Image coding algorithm based on Hadamard transform and simple vector quantization

Transform coding is commonly used in image processing algorithms to provide high compression ratios, often at the expense of processing time and simplicity of the system. We have recently proposed a pixel value prediction scheme in order to exploit adjacent pixel correlation, providing a low-complexity model for image coding. However, the proposed model was unable to reach high compression ratios retaining high quality of reconstructed image at the same time. In this paper we propose a new segmentation algorithm which further utilizes adjacent pixel correlation, provides higher compression ratios and it is based on application of Hadamard transform coding. Additional compression is provided by using vector quantization for a low number of quantization levels and by simplifying generalized Lloyd’s algorithm where the special attention is paid to determination of optimal partitions for vector quantization, making a fixed quantizer. The proposed method is quite simple and experimental results show that it ensures better or similar rate-distortion ratio for very low bit-rates, comparing to the other similar methods that are based on wavelet or curvelet transform coding and support or core vector machine application. Furthermore, the proposed method requires very low processing time since the proposed quantizers are fixed, much less than the required time for the aforementioned methods that we compare with as well as much less than the time required for fractal image coding. In the end, the appropriate discussion is provided comparing the results with a scheme based on linear prediction and dual-mode quantization.

     

A complete quantitative model of the isothermal vapor phase epitaxy of (Hg,Cd)Te

A quantitative model of isothermal vapor phase epitaxy is proposed. It can be applied to both closed and open tube systems. This model enables the prediction of compositional profiles of the layers grown by isothermal vapor phase epitaxy with dependence on the growth parameters and thermodynamical data of the (Hg,Cd)Te system. The dependence of compositional profiles of the ISOVPE layers on temperature and time of deposition, source to substrate spacing, mercury and inert gas pressures are discussed for both solid and liquid sources. Modification of the compositional profiles by the postgrowth annealing has also been studied. The proper choice of growth and annealing parameters makes the optimization of the profiles possible. The calculated profiles are compared with the experimental data and a satisfactory quantitative fit is found in most cases. The possible reasons for remaining discrepancies are discussed.     

Wireless smart camera network for real-time human 3D pose reconstruction

A multiple-camera system for 3D pose reconstruction is presented. First, body parts of the user are detected. Each camera has a single-instruction multiple-data (SIMD) processor used to perform this heavy-load image processing task. The detected hand and head candidate positions are then transmitted wirelessly from each camera to a central processor using a low-power ZigBee network. Finally, the 3D pose reconstruction is performed at the central processor by combining the data in a probabilistic manner.     

Semantic Mediation for Standard-Based B2B Interoperability

The authors discuss a semantic-mediation architecture to advance traditional approaches for standards-based business-to-business (B2B) interoperability. The architecture is supported by the Athena Knowledge Representation and Semantics Mediation tool suite. Initial experimentations with the architecture and the toolset offer discussions of key architectural and functional aspects and suggest directions for future tools enhancements.     

Detection of Structural Features in Biological Signals

In this article structures in biological signals are treated. The simpler—directly visible in the signals, which still demand serious methods and algorithms in the feature detection, similarity investigation and classification. The major actions in this domain are of geometric, thus simpler sort, though there are still hard problems related to simple situations. The other large class of less simple signals unsuitable for direct geometric or statistic approach, are signals with interesting frequency components and behavior, those suitable for spectroscopic analysis. Semantics of spectroscopy, spectroscopic structures and research demanded operations and transformations on spectra and time spectra are presented. The both classes of structures and related analysis methods and tools share a large common set of algorithms, all of which aiming to the full automatization. Some of the signal features present in the brain signal patterns are demonstrated, with the contexts relevant in BCI, brain computer interfaces. Mathematical representations, invariants and complete characterization of structures in broad variety of biological signals are in the central focus.     

The nature and impacts of fines in smelter-grade alumina

Fines in smelter-grade aluminas are recognized as a significant process problem in aluminum smelting. However, understanding the nature of this fine material and how it impacts the reduction process are less clearly understood. The combination of new analytical methods such as variable pressure scanning electron microscopy and very high field solid state nuclear magnetic resonance provide new insights into the phases present and their spatial distribution within aluminas, and suggest how such fine materials are generated, particularly during calcination in the alumina refinery.     

