• The Journal of Industrial Distribution & Business
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• v.6 no.1
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• pp.37-40
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• 2015

Purpose - Investors, creditors, governments, and others make decisions using reasonable information provided by others. In many cases, the users of this information have goals and objectives conflicting with those of the information's producers, indicating the need for external auditors. Research design, data, and methodology - Competition in auditing has noticeably intensified globally, especially in developed countries. This means that auditors are striving to increase the efficiency of their methods. In recent years, risk-based auditing has become prominent among these efforts. In risk-assessment auditing, the auditor may directly affect the effectiveness and efficiency of the audit. Results - As a central framework, the risk assessment process improves audit quality and effectiveness such that the audit will lead to necessary changes. Previous studies have shown that risk assessment affects the nature, timing, and content of audit procedures. Conclusions - In the planning stage of an audit, audit risk assessment may identify any inappropriate or inefficient distribution of resources or determine whether the results of an audit will be ineffective or incorrect. Thus, assessing audit risk is a critical task.

• Journal of the Korea Society for Simulation
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• v.13 no.4
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• pp.17-29
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• 2004

The focus of this study is to represent a methodology of analysis for integrated logistic system by means of the Evolution Strategies and Data Envelopment Analysis(DEA). The integrated logistic system is composed of AS/RS (Automated Storages and Retrieval System), AGVs(Automated Guided Vehicle System) and Conveyor System. We design the simulation alternatives with choosing the qualitative critical factors for the each subsystem. Evolution Strategies is used to optimize the quantitative critical factors and responses of each alternative. DEA is applied to measure the efficiency of the alternatives in order to select the optimal operation efficiency scheme. The method of analysis which combines Evolution Strategies with DEA can be used to analyze the qualitative and quantitative critical factors in the integrated logistic systems.

• The KSFM Journal of Fluid Machinery
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• v.20 no.2
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• pp.26-31
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• 2017

In the present study, 20 kW turbine for OTEC with a ejector and a motive pump is designed and performance prediction is implemented by means of CFD. The meridional analysis for initial geometry and CFD for detail design are used to design the turbine. This turbine has about 90.9% efficiency and 28.47 kW power at 15,000 rpm and pressure ratio of 1.53. Homogeneous mixture model is used because two phase flow can be occurred in the turbine. Performance evaluation is carried out and then results are presented by plotting of power, mass flow rate and efficiency as varying pressure ratio and rotational speed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.12
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• pp.55-64
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• 2014

This paper presents a case study to investigate the monthly calculation method of ISO 13790 applied for a office building. The energy performance analysis according to improvement of insulation and air permeability of windows in K office buildings is investigated by means of building energy efficiency rating tool ($ECO_2-OD$). The K building energy system is tested experimently by the measurement of PMV(predicted mean vote) for the control of indoor thermal environment and heat transmission coefficient of windows and interior walls respectively, before and after the example K office building is remodeled passively. Therefore, Internet based energy assessment program of energy efficiency rating of office building can be applied as a program for the annual energy requirement and for evaluation of energy savings from the experimental and simulation results.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.36-38
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• 2005

In home appliances, electric energy is optimally controlled by using power electronics technology, creating a comfortable environment in terms of energy saving, low sound generation, and reduced time consumption. Usually simplicity and robustness make the three phase induction motor attractive for use in domestic appliance, including washing machines. Two main types of domestic washing machine have evolved. We focus on the front loading machine favored in Europe, which has a horizontal drum axis. The efficiency improvement in home appliances is very important for customers. Induction motor efficiency can be improved by means of loss reduction, which can be realized by motor selection and design, improvement of the waveforms supplied by power Inverter, utilizing a suitable control method. So this paper describes the architecture and feature of washing machine fed induction motor drive under minimizing losses vector control.

• Korean Journal of Computational Design and Engineering
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• v.11 no.6
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• pp.422-428
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• 2006

In this paper, an NC data optimization approach for enhancing 5-axis machining speed is presented. It is usual to use expensive commercial CAD/CAM programs for NC data of 5-axis machining, since it needs very large calculations for optimal tool positioning and orientation, tool path planning, and collision-free tool path generation. Since commercial CAD/CAM systems have similar functions and efficiency based on common algorithms of reliable theories, they do not have their own unique features for machining speed and efficiency. In other words, most commercial CAD/CAM systems consider only the characteristics of part geometry to be machined, which means that they generate almost the same NC data if the part to be machined is the same, even though different machines are used for the pin. A new approach is proposed for optimizing NC data of 5-axis machining, which is based on the characteristics of the machine to be operated. As a result, the speed of 5-axis machining can increase without losing machining accuracy and surface quality.

• Journal of the Korean Home Economics Association
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• v.29 no.1
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• pp.97-110
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• 1991

The purpose of this study is to suggest more efficient modular units of the storage furniture system based on the two previous studies of the apartments storage furniture. This study is also to show the ways and means of making practical use of the results which come from the previous studies. The specific purpose of this study is, 1. To establish the modular furniture system minimizing the dead space, using investigation results of the bedroom size of existing apartments. 2. To establish the modular furniture system maximizing the storage space with utmost efficiency, based on the results of the actual storage condition from the previous research. 3. To suggest a case study of the different modular furniture system suiting 6 different bedroom sizes with the utmost efficiency, based on the results of above two purpose. On the bases of these research results, the design of various units of modular system furniture for bedrooms were suggested.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.5
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• pp.446-452
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• 2005

As the name means, the WiBro is mobile service so that radio internet connection may be possible with high transmission speed using various terminal. Because WiBro is choosing suitable All-lP network architecture in internet service offer, structure of network is simple and the various supplementary service offer is available. This paper presented mobility model of terminal and proposed efficient way to improve existent way that transfer efficiency drops by data padding and analyze the performance by simulation.

• Journal of Power Electronics
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• v.13 no.3
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• pp.458-468
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• 2013

Large capacity reactive power compensation and harmonic control in the low-voltage grid of an enterprise, are important technical means to improve power quality and reduce power loss. In this paper, the principle of an efficient power quality controller is analyzed. Then, key application technologies of the HPQC which would influence the performances of the HPQC are studied. Based on an analysis of the harmonic shunt problem, a frequency dividing control strategy of the HPQC continuous subsystem is proposed. A parameter design method of the HPQC discrete subsystem and its installation method are also proposed to ensure the system compensation effect. HPQC systems have been designed for a copper foil plant. The effectiveness of this paper has been verified by the simulation and application results.

• Communications for Statistical Applications and Methods
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• v.25 no.1
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• pp.1-13
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• 2018

In many studies, a researcher attempts to describe a population where units are measured for multiple outcomes, or responses. In this paper, we present an efficient procedure based on ranked set sampling to estimate and perform hypothesis testing on a multivariate mean. The method is based on ranking on an auxiliary covariate, which is assumed to be correlated with the multivariate response, in order to improve the efficiency of the estimation. We showed that the proposed estimators developed under this sampling scheme are unbiased, have smaller variance in the multivariate sense, and are asymptotically Gaussian. We also demonstrated that the efficiency of multivariate regression estimator can be improved by using Ranked set sampling. A bootstrap routine is developed in the statistical software R to perform inference when the sample size is small. We use a simulation study to investigate the performance of the method under known conditions and apply the method to the biomarker data collected in China Health and Nutrition Survey (CHNS 2009) data.