• Corrosion Science and Technology
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• v.23 no.1
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• pp.1-10
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• 2024

Oil well casing leak is caused by contact of casing outer surface with formation electrolyte. It is usually associated with an aquifer with a high salt content or absence of a cement ring behind the casing. The only way to reduce external casing corrosion is through cathodic protection. Through cathodic polarization of casing structure, electron content in crystal lattice and electron density will increase, leading to a potential shift towards the cathodic region. At Tatneft enterprises, cathodic protection is carried out according to cluster and individual schemes. The main criterion for cathodic protection is the size of protective current. For a casing, the protective current is considered sufficient if measurements with a two-contact probe show that the electric current directed to the casing has eliminated all anode sites. To determine the value of required protective current, all methods are considered in this work. In addition, an analysis of all methods used to determine the minimum protective current of the casing is provided. Results show that the method of measuring potential drop along casing is one of the most reliable methods for determining the value of protective current.

• Korean Journal of Ichthyology
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• v.17 no.3
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• pp.173-186
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• 2005

Genomic DNA was isolated from two geographic populations of largehead hairtail (Trichiurus lepturus) in Korea and the Atlantic Ocean. The eight arbitrarily selected primers were found to generate common, polymorphic, and specific fragments. The complexity of the banding patterns varied dramatically between primers from the two locations. The size of the DNA fragments also varied widely, from 150 bp (base pairs) to 3,000 bp. Here, 947 fragments were identified in the largehead hairtail population from Korea, and 642 in the largehead hairtail population from the Atlantic Ocean: 148 specific fragments (15.6%) in the Korean population, and 61 (9.5%) in the Atlantic population. In the Korean population, 638 common fragments with an average of 79.8 per primer were observed.; 429 common fragments, with an average of 53.6 per primer, were identified in the Atlantic population. The number of polymorphic fragments in the largehead hairtail population from Korea and the Atlantic Ocean was 76 and 27, respectively. Based on the average bandsharing values of all samples, the similarity matrix ranged from 0.784 to 0.922 in the Korean population, and from 0.833 to 0.990 in the Atlantic population. The bandsharing value of individuals within the Atlantic population was much higher than in the Korean population. The dendrogram obtained by the eight primers indicated two genetic clusters: cluster 1 (KOREAN 01~KOREAN 11), and cluster 2 (ATLANTIC 12~ATLANTIC 22). Individual KOREAN no. 10 from Korea was genetically most closely related to KOREAN no. 11 in the Korean population (genetic distance = 0.038). Ultimately, individual KOREAN no. 01 of the Korean population was most distantly related to ATLANTIC no. 16 of the Atlantic population (genetic distance = 0.708).

• The Journal of the Korea Contents Association
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• v.18 no.4
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• pp.369-379
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• 2018

The purpose of this study is to examine the impact of social enterprise's shared value creation on corporate performance and to develop policy measures to enhance competitiveness of social enterprises. The main results and implications are as follows. First, according to the general characteristics of social enterprises, the difference between shared value creation and organizational performance was not statistically significant. In other words, although the social enterprise has various organizational characteristics, it does not differ from the shared value creation or the organizational performance that it creates. The rapid increase of social enterprises led to a rapid increase in various types of social enterprises, but there is no difference between shared value creation and organizational performance. Second, the results of analyzing the impact of shared value creation on the organizational performance of social enterprises revealed that social performance was statistically significant influenced by re-recognition of product market and regional cluster among sub-factors of shared value creation. Among the sub-factors of social enterprise's economic performance, the re-recognition of the product market had a statistically significant effect on the overall organizational performance of social enterprises. Among the sub-factors of shared value creation. In the future, it will be necessary to make effort to improve corporate performance by introducing the concept of shared value creation for social enterprise and making policy efforts to activate it.

