11,302 research outputs found

    Performance Regulation and Tracking via Lookahead Simulation: Preliminary Results and Validation

    Full text link
    This paper presents an approach to target tracking that is based on a variable-gain integrator and the Newton-Raphson method for finding zeros of a function. Its underscoring idea is the determination of the feedback law by measurements of the system's output and estimation of its future state via lookahead simulation. The resulting feedback law is generally nonlinear. We first apply the proposed approach to tracking a constant reference by the output of nonlinear memoryless plants. Then we extend it in a number of directions, including the tracking of time-varying reference signals by dynamic, possibly unstable systems. The approach is new hence its analysis is preliminary, and theoretical results are derived for nonlinear memoryless plants and linear dynamic plants. However, the setting for the controller does not require the plant-system to be either linear or stable, and this is verified by simulation of an inverted pendulum tracking a time-varying signal. We also demonstrate results of laboratory experiments of controlling a platoon of mobile robots.Comment: A modified version will appear in Proc. 56th IEEE Conf. on Decision and Control, 201

    Optical studies of two LMC X-ray transients : RX J0544.1-7100 and RX J0520.5-6932

    Full text link
    We report observations which confirm the identities of the optical counterpart to the transient sources RX J0544.1-7100 and RX J0520.5-6932. The counterparts are suggested to be a B-type stars. Optical data from the observations carried out at ESO and SAAO, together with results from the OGLE data base, are presented. In addition, X-ray data from the RXTE all-sky monitor are investigated for long term periodicities. A strong suggestion for a binary period of 24.4d is seen in RX J0520.5-6932 from the OGLE data.Comment: 6 pages, 7 figure

    The Scientific Paradigm of Islamic Education Management: Phenomenology Perspective

    Full text link
    This paper intends to explore the possibility that phenomenology can be used as one of the foundations of scientific epistemology of Islamic education management. Scientific management of Islamic education would not be sufficient if only positivistic approached scientifically. Behaviors that contain messages of moral, theological and ideological embraced by managers, implementers and users of Islamic educational institutions are very complicated. To be able to describe these phenomena with a reasonable and until the deeply meaning (eidos), so phenomenological approach is needed. This approach can be used as a basis in developing others the science of Islamic education management. The science of Islamic education management can have a number of scientific fields (The science of diniyyah, madrassas, Islamic schools, and Islamic higher education management) and gave birth to a number of expertise (administrative staff, headmaster and superintendent at the madrasah level)

    Domain Wall Bubbles in High Energy Heavy Ion Collisions

    Get PDF
    It has been recently shown that meta-stable domain walls exist in high-density QCD (μ0\mu\neq 0) as well as in QCD with large number of colors (NcN_c\to\infty), with the lifetime being exponentially long in both cases. Such metastable domain walls may exist in our world as well, especially in hot hadronic matter with temperature close to critical. In this paper we discuss what happens if a bubble made of such wall is created in heavy ion collisions, in the mixed phase between QGP and hadronic matter. We show it will further be expanded to larger volume 20fm3\sim 20 fm^3 by the pion pressure, before it disappears, either by puncture or contraction. Both scenarios leave distinctive experimental signatures of such events, negatively affecting the interference correlations between the outgoing pions.Comment: 6 pages, 1 fi

    An assessment of pile driveability analyses for monopile foundations

    Get PDF
    Several methodologies to predict the static soil resistance to driving (SRD) available in the literature have found wide use in the offshore industry over the last decades. These range from simple methods that require few soil strength parameters to more advanced semi-empirical methods that correlate the driving resistance to cone penetration test measurements. These methods were primarily developed based on driving records for piles less than 2.5m in diameter i.e. much smaller than the monopiles currently used in the offshore wind industry today. The aim of this study is to evaluate the accuracy of some of the most widely used SRD prediction methods when employed for driveability analysis of large diameter monopile foundations, by comparing the predicted SRD profiles with the driving records of 6.5m diameter monopiles installed in the Danish region of the North Sea

    Heavy metals contaminating the environment of a progressive supranuclear palsy cluster induce tau accumulation and cell death in cultured neurons

    Get PDF
    Progressive supranuclear palsy (PSP) is a neurodegenerative disorder characterized by the presence of intracellular aggregates of tau protein and neuronal loss leading to cognitive and motor impairment. Occurrence is mostly sporadic, but rare family clusters have been described. Although the etiopathology of PSP is unknown, mutations in the MAPT/tau gene and exposure to environmental toxins can increase the risk of PSP. Here, we used cell models to investigate the potential neurotoxic effects of heavy metals enriched in a highly industrialized region in France with a cluster of sporadic PSP cases. We found that iPSC-derived iNeurons from a MAPT mutation carrier tend to be more sensitive to cell death induced by chromium (Cr) and nickel (Ni) exposure than an isogenic control line. We hypothesize that genetic variations may predispose to neurodegeneration induced by those heavy metals. Furthermore, using an SH-SY5Y neuroblastoma cell line, we showed that both heavy metals induce cell death by an apoptotic mechanism. Interestingly, Cr and Ni treatments increased total and phosphorylated tau levels in both cell types, implicating Cr and Ni exposure in tau pathology. Overall, this study suggests that chromium and nickel could contribute to the pathophysiology of tauopathies such as PSP by promoting tau accumulation and neuronal cell death

    2-methyl-4-chlorophenoxyacetic acid and bromoxynil herbicide death.

    Get PDF
    CASE REPORT: We report a fatal case of a 37 year old gentleman who ingested a MCPA/bromoxynil co-formulation herbicide. Although clinically well on initial examination, our patient declined dramatically over his 18 h admission with increasing CO2 production, hyperthermia and metabolic derangement to eventually die from cardiac asystole 20 h post ingestion. Two hours after ingestion the MCPA concentration was 83.9 μg/mL and bromoxynil concentration was 137 μg/mL. DISCUSSION: The patients' mechanism of death appeared to be uncoupling of oxidative phosphorylation, excess CO2 production and hyperthermia. There is limited knowledge on the acute toxicity of these herbicides, in particular bromoxynil, and this case highlights the relentless progression of severe toxicity in humans.The collaboration was supported by an NHMRC Program Grant (1055176). Geoff Isbister is supported by an NHMRC Senior Research Fellowship ID 1061041 and Mike Roberts is supported by an NHMRC Senior Principal Research Fellowship ID 1002611
    corecore