• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.88-90
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• 2003

We reported an AC PDP structure with grooved front panel dielectric layer. The structure exhibits low breakdown voltage, better luminance, and better endurance to crosstalk in high Xe contents. It also shows less luminous efficacy then conventional structure because of the thinner dielectric layer, but we can apply the higher Xe contents to the grooved dielectric structure, which results in the higher luminous efficacy. We made experiments with the Xe contents from 4 to16% and total gas pressure from 400 to 600Torr. The grooved dielectric structure shows the improvement of 20% luminous efficacy and 17% luminance. The firing voltages lower about 40V at 600Torr and Xe 12, 16%. The discharge characteristics of grooved dielectric structure are verified also with 2D simulation.

• International Journal of Aeronautical and Space Sciences
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• 제8권1호
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• pp.87-94
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• 2007

Tilt rotor-wing concept to show enhanced performance in low speed mission is presented. Three types of stud wings on the existing tilt rotor configuration are suggested and their characteristics are compared. Aerodynamic analysis indicates that the stud wing concept gives significant performance improvement on the endurance and range in the low speed regime when compared with the tilt rotor. Penalties of the stud wing are discussed from the perspectives of conversion corridor, structural weight, configuration design, and cross wind stability. This study concludes that the advantage of the stud wing in general UAV mission performance is so significant as to surpass the penalties in other perspectives investigated.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 후기학술대회논문집
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• pp.224-225
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• 2005

The lightness of components required on marine and shipbuilding industry is requiring high strength of components. In particular, fatigue failure phenomena, which happen in metal, bring on danger in human life and property. Therefore, antifatigue failure technology takes an important part of current industries. In this study, it was investigated about endurance and fatigue crack propagation rate of according to stress ratio of SMAW commonly using for welding structures in present. Fatigue crack propagation rate(da/dN) of low load(R=0.1) was lower than of high load(R=0.6) for piping weld. And in stage I, ${\Delta}$Kth, the threshold stress intensity factor of the weld under heavy load is higher than under small load. Fatigue life shows more improvement in the weld of stress ratio R=0.l than in the weld of stress ratio R=0.6.

• IEIE Transactions on Smart Processing and Computing
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• 제5권5호
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• pp.337-345
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• 2016

Recently, as the number of cores in computer systems has increased, the need for larger memory capacity has also increased. Unfortunately, dynamic random access memory (DRAM), popularly used as main memory for decades, now faces a scalability limitation. Phase change memory (PCM) is considered one of the strong alternatives to DRAM due to its advantages, such as high scalability, non-volatility, low idle power, and so on. However, since PCM suffers from short write endurance, direct use of PCM in main memory incurs a significant problem due to its short lifetime. To solve the lifetime limitation, many studies have focused on reducing the number of bit flips per write request. In this paper, we describe the PCM operating principles in detail and explore various bit flip reduction schemes. Also, we compare their performance in terms of bit reduction rate and lifetime improvement.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.603-608
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• 2001

Recently, cold expansion of fastener holes is commonly used in the aerospace industry to increase the fatigue endurance of airframes. Cold expansion process is used as the retardation of crack initiation in the hole. This treatment leads to an improvement of fatigue behavior due to the compressive residual stresses developed on the hole surface. The residual stress profile depends on the cold expansion ratio. In the present paper, it is shown that residual stress is redistributed due to the application of cold expansion process for CT specimen. It is further shown that residual stress increases in proportion to cold expansion ratio. It is thought that crack growth rate increases as cold expansion ratio.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2002년도 제25회 KOSCI SYMPOSIUM 논문집
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• pp.65-69
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• 2002

Catalytic combustion known as one of the traditional oxidation methods of VOC gas is restricted to its applicable fields because of its reaction characteristics. But recently innovative improvement of catalytic endurance makes its applicable range broader from MEMs to industrial power generation. Therefore, control technologies based on the catalytic combustion characteristics are researched and developed dynamically. Especially, the stable control of catalytic combustion is an essential factor in a view of maximizing its efficiency. In this research, the fuel equivalence ratio and the preheating temperature of mixture gas is controlled by catalytic combustion system enhanced in heat transfer with high temperature heat exchanger. As a result, the combustion characteristics of system was investigated, and both passive and active control type were compared and analyzed.

