Dicke state generation using cross-Kerr nonlinearity

In this paper, we propose two ways of Dicke state generation using single photons and weak coherent pulse resorting to Kerr nonlinearities. By interference of two coherent beams, the Dicke state are realized in polarization and photon number degrees of freedom. By performing homodyne detection on the coherent states, the multi-particle entangled Dicke state can be generated with a high probability. The realization of the protocols are more flexible as the phase differences can be easily distinguished during homodyne detection.     

Optical vortices generation using the Wollaston prism

A new setup of interferometers is proposed in which the set of specific optical markers--optical vortices--could be generated. The classical Mach-Zender two-beam interferometer has been modernized using the Wollaston prism. In this setup, the optical vortices could be obtained for a wide range of both beam parameters. The numerical analysis and experiments confirm our theoretical predictions.     

Colour image coding scheme using absolute moment block truncation coding and block prediction technique

Abstract

A predictive colour image compression scheme based on absolute moment block truncation coding is proposed. In this scheme, the high correlations among neighbouring image blocks are exploited by using the similar block prediction technique. In addition, the bit plane omission technique and the coding of quantisation levels are used to cut down the storage cost of smooth blocks and complex blocks respectively. According to the experimental results, the proposed scheme provides better performance than the comparative schemes based on block truncation coding. It provides better image qualities of compressed images at low bit rates. Meanwhile, it consumes very little computational cost. In other words, the proposed scheme is quite suitable for real time multimedia applications.     

A new finite point generation scheme using metric specifications

A new approach to generate finite point meshes on 2D flat surface and any bi‐variate parametric surfaces is suggested. It can be used to generate boundary‐conforming anisotropic point meshes with node spacing compatible with the metric specifications defined in a background point mesh. In contrast to many automatic mesh generation schemes, the advancing front concept is abandoned in the present method. A few simple basic operations including boundary offsetting, node insertion and node deletion are used instead. The point mesh generation schemeis initialized by a boundary offsetting procedure. The point mesh quality is then improved by node insertion and deletion such that optimally spaced nodes will fill up the entire problem domain. In addition to the point mesh generation scheme, a new way to define the connectivity of a point mesh is also suggested. Furthermore, based on the connectivity information, a new scheme to perform smoothing for a point mesh is proposed toimprove the node spacing quality of the mesh. Timing shows thatdue to the simple node insertion and deletion operations, the generation speed of the new scheme is nearly 10 times faster than a similar advancing front mesh generator. Copyright © 2000 John Wiley & Sons, Ltd.     

Optical state measurement by information transfer

Abstract

Mathematically, the simplest state of light containing phase information is a superposition of the vacuum and the one-photon state and, as we show in this paper, such a state is reasonably simple to measure. We investigate how the information contained in a more complicated pure state of light, in particular the ratio of successive number-state coefficients, can be transferred selectively to fields in this two-state superposition for subsequent measurement. By this means the number-state representation of the more complicated state can be ascertained, provided there are no gaps in the number state distribution. We also discuss how to correct for the effect of non-unit efficiencies of the photodetectors involved in the transferral process.     

Optical sensing scheme for carbon dioxide using a solvatochromic probe

The novel sensing scheme, unlike previous ones that are based on the use of pH indicator probes, is making use of solvatochromic probe Nile Red (NR). Dissolved in a matrix of ethyl cellulose, it can report the polarity of its microenvironment that is modulated by an additive (a hydrophobic amidine) that is capable of reversibly binding carbon dioxide. The spectra of NR undergo a strong solvatochromic shift both in color (from brick-red to magenta) and in fluorescence (from orange to red) if the respective sensor layer is exposed to gaseous CO(2) (gCO(2)) or dissolved CO(2) (dCO(2)). Both visual and instrumental readouts are possible. The sensor layer responds to gCO(2) in the range from 0 to 100% and to dCO(2) in the range from 0 to 1 M solutions of bicarbonate (equivalent to a CO(2) partial pressure of up to 255 hPa). The detection limits are around 0.23% for gCO(2) and 1.53 hPa for dCO(2). The response time is in the order of 10 min in the forward direction and 3 min in the reverse direction for gCO(2) but up to 25 min in the case of dCO(2). The optical response also was quantified using a digital camera by extracting the spectral information using the blue and green color channels (in reflectometry) and the green and red channels (in fluorescence), respectively, and by generating pseudocolor pictures.     

Analyzing dissipation effects on the non-classicality witnessing by a qubit via the entangled state representation

ABSTRACT

In this paper, we study detection of the state non-classicality for a quantum harmonic oscillator by a qubit in the presence of dissipation effects. We show that dissipation can enhance the effectiveness of the method in case of using the corrected form of the related nonclassicality witness. Such an improvement is attributed to the fact that dissipation leads to probing a surface, instead of a curve, of the complex plane for non-classicality condition on normally-ordered characteristic function.     