• Journal of Gifted/Talented Education
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• v.24 no.4
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• pp.509-541
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• 2014

There was a great need to consider a core competency-based approach as a new direction of the science education for gifted students according to the value and vision of the 21st century knowledge-based societies. Therefore we developed a core competency model of scientist and examined its validity as a prerequisite for a core competency-based education of science gifted students. In order to this, the survey was conducted after developing questionnaire through the theoretical review of the various resources such as paper, book, and newspaper articles and the qualitative analysis of the behavioral event interview, and then an exploratory factor analysis was performed to validate the factor structure based on the results of the survey. The results revealed that the core competency model with the 5 cluster units of competency and the 15 core competencies was potentially constituted. And the reliability, convergent validity, and discriminant validity of the core competency model were verified through the confirmatory factor analysis. The cognitive cluster consisted of 5 competencies and they were as follows: creative, comprehensive, exploratory, analytical, and conceptual thinking competency. The achievement-orientation cluster consisted of 3 competencies and they were as follows: initiative, preparation & problem solving, and strategic influence competency. The scientific attitude cluster consisted of 3 competencies and they were as follows: flexible thinking & attitude, passion for research, and views about science competency. The personal effectiveness cluster consisted of 2 competencies and they were as follows: diverse experiences and global attitude competency. Finally, the networking cluster consisted of 2 competencies and they were as follows: personal understanding and communication competency. Findings were expected to provide the basic data for developing programs and establishing strategies based on the core competency as well as introducing the core competency model of scientist to science education for gifted students effectively.

• Journal of Distribution Science
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• v.14 no.8
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• pp.129-138
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• 2016

Purpose - The present study theoretically reviews the use of power norm according to the cultural orientation of consumers to categorize the shopping value that corresponds to the use of the power norm when consumers use local food stores. Research Design, Data, and Methodology - Based on the data collected from the survey to 130 undergraduates, salaried men and people at large, the group with cultural value orientation was divided further into the group of horizontal individualism and that of vertical collectivism by using cluster analysis of SPSS 18.0 program. And regression analysis of SPSS 18.0 was employed to verify the hypotheses. Results - The following conclusions were shown in the empirical study. First, in the group of vertical collectivism, contribution to regional profits and competitiveness, economic value and service superiority can positively affect the attitude to the local food stores while the social responsibility activity in the community can't. In the group of horizontal individualism, however, contribution to regional profits and competitiveness, social responsibility activity, economic value and service superiority were all found to positively affect the attitude to the stores. Second, the distinctive shopping value of the stores such as escapism, entertainment value and prestige does not affect the attitude to the stores. Third, the positive effects that the stores' level of responsibility for the outgroup community can exercise on the attitude to the stores turned out to be bigger in the group of horizontal individualism than in the group of vertical collectivism. Fourth, the impact that the degree of the stores' contribution to regional profits and competitiveness has on the attitude to the stores was found to be positive in both groups. However, no difference existed in the degree of positive effects between them. Conclusions - Marketing managers of local food stores should pay more attention to managing their contribution to practical shopping value and to interests as well as competitiveness of regional society, and to persuading consumers of the horizontal individualistic group by performing responsible activities for the outgroup of local society regardless of the types of consumers' cultural orientation.

• Child Health Nursing Research
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• v.7 no.4
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• pp.494-510
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• 2001

