• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.386-391
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• 2021

Turbocharging is becoming a key technology for both diesel and gasoline engines. Regarding gasoline engines, turbocharging can help reduce carbon dioxide (CO2) emissions when used in conjunction with other technologies. This paper presents measurements of the turbine efficiency of pulsating flow in a twin-scroll turbocharger for gasoline engines. A cold gas test bench with a pulse generator was manufactured. The turbine efficiencies were calculated using the measured data of the instantaneous pressure and temperature of the inlet and exit of the turbine. The measurements were carried out at turbine speeds from 60,000 to 100,000 rpm under a pulsating flow of 25.0 Hz and 33.0 Hz. The turbine efficiencies ranged from 0.517 to 0.544. At the pulse frequency, 33.3 Hz, the variations in efficiency were 7.7% and 2.6% at turbine speeds of 60,000 rpm and 100,000 rpm, respectively. The turbine efficiency of the pulsating flow compared to those of steady flow was 7.0% and 3.0% lower at a turbine speed of 60,000 rpm and 100,000 rpm, respectively. The pulsating flow deteriorated the turbine efficiency, but the effects of pulsating flow decreased with increasing turbine speed.

• The Journal of the Korea Contents Association
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• v.11 no.6
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• pp.289-301
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• 2011

This study is a research based on the non-equivalent control group pretest-posttest design whose purpose is to examine the effects of music therapy on the anxiety of patients who take the magnetic resonance imaging(MRI) test and their feeling of discomfort during the test. "The first hypothesis that the experimental group who receive music therapy will be lower in score for anxiety during the MRI test than the control group who do not was supported because after the therapy, the experimental group was found significantly decreased in that score in comparison to the control group. "The second hypothesis that the experimental group who receive music therapy will be fewer in vital signs after the MRI test than the control group who do not" was rejected in terms of both systolic and diastolic blood pressure. But the same hypothesis was partially supported because the two groups showed a significant difference in pulse rate after the test. "The third hypothesis that the experimental group who receive music therapy will be less in the feeling of subjective discomfort during the MRI test than the control group who do not" was verified to find that the two groups were significantly different from each other in the feeling. Specifically, there was a significant difference between the two groups in only one sub-area of that feeling, that is, tension. These findings suggest that music therapy could be an alternative method which can effectively reduce the state anxiety of patients during the magnetic resonace imaging(MRI) test.

• Journal of the Microelectronics and Packaging Society
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• v.16 no.1
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• pp.33-38
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• 2009

The use of portable devices has created the need for new reliability criterion of drop impact tests because of the tendency to accidentally drop in the use of these devices. The effects of different PCB surface finishes (organic solderability preservative (OSP) and electroless nickel immersion gold (ENIG)) and high temperature storage (HTS) test on the drop reliability were studied. Various drop test conditions were used to evaluate a drop reliability of assemblies to endure such impact and shock load. In the case of the as-reflowed samples (no HTS test), the SAC/OSP boards exhibited a better drop impact reliability than that of SAC/ENIG. However, the reverse was true if HTS test is performed. In addition, significant decrease of drop reliability was observed for both SAC/ENIG and SAC/OSP assemblies after HTS test. It was also observed that the thickness of intermetallic compound layer do play an important role in the brittle fracture of drop test.

• Journal of Korean Clinical Nursing Research
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• v.22 no.3
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• pp.249-256
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• 2016

Purpose: The purpose of this study was to examine the effect of leg raising and peripheral excercise on recovery of the patients who were applied with dexmedetomidine for their dental surgery. Methods: There were two groups, the experimental group (n=35) and control group (n=35), in this study. We checked blood pressure, pulse rate, oxygen saturation, sedation level and symptoms such as dizziness and somnolence every 30 minutes. These parameters were assessed throughout the participants' recovery room stay. Leg raising and peripheral excercise were conducted in the experimental group in the recovery room. We have conducted chi-square test, Fisher's exact test, t-test, ANOVA, and ANCOVA to compare the measured parameters in both groups. Results: The experimental group showed a significant elevation of mean arterial blood pressure, and mitigation of somnolence, sedation and dizziness compared to the control group. Conclusion: Leg raising and peripheral exercise is effective to expedite recovery in the patients who were applied with dexmedetomidine for their dental surgery.

