Superposition Of Processes Research Articles

Generation of various vector beams based on vector superposition of two orthogonal linearly polarized TEM01 beams

We both theoretically and experimentally demonstrated the generation of various vector beams (VBs) by vector superposition of two orthogonal linearly polarized TEM01 beams. The theoretical analysis indicates that VBs with diverse polarization distributions can be synthesized through changing the mode directions or polarization directions of the two TEM01 beams and the phase difference between them. The polarization states of the synthesized VBs for each phase-difference value span a closed circle on the surface of the Poincare sphere, Σ. The center of the circle coincides with the center of Σ, and the circle plane is perpendicular to the S2OS3 plane. Experimentally, an interferometric arrangement was employed to realize such a superposition process by using two discontinuous phase plates and a voltage-uploaded electro-optical phase-modulator. Various generalized cylindrical VBs and hybrid VBs were produced in our experiments with the same configuration.

Ultra-Precision Fly Cutting Experimental Study of Semiconductor Laser Heat Sink

Laser cooling is one of the critical problems in the research of high power semiconductor lasers. This paper provides an overview of microchannel heat sink which is used to cool the high power semiconductor lasers. The method of polishing after cutting is the current processing method of the heat sink, which is because the ordinary cutting method cannot meet the requirements of high quality of surface and edge burrs. This paper proposes ultra-precision fly cutting method for heat sink machining to omit the polishing processing to improve the machining efficiency, and verifies by experiments that the feasibility of the processing method and the edge quality improved by workpiece superposition processing method.

激光能量叠加过程中对准精度对焦斑的影响

激光能量叠加过程中对准精度对焦斑的影响

Force Sensitive Property of Same-Base Quartz Crystal Resonator and Signal Amalgamation

According to the stress distribution in the thin round-shaped quartz plate with radial force, multiple resonators are designed in the different positions on same quartz crystal wafer. The force sensitive property of the resonators in different positions is studied. The research result shows, the force sensitive property of the resonator is closely related to the locations and the adding force azimuth; the force sensitive property of the resonators in different positions have a significant difference. If making difference frequency process of the resonant frequencies which is produced by the resonators, the interfering factors of the temperature etc. can be inhibited; if making superposition and integration process of the resonators’ force sensitive property, the total force sensitive property of the resonator with the multiple-electrode structure can be improved.

Crystal-morphology and Evolution of Snow Cover: Empirical Modeling on the Base of Symmetry Theory

Snow cover is represented as a natural community of the shapes of growing crystals interacting with each other and exposed to environmental influences. It is worked out the empirical deterministic models describing the sublimation-metamorphic cycle of seasonal snow cover and the polymorphic variants of this cycle. The main driving force of processes yielding an evolutionary row of crystals are internal interactions within a snow pack. For all that the factor of time (the age of genetic player) plays a crucial role in sublimation metamorphism. Stadiality of the forms of crystal growth and self-development snow layers are revealed. They are a result of successive process of superposition of ice crystal-chemical symmetry and dissymmetry of the whole system soil–snow–atmosphere, according to the known P. Curie principle. Crystal-morphological classification for season snow is worked out by author on the base of the given an account evolutionary model. Two categories of crystal shapes have been picked out: classes and types of forms. The first category reflects the invariant aspect of snow sublimation metamorphism and the second one – the hydrothermal conditions of this process in each layer of the snow pack. Evolution of snow pack structure is conditioned to a marked degree by probabilistic conformity to natural laws, manifesting themselves in the processes of auto-regulation of metamorphism. These processes include the two types of regulation: the self-regulation of snow layers, on the one hand, and their regulation from outside – under the influence of atmospheric perturbations, on the other hand. An analysis of the processes of auto-regulation of metamorphism is capable of rendering a substantial service in the development of methods of short- and long-term forecasting of the avalanches. Crystal-morphological structure of snow cover may be considered also as a “quickly running” model of many evolutionary biosphere processes.

