• Title/Summary/Keyword: Chi-Square Goodness-of-Fit Test

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Development of Structural Equation Model for Causal Relationships Among the Risk Factors of Arteriosclerosis (동맥경화증 위험요인들간의 인과관계에 대한 구조모형 구축)

  • 오현수;서화숙
    • Journal of Korean Academy of Nursing
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    • v.29 no.6
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    • pp.1192-1207
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    • 1999
  • The purpose of this study was to clarify the dynamic relationships among risk factors of arteriosclerosis and to develop and examine a model which could explain this relationship clearly. Data were collected from medical records of 400 male clients who visited a university hospital located in Inchon for physical examinations, from May 1996 to December 1996. Data were analyzed using the LISREL (Linear Structural Relationship) 8 program. To test the fitness of the hypothesized model, chi-square, RMSR (root mean square residual), GFI (goodness of fit index), CN (critical number) and Q-plot were used. Most of the fitness measurements, except the chi-square showed that the hypothesized model complimented the real data. According to the results, there were trends that obesity and hyperlipidemia were prevalent in heavier smokers, higher alcohol intakers, and groups who excercised less. Also, hypertension was more prevalent in older age, higher alcohol intaker, and higher serum lipid level groups. In contrast to the hypothesis, alcohol intake did not significantly affect serum lipid levels. This might be due to the serum lipid measurements (total cholesterol and trigryceride) used in this study to estimate hyperlipidemia. The direct effect of smoking on hypertension was not significant. However, the total effect of smoking on the hypertension was significant since indirect effects of smoking on hypertension, such as obesity and hyperlipidemia, were significant. The total effect of obesity on hypertension was significant since the indirect effect of obesity on hypertension via hyperlipidemia was significant, although the direct effect of smoking on hypertension was not significant. The degree of explaining hyperlipidemia with smoking, exercise, and obesity was high (60%), however, the degree of explaining obesity with age, smoking, alcohol intake, and exercise was very low (7%). On the basis of these results, high risk factors of arteriosclerosis such as hypertension, hyperlipidemia, or obesity are either directly or indirectly correlated each other. Therefore, it is difficult to predict outcomes for increasing or decreasing the risk factors by simply modulating a factor. Smoking, alcohol, and exercise both directly and indirectly affected major risk factors of arteriosclerosis. Therefore, correcting these variables is required to decrease risk factors. Finally, the relationship among other risk factors which have been known to be related with arteriosclerosis (diet, stress or hereditary) should be clarified in further studies.

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Similarity between the dispersion parameter in zero-altered model and the two goodness-of-fit statistics (영 변환 모형 산포형태모수와 두 적합도 검정통계량 사이의 유사성 비교)

  • Yun, Yujeong;Kim, Honggie
    • Journal of the Korean Data and Information Science Society
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    • v.28 no.3
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    • pp.493-504
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    • 2017
  • We often observe count data that exhibit over-dispersion, originating from too many zeros, and under-dispersion, originating from too few zeros. To handle this types of problems, the zero-altered distribution model is designed by Ghosh and Kim in 2007. Their model can control both over-dispersion and under-dispersion with a single parameter, which had been impossible ever. The dispersion type depends on the sign of the parameter ${\delta}$ in zero-altered distribution. In this study, we demonstrate the role of the dispersion type parameter ${\delta}$ through the data of the number of births in Korea. Employing both the chi-square statistic and the Kolmogorov statistic for goodness-of-fit, we also explained any difference between the theoretical distribution and the observed one that exhibits either over-dispersion or under-dispersion. Finally this study shows whether the test statistics for goodness-of-fit show any similarity with the role of the dispersion type parameter ${\delta}$ or not.

Testing Independence in Contingency Tables with Clustered Data (집락자료의 분할표에서 독립성검정)

  • 정광모;이현영
    • The Korean Journal of Applied Statistics
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    • v.17 no.2
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    • pp.337-346
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    • 2004
  • The Pearson chi-square goodness-of-fit test and the likelihood ratio tests are usually used for testing independence in two-way contingency tables under random sampling. But both of these tests may provide false results for the contingency table with clustered observations. In this case we consider the generalized linear mixed model which includes random effects of clustering in addition to the fixed effects of covariates. Both the heterogeneity between clusters and the dependency within a cluster can be explained via generalized linear mixed model. In this paper we introduce several types of generalized linear mixed model for testing independence in contingency tables with clustered observations. We also discuss the fitting of these models through a real dataset.

