• Title/Summary/Keyword: Pre-Breakdown

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A Study on ESD Robustness of Output Drivers for ESD Design Window Engineering (ESD 설계 마진을 위한 출력드라이버 ESD 내성 연구)

  • Kim, Jung-Dong;Lee, Gee-Du;Choi, Yoon-Chul;Kwon, Kee-Won;Chun, Jung-Hoon
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.48 no.12
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    • pp.31-36
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    • 2011
  • This paper investigates the ESD robustness of the stacked output driver with a 0.13um CMOS process. To represent an actual I/O system, we implemented stacked output driver circuits with pre-drivers and a rail-based power clamp. We implemented eight kinds of circuits varying pre-driver input connections and stacked driver size. The test circuits are examined with TLP measurements. It is shown that breakdown current and voltage can be increased by connecting the pre-driver input to a power supply and using stacked devices of a similar size. Based on the test results, design guideline is suggested to improve ESD robustness of the stacked output drivers.

Survey of the Effects on 154kV Electrical Power Customers' Productive Activities by the Instantaneous Voltage Sag or Interruption in Power System (전원측 정전 및 순간전압강하가 수용가에 미치는 영향 조사)

  • Lee, Seok-Kyu;Park, Hee-Woo;Kim, In-Geon;Lee, Jong-Hak;Kim, Young-Ju
    • Proceedings of the KIEE Conference
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    • 2001.05a
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    • pp.273-274
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    • 2001
  • This paper presents the effects on 154kV electrical power customers' productive activities by the instantaneous voltage sag or interruption in power system. According to the survey all respondents (8customers) experienced the breakdown of facilities when instantaneous voltage sag over about twenty percents of pre-fault occurred in power system.

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Treeing Phenomena in the Home-made Solid Organic Insulating Materials (국산유기절연재료의 Treeing현상)

  • 성영권;이헌용;이계호;유기한
    • 전기의세계
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    • v.26 no.2
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    • pp.57-65
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    • 1977
  • In roder to investigate the influence of treeing on electric breakdown of solid organic insulator the initiation and growing mechanism of tree itself, and the correlation between corona discharge and treeing phenomena in solid orgainc insulating materials, several experiments were carried out by means of needle test on polymethyl-methacrylate. The obtained results showed that the existence of voids in specimen had important effects on initiation voltage of trees and, when the direct voltage was applied, the initiation voltage of trees increased by space charge effect. And also the stagnation phenomena due to the transfer of vacancy cluster or polymekr cage in specimen might beconsidered in process of growth of trees, and corona discharge seemed to be the pre-phenomena of treeing because trees were normally initiated by internal discharge in voids.

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The Analysis of Townsend Enuation Based on Linealized Least Squares Method (최소자승법을 적응한 Townsend법의 해석)

  • 백용현;하성철
    • 전기의세계
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    • v.27 no.2
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    • pp.69-74
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    • 1978
  • There have been a number of experimental or theorethical investigations of transport coefficient for electrons in the field of gas. In this paper the authors present the method by which Townsend first ionization doefficient (.alpha.) or attachment coefficient (.eta.) can be deduced easily and precisely by means of analyzing Townsend equation based on linealized least squares method. The apparent ionization coefficient (.alpha.-.eta.)/p have been analyzed from the experimental data by applying the new method above mentioned. And the values of (.alpha.-.eta.)/p in SF$_{6}$ as a function of E/p were agreement with the values measured by Bhalla et al. who analyzed th experimental pre-breakdown currents. In the same way (.alpha.-.eta.)/p in N$_{2}$O had a same tendency to that of Folkard et al.l.

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The Effect of Pre-compaction on Density and Mechanical Properties of Magnetic Pulsed and Sintered $Al_2O_3$ Bulk

  • Hong, S.J.;Lee, J.K.;Lee, M.K.;Kim, W.W.;Rhee, C.K.
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.967-968
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    • 2006
  • This research reports for the successful consolidation of $Al_2O_3$ powder with retained ultra-fine structure using MPC and sintering. Measurements in the consolidated $Al_2O_3$ bulk indicated that hardness, fracture toughenss, and breakdown voltage have been much improved relative to the conventional polycrystalline materials. Finally, optimization of the compaction parameters and sintering conditions will lead to the consolidation of $Al_2O_3$ nanopowder with higher density and even further enhanced mechanical properties.

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Design of Fuse Mounted Elbow Connector (퓨즈가 내장된 엘보접속재의 설계)

  • 최경선;이철호;송일근;권태종;권영복;한명관
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.11a
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    • pp.383-386
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    • 2000
  • Fuse mounted elbow connector used for pad mounted transformer was designed and investigated. Requirements of electrical ratings such as partial discharge, ac withstand voltage and impulse voltage and material properties were proposed in accordance with IEEE 386 and pre-standard (PS) 147-219∼229 of KEPCO. The connector can be jointed with pad mounted transformer and current limiting fuse which is installed inside of the connector easily replaced with new one in the case of breakdown of the fuse. Electric field analysis was also introduced in other to verify the reliability of the design.

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A Study on the Data-based WBS Model for Train Control System to Improve a Maintenance work (열차제어시스템 유지관리 업무 개선을 위한 데이터 기반 WBS 모델 연구)

  • Jeon, Jo Won;Kim, Young Min;Park, Bum
    • Journal of the Korean Society of Systems Engineering
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    • v.18 no.1
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    • pp.99-104
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    • 2022
  • In this paper, to increase the maintenance efficiency of the urban railway train control system and to build a standard data system, we collect as much as possible structured, unstructured, and semi-structured data, and collect data by sensing and monitoring the system status and system status and monitoring. pre-process function data(Identification, purification, integration, transformation) through effective data classification and maintenance activities business classification system was studied. The purpose of this is to define the data matrix model by considering the relationship with the data generated and managed in the O&M stage of the train control system operated by the urban railway together with the WBS model, and to reflect and utilize it in practice.

