• Title/Summary/Keyword: Multiple-Regression

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Parents' Satisfaction on Foodservice Quality of Kindergartens in Chungbuk Province (충북지역 유치원 급식품질에 대한 학부모 만족도)

  • Lee, Joo-Young;Lee, Young-Eun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.39 no.4
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    • pp.613-623
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    • 2010
  • The purpose of this study was to examine parents' perceptions towards the importance and performance levels of foodservices quality at kindergartens. The questionnaire was developed to measure the thirty-one quality attributes of foodservice operations. A questionnaire survey was conducted to 500 parents and the return rates were 62.4%. The survey period was from July 15 to August 8, 2008. The parents had a high level of perception toward the need for foodservice, earning 4.46 points out of 5 point. Their perceptions of foodservice quality were examined by six dimensions of importance and performance level. While the parents gave 4 points or greater of 5 points to most quality attributes of importance level, they gave 4 points or less out of 5 points to most quality attributes of performance level. As for the importance and performance level of the quality dimensions of foodservice, parents regarded sanitation as the most important dimension. IPA showed that 'ventilation', 'sanitation of tableware' and 'sanitation of dining tables and chairs' were included as 'focus' areas. The overall satisfaction level for foodservice was 3.74 out of 5 points A higher level of satisfaction was shown at self-operated foodservice system of kindergartens. According to multiple regression analysis, 46.3% of the variance in the respondents' overall satisfaction scores was explained by factors such as food, menu and price, facilities, sanitation, atmosphere and foodservice effects.

Association between Bone Mineral Density and Bone Nutrition Indicators in Elderly Residing in Low Income Area of the City (도시거주 저소득층 노인들의 골지표 및 영양소섭취와 골밀도와의 상관관계에 관한 연구)

  • 손숙미;전예나
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.1
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    • pp.107-113
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    • 2004
  • This study explored the association between the bone nutrition indicators and the bone mineral density (BMD) in 138 apparently healthy elderly (male: 38, female: 100) dwelling in a low income area of the city. Dietary intakes were estimated from two meals (breakfast & dinner) and snack using 24 hr-recall method and lunch with weighing over 3 consecutive days. Female elderly showed significant lower intakes (p<0.001∼p<0-05) for most of the nutrients except calcium and vitamin C than the elderly male. Calcium and vitamin D intakes for both male and female were 331.0 mg, 1.89 $\mu\textrm{g}$ and 308.6 mg, 1.21 $\mu\textrm{g}$, respectively and they were below the 50% of the RDA. Both the BMDs at lumbar spine (LS) and femoral neck (FN) were positively correlated with the energy intake, calcium intake and vitamin D intake (p<0.05, respectively) for male. In female BMDs of the both sites were positively correlated with the intakes of carbohydrates, protein, lipid, calcium and vitamin D (p<0.01∼p<0.05). Female showed higher serum osteocalcin (p<0.01) and urinary deoxypyridinoline/creatinine (DPYR/CR) (p<0.001), meaning that female had elevated rate in bone turn over and bone resorption. The proportion of subjects with vitamin D deficiency assessed with serum 25(OH)VitD$_3$<10 mg/mL was 35.0% for female and 23.7% for male, respectively Both the BMDs at lumbar spine and trochanter were positively correlated with serum 25(OH)VitD$_3$ but BMDs in most of the sites were negatively associated with urinary DPYR/CR, phosphate/CR. Stepwise multiple regression showed physical activity, serum alkaline phosphatase, weight, vitamin D explained 47.6% of the variation of the LS BMD. The indicator variable for serum alkaline phosphatase was negatively associated with LS BMD. However, the indicator variable for weight and vitamin D intake were positive and significant (p=0.0087, p=0.0007, respectively). For FN BMD, the indicator variable for age and serum alkaline phosphatase were negative and significant (p<0.0075, p<0.0015, respectively) and the weight was positively associated with the FN BMD.

