5,460 research outputs found

    Organisational Responses to Discontinuous Innovation: A Case Study Approach

    Get PDF
    Research that examines entrant-incumbent dynamics often points to the organisational limitations that constrain incumbents from successfully pursuing new technologies or fending off new entrants. Some incumbents are nevertheless able to successfully implement organisational structures and develop routines that overcome these institutional constraints. We provide a case-study analysis of how three firms - Motorola, IBM and Kodak - responded to discontinuous innovations and the associated structural and organisational limitations that are typical to incumbent organisations. Each firm was able to capture gains from new technologies and develop profitable products in emerging markets, although their abilities to sustain these gains varied due to subsequent organisational changes. Drawing from these case studies, we synthesise how firms can institute organisational strategies to continue to capture gains from disruptive innovations. A schema suggests that particular organisational strategies are comparatively optimal for corresponding points along an innovation lifecycle

    Modeling Supreme Court Strategic Decision Making: Congressional Constraint

    Get PDF
    This paper addresses the contradictory results obtained in Segal (1997) and Spiller and Gely (1992) concerning the impact of institutional constraints on the US Supreme Court decisionmaking. by adapting the Spiller and Gely model to the data set utilized by Segal. The major findings are as follows: first, by adapting the Spiller and Gely (1992) maximum likelihood model to the Segal (1997) dataset, we find support for the hypothesis that the Court adjusts its decisions to Presidential and congressional preferences. Second, data from 1947-92 indicate that the average probability of the Court being constrained has been approximately one third. Third, we show that the results obtained in Segal (1997) are the product of biases introduced by a misspecified econometric model. Finally, the estimation highlights the usefulness of Krehbiel’s model of legislative decision-making.

    The Shadows of Life: Medicaid\u27s Failure of Health Care\u27s Moral Test

    Get PDF
    North Carolina Medicaid covers one-fifth of the state’s population and makes up approximately one-third of the budget. Yet the state has experienced increasing costs and worsening health outcomes over the past decade, while socioeconomic disparities persist among communities. In this article, the authors explore the factors that influence these trends and provide a series of policy lessons to inform the state’s current reform efforts following the recent approval of North Carolina’s Section 1115 waiver by the Centers for Medicare and Medicaid Services. The authors used health, social, and financial data from the state Department of Health and Human Services, the Robert Wood Johnson Foundation, and the University of North Carolina to identify the highest cost counties in North Carolina. They found higher per beneficiary spending to be inversely related to population health, with many counties with the most expensive beneficiaries also reporting poor health outcomes. These trends appear to be attributed to a breakdown in access to basic health services, with high cost counties often lacking adequate numbers of health care providers and possessing limited health care services, leading patients to primarily engage the health care system in a reactive manner and predominantly in institutional care settings. To illustrate this pattern, the authors developed case studies of Tyrrell County and Graham County, which respectively are home to the state’s worst health outcomes and most expensive Medicaid beneficiaries. The authors combined stories of these counties with the larger historical trends to offer policy recommendations to help reorient North Carolina Medicaid around patient needs. The results shed light on traditionally understudied hotspots of cost and poor outcomes in North Carolina, while proposing tangible steps to support reform

    Tunneling Spectroscopy of Disordered Two-Dimensional Electron Gas in the Quantum Hall Regime

    Full text link
    Recently, Dial et al. presented measurements of the tunneling density of states into the bulk of a two dimensional electron gas under strong magnetic fields. Several high energy features appear in the measured spectrum showing a distinct dependence on filling factor and a unique response to temperature. We present a quantitative account of the observed structure, and argue it results from the repulsive Coulomb interactions between the tunneling electron and states localized at disorder potential wells. The quenching of the kinetic energy by the applied magnetic field leads to an electron addition spectrum that is primarily determined by the external magnetic field and is nearly independent of the disorder potential. Using a Hartree-Fock model we reproduce the salient features of the observed structure

    New Dependencies of Hierarchies in Polynomial Optimization

    Full text link
    We compare four key hierarchies for solving Constrained Polynomial Optimization Problems (CPOP): Sum of Squares (SOS), Sum of Diagonally Dominant Polynomials (SDSOS), Sum of Nonnegative Circuits (SONC), and the Sherali Adams (SA) hierarchies. We prove a collection of dependencies among these hierarchies both for general CPOPs and for optimization problems on the Boolean hypercube. Key results include for the general case that the SONC and SOS hierarchy are polynomially incomparable, while SDSOS is contained in SONC. A direct consequence is the non-existence of a Putinar-like Positivstellensatz for SDSOS. On the Boolean hypercube, we show as a main result that Schm\"udgen-like versions of the hierarchies SDSOS*, SONC*, and SA* are polynomially equivalent. Moreover, we show that SA* is contained in any Schm\"udgen-like hierarchy that provides a O(n) degree bound.Comment: 26 pages, 4 figure

