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251.
Cognitive and self-selective routing for sensor networks 总被引:1,自引:0,他引:1
Erol Gelenbe Peixiang Liu Boleslaw K. Szymanski Christopher Morrell 《Computational Management Science》2011,8(3):237-258
New approaches to Quality-of-Service (QoS) routing in wireless sensor networks which use different forms of learning are the
subject of this paper. The Cognitive Packet Network (CPN) algorithm uses smart packets for path discovery, together with reinforcement
learning and neural networks, while Self-Selective Routing (SSR) is based on the “Ant Colony” paradigm which emulates the
pheromone-based technique which ants use to mark paths and communicate information about paths between different insects of
the same colony (Koenig et al. in Ann Math Artif Intell 31(1–4): 41–76, 2001). In this paper, we present first experimental
results on a network test-bed to evaluate CPN’s ability to discover paths having the shortest delay, or shortest length. Then,
we present small test-bed experiments and large-scale network simulations to evaluate the effectiveness of the SSR algorithm.
Finally, the two approaches are compared with respect to their ability to adapt as network conditions change over time. 相似文献
252.
Gelatin-Immobilised Poly(hydroxyethyl methacrylate) Cryogel for Affinity Purification of Fibronectin
In this work, fibronectin purification from human plasma with the gelatin-immobilised poly(hydroxyethyl methacrylate) (PHEMA) cryogel has been evaluated. The PHEMA cryogel was prepared by cryo-polymerisation which proceeds in an aqueous solution of monomer frozen inside a plastic syringe. The PHEMA cryogel contained interconnected macrochannels of 10–200 μm in diameter. Gelatin molecules were covalently immobilised onto the PHEMA cryogel via carbodiimide activation. The gelatin-immobilised PHEMA cryogel was used to purify fibronectin from human plasma. Fibronectin adsorption from human plasma on the PHEMA cryogel was 0.30 mg/ml, while much higher adsorption values, up to 38 mg/ml, was obtained with the gelatin-immobilised PHEMA cryogel. The fibronectin adsorption capacity of the gelatin-immobilised PHEMA cryogel did not change with an increase in the flow rate of plasma. Up to 92 % of the adsorbed fibronectin was eluted using 2 M urea containing 1 M NaCl as elution agent. The adsorption–elution cycle was repeated ten times using the same PHEMA cryogel. No remarkable decrease was detected in the adsorption capacity of the gelatin-immobilised PHEMA cryogel. 相似文献
253.
Jean-Marc Noël Jeyavel Velmurugan Ebru Gökmeşe Michael V. Mirkin 《Journal of Solid State Electrochemistry》2013,17(2):385-389
The previously developed methodologies for fabricating flat, polished nanoelectrodes were extended to produce silver electrodes with the radii from 50 nm to micrometers. The prepared electrodes were characterized by steady-state voltammetry, scanning electrochemical microscopy (SECM), and atomic force microscopy. The protocol was developed for controlled chemical etching of silver in ammonia solutions to produce recessed nanoelectrodes. Voltammograms and SECM approach curves were obtained to evaluate the recess depth and other geometric parameters of the etched electrodes. 相似文献
254.
While transfusion safety, particularly with respect to transfusion-transmitted infectious diseases, has improved dramatically over the past several decades, progress in other clinical processes of blood product transfusion continue with highly variable practices and human errors that contribute to adverse outcomes. In this paper, we study the adverse outcome risk in red blood cell (RBC) transfusion in the United States using Probabilistic Risk Assessment (PRA). PRA allows us to map, in a comprehensive manner, the various types of events that may contribute to an adverse outcome, including socio-technical factors such as the risk coming from human error; and allows us to formalize the logical relationships among those events and the adverse outcome risk. We utilize the PRA model to assess the risk to the patient from RBC transfusion in the United States, to identify the major risk points in the transfusion process, and to evaluate the costs and benefits of several risk reduction strategies. Our data come from published studies in the medical literature. We find that the risk of a potentially severe outcome (e.g., mortality, major injury or other serious long-term consequences, a life threatening incident) from RBC transfusion lies in the interval [10.4327,511.2] per 100,000 units of RBC transfused, with a point estimate of 25.4527. The leading causes of severe outcomes include circulatory overload and bacterial infection. Acute hemolytic reactions, which are mainly caused by erroneous administration of the blood, also contribute significantly to severe outcomes of transfusion. Interestingly, our analysis indicates that an intervention that is targeted at reducing the risk of the erroneous administration of blood (through training programs or technology investments) has a higher potential impact in reducing the severe outcome risk from RBC transfusion than additional screening to further reduce the risk of transfusion-transmitted viral infections, of HIV 1-2, hepatitis B, and hepatitis C, which the lay public fears most. Furthermore, such an error reduction program will be more cost-effective than the additional screening of donated blood. Our study provides guidelines for public policy to improve the safety of RBC transfusion in the United States. 相似文献
255.
