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71.
Network security devices such as firewalls and intrusion detection systems are constantly updated in their implementation to accommodate new features, performance standards and to utilize new hardware optimization. Reliable, yet practical, testing techniques for validating the configuration enforcement after every new software and firmware update become necessary to assure correct configuration realization. Generating random traffic to test the firewall configuration enforcement is not only inaccurate but also impractical as it requires an infeasible number of test cases for a reasonable testing coverage. In addition, in most cases the policies used during testing are manually generated or have limited configuration profiles. We present a framework for automatic testing of the firewall configuration enforcement using efficient and flexible policy and traffic generation. In a typical test session, a large set of different policies are generated based on the access-control list (ACL) grammar and according to custom profiles. Test packets are generated to particularly consider critical segments of the tested policies and to achieve high coverage of the testing space. We also describe our implementation of a fully-automated framework, which includes ACL grammar modeling, the policy generation, test cases generation, capturing and analyzing firewall output, and creating detailed test reports. Our evaluation results show that our security configuration testing is not only achievable but it also offers high coverage with significant degree of confidence.  相似文献   
72.
Intelligent Service Robotics - This paper presents an online path planning approach for an autonomous tracked vehicle in a cluttered environment based on teaching–learning-based optimization...  相似文献   
73.
74.
Electron backscattered diffraction (EBSD) was used to document the microstructure and texture developed due to cross deformation of commercial purity 1050 aluminum alloy. The materials are first deformed in equal channel angular pressing die (ECAP) to different number of passes; 1,4, 8, 12, and 16 passes, via route BC and then deformed in plane strain compression (PSC) to two axial true plastic strain values of 0.5 and 1.0. Deformation path change was proven to be a very effective tool for manipulating the evolution of microstructure and microtexture. The study provides a documentation of the evolution of microstructure parameters namely cell size, misorientation angle, fraction of submicron grain size, and fraction of high angle grain boundaries. These microstructure parameters were investigated on two planes; the plane normal to the loading direction in PSC (RD–TD) and that plane normal to the transverse direction (RD–ND). These microstructure parameters are compared to those achieved due to the ECAP process only. The ideal rolling texture orientations are depicted and crystal orientation maps were generated. The spatial distribution of grains having these orientations is revealed through these maps. The fraction of the main texture components for a 10° spread around the specified orientations is experimentally calculated and a quantitative idea on the evolution of microtexture is also presented.  相似文献   
75.
A series of novel 4‐arylazo‐3‐methylthiophenes was synthesized by the heterocyclization of 2‐arylhydrazono‐2‐acetyl thioacetanilide derivatives with a variety of α‐halogenated reagents, such as chloroacetone, phenacyl bromide, ethyl chloroacetate, and chloroacetonitrile. The structures of the synthesized thiophene derivatives were confirmed by ultraviolet–visible, IR, and 1H‐NMR spectroscopic techniques and elemental analysis. The synthesized dyes were applied to polyester fabrics as disperse dyes, and their fastness properties were evaluated. The dyed polyester fabrics displayed antibacterial efficacy against Gram‐positive (Staphylococcus aureus) and Gram‐negative (Escherichia coli) bacteria. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011  相似文献   
76.
Pure magnesium powders were ball milled under a hydrogen pressure of 50 bar at room temperature, using reactive ball milling (RBM) approach. The results have shown that a single stable phase of β-MgH2 is obtained upon RBM for 25 h. Increasing the RBM time leads to a significant decreasing on the grain size and an increase in the iron contamination that were introduced to the powders upon using hard steel milling tools. Remarkable changes in the transformed mass fractions of β-MgH2 phase to a metastable γ-MgH2 phase with increasing the RBM time could be detected. Cyclic β-γ-β phase transformations were observed several times upon changing the RBM time. After 200 h of RBM time, the decomposition temperature and activation energy were recorded to be 399 °C and 131 kJ/mol, respectively. Moreover, the times required for complete absorption and desorption of 7 wt.% of hydrogen at 250 °C were recorded to be 3140 s and 35,207 s under 10 and 0 bar, respectively. At 300 °C, the powders that were obtained upon RBM time for 200 h possess excellent hydrogenation properties for any pure MgH2 system, indexed by high hydrogen storage capacity (7.54 wt.%) with complete 600 absorption/desorption cycles. Improvements of hydrogenation/dehydrogenation kinetics are attributed to the presence of γ-phase, the existence of Fe contamination and the nanocrystallinity of the ball milled powders.  相似文献   
77.
