A PROBABILISTIC PRODUCTION COSTING FOR MULTISTATES AND MULTIBLOCKS OF UNITS

A probabilistic production costing method for multistates and multiblocks of units is presented in this paper. The mixtures of normal distributions are used to represent the power of the system and the load. The energy, reliability and production costs are calculated directly from the analytical formulae. Numeral examples demonstrate that the algorithm presented in the paper is accurate and efficient.     

THE COMPARISON OF TWO METHODS FOR LOAD EXPRESSION IN PRODUCTION SIMULATION

Two methods for load expression in production simulation are studied,and the errors are analyzed and compared when the two methods are used in the direct method of probabilistic production simulation.     

A Method of Modeling with Structural Stochastic Parameters

In order to reflect the stochastic characteristic of a structure more completely and accurately,this paper presents a theory and method of modeling with structural stochastic parameters using probabilistic finite element method and perturbant finite element method,on the basis of modeling with deterministic parameters.It is applied to double decker space frame,good results are gained.     

DIRECT METHOD OF PROBABILISTIC PRODUCTION SIMULATION BASED ON MIXTURES OF NORMAL DISTRIBUTIONS

This paper describes a new probabilistic production simulation method based on mixtures of normal distributions. This method does not require to modify the original load,and the relevant formulae are derived directly from the mixture of normal distributions of load and the mixture of normal distributions of system power. Numerical results indicate that this method is accurate and rapid in comparison with the conventional and the cumulant methods.     

The Probabilistic Production Simulation for the Joint Dispatch of Multi Area Interconnected Power System

In this paper,a probabilistic production simulation for the joint dispatch of multi area interconnected power system is presented.The method evaluates the expected unserved energy of the joint dispatch system and further the other basic simulation indices,based on the probability density function of the unit available capacity and the multi area demand supply feasibility conditions,and the detail is showed by a four areas case.     

刚性陶瓷瓦热防护系统概率设计分析方法

针对高超声速飞行器中广泛应用的陶瓷瓦热防护系统,结合有限元法和蒙特卡洛模拟建立了其概率热分析系统,提出了刚性陶瓷瓦热防护系统尺寸概率设计方法。建立了刚性陶瓷瓦热防护系统的二维有限元模型,考虑了热传导系数、比热容和表面辐射率等材料属性参数以及热防护系统各层厚度的不确定性,得到系统温度场的概率分布特性和系统热防护性能对各参数的灵敏度,并对系统的热可靠性进行了评估。算例表明：文中提出的方法对热防护系统设计过程中合理确定陶瓷瓦厚度和在保证系统性能的前提下有效减轻重量具有指导价值。     

Refined Probabilistic Model of Resistance of RC Eccentric Compression Members

The probabilistic model of resistance in the current unified standard for reliability design is imprecise for RC members subjected to eccentric compression. The reason is that it lacks full considerations of influences of varying eccentricities. An improved probabilistic model of resistance with different eccentricities and reinforcement ratios is obtained by using the Monte Carlo sampling method and the current probabilistic models of all resistant factors. The results indicate that it is accurate to fit the probabilistic distribution of resistance with normal distribution. Given that, the applicability of the improved model is analyzed for reliability analysis of RC members subjected to eccentric compression with random eccentricities. It shows that when the design value of eccentricity is close to or larger than the eccentricity producing balanced failure, there would be large errors in reliability analysis if the probabilistic model of resistance given in the current reliability unified standard is used. However, it is accurate when using the proposed probabilistic model. The results also show that the design of RC members subjected to large eccentric compression is unsafe based on the current reliability unified standard because it lacks full considerations of effects that the resistance decreases as eccentricity increases.     

A Study on Chaotic State of EEG Signal

In this paper.the chaotic theory is described briefly and the chaotic state ofEEG on thinking are studied. In this study. the method of detecting short bursts of 40 Hz EEG ac-tivity is firstly usedto dedermine the segments to be computed for analysis of the chaotic state ofEEG. therefore the reliability and stability of the analysis results are assured In this paper.thechaotic para meters of qa n titative analysis are studied and more then 30 subjects EEG are analysedfor the value of the fractional dimension and the maximal Lyapunov exponent.The results of exper-iments indicate that the value of the fractional dimension is valuable for clincal diagnosis and themaximal Lyapunov exponent is not sufficient for dignosis of disease.     

A Simulative Method of Investment Decision in Real Estate Development

This paper has simulated major risk factors and estimation indexes which influence on project investment in real estate development. It confirms the scope of risk factors by reaching it's reliability, The problems are resolved in obtaining values of factors and it's probabilistic distributing;the limitation is over come in estimating the income of investment by a point-estimation.An impersonal and reliable method of investment decision is provided in real estate development, and the result is ideal in practive test.     

PRACTICAL DESIGN OF PROBABILISTIC LIMIT STATES FOR STEEL STRUCTURES OF TALL BUILDING

For design purposes, this paper presents performance coefficients for steel structures of tall building, and furthermore design values of strength of heavy plates. The calculated results show that suggested coefficients meet the requirements of probabilistic limit states design method. They can serve as a supplement to GBJ17-88 and the expression of limit states design provided in this paper is available for reference in compilation of concerned standard.     

