• ALGAE
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• 제21권1호
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• pp.83-90
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• 2006

Phytoplankton community in the coastal waters off the northeastern Korean Peninsula were characterized from May 2002 to August 2003. Taxonomic composition, abundance and biomass were determined at two water depths at 10 sample sites. A total of 153 phytoplankton species including 121 diatoms, 28 dinoflagellates, 7 green algae and 7 other species were identified. The mean abundance of phytoplankton varied from 15 to 430 cells mL–1 in the surface layer and from 11 to 545 cells mL–1 in the bottom layer, respectively. Phytoplankton was more abundant in coastal stations relative to those in more open ocean. The most dominant species were marine diatoms such as Thalassionema nitzschioides, Licmorphora abbreviata, Chaetoceros affinis and Chaetoceros socialis. In addition, a few limnotic diatoms including Fragilaria capucina v. rumpens, the green alga Scenedesmus dimorphus, some marine dinoflagellates and Cryptomonas sp. appeared as dominant species. Mean concentration of total chlorophyll-a varied from 0.22 to 7.87 μg chl-a L–1 and from 0.45 to 6.79 μg chl-a L–1 in the surface and bottom layers, respectively. The contribution of phytoplankton each size-fractionated varied highly with season. The contribution of microphytoplankton to total biomass of phytoplankton in the surface and bottom layer was high in February and August 2003, and that of nano-phytoplankton was high in May 2002 in both surface and bottom layers.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.105-110
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• 2001

It has recently been raised main issue how solve the problem of insufficient energy. One of the solution is to increase the thermal efficiency of power generation system. For the purpose of high efficiency, it is necessary to increase the steam temperature and pressure. So, the use of modified $9{\sim}12%Cr$ steel having superior creep rupture strength and oxidation resistance is required to endure such severe environment. The evaluation of creep properties of those heat resistance material is very important to secure the reliability of high temperature and pressure structural components. Since creep properties are determined by microstructural change such as carbide precipitation and coarsening, It is certain that there are some relationship between creep properties and hardness affected by microstructure. In this study, SP-Creep ruptured test for newly developed 9Cr steel being used as boiler valve material was performed, and creep properties of the material were evaluated. Also, hardness test were performed and hardness results were related to the creep properties such as LMP and creep strength to verify the availability of SP-Creep test as creep test method.

• 복식
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• 제53권5호
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• pp.79-95
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• 2003

The purpose of this study is firstly to survey the social and cultural background of 20th century and women´s status, and to identify what the ideal body is like and what the elements of outer garment and underwear are and the techniques to incarnate the ideal beauty. Various papers are referenced for theoretical study and the elements and techniques of underwear are analyzed based on photographical materials. This paper concludes as follows. In 1960´s, ideal beauty was small bust, long legs, which showed extremely slim Mini-skirt look. Thinly or no padded brassiere were worn for small bust, and pants-style short panty girdles were popular as they used to wear pants frequently. Lycra replaced all the closures, bones, seams and gave freedom with light weight. In 1970´s, a natural human body without sex specific was in vogue. Therefore, the non-structural knits without a pad or lining or the shirts dress were widespread for a Natural look and the naturally molded brassiere or girdles were worn as the underwears. In 1980´s, the women with powerful muscle appear which emphasized liveliness and healthfulness. The body conscious represented by wide shoulder, plump breast, accented waist, small hips, and long legs has been embodied. Outer garments emphasized women power and healthy beauty with Power suit and Form-fitting style, and underwears made the breast plump with padded brassiere and emphasized waist and hips with waspie. In 1990´s, ideal beauty was slim body with big bust and the outer garments emphasized body line of women with Hourglass silhouette. Push-up bra which emphasizes the valley of breast and supports the breast upward and the control tights for slim waist, flat abdomen, small hips, and long and slim legs have been useful as underwears. Multi-functional micro-fiber has been ideal for sculpting women body.

