• Title/Summary/Keyword: T-test analysis

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A comparative analysis of volatile organic compound levels in field samples between different gas chromatographic approaches (분석기법의 차이에 따른 현장시료의 VOC 분석결과 비교연구: 분석오차의 발생 양상과 원인)

  • Ahn, Ji-Won;Pandey, Sudhir Kumar;Kim, Ki-Hyun
    • Analytical Science and Technology
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    • v.23 no.5
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    • pp.465-476
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    • 2010
  • In this study, a number of volatile organic compounds (VOCs) including benzene, toluene, p-xylene, styrene, and methyl ethyl ketone were analyzed from samples collected in ambient air and under the field conditions. These samples were analyzed independently by two different set-ups for VOC analyses, i.e., between [1] gas chromatography/flame ionization detector with tube sampling - (F-T system) and [2] gas chromatography/mass spectrometer with bag sampling (M-B system). The analytical results derived by both systems showed fairly similar patterns in relative sense but with moderately large differences in absolute sense. The results of M-B system were high relative to F-T system with the F-T/M-B ratio below 1. If the relative biases of the two measurement techniques are derived in terms of percent difference (PD) in concentration values, the results were generally above 35% on average. A student t-test was applied to investigate the statistical significance of those differences between the systems. The results of both analytical systems were different at 95% confidence level for toluene, p-xylene, styrene, and methyl ethyl ketone (P < 0.043). However, F-T and M-B systems showed strong correlations for toluene and p-xylene. The observed bias is explained in large part by such factors as the differences in standard phases used for each system and the chemical loss inside the bag sampler.

Development and Application of Water Quality Level Model (WQLM) for the Small Streams of Rural Watersheds with Discriminant Analysis (판별분석을 통한 농촌유역 소하천의 수질등급모형(WQLM) 개발 및 적용)

  • Kim, Jin-Ho;Choi, Chul-Mann;Ryu, Jong-Soo;Jung, Goo-Bok;Shin, Joung-Du;Han, Kuk-Heon;Lee, Jung-Taek;Kwun, Soon-Kuk
    • Journal of Korean Society on Water Environment
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    • v.23 no.2
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    • pp.260-265
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    • 2007
  • This study was carried out to complement water quality standards and to establish new concept for water quality standards reflecting current state of water quality in small streams. By this purpose, discriminant analysis was performed and Water Quality Level Model (WQLM) was developed using the data such as EC, BOD, $COD_{Mn}$, SS, T-N, T-P, $NH_3-N$ in 224 agricultural streams. To give water quality level for water quality parameters, it divided into 20% respectively in the order of excellent water quality. On the basis of the lowest water quality level, water quality level of small streams is granted. As a result of it, number of stream corresponding to Level I was no, Level II was 2 streams, Level III was 22 streams, Level IV was 70 streams, and Level V was 130 streams. Average of water quality in each level was the highest in Level V. EC, SS, and T-N of 7 parameters were selected in variance concerned water quality level. By standardized canonical discriminant function coefficient, EC of three variances was the highest in 0.625 at the discriminant power. The next was T-N (0.509), SS (0.414). By discriminant function for water quality level, Level II was equal to $-2.973+19.376{\times}(EC)+0.647{\times}(T-N)+0.009{\times}(SS)$, Level III was equal to $-3.288+19.190{\times}(EC)+0.733{\times}(T-N)+0.041{\times}(SS)$, Level IV was equal to $-4.462+27.097{\times}(EC)+0.792{\times}(T-N)+0.053{\times}(SS)$, and Level V was equal to $-9.117+40.040{\times}(EC)+1.305{\times}(T-N)+0.111{\times}(SS)$. As a result of test at real agricultural watershed of Jeongan and Euidang in Gongju city, the fitness of WQLM was high to 88.78%. But, to get accomplished water quality assessment more exactly in agricultural streams, we had to concentrate and get vast data, and WQLM was modified and complemented continually.

