• 산업경영시스템학회지
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• 제44권3호
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• pp.106-116
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• 2021

This paper considers a joint problem for blood inventory planning at hospitals and blood delivery planning from blood centers to hospitals, in order to alleviate the blood service imbalance between big and small hospitals being occurred in practice. The joint problem is to determine delivery timing, delivery quantity, delivery means such as medical drones and legacy blood vehicles, and inventory level to minimize inventory and delivery costs while satisfying hospitals' blood demand over a planning horizon. This problem is formulated as a mixed integer programming model by considering practical constraints such as blood lifespan and drone specification. To solve the problem, this paper employs a Lagrangian relaxation technique and suggests a time efficient Lagrangian heuristic algorithm. The performance of the suggested heuristic is evaluated by conducting computational experiments on randomly-generated problem instances, which are generated by mimicking the real data of Korean Red Cross in Seoul and other reliable sources. The results of computational experiments show that the suggested heuristic obtains near-optimal solutions in a shorter amount of time. In addition, we discuss the effect of changes in the length of blood lifespan, the number of planning periods, the number of hospitals, and drone specifications on the performance of the suggested Lagrangian heuristic.

• The Journal of Asian Finance, Economics and Business
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• 제8권4호
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• pp.381-389
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• 2021

This study aims to examine the effect of strategic planning, human resource management, and asset management on increasing the productivity of the rural economy. This research is a quantitative approach. The research sample was carried out by simple random sampling and data collection using a questionnaire so that 129 respondents were determined. The research test was conducted using multiple linear regression with the OLS (Ordinary Least Square model. The results obtained were that strategic planning, human resource management, and asset management had a significant positive effect on increasing the productivity of the rural economy. This shows that strategic planning is the most important thing in industry, companies, or organizations as a guideline to achieve optimal performance. In addition, human resource management and asset management are positive supports for increasing the economic productivity of rural communities to achieve welfare goals. This research proves that strategic planning must be carried out by considering the existing potential, both sources. natural resources, human resources, and economic resources Meanwhile, human resource management and asset management are mandatory to support the sustainability of an organization or company so that the benefits of the study as study material in strategic decision making, both in business and public policy.

• 한국수자원학회논문집
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• 제39권6호
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• pp.545-552
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• 2006

본 연구에서는 노후관망의 최적개량 계획수립을 위한 의사결정모형을 개발하였다. 각각의 관거에 대한 개량계획을 수립하는 기존에 개발된 다른 모형과 달리 노후화된 상수관망을 소구역으로 구분하여 각 소구역의 개량계획을 수립하였다. 개발된 모형에서는 최적개량 의사결정을 위해 개량비용(교체비용, 갱생비용, 유지보수비용), 개선이익(펌프운영비 감소이익, 누수 감소이익) 및 수리학적 타당성을 고려하였다. 화음탐색법을 최적화기법으로 적용하였으며 수리학적 타당성 검토를 위해 수리해석 모형인 EPANET을 연계하였다. 대구시의 실제 상수도관망에 개발된 모형을 적용하였으며, 매설기간과 관의 종류에 의존하는 기존 방법과 달리 관의 내구성, 통수능, 비용 등을 고려하는 최적개량의사결정 시스템으로 활용될 수 있음을 확인하였다.

• 한국환경복원기술학회지
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• 제22권5호
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• pp.45-56
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• 2019

Urban green areas are generally composed of relatively small and fragmented patches, but it is a critical factor for the quality of an urban environment. They have positive effects such as increasing green connectivity, reducing runoff, and mitigating urban heat. But, there is a lack of urban greening plans that consider the comprehensive effects of green space in real urban areas. To fill this gap in this literature, this study identifies a planning model that determines the optimal locations for maximizing green areas' multiple effects(e.g., heat mitigation and enhancement of connectivity) by using unused lots. This model also considers minimizing costs using meta-heuristic optimization algorithms. As a results, we finds 50 optimal plans that considers two effects within the limited cost in Nowon-gu. The optimal plans show the trade-off effect between connectivity, heat mitigation and cost. They also show the critical unused land lots for urban greening that are commonly selected in various plans. These optimal plans can effectively inform quantitative effectiveness of green space and their trade-off. We expect that our model will contribute to the improvement of green planning processes in reality.

