Fuzzy logic controller for predictive vision-based target tracking with an unmanned aerial vehicle

We present in this paper a Fuzzy Logic Controller (FLC) combined with a predictive algorithm to track an Unmanned Ground Vehicle (UGV), using an Unmanned Aerial Vehicle (UAV). The UAV is equipped with a down facing camera. The video flow is sent continuously to a ground station to be processed in order to extract the location of the UGV and send the commands back to the UAV to follow autonomously the UGV. To emulate an experienced UAVs pilot, we propose a fuzzy-logic set of rules. Double Exponential Smoothing algorithm is used to filter the measurements and give the predictive value of the errors in the image plan. The FLC inputs are the filtered errors (UGV position) in the image plan and the derivative of its predicted value. The outputs are pitch and roll commands to be sent to the UAV. We show the efficiency of the proposed controller experimentally, and discuss the improvement of the tracking results compared to our previous work.     

Dental Age Estimation Based on X-ray Images

Chronological age estimation using panoramic dental X-ray images is an essential task in forensic sciences. Various statistical approaches have proposed by considering the teeth and mandible. However, building automated dental age estimation based on machine learning techniques needs more research efforts. In this paper, an automated dental age estimation is proposed using transfer learning. In the proposed approach, features are extracted using two deep neural networks namely, AlexNet and ResNet. Several classifiers are proposed to perform the classification task including decision tree, k-nearest neighbor, linear discriminant, and support vector machine. The proposed approach is evaluated using a number of suitable performance metrics using a dataset that contains 1429 dental X-ray images. The obtained results show that the proposed approach has a promising performance.     

Investigation of a New Formula for Gurney Velocity Estimation

The formula for the analytical calculations of the shaped charge jetting parameters exhibit an explicit dependence upon the Gurney velocity of an explosive material.Many attempts have been done to approximate the characteristic constant 2E~(1/2) and to make its use more efficient.It is shown herein that the characteristic Gurney velocity parameter depends on the ratio of the Chapman Jouguet-pressure to explosive impulse ratio by the formula:2E~(1/2)=0.2415(P_(CJ)/I_(SP)ρ_0)-970.76,where PCJis the Chapman Jouguet pressure(Pa),ISPis the specific impulse of the explosive used as a monopropellant(N·s/kg)andρois the explosive density(kg/m~3).The proposed empirical formula was found to be reasonable and quite accurate approximation that can be implemented over a wide range of explosives,where the maximum deviation between the measured and the calculated Gurney velocities was nearly 6%.Besides,the proposed approach has been used analytically to calculate the jet tip velocity of a small caliber shaped charge,which is measured experimentally.The difference between the measured and the calculated jet tip velocity was only 1.6%.     

A review on zeolite imidazole frameworks: synthesis,properties, and applications

Journal of Porous Materials - Zeolitic imidazolate frameworks (ZIFs) consist of transition metal ions (Zinc or Cobalt) and imidazolate (Im) linkers in tetrahedral coordination surrounded by...     

The effect of frequency of vibration and humidity on the stick–slip amplitude

This work examines the variation of stick–slip amplitude with the variation of frequency of vibration and relative humidity on a mild steel disc. A pin-on-disc machine, developed by the authors, capable of vibrating the disc at different frequency is used for the experiments. During the experiments, normal load, speed, relative humidity and frequency of vibration were varied. The results reveal that, depending on the conditions, a different stick–slip behavior can arise in the same system. It is found that the rate of reduction of stick–slip amplitude has a particular relationship with the frequency of vibration and the relative humidity. It is also observed that the transition from irregular to regular stick–slip behavior is load dependent, while the transition from irregular to smooth sliding is load independent.     

