1,515 research outputs found
Entropy rate calculations of algebraic measures
Let . We use a special class of translation invariant
measures on called algebraic measures to study the entropy rate
of a hidden Markov processes. Under some irreducibility assumptions of the
Markov transition matrix we derive exact formulas for the entropy rate of a
general state hidden Markov process derived from a Markov source corrupted
by a specific noise model. We obtain upper bounds on the error when using an
approximation to the formulas and numerically compute the entropy rates of two
and three state hidden Markov models
Elastocapillary instability under partial wetting conditions: bending versus buckling
The elastocapillary instability of a flexible plate plunged in a liquid bath
is analysed theoretically. We show that the plate can bend due to two separate
destabilizing mechanisms, when the liquid is partially wetting the solid. For
contact angles , the capillary forces acting tangential to
the surface are compressing the plate and can induce a classical buckling
instability. However, a second mechanism appears due to capillary forces normal
to surface. These induce a destabilizing torque that tends to bend the plate
for any value of the contact angle . We denote these mechanisms
as "buckling" and "bending" respectively and identify the two corresponding
dimensionless parameters that govern the elastocapillary stability. The onset
of instability is determined analytically and the different bifurcation
scenarios are worked out for experimentally relevant conditions.Comment: 12 pages, 13 figure
Information-theoretic temporal segmentation of video and applications: multiscale keyframes selection and shot boundaries detection
The first step in the analysis of video content is the partitioning of a long video sequence into short homogeneous temporal segments. The homogeneity property ensures that the segments are taken by a single camera and represent a continuous action in time and space. These segments can then be used as atomic temporal components for higher level analysis like browsing, classification, indexing and retrieval. The novelty of our approach is to use color information to partition the video into segments dynamically homogeneous using a criterion inspired by compact coding theory. We perform an information-based segmentation using a Minimum Message Length (MML) criterion and minimization by a Dynamic Programming Algorithm (DPA). We show that our method is efficient and robust to detect all types of transitions in a generic manner. A specific detector for each type of transition of interest therefore becomes unnecessary. We illustrate our technique by two applications: a multiscale keyframe selection and a generic shot boundaries detectio
Handling temporal heterogeneous data for content-based management of large video collections
Video document retrieval is now an active part of the domain of multimedia retrieval. However, unlike for other media, the management of a collection of video documents adds the problem of efficiently handling an overwhelming volume of temporal data. Challenges include balancing efficient content modeling and storage against fast access at various levels. In this paper, we detail the framework we have built to accommodate our developments in content-based multimedia retrieval. We show that not only our framework facilitates the development of processing and indexing algorithms but it also opens the way to several other possibilities such as rapid interface prototyping or retrieval algorithm benchmarking. Here, we discuss our developments in relation to wider contexts such as MPEG-7 and the TREC Video Trac
Can feature information interaction help for information fusion in multimedia problems?
This article presents the information-theoretic based feature information interaction, a measure that can describe complex feature dependencies in multivariate settings. According to the theoretical development, feature interactions are more accurate than current, bivariate dependence measures due to their stable and unambiguous definition. In experiments with artificial and real data we compare first the empirical dependency estimates of correlation, mutual information and 3-way feature interaction. Then, we present feature selection and classification experiments that show superior performance of interactions over bivariate dependence measures for the artificial data, for real world data this goal is not achieved ye
Moving on: Is Existenzminimum Still Relevant?
In the inter-war period, progressive architects confronted the building of mass housing with an analogy with rational and functional workplaces. At the 2nd CIAM (Congrès Internationaux d’Architecture Moderne), held in Frankfurt in 1929, this was tested against the formulation of space standards for a vital minimum, in order to increase the quantity of housing and reduce construction costs. This approach presumed the search for optimal living conditions and hygiene. The analogy with the world of work is particularly striking in the case of design of kitchens, removable furniture and storage spaces to maximize the use of space. In rational—and above all minimum—housing, the size of the rooms mainly depends on the size of the furniture. In this perspective, today in Switzerland new housing projects face the same issues, caused by a housing shortage that has plagued the country in the last decades. This suggests that Existenzminimum is still current for contemporary design
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