• Title/Summary/Keyword: K252a

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A study on coefficient of permeability due to disturbed level of clay by direct permeability test with consolidation test (압밀시험중 직접투수시험에 의한 불교란 점토의 교란정도와 투수계수에 관한 연구)

  • Kim, Jae-Young;Kim, Dong-Hyun;So, Choong-Seop;Takada, Naotoshi
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.248-252
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    • 2005
  • Compressibility and deformability of clays change greatly when the clays are subjected to disturbance. These tendencies have been studied. However, the effect of the disturbance on the permeability that consists of consolidation properties has not yet been studied. In this study, relationship between permeability and volume ratio under the different degree of disturbance are experimently obtained. The results indicate that the relations are less influenced if the disturbance is less depending on the kind of soils.

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CHARACTERISTICS OF THE KAERI NEUTRON REFERENCE FIELDS FOR THE CALIBRATION OF NEUTRON MONITORING INSTRUMENTS

  • Kim, Bong-Hwan;Kim, Jang-Lyul;Chang, Si-Young;Cho, Gyu-Seong
    • Journal of Radiation Protection and Research
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    • v.26 no.3
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    • pp.243-248
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    • 2001
  • Neutron reference fields of Korea Atomic Energy Research Institute (KAERI) for calibrating neutron measuring devices to be used in radiation workplace monitoring consist of two kinds of neutron spectra, the direct and the scattered neutron fields, which are produced by using radionuclide neutron sources, 252Cf and 241AmBe sources. Necessary parameters for calibration such as the anisotropy factor of each neutron source and the room-scattered fraction of some neutron surveymeters in the KAERI calibration facility were determined by calculation or measurement. Spectral measurement of scattered neutron fields were performed at each reference calibration point using a Bonner Multi-sphere Spectrometer (BMS) and the dosimetric quantities for calibration also estimated from the neutron energy spectra which were unfolded using the BUNKI code.

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Voltage Regulation Method at the Power Distribution System interconnected with DSG System (분산형전원이 연계된 배전계통의 전압조정에 관한 연구)

  • Choi, Joon-Ho;Chu, Dong-Wook;Kim, Jae-Chul;Hwang, Chi-Woo
    • Proceedings of the KIEE Conference
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    • 1997.11a
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    • pp.250-252
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    • 1997
  • This paper deals with voltage regulation at the power Distribution system interconnected with DSG. Modern distribution substation adopt LDC method as the voltage regulation method to deliver suitable voltages to many customers. However, the operations of DSG interconnected with distribution system, the customers' voltage violate the permissible voltage limits. Therefore, to deliver suitable voltage to many customers at the distribution substation, an advanced voltage regulation method is required. In this paper, the on line realtime MLDC (Multiple Line Drop compensation) method, considered daedband and hysterical tap changing of the ULTC, is proposed. The result from a simulation study shows that the proposed method can be practical applications for the voltage regulation at the distribution system interconnected with DSG and unbalanced load pattern among feeders.

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A sensitivity analysis about reactive power according to the interconnection distance of wave-offshore hybrid generation system (복합발전 계통연계 시 보상장치 필요성 분석을 위한 거리에 따른 무효전력 민감성 분석)

  • Jung, Seungmin;Yoo, Yeuntae;Song, Sungyoon;Jang, Gilsoo
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.251-252
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    • 2015
  • The designed hybrid generation system (HGS) not only consider the voltage condition of grid connection point but also do reactive power support according to the transmission system operator's directions. The PCS operation plan in HGS should be supported by precise transferred quantity expectation about reactive power because the system has large physical areas and also be interconnected with grid through long transmission system. Therefore, the realistic measuring process about transferred reactive power quantity by utilizing HGS is required to consider additional compensation plan. In this paper, an reactive power transferred capability of HGS with expected parameter is analyzed, and imposed to the simulation process that is performed on EMTDC environment. Basically, grid information and system characteristics were utilized with Jeju island in Korea, and the performance analysis is carried out based on the composed layout in ongoing project.

