• Title/Summary/Keyword: The Ratio Function

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Relation between Weight Bearing Ratio in the Standing Posture Immediately after Performing Standing Task and Balance and Functional Ambulation in Stroke Patients

  • Hwang, Da-Gyeom;Kim, Joong-Hwi
    • The Journal of Korean Physical Therapy
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    • v.27 no.5
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    • pp.320-324
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    • 2015
  • Purpose: The purpose of this study was to provide methods for assessment of functional balance through study of correlation with the weight bearing ratio, functional balance, and functional gait on patients with stroke. Methods: Thirty-nine patients with stroke participated in this study. The timed up and go test was used to measure balance and the functional ambulation category test to measure functional gait. Weight bearing was measured in the quiet standing posture and weight bearing in the quiet standing posture immediately after performing the standing-task. Results: Both timed up and go test and functional ambulation category test showed significant correlation with balance in the quiet standing posture immediately after performing the standing task. Conclusion: Measurement of balance in the quiet standing posture immediately after performing the standing-task was considered a meaningful scale for measurement of both balance function and gait function of patients with stroke.

Inelastic analysis of RC beam-column subassemblages under various loading histories

  • You, Young-Chan;Yi, Waon-Ho;Lee, Li-Hyung
    • Structural Engineering and Mechanics
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    • v.7 no.1
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    • pp.69-80
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    • 1999
  • The purpose of this study is to propose an analytical model for the simulation of the hysteretic behavior of RC (reinforced concrete) beam-column subassemblages under various loading histories. The discrete line element with inelastic rotational springs is adopted to model the different locations of the plastic hinging zone. The hysteresis model can be adopted for a dynamic two-dimensional inelastic analysis of RC frame structures. From the analysis of test results it is found that the stiffness deterioration caused by inelastic loading can be simulated with a function of basic pinching coefficients, ductility ratio and yield strength ratio of members. A new strength degradation coefficient is proposed to simulate the inelastic behavior of members as a function of the transverse steel spacing and section aspect ratio. The energy dissipation capacities calculated using the proposed model show a good agreement with test results within errors of 27%.

DANTE Fast MR imaging Using Frequency Modulation (주파수 변조를 이용한 MR DANTE 고속 영상법)

  • Ro, Y.M.;Chung, S.T.;Hong, I.K.;Cho, Z.H.
    • Proceedings of the KOSOMBE Conference
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    • v.1995 no.05
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    • pp.42-44
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    • 1995
  • The original DANTE sequence and its variations have limitation in excitation profile (a sinc function-like excitation) due to the finite duration of the DANTE pulsetrain. This sinc function-like selection profile excites only a small fraction of the spins in the pixel thereby results in poor signal to noise ratio (only about ${\sim}1%$ of normal MR imaging sequence). Therefore, this poor signal to noise ratio (SNR) has been the main drawback of the original DANTE sequence. To improve the signal to noise ratio, phases of individual RF pulses in the DANTE pulse train were modulated so that more spins in the object were excited ($1{\sim}3$). We have introduced a new FM (Frequency Modulation) DANTE sequence and analyzed the signal intensity and excitation profiles.

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Analysis of Combustion Instabilities in a 2-stage Duct System using Transfer Functions (전달함수를 이용한 2단 덕트 시스템에서의 연소불안정 해석)

  • Kim, Seonyeong;Kim, Daesik
    • Journal of ILASS-Korea
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    • v.26 no.4
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    • pp.182-188
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    • 2021
  • In this paper, using a transfer function-based analytical model, major factors influencing the acoustics and combustion instability in a two-stage duct system composed of a nozzle and a combustor were derived and their quantitative effects were evaluated. From the acoustic analysis, it was confirmed that the change in reflection coefficient and mean flow could have a great influence on the instability growth rate, and the area ratio and speed of sound ratio between the nozzle and the combustor are also key parameters to determine combustion instability as well as flame transfer functions.

Optimization of a Thermally Asymmetric Rectangular Fin: Based on Fixed Fin Height

  • Kang, Hyung-Suk
    • International Journal of Air-Conditioning and Refrigeration
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    • v.13 no.3
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    • pp.145-151
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    • 2005
  • A thermally asymmetric straight rectangular fin is analysed and optimized using the two-dimensional separation of variables method. The optimum heat loss is presented as a function of bottom to top Biot number ratio, fin base length and top Biot number. Decreasing rate of the optimum fin length with the increase of the fin base length is listed. The optimum fin tip length is shown as a function of bottom to top Biot number ratio, fin base length and tip to top Biot number ratio. One of the results shows that the optimum heat loss and the actual optimum fin length decrease while the optimum fin tip length increases as the fin base length increases.

