53,042 research outputs found

    BG Group and “Conditions” to Arbitral Jurisdiction

    Get PDF
    Although the Supreme Court has over the last decade generated a robust body of arbitration caselaw, its first decision in the area of investment arbitration under a Bilateral Investment Treaty was only handed down in 2014. BG Group v. Argentina was widely anticipated and has attracted much notice, and general approval, on the part of the arbitration community. In this paper we assess the Court’s decision from two different perspectives—the first attempts to situate it in the discourse of the American law of commercial arbitration; the second considers it in light of the expectations of the international community surrounding the proper construction of Conventions between states. Our initial goal had been to write jointly, with the hope that we could bridge our differences to find, if not common, at least neighboring, ground. On some points we did so, but ultimately our divergent appreciations of the proper way to interpret the condition precedent in the investment treaty in BG Group overcame the idealism with which we commenced the project. Nonetheless we have decided to present the two papers together to emphasize the dichotomous approaches to treaty interpretation that two moderately sensible people, who inhabit overlapping but non-congruent interpretive communities, can have.The Kay Bailey Hutchison Center for Energy, Law, and Busines

    On the Evaluation of Compton Scattering Amplitudes in String Theory

    Full text link
    We consider the Compton amplitude for the scattering of a photon and a (massless) ``electron/positron'' at one loop (i.e. genus one) in a four-dimensional fermionic heterotic string model. Starting from the bosonization of the world-sheet fermions needed to explicitly construct the spin-fields representing the space-time fermions, we present all the steps of the computation which leads to the explicit form of the amplitude as an integral of modular forms over the moduli space.Comment: 41 pages, Late

    Route Swarm: Wireless Network Optimization through Mobility

    Full text link
    In this paper, we demonstrate a novel hybrid architecture for coordinating networked robots in sensing and information routing applications. The proposed INformation and Sensing driven PhysIcally REconfigurable robotic network (INSPIRE), consists of a Physical Control Plane (PCP) which commands agent position, and an Information Control Plane (ICP) which regulates information flow towards communication/sensing objectives. We describe an instantiation where a mobile robotic network is dynamically reconfigured to ensure high quality routes between static wireless nodes, which act as source/destination pairs for information flow. The ICP commands the robots towards evenly distributed inter-flow allocations, with intra-flow configurations that maximize route quality. The PCP then guides the robots via potential-based control to reconfigure according to ICP commands. This formulation, deemed Route Swarm, decouples information flow and physical control, generating a feedback between routing and sensing needs and robotic configuration. We demonstrate our propositions through simulation under a realistic wireless network regime.Comment: 9 pages, 4 figures, submitted to the IEEE International Conference on Intelligent Robots and Systems (IROS) 201

    Comment on ``Dynamic behavior of anisotropic non-equilibrium driving lattice gases''

    Full text link
    In a recent Letter Albano and Saracco study the dynamic critical behavior of some anisotropic driven lattice gases by Monte Carlo (MC) simulations. In this Comment we point out that the Ans\"atze they use to relate the measured scaling exponents with the critical exponents analytically computed within different field-theoretical approaches do not take properly into account the strongly anisotropic nature of the phase transition, by implicitly assuming z=z=zz = z_{\bot} = z_{\parallel}. As a consequence, at variance with the claims by the authors, their MC data are not conclusive to determine which one of the field theories proposed in the literature correctly describes the universal properties of the phase transition in these lattice gases.Comment: 1 pag

    The Impact of CSI and Power Allocation on Relay Channel Capacity and Cooperation Strategies

    Full text link
    Capacity gains from transmitter and receiver cooperation are compared in a relay network where the cooperating nodes are close together. Under quasi-static phase fading, when all nodes have equal average transmit power along with full channel state information (CSI), it is shown that transmitter cooperation outperforms receiver cooperation, whereas the opposite is true when power is optimally allocated among the cooperating nodes but only CSI at the receiver (CSIR) is available. When the nodes have equal power with CSIR only, cooperative schemes are shown to offer no capacity improvement over non-cooperation under the same network power constraint. When the system is under optimal power allocation with full CSI, the decode-and-forward transmitter cooperation rate is close to its cut-set capacity upper bound, and outperforms compress-and-forward receiver cooperation. Under fast Rayleigh fading in the high SNR regime, similar conclusions follow. Cooperative systems provide resilience to fading in channel magnitudes; however, capacity becomes more sensitive to power allocation, and the cooperating nodes need to be closer together for the decode-and-forward scheme to be capacity-achieving. Moreover, to realize capacity improvement, full CSI is necessary in transmitter cooperation, while in receiver cooperation optimal power allocation is essential.Comment: Accepted for publication in IEEE Transactions on Wireless Communication

