• Journal of the Microelectronics and Packaging Society
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• v.6 no.2
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• pp.63-68
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• 1999

We have fabricated $WO_3$ thick film gas sensor under various firing conditions in order to study gas sensing properties in terms of the variation of microstructure and non-stoichiometric structure of gas sensing layer. $WO_3$ paste mixed homogeneously with organic vehicle was coated by screen printing method on alumina substrate composed of Au electrode and $RuO_2$heater on each side. To change filing condition, sensing materials were fared at 600-$800^{\circ}C$ for 1 hour and refired at $700^{\circ}C$ for 1 hour in the mixtures of $_Ar/O2$gas. In the result of heat-treatment, $WO_3$ gas sensor fared at $700^{\circ}C$ showed best gas sensing properties of 210 gas sensitivity and 2 second response time and the best firing environment was 40-50% of $Ar/O_2$gas.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.6
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• pp.1-9
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• 2020

Using kerosene and liquid oxygen, 1.5-tonf class liquid-liquid pintle injector with rectangular two-row orifice was designed and manufactured. The combustion test of the pintle injector was carried out to verify the combustion performance and combustion stability under a supercritical condition which is the actual operation condition of the liquid rocket engine. The combustion test result showed that the pintle tip was damaged by the high temperature combustion gas in the high-mixed ratio recirculation zone of the combustion chamber. To solve this problem, the insert nozzle was installed in the pintle injector to increase cooling performance at the pintle tip. As a result of the hot firing test, installation of the insert nozzle, AR and BF had a great effect on pintle tip cooling performance.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.459-464
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• 2004

The rifle impact of human body affected by the posture of human for rifling. The interaction human-rifle system influence the firing accuracy. In this paper, impact analysis of human model for shooting posture is carried out. ADAMS code and LifeMOD is used in impact analysis of human model and modeling of the human body, respectively. On the shooting, human model is affected by rifle impact during the 0.001 second. Performed simulation time for shooting is 0.1 second. Applied constraint condition to human-rifle system is rotating and spherical condition. As the results, the displacement of rifle and transfer path analysis of impact of human model is presented.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.649-653
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• 2006

Engine Noise is composed of the mechanical and combustion noise. The contribution of combustion noise is generally bigger than the contribution of the mechanical noise at idle condition in DI diesel engine. That noise usually makes a roughness problem at the fundamental engine order. It is difficult to remove the modulation frequency so we have to directly reduce the combustion noise. The key effect of combustion noise reducing solution is the modification of the combustion pressure profile. It is accomplished by the multiple injection method and we solved the 400Hz combustion noise and improved the sound quality at idle condition in DI diesel engine.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.3
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• pp.28-38
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• 2003

Finite element analysis of cylinder heat/block compound under assembly, thermal and firing condition were performed. FE model including two cylinders with gasket, head bolts, liners and valve seats was used. FE modeling method and boundary conditions were introduced. Stress distribution and deformation of cylinder head and block under each loading condition were presented. Gasket pressure distribution and bore distortion level were predicted. Measured data of bore distortion was compared with the analysis results. The analysis result showed similar trends with the experimental data. High cycle fatigue analysis on the basis of this result has been performed in order to find the critical areas of the engine assembly.

• Journal of the Korean Professional Engineers Association
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• v.23 no.6
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• pp.41-46
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• 1990

First of all, Under given condition such as bit gage of 36mm Drill bit with right class of jack-logs experimental test carried out from two face of Bench, firing of each hole brought 90 degree Angle face and them measured length of Burden and charged ammount of powder as following. (equation omitted) A=Activated Area A=ndi=m S=Peripheral length of Charged. room Ca=Rock Coeffiecency d : di=Hole diameter When constructed subway of Seoul in 1980 the blasting works increased complaint of ground vibration. in order to prevent the damage to structures. Some empirical equations were made as follows on condition with Jackleg Drill (Bit Gage ø 36mm) and within 30 meter distance between blasting site and structures. V=K(D / W)$\^$-n/ N=1.60-1.78 K=48-138 Project one of contineous works to above a determination of empirical equation on the cautious blasting vibration with Crawler Drill(ø 70-75mm) in long distance. V=41(equation omitted) V=124(equation omitted).

• Journal of Power System Engineering
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• v.13 no.5
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• pp.82-88
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• 2009

The purpose of this paper is to provide technical background, techniques and actual diesel engine signature analysis evaluation result. Engine signature analysis(ESA) is a process for monitoring the material condition of diesel engine using external sensors, eliminating the need to periodically disassemble the engine. ESA is also used to balanced the engine. Engine balancing is the process of tuning the engine so that all cylinders carry equal load. ESA is a useful tool to non-intrusively determine the operability and performance and assessment of the material condition of internal component of a diesel engine.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.707-710
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• 2008

The method suggested in this thesis is the safe and economic method when testing rocket engine because ground test facility copies high altitude. We have decided to use the schematic of testing facility based on already known design method and test result, and we have decided the test condition for ground firing test of solid fuel. In addition the pressure of nozzle exit area is 0.1bar, we have designed the testing facility structure to test in this condition. Moreover, we have designed to reduce the accident probability.

• Explosives and Blasting
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• v.8 no.3
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• pp.3-13
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• 1990

First ot of all, under given condition such as bit gage of 36mm Drill bit with right class of jack-leg-experimental test carried out from two face of Bench, firing of each hole brought 90 degree Angle face and them measured length of Burden and charged ammount of powder as following. $ca=\frac{A}{SW}$ A=Activated Area A=nd i=m S=Peripheral length of charged, room Ca=Rock Coeffiecency d: di=Hole diameter When constructed subway of Seoul in 1980 the blasting works increased complaint of ground vibration, in order to prevent the damage to structures. Some empirical equations were made as follows on condition with Jackleg Drill (Bit Gage 36mm) and within 30 meter distance between blasting site and structures. $V=K(D/W)^{-n}$ N=1.60 - 1.78 K= 48 - 138 Project is one of contineous works to above a determination of empirical equation on the cautious blasting vibration with Crawler Drill (70-75mm) in long distance. $V=41(D/\sqrt[3]{W})^{-1.41}$ $30m\le{D}\le{100m}$ $V=124(D/\sqrt[3]{W})^{-1.66}$ $100m\le{D}\le{285m}$.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.4
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• pp.416-424
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• 2016

A robust design of head gasket is pursued by using FEA model of engine assembly. Engine assembly model consists of cylinder head, block, gasket, and head bolt is constructed to understand a complex behavior of this engine compound. Thermal loading is performed on the assembled engine cylinder and block to obtain temperature field. Firing load is added to the results of heat transfer analysis to simulate the engine operation condition. Temperature filed results from heat transfer analysis are mapped into the structural mesh. Contact pressure distribution along the bead has been monitored for the engine operation condition. Based on the results obtained from the analysis, Taguchi method has been adopted for a robust design process of head gasket. Among the control factors, bolt size affects most robustness of head gasket sealing.