6,399 research outputs found

    Analysis of Competition in the Defense Industrial Base: An F/A-22 Case Study

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    Consolidation of the defense industrial base has led to concerns about whether enough competition exists between remaining firms to maintain needed cost reduction and innovation. We examine competition in the U.S. defense industrial base by performing an in-depth case study of Lockheed Martin and the F-22 program that considers multiple tiers of the industrial base. We find that defense firm specialization has led to outsourcing practices and arguably a more robust U.S. defense industrial base. Implications for government policy are identified

    Lie and conditional symmetries of a class of nonlinear (1+2)-dimensional boundary value problems

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    A new definition of conditional invariance for boundary value problems involving a wide range of boundary conditions (including initial value problems as a special case) is proposed. It is shown that other definitions worked out in order to find Lie symmetries of boundary value problems with standard boundary conditions, follow as particular cases from our definition. Simple examples of direct applicability to the nonlinear problems arising in applications are demonstrated. Moreover, the successful application of the definition for the Lie and conditional symmetry classification of a class of (1+2)-dimensional nonlinear boundary value problems governed by the nonlinear diffusion equation in a semi-infinite domain is realised. In particular, it is proved that there is a special exponent, k=2k=-2, for the power diffusivity uku^k when the problem in question with non-vanishing flux on the boundary admits additional Lie symmetry operators compared to the case k2k\not=-2. In order to demonstrate the applicability of the symmetries derived, they are used for reducing the nonlinear problems with power diffusivity uku^k and a constant non-zero flux on the boundary (such problems are common in applications and describing a wide range of phenomena) to (1+1)-dimensional problems. The structure and properties of the problems obtained are briefly analysed. Finally, some results demonstrating how Lie invariance of the boundary value problem in question depends on geometry of the domain are presented.Comment: 25 pages; the main results were presented at the Conference Symmetry, Methods, Applications and Related Fields, Vancouver, Canada, May 13-16, 201

    Investigating the Integration of Acquired Firms in High-technology Industries: Implications for Industrial Policy

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    Acquisition activity persists despite evidence that acquisitions do not improve firm performance. Further, government policy toward the defense industry has advocated consolidation in the name of nominal cost savings. We explore the role acquisitions play toward technology transfer and begin to identify factors associated with acquisition success through a review of existing research on post-acquisition performance that primarily considers acquiring firm stock performance. Using this research as a foundation, we build a model to analyze post-acquisition performance using a sample of high-technology firms. Results suggest critical success factors associated with post-acquistion stock performance are poorly understood. We conclude that proactive government policy toward high-technology industry mergers and acquisitions may be misguided due to difficulty in predicting acquisition outcome

    An Initial Look at Technology and Institutions on Defense Industry Consolidation

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    Conventional wisdom holds that defense industry consolidation resulted from decreased defense spending. However, we maintain that understanding dynamic changes in key defense institutions helps provide a more complete explanation for observed consolidation. Specifically, we examine the interaction of evolving technology and changing institutions. Institutions reviewed include procurement policies, weapons requirements process and the procurement organizations. We take an initial look at the industry and highlight how these changes influenced transaction costs in the defense industry more fully explain the forces driving consolidation and provide greater insight to policy makers seeking to improve the performance of the defense industry. Further research is needed to build a robust institutional framework of the defense industry and the related government agencies to allow better policy prescriptions

    Is Counseling Integral to Buprenorphine-Assisted Opioid Addiction Treatment? Examining Counseling Participation and Treatment Retention at a Richmond, Virginia Clinic

