• Title/Summary/Keyword: cross over effect

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A Study on the Relationship between Game Addiction and Social Stigma of the Youth outside school (학교 밖 청소년의 게임중독과 사회적 낙인감에 관한 상호관계 연구)

  • Moon, Jin-Young;Park, Ju-Won;Lee, Chang-Moon
    • Journal of Digital Convergence
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    • v.18 no.1
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    • pp.343-355
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    • 2020
  • The purpose of this study was to analyze the relationship between game addiction and social stigma of adolescents outside school. After examining the previous research focusing on the Public stigma & Self-stigma theory, We intended to examine how game addiction and social stigma affect each other over time, and the time causal relationship between the both. Using youth outside school panel 3rd, 4th, 5th data, This study analyzed the relationship between game addiction and social stigma of adolescents with school interruption longitudinally. The research method was analyzed by autoregressive cross-lagged model using two variables such as game addiction and social stigma using Amos25 program. The results showed that game addiction did not significantly affect social stigma at the next time, but social stigma had a significant effect on game addiction at the next time. Game addiction and social stigma have a strong auto-regressive effect, and the degree remains constant over time. Accordingly, this study suggested social co-prosperity, support from the local community, multidisciplinary viewpoints and cooperation between the public and private sectors.

Effect of Subacute Ruminal Acidosis on Plasma Concentrations of Lipopolysaccharide in Dairy Cattle (젖소에 있어 아급성제1위과산증(SARA)의 강도가 혈장 Lipopolysaccharide (LPS)의 농도에 미치는 효과)

  • Son, Hey In;Baek, Seong Gwang;Moon, Ju Yeon;Ahn, Eui-Young;Lee, Hyun-Jun;Son, Yong Suk
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.33 no.4
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    • pp.313-318
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    • 2013
  • A study was conducted to determine if subacute ruminal acidosis (SARA) induced by feeding high level of non-structural carbohydrates results in increases in lipopolysaccharides (LPS) of peripheral blood in dairy cattle. In this experiment four Holstein steers, two of which having ruminal canulae with indwelling probes placed for measuring long term pH changes, were alloted into two dietary treatments in a cross-over design, where an acidogenic diet (AD) was formulated by including high amount of non-structural carbohydrates (NSC) based on corn silage and corn flake as TMR ingredients. Data for ruminal pH change and plasma LPS concentration were compared against normal diet (ND) which contained grass hay as forage and low NSC ingredients. Feeding AD for more than 14 days to animals brought about a pH change as low as less than 5.8 for more than 4 hours, which made good contrast to ND fed animals. Decreased ruminal pH also had an effect on LPS concentrations which showed significantly higher level for AD compared with ND. Therefore, plasma LPS concentration may be used as an effective indicator to verify acidosis whether it is acute or chronic. Na-bentonite and Propylene glycol, which are frequently included in dairy TMR as additives, helped decrease ruminal pH by buffering and then ultimately alleviates SARA. Therefore, it could also be helpful to lower the occurrence of laminitis which is often caused by increased blood endotoxin (LPS) concentration.

Effect of Plant Populations on the Number and Weight of Ear and Gross Income in Sweet Corn (재식밀도가 단옥수수의 이삭수, 이삭무게 및 조수입에 미치는 영향)

  • 이석순;백준호
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.35 no.2
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    • pp.117-121
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    • 1990
  • A sweet corn hybrid, Golden Cross Bantam 70, was grown at 5 plant populations (5,000, 6,000, 7,000, 8,000, and 9,000 plants/10a) under the transparent P .E. film mulch to find the best yield evaluation method. Plant population did not affect early plant growth, culm length, ear height, and silking date. However, number of tillers at harvest decreased but leaf area index increased with increased plant population. Marketable ears were divided into two classes; the first grade of which husked ear weight over l50g (unhusked ear weight 230g) and the second grade of which husked ear weight between 100 and 150g (unhusked ear weight between 180 and 230g) according to the whole sale market price. Average length, thickness, and weight of marketable ears over 100g of husked ears decreased with increased plant population. The proportion of ears over 150g decreased with increased plant population. However, total number and weight of marketable ears and gross income per 10a calculated considering weight and number of ears increased with plant population. There were highly positive correlations between gross income and ear number or ear weight per unit area. At high plant populations the number of marketable ears was overestimated but ear weight underestimated compared with gross income. Dry matter yield of stover increased with increased plant population and ranged 755-944kg/10a with 20.7-24.5% dry matter content. Rice black-streaked dwarf virus infection rate was 10.6-14.9%, but it was not related to plant population.

