• 산업공학
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• 제20권4호
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• pp.515-524
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• 2007

This paper introduces the methodology for restrict adjustment of 25 mail sorting centers including 3 new mail sorting centers to balance their work loads and minimize their operating costs. We calculated the capacity of mail sorting centers considering mail types and analyzed the collection/delivery mail volume of 214 post offices to measure the work loads of mail sorting centers. We also developed the mathematical model and genetic algorithm to find the optimal solution for this problem.

• 산업경영시스템학회지
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• 제31권3호
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• pp.8-16
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• 2008

Mail centers play an important role such as sorting and transporting postal items in the process of postal logistics. Therefore, there is need of efficiency measurement of the facilities to reduce the inefficiency of factors. But only few attempts have so far been made at measuring the efficiency of postal logistics hubs. The purpose of this paper is to make a reasonable suggestion for the improvement of inefficient mail centers. So this study found the efficient mail centers and inefficient mail centers using data envelopment analysis(DEA) and compared inputs and outputs of the former with those of the latter.

• 산업경영시스템학회지
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• 제33권1호
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• pp.10-16
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• 2010

Mail centers are essential postal facilities that sort and dispatch postal items, and should be operated efficiently to provide customers high quality postal services. So the efficiency analysis of mail centers should be performed in order to induce better operation. But current performance evaluation system has 95 percent of predetermined and weighted non-quantitative indices. There is need to introduce objective efficiency measurement methodology. The main objectives of this study was to analyze the efficiency of 24 mail centers empirically using cone-ratio DEA and suggest the appropriate cone-ratio method. Consequently, this paper suggests that the cone-ratio DEA model integrating decision-maker's preferences is more desirable for efficiency analysis than that of using transformed data.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2004년도 춘계공동학술대회 논문집
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• pp.586-589
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• 2004

This paper attempts to propose the decision support model, which can be employed for 22 mail centers to improve their operational efficiency and competitive. This model deals with both DEA method and system dynamics model. DEA is a management tool aimed to determine relative efficiency of independent decision making unit. We measured the relative efficiency between mail centers using CCR model and tried to find the reason for inefficiency mail centers. Also, we introduced the system dynamics model to present the strategic policy for mail center to strengthen their efficiency.

• 대한전자공학회논문지TC
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• 제47권11호
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• pp.7-13
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• 2010

우편물 배송에 있어서 신속함과 비용의 최소화를 위하여 각 구간별 운송거리와 더불어 우편 운송차량 수와 같은 가중치를 고려하여 우편물의 총 이동 거리를 최소화 할 수 있는 최적의 교환센터 선정이 필요하다. 본 논문은 구간별 운송 차량수와 운송 거리를 고려하여, 국내 주요 도시에 위치한 우편 집중국을 연결하는 최적 위치의 교환센터를 GOSST 이론을 이용하여 찾는 방법을 제안한다. 이 방법으로 교환센터의 위치를 선정할 경우, 현재의 대전을 교환센터로 하는 방법은 물론, 운송차량 수와 같은 가중치를 고려하지 않은 스타이너 트리 방법에 비해 전체 우편물의 총 이동거리를 줄일 수 있다. 제안 방법은 신속한 배송과 비용의 최소화는 물론 환경 보호 측면에서도 바람직하다할 수 있다. 제안된 방법은 실험에서 스타이너 트리를 이용한 방법에 비해 2.52%, 현재의 방법에 비해 6.66%의 우편물의 총 이동 거리를 절감시킬 수 있었다. 제안된 방법은 우편물 배송뿐 아니라, 다양한 전압 및 가중치를 고려해야하는 송전 시스템 라우팅, 배전선로망 구성, 전력 중계소의 위치 선정 등에도 활용가능하다.

• Journal of Information Technology Applications and Management
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• 제9권4호
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• pp.13-34
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• 2002

This paper considers a postal transportation planning problem in the transportation network of the form of hub and spoke Given mail sorting centers and an exchange center, available vehicles and amount of mails to be transported between mail sorting centers, postal transportation planning is to make a transportation plan without violating various restrictions. The objective is to minimize the total transportation cost. To solve the problem, a tabu search algorithm is proposed. The algorithm is composed of a route construction procedure and a route improvement procedure to improve a solution obtained by the route construction procedure using a tabu search. The tabu search uses the best-admissible strategy, BA, and the first-best-admissible strategy, FBA. The algorithm was tested on problems consisting of 11, 16 and 21 mail sorting centers including one exchange center. Solutions of the problems consisting of 11 mail sorting centers including one exchange center were compared with optimal solutions On average, solutions using BA strategy were within 0.287% of the optimum and solutions using FBA strategy were within 0.508% of the optimum. Computational results show that the proposed algorithm can solve practically sized problems within a reasonable time and the quality of the solution is very good.

• 산업공학
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• 제21권1호
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• pp.120-130
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• 2008

In this paper, we develop a transportation planning system for the mail transportation network, which consists of 25 mail centers and one mail exchange center. The main functions of the system are adjustment of transportation plan, creation of new transportation plan, and calculation of expected exchange mail volume which are transported through mail exchange center. We develop an adjusting algorithm which gives a new transportation plan by deleting, adding or changing the current routes. The algorithm based on the transportation results of current transportation plan and mail volume data. We design and implement a planning system by installing the algorithm as the planning engine. For the practical use, the system is connected to the information system of Korea Post, PostNet.

• 산업기술연구
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• 제24권A호
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• pp.263-271
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• 2004

Recently, the public postal service of Korea confronts with business environment changes such as the opening of postal market and appearance of the domestic competitive enterprises. It is the current state that the public postal service of Korea should have a competitive edge by the productivity improvement of business processes. In this paper, we proposed new working tables for manual letter sorting which is one of the important process in mail center. We suggested standard working method and standard time in a mail center Based on these, we established the procedure for setting up a fair day's work in other mail centers. By the result of this research, we expect that the productivity of the mail sorting operation will be increased.

• Child Health Nursing Research
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• 제11권3호
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• pp.308-315
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• 2005

Purpose: This descriptive study was conducted to examine the status of the health examination in child care centers. Method: The participants in this study were 631 child care centers. A self report questionnaire on health examination which has been examined for content validity, was distributed by mail to 2,000 child care centers using randomized sampling. Result: Of the sample, $76.2\%$ child care centers had done health examination for children. Height & weight, urinalysis, dental check, anemia test and visual acuity were the most frequently performed items. The rate for maintaining a health record was highest in the national/public child care centers. Child care centers more closely related to community health centers, showed higher rates of health examination. Conclusion: Health care personnel and financial aids should be provided for child care centers to enhance the level of health management of children.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2001년도 추계학술대회 논문집
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• pp.191-194
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• 2001

We consider a postal transportation planning in the transportation network of the form of hub and spoke. Given mail sorting centers and an exchange center, available vehicles and amount of mails to be transported between mail sorting centers, postal transportation planning is to make a transportation plan without violating various restrictions. The objective is to minimize the total transportation cost. To solve the problem, a tabu search algorithm is Proposed. The algorithm is composed of a route construction procedure and a route improvement procedure to improve a solution obtained by the route construction procedure using a tabu search. Computational results show that the proposed algorithm can solve practically sized problems within a reasonable time and the quality of the solution is acceptable.