中国概率统计学会(CSPS)和Institute of Mathematical Statistics(IMS)2005年举办CSPS/IMS联合会议征文通知

经CSPS与IMS商定将于2005年在北京联合召开概率统计学术会议.该会议由中国概率统计学会和IMS联合主办,中国现场研究会、中国统计学会和中国统计教育学会协办.现已决定于2005年7月9日-12日(8日报到)在北京大学英杰交流中心举行这次“CSPS/IMS 2005联合会议”.有关会议事宜如下: 1.投稿论文须是2005年7月底以前没有发表的.

Mathematical Statistics Method of Residual Static Torque Controlling

This paper analyzes the problems existing in the detection and determination on the traditional residual torque. It is pointed out that the detection value is mistakenly used as the truth value and the lower limit of design torque is mistakenly used as the residual torque criterion. The calculation formula of the determination （limit） value of the test value of RM and DFM is proposed. By defining related parameters,the torque limitvalue corresponding to the tightening level, the ratio of the measured value to the truth value, μ and σ related tothe ratio of A and C, and the confidence coefficient related to the confidence probability, a mathematical statistical method of residual static torque controlling is established, which improves the control precision on the residual torque.

Rapid Determination of Complete Distribution of Pore and Throat in Tight Oil Sandstone of Triassic Yanchang Formation in Ordos Basin, China

This study aimed to investigate the complete distribution of reservoir space in tight oil sandstone combining casting slices, field emission scanning electron microscopy(FE-SEM), the pore-throat theory model, high-resolution image processing, mathematical statistics, and other technical means. Results of reservoir samples from the Xin’anbian area of Ordos Basin showed that the total pore radius curve of the tight oil sandstone reservoir exhibited a multi-peak distribution, and the peaks appeared to be more focused on the ends of the range. This proved that pores with a radius of 1–50,000 nm provided the most significant storage space for tight oil, indicating that special attention should be paid to this range of the pore size distribution. Meanwhile, the complete throat radius curve of the tight oil sandstone reservoir exhibited a multipeak distribution. However, the peak values were distributed throughout the scales. This confirmed that the throat radius in the tight oil sandstone reservoir was not only in the range of hundreds of nanometers but was also widely distributed in the scale approximately equal to the pore size. The new rapid determination method could provide a precise theoretical basis for the comprehensive evaluation, exploration, and development of a tight oil sandstone reservoir.

NON-LINEAR STOCHASTIC RESPONSE AND ITS EXTREME VALUE OF JACK UP PLATFORMS

The non-linear stochastic response of a jack-up platform subjected to wave load has been analyzed dynamically in this paper, and the analysis method in time domain is considered. Monte Carlo simulation is used to generate random sea. An emphasis is placed on the nonlinear hydrodynamic force. Several distributions for the statistical estimation of extreme responses are compared. For Gumble distribution, the parameters of its asymptotic distribution expression have been checked. The results show that the Gumble distribution agrees well with the simulated values of the responses.

Potential hydraulic connectivity of coal mine aquifers based on statistical analysis of hydrogeochemistry

Mining activities interfere with the natural groundwater chemical environment,which may lead to hydrogeochemical changes of aquifers and mine water inrush disasters.This study analyzed the hydrochemical compositions of 80 water samples in three aquifers and developed a water source identification model to explore the control factors and potential hydraulic connection of groundwater chemistry in a coal mine.The results showed that the hydrochemical types of the three aquifers were different.The main hydrochemical compositions of the loose-layer,coal-bearing,and limestone aquifers were HCO_(3)·Cl-Na,SO_(4)·HCO_(3)-Na,and SO_(4)-Na·Ca,respectively.The correlation,Unmix,and factor an-alyses showed that the hydrochemical composition of groundwater was controlled by the dissolution of soluble minerals(such as calcite,dolomite,gypsum,and halite)and the weathering of silicate minerals.The factor score plot combined with Q-mode cluster analysis demon-strated no remarkable hydraulic connection among the three aquifers in the study area.The water source identification model effectively identified the source of inrush water.Moreover,the mixing ratio model rationally quantified the contributions of the three aquifers to inrush water.

