• Annual Conference of KIPS
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• 2002.11c
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• pp.2431-2434
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• 2002

본 논문에서는 전체 영역 경로 계획인 CCPP(Complete Coverage Path Planning)를 이용해 전 청소 영역을 청소하는 방법을 나타내고 청소영역을 해석 하였다. 그리고, Template방법에 CD(Cell Decomposition)을 접목시킨 방법을 이용해 청소영역을 청소 후 재 경로계획으로 청소 안된 영역을 효율적으로 청소하는 방법을 연구하였다. 또한 청소기의 회전 및 직선 모션에 따른 청소 영역을 비교 해석해 최적 시간과 거리에 따른 경로 계획을 살펴보았다.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.7
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• pp.73-80
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• 2009

This paper describes a path planning algorithm, which is the minimal turning path based on the shape and size of the cell to clean up the whole area with two cleaning robots. Our method divides the whole cleaning area with each cell by cellular decomposition, and then provides some path plans among of the robots to reduce the rate of energy consumption and cleaning time of it. In addition we suggest how to plan between the robots especially when they are cleaning in the same cell. Finally simulation results demonstrate the effectiveness of the algorithm in an unknown area with multiple robots. And then we compare the performance index of two algorithms such as total of turn, total of time.

• Korean Journal of Construction Engineering and Management
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• v.11 no.4
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• pp.68-79
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• 2010

During the last two decades, several tele-operated and machine-vision-assisted systems have been developed in construction and maintenance area such as pavement crack sealing, sewer pipe rehabilitation, and excavation. In developing such tele-operated and machine-vision-assisted systems, trajectory plans are very important tasks for optimal motions of robots whether their environments are structured or unstructured. This paper presents an optimal trajectory planning algorithm used for a machine-vision-assisted automatic pavement crack sealing system. In this paper, the performance of the proposed optimal trajectory planning algorithm is compared with the greedy trajectory plans which are used in previously developed pavement crack sealing systems. The comparison is based on computational cost versus overall gains in crack sealing efficiency. Finally, it is concluded that the proposed algorithm plays an important role in productivity improvement of the automatic pavement crack sealing system developed.

• 한국노년학
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• v.31 no.4
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• pp.871-884
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• 2011

Standard Long-term care(LTC) Utilization Plan is a kind of care plan, which aims to help beneficiaries and their family choose services to meet their care needs. The objective of this study is to determine the relationships among family caregivers' perceived quality, overall satisfaction and utilization in Standard LTC Utilization Plan. Data were gathered from family caregivers with beneficiaries who have used community service in long-term care insurance system. A national cross-sectional descriptive survey was conducted in December 2008, using proportionate quota sampling. Finally, 351 family caregivers completed questionnaires which included demographic characteristics, perceived quality(9 items), overall satisfaction(1 item) and utilization(2 items). Path analysis was conducted to find a causal relationship. This study shows firstly, the quality of Standard LTC Utilization Plan was categorized into three dimensions, that is, assessment of care needs, recommended care plan, and management of monthly benefits. Secondly, reliability and validity of quality items were satisfied. Finally, in the effect of perceived quality and satisfaction for utilization, assessment of care needs(indirect effect, path coefficients=0.077) and overall satisfaction(total effect, path coefficients=0.324) were statistically significant. The findings of this study would be helpful in developing the strategies, which is needed to improve the role of Standard LTC Utilization Plan.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06b
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• pp.145-147
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• 2006

