• Title/Summary/Keyword: Correlation Coefficient($\gamma$)

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Measurement of Shunt Amount Using Radionuclide Angiocardiography: Accuracy According to Level of Shunt and Associated Lesion (방사성 동위원소 심혈관 조영술을 이용한 단락량 측정법: 정확성에 영향을 미치는 인자)

  • Kim, Yang-Min
    • Nuclear Medicine and Molecular Imaging
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    • v.40 no.4
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    • pp.200-204
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    • 2006
  • Purpose: Determination of pulmonary to systemic blood flow ratio (QP/QS) is important for the management of patients with left-to-right shunt. This study was performed to assess the agreement of Qp/Qs ratio using the radionuclide method and oxymetry, to investigate the factors influencing the agreement, and to know how interchangeable the results of each technique. Materials and Methods: We compared the Qp/Qs measured by single-pass radionuclide angiocardiography and oxymetry during catheterization in 207 patients who underwent both studies. In radionuclide method, Qp/Qs was calculated from the pulmonary time-activity curves using a gamma variate fit. The correlation and Bland-Altman analysis were performed according to the levels of shunt and associated lesions. Results: The mean Qp/Qs was $1.83{\pm}0.50$ by radionuclide, and $1.74{\pm}0.51$ by oxymetry. The overall correlation coefficient was 0.86(p<0.001), and Bland-Altman range of agreement encompassing 4SD was 1.05. For atrial septal defect, ventricular septal defect, patent ductus arteriosus, tricuspid and mitral insufficiency, the correlation coefficient was 0.78, 0.90, 0.84, 0.63 and 0.44, and Bland-Altman range was 1.51, 0.74, 0.96, 1.57, and 1.50, respectively. Conclusion: There is good agreement but wide variance between the Qp/Qs ratios by radionuclide method and oxymetry. Associated atrioventricular valvar insufficiency decreases the correlation coefficient and widens the variance. Wide overall variance suggests that Qp/Qs measurements by two techniques should not be used interchangeably.

Seasonal Variation of Eubacterial Community Structure and Their Structure Affecting Environmental Parameters in Reservoir (남매지에서 Eubacteria 군집구조의 계절적 변화와 그에 영향을 미치는 환경요인)

  • 이희순;박정원;김미경;이영옥
    • Korean Journal of Microbiology
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    • v.38 no.1
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    • pp.31-37
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    • 2002
  • For elucidating the correlation between the eubacterial community structure and environmental parameters in Nammae Reservoir located in Kyungsan, Kyungbuk, the bacterial community structure and their structure affecting environmental parameters were analyzed using Fluorescent In Situ Hybridization (FISH) monthly over year. $\alpha$ . $\beta$ . $\gamma$-subclasses of Proteobacteria and Cytophaga-Flavobacterium (CF) group known as dominant bacterial group in freshwater were detected in 3 stations over year. The ratio of each subclass to total bacteria was determined; $\alpha$.$\beta$ . $\gamma$-subclasses and CF group varied in the range of 4.0~29.2%, 1.7~25.8%, 1.8~12.8%, 4.9~36.3%, respectively and there was no substantial differences between stations. In terms of the correlation between each group specific bacteria and environmental parameters such as temperature, SS, pH, DOC, NH$_4$-N, NO$_3$-N, PO$_4$-P, standing crops of algae, the results were as follows: 1) total bacterial numbers correlated positively with temperature, SS and DOC, 2) Eubacteria positively with DOC and Chl-$\alpha$, 3)${\gamma}$-subclass positively with DOC, and 4) CF group positively with standing crops of chlorophyceae, 5) whereas $\beta$-subclass bacteria correlated negatively with standing crop of cyanobacteria and that of total algae.

Evaluation of Reliability about Short TAT (Turn-Around Time) of Domestic Automation Equipment (Gamma Pro) (국산 자동화 장비(Gamma Pro)의 결과보고시간 단축에 대한 유용성 평가)

