• Title/Summary/Keyword: Two-sample T-test

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Storage stability of reduced sulfur gases in Tedlar bag sampler: Test of two different storing approaches (Tedlar-bag 시료채집법을 이용한 황화합물의 경시적 농도 변화특성: 시료의 생성방식의 차이에 따른 비교연구)

  • Jo, Hyo-Jae;Kim, Ki-Hyun
    • Analytical Science and Technology
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    • v.24 no.3
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    • pp.212-218
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    • 2011
  • In this study, temporal stability of 5 reduced sulfur compounds (RSCs) including ($H_2S$, $CH_3SH$, DMS, $CS_2$, and DMDS) was investigated up to 30 days. To learn the temporal changes in RSC concentration levels, two types of long-term storage experiment were carried out by employing two different approaches for sample storing in Tedlar bag samplers. The first one named as a forward (F) storage method consists of preparing all samples in the beginning of experiment. All these samples were analyzed sequentially through time. The second approach named as a reversed (R) storage method was carried out by preparing each sample through time and by analyzing all of them in the last day. For these experiments, RSC standards were prepared at 10 ppb in 10 L Tedlar bag. The results of both methods were consistent enough to show a tendency of the concentration reduction through time. Moreover, the lightest RSC, $H_2S$ showed the most significant reduction of 84.8% at the end of experiment. To validate difference between these results, t-test was applied to the data obtained between the two methods at 90% significance level. According to t-test, the results of the two approaches were greatly distinguished from 3 RSCs ($H_2S$, $CH_3SH$, and DMDS). The results also indicated that the temporal reduction of RSC differs greatly between light ($H_2S$ and $CH_3SH$) and heavy RSCs (DMS, DMDS, and $CS_2$). The former generally exhibited much significant reduction through time due probably to their lower stability.

Changes in Stress Hormone, Lymphocytes, and Neutrophils Related to Examination and Social Support in University Students (시험과 사회적 지지에 따른 대학생의 스트레스 호르몬, 림프구 및 호중구의 변화)

  • Kim, Joo-Hyun;Chae, Young-Ran
    • Korean Journal of Adult Nursing
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    • v.22 no.1
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    • pp.11-18
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    • 2010
  • Purpose: The purpose of the study was to identify levels of anxiety, stress hormone, lymphocytes, and neutrophils of the nursing students before an examination and to examine effects of social support on those variables related to taking examinations. Methods: Thirty eight healthy nursing students participated. They completed the questionnaire including state anxiety, test anxiety (VAS scale) and social support two weeks before the exam and again just before the exam. Simultaneously, a venous sample for ACTH, cortisol, lymphocytes & neutrophils count was drawn by a trained nurse. Descriptive statistics, paired t-test, student t-test, and Pearson's correlation with SPSS/WIN 14.0 were used to analyze the data. Results: Test anxiety scores and cortisol level on the exam day showed a significant increment compared with those on the non-exam day. The participants with higher levels of total social support scores showed significantly lower state anxiety on the exam day than those with lower levels of total social support scores. Conclusion: These data indicate a possible alteration in cortisol responsiveness to academic stress in nursing students. Social support would play an important role in modulation of academic stress.

Bayesian Estimations for the Two-parameter Exponential Model under the Type-II Censoring (제2종(第2種) 중단(中斷) 자료(資料)에서 두 모수지수분포(母數指數分布)의 베이지안 추정(推定))

  • Kim, Heon-Joo;Youn, Young-Hwa;Ko, Jeong-Hwan
    • Journal of the Korean Data and Information Science Society
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    • v.4
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    • pp.65-74
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    • 1993
  • Suppose that we have two populations(or systems), say ${\Pi}_{1}\;and\;{\Pi}_{2}$, to be tested. A random sample of size n from each population is taken and the test for each system will be terminated when the first r failures among n random samples are observed. This kind of test is caned the type-II censored (or item-censored) testing without replacement. Under this scheme we consider the problem of estimating the unknown parameters of interests and the reliability for a given time t for each population.

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A Study on Mechanical Properties Changes to Improve the Confidence of Remaining Life Evaluation for the Weldment of Power Plant Boiler Tube(SA213-T12) (발전설비 보일러 튜브 용접부의 잔여수명평가 신뢰성 향상을 위한 기계적 물성 변화 연구(SA213-T12))

  • Oh, Byungjin;Jang, Joong Soon
    • Journal of Welding and Joining
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    • v.32 no.3
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    • pp.102-107
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    • 2014
  • Boiler equipment in power plant is always being operated in harsh conditions and severely exposed to the extreme environment of high temperature. Therefore periodically the state of devices should be checked, diagnosed, and analyzed to ensure the reliability of the equipment. Traditionally, such a diagnosis is based one or two physical properties of the sample taken from the equipment like hardness, microstructure, etc.. However, to enhance the confidence of the diagnosis, it is necessary to synthesize those properties together. This paper is to propose such a synthetic procedure for SA213-T12(1Cr-0.5Mo) which was developed to be used in $565^{\circ}C$ below condition. Creep test and accelerated degradation test were performed simultaneously, and the physical properties such as microstructure, tensile strength, yield strength, hardness, and indentation properties were measured. This paper proposes a method of determining the remaining life by quantitative comparison. It will provide the basis of evaluating life assessment more objective and reliable.

