• Title/Summary/Keyword: T-test analysis

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Brittle fracture analysis of the offset-crack DCDC specimen

  • Ayatollahi, M.R.;Bagherifard, S.
    • Structural Engineering and Mechanics
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    • v.29 no.3
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    • pp.301-310
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    • 2008
  • Applications of fracture mechanics in the strength analysis of ceramic materials have been lately studied by many researchers. Various test specimens have been proposed in order to investigate the fracture resistance of cracked bodies under mixed mode conditions. Double Cleavage Drilled Compression (DCDC) specimen, with a hole offset from the centerline is a configuration that is frequently used in subcritical crack growth studies of ceramics and glasses. This specimen exhibits a strong crack path stability that is due to the strongly negative T-stress term. In this paper the maximum tensile stress (MTS) criterion is employed for investigating theoretically the initiation of brittle fracture in the DCDC specimen under mixed mode conditions. It is shown that the T-stress has a significant influence on the predicted fracture load and the crack initiation angle. The theoretical results suggest that brittle fracture in the DCDC specimen is controlled by a combination of the singular stresses (characterized by KI and KII) and the non-singular stress term, T-stress.

Effect of Sopung-tang and tDCS on Motor function Recovery and GDNF Expression in Photothrombotic Brain Infarction Induced Rat Model (광혈전 유도 뇌손상 백서에서 소풍탕(疏風湯)과 tDCS의 적용이 운동기능회복과 GDNF 발현에 미치는 영향)

  • Sim, Ki Cheol;Kim, Gi Do;Kim, Kyung Yoon;Chung, Hun Woo;Kim, Gye Yeop
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.26 no.6
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    • pp.894-901
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    • 2012
  • The effect of Sopung-tang(SPT) and trans-cranial direct current stimulation(tDCS) was investigated in photothrombotic brain infarction(PTI) rats. Sprague-Dawley 80 rats, were divided into four groups. group I was experiental control group(n=20), group II was PTI induced and oral administration of SPT(n=20), group III was PTI induced and tDCS administration(n=20) and group IV was PTI induced and SPT and tDCS administration for 28 days on stroke rats(n=20). Analysis the neurological function test, 25 point behavior functional score test, and immunohistochemistric finding of GDNF expression, and electron microscopy assessment In motor behavior test, the outcome of group IV was significantly difference than the other group, and In immunohistochemistric finding, group II, III, IV were increase GDNF expression on 28 days, In electron microscopy finding, the all groups were degenerated of cell organelles, and synaptic plasticity were improvement of group II, III, IV(especially group IV) These results suggest that, 28days application of SPT and tDCS was the motor function and histopathologic, micro-morphological improvement of motor function recovery and positive influence on synaptic plasticity.

A QUANTITATIVE ANALYSIS OF THE IMMUNOCOMPETENT CELLS IN PERIAPICAL LESIONS OF THE HUMAN TEETH (치근단 병소에서 면역적격세포의 분포에 관한 연구)

  • Yoon, Tai-Cheol;Kim, Jin;Park, Dong-Soo
    • Restorative Dentistry and Endodontics
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    • v.17 no.1
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    • pp.55-68
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    • 1992
  • Periapical lesions are developed as a result of inflammatory response to irritants from root canal system. Clinicians remove these irritants from root canal system and seal the root canal space to induce healing of the periapical lesions. Immunopathologic responses may play an important role in development and progression of periapical lesions and periapical lesions contain immunocompetent cells. The purposes of the present study were to analys and to compare the distribution of the immunocompetent cells in the human periapical lesions according to the stage of endodontic treatment using indirect immunoperoxdase technique. Obtained 94 human periapical lesions were devided into four groups: Group 1 : no endodontic treatment(28 samples) Group 2 : root canal enlarged and irrigated(28 samples) Group 3 : root canal filled(29 samples) Group 4: unknown(9 samples) Monoclonal antibodies to examine target cells were UCHL-1 for T lymphocytes(1 : 200, Dakopatt, Denmark), L26 for B lymphocytes(1 : 200, Dakopatt, Denmark), OPD4 for helper T lymphocytes(l : 200, Dakopatt, Denmark) and alpha-1-antichymotrypsin for macrophages(l : 2000, Dakopatt, Denmark). The following results were obtained : 1. All the periapical lesions studied were infiltrated by T lymphocytes, plasma cells, B lymphocytes, and macrophages. T lymphocytes were more infiltrated than B lymphocytes, and B lymphocytes and macrophages were less infiltrated than T lymphocytes and plasma cells(P<0.05 : Oneway ANOVA test). 2. In untreated group and canal irrigated and enlarged group of all the periapical lesions, helper T lymphocytes were predominently infiltrated(P>0.05 : Oneway ANOVA test). 3. In canal filled groups of all lesions except periapical cyst, plasma cells were predominently infiltrated. But, in canal filled group of periapical cyst, helper T lymphocytes were the predominent cells(P>0.05 : Oneway ANOVA test). The above results shows that the immunologic responses play important role in pathogenesis of periapical lesions and the immunologic response involved undergoes certain changes after endodontic therapy.

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Estimation of Flow Uniformity in Water Tunnel by Using CFD Analysis (전산유동 해석을 이용한 수동의 유동 균질성 평가)

  • Lim, Y.T.;Chang, J.W.;Kim, M.S.
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.12 no.3
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    • pp.13-24
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    • 2004
  • It is easier to view flow visualization by using a water tunnel rather than a smoke wind tunnel because of low speed at same Reynolds number. Using a water tunnel also produces more definite flow visualization by the use of various color dyes. The flow uniformity in test section is very significant for accuracy of the test because most flow experiments elicit results through the installation of a model in uniform flow. The purpose of small-size desktop-type water tunnel is not to produce quantitative measurements, but rather to give a visualization of the fluid flow phenomenon. However, uniformity in the test section affects the accuracy of the results. Accordingly, this research estimates uniformity in a water tunnel test section by using the commercially available CFD code FLUENT. Results of the CFD analysis show that the flow uniformity of the test section is good.

