• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.87-89
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• 2014

Spherically expanding flames are used to measure flame speeds, which are derived the corresponding laminar flame speeds at zero stretch. Flame speeds of n-butanol at high pressure are studied over an extensive range of equivalence ratios. The classical shadowgraph technique is used to detect the reaction zone. In analytical methodology the optimization process using least mean squares is performed to extract the laminar flame speeds. Laminar flame speeds are compared with results obtained from numerical work.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.837-843
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• 1999

A common hydraulic jack using brdige retrofit has a problem of increasing cost and time of construction to construct additionally temporary bent or concrete bracket, in case of insufficiency work space and release hydraulic pressure. To solve the problem, this technique is developed to alternate the bridge bearing in adequate inspection condition. After control maximum lift-height and minimum lift-force of no damage to super structure, the constructive technique is to alternate and repair the bridge bearing using the wedge jack with bridge bearing ability that is no release hydraulic pressure stopper, and able to reuse separable cylinder.

• Tribology and Lubricants
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• v.16 no.6
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• pp.432-439
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• 2000

The present work is an attempt to calculate the steady state pressure and perturbed pressure of herringbone grooved journal bearings. A generalized coordinate system is introduced to handle the complex bearing geometry. The coordinates are fitted to the groove boundary and the Reynold's equation is transformed to be fitted to this coordinate system using the Gauss divergence theorem. This method makes it possible to deal with an arbitrary configuration of a lubricated surface. The caharacteristics of finite herringbone groove journal bearing are well calculated using this method.

• Journal of the Korean Society of Marine Environment & Safety
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• v.6 no.1
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• pp.69-76
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• 2000

Bubble boom may be a good alternative for the prevention of oil spill pollution due to its easy deployment and clean post-process tasks. The present work is focused on the experimental investigation of air bubble movement for the bubble boom by visualization and quantitative PIV measurements. Bubble plume was generated by adjusting the pressure of pressure vessel ranging 6.7 kpa to 14.7 kpa. The results showed at lower inlet velocity and higher supply air flow rate that bubble boom maintained its containing capability reasonably well up to the maximum containing limit.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1998.04a
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• pp.130-135
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• 1998

The Reciprocating compressor are widely used in the refrigeration field for its simplicity in principle and high efficiency. In this work, we developed a mathematical model of a reciprocating compressor. The suction and discharge valves are modeled by the spring-mass-damper systems. The working fluid flow is derived from unsteady Bernoulli's equation. With the design parameters, the valve motions and pressure fluctuations are studied numerically and experimentally.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.302-307
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• 1989

A pressure tracking control of hydroforming process is considered in this paper. To account for nonlinearities and uncertainties of the process, an iterative learning control scheme is proposed using Cerebellar Model Arithmatic Computer (CMAC). The experimental result shows that the proposed learning control is superior to any fixed gain controller in the sense that it enables the system to do the same work more effectively as the number of operation increases.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.604-607
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• 2000

All of rubber tubes for force pump are imported from aboard there for locallization of these tubes is make a great contribution of Korean industry In this study compare with existing product of japan and designed the new one that is for our actual circumstances. Experimental work was performed to two kinds of specimen and compression test is performed for them. As a result specimen type A has a better restoration than other and minimum thickness is must over 12mm.

• Tribology and Lubricants
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• v.17 no.1
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• pp.1-9
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• 2001

Hard disk drives operate in various environmental conditions. Thus, it is necessary to assess the reliability of the head/disk interface under these conditions. In this work, stiction and acoustic emission signals were investigated under different temperature, humidity, and ambient pressure conditions. Also, track average amplitude was observed for disk failure in N$_2$environment. It is shown that failure of the head/disk interface occurs more readily at high temperature and low ambient pressure conditions.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.18-19
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• 2006

To improve the properties of fine metal powder, such as particle size distribution and geometric standard deviation, this work was done at various atomizing conditions. The new atomization mechanism and the correlation equation were proposed to estimate the mean particle diameter.

• Journal of the Korean Wood Science and Technology
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• v.32 no.3
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• pp.25-32
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• 2004

This research work explored physical and mechanical properties of impregnated sawdust boards from three softwood species (P, densifora, L. kaemferi, and P. koraiensis) with phenol-formaldehyde (PF) resin by various vacuum treatment methods of combining pressure, vacuum, and ultrasonic waves. Simultaneous vacuum and ultrasonic wave treatments with no pressure resulted in the greatest increase in resin content, density, dimensional changes (thickness and length), bending strength, and hardness of impregnated board. This result seemed to be attributed to the ultrasonic wave treatment.