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A Study on the Impact of the Difference between Analog/Digital Music in Music Therapy (아날로그/디지털 음원의 차이가 음악치료에 미치는 영향에 대한 연구)

  • Han, Eui-Hwan;An, Jin-Woo;Seo, Bo-Kug;Cha, Hyung-Tai
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2012.11a
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    • pp.252-253
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    • 2012
  • 최근 들어 정신적/신체적 질병을 치료하기 위해 음악을 많이 사용한다. 음악 치료의 수요가 늘어남에 따라 HCI, BCI, Music Therapy 등과 같은 음악의 성질과 생체신호간의 관계, 심리상태 변화 등에 관한 연구들이 많이 이뤄지고 있다. 또한 압축기술의 발달로 인하여 디지털 음원을 손쉽게 듣고 다닐 수 있으며, 생체 신호처리 이론, 생체 신호처리 장비 등이 발달함에 따라 디지털 음원을 이용하여 음악 치료 연구를 할 수 있게 되었다. 하지만 이러한 디지털 음원이 음악치료 측면에서는 효과가 크지 않을 뿐만 아니라 오히려 악영향을 미친다는 내용이 방송/신문을 통해 기사화 되고 있다. 따라서 본 논문에서는 동일한 음원의 아날로그/디지털 음악으로 청감테스트를 진행하고, 생체신호(혈압, 심박수, 뇌파)를 측정하여 차이점을 비교/분석한다.

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Distribution System modeling and Application for HTS Resistor type FCL (저항형 초전도 한류기를 위한 배전개통의 모델링과 적용)

  • Choi, Heung-Kwan;Yoon, Jae-Young;Kim, Jong-Yeul;Lee, Byong-Jun
    • Proceedings of the KIEE Conference
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    • 2002.11b
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    • pp.250-252
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    • 2002
  • Nowadays, one of the serious Problems in KEPCO system is the more higher fault current than the SCC(Short Circuit Capacity) of circuit breaker. There are many alternatives to reduce the increased fault current. As the superconductivity technology has been develops, the HTS-FCL(High Temperature Superconductor-Fault Current Limiter) can be a one of the attractive alternatives to solve the fault current problem. Under the this background, this paper presents distribution system EMTDC modeling and the application of EMTDC model for resistance type HTS-FCL in the developed distribution system model.

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The Chemical Constituents of Bezoar Bovis (우황 (Bezoar Bovis)의 성분연구)

  • In Kyu Kim;Sun Ku Park;Hyun Cheol Oh;Kyu Wan Kim
    • Journal of the Korean Chemical Society
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    • v.35 no.3
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    • pp.249-252
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    • 1991
  • Two new metabolites have been characterized from the methylene chloride extracts of Bezoar Bovis, a well known oriental drug : 8-octadecenoic methyl ester and cholesta-3,5-diene. Their structures were deduced from $^1$H-NMR and GC-mass spectra.

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A Study on the Electrical Properties of Semiconductive Materials with Copper Tape Shield Structure in Power Cable (전력케이블에서 동테이프 차폐 구조에 따른 반도전성 재료의 전기적 특성 연구)

  • Yang, Jong-Seok;Ryoo, Chan;Jeon, Geun-Bae;Seang, Bag-Rong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.251-252
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    • 2008
  • In this study, we have investigated electrical properties of semiconductive materials for power cable caused by copper tape shield structure. Volume resistivity of specimens was measured by volume resistivity meter after 10 minutes in the pre-heated oven of both 23 [$^{\circ}C$] and 90 [$^{\circ}C$]. From this experimental results, the volume resistivity had different properties because of PTC/NTC tendency at between 23 [$^{\circ}C$] and 90 [$^{\circ}C$].

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The Conceptual Design and Estimate Superconducting Magnetic Energy Storage Device for Improvement of Power System Stability (전력계통 안정도 향상을 위한 고온 초전도 자기 전력 저장 장치의 개념 설계 및 효용 평가)

  • Lee, S.J.;Lee, C.J.;Kim, T.J.;Ko, T.K.
    • Proceedings of the KIEE Conference
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    • 1999.07a
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    • pp.250-252
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    • 1999
  • It is certain that the power qualify will be very important at 21 century. Especially instant power shortage or power fault will occur serious problems. Accordingly stable power supplication is very technical problem. There are many way to make stable supplication as auxiliary generator, but this is long time delay complement. To solve this problem the superconducting magnetic energy storage is introduced. High Tc superconductor is more commercial.

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Text Extraction Algorithm in Complex Images using Adaptive Edge detection (복잡한 영상에서 적응적 에지검출을 이용한 텍스트 추출 알고리즘 연구)

  • Shin, Seong;Kim, Sung-Dong;Baek, Young-Hyun;Moon, Sung-Ryong
    • Proceedings of the IEEK Conference
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    • 2007.07a
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    • pp.251-252
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    • 2007
  • The thesis proposed the Text Extraction Algorithm which is a text extraction algorithm which uses the Coiflet Wavelet, YCbCr Color model and the close curve edge feature of adaptive LoG Operator in order to complement the demerit of the existing research which is weak in complexity of background, variety of light and disordered line and similarity of text and background color. This thesis is simulated with natural images which include naturally text area regardless of size, resolution and slant and so on of image. And the proposed algorithm is confirmed to an excellent by compared with an existing extraction algorithm in same image.

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