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Effects of Flux Activator on Wettability and Slump of Sn-Ag-Cu Solder Paste (플럭스 활성제 종류에 따른 Sn-Ag-Cu 솔더 페이스트의 젖음성 및 슬럼프 특성 평가)

  • Kwon, Soonyong;Seo, Wonil;Ko, Yong-Ho;Lee, Hoo-Jeong;Yoo, Sehoon
    • Journal of the Microelectronics and Packaging Society
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    • v.25 no.4
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    • pp.123-128
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    • 2018
  • Effect of activators in flux on the printability and wettability of a solder paste was evaluated in this study. The activators in this study were dicarboxylic acids, which were oxalic acid (n = 0), malonic acid (n = 1), succinic acid (n = 2), glutaric acid (n = 3), adipic acid (n = 4), and pimelic acid (n = 5). When the solder pastes were observed with a SMT scope, solder with glutaric acid showed clean and shiny surface when it was melted. Slump ratio of the solder pastes was low when the carbon numbers of the dicarboxylic acid were 1-3. Spreadability was high when the carbon number was over 2. Zero cross time of wetting balance test was under 1 sec when the carbon number was over 3. When activator was oxalic acid or malonic acid, zero cross time was over 1 sec and maximum wetting force was low. Fluxes with the oxalic acid and malonic acid showed decomposition at the temperature close to melting point. Among the dicarboxylic acids, glutaric acid provided excellent slump, spreadability, and wettability.

Factors Affecting Dementia Prevalence in People Aged 60 or Over: A Community based Cross-sectional Study (60세 이상 성인의 치매 관련 영향요인: 지역사회 기반 단면연구)

  • Kim, Seong Min;Seo, Hyun-Ju;Sung, Mi Ra
    • Journal of Korean Academy of Nursing
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    • v.44 no.4
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    • pp.391-397
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    • 2014
  • Purpose: This study was done to examine the association between body mass index (BMI) and any type of clinical dementia. Methods: Participants were 60,321 people over 60 years of age enrolled in the Seoul Dementia Management Project in 2011. K-MMSE was used to classify participants as having a cognitive impairment and the Clinical Dementia Rating or DSM-IV by psychiatrists or neurologists to determine whether participants were in the dementia group or the non-dementia group. Descriptive statistics, chi-square test, and binary logistic regression analysis were performed. Results: In the univariate analysis, age, education level, living with spouse, BMI, alcohol consumption, and exercise were significantly associated with dementia. In multivariable analysis, increasing age was positively associated with dementia, and educational level was negatively associated with dementia. The exercise group had a lower prevalence of dementia than the non-exercise group. The odds ratio of dementia in the over-weight and obese groups compared to the normal group was 0.85 (95% CI 0.60, 0.98) and 0.64 (95%CI 0.46, 0.75), respectively. Conclusion: Results indicate that dementia is negatively associated with increasing BMI in people aged 60 years or older, but a prospective cohort study is needed to elucidate the causal effect relationship between BMI and dementia.

