• 대한치과교정학회지
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• 제31권2호통권85호
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• pp.199-207
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• 2001

본 연구는 교정치료를 시행함에 있어 전치부 crowding을 해결하기 위한 견치의 단독견인 방법중 새로운 segmented TMA T-loop spring으로 견치 후방견인시 치근단과 그 주위 치조골에서의 응력상태를 알아보기 위해 시행되었다. PL-3 epoxy resin으로 광탄성 모형을 제작하여 B/L ratio가 0.25, 0.5, 0.75인 위치로 T-loop을 위치시키고 각 위치에서 5mm, 3mm, 1mm activation하였다. 이후 광탄성 응력 해석장치를 이용하여 견치견인시 치근단과 그 주위 치조골에서의 초기 응력 상태를 광탄성법으로 분석한 바, 다음과 같은 결론을 얻었다. 1. T-looP 위치에 상관없이 activation량이 감소할수록 상악 1소구치 발치부위에 응력이 감소하였고 상악 1대구치의 함입응력은 증가하였다. 2. 5mm activation시 T-loop위치가 구치부쪽으로 이동할수록 상악 1소구치 발치부위에 응력이 증가하였다. 3. 3mm activation시 T-loop위치가 구치부쪽으로 이동할수록 상악 1소구치 발치부위와 상악 1대구치 협측 근심치근 근심면하방 1/2부위에 응력이 증가하였다. 4. 1mm activation시 T-loop위치가 견치쪽으로 이동할수록 상악 견치의 근심치근면 상방과 치근첨 하방의 응력이 증가하였다. 5. B/L ratio가 0.25이고 3mm activation시 상악견치의 치체이동이 나타났다. 이상의 결과를 종합해볼 때 segmented T-loop spring의 근, 원심 위치 와 activation량을 조절하여 원하는 치아이동과 고정원 조절이 가능하다고 사료된다.

• 전력전자학회논문지
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• 제18권1호
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• pp.1-9
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• 2013

This paper proposes a ST(Switched Trans) quasi Z-source inverter using a Switched Trans Cell combing the characteristics of a Switched Inductor Cell and Trans. A DC link inductor of the conventional quasi Z-source inverter is alternated with Switched Trans Cell of the proposed ST quasi Z-source inverter. Trans Cell of the proposed method consists of one Trans and two diodes, and the proposed method has higher and more various boost function than the conventional quasi Z-source inverter by simply changing the turns ratio of primary and secondary of the Trans. The validity of the proposed ST Z-source inverter was confirmed by PSIM simulation and a DSP based experiment under the input voltage 48V and output phase voltage 30V. As a result, when compared with the traditional quasi Z-source inverter, the proposed method has the advantage of the low voltage stress under the same output voltage condition of the voltage.

• Safety and Health at Work
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• 제11권3호
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• pp.347-352
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• 2020

Background: Low self-esteem can be an issue among health-care workers due to the hierarchical medical system. Health-care workers are also in a high pressure environment that can lead to stress and burnout. This study was conducted to estimate the proportion of health-care workers with low self-esteem, high stress, and burnout and the factors associated with these in a private hospital in Bangalore city. Methods: This cross-sectional study included a random sample of health-care workers of various cadres - doctors, nurses, nursing aides, technicians, and workers in ancillary departments such as laundry, dietary, central sterile supply department, and pharmacy, with probability proportional to size. Rosenberg Scale for Self-esteem, Cohen's Perceived Stress Scale, and Shirom-Melamed Burnout Measure were used as study tools. Results: Among the 306 health-care workers, there were high levels of low self-esteem (48.4%), stress (38.6%), and burnout (48.7%), with the lowest levels being among doctors. Those aged younger than 30 years had significantly lower self-esteem and greater stress. Conclusions: Health-care workers with low self-esteem were nearly thrice more likely to suffer high stress, Odds Ratio (OR) = 2.84 (1.36-5.92), and those who were stressed had more than three times higher chance of experiencing burnout, OR = 3.6 (2.02-6.55). Path analysis showed that low self-esteem among health-care workers had a direct effect on burnout, as well as an indirect effect through stress (mediator variable). This study indicates the need for screening and counseling for low self-esteem, stress, and burnout as part of a periodic medical examination of all cadres of health workers.

