• Journal of the Korea Society for Simulation
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• v.12 no.4
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• pp.83-94
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• 2003

Managing a call center is a complex and diverse challenge. Call center becomes a very important contact point and a data ware house for successful CRM. Improving performance of call center is critical and valuable for providing better service. In this study we applied forecasting technique to estimate incoming calls and ProModel based simulation model to enhance performance of a mobile telecommunication company's call center. The simulation study shows reduction in managing cost and better customer's satisfaction.

• Journal of IKEEE
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• v.24 no.2
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• pp.426-434
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• 2020

FMI is being researched as a standard for linking large-scale simulation of CPS. In order to guarantee the reliability of the results in large-scale simulations using FMI, event handling through time management techniques is required. This paper aims to guarantee real-time performance and accuracy in large-scale co-simulation environments such as CPS. Synchronize the wallclock time and simulation time to ensure real time. Also, to ensure the accuracy, before the simulation, the event is checked and the simulation is performed with the smallest step size while maintaining the real time until the event occurrence time. As a result, the events occurring in the co-simulation environment are processed immediately and sequentially, ensuring the real-time performance and minimizing the numerical integration error by maximizing the simulation resolution. In the experiment, the proposed method was processed immediately, and it was confirmed that the numerical integration error is reduced by about 1/5 unlike the existing time management method which does not guarantee the resolution.

• The Journal of Korean Academic Society of Nursing Education
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• v.25 no.3
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• pp.331-343
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• 2019

Purpose: This study focuses on investigating the effectiveness of simulation education on emergency management using a low-fidelity simulator as related to clinical skill performance, self-confidence, knowledge, learning satisfaction, and critical thinking disposition in new nurses. Methods: A pre-post test experimental design of nonequivalent control group was applied. Fifty-five new nurses were recruited, 28 nurses for the experimental group and 27 nurses for the control group. A simulation education for emergency management comprising knowledge lecture, team learning, skill education, team simulation, and debriefing was developed and implemented from Feb. 14 to 27, 2015. Data were analyzed with percentage, average, and standard deviation, chi-square, and t-test using SPSS. Results: The experimental group showed significantly higher knowledge (t=5.81, p<.001), clinical skill performance (t=10.08, p<.001), self-confidence (t=-6.24, p<.001), critical thinking disposition (t=2.42, p=.019), and learning satisfaction (t=4.21, p<.001) for emergency management compared with the control group who had traditional lecture education. Conclusion: The results indicate that a simulation education using a low-fidelity simulator is an efficient teaching method for new nurses to deepen their clinical skill performance, self-confidence, knowledge, learning satisfaction, and critical thinking disposition in learning emergency management.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.4
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• pp.323-329
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• 2012

A thermal management system of a proton exchange membrane fuel cell is taken charge of controlling the temperature of fuel cell stack by rejection of electrochemically reacted heat. Two major components of thermal management system are heat exchanger and pump which determines required amount of heat. Since the performance and durability of PEMFC system is sensitive to the operating temperature and temperature distribution inside the stack, it is necessary to control the thermal management system properly under guidance of operating strategy. The control study of the thermal management system is able to be boosted up with hardware in the loop simulation which directly connects the plant simulation with real hardware components. In this study, the plant simulation of fuel cell stack has been developed and the simulation model is connected with virtual data acquisition system. And HIL simulator has been developed to control the coolant supply system for the study of PEMFC thermal management system. The virtual data acquisition system and the HIL simulator are developed under LabVIEWTM Platform and the Simulation interface toolkit integrates the fuel cell plant simulator with the virtual DAQ display and HIL simulator.

• Journal of Korea Water Resources Association
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• v.46 no.4
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• pp.373-387
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• 2013

For the efficient operation and management of the water resources system, coordinated operation of weirs and reservoirs is required. A simulation based, and an optimization based approaches are available to deal with the operation and management problems. The simulation based approach does not guarantee an optimal solution, and the optimization based approach is not so flexible to consider, complex, nonlinear problems we will face when trying to allocate water to different uses, various demand sectors in a basin. Hence, it is important to develop a model that would compensate for the weak points in both models. We will compare and contrast intrinsic and extrinsic properties of two modeling approaches, addressing issues related to setting system operation and control rules that would lead us to more efficient use of water in the basin. As a result, we propose to use CoWMOM(Coordinated weirs and multi-reservoir operating model), a "simulation based" optimization model for a simple simulation of the past periods, and for the real-time simulation process considering uncertain inflow.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.163-163
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• 2019

