• Korean Journal of Materials Research
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• v.12 no.9
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• pp.750-760
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• 2002

In this study, three solders, Sn-37Pb, Sn-3.5Ag, and Sn-3.8Ag-0.7Cu were screen printed on both electroless Ni/Au and OSP metal finished micro-via PCBs (Printed Circuit Boards). The interfacial reaction between PCB metal pad finish materials and solder materials, and its effects on the solder bump joint mechanical reliability were investigated. The lead free solders formed a large amount of intermetallic compounds (IMC) than Sn-37Pb on both electroless Ni/Au and OSP (Organic Solderabilty Preservatives) finished PCBs during solder reflows because of the higher Sn content and higher reflow temperature. For OSP finish, scallop-like $Cu_{6}$ /$Sn_{5}$ and planar $Cu_3$Sn intermetallic compounds (IMC) were formed, and fracture occurred 100% within the solder regardless of reflow numbers and solder materials. Bump shear strength of lead free solders showed higher value than that of Sn-37Pb solder, because lead free solders are usually harder than eutectic Sn-37Pb solder. For Ni/Au finish, polygonal shaped $Ni_3$$Sn_4$ IMC and P-rich Ni layer were formed, and a brittle fracture at the Ni-Sn IMC layer or the interface between Ni-Sn intermetallic and P-rich Ni layer was observed after several reflows. Therefore, bump shear strength values of the Ni/Au finish are relatively lower than those of OSP finish. Especially, spalled IMCs at Sn-3.5Ag interface was observed after several reflow times. And, for the Sn-3.8Ag-0.7Cu solder case, the ternary Sn-Ni-Cu IMCs were observed. As a result, it was found that OSP finished PCB was a better choice for solders on PCB in terms of flip chip mechanical reliability.

• Journal of Korean society of Dental Hygiene
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• v.15 no.2
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• pp.271-278
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• 2015

Objectives: The aim of this study was to investigate the effect of water fluoridation program(WFP) on dental caries prevention in Ulsan, Korea. Methods: The data of control group were extracted from 2012 Korean National Oral Health Survey(KNOHS). Since 1998, WFP was implemented in Ulsan. The subjects were 670 subjects including 10 to 12-years old children in 2009. The control subjects were 4,871 people in non-fluoridated metropolitan cities comparable to Ulsan. The control subjects were selected from 2012 KNOHS. A self-reported questionnaire was completed by the variables including oral health behaviors on daily frequency of toothbrushing, eating snacks and beverages. Oral health examination was carried out by two dentists who received a training in KNOHS with an inter-examiner-agreement. Caries preventive fraction was calculated by the difference of DMFT and DMFS index. The preventive effects of the WFP program were focused on gender, number of fissure sealed teeth, daily frequency of toothbrushing, eating snacks and beverages. Data were analyzed using SPSS $19.0^{(R)}$(SPSS Inc., Chicago, IL, USA) statistical package. Results: DMFT indices of 12-year-old subjects(n=670) in WFP and control population(n=4,871) were 2.11 and 1.23, respectively with an estimated prevention effect of 41.7%. Conclusions: WFP in Ulsan reduced the prevalence of dental caries. WFP should be recommended for the public oral health program in other metropolitan cities.

• Journal of the Korean Society of School Health
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• v.9 no.1
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• pp.99-108
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• 1996

