• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.5
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• pp.11-18
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• 2004

In this paper, we propose the alternative LSP allocation for MPLS networks required more confidence. In the first place, we must classify the user traffics by the QoS parameter. We assigned altermative LSPs on realtime traffics and then allocated alternative LSPs of non-realtime traffics. The proposed algorithm can provide more confidential alternative LSP by priority method for relatively high cost realtime traffic error. And the proposed algorithm can improve the shortage of network resources what is occured by using a few links when altermative LSPs are setup. The validity of the proposed algorithm has been justified in performance by analysis through simulation results using the program tool and comparison with conventional methods. Also, that improves 9% more than existing method in the recovery ratio-one is 89%, the other is 98%, respectively.

• Journal of Korea Multimedia Society
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• v.19 no.4
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• pp.689-705
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• 2016

This paper proposed an realtime total monitoring platform for various kind of multi weather radars to analyze and predict weather phenomenons and prevent meteorological disasters. Our platform is designed to process each weather radar data on each radar site to minimize overloads from conversion and transmission of large volumed radar data, and to set observers up the definitive radar data via public framework server separately. By proposed method, weather radar data having different spatial or temporal resolutions can be automatically synchronized with there own spatio-temporal domains on public GIS platform having only one spatio-temporal criterion. Simulation result shows that our method facilitates the realtime weather monitoring from weather radars having various spatio-temporal resolutions without other data synchronization or assimilation processes. Moreover, since this platform doesn't require some additional computer equipments or high-technical mechanisms it has economic efficiency for it's systemic constructions.

• Proceedings of the Korea Society for Simulation Conference
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• 1996.05a
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• pp.15-15
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• 1996

A shop floor control system (SFCS) is the central part of a CIM system used to control the activities of several pieces of manufacturing equipment (e.g., NC machines, robots, conveyors, AGVs, AS/RS). The SFCS receives orders and related process plans, and then performs selecting a specific process routing, allocating resources, scheduling the workpieces, downloading the processing instructions (e.g., RS-274 instructions for NC machines, VAL II programs for robot), monitoring the progress of activities, detecting and recovering from errors, and preparing reports on the status of the manufacturing system. Simulation has been utilized in discovering control policies used for resolving shop floor be control problems such as resource contentions, part dispatching, deadlock. The simulation model must be designed to respond to real-time data coming from a shop floor. However, to rapidly build a realtime simulation model of SFCS cannot be easily accomplished. This talk is to address an automatic program generator of discrete event simulation model for shop floor control from process plans and resource models. The program generator is capable of constructing complete discrete simulation models for multi-product and multi-stage flexible manufacturing systems.

• Journal of Intelligence and Information Systems
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• v.6 no.1
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• pp.113-128
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• 2000

This paper presents a first year report of an ongoing multi-year project to develop a systolic parallel simulation system for dynamic traffic assignment. The fundamental approach to the simulation is systolic parallel processing based on autonomous agent modeling. Agents continuously act on their own initiatives and access to database to get the status of the simulation world. Various agents are defined in order to populate the simulation world. In particular existing modls and algorithm were incorporated in designing the behavior of relevant agents such as car-following model headway distribution Frank-Wolf algorithm and so on. Simulation is based on predetermined routes between centroids that are computed off-line by a conventional optimal path-finding algorithm. Iterating the cycles of optimization-then-simulation the proposed system will provide a realistic and valuable traffic assignment. Gangnum-Gu district in Seoul is selected for the target are for the modeling. It is expected that realtime traffic assignment services can be provided on the internet within 3 years.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.7
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• pp.1630-1638
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• 2015

In this paper, we propose a GPU-based interactive and plausible visualization method for the silt and landslide simulation results computed with SPH. By empirical experiments, we verify that our GPU-accelerated screen space mesh method can be effectively used for visualizing the landslide disaster simulation. The method proposed in this paper make it possible to overcome the limitation of previous simulations where the experience obtained by trials and errors plays the most important roles. Because the realtime visualization enables interactive observation of simulation results and efficient data assimilation, the accuracy of the simulation can be significantly improved in an efficient way.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.6
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• pp.2992-2998
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• 2013

