• Progress in Medical Physics
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• v.26 no.1
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• pp.28-35
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• 2015

In this study, we investigated the effects of an iterative reconstruction algorithm and an automatic exposure control (AEC) technique on image quality and radiation dose through phantom experiments with coronary computed tomography (CT) angiography protocols. We scanned the AAPM CT performance phantom using 320 multi-detector-row CT. At the tube voltages of 80, 100, and 120 kVp, the scanning was repeated with two settings of the AEC technique, i.e., with the target standard deviations (SD) values of 33 (the higher tube current) and 44 (the lower tube current). The scanned projection data were reconstructed also in two ways, with the filtered back projection (FBP) and with the iterative reconstruction technique (AIDR-3D). The image quality was evaluated quantitatively with the noise standard deviation, modulation transfer function, and the contrast to noise ratio (CNR). More specifically, we analyzed the influences of selection of a tube voltage and a reconstruction algorithm on tube current modulation and consequently on radiation dose. Reduction of image noise by the iterative reconstruction algorithm compared with the FBP was revealed eminently, especially with the lower tube current protocols, i.e., it was decreased by 46% and 38%, when the AEC was established with the lower dose (the target SD=44) and the higher dose (the target SD=33), respectively. As a side effect of iterative reconstruction, the spatial resolution was decreased by a degree that could not mar the remarkable gains in terms of noise reduction. Consequently, if coronary CT angiogprahy is scanned and reconstructed using both the automatic exposure control and iterative reconstruction techniques, it is anticipated that, in comparison with a conventional acquisition method, image noise can be reduced significantly with slight decrease in spatial resolution, implying clinical advantages of radiation dose reduction, still being faithful to the ALARA principle.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.1938-1945
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• 2014

This study intends to investigate physical trauma in the adolescent during exercise of teenage elite judo players in Seoul. The subjects were male 67, female 14, totally 81 in middle and high school student and the data collected june the first to 28th, 2013. A data were analyzed frequency analysis, chi-square test and t-test using SPSS 16.0 program. The questionaire was contained 6 categories, experience, region, types, time, causes, intervention and preventionof sports injury. The highest results of each categories of this study is that experience of injury is 77(95.1%), region is knee 35(70.0%), type is contusion 42(54.5%), time is summer 54(70.1%), cause is body crash 40(51.9%), and intervention is going hospital 46(59.7%). To prevent physical trauma, we should recognize physical trauma durind exercise as a health problem. And to prevent physical trauma, relatives should make prevention prorgram for adolescent sports players. It will improve their quality of life.

• The Korean Journal of Zoology
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• v.29 no.3
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• pp.201-207
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• 1986

The authors attempted to investigate the oxygen consumption rate of sexuals in the water-striders, Gerris paludum insuralis, at four temperature groups of 25, 30, 35 and $40^\\circ C$ in a series of studies on respiration of a heminetabolous insects. THe results are summarised as follows: (1) At $30^\\circ C$, the change of oxygen consumption rate according to the lapse of time was small in comparison with the other three temperature groups which shows a cyclic decreasing pattern. The rate during initial and final 5 minutes was much alike. Thereupon, the optimum temperature was regarded as $30^\\circ C$. (2) The oxygen consumption rate of male was higher than that of female. (3) The oxygen consumption rates at 25, 30, 35 and $40^\\circ C$ were 0.42, 0.49, 0.79 and 1.11 $\\mu$l/mg/h respectively. That is, the rate was increased as the temperature was increased. (4) The $Q_10$ of male showed a high value in the lower temperature interval ($25^\\circ C \\sim 35^\\circ C$), but the female showed a high value in the higher temperature interval ($30^\\circ C \\sim 40^\\circ C$). The mean $Q_10$ was 2.12. (5) The respiratory rate was decreased as the body weight was increased in the above fresh weight of 10mg and dry weight 5 mg. (6) The upper temperature threshold for respiration was $48.31^\\circ C$ and the lower temperature threshold was $17.68^\\circ C$. (7) The ceasing time of breathing at the other three temperature groups except $30^\\circ C$ was infered to be about 110 minutes after the start of experiment.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.9
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• pp.605-612
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• 2016

