25,859 research outputs found

    Institutional Choice and Targeted Killing: A Comparative Perspective

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    For over a decade, the use of targeted killing has been one of the most controversial issues in counterterrorism policy and law. One longstanding debate over this tactic concerns the allocation of decision-making and oversight authority among the branches of government. As attempts to settle this debate through textual and historical sources yield indeterminant answers, scholars tend to examine them through a functionalist prism, asking what institutional structures best serve the interests of national security while ensuring adequate accountability and preventing unnecessary force. This article, retaining that functionalist framing of that issue, will approach the question through a comparative law analysis. Three of the countries most heavily engaged in global counterterrorism—the U.S., the U.K., and Israel—have adopted substantially different approaches for regulating counterterrorism targeting, each according a primary supervisory role to a different governmental actor: the Executive in the U.S., Parliament in the U.K., and the Judiciary in Israel. This article describes, compares, and critically analyzes these approaches. Drawing on comparative institutional analysis theory, it then examines the findings and reaches three main conclusions. First, that in light of the judiciary’s unique structural perspective and expertise, some judicial involvement in developing the legal standard that guides and constrains government action is desirable. Second, that suboptimal decision-making and illegality due to executive bias are more likely to occur where the executive is accountable only to its own internal oversight mechanisms. And third, that in both presidential and parliamentarian systems, legislators do not have and are unlikely to have any sort of meaningful influence on executive behavior in this domain. The article concludes by suggesting a few possible institutional reforms

    On cyclic numbers and an extension of Midy's theorem

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    In this note we consider fractions of the form 1/m and their floating-point representation in various arithmetic bases. For instance, what is 1/7 in base 2005? And, what about 1/4? We give a simple algorithm to answer these questions. In addition, we discuss an extension of Midy's theorem whose proof relies on elementary modular arithmetic.Comment: 6 pages, aimed at undergraduate student

    Time-scales of Radio Emission in PSR J0437-4715 at 327 MHz

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    Time-scales of radio emission are studied in PSR J0437-4715 at 327 MHz using almost half a million periods of high quality data from Ooty Radio Telescope. The radio emission in this milli second pulsar occurs on a short (s) time-scale of approximately 0.026 +- 0.001 periods, and on a (l) time-scale that is much longer than the widths of the components of the integrated profile (approximately 0.05 periods). The width of the s emission increases with its increasing relative contribution to the total radio emission. This may provide constraints for the details of discharge of vacuum gaps above pulsar polar caps. The s emission occasionally takes place in the form of intense spikes, which are confined to the main component of the integrated profile for 90 per cent of the time. The positions of spikes within a component of the integrated profile have no simple relation to the shape of that component. This may have impact on the interpretation of the integrated profile components in terms of independent regions of emission on the polar cap.Comment: Accepted for publication in Vol 543 (1 Nov 2000) of The Astrophysical Journa

    Spark Model for Pulsar Radiation Modulation Patterns

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    A non-stationary polar gap model first proposed by Ruderman & Sutherland (1975) is modified and applied to spark-associated pulsar emission at radio wave-lengths. It is argued that under physical and geometrical conditions prevailing above pulsar polar cap, highly non-stationary spark discharges do not occur at random positions. Instead, sparks should tend to operate in well determined preferred regions. At any instant the polar cap is populated as densely as possible with a number of two-dimensional sparks with a characteristic dimension as well as a typical distance between adjacent sparks being about the polar gap height. Our model differs, however, markedly from its original 'hollow cone' version. The key feature is the quasi-central spark driven by pair production process and anchored to the local pole of a sunspot-like surface magnetic field. This fixed spark prevents the motion of other sparks towards the pole, restricting it to slow circumferential drift across the planes of field lines converging at the local pole. We argue that the polar spark constitutes the core pulsar emission, and that the annular rings of drifting sparks contribute to conal components of the pulsar beam. We found that the number of nested cones in the beam of typical pulsar should not excced three; a number also found by Mitra & Deshpande (1999) using a completely different analysis.Comment: 31 pages, 8 figures, accepted by Ap

    The Morse-Sard theorem revisited

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    Let n,m,kn, m, k be positive integers with k=nm+1k=n-m+1. We establish an abstract Morse-Sard-type theorem which allows us to deduce, on the one hand, a previous result of De Pascale's for Sobolev Wlock,p(Rn,Rm)W^{k,p}_{\textrm{loc}}(\mathbb{R}^n, \mathbb{R}^m) functions with p>np>n and, on the other hand, also the following new result: if fCk1(Rn,Rm)f\in C^{k-1}(\mathbb{R}^n, \mathbb{R}^m) satisfies lim suph0Dk1f(x+h)Dk1f(x)h<\limsup_{h\to 0}\frac{|D^{k-1}f(x+h)-D^{k-1}f(x)|}{|h|}<\infty for every xRnx\in\mathbb{R}^n (that is, Dk1fD^{k-1}f is a Stepanov function), then the set of critical values of ff is Lebesgue-null in Rm\mathbb{R}^m. In the case that m=1m=1 we also show that this limiting condition holding for every xRnNx\in\mathbb{R}^n\setminus\mathcal{N}, where N\mathcal{N} is a set of zero (n2+α)(n-2+\alpha)-dimensional Hausdorff measure for some 0<α<10<\alpha<1, is sufficient to guarantee the same conclusion.Comment: We corrected some misprints and made some changes in the introductio
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