• Title/Summary/Keyword: 조차

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An Investigation of the Suspended Load (부유사(浮遊砂)에 관한 조사연구(調査研究) -특히 군산항(群山港)에 대하여-)

  • Ahn, Soo Hahn;Lee, Jong Kyu;Yeo, Woon Kwang
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.3 no.2
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    • pp.17-29
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    • 1983
  • The siltation of the Gun-San New Harbour is a serious problem to keep the available water depth of the basin. So, in order to make clear the behaviour of the suspended load flowing in and out of the Gun-San New Harbour obviously, the samples of the suspended load at the appropriate points were collected in the estuarine area near the Harbour and at the same time the tidal current velocities measured. Their suspended load concentrations and salinities were analyzed, and emphasis has been placed on the characteristics of the suspended load concentrations and on the relationship between the concentration and the tidal flow as well as the wave. As a result, the authors obtained the followings; 1) The main source of the suspended load in the Geum River estuarine area is transported from its upstream during floods and deposited rapidly due to the salt water, and the settled sediment is resuspended due to the tidal flow and the wave action, transported and settled again. Such a process is periodically repeated according to the tidal curve. 2) The concentrations are, in general, becoming larger with the increase of the tidal range and the wave height, and vice versa. Especially, the concentrations are relatively large in the winter season of which the wave height is larger than another seasons.

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SEASONAL VARIATIONS OF CHLORIDE, CALCIUM AND MAGNESIUM ION CONCENTRATIONS IN NAGDONG RIVER WATER AT MUL GEUM INTAKE STATION OF BUSAN CITY WATER FROM MARCH 1974 TO MARCH 1975 (낙동강 물금구취수장 상수도원수의 염화이온 칼슘 마그네슘 농도의 연간변동에 대하여(1974년-1975년))

  • WON Jong Hun;YANG Han Serb
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.11 no.2
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    • pp.103-109
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    • 1978
  • The contents of chloride ion, calcium and magnesium in Nagdong River water were determined at Mul Geum where the intake station for Busan city water is located. Samples were taken in spring and neap tides of every month from March 1914 to March 1975. The range and mean values of the chloride ion and total hardness were 5.12-39.4ppm, 11.9ppm; 27.8-70.8ppm, 49.5ppm respectively from March 1974 to January 1975. The highest values were found in the period of the widest tidal range of a year, from February 9 to March 9 in 1975, such as tile ranges and means of chloride ion and total hardness were 10.8-876 ppm, 89.8ppm : 48.0-407ppm, 89.9ppm. On several days of this period those concentrations were over the criteria of drinking water, 150 ppm in chloride and 300ppm in total hardness. Chloride ion concentration was increased with increasing of water level of the Nagdong River at Mul Geum. The patterns of the variations of tide level were similar to that of water level with delay of 2.5 hours in spring tides and 3 hours in neap tides.

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Applicability of a new tidal power system with reduced environmental impact (환경영향을 저감한 신형 조력발전기술 적용성 검토)

  • Park, Young Hyun;Youn, Daeok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.12
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    • pp.112-117
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    • 2017
  • Interest in the development of renewable energy sources has been increasing over the past 10 years and the west coast of Korea is one of the most favorable regions for tidal power. Barrage type tidal power is representative of the experience of installation and operation of such power sources for long periods. However, future projects for barrage type energy sources are either delayed or closed due to their environmental impact. For this reason, we applied a new tidal power technology with minimized environmental impact to a candidate area in the west coast and then analyzed its feasibility. The new tidal power technology is called Dynamic Tidal Power (DTP). Because its verification is impossible both in the laboratory and field, a numerical model is used for the evaluation of DTP. This new technology produces tidal power by means of the phase difference caused by diffraction on both sides of a dike built tens of km away from the coast. Because DTP is theoretically able to almost double the tidal range, it is expected to be applicable to even a small tidal area. Unlike the barrage type, it has the advantage of reducing the environmental impact by not enclosing the sea water. The west coast of Korea is close to the metropolitan area and has a high tidal range and, thus, it is thought to be a suitable candidate for tidal power.

