1,173 research outputs found
Backup flight control system functional evaluator software manual
The software for the Backup Flight Control System Functional Evaluator (BFCSFE) on a Data General Corporation Nova 1200 computer consists of three programs: the ground support program, the operational flight program (OFP), and the ground pulse code modulation (PCM) program. The Nova OFP software is structurally as close as possible to the AP101 code; therefore, this document highlights and describes only those areas of the Nova OFP that are significantly different from the AP101. Since the Ground Support Program was developed to meet BFCSFE requirements and differs considerably from the AP101 code, it is described in detail
THE POTENTIAL USE OF POLLUTION INSURANCE AS ENVIRONMENTAL POLICY: AN EMPIRICAL ANALYSIS
Market-based environmental policies have been forwarded as alternatives to current pollution control policies. Implementation of the "polluter pays" principle and governmental enforcement of pollution clean-up have led to astronomical environmental liabilities and clean-up costs, which may threaten the survival of many productive ventures, unless producers can spread pollution risk through insurance. An emission constrained target MOTAD LP (TMLP) model showed that pollution insurance for irrigation farmers can be a feasible and efficient solution to agricultural salinization problems in the Loskop Valley, and fairly low salinity standards with pollution insurance will still be reconcilable with profitable farming. Pollution insurance appears to hold promise for applying the "polluter pays" principles also to non-point pollution. Site specific studies are needed for pollution policy, and more research is needed on pollution standards.Environmental Economics and Policy,
Comparison of glacial and interglacial conditions between the polar and the subpolar North Atlantic Region over the past five climate cycles
A multiparameter-based interpretation of sediment records from the northeast Atlantic and the western Nordic seas suggests that during the last 500,000 years only in marine isotopes stage (MIS) 11, 5e, and 1 were there somewhat comparable interglacial boundary conditions in both regions, i.e., strongly reduced occurrence of iceberg-rafted debris (IRD) and high carbonate bioproductivity. Although the northeast Atlantic experienced such conditions during all peak interglaciations, with the exception of MIS 7, planktic foraminiferal δ18O from this region would still indicate that significantly colder sea surface temperatures (SST) prevailed during MIS 11 than during MIS 9, 5e, and 1. This assumption is corroborated by a continuous input of IRD into the western Nordic seas during MIS 11, implying a much steeper SST gradient between the polar and subpolar region and an overall reduced thermohaline activity in the polar latitudes. The iceberg proxy also reveals that maximum IRD discharge always happened during the final phase of glaciation and into early deglaciation (terminations). As these IRD records from the two regions are characterized by a high time coherency, it is concluded that short-term variability is a persistent feature of the glacial climate system
Glacial-interglacial records of the reflectance of sediments from the Norwegian-Greenland-Iceland Sea (Nordic seas)
 The reflectance of sediments (gray level) were measured on 11 sediment cores from the Norwegian–Greenland–Iceland Sea (Nordic seas). The analyzed time interval covers the past five glacial–interglacial cycles. Although the results demonstrate that the gray-level method has a potential for stratigraphic purposes, it is indicated that gray-level changes in the Nordic seas are not necessarily driven by variations in the content of biogenic calcite. A detailed comparison of gray-level values with contents of total CaCO3 (carbonate) and total organic carbon (TOC) reveals no overall causal link between these proxies. However, specific glacial core sections with layers containing organic-rich sediment clasts as a consequence of iceberg-rafting seem to correlate well with law gray-level values. Of those cores which show relatively high and comparable carbonate values in the last three main interglacial intervals (stages 11, 5.5, and 1), stage 11 is always marked by the highest gray-level values. A close inspection of the surface structure of the foraminiferal tests as well as the conduction of reflectance measurements on these tests leads to the conclusion that enhanced carbonate corrosion occurred during stage 11. The test corrosion not only affected the reflectance of the tests by making them appear whiter, it also seems responsible for the comparatively high gray-level values of the total sediment in stage 11. In contrast, the relatively low gray-level values found in stages 5.5, and 1 are not associated with enhanced test corrosion. This observation implies that variable degrees of carbonate corrosion can have a profound effect on total sediment reflectance
The role of controllability in optimizing quantum dynamics
This paper discusses the important role of controllability played on the
complexity of optimizing quantum mechanical control systems. The study is based
on a topology analysis of the corresponding quantum control landscape, which is
referred to as the optimization objective as a functional of control fields. We
find that the degree of controllability is closely relevant with the ruggedness
of the landscape, which determines the search efficiency for global optima.
