• Title/Summary/Keyword: Hwang-to

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광경화성 단분자를 이용한 pattern free vertical alignment 모드의 전기 광학 특성 연구 (Study on electro optic characteristic of pattern free vertical alignment (PFVA) mode using the uv curable reactive mesogen (RM))

  • 조인영;황성진;김성민;황지혜;이승희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 춘계학술대회 및 기술 세미나 논문집 디스플레이 광소자
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    • pp.45-46
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    • 2008
  • The conventional biased vertical alignment (BVA) mode has several advantages such as rubbing- and protrusion-free, wide-viewing angle and stable LC dynamics against external pressure. However manufacturing process of BVA mode is difficult task because the pixel and bias electrode signal are different in each frame. To solve this problem, we investigated the pattern free vertical alignment (PFVA) by using the UV-curable reactive mesogen (RM), in which the LC molecules were made to be pre-tilted. Eventually transmittance and response time in PFVA mode were found to be improved as compared to BVA mode.

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Dynamic Clustering for Load-Balancing Routing In Wireless Mesh Network

  • Thai, Pham Ngoc;Hwang, Min-Tae;Hwang, Won-Joo
    • 한국멀티미디어학회논문지
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    • 제10권12호
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    • pp.1645-1654
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    • 2007
  • In this paper, we study the problem of load balancing routing in clustered-based wireless mesh network in order to enhance the overall network throughput. We first address the problems of cluster allocation in wireless mesh network to achieve load-balancing state. Due to the complexity of the problem, we proposed a simplified algorithm using gradient load-balancing model. This method searches for a localized optimal solution of cluster allocation instead of solving the optimal solution for overall network. To support for load-balancing algorithm and reduce complexity of topology control, we also introduce limited broadcasting between two clusters. This mechanism maintain shortest path between two nodes in adjacent clusters while minimizing the topology broadcasting complexity. The simulation experiments demonstrate that our proposed model achieve performance improvement in terms of network throughput in comparison with other clustering methods.

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비소성 황토의 치환율에 따른 콘크리트의 유동특성 및 강도특성에 관한 실험적 연구 (An Experimental Sutdy on the Fluidity and Strength Properties of Concrete According to the Replacement ratio of Non Firing Hwang-toh)

  • 이종성;이승민;이지환;이상수;송하영
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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    • pp.375-376
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    • 2009
  • 본 연구는 현재 시행중인 교토의정서 발효로 인하여 시멘트 제조시 발생되는 CO$_2$의 발생량을 감소시키기 위해 대체재로 전통건축재료인 비소성 황토를 치환한 콘크리트의 기초자료를 제시하는데 목적을 두었다.

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도시철도용 표준화 대차프레임의 강도평가 (Strength Assessment of Standardized Bogie Frame for Urban EMU)

  • 황동황;최중호;송시엽
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2005년도 춘계학술대회 논문집
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    • pp.447-452
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    • 2005
  • Nowadays domestic demands for urban EMUs are gradually increased due to traffic jams and environmental problems. Therefore it has been required to make sure of manufacturing quality and to acquire cost effective bogie frames through mass production. One of the major functions of bogie frames is to guarantee the static strength and durability. In this research, the comparison between FE analysis and actual load test results is performed for the bogie frame, which is manufactured by Rotem Company. The results show that the standardized bogie frame meets the strength requirements of domestic regulations.

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송전선로 DC화에 따른 융통조류 마진 분석 (Analysis of system power flow margin on replacement of transmission line to DC line)

  • 황성철;이재형;황평익;윤민한;장길수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2015년도 제46회 하계학술대회
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    • pp.420-421
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    • 2015
  • Recently construction of new transmission line is getting harder because of social hostility to transmission tower. Howevere, load is converged in metropolitan area and power plants near this area are old and life of generator will end soon. Therefore, power to supply load in this area should be transmitted from east coast area and southern area. For these reasons, securement of transmission capacity without new transmission line construction is important. In this paper, effect of one circuit AC line change to DC transmission at the same transmission tower on the system available transfer capacity is analyzed.

