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        검색결과 244

        204.
        2010.05 KCI 등재 서비스 종료(열람 제한)
        구조물의 해석, 설계, 시공, 품질관리 등을 수립할 때 토목기술자는 경제적이며 효율적인 복합재료를 사용할 수 있다. 거더, 가로보, 콘크리트 상판으로 이루어진 교량시스템은 특별직교이방성 판으로 거동한다. 이러한 경계조건을 갖는 단면을 Navier 해 형태의 해석적 해를 구하기가 매우 어렵다. 복합재료로 이루어진 교량을 설계하기위하여, 단면은 가장 경제적이면서 응력에 유리한 폼코어 형태를 채택하였고, 응력을 산출함에 있어서는 유한차분법 프로그램을 사용하였다. 응력영역은 Tasi-Wu 파괴영역 기준을 이용하였다. 본 논문에서는 치수가 증가됨에 따른 인장강도 감소율을 고려하였다. 또한 이러한 경우에 대한 수치해석을 수행하였다.
        205.
        2010.04 KCI 등재 서비스 종료(열람 제한)
        The polymorphism and the genetic relationships among 32 genetic resources of genus Nelumbo from Korea, Japan, China, USA, India, Thailand and Gabong were thoroughly investigated and extensively examined using ISSR markers. Out of 103 loci detected overall, 94 were identified to be polymorphic with a rate of 91.2%. The genetic similarity matrix revealed a wide range of variability among the 32 accessions, spanning from 0.227 to 0.833. The study findings indicate that the Nelumbo accessions have a high genetic diversity, and accordingly carry a germplasm qualifying as good genetic resources for cross breeding. According to the clustering analysis, different subspecies, N. nucifera and N. lutea, were divided into independent groups and all of the N. nucifera accessions could be classified into five categories. Compared to RAPD analysis, ISSR method showed a clearer picture of polymorphism among the accessions and exhibited a definite distinction even among the subspecies. In this respect, ISSR analysis is considered to be more effective in differentiating the accessions and subspecies of the genus Nelumbo than RAPD test.
        206.
        2010.04 KCI 등재 서비스 종료(열람 제한)
        The SSR markers were generally used to analysis the plant genetic diversity, but it have been rarely reported in case of castor bean. We constructed the microsatellite-enriched genomic library and sequenced totally 775 clones to obtain the microsatellite sequence information of the castor bean. Among the sequenced clones, one hundred fifty clones (19.3%) were redundant and four hundred twenty (67.2%) were found to contain microsatellite sequences within the remaining 625 unique clones. A total of 237 primer pairs were designed based on the sequenced microsatellite clones information and evaluated for polymorphism in ten castor bean accessions. Twenty-eight SSR markers produced reproducible polymorphic bands and were further characterized using a diverse set of 25 castor bean accessions. The majority of unique SSRs revealed dinucleotide motives (84%) on the other hand the ratio of trinucleotide motives was 15%. A microsatellite enriched library from the Ricinus communis L. was mainly consisted of [(AG), (GA)/(CT), (TC)] and [(CTT)/(AAG)] microsatellite motifs. The length of dinucleotide SSRs ranged from 4 to 50 repeats with an average 12.4, and that of trinucleotide SSRs from 4 to 56 with an average of 7.35 repeats. These newly developed microsatellite markers will be useful for breeding system and classification of Ricinus communis L.
        207.
