Sensors play a vital role in the smartphone for sensing-enabled mobile activities and applications. Different sources, like mobile applications and websites, access the sensors and use them for various purposes. The user needs permission to access the permission-imposed sensors. Using the generic sensor application programming interface, the user can access the no-permission-imposed sensors directly without any permission. Attackers target these sensors and make the smartphones vulnerable at the application, device and network levels. The attackers access the sensor’s information and use it for different purposes like personal identification number identification and user personal information theft. This paper presents STMAD, a novel allowlist-based intrusion prevention system to mitigate sensor-based threats on smartphones by detecting malicious access of an attacker through different channels. STMAD functions as a lightweight preventive mechanism for all sensors on the smartphone and preventing attackers from accessing sensors maliciously. The experimental results show that the proposed defense mechanism is more efficient and consumes minimal overhead. An informal security analysis also proved that the STMAD protects against various attacks.
Processing of edible sesame flour involves use of hot lye treatment of the seed for dehulling followed by drying, screw pressing,
and solvent extraction. The effect of such processing on protein quality, especially lysine availability has been studied.
The enzymatic digestibility of protein is improved as a result of dehulling, and lysine present in the flour exhibits remarkable
stability to heat treatment, the maximum losses being less than 15% even under drastic conditions of heat treatment of the
flour (1 kg/cm2 for 60 min). Supplementation of the flour with lysine at an optimal level of 1.25 g L-lysine HCl/100 g flour enhances the
nutritive value of protein, making it comparable to that of milk powder. 相似文献
We report here the results of our physical modeling study of the equal channel angular pressing process using two-colour constituent plasticine workpieces in a metallic die. The workpieces, usually called billets, are made up of discs as well as spherical balls. They are deformed repeatedly with and without changing the orientation between successive passes. Both square and round dies with inner channel intersection angle of 90° are used. The flow patterns are revealed by sectioning the billet after a requisite number of passes. Thorough mixing of the two constituents with a drastic reduction in the section size of each constituent of the plasticine workpiece was observed after 15 passes. The initial shape of the constituents of the billet does not affect the final flow pattern of the microstructure. Material accumulation of the two colour constituents of plasticine was observed in some regions of the billet along the central region at a low and intermediate number of passes. 相似文献
Virtual reality (VR), provides the user with an ego-centred human-computer interaction environment by presenting the data as a computer-generated 3D virtual environment. This enables the user to be immersed in this world via user position tracking devices and to interact with the data objects in the world in intuitive ways. This paper describes a selection of VR simulations for engineering applications implemented in CLRC which demonstrate the potential of VR interaction techniques to offer quicker and possibly better understanding of spatial relationships and temporal patterns inherent in large data sets. Two of the case studies have been implemented to support engineers communicate and review their designs with scientists, managers and manufacturers and to plan their assembly and maintenance work in hazardous physical environments. The other two applications are visualisation case studies based on data sets generated by computational engineering simulations. The case studies are real world applications, involving end-users of large or complex data sets. Insight gained into the user interaction requirements through the implementation and user comments is guiding ongoing research and development activity and this is discussed briefly. 相似文献
The paper presents the equipment of the up-to-date photo laboratory set developed and delivered by the closed joint stock company "Roentgen-Komplekt" jointly with the closed joint stock company "Amico" (Russia). Devices for manual development of X-ray films, drying cabinets, negatoscopes, a lantern, developing frames, a laboratory assistant's X-ray table, etc. are described. 相似文献
The presence of a few inverted or poor-quality mesh elements can negatively affect the stability, convergence and efficiency of a finite element solver and the accuracy of the associated partial differential equation solution. We propose a mesh quality improvement and untangling method that untangles a mesh with inverted elements and improves its quality. Worst element mesh quality improvement and untangling can be formulated as a nonsmooth unconstrained optimization problem, which can be reformulated as a smooth constrained optimization problem. Our technique solves the latter problem using a log-barrier interior point method and uses the gradient of the objective function to efficiently converge to a stationary point. The method uses a logarithmic barrier function and performs global mesh quality improvement. We have also developed a smooth quality metric that takes both signed area and the shape of an element into account. This quality metric assigns a negative value to an inverted element. It is used with our algorithm to untangle a mesh by improving the quality of an inverted element to a positive value. Our method usually yields better quality meshes than existing methods for improvement of the worst quality elements, such as the active set, pattern search, and multidirectional search mesh quality improvement methods. Our method is faster and more robust than existing methods for mesh untangling, such as the iterative stiffening method. 相似文献
This study describes the synthesis of a free-standing nanogold membrane by the spontaneous reduction of aqueous chloroaurate ions by the diamine molecule DAEE at a liquid-liquid interface. The free standing nanogold membrane, provides a biocompatible surface for the immobilization of proteins. F-Protease (F-Prot) was then bound to the nanogold membrane via interaction with the gold nanoparticles leading to a new class of biocatalyst. A highlight of the new biocatalyst wherein the enzyme is bound to the nanogold membrane is the ease with which separation from the reaction medium may be achieved by simple filtration. In relation to the free enzyme in solution, the F-Prot in the bioconjugate material exhibited a slightly higher biocatalytic activity and significantly enhanced pH and temperature stability. The F-Prot nanogold membrane bioconjugate material also exhibited excellent biocatalytic activity over ten successive reuse cycles. 相似文献
Spider silk is being viewed with interest by materials scientists due to its excellent resilience and mechanical properties. In this paper we show that spider silk is an excellent scaffold for the one-step synthesis and assembly of gold nanoparticles. Formation of a gold nanoparticle-spider-silk bioconjugate material is accomplished by simple reaction of the fibers with aqueous chloroauric acid. The gold nanoparticles thus formed are strongly bound to the spider-silk fiber surface enabling study of the electrical properties of the nanobioconjugate. Using the well-known contraction/expansion behavior of the fibers in solvents of varying polarity, we show that exposure of the gold nanoparticle-spider silk bioconjugate to vapors of methanol and chloroform leads to changes in electrical transport through the nanoparticles and thus, the possibility of developing a vapor sensor. The bioconjugate shows excellent response time and cycling efficiency to methanol vapors. The activation energy of electron transport from one gold nanoparticle to another in the nanobiocojugate was determined from temperature-dependent electron-transport measurements to be approximately 1.7 eV. 相似文献