• Steel and Composite Structures
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• v.38 no.1
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• pp.79-86
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• 2021

Due to the complex geological conditions, a large number of high quality coal seams was buried in the western of China which cannot be mining in open-pit methods. The dynamic properties of that coal cannot be studied easily in real site for the complex working condition. The compound coal blocks made on the basis of the real situation were studied in the laboratory. The physical and mechanical properties of the compound coal blocks and the raw coal were contrasted by using the UCS tests. The results show that the compound coal blocks made by mixing coal powder, cement and water in proportion of 2.5:2:1 are the closest to that of standard raw coal. Then the propagation of strain waves and crushing effects on the coal were studied in the compound coal blocks by using the super dynamic strain test system and the numerical calculated method of ANSYS/LS-DYNA. The results show that the diameter of the crushing zone in the compound coal blocks was similar to that in the numerical results. The fractures distribution in laboratory tests also has a similar trend to the calculation results. The measured strain waves at the distance of 50 cm, 100 cm, and 150 cm from the center of the charge are mainly concerned at -1.0×104 με and have a similar trend as that in the numerical simulation.

• The Journal of Korean Medicine
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• v.42 no.3
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• pp.86-98
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• 2021

Objectives: This study aims to evaluate the impact of patient-physician communication curriculum on students of Korean medical school in terms of cognitive, affective, and psychomotor level of communication skills. Methods: A communication curriculum was developed considering COVID-19 pandemic situation. Lectures, peer role-play, open interview with standardized patient (SP), discussion and feedback were conducted by online, and face-to-face 1:1 SP-interview was performed. Scores of written test, peer role-play of medical communication, SP-interview, self-evaluation on one's interview with real patients in clinical clerkship, and questionnaire of importance were collected and analyzed. Results: Converted to 100 point scale, the mean score of written test (cognitive level) was 91.2 while that of importance questionnaire (affective level) was 77.5. The mean scores of psychomotor level were 72.5, 77.5, and 62.5 for peer role-play, SP-interview, and real patient interview in clerkship, respectively. Conclusions: Students' performance is lower in higher level of competence. Curriculums should provide more opportunities of practices to students, and include evaluation focusing on performance skills.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.3
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• pp.379-385
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• 2012

This paper developes the navigation visual aid supporting a watch officer's situation awareness and analyzes its performance test result. Developing the equipment made from composite video sensor which transfer video signal, ranger laser measurement model which search out distance, Pan/ Tilt, center control device. The developed equipment with Pan/Tilt was made from high performance video sensor and ranger laser measurement. To make a real ship test, we carried on setting the developed equipment on ship, observed a danger factor and analyzed a image, and from that we can evaluate marine environment awareness. Through this result, the developed equipment can show effective ability of the awareness of the clearer check and resolution situation when compare with the binocular.

• Tunnel and Underground Space
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• v.8 no.2
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• pp.107-117
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• 1998

In the case of a fire disaster in a uni-directional road tunnel, it is important to determine the critical ventilation velocity to prevent the backflow travelling toward the tunnel exit where vehicles are stopped. The critical ventilation velocity is horizontal velocity to prevent hot smoke from moving toward the tunnel exit. According to Froude modelling, the model tunnel whcih was 300mm in diameter and 21 m in length was made of acryl tubes. Inner section of acryl tubes was clothed with polycarbonate. 1/20 scaled model vehicles were installed to simulate the situation that vehicles are stopped in the tunnel exit. Methanol in a pool type burner was burned in the middle of tunnel to simulate a fire hazard. In this study, the basis of determining the critical ventilation velocity is the ventilation flow rate that is able to maintain the allowable CO concentration in the tunnel section. We assumed that the allowable CO concentration was backflow dispersion index. Futhermore, We intended to find out CO distribution and temperature distribution according as we changed ventilation velocity. The results of this study were that no backflow happened when ventilation velocity was 0.52 m/s in the case of 5.75 kW. If we adapt these results of a fire disaster releasing 10MW heat capacity in real tunnel which is 400m in length, no backflow happens when ventilation velocity is 2.31m/s. After we figured out dimensionless heat release rate and dimensionless ventilation velocity of model test and those of real test to verify experimental correctness, we tried to find out correlation between experimental results of model tunnel and those of real tunnel.

• Korean Journal of Human Ecology
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• v.12 no.5
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• pp.619-634
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• 2003

The purpose of this study was to the real situation of the safety education in the kindergarten by investigating the actual condition of the safety education and kindergarten teachers' knowledge about it. Questionnaire was adopted to obtain data required for pertinent analysis. The subjects were 234 kindergarten teachers located in Choongnam and Daejeon province. SPSSWIN v10.0 was utilized to calculate percentage, mean and standard deviation and to conduct t-test, one-way ANOVA and Duncan's multiple range test. The main results of this study were as follows. There was a significant difference between the actual condition of the safety education and kindergarten teachers' knowledge about it according to demographic variables. Especially, these differences were due to teachers' academic career, age, teaching experience, and the experience of bringing up children by themselves. The importance of the safety education must be emphasized. There were urgent needs to develop the way of teaching and the program about the safety education.

