3,232 research outputs found

    One Dimensional nnary Density Classification Using Two Cellular Automaton Rules

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    Suppose each site on a one-dimensional chain with periodic boundary condition may take on any one of the states 0,1,...,n10,1,..., n-1, can you find out the most frequently occurring state using cellular automaton? Here, we prove that while the above density classification task cannot be resolved by a single cellular automaton, this task can be performed efficiently by applying two cellular automaton rules in succession.Comment: Revtex, 4 pages, uses amsfont

    Variable frequency microwave (VFM) processing facilities and application in processing thermoplastic matrix composites

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    Microwave processing of materials is a relatively new technology advancement alternative that provides new approaches for enhancing material properties as well as economic advantages through energy savings and accelerated product development. Factors that hinder the use of microwaves in materials processing are declining, so that prospect for the development of this technology seem to be very promising. The two mechanisms of orientation polarisation and interfacial space charge polarisation, together with dc conductivity, form the basis of high frequency heating. Clearly, advantages in utilising microwave technologies for processing materials include penetration radiation, controlled electric field distribution and selective and volumetric heating. However, the most commonly used facilities for microwave processing materials are of fixed frequency, e.g. 2.45 GHz. This paper presents a state-of-the-art review of microwave technologies, processing methods and industrial applications, using variable frequency microwave (VFM) facilities. This is a new alternative for microwave processing

    Finding The Sign Of A Function Value By Binary Cellular Automaton

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    Given a continuous function f(x)f(x), suppose that the sign of ff only has finitely many discontinuous points in the interval [0,1][0,1]. We show how to use a sequence of one dimensional deterministic binary cellular automata to determine the sign of f(ρ)f(\rho) where ρ\rho is the (number) density of 1s in an arbitrarily given bit string of finite length provided that ff satisfies certain technical conditions.Comment: Revtex, uses amsfonts, 10 page

    Banach Analytic Sets and a Non-Linear Version of the Levi Extension Theorem

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    We prove a certain non-linear version of the Levi extension theorem for meromorphic functions. This means that the meromorphic function in question is supposed to be extendable along a sequence of complex curves, which are arbitrary, not necessarily straight lines. Moreover, these curves are not supposed to belong to any finite dimensional analytic family. The conclusion of our theorem is that nevertheless the function in question meromorphically extends along an (infinite dimensional) analytic family of complex curves and its domain of existence is a pinched domain filled in by this analytic family.Comment: 19 pages, This is the final version with significant corrections and improvements. To appear in Arkiv f\"or matemati

    Low-momentum ring diagrams of neutron matter at and near the unitary limit

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    We study neutron matter at and near the unitary limit using a low-momentum ring diagram approach. By slightly tuning the meson-exchange CD-Bonn potential, neutron-neutron potentials with various 1S0^1S_0 scattering lengths such as as=12070fma_s=-12070fm and +21fm+21fm are constructed. Such potentials are renormalized with rigorous procedures to give the corresponding asa_s-equivalent low-momentum potentials VlowkV_{low-k}, with which the low-momentum particle-particle hole-hole ring diagrams are summed up to all orders, giving the ground state energy E0E_0 of neutron matter for various scattering lengths. At the limit of as±a_s\to \pm \infty, our calculated ratio of E0E_0 to that of the non-interacting case is found remarkably close to a constant of 0.44 over a wide range of Fermi-momenta. This result reveals an universality that is well consistent with the recent experimental and Monte-Carlo computational study on low-density cold Fermi gas at the unitary limit. The overall behavior of this ratio obtained with various scattering lengths is presented and discussed. Ring-diagram results obtained with VlowkV_{low-k} and those with GG-matrix interactions are compared.Comment: 9 pages, 7 figure