Spectral Radiation Drift of LEDs Under Step-Mode Operation and Its Effect on the Measurement of the Non-Linearity of Radiation Thermometers

The non-linearity (NL) of radiation thermometers is critically involved when realizing ITS-90 above the silver point. It has to be corrected for, and its uncertainty should be adequately specified. In this article, results are presented of NL measurements based upon the superposition method and involving light emitting diodes (LEDs) with high radiance output, peaked at a wavelength of 645 nm. To this end, the two LEDs in question have been operated in the pulse mode with a fixed phase shift. Their spectral radiances have been measured by the radiation thermometers to be tested, separately or superimposed by means of a beam splitter. Still the drift in the spectral radiance observed after switching on the LEDs has to be taken into account and corrected for, since this drift, interfering during the superposition procedure, could corrupt the sum rule for the fluxes involved, which is the crux of the superposition method. Therefore, experimental research has been carried out to characterize the drift of LEDs operated in the pulse mode with a fixed phase shift. The result indicated that the drift could be roughly specified in terms of characteristic time intervals: non-linear drift in the first tens of seconds followed by a quasi-linear drift in the subsequent time interval. The crossover time from non-linear to quasi-linear drift could be ascertained by experiment. In the course of the superposition process, switching of the LEDs was done in such a way that only the quasi-linear part of the drift was involved which allowed for the correction of the drift in the NL measurements, as will be reported. Two radiation thermometers were involved in the NL measurements at radiance temperatures between the silver point and 3153 K: an LP-4, with a central wavelength of 650 nm and 10 nm bandwidth, manufactured by KE-Technologie and the primary standard pyrometer PSP, with a central wavelength of 660 nm and 10 nm bandwidth, developed by NIM.

SU‐E‐I‐103: Tissue Dependent Deformation Field Regularization through Collapsed Cone Convolution/Superposition

Purpose Previous Tissue‐dependent deformation field filters incur a relatively high computation cost. We present a collapsed‐cone based adaptive filtering method to reduce the computational overhead. Our proposed method is able to reduce the computational complexity of the superposition process from O(q3N3) to O(MN3) time, where q is the chosen neighborhood size, N is the volume dimension and M is the number of kernel axes. Method and Materials Our proposed filter performs diffusion along chosen kernel axes instead of within a size‐limited cubic neighborhood. During the ray tracing process along the kernel axis, the contribution of a given voxel to its neighbors is exponentially attenuated to simulate the physical characteristics of tissues. During the attenuation, local biomedical information can be naturally incorporated by scaling the ray tracing length according to the underlying tissue stiffness. This scaling makes a voxel within soft tissues more “malleable” with respect to its neighborsˈ movements. Results: We integrated different regularization methods into the same deformable registration approach (Demons algorithm). The kernel size of the Gaussian filter was set to be 5; the number of kernel directions for the CC filter were 4 in 2D and 16 in 3D. The experiments shows that our results produces are no‐worse result with a faster speed than these from other techniques. By investigating the finer details, the proposed method shows better capability of tracking changes. Conclusion Wpresented a collapsed‐cone (CC) based technique for the regularization of the deformation fields in image registration, which provides realistic deformation field and is useful for studying and modeling organs in motion. Since the CC filter can cover the entire 3D volume of interest, a better maintenance of the overall object shapes can be achieved. The incorporation of tissue information allows the CC filter to adjust its behavior to match the tissue biomedical characteristics.

A Nonnegative Blind Source Separation Model for Binary Test Data

A novel method called binNMF is introduced which aimed to extract hidden information from multivariate binary data sets. The method treats the problem in the spirit of blind source separation: The data are assumed to be generated by a superposition of several simultaneously acting sources or elementary causes which are not observable directly. The superposition process is based on a minimum of assumptions and reversed to identify the underlying sources. The method is motivated, developed, and demonstrated in the context of binary wafer test data which evolve during microchip fabrication.

Identificación mediante estudio comparativo de radiografías craneales ante mórtem y post mórtem

In this paper we are presenting a case in which the only available tool for setting out identification was matching two pairs of ante-mortem and post-mortem cranium radiographies.In collaboration with international Police Brigades, the body was taken to the Forensic Anthropology Unit of the Forensic Pathology Department of the Catalan Institute of Legal Medicine (IMLC) for morphological and radiological study.There were two ante-mortem radiographies: one of them in lateral projection and the other one in nose-chin projection. The frontal radiography presented an unusual projection (nose and chin), focused on the study of the maxillas sinuses which were full (sinusitis).In this case, post-mortem radiographies were performed. Several radiological projections of the skull: forehead and side, base (Hirtz projection), nose-chin plate (Waters projection) to visualize the frontal sinuses. In the comparative study of the frontal sinuses the methods used by Delclós in his anthropometric studies were also implemented. It was compared the ante-mortem and post-mortem radiographies images using a process of superposition of the images.Anyway, the lack of remarkable dissimilarities between the ante-mortem and post-mortem radiographies made the identification possible.

