Distinct neural substrates of visuospatial and verbal-analytic reasoning as assessed by Raven’s Advanced Progressive Matrices

Recent studies revealed spontaneous neural activity to be associated with fluid intelligence (gF) which is commonly assessed by Raven's Advanced Progressive Matrices, and embeds two types of reasoning: visuospatial and verbal-analytic reasoning. With resting-state fMRI data, using global brain connectivity (GBC) analysis which averages functional connectivity of a voxel in relation to all other voxels in the brain, distinct neural correlates of these two reasoning types were found. For visuospatial reasoning, negative correlations were observed in both the primary visual cortex (PVC) and the precuneus, and positive correlations were observed in the temporal lobe. For verbal-analytic reasoning, negative correlations were observed in the right inferior frontal gyrus (rIFG), dorsal anterior cingulate cortex and temporoparietal junction, and positive correlations were observed in the angular gyrus. Furthermore, an interaction between GBC value and type of reasoning was found in the PVC, rIFG and the temporal lobe. These findings suggest that visuospatial reasoning benefits more from elaborate perception to stimulus features, whereas verbal-analytic reasoning benefits more from feature integration and hypothesis testing. In sum, the present study offers, for different types of reasoning in gF, first empirical evidence of separate neural substrates in the resting brain

Dynamic behaviors of 2-DOF axially telescopic mechanism for truss structure bridge inspection vehicle

Dynamic behaviors of the 2-DOF axially telescopic mechanism for truss structure bridge inspection vehicle is investigated. The telescopic mechanism is a combination of one vertical beam that can move axially, one constant beam perpendicularly fixed at the end of the vertical beam and one telescopic beam that can move along the axial direction of the constant beam during work. The Euler-Bernoulli beam theory is utilized to simplify the beams. The Lagrangian description is adopted to account for the coordinate for the telescopic mechanism. The equations of motion are derived using the Hamilton’s principle and decomposed into a set of ordinary differential equations by employing the Galerkin’s method. The eigenfunctions are acquired based on the boundary conditions by adopting the dichotomy method. The solutions to the equations are acquired using the Newmark-β method. Experiments are carried out to prove the validity of the theoretical model. Numerical examples are simulated to explore whether the vertical beam and telescopic beam can extend or retract synchronously and obtain appropriate beam moving strategy. The results prove that synchronous motion of the vertical beam and telescopic beam will not always lead to pronounced stronger vibration than the separate ones. On the other hand, the beam moving strategies that the telescopic beam moving before the vertical beam when they all extend out or retract back and moving after the vertical beam when one extends out and the other retracts back will effectively reduce the vibration compared with otherwise

Simulation of the lateral oscillation of rope-guided conveyance based on fluid-structure interaction

How to define the clearance between rope-guided conveyances and shaft wall reasonably has confused peers for more than one hundred years. In this paper, the fluid-structure interaction approach was used to simulate the lateral oscillations of rope-guided conveyances. With Yaoqiao vertical production shaft taken into account to validate this approach, user-defined functions coupled with ANSYS FLUENT were employed to conduct the two-dimensional numerical simulation, and the simulation results show that the lateral aerodynamic buffeting force when two conveyances pass each other is much larger than Coriolis force. What’s more important, with the lateral acceleration, velocity and displacement of the conveyances obtained, the simulation results can explain how the lateral aerodynamic buffeting force to oscillate the conveyance laterally successfully. This approach can be easily extended to three-dimensional simulations, to be more reasonable

Dynamic behaviors of 2-DOF axially telescopic mechanism for truss structure bridge inspection vehicle

