• Title/Summary/Keyword: t검정 통계 분석

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An Empirical Study on the Characteristics of Stock Returns in Chinese Stock Market -Focusing on the period of 1995 to 2007 - (중국 주식시장의 수익률 특성에 관한 실증연구 - 1995년부터 2007년 기간을 중심으로 -)

  • Kim, Kyung Won;Choi, Joon Hwan
    • International Area Studies Review
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    • v.13 no.3
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    • pp.287-308
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    • 2009
  • This article examines the distributional characteristics of the return of Chinese stock market indices. The majority of previous empirical researches have tended to focus upon the simple stock market index. However, this study focuses on the four indices which represent the characteristics of each stock market index. The empirical findings indicate that the returns of the four chinese indices are not normally distributed at conventional levels. The Ljimg-Box -statistics indicate the returns of the index of A shares are not serially autocorrelated. However, the returns of the index of B shares are serially autocorrelated. The empirical findings also indicate returns of the four chinese indices are not serially autocorrelated. The statistics of Regression Specification Error Test and ARCH indicate the returns of all four indices are not serially linear. The findings also indicate that E- GARCH model is the most fittest model for the returns of the four chinese indices and the forecast error can be reduced by using student t distribution rather normal distribution.

The Strategies for the Sustainable Management of Insurance Companies (보험회사의 지속가능경영 전략에 관한 연구)

  • Jung, Se-Chang;Seon, Hwan-Kyu
    • Communications for Statistical Applications and Methods
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    • v.18 no.1
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    • pp.119-130
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    • 2011
  • This paper measures and analyzes the performance of insurance companies in Korea in respect to sustainable development and suggest strategic implications based on the analysis. The correlation, regression, ANOVA, and t-test are employed. The results of this study are summarized as follows. First, it shows tat social index is important in the life insurance industry; however, the environmental index, is important in the non-life insurance industry. Second, the result gained by regressing the size and financial soundness on the performance of sustainable development demonstrates that the size variable is statistically significant. It suggests that size is a necessary condition for sustainable development. Finally, ANOVA shows that the small and medium sized companies have a significantly poor performance compared to the large companies concerning the social index and reputation index in the life insurance industry. The small and medium sized companies in the non-life insurance industry exhibit a significantly poor performance compared to the large companies in respect to all the indexes, except for the social index. Therefore, the small and medium sized companies make every endeavor in the poor indexes to improve performance.

Effects of an exercise program for fall prevention of the elderly in rural communities (농촌지역 노인을 위한 낙상예방운동의 효과)

  • Kang, Ki-Seon;Kim, Hyo-Sil
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.8
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    • pp.5186-5194
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    • 2014
  • Falls are one of the most serious problem that threatens the health of the elderly. This study was conducted twice a week for six weeks from May to June 2014 to evaluate the effectiveness of fall prevention exercises for rural seniors. This study analyzed the effects by comparing before and after exercise on the TUG, FRT, BBS, ADL, fear of falls, fall efficacy, and depression. The results of this study was as follows: Hypothesis1, "a TUG of post-test will improve more than the pre-test", was supported. Hypothesis3, "BBS of the post-test would improve more than the pre-test" was supported. In addition, the FRT, ADL, fear of fall, fall efficacy, and depression of post-test would improve more than the pre-test. Accordingly this study showed that fall prevention exercises are effective in improving the physical function (TUG, FRT, BBS, and ADL) and emotional function (fear of fall, fall efficacy, and depression) in rural seniors.

Statistical analyses in an occupational health study (산업보건연구에서의 통계학적 분석)

  • 백도명;최정근;손미아
    • The Korean Journal of Applied Statistics
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    • v.6 no.2
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    • pp.201-215
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    • 1993
  • The health status of workers in a foundry was analyzed in a study which consisted of evaluations of respiratory health together with environmental measurements. The results from environmental measurements showed values exceeding permissible exposure limits. A t-test was done with log transformed and untransformed data to examine the statistical significance for the noncompliance with exposure standards. For the analysis of categorical health outcomes, $\chi$-square test with 2 $\times$ 2 tables and logistic regression analysis were employed. For continuous variables, multiple linear regression was done against assessed risk factors. Pros and cons of different parameters in the compliance (or noncompliance) testing were presented. Respiratory function did not show any relation with occupational exposures, which may be due to the healthy worker effects. Strategies for controlling time dependent covariates were discussed in relation to the healthy worker effect. The scope of statistical analysis in occupational health studies is still limited in Korea without a suitable external comparison group such as credible vital statistics for the whole nation. Internal comparisons between different exposure status often result in unstable estimates of effect, and proportional morbidity study is discussed as an alternative potential research tool.