This effect is demonstrated via the gate fidelity control landscape of a system
whose controllability is restricted on a SU(2) dynamic symmetry group. We show
that multiple local false traps (i.e., non-global suboptima) exist even if the
target gate is realizable and that the number of these traps is increased by
the loss of controllability, while the controllable systems are always devoid
of false traps.Comment: 13 pages, 3 figure
The landscape of quantum transitions driven by single-qubit unitary transformations with implications for entanglement
This paper considers the control landscape of quantum transitions in
multi-qubit systems driven by unitary transformations with single-qubit
interaction terms. The two-qubit case is fully analyzed to reveal the features
of the landscape including the nature of the absolute maximum and minimum, the
saddle points and the absence of traps. The results permit calculating the
Schmidt state starting from an arbitrary two-qubit state following the local
gradient flow. The analysis of multi-qubit systems is more challenging, but the
generalized Schmidt states may also be located by following the local gradient
flow. Finally, we show the relation between the generalized Schmidt states and
the entanglement measure based on the Bures distance
Contrasting ocean changes between the subpolar and polar North Atlantic during the past 135 ka
Variations in the poleward-directed Atlantic heat transfer was investigated over the past 135 ka with special emphasis on the last and present interglacial climate development (Eemian and Holocene). Both interglacials exhibited very similar climatic oscillations during each preceding glacial terminations (deglacial TI and TII). Like TI, also TII has pronounced cold–warm–cold changes akin to events such as H1, Bølling/Allerød, and the Younger Dryas. But unlike TI, the cold events in TII were associated with intermittent southerly invasions of an Atlantic faunal component which underscores quite a different water mass evolution in the Nordic Seas. Within the Eemian interglaciation proper, peak warming intervals were antiphased between the Nordic Seas and North Atlantic. Moreover, inferred temperatures for the Nordic Seas were generally colder in the Eemian than in the Holocene, and vice versa for the North Atlantic. A reduced intensity of Atlantic Ocean heat transfer to the Arctic therefore characterized the Eemian, requiring a reassessment of the actual role of the ocean–atmosphere system behind interglacial, but also, glacial climate changes.
Key Points
- Reduced AMOC during the Eemian
- BA/YD-type warming/cooling in Termination 1 and 2
- Comparison of glacial inceptions reveals present climate statu
Relative "-Numerical Ranges for Applications in Quantum Control and Quantum Information
Motivated by applications in quantum information and quantum control, a new
type of "-numerical range, the relative "-numerical range denoted
, is introduced. It arises upon replacing the unitary group U(N) in
the definition of the classical "-numerical range by any of its compact and
connected subgroups .
The geometric properties of the relative "-numerical range are analysed in
detail. Counterexamples prove its geometry is more intricate than in the
classical case: e.g. is neither star-shaped nor simply-connected.
Yet, a well-known result on the rotational symmetry of the classical
"-numerical range extends to , as shown by a new approach based on
Lie theory. Furthermore, we concentrate on the subgroup , i.e. the -fold tensor product of SU(2),
which is of particular interest in applications. In this case, sufficient
conditions are derived for being a circular disc centered at
origin of the complex plane. Finally, the previous results are illustrated in
detail for .Comment: accompanying paper to math-ph/070103
A paleoclimatic evaluation of marine oxygen isotope stage 11 in the high-northern Atlantic (Nordic seas)
A sediment core from the high latitude of the Northern Atlantic (Nordic seas) was intensively studied by means of biogeochemical, sedimentological, and micropaleontological methods. The proxy records of interglacial marine oxygen isotope stage (MIS) 11 are directly compared with records from the Holocene (MIS 1), revealing that many features of MIS 11 are rather atypical for an interglaciation at these latitudes.
Full-interglacial conditions without deposition of ice-rafted debris existed in MIS 11 for about 10 kyr (∼398–408 ka). This time is marked by the lightest d18O values in benthic foraminifera, indicating a small global ice volume, and by the appearance of subpolar planktic foraminifera, indicating a northward advection of Atlantic surface water. A comparison with MIS 1, using the same proxies, implies that surface temperatures were lower and global ice volume was larger during MIS 11. A comparative study of the ratio between planktic and benthic foraminifera also reveals strong differences among the two intervals. These data imply that the coupling between surface and bottom bioproductivity, i.e., the vertical transportation of the amount of fresh organic matter, was different in MIS 11. This is corroborated by a benthic fauna in MIS 11, which contains no epifaunally-living species. Despite comparable values in carbonate content (%), reflectance analyses of the total sediment (greylevel) show much higher values for MIS 11 than for MIS 1. These high values are attributed to increased corrosion of foraminiferal tests, directly affecting the sediment greylevel. The reason for this enhanced carbonate corrosion in MIS 11 remains speculative, but may be linked to the global carbon cycle
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