• Journal of Auto-vehicle Safety Association
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• v.4 no.2
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• pp.37-43
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• 2012

The purpose of this research is to obtain and analyze dynamic responses from human volunteers for the development of the human-like mechanical or mathematical model for Korean males in automotive rear collisions. This paper focused on the introduction to a low-speed rear impact sled test involving Korean male subjects, and the accumulation of the motion of head and neck. A total of 50 dynamic rear impact sled tests were performed with 50 human volunteers, who are 30-50 year-old males. Each subject can be involved in only one case to prevent any injury in which he was exposed to the impulse that was equivalent to a low-speed rear-end collision of cars at 5-8 km/h for change of velocity, so called, ${\Delta}V$. All subjects were examined by an orthopedist to qualify for the test through the medical check-up of their necks and low backs prior to the test. The impact device is the pendulum type, tuned to simulate the crash pulse of a real vehicle. All motions and impulses were captured and measured by motion capture systems and pressure sensors on the seat. Dynamic responses of head and T1 were analyzed in two cases(5 km/h, 8 km/h) to compare with the results in the previous studies. After the experiments, human subjects were examined to check up any change in the post medical analysis. As a result, there was no change in MRI and no injury reported. Six subjects experienced a minor stiffness on their back for no more than 2 days and got back to normal without any medical treatment.

• Journal of Acupuncture Research
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• v.28 no.2
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• pp.155-164
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• 2011

Objectives : The purpose of this study was to show the corelation between age-related muscular mass and the change of exercise, muscle mass and muscular strength by comparison of muscle strength. Methods : 39 volunteers of all the patients who come to Dangjin health center between May and June in 2009 were classified as group A and group B according to age. Demographic data of these two groups have been done a comparative analysis, using the t-test procedure and linear regression analysis. Results : The results and summarized as follows. 1. Demographic data of these two groups have been done a comparative analysis, using the t-test procedure. As a result the average exercise and the average pulse have a statistically significant difference according to age. 2. Each of average fat, muscle and muscular strength in these two groups have been done a omparative analysis, using the t-test procedure. As a result there is no statistically significant according to age. 3. According to the result analyzed by using linear regression analysis, age have a negative effect on muscle but there is no statistically meaningful. Exercising have a positive effect on muscle and there is statistically significant. 4. Age and Protein diet have a negative effect on Grip strength but there is no statistically significant Conclusions : From this result, it can be assumed that the amount of exercise is decreasing with age, which leads to lose some muscle mass.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.6
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• pp.1405-1410
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• 2015

In this study we designed the radiation-hardened sensor signal processing modules that can be commonly used for a variety of sensors during normal operation and even in high-radiation environments caused by an accident. First development module was designed to receive the change of the R and C value from the sensors and to process the signal as a PWM modulation scheme. This module was assessed to have ± 10% error to the Full-Scale in the radiation test in the range of 12 kGy TID. The main cause of the error was analyzed as the annealing of the common circuit in the switching element and the consequent increase in the duty ratio of the pulse width modulation circuit according to the radiation dose increasement. The redesigned module for higher radiation resistivity with Stub transistor circuit was found to have less than 5% error to the Full-scale from the radiation test results for 20.7 kGy TID range.

