• Title/Summary/Keyword: External Pressure

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Influence of Trunk Control Using Pelvic Movements upon the Foot Pressure in Patients with Hemiplegia (골반동작을 이용한 체간조절이 편마비 환자의 족저압에 미치는 영향)

  • Kim, Ji-Hye;Hwang, Byong-Yong;Oh, Tae-Young
    • The Journal of Korean Physical Therapy
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    • v.19 no.5
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    • pp.11-19
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    • 2007
  • Purpose: The purpose of this study was to examine effect of trunk control using pelvic movements upon the foot pressure in patients with hemiplegia. Methods: Twelve males with hemiplegia were the procedure executed turnk control using pelvic movements. The foot pressure were measured using Parotec-system. Results: The data were analysed with paired t-test. First, there was a significant increase in external and internal sensors of dynamic foot pressure change of the hindfoot before and after therapy. Also there was significant increase in hallux (p<0.05). Second, there was a significant increase of affected side in support phase(p<0.05) and decreased of affected side in overlapping phase(p<0.05). Third, there was a significant increase in foot floor contact time and impulse pressure rate between affected and non affected side(p<0.05). Conclusion: The trunk control with pelvic movement had an significant effect on the legs by increase activities of hip flexors and abductors. Also had an effect on ankle dorsiflexion and plantar flexor by biomechanical movement.

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Analysis of External Peak Pressure Coefficients for Cladding in Elliptical Retractable Dome Roof by Wind Tunnel Test (풍동 실험을 통한 타원형 개폐식 돔 지붕의 외장재용 풍압 계수 분석)

  • Lee, Jong-Ho;Kim, Yong-Chul;Cheon, Dong-Jin;Yoon, Sung-Won
    • Journal of Korean Association for Spatial Structures
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    • v.20 no.1
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    • pp.49-59
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    • 2020
  • This study investigates the wind pressure characteristics of elliptical plan retractable dome roof. Wind tunnel experiments were performed on spherical dome roofs with varying wall height-span ratios (0.1~0.5) and opening ratios (0%, 10%, 30% and 50%), similar to previous studies of cirular dome roofs. In previous study, wind pressure coefficients for open dome roofs have been proposed since there are no wind load criteria for open roofs. However, in the case of Eeliptical plan retractable dome roof, the wind pressure coefficient may be largely different due to the presence of the longitudinal direction and transverse direction. The analysis results leads to the exceeding of maximum and minimum wind pressure coefficients KBC2016 code.

The Evaluation on Behavior of Segmental Grid Retaining Wall by Model Test (압밀주입에 의한 지반개량 특성고찰)

  • Kim, Sang-Su;Bae, Woo-Seok;Lee, Jong-Kyu
    • 기술발표회
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    • s.2006
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    • pp.162-171
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    • 2006
  • Segmental Grid Retaining Wall is one of the segmental grid retaining walls using headers and stretchers to establish the framework of the wall In this method, grids formed by the intersection of headers and stretchers are generally filled with the gravel to maintain the weight of the wall Therefore, the construction can be carried out with higher speed and much economically when compared with the concrete retaining wall Furthermore, it has high drain capacity, and environmentally friendly aspects also have been pointed out because the possibility of the planting at the front of the wall However, in the segmental grid retaining wall method, the relative movement between the individual headers and stretchers was generally recognized, and stress redistribution in the gravel filling was also observed when subjected to the external loading and self-weight of filling Therefore, it has been thought that the distribution of the earth pressure in the segmental grid retaining wall system differ from that of the concrete retaining wall In this study, the surcharge tests using the scaled model segmental grid retaining wall was carried out to observe the distribution of the earth pressure in the segmental grid retaining wall The earth pressure was measured in the six specified height of wall, and the distribution of the pressure was analyzed. Furthermore, the earth pressure by computation or by the test using the concrete retaining wall was also considered to make comparison

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Combustion Performance Characteristics of a High Pressure Sub-scale Liquid Rocket Combustor (고압 축소형 연소기의 연소 성능 특성에 관한 연구)

