• Title/Summary/Keyword: Difference-in-Differences

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Differences in Vowel Duration Due to the Underlying Voicing of the Following Coda Stop in Russian and English: Native and Non-native Values

  • Oh, Eun-Jin
    • Speech Sciences
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    • v.13 no.3
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    • pp.19-33
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    • 2006
  • This study explores whether Russian, known to have a process of syllable-final devoicing, reveals differences in vowel duration as a function of the underlying voicing of the coda stop. This paper also examines whether non-native speakers of Russian and English learn typical L2 values in vowel duration. The results indicate that vowels in Russian have a slightly longer mean duration before a voiced stop than before a voiceless stop (a mean difference of 9.52 ms), but in most cases the differences did not exhibit statistical significance. In English the mean difference was 60.05 ms, and the differences were in most cases statistically significant. All native Russian speakers of English produced larger absolute differences in vowel duration for English than for Russian, and all native English speakers of Russian produced smaller absolute differences for Russian than for English. More experienced learners seemed to achieve more native-like values of vowel duration than less experienced learners did, suggesting that learning occurs gradually as the learners gain more experience with the L2.

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Research on the Causes of Sex Difference in Science Achievements by High School Students (고교생의 성별에 따른 과학과목의 성취도 차이의 원인에 대한 연구)

  • Lee, Moon-Won;Cho, Hee-Hyung
    • Journal of The Korean Association For Science Education
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    • v.5 no.1
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    • pp.35-47
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    • 1985
  • It is well known that high school girls' mean achievement levels in science tests are lower than high school boys' and that fewer women than men are employed as scientists and engineers pursue scientific careers. Many research attributed the sex difference in achievement level in science and the lack of women in science among others, to the experiential differences in scientific activities and the differences in attitudes toward science and scientists. Therefore, the study had its object to examine the sex difference by high school students in scientific experience and attitudes toward science and scientists. The differences in science experiences were identified at eight schools over rural and urban areas in Kangwon province. Science activities surveyed included use of experimental materials and instruments, observation of scientific phenomena, and extracurricular scientific activities. Attitude scale contained the nature of science, scientific research methods and philosophical views held by scientists. The study found sex differences in scientific experiences and attitudes. i. e.: fewer high school girls than boys had experience with scientific activities, especially with extracurricular activities; however, girls had more positive attitude toward science and more active desire to participate in science. Consequently, the study implies that, in order to narrow the gaps between achievement levels for boys and girls, science education should take consideration of the sex difference in experiences with and attitudes toward science.

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The evaluation of fabric on the Internet -The difference of cotton fabric texture perceived between on-line and off-line- (인터넷에서의 소재 평가에 대한 연구 -실물과 영상에서의 면직물 유사성 평가-)

  • 신혜원;이정순
    • Journal of the Korean Society of Clothing and Textiles
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    • v.28 no.3_4
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    • pp.396-402
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    • 2004
  • The purpose of this study was to investigate the difference of cotton fabric texture perceived between on-line(screening fabric) and off-line(real fabric), and to analyze fabric characteristics having an effect on the difference. The similarity of 55 various cotton fabrics perceived between on-line and on-line were measured showing simultaneously real fabrics and screening fabrics by 7-scale questionnaire. And the characteristics of cotton fabrics such as weave structure, thickness, weight, fabric density, stiffness, Hunter's L, a, b, and hue were measured. Cotton fabrics were classified into 3 groups by extent of similarity. There were no significant differences in weft density, stiffness, Hunter's L, a, b, and hue among 3 groups. But there were significant differences in weave structure, thickness, weight, warp density, and difference of warp & weft density. The fabrics having large similarity were thick and heavy, had small warp density and difference of warp & weft density, and distinct surface texture. The group having medium similarity included fabrics of medium thickness and weight, having weak surface texture, large warp density and difference of warp & weft density. The group having small similarity, which the differences between on-line and off-line were large, included thin and light fabrics having smooth surface and large warp density and difference of warp & weft density.

