• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2001년도 The Seoul International Simulation Conference
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• pp.136-140
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• 2001

The 3rd generation mobile telecommunication fields are being standardized and developed in two parts, 3GPP and 3GPP2. These two parts have established each Network Architecture Models to achieve the goals basically required in the 3rd generation and to make it progress to IP network in the future. To achieve these goals many system architectures are proposed. Not only functional aspects but also performance aspects are considered as major factors. This paper proposes a new method of performance evaluation modeling and simulation that improved the existing way. The method proposed in this paper is Aspect oriented logical performance analysis Modeling and Simulation method. This proposed method is expected to improve efficiency of performance analysis modeling and simulation on the 3rd generation mobile telecommunication system.

• 한국군사과학기술학회지
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• 제21권6호
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• pp.731-743
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• 2018

In this paper, a study result to decide the accuracy specifications of inertial sensors satisfying the performance requirements of SINS(ship's inertial navigation system) is proposed. To do this, the performance specifications of overseas SINS is surveyed and the detailed error analysis of SINS at stationary condition is performed. Also, a new performance index to indicate the performance of SINS is derived. Modelling and simulation results show that the accuracy specifications of inertial sensors to meet the performance requirements of SIGMA40XP, a typical overseas SINS, can be determined through the newly derived performance index in this paper.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2011년도 한국컴퓨터종합학술대회논문집 Vol.38 No.1(A)
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• pp.391-394
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• 2011

3rd party content service is a consumer-based wide selection of contents in which IPTV provider believes will enhance the service considerably extending the variety of contents to finally provide a personalized service. Therefore, the combination of 3rd party content services and the IPTV infrastructure creates a good revenue opportunity but they need to be created. IPTV offers to create personalized channels to distribute 3rd party content service. However, the cost of $3^{rd}$ party content delivery is high when the service is provided from a faraway server. IPTV provider requires an effective strategy of replica placement to minimize the cost without a tradeoff on the performance. We propose a cluster-based strategy of replica placement to find the right balance between cost and performance. The results demonstrate the achievement of an outstanding delivery time and low cost.

• Journal of Advanced Marine Engineering and Technology
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• 제37권6호
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• pp.623-630
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• 2013

본 연구는 기 개발된 인플래터블 카약(RPO-2)과 새롭게 개발된 인플래터블 카약(RD-FK-11, RD-FK-12)의 유체역학적인 성능평가를 위하여 경사시험과 선회시험은 해양공학수조에서 저항시험은 축소된 모형선을 제작하여 회류수조에서 수행되었다. 결론적으로 각각의 카약에 대한 다양한 성능시험결과 복원성 측면에서는 KONA가 유리하고, 선회력과 무게중심 측면에서는 RD-FK-12가 우수하고, 저항성능 측면에서는 RD-FK-11이 KONA와 RPO-2에 비해 우수하였다.

• KEPCO Journal on Electric Power and Energy
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• 제3권1호
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• pp.57-63
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• 2017

This study aimed at proposing a RD&D good practice policy guidelines for energy technology innovation in electric power industry, we identified the success factors on energy RD&D through representative case analysis such as energy RD&D demonstration project and strategy plan, technology road map, etc. Based on a successful case study, we have identified the key elements needed to suggest when setting a RD&D technology innovation policy framework for technological competitiveness in the power industry sector. We have presented guidelines for energy technology innovation direction from the full cycle perspective of RD&D. The energy RD&D innovation system that we have established is meaningful in that the implications are derived and reflected through the case analysis of developed countries. The results of this study are as follows; Enhancement of R&D investment performance, commercialization of research achievements, promotion of export industrialization of electric power industry, establishment of RD&D governance system of power energy, etc.

• 소성∙가공
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• 제18권1호
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• pp.73-79
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• 2009

In order to investigate the formability of friction stir welded(FSW) tailor welded blanks(TWB) with respect to the base material's directional combination, aluminum alloy AA6111-T4 sheets were welded with three different conjoining types: RD-RD, TD-RD and TD-TD. Here, RD and TD represent rolling and transverse directions, respectively. For experimental formability study, three tests with gradual complexity were performed: the simple tension test with various weld line directions for uni-axial elongation, the hemisphere dome stretching test for biaxial stretching and the cylindrical cup deep drawing test. As a result, all three forming tests showed that RD-RD type samples exhibited the best formability, while TD-TD type sheets showed the least formability performance.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제14권2호
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• pp.197-208
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• 2003

