimisation and the performance analysis is generally time consuming. To optimise the system concerning its performance, many researchers perform the optimisation using an approximation model. The Response Surface Method (RSM) is usually used to predict the system performance in many research fields, but it shows prediction errors for highly nonlinear problems. To create an appropriate metamodel for marine systems, Lee (2015) compares the prediction accuracy of the approximation model, and multi-objective optimal design framework is proposed based on a confirmed approximation model. The proposed framework is composed of three parts: definition of geometry, generation of approximation model, and optimisation. The major objective of this paper is to confirm the applicability/usability of the proposed optimal design framework and evaluate the prediction accuracy based on sensitivity analysis. We have evaluated the proposed framework applicability in derrick structure optimisation considering its structural performance.

• Nuclear Engineering and Technology
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• 제42권4호
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• pp.460-467
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• 2010

In this study, the parameters of the feedwater control system (FWCS) of the OPR1000 type nuclear power plant (NPP) are optimized by response surface methodology (RSM) in order to acquire better level control performance from the FWCS. The objective of the optimization is to minimize the steam generator (SG) water level deviation from the reference level during transients. The objective functions for this optimization are relationships between the SG level deviation and the parameters of the FWCS. However, in this case of FWCS parameter optimization, the objective functions are not available in the form of analytic equations and the responses (the SG level at plant transients) to inputs (FWCS parameters) can be evaluated by computer simulations only. Classical optimization methods cannot be used because the objective function value cannot be calculated directely. Therefore, the simulation optimization methodology is used and the RSM is adopted as the simulation optimization algorithm. Objective functions are evaluated with several typical transients in NPPs using a system simulation computer code that has been utilized for the system performance analysis of actual NPPs. The results show that the optimized parameters have better SG level control performance. The degree of the SG level deviation from the reference level during transients is minimized and consequently the control performance of the FWCS is remarkably improved.

• Ocean Systems Engineering
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• 제5권2호
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• pp.91-107
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• 2015

Ship hull optimization is categorized as a bound, multi variable, multi objective problem with nonlinear constraints. In such analysis, where the objective function representing the performance of the ship generally requires computationally involved hydrodynamic interaction evaluation methods, the objective functions are not smooth. Hence, the evolutionary techniques to attain the optimum hull forms is considered as the most practical strategy. In this study, a parametric ship hull form represented by B-Spline curves is optimized for multiple performance criteria using Genetic Algorithm. The methodology applied to automate the hull form generation, selection of optimization solvers and hydrodynamic parameter calculation for objective function and constraint definition are discussed here.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.818-823
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• 2004

In case of the Korea Railroad, when we would decide the track structure, it has been introduced the whole track structure system based on only the foreign application cases and data offered by manufacturers without the process of the objective performance verification. The value of property for track materials, derived from the calculation of track structure, was hard to perform the objective performance evaluation among track structure systems because each manufacturer adopted the different test method and standard. To solve the above-mentioned problem, it should suggest the technical and objective evaluation method about the performance of track materials and meet with the standard of High Speed railroad and international railroad through the establishment and revision of performance standard. In the objective and technical respects, it will be a major role to decide the track structure. In this paper, I would like to summarize the case which was improved the problem of test method and standard exposed from the performance verification of Rail Fastening System among the track structure systems of High speed railroad.