Advanced Materials Research Vol. 461

Abstract: In this paper, the additive-multiplicative hazards model with gap time data of recurrent events is studied. Based on this model, two cases are discussed, i.e., the observed data are gap time of recurrent event, and the observed data are a group recurrent events recurrence one time, and the parametric and nonparametric estimations are given. Then the efficiency of estimators for these two cases is compared.

Abstract: In the complex control processes of the industrial boiler combustion system with non-linear, time-varying and multivariable, aim at the original control parameters fixed, slow response, delay regulation and other problems, this paper introduces a control method that combines ant colony algorithm with fuzzy PID control, improves the design of fuzzy control rules table and optimizes the PID control parameters. Simulation results show that this control scheme is superior to conventional PID control and fuzzy PID control.

Abstract: The Nd(III) extraction kinetics by 2-ethylhexylphosphonic acid mono-(2-ethylhexyl) ester (HEH/EHP) in the presence of a complexing agent acetic acid(HAc) has been investigated using constant interfacial cell. The kinetics mechanism and extraction rate equation were achieved by the studies on the effect of stirring rate, temperature and specific interfacial area on the rate of extraction. The effect of temperature on the kinetics was analyzed, the value of the apparent activation energy was calculated as 9.24 kJ/mol, and it was found that the extraction process was a diffusion-controlled kinetics process.

Abstract: Directional drilling technology is an important and very promising trenchless pipeline crossing technology. On the basis of the related literature research at home and abroad and our pipeline construction site investigation, focuses on several common soil properties are introduced, and then the formation adaptability of directional drilling is analyzed. The drilling selection methods are made when drilling in the specific geological conditions, and the possible risks of the construction process have been classified in the directional drilling.

Abstract: In t In this article, we introduce a sort of vector-valued wavelet wraps with multi-scale dilation of space L ²(Rⁿ, C^v) , which are generaliza-tions of multivariaale wavelet wraps. A method for designing a sort of biorthogonal vector-valued wavelet wraps is presented and their biorthogonality property is characterized by virtue of time-frequency analysis method, matrix theory, and operator theory. Three biorthogonality formulas regarding these wavelet packets are established. Furtherore, it is shown how to obtain new Riesz bases of space L ²(Rⁿ, C^v) from these wavelet wraps.

Abstract: The forming compact process of the concrete brick in vibration is simulated based on three-dimensional discrete element method (3D-DEM) where the crude granular materials of the concrete brick are simplified into two spherical particles of different sizes. There are three zones affecting compactness in vibration including porous zone, compact zone, and compact stable zone. The compactness's variation of the different heights and the above three zone are analyzed when both the amplitude and the frequency are different. By orthogonal experiment the result is showed that the average compactness is best when the amplitude is about 4 mm and the frequency is 100 Hz.

Abstract: Wavelet analysishas been a powerful tool for exploring and solving many complicated problems in natural science and enginee-ring computation. In this work, the notion of orthogonal matrix-valued trivariate small-wave wraps and wavelet frame wraps, which are generalization of univariate small-wave wraps, is introduced. A new procedure for constructing these vector trivariate small-wave wraps is presented. Their characteristics are studied by using time-frequency analysis method, Banach space theory and finite group theory. Orthogonal formulas concerning the wavelet packs are established. The biorthogonality formulas concerning these wavelet wraps are established. Moreover, it is shown how to draw new Riesz bases of space from these wavelet wraps.

Abstract: Map building is an essential problem in the field of mobile robot research. The accurate environmental map provides the important safeguard for the robot autonomous navigation and localization. In this paper, the two-dimensional environment map based on geometric features information was built by laser data when service robot worked in indoor structured environment. However, this article focused on analyzing the method of line fitting in the process of building local map and the method of global map updating. The experiment indicated that this method has the high accuracy and effectiveness, also reduces error caused by the uncertain information in the process of map building, which makes the indoor environment map update in real time.

Abstract: According to the uneven illumination or the very complex background cases, global threshold value method can't correctly to binary particle image; this paper puts forward a kind of background correction method and the OTSU for particle image binary method. It's used background correction method to eliminate the influence of uneven illumination, and the OTSU for binary particle image. Combining with the above methods are tested, and the result shows that, after the background is corrected, we segment the background brightness particle image; the OTSU can obtain ideal image segmentation effect.

Abstract: Abstract: Concrete members strengthened by fiber reinforced polymer (FRP) are increasingly becoming a popular retrofit technique in recent years due to the excellent material properties, convenient and easy construction methods, and outstanding strengthening effect. However, fundamental researches are incomplete; especially the characteristics research of square cross-section of FRP confined concrete has become a major obstacle for the development of further research and application. Therefore, the better understanding of the behavior of confined concrete becomes of paramount importance. A total of 10 concrete columns, which were reinforced with CFRP (carbon fiber reinforced polymer) and with filleted square sections, were fabricated and tested subjected to axial load to investigate the mechanical properties of FRP confined concrete. The mechanical behavior of FRP confined concrete has been further understood and some useful conclusions are obtained.