• Proceedings of the Acoustical Society of Korea Conference
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• 1994.06a
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• pp.764-769
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• 1994

The impedance of an electro-acoustic transducer can be controlled by motional feedback, and the noise in a duct can be reduced actively by adjusting the impedance using an additional sound. In this paper, two approaches for active noise control using motional feedback (MFB) loudspeaker are described. First configuration uses an external sensor to pickup of source directly. In this configuration, the adaptation of controller is necessary to compensate the change of transfer function from noise source to control poing. The second configuration uses a new adaptive algorithm specialized for peridic noise. Because this configuration does not require any reference input and the error sensor couples very tightly with control loudspeaker, this MFB system itself is independent of the duct condition. No microphone are required in both configurations, so that a more reliable and stable active control system can be realized under severe conditions such as high pressure, high temperature, dust, flow and so on.

• The Transactions of the Korea Information Processing Society
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• v.4 no.11
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• pp.2745-2755
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• 1997

Many large-scale enterprises have developed software systems to build management information system for their business. However, it is hard to maintain share ability of data, compatibility of operation methedology, and interoperability among subsystems when the development project progresses since each distributed team prepares a development plan for its subsystem and must have poor communication problem among those teams. We must apply software configuration management to the whole life cycle of the software system in order to solve those Problems. We need a model and a repository in order to execute configuration management on configuration products like document, data, and source code which are generated through the life cycle of software development. In this paper, we suggest a model for configuration change control where cross- referencing among life cycle Phases and data-sharing are highlighted, and define ER model to use IRDS(Information Resource Dictionary system) and IRD schemas.

• Journal of the Korean Society of Industry Convergence
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• v.14 no.2
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• pp.59-65
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• 2011

$CO_2$ Welding which uses $CO_2$ instead of inert gas is most widely used in industrial sites. Welding rod for $CO_2$ Welding is roughly divided into solid wire and flux cored wire. $CO_2$ Welding has higher efficiency than any other welding methods, and also economic and speedy to handle, that's why is used frequently for welding general structures. As most of studies about $CO_2$ Welding are focused on metallurgical changes of successful joints, they developed theories about the change of configuration on weld parts. This study is especially focused on not only the change of configuration on weld parts, but also the change of the penetrating depth through changing the position of welding torch. For inspection, applied AWS A5.20 E70-1 among welding wires and fixed moving angles of torch, but controled the values of voltage and the position of welding. Also Automatic Feed Mechanism is used for exact movement of material, specimen is a piece of steel for general structures. By measuring and analyzing the configuration of sliced section and the values of welding leg length and welding throat after welding, the outcome about the changes turned out.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.1D
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• pp.17-24
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• 2011

In recent, the enhancement of guide signs system for expressway were studied. And newly suggested signs in that research show left-right bilingual (Korean/English) configuration of 2 destinations whereas existing signs showed top-bottom configuration. However the new configuration have not been evaluated with discreet examination. In this study, several bilingual configuration designs are developed and evaluated with human factors experiment. Therefore the design with the shortest legibility time were chosen as a best design. As a result, the fact that the change of Korean/English configuration shows different results of the legibility time was confirmed. The guide sign with left-right bilingual (Korean/English) configuration of 2 destinations showed less legibility time than that of the existing signs with top-bottom configuration.

• Journal of Korea Game Society
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• v.5 no.1
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• pp.33-40
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• 2005

Game Designs & Developers that system designs improve, the product and the change of tasks to all developers are essential in achieving On-Line Game project. Existent Or-line Game project management designs supper the definition and the change of project activities, and configuration management designs support version check, workspace management, build management, etc. In this paper. the proposed Design defines Game component based development process model, and achieves recording of process progression, processing the request of change, reporting the progression of each task, product registering and change, version recording, artifact or form search, etc. using UML. Furthermore, study on the stake holders get the systematic management and standardization by sharing information that are necessary in Game design & development and configuration management in distributed environment using the system integrated management design.