Psychological Treatment for Pain Among Cancer Patients by Rational-Emotive Behavior Therapy - Efficacy in both India and Iran

  • Mahigir, Foroogh;Khanehkeshi, Ali;Karimi, Ayatollah
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.9
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    • pp.4561-4565
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    • 2012
  • The aim of the present study is to find out the influence of rational-emotive behavior therapy (REBT) on pain intensity among cancer patients in India and Iran. The study followed a quasi-experimental, pre-post test, carried out with a sample of 88 cancer patients, aged 21-52 years, referred to the Baharat cancer hospital of Mysore in India and Shahidzade hospital of Behbahan in Iran. They were randomly assigned to the experimental (n=India 21; Iran 22) and control (n=India 22; Iran 23) groups. Pain was measured with the McGill Pain Questionnaire-MPQ (1975), the intervention by REBT has given to the experimental group for 45 days (ten sessions) and at the end of intervention, the pain of patients was again evaluated. Concerning to hypothesis of the study, two independent sample T test and three ways mixed ANOVA is used to analyze the data. Results showed that the experimental group in post test had less pain than the control group, but there were no statistically significant differences between Indian and Iranian patients in pain perception. With respect the outcome of study, it has realized that REBT can be used in hospitals and other psychological clinics to reduce the pain of cancer patients.

Effect of Yikgeebohyul-tang (Yiqib$\check{u}$xu$\grave{e}$-tang) on Hair Regrowth and Cytokine Changes on Hair-Removed C57BL/6 Mice (익기보혈탕(益氣補血湯)이 C57BL/6 마우스의 육모(育毛)촉진 및 Cytokine 변화에 미치는 영향)

  • Hong, Jung-Ae;Song, Mi-Yeon;Choi, In-Hwa;Sohn, Nak-Won;Chung, Seok-Hee
    • The Journal of Korean Medicine
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    • v.31 no.1
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    • pp.138-152
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    • 2010
  • Objective: Yikgeebohyul-tang (Yiqib$\check{u}$xu$\grave{e}$-t$\bar{a}$ng) is one of the representative prescriptions for invigoration of vitality and nourishing of the blood. This study was carried out to investigate the effects of Yikgeebohyul-tang (Yiqib$\check{u}$xu$\grave{e}$-t$\bar{a}$ng) on hair regrowth and cytokine changes in a shaving model of C57BL6 mice. Method: Five-week-old mice were acclimated for 1 week at a temperature between $21-23^{\circ}C{\acute{E}}$, 40-60% relative humidity, and 12h of a light/dark cycle before beginning of the experiment. There were two groups including normal saline (control) and a positive control of oral intake of Yikgeebohyul-tang (Yiqib$\check{u}$xu$\grave{e}$-t$\bar{a}$ng) extract (sample) in 18 female mice. The test compounds were topically treated once a day over 14 days. The hair regrowth was photographically and histologically determined during the experimental period of 14 days. Revelation of TGF-${\beta}1$ and EGF were also determined using immunohistochemistry. In addition to that, IFN-$\gamma$, IL-4 and IL-10 were determined in serum. Results: Hair regrowth in the sample group was promoted earlier and faster than the control group, as shown by concentrations of hairs and thick-hair ratio in the sample group. TGF-${\beta}1$ was not revealed in either control or sample group. EGF was strongly positive in out root sheath of some thick hair of the sample group. Serum IFN-$\gamma$ was significantly decreased in the sample group compared with the control group at 7 experimental days. However, it was not significantly decreased at 14 experimental days. Serum IL-4 was significantly increased in the sample group compared with the control group at 7 experimental days. However, it was not significantly decreased at 14 experimental days. Serum IL-10 was decreased in the sample group compared with the control group, but with no real statistical significance. Conclusion: These results suggest that Yikgeebohyul-tang (Yiqib$\check{u}$xu$\grave{e}$-t$\bar{a}$ng) has hair growth promoting activity and it can be used for treatment of alopecia. Also, these effects relate to EGF revelation of hair roots, a decrease in serum IFN-$\gamma$, and an increase of serum IL-4.

