• Journal of Korean Institute of Industrial Engineers
• /
• v.33 no.2
• /
• pp.282-289
• /
• 2007

While demands for express couriers service are rapidly increasing due to recent progress of electronic commerce, express courier service companies are struggling to take a larger market share through ongoing improvement in their service processes. Cut-off time is the time limit that all orders delivered before the limit are guaranteed for the delivery within the very next day. Extending cut-off time for express service centers can provide the express company with increase of total sales, but it may also cause increasing the possibility not to satisfy customer needs due to work delay in the consolidation terminal. We develop a design model for express courier service network based on a recursive optimization/simulation procedure. With the optimization model, we seek key design parameters such as the cut-off time for express service centers and the capacity of the consolidation terminal maximizing total sales profit while satisfying the desired level of performances. With the simulation model, we consider the dynamic nature of the network and obtain relationships between the design parameters and the performance measures with the multiple linear regression. The validity of the model is examined with an example.

• Journal of the Korean Society of Safety
• /
• v.30 no.4
• /
• pp.56-63
• /
• 2015

Gas explosion accidents could cause a catastrophe. we need specialized and systematic accident investigation techniques to shed light on the cause and prevent similar accidents. In this study, we had performed LNG explosion simulation using AUTODYN which is the commercial explosion program and predicted the damage characteristics of the structures by LNG explosive power. In the first step, we could get LNG's physical and chemical explosion properties by calculation using TNT equivalency method. And then, by applying TNT equivalency value about the explosion limit concentration of LNG on the 2D-AUTODYN simulation, we could get the explosion pressure wave profiles (explosion pressure, explosion velocity, etc.). In the last step, we performed LNG explosion simulation by applying to the explosion pressure wave profiles as the input data on the 3D-AUTODYN simulation. As a result, we had performed analyzing of the explosion characteristics of LNG in accordance with concentration through the 3D-AUTODYN simulation in terms of the explosion pressure behavior and structure's destruction and damage behavior.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.5
• /
• pp.1160-1167
• /
• 2013

Web based simulation service is utilized to computationally analyze various phenomena in real world according to the progress of network and computing technology. In this paper, we present an improvement and utilization of e-AIRS (e-Science Aerospace Integrated Research System). e-AIRS, has been utilized to support web based CFD simulation service since 2008. has some problems such as stable system, pre processing, post processing. To solver this problem, we improved e-AIRS such as distributed service processing, personal simulation job assignment control, and faster data loading. After improvement, although users increase from 110 to 606, the priority of user requirements is changed from stable system to pre/post processor. User requirements and statistics about e-AIRS simulation service for each semester is analyzed to support more stable and comfortable service.

• 한국IT서비스학회:학술대회논문집
• /
• 2009.11a
• /
• pp.380-383
• /
• 2009

최근 서비스사이언스에 대한 관심이 높아지면서 서비스 사이언스에 기초하면 다양한 서비스들이 제공되어지고 있다. 다양한 서비스 산업에서 IT기술을 적용하여 서비스의 제공시 실제 필요한 자원과 서비스로 인해서 얻어지는 수익에 대해서 시뮬레이션을 통해서 검증하기 위한 Service Simulation을 자바기반의JSL(Java Simulation Library)과 Tortuga 를 이용하여 Event Simulator를 구현하였다. 본 논문에서 General Service Simulation에 대한 요건을 분석하고, 이를 기반으로 한 Event Simulator의 구현을 소개하였다.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2005.05a
• /
• pp.1033-1039
• /
• 2005

Parallel and distributed simulation is concerned with the efficient execution of large-scale discrete event simulation models on multiprocessors and distributed platforms. After the development of WWW, many efforts in the parallel and distributed simulation have been made for modeling, particularly building simulation languages and creating model libraries that can be assembled and executed over WWW. However, web-based parallel and distributed simulation is restricted by heterogeneous computing environments. Recently, the advent of XML and web services technology has made these efforts enter upon a new phase. Especially, the web services as a distributed information technology have demonstrated powerful capabilities for scalable interoperation of heterogeneous systems. This paper aims to develop and evaluate the parallel and distributed simulation using the web services technology. In particular, a prototype multi-pass simulation framework is implemented using Java-based web services technology. It focuses on the efficiency of multi-pass simulation used for optimization through the distribution of simulation replication to several simulation service providers. The development of parallel and distributed simulation using web services will help solve efficiently large-scale problems and also guarantee interoperability among heterogeneous networked systems.