• Journal of Korea Game Society
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• v.4 no.3
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• pp.21-28
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• 2004

Game Designs & Developers that system designs improve, the product and the change of tasks to all developers are essential in achieving On-Line Game project. Existent On-line Game project management designs supper the definition and the change of project activities, and configuration management designs support version check, workspace management, build management, etc. In this paper, the proposed Design defines Game component based development process model, and achieves recording of process progression, processing the request of change, reporting the progression of each task, product registering and change, version recording, artifact or form search, etc. using UML. Furthermore, study on the stake holders get the systematic management and standardization by sharing information that are necessary in Game design & development and configuration management in distributed environment using the system integrated management design.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.327-328
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• 2006

In generally, under the influence of over-pressure drop, serious problems such as cavitation, choked flow, flashing and vibration has been coming around the tilting disk check valve. A PIV experiment to examine the cause of energy loss has been performed and the improvement configuration of valve seat based on this visualization results is proposed. In the visualization results, flows in the piping system became instability under the influence of the shape of boss. This unstable flows induces sudden pressure drop in the piping system. So, we change the configuration of boss as a streamlined design to be stabilized the flows. A pressure measurement has been performed to know that the influence of the configuration change. In result, the rate of pressure loss reduction is about 22% at the position of No. 2 and 24.2% at the position of No. 6 in comparison with pre-improved shape.

• The Korean Journal of Applied Statistics
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• v.17 no.1
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• pp.13-26
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• 2004

According to economic growth theory, location configuration of business enterprises engaged in specific industries has spatial affinity. In this research we defined industrial concentration index to measure industry agglomeration using the characteristics of dispersion parameter of negative binomial distribution, and used the industrial concentration index to examine aspect of spatial configuration change. We utilized Census on Basic Characteristics of Establishments of 1995 and 2000 to deduce industrral concentration indices of 7 knowledge-based industries and 9 strategy-based industries of Choongbuk Province and analyzed the aspect of spatial configuration change.

• KIEAE Journal
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• v.12 no.1
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• pp.21-27
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• 2012

This study aims at finding the trend changes of spatial configuration in housing units of Korean apartments in the 2000s. Among the housing units in the apartments built by large construction companies, we have selected ones with small and regular sizes, $59m^2$ and $84m^2$ respectively, and investigated the number of bays, the location of wet zone and the spatial flexibility in the housing units selected for analysis. In conclusion, the number of bays in the housing unit has gradually increased, after allowing for the structural change of the balcony in the legal. It is estimated that the trend has came from the intent to increase the numbers of the externally exposed surfaces of the balcony, ensure a good view, lighting, ventilation and spatial flexibility. The location of wet zone, water-needed space such as a bathroom or a kitchen, has changed in the direction to facilitate the expansion and modification of space. Variable range of space has gradually expanded by using the balcony and wet zone as much as possible. In order to configure more effectively spaces in housing environments, the future study should be implemented to develop tools for realizing sustainable housing environment at the levels of not only the housing unit. but also the entire building, housing site, and city.

• The KSFM Journal of Fluid Machinery
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• v.9 no.1 s.34
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• pp.40-46
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• 2006

Efficiency of a centrifugal pump is known to drop rapidly with a decrease of specific speed $n_s$. However, below $n_s=60\;[min^{-1},\;m^3/min,\;m]$, the pump characteristics are not yet clear. Therefore, present study is aimed to investigate the influence of large change of specific speed on the performance of a very low specific speed centrifugal pump. Moreover, influence of impeller configuration on the performance of very low specific speed pump is investigated. The results show that very low specific speed can be accomplished by reducing volute throat sectional area using circular spacer. Influence of the spacer's location and configuration in the discharge passage on the pump performance is very small. Best efficiency of very low specific speed centrifugal pump decreases proportionally to the specific speed but the best efficiency decreases on a large scale in the range of $n_s<40$. Influence of impeller configuration on the pump performance and radial thrust of centrifugal pump are considerably small in the range of extremely low specific speed $(n_s=25)$.