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A study on Fire Hazard of Electric Radiant Heating Systems with Thermal Storage Using Off-peak Electricity (심야용 축열식 전기온풍기의 화재 위험성에 관한 연구)

  • Park, Min-Yeong;Mun, Yong-Su
    • Journal of Korean Institute of Fire Investigation
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    • v.8 no.1
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    • pp.41-48
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    • 2006
  • The purpose of this study is to identify the fire danger of the electric radiant heating system and check the way how to use it and the problems that could be possible through a actual case. We carry out an experiment to identify the possibility of the fire in the similar condition of the actual fire case. The results of this study are as follows. It is a possible condition to fire if the air blast of the electric radiant heating system is blocked by some combustible materials such as plastic bags continuously. A temperature sensor and a residual current device are necessary to disconnect the power source. It is also necessary to attach a notice in front of the electric radiant hearing system that shows users the fire danger to forbid the possible fire. Fires could be happened by internal defects of the electronic products. However, we can also find many external reasons to happen fires. Therefore, we need to check all reasons to make fires in the scene of a fire.

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Electrical Properties of Photovoltaic Cell Using C60 (C60을 이용한 광기전 소자의 전기적 특성 연구)

  • Lee, Ho-Sik;Ahn, Jun-Ho;Lee, Won-Jae;Jang, Kyung-Uk;Choi, Myung-Kyu;Kim, Tae-Wan;Lee, Joon-Ung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.512-513
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    • 2005
  • We have fabricated solar cell devices based on zinc-phthalocyanine(ZnPc) as donor(D) and fullerene(C60) as electron acceptor(A) with doped charge transport layers, and BCP and $Alq_3$ as an exciton blocking layer(EBL). We have measured the photovoltaic characteristics of the solar cell devices using the Xe lamp as a light source. We were use of $Alq_3$ layer leads to external power conversion efficiency was 2.65% at illumination intensity $100mW/cm^2$. Also we confirmed the optimum thickness ratio of the DA hetero-junction is about 1:2.

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Mass-Spring-Damper Model for Offline Handwritten Character Distortion Analysis

  • Cho, Beom-Joon
    • Journal of Korea Multimedia Society
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    • v.14 no.5
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    • pp.642-649
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    • 2011
  • Among the various aspects of offline handwritten character patterns, it is the great variety of writing styles and variations that renders the task of computer recognition very hard. The immense variety of character shape has been recognized but rarely studied during the past decades of numerous research efforts. This paper tries to address the problem of measuring image distortions and handwritten character patterns with respect to reference patterns. This work is based on mass-spring mesh model with the introduction of simulated electric charge as a source of the external force that can aid decoding the shape distortion. Given an input image and a reference image, the charge is defined, and then the relaxation procedure goes to find the optimum configuration of shape or patterns of least potential. The relaxation process is based on the fourth order Runge-Kutta algorithm, well-known for numerical integration. The proposed method of modeling is rigorous mathematically and leads to interesting results. Additional feature of the method is the global affine transformation that helps analyzing distortion and finding a good match by removing a large scale linear disparity between two images.

Performance verification of Smart Complex Damping System for Suppressing Vibration of Stay Cable (케이블 진동 저감을 위한 스마트 복합 감쇠 시스템의 성능평가)

  • Park, Chul-Min;Jung, Hyung-Jo;Ko, Man-Gi;Lee, In-Won
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2006.03a
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    • pp.453-460
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    • 2006
  • Stay cables, such as used in cable-stayed bridges, are prone to vibration due to their low inherent damping characteristics. Recently some studies have shown that active and semiactive control system using MR damper can potentially achieve both higher performance levels than passive control system and adaptability with few of the detractions. However, a control system including a power supply, controller, and sensors is required to maximize the performance of the MR damper and this complicated control system is not effective to most of large civil structures. This paper proposes a smart complex damping system which consists of toggle system and MR dampers by introducing electromagnetic induction(EMI) system as an external power source to MR damper. The performance of the proposed damping device has been compared with that of the passive-type control systems employing a MR damper, a linear viscous damper, and EMI system.

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HST exterior noise : prediction and reduction scheme by using ray tracing technique (고속철도 차량의 외부소음 예측 및 저감 연구 : 광음향기법 응용)

  • Hong, Yun-H.;Kim, Sung-T.;Kim, Jung-Soo
    • Proceedings of the KSR Conference
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    • 2009.05b
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    • pp.209-214
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    • 2009
  • In this research, an external noise distribution of a HST has been analyzed by using a ray tracing techniques. An aero-dynamic noise generated from a bogie has been considered as a major noise source. Then a distribution of the noise on the outside of the vehicle is calculated using a ray noise technique. The models simulated are two different acoustic fields: an open field and a tunnel. In order to evaluate the noise effects, an exterior structure has been modified by using a different length of skirts. Various application schemes of reducing an environmental noise level will be expected for a HST based on this research.

