Due to the increased usage of social-networking application's built-in Android devices via Wi-Fi connections, cyber-attacks are also increasing which has resulted in privacy issues. Several studies have been conducted to investigate Android devices; however, none of these studies have proposed a comprehensive Android investigation method, which begins with a man-in-the-middle attack and ending in a criminal investigation. The purpose of this research is to propose an Android forensics framework against such Wi-Fi attacks using advanced forensic extraction and analysis tools. We believe that such a framework is needed to implement guidelines for forensic examiners, especially for those who are new in the field of forensics. Furthermore, we have evaluated the employed forensic tools in terms of their effectiveness, advantages, disadvantages and limitations, and then recommended the best data extraction methods designed for Android devices.
This abstract paper discusses part of a research on digital forensics investigation of cloud based snapshots. An overview and results of both practical and theoretical assessment will be discussed.
A simplified thermal model is developed for a secondary concentrator integrated with a high-temperature open volumetric solar receiver. The secondary concentrator allows the reduction of thermal losses from the receiver by reducing the tank aperture. It is exposed to high solar fluxes, a part of which is absorbed by the reflecting material leading to elevated wall temperatures. Proper thermal management is hence required. The thermal model describes the passive cooling behavior under most extreme conditions, and is intended to help design the active cooling system. It shows a substantial reduction of active cooling requirements by the use of high-emissivity paint on the concentrator outer wall. Based on the results, suitable locations of temperature measurements are determined for the first prototype tests, which will be used for model adjustment.
This work estimates excess energy usage when cooling tower fan operates at higher speeds to compensate for the entrainment and recirculation of exhaust air caused by architectural walls around a cooling tower. Air properties (i.e. temperature and relative humidity) for both near the cooling tower, inside the walls, and away from it, outside the walls, (i.e. air properties of free stream air) were monitored and analyzed. Results show that 9% excess energy was used to overcome this increase in entering air humidity.
Vertical axis wind turbine has potential advantages for small domestic application, as they can be effectively used in urban areas where wind is intermittently unsteady and turbulent. This work highlights the progress made in the development of aerodynamic models for predicting the performance of straight bladed fixed pitch vertical axis wind turbines blade profile. An improved low fidelity blade element momentum algorithm using a hybrid database is built to investigate the performance of the turbine. This is followed by 2-D numerical investigation to compare the performance prediction capability of the CFD and mathematical model. The results show good match between the models and experimental work.
Exposure to strong solar radiation can easily result in a significant increase in temperature. However, a proper design of selective surfaces helps dissipate the absorbed heat and lower the surface temperature. This work presents an optimized design for a one-dimensional photonic structure that is capable of passive radiative cooling under direct sunlight to temperatures below ambient. An imbalance between the heat absorbed by the object and the heat emitted within the atmospheric transparency window (8 to 13 micrometers) enables the cooling. A perfectly sealed structure can achieve a net cooling power of approximately 208 W/m2, leading to a steady state temperature of 38.6?C below ambient temperature.
Introducing an absorber having patterned surface with tens of nano-meters in the feature size, can enhance the absorptance, but the fabrication process is usually complicated and cost effective for large area and mass production. Recently, an alternative approach was proposed by introducing randomly distributed nano-particles on the absorber structure to achieve similar effect due to localized surface plasmon resonance. In this study, we propose a broadband absorber by combining the ultra thin film absorber with nano particles randomly deposited on the absorber surface, where the ultra thin absorber composed of an ultra thin semiconductor layer and the metallic substrate. The absorber is premeditated by utilizing 3D simulation of FDTD. The design will be fabricated using the sputtering and thermal evaporating processes, and it will be characterized using the UV-Vis-NIR spectrophotometer and Variable Angle Ellipsometer.
Transesterification of waste oil into biodiesel is a reversible multi-reactions process which yields in a byproduct, crude glycerol. The cost of biodiesel production can have a 6.5?crease if appropriate employment of glycerol is adopted. An option would be using the byproduct as an energy source either by direct combustion, blending, steam reforming or gasification. Syngas, Carbon Monoxide (CO) and Hydrogen (H2) can be produced from gasification of glycerol. Solar assisted gasification can enhance the enthalpy of the reaction by restoring solar heat. In this work, a solar assisted gasifier is designed whereby the residual glycerol can be converted thermo-chemically into syngas. The solar energy substitutes the partial combustion that is needed for gasification; this inhibits the release of emissions resulting in cleaner syngas. Temperature, species and velocity distributions are analyzed. Results show that glycerol depletes completely almost instantly to form H2 and CO2 without a high solar irradiation.
Contributors on GitHub are diverse in terms of demography and technical level across different projects but are highly transient. Previous works have suggested that diverse communities are more productive but does not take into account the quality of the software that is produced. This paper provides an insight into the quality of software that is available using quality metrics suited for open source software (OSS) on various large projects on GitHub with high developer diversity. This study investigated more than 100 releases of 5 different Python projects and between 6800 - 20000 commits per project were validated against the more than 1300 contributor details. It was found that diversity measures were partially positively correlated to software quality. Employment diversity projected loss in software quality as diversity increases. There was good evidence that increase in location diversity and commits diversity showed an increase in software quality.
The use of bio-sensors, be it attached or embedded inside a human body, to monitor various physiological parameters is increasing at a significant rate due to continued advances in miniaturizations and materials. Testing and verification of the algorithms used in processing the physiological parameters of concern is essential, given the sensitivity of their usage. Simulation is a technique that is widely used to achieve this. However, proper test cases are required in order to carry out the simulation process. ElectroCardioGram (ECG) is one of the most commonly used and studied physiological signal, yet, algorithms that handle ECG recorded data are not being tested and verified thoroughly due to the lack of proper test cases. This paper presents a test case generation algorithm that can be used to provide ECG records for testing purposes.