Report on the Effects Lipemic Specimen in Anti-ds DNA Antibody Test (Anti-ds DNA 항체 검사 시 Lipemic 검체의 영향에 관한 보고)

  • Cheon, Jun Hong;Kim, Whe Jung;Kim, Sung Ho;Moon, Hyoung Ho;Yoo, Seon Hee
    • The Korean Journal of Nuclear Medicine Technology
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    • v.18 no.1
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    • pp.153-157
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    • 2014
  • Purpose: SLE (systemic lupus erythematosus) is an inflammatory autoimmune disease, characterized by various autoantibody. The detection of Anti double-stranded DNA (Anti-ds DNA) is important in the diagnostics of SLE, and include the American College of Rheumatology (ACR) diagnostic criteria for SLE. Also SLE disease activity and correlativity with the level Anti-ds DNA antibody have been reported and Anti-ds DNA antibody quantitative test is very useful for tracing before and after SLE treatment. When These Anti-ds DNA antibody test (Farr assay: $^{125}I$ labeled ds-DNA and bound Anti-ds DNA antibodies complex in serum is precipitated by ammonium sulfate and used to centrifugation, measured it) inhaled supernatant after centrifugation, a lipemic specimen does not facilitate the formation of precipitate and also occurs situation was inhaled with precipitate. To solve these problems, The Influence of the degree of lipemic specimen was evaluated. Materials and Methods: September 2012 to February 2013, We selected lipemic samples (n=81) of specimen commissioned by Anti-ds DNA antibody test. Lipemic samples were done pre-treatment (high-speed centrifugation: 14,000 rpm 5 mins) used a micro-centrifuge (Eppendorf Model 5415D). At the same time lipemic specimen and pre-treatment samples were performed Anti-ds DNA antibody test (Anti-ds DNA kit, Trinity Biotech, Ireland). Statistical analysis were analyzed Pearson's correlation coefficients and regression and paired t-test, and Difference (%). Results: Experimental group 1 (Lipemic Specimen Anti-ds DNA Ab concentration ${\leq}7IU/mL$) at y=0.368X+4.732, $R^2=0.023$, Pearson's correlation coefficient was 0.154, paired t-test (P=0.003), Difference (%) mean 65.7 and showed a statistically significant difference. Experimental group 2 (Lipemic Specimen Anti-ds DNA Ab concentration ${\geq}8IU/mL$) at y=0.983X+0.298, $R^2=0.994$, Pearson's correlation coefficient showed 0.997, paired t-test (P=0.181), Difference (%) mean -5.53 made no statistically significant difference. Conclusion: Lipemic sample of low Anti-ds DNA Ab concentration (2.5-7 IU/mL) and the result is obtained pre-treatment (high-speed centrifugation: 14,000 rpm 5 mins) were made a significant difference statistically. Anti-ds DNA is one of the primary auto-antibodies present in patients with SLE, and remain an important diagnostic test for SLE. Therefore, we recommend preprocessing (high-speed centrifugation: 14,000 rpm 5 mins) in order to exclude the influence of lipemic specimen.

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Effect of Stroke Health Education on Knowledge of Stroke for Rural Elders (일 지역 농촌 노인의 뇌졸중 교육이 뇌졸중 지식정도에 미치는 효과)

  • Kim, Eun-Mi;Hong, Ji-Yeon
    • Journal of Korean Academy of Rural Health Nursing
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    • v.4 no.2
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    • pp.103-109
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    • 2009
  • Purpose: This study was conducted to test the effect of a 5 weeks health education program on stroke for rural elderly people. Methods: A total of 55 rural elders in Kok Sung County were participated in the health education on stroke program. Descriptive statistics, and paired t-test were used for statistical analysis with SPSS 12.0. Results: The results are summarized as follows : Mean age was 67.3 years and 88.2% of participants were female. The mean pre-test scores for knowledge of stroke were 0.35 and post-test, 0.85 (p< .001). Percentage of accurate response rates of warning signs of stroke were sudden dizziness pre-test 45.5% post-test 80.0%, sudden trouble speaking or understanding, pre-test 27.3% post-test 41.8%, sudden trouble walking, loss of balance or coordination, pre-test 32.7% post-test 70.9%, sudden numbness or weakness of the arm or leg, especially on one side of the body, pre-test 47.3% post-test 72.7%, sudden confusion, pre-test 27.3% post-test 81.8%, sudden numbness or weakness of the face especially on one side of the body, pre-test 40.0% post-test 76.4%, sudden severe headache with no known cause, pre-test 40.0% post-test 70.9%, Sudden trouble seeing in one or both eyes, pre-test 38.1% post-test 66.0%, nausea or vomiting pre-test 16.4% post-test 43.6%. The increases after the health education on stroke were statistically significant. Conclusions: Health education on stroke for rural elderly people are needed and should focus on community health care programs, especially for those who are older, had a low level of education, and low socio-economical status.

