• Title/Summary/Keyword: Variance of Analysis

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Association of periodontitis with menopause and hormone replacement therapy: a hospital cohort study using a common data model

  • Ki-Yeol Park ;Min-Ho Kim;Seong-Ho Choi;Eun-Kyoung Pang
    • Journal of Periodontal and Implant Science
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    • v.53 no.3
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    • pp.184-193
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    • 2023
  • Purpose: The present study was designed to compare the incidence of periodontitis according to menopausal status and to investigate the possible effect of hormone replacement therapy (HRT) on periodontitis in postmenopausal women using a common data model (CDM) at a single institution. Methods: This study involved retrospective cohort data of 950,751 patients from a 20-year database (2001 to 2020) of Ewha Womans University Mokdong Hospital converted to the Observational Medical Outcomes Partnership CDM. One-way analysis of variance models and the χ2 test were used to analyze the statistical differences in patient characteristics among groups. A time-dependent Cox regression analysis was used to calculate hazard ratios and 95% confidence intervals, and P values less than 0.05 were considered to indicate statistical significance. Results: Of the 29,729 patients, 1,307 patients were diagnosed with periodontitis and 28,422 patients were not. Periodontitis was significantly more common among postmenopausal patients regardless of HRT status than among the non-menopausal group (P<0.05). Time-dependent Cox regression analysis showed that the postmenopausal patients had a significantly higher chance of having periodontitis than non-menopausal patients (P<0.05), but after adjustment for age, body mass index, and smoking status, the difference between the non-menopausal and post-menopausal HRT-treated groups was insignificant (P=0.140). Conclusions: Postmenopausal women had a significantly greater risk of periodontitis than non-menopausal women. Additionally, the use of HRT in postmenopausal women could reduce the incidence of periodontitis.

The level of food literacy and its association with food intake and obesity status among Seoul citizens: results from Seoul Food Survey 2021

  • Hyelim Yoo;Eunbin Jo;Hyeongyeong Lee;Eunji Ko;Eunjin Jang;Jiwon Sim;Kirang Kim;Sohyun Park
    • Nutrition Research and Practice
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    • v.17 no.5
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    • pp.945-958
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    • 2023
  • BACKGROUND/OBJECTIVES: Food literacy (FL) is a crucial skill for selecting sustainable and healthy food options, necessitating the identification of vulnerable groups in the community using valid measurement tools. Identifying weak domains in FL is essential for enhancing the overall FL. This study examined the FL levels of Seoul citizens based on their sociodemographic characteristics and assessed the relationship between FL, food intake, and weight status. SUBJECTS/METHODS: This study utilized the data from the Seoul Food Survey, a cross-sectional study employing representative samples of Seoul citizens. Data collection occurred from September to October 2021, with 4,039 citizens aged 18 yrs and above participating in face-to-face surveys. Thirty-three FL items were assessed, comprising 14 items in the nutrition and safety (NS) domain, eight items in the cultural and relational (CR) domain, and 11 items in the socio-ecological (SE) domain. In addition, data on food intake sufficiency and obesity status were collected. The descriptive statistics, t-tests, analysis of variance, and logistic regression analysis were used for analysis. RESULTS: Men, students, young adults, older citizens, and people experiencing food insecurity had the lowest scores for all the FL domains. The highest quartile group of NS scores had a higher probability of consuming adequate servings of vegetables and fruits, with significant linear trends observed (P for trend < 0.05). In all three FL domains, the odds ratio for obesity was significantly lower in the groups with high FL scores (P < 0.05). CONCLUSIONS: A close relationship was observed between low FL, obesity, and food intake, even after controlling for other covariates. Vulnerable groups with low FL were also identified. Therefore, it is essential to develop programs to improve FL and the health and well-being of these groups.

