• Title/Summary/Keyword: EGM

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An Approximated Reasoning with Compensation

  • Kim, Chang-Suk;Kim, Dae-Su
    • Journal of the Korean Institute of Intelligent Systems
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    • v.11 no.6
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    • pp.558-562
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    • 2001
  • In this paper, a fuzzy hyperresolution principle called CFHR. Compensatory Fuzzy Hyperresolution, with positive compensation facility is proposed. Usually hyperresolution has several terms of conditon parts. Theser terms have to be connected by the an connective. If the main/max operator to be used the and operation, there is some dependency problem of the min/max operator. So , we propose a compensatory operator EGM and applied it to the CFHR, We show the CFHR does more meaningful reasoning than existing method. We also prove the completeness of CFHR.

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Evaluation of the new Earth Gravity Models with GPS-leveling data in South Korea (최신 지구중력장모델(EGMs)의 남한지역 적용 평가)

  • Lee Yong-Chang
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2006.04a
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    • pp.99-104
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    • 2006
  • The new gravity field combination models are expected to improve the knowledge of the Earth's global gravity field. This study evaluates eleven global gravity field models derived from gravimetry and altimetry surface data in a comparison with ground truth in South Korea. Geoid heights obtained from GPS and levelling in South Korea are compared with geoid heights from the models. The results show that the gravity satellites CHAMP, GRACE and LAGEOS plus gravimetry and altimetry surface data have led to an improvement in gravity field models. As expected, the new combination gravity field model which are EIGEN-CG03C and EIGEN-GL04C give better results than the predecessors widely used models(EGM96, OSU91A etc.).

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Calculations of Shielding Failure Rates According To The Hillside Angles (대지경사각을 고려한 차례실패 사고율 검토)

  • Kang, Y.W.;Kwak, J.S.
    • Proceedings of the KIEE Conference
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    • 2005.07a
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    • pp.615-617
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    • 2005
  • 대기중에 위치한 뇌운안에 전하가 떠다니는 상태에서는 구름안과 주변에 높은 전계의 전위가 발생한다. 이 전하가 축적되면 대지 방전이 발생하고 송전선로 등에 뇌격이 침입하게 된다. 뇌 방전은 수 km에 달하는 대기중에 발생하는 거대한 전기현상이지만 이 낙뢰가 전기의 흐름이라는 것은 벤자민 프랭클린의 현장 시험에 대해 최초로 증명되었다. 이러한 대기중에 발생하는 거대한 전기현상인 낙뢰가 송전선로에 침입하여 송선선로 애자련을 섬락시키는 과정은 대단히 복잡한 전자기적인 현상이다. 그것은 가스 방전 현상, 감속에 중요한 역할을 하는 전자계의 빠른 변화, 도체와 철탑에 나타나는 코로 나와 관련된 비선형 효과 및 주파수 및 전류와 관련된 대지의 임피던스 통 다양한 현상이 종합적으로 관련된다. 따라서 가공 송전선로의 낙뢰에 대한 동작특성의 평가시 낙뢰 현상의 불규칙한 특성 및 신뢰할만한 데이터의 부족에 따른 많은 불확실성이 존재한다. 이 때문에 가공 송전선로에서 낙뢰에 의한 트립(Trip) 사고수의 계산을 위해 단순화된 방법이 아주 유용하며 효과적일 수 있다. 본 논문에서는 EGM (Electrogeometric Model) 모델을 사용하여 대지경사자의 크기에 따른 차폐실패 트립 사고율의 영향을 검토하였다.

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Merging Two Regional Geoid Estimates by Using Optimal Variance Components of Type repro-BIQUUE: An Algorithmic Approach

  • SCHAFFRIN Burkhard;MAUTZ Rainer
    • Korean Journal of Geomatics
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    • v.5 no.1
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    • pp.1-6
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    • 2005
  • When merging various datasets the perennial problem of relative weighting arises. In case of two datasets an iterative algorithm has been developed recently that allows the rigorous determination of optimal variance components of type repro-BIQUUE even for large amounts of data, along with the estimation of the joint parameters. Here we shall present this new algorithm, and show its versatility in an example that will entail the merging of two regional geoid estimates (derived from EGM 96 and CHAMP) in terms of certain series expansions which have been proven previously to belong to the most efficient ones (e.g., wavelets, Hardy's multi-quadrics, etc.). Future attempts will be devoted to the sequential merging of altimeter and tide gauge data.

