Data interpretation for spectral sensors with correlated bands

New classes of spectral sensors are emerging that have significant overlap in the band spectral response functions. While conventional sensors such as the Multispectral Thermal Images (MTI) or Landsat may have responses with a few percent overlap between adjacent bands, some of the emerging sensors can have more than 50% correlation among all spectral bands. The traditional geometrical models used to describe spectral data fail when such high levels of correlation exist. In this paper we present a generalized geometrical model that relies on functional analysis. We define a sensor space and a scene space that can be used to characterize the suitability of a sensor for a particular spectral sensing task. We demonstrate that classifiers based on first-order distance and angle metrics fail for sensors with highly correlated bands unless appropriate preprocessing is carried out. We further show that second-order statistical classifiers are largely immune to many of the problems introduced by the correlated band responses.     

Nb Substituted Cu0.5Tl0.5Ba2(Ca3Nb1)Cu5O_{14-\delta} and Cu0.5Tl0.5Ba2(Ca4Nb1)Cu6O_{16-\delta} Superconductors

The effects of higher electro-negativity Nb substitution on the Ca site in Cu_0.5Tl_0.5Ba₂ (Ca₃Nb₁)Cu₅O $_{14-\delta}$ and Cu_0.5Tl_0.5Ba₂(Ca₄Nb₁)Cu₆O $_{16-\delta}$ superconductors have been investigated. The Nb doping has been found to increase the oxygen contents in Cu_0.5Tl_0.5Ba₂O $_{16-\delta}$ charge reservoir layer of the final compound. The post-annealing in the N₂ atmosphere has been found to improve the superconducting properties; however, O₂ annealing produced the material with inferior superconducting properties. The quantity of diamagnetism is increased with post-annealing in the nitrogen atmosphere; as N₂ annealing helps in the formation of material with optimum carriers concentration in the CuO₂ planes, which is done by the change in the charge state of thallium from Tl³⁺ to Tl¹⁺. The Nb substitution has been found to develop the higher CuO₂ planner phases such as Cu_0.5Tl_0.5Ba₂Can _?2Nb₁Cun ₂ n+4?δ (n=5,6) with enhanced T _c's.     

RECENT DEVELOPMENTS IN AEROSPACE PROPULSION MATERIALS

ＲＥＣＥＮＴＤＥＶＥＬＯＰＭＥＮＴＳＩＮＡＥＲＯＳＰＡＣＥＰＲＯＰＵＬＳＩＯＮＭＡＴＥＲＩＡＬＳＴ．Ｋｈａｎ（Ｏｎｅｒａ,Ｂ．Ｐ．７２,９２３２２ＣｈａｔｉｌｌｏｎＣｅｄｅｘ,ＦｒａｎｃｅＭａｎｕｓｃｒｉｐｔｒｅｃｅｉｖｅｄ２６Ａｕｇｕｓｔ１９９６）...     

Two novel regions of interstitial deletion on chromosome 8p in colorectal cancer

We have investigated interstitial deletions of chromosome 8 in 70 colorectal carcinomas and 11 colonic adenomas using 11 microsatellite markers, including eight spanning the centromeric region of chromosome 8p (p11.2-p12). Allelic loss or imbalance was observed in 38 (54%) cancers and four (36%) adenomas. Twenty-eight (40%) of the cancers had deletions of 8p11.2-p12. Two distinct and independent regions of interstitial loss were found within this region. Fluorescent in situ hybridization, using an alpha satellite repeat probe to the centromere of 8p and two probes to the P1 region, was performed in four tumours that demonstrated allelic imbalance. Localized heterozygous deletions were confirmed in all four tumours. Eleven (16%) cancers had localized deletion in the region ANK-1 to D8S255 (P1) and a further eleven (16%) cancers had a less well localized deletion in the region defined by the markers D8S87 to D8S259 (P2). Loss of both centromeric loci was identified in a further six (9%) tumours. A functional significance for these two deletion regions was sought by correlation with primary and secondary tumour characteristics. Isolated P2 deletion was associated with 'early' T1 cancers (2p=0.0002), and were also identified in 3/11 adenomas. Conversely, interstitial deletions of the P1 locus were more frequently seen in 'locally invasive' T3/4 cancers (2p=0.015), and isolated P1 deletions were also associated with the presence of liver metastases (2p=0.016). Our data provide evidence of at least two genes within the 8p11.2-p12 region, mutations in which may confer different and independent roles in the pathogenesis of colorectal cancer.     

