Research on Measurement Method of Parachute Scanning Platform Based on MEMS Device

This paper studies the measurement of motion parameters of a parachute scanning platform. The movement of a parachute scanning platform has fast rotational velocity and a complex attitude. Therefore, traditional measurement methods cannot measure the motion parameters accurately, and thus fail to satisfy the requirements for the measurement of parachute scanning platform motion parameters. In order to solve these problems, a method for measuring the motion parameters of a parachute scanning platform based on a combination of magnetic and inertial sensors is proposed in this paper. First, scanning motion characteristics of a parachute-terminal-sensitive projectile are analyzed. Next, a high-precision parachute scanning platform attitude measurement device is designed to obtain the data of magnetic and inertial sensors. Then the extended Kalman filter is used to filter and observe errors. The scanning angle, the scanning angle velocity, the falling velocity, and the 2D scanning attitude are obtained. Finally, the accuracy and feasibility of the algorithm are analyzed and validated by MATLAB simulation, semi-physical simulation, and airdrop experiments. The presented research results can provide helpful references for the design and analysis of parachute scanning platforms, which can reduce development time and cost.

Algorithm of changing digital image contrast taking into account local statistical characteristics of pixel luma distribution

The article presents the algorithm for processing digital images in order to enhance the distinguishability of its details, based on scanning motion of a small rectangular area on the pixel field, in which the contrast is changed by one of the known algorithms with the overlay on the already processed part (locally fragmented scheme). Different variants of inclusion of television algorithm of contrast changing in this scheme are considered. The results of processing according to the local-fragmented scheme in comparison with the global application of the television algorithm are investigated. It is shown that the proposed approach makes it possible to achieve a much greater increase in the distinguishability of details than in the global application of the television algorithm.

Advertising Positions: Data Portraiture as Aesthetic Critique

Advertising Positions integrates 3D scanning, motion capture, novel image mapping algorithms and custom animation to create data portraits from the advertisements served by online trackers. Project volunteers use bespoke software to harvest the ads they receive over months of browsing. When enough ads have been collected, the volunteer is interviewed, 3D scanned and motion captured. Each ad is then mapped to a single polygon on the textured skin of their virtual avatar. Outcomes have been displayed as 2D/3D images, animations and interactive installations.

Structure Design of Large Travel One-Arm Bridge Type Z-Axis Nano-Positioning Stage

In some areas such as micro-mechanical, ultra-precision machining, nanotechnology, the high-precision positioning and very fine vertical scanning motion are needed urgently. Therefore, the Z-axis micro-displacement driving control technology has become the key technology in these areas. The piezoelectric ceramics actuator and stepper motor were integrated into hybrid linear actuator in Z-axis nanopositioning stage, and this can simplify the structure of the drive system. By calculating the gravity center of the vertical scanning system, and using single counterweight, a new one-arm bridge type structure was built. Appropriate tension and current sensors were also equipped in order to real-time monitor the drive status. It is feasible to balance the weight with this simplified system structure, and also guarantee the driving control accuracy of nanopositioning stage. Besides, in the structural design, the Abbe error can be reduced greatly by placing the stage center, grating ruler and displacement measurement centerline on the same line with grating reading head. The driving travel of nanopositioning stage is 150mm, and driving resolution is 1nm. The designing method introduced gives a scientific method and practical reference for the development of z-axis driving control system.

Head motion in children with ADHD during resting-state brain imaging

Although head motion during scanning has been largely considered to reflect simply technical artifacts, there is growing evidence showing that the variable of head motion reflects valuable information regarding individual’s psychological and/or clinical factors. Detailed studies would not only help to deal with the head motion biases, but they also help researchers in understanding the mental disorders. In this study, children with ADHD and demographically-matched typically developing control (TDC) participants underwent rs-fMRI examination without any specific task, and six mean single head motion parameters (three translational and three rotational) and a summary motion index for each participant were obtained. We found that patients with ADHD showed specific patterns of head motion during scanning: motion was significantly increased in the ADHD group, which was mainly contributed by the motion around and along the superior-to-inferior direction. Furthermore, the cross-validation classification analyses showed that the head motion could accurately distinguish children with ADHD from the healthy controls. These results suggest that head motion during scanning reflects useful information about the participants and accounting for head motion from MRI data may be helpful for ADHD diagnosing and treatment with neuroimaging.

Head motion in children with ADHD during resting-state brain imaging

Although head motion during scanning has been largely considered to reflect simply technical artifacts, there is growing evidence showing that the variable of head motion reflects valuable information regarding individual’s psychological and/or clinical factors. Detailed studies would not only help to deal with the head motion biases, but they also help researchers in understanding the mental disorders. In this study, children with ADHD and demographically-matched typically developing control (TDC) participants underwent rs-fMRI examination without any specific task, and six mean single head motion parameters (three translational and three rotational) and a summary motion index for each participant were obtained. We found that patients with ADHD showed specific patterns of head motion during scanning: motion was significantly increased in the ADHD group, which was mainly contributed by the motion around and along the superior-to-inferior direction. Furthermore, the cross-validation classification analyses showed that the head motion could accurately distinguish children with ADHD from the healthy controls. These results suggest that head motion during scanning reflects useful information about the participants and accounting for head motion from MRI data may be helpful for ADHD diagnosing and treatment with neuroimaging.

Research on the Aero Dynamicity of Steady Wing of Non-Parachute Terminal Sensitive Projectile

The stable wing of non-parachute terminal sensitive projectile (TSP) is a plate wing with two bent angles at edges of the plate wing, thus it looks like an S. Wings of this shape slow the TSP down during its falling process which provides asymmetric forces for it. Then stable scanning motion is realized. This paper established unsteady model of the S wing of the TSP based on CFD/CSD fluid structure interaction (FSI) and analyzed the aerodynamic characteristics of both rigid wing and elastic wing. The results show that the plate which bends towards the windward has the largest deformation. The drag coefficient of the elastic wing is smaller than that of rigid wing at a smaller attack angle while bigger at a larger attack angle. The displacement of S wing increases while the incoming velocity increases and has a tiny interaction relationship with attack angle.