Finite weakly divisible nearrings

In [5] we dened and studied the algebraic structure called weakly divisible nearring (wd-nearring). In [1, 2] a special class of finite wd-nearrings on Z_{p^n}, p prime, was constructed: on the group (Z_{p^n}; +) of the residue classes (mod p^n) a multiplication "*" can be dened in such a way that (Z_{p^n};+; *) becomes a wd-nearring. Afterwards, in [3, 4] Partially Balanced Incomplete Block Designs (PBIBDs) and codes were obtained starting from the wd-nearrings of [1, 2] and formulae for computing their parameters could be derived just making use of the combinatorial properties of the constructed algebraic structure. In [9] the construction of [1, 2] was generalized to any wd-nearring. Applying Prop. 1 of [9], in Example 2.1 of this paper a wd-nearring N = (Z_7^2 ;+; *) is constructed on the elementary abelian group (Z_7^2 ; +) and a PBIBD is obtained from N. Using the algebraic properties of N = (Z_7^2 ;+; *), all the parameters of the PBIBD are computed. Since it seems reasonable to think the construction and the method to compute all the parameters in [3] could be extended to some additional classes of wd-nearrings, the aim of this paper is to study in more depth the algebraic structure of any finite wd-nearring, especially with regard to determining the size of the elements of signicant structures in N, as partitions, normal chains and products. In the next paragraph, the main definitions and properties of a finite wd-nearring are recalled (Remark 2.1) and the most signicant results presented in this paper are summarized (Remark 2.2)

Reducing Interconnect Cost in NoC through Serialized Asynchronous Links

This work investigates the application of serialization as a means of reducing the number of wires in NoC combined with asynchronous links in order to simplify the clocking of the link. Throughput is reduced but savings in routing area and reduction in power could make this attractiv

An Overview of Video Shot Clustering and Summarization Techniques for Mobile Applications

The problem of content characterization of video programmes is of great interest because video appeals to large audiences and its efficient distribution over various networks should contribute to widespread usage of multimedia services. In this paper we analyze several techniques proposed in literature for content characterization of video programmes, including movies and sports, that could be helpful for mobile media consumption. In particular we focus our analysis on shot clustering methods and effective video summarization techniques since, in the current video analysis scenario, they facilitate the access to the content and help in quick understanding of the associated semantics. First we consider the shot clustering techniques based on low-level features, using visual, audio and motion information, even combined in a multi-modal fashion. Then we concentrate on summarization techniques, such as static storyboards, dynamic video skimming and the extraction of sport highlights. Discussed summarization methods can be employed in the development of tools that would be greatly useful to most mobile users: in fact these algorithms automatically shorten the original video while preserving most events by highlighting only the important content. The effectiveness of each approach has been analyzed, showing that it mainly depends on the kind of video programme it relates to, and the type of summary or highlights we are focusing on

Interactive Video Mashup Based on Emotional Identity

The growth of new multimedia technologies has provided the user with the ability to become a videomaker, instead of being merely part of a passive audience. In such a scenario, a new generation of audiovisual content, referred to as video mashup, is gaining consideration and popularity. A mashup is created by editing and remixing pre-existing material to obtain a product which has its own identity and, in some cases, an artistic value itself. In this work we propose an emotional-driven interactive framework for the creation of video mashup. Given a set of feature movies as primary material, during the mixing task the user is supported by a selection of sequences belonging to different movies which share a similar emotional identity, defined through the investigation of cinematographic techniques used by directors to convey emotions

Using Content Analysis for Video Compression

This paper suggests the idea to model video information as a concatenation of different recurring sources. For each source a different tailored compressed representation can be optimally designed so as to best match the intrinsic characteristics of the viewed scene. Since in a video, a shot or scene with similar visual content recurs more than once, even at distant intervals in time, this enables to build a more compact representation of information. In a specific implementation of this idea, we suggest a content-based approach to structure video sequences into hierarchical summaries, and have each such summary represented by a tailored set of dictionaries of codewords. Vector quantization techniques, formerly employed for compression purposes only, have been here used first to represent the visual content of video shots and then to exploit visual-content redundancy inside the video. The depth in the hierarchy determines the precision in the representation both from a structural point of view and from a quality level in reproducing the video sequence. The effectiveness of the proposed method is demonstrated by preliminary tests performed on a limited collection of video-data excerpted from a feature movie. Some additional functionalities such as video skimming may remarkably benefit from this type of representation

A Connotative Space for Supporting Movie Affective Recommendation

The problem of relating media content to users’affective responses is here addressed. Previous work suggests that a direct mapping of audio-visual properties into emotion categories elicited by films is rather difficult, due to the high variability of individual reactions. To reduce the gap between the objective level of video features and the subjective sphere of emotions, we propose to shift the representation towards the connotative properties of movies, in a space inter-subjectively shared among users. Consequently, the connotative space allows to define, relate and compare affective descriptions of film videos on equal footing. An extensive test involving a significant number of users watching famous movie scenes, suggests that the connotative space can be related to affective categories of a single user. We apply this finding to reach high performance in meeting user’s emotional preferences

Text Driven Recognition of Multiple Faces in Newspapers

Face recognition is still a hard task when performed on newspaper images, since they often show faces in non-frontal poses, prohibitive lighting conditions, and