The Design & Effect Analysis of Project Objective Management Information System for National R&D cooperated by Industries, Universities and Government-supported research institutes (국가 산.학.연 협력 연구개발을 위한 과제목표관리 정보시스템의 설계 및 효과 분석)

  • Sohn, Kwon-Joong;Yoo, Wang-Jin;Lee, Cheol-Gyu
    • Journal of Technology Innovation
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    • v.16 no.1
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    • pp.107-139
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    • 2008
  • We studied how to achieve successful implementation of massive research and development projects requiring collaboration among industries, universities and government-supported research institute. We have set up an engineering process innovation model to be deemed most adequately for all practical purposes, relying on the theoretical studies on the merits and analysis of the effect of the information system based on Milestone Management, Work Breakdown Structures and Web, which is known to be effective for research project (schedule) management and the objective management, and implemented a real-world web-based project objective management system. After a review of various R & D Project Schedule Management methods, we found that this information system was very compatible with project objective management. This project objective management information system carries out research and development projects effectively and efficiently, getting together in cyber-space and sharing information, and has been equipped with an Early Warning Subsystem to allow for pre-analysis and timely response to potential problems arising from the course of the project. The system also contains an Executive Information System that in real time, automatically provides the management information required by managers with the rate of project progress (achievement, fulfillment and delay). Lastly, actual progress can be cross-checked through both on-line objective management on the web-based information system and design review meeting held on site, to improve the efficiency and validity of the information system. Moreover, overall effect was analyzed through questionnaires on how well the system and generated information meet requirements and on the ultimate impact of the system upon objective management and communication. The questionnaire on the system effect revealed that the information system was useful to objective management and communication, and that the quality of the system was more than acceptable as well.

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Clinical evaluation of the body fat breakdown effect during topical seaweed extracts treatment and in combination with the iontophoresis and phonophoresis(II) (이온삼투요법과 음파영동이 해조류 추출물의 체지방 분해에 미치는 효과 검정(II))

  • Suh Tae Soo;Park Jong Suk;Kim You Young;Lee Dong Ho
    • The Journal of Korean Physical Therapy
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    • v.16 no.1
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    • pp.70-84
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    • 2004
  • This study was carried out to evaluate the body fat breakdown during topical seaweed extract treatment and in combination with the iontophoresis, phonophoresis method to enhance skin absorption of lipolytic compounds. Of 24 female obesity subjects, 7 treated a gel types of seaweed extract only(control group) and 10 treated in combination with the iontophoresis(experimental group I) and 7 treated in combination with the phonophoresis(experimental group II). Topical treatment of each sample was designed for 2 weeks, treated with 2 times a day about $10m{\ell}$ on the abdomen, triceps, thigh and superior ilium, respectively. Experimental group treat with the iontophoresis and phonophoresis during 5 minutes immediately after topical treatment. After one and two weeks of topical treatment, measured body weight, body fat, skinfolds thickness respectively. Then venous blood samples were taken and analyzed serum lipids. The results were as follows; 1) There were decrement of body weight, $\%$ of body fat, superior ilium, triceps and thigh thickness between pre and post treatment in all group. Especially, there were more decrement of body weight, $\%$ of body fat in the iontophoresis treated group. 2) There were decrement in total CHOL, LDL, TRIG and increment in HDL in all group. These phenomena were predominant in the iontophoresis treated group. CHOL decrement in the experimental group were significant after two weeks iontophoresis treatment.

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Role of Peptides in Rumen Microbial Metabolism - Review -

  • Wallace, R.J.;Atasoglu, C.;Newbold, C.J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.12 no.1
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    • pp.139-147
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    • 1999
  • Peptides are formed in the rumen as the result of microbial proteinase activity. The predominant type of activity is cysteine ptoteinase, but others, such as serine proteinases, are also present. Many species of protozoa, bacteria and fungi are involved in ptoteolysis; large animal-to-animal variability is found when proteinase activities in different animals are compared. The peptides formed from proteolysis are broken down to amino acids by peptidases. Different peptides are broken down at different rates, depending on their chemical composition and particularly their N-terminal structure. Indeed, chemical addition to the N-terminus of small peptides, such as by acetylation, causes the peptides to become stable to breakdown by the rumen microbial population; the microorganisms do not appear to adapt to hydrolyse acetylated peptides even after several weeks exposure to dietary acetylated peptides, and the amino acids present in acetylated peptides are absorbed from the small intestine. The amino acids present in some acetylated peptides remain available in nutritional trials with rats, but the nutritive value of the whole amino acid mixture is decreased by acetylation. The genus Prevotella is responsible for most of the catabolic peptidase activity in the rumen, via its dipeptidyl peptidase activities, which release dipeptides rather than free amino acids from the N-terminus of oligopeptides. Studies with dipeptidyl peptidase mutants of Prevotella suggest that it may be possible to slow the rate of peptide hydrolysis by the mixed rumen microbial population by inhibiting dipeptidyl peptidase activity of Prevotella or the rate of peptide uptake by this genus. Peptides and amino acids also stimulate the growth of rumen microorganisms, and are necessary for optimal growth rates of many species growing on tapidly fermented substrates; in rich medium, most bacteria use pre-formed amino acids for more than 90% of their amino acid requirements. Cellulolytic species are exceptional in this respect, but they still incorporate about half of their cell N from pre-formed amino acids in rich medium. However, the extent to which bacteria use ammonia vs. peptides and amino acids for protein synthesis also depends on the concentrations of each, such that preformed amino acids and peptides are probably used to a much lesser extent in vivo than many in vitro experiments might suggest.