• Title/Summary/Keyword: 고율

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Effect of the Salt Concentration in Seafood Wastewater on the High-Rate Anaerobic Digestion (수산물 가공폐수내 염분농도가 고율 혐기성 소화에 미치는 영향)

  • Choi, Yong-Bum;Han, Dong-Joon;Lee, Hae-Seung;Kwon, Jae-Hyouk
    • Journal of Korean Society of Environmental Engineers
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    • v.35 no.10
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    • pp.730-736
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    • 2013
  • This study was conducted to examine the effects of the salt concentration in seafood wastewater on the high-rate anaerobic digestion process. In the general high-rate anaerobic process test, the TCODcr removal efficiency at 6 hr or more HRT was 81.1~0.7%, and the optimal HRT for seafood wastewater process was found to be 6 hr or more. The methane content in the biogas was 70.1~76.8% during the operation, and was hardly affected by the change in the influent load. The results of the anaerobic digestion efficiency according to the salt concentration showed that the removal efficiency of TCODcr was 83.4~89.2% below a $4,000mgCl^-/L$ salt concentration, and mid-70% at a $5,000mgCl^-/L$ salt concentration. Therefore, the salt concentration had to be kept below $4,000mgCl^-/L$ to ensure stable treatment efficiency. Below a $3,000mgCl^-/L$ salt concentration, the methane generation was 0.2999~0.346$m^3CH_4/kgCODrem.$, which was similar to the theoretical methane gas generation in STP condition ($0.35m^3CH_4/gTCODrem.$). The methane content in the biogas was 64.7~73.3% below a $3,000mgCl^-/L$ salt concentration, but decreased with an increase in the salt concentration, to 50.1~56.9% at a $4,000mgCl^-/L$ concentration.

A Study on the Need for Separation of Software Completeness Appraisal and Software Ready-made Appraisal (소프트웨어 완성도 감정과 기성고 감정 분리 필요성에 대한 고찰)

  • Kim, DoWan
    • Journal of Software Assessment and Valuation
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    • v.17 no.2
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    • pp.11-17
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    • 2021
  • In this study, problems of software completeness appraisal are pointed out and their solutions are presented by analyzing appraisal cases and judicial precedents. Completeness appraisal, ready-made appraisal, defect appraisal, and cost appraisal have been classified as and have been evaluated with extant software completeness appraisals. From a legal point of view, and in judicial precedents, however, there is a big difference between the definition of completeness and the completion rate. This is because the degree of completeness is evaluated under the premise that the software's development is complete, whereas the ready-made appraisal inspects the development progress of unfinished software. Often, in cases involving software completion rate, the total completion level is calculated by weighting each step of the software development process. However, completeness evaluations use the software's realization-operation as its sole criterion. In addition, another issue not addressed in existing software completeness appraisal cases is that there is no mention of who is responsible for software defects, whereas in case law, the responsible party is determined by finding who caused the dispute. In this paper, we systematically classify these problems, and present a novel evaluation method that separates software completeness evaluations from software completion evaluations.

시사특집 - 타이어 전쟁

  • Lee, Hang-Gu
    • The tire
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    • s.241
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    • pp.10-21
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    • 2009
  • 금융위기로 인한 세계 경기침체와 함께 우려되었던 보호무역주의가 타이어산업에서 불거지고 말았다. 미국정부가 중국산 타이어에 대해 고율의 관세를 부과하자 중국정부는 미국산 완성차와 닭고기의 수입관세를 대폭 인상하는 방안을 검토하면서 WTO에 미국을 제소하였다. 사사건건 대립각을 보여 왔던 미중 간에 무역전쟁이 터진 게 아닌가 우려된다. 또한 미국과 중국의 G2간의 분쟁이 자칫 여타 분야로 비화될 경우 고래 싸움에 새우등 터지는 결과가 나타나지 않을까 걱정이다. 이하에서는 미국과 중국간의 타이어분쟁 배경과 그 영향에 대해 살펴 보기로 한다.

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Simplified Calculation for Lightning Performance of Transmission Lines (송전선로뇌사고율의 간략화계산)

  • 지철근;이홍식
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.32 no.5
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    • pp.170-175
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    • 1983
  • A simplified method for the estimation of lightning performance of transmission Lines is described. Only one stroke current wave shape was used and the potentials of tower top and crossarms were computed at the two time points to obtain the critical stroke current for insulator flashover. Variation of the critical stroke current due to power frequency voltage was also takes into account. An applied example on 345KV Line model was shown and the calculated result was compared with the estimating curve suggested by Clayton & Young.

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신용카드산업구조와 경쟁정책

  • 김길태
    • Journal of Korea Fair Competition Federation
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    • no.85
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    • pp.14-23
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    • 2002
  • 독과점적인 시장구조를 경쟁적인 구조로 전환시키기 위한 방안으로 검토될 수 있는 대안은 여러 가지가 있을 수 있는데, 첫째로 현재 신규진입장벽으로 작용하고 있는 신용카드업 허가기준을 완화하는 방향으로 신용카드회사 수를 늘리거나, 허가제를 신고제로 전환하는 등의 검토가 필요할 것이고, 둘째로 경쟁을 통한 고율의 수수료 인하를 유도하며, 셋째로 신용카드 회사간의 자유로운 경쟁을 도모하고 소비자를 보호하기 위해서는 시장구조를 경쟁적인 구조로 전환시키는 노력과 함께 당해 시장에서 공정한 경쟁이 이루어지도록 시장감시활동을 강화하는 노력이 병행되어야 할 것이다.