  • Kim, Jong-Gyu;Lee, Kwang-Jin;Seo, Seong-Hyeon;Han, Yeoung-Min;Choi, Hwan-Seok
    • Journal of the Korean Society of Propulsion Engineers
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    • v.11 no.5
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    • pp.31-36
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    • 2007
  • Combustion performance characteristics of subscale high-pressure combustor were investigated at 70 bar combustion pressure. All tests were successfully performed without any damage on the combustor. The mixing characteristics and distribution pattern of the injectors were found to have considerable influence on the combustion performance. The characteristic velocity of the combustor was higher in the injector with internal mixing than that of external mixing and in the injector with smaller mass flowrate. The pressure fluctuations at the propellant manifolds and the combustion chamber were measured to be less than 3% of the mean combustion pressure to meet the combustion stability criterion and to prove stable combustion characteristics of the combustor.

Correlation between the Diaphragmatic Contraction Pressure and the Slow Vital Capacity

  • Lee, Jae-Seok;Han, Dong-Wook;Kang, Tae-Wook
    • Journal of the Korean Society of Physical Medicine
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    • v.14 no.3
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    • pp.47-53
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    • 2019
  • PURPOSE: This study measured the external pressure on abdomen during maximal inspiration. The study determined the correlation between the diaphragmatic contraction pressure and the lung capacities to verify whether or not the measured pressure values can represent diaphragmatic contractility. METHODS: The study included 32 healthy subjects (16 males and 16 females). The researchers fabricated their own diaphragmatic pressure belt (DiP Belt) to measure DCP. DiP Belt device was fixed on the front of the abdomen and the diaphragmatic contractility was measured during maximal inspiration. The lung capacities were measured using a portable digital spirometer device (Pony Fx, COSMED, Italy). A digital spirometer is a device that is used to test the flow of air entering and exiting the lungs. RESULTS: DCP showed significant positive correlations with vital capacity (VC), inspiratory reserve volume (IRV) and inspiratory capacity (IC). Among values of lung capacities, IC showed especially strong positive correlations with the DCP (r =.714, p<.010). For the males, DCP showed significant positive correlations with IRV and IC, and DCP showed significant negative correlation with the expiratory reserve volume (ERV). For the females, DCP showed significant positive correlation with tidal volume (VT), but any significant correlation was not found with any of the other values of lung capacities. CONCLUSION: DCP showed high correlations with IRV and IC associated with inspiratory capacity. Therefore, The DiP Belt can be looked upon as a simple device that is very useful for measuring diaphragmatic contractility.

Analysis of flow rate of variable displacement compressor ECV in automobile air conditioning control system (자동차 공조장치의 가변압축기 ECV 유량 분석)

  • Jeong, Yeong Jun;Cho, Haeng Muk
    • Journal of Energy Engineering
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    • v.22 no.4
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    • pp.394-398
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    • 2013
  • At present, using of electromagnetic control valve (ECV) in external variable displacement swash plate type compressor is a common issue. Solenoid operated ECV controls vehicle air conditioning system through a pulse width modulation (PWM) input signal that supplied from an external source. Different port pressure controls the swash plate movement inside the compressor at certain angles that finally determines the refrigerant flow rate to the vehicle compartment for passengers comfort. In this paper, crankcase pressure flow (Pc flow) is calculated with some ECV samples with corresponding to amount of variable supply of current ranges from 0.20Amp to 0.95Amp.

Fretting-wear Characteristics of Steam Generator Helical Tubes (증기발생기 나선형 전열관의 프레팅 마모 특성)

  • Jong Chull Jo;Woong Sik Kim;Hho Jung Kim;Tae Hyung Kim;Myung Jo Jhung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.14 no.4
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    • pp.327-335
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    • 2004
  • This study investigates the safety assessment of the potential for fretting-wear damages caused by foreign object in operating nuclear power plants. To get the natural frequency, corresponding mode shape and participation factor, modal analyses are performed for the helical type tubes with various conditions. The wear rate of helical type tube caused by foreign object is calculated using the Archard formula and the remaining life of the tube is predicted, and discussed in this study is the effect of the vibration of the tube on the remaining life of the tube. In addition, addressed is the effect of the external pressure on the vibration and fretting-wear characteristics of the tube.

