• Tunnel and Underground Space
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• v.13 no.2
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• pp.117-124
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• 2003

The fracture processes under static tensile loading were simulated using a proposed numerical simulation method, based on finite element method and fracture mechanism, and analyzed to verify an influence of rock inhomogeneity on static tensile strength. Static tensile strengths for the specimen models with different spatial microscopic tensile strength when m=5 and m=50 were estimated. These analyses revealed that the static tensile strength becomes closer to the mean microscopic tensile strength at a higher uniformity coefficient and the scatter of the strength data decreases in increasing the uniformity coefficients. Therefore, it could be concluded that rock inhomogeneity has an effect on static tensile strength.

• Journal of Soil and Groundwater Environment
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• v.10 no.3
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• pp.24-31
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• 2005

This study presents a contaminant transport model suitable for a 2-dimensional heterogeneous aquifer with multiple contaminant sources. It uses a streamline simulation, which transforms a multi-dimensional problem into multiple 1dimensional problems. It runs flow simulation, streamline tracking, and calculation of contaminant concentrations by turns. The model is verificated with a Visual MODFLOW by comparing contaminant concentration distributions and breakthrough curves at an observation well. Due to its fast simulation, it can be applied to time consuming simulations such as in a fine-grided aquifer, an inverse modeling and other applications.

• Journal of the Korean Data and Information Science Society
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• v.11 no.2
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• pp.247-255
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• 2000

Usually, partailly balanced incomplete block design have been used a parametric design that make blocks of complete diallel cross. For that we use triangular PBIBD as parametric design, we have to find triangular PBIBD with corresponding parameters. Using the theorem that dual design of balanced incomplete block design with special parameters becomes triangular PBIBD, we can design block complete diallel cross without finding new triangular PBIBD. In this paper, we provided the plan and design satisfying such block complete diallel crosses.

• The Korean Journal of Zoology
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• v.35 no.2
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• pp.211-218
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• 1992

한국산 노랑초파리 군에 속하는 8종의 유전적 유연관계를 밝히고자 생식적 격리 그리고 수용성 단백질을 전기영동법으로 분석하였다. 생리적 격리 실험에서 교배전격리 실험결과를 Watanane와 Kawanishi model에 근거하여 보면 D. aurario complex 3종 중 D. triauror물가 원시종이며 남 auraria는 팍생종으로 나타났다. 교배후 격리 실험에서 나. melonogaster와 D. simuions의 교배시, D. melonogoster를 수컷으로 하였을 때는 불임의 수컷만이, 또 D. melonogaster를 암컷으로 곯였을 때는 불임의 암컷만이 출현하였다. 그리고 남 ouraria complex 3종간의 교배에서는 수정 능력이 있는 수컷과 암컷이 출현하였는데, 이는 아직 남 auraria Complex가 semispecies단계에 있음을 나타내는 것이라 할 수 있다. SDS-PAGE로 분석한 노랑초파리 군 8종의 band pattern을 densitometer로 scanning한 결과 남 susu상가 가장 특이하였으며, TDE에 의한 유전적 거리(Aquadro and Avise's)는 남 auror지와 봉 triauror지사이가 0.155로 가장 낮았고, D. melonogaster와 고. mfa 사이가 0.422로 가장 높았다. 본 연구의 결과를 UPGMA법 뜨로 분석하면, 한국산 노랑초파리 군 8종은 4개의 아군으로 나뉘어지며 이들은 2개의 다른 큰무리로 구분되었는데, D. suzu가기 아군, D. lutescens의 아군, D. melanogoster와 봉 simulons의 아군이 속한 큰무리와, D. mfa,0. ouroria, D. biauroria 그리고 남 triourario가 속한 다른 큰무리로 나눌 수 있다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.6
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• pp.575-580
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• 1986

Triploid rainbow trout (Salmo gairdneri) were produced on a large scale practice by the application of moderate heat treatment in 1986. Triploid treatment of the fertilized eggs was carried out with heat shock at $27^{\circ}C$ for 10 to 14 minutes starting 10 minutes after insemination at $10^{\circ}C$. Estimated triploidy ranged from $45\%\;to\;57\%$ ana the incidence of triploidy slightly increased with the treatment time. No significant differences of growth rate were observed between triploidy and diploidy at the early stage of growth. This observation was consistent with results of other fish species and other reports on this species. This heat shock technique, expecting further improvement, should be useful in the mass production of sterile triploid rainbow trout.

