• Title/Summary/Keyword: testing independence

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Optimal sensor placements for system identification of concrete arch dams

  • Altunisik, Ahmet Can;Sevim, Baris;Sunca, Fezayil;Okur, Fatih Yesevi
    • Advances in concrete construction
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    • v.11 no.5
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    • pp.397-407
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    • 2021
  • This paper investigates the optimal sensor placements and capabilities of this procedure for dynamic characteristics identification of arch dams. For this purpose, a prototype arch dam is constructed in laboratory conditions. Berke arch dam located on the Ceyhan River in city of Osmaniye is one of the highest arch dam constructed in Turkey is selected for field verification. The ambient vibration tests are conducted using initial candidate sensor locations at the beginning of the study. Enhanced Frequency Domain Decomposition and Stochastic Subspace Identification methods are used to extract experimental dynamic characteristics. Then, measurements are repeated according to optimal sensor locations of the dams. These locations are specified using the Effective Independence Method. To determine the optimal sensor locations, the target mode shape matrices which are obtained from ambient vibration tests of the selected dam with a large number of accelerometers are used. The dynamic characteristics obtained from each ambient vibrations tests are compared with each other. It is concluded that the dynamic characteristics obtained from initial measurements and those obtained from a limited number of sensors are compatible with each other. This situation indicates that optimal sensor placements determined by the Effective Independence Method are useful for dynamic characteristics identification of arch dams.

Optimal sensor placement techniques for system identification and health monitoring of civil structures

  • Rao, A. Rama Mohan;Anandakumar, Ganesh
    • Smart Structures and Systems
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    • v.4 no.4
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    • pp.465-492
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    • 2008
  • Proper pretest planning is a vital component of any successful vibration test on engineering structures. The most important issue in dynamic testing of many engineering structures is arriving at the number and optimal placement of sensors. The sensors must be placed on the structure in such a way that all the important dynamic behaviour of a structural system is captured during the course of the test with sufficient accuracy so that the information can be effectively utilised for structural parameter identification or health monitoring. Several optimal sensor placement (OSP) techniques are proposed in the literature and each of these methods have been evaluated with respect to a specific problem encountered in various engineering disciplines like aerospace, civil, mechanical engineering, etc. In the present work, we propose to perform a detailed characteristic evaluation of some selective popular OSP techniques with respect to their application to practical civil engineering problems. Numerical experiments carried out in the paper on various practical civil engineering structures indicate that effective independence (EFI) method is more consistent when compared to all other sensor placement techniques.

Tests for homogeneity of proportions in clustered binomial data

  • Jeong, Kwang Mo
    • Communications for Statistical Applications and Methods
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    • v.23 no.5
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    • pp.433-444
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    • 2016
  • When we observe binary responses in a cluster (such as rat lab-subjects), they are usually correlated to each other. In clustered binomial counts, the independence assumption is violated and we encounter an extra-variation. In the presence of extra-variation, the ordinary statistical analyses of binomial data are inappropriate to apply. In testing the homogeneity of proportions between several treatment groups, the classical Pearson chi-squared test has a severe flaw in the control of Type I error rates. We focus on modifying the chi-squared statistic by incorporating variance inflation factors. We suggest a method to adjust data in terms of dispersion estimate based on a quasi-likelihood model. We explain the testing procedure via an illustrative example as well as compare the performance of a modified chi-squared test with competitive statistics through a Monte Carlo study.

Theoretical Consideration of Nondestructive Testing by use of Vertical Magnetization and Magneto-Optical Sensor