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The Calculation of Lightning Flashover rate of 345kV/154kV Transmission Tower (345kV 및 154kV 송전철탑의 뇌사고율 예측계산)

  • Shim, E.B.;Woo, J.W.;Kwak, J.S.;Min, B.W.;Hwang, J.I.
    • Proceedings of the KIEE Conference
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    • 2001.07a
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    • pp.452-454
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    • 2001
  • This paper described the calculation results of lightning flashover rate on the 345kV and 154kV transmission system of KEPCO. The back-flashover rate and shielding failure rate was calculated by FLASH(lightning flashover rate calculation program from IEEE) and KEPRI's own program which is based on the EGM(Electro Geometrical Model) method. The estimated lightning flashover late of 345kV transmission system of double circuit was 1.0 flash per 100km-year, and the lightning flashover rate of 154kV transmission line was 2.0 flash Per 100km-year approximately.

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The Korean Geodetic Network Adjustments for EDM Area (국가기준점 망조정에 관한 연구 - EDM 관측지역)

  • Yang, Hyo-Jin;Choi, Yun-Soo;Kwon, Jay-Hyoun;Kim, Dong-Young
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.25 no.5
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    • pp.393-398
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    • 2007
  • According to the Korean datum change to a world geodetic system, the EDM area should be readjusted to provide consistent product over the country. The data set for EDM area is extracted from the previous KTN1987 DB and checked for the moved markers in XY network adjustment which provides quality verification. Then, EDM data set for the seven areas are rebuilt for the adjustment. Since the data is still based on the old datum, the coordinates of the data are transformed by applying the coordinate transformation parameters. Here, the transformation parameters, which were determined for the conversion of 1:50,000 topographic maps by NGII, were used. For each EDM point, the geoidal height from EGM96 model is applied to obtain the ellipsoidal height based on the GRS80. The measured distance projected onto GRS80 is adjusted using BL network adjustment by fixing 2nd order or 3rd order GPS control points. The results from the readjustment show the minimum standard error of 1.37" and the maximum standard error of 2.13". Considering the measurement accuracy of EDM (1.6" corresponding to about 2cm) and GPS position for fixed points (2cm), this result is considered to be reasonable and it is good for the practical use.

Acquirement of transgenic rose plants from embryogenic calluses via Agrobacterium tumefaciens (배발생 캘러스를 이용한 아그로박테리움 매개형질전환 장미 식물체 획득)

  • Lee, Su-Young;Lee, Jung-Lim;Kim, Won-Hee;Kim, Seung-Tae;Lee, Eun-Kyung
    • Journal of Plant Biotechnology
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    • v.37 no.4
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    • pp.511-516
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    • 2010
  • The process to acquire intron-GUS gene-expressed transformants from somatic embryos (including embryogenic calli) of Rosa hybrida cv. 'Sweet Yellow' using Agrobacterium-meditated transformation method was reported in this study. Somatic embryos including embryogenic calluses were infected with Agrobacterium tumefaciens AGL1 strain (O.D = 0.7~1.6) including intron-GUS gene for 30 min, and were co-cultured for 3 days. After co-cultivation, they were cultured on embryo germination medium (EGM) supplemented with $250\;mg{\cdot}L^{-1}$ cefotaxim at $4^{\circ}C$ for 7 days. Then, transient GUS gene expression was observed. Shoots were regenerated from the shoot primodia induced from the intron-GUS gene-transferred either somatic embryos or embryogenic calli cultured on EGM supplemented with both cefotaxim $250\;mg{\cdot}L^{-1}$ and ppt $2\;mg{\cdot}L^{-1}$. Before induction of rooting from shoots cultured on shoot growing medium supplemented with both cefotaxim $250\;mg{\cdot}L^{-1}$ and ppt $2\;mg{\cdot}L^{-1}$, the shoots were cultured on multi-shoot induction medium supplemented with both cefotaxim $250\;mg{\cdot}L^{-1}$ and ppt $2\;mg{\cdot}L^{-1}$ to induce multi-shoots. When expression of the gene from a part of the multi-shoots was identified by GUS transient assay, the putative transgenic multishoots were transferred to rooting medium supplemented with cefotaxim $250\;mg{\cdot}L^{-1}$. After the formation of healthy roots, transgenic plantlets were transferred to the greenhouse after acclimatization. The expression rate of the intron-GUS gene in the multi-shoots was 100%.

