• 제목/요약/키워드: Symmetrical

검색결과 1,253건 처리시간 0.03초

A review on uplift response of symmetrical anchor plates embedded in reinforced sand

  • Niroumand, Hamed;Kassim, Khairul Anuar
    • Geomechanics and Engineering
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    • 제5권3호
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    • pp.187-194
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    • 2013
  • The most soil anchor works have been concerned with the uplift problem on embedded in non-reinforced soils under pullout test. Symmetrical anchor plates are a foundation system that can be resisting tensile load with the support of around soil in which symmetrical anchor plate is embedded. Engineers and authors proved that the uplift response can be improved by grouping the symmetrical anchor plates, increasing the unit weight, embedment ratio and the size of symmetrical anchor plates. Innovation of geosynthetics in the field of geotechnical engineering as reinforcement materials found to be possible solution in symmetrical anchor plate responses. Unfortunately the importance of reinforcement in submergence has received very little attention by researchers. In this paper, provision of tensile reinforcement under embedded conditions has been studied through uplift experiments on symmetrical anchor plates by few researchers. From the test results it has been showed that the provision of geogrid reinforcement system enhances the uplift response substantially under uplift test although other results are such as increase the ultimate uplift response of symmetrical anchor plate embedded using geosynthetic and Grid Fixed Reinforced (GFR) and symmetrical anchor plate improvement is very dependent on geosynthetic layer length and increases significantly until the amount of beyond that further increase in the layer length does not show a significant contribution in the anchor response.

Analysis of Transportation Movements in Patients with Hemiparesis

  • Kim, Do-Yeong;Kim, Tae-Hoon
    • International Journal of Internet, Broadcasting and Communication
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    • 제12권2호
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    • pp.15-20
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    • 2020
  • The objectives of this study were to compare unimanual, symmetrical and reciprocal movement of transportation. Nineteen participants with post-stroke hemiparesis were involved in this study. We used the Fitmeter accelerometer to measure the dependent variables: signal vector magnitude, peak acceleration and peak deceleration. With respect to the hand and arm, intensity of unimanual movement was higher than that of symmetrical movement, and reciprocal movement was greater than that of symmetrical movement. With regard to the trunk, intensity of unimanual movement was lower than that of symmetrical movement, and within bimanual movement, reciprocal movement was greater than that of symmetrical movement. In conclusion, reciprocal movement would facilitate upper extremity movement and decrease the compensatory movement of trunk more than would symmetrical movement.

냉간 대칭/비대칭 압연시 압연변형율 상태와 집합조직의 형성 (Evolution of Strain States and Textures During Symmetrical/Asymmetrical Cold Rolling)

  • 허무영;이재필;이재협
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2004년도 제5회 압연심포지엄 신 시장 개척을 위한 압연기술
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    • pp.19-24
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    • 2004
  • Symmetrical and asymmetrical rolling was performed in AA 1050 sheets. Asymmetrical rolling was carried out by using different roll velocities of upper and lower rolls. The effect of the reduction per rolling pass on the formation of textures and microstructures during symmetrical and asymmetrical rolling was studied. In order to intensify the shear deformation, symmetrical and asymmetrical rolling was carried out without lubrication. The strain states associated with rolling were investigated by simulations with the finite element method (FEM). A fairly homogeneous residual shear strain throughout the sheet thickness was observed after asymmetrical rolling. Symmetrical rolling with a high friction gave rise to a strong net shear strain gradient in the sheet thickness.

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Least Square Method: A Novel Approach to Determine Symmetrical Components of Power System

  • Rehman, Bilawal;Liu, Chongru;Wang, Lili
    • Journal of Electrical Engineering and Technology
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    • 제12권1호
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    • pp.39-44
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    • 2017
  • This paper proposes a novel approach to determine symmetrical components of power system by applying method of least squares in time domain. For the modern power system stability, clearance of faults on high voltage transmission lines in zero response time is crucial and important. Symmetrical components have a great attention since last century. They have been found an effective tool for the analysis of symmetrical and unsymmetrical faults in power system. Moreover, magnitude of symmetrical components are also used as a caution about faults in system. With rapid changes in technology, Microprocessor assumed to be fastest machine of the modern era. Hence microprocessor based techniques were developed and implemented for last few decades. The proposed technique apply least square method in the computation of symmetrical components which is suitable as an application in microprocessor based monitoring and controlling power system in order to avoid cascading failures. Simulation of proposed model is carried out in MATLAB/SIMULINK and all results exploit the validity of model.

Performance and Flow Condition of Cross-Flow Wind Turbine with a Symmetrical Casing Having Side Boards

  • Shigemitsu, Toru;Fukutomi, Junichiro;Toyohara, Masaaki
    • International Journal of Fluid Machinery and Systems
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    • 제9권2호
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    • pp.169-174
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    • 2016
  • A cross-flow wind turbine has a high torque coefficient at a low tip speed ratio. Therefore, it is a good candidate for use as a self-starting turbine. Furthermore, it has low noise and excellent stability; therefore, it has attracted attention from the viewpoint of applications as a small wind turbine for an urban district. However, its maximum power coefficient is extremely low (10 %) as compared to that of other small wind turbines. In order to improve the performance and flow condition of the cross-flow rotor, the symmetrical casing with a nozzle and a diffuser are proposed and the experimental research with the symmetrical casing is conducted. The maximum power coefficient is obtained as $C_{pmax}=0.17$ in the case with the casing and $C_{pmax}=0.098$ in the case without the casing. In the present study, the power characteristics of the cross-flow rotor and those of the symmetrical casing with the nozzle and diffuser are investigated. Then, the performance and internal flow patterns of the cross-flow wind turbine with the symmetrical casings are clarified. After that, the effect of the side boards set on the symmetrical casing is discussed on the basis of the analysis results.