• 펄프종이기술
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• 제44권1호
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• pp.58-64
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• 2012

As a first step to apply PVAm (polyvinylamine) on packaging paper by surface treatment, three types of linerboards were impregnated with PVAm solution. The effect of PVAm pick-up on strength properties of linerboard was investigated. The pick-up of PVAm was controlled by varying concentration of PVAm solution. It was found that dry tensile strength, tensile energy absorption, burst strength and compressive strength of linerboard were increased by applying PVAm. In addition, wet tensile strength was significantly improved with increasing PVAm pick-up. However, folding endurance was found to be decreased with increasing PVAm pick-up.

• 한국유체기계학회 논문집
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• 제7권1호
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• pp.9-16
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• 2004

A three-dimensional numerical analysis was carried out on incompressible flows in butterfly valves by using commercial FLUENT/UNS code. Characteristics of complex flows including cavitation effect were investigated for different valve disk angles. The butterfly-valves that had different disk angles and different disk shapes were compared with each other in detail. This study focused on the flow analysis in the conventional butterfly valve and the newly designed butterfly valve in order to prevent cavitation. The newly designed valve shows great improvement on performance and endurance.

• 항공우주기술
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• 제1권2호
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• pp.179-185
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• 2002

본 연구는 장기체공성 향상을 위한 개량형 무인기의 구조설계에 관한 방법 및 절차를 소개한 것이다. 상온 경화용 복합재료를 날개 전체에 적용하였다. 운반 및 보관의 용이성을 고려하여 날개 구조물을 3개로 분리하였고, 구조물의 경량화 및 강성의 증가를 위하여 샌드위치 구조물을 스킨 전영역에 적용하였고, 제한하중 4g에 해당되는 하중조건에서 구조강도시험을 수행하여 구조설계와 제작성을 점검하였다.

• The Journal of Korean Physical Therapy
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• 제18권6호
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• pp.1-11
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• 2006

연구목적: 이 연구는 피부표면 냉각이 생체내의 건구조 점탄성 특성에 미치는 영향을 비교하였다. 방법: 7명의 남성 실험 대상자는 족저굴곡 운동을 10회$\times$10set, 60초 간격으로 최대 수의적 수축을 6초간 각각 실시하였다. 각 측정 전후에 내측 비복근(MG)의 건과 건막의 신장은 초음파 검사법에 의하여 직접 측정되었다(건 장력과 건 신장의 관계로 평가 되었다). 건 횡단면적과 족 관절 모멘트 암은 자기공명영상법(MRI)으로부터 얻어졌다. 건 장력은 관절 모멘트와 건 모멘트 암으로 계산되었다. 또한 스트레스는 횡단면적영역(CSA)을 힘으로 나눔으로써 얻어졌다. 스트레인은 건의 길이로 표준화된 치환으로부터 측정되었다. 결과: 냉각 후에 건 장력은, 비냉각 보다 냉각한 측이 유의하게 높았다. 스티프네스는 비냉각 조건 보다 냉각 조건하에서 높은 유의수준을 나타냈다. 최대의 스트레인과 스트레스는 냉각조건하에서 $7.4{\pm}0.7$와 $36.4{\pm}1.8$ MPa을 나타냈고, 비냉각 조건하가 $7.8{\pm}8.5$ 와 $31.8{\pm}1.1$ MPa (p<0.05)을 나타냈다. 결론: 이 연구의 결과는 피부표면 냉각으로 인해 인간의 근지구력이 건 스티프네스와 탄성률을 증가시키는 것을 시사하는 연구라 하겠다. 피부 표면 냉각으로 인한 근지구력의 개선이 근과 건에 직접적인 영향을 미침을 나타내주고 있다.