Strategies for Channel Innovation of True Korea Ginseng Distribution Using Genuine Guarantee System (진품확인시스템을 활용한 고려인삼 유통혁신전략)

  • 권혁인
    • Journal of Ginseng Research
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    • v.25 no.4
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    • pp.171-177
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    • 2001
  • Lately, the Korean ginseng was confronted with the sale crisis in world markets from the various circumstance. One of important difficulties is overspreading of Korean ginseng imitative in foreign markets. In Korean markets also, chinese ginseng was imported illegally and manufactured as Korean ginseng, which was resulted inthe damage of Korean ginseng brand. The most essential problem is misunderstanding of Korean ginseng 。 s information in the foreigner. In this paper, we developed a genuine guarantee system to identify the true Korean ginseng through internet and geographic cording system of Korean ginseng products. This system can be applied to the enforcement of Korean ginseng sale to international markets.

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Improvement in Image Rejection of Multi-Port Junction-based Direct Receivers (다중 접합 기반 수신기의 영상 제거비 평가 및 향상 방법)

  • Park, Hyung Chul
    • Journal of the Institute of Electronics and Information Engineers
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    • v.49 no.9
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    • pp.43-48
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    • 2012
  • This paper presents an iterative single-frequency continuous-wave signal-based I/Q regeneration method for improving image-rejection performance of multi-port junction-based direct receivers (MPDRs). This paper analyzes I/Q regeneration in MPDRs as I/Q mismatch compensation for direct conversion receivers. Based on the analysis, this paper evaluates the accuracy of I/Q regeneration in terms of the image-rejection ratio (IRR). The proposed method improves the IRR performance more than 20 dB compared to existing I/Q regeneration methods. Simulation results show that MPDRs using the proposed method can achieve an IRR of more than 70 dB, and that the bit error rate performances are almost the same as those of conventional coherent demodulators, even in fading channels.

Environment-Adaptive and Real-Time Rendering of Fluids for Cartoon Style Game (카툰 스타일 게임을 위한 환경 적응적 실시간 유체 렌더링)

  • Kim, Kwang-Tae;Park, Kyoung-Ju
    • Journal of Korea Game Society
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    • v.12 no.5
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    • pp.57-66
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    • 2012
  • This paper to the scene to fit the fluid can be expressed as cartoon-style real-time method is proposed. As a matter of fact the fluid color in the simulation in which both reflection refraction and color tones are different in both cases. This paper light, water, terrain, time, etc. with cartoon-style representation of the fluid, adaptive way is proposed. Experimental implementation of the existing and proposed methods were compared with the results. This cartoon-style rendering of the existing research methods and the proposed method and at the same time using cartoon-style games that can be represented by the entire system could offer.

A Study on Contents Sharing using Domain in Digital Home (디지털 홈에서 도메인을 이용한 콘텐츠 공유에 대한 연구)

  • Lee, Jung-Soo;Kim, Jeong-Hyun;Park, Ji-Hyun;Yoon, Ki-Song;Suh, Young-Ho
    • 한국HCI학회:학술대회논문집
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    • 2009.02a
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    • pp.745-748
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    • 2009
  • DRM(Digital Rights Management) and CAS(Conditional Access System) have been used for preventing the illegal use of contents. These schemes had caused inconvenience to even legal users about contents, however, as restricting movement and playing. As going increment of requirement about the flexible usage of the content in digital home recently, we propose a new method that can easily share and use the DRM applied contents using domain concept. As setting the domain license in the extent of license that the existing DRM has been provided, the proposed system can cut off the illegal use and distribution of the content.

