ANALYSES ON STRUCTURAL DAMAGE IDENTIFICATION BASED ON COMBINED PARAMETERS

The relative sensitivities of structural dynamical parameters were analyzed using a directive derivation method. The neural network is able to approximate arbitrary nonlinear mapping relationship, so it is a powerful damage identification tool for unknown systems. A neural network-based approach was presented for the structural damage detection. The combined parameters were presented as the input vector of the neural network, which computed with the change rates of the several former natural frequencies ( C), the change ratios of the frequencies ( R), and the assurance criterions of flexibilities (A). Some numerical simulation examples, such as, cantilever and truss with different damage extends and different damage locations were analyzed. The results indicate that the combined parameters are more suitable for the input patterns of neural networks than the other parameters alone.

Plugging behaviors of temporary plugging particles in hydraulic fractures

Using the visualized experimental device of temporary plugging in hydraulic fractures, the plugging behaviors of temporary plugging particles with different sizes and concentrations in hydraulic fractures were experimentally analyzed under the conditions of different carrier fluid displacements and viscosities. The results show that the greater the carrier fluid viscosity and displacement, the more difficult it is to form a plugging layer, and that the larger the size and concentration of the temporary plugging particle, the less difficult it is to form a plugging layer. When the ratio of particle size to fracture width is 0.45, the formation of the plugging layer is mainly controlled by the mass concentration of the temporary plugging particle and the viscosity of the carrier fluid, and a stable plugging layer cannot form if the mass concentration of the temporary plugging particle is less than 20 kg/m^(3)or the viscosity of the carrier fluid is greater than 3 mPa·s. When the ratio of particle size to fracture width is 0.60, the formation of the plugging layer is mainly controlled by the mass concentration of the temporary plugging particle, and a stable plugging layer cannot form if the mass concentration of the temporary plugging particle is less than 10 kg/m^(3). When the ratio of particle size to fracture width is 0.75, the formation of the plugging layer is basically not affected by other parameters, and a stable plugging layer can form within the experimental conditions. The formation process of plugging layer includes two stages and four modes. The main controlling factors affecting the formation mode are the ratio of particle size to fracture width, carrier fluid displacement and carrier fluid viscosity.

IMPROVE EFFICIENCY OF BIOGAS FEEDBACK SUPPLY CHAIN IN RURAL CHINA

Feedback supply chain is a key structure in the supply chain system, and the development of feedback supply chain for biogas biomass energy is one of the important ways of the rural ecological civilization construction. Presently, the efficiency problem of biogas supply chain in rural China has been restricting the development of biogas biomass energy business. This article, on the basis of combination of regulation parameters, describes the dynamic changes in the system, using differential equations integrated with simulation to reveal the rules of regulation parameters to investigate the efficiency problem in the biogas supply chain. First of all, on the basis of the actual situation, the flow level and flow rate system structure model and simulation equation set are established for the biogas energy feedback supply chain from a scale livestock farm to peasant households; On the basis of the differentiability of the simulation equation a third order inhomogeneous differential equation with constant coefficients containing regulative parameters is established for the quantity of biogas stored in the feedback supply chain. A theorem and its corollaries are established for the operating efficiency of supply chain to reveal the change law of the quantity of biogas, the quantity of biogas consumed daily by peasant households and its standard-reaching rate as well as other variables.

Constructing Test Suites for k-n Softw are System

In software testing,many troublesome faults are caused by interaction of input parameters. If automatic efficient test-case generator( AETG) ,in parameter order( IPO) or orthogonal Latin square is used in the software system under test,the whole test set cannot be run completely due to time or budget constraints. In this paper,according to the number of parameter k and their values n,a software system under test can be divided into four types. As for k-2 system,an algorithm was proposed to construct test cases,based on the longitudinal binary string set and method of controlling variables. As for k -n valued parameters whose n was a prime or power of prime,a method of covering array of test sets was designed to construct test sets by taking orthogonal array and derive arrays from orthogonal array and two useful conditions. As for k parameters whose n-value was not all equal,an experience algorithm was presented in this paper. The experimental results show that the size of test sets from the proposed methods is better than that from AETG,IPO,and orthogonal Latin square.

Towards combining multiple geophysical datasets to determine earthquake source parameters in China

1.Difficulties of conventional seismic studies on earthquake source parameters Earthquake source parameters,including magnitude,location,focal mechanism,rupture process are key factors for understanding seismogenic environment,mitigating seismic hazards,estimating earthquake triggering,and tectonic analysis.Traditionally,source parameters are determined by seismological methods.For example,Fang L H et al.(2014)relocated the 2012 Ms6.6 Xinjiang Xinyuan earthquake sequence using local seismograms based on the double difference method,and obtained the distribution of

Utility of combining spectral domain optical coherence tomography structural parameters for the diagnosis of early Glaucoma: a mini-review

Optical coherence tomography(OCT)has moved to the forefront of imaging modalities in the management of glaucoma and retinal diseases.It is modifying how glaucoma and glaucoma progression are diagnosed clinically and augmenting our understanding of the disease.OCT provides multiple parameters from various anatomic areas for glaucoma diagnosis,evaluation of treatment efficacy,and progression monitoring.While the use of multiple parameters has increased the likelihood of detecting early structural changes,diagnosing glaucoma in early stages is often challenging when the damages are subtle and not apparent on OCT scans,in addition to the fact that assessment of OCT parameters often yields conflicting findings.One promising approach is to combine multiple individual parameters into a composite parameter from the same test to improve diagnostic accuracy,sensitivity,and specificity.This review presents current evidence regarding the value of spectral domain OCT composite parameters in diagnosing early glaucoma.

A MODEL FOR QUANTITATIVELY ESTIMATING SHORTRANGE PRECIPITATION BASED ON GMS DIGITALIZED CLOUD MAPS-PART Ⅰ:ANALYSIS OF QUANTITATIVE CLOUD-PRECIPITATION RELATIONS AND MODEL DESIGN

Some typical samples are used to explore the quantitative correlation with their features between a convective cloud and its rainfall field,with which to develop two morphological functions for the correlation and by singling out their most suitable groups of parameters we propose a model for quantitatively estimating precipitation in the context o{ the in-advance recognition of meso-α convective system properties and its precipitating center.From the model fitting precision and forecasting accuracy we find that it is feasible to utilize geostationary meteorological satellite (GMS) digitalized imagery for estimating short-term rainfall in a quantitative manner.Also,evidence suggests that the model is supposed to be restricted in its applicability due to the fact that the employed samples are from rather typical rainfall events that are large-scale,slow-moving and have well-defined genesis and dissipative stages.