1,610 research outputs found
Optimal Unemployment Insurance with Monitoring and Sanctions
This paper analyzes the design of optimal unemployment insurance in a search equilibrium framework where search effort among the unemployed is not perfectly observable.We examine to what extent the optimal policy involves monitoring of search effort and benefit sanctions if observed search is deemed insuficient.We find that introducing monitoring and sanctions represents a welfare improvement for reasonable estimates of monitoring costs; this conclusion holds both relative to a system featuring indefinite payments of benefits and a system with a time limit on unemployment benefit receipt.The optimal sanction rates implied by our calibrated model are much higher than the sanction rates typically observed in European labor markets.unemployment insurance;job search
Gamma-Ray Bursts from Primordial Quark Objects in Space
We investigate the possibility that gamma-ray bursts originate in a
concentric spherical shell with a given average redshift and find that this is
indeed compatible with the data from the third BATSE (3B) catalog. It is also
shown that there is enough freedom in the choice of unknown burst properties to
allow even for extremely large distances to the majority of bursts. Therefore,
we speculate about an early, and very energetic, origin of bursts, and suggest
that they come from phase transitions in massive objects of pure quark matter,
left over from the Big Bang.Comment: 11 pages, Latex, 3 postscript figures, to be publ in the Proc of the
Joint Meeting of the Networks 'The Fundamental Structure of Matter' and
'Tests of the Electroweak Symmetry Breaking', Ouranoupolis, Greece, May 199
ShapeFit and ShapeKick for Robust, Scalable Structure from Motion
We introduce a new method for location recovery from pair-wise directions
that leverages an efficient convex program that comes with exact recovery
guarantees, even in the presence of adversarial outliers. When pairwise
directions represent scaled relative positions between pairs of views
(estimated for instance with epipolar geometry) our method can be used for
location recovery, that is the determination of relative pose up to a single
unknown scale. For this task, our method yields performance comparable to the
state-of-the-art with an order of magnitude speed-up. Our proposed numerical
framework is flexible in that it accommodates other approaches to location
recovery and can be used to speed up other methods. These properties are
demonstrated by extensively testing against state-of-the-art methods for
location recovery on 13 large, irregular collections of images of real scenes
in addition to simulated data with ground truth
Use of pepper spray in policing : retrospective study of situational characteristics and implications for violent situations
Pepper spray (OC) is a policing tool aimed to prevent or stop aggressive behavior by quickly and temporarily incapacitate without injuring. To date, few studies have investigated OCās operational usefulness and limitations. OC reduced violent behavior in 93% of the 936 incidents investigated. However, the operative range was often <2 m and it took between 3 and 5 s of spraying before obtaining effect, partly owing to the difficulties of hitting a small, sometimes erratically moving target. Collateral hits were noted in 24% of the incidents, whereof 90% were other officers. Noteworthy, in 21% of incidents officers put themselves at large personal risk by using OC at close range against people armed with lethal weapons. Hence, OC emerges as a suitable tool for handling low threat situations but lacks key traits to ensure safe and efficient policing of high threat situations, e.g., handling armed assailants
Optimal Unemployment Insurance with Monitoring and Sanctions
This paper analyzes the design of optimal unemployment insurance in a search equilibrium framework where search effort among the unemployed is not perfectly observable.We examine to what extent the optimal policy involves monitoring of search effort and benefit sanctions if observed search is deemed insuficient.We find that introducing monitoring and sanctions represents a welfare improvement for reasonable estimates of monitoring costs; this conclusion holds both relative to a system featuring indefinite payments of benefits and a system with a time limit on unemployment benefit receipt.The optimal sanction rates implied by our calibrated model are much higher than the sanction rates typically observed in European labor markets
The Chandrasekhar limit for quark stars
The Chandrasekhar limit for quark stars is evaluated from simple energy
balance relations, as proposed by Landau for white dwarfs or neutron stars. It
has been found that the limit for quark stars depends on, in addition to the
fundamental constants, the Bag constant.Comment: LateX fil
The Solute Carrier Families Have a Remarkably Long Evolutionary History with the Majority of the Human Families Present before Divergence of Bilaterian Species
The Solute Carriers (SLCs) are membrane proteins that regulate transport of many types of substances over the cell membrane. The SLCs are found in at least 46 gene families in the human genome. Here, we performed the first evolutionary analysis of the entire SLC family based on whole genome sequences. We systematically mined and analyzed the genomes of 17 species to identify SLC genes. In all, we identified 4,813 SLC sequences in these genomes, and we delineated the evolutionary history of each of the subgroups. Moreover, we also identified ten new human sequences not previously classified as SLCs, which most likely belong to the SLC family. We found that 43 of the 46 SLC families found in Homo sapiens were also found in Caenorhabditis elegans, whereas 42 of them were also found in insects. Mammals have a higher number of SLC genes in most families, perhaps reflecting important roles for these in central nervous system functions. This study provides a systematic analysis of the evolutionary history of the SLC families in Eukaryotes showing that the SLC superfamily is ancient with multiple branches that were present before early divergence of Bilateria. The results provide foundation for overall classification of SLC genes and are valuable for annotation and prediction of substrates for the many SLCs that have not been tested in experimental transport assays
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