Analysis of High Codimensional Bifurcation and Chaos for the Quad Bundle Conductor＇s Galloping

A two-degree-of-freedom model of iced, electrical quad bundle conductor is developed to comprehensively describe the different galloping behaviors observed. By applying centre manifold and invertible linear transformation, the co-dimension-2 bifurcation is analyzed. The relationships of parameters between this system and the original system are obtained to analyze and to control the galloping of the quad iced bundle conductor. The space trajectory, Lyapunov exponent and Lyapunov dimension are investigated via numerical simulation to present a rigorous proof of existence of chaos.

Fuzzy Modeling and Impulsive Control of a Memristor-Based Chaotic System

We mainly investigate the issues of fuzzy modeling and impulsive control of a memristor-based chaotic system and present a memristor-based chaotic system as the Takagi-Sugeno model-based fuzzy system. Then, based on the impulsive control theory of dynamical systems, a criterion ensuring impulsive stabilization of the memristorbased chaotic system is derived for the first time. An illustrative example is given to verify the effectiveness of the control scheme.

Exact Solutions for Two Equation Hierarchies

Bilinear forms and double-Wronskian solutions are given for two hierarchies, the （2＋1）-dimensional breaking Ablowitz-Kaup-Newell-Segur （AKNS） hierarchy and the negative order AKNS hierarchy. According to some choices of the coefficient matrix in the Wronskian condition equation set, we obtain some kinds of solutions for these two hierarchies, such as solitons, 3ordan block solutions, rational solutions, complexitons and mixed solutions.

Bifurcation Control of Current-Mode Buck Converter via TDFC

Considering the TDFC controlled current-mode Buck converter featuring periodicity we propose a Fourier-decomposition based method for the bifurcation analysis of this system, hence the theoretical range of control gain of TDFC is determined. In addition, the power-stage experiment circuit is built and the control part is realized in a digital controller. The experimental results show that either bifurcation or chaos in the current-mode Buck converter can be controlled into the expectant period-1 orbit rapidly.

Study on Lubricating Oil Monitoring Technology

Lubricating oil monitoring has been proven to be an effective method for detecting and diagnosing machinery failures and essential for realizing condition based maintenance. In this paper, mathematical statistics methods for determining the oil parameters featuring machinery failures and the parameters＇ probability distribution functions and their thresholds are put forward.

A Support Vector Machine Based on Bayesian Criterion

SVM handles classification problem only considering samples themselves and the classification effect depends on the characteristics of the training samples but not the current information of classified problem.From the phenomena of data crossing in systems,this paper improves the classification effect of SVM by adding the prior probability item reflecting the classified problem information into the decision function,which fuses the Bayesian criterion into SVM.The detailed deducing process and realizing steps of the algorithm are put forward.It is verified through two instances.The results showthat the new algorithm has better effect than the traditional SVM algorithm,and its robustness and sensitivity are all improved.

Application of Digital Analysis Technology in Refractory Petrographic Analysis

Six specimens of fused cast AZS 33#material were taken as samples,and their chemical compositions and physical properties（ initial separating temperature o glass phase,corrosion amount in 24 h,glass phase seepage,and bulk density） were tested; low powered backscattered electron images of the samples（ three for each sample） were taken by a scanning electronic microscope with a reinforced backscattering probe. Then,firstly,the images were processed,and the phase compositions（relative contents of pores,matrix,alumina- zirconia eutectoid and primary baddeleyite） of the samples were obtained by counting. Secondly,the correlation coefficients of all parameters were calculated; indistinctive coefficients and unimportant variables were eliminated by F- test. Thirdly,the roadmap of the parameters was established and explained according to professiona knowledge.

