• Journal of Korean Society of Transportation
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• v.22 no.7 s.78
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• pp.107-117
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• 2004

The growing demand for customer-response, made-to-order manufacturing and satisfactory delivery are stimulating the importance of commercial fleet management problem. Moreover, the rapid transformation to the customer-oriented multi-frequency, relatively small fleet, such as home delivery and Perishable goods, requiring prompt delivery and advanced real-time operation of vehicle fleets. In this paper we consider the vehicle routing problem(VRP) to minimize delivery completion time which is equal to the time that last customer wait for the vehicle in fleet operation. The mathematical formulation is different from those for the classical VRP which is minimizing cost/distance/time by running vehicles in manager's point of view. The key aspect of this model is not considering the return time from the last customer to depot in every vehicle path. Thereby, the vehicle dispatcher can afford to dynamically respond to customer demand and vehicle availability. The customer's position concerned with minimizing waiting time that may be applied for the delivery of product required freshness or delivery time. Extensive experiments are carried out to compare the performance of minimizing delivery completion time by using the ILOG Solver which has the advantage of solving quickly an interim solution very near an optimal solution. The experimental results show that the suggested model can easily find near optimal solution in a reasonable computational time under the various combination of customers and vehicles.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.1
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• pp.36-41
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• 2011

Configuration space(C-space) including configuration obstacle(C-obstacle) is one of the most important concepts in mobile robot path planning. Using C-space and C-obstacles, the robot with different shapes and moving mechanisms can be considered as a point in the C-space. And, as a result, the collision-free path for the robot can be easily achieved. To make C-space including C-obstacle, many researchers used circular approximation method for the efficient caluculation time. This method can help us to save our time by approximating the shape of a robot as the minimum sized circle which can cover all the area of robot. But, by using the circle larger than the robot, more space are considered as the part of robot and, as a result, some obstacles which are very near each other may be considered as a combined one obstacle. To solve this problem, multi-level configuration space is proposed by this paper. This multi-level method also use the circular approximation method as the initial step. But, after finding the initial path, it will check how many obstacles are combined. And then, for each combined obstacle, more accurate C-space generation will be continued. To check the efficiency of the proposed algorithm, time for c-space generation are compared with the well-known accurate C-space generation method using various types of robot shape.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.04a
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• pp.759-760
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• 2017

현재 국내 인구수가 약 5000만, 차량대수는 인구수의 절반가까이에 해당하는 2100만대를 넘어서고 있다. 이에 따라 국내 교통 혼잡도는 도로를 넓히고 대중교통을 장려하는 등의 노력을 기울이고 있음에도 증가하고 있다. 교통 혼잡도가 증가함에 따라, 사건 사고를 처리하는 응급차량의 이동이 수월하지 않은 편이다. 1분1초가 중요한 응급차량의 교통을 수월하게 하기 위해 고속도로에 갓길을 설치하는 등의 노력은 하고 있지만, 이것을 일반차량이 이용해도 제재수단이 없어 실효성이 부족하다. 이에 본 논문에서는 gps(네비게이션)를 이용하여 응급차량의 경로를 입력받았을 때 경로상의 차량에게 응급차량이 지나간다는 신호를 보내 사전에 응급차량이 지나갈 수 있는 도로를 확보하여 응급차량이 이동하는 시간을 단축시키는 것을 목적으로 한 시스템이다.

• Journal of the Korea Society of Computer and Information
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• v.3 no.2
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• pp.105-112
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• 1998

In this paper, we propose a ESP(Extended Scan Path) architecture for multi-board testing. The conventional architectures for board testing are single scan path and multi-scan path. In the single scan path architecture, the scan path for test data is just one chain. If the scan path is faulty due to short or open, the test data is not valid. In the multi-scan path architecture, there are additional signals in multi-board testing. So conventional architectures are not adopted to multi-board testing. In the case of the ESP architecture, even though scan path is either short or open, it doesn't affect remaining other scan paths. As a result of executing parallel BIST and IEEE 1149.1 boundary scan test by using the proposed ESP architecture, we observed that the test time is short compared with the single scan path architecture. By comparing the ESP architecture with single scan path responding to independency of scan path, test time and with multi-scan path responding to signal, synchronization, we showed that the architecture has improved results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.7B
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• pp.550-556
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• 2008

Swam intelligence refers that a large group of simple and unsophisticated entities work together to achieve complex and significant tasks. Researches using such swarm intelligence has been performed in the network routing area. Expecially, it has been well known that routing in mobile ad-hoc networks whose features are dynamic topology and routing based on the local information is one of the applications of swarm intelligence. In this paper, we propose an ant-based routing method for MANET. The proposed method sets its goals to reduce overheads by managing ants efficiently, and to reduce route set up time. The results obtained from simulations proved that the proposed method provides shorter path set-up time and end-to-end delay and less overhead while providing comparable packet delivery ratio.

