• Title/Summary/Keyword: T-test

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

  • Kim, Seock-Hyun;Heo, Wook;Lee, Hyun-Woo
    • Journal of Industrial Technology
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    • v.27 no.B
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    • pp.59-64
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    • 2007
  • This study introduces an environmental noise evaluation procedure and results for a wind turbine (W/T) system. Test and evaluation are required by the international standard IEC 61400-11 in the aspect of environmental effect. Test and evaluation are performed on U-50 WT model which is first developed by the domestic W/T manufacturer. W/T test model is under operation in Daekwanryung wind test site. An integrated monitoring system in the test site is utilized for the evaluation. With the noise signal, meteorological data and W/T operational data are monitored in real time by the integrated monitoring system using LabVIEW. From the measured noise data, acoustic power level are estimated and compared with those of other similar size WT under the wind speeds required by international standard.

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T.P.H.A Positive Rate of General and Ordinary Health Examine (일반(一般) 정기(定期) 건강진단자(健康診斷者)의 T.P.H.A양성율(陽性率))

  • Lee, Hoa-Suk;Lee, Soo-Young;Kim, Kang-Seuck
    • The Journal of the Korean life insurance medical association
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    • v.2 no.1
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    • pp.253-259
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    • 1985
  • In medical selection of Daehan Education Insurance, for 6 months from June 1st, 1984 to November 30th, 1984 we examined 2523 persons, who were supposed to receive general test and Normal subject test Then we did syphilis test by selecting the way of R.P.R. card test and repeatedly confirming the examination serologically. The results are as follows: 1) As results of R.P.R. card test, 30 out of 1592 males are positive(1.89%) and 10 out of 931 females are positive(1.1%). 40 out of total 2523 persons are positive(1.6%). 2) As results of T.P.H.A, 28 out of 1592 males are positive(1.76%) and 9 out of 931 females are positive. 37 out of total 2523 persons are positive(1.47%). 3) When R.P.R. card test is compared with T.P.H.A test, 40 persons by R.P.R. showed that 2 males and female are negative and only 37 persons are positive in T.P.H.A test. And so the result agreement rate of R.P.R. card test and T.P.H.A test showed 92.5%. 4) In the age-distribution males have high positive rates in 30's and 40's and females have high positive rates in 20's and 40's when the subjects are normal.

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Power Test of Trend Analysis using Simulation Experiment (모의실험을 이용한 경향성 분석기법의 검정력 평가)

  • Ryu, Yongjun;Shin, Hongjoon;Kim, Sooyoung;Heo, Jun-Haeng
    • Journal of Korea Water Resources Association
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    • v.46 no.3
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    • pp.219-227
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    • 2013
  • Time series data including change, jump, trend and periodicity generally have nonstationarity. Especially, various methods have been proposed to identify the trend about hydrological time series data. However, among various methods, evaluation about capability of each trend test has not been done a lot. Even for the same data, each method may show the different result. In this study, the simulation was performed for identification about the changes in trend analysis according to the statistical characteristics and the capability in the trend analysis. For this purpose, power test for the trend analysis is conducted using Men-Kendall test, Hotelling-Pabst test, t test and Sen test according to the slope, sample size, standard deviation and significance level. As a result, t test has higher statistical power than the others, while Mann-Kendall, Hotelling-Pabst, and Sen tests were similar results.

A Test Data Generation Tool based on Inter-Relation of Fields in the Menu Structure (메뉴 구조의 필드간의 상호 연관관계를 기반으로 한 테스트 데이타 자동 생성 도구)

  • 이윤정;최병주
    • Journal of KIISE:Computing Practices and Letters
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    • v.9 no.2
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    • pp.123-132
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    • 2003
  • The quality certification test is usually conducted by a certifying organization to determine and guarantee the quality of software after the software development phase, commonly without the actual source code, but with by going against the product's manual. In this paper, we implement a Manual-based Automatic Test data generating tool: MaT, the test technique based on manual, that automatizes producing the test data from analysis data of software package and manual. The input data of MaT are the result of the analysis of software and manual. We propose 'menu-based test analysis model' in order to generate the input data. We believe that the proposed technique and tool he]p improving quality and reliability of the software.

Field Empirical Result Analysis According to the Operation Reliability Test of the Wireless Gas Shut-off Device (무선가스 차단 장치 동작 신뢰성 시험에 따른 현장 실증 결과분석)

  • Hwang, Do-Yeon;Lee, Kyung-Sik
    • Journal of the Korean Institute of Gas
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    • v.25 no.5
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    • pp.70-77
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    • 2021
  • As IoT technology develops along with the 4th industrial revolution, gas safety products to which IoT technology is applied are being developed. However, since the gas safety system was not allowed, system improvement and operation reliability test for IoT gas safety products are required. This thesis researches IoT fuse cock and smart multi-function meter among IoT gas safety products, and analyzes the empirical data of IoT fuse cock to secure operational reliability data, thereby becoming a leader in IoT gas safety products. It aims to develop gas barrier technology one step further through various test evaluations and methods in the future.

