Image compression using VQ-BTC

Vector quantization (VQ) and block truncation coding (BTC) are successful image compression techniques. However, a reproduced image using VQ or BTC suffers from edge degradation. A new technique that combines the advantages of both VQ and BTC to combat this degradation is presented and is referred to as VQ-BTC. In VQ-BTC, a low-detail block is encoded using VQ. For a high-detail block, a modification of BTC is used to determine the locations of the relatively lighter and relatively darker pixels inside the block and VQ is then used to encode each. VQ-BTC provides improved edge reproduction and much lower bit rates than those obtained by BTC     

HEED: a hybrid, energy-efficient, distributed clustering approach for ad hoc sensor networks

Topology control in a sensor network balances load on sensor nodes and increases network scalability and lifetime. Clustering sensor nodes is an effective topology control approach. We propose a novel distributed clustering approach for long-lived ad hoc sensor networks. Our proposed approach does not make any assumptions about the presence of infrastructure or about node capabilities, other than the availability of multiple power levels in sensor nodes. We present a protocol, HEED (Hybrid Energy-Efficient Distributed clustering), that periodically selects cluster heads according to a hybrid of the node residual energy and a secondary parameter, such as node proximity to its neighbors or node degree. HEED terminates in O(1) iterations, incurs low message overhead, and achieves fairly uniform cluster head distribution across the network. We prove that, with appropriate bounds on node density and intracluster and intercluster transmission ranges, HEED can asymptotically almost surely guarantee connectivity of clustered networks. Simulation results demonstrate that our proposed approach is effective in prolonging the network lifetime and supporting scalable data aggregation.     

Teeth segmentation in digitized dental X-ray films using mathematical morphology

Automating the process of postmortem identification of individuals using dental records is receiving increased attention. Teeth segmentation from dental radiographic films is an essential step for achieving highly automated postmortem identification. In this paper, we offer a mathematical morphology approach to the problem of teeth segmentation. We also propose a grayscale contrast stretching transformation to improve the performance of teeth segmentation. We compare and contrast our approach with other approaches proposed in the literature based on a theoretical and empirical basis. The results show that in addition to its capability of handling bitewing and periapical dental radiographic views, our approach exhibits the lowest failure rate among all approaches studied.     

Exponential spline perfect reconstruction,decomposition and reconstruction with applications in compression and denoising

B-splines caught interest of many engineering applications due to their merits of being flexible and provide a large degree of differentiability and cost/quality trade-off relationship. However, they have less impact with continuous-time applications as they are constructed from piecewise polynomials. On the other hand, exponential spline polynomials (E-splines) represent the best smooth transition between continuous and discrete domains as they are made of exponential segments. In this paper, we present a complete analysis for an E-spline-based subband coding (wavelet) perfect reconstruction (PR) system. Derivations for the scaling and wavelet functions are presented, along with application of the proposed system in image compression and image denoising. In image compression, a comparison of the proposed technique compared with the B-spline-based PR system as well as the basic wavelet subband system with the SPIHT image codec is presented. In image denoising, we report the enhancement achieved with the proposed E-spline-based denoising approach compared with B-spline-based denoising and another basic denoising technique. In both applications, E-splines show superior performance as will be illustrated.     

Synthesis of some new 2‐[(2,3‐dihydroinden‐1‐ylidene) hydrazinyl]‐4‐methylthiazole derivatives for simultaneous dyeing and finishing for UV protective cotton fabrics

Several 2‐[1‐(1,2‐dihydroinden‐3‐ylidene) hydrazono]‐5‐aryldiazo‐4‐methyl‐1,3‐thiazoles were synthesized by reaction of 1‐(1,2‐Dihydroinden‐3‐ylidene) thiosemicarbazide with different hydrazonyl chlorides. The products are water insoluble and UV absorbers, expressed UPF‐rating values, and their H₂O/DMF solutions were used in simultaneous dyeing and resin finishing of cotton fabrics. Results obtained show that finishing of cotton samples in presence of any of that dyes, irrespective of dye concentration, brings about an improvement in percent nitrogen, wrinkle recovery angle (WRA), dyeability, and UV protection rating values along with slight decrease of tensile strength (TS) compared with the untreated samples. Irrespective of dye structure, increasing the dye concentration from 0.5 and up to 1.7% results in an improvement in the percent nitrogen, TS and a remarkable improvement in both the dyeability, UPF‐rating values along with slight decrease in WRA and lower fastness properties of the treated fabrics. The treated fabrics was characterized using energy dispersive X‐ray analysis indicating the entrapped dye within the fabric structure. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

A time-stepping DRBEM for the transient magneto-thermo-visco-elastic stresses in a rotating non-homogeneous anisotropic solid

The main objective of this paper is to study the transient magneto-thermo-visco-elastic stresses in a non-homogeneous anisotropic solid placed in a constant primary magnetic field acting in the direction of the z-axis and rotating about it with a constant angular velocity. The system of fundamental equations is solved by means of a dual-reciprocity boundary element method (DRBEM). In the case of plane deformation, a numerical scheme for the implementation of the method is presented and the numerical computations are carried out for the temperature, displacement components and thermal stress components. The validity of DRBEM is examined by considering a magneto-thermo-visco-elastic solid occupies a rectangular region and good agreement is obtained with the results obtained by other methods. The results obtained are presented graphically to show the effect of inhomogeneity on the displacement components and thermal stress components.     

Genetic single objective optimisation for sizing and allocation of renewable DG systems

The optimal design of renewable-based distributed generations (DGs) is a challenging issue in order to maximise their benefits and to overcome power quality problems. Therefore, this paper proposes a methodology for optimal allocation and sizing of renewable DG units to minimise total power losses over radial distribution systems. The planning problem is formulated as a single objective nonlinear mixed integer-constrained optimisation problem and is solved by using the augmented Lagrangian genetic algorithm (ALGA) by combining the objective function and the nonlinear constraints. In that case, the ALGA solves a sequence of sub-problems where the objective function penalises the constraints violation in order to obtain the best solution. The proposed technique is applied to IEEE radial test systems including 33-bus, 69-bus and 119-bus and is implemented with different scenarios including all possible combinations and various types of renewable DG units to prove the effectiveness of the proposed methodology.     

17—QUANTITATIVE ANALYSES OF WEFT-KNITTED STRUCTURES PART IV: THE DETERMINATION OF THE MAGNITUDES OF B1, B2, AND B3 AND THE EXTENSION OF THE WORK TO GENERAL MULTI-COLOUR-JACQUARD STRUCTURES

The optimum design of experiment for the determination of the magnitudes of the component units of the weft-knitted jacquard structures, B ₁, B ₂, and B ₃, is discussed in detail. Some experimental results are reported. The prediction accuracy of using the technique of independent distinct units (IDU), by means of a suggested optimum experiment, proved to be very satisfactory in predicting the length of yarn of one design repeat of an arbitrary two-colour-jacquard example. The extension of the work to general multi-colour-jacquard structures is given.