• Journal of applied mathematics & informatics
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• 제8권2호
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• pp.519-530
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• 2001

A two commodity continuous review inventory system with independent Poisson processes for the demands is considered in this paper. The maximum inventory level for the i-th commodity fixed as $S_i$(i = 1,2). The net inventory level at time t for the i-th commodity is denoted by $I_i(t),\;i\;=\;1,2$. If the total net inventory level $I(t)\;=\;I_1(t)+I_2(t)$ drops to a prefixed level s $[{\leq}\;\frac{({S_1}-2}{2}\;or\;\frac{({S_2}-2}{2}]$, an order will be placed for $(S_{i}-s)$ units of i-th commodity(i=1,2). The probability distribution for inventory level and mean reorders and shortage rates in the steady state are computed. Numerical illustrations of the results are also provided.

• Journal of Photoscience
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• 제3권1호
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• pp.23-28
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• 1996

To investigate the structure and function of photosystem I, cartridge mutagenesis technique was used to inactivate the psaB gene of photosystem I. From the screen, many strains which have potential defects in photosystem I were generated. Biochemical analysis revealed that B2, one of the mutant, had a reduced amount of chlorophyll. Electron transfer activitx from photosystem II to photosystem I as oxygen uptake was the rate of 64 % of wild type. Also B2 showed a decreased photosystem I activity when measured by 77 K fluorescence emission spectrum. Particularly, immunodetection analysis showed that the B2 had reduced amount of PsaA/PsaB, but a normal range of PsaC and PsaD. Here we present a photoheterotrophic mutant for psaB gene as a unique model strain for future study of structural/functional relationship and biogenesis of photosystem I.

• 생약학회지
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• 제33권2호통권129호
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• pp.100-104
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• 2002

Sanguisorbae Radix has hemostatic, analgesic and astrigent properties and it has been used for the treatment of burns, scalds and internal hemorrhage. Ziyuglycoside I was isolated from Sanguisorbae Radix and identified by the spectroscopic methods. In order to evaluate the quality of it, quantitative determination of Ziyuglycoside I in Sanguisorbae Radix using HPLC method has been conducted. Quantitative analysis of Ziyuglycoside I showed average 3.005% in 30 samples collected throughout the regions of Korea.

• 생명과학회지
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• 제22권2호
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• pp.245-250
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• 2012

Vibrio속의 core 균주(Vibrio alginolyticus, Vibrio parahaemolyticus)를 포함하여 총 6 종의 Vibrio 균주(V. fluvialis, V. proteolyticus, V. vulnificus, V. mimicus)와 Grimontia (Vibrio) hollisae의 16S rDNA를 PCR 증폭하여 Alu I, Cfo I, Dde I, Hae III, Msp I, Rsa I의 6 종의 제한효소를 처리 후 RFLP 분석을 수행하였다. 2 종의 core 균주와 V. proteolyticus는 4 종의 제한효소(Cfo I, Dde I, Msp I, Rsa I)에서 동일한 제한효소 패턴을 나타내었다. 제한효소의 패턴의 조합에 의해 6 종의 Vibrio 종은 6 개의 RFLP type으로 구분되었다. 특히 Alu I의 경우, 실험된 6 종의 Vibrio속에 대하여 각기 다른 6 개의 종 특이적 RFLP type을 나타내었다. 제한효소 패턴에 근거하여 작성한 덴드로그램에서 Vibrio core group 균주인 V. alginolyticus 와 V. parahaemolyticus는 90% 이상의 매우 높은 유사도를 나타내었다. 반면 Grimontia hollisae는 실험된 모든 제한효소 패턴에서 Vibrio속 세균과는 분명히 구분되는 RFLP type을 나타내었다. 따라서 PCR-RFLP는 제한효소를 적절히 선택한다면 Vibrio 속 세균의 신속한 구분에 여전히 유용하다.

• Journal of the Korean Wood Science and Technology
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• 제31권6호
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• pp.1-7
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• 2003

The phase transformation from cellulose I into cellulose II in woods by way of Na-cellulose I was examined by x-ray diffraction analysis.The formation of Na-cellulose I in woods increased with the increase of treating time in alkali solution. When compression wood was treated with 20% NaOH solution at room temperature for 1 day, the x-ray diagram showed only Na-cellulose I. On the other hand, the x-ray diagram of tension wood showed a mixture of cellulose I and Na-cellulose I. Cellulose I of tension wood could not be transformed completely into Na-cellulose I even after 10-day treatment, but was transformed into Na-cellulose I after 30-day treatment. Na-cellulose I of compression and tension woods was converted to the cellulose I pattern and the mixture of cellulose I and cellulose II, respectively, after washing with water and drying at 20℃. Cellulose I regenerated from Na-cellulose I in wood could not be converted to cellulose II by delignification. Thus, it revealed that the delignification of the alkali-treated wood did not affect their cellulose structures. From the results, therefore, it can be concluded that lignin in woods prevents the formation of the stable Na-cellulose I and the conversion from cellulose I to cellulose II. This means that the conversion of chain polarity of wood cellulose hardly occurs during mercerization because cellulose microfibrils are fixed by lignin which not to be intermingled.