Dynamic behaviors of the 2-DOF axially telescopic mechanism for truss structure bridge inspection vehicle is investigated. The telescopic mechanism is a combination of one vertical beam that can move axially, one constant beam perpendicularly fixed at the end of the vertical beam and one telescopic beam that can move along the axial direction of the constant beam during work. The Euler-Bernoulli beam theory is utilized to simplify the beams. The Lagrangian description is adopted to account for the coordinate for the telescopic mechanism. The equations of motion are derived using the Hamilton’s principle and decomposed into a set of ordinary differential equations by employing the Galerkin’s method. The eigenfunctions are acquired based on the boundary conditions by adopting the dichotomy method. The solutions to the equations are acquired using the Newmark-β method. Experiments are carried out to prove the validity of the theoretical model. Numerical examples are simulated to explore whether the vertical beam and telescopic beam can extend or retract synchronously and obtain appropriate beam moving strategy. The results prove that synchronous motion of the vertical beam and telescopic beam will not always lead to pronounced stronger vibration than the separate ones. On the other hand, the beam moving strategies that the telescopic beam moving before the vertical beam when they all extend out or retract back and moving after the vertical beam when one extends out and the other retracts back will effectively reduce the vibration compared with otherwise

Dynamic behaviors of 2-DOF axially telescopic mechanism for truss structure bridge inspection vehicle

Dynamic behaviors of the 2-DOF axially telescopic mechanism for truss structure bridge inspection vehicle is investigated. The telescopic mechanism is a combination of one vertical beam that can move axially, one constant beam perpendicularly fixed at the end of the vertical beam and one telescopic beam that can move along the axial direction of the constant beam during work. The Euler-Bernoulli beam theory is utilized to simplify the beams. The Lagrangian description is adopted to account for the coordinate for the telescopic mechanism. The equations of motion are derived using the Hamilton’s principle and decomposed into a set of ordinary differential equations by employing the Galerkin’s method. The eigenfunctions are acquired based on the boundary conditions by adopting the dichotomy method. The solutions to the equations are acquired using the Newmark-β method. Experiments are carried out to prove the validity of the theoretical model. Numerical examples are simulated to explore whether the vertical beam and telescopic beam can extend or retract synchronously and obtain appropriate beam moving strategy. The results prove that synchronous motion of the vertical beam and telescopic beam will not always lead to pronounced stronger vibration than the separate ones. On the other hand, the beam moving strategies that the telescopic beam moving before the vertical beam when they all extend out or retract back and moving after the vertical beam when one extends out and the other retracts back will effectively reduce the vibration compared with otherwise

Fault diagnosis of rotating machinery based on noise reduction using empirical mode decomposition and singular value decomposition

Vibration signals collected from a faulty rotating machine include in general impulse information reflecting fault types, irrelevant vibration components caused by other normal mechanical parts, and other environmental noise. Cleaning the obtained vibration signals can prove practical significance for the fault diagnosis of rotating machinery. To address this issue, this paper proposes a new fault diagnosis method based on noise reduction technology using empirical mode decomposition (EMD) and singular value decomposition (SVD). In this approach, EMD is first applied to decompose the collected vibration signal into a set of intrinsic mode functions (IMFs) and residual signal. Then the first several IMFs including bearing characteristic damage frequencies (CDFs) and higher frequency components are selected to do further noise reduction by SVD for features, and the other remaining decomposition components of EMD are abandoned as noise. Finally, the fault diagnosis of rotating machinery is realized by these obtained features using a support vector machine (SVM) model. Experimental results testify that the proposed method is effective for mechanical fault diagnosis

Identification and diagnosis of concurrent faults in rotor-bearing system with WPT and zero space classifiers

An effective method for identifying and diagnosing the concurrent fault combined by two or more single faults is yet to be further developed because most existing approaches focus on single faults. On the other hand, rotor-bearing system is an important part of rotating machinery. Therefore a new fault identification and diagnosis method based on wavelet packet transform (WPT) and zero space classifiers is presented in this paper. Firstly, the vibration signals collected from the rotor-bearing system are decomposed into several time-frequency compositions by WPT. Then the appropriate composition characterizing fault signatures is selected to extract features for constructing zero space classifiers. Finally, the effectiveness of the proposed method is demonstrated by an experiment carried out on a machinery fault simulator. The experimental results show that the proposed approach is feasible and effective to identify and diagnose the concurrent faults in a rotor-bearing system

The Transformation from Translucent into Transparent Rare Earth Ions Doped Oxyfluoride Glass-Ceramics with Enhanced Luminescence

Article reporting a scenario where a translucent Er3+−Yb3+ doped oxyfluoride precursor glass-ceramic (P-GC) becomes transparent with increasing crystal size and crystallinity