• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.7 no.1
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• pp.9-16
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• 2009

Transport package for radioactive material should be structurally safe under puncture drop condition and its safety should be verified by test and numerical analysis. Most finite element analyses for puncture drop have been performed without modeling the impact limiter since failure is occurred in the materials of the impact limiter. This paper presents a new modeling methodology, where an element is eroded in case that the material's failure criteria are reached at the element's integration point, to investigate the effect of the impact limiter in the puncture process. The effectiveness of the proposed scheme is shown through the puncture drop analysis of hotcell transport cask, which is under design in KAERI. The results show that about 80 percent of the total impact energy is absorbed due to the deformation of impact limiter. Using the present method the puncture drop can be analyzed more accurately, but it would give conservative results compared to the actual test condition.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.3
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• pp.1-7
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• 2010

Recently, the vehicle driving device has been designed for driver's convenience. Especially, the automobile industry develops the vehicle using the joystick instead of steering wheel from the concept car. The biggest strength of using the joystick is that the driver feels less workload and fatigue than when the driver uses steering wheel. However, this kind of study still needs more research and experiments for more accurate result. Therefore, this research evaluated workload according to the driving device by the survey and the measurement of physiological signal. The reason not only using the survey also using the measurement of physiological signal is to support the result of the survey which is not enough to bring the accurate result. There were tow different kinds of methods to carry out this research; SWAT (Subjective Workload Assessment Technique) for the survey and the biopac equipment for the measurement of physiological signal. Furthermore, previously established driving simulator, GPS (Global Positioning System), and Seoul-Cheonan virtual expressway DB were used for the experiment. As the result of the experiment with 13 subjects, it was certain that using joystick device brings less workload and fatigue to the drivers than using steering wheel following both methods-the survey and the measurement of physiological signal. Also, it confirmed the significant result from the SPSS (Statistical Package for the Social Sciences) statistics analysis program.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5467-5473
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• 2014

This study examined the numerical analysis results with respect to the thermal behavior of a natural convection cooled pin-fin heat sink. The heat sink consisted of pin fins integrated with plate fins. The heat sinks were designed with two different types to fit the limited internal space. The two types of heat sinks designed were analyzed using the ANSYS software package, and the numerical analysis results were compared with the cooling performance of the two types of heat sinks. The results of the simulation were analyzed according to the temperature distribution and air flow characteristics, heat flux etc. This study examined the correlation of the cooling performance with the heat sink internal structure and fin shape. FEM (Finite Element Method) confirmed the cooling performance of heat sink type A under natural convection conditions as the best results. The results of the numerical simulation showed that the heat sink type A shape showed an approximately 70 percent better heat transfer rate with natural convection than that of type B.

• Journal of Astronomy and Space Sciences
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• v.20 no.2
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• pp.143-152
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• 2003

We constructed the photometric observation system with a small semi-automatic telescope for the systematic observations of eclipse timings of eclipsing binary stars. The system is consisted of a Paramount GT-1100s mount system, a Celestron 14 optical system, and a SBIG ST-8 camera. We developed the OBSTOOL S/W which controls the telescope and the CCD camera using the COM(Component Object Model) supported by the softwares, The Sky and MaximDL. The system performs photometric observations of a variable, comparison and check stars by moving the telescope to the chosen star separately in a similar way such as the method of photoelectric observation. We wrote pert scripts which enable a data handling pipeline for the obtained data to be classified by each of date, object and filter. And thus the images are easily preprocessed using the IRAF S/W package. Eclipse light curves of some eclipsing binary stars observed with this system are presented.

• Journal of Korean Library and Information Science Society
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• v.47 no.4
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• pp.1-18
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• 2016

The purpose of this study is to explore application of topic modeling for topic analysis of book report. Topic modeling can be understood as one method of topic analysis. This analysis was conducted with texts in 23 book reports using LDA function of the "topicmodels" package provided by R. According to the result of topic modeling, 16 topics were extracted. The topic network was constructed by the relation between the topics and keywords, and the book report network was constructed by the relation between book report cases and topics. Next, Centrality analysis was conducted targeting the topic network and book report network. The result of this study is following these. First, 16 topics are shown as network which has one component. In other words, 16 topics are interrelated. Second, book report was divided into 2 groups, book reports with high centrality and book reports with low centrality. The former group has similarities with others, the latter group has differences with others in aspect of the topics of book reports. The result of topic modeling is useful to identify book reports' topics combining with network analysis.

• Korean Journal of Applied Biomechanics
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• v.16 no.4
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• pp.115-124
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• 2006

This study was conducted to investigate the running motion in the max-velocity phase(150-160m) and the fatigue phase(350-360m) during 400m sprint by performed elementary school athletes. Eighteen elementary school male athletes who achieved at least the 3rd place in the sprint at the Korea Gangwon-Do elementary school track and field meetings during 2004 and 2005 were selected as subjects. The running motions performed by the subjects were recorded using two 8mm high speed cameras at the nominal speed of 100 frames per second. The Direct Linear Transformation technique was adopted from the beginning of filming to the final stage of data extraction. KWON 3D motion analysis package program was used to compute the 3 Dimensional coordinates, smoothing factor in which lowpass filtering method was used and cutoff frequency was 6.0 Hz. The movement patterns during foot touchdown and takeoff for the running stride were related with the biomechanical consideration. Within the limitations of this study it is concluded: In order to increase running velocity, several conditions must be fullfilled at the instant of leg touchdown and takeoff during the fatigue phase(350-360m). First, the body C.O.G(Center of Gravity) height should be raised at the instant of leg touchdown and takeoff during the fatigue phase. Second, the foot contact time should be shortened and the takeoff distance should be increased at the foot takeoff during the fatigue phase. Third, the shank angular velocity with respect to a transverse axis through the center of gravity should be increased during the leg touchdown and takeoff in the fatigue phase. Forth, the active landing style described as clawing the ground with the sole of the foot should be performed during the leg touchdown and takeoff in the fatigue phase) phase. Fifth, In order to increase running velocity in the fatigue phase while taking a slightly greater leg knee angle and body lean angle within the range of the subject's running motion during the fatigue phase would result in greater flight distance.