A Study on the Development of a Three Dimensional Structured Finite Elements Generation Code (3차원 정렬 유한요소 생성 코드 개발에 대한 연구)

  • Kim, Jin-Whan
    • Journal of Ocean Engineering and Technology
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    • v.13 no.1 s.31
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    • pp.11-17
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    • 1999
  • A three dimensional finite element generation code has been developed attaching simple blocks. Block can be either a quadrature or a cube depending on the dimension of a subject considered. Finite element serendipity basis functions are employed to map elements between the computational domain and the physical domain. Elements can be generated with wser defined progressive ratio for each block. For blocks to be connected properly, a block should have a consistent numbering scheme for vertices, side nodes, edges and surfaces. In addition the edge information such as the number of elements and the progressive ratio for each direction should also be checked for interfaces to have unique node numbers. Having done so, user can add blocks with little worry about the orientation of blocks, Since the present the present code has been written by a Visual Basic language, it can be developed easily for a user interactive manner under a Windows environment.

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Empirical formulations for evaluation of across-wind dynamic loads on rectangular tall buildings

  • Ha, Young-Cheol
    • Wind and Structures
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    • v.16 no.6
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    • pp.603-616
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    • 2013
  • This study is aimed at formulating an empirical equation for the across-wind fluctuating moment and spectral density coefficient, which are needed to estimate the across-wind dynamic responses of tall buildings, as a function of the side ratios of buildings. In order to estimate an empirical formula, wind tunnel tests were conducted on aero-elastic models of the rectangular prisms with various aspect and side ratios in turbulent boundary layer flows. In this paper, criteria for the across-wind fluctuating moment and spectral density are briefly discussed and the results are analyzed mainly as a function of the side ratios of the buildings. Finally, empirical formulas for the across-wind fluctuating moment coefficient and spectral density coefficient according to variation of the aspect ratio are proposed.

Estimation of Vertical Vibration using Characteristics of Transfer Function (전달함수 특성을 이용한 연직진동 특성 예측)

  • Woo, Woon-Taek;Park, Tae-Won;Chung, Lan
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2001.09a
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    • pp.171-176
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    • 2001
  • Recent building structures are superior in its ability but they are light and flexible, and so have problems of vibration. In general, the problem of vertical vibration is not considered in structural design. However, in terms of serviceability for inhabitants in buildings, the estimation of vibration in design stage is important. Characteristics of vertical vibration is changed by modeling method of beam-column joint. To check the characteristics of vertical vibration, many tests and analyses were conducted on constructing building in Seoul. Results of tests and analyses were compared using transfer function. As a results, to check the vertical vibration, the cramp ratio of beam-column joint must be considered and reduced in structural design.

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Correlation between Serum Component and Immune Function in Korean Female Colleges Students (여대생의 혈액성상과 면역 기능의 상관관계)

  • 이현옥;승정자
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.5
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    • pp.920-927
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    • 1998
  • The purpose of this study was to investigate the correlation between serum component and immune function in Korean female college students according to the body mass index. There were significant increased in weight, body fat, LBM, TBW, WHR in subjects as their BMI increase(p<0.001). It was found obese group had higher levels of serum components such as total cholesterol, LDL-cholesterol and Cu levels than those of the normal group. There was a significant positive correlation between HDL-cholesterol level and NK cell number(p<0.01), between A/G ratio and T lympocytes number(p<0.05), between Cu levels and B lympocytes(p<0.01) in normal group. There was a significant positive correlation between TG level and CD4/8 ratio(p<0.001), between and IgG(p<0.001) in obese group.

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Shape Optimization of Heat Transfer Surfaces with Staggered Ribs To Enhance Thrbulent Heat Transfer (난류열전달 향상을 위한 엇갈린 리브가 부착된 열전달면의 형상최적설계)

  • Kim, Hong-Min;Kim, Kwang-Yong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.9
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    • pp.1351-1359
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    • 2003
  • This study presents a numerical procedure to optimize shape of streamwise periodic ribs mounted on both of the principal walls to enhance turbulent heat transfer in a rectangular channel flow. The response surface method is used as an optimization technique. The optimization is based on Navier-Stokes analysis of flow and heat transfer with $k-{\varepsilon}$ turbulence model. The width-to-height ratio of a rib, rib height-to-channel height ratio and rib pitch to rib height ratio are chosen as design variables. The object function is defined as a function of heat transfer coefficient and friction drag coefficient with weighting factor. Optimum shapes of the rib have been obtained for the range of 0.02 to 0.1 of weighting factor.