We present an algorithm for the integrand-level reduction of multi-loop amplitudes of renormalizable field theories, based on computational algebraic geometry. This algorithm uses (1) the Grobner basis method to determine the basis for integrand-level reduction, (2) the primary decomposition of an ideal to classify all inequivalent solutions of unitarity cuts. The resulting basis and cut solutions can be used to reconstruct the integrand from unitarity cuts, via polynomial fitting techniques. The basis determination part of the algorithm has been implemented in the Mathematica package, BasisDet. The primary decomposition part can be readily carried out by algebraic geometry softwares, with the output of the package BasisDet. The algorithm works in both D = 4 and D = 4 - 2 epsilon dimensions, and we present some two and three-loop examples of applications of this algorithm.
Micro capacitive switches and methods of manufacturing micro capacitive switches at variable nominal capacitance value using micro-structures on the contact plates of the same dimension. In a preferred embodiment, a separately manufactured contact plate can be mounted to a movable magnet in order to be actuated to “on” and “off” state of the capacitive switch. Depending on the contact plate's surface condition, variable contact capacitance at “on” state can be precisely specified by geometrical properties of the micro-structures on the surface, such as the density, size and depth.
Method, apparatus, and system for encoding and decoding signals are disclosed. The encoding method includes: converting a first-domain signal into a second-domain signal; performing Linear Prediction (LP) processing and Long-Term Prediction (LTP) processing for the second-domain signal; obtaining a long-term flag according to a decision criterion; obtaining a second-domain predictive signal according to the LP processing result and the LTP processing result when the long-term flag is a first flag; or obtaining a second-domain predictive signal according to the LP processing result when the long-term flag is a second flag; converting the second-domain predictive signal into a first-domain predictive signal, calculating a first-domain predictive residual signal; and outputting a bit stream that includes the first-domain predictive residual signal. Subsequent encoding or decoding process is performed adaptively according to the long-term flag; and it is not always necessary to consider the LTP processing result, thus improving the compression performance of codec.
Multi-channel combustion data, consisting of gas pressure and two combustion chamber luminosity measurements, are investigated in the prediction of combustion instability. Wavelet analysis is used for feature extraction. A SVM approach is applied for novelty detection and the construction of a model of normal system operation. Novelty scores generated by classifiers from different channels are combined to give a final decision of data novelty. Comparisons between the proposed SVM method and a GMM approach show that earlier identification of combustion instability, and greater distinction between stable and unstable data classes, are achieved with the proposed SVM approach.
The brazing of 55% SiC_p/A356 (volume fraction) composites in air using Zn-Al alloy as a filler metal was investigated. During the brazing process, ultrasonic vibrations were applied to samples for bonding and a significant dissolution of the filler metal into the matrix alloy in the base materials occurred. As brazing temperatures were increased, the thickness of the partial melting layers in the base material increased. SiC particles in the partial melting layer of the base material were transferred into the liquid filler under ultrasonic action and a bond with homogeneously distributed reinforcements was obtained after solidification. The volume fraction of SiC particles in the bonds could be varied by changing the brazing temperature. The maximum SiC particle volume fraction of the bond material reached 37% at a brazing temperature of 500 ℃. The shear strength of the brazed bonds was improved at pressures up to 244 MPa (at 20 ℃) and increased by 133.8% (at 200 ℃) compared with the filler of the Zn-based alloy.
Yang Zhang
Bo Yang
Junwang Meng
Shaokai Gao
Xinyu Dong
Jinian Shu
The reactions of gas-phase phenanthrene and suspended phenanthrene particles with ozone were conducted in a 2001 chamber. The secondary organic aerosol formation was observed in the reaction of gas-phase phenanthrene with ozone and simultaneously the size distribution of the secondary organic aerosol was monitored with a scanning mobility particle sizer during the formation process. The particulate ozonation products from both reactions were analyzed with a vacuum ultraviolet photoionization aerosol time-of-flight mass spectrometer. 2,2'-Diformylbiphenyl was identified as the dominant product in both homogeneous and heterogeneous reactions of phenanthrene with ozone. GC/MS analysis of ozonation products of Phenanthrene in glacial acetic acid was carried out for assigning time-of-flight mass spectra of reaction products formed in the homogeneous and heterogeneous reactions of phenanthrene with ozone. (C) 2009 Elsevier Ltd. All rights reserved.