PNF Concept중 Scapula and Pelvis의 Symmetrical Reciprocal Pattern이 Hemiplegia환자의 보행속도와 균형감각에 미치는 효과 (Effect of Symmetrical Reciprocal Pattern of Scapula and Pelvis in PNF Concept on the Gait Speed and Balance of thePatients with Hemiplegia)

  • 맹관철;백선영
    • PNF and Movement
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    • 제13권2호
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    • pp.73-80
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    • 2015
  • Purpose: The purpose of this study was to determine the effect of symmetrical-reciprocal pattern of scapula and pelvis exercises using proprioceptive neuromuscular facilitation (PNF) on gait speed and balance in patients with hemiplegia. Methods: Among the adult patients with hemiplegia that were hospitalized at Michuhol Rehabilitation Center after being diagnosed with stroke, 10 that were capable of independent walking for more than five minutes and that understood and cooperated with the therapy and test methods of this research, were selected as subjects. The therapy was implemented based on the concept of PNF, and it was performed on a low mat and a height-adjustable mat, as proscribed by the fundamental procedure for PNF. Symmetrical-reciprocal pattern of scapula and pelvis exercises were applied to the patients in the decubitus position. The therapy scheme included stabilizing reversals, rhythmic stabilization, and a combination of isotonics, rhythmic initiation, and dynamic reversals. To investigate gait speed and body trunk mobility before and after the symmetrical-reciprocal pattern of scapula and pelvis exercises were applied, walking speed for a distance of 10 m was measured and balance was tested based on the Berg-Balance scale test table. The Berg-Balance scale test was performed by one therapist to minimize any error that could occur from the subjective evaluation method used by therapists. Results: Gait speed increased by 8.97 seconds after applying the symmetrical-reciprocal pattern of scapula and pelvis exercises using the concept of PNF, showing a significant difference (p<0.01). However, balance showed no significant difference after the therapy (p>0.14). Conclusion: Exercise therapy that uses the symmetrical-reciprocal pattern of scapula and pelvis with the concept of PNF can be said to be a useful therapeutic technique that can enhance the walking speed of patients with hemiplegia.

Multi-Parameter Lamb Wave Tomography

  • Choi, Jae-Seung;Kline, Ronald A.
    • Journal of Mechanical Science and Technology
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    • 제14권1호
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    • pp.1-10
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    • 2000
  • This work shows that it is possible to obtain information about more than one parameter from acoustic field information. A variety of ultrasonic Lamb wave modes were utilized to reconstruct thickness and density of an isotropic plate. An image reconstruction of one parameter (thickness of a plate) was carried out for four cases, i.e., the lowest symmetrical and anti symmetrical modes, and the fastest symmetrical and anti symmetrical Lamb waves among multiple modes. For two parameter reconstructions (thickness and density), the image processing was performed using the lowest symmetrical and antisymmetrical modes simultaneously. In this work, a modified version of algebraic reconstruction technique (ART), which is a form of finite-series expansion method, was employed to reconstruct the ultrasonically computed tomographic images. Results from several sample geometries are presented.

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비대칭 결합선로를 이용한 GaAs FET 증폭기의 설계 (Design of GaAs FET Amplifier Using Non-symmetrical Coupled Line)

  • 강희창;진연강
    • 한국통신학회논문지
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    • 제14권2호
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    • pp.146-154
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    • 1989
  • 비대칭2선 마이크로스트립선으로 구성된 DC블록(비대칭 DC블록)을 GaAs FET의 입력과 출력측에 사용하여 임피던스 정합을 시키는 새로운 증폭기 설계방법을 제시하였다. 중심파수 4(GHz)에 대하여 대칭이 되는 주파수특성을 얻을 수 있었다. 비대칭 DC블록은 \ulcorner케패시터의 DC블록의 역할뿐만 아니라 임피던스 정합도 할 수 있다는 큰 장점으로 MC 및 MMIC 용으로 사용 가능하다.

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비균질 매질내에서 대칭 및 비대칭구조를 갖는 3선 4포트 스트맆선 결합회로의 설계 (Design of the Symmetrical and Non-symmetrical Interdigitated Three-Line Four-port Microstrip Line Couplers in an Inhomogeneous Medium)

  • 진연강
    • 한국통신학회논문지
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    • 제10권6호
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    • pp.287-295
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    • 1985
  • 현재 실용화 하고 있는 4선 4포트 마이크로 스트립결합기보다 1회선이 더 적지만 그 특성이 비등하면서 더 간단한 구조를 갖는 대칭 및 비대칭 3선 4포트 결합기의 해석과 설계방법을 제시하였다. 유전율이 2.55이고 10인 유전체에서 3.6과 10dB용 결합기를 설계하는데 필요한 표와 도표를 구했다.

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대칭형 물체의 진동 진폭 분포 측정을 위한 레이디얼 전단 간섭계에 대한 연구 (A Study on Radial Electronic Shearography for Measuring Amplitudes of Vibration of Symmetrical Objects)

  • 강영준;최장섭;노경완
    • 한국정밀공학회지
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    • 제14권12호
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    • pp.9-16
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    • 1997
  • In this paper, a newly radial electronic shearography system was developed in order to study vibration characteristics of symmetrical objects. We utilized the electro-optic holography theory for quantificational analysis and a porror prism for shearing two inages radially in this study. These image data obtained by this shearography give us various distributions of the gradient of vibration amplitude, and they are useful informations to study vibrational characteristics of symmetrical objects. Finally this developed system with phase stepping and modulation was applied to fans and disks to inspect characteristics of the vibration and the blance of symmetrical objects and obtained good results.

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