The Military Technical CollegeJournal of Engineering Science and Military Technologies2357-09541220171001Multi-UAV Tactic Switching via Model Predictive Control and Fuzzy Q-Learning4457414910.21608/ejmtc.2017.437.1012ENAhmed TaimourHafezHead of Aircraft Armament DepartmentSidney N.GivigiRoyal Military College of CanadaShahramYousefiMohamadIskandaraniRoyal Military College of CanadaJournal Article20171102Teams of cooperative Unmanned Aerial Vehicles (UAVs) require intelligent and flexible control strategies to allow the accomplishment of a multitude of challenging group tasks. In this paper, we introduce a solution for the problem of tactic switching between the formation flight tactic and the dynamic encirclement tactic for a team of 𝑁 cooperative UAVs using a predictive decentralize control approach. Decentralized Model Predictive Control (MPC) is used to generate tactics for a team of 𝑁 UAVs in simulation and real-world validation. A high-level Linear Model Predictive Control (LMPC) policy is used to control the UAV team during the execution of a desired formation, while a combination of decentralized LMPC and Feedback Linearization (FL) is applied to the UAV team to accomplish dynamic encirclement. The decision of switching from one tactic to the other is derived by a fuzzy logic controller, which, in its turn, is derived by a Reinforcement Learning (RL) approach. The main contributions of this paper are: (i) solution of the problem of tactic switching for a team of cooperative UAVs using LMPC and a fuzzy controller derived via RL; (ii) simulations demonstrating the efficiency of the method; and (iii) implementation of the solution to on-board real-time controllers on Qball-X4 quadrotors.https://ejmtc.journals.ekb.eg/article_4149_9ba17acba793c36148f4a3ab0db57bf3.pdfThe Military Technical CollegeJournal of Engineering Science and Military Technologies2357-09541220171001An Experimental Assessment of Unsteady Forces on a Plunging Airfoil Oscillating in Stationary Fluid at High Frequencies5871415110.21608/ejmtc.2017.391.1009ENMohamed YehiaZakariaAerospace DepartmentD. A.PereiraMSc. in Engineering, University of Sa˜o Paulo (EESC/USP), BrazilMuhammadHajjProfessor, Biomedical Engineering and Mechanics, Norris HallSaad A.,RagabProfessor, Biomedical Engineering and Mechanics, Norris HallF. D.MarquesAssociate professor, University of Sa˜o Paulo (EESC/USP), BrazilJournal Article20171102Experiments were conducted to measure the unsteady plunging forces on a NACA- 0012 airfoil at zero undisturbed flow velocity. The aim is to investigate the vari- ation of the added forces associated with high oscillation frequencies at various angles of attack. Data of the measured forces are presented and compared with the predicted forces from potential flow approximations. The results show a signifi- cant departure from those estimates particularly at high frequencies. The results show that the measured added forces varies in a cubic manner with the frequency of oscillations. These results were revealed to be different in its formulation com- pared to the formulation using Stokes flow. The measured forces were proposed to be a function of the local acceleration and drag forces that is function of the square of the wing section velocity.https://ejmtc.journals.ekb.eg/article_4151_9e3e930908a7ebad7a955a647217f2b5.pdfThe Military Technical CollegeJournal of Engineering Science and Military Technologies2357-09541220171001Thermal Behaviour Assessment For The Different Building Envelope Parts In Egypt Under Climate Change Scenarios7285415210.21608/ejmtc.2017.396.1003ENMohamed M.MahdyDepartment of Architecture, Military Technical Collage, Cairo, Egypt.MohamedBarakatDepartment of Architecture, Military Technical Collage, Cairo, Egypt.Journal Article20171102This paper presents a comprehensive evaluation for (of) the results of a recent research effort concerning thermal comfort in residential buildings in Egypt. The energy performance and thermal comfort were considered based on the instructions of the Egyptian Residential Energy Code (EREC) to improve the efficiency of energy use. The conclusions of the aforementioned research on the building envelope (walls / fenestration) were tested together to make sure (prove or demonstrate or verify) that the use of what seems to be the best solutions for external walls (solid part) in addition to the best solutions for fenestration (openings), will results result in a better overall performance in energy consumption and thermal comfort, than (when) implementing (only) one of the two choices. To attain that, two (mixed-mood) [heating, ventilation and air conditioning (HVAC)] case study buildings were dynamically simulated in three dominant Egyptian climatic zones, using current climate conditions (2002) in addition to three other morphed climate change scenarios (2020, 2050 and 2080). Achieving the required rates for thermal comfort, and acquiring (securing) long term financial gains were the basic elements of the evaluation. The results provide what seems to be a functionally and financially successful combination to fulfil the evaluation elements.https://ejmtc.journals.ekb.eg/article_4152_de78a4f44f71e81d0ebb094afefe32da.pdfThe Military Technical CollegeJournal of Engineering Science and Military Technologies2357-09541220171001Sizing of a Photovoltaic System for a House in Qassim, Saudi Arabia8690415310.21608/ejmtc.2017.743.1034ENSaif AlharbiGraduateDepartment of Electrical and Computer Engineering, Memorial University, CanadaIqbal M.TDepartment of Electrical and Computer Engineering, Memorial University, CanadaJournal Article20171102Consumption of