We live in a smart society that tremendously relies on the smooth and secure functioning of the critical infrastructure and its services and the crucial processes in the critical infrastructure are in turn, reliant on the cyber-physical and the industrial control systems that the infrastructure is comprised of. For the past decades, securing the cyberphysical and industrial control systems has been of top priority as few attacks have been reported publicly. The main fact to take note of is that these systems were deployed over decades ago and were developed with the sole intention of monitoring and controlling processes in critical infrastructure without considering the security requirements. So there is an urgent need of protecting the cyber-physical and industrial systems from external vulnerabilities. Also, the systems are prone for various cyber threats that could compromise their functions and jeopardise the framework of the critical infrastructure.
In this paper, we demonstrate how to assess the security health of a given Wi-Fi hotspot. We accomplish this by using HosTaGe honeypot for mobile devices which has the ability to detect various malicious activities. In this paper, we show how HosTaGe can be configured to catch and report abnormal and suspicious activities, or simply alerting users of Android smartphones when there are imminent threats in the wireless network.
In digital forensics, carving of video files is an important process to recover video evidence of several criminal cases. The traditional carving techniques recover video files based on their file structure. However, these techniques fails in the cases if the file is split into several fragments over storage media. In this paper we present the fragmented video file carving Framework. This framework consist of three stages which are Identification, weight assessment and reassembly. The identification component presents a method to recover fragmented video. The purpose of weight assessment is to assign weight of adjacency between video fragments. Using these weights we propose to adopt a greedy to reassemble these fragment into correct sequence that produce playable video file.
This paper presents the influence of interaction parameters in the simulations of the thermomechanical behavior of Iron-based shape memory alloys. Such parameters account for the interactions between martensite variants, between plastic slips, and between martensite variants and plastic slips. The constitutive equations of the model were derived within the framework of generalized standard materials. The model parameters were first calibrated at different temperatures.The effects of their variation in the macroscopic stress, inelastic strain recovery and nonlinearity of the model were then explored. The simulation results exhibited steeper slope of the stress-strain curves for higher values of the hardening parameters, and increasingly linear curves for higher value of the interaction exponents.
Biodiesel is an alternative and sustainable fuel that can reduce the dependence on fossil diesel. It is being promoted even in developing counties like Indonesia, Brazil. Production of biodiesel through transesterification is a slow reaction which is conventionally carried out in a mechanically stirred batch process. An advanced method to achieve high yield quality in less time is sonication of the reaction in an integrated continuous process. In this work, a cylindrical reactor is considered in which reactant mixture will be circulated and sonicated by a sonotrode type ultrasound equipment. To simulate the sonication effect the linear, time independent wave equation is solved using a complex wave number for bubble attenuation. To account for the chemical reactions, laminar reacting flow is solved using Navier-Stokes equations and transport equation for dilute species. A logical reaction rate coupling model evaluates the kinetics of the reaction, used for judging the reactor design.
Hydrodynamics in annular fluidized bed (AFB) reactor is very complex as there are two wall surfaces with which the particles interact and fall along. Therefore, in this study the effect of wall boundary condition i.e. the specularity coefficient and restitution coefficients of interaction between particle-wall and particle-particle is investigated. Simulations are performed using an open source code MFiX by employing the two-fluid model which considers solid and gas as the interpenetrating continua where the solid viscous stress tensor is calculated using the kinetic theory of granular flow. A circumferential core-annulus structure is observed in the reactor. The hydrodynamics of AFB is very sensitive to all the coefficients. Lower specularity coefficient values produce higher particle velocities in the bed as there is reduced loss of tangential momentum to the walls. Particle-wall restitution coefficient has a very minor effect on the solid particle velocity consistent with the previous studies on cylindrical reactors.
Impinging jets disintegration is a widely used process in various applications like propulsions, especially in propellant rocket engines. However, no complete agreement has been reached about liquid jets breakup mechanisms. This research involves a novel air assisted atomizer configuration consisting of two water jets and an impinging air jet, which has scarcely been investigated. High speed camera was used to visualize the disintegration phenomena. The effects of water and air jets velocities on the breakup performance were studied. The breakup phenomena were analyzed and the spray angle was obtained. Besides, Phase Doppler Anemometry (PDA) was utilized to measure the size generated droplets 75mm downwards the impinging point. The results indicated that the existence the air jet improved the atomization performance significantly. In conclusion, this study showed the performance of the novel atomizer, and provided information for related simulation works.
Ultrasonic metal welding (USMW) is a solid-state bonding process highly applicable to join lightweight alloy materials. The strength of parts welded using this process varies depending on the used control parameters such as welding time, power, clamping pressure, etc. This study is an experimental and numerical investigation of the ultrasonic welding process for aluminum sheets with thickness of 1.4 mm. Experiments were conducted to test the effect of welding time and power on the weld quality and weld strength while measuring the temperature distribution. As a future step it is possible to use the experimental measured temperature as an input to heat flux models in finite element analysis (FEA) to simulate the USMW process and to develop a model that would evaluate the weld quality by predicting the maximum failure load under lap-shear test.
Results of a computational and experimental study of laminar, non-premixed counterflow methane diffusion flame under the effect of the electric field are described. The flame position could be manipulated experimentally through control of the applied electric field independently of variations in the momentum of the reactant stream. The governing equations were solved using the ANSYS-Fluent platform by implementing the GRI-Mech 3.0 mechanism that was complemented by three reactions generating three chemi-ions: H2O+, HCO+ and e-. The electrostatic effect was coupled with the governing equations by introducing the appropriate terms to the momentum, species evolution, and energy equations of ANSYS-Fluent solver.
Wind power becomes an increasingly significant source of generation in power systems and clean energy initiatives. Consequently, wind speed forecasting plays an important role in the wind energy industry in terms of wind turbine operation, wind energy scheduling, wind energy project design and assessment, efficient energy harvesting, and so on. In this work, we will approach different univariate and multivariate parameter estimation models for the discrete-time wind speed. Comprehensive evaluation of the different models for forecasting the mean and volatility of Abu Dhabi International Airport, UAE wind speed is undertaken.
