Position Estimating in Peer-to-Peer Networks

We present two algorithms for indoor positioning estimation in peer-to-peer networks. The setup is a network of two types of devices: reference devices with a known location and blindfolded devices that can determine distances to reference devices and each other. From this information the blindfolded devices try to estimate their positions. A typical scenario is navigation inside a shopping mall where devices in the parking lot can make contact with GPS satellites, whereas devices inside the building make contact with each other, devices on the parking lot, and devices fixed to the building. The devices can measure their in-between distances, with some measurement error, and exchange positioning information. However, other devices might only know their position with some error

Semantic Support for Automated Negotiation with Alliances

Companies can form alliances on the Internet to aggregate buying or selling power and create value. More concretely, together resources are shared or new possibilities are exploited that cannot be exploited individually. Most alliances are formed as a result of a negotiation process between the companies that form an alliance. This paper proposes a software framework that enables automated negotiation between alliances. Our framework allows for the semantic description of negotiation objects and their attributes, and provides a mean for the exchange of negotiation messages unambiguously interpretable by all parties involved. The proposed framework supports ad-hoc alliances by allowing parties with a common interest to negotiate on the proposal they want to make to other market participants first

On complex surfaces diffeomorphic to rational surfaces

In this paper we prove that no complex surface of general type is diffeomorphic to a rational surface, thereby completing the smooth classification of rational surfaces and the proof of the Van de Ven conjecture on the smooth invariance of Kodaira dimension.Comment: 34 pages, AMS-Te

Position estimating in peer-to-peer networks

We present two algorithms for indoor positioning estimation in peer-to-peer networks. The setup is a network of two types of devices: reference devices with a known location and blindfolded devices that can determine distances to reference devices and each other. From this information the blindfolded devices try to estimate their positions. A typical scenario is navigation inside a shopping mall where devices in the parking lot can make contact with GPS satellites, whereas devices inside the building make contact with each other, devices on the parking lot, and devices fixed to the building. The devices can measure their in-between distances, with some measurement error, and exchange positioning information. However, other devices might only know their position with some error. We present two algorithms for positioning estimation in such a peer-to-peer network. The first one is purely geometric and is based on Euclidean geometry and intersecting spheres. We rewrite the information to a linear system, which is typically overdetermined. We use least squares to ??nd the best estimate for a device its position. The second approach can be considered as a probabilistic version of the geometric approach. We estimate the probability density function that a device is located at a position given a probability density function for the positions of the other devices in the network, and a probability density function of the measured distances. First we study the case with a distance measurement to a single other user, then we focus on multiple other users. We give an approximation algorithm that is the probabilistic analogue of the intersecting spheres method. We show some simulated results where ambiguous data lead to well defined probability distributions for the position of a device. We conclude with some open questions

Synthesis and reactivity of bis(alkoxysilylamido)yttrium eta(2)-pyridyl and eta(2)-alpha-picolyl compounds

The synthesis and reactivity of bis(alkoxysilylamido)yttrium pyridyl and alpha-picolyl complexes [Me2Si(NCMe3)(OCMe3)](2) YR (R=eta(2)-(C,N)-2-NC5H4(1); R=eta(2)(C,N)-CH2-2-NC5H4 (2); R=eta(2)-(C,N)-C(H)Me-2-NC5H4 (3); R=eta(2)-(C,N)-C(H)Me-2-NC5H3-6-Me (4)) is reported 1-4 have been prepared by C-H activation of pyridine and the corresponding methyl (ethyl) and dimethyl-substituted pyridines from [Me2Si(NCMe3)(OCMe3)](2)YCH(SiMe3)(2) and by salt metathesis with the appropriate lithium salts from [Me2Si(NCMe3)(OCMe3)](2) YCl . THF. The molecular structure of 2 shows that the picolyl group is bonded to yttrium in an eta(3)-aza-allylic fashion. With dihydrogen, stepwise hydrogenation of the pyridyl fragment of 1 has been observed, finally yielding the 2,3-dihydropyridyl complex [Me2Si(NCMe3)(OCMe3)](2)YNC5H8(7). Compound 1 inserts ethene to form the alpha-methylpicolyl derivative 4. Polymerization of ethene was not observed. The pyridyl compound 1 reacts with PhC drop CH to yield the corresponding acetylide pyridine complex [Me2Si(NCMe3)(OCMe3)](2) YC drop CPh . Py (8). The complexed pyridine can be substituted by THF to give [Me2Si(NCMe3)(OCMe3)](2) YC drop CPh . THF (9), which easily loses THF and forms the base-free acetylide [Me2Si(NCMe3)(OCMe3)](2) YC drop CPh (10). Compounds 1 and 2 readily insert nitriles yielding imido-pyridine complexes. The imido-pyridine complexes that contain alpha-hydrogen readily undergo a 1,3-H shift affording the corresponding enamido-pyridine compounds. With CO, the pyridyl compound 1 gives a dipyridylketone complex {[Me2Si(NCMe3)(OCMe3)](2) Y}{mu,eta(2),eta(2)-(N,N',O)-OC(2-NC5H4)(2)} (15)

Efficacy of Manipulating Reproduction of Common Ravens to Conserve Sensitive Prey Species: Three Case Studies

Expansion of human enterprise across western North America has resulted in an increase in availability of anthropogenic resource subsidies for generalist species. This has led to increases in generalists’ population numbers across landscapes that were previously less suitable for their current demographic rates. Of particular concern are growing populations of common ravens (Corvus corax; ravens), because predation by ravens is linked to population declines of sensitive species. Ecosystem managers seek management options for mitigating the adverse effects of raven predation where unsustainable predator–prey conflicts exist. We present 3 case studies examining how manipulating reproductive success of ravens influences demographic rates of 2 sensitive prey species. Two case studies examine impacts of removing raven nests or oiling raven eggs on nest survival of greater sage-grouse (Centrocercus urophasianus; sage-grouse) within Wyoming and the Great Basin of California and Nevada, USA, respectively. The third case study uses Mojave desert tortoise (Gopherus agassizii; tortoise) decoys to examine effects of oiling raven eggs on depredation rates of juvenile tortoises in the Mojave Desert in California. Initial trial years from all 3 case studies were consistent in finding improved vital rates associated with the application of strategies for reducing reproductive success of ravens. Specifically, removal of raven nests resulted in increased nest survival of sage-grouse within treatment areas where predation by ravens was the primary cause of nest failure. In addition, nest survival of sage-grouse and survival of juvenile tortoise decoys was higher following a treatment of oiling the eggs of ravens in their nests at 2 sites within the Great Basin and 4 tortoise conservation areas in the Mojave Desert in California. Along with specialized technologies that can make techniques such as egg-oiling more feasible, these findings support these management practices as important tools for managing ravens, especially in areas where breeding ravens have negative impacts on sensitive prey species

Agonists for the adenosine A(1) receptor with tunable residence time: a case for nonribose 4-Amino-6-aryl-5-cyano-2-thiopyrimidines

Medicinal Chemistr