• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2008년도 추계학술대회 논문집
• /
• pp.263-266
• /
• 2008

This paper is concerned with the analysis of elasto-plastic stress waves in a mode I semi-infinite cracked solid subjected to Heaviside pulse load. This study adopts a time-discontinuous variational integrator based on Hamiltonian in order to reduce the numerical dispersive and dissipative errors. This also utilizes an integration scheme of the constitutive model with 2nd-order accuracy which is formulated on the strain space for a rate and temperature dependent material model. Finite element analyses of elasto-plastic stress waves are carried out in order to compare the accuracy between a conventional Galerkin method and the time- discontinuous variational integrator.

• 한국산학기술학회논문지
• /
• 제9권1호
• /
• pp.246-256
• /
• 2008

본 연구는 아로마 등마사지가 스트레스에 미치는 영향을 알아보기 위해, 성인 여성 30명을 대상으로 혼합 아로마오일(제라니움, 로즈마리, 마조람)을 사용하여 20분간의 등마사지를 주 1회씩 총 10회를 실시하였다. 결과로 신체적, 심리적 스트레스가 감소하였으며, 혈압과 맥박수가 감소하여 아로마 등마사지가 스트레스 감소에 효과가 있었다.

• 지역사회간호학회지
• /
• 제6권1호
• /
• pp.98-113
• /
• 1995

The purpose of this study were two fold : first, to determine the effect of aerobic exercise on BP, pulse rate, body fat, body weight, symptoms of sterss response: and secondly, to apply the aerobic exercise on nursing practice in the healthy or ill subjects. In an attempt to investigate the physiological and psychological effect of exercise, a quasi -experiment, non-equivalent control group pre-test & post-test design was planned. Experiments were carried out from July 4, through August 30, 1994 with 37 subjects conveniently sampled from K & Y sports center located in Taejon. The 37 research subjects were assigned to experimental(16 subjects) and control(21 subjects) groups. Aerobic exercise was carried out for experimental group from three times to five times a week for 6 weeks in aerobic center. Data were analyzed with t-test, mean, per centage of change using SAS program. Results were obtained as follows: 1) Systolic blood pressure (M=123.75mmHg, % of change=1.12%) and diastolic blood pressure (M=74.38mmHg, % of change=5.79%) was increased on that of experimental group after 6 weeks experiment. But there was no significant difference between experimental group and control group. 2) Body weight was decreased on that of experimental group(M=56.54Kg, % of change=-1.60%) and that of control group(M=52.05, % of change=-0.99%) after 6 weeks. But there was no significant difference between experimental group and control group. 3) Body fat was decreased on that of experimental group(M=30.53%, % of change=-3.60%) and that of control group (M=28.75%, % of change=-3.52%) after 6 weeks. There was no significant difference between experimental group and control group. 4) Pulse rate was decreased on that of experimental group(M=69.19회/min, % of change -8.43%) and that of control group(M=76.0회/min, % change -0.07%) after 6weeks. There was significant difference(t=-2.621, P<0.05) between experimental group and control group. 5) Symptoms of stress response were decreased on that of experimental group(M=0.97) and that of control group(M=1.15) after 6 weeks. There was no significant difference between experimental group and control group. Therefore, adherence to aerobic exercise for 6 week seem to be affected mainly pulse rate of subjects. A futher study is necessary to determine the difference in the effect of variety exercise, programs, to study over 6 weeks, to produce professional educational program for exercise speciality nurses.

• 동서간호학연구지
• /
• 제16권2호
• /
• pp.190-198
• /
• 2010

Purpose: The purpose of this study was to evaluate the effects of a combination program of meridian massage and foot reflexology on stress and natural killer (NK) cell activity in adults. Methods: This study is a quasi-experimental research usingone-group-pretest-posttest design. The subjects of the study were 42 adults in T city. Stress level was assessed with systolic blood pressure, diastolic blood pressure, pulse rate, and serum cortisol level. The data were analyzed by SPSS/WIN 17.0 program with descriptive statistics and Wilcoxon signed-rank test. The period of this study was from January 4 to July 11 of 2008. The program was performed three days per week, two hours per session. Results: The degrees of perceived stress were significantly different while objective stress levels were partially different between pre-and post-program. The NK cell activity did not show a significant difference between before and after the program. Conclusion: This study suggests that combination of meridian massage and foot reflexology may be an optional nursing intervention to reduce subjective and objective stress in adults.

