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21.
Pattern Analysis and Applications - A feature based on a single modality such as color or texture is not sufficient to investigate the appearance variation across multiple images. In this paper, a... 相似文献
22.
Wireless Personal Communications - This work investigates the effectiveness of wavelet packets in dynamic secret key generation (DSKG) for physical layer security (PLS). Preprocessing channel... 相似文献
23.
Rory Coulter 《Housing Studies》2018,33(2):201-223
AbstractScholars and policy-makers are concerned that young adults’ housing opportunities are becoming more dependent on their family background. This could hinder social mobility and exacerbate inequality. Using data from three cohorts of young people drawn from the Office for National Statistics Longitudinal Study of England and Wales, this study examines how parental attributes in childhood are linked to young adults’ housing outcomes two decades later. The results show that young adults’ housing outcomes have changed considerably over time and are persistently stratified by parental class and tenure in ways that vary by gender. Housing outcomes have become somewhat more polarised by parental tenure over time as the children of renters became relatively less likely to enter homeownership and more likely to rent privately. This suggests that renters became an increasingly ‘marginalised minority’ in the late twentieth century, with consequences for their children’s housing careers and future social inequality. 相似文献
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The State Performance Plan (SPP) developed under the 2004 reauthorization of the Individuals with Disabilities Education Act (IDEA 2004, Public Law 108-446) requires states to collect data and report on the impact of early intervention services on three key outcomes for participating families. The NCSEAM Impact on Family Scale (NIFS) and the NCSEAM Family Centered Services Scale (NFCSS) were developed to provide states with a means to address this new reporting requirement and to collect additional data that would inform program improvement efforts. Items suggested by stakeholder groups were piloted with a nationally representative sample of parents of children with developmental delays or disabilities ages birth to three participating in early intervention services in eight states. The 28-item NIFS had measurement reliabilities ranging from .93-.96 in a sample of 1,750; measurement reliabilities for the 135-item NFCSS ranged from .94 to .97 in a sample of 1,755 respondents. A 29-item version of the NFCSS had measurement reliabilities ranging from .87 to .92. Using data from the pilot study, stakeholders established a recommended performance standard, set at a meaningful point in the NIFS item hierarchy, for each of the three established outcome areas. 相似文献
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Indicator 8 of the State Performance Plan (SPP), developed under the 2004 reauthorization of the Individuals with Disabilities Education Act (IDEA 2004, Public Law 108-446) requires states to collect data and report findings related to schools' facilitation of parent involvement. The Schools' Efforts to Partner with Parents Scale (SEPPS) was developed to provide states with a means to address this new reporting requirement. Items suggested by stakeholder groups were piloted with a nationally representative sample of 2,634 parents of students with disabilities ages 5-21 in six states. Rasch scaling was used to calibrate a meaningful and invariant item hierarchy. The 78 calibrated items had measurement reliabilities ranging from .94-.97. Using data from the pilot study, stakeholders established a recommended performance standard set at a meaningful point in the item hierarchy. Implications of the findings are discussed in relation to the need for rigorous metrics within state accountability systems. 相似文献
28.
Dr. Zsofia Lengyel-Zhand Dr. Liam R. Marshall Maximilian Jung Megha Jayachandran Dr. Min-Chul Kim Austin Kriews Prof. Dr. Olga V. Makhlynets Dr. H. Christopher Fry Prof. Dr. Armin Geyer Prof. Dr. Ivan V. Korendovych 《Chembiochem : a European journal of chemical biology》2021,22(3):585-591
The self-assembly of short peptides into catalytic amyloid-like nanomaterials has proven to be a powerful tool in both understanding the evolution of early proteins and identifying new catalysts for practically useful chemical reactions. Here we demonstrate that both parallel and antiparallel arrangements of β-sheets can accommodate metal ions in catalytically productive coordination environments. Moreover, synergistic relationships, identified in catalytic amyloid mixtures, can be captured in macrocyclic and sheet-loop-sheet species, that offer faster rates of assembly and provide more complex asymmetric arrangements of functional groups, thus paving the way for future designs of amyloid-like catalytic proteins. Our findings show how initial catalytic activity in amyloid assemblies can be propagated and improved in more-complex molecules, providing another link in a complex evolutionary chain between short, potentially abiotically produced peptides and modern-day enzymes. 相似文献
29.
CO2 is strongly adsorbed on Li/MgO as a surface carbonate and desorbs concomitantly with Li with an activation energy of desorption of 210 kJ/mol. The C2 product is strongly influenced by the presence of CO2,0.5 Torr being sufficient to substantially lower the rate of C2 production and to establish an activation energy for reaction of 210 kJ/mol. In the absence of CO2, the activation energy of C2 production falls to 105 kJ/mol. 相似文献
30.
P. Arendt N. Elliott R. Dye K. Hubbard M. Maley J. Martin Y. Coulter B. Bennett 《Journal of Electronic Materials》1992,21(5):499-501
A multi-step process is used to fabricate Tl2Ba2Ca1Cu2O8 films on (100) LaA103 substrates. Submicron thick precursor films of Ba-Ca-Cu-O are rf magnetron sputter deposited from a single target. Film stoichiometry
is measured by ion beam backscattering spectroscopy. Deficiencies of the alkaline earths that are found in the precursor films
are then compensated for by the addition of appropriate CaF2 and/or BaF2 films onto the surface of the precursor film. Post deposition annealing of the films is then done in an atmosphere of thallium
oxide and oxygen in order to form the superconducting phases. The annealed films are examined using x-ray diffraction (XRD),
an ac inductance technique, and critical current in an external magnetic field. XRD shows the c-axis length of the superconducting
phase to increase as the overall film stoichiometry approaches 2212. The transition widths measured by inductive coupling
weakly correlate with 77 K critical current measurements. Our best critical current results are 1.5*106 amps/ cm2 for a film measured at 4 K in an 8 T magnetic field (parallel to the films' c-axis). 相似文献