• Title/Summary/Keyword: hypothesis testing problem

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Exact poisson distribution in the use of NPB with aiming errors

  • Kim, Joo-Hwan
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1995.04a
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    • pp.967-973
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    • 1995
  • A neutral particle beam(NPB) aimed at the object and receive a small number of neutron signals at the detector to estimate the mass of an object Since there is uncertainty about the location of the axis of the beam relative to the object, we could have aiming errors which may lead to incorrect information about the object. Under the two assumptions that neutral particle scattering distribution and aiming errors have a circular normal distribution respectively, we have derived an exact probability distribution of neutral particles. It becomes a Poison-power function distribution., We proved monotone likelihood ratio property of tlis distribution. This property can be used to find a criteria for the hypothesis testing problem.

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k-Sample Rank Tests for Umbrella Location-Scale Alternatives (k-표본 우산형 위치-척도 대립가설에 대한 순위검정법의 연구)

  • Hee Moon Park
    • The Korean Journal of Applied Statistics
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    • v.7 no.2
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    • pp.159-171
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    • 1994
  • Some rank score tests are proposed for testing the equality of all sampling distribution functions against umbrella location-scale alternatives in k-sample problem. Only the case of known peak $\ell$ is considered. Under the null hypothesis and a contiguous sequence of unbrella location-scale alternatives, the asymptotic properties of the proposed test statistics are investigated. Also, the asymptotic local powers are compared with each others. The results show that the tests based on the Chen-Wolfe rank analogue statistic are more powerful than others for unequally spaced umbrella location-scale alternatives and robust.

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Goodness-of-Fit Test Based on Smoothing Parameter Selection Criteria

  • Kim, Jong-Tae
    • Communications for Statistical Applications and Methods
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    • v.2 no.1
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    • pp.122-136
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    • 1995
  • The objective of this research is to investigate the problem of goodness-of-fit testing based on nonparametric density estimation with a data-driven smoothing parameter. The small and large sample properties of a new test statistic $\hat{\lambda_a}$ is investigated. The test statistic $\hat{\lambda_a}$ is itself a smoothing parameter which is selected to minimize an estimated MISE for a truncated series estimator of the comparison density function. Therefore, this test statistic leads immediately to a point estimate of the density function th the event that $H_0$ is rejected. The limiting distribution of $\hat{\lambda_a}$ is obtained under the null hypothesis. It is also shown that this test is consistent against fixed alternatives.

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Comparison of Two-time Homogeneous Poisson Processes Using Inverse Type Sapling Plans (역샘플링법을 이용한 포와슨과정의 비교)

  • 장중순;임춘우;정유진
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.11 no.17
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    • pp.67-80
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    • 1988
  • This study is concerned with the comparison of two time homogeneous Poisson processes. Traditionally, the methods of testing equality of Poisson processes were based on the binomial distribution or its normal approximations. The sampling plans used in these methods are to observe the processes concurrently over a predetermined time interval, possibly different for each process. However, when the values of the intensities of the processes are small, inverse type sampling plans are more appropriate since there may be cases where only a few or even no events are observed in the predetermined time interval. This study considers 9 inverse type sampling plans for the comparison of two Poisson processes. For each sampling plans considered, critical regions and the design parameters of the sampling plan are determined to guarantee the significance level and the power at some values of the alternative hypothesis. The Problem of comparing of two Weibull processes are also considered.

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Moving Estimates Test for Jumps in Time Series Models

  • Na, O-Kyoung;Lee, Seon-Joo;Lee, Sang-Yeol;Choi, In-Bong
    • Communications for Statistical Applications and Methods
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    • v.13 no.2
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    • pp.205-217
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    • 2006
  • In this paper, we consider the problem of testing for a change of the parameter function ${\theta}(t)$ that may have a discontinuity at some unknown point ${\tau}$. We introduce a varying-h moving estimate to test the null hypothesis that ${\theta}(t)$ is continuous against the alternative that ${\theta}({\tau}-){\neq}{\theta}({\tau}+)$. Simulation results are provided for illustration.

Nonparametric analysis of income distributions among different regions based on energy distance with applications to China Health and Nutrition Survey data

  • Ma, Zhihua;Xue, Yishu;Hu, Guanyu
    • Communications for Statistical Applications and Methods
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    • v.26 no.1
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    • pp.57-67
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    • 2019
  • Income distribution is a major concern in economic theory. In regional economics, it is often of interest to compare income distributions in different regions. Traditional methods often compare the income inequality of different regions by assuming parametric forms of the income distributions, or using summary statistics like the Gini coefficient. In this paper, we propose a nonparametric procedure to test for heterogeneity in income distributions among different regions, and a K-means clustering procedure for clustering income distributions based on energy distance. In simulation studies, it is shown that the energy distance based method has competitive results with other common methods in hypothesis testing, and the energy distance based clustering method performs well in the clustering problem. The proposed approaches are applied in analyzing data from China Health and Nutrition Survey 2011. The results indicate that there are significant differences among income distributions of the 12 provinces in the dataset. After applying a 4-means clustering algorithm, we obtained the clustering results of the income distributions in the 12 provinces.

