• Title/Summary/Keyword: AC/A 비

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The Optimum Binder Ratio for High-Strength Self-Leveling Material (고강도 Self-Leveling재의 최적 결합재비)

  • 김진만
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2002.11a
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    • pp.67-76
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    • 2002
  • Self-leveling material(SLM) is one of the floor finishing materials which make flat surface like as water level by itself in a short time. So it is possible to increase construction speed and enhance economical efficiency. In this study, author intended to develop SLM for the industrial warehouse and factory loading heavy weight machinery and vehicles. The demanded properties for this type of SLM are above 20mm of flow value and above 300kgf/cm2 of 28-days compressive strength. To possess demended strength and fluidity, SLM have to be composed of many types of binders and chemical additives. So it is difficult to decide suitable mixing proportion of composition materials. In this study, author investigated the weight percentage effect of main composition materials for high-strength self-leveling material, by experimental design such as tables of orthogonal arrays and simplex design, and by statistical analysis such as analysis of variance and analysis of response surface. Variables of experiments were ordinary portland cement(OPC), alumina cement(AC), anhydrous gypsum(AG), lime stone(LS) and sand, and properties of tests were fluidity of fresh state and strength of hardened state. Results of this study are showed that suitable mix proportions of binders for the high strength self-leveling materials are two groups. One is 78~85.5% OPC, 7.5~9.5% AC, 9~12.5% AG and the other is 72.5~78% OPC, 9~12.5% AC, 13~l5% AG.

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A Study on the Relationships between the Electrooptical Characteristics and Working Gas Xe+Ne+Kr (AC PDP의 전기 광학적 특성과 동작 가스 Xe+Ne+Kr의 구성비와의 상관관계에 관한 연구)

  • Park, Chung-Hoo;Yoo, Soo-Bok;Lee, Don-Kyu
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.2
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    • pp.9-14
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    • 2007
  • Recently, in order to improve the characteristics of operating voltage, brightness, discharge time lag, luminous efficacy of ac PDP, the PDP with high Xe partial pressure has been investigated. However, the serious problems in this case is to increase the operating voltage of ac PDP. In this study, in order to meet this problem the influences of kr gas in Ne-Xe-Kr ternary gas system is investigated for wide range of Xe partial pressure in terms of operating voltage, driving margin, luminance and luminous efficacy.

A Study about interception on Hurtfulness Site using Aho-Corasik machine (AC 머신을 이용한 유해 사이트 차단에 관한 연구)

  • 정현수;정규철;김후남;박기홍
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2004.05b
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    • pp.541-544
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    • 2004
  • Change is doing our life more conveniently and abundantly by knowledge information society, but side effect and that is happening considerable and gropes solution in reply that did not expect in advance is urgent real condition. It can be called one of representative dysfunction of information-oriented society that human nature is revealed in open state to great many objectionable material and poisonous information such as violence kind that teenagerses who do not grow are gotten abroad through Information network system yet. So, to solve these fallacy, word-weighting process, where several harmful words which can be optained in internet site are discriminance and weighted, is utilized by using AC machine. At the result, the isolation rate of harmful site rose up to 90%, which means this process is greatly efficient.

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The new fence structure in the AC PDP for a high luminance and luminous efficiency (AC PDP의 휘도 및 효율 향상을 위한 새로운 Fence 전극구조)

  • Yoon, Cho-Rom;Cho, Sung-Yong;Seok, Chang-Woo;Han, Moon-Ki;Ha, Chang-Seung;Park, Cha-Soo;Lee, Hae-Jun;Park, Chung-Hoo
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.1420-1421
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    • 2007
  • 기존의 fence전극구조는 ITO구조에 비해 방전전류가 감소함에도 불구하고 휘도가 대폭 감소하여 효율이 떨어지는 것으로 알려져 있다. 따라서 효율 상승을 위하여 다음과 같은 fence구조를 제안하였다. 실험은 reference(Conventional T-전극구조)와 제안된 구조들로 구성되어 있는 4-inch AC-PDP test Panel을 직접 제작하여 discharge current, luminance, luminous efficiency를 측정하여 비교하였다. 제안된 구조들은 방전전류 최대 10%감소, 휘도는 최대 20%증가하였고 효율면에서도 최대 20%의 상승을 보였다.