Minimising makespan on a batch processing machine using heuristics improved by an enumeration scheme

Batch processing machines can process several job simultaneously and are encountered in many manufacturing environments. Jobs in a batch are processed together and have the same start and end processing time. Since jobs are non-identical in job sizes and job processing times, they should be reasonably scheduled to improve the machine utilisation and processing efficiency. Two well-known heuristics, first fit longest processing time and best fit longest processing time (BFLPT), are improved in this study by considering identical job sizes and then BFLPT is further improved by an enumeration scheme proposed. Computational experiments are conducted to evaluate the performance of the improvement and the results are compared with the existing heuristics.     

Automatic test case generation using unified modeling language (UML) state diagrams

UML is widely accepted and used by industry for modelling and design of software systems. A novel method to automatically generate test cases based on UML state models is presented. In the present approach, the control and data flow logic available in the UML state diagram to generate test data are exploited. The state machine graph is traversed and the conditional predicates on every transition are selected. Then these conditional predicates are transformed and function minimisation technique is applied to generate test cases. The present test data generation scheme is fully automatic and the generated test cases satisfy transition path coverage criteria. The generated test cases can be used to test class as well as cluster-level state-dependent behaviours.     

Optical control of layered nanomaterial generation by pulsed-laser ablation in liquids

ABSTRACT

Pulsed-laser ablation in liquids capitalizes on combining chemical and optical control to rapidly generate size, composition, and phase-controlled nanostructures, without the need for surfactants. Very high temperatures, which we determined to be ca. (8,400?±?1,300) K, pressures, and ion densities exist in the laser-induced liquid-confined plasma. These unique conditions, coupled with the rapid cooling during which nanoparticles are formed, permitted access to new extreme regions of materials’ phase diagrams. This way, we produced metastable layered copper and zinc hydroxide-based nanocrystals with interesting physical properties that can serve as precursors for two-dimensional inorganic semiconductor nanomaterials.     

Optical generation of millimeter-wave pulses using a fiber Bragg grating in a fiber-optics system

A scheme is proposed to transform an optical pulse into a millimeter-wave frequency modulation pulse by using a weak fiber Bragg grating (FBG) in a fiber-optics system. The Fourier transformation method is used to obtain the required spectrum response function of the FBG for the Gaussian pulse, soliton pulse, and Lorenz shape pulse. On the condition of the first-order Born approximation of the weak fiber grating, the relation of the refractive index distribution and the spectrum response function of the FBG satisfies the Fourier transformation, and the corresponding refractive index distribution forms are obtained for single-frequency modulation and linear-frequency modulation millimeter-wave pulse generation. The performances of the designed fiber gratings are also studied by a numerical simulation method for a supershort pulse transmission.     

Framing the performance of induced magnetic field and entropy generation on Cu and TiO2 nanoparticles by using Keller box scheme

Aim of present communication is to inspect the impact of induced magnetic field and entropy generation on water based nanofluid. The thermal characteristic of nanofluids are explored using copper and titanium nanoparticles. The governing physical problem is modelled and by using scaling group of transformations. Obtained system of coupled nonlinear partial differential equations is converted into set of ordinary differential equations. These equations are solved numerically using implicit finite difference scheme. Entropy generation analysis is carried out to measure the disorder within the thermodynamical system. Effect of nanoparticles volume fraction on magnetic field components, skinfriction and local heat flux are computed and discussed in a physical manner. It is examined that magnetic field parameter reduces wall stress while it increases rate of heat transfer at surface. Local heat flux accelerate with increasing nanoparticles volume fraction. ${\text{TiO}}_2$ water based nanofluid showed better results for heat transfer than $\text{Cu}$ water based nanofluid.     

Second harmonic generation using an electrically controlled asymmetric plasmonic waveguide

ABSTRACT

In this study, it was shown that field enhancement in the nonlinear metal-insulator-metal (MIM) plasmonic waveguides can result in a large enhancement of the second harmonic generation (SHG) magnitude as compared with values reported in the literature. The proposed structure has two metals at the top and two metals at the bottom of the crystal. In this structure, a voltage is applied on metals to produce a SHG electrically. Hence, the metals that define the cavity also serve as electrodes capable of generating high direct current electric fields across the nonlinear material. The frequency of a fundamental wave at 458 nm was doubled and modulated in intensity by applying a moderate external voltage to the electrodes, yielding a voltage-dependent nonlinear generation with a higher coupling efficiency. All the simulations here have been calculated by using the finite-element-based commercial COMSOL software.     