The purpose of the survey was to identify the degree and the relationship of sexual knowledge, sexual attitude and need of sex education. This information will provide useful data for a more systematic. desirable, and practical sex education. The data was collected from 300 first grade schoolchildren (150 boys and 150 girls) of two Junior high school in K city. The data was gathered by questionnaire from Nov.21 to 28, 1995. The questionnaire was modified by authors using the questionnaire developed by Lief & Reed. Data was analyzed by using the statistical computer package, SAS to manipulate the data along with percentages, means, standard deviation, t-test, $X^2$-test, GLM, and Pearson correlation coeffiency. The results in this study were summarized as follows: 1. Sexual knowledge. - The mean score of sexual knowledges showed no significant differences between boys and girls(p<0.6180), but in the areas of biological differences(boys; $11.57{\pm}2.43$, girls; $10.93{\pm}2.41$, p<0.0242), and pregnancy physiology(boys; $9.28{\pm}1.87$, girls; $10.04{\pm}2.42$, p<0.0026) showed significant difference between boys and girls. 2. Sexual attitudes. - The mean score of sexual attitudes showed no significant difference between boys and girls (p<0.8286), but in the areas of masturbation (boys : $6.69{\pm}2.22$, girls : $5.65{\pm}1.88$, p<0.0001), and premarital intercourse (boys : $5,42{\pm}1.35$, girls : $6.00{\pm}1.33$, p<0.0002) showed significant difference between boys and girls 3. Need of sex education. - The majority of the subjects wanted to learn about sexual delinquency and it's prevention(57.7%), form a friendship with the other sex(56.3%), physical differences of the other sex(52.0%), psychological differences and the charateriatics of the other sex (50.3%) and meaning of love(50.3%). 4. The relationships between sexual knowledges and sexual attitudes. - Those who had higher sexual knowledges showed more positive attitudes towards sex, and showed statistical significance(r=0.2074, p<0.0003). 5. The relationships between general charateristics and sexual knowledge. - Better students(by self-perception of school performance) had higher knowledge scores about sex. 6. The relationships between general charateristics and sexual attitudes. - Those who wanted to learn more about sex, and better students had higher attitude scores about sex. - Those who were in high standard of living had higher attitude scores about sex as well. Suggestions based on above study are as follows' 1. The planned sex education showed be performed to the schoolchildren establish responsible attitudes about sex. 2. Systematic sex education through formal school education according to age is recommended. 3. Further studies should be done to measure the effect of sex education based on the needs of the schoolchildren.

• Animal Bioscience
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• v.34 no.11
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• pp.1739-1748
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• 2021

Objective: In recent years, long noncoding RNAs (lncRNAs) have been identified in many species, and some of them have been shown to play important roles in muscle development and myogenesis. However, the differences in lncRNAs between Kazakh cattle and Xinjiang brown cattle remain undefined; therefore, we aimed to confirm whether lncRNAs are differentially expressed in the longissimus dorsi between these two types of cattle and whether differentially expressed lncRNAs regulate muscle differentiation. Methods: We used RNA-seq technology to identify lncRNAs in longissimus muscles from these cattle. The expression of lncRNAs were analyzed using StringTie (1.3.1) in terms of the fragments per kilobase of transcript per million mapped reads values of the encoding genes. The differential expression of the transcripts in the two samples were analyzed using the DESeq R software package. The resulting false discovery rate was controlled by the Benjamini and Hochberg's approach. KOBAS software was utilized to measure the expression of different genes in Kyoto encyclopedia of genes and genomes pathways. We randomly selected eight lncRNA genes and validated them by quantitative reverse transcription polymerase chain reaction (RT-qPCR). Results: We found that 182 lncRNA transcripts, including 102 upregulated and 80 downregulated transcripts, were differentially expressed between Kazakh cattle and Xinjiang brown cattle. The results of RT-qPCR were consistent with the sequencing results. Enrichment analysis and functional annotation of the target genes revealed that the differentially expressed lncRNAs were associated with the mitogen-activated protein kinase, Ras, and phosphatidylinositol 3-kinase (PI3k)/Akt signaling pathways. We also constructed a lncRNA/mRNA coexpression network for the PI3k/Akt signaling pathway. Conclusion: Our study provides insights into cattle muscle-associated lncRNAs and will contribute to a more thorough understanding of the molecular mechanism underlying muscle growth and development in cattle.

• Journal of Animal Science and Technology
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• v.49 no.5
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• pp.559-568
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• 2007

