一种基于802.1x的双向认证方法及其形式语义分析

提出一种基于IEEE802.1x协议的双向认证方法,该方法在一个认证流程内实现客户实体与认证服务器之间和客户实体与认证实体之间的双向认证,以及客户实体与认证实体之间共享密钥的成功分发。通过对安全性的形式语义分析,结果表明该方法成功实现客户实体与认证服务器之间和客户实体与认证实体之间的相互信任。

Key parameter optimization and analysis of stochastic seismic inversion

Stochastic seismic inversion is the combination of geostatistics and seismic inversion technology which integrates information from seismic records, well logs, and geostatistics into a posterior probability density function （PDF） of subsurface models. The Markov chain Monte Carlo （MCMC） method is used to sample the posterior PDF and the subsurface model characteristics can be inferred by analyzing a set of the posterior PDF samples. In this paper, we first introduce the stochastic seismic inversion theory, discuss and analyze the four key parameters： seismic data signal-to-noise ratio （S/N）, variogram, the posterior PDF sample number, and well density, and propose the optimum selection of these parameters. The analysis results show that seismic data S/N adjusts the compromise between the influence of the seismic data and geostatistics on the inversion results, the variogram controls the smoothness of the inversion results, the posterior PDF sample number determines the reliability of the statistical characteristics derived from the samples, and well density influences the inversion uncertainty. Finally, the comparison between the stochastic seismic inversion and the deterministic model based seismic inversion indicates that the stochastic seismic inversion can provide more reliable information of the subsurface character.

ESSENTIAL RELATIONSHIP BETWEEN DOMAIN-BASED ONE-CLASS CLASSIFIERS AND DENSITY ESTIMATION

One-class support vector machine （OCSVM） and support vector data description （SVDD） are two main domain-based one-class （kernel） classifiers. To reveal their relationship with density estimation in the case of the Gaussian kernel, OCSVM and SVDD are firstly unified into the framework of kernel density estimation, and the essential relationship between them is explicitly revealed. Then the result proves that the density estimation induced by OCSVM or SVDD is in agreement with the true density. Meanwhile, it can also reduce the integrated squared error （ISE）. Finally, experiments on several simulated datasets verify the revealed relationships.

Security of Application System

A safe and reliable application system frame based on Internet and Intranet for Stock Supervision and Administration Council of China is built up. An all sided, multi tier and multi technical security method has been adopted, which includes identity recognition, data encryption, digital signature, Domino and WWW servers, access control list, directory service, certificate authorization server, IC card and so on. The recognition system based on CA server is a high efficient, convenient and reliable system. The encryption technology and security method are proved to be reliable. The recognition system is of high security and is worthy of being popularized in some places where some special security requirements need meeting. Multi tier technology can improve the security of database. Double keys method is a useful data encryption method.

Adaptive and Dynamic Mobile Phone Data Encryption Method

To enhance the security of user data in the clouds,we present an adaptive and dynamic data encryption method to encrypt user data in the mobile phone before it is uploaded.Firstly,the adopted data encryption algorithm is not static and uniform.For each encryption,this algorithm is adaptively and dynamically selected from the algorithm set in the mobile phone encryption system.From the mobile phone's character,the detail encryption algorithm selection strategy is confirmed based on the user's mobile phone hardware information,personalization information and a pseudo-random number.Secondly,the data is rearranged with a randomly selected start position in the data before being encrypted.The start position's randomness makes the mobile phone data encryption safer.Thirdly,the rearranged data is encrypted by the selected algorithm and generated key.Finally,the analysis shows this method possesses the higher security because the more dynamics and randomness are adaptively added into the encryption process.

Optimal trajectory planning based on Hamiltonian function of a spherical mobile robot

Designed for planetary exploration,a spherical mobile robot BHQ-1 was briefly introduced.The mo-tion model of BHQ-1 was established and quasi-velocities were introduced to simplify some dynamic quan-tities.Based on the model,the time- and energy-based optimal trajectory of BHQ-1 was planned withHamiltonian function. The effects of three key coefficients on the shape and direction of the planned tra-jectory were discussed by simulations.Experimental result of the robot ability in avoiding an obstacle waspresented to validate the trajectory planning method.