• 마이크로전자및패키징학회지
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• 제21권2호
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• pp.37-41
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• 2014

차세대 전자 소자 기술에서 전력전달은 소자의 전력을 낮추고 발열로 인한 문제 해결을 위해서 매우 중요한 기술로 대두되고 있다. 본 연구에서는 직사각형 ABL 전력 범프를 이용한, Cu-to-Cu 플립 칩 본딩 공정의 신뢰성 문제에 대해 살펴보았다. 다이 내 범프 높이 차이는 전기도금 후 CMP 공정을 진행했을 경우 약 $0.3{\sim}0.5{\mu}m$ 이었고, CMP 공정을 진행하지 않았을 경우는 약 $1.1{\sim}1.4{\mu}m$으로 나타났다. 또한 면적이 큰 ABL 전력 범프가 입출력 범프 보다 높이가 높게 나타났다. 다이 내 범프 높이 차이로 인해 플립 칩 본딩 공정 시 misalignment 문제가 발생하였고, 이는 본딩 quality 에도 영향을 미쳤다. Cu-to-Cu 플립 칩 공정을 위해선 다이 내 범프 높이 균일도와 Cu 범프의 평탄도 조절이 매우 중요한 요소라 하겠다.

• 한국전기전자재료학회논문지
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• 제25권1호
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• pp.62-67
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• 2012

Owing to the rapid growth of mobile and electronic equipment miniaturization technology, the supply of micro mobile computing machine has been fast raised. Accordingly they have performed many researches on energy harvesting technology to provide promising power supply equipment to substitute existing batteries. In this paper, in order to have low resonance frequency for piezoelectric energy harvester, we have tried to make it larger than before by adopting nickel that has much higher density than silicon. We have applied it for our energy harvesting actuator instead of the existing silicon based actuator. Through such new concept and approach, we have designed energy harvesting device and made it personally by making with micromachining process. The energy harvester structure has a cantilever type and has a dimension of $10{\times}2.5{\times}0.1\;mm^3$ for length, width and thickness respectively. Its electrode type is formed by using Au/Ti of interdigitate d33 mode. The pattern size and gap size is 50 ${\mu}m$. Based on the measurement of the nickel-based piezoelectric energy harvester, it is found to have 778 Hz for a resonant frequency with no proof mass. In that resonance frequency we could get a maximum output power of 76 ${\mu}W$ at 4.8 $M{\Omega}$ being applied with 1 g acceleration.

• 대한기계학회논문집A
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• 제38권8호
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• pp.893-898
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• 2014

펄스 레이저를 적용한 실버나노와이어의 접합 영향이 연구되었다. 조사된 레이저 펄스 에너지는 실버나노와이어 네트워크에서 실버나노와이어간에 접합을 유도하였으며 이로 인해 투명 기저위의 실버나노와이어 네트워크 박막에 전기 저항값을 조절할 수 있었다. 특히 이러한 나노네트워크에서의 접합은 개별 나노와이어의 접촉점의 형태로 발생되었고 접합의 효과는 전체 실버나노와이어 네트워크의 전기저항 변화 측정으로 평가하였다. 또한 레이저 빔 펄스폭 및 레이저 평균 출력이 나노와이어 접합 비율 평가에 적용되어 연구되었다. 실버나노와이어 네트워크의 광학 특성도 관찰되었으며 이에 레이저 공정 요소 대비 효과도 연구되었다. 최적화된 레이저빔 적용 재료처리는 특화된 국부 재료 특성 개선에 장점을 보였다. 펄스 레이저를 이용한 실버나노와이어의 재료처리의 적용과 그 효과에 대해서도 논의한다.

• Asian Journal for Public Opinion Research
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• 제5권1호
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• pp.41-62
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• 2017

The political reformation in Indonesia is a determinant factor of the change in political communications and the roles of media. Currently, the political elites need media support, since it contextually has a significant role. Whoever has a good relationship with the media, will be loved by the public. On the other hand, the media also have a vested interest in the elite in running businesses and building the power of industry. Policies and capital pose a challenge to maintaining the continuity of the media. Independence and control of media are at stake, when the interests of the media and the elite collaborate with each other and then build a benefit on both sides. Meanwhile, the role of social media also cannot be neglected. The Indonesian political communication system is characterized by the presence of social media in a pseudo-relationship between the elite and the public. This paper tries to explain the growing trends of research in the academic environment and the research trends in political practice in Indonesia after the occurrence of post-reformation era in legislative and executive elections. The method used is the meta-analysis of research outcomes of university (dissertations) and secondary data sources. Data processing is done by meta-analysis of secondary data. The results of meta-analysis research indicate that, the objective conditions, in Indonesia, especially the political conditions, stimulate new spaces in communication research. The study of political communication becomes dominant in the academic environment. In addition, communication research is also characterized by a shift from the linear perspective (positivistic paradigm) to the interactive perspective (naturalistic paradigm). On the other hand, the development of politic and governance situations in Indonesia has prompted the establishment of polling agencies that help citizens understand the maps of political power and candidates in general elections and regional head elections.

