• 한국지반공학회지:지반
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• 제7권2호
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• pp.51-66
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• 1991

자연사면의 안정성해석에 있어서, 뿌리는 보강재로써의 역할을 행함이 인식 되어져 왔다. 자연사 면의 잠정적 인 파괴면을 관통하는 뿌리의 인장강도에 의 해 발생하는 흙의 전단저 항의 증가량을 예측하기 위하여 본 연구에서는 흙과 뿌리의 새로운 상호작용 모델을 제안하였다. 이를 위하여 첫째로, 수과 뿌리의 합성체에 대해 실내실험과 현장실험을 실시하고 본 실험의 결과와 기존의 흙과 뿌리의 상호작용 이론적 모델과 비교 검토하여 수정 된 구과 뿌리의 상호작용 모델을 제안하였다. 이와 아울 러, 뿌리의 무작위한 분포 및 강도특성을 고려한, 통계적인 이론에 바탕을 둔 확률론적 뿌리보강 모델을 제안하였다. 끝으로, 자연사면의 안정에 미치는 뿌리보강의 효과를 알아보기 위하여 간단한 3차원 사면 안정성해석을 수행한 결과, 자연사면에서의 뿌리보강은 깊은 파괴보다는 얇은 파괴에 대 해 중대한 영향을 미침을 알 수 있었다.

• Journal of Ginseng Research
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• 제21권2호
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• pp.91-97
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• 1997

In order to elucidate the mechanism of red-colored phenomena(RCP) in ginseng(Panax ginseng C.A. Meyer), distribution of inorganic elements of ginseng root and its surrounding soil, and microflora in the soil were investigated. Red brown colored-substances were accumulated in the cell wall of epidermis at early stage of red-colored ginseng (RCG). Cell wall of the late stage of RCG was disordered and microorganisms were shown in the disordered cell wall. Al, Si and Fe contents among inorpanic elements in the epidermis of RCG were higher at two or three times than that of healthy ginseng. On the other hand, K content was higher at three times in healthy ginseng than that of RCG. Especially, Fe content was higher at three times in lateral roots of RCG than that of healthy ginseng. Total 21 strains of microorganisms were isolated on the 523 medium from surface soil, surrounding soil of both healthy and RCG, and RCG. Six strains of microorganisms among them were resistant to 2 mM Fe. Two species in Bacillus app. and Lactobacillus app. , and one species in Micrococcus sp. and Npisseria sp. respectively were identified. It seemed that RCP was closely related with the distribution and uptake of inorganic elements, was also correlated Fe-independent metabolism of microorganisms.

• 대한전기학회논문지
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• 제37권10호
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• pp.694-701
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• 1988

분포형 레일건은 전기자가 이동하는 공안 전기자전류를 거의 일정하게 유지할수 있으며 전류공급영성과 전기자 사이의 거리를 최소로 유지할수 있게 한다. 이 논문은 분포형 레일건에서 전류분포실효저항 및 전류의 실효확산 깊이에 영향을 미치는 인자를 규명한 것이다. 정상상태의 간단한 2차원 모델로 부터 레일의 전류분포와 실효저항을 나타내는 식을 유도하였다. 전류의 확산이 불충분한 조건에서 레일의 실효저항은 레일의 상대속도, 투자솔, 전기자와 전류공급영성과의 거리의 1/2승에 비례하고 도전솔의 1/2승에 반비례하였으며, 전류의 실효확산 깊이는 전기자와 전류공급영성과의 거리의 1/2승에 비례하고 투자솔, 도전솔 및 속도의 1/2승에 반비례하였다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2011년도 춘계학술발표대회
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• pp.572-575
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• 2011

It is well known that spanning tree protocol (STP) is the most commonly used protocol in switching networks for smart grid. STP selectively blocks redundancy links of the network to prevent layer 2 loops in network, and it also has a functionality of backing up links. As with the other protocols, STP has been updated with the continuing development of the network. STP is a broad concept and it does not just refer in particular to defined STP protocol in IEEE 802.1D standards, it refers to updated spanning tree protocol based on STP. Because of uneven distribution of communication traffic in root bridge, STP cannot satisfy fast converge nce while the failure occurs near the root bridge or on the root bridge in tree topologies of STP. In this paper, we propose a novel method --- Hyper Cube Spanning Tree Protocol (HCSTP) to solve uneven distribution of communication traffic. Theoretically, hyper cube in our protocol increases throughput and improves the utilization of communication. The simulation results show that HCSTP can achieve comparative and considerably higher performance than other STP protocols in terms of reconnection.

