Knowledge Management System (KMS) is one way to organize and documented the knowledge of institution. The purpose of this study is to develop a prototype KMS in organizing and documenting the knowledge in the universi...
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Introduction Cells can sense and respond to the mechanical microenvironment by converting forces into biochemical signals inside the cells,*** adhesions are the major sites of interaction between a cell and its extrac...
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Introduction Cells can sense and respond to the mechanical microenvironment by converting forces into biochemical signals inside the cells,*** adhesions are the major sites of interaction between a cell and its extracellular matrix(ECM) microenvironment, thus outside mechanical signals can be sensed at focal adhesions through transmembrane receptor *** particular,it has been shown that matrix elasticity can control the cell fate
A new technique was developed to solve inverse kinematics based on quadratic minimization. Firstly the inverse kinematic problem was formulated as a quadratic minimization problem through the constitution of a quadrat...
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A new technique was developed to solve inverse kinematics based on quadratic minimization. Firstly the inverse kinematic problem was formulated as a quadratic minimization problem through the constitution of a quadratic objective function derived from quaternion based kinematic description, then a new technique is developed to solve the quadratic minimization problem. The iteration procedures of the new technique are organized in two main phases: compute the search direction based on dynamic system synthesis; seek for acceptable step along the search direction. Numerical examples showed that inverse kinematic solutions can be delivered in a robust and time-efficient way, to meet the requirements coming across in the application field of every daily living support.
The integration of wind turbines into modern power grids has significantly increased during the last decade. The wind turbine equipped with full converter based wind energy Conversion System (FCWECS) represented about...
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The integration of wind turbines into modern power grids has significantly increased during the last decade. The wind turbine equipped with full converter based wind energy Conversion System (FCWECS) represented about 20.3% of the worldwide total wind capacity in 2003. Since FCWECS is equipped with a voltage source inverter (VSI), it is vulnerable that misfire and fire-through may occur within the VSI switches. In this paper, impact of these switching malfunctions on FCWECS performance is investigated and discussed. Detailed simulations of the system under study are carried out using Matlab/Simulink to highlight the influence of these converter internal faults on PCC voltage, DC link voltage and shaft speed, as well as generator active and reactive power. Furthermore, compliance of the FCWECS with Spain fault ride through (FRT) grid codes is also investigated.
Variable speed wind turbine generators installation has been significantly increased worldwide in the last few years. Voltage sag at the grid side may call for the disconnection of the wind turbine from the grid as un...
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Variable speed wind turbine generators installation has been significantly increased worldwide in the last few years. Voltage sag at the grid side may call for the disconnection of the wind turbine from the grid as under such faults it may not comply with the recent developed grid codes for wind energy conversion systems (WECS). In this paper, a Unified Power Flow Controller (UPFC) is applied to improve the low voltage ride through (LVRT) capability of doubly fed induction generator (DFIG)-based WECS during voltage sag at the grid side. Simulation is carried out using MATLAB/Simulink software. Results show that UPFC can significantly improve the LVRT capability of DFIG-based WECS and hence maintaining wind turbine connection to the grid during certain levels of voltage sag at the grid side.
A new interfacing device that enables intuitive operation of a wheelchair mounted robotic arm is proposed. Three kinds of physical signals: jaw movement, breathing strength and head movement are captured using this de...
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ISBN:
(纸本)9781467321259
A new interfacing device that enables intuitive operation of a wheelchair mounted robotic arm is proposed. Three kinds of physical signals: jaw movement, breathing strength and head movement are captured using this device, and then be used to drive motion primitives of robotic arm in an intuitive way. This device is designed to operate in a mouth-only manner, thus enables usage for the upper limb disabled. Experiments are also conducted making use of this device and wheelchair mounted robotic arm to complete tasks in activities of daily living.
In this paper, we describe the motion control for a personal mobility robot (PMR) that is a wheeled inverted pendulum vehicle. The structure of the PMR consists of a seat slider and two independent leg wheels attached...