Study on the Pixel Design for the Prerrue-stable Fringe-field Switching (FFS) Mode with 3 Slit Structure (압력에 안정한 3분할 FFS 모드의 화소 설계에 관한 연구)

  • Kim, Mi-Sook;Seen, Seung-Min;Jung, Yeon-Hak;Kim, Hayng-Yuil;Kim, Seo-Yoon;Lim, Young-Jin;Lee, Seung-Hee
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.18 no.7
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    • pp.647-651
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    • 2005
  • We studied the external pressure-stable advanced frnge field switching (FFS) pixel design with 3 slit sructue. In this mode, a patterned pixel slit is partitioned into 3 areas, namely, two edges and a center, where the edge slit angle is larger than the center slit angle. Thus the reverse twist region in the pixel edge is reduced comparing to the conventional FFS mode so that the LC dynamics in this region becomes very stable. And also, when the external pressure is applied to the panel at the high voltage, the disclination lines (DLs) were barely intruded into active area. Therefore, the structure is use for the pen based system such as the tablet personal computer (PC), personal digital asistant (PDA).

Buckling behaviours of functionally graded polymeric thin-walled hemispherical shells

  • Uysal, Mine U.
    • Steel and Composite Structures
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    • v.21 no.4
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    • pp.849-862
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    • 2016
  • This paper investigates the static buckling behaviours of Functionally Gradient Polymeric Material (FGPM) shells in the form of hemispherical segment. A new FGPM model based on experimental was considered to investigate the buckling problem of thin-walled spherical shells loaded by the external pressure. The spherical shells were formed by FGPM which was produced adding the two types of graphite powders into epoxy resin. The graphite powders were added to the epoxy resin as volume of 3, 6, 9, and 12%. Halpin-Tsai and Paul models were used to determine the elastic moduli of the parts of FGPM. The detailed static buckling analyses were performed by using finite element method. The influences of the types and volume of graphite powders on the buckling behaviour of the FGPM structures were investigated. The buckling loads of hemispherical FGPM shells based on Halpin-Tsai and Paul models were compared with those determined from the analytical solution of non-graphite condition existing for homogeneous material model. The comparisons between these material models showed that Paul model was overestimated. Besides, the critical buckling loads were predicted. The higher critical buckling loads were estimated for the PV60/65 graphite powder due to the compatible of the PV60/65 graphite powder with resin.

Simulation of a piezoelectric flextentional deep-water sonar transducer using a coupled FE-BEM (결합형 유한요소-경계요소 기법을 사용한 심해저용 압전형 유연성 쏘나 변환기의 시뮬레이션)

  • Jarng Soon Suck;Lee Je Hyeong;Ahn Heung Gu;Choi Heun Ho
    • Proceedings of the Acoustical Society of Korea Conference
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    • spring
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    • pp.218-223
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    • 1999
  • A piezoelectric flextentional deep-water sonar transducer has been simulated using a coupled FE-BEM. The dynamics of the sonar transducer is modelled in three dimensions and is analyzed with extern리 electrical excitation conditions as well as external acoustic pressure loading conditions. Different results are available such as steady-state frequency response for RX and TX, displacement modes, directivity patterns, back-scattering patterns, resonant frequencies, bandwidths, quality factors, transmitting voltage (TV) responses, input receiving sensitivity (RS) responses. White the present barrel-stave typed sonar transducer of the piezoelectric material is being simulated, the external surface of the transducer is modified in order to allow the same water pressure to be applied to the inner and the outer surfaces of the transducer. With this modification for deep-water application, the resonance frequency of the modified flextentional sonar transducer becomes much lower than that of the unmodified flextentional sonar transducer. The results of the present sonar transducer modelling are also compared with those of a commercial package such as ATILA.

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