1,198 research outputs found
New Sensor Technology Integration for safe and efficient e-Navigation
This paper discusses the relation of new sensor technology on bridge resource management as pertaining to the integration of new information sources and types for ship navigation in a future e-Navigation environment. An overview of several new technologies will be provided showing how systems and devices currently available in the commercial marketplace are being adapted and used to aid ship navigation planning and decision making. Examples include live Doppler radar useful for coastal navigation available from land-based sources through broadband Internet connections, imagery from unmanned aerial vehicles to aid in ice-navigation in, and forward-looking sonar for navigating in poorly charted, uncharted and other world regions where aids to navigation are not readily available. The use of such innovative methods are not yet covered in IMO Guidelines, as e.g., for Voyage Planning, the Procedures Manual of a shipâs Safety Management System or any other document to illustrate the adoption of such technology, but needs to be considered and investigated. However, the implications of introducing such new information sources in terms of bridge watchstander (Officer of the Watch - OOW) workload and training are discussed with respect to existing guidelines and regulations. Further illustration is provided in the context of how such new information sources may be integrated with existing resources to enhance overall navigation situational awareness. This includes the information itself as well as the means and methods used to interact with the OOW in terms of bridge displays, monitors and alarms. Selected specific details of research efforts currently underway will be provided in terms of forward-looking sonar integration into the bridge environment and navigation processes. This will include results obtained from experimental studies in the laboratory as well as on a suitably equipped research vessel test bed. A description of achievements accomplished to date will be provided in terms of tasks performed; the processes and procedures employed to acquire, manage and evaluate these tasks; preliminary results and outcomes achieved; and metrics used to measure these outcomes in terms of determining whether the research goals are achievable. Comparisons between expectations and actual results will be discussed, along with an analysis of risks encountered. Lessons learned are documented regarding errors in input, process, product and/or metrics
A Study of Selected Chemical and Biological Conditions of the Lower Trinity River and the Upper Trinity Bay
Concern over the effects of water development projects on coastal nurseries prompted the Department of Wildlife Science of Texas A&M University, with the cooperation of the UO So Bureau of Commercial Fisheries, Galveston, to undertake a study of a threatened nursery in the Galveston Bay System.
A long-range program for the development of the Trinity River Drainage Basin includes the construction of several multi-purpose reservoirs along the main river (Fickessen, 1965). Of immediate threat to Galveston Bay nurseries was the reservoir to be constructed at Wallisville, Texas (Trinity River Mile 3.9)0 The site is close to Trinity Bay and the dam will traverse the relatively wide deltaic region of the Trinity River (Figure 2).
The completed dam will serve as an effective barrier to salt water. Approximately 12,500 acres of marsh behind the dam will be come a freshwater conservation pool. The marsh area below the dam (8,200 acres) will also be modified through changes in the freshwater flow.
It is assumed that tile Wallisville Dam will be completed and that many of the conditions described here for the study area will be drastically changed.
The aim of this study was to gather data which would establish file role of the threatened marsh as a nursery for important marine and estuarine species It is recognized that these data will serve in planning and evaluating future water projects of this nature. Data reported here cover the period from March, 1966, through May, 1968. The study was limited to commercially important species with special emphasis given to the shrimps.
The Bureau of Commercial Fisheries had maintained collecting stations in trinity Bay and made several preliminary investigations in the area of the proposed Wallisville Reservoir, but the actual extent to which commercially important species were utilizing these threatened wetlands was unknown. This paper attempts to demonstrate the extent to which the marsh has been utilized by the white shrimp (Penaeus setiferus Linnaeus), the brown shrimp (Penaeus aztecus Ives), the blue crab (Callinectes sapidus Rathburl), and the Gulf menhaden (Brevoortia patronus Goode). Some of the information presented here may be pertinent to an understanding of the same species in other low salinity environments
Coordinating government and community support for community language teaching in Australia: Overview with special attention to New South Wales
An overview of formal government language-in-education planning for community languages (CLs) that has been undertaken in Australia and New South Wales is provided, moving from the more informal programmes provided in the 1980s to school-oriented programmes and training at the turn of the century. These programmes depend on community support; for many of the teachers from the communities, methodological training is needed to complement their language and cultural skills. At the same time, Commonwealth (Federal) and State support for CL programmes has improved their quality and provides students with opportunities to study CLs at the senior secondary matriculation level. The paper concludes with specific recommendations for greater recognition of CL schools and for greater attention to CL teacher preparation
Minimizing the stochasticity of halos in large-scale structure surveys
In recent work (Seljak, Hamaus and Desjacques 2009) it was found that
weighting central halo galaxies by halo mass can significantly suppress their
stochasticity relative to the dark matter, well below the Poisson model
expectation. In this paper we extend this study with the goal of finding the
optimal mass-dependent halo weighting and use -body simulations to perform a
general analysis of halo stochasticity and its dependence on halo mass. We
investigate the stochasticity matrix, defined as , where is the dark matter
overdensity in Fourier space, the halo overdensity of the -th
halo mass bin and the halo bias. In contrast to the Poisson model
predictions we detect nonvanishing correlations between different mass bins. We
also find the diagonal terms to be sub-Poissonian for the highest-mass halos.
