324 research outputs found

    Off-diagonal geometric phase for mixed states

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    We extend the off-diagonal geometric phase [Phys. Rev. Lett. {\bf 85}, 3067 (2000)] to mixed quantal states. The nodal structure of this phase in the qubit (two-level) case is compared with that of the diagonal mixed state geometric phase [Phys. Rev. Lett. {\bf 85}, 2845 (2000)]. Extension to higher dimensional Hilbert spaces is delineated. A physical scenario for the off-diagonal mixed state geometric phase in polarization-entangled two-photon interferometry is proposed.Comment: small corrections; journal reference adde

    Adapting Quality Assurance to Adaptive Systems: The Scenario Coevolution Paradigm

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    From formal and practical analysis, we identify new challenges that self-adaptive systems pose to the process of quality assurance. When tackling these, the effort spent on various tasks in the process of software engineering is naturally re-distributed. We claim that all steps related to testing need to become self-adaptive to match the capabilities of the self-adaptive system-under-test. Otherwise, the adaptive system's behavior might elude traditional variants of quality assurance. We thus propose the paradigm of scenario coevolution, which describes a pool of test cases and other constraints on system behavior that evolves in parallel to the (in part autonomous) development of behavior in the system-under-test. Scenario coevolution offers a simple structure for the organization of adaptive testing that allows for both human-controlled and autonomous intervention, supporting software engineering for adaptive systems on a procedural as well as technical level.Comment: 17 pages, published at ISOLA 201

    Lower and upper bounds on the fidelity susceptibility

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    We derive upper and lower bounds on the fidelity susceptibility in terms of macroscopic thermodynamical quantities, like susceptibilities and thermal average values. The quality of the bounds is checked by the exact expressions for a single spin in an external magnetic field. Their usefulness is illustrated by two examples of many-particle models which are exactly solved in the thermodynamic limit: the Dicke superradiance model and the single impurity Kondo model. It is shown that as far as divergent behavior is considered, the fidelity susceptibility and the thermodynamic susceptibility are equivalent for a large class of models exhibiting critical behavior.Comment: 19 page

    Asymptotic estimation theory for a finite dimensional pure state model

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    The optimization of measurement for n samples of pure sates are studied. The error of the optimal measurement for n samples is asymptotically compared with the one of the maximum likelihood estimators from n data given by the optimal measurement for one sample.Comment: LaTeX, 23 pages, Doctoral Thesi

    A Component Framework for Java-based Real-time Embedded Systems

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    Rank (CORE): A.International audienceThe Real-Time Specification for Java (RTSJ) is becoming a popular choice in the world of real-time and embedded programming. However, RTSJ introduces many non-intuitive rules and restrictions which prevent its wide adoption. Moreover, current state-of-the-art frameworks usually fail to alleviate the development process into higher layers of the software development life-cycle. In this paper we extend our philosophy that RTSJ concepts need to be considered at early stages of software development, postulated in our prior work, in a framework that provides continuum between the design and implementation process. A component model designed specially for RTSJ serves here as a cornerstone. As the first contribution of this work, we propose a development process where RTSJ concepts are manipulated independently from functional aspects. Second, we mitigate complexities of RTSJ-development by automatically generating execution infrastructure where real-time concerns are transparently managed. We thus allow developers to create systems for variously constrained real-time and embedded environments. Performed benchmarks show that the overhead of the framework is minimal in comparison to manually written object-oriented approach, while providing more extensive functionality. Finally, the framework is designed with the stress on dynamic adaptability of target systems, a property we envisage as a fundamental in an upcoming era of massively developed real-time systems

    On quantum coding for ensembles of mixed states

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    We consider the problem of optimal asymptotically faithful compression for ensembles of mixed quantum states. Although the optimal rate is unknown, we prove upper and lower bounds and describe a series of illustrative examples of compression of mixed states. We also discuss a classical analogue of the problem.Comment: 23 pages, LaTe

    Hubungan Kelelahan Kerja dan Stress Kerja dengan Kecelakaan Kerja Tertusuk Jarum Jahit pada Pekerja Bagian Garmen di PT. Danliris Sukoharjo

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    Latar Belakang : Meningkatnya penggunaan teknologi di berbagai sektor usaha dapat pula mengakibatkan semakin tinggi resiko terjadinya kecelakaan kerja dan penyakit akibat kerja atau penyakit yang berhubungan dengan pekerjaan yang mengancam keselamatan, kesehatan dan kesejahteraan tenaga kerja. Dalam tiga tahun terakhir di PT. Danliris Sukoharjo, terjadi 38 kasus kecelakaan kerja tertusuk jarum jahit. Tujuan penelitian ini untuk mengetahui apakah kelelahan kerja dan stress kerja mempunyai hubungan dengan terjadinya kecelakaan kerja tertusuk jarum jahit. Metode : Penelitian ini menggunakan metode observasional analitik dengan rancangan cross sectional. Sampel diambil dengan metode simple random sampling sebanyak 200 pekerja bagian garmen. Pengumpulan data dilakukan dengan pengisian kuesioner kelelahan kerja dan stress kerja serta kecelakaan kerja tertusuk jarum jahit dilakukan dengan observasional. Pengolahan dan analisa data menggunakan uji statistik chi square dengan uji alterrnatif fisher. Hasil : Hasil penelitian ini menunjukkan tidak ada hubungan antara kelelahan kerja dengan terjadinya kecelakaan kerja tertusuk jarum jahit (p value 0.619) dan tidak ada hubungan antara stress kerja dengan kecelakaan kerja tertusuk jarum jahit (p value 0.137). Kesimpulan : Kelelahan kerja dan stress kerja tidak mempunyai hubungan dengan terjadinya kecelakaan kerja tertusuk jarum jahit. Kata Kunci : Kelelahan Kerja, Stress Kerja, Kecelakaan Kerj

    A priori probability that a qubit-qutrit pair is separable

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    We extend to arbitrarily coupled pairs of qubits (two-state quantum systems) and qutrits (three-state quantum systems) our earlier study (quant-ph/0207181), which was concerned with the simplest instance of entangled quantum systems, pairs of qubits. As in that analysis -- again on the basis of numerical (quasi-Monte Carlo) integration results, but now in a still higher-dimensional space (35-d vs. 15-d) -- we examine a conjecture that the Bures/SD (statistical distinguishability) probability that arbitrarily paired qubits and qutrits are separable (unentangled) has a simple exact value, u/(v Pi^3)= >.00124706, where u = 2^20 3^3 5 7 and v = 19 23 29 31 37 41 43 (the product of consecutive primes). This is considerably less than the conjectured value of the Bures/SD probability, 8/(11 Pi^2) = 0736881, in the qubit-qubit case. Both of these conjectures, in turn, rely upon ones to the effect that the SD volumes of separable states assume certain remarkable forms, involving "primorial" numbers. We also estimate the SD area of the boundary of separable qubit-qutrit states, and provide preliminary calculations of the Bures/SD probability of separability in the general qubit-qubit-qubit and qutrit-qutrit cases.Comment: 9 pages, 3 figures, 2 tables, LaTeX, we utilize recent exact computations of Sommers and Zyczkowski (quant-ph/0304041) of "the Bures volume of mixed quantum states" to refine our conjecture
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