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An Analysis of the Effect of Self-foot Reflexology on Level of Hypertension (자가발반사 자극요법이 고혈압에 미치는 효과분석)

  • Wang, Myung-Ja;Cha, Nam-Hyun
    • Research in Community and Public Health Nursing
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    • v.14 no.1
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    • pp.5-15
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    • 2003
  • Purpose: This study was to analysis the effect of self-foot reflexology(SRM) program on, level of hypertension. Method: A nonequivalent control group pretest-posttest design was used. For the experimental group, SRM was applied three times a week for 8wks. Test was done by measured x2-test, t-test, repeated measures ANOVA test. Result: There were significant decreases in systolic, diastolic blood pressure and difference of pretest and post test and between the experimental group and control group. Conclusion: Findings indicate that this study will contribute to develop nursing strategies for the regulation of the blood pressure.

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Comparative Statistic Module (CSM) for Significant Gene Selection

  • Kim, Young-Jin;Kim, Hyo-Mi;Kim, Sang-Bae;Park, Chan;Kimm, Kuchan;Koh, InSong
    • Genomics & Informatics
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    • v.2 no.4
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    • pp.180-183
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    • 2004
  • Comparative Statistic Module(CSM) provides more reliable list of significant genes to genomics researchers by offering the commonly selected genes and a method of choice by calculating the rank of each statistical test based on the average ranking of common genes across the five statistical methods, i.e. t-test, Kruskal-Wallis (Wilcoxon signed rank) test, SAM, two sample multiple test, and Empirical Bayesian test. This statistical analysis module is implemented in Perl, and R languages.

Benefit of Using Early Contrast-Enhanced 2D T2-Weighted Fluid-Attenuated Inversion Recovery Image to Detect Leptomeningeal Metastasis in Lung-Cancer Staging

  • Kim, Han Joon;Lee, Jungbin;Lee, A Leum;Lee, Jae-Wook;Kim, Chan-Kyu;Kim, Jung Youn;Park, Sung-Tae;Chang, Kee-Hyun
    • Investigative Magnetic Resonance Imaging
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    • v.26 no.1
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    • pp.32-42
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    • 2022
  • Purpose: To evaluate the clinical benefit of 2D contrast-enhanced T2 fluid-attenuated inversion recovery (CE-T2 FLAIR) image for detecting leptomeningeal metastasis (LM) in the brain metastasis work-up for lung cancer. Materials and Methods: From June 2017 to July 2019, we collected all consecutive patients with lung cancer who underwent brain magnetic resonance image (MRI), including contrast-enhanced 3D fast spin echo T1 black-blood image (CE-T1WI) and CE-T2 FLAIR; we recruited clinico-radiologically suspected LM cases. Two independent readers analyzed the images for LM in three sessions: CE-T1WI, CE-T2 FLAIR, and their combination. Results: We recruited 526 patients with suspected lung cancer who underwent brain MRI; of these, we excluded 77 (insufficient image protocol, unclear pathology, different contrast media, poor image quality). Of the 449 patients, 34 were clinico-radiologically suspected to have LM; among them, 23 were diagnosed with true LM. The calculated detection performance of CE-T1WI, CE-T2 FLAIR, and combined analysis obtained from the 34 suspected LM were highest in the combined analysis (AUC: 0.80, 0.82, and 0.89, respectively). The inter-observer agreement was also the highest in the combined analysis (0.68, 0.72, and 0.86, respectively). In quantitative analyses, CNR of CE-T2 FLAIR was significantly higher than that of CE-T1WI (Wilcoxon signed rank test, P < 0.05). Conclusion: Adding CE-T2 FLAIR might provide better detection for LM in the brain-metastasis screening for lung cancer.

The Effects of Long term Osteoporosis Management Education on BMD Level and Medication Compliance in Postmenopausal Women (장기간 골다공증관리교육이 골밀도와 약물순응도에 미치는 효과)

  • Kim, Dong-Hee;Bae, Young-Sil;Lee, Sang-Hwa
    • Journal of Korean Public Health Nursing
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    • v.28 no.1
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    • pp.102-113
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    • 2014
  • Purpose: The purpose of this study was to evaluate the effects of long term osteoporosis management education consist of exercise, drug therapy, and nutrition on bone mineral density (BMD) and medication compliance among postmenopausal women who have just been diagnosed with osteoporosis. Methods: The research design consisted of a pre-and post-test quasi-experimental design through a nonequivalent control group. The participants in this study were 60 individuals with osteoporosis, and who were classified according to two groups; the control group (n=30) who were given general clinical guidelines, and the experimental group (n=30) who received management education once for 60 minutes every three months using a standardized educational sheet. After one year, BMD was assessed using band dual energy X-ray absorptiometry (DXA) and medication possession ratio (MPR) for medication compliance. Analysis of collected data was performed using descriptive statistics t-test, chi-test, and paired t-test. Results: No significant difference in BMD (t=-1.02, p=.311) and MPR (t=-0.77, p=.440) was observed between the two groups. However, a significant increase in femur neck BMD was observed in the experimental group compared with the control group (t=-2.18, p=.033). Conclusion: Conduct of further study will be needed for examination of the effect of long-term osteoporosis management education on BMD Level and Medication Compliance in Postmenopausal Women.