• Title/Summary/Keyword: test for hypothesis

Search Result 1,600, Processing Time 0.033 seconds

Optimal Weights of Linear Combinations of the Independent Poisson Signals for Discrimination

  • Kim, Joo-Hwan
    • Journal of the Korean Data and Information Science Society
    • /
    • v.13 no.2
    • /
    • pp.307-315
    • /
    • 2002
  • Suppose one is given a vector X of a finite set of quantities $X_i$ which are independent Poisson signals. A null hypothesis $H_0$ about E(X) is to be tested against an alternative hypothesis $H_1$. A quantity $$\sum\limits_{i}\omega_ix_i$$ is to be computed and used for the test. The optimal values of $\omega_i$ are calculated for three cases : (1) signal to noise ratio is used in the test, (2) normal approximations with unequal variances to the Poisson distributions are used in the test, and (3) the Poisson distribution it self is used. A comparison is made of the optimal values of $\omega_i$ in the three cases as parameter goes to infinity.

  • PDF

MULTIPLE DELETION MEASURES OF TEST STATISTICS IN MULTIVARIATE REGRESSION

  • Jung, Kang-Mo
    • Journal of applied mathematics & informatics
    • /
    • v.26 no.3_4
    • /
    • pp.679-688
    • /
    • 2008
  • In multivariate regression analysis there exist many influence measures on the regression estimates. However it seems to be few of influence diagnostics on test statistics in hypothesis testing. Case-deletion approach is fundamental for investigating influence of observations on estimates or statistics. Tang and Fung (1997) derived single case-deletion of the Wilks' ratio, Lawley-Hotelling trace, Pillai's trace for testing a general linear hypothesis of the regression coefficients in multivariate regression. In this paper we derived more extended form of those measures to deal with joint influence among observations. A numerical example is given to illustrate the effect of joint influence on the test statistics.

  • PDF

A Test of the Confirming Abduction Model: How Do Students Confirm Their Hypotheses During the Process of Scientific Hypothesis-Generation?

  • Jeong, Jin-Su;Kwon, Yong-Ju
    • Journal of The Korean Association For Science Education
    • /
    • v.27 no.2
    • /
    • pp.120-125
    • /
    • 2007
  • The purpose of the present study was to test the validity of the confirming abduction model (CAM). CAM is a process model which explains how reasoners confirm their hypothetical explicans. To test this model, 154 8th grade students were sampled from one middle school in Korea. Three types of vapor condensation hypothesis confirming tests were developed and administered to the subjects. The results of this study revealed that student confidence increased when hypothetical explicans were borrowed into experienced phenomena from questioning phenomena. These results validated CAM. According to CAM, the process. of confirming hypothetical explican is as follows: representing a questioning phenomenon, representing an experienced phenomenon that is similar to the questioning phenomenon, representing the hypothetical explican of the questioning phenomenon, comparing the questioning phenomenon with the experienced phenomenon, and borrowing the hypothetical explican as the hypothetical explican of the experienced phenomenon from the hypothetical explican of the questioning phenomenon. This study also discussed the implications of these findings for teaching and learning in science education.

A Study on Data Clustering Method Using Local Probability (국부 확률을 이용한 데이터 분류에 관한 연구)

  • Son, Chang-Ho;Choi, Won-Ho;Lee, Jae-Kook
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.13 no.1
    • /
    • pp.46-51
    • /
    • 2007
  • In this paper, we propose a new data clustering method using local probability and hypothesis theory. To cluster the test data set we analyze the local area of the test data set using local probability distribution and decide the candidate class of the data set using mean standard deviation and variance etc. To decide each class of the test data, statistical hypothesis theory is applied to the decided candidate class of the test data set. For evaluating, the proposed classification method is compared to the conventional fuzzy c-mean method, k-means algorithm and Discriminator analysis algorithm. The simulation results show more accuracy than results of fuzzy c-mean method, k-means algorithm and Discriminator analysis algorithm.