A property-integration approach to solvent screening and conceptual design of solvent-extraction systems for recycling used lubricating oils

The significant quantities of used and discharged lubricating oils pose a major environmental problem around the world. Recently, there has been a growing interest in the sustainable usage of lubricating oils by adopting recovery, recycle, and reuse strategies. In this study, a property-integration framework is used in the optimization of solvent selection for re-refining of used lubricating oils. Property-integration tools are employed for the systematic screening of solvents and solvent blends. The proposed approach identifies the main physical properties that influence the performance of solvent(s) while extracting additives and contaminants from used lubricating oils (i.e., solubility parameter (δ), viscosity (v), and vapor pressure (p)). To identify a feasibility region for an effective solvent or solvent blend for this process, we construct a ternary diagram utilizing the property-clustering technique. The results of the theoretical approach are validated through comparison between experimental data for single solvents and for solvent blends.     

Feasibility of Neural Stimulation With Floating-Light-Activated Microelectrical Stimulators

Neural microstimulation is becoming a powerful tool for the restoration of impaired functions in the central nervous system. Microelectrode arrays with fine wire interconnects have traditionally been used in the development of these neural prosthetic devices. However, these interconnects are usually the most vulnerable part of the neuroprosthetic implant that can eventually cause the device to fail. In this paper, we investigate the feasibility of floating-light-activated microelectrical stimulators (FLAMES) for wireless neural stimulation. A computer model was developed to simulate the micro stimulators for typical requirements of neural activation in the human white and gray matters. First, the photon densities due to a circular laser beam were simulated in the neural tissue at near-infrared (NIR) wavelengths. Temperature elevation in the tissue was calculated and the laser power was retrospectively adjusted to 325 and 250 mW/cm(2) in the gray and white matters, respectively, to limit ΔT to 0.5 °C. Total device area of the FLAMES increased with all parameters considered but decreased with the output voltage. We conclude that the number of series photodiodes in the device can be used as a free parameter to minimize the device size. The results suggest that floating, optically activated stimulators are feasible at submillimeter sizes for the activation of the brain cortex or the spinal cord.     

Enhancement of Geometry and Throughput in LTE Femtocells Cognitive Radio Networks

The mutual electromagnetic interference among macro users and femto users is a challenge, when femtocells are deployed in LTE and LTE advanced systems. When the used femtocells have a closed access, the macro users, who are indoors or near to the femtocells, are prone to a severe interference from the femto access points especially, in the case of the universal frequency reuse deployment. A power control is an effective way to improve the macro users’ geometry at the expense of a drop in the femto users’ geometry and capacity. The concept of a cognitive radio is proposed, as a novel approach, to mitigate the interference and improve the macro and femto users’ geometry. The system is designed, mathematically analyzed, and simulated considering that the femto users are secondary users for the macro users. The macro users and the femto users’ throughputs of the proposed system are estimated. Comparisons among the universal frequency reuse, the power control, and the suggested approach are held. The simulation results validate the efficiency of the proposed system. The average of femto users’ throughput in the proposed system is better than the corresponding one employing the universal frequency reuse or the power control, even if only 20 % of the subcarriers are available to be accessed by the femto users. Moreover, the macro users’ throughput in the proposed system is better than the corresponding one applying the universal frequency reuse or the power control, even if only 40 % of the subcarriers are available to be accessed by the macro users.     

MERCSF-N: A program for the calculation of fast neutron removal cross sections in composite shields

An approximate method for calculating the attenuation of fast neutrons can be achieved by using the “macroscopic effective removal cross-section” concept, usually denoted by Σ_R (cm⁻¹). The conventional method for the quantitative determination of Σ_R (cm⁻¹) for fast neutrons, which has been applied for several composites based on manual calculations, has a number of restrictions; a limited number of investigated samples, a lot of time, the possibility of random errors, etc. This work deals with the development, validation and application of the macroscopic effective removal cross-section of fast neutrons [MERCSF-N] computer program for calculating Σ_R (cm⁻¹) for fast neutrons transmitted through homogeneous mixtures, composites, concretes and compounds. The required physical data representing all periodic table elements have been compiled on the basis of the recommended published data and stored in a data base file. The validity of MERCSF-N has been confirmed by comparing its predictions with previously published results, both manually calculated and measured, where a good agreement was found. In addition, the code is used for calculating the macroscopic effective removal cross-sections of steel alloy, aluminum and magnetite concrete, which have previously been measured and reported. The calculated and measured results were compared and a good agreement was noticed.