Recently, copy number variations (CNV) of genes or genomic segments have been intensively studied and various analysis methods have been developed. In this study, quantitative oligonucleotide ligation assay (qOLA) was applied to investigate CNV of KIT gene in the Landrace breed. A combined assay using qOLA and pyrosequencing, 6 genotype classes, I1/I1 or I3/i (IBe), I1/I2 or I3/IP, I1/I3, I1/IP or I2/i (IBe), I2/I2and I2/IP, were identified from 44 Landrace pigs. Genotype assignment using grouping features of measurements on a scatter plot showed 100% agreement with those using a statistical assignment by PROC FASTCLUS procedure implemented in the SAS package. Two versions (3100 and 3130) of ABI sequencers gave the same genotyping results, indicating there was no influence on qOLA by different versions of instrument, however, the means of standard deviation and coefficient of variation from the qOLA on a ABI 3130 (2.33 and 4.10) was lower than those from the qOLA on a ABI 3100 (2.67 and 4.81). Effect of proteinase K treatment on the PCR product followed by qOLA was very clear because noise peaks were disappeared and the observed ration fit better to the reference ratio corresponding to each genotype.

• Journal of Food Hygiene and Safety
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• v.28 no.1
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• pp.7-12
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• 2013

This study presents the influence on growth properties determined using a novel predictive growth model of wild-type Salmonella spp. KSC 101 by variations in the temperature and time during cut packaging in cold, uncooked pork meat. The experiment performed for model development included an arrangement of different temperatures ($0^{\circ}C$, $5^{\circ}C$, $10^{\circ}C$, $15^{\circ}C$, and $20^{\circ}C$) and time durations (0, 1, 2, and 3 hours) that reflect actual pork-cut and packaging processes. No growth was observed at $0^{\circ}C$ and $5^{\circ}C$, whereas some growth was observed at $10^{\circ}C$, $15^{\circ}C$, and $20^{\circ}C$, with a mean increase of only 0.34 log CFU/g. The growth observed at $20^{\circ}C$ was more robust than that observed at $15^{\circ}C$, but the difference was not statistically significant (p > 0.05). However, compared with PMP (Pathogen Modeling Program), the wild-type Salmonella spp. KSC 101 showed a more rapid growth. We used the Gompertz 4 parameter equation as the primary model, and the exponential decay formula as the secondary model. The estimated $R^2$ values were 0.99 or higher. The developed model was evaluated by comparison of the experimental and predictive values, and the values were in agreement with the ${\pm}0.5$ log CFU/g, although the RMSE (Root mean square error) value was 0.103, which indicates a slight overestimation. Therefore, we suggest that the developed predictive growth model would be useful as a tool for evaluating sanitation criteria in pork cut-packaging processes.

• Journal of Global Scholars of Marketing Science
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• v.19 no.2
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• pp.53-67
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• 2009

