46,106 research outputs found
Self-forming shim or gasket for mounting heavy equipment
Soft, cross-serrated aluminum shims are used as mating gaskets between uneven surfaces. Under pressure, the aluminum flows to conform with surface irregularities, forming a plane of uniform bearing
Does the WTO Matter? A Non-parametric view
WTO, Trade, Foreign Direct Investment, and Patenting
Integration of SAR and DEM data: Geometrical considerations
General principles for integrating data from different sources are derived from the experience of registration of SAR images with digital elevation models (DEM) data. The integration consists of establishing geometrical relations between the data sets that allow us to accumulate information from both data sets for any given object point (e.g., elevation, slope, backscatter of ground cover, etc.). Since the geometries of the two data are completely different they cannot be compared on a pixel by pixel basis. The presented approach detects instances of higher level features in both data sets independently and performs the matching at the high level. Besides the efficiency of this general strategy it further allows the integration of additional knowledge sources: world knowledge and sensor characteristics are also useful sources of information. The SAR features layover and shadow can be detected easily in SAR images. An analytical method to find such regions also in a DEM needs in addition the parameters of the flight path of the SAR sensor and the range projection model. The generation of the SAR layover and shadow maps is summarized and new extensions to this method are proposed
Contains and Inside relationships within combinatorial Pyramids
Irregular pyramids are made of a stack of successively reduced graphs
embedded in the plane. Such pyramids are used within the segmentation framework
to encode a hierarchy of partitions. The different graph models used within the
irregular pyramid framework encode different types of relationships between
regions. This paper compares different graph models used within the irregular
pyramid framework according to a set of relationships between regions. We also
define a new algorithm based on a pyramid of combinatorial maps which allows to
determine if one region contains the other using only local calculus.Comment: 35 page
Rural People, Rural Places: The Hidden Costs of Hurricane Katrina
This brief shows how the characteristics of rural Gulf Coast families place them at higher risks during natural disasters and make them far less able to recover from such calamities. Although few realize it, nonmetro residents represented the majority (55%) of the population affected by Hurricane Katrina in Mississippi. They also constituted 17% of the people living in Alabama's disaster-stricken area, and about 12% of the affected population in Louisiana. These are not inconsequential numbers; they represent thousands of inhabitants living in small communities dotting the tri-state region. This Rural Realities brief draws much needed attention to nonmetro areas affected by Hurricane Katrina and outlines the key features of the rural people and places that have been impacted by this major disaster. Most important, it offers a series of policy recommendations that can assist in rebuilding the region's nonmetro counties and parishes. The hope is that these policy ideas can offer a meaningful set of strategies for lessening the future vulnerability of rural areas within and outside this region of the country. This brief is from Rural Realities; Volume 1, Issue 2. Rural Realities is published by the Rural Sociological Society. It is a peer-reviewed, web-based series that is published four times a year. Each issue is devoted to a single topic
Arsenic contamination in groundwater : some analytical considerations
For countries such as Bangladesh with a significant groundwater arsenic problem, there is an urgent need for the arsenic-contaminated wells to be identified as soon as possible and for appropriate action to be taken. This will involve the testing of a large number of wells, potentially up to 11 million in Bangladesh alone. Field-test kits offer the only practical way forward in the timescale required. The classic field method for detecting arsenic (the âGutzeitâ method) is based on the reaction of arsine gas with mercuric bromide and remains the best practical approach. It can in principle achieve a detection limit of about 10 ÎŒg lâ1 by visual comparison of the coloured stain against a colour calibration chart. A more objective result can be achieved when the colour is measured by an electronic instrument. Attention has to be paid to interferences mainly from hydrogen sulfide. Due to analytical errors, both from the field-test kits and from laboratory analysis, some misclassification of wells is inevitable, even under ideal conditions. The extent of misclassification depends on the magnitude of the errors of analysis and the frequency distribution of arsenic observed, but is in principle predictable before an extensive survey is undertaken. For a country with an arsenic distribution similar to that of Bangladesh, providing care is taken to avoid sources of bias during testing, modern field-test kits should be able to reduce this misclassification to under 5% overall
The Patenting Behavior of Academic Founders
This study explores why academic entrepreneurs patent their inventions before and after creating a firm. Drawing on start-up data combined with patent data, we specifically examine the impact of five, relatively under-researched factors (scientific field, pace of technological development, technological uncertainty, entrepreneurial orientation, and patent effectiveness. The study shows that some scientific fields, technological uncertainty, and patent effectiveness are positively related to patent propensity, both before and after founding. The effects of pace of technological development and entrepreneurial orientation were timespecific. Our study suggests that patenting by academic entrepreneurs is driven by special rationales and that prior research on full-time scientists and established firms does not necessarily generalize to them. We discuss the implications of our findings both in terms of contribution to the current literature and technology transfer policies. --academic patenting
Unsolvability Cores in Classification Problems
Classification problems have been introduced by M. Ziegler as a
generalization of promise problems. In this paper we are concerned with
solvability and unsolvability questions with respect to a given set or language
family, especially with cores of unsolvability. We generalize the results about
unsolvability cores in promise problems to classification problems. Our main
results are a characterization of unsolvability cores via cohesiveness and
existence theorems for such cores in unsolvable classification problems. In
contrast to promise problems we have to strengthen the conditions to assert the
existence of such cores. In general unsolvable classification problems with
more than two components exist, which possess no cores, even if the set family
under consideration satisfies the assumptions which are necessary to prove the
existence of cores in unsolvable promise problems. But, if one of the
components is fixed we can use the results on unsolvability cores in promise
problems, to assert the existence of such cores in general. In this case we
speak of conditional classification problems and conditional cores. The
existence of conditional cores can be related to complexity cores. Using this
connection we can prove for language families, that conditional cores with
recursive components exist, provided that this family admits an uniform
solution for the word problem
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