INITIAL-OBLIQUE DERIVATIVE PROBLEMS FOR NONLINEAR PARABOLIC SYSTEMS WITH MEASURABLE COEFFICIENTS

This paper deals with some initial-oblique derivative boundary value problems for nonlinear nondivergent parabolic systems of several second order equations with measurable coefficients in multiply connected domains. Firstly, a priori estimates of solutions for the initial-boundary value problems are given, and then by using the above estimates of solutions and the Leray-Schauder theorem, the existence and uniqueness of solutions for the problems are proved.

The Approach of Compensation of Air Refractive Index in Thermal Expansion Coefficients Measurement Based on Laser Feedback Interferometry

We present the thermal expansion coefficient （TEC） measurement technology of compensating for the effect of variations in the refractive index based on a Nd： YA G laser feedback system, the beam frequency is shifted by a pair of aeousto-optic modulators and then the heterodyne phase measurement technique is used. The sample measured is placed in a muffle furnace with two coaxial holes opened on the opposite furnace walls. The measurement beams hit perpendicularly and coaxially on each surface of the sample. The reference beams hit on the reference mirror and the high-refiectivity mirror, respectively. By the heterodyne configuration and computing, the influences of the vibration, distortion of the sample supporter and the effect of variations in the refractive index are measured and largely minimized. For validation, the TECs of aluminum samples are determined in the temperature range of 29-748K, confirming not only the precision within 5 × 10-7 K-1 and the accuracy within 0.4% from 298K to 448K but also the high sensitivity non-contact measurement of the lower reflectivity surface induced by the sample oxidization from 448 K to 748 K.

The Correlation Coefficient of Hesitancy Fuzzy Graphs in Decision Making

The hesitancy fuzzy graphs(HFGs),an extension of fuzzy graphs,are useful tools for dealing with ambiguity and uncertainty in issues involving decision-making(DM).This research implements a correlation coefficient measure(CCM)to assess the strength of the association between HFGs in this article since CCMs have a high capacity to process and interpret data.The CCM that is proposed between the HFGs has better qualities than the existing ones.It lowers restrictions on the hesitant fuzzy elements’length and may be used to establish whether the HFGs are connected negatively or favorably.Additionally,a CCMbased attribute DM approach is built into a hesitant fuzzy environment.This article suggests the use of weighted correlation coefficient measures(WCCMs)using the CCM concept to quantify the correlation between two HFGs.The decisionmaking problems of hesitancy fuzzy preference relations(HFPRs)are considered.This research proposes a new technique for assessing the relative weights of experts based on the uncertainty of HFPRs and the correlation coefficient degree of each HFPR.This paper determines the ranking order of all alternatives and the best one by using the CCMs between each option and the ideal choice.In the meantime,the appropriate example is given to demonstrate the viability of the new strategies.

Parallelized Jaccard-Based Learning Method and MapReduce Implementation for Mobile Devices Recognition from Massive Network Data

The ability of accurate and scalable mobile device recognition is critically important for mobile network operators and ISPs to understand their customers' behaviours and enhance their user experience.In this paper,we propose a novel method for mobile device model recognition by using statistical information derived from large amounts of mobile network traffic data.Specifically,we create a Jaccardbased coefficient measure method to identify a proper keyword representing each mobile device model from massive unstructured textual HTTP access logs.To handle the large amount of traffic data generated from large mobile networks,this method is designed as a set of parallel algorithms,and is implemented through the MapReduce framework which is a distributed parallel programming model with proven low-cost and high-efficiency features.Evaluations using real data sets show that our method can accurately recognise mobile client models while meeting the scalability and producer-independency requirements of large mobile network operators.Results show that a 91.5% accuracy rate is achieved for recognising mobile client models from 2 billion records,which is dramatically higher than existing solutions.

