• Title/Summary/Keyword: Burying

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An Experimental Study on the Use of the Recycled Thick Aggregate Using Ceramic Bricks (소성벽돌의 콘크리트 재생골재 사용 가능성에 관한 실험 연구)

  • Kwon, Ki-Hyuk;Kim, Hyoung-Jun;Yu, Hye-Ran
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.05b
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    • pp.501-504
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    • 2006
  • Recently, the Ceramic Bricks are getting increased due to demolishing aged buildings. But, disposal of the waste ceramic bricks has been relied on just burying into the ground. Regardless they can be used with recycled thick aggregate. Therefore the range of this study includes the experiment of slump test, compression, strength test and stress-strain analysis to the concrete the recycled thick aggregate with made by ceramic bricks. The reducing method of fine aggregate will be reviewed stand on analysis of this experimental result.

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Evaluation of Optimal Dredging Section Area for Burying Submarine Cable across the Coastal Waterways (연안항로내 해저케이블 매설을 위한 적정 굴착단면의 산정)

  • Kim, Hui-Jae;Lee, Dong-Hyeon;Lee, Jung-U
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2013.10a
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    • pp.151-153
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    • 2013
  • 최근 해양에너지플랜트 및 도서지역을 연결시키기 위한 해저 파이프라인 및 통신, 전력 케이블 매설공사가 빈번하게 이루어지고 있다. 특히, 연안항로를 가로지르는 해저케이블 매설공사에는 준설장비를 동원하여 해저부를 굴착하고 케이블을 부설한 후 상단을 덮어 보호하는 일련의 작업과정이 행해지며 이 과정에서 해저저질의 상태, 준설심도, 조류 또는 연안류의 흐름강도, 수심, 통항선박 등 다양한 조건에 따라 단면의 굴착심도 및 폭이 결정되며, 작업의 순서 또는 방법에 따라 여굴의 정도도 변하게 된다. 본 연구에서는 우리나라 서해안 실제해역에서 연안 도서를 연결하는 전력, 통신망의 개통을 위한 해저케이블 부설과 관련한 굴착단면의 실태를 실제 현장여건과 관련해서 적정단면과 준설물량의 산정을 다루어 해저환경변화에 대처하기 위한 기초자료를 제공하고자 하였다. 이를 위하여 대상해역에서 주요설계 지침에 따른 해저부 굴착단면의 평가와 적정단면을 검토하였으며, 이 단면에 따른 준설 적정물량을 산정하여 작업공정에 활용할 수 있도록 하였다.

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Characteristics of Sheath Circulating Current by Underground Transmission Systems Analysis (지중송전시스템 해석을 통한 시스순환전류 특성 분석)

  • Jung, Chae-Kyun;Lee, Jong-Beom;Kang, Ji-Won
    • Proceedings of the KIEE Conference
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    • 2002.07a
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    • pp.449-451
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    • 2002
  • Sheath circulating current rises from the change of sheath mutual impedance which is caused by imbalanced cable system, and different section length between joint boxes. However, mixed burying typo and imbalance section length take many parts of main reasons of sheath circulating current increment in domestic underground transmission power cables. Therefore, the increment reason and variation characteristics of sheath circulating current is analysed with simulation using EMTP/ATPDraw and measuring data of practical cable system which has a problem of exceeding sheath circulating current in this paper.

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The maintenance technology and their improvement of artificial reef fishing grounds (인공어초어장 관리조사기술의 현상과 개선방안)

  • Kim, Chang-Gil;Kim, Ho-Sang;Seo, Jang-Woo;Kim, Doo-Bong
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2005.11a
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    • pp.140-141
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    • 2005
  • This study describes the postinstallation maintenance technology of artificial reefs and their improvement. The maintenance technology of artificial reefs consists of four steps; the investigation of volumes of installed reefs, the removal of fishing gears entangled in reefs, the estimation of reef functions, and the establishment of surveyed results in the data base. The proper understandings of their steps is the key to improve the maintenance technology of artificial reefs.

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Analysis of Sheath Circulating Current in Underground Transmission Power Cables according to Unbalanced Factor (불평형 요소 변화에 따른 지중 송전선로의 시스순환전류 분석)

  • Choi, Soo-Hyun;Kim, Kyu-Ho
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.294-295
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    • 2015
  • Many unbalanced factors of underground transmission power cable, such as burying types and the length difference of the cable between each minor section, etc will cause the impedance unbalance and excessive circulating current between cables. So this paper presents the analysis of sheath circulating current in accordance with the distance between the center conductors and phase arrangement. ground resistance value changes on 154kV transmission system. Based on these simulation results, this paper will contribute to the reduction method of sheath circulation current.