• KIISE Transactions on Computing Practices
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• v.23 no.2
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• pp.116-121
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• 2017

In wireless sensor networks, the multipath prefers energy efficient routing method due to the characteristic of low-power sensor which uses geographic method to transmit data packet through information of the neighbor nodes. However, when multipath meets the routing fail area called hole area, path overlap problem can occur, resulting in failed maintenance of disjoint multipath. To solve this problem, multipath research studies have been performed to exploit the modeling and detouring method in routing fail area by keeping the disjoint multipath. However, in an energy point of view, additional method like modeling can lead to a lot of energy consumption of sensor node. Moreover, lots of energy consumption of sensor node can shorten the life span of sensor network. In this study, we proposed an energy efficient geographic routing by keeping the disjoint multipath in routing fail area. The proposed scheme exploited the face routing using the geographic recovery method without additional method like modeling.

• Journal of Chest Surgery
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• v.31 no.7
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• pp.703-710
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• 1998

We treated 654 patients with simultaneous bilateral sympathectomy for essential hyperhidrosis from March 1989 to September 1997(354 males and 300 females). The exposure afforded by thoracoscopy is actually superior to that seen at the time of either thoracotomy or axillary thoracotomy. The use of single-lumen intubation with alternating partially collapsed lung by CO2 inflation resulted in shorter anesthesia, shorter operative time, and shorter hospitalization. 2-mm extended thoracoscopic T2-sympathectomy is not only a time-saving method but also a very simple and effective one in the treatment of hyperhidrosis by experienced surgeons. The modification on our technique of thoracoscopic sympathectomy as described allowed us to significantly improve our previous results. A majority of the patients were relieved, and over 95% were satisfied initially.

• Journal of Chest Surgery
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• v.35 no.11
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• pp.773-778
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• 2002

Surgery remains the main stay in the treatment of carcinoma of the esophagus and the results of surgery for esophageal cancer have improved over the past 10 years. The ideal operation for cancer of the esophagus should have good palliation, low morbidity and mortality, and optimize both long-term function and survival. The two main approaches currently used for surgical treatment of esophageal cancer are: transthoracic esophagectomy (TTE) and transhiatal esorhagectomy(THE). The advantages of THE are low morbidity and mortality, short operating time, a short hospital stay and low interference with respiratory physiology The selection criteria for this procedure may differ but there are two situations which could clearly benefit from THE; these are epithelial and superficial submucosal lesions, particularly in cases of multiple lesions, and any resectable tumor at any stage with poor clinical status. I reviewed the selection criteria, surgical procedures, and results of THE in esophageal cancer with the literatures.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.3A
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• pp.219-224
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• 2008

In the c-DSDV routing protocol proposed to improve the scalability of DSDV, clusterheads manage a routing table that has only clusterheads as potential destinations and flood update request message to its neighbor clusterheads periodically or at the time of topology change. Accordingly, the convergence range of topology change by a single update request message was expanded nine times as wide as that of DSDV, increasing routing correctness; however, c-DSDV suffers from the congestion of clusterheads since data packets always go through clusterheads of the clusters on the routing path. To improve this problem, we propose an adaptive routing scheme that judges if detouring clusterhead is possible on the fly while packets are forwarded. As a result, a routing path length is shortened and an end-to-end delay is improved by the reduced queue length. It shows that the end-to-end delay is reduced by almost 40% through simulation.

• Journal of the Korean Arthroscopy Society
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• v.11 no.1
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• pp.59-62
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• 2007

Freiberg disease is a relatively rare osteochondrosis of metatarsal head, which usually involves the 2nd metatarsal of adolescent females. Various open surgical treatments have been recommended; arthrotomy and removal of loose body, dorsiflexion osteotomy and resection of the metatarsal head. Arthroscopic treatment for Freiberg disease has a merit of shortening the recovery period and reducing the postoperative stiffness. We report a case of early stage Freiberg disease treated with metatarsophalangeal arthroscopic excision of loose body and debridement of the 2nd metatarsophalangeal joint.