Reliability Sensitivity-based Correlation Coefficient Calculation in Structural Reliability Analysis

The correlation coefficients of random variables of mechanical structures are generally chosen with experience or even ignored,which cannot actually reflect the effects of parameter uncertainties on reliability.To discuss the selection problem of the correlation coefficients from the reliability-based sensitivity point of view,the theory principle of the problem is established based on the results of the reliability sensitivity,and the criterion of correlation among random variables is shown.The values of the correlation coefficients are obtained according to the proposed principle and the reliability sensitivity problem is discussed.Numerical studies have shown the following results：（1） If the sensitivity value of correlation coefficient ρ is less than（at what magnitude 0.000 01）,then the correlation could be ignored,which could simplify the procedure without introducing additional error.（2） However,as the difference between ρs,that is the most sensitive to the reliability,and ρR,that is with the smallest reliability,is less than 0.001,ρs is suggested to model the dependency of random variables.This could ensure the robust quality of system without the loss of safety requirement.（3） In the case of ｜Eabs｜ρ0.001 and also ｜Erel｜ρ0.001,ρR should be employed to quantify the correlation among random variables in order to ensure the accuracy of reliability analysis.Application of the proposed approach could provide a practical routine for mechanical design and manufactory to study the reliability and reliability-based sensitivity of basic design variables in mechanical reliability analysis and design.

EXPERT SYSTEM AND ITS APPLICATION IN THE SELECTION OF PIT RETAINING STRUCTURES

This paper describes the development of an expert system(ES) on earth retaining structures for the selection and design.The ES retaining is an interactive menudriven system and consists of two main parts—the selection part,selectwall and the design part.Selectwall is developed using the knowledge base and it makes a choice of the most appropriate retaining structure.The design part is developed by three independent subprograms which perform detailed design including strength,deformation,stability of the retaining structure.The calculation results are illustrated by plotting the diagram.Using this program,the design procedure of the retaining structure can be performed automatically.

POLYMORPH CONTROL OF ANTIMONY WHITE(Sb_2O_3)PREPARED BY HYDROMETALLURGY METHOD

The effects of reaction solvent, the properties of Sb 4O 5Cl 2 material and the ligand additives on the reaction rate and polymorph of antimony white(Sb 2O 3) in the reaction of Sb 4O 5Cl 2 transforming into Sb 2O 3 have been investigated by XRD and IR method. It is revealed that the reaction solvent and the properties of Sb 4O 5Cl 2 are the key factors affecting the reaction rate. The polymorph of antimony trioxides is determined by the reaction mechanism, i.e. the coordination state of the antimony activated complex. Adding a little ligand such as EDTA is the most economical and effective method of synthesizing cubic antimony white(Sb 2O 3)in hydrometallurgical transformation process.

An Orthogonal Least Squares Based Approach to FIR Designs

This paper is concerned with the application of forward Orthogonal Least Squares (OLS) algorithm to the design of Finite Impulse Response (FIR) filters. The focus of this study is a new FIR filter design procedure and to compare this with traditional methods known as the fir2() routine provided by MATLAB.

Research on key technologies in design of middle pylon of Taizhou Bridge

At the middle pylon of a three-pylon two-span suspension bridge, the effect of unbalanced loads on the adjacent spans may result in a series of technical bottlenecks in design, such as stability and anti-slippage between saddles and main cables. This article presents the researches conducted on structure selection and behavior characteristics of middle pylon, interaction mechanism between main cables and saddles and their anti-slippage safety performance, elastic and plastic stability analysis and safety assessment of steel middle pylon, and fatigue design load and method for steel pylon of Taizhou Bridge. According to the research results, a longitudinal inverted Y shape steel middle pylon is used in design, effectively solving many technical difficulties, and this type of pylon has become a suitable middle pylon structural form for many three-ovlon two-soan susoension bridges.

Transmission properties of frequency selective structures with air gaps

The transmission properties of compound frequency selective structures with dielectric slab and air gaps were investigated by computation and experimentation. Mechanism analyses were also carried out. Results show that the air gaps have a distinct influence on the transmission properties. Resonant frequency of the structure would increase rapidly when the air gap appears. After the gap gets larger to a specific value, generally 1/5 wavelength corresponding to the resonant frequency, the transmission properties would change periodically with the gap thickness. The change of transmission properties in one period has a close relationship with the dielectric thickness. These results provide a new method for designing a bandpass radome of large incidence angle and low loss with the concept of stealth shield radome.

Research of CBR, DM and smart algorithms based design methods for high-rise building structure form-selection

First, the high-rise building structure design process is divided into three relevant steps, that is, scheme generation and creation, performance evaluation, and scheme optimization. Then with the application of relational database, the case database of high-rise structures is constructed, the structure form-selection designing methods such as the smart algorithm based on CBR, DM, FINS, NN and GA is presented, and the original forms system of this method and its general structure are given. CBR and DM are used to generate scheme candidates; FINS and NN to evaluate and optimize the scheme performance; GA to create new structure forms. Finally, the application cases are presented, whose results fit in with the real project. It proves by combining and using the expert intelligence, algorithm intelligence and machine intelligence that this method makes good use of not only the engineering project knowledge and expertise but also much deeper knowledge contained in various engineering cases. In other words, it is because the form selection has a strong background support of vast real cases that its results prove more reliable and more acceptable. So the introduction of this method provides an effective approach to improving the quality, efficiency, automatic and smart level of high-rise structures form selection design.

