• Title/Summary/Keyword: Board Structure

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Development and rotating test of the high temperature superconducting motor with on-board cryocooler (탑재형 냉동기를 이용한 고온 초전도 모터 개발 및 회전 실험)

  • Ki, Tae-Kyung;Kim, Young-Kwon;Kim, Hee-Sun;Jeong, Sang-Kwon
    • Progress in Superconductivity and Cryogenics
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    • v.13 no.1
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    • pp.12-16
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    • 2011
  • In this paper, the prototype of the HTS motor with an on-board cryocooler, is fabricated and tested. The overall system is composed of the stator with conventional copper winding, the rotor with superconductor, and the rotating cryocooler designed from the on-board concept. The rotor is fabricated as the race-track coil with 2G, YBCO tape and contacts with the on-board cryocooler while being rotated together. An inline-type pulse tube refrigerator is used as the on-board cryocooler. The cryocooler is fabricated from optimal process to satisfy the structure and thermal stability of the on-board system. Each component is integrated according to carefully defined sequence. Specially, a combining method of torque tubes is an important part for sustaining stability of the rotor and the cryocooler. In the rotating test, the HTS motor is successfully operated with 240 rpm of rotating speed when 75 A current is supplied to the superconducting rotor. In this paper, potential problems of the HTS motor system using the on-board cryocooler are proposed and solved, and realistic possibility of this concept is also confirmed.

Analysis of the Types of External Wall and Roof Structure Layer Composition of CLT Building (CLT 건축물의 외벽 및 지붕 구조체 레이어 구성 유형 분석)

  • Yoo, Dong-Wan;Lee, Tae-Goo
    • Journal of the Korean Institute of Rural Architecture
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    • v.22 no.4
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    • pp.71-78
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    • 2020
  • Today, the whole world is going through a big chaos due to the COVID-19, but paradoxically, the emergence of COVID-19 has been leading to the need for sustainable development, such as Green New Deal that can improve global warming and carbon emissions, and the need for sustainable architecture is growing bigger and bigger in the architectural field as well. The level of CLT buildings in Korea is at a very rudimentary stage, while CLT buildings remedying existing wooden buildings are getting the spotlight among European countries for sustainable architecture. This study was conducted to categorize structure layer compositions of overseas CLT buildings and analyze architectural techniques and materials applied by collecting and analyzing information about CLT structure layer compositions of overseas CLT building-related institutions, companies and cases. When classifying structure layer compositions of foreign CLT buildings depending on the roles of layers. it was revealed that exterior wall structure layers were combined and organized within a sequence of external finishing, ventilation, waterproof, board, external insulation, airtightness, structure, airtightness, interior insulation, interior finishing, sloped roof structure layers were external finishing, ventilation, waterproof, board, external insulation, airtightness, structure, airtightness, interior insulation, interior finishing, flat roof structure layers were external finishing, ventilation, waterproof, planking wood, external insulation, waterproof, external insulation, airtightness, structure, airtightness, interior insulation, interior finishing.

A Reduced Component count Single-stage Electrolytic Capacitor-less Interleaved Totem-pole On-board Battery Charger (적은 소자수를 갖고 전해커패시터가 없는 단일단 인터리브드 토템폴 전기자동차 탑재형 충전기)

  • Kim, Byeong-Woo;Cho, Woo-Sik;Choi, Se-Wan
    • The Transactions of the Korean Institute of Power Electronics
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    • v.22 no.6
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    • pp.510-516
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    • 2017
  • This paper proposes a single-stage interleaved totem-pole on-board battery charger with a simple structure and a reduced component count. Apart from achieving ZVS turn-on of all switches and ZCS turn-off of all diodes, this charger does not require an input filter due to its CCM operation and bulky electrolytic capacitors, which in turn result in a high power density. A single-stage power conversion technique is applied to the interleaved structure in order to achieve a high power density and high efficiency. A 2.5 kW prototype of the proposed charger is also built and tested to validate the proposed operation.