  • Oh, Yun-Jeong;Kim, Ji-Young;Seok, Jae-Dong
    • The Korean Journal of Nuclear Medicine Technology
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    • v.14 no.2
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    • pp.197-202
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    • 2010
  • Purpose: Recently, many hospitals have been tried to increase the satisfaction of the outpatients through blood-gathering, exam, result notice and process in a day. Each laboratory has been used the automatic equipment for the rapid requests of the result notice and the increase of the reliability and efficiency. Current automatic equipments that have been limited short TAT(Turn-Around Time)because of the restricted batch lists and 1 tip-5 detectors. The Gamma Pro which is made in Korea to improve the shortcomings of existing automation equipment, complemented with capacity to perform a wide range of domestic automation equipment. In this study, we evaluated the usefulness and reliability of short TAT by comparing Gamma Pro with current automatic equipment. Materials and Methods: We studied the correlation between Gamma Pro and RIA-mat 280 using the respective 100 specimens of low or high density to the patients who were requested the thyroid hormone test (Total T3, TSH and Free T4) in Samsung Medical Center Sep. 2009. To evaluate the split-level Gamma Pro, First, we measured accuracy and carry over on the tips. Second, the condition of optimal incubation was measured by the RPM (Revolution Per Minute) and revolution axis diameter on the incubator. For the analysis for the speed of the specimen-processing, TAT was investigated with the results in a certain time. Result: The correlation coefficients (R2) between the Gamma Pro and RIA-mat 280 showed a good correlation as T3 (0.98), TSH (0.99), FT4 (0.92). The coefficient of variation (C.V) and accuracy was 0.38 % and 98.3 % at tip 1 and 0.39 % and 98.6 % at tip 2. Carry over showed 0.80 % and 1.04% at tip 1 and tip 2, respectively. These results indicate that tips had no effect on carry over contamination. At the incubator condition, we found that the optimal condition was 1.0mm of diameter at 600RPM in 1.0mm and 1.5mm of at 500RPM or 1.0mm and 1.5 mm of diameter at 600 RPM. the Gamma Pro showed that the number of exam times were increased as maximum 20 times/day comparing to 6 times/day by current automatic equipment. These results also led to the short TAT from 4.20 hour to 2.19 hours in whole processing. Conclusion: The correlation of between the Gamma Pro and RIA-mat 280 was good and has not carry over contamination in tips. The domestic automation equipment (Gamma Pro) decreases the TAT in whole test comparing to RIA-280. These results demonstrate that Gamma Pro has a good efficiency, reliability and practical usefulness, which may contribute to the excellent skill to process the large scale specimens.

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Variation on Fatty Acid Profile Including ${\gamma}-Linolenic$ acid among Hemp (Cannabis sativa L.) Accessions (대마 유전자원의 지방산 조성과 감마리놀렌산 함량변이)

  • Moon, Youn-Ho;Song, Yeon-Sang;Jeong, Byeong-Choon;Bang, Jin-Ki
    • Korean Journal of Medicinal Crop Science
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    • v.13 no.4
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    • pp.190-193
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    • 2005
  • Hemp is cultivated to produce fiber and seeds for extracting vegetable oil. This study was carried out to obtain reliable data on fatty acid profile including ${\gamma}-linolenic$ acid (GLA) in seeds of hemp accessions with regard to suitability for both human nutrition and pharmaceutical purposes. The ratio of unsaturated fatty acid including ${\alpha}-linolenic$ acid were high but saturated fatty acid including palmitic acid were low in the seeds of hemp accessions, perilla and evening primrose. The ratio of GLA in fatty acid profile of evening primrose and hemp seeds were 12.5% and 2.1 %, respectively but not detected in perilla seeds. In the fatty acid profile of hemp seeds accessions, the range and coefficient of variation of GLA were $0.8%{\sim}3.8%$ and 42.9%, respectively which are highest among the fatty acid. Among the major characteristics and fatty acid ratios, flowering date and ${\alpha}-linolenic$ acid showed highly positive correlation but not showed any significant correlation between THC (Tetrahydrocannabinol) and any fatty acids. Among the fatty acid ratios, negative correlation were showed between palmitic acid and ${\gamma}-linolenic$ acid, and showed highly negative correlation between oleic acid and ${\alpha}-linolenic$ acid, linoleic acid and a-linolenic acid. The accessions of high GLA ratio were originated from Europe including Central Russia, and were short in flowering date and stem height.

A Study of Valid Measurement in Science Related Attitudes (II) - To Develop an Affective Component of Attitudes toward Science Scale- (과학 관련 태도의 타당한 측정을 위한 연구 II - "과학에 대한 태도"의 감정적 요소 측정을 위한 척도 개발-)

  • Lee, Kyung-Hoon;Woo, Jong-Ok
    • Journal of The Korean Association For Science Education
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    • v.16 no.2
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    • pp.190-199
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    • 1996
  • The purpose of this study was twofold: (1) to design a system for constructing Likert attitude scales as supported by the sociopsychological and measurement literature, and (2) (using the design) to develop an affective component of "Attitudes toward Science" scale for high school students. The rationale for developing a new attitude scale is presented in the context of a review of existing attitude scales. As discussed in the literature review, many existing attitude scales are based on ill-defined theoretical constructs, and includes statements that do not appear to be assessing a single construct of attitude toward science. In addition, existing attitude scales do not distinguish between affective and behavioral and cognitive components of attitude toward science. Thus, this study was to carefully define the construct, subcomponents of attitude toward science, and develop an affective component of "Attitude toward Science" scale to reflect the construct and to distinguish between affective and behavioral and cognitive components of attitude toward science. The results of this study: (1) three-mains step for designing reliable and valid attitude scale were developed, and (2) 35 items(16 positive and 19 negative) for an affective component of "Attitudes toward Science" scale with the following characteristics were developed: (a) The internal consistency was estimated using Cronbach's coefficient ${\alpha}$, 0.9727. (b) The range of adjusted item-total correletion(${\gamma}$-value) were 0.58${\sim}$0.83. (c) The correlation coefficient ranged between 0.61 and 0.74 revealing a moderate relatedness between subcomponents. (d) The correlation coefficient for concurrent validity were 0.55 with TOSRA and 0.51 with SAl.

