• Journal of Electrical Engineering and Technology
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• v.13 no.6
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• pp.2276-2283
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• 2018

A 50kW-4000rpm interior permanent magnet synchronous machine (IPMSM) applied to the high-performance electric vehicle (EV) is introduced in this paper. The main work of this paper is that a 2-D T-type lumped-parameter thermal network (LPTN) model is presented for IPMSM temperature rise calculation. Thermal conductance matrix equation is generated based on calculated thermal resistance and loss. Thus the temperature of each node is obtained by solving thermal conductance matrix. Then a 3-D liquid-solid coupling model is built to compare with the 2-D T-type LPTN model. Finally, an experimental platform is established to verify the above-mentioned methods, which obtains the measured efficiency map and current wave at rated load case and overload case. Thermocouple PTC100 is used to measure the temperature of the stator winding and iron core, and the FLUKE infrared-thermal-imager is applied to measure the surface temperature of IPMSM and controller. Test results show that the 2-D T-type LPTN model have a high accuracy to predict each part temperature.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.7
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• pp.2159-2166
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• 1996

The stochastic properties of variation in fatigue crack growth are important in reliability and stability of structures. In this study,the stochastic model for the variation of fatigue crack growth rate was proposed in consideration of nonhomogeneity of materials. For this model, experiments were ocnducted on 7075-T6 aluminum alloy under the constant stress intensity factor range. The variation of fatigue crack growth rate was expressed by random variables Z and r based on the variation of material coefficients C and m in the paris-Erodogan's equation. The distribution of fatigue life with respect to the stress intensity factor range was evaluated by the stochastic Markov chain model based on the Paris-Erdogan's equation. The merit of proposed model is that only a small number of test are required to determine this this function, and fatigue crack growth life is easily predicted at the given stress intensity factor range.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.7 s.155
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• pp.1034-1043
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• 2006

The purpose of this study was to investigate the difference of the visual evaluation about gathered skirts according to different gathering conditions and objects. The experiment is made of factorial design for three variables-fabric(cotton, wool, polyester), ratio of gathers(1.5T, 2.0T, 2.5T), objects(real thing, 2D digital picture, 3D shape). Questionnaire consists of 33 sematic differential scale expressing gathered skirts' image. The subjects were 50 male and female students majoring in clothing and textile. The data were analyzed by Frequency, Factor analysis, Anova, scheffe's test. The results obtained were summarized as follows; 1. As the open-ended response there were difference among the image according to different gathering conditions and obects. 2. The image of gathered skirts was composed of 6 factors; activities, attraction, attention, softness, moderateness, function. 3. For visual evaluation of gathering conditions as different objects, there were similar as softly in fabrics and lager in ratio of gathers. 4. For visual evaluation of different objects as gathering conditions, there was more difference effect of ratio of gathers than fabrics.

• Journal of Korean Academy of Nursing
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• v.36 no.2
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• pp.286-298
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• 2006

Purpose: This study was to develop an online 'alternative therapy and health promotion' class for university students and to evaluate its changes. Method: The online class was developed based on the Instructional Systems Development(ISD) model and model of Web-Based Instruction(WBI) developmental process. This was a quasi-experimental, one group pretest-posttest design. The subjects of this study were 130 students in 3 universities, and they were provided the cyber class for 16 weeks. Data was analyzed by descriptive and plural answer statistics, and paired t-test. Results: The cyber class was developed in five steps : analysis, design, data collection and reconstruction, programing and publishing, and evaluation. The results of program evaluation were positive, which included learning 3.47. system 3.57, and learning satisfaction 3.64 on the scale of 5. The posttest scores of cognition and reliability of alternative therapy were higher than pretest scores. The posttest score of health promoting lifestyle(t=-5.051, p=.000) and perceived health status(t=2.979, p=.003) were significantly higher than those of the pretest. Conclusion: These results suggest that the cyber class is a positive method in increasing a cognition, reliability of alternative therapy, and is effective to improve a health promotion lifestyle and perceived health status for the university students.

• International Journal of Advanced Culture Technology
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• v.8 no.3
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• pp.140-147
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• 2020

The purpose of this study is to improve the empathy, communication efficacy, and communication skills of nursing students through a psychiatric nursing practice program using storytelling by allowing the students to immerse in the narratives and identify themselves with the main characters with mental illness. This study is a single group pretest-posttest design that applied psychological nursing practice using storytelling to 46 nursing students from a local university in Korea and evaluated its effectiveness. Data analysis was performed by a paired t-test to compare the effects of the participants' empathy, communication self-efficacy, and therapeutic communication ability using SPSS 21.0 program. The results showed that psychiatric nursing practice using storytelling had an effect on the empathy (t=3.565, p=.001) and communication self-efficacy (t=2.320, p=.025) of nursing students. Based on these results, psychiatric and mental health clinical practice curriculums should be developed to improve nursing students' understanding of mental disorders and develop their communication ability with patients.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.4
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• pp.409-416
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• 2009

