• Journal of the Korea Concrete Institute
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• v.13 no.4
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• pp.397-405
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• 2001

In clod weather regions, a strong seasonal wind brings sea salts to the land. In addition to it, recently, the spreading amount of deicing salts has increased numerously for purpose of removing snow and ice. Thus the salts environment around concrete structures becomes so severe that various damages of concrete due to applied salts will be brought up. Much of countries such as America, Europe etc. is carried out study for effects of deicing salts on concrete. However, there are not test methods for deterioration of concrete subjected to both freezing-thawing and chloride in Korea. In this study, we carried out test for the compound deterioration subjected to both freezing-thawing and chloride attack, to investigate the effects of sodium chloride on the deterioration of concrete. The test was performed to investigate the effects of cement type, strength and air content on the scaling deterioration of concrete. As a result, the scaling deterioration was accelerated in the presence of salts. And the resistance to scaling was strongly influenced by the type of cement, the strength and air content of concrete.

• Journal of the Korean Ceramic Society
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• v.35 no.11
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• pp.1155-1161
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• 1998

We have studyed the surface electric resistiance for inner conductive film consisted of graphite and iron oxide by coating the conductive paint on inner face of 28" wide CRT funnel and have evaluated the working properties of 28" wide CRT according to the surface electric resistiance. We found that the viscosity of paint and the thickness of conductive film became the higher but the surface electric resistiance of con-ductive films was the lower than before in accordance with the increase of solid contents in conductive paint and that the surface condition and the surface electric resistiance of conductive films changed highly ac-cording to the drying conditions also. From these results we could get the uniform thickness and the un-iform film resistance and the optimum working property of selectric propertise in CRT when we used the conductive paint with solid contents 28% and viscosity about 13cps.

• Journal of the Korean Data and Information Science Society
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• v.23 no.4
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• pp.677-682
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• 2012

There are lots of sampling design which is determined for sample survey in various fields. Especially, it is important problem for clinical data because basic characteristic variables by group which consist of experiment group and control group in population should be reflect to sample. Therefore, frequencies, center scales and dispersion scales of variables by group in population should be similar in sample. But usual sampling design is very complicate so it is difficult to use in practice for researcher. In this paper, we consider the sampling method using simulation. We applied the proposed method to colon cancer data from a hospital. We compare basic characteristic variables between population and sample with mean, frequency and statistic hypothesis test.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.6
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• pp.767-773
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• 2017

Infrared stealth is an important technology for naval ships. This technology helps improve the anti-detection performance and survivability of naval ships. In general, the infrared signature of naval ships are categorized into internal and external heat source. External signature are generated by ship surface heating by solar flux as well as the complicated heat transfer process with the surrounding weather condition. Modern naval ships are equipped with seawater injection nozzles on the outside for nuclear, biological and, chemical, and these nozzles are used to control external signature. Wide nozzle placement intervals and insufficient injection pressure, however, have reduced seawater dispersion area. To address this problem, nozzle installation standards must be established. In this study, an actual-scale experimental system was implemented to provide the evidence for nozzle installation standards in order to reduce the infrared signature of naval ships. In addition, the environmental conditions of the experiment were set up through computational fluid dynamics considering the ocean climate data and naval ship management conditions of South Korea. The dispersion distance was measured using a high-resolution thermography system. The flow rate, pipe pressure, and dispersion distance were analyzed, and the evidence for the installation of seawater injection nozzles and operation performance standards was suggested.

• The Korean Journal of Quaternary Research
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• v.25 no.1
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• pp.41-49
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• 2011

Archaeological survey has been carried out to find some evidence of human occupation in 31 caves in Pyeoungchang, Danyang, Jincheon, Goesan, Munkyoung, Boeun, Sangju in central limestone area of the Korean peninsula. Among those caves, some archaeological evidences were observed in 11 caves. Various types of potteries, animal bones and stone artifacts were collected on surface of sediments in caves. Among them, the Mosan cave in Munkyoung and the Kwangcheonseongul in Pyeoungchang are very likely to yield important archaeological remains in the well preserved deposits in the caves. Further researches are expected to provide significant information for explaining human living from prehistoric time to historical periods.

• Environmental and Resource Economics Review
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• v.27 no.3
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• pp.545-567
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• 2018

This study applied and compared Poisson model, negative binomial model, zero inflated Poisson model, and zero inflated negative binomial model to estimate determinants of employed labour quantity. To estimate each of models, this study used fisheries census data which were obtained at microdata integrated service running by Statistics Korea. The study selected zero inflated negative binomial model according to the Vuong test and Likelihood-ratio test. In addition, the study estimated fishing village's practical changes on employed labour quantity as analyzing changes from 2010 to 2015. The results showed that the household with fishing vessels and high selling price had a significant effect on decrease of the labour quantities. Meanwhile, the longer work experience of the household, the more significant the increase in the labour quantities. In conclusion, this study presented that capitalized fishing household and the acceleration of aging had a significant impact on the change in the labour quantities.

• The KIPS Transactions:PartB
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• v.13B no.2 s.105
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• pp.121-126
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• 2006

In this paper, we propose an approach to increase the power of clustering Web images by using high-level semantic features from text information relevant to Web images as well as low-level visual features of image itself. These high-level text features can be obtained from image URLs and file names, page titles, hyperlinks, and surrounding text. As a clustering engine, self-organizing map (SOM) proposed by Kohonen is used. In the SOM-based clustering using high-level text features and low-level visual features, the 200 images from 10 categories are divided in some suitable clusters effectively. For the evaluation of clustering powers, we propose simple but novel measures indicating the degrees of scattering images from the same category, and degrees of accumulation of the same category images. From the experiment results, we find that the high-level text features are more useful in SOM-based Web image clustering.