• 동의신경정신과학회지
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• 제15권1호
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• pp.197-209
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• 2004

Objectives : The purpose of this case-control research was to investigate the effects of acupuncture stimulation on autonomic nervous system for patients with HRV and to find out relationship with anti-stress effects. Methods : The study group consists of 24 patients with self-recognition of stress as the case group, and 20 normal person as the control group by similar age. We measured HRV of case and control groups before acupuncture stimulation, prick acupuncture in Hegu(LI4), Taichong(Liv3), Shenme(H7), Neiguan(P6), Zusanli(S36). After treating for 20 minutes, measurement values of HRV and PSV were compared for pre-acupuncture and post-acupuncture. Results : 1. LF norm, HF norm, LF/HF between the case and control groups were significant different in HRV before acupuncture stimulation in the 1st experiment. 2. HRT, SDNN, SDSD, LF norm, HF norm, and LF/HF of the case group were significant different in HRV after acupuncture stimulation in the 1st experiment. HRT of the case group was significantly different in HRV after acupuncture stimulation in the 1st experiment. 3. LF norm, HF norm, LF/HF of the case group were significant different between the 1st and 2nd experiment in HRV before acupuncture stimulation. 4. LF norm, HF norm, and LF/HF were significant different between the 1st and 2nd experiment in HRV of patients whose symptoms improved. But HRV of patients whose symptoms unimproved didn't show significant difference. Conclusion : The results suggest that acupuncture stimulation is associated with changed activity in the sympathetic and parasympathetic nervous system. Measurement values of HRV is suitable to estimate the activity of automatic nervous system.

• 한방재활의학과학회지
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• 제33권4호
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• pp.167-184
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• 2023

Objectives This study was designed to assess the effectiveness of ultrasound therapy at the ST11 for regulation of sympathetic hyperactivity. Methods Forty healthy adult subjects were assigned to experimental group and control group. After taking mental stress, ultrasound therapy was applied at the ST11 in experimental group and sham-ultrasound therapy was applied in control group. The evaluation of sympathetic activity was measured by blood pressure, pulse rate, and heart rate variability at 3 times (Time 1: before the stress stimulation, Time 2: after the stress stimulation, Time 3: after the intervention). The primary end point was consisted of normalized (norm) low frequency (LF)/high frequency (HF) ratio, LF (norm), HF (norm). The secondary end point was consisted of systolic blood pressure, diastolic blood pressure, pulse rate, mean heart rate, standard deviation of NN intervals, root mean square of the successive differences, total power (log). Results After the stress stimulation, all subjects showed sympathetic hyperactivity. After the intervention, the experimental group showed lower sympathetic activity than the control group. Comparing the Time 3 and Time 1, the experimental group showed no significantly differences in sympathetic activity while the control group showed higher sympathetic activity in Time 3 than Time 1. Comparing the Time 3 and Time 2, the experimental group showed lower sympathetic activity in Time 3 than Time 2 while the control group showed higher sympathetic activity in Time 3 than Time 2. Conclusions We suggest that the ultrasound therapy at ST11 can decrease sympathetic activity in sympathetic hyperactivity condition.

• 대한기계학회논문집A
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• 제23권7호
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• pp.1120-1128
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• 1999

An elastic-viscoplastic finite element analysis is performed to investigate detailed growth behavior of creep cracks and the numerical results are compared with experimental results. In Cr-Mo steel stress fields obtained from the crack growth method by mesh translation were compared with both cases that the secondary creep rate is only used as creep material property and the primary creep rate is included. Analytical stress fields, Riedel-Rice(RR) field, Hart-Hui-Riedel(HR) field and Prime(named in here) field, and the results obtained by numerical method were evaluated in details. Time vs. stress at crack tip was showed and crack tip stress fields were plotted. These results were compared with analytical stress fields. There is no difference of stress distribution at remote region between the case of 1st creep rate+2nd creep rate and the case of 2nd creep rate only. In case of slow velocity of crack growth, the effect of 1st creep rate is larger than the one of fast crack growth rate. Stress fields at crack tip region we, in order, Prime field, HR field and RR field from crack tip.

• Journal of Hospice and Palliative Care
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• 제24권2호
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• pp.116-129
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• 2021

Purpose: The purpose of this study was to examine the knowledge, caregiving performance, stress levels, and mental health of family caregivers of terminal cancer patients with delirium, insofar as these characteristics are relevant for delirium. Methods: Between May 1, 2019, and June 1, 2020, 96 family caregivers of terminal cancer patients with delirium completed a structured survey, the results of which were analyzed. Results: The average correct answer rate for delirium-related knowledge was 53.2% across all subcategories, which included knowledge of causes (41.5%), symptoms (65.4%), and caregiving (51.7%). The average score for family caregivers' performance of caregiving for delirium was 2.60±0.5, with subcategories including caregiving for patients without delirium (2.16±0.95), caregiving for patients with delirium (2.84±1.01), and stress related to caregiving for delirium (39.88±16.55), as well as categories such as patient-related caregiving (44.32±28.98), duty-related caregiving (44.21±30.15), and interpersonal relationship-related caregiving (22.35±25.03). For mental health, the average score among family caregivers was 1.96±0.70, with the highest score being for the category of additional items (2.28±0.84). Family caregivers of patients with hyperactive delirium as the delirium subtype had higher scores for caregiving performance than caregivers of patients with mixed delirium. Conclusion: Scores for the delirium-related knowledge and caregiving performance of family caregivers were low, while their caregiving stress levels were high due to their lack of knowledge and experience. This indicates the importance of delirium-related education for family members of patients with delirium and the necessity of developing nursing intervention programs to help manage stress and promote mental health among family caregivers.

