• Title/Summary/Keyword: random variation

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Response Variability of Laminated Composite Plates with Random Elastic Modulus (탄성계수의 불확실성에 의한 복합적층판 구조의 응답변화도)

  • Noh, Hyuk-Chun
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.21 no.4
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    • pp.335-345
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    • 2008
  • In this study, we suggest a stochastic finite element scheme for the probabilistic analysis of the composite laminated plates, which have been applied to variety of mechanical structures due to their high strength to weight ratios. The applied concept in the formulation is the weighted integral method, which has been shown to give the most accurate results among others. We take into account the elastic modulus and in-plane shear modulus as random. For individual random parameters, independent stochastic field functions are assumed, and the effect of these random parameters on the response are estimated based on the exponentially varying auto- and cross-correlation functions. Based on example analyses, we suggest that composite plates show a less coefficient of variation than plates of isotropic and orthotropic materials. For the validation of the proposed scheme, Monte Carlo analysis is also performed, and the results are compared with each other.

RAPD Polymorphism of Xanthoceras sorbifolium Bunge from Three Plantations of China (중국 3곳 문관나무 재배집단의 RAPD 다형성)

  • An, Chanhoon;Lee, Hyunseok;Yin, Zhiyang;Yi, Jae-Seon
    • Journal of Forest and Environmental Science
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    • v.28 no.4
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    • pp.242-246
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    • 2012
  • The variation in random amplified polymorphic DNA (RAPD) markers were examined for Xanthoceras sorbifolium Bunge seeds from three plantations (Inner Mongolia [IM], Liaoning [LN], and Shandong [SD] province) in China. Mean genetic variation was measured by polymorphism percentage (42.10%) and expected heterozygosity (He=1.27). Among three populations, Shandong showed the highest values both in polymorphism percentage and heterozygosity (p=57.89; Ho=1.58; and He=1.37). Total genetic diversity value, based on the total loci, was estimated as total genetic diversity of the species (Ht)=0.27 and mean within-population genetic diversity (Hs)=0.16. UPGMA cluster analysis showed the genetic closeness between Inner Mongolia and Liaoning population, but that Shandong seems to be the separate population.

Morphological and genetic variability among Ecklonia cava (Laminariales, Phaeophyceae) populations in Korea

  • Choi, Dong Mun;Ko, Young Wook;Kang, Rae-Seon;Kim, Jeong Ha
    • ALGAE
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    • v.30 no.2
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    • pp.89-101
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    • 2015
  • Ecklonia cava Kjellman is a common kelp found in shallow subtidal in warm-temperate waters in the northwest Pacific Ocean. This species has shown substantial morphological variation along with subsistence in different locations and local environments. We quantified the magnitude of morphological variation of E. cava from six populations along ~700 km of coastline from Jeju Island to Dokdo in Korea. In addition, we examined genetic distance among the populations using random amplified polymorphic DNA (RAPD) analysis. Most morphological characteristics investigated were significantly different among locations. Multivariate analyses indicated two phenetically distinct groups (nearshore, sheltered vs. offshore, exposed), indicating wave exposure with turbidity are presumably major factors for the separation. With RAPD data, results of Nei's diversity (H) and AMOVA showed considerable variations in within- and between-populations. Pairwise ${\Phi}_{ST}$ and $N_m$ values indicated moderate gene flow between the six locations. Results of Nei's analysis revealed three genetically distinct groups, not consistent with the morphological groupings, indicating that a time gap may exist between morphological and genetic variations. This study also suggests dispersal distance of this kelp may be longer than what is commonly thought and genetic similarity in the populations was largely reflected by the direction of ocean current rather than just geographical distance.

