• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.148-152
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• 2007

In recent days, on account of the cultural development and the improvement of citizen's consciousness level, it is the real situation that the construction of small-scaled Multi-Purpose Hall where various cultural events could be performed, is on increasing. However, since the most of Multi-Purpose Hall had been designed and built up without any consideration on Acoustic Factor, many problems are on occurring thereat. Since those small-scaled Multi-Purpose Hall have been mostly used with the finishing material which contains a high degree of Acoustic Absorption indiscreetly, both diffusion and reflection of sound are not establishing properly, and because thereverberation of sound is very low, in case of musical performance by musical instrument, its sound hears too arid and stiff, there occurs some acoustic defect such as it becomes difficult for music appreciation with sufficient timbre, so that the capability improvement on the matter is urgently requiring situation. Therefore, this Study has tried to seize the satisfaction level about the small-scaled Multi-Purpose Hall after betterment of the acoustic performance by appraise the acoustic condition of the Hall, using Auralization Technique that can experience Virtual Acoustic Field regarding to the small-scaled Multi-Purpose Hall as its object. It is deemed that such research result could be practically used as the useful material which enables to bring a reduction effect of construction cost as well asenhancement of the acoustic performance through its presupposition?control on the acoustic problem when construction or renovation of other similar small-scaled Multi-Purpose Hall in the future.

• Journal of Korean Society of Steel Construction
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• v.24 no.4
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• pp.461-468
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• 2012

P.E.B (Pre-Engineering Building) system means an economical system, which designs and uses optimal section proportion of tapered members according to the magnitude of bending moment. However, it is hard to adjust the friction type bolted joint in the joint of tapered member in the P.E.B system. End-plate connection is mainly used in this system due to that difficulty. Because P.E.B system has end-plate vertical defacts by heat welding deformation, a gap between end-plates and rafter or rib can be observed. In this study, an examination of construction stability was throughly performed and analyzed by the investigation of permissible internal force of bolts in end-plate connections under the bending moment using the end-plate's initial connection-defect (gap).

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.46-53
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• 2002

Although Public Construction Works in Korea have been executed according to Government Contract Act, and nature of contract is very complicated. So it is difficult to define liability for the defects. Therefore the studies on the defective performance and contractor's defects liability were remained one of the non-cultivated virgin land. As a result, contract privy waive the right to claim or generally resolve the problems. Therefore domestic and overseas liability for the defects was investigated and liability for the defects, under and after construction, on the defective performance and defects, was analysed. With a literature research, contractor's defect liability was systematically analyzed, problems were defined and resolution of the problem were suggested item by item in this study.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.531-534
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• 2002

Complexity in construction projects has increased over the years, which has led to an increase in the number of organizations involved in those projects. In today's environment, these organizations operate in different parts of the world requiring their personnel to be geographically distributed. So, these organizations construct and utilize the information systems. However, looking into this systems' content, those use two-dimensional planes such as pictures and drawings to check the scheduling etc., which cause the defect of communication and problems such as change order. Accordingly, this study introduces the Web 3Ds and 3D Libraries, intends to present the effect on modeling of three-dimensional work structure using Web 3D in cyberspace.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.559-564
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• 2003

Recently, quality inspection and A/S management have been considered as one of the major issues for satisfying customers, increasing competitiveness and raising image of a company in domestic construction industry. However, the qualify inspection and A/S management have not performed systematically because of insufficient field managers, the excessive amount of documents and complicated work process. The primary objective of this study is to propose a quality inspection and A/S management system using information technology which enables field managers to efficiently gather the information of defection and A/S in apartment house. It is anticipated that the effective use of the proposed system would be able to improve communication among the related participants and systematically accumulate data that might be used in similar construction projects.