• The Journal of Korean Academic Society of Nursing Education
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• v.5 no.1
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• pp.20-38
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• 1999

This study is conducted to test an effect of the guided Imagery program on artificially induced pain and to develop an effective nursing intervention for patients with pain. The subjects of this study were 37 normal female university students. The data were collected from September 1998 to December 1998. And two group non-equal quasi -experimental research with pre and post design was used in this study, The data were analyzed with the SPSS $PC^+$ program with percentage, t-test, paired t-test and ANCOVA. The results of this study were as follows : 1. There are no significant differences of systolic blood pressure between groups. 2. The experimental group showed significantly lower diastolic blood pressure than control group after treatment. 3. There are no significant differences of pulse rate between groups. 4. The experimental group showed significantly higher body temperature than control group after treatment. 5. There are no significant differences of pain intensity between groups. 6. There are no significant differences of pain sensation between groups. 7. There are no significant differences of perceived pain tolerance time between groups. 8. The experimental group showed significantly longer real pain tolerance time than control group after treatment. 9. There are no significant differences of anxiety scores between groups. 10. There are no significant differences of Self-esteem scores between groups. 11. There are no significant differences of Self-esteem scores between groups. 12. There are no significant differences of imagability scores between groups. 13. The post-experimental group showed significantly higher relaxation rate than pre -experimental group. 14. There are no significant differences of imaging depth degree between pre-experimental group and post-experimental group. From the above results, it can be concluded that 1. This guided imagery program could be recommenced as an effective nursing intervention to relieve pain. 2. A follow up study is needed to identify long-term effects.

• Korean Journal of Adult Nursing
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• v.13 no.4
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• pp.632-640
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• 2001

Purpose: This study was to examine the effects of supportive nursing care on surgical patients in the operating room. Method: This study was nonequivalent control group none-synchronized design. The data were collected during the period of July 26 through October 8, 1999 at K hospital in Kwangju. The subjects for the study were selected from those patients who were admitted to K hospital for abdominal surgery. Forty-eight adult subjects were selected and evenly divided into two groups: 24 for the experimental group and the other 24 for the control group, respectively. The tool used for measuring state and trait anxiety was the one originally worked out by Spilberger(1976), and translated by Kim Jung- Taek and Shin Dong-Kyun(1978) for suitable application for Koreans. Data were analyzed by $\chi^2$- test, t-test, Chronbach's ${\alpha}$ coefficient using SAS/PC+. Result: Results were as follows : 1. The degree of State anxiety was found to be lower in the experimental group who received supportive nursing care in the operating room immediately before an operation than the control group who did not."(p<.001). 2. There was no significant difference on the post-test blood pressure and pulse rate immediately before operation between the two groups(p>.05). Conclusion: Results of the above study reveals that the supportive nursing care in the operating room is effective in alleviating the anxiety of patients. I suggest that it is highly desirable to apply supportive nursing care for those patients who are waiting for immediate surgery.

• Korean Journal of Adult Nursing
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• v.16 no.1
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• pp.146-155
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• 2004

Purpose: The Purpose of this study was to explain the effects of aromatherapy massage on the preoperative anxiety of hemorrhoidectomy patients, and to provide the effective and holistic nursing care to them. Method: The research design was a nonequivalent control group non-synchronized design. The data were collected during the period from November 1 to November 30, 2003 at K-Hospital in Seoul. The subjects were fifty patients who were to have a hemorrhoidectomy under general anesthesia. They were assigned to two groups, 25 subjects to the experimental group and 25 subjects to the control group. The State Anxiety Inventory tool was used to measure state-anxiety on all patients the day before surgery. Systolic and diastolic blood pressure, and pulse rate were measured on the day before surgery and the preoperative period. The experimental group received aromatherapy massage on the hand with lavender oil. Data were analyzed by $x^2$ test, independent t-test, paired t-test. Result: 1. Hypothesis 1, that the level of preoperative state-anxiety of the experimental group who received aromatherapy massage would be lower than that of the control group who did not received aromatherapy was supported(p=.047). 2. Hypothesis 2was that the Physiological index of the preoperative anxiety of the experimental group who received aromatherapy would be lower than that of the control group who did not received aromatherapy. The 1st subhypothesis that "the level of the preoperative systolic and diastolic blood pressure of the experimental group would be less than that of the control group" was not supported. Conclusion: Aromatherapy massage can be regarded as a partially effective nursing intervention that relives the preoperative anxiety of surgical patients and stabilizes vital signs.