A 3-D Selected Solvent Large Aperture MOF

The metal-organic framework（MOF）{[Cu（L1）_（0.5）（CN）]·4H_2O·3DMSO}_n（1） was assembled by 1,4-bis（3？,5？-dicyano-2？,6？-di（pyrid-4-yl）-1？,4？-dihydropyridyl）benzene（L1） together with copper cyanide at room temperature. In 1,the Cu~＋ ions are linked by CN-anions into a 1D helical chain,which is further fused together by tetradentate L1 ligands to build an extended 3D porous framework with two different types of functionalized channels. 1 crystallizes in the monoclinic,space group P21/c with a = 17.8729（6）,b = 8.7298（3）,c = 22.7524（9） ？,β = 96.072（4）o,V = 3530.1（2） ？~3,μ = 0.845 mm-1,Dc = 1.352 Mg/m^3,Z = 4,Mr = 718.35,F（000） = 1500,S = 1.081,the final R = 0.0877 and wR = 0.2275 for 6975 observed reflections with I 〉 2σ（I）.

Pd catalysts supported on rGO-TiO_2 composites for direct synthesis of H_2O_2: Modification of Pd^(2+)/Pd^0 ratio and hydrophilic property

The use of nanostructured composites as catalyst supports is a promising route to prepare catalysts with high selectivity and productivity. In this work, reduced graphene oxide-TiO_2(rGP-x) composites with a variation of reduced graphene oxide(rGO) content were synthesized by hydrothermal method. Pd/rGP-x catalysts were prepared in incipient-wetness impregnation method for the direct synthesis of H_2O_2 from H2 and O_2. The morphology and electronic properties of catalysts were investigated by XPS, TEM, and Raman spectroscopy.The ratio of Pd^(2+)/Pd^0 and the hydrophobicity of the catalysts were increased with the rising content of rGO. As the amount of rGO in the catalysts varied in the range of 0.025 wt%–2 wt%, the selectivity of H_2O_2 exhibited a tendency of increasing firstly and then decreasing from 0.1 wt% to 2 wt%. It indicates that good catalytic performance for H_2O_2 synthesis can be achieved only when appropriate amount of rGO is introduced. The H_2O_2 selectivity and productivity of Pd/r GP-0.025 both improved remarkably compared with Pd/P25. This enhancement originated from the combined effects of the proper ratio of Pd^(2+)/Pd^0 and hydrophobicity of the catalyst.

EFFECT OF STRUCTURE OF FUNCTIONAL POLYMER ACTIVE MATERIALS ON PROPERTIES OF GADOLINIUM ION SELECTIVE ELECTRODE

In this paper,the functional polymeric active materials were prepared by the grafting copolymerization and their structure and properties were studied.The results show that the structure and properties of these ac- tive materials have the relative large effects on the properties of gadolinium ion selective electrodes.

BP-PSO-based intelligent case retrieval method for high-rise structural form selection

Modern architectures are developing in the direction of tall buildings and complex structures,and the theoretical analysis and the design experience have seriously lagged behind the construction of super high-rise structures.Structural form selection,especially the case based reasoning (CBR) based structural form selection,is a promising tool for the construction of high-rise structures.In view of the limit of cognitive ability of domain experts,a BP (back propagation)-PSO (particle swarm optimization)-based intelligence case retrieval method for high-rise structural form selection is proposed.The CBR-based case retrieval method and the construction of the BP-PSO neutral network are introduced.And then the BP-PSO-based case retrieval method is validated by some engineering cases.The results of training and prediction indicate that the proposed method has good ability to retrieve the cases of high-rise structures.

Model Predictive Control for Vapor Compression Cycle of Refrigeration Process

A model predictive controller based on a novel structure selection criterion for the vapor compression cycle （VCC） of refrigeration process is proposed in this paper. Firstly, those system variables are analyzed which exert significant influences on the system performance. Then the structure selection criterion, a trade-off between computation complexity and model performance, is applied to different model structures, and the results are utilized to determine the optimized model structure for controller design. The controller based on multivariable model predictive control （MPC） strategy is designed, and the optimization problem for the reduced order models is formulated as a constrained minimization problem. The effectiveness of the proposed MPC controller is verified on the experimental rig.

Identification and Structure Selection for Nonlinear Stochastic Systems

A nonlinear model is proposed for effective adaptive control design. The model represents a natural way to describe input output nonlinear systems. A combined parameter off line estimation and structure detection algorithm is developed that can use an initial set of data. Then, an efficient model is obtained using orthogonal estimation with an error reduction test and other monitoring modifications. A recursive on line identification scheme is established based on the ELS algorithm to account for future time variations in the process of the parsimonious model.

Continuous selections for pseudo-lower semicontinuous set-valued mappings on convex structure spaces and hyperspace contractibility

SINCE 1956, Michael’s continuous selection theory has been applied to functional analysis,topology, approximation theory and other mathematical fields. In this letter, the concept ofthe pseudo-lower semicontinuity is introduced, and a convex structure of metric space is de-fined. A continuous selection theorem for pseudo-lower semicontinuity is given. This

Programming Supramolecular Hydrogels by Constructing a Multibranch Selection Structure

Developing chemical systems capable of executing multipath nonequilibrium processes provides valuable insights into the study of multistage dissipative structures in living systems.Here,we report a nonequilibrium multipath evolution in a three-state supramolecular system,which is clarified by associating it with a multibranch selection structure.This system is constructed by synergistically combining an assembly-induced sol-gel transition with the color change of an acid-base indicator.Depending on the initial condition and chemical fuel composition,this system can execute five distinct nonequilibrium processes.In addition,the set of structured programming can be replayed by repeatedly introducing the chemical fuel.It is further utilized to explore the applications of information encryption and establish its universality.These findings offer novel avenues for future transient material design and may make significant contributions to systems chemistry.