Characteristics of K_d (490) around Nansha Islands in the South China Sea

The diffusion attenuation coefficient for downwelling irradiance, Kd (490), is an important optical parameter of seawater. The optical property, Kd (490), around Nansha Islands in the South China Sea was analyzed based on optical data profiles measured with SPMR ( SeaWiFS Profiling Multichannel Radiometer ) and SMSR ( SeaWiFS Multichannel Surface Reference ) instrument in April and May, 1999. The results show that Kd (490) is closely correlated with chlorophyll-a concentration, Cchl.a, and that the vertical distribution of Kd (490) shows the strong stratification of the water column in this area. Kd (490) has a similar vertical co-variation as KL (490), the diffusive attenuation coefficient for upwelling radiance. Both coefficients increase with depth in the upper layer, where KL (490) is greater than Kd (490); and after a depth, approximatively at the chlorophyll maximum, they decrease with depth, with the former being smaller than the latter.

A convenient method for measuring gas-liquid volumetric mass transfer coefficient in micro reactors

The research on gas-liquid multiphase reactions using micro reactors is becoming increasingly widespread, given their excellent mass transfer performance. Establishing an accurate and reliable method to measure the gas-liquid mass transfer performance of micro reactors is crucial for evaluating and optimizing the design of micro reactor structure. In this paper, the physical absorption method of aqueous solution-CO_(2) and the chemical absorption method of sodium carbonate solution-CO_(2) were proposed. By analyzing the chemical reaction equilibrium during the absorption process, the relationship between the mass transfer of CO_(2) and the solubility of hydroxide ions in the solution was established, and the total gas-liquid mass transfer coefficient was immediately obtained by measuring the p H value. The corresponding testing platform and process have been established based on the characteristics of the proposed method to ensure fast and accurate measurement. In addition, the chemical absorption method takes into account temperature factors that were not previously considered. The volumetric mass transfer coefficient measured by these two methods is in the same range as those measured by other methods using the same microchannel structure in previous literature. The methods have the advantages of low equipment cost, faster measurement speed, and simpler procedures, which can facilitate its wide application to the evaluation of the mass transfer performance and hence can guide the structure optimization of microchannel reactors.

A technique of reconstructing field for measuring sound reflection coefficients at arbitrary angles of incidence

An improved reconstructing field method for measuring sound reflection coefficient of a large impedance surface at arbitrary incident angles is proposed in this paper. In order to get the reflection coefficient by the Spatial Transformation of Sound Fields (STSF), the complex pressure on two parallel planes near by the material surface or the reflection surface must be measured. By the acoustic intensity measurement, the phases of complex pressure on two parallel planes are given. The results of the numerical simulations are shown that the error due to the finite size of the measurement area, and it may be reduced by using a dipole sound source.

Gradient Estimates for Parabolic Equations in Generalized Weighted Morrey Spaces

We consider the Cauchy-Dirichlet problem for linear divergence form parabolic operators in bounded Reifenberg flat domain. The coefficients supposed to be only measurable in one of the space variables and small BMO with respect to the others. We obtain Calderon-Zygmund type estimate for the gradient of the solution in generalized weighted Morrey spaces with Muckenhoupt weight.

MEASUREMENTS OF THE ABSORPTION COEFFICIENT OF ATMOSPHERIC AEROSOLS

This paper discusses the measurement of the absorption coefficient of atmospheric aerosols and its meas- uring system based on the principle of integrating plate. Measurements in Beijing show that the absorption coefficient of atmospheric aerosols in the heating period varies in a range of 10to 10mand in the non-heating period, its values are near 10m.

A study of ion exchange selectivity coefficient by cyclic voltammetric measurement

An equation to express ion exchange selectivity coefficient was derived and used for cal- culating that of PPY film with the results obtained by cyclic voltamrnetric measurement.PPY film was synthesized by electrochemical method in aqueous solution using K_4Fc(CN)_6 as supporting electrolyte, and the anions were doped into the film.Ion exchange behaviour of doped Fe(CN)_6^(3-/4-)in the PPY film with Cl^-,NO_3^- or F^- ions in solution has been studied,and the corresponding ion exchange selec- tivity coefficients were determined.