• Title/Summary/Keyword: T-test analysis

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A Study on the Reliability Analysis for Smoke Detector using Dust (분진을 이용한 연기감지기 신뢰성 분석에 관한 연구)

  • Hong, Sung Ho;Choi, Moon Soo;Lee, Young Man
    • Journal of the Korean Society of Safety
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    • 제28권6호
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    • pp.11-16
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    • 2013
  • This paper presents a study on the analyzing reliability of smoke fire detector using accelerated life test. In general, the smoke fire detector is broken by dust which flow in smoke detection chamber. In order to conduct accelerated life test of smoke fire detector dust is set accelerated factor in this paper. The dust is fly-ash which is test particle 5th regulated by KS A 0090. The dust accelerated level is 60 g, 180 g and 360 g and failure time is measured by smoke sensitivity testing. It is considered to failure of detector if detector don't operate within 30 secconds when subjected to an air stream having a velocity of 20 cm/s~40 cm/s containing smoke with a concentration of 15% of rate of light-response of 1 m. The goodness of fit test and mean life prediction conduct using the failure time. The result show that life distribution fits the weibull distribution for failure time data and the mean lifes calculate 22.5 year in domestic product and 14.7 years in overseas product applied dust stress only.

A Clinical Study on the Correlation between Spine Deformity and Foot Abnormality (척추변형과 족부병변의 임상적 상관관계)

  • Choi, Hyun-Im;Park, Hung-Ki;Ju, Mu-Yeol
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • 제10권1호
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    • pp.117-128
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    • 2004
  • I have processed all the data by using SPSS PC+. And my research process was investigated for 34 students on the Forward Bending Test, Foot Printer Test, Feedoscope Test, X-ray Test and so on. The object of this thesis is to study the correlation between spine deformity and foot abnormality in a theoretical and empirical method. The main results of this study were as follows: 1. There was statistical significance on the correlation between foot length and spine length. 2. Spinal curve is the smallest on the pes plannus group and the biggest on the pes cavus group without statistical significance. 3. Left lumbar curve is the smallest, and right thoracic spine curve is the biggest on the left foot pattern group with statistical significance. 4. On the foot weight bearing groups, there was statistical significance both of between left and right foot groups. 5. There was no statistical significance on the t-test analysis between left and right foot area according to spinal curve typology. But there was tendency that thoracic spine curve is bigger in the same side of the foot area and lumbar spine curve is bigger in the opposite side of foot area.

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Internal Pattern Matching Algorithm of Logic Built In Self Test Structure (Logic Built In Self Test 구조의 내부 특성 패턴 매칭 알고리즘)

  • Jeon, Yu-Sung;Kim, In-Soo;Min, Hyoung-Bok
    • Proceedings of the KIEE Conference
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    • 대한전기학회 2008년도 제39회 하계학술대회
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    • pp.1959-1960
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    • 2008
  • The Logic Built In Self Test (LBIST) technique is substantially applied in chip design in most many semiconductor company in despite of unavoidable overhead like an increase in dimension and time delay occurred as it used. Currently common LBIST software uses the MISR (Multiple Input Shift Register) However, it has many considerations like defining the X-value (Unknown Value), length and number of Scan Chain, Scan Chain and so on for analysis of result occurred in the process. So, to solve these problems, common LBIST software provides the solution method automated. Nevertheless, these problems haven't been solved automatically by Tri-state Bus in logic circuit yet. This paper studies the algorithm that it also suggest algorithm that reduce additional circuits and time delay as matching of pattern about 2-type circuits which are CUT(circuit Under Test) and additional circuits so that the designer can detect the wrong location in CUT: Circuit Under Test.