The rapidly growing global population increases the awareness of water, energy, and food security worldwide. The concept of Water, Energy, and Food nexus (hereafter, WEF nexus) has been widely introduced as a new resources management concept that integrate the water, energy, and food in a single management framework. Recently, WEF nexus analyzes not only the interconnections among the resources, but also considers the external factors (such as environment, climate change, policy, finance, etc) to enhance the resources sustainability by proper understanding of their relations. A nation-level resources management is quite complex task since multiple regions (e.g., watersheds, cities, and counties) with different characteristics are spatially interconnected and transfer the resources each other. This study proposes a multiple region WEF nexus simulation and transfer model. The model is equipped with three simulation modules, such as local nexus simulation module, regional resources transfer module, and optimal investment planning module. The model intends to determine an optimal capital investment plan (CIP), such as build-up of power plants, water/waste water treatment plants, farmland development and to determine W-E-F import/export decisions among areas. The objective is to maximize overall resources sustainability while minimize financial cost. For demonstration, the proposed model is applied to a semi-hypothetical study area with three different characterized cities. It is expected the model can be used as a decision support tool for a long-term resources management planning process.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.1 no.1
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• pp.49-53
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• 1978

Yet objective of this paper to spell out in detail the relationship between factors design techniques of data analysis and the design of simulation model of the management organization. Yet an organization is more than a collection of individuals. It is something more than the sum of its Parts: it exists as an entity with its own definable objectives. The management process comprise those activities or functions that managers must perform to effectively carry out this asizned role. However, now that O.R. and system approach has been generalized and the assembly system of hard ware or soft ware through computerization is being improved, the systematization of scientific organization is urgently needed. This paper is to set forth :he problem and solution which are most fit for the management organization in relation to computer. Procedure developed are : 1. Interpretation of the management organization. 2. Design of the computer simulation. 3. Application.

• Journal of the Korea Society for Simulation
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• v.12 no.2
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• pp.55-62
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• 2003

The explosive Increase of wireless networks and the advancement of mobile devices lead to the expansion of mobile environment. In accordance with the development of mobile environment, the need to use mobile database is increased sharply, and also it accompanies the related problems. The current mobile database system is based on the centralized method from which a synchronized server manages multiple mobile database management system to synchronize. From this mobile system architecture, several kinds of problems can be detected such as the management of synchronization issues between mobile databases and the transaction management issues. Furthermore, the current mobile database management system does not consider any solution on the fault tolerance. To solve those problems, this paper proposes the mobile agent-based mobile database management system. The proposed system provide high confidence and efficiency by enhancing the network efficiency and fault tolerance through the mobile grouping.

• International Journal of Automotive Technology
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• v.7 no.1
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• pp.25-34
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• 2006

For decades, simulation technique has been well validated in areas such as computer and communication systems. Recently, the technique has been much used in the area of transportation and traffic forecasting. Several methods have been proposed for investigating complex traffic flows. However, the dynamics of vehicles and diversities of driver characteristics have never been considered sufficiently in these methods, although they are considered important factors in traffic flow analysis. In this paper, we propose a traffic simulation tool called Multi-Agent for Traffic Simulation with Vehicle Dynamics Model (MATDYMO). Road transport consultants, traffic engineers and urban traffic control center managers are expected to use MATDYMO to efficiently simulate traffic flow. MATDYMO has four sub systems: the road management system, the vehicle motion control system, the driver management system, and the integration control system. The road management system simulates traffic flow for various traffic environments (e.g., multi-lane roads, nodes, virtual lanes, and signals); the vehicle motion control system constructs the vehicle agent by using various vehicle dynamic models; the driver management system constructs the driver agent capable of having different driving styles; and lastly, the integrated control system regulates the MATDYMO as a whole and observes the agents running in the system. The vehicle motion control system and driver management system are described in the companion paper. An interrupted and uninterrupted flow model were simulated, and the simulation results were verified by comparing them with the results from a commercial software, TRANSYT-7F. The simulation result of the uninterrupted flow model showed that the driver agent displayed human-like behavior ranging from slow and careful driving to fast and aggressive driving. The simulation of the interrupted flow model was implemented as two cases. The first case analyzed traffic flow as the traffic signals changed at different intervals and as the turning traffic volume changed. Second case analyzed the traffic flow as the traffic signals changed at different intervals and as the road length changed. The simulation results of the interrupted flow model showed that the close relationship between traffic state change and traffic signal interval.

• Proceedings of the Korea Society for Simulation Conference
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• 1994.10a
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• pp.12-12
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• 1994

Simulation output knowledge analysis is one of problem-solving and/or knowledge adquistion process by investgating the system behavior under study through simulation . This paper describes an approach to simulation outputknowldege analysis using fuzzy neural network model. A fuzzy neral network model is designed with fuzzy setsand membership functions for variables of simulation model. The relationship between input parameters and output performances of simulation model is captured as system behavior knowlege in a fuzzy neural networkmodel by training examples form simulation exepreiments. Backpropagation learning algorithms is used to encode the knowledge. The knowledge is utilized to solve problem through simulation such as system performance prodiction and goal-directed analysis. For explicit knowledge acquisition, production rules are extracted from the implicit neural network knowledge. These rules may assit in explaining the simulation results and providing knowledge base for an expert system. This approach thus enablesboth symbolic and numeric reasoning to solve problem througth simulation . We applied this approach to the design problem of broadband communication network.