Factors Influencing Biodegradable Dissolved Organic Carbon Measurement

The inocula requirements and other experimental conditions for the biodegradable dissolved organic carbon (BDOC) procedure have been investigated and optimized to facilitate its use as a routine parameter for characterizing treatment plant performance. Initial inocula of unfiltered secondary effluent, commercial biochemical oxygen demand seed, mixed-liquor suspended solids (MLSS), and incubation temperatures of 20 and 37°C were examined using standard solutions of known DOC, treatment plant effluents, and ozonated treatment plant effluents. Among all inocula tested, MLSS provides the fastest BDOC exertion rate. It is possible to measure BDOC within five days using a larger volume of MLSS inoculum. The results from this research may be used to support the development of a standard BDOC method for water quality assessment.     

The corrosion behavior of TiN coated and uncoated incoloy 800 alloy

Incoloy alloy 800 is used in a variety of applications in industry as well as in domestic appliances for sheeting on electric heating elements. The composition of the alloy enables it to resist deterioration in many corrosive environments. However, resistance of the alloy to corrosion in aqueous media needs to be further examined. The present study examines the corrosion properties of Incoloy 800 alloy of both coated and uncoated workpieces obtained in a 0.1N H₂SO₄ + 0.05N NaCl solution. TiN coating is achieved using a physical vapor deposition (PVD) technique while corrosion tests are carried out using electrochemical polarization methods. Moreover, in order to examine the influence of hydrogen diffusion, reduction of hydrogen at the Incoloy 800 surface is carried out in a solution of 0.1N HNO₃ + 1 g/L thiourea. Tensile tests are conducted on the workpieces to determine the influence of hydrogen embrittlement on the resulting mechanical properties of the substrate. To examine the pit formation and stress induced microcracking, scanning electron microscope (SEM) analysis is carried out. The results show that the corrosion resistance of the alloy improves after TiN coating. In addition, no specific pattern or differentiation on the pit geometry is observed. The pitting rate and its size reduce considerably for TiN coated workpieces.     

New design of full band differentiators based on Taylor series

The classical central difference approximations of the derivative of a function based on Taylor series are the same as type III maximally linear digital differentiators for low frequencies. A new finite difference formula is derived which can be implemented as a full band type IV maximally linear differentiator. The differentiator is compared with type III maximally linear and type IV equiripple minimax differentiators. A modification is proposed in the design to minimise the region of inaccuracy near the Nyquist frequency edge     

Mode-coupling analysis of multipole symmetric resonant add/dropfilters

Time-dependent mode-coupling theory is used to analyze a type of resonant add/drop filter based on the excitation of degenerate symmetric and antisymmetric modes. Flat-top transfer functions are achieved with higher order filters that utilize multiple resonator pairs, designed to satisfy the degeneracy conditions. The resulting analytic expressions lead to an equivalent circuit and the transfer characteristics of the filter are related to standard L-C circuit designs     

Effect of rare-earth (Eu, Yb and Ag) substitutions on superconducting properties of the Bi1.7Pb0.3 Sr2Ca2−xRx(R = Eu, Yb, and Ag)Cu3OY system

The superconducting properties of Bi^1.7Pb_0.3Sr₂Ca^2–xR^x(R = Eu, Yb and Ag)Cu₃O_Y have been investigated by X-ray diffraction, electrical resistance and the peritectic transition of these superconductors was studied kinetically under different atmospheres and temperature gradients. X-ray diffraction results show that the volume fraction of the high-T_c (2 2 2 3) phase decreases and that of the low-T_c (2 2 1 2) phase increases as Eu, Yb and Ag concentrations increase. The resistivity measurements reveal that the T_c onset decreases down to 100 K for Eu, 85 K for Yb and 106 K for Ag concentrations. These results are explained on the basis of possible variations of hole concentration with trivalent rare earth ion substitutions. Activation energies and frequency factors for crystallisation were determined by non-isothermal differential thermal analysis (DTA), employing different models. It was found that both peritectic transition and reaction rate were dependent on the ambient atmosphere. Kinetic studies under different atmospheres revealed that the thermal stability of Bi-2 2 1 2 phase was greatly enhanced under oxygen atmosphere.