This paper proposes a new method for image binarization that uses an iterative partitioning approach. The proposed method has been tested towards binarization of both document and graphic images. The quantitative comparisons with other standard methods reveal that the proposed approach outperforms existing widely used binarization techniques in terms of accuracy of binarization. The experimental results further establish the superiority of the proposed method, especially for degraded documents and graphic images. The proposed algorithm is suitable for a multi-core processing environment as it can be split into multiple parallel units of executions after the initial partitioning. 相似文献
Predicate (PA) and numeric (NA) abstractions are the two principal techniques for software analysis. In this paper, we develop
an approach to couple the two techniques tightly into a unified framework via a single abstract domain called NumPredDom. In particular, we develop and evaluate four data structures that implement NumPredDom but differ in their expressivity and internal representation and algorithms. All our data structures combine BDDs (for efficient
propositional reasoning) with data structures for representing numerical constraints. Our technique is distinguished by its
support for complex transfer functions that allow two-way interaction between predicate and numeric information during state
transformation. We have implemented a general framework for reachability analysis of C programs on top of our four data structures.
Our experiments on non-trivial examples show that our proposed combination of PA and NA is more powerful and more efficient
than either technique alone. 相似文献
Two Lock-in InfraRed Thermography (LIRT) techniques were developed and applied to detect interfacial defects in a ceramic coated steel plate deposited by plasma spraying technology. Stimulations were performed either by electromagnetic waves (lamps) or by high power ultrasonic waves (sonotrode). The first one is based on remote optical heating of the area of interest; while the second technique is based on the mechanical loss angle effect, occurring locally and for particular defects such as cracks and delaminations. The potential of these two techniques was evaluated against artificial (calibrated holes) and real (disbonding) interfacial defects. The results show success and also some limitations of both LIRT techniques in function of sizes and depths of ceramic coating interfacial defects. 相似文献
A model is proposed to explain on a unified basis the role of boron in enhancing ductility and reducing environmental embrittlement in polycrystalline Ni3Al. The grain boundaries in strongly ordered Ni3Al have a porous structure with crack-like microcavities, which can open up under small stresses. Furthermore, atomic hydrogen, generated by the reaction of environmental moisture with Al, can diffuse to the tips of the microcavities under stress and can cause embrittlement. It is argued that strong bonding between interstitial B atoms and Ni atoms in B-doped Ni3Al reduces the strength of directional bonding between Ni and Al atoms in the interior of the grains. When two such grains with weakened Ni---Al bonding meet each other, the atoms near the grain boundary can relax easily and close up the microcavities. As a result, the ductility is enhanced in B-doped Ni3Al. The environmental embrittlement is also reduced, because a small amount of environmental hydrogen cannot nucleate microcracks. Numerous experimental observations have been explained with the proposed mechanism. 相似文献
Powder of lanthanum-modified lead zirconate titanate (PLZT) with the composition La/Zr/Ti=8/65/35, was synthesized from aqueous
nitrate solutions. A single-phase PLZT was obtained at ∼550 °C. The reactivity of the powder during low-temperature heating
was determined using X-ray diffraction and various thermal analysis techniques. The dielectric properties of the compound
were also studied at 1 and 10 kHz frequency from room temperature to 200 °C. Diffuse phase transition (DPT) in the material
was observed around 136 °C at 1 kHz. An increase in peak-permittivity temperature (i.e. the transition temperature) with increasing
frequency (a characteristic of relaxor ferroelectrics) was also observed. 相似文献
The design and feasibility of a simple and practical system for measuring two-parameter signals is reported. A dual-parameter multichannel pulse-height analyzer (MCA) which uses two central processing units (CPUs) is developed and designed. One computer (master computer) controls the other computer (slave computer), and also displays, records, and analyzes the data. The slave computer controls two analog-to-digital converters (ADCs), collects the dual-parameter data, and transfers the collected data to the master computer. Three methods of data transfer between the two CPUs are examined and discussed. The count capacity at the data collection by the slave computer is 216-1/ch (2-B-long data), and this is expanded to 232-a/ch (4-B-long data) at the master computer. The data are analyzed and at any time stored in the storage apparatus by the dual CPU system. The system demonstrates stable operation over long measurement periods 相似文献
The conductive composites were prepared using two different types of conductive black (Conductex and Printex XE2) filled in
matrices like EVA and NBR and their different blends. The electromagnetic interference shielding effectiveness (EMI SE) of
all composites was measured in the X band frequency range 8–12 GHz. Both conductivity and EMI SE increase with filler loading.
However, Printex black shows higher conductivity and better EMI SE at the same loading compared to Conductex black, and this
can be used as a material having high EMI shielding effectiveness value. The conductivity of different blends with same filler
loading generally found to increase slightly with the increase in NBR concentration. However, EMI SE has some dependency on
blend composition. EMI SE increases linearly with thickness of the sample. EMI SE versus conductivity yields two master curves
for two different fillers. EMI SE depends on formation of closed packed conductive network in insulating matrix, and Printex
black is better than Conductex black in this respect. Some of the composites show appreciably high EMI SE (>45 dB). 相似文献
Polystyrene foams have been generated and fabricated into differently shaped structures', by change of steaming period under constant impregnation time and solvent-nonsolvent composition. Optical photomicrographs of samples both plain and wax-copper-coated reveal uniform appearance, distinct grain-boundaries, and random cell size distribution. Dielectric measurements have been made on test specimens cut according to wave-guide size at 9.375 GHz X-band microwave frequency by short-circuited wave-guide method of Smith and Hippel modified by Dakin and Works. Dielectric constants are linear, on direct and semi-log scales in bulk-density and volume-fraction, obeying Weiner's inequalities. Formulae of Landau-Lifshitz, Beer, Maxwell-Wagner, Odelevsky, etc. have been tried. Data fit best with the logarithmic law of Lichtenecker and Rother. Specific polarization is also a true function of density. Dielectric constant vs bulk-density plots of foams resemble dielectric-constant vs fractional-density plots based on the theoretical derivation by Smith for polystyrene compacts, signifying that compacts containing closely-spaced oblong-spherical particles arc physically similar to foams having spherical gas inclusions in plastic structures. Tan δ lying in the range 0.002–0.0038 results from conformational polarization (β-relaxation at room-temperature for wide-angle torsional oscillations of side-groups with co-operative motion from wriggling chains). It is therefore possible for low-loss foam dielectrics suitable for micro-wave applications to be made by this method. 相似文献
The single crystals of quaternary transition metal chalcogenide Cu2ZnSnS4 (CZTS) are grown by a closed system chemical vapor transport technique. The high purity individual elemental precursors are employed in the growth of the crystals. These crystals are found to be single-phase by X-ray diffraction and Raman analysis. The near stoichiometry of the grown crystals is confirmed by spectroscopy analysis of the photoelectron generated by X-rays and analysis of the energy of the dispersive X-rays generated by electrons. The surface study by scanning electron microscopy showed the growth to happen by sheet spread mean and the electron diffraction showed fringe width match with (112) plane spacing. The study of the CZTS/Ag-paste/Cu-wire system for incident white light and three wavelengths of laser lights in two configuration modes of top-contact (II to the plane) and bottom-top-contact (⊥ to the plane) showed anisotropic behavior. The incident white light illumination intensity of 120 mW/cm2 showed utmost photoresponse. The top-contact mode configuration showed maximum responsivity and detectivity of 0.72 mA/W and 0.33 × 109 Jones, respectively, while bottom-top-contact showed 0.18 mA/W and 0.13 × 109 Jones, respectively. The anisotropic photoresponse by the CZTS crystals insinuates the potential for future applications.