• Title/Summary/Keyword: T-Test

Search Result 23,673, Processing Time 0.049 seconds

The Effects of Education Program on Knowledge and Intention of Breast Cancer Screening in Taiwan

  • Wang, Hsiu-Ho;Chung, Yu-Chu;Sun, Jia-Ling
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.13 no.11
    • /
    • pp.5545-5549
    • /
    • 2012
  • Aims: The purpose of this study was to investigate the effects of a breast cancer screening educational program on women's knowledge and intention to seek breast cancer screening in Taiwan. Materials and Method: This study describes the knowledge and intention of breast cancer screening changes during the period pre and post group education. A pre-test and post-test were used in both the experimental and the control groups. A convenience sampling was used. Two structured questionnaires were used. Results: The mean knowledge of breast cancer screening scores (pre-test and post-test) of the experimental group participants were 12.6 and 14.0. Then the mean knowledge of breast cancer screening scores (pre-test and post-test) of the control group participants were 11.8 and 12.1. The mean intention of breast cancer screening scores (pre-test and post-test) of the experimental group participants were 11.4 and 13.5. And the mean intention of breast cancer screening scores (pre-test and post-test) of the control group participants were 11.6 and 12.4. An independent-t test was applied to examine the differences among the two groups, revealing that the average post-test knowledge score differ significantly between the two groups (t =4.18, p<.00); and the post-test intention also demonstrate a marked statistical difference (t = 2.07, p<.05). A paired-t test was applied to examine the differences of each group, revealing that the total average scores of the experimental group participants on the knowledge of breast cancer screening scale clearly differ statistically (t =-5.54, p<.00); and the pre-test and post-test intention testing also demonstrate a marked statistical difference (t =-7.70, p<.00). Conclusions: These findings are helpful in understanding the knowledge and intention of breast cancer screening changes during the period pre and post group education. It is expected that these results can offer a reference for clinical breast cancer prevention.

A Study on Teaching Method of Two-Sample Test for Population Mean Difference (두 모집단 모평균 비교의 지도에 관한 연구)

  • Kim Yong-Tae;Lee Jang-Taek
    • The Mathematical Education
    • /
    • v.45 no.2 s.113
    • /
    • pp.145-154
    • /
    • 2006
  • The main purpose of this study is to investigate the effect of departures from normality and equal variance on the two-sample test when the variances are unknown. We have found that type I error brought about a little bit change which is ignorable in relation to kurtosis. But the change of type I error was mainly based on the skewness of the parent population. In introductory statistics classes where data analysis includes techniques for detecting skewness of two populations, we recommend the two-sample t-test when maximal skewness of two populations is smalter than the value 4 when the variances seem equal. Furthermore, our simulations reveal that the two-sample t-test appears somewhat more robust than that of z-test if the assumption of equal variance is satisfied. In the case of unequal variance, the two-sample t-test appears somewhat more robust provided the t-statistic using Satterthwaite's approximate degrees of freedom.

  • PDF

A Study on the Test of Mean Residual Life with Random Censored Sample (임의 절단된 자료의 평균잔여수명 검정에 관한 연구)

  • 김재주;이경원;나명환
    • Journal of Korean Society for Quality Management
    • /
    • v.25 no.3
    • /
    • pp.11-21
    • /
    • 1997
  • The mean residual life(MRL) function gives the expected remaining life of a item at age t. In particular F is said to be an increasing intially then decreasing MRL(IDMRL) distribution if there exists a turing point $t^*\ge0$ such that m(s)$\le$ m(t) for 0$$\le s$\le$ t $t^*$, m(s)$\ge$ m(t) for $t^*\le$ s$\le$ t. If the preceding inequality is reversed, F is said to be a decreasing initially then increasing MRL(DIMRL) distribution. Hawkins, et al.(1992) proposed test of H0 : F is exponential versus$H_1$: F is IDMRL, and $H_0$ versus $H_1$' : F is DIMRL when turning point is unknown. Their test is based on a complete random sample $X_1$, …, $X_n$ from F. In this paper, we generalized Hawkins-Kochar-Loader test to random censored data.

  • PDF

Noise Test and Evaluation of a 750 kW Wind Turbine Generator (750 kW 풍력발전기의 소음 실증)

  • Kim, Seock-Hyun;Kim, Tae-Hyung
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.16 no.2 s.107
    • /
    • pp.124-131
    • /
    • 2006
  • This study introduces an environmental noise evaluation procedure for wind turbines(W/T) and the evaluation result of a 750 kW wind turbine(W/T) system. Test and evaluation are performed according to the international standard IEC 61400-11 on J48 W/T which is under operation in Daekwanryung W/T test site. With the meteorological data and W/T operational data, noise data are monitored and analysed. An integrated monitoring system is constructed in the test site and is utilized for the evaluation. From the measured noise data, acoustic power level, directivity and tonality of the W/T are estimated under the wind speeds required fly the International standard. The purpose of the study is to establish an W/T noise evaluating system satisfying the international standard and to obtain noise data for home made 750 kW W/T.