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The Comparison of the Environment Consciousness and the Disposal Behavior Between the Urban Children and the Rural Children (아동의 환경의식과 처분행동에 관한연구 -도시와 농촌간의 비교연구-)

  • 강이주
    • Journal of Families and Better Life
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    • v.13 no.2
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    • pp.35-44
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    • 1995
  • 본연구의 목적은 아동의 환경의식과 처분행동을 조사하여 환경문제에 대한 아동의 역할을 조명하고 조기환경교육의 기초자료를 제공하는데 있다 조사도구는 질문지를 이용하 였고 분석방법은 SAS통계프로그램을 이용하였다 환경의시과 처분행동의 차이는 ANOVA와 Tukey test를 지역간(도시, 농촌)의 차이는 t-test 와 $\chi$2 검정을 사용하였다 분석에 이용된 자료는 도시 311부 농촌 299부로 총 610부였다 본연구의 결과를 요약하면 다음과 같다 1) 도시와 농촌간의 환경의식은 통계적으로 유의한 차이가 없이 모두 높게 나타났다 2) 인구통 계변수에 따른 환경의식은 생활수준과어머니의 교육수준이 높을수록 높았으며 주거형태별로 는 아파트 거주자가 높게 나타났다 3) 도시와 농촌간의 처분행동은 유의적인 차이를 보였는 데 도시 지역이 높게 나타났다 4) 인구통계변수에 따른 처분행동은 환경의식과 마찬가지로 소득과 어머니의 교육수준이 높을수록 높았으며 아파트 거주자와 종교가 있느 아동이 높게 나타났다 이러한 결과는 환경을 고려하는 행동양식의선행변수가 교육임을 재확인해주었다

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Improvement of School Sheriff System as a Security Guard Field (학교보안관 제도의 개선 방안)

  • Kang, Min-Wan;Kim, Eun-Jung
    • The Journal of the Korea Contents Association
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    • v.11 no.12
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    • pp.774-784
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    • 2011
  • The purpose of this study, which was conducted as a part of investigations for vitalizing the School Sheriff system proposed as a means to prevent school violence and promote school safety, was to survey recognition of elementary school parents toward the School Sheriff system and present an improvement scheme for the system. For the study, we selected as the research object a set of parents whose children attended schools with School Sheriffs and then sampled 200 parents out of them with cluster random sampling, before analyzing 189 finally. Validity of the questionnaire is verified by expert council and factorial analysis, and reliability by reliability analysis. Statistical means including chi-square test, t-test and F-test are used. The result of the study as follows : First, necessity of the School Sheriff system varies by individual characteristics. Second, recognition toward the system itself varies by individual characteristics. Third, recognition toward the role that should be played by School Sheriffs varies by individual characteristics. Fourth, there is a difference in perceiving the role and activity of School Sheriffs, Fifth, whether the system helped improving school safety varies by individual characteristics. Sixth, the satisfaction from the School Sheriffs.

The Relationship between Perception and Satisfaction for National Health Insurance in Korea (국민건강보험 인식수준과 만족도의 관계)

  • Ahn, Young-Chang
    • The Journal of the Korea Contents Association
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    • v.14 no.8
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    • pp.277-286
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    • 2014
  • The purpose of this study was to identify the relationship between the health insurance perception level and health insurance satisfaction for national health insurance subscriber. The collected data were analyzed by $X^2$-test, t-test, ANOVA using the SPSS/WIN (ver.14.0). Research results can be summarized as follows. The relationship between the health insurance perception level and health insurance satisfaction was relatively high. The study showed significantly high levels in the score of health insurance satisfactions according to perception of security level, health insurance premium, positive thinking, and fair in premium charge. Also health insurance satisfaction scores were significantly low levels according to perception of raise health insurance premium and burden on households. This study investigated the relationship between the detail perception and satisfaction for national health insurance. Therefore, we are setting the overall direction of national health insurance perception, and look forward to utilizing the basis data as help to improve the system of health insurance for people.

