287 research outputs found

    Distributed negotiation in future power networks : rapid prototyping using multi-agent system

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    Technologies like multi-agent system (MAS) have the capability to deal with future power grid requirements such as frequency management and voltage control under a flexible, intelligent and active feature. Based on web of cells (WoC) architecture proposed by European Liaison on Electricity Committed Towards longer-term Research Activity Integrated Research Programme (ELECTRA IRP), a distributed MAS with distributed negotiation ability for future distributed control (including frequency management and voltage control) is proposed. Each cell is designed as an intelligent agent and is investigated in case studies with constraints, where each agent can only communicate with its neighbouring agents. The interaction logic among agents is according to the distributed negotiation algorithm under consideration by the authors. Simulation results indicate that the WoC architecture could negotiate resources in a distributed manner and achieve successful exchange of resources by coordinating distributed agents. Moreover, the prototype reported in this paper can be extended further for future grids' distributed control regimes. The option of MAS to be exploited for the support of the development and integration of novel power system concepts is explored

    Arthroscopic anterior talofibular ligament repair for lateral instability of the ankle

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    UNLABELLED: Although several arthroscopic procedures for lateral ligament instability of the ankle have been reported recently, it is difficult to augment the reconstruction by arthroscopically tightening the inferior extensor retinaculum. There is also concern that when using the inferior extensor retinaculum, this is not strictly an anatomical repair since its calcaneal attachment is different to that of the calcaneofibular ligament. If a ligament repair is completed firmly, it is unnecessary to add argumentation with inferior extensor retinaculum. The authors describe a simplified technique, repair of the lateral ligament alone using a lasso-loop stitch, which avoids additionally tighten the inferior extensor retinaculum. In this paper, it is described an arthroscopic anterior talofibular ligament repair using lasso-loop stitch alone for lateral instability of the ankle that is likely safe for patients and minimal invasive. LEVEL OF EVIDENCE: Therapeutic study, Level V

    Transitioning from centralized to distributed control : using SGAM to support a collaborative development of web of cells architecture for real time control

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    This paper shares some early experiences of developing the Web of Cells (WoC) concept for real time implementation supported by the Smart Grid Architecture Model (SGAM) reference framework. One of the use cases identified for the WoC concept is elaborated upon and is mapped to SGAM, providing one of the first examples where the SGAM reference framework has been used to develop a future distributed control architecture for real time implementation in power systems. Furthermore, this paper offers some insight into the key contributions that this approach can bring, such as a more effective interdisciplinary collaboration, better understanding of the control problem, and its implementation and validation

    A novel decentralized responsibilizing primary frequency control

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    There is an emerging need to prioritize remedial frequency control measures closer to the source of an imbalance event. This approach, referred to herein as responsibilization, is challenging to achieve within the conventional operating times of Primary Frequency Control (PFC) and therefore novel methods are sought. In this letter, a novel decentralized PFC is proposed which relies on transient phase offset to achieve fast responsibilization autonomously. The effectiveness of the proposed control is demonstrated by real-time simulations and its stability assessed by small-signal analysis. This development will lead to increased system resilience during imbalance events

    Post-paralysis tyrosine kinase inhibition with masitinib abrogates neuroinflammation and slows disease progression in inherited amyotrophic lateral sclerosis

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    Background: In the SOD1G93A mutant rat model of amyotrophic lateral sclerosis (ALS), neuronal death and rapid paralysis progression are associated with the emergence of activated aberrant glial cells that proliferate in the degenerating spinal cord. Whether pharmacological downregulation of such aberrant glial cells will decrease motor neuron death and prolong survival is unknown. We hypothesized that proliferation of aberrant glial cells is dependent on kinase receptor activation, and therefore, the tyrosine kinase inhibitor masitinib (AB1010) could potentially control neuroinflammation in the rat model of ALS. Methods: The cellular effects of pharmacological inhibition of tyrosine kinases with masitinib were analyzed in cell cultures of microglia isolated from aged symptomatic SOD1G93A rats. To determine whether masitinib prevented the appearance of aberrant glial cells or modified post-paralysis survival, the drug was orally administered at 30 mg/kg/day starting after paralysis onset. Results: We found that masitinib selectively inhibited the tyrosine kinase receptor colony-stimulating factor 1R (CSF-1R) at nanomolar concentrations. In microglia cultures from symptomatic SOD1G93A spinal cords, masitinib prevented CSF-induced proliferation, cell migration, and the expression of inflammatory mediators. Oral administration of masitinib to SOD1G93A rats starting after paralysis onset decreased the number of aberrant glial cells, microgliosis, and motor neuron pathology in the degenerating spinal cord, relative to vehicle-treated rats. Masitinib treatment initiated 7 days after paralysis onset prolonged post-paralysis survival by 40 %. Conclusions: These data show that masitinib is capable of controlling microgliosis and the emergence/expansion of aberrant glial cells, thus providing a strong biological rationale for its use to control neuroinflammation in ALS. Remarkably, masitinib significantly prolonged survival when delivered after paralysis onset, an unprecedented effect in preclinical models of ALS, and therefore appears well-suited for treating ALS.Agencia Nacional de InvestigaciĂłn e InnovaciĂł

