• Journal of Korean Institute of Industrial Engineers
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• v.12 no.1
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• pp.19-30
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• 1986

This paper provides an evaluation of static flowshop scheduling heuristics for minimizing makespan as an objective function in the dynamic flowshop model, in which new jobs with stochastic processing times arrive at the shop randomly over time and are added into the waiting jobs for processing. A total of sixteen scheduling heuristics, including several revisions and combinations of previously reported me-sixteen scheduling heuristics, including several revisions and combinations of previously reported methods, are surmmarized. These scheduling rules are evaluated via computer using a SLAM discrete event simulation model. The results for the simulation are analyzed using both statistical and nonstatistical methods. The results from the study suggest which of the popular scheduling rules hold promise for application to practical dynamic flowshop problems.

• Journal of Korean Institute of Industrial Engineers
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• v.19 no.3
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• pp.91-102
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• 1993

This paper suggests an approach to quantitative evaluation of a manufacturing flexibility in automated manufacturing systems. The flexibility of a cell is newly defined and evaluated in use of the environmental change factors which may influence flexibility for satisfying a manufacturing performance objective. The number of machines, the number of operations, machine breakdowns and processing times are considered for this cell flexibility measure. The cell flexibility measures the extent that the cell utilizes the processes to acquire high throughput. Simulation program written in SLAM System was used to help measure cell flexibility. The proposed cell flexibility measure provides a prediction of the influence of the factors on throughput performance, and applies in case of comparison of existing system and a new system, changes in operation conditions of a cell, and comparison of rival machines. Therefore it can be used as decision making criteria for system justification.

• Journal of Korean Port Research
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• v.14 no.1
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• pp.27-35
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• 2000

In Pusan Harbour, new port development projects are implemented such as the Extended Terminal adjacent to the Gamman Terminal, Pusan New Port, the Navy $\bigcirc$$\bigcirc$ piers, etc. which will require new marine traffic environments in the Passage I of Pusan Harbour. Specially, the turning basin of the Extended Terminal adjacent to the Gamman Terminal has been designed to overlay the Passage I of Pusan Harbour, which will interrupt the inbound traffic flow and the results will be worried to decrease the efficiency of port operation. Therefore, this paper will be aimed to evaluate the traffic congestion in the Pusan Passage I due to the opening of new ports within Pusan Harbour in 2006 and 2011 by using computer simulation based the queueing theory.

• The Journal of Korea Robotics Society
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• v.9 no.3
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• pp.170-177
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• 2014

This paper proposes a novel upward-looking camera-based global localization using a ceiling image map. The ceiling images obtained through the SLAM process are integrated into the ceiling image map using a particle filter. Global localization is performed by matching the ceiling image map with the current ceiling image using SURF keypoint correspondences. The robot pose is then estimated by the coordinate transformation from the ceiling image map to the global coordinate system. A series of experiments show that the proposed method is robust in real environments.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.524-526
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• 2006

We proposes integrated information system, Service Robot Information System(SRIS), for mobile robot. The system has objectives that can heir efficient management and sharing as support information for mobile service robot like recognition, navigation, manipulation and modeling. This paper introduces the concert and architecture of SRIS. An Implementation is done by using ER based database and CAD modeling which is DXF format. The experimental shows the result of object and environment map matching by SLAM. This system is expected that can help reduce the cost and efforts of information management under multiple mobile robot environment.

• Journal of the Korea Society for Simulation
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• v.3 no.2
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• pp.49-56
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• 1994

Performance measurement and analysis for computer systems has been studied for a long time. However, little attention has been focused on how to distribute a given budget to each part of a computer system for enhancing system performance maximally. In traditional approaches, performance enhancement is achieved by identifying a dominant system bottleneck and enhancing the bottleneck's performance. These approaches, however, often bring problems since the removal of a bottleneck may result in other bottlenecks. This paper proposes an approximated method for such budget distribution problem. For budget distribution, a critical set is defined. The set contains the servers of which performance changes affect the overall system performance significantly. Then, the given budget is distributed properly to every server in the critical set. To verify the proposed method, two benchmark experiments are carried out I SLAM environments. The experimental results show that the proposed method provides better results than the traditional method does in many cases.