Effects of Bullying Experience on Psychological Well-Being Mediated by Conflict Management Styles and Psychological Empowerment among Nursing Students in Clinical Placement: A Structural Equation Modeling Approach

  • Ren, Liping;Kim, Hyunli
    • Journal of Korean Academy of Nursing
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    • v.47 no.5
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    • pp.700-711
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    • 2017
  • Purpose: This study aimed to test a proposed structural equation model in which bullying experience, conflict management styles and psychological empowerment predict psychological well-being among Chinese nursing students in clinical placement. Methods: Three hundred and sixty-six nursing students recruited from five hospitals in J city and Y city were assessed with self-report questionnaires on bullying experience, conflict management styles, psychological empowerment and psychological well-being including depression, self-esteem, and academic major satisfaction. Data were analyzed using SPSS version 20.0 and AMOS version 22.0. Results: The evaluation parameters included the comparative fit index at .90, the goodness of fit index at .93, the root mean square error of approximation at .07, and ${\chi}^2/df$ ratio at 2.66, indicating that the proposed structural equation model provided a good fit to the data. Experience of being bullied during clinical placement, conflict management styles and psychological empowerment explained 93.0% of the variance and had significant effects on psychological well-being, with conflict management styles and psychological empowerment mediating the association between bullying and psychological well-being. Conclusion: The findings indicated that mediation by conflict management styles and psychological empowerment alleviated the negative influence of bullying on psychological well-being. To limit bullying and its negative effects, development of effective guidelines to deal with bullying will be a critical tool for both Chinese nursing students and their instructors. Further research should incorporate conflict management styles and psychological empowerment into the specific intervention strategies for handling bullying behaviors among nursing students and staff nurses and promoting nursing students' psychological well-being.

The Effects of Evaluation Attributes of Cultural Tourism Festivals on Satisfaction and Behavioral Intention (문화관광축제 방문객의 평가속성 만족과 행동의도에 관한 연구 - 2006 광주김치대축제를 중심으로 -)

  • Kim, Jung-Hoon
    • Journal of Global Scholars of Marketing Science
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    • v.17 no.2
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    • pp.55-73
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    • 2007
  • Festivals are an indispensable feature of cultural tourism(Formica & Uysal, 1998). Cultural tourism festivals are increasingly being used as instruments promoting tourism and boosting the regional economy. So much research related to festivals is undertaken from a variety of perspectives. Plans to revisit a particular festival have been viewed as an important research topic both in academia and the tourism industry. Therefore festivals have frequently been leveled as cultural events. Cultural tourism festivals have become a crucial component in constituting the attractiveness of tourism destinations(Prentice, 2001). As a result, a considerable number of tourist studies have been carried out in diverse cultural tourism festivals(Backman et al., 1995; Crompton & Mckay, 1997; Park, 1998; Clawson & Knetch, 1996). Much of previous literature empirically shows the close linkage between tourist satisfaction and behavioral intention in festivals. The main objective of this study is to investigate the effects of evaluation attributes of cultural tourism festivals on satisfaction and behavioral intention. accomplish the research objective, to find out evaluation items of cultural tourism festivals through the literature study an empirical study. Using a varimax rotation with Kaiser normalization, the research obtained four factors in the 18 evaluation attributes of cultural tourism festivals. Some empirical studies have examined the relationship between behavioral intention and actual behavior. To understand between tourist satisfaction and behavioral intention, this study suggests five hypotheses and hypothesized model. In this study, the analysis is based on primary data collected from visitors who participated in '2006 Gwangju Kimchi Festival'. In total, 700 self-administered questionnaires were distributed and 561 usable questionnaires were obtained. Respondents were presented with the 18 satisfactions item on a scale from 1(strongly disagree) to 7(strongly agree). Dimensionality and stability of the scale were evaluated by a factor analysis with varimax rotation. Four factors emerged with eigenvalues greater than 1, which explained 66.40% of the total variance and Cronbach' alpha raging from 0.876 to 0.774. And four factors named: advertisement and guides, programs, food and souvenirs, and convenient facilities. To test and estimate the hypothesized model, a two-step approach with an initial measurement model and a subsequent structural model for Structural Equation Modeling was used. The AMOS 4.0 analysis package was used to conduct the analysis. In estimating the model, the maximum likelihood procedure was used.In this study Chi-square test is used, which is the most common model goodness-of-fit test. In addition, considering the literature about the Structural Equation Modeling, this study used, besides Chi-square test, more model fit indexes to determine the tangibility of the suggested model: goodness-of-fit index(GFI) and root mean square error of approximation(RMSEA) as absolute fit indexes; normed-fit index(NFI) and non-normed-fit index(NNFI) as incremental fit indexes. The results of T-test and ANOVAs revealed significant differences(0.05 level), therefore H1(Tourist Satisfaction level should be different from Demographic traits) are supported. According to the multiple Regressions analysis and AMOS, H2(Tourist Satisfaction positively influences on revisit intention), H3(Tourist Satisfaction positively influences on word of mouth), H4(Evaluation Attributes of cultural tourism festivals influences on Tourist Satisfaction), and H5(Tourist Satisfaction positively influences on Behavioral Intention) are also supported. As the conclusion of this study are as following: First, there were differences in satisfaction levels in accordance with the demographic information of visitors. Not all visitors had the same degree of satisfaction with their cultural tourism festival experience. Therefore it is necessary to understand the satisfaction of tourists if the experiences that are provided are to meet their expectations. So, in making festival plans, the organizer should consider the demographic variables in explaining and segmenting visitors to cultural tourism festival. Second, satisfaction with attributes of evaluation cultural tourism festivals had a significant direct impact on visitors' intention to revisit such festivals and the word of mouth publicity they shared. The results indicated that visitor satisfaction is a significant antecedent of their intention to revisit such festivals. Festival organizers should strive to forge long-term relationships with the visitors. In addition, it is also necessary to understand how the intention to revisit a festival changes over time and identify the critical satisfaction factors. Third, it is confirmed that behavioral intention was enhanced by satisfaction. The strong link between satisfaction and behavioral intentions of visitors areensured by high quality advertisement and guides, programs, food and souvenirs, and convenient facilities. Thus, examining revisit intention from a time viewpoint may be of a great significance for both practical and theoretical reasons. Additionally, festival organizers should give special attention to visitor satisfaction, as satisfied visitors are more likely to return sooner. The findings of this research have several practical implications for the festivals managers. The promotion of cultural festivals should be based on the understanding of tourist satisfaction for the long- term success of tourism. And this study can help managers carry out this task in a more informed and strategic manner by examining the effects of demographic traits on the level of tourist satisfaction and the behavioral intention. In other words, differentiated marketing strategies should be stressed and executed by relevant parties. The limitations of this study are as follows; the results of this study cannot be generalized to other cultural tourism festivals because we have not explored the many different kinds of festivals. A future study should be a comparative analysis of other festivals of different visitor segments. Also, further efforts should be directed toward developing more comprehensive temporal models that can explain behavioral intentions of tourists.