Univariate and Multivariate Analysis of Phenotypic Traits in Mung Beans Reveals Diversity Among Korean, Indian, and Chinese Accessions

  • Kebede Taye Desta;Young-ah Jeon;Myoung-Jae Shin;Yu-Mi Choi;Jungyoon Yi;Hyemyeong Yoon
    • Korean Journal of Plant Resources
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    • v.37 no.3
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    • pp.270-306
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    • 2024
  • This study investigated the diversity of 323 mung bean accessions from Korea, China, and India, along with six cultivars, using 22 agronomical traits. The standardized Shannon-Weaver index (H') for the qualitative traits ranged from 0.11 (terminal leaflet shape) to 0.98 (pubescence density of pod). Likewise, the coefficient of variation for the quantitative traits ranged from 8.76% (days to maturity (DM)) to 79.91% (lodging rate (LR)), indicating a wide genetic variance. Hypocotyl color, pod color, seed shape, and seed coat surface lust showed different distributions among Korean, Indian, and Chinese accessions. Chinese accessions had the highest average germination rate, DM, days from flowering to maturity, and one-hundred seeds weight, followed by Korean and Indian accessions, while the number of seeds per pod (SPP) displayed the opposite trend, with all except SPP showing significant variation (p < 0.05). Similarly, plant height, days to flowering, and number of pods per plant increased in the order of India > Korea > China, with LR showing the opposite trend (p < 0.05). The mung bean accessions were grouped into four major clusters using hierarchical cluster analysis supported by principal component analyses, and all of the quantitative traits showed significant variations between the clusters (p < 0.05). Generally, the mung bean accessions investigated in this study exhibited wide phenotypic trait variations, which could be beneficial for future genomics studies. Moreover, this study identified 77 accessions that outperformed the controls. Consequently, these superior accessions could provide a wide spectrum of options during the development of improved mung bean varieties.

Study on Singular Value Decomposition Signal Processing Techniques for Improving Side Channel Analysis (부채널 분석 성능향상을 위한 특이값분해 신호처리 기법에 관한 연구)

  • Bak, Geonmin;Kim, Taewon;Kim, HeeSeok;Hong, Seokhie
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.26 no.6
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    • pp.1461-1470
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    • 2016
  • In side channel analysis, signal processing techniques can be used as preprocessing to enhance the efficiency and performance of analysis by reducing the noise or compressing the dimension. As signal processing techiniques using singular value decomposition can increase the information of main signal and reduce the noise by using the variance and tendency of signal, it is a great help to improve the performance of analysis. Typical techniques of that are PCA(Principal Component Analysis), LDA(Linear Discriminant Analysis) and SSA(Singular Spectrum Analysis). PCA and LDA can compress the dimension with increasing the information of main signal, and SSA reduces the noise by decomposing the signal into main siganl and noise. When applying each one or combination of these techniques, it is necessary to compare the performance. Therefore, it needs to suggest methodology of that. In this paper, we compare the performance of the three technique and propose using Sinal-to-Noise Ratio(SNR) as the methodology. Through the proposed methodology and various experiments, we confirm the performance and efficiency of each technique. This will provide useful information to many researchers in the field of side channel analysis.

Optimization of Culture Medium for Lactosucrose ($^4G-{\beta}$-D-Galactosylsucrose) Production by Sterigmatomyces elviae Mutant Using Statistical Analysis

  • Lee, Jong-Ho;Lim, Jung-Soo;Song, Yoon-Seok;Kang, Seong-Woo;Prak, Chul-Hwan;Kim, Seung-Wook
    • Journal of Microbiology and Biotechnology
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    • v.17 no.12
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    • pp.1996-2004
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    • 2007
  • In this study, the optimization of culture medium using a Sterigmatomyces elviae mutant was investigated using statistical analysis to increase the cell mass and lactosucrose ($^4G-{\beta}$-D-galactosylsucrose) production. In basal medium, the cell mass and lactosucrose production were 4.12 g/l and 140.91 g/l, respectively. However, because of the low cell mass and lactosucrose production, optimization of culture medium was carried out to increase the cell mass and lactosucrose production. Culture media were optimized by the S. elviae mutant using analysis of variance (ANOVA) and response surface methodology (RSM). Central composite designs using RSM were utilized in this investigation. Quadratic models were obtained for cell mass and lactosucrose production. In the case of cell mass, optimal components of the medium were as follows: sucrose 1.13%, yeast extract 0.99%, bactopeptone 2.96%, and ammonium sulfate 0.40%. The predicted maximum value of cell mass was about 5.20 g/l and its experimental value was 5.08 g/l. In the case of lactosucrose production, optimal components of the medium were as follows: sucrose 0.96%, yeast extract 1.2%, bactopeptone 3.0%, and ammonium sulfate 0.48%. Then, the predicted maximum value of lactosucrose production was about 194.12 g/l and the corresponding experimental value was about 183.78 g/l. Therefore, by culturing using predicted conditions, the real cell mass and lactosucrose production increased to 23.3% and 30.42%, respectively.

Effects of Policy and Environmental Characteristics of University on Drinking Problems among University Students (대학교 음주관련 정책 환경이 대학생 음주문제에 미친 영향)

  • Kim, Kwang-Kee;JeKarl, Jung;Lee, Ki-Il;Park, Jung-Eun
    • Korean Journal of Health Education and Promotion
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    • v.29 no.2
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    • pp.83-91
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    • 2012
  • Objectives: This study is to examine that drinking problems among university students were accounted for not only by student's individual characteristics but alcohol policy and environmental characteristics of the university in which students were enrolled. Method: Secondary data analysis was employed in which variables under study were derived from a raw data of a nationwide representative sample in 2009. Raw data under analysis included 3,665 students from 63 universities across Korea. Organizational and environmental characteristics of the university were collected from university administrators while individual characteristics and drinking behavior from the students in using self-administrated questionnaire. Multilevel regression analyses were employed to describe alcohol policy effects on students's drinking problems measured by AUDIT by using HLM7.0. Results: ICCs indicate that variation in drinking problem depends on alcohol policy of university. Multilevel regression models identified statistically significant factors in explaining variance of drinking problems. Group means on drinking problem are affected by indicators representing alcohol policy with level of drinking problem of student being decreased in accordance to level of availability of alcohol on campus. Conclusions: It is concluded that drinking problems among university students were associated with both individual characteristics and alcohol policy of the university they enrolled. This study supports policy belief that interventions at environmental as well as individual level are required to prevent drinking problem among university students.

Factors Influencing Physical Activity among Community-dwelling Older Adults with Type 2 Diabetes: A Path Analysis (지역사회에 거주하는 제2형 당뇨병 노인의 신체활동에 영향을 미치는 요인: 경로분석)

  • Jang, Sun Joo;Park, Hyunju;Kim, Hyunjung;Chang, Sun Ju
    • Journal of Korean Academy of Nursing
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    • v.45 no.3
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    • pp.329-336
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    • 2015
  • Purpose: The purpose of the study was to identify factors influencing physical activity among community-dwelling older adults with type 2 diabetes. The study design was based on the Theory of Triadic Influence. Methods: A total of 242 older adults with type 2 diabetes participated in this study. Six variables related to physical activity in older adults, including self-efficacy, social normative belief, attitudes, intention, experience, and level of physical activity, were measured using reliable instruments. Data were analyzed using descriptive statistics, Pearson's correlation analyses, and a path analysis. Results: The mean physical activity score was 104.2, range from zero to 381.21. The path analysis showed that self-efficacy had the greatest total effect on physical activity. Also, experience had direct and total effects on physical activity as well as mediated the paths of social normative beliefs to attitudes and intention to physical activity. These factors accounted for 10% of the total variance, and the fit indices of the model satisfied the criteria of fitness. Conclusion: The findings of the study reveal the important role of self-efficacy and past experience in physical activity in older adults with type 2 diabetes.

Evaluation for anaerobic germinability of rice germplasm for direct-seeding cultivation under submerged conditions

  • Rauf, Muhammad;Choi, Yu-Mi;Lee, Sukyeung;Lee, Myung-Chul;Oh, Sejong;Hyun, Do Yoon
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.71-71
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    • 2017
  • Stable stand establishment is pre-requisite in direct rice seeding system for obtaining optimal yield of rice crop in rain-fed and waterlogged areas. Anaerobic condition on waterlogged soil causes low germination which significantly reduces crop yield. Due to low availability of tolerant genetic material for anaerobic germination, there is urgent need to evaluate rice germplasm for better germinability under anaerobic conditions. Seeds of the 185 rice accessions were evaluated for germination vigor and coleoptile length under anaerobic conditions. The variation among germplasm was tested for significance using analysis of variance and various multivariate components. Significant level of variation was observed among all accessions for germination vigor and coleoptiles length. Although highest mean values for coleoptiles length (2.1cm) and germination rate (60%) were observed in japonica accessions but maximum coleoptile length (4.68cm) and germination rate (96%) was found in indica genotype CO18. A highly significant and positive correlation was also observed between germination vigor and coleoptiles length, which signify the importance of elongated coleoptile under anaerobic conditions. The PCA analysis illustrated that 97.24% variation was accounted by PC1 while PC2 and PC3 explained 2.54% and 0.24% variation for germination vigor and coleoptile length. PCA scattered plot divided the accessions in four various groups. All AG tolerant accessions were included in group I. Likewise in the case of cluster analysis, two major clades (I and II) were formed. All accessions showing >40% germination rate were included in clade I, whereas all other accessions with <40% germination rate were grouped in clade II. Further more highly tolerant accessions (>80% germination) were grouped in sub-cluster IA.

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A Study of Variables Related to Item Difficulty in College Scholastic Ability Test (대학수학능력시험 난이도 관련 변인 탐색)

  • 박문환
    • Journal of Educational Research in Mathematics
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    • v.14 no.1
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    • pp.71-88
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    • 2004
  • The purpose of this study was to examine particular variables that play a significant role in the difficulty of math test items in College Scholastic Ability Test (CSAT). The study also aimed to develop a model of measuring the item difficulty. Variables correlated to item difficulty were drawn from the review of the related literature and the analysis of the content and difficulty of the past test items of CSAT. The first instrument was designed by using the correlated variables. According to the results of correlation analysis, the second instrument was made by deleting the variables which showed relatively low correlation with item difficulty and by refining some variables. Several models were proposed by using the revised instrument. The comparison of the R square and cross validity of each model reveals that integrated regression model was the most stable and accurate among the proposed models. The study also showed that statistically significant predictors were choice format, content domain, behavior domain, and the degree of item familiarity in the order of proportion of variance accounted by the predictors. Despite the limited scope of the present research, it can be suggested that its findings provide useful insights into predicting math test item difficulty.

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The Relationship between Clothing Behavior and Perceptual Orientation of Korean High School Boys (남자 중$\cdot$고등학생의 의복행동과 지각향성과의 상관연구 -의복의 동조성을 중심으로-)

  • Chung Mi Sil;Kahng Hewon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.8 no.1
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    • pp.21-27
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    • 1984
  • The purpose of this study was to investigate the relationship between perceptual orientation and four aspects of clothing behavior. Perceptual orientation was measured with Choi's Perceptual Orientation Scale, and clothing satisfaction was assessed with Lim and Lee questionnaire. Clothing importance was measured with some items of Kirby's Clothing Attitudes and additional items prepared for this study, Clothing comfort was measured Ivith some items of Creekmore Scales of Eight Clothing Variables and additional items prepared for this study. Clothing conformity was measured by some items of Selker's The Clothing Conformity Inventory and Carpenter's Clothing Opinion Scale and the Kim questionnaire, along with additional items for this study. Altogether 43 items were used. The questionnaire was completed by 480 second year junior and senior high school boys in Seoul. Statistical analysis was performed using the correlation coefficient, t-tests, multiple regression analysis, and analysis of variance. The results were : 1) Perceptual orientation was positively related to clothing satisfaction. 2) Perceptual orientation was negatively related to clothing conformity. 3) Scores of senior high school boys on self-perception and total perception were significantly higher than these of junior high school boys. 4) Clothing satisfaction, clothing conformity and clothing importance were different according to the grade level. That is, junior high school boys had a higher clothing satisfaction ana senior high school boys had a higher clothing conformity and clothing importance score.

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