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101.
In recent years, many network applications are developed based on group communications (GC), in which the security has to be provided in terms of confidentiality, authenticity and integrity of messages delivered between the group members. A Hierarchical tree structure has to be constructed in such a way that it can handle large dynamic groups with the effective key formation and key distribution. In this paper, an Optimal Cluster Hierarchical Tree (OCHT) structure is presented for effective group communication. The proposed OCHT structure provides a novel solution for multicast key management with decentralized architecture to ensure scalability, reliability and cost effectiveness. Simulation results reveal that proposed OCHT based decentralized architectures provide better performance when compared with existing Logical Hierarchical Tree (LKH). The parameters used for simulation are Memory Overhead, Throughput, Packet Delivery Ratio, End-to-End Latency and Energy consumption. 相似文献
102.
Said Gaoua Shahrooz Asadi Mustapha C. E. Yagoub Farah A. Mohammadi 《Analog Integrated Circuits and Signal Processing》2010,63(1):59-70
In today’s radiofrequency and microwave communication circuits, there is an ever-increasing demand for higher integration
and miniaturization. This trend leads to massive computational tasks during simulation, optimization and statistical analyses,
requiring robust modeling tools so that the whole process can be achieved reliably. In this paper, the authors proposed frequency-
and time-domain computer-aided design tools that can characterize RF/microwave field effect and heterojunction bipolar transistors
and efficiently predict a circuit performance. The proposed tools are demonstrated through examples. 相似文献
103.
Varied research findings have been taken to support the claim that humans' representation of the self is "special," that is, that it emerges from systems that are physically and functionally distinct from those used for more general purpose cognitive processing. The authors evaluate this claim by reviewing the relevant literatures and addressing the criteria for considering a system special, the various operationalizations of self, and how the studies' findings relate to the conclusions drawn. The authors conclude that many of the claims for the special status of self-related processing are premature given the evidence and that the various self-related research programs do not seem to be illuminating a unitary, common system, despite individuals' subjective experience of a unified self. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
104.
Safa A. Al-Naimi Farah Talib Jasim Al-Sudani Essam K. Halabia 《Chemical Engineering Research and Design》2011,89(7):930-939
The hydrodynamics in a trickle bed reactor (TBR) in non-ambient conditions are studied for air-water and air-acetone (pure organic liquid of low surface tension) systems. A flow map experiments for air-water and air-acetone systems are performed in a pilot plant reactor of 0.05 m i.d. and 1.25 m height. It has been demonstrated from the experimental results that the pressure drop tends to increase with increasing superficial gas and liquid velocity and reactor pressure, while it tends to decrease with increasing bed temperature. The results also show that the dynamic liquid holdup increases with increasing liquid velocity and decreases with increasing superficial gas velocity, reactor pressure and bed temperature. The dynamic liquid holdup and pressure drop values are obviously higher than those measured for air-water system at the same fluid fluxes, reactor pressure and bed temperature due to the surface tension effects. For higher reactor pressure and temperature, the trickle to pulse transition boundary shifts towered higher superficial velocities of both gas and liquid. 相似文献
105.
Neuropsychological disorders have traditionally been understood in terms of a focal lesion to a single component of a cognitive architecture. Optic aphasia (OA) defies explanation in this way. In OA, naming of visual stimuli is impaired in the absence of general visual agnosia or anomia. OA has been explained by positing multiple semantic systems or multiple functional pathways to visual naming. M. J. Farah (1990) instead sketched a parsimonious account based on multiple lesions—to pathways mapping visual input to semantics and semantics to naming responses—and the assumption that the effects of the lesions are superadditive. The authors demonstrate superadditive effects of damage in a connectionist architecture and model other phenomena associated with OA. Multiple lesions with superadditivity provide a novel class of explanations for neuropsychological deficits that previously seemed to imply the existence of highly specialized processing components. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
106.
Farah Belmecheri Christian Prins Farouk Yalaoui Lionel Amodeo 《Journal of Intelligent Manufacturing》2013,24(4):775-789
Today, companies need to collect and to deliver goods from and to their depots and their customers. This problem is described as a Vehicle Routing Problem with Mixed Linehaul and Backhaul customers (VRPMB). The goods delivered from the depot to the customers can be alternated with the goods picked up. Other variants of VRP added to VRPMB are Heterogeneous fleet and Time Windows. This paper studies a complex VRP called HVRPMBTW which concerns a logistic/transport society, a problem rarely studied in literature. In this paper, we propose a Particle Swarm Optimization (PSO) with a local search. This approach has shown its effectiveness on several combinatorial problems. The adaptation of this approach to the problem studied is explained and tested on the benchmarks. The results are compared with our previous methods and they show that in several cases PSO improves the results. 相似文献
107.