    TreeGrad: Transferring Tree Ensembles to Neural Networks

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    Gradient Boosting Decision Tree (GBDT) are popular machine learning algorithms with implementations such as LightGBM and in popular machine learning toolkits like Scikit-Learn. Many implementations can only produce trees in an offline manner and in a greedy manner. We explore ways to convert existing GBDT implementations to known neural network architectures with minimal performance loss in order to allow decision splits to be updated in an online manner and provide extensions to allow splits points to be altered as a neural architecture search problem. We provide learning bounds for our neural network.Comment: Technical Report on Implementation of Deep Neural Decision Forests Algorithm. To accompany implementation here: https://github.com/chappers/TreeGrad. Update: Please cite as: Siu, C. (2019). "Transferring Tree Ensembles to Neural Networks". International Conference on Neural Information Processing. Springer, 2019. arXiv admin note: text overlap with arXiv:1909.1179

    Extracting semantic video objects

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    Dagan Feng2000-2001 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    On the cohomology of pseudoeffective line bundles

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    The goal of this survey is to present various results concerning the cohomology of pseudoeffective line bundles on compact K{\"a}hler manifolds, and related properties of their multiplier ideal sheaves. In case the curvature is strictly positive, the prototype is the well known Nadel vanishing theorem, which is itself a generalized analytic version of the fundamental Kawamata-Viehweg vanishing theorem of algebraic geometry. We are interested here in the case where the curvature is merely semipositive in the sense of currents, and the base manifold is not necessarily projective. In this situation, one can still obtain interesting information on cohomology, e.g. a Hard Lefschetz theorem with pseudoeffective coefficients, in the form of a surjectivity statement for the Lefschetz map. More recently, Junyan Cao, in his PhD thesis defended in Grenoble, obtained a general K{\"a}hler vanishing theorem that depends on the concept of numerical dimension of a given pseudoeffective line bundle. The proof of these results depends in a crucial way on a general approximation result for closed (1,1)-currents, based on the use of Bergman kernels, and the related intersection theory of currents. Another important ingredient is the recent proof by Guan and Zhou of the strong openness conjecture. As an application, we discuss a structure theorem for compact K{\"a}hler threefolds without nontrivial subvarieties, following a joint work with F.Campana and M.Verbitsky. We hope that these notes will serve as a useful guide to the more detailed and more technical papers in the literature; in some cases, we provide here substantially simplified proofs and unifying viewpoints.Comment: 39 pages. This survey is a written account of a lecture given at the Abel Symposium, Trondheim, July 201

    Supporting Pedagogical Practices Through the Interactive Learning Network (ILN)

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    Led by Mr. James Henri, Deputy Director of CITE, the IPPO project is co-investigated by six staff members of the Division of Information & Technology Studies. Like in the IPPO project, the seminar will be run as a team effort of the IPPO team.This seminar is co-organised with the Faculty of Education Research Office In this seminar, the speakers share with participants their experiences of implementing different online pedagogical practices using the ILN, the online learning support platform that CITE has developed. The speakers will draw on a collaborative action research project, the Innovative Pedagogical Practices Online (IPPO) project, funded by HKU SPACE Research Grant and launched early in 2003 within the Division of IT&S. Objectives of the study included investigating the learning styles of part-time students in the BEd ITE and LIS programs to enhance motivation and performance. Innovative practices were developed and trialed using the ILN platform to investigate how self-directed BEd students are in their learning. The ILN is a purpose built Content and Learner Management System allowing online delivery and access to materials. It is also a community-building environment where teachers/students work as teams and engage in reflective, collegial patterns of work. It facilitates both cognitive and social scaffolding, enabling educators and students to become progressively more involved in the community to sustain their commitment and interests. This environment is designed to support academic programs that rely heavily on pedagogies that emphasize the emergence and growth of autonomous, collaborative learning, rather than teacher-directed delivery of learning materials. This presentation will outline overall pedagogical design and showcase three examples of IPPO highlighting the ILN features used. The various approaches to integrating ILN to support pedagogy, peer and student-teacher interaction, and scaffolding will be demonstrated. Lecturers will provide an assessment of how well learning outcomes were achieved in their IPPO environments.published_or_final_versionCentre for Information Technology in Education, University of Hong Kon
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