An Exploratory Study on the Project Performance by PMO Capability (PMO 역량에 따른 프로젝트 성과에 관한 연구)

  • Bae, Jae-Kwon;Kim, Jin-Hwa;Kim, Sang-Yeoul
    • Asia pacific journal of information systems
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    • v.18 no.1
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    • pp.53-77
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    • 2008
  • In recent years, although numbers of corporations are bringing in PMO, they seem to be indifferent to PMO performance measurement. This demonstrates that there are also other reasons beside performance measurement of information systems (IS) project being ambiguous by introducing PMO; the lack of acknowledging the concrete function of PMO, and the scarcity of empirical study about the effect of PMO on the project members and project performance. In this sense, this study is aimed at proposing a new research model in which project success factors (i.e., standardization, management advocacy, and staff expertise) affect PMO capability (i.e., knowledge management, resources management, and problem solving competency) positively, leading to project performance (i.e., task outcomes, psychological outcomes, and organizational outcomes) eventually. To empirically test the research model, data are surveyed from PMO department and IS department. To prove the validity of the proposed research model, PLS analysis is applied with valid 132 questionnaires. By employing PLS technique, the measurement reliability and validity of research variables are tested and the path analysis is conducted to do the hypothesis testing. The path analysis results can be organized into 7 ways in large scale. First, standardization of project success factors has a positive association with knowledge management, resources management, and problem solving competency of PMO capabilities. The findings of this result indicate that the multiple or single project management should satisfy standardization in order to operate an effective PMO. Second, management advocacy of project success factors has a positive association with knowledge management, resources management, and problem solving competency. Management advocacy refers to the willingness of management to provide the required resources and authority for project success. There is agreement among researchers regarding the importance of management advocacy for favorable PMO capability. Third, staff expertise of project success factors has a positive association with knowledge management, resources management, and problem solving competency. The findings of this result indicate that the formation of an exceptional consultant or members with a proficient knowledge for staff expertise of project member is the key factor to elevate the PMO capability. Past research suggests that experience and knowledge and the resultant familiarity with the problem faced can be an important determinant of PMO capability. A capable project with appropriate staff expertise means that it enjoys a diversity of abilities and experiences. Fourth, knowledge management competency of PMO capabilities has a positive impact on psychological outcomes but has no direct effect on task outcomes and organizational outcomes. In domestic case of S. Korea, PMO was finally introduced to many other corporations in 2005 though it started bringing in 2000. Therefore, it had neither a significant impact on the task outcomes nor organizational outcomes by lacking the contents and the infrastructure of the knowledge management because the knowledge consolidation and management period of PMO is comparatively shorter by terms than other foreign nations. Fifth, resources management competency of PMO capabilities has a positive association with task outcomes, psychological outcomes, and organizational outcomes. In addition, problem solving competency of PMO capabilities has a positive association with task outcomes, psychological outcomes, and organizational outcomes. Therefore, the findings of this results stress that PMO capabilities has a positive impact on project performance. Sixth, according to the path analysis of the hypothesis, which suggested in this research, problem solving competency is the PMO capability which is the key success factor for task, psychological, and organizational outcomes as an integrated performance model. Further, the analysis reveals that problem solving competency is an important factor for integrated performance model. The finding is in line with past IS research, which affirms that the work of IS projects is essentially a problem solving endeavor. Seventh, in the path analysis of the hypothesis in this research, the path of the management advocacy $\rightarrow$ problem solving competency $\rightarrow$ organizational outcomes appears to be the most important and strongest path. In brief, the finding of this study suggests that project success factors influence PMO capability positively, and project performance as well. From the results, it can be concluded that PMO helped great improve the project success rate and project performance. This study advances research on PMO capability in three important aspects. First, the findings of our study have implications for IS theory and future research. Our study contributes to IS theory by synthesizing concepts from PMO research and project management research with those in IS research. We proposed and tested PMO capability of IS projects and the findings of our investigation provided some preliminary answers to some of the questions raised. Secondly, this thesis does not only help depicting the concept of IT governance but also approaches empirically. It makes a gradual approach to the main content, step by step, in contrary of simple standard, scholastic way of thinking. Finally, we argued that this task-oriented(technical) view is not sufficient to adequately conceptualize IS project performance. Hence, we applied that the research on organization teams, which provides a flip viewpoint to that of project management research in that it gives more weight for psychological outcomes of organizational work groups, can be very helpful in reconceptualizing the IS project performance construct. The limitations of this study are also discussed to provide research directions for future research.