Generational Differences in the Perception of Korean Stops

  • Kang, Kyoung-Ho
    • Phonetics and Speech Sciences
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    • v.2 no.3
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    • pp.3-10
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    • 2010
  • The proposal that a sound change is occurring in Korean stops was evidenced in this study through identification experiments on Korean stops. Perceptual weight of acoustic correlates to Korean stop manner contrast [VOT (Voice Onset Time), H1-H2 (amplitude difference between the first and second harmonics), and F0 (Fundamental frequency)] was examined with re-synthesized /$t^ha$/, /ta/, and /$t^*a$/ syllables for younger and older Seoul speakers of Korean. For the identification of the aspirated and lenis stops, F0 cue weight relative to VOT was greater for the younger listeners than the older listeners. For H1-H2 cue weight, the two listener groups were more or less the same. These findings were parallel to the production differences found in the earlier work of the author. Combined with production differences, these perception differences between younger and older generations of Seoul speakers suggested that there are generational differences in the phonetic targets of Korean aspirated and lenis stops and such differences are realized in the perception of the stops.

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The Difference in School life Satisfaction by Middle School Soccer Club Participation (축구 학교스포츠클럽 참여가 중학교 남학생의 학교생활 만족도에 미치는 영향)

  • Park, Bong-Mo;Kim, Du-Gyu;Heo, Gyun
    • Journal of Fisheries and Marine Sciences Education
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    • v.27 no.2
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    • pp.345-352
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    • 2015
  • The purpose of this study was to identify the difference of school life satisfaction of middle school students according to soccer school sports club participation from a practical view. The results were follows; According to the results of analysis of the school life satisfaction between participating in soccer school sports club students and non participating student, significant differences(p<.001) were found in general school life, fellowship, teachers, learning, school rules and school events. As the results of analysis of the school life satisfaction according to the participating period, no significant differences were shown in general school life, fellowship, teachers, learning, school rules and school events. As the results of analysis of the school life satisfaction according to the participating motivation, no significant differences were found in general school life, fellowship, learning, school rules and school events, but significant difference(p<.05) was found in teachers. As the result of analysis of the school life satisfaction according to the engagement time, no significant differences were shown in general school life, teachers, learning, school rules and school events, but significant difference(p<.001) was found in fellowship.

Income Differences in Smoking Prevalences in 245 Districts of South Korea: Patterns by Area Deprivation and Urbanity, 2008-2014

  • Kim, Ikhan;Bahk, Jinwook;Yoon, Tae-Ho;Yun, Sung-Cheol;Khang, Young-Ho
    • Journal of Preventive Medicine and Public Health
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    • v.50 no.2
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    • pp.100-126
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    • 2017
  • Objectives: The aim of this study was to measure income differences in smoking prevalence at the district level and to investigate correlations among area deprivation, smoking prevalence, and income differences in smoking prevalence, stratified by urbanity. Methods: Data were pooled from the Community Health Survey data of South Korea between 2008 and 2014. The age-standardized prevalence of smoking and its interquintile income differences were calculated. We conducted correlation analyses to investigate the association of the deprivation index with smoking prevalence and interquintile differences in smoking prevalence. Results: Across 245 districts, the median prevalence of smoking in men was 45.9% (95% confidence interval [CI], 43.4 to 48.5%), with an interquartile range (IQR) of 4.6% points. In women, the median prevalence was 3.0% (95% CI, 2.4 to 3.6%) and IQR was 1.6% points. The median interquintile difference in smoking prevalence was 7.4% points (95% CI, 1.6 to 13.2% points) in men and 2.7% points (95% CI, 0.5 to 4.9% points) in women. The correlation coefficients for the association between the deprivation index and smoking prevalence was 0.58, 0.15, -0.22 in metropolitan, urban, and rural areas, respectively, among men, and 0.54, -0.33, -0.43 among women. No meaningful correlation was found between area deprivation and interquintile difference in smoking prevalence. The correlation between smoking prevalence and interquintile difference in smoking prevalence was more evident in women than in men. Conclusions: This study provides evidence of geographical variations in smoking prevalence and interquintile difference in smoking prevalence. Neither smoking prevalence nor the deprivation index was closely correlated with interquintile income difference in smoking prevalence. Measuring inequalities in smoking prevalence is crucial to developing policies aimed at reducing inequalities in smoking.

