• 한국소음진동공학회논문집
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• 제13권5호
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• pp.384-392
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• 2003

The fuel rods in the Pressurized water reactor are continuously supported by a spring system called a spacer grid which is one of the main structural components for the fuel rod cluster(fuel assembly). The fuel rods vibrate within the reactor due to coolant flow. Since the vibration, which is called flow-induced vibration(FIV) can wear away the surface of the fuel rod, it is important to understand it's vibration characteristics. In this paper, the vibration analyses and the tests for the dummy rods supported by New Doublet(ND) spacer grids are described. A new FE model which reflects the contact area between the rod and ND spacer grid spring is developed to replace the previous one by which a good agreement could not be obtained with the vibration test. The natural frequency and mode shape calculated by both the Previous FE model and the new one are compared with those of experiment for a single-spanned rod supported by two ND spacer grids. The results of the new model showed good agreement with the experiment compared with those of previous model. In addition. the new FE model is applied to the vibration analysis for the dummy rod of 2.189 mm tall continuously supported by five ND spacer grids. It is also obtained that the analysis results of the new FE model well agreed to experiment ones as the single-spanned rod.

• 한국의류산업학회지
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• 제6권1호
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• pp.93-101
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• 2004

The purpose of this study is to examine consumers' risk perception in internet clothing shopping and its relation with technology readiness and the frequency of purchase. Thereafter, this study examines how consumers' risk perception affect service quality and satisfaction at the apparel shopping sites. An on-line survey was made to collect data, and the replies from 785 people, who had an experience of apparel shopping on line, were used in data analysis. From factor analyses, risk perception comprised 3 factors of product related risk, delivery related risk, and security related risk, and technology readiness comprised 4 factors of optimism, innovativeness, discomfort, and insecurity. Based on cluster analysis, consumers were classified into 3 types in terms of the internet risk perception: low risk group, medium risk group, and high risk group. From path analysis, risk perception was decreased with high frequency of purchase and low discomfort and insecurity of technology readiness, and risk perception and service quality had an influence on consumers' satisfaction with the shopping sites.

• Bulletin of the Korean Chemical Society
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• 제33권10호
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• pp.3338-3342
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• 2012

Covalent functionalization of a $B_{12}N_{12}$ nano-cage with $CO_2$ molecule has been investigated using density functional theory in terms of energetic, geometric, and electronic property analyses. Results show that besides two physisorption configurations, $CO_2$ preferably tends to perform [2+2] addition on B-N bonds of the cluster which are shared between six-membered and four-membered rings, releasing energy of 14.99 kcal/mol for adsorption of the first $CO_2$ and of 15.45 kcal/mol for the second one (per each molecule). On the basis of calculated density of states, we have found that the electronic properties of the physisorbed $B_{12}N_{12}$ by $CO_2$ have not changed, while slight changes have been predicted in the functionalized cases. Present results might be helpful to provide an effective way to modify the $B_{12}N_{12}$ properties for further purifications and applications.

• 한국의상디자인학회지
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• 제12권2호
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• pp.91-105
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• 2010

The purposes of this study were to segment consumers by life style groups and to investigate the differences among the segmented groups in regard to Korean image preferences in casual wear. The subjects of the study were 653 women consumers who lived in Seoul. Data were collected from July to September, 2007. Statistical analyses used in the study were factor analysis, cluster analysis, ANOVA, and Scheffe test. The results showed that there were seven factors of life style: fashion and appearance interest, pride in Korea, sociability, interest in foreign culture, family centered, sports/culture, and interest in Korean food. Based on the seven factors, the consumers were segmented into three groups. They were fashion/diverse culture interest group, family/recreation oriented group, and sociability/family oriented group. The results showed that there were significant differences among the lifestyle segmented groups in regard to Korean image preferences for color, fabric, pattern, and categories of casual wear, and the intention to purchase the casual wear. For example, fashion/diverse culture interest group preferred diverse Korean prints, red, orange, blue and white colors, natural fabrics, and various types of casual wear. Also, the group has the highest interest and intention in wearing Korean image casual wear.

• The Plant Pathology Journal
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• 제33권1호
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• pp.34-42
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• 2017

Grapevine rupestris stem pitting-associated virus (GRSPaV) is a worldwide-distributed pathogen in grapevines with a high genetic variability. Our study revealed differences in the complexity of GRSPaV population in a single host. A single-variant GRSPaV infection was detected from the SK30 grapevine plant. On the contrary, SK704 grapevine was infected by three different GRSPaV variants. Variant-specific RT-PCR detection protocols have been developed in this work to study distribution of the three different variants in the same plant during the season. This study showed their randomized distribution in the infected SK704 grapevine plant. Comparative analysis of full-length genome sequences of four Slovak GRSPaV isolates determined in this work and 14 database sequences showed that population of the virus cluster into four major phylogenetic lineages. Moreover, our analyses suggest that genetic recombination along with point mutations could play a significant role in shaping evolutionary history of GRSPaV and contributed to its extant genetic diversification.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.66.1-66
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• 2003