  • Lee, Jinyi;Tetsuo Shoji;Dowon Seo
    • Journal of Mechanical Science and Technology
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    • v.18 no.4
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    • pp.640-648
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    • 2004
  • This paper describes a new magnetization method for non-destructive testing with magneto-optical sensor (denoted as MO sensor) which have the following characteristic : high observation sensitivity, independence of the crack orientation, and precise imaging of a complex crack geometry such as multiple cracks. When a magnetic field is applied normally to the surface of a specimen which is significantly larger than its defects, approximately the same magnetic charge per unit area occurs on the surface of the specimen. If there is a crack in the specimen, magnetic charge per unit area has the same value at the bottom of the crack. The distribution of the vertical component of the magnetic flux density, B$\_$Z/, is almost uniform over the no-crack area (denoted as B$\_$Z,BASE/), while the magnetic flux density is smaller in the surroundings of the crack(denoted as B$\_$Z,CRACK/) If B$\_$Z, BASE/ is a bit larger than the saturated magnetic flux density of the MO sensor (B$\_$s/) , then small magnetic domains occur over the crack area and a large domain over the non-crack area because B$\_$Z,CRACK/ is smaller than B$\_$s/.

The Adolescent's Sex Role Identity and Perceived Parent Behaviors (청년기 자녀의 성역할 정체감과 부모의 양육행동과의 관계)

  • 박선영
    • Journal of the Korean Home Economics Association
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    • v.27 no.4
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    • pp.139-150
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    • 1989
  • The present study was designed to answer the following questions: 1) Is there and relationship between the adolescent's sex role identity and perceived parent behavious? 2) Is there any gender differences in perceived parent behavious? 3) Is there any interaction effect between sex role identity and gender in perceived parent behaviors? 109 male and 101 female undergraduates from the five universities in Seoul served as subjects in this investigation. Subjects were administered the Parent Behavior From (PBF) and the Bem Sex Role Inventory (BSRI) in counterbalanced order. A4 (sex-role identity)×2(gender) multivariate analysis of variance was performed for the perceived paternal and maternal behaviors separately. The simultaneous confidence intervals for pairwise comparison were followed when the MANOVA was significant. In testing all hypotheses, .05 was used as a significance level in this study. For the perceived paternal behavious, 1) The androgynous group, compared with the undifferentiated group, reported greater father warmth, active involvement, greater encouragement of cognitive independence, cognitive curiosity, cognitive competence, achievement control, and conformity. 2) The androgynous individuals showed higher father warmth, congitive independence, curiosity, and cognitive competence than the feminine individuals. 3) The androgynous individuals were found to have significantly higher father warmth than the masculine individuals. For the perceived maternal behaviors, there was a significant difference between gender groups in conformity. Daughters reported higher conformity than sons. The interaction effect between sex-role identity and gender, however, was not found to be significant.

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An approach based on clustering for detecting differentially expressed genes in microarray data analysis

  • Yuki Ando;Asanao Shimokawa
    • Communications for Statistical Applications and Methods
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    • v.31 no.5
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    • pp.571-584
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    • 2024
  • To identify differentially expressed genes (DEGs), researchers use a testing method for each gene. However, microarray data are often characterized by large dimensionality and a small sample size, which lead to problems such as reduced analytical power and increased number of tests. Therefore, we propose a clustering method. In this method, genes with similar expression patterns are clustered, and tests are conducted for each cluster. This method increased the sample size for each test and reduced the number of tests. In this case, we used a nonparametric permutation test in the proposed method because independence between samples cannot be assumed if there is a relationship between genes. We compared the accuracy of the proposed method with that of conventional methods. In the simulations, each method was applied to the data generated under a positive correlation between genes, and the area under the curve, power, and type-one error were calculated. The results show that the proposed method outperforms the conventional method in all cases under the simulated conditions. We also found that when independence between samples cannot be assumed, the non-parametric permutation test controls the type-one error better than the t-test.