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ISBN:
(纸本)9781467317375
In this paper, we describe the motion control for a personal mobility robot (PMR) that is a wheeled inverted pendulum vehicle. The structure of the PMR consists of a seat slider and two independent leg wheels attached on either side;this enables the driver to mount the PMR by changing the vehicle's height from the squatting position to the standing position. In addition, this structure can control the roll posture of the vehicle and thus prevent the PMR from toppling over because of a short tread. The seat slider facilitates a stable pitch posture with suitable control. We present an overview of the kinematic structure, three-dimensional dynamics model, and control method based on the linear-quadratic regulator (LQR), in order to achieve stable control of the PMR.
The number of doubly fed induction generators (DFIG) connected to the existing network has increased significantly worldwide during the last two decades. This triggers off manufactures to improve the performance of DF...
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ISBN:
(纸本)9781467327275
The number of doubly fed induction generators (DFIG) connected to the existing network has increased significantly worldwide during the last two decades. This triggers off manufactures to improve the performance of DFIG through robust and reliable design. The stator in DFIG is directly connected to the grid whereas the rotor is interfaced to the grid through two voltage source converters;rotor side converter (RSC) and grid side converter (GSC), which are considered as the crux of the DFIG system. The converter stations determine the ability of wind turbine to operate optimally during wind speed fluctuation and it can provide reactive power support to the grid during grid disturbance events. The DC capacitor link between the two converters allows optimum and smooth power exchange between DFIG and the grid. Therefore, any faults within the DC link will affect the overall performance of the DFIG. This paper investigates the impact of open circuit and short circuit faults in the DC link capacitor on the dynamic performance of the DFIG. The compliance of the wind energy conversion (WEC) system with different grid codes such as those of Denmark, Spain, Nordic and Sweden under such faults is also investigated.
Nafion-clay nanocomposite membrane has been prepared by dispersing unmodified and acid activated Laponite XLS in Nafion 20% dispersion. The resulting membranes possess better proton conductivity and mechanical strengt...
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ISBN:
(纸本)9783037853160
Nafion-clay nanocomposite membrane has been prepared by dispersing unmodified and acid activated Laponite XLS in Nafion 20% dispersion. The resulting membranes possess better proton conductivity and mechanical strength as compared to the virgin membrane. Acid activation of the nanoclay leads to the in-situ generation of H3PO4 by the hydrolysis of the peptizer present on the surface of the nanoclay. The in-situ generated H 3PO4 helps in improving all the technical properties of the nanocomposite including the water uptake and proton conductivity of the nanocomposite, containing acid activated clay compared to the nanocomposite, containing unmodified clay. The maximum proton conductivity of 270.2 mS/cm is achieved at 110 °C for the nanocomposite membrane containing 3% acid-activated Laponite compared to 136.2 mS/cm for the virgin Nafion.
This paper presents the design, fabricate and evaluation of a Magnetic Resonance compatible finger rehabilitation device, which could not only be used as a finger rehabilitation training tool after stroke, but also to...
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ISBN:
(纸本)9781467321259
This paper presents the design, fabricate and evaluation of a Magnetic Resonance compatible finger rehabilitation device, which could not only be used as a finger rehabilitation training tool after stroke, but also to study the brain's recovery process during the rehabilitation therapy (ReT). The mechanics of this device are designed to be adjustable to different persons' finger phalanges, and also the gap between one finger to another can be easily changed. By using an ultrasonic motor as its actuator, the device has been designed to be portable, with a high torque output. In addition, the mechanical has been developed into two working models (passive and active) in order to overcome the intrinsic shortage of non-back drivability in ultrasonic motor. The result system enables the client to do extension and flexion rehabilitation exercises in two degrees of freedom (DOF) for each finger as well as one DOF motion on the thumb. Finally, experiment has been carried out to evaluate the performance of the device.
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