In this paper, a comprehensive corporate reputation measurement and explanation model suggested by Schwaiger was briefly introduced in the first part. Since the model s applicability in China has been proved in former work, using structural equation modeling (SEM) and partial least squares (PLS) statistical methods and taking advantage of first-hand data, the impact of corporate reputation on customer loyalty was empirically studied in the second part of this paper. Statistical results indicate that the affective component (Likeability) of corporate reputation exerts greater and more significant influence on the establishment of customer loyalty than the cognitive component (competency) does. Furthermore, performance and corporate social responsibility (CSR) were identified to be the most two important drivers in influencing corporate reputation and also in driving customer loyalty.
Yang Zhang
Bixia Lin
Zhuxi Fu
Cihui Liu and Wei Han
Nanocrystalline ZnO thin films on p-type Si(1 0 0) substrates have been prepared by a sol-gel method. X-ray diffraction results showed polycrystalline wurtzite with a preferential (0 0 2) orientation. Morphology studies revealed that the films consisted of uniform grains in size of 33 nm. A strong ultraviolet emission with no distinct visible emissions was observed in room temperature photoluminescence spectrum. The ultraviolet emission results from the recombination of free exciton with stronger longitudinal optical (LO) phonon replica. Stronger LO phonon replica may be ascribed to the strong interaction between the exciton and LO phonon in nanostructure. Nanostructure of films is also responsible for the blueshift of free exciton emission compared with single-crystal ZnO. The absence of E1 (LO) mode in Raman spectrum further confirmed low defect density in as-grown nanocrystalline ZnO films. The electrical junction properties characterized by current–voltage measurement showed a rectifying behavior.
The present invention relates to the field of selective metallization, and in particular to preparing a polymer article for selective metallization by submerging the article in a first liquid, and while submerged irradiate the article by a laser beam the area of the article on which the metal is to be deposited. An activation step, prior to the selective metallization, comprises submerging the article in an activation liquid for depositing seed particles in the selected area. The irradiation of the selected area is proportionate so as to cause a temporary melting of the polymer in the surface of the selected area of the polymer article. The invention is advantageous in that the preparation may be performed with a relatively high scan rate across the polymer article, and in that a quite limited use of toxic chemicals.
Yang Zhang
Xiang Li
Katrin Anne Becker
Erich Gulbins
Membrane lipids seem to be organized and not randomly distributed in the cell membrane. In particular, sphingolipids seem to interact with cholesterol in the outer leaflet of the cell membrane resulting in the formation of distinct membrane domains, i.e. rafts. The generation of ceramide within rafts alters their biophysical properties and results in the formation of large ceramide-enriched membrane platforms. These platforms serve to cluster receptor molecules and to organize intracellular signalling molecules to facilitate signal transduction via a receptor upon stimulation. Thus, ceramide-enriched membrane domains amplify not only receptor-, but also stress-mediated signalling events. Although many receptors cluster, the molecular mechanisms mediating this important and general event in signal transduction need to be identified.
Systems and methods are presented for providing resources by way of a platform as a service in a distributed computing environment to perform a job. Resources of the system, job performing on the system, and schedulers of the jobs performing on the system are decoupled in a manner that allows a job to easily migrate among resources. It is contemplated that the migration of jobs from a first pool of resource to a second pool of resource is performed by the system without human intervention. The migration of a job may utilize different schedulers for the different resources. Further, it is contemplated that a pool of resources may automatically allocate additional or fewer resources in response to a migration of a job.
We report what we believe to be the first comparative study of multi-objective genetic programming (GP) algorithms on benchmark symbolic regression and machine learning problems. We compare the Strength Pareto Evolutionary Algorithm (SPEA2), the Non-dominated Sorting Genetic Algorithm (NSGA-II) and the Pareto Converging Genetic Algorithm (PCGA) evolutionary paradigms. As well as comparing the quality of the final solutions, we also examine the speed of convergence of the three evolutionary algorithms. Based on our observations, the SPEA2-based algorithm appears to have problems controlling tree bloat-that is, the uncontrolled growth in the size of the chromosomal tree structures. The NSGA-II-based algorithm on the other hand seems to experience difficulties in locating low error solutions. Overall, the PCGA-based algorithm gives solutions with the lowest errors and the lowest mean complexity.