• Journal of Internet Computing and Services
• /
• v.19 no.3
• /
• pp.57-66
• /
• 2018

EDISON ( EDucation-research Integration through Simulation On the Net) is a web simulation service based on cloud compu-ting. EDISON provides that web service and provide analysis result to users through pre-built infrastructure and various calcu-lation nodes computational science engineering problems that are difficult or impossible to analysis as user's personal resources to users. As a result, a simulation execution environment is provided in a web portal environment so that EDISON can be ac-cessed regardless of a user's device or operating system to perform computational science engineering analysis simulation. The purpose of this research is to design and construct a workbench based real - time dynamic service to provide an integrat-ed user interface to the EDSION system, which is a computational science engineering simulation and analysis platform, which is currently provided to users. We also devised a workbench-based user simulation service environment configuration. That has a user interface that is similar to the computational science engineering simulation software environment used locally. It can configure a dynamic web environment such as various analyzers, preprocessors, and simulation software. In order to provide these web services, the service required by the user is configured in portlet units, and as a result, the simulation service using the workbench is constructed.

• Proceedings of the IEEK Conference
• /
• 2004.08c
• /
• pp.549-551
• /
• 2004

This paper used OPNET to simulate video streaming service a test IP network and MPLS network with the traffic shaping that have with CQ_ LLQ algorithm, LSP of fixed bandwidth, policy of limitation users and measures parameters such as delay, throughput, packet loss. To verify the performance of video streaming service in IP network and MPLS network, two scenario that have same topology and traffic source. One is the simulation for best-effort service in pure IP network. The other is the simulation for QoS-enabled service in MPLS Network. Based on simulation result, the MPLS network with CQ_ LLQ algorithm and fixed LSP show advantage of the video streaming service QoS, specially delay and packet loss

• Journal of the Korea Society for Simulation
• /
• v.9 no.1
• /
• pp.11-19
• /
• 2000

The main idea behind the Intelligent Networks (IN) concept is the separation of switching function from the service control, in order to meet various service requirements of subscribers and development of new services in time. The (N+l) architecture of the IN service system consists of front-end processors (FEP) and back-end processors (BEP), which is in service in a domestic telecommunication company, and balances the traffic load for services among the processors. Under this architecture, the IN service system can distribute the traffic load dynamically, and M services are easily launched and manipulated minimizing impacts on the existing services. This paper traces the performance of the (N＋1) structured system by means of the simulation approach, and shed a light on the result.

• Journal of the Korea Society for Simulation
• /
• v.12 no.4
• /
• pp.103-111
• /
• 2003

A distributed sewer cluster system is a cost-effective system to provide a service application for clients with reliable, scalable, available, and fault-tolerant features. In order to provide high quality services, it is necessary to evaluate service performances, tune the server system, and analyze performances. In this paper, we propose a simulator to generate workloads based on statistic configuration according to estimated application traffics, apply workload scheduling algorithms, and evaluate the simulation results. We introduce the simulator design modelling and architecture. By using flexible parameters, the simulator is able to generate various patterns of workloads with different statistics, and configure system environments such as the number of server nodes, system resources considered, and their capacities. With this simulator, we introduce two scenarios: one is to find appropriate thresholds for the best performance of cluster system, and the other is to find the suitable scheduling algorithm for workload characteristics of service applications.

• Journal of the Korea Society for Simulation
• /
• v.12 no.4
• /
• pp.61-71
• /
• 2003

Recently, a matter of the highest priority that the company must do for the satisfaction of customer service is that the company ensure the competitive power throughout the strategic cooperation in the market environment changing rapidly In this situation, one of allied strategies is the supply chain management and the outsourcing is one of the supply chain management strategies. In this paper, the inventory sharing system is introduced as the method to solve two inconsistency problem such as inventory and customer service. This paper also suggests how to increase customer service and to decrease inventory throughout construction of the inventory sharing system among outsourcing companies. For this, we experimented the effect of the inventory sharing system on the supply chain dynamics by using the simulation modeling and analyzed the validity about construction of the inventory sharing system presented in this study. The simulation is designed by Vensim(Process simulation package) and has some feedback loops.