• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.06a
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• pp.192-193
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• 2009

세계 항만환경은 초대형 컨테이너선의 등장이후, 허브 & 스포크(Hub & Spoke)의 형태로 급속히 변화하고 있다. 이에 해외 선진항만들은 중심항만으로서 자리매김하기 위해 자동화 컨테이너터미널을 구축하는 등 생산성 향상을 위한 노력을 하고 있으나, 국내의 경우 자동화 컨테이너터미널에 관한 연구, 그중 자동화 게이트시스템에 대한 연구는 상대적으로 미흡한 실정이다. 본 연구에서는 자동화 게이트시스템을 구축 시, 최적 기술 대안을 선정하기 위해 국내 외 게이트 운영현황과 관련 기술들의 분석함으로써 자동화 게이트시스템 구축 시 필요한 기술을 도출하다. 그 결과를 컨테이너터미널 운영사의 기술 담당자들을 대상으로 현재 게이트시스템의 만족도와 문제점 그리고 향후 게이트시스템 구축 시 사용하고자 하는 기술과 기대효과를 찾고자 하였다. 하지만 1차 설문결과 내용만으로는 어떤 요소 기술이 사용자가 요구하는 기대효과를 만족시킬 수 있는 최적 기술 대안인지 제시하기 힘들었다. 이를 보완하기 위한 방법으로 정성적인 주관적 평가요소를 객관화하여 각 평가기준에서 나타나는 적용상의 한계를 해결할 수 있는 방법인 AHP 기법을 활용하였으며, 최종적으로 생산성 보안성, 경제성 3가지 평가 기준을 고려하여 최적 기술 대안을 선정한 결과 RFID가 최적의 기술대안으로 평가되었다.

• Korean Journal of Construction Engineering and Management
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• v.19 no.5
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• pp.32-42
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• 2018

Since the success or failure of VE projects depends on the capabilities of participants, including owners, construction managers, architects, general contractors and VE experts, it is important to follow systematic procedures. However, it is often the case that only a rough evaluation is performed, or the rough and detailed evaluations are integrated in actual VE tasks. In this case, it is difficult to analyze and evaluate the alternatives in terms of risk, even for the important alternatives. This in turn leads to the so-called returning alternatives where the alternatives proposed in the preceding stage are returned to the original plans in the following stage, and thus the repetitive work for the alternatives often decreases the efficiency of the VE task. In this regard, this study proposed a risk assessment process for VE alternatives in order to minimize the occurrence of returning alternatives based on the systematic analysis and evaluation of VE alternatives. It will increase the efficiency of VE tasks by reduces the number of regression alternatives.

• Journal of Korean Society of Transportation
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• v.26 no.5
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• pp.175-184
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• 2008

Uncertainties are unavoidable in engineering applications. In this paper we propose an alpha reliable multi-variable network design problem under demand uncertainty. In order to decide the optimal capacity enhancement, three performance measures based on 3E(Efficiency, Equity, and Environmental) are considered. The objective is to minimize the total budget required to satisfy alpha reliability constraint of total travel time, equity ratio, and total emission, while considering the route choice behavior of network users. The problem is formulated as the chance-constrained model for application of alpha confidence level and solved as a lexicographic optimization problem to consider the multi-variable. A simulation-based genetic algorithm procedure is developed to solve this complex network design problem(NDP). A simple numerical example ispresented to illustrate the features of the proposed NDP model.

• Ecology and Resilient Infrastructure
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• v.3 no.2
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• pp.117-125
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• 2016

Current cities encounter various types of water problems due to rapid urbanization and climate change. The increasing significance of urban water problems calls for the establishment of resilient alternatives to prevent and minimize social loss that results from these phenomena. As a background research for establishing resilient infrastructures for the mitigation of urban water problems, we evaluated the robustness of structural alternatives for urban flood as a representative case. Combining the robustness index (RI) and the cost index (CI), we suggested the robustness-cost index (RCI) as an indicator of the robustness of structural alternatives, and applied the index to assess the existing infrastructures and structural alternatives (i.e., sewer network expansion, additional storage tank construction, and green roof construction) at a site prone to floods located around Gangnam-station, Seoul, Korea. At a rainfall intensity frequency range of 2 to 20 years, the usage of a storage tank and a green roof showed relatively high RCI value, with a variation of an alternative showing greater RCI between the two depending on the size of design rainfall. For a rainfall intensity frequency of 30 years, installing a storage tank with some green roofing was the most resilient alternative based on the RCI value. We proposed strategies for establishing resilient infrastructures for the mitigation of urban floods by evaluating the robustness of existing infrastructures and selecting optimal structural alternatives with the consideration of scales of design disaster.