Prevalence and Associated Factors of Osteoporosis among Postmenopausal Women in Chuncheon : Hallym Aging Study(HAS) (춘천지역 폐경 후 여성의 골다공증 유병률과 관련 요인: 한림노년연구)

  • Jang, Soong-Nang;Choi, Young-Ho;Choi, Moon-Gi;Kang, Sung-Hyun;Jeong, Jin-Young;Choi, Yong-Jun;Kim, Dong-Hyun
    • Journal of Preventive Medicine and Public Health
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    • v.39 no.5
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    • pp.389-396
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    • 2006
  • Objectives: A community-based, cross-sectional survey was conducted to determine theprevalence of osteoporosis and to evaluate the effects of body composition, health behaviors and reproductive history on bone density in postmenopausal women. Methods: The study subjects were 362 postmenopausal women, aged 45 years old or over, who were invited to the hospital. Information on their socio-demographic characteristics and the potential risk factors such as their past medical history, smoking, alcohol intake, exercise, diet and menstrual/reproductive histories were collected by trained interviewers. Weight, height, the body mass index ($kg/m^{2}$), and body composition variables were measured. Bone mineral density of the lumbar spine was measured by dual energy X-ray absorptiometry (DXA). Results: The prevalence of osteoporosis was 30.6% in the $45{\sim}64$ years old women, 52.5% in the elderly women aged $65{\sim}74$, and 68.7% in the women aged 75 years or over. After adjustment for the effect of potential covariates, those women in the highest 25% (4th quartile) of the lean body mass are less likely to have osteoporosis (aOR=0.31, 95% CI=0.12-0.76), compared with the lowest quartile group. More parity also had significantly detrimental effects on osteoporosis. Conclusions: These findings suggest that the prevalence of osteoporosis in postmenopausal women increased with age from 46.3% of those aged 45-64 to 68.7% for those aged 75 and over. Lean body mass and parity appeared significant contributor to bone mineral density in postmenopausal women in this population.

Effect of Dietary, Biochemical and Other Factors on Bone Mineral Density Change for 2 Years in Korean College Women (한국 여대생의 2년간의 골밀도 변화와 이에 영향을 미치는 요인 분석)

  • 송윤주;백희영
    • Journal of Nutrition and Health
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    • v.36 no.2
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    • pp.175-182
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    • 2003
  • This study was conducted to examine whether bone mineral density changes in 55 young Korean college women aged 19 to 26 years over 2 years and nutritional and biochemical factors are related. Bone mineral density (BMD) was measured in the spine (LS), femoral neck (FN), ward's triangle (WT), and femoral trochanter (FT) by dual energy X-ray absorptiometry three times at one-year intervals. Serum osteocalcin (OC), parathyroid hormone (PTH), and urinary cross-linked N-teleopeptides of type collagen (NTx) were measured. Dietary intake was assessed 8 times with 24-hour recall method. Physical activity (PA) was obtained by questionnaire and body fat content was measured by bioelectrical impedance analysis at baseline and after 2 years. Analyses were performed on 34 subjects with all three BMD measurements. The BMDs at the lumbar spine gradually increased over 2 years, while the BMDs of three sites at the femur were sustained or increased. The mean OC, PTH had a similar pattern with the change of BMD at the femur. The mean NTx decreased over 2 years but was still higher than those in other studies. BMI, body fat, vitamin A and zinc intake had a significant correlation with LS-BMD. Femur, PTH, body fat, vitamin A, vitamin B$_2$and calcium intake had a significant correlation with WT-BMD and was mostly influenced by diet. By multiple regression analysis, it was shown that the significant factors affecting the LS-BMD were BMI and vitamin A intake and those affecting FN and WT were age, BMI, PTH and calcium intake. These results indicate that some Korean women still experience increases in BMD and that this was associated with PTH and vitamin A and calcium intake. Therefore, proper diet and diet management is needed to increase changes in BMD among college women.