• ETRI Journal
• /
• 제39권2호
• /
• pp.292-299
• /
• 2017

We propose pulse-mode dynamic $R_on$ measurement as a method for analyzing the effect of stress on large-scale high-power AlGaN/GaN HFETs. The measurements were carried out under the soft-switching condition (zero-voltage switching) and aimed to minimize the self-heating problem that exists with the conventional hard-switching measurement. The dynamic $R_on$ of the fabricated AlGaN/GaN MIS-HFETs was measured under different stabilization time conditions. To do so, the drain-gate bias is set to zero after applying the off-state stress. As the stabilization time increased from $ 0.1{\mu}s$ to 100 ms, the dynamic $R_on$ decreased from $160\Omega$ to $2\Omega$. This method will be useful in developing high-performance GaN power FETs suitable for use in high-efficiency converter/inverter topology design.

• 근관절건강학회지
• /
• 제16권1호
• /
• pp.36-45
• /
• 2009

Purpose: This study was to determine the effects of laughter therapy on stress response and pain of military patients with low back pain. Method: The subjects in the experimental group received 3-sessions of laughter therapy on 3 consecutive days. The primary outcome measures were state anxiety, depression, blood pressure, pulse rate and pain. Result: After 3 sessions of laughter therapy, the scores of state anxiety(p=.046), depression(p=.028) and pulse rate(p=.003) were significantly lower and diastolic blood pressure(p=.038) was significantly higher in the experimental group than those in the control group. The level of pain(p=.711) was not different significantly between two groups. Conclusion: Laughter therapy could be an effective strategic intervention for military patients with low back pain to reduce the level of anxiety and depression. Further studies are needed to determine long-term effects of laughter therapy and its effects on cardiovascular system and pain.

• 공업화학
• /
• 제10권5호
• /
• pp.711-717
• /
• 1999

다층구조 고분자 재료의 비결정성 영역에서의 파괴 역학 변형과정을 통하여 ductile 및 brittle층을 동시에 함유하는 다층 구조 가공물을 이용하여 단층 구조물과의 물성을 비교, 조사하였다. 그 결과 거의 유사한 유리 전이온도($T_g$) 및 동일한 dimension에서 다층 구조물의 충격강도가 단일층 구조물보다 현격히 높게 나타났으며, toughness는 약 2배 이상 향상됨을 알 수 있었다. 이것은 ductile층과 brittle층의 두께 비에는 임계값이 있으며, 그 이하에서는 brittle한 재료이더라도 ductile하게 나타날 수 있다는 toughening 원리가 본 실험의 측정 속도 영역 및 온도 범위에서 적용되고 있음을 의미한다. 또한 고속 균열이 진행하는 경우의 운동 응력(kinetic stress wave) 효과를 해석하기 위하여 충격파동 중첩의 원리(superposition principle of impact pulse)를 도입하였다. 그 결과 다층 구조물의 최종 toughness 향상은 ductile/brittle 비율의 최적설계에 있음을 알 수 있었다.

• 한국음향학회:학술대회논문집
• /
• 한국음향학회 1999년도 학술발표대회 논문집 제18권 1호
• /
• pp.269-273
• /
• 1999