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    Treatment providers in Virginia are required by law to offer counseling or referrals to all clients receiving medication-assisted opioid use disorder (OUD) treatment (American Society of Addiction Medicine, 2016; Medical Society of Virginia, 2018). Prescribing physicians widely regard counseling as a critical component of medication-assisted OUD treatment (Lin, Lofwall, Walsh, & Knudsen, 2019), and clients perceive counseling to be among the most important factors promoting recovery from opioid dependence (Hay, Huhn, Tompkins, & Dunn, 2019). Research investigating the efficacy of counseling as an OUD treatment component, however, has been equivocal to date (Brown, 2018; Dugosh et al., 2016). The current study explored associations between counseling type, counseling attendance rates, and treatment duration among a convenience sample of 71 clients receiving buprenorphine-assisted OUD treatment at a Richmond, Virginia outpatient clinic. Among early phase clients (in treatment for 1 to 11 months) only, counseling type was significantly associated with treatment length (p = .019). Among all clients, counseling attendance rate was significantly associated with treatment length (p = .006). Findings suggest that treatment phase moderates the effects of counseling on retention. While this study corroborates previous research linking counseling to positive OUD treatment outcomes for some clients (Dugosh et al., 2016), results emphasize the need for individualized, client-centered treatment planning with ongoing adjustment according to evolving client needs and treatment goals

    Rate of Convergence to Barenblatt Profiles for the Fast Diffusion Equation with a Critical Exponent

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    We study the asymptotic behaviour near extinction of positive solutions of the Cauchy problem for the fast diffusion equation with a critical exponent. After a suitable rescaling which yields a non--linear Fokker--Planck equation, we find a continuum of algebraic rates of convergence to a self--similar profile. These rates depend explicitly on the spatial decay rates of initial data. This improves a previous result on slow convergence for the critical fast diffusion equation ({\sc Bonforte et al}. in Arch Rat Mech Anal 196:631--680, 2010) and provides answers to some open problems

    Local Climatological Data : Urbana, 1889-1970

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    Urbana has a temperate continental climate with characteristics reflecting its geographical position in Illinois. Urbana's climate is representative of the conditions found in East Central Illinois, which is primarily an area of climatic transition between the northern and southern sectors of the state.published or submitted for publicationis peer reviewedOpenOpe

    Travelling-wave analysis of a model describing tissue degradation by bacteria

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    We study travelling-wave solutions for a reaction-diffusion system arising as a model for host-tissue degradation by bacteria. This system consists of a parabolic equation coupled with an ordinary differential equation. For large values of the `degradation-rate parameter' solutions are well approximated by solutions of a Stefan-like free boundary problem, for which travelling-wave solutions can be found explicitly. Our aim is to prove the existence of travelling waves for all sufficiently large wave-speeds for the original reaction-diffusion system and to determine the minimal speed. We prove that for all sufficiently large degradation rates the minimal speed is identical to the minimal speed of the limit problem. In particular, in this parameter range, nonlinear selection of the minimal speed occurs.Comment: 15 pages, 3 figure

    Asymptotic analysis of a doubly nonlinear diffusion equation

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    We investigate the doubly nonlinear diffusion equation ∂u/∂t=1/n ∇.(u^m│∇u│^n-1) ∇u) and the same equation expressed in terms of a `pressure' variable. We classify various classes of compacted supported solutions, as well as finite-mass solutions that decay algebraically at infinity. A number of novel phenomena are identified, particularly for n<0, that seem to us worthy of further mathematical investigation

    Wastewater Management Alternatives for the Salt Pond Region of Westerly, Rhode Island (With Special Emphasis on the Winnapaug Pond Watershed)

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    As people move toward the coasts in growing numbers, the coastal zone is faced with ever increasing development pressures. The Town of Westerly, Rhode Island is experiencing many of the problems associated with these pressures. In order to expand a motel in the Misquamicut section of Westerly, the current owner of the property has proposed to extend city sewer lines to this area at his own cost. Afterward the line would be turned over to the town. While extension of sewer lines may relieve some local septic system failure problems, it could also spur more rapid and extensive growth. Over-development may lead to irreparable damage to the sensitive barrier beach - salt pond environment. Furthermore, this area is susceptible to extensive storm damage, flooding, and high rates of erosion, which make it unsafe for development. Thus, sewer lines may not be the best wastewater management alternative. Rhode Island is currently considering legislation that would enable local communities to develop Wast Water Management districts. This alternative has been proven to be an effective method of managing septic system related pollution in other communities. In order to address septic system problems, the Town of Westerly should develop a Waste Water Management District for its salt pond watersheds. In this manner, wastewater problems could be mitigated without encouraging intensified development
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