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Modelling land surface temperature using gamma test coupled wavelet neural network

  • Roshni, Thendiyath;Kumari, Nandini;Renji, Remesan;Drisya, Jayakumar
    • Advances in environmental research
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    • v.6 no.4
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    • pp.265-279
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    • 2017
  • The climate change has made adverse effects on land surface temperature for many regions of the world. Several climatic studies focused on different downscaling techniques for climatological parameters of different regions. For statistical downscaling of any hydrological parameters, conventional Neural Network Models were used in common. However, it seems that in any modeling study, uncertainty is a vital aspect when making any predictions about the performance. In this paper, Gamma Test is performed to determine the data length selection for training to minimize the uncertainty in model development. Another measure to improve the data quality and model development are wavelet transforms. Hence, Gamma Test with Wavelet decomposed Feedforward Neural Network (GT-WNN) model is developed and tested for downscaled land surface temperature of Patna Urban, Bihar. The results of GT-WNN model are compared with GT-FFNN and conventional Feedforward Neural Network (FFNN) model. The effectiveness of the developed models is illustrated by Root Mean Square Error and Coefficient of Correlation. Results showed that GT-WNN outperformed the GT-FFNN and conventional FFNN in downscaling the land surface temperature. The land surface temperature is forecasted for a period of 2015-2044 with GT-WNN model for Patna Urban in Bihar. In addition, the significance of the probable changes in the land surface temperature is also found through Mann-Kendall (M-K) Test for Summer, Winter, Monsoon and Post Monsoon seasons. Results showed an increasing surface temperature trend for summer and winter seasons and no significant trend for monsoon and post monsoon season over the study area for the period between 2015 and 2044. Overall, the M-K test analysis for the annual data shows an increasing trend in the land surface temperature of Patna Urban.

A Study on Self-Esteem, IADL, and Life Satisfaction in the Elderly (가정노인과 양로원노인의 자아존중감, 일상생활활동능력, 생활만족도에 관한 연구)

  • 김정선
    • Journal of Korean Academy of Nursing
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    • v.28 no.1
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    • pp.148-158
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    • 1998
  • This study was designed to identify degrees of self-esteem instrumental activities of daily living and life satisfaction in the elderly and to investigate the relationship between these factors thus contributing to effective nursing interventions to promote quality of life for both noninstitutionalized and institutionalized elderly. The subjects for this study included 130 noninstitutionalized and institutionalized elderly. The data were collected through personal interviews using a questionnaire, the time being from August 25 to September 7, 1997. The measurement tools were the Self-esteem Scale Developed by Rosenberg and translated by Jon, Byong Je (1974). the IADL scale develped by Lawton & Brody(1968). and the Life Satisfaction developed by Youn. Jin(1982).The data were analyzed by the S.P. S.S computer progam and included descriptive stasistics, t-test, One way ANOVA and Pearson correlation coefficient. The conclusions of this study are summerized as follows ; 1. There was a significant difference in Self-Esteem(t=7.05, P=.000). IADL(t=4.36, P=.000). and Life Satisfaction(t=6.63, P=.000) between the noninstitutionalized elderly and the institutionalized elderly. 2. There was a significant positive correlation between self-esteem and IADL(${\gamma}$=.4028). self-esteem and life satisfaction(${\gamma}$=.6415). and IADL and life satisfaction(${\gamma}$=.3884) in the noninstitutionalized elderly(P<.001). and between self-esteem and life satisfaction(${\gamma}$=.3883, P<.001). IADL and life satisfation(${\gamma}$=.2501, P<.05) in the institutionalized elderly. 3. According to the general characteristics of the noninstitutionalized and institutionalized elderly : Self-Esteem of the noninstitutionalized elderly was significantly different. according to educational level(F=4.491, P=.031). job(F=2.53, P=.044). living expense load(F=2.861. P=.044). and self-esteem, and of the institutionalized elderly, it was significantly different according to educational level only (F=4.480, P=.006). IADL of the noninstitutionalized elderly was significantly different according to age(F=3.018, P=.021). living expense load(F=3.034. P=.033). pocket money(F=3.606. P=.010). and for the institutionalized elderly, it was significantly different according to age(F=2.899, P=.042), and religion(F=2.847, P=.044). Life Satisfaction of the noninstitutionaized elderly( F=2.718, P=.037) and instiutionalized elderly(F=3.165, P=.030) was significantly different according to pocket money.

