5,874 research outputs found

    Scalable Noise Estimation with Random Unitary Operators

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    We describe a scalable stochastic method for the experimental measurement of generalized fidelities characterizing the accuracy of the implementation of a coherent quantum transformation. The method is based on the motion reversal of random unitary operators. In the simplest case our method enables direct estimation of the average gate fidelity. The more general fidelities are characterized by a universal exponential rate of fidelity loss. In all cases the measurable fidelity decrease is directly related to the strength of the noise affecting the implementation -- quantified by the trace of the superoperator describing the non--unitary dynamics. While the scalability of our stochastic protocol makes it most relevant in large Hilbert spaces (when quantum process tomography is infeasible), our method should be immediately useful for evaluating the degree of control that is achievable in any prototype quantum processing device. By varying over different experimental arrangements and error-correction strategies additional information about the noise can be determined.Comment: 8 pages; v2: published version (typos corrected; reference added

    Constrained Boundary Monitoring for Group Sequential Clinical Trials

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    Group sequential stopping rules are often used during the conduct of clinical trials in order to attain more ethical treatment of patients and to better address efficiency concerns. Because the use of such stopping rules materially affects the frequentist operating characteristics of the hypothesis test, it is necessary to choose an appropriate stopping rule during the planning of the study. It is often the case, however, that the number and timing of interim analyses are not precisely known at the time of trial design, and thus the implementation of a particular stopping rule must allow for flexible determination of the schedule of interim analyses. In this paper we consider the use of constrained stopping boundaries in the implementation of stopping rules. We compare this approach when used on various scales for the test statistic. When implemented on the scale of boundary crossing probabilities, this approach is identical to the error spending function approach of Lan & DeMets (1983)

    Pengembangan Ssistem Pembayaran Rekening Air pada Desa Bandar Baru

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    Penelitian ini membahas tentang pengembangan sistem pembayaran rekening air di desa Bandar Baru yang merupakan sebuah aplikasi berbasis web, dimana saat ini calon pelanggan baru di BUMDes Bandar baru melakukan pendaftaran secara langsung di kantor BUMDes Bndar baru sehingga tidak efisien, pembayaran tagihan juga masih tidak bisa dilihat melalui sistem karna belom adanya sistem yang telah dibuat oleh pihak BUMDes Bandar baru, BUMDes Bandar baru juga mengalami kesulitan dalam pengolahan adminstrasi karna masih diolah dalam bentuk word/exel, dan laporan-laporan bulanan juga masih blom dibuat, Maka dari masalah yang timbul solusi yang diajukan untuk mengatasi masalah tersebut adalah membangun sistem informasi pembayaran rekening air yang menggunakan bahasa pemrograman PHP dan MySQL sebagai databasenya. Sistem ini menyediakan kemudahan untuk pendaftaran, pengelolahan, pembayaran serta informasi lainnya bagi masyarakat di desa Bandar Baru. Bagi BUMDes Bandar Baru sistem ini merupakan sebuah kemudahan untuk menjalankan sistem yang sedang dijalankan saat ini sehingga lebih efisien, hemat waktu dan pekerjaan lebih mudah

    Observing biogeochemical cycles at global scales with profiling floats and gliders: prospects for a global array

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    Chemical and biological sensor technologies have advanced rapidly in the past five years. Sensors that require low power and operate for multiple years are now available for oxygen, nitrate, and a variety of bio-optical properties that serve as proxies for important components of the carbon cycle (e.g., particulate organic carbon). These sensors have all been deployed successfully for long periods, in some cases more than three years, on platforms such as profiling floats or gliders. Technologies for pH, pCO2, and particulate inorganic carbon are maturing rapidly as well. These sensors could serve as the enabling technology for a global biogeochemical observing system that might operate on a scale comparable to the current Argo array. Here, we review the scientific motivation and the prospects for a global observing system for ocean biogeochemistry

    Book Reviews

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    United Kingdom: Citizenship education in the United Kingdom: comparing England, Northern Ireland, Scotland and Wales

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    Purpose: In this country case study the authors undertake a comparative analysis of citizenship education across the four nations of the UK. The curriculum and contexts in England, Scotland, Wales and Northern Ireland are first described. Then the article considers how each national example engages with fundamental expectations of citizenship education, specifically in relation to questions of citizenship status and the relationship between citizens and the state; political identity; and active citizenship processes. Approach: Drawing on the authors’ collective experience and insights into policy and practice in each nation, we started with a ‘generative conversation’ to identify key issues for inclusion in this case study. Findings: The article unearths a variety of constraints and problems, and situates these in a broader policyscape in which policy accretion and policy approximation generate a permissive culture, which has undermined the promise of citizenship education as an entitlement for all young people

    Control Plane Compression

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    We develop an algorithm capable of compressing large networks into a smaller ones with similar control plane behavior: For every stable routing solution in the large, original network, there exists a corresponding solution in the compressed network, and vice versa. Our compression algorithm preserves a wide variety of network properties including reachability, loop freedom, and path length. Consequently, operators may speed up network analysis, based on simulation, emulation, or verification, by analyzing only the compressed network. Our approach is based on a new theory of control plane equivalence. We implement these ideas in a tool called Bonsai and apply it to real and synthetic networks. Bonsai can shrink real networks by over a factor of 5 and speed up analysis by several orders of magnitude.Comment: Extended version of the paper appearing in ACM SIGCOMM 201
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