Rheological Properties of Dandelion Root Concentrates by Extraction Solvents

  • Lee, Ok-Hwan;Kang, Suk-Nam;Lee, Boo-Yong
    • Food Science and Biotechnology
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    • v.15 no.1
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    • pp.33-38
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    • 2006
  • This study was performed to provide basic rheological data of dandelion root concentrates in order to predict their processing aptitude and usefulness as functional foods material. The hot water and 70% ethanol extracts of dandelion root were concentrated at 5, 20, and 50 Brix, and their static viscosity, dynamic viscosity, and Arrhenius plots were investigated. Almost all hot water concentrates showed the typical flow properties of a pseudoplastic fluid, but evaluation using the power law model indicated that the 70% ethanol concentrates showed a flow behavior close to a Newtonian fluid. The apparent viscosity of hot water and 70% ethanol concentrates decreased with increasing temperature. Yield stresses of hot water and 70% ethanol concentrates by Herschel-Bulkley model application were in the range of 0.026 - 1.368 Pa and 0.022 - 0.238 Pa, respectively. The effect of temperature and concentration on the apparent viscosity was examined by Arrhenius equation. The activation energies of hot water and 70% ethanol concentrates were in the range of $8.762-23.778{\times}10^3\;J/mol{\cdot}kg$ and $3.217-20.384{\times}10^3\;J/mol{\cdot}kg$ with increasing concentration, respectively. Storage (G') and loss (G") moduli were generally increased with increasing frequency. For the 70% ethanol concentrates, G" predominated over G' at all applied frequencies and so they showed the typical flow behavior of a low molecular solution. However, for the hot water concentrates, G' predominated over G" at more than 1.9 rad/sec (cross-over point) and so they showed the typical flow behavior of a macromolecular solution.

Comparisons of Imputation Methods for Wave Nonresponse in Panel Surveys (패널조사 웨이브 무응답의 대체방법 비교)

  • Kim, Kyu-Seong;Park, In-Ho
    • Survey Research
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    • v.11 no.1
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    • pp.1-18
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    • 2010
  • We compare various imputation methods for compensating wave nonresponse that are commonly adopted in many panel surveys. Unlike the cross-sectional survey, the panel survey is involved a time-effect in nonresponse in a sense that nonresponse may happen for some but not all waves. Thus, responses in neighboring waves can be used as powerful predictors for imputing wave nonresponse such as in longitudinal regression imputation, carry-over imputation, nearest neighborhood regression imputation and row-column imputation method. For comparison, we carry out a simulation study on a few income data from the Korean Welfare Panel Study based on two performance criteria: predictive accuracy and estimation accuracy. Our simulation shows that the ratio and row-column imputation methods are much more effective in terms of both criteria. Regression, longitudinal regression and carry-over imputation methods performed better in predictive accuracy, but less in estimation accuracy. On the other hand, nearest neighborhood, nearest neighbor regression and hot-deck imputation show higher performance in estimation accuracy but lower predictive accuracy. Finally, the mean imputation shows much lower performance in both criteria.

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Change of forward Head Posture in Cervical Flexion Positions while Watching Video on a Smartphone (스마트폰을 이용한 비디오 시청 시, 목뼈 굽힘 각도에 따른 앞쪽 머리 자세의 변화)

  • Bo ram Choi
    • Journal of Korean Physical Therapy Science
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    • v.30 no.3
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    • pp.23-30
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    • 2023
  • Background: Flexion of cervical and lumbar joints is required when viewing a smartphone screen. Thus, these joints are overused, together with the surrounding joints and muscles. Long-term use of smartphones will cause changes in cervical and lumbar posture. The effect on forward head posture will vary, depending on the angle of cervical flexion start position in relation to the smartphone. This study investigated how forward head posture changes over time when using a smartphone at 20° and 40° cervical flexion start positions. Design: Cross-sectional study. Methods: Twenty-five subjects with a forward head posture angle of 35° or less participated in the study. A Forward Head Posture app on the participants' smartphones measured forward head posture 5 and 10 minutes after watching videos on their smartphones. Cervical range of motion was used to set a smartphone watching start posture of 20° and 40° of cervical flexion. Results: There was no significant difference in forward head posture, irrespective of cervical flexion start position, but the angle of forward head posture increased more at cervical flexion of 40° than at cervical flexion of 20°. There was no significant difference in what according to smartphone video viewing times, but the angle of forward head posture increased over time. Conclusion: An increase in forward head posture over time with smartphone usage poses a potential risk of neck and shoulder pain. Therefore, smartphone users should avoid prolonged screen time.