A Study on the Inquiring Experimental Assessment in Biology of Applicants for Entrance Examination to A Korean Private High School (고등학교 장학생 선발고사 응시생의 탐구적 생물실험 평가에 관한 연구)

  • Hong, Jung-Lim;Pak, Sung-Jae;Chang, Nam-Kee
    • Journal of The Korean Association For Science Education
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    • v.17 no.2
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    • pp.201-207
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    • 1997
  • This study was performed to survey the achievements in problem solving by the inquiring experiment, which was done by the superior group in the traditional cocepts-centered written tests. The purpose of this study was to identify characteristics of inquiring experimental assessment by analyzing differences between concepts-centered written and inquiring experimental tests. The subjects of this study was 211 applicants. They are the superior group of the 9th grade students, and score in the top 1% of total achievements percentage in school. They also have passed the primary entrance examination. The inquiring experimental test was developed according to the curriculum in school, and is composed of 5 subcategories: problem-perception and formulating hypothesis, designing an experiment, carring out an experiment, recording data and drawing conculsion, and generalizing conculsions and communicaton. The checklists of each subcategory were made and testing methods were divided into observation and report. The major results of this study are as follows: 1. The achievements in each subcategory of inquiring experimental performance were very low in the superior group who took the concepts-centered written tests. 2. The results of factor and correlation analyses in this study confirmed the abilities measured by inquiring experimental assessment differed from abilities measured by existing tests. These results indicated that even students who achieved high in scientific knowledge, these abilities were not automatically transformed inquiry process which many other abilities were integrated into. Therefore, problem solving ability requires integrated abilities which are fostered by inquiring experimental tasks. This suggests that new instrument for assessment must be developed to measure integrating ability especially where scientifically gifted students are selected, or where entrance examinations to the science schools are administered.

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Influential Factors for SMEs of Environmentally Friendly Management in Chinese Distribution Industry

  • CUI, Yuan;BAO, Youjian;CAI, Yunwei;KIM, Seung-Woon
    • Journal of Distribution Science
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    • v.20 no.4
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    • pp.65-75
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    • 2022
  • Purpose: Environmental pollution problems have become more and more serious, how to effectively protect the environment has become a hot spot of concern to all sectors of society. The way to solve this problem is environmentally friendly management. However, theoretical perspectives and research frameworks of existing research on environmentally friendly management are still unclear. This study aims to examine how the CEO's beliefs for SMEs of Chinese distribution industry affect the environmentally friendly management based on institutional theory. Research design, data, and methodology: This paper collected data from 215 SMEs in China distribution industry and conducted a series of data analysis and hypothesis testing based on an institutional theory perspective using Amos and SPSS to verify the effects of regulatory pressure, normative pressure, and imitation pressure on firms' environmentally friendly management. Results: Through the analysis, this paper tests that normative pressure and imitative pressure have a positive effect on CEO's beliefs. However, regulatory pressure did not have a significant effect on beliefs of CEO. Meanwhile, the degree of CEO's beliefs has a positive effect on environmentally friendly management in Chinese distribution SMEs. Conclusions: Theoretical contributions, practical implications, and future research directions are discussed.

Using ICT in the HEIs in the Study of the Philological Sciences

  • Iryna, Kominiarska;Roman, Dubrovskyi;Inna, Volianiuk;Natalya, Yanus;Oleksandr, Hryshchenko
    • International Journal of Computer Science & Network Security
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    • v.22 no.5
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    • pp.31-38
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    • 2022
  • The article highlights the educational potential of information and communication technologies in the study of philological disciplines in higher education institutions. The study aims to analyze the didactic potential of ICT in the study of philological disciplines, as well as to check the scientific hypothesis that the use of ICT in HEIs in the study of philological disciplines will intensify and enhance the effectiveness of the learning process. To confirm the validity of the hypothesis, experimental testing was carried out and the results are illustrated in the article. The above-mentioned goal of the study determined the use of theoretical and empirical methods: analysis, synthesis, generalization, and systematization of pedagogical and scientific-methodological literature to clarify the state of research problem development and to identify pedagogical foundations on which the process of ICT use is based, comparison and prediction; questioning and testing of educational process participants to understand the effectiveness of ICT use in their training in HEIs. The research results showed positive changes in all analyzed criteria in the experimental group, which is due to the introduction of additional ICT tools into the educational process of the mentioned group. The scientific novelty of the study consists in highlighting the main characteristics and didactic functions of ICT in the learning process of philological students; in covering the classification of ICT, ICT tools, and typology of training sessions using ICT in the study of philological disciplines. In the conclusion it is summarized that the introduction of modern ICT in the educational process allows intensifying the learning process, implementation of a variety of ideas, increases the pace of classes and material assimilation, influencing the motivation for learning, increases the amount of independent work of students.