Application of Revised BP -NN Method to Landslide Stability Analysis in the Three Gorges Area

Using the revised BP-NN,this paper presented the neural network method for landslide stability analysis in the Three Gorges area.By choosing 30 typical landslides in this area as examples,the stability state estimated by the revised BP-NN method is highly consistent to that by conventional transfer coefficient method.And the method presented in this paper has following advantages:the input parameters are easily obtained and this method does not deeply rely on investigation quality and shear strength parameters of slips and is a quite simple one.The BP-NN method is a new measure to stability analysis of landslides in the Three Gorges area,which is especially suitable to the stability prediction of landslides before investigation.     

Study on Cusp Catastrophe Mutation of Slope Destability

A complete theoretical model for slope destabilizing mutation has been set up by studying the geomechanical model and the influences of all circumstantial factors on slope stability,and by applying nonlinear theory.This paper analyzed the influence of controlled variables in the mutation model on the slope in causing slow or fast creeping.As the limit equilibrium stability analysis method of rigid bodies has some defects in slope stability assessment,the new theory of rigidity destabilization is helpful in forming criteria for judging slope creep destabilization.This analysis explains well the underlying causes of creeping slope destabilization and proves the feasibility of studying slope creep with a mutation model.     

Probability Analysis of "Strong Beam and Weak Beam" and Axial Compression Ratio in RC Frame

In the view of reliability calibration, this paper analyzes the probabilistic sense of the provisions of "Strong Column and Weak Beam' and axial compression ratio in aseismic criteria (GBJ 11 89), which demonstrates that there is much difference between different aseismic ranks of RC frame. The authors suggest that it is possible to make axial compression ratio larger by adjusting the moment capacity ratio between column and beam. Finally, the direction and method of further studies are proposed.     

品种稳定性评价方法的比较和分析

本文利用1962～1964年黄淮冬麦区区域试验17个环境,6个品种的资料分析了所选取的9种不同的评价品种稳定性方法。每种方法都可以得出一种品种稳定性序列。然后比较9种不同方法的结果以及与品种实际推广情况的差异,同时从理论上分析它们的优劣。结果表明这些方法在确定品种稳定性方面作用相似。回归法较非回归法精确。在回归中,     

Research on reliability evaluation model for frequency collapse of power grid

In order to comprehensively consider the possibility and the severity of frequency instability risk, this paper proposes the risk evaluation model and algorithm for frequency collapse of power grid. The uncertainties in generating dispatch, network topology and component outage are considered. The calculation method for system frequency variation is depicted while considering the active power deficiency arising from random failure of generating units, and then various probabilistic risk indices for frequency collapse are defined. The presented method can provide important reference information for evaluating the frequency collapse risk of power grid. The non-sequential Monte Carlo simulation-based results of IEEE-RTS79 show the correctness of the method.     

The Model and Algorithm of Capacity Balance

In this paper,more carefully study has been discussed to the traditional MRP capacity cutting method ,the default is found. The optimizing thought is introduced in capacity cutting .A mathematical model of this problem is established . Base on this model, a new scheduling algorithm is put forward.     

The Recent Progress of the Slope Stability Analysis Methods

The slope stability is an important research content in rock mechanics. In recent years, the great achievement has been gained for the slope stability analysis methods. The deterministic analysis methods, including limit equilibrium theory, numerical analysis method, graphic method and compound method, have been developed. The stochastic analysis method and the fuzzy analysis method come forward. The recent progress of the slope stability analysis methods is analyzed in this paper. The trend of progress of the slope stability is studied.     

ANTICIPATED FAIIURE ANALYSIS OF HVAC/DC HYBRID SYSTEMS

A method of anticipated failure analysis(AFA)in HV AC/DC hybrid systems is presented in this paper for the first time. In this method node-injection-power is used to simulate outage states of AC/DC branch circuits, linked with the fast decoupled load flow, to obtain the load flow solutions after the anticipated failures. An example for calculation in this paper shows the effectiveness and correctness of this method and computer programs.     

Effects of Response Spectra Dispersion of Earthquake Ground Motions on Probabilistic Seismic Demand Assessment of Bridge Structures

A three-span regular continuous RC girder highway bridge and two bins of real accelerograms were selected for incremental dynamic analysis to study the correlation of the dispersions of response spectra of earthquake ground motions and probabilistic seismic demand assessments of bridge structures. It is found that the dispersions of seismic demands are closely related to the dispersions of response spectra of selected ground motions. The rational selection of real earthquake ground motions to be rationally chosen for dynamic analysis can make the probability distribution of seismic demands in accordance with the real situation and improve the computational precision and efficiency of the probabilistic seismic demand assessment and fragility curve for performance-based earthquake engineering and seismic design of bridges based on probability theory.     

A STRUCTURAL NON-LINEAR DYNAMIC STABILITY AND A MATRIX FUNCTION METNOD

This paper presents a mathematical and mechanic model for non-linear dynamicstability analysis of structures on the basis of Liapunov's stability criteria. Due to the complexityand difficulty in numerical calculation,a matrix function to this type of stability problems is selectedand the programing formulations are derived.Applying the method to beam or frame structures un-der the axial period loadings,the geometric non-linear dynamic stability results are obtained.Fromthe results,the basic characteristics of this type of probtems,especially the non-linear effect areshown.The model and matrix function method are valtiable both in theory and in practice for struc-tural non-linear dynamic stability.