Implementation of Statistical Significance and Practical Significance Using Research Hypothesis and Statistical Hypothesis in the Six Sigma Projects (식스시그마 프로젝트에서 연구가설과 통계가설에 의한 통계적 유의성 및 실무적 유의성의 적용방안)

  • Choi, Sung-Woon
    • Journal of the Korea Safety Management & Science
    • /
    • v.15 no.1
    • /
    • pp.283-292
    • /
    • 2013
  • This paper aims to propose a new steps of hypothesis testing using analysis process and improvement process in the six sigma DMAIC. The six sigma implementation models proposed in this paper consist of six steps. The first step is to establish a research hypothesis by specification directionality and FBP(Falsibility By Popper). The second step is to translate the research hypothesis such as RHAT(Research Hypothesis Absent Type) and RHPT(Research Hypothesis Present Type) into statistical hypothesis such as $H_0$(Null Hypothesis) and $H_1$(Alternative Hypothesis). The third step is to implement statistical hypothesis testing by PBC(Proof By Contradiction) and proper sample size. The fourth step is to interpret the result of statistical hypothesis test. The fifth step is to establish the best conditions of product and process conditions by experimental optimization and interval estimation. The sixth step is to draw a conclusion by considering practical significance and statistical significance. Important for both quality practitioners and academicians, case analysis on six sigma projects with implementation guidelines are provided.

The Effect of Hand Massage on the Anxiety of the Hysterectomy Patients in Immediately prior to Surgery (손마사지가 자궁절제술 환자의 수술직전 불안에 미치는 효과)

  • 김정미
    • Journal of Korean Academy of Nursing
    • /
    • v.30 no.2
    • /
    • pp.476-487
    • /
    • 2000
  • The purpose of this study was to examine the effects of hand massage as a nursing intervention on the anxiety of the hysterectomy patients in immediately prior to surgery. The method of this study was Nonequivalent Control Group Non-Synchronized Design. The data were selected from at K university hospital in Pusan, and they consisted of Experimental group-25 patients, Control group -24 patients. The data were collected from Jan. 4 to Jan. 30 in 1999. The subjects′ self-reports of anxiety (measured by the Spielberger Trait-State anxiety Inventory and Visual Analogue Scale developed by Cline et al.) were recorded before and immediately after the intervention. The objective physiologic measures of blood pressure and pulse rate. The collected data were analysed by means of frequency, percentage, standard deviation, chi- square test, t-test, ANCOVA with SPSS program. The results of this study were as following; 1. Hypothesis 1: The 1st hypothesis that "There will be significant difference of the state anxiety level just before surgery in the experimental group and control group" was supported(P= .000). 2. Hypothesis 2: The 2nd hypothesis that "There will be significant difference of the visual analogue scale score just before surgery in the experimental group and control group"was supported(P= .000). 3. Hypothesis 3: The 3rd hypothesis that "There will be significant difference of the systolic and diastolic blood pressure level just before surgery in the experimental group and control group"was supported (P= .003, P= .041). 4. Hypothesis 4: The 4th hypothesis that "There will be significant difference of the pulse rate just before surgery in the experimental group and control group"was supported(P= .004). In conclusion, hand massage is a benefical nursing intervention that alleviates the psychological, physiological anxiety of the hysterectomy patients in immediately prior to surgery. therefore it is recomended to use the hand massage as a nursing intervention for patients undergoing anxiety. The results of this study appear promising, additional research is recomended to further the appropriate uses of hand massage in nursing practice for this and other patient population.

  • PDF

A Study on the Statistical Model Validation using Response-adaptive Experimental Design (반응적응 시험설계법을 이용하는 통계적 해석모델 검증 기법 연구)

  • Jung, Byung Chang;Huh, Young-Chul;Moon, Seok-Jun;Kim, Young Joong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2014.10a
    • /
    • pp.347-349
    • /
    • 2014
  • Model verification and validation (V&V) is a current research topic to build computational models with high predictive capability by addressing the general concepts, processes and statistical techniques. The hypothesis test for validity check is one of the model validation techniques and gives a guideline to evaluate the validity of a computational model when limited experimental data only exist due to restricted test resources (e.g., time and budget). The hypothesis test for validity check mainly employ Type I error, the risk of rejecting the valid computational model, for the validity evaluation since quantification of Type II error is not feasible for model validation. However, Type II error, the risk of accepting invalid computational model, should be importantly considered for an engineered products having high risk on predicted results. This paper proposes a technique named as the response-adaptive experimental design to reduce Type II error by adaptively designing experimental conditions for the validation experiment. A tire tread block problem and a numerical example are employed to show the effectiveness of the response-adaptive experimental design for the validity evaluation.