Effects of Emotion Freedom Techniques on Academic Stress in Korean Medical Students: A Single-Group Pre-Post Study

  • Lee, Seung Hwan;Han, Sang Yun;Lee, Soo Jin;Chae, Han;Lim, Jung Hwa
    • Journal of Oriental Neuropsychiatry
    • /
    • v.33 no.1
    • /
    • pp.33-48
    • /
    • 2022
  • Objectives: Academic stress poses a significant risk for the mental health of medical students, and a feasible group intervention program for managing academic stress is required. The purpose of this study was to examine the clinical effectiveness of emotional freedom techniques (EFT) on the mental health of Korean medical students. Methods: The class of first-year medical school students (n=36) participated in an after-school EFT group intervention program comprising six sessions (15 minutes/session, three weeks) to analyze its clinical effectiveness as a single-group test-retest clinical study. The changes in the Perceived Stress Scale (PSS), Test Anxiety Inventory (TAI), Positive and Negative Affect Schedule (PANAS), and State-Trait Anxiety Inventory (STAI) scores were examined using a paired t-test and Cohen's D at post-EFT and two-week follow-up. Results: There were significant curtailments at post-EFT and follow-up measures in TAI-Total (t=2.704 and t=3.289), TAI-Worry (t=2.297 and t=2.454), TAI-Emotionality (t=2.763 and t=3.654), PSS-Negative Perspective (t=2.659 and t=3.877), and PANAS-Negative Affect (t=2.885 and t=3.259) subscales, however not in PSS-Positive Perspective (t=-1.279 and t=-1.101) and PANAS-Positive Affect (t=0.194 and t=-0.122) subscales. The trait anxiety (t=2.227) was significantly mitigated in the post-EFT measure and the state anxiety (t=2.30) in the follow-up measure. Conclusions: The EFT group intervention alleviated test stress, negative affect, and anxiety in the Korean medical students. This study contributes to an understanding of academic stress and EFT intervention in the competitive environment of medical education.

Convergence Effect of Horticulture Activity Program on Self-esteem and School Life Adaptation of Multicultural Adolescent. (원예활동프로그램이 다문화청소년의 자아존중감과 학교생활적응에 미치는 융합효과)

  • Ha, Yoon-Joo;Kim, Eun-A
    • Journal of Digital Convergence
    • /
    • v.17 no.6
    • /
    • pp.409-416
    • /
    • 2019
  • The purpose of this study was to investigate the effect of horticulture activity program on self-esteem and school life adaptation of multicultural adolescent. A non-equivalent control group pre-post test design with experimental group (n=39) and control group (n=36) was used. The program was conducted from Jan. 2 to Feb. 28, 2017, and the questionnaire was conducted before and after the program. Collected data was analyzed by SPSS(Ver, 24.0), conducting ${\chi}^2-test$, Fisher's exact test, t-test, paired t-test. There were statistically significant increase in self-esteem(t=2.41, p=.021) and school life adaptation(t=3.85, p=.000) by difference between a pretest and a posttest in the experimental group compared to that in the control group. Therefore, the horticulture activity program for multicultural adolescent have a significant effect for better performance of self-esteem and school life adaptation. Also, It was confirmed that the program used for improving adaptability of multicultural adolescent.

Statistical methods for testing tumor heterogeneity (종양 이질성을 검정을 위한 통계적 방법론 연구)

  • Lee, Dong Neuck;Lim, Changwon
    • The Korean Journal of Applied Statistics
    • /
    • v.32 no.3
    • /
    • pp.331-348
    • /
    • 2019
  • Understanding the tumor heterogeneity due to differences in the growth pattern of metastatic tumors and rate of change is important for understanding the sensitivity of tumor cells to drugs and finding appropriate therapies. It is often possible to test for differences in population means using t-test or ANOVA when the group of N samples is distinct. However, these statistical methods can not be used unless the groups are distinguished as the data covered in this paper. Statistical methods have been studied to test heterogeneity between samples. The minimum combination t-test method is one of them. In this paper, we propose a maximum combinatorial t-test method that takes into account combinations that bisect data at different ratios. Also we propose a method based on the idea that examining the heterogeneity of a sample is equivalent to testing whether the number of optimal clusters is one in the cluster analysis. We verified that the proposed methods, maximum combination t-test method and gap statistic, have better type-I error and power than the previously proposed method based on simulation study and obtained the results through real data analysis.