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연삭가공에서 절삭유 에어로졸 측정평가에 관한 연구 (A Study on the Analysis of Cutting Fluid Aerosol in Grinding Process)

  • 황준;황덕철;우창기;정의식
    • 한국공작기계학회논문집
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    • 제14권5호
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    • pp.1-6
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    • 2005
  • Machining is a one of the broadly used manufacturing process to produce the parts, products and various molds and dies. The environmental impact due to aerosol generation via atomization process is a major concern associated with environmental consciousness. This paper presents the experimental results to analyze the characteristics of cutting fluid aerosol generation in grinding process. Experimental results show that the generated fine aerosol which particle size less than 10micron appears near worker's breath zone under given operational conditions. The aerosol concentration is much higher enough to affect human health risk with its generated aerosol quantities. This quantitative analysis can be provided the basic knowledge f3r further research for environmentally conscious machining technology developments.

Isolation and characterization of the rice NPR1 promoter

  • Hwang, Seon-Hee;Hwang, Duk-Ju
    • Plant Biotechnology Reports
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    • 제4권1호
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    • pp.29-35
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    • 2010
  • NPR1 is a positive regulator of systemic acquired resistance in Arabidopsis and rice. Expression of the rice gene OsNPR1 is induced by salicylic acid (SA). To identify the region of the OsNPR1 promoter involved in response to SA, we carried out deletion mutagenesis of the region 1005 bp upstream of the OsNPR1 start codon. Ciselement analysis revealed that the OsNPR1 promoter contains W-boxes and ASF1 motifs, both of which are known to be functional cis-elements of the WRKY and bZIP proteins, respectively. The deletion constructs 1005:LUC and 752:LUC, were induced by up to 4.3- and 3.8-fold, respectively, following SA treatment, suggesting that W-boxes and ASF1 motifs may play an important role in the strong induction of these constructs by SA. Using mutation analysis, we also showed that both the W-box and ASF1 motif are necessary for SA-induced expression of OsNPR1.

재무 가치를 고려한 PMO의 전략적 동일 한정 자원 배분 (Strategic Allocation of the Limited Same Resource by Program Management Office Considering Financial Values)

  • 황진하;김주한;황지연
    • 산업경영시스템학회지
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    • 제35권3호
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    • pp.24-31
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    • 2012
  • Priority rules or sequencing heuristics conventionally used to determine resource allocation is to maximize the earned value on time and cost. This study provides a effective strategy-oriented approach for the program resource management problem with limited same resource, which systematically connects individual project objectives to the overall organizational goal, by introducing financial values as well as priority rules in a broader context. It deals with the resource allocation problem as the decision making problem in the strategic management paradigm to meet business objective and solves it using the analytic hierarchy process, and explains the method of application and usefulness through some simulation cases.

복합재료 사이클로콥터 로터 블레이드의 구조 설계 및 해석 (Structural Design and Analysis of Composite Cyclocopter Rotor Blades)

  • 황인성;황창섭;윤철용;김승조
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2004년도 춘계학술발표대회 논문집
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    • pp.91-94
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    • 2004
  • A cyclocopter with the cycloidal blades system can be the type of UAV which can combine the high-speed characteristics of the conventional airplane with the low-speed characteristics of the helicopter. The cycloidal blades system, which can be described as a horizontal rotary wing, offers powerful thrust levels, and a unique ability to change the direction of the thrust almost instantly. Rotor blades are designed to withstand tremendous transverse centrifugal loadings, and responding to a number of aerodynamic harmonic vibratory forcing frequencies. To reduce the weight and increase the strength, the blades are made of composite materials. The blades consist of the skin, spar, and trailing stiffener. In this study, static and dynamic behaviors of cyclocopter rotor blades are analyzed by using MSC/NASTRAN.

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연삭가공에서 절삭유 에어로졸 측정평가에 관한 연구 (A Study on the Analysis of Cutting Fluid Aerosol in Grinding Process)

  • 황준;황덕철;우창기;정의식
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2005년도 춘계학술대회 논문집
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    • pp.282-287
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    • 2005
  • This paper presents the experimental results to analyze the characteristics of cutting fluid aerosol generation in grinding process. Machining is a one of the broad manufacturing process to produce the parts, products and various molds and dies. The environmental impact due to aerosol generation via atomization process is a major concern associated with environmental consciousness. Experimental results show that the generated fine aerosol which particle size less than 10 micron appears near worker's breath zone under given operational conditions. The aerosol concentration is much higher enough to affect human health risk with its generated aerosol quantities. This qualitative analysis can be provided the basic knowledge for further research for environmentally conscious machining technology developments.

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