• Title/Summary/Keyword: Consecutive tests

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Run related probability function and their application to start-up demonstration tests

  • Bi, Yi-Ming;Oh, Jung-Taek;Cho, Gyo-Young
    • Journal of the Korean Data and Information Science Society
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    • v.27 no.4
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    • pp.1067-1074
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    • 2016
  • A start-up demonstration test is a mechanism that is usually used to determine the reliability of equipment, for example water pumps, car batteries and power generators. The simplest and oldest start-up demonstration tests are called CS (consecutive successes) which have been studied by Hahn and Gage (1983), Viveros and Balakrishnan (1993).At first Hahn and Gage (1983) discussed the start-up demonstration test. I was based on i.i.d (independently and identically distributed) binary outcomes with the specified number of consecutive successful start-ups. Oh (2016) studied CSNCF (consecutive successful, but not consecutive failures). In this paper, we investigated the CS and CSNCF models, also their applications to start-up demonstration tests. The numerical results showed that the expectations and variances of the total number of attempted start-ups until the acceptance of the unit are gradually increasing in all of the specified number of successes as the p (probability of a successful start-up in an single trial) decreases from 0.99 to 0.90. The difference between means of the CS mode and CSNCF model is small, but variances of the CS and CSNCF are big.

Detecting Multiple Outliers Using the Gaps of Order Statistics

  • Kim, Hyun Chul
    • Communications for Statistical Applications and Methods
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    • v.2 no.2
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    • pp.184-197
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    • 1995
  • An objective and one-step detection procedure of multiple outliers is suggested by using the gaps of the order statistics. The detection procedure can be used as a routine outlier detection method of a statistical analysis computer program. The procedure is applied to some examples including the data selected by Kitagawa.

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ONLINE TEST BASED ON MUTUAL INFORMATION FOR TRUE RANDOM NUMBER GENERATORS

  • Kim, Young-Sik;Yeom, Yongjin;Choi, Hee Bong
    • Journal of the Korean Mathematical Society
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    • v.50 no.4
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    • pp.879-897
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    • 2013
  • Shannon entropy is one of the widely used randomness measures especially for cryptographic applications. However, the conventional entropy tests are less sensitive to the inter-bit dependency in random samples. In this paper, we propose new online randomness test schemes for true random number generators (TRNGs) based on the mutual information between consecutive ${\kappa}$-bit output blocks for testing of inter-bit dependency in random samples. By estimating the block entropies of distinct lengths at the same time, it is possible to measure the mutual information, which is closely related to the amount of the statistical dependency between two consecutive data blocks. In addition, we propose a new estimation method for entropies, which accumulates intermediate values of the number of frequencies. The proposed method can estimate entropy with less samples than Maurer-Coron type entropy test can. By numerical simulations, it is shown that the new proposed scheme can be used as a reliable online entropy estimator for TRNGs used by cryptographic modules.

An Improved Method for Detection of Moving Objects in Image Sequences Using Statistical Hypothesis Tests

  • Park, Jae-Gark;Kim, Munchurl;Lee, Myoung-Ho;Ahn, Chei-Teuk
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 1998.06b
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    • pp.171-176
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    • 1998
  • This paper resents a spatio-temporal video segmentation method. The algorithm segments each frame of video sequences captured by a static or moving camera into moving objects (foreground) and background using a statistical hypothesis test. In the proposed method, three consecutive image frames are exploited and a hypothesis testing is performed by comparing two means from two consecutive difference images, which results in a T-test. This hypothesis test yields change detection mask that indicates moving areas (foreground) and non-moving areas (background). Moreover, an effective method for extracting object mask form change detection mask is proposed.

