• Title/Summary/Keyword: External Diffusion

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A Study on the Identification Technique and Prevention of Combustion Diffusion through ESS (Energy Storage System) Battery Fire Case (ESS (에너지 저장장치) 배터리 화재사례를 통한 감식기법 및 연소 확산방지에 관한 연구)

  • Lee, Jung-Il
    • Journal of the Society of Disaster Information
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    • v.16 no.2
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    • pp.383-391
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    • 2020
  • Purpose: To identify internal self ignition and ignition caused by external flames in energy storage rooms, and to analyze the difference between ignition due to overheating and ignition caused by external heat sources. Method: membrane melting point measurement, battery external hydrothermal experiment, battery overcharge experiment, comparative analysis of electrode plate during combustion by overcharge and external heat, overcharge combustion characteristics, external hydrothermal fire combustion characteristics, 3.4 (electrode plate comparison) / 3.5 (overcharge) /3.6 (external sequence) analysis experiment. Result: Since the temperature difference was very different depending on the position of the sensor until the fire occurred, it is judged that two temperature sensors per module are not enough to prevent the fire through temperature control in advance. Conclusion: The short circuit acts as an ignition source and ignites the mixed gas, causing a gas explosion. The electrode breaks finely due to the explosion pressure, and the powder-like lithium oxide is sparked like a firecracker by the flame reaction.

Single chip multi-function peripheral image processor with unified binarization architecture (통합된 이진화 구조를 가진 복합기용 1-Chip 영상처리 프로세서의 개발)

  • Park, Chang-Dae;Lee, Eul-Hwan;Kim, Jae-Ho
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.36S no.11
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    • pp.34-43
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    • 1999
  • A high-speed image processor (HIP) is implemented for a high-speed multi-function peripheral. HIP has a binarization architecture with unified data path. It has the pixel-by-pixel pipelined processing to minimize size of the external memory. It performs pre-processing such as shading correction, automatic gain control (AGC), and gamma correction, and also drives external CCD or CIS modules. The pre-processed data can be enlarged or reduced. Various binarizatin algorithms can be processed in the unified archiecture. The embedded binarization algorithms are simple thresholding, high pass filtering, dithering, error diffusion, and thershold modulated error diffusion. These binarization algorithms are unified based on th threshold modulated error diffusion. The data path is designed to share the common functional block of the binarization algorithms. The complexity of the controls and the gate counts is greatly reduced with this novel architecture.

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Optically Controlled Silicon MESFET Fabrication and Characterizations for Optical Modulator/Demodulator

  • Chattopadhyay, S.N.;Overton, C.B.;Vetter, S.;Azadeh, M.;Olson, B.H.;Naga, N. El
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.10 no.3
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    • pp.213-224
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    • 2010
  • An optically controlled silicon MESFET (OPFET) was fabricated by diffusion process to enhance the quantum efficiency, which is the most important optoelectronic device performance usually affected by ion implantation process due to large number of process induced defects. The desired impurity distribution profile and the junction depth were obtained solely with diffusion, and etching processes monitored by atomic force microscope, spreading resistance profiling and C-V measurements. With this approach fabrication induced defects are reduced, leading to significantly improved performance. The fabricated OPFET devices showed proper I-V characteristics with desired pinch-off voltage and threshold voltage for normally-on devices. The peak photoresponsivity was obtained at 620 nm wavelength and the extracted external quantum efficiency from the photoresponse plot was found to be approximately 87.9%. This result is evidence of enhancement of device quantum efficiency fabricated by the diffusion process. It also supports the fact that the diffusion process is an extremely suitable process for fabrication of high performance optoelectronic devices. The maximum gain of OPFET at optical modulated signal was obtained at the frequency of 1 MHz with rise time and fall time approximately of 480 nS. The extracted transconductance shows the possible potential of device speed performance improvements for shorter gate length. The results support the use of a diffusion process for fabrication of high performance optoelectronic devices.

