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排序方式: 共有55条查询结果,搜索用时 15 毫秒
1.
Weizheng Gao Kashi Neupane Rainer Steinwandt 《International Journal of Information Security》2014,13(5):467-476
In 2007, Bohli et al. (Int J Inf Secur 6:243–254, 2007) proposed a two-round group key agreement protocol in the random oracle model, which in addition to semantic security offers strong entity authentication and a security guarantee against malicious insiders. We suggest a modification of this protocol that preserves the security guarantees and the round complexity, but reduces the amount of data that has to be sent and also reduces the number of signature computations and verifications by 50 %. Moreover, we propose a variant of Bohli et al.’s protocol whose security analysis does not require a random oracle or other idealizing assumptions. 相似文献
2.
The antioxidant vitamin E, -tocopherol, was tested as a candidate elicitor of alterable antiherbivory in soybean plants against cabbage looper larvae. Although a nonspecific antioxidant, vitamin E proved elicitory to the involved sulfhydryl-dependent receptor-energy transducer protein in soybean plasma membrane. Effects of -tocopherol were dependent on dosage, time, and space in the plant. The observed elicited effects were all decreases in herbivory. The best negative phytochemical correlate of looper feeding was the percentage of increased total HPLC peak area of extractables from elicited as compared to nonelicited leaves. Some specific compounds, e.g., glyceollins, were quantitatively major components of the total profile of secondary metabolites. 相似文献
3.
In recent years, there has been a growing interest in wireless sensor networks. One of the major issues in wireless sensor network is developing an energy-efficient clustering protocol. Hierarchical clustering algorithms are very important in increasing the network’s life time. Each clustering algorithm is composed of two phases, the setup phase and steady state phase. The hot point in these algorithms is the cluster head selection. In this paper, we study the impact of heterogeneity of nodes in terms of their energy in wireless sensor networks that are hierarchically clustered. We assume that a percentage of the population of sensor nodes is equipped with the additional energy resources. We also assume that the sensor nodes are randomly distributed and are not mobile, the coordinates of the sink and the dimensions of the sensor field are known. Homogeneous clustering protocols assume that all the sensor nodes are equipped with the same amount of energy and as a result, they cannot take the advantage of the presence of node heterogeneity. Adapting this approach, we introduce an energy efficient heterogeneous clustered scheme for wireless sensor networks based on weighted election probabilities of each node to become a cluster head according to the residual energy in each node. Finally, the simulation results demonstrate that our proposed heterogeneous clustering approach is more effective in prolonging the network lifetime compared with LEACH. 相似文献
4.
Wireless sensor networks (WSNs) are a kind of communication networks having independent sensor nodes that form multi-hop ad hoc network to transfer data. In the past few years, various transport control protocols in wireless sensor networks (WSNs) have been developed and proposed in the literature. In this paper, we have analyzed pump slowly, fetch quickly (PSFQ) protocol and presented an improved transport layer protocol for wireless sensor networks. The improved protocol has been analyzed based on various factors such as average latency and average error tolerance and it is found that the proposed protocol is better than PSFQ in terms of these factors. 相似文献
5.
Influence of fine ceramic aggregates on the residual properties of concrete subjected to elevated temperature 下载免费PDF全文
Deepak Rajawat Salman Siddique Sandeep Shrivastava Sandeep Chaudhary Trilok Gupta 《火与材料》2018,42(7):834-842
The residual properties of concrete subjected to elevated temperature are of importance to assess the stability of the structure. This paper investigates the performance of concrete containing white ware ceramic sand exposed to elevated temperature. Concrete mixes containing 0%, 50%, and 100% ceramic sand were prepared. The specimen were exposed to elevated temperatures of 200°C, 500°C, and 800°C for a duration of 60 minutes. Their residual mechanical properties (compressive strength, split tensile strength), ultra sonic pulse velocity, and mass change for different cooling regimes were investigated and compared among specimen. The results showed that incorporation of ceramic sand in concrete mixes improved the resistance against elevated temperature of hardened concrete. 相似文献
6.