RELATIONSHIP OF DENTAL ANXIETY BETWEEN CHILD AND PARENT DURING DENTAL VISIT (치과 방문 시 어린이와 부모의 치과 불안도의 상관 관계)

  • Kim, Sung-Hee;Kim, Jae-Gon;Yang, Yeon-Mi;Kwon, Byoung-Woo;Baik, Byeong-Ju
    • Journal of the korean academy of Pediatric Dentistry
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    • v.32 no.2
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    • pp.370-376
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    • 2005
  • In children, dental anxiety of dental treatment has been recognized as a source of problems in patient man agement for many years. Dental anxiety can be causes of negative cooperation, cancel and avoid of dental treatment. Therefore, dentist and dental team should recognize of child's dental anxiety as early as possible and manage appropriately. In previous studies, it is reported that parental dental anxiety affect dental anxiety and cooperation of their child. And it is parental decision which results in a child's visit to the dentist, rather than a child's decision in most cases. Therefore, it is important to identify the relationship of dental anxiety between child and parent. We estimated child's dental anxiety before dental treatment using Venham Picture Scale that is useful even a very young child and parental dental anxiety using Corah's dental anxiety scale. Then, two values above were compared. Child's cooperation, temperament, sex, age, parental education were estimated and compared with dental anxiety, too. The results were as follows: 1. There are positive relationship of dental anxiety between child and parent with the correlation analysis(P<0.02). 2. There are negative relationship of child's dental anxiety and child's cooperation with the correlation and regression analysis(P<0.001). 3. Low anxiety group has lower mean value of four temperament item with the Student's t-test. But, there is no statistical differences(P>0.1). 4. Girl and younger group have higher mean value of dental anxiety than boy and older group with the Student's t-test(P<0.001). 5. Low educated parents have higher mean value of dental anxiety than high educated parents with the Student's t-test(P>0.1).

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A Study on Bending Fatigue Strength of One Side Fillet Welded T-Joint by SM 490A steel (Sm 490A강으로 제작된 T형 편면용접이음재의 굽힘피로강동에 관한 연구)

  • 엄동석;강성원;이태훈;이해우;조수형
    • Journal of Welding and Joining
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    • v.16 no.5
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    • pp.134-141
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    • 1998
  • In this study, a fillet size for bending fatigue strength of one side fillet welded T-joint, used in box type girder and other welding structure, was investigated by bending fatigue test with or without edge preparation and burn through, with variation of joint shape. As a result, the following conclusions were obtained. (1) In one side fillet welded T-joint, the larger the leg length, the greater the bending fatigue strength. The increase in bending fatigue strength. (2) One side filet welded T-joint with edge preparation showed higher bending fatigue strength than that with twofold-large leg length and without edge preparation. (3) In one side fillet welded T-joint without edge preparation, both manual welding and automatic welding were carried out with same condition. In this case, automatic welding shoed deeper penetration and more increased horizontal leg length than manual welding, so that automatic welding offers grater bending fatigue strength. (4) For one side fillet welded T-joint without edge preparation, the ratio(h/t) of the leg length (h) and the main plate thickness (t) in which toe crack can occur was 1.2 over. (5) In one side fillet welded T-joint with edge preparation, the burn through led to reduced bending fatigue strength. However, this bending fatigue strength was higher than that of one side fillet welded T-joint without edge preparation and with a larger leg length.

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EFFECTS OF MACROPHAGE INFLAMMATORY $PROTEIN-1{\alpha}$ON THE T CELL PROLIFERATION AND THE EXPRESSION OF CD4 AND CD8 (Macrophage Inflammatory Protein $1{\alpha}$가 T세포성장 및 CD4, CD8 발현에 미치는 영향)

