• Journal of the Society of Naval Architects of Korea
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• v.53 no.1
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• pp.18-28
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• 2016

In shipbuilding, the scheduling system is susceptible to sudden changes and thus it turns to be difficult to predict the differences between schedule and production records in advance. A computer-based simulation is commonly utilized to overcome the discrepancies occurred in estimating workloads and resulting processing times. The main drawback of this simulation-based solution is its limited applicability because, in most cases, each shipyard requires specific and customized simulation environment. By standardizing the planning data of the midterm scheduling system, as proposed in this paper, the efficiency of the current simulation model can be enhanced. To present an alternative approach, this paper begins with the analysis of the complex planning data structure of several shipyards and then proceeds to construct a standard data structure based on the neutral format. An interface application is developed for the data transaction and simulation in on-line environment. As a result, a simulation-based production management of shipyards can be achieved by the efficient prediction of planning and scheduling.

• Water for future
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• v.13 no.4
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• pp.41-50
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• 1980

The prupose of this study are the theoretical examination of Gamma distribution function and its application to hydraulic engineering, that is studying the simulation of monthly streamflow by the Gamma distribtution function model(Gamma Model) based on Monte Carlo technique. In the analysis, monthly streamflow data in the Nak Dong River, the Han River, and the Keum River were used and the data were changed to modular coefficient in order to make the analysis convenient. At first, the fitness of monthly streamflow to 2-Parameter Gamma distribution was tested by Chi-square and Kolmogrov-Smironov test, by which it was found the monthly streamflow were fit well to this Gamma distribution function. Then, the Gamma Model based on the Gamma distribution and Monte Carlo Method was used in the simulation of monthly streamflow, and simulateddata showed that all their stastical characteristics were preserved well in the simulation. Consequently, it can be concluded that the Gamma Model is suitable for the simulation of monthly streamflow series directly by using the Mote Carlo technique.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1036-1041
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• 2008

Double facade systems are often paid attention of as an effective energy saving measure for curtain wall buildings. However, it is not easy to install the system in existing buildings and requires substantial investment. An innovative double window system is proposed in this study which can be installed with exiting window systems in a cost effective way. the proposed system is connected to existing return ducts to make airflow between the existing window and the newly installed window. To ensure the best performance of the proposed system, simulation-based analysis was implemented in which airflow characteristics of inside double window were examined according to air pressures of return duct and window material by using computer simulation ESP-r. the overview of the proposed system and the results of the simulation-based analysis are presented in this paper.

• Journal of Korean Institute of Industrial Engineers
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• v.42 no.2
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• pp.151-164
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• 2016

In this paper, we deal with a risk analysis for an IPS (Integrated power system) and propose a simulation model combining the fault tree and event tree in order to estimate the system availability and risk level, together. Firstly, the basic information such as operational scenarios, physical structure, safety systems is explained in order to make the fault tree and event tree of the IPS. Next, we propose a discrete-event simulation model using a next-event time advance technique to advance the simulation time. Also the state transition and activity diagrams are explained to represent the relationship between the objects. By numerical examples, the redundancy allocation is considered in order to decrease the risk level of the IPS.

• 한국디지털정책학회:학술대회논문집
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• 2006.06a
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• pp.87-109
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• 2006

The purpose of this paper is to examine the present performance evaluation methods and to make Monte Carlo Simulation Model for the IT-based Government innovation project. It is suggested the proper ways in applying of Monte Carlo Simulation Model by integration of present evaluation methods. It develops the theoretical framework for this paper, examining the existing literature on proposing an approach to the key concepts of the economic impact analysis methods. It examines the actual conditions of performance evaluation focusing on the It-based Government Innovation project. It considers how the simulation model is applied to the performance management in the public innovation project focusing on the framework, process and procedure of performance management.

