• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1310-1315
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• 2003

In many practical engineering design problems, there are some design and manufacturing considerations that are difficult or infeasible to express in terms of an objective function or a constraint. In this situation, a set of optimal candidate designs having different topological complexities, not just a single optimal design, is preferred. To generate systematically such design candidates, we propose a hierarchical multiscale design resolution control scheme. In order to adjust its topological complexity by choosing a different starting resolution level in the hierarchical design space, we propose to employ a general M-band wavelet transform in transforming the original design space into the multiscale design space.

• 품질경영학회지
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• 제41권1호
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• pp.109-118
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• 2013

혼합물 성분비와 공정변수들에 관한 실험 자료가 주어진 경우에, 주어진 실험 자료를 잘 설명하는 적절한 결합모형을 찾는 것은 중요한 과제이다. 우선 모형 선택 기준에 부합하는 시작모형의 후보들을 교적모형의 범주에서 찾고, 다음으로 선택된 시작모형을 완전모형으로 간주하여, 모형의 간결성의 원칙에 따라서 완전모형의 부분모형으로 구성된 적절한 결합모형들을 찾는데, 일반적으로 여러 개의 결합모형들이 추천된다. 주어진 실험 자료에 대한 적절한 모형으로 여러 개의 모형이 추천된 경우에, 엔지니어들의 실용적인 관심사는 각각의 결합모형에 대한 반응변수의 기대값의 예측치와 예측치의 표준편차의 추정치를 동시에 최적으로 하는 최적조건의 찾기이다. 이를 위한 실용적인 방법으로 반응변수가 여러 개인 다중 반응표면 분석에서 동시 최적화 기법을 활용한 최적조건을 찾는 방법을 제안하고, 잘 알려진 혼합물성분-공정변수 실험 자료에 대해서 Design Expert 8.0을 활용하여 적절한 결합모형들을 찾고, 이 모형들을 동시에 최적화하는 최적조건 찾기가 예시된다.

• Nuclear Engineering and Technology
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• 제48권6호
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• pp.1291-1302
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• 2016

This paper presents a new and efficient scheme to determine the optimal neutron source position in a model near-equilibrium pressurized water reactor, which is based on the OPR1000 Hanul Unit 3 Cycle 7 configuration. The proposed scheme particularly assigns importance of source positions according to the local adjoint flux distribution. In this research, detailed pin-by-pin reactor adjoint fluxes are determined by using the Monte Carlo KENO-VI code from solutions of the reactor homogeneous critical adjoint transport equations. The adjoint fluxes at each allowable source position are subsequently ranked to yield four candidate positions with the four highest adjoint fluxes. The study next simulates ex-core detector responses using the Monte Carlo MAVRIC code by assuming a neutron source is installed in one of the four candidate positions. The calculation is repeated for all positions. These detector responses are later converted into an inverse count rate ratio curve for each candidate source position. The study confirms that the optimal source position is the one with very high adjoint fluxes and detector responses, which is interestingly the original source position in the OPR1000 core, as it yields an inverse count rate ratio curve closest to the traditional 1/M line. The current work also clearly demonstrates that the proposed adjoint flux-based approach can be used to efficiently determine the optimal geometry for a neutron source and a detector in a modern pressurized water reactor core.

• 한국정보과학회논문지:소프트웨어및응용
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• 제26권12호
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• pp.1468-1481
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• 1999

didates.본 논문은 절차 중심 소프트웨어를 객체 지향 소프트웨어로 재/역공학하기 위한 다단계 절차중 첫 절차인 객체 추출 절차에 대하여 기술한다. 사용한 객체 추출 방법은 전처리, 기본 분할 및 결합, 정제 결합, 결정 및 통합의 다섯 단계로 이루어진다 : 1) 전처리 과정에서는 객체 추출을 위한 FTV(Function, Type, Variable) 그래프를 생성/분할 및 클러스터링하고, 2) 기본 분할 및 결합 단계에서는 다중 객체 추출을 위한 그래프를 생성하고 생성된 그래프의 정적 객체를 추출하며, 3) 정제 결합 단계에서는 동적 객체를 추출하며, 4) 결정 단계에서는 영역 모델링과 다중 객체 후보군과의 유사도를 측정하여 영역 전문가가 하나의 최적합 후보를 선택할 수 있는 측정 결과를 제시하며, 5) 통합 단계에서는 전처리 과정에서 분리된 그래프가 여러 개 존재할 경우 각각의 처리된 그래프를 통합한다. 본 논문에서는 클러스터링 순서가 고정된 결정론적 방법을 사용하였으며, 가능한 경우의 수에 따른 다중 객체 후보, 객관적이고 의미가 있는 객체 추출 방법으로의 정제와 결정, 영역 모델링을 통한 의미적 관점에 기초한 방법 등을 사용한다. 이러한 방법을 사용함으로써 전문가는 객체 추출 단계에서 좀더 다양하고 객관적인 선택을 할 수 있다.Abstract This paper presents an object extraction process, which is the first phase of a methodology to transform procedural software to object-oriented software. The process consists of five steps: the preliminary, basic clustering & inclusion, refinement, decision and integration. In the preliminary step, FTV(Function, Type, Variable) graph for object extraction is created, divided and clustered. In the clustering & inclusion step, multiple graphs for static object candidate groups are generated. In the refinement step, each graph is refined to determine dynamic object candidate groups. In the decision step, the best candidate group is determined based on the highest similarity to class group modeled from domain engineering. In the final step, the best group is integrated with the domain model. The paper presents a new clustering method based on static clustering steps, possible object candidate grouping cases based on abstraction concept, a new refinement algorithm, a similarity algorithm for multiple n object and m classes, etc. This process provides reengineering experts an comprehensive and integrated environment to select the best or optimal object candidates.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권10호
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• pp.4157-4175
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• 2020

