To study top-down face processing, the present study used an experimental paradigm in which participants detected non-existent faces in pure noise images. Conventional BOLD signal analysis identified three regions inv...
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The default-mode network (DMN), which is suggested to have important functions related to internal modes of cognition and increasingly implicated in brain disorders, has attracted much attention in the past few years....
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The default-mode network (DMN), which is suggested to have important functions related to internal modes of cognition and increasingly implicated in brain disorders, has attracted much attention in the past few years. Effective connectivity, defined as the influence one neuronal system exerts over another, can provide deep understanding of directed influence between brain regions in the network from the view of functional integration. Granger causality analysis is one of the conventional approaches to explore the effective connectivity in brain imaging researches. In this study, we applied Granger causality analysis to resting-state functional Magnetic Resonance Imaging (fMRI) data from 12 young subjects to explore the effective connectivity pattern of the DMN. The results demonstrated that posterior cingulate cortex (PCC), medial prefrontal cortex (MPFC) and inferior parietal cortex (IPC) were the only three regions had significant causal relationship with all other regions in more than 50% subjects and PCC was the only brain area influenced by all others while had no directed influence to others. The strong effective connectivity pattern demonstrated that PCC, MPFC and IPC were the three key regions and PCC was the convergence hub in the network. These results provide further understanding of physiological mechanism of DMN underlying internal modes of cognition.
This paper focuses on the controller design of the walking system of a power transmission line inspection robot that is redundantly actuated by two wheels. After an analysis the kinematics and dynamic model of the dri...
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Based on the analysis of the first prototype of an Assisting robotic Arm (ARA) for minimally invasive thoracic surgery, an improved design is presented. A selfgravity compensation mechanism is developed to resist join...
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A mobile mechanism with biped configuration is proposed for power transmission line inspection purpose. The wire-walking cycle of the designed mechanism composed of single-support phase and double-support phase. Durin...
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A mobile mechanism with biped configuration is proposed for power transmission line inspection purpose. The wire-walking cycle of the designed mechanism composed of single-support phase and double-support phase. During the process of single-support phase, one foot hang on line and the other foot swing from rear to front to overcome obstacles on line and realize wire-walking locomotion. The novel mechanism designing enable the centroid of the robot concentrate on the hip joint to minimize the drive toque of hip joint and keep the robot stable during the single-support phase. And the centroid of the robot will be adjusted to concentrate to the other leg to start a new single-support phase. Both the forward kinematics model and inverse kinematics model are established in this paper for motion control. The feasibility of this concept is then confirmed by designing a real wire-walking robot and by performing experiment with a simulated line environment.
This paper focuses on the controller design of the walking system of a power transmission line inspection robot that is redundantly actuated by two wheels. After an analysis the kinematics and dynamic model of the dri...
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This paper focuses on the controller design of the walking system of a power transmission line inspection robot that is redundantly actuated by two wheels. After an analysis the kinematics and dynamic model of the driven system, the controller is designed as a master-slave model to avoid the ldquoconflictrdquo between the two wheels. To effectively damp the elastic vibration caused by the flexible manipulator, the control system was decomposed into two subsystems, a slowly-changing subsystem and a fast-changing subsystem based on a singular perturbation model. A hybrid control method, consisting of a RBF adaptive PD control which was applied to slow-changing subsystem and optimal control which was applied to fast-changing subsystem was presented. The RBF adaptive algorithm can estimate the unknown resistance on-line and keep the controller stable. Simulation results prove this method to be reasonable and effective.
This note is concerned with the H-infinity deconvolution filtering problem for linear time-varying discretetime systems described by state space models, The H-infinity deconvolution filter is derived by proposing a ne...
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This note is concerned with the H-infinity deconvolution filtering problem for linear time-varying discretetime systems described by state space models, The H-infinity deconvolution filter is derived by proposing a new approach in Krein space. With the new approach, it is clearly shown that the central deconvolution filter in an H-infinity setting is the same as the one in an H2 setting associated with one constructed stochastic state-space model. This insight allows us to calculate the complicated H-infinity deconvolution filter in an intuitive and simple way. The deconvolution filter is calculated by performing Riccati equation with the same order as that of the original system.
Based on the analysis of the first prototype of an assisting robotic arm (ARA) for minimally invasive thoracic surgery, an improved design is presented. A self-gravity compensation mechanism is developed to resist joi...
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Based on the analysis of the first prototype of an assisting robotic arm (ARA) for minimally invasive thoracic surgery, an improved design is presented. A self-gravity compensation mechanism is developed to resist joint torques caused by the weight of the robot and to reduce the force exerted on the end-effector by the surgeon. With a motor built into the arm, the design of the ball-socket-joint is modified to widen the surgeon's field of view. The current pedal brake is replaced with an operating pushbutton to avoid maloperation. A control system for the improved ARA is developed. The experimental results show that the workspace and the locking torque can satisfy the basic requirements of a surgery.
Reconstructing high resolution images from compressed low resolution video is a hot issue now. In many real applications, such as surveillance users often only get low quality videos which are hard to identify interes...
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In previous papers, frequency-domain quantization noise was always treated as uniform distribution in super-resolution construction for compressed video, when at high compressed ratio, this model may introduce error. ...
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