• Human Ecology Research
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• 제58권4호
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• pp.539-560
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• 2020

This study presents work-family multiple-role planning by female university students as a new approach to worklife balance. Accordingly, this study examines university years as a key time frame during which students establish their career paths. This study integrates the social cognitive career theory and the planned behavior theory to design and evaluate a model that explains the work-family multiple-role planning process; in addition, it develops an optimal model to predict the intentions of female university students in work-family multiple-role planning. This study has conducted a structural survey with 500 female university students. After inspecting the data, the responses of 435 participants were used in the data analysis (SEM) with SPSS 21.0 and AMOS 21.0. The findings include the following. First, suitability of predictive model presents a satisfying fit. The major factors in this study's model (parental support, subjective norms, attitudes toward multiple-role planning, career decision self-efficacy, and outcome expectations) are verified as direct and indirect predictors of the work-family multiple-role planning intent of female university students. Second, the strongest predictive factor for the work-family multiple-role planning intent is the social environment factor (subjective norms), indicating that the influence of social pressure on intent is relatively large. The predictive model formulated under this study's integrated theoretical framework supplements existing research that focused on attitudes toward multiple-role planning as well as provides a more profound theoretical foundation on which work-family multiple-role planning behaviors can be better understood.

• Journal of Radiation Protection and Research
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• 제30권1호
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• pp.17-25
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• 2005

원자력 발전의 안정성이 사회적 문제로 제기된 이후 작업종사자에 대한 작업 중 방사선 피폭량에 대한 관심이 높아지고 있다. 현재의 방법에 의하면 방사선 작업 계획의 수립 시 작업 공간 내 선량률이 일정하다는 가정 하에 피폭선량을 예측하므로 작업 경로에 따른 피폭선량의 변화에 대한 고려가 이루어지지 않고 있다. 본 연구에서는 작업자와 선원과의 거리가 고려되 수정된 방사선 피폭량 계산식을 이용하여 방사성 폐기물 저장시설에서의 작업 중 작업경로 변화에 따른 방사선 피폭량을 계산하였다. 이 계산식을 이용하여 주어진 작업 공간과 선원 조건하에서 작업 중 방사선 피폭량을 최소로 하는 최적 작업경로를 탐색할 수 있는 수치해석 알고리즘을 제안하였다. 이를 위하여 2차원 작업공간에서 무한개의 작업경로를 유한개의 경로로 근사화하고 근사화된 모든 작업경로 중 피폭선량이 최소가 되는 작업경로를 탐색하였다. 또한, 3차원 그래픽 기술과 Java 프로그래밍을 이용한 가상작업 시뮬레이션 프로그램을 개발하고 작업 공간의 선량률 가시화 및 가상 작업 시뮬레이션을 수행하여 방사선 작업 계획의 수립을 위한 도구로서의 가능성을 검토하였다. 수치해석 계산과 시뮬레이션 과정을 통하여 최적 작업경로는 작업자와 선원과의 거리를 증가시키고 작업 시간을 단축시킬 수 있는 경로로 제시되었고, 이를 바탕으로 방사선 피폭량은 작업시간뿐만 아니라 작업자와 선원간의 거리에 영향을 받음과 최적화된 방사선 방호를 위해 작업경로가 고려되어야 함을 확인하였다.

• 품질경영학회지
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• 제14권1호
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• pp.61-66
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• 1986

Many papers have suggested various models how to decide an optimal time for replacing equipment. In this study, Dynamic Programming is applied to establish a model of replacing equipment and a new algorithm is developed for computerization to meet the increased number of variables. It is possible to predict the real situation with higher accuracy by employing the proposed model including more variables such as planning horizon, original cost, salvage value, decreasing rate, operating and maintenance costs, increasing rate, and so on.

• 산업공학
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• 제2권1호
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• pp.37-45
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• 1989

Guide path design is the most important factor in planning automated guided vehicle systems(AGVS) in manufacturing shop environments. This paper studies a heuristic procedure to design an optimal bi-directional guide path with the objective of the minimum total travel time of the vehicles. An example is solved to validate the procedure developed.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1181-1184
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• 1996

As usual systems, robot manipulators have also physical constraints for operating. It is a difficult problem that we operate manipulator in the minimal time under these constraints. In this paper, we solve this problem dividing it into two steps. In the first step, we find the minimal time trajectories by optimizing qubic polynomial joint trajectories using evolutionary algorithms. In the second step, we optimize controller for robot manipulator to track precisely trajectories optimized in the previous step.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 추계학술대회 논문집 학회본부
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• pp.191-193
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• 1989

This paper presents a optimal Var allocation algorithm for minimizing power loss and improving voltage profile in a given system. In this paper, nodal input data is considered as Gaussian distribution with their mean value and their variance. A stochastic Linear Programming technique based on chance constrained method is applied to solve the probabilistic constraint. The test result in IEEE-14 Bus model system showes that the voltage distribution of load buses is improved and the power loss is more reduced than before Var allocation.