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Exchanging 3D solid models across engineering applications has become increasingly important to integrated design environments (IDEs). However, transferring models among distributed locations via computer networks usually consumes...
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Exchanging 3D solid models across engineering applications has become increasingly important to integrated design environments (IDEs). However, transferring models among distributed locations via computer networks usually consumes large amounts of network bandwidth, requires powerful machines, and introduces potentially unacceptable latency. This paper presents a software framework to realize fast solid model exchange in IDEs. In particular, this framework integrates two key components: (a) incremental editing that allows solid models to be edited, modified, and propagated in an incremental form, and (b) progressive streaming that enables solid models to be stored, retrieved, transmitted, and reconstructed in a progressive manner. The benefits of this framework include obtaining real-time interaction with complex geometry, and obviating the burden of transferring large amounts of data over networks.
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We describe ZFITTER, a Fortran program based on a semi-analytical approach to fermion pair production in e~+e~- annihilation at a wide range of centre-of-mass energies, including the PETRA, TRISTAN, LEP1/SLC, and LEP2 energies. A ...
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We describe ZFITTER, a Fortran program based on a semi-analytical approach to fermion pair production in e~+e~- annihilation at a wide range of centre-of-mass energies, including the PETRA, TRISTAN, LEP1/SLC, and LEP2 energies. A flexible treatment of complete O(α) QED corrections and of some higher order contributions is made possible with three calculational chains containing different realistic sets of restrictions in the photon phase space. Numerical integrations are at most one-dimensional. Complete O(α) weak loop corrections supplemented by selected higher-order terms may be included. The program calculates Δr, the Z width, differential cross-sections, total cross-sections, integrated forward-backward asymmetries, left-right asymmetries, and for τ pair production also final-state polarization effects. Various interfaces allow fits to be performed with different sets of free parameters.
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In this thesis, we describe the one-way quantum computer (QC(C)), a scheme of universal quantum computation that consists entirely of one-qubit measurements on a highly entangled multiparticle state, i.e. the cluster state. We pro...
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In this thesis, we describe the one-way quantum computer (QC(C)), a scheme of universal quantum computation that consists entirely of one-qubit measurements on a highly entangled multiparticle state, i.e. the cluster state. We prove the universality of the QC(C), describe the underlying computational model and demonstrate that the QC(C) can be operated fault-tolerantly. In Sec. 2, we show that the QC(C) can be regarded as a simulator of quantum logic networks. In this way, we prove the universality and establish the link to the network model-the common model of quantum computation. We also indicate that the description of the QC(C) as a network simulator is not adequate in every respect. In Sec. 3, we derive the computational model underlying the QC(C), which is very different from the quantum logic network model. The QC(C) has no quantum input, no quantum output and no quantum register, and the unitary gates from some universal set are not the elementary building blocks of QC(C) quantum algorithms. Further, all information that is processed with the QC(C) is the outcomes of one-qubit measurements and thus processing of information exists only at the classical level. The QC(C) is nevertheless quantum-mechanical, as it uses a highly entangled cluster state as the central physical resource. In Sec. 4, we show that there exist nonzero error thresholds for fault-tolerant quantum computation with the QC(C). Further, we outline the concept of checksums in the context of the QC(C), which may become an element in future practical and adequate methods for fault-tolerant QC(C) computation.
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Understanding temporal processes and their correlations in time is of paramount importance for the development of near-term technologies that operate under realistic conditions. Capturing the complete multi-time statistics that de...
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Understanding temporal processes and their correlations in time is of paramount importance for the development of near-term technologies that operate under realistic conditions. Capturing the complete multi-time statistics that define a stochastic process lies at the heart of any proper treatment of memory effects. This is well understood in classical theory, where a hierarchy of joint probability distributions completely characterizes the process at hand. However, attempting to generalize this notion to quantum mechanics is problematic: observing realizations of a quantum process necessarily disturbs the state of the system, breaking an implicit, and crucial, assumption in the classical setting. This issue can be overcome by separating the experimental interventions from the underlying process, enabling an unambiguous description of the process itself and accounting for all possible multi-time correlations for any choice of interrogating instruments.
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Quantum states that are symmetric with respect to permutations of their subsystems appear in a wide range of physical settings, and they have a variety of promising applications in quantum information science. In this thesis, the ...