Characteristics of TSP Concentrations Measured at Gosan: Statistical Analysis (고산에서 측정한 TSP 농도 특성: 통계적 해석)

  • 박민하;김용표;강창희;김원형
    • Journal of Korean Society for Atmospheric Environment
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    • v.19 no.1
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    • pp.93-100
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    • 2003
  • In this technical information, the long-term measurement data at Gosan between 1992 and 2001 are analyzed with various statistical methods. First. it was confirmed that the basic assumption of t-test is important to classify data correctly. Second, it was founded that the difference of the number of data per month can affect the averaged concentration. Third, by using a non-parametric statistical method long term trend of aerosol composition free from seasonal effects is obtained.

Relationships among Public Service Motivation, Hospital Organizational Culture Types, Job-esteem, and Turnover Intentions of Public Hospital Nurses (일개 지역 공공병원 간호사의 공공봉사동기, 병원조직문화유형, 직업존중감 및 이직의도간의 관계)

  • Choi, Seungmi;Park, Sunah
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.5
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    • pp.619-629
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    • 2022
  • This study aims to investigate the relationship among public service motivation, hospital organizational culture type, job-esteem, and turnover intention of public hospital nurses. A cross-sectional study was conducted on 124 nurses at four public hospitals in the Gyeonggi Province (Icheon, Anseong, Suwon, Paju). Data were analyzed using descriptive statistics, t-tests, ANOVA, and Pearson correlation coefficient. Mann-Whitney U test and the Kruskal-Wallis test were used with the Bonferroni test for post hoc comparison when the data were not normally distributed. The turnover intention of the subjects was public service motivation (r=-.30, p<.001), affiliative culture (r=-.28, p=.002), innovative culture (r=-.34, p< .001) and task culture (r=-.30, p=.001) were negatively correlated. Study findings suggest that public service motivation must be increased to reduce the turnover intention of nurses in public hospitals.

The Comparative Analysis Study and Usability Assessment of Fat Suppressed 3D FSPGR T1 Technique and Fat Suppressed Isotropic 3D FSE T1 Technique when Examining MRI of Patient with Triangular Fibrocartilage Complex (TFCC) Tear (삼각 섬유성 연골(TFCC) 손상 환자의 자기공명영상 검사 시 Fat Suppressed 3D FSPGR T1 강조 기법에 대한 Fat Suppressed Isotropic 3D FSE T1 강조 기법의 비교 분석 및 유용성에 관한 평가)

  • Kang, Sung-Jin;Cho, Yong-Keun;Lee, Sung-Soo
    • Journal of the Korean Magnetics Society
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    • v.26 no.3
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    • pp.105-114
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    • 2016
  • In this study, For assessment of triangular fibrocartilage complex (TFCC) injury, we acquired images by fat suppressed 3D fast spoiled gradient recalled T1 and fat suppressed Isotropic 3D fast spin echo T1 techniques. For quantitative evaluation, measured signal to noise ratio and contrast to noise ratio and verified statistical significance between two imaging techniques by Mann-Whitney U verification. And for qualitative evaluation, marked 4-grade scoring (0: non diagnostic, 1: poor, 2: adequate, 3: good) on shape of TFCC, artifacts by partial volumes, description of the lesions by two radiologist, verified coincidence between 2 observer using Kappa-value verification. We used 3.0 Tesla MR equipment and 8-channel RF coil for imaging acquisition. As quantitative evaluation results, signal to noise ratio and contrast to noise ratio value of Isotropic 3D fast spin echo T1 technique is higher in every image sections, also between two imaging techniques by Mann-Whitney U verification was statistically significant (p < 0.05). As qualitative results, observer 1, 2 marked a higher grade on Isotropic 3D FSE T1 technique, coincidence verification of evaluation results between two observers by Kappa-value verification was statistically significant (p < 0.05). As a result, during MRI examination on TFCC injury, fat suppressed Isotropic 3D fast spin echo T1 technique is considered offering more useful information about abnormal lesion of TFCC.