A Study on Forecast of Penetration Amount of High-Efficiency Appliance Using Diffusion Models (확산 모형을 이용한 고효율기기의 보급량 예측에 관한 연구)

  • Park, Jong-Jin;So, Chol-Ho;Kim, Jin-O
    • Journal of Energy Engineering
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    • v.17 no.1
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    • pp.31-37
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    • 2008
  • At present, the target amount of demand-side management and investment cost of EE (Energy Efficiency) program, which consists of high-efficiency appliances, has been estimated simply by the diffusion function based on the real historical data in the past or last year. In the internal and external condition, the penetration amount of each appliance has been estimated by Bass diffusion model which is expressed by time and three coefficients. And enough acquisition of real historical data is necessary for reasonable estimation of coefficients. In energy efficiency, to estimate the target amount of demand-side management, the penetration amount of each appliance should be primarily forecasted by Bass diffusion model in Korea. On going programs, however, lightings, inverters, vending machine and motors have a insufficient real historical data which is a essential condition to forecast the penetration amount using a Bass diffusion model due to the short period of program progress. In other words, the forecast of penetration amount may not be exact, so that it is necessary for the method of forecast to apply improvement of method. In this paper, the penetration amount of high-efficiency appliances is forecasted by Bass, virtual Bass, Logistic and Lawrence & Lawton diffusion models to analyze the diffusion progress. And also, by statistic standards, each penetration is compared with historical data for model suitability by characteristic of each appliance. Based on the these result, in the forecast of penetration amount by diffusion model, the reason for error occurrence caused by simple application of diffusion model and preferences of each diffusion model far a characteristic of data are analyzed.

An Analysis Acceptance Factors for the Early Diffusion of Mulberry Protected Cultivation (오디 시설재배 조기 확산을 위한 수용요인분석)

  • Kim, Woong;Lee, Ki Kwon;Yu, Young Seok;Choi, Don Woo
    • Journal of Agricultural Extension & Community Development
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    • v.21 no.2
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    • pp.29-56
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    • 2014
  • This study conduct for 200 farmhouses who didn't accept new technology like mulberry Protected Cultivation. Through research model combined Innovation diffusion theory(IDT) and Technology Acceptance Model(TAM), it analysed which factors affect for new technology acceptance and diffusion. To verify relations between external factors which affect new technology acceptance and diffusion by endogenous variables such as perceived usefulness, perceived ease of use and perceived riskiness, with external factors, mothed used to analyse it. Most of adopted variables were showed positive results except for individual innovativeness and reliability. Based on the results of these analyses, we can suggest rapid. First, technique diffusion agents should have heighten the level of expertise and technology, and build up the network to solve difficulties with technique supply with mulberry farmhouses. Secondly farmhouses of mulberry outdoor cultivation showed positive attitude protected cultivation, but negative attitude it bacause of the burden of facilities investment. Thus, it is needed to capital investment for individual farmhouse hold. Finally, through cultivation technology education, field trip about mulberry protected cultivation, we can diffuse technology receive for negative farmers.

The Microstructures and Properties of Surface Layer on the Tool Steel Formed by Ion Nitriding -Effects of Process Parameter- (마이크로 펄스 플라즈마 질화에 의해 생성된 금형 공구강의 표면층에 관한 연구 -공정 변수의 영향-)

  • Lee, J.S.;Kim, H.G.;You, Y.Z.
    • Journal of the Korean Society for Heat Treatment
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    • v.14 no.1
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    • pp.8-16
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    • 2001
  • The effects of gas composition, pressure, temperature and time on the case thickness, hardness and nitride formation in the surface of tool steels(STD11 and STD61) have been studied by micro-pulse plasma nitriding. External compound layer and internal diffusion layer and the diffusion layer were observed in the nitrided case of tool steels. The relative amounts and kind of phases formed in the nitrided case changed with the change of nitriding conditions. Generally, only nitride phases such as ${\gamma}(Fe_4N)$, ${\varepsilon}(Fe_{2-3}N)$, or $Cr_{1.75}V_{0.25}N_2$ phases were detected in the compound layer, while nitride and carbide phases such as ${\varepsilon}-nitride(Fe_{2-3}N)$, $(Cr,Fe)_{\gamma}C_3$ or $Fe_3C$ were detected in the diffusion layer by XRD analysis. The thickness of compound layer increased with the increase of nitrogen content in the gas composition. Maximum case depth was obtained at gas pressure of 200Pa.

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Experimental Study on Carbon Corrosion of Gas Diffusion Layer in PEM Fuel Cell (고분자전해질형 연료전지 가스확산층의 탄소 부식에 관한 실험적 분석)

  • Ha, Taehun;Cho, Junhyun;Park, Jaeman;Min, Kyoungdoug;Lee, Eunsook;Jyoung, Jy-Young
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.11a
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    • pp.76.1-76.1
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    • 2010
  • Recently, many efforts to solve the durability problem of PEM fuel cell are carried on constantly. However, despite this attention, durability researches of gas diffusion layer (GDL) are not much reported yet. Generally, GDL of PEM fuel cell experiences three external attacks, which are dissolution of water, erosion of gas flow, corrosion of electric potential. In this study, among these degradation factors, carbon corrosion of electric potential was focused and investigated with accelerated carbon corrosion test. Through the test, it is confirmed that carbon corrosion occurred at GDL, and corroded GDL decreased a performance of operating fuel cell. The property changes of GDL were measured with various methods such as air permeability meter, pore distribution analyzer, thermo gravimetric analyzer, and tensile stress test to discover the effects of carbon corrosion. Carbon corrosion caused not only loss of weight and thickness, but also degradation of mechanical strength of GDL. In addition, to analysis the reason of GDL property changes, a surface and a cross section of GDL were observed with scanning electron microscope. After 100 hours test, the GDL showed serious damage in center of layer.