An adaptive partitioning approach for mining discriminant regions in 3D image data

Mining discriminative spatial patterns in image data is an emerging subject of interest in medical imaging, meteorology, engineering, biology, and other fields. In this paper, we propose a novel approach for detecting spatial regions that are highly discriminative among different classes of three dimensional (3D) image data. The main idea of our approach is to treat the initial 3D image as a hyper-rectangle and search for discriminative regions by adaptively partitioning the space into progressively smaller hyper-rectangles (sub-regions). We use statistical information about each hyper-rectangle to guide the selectivity of the partitioning. A hyper-rectangle is partitioned only if its attribute cannot adequately discriminate among the distinct labeled classes, and it is sufficiently large for further splitting. To evaluate the discriminative power of the attributes corresponding to the detected regions, we performed classification experiments on artificial and real datasets. Our results show that the proposed method outperforms major competitors, achieving 30% and 15% better classification accuracy on synthetic and real data respectively while reducing by two orders of magnitude the number of statistical tests required by voxel-based approaches.     

Investigation of the rotary swaging and heat treatment on the behavior of W- and γ-phases in PM 92.5W–5Ni–2.5Fe–0.26Co heavy alloy

The effects of rotary swaging and different heat treatment procedures on the W- and γ-phases behavior of PM 92.5W–5Ni–2.5Fe (wt.%) heavy alloy microalloyed with cobalt have been studied. The investigation was performed on sintered and cold rotary swaged samples deformed with area reduction from 5 to 30%. One batch of swaged samples was annealed in vacuum at 1473 K for 7.2 ks and then furnace-cooled to the room temperature, whereas another batch of swaged samples was previously deformed 30% and strain aged in argon and nitrogen in the temperature range between 473 and 1123 K for 3.6 ks. Strengthening of W- and γ-phases was investigated by applying microhardness measurements. Effects of the degree of deformation, parameters of heat treatment and strain aging on microstructural changes have been studied. Mechanical properties, hardness and microhardness of phases as a function of the degree of deformation and heat treatment were analyzed by applying statistical modeling. A correlation between deformation behavior of phases, effect of heat treatment and alloy properties was also discussed.     

New Digital Algorithm for Adaptive Reclosing Based on the Calculation of the Faulted Phase Voltage Total Harmonic Distortion Factor

This paper presents a new numerical algorithm suitable for determining adaptive dead time, and blocking automatic reclosing during permanent faults on overhead lines. It is based on terminal voltage input data processing. The decision if it is safe or not to reclose is determined by the voltage signal of faulted and tripped line phase using the total harmonic distortion factor calculated by discrete Fourier transform. The algorithm was successfully tested using signals recorded on the real power system. The tests demonstrate the ability of the presented algorithm to determine the secondary arc extinction time and to block unsuccessful automatic reclosing of high-voltage lines with permanent fault     

Salting-out in Aqueous Solutions of Ionic Liquids and K3PO4: Aqueous Biphasic Systems and Salt Precipitation

The salting-out effect produced by the addition of potassium phosphate, K₃PO₄ to aqueous solutions of water-miscible ionic liquids, viz. 1-ethyl-3-methylimidazolium ethyl sulfate, 1-butyl-3-methylimidazolium methyl sulfate, or 1-alkyl-3-methylimidazolium chloride (alkyl = butyl, octyl or decyl) is investigated. The effects are analyzed using both the corresponding temperature–composition pseudo-binary and composition ternary phase diagrams. Different regions of liquid-liquid and solid-liquid phase demixing are mapped. The phase behavior is interpreted taking into account the complex and competing nature of the interactions between the ionic liquid, the inorganic salt and water. In the case of solutions containing 1-octyl- or 1-decyl-3-methylimidazolium chloride, the smaller magnitude of the salting-out effects is explained in terms of the possibility of self-aggregation of the ionic liquid.