  • PDF

A tutorial on generalizing the default Bayesian t-test via posterior sampling and encompassing priors

  • Faulkenberry, Thomas J.
    • Communications for Statistical Applications and Methods
    • /
    • v.26 no.2
    • /
    • pp.217-238
    • /
    • 2019
  • With the advent of so-called "default" Bayesian hypothesis tests, scientists in applied fields have gained access to a powerful and principled method for testing hypotheses. However, such default tests usually come with a compromise, requiring the analyst to accept a one-size-fits-all approach to hypothesis testing. Further, such tests may not have the flexibility to test problems the scientist really cares about. In this tutorial, I demonstrate a flexible approach to generalizing one specific default test (the JZS t-test) (Rouder et al., Psychonomic Bulletin & Review, 16, 225-237, 2009) that is becoming increasingly popular in the social and behavioral sciences. The approach uses two results, the Savage-Dickey density ratio (Dickey and Lientz, 1980) and the technique of encompassing priors (Klugkist et al., Statistica Neerlandica, 59, 57-69, 2005) in combination with MCMC sampling via an easy-to-use probabilistic modeling package for R called Greta. Through a comprehensive mathematical description of the techniques as well as illustrative examples, the reader is presented with a general, flexible workflow that can be extended to solve problems relevant to his or her own work.

The Survey for Awareness of Radiation Dose of CT and General X-ray Examination (전산화단층촬영검사와 일반촬영검사의 방사선 선량에 대한 인식도 조사)

  • Joo, Young-Cheol;Lim, Cheong-Hwan;Jung, Hong-Ryang;You, In-Gyu;Cho, Han-Byul;Yang, Oh-Nam;Kim, Min-Cheol;Yoon, Joon
    • Journal of radiological science and technology
    • /
    • v.35 no.1
    • /
    • pp.35-44
    • /
    • 2012
  • The goal of this study is to awaken about risk occurred by CT examination. For radio-technologists working at 'S medical center' located in Seoul, we investigated a recognition about dose and risk CT and normal X-ray examination according by working experience in hospital, experience about CT examination and radiation source. For subjects of investigation, radio-technologists working at 'S medical center' located in Seoul helped us. We collected 131 questionnaires for a test of hypothesis. Cronbach @ coefficients of questionnaires were 0.825988 and 0.767161 and a rejection rate of p-value was below 0.05. SAS 9.1(SAS Institute Inc., Cary, NC, USA.) statistic package was used for hypothesis test. We used Mann-Whitney test, Kruskai-Wallis test, Two sample T-test, Two sample T-test with Bonferroni's Correction and One-way ANOVA methods. P-values of hypothesis about dose of CT and normal X-ray examination were 0.2291 ~ 0.9663. p-values of hypothesis about risk were 0.1924 ~ 1.0000. All of hypothesis is over rejection rate(<0.05). This study shows that radio-technologists of S medical center recognized that CT has higher dose and risk than general X-ray examination.

Probabilty analysis for receiver of jointly disributed AWGN Rayleigh faded signals on DS/CDMA (DS/CDMA 통신에서 AWGN Rayleigh faded 신호의 수신단의 확률적 분석)

  • 홍창우;장승용;김운경
    • Proceedings of the IEEK Conference
    • /
    • 1999.11a
    • /
    • pp.763-766
    • /
    • 1999
  • Direct-Sequence code-division multiple access(DS/CDMA) is considered by many to be a promising technology for future wireless communication networks. In this paper, we report new analysis for probability of BPSK CDMA hypothesis test in jointly distributed AWGN Rayleigh-fading received signal. In previous method, analysis is performed on AWGN or Rayleigh-faded signal in separately. In this paper, we propose model for hypothesis test system of the AWGN Rayleigh-faded received signal.

  • PDF