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Correlation between Subscapularis Tears and the Outcomes of Physical Tests and Isokinetic Muscle Strength Tests

  • Jang, Ho-Su;Kong, Doo-Hwan;Jang, Suk-Hwan
    • Clinics in Shoulder and Elbow
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    • v.19 no.2
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    • pp.90-95
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    • 2016
  • Background: The aim of this study was to investigate the correlation between the type of subscapularis tendon tears diagnosed during arthroscopy and the outcomes of physical tests and of isokinetic muscle strength tests. Methods: We preoperatively evaluated physical outcomes and isokinetic muscle strength of 60 consecutive patients who underwent an arthroscopic rotator cuff repair and/or subacromial decompression. We divided the patients into five groups according to the type of subscapularis tear, which we classified using Lafosse classification system during diagnostic arthroscopic surgery. Results: When we performed a trend analysis between the outcomes of the physical tests and the severity of subscapularis tendon tear, we found that both the incidence of positive sign of the collective physical tests and that of individual physical tests increased significantly as the severity of the subscapularis tear increased (p<0.001). Similarly, the deficit in isokinetic muscle strength showed a tendency to increase as the severity of subscapularis tear increased, but this positive correlation was statistically significant in only the deficit between those with Lafosse type II tears and those with Lafosse type III tears. Conclusions: Although no single diagnostic test surpasses above others in predicting the severity of a subscapularis tear, our study implies that, as a collective unit of tests, the total incidence of the positive rate of the physical tests and the extent of isokinetic strength deficit may correlate with severity of subscapularis tears.

A Study on Unsaturated Zone Characterization and Feasibility of Soil Vapor Extraction at a DNAPL-contaminated Site in Korea

  • Lee, Man Na Mi;Yeo, In Wook
    • Journal of Soil and Groundwater Environment
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    • v.18 no.6
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    • pp.48-55
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    • 2013
  • This study aimed at characterizing unsaturated zone at the source zone area contaminated by DNAPL and investigating feasibility of soil vapor extraction (SVE). Five boreholes with three multi-level screens at the depth of 3.0~4.5 m, 5.5~7.0 m, and 8.0~12.0 m were installed at the source zone. Pneumatic tests were performed to determine the permeability of porous medium. Permeability was estimated to be 81.6 to 203.7 darcy, depending on the applied solutions, which was contradicted by grain size analysis of cored soil samples leading to 3.51 darcy. This is due to air flow through gravel pack during the early stage of pneumatic test. Pressure-drawdown curve in the late stage also well showed the leaky aquifer type, indicating air leakage to the ground. Air flow tests were also carried out to investigate air flow connectivity between multi-level wells, indicating that the horizontal air flow was well developed between the lower screens of the wells, not between the upper and middle screens due to the leakage to the surface. For the SVE test, there was no noticeable variation in TCE vapor concentration between three different test runs: 1. 8 hours daily for 5 days, 2. 24 hours together with air blowing at another well (BH1), 3. five consecutive days. Even for five-day consecutive test, total amount of removed TCE was estimated only to be as low as 46.5 g.

Numerical Investigation for Cumulative Damage Assessment of a One-way RC Slab subjected to Consecutive Explosions (전산수치해석을 이용한 일방향 철근콘크리트 슬래브의 연속폭발 누적피해 평가기법 연구)

  • Ji, Hun;Sung, Seung-Hun;Chong, Jin Wung;Choi, Yoon Soo
    • Journal of the Korea Society for Simulation
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    • v.29 no.2
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    • pp.119-127
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    • 2020
  • This study numerically investigated a structural behavior subjected to consecutive explosions. To this end, a small scale one-way reinforced slab (RC) with fixed-fixed boundary condition was considered as the target structure, and a commercial software, LS-DYNA, was utilized for finite element (FE) analysis. Prior to performing FE analysis, preliminary tests were carried out to verification of a computational model for the one-way RC slab. In the numerical simulation, identical blast loads were consecutively applied to the structure, and cumulative damage assessment were carried out based on its maximum dynamic displacements. As a result of the numerical simulation, it was found that maximum displacements considering permanent deformation due to a prior explosion were almost linearly increased in every explosion until the hazardous damage threshold.