Standard procedures for a fracture toughness testing require very severe restrictions for the specimen geometry to eliminate a size effect on the measured properties. Therefore, the used standard fracture toughness data results in the integrity assessment being irrationally conservative. However, a realistic fracture in general structures, such as in nuclear power plants, may develop under the low constraint condition of a large scale yielding with a shallow surface crack. In this paper, cleavage fracture toughness tests have been made on side-grooved PCVN (precracked charpy V-notch) type specimens (10 by 10 by 55 mm) with various crack depths. The constraint effects on the crack depth ratios were evaluated quantitatively by the developed scaling method using the 3-D finite element method. After the fracture toughness correction from scaling model, the statistical size effects were also corrected according to the standard ASTM E 1921 procedure. The results were evaluated through a comparison with the $T_0$ of the standard CT specimen. The corrected $T_0$ for all of the PCVN specimens showed a good agreement to within $5.4^{\circ}C$ regardless of the crack depth, while the averaged PCVN $T_0$ was $13.4^{\circ}C$ higher than the real CT test results.

• Journal of the Korean Society of Earth Science Education
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• v.6 no.3
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• pp.207-220
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• 2013

The aim of this study was to find out the effect of instruction with storytelling on the achievement, attitude and interest in science. For this study, two classes were divided into experimental class and comparative class. All the results were analyzed quantitatively. Results of this study can be described as follows. First, the experimental class didn't have a significant difference in scholastic achievement compared with the comparative class. However, the results of the t-test for the academic achievement due to achievement level showed a positive effect in the average level of students. And experimental group was statistically significantly higher in the section of 'Combustion and Extinguishment' than that of the other group. Second, There was a significant difference in the aspect of the effect of instruction with storytelling on the student's science-related attitudes. As a result of analysis by sub categories of science-related attitudes, storytelling was effective in attitude toward science, but no significant differences were found in scientific attitude. Third, instruction with storytelling didn't show a meaningful difference in scientific interest. However, in the sub-part, they showed a meaningful improvement in attention and satisfaction.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.21 no.4
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• pp.466-474
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• 2014

Purpose: The purpose of this study was to identify the relationship between emotional intelligence and stress coping of nurses in hospitals. Method: The study was a descriptive-correlational study with a convenience sample of 298 nurses. Descriptive statistics t-test, Mann-Whitney U, One-way ANOVA and Pearson correlation coefficients were used for data analysis. Results: The results of this study were as follows; Emotional intelligence was higher in married nurses than unmarried nurses (t=-2.90, p=.004). Nurses with a clinical career of 4~7 years had better stress coping than nurses with shorter careers (F=5.60, p=.004). Ward nurses better stress coping than nurses in emergency rooms and Intensive care units (F=4.43, p=.013). Fixed shift nurses had better stress coping than nurses on rotation shifts (t=-2.37, p=.019). There was a significant positive correlation between emotional intelligence and stress coping(r=.29, p<.001). Conclusion: The results indicate that stress coping is better in nurses with higher emotional intelligence, 4~7 year clinical experience, working on ward a as well as having a fixed shift. However further development and application of programs which can improve nurses' emotional intelligence are needed.

• Anxiety and mood
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• v.6 no.2
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• pp.115-118
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• 2010

Objective : The purpose of this study was to survey the degree to which people use the Internet prior to joining the army and mental health. Methods : The author assessed Internet addiction and mental health using an Internet addiction diagnostic scale for soldiers and the Symptoms Check-list-90. A total of 508 subjects were included in the final analysis. Collected data were analyzed by independent t-test. Results : The Internet addiction risk group (n=19, 3.7%) had significantly higher mean scores for obsessive-compulsion (t=-2.43, p=0.02) and interpersonal-sensitivity subscales (t=-2.30, p=0.03) than the control group. Conclusion : Internet addiction was related to soldiers' mental health. An assessment focused on internet use would be useful in the evaluation of a person potential adaptation to the military.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.41.2-41.2
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• 2010

In this work, HAp-(t-ZrO2) ceramic composites of biomimic artificial bone were fabricated by multi-extrusion process in order to replace nature bone. HAp-(t-ZrO2) and graphite powders were mixed separately with ethylene vinyl acetate (EVA) and stearic acid using shear mixer. Extruded HAp-(t-ZrO2) filaments and carbon filaments were arranged in the die to fabricate the first pass filament. The first pass filaments were arranged in the same die with a central carbon core for making the space for spongy bone. Burning out and sintering processes were performed to remove the binder and lubricant. The microstructure channel diameter was researched around $300{\mu}m$. Microstructure analysis was carried out by OM, SEM, and $\mu$-CT. Compressive strength was investigated for the artificial bone. Some preliminary bio-compatibility test was evaluated.