A Study on the Evaluation of the Pipe Fracture Characteristic (I) (실배관 파괴특성 평가에 관한 연구 (I))

  • Park, Jae-Sil;Seok, Chang-Sung
    • Proceedings of the KSME Conference
    • /
    • 2001.06a
    • /
    • pp.345-350
    • /
    • 2001
  • In order to perform elastic-plastic fracture mechanical analyses, fracture resistance curves for concerned materials are required. 1T-CT specimen was used to obtain fracture resistance curves. But the fracture resistance curve by the 1T-CT specimen was very conservative to evaluate the integrity of the structure. And fracture resistance curve was affected by the specimen geometry and crack plane orientation. The objective of this paper is to be certain the conservativeness of the fracture resistance curve by the 1T-CT specimen and to provide the additional safety margin. For these, the fracture tests using the real pipe specimen and standard 1T-CT specimen test were performed. 4-point bending jig was manufactured for pipe test and direct current potential drop method was used to measure the crack extension and length for pipe test. From the pipe and the 1T-CT specimen test results, it was observed that the J-integral of the 1T-CT specimen test at the crack initiation point was very small compare to that of the pipe specimen test.

  • PDF

Studies on the Influence of Various Factors on 2, 3, 5-Triphenyl Tetrazolium Chloride Reduction Test(T.T.C. Test) (2, 3, 5-Triphenyl Tetrazolium Chloride 환원시험(還元試驗)(T. T. C. Test)에 미치는 요인(要因)에 관한 연구(硏究))

  • Kim, Kyo-Joon;Kim, Sang Keun
    • Korean Journal of Agricultural Science
    • /
    • v.5 no.2
    • /
    • pp.80-86
    • /
    • 1978
  • This study was carried out in order to know the effect of T. T. C. reaction on antibiotics, cleanser, disinfectants, pH, acidity and station of culture a bacterial Streptococcus thermophilus was used to 2.3.5-triphenyl tetrazolium chloride reduction test for the detection of residual antibiotics in milk were tested. The results obtained were summarized as follows. 1. The T. T. C. reaction was most sensitive in the group of penicillin as 0.02~0.05 IU and also it was less sensitive in Streptomycin and various broad antibiotics except Vibramycin, Synthomycin and Teramycin but it was least sensitive in Streptomycin group. 2. For ther T. T. C. reaction test on cleanser, the positive reaction was appeared above 0.7% of Hi-Ti and 0.1% of NaOH solution respectively. 3. For the T. T. C. test reaction on disinfectants, the positive reaction was occured on 200~500 ppm solution of sodium-hypochlorite and chloride-lime, 0.15~0.35% solution of phenol, cresol and Iode-K. 4. The optimum temperature was $35{\sim}37^{\circ}C$ and proper culturing time was 12 to 18 hours for propagation culturing. 5. The suspect positive reaction was tested above pH 5.0 and the positive reaction was appeared above 0.21% of acidity.

  • PDF

A study on the development of quality control algorithm for internet of things (IoT) urban weather observed data based on machine learning (머신러닝기반의 사물인터넷 도시기상 관측자료 품질검사 알고리즘 개발에 관한 연구)

  • Lee, Seung Woon;Jung, Seung Kwon
    • Journal of Korea Water Resources Association
    • /
    • v.54 no.spc1
    • /
    • pp.1071-1081
    • /
    • 2021
  • In addition to the current quality control procedures for the weather observation performed by the Korea Meteorological Administration (KMA), this study proposes quality inspection standards for Internet of Things (IoT) urban weather observed data based on machine learning that can be used in smart cities of the future. To this end, in order to confirm whether the standards currently set based on ASOS (Automated Synoptic Observing System) and AWS (Automatic Weather System) are suitable for urban weather, usability was verified based on SKT AWS data installed in Seoul, and a machine learning-based quality control algorithm was finally proposed in consideration of the IoT's own data's features. As for the quality control algorithm, missing value test, value pattern test, sufficient data test, statistical range abnormality test, time value abnormality test, spatial value abnormality test were performed first. After that, physical limit test, stage test, climate range test, and internal consistency test, which are QC for suggested by the KMA, were performed. To verify the proposed algorithm, it was applied to the actual IoT urban weather observed data to the weather station located in Songdo, Incheon. Through this, it is possible to identify defects that IoT devices can have that could not be identified by the existing KMA's QC and a quality control algorithm for IoT weather observation devices to be installed in smart cities of future is proposed.