• Journal of the Korean Society of School Health
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• v.11 no.1
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• pp.91-97
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• 1998

The main purpose of this study was to develop, implement, and evaluate a weight control program for overweight elementary school children The results of our previous study in 1996 Identified overweight as one of several health problems among elementary school children in urban areas The research method utilized was a quasi experimental design using one group in a pre and post test comparison The sample consisted of 198 children from 3 elementary schools in Kyung-gi Province who were 20% over the ideal weight for their height Height and weight were measured and a BMI score was calculated at the beginning of the program and monthly thereafter. The program had three components: physical exercise, counseling of children, and health education of children, parents, and teachers. The program lasted from March, 1997 to November, 1997. The data were analyzed using an SAS PC statistical package. The results indicate that the overweight children in two elementary schools had statistically Significant changes in their BMI score after the program while those in one school id not. When the process notes were reviewed it was Identified that the school which showed little change averaged less physical exercise, and less parent and teacher participation in the program In conclusion, a school based weight control program is an effective way to manage and prevent obesity for overweight elementary school children It is suggested that a school wide exercise program may be better accepted by overweight children than a program specifically designed for overweight children only. One of the most important factors which determine the successful outcome of any health promotion project in school is the enthusiasm and cooperation of the principal and school health nurse.

• Journal of Korean Academy of Nursing Administration
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• v.8 no.2
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• pp.249-259
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• 2002

Purpose: This study was to identify the relationship between transformational leadership of nurse managers and autonomy, empowerment of nurses. Method: The subjects were 468 nurses and 19 head nurses were working at the 3 general hospitals in seoul. The data were collected from July 6 to September 14, 2001 by the structured questionnaires. For data analysis, descriptive statistics, ANOVA, Pearson correlation coefficient, and stepwise multiple regression with SAS package were used. Result: 1) 'Autonomy' and 'Empowerment' were positively related to 'Total Transformational Leadership', 'Charisma', 'intellectual stimulation', 'individual consideration'($r=.18{\sim}24$, $r=.26{\sim}36$, p<.001). 2) 'Transformational leadership' showed a significant difference according to major field of practice(F=4.47, p<.001). 3) 'Autonomy' showed a significant difference according to age, education level, total numbers of years in nursing practice, and position in present(F=3.68, 3.27, 3.13, 4.34, p<.05). 4) 'Empowerment' showed a significant difference according to age, marital status, education level, major field of practice, total numbers of years in nursing practice, and position in present(F=16.02, t=9.04, F=6.97, 1.86, 15.71, 11.38, p<.05). 5) As a result of regression analysis, the key determinants of 'autonomy' were 'Charisma' and this explained 10.61% of the total variance of it. And the key determinants of 'empowerment' were 'intellectual stimulation' and this explained 16.01% of the total variance of it.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.11
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• pp.4555-4561
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• 2015

Background: Mammography screening is a method for reducing breast cancer mortality in women over 40 years old. A participation rate of at least 70% is a prerequisite for screening programs. This study aimed at determining the participation rate of women in breast cancer screening in Iran. Materials and Methods: The study population in this prospective research consisted of 35 to 69 years old women in the villages and towns Kerman District, in 2013. The data were collected by a well-validated risk assessment questionnaire. The questionnaires were completed with the help of health workers and technicians in the health centers, who were trained on breast cancer screening program. Results: As a whole, 19,651 women were invited to complete the questionnaire, of whom 15,794 women (80.37%) completed it. In the urban region, of 3150 eligible women 2728 women (86.60%) participated in the study. The acceptance rates for mammography in rural and urban regions were 34.95% and 8.75%, respectively. Conclusions: Finally, 3.8% and 16.34% of 35 to 69 years old women in the urban regions were mammographed, respectively. Conclusion: The low participation of eligible women in breast cancer screening program alerts us against including the program in the health insurance package.

• The Journal of the Acoustical Society of Korea
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• v.34 no.6
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• pp.470-478
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• 2015

A heuristic method treating a layered ocean bottom in a ray modeling is to use the plane wave reflection coefficient for multiple-layered structure, named an one-layer assumption in this paper. We examine the validity of one-layer assumption in the case of two-layered ocean bottom, and obtain a simple inequality condition depending on the sound speed ratio, the ratio of layer thickness to source-receiver range, and the grazing angle of first reflected ray. From this inequality condition, it is shown that an one-layer assumption can be applicable to ray propagation problems at mid frequencies. Finally, numerical experiments are performed in the ocean environment similar to the East Sea in Korea. Incoherent transmission loss is calculated by the geometrical beam model with the plane wave reflection coefficient for multiple-layered ocean bottom and compared with the result of SNUPE 2.0, which is a parabolic equation package developed in Seoul National University.