    Laboratory coupling approach

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    This chapter deals with the coupling of smart grid laboratories for joint experiments. Therefore, various possibilities are outlined and a reference implementation is introduced. Finally, the vision of a distributed, virtual research infrastructure is presented

    Deeply virtual and exclusive electroproduction of omega mesons

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    The exclusive omega electroproduction off the proton was studied in a large kinematical domain above the nucleon resonance region and for the highest possible photon virtuality (Q2) with the 5.75 GeV beam at CEBAF and the CLAS spectrometer. Cross sections were measured up to large values of the four-momentum transfer (-t < 2.7 GeV2) to the proton. The contributions of the interference terms sigma_TT and sigma_TL to the cross sections, as well as an analysis of the omega spin density matrix, indicate that helicity is not conserved in this process. The t-channel pi0 exchange, or more generally the exchange of the associated Regge trajectory, seems to dominate the reaction gamma* p -> omega p, even for Q2 as large as 5 GeV2. Contributions of handbag diagrams, related to Generalized Parton Distributions in the nucleon, are therefore difficult to extract for this process. Remarkably, the high-t behaviour of the cross sections is nearly Q2-independent, which may be interpreted as a coupling of the photon to a point-like object in this kinematical limit.Comment: 15 pages,19 figure

    Q^2 Dependence of the S_{11}(1535) Photocoupling and Evidence for a P-wave resonance in eta electroproduction

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    New cross sections for the reaction ep→eâ€Čηpep \to e'\eta p are reported for total center of mass energy WW=1.5--2.3 GeV and invariant squared momentum transfer Q2Q^2=0.13--3.3 GeV2^2. This large kinematic range allows extraction of new information about response functions, photocouplings, and ηN\eta N coupling strengths of baryon resonances. A sharp structure is seen at W∌W\sim 1.7 GeV. The shape of the differential cross section is indicative of the presence of a PP-wave resonance that persists to high Q2Q^2. Improved values are derived for the photon coupling amplitude for the S11S_{11}(1535) resonance. The new data greatly expands the Q2Q^2 range covered and an interpretation of all data with a consistent parameterization is provided.Comment: 31 pages, 9 figure

    Q2Q^2 Dependence of Quadrupole Strength in the γ∗p→Δ+(1232)→pπ0\gamma^*p\to\Delta^+(1232)\to p \pi^0 Transition

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    Models of baryon structure predict a small quadrupole deformation of the nucleon due to residual tensor forces between quarks or distortions from the pion cloud. Sensitivity to quark versus pion degrees of freedom occurs through the Q2Q^2 dependence of the magnetic (M1+M_{1+}), electric (E1+E_{1+}), and scalar (S1+S_{1+}) multipoles in the γ∗p→Δ+→pπ0\gamma^* p \to \Delta^+ \to p \pi^0 transition. We report new experimental values for the ratios E1+/M1+E_{1+}/M_{1+} and S1+/M1+S_{1+}/M_{1+} over the range Q2Q^2= 0.4-1.8 GeV2^2, extracted from precision p(e,eâ€Čp)π∘p(e,e 'p)\pi^{\circ} data using a truncated multipole expansion. Results are best described by recent unitary models in which the pion cloud plays a dominant role.Comment: 5 pages, 5 figures, 1 table. To be published in Phys. Rev. Lett. (References, figures and table updated, minor changes.
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