Influences of Firm Characteristics and the Host Country Environment on the Degree of Foreign Market Involvement (기업특성과 호스트국가 환경이 해외시장 관여도에 미치는 영향에 관한 연구)

  • Maktoba, Omar;Nwankwo, Sonny
    • Journal of Global Scholars of Marketing Science
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    • v.19 no.2
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    • pp.5-16
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    • 2009
  • Against the backdrop of the increasing trend towards economic globalisation, many international firms are indicating that decisions on how to enter foreign markets remains one of the key strategic challenges confronting them. Despite the rich body of literature on the topic, the fact that these challenges have continued to dominate global marketing strategy discourses point to someevident lacunae. Accordingly, this paper considers the variables, categorised in terms of firm contexts (standardisation, market research, competition, structure, competitive advantage) and host country-contexts (economic development, cultural differences, regulation and political risk), which influence the degree of involvement of UK companies in overseas markets. Following hypotheses were drawn from literature review: H1: The greater the level of competition, the higher the degree of involvement in the overseas market. H2: The more centralised the firm's organisation structure, the higher the degree of involvement in the overseas market. H3a: The adoption of a low cost-approach to competitive advantage will lead to a higher degree of involvement. H3b: The adoption of an innovation-approach to competitive advantage will lead to a higher degree of involvement. H3c: The adoption of a market research approach to competitive advantages will lead to a higher degree of involvement. H3d: The adoption of a breadth of strategic target-approach to competitive advantage will lead to a lower degree of involvement. H4: The higher the degree of standardisation of the international marketing mix the higher the degree of involvement. H5: The greater the degree of economic development in the host market, the higher the degree of involvement. H6: The greater the cultural differences between home and host countries, the lower the degree of involvement. H7: The greater the difference in regulations between the home country and the host country, the lower the degree of involvement. H8: The higher the political risk in the host country, the lower the degree of involvement. A questionnaire instrument was constructed using, wherever possible, validated measures of the concepts to serve the aims of this study. Following two sets of mailings, 112 usable completed questionnaires were returned. Correlation analysis and multiple regression analysis were used to analyze data. Statistically, the paper suggests that factors relating to the level of competition, competitive advantages and economic development are strong in influencing foreign market involvements. On the other hand, unexpectedly, cultural factors (especially individualism/collectivism and low and high power distance dimensions) proved to have weak moderating effects. The reason for this, in part, is due to the pervading forces of globalisation and the attendant effect on global marketing. This paper has contributed to the general literature in a way that point to two mainimplications. First, with respect to research on national systems, the study may hold out some important lessons especially for developing nations. Most of these nations are known to be actively seeking to understand what it takes to attract foreign direct investment, expand domestic market and move their economies from the margin to the mainstream global economy. Second, it should be realised that competitive conditions remain in constant flux (even in mature industries and mature economies). This implies that a range of home country factors may be as important as host country factors in explaining firms' strategic moves and the degree of foreign market involvement. Further research can consider the impact of the home country environment on foreign market involvement decisions. Such an investigation will potentially provide further perspectives not only on the influence of national origin but also how home country effects are confounded with industry effects.

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Building battery deterioration prediction model using real field data (머신러닝 기법을 이용한 납축전지 열화 예측 모델 개발)

  • Choi, Keunho;Kim, Gunwoo
    • Journal of Intelligence and Information Systems
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    • v.24 no.2
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    • pp.243-264
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    • 2018
  • Although the worldwide battery market is recently spurring the development of lithium secondary battery, lead acid batteries (rechargeable batteries) which have good-performance and can be reused are consumed in a wide range of industry fields. However, lead-acid batteries have a serious problem in that deterioration of a battery makes progress quickly in the presence of that degradation of only one cell among several cells which is packed in a battery begins. To overcome this problem, previous researches have attempted to identify the mechanism of deterioration of a battery in many ways. However, most of previous researches have used data obtained in a laboratory to analyze the mechanism of deterioration of a battery but not used data obtained in a real world. The usage of real data can increase the feasibility and the applicability of the findings of a research. Therefore, this study aims to develop a model which predicts the battery deterioration using data obtained in real world. To this end, we collected data which presents change of battery state by attaching sensors enabling to monitor the battery condition in real time to dozens of golf carts operated in the real golf field. As a result, total 16,883 samples were obtained. And then, we developed a model which predicts a precursor phenomenon representing deterioration of a battery by analyzing the data collected from the sensors using machine learning techniques. As initial independent variables, we used 1) inbound time of a cart, 2) outbound time of a cart, 3) duration(from outbound time to charge time), 4) charge amount, 5) used amount, 6) charge efficiency, 7) lowest temperature of battery cell 1 to 6, 8) lowest voltage of battery cell 1 to 6, 9) highest voltage of battery cell 1 to 6, 10) voltage of battery cell 1 to 6 at the beginning of operation, 11) voltage of battery cell 1 to 6 at the end of charge, 12) used amount of battery cell 1 to 6 during operation, 13) used amount of battery during operation(Max-Min), 14) duration of battery use, and 15) highest current during operation. Since the values of the independent variables, lowest temperature of battery cell 1 to 6, lowest voltage of battery cell 1 to 6, highest voltage of battery cell 1 to 6, voltage of battery cell 1 to 6 at the beginning of operation, voltage of battery cell 1 to 6 at the end of charge, and used amount of battery cell 1 to 6 during operation are similar to that of each battery cell, we conducted principal component analysis using verimax orthogonal rotation in order to mitigate the multiple collinearity problem. According to the results, we made new variables by averaging the values of independent variables clustered together, and used them as final independent variables instead of origin variables, thereby reducing the dimension. We used decision tree, logistic regression, Bayesian network as algorithms for building prediction models. And also, we built prediction models using the bagging of each of them, the boosting of each of them, and RandomForest. Experimental results show that the prediction model using the bagging of decision tree yields the best accuracy of 89.3923%. This study has some limitations in that the additional variables which affect the deterioration of battery such as weather (temperature, humidity) and driving habits, did not considered, therefore, we would like to consider the them in the future research. However, the battery deterioration prediction model proposed in the present study is expected to enable effective and efficient management of battery used in the real filed by dramatically and to reduce the cost caused by not detecting battery deterioration accordingly.