Comparative Analysis of Regional and At-site Analysis for the Design Rainfall by Gamma and Non-Gamma Family (I) (Gamma 및 비Gamma군 분포모형에 의한 강우의 지점 및 지역빈도 비교분석 (I))

  • Ryoo, Kyong-Sik;Lee, Soon-Hyuk
    • Journal of The Korean Society of Agricultural Engineers
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    • v.46 no.4
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    • pp.25-36
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    • 2004
  • This study was conducted to derive the design rainfall by the consecutive duration using the at-site frequency analysis. Using the errors, K-S tests and LH-moment ratios, Log Pearson type 3 (LP3) and Generalized Extreme Value (GEV) distributions of Gamma and Non-Gamma Family, respectively were identified as the optimal probability distributions among applied distributions. Parameters of GEV and LP3 distributions were estimated by the method of L and LH-moments and the Indirect method of moments respectively. Design rainfalls following the consecutive duration were derived by at-site frequency analysis using the observed and simulated data resulted from Monte Carlo techniques. Relative root-mean-square error (RRMSE) and relative efficiency (RE) in RRMSE for the design rainfall derived by at-site analysis in the observed and simulated data were computed and compared. It has shown that at-site frequency analysis by GEV distribution using L-moments is confirmed as more reliable than that of GEV and LP3 distributions using LH-moments and Indirect method of moments in view of relative efficiency.

Clinical Study on Safety and Efficacy of JiSaiXin (Recombinant Human Granulocyte Colony Stimulating Factor Injection Manufactured in China) for Chinese Undergoing Chemotherapy

  • Wang, Lin;Huang, Xin-En
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.1
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    • pp.299-301
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    • 2015
  • Objectives: To assess safety and efficacy of JiSaiXin (Recombinant Human Granulocyte Colony Stimulating Factor Injection manufactured in China, G-CSF) 150ug per day for three days and whether this regimen could reduce the incidence of febrile neutropenia caused by chemotherapy. Method: From July 2014 to December 2014 patients treated by chemotherapy in our hospital were randomly divided into two groups: Group A with prophylactic use of G-CSF (JiSaiXin) 24 hours after chemotherapy for consecutive 3 days; and Group B with G-CSF (JiSaiXin) after neutropenia. Routine blood tests were performed 7 days and 14 days after chemotherapy. Results: A total of 100 patients fulfilled study criteria, and the incidence of severe neutropenia (grade III/IV) and the incidence of febrile neutropenia in Group A were lower than those in Group B. Nine patients were found severe neutropenia (grade III/IV) in Group B, but one in Group A, three febrile neutropenia in Group B, but 0 in Group A. Conclusions: This study suggested that prophylactic use of G-CSF (JiSaiXin) 150ug per day 24 hours after chemotherapy for consecutive 3 days is safe and could be effective for preventing febrile neutropenia in patients with chemotherapy.

Effects of Foot Mats on Levels of Fatigue, Discomfort, Lower Extremity Edema and Skin Temperature in Scrub Nurses (발매트 적용이 수술실 소독간호사의 피로도, 불편감, 하지 부종 및 피부온도에 미치는 영향)

  • Hwang, Soon Hee;Jun, Sang-Eun
    • Journal of Korean Clinical Nursing Research
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    • v.21 no.3
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    • pp.309-318
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    • 2015
  • Purpose: The purpose of this study was to examine the effects of foot mats on reducing levels of fatigue, discomfort, lower extremity edema and skin temperature in scrub nurses during surgery. Methods: This study employed one group repeated measures design in which 16 scrub nurses (ages 22-38) stood on steel footstools (SF) during scrub as the conventional test and stood on SF with foot mats as the experimental test. Levels of fatigue, discomfort, lower extremity edema and skin temperature were measured before the first surgical hand scrub and right after the first surgery of the day for 3 consecutive days in both tests. Results: The changes in levels of fatigue and discomfort were significantly different between tests (p<.001~.033). Edema, determined by the differences in circumferences of the ankles and calves before and after the surgery was also significantly different between groups (p=.001~.011). However, the change in skin temperature on the foot tops of both feet was not different between tests (p=.351~.467). Conclusion: The results of this study show that using foot mats on top of the steel footstool is effective in reducing the levels of fatigue, discomfort and lower extremity edema in scrub nurses during surgery.