• Journal of KSNVE
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• v.9 no.2
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• pp.285-294
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• 1999

Transient analysis for compressible fluid flow has been performed experimentally and analytically to study the dynamic characteristics of the end volume transmission lines following a sudden pressure change a its entrance. The numerical method was developed based on the method of characteristics. The sudden pressure at its entrance was generated by rupture of diaphragm in a shock tube. The sudden pressure was used to obtain the response, as input signal for the numerical analysis. The response to the sudden pressure at the end volume was measured using a pressure transducer. The experimental result shows good agreements with the numerical result. The effects of tube length, its diameter and end volume magnitude are evaluated on the responses of the pressure and on the damping factor. It is found that the viscous damping effects on the response through the transmission pipeline becomes larger with increasing pi;eline length and decreasing diameter of the pipe and the fluid-elastic stiffness decreases with increasing the terminal volume. The numerical approach presented in this paper can be very useful in designing the instrument and control system.

• Progress in Superconductivity and Cryogenics
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• v.12 no.1
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• pp.17-21
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• 2010

In the case of designing superconducting power apparatuses using the second generation high temperature superconducting wire, it is necessary to have a tape-splicing technique to achieve low splice resistance between coated conductor (CC) tapes. In this paper, an experimental splice method between YBCO CC tapes is proposed for a coil application. Splices were performed with a 37Pb-63Sn solder. YBCO samples were fabricated with various pressures and cooling rates. Joint resistances of the spliced samples of jointed YBCO CC tapes were measured and evaluated from V-I curves. In addition, optical micrographs were obtained to analyze the cross sectional microstructure of jointed samples.

• The Journal of Korean Academic Society of Nursing Education
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• v.29 no.4
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• pp.352-361
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• 2023

Purpose: The purpose of this study was to construct the education applying the Havruta method for nursing students and to investigate the effects on self-directed learning ability, critical thinking, and learning commitment. Methods: A nonequivalent control group pre-posttest design was used. The participants were 63 nursing students (experimental group, n=31; control group, n=32) at two universities. The experimental group received education applying the Havruta method for five weeks. The study was conducted from September 1 to November 30, 2022. The data were analyzed using IBM SPSS 27.0 for an χ² test, Fisher's exact test, independent t-test, and Mann-Whitney U-test. Results: The experimental group had a significant increase in self-directed learning ability (z=-2.13, p=.033). However, there was no significant difference in critical thinking competency (t=0.64, p=.524) and learning commitment (t=0.04, p=.969) between the two groups. Conclusion: The Havruta method is an effective nursing education tool for self-directed learning ability. The result of this study could be a guide for nursing professors in designing and implementing educational programs that apply the Havruta method. In the future, research that applies the Havruta method and evaluates its effectiveness in nursing education programs should be continued.

• Journal of Science Education
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• v.39 no.3
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• pp.376-388
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• 2015

The purpose of this study was to develop the experiment-based problem for evaluating scientific ability of elementary scientifically gifted students, and to examine its potential of application for them. The problem for evaluating scientific ability was related to the plant vascular structure of 'the structure and function of plants' unit of elementary school science, and consisted of three components such as observing and inferring, designing an experiment, and concluding. In order to apply for scientifically gifted students, scoring criteria were detailed. For the observing and inferring domain, the arrangement and structure of vascular bundles of the dicotyledon and the monocotyledon, xylem position, reason of putting plants in ink were included. Those of designing an experiment domain were method of dissecting stems of plants, and design experimental procedures, those of concluding were the prediction of experimental results, and comparison and verification with prediction and results. Finally, the scientific ability evaluation problem was applied for 22 scientifically gifted students, who had been taught in the Science Education Institute for the Gifted adjacent University, and we had found the potential of utilization for scientifically gifted students.

• Fisheries and Aquatic Sciences
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• v.3 no.1
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• pp.64-70
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• 2000

DNA probes for the l6S rRNA have been designed for the detection of Edwardsiella tarda. In order to accomplish this purpose, the l6S rRNA gene from E. tarda has been cloned and sequenced. Two highly feasible oligonucleotide probe sites have been determined by the database analysis programs presented by PCGENE and BLAST. These two probes have been evaluated by slot blot hybridization analysis. Hetero- and homo-trimeric templates have been synthesized using these two probe sites. The templates have been further multimerized by PCR to generate between 150 and 300 bp long DIG-11-dUTP labeled probes. Unlike 3' end labeled oligonucleotide probes or templates, multimerized probes showed no cross­hybridization in the given experimental condition. Furthermore, a significant increase in sensitivity has been observed with these probes. This method, we presented here, may be useful for the designing of probes for the detection of other fish pathogenic microorganisms also.

