23,515 research outputs found

    Leading from the classroom: the impact of the assistant headteacher in primary schools

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    Living Originalism

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    Originalists routinely argue that originalism is the only coherent and legitimate theory of constitutional interpretation. This Article endeavors to undermine those claims by demonstrating that, despite the suggestion of originalist rhetoric, originalism is not a single, coherent, unified theory of constitutional interpretation, but is rather a disparate collection of distinct constitutional theories that share little more than a misleading reliance on a common label. Originalists generally agree only on certain very broad precepts that serve as the fundamental underlying principles of constitutional interpretation: specifically, that the writtenness of the Constitution necessitates a fixed constitutional meaning, and that courts that see themselves as empowered to give the Constitution some avowedly different meaning are behaving contrary to law. Originalists have been able to achieve agreement on these broad underlying principles, but they have often viewed as unduly narrow and mistaken the understanding held by the original originalists-the framers of originalism, if you will-as to how those principles must be put into action. And originalists disagree so profoundly amongst themselves about how to effectuate those underlying principles that over time they have articulated-and continue to articulate-a wide array of strikingly disparate, and mutually exclusive, constitutional theories. In this regard, originalists have followed a living, evolving approach to constitutional interpretation. Our account of originalism\u27s evolution-and of the extensive disagreement among originalists today-undermines originalists\u27 normative claims about the superiority of their approach. Originalists\u27 claims about the unique and exclusive legitimacy of their theory-that originalism self-evidently represents the correct method of constitutional interpretation-founder when one considers that originalists themselves cannot even begin to agree on what their correct approach actually entails. And their claims that originalism has a unique ability to produce determinate and fixed constitutional meaning, and thus that only originalism properly treats the Constitution as law and properly constrains judges from reading their own values into the Constitution, stumble when one considers the rapid evolution and dizzying array of versions of originalism; because each version has the potential to produce a different constitutional meaning, the constitutional meaning that a committed originalist judge would find turns out to be anything but fixed. As originalism evolves, the constitutional meanings that it produces evolve along with it. Today\u27s originalists not only reach results markedly different from those originalists reached thirty years ago, but also produce widely divergent results amongst themselves. Judges committed to the originalist enterprise thus have significant discretion to choose (consciously or subconsciously) the version of originalism that is most likely to dictate results consistent with their own preferences. As such, originalism suffers from the very flaws that its proponents have identified in its alternatives

    Civil Procedure and the Ministerial Exception

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    In Hosanna-Tabor Evangelical Lutheran Church & School v. EEOC, the U.S. Supreme Court recognized a ministerial exception to the ordinary rules of employer liability. The Court also concluded that the exception operates as an affirmative defense rather than a jurisdictional bar. This conclusion raises quite significant questions about how courts should address the exception in the course of litigation. This Article posits that courts should approach these procedural questions in light of the underlying justification for the ministerial exception. The exception reflects a longstanding constitutional limitation on the competence of courts to resolve “strictly and purely ecclesiastical” questions. To conclude that the exception operates as an affirmative defense does not alter this fundamental limitation on the authority of secular courts. As a practical matter, this means that in litigation between religious institutions and their employees, courts may be required to manage discovery to resolve threshold questions about the application of the ministerial exception before permitting broader discovery. Similarly, courts should consider permitting interlocutory appeals of trial court decisions that deny motions for summary judgment based on the exception. And courts not only should conclude that religious institutions do not waive the defense by failing to raise it but also ought to raise it sua sponte when the facts indicate that the exception may apply. These departures from the ordinary treatment of affirmative defenses are necessary to respect the constitutional principles that the Court articulated in Hosanna-Tabor

    On the Statistics of Cognitive Radio Capacity in Shadowing and Fast Fading Environments (Journal Version)

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    In this paper we consider the capacity of the cognitive radio channel in different fading environments under a low interference regime. First we derive the probability that the low interference regime holds under shadow fading as well as Rayleigh and Rician fast fading conditions. We demonstrate that this is the dominant case, especially in practical cognitive radio deployment scenarios. The capacity of the cognitive radio channel depends critically on a power loss parameter, α\alpha, which governs how much transmit power the cognitive radio dedicates to relaying the primary message. We derive a simple, accurate approximation to α\alpha in Rayleigh and Rician fading environments which gives considerable insight into system capacity. We also investigate the effects of system parameters and propagation environment on α\alpha and the cognitive radio capacity. In all cases, the use of the approximation is shown to be extremely accurate.Comment: Submitted to the IEEE Transactions on Wireless Commun. The conference version of this paper appears in Proc. IEEE CrownCom, 200