Legal Study on Corporate Governance in China (중국법에 의한 기업지배구조에 관한 연구)

  • Kim, Jung-Ihl
    • The Journal of the Korea Contents Association
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    • v.6 no.11
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    • pp.8-14
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    • 2006
  • With an analysis of government owned corporations based on Chinese law as a subject and in the light of comparing and assessing intra-company domination called internal management organization with the domination structure of already established advanced nations, the objective of this study is to analyze the reality and possibility of company domination structure of Chinese government owned corporations. Especially, the intra-company domination structure in China from the points of view such as general meeting of stock holders, director and board of directors, and board of auditors, this study examines the direction toward which internal domination organizations in China form. Also, related to chinese corporations, the study proposes the model in which the possession right of general meeting of stock holders, corporation property right of board of directors, corporation representative right of the senior executive and superintendency of board of auditors are mutually restricted and inter-connected.

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Development of Build-up Printed Circuit Board Manufacturing Process Using Rapid Prototyping Technology and Screen Printing Technology (쾌속조형과 스크린 인쇄기술을 이용한 빌드업인쇄회로기판의 제조공정기술개발)

  • 조병희;정해도;정해원
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.2
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    • pp.130-136
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    • 2000
  • Generally, the build-up printed circuit board manufactured by the sequential process with etching, plating, drilling etc. requires many types of equipments and lead time. Etching process is suitable for mass production, however, it is not adequate for manufacturing prototype in the developing stage. In this study, we introduce a screen printing technology to prototyping a build-up printed circuit board. As for the material, photo/thermal curable resin and conductive paste are used for the formation of dielectric and conductor. The build-up structure is made by subsequent processes such as the formation of liquid resin thin layer, the solidification by UV/IR light, and via filling with conductive paste. By use of photo curable resin, productivity is greatly enhanced compared with thermal curable resin. Finally, the basic concept and the possibility of build-up printed circuit board prototyping are proposed in comparison with to the conventional process.

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Board Gender Diversity and Corporate Sustainability Performance: Mediating Role of Enterprise Risk Management

  • FAKIR, A.N.M. Asaduzzaman;JUSOH, Ruzita
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.6
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    • pp.351-363
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    • 2020
  • The objective of this paper is to explore how board gender diversity affects corporate sustainability performance. Therefore, this paper examines the direct association between board gender diversity with corporate sustainability performance and the mediation effect of enterprise risk management (ERM) on this association. The study employed a cross-sectional survey method. Data were collected from annual reports, websites, and through the questionnaires that were distributed to Chief Financial Officers (CFOs) of all the listed companies of Dhaka Stock Exchange, Bangladesh. The partial least square technique of Structural Equation Modelling (SEM) approach was employed for data analysis. The result did not find support for the direct association between board gender diversity and sustainability performance in Bangladesh context. This implies that contextual factors, such as, male-dominant board, appointment of female directors based on family ties, lack of education and expertise etc. may discount gender diversity direct influence on sustainability performance. However, the study finds strong support for the mediating role of ERM use within the corporate structure. Further analysis of indirect effect suggests that ERM use mediates the relationship of board gender diversity and sustainability performance in full. This implies that in the Bangladesh context effective use of ERM is highly recommended.

Development of Electronic White-board Based on Embedded Linux (임베디드 리눅스 기반의 전자 칠판 시스템 개발)

  • Seo, Chang-Jun
    • IEMEK Journal of Embedded Systems and Applications
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    • v.2 no.4
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    • pp.214-220
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    • 2007
  • Recently, most embedded systems have the multi-functions mixed the hardware with the software. The existing sequence programming methods are not suitable to implement the embedded system with multi-functions. So, it can be overcome the limit of a facility implementation by introducing the operating system in system. Also, due to the requirement about the better convenient and comfortable meeting or lecture environment, the necessity of electronic white-board is getting higher. Specially, the education using multimedia information is much more desirable for various and improved lecture at the high school and the university. But the sequence program which have been managed in existing electronic white-board system has some difficulties to achieve the software-oriented systems which has to accomplish many functions. In this paper, we propose the method to implement a facility of electronic white-board through using the embedded linux with excellent performance. The embedded linux presents the powerful software environment for the implementation of an embedded system and makes the realization of many various functions easy because it follows kernel characteristics of linux. In this paper, we describe the details for the structure of hardware, kernel source and device driver of a developed electronic white-board.