본 논문에서는 휴우리스틱 자원 시간 계획을 위한 새로운 탐색 알고리즘인 Strictly Enforced Hill-Climbing (SEHC)을 제안한다. 이 탐색 알고리즘은 FF 등의 계획기에 적용되어 매우 높은 효율성을 보인 Enforced Hill-Climbing (EHC)을 확장한 것이다. EHC는 목표를 찾아가는 과정 동안 매번 현재 상태에서 그 상태보다 더 낮은 휴우리스틱 값을 갖는 첫 번째 후손 상태를 찾아 넓이 우선 탐색을 펼치는 데 반해, 본 논문에서 제안하는 SEHC는 찾아진 첫 번째 후손 상태와 같은 깊이의 나머지 형제 상태들까지 탐색을 연장하여 최소의 휴우리스틱 값을 갖는 후손 상태를 찾아낸다. 이와 같은 SEHC 탐색방법은 매 주기마다 소량의 추가 탐색을 통해 탐색의 전체과정 동안 EHC 보다 우수한 탐색경로를 유지할 수 있도록 해준다. 본 논문에서는 다양한 영역의 계획문제를 대상으로 A* 알고리즘, EHC 알고리즘 등과의 비교실험을 통해 SEHC 알고리즘의 우수성을 알아본다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.11
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• pp.2199-2214
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• 1994

In order to sufficiently utilize the potential effectiveness of ATM networks, systematic and effective network management and control systems must be employed. In addition to network design, planning, and call routing techniques used in traditional circuit-switched networks. ATM networks can provide logical VP(Virtual Path) reconfiguration capabilities which can adapt to changes in the network environment. With a proper application of the VP reconfiguration technique, ATM networks can reduce the overhead of frequent network redesign and the overhead of call routing processing. However, ATM VP reconfiguration is a very complex and difficult problem which consists of many facets of optimization subproblems such as VP routing. VP sizing, VP terminating point location and VC routing. Most previous research on the ATM logical network reconfiguration problem dealt with the subset of the problem. This paper mathematically formulates the ATM network reconfiguration problem completely considering all subproblems. Since it is very difficult to derive the optimal solution of the formulated problem, we develop a heuristic method based on a Max min bandwidth allocation principle. We show the feasibility of the proposed heuristic method with a simple example.

• Journal of KIISE:Information Networking
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• v.34 no.2
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• pp.120-133
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• 2007

A multicast tree includes several, possibly a large number of, paths connecting source-receiver pairs, and network failure may disable part of the multicast tree. Reconstruction of the entire multicast tree to recover from a component failure is highly undesirable, because some group members have to suffer service disruptions even though the communication paths to/from them are not affected by the failure. To limit reconfiguration region and to maximize the likelihood of successful reconfiguration, we propose and evaluate a pre-planned reconfiguration policy for QoS multicast sessions. Specifically, we equip a reconfiguration path (RP) with each end-to-end path that connects a source-receiver pair in the multicast tree, and reserve resources in advance along the RPs. Efficient resource-sharing techniques are applied to reduce the amount of resources reserved for RPs but not used in the absence of failures. This way, we prevent uncontrolled competition among different multicast sessions which may simultaneously try to recover from failures. We evaluate the performance of the proposed scheme using simulation on randomly-generated networks. We use the shortest-path routing for QoS multicast sessions, and simulate both source-based and shared multicast trees. The evaluation results indicates that successful pre-planned reconfiguration can be achieved for all group members with reasonable overhead. Our scheme is also shown to adapt well to dynamic changes of group membership.

• Journal of Korea Port Economic Association
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• v.24 no.1
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• pp.61-83
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• 2008

The meaning of "added value" refers to the contribution of the factors of production, i.e., land, labor, and capital goods, to raising the value of a product and corresponds to the incomes received by the owners of these factors. The importance of added value in service industry has been recognized as one of the critical factors to economic growth, even in logistics industry. But, it is hard to find out the previous studies providing a clear definition and framework for designing and analyzing the performance of Value Added Logistics(VAL). The purpose of this study is to define the meaning of extended VAL that extensively includes activities initiating and operating the reverse logistics under the closed-loop logistic scheme, and to suggest the framework that describes the partnerships among participants involving in operating the value added logistics. Also, in this paper, we emphasize on the need for investigation of added value logistics definition and framework based on previous academic studies, and examine various value added logistics service activities of current leading 3PL companies across the world. Finally, we suggest the analytic framework for value added logistics throughout closed-loop logistics.