Analysis of Symmetrically Laminated Folded Plate Structures Using the Meshfree Galerkin Method

A meshfree Galerkin method that is based on the first-order shear deformation theory (FSDT) is developed in this paper to study the flexure behavior of folded symmetrically laminated plate structures. The mature meshfree model that was established by the authors for the stability analysis of folded isotropic plate structures is extended to simulate folded laminated plate structures. The feature of this model is its consideration of a folded laminated plate as an assembly of laminates and its ability to study the laminates separately with the meshfree Galerkin method before the entire folded plate. The stiffness matrices of the laminates are first derived by the meshfree method. They are then superposed to produce the global stiffness matrix of the folded plate. The superposition process is realized by treating every laminate as a super element and accumulating their stiffness matrices one by one as in the finite element methods (FEM). By taking advantage of the meshfree characteristics, no mesh is required to determine the stiffness matrices of the laminates in this paper. Hence the troublesome remeshing is removed completely from the study of such problems as the large deformation or crack propagation of folded laminated plates. The convergence and accuracy of the proposed method are examined by computing several numerical examples, and good agreement is observed between the present results and those that are given by ANSYS.

Color image segmentation using morphological clustering and fusion with automatic scale selection

In this paper, a color image segmentation method considering pairwise color projections is proposed. Each pairwise projection is analyzed according to an unsupervised morphological clustering which looks for the dominant colors of a 2D histogram. This leads to obtaining three segmentation maps combined by superposition after being simplified. The superposition process itself producing an over-segmentation of the image, a pairwise region merging is performed according to a similarity criterion up to a termination criterion. To fully automate the segmentation, an energy function is proposed to quantify the segmentation quality. The latter acts as a performance indicator and is used all over the segmentation to tune its parameters: the scale of the unsupervised morphological clustering and the termination criterion of region merging. Experimental results are conducted on a reference image database and comparisons with state-of-the-art algorithms.

Decomposition and recovery on MA superposition process using ICA

Decomposition and recovery on Moving Average(MA)superposition process contained in multivariable time series were researched in this paper.Firstly,because of the independence of the high-order statistical information,the mixtures were separated by searching a reversible matrix with the Independent Component Analysis(ICA)algorithm-fixed point algorithm.Then an adaptive method was designed to identify MA model based on higher-order cumulant.In every iteration,it estimated the order and the parameters of MA.Finally,the effectiveness of the algorithm was verified by the computer simulation.

Approximating Multiple Arrival Streams by Using Aggregation

In this paper we consider the superposition of independent Coxian arrival streams. We propose a method to efficiently approximate the superposition process, based on state space aggregation. The method is applied to a single server queue and to an inventory control model. Simulation results show that the method accurately estimates performance characteristics and that it significantly outperforms two-moment approximations.

Phylogenetic and ontogenetic parallelisms on talo-calcaneal superposition

The process of talo-calcaneal superposition is one of the most important steps in the transformation of the reptilian foot (primitive) into the mammalian foot (modern). This change was developed in certain families of mammal-like reptiles and transitional mammals during the Mesozoic age and represents a different path in the morphological development of the foot to that of other dominant reptiles (Dinosaurs, etc.). The talo-calcaneal superposition takes place during the embryonic stage of human life and ends during the primary stages of the foetal period of the same. This study aims to demonstrate the similarities between the phylogenic and ontogenic development of the said morphological change.

The development of a dynamic amplification estimator for bridges with good road profiles

The paper considers the influence of the surface profile on the dynamic amplification of a simply supported bridge when subject to a quarter-car vehicle model. The effect of the profile irregularities on the bridge dynamic amplification is characterized with a ‘response surface’ giving dynamic amplification due to a ‘unit ramp’ at any location. Even though the dynamic interaction problem is nonlinear, the effects of all ramps which together make up a road profile can be calculated separately and added using the ‘response surface’. This superposition process achieves reasonable accuracy for ‘good’ (moderately smooth) surface profiles. An accurate estimate of dynamic amplification for bridges is demonstrated with a wide range of good profiles.

APPLICATION OF AN ALTERNATING METHOD TO THE THERMOELASTIC PROBLEMS WITH MULTIPLE CIRCULAR HOLES IN AN INFINITE DOMAIN

This paper presents a new efficient procedure to analyze the thermoelastic problems with multiple circular holes in two-dimensional infinite domain using an alternating method. To achieve this purpose, the analytical solutions including the temperature and associated thermal stress for the arbitrary heat flux across the single circular hole boundary in an infinite domain are first derived. Both the temperature and thermal stress fields in the thermal problems are simultaneously solved by these analytical solutions with the successive iterative superposition process. Compared with the solution of the conventional finite-element technique, the present method has been more accurate and has more advantages. Effects of the distributions and sizes of the holes on the stress concentration in the thermal problems also are evaluated in detail herein.

