261 research outputs found
Smart Knowledge Capture for Developing Adaptive Management Systems
In this paper we describe how a welldesigned Spatial Decision Support System (SDSS) may facilitate initial (immediate) decision making, while establishing a robust foundation and framework for improving effectiveness over time as new data and knowledge becomes available. \u27Smart Knowledge Capture\u27 is a set of methods for rapidly developing a strong SDSS for adaptive management. We review some of the MIS tools used in Smart Knowledge Capture: multicriteria decision analysis (MCDA) tools, online surveys, online knowledge portals, ontology systems, and describe the architecture of an SDSS that stores and utilizes this knowledge. We illustrate these concepts using our recent work supporting the development of a revised desert tortoise recovery plan
Correlation effects in ionic crystals: I. The cohesive energy of MgO
High-level quantum-chemical calculations, using the coupled-cluster approach
and extended one-particle basis sets, have been performed for (Mg2+)n (O2-)m
clusters embedded in a Madelung potential. The results of these calculations
are used for setting up an incremental expansion for the correlation energy of
bulk MgO. This way, 96% of the experimental cohesive energy of the MgO crystal
is recovered. It is shown that only 60% of the correlation contribution to the
cohesive energy is of intra-ionic origin, the remaining part being caused by
van der Waals-like inter-ionic excitations.Comment: LaTeX, 20 pages, no figure
Analyzing and enhancing OSKI for sparse matrix-vector multiplication
Sparse matrix-vector multiplication (SpMxV) is a kernel operation widely used
in iterative linear solvers. The same sparse matrix is multiplied by a dense
vector repeatedly in these solvers. Matrices with irregular sparsity patterns
make it difficult to utilize cache locality effectively in SpMxV computations.
In this work, we investigate single- and multiple-SpMxV frameworks for
exploiting cache locality in SpMxV computations. For the single-SpMxV
framework, we propose two cache-size-aware top-down row/column-reordering
methods based on 1D and 2D sparse matrix partitioning by utilizing the
column-net and enhancing the row-column-net hypergraph models of sparse
matrices. The multiple-SpMxV framework depends on splitting a given matrix into
a sum of multiple nonzero-disjoint matrices so that the SpMxV operation is
performed as a sequence of multiple input- and output-dependent SpMxV
operations. For an effective matrix splitting required in this framework, we
propose a cache-size-aware top-down approach based on 2D sparse matrix
partitioning by utilizing the row-column-net hypergraph model. The primary
objective in all of the three methods is to maximize the exploitation of
temporal locality. We evaluate the validity of our models and methods on a wide
range of sparse matrices by performing actual runs through using OSKI.
Experimental results show that proposed methods and models outperform
state-of-the-art schemes.Comment: arXiv admin note: substantial text overlap with arXiv:1202.385
The MothersBabies Study, an Australian Prospective Cohort Study Analyzing the Microbiome in the Preconception and Perinatal Period to Determine Risk of Adverse Pregnancy, Postpartum, and Child-Related Health Outcomes: Study Protocol
The microbiome has emerged as a key determinant of human health and reproduction, with recent evidence suggesting a dysbiotic microbiome is implicated in adverse perinatal health outcomes. The existing research has been limited by the sample collection and timing, cohort design, sample design, and lack of data on the preconception microbiome. This prospective, longitudinal cohort study will recruit 2000 Australian women, in order to fully explore the role of the microbiome in the development of adverse perinatal outcomes. Participants are enrolled for a maximum of 7 years, from 1 year preconception, through to 5 years postpartum. Assessment occurs every three months until pregnancy occurs, then during Trimester 1 (5 + 0â12 + 6 weeks gestation), Trimester 2 (20 + 0â24 + 6 weeks gestation), Trimester 3 (32 + 0â36 + 6 weeks gestation), and postpartum at 1 week, 2 months, 6 months, and then annually from 1 to 5 years. At each assessment, maternal participants self-collect oral, skin, vaginal, urine, and stool samples. Oral, skin, urine, and stool samples will be collected from children. Blood samples will be obtained from maternal participants who can access a study collection center. The measurements taken will include anthropometric, blood pressure, heart rate, and serum hormonal and metabolic parameters. Validated self-report questionnaires will be administered to assess diet, physical activity, mental health, and child developmental milestones. Medications, medical, surgical, obstetric history, the impact of COVID-19, living environments, and pregnancy and child health outcomes will be recorded. Multiomic bioinformatic and statistical analyses will assess the association between participants who developed high-risk and low-risk pregnancies, adverse postnatal conditions, and/or childhood disease, and their microbiome for the different sample types
Raman scattering in C_{60} and C_{48}N_{12} aza-fullerene: First-principles study
We carry out large scale {\sl ab initio} calculations of Raman scattering
activities and Raman-active frequencies (RAFs) in
aza-fullerene. The results are compared with those of .
