• Tribology and Lubricants
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• 제22권2호
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• pp.93-98
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• 2006

The numerical analysis of the negative pressure porous gas bearings is presented. The pressure distribution is calculated using the finite difference method. The Reynolds equation and Darcy's equation are solved simultaneously. The air bearing stiffness and damping are evaluated using the perturbation method. Rectangular uniform grid is employed to model the bearing. The vacuum preloading is considered. The pressure in the vacuum pocket is assumed to be a constant negative pressure. The total load, stiffness, damping and flow rate are calculated fur several geometrical configurations and several values of negative pressure. It is found that too large vacuum pocket can result in negative total force.

• 한국보건간호학회지
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• 제14권2호
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• pp.271-280
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• 2000

The purpose of this study was to identify the health status of elderly. Subjects were 132 older people who live in home and institution located Taejon metropolitan city. Data were collected from May 1997 to April 1998. To obtain data about health status of elderly. pulse, respiration, systolic and diastolic blood pressure. grip strength. pinch pressure. flexibility, arm circumference. triceps skin fold thickness were measured. Data were analyzed for frequency. percentage. t-test using SPSS pc+ program. The results were as follows: 1. $74.4\%$ of subjects was perceived as 'good' in their health status. 2. Mean pulse, mean respiration, systolic and diastolic blood pressure were with in normal limits. There were no statistical differences between men and women in pulse, respiration, systolic and diastolic pressure. 3. Left and right grip strength were 24.89 psi and 25.23psi. The grip strength in men was higher than that of women. It showed statistically difference between men and women in grip strength. 4. Left and right pinch pressure were 7 pound and 7.32 pound. There was statistically difference of pinch pressure between men and women. 5. left flexibility was better than right flexibility of subjects. There was no statistically significant difference between men and women in flexibility. 6. Arm circumference was 24.96cm and there was no statistically significant difference between men and women. 7. Mean skin fold thickness was 12.83 em. Skin fold thickness in men was lower than that of women. It showed statistically difference between men and women. From these results, further study should be considered gender differences in health status of elders and carried in larger sample than this study.

• 한국전문물리치료학회지
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• 제29권3호
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• pp.180-186
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• 2022

Background: The craniocervical flexion test (CCFT) was developed for the activation and endurance of deep cervical flexors. However, the muscle thickness and muscle thickness changing ratio of the sternocleidomastoid (SCM) and deep cervical flexor (DCF) muscles in subjects with and without forward head posture (FHP) have not been reported. Objects: To determine the difference in thickness of the SCM and DCF muscles and the difference in the muscle thickness changing ratio between SCM, DCF, and DCF/SCM 20 mmHg and DCF/SCM 30 mmHg between subjects with and without FHP. Methods: Thirty subjects with and without FHP were enrolled. The muscle thickness of the SCM and DCF was measured when maintained at a baseline pressure of 20 mmHg and a maximum pressure of 30 mmHg using a pressure biofeedback unit during the CCFT. Ultrasonography was used to capture images of SCM and DCF muscle thickness during the CCFT, which was calculated using the picture archiving and communication system (PACS). Results: We observed a significant difference within the pressure main effect between SCM and DCF at a baseline pressure of 20 mmHg and a maximum pressure of 30 mmHg (p < 0.05). However, there was no significant difference in the muscle thickness and muscle thickness changing ratio for SCM and DCF during CCFT between subjects with and without FHP. Conclusion: There was no significant difference in the muscle thickness recruitment pattern during CCFT in posture changes between subjects with and without FHP.

• 대한정형도수물리치료학회지
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• 제28권1호
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• pp.61-69
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• 2022

Background: This study aimed to investigate the effect of maitland mobilization and mobilization with movement (MWM) applied to the ankle joint on ankle dorsiflexion range of motion (ROM), static and dynamic balance, plantar pressure, and gait ability. Methods: A total of 24 individuals were assigned to either the maitland mobilization group (n=12) or the MWM group (n=12). Dorsiflexion ROM, static and dynamic balance, plantar pressure, 10-meter walk test were measured before and 4 weeks after the intervention. Results: Both groups showed a significant difference in the evaluation after 4 weeks as the dorsiflexion ROM of the ankle increased (p<.05), and the sway length and sway area indicating static balance decreased (p<.05). Furthermore, the movement area showing dynamic balance showed a significant increase (p<.05), the plantar pressure difference between both feet significantly decreased (p<.05). In the 10-meter walk test, there was a significant difference as the time decreased (p<.05). However, no significant difference between the two groups was observed (p>.05). Conclusion: According to the results of this study where, maitland mobilization and MWM were applied to the ankle joint of hemiplegic patients for 4 weeks, we found no difference between the two groups. However, each technique was found to be effective for dorsiflexion ROM, static and dynamic balance, plantar pressure, and gait.

• 한국자동차공학회논문집
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• 제6권5호
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• pp.86-96
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• 1998

A numerical study has been carried out of three-dimensional turbulent flows around a MIRA reference vehicle model both with and without wheels in computation. Two convective difference schemes with two k-$\varepsilon$ turbulence models are evaluated for the performance such as drag coefficient, velocity and pressure fields. Pressure coefficients along the surfaces of the model are compared with experimental data. The drag coefficient, the velocity and pressure fields are found to change considerably with the adopted finite difference schemes. Drag forces computed in the various regions of the model indicate that design change decisions should not rely just on the total drag and that local flow structures are important. The results also indicate that the RNG model with the QUICK scheme predicts fairly well the tendency of velocity and pressure fields and gives more reliable drag coefficient rather than the other cases.

