• Management Science and Financial Engineering
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• v.8 no.2
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• pp.33-45
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• 2002

This study suggests an approach for determining fleet size for LTL (less -than-truckload) transportation with dynamic demand for on-time supply of the parts between the assembly line in an automobile company and its part suppliers in Korea. The vehicles operated by the transportation trucking companies in Korea in general can be classified into three types depending on the ways how their expenses occur; company -owned truck, mandated truck which is owned by outsider who entrusts the company with its operation, and rented truck (outsourcing) . With the forecasted monthly production data a year, a heuristic algorithm is developed to determine the number of company-owned trucks, mandated trucks, and rented trucks in order to minimize the expected annual operating cost, which is based on the solution technologies used in the aggregate production planning and vehicle routing problem. Finally the algorithm is tested for the problem how the trucking company transports parts for the automobile company.

• IE interfaces
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• v.13 no.3
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• pp.462-470
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• 2000

This paper is concerned with a vehicle routing model to assist in scheduling palletized cargo pickup and delivery so called the pickup and delivery problem with advance requests in a 2-echelon supply-chain system. In this study vehicles is dispatched and routed so that each request is picked up or delivered at its original and to its destination. The model provides point-to-point transportations based on advance requests. The assignment algorithm is developed and designed for using with on-line computers and it immediately provides arrangements to be made at the time requested. This algorithm also provides the best scheduling solutions and alternatives for both to system operators and requesters. According to this algorithm, we developed computer programs and show the sample results.

• Journal of KIISE:Information Networking
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• v.29 no.1
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• pp.40-47
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• 2002

This paper analyzes the performance of an optical line termination system in ATM based Passive Optical Network(PON) using the operational analysis. We analyze it using system parameters such as utilization, throughput and routing frequency based on the buffer structure in each block of ATM-PON. Furthermore, we derive the mean response time and the visit ratio of each block, and then search the bottleneck block that hinders the system performance. We found that the 622Mbps 16x16 switching block is the bottleneck block for ATM-PON. In this bottleneck block, the loss probability increases rapidly when the cell arrival rate increases.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.9
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• pp.1649-1654
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• 2017

The route request (RREQ) packet of the GAODV is propagated in a unicast-manner using the location of the destination, but the application of the GAODV is restricted by the assumption for the known destination's location. In this paper, we propose a virtual destination aided GAODV (VDA-GAODV) that alleviates the uncertainty of the destination's location due to the mobility. Instead of the known location of the destination, the VDA-GAODV disseminates a RREQ packet to an imaginary location on the line connecting the source and the destination. We derive an optimal imaginary destination that makes RREQ rebroadcasts cover the possible locations of the destination as much as possible. The VDA-GAODV enables the RREQ propagation to cover 95 % of the one-hop communication area centered at the originally known location of the destination, which is larger than that of the original GAODV by 23 %.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.563-566
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• 2006

In this paper, we studied about AGVs modeling and material handling automation simulation using a virtual AGV. The proposed virtual AGV model that operates independently each other is based on a real AGV. Continuous straight-line and workstation model using vector drawing method that could easily, rapidly work system modeling are suggested. Centralized traffic control, which could collision avoidance in intersection and should not stop AGV as possible, and algorithm for detour routing which performs when another AGV is working in pre-routed path are proposed. The traffic control and the algorithm have been proved efficiently by simulation.

• Journal of Auto-vehicle Safety Association
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• v.7 no.1
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• pp.13-19
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• 2015

Recently, Child safety has become one of the issue with Q10 dummy representing large child. The objective of this paper was to evaluate performance of three child restraints system (backless booster, high-back booster and without booster) by changing D-ring location in the rear seat. Sled tests were carried out with a Q 10 in 64km/h frontal impact. Before the dynamic sled tests, we assessed dummy positioning with difference in CRS types and height adjustment positions. Dynamic sled test results indicated that there is different performance of CRS types and belt routing. These test results will use as base line data for development CRS safety performance for Q 10.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.1 s.232
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• pp.96-106
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• 2005

An integrated single-wafer processing tool, composed of multiple single wafer processing modules, transfer robots, and load locks, has complex routing sequences, and often has critical post-processing residency constraints. Scheduling of these tools is an intricate problem, and testing schedulers with actual tools requires too much time and cost. The Single Wafer Processor (SWP) simulator presented in this paper is to validate an on-line scheduler, and evaluate performance of integrated single-wafer processing tools before the scheduler is actually deployed into real systems. The data transfer between the scheduler and the simulator is carried out with TCP/IP communication using messages and files. The developed simulator consists of six modules, i.e., GUI (Graphic User Interface), emulators, execution system, module managers, analyzer, and 3D animator. The overall framework is built using Microsoft Visual C++, and the animator is embodied using OpenGL API (Application Programming Interface).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.6
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• pp.1096-1101
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• 2004

By a tremendous expansion of Internet users, there's a number effects that cause the phenomenon of bottlenecked switching packets from routers. In order to tear down this problem, distributed system is applicable to almost every highly performed router systems. The main processor of distributed system, which manages routing table, commands IPC to delivering the forwarding table line processor that eases functionalities of the router. This makes the system having wired-speed forwarding function based on the hardware so that the performance of the network can be enhanced. Therefore, IPC, which assign a part of router, is necessary to exchange data smoothly and the constitution of IPC using Ethernet is widely adapted as a method for saving investment. In this paper, R-IPC mechanism improve the packet-processing rate over 10% through changed from defect of conventional Ethernet IPC, that is, 2 layer processing to TCP/IP or UDP/ IP into 1 layer processing for efficient packet forwarding.

• Fire Science and Engineering
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• v.23 no.6
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• pp.75-81
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• 2009

In this paper, USN of wireless communication with easy to install and effectiveness with variety information gathering has been proposed as a alternative of wired-based line for transmission of fire sensing data. But, The sensor node using USN should be considered for wireless transmission range and reliability of information. In this study, the zigbee protocol sensor node was implemented and then tested transmission range of sensor node as 10m interval using voltage information of DC 3V & 5V. Here, maximum transmission distance was confirmed 90m inside-outside. When used mesh routing relay node, distance was not limited. In USN network building, when fire sensing data transmitted, the sensing data same between direct sensing data from sensor and collecting data at USN. Therefore, was confirmed reliability for transmission range and information of proposed zigbee sensor node.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.862-866
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• 2005

For urban watershed models, the ILLUDAS and SWMM are the popular rainfall-runoff models used in Korea. However, combined sewage systems in urban areas produced problems when a flood occured because of the surcharged precipitation amount which drained to the streams directly. Also, the lack of pipe line data and the difficulties of modeling yield inappropriate modeling results in urban runoff analysis. In addition, rainfall-runoff models in urban areas which use channel routing could have inaccurate and complicated processes. In this paper, the MIKE SWMM model has been applied for the stable runoff analysis of urban areas. Watershed and pipe line data were established by using past inundated records, DEM data, and the numerical pipe line data. For runoff modelings, the runoff block was adapted to a basin and the Extran block using dynamic equations was applied to the sewage system. After comparing to models that exist, it is concluded that the MIKE SWMM model produces reliable and consistence results without distorting the Parameters of the model.