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Precise prediction of radiation interaction position in plastic rod scintillators using a fast and simple technique: Artificial neural network

  • Peyvandi, R. Gholipour;rad, S.Z. Islami
    • Nuclear Engineering and Technology
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    • v.50 no.7
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    • pp.1154-1159
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    • 2018
  • Precise prediction of the radiation interaction position in scintillators plays an important role in medical and industrial imaging systems. In this research, the incident position of the gamma rays was predicted precisely in a plastic rod scintillator by using attenuation technique and multilayer perceptron (MLP) neural network, for the first time. Also, this procedure was performed using nonlinear regression (NLR) method. The experimental setup is comprised of a plastic rod scintillator (BC400) coupled with two PMTs at two sides, a $^{60}Co$ gamma source and two counters that record count rates. Using two proposed techniques (ANN and NLR), the radiation interaction position was predicted in a plastic rod scintillator with a mean relative error percentage less than 4.6% and 14.6%, respectively. The mean absolute error was measured less than 2.5 and 5.5. The correlation coefficient was calculated 0.998 and 0.984, respectively. Also, the ANN technique was confirmed by leave-one-out (LOO) method with 1% error. These results presented the superiority of the ANN method in comparison with NLR and the other methods. The technique and set up used are simpler and faster than other the previous position sensitive detectors. Thus, the time, cost and shielding and electronics requirements are minimized and optimized.

Association between Medical Costs and the ProVent Model in Patients Requiring Prolonged Mechanical Ventilation

  • Roh, Jiyeon;Shin, Myung-Jun;Jeong, Eun Suk;Lee, Kwangha
    • Tuberculosis and Respiratory Diseases
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    • v.82 no.2
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    • pp.166-172
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    • 2019
  • Background: The purpose of this study was to determine whether components of the ProVent model can predict the high medical costs in Korean patients requiring at least 21 days of mechanical ventilation (prolonged mechanical ventilation [PMV]). Methods: Retrospective data from 302 patients (61.6% male; median age, 63.0 years) who had received PMV in the past 5 years were analyzed. To determine the relationship between medical cost per patient and components of the ProVent model, we collected the following data on day 21 of mechanical ventilation (MV): age, blood platelet count, requirement for hemodialysis, and requirement for vasopressors. Results: The mortality rate in the intensive care unit (ICU) was 31.5%. The average medical costs per patient during ICU and total hospital (ICU and general ward) stay were 35,105 and 41,110 US dollars (USD), respectively. The following components of the ProVent model were associated with higher medical costs during ICU stay: age <50 years (average 42,731 USD vs. 33,710 USD, p=0.001), thrombocytopenia on day 21 of MV (36,237 USD vs. 34,783 USD, p=0.009), and requirement for hemodialysis on day 21 of MV (57,864 USD vs. 33,509 USD, p<0.001). As the number of these three components increased, a positive correlation was found betweeen medical costs and ICU stay based on the Pearson's correlation coefficient (${\gamma}$) (${\gamma}=0.367$, p<0.001). Conclusion: The ProVent model can be used to predict high medical costs in PMV patients during ICU stay. The highest medical costs were for patients who required hemodialysis on day 21 of MV.

Performance Evaluation of Several Radon Detectors in the Standard Chamber and Dwellings (라돈 표준실과 가옥 내에서 일부 라돈검출기에 대한 성능 평가)

  • Yoon, Seok-Won;Kim, Yong-Jae;Chang, Byung-Uck;Byun, Jong-In;Yun, Ju-Yong
    • Journal of Radiation Protection and Research
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    • v.33 no.4
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    • pp.173-181
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    • 2008
  • To ensure the performance of radon detectors, three passive radon detectors ($RadTrak^{(R)}$, $Radopot^{(R)}$, and $E-PERM^{(R)}$)have been reviewed. The difference ratios of RadTrak and Radopot tested in the radon standard chamber were -13.2% and -6.0%, respectively, which were in good accordance within 20% of the value measured by $AlphaGUARD^{(R)}$. To ensure the performance of the long term measurement, the 3 detectors were installed at the same position of approximately one hundred of dwellings for one year. The correlation curve between RadTrak and Radopot shows good agreement with a correlation coefficient ($R^2$) of 0.91. However, The correlation curve between E-PERM and Radopot shows bad agreement ($R^2$ = 0.021). In addition, the distribution map of annual mean indoor gamma dose rate measured with E-PERM was not in accordance with the distribution map of outdoor gamma dose rate measured by Portable Ion Chamber. According to the results, some requisites for the selection of the radon passive detectors in the large-scale indoor radon survey were discussed.