A Skorokhod Problem formulation and large deviation analysis of a processor sharing model

Generalized processor sharing has been proposed as a policy for distributing processing in a fair manner between different data classes in high-speed networks. In this paper we show how recent results on the Skorokhod Problem can be used to construct and analyze the mapping that takes the input processes into the buffer content. More precisely, we show how to represent the map in terms of a Skorokhod Problem, and from this infer that the mapping is well defined (existence and uniqueness) and well behaved (Lipschitz continuity). As an elementary application we present some large deviation estimates for a many data source model. This revised version was published online in June 2006 with corrections to the Cover Date.     

Isolation of very volatile compounds from the leaves ofLedum palustre using the purge & trap technique

Summary A comparison of different isolation methods for volatile compounds from the leaves ofLedum palustre has been carried out. The aim of the investigation was not to identify all the isolated compounds, though some new compounds were found. Methods used were steam distillation, Soxhlet extraction with n-hexane and the purge & trap technique.The results obtained by the three methods of extraction were compared and it is was found that the very volatile compounds isolated by the purge & trap technique, could not be found by the more conventional methods. The very volatile compounds found by the purge & trap technique were mainly dienals.     

基于网格模式的电子商务技术应用与研究

针对目前电子商务应用中存在的信息孤岛和资源瓶颈问题,应用网格技术方法,提出了基于网格模式下的电子商务模型;依据网格模型,提出了基于该模型的电子商务系统的体系结构、分层特性以及初步的设计和实现方案;最后,展望了电子商务应用未来的发展趋势.     

The stopped-flow technique in analytical chemistry

A critical survey of the stopped-flow technique is presented. The instrumentation typically used and the scope of its analytical applications are discussed. The stare-of-the-art of this technique and its wide possibilities in routine analyses are also considered.     

Living radical emulsion polymerization using the nanoprecipitation technique: An extension to atom transfer radical polymerization

Living radical polymerizations of styrene were performed under emulsion atom transfer radical polymerization conditions with latexes prepared by a nanoprecipitation technique recently developed for the stable free‐radical polymerization process. Latexes were prepared by the precipitation of a solution of low‐molecular‐weight polystyrene in acetone into a solution of a surfactant in water. The resulting particles were swollen with styrene and then heated. The effects of various surfactants and hydrophobic ligands, the reaction temperature, and the ligand/copper(I) bromide ratio were studied. The best results were obtained with the nonionic surfactant Brij 98 in combination with the hydrophobic ligand N,N‐bis(2‐pyridylmethyl)octadecylamine and a ligand/copper(I) bromide ratio of 1.5 at a reaction temperature of 85–90 °C. Under these conditions, latexes with good colloidal stability with average particle diameters of 200 nm were obtained. The molecular weight distributions of the polystyrenes were narrow, although the experimental molecular weights were slightly larger than the theoretical ones because not all the macroinitiator appeared to reinitiate. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4027–4038, 2006     

Secret sharing schemes on access structures with intersection number equal to one

The characterization of ideal access structures and the search for bounds on the optimal information rate are two important problems in secret sharing. These problems are studied in this paper for access structures with intersection number equal to one, that is, structures such that there is at most one participant in the intersection of any two different minimal qualified subsets. The main result in this work is the complete characterization of the ideal access structures with intersection number equal to one. In addition, bounds on the optimal information rate are provided for the non-ideal case.     

Cheating in Visual Cryptography

A secret sharing scheme allows a secret to be shared among a set of participants, P, such that only authorized subsets of P can recover the secret, but any unauthorized subset cannot recover the secret. In 1995, Naor and Shamir proposed a variant of secret sharing, called visual cryptography, where the shares given to participants are xeroxed onto transparencies. If X is an authorized subset of P, then the participants in X can visually recover the secret image by stacking their transparencies together without performing any computation. In this paper, we address the issue of cheating by dishonest participants, called cheaters, in visual cryptography. The experimental results demonstrate that cheating is possible when the cheaters form a coalition in order to deceive honest participants. We also propose two simple cheating prevention visual cryptographic schemes.     

A bidirectional hybrid DWDM-PON employing optical injection locking technique and data comparators

A bidirectional hybrid dense-wavelength-division-multiplexing (DWDM)-passive optical network (PON) employing optical injection locking technique on vertical-cavity surface-emitting lasers (VCSELs) and data comparator, as well as optical injection locking technique on distributed feedback laser diodes (DFB LDs) and amplitude/phase compensator is proposed and demonstrated. Improved performances of bit error rate (BER) and carrier-to-noise ratio/composite second order/composite triple beat (CNR/CSO/CTB) were observed in our proposed bidirectional hybrid DWDM-PON. Bidirectional transmission in bidirectional hybrid DWDM-PON architecture is a very attractive option, the capacity of the optical network can be expanded relatively easily by bidirectional transmission technology.     

DPSM technique for ultrasonic field modelling near fluid-solid interface

Distributed point source method (DPSM) is gradually gaining popularity in the field of non-destructive evaluation (NDE). DPSM is a semi-analytical technique that can be used to calculate the ultrasonic fields produced by transducers of finite dimension placed in homogeneous or non-homogeneous media. This technique has been already used to model ultrasonic fields in homogeneous and multi-layered fluid structures. In this paper the method is extended to model the ultrasonic fields generated in both fluid and solid media near a fluid-solid interface when the transducer is placed in the fluid half-space near the interface. Most results in this paper are generated by the newly developed DPSM technique that requires matrix inversion. This technique is identified as the matrix inversion based DPSM technique. Some of these results are compared with the results produced by the Rayleigh-Sommerfield integral based DPSM technique. Theory behind both matrix inversion based and Rayleigh-Sommerfield integral based DPSM techniques is presented in this paper. The matrix inversion based DPSM technique is found to be very efficient for computing the ultrasonic field in non-homogeneous materials. One objective of this study is to model ultrasonic fields in both solids and fluids generated by the leaky Rayleigh wave when finite size transducers are inclined at Rayleigh critical angles. This phenomenon has been correctly modelled by the technique. It should be mentioned here that techniques based on paraxial assumptions fail to model the critical reflection phenomenon. Other advantages of the DPSM technique compared to the currently available techniques for transducer radiation modelling are discussed in the paper under Introduction.     

Influence of thermophoretic diffusion of nanoparticles with Joule heating in flow of Maxwell nanofluid

The aspects of activation energy in magnetized Maxwell nanofluid flow with Brownian movement and thermophoretic diffusion have been elaborated here. Furthermore, Joule heating, variable conductivity and chemical reaction are scrutinized. The Buongiorno nanofluid thought is ratify to incorporate the importance of thermophoretic and Brownian diffusion. The attained ODEs have been solved via homotopic algorithm. The performance of operational variables is inspected. The Maxwell temperature field for Eckert number and variable conductivity factor have similar trend. The fluid concentration exaggerates for activation energy and decelerates for Brownian motion parameter. Furthermore, the brilliant outcomes attained and associated with possible existing prose accurately.