• Journal of the Korean institute of surface engineering
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• v.29 no.6
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• pp.803-808
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• 1996

Material and electrical characteristies of copper thin films prepared by metal organic chemical vapor deposition (MOCVD) have been investigated for interconnection applications in ultra large scale integration circuits (ULSI). The copper films have been deposited a TiN substrates using a metal organic precursor, hexafluoro acetylacetonate trimethyvinylsilane copper, VTMS(hfac)Cu (I). Deposition rate, grain size, surface morphology, and electrical resistvity of the copper films have been measuredfrom samples prepared at various experimental conditions, which include substrate temperature, chamber pressure, and carrier gas flow rate. Results of the experiment showed that the electrical property of the copper films is closely related to the crystallinity of the films. Lowest electrical resistivity, $2.4{\mu}{\Omega}.cm$ was obtained at the substrate temperature of $180^{\circ}C$, but the resistivity slightly increased with increasing substrate temperature due to the carbon content along the copper grain boundaries.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.5 s.98
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• pp.74-82
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• 1999

To meet the needs of the hydraulic excavator of large capacity, tandem axial type piston pump which is high pressure and high speed have been developed. But inevitably we can not help facing the problem of noise at that time. In order to reduce the noise of this pump, many researchers have been studying the problem of oil distribution manner. But they are not interested in the symmetric structure of tandem type pump. So, focusing on the symmetric structure of tandem type pump, this paper analyzed unbalanced force developed in the pump chamber and verified the effect of the pumping phase of the piston on vibration and noise of the tandem axial type piston pump theoretically.

• Korean Journal of Veterinary Research
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• v.20 no.2
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• pp.93-97
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• 1980

To observe sequential postmortem autolysis in liver of Korean native cattle, liver placed in controlled environment chamber at $23-27.5^{\circ}C$ was treated after various intervals and observed with light microscope. The nuclear fading accompanied by margination of the chromatin in the hepatocytes appeared by 3 to 6 hours, and reduction of the cytoplasmic stainability and haryolisis began at 15 hours after death. Pyknosis of Kupffer's cells was noted by 3 to 20 hours, thereafter followed the decrease in staining of nuclei, but the nuclei were visible until 50 hours after death. Sinusoids and space of Disse were markedly distended at 10 hours, thereafter spaces of Disse were more dilatable than sinusoids. A large number of the erythrocytes in blood vessels were lysed, and the cytoplasmic stainability was largely reduced at 25 hours and nearly disappeared at 40 hours after death.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1404-1408
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• 2006

In this paper, a hybrid-type vibration isolator which has air chamber(spring) and viscous damper in series is developed. The developed vibration isolator is designed to perform 3 following functions : spring function for normal operating conditions, damping function to reduce an impact for sudden move of upper beam, and finally leveling function. Based on the given natural frequency and damping factor, the design procedure is proposed. The performance of the developed isolator is tested by measuring stiffness and damping.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.5
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• pp.25-31
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• 2004

In order to prepare for the large power diesel vehicle, the current trend of advanced nations is to shift from the aluminum alloy piston to the steel piston. In this research, a steel forging piston which replaces the aluminum alloy piston is developed to improve the power performance of the diesel engine. The three dimensional flow and combustion analysis of the target engine is conducted. Using the result of the analysis, the piston is optimized, and a prototype of the articulated steel forging piston is built. The reliability of the piston has been evaluated through durability test using a Hydropuls Test Machine for 300,000 km.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09b
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• pp.141-146
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• 2010

To investigate the effect of drainage spacing and smear on the rate of consolidation, a large consolidation chamber and mandrel insertion device were developed. After the occurrence of smear by installation of sand drain, model ground was consolidated in either overconsolidated or normally consolidated state. As smear effect increases and thus drain spacing decreases, total settlement increase in overconsolidated state but has no effect in normally consolidated state. Efficiency of vertical drain decreases and consequently consolidation time increases in all tests as smear effect becomes significant.

• Journal of Hydrogen and New Energy
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• v.12 no.2
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• pp.147-155
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• 2001

To measure of thermal loading in the combustion chamber of hydrogen engine with dual injection, instantaneous wall-surface temperature and unsteady heat flux of the cylinder head are measured and analyzed. The maximum wall surface temperature is shown in direct injection region which has large heat supplied. Partial and spatial temperatures have slight deviation in transient region of injection, though injection method change suddenly. All of thermal characteristics such as instantaneous temperature, temperature swing and heat flux of hydrogen engine with dual injection are remarkably higher than those of gasoline engine. It means necessity of additional countermeasure of thermal loading.

• Proceedings of the Safety Management and Science Conference
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• 2003.11a
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• pp.97-103
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• 2003

In recent years, environments of business are changing due to epoch-making development of information technology and the advent of digital economy ages. It is an active confrontation as to the environments for information. Unlike the large scale enterprises in those days, hower, many small & medium enterprises especially the enterprises which are engaged in the manufacturing industry-aren't participate in information's rank due to the lack of funds, manpower, insufficient management environments, and manager or staff's lack of cognition as to information. So, this paper make a base of establishment for ISP through the establishment of ERP that is used to management activity for small & medium manufacturing enterprises. A way for small & medium enterprises' ERP construction is SMERP S/W for the small & medium enterprises' ERP package which is offered by the Korea chamber of commerce & industry. And, that is applied to the real management environment.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.8
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• pp.787-795
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• 2001

An experimentation on the on-line fault detection and diagnosis(FDD) system has been performed with HVAC system in he experimental building constructed inside the large scale environmental chamber. Personal computer with a home-made FDD program by pattern recognition method utilizing artificial neural network was connected on-line via Ether-net TCP/IP to the supervisory control server for HVAC system. The FDD program monitored the HVAC system by 1 minuted interval. The results showed that he FDD program detected the sudden or abrupt faults such s those in fans, sensors and heater, etc.

• Solar Energy
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• v.12 no.3
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• pp.84-93
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• 1992

Solar assisted heat pump with freon circulating system has been developed. Revising the cool chamber(flower storage) with the solar thermal hot water producing system, the more amount of hot water can be produced, which can be even used for room panel heating. The compressor was cooled by water jaket instead of air cooled so that the system energy efficiency was improved quite well.