• Journal of Korea Multimedia Society
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• v.16 no.12
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• pp.1446-1453
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• 2013

In order to develop ECM system, there are a number of methodologies. Adopting Microsoft's solution and methodology is one of them. ECM has a large number of users to save the documentations in various types of multimedia data. So, managing multimedia database is very critical in ECM. Therefore the unit and integration test to evaluate the performance can detect the flaws of the system early on, and it has to be enables to reflect the user's requirements thru the user acceptance test. In this paper, we are discussing how to optimize the SQL database before the ECM system is built and used in the real situation thru unit and integration tests.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.29-32
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• 2006

The techniques related to ultra-high strength concrete(UHSC) became the key issue in recent days since requirements of the high-rise building which story is over than 100 gradually increases. Therefore, for the development of 150MPa UHSC this research is generally categorized by 4 parts: development of pre-mixed binders, evaluation for the fire performance of coarse aggregate, optimization of the mixture proportion, and mock-up test. Finally, based on the optimized mixture and its laboratory tests, mock-up test for wall and column specimens were carried out to simulate and evaluate the UHSC in real situation. The mechanical properties of core specimens were compared with the cylinder specimens made in laboratory. For instance, it showed the reasonable the results that the strength at the age of 91 days is 183MPa.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.6
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• pp.910-915
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• 2012

In this paper we propose multi-grounded neutral design method which was considered of transferred transient overvoltage when line to neutral fault occurs. Specially, In order to confirm the actual transient overvoltage magnitude which occurs on neutral line, we considered some screening(shielding) effects. The screening coefficient was deducted from field test results and calculation in a distribution line which is identical with an actual power line. The purpose of this paper is to attempt to suggest the guidance for grounding skystem design considering limitation of overvoltage for LV side in IEC 61936. The result is based on EMTP simulation and real field faults situation in distribution lines.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.1
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• pp.15-21
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• 2013

The safety and stability of 5MW class offshore wind turbine Jack-up platform was investigated through ocean basin experiment. For simulating the environmental condition of yellow sea in the South Korea, diverse waves, winds and currents were performed based on Froude's number. Regular wave and irregular wave based on Froude's number were applied to the wind turbine structure. In experiments, the height and period of regular wave type were scaled down as the 1:50 ratio of real wave condition. Irregular wave type was simulated with TMA(Texel Storm, Marsen and Arsloe)spectrum. The vertical reaction force, resonance period and wave pressure applied to multi-supporters of wind offshore structure were measured experimentally. Finally, the results showed that the capsizing situation of the offshore structure was generated by the severe environmental condition.

• The Research Journal of the Costume Culture
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• v.6 no.1
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• pp.94-109
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• 1998

The objective of this study is to measure self-image of adolescence, analyze empirically clothing-purchasing-behavior of adolescence and clarify correlation of two variables, self-image and clothing-purchasing-behavior. For this purpose, the techniques involve theoretical studies and researches based on historical obtained from previous related studies and surveys, 431 high school female students who reside in Seoul are asked to answer selected survey questions to examine three aspects, clothing-purchasing-behavior, self-image and demographics. The evaluation of surveyed information is analyzed by statistical techniques to improve the accuracy of data. Statistical methods used are as follows; Descriptive(frequency, mean, percentage), Factor Analysis(varimax rotation), Crosstabs(Chi-square), T-test, One-Way ANOVA< Correlation Analysis, Reliability Analysis and Duncan's Multiple Range Test. The mjor results of this study were as follows: Firstly, there is a discrepancy between real self-image and ideal self-image. Furthermore more significant differences is seen from physical aspects than psychological aspects. Consequently, research proves that the difference derived from their ideal situation and real situation leads to psychological unstableness. In addition, making their real self-image is dependent upon several elements such things as family economic level, pocket money, expenditure on clothing. Therefore, it is critical to combine all factors in order to decide how much to spend for children's clothing and pocket money in parents point of view. Secondly, research shows that shows hat there is correlated relationship between average expenditure on clothing and presence of mother's job. Average expenditure on clothing is, generally, influenced by vogue which is tend to be changed seasonally. It, also, shows that there is positive linear regression between expenditure on clothe and sensitivity for vogue. That is to say, dependent variable, expenditure on clothing, is varied as independent variable, sensitivity for vogue, changes. Female high school students are likely to give much value on brand. Moreover people who are spending more money on clothes have higher tendencies in prompt purchases than who are not. Thirdly, the analysis of clothing-purchasing-behavior and self-image shows that the difference between real self-image and ideal self-image draws the main reason of dissatisfaction after purchase of clothes. As a consequence, their unfilled needs lead them to keep making another purchase to satisfy themselves. Therefore, it is strongly recommended that parents' advices and directions on their children's money spending on clothes are imperative to establish well-behaved purchasing patterns.