• Proceedings of the Korea Society for Simulation Conference
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• 1997.04a
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• pp.124-127
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• 1997

A key element in the control of Automated Guided Vehicle Systems (AGVS) is dispatching policy. This paper proposes a new dispatching algorithm for an efficient operation of AGVS. Based on an evolutionary operation, it has an adaptive control capability responding to changes of the system environment. The performance of the algorithm is compared with some well-known dispatching rules in terms of the system throughput through simulation. Sensitivity analysis is carried out varying the buffer capacity and the number of AGVS.

• Smart Structures and Systems
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• v.20 no.4
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• pp.473-481
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• 2017

This study suggests a simple, convenient and non-destructive method for investigation of the Young's modulus detection in stepped shafts which only utilizes the first-order resonant frequency in flexural mode and dimensions of structures. The method is based on the impulse excitation technique (IET) to pick up the fundamental resonant frequencies. The standard Young's modulus detection formulas for rectangular and circular cross-sections are well investigated in literatures. However, the Young's modulus of stepped shafts can not be directly detected using the formula for a beam with rectangular or circular cross-section. A response surface method (RSM) is introduced to design numerical simulation experiments to build up experimental formula to detect Young's modulus of stepped shafts. The numerical simulation performed by finite element method (FEM) to obtain enough simulation data for RSM analysis. After analysis and calculation, the relationship of flexural resonant frequencies, dimensions of stepped shafts and Young's modulus is obtained. Numerical simulations and experimental investigations show that the IET method can be used to investigate Young's modulus in stepped shafts, and the FEM simulation and RSM based IET formula proposed in this paper is applicable to calculate the Young's modulus in stepped shaft. The method can be further developed to detect mechanical parameters of more complicated structures using the combination of FEM simulation and RSM.

• Journal of Electrical Engineering and Technology
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• v.10 no.5
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• pp.2083-2088
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• 2015

The transient characteristics of the tri-axial High Temperature Superconducting (HTS) power cable are different from those of a conventional power cable depending on whether the cable is under a steady or transient state due to the quench. Verification using simulation tools is required to confirm both the characteristics of the cable and the effect of the cable when it is applied to a real utility. However, a component for the cable has not been provided in simulation tools; thus the RTDS-based model component of the tri-axial HTS power cable was developed, and a simulation was performed under the transient state. The considered properties of model component include resistance, reactance and temperature. Simulation results indicate the variation of HTS power cable condition. The results are used for the transient characteristic analysis and stability verification of the tri-axial HTS power cable. In the future, the RTDS-based model component of the cable will be used to implement the hardware-in-the-loop simulation with a protection device.

• Korean Journal of Construction Engineering and Management
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• v.6 no.1 s.23
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• pp.73-79
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• 2005

This paper, introduces a Stochastic Project Scheduling Simulation system (SPSS III) developed by the author to predict a project completion probability in a certain time. The system integrates deterministic CPM, probabilistic PERT, and stochastic Discrete Event Simulation (DES) scheduling methods into one system. It implements automated statistical analysis methods for computing the minimum number of simulation runs, the significance of the difference between independent simulations, and the confidence interval for the mean project duration as well as sensitivity analysis method in What-if analyzer component. The SPSS 111 gives the several benefits to researchers in that it (1) complements PERT and Monte Carlo simulation by using stochastic activity durations via a web based JAVA simulation over the Internet, (2) provides a way to model a project network having different probability distribution functions, (3) implements statistical analyses method which enable to produce a reliable prediction of the probability of completing a project in a specified time, and (4) allows researchers to compare the outcome of CPM, PERT and DES under different variability or skewness in the activity duration data.

• Journal of Korean Society of Rural Planning
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• v.11 no.2 s.27
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• pp.1-8
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• 2005

This study is to develop a web-based integrated system for flow of agricultural products based on recent researches with engineering approach. The system stands on the basis of web for accessibility and usability. Three parts of the system consist of analysis of regional shipping characteristics using tank model, estimation of pallet load efficiency with Monte Carlo Simulation, a long term prediction of market price with reliability analysis. Besides a decision support module for selecting optimal shipping market is added through synthesizing techniques and spatial analysis using GIS and applied to Chinese cabbage of Pyeongchang in 2004.