Accuracy Analysis of GNSS-derived Orthometric Heights on the Leveling Loop Disconnected Area

  • Jung, Sung Chae;Kwon, Jay Hyoun;Lee, Jisun
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.36 no.1
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    • pp.1-8
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    • 2018
  • To compensate for the shortcomings of spirit leveling, research on the determination of GNSS (Global Navigation Satellite System)-derived orthometric height has been actively carried out. However, most analyses were primarily performed inland. In this study, the influences of the arrangement of control points, observation duration, and geoid model on the accuracy of the GNSS-derived orthometric height have been analyzed to suggest the proper method to apply the determination of GNSS-derived orthometric height to the leveling loop disconnected area. As a result, it was found that two known points located near the unknown points need to be fixed in the leveling loop disconnected area. Further, 3 cm level of accuracy can be achieved if the GNSS survey is performed over two days, for four hours per day. In terms of the geoid model, the latest national geoid model should be applied rather than the EGM08 (Earth Gravitational Model 2008) to minimize regional bias and increase accuracy. Future research is necessary to apply the determination of the GNSS-derived orthometric height technique as a method to connect with the islands because the vertical reference system used inland and that used for the islands in Korea are still different.

Comparative Performance Evaluation of Lightning Air Terminals by the HV Laboratory Test (고전압 모의시험을 통한 피뢰침의 성능 비교평가)

  • Lee, Jae-Bok;Myeong, Seong-Ho;Jo, Yeon-Gyu;Kim, Jeom-Sik
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.50 no.12
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    • pp.627-632
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    • 2001
  • There are claims that ESE(Early streamer emission) Air terminals offer a vastly increased zone of protection over that of traditional lightning rods by causing the emission of an upward streamer/leader that will propagate towards the tip of downward leader at an early stage in the attachment process than would occur for a simple rod in the same geometrical configurations. This paper shows the results of comparing test a particular type of ESE air terminals with a simple rod conducted in the KEH HV laboratory, which are lightning impulse voltage test, flashover direction test and corona emission current measurement. The results from this test show a completely random scattering of flashovers to the conventional and ESE air terminals under identical electrics] and geometrical conditions, and thus shows no advantage of one terminal over the other.

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A Study on Injection Condition Optimization and Deformation Improvement using Taguchi Design of Experiments (다구찌 실험계획법을 이용한 사출 조건 최적화와 변형 개선에 대한 연구)

  • Young-Tae Yu;Sung-Min Mun;Sung-Young Jun;Kyoung-A Kim
    • Design & Manufacturing
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    • v.17 no.2
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    • pp.62-69
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    • 2023
  • In this study, we conducted a study on the optimization of injection molding conditions to minimize deformation of plastic product. The charging management system housing of the vehicle was selected as the research subject. Melting temperature, cooling temperature, packing time, and packing pressure were selected as the main factors expected to affect the deformation of molded products. Each main factor was divided into 5 levels. Optimization of injection molding conditions to minimize deformation was performed using the Taguchi Method. We performed an analysis of variance (ANOVA) to identify significant factors affecting the deformation of plastic product. In order to select injection molding conditions that minimize deformation of plastic products, injection molding analysis was additionally performed for insignificant factors. We then compared the deformation of the molded part before and after optimization. As a result of comparing the injection analysis results of the basic conditions and the injection analysis results of the optimal conditions, it was confirmed that the amount of deformation after optimization was improved by about 10.9%.