  • Choi, Jong-Sun;Kim, Oh-Whan
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.18 no.1
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    • pp.153-163
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    • 1996
  • Macrophage inflammatory protein $(MIP)-1{\alpha}$ is a cytokine which produces wide range of bioactivities such as proinflammatory, immunomodulatory, and hematopoietic modulatory actions. To determine whether $MIP-1{\alpha}$ acts as a negative regulator on the functions of lymphocyte, $[^3H]$-thymidine incorporation test and flow cytometric analysis were performed by using human tonsil T cell, human peripheral blood T cell, and murine cytolytic T lymphocyte (CTL) line CTLL-2, The results were as follow. 1. When human tonsil T lymphocytes were stimulated with anti-CD3 monoclonal antibody (mAb), rate of T cell proliferation was about four times increased. 200ng/ml of $MIP-1{\alpha}$ inhibited anti-CD3 mAb-mediated T cell growth as much as 60% (P<0.05). 2. The suppression of human peripheral T cell proliferation produced by $MIP-1{\alpha}$ was dramatic, but variable among T cells derived from different individuals $(40%{\sim}90%)$. 3. $MIP-1{\alpha}$inhibited the proliferation of murine CTL line CTLL-2 as much as 75%(P<0.001). 4. When the $MIP-1{\alpha}$ was added to human peripheral T cell, cell proporation of $CD4^+$ helper T cell and $CD8^+$ CTL were not noticeably affected. The expression level of CD4, not of Cd8, however, was down regulated by $MIP-1{\alpha}$ treatment $(27%{\sim}82%)$.

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Relationships among Nursing Students' Recognition, Perceived Usefulness, and Intention to Accept IoT

  • KANG, Ji-Yeon;KONG, Ye-Won;KIM, Eun-Bi;KIM, Eun-Ae;PARK, Sun-Joo;PARK, Jina;SEONG, Ji-Yeon;SON, Chae-Eun;LEE, Bo-Mi;KIM, Yunmi
    • The Korean Journal of Food & Health Convergence
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    • v.7 no.1
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    • pp.1-5
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    • 2021
  • The purpose of this study was to investigate the degree of recognition, perceived usefulness, and intention to accept the Internet of Things (IoT) in healthcare among nursing students, as well as to determine related factors. Through this study, we wanted to develop the basic research for the education related to the IoT in healthcare. In this study, data were collected from 348 nursing students using self-report online questionnaires, Naverform, and analyzed using the independent sample t-test, one-way analysis of variance, and Pearson correlation coefficients in SPSS version 26.0. The results of the study show that recognition of the IoT was correlated with its perceived usefulness (r=0.37; p<.001) and intention to accept the IoT (r=0.23 (p<.001). The strongest correlation was found between perceived usefulness of the IoT and intention to accept (r=0.67; p<.001). In conclusion, recognition of the IoT in healthcare affected its perceived usefulness, and a significant correlation was found between perceived usefulness of the IoT and intention to accept it. This study analyzed how much recognition, perceived usefulness, and intention to accept IoT in healthcare nursing students have. Based on these findings, we suggest that education related to the IoT in healthcare should be incorporated into the nursing curriculum.

A study on purchase and use management of small electric appliances in the urban household. -Mainly Automatic Rice Cooker, Electric Frypan, Toaster and Blender- (도시가정의 소형 전기기구의 구매와 사용관리에 관한 연구 -전기밥솥, 전기 프라이팬, 토우스터, 블렌더를 중심으로-)

  • 이정우
    • Journal of the Korean Home Economics Association
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    • v.24 no.2
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    • pp.93-112
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    • 1986
  • The purpose of this study is to clarify which some factors among the socio-demographic factors have effect on the housewives behavior on how to buy small electric appliances and how to use them. The questionnaires were distributed in July 1985 to 491 housewives in Seoul. Satistical methods as percentage, frequency, arithmetic mean, chi-square test, t-test and F-test were used for data analysis. RESULTS : 1) The average rate of possessing the automatic rice cooker is 87.8%, the electric frypan is 81.0%, the toaster is 36.9% and the blender is 86.9%. 2. Generally the frequency of use were low. 3) Generally their knowledge on small electric appliances is low. 4) The ability of management in blender was influenced by age, education and in automatic rice cooker was influenced by only education.

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Characteristic Tests for 800kV Class Spacer (800kV급 스페이서의 특성시험)

  • Chong, J.K.;Song, K.D.;Chang, K.C.;Park, K.Y.;Shin, T.J.
    • Proceedings of the KIEE Conference
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    • 1996.07a
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    • pp.65-67
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    • 1996
  • The spacer is solid insulator which supports main conductor in GIS and seperates gas area. The 800kV spacer was designed and manufactured considering the results of electrical and structural analysis using commercial package MSC/NASTRAN. Temperature test and water pressure test were carries out, and the results from water pressure test were compared with the calculated ones from MSC/NSATRAN.

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