• Korean System Dynamics Review
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• v.12 no.4
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• pp.157-175
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• 2011

The purpose of this paper is to find out the effects of the gambler's fallacy bias on the supply chain. For this study, the simulation was based on a casual structure of the Beer Distribution Game from Sterman(2000)'s Business Dynamics and designed into 2 different models : the first model carries the exact same structure as the reference mentioned above and for the second model, the comparison model is used reflecting gambler's fallacy bias. Each model has 2 different demand patterns. The 4 cases of models was tested with 1,000 different random number seeds. The results for the simulation are following : In the aspect of the inventory and out of stock, the basic model resulted better than the comparison. However, in the bullwhip effect, the comparison model has less than the basic in terms of the level demand pattern. But there was no significant difference in the cycle demand.

• Convergence Security Journal
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• v.23 no.2
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• pp.3-10
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• 2023

In the malware distribution network existing on the web, there is a central node that plays a key role in distributing malware. If you find and block this node, you can effectively block the propagation of malware. In this study, a centrality search method applied with risk analysis in a complex network is proposed, and a method for finding a core node in a malware distribution network is introduced through this approach. In addition, there is a big difference between a benign network and a malicious network in terms of in-degree and out-degree, and also in terms of network layout. Through these characteristics, we can discriminate between malicious and benign networks.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.389-391
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• 2009

The performance loss as pressurized by inside components like GDL and bipolar plate happened when assembling the PEMFC stack with clamping force. Numerical analysis of Gasket was carried out to analyze distribution of clamping pressure about the inside components. In case of the gasket, Mooney-Rivlin model which is the Strain Energy Function was used for numerical analysis. This result made the stress distribution of bipolar plate to expect.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.780-782
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• 2001

The mold transformer has anti-burnt and possibility of small size contrary to oil-immersed transformer. The mold transformer has generally cooling duct between low voltage coil and high voltage coil and also made by one body molding for small size and low loss. In this paper, the temperature distribution of designed 50kVA pole mold transformer for power distribution is investigated by FEM program. The designed transformer is also manufactured and temperature rise test is carried out.

• Journal of ILASS-Korea
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• v.3 no.2
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• pp.1-13
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• 1998

A theoretical and experimental study was carried out to predict the drop size distribution of the pressure swirl atomizer. Various analytical methods using the Kelvin-Helmholtz instability theory were tried to examine the wave growth on cylindrical liquid sheets. Cylinderical liquid sheets were extended to the case with the conical sheets. Perturbations due to tangential motion as well as longitudinal one were taken into account. And it was assumed that the breakup occurs when amplitude ratio exceeds exp(12), drop sizes were predicted only by theoretical approach. Drop size distribution was obtained by using maximum entropy formalism. Seven constraints in the form of the definition of mean diameter were used in this formulation in order to avoid the difficulties of estimating source terms. In this study $D_{10}$ only was introduced into the formulation as a constraint. The predicted drop size and drop size distribution agreed well with the measured data.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2001.11a
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• pp.151-158
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• 2001

This paper presents a method for evaluating the lubrication characteristics between the plunger and cylinder in a radial type plunger pump. A numerical analysis is carried out in order to obtain the pressure distribution and acting forces between the plunger and cylinder. The pressure distribution is also measured experimentally by using pressure transducer through the cam type test machine. The experimental pressure distribution result is compared with the numerical result which is estimated by the computer simulation. In conclusion, the acting forces to the plunger are expressed for the operating conditions such as clearance, supply pressure, rotation speed and viscosity of oil.

• Wind and Structures
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• v.7 no.6
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• pp.359-372
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• 2004

Wind tunnel model studies were carried out to determine the wind load distribution on tributary areas near the gable-end of large, low-rise buildings with high pitch planar and curved roof shapes. Background pressure fluctuations on each tributary area are described by a series of uncorrelated modes given by the eigenvectors of the force covariance matrix. Analysis of eigenvalues shows that the dominant first mode contributes around 40% to the fluctuating pressures, and the eigenvector mode-shape generally follows the mean pressure distribution. The first mode contributes significantly to the fluctuating load effect, when its influence line is similar to the mode-shape. For such cases, the effective static pressure distribution closely follows the mean pressure distribution on the tributary area, and the quasi-static method would provide a good estimate of peak load effects.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.9
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• pp.513-520
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• 2003

Service restoration is an emergency control in distribution constrol centers to restore out-of-service area as soon as possible when a fault occurs in distribution networks. therefore, it requires fast computation time and high quality solutions for load balancing. In this paper. a load balance index and heuristic guided best-first search are proposed for these problem. The proposed algorithm consists of two parts. One is to set up a decision tree to represent the various switching operations available. Another is to identify the most effective the set of switches using proposed search technique and a load balance index. Test results on the KEPCO's 108 bus distribution system show that the performance is efficient and robust.

• Proceedings of the KIEE Conference
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• summer
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• pp.381-383
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• 2004

This paper presents for service restoration Abstract -in electric power distribution systems. The aim of the service restoration is an emergency control in distribution system to restore out-of service areas as soon as possible when a fault occurs in distribution system. For this reason, this paper presents a new service restoration strategy for multi-outage areas. Proposed algorithm consists of two methods. One is individual restoration scheme, the other one is integrated restoration scheme. The former determines restoration order of outage areas based on restoration index. If the former method can not generate a feasible restoration plan, the latter would try to find new configuration without overloaded section through tie exchange method.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.556-557
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• 2005

The distribution facilities, such as suspension insulator, line post insulator, lightning arrester, COS, used for long periods in the industrial pollution area were investigated. The electrical test and the material analyses were performed on the polluted and non-polluted facilities. The low frequency dry flashover voltage of polluted suspension was decreased about 8% in comparison with non-polluted one. The polluted materials turned out with the iron which came from the foundries. The polluted materials turned out with the iron which came from the foundries. This conductive materials decreased the leakage distance, resulting in reducing of electrical properties.