• 한국자동차공학회논문집
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• 제18권3호
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• pp.104-109
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• 2010

The fatality of pedestrian accounts for about 21.2% of all fatality at 2007 year in Korea. In car to pedestrian accident it is very important to inspect the throw distance of pedestrian after collision for exact reconstructing of the accident. The variables that influence on the throw distance of pedestrian can be classified into the factors of vehicle and pedestrian, and road condition. It was simulated by PC-CRASH, a kinetic analysis program for a traffic accident in sedan type vehicle and SPSS program was used for regression analysis. From the results, the throw distance of pedestrian increased with the increasing of vehicle velocity, and decreased with the increasing of impact offset. Also it decreased with the increasing of velocity of pedestrian at accident, and throw distance at the road condition of wet was longer than that at dry condition. Finally, the regression model of sedan type vehicle on the throw distance of pedestrian was as follows; $$dist_i=2.39-0.11offset_i+0.59speed_i-545height_i-0.25walk_i+2.78wet_i+{\epsilon}_i$$.

• 동력기계공학회지
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• 제13권5호
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• pp.76-81
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• 2009

The fatalities of pedestrian account for about 21.2% of all fatalities at 2007 year in Korea. To reconstruct exactly the accident, it is important to calculate the throw distance of pedestrian in car to pedestrian accident. The frontal shape of SUV vehicle is dissimilar to passenger car and bus, so the trajectory and throw distance of pedestrian by SUV vehicle is not the same of passenger car and bus. The influencing on it can be classified into the factors of vehicle and pedestrian, and road factor. It was analyzed by PC-CRASH for simulation, and SPSS s/w was used for regression analysis. From the simulation results, the maximum impact energy of multi-body of pedestrian was occurred to that of torso body at the same time. And the throw distance increased with the increasing of impact velocity, and decreased with the increasing of impact offset. Also it decreased with the increasing of velocity of pedestrian at accident, and the throw distance of wet road was longer than that of dry road. Finally, the regression analysis model of SUV(Nissan Pathfinder type)vehicle in car to pedestrian accident was as follows; $$disti_i=-0.87-0.11offseti_i+0.69speed_i-4.27height_i+0.004walk_i+0.63wet_i+{\epsilon}_i$$.

• 항공우주기술
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• 제10권2호
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• pp.133-145
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• 2011

본 논문은 2008년 8월초부터 2010년 6월 10일 KSLV-I 2차 발사까지 수행된 나로우주센터의 추진제 및 고압가스 품질 관리 결과를 정리한 것이다. 품질관리는 나로우주센터에서 사용되는 모든 고압가스(Air, GHe, $GN_2$) 및 액화가스(LOX, $LN_2$)를 대상으로 관련 발사대 및 조립동 모든 장비에 대해 자율시험(AT), 인증시험(QT), 비행시험(FT) 모든 단계에서 수행하였다. 결과로써 총 428회의 간이검사(check analysis), 111회의 전항목검사(full analysis)를 수행하였다.

• Steel and Composite Structures
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• 제18권4호
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• pp.873-887
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• 2015

The continuous composite I-girder should have a sufficient rotation capacity (or ductility) to redistribute the negative bending moment into an adjacent positive bending moment region. However, it is generally known that the ductility of the high strength steel is smaller than that of conventional steel, and application of high strength steel can cause ductility problems in a negative moment region of the I-girder. In this study, moment redistribution of the continuous composite I-girder with high strength steel was studied, where high strength steel with yield stress of 690 MPa was considered (the ultimate stress of the steel was 800 MPa). The available and required rotation capacity of the continuous composite I-girder with high strength steel was firstly derived based on the stress-strain curve of high strength steel and plastic analysis, respectively. A large scale test and a series of non-linear finite element analysis for the continuous composite I-girder with high strength steel were then conducted to examine the effectiveness of proposed models and to investigate the effect of high strength steel on the inelastic behavior of the negative bending moment region of the continuous composite I-girder with high strength steel. Finally, it can be found that the proposed equations provided good estimation of the requited and available rotation capacity of the continuous composite I-girder with high strength steel.

• 한국환경교육학회지:환경교육
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• 제20권2호
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• pp.16-24
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• 2007

The purpose of this study is to understand how the unit objectives and contents associated with environment are reflected on the 6 kinds of chemistry- I textbooks in the 7th curriculum and to present how to deal with the environmental education in chemistry- I. The results of this study are as follows. First, units associated with environment account for an average of 43.7% on chemistry- I in 7th curriculum. Second, contents of units related to environmental education on chemistry- I in 7th curriculum are environmental pollution(17.8%), environmental preservation and environmental pollution prevention(15.9%), environmental hygiene(12.2%), and any other things, Environmental pollution takes up a considerable part of environmental education. Third, the results for analyzing the objectives of chemistry- I in 7th curriculum show that Information Knowledge Awareness(34.0%) and Skill (29.9%) take up most parts. Fourth, Orientation (I) as analysis standard for objective of the units related to environmental education accounts for 10.2% of the total. It is clear that environmental education is carried out from STS point of view. In conclusion, environmental education in Chemistry- I focuses on fostering students' ability to apply the fundamental notion of chemistry to real life associated with environments. Therefore, it is necessary that environmental education in Chemistry- I should include value, attitude and participation and that improve students' ability to approach the environmental problem comprehensively.