Development of UCAV fleet autonomy by reinforcement learning in a wargame simulation environment

In this study, we develop a machine learning based fleet autonomy for Unmanned Combat Aerial Vehicles (UCAVs) utilizing a synthetic simulation-based wargame environment. Aircraft survivability is modeled as Markov processes. Mission success metrics are developed to introduce collision avoidance and survival probability of the fleet. Flight path planning is performed utilizing the proximal policy optimization (PPO) based reinforcement learning method to obtain attack patterns with a multi-objective mission success criteria corresponding to the mission success metrics. Performance of the proposed system is evaluated by utilizing the Monte Carlo analysis in which a wider initial position interval is used when compared to the defined interval in the training phase. This provides a preliminary insight about the generalization ability of the RL agen

A new nonlinear lifting-line method for aerodynamic analysis and deep learning modeling of small UAVs

In this work, a computationally efficient and high-precision nonlinear aerodynamic configuration analysis method is presented for both design optimization and mathematical modeling of small unmanned aerial vehicles (UAVs). First, we have developed a novel nonlinear lifting line method which (a) provides very good match for the pre- and poststall aerodynamic behavior in comparison to experiments and computationally intensive tools, (b) generates these results in order of magnitudes less time in comparison to computationally intensive methods such as computational fluid dynamics (CFD). This method is further extended to a complete configuration analysis tool that incorporates the effects of basic fuselage geometries. Moreover, a deep learning based surrogate model is developed using data generated by the new aerodynamic tool that can characterize the nonlinear aerodynamic performance of UAVs. The major novel feature of this model is that it can predict the aerodynamic properties of UAV configurations by using only geometric parameters without the need for any special input data or pre-process phase as needed by other computational aerodynamic analysis tools. The obtained black-box function can calculate the performance of a UAV over a wide angle of attack range on the order of milliseconds, whereas CFD solutions take several days/weeks in a similar computational environment. The aerodynamic model predictions show an almost 1-1 coincidence with the numerical data even for configurations with different airfoils that are not used in model training. The developed model provides a highly capable aerodynamic solver for design optimization studies as demonstrated through an illustrative profile design example

WITHDRAWN: Frequency and voltage dependent profile of dielectric properties, electric modulus and ac electrical conductivity in the PrBaCoO nanofibers capacitors

This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause.The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy

Effect of Co-60 gamma-ray irradiation on electrical properties of Ti/Au/GaAs1-xNx Schottky diodes

Current-voltage (I-V), capacitance-voltage-frequency (C-V-f) and conductance-voltage-frequency (G/ω-V-f) measurements at room temperature are used to study 50 kGy 60Co γ-ray electrical properties irradiation dependence of Ti/Au/GaAs1−xNx Schottky diodes with 0.2%; 0.4%; 0.8% and 1.2% nitrogen dilution. This γ-ray irradiation induces a permanent damage that has increased ideality factor and series resistance for all samples. It was accompanied by a decrease in Schottky barrier height with nitrogen content up to 0.4%N and remained constant thereafter. Radiation was also found to degrade the reverse leakage current. At high frequency (1 MHz), capacitance and conductance decreased after radiation due to a decrease in net doping concentration. Interface state density and series resistance were determined from C-V-f and G/ω-V-f characteristics using Hill-Coleman methods. Interface states density exponentially decreased with increasing frequency confirming the behavior of interface traps response to ac signal. Series resistance increases after irradiation is attributed to carrier's removal effect and mobility degradation. It has two peaks in the accumulation and inversion region for some diodes (0.4%N, 0.8%N). γ-ray irradiation produced traps levels and recombination centers that reduce relaxation time. An increase in %N content can impede irradiation damage with even some compensation when the percent of diluted nitrogen is high (1.2%N)

Identification of sentence types for writing skill in teacher education

This research aims to explore the ability of English majors to identify the four basic types of sentences. English language has four types of sentences, each kind of sentence for different kinds of messages. Sentences are combinations of words that express complete thoughts. Sentences are basic building blocks of writing and communication; therefore, breaking our ideas into sentences is essential for clear communication. In traditional grammar, the four basic types of sentence structures are the simple sentence, the compound sentence, the complex sentence, and the compound-complex sentence, whose identification by the non-native student teachers may be problematic. It’s crucial that English majors recognize word order and sentence types in English to improve their academic writing skills, and hence the identification of four types of sentences by English majors is a must. In this research 35 English majors with low intermediate background were given a pretest of 20 questions in terms of a multiple-choice test to measure their initial success at the beginning. After 6 hours of intense sentence structure recognition studies, they were given the same pretest, after al elapse of 15 days, as the posttest to determine their final success on the discrimination of simple, compound, complex sentences, and compound-complex sentences from each other. After the collection of data from pre-test and post-tests, the data were analyzed by SPSS 21. It was discovered that while pre-test’s was 23%, the mean score of the post-test came up to be 56 %, the percentage of ascent being % 23. © 2019 JLLS and the Authors - Published by JLLS

A communication-channel-based representation system for software

We observed that before initiating software development the objectives are minimally organized and developers introduce comparatively higher organization throughout the design process. To be able to formally capture this observation, a new communication channel representation system for software is developed in three stages a) set-theoretical representation of software design, b) mapping of software design to a communication channel formalism, and c) hierarchical decomposition leading to higher organization. This new representation system provides a better understanding of the software design by introducing a stepwise entropy reduction notion to the design process. Formal representation of hierarchical decomposition of software and entropy-reduction view of software design provides a stronger bridge between established engineering methods and software design, opens up new possibilities in software research, connecting software with information and coding theory