• Fire Science and Engineering
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• v.19 no.2 s.58
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• pp.93-104
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• 2005

Nowadays, the arson is not common interest happening. the arson has been handled with a crime of violence along with murder, robbery and rape. because of being detrimental to the public clam. but the arson a has not been made award of a serious social problem. There is a rise in the control possibility according to a level of national concern. we have known that the last fire accident of the Deagu underground It took a heavy toll of lives and the property due to our no interest in arson. The government and regional self governing community have fully aware of the serious of the arson so that we can make arrangement for overall measures. The government should not only make up for legislation and systematize to correct a defect but also there is uniting the countermeasure system of the organs. The government establish particular research institution of the arson to consider a useful countermeasure. The investigation authorities should develop the investigation technique to arrest an arsonist. The relevant post strengthen the public relation to bring up a private organization of fire prevention in order to prevent the arson to try the government best.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.3
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• pp.713-719
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• 2000

In order to Prepare the$Ge_xSi_{1-x}/Si$(111) heterosructure by solid phase epitaxy (SPE), about 1000A of Au and about 1000A Ge were sequentially deposited on the Si(111) substrate. The resulting Ge/Au/Si(111) samples were isochronically annealed in the high vacuum condition. The behaviors of Au and Ge during thermal annealing and the structural Properties of $Ge_xSi_{1-x}$ films were characterized by Auger electron spectroscopy (AES), X-ray diffraction (XRD) and high resolution transmission electron microscopy (TEM). The a-Ge/Au/Si(111) structure was converted to the Au/GeSi/Si(111) structure. Defects such as stacking faults, point defects and dislocations were found at the GeXSil-X(111) interface, but the film was grown epitaxially with the matching face relationship of $Ge_xSi_{1-x}/$(111)/Si(111). Twin crystals were also found in the $Ge_xSi_{1-x}/$(111) matrix.

• The KIPS Transactions:PartD
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• v.8D no.4
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• pp.427-438
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• 2001

Recently, Environmental Control Devices of Green House for Protected Cultivation is composed of on/off-type Controller to control each device using timer in equipment of intensive Labor. In case of system, it is difficult to grasp condition of the greenhouse about errors when this system has defect of a hardware, and it operates in the remote place or at night. In this paper, we developed a system that capable of replacing the existing control method of on/off with display panel in the greenhouse, monitoring data aquisition and status in the greenhouse using client computer based on internet. Also this system can communicate with each local greenhouse, and send alarm message about error. And we constructed web server to manage efficient informations for environmental control and corps cultivation in the greenhouse.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.1
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• pp.75-81
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• 2011

Dissimilar joining of aluminum 6061-T6 alloy to aluminum 5083-O alloy was performed using friction-stir welding technique. The mechanical properties, hardness, macro- and micro-structure on dissimilar friction-stir-weld aluminium alloy were investigated. Mechanical properties of the weld mainly depend on which Al alloy is placed at the retreating sides of the rotating tool respectively during dissimilar friction-stir weld because the microstructure of stir zone was mainly composed of welded Al alloys of the retreating side. Onion ring pattern was observed like lamella structure stacked by each Al alloy in turn. It apparently results in defect-free weld zone that traverse speed was changed to 124 mm/min under conditions of tool rotation speed like 1250 rpm with 5 mm of tool's prove diameter, 4.5 mm of prove length, 20 mm of shoulder diameter, and $2^{\circ}$ of tilting angle. The 231 MPa of ultimate stress and the 121 MPa of yield point are obtained about the friction-stir-welded Al 6061-T6(AS) to Al 5083-O(RS).

• Tribology and Lubricants
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• v.34 no.4
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• pp.146-159
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• 2018

This paper presents a wear analysis procedure for calculating the wear of journal bearings of a four-strokes and four-cylinder engine operating at a constant angular crank shaft speed during firing conditions. To decide whether the lubrication state of a journal bearing is in the possible region of wear scar, we utilize the concept of the centerline average surface roughness to define the most oil film thickness scarring wear (MOFTSW) on two rough surfaces. The wear volume is calculated from the wear depth and wear angle, determined by the magnitude of each film thickness on a set of oil films with thicknesses lower than the MOFTSW at every crank angle. To calculate the wear volume at one contact, the wear range ratio during one cycle is used. The total wear volume is then determined by accumulating the wear volume at every contact. The fractional film defect coefficient, asperity load sharing factor, and modified specific wear rate for the application of the mixed-elasto-hydrodynamic lubrication regime are used. The results of this study show that wear occurs only at the connecting-rod big-end bearing. Thus, simulation results of only the big-end bearing are illustrated and analyzed. It is shown that the wear volume of each wear scar group occurs consecutively as the crank angle changes, resulting in the total accumulated wear volume.