    Analytic Evidence for Continuous Self Similarity of the Critical Merger Solution

    Full text link
    The double cone, a cone over a product of a pair of spheres, is known to play a role in the black-hole black-string phase diagram, and like all cones it is continuously self similar (CSS). Its zero modes spectrum (in a certain sector) is determined in detail, and it implies that the double cone is a co-dimension 1 attractor in the space of those perturbations which are smooth at the tip. This is interpreted as strong evidence for the double cone being the critical merger solution. For the non-symmetry-breaking perturbations we proceed to perform a fully non-linear analysis of the dynamical system. The scaling symmetry is used to reduce the dynamical system from a 3d phase space to 2d, and obtain the qualitative form of the phase space, including a non-perturbative confirmation of the existence of the "smoothed cone".Comment: 25 pages, 4 figure

    Templates for stellar mass black holes falling into supermassive black holes

    Get PDF
    The spin modulated gravitational wave signals, which we shall call smirches, emitted by stellar mass black holes tumbling and inspiralling into massive black holes have extremely complicated shapes. Tracking these signals with the aid of pattern matching techniques, such as Wiener filtering, is likely to be computationally an impossible exercise. In this article we propose using a mixture of optimal and non-optimal methods to create a search hierarchy to ease the computational burden. Furthermore, by employing the method of principal components (also known as singular value decomposition) we explicitly demonstrate that the effective dimensionality of the search parameter space of smirches is likely to be just three or four, much smaller than what has hitherto been thought to be about nine or ten. This result, based on a limited study of the parameter space, should be confirmed by a more exhaustive study over the parameter space as well as Monte-Carlo simulations to test the predictions made in this paper.Comment: 12 pages, 4 Tables, 4th LISA symposium, submitted to CQ

    Classical Effective Field Theory and Caged Black Holes

    Full text link
    Matched asymptotic expansion is a useful technique in General Relativity and other fields whenever interaction takes place between physics at two different length scales. Here matched asymptotic expansion is argued to be equivalent quite generally to Classical Effective Field Theory (CLEFT) where one (or more) of the zones is replaced by an effective theory whose terms are organized in order of increasing irrelevancy, as demonstrated by Goldberger and Rothstein in a certain gravitational context. The CLEFT perspective has advantages as the procedure is clearer, it allows a representation via Feynman diagrams, and divergences can be regularized and renormalized in standard field theoretic methods. As a side product we obtain a wide class of classical examples of regularization and renormalization, concepts which are usually associated with Quantum Field Theories. We demonstrate these ideas through the thermodynamics of caged black holes, both simplifying the non-rotating case, and computing the rotating case. In particular we are able to replace the computation of six two-loop diagrams by a single factorizable two-loop diagram, as well as compute certain new three-loop diagrams. The results generalize to arbitrary compactification manifolds. For caged rotating black holes we obtain the leading correction for all thermodynamic quantities. The angular momentum is found to non-renormalize at leading order.Comment: 33 pages 11 figures. v2: Relatively minor changes, detailed at end of introductio

    The effect of ligands on the size distribution of copper nanoclusters: insights from molecular dynamics simulations

    Full text link
    Controlling the size distribution in the nucleation of copper particles is crucial for achieving nanocrystals with desired physical and chemical properties. However, their synthesis involves a complex system of solvents, ligands, and copper precursors with intertwining effects on the size of the nanoclusters. We combine molecular dynamics simulations and DFT calculations to provide insight into the nucleation mechanism in the presence of a triphenylphosphite ligand. We identify the crucial role of the strength of the metal-phosphine bond in inhibiting the cluster's growth. We demonstrate computationally several practical routes to fine-tune the bond strength by modifying the side groups of the additive. Our work provides molecular insight into the complex nucleation process of protected copper nanocrystals, which can assist in controlling their size distribution and, eventually, their morphology

    Matched Asymptotic Expansion for Caged Black Holes - Regularization of the Post-Newtonian Order

    Full text link
    The "dialogue of multipoles" matched asymptotic expansion for small black holes in the presence of compact dimensions is extended to the Post-Newtonian order for arbitrary dimensions. Divergences are identified and are regularized through the matching constants, a method valid to all orders and known as Hadamard's partie finie. It is closely related to "subtraction of self-interaction" and shows similarities with the regularization of quantum field theories. The black hole's mass and tension (and the "black hole Archimedes effect") are obtained explicitly at this order, and a Newtonian derivation for the leading term in the tension is demonstrated. Implications for the phase diagram are analyzed, finding agreement with numerical results and extrapolation shows hints for Sorkin's critical dimension - a dimension where the transition turns second order.Comment: 28 pages, 5 figures. v2:published versio
    • …
    corecore