The Association between Vinyl House Work and Low Back Pain among Some Rural Residents (일부 농촌지역주민의 비닐하우스 작업여부와 요통과의 관련성)

  • Kim, Kwi-Nam;Ryu, So-Yeon;Park, Jong;Lee, Jun-Haeng;Kim, Ki-Soon
    • Journal of agricultural medicine and community health
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    • v.24 no.1
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    • pp.145-159
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    • 1999
  • To find the association, between vinyl house work and the prevalence of low back pain, a questionnaire survey was made toward 215 vinyl house farmers and 228 general farmers without vinyl house who are cared by Jungjung Community health Practioners at Soobuk Myun, Damyang-gun, Chollanamdo. 1. Vinyl house farmers were significantly younger in age, higher in educational status higher survival rate of spouse, higher economic state and less cared by medical aid than general farmers. 2. Vinyl house farmers showed shorter career for agricultural work, used modern farming instrument more frequently and worked with sitting position. 3. During unbusy season in general agriculture, vinyl house farmers consumed significantly more time in agricultural work and general activity, but no significant difference of time of the above activity among busy season. 4. During the last spring season when most vinyl house work was performed, vinyl house farmers showed significantly higher prevalence of low back pain than general farmers, but no significant difference of prevalence among the two groups for the last one week. 5. By the simple analysis statistical significant related variables with low back pain was found to be sex(p<0.001), educational status(p<0.05), work posture(p<0.001) and use of modern agricultural machine(p<0.05). 6. By the multiple logistic regression the odds ratio for low back pain among vinyl house farmers were 2.08(95% confidence interval 1.31-3.00) compared to general farmers, the odds ratio among female was 2.35(95% confidence interval 1.24-4.47) to male, the odds ratio among illiterate persons were 2.60(95% confidence interval 1.24-4.47) to high school graduate, and the odds ration among primary school graduate was 2.19(95% confidence interval 1.04-4.47) to high school graduate. In conclusion because vinyl house farmers showed significantly higher rates of low back pain compared to farmers without vinyl house, continuous study to find the true cause of low back pain among vinyl-house farmers and active effort to prevent low back pain are necessary.

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Prevalence of Urinary Incontinence and Its Related Factors among the Rural Residing Elderlies (일부 농촌지역 노인들의 요실금 유병률과 관련요인)

  • Yoon, Hyun-Suk;Kwon, In-Sun;Bae, Nam-Kyou;Cho, Young-Chae
    • Journal of agricultural medicine and community health
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    • v.34 no.1
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    • pp.76-86
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    • 2009
  • Objectives: This study was conducted to find out the frequency of urinary incontinence among the rural elderly people and its related factors. Methods: Informations have been obtained through interviews from the 464 rural residents of advanced age over 65 years on September 1st through November 30th, 2007, in Chungnam Province. Results: As for the rate of experiencing urinary incontinence, the group with the experience rate of 「every day」 were 9.5% and 「occasionally」 35.5%, with the total of 45.0%. The higher rates of urinary incontinence were in the elderly women(58.5%) than in the elderly men (29.8%), in the more advanced in age, in the higher educated, and in the groups with higher monthly income. Based on life styles, the rate of experiencing urinary incontinence was significantly higher in smoking groups and non-drinking groups. Based on subjective senses of health, it was more highly associated with the groups who reported that they were not healthy, that they concerned themselves about health, that they had physical disability, that they had forgetfulness, and they needed assistance in terms of activity of daily living(ADL) and instrumental activity of daily living(IADL) than their respective counterparts. By the result of multiple logistic regression, sex, age, smoking status, anxiety, physical disability, amnesia, and IADL was indicated the affecting factors to the prevalence of urinary incontinence. Conclusions: The above results reveal that the rate of urinary incontinence was higher in the elderly women than the elderly men, and in more advanced age. Moreover, its rate increases in the groups with undesirable life styles or lower senses of subjective and physical health conditions. It is highly suggested that efforts to manage urinary incontinence of the elderly need to be narrowed to the more advanced, especially those with lower standards of health conditions.