For the last decades, service quality has been studied as one of the most important tools for a service company to compete with the other companies. Based on these past researches, it has been agreed that the service quality is a basic and powerful tool to create the competitive advantage. Due to similar reason, many service marketing practitioners have been also focused on the service quality to retain the existing consumers and collect the new consumers. However, service quality is subjectively perceived by individual consumers. Consumer evaluation of service quality can be different from each other. Especially consumers with one life-style may evaluate the service quality differently from the consumers with the other life-styles. Therefore we need to know whether there are differences in service quality perception on the categories of life-style. Life-style refers to a distinctive mode of living in its aggregate and broadest sense. It embodies the patterns that were developed and emerged from the dynamics of living in a society. Since the concept of life-style and its relationship to marketing was introduced in 1963 by William Lazer, methods of measuring the life-style and their application have been developed. Life-style has been usually used to segment the marketplace because it offers marketers a unique and important view of the market. When Life-style is combined with clustering methods, life-style segmentation can generate identifiable whole persons rather than isolated fragment. Life-style segmentation begins with people instead of products and classifies them into different life-style types, each characterized by a unique style of living based on a wide range of activities, interests, and opinions(Plummer, 1974). In this study we applies the life-style segmentation based on the AIO(Activities, Interests, and Opinions) to the consumers of the large discount stores. In Korea, the large discount store market has entered into maturity stage so that the market differentiation strategy is becoming a more critical issue to the marketing practitioners. One of the most important tools to differentiate from the competitors in large discount store market is continuously to provide service of better quality than competitors. This study tries to find answers about the following questions: 1) How can we categorize the consumer life-styles in the large discount store? 2) What are the characteristics of the categorized groups? 3) Are there any differences in service quality perception among the consumers with different life-styles 4) Are there any differences in consumer behavior among them in the large discount store? For the purpose, we collected survey data from consumers and analyzed the data with the SPSS package where we had $X^2$-test, factor analysis, ANOVA, MANOVA, and cluster analysis. The survey was made during one month in the April of 2008. Among the collected 306 copies of questionnaires, 281 copies were chosen as the effective samples for empirical analysis except 25 copies with wrong responses. To identify the life-style patterns, we used the measures employed by Kim and Kwon(1999), where 44 items on a seven-point scale were used to measure factors of the life-style patterns. The Principal Component Method was used for factor extraction, and the VARIMAX orthogonal factor rotation was employed. The 7 items showing low factor loading were eliminated. The results of the factor analysis suggested that nine factors of the life-style patterns were identified as follows: 1) the equality-of-sexes and pursuit-of-independence tendency 2) self-management tendency 3) sociable tendency 4) self-display tendency 5) degree of a dilettante life 6) pursuit-of-information tendency 7) bargain hunter tendency 8) TV preference tendency 9) pursuit-of-leisure tendency. Next, after the K-means cluster analysis was performed with nine factors of the life-style patterns, the life-styles of the respondents were classified into four groups which are named as the 'progressive practicality-oriented group', 'positive success-oriented group', 'sociable ostentation-oriented group', 'stable conservation-oriented group'. The analysis results for usage behavior between the market segments showed statistically significant differences in the frequency of usage, duration time in the store, consumer satisfaction, and loyalty. Also, we tried to investigate whether the large discount store consumers differently perceive the quality of service based upon the types of life-style. To measure the service quality of large discount store, we adapted several measurement models measuring the service quality such as SERVPERF, BCP, R-SERVPERF, R-BCP. MANOVA and One-Way ANOVA were performed to confirm the difference in service quality perception based on the market segments. The results have also shown significant differences between life-style types in service quality perception. These findings show that the large discount store marketers should consider consumer life-style as one of the most important market segments for marketing and understand the difference in service quality perception between life-style types. Our findings give important implications to marketers of large discount stores as well as life-style researchers. First, this study showed there were significant differences in consumer's service quality perception and usage behavior between the types of life-style. It provides evidence that the life-style approach can be a important basis in segmenting the large discount store market and will make consumers perceive the service quality high. Second, most previous researches on service quality have been in aggregate level. However, our results imply that the future research on service quality have to focus on segment level.

• Journal of Environmental Impact Assessment
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• v.27 no.6
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• pp.685-694
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• 2018

We measured ecological niche space (ENS) using carbon and nitrogen stable isotope ratios of benthic macroinvertebrates to estimate its applicability for large river assessment. In particular, we compared ENSs of selected macroinvertebrates between upper and lower area of Seungchon Weir in Yeongsan River to estimate the impact of weir on biological community. We also measured basic water quality and community indices including benthic macroinvertebrates index (BMI) to estimate their correlations with calculated ENS. ENS was calculated using the Bayesian Stable Isotope in R statistics (package "SIBER"). The results showed that seasonal variations in water quality and community indices were found, but there was no apparent tendency between upper and lower area of the Seungchon Weir in June (before rainy season) and August (after rainy season). However, ENS of benthic macroinvertebrates markedly decreased across the weir in both June and August regardless of changes in water quality. This means the physical change of the stream due to the weir cause decrease of ecological isotopic niche space of benthic macroinvertebrates regardless of water quality, suggesting physical modification by the weir can affect the interaction between habitat condition and macroinvertebrates. Therefore, the ecological isotopic niche space can be a useful supplementary indicator for the river ecosystem assessment.

• Horticultural Science & Technology
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• v.19 no.4
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• pp.521-525
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• 2001

