• 대한안전경영과학회지
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• 제15권1호
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• pp.77-85
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• 2013

In the location science, environmental effect becomes a new main consideration for site selection. For the unwanted facility location selection, decision makers should consider the cost of resolving the environmental conflict. We introduced the negative influence cost for the facility which was inversely proportional to distance between the facility and residents. An unwanted facility location problem was suggested to minimize the sum of the negative influence cost and the transportation cost. The objective cost function was analyzed as nonlinear type and was neither convex nor concave. Three GRASP (Greedy Randomized adaptive Search Procedure) methods as like Random_GRASP, Epsilon_GRASP and GRID_GRASP were developed to solve the unwanted facility location problem. The Newton's method for nonlinear optimization problem was used for local search in GRASP. Experimental results showed that quality of solution of the GRID_GRASP was better than those of Random_GRASP and Epsilon_GRASP. The calculation time of Random_GRASP and Epsilon_GRASP were faster than that of Grid_GRASP.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.971-976
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• 2004

The management of railroad structures is more difficult and complicate because there are many structures such as rail, bridge, tunnel, station, and so on. Therefore, LCC(Life Cycle Cost) analysis of railroad structures as public infrastructure must contain a maintenance cost as well as an initial cost in order to make a more effective management during the life cycle on the design phase. This paper presents a cost classification scheme considering user costs such as value of delayed time of passenger and freight. Also, in this study it is developed a probabilistic life cycle cost(PLCC) analysis model of railroad structures taking into account uncertainties and variations of input variables in order to analyze LCC. It may be stated that the model proposed in this study can greatly contribute to the making optimal decision, the estimate of the maintenance cost and the allocate of budget in the project of railroad structures.

• 대한전기학회논문지:전력기술부문A
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• 제52권8호
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• pp.457-462
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• 2003

This paper presents an optimal operating strategy of distributed generation (DG) with reliability worth evaluation of distribution systems. Using DG for peak-shaving unit could reduce the overall system operating cost, and using DG for standby power unit could reduce the customer interruption cost. If DG operating cost is less than utility power cost in peak time, DG should be running to reduce the overall system operating cost. When customer interruption cost enlarges, however, standby power strategy may be the better operating strategy than peak-shaving strategy. Selection of whether DG should be operated for peak-shaving or for standby power, needs the accurate reliability worth evaluation and the accurate power cost evaluation. Instead of using annual average reliability worth, the concept of hourly reliability worth is introduced in this paper to determine the optimal operating decision of DG. Applying suggested hourly reliability worth, the distribution companies that possess DG could set up the optimal operating strategy of DG.

• Structural Engineering and Mechanics
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• 제71권2호
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• pp.139-151
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• 2019

In a project schedule, it is possible to reduce the time required to complete a project by allocating extra resources for critical activities. However, accelerating a project causes additional expense. This issue is addressed by finding optimal set of time-cost alternatives and is known as the time-cost trade-off problem in the literature. The aim of this study is to identify the optimal set of time-cost alternatives using a multiobjective teaching-learning-based optimization (TLBO) algorithm integrated with the non-dominated sorting concept and is applied to successfully optimize the projects ranging from a small to medium large projects. Numerical simulations indicate that the utilized model searches and identifies optimal / near optimal trade-offs between project time and cost in construction engineering and management. Therefore, it is concluded that the developed TLBO-based multiobjective approach offers satisfactorily solutions for time-cost trade-off optimization problems.

• 한국공작기계학회논문집
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• 제18권1호
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• pp.59-67
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• 2009

The purpose of this study is to provide a decision support to select an appropriate layered manufacturing(LM) machine that suits the application of a part. Selection factors include concept model, form/fit/functional model, pattern model far molding, material property, build time and part cost that greatly affect the performance of LM machines. However, the selection of a LM is not an easy decision because they are uncertain and vague. For this reason, the aim of this research is to propose hybrid multiple attribute decision making approaches to effectively evaluate LM machines. In addition, because subjective considerations are relevant to selection decision, a fuzzy logic approach is adopted. The proposed selection procedure consists of several steps. First, we identify LM machines that the users consider After constructing the evaluation criteria, we calculate the weights of the criteria by applying the fuzzy Analytic Hierarchy Process(AHP) method. Finally, we construct the fuzzy Technique of Order Preference by Similarity to Ideal Solution(TOPSIS) method to achieve the ranking order of all machines providing the decision information for the selection of LM machines.