The enzyme butyrylcholinesterase (BChE) is known to be involved in the detoxification of xenobiotics in blood plasma and is associated with the progress of neurodegenerative disorders, diabetes type 2, obesity, and diseases of the cardiovascular system. In the present study, we developed carbamate‐based inhibitors serving as positron emission tomography (PET) radiotracers with 18F and 11C as radioisotopes to visualize BChE distribution. These inhibitors are radiolabeled at the carbamate site and transfer this moiety onto BChE, which thus results in covalent and permanent radiolabeling of the enzyme. There are no comparable radiotracers for cholinesterases described to date. By ex vivo autoradiography experiments on mice brain slices and kinetic investigations, selective and covalent transfer of the radiolabeled carbamate moiety onto BChE was proven. These tracers might provide high resolution of BChE distribution in vivo to enable investigations into the pathophysiological mechanisms of diseases associated with alterations in BChE occurrence.  相似文献   
78.

This paper presents a hybrid krill herd (CSKH) approach to solve structural optimization problems. CSKH improved the Krill herd algorithm (KH) by combining KU/KA operator originated from cuckoo search algorithm (CS) with KH. In CSKH, a greedy selection scheme is used and often overtakes the original KH and CS. In addition, in order to further enhance the assessment of CSKH, a fraction of the worst krill is thrown away and substituted with newly randomly generated ones by KA operator at the end of each generation. The CSKH is applied to five real engineering problems to verify its performance. The experimental results have proven that CSKH algorithm is well capable of solving constrained engineering design problems more efficiently and effectively than the basic CS and KH algorithm.

  相似文献   
79.
Listeria monocytogenes is the causal agent of listeriosis, a disease that can be serious and is often fatal in susceptible individuals. The objective of the study was to determine the prevalence of Listeria spp. in raw chicken and ready-to-eat (RTE) chicken products in Amman, Jordan and the antimicrobial resistance of L. monocytogenes isolates. A total of 280 raw chicken and RTE chicken products (chicken-shawirma, chicken-burger, chicken-sausage and mortadella) were collected from Amman abattoir and local retail markets in Amman city. Listeria spp. were isolated by the conventional International Organization for Standardization (ISO) method and L. monocytogenes identified by biochemical and Polymerase Chain Reaction (PCR). Results of conventional method showed that out of total 280 samples, 141 (50%) were found to be contaminated with Listeria spp. [L. monocytogenes (18.2%), Listeria ivanovi (26.1%), Listeria grayi (3.5%), Listeria seeligeri (1.8), Listeria welshimeri (0.7%)]. The PCR confirmed all L. monocytogenes isolates (51 isolates: 15 from raw dressed broiler chicken, 23 from chicken-burger, 9 from chicken-sausage, and 4 from chicken-shawirma). Five of the tested L. monocytogenes isolates were resistance to two antibiotics (tilimicosin and tetracycline) among the ten tested antibiotics as determined by microbroth dilution method. The results presented in this study indicate the potential risk of contamination of RTE chicken products with L. monocytogenes.  相似文献   
80.
Four important commercial aluminum alloys, namely 1050, 5083, 6082 and 7010AA are processed through a single pass via two equal channel angular pressing (ECAP) dies with different geometries (die angles of 90° and 120°). Electron back scattered diffraction (EBSD) is applied on the flow plane of the processed samples. Large scans with a step size of 7 μm for grain size distribution and texture measurements, as well as small scans with a step size of 0.1 μm for determination of cell size distribution, were performed. Hardness and simple compression are employed to evaluate the mechanical properties of the ECAP processed samples. Shear bands in the ECAP processed 7010AA was a major feature that led to failure in all samples subjected to further simple compression. The hardness as well as the stress–strain behavior was similar in the ECAP processed 6082 and 5083AA. The die geometry and the strain involved in the single pass influenced the overall texture intensity developed in the wrought alloys (1050 and 5083AA) and had minimal influence on the texture intensity of the heat treatable alloys (6082 and 7010AA). Low angle grain boundaries dominated the microstructure of all alloys for all testing conditions.  相似文献   
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