• Title/Summary/Keyword: Tests

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Nonparametric test procedures the changepoint problem with multiple observations (다중자료를 갖는 변화시점 모형에서의 비모수적인 검정법)

  • 김경무
    • The Korean Journal of Applied Statistics
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    • v.4 no.1
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    • pp.33-45
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    • 1991
  • In the analysis of changepoint model the situation where single observation is taken at each time point has been considered. In an effort to extend this to the general situation, we may consider the changepoint model with more than one observation at each time point. These tests are developed without assuming any particular form for the underlying distribution, we propose the one-sided and two-sided nonparametric tests by extending the tests that have been considered in the changepoint model with single observation at each time point and obtain their asymptotic null distributions. We compare the empirical powers among the extended changepoint tests under one-sided or two-sided alternatives. We also compare the powers of the extended changepoint tests with those of the original test via the Monte Carlo simulation.

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Investigation on Exact Tests (정확검정들에 대한 고찰)

  • 강승호
    • The Korean Journal of Applied Statistics
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    • v.15 no.1
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    • pp.187-199
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    • 2002
  • When the sample size is small, exact tests are often employed because the asymptotic distribution of the test statistic is in doubt. The advantage of exact tests is that it is guaranteed to bound the type I error probability to the nominal level. In this paper we review the methods of constructing exact tests, the algorithm and commercial software. We also examine the difference between exact p-values obtained from exact tests and true p-values obtained from the true underlying distribution.

Quantile-based Nonparametric Test for Comparing Two Diagnostic Tests

  • Kim, Young-Min;Song, Hae-Hiang
    • Communications for Statistical Applications and Methods
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    • v.14 no.3
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    • pp.609-621
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    • 2007
  • Diagnostic test results, which are approximately normal with a few number of outliers, but non-normal probability distribution, are frequently observed in practice. In the evaluation of two diagnostic tests, Greenhouse and Mantel (1950) proposed a parametric test under the assumption of normality but this test is inappropriate for the above non-normal case. In this paper, we propose a computationally simple nonparametric test that is based on quantile estimators of mean and standard deviation, instead of the moment-based mean and standard deviation as in some parametric tests. Parametric and nonparametric tests are compared with simulations under the assumption of, respectively, normality and non-normality, and under various combinations of the probability distributions for the normal and diseased groups.

Biomechanics of Sacroiliac Joint Dysfunction and Clinical Disease (엉치엉덩관절 통증과 임상 질환에 대한 생체역학)

  • Jeong, Seong-Gwan;Lee, Woo-Hyung;Kim, Kyung-Hwan
    • PNF and Movement
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    • v.8 no.1
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    • pp.41-50
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    • 2010
  • Pain originating from the sacroiliac joint(SIJ) has been associated with poor performance, yet specific diagnosis of sacroiliac dysfunction(SID) has been difficult to achieve. Clinical presentation of SID appears that pain and poor performance is responsive to local analgesia of periarticular structures with poorly defined pathology, and poor performance with bony pathological changes present as a result of chronic instability. Previous research indicates that physical examination cannot diagnose SIJ pathology. Earlier studies have not reported sensitivities and specificities of composites of provocation tests known to have acceptable inter-examiner reliability. Tests based on mechanics as manual provocation for SIJ pain have formed the basis of tests used to diagnose SIJ dysfunction. In this review summary, the purpose of this study was to describe the sacroiliac tests with a model of examination, diagnosis, and management of SID. Further research is warranted to determine whether SIJ tests is reliable means of evaluating innominate impairments.

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State-of-the-Art on the Experiment Studies for Evaluating Piping Integrity under Seismic Loading Conditions (지진 하중조건에서 배관 건전성 평가를 위한 실험적 연구 현황)

  • Kim, Jin Weon;Kim, Jong Sung;Kim, Yun Jae;Kweon, Hyeong Do
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.13 no.1
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    • pp.16-39
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    • 2017
  • This paper reviewed and summarized the experimental studies conducted during last three decades to evaluate the structural integrity and to establish the acceptance criteria for piping system of nuclear power plants (NPPs) under seismic loading condition. These experimental studies contain the results of large-scale piping system tests under excessive seismic loading as well as standard specimen tests, simplified piping specimen tests, and piping components tests under simplified dynamic and cyclic loading. These would be useful as a basis for establishing integrity assessment procedure and acceptance criteria for piping systems of NPPs under beyond design basis earthquake (BDBE) conditions, and also could be used in planing the scope and direction of further related researches.