Test-Retest Method on Short Form Sasang Classification Questionnaire for American (SF_SSCQ-A) : Pilot Study (미국인 체질진단지 : 검사-재검사법)

  • Yoo, Jung-Hee;Lee, Eui-Ju;Park, Jin-Son;Hahn, Suk-Kyun;Lee, Jun-Hee;Kho, Byung-Hee
    • Journal of Sasang Constitutional Medicine
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    • v.21 no.1
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    • pp.79-84
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    • 2009
  • 1. Objectives This study was proposed to use the test-retest method to verify the independence and agreement between the questions (Short Form Sasang Classification Questionnaire for American ; SF_SSCQ-A). 2. Methods The questionnaire was administered to 50 American and they were asked to complete the questionnaire again two weeks after the first administration. The final subjects are 42 except of 5 dropouts and 3 insufficient respondents. A reliability analysis for each individual question was conducted using the test-retest method to verify the independence and agreement between the questions. To verify independence, a Chi-square test with crosstabs analysis and p-values was used. The agreement verification was conducted by using the Cohen kappa coefficient. In addition, the constitutional variable was defined as the constitutional attribute of each question, and Pearson's correlation coefficient was confirmed after testing the scale. 3. Results and Conclusions The test-retest method showed that Pearson's correlation coefficients for the results of the two tests ranged from 0.66 to 0.87. The Chi-square test results indicated that there are 7 independent item. Among the other 114 questions, the agreement test revealed that 88 questions (70.5%) showed above common agreement.

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Deterministic Execution Testing for Concurrent Programs based on Automata (오토마타기반의 병행 프로그램을 위한 결정적 수행 테스팅 기법)

  • Chung, In-Sang;Kim, Byeong-Man;Kim, Hyeon-Soo
    • Journal of KIISE:Software and Applications
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    • v.28 no.10
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    • pp.706-719
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    • 2001
  • In this paper, we present a new approach to deterministic execution for testing concurrent programs. The proposed approach makes use of the notion of event independence which has been used in the partial-order method in order to resolve the state-explosion problem and constructs and automation which accepts all the sequences semantically equivalent to a given sequence. Consequently, we can allow a program to be executed according to event sequences other then the (possibly infeasible) given sequence if they have the same effects on the program's behavior. One advantage of this method is that it can be applied to situations where a program is not exactly implemented as described in the specification.

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Proposal of pulse parameter useful for pulse wave analysis in oriental medicine: Preliminary study on floating and sinking pulses (통계분석을 통한 한의 맥진에 유용한 파라미터 도출: 부침맥을 중심으로 한 예비연구)

  • Lee, Jeon;Lee, Yu-Jung;Lee, Hae-Jung;Choi, Eun-Ji;Kim, Jong-Yeol
    • Proceedings of the KIEE Conference
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    • 2006.10c
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    • pp.244-246
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    • 2006
  • In this study, we search some parameters well-related to floating-sinking pulse by statistical analysis, because these pulses are frequently used in clinic. Pulse signals were acquired by 3D pulse analyzer and 30 subjects consist of 15 people diagnosed as floating pulse and 15 people diagnosed as sinking pulse by oriental doctors who have over 5 years clinical experience. Then, we made a representative beat template for each subject and, through a peak detection algorithm, we calculated several pulse parameters. To find the parameters related to floating-sinking pulse, we performed statistical testing with 17 parameters through the independence sampling, t-test. As a result, there is the biggest difference between pressure, the maximum pulse pressure, diastolic area(Ad) and float-sink data. (p < .05).

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Examination of the Impact of Blood Groups on Group Participation

  • Asgari, Omid
    • The Journal of Industrial Distribution & Business
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    • v.6 no.2
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    • pp.25-30
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    • 2015
  • Purpose - Could blood type provide the key to wellness and affect our personality? The theory that blood type is linked to personality (and other mental and physical qualities) is popular mostly in Japan, although it has carried over to Taiwan and South Korea. Research Design, Data, and Methodology - Questionnaires were distributed to 380 production line company employees. The reliability and validity of the questionnaires were examined through independence testing and the average ratio comparison of the two populations. Additionally, using Pearson's chi-square formula, the relationship between the blood group (independent variable) and general group participation (dependent variable) was tested along with the Schuprow coefficient. Result - The prioritization of blood groups over the general group participation was identified and the following results were obtained: Individual group participation is affected by personality features derived from temperament, mood, and other characteristics. Conclusion - The study showed that individual blood groups have an effect on their group cooperation, and among blood groups, blood group A had the greatest tendency to group participation, followed by blood groups O, AB, B, respectively.