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Development of Reliability Analysis Procedures for Repairable Systems with Interval Failure Time Data and a Related Case Study (구간 고장 데이터가 주어진 수리가능 시스템의 신뢰도 분석절차 개발 및 사례연구)

  • Cho, Cha-Hyun;Yum, Bong-Jin
    • Journal of the Korea Institute of Military Science and Technology
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    • v.14 no.5
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    • pp.859-870
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    • 2011
  • The purpose of this paper is to develop reliability analysis procedures for repairable systems with interval failure time data and apply the procedures for assessing the storage reliability of a subsystem of a certain type of guided missile. In the procedures, the interval failure time data are converted to pseudo failure times using the uniform random generation method, mid-point method or equispaced intervals method. Then, such analytic trend tests as Laplace, Lewis-Robinson, Pair-wise Comparison Nonparametric tests are used to determine whether the failure process follows a renewal or non-renewal process. Monte Carlo simulation experiments are conducted to compare the three conversion methods in terms of the statistical performance for each trend test when the underlying process is homogeneous Poisson, renewal, or non-homogeneous Poisson. The simulation results show that the uniform random generation method is best among the three. These results are applied to actual field data collected for a subsystem of a certain type of guided missile to identify its failure process and to estimate its mean time to failure and annual mean repair cost.

Guideline for Field Partial Discharge measurement of Underground Transmission Level XLPE Cable (지중송전 XLPE케이블 활선상태 PD 측정기술 향상을 위한 가이드라인 제시)

  • Park, Jin-Woo;Choi, Kyung-Kyu;Lee, Joen-Seon
    • Proceedings of the KIEE Conference
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    • 2008.10a
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    • pp.141-142
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    • 2008
  • 국내 지중송전선로는 주로 XLPE케이블과 OF케이블로 구성된다. 1971년 154kV급 OF 케이블이 최초로 한전에 의해 상용운전에 들어간 후 XLPE 케이블 지중선로가 1983년부터 병용운전 되고 있으며 OF케이블의 경우 절연유의 사용으로 인한 화재의 위험과 환경오염 문제 등으로 인하여 점진적으로 XLPE케이블로 대체되는 추세에 있다. 하지만 내전압 시험, 절연저항이나 누설전류 측정, $tan{\delta}$ 측정 등으로 진단이 가능했던 OF케이블과는 달리 XLPE케이블의 경우 종래의 시험을 통한 진단은 한계가 있고 부분방전을 통한 진단이 가장 효율적인 진단방법으로 제시되어 국내외 XLPE케이블의 진단을 위해 운영되고 있으며 보다 정확한 PD측정을 위한 연구가 계속 진행되고 있다. 지난 10년여간의 국내외 연구결과 XLPE케이블에 대한 PD 측정기술의 정확성은 상당히 향상되었고 그 결과물로서 수많은 폭정 장비와 기법이 개발되어 오늘날 널리 보급되고 있다. 하지만 여전히 측정된 Data에 대한 해석은 일부 전문가들에게 조차 복잡하고 어려운 일로 남아 있다. 자칫 그릇된 해석은 향후 큰 사고로 이어질 수 있으므로 선로 운영자의 입장에서는 측정결과의 신뢰성에 민감할 수밖에 없다.

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Fast Gabor Feature Extraction for Real Time Face Recognition (실시간 얼굴인식을 위한 빠른 Gabor 특징 추출)

  • Cho, Kyoung-Sik
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2007.06a
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    • pp.597-600
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    • 2007
  • Face is considered to be one of the biometrics in person identification. But Face recognition is a high dimensional pattern recognition problem. Even low-resolution face images generate huge dimensional feature space. The aim of this paper is to present a fast feature extraction method for real time human face recognition. first, It compute eigen-vector and eigen-value by Principle component analysis on inputed human face image, and propose method of feature extraction that make feature vector by apply gabor filter to computed eigen-vector. And it compute feature value which multiply by made eigen-value. This study simulations performed using the ORL Database.

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