• Particle and aerosol research
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• v.10 no.4
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• pp.155-162
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• 2014

The internal temperature will change depending on operation conditions and material of cyclone dust collector. This study compares the results of collection efficiency and temperature distribution on the different heat flux at wall of dust collector. The previous researcher's experiment results were used to confirm the reliability of CFD(Computational Fluid Dynamics) model. Based on this verified CFD model, we extended the analysis on the cyclone dust collectors. In CFD study, we used RNG k-epsilon model for analysis of turbulence flow, fluid is air, the velocity at inlet is 10 m/s, the temperature of air is $600^{\circ}C$. Because of the difference of outer vortex and inner vortex temperature, the collection efficiency will reduce with the increase of heat flux, showed the highest collection efficiency at heat insulation.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.38 no.2
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• pp.93-99
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• 1989

This paper describes Sinusoidal Wave-Variable Voltage Variable Fequency (SW-VVVF) system for the high efficiency drive of a 3-phase induction motor. SW-VVVF system consists of a 3-phase 24-pulse converter and a SPWM inverter. The converter with additional 2 tap diode circuits in interphase reactor reduces harmonics in input current. The SPWM inverter consists of an improved PLL system and a V/F controller, which reduces harmonics in output current and performs a high efficiency algorithm by maintaining a constant slip frequency and compensating for the velocity variation of the induction motor with the change of load. Therefore, this system reduces harmonics in input and output currents, and also can drive an induction motor with high efficiency in an economical way. We have proved its utility through experiment.

• Journal of the Korea Society of Computer and Information
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• v.23 no.11
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• pp.9-15
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• 2018

The Ministry of National Defense announced 'Defense Reform 2.0' that aims to strengthen the country's security for decrease of regional uncertainties, growing requirements for advanced technologies, and a need for more efficiency in the Republic of Korea(RoK) Armed Forces this year. It said RoK Armed Forces have to change efficiently in preparation for rapid decline in military service resources as demographic cliff turning into reality, and the rapid evolution of the "battlefield environment" caused by developments in military science and technologies. RoK Navy combat Management System(CMS) made by domestic proprietary technology since 2000s and development centered on Agency for Defense Development require design changes for added requirements. So in this paper, I propose method of design a low cost and high efficiency navy CMS architecture based on high performance server and virtualization technology. And I create a test environment for analysis performance and compare the performance of proposed navy CMS and existing navy CMS.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.829-834
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• 2002

Carbonation of concrete used impregnation alkalization agent construction reinforcement, recovery of pH, elevation improve, in which efficiency decline mternal force of number and durability because of impregnation alkalization agent applyment general standard, used concrete. Material quality not understanding lack of study and stadard. This study investigate change of PH. recovery depth of impregnation alkalization agent, recovery depth belong a mount of aggregate that comparision, analysis parity.

• Journal of the Korean housing association
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• v.16 no.2
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• pp.45-53
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• 2005

Korea has recently experienced a large change in civil architecture and urban environment. However most of civil architectures and urbanization have been accomplished without considering economic efficiency and impact. This study focuses primarily on an analysis on the relationship between architecture and economic efficiency through the foreign and domestic case studies. Secondly, it is going to elucidate the economic properties on Korean architecture recently established. With perspectives of the analysis, we need to consider the following factors in the production of architecture; labor intensive industry, seasonal industry, strong and domestic demand.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.12
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• pp.3315-3325
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• 1994

To study the variation of charging efficiency in the engine intake, the method to change the natural frequency of intake system using the intake control valve was studied and it has been used in actual engine to increase the intake air. In this paper, the method of characteristics was used to analyze the non-steady state and compared with the experimental data of the 6-cylinder diesel engine showing the effectiveness of the method theoretically.

• Journal of environmental and Sanitary engineering
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• v.14 no.4
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• pp.69-76
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• 1999

This research was carried but to investigate the characteristics of mist removal with the change of operating conditions in the plasma reactor of impulse streamer corona based on the distribution of particle size measured by laser diffraction spectrometers. The operating conditions in this experiment were power of impulse streamer corona, gas velocity, collection time, and SOx/NOx concentration. The collection efficiency T(d) was estimated by distribution of particle size in the collection zone through the advanced model.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.354-355
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• 2005

Indium tin oxide (ITO) thin film was polished by chemical mechanical polishing (CMP) by the change of process parameters for the improvement of electrical and optical properties of ITO thin film. Light transparent efficiency of ITO thin film was improved after CMP process at the optimized process parameters compared to that before CMP process.

• Journal of the Korea Society of Computer and Information
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• v.5 no.3
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• pp.215-219
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• 2000

The purpose of this paper is to propose a method to maximize the efficiency of a content-based image retrieval for various kinds of images. This paper discuss the self-adaptivity for the change of image domain and the self-selection of optimal features for query image, and present the efficient method to maximize content-based retrieval for various kinds of images. In this method, a content-based retrieval system is adopted to select automatically distinctive feature patterns which have a maximum efficiency of image retrieval in various kinds of images. Experimental results show that the Proposed method is improved 3% than the method using individual features.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.325-326
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• 2021

Design changes are inevitable areas of work for construction engineers as they occur frequently in the construction site, and are becoming a technical measure of the technical person to the design change. In this study, the purpose is to analyze by comparing the availability of excel and the enscised program during design changes through the case, and to present the efficiency of the the Cost-of-construction Program.