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New approach to calculate Weibull parameters and comparison of wind potential of five cities of Pakistan

  • Ahmed Ali Rajput;Muhammad Daniyal;Muhammad Mustaqeem Zahid;Hasan Nafees;Misha Shafi;Zaheer Uddin
    • Advances in Energy Research
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    • v.8 no.2
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    • pp.95-110
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    • 2022
  • Wind energy can be utilized for the generation of electricity, due to significant wind potential at different parts of the world, some countries have already been generating of electricity through wind. Pakistan is still well behind and has not yet made any appreciable effort for the same. The objective of this work was to add some new strategies to calculate Weibull parameters and assess wind energy potential. A new approach calculates Weibull parameters; we also developed an alternate formula to calculate shape parameters instead of the gamma function. We obtained k (shape parameter) and c (scale parameter) for two-parameter Weibull distribution using five statistical methods for five different cities in Pakistan. Maximum likelihood method, Modified Maximum likelihood Method, Method of Moment, Energy Pattern Method, Empirical Method, and have been to calculate and differentiate the values of (shape parameter) k and (scale parameter) c. The performance of these five methods is estimated using the Goodness-of-Fit Test, including root mean square error, mean absolute bias error, mean absolute percentage error, and chi-square error. The daily 10-minute average values of wind speed data (obtained from energydata.info) of different cities of Pakistan for the year 2016 are used to estimate the Weibull parameters. The study finds that Hyderabad city has the largest wind potential than Karachi, Quetta, Lahore, and Peshawar. Hyderabad and Karachi are two possible sites where wind turbines can produce reasonable electricity.

An Estimation of Probable Precipitation and an Analysis of Its Return Period and Distributions in Busan (부산지역 확률강수량 결정에 따른 재현기간 및 분포도 분석)

  • Lim, Yun-Kyu;Moon, Yun-Seob;Kim, Jin-Seog;Song, Sang-Keun;Hwang, Yong-Sik
    • Journal of the Korean earth science society
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    • v.33 no.1
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    • pp.39-48
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    • 2012
  • In this study, a statistical estimation of probable precipitation and an analysis of its return period in Busan were performed using long-term precipitation data (1973-2007) collected from the Busan Regional Meteorological Administration. These analyses were based on the method of probability weighted moments for parameter estimation, the goodness-of-fit test of chi-square ($x^2$) and the probability plot correlation coefficient (PPCC), and the generalized logistics (GLO) for optimum probability distribution. Moreover, the spatial distributions with the determination of probable precipitation were also investigated using precipitation data observed at 15 Automatic Weather Stations (AWS) in the target area. The return periods for the probable precipitation of 245.2 and 280.6 mm/6 hr with GLO distributions in Busan were estimated to be about 100 and 200 years, respectively. In addition, the high probable precipitation for 1-, 3-, 6-, and 12-hour durations was mostly distributed around Dongrae-gu site, all coastal sites in Busan, Busanjin and Yangsan sites, and the southeastern coastal and Ungsang sites, respectively.