• Journal of KIISE:Computing Practices and Letters
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• v.12 no.6
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• pp.349-357
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• 2006

We introduce a new performance evaluation methodology that helps programmers evaluate different tuning alternatives in order to improve program performance. This methodology permits measuring performance implications of using tuning alternatives. Specifically, the methodology predicts performance after workload migration for a distributed or parallel program in contrast to traditional performance methodlogies that quantify time spent in program components for bottleneck identification. The methodology thus provides guidance on workload migration. The methodology also permits predicting the performance impact of changing the underlying network. The methodology may evaluate performance incrementally and online during the execution of the program to be tuned. We show that our methodology, when it is implemented and used, permits accurately predicting the performance of different tuning alternatives for a test suite of six programs.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.5
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• pp.1007-1017
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• 2011

It is important to set the new interconnection system under NGN. The traditional interconnection system is based on traffic, but this is not suitable for IP based service. Therefore, it is needed to ensure the universal access to network without trouble about the network topology. This paper prepares the evaluation criteria and evaluates the alternatives. Specifically, we deduce the alternatives and evaluates the alternatives of interconnection settlement system based on the condition of efficient interconnection, the retail price and access charging model, and the previous studies evaluating and examining the various alternatives. Finally, we evaluate each alternatives by the criteria.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.512-516
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• 2005

우리나라에서는 이제까지 치수사업의 타당성 분석시 경제성 분석에 너무 치우쳐 사업에 대한 의사결정과정이 단편적으로 진행되어 왔다. 이러한 문제를 개선하고자, 본 연구는 AHP(Analytic Hierarchy Process)과 효용함수(utility function)를 이용하여 대안의 수립, 평가, 선정, 우선순위 결정에 이르는 치수사업 의사결정과정을 모형화 하였다. 모형의 적용결과, 최선대안의 선정시 경제성 기준이 여전히 큰 비중을 차지하고 있었으나 단위 사업안의 투자우선순위 결정에는 위험성, 지속가능성 기준의 영향도 상당부분 있었다. 그러나 대안들 간에 변별력을 높이기 위해서는 경제성 이외 기준들의 속성에서 공간적 정밀도를 높이는 추가연구는 필요한 것으로 판단되었다. 본 연구는 치수사업 계획이 유역 내 단위사업안들로 조합된 대안들의 평가를 통해 이루어져야 한다는 점을 보여주고 있으며, 향후 점차로 유역단위의 치수계획이 정립됨에 따라 본 연구를 바탕으로 보다 구체적인 연구가 수행되리라 기대된다.

• Journal of Korea Water Resources Association
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• v.45 no.4
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• pp.383-391
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• 2012

This study aims to present the sensitivity analysis approach for multi-criteria decision making (MCDM) method to reduce the uncertainty of weighting and performance values. This study focuses on two major problems of the uncertainty for MCDM method. The first major problem is how to determine the most critical criterion and the second is how to determine the most critical measure of performance. This study used the application of weighted sum method for water resources planning. The criticality degrees and the sensitivity coefficients of criterion and alternative are used. This results of sensitivity analysis can be applied to the general water resources planning in real.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.1307-1311
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• 2005

최근들어 Water Security에 대한 관심이 고조되고 있지만 국내의 경우 이에 대한 체계적인 연구가 아직 진행되지 않았고 상수도관망시스템의 오염예방 및 위험관리에 대한 연구는 매우 미비한 실정이며 특히 상수도관망시스템의 위험성 및 취약성에 대한 연구는 전무한 상태이다. 이러한 상수도관망시스템의 위험도와 관련된 여러 위험요소들은 인명의 피해, 재산상의 피해, 환경적 피해, 시스템의 피해 그리고 사회적 불안등 여러 기준을 고려하여 평가되어야 한다. 이 문제는 다기준의사결정(multi-criteria decision making)문제로서 평가기준들(criteria) 간의 상충관계(trade-off)로 인하여 판단이 모호한 대안들을 PROMETHEE(Preference Ranking Organization METHod Enrichment Evaluations) 기법을 이용하여 평가하였다. PROMETHEE는 선호의 유출량(leaving flow)과 유입량(entering flow)의 개념을 이용하여 여러 대안들의 순위선호(outranking)를 산정하는 기법으로, 의사결정자(decision matter)가 비교적 쉽게 이해할 수 있으며 기존의 AHP$\cdot$ANP와는 달리 명확한 판단이 어려운 대안들에 대해서는 비교불가능한(incomparable) 대안으로 분류한다. 이와 같은 위험도 평가결과는 위기상황에 대한 대처방안을 제시할 의사결정시스템 구축의 기초 자료가 될 수 있을 것이다.

• Journal of Wetlands Research
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• v.11 no.3
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• pp.71-80
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• 2009

Due to the various characteristics of urban river, rehabilitation project for natural river requires distinct alternative approach and selection method for each different types of river. In this study, naturalness of a river was used to establish such alternative for the business and rehabilitation plan for natural river. To assess the naturalness of a river, through AHP, designed to fit the environmental conditions in Korea, was employed. Furthermore, a method that conveniently compares and selects an alternative for rehabilitation plan for natural river by referencing Urban River Basin Enhancement Methods (URBEM) was proposed. After selecting the evaluation items for assessing the naturalness of the river based on the characteristics of the river, multiple alternatives were constructed and the naturalness of river for each of those alternatives were estimated. Comparing the estimated values has made the measurement of the natural recovery effect and the product of river rehabilitation plan for each alternative efficient. In conclusion, selecting the items for evaluating the naturalness of a river with respect to its characteristics was found to be effective for establishing the rehabilitation plan for natural river.