    Internames: a name-to-name principle for the future Internet

    Full text link
    We propose Internames, an architectural framework in which names are used to identify all entities involved in communication: contents, users, devices, logical as well as physical points involved in the communication, and services. By not having a static binding between the name of a communication entity and its current location, we allow entities to be mobile, enable them to be reached by any of a number of basic communication primitives, enable communication to span networks with different technologies and allow for disconnected operation. Furthermore, with the ability to communicate between names, the communication path can be dynamically bound to any of a number of end-points, and the end-points themselves could change as needed. A key benefit of our architecture is its ability to accommodate gradual migration from the current IP infrastructure to a future that may be a ubiquitous Information Centric Network. Basic building blocks of Internames are: i) a name-based Application Programming Interface; ii) a separation of identifiers (names) and locators; iii) a powerful Name Resolution Service (NRS) that dynamically maps names to locators, as a function of time/location/context/service; iv) a built-in capacity of evolution, allowing a transparent migration from current networks and the ability to include as particular cases current specific architectures. To achieve this vision, shared by many other researchers, we exploit and expand on Information Centric Networking principles, extending ICN functionality beyond content retrieval, easing send-to-name and push services, and allowing to use names also to route data in the return path. A key role in this architecture is played by the NRS, which allows for the co-existence of multiple network "realms", including current IP and non-IP networks, glued together by a name-to-name overarching communication primitive.Comment: 6 page

    Changes in the algal composition, bacterial metabolic activity and element content of biofilms developed on artificial substrata in the early phase of colonization

    Get PDF
    Changes in the algal composition and metabolic profiles of bacterial communities as well as the inorganic components were studied on artificial substrata during the early phase of biofilm formation under laboratory conditions in September 2002 and 2003. Sterile Perspex and polished quartz glass discs with a diameter of 3 cm were placed into a Perspex rack, which was immersed vertically in an aquarium containing water from a shallow soda lake. The temperature was kept constant and sufficient oxygen supply was provided. The samples were illuminated for 12 hours a day. Periphyton communities were sampled from 2 to 126 hours of exposure. In both experiments, the alteration of the number of algal species and cells as well as the carbon source utilization of microbial communities was logarithmic. In the two years, considerable differences were revealed in the magnitude of algal cell numbers. The proportion of benthic and planktonic algae showed an undulating pattern in the second experiment. One of the dominant benthic species was the diatom Achnanthidium minutissimum Kütz., while that of the planktonic, the cyanobacterium Microcystis aeruginosa Kütz. During the experiments an increase in the bacterial activities could be observed; the higher the microbial diversity and abundance that was detected, the more BIOLOG carbon sources were utilized. The examined element contents indicated interactions among algae and bacteria in the biofilms from the beginning of the colonization processes

    Universal Jamming Phase Diagram in the Hard-Sphere Limit

    Get PDF
    We present a new formulation of the jamming phase diagram for a class of glass-forming fluids consisting of spheres interacting via finite-ranged repulsions at temperature TT, packing fraction ϕ\phi or pressure pp, and applied shear stress Σ\Sigma. We argue that the natural choice of axes for the phase diagram are the dimensionless quantities T/pσ3T/p\sigma^3, pσ3/ϵp\sigma^3/\epsilon, and Σ/p\Sigma/p, where TT is the temperature, pp is the pressure, Σ\Sigma is the stress, σ\sigma is the sphere diameter, ϵ\epsilon is the interaction energy scale, and mm is the sphere mass. We demonstrate that the phase diagram is universal at low pσ3/ϵp\sigma^3/\epsilon; at low pressure, observables such as the relaxation time are insensitive to details of the interaction potential and collapse onto the values for hard spheres, provided the observables are non-dimensionalized by the pressure. We determine the shape of the jamming surface in the jamming phase diagram, organize previous results in relation to the jamming phase diagram, and discuss the significance of various limits.Comment: 8 pages, 5 figure
    corecore