• The Journal of the Korea Contents Association
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• v.11 no.1
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• pp.236-244
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• 2011

Recently, the number of interventional procedures has increased dramatically as an alternative of invasive surgical procedure. The need for the quality control program of the angiographic units has also increased, because of concerns about the increased patient dose and the importance of image quality of angiographic units for the successful procedures. The purpose of this study was to propose an optimal guideline for the quality control program of the angiographic units. We reviewed domestic and international standards about medical imaging system and we evaluated the quality of 61 angiographic units in Korea with the use of NEMA 21 phantom. According to the results of our study, we propose a guideline for the quality control program of the angiographic units. Quality control program includes tube voltage test, tube current test, HVL test, image-field geometry test, spatial resolution test, low-contrast iodine detectability test, wire resolution test, phantom entrance dose test. Proposed reference levels are as follows: PAE < $\pm$ 10% in tube voltage test, PAE < $\pm$ 15% in tube current test, minimum 2.3 mmAl at 80 kVp in HVL test, minimum 'acceptable' level at image-field geometry test, 0.8 lp/mm for detector size of 34-40cm, 1.0 lp/mm for detector size of 28-33cm, 1.2 lp/mm for detector size of 22-27cm in spatial resolution test, minimum 200mg/cc in low contrast iodine detectability test, phantom entrance dose should be under 10R/min, 0.012 inch wire should be seen at static wire resolution test, and 0.022 inch wire should be seen at moving wire resolution test.

• Journal of the Korean Home Economics Association
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• v.35 no.4
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• pp.111-124
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• 1997

The purpose of this study was to find out the effects of children's elementary school entrance age and sex on cognitive and social abilities. The subjects were 80 the same number was slected by elementary school entrance age(5-year and 6-year) and sex. Their cognitive and social abilities were measured by Intelligence Maturity Test and Revised Vineland Adaptive Behavior Scales. The data were statistically analyzed including descriptive statistics and multivariate analysis of variance. The results were as follows: 1) 6-year-old children had higher perceptive ability of sameness and calculation ability than 5-year-old children. Girls also had higher IQ and language concept than boys, 2) 6-year-old children's communication socialization and total social ability were higher than those of 5-year old children Girls' communication and total social ability were higher than those of boys. The implication was that it would be important to consider children's social ability if their entrance age were decided. In addition Early Entrance to Elementary School system should be reconsidered in the point of childer's developmental adaptation.

• East Asian mathematical journal
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• v.33 no.4
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• pp.467-482
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• 2017

This paper studies the relationship between the college entrance examination scores and college mathematics achievements of the freshman, who are the students of college of technology and management in Yanbian University, by employing statistical analysis. First of all, we start from the correlation analysis of the majors and regions of students. Secondly, with gender and region as the classification, we divide the sample into two parts and test the mean significance, and we find that not only different gender but also different region have significant differences to college mathematics achievements. Thirdly, we use the college entrance examination scores as independent variable, and college mathematics achievement as the dependent variable to establish regression model. The model provides a realistic basis for the education department of our school, and provides reference value for the other major research.

• Journal of the Korean Society for Railway
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• v.5 no.2
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• pp.112-117
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• 2002

Reduction of noise level in the cabin of urban transit unit is an important issue to enhance the comfortability of passengers. It is made clear that a cause of increased noise level in cabin is the imperfect airtightness of entrance doors. In this study, the sliding-plug door system is developed to reduce the noise level of cabins by securing the airtightness of entrance door. The sliding-plug door system is composed of air-driven engine, swing arms, guide rails, guide rollers and locking devices. It is economical owing to using the previous door engine system. It is also adequate for the platform system of our subway station. It was tested to prove the reliability of system and was applied to standard urban transit unit. The effectiveness of noise reduction in cabin resulting form the sliding-plug door system was confirmed by test results.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.5
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• pp.1032-1043
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• 1989

The heat transfer characteristics of the drag reducing polymer solutions are investigated experimentally in the thermal entrance region of circular tube flows. Fluids used in experiments are the aqueous solutions of high molecular polymer, polyacrylamide Separan AP-273 and the range of polymer concentrations is from 20 to 1000 wppm. Two stainless steel tubes with inside diameter 8.5mm(L/D=712) and 10.3mm(L/D=1160) are used for the heat transfer flow loops. The flow loop is set up to measure friction factors and heat transfer coefficients of test sections in two different modes; the recirculating flow system and once-through flow system. The test tubes are heated directly by electricity to apply the constant heat flux boundary conditions to the wall. Three different types of adaptors are used to observe the effects of the upstream flow conditions of the heat transfer test sections. The viscosity and characteristic relaxation time of the test fluids circulating in the flow system are measured by the capillary tube viscometer and falling ball viscometer at regular time intervals. The installed adaptors exhibit slight effect on the entrance heat transfer of Newtonian fluid. However, no noticeable effects are observed for the entrance heat transfer of the drag reducing fluids. The order of magnitude of the thermal entrance lengths of the drag reducing fluids which follow the minimum friction asymptote is much longer than that of Newtonian fluids in turbulent flows. A new dimensionless parameter, the viscoelastic Graetz number, is defined and all the experimental data are recasted in terms of the viscoelastic Graetz number. The local Nusselt number of the viscoelastic fluids is represented as a function of flow behavior index n and the viscoelastic Graetz number. As degradation continues the viscosity and the characteristic relaxation time of the testing fluids decrease. Weissenberg number defined by the relaxation time and D/V appears to be a proper dimensionless parameter in describing degradation effects on heat transfer of the viscoelastic fluids.