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DIGITAL WATERMARK REPRODUCTION IMAGE ATTESTATION THAT USES PHASE ONLY CORRELATION METHOD

  • Inaba, Fumiya;Tanaka, Ken-Ichi
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2009.01a
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    • pp.508-511
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    • 2009
  • The infringement of the copyright is a problem by the distribution of digital contents copied illegally. The digital watermark is expected as a thing preventing unjust copying by burying information in digital data such as image, animation, the sound, TV, radio and movies. [1] [2]But a noise is included in a digital watermark reproduction image. So there is the case that the certification of the reproduction image has difficulty with. If a computer cannot recognize the information reproduced from digital watermarking, the information does not have a meaning. This paper aimed at improvement of the proof of a digital-watermarking reproduction image. And it is verified whether the difference of the form of a character affects the degree of correlation.

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A Study on the Characteristic and Rising Cause of Sheath Circulating Current by Analysis and Measurement (해석 및 측정을 통한 시스순환전류 특성 및 상승원인 검토)

  • Gang, Ji-Won;Yang, Hae-Won
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.51 no.10
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    • pp.525-533
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    • 2002
  • It is common to install multiple lines in the same route. Recently, excessive sheath circulating current was partially measured in underground cable systems of KEPCO. Especially, the installation type, unbalance section length between joint boxes and zero sequence current by distribution cable have an effect on the rising of sheath circulating current in the underground transmission system. If excessive current flows in sheath, sheath loss which is reduced the transmission capacity is produced. This paper describes the relation analysis of sheath circulating current and burying types. And also, a detailed analysis on rising cause and characteristic of sheath circulating current by considering various unbalanced conditions presents using analysis and measurement regarding cable systems which have the problem of excessive sheath circulation current.

Recycling of Wasted Batteries (폐전지의 재활용 고찰)

  • Park Young-Min;Cho Jai-Rip
    • Proceedings of the Korean Society for Quality Management Conference
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    • 2004.04a
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    • pp.291-297
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    • 2004
  • For the while, food wastes have been mainly gathered in a trash place in outskirt of Seoul to bury under the ground. Recently the residents near the area strongly refused to fetch those food wastes to their area because of the terribly bad smell. According to the statistic, the food wastes have around $30\%$ portion of total living wastes, which are more than other countries. Most of the food wastes have been simply buried or incinerated without deep consideration of resource recovery view. Such burying or incineration makes problem to the residents' life condition. So the first is to reduce as much as possible and the rest should be controlled to reuse as resources.

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Permanent Transvenous Endocardial Pacemaker Inevitably Implanted Two Electrode Leads (두개의 전극도자를 사용하게 된 Permanent Transvenous Pacemaker Implantation: 1례 보고)

  • Kwack, Moon-Sub;Lee, Hong-Kyun
    • Journal of Chest Surgery
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    • v.14 no.2
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    • pp.168-174
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    • 1981
  • Since cardiac pacemaker was first totally implanted by Chardack, Gage and Greatbatch [1966], the electrical circuity of the cardiac pacemaker has been improved, modified, and refined. The problem of transvenous electrodes, however, is still remained; this may be due to electrode displacement, exit and/or entrance block, lead fracture and insulation defects. In permanent cardiac pacing, Irreversible loss of function of the transvenous electrode catheter eventually requires insertion of new lead. Authors now report one case that disclosed easy displacement of electrode tip in early phase of implantation and then two years and five months later, malfunctioning electrode could not be withdrawn from the cardiovascular system because it has become firmly enclosed by fibrous tissue along its course from the vein tract to the right ventricle. Under such circumstances, the electrode catheter tip was left in tricuspid annulus after being sutured at its entrance and burying the loop of lead in generator pocket. New other one electrode was then reimplantation through left external jugular vein.

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Study on Hazen-Williams's C Value Estimation Considering Burying Period (통수년수 경과에 따른 C상수 변화곡선의 매개변수 추정)

  • Baek, Chun Woo;Kim, Seok Woo;Jo, Deok Jun;Kim, Eung Seok;Kim, Joong Hoon
    • Proceedings of the Korea Water Resources Association Conference
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    • 2004.05b
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    • pp.1464-1468
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    • 2004
  • 누후된 상수도 관망의 최적개량 계획수립을 위하여 많은 모형들이 개발되었으며, 이러한 모형들은 수리학적 타당성을 비롯한 다양한 인자들을 복합적으로 고려한다. 관망의 수리학적 타당성을 검토하기 위해서는 관망해석을 통해 절점 압력변화 등이 계획기간동안 만족되어야 하며, 이를 위해서는 관거의 노후정도에 따라 변하는 Hazen-Williams C상수의 변화를 고려하여야 한다. 그러나 Hazen-Williams C상수의 변화는 관거의 매설지역, 통수년수, 수질 등과 같은 여러 가지 복합적인 인자에 의해 차이가 있으며 실제 유량 및 압력자료 등에 대한 조사에 의해 매설된 관거의 C상수를 추정하여야 한다. 그러나, 내상 지역의 모든 관거에 대하여 유량과 압력을 조사하는 것은 경제적인 문제를 비롯한 여러 가지 이유로 불가능하므로 본 연구에서는 실측된 몇몇 지점의 유량 및 압력 변화에 따라 대상지역에 매설된 관거의 C상수 변화를 추정하는 알고리즘을 제시하였다.

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