• Progress in Superconductivity and Cryogenics
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• v.14 no.2
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• pp.28-31
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• 2012

The study on the dielectric characteristics of gaseous insulation medium is important for designing current leads of superconducting machines using a sub-cooled liquid nitrogen ($LN_2$) cooling method. In a sub-cooled $LN_2$ cooling system, the temperature of gaseous insulation medium surrounding current leads varies from the temperature of coolant to 300 K according to the displacement between the electrode system and the surface of sub-cooled $LN_2$. In this paper, AC withstand voltage experiments on gaseous nitrogen according to temperature are conducted. Also, AC withstand voltage experiments on gaseous nitrogen according to pressure, size of electrode, and gap length between two electrodes are performed. It is found that there is a functional relation between the electrical breakdown voltage and the field utilization factor (${\xi}$). As a result, the empirical formula for estimating an electrical breakdown voltage is deduced by adopting the concept of field utilization factors. It is expected that the experimental results presented in this paper are helpful to design current leads for a high voltage superconducting apparatus such as a superconducting fault current limiter (SFCL) using a sub-cooled $LN_2$ cooling system.

• The Journal of Korean Academic Society of Nursing Education
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• v.17 no.3
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• pp.433-443
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• 2011

Purpose: This study aimed at (a) developing an instructional model of creative thinking education on the problem-based learning method (C-PBL) in undergraduate nursing curriculum at one University, and (b) examining its effect on nursing students' level of creativity and outcomes from problem-based learning. Methods: The C-PBL model was implemented on 43 juniors of the experimental group with a 30 hour-nursing class during one semester. The control group, with 54 seniors, received 4 hours of problem based learning training in an adult nursing class. Pre-and post-tests were done with the Torrance Tests of Creative Thinking for creative thinking ability, the Integrated Creativity Instrument for creative motivation and attitudes, the Problem Solving Competency questionnaire, and the Self-Directed Learning Instrument. Results: The C-PBL model was developed using a caring situation scenario to solve nursing problems with 3 training steps of 'encountering a patient in a caring situation', 'exploring nursing knowledge', and 'designing creative caring beyond given knowledge'. Between the experimental group and the control group, there were significant differences in creativity (p<.010), problem-solving ability (p<.010), and self-directed ability (p<.010). Conclusion: This C-PBL method could contribute in increasing creative competency as well as problem-solving ability for nursing students.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.5
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• pp.82-92
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• 1996

A computer simulation with predict the fuel injection rates and the fuel injection pressure behaviors in diesel engine fuel injection systems would by very useful in designing or improving fuel injection systems. In this paper we developed computer program in order to predict the behaviors of the fuel injection rate and the injection pressure for Electronic Hydraulic Ultra-High Pressure Fuel Injection System. We've applied the continuity and momentum equations for the hydraulic phenomena and the dynamics of individual components of the Electronic Hydraulic Fuel Injection System. To solve all the equations numerically we've applied the Runge-kutta IV method. Water hammer equations were applied for the hydraulic pipe solution, and the method of characteristics was employed in our calculations. The simulation results were compared with the experimental results for: Accumulator pressure, Injection pressure and unjection rate. As a result, The simulation results agree very well with our experimental results. We found that a large accumulator and the high speed solenoid valve were required, and the compression volume of the fuel had to be as small as possible in order to acheive ultra-high pressure fuel injection.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.1
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• pp.39-46
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• 1999

Disturbances acting on the track-following servo system of an optical disk drive inherently contain significant periodic components that cause tracking errors of a periodic nature. Such disturbances can be effectively rejected by employing a repetitive controller, which must be implemented carefully in consideration of system stability. Plant uncertainty makes it difficult to design a repetitive controller that will improve tracking performance yet preserve system stability. In this paper, we examine the problem of designing a repetitive controller for an optical disk drive track-following servo system with uncertain plant coefficients. We propose a graphical design technique based on the frequency domain analysis of linear interval systems. This design method results in a repetitive controller that will maintain system stability against all admissible plant uncertainties. We show simulation and experimental results to verify the validity of the proposed design method.

• Journal of Korea Multimedia Society
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• v.19 no.10
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• pp.1747-1758
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• 2016

In this paper, we propose a new fast Hough transform to improve the processing time and line detection of Hough transform that is widely used in various vision systems. First, for the fast processing time, we reduce the number of features by using multi-statistical methods and also reduce the dimension of angle through six separate directions. Next, for improving the line detection, we effectively detect the lines of various directions by designing the line detection method which detects line in proportion to the number of features in six separate directions. The proposed method was evaluated with previous methods and obtained the excellent results. The processing time was improved in about 20% to 50% and line detection was performed better in various directions than conventional methods with experimental images.