In this study, numerical simulations were conducted for conjugate heat transfer around ice balls in an encapsulated ice thermal storage system. Four shapes of ice balls were modeled; the default one was a sphere, and the other three shapes were designed to enhance convective heat transfer through the ball surface. The flow around the ball was laminar, for which the Reynolds number was 300, and both forced and natural convections inside and outside the balls were considered. The simulations revealed that the magnitude of convective heat transfer for the different shapes decreased in the following order: bone, dimple, hole, and sphere. For the entire simulation, the maximum difference in the average temperatures of water inside the capsules was found to be $0.9^{\circ}C$. Therefore, it can be said that the effect of ice-ball shape on the performance of the ice thermal storage system is significant, considering that more than 0.3 million balls are used in this system.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.9
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• pp.597-604
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• 2016

A parallel algorithm of bi-conjugate gradient method was developed based on CUDA for parallel computation of the incompressible Navier-Stokes equations. The governing equations were discretized using splitting P2P1 finite element method. Asymmetric stenotic flow problem was solved to validate the proposed algorithm, and then the parallel performance of the GPU was examined by measuring the elapsed times. Further, the GPU performance for sparse matrix-vector multiplication was also investigated with a matrix of fluid-structure interaction problem. A kernel was generated to simultaneously compute the inner product of each row of sparse matrix and a vector. In addition, the kernel was optimized to improve the performance by using both parallel reduction and memory coalescing. In the kernel construction, the effect of warp on the parallel performance of the present CUDA was also examined. The present GPU computation was more than 7 times faster than the single CPU by double precision.

• Journal of Microbiology and Biotechnology
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• v.15 no.6
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• pp.1323-1329
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• 2005

A mathematical model was developed for predicting the growth kinetics of Listeria monocytogenes in tryptic soy broth (TSB) as a function of combined effects of temperature, pH, and NaCl. The TSB containing four different concentrations of NaCl (2, 4, 5, and $10\%$) was initially adjusted to six different pH levels (pH 5, 6, 7, 8, 9, and 10) and incubated at 4, 10, 25, or 37$^{circ}C$. In all experimental variables, the primary growth curves were well fitted ($r^{2}$=0.982 to 0.998) to a Gompertz equation to obtain the lag time (LT) and specific growth rate (SGR). Surface response models were identified as appropriate secondary models for LT and SGR on the basis of coefficient determination ($r^{2}$=0.907 for LT, 0.964 for SGR), mean square error (MSE=3.389 for LT, 0.018 for SGR), bias factor ($B_{1}$B,=0.706 for LT, 0.836 for SGR), and accuracy factor ($A_{f}$=1.567 for LT, 1.213 for SGR). Therefore, the developed secondary model proved reliable predictions of the combined effect of temperature, NaCl, and pH on both LT and SGR for L. monocytogenes in TSB.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.3
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• pp.293-297
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• 2010

Purpose: The aim of the current study was to compare body mass index (BMI) with waist circumference (WC) as a predictor of elevated intraocular pressure (IOP). Methods: The subjects were consisted of 458 adults, aged 20 year or above, of one community in Kyunggi-do. Mean IOPs were stratified jointly for BMI and WC tertiles. Multi-variate linear regression analysis was also used to compare between BMI and WC. Results: Although any BMI tertiles were not associated with IOP within each tertile of WC, WC tertiles was significantly related to elevation of IOP within the third BMI tertile (${\geq}24.9kg/m^2$). After adjusting for age and sex, only WC showed significant association with IOP. In additional adjustment for lifestyle variables, both BMI and WC were significantly associated with elevation of IOP. However, the results showed the stronger association of IOP with WC than BMI, whether they were adjusted by age and sex or additionally lifestyle variables. Conclusions: These data showed that BMI and WC were positively associated with IOP. However, WC appeared to be a better indicator for higher IOP than BMI.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.185-205
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• 2017

The purpose of this research is to examine the relationship between the adult attachment of married employees, their job motivation and marital relationship. For this purpose, a questionnaire survey was carried out with 370 married employees in the Chungnam area as the target from Sep. 10 to Oct. 14, 2016. The collected data was analyzed using SPSS 23.0 using descriptive statistical analysis, the independent sample T-test, ANOVA analysis, Pearson correlation, and structural equation analysis. First, significant differences were revealed in the level of attachment avoidance, satisfaction with the marriage relationship, and job motivation according to the age group, in the level of attachment avoidance and satisfaction with the marriage relationship according to the education level, in the level of attachment avoidance and satisfaction with the marriage relationship according to the marriage period, in job motivation according to the position, in satisfaction with the marriage relationship according to the average household income, and in satisfaction with the marriage relationship according to the work shift pattern. Second, although a significant negative correlation appeared between attachment anxiety and attachment avoidance, a significant positive correlation was found between attachment avoidance and job motivation. Also, although a significant negative correlation appeared between attachment avoidance and marital relationship, a significant positive correlation was found between job motivation and marital relationship. Third, to examine the mediating effect of satisfaction with the marital relationship on the relationship between adult attachment and job motivation, a structural equation analysis was carried out. As a result, the indirect effect of attachment anxiety on job motivation turned out to be significant and its complete mediating effect was confirmed. This suggests that when developing programs to improve job motivation within the workplace or consultative interventions for the enhancement of marital relationships, the above characteristics of individuals should be taken into consideration.