Combination of mental stress task with noise background is a traditional tool employed in psychophysiology. However, intensity of background noise is a factor affecting both performance on test and psychophysiological responses associated with stress evoked by mental load in noisy environment. In the current study on 7 subjects we analyzed the influence of white noise (WN) intensity (55, 70, and 85 dB[A] ) on psychophysiological responses during word recognition test performed on noise background. There were recorded following physiological variables: electrodermal activity (EDA) , namely, skin conductance level (SCL), skin conductance response (SCR) amplitude (SCR-A), rise time and total number of SCRs (N-SCR); cardiovascular activity, e.g., heart rate (HR), respiratory sinus arrhythmia (RSA) index, pulse transit time (PTT), finger pulse volume (PV), skin temperature (SKT) and respiratory activity, such as respiration rate (RESP-R) and inspiration wane amplitude (RESP-A) during baseline resting state and 40 s long performance on 3 similar Korean word recognition tests with different WN intensity (55, 70, and 85 dB). Electrodermal responses (SCR-A, SCL, N-SCR) demonstrated gradual increment with increased intensity of noise, and this increase of response magnitude with higher intensity of noise was typical also for r skin temperature (phasic SKT decrease) and pulse volume (phasic and tonic PV decrease). However, some cardiovascular and respiratory responses did not exhibit same tendency of gradual increase of reactivity , namely HR, as well as RESP-R and RESP-A showed decrement of response magnitudes. Important finding in terms of cardiovascular reactivity was that 55 and 70dB evoked similar profiles, while 85dB WN resulted in significantly different profile of reactions, suggesting that there exists a threshold level after which intensive auditory stimulation elicits psychophyslological responses pattern of different quality. There are discussed potential autonomic mechanism involved in mediation of observed physiological responses.

• 기본간호학회지
• /
• 제7권2호
• /
• pp.192-207
• /
• 2000

The purpose of this study was to identify the effects of foot massage on the stress of student nurses in clinical practice. The research design was a nonequivalent control group pretest-posttest design. The subjects of this study were 52 student nurses from three junior colleges and one university. The subjects were assigned to one of two groups : the experimental group(26 students), and the control group(26 students). The study was conducted from October to November 1999. For the experimental group the foot massage was performed once a day for 3 days, starting from the first day of clinical practice. Subjects' mood, fatigue, blood pressure and pulse rate were measured as dependent variables. The Instrument for mood and fatigue state was a 100mm visual analogue scale. For the experimental group pre and post tests were done just before and after every 3 foot massages and on the 7th clinical practice day. For the control group pretest was done on 1st clinical day and posttest was done on clinical practice 7th day. The data was analyzed by the t-test and paired t-test and the results are summarized as follows: 1. The mood state scores were significantly higher for the experimental group as compared to the control group after the foot massage(t=13.73, p<.001). 2. The fatigue state scores were significantly lower for the experimental group as compared to the control group after the foot massage(t=8.69, p<.001). 3. The systolic blood pressure was significantly different between the experimental group and the control group after the foot massage(t=3.0073, p<.01). 4. The diastolic blood pressure was not significantly different between the experiment group and the control group after the foot massage. 5. The pulse rate was not significantly different between the experiment group and the control group after foot massage. 6. The mood state scores on the 1st, 2nd, 3rd massage day was significantly improved right after the foot massage. 7. The fatigue state scores on the 1st, 2nd, 3rd massage day were significantly lower right after the foot massage. 8. Systolic blood pressure on the 1st and 2nd massage day was significantly decreased right after the foot massage. Diastolic blood pressure and pulse rate were decreased right after massage but the change was not statistically significant. On the basis of the above findings, this study suggests that foot massage can be an effective stress relieving method for student nurses in clinical practice.

• 성인간호학회지
• /
• 제22권2호
• /
• pp.153-160
• /
• 2010

Purpose: The purpose of this study was to investigate the effects of aromatherapy on stress, fatigue, mood, and vital signs of the nurses in the operating rooms. Methods: The data were collected from September 2007 to February 2008 in the operating room at K hospital located in Seoul, Korea. A total of 48 nurses were recruited. Among them, 25 nurses were randomly assigned to an experimental group and 23 were assigned to a control group. Experimental group was provided with aroma inhalation by necklace which had essential oil mixture of 0.2 cc. For aroma inhalation, Lavender, Zeranium and Mazoram were mixed in ratio of 5:3:2. In order to test the effectiveness of aroma inhalation, the pretest and posttest results for stress, fatigue, mood, and vital signs were compared between the experimental group and the control group. The data were analyzed by unpaired t-test and ANCOVA using the SPSS/WIN 15.0 program. Results: There were statistically significant decreases in the stress and fatigue scores, and increase in the mood scores and showed significant relaxation in the vital signs after the aroma inhalation. Conclusion: The aromatherapy had the positive effects on stress, fatigue, mood, and vital signs.