Cisplatin (CP) is an effective chemotherapeutic agent widely used in the treatment of many malignant tumours. However, its therapeutic utility is limited by dose dependent nephrotoxicity. Several agents/strategies have attempted to prevent CP nephrotoxicity but were not found suitable for clinical practice. Dietary flaxseed oil (FXO), a rich source of omega-3 fatty acids has been shown to prevent/reduce the progression of certain types of cardiovascular and renal disorders. The protective effect of FXO on CP induced nephrotoxic and other deleterious effects was investigated. Rats were prefed experimental diets for 10 days and then received a single dose of CP (6 mg/kg body weight) intraperitoneally while still on diet. Serum/urine parameters, enzymes of brush border membrane (BBM), oxidative stress and carbohydrate metabolism in rat kidney were analyzed. CP nephrotoxicity was recorded by increased serum creatinine and blood urea nitrogen. CP decreased the activities of metabolic enzymes, antioxidant defense system and BBM enzymes. In contrast, FXO alone increased enzyme activities of carbohydrate metabolism and brush border membrane. FXO feeding to CP treated rats markedly enhanced resistance to CP-elicited deleterious effects. Dietary FXO supplementation ameliorated CP induced specific metabolic alterations and oxidative damage due to its intrinsic biochemical antioxidant properties. 相似文献
108.
Communicating Finite State Machines (CFSM) lack the high level syntactic and structural abstractions of Communicating Complex
State Machines (CCSM), such as nesting and encapsulation, to model highly complex protocols that are likely to arise in web
services environments. The incorporation of these features in a protocol specification model would require the design of a
new validation technique to efficiently check for protocol errors, such as deadlocks and non-reachable transitions. A reachability
graph is used to represent the execution states of the protocol and to verify their consistency. In this paper, we propose
a new validation technique for protocols modeled with complex FSM, called RLRA (Reverse Leaping Reachability Analysis), which
enables the detection of all deadlock errors. It is a backtracking approach, which first identifies an initial set of suspected
states, those possibly containing deadlocks, then refines this set to those likely to cause deadlock, and finally backtracks
through the graph while checking for errors until the root state of the protocol is reached. Leap graphs are employed to prune
the number of execution states examined, and thereby mitigate the combinatorial explosion of the state space. Extensive tests
and comparisons were performed, which show the effectiveness of our technique. 相似文献
109.
The Fatty Acid Profile and Phenolic Composition of Descurainia sophia Seeds Extracted by Supercritical CO2 下载免费PDF全文
Mehri HadiNezhad Owen Rowland Farah Hosseinian 《Journal of the American Oil Chemists' Society》2015,92(9):1379-1390
Oil and phenolics were extracted from Descurainia sophia (Sophia) seeds by a supercritical CO2 system. Extractions were conducted in two sequential steps, first using 100 % CO2 and then adding 10 % ethanol as co‐solvent. The extracts were collected in each step using two separate collectors operating at different pressures. The extraction run was 3 and 4 h for the first period, and 2 h for the second period. The majority of the oil was collected in the first extraction period while phenolic compounds were obtained in the second extraction period. A combined mode of static/dynamic extraction (3 h running and 1 h soaking in CO2) was also used in the first extraction period, which enhanced the total extraction yield (29.3 ± 0.5 %) and was comparable to the 4 h extraction yield (31.4 ± 0.1 %). The total fatty acid (FA) content of oil in collector 1 (0.94 g) was nearly twice that in collector 2 (0.60 g). The oil contained 14 FAs with α‐linolenic being predominant (48.5 %), with a total 91.1 % unsaturated FAs, a ω3/ω6 ratio of 2.7, and an erucic acid content of 6.2 %. More than 10 phenolic compounds were detected by HPLC in the Sophia seed extracts of which sinapic acid was the dominant compound. Sophia seed extracts showed high levels of antioxidant activity. These results suggest that Sophia seed oil and phenolics have the potential for functional food and pharmaceutical applications. 相似文献
110.
Iminosugar‐Based Galactoside Mimics as Inhibitors of Galactocerebrosidase: SAR Studies and Comparison with Other Lysosomal Galactosidases 下载免费PDF全文
Dr. Anna Biela‐Banaś Dr. Farah Oulaïdi Sophie Front Dr. Estelle Gallienne Dr. Kyoko Ikeda‐Obatake Dr. Naoki Asano Dr. David A. Wenger Prof. Olivier R. Martin 《ChemMedChem》2014,9(12):2647-2652
Several families of iminosugar‐based galactoside mimics were designed, synthesized, and evaluated as galactocerebrosidase (GALC) inhibitors. They were also tested as inhibitors of lysosomal β‐ and α‐galactosidases in order to find new potent and selective pharmacological chaperones for treatment of the lysosomal storage disorder, Krabbe disease. Whereas 1‐C‐alkyl imino‐L ‐arabinitols are totally inactive toward the three enzymes, 1‐C‐alkyl imino‐D ‐galactitols were found to be active only toward α‐galactosidase A. Finally, 1‐N‐iminosugars provided the best results, as 4‐epi‐isofagomine was found to be a good inhibitor of both lysosomal β‐galactosidase and GALC. Further elaboration of this structure is required to achieve selectivity between these two galactosidases. 相似文献