The future mobile communication system can support not only voice but also multimedia applications such as data, image and video. It requires greater resources than the voice-oriented mobile system. We propose user and sub-channel priority based resource allocation for mobile multimedia services in the OFDMA systems. Our method is able to guarantee QoS continuity of realtime services and carry the maximum number of non-realtime subscriber. Simulation is focused on total throughput and blocking rate. The simulation results show that our proposed method provides a better performance than the conventional method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.6A
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• pp.565-572
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• 2007

3G Long Term Evolution (3G LTE) is a next generation cellular networks system capable or providing various mobile multimedia services by using OFDMA and MIMO based radio access technology. Among many differences from existing WCDMA based systems, the facts that 3G LTE uses Physical Resource Block (PRB) as its radio resources and provides all services through the PS domain make the development of new resource management schemes necessary. This paper proposes an adaptive partitioning based downlink call admission control scheme. It separates realtime call requests from non-realtime ones, specifies maximum allowable resource amounts for each type, but if the maximum is exceeded, call requests are accepted with probability proportional to remaining resource amounts. Despite the fact that such adaptive concept has been already adopted by other call admission schemes, the contributions of our paper, which are that we are able to find an efficient way to apply the proposed scheme exploiting PRB characteristics and measure the resource usage of base stations by PRB utilization and payload ratio, are still valid. When judging from simulation results in comparison with others, our scheme is able to prioritize realtime call requests over non-realtime ones, and at the same time, overall system performance is superior.

• ETRI Journal
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• v.29 no.2
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• pp.201-211
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• 2007

This paper focuses on the scheduling problem with the objective of maximizing system throughput, while guaranteeing long-term quality of service (QoS) constraints for non-realtime data users and short-term QoS constraints for realtime multimedia users in multiclass service high-speed uplink packet access (HSUPA) systems. After studying the feasible rate region for multiclass service HSUPA systems, we formulate this scheduling problem and propose a multi-constraints HSUPA opportunistic scheduling (MHOS) algorithm to solve this problem. The MHOS algorithm selects the optimal subset of users for transmission at each time slot to maximize system throughput, while guaranteeing the different constraints. The selection is made according to channel condition, feasible rate region, and user weights, which are adjusted by stochastic approximation algorithms to guarantee the different QoS constraints at different time scales. Simulation results show that the proposed MHOS algorithm guarantees QoS constraints, and achieves high system throughput.

• Journal of Hydrogen and New Energy
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• v.29 no.2
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• pp.226-234
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• 2018

Even though the nuclear power plants has many advantages, safety issues of nuclear power plants are crucial factors of reliable operation. A tritium detector is a useful sensor to analyze amount of exposed radiation from the nuclear power plants. Currently, concentration of underwater tritium is measured precisely but it takes very long time. Since electrolysis is extracted hydrogen from the coolant of nuclear power plant, it can motivate to develop new type of real-time sensor. In this study, Proton Exchange Membrane (PEM) electrolyzer is studied for candidate as preprocessor of real-time tritium detector. Characteristics of the unit PEM electrolyzer were experimentally investigated. A simulation model is developed to understand physical behavior of unit PEM electrolyzer under dynamic operation.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.544-547
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• 1999

This paper proposes a high-speed texture mapping algorithm and apply it for the realtime face animation. The mapping process devide into pixel correspondences, Z-buffering, and pixel value interpolation. Pixel correspondences and Z-buffering are calculated exactly through the algorithm. However, pixel values interpolation is approximated without additional calculations. The algorithm dramatically reduces the operations needed for texture mapping. Only three additions are needed in calculation of a pixel value. We simulate the 256$\times$240 pixel facial image with about 100 pixel face width. Simulation results shows that frame generation speed are about 60, 44, 21 frames/second in pentium PC 550MHz, 400MHz, 200MHz, respectively,