A new one-way hash function based on the unified chaotic system is constructed. With different values of a key parameter, the unified chaotic system represents different chaotic systems, based on which the one-way has...
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A new one-way hash function based on the unified chaotic system is constructed. With different values of a key parameter, the unified chaotic system represents different chaotic systems, based on which the one-way hash function algorithm is constructed with three round operations and an initial vector on an input message. In each round operation, the parameters are processed by three different chaotic systems generated from the unified chaotic system. Feed-forwards are used at the end of each round operation and at the end of each element of the message processing. Meanwhile, in each round operation, parameter-exchanging operations are implemented. Then, the hash value of length 160 bits is obtained from the last six parameters. Simulation and analysis both demonstrate that the algorithm has great flexibility, satisfactory hash performance, weak collision property, and high security.
Streaming XML data is often encountered in applications in Medical Biology. So, how to effectively manage and query XML data streams can be a fundamental issue for the quality of those Medical Biology applications. Wi...
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Streaming XML data is often encountered in applications in Medical Biology. So, how to effectively manage and query XML data streams can be a fundamental issue for the quality of those Medical Biology applications. With respect to current methods for XPath query evaluation over XML data streams, adoption of some query rewriting techniques are common when encountering some complex query which can cause ambiguities and redundant query cost. Lots of work can be found in database research community to simplify query and remove its redundancy. However, less attention is paid to make use of query rewriting to benefit the query evaluation process of an efficient XML data stream query system. In other words, the query rewriting is not directly for the purpose of simplicity or redundancy removal;whereas it is for the convenience of an efficient query. In this paper, we propose a normalization process which rewrites the Forward XPath expressions for our XML data stream query system. The proposed normalization is expected to normalize all the complex predicates connected with logic operators into twig structures. With this normalization, queries can be transformed into a well-structured one, the formal way of the normalization makes the query language of our XML data stream query system more precise and the twig structure facilitates the query evaluation of our query system.
Bioactive glass is well known for its ability of bone regeneration, and sol-gel bioactive glass has many advantages compared with melt-derived bioactive glass. 3-D scaffold prepared by the sol-gel method is a promisin...
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Bioactive glass is well known for its ability of bone regeneration, and sol-gel bioactive glass has many advantages compared with melt-derived bioactive glass. 3-D scaffold prepared by the sol-gel method is a promising substrate material for bone tissue engineering and large-scale bone repair. Porous sol-gel glass in the CaO-SiO2-P205 system with macropores larger than 100 μm was prepared by the addition of stearic acid as a pore former. The diameter of the pore created by the pore former varied from 100 to 300 μm. The formation of a hydroxyapatite layer on the glass was analyzed by studying the surface of the porous glass by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and Raman spectra after they had been immersed in simulated body fluid （SBF） for some time, and the porous glass shows good bioactivity.
Based on the problem that the service entity only has the partial field of vision in the network environment,a trust evolvement method of the macro self-organization for Web service combination was *** the method,the ...
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Based on the problem that the service entity only has the partial field of vision in the network environment,a trust evolvement method of the macro self-organization for Web service combination was *** the method,the control rule of the trust degree in the Dempster-Shafer(D-S)rule was utilized based on the entity network interactive behavior,and a proportion trust control rule was put *** control rule could make the Web service self-adaptively study so as to gradually form a proper trust connection with its cooperative entities and to improve the security performance of the whole *** experimental results show that the historical successful experience is saved during the service combination alliance,and the method can greatly improve the reliability and success rate of Web service combination.
Introduced the phase deducted method into signals analysis of rock bolt's non-destructive testing. At first, Fourier transform and digital filter were employed to a collection signal, and the central frequency of ...
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Introduced the phase deducted method into signals analysis of rock bolt's non-destructive testing. At first, Fourier transform and digital filter were employed to a collection signal, and the central frequency of the signal was regarded as an initial value in the formula of phase deducted method. Used the rule of phase calculation results with time, estimated the reflecting signals at the bottom or defects of rock bolts from phases' aberration. According to the processing results of practical data, there are aberration phenomena at the bottom or defects of rock bolts for the phase curve. Determined positions of reflecting signals, and calculated an rock bolt's length and grouting plumpness. At the same time, the defect position could be determined. The study results indicate that the signals from the bottom or defects of rock bolts can be identified rapidly, and then the construction quality can be judged. The phase deducted method can improve inversion reliability in non-destructive testing of stress wave, and it can be popularized in the rock bolt testing in the future.
We proposed a distributed energy saving clustering algorithm BPEC. Cluster-heads are elected by two probabilities. The primary probability is based on the ratio between average residual energy of neighbor nodes and it...
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A new convenient synthesis of a series of 1,aryl,2,propanones using aromatic amines as precursors,via diazo,reaction and improved Meerwein arylation reaction under mild conditions, was achieved. In addition,1,[3,5,bis...
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A new convenient synthesis of a series of 1,aryl,2,propanones using aromatic amines as precursors,via diazo,reaction and improved Meerwein arylation reaction under mild conditions, was achieved. In addition,1,[3,5,bis(trifluoromethyl)phenyl],2,propanone is a new compound among the synthesized compounds. This approach is an efficient synthetic method for the arylpropanones with different substituting groups.
A novel method was designed to solve reinforcement learning problems with artificial potential *** a reinforcement learning problem was transferred to a path planning problem by using artificial potential field(APF),w...
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A novel method was designed to solve reinforcement learning problems with artificial potential *** a reinforcement learning problem was transferred to a path planning problem by using artificial potential field(APF),which was a very appropriate method to model a reinforcement learning ***,a new APF algorithm was proposed to overcome the local minimum problem in the potential field methods with a virtual water-flow *** performance of this new method was tested by a gridworld problem named as key and door *** experimental results show that within 45 trials,good and deterministic policies are found in almost all *** comparison with WIERING's HQ-learning system which needs 20 000 trials for stable solution,the proposed new method can obtain optimal and stable policy far more quickly than ***,the new method is simple and effective to give an optimal solution to the reinforcement learning problem.
To satisfying expected coverage degree of application, we derived the smallest active node number K through node active-sleep theory. We also achieved intra-cluster active nodes scheduling algorithm. In Data Gathering...
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Immobilization of the atom transfer radical polymerization (ATRP) macroinitiators at the silica nanoparticle surfaces was achieved through surface modification with excess toluene-2,4-diisocynate (TDI), after which th...
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Immobilization of the atom transfer radical polymerization (ATRP) macroinitiators at the silica nanoparticle surfaces was achieved through surface modification with excess toluene-2,4-diisocynate (TDI), after which the residual isocyanate groups were converted into ATRP macroinitiators. Structurally well-defined polystyrene chains were grown from the nanoparticle surfaces to yield individual particles composed of a silica core and a well-defined, densely grafted outer polystyrene by ATRP, which was initiated by the as-synthesized silica-based macroinitiator. FTIR, NMR and gel permeation chro-matography (GPC) were used to characterize the polystyrene/silica hybrid particles.
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