• Earthquakes and Structures
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• 제11권4호
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• pp.583-607
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• 2016

One of the main applications of seismic risk assessment is that an specific design could be selected for a bridge from different alternatives by considering damage losses alongside primary construction costs. Therefore, in this paper, the focus is on selecting the shape of pylon, which is a changeable component in the design of a cable-stayed bridge, as a double criterion decision-making problem. Different shapes of pylons include H, A, Y, and diamond shape, and the two criterion are construction costs and probable earthquake losses. In this research, decision-making is performed by using developed seismic risk assessment process as a powerful method. Considering the existing uncertainties in seismic risk assessment process, the combined incremental dynamic analysis (IDA) and uniform design (UD) based fragility assessment method is proposed, in which the UD method is utilized to provide the logical capacity models of the structure, and the IDA method is employed to give the probabilistic seismic demand model of structure. Using the aforementioned models and by defining damage states, the fragility curves of the bridge system are obtained for the different pylon shapes usage. Finally, by combining the fragility curves with damage losses and implementing the proposed cost-loss-benefit (CLB) method, the seismic risk assessment process is developed with financial-comparative approach. Thus, the optimal shape of the pylon can be determined using double criterion decision-making. The final results of decision-making study indicate that the optimal pylon shapes for the studied span of cable-stayed bridge are, respectively, H shape, diamond shape, Y shape, and A shape.

• 대한전자공학회논문지SP
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• 제48권3호
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• pp.42-49
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• 2011

본 논문에서는 H.264/AVC에서 동영상의 통계적 특성을 이용하는 고속의 효율적인 매크로블록 모드 결정 알고리즘을 제안한다. H.264/AVC의 메크로블록 모드 결정에서 Inter$16{\times}8$, Inter$8{\times}16$ 모드의 율-왜곡 비용을 이용하여, 각각 동일한 방향성을 가지는 Sub$8{\times}4$, Sub$4{\times}8$ 모드의 생략 여부를 결정한다. 또한 P$8{\times}8$ 인터모드 내 서브매크로블록(submacroblock)의 최적 모드를 이용하여, 동영상의 움직임 상관성에 근거하여 Intra$4{\times}4$, Intra$16{\times}16$ 모드의 생략 여부를 결정한다. 본 논문에서는 이러한 제안 기법들을 기존의 제안된 기법들의 장점들과 효과적으로 결합하여, 고속의 효율적인 매크로블록 결정 알고리즘을 제안한다. 실험 결과로부터, 제안 기법은 기존의 H.264/AVC 부호화 기법들에 비하여 부호화 효율을 유지시키면서 부호화 시간을 약 70% 단축시킬 수 있었다.

• 한국인구학
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• 제14권1호
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• pp.26-34
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• 1991

Migration studies that assume that decision making is done on an individual basis is overlooking the importance of the family factor. Considering that must people belong to families, it is more appropriate to view migration decision from the perspective of the family. This study analyzes the household migration decision whereby the alternatives are to stay, 10 undertake family migration or to undertake single migration of a member. In developing a conceptual model of household migration decision, it is assumed that the household's objective is to maximize household income which is a function of individual members' earnings. The benefits and costs of household migration and individual migration are identified and the household chooses the migration strategy that maximizes expected household income. When household members have conflicting earning prospects in the potential destination, the household considers single migration of the member with the best earning potentials. However, lone migration by a household member involves cost of family separation which is both monetary and psychic, and this study shows that lone migration is undertaken only when its net gains to the family are greater than the separation cost of the family. The major benefit of choosing single migration is the retention of home base in the place of origin which can serve as an insurance against the uncertainty of obtaining a job in the destination, the benefit that is unavailable in family migration. The conceptual analysis shows how a household's migration decision would depend on its members' economic roles and prospects in the destination. Besides the economic variables, social and life cycle variables of the family translate into separation costs and benefits of migration. This study indicates that one - earner family in low economic status but with good earning prospects and high separation costs is more likely to choose family migration over single migration.

• 한국건설관리학회논문집
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• 제4권2호
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• pp.91-98
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• 2003

국내 건축설계 프로젝트에서는 협력업체간의 커뮤니케이션이 원활치 못하여 건축 부위 설계 시 성능 및 비용을 만족하는 적절한 설계대안 생성이 어려울 뿐 아니라, 설계단계에서부터 시공단견1에 이르기까지 다양한 원인으로 발생되는 설계변경에 적절히 대응하지 못하고 있다. 따라서 분야별 설계도서의 불일치로 인한 시공 품질 저하 등의 문제가 발생되고 있다. 이에 따라 본 연구에서는 건축설계단계에서 합리적인 건축설계대안 생성을 위한 협력설계 의사결정 지원시스템 구축방법의 개념을 제시하였다.

• 보건행정학회지
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• 제23권2호
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• pp.188-195
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• 2013

Background: The separation of pharmaceutical prescription and dispensing law was implemented in July 1st of 2000. This law was initiated by government without a through consensus among related stakeholders in the process of policy decision, eventually raising contention about decision making process rather than the performance of the policy. Methods: Therefore, this study tries to identify the accomplishment of the policy goals; based on the last decade's research we assessed inhibition of unnecessary prescription, drug misuse and overuse prevention, prevention of drug-related sentinel events, reducing unnecessary drug utilization, and reducing nation's medical cost. Results: Assessment results represent that government-suggested goal of the policy lacks sufficient evidence to evaluate accomplishment. Conclusion: Unlike other studies that evaluate problems regarding drug dispensing policy in the policy decision process, this study is meaningful in that it evaluated the policy goal based on the last ten years of related study results.