• 환경생물
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• 제41권4호
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• pp.657-665
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• 2023

The root-lesion nematode Pratylenchus spp. is the most important plantparasitic nematode due to its worldwide distribution, wide host ranges, and migratory endoparasitic characteristics. One population of Pratylenchus collected from the giant pussy willow (Salix chaenomeloides Kimura) in the Andong area as part of a nematode survey in Korea was characterized morphologically and by molecular methods. The analysis of morphological measurements and morphometric characteristics, as well as DNA sequencing of the rRNA large subunit (LSU) D2/D3 expansion segments and the internal transcribed spacer (ITS) gene sequence, confirmed the identity of this population as P. hippeastri. This study is the first report of P. hippeastri associated with Salix chaenomeloides in Korea and worldwide. Further studies on distribution and pathogenicity in different P. hippeastri host crops, such as grapevines, strawberries, and apples, are necessary. The taxonomic keys to 16 Pratylenchus species in Korea are provided.

• Journal of applied mathematics & informatics
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• 제5권2호
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• pp.465-474
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• 1998

Results on the analytic behavior to the limiting spectral distribution of matrices of sample convariance type. studied in Marcenko and Pastur [2] are derived. using the Stieltjes transform it is shown that the limiting distrbution has a continuous derivative away from zero the derivative being analytic whenever it is positive and the behavior of it resembles the behavior of a square root function near the boundary of its support.

• Journal of applied mathematics & informatics
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• 제16권1_2호
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• pp.483-488
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• 2004

Results on the analytic behavior of the limiting spectral distribution of large dimensional random matrices, studied in Marcenko and Pastur [2], are derived. Using the Stieltjes transform, it is shown that the limiting distribution has a continuous derivative away from zero, the derivative being analytic whenever it is positive [3]. In the present paper, it is derived that the behavior of it resembles the behavior of a square root function near the boundary of its support.

• Journal of the Korean Statistical Society
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• 제33권2호
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• pp.149-157
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• 2004

The stationarity is one of the most important properties of a time series. We propose robust sign tests for seasonal autoregressive processes to determine whether or not a time series is stationary. The proposed tests are robust to the outliers and the heteroscedastic errors, and they have an exact binomial null distribution regardless of the period of seasonality and types of median adjustments. A Monte-Carlo simulation shows that the sign test is locally more powerful than the tests based on ordinary least squares estimator (OLSE) for heavy-tailed and/or heteroscedastic error distributions.

• 한국통계학회:학술대회논문집
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• 한국통계학회 2003년도 춘계 학술발표회 논문집
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• pp.281-286
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• 2003

The stationarity is one of the most important properties of a time series. We propose robust sign tests for seasonal autoregressive process to determine whether or not a time series is stationary. The tests have an exact binomial null distribution and are robust to the outliers and the heteroscedastic errors. Monte-Carlo simulation shows that the sign test is locally more powerful than the OLSE-based tests for heavy-tailed and/or heteroscedastic error distributions.

• 열병합발전
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• 통권30호
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• pp.21-25
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• 2002

According to recent Korea Electric Power Company report, yearly distribution line brass cramp bolts failure summed up to 4,400 cases emerging as one of main local break-down causes. Naturally, the need for the investigation was proposed To determine the root cause of the cramp bolt failures, mechanical and metallurgical investigation were performed for 90 samples which collected from various sites. For the understanding of the geometric characteristics, stress distribution was evaluated by CAE program and proof load of each bolts was tested. The SEM&EDS was used for metallurgical investigation. Through the investigation, the root causes of failures were confirmed. All damaged bolts showed intergrannular fracture mode and the all fractured bolt showed ß phase morphology contrast to the a&ß mixture morphology of the non-damaged samples. Additionally, EDS analysis confirmed the existence of lead rich layer on grain boundaries.