The diagonalization of this matrix results in one large and one low eigenvalue,
with the remaining eigenvalues close to the Poisson prediction ,
where is the mean halo number density. The eigenmode with the lowest
eigenvalue contains most of the information and the corresponding eigenvector
provides an optimal weighting function to minimize the stochasticity between
halos and dark matter. We find this optimal weighting function to match linear
mass weighting at high masses, while at the low-mass end the weights approach a
constant whose value depends on the low-mass cut in the halo mass function.
Finally, we employ the halo model to derive the stochasticity matrix and the
scale-dependent bias from an analytical perspective. It is remarkably
successful in reproducing our numerical results and predicts that the
stochasticity between halos and the dark matter can be reduced further when
going to halo masses lower than we can resolve in current simulations.Comment: 17 pages, 14 figures, matched the published version in Phys. Rev. D
including one new figur
The SQM/COSMO filter: reliable native pose identification based on the quantum-mechanical description of proteinâligand interactions and implicit COSMO solvation
Current virtual screening tools are fast, but reliable scoring is elusive. Here, we present the "SQM/COSMO filter", a novel scoring function featuring a quantitative semiempirical quantum mechanical (SQM) description of all types of noncovalent interactions coupled with implicit COSMO solvation. We show unequivocally that it outperforms eight widely used scoring functions. The accuracy and chemical generality of the SQM/COSMO filter make it a perfect tool for late stages of virtual screening
Chronology of dune development in the White River Badlands, northern Great Plains, USA
Aeolian dune field chronologies provide important information on drought history on the Great Plains. The White River Badlands (WRB) dunes are located approximately 60 km north of the Nebraska Sand Hills (NSH), in the western section of the northern Great Plains. Clifftop dunes, sand sheets, and stabilized northwest-southeast trending parabolic dunes are found on upland mesas and buttes, locally called tables. The result of this study is a dune stabilization history determined from samples collected from stratigraphic exposures and dune crests. Thirty-seven OSL ages, from this and previous investigations, show three periods of dune activity: 1) ~21,000 years ago to 12,000 years ago (a), 2) ~9 to 6 ka, and 3) post-700 a. Stratigraphic exposures and low-relief dune forms preserve evidence of late Pleistocene and middle Holocene dune development, while high-relief dune crests preserve evidence of late Holocene dune development. Results of 12 OSL ages from the most recent dune activation event indicate that Medieval Climate Anomaly (MCA) droughts and Little Ice Age (LIA) droughts caused dune reactivation on the tables. Dune reactivation was accompanied by other drought-driven geomorphological responses in the WRB, including fluvial incision of the prairie and formation of sod tables. Regional significance of the MCA and LIA droughts is supported by similarities in the aeolian chronologies of the NSH at 700â600 a and some western Great Plains dune fields at 420â210 a. Aerial photographs of the WRB show little activity during the Dust Bowl droughts of the 1930s
The Slow Control System of the Atomic Beam Source at ANKE/COSY: An Industrial Approach Based on WinCC and S7 PLCs
Effects and Detectability of Quasi-Single Field Inflation in the Large-Scale Structure and Cosmic Microwave Background
Quasi-single field inflation predicts a peculiar momentum dependence in the
squeezed limit of the primordial bispectrum which smoothly interpolates between
the local and equilateral models. This dependence is directly related to the
mass of the isocurvatons in the theory which is determined by the
supersymmetry. Therefore, in the event of detection of a non-zero primordial
bispectrum, additional constraints on the parameter controlling the
momentum-dependence in the squeezed limit becomes an important question. We
explore the effects of these non-Gaussian initial conditions on large-scale
structure and the cosmic microwave background, with particular attention to the
galaxy power spectrum at large scales and scale-dependence corrections to
galaxy bias. We determine the simultaneous constraints on the two parameters
describing the QSF bispectrum that we can expect from upcoming large-scale
structure and cosmic microwave background observations. We find that for
relatively large values of the non-Gaussian amplitude parameters, but still
well within current uncertainties, galaxy power spectrum measurements will be
able to distinguish the QSF scenario from the predictions of the local model. A
CMB likelihood analysis, as well as Fisher matrix analysis, shows that there is
also a range of parameter values for which Planck data may be able distinguish
between QSF models and the related local and equilateral shapes. Given the
different observational weightings of the CMB and LSS results, degeneracies can
be significantly reduced in a joint analysis.Comment: 27 pages, 14 figure
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