24,133 research outputs found

    Introduction to Library Trends 55 (3) Winter 2007: Libraries in Times of War, Revolution and Social Change

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    published or submitted for publicatio

    Indexed keyed connection Patent

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    Standard coupling design for mass productio

    Was the Accounting Profession Really That Bad?

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    To gain insight into the extent of malpractice in the State of California prior to the Passage of Sarbanes-Oxley, we examined the nature and magnitude of complains filed with the California Board of Accountancy (CBA) against both licensed and unlicensed accountants during the fiscal years 2000, 2001, and 2002. The CBA currently licenses and regulates over 73,000 licenses, with 1,431 complaints filed during the period reviewed. Disciplinary actions were taken against 283 different licensees for the three fiscal years reviewed. SEC issues were involved in 19 cases, theft or embezzlement 46 cases, public accounting malpractice 146 cases, improper retention of client records 11 cases, cheating on the CPA examination 9 cases, and miscellaneous other 52 cases. Over half of the complaints involved public accounting issues. Audit related complaints accounted for 48%, tax related complaints 36%, and compilations or reviews accounted for 16% of the complaints. These statistics were in line with the experience of the AICPA Professional Liability program. Within the above sections, the paper contains specifics with regards to the most common problems identified as a result of this work. While a number of interesting facts were discovered, one item of particularly interest was the significant number of claims that involved non-profit organizations. CBA administrators do not believe there is any greater tendency for non profit reporting versus for profit reporting, thus appearing to indicate this is just an area that has a greater possibility of accounting malpractice

    A study of early stopping, ensembling, and patchworking for cascade correlation neural networks

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    The constructive topology of the cascade correlation algorithm makes it a popular choice for many researchers wishing to utilize neural networks. However, for multimodal problems, the mean squared error of the approximation increases significantly as the number of modes increases. The components of this error will comprise both bias and variance and we provide formulae for estimating these values from mean squared errors alone. We achieve a near threefold reduction in the overall error by using early stopping and ensembling. Also described is a new subdivision technique that we call patchworking. Patchworking, when used in combination with early stopping and ensembling, can achieve an order of magnitude improvement in the error. Also presented is an approach for validating the quality of a neural network’s training, without the explicit use of a testing dataset

    Impact of pressure dissipation on fluid injection into layered aquifers

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    Carbon dioxide (CO2) capture and subsurface storage is one method for reducing anthropogenic CO2 emissions to mitigate climate change. It is well known that large-scale fluid injection into the subsurface leads to a buildup in pressure that gradually spreads and dissipates through lateral and vertical migration of water. This dissipation can have an important feedback on the shape of the CO2 plume during injection, and the impact of vertical pressure dissipation, in particular, remains poorly understood. Here, we investigate the impact of lateral and vertical pressure dissipation on the injection of CO2 into a layered aquifer system. We develop a compressible, two-phase model that couples pressure dissipation to the propagation of a CO2 gravity current. We show that our vertically integrated, sharp-interface model is capable of efficiently and accurately capturing water migration in a layered aquifer system with an arbitrary number of aquifers. We identify two limiting cases --- `no leakage' and `strong leakage' --- in which we derive analytical expressions for the water pressure field for the corresponding single-phase injection problem. We demonstrate that pressure dissipation acts to suppress the formation of an advancing CO2 tongue during injection, resulting in a plume with a reduced lateral extent. The properties of the seals and the number of aquifers determine the strength of pressure dissipation and subsequent coupling with the CO2 plume. The impact of pressure dissipation on the shape of the CO2 plume is likely to be important for storage efficiency and security

    Improving the performance of cascade correlation neural networks on multimodal functions

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    Intrinsic qualities of the cascade correlation algorithm make it a popular choice for many researchers wishing to utilize neural networks. Problems arise when the outputs required are highly multimodal over the input domain. The mean squared error of the approximation increases significantly as the number of modes increases. By applying ensembling and early stopping, we show that this error can be reduced by a factor of three. We also present a new technique based on subdivision that we call patchworking. When used in combination with early stopping and ensembling the mean improvement in error is over 10 in some cases

    An optimal factor analysis approach to improve the wavelet-based image resolution enhancement techniques

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    The existing wavelet-based image resolution enhancement techniques have many assumptions, such as limitation of the way to generate low-resolution images and the selection of wavelet functions, which limits their applications in different fields. This paper initially identifies the factors that effectively affect the performance of these techniques and quantitatively evaluates the impact of the existing assumptions. An approach called Optimal Factor Analysis employing the genetic algorithm is then introduced to increase the applicability and fidelity of the existing methods. Moreover, a new Figure of Merit is proposed to assist the selection of parameters and better measure the overall performance. The experimental results show that the proposed approach improves the performance of the selected image resolution enhancement methods and has potential to be extended to other methods

    A theoretical and experimental investigation of cylindrical electrostatic probes at arbitrary incidence in flowing plasma

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    The theory for calculating the current collected by a negatively biased cylindrical electrostatic probe at an arbitrary angle of attack in a weakley ionized flowing plasma is presented. The theory was constructed by considering both random and directed motion simultaneous with dynamic coupling of the flow properties and of the electric field of the probe. This direct approach yielded a theory that is more general than static plasma theories modified to account for flow. Theoretical calculations are compared with experimental electrostatic probe data obtained in the free stream of an arc-heated hypersonic wind tunnel. The theoretical calculations are based on flow conditions and plasma electron densities measured by an independent microwave interferometer technique. In addition, the theory is compared with laboratory and satellite data previously published by other investigators. In each case the comparison gives good agreement
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