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Ecological Studies on Rice Sheath Blight Caused by Rhizoctonia solani 1. The Difference of Disease Development Between Jinheung and Yushin (잎집무늬마름병의 생태학적연구 1. 진흥과 유신의 발병차이)

  • Kim Chang Kyu;Kang Chang Sik;Rim Sa Joon;Lee Eun Jong;Lee Kyung Hee
    • Korean journal of applied entomology
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    • v.20 no.2 s.47
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    • pp.71-75
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    • 1981
  • The percentage of lesion height vs. plant height was higher in Yushin than Jinheung within the same nitrogen level. The infection occurred at the same level of waterline and the symptoms developed with the same speed for two varieties, but the damage was greater in Yushin as the symptoms reached faster to the top due to the short length of the 1st and 2nd internodes from the top.

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Development of Polyvinyl Alcohol (PVA) Non-woven Separator Coated with ZrO2 Ceramic Nanoparticles for Improving Electrochemical Performance and Thermal Property of Lithium Ion Batteries (열 특성 및 전기화학 특성이 향상된 리튬이차전지용 ZrO2 코팅 PVA (Polyvinyl Alcohol) 복합 부직포 분리막 개발)

  • Kim, Ki Jae
    • Journal of the Korean Electrochemical Society
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    • v.20 no.3
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    • pp.49-54
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    • 2017
  • We develop a ceramic composite separator prepared by coating $ZrO_2$ nanoparticles with a poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) copolymer on a polyvinyl alcohol (PVA) mechanical support prepared by electrospinning technique to improve thermal properties. The gurley number of the ceramic composite separator shows much lower value than that of a PE separator even though it possesses the polymeric coating layer with ceramic nanoparticles. In addition, the proposed sample shows higher electrolyte uptake than PE separator, leading to enhancing the ionic conductivity of the proposed sample and, by extension, the rate discharge properties of lithium ion batteries. Thermal stability of the ceramic composite separator is dramatically improved without any degradation in electrochemical performance compared to the performance of conventional PE separators.

Evaluation of the Highway Traffic Safety Exposure Measures (도로교통안전도 비교평가지수 산정연구)

  • Kim, Ki Yong;Kim, Won Chul;Chang, Myungsoon
    • Journal of Korean Society of Transportation
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    • v.31 no.5
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    • pp.26-36
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    • 2013
  • Highway traffic safety evaluation of area on the basis of the accident rate has a limitation, thus its result is dependent on the exposure variables. It works an obstacle to decision making for effective budget execution. In this paper, we developed a methodology of taking simultaneously macroscopic exposure indicators into account in evaluating the safety using least squares method. The weight of exposure indicators to make up of highway traffic safety evaluation index is that accident rate per population, accident rate per registration vehicle and accident rate per length of road is 0.29, 0.52 and 0.19 respectively and calculated the highway traffic safety index of total local governments in Korea. The methodology to calculate highway traffic safety evaluation index proposed in this paper can be utilized in executing the traffic safety policies to increase the efficiency of investment about traffic safety budget.

Comparative analysis of lightning activity and transmission line faults (송전선로 주변의 낙뢰활동과 고장과의 비교 분석)

  • Kwak, Joo-Sik;Kang, Yeon-Woog;Koo, Kyo-Sun;Kweon, Dong-Jin
    • Proceedings of the KIEE Conference
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    • 2008.10a
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    • pp.147-148
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    • 2008
  • 본 논문에서는 154 kV 송전선포의 낙뢰고장기록과 선로주변의 낙뢰측정기륵을 분석하여 상관관계를 분식하였다. 낙뢰관측기록과 고장의 위치, 시각과 고장 메카니즘의 규명은 선로의 합리적인 대책수립에 유용한 정보를 제공할 수 있다. 6년간의 LPATS 및 KLDNet 관측기록과 송전고장기록을 이용하여 EMTP 해석모델과 뇌사고율 해석 S/W를 사용하여 뇌섬락 임계전류를 계산하고 뇌고장 유형을 분석 하였다.

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The Calculation of Lightning Outage Rates on 220kV Transmission Line in Libya (리비아 220 kV 송전선로의 뇌사고율 예측 계산)

  • Kang, Y.W.;Kwak, J.S.
    • Proceedings of the KIEE Conference
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    • 2005.07a
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    • pp.618-620
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    • 2005
  • 경제수준의 향상되면 안정적인 전력공급에 대한 국민의 기대는 증가된다. 최근 몇 년 동안 유가의 급등으로 리비아 경제 여건은 좋아지고 있으며 이에 따라 안정적인 전력공급에 대한 관심도 증가하고 있다. 최근 리비아(Libya) 수도 트리폴리(Tripoli)에서는 낙뢰에 의한 송전선 사고로 대규모 정전이 발생하였으며 이에 대한 대책수립이 요구되고 있다. 현재 한전에서는 송변전 및 배전분야에서 리비아 전력청(General Electric Company Of Libya)에서 발주한 용역을 수행중이다. 이에 따라 리비아 전력청에서는 리비아 220kV 송전선로의 뇌 사고율 분석 및 저감방안에 대한 검토를 요청하였으며 본 논문에서는 그 검토 결과를 설명하고자 한다.

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