This study investigated the effects of conventional predrying and modified atmosphere (MA) on the head quality and storability of Chinese cabbage 'Norang' cultivar. Immediately after harvest, heads were predried for 2 days and MA stored in $50{\mu}m$ PE film packages at $4^{\circ}C$. MA packaging restrained Hunter L and b values of Chinese cabbage more effectively than non-packaging during storage at $4^{\circ}C$. But there was little change between the two treatments. Fresh weight decreased less in heads treated with predrying and MA than non-treatment during storage. Predried Chinese cabbage heads kept a high level of soluble solids in 4 weeks of storage, while non-packaging maintained high contents of soluble solids for 6 weeks of storage period. Chinese cabbage heads contained 7.0 mg/gFW glucose, 6.3 mg/gFW fructose, and 0.6 mg/gFW sucrose as major soluble sugars at harvest. The content of sugars decreased immediately after predrying and increased steadily after 2 weeks storage. It was found inappropriate to assess head quality of Chinese cabbage by investigating was investigated by Hunter a, firmness, dry matters content, pH, and soluble sugars after predrying and MA package. Marketability of Chinese cabbage was lost when heads were stored at room temperature in 2 weeks. It showed poor appearance of heads stored at $4^{\circ}C$ in 7 weeks. Decay occurred in Chinese cabbage stored in MA under excessive relative humidity. Predried head showed good appearance during storage at $4^{\circ}C$ for 7 weeks. As a result, Chinese cabbage heads can be successfully stored for at least 7 weeks with predrying and MA storage.

• Research in Community and Public Health Nursing
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• v.9 no.2
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• pp.467-481
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• 1998

The purpose of this survey, in which 2754 students from 35 middle schools from Taegu city participated, was to identify the degree and the relationship of sexual knowledge, sexual attitude and need for sex education. This information will provide useful data, and promote a more systematic, desirable and practical sex education. The data was collected from September 1 to November 8, 1997. Data was analyzed using the statistical computer package, SPSS to manipulate the data along with percentage, mean, $X^2$-test. t-test, F-test and Pearson correlation coefficient. The results from this study were summarized as follows: 1. The mean score of sex related knowledge showed significant differences between boys and girls in general knowledge(boys: 10.85 girls: 11.71, p=0.000), in the area of physical development(boys : 5.29 girls: 5.72, p=0.000), pregnancy & physiology (boys: 3.23 girls: 3.57, p=0.000) and venereal disease (boys: 2.33 girls: 2.42, p=0.000). 2. The mean score of sex related attitudes showed a significant differences between boys and girls on the whole(boys : 57.68 girls: 58.92, p=0.000), in the area of psychological differences of the other sex (boy: 26.13, girls: 28.08, p=0.000), and sexual delinquency and its prevention(boy: 14.28, girls: 13.68, p=0.000). However, in the area of other sex friendships (boy: 17.28, girls: 17.16, p=0.274). There were no significant differences between boys and girls. 3. Those who had a higher sex related knowledge score showed more positive attitudes towards sex, but was of no statistical significance(r= 0.312, p=0.000). 4. The majority of subjects wanted to learn about friendship with the other sex(40.1%), about physical and psychological differences in adolescence(24.0%), about prevention of sexual violence(15.0%), about pregnancy and delivery (7.5%), about venereal disease and medical cures(7.3%), about contraception methods (4.3%), as well as other aspects of sexual knowledge (1.8%), 5. The mean score of sex related knowledge generally was higher when one paid a lot of attention to health (F= 3. 148, p=0.014), when one's father was alive(t=3.930, p=0.000), and when one's mother was alive(t=2.807, p=0.005), Hobby activities also showed a significant difference(F=9.092, p=0.000). The mean score of sex related knowledge generally according higher when one had sex education(F=9.470, p=0.000), when one obtained sexual knowledges from a teacher (F = 5. 742, p=0.000), and when one had middle grade problems with sex(F=13.58 4, p=0.000). 6. The mean score of sex related attitudes generally showed significant differences when re ligion(F=2.691, p=0.03), hobbies (F= 3.499, p= 0.002) were considered. Those who had a father also had higher scores(t=2.538, p= 0.011). The mean score of sex related attitudes generally with respect to a subject's sex was higher when one had sex education(t=5.338, p= 0.000), when one had high grade problems with sex(F=6.023, p=0.002), and when one had the experience of friendship with the other sex(t= 8.106, p=0.000), The following suggestions are based on the above results, 1. Systematic sex education must be performed in middle schools in order to establish responsible attitudes toward sex, 2. Sexual knowledge, attitude, and general sex education classes must be performed seperately for early, middle, and late adolescents, In other words sex education programs are needed for each adolescent development stage.