A Study on Estimation of Bearing Capacity of Sand Compaction Pile by Centrifuge Model Tests (원심모형실험에 의한 모래다짐말뚝의 지지력 산정식 연구)

  • Yoo, Nam-Jae;Hong, Young-KiI;Jun, Sang-Hyun;Kim, Kyung-Soo
    • Journal of Industrial Technology
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    • v.27 no.A
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    • pp.121-130
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    • 2007
  • Centrifuge model tests were performed to find appropriate equations proposed previously of estimating the bearing capacity of the composite clayey soil reinforced with sand compaction pile. Model tests were carried out with changing the replacement ratio of SCP (20%, 40%, 70%), contents of fine materials (5%, 10%, 15%) and ratio of treated width to loading width (1B, 2B, 3B). Test results about bearing capacity of the composite ground were obtained by performing the surcharge load tests with measurements of applied loads and vertical displacement. Bearing capacities against bulging and shear failures were estimated by the existing equations. As results of comparing the estimated bearing capacity with experimental values the bearing capacities estimated by Greenwood's equation (1970) for bulging failure mode were similar to the test results.

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An Investigation of Breakwater Stability by Centrifuge Model Tests (원심모형실험을 이용한 방파제의 안정성 검토)

  • Yoo, Nam-Jae;Hong, Young-Gil;Kim, Dong-Gun
    • Journal of Industrial Technology
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    • v.32 no.A
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    • pp.79-86
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    • 2012
  • In this paper, centrifuge model tests and numerical analysis on the breakwater structure were performed to investigate the stability and behavior of breakwater in field. In centrifuge model tests, construction sequence of breakwater structure such as preparation of weathered rock and sand deposit, construction of D.C.M, rubble mound with crushed stones and installment of breakwater structure was reconstructed like field condition and the behavior of ground settlement and breakwater displacement during stage of construction was observed during tests. For the final stage of simulating the horizontal movement of breakwater due to wave force, horizontal load was applied by horizontal loading apparatus being specially designed so that horizontal displacement of structure could be observed. Numerical analysis were also carried out and its results were compared with test results to assess the property of centrifuge model tests with respect to the behavior of structure as well as ground.

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Goodness-of-fit Tests for the Weibull Distribution Based on the Sample Entropy

  • Kang, Suk-Bok;Lee, Hwa-Jung
    • Journal of the Korean Data and Information Science Society
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    • v.17 no.1
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    • pp.259-268
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    • 2006
  • For Type-II censored sample, we propose three modified entropy estimators based on the Vasieck's estimator, van Es' estimator, and Correa's estimator. We also propose the goodness-of-fit tests of the Weibull distribution based on the modified entropy estimators. We simulate the mean squared errors (MSE) of the proposed entropy estimators and the powers of the proposed tests. We also compare the proposed tests with the modified Kolmogorov-Smirnov and Cramer-von-Mises tests which were proposed by Kang et al. (2003).

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Neuropsychological Tests in Psychiatric Outpatients (정신과 외래 환자에서의 신경 심리 검사)

  • Lee, Sung-Hoon;Park, Hee-Jung;Park, Hye-Jung;Lee, Hee-Sang;Kim, Chan-Hyung
    • Sleep Medicine and Psychophysiology
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    • v.4 no.1
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    • pp.120-128
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    • 1997
  • Clinical neuropsychological tests were developed originally for the diagnosis of neurological and neuro-surgical diseases. Recently, these tests are being introduced to psychiatric patients. Authors had the experience to use these tests in pychiatric outpatient clinic. Results were as follows. There was a significantly increase in language and attentional function in residual schizophrenia compared to normal control. In chronic neurosis, as visuospatial function was reduced, language and attentional functions were enhanced. With these results, authors suggest that application of neuropsychological tests in psychiatric patients may be very helpful in classifying the subgroups of disease, in selecting the modality of treatment, and in expecting prognosis.

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Centrifuge Model Tests for the Slope Reinforcement Effect (사면 보강효과 확인을 위한 원심모형실험)

  • 박용원;김병일;박종호;홍성수
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.10a
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    • pp.521-528
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    • 2002
  • This paper presents the results of centrifuge model tests on the reinforced slope by pressure grouting. Tests were performed to investigate the reinforcing effect of grouting. In the tests, slopes of scale factor 1/10 were used changing the space and number of reinforcing bar. Test results are as tile follows; 1. The reinforcing effect increase rapidly with reinforcement area ratio at low value of reinforcement area ratio. 2. At high reinforcement area ratio the increase ratio of reinforcing effect decrease. 3. At same reinforcement area ratio, the reinforcing effect of double reinforcing bar was larger than the single reinforcing bar due to arching effect.

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