• Women's Health Nursing
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• v.5 no.3
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• pp.313-326
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• 1999

This study sought to find out the level of perception of postpartal care and the meaning and opinion of traditional postpartal care (Sanhujori) from health professional. The subjects were 188 health professionals who work at University hospital, clinics, Oriented clinics, and midwifery clinics in Seoul and Chung-Buk, Korea. Data were collected from 8th April, 1999 to 6th May, 1999. The data were analyzed through the SPSS program by use of frequency, percentage, t-test, ANOVA and Scheffe test as a post hoc contrast, $x^2$-test, and stepwise multiple regression. The results of the study were as follows: mean age of the subject was 33.0 years and female was 58.0%. Occupation of the subject was nurse 28.7%, doctor 22.3%, midwife 21.3 Korean Oriental doctor 27.0%. Mean period of career was 7.6 years and the subject who experienced Sanhujori was 54.3%. The subject who did not know 6 principles of Sanhujori was 73.9%. In the opinion on traditional Sanhujori method 68.1% of respondents expressed that Sanhujori is scientific postpartal care which fits Korean people's physical constitution and culture. On the opinion of effective postpartal care in 97.9% of respondents expressed that it is to in hospital postpartal care and traditional Sanhujori perform it according to Korean culture constitution. On the opinion of Sanhujori, 96.6% of respondents expressed that it is necessary to understand Sanhujori with consideration which was adapted to Oriental culture and to verify it through continual study. On the opinion of the effect of the level of performance of Sanhujori upon women's health life, 43.2% of respondents expressed that the level of performance of Sanhujori has great effect on women's general health, including postpartal recovery, Sanhujori prevention, and so on. On the opinion of Sanhujori of women who undergo Caesarean operation, 57.7% of respondents expressed that women who undergo Caesarean operation perform Sanhujori with more attention. On the opinion of Sanhujori center (sanhujorwon), 56.3% of respondents expressed that the center is necessary for women's health and health professional are required to manage the center scientifically. On considering the level of importance of post care according to occupation, midwife showed highest level of importance of traditional Sanhujori doctor the lowest level. Midwife showed the hi level of importance of postpartal care and K Oriental doctor showed the lowest level of importance of women's postpartal care. On considering the relationship between the level of importance of postpartal care and general characteristics, sex, career, clinical department and whether they know 6 principles of Sanhujori or not were statistically significant at the level of 5%. In the stepwise multiple regression analysis, the main influencing variables on the level of importance of postpartal care were occupation, sex, and clinical department. In conclusion, this finding confirmed that professionals were considering the traditional Sa importantly for women's health. Above all things necessary for health professional to integrate concept of traditional Sanhujori into practical nu intervention program, to apply it to profes practices in order to reestablish effective integrative postpartal caring system, and to Sanhujori scientific through performing continual research.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.27 no.4
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• pp.196-205
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• 2017

In recent years, the service design in the medical sector evolves through practical service research and development that can visualize both intangible and intangible service elements in an integrative way and derive innovative solutions to help customers feel the service more important value. With the improvement of personal income, interest in medical welfare and well-being is increasing day by day, and the focus of the medical sector shifts from the concept of treatment of diseases and illness to preventive medicine. In response to this trend, research and development of home health care system, which greatly reduces the time and space constraint of health checkup and health care by combining ubiquitous concept with medical welfare, are being actively conducted, and the needs for improving products and medical environment based on user-centered medical service and user needs in accordance with the Health Care 3.0 Era, it becomes necessary to develop on-site medical diagnostic products that reflect user-centered needs and needs. This study is intended to research and develop a product that sufficiently reflects the needs of users by applying suitable materials and shape for on-site diagnostic product in researching and developing Wireless X-ray Detector.