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31.
In earlier work, we presented a value based measure of cybersecurity that quantifies the security of a system in concrete terms, specifically, in terms of how much each system stakeholder stands to lose (in dollars per hour of operation) as a result of security threats and system vulnerabilities; our metric varies according to the stakes that each stakeholder has in meeting each security requirement. In this paper, we discuss the specification and design of a system that collects, updates, and maintains all the information that pertains to estimating our cybersecurity measure, and offers stakeholders quantitative means to make security-related decisions.  相似文献   
32.
Cu/Y1Ba2Cu3O7?x superconducting composite wires have been fabricated using the powder-in-tube coextrusion process. Increase in load during the extrusion process seems to indicate that powder particles from the deformation zone of the die travel up toward the unextruded part of the billet and gradually increase the density in that part to some saturation value, which prohibits further extrusion at moderate to heavy applied load. A powder removal technique has been devised to perform full length extrusion under such conditions. Powder removal, however, is not required if the extrusion ratio is reduced sufficiently. The extrusion ratio that will give a full length extrusion without powder removal seems to be a function of starting billet length. Extrusion ratio of 2.52 gives smooth full length extrusions with 25.4 mm (1 in.) starting billet length at reasonable load values. Four probe resistivity and magnetic susceptibility measurements indicate a critical temperature (Tc) value of the formed wire to be close to 88 K. Density measurements using the volume displacement method indicate a value of 4.819 g/cm3, which is approximately 76.5% of the theoretical density. M.M. Dehghani and A. Ahmad are Assistant Professor and  相似文献   
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34.
The particle distribution of a dilute solid-liquid suspension through a stenosed arterial geometry was investigated. Particle image velocimetry (PIV) was used to determine the velocity as well as to acquire the flow images. The light intensity scattered by particles was evaluated to determine the particle distribution. Flow separation exists where the flow emerges from the stenosis throat. From the PIV images, the particle density distribution exhibited differing non-uniform characteristics which vary with flow rate, particle size and particle concentration. At low flow rates, a particle-free layer is formed. As the flow rate is increased, particles accumulate in concentric recirculation orbits within the downstream vortex. Particles with larger size and higher concentration tend to accumulate more towards the center of the vortex.  相似文献   
35.
Multimedia Tools and Applications - Automatic Speaker Verification (ASV) systems are vulnerable to spoofing attacks. Most existing spoofing detection systems rely on two main points; the feature...  相似文献   
36.
The purpose of this study was to investigate the impact of adding nano-stabilisers on some properties of yoghurt. Carboxymethyl cellulose (CMC), sodium alginate (SA) and kappa-carrageenan (K-C) were used at 0.2%, 0.2% and 0.02% in their original forms and 0.15%, 0.15% and 0.015% in nano-form, respectively. The effects of these additives on yoghurt pH, titratable acidity, viscosity, syneresis, texture, colour, starter culture bacterial count, mould and yeast count, coagulation time and microstructure were studied. The use of nano-stabilisers increased viscosity, hardness and coagulation time; reduced syneresis and Streptococcus thermophilus count; and improved colour. Results indicated that nano-stabilisers improved the rheological and technological characteristics of yoghurt.  相似文献   
37.
Coal fly ash(CFA)is composed of minerals containing some oxides in crystalline phase(i.e.,quartz and mullite),as well as unburned carbon as mesoporous material,thus enabling CFA to act as a dual-sites adsorbent with unique properties.This work focused on the adsorption of Pb(Ⅱ)and Zn(Ⅱ)from binary system,a mixture containing two metal ion solutions present simultaneously,onto NaOH-modified CFA(MCFA).Several adsorption tests were conducted to evaluate the effect of several parameters,includ-ing pH and contact times.The experiment results indicated that chemical treatment of CFA with NaOH increased pore volume from 0.021 to 0.223 cm3 g-1.In addition,it could also enhance the availability of functional groups on both minerals and unburned carbon,resulting in almost 100%Pb(Ⅱ)and 97%Zn(Ⅱ)adsorbed.The optimum pH for adsorption system was pH=3 and quasi-equilibrium occurred in 240 minutes.Equilibrium data from the experimental results were analyzed using Modified Extended Langmuir(MEL)and Competitive Adsorption Langmuir-Langmuir(CALL)isotherm models.The analysis results showed that the CALL isotherm model could better describe the Pb(Ⅱ)and Zn(Ⅱ)adsorption pro-cess onto MCFA in binary system compared with MEL isotherm model.  相似文献   
38.
Intermittent drying may be of interest in the future to address energy issues. Such drying conditions are also likely to help stress relaxation through mechanosorptive creep. The influence of applying oscillations of temperature and relative humidity during the drying of beech timber on time and drying stresses is discussed in the paper by means of nonsymmetrical and loaded drying. Experimental data were used to validate a numerical model in the case of intermittent drying. The model was then used to perform a numerical investigation of the possibility of using an intermittent energy source to dry wood.  相似文献   
39.
Multimedia Tools and Applications - Performances of speech enhancement algorithms depend greatly on the accuracy of the estimated noise. In this paper, we explain in details the relationship...  相似文献   
40.
Thin films of a-Se80Te20−xCux (where x=2, 6, 8 and 10) were deposited on glass substrates by vacuum evaporation technique. The absorbance, reflectance and transmittance of as-deposited thin films were measured in the wavelength region 400-1000 nm. The optical band gap and optical constants of amorphous thin films have been studied as a function of photon energy. The optical band gap increases on incorporation of copper in Se80Te20−xCux system. The value of refractive index (n) decreases while the value of the extinction coefficient (k) increases with increasing photon energy. The results are interpreted in terms of concentration of localized states.  相似文献   
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