• 대한안전경영과학회지
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• 제23권4호
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• pp.43-48
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• 2021

In this study, the experiment was conducted on a fire door(W × H = 0.98 m × 2.19 m) installed on the vestibule. The effective leakage area for each opening angles and closing forces derived from the impulse-momentum equation was compared and analyzed with the experimental results. As a result of the experiment, the major factors affecting the door closing forces were the pressure difference and the area of the door. The difference of door closing forces between measured and calculated values by the impulse-momentum equation showed a deviation of less than ±15% at the opening angles of 5°to 10°. At the door opening angle of 2.5°, the dynamic pressure was much higher than the measured static pressure, and this pressure difference is estimated to be air resistance acting to prevent the door from being completely closed.

• Korean Journal of Acupuncture
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• 제40권3호
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• pp.99-108
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• 2023

Objectives : The aim of this study was to assess the quantitative characteristics of pressure pain threshold (PPT) and pressure depth (PD) at the abdominal conception vessel (CV) acupoints according to subjective digestive status and digestive discomfort levels, accomplished by comparing a large group of healthy men and women, using the modified digital algometer. Methods : A total of 1,504 healthy adults aged 19 years or older participated in this study. A questionnaire was administered to evaluate participants' digestive status and discomfort. PPT (kgf/cm²/s) and PD (mm) measurements were obtained at CV14, CV12, and CV4 acupoints using a modified digital algometer. General characteristics were analyzed using the chi-square test, and differences in PPT and PD were assessed using two-sample t-tests and ANCOVA. Results : Significant difference in PPT was found based on digestive status at CV14 and CV12 for both sexes, and in PD at CV14 for women. Women exhibited significant difference in PPT based on digestive discomfort at CV14, CV12, and CV4, while men showed significant difference at CV14 and CV12. Significant difference in PD was observed at CV14 and CV4 among women. Even after adjusting for age and body mass index, significant difference persisted in PPT based on digestive discomfort at CV14 and CV12 for both sexes. PD exhibited significant differences at CV14, CV12, and CV4 among women. Conclusions : Using the modified digital algometer, this study showed the significant difference of pressure pain threshold at the CV14 and CV12 acupoints for subjective digestive discomfort levels in healthy men and women.

• 대한가정학회지
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• 제29권1호
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• pp.13-25
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• 1991

We measured change of peripheral skin temperature and mean skin temperature when the upper arm and thigh are pressured in order to know the effect of skin pressure applied by clothing on blood circulation. After release from pressure, we observed also recovery condition. At the same time, we examined relation between pressure and a feeling of thightness. Three physiques of healthy females, namely slender, standard and plump, served as subjects. We used continuous restraint method with skin pressure applied by experimental fabric for 10 min. As a result of this experiment, we obtained following findings. 1. The significant difference was marked at the pressure, measuring time and physique with change of skin temperature under upper arm restraint. The peripheral and mean skin temperature decreased with the lapse of restraint time. A remarkable tendency observed according to the increase of restraint pressure. Recovery condition after release from pressure not yet recovered to original state, for all after a lapse of 10 min. 2. The significant difference was marked at the pressure, measuring time and physique with change of skin temperature under thigh restraint, especially different physique was remarkable among them. The peripheral skin temperature decreased or decreased. Recovery condition after release from pressure was the same upper arm. 3. Main factor affecting the evaluation of a feeling of tightness was restraint pressure. The value of pressure sensation made remarkable declined after a lapse of 10 min restraint time. Individual differences, however, were shown in pressure sensation.

• Nuclear Engineering and Technology
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• 제18권3호
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• pp.183-193
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• 1986

실제 발전소규모의 HDR 격납용기 실험에서 기존의 격납용기 해석모델에 많은 문제점들이 있다는 것이 밝혀졌는데, 그 중의 하나가 단기 (0∼2초) 압력 차이 계산이다. 격납용기의 각 구분방 사이의 압력차이는 질량 흐름율, 유체밀도, 마찰상실계수, 흐름면적비 등에 의존하는데, 각 요소가 압력 차이의 실험값과 계산값의 불일치에 어느 정도의 영향을 주는가는 정확하게 알려져 있지 않다 본 연구에서는 기존의 해석모델을 개선하기 위해 지금까지 상수로 간주되어 온 마찰상실계수를 압력과 압력차이 등의 함수로 제시되었다. COMPARE 코드로 수정된 모델을 사용하여 HDR 실험에 대한 압력과 압력차이가 계산되었는데 V.42 실험값에서는 측정치와 잘 맞고, V.43의 측정치 보다는 높게, V.44 실험값보다는 조금 낮은 결과를 보였다.

• 대한통합의학회지
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• 제5권1호
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• pp.85-92
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• 2017

Purpose : The purpose of this study was to investigate the effect of posture difference on respiratory function in cerebral palsy patients. Methods : Twenty-two cerebral palsy childrens were recruited this study. Respiratory Function test was measured with Cardio Touch 3000 and Micro Respiratory Pressure Meter. Cardio Touch 3000 was used to assess cerebral palsy childrens' forced vital capacity and forced expiratory volume at one second. Micro Respiratory Pressure Meter was to assess Maximum inspiratory pressure and Maximum expiratory pressure. Subjects had four respiratory functions measured in supine, slouched sitting, and elected sitting postures. Statistical analysis was used Paired t-test for within-group comparisons and Independent t-test for between-group comparisons. SPSS statistics Ver 20.0 was used for statistical anlysis and statistical significance was defined as a p-value less than 0.05. Result : The subjects' respiratory function according to posture showed significant difference in Forced Vital Capacity(FVC), Maximum Expiratory Pressure(MEP) and Maximum inspiratory pressure(MIP)(p<.05). Elected sitting posture had a positive effect on respiratory function than slouched sitting, supine. Conclusion : In conclusion, We could see that change of posture in children with cerebral palsy affects respiratory function and Elected sitting can be a positive help for the respiratory function of children with cerebral palsy.