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A Review on the Regionalization Methodology for Core Inlet Flow Distribution Map

  • Lee, Byung-Jin;Jang, Ho-Cheol;Cheong, Jong-Sik;Baik, Se-Jin;Park, Young-Sheop
    • Nuclear Engineering and Technology
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    • 제33권4호
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    • pp.441-456
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    • 2001
  • ABB-CE's regionalization methodology for the core inlet flow distribution map is reviewed. This methodology merges the test data of fuel assembly locations which are either in symmetry or strongly correlated with others. It increases the number of available test data for each regional flow factor It makes up effectively for the deficiency due to limited number of test data. It also contributes to making the core inlet flow distribution smoother not only locally but also over the entire core, and to relieving the impacts of test errors that may happen due to some do- calibrated local pressure measurement taps. As a result, the core inlet How distribution data becomes more statistically useful and thus the conservatism involved in handling the core inlet flow factors for the thermal margin analysis is expected to be reduced. Meanwhile, the regionalized map may lose the unique local characteristics in core inlet flow distribution too much. By an alternative approach introduced in the present work, it is shown that such a disadvantage can be mitigated somewhat if the engineering judgement is made more

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Vibration Ride Quality Optimization of a Suspension Seat System Using Genetic Algorithm (유전자 알고리즘을 이용한 SUSPENSION SEAT SYSTEM의 진동 승차감 최적화)

  • Park, S.K.;Choi, Y.H.;Choi, H.O.;Bae, B.T.
    • Proceedings of the KSME Conference
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    • 대한기계학회 2001년도 춘계학술대회논문집B
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    • pp.584-589
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    • 2001
  • This paper presents the dynamic parameter design optimization of a suspension seat system using the genetic algorithm. At first, an equivalent 1-D.O.F. mass-spring-damper model of a suspension seat system was constructed for the purpose of its vibration analysis. Vertical vibration response and transmissibility of the equivalent model due to base excitations, which are defined in the ISO's seat vibration test codes, were computed. Furthermore, seat vibration test, that is ISO's damping test, was carried out in order to investigate the validity of the equivalent suspension seat model. Both analytical and experimental results showed good agreement each other. For the design optimization, the acceleration transmissibility of the suspension seat model was adopted as an object function. A simple genetic algorithm was used to search the optimum values of the design variables, suspension stiffness and damping coefficient. Finally, vibration ride performance test results showed that the optimum suspension parameters gives the lowest vibration transmissibility. Accordingly the genetic algorithm and the equivalent suspension seat modelling can be successfully adopted in the vibration ride quality optimization of a suspension seat system.

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The Effects of Career Education Program On Elementary Schooler's Career Maturity and Self-Concept (진로 교육 프로그램이 초등학생의 진로 성숙과 자아개념에 미치는 영향)

  • Seo, Hyeon-Jung
    • The Korean Journal of Elementary Counseling
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    • 제4권1호
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    • pp.99-122
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    • 2005
  • The purpose of this study was to find out the effects of a career education program during a discretional activity class in elementary school. It established the following questions to achieve the objectives. First, does a career education program In a discretional activity class have an effect on elementary schooler's career maturity? Second, does a career education program in a discretional activity class make an influence on elementary schooler's self-concept? To settle these subjects, it assigned two classes in 5th grade of A elementary school, city of Anyang, Gyeonggi-do, experiment group and control group. It was applied the experiment group a career education program. As for measurement, it was used career maturity level test for elementary and middle schoolers' and 'the self-concept diagnostic test'. It was examined career maturity and self-concept of the groups through the pre-test post-test, applying cross-tabulation analysis to career choices pattern and t-test to career maturity level and self-concept. The results were as follows: First, students of experiment group showed meaningful differences in career choice pattern, career choice attitude, and career choosing skills compared to control group, and that presented a career education program made a positive impact on elementary schooler's career maturity. Second, it showed that there was a significant difference in self-concept, showing students of experiment group took better place. it is believed that a career education program had a potent influence on the self-concept of elementary students.