Analysis of Genetic Polymorphism Among Six Korean Wild Artemisia spp. by Using RAPD Method (RAPD 방법을 이용한 한국 야생쑥 6종간의 유전적 유연관계 분석)

  • Pyo, Hyun Jin;Choi, Kwan Sam
    • Korean Journal of Agricultural Science
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    • v.23 no.1
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    • pp.99-107
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    • 1996
  • Eighteen nuclear probes were used to examine RFLP(restriction fragment length polymorphism) between six species of Artemisia spp. of Korea. Total DNA from six different species of Artemisia was separately cut with three restrict enzymes. The PstI enzyme was showed to reduce the variation of polymorphisms than the other two enzymes(EcoRl and BamHI). The genetic variation of polymorphism was similar between the Dhewegiki-ssug and Cham-ssug. RAPD analysis was applied to the same six species of Artemisia spp. in order to assess the degree of DNA polymorphism within the Artemisia genus. Six species of Artemisia were evaluated for variation using a set of 11 random 10-mer primers. Nine out of the eleven primers revealed scorable polymorphisms between six species of Artemisia spp. Genetic distances between each of the species were calculated and cluster analysis was used to generate a dendrogram showing phylogenetic relationships between them This result indicates that molecular markers will be more usable in intraspecific study of Artemisia spp. than isoenzyme markers.

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The Empirical Study of Variation of KOSPI Index & Macro Economic Variation (거시경제 변수 변화와 KOSPI 지수 변동의 연관성 분석)

  • An, Chang-Ho;Choi, Chang-Yeoul
    • International Commerce and Information Review
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    • v.12 no.4
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    • pp.171-192
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    • 2010
  • In general, a stock index and its individual stocks are assumed to follow a random walk. A stock index is an important source of information and one that is seen by people everyday, regardless of their investment intentions. This paper examines the correlation between the KOSPI-the index that best reflects the Korean stock market and the macro - economic variables that have been found to influence the index by previous studies. The sample period considers the years after 2000 when the Korean stock market matured as restrictions on foreign investors were removed. For this purpose, a Vector Error Correction Model (VECM) and KOSPI equation with a general pacific approach were used. This paper aims at verifying the factors that determined the KOSPI after 2000 and at examining whether there was structural change in the investment environment. It also investigates changes in the factors determining the KOSPI's performance as a result of structural changes in the investment environment. The V AR (Vector Autoregressive) model including the nine variables was selected as a baseline model whose stability was tested using the unit root test. The results from the VECM and the structural changes in the investment environment can be summarized by the following Inner story points.

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Application of UPOV Data for the Analysis of Genetic Variation in Rose Cultivars

  • Kim, Gi-Jun;Song, Young-Ha;Gi, Gwang-Yeon;Kim, Seong-Tae;Lee, Ja-Hyun;Han, Tae-Ho
    • Horticultural Science & Technology
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    • v.29 no.3
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    • pp.240-246
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    • 2011
  • The principal objective of this study was to estimate the availability of morphological data on the basis of the guidelines of the International Union for the Protection of New Varieties of Plants (UPOV) with regard to the identification of the rose germplasm. The correlation of morphological traits and random amplified polymorphic DNA (RAPD) marker data among 44 rose cultivars was assessed via a mantel test. Thirty eight phenotypes were employed for morphological analysis. Sixteen primers were utilized for RAPD analysis, and these generated 225 polymorphic bands. The dendrogram based on the RAPD markersgrouped 44 rose cultivars according to their horticultural types. No significant correlation was observed between the morphological and RAPD marker data. We concluded that current UPOV traits could not be applied to study genetic variation. Further studies on morphological traits are required for the analysis of genetic variation among cultivars.

Comparison of Genetic Diversity and Population Structure of Kalopanax pictus (Araliaceae) and its Thornless Variant Using RAPD

