27,428 research outputs found

    Polynomial and rational solutions of holonomic systems

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    The aim of this paper is to give two new algorithms, which are elimination free, to find polynomial and rational solutions for a given holonomic system associated to a set of linear differential operators in the Weyl algebra D = k where k is a subfield of the complex numbers.Comment: 20 page

    Combining Stream Mining and Neural Networks for Short Term Delay Prediction

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    The systems monitoring the location of public transport vehicles rely on wireless transmission. The location readings from GPS-based devices are received with some latency caused by periodical data transmission and temporal problems preventing data transmission. This negatively affects identification of delayed vehicles. The primary objective of the work is to propose short term hybrid delay prediction method. The method relies on adaptive selection of Hoeffding trees, being stream classification technique and multilayer perceptrons. In this way, the hybrid method proposed in this study provides anytime predictions and eliminates the need to collect extensive training data before any predictions can be made. Moreover, the use of neural networks increases the accuracy of the predictions compared with the use of Hoeffding trees only

    A note on the steady-state response of an elastic half-space

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    With reference to the influence of local geology on earthquake ground motions, a more complete analytical formulation is made of the well-known problem of a horizontally stratified, linearly-elastic half-space subjected to vertically traveling, sinusoidal, plane waves. A more general interpretation of a result of Kanai is given, and a recursion formula is derived for computing amplification spectra. Some special properties of the system are pointed out and numerical examples are given

    Influence of local geology on earthquake ground motion

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    As a simplified approach for estimating theoretically the influence of local subsoils upon the ground motion during an earthquake, the problem of an idealized layered system subjected to vertically incident plane body waves was studied. Both the technique of steady-state analysis and the technique of transient analysis have been used to analyze the problem. In the steady-state analysis, a recursion formula has been derived for obtaining the response of a layered system to sinusoidally steady-state input. Several conclusions are drawn concerning the nature of the amplification spectrum of a nonviscous layered system having its layer stiffnesses increasing with depth. Numerical examples are given to demonstrate the effect of layer parameters on the amplification spectrum of a layered system. In the transient analysis, two modified shear beam models have been established for obtaining approximately the response of a layered system to earthquake -like excitation. The method of continuous modal analysis was adopted for approximate analysis of the models, with energy dissipation in the layers, if any, taken into account. Numerical examples are given to demonstrate the accuracy of the models and the effect of a layered system in modifying the input motion. Conditions are established, under which the theory is applicable to predict the influence of local subsoils on the ground motion during an earthquake. To demonstrate the applicability of the models to actual cases, three examples of actually recorded earthquake events are examined. It is concluded that significant modification of the incoming seismic waves, as predicted by the theory, is likely to occur in well defined soft subsoils during an earthquake, provided that certain conditions concerning the nature of the incoming seismic waves are satisfied

    Metamaterial with polarization and direction insensitive resonant transmission response mimicking electromagnetically induced transparency

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    We report on a planar metamaterial, the resonant transmission frequency of which does not depend on the polarization and angle of incidence of electromagnetic waves. The resonance results from the excitation of high-Q antisymmetric trapped current mode and shows sharp phase dispersion characteristic to Fano-type resonances of the electromagnetically induced transparency phenomenon

    An evaluation of implementing Koha in a Chinese language environment.

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    Purpose – The purpose of this paper is to evaluate issues of different scripts in the same record (in MARC21 and Chinese machine-readable cataloguing (CMARC)) and Chinese internal codes (i.e. double-byte character set) when implementing Koha. It also discusses successful efforts in promoting the adoption of Koha in Taiwan, particularly the contributions from Koha-Taiwan. Design/methodology/approach – A Koha CMARC/MARC21 testbed was set up to discuss issues of multi-scripts and Chinese internal codes when implementing Koha, and to determine to what extent the various features of CMARC, which are not present in MARC21, such as linking fields, can be supported in Koha and what is required to implement them if they are not available. Findings – In contrast to western characters, Chinese internal codes cause extra work, as special programming for character conversion is required when working with Koha. This situation is commonly seen in Asian countries such as China, Japan and Korea. This paper recommends implementing CMARC, MARC21 or even any other type of MARC format in Koha with strong commercial-level support. Practical implications – Koha-Taiwan serves Koha Chinese users around the world. A successful Koha-Taiwan could be a model around the world. Originality/value – In recent years, the concept of implementing an open-source library management system has been coming to the fore. In Taiwan, the local-based commercial library system covers more than one quarter of the library system market in academic libraries because the company provides better tailor-made support, mainly in scripts and multiple internal codes, than do western-based commercial library systems. Evaluations and conclusions from this paper will be useful to countries where multi-scripts and double-byte character sets are issues
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