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Effects of Group Training Based on the Health Belief Model on Knowledge and Behavior Regarding the Pap Smear Test in Iranian Women: a Quasi-Experimental Study

  • Shobeiri, Fatemeh;Javad, Masoumeh Taravati;Parsa, Parisa;Roshanaei, Ghodratollah
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권6호
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    • pp.2871-2876
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    • 2016
  • The Pap smear test is recommended for early diagnosis of cervical cancer. The aim of this study was to assess knowledge and behavior regarding the Pap smear test based on the Health Belief Model (HBM) in women referred to premarital counseling classes, Hamadan, Iran. This quasi-experimental study was conducted on 330 women, who were allocated randomly to two case and control groups (n=165). Two educational session classes were performed in the case group. Two stages in before and after intervention groups were evaluated. Analysis of data was performed by SPSS/16.0, using t-test, $x^2$, and McNemar's test. P-values <0.05 were regarded as significant. There was no significant difference between the mean scores of the various structures of this model in two groups before the intervention. However, after the intervention there were significant increase in mean score of knowledge and all variables of HBM in the intervention group(P<0.001). The findings of this study highlight the important role of education about cervical cancer on changing women's beliefs about cervical screening.

Identification of Differentially Expressed Genes Using Tests Based on Multiple Imputations

  • Kim, Sang Cheol;Yu, Donghyeon
    • Quantitative Bio-Science
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    • 제36권1호
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    • pp.23-31
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    • 2017
  • Datasets from DNA microarray experiments, which are in the form of large matrices of expression levels of genes, often have missing values. However, the existing statistical methods including the principle components analysis (PCA) and Hotelling's t-test are not directly applicable for the datasets having missing values due to the fact that they assume the observed dataset is complete in general. Many methods have been proposed in previous literature to impute the missing in the observed data. Troyanskaya et al. [1] study the k-nearest neighbor (kNN) imputation, Kim et al. [2] propose the local least squares (LLS) method and Rubin [3] propose the multiple imputation (MI) for missing values. To identify differentially expressed genes, we propose a new testing procedure when the missing exists in the observed data. The proposed procedure uses the Stouffer's z-scores and combines the test results of individual imputed samples, which are dependent to each other. We numerically show that the proposed test procedure based on MI performs better than the existing test procedures based on single imputation (SI) by comparing their ROC curves. We apply the proposed method to analyzing a public microarray data.

The Effects of a Smoking Cessations Health Camp among Adolescent Smokers (청소년 흡연자를 위한 금연건강캠프의 효과)

  • Paek, Kyung-Shin;Kwon, Young-Sook
    • Journal of East-West Nursing Research
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    • 제16권2호
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    • pp.105-112
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    • 2010
  • Purpose: This study was aimed at evaluating the effects of a smoking cessations health camp on levels of expiratory Carbon Monoxide concentration, self-efficacy, smoking knowledge and nicotine dependence among adolescents smokers. Methods: This research uitlized a one group pre-test post-test design. The smoking cessations health camp was developed after considering cognitive and behavioral aspects and was provided for two days and one night. The number of subjects was 31 high school students. Data were analyzed using descriptive analysis and paired t-test. Results: As compared to a pre-test, the average score of expiratory CO concentration and nicotine dependence were significantly lower and the average score of smoking knowledge was significantly higher in a post-test. An increase in the mean score of self-efficacy was not statistically significant. Conclusion: These results suggest that this smoking cessations health camp can provide teen smokers with the insightful antismoking information and an opportunity for anti-smoking practices. Therefore, this smoking cessations health camp can be effective and useful for adolescent smokers in other school settings.

Analysis of Interoperability Test between a Different Kind of Train Control System (이종(異種) 열차제어시스템간의 상호운영성 시험 분석)

  • Baek, Jong Hyen;Seul, Nam-O
    • Journal of Korea Entertainment Industry Association
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    • 제5권1호
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    • pp.122-126
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    • 2011
  • In this paper, for the purpose of improving the future domestic train control systems and securing interoperability according to the global development trends of train control systems, we present the test results of interoperability between wayside train control system installed in existed line, and the onboard train control system. Due to the safety-critical characteristics of train systems, the site test in the section where the wayside equipment is installed, leads to a danger against safety. Therefore, by way of constructing a simulation environment of train control systems, we confirm the T/R data systems of the equipment for interoperability and test the interoperability by applying these systems to onboard equipment.