Effects of Public Health Center Hypertension Health School Program on Hypertension-related Knowledge, Self-care Behavior, Quality of life and Physiological Parameters in Hypertensive patients (보건소 고혈압 건강교실 프로그램이 고혈압 환자의 고혈압관련 지식, 자가간호행위, 삶의 질 및 생리적 지수에 미치는 영향)

  • Chang, Koung-Oh
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.11
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    • pp.236-247
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    • 2016
  • The purpose of this study was to examine the effects of health program s on hypertension in a public health center located in Y-si. Most interesting were the effects on hypertension-related knowledge, self-care behavior, quality of life, and physiological parameters for hypertensive patients. Nonequivalent control group pretest-posttest design was employed. A total of 48 patients with hypertension living in Y-si were assigned to either the experimental group (n=23) or the control group (n=25). The experimental group was provided with an 8-week health program on hypertension between August 31 and October 23 in 2015. Data were analyzed with SPSS/WIN 21.0 using descriptive statistics, ${\chi}^2$-test, Fisher's exact test, and t-test. The result indicated a significant difference between the experimental group and the control group with respect to the scores of hypertension-related knowledge (t=-3.76, p<.001), self-care behavior (t=-3.33, p=.002), physiological parameters, including systolic blood pressure (t=6.27, p<.001) and diastolic blood pressure (t=4.70, p<.001), total cholesterol levels (t=3.08, p=.003), and Abdominal circumference (t=2.52, p=.015). We conclude that the self-group program on hypertension has a significant effect on the change of hypertension-related knowledge and self-care behavior for hypertensive patients.

The Effect of Horticultural Activities Program on Emotional Intelligence and Stress Coping in Nursing College Student (원예활동프로그램이 간호대학생의 정서지능과 스트레스 대처에 미치는 효과)

  • Yang, Kyung-Mi;Park, Hyun-Jung
    • Journal of the Korea Convergence Society
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    • v.9 no.2
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    • pp.267-276
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    • 2018
  • The purpose of this study was to verify the effectiveness of horticultural activities program for 4th grade nursing students' emotional intelligence and stress coping. The study method was a non-equivalent control group pretest-posttest design. Participants were recruited with 4th grade nursing students from two nursing colleges. They were assigned to the experimental group (n=29) or the control group (n=30) using a computerized blocked randomization. Horticultural activities program was consisted of 10 sessions which were 2 times a week for 80 mins at each session during 5 weeks. Pretest and posttest were used to measure emotional intelligence and stress coping using the same structured questionnaires. Data was analyzed using frequency analysis, descriptive statistics, ${\chi}^2-test$, t-test, Fisher's exact test, Kolmogorov-Smirnov, independent t-test and paired t-test. The result showed a significant difference that the experimental group's emotional intelligence(t=-3.33, p=.002) and stress coping(t=-2.35, p=.023) score was higher than the control group's. The results of this study suggests that the horticultural activities program is effective in terms of emotional intelligence and stress coping for $4^{th}$ grade nursing students.

A Wald Test for a Unit Root Based on the Symmetric Estimator

  • Jong Hyup Lee;Dong Wan SHin
    • Communications for Statistical Applications and Methods
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    • v.4 no.3
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    • pp.677-683
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    • 1997
  • For an AR(1) model with intercept $y_t=\mu+\rho{y_{t-1}}+e_t$, a test for random walk hypothesis $H_0:(\mu, \rho)=(0, 1)$is proposed, which is based on the symmetric estimator. In the vicinity of the null, the test in shown to be more powerful than the test of Dickey and Fuller(1981) based on the ordinary least squares estimator.

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The Improvement Effects of Soft Ground by Quick Lime Pile (생석회파일에 의한 연약지반개량효과)

  • 천병식;고갑수;장은석;임지섭;이용한
    • Proceedings of the KSR Conference
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    • 1999.05a
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    • pp.383-389
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    • 1999
  • This paper is a study on the improvement effects by quick lime pile through theoretical analysis and in-situ construction test. Effects of strength increase is studied to verify the improvement effects of soft ground arounding quick lime pile. First, engineering characteristics of quick lime and ground was studied, in the second place, laboratory test(consolidation test, triaxial compression test) and in-situ test(portable cone penetration test, vane test) were peformed for verification of strength increase of adjacent ground. Finally, the results of in-situ test were compared with those of theorecal study. From in-situ test results, strength at 28th curing days(6.11-6.55t/㎡) was twice as great as strength before improvement(3.06t/㎡) and was slightly greater than theoretical value(4.95t/㎡).

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Flight Test of Propulsion System for Verifying Engine/Aircraft Compatibility of T-50 Advanced Trainer (T-50 고등 훈련기 엔진/기체 적합성 검증을 위한 추진계통 비행시험)

  • Lee, Sang-Hyo;Jeong, In-Myon;Jung, Joo-Hyun;Shim, Jae-Kwang;Kang, Sung-Soo;Park, Sung-Hwan;Han, Byoung-Hak;Moon, Hyung-Rae;Cha, Jae-Byoung;Lee, Boo-ll
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.35 no.10
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    • pp.948-956
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    • 2007
  • It is important during FSD(Full Scale Development) period to verify whether the aircraft system function meets the aircraft requirements and functional performance. Especially, the functionality of the integrated propulsion system should be verified to evaluate the compatibility with aircraft. Various flight tests such as the engine airstart test, the engine horsepower extraction test, the backup throttle functionality test had been performed to evaluate the engine/aircraft compatibility with T-50 during FSD period. Through such flight tests, it was confirmed that the propulsion system of T-50 was properly designed and installed to the aircraft. This paper shows description on each flight test item, test procedure and test results. It is expected that this paper could be a reference for preparing the propulsion flight test in other aircraft developments.