Moving target defense, as a 'game-changing' security technique for network warfare, realizes proactive defense by increasing network dynamics, uncertainty and redundancy. How to select the best countermeasure from the candidate countermeasures to maximize defense payoff becomes one of the core issues. In order to improve the dynamic analysis for existing decision-making, a novel approach of selecting the optimal countermeasure using game theory is proposed. Based on the signal game theory, a multi-stage adversary model for dynamic defense is established. Afterwards, the payoffs of candidate attack-defense strategies are quantified from the viewpoint of attack surface transfer. Then the perfect Bayesian equilibrium is calculated. The inference of attacker type is presented through signal reception and recognition. Finally the countermeasure for selecting optimal defense strategy is designed on the tradeoff between defense cost and benefit for dynamic network. A case study of attack-defense confrontation in small-scale LAN shows that the proposed approach is correct and efficient.

• 한국인터넷방송통신학회논문지
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• 제18권3호
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• pp.209-214
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• 2018

본 논문은 부패상품의 수송시간 제약조건 $L^*$이내로 총 수송비용을 최소화시키는 물류센터 위치를 결정하는 문제의 단순한 알고리즘을 제안하였다. 이 문제에 대해 Lee[4]는 후보 물류센터 위치를 선정하고, 각 물류센터의 총 수송비용을 구한 후, 상위 2개 물류센터에 대해 최적의 위치로 이동시키는 복잡한 방법을 제안하였다. 반면에 본 논문에서는 서브트리 개념을 도입하여 $L^*$ 이내가 되는 후보 물류센터의 위치를 간단히 결정하고, 근방 개념을 도입하여 요구량이 집중화된 지역 상위 2개 지역에 대해 총 수송비용이 최소화되는 지점을 단순히 최적의 위치로 결정하였다.

• 한국국방경영분석학회지
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• 제23권2호
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• pp.135-154
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• 1997

This paper deals with the perishable inventory models with uncertainties of demand functions. The traditional perishable inventory costs of holding and stockout are incorporated into the cost function. The average expected cost will be minimized to find the optimal quantile estimator. After three candidate estimators are proposed on the basis of order statistics, they will be evaluated by the simulation results and statistical analysis. Then the transition procedure algorithm using this estimator will be proposed to make the optimal decision under uncertainty.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 V
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• pp.2787-2790
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• 2003

In this paper, we predict tracking performance of the multiple hypothesis tracking (MHT) algorithm. The MHT algorithm is known to be an optimal Bayesian approach and is superior to asly other tracking filters because it takes into account the events that the measurements can be originated from new targets and false alarms 3s well as interesting targets. In the MHT algorithm, a number of candidate hypotheses are generated and evaluated later as more data are received. The probability of each candidate hypotheses is approximately evaluated by using the hybrid conditional average approach (HYCA). We performed numerical experiments to show the validity of our performance prediction.

• 경영과학
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• 제8권1호
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• pp.91-108
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• 1991

This paper presents an efficient optimization algorithm for the crude oil tanker scheduling problem. The algorithm consists of two stages. In stage one, all the potentially optimal schedules (called 'candidate schedules') are generated from feasible schedules for each ship. In the second stage, a multiple ship scheduling problem is formulated as 0-1 integer programming problem considering only the those candidate schedules. The efficiency of the suggested algorithm was improved by exploiting the special structure of the formulation. The algorithm was illustrated by a numerical example and tested on practical ship scheduling problems.

• Journal of Information Processing Systems
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• 제19권1호
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• pp.46-54
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• 2023

To improve the railway transportation capacity and maximize the benefits of railway transportation, a method for layout optimization of railway transportation route based on deep convolution neural network is proposed in this study. Considering the transportation cost of railway transportation and other factors, the layout model of railway transportation route is constructed. Based on improved ant colony algorithm, the layout model of railway transportation route was optimized, and multiple candidate railway transportation routes were output. Taking into account external information such as regional information, weather conditions and actual information of railway transportation routes, optimization of the candidate railway transportation routes obtained by the improved ant colony algorithm was performed based on deep convolution neural network, and the optimal railway transportation routes were output, and finally layout optimization of railway transportation routes was realized. The experimental results show that the proposed method can obtain the optimal railway transportation route, the shortest transportation length, and the least transportation time, maximizing the interests of railway transportation enterprises.