256.
Ibrahim Erol 《高分子科学》2008,(4):443-454
The synthesis of two new methacrylates such as 2-[(cyclohexylideneamino)oxy]-2-oxoethyl methylacrylate (CHOEMA)and 2-[(cyclopentylideneamino)oxy]-2-oxoethyl methylacrylate(CPOEMA)are described.The monomers produced from the reaction of corresponding cyclohexanone O-(2-chloroacetyl)oxime and cyclopentanone O-(2- chloroacetyl)oxime with sodium methacrylate was polymerized in 1,4-dioxane solution at 65℃using AIBN as an initiator. The monomers and their polymers were characterized by IR,~1H- and ~(13)C-NMR s... 相似文献
257.
Ebru Cubuk Demiralay Guleren Alsancak Sibel A. Ozkan 《Journal of separation science》2009,32(17):2928-2936
In this study, pKa values were determined by using the dependence of the capacity factor on the pH of the mobile phase for four ionizable substances, namely, tenoxicam, piroxicam, meloxicam, and naproxen (I.S.). The effect of the mobile phase composition on the ionization constant was studied by measuring the pKa at different ACN concentrations, ranging from 30 to 40%. The adequate condition for the chromatographic determination of these compounds in pharmaceutical dosage forms was established based on the different retention behaviors of the species. An octadecylsilica Nucleosil C18 column (150×4.6 mm, 5 μm) was used for all the determinations. The chromatographic separation of oxicams was carried out using acetonitrile (ACN)/water at 35% v/v, containing 65 mM phosphoric acid and UV detection at a wavelength of 355 nm. The method developed was successfully applied to the simultaneous determination of these drug compounds in laboratory‐prepared mixtures and their commercial pharmaceutical dosage forms. Each analysis requires no longer than 12 min. 相似文献
258.
We present the dynamical phase diagrams of the kinetic Blume–Capel model with random diluted single-ion anisotropy in a square lattice under the presence of a time-varying (oscillating) external magnetic field calculated by an analytical method, the effective-field theory (EFT). The kinetics is modeled with the formalism of a master equation. The time-averaged magnetization (M) acts as the order parameter and divides the temperature–field plane into three regions: ferromagnetic, paramagnetic, and coexistence of ferromagnetic and paramagnetic phases. In addition, the hysteresis loop area and the dynamic correlation function are calculated. It is observed that the inclusion of spin–spin correlations suppress the first-order transition lines and dynamical tricritical points for all values of the crystal-field concentration. 相似文献
259.
Dynamic behavior of a site diluted Ising ferromagnet in the presence of a periodically oscillating magnetic field has been analyzed by means of the effective field theory (EFT). The dynamic equation of motion has been solved for a honeycomb lattice (z=3) with the help of a Glauber type stochastic process. The global phase diagrams and the variation of the corresponding dynamic order parameter as a function of the Hamiltonian parameters and temperature has been investigated in detail and it has been shown that the system exhibits reentrant phenomena, as well as a dynamic tricritical point which disappears for sufficiently weak dilution. 相似文献
260.
In this study, we have analyzed the dynamical phase transitions of spin-1 Blume-Capel model with quenched random crystal field
under the effect of a time dependent oscillating magnetic field. We have obtained the magnetic field, temperature (h,T) cross sections of the global phase diagram for constant values of the concentration and the amplitude of the single-ion
anisotropy within mean field approximation. There are regions of the phase space where both ordered and disordered phases
coexist. In addition, the dynamic phase transition from one regime to the other can be a first- or a second-order depending
on the region in the phase diagram. Hence, the system exhibits a number of interesting phenomena and a rich variety of phase
diagrams with type being according to the concentration p of active local crystal fields. 相似文献