        2009.12 KCI 등재 서비스 종료(열람 제한)
        Cowpea might have been introduced from China to Korea and cultivated for several hundred years but it has never been a staple food crop in Korea. In this study, genetic diversity of 492 Korean cowpea landrace accessions that have passport information was estimated using six SSR markers. The mean of Weir's gene diversity was 0.665 from all accessions investigated in the study. Cowpea gene diversity of six local provinces in Korea was ranged from 0.370 in accessions of Gangwon to 0.680 in Jeonra provinces. Low gene diversity of the cowpea genepool of Gangwon province was probably derived from relatively few introductions. Especially SSR markers VM36 and VM39 seem to be good markers to distinguish the Gangwon accessions from others by occurring at a specific locus with higher than 78% of allele frequency. Except for the Gangwon province with the low genetic diversity, gene diversity of cowpea accessions from other provinces was ranged from 0.600 to 0.680 indicating no big differences among provinces. Distribution pattern of the allele frequencies was similar among the other provinces. This may reveal that Korean farmers might exchange cowpea seeds easily with even their neighbors with geographical barriers. A core collection, 100 landraces, ca. 20% of base collection, was developed at the 70% of a similarity coefficient level using random sampling approaches after stratification of the entire landrace collection based on the phenetic dendrogram. The variability of SSR in the base and core collections of Korean cowpea landrace was compared by calculating Weir's gene diversity. The mean of Weir's gene diversity of the core was 0.707 while that of the base collection was 0.665. The higher diversity index in the core collection indicates that it maintains the initial variability and well represents the base collection. The core collection included one of determinate accession (IT 216155) and two of no branching type accessions (IT 103959 and IT 161024). The core collection could be used to guide more efficient management and utilization of the entire collection. This core collection should be revised periodically as additional accessions are collected and further characterization is conducted.
        209.
        2008.11 KCI 등재 서비스 종료(열람 제한)
        GIUH 유도식 대신 삼각형 가정의 간략식이 많은 연구에서 사용되고 있으나, 다양한 지형매개변수를 가진 유역에서 GIUH 간략식의 적용성에 대해서 알려진 바가 없다. 본 연구에서는 지도의 해상도를 변화시켜 방림, 상안미, 무성, 병천 등 4개 소유역을 각각 3차와 4차 하천유역으로 나타내고, GIUH 유도식과 간략식을 사용하여 각 유역의 순간단위도를 산정하였다. 각각의 순간단위도에 개의 호우사상을 적용하여 유출수문곡선을 계산하였으며, 이를 관측 유량과
        210.
        2008.03 KCI 등재 서비스 종료(열람 제한)
        프탈레이트는 화장품 원료로서 사용되지 않지만 네일락카, 헤어스프레이 제품류 등에는 혼입 또는 오염에 의해 제품 중에서 검출되어 시민단체 등에 의해 지속적인 안전성 문제가 제기되고 있기에 이들 제품에 대한 정확한 함량분석은 매우 중요하다. 그러나, 대부분의 프탈레이트 시험은 수질 또는 환경시료 등에서 다량의 유기용매로 추출/농축하여 가스크로마토그래피-질량분광분석기(GC-MS)를 사용하여 미량의 함량을 분석하는 방법으로 화장품 분석에 적용하기가 쉽지 않으며 화장품 분석에 적용되는 공인시험법도 아직까지 없는 실정이다. 또한 질량분석기의 가격, 시료전처리 및 기기유지관리에 소요되는 비용과 시간이 적지 않아 일반적인 품질관리에 적용하기엔 부담이 적지 않다. 특히 프탈레이트의 ppm 수준 이하 농도 분석시에는 기기 및 기구, 시약 등의 오염에 의해 분석결과 수치가 높게 나타나는 문제점으로 인해 정확한 분석기술과 분석경험이 매우 중요하다. 이에 본 연구에서는 네일락카와 헤어스프레이 제품 분석에 적합하며 품질보증(quality-assurance ; Q.A)을 위한 시험에도 유용하도록 저비용의 범용적인 기기를 사용하면서 ppm 농도의 프탈레이트를 빠른 시간에 분석할 수 있는 방법을 설계하였다. 이 방법은 유기용매 사용량을 최소화하여 친환경적이며, 시료전처리 시간과 단계를 줄여 오염의 가능성을 최소화하며 저비용의 가스크로마토그래피-불꽃이온화검출기(GC-FID)를 사용하여 제품 내 2 ∼ 50 g/g (ppm) 농도의 프탈레이트를 검출하는 분석법으로 관련업체에서 매우 유용하게 사용될 수 있을 것이다.
        211.
