• Journal of the Korean Statistical Society
• /
• 제25권1호
• /
• pp.123-131
• /
• 1996

The problerm of testing for a constant mean is considered. A Kolmogorov-Smirnov type test using the sample Fourier coefficients is suggested and its asymptotic distribution is derived. A simulation study shows that the proposed test is more powerful than the cusum type test when there is more than one change-point or there is a cyclic change.

• Journal of Mechanical Science and Technology
• /
• 제15권7호
• /
• pp.1002-1012
• /
• 2001

The work reported here is an extensive study of tendon response to multiple cyclic tests including 3% constant peak strain level test (A-type test), 3% constant peak strain level test with two rest periods (B-type test), and 3∼4% different peak strain level test (C-type test). A sufficient number of specimens were tested at each type of the test to statistically evaluate many changes in response during testing and differences in response between each type of the test. In cyclic tests, there were decreses (relaxations) in the peak stresses and hysteresis, increases in the slack strains, and during lower peak strain level (3%) cyclic block after higher peak strain level (4%) cyclic block in the C-type tests. Considering the results of this study and those of the other study of multiple cyclic tests with rest periods by Hubbard and Chun, 1985, recovery phenomena during the rest periods occurred predominantly at the beginning of the rest periods. Consistently in both studies, the effects of rest periods were small and transient compared to the effects of the cyclic extensions. The recovery with cycles at lower peak strain level (3%) after higher peak strain level (4%) in the C-type test has not been previously documented. This recovery seems to be a natural phenomena in tissue behavior so that collagenous structures recover during periods of decreased demand.

• Nuclear Engineering and Technology
• /
• 제23권2호
• /
• pp.174-182
• /
• 1991

안전계통의 이용불능도 및 최적시험주기 평가에 있어서 주기적인 시험과 관련된 인간실수의 영향을 고려하였다. 시험 및 보수와 관련된 인간실수는 건전한 계통이 시험 후 잘못된 상태에 놓이게 될 가능성과(Type A인간실수)건전하지 못한 계통이 시험시 감지되지 못할 가능성(Type B인간실수)이다. 계통이용불능도 및 최적시험주기에 미치는 인간실수의 영향을 결정하기 위하여 안전계통의 이용불능도를 계산하기 위한 사상수목모델이 개발되었다. 또한 안전주입계통의 신뢰도 분석을 통하여 계통전체에 미치는 영향을 평가하였다. 다양한 민감도 분석 결과, (1) 계통이용불능도는 인간실수의 확률이 커질수록 증가하며 Type A인간실수의 영향이 훨씬 크다. (2) 최적시험주기 는 Type A 인간실수가 커 질수록 약간 증가하나, Type B 인간실수가 커 질수록 감소한다. (3) 안전주입펌프의 시험주기를 고정시키면 안전주입계통의 이용불능도는 Type A인간실수가 커질수록 크게 증가하나 Type B 인간실수가 커지더라도 약간 증가한다. 따라서 인간실수의 영향을 고려 할 때 계통의 이용불능도를 일정 수준으로 유지하기 위해서는 시험주기(최적시험주기가 아님 )를 줄여야 한다. 그리고 시험 및 보수시 Type A 인간실수는 계통의 이용불능도에 미치는 영향이 크므로, 특히 TyPe A 인간실수를 줄이기 위한 노력이 필요하다.

• 영어어문교육
• /
• 제16권4호
• /
• pp.153-184
• /
• 2010

On the bases of the 5 principles and the 4 criteria for designing and developing of the listening and the reading test of National English Ability Test (NEAT), this study presents Item-Types Decision-Making Model as a blueprint for designing and constructing the two tests. It sets up the criteria for validating item types, designs a modular type of test specifications, constructs an item-types bank, and specifies a complementary type of test specifications of the two tests. To gather all these threads up, it constructs Item-Types Decision-Making Model which consists of such components as the item-type pool, the validity criteria and the procedures of testing item types, the item-types bank, the modular and the complementary type test specification. Thus, it shows how the Model works in developing and constructing the two level-differentiated listening and reading tests (the 2nd and the 3rd rank) of NEAT. Finally, it discusses some implications and applications of the Model to the two level-differentiated tests (the A and the B type) of 2014 CSAT (College Scholastic Ability Test) systems, National Assessment of Educational Achievement (NAEA), and classroom testing. In conclusion, Item-Types Decision-Making Model functions as a testing template in an item development system and as a matrix in an item-types bank system.

• 한국태양에너지학회 논문집
• /
• 제33권5호
• /
• pp.82-88
• /
• 2013

There are the stirring test and drain test in the daily performance test to determine the thermal performance of a domestic solar hot water system. The drain test is a test that measures the discharge heating rate while drain the hot water from the top of the storage tank and supply the city water to the bottom of the tank. From the perspective of the user, this drain test is more effective than the stirring test. In this study, the thermal performance were compared through the drain test for a passive type and an active type domestic solar hot water systems consisting of the same storage tank and collectors. At this point, a passive type was used the horizontal storage tanks, and an active type was used vertical storage tank. In the drain test, when the hot water drained up to the reference hot water temperature, an active type which have vertical storage tank represents excellent daily performance than a passive type which have horizontal storage tank regardless of weather conditions. The reason for this is because the vertical storage tank is advantageous to thermal stratification in the tank. After the drain test, the residual heat for the horizontal storage tank was much more than the vertical storage tank, but in the next day the amount of discharged heat were less than the those of vertical storage tank neither. Thus, the solar water heating system which have horizontal storage tank should be adopted preheating control method rather than separate using control method when connected with auxiliary heat source device.

