2,348 research outputs found
Cartographic research in EREP program for small scale mapping
The author has identified the following significant results. Skylab photography is suitable for producing planimetric maps with graphical representation of landform at scales up to 1:100,000. It cannot supply all the detail necessary for maps at this scale, but it may be used to produce a sound framework which can be completed by detail from other sources. Its principal cartographic use is for original mapping of undeveloped areas of the world, but it would also be useful for the revision of existing maps and for monitoring extensive urban changes
Study of techniques and applications of satellite imagery to small scale mapping
There are no author-identified significant results in this report
On composite laminates with extensional anisotropy
The definite list of extensionally (membrane) anisotropic composite laminates with up to 21 plies is presented. The listings comprise of individual stacking sequences, which are characterized in terms of angle- and cross-ply sub-sequence relationships as well as the blend-ratio of
unbalanced angle-plies. Dimensionless parameters, including lamination parameters, are provided, from which the extensional and bending stiffness terms are readily calculated and an assessment of the bending stiffness efficiency made for angle- and cross-ply sub-sequences. Comparisons are made between the structural response of extensionally-anisotropic laminates and laminates with both extensional- and bending-anisotropy; Initial- and post-buckling responses are considered at the panel level together with the static response of a complete wing-box structure
Characterization of ply mixing rules for non-symmetric forms of fully orthotropic laminates
Stacking sequence listings are presented for fully orthotropic angle-ply
laminates, with up to 21 plies, together with rules for mixing these
sequences to form laminates containing any number of plies. The mixing
rules are demonstrated through an abridged set of sequences, which are
characterized in terms of angle- and cross-ply sub-sequence symmetries. The
abridged set of sequences is derived from a new definitive list that
supersedes previously published listings. Stacking sequences are presented
together with dimensionless parameters from which the bending stiffness
terms are readily calculated and an assessment of the bending stiffness
efficiency made for angle- and cross-ply sub-sequences. Expressions
relating the dimensionless parameters to the well-known lamination
parameters are also given, together with graphical representations of
feasible domains for all sub-sequence symmetries contained in the definitive
list. Feasible domains for extensionally isotropic and fully isotropic
laminates are also presented as important sub-sets of fully orthotropic
laminates. Finally, examples are given for tapered laminates with fully
orthotropic properties, derived from compatible sequences in the definite
list
Stacking sequences for extensionally isotropic, fully isotropic and quasi-homogeneous orthotropic laminates
Stacking sequence listings are presented for fully uncoupled Extensionally
Isotropic (EILs), Fully Isotropic (FILs) and Quasi-Homogeneous Orthotropic
(QHOLs) angle-ply Laminates, with up to 21 plies. All are sub-sets of a
definitive list of Fully Orthotropic Laminates (FOLs), containing generally
non-symmetric stacking sequences that are characterized in terms of angle-
and cross-ply sub-sequence symmetries. Dimensionless parameters are given
for each stacking sequence, from which the ABD matrix is readily derived.
Expressions relating these dimensionless parameters to the well-known
lamination parameters are also given, together with graphical
representations of the feasible domains for Pi/3 and Pi/4 EILs and angle-ply
QHOLs containing two and three ply orientations. The feasible domain for
Pi/3 FILs is represented graphically by a single point, whereas the domain
for angle-ply QHOLs containing four ply orientations is represented by a
single stacking sequence
Critical fluctuations in superconductors and the magnetic field penetration depth
The superconducting transition is studied within the one-loop renormalization
group in fixed dimension and at the critical point. A tricritical
behavior is found, and for , an attractive charged fixed
point, distinct from that of a neutral superfluid. The critical exponents of
the continuous transition are evaluated, and it is shown that the anomalous
dimension of the gauge field equals unity. This implies the proportionality of
the magnetic field penetration depth and the superconducting correlation length
below the transition. The penetration depth exponent is nonclassical. We argue
that it can not be extracted from the dual theory in a straightforward manner
since it is not renormalized by fluctuations of the dual field.Comment: 12 pages, LaTex, two figures available upon reques
Critical Phenomena with Linked Cluster Expansions in a Finite Volume
Linked cluster expansions are generalized from an infinite to a finite
volume. They are performed to 20th order in the expansion parameter to approach
the critical region from the symmetric phase. A new criterion is proposed to
distinguish 1st from 2nd order transitions within a finite size scaling
analysis. The criterion applies also to other methods for investigating the
phase structure such as Monte Carlo simulations. Our computational tools are
illustrated at the example of scalar O(N) models with four and six-point
couplings for and in three dimensions. It is shown how to localize
the tricritical line in these models. We indicate some further applications of
our methods to the electroweak transition as well as to models for
superconductivity.Comment: 36 pages, latex2e, 7 eps figures included, uuencoded, gzipped and
tarred tex file hdth9607.te
The development and validation of the Interpersonal Support in Physical Activity Consultations Observational Tool
This study describes the development and psychometric characteristics of an observational instrument that examines four aspects of interpersonal support (or lack of) provided during physical activity (PA) promotion consultations (i.e., Autonomy Support, Involvement, Structure and Interpersonal Control), as identified by Self-determination Theory (SDT). The reliability and validity of the Interpersonal Support in Physical Activity Consultations Observational Tool (ISPACOT) were examined within an exploratory randomised control trial. Recorded consultations (N = 42) conducted by qualified PA advisors (N = 14) at 13 leisure centres across the West Midlands (UK) were rated. Intra-class correlation coefficients (ICC) indicated moderate to high inter-rater reliability for overall interpersonal support (0.80), and the Autonomy Support (0.74), Involvement (0.73) and Structure (0.91) dimensions, but low reliability for Interpersonal Control (0.35). The advisors, who conducted PA promotion consultations that were rated as low in their interpersonally supportive features, were perceived by their clients as being less supportive (F(1,10) = 5.0, p <.05). Ratings on the ISPACOT differentiated advisors who were trained in SDT principles and those who were not. Overall, the findings provided preliminary evidence for the reliability and convergent validity of the ISPACOT
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Scoping education needs and provision for walk-in-centres in North East London
Factor copula models for item response data
Factor or conditional independence models based on copulas are proposed for multivariate discrete data such as item responses. The factor copula models have interpretations of latent maxima/minima (in comparison with latent means) and can lead to more probability in the joint upper or lower tail compared with factor models based on the discretized multivariate normal distribution (or multidimensional normal ogive model). Details on maximum likelihood estimation of parameters for the factor copula model are given, as well as analysis of the behavior of the log-likelihood. Our general methodology is illustrated with several item response data sets, and it is shown that there is a substantial improvement on existing models both conceptually and in fit to data
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