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Finite Element Analysis of a Ventilating Box Structure (통기성 상자 구조물에 대한 유한요소 해석)

  • 박종민;권순구
    • Journal of Biosystems Engineering
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    • v.27 no.6
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    • pp.557-564
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    • 2002
  • Corrugated board is an efficient low-cost structure material fur the boxes that are widely used for transporting, storing and distributing goods. Corrugated board is also considered as an orthotropic because the principal material directions are the same as in paperboard. The purpose of this study was to elucidate the principal design parameters of ventilating box through the FEA on the various types of ventilating hole. From the viewpoint of the stress distribution and stress level, the optimum pattern and location of the ventilating hole were vertically oblong, and symmetry position with a short distance to the right and left from the center of front and rear panel. And, the optimum location and pattern of hand hole were a short distance to the top from the center of both side panels, and modified shape to increase the radius of curvature of both side in horizontal oblong. In general, the optimum pattern and location of both the ventilating hole and hand hole based on the FEM analysis were well verified by experimental investigation. It is suggested that decrease in compressive strength of the box could be minimized in the same ventilating hole area under the condition of the length of major axis of ventilating hole is less than 1/4 of box length, the ratio of minor axis/major axis is 113.5∼l/2.5, and number of the ventilating holes is even and symmetrical.

Corporate Governance and Capital Structure Decisions: Evidence from Chinese Listed Companies

  • VIJAYAKUMARAN, Sunitha;VIJAYAKUMARAN, Ratnam
    • The Journal of Asian Finance, Economics and Business
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    • v.6 no.3
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    • pp.67-79
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    • 2019
  • This study examines the impact of corporate governance on capital structure decisions based on a large panel of Chinese listed firms. Using the system Generalized Method of Moments (GMM) estimator to control for unobserved heterogeneity, endogeneity, and persistency in capital structure decisions, we document that the ownership structure plays a significant role in determining leverage ratios. More specially, we find that managerial ownership has a positive and significant impact on firms' leverage, consistent with the incentive alignment hypothesis. We also find that managerial ownership only affects the leverage decisions of private firms in the post-2005 split share reform period. State ownership negatively influence leverage decisions implying that SOEs may face fewer restrictions in equity issuance and may receive favourable treatments when applying for seasoned equity ¿nancing, thus use less debt. Furthermore, our results show that while foreign ownership negatively influences leverage decisions, legal person shareholding positively influences firms' leverage decisions only for state controlled firms. We also find that the board structure variables (board size and the proportion of independent directors) do not influence firms' capital structure decisions. Our findings suggest that recent ownership reforms have been successful in terms of providing incentive to managers through managerial shareholdings to take risky financial choices.

A Case study on Effect of Compositeness for Temporary Bridge Integrated Lining Board and Girder (복공판과 주형을 일체화한 가설교량에 대한 합성효과 검토 사례연구)

  • Yoon, Woo-Hyun;Chung, Jee-Seung;Lee, Jong-Soon;Yoon, Yong-Seok;Yang, Sung-Don
    • Journal of the Korean Society of Safety
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    • v.27 no.2
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    • pp.34-41
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    • 2012
  • In this study, it has been proposed the new type of temporary bridge which is structural performance maximization to integrated cover plate and girder as well as roll of lining board. Of all temporary bridge integrated cover plate and main girder in the form of a new type of structure is advantageous for the judge, but to the field of transport difficulties and challenges due to high altitude operations to take advantage of this challenge and deliver a structured, easy transport, and the synthesis of lining board possible was proposed. Lining board proposed in this study through experimental synthesis and analysis of the factors that influence the effectiveness of the construction and economic development in the construction method was superior, compared to the conventional lining board.