• The Korean Journal of Applied Statistics
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• v.28 no.2
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• pp.231-239
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• 2015

A Poisson model is the first choice for counts data. Quasi Poisson or negative binomial models are usually used in cases of over (or under) dispersed data. However, these models might be unsuitable if the data consist of excessive number of zeros (zero inflated data). For zero inflated counts data, Zero Inflated Poisson (ZIP) or Zero Inflated Negative Binomial (ZINB) models are recommended to address the issue. In this paper, we further considered a situation where zero inflated data are spatially correlated. A mixed effect model with random effects that account for spatial autocorrelation is used to fit the data.

• Journal of Sericultural and Entomological Science
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• v.1
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• pp.15-21
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• 1960

4231년 농림부산림국에서 송충구제책으로 경기도 임업시험장에서 인공배양한 No.7호균외 수종을 사용할 계획인바 비에 대한 임업시험장 시험보고에 의하면 핵균은 송충에 대하여 맹독성이지마는 잠아에 대하여서는 기독성이 경미하다는 보고 이였으므로 양잠가에 대한 의문을 풀기 위하여 송충 및 잠아에 대한 전염성의 강약을 비교 시험하여 그 독성정도를 구명코저 함. 1. 경기도 임업시험장 연구보고 제1호에 기재된 No.7 호균의 시험성적과 본시험성적과를 대조하면 그 이병률은 일정한 경향을 표시치 않으며 다소 상치된 결과이었다. 즉 별표에 의하면 송충은 72~100% 잠아에 있어서는 4289년도에 0~2% 4290년도이 0~20%였으나 본시험결과 (표 1,2,3)는 송충은 표준구에 6.6% 처리구에 13.3~20%이고 잠아는 5~50%의 이병률이였다. 따라서 송충에는 그 감염도가 높으며 잠아는 그 감염도자 낮다고하는 근거를 인정키 난하다. 2. 본시험에 공시된 접종균 No.7호균은 경기도 임업시험장에서 호칭하는 황황강균(Insarica farinosa)이 었으나 핵균 배양시에 이균이 침입된 관계인지는 모르나 본시험에서 폐사를 검정한 결과 백강균(Botrytis Bassiana)이였다. 따라서 No.7호균에 대한 순도가 의심되며 시험결과의 정확을 기할수가없었다. 3. 경기도 임업시험장연구보고 제1호에 접수된 양년간시검성적에 의하면 경화병균 28종중 가장 이병률이 낮다고하는 No.7호균이 본시험결과에서 잠아에 5~50%의 이병률을 나타내는것으로 보아 소위 경기도 임업시험장에서 순수분리한 균은 어느것이라도 송충에 접종하여 산지에 산포하면 그 균이 중간기생 (인교목, 직교목)을 통하여 야생화되어서 더욱 잠아에 대한 전염력을 강렬하게됨으로 양잠상 위험할것이다. 일본의 소산씨 문헌(경기도 임업시험장도서관)에 의하면 야생혼충에서 전염되는 경화병균의 독성은 잠아에 대하여 강력하다는 점과 $\ulcorner$잠업지조선$\lrcorner$제11호에 전라남도 원잠종제조소 강본태대랑씨의 시험성적(참고문헌)이 이를 여실히 입증하는 바이다. (중략)

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.77-81
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• 2019

식생전이에 따른 기간분리는 해외 및 국내 논문에서 식생영향을 받지 않는 곡선식과의 차이를 검토하고, 측정성과별 분류를 통해 곡선식을 개발하는 방법이 제시하고 있으나 적용기간 설정에 대한 구체적인 방법이 없다. 또한 상하류 비교를 통해 기간분리의 적정성을 검토할 수 있다고 명시되어 있으나 비교 관측소가 없는 경우 검토에 어려움이 있다. 본 연구는 2017년 수위-유량관계곡선식의 적용시간 결정에서 현장 식생모니터링 자료와 함께 연간 수온변화를 참고 자료로 활용하였다. 연간 수온자료를 산정하기 위해 측정된 수온과 해당 기온에 대한 상관관계식을 개발하였다. 또한 산포가 발생하는 측정성과는 생성된 연간 수온자료를 참고하여 전이여부를 판단하였다. 2018년은 2017년의 계절별 수온변화 자료 및 수집된 주요 수중식생의 생활사를 참고하여 연간 측정계획에 활용하였으며, 수위-유량관계곡선식 개발 시 동일한 방법을 사용하였다. 2017년은 가뭄으로 인해 수중식생에 의한 전이가 활발했던 기간으로 측정성과에 대해 식생영향 최고 기간과 최대 기간의 동일수위에 대해서 유량을 비교한 결과 $0.003m^3/s{\sim}1.099m^3/s$의 범위를 보였다. 유출량 비교의 경우 기간분리를 적용하지 않았을 경우 약 40.1% 과대 산정되었다. 2018년은 잦은 강우로 인해 수중식생의 이탈 및 전이 영향수위의 발생빈도가 비교적 적어 동 수위 유량을 비교한 결과 $0.19m^3/s{\sim}0.49m^3/s$의 범위를 보였다. 연 유출량을 비교한 결과, 기간분리를 고려하지 않은 경우가 약 39.6%로 과소 산정되었다. 따라서 본 연구사례를 통해 식생에 의한 기간분리가 발생하는 지점에 대해서 비교적 합리적인 측정주기 계획을 위한 확립 근거와 기간분리 적용기간에 대한 합리적인 자료로 활용 될 수 있을 것이다.