1,721 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automatic video summaries.Comment: This paper has been withdrawn by the author due to some errors and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
A framework for quantitative analysis of user-generated spatial data
This paper proposes a new framework for automated
analysis of game-play metrics for aiding game designers
in finding out the critical aspects of the game caused
by factors like design modications, change in playing
style, etc. The core of the algorithm measures similarity
between spatial distribution of user generated in-game
events and automatically ranks them in order of importance. The feasibility of the method is demonstrated on
a data set collected from a modern, multiplayer First
Person Shooter, together with application examples of
its use. The proposed framework can be used to accompany traditional testing tools and make the game design
process more efficient
Using basic image features for texture classification
Representing texture images statistically as histograms over a discrete vocabulary of local features has proven widely effective for texture classification tasks. Images are described locally by vectors of, for example, responses to some filter bank; and a visual vocabulary is defined as a partition of this descriptor-response space, typically based on clustering. In this paper, we investigate the performance of an approach which represents textures as histograms over a visual vocabulary which is defined geometrically, based on the Basic Image Features of Griffin and Lillholm (Proc. SPIE 6492(09):1-11, 2007), rather than by clustering. BIFs provide a natural mathematical quantisation of a filter-response space into qualitatively distinct types of local image structure. We also extend our approach to deal with intra-class variations in scale. Our algorithm is simple: there is no need for a pre-training step to learn a visual dictionary, as in methods based on clustering, and no tuning of parameters is required to deal with different datasets. We have tested our implementation on three popular and challenging texture datasets and find that it produces consistently good classification results on each, including what we believe to be the best reported for the KTH-TIPS and equal best reported for the UIUCTex databases
On Measures of Behavioral Distance between Business Processes
The desire to compute similarities or distances between business processes arises in numerous situations such as when comparing business processes with reference models or when integrating business processes. The objective of this paper is to develop an approach for measuring the distance between Business Processes Models (BPM) based on the behavior of the business process only while abstracting from any structural aspects of the actual model. Furthermore, the measure allows for assigning more weight to parts of a process which are executed more frequently and can thus be considered as more important. This is achieved by defining a probability distribution on the behavior allowing the computation of distance metrics from the field of statistics
On mass-constraints implied by the relativistic precession model of twin-peak quasi-periodic oscillations in Circinus X-1
Boutloukos et al. (2006) discovered twin-peak quasi-periodic oscillations
(QPOs) in 11 observations of the peculiar Z-source Circinus X-1. Among several
other conjunctions the authors briefly discussed the related estimate of the
compact object mass following from the geodesic relativistic precession model
for kHz QPOs. Neglecting the neutron star rotation they reported the inferred
mass M_0 = 2.2 +/- 0.3 M_\sun. We present a more detailed analysis of the
estimate which involves the frame-dragging effects associated with rotating
spacetimes. For a free mass we find acceptable fits of the model to data for
(any) small dimensionless compact object angular momentum j=cJ/GM^2. Moreover,
quality of the fit tends to increase very gently with rising j. Good fits are
reached when M ~ M_0[1+0.55(j+j^2)]. It is therefore impossible to estimate the
mass without the independent knowledge of the angular momentum and vice versa.
Considering j up to 0.3 the range of the feasible values of mass extends up to
3M_\sun. We suggest that similar increase of estimated mass due to rotational
effects can be relevant for several other sources.Comment: 10 pages, 9 figures (in colour
Minimum Distance Estimation of Milky Way Model Parameters and Related Inference
We propose a method to estimate the location of the Sun in the disk of the
Milky Way using a method based on the Hellinger distance and construct
confidence sets on our estimate of the unknown location using a bootstrap based
method. Assuming the Galactic disk to be two-dimensional, the sought solar
location then reduces to the radial distance separating the Sun from the
Galactic center and the angular separation of the Galactic center to Sun line,
from a pre-fixed line on the disk. On astronomical scales, the unknown solar
location is equivalent to the location of us earthlings who observe the
velocities of a sample of stars in the neighborhood of the Sun. This unknown
location is estimated by undertaking pairwise comparisons of the estimated
density of the observed set of velocities of the sampled stars, with densities
estimated using synthetic stellar velocity data sets generated at chosen
locations in the Milky Way disk according to four base astrophysical models.