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Development of Transgenic Carrot Oral Vaccine to Protect against Diarrhea of Piglets (자돈 설사병 방지를 위한 경구백신용 형질전환 당근 개발)

  • 이영선;황철호
    • Journal of Plant Biotechnology
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    • v.29 no.4
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    • pp.287-293
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    • 2002
  • We are trying to develop a transgenic carrot with aims of production and delivery of oral vaccine against microbial enteropathogen using a K88ac pilin gene. A K88ac antigen (pilin) gene was isolated by PCR from the K88ac genomic DNA. The pilin gene was constructed in pGA748 and introduced via Agrobacterium tumefaciens to the explants of carrot hypocotyl and then 494 transgenic lines were established. The amounts of the K88ac antigen produced in each of the cell lines were determined by western and two elite cell lines (M1-17, Y14-1) were selected based on higher levels of expression of the antigens as well as rate of cell growth and efficiency of embryogenesis. In order to test an immunization induced by oral administration of the transgenic carrot, serum of the mice fed with the carrot vaccine were tested in ELISA. It tumed out that the mice fed with 3 g of transgenic carrot showed a similar level of antibody compared to those applied with 10 $\mu\textrm{g}$ of the purified recombinant pilin protein. Besides, various clinical responses were measured after challenging with ETEC K88ac strain to the piglets experiencing an oral immunization with the transgenic carrot. The piglets fed with carrot vaccine showed a lower level of diarrhea in fecal score compared to those fed with non-transgenic carrot. A higher level of increase in weight of the piglets fed with the transgenic carrot vaccine was observed comparing to those fed with non-transgenic carrot as control.

A study of Discharge characteristics of AC PDP with Lock shape ITO elctrode (Lock shape ITO전극을 가지는 AC PDP의 방전특성연구)

  • Choi, Yong-Suk;Nam, Hyung-Woo;Wi, Sung-Suk;Song, In-Cheol;Ok, Jung-Woo;Kim, Dong-Hyun;Lee, Hae-June;Lee, Ho-Jun;Park, Chung-Hoo
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.1433_1434
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    • 2009
  • AC PDP는 다른 디스플레이들에 비해 높은 소비전력과 낮은 발광효율에 대한 문제를 가지고 있다. 이러한 문제를 해결하기 위해 본 연구에서는 기존의 Stripe shape ITO(Indium Tin Oxide)전극구조에서 Lock shape ITO전극구조를 제안하였다. 이 구조는 long gap을 가진 Square형태의 전극구조에 'ㄱ'형태의 점화전극을 추가한 구조로, 소비전력을 줄이기 위해 전극면적을 줄이고, discharge current를 제어 하였다. 또한 점화전극 구조에 의해 늘어난 gap으로 인한 방전개시전압 상승을 줄 일수 있었다. 실험은 Stripe shape ITO구조와 Lock shape ITO의 전극구조들로 구성되어 있는 Test Panel을 직접 제작하여 방전개시전압, 휘도, 소비전력, 발광효율을 측정하여 그 특성들을 비교하였다. 그 결과 제안된 전극구조에서의 소비전력은 reference 구조에 비해 최대 18% 감소하였고, 발광효율은 최대 13% 상승을 함을 보였다.