• 음성과학
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• 제9권4호
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• pp.113-130
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• 2002

Measurements were made of pressure rise time (PoRT), voice cessation time, flattened peak intraoral air pressure (Po), pressure static time (PoST), pressure-fall time and the duration of oral closure as four English speakers uttered isolated nonsense $V_{1}CV_{2}$ words containing /b/ and /p/ ($V_{1}=V_{2}$ and the V was /$\alpha$/), with stress on either $V_{1}orV_{2}$ alternately. The hypothesis tested was: The tense stop consonant. will be characterized either by a higher Po or a longer PoST, and/or by both against lax. Findings: (1) PoRT was significantly greater in /b/ than /p/, (2) the voiceless stop /p/ produced generally greater mean Po, averaged across five tokens, than its voiced counterpart /b/, but statistically insignificant, and (3) altogether, across stress, tokens and subjects, the difference in the calculated pressure static time (PoSTc), i.e., PoST + PoRT, between /p/ and /b/ was highly significant (p $\leq$ 0.003). Although further investigations remain to be taken, the results strongly supported the linguistic hypothesis of tense-lax distinction, with /b/ being lax and /p/ tense. Airflow resistance at the glottis and supraglottal air volume are assumed to be responsible for much of difference in PoRT between /p/ and /b/. The PoSTc reflecting, although indirectly, the respiratory efforts during the oral closure of a stop, was a convincing phonetic parameter of the consonantal tenseness based on respiratory efforts. The effects of stress on Po and PoSTc were inconsistent, and the shorter PoRT than consonantal constriction interval was always accompanied by Po and PoST.

• 임상간호연구
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• 제22권1호
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• pp.38-45
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• 2016

Purpose: The purpose of this study was to understand the effects of verbal violence experience, social support, and coping patterns on job stress among operating room(OR) nurses. Methods: The participants were 214 operating room nurses in general hospitals. Data were collected from April 1st to May 1st in 2013 and were analyzed using a multiple regression. Results: The most influencing factor on job stress for OR nurses was verbal violence experience from doctor(${\beta}=.35$), and verbal violence experience from nurse (${\beta}=.27$) followed. Social support from co-workers was a significant factor in decreasing job stress (${\beta}=-.22$). Those three factors explained 43.0% (F=54.76, p<.001) of OR nurses' job stress. Conclusion: The findings of this study revealed that doctors' and nurses' verbal violence increased job stress of OR nurses and social support from co-workers was found decreasing OR nurses' job stress. The results of the study provides an necessity for developing an effective program for minimizing job stress of OR nurses caused by work place verbal violence.

• Journal of Hospice and Palliative Care
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• 제26권3호
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• pp.112-125
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• 2023

Purpose: This study investigated knowledge, attitudes, and nursing stress related to life-sustaining treatment among oncology nurses. Methods: A descriptive study design was used. Data were collected through a survey from April 1 to May 31, 2022. The participants were 132 nurses working in the oncology ward of a tertiary hospital in Seoul. Data were analyzed using the SPSS 25.0 program with descriptive statics, the independent t-test, analysis of variance, and Pearson correlation coefficients. Results: The average scores for knowledge, attitudes, and nursing stress related to life-sustaining treatment were 14.42, 3.29, and 3.96, respectively. Significant differences in knowledge about life-sustaining treatment were observed based on clinical experience (P=0.029) and education about life-sustaining treatment (P=0.044). Attitudes toward life-sustaining treatment varied significantly with education about life-sustaining treatment (P=0.014), while stress levels differed significantly across working units (P=0.004). A positive correlation was found between the dilemma of extending or stopping life-sustaining treatment (a subdomain of nursing stress) and attitudes toward life-sustaining treatment (r=0.260, P=0.003). Conclusion: There was no significant correlation between the nursing stress experienced by oncology nurses and their knowledge and attitudes toward life-sustaining treatment. However, a more positive experience with life-sustaining treatment education was associated with higher stress levels related to the dilemma of extending or stopping life-sustaining treatment. Therefore, it is crucial to develop strategies to manage this dilemma and reduce stress in the field.