Voice activity detection based on deep belief networks using likelihood ratio

A novel technique is proposed to improve the performance of voice activity detection(VAD) by using deep belief networks(DBN) with a likelihood ratio(LR). The likelihood ratio is derived from the speech and noise spectral components that are assumed to follow the Gaussian probability density function(PDF). The proposed algorithm employs DBN learning in order to classify voice activity by using the input signal to calculate the likelihood ratio. Experiments show that the proposed algorithm yields improved results in various noise environments, compared to the conventional VAD algorithms. Furthermore, the DBN based algorithm decreases the detection probability of error with [0.7, 2.6] compared to the support vector machine based algorithm.

Numerical Analysis of the Thermal Behavior of a Hermetic Reciprocating Compressor

A numerical model to predict the temperature field in a hermetic reciprocating compressor for household refrigeration appliances is presented in this work. The model combines a high resolution three-dimensional heat conduction formulation of the compressor＇s solid parts, a three-dimensional CFD （computational fluid dynamics） approach for the gas line domain and lumped formulations of the shell gas and the lubrication oil. Heat transfer coefficients are determined by applying CFD to the gas line side and correlations from the literature on the shell gas and oil side, respectively. The valve in the gas line simulation is modelled as a parallel moving fiat plate. By means of an iterative loop the temperature field of the solid parts acts as boundary condition for the CFD calculation of the gas line which returns a cycle averaged quantity of heat to the solid parts. Using an iteration method which is based on the temperature deviation between two iteration steps, the total number of iterations and consequently the computational time can be reduced. The loop is continued until a steady-state temperature field is obtained. Calculated temperatures of the solid parts are verified by temperature measurements of a calorimeter test bench.

Theoretical study on separation density of gravity beneficiation

Separation density is one of the most concerned operating parameters in gravity beneficiation.Although equal-errors cut point or distribution density is usually used as practical separation density in gravity beneficiation, the gravity separating process complexly affected by many kinds of factors is actually carried out at a fluctuant density; namely, the practical separation density is essentially a random variable.The studied results show that the equal-errors cut point is the mathematical expectation of this random variable, and the distribution density corresponds to the highest separation efficiency in the gravity separation process.This shows that the distribution density is the best working point of the gravity separation equipment under a particular operating condition.Therefore,in order to fully develop the function of the gravity separation equipment, the distribution density should be close to the theoretical separation density unlimitedly in the range of minimum fluctuation.

Mechanism of Bragg Diffraction-Assisted Light Extraction in GaN-based Light-Emitting Diodes Based on a Self-Consistent Model

By introducing the distribution of the light energy density in GaN-based light-emitting diode (LED),theLED model based on the incoherent regime and the light extraction efficiency are investigated.The energy density asa function of the angle of incidence is calculated to demonstrate the mechanism of the light extraction.The deviationbetween the tendencies of the transmissivity of the output layer and the extraction efficiency is also demonstrated.

A Survey on Device-Independent Quantum Communications

Quantum communications helps us to enhance the security and efficiency of communications and to deepen our understanding of quantum physics. Its rapid development in recent years has attracted the interest of researchers from diverse fields such as physics, mathematics, and computer science. We review the background and current state of quantum communications technology, with an emphasis on quantum key distribution, quantum random number generation, and a relatively hot topic: device independent protocols.

