• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.155-158
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• 1999

Because the traditional filters have many demerits, multi-step electric oil filter have manufactured the efficiency of insulating oil to improve. Therefore, the function of oil filter to improve based on my experience and know-how about my job. Through this study have obtained many merits. The efficiency of insulating oil is improved. The waste oil reused in repair works of the damaged transformer. Multi-step filter is shortening the working time and safety. it is handy for use and movement. This study lengthen the expected life span of filter. The improvement of oil filter bring about elevation of productivity.

• 한국해안해양공학회지
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• 제6권4호
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• pp.459-471
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• 1994

쇄파작용에 기인한 준 3차원적 연안류 순환 모델의 수치 기법을 제시한다. 지배 방정식은 근사 factorization 기법과 fractional step method를 사용하여 음해법으로 수치해석 되었고 분할된 식은 유한 체적법으로 차분된다. 계산된 3차원적 연안류 패턴의 한 예로서 Gourlay(1974)의 실험자료와 비교하여 간접적으로 모델의 타당성을 검증한다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.184-185
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• 2006

Two-step growth to incorporate the Mg atoms in the ZnO nanorods fabricate by thermal evaporation process and also utilized the ZnO film as a template. In the first step of low temperature, Zn seed metals with low melting temperature formed the droplet, and then MgZnO ternary nanorods were grown by injecting oxygen and evaporating Mg atoms in high temperature process of the second step. The vertical growth of the MgZnO nanorods with large-area distribution and uniformity was successfully performed on the ZnO template. We investigated the shape of the vertically grown 1-D MgZnO nanorods and characterized the optical and crystal properties. We confirmed the incorporation of Mg atoms by the EDS and PL spectrum.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.265.1-265.1
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• 2013

Nanoporous anodic aluminum oxide (AAO), a self-ordered hexagonal array has various applications for nanofabrication such as nanotemplate, and nanostructure. In order to obtain highly-ordered porous alumina membranes, Masuda et al. proposed a two-step anodization process however this process is confined to small domain size and long hours. Recently, alternative methods overcoming limitations of two-step process were used to make prepatterned Al surface. In this work, we confirmed that there is a specific tendency used a PDMS stamp to obtain a pre-patterned Al surface. Using the nanoindentaions of a PDMS stamp as chemical carrier for wet etching, we can easily get ordered nanoporous template without two-step process. This chemical etching method using a PDMS stamp is very simple, fast and inexpensive. We use two types of PDMS stamps that have different intervals (800nm, 1200nm) and change some parameters have influenced the patterning of being anodized, applied voltage, soaking and stamping time. Through these factors, we demonstrated the patterning effect of large scale PDMS stamp.

• 소성∙가공
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• 제5권2호
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• pp.130-137
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• 1996

The sheet formability can be improved by the optimum drawbeads installation because draw-beads can control the flow of the metal into the die cavity when the punch enters into the die opening, In this study the drawing characteristics for step drawbead are analyzed by 2-D rigid -plastic FEM and also are measured experimentally. In addition for the validity of FEM theoretical results are compared with the experimental results. Especially the draw bead restrain-ing forces and the strain distributions of drawn specimens are obtained in both FEM and experiment. Also the effects of the drawbead dimensions drawing angles and blank holding forces on the drawing characteristics are investigated.

• 한국관개배수논문집
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• 제13권1호
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• pp.50-62
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• 2006

In order to improve areas lagged behind well-developed others ing the balanced national development. Development Promotion Areas(DPA)was designated in 1996. This study aims to develop a rational evaluation system for projects of DPA. This system has 3 evaluation steps. The first step is to evaluate 10-unit operations which are tourism, recreation, road, water supply and drainage, life environment, and so on. The second step is to evaluate 3 sub-programs such as tourism and recreation, local infrastructures and specialized industry. The third step is to evaluate comprehensively in entire area. A tentative system for project evaluation of DPA was proposed by brainstorming of expert-group. Weighting values of items in PDA were calculated through pair-comparison works of expert group using stepwise matrix sheets by AHP(Analytic Hierarchy Process).

• Journal of Power Electronics
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• 제17권6호
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• pp.1402-1412
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• 2017

This paper presents a new high step-up dc/dc converter for renewable energy systems in which a high voltage gain is provided by using a coupled inductor. The operation of the proposed converter is based on a charging capacitor with a single power switch in its structure. A passive clamp circuit composed of capacitors and diodes is employed in the proposed converter for lowering the voltage stress on the power switch as well as increasing the voltage gain of the converter. Since the voltage stress is low in the provided topology, a switch with a small ON-state resistance can be used. As a result, the losses are decreased and the efficiency is increased. The operating principle and steady-states analyses are discussed in detail. To confirm the viability and accurate performance of the proposed high step-up dc-dc converter, several simulation and experimental results obtained through PSCAD/EMTDC software and a built prototype are provided.

• Journal of Information Processing Systems
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• 제18권2호
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• pp.173-187
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• 2022

A special government agency has been charged with implementing quality management to guarantee the quality of wild-simulated ginseng. However, these processes are carried out by use of documents, and this has resulted in information omission and high document management costs. To solve this problem, this study analyzed the existing quality management process by using a smart contract for the existing offline form and proposed a new quality management system for storing and managing all log data in the blockchain. This system reduced documentation management costs about quality management and recorded information in the previous step through the quality management steps, thus forming a step-by-step record chain. Experiments were conducted by implementing this system, which improved data integrity and reliability. Additionally, sensitive information, such as personal information, was included in the system by use of the off-chain technology.

• 센서학회지
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• 제30권4호
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• pp.218-222
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• 2021

Wearable multi-sensors based on nanocrystals have attracted significant attention, and studies on patterning technology to implement such multi-sensors are underway. Conventional patterning processes may affect material properties based on high temperatures and harsh chemical conditions. In this study, we developed an inkjet printing technique that can overcome these drawbacks through the application of patterning processes at room temperature and atmospheric pressure. Nanocrystal-based ink is used to adjust properties efficiently. Additionally, the viscosity and surface tension of the solvents are investigated and optimized to increase patterning performance. In the patterning process, the electrical, electrothermal, and electromechanical properties of the nanocrystal pattern are controlled by the ligand exchange process. Experimental results demonstrate that a multi-sensor with a temperature coefficient of resistance of 3.82 × 10^-3 K^-1 and gauge factor of 30.6 can be successfully fabricated using one-step inkjet printing.

• 복식문화연구
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• 제21권3호
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• pp.376-393
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• 2013

In modern society, culture is an important factor to form a country's image and identity and a representative content to generate revenue. Culture is a keyword to design life in the 21st century and has become competitiveness between countries. As a cultural content with international competitiveness, this study performed textile design development with the use of relics from the Tomb of King Muryeong, which is the tumulus of King Muryeong who was the 25th king of Baekje among Korean history. The developed design could be applied to the production of various fashion cultural products such as clothes, scarf, neck-tie, and bag. The process for the design development was carried out as follows: As a first step, this study found basis as a cultural content with a global sense that could form the historical value of the Tomb of King Muryeong and gain global sympathy of people all over the world through literature reviews. As a second step, this study examined the current state that traditional Korean elements were used as a fashion cultural products. As a third step, this study analyzed the current state and problems of fashion cultural products using relics from the Tomb of King Muryeong through field survey. As a final step, this study planned the concept of design with the use of diadem ornaments, earring, sword, stone guardian animal, and bricks with lotus-flower design from the tomb of King Muryeong. And these developed 6 textile designs could be applied to the production of various fashion cultural products.