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Quantum states that are symmetric with respect to permutations of their subsystems appear in a wide range of physical settings, and they have a variety of promising applications in quantum information science. In this thesis, the entanglement of symmetric multipartite states is categorized, with a particular focus on the pure multi-qubit case and the geometric measure of entanglement. An essential tool for this analysis is the Majorana representation, a generalization of the single-qubit Bloch sphere representation, which allows for a unique representation of symmetric n-qubit states by n points on the surface of a sphere. Here this representation is employed to search for the maximally entangled symmetric states of up to 12 qubits in terms of the geometric measure, and an intuitive visual understanding of the upper bound on the maximal symmetric entanglement is given. Furthermore, it will be seen that the Majorana representation facilitates the characterization of entanglement equivalence classes such as stochastic local operations and classical communication (SLOCC) and the degeneracy configuration (DC). It is found that SLOCC operations between symmetric states can be described by the M?bius transformations of complex analysis, which allows for a clear visualization of the SLOCC freedoms and facilitates the understanding of SLOCC invariants and equivalence classes. In particular, explicit forms of representative states for all symmetric SLOCC classes of up to five qubits are derived. Well-known entanglement classification schemes such as the four qubit entanglement families or polynomial invariants are reviewed in the light of the results gathered here, which leads to sometimes surprising connections. Some interesting links and applications of the Majorana representation to related fields of mathematics and physics are also discussed.
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With a bit of effort, any technically skilled person can learn the latest information in their industry. That is so whether it concerns the design for a product, such as Apple''s iPod, or involves demand for a newly deployed servi...
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With a bit of effort, any technically skilled person can learn the latest information in their industry. That is so whether it concerns the design for a product, such as Apple''s iPod, or involves demand for a newly deployed service, such as municipal Wi-Fi in a distant city. Although industry conferences, consulting reports, and trade magazines have always informed market participants, today these sources are supplemented by Web pages and community or industry forums. Any reasonably sized product market attracts an abundance of product reviewers and bloggers who track gossip about business initiatives and point out design flaws or triumphs. This article focuses on market experiment phenomenon: commodifying and accumulating lessons must go hand in hand. While that observation may sound excessively abstract, it is grounded in the experience of many markets
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Segmentation of the video sequence by detecting shot changes is essential for video analysis, indexing and retrieval. In this context, a shot boundary detection algorithm is proposed in this paper based on the scale invariant feat...
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Segmentation of the video sequence by detecting shot changes is essential for video analysis, indexing and retrieval. In this context, a shot boundary detection algorithm is proposed in this paper based on the scale invariant feature transform (SIFT). The first step of our method consists on a top down search scheme to detect the locations of transitions by comparing the ratio of matched features extracted via SIFT for every RGB channel of video frames. The overview step provides the locations of boundaries. Secondly, a moving average calculation is performed to determine the type of transition. The proposed method can be used for detecting gradual transitions and abrupt changes without requiring any training of the video content in advance. Experiments have been conducted on a multi type video database and show that this algorithm achieves well performances.
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Mutually unbiased bases for quantum degrees of freedom are central to all theoretical investigations and practical exploitations of complementary properties. Much is known about mutually unbiased bases, but there are also a fair n...
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Mutually unbiased bases for quantum degrees of freedom are central to all theoretical investigations and practical exploitations of complementary properties. Much is known about mutually unbiased bases, but there are also a fair number of important questions that have not been answered in full as yet. In particular, one can find maximal sets of N+1 mutually unbiased bases in Hilbert spaces of prime-power dimension N = p~M, with p prime and m a positive integer,
and there is a continuum of mutually unbiased bases for a continuous degree of freedom, such as motion along a line. But not a single example of a maximal set is known if the dimension is another composite number (N= 6; 10; 12; . . .).
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Mutually unbiased bases for quantum degrees of freedom are central to all theoretical investigations and practical exploitations of complementary properties. Much is known about mutually unbiased bases, but there are also a fair n...
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Mutually unbiased bases for quantum degrees of freedom are central to all theoretical investigations and practical exploitations of complementary properties. Much is known about mutually unbiased bases, but there are also a fair number of important questions that have not been answered in full as yet. In particular, one can find maximal sets of N+1 mutually unbiased bases in Hilbert spaces of prime-power dimension N = p~M, with p prime and m a positive integer, and there is a continuum of mutually unbiased bases for a continuous degree of freedom, such as motion along a line. But not a single example of a maximal set is known if the dimension is another composite number (N= 6; 10; 12; . . .).
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One-way measurement based quantum computations (1WQC) may describe unitary transformations,via a composition of CPTP maps which are not all unitary themselves. This motivates the following decision problems. Is it possible to dete...
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One-way measurement based quantum computations (1WQC) may describe unitary transformations,via a composition of CPTP maps which are not all unitary themselves. This motivates the following decision problems. Is it possible to determine whether a \quantumto- quantum 1WQC procedure (having non-trivial input and output subsystems) performs a unitary transformation? Is it possible to describe precisely how such computations transform quantum states, by translation to a quantum circuit of comparable complexity? In this article, we present an e±cient algorithm for transforming certain families of measurement-based computations into a reasonable unitary circuit model, in particular without employing the principle of deferred measurement.
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