electricity in the Middle East is quite high due to the cooling needs in each home. However, Saudi Arabia has high solar energy resources that could be used to meet all home energy needs. In this project, a solar energy system is designed using BEopt and Homer softwares. BEopt was used to build a thermal model for an actual house in Qassim, Saudi Arabia, to stimulate the hourly kilowatt electricity consumption. Mathematical equations have been used to calculate the necessary photovoltaic and battery size. The collected data and BEopt results are used by Homer software to design various options for a photovoltaic system (PV). Results indicate that a 18.85 kW PV system, 52 batteries 200<br />Ahr (Ah) each and a 10kW inverter can meet all house energy needs.https://ejmtc.journals.ekb.eg/article_4153_3107edb1b24038b3d15e8e688faeb5d3.pdfThe Military Technical CollegeJournal of Engineering Science and Military Technologies2357-09541220171001Characterization of 3D Printed Stainless Steel SS316L Powders Joined by TIG-, Plasma- and Laser Welding9195415410.21608/ejmtc.2017.1052.1045ENM.HarrazEngineering Materials, Faculty of Engineering Materials Science, The German University in Cairo, New Cairo, EgyptN.El-Mahallawy,Engineering Materials, Faculty of Engineering Materials Science, The German University in Cairo, New Cairo, Egypt,K.Abd ElghanyLaser and Additive Manufacturing Lab, Central Metallurgical Research and Development Institute (CMRDI), Helwan, EgyptM.SchleserFH Aachen, University of Applied Sciences, D-52064 Aachen, GermanyH.PalkowskiIMET, Institut fuer Metallurgie, TU Clausthal, GermanyAnkeKlingnerThe German University in CairoJournal Article20171102Additive manufacturing or 3D printing is becoming more and more common in industry fabrication, especially for spare parts which cannot be found easily on the local market and for tailor made parts. For large parts and due to its size limitations, it is sometimes required to join 3D printed parts with other 3D printed parts or conventionally produced parts. In this work, 3D printed flat plates 4mm thick were prepared by direct laser sintering of SS316L powders. Mechanical properties and microstructure were investigated. Elongation and maximum tensile stress of 3D printed flat plates are with 1.3% and 704MPa smaller than the values 2% and 1241MPa of cold-rolled SS316 parts. The 3D printed flat plates were joined by welding using TIG welding, plasma welding and laser welding. The welded joints were tested for their mechanical properties and microstructure. For the used welding conditions, the fracture occurred outside the weld zone. The maximum stress of the welded parts is 65-80% of 3D printed flat plates. The elongation of the welded parts is above 3%.https://ejmtc.journals.ekb.eg/article_4154_82826d094e5bcd5af7db7f3179c1cfcd.pdfThe Military Technical CollegeJournal of Engineering Science and Military Technologies2357-09541220171001Spatial Signature Modulation: A Novel Secure Modulation Approach for MIMO Wiretap Channel96107415510.21608/ejmtc.2017.1438.1055ENAmrAbdelazizDepartment of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio 43201,0000-0003-3709-3653Ashraf D.ElbayoumyDepartment of Electrical Engineering, Military Technical College, Cairo, Egypt.Journal Article20170805Security in physical and application layers have been always thought of as a complementary paradigm. In this paper, we argue that potential cooperation between physical and application layers provides several advantages and unique features that are not available in each paradigm by itself. The problem of exchanging confidential messages between nodes, A and B, in the presence<br />of an active adversary, E, over an insecure MIMO channel is considered. We introduce a double layer spatial signature modulation (SSM) in which the transmitted information is conveyed into the spatial signature of the transmitting antenna array observed by the intended receiver. Meanwhile, any other eavesdropper does not share the same bearing angle of the legitimate receiver obtains infinitesimally small amount of information. Further, to establish a secure link, A and B are required to share a secret common information prior to communication while keeping E ignorant about it. To that end, we introduce a novel physical layer assisted secret key agreement (SKA) protocol that leverages the cooperation between physical and application layer security. Angle of Arrival (AoA) and Angle of Departure (AoD) are physical layer parameters that can be exploited not only for their well performance at low SNR, but also for their contextual meaning that provides security advantages. In the proposed SKA protocol, AoA is explored as a physical mean for message source authentication, meanwhile, AoD is used as a common source of randomness in a smart signal processing approach to generate secret key bits without any extra communication overhead. We show that E can be kept ignorant about the generated key bit stream conditioned on its physical location. This work introduces the notion of physical hardness to an adversary pursuing either active or passive strategy. After establishing a secret common information, we show that the continuous use of AoA as a mean for message source authenticity provides a considerable advantage against active adversary during the message exchange phase. Extending the proposed scheme to a mobile communication environment is also provided. Finally, quantitative analysis for the security gain due to the potential cooperation between physical and application layer security is developed..https://ejmtc.journals.ekb.eg/article_4155_4d9389ef2c19d375a08ca31a93ea4e43.pdf