Frequency domain down-conversion of HDTV using an optimal motion compensation scheme

In the MPEG-2 Test Model 5, the down-conversion of an interlaced sequence is obtained by prefiltering and subsampling each field of the image sequence after it has been fully decoded. Although the quality is very good, the cost of such a system is quite high owing to large memory requirements. As a result, low-resolution decoders have been proposed to reduce some of the costs incurred by this scheme. Here, incoming Discrete Cosine Transform (DCT) blocks are subject to a down-conversion process within the decoding loop; hence, the motion compensation is performed using the down-converted images. In past work, it has been proven that the optimal filters for performing this motion compensation are intimately related to the method of down-conversion. Therefore, the choice of down-conversion filter is viewed as the primary variable affecting the quality of the down-converted sequence when such an optimal motion compensation scheme is considered. In the conventional method of frequency domain down-conversion, the 4 × 4 low-frequency coefficients are extracted from each 8 × 8 block. Two problems arise from this method: First, the discarding of high frequency data will introduce a disturbing amount of drift; and second, severe blocking artifacts will result in areas of large motion. To remedy the drift problem, a new method of down-conversion which better preserves high-frequency data is presented. This method is referred to as frame-based frequency synthesis. Then, to overcome the blocking artifacts, the previous method is extended to a field-based frequency synthesis method. Our simulation results clearly indicate that the amount of drift can be significantly reduced by retaining high-frequency data and that severe blocking artifacts are eliminated by using the field-based method. In addition, the quality achieved by the proposed field-based frequency synthesis is much closer to the high-quality results produced after full-resolution decoding. © 1998 John Wiley & Sons, Inc. Int J Imaging Syst Technol, 9, 274–282, 1998     

Automatic mesh generation and adaptation by using contours

A general and efficient remeshing algorithm is presented for the discretization of arbitrary planar domains into triangular elements in consistency with the given node spacing function. The contour lines of the node spacing function at suitable calculated levels provide the natural lines of division of the problem domain into subregions, where finite element meshes of different element sizes are generated using the available general-purpose mesh generators.^{1, 2} Examples of remeshing for various node spacing functions are given to illustrate that high-quality gradation meshes can be generated automatically without any user's intervention by this simple contour line method.     

Cutting path generation of the Stewart-Platform-Based Milling Machine using an end-mill

This paper investigates an algorithm for generating the cutting path of a Stewart-Platform-Based Milling Machine (SPBMM) using an end-mill. While using the iso-scallop method in the process of generating the cutting path, we use the Genetic Algorithm (GA) to find the configurations of the tool without a singular position. After choosing the objective function, using GA to find the optimum value is an extremely effective method for both quickly converging to a reasonable value and avoiding a futile blind search. In our results, when the curvature of the workpiece is equal to the curvature of the cutter at the contact point, one equation in terms of curvature and two degrees of freedom of the end-mill are formed. Keeping the six axial forces of the SPBMM as small as possible is our objective function. We can find an optimal set of solutions in this equation at every contact point. Finally, we find a planned cutting path without a singular position.     

Shape optimization of flow guides in three‐dimensional extrusion processes by an approximation scheme based on state variable linearization

A new scheme of shape optimization is applied to the design of a flow guide in flat‐die extrusion processes. In general, tremendous time is inevitably required for the optimization of large‐scale three‐dimensional extrusion processes. This is because the finite element analysis requires large computation time owing to the complexity of the die geometry and flow behaviour. The proposed scheme effectively reduces the computation time for the optimization process by approximating the objective function. This is achieved by introducing a transformed equation of the state variables. The scheme is then applied to the practical extrusion processes to produce ‘l’, ‘H’ and ‘L’ sections. The objective of the optimization is to make a balanced flow of the material in the exit region. Control points of a Bezier curve describing the outline of the flow guide are regarded as the design variables. Through application to large‐scale problems, the effectiveness and usefulness of the proposed scheme is demonstrated. Copyright © 2005 John Wiley & Sons, Ltd.     

Optical zooming interferometer for subnanometer positioning using an optical frequency comb

A high-precision positioning stage based on an optical zooming interferometer is proposed. Two external-cavity diode lasers, stabilized to a femtosecond optical frequency comb, are used as optical sources. The zooming principle is demonstrated, and the positioning resolution of 0.2 nm is achieved. The positioning accuracy was partly evaluated.     

Efficient laser-ultrasound generation by using heavily absorbingfilms as targets

An efficient all-fiber optic source is presented; it adopts absorbing films, deposed directly over the fiber tip, as targets. It is demonstrated that the use of absorbing films made of pure graphite, or graphite powder mixed with epoxy resin, has produced a conversion efficiency increase of two orders of magnitude with respect to metallic materials. It is observed that the conversion efficiency increases monotonically as thickness is reduced down to the material optical penetration depth. Moreover, the conversion efficiency rises with the concentration of graphite powder. Principal advantages of this kind of source are the ease of production and miniaturization, the excellent electromagnetic compatibility, wide ultrasonic bandwidth and, consequently, high spatial resolution. The ultrasonic bandwidth can be controlled by varying the laser pulse duration. The possibility of generating ultrasonic signals with high frequency and flat spectral distribution makes the proposed device suitable for biological tissue spectral characterization