The Difference of Goods Attribute, Brand Awareness by Fashion Brand Type (패션브랜드 유형에 따른 상품속성, 브랜드 인지의 차이)

  • Yoo, Tai-Soon;Shin, Won-Hye
    • Fashion & Textile Research Journal
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    • v.8 no.6
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    • pp.647-654
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    • 2006
  • The purpose of this study is to identify the differences among goods attribute and brand awareness on fashion brand type. we were intended to suggest characteristics of each consumer group by identifying the differences of consumers' purchasing activities. 672 of consumers by brand who frequently purchase casual brand were chosen for the analysis according to common brand classification of national brand, private brand and no brand. For the purpose of data analysis, we performed factorial analysis of measuring tools and credibility test. Concerning the differences of goods attribute, brand awareness by brand type, MANOVA, ANOVA was employed, complimented with Sheffe-test as a post hoc test in case of occurrence of any differences by group. The findings from the analysis are described in the following. Regarding goods attribute by fashion brand type, there existed a significant difference between brand types in all the sub factors of goods attribute such as product attribute, shop attribute, and price attribute. Especially, the difference of product attribute is much more significant in the areas of material suitableness, product assortment, aesthetic expression, size & quality, clothing maintenance, and clothing comfortableness. In case of shop attribute, there was a significant difference between groups in all the factors such as shop environment, convenience of shopping, sales promotion, service quality of sales clerk, location, and shop reputation. Concerning price attribute, we found a significant difference between groups in the factors of price value, price reasonableness, price information, and economical efficiency of price. As for the difference of brand awareness by brand type, among other factors, brand value had a difference between groups; that is, private brand was found to obtain the highest brand value awareness.

The Effects of Hot and Cold Therapy on Vital Sign and Blood Components (${\cdot}$ 냉 적용이 Vital sign 및 혈액 성분에 미치는 영향)

  • Park, Kyu-Hyun;Jun, Kyong-Hee;Park, Rae-Joon
    • The Journal of Korean Physical Therapy
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    • v.13 no.2
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    • pp.313-324
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    • 2001
  • The 15 male students of T-college which is located in Taegu, who don't have any cardiovascular diseases and skin diseases and agreed to the experiment for finding out the effects of hot and cold therapy. They were divided 5 experimental groups, that is hot therapy in blood Pressures, hot therapy group showed significantly difference of systolic blood Pressure. And the hot therapy group and hot and cold therapy showed the distinctive differences in Scheffes' s analysis after the fact. 3. There was no significant difference in pulsation between before and after experiment and there were no differences in each group. 4. The hot therapy group showed significant difference in WBC and didn't show any difference in RBC(p<.05). 5. Timing does not effect to each group in the changes of HGB and HCT. 6. In the comparison between before and after the experiments in the changes of MCV, cold therapy group showed significant measurement. And in the comparison between before and after one hour the experiment in the changes of MCV, cold therapy group showed significant measurement. The experimental group 1 and 3 showed the distinctive differences in Scheffe' s analysis after the fact(p<.05). 7. In the comparison between before and after one hour experiments in MCV changes, the cold therapy group had significant differences(p<.05). 8. There were no significant differences between before and after the experiments in MCHC changes. 9. In the comparison between before and after one hour experiments in PLT changes, cold therapy group had significant changes(p<.05) and there were no differences among three group.

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Sex Differences in Cancer: Epidemiology, Genetics and Therapy

  • Kim, Hae-In;Lim, Hyesol;Moon, Aree
    • Biomolecules & Therapeutics
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    • v.26 no.4
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    • pp.335-342
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    • 2018
  • The incidence and mortality of various cancers are associated with sex-specific disparities. Sex differences in cancer epidemiology are one of the most significant findings. Men are more prone to die from cancer, particularly hematological malignancies. Sex difference in cancer incidence is attributed to regulation at the genetic/molecular level and sex hormones such as estrogen. At the genetic/molecular level, gene polymorphism and altered enzymes involving drug metabolism generate differences in cancer incidence between men and women. Sex hormones modulate gene expression in various cancers. Genetic or hormonal differences between men and women determine the effect of chemotherapy. Until today, animal studies and clinical trials investigating chemotherapy showed sex imbalance. Chemotherapy has been used without consideration of sex differences, resulting in disparity of efficacy and toxicity between sexes. Based on accumulating evidence supporting sex differences in chemotherapy, all clinical trials in cancer must incorporate sex differences for a better understanding of biological differences between men and women. In the present review, we summarized the sex differences in (1) incidence and mortality of cancer, (2) genetic and molecular basis of cancer, (3) sex hormones in cancer incidence, and (4) efficacy and toxicity of chemotherapy. This review provides useful information for sex-based chemotherapy and development of personalized therapeutic strategies against cancer.