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A Study on Temperature Characteristics according to Ceramic Material Stacking Sequence of Electrostatic Chuck Surface (정전척 표면의 세라믹물질 적층 순서에 따른 온도 특성에 관한 연구)

  • Jang, Kyungmin;kim, Kwangsun
    • Journal of the Semiconductor & Display Technology
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    • v.16 no.3
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    • pp.116-120
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    • 2017
  • Temperature uniformity of a wafer in a semiconductor process is a very important factor that determines the overall yield. Therefore, it is very important to confirm the temperature characteristics of the chuck surface on which the wafer is lifted. The temperature characteristics of the chuck depend on the external heat source, the shape of the cooling channel inside the chuck, the material on the chuck surface, and so on. In this study, CFD confirms the change of temperature characteristics according to the stacking order of ceramic materials on the chuck surface, and suggests the best lamination method.

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A Study on Electrostatic Chuck Cooling by Ceramic Dielectric Material and Coolant path (세라믹 유전체 물질과 냉매 유로 형상에 따른 정전척 냉각에 관한 연구)

  • Kim, Daehyeon;Kim, Kwangsun
    • Journal of the Semiconductor & Display Technology
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    • v.17 no.3
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    • pp.85-89
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    • 2018
  • Temperature uniformity of a wafer in a semiconductor process is a very important factor that determines the overall yield. Therefore, it is very important to confirm the temperature characteristics of the chuck surface on which the wafer is lifted. The temperature characteristics of the chuck depend on the external heat source, the shape of the cooling channel inside the chuck, the material on the chuck surface, and so on. In this study, CFD confirms the change of temperature characteristics according to the stacking order of ceramic materials and inner coolant path on the chuck surface. Finally this study suggests the best cooling condition of electrostatic chuck.

Region-wise evaluation of gamma-ray exposure dose in decontamination operation after a nuclear accident

  • Jeong, Hae Sun;Hwang, Won Tae;Han, Moon Hee;Kim, Eun Han;Lee, Jo Eun;Lee, Cheol Woo
    • Nuclear Engineering and Technology
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    • v.53 no.8
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    • pp.2652-2660
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    • 2021
  • The gamma-ray exposure doses in decontamination operation after a nuclear accident were evaluated with a consideration of various geometrical conditions and specific gamma-ray energies. The calculation domain is organized with three residence types and each form is divided into two kinds of geometrical arrangements. The position-wise air KERMA values were calculated with an assumption of evenly distributed gamma-ray source based on Monte Carlo radiation transport analysis using the MCNP code. The radioactivity is initially set to be unity to be multiplied by the deposition value measured in the actual accident condition. The workforce data set depending on the target object was determined by modifying the Fukushima report. The external exposure doses for decontamination workers were derived from the calculated KERMA values and the workforce analysis. These results can be used to efficiently determine the workforce required by the characteristics of the area and the structure to be decontaminated within the dose limits.

Recent Progress in Passive Radiative Cooling for Sustainable Energy Source

  • Park, Choyeon;Park, Chanil;Choi, Jae-Hak;Yoo, Youngjae
    • Elastomers and Composites
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    • v.57 no.2
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    • pp.62-72
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    • 2022
  • Passive daytime radiative cooling (PDRC) is attracting increasing attention as an eco-friendly technology that can save cooling energy by not requiring an external power supply. An ideal PDRC structure should improve solar reflectance and emissivity within the atmospheric spectral window. Early designs of photonic crystal materials demonstrated the benefits of PDRC. Since then, functional arrangements of polymer-based radiative cooling materials have played an important role and are rapidly expanding. This review summarizes the known inorganic, organic, and hybrid materials for PDRC. The review also provides a complete understanding of PDRC and highlights its practical applications.

Integration of Technology Acceptance Model (TAM), Marketing Relationships, and Sharia Compliance in Indonesia's Islamic e-banking

  • USMAN, Hardius;PROJO, Nucke Widowati Kusumo
    • Asian Journal of Business Environment
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    • v.12 no.4
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    • pp.25-34
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    • 2022
  • Purpose This research develops the expanded Technology Acceptance Model (TAM) to investigate the relationship between perceived usefulness and perceived ease of use with satisfaction and loyalty by considering the role of sharia compliance, commitment, and trust. Research design, data and methodology: A data source is 300 respondents from a self-administered survey. The target population is Muslims who are customers of Islamic banks, with age at least 18 years, and used e-banking to make payment transactions. The analysis methods are MANOVA and Multiple Linear Regression. Results: The results suggest that intention to use and actual behavior variables are replaced with satisfaction and loyalty. Commitment is not recommended, while trust is an explanatory variable that can be used as an external variable. Conclusions: It is important to increase satisfaction and commitment also concentrate to various aspects of sharia compliance to increase customer's loyalty to use e-banking. The fulfillment of sharia compliance by Islamic banks will increase the Islamic bank customers loyalty.