• Journal of the Korea Society for Simulation
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• v.3 no.1
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• pp.29-42
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• 1994

The architecture of a MIMD-type parallel computer system is specified: a simulator is developed to support design and evaluation of systems based on the architecture: and conducted with the simulator to evaluate system performance. The horizontal/vertical-bus(H/V-bus) system architecture provides an NxN array of processing elements which communicate with each other through a network of N horizontal buses and N vertical buses. The simulator, written in SLAM II and FORTRAN, is designed to provide high-resolution in simulating the IPC mechanism. Parameters provide the user with independent control of system size, PE speed and IPC mechanism speed. Results generated by the simulator include execution times, PE utilizations, queue lengths, and other data. The simulator is used to study system performance when a partial differential equation is solved by parallel Gauss-Seidel method. For comparisons, the benchmark is also executed on a single-bus system simulator that is derived from the H/V-bus system simulator. The benchmark is also solved on a single PE to obtain data for computing speedups. An extensive analysis of results is presented.

• Journal of the Korea Society for Simulation
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• v.3 no.1
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• pp.89-98
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• 1994

In this paper, a criteria for selecting an appropriate load redistribution algorithm is devised so that a fault-tolerance distributed system can operte at its optimal efficience. To present the guideline for selecting redistributing algorithms, simulation models of fault-tolerant system including redistribution algorithms are developed using SLAM II. The job arrival rate, service rate, failure and repair rate of nodes, and communication delay time due to load migration are used as parameters of simulation. The result of simulation shows that the job arrival rate and the failure rate of nodes are not deciding factors in affecting the relative efficiency of algorithms. Algorithm B shows relatively a consistent performance under various environments, although its performance is between those of other algorithms. If the communication delay time is longer than average job processing time, the performance of algorithm B is better than others. If the repair rate is relatively small or communication delay time is longer than service time, algorithm A leads to good performance. But in opposite environments, algorithm C is superior to other algorithms.

• Journal of the Korea Society for Simulation
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• v.4 no.1
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• pp.59-73
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• 1995

Local area networks(LANs) recently become so large that they exceed their architected limits and users on different LANs may need to talk each other. This trend has led to a growth in the practice of interconnecting many heterogeneous LANs. In this paper, we proposed a method to interconnect Ethernets and token rings, which are widely used today, through a fast FDDI network. We also developed a simulation tool to evaluate the performances of the interconnected networks. We used a simulation language SLAM II for modeling and OSF/MOTIF X-window for user interface. The developed tool can be used to make a decision which interconnecting method is suitable for a given environment before interconnecting many heterogeneous LANs.

• Journal of Korean Society of Transportation
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• v.4 no.2
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• pp.3-14
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• 1986

This study was undertaken to develop the gap acceptance model of left-turn drivers on the major road at intersections. Typical unsignalized intersections on the two-lane and four-lane streets in Masan City were selected for the study intersection. For the gap distribution model, the lognormal, negative exponential, shifted negative exponential, and Gamma distributions were tested using the x2 and K-S tests. Based on the results for both streets, it was concluded that among the distributions tested the lognormal distribution represented the gap distribution best, followed by the shifted negative exponential distribution. Stochastic models of the gap-acceptance behavior of left-turn drivers on the major road at unsignalized intersections were programmed using SLAM Ⅱ, a simulation computer language. A stochastic model was selected for the gap-acceptance behavior to compare the results of the simulation with the observed data. The model assumes that a fixed critical acceptance gap is assigned to each left-turn driver based on a normal distribution and the gap distribution of the opposing traffic stream follows the shifted negative exponential distribution.