Twenty-nine non-degenerate polarized and 29 doubly-degenerate unpolarized RAFs
are predicted for . The RAF of the strongest Raman
signal in the low- and high-frequency regions and the lowest and highest RAFs
for are almost the same as those of .
The study of reveals the importance of electron correlations and
the choice of basis sets in the {\sl ab initio} calculations. Our best
calculated results for with the B3LYP hybrid density functional
theory are in excellent agreement with experiment and demonstrate the desirable
efficiency and accuracy of this theory for obtaining quantitative information
on the vibrational properties of these molecules.Comment: submitted to Phys.Rev.
Electron affinities of the first- and second- row atoms: benchmark ab initio and density functional calculations
A benchmark ab initio and density functional (DFT) study has been carried out
on the electron affinities of the first- and second-row atoms. The ab initio
study involves basis sets of and quality, extrapolations to
the 1-particle basis set limit, and a combination of the CCSD(T), CCSDT, and
full CI electron correlation methods. Scalar relativistic and spin-orbit
coupling effects were taken into account. On average, the best ab initio
results agree to better than 0.001 eV with the most recent experimental
results. Correcting for imperfections in the CCSD(T) method improves the mean
absolute error by an order of magnitude, while for accurate results on the
second-row atoms inclusion of relativistic corrections is essential. The latter
are significantly overestimated at the SCF level; for accurate spin-orbit
splitting constants of second-row atoms inclusion of (2s,2p) correlation is
essential. In the DFT calculations it is found that results for the 1st-row
atoms are very sensitive to the exchange functional, while those for second-row
atoms are rather more sensitive to the correlation functional. While the LYP
correlation functional works best for first-row atoms, its PW91 counterpart
appears to be preferable for second-row atoms. Among ``pure DFT'' (nonhybrid)
functionals, G96PW91 (Gill 1996 exchange combined with Perdew-Wang 1991
correlation) puts in the best overall performance. The best results overall are
obtained with the 1-parameter hybrid modified Perdew-Wang (mPW1) exchange
functionals of Adamo and Barone [J. Chem. Phys. {\bf 108}, 664 (1998)], with
mPW1LYP yielding the best results for first-row, and mPW1PW91 for second-row
atoms. Indications exist that a hybrid of the type mPW1LYP +
mPW1PW91 yields better results than either of the constituent functionals.Comment: Phys. Rev. A, in press (revised version, review of issues concerning
DFT and electron affinities added
A mathematical and computational review of Hartree-Fock SCF methods in Quantum Chemistry
We present here a review of the fundamental topics of Hartree-Fock theory in
Quantum Chemistry. From the molecular Hamiltonian, using and discussing the
Born-Oppenheimer approximation, we arrive to the Hartree and Hartree-Fock
equations for the electronic problem. Special emphasis is placed in the most
relevant mathematical aspects of the theoretical derivation of the final
equations, as well as in the results regarding the existence and uniqueness of
their solutions. All Hartree-Fock versions with different spin restrictions are
systematically extracted from the general case, thus providing a unifying
framework. Then, the discretization of the one-electron orbitals space is
reviewed and the Roothaan-Hall formalism introduced. This leads to a exposition
of the basic underlying concepts related to the construction and selection of
Gaussian basis sets, focusing in algorithmic efficiency issues. Finally, we
close the review with a section in which the most relevant modern developments
(specially those related to the design of linear-scaling methods) are commented
and linked to the issues discussed. The whole work is intentionally
introductory and rather self-contained, so that it may be useful for non
experts that aim to use quantum chemical methods in interdisciplinary
applications. Moreover, much material that is found scattered in the literature
has been put together here to facilitate comprehension and to serve as a handy
reference.Comment: 64 pages, 3 figures, tMPH2e.cls style file, doublesp, mathbbol and
subeqn package
Anthropometric, biochemical, dietary, morbidity and well-being assessments in women and children in Indonesia, India and Senegal : A UKRI GCRF Action Against Stunting Hub protocol paper
HD-K and EF were responsible for the overall design, training and overseeing implementation of the research. UF, MKH, BK, BF, RM, RPullakhandam, RPalika, TD, SFR, SD, RPradeilles, SA, AW, JPW, PH and CH were involved in its design. UF, MKH, BK, BF, DY, DS, NLZ, TCA, RM, RPullakhandam, RPalika, TD, SFR, SKB KS, DPP, DY, SD, PL-S, BD, PM, SF, ID, AD, TDVI, FT, AD, SS, BMK and DTT implemented the research. HD-K and EF wrote the manuscript. All authors read, provided comments on and approved the final version of the manuscript.Peer reviewe
- âŠ