1,267 research outputs found

    Packetized Predictive Control for Rate-Limited Networks via Sparse Representation

    Get PDF
    We study a networked control architecture for linear time-invariant plants in which an unreliable data-rate limited network is placed between the controller and the plant input. The distinguishing aspect of the situation at hand is that an unreliable data-rate limited network is placed between controller and the plant input. To achieve robustness with respect to dropouts, the controller transmits data packets containing plant input predictions, which minimize a finite horizon cost function. In our formulation, we design sparse packets for rate-limited networks, by adopting an an ell-0 optimization, which can be effectively solved by an orthogonal matching pursuit method. Our formulation ensures asymptotic stability of the control loop in the presence of bounded packet dropouts. Simulation results indicate that the proposed controller provides sparse control packets, thereby giving bit-rate reductions for the case of memoryless scalar coding schemes when compared to the use of, more common, quadratic cost functions, as in linear quadratic (LQ) control.Comment: 9 pages, 7 figures. arXiv admin note: text overlap with arXiv:1307.824

    Sparsely-Packetized Predictive Control by Orthogonal Matching Pursuit

    Get PDF
    We study packetized predictive control, known to be robust against packet dropouts in networked systems. To obtain sparse packets for rate-limited networks, we design control packets via an L0 optimization, which can be effectively solved by orthogonal matching pursuit. Our formulation ensures asymptotic stability of the control loop in the presence of bounded packet dropouts.Comment: 3-page extended abstract for MTNS 2012 with 3 figure

    Sparse Packetized Predictive Control for Networked Control over Erasure Channels

    Get PDF
    We study feedback control over erasure channels with packet-dropouts. To achieve robustness with respect to packet-dropouts, the controller transmits data packets containing plant input predictions, which minimize a finite horizon cost function. To reduce the data size of packets, we propose to adopt sparsity-promoting optimizations, namely, ell-1-ell-2 and ell-2-constrained ell-0 optimizations, for which efficient algorithms exist. We derive sufficient conditions on design parameters, which guarantee (practical) stability of the resulting feedback control systems when the number of consecutive packet-dropouts is bounded.Comment: IEEE Transactions on Automatic Control, Volume 59 (2014), Issue 7 (July) (to appear

    FU.S. banking deregulation, small businesses, and interstate insurance of personal income

    Get PDF
    We estimate the effects of deregulation of U.S. banking restrictions on the amount of interstate personal income insurance during the period 1970–2001. Interstate income insurance occurs when personal income reacts less than one-to-one to state-specific shocks to output. We find that income insurance improved after banking deregulation, and that this effect is larger in states where small businesses are more important. We further show that the impact of deregulation is stronger for proprietors’ income than other components of personal income. Our explanation of this result centers on the role of banks as a prime source of small business finance and on the close intertwining of the personal and business finances of small business owners. Our analysis casts light on the real effects of bank deregulation, on the risk sharing function of banks, and on the integration of bank markets.Financial deregulation, integration of bank markets, interstate risk sharing, small business finance.

    Risk sharing and portfolio allocation in EMU

    Get PDF
    This paper investigates whether risk sharing, measured as income and consumption smoothing, among countries in the EU and the European Economic and Monetary Union (EMU) has increased since the adoption of the euro. We ask: Have the recent increase in foreign equity and debt holdings been associated with more risk sharing? Do certain classes of assets (debt, equity, foreign direct investment) provide relatively more or less risk sharing? Do liabilities provide risk sharing differently from assets? Do investments in EMU countries provide more or less risk sharing per euro invested compared to investments in non-EMU countries? Has increased banking integration improved risk sharing? Due to the short span of years since the introduction of the euro, our results are tentative, but they indicate that the monetary union has facilitated risk sharing, although the level of risk sharing is still much below the level found among U.S. states.Financial integration, Risk sharing, EU, EMU, Portfolio diversification, Banking market integration, Panel data analysis, Demyanyk, Ostergaard, S�rensen

    U.S. Banking Deregulation, Small Businesses,and Interstate Insurance of Personal Income

    Get PDF
    We estimate the effects of deregulation of U.S. banking restrictions on the amount of interstate personal income insurance during the period 1970–2001. Interstate income insurance occurs when personal income reacts less than one-to-one to state-specific shocks to output. We find that income insurance improved after banking deregulation, and that this effect is larger in states where small businesses are more important. We further show that the impact of deregulation is stronger for proprietors’ income than other components of personal income. Our explanation of this result centers on the role of banks as a prime source of small business finance and on the close intertwining of the personal and business finances of small business owners. Our analysis casts light on the real effects of bank deregulation, on the insurance function of banks, and on the integration of bank markets.Financial deregulation, integration of bank markets, interstate risk shar-ing, small business finance.

    A novel KIF11 mutation in a Turkish patient with microcephaly, lymphedema, and chorioretinal dysplasia from a consanguineous family.

    Get PDF
    Microcephaly–lymphedema–chorioretinal dysplasia (MLCRD) syndrome is a rare syndrome that was first described in 1992. Characteristic craniofacial features include severe microcephaly, upslanting palpebral fissures, prominent ears, a broad nose, and a long philtrum with a pointed chin. Recently, mutations in KIF11 have been demonstrated to cause dominantly inherited MLCRD syndrome. Herein, we present a patient with MLCRD syndrome whose parents were first cousins. The parents are unaffected, and thus a recessive mode of inheritance for the disorder was considered likely. However, the propositus carries a novel, de novo nonsense mutationinexon2 of KIF11. The patient also had midline cleft tongue which has not previously been described in this syndrome

    Exclusive neuronal expression of SUCLA2 in the human brain

    Get PDF
    SUCLA2 encodes the ATP-forming subunit (A-SUCL-) of succinyl-CoA ligase, an enzyme of the citric acid cycle. Mutations in SUCLA2 lead to a mitochondrial disorder manifesting as encephalomyopathy with dystonia, deafness and lesions in the basal ganglia. Despite the distinct brain pathology associated with SUCLA2 mutations, the precise localization of SUCLA2 protein has never been investigated. Here we show that immunoreactivity of A-SUCL- in surgical human cortical tissue samples was present exclusively in neurons, identified by their morphology and visualized by double labeling with a fluorescent Nissl dye. A-SUCL- immunoreactivity co-localized >99% with that of the d subunit of the mitochondrial F0-F1 ATP synthase. Specificity of the anti-A-SUCL- antiserum was verified by the absence of labeling in fibroblasts from a patient with a complete deletion of SUCLA2. A-SUCL- immunoreactivity was absent in glial cells, identified by antibodies directed against the glial markers GFAP and S100. Furthermore, in situ hybridization histochemistry demonstrated that SUCLA2 mRNA was present in Nissl-labeled neurons but not glial cells labeled with S100. Immunoreactivity of the GTP-forming subunit (G-SUCL-) encoded by SUCLG2, or in situ hybridization histochemistry for SUCLG2 mRNA could not be demonstrated in either neurons or astrocytes. Western blotting of post mortem brain samples revealed minor G-SUCL- immunoreactivity that was however, not upregulated in samples obtained from diabetic versus non-diabetic patients, as has been described for murine brain. Our work establishes that SUCLA2 is expressed exclusively in neurons in the human cerebral cortex
    corecore