Numerical simulation of flocculation and settling behavior of whole-tailings particles in deep-cone thickener

Rapid dewatering and thickening of whole-tailings with ultrafine particles is one of the most important processes for the whole-tailings paste preparation. Deep-cone thickener, a kind of such process for the flocculation and settling of whole-tailings, is particularly necessary to study. However, there exist many problems in observing the flocculation and settling process of whole-tailings, as well as the particle size distribution(PSD) of whole-tailings floccules in deep-cone thickener. Population balance model(PBM) is applied to predict the PSD in deep-cone thickener, and LUO model and GHADIRI model are employed to study the aggregation and fragmentation mechanism of the whole-tailings particles, respectively. Through three-dimensional numerical simulation on the whole-tailings flocculation and settling in deep-cone thickener using computational fluid dynamics(CFD)-PBM, the distribution of density and turbulent kinetic energy in deep-cone thickener were obtained, at the same time the spatio-temporal changes of whole-tailings floccules particle size distribution are analyzed. Finally, the major flocculation position in deep-cone thickener is found and the flocculation settling rules of whole-tailings are achieved.

Applying the Non-homogeneous Stochastic Gompertz Process for Modeling Populations

It is a well known fact that studies on growth primarily take into account human populations, although currently many scientific fields （biology, economics, etc.） also use growth models to reflect behaviours in diverse phenomena. These deterministic models are difficult to apply in real populations since, as we know, the volume of a human population depends intrinsically on a large number of other socio-economic variables, including changes in fertility patterns, improvements in living conditions, individual health factors which produce an increase or decrease in the number of years lived, the state of economic well-being, or changes in migratory fluxes. In this study, we have examined the stochastic Gompertz non-homogenous diffusion process, analysing its transition probability density function and conducting inferences on the parameters of the process through discrete sampling All of the results are applied to the population of Andalusia with data disaggregated by sex during the period of 1981 to 2002, taking purely demographic variables as exogenous factors： life expectancy at birth, foreign immigration to Andalusia and total fertility rate

A NOVEL RESEARCH OF CONFIDENTIAL COMMUNICATION BASED ON THE ELLIPTIC CURVE AND THE COMBINED CHAOTIC MAPPING

This letter presents a new type of chaotic encryption system based on combined chaotic mapping pseudo-random number generator, Hash table, and elliptic curve. In this program, the elliptic curve algorithm is used for the key distribution. After the linear transformation, the original chaotic sequence generated by drive system will be combined to chaotic mapping, converted to an encryption key sequence and constructed as Hash table for message authentication. The communication experiment used in the letter proves that the combination of combined chaotic encryption and conventional encryption is safe, feasible, and easy to implement by software.

A Generalized Equation of State for High-Pressure Liquids

An equation of state （EOS） for high-pressure liquids, i.e., Tait EOS, is deduced according to isothermal 1 3V compressibility KT= -1/V· （2V/2p）T·.Based on the equation, a generalized EOS for high pressure-liquids is established by using the reduced state principle and introducing a characteristic parameter-configuration factor ξ. Reasonably satisfactory P-V-T data for many organic compounds, including some polar components, were calculated by using the equation.

Ultra-fast Maize （Zea mays L.） Hybrid Growth Response to Plant Population Density

Current arable land and increasing food demand necessitates the practice of double and multiple cropping systems with inclusion of ultra-fast maize hybrids, which are characterized by smaller size, fewer leaves per plant, lower leaf area and fewer self-shading problems, under irrigation. In this context, a field experiment was conducted for two successive cropping seasons 2008/2009 to 2009/2010 at Kenilworth Experimental Station to evaluate the effect of row spacings and plant density on growth. Three row spacing （0.225, 0.45 and 0.90 m） and five plant densities （5, 7.5, 10, 12.5 and 15 plants m^-2） were used. Treatments were combined in a factorial combination and laid out in a completely randomized design with replications consisting of five single plants randomly selected from each treatment for destructive sampling. Growth factors reacted differently to row spacing by plant density. At crop establishment, growth indicators were not significantly affected by either main effects or a combination thereof. However, at the end of the vegetative phase, almost all growth indicators reached a maximum and were significantly affected by treatment interactions. Growth analysis showed that there was an interaction effect of row spacing by plant density on plant height, dry matter （DM） accumulation, leaf area index （LAI）, crop growth rate （CGR） and net assimilation rate （NAR） of maize. Therefore, the current investigation demonstrated that a row spacing of 0.45 m or 0.90 m with a plant density of 10 plants m^-2 was optimum for the selected ultra-fast maize hybrid under irrigation.