Can parents prevent tooth loss related to dental avulsion? An assessment of knowledge related to permanent teeth

  • Gowri Sivaramakrishnan;Deena Abawi;Fatima Mohammad Shoaib;Fatema Bucheery;Ahmed Ali Salman;Majeed Jasim Kadhem;Fatema AlSulaiti;Muneera Alsobaiei ;Leena AlSalihi
    • Journal of Trauma and Injury
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    • v.36 no.1
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    • pp.15-21
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    • 2023
  • Purpose: Dental avulsion injuries have a poor prognosis that largely depends on the immediate steps taken to manage the avulsed tooth. A lack of knowledge about the initial management can lead to tooth loss, with further adverse implications for esthetics, phonetics, and overall growth and function. Hence, the present study aimed to assess parents' knowledge regarding dental avulsion and the variables associated with their knowledge of avulsion injuries. Methods: A series of closed-ended questions on parents' knowledge regarding avulsion, such as immediate management, storage media, handling, and urgency of visiting the dentist, was asked. Univariate associations between the outcomes were assessed using the Pearson chi-square test. The chisquare goodness-of-fit test was used to check whether the sample data were representative of the population. Results: In total, 211 mothers and 149 fathers were included, of whom 46.7% had experienced dental trauma during their own childhood. Sixty-one percent of mothers believed that they knew everything necessary about tooth avulsion and its management. A significant number of participants who thought that they had a good level of knowledge about avulsion chose water, tissue, or paper wrap to transport the tooth, and preferred tap water, alcohol, or antiseptic to clean the avulsed tooth. Conclusions: Both mothers and fathers had poor knowledge about tooth avulsion, indicating that there is an immediate need for educational programs focusing on this issue. Since a substantial proportion of participants believed incorrect information, it is vital to disseminate accurate information.

The Extraction of Quality Evaluation Elements for Medical Serious Game (의료용 기능성 게임의 품질평가 요소 추출)

  • Yoon, Seon-Jeong;Ryu, Mi-Young
    • Journal of the Korea Society of Computer and Information
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    • v.18 no.3
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    • pp.19-26
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    • 2013
  • As the Medical Serious Games are recently proven effective, the quality evaluation of the game has become an important issue. In quality evaluation, objective criteria and evaluation elements are important. Quality evaluation of the serious game is divided into two areas : the technical (from the point of view of Program) and the non-technical (from the point of view of Content). In this study, we developed the quality evaluation element of the non-technical area to the psychotherapy and the health & rehab game according to developing process of quality evaluation model. We extracted five evaluation elements from the two kinds of medical games, and interviewed with medical experts in order to ensure the validity of them. The goodness of fit tests for the elements mentioned above were verified by conducting. Chi-square test results for the two groups did not differ significantly. In conclusion, we expect to take advantage of the results of this study to design and develop serious games for medical treatment.

A change of the public's emotion depending on Temperature & Humidity index (온습도에 따른 대중의 감성(감정+감각) 활동 변화)

  • Yang, Junggi;Kim, Geunyoung;Lee, Youngho;Kang, Un-Gu
    • Journal of Digital Convergence
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    • v.12 no.10
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    • pp.243-252
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    • 2014
  • Many researches about the effect on politics, economics and Sociocultural phenomenon using the social media are in progress. Authors utilized NAVER Trend most famous web browsing service in korea, NAVER Blog social media, NAVER Cafe service and Open Data(API) and also used temperature, humidity index data of Korea Meteorological Administration. This study analyzed a change of the public's emotion in korea using Cluster analysis of vocabulary of taste among its of feelings and senses. K-means clustering was followed by decision of the number of groups which was used Chi-square goodness of fit test and ward analysis. Eight groups was made and it represented sensitive vocabulary. By Discriminant analysis, eight groups decided by Cluster analysis has 98.9% accuracy. The change of the public's emotion has capability to predict people's activity so they can share sensibility and a bond of sympathy developed between them.