    Promoting teacher–learner autonomy through and beyond initial language teacher education

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    With the growing international market for pre-experience MA in ELT/TESOL programmes, a key curriculum design issue is how to help students develop as learners of teaching through and beyond their formal academic studies. We report here on our attempts at the University of Warwick to address this issue, and consider wider implications for research and practice in initial language teacher education. At the Centre for Applied Linguistics at the University of Warwick, we run a suite of MA programmes for English language teaching professionals from around the world. Most of these courses are for students with prior teaching experience, but our MA in English Language Studies and Methods (ELSM) programme is designed for students with less than two years’ experience and, in fact, the majority enrol straight after completing their undergraduate studies in their home countries

    Decision making with decision event graphs

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    We introduce a new modelling representation, the Decision Event Graph (DEG), for asymmetric multistage decision problems. The DEG explicitly encodes conditional independences and has additional significant advantages over other representations of asymmetric decision problems. The colouring of edges makes it possible to identify conditional independences on decision trees, and these coloured trees serve as a basis for the construction of the DEG. We provide an efficient backward-induction algorithm for finding optimal decision rules on DEGs, and work through an example showing the efficacy of these graphs. Simplifications of the topology of a DEG admit analogues to the sufficiency principle and barren node deletion steps used with influence diagrams

    The Effect of Macrodiversity on the Performance of Maximal Ratio Combining in Flat Rayleigh Fading

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    The performance of maximal ratio combining (MRC) in Rayleigh channels with co-channel interference (CCI) is well-known for receive arrays which are co-located. Recent work in network MIMO, edge-excited cells and base station collaboration is increasing interest in macrodiversity systems. Hence, in this paper we consider the effect of macrodiversity on MRC performance in Rayleigh fading channels with CCI. We consider the uncoded symbol error rate (SER) as our performance measure of interest and investigate how different macrodiversity power profiles affect SER performance. This is the first analytical work in this area. We derive approximate and exact symbol error rate results for M-QAM/BPSK modulations and use the analysis to provide a simple power metric. Numerical results, verified by simulations, are used in conjunction with the analysis to gain insight into the effects of the link powers on performance.Comment: 10 pages, 5 figures; IEEE Transaction of Communication, 2012 Corrected typo

    Real-world Quantum Sensors: Evaluating Resources for Precision Measurement

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    Quantum physics holds the promise of enabling certain tasks with better performance than possible when only classical resources are employed. The quantum phenomena present in many experiments signify nonclassical behavior, but do not always imply superior performance. Quantifying the enhancement achieved from quantum behavior requires careful analysis of the resources involved. We analyze the specific case of parameter estimation using an optical interferometer, where increased precision can be achieved using quantum probe states. Common performance measures are examined and it is shown that some overestimate the improvement. For the simplest experimental case we compare the different measures and show this overestimate explicitly. We give the preferred analysis of real-world experiments and calculate benchmark values for experimental parameters necessary to realize a precision enhancement.Comment: 8 pages, 3 figure

    Performance Analysis of Dual-User Macrodiversity MIMO Systems with Linear Receivers in Flat Rayleigh Fading

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    The performance of linear receivers in the presence of co-channel interference in Rayleigh channels is a fundamental problem in wireless communications. Performance evaluation for these systems is well-known for receive arrays where the antennas are close enough to experience equal average SNRs from a source. In contrast, almost no analytical results are available for macrodiversity systems where both the sources and receive antennas are widely separated. Here, receive antennas experience unequal average SNRs from a source and a single receive antenna receives a different average SNR from each source. Although this is an extremely difficult problem, progress is possible for the two-user scenario. In this paper, we derive closed form results for the probability density function (pdf) and cumulative distribution function (cdf) of the output signal to interference plus noise ratio (SINR) and signal to noise ratio (SNR) of minimum mean squared error (MMSE) and zero forcing (ZF) receivers in independent Rayleigh channels with arbitrary numbers of receive antennas. The results are verified by Monte Carlo simulations and high SNR approximations are also derived. The results enable further system analysis such as the evaluation of outage probability, bit error rate (BER) and capacity.Comment: 24 pages, 7 figures; IEEE Transaction of Wireless Communication 2012 Corrected typo
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