        2007.12 KCI 등재 서비스 종료(열람 제한)
        복부 단순방사선 촬영은 흉부촬영에 이어 가장 많이 검사가 이루어지고 있는 실정인 것이 임상현장 이므로 환자의 피폭선량에 대한 연구가 필수적으로 진행이 이루어 질 필요성이 대두가 된다. 그 결과는 다음과 같았다. 1. 관전압이 60-85kV 증가 시 표면선량은 증가하고, 촬영거리를 50-150cm로 20cm씩 증가함에 mAs도 증가시킨 결과 표면선량은 감소되었다. 2. 심부선량 백분율은 60-75kV에서는 4cm 깊이, 80-85kV에서는 6cm 깊이에서 50% 이하를 나타 내었으며, 60kV에서는 12cm 깊이, 65-85kV에서는 14cm 깊이에서 5% 이하를 나타났다. 3. 전방산란율은 60-85kV까지 관전압이 증가 시 10-11.78%까지 증가함을 나타내었다. 후방 산란 율은 관전압이 60-85kV 증가 시 25-37%로 증가하였다. 측방산란율은 음극 측에서는 관전압이 60-85kV 증가 시 1.63-2.95%로 완만하게 증가하나 양극측은 그 반대로 감소하는데 그 원인은 heel effect 현상 때문인가 사료된다. 후방산란율이 가장 크고, 그 다음이 전방산란율, 측방산란율 순으로 작아짐을 알 수 있다.
        212.
        2007.11 KCI 등재 서비스 종료(열람 제한)
        In Korea, chilli pepper (Capsicum annum L.) is a major vegetable crop. The pepper seed market is about $35 million and the whole sale market including processed products is equivalent to $2 billion, representing the second highest market value among crops, next to rice in Korea. Since the development of elite pepper variety is so competitive, vegetable seed companies usually run two important programs to keep the credibility of seed quality. One program is to deliver F1 hybrid seeds with a high purity test to farmers. The purity control of parents and F1 hybrid to avoid any contamination is conducted by DNA markers because pepper seeds are obtained using MS line. The other program is to identify the F1 variety from other varieties by analyzing the polymorphism so that the company and/or breeder protects the intellectual property from copying by others or from non-intentional contamination. We have developed about 900 EST-SSR sets from pepper and used to both programs. A total of 66 markers were selected to identify 32 F1 varieties and their own parents. Using these markers, the purity control of F1 hybrid rose up to the highest degree. We also found several SSR markers to distinguish F1 variety from other varieties and these markers could be useful to find the uniqueness of F1 cultivar.
        219.
        2007.05 KCI 등재 서비스 종료(열람 제한)
        A three-dimensional linear model and the Advanced Regional Prediction System (ARPS) were used to simulate parabola-shaped disturbances and clouds in the lee of a bell-shaped mountain. The ARPS model was compared in the x-y plane against the linear model's analytic solution. Under similar conditions with the linear theory, the ARPS produced well-developed parabola-shaped mountain disturbances and confirmed the features are accounted for in the linear regime. A parabola-shaped cloud in the lee of an isolated bell-shaped mountain was successfully simulated in the ARPS after 6 hours of integration time with the prescribed initial and boundary conditions, as well as a microphysical scheme.
        220.
        2007.03 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to assess genetic diversity among 16 genotypes of boxthorn (Lycium chinensis Mill.) using inter-simple sequence repeat (ISSR) markers. The 18 ISSR primers out of 100 primers showed the amplification of 101 reproducible fragments. A total of 56 DNA fragments were polymorphic with an average 3.1 polymorphic bands per primer. The polymorphic primers were divided into 16 anchored primers and 2 non-anchored primers. All of the anchored primers were di-nucleotide repeat motif, and polymorphism level was higher in the primers with poly GA and CT motif than CA and GT motif primers. Based on polymorphism, cluster analysis was conducted by the unweighted pair-group method with arithmetic average (UPGMA) methods. Sixteen boxthorn varieties and accessions were separated into 2 distinctive groups and genetic distance of cluster ranged from 0.82 to 0.97. Eighteen markers were able to distinguish every variety. Therefore, ISSR markers may be suitable for characterizing the large numbers of germplasms and fingerprinting of boxthorn varieties.
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