• 한국멀티미디어학회논문지
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• 제9권3호
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• pp.360-368
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• 2006

최근 휴대폰의 성능이 향상되면서 다양한 부가기능을 내장한 멀티미디어 폰이 등장했다. 특히 웰빙에 대한 관심이 증가하여 바이오 기능을 휴대폰에 내장 하기위한 다양한 시도가 있어 왔다. 여러 가지 바이오 기능 중 경피 신경 전기치료기는 혈액 순환의 개선과 통증 억제의 기능이 있으므로 이를 휴대폰에 내장시키면 언제 어디서나 쉽게 전기 자극을 통해 혈액 순환을 개선하고 통증 억제를 할 수 있는 장점이 있다. 경피 신경 전기치료기를 휴대폰에 내장시키기 위해서는 소형 및 저전력의 자극모듈이 필요하며, 모듈이 오동작할 경우에도 사용자의 안전을 보장할 수 있어야 한다. 본 논문에서는 소형의 승압기를 이용하여 휴대폰에 내장가능 한 전기자극기를 설계 및 제작하였으며, 사용자의 안전을 위해 자극기의 출력단에 충전된 전체 에너지가 한꺼번에 출력되어도 인체에 무해하도록 설계하였다. 구현한 자극기 모듈의 검증을 위하여 소형의 마이크로 프로세서를 이용하여 테스트 시스템을 구현하여 성능을 검증하였다.

• 대한기계학회논문집B
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• 제30권6호
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• pp.553-559
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• 2006

Most diesel injector, which is currently used in high-pressure common rail fuel injection system of diesel engine, is driven by the solenoid coil energy for its needle movement. The main disadvantage of this solenoid-driven injector is a high power consumption, high power loss through solenoid coil and relatively fixed needle response's problem. In this study, a prototype piezo-driven injector, as a new injector mechanism driven by piezoelectric energy based on the concept of inverse piezo-electric effect, has been designed and fabricated to know the effect of piezo-driven injection processes on the diesel spray structure and internal nozzle flow. Firstly we investigated the spray characteristics in a constant volume chamber pressurized by nitrogen gas using the back diffusion light illumination method for high-speed temporal photography and also analyzed the inside nozzle flow by a fully transient simulation with cavitation model using VOF(volume of fraction) method. The numerical calculation has been performed to simulate the cavitating flow of 3-dimensional real size single hole nozzle along the injection duration. Results were compared between a conventional solenoid-driven injector and piezo-driven injector, both equipped with the same micro-sac multi-hole injection nozzle. The experimental results show that the piezo-driven injector has short injection delay and a faster spray development and produces higher injection velocity than the solenoid-driven injector. And the predicted simulation results with the degree of cavitation's generation inside nozzle for faster needle response In a piezo-driven injector were reflected to spray development in agreement with the experimental spray images.

• Smart Structures and Systems
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• 제6권3호
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• pp.225-238
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• 2010

We report on the development of a new technology for the fabrication of Micro-Electro-Mechanical-System (MEMS) strain sensors to realize a novel type of crackmeter for health monitoring of ageing civil infrastructures. The fabrication of micromachined silicon MEMS sensors based on a Silicon On Insulator (SOI) technology, designed according to a Double Ended Tuning Fork (DETF) geometry is presented, using a novel process which includes a gap narrowing procedure suitable to fabricate sensors with low motional resistance. In order to employ these sensors for crack monitoring, techniques suited for bonding the MEMS sensors on a steel surface ensuring good strain transfer from steel to silicon and a packaging technique for the bonded sensors are proposed, conceived for realizing a low-power crackmeter for ageing infrastructure monitoring. Moreover, the design of a possible crackmeter geometry suited for detection of crack contraction and expansion with a resolution of $10{\mu}m$ and very low power consumption requirements (potentially suitable for wireless operation) is presented. In these sensors, the small crackmeter range for the first field use is related to long-term observation on existing cracks in underground tunnel test sections.