Experimental Research on Influence of Some Factors on Ejection Height of Cargo Projectile

Some factors influencing the cargo projectile's ejection height in different conditions were analyzed by using harmonic curve diagram and cluster method.The test results of the ejection height for a certain cargo projectile show that the wind speed and direction are the main influence factors.For given meteorological conditions,the applied environmental stress becomes the main cause,while the launching angle does not influence the ejection height.

Ground State Energy for Fermions in a 1D Harmonic Trap with Delta Function Interaction

Conjectures are made for the ground state energy of a large spin 1/2 Fermion system trapped in a 1D harmonic trap with delta function interaction. States with different spin J are separately studied. The Thomas-Fermi method is used as an effective test for the conjecture.

Ground State Density Distribution of Bose-Fermi Mixture in a One-Dimensional Harmonic Trap

By the density-functional calculation we investigate the ground-state properties of Bose-Fermi mixture confined in one-dimensional harmonic traps. The homogeneous mixture of bosons and polarized fermions with contact interaction can be exactly solved by the Bethe-ansatz method. After giving the exact formula of ground state en- ergy density, we employ the local-density approximation to determine the density distribution of each component. It is shown that with the increase in interaction, the total density distribution evolves to Fermi-like distribution and the system exhibits phase separation between finite. While in the infinite interaction limit both distributions and phase separation disappears. two components when the interaction is strong enough but bosons and fermions display the completely same Fermi-like

Spatial Distribution of Hospitals in Handan City and Its Influencing Factors

Hospital is an important factor of people’s livelihood security,and the spatial layout of hospitals effectively ensures the medical convenience for residents.Location entropy and mathematical statistical analysis are used to study spatial distribution of hospitals.The results display that the distribution of medical facilities in Handan City is at a disadvantage level in Hebei Province,and medical facilities arr concentrated in the plain area.The layout of grade 3A hospitals in Hebei Province is characterized by urban centralization,and it is stronger in the east and weaker in the west.There is no medical facilities in Feixiang District of Handan City,and layout of medical facilities in Hanshan District and Congtai District is at advantage level of Handan City.The built-up area is the influencing factor for the distribution of medical resources.

Modulational Instability and Variable Separation Solution for a Generalized （2＋1）-Dimensional Hirota Equation

It is demonstrated by the linear modulational instability analysis that a generalized （2＋1）-dimensional Hirota equation is modulationally stable. Then, a B？cklund transformation （BT） is obtained by means of the truncated Painlevé approach. Using the BT, the model is transformed to a system of equations, which finally leads to a special variable separation solution with arbitrary functions.

Structure Identification of Nonlinearly Coupled Complex Networks with Non-Delayed and Delayed Coupling

Topology identification is an important problem for complex networks because much information about networks in practice such as the topological structure is uncertain. We propose an adaptive control method for identifying the topology of general nonlinearly-coupled complex network models that are either non-delayed or delayed coupled. Simulation results are also presented to illustrate the effectiveness of the method.

An Analysis of the Invariance and Conservation Laws of Some Classes of Nonlinear Ostrovsky Equations and Related Systems

A large class of partial differential equations in the modelling of ocean waves are due to Ostrovsky. We determine the invariance properties （through the Lie point symmetry generators） and construct classes of conservation laws for some of the models. In the latter case, the method involves finding the ＇multipliers＇ associated with the conservation laws with a stronger emphasis on the ＇higher-order＇ ones. The relationship between the symmetries and conservation laws is investigated by considering the invariance properties of the multipliers.

A Simple Method for Generating Discrete Multi-Component Integrable Hierarchy

For M×N spectral matrix, a kind of operation ？ which satisfies combination law （a？b）？c=a？（b？c） is introduced. The discrete multi？component zero-curvature equation is deduced by using the new operation ？, and a simple method for constructing discrete multi-component integrable hierarchy is proposed. As its application, the multi-component Toda hierarchy and its two kinds of integrable couplings are worked out.