As a family respond to any stressful situation as a whole system, cancer diagnosis of a child, as a serious life event, could be emotional shock to destroy homeostasis of the family system. A family has a resilient capacity to adjust and adapt to stressful events. Previous studies have been focused on family stress and adaptation, but little attention has been given to family value as one of resilient factors. The data for model testing were collected from July 18, 2000 to August 30, 2000 and the analysis included 309 parents of children who are diagnosed as cancer, 18 or less years of age, and treated either hospitalized or at the outpatient clinics. The data analysis utilized SAS 6.12 and LISREL 8 for descriptive statistics, correlation, cluster analysis, factor analysis, and LISREL. The study findings are as follows. 1) Monthly income (γ=-0.28, t=-5.81) was the most important factor to explain family strain along with family support (γ=-0.11, t=-2.43), severity of children's illness (γ=0.26, t=5.22), and family stressor (γ=0.22, t=4.62). All of these factors together explained 40％ of variance in family strain. 2) Among general family value, the relationship with the parents (γ=0.28, t=4.89) and relationship with the children (γ=0.20, t=3.60) showed positive effects to family value for cancer children, while relationship with the spouse (γ=-0.19, t=-3.22) and the age of the cancer children (γ=-0.11, t=-2.21) showed negative effects. These predictors together explained 22％ of variance in family value for cancer children. 3) Family hardiness was explained mostly by family strain (γ=-0.53, t=-8.65) along with direct negative effects of family persistency and indirect negative effects of severity of children's illness, family stressor, relationship with the spouse, and the children's age. Family value for cancer children was the most important predictor with positive effect (γ=0.44, t=6.76) along with indirect effects of monthly income, relationship with the parents, relationship with the children, support from family and significant others, and confidence with the health professionals. 51％ of variance in family hardiness was explained by all of these predictors. 4) The most important predictor for family adaptation was family stressor (γ=-0.50, t=-6.85) with direct and indirect negative effects along with the severity of children's illness (γ=-0.27, t=-5.21). However, family value for cancer children showed compromised total effect (γ=-0.13, t=-1.99) with negative direct effects (γ=-0.28, t=-3.43) and positive indirect effects (γ=0.14, t=3.01). Similarly, confidence with the health professionals also showed compromised total effect (γ=0.09, t=1.99) with positive direct effects and negative indirect effects. Family hardiness showed the biggest positive direct effects while other factors such as monthly income, family stressor, family persistence, support of family and significant others, relationship with the parents, relationship with the children, and relationship with the spouse, and children's age showed indirect effects only. 39％ of variance in family adaptation was explained by all of these predictors.

• Journal of Digital Contents Society
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• v.9 no.1
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• pp.33-39
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• 2008

Mobile Ad Hoc Network is easy to be attacked because nodes are distributed not network based infrastructure. Intrusion detection system perceives the trust values of neighboring nodes and receives inspection on local security of nodes and observation ability. This study applied clustering mechanism to reduce overhead in intrusion detection. And, in order to measure the trust values, it associates the trust information cluster head received from member nodes with its own value and evaluates the trust of neighboring nodes. Secure data transmission is received by proposed concept because the trust of nodes on network is achieved accurately.

• Journal of The Korean Association For Science Education
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• v.15 no.2
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• pp.194-200
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• 1995

The purpose of this study is to investigate the attitudes related to the science of elementary and middle school students. The instrument used for measuring attitudes was developed by Korea National University of Education. 1488 students were sampled by stratified cluster sampling method. The major findings of this study are as follows. 1.Elementary school students have significantly higher attitude scores than middle school students. 2.The value of Pearson's correlation coefficient among the sub-categories of science attitudes was 0.3773 - 0.6336, which was significant at the 0.001 level. 3.There was no statistically significant difference between grade and sex in middle school students. 4.There was statistically significant difference between grade and sex in elementary school students.

• Journal of the Korea Safety Management & Science
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• v.6 no.2
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• pp.187-197
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• 2004

The recycling cell formation problem means that disposal products are classified into recycling product families using group technology in their end-of-life phase. Disposal products have the uncertainties of product condition usage influences. Recycling cells are formed considering design, process and usage attributes. In this paper, a new approach for the design of cellular recycling system is proposed, which deals with the recycling cell formation and assignment of identical products concurrently. Fuzzy ART neural networks are applied to describe the condition of disposal product with the membership functions and to make recycling cell formation. The approach leads to cluster materials, components, and subassemblies for reuse or recycling and can evaluate the value at each cell of disposal products. Disposal refrigerators are shown as an example.

• Journal of the Korean Society of Clothing and Textiles
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• v.19 no.5
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• pp.811-825
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• 1995

The purposes of the study were 1) to segment the female apparel market based on clothing benefits sought by female adualt consumer in Cheju, and 2) to develop a profile of each segment concerning lifestyle, use of information sources, perceived store attributes, store preference and demographics. The data(n=228) were collected via a questionnire from adult females of ages over 20's. Using cluster analysis on benefits sought factors, four groups were identified and labeled as 1) Economic-value oriented users of clothing(24%) : 2) Brand oriented users of clothing(14%); 3) Aesthetics/fashion oriented users of clothing(26%); 4) Easy care oriented users of clothing(36%). ANOVA and Chi-square statistics revealed significant differences among the four groups according to clothing benefits sought factors, lifestyle factors, use of information sources, store attributes perceived on store types, store-type choices, new store-type preferences and demographic variables. A profile of these groups was developed.