A descriptive survey study of stress, depression, fatigue & sleep quality in gestational diabetes mellitus and normal pregnancy (임신성 당뇨병 임부와 정상 임부의 스트레스, 우울, 피로 및 수면의 질에 관한 서술적 조사연구)

  • Hwang, In-Myung;Hur, Myung-Haeng
    • Journal of the Korea Convergence Society
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    • v.12 no.8
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    • pp.369-379
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    • 2021
  • This study was a descriptive survey study to compare the stress, depression, fatigue, and sleep quality between pregnant women with gestational diabetes mellitus (GDM) and normal pregnant women. The study subjects were 49 gestational diabetes mellitus women and 51 normal pregnant women who were matching with gestational diabetes mellitus women by age, gestational age and number of births. The data collection was measured using structured questionnaires, numerical scales, and Canopy9 RSA(IEMBIO, Gangwondo, Korea) equipment. As a result of the study, pregnant women with gestational diabetes had higher pre-pregnancy weight(t=3.698, p<.001) and higher stress(t=4.505, p<.001), depression(t=4.564, p<.001), and fatigue(t=3.709, p<.001) during pregnancy, so weight management is important before pregnancy, and stress, fatigue, and depression relief nursing

Efficacy of local hyaluronidase administration in guided bone regeneration surgery: a randomized controlled trial

  • Kwoen, Min-Jeong;Choi, Yong-Hoon;Kim, Keun-Suh;Chang, Na-Hee;Kim, Young-Kyun;Lee, Hyo-Jung
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.47 no.2
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    • pp.91-98
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    • 2021
  • Objectives: Hyaluronoglucosaminidase (hyaluronidase) increases the local intercellular permeability of the peripheral lymphatic channel and capillaries, which may help reduce edema. In the present study, the effects of hyaluronidase on postoperative edema and pain reduction were evaluated. Materials and Methods: The study included 38 patients who underwent guided bone regeneration (GBR) surgery before implantation. Patients were randomly assigned to either the control group (n=20) or the test group (n=18). Hyaluronidase was injected into the GBR site of subjects in the test group. Postoperative edema was evaluated by measuring the distance between specific facial landmarks immediately after surgery (T1) and 2-4 days after surgery (T2). The degree of pain at T2 and at 10-14 days after surgery (T3) was assessed. Results: In the test group, the degree of swelling was lower than in the control group, however, only two measurements, from the tragus to the mouth corner and from the outer canthus to the mouth corner, showed statistically significant differences (P=0.012 and P=0.001, respectively). The anti-edema effect of hyaluronidase was more effective in the maxilla than in the mandible. In the maxilla, the percentage of facial swelling was significant for three measurements. However, in the mandible, the percentage of facial swelling was significant for only one measurement. Low levels of pain that were similar at T2 and T3 were reported in both groups. Conclusion: The results indicate the degree of swelling was lower in the test group and hyaluronidase appeared to be more effective in the maxilla. The degree of pain reduction was similar between groups. Further in vivo and randomized controlled trials with larger sample sizes are warranted.

Determining the Knowledge of Women and Their Attitudes Regarding Gynecological Cancer Prevention

  • Bekar, Mine;Guler, Handan;Evcili, Funda;Demirel, Gulbahtiyar;Duran, Ozlem
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.10
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    • pp.6055-6059
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    • 2013
  • The current study determines the knowledge of female course attendees of the "Municipality Cultural Center for Women", located in the city center of Sivas, Turkey, and their attitudes regarding gynecological cancer prevention. The participants of the study include 497 women attending one of the two Municipality Cultural Centers situated in the city center of Sivas. In this study, the sample was not selected; all participants were encompassed within the scope of our research. A total of 418 female course attendees who volunteered to participate in the research were identified as the sample. The data were collected during the months March-June 2011, by a questionnaire developed by the researchers. To compare the distribution of the collected data "Anova", "two independent t test examples" and "chi square test" were used. The research indicates that 45.1% of the women had had gynecological examination as a consequence of a physical disorder. The reason for 54.9% of the women to have gynecological examination is to have been scanned to check for gynecological cancer, 51.2% had a pap smear test. Some 34.9% of them had obtained information about cervical cancer, 39.7% via radio, television or internet and 36.3% from a doctor. Age, education level and marital status of the women participating in this study demonstrated statistically significant correlations (p<0.05) with gynecological examination and undergoing a pap smear test.

Effective Test and Evaluation Approaches for Reliable Defense Systems Development examined through Domestic Defense Cases (국내 사례로 살펴보는 국방체계 개발의 신뢰성을 높이기 위한 시험평가 방안)

  • Seo, Kyung-Min;Lee, Chan Young;Bang, Kyoung Woon;Lee, Dong Chul;Choi, Woo Young;Kim, Tag Gon
    • Journal of the Society of Naval Architects of Korea
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    • v.53 no.2
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    • pp.127-134
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    • 2016
  • This paper presents practical issues for test and evaluation(T&E) methods to develop defense systems. Our argument is motivated by several domestic defense cases and the cases lead us to discuss two main factors for reliable defense systems development: 1) statistical approaches and 2) technical schemes. Specifically, statistical approaches enable to provide credible interpretations about T&E results in the decision-making process. With practical T&E results of the “Red Shark” torpedo, we performed statistical hypothesis tests and suggest a minimum sample size to accept the hypothesis. Next, technical schemes have more direct effects on improving reliability of developed defense systems and we shortly introduce tools development for systems verification that is required to integrate several sub-systems, e.g., combat, sensor, weapon, and communication systems, within a defense system. We additionally summary some domain cases using modeling and simulation techniques for successful T&E. In closing, we expect that the paper shows empirical investigation and lessons learned with these two practical issues, which provides a guide those who desire to make decisions about reliable defense systems development.