The aim of this study was to characterize the interactions of rice and Burkholderia glumae, a causal agent of bacterial grain rot of rice, at molecular levels using whole genomic sequences and to identify genes important for pathogenicity and symptom development. To do these, we sequenced whole genome of the bacterium and constructed cosmid clone profiles. We generated pools of mutants using various transposons and determined mutation sites by sequencing rescued plasmids. We focused on studying toxoflavin biosynthetic genes, quorum sensing regulation, and Hrp type III protein secretion systems. We found that two possible operons consisting of five genes are involved in toxoflavin biosynthesis and their expression is regulated by quorum sensing and LysR-type regulator, ToxR. We have isolated the nn PAI of B. glumae and characterized by mutational analyses. The hrp cluster resembled most the putative Type III secretion systems of B. pseudomallei, which is the causative agent of melioidosis, a serious disease of man and animals. The Hrp PAI core region showed high similarity to that of Ralstonia solanacearum and Xanthomonas campestris, however some aspects were dissimilar.

• 한국환경보건학회지
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• 제38권5호
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• pp.369-379
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• 2012

Objectives: Spatial analysis is useful for understanding complicated causal relationships. This paper focuses trends and appling methods for spatial analysis associated with environmental asbestos exposure. Methods: Literature review and reflection of experience of authors were conducted to know academic background of spatial analysis, appling methods on epidemiology and asbestos exposure. Results: Spatial analysis based on spatial autocorrelation provides a variety of methods through which to conduct mapping, cluster analysis, diffusion, interpolation, and identification. Cause of disease occurrence can be investigated through spatial analysis. Appropriate methods can be applied according to contagiousness and continuity. Spatial analysis for asbestos exposure source is needed to study asbestos related diseases. Although a great amount of research has used spatial analysis to study exposure assessment and distribution of disease occurrence, these studies tend to focus on the construction of a thematic map without different forms of analysis. Recently, spatial analysis has been advanced by merging with web tools, mobile computing, statistical packages, social network analysis, and big data. Conclusions: Because the trend in spatial analysis has evolved from simple marking into a variety of forms of analyses, environmental researchers including asbestos exposure study are required to be aware of recent trends.

• 한국의류학회지
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• 제34권10호
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• pp.1647-1657
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• 2010

This study examines underwear purchase behaviors and the attitude of male consumers based on the degree of interest in appearance. Data research was conducted on 296 males in their 20s and 30s located in Seoul & Gyeonggi province. The SPSS 17.0 software program was used to conduct data analyses such as descriptive statistics, frequency analysis, factor analysis, cluster analysis, t-test, and $\chi^2$-test. The results of this study are as follows: The degree of interest in appearance was identified with four factors; outfit management, confidence of figure, interest in clothing, weight control, and disinterest in appearance. Customers were segmented into two subdivisions: high and low interest in appearance. The factors derived from the factor analysis of underwear purchase motive included aesthetic, impulsiveness, and practicality. The purchase behavior of the group with high interest in appearance was highly motivated by aesthetics and impulsiveness. The factors derived from the factor analysis of underwear attitude included fashionability, comfortableness, and quality. Customers were segmented into the following three subdivisions: pursuit of comfortableness, pursuit of diversity, and normal. The type of high interest in appearance regarded fashionability and quality highly. Finally, the degree of interest in appearance showed significant relevance in purchase motive and underwear attitude for underwear.

• 한국생활과학회지
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• 제10권1호
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• pp.73-82
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• 2001

The aim of this study is to provide the basic data for clothing construction of pre-school children by the result of the analyses and classifications of children's upper body somatotypes. The objects of this study are the bodies of 220 male pre-school children from 3 to 6 years old. The method of anthropometric measurement is the direct and photographic measurement. After analysing the measurements, 7 factors were extracted and the factors were applied to the cluster analysis. As the results, the 4 types were classified. Type 1 was characterized by the shortest and normal body one among these four types. This type showed the forward-curved back, the projected abdomen, and the fallen shoulders. Type 2 was characterized by the normal height and the fattest body type. Type 3 was characterized by the slimmest body and the shorter height type. Type 4 was characterized by the tallest and normal body with the rising shoulders.

• 한국물환경학회지
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• 제32권3호
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• pp.281-290
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• 2016

In the northernmost basin of the Bukhan River, pollution sources can have a concentrated distribution. In these basins, small streams show low flow with various and rapid water quality change in low pollutants load. Therefore, a water quality improvement plan of small streams and main stem will be necessary to establish the characteristics of small streams. This study selected a representative Hwacheon-gun in the northernmost basin of the Bukhan River. Hydro analysis was performed with GIS tools using DEM. A total of 152 small streams were listed. A total of 51 survey locations were selected after applying the selection criteria. Flow rate and water qualities were investigated. Pollution sources and pollutants loads were calculated for each basin. Pollution grade and typological classification were performed by cluster analysis using standardized environmental condition factors. As a result, G04, G01, H01 locations were found to have the worst pollution grades whereas J01, P01, and P02 had less pollution. Typological analyses were able to classify six types for the surveyed small streams. An effective water quality improvement plan was obtained based on the results of pollution grade and typological analysis using environmental condition factors of this study.