  • Huh, Man-Kyu;Jung, Sang-Duk;Moon, Heung-Kyu;Kim, Sea-Hyun;Sung, Jung-Sook
    • Korean Journal of Medicinal Crop Science
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    • v.13 no.2
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    • pp.69-74
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    • 2005
  • Kalopanax pictus is a long-lived woody species mostly distributed in East Asia. K. pictus has been regarded as medically and ecologically important species in Korea. Thornless castor aralia variant, local name 'Cheongsong' is an endemic to Cheongsong province in Korea. Random amplified polymorphic DNA (RAPD) was used to investigate the genetic variation and structure of Korean populations of two species. A high level of genetic variation was found in six K. pictus populations. Twelve primers revealed 49 loci, of which 29 were polymorphic (59.2%). Nei's gene diversity for K.pictus and K. pictus variant were 0.119 and 0.098, respectively. Mean of genetic diversity in K. pictus was higher than average values for species with similar life history traits. The asexual and sexual reproduction, perennial habitat, and longevity are proposed as possible factors contributing to high genetic diversity. An indirect estimate of the number of migrants per generation (Nm=0.857) indicated that gene flow was not extensive among Korean populations of K.pictus. It is suggested that the isolation of geographical distance and reproductive isolation between K.pictus and K.pictus variant populations may have played roles in shaping the population structure of this species.

Gage R&R Study on Abdominal Sonography for Measuring Distance from Sangwan (CV13) to Pancreas - A Pilot Study - (복부초음파를 이용한 상완혈(上脘穴)-췌장 수직거리 측정시스템의 재현성 반복성 평가실험-A Pilot Study-)

  • Nam, Dong-Hyun
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.14 no.2
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    • pp.75-84
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    • 2010
  • Objectives: The objective of the current study is to determine whether an ultrasound device system is adequate for measuring distance from Sangwan (CV13) to pancreas. Methods: We recruited 3 healthy young male subjects and 2 sonographers. The each sonographer measured vertical shortest distance from CV13 to pancreas with a ultrasound device three times in random order. Because the total variation could be divided into repeatability, reproducibility and subject-to-subject variation in Gage R&R method, we compared the sources of variation associated with the measurement system with an analysis of variance model. Results & Conclusions: Number of distinct categories is calculated on the basis of standard deviation of subject-to-subject divided by standard deviation of total Gage R&R. If the number of categories is five or more, the measurement system may be acceptable for the analysis of the process. The number of distinct categories of the ultrasound device system for measuring distance from CV13 to pancreas was 6.29. So we concluded that repeatability and reproducibility of the ultrasound device system for measuring distance from CV13 to pancreas was acceptable.

Determination of Representative Shear Wave Velocity Profile for Rockfill Zone of CFRD Considering Uncertainty Caused by Spatial Variation of Material Property (국내 콘크리트 표면차수벽형 석괴댐(CFRD) 사력존의 전단파 속도 분포 결정(II): 물성치의 공간 변동성에 의한 불확실성이 고려된 CFRD 사력존의 1차원 전단파 속도 주상도의 결정)

  • Hwang, Hea-Jin;Park, Hyung-Choon
    • Journal of the Korean Geotechnical Society
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    • v.30 no.5
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    • pp.17-24
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    • 2014
  • This paper determines 1D shear wave velocity (Vs) distribution of rockfill zone of CFRD using Vs profile determined by the surface wave test. There exists uncertainty in the field test result because of a spatial variation of material property. The harmonic wavelet transform is used to evaluate the uncertainty of test result and generate random 1D Vs distributions which may exist in the rock fill zone. Through the statistical analysis of generated random Vs distributions, the representative 1D Vs distribution considering the uncertainty of test results is proposed for the rockfill zone of CFRD in Korea.

Random Distribution based Decision Model of Design Factor having Time Variable in Building Energy Conservation Design (시간변수를 가진 건물에너지 절약 설계요소의 디자인 결정을 위한 확률분포 결정모델)

  • Woo, Se-Jin
    • The Journal of the Korea Contents Association
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    • v.10 no.3
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    • pp.21-31
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    • 2010
  • In the architectural design technologies being changed recently, there is the study to develop the way that will enable the designers to get access logically to the processes of deciding the values of design factors which depend on the experience of the designers. This study, which is one part of those studies, has been carried out to develop the model that can decide the values logically for the design factors having the character that the design values are changed by the time variation out of design factors involved in the building energy saving design. As a result, the structure of the decision model which can decide the design values logically from the computer simulation that solve the problem by interpreting the real world as the probability distribution, has been established through this study. For the application and verification of these decision model, the case study has been carried out for the outdoor climate factors that stand for the design factors having the time variation.