• Journal of the Korean Data and Information Science Society
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• v.27 no.1
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• pp.9-18
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• 2016

In the Heckman-Meyers model, which is frequently referred by IAA, Swiss Solvency Test, EU Solvency II, the assumption of parameter distribution is key factor. While in theory Bayesian analysis somewhat reflects parameter uncertainty using prior distribution, it is often the case where both Heckman-Meyers and Bayesian are necessary to better manage the parameter uncertainty. Therefore, this paper proposes the use of Bayesian H-M CRM, a combination of Heckman-Meyers model and Bayesian, and analyzes its efficiency.

• Journal of the Korean GEO-environmental Society
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• v.13 no.6
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• pp.41-50
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• 2012

In general, it is critical that grout consistency permit the complete filling of void space without segregation of ingredients. Recently, the antiwashout agent is used on underwater grout materials for preventing the grout from the segregation in water. This study introduces a new type of antiwashout underwater and flowable grout material using viscous modifiers and its characteristics comparing with conventional grout materials in fresh and sea water. It is found that the antiwashout underwater grout both in fresh and sea water has enough strength and good resistance to segregation.

• Magazine of the Korea Concrete Institute
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• v.8 no.5
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• pp.179-187
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• 1996

Many underwater concrete structures have been constructed recently in proportion to the increase of ocean developments. The research for the underwater concrete construction was mainly focused in view of placing method. Recently, special admixture agents of concrete were developed for antiwashout concrete under water in some foreign nations. They had successful results in experiments and site constructions. However. there are seldom experimental results or placements in domestic contry. In this paper. We had carried out property tests of fresh and hardened concrete with refer to successful results in experiments and site construction and investigated the physical variation of the antiwashout underwater concrete considering the interaction between antiwashout admixture and other ones. We have decided the optimal mix proportion fb;r antiwashout underwater concrete under standerd sea state.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.744-744
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• 2012

불투수층은 자연적인 침투를 허용하지 않는 인위적인 토지피복상태로 도시화율 추정 및 유역의 환경변화 정도를 분석하기 위한 척도로 사용되어 왔다. 특히, 수문학적 관점에서 불투수층은 단기 유출현상에 큰 영향을 끼치는 요소로 불투수율이 증가할수록 침투량이 감소하여 첨두유출량은 증가하고 도달시간은 짧아진다. 최근에는 급속한 도시화로 인해 불투수층의 영향이 더욱 커짐에 따라 불투수율의 추정에 대한 필요성이 증가하고 있다. 현재까지 위성영상을 이용한 불투수층의 추정은 고해상도 영상을 이용하여 피복분류를 수행하였다. 즉, 분류된 토지피복에 근거하여 불투수율을 산술적으로 계산하거나 분광혼합기법 및 회귀 트리기법 등 다양한 방법에 적용되어 왔다. 본 연구에서는 Sub-pixel 분류기법을 위성영상에 적용하여 섬강유역의 불투수율을 추정하고자 한다. Sub-pixel 분류는 기존 분류기법들이 다양한 토지피복이 혼합된 화소에 대해서도 가장 비중이 높은 토지피복 하나로 분류하던 것을 개선한 방법으로 fuzzy 이론을 적용하여 최소 20% 이상의 비율을 점유하는 항목 모두를 구분하여 분류하는 기법이다. 이를 위해 섬강유역의 Landsat TM 영상을 수집하고 환경부의 토지피복도와 지질도를 참조하여 트레이닝 자료를 수집하였다. 또한 결과에 영향을 미칠 수 있는 구름은 전처리를 통하여 제거하고 수집된 트레이닝 자료에 Sub-pixel 분류기법을 적용하여 섬강유역의 불투수율을 공간분포도로 작성하였다.

• Journal of The Geomorphological Association of Korea
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• v.18 no.3
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• pp.83-92
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• 2011

The properties and changes of geomorphic relief and coastal deposits were analyzed at Goreabul sand beach in Yeongdeok-gun, the largest that in east coast of Kyungsangbuk-do Province. As the result of grain size analysis, in almost season except summer, the sands mainly deposited in Goraebul sand beach because longshore current drift northward contrary to Gangwon-do east coast, and summer longshore current is weak or change direction to south ward. Sand beach mostly came form erosion owing to typoon and storm and was deposit more coarse sand in the summer, and was produced deposition actively in the fall and winter. Front side of sand dune came from deposition on sand every season by sea breeze, especially in the winter.