Use of pin-jointed structures in teaching frame analysis

In the flexibility-based method of frame analysis described in this paper, the principle of superposition is used to combine (a) the effect of applied loads and actions with the unknown end moments equated to zero and (b) the effect of the unknown end moments in an otherwise unloaded structure. The first stage of this superposition process, in which the unknown end moments are equated to zero, corresponds to a pin-jointed structure in which loads and actions are applied to simply supported elements. This pin-jointed structure is demonstrated in this paper to provide a simple and consistent model for teaching independent modes of sway and the associated compatibility expressions relating sway translations to element sway rotations and joint translations. It also simplifies derivation of the sway equilibrium equations and consideration of the effects of temperature and settlement. More importantly it provides a useful basis for sketching bending moment diagrams and deflected shapes. As the pin-jointed structure represents a compatible set of virtual displacements it may also be applied to similar processes in stiffness-based methods of analysis. This helpful teaching model is illustrated using examples of a continuous beam and a pair of sway frames.

Superposition of Power-Law Models for Hardware/Software System Reliability Data Analysis

One of the widely used NHPP models in reliability is the so-called power-law model, also known as the Duane model. A power-law model can be applied in analyzing failure data of both software and hardware systems. Nevertheless, the power-law model is no longer applicable to describe the failure behavior when a hardware/software embedded system is concerned since the failures can come from both hardware and software. How to analyze the failure data of this type is still a problem to study and a new type of model is needed to develop. In this paper, we consider the superposition of the power-law models (SPLM) as one candidate to describe the failure behaviors of hardware/software systems. The characteristics of SPLMs are thoroughly studied. It is shown that an SPLM has the intensity function that can be increasing, decreasing, increasing-then-decreasing or decreasing-then-increasing. Specifically, the identification method of the superposition of power-law processes is provided by using the TTT-plot technique. The TTT-transform of a superposition of power-law processes is DFR-like. Therefore, the conditional TTT-plot should present a convex pattern if the system failures follow a superposition process by a few power-law processes. This provides us an easy way to identify the model when the testing data is available.

Long‐term mechanical and viscoelastic behavior of constitutive polymeric materials used for magnetic tapes

AbstractCreep‐compliance behavior of specially prepared magnetic tape materials was measured at elevated temperature levels to facilitate the use of a time–temperature superposition (TTS) process. This TTS process allowed for the construction of master curves at a reference temperature of 30°C, which were used to predict the long‐term viscoelastic behavior of the magnetic particle (MP) and metal‐evaporated (ME) tapes used in the study. The specially prepared samples allowed for the use of a rule of mixtures technique to determine the long‐term creep compliance of the front coat and back coat used for the magnetic tapes. To test the validity of this procedure, the front coat, substrate, and back coat data determined through separate experiments were used to calculate creep compliances of simulated tapes. These calculated creep‐compliance curves were then compared to measured data for the actual magnetic tapes. After determination and validation of the front coat, substrate, and back coat creep‐compliance data sets, they were used to determine strain distributions when the tapes are stored in a reel. Strain distributions were calculated for two cases, which reflect how tapes are stored in different drives: (1) the front coat (magnetic + nonmagnetic layer) is oriented away from the hub, and (2) the front coat is oriented toward the hub. Results showed that strain in the critical front coat of a tape is lower if it is stored with the front coat oriented toward the hub. In addition, the use of the creep‐compliance data showed that the MP tape front coat is more susceptible to creep than the ME tape front coat. The strain distributions in future magnetic tapes were also simulated by reducing the thickness and compliance of the layers. Results showed the importance of using lower compliance front coat, substrate, and back coat materials if thinner tapes are to be developed to increase the volume of information that can be stored in a magnetic tape reel. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1142–1160, 2001

The superposition of discrete-time Markov renewal processes with an application to statistical multiplexing of bursty traffic sources

The main contribution in this paper is the introduction of a methodology for approximately characterizing the superposition process of N⩾2 arbitrary (and possibly heterogeneous) discrete-time Markov Renewal Processes (MRP). In this model, the superposition process is characterized by a MRP with a state space that grows exponentially with N. We consider an on/off traffic source model, where the distribution of the on and off periods is arbitrary, as a special case of the general MRP. Subsequently, a queueing model for a FIFO finite-buffer multiplexer with arbitrary on/off input sources is analyzed. We provide numerical results for testing the algorithms introduced in the paper. We also study the effect of some of the statistical properties of on/off input sources on the multiplexer's performance.