16,470 research outputs found
An Enhanced Method For Evaluating Automatic Video Summaries
Evaluation of automatic video summaries is a challenging problem. In the past
years, some evaluation methods are presented that utilize only a single feature
like color feature to detect similarity between automatic video summaries and
ground-truth user summaries. One of the drawbacks of using a single feature is
that sometimes it gives a false similarity detection which makes the assessment
of the quality of the generated video summary less perceptual and not accurate.
In this paper, a novel method for evaluating automatic video summaries is
presented. This method is based on comparing automatic video summaries
generated by video summarization techniques with ground-truth user summaries.
The objective of this evaluation method is to quantify the quality of video
summaries, and allow comparing different video summarization techniques
utilizing both color and texture features of the video frames and using the
Bhattacharya distance as a dissimilarity measure due to its advantages. Our
Experiments show that the proposed evaluation method overcomes the drawbacks of
other methods and gives a more perceptual evaluation of the quality of the
automatic video summaries.Comment: This paper has been withdrawn by the author due to some errors and
incomplete stud
Handwritten Digits Recognition using Deep Convolutional Neural Network: An Experimental Study using EBlearn
In this paper, results of an experimental study of a deep convolution neural
network architecture which can classify different handwritten digits using
EBLearn library are reported. The purpose of this neural network is to classify
input images into 10 different classes or digits (0-9) and to explore new
findings. The input dataset used consists of digits images of size 32X32 in
grayscale (MNIST dataset).Comment: This paper has been withdrawn by the author due to some errors and
incomplete stud
Searching for value relevance of book value and earnings: a case of premium vs. discount firms
We examine the premium/discount firm characteristic that fundamentally affects the value relevance of two key accounting line items, earnings and book values. We argue that from the perspective of both the residual income and option-style valuation models, the relative valuation roles of earnings and book values differ fundamentally between firms that trade at a premium vis-à-vis discount to book value. We find that book values play a significantly more important role in equity valuation than earnings when firms trade at a discount. We also find that other known influential conditions, such as the sign of earnings (Collins et al. 1999) or the relative levels of earnings and book value (Burgstahler and Dichev 1997), become inconsequential when the premium/discount condition of the firm is controlled for. The discovered relationships between the relative valuation roles of book values and earnings and the discount/premium characteristics of the firm are robust to the effect of time, information environment and the industry of the firm
Is the economic crisis over (and out)?
This note analyzes the recent global recession: its causes, the predictability of the timing of its start and of its end, and the implications for macro policy. These follow from the general-equilibrium macro model of Abadir and Talmain (2002) and its implications for a new type of macroeconometrics. The note also proposes some banking regulations, and presents prospects for the future.recession, recovery, causes and symptoms, turning points, prediction, macro policy
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Dispersion-engineered silicon nitride waveguides for mid-infrared supercontinuum generation covering the wavelength range 0.8-6.5 mu m
We numerically demonstrate the generation of a mid-infrared supercontinuum (SC) through the design of an on-chip complementary metal oxide semiconductor (CMOS) compatible 10-mm-long air-clad rectangular waveguide made using stoichiometric silicon nitride (Si 3 N 4 ) as the core and MgF 2 glass as its lower cladding. The proposed waveguide is optimized for pumping in both the anomalous and all-normal dispersion regimes. A number of waveguide geometries are optimized for pumping at 1.55 μ m with ultrashort pulses of 50-fs duration and a peak power of 5 kW. By initially keeping the thickness constant at 0.8 μ m, four different structures are engineered with varying widths between 3 μ m and 6 μ m. The largest SC spectral evolution covering a region of 0.8 μ m to beyond 6.5 μ m could be realized by a waveguide geometry with a width of 3 μ m. Numerical analysis shows that increasing width beyond 3 μ m by fixing thickness at 0.8 μ m results in a reduction of the SC extension in the long wavelength side. However, the SC spectrum can be enhanced beyond 6.5 μ m by increasing the waveguide thickness beyond 0.9 μ m with the same peak power and pump source. To the best of our knowledge, this is first time report of a broad SC spectral evolution through numerical demonstration in the mid-infrared region by the silicon nitride waveguide. In the case of all-normal dispersion pumping, a flatter SC spectra can be predicted with the same power and pump pulse but with a reduced bandwidth spanning 950–2100 nm
Many projectively unique polytopes
We construct an infinite family of 4-polytopes whose realization spaces have
dimension smaller or equal to 96. This in particular settles a problem going
back to Legendre and Steinitz: whether and how the dimension of the realization
space of a polytope is determined/bounded by its f-vector.
From this, we derive an infinite family of combinatorially distinct
69-dimensional polytopes whose realization is unique up to projective
transformation. This answers a problem posed by Perles and Shephard in the
sixties. Moreover, our methods naturally lead to several interesting classes of
projectively unique polytopes, among them projectively unique polytopes
inscribed to the sphere.
The proofs rely on a novel construction technique for polytopes based on
solving Cauchy problems for discrete conjugate nets in S^d, a new
Alexandrov--van Heijenoort Theorem for manifolds with boundary and a
generalization of Lawrence's extension technique for point configurations.Comment: 44 pages, 18 figures; to appear in Invent. mat
Macro and Financial Markets: The Memory of an Elephant?
Macroeconomic and aggregate financial series share an unconventional type of nonlinear dynamics. Existing techniques (like co-integration) model these dynamics incompletely, hence generating seemingly paradoxical results.
To avoid this, we provide a methodology to disentangle the long-run relation between variables from their own dynamics, and illustrate with two applications.
First, in the forward-premium puzzle, adding a component quantifying the persistent nonlinear dynamics of exchange rates yields substantial predictability and makes the forward-premium term insignificant. Second, S&P 500 grows in a pattern of momentum followed by reversal, forming long cycles around a trend given by GDP, a stable non-breaking relation since WWII.
Classification-Keywords:
On efficient simulation in dynamic models
Ways of improving the efficiency of Monte-Carlo (MC) techniques are studied for dynamic models. Such models cause the conventional Antithetic Variate (AV) technique to fail, and will be proved to reduce the benefit from using Control Variates with nearly nonstationary series. This paper suggests modifications of the two conventional variance reduction techniques to enhance their efficiency. New classes of AVs are also proposed. Methods of reordering innovations are found to do less well than others which rely on changing some signs in the spirit of the traditional AV. Numerical and analytical calculations are given to investigate the features of the proposed techniques. JEL classification code: C15 Key words: Dynamic models, Monte-Carlo (MC), Variance Reduction Technique (VRT), Antithetic Variate (AV), Control Variate (CV), Efficiency Gain (EG), Response Surface (RS).
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