Effects of Partial Cervus elaphus Linne' Extract on Antitumoral Immune Response in Melanoma-induced Mice (부위별(部位別) 녹용(鹿茸)이 흑색종(黑色腫) 유발(誘發) 생쥐의 종양억제(腫瘍抑制)와 면역기능(免疫機能)에 미치는 영향(影響))

  • Oh Ha-Souk;Kim Jang-Hyun
    • The Journal of Pediatrics of Korean Medicine
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    • v.14 no.1
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    • pp.39-78
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    • 2000
  • Introduction: In order to investigate the effects of partial Cervus elaphus Linne' extract on antitumoral immunological, a group of mice are melanoma-induced and observed reponses in terms of the number of lymphocyte, CD4+ count, CD8+ count, CD4+/CD8+ ratio in blood and spleen, change in body weight, melanoma weight, spleen index, NK cell activity and productivity of IL-2 in each mouse Methodology: Male C57BL/6 mice were chosen as an experimental object and were divided into 5 groups randomly selection. The normal group did not receive any induction. The control group was treated with normal saline in melanoma-induced' mice. Sample I group induced the upper part of Cervus elaphus Linne' extract in melanoma-induced mice. Sample II group was induced the middle part of Cervus elaphus Linne' extract in melanoma-induced mice. Sample III group was induced the lower part of Cervus elaphus Linne' extract in melanoma-induced mice. The dosage of medication was 0.2cc daily for 14days. Results: 1. There was a significant difference in the number of lymphocyte in spleen in the sample I (upper part of Cervus elaphus Linne' extract induced) and the sample II (middle part of Cervus elaphus Linne' extract induced) compared to the control group and the sample III (lower part of Cervus elaphus Linne' extract induced). On the other hand, no significant difference was observed in the number of lymphocyte in blood in the control group and all sample groups. 2. In the CD4+ T cell ratio in blood, all three sample groups showed differences compared to the control group, though there was no significant difference between sample groups. In the CD4+ T cell ratio in spleen, there was a difference between the sample I and the control group, while the sample II and the sample III had significant difference to the control group. And also, it has been observed there were differences between the sample I and the other samples. 3. In the CD8+ T cell ratio in spleen, all three sample groups showed significant differences compared to the control group, while there was no difference between groups in the ratio in blood. 4. In the CD4+/CD8+ T cell ratio in blood, the sample I showed a significant difference compared to the control group, while the sample 1I and sample III showed differences compared to the control group. In the CD4+/CD8+ T cell ratio in spleen, all three samples showed a significant difference compared to the control group, when the sample I had a difference to the other sample groups. 5. The spleen index of the sample I and the sample II showed a significant difference compared to the sample III and the control group. In comparison between the sample groups, the sample I and the sample II showed a significant difference to the sample III. 6. In terms of the change in body weight and melanoma weight, all three sample groups showed a significant difference compared to the control group, while the comparison between the sample groups showed the sample and the sample II had a significant difference to the sample Ⅲ. 7. In comparison of NK cell activity, the sample I had a difference compared to the other groups when the effector to target cell ratio was 2.5:1. With the ratio of 5:1, the sample I and sample II showed significant differences compared to the control group, while the sample Ⅲ showed a difference. When the effector to target cell ratio was 10:1, there was no difference between groups. 8. In the productivity of IL-2, all three sample groups showed significant differences compared to the control group. In comparison between sample groups, there were significant differences between each sample groups in order of the sample I , the sample II and the sample Ⅲ. Conclusion: As one can witness from the above results, administration of partial Cervus elaphus Linne extract played important role in antitumoral immune response in melanoma-induced mice, and it could be suggested that sample I and sample II groups have prominent antitumoral immune effect.

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