Evaluation of superior layer configuration of titanium Ti-6Al-4V and aluminium 2024-T3 against soft projectiles

The manuscript is focussed on the prediction of superior layer configuration on titanium and aluminium plates through numerical investigations using ABAQUS/Explicit finite element software. The target plate of titanium Ti-6Al-4V (Ti) and aluminium Al 2024-T3 (Al) were studied against 7.62 mm diameter soft lead core projectiles. The Johnson-Cook (JC) material model was employed to simulate the behaviour of the target as well as projectile material. The results thus predicted from the numerical simulations in terms of deformed profile, residual velocity and ballistic limit were compared with the experimental results available in literature. Overall, the results were found in good agreement with the experimental results. The simulations were performed on the target of 10, 12.7 and 15 mm thickness with three, five and ten layers in order to predict the superior layer configuration. In the case of Ti-6Al-4V, the difference in performance between three layers and monolithic was quite high, however the use of five or ten layers of equivalent thickness is not advisable as performance is reduced. For Al2024-T3, the performance of layer targets was quite similar to that of monolithic targets. It is also observed the resistance of TiTiAl target configuration found to be better as compared to AlTiTi target configuration. It is concluded that the Al plate as back layer has more efficiency for ballistic resistance of layered configuration. It is also concluded that with respect to thickness, the capacity of titanium target is approximately 1.5 times higher than aluminium target against given lead core projectile.

Path Planning for Chainable Non-holonomic System Based on Iterative Learning Control

Non-holonomic path planning is to solve the two point boundary value problem under constraints. Since it is offline and open-loop, the path planning cannot compensate for the disturbances and eliminate the errors. To solve the problems, this paper puts forward an iterative learning control algorithm that adjusts the control parameters of the path planner online through the multiple iterative computations of the target configuration error equation, under the initial configuration error and model error, and thus enhancing the accuracy of non-holonomic system path planning. Then, a simulation experiment on path planning was carried out for a chainable three-joint, non-holonomic manipulator. The results show that the iterative learning controller can eliminate the interference of initial configuration error and model error, such that each joint can move to the target configuration.

Product Dictionary Learning-Based SAR Target Configuration Recognition

Dictionary construction is a key factor for the sparse representation- (SR-) based algorithms. It has been verified that the learned dictionaries are more effective than the predefined ones. In this paper, we propose a product dictionary learning (PDL) algorithm to achieve synthetic aperture radar (SAR) target configuration recognition. The proposed algorithm obtains the dictionaries from a statistical standpoint to enhance the robustness of the proposed algorithm to noise. And, taking the inevitable multiplicative speckle in SAR images into account, the proposed algorithm employs the product model to describe SAR images. A more accurate description of the SAR image results in higher recognition rates. The accuracy and robustness of the proposed algorithm are validated by the moving and stationary target acquisition and recognition (MSTAR) database.

SIMULATION FOR OPTIMIZING THE DESIGN OF CRYOGENIC STOPPING CELL FOR THE IGISOL FACILITY AT ELI-NP

The production of exotic neutron-rich ion beams from photofission of the actinide targets in an IGISOL facility will be studied via an experimental program that will take place at the Extreme Light Infrastructure - Nuclear Physics (ELI-NP) facility. Geant4 simulation toolkit was used for optimizing the target configuration in order to maximize the rate of released photofission fragments from targets placed in a cell filled with He gas

Location-Specific Orientation Set Is Independent of the Horizontal Benefit with or Without Object Boundaries

Chen and Cave (2019) showed that facilitation in visual comparison tasks that had previously been attributed to object-based attention could more directly be explained as facilitation in comparing two shapes that are configured horizontally rather than vertically. They also cued the orientation of the upcoming stimulus configuration without cuing its location and found an asymmetry: the orientation cue only enhanced performance for vertical configurations. The current study replicates the horizontal benefit in visual comparison and again demonstrates that it is independent of surrounding object boundaries. In these experiments, the cue is informative about the location of the target configuration as well as its orientation, and it enhances performance for both horizontal and vertical configurations; there is no asymmetry. Either a long or a short cue can enhance performance when it is valid. Thus, Chen and Cave’s cuing asymmetry seems to reflect unusual aspects of an attentional set for orientation that must be established without knowing the upcoming stimulus location. Taken together, these studies show that a location-specific cue enhances comparison independently of the horizontal advantage, while a location-nonspecific cue produces a different type of attentional set that does not enhance comparison in horizontal configurations.