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Control of Railway Power Quality Conditioner for AC Electrified Railway Systems (교류 전기철도 급전시스템을 위한 철도용 전기품질 보상장치의 제어방법)

  • Park, Han-Eol;Song, Joong-Ho
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.8
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    • pp.48-54
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    • 2010
  • The AC electrified railway systems have the power quality problems such as the harmonic distortion, the reactive power and the three-phase imbalance because of the electrical load characteristics of locomotives, which are non-linear single-phase. These power quality problems have a bad effect on not only AC electrified railway systems but also other electric systems connected together. The RPQC (railway power quality conditioner) can compensate such power quality problems in the AC electrified railway systems. In this paper, a novel RPQC control method based on SRF (synchronous-reference-frame) control is proposed. The proposed RPQC control method can compensate effectively the harmonic currents, the reactive power and the load imbalance. The validity and the effectiveness of the proposed RPQC control method are illustrated through the simulations.

The Association between Perceived Stress and Depression in University Students: Moderated Effect of Ego gram (흡연 여부에 따른 대학생의 스트레스와 우울의 연관성 분석: Ego gram의 조절효과)

  • KIM, Han-Kyoul;Byeon, Jieun;Kim, Kyu-min;Rhee, Hyunsill
    • Journal of Digital Convergence
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    • v.18 no.2
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    • pp.291-300
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    • 2020
  • The purpose of this study is to identify the moderate effect of Ego gram between perceived stress and depression from university student according to smokers/non-smokers. The result of study shows the strong association between stress and depression. On the other hand, the moderated effect of Ego gram was different in the smoking and non-smoking groups. In the non-smoker group, the CP tendency which is pursued strictly control by oneself had a moderating effect on depression, and in the smoker group, the A tendency, which had excellent adaptability, creativity, and autonomy, reduced depression. On the other hand, in the smoking group, the AC tendency also showed a significant moderating effect. It is reported that a high AC tendency may cause a feeling of helplessness about the situation and cause negative emotions to conform to reality. This suggests that the individual's ego state to approach emotional state such as stress and depression should be considered together.

A Fast Scene Change Detection Algorithm using Direct Feature Extraction from MPEG Compressed Videos (MPEG 압축 비디오로부터 특징 정보의 직접 추출을 통한 바른 장면 전환 검출 알고리즘)

  • 김영민;이성환
    • Proceedings of the Korean Information Science Society Conference
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    • 1999.10b
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    • pp.404-406
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    • 1999
  • 비디오 데이터의 효율적인 저장, 관리를 위해서는 장면 전환 검출을 통한 비디오 분할 기술에 대한 연구가 필요하므로, 최근 들어 압축 비디오상의 특징 정보를 직접 추출하여 장면 전환 검출에 사용하는 방법에 대한 연구가 많이 이루어지고 있다. 본 논문에서는 MPEG 압축 비디오 상의 에지 정보를 복호화 과정을 거치지 않고 직접 추출하여 장면 전환 검출에 사용하는 새로운 방법을 제안하였다. 이산 여현 변환(DCT)된 블록내 AC 계수의 부호를 통해 에지의 모양을 알아내었으며, AC 계수간의 상관 관계를 통해 에지의 방향과 세기를 측정하여 프레임을 정합하는 방법을 사용하였다. 실험 결과 사용한 특징 정보가 명도나 색상 변환에 무관하여 잘못 검출하는 비율이 현저히 적었으며, 영상을 완전 복호화한 후 에지를 구하여 장면 전환 검출을 하는 방법에 비해 약 5-6배 속도가 빠름을 확인할 수 있었다.

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Torsional Stress Analysis of Turbine-Generator Connected to HVDC System (HVDC단에 연결된 터빈-발전기의 비틀림 스트레스 해석)

  • 김찬기
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.50 no.8
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    • pp.416-426
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    • 2001
  • This paper deals with the impact of an inverter station on the torsional dynamics of turbine-generator which is located at the inverter side of a HVDC-AC network power system. The studies show that the torsional stress of turbine-generator depends on the AC network fault locations because of the commutation failures of inverter station. And the torsional stress induce fatigue in the shaft material and reduce the shaft life-time. So, the purpose of this paper is to analysis the torsional stress of turbine-generator shaft at inverter side, to find the checked points of turbine-generator. The EMTDC program is used for the simulation studies.

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