Sagar Raj Satyal Ben Leshchinsky Jie Han Madan Neupane 《Geotextiles and Geomembranes》2018,46(2):190-205
Due to extensive right-of-way, railroads are inevitably subject to poor subgrade conditions and interrupted service for significant maintenance due to excessive deformations and loss of track geometry. Geocell confinement presents itself as a possible solution for improving performance of ballasted railroad embankments over weak subgrade. To investigate the efficacy of geocell confinement on ballasted railway embankments, a set of well-instrumented, large-scale cyclic plate loading tests and numerical simulations were performed on geocell-confined ballast overlaying a weak subgrade material. The agreement of results from tests and simulations served as a basis for simulating practical track geometry and performance for various geocell configurations and subgrades using three-dimensional (3D) finite element (FE) analyses. The study showed that geocell reinforcement significantly decreased track settlement, decreased subgrade deformations with lower and uniform distribution of vertical stresses on subgrade and inhibited lateral deformation and serviceability under cyclic loading. These results demonstrate that geocell confinement can be an effective alternative to subsurface improvement or shorter maintenance cycles, particularly on weak subgrades. 相似文献
7.
S. Neupane G. Kaganas R. Valenzuela L. Kumari X. W. Wang W. Z. Li 《Journal of Materials Science》2011,46(14):4803-4811
We report the synthesis of ruthenium dioxide (RuO2) nanostructures by thermal evaporation of RuO2 powder. RuO2 nanostructures of different shapes were synthesized at various concentration, flow rate, and pressure of oxygen. At a constant
pressure of 3 torr of flowing oxygen, polygonal prism-like RuO2 nanorods with flat tips were grown at an O2 flow rate of 100 sccm; club-shaped nanorods with obelisk tip were formed at 300 and 600 sccm, and hollow rods with square
tip were formed at 1800 sccm. A mixture of O2 and Ar at a total flow rate of 600 sccm led to the formation of short club-shaped nanorods indicating the suppression effect
of Ar on the growth of nanorods. The pressure also had a significant effect on the formation of RuO2 nanostructures, at a fixed flow rate of 600 sccm of O2, a pressure of 3 torr resulted in the growth of club-shaped RuO2 nanorods, while high pressures of 380 and 760 torr resulted in the formation of both linear club-shaped and pine tree-like
hierarchical RuO2 nanorods. X-ray diffraction and transmission electron microscopy analysis indicated the formation of tetragonal phase of
RuO2 with high crystallinity. A density functional calculation on RuO2, RuO3, and RuO4 was performed to help to explain the experimental results. 相似文献
8.
Madhav Prasad Neupane Yu Kyoung Kim Il Song Park Sook Jeong Lee Min Ho Lee Tae Sung Bae 《Metals and Materials International》2008,14(5):607-613
This study examines the surface morphology, microstructure, and chemical composition of titanium surfaces treated by anodic
spark oxidation in phosphate buffer solution at pH 2, 7 and 12. The pH of the electrolyte was found to play a substantial
role in the formation of different morphologies, chemical compositions, and pore dimensions with microporous structures. SEM
revealed variation in the topologies of the anodized surface with electrolyte pH. Porous structures with uniform pores and
high roughness were obtained in pH 12 solutions. However, intense anatase crystal was obtained at pH 7. The relationship between
surface characteristics of titanium and initial interactions of titanium-osteoblasts was also in vestigated. Our findings
demonstrated the cell viability and proliferation on the anodic oxides produced at pH 12 to be superior to those produced
at pH 2 and 7 as well as on the control titanium surface. This study also provides evidence of enhanced osteoblast adhesion
on anodized metal substrates under in vitro conditions. 相似文献
9.
Mirza Mohyuddin Trilok R. Sharma Ernst G. Niemann 《Journal of the science of food and agriculture》1978,29(2):121-126
Aspergillus flavus Link ex Fr., was used to evaluate the Relative Nutritive Value (RNV) in a set of triticale cultivars having shrivelled grain characteristics. The protein content in these samples ranged from 11.8 to 24.0%. The milled material was tested at 3 mg nitrogen level. Biomass of the fungus was measured as the total dry weight of the mycelium produced after 72 h of shaking and taken as the index of Relative Nutritive Value. The fungal biomass was negatively correlated with protein content and dye binding capacity while a positive correlation existed with protein index. With the use of glucose as an extra energy source, the basic pattern of response remained the same but the magnitude of correlation decreased. 相似文献
10.
Khan Muzaffar Iqbal Upadhyay Trilok Chandra 《Journal of Low Temperature Physics》2021,203(5-6):401-418
Journal of Low Temperature Physics - Modified two-sublattice pseudospin lattice coupled-mode (PLCM) model Hamiltonian by adding third- and fourth-order anharmonic interactions, extra... 相似文献