The "match" between the pair of estimated densities is parameterized by the
affinity measure based on the familiar Hellinger distance. We perform a novel
cross-validation procedure to establish a desirable "consistency" property of
the proposed method.Comment: 25 pages, 10 Figures. This version incorporates the suggestions made
by the referees. To appear in SIAM/ASA Journal on Uncertainty Quantificatio
An Automatic Similarity Detection Engine Between Sacred Texts Using Text Mining and Similarity Measures
Is there any similarity between the contexts of the Holy Bible and the Holy Quran, and can this be proven mathematically? The purpose of this research is using the Bible and the Quran as our corpus, we explore the performance of various feature extraction and machine learning techniques. The unstructured nature of text data adds an extra layer of complexity in the feature extraction task, and the inherently sparse nature of the corresponding data matrices makes text mining a distinctly difficult task. Among other things, We assess the difference between domain-based syntactic feature extraction and domain-free feature extraction, and then use a variety of similarity measures like Euclidean, Hillinger, Manhattan, cosine, Bhattacharyya, symmetries kullback-leibler, Jensen Shannon, probabilistic chi-square and clark. For a similarity to identify similarities and differences between sacred texts. Initially I started by comparing chapters of two raw text using the proximity measures to visualize their behaviors on high dimensional and spars space. It was apparent there was similarity between some of the chapters, but it was not conclusive. Therefore, there was a need to clean the noise using the so called Natural Language processing (NLP). For example, to minimize the size of two vectors, We initiated lists of similar vocabulary that worded differently in both texts but indicates the same exact meaning. Therefore, the program would recognize Lord as God in the Holy Bible and Allah as God in the Quran and Jacob as prophet in bible and Yaqub as a prophet in Quran. This process was completed many times to give relative comparisons on a variety of different words. After completion of the comparison of the raw texts, the comparison was completed for the processed text. The next comparison was completed using probabilistic topic modeling on feature extracted matrix to project the topical matrix into low dimensional space for more dense comparison. Among the distance measures intrdued to the sacred corpora, the analysis of similarities based on the probability based measures like Kullback leibler and Jenson shown the best result. Another similarity result based on Hellinger distance on the CTM also shows good discrimination result between documents. This work started with a believe that if there is intersection between Bible and Quran, it will be shown clearly between the book of Deuteronomy and some Quranic chapters. It is now not only historically, but also mathematically is correct to say that there is much similarity between the Biblical and Quranic contexts more than the similarity within the holy books themselves. Furthermore, it is the conclusion that distances based on probabilistic measures such as Jeffersyn divergence and Hellinger distance are the recommended methods for the unstructured sacred texts
The Burbea-Rao and Bhattacharyya centroids
We study the centroid with respect to the class of information-theoretic
Burbea-Rao divergences that generalize the celebrated Jensen-Shannon divergence
by measuring the non-negative Jensen difference induced by a strictly convex
and differentiable function. Although those Burbea-Rao divergences are
symmetric by construction, they are not metric since they fail to satisfy the
triangle inequality. We first explain how a particular symmetrization of
Bregman divergences called Jensen-Bregman distances yields exactly those
Burbea-Rao divergences. We then proceed by defining skew Burbea-Rao
divergences, and show that skew Burbea-Rao divergences amount in limit cases to
compute Bregman divergences. We then prove that Burbea-Rao centroids are
unique, and can be arbitrarily finely approximated by a generic iterative
concave-convex optimization algorithm with guaranteed convergence property. In
the second part of the paper, we consider the Bhattacharyya distance that is
commonly used to measure overlapping degree of probability distributions. We
show that Bhattacharyya distances on members of the same statistical
exponential family amount to calculate a Burbea-Rao divergence in disguise.
Thus we get an efficient algorithm for computing the Bhattacharyya centroid of
a set of parametric distributions belonging to the same exponential families,
improving over former specialized methods found in the literature that were
limited to univariate or "diagonal" multivariate Gaussians. To illustrate the
performance of our Bhattacharyya/Burbea-Rao centroid algorithm, we present
experimental performance results for -means and hierarchical clustering
methods of Gaussian mixture models.Comment: 13 page
Definition of an automated Content-Based Image Retrieval (CBIR) system for the comparison of dermoscopic images of pigmented skin lesions
<p>Abstract</p> <p>Background</p> <p>New generations of image-based diagnostic machines are based on digital technologies for data acquisition; consequently, the diffusion of digital archiving systems for diagnostic exams preservation and cataloguing is rapidly increasing. To overcome the limits of current state of art text-based access methods, we have developed a novel content-based search engine for dermoscopic images to support clinical decision making.</p> <p>Methods</p> <p>To this end, we have enrolled, from 2004 to 2008, 3415 caucasian patients and collected 24804 dermoscopic images corresponding to 20491 pigmented lesions with known pathology. The images were acquired with a well defined dermoscopy system and stored to disk in 24-bit per pixel TIFF format using interactive software developed in C++, in order to create a digital archive.</p> <p>Results</p> <p>The analysis system of the images consists in the extraction of the low-level representative features which permits the retrieval of similar images in terms of colour and texture from the archive, by using a hierarchical multi-scale computation of the Bhattacharyya distance of all the database images representation with respect to the representation of user submitted (query).</p> <p>Conclusion</p> <p>The system is able to locate, retrieve and display dermoscopic images similar in appearance to one that is given as a query, using a set of primitive features not related to any specific diagnostic method able to visually characterize the image. Similar search engine could find possible usage in all sectors of diagnostic imaging, or digital signals, which could be supported by the information available in medical archives.</p
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