Validating Wind Energy Probability at Ahmednagar Wind Farm

The wind speed is measured with the help of three anemometers S30, S45, S60 placed at 30 m, 45 m, and 60 m height. Mean values are recorded and stored for every hour using a data logger. For accounting wind turbine generator （WTG.） tower height, data recorded from S60 anemometer at 60 m height is used for analysis purpose. This paper analyzes the probability distribution of wind speed data recorded by maharashtra energy development agency （MEDA） wind farm at Ahmednagar （India）. The main objective is to validate the wind energy probability by using probability distribution function （PDF） of available wind potential. The energy generated from wind for any time interval is equal to the area tinder power curve multiplied by time in hours for that time interval. To estimate the wind energy probability, hourly wind speed data tbr one year interval is selected. Weibull distribution is adopted in this study to best fit the wind speed data. The scale and shape paranleters are estimated by using maximum likelihood method. The goodness of fit tests based on the probability density function （PDF） is conducted to show that the distribution adequately fits the data. It is found from the curve fitting test that, although the two distributions are all suitable for describing the probability distribution of wind speed data, the two-parameter weibull distribution is more appropriate than the lognormal distribution.

Study on Programming of CNC Turning and Processing Techniques

Due to its high efficiency, high precision and high flexibility, CNC lathe is widely used in the machinery manufacturing industry increasingly, and becomes one of CNC machine too[s that most widely used. However, to give full play to the role of CNC lathes, the key is programme, that is, preparing the reasonable and efficient processing procedures depending on the features and precision parts. This paper discussed the problems of programming and processing techniques of the CNC lathe parts.

Regional Simulation of Soil Organic Carbon Dynamics for Dry Farmland in East China by Coupling a 1:500000 Soil Database with the Century Model

Changes in soil organic carbon (SOC) in agricultural soils influence soil quality and greenhouse gas concentrations in the atmosphere. Dry farmland covers more than 70% of the whole cropland area in China and plays an important role in mitigating carbon dioxide (CO2) emissions. In this study, 4109 dry farmland soil polygons were extracted using spatial overlay analysis of the soil layer (1:500000) and the land use layer (1:500000) to support Century model simulations of SOC dynamics for dry farmland in Anhui Province, East China from 1980 to 2008. Considering two field-validation sites, the Century model performed relatively well in modeling SOC dynamics for dry farmland in the province. The simulated results showed that the area-weighted mean soil organic carbon density (SOCD) of dry farmland increased from 18.77 Mg C ha1 in 1980 to 23.99 Mg C ha1 in 2008 with an average sequestration rate of 0.18 Mg C ha1 year?1. Approximately 94.9% of the total dry farmland area sequestered carbon while 5.1% had carbon lost. Over the past 29 years, the net SOC gain in dry farmland soils of the province was 19.37 Tg, with an average sequestration rate of 0.67 Tg C year1. Augmentation of SOC was primarily due to increased consumption of nitrogen fertilizer and farmyard manure. Moreover, SOC dynamics were highly differentiated among dry farmland soil groups. The integration of the Century model with a fine-scale soil database approach could be conveniently utilized as a tool for the accurate simulation of SOC dynamics at the regional scale.

Stationary Response of Lotka-Volterra System with Real Noises

A stochastic version of Lotka-Volterra model subjected to real noises is proposed and investigated. The approximate stationary probability densities for both predator and prey are obtained analytically. The original system is firstly transformed to a pair of It6 stochastic differential equations. The It6 formula is then carried out to obtain the It6 stochastic differential equation for the period orbit function. The orbit function is considered as slowly varying process under reasonable assumptions. By applying the stochastic averaging method to the orbit function in one period, the averaged It6 stochastic differential equation of the motion orbit and the corresponding Fokker-Planck equation are derived. The probability density functions of the two species are thus formulated. Finally, a classical real noise model is given as an example to show the proposed approximate method. The accuracy of the proposed procedure is verified by Monte Carlo simulation.