• Korea Journal of Hospital Management
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• v.10 no.3
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• pp.1-24
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• 2005

This study purports to investigate the determinants of individual personnel rating of the employees at a university hospital in Seoul, Korea. The sample used in this study consisted of 63 nurses, 41 para-medical staff (Clinical Pathologist, and Radiologist), and 67 administrative staff. Independent variables of the study included the achievement level of the selection test (English, major subject, and interview), post-entrance development factors (education and training, career development, supervisory support, co-worker support, and organizational support), and demographic characteristics. Data for the achievement level of the entrance exam and years for the first promotion were collected from the administrative records of the study hospital, while data for the post-entrance development factors were collected from the survey with self-administered questionnaires using 5-point Likert Scale during June 10-25, 2003. Collected data were analyzed using hierarchical multiple regression. The results of the study showed that achievement level of the interview and English exam at the selection test, education and training, organizational support, and supervisory support while working at the hospital, and length of duration (below 8 years) and educational background (4-year college graduates) among demographic variables had significant positive effects on the personnel rating. The results of the study imply that hospital administrators should make an effort to improve the validity of the selection test, and to motivate the employees to receive more education and training.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.977-980
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• 2011

In this paper, explain to development of low pressure axial compressor performance test rig in KARI. Performance test rig consist of a entrance section, rotor, stator, shaft, rig housing, bearing housing and exit section. Test rig design structural optimization to rotor dynamics analysis of the simplified rotor-shaft assembly and flow analysis of entrance/exit section.

• The Mathematical Education
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• v.49 no.4
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• pp.395-410
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• 2010

Current mathematics of CSAT(College Scholastic Ability Test) faces time to prepare examination questions according to the new curriculum making this year the last. MEST(Minister of Education, Science and Technology) already decided the range of examination in 2008. However, the discuss about how to construct the questions and what form of questions should be set was not conducted enough. Mathematics items of CSAT will have to undergo changes both in 2012 and 2014. Also, reconstruction of the examination questions for the past 16 years and the exploration of the new direction are strongly required. To accord with these requirements, this study analyze Japan's college entrance exam, NCTUA(National Center Test for University Admissions) which is the most similar to our exams. And then on the basis of this, the applicable implication to set mathematics questions in 2012 and 2014 CSAT will be deducted.

• The Journal of Korean Association of Computer Education
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• v.19 no.6
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• pp.1-14
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• 2016

As the importance of informatics education has been accentuated all around the world, Japan is considering adopting 'informatics' as a subject in the university entrance examination from 2020. Under these circumstances, Informatics university entrance research group in Japan has annually conducted an 'informatics' nationwide mock test since 2013 to prepare for the time when 'informatics' is adopted as a subject in the university entrance exam and has accumulated the data which help understand the informatics education level of high school students and its trend. This study thus provided the Korean high school students with the questions which are the same as those from the informatics nationwide mock tests conducted in Japan so far in order to identify the education level of informatics among Korean and Japanese students. Overall mean scores and mean scores in each subject of Korean and Japanese students in the 2015 informatics nationwide mock tests were compared and analyzed and the gender analysis was conducted. These results will be expected to suggest the direction for the future informatics education such as adopting 'informatics' as a subject in the university entrance exam in order to be a compulsory subject in the high school curriculum that can ensure the required skills in society.

• Research in Mathematical Education
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• v.2 no.2
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• pp.79-88
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• 1998

To investigate the relationship between the College Entrance Examination (CEE) exams and high school teaching-learning, we conducted a questionnaire survey and collected 2439 valid questionnaires with 16000 teachers involved. This paper discusses the topic with data gathered from the survey, and statistics on CEE examinations over the past few years. The following three questions will be addressed in detail: 1. As a talent selection test for colleges, can the CEE exams single out the elite students in high school? 2. Should the testing objectives of the CEE exams match the teaching objectives in high school so as to have a positive backwash effect on high school teaching and learning? 3. How do teachers assess the CEE exams from the angles of test structure, the functions of individual item types, reforms on test difficulties, and its actual checking effects?