• JSTS:Journal of Semiconductor Technology and Science
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• v.7 no.3
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• pp.133-139
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• 2007

Future MEMS systems will be composed of larger varieties of devices with very different functionality such as electronics, mechanics, optics and bio-chemistry. Integration technology of heterogeneous devices must be developed. This article first deals with the current development trend of new fabrication technologies; those include self-assembling of parts over a large area, wafer-scale encapsulation by wafer-bonding, nano imprinting, and roll-to-roll printing. In the latter half of the article, the concept towards the heterogeneous integration of devices and functionality into micro/nano systems is described. The key idea is to combine the conventional top-down technologies and the novel bottom-up technologies for building nano systems. A simple example is the carbon nano tube interconnection that is grown in the via-hole of a VLSI chip. In the laboratory level, the position-specific self-assembly of nano parts on a DNA template was demonstrated through hybridization of probe DNA segments attached to the parts. Also, bio molecular motors were incorporated in a micro fluidic system and utilized as a nano actuator for transporting objects in the channel.

• Bulletin of the Society of Naval Architects of Korea
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• v.24 no.4
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• pp.1-8
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• 1987

In this paper negative drift forces are discussed, which act on a two-dimensional cylinder exposed to slightly modulated waves in water of finite depth. By combining matched asymptotic expansion method with multiple scale technique, it is clearly shown that the slowly-varying drift force can be negative under certain circumstances: i) Incident waves are irregular or slightly modulated. ii) The water depth is finite compared to the wave length of carrier waves. iii) The gap between the keel of the cylinder and ocean floor is narrow. Then the negative drift forces are caused by the unbalance of hydrostatic force associated with set down. Real fluid and wave breaking effects are not considered.

• Journal of the Korean Home Economics Association
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• v.30 no.1
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• pp.49-65
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• 1992

The writer did a survey of current textile patterns for the purpose of identifying a motif trend. After identifying a current motif trend the writer used an IBM PC 386 Computer and Lumena Software to design actual patterns. The results are as follows: 1. The most common currently used prints are floral patterns. 2. Knowing that floral patterns are most popular, the writer established a motif using the Rose of Sharon, the national flower of Korea. 3. Using computer graphics to move, enlarge and scale-down motif, the writer has been able to design various textile patterns. 4. Creating patterns with computer graphics was not only more efficient, but it also produced more accurate designs and a greater variety of designs. 5. Using the many computer graphic functions avaliable, a greater variety of patterns changes and compositions can be displayed than would be possible if produce by hand. 6. Computer simulations of textiles and clothing made it possible to evaluate the printed fabric or finished product. Faults in the printed fabric or clothing could be corrented before production. Through simulation then it is possible to create higher quality garments and readuce costly mistakes. Thereby greater profits will be realized from the finished garments.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.240-243
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• 2002

In this paper, we propose a face region detection based on skin-color distribution and facial feature extraction algorithm in color still images. To extract face region, we transform color using general skin-color distribution. Facial features are extracted by edge transformation. This detection process reduces calculation time by a scale-down scanning from segmented region. we can detect face region in various facial Expression, skin-color deference and tilted face images.

• Journal of computational fluids engineering
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• v.14 no.2
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• pp.77-83
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• 2009

Operating medium or large scale industrial boilers in partial load condition, the burner should undergo the off-design points resulting in poor exhaust gas characteristics. To obtain the stable turn down performance, two or more burners can be used for the industrial boiler. In case multiple burners are adopted, the heat transfer can be enhanced by arranging the burners properly. In the present study, numerical simulations have been conducted for the combustion chamber of a 2 t/h class industrial boiler in order to clarify the heat transfer characteristics at the combustion chamber.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.569-572
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• 2010

In order to study the performance characteristics of the thrust vector nozzle, the test facility and instrumentation system were designed. In this system, axial thrust, moment, exhaust gas velocity and pressure will be measured by using the scale down experimental model devices. The test facility are composed of high pressure air storage system, flow measuring and control system, test nozzle and thrust measurement system.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1280-1285
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• 2004

Microsystem technology has been applied to space technology and became one of the enabling technology by which low cost and high efficiency are achievable. Micro propulsion system is a key technology in the miniature satellite because micro satellite requires very small and precise thrust force for maneuvering and attitude control. In this paper research on micro solid propellant thruster is reported. Micro solid propellant thruster has four basic components; micro combustion chamber, micro nozzle, solid propellant and micro igniter. In this research igniter, solid propellant and combustion chamber are focused. Micro igniter was fabricated through typical micromachining and evaluated. The characteristic of solid propellant was investigated to observe burning characteristic and to obtain burning velocity. Change of thrust force and the amount of energy loss following scale down at micro combustion chamber were estimated by numerical simulation based on empirical data and through the calculation normalized specific impulses were compared to figure out the efficiency of combustion chamber.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.1
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• pp.55-62
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• 2002

In this paper, several types of infiltration prevention devices that are currently in use have been studied through experimental investigation. Firstly, the types of infiltration prevention devices were defined through investigating actual conditions of refrigerated warehouse in operates. Based on this investigation results, measured change of temperature and figured out air change rates of the type of infiltration prevention devices by using scale down model. After that, found the amount of air change rate in order to estimate the load of air change easily in facility plan.

• Transactions on Electrical and Electronic Materials
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• v.3 no.3
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• pp.14-17
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• 2002

The HDP (High Density Plasma) CVD process consists of a simultaneous sputter etch and chemical vapor deposition. As CMOS process continues to scale down to sub- quarter micron technology, HDP process has been widely used fur the gap-fill of small geometry metal spacing in inter-metal dielectric process. However, HBP CVD system has some potential problems including plasma-induced damage. Plasma-induced gate oxide damage has been an increasingly important issue for integrated circuit process technology. In this paper, thin gate oxide charge damage caused by HDP deposition of inter-metal dielectric was studied. Multiple step HDP deposition process was demonstrated in this work to prevent plasma-induced damage by introducing an in-situ top SiH$_4$ unbiased liner deposition before conventional deposition.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.419-421
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• 2003

송전선로에서 발생하는 전자계에 대한 관심이 증가함에 따라 이를 저감하는 방법에 대한 연구도 활발하게 진행되고 있다. 본 논문에서는 송전선로에 적용할 수 있는 전자계 저감방법중 하나인 수동루프에 대한 성능을 송전선로의 축소모형 실험을 통해 나타내고 그에 대한 결과를 이론적인 계산 값과 비교하였다. 약 1/20 크기로 축소한 송전선로 모형을 제작한 다음 몇 가지 전압, 전류를 인가하여 선로 주변 전자계를 측정하여 그 결과를 정리하였다.