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An Overview on Hydrogen Uptake, Diffusion and Transport Behavior of Ferritic Steel, and Its Susceptibility to Hydrogen Degradation

  • Kim, Sung Jin;Kim, Kyoo Young
    • Corrosion Science and Technology
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    • v.16 no.4
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    • pp.209-225
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    • 2017
  • Development of high strength steel requires proper understanding of hydrogen behavior since the higher the steel strength the greater the susceptibility of hydrogen assisted cracking. This paper provides a brief but broad overview on hydrogen entry and transport behavior of high-strength ferritic steels. First of all, hydrogen absorption, diffusion and trapping mechanism of the steels are briefly introduced. Secondly, several experimental methods for analyzing the physical/chemical nature of hydrogen uptake and transport in the steels are reviewed. Among the methods, electrochemical permeation technique utilized widely for evaluating the hydrogen diffusion and trapping behavior in metals and alloys is mainly discussed. Moreover, a modified permeation technique accommodating the externally applied load and its application to a variety of steels are intensively explored. Indeed, successful utilization of the modified permeation technique equipped with a constant load testing device leads to significant academic progress on the hydrogen assisted cracking (HAC) phenomenon of the steels. In order to show how the external and/or residual stress affects mechanical instability of steel due to hydrogen ingress, the relationship among the microstructure, hydrogen permeation, and HAC susceptibility is briefly introduced.

A Total Analysis of Study on Factor Affecting the Usage Level and Performance of e-trade (전자무역의 활용수준과 성과 영향 요인에 관한 연구의 종합 분석)

  • Lee, Yong-Keun;Kim, Seung-Chul;Jung, Jae-Woo
    • International Commerce and Information Review
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    • v.6 no.1
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    • pp.99-126
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    • 2004
  • E-Trade is expected to dominate the global trade in the 21st century and thus is being introduced as a major policy assignment for each development country. e-trade has the potential to accelerate existing trends and introduce new ways of conducting trade. and e-trade is an alternative to strengthen international competitiveness. therefore, we needs to quickly adjust to this new method of e-trade and provide a number of policy suggestions that it can make best use of. However, successful implemetation, diffusion and usage of e-trade system require cooperation, commitment and the trust of all participating members in international trade process. A number of interorganizational, intraorganizational and innovation factors can influence both the extent to which e-trade is diffused and the level of subsequent performance that accure to participating firms. Considering the characteristics of e-trade, the proposed factors are based on an interdisciplinary study. The research model is based on the theories of innovation diffusion, inter-organizational system, and IS implementation. The factors proposed for this study of external firm factors, internal firm and perception factors.

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XBRL Adoption Process in Malaysia Using Diffusion of Innovation Theory

  • ILIAS, Azleen;GHANI, Erlane K.;AZHAR, Zubir
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.2
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    • pp.263-271
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    • 2021
  • The study examined the XBRL adoption process of Malaysian Business Reporting System (MBRS) by utilizing Everett Rogers' Diffusion of Innovation (DOI) theory. The study focused on the three phases, namely, knowledge gathering and persuasion phase, decision-making phase, and implementation phase of XBRL adoption process gathered from a government agency in Malaysia. This study employs a qualitative case study that incorporates semi-structured interviews with four members of the regulator. The results reveal that the regulator has realized the advantages, management support, and need to skills development in phase one. On the other hand, in phase two, it finds the way the regulator makes decision related to XBRL taxonomy and submission template, platform, tools and software. Through phase three, the regulator is concerned with the complexity of XBRL taxonomy, resources, external support, promotion, stakeholder involvement, limited trading pressure, critical mass, and professional bodies. The factors from each phase suggest an in-depth understanding on the experience of XBRL through the development of MBRS that provides a success story to the other government agencies and regulators in Malaysia. This study provides several insights on the factors that could contribute to the adoption of XBRL and the Diffusion of Innovation theory adoption process.