목 적：본 연구에서는 읽기 장애 아동들(Reading Disability)은 빠르게 제시되는 언어 자극을 처리하는데 핵심적인 문제를 갖고 있으며, 주의력 결핍/과잉 운동 장애 아동들(ADHD)은 반응의 억제에 어려움을 보인다고 가정하였다. 읽기 장애와 주의력 결핍/과잉 운동 장애 그리고 공존 장애 아동 집단을 대상으로 핵심적인 인지 특성을 밝혀보고자 시각/청각 주의력과 음소 변별 검사에서 세 집단의 수행 차이를 비교하였다. 방 법：1차 연구에서는 ADHD 아동 28명과 RD+ADHD 아동 16명에게 주의력의 차이를 평가하기 위해 개별적으로 전산화된 주의력 장애 진단 검사(ADS)를 실시한 후 시각적 주의력과 청각적 주의력의 집단 간 수행 차이를 전체 지능의 영향을 통제하고 비교하였다. 2차 연구에서는 RD+ADHD/RD 아동 13명과 ADHD 아동 13명, 정상 아동 12명에게 전산화된 음소 변별 검사를 실시한 후 지능의 영향을 통제하고 세 집단의 수행 차이를 비교하였다. 결 과：시각적 주의력에서는 유의한 차이가 나타나지 않았으나, 청각적 주의력에서는 RD+ADHD 집단이 유의하게 어려움을 보였으며, 반응시간의 변산성이 증대되는 경향성이 나타났다. 음소 변별 검사에서는 RD 수반 집단과 ADHD 집단이 모두 정상 통제 집단에 비해 오류를 더 많이 보였고, RD 수반 집단과 ADHD 집단간에 다른 수행 패턴을 보였다. 논 의：ADHD들은 RD의 수반여부에 상관없이 반응 억제와 일관적인 주의력 유지에 어려움을 보였고 RD가 공존하는 경우 청각적 주의력의 문제가 증폭되었다. 음소 변별 검사에서 RD가 목표반응에 정확하게 반응하는데 어려움은 나타났으나, ADHD와는 유의한 수행 차이를 나타내지 않았다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1215-1220
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• 2004

Reactive distillation (RD) is a combination process where both separation and reaction are considered simultaneously in a single vessel. This kind of combination to enhance the overall performance is not a new attempt in the chemical engineering areas. The recovery of ammonia in the classic Solvay process for soda ash of the 1860s may be cited as probably the first commercial application of RD. The RD system has been used for a long time as a useful process and recently the importance of the RD is enlarged more and more. In addition to that, the application fields of RD are diversely diverged. To make the most of the characteristic of RD system, we must decide the best operating condition under which the process shows the most effective productivity and should decide the best control algorithm which satisfies an optimal operating condition. Phosgene which is a highly reactive chemical is used for the production of isocyanates and polycarbonates. Because it has high reactivity and toxicity, its utilization is increasingly burdened by growing safety measures to be adopted during its production. Dimethyl Carbonate (DMC) was proposed as a substitute of phosgene because it is non-toxic and environmentally benign chemical. In this study, RD is used for DMC production process and the transesterification is performed inside of column to produce DMC. In transesterification, the methanol and ethylene carbonate (EC) are used as the reactants. This process use homogeneous catalyst and the azeotrope exists between the reactant and product. Owing to azeotrope, we should use two distillation columns. For this DMC production process, we can suggest two configurations. One is EC excess process and the other is methanol excess process. From the comparison of steady state simulation results where the Naphtali-Sandholm algorithm is used, it showed the better performance to use the methanol excess process configuration than EC excess process. Then, the dynamic simulation was performed to be based on the steady state simulation results and the optimal control system was designed. In addition to that, the optimal operating condition was suggested from previous results.

• 한국자동차공학회논문집
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• 제21권4호
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• pp.181-187
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• 2013

Performance of DI diesel engine with high fuel injection method is directly related to its emission characteristics and fuel consumption. In this study, numerical model of 3rd generation piezo-driven injector was designed to analyze the hydraulic performance. Also the injection response characteristics was investigated by using the AMESim simulation code. From this study, it was shown that 3rd generation piezo-driven injector had a faster response and had better control capability due to its hydraulic bypass-circuit that has potential to higher hydraulic characteristics and improved accuracy of injected fuel quantity.

• Journal of Power Electronics
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• 제7권4호
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• pp.310-317
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• 2007

In this paper, an analysis and hysteretic controller design of a $3^{rd}$ order buck converter is presented. The proposed hysteretic controller consists of an inner current-loop, just like the conventional cascade control scheme, and an outer voltage-loop for load voltage regulation. Although it is possible to include an inner current loop from different branches of the converter, from the feasibility and operational point of view, the load side capacitor current would be the better choice. The addition of an inner current-loop improves the dynamic performance of the converter while preserving the robustness of the hysteretic control. The controller formulation and closed-loop converter performance analysis are validated through computer simulations. Few experimental results of the proposed converter are given and compared with the buck converter.