• Journal of Advanced Marine Engineering and Technology
• /
• 제27권6호
• /
• pp.776-782
• /
• 2003

This paper describes a newly developed double squirrel cage induction motor in which the rotor is located outside the stator. The outside rotor type brushless dc motor has been used for VTR's head drum and PC's cooling fan, but this kind of induction motor has not been developed yet. The parameters of outside rotor type induction motor were measured from the locked rotor test and no load test. It is possible to determine the parameters which are presented in the steady-state equivalent-circuit of the outside rotor type induction motor. Load test of induction motor was carried out using a dynamometer. For the characteristics of torque, efficiency, power factor and output. the developed double squirrel cage induction motor is compared with the ordinary induction motor It is believed that the results of this paper can be used for the development of the outside rotor type induction motor.

• 한국자동차공학회논문집
• /
• 제6권1호
• /
• pp.73-79
• /
• 1998

For the design and development of the wheel type excavator, the dynamic effects of travelling on the performance of the equipment should be first analyzed and conside- red in the initial design stage. In order to test the durability of the equipment in a short period, th travelling test should be performed over accelerated durability test tracks. which is more severe than general field roads such as city road, paved road, unpaved road and rough road. In this paper, a parametric study is performed in order to determine important design parameters of durability test track of a wheel type excavator. A rigid body model is developed using DADS and dynamic analysis is performed for the equipment travelling over several test roads with different severity. A comparison of test and analysis results is also presented.

• 한국치위생학회지
• /
• 제10권6호
• /
• pp.1025-1035
• /
• 2010

Objectives : The purpose of this study was to identify correlation of personality preference, and achievement goal orientation, academic self-efficacy, test anxiety in selecting college students who majored in dental hygiene. This study also provides a basic data regarding personality for education of dental hygiene students. Methods : 192 students of S college who majored in dental hygiene were asked to answer the MBTI GS form, academic self-efficacy scale, achievement goal orientation scale and test anxiety scale during the month of May, 2009. The total of 160 copies were analyzed. MANOVA, independent-sample t-test were conducted. Results : 1. Looking at distribution of personality preference type of the students, extroversion type (63.1%) was more than introversion type(36.9%), sensing type(87.5%) was more than intuition type(12.5%), thinking type(54.4%) was more than feeling type(45.6%), judging type(59.4%) was more than perceiving type (40.6%) 2. In subscale of achievement goal orientation, performance approach level was higher in extroversion type than in introversion type. Performance avoidance level was lower in extroversion type than in introversion type. However, other preference personality type didn't show any significant difference in subscale of achievement goal orientation. 3. Academic self-efficacy was higher in extroversion type and thinking type than in introversion type and feeling type. There wasn't any significant difference between judging type and perceiving type, sensing type and intuition type. 4. In subscale of academic self-efficacy, confidence was higher in extroversion type than in introversion type. Task difficulty preference and self-regulated efficacy were higher in thinking type than in feeling type. 5. There wasn't any significant difference between personality preference type and test anxiety. Conclusions : Professor should find out difference between students through using information of preference personality and develop a teaching strategy that can encourage strength and make up weakness of each students.

• Journal of the Korean Data and Information Science Society
• /
• 제16권3호
• /
• pp.609-620
• /
• 2005

In the secondary data analysis for categorical data, situations often arise in which the estimated cell variances are available, but not the full matrix of variances. In this case researchers are often inclined to use Pearson-type test statistics for homogeneity. However, for a complex sample observed cell proportions are not distributed as multinomial and Pearson-type test statistic generally is not distributed asymptotically as chi-square distribution. This paper evaluates powers for Wald test and Pearson-type test and the first order corrected test of Pearson-type test for homogeneity. The resulting power curves indicate that as the misspecification effect increases, the amount of inflation of significance level and the loss of power Pearson-type test are getting more severe.

• 한국신뢰성학회지:신뢰성응용연구
• /
• 제17권1호
• /
• pp.50-57
• /
• 2017

Purpose : This paper is a comparative analysis results of the fatigue test for dental implants and accelerated life test by using a static type loading device commonly used in Korea and a dynamic type loading device (universal-joint) recommended by FDA. Methods : Fatigue tests of dental implant is based on ISO 14801 and classified into static load test and dynamic load test. The tests were carried out on three test specimens by four load stress steps under each loading device. For analysis on failure mode such as crack, fracture and permanent deformation of test specimens, we used X-ray three-dimensional computed tomography on test specimens before and after the fatigue tests. The design of the accelerated life test was based on the analysis results of the fatigue life data obtained from the dynamic load test and the statistical analysis software (Minitab ver.15) was used to analyze the appropriate life distribution. Results : As a result of the fatigue tests and the accelerated life tests at same acceleration condition under each test method, the fatigue life under the dynamic type loading device (universal-joint) was shorter than when static type loading device was applied. Conclusion : This paper can be used as a reference when the universal-joint type loading device for implants fatigue test is applied as ISO 14801.