Associations between the Practice of Health Behaviors and Awareness of Metabolic Syndrome among Adults (19-64 years) in the Gwangju-Jeonnam Area: 2010 Community Health Survey (광주 전남지역 성인의(19-64세) 건강생활실천과 대사증후군 인지와의 관련성 - 2010년 지역사회건강조사 자료를 이용하여 -)

  • Chun, In Ae;Ryu, So Yeon;Park, Hyeon Hui;Park, Jong;Han, Mi Ah;Choi, Seong Woo
    • Journal of agricultural medicine and community health
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    • v.38 no.4
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    • pp.217-228
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    • 2013
  • Objective: This study was performed to identify associations between the practice of health behaviors and awareness of metabolic syndrome (MetS) among adults aged 19 to 64 years in the Gwangju-Jeonnam area. Methods: This study utilized data from the 2010 Community Health Survey (CHS). Health behaviors considered in this study were smoking, alcohol drinking, physical activity, low-salt diet, and perception of stress. The index for the health behaviors was calculated as the sum of the practice of each health behavior (range: 0-5). The analysis was weighted with a complex sampling design, and the chi-square test and multiple logistic regression analysis were used to identify the association between the practice of health behaviors and awareness of MetS. Results: A total of 19.8% of the population were aware of MetS. The perception of MetS was statistically significantly associated with healthy behaviors, including nonsmoking (aOR = 1.33, 95% CI = 1.14-1.56), non-high-risk drinking (aOR = 1.54, 95% CI = 1.27-1.88), engagement in physical activity (aOR = 1.48, 95% CI = 1.28-1.72), and a low-salt diet (aOR = 1.30, 95% CI = 1.13-1.51). The ORs of the perception of MetS were significantly higher in patients with a health behavior index of 2 to 3 (aOR = 1.64, 95% CI = 1.01-2.66) and in those with an index of ${\geq}4$ (aOR = 2.47, 95% CI = 1.51-4.04) than in those with an index of 0. Among all health behaviors, physical activity had the highest OR for the perception of MetS (aOR = 1.50, 95% CI = 1.29-1.74). Conclusions: This study revealed associations between health behaviors, especially physical activity, and awareness of MetS. Therefore, integrated health promotion programs may be needed to enhance awareness of MetS and to effectively prevent MetS and non-communicable diseases.

Association between Quality of Life and Eveningness as well as Sleep Quality among Medical Students (의대의학전문대학원 학생들의 삶의 질과 일주기 리듬 및 수면의 질과의 연관성)

  • Chang, Hong-Kyeung;Lee, So-Jin;Park, Chul-Soo;Kim, Bong-Jo;Lee, Cheol-Soon;Cha, Boseok;Lee, Dongyun;Seo, Ji-Yeong
    • Sleep Medicine and Psychophysiology
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    • v.22 no.2
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    • pp.64-69
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    • 2015
  • Objectives: We investigated whether sleep behaviors, severity of insomnia and circadian typology are associated with quality of life among Gyeongsang National University (GNU) medical students. Methods: Questionnaires were distributed to 46 fourth-year students of GNU Medical School. The hospital anxiety-depression scale, insomnia severity index (ISI), morningness-eveningness questionnaire (MEQ) and WHO Quality of Life-BREF (WHOQOL-BREF) were used. Results: Quality of life in terms of physical health was associated with age, weekday total sleep time (TST), weekend TST, catch up sleep, depression, ISI score, and MEQ score. Quality of life in terms of psychological health was correlated to weekday and weekend TST, anxiety, ISI score and MEQ score. Sex, weekday TST, depression, and ISI score were revealed to influence the social aspect of quality of life, and weekday and weekend TST, and ISI score were associated with quality of life in terms of environment. Multiple regression analysis showed that better sleep quality predicted to a higher quality of life in terms of physical, psychological and environmental health, and eveningness was associated with a better quality of life in terms of physical and psychological health. Conclusion: It is concluded that physical, psychological, and environmental aspects of quality of life were associated with quality of sleep and that physical and psychological aspects of quality of life were related to eveningness in GNU medical students. Therefore, it is equally important to treat emotional problem as well as improve sleep quality.

AGE ESTIMATION USING PANORAMIC RADIOGRAPHS OF DEVELOPING PERMANENT TEETH (발육중인 영구치의 파노라마 방사선 사진 계측을 이용한 연령 추정)

  • Choi, Eun-Young;Choi, Nam-Ki;Kim, Seon-Mi;Yang, Kyu-Ho
    • Journal of the korean academy of Pediatric Dentistry
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    • v.34 no.2
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    • pp.215-221
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    • 2007
  • The aim of this study was to test whether metric measurements of crown length, root length and apex width during tooth development could be a better basis for correlation with age than the classical methods based on subjective estimations of various stages of tooth development. Panoramic radiographs of 120 children, aged 7 to 9 years, were collected from the department of the pediatric dentistry of Chonnam National University Hospital, Korea. The methods of Mornstad was used to estimate age. The structures measured were crown length root length and apex width in panoramic radiographic. The results were as follows : 1. In the boys, it showed higher correlation between lower 2nd molar crown length, lower 1st molar root length or lower 1st permolar apical width and age. In the girls, it showed higher correlation between lower 2nd premolar crown length, lower 2nd molar root length or lower 1st molar apical width and age. 2. With the aid of a multiple regression model, a linear relationship between some of these distances and age was shown. Boy(months) = 43.958 + lower 2nd molar crown length ${\times}$ 4.392 + lower 1st molar root length ${\times}$ 2.255 - lower 1st permolar apical width ${\times}$ 2.046, Girl(months) = 75.213 + lower 2nd premolar crown length ${\times}$ 3.910 lower 2nd molar root length ${\times}$ 2.280 - lower 1st molar apical width ${\times}$ 6.217 Age was estimated in boys and girls using the mathematic model ; the mean difference between chronological and estimated ages was $-2.1{\pm}6.8$ months for boys and $6.1{\pm}6.2$ months for girls. Therefore, it seems to be more accurate and easier than the earlier methods.

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Prevalence of Arthritis and Health Behavior Related Risk Factors of the Older Residents in Andong Rural Area (안동 농촌지역 중년 및 노인 주민의 관절염 유병율과 건강습관 관련 위험요인 분석)

  • Lee, Hye-Sang;Kwon, Chong-Suk
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.9
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    • pp.1187-1194
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    • 2009
  • This study was performed to estimate the prevalence and the risk factors of arthritis in Andong rural area in 2003. The subjects were 1,462 people (544 males, 818 females) aged 45 years and over. The arthritis group was composed of 322 people (72 males, 250 females), diagnosed by doctor or self-diagnosed by the symptoms. Prevalence of arthritis was higher in female (27.2%) compared to male (13.2%). Mean age of arthritis group was significantly higher than that of normal group (male 66.2 vs 62.8, female 62.6 vs 60.1, p<0.001). The anthropometric measurements, such as % body fat, body mass index (BMI), and waist circumference, and the biochemical measurements, such as plasma triglyceride and total cholesterol level, were significantly higher only in female (not in male) arthritis group than those in normal group. Health related lifestyle factors, such as smoking, alcohol drinking, and exercise, were not different between both groups. The risk factors for arthritis were analyzed using the multiple logistic regression method and expressed as odds ratio (OR). The results showed that female compared to male (OR=1.983), over 65 years compared to 45$\sim$64 years (male OR=2.769 and female OR=1.461), and obese female subjects (not for male) by % body fat ($\geq$32% OR=2.035) or BMI ($\geq$25 kg/$m^2$ OR=1.556) showed significantly higher risk factors for arthritis. Regarding nutrient intakes, higher intakes of fat (OR=1.443), calcium (OR=1.503), iron (OR=1.518) and vitamin A (OR=1.390) in female seemed to be risk factors. In contrast to female, higher intakes of vitamin A (OR=0.526) and riboflavin (OR=0.582) seemed to decrease the risk for arthritis in male. This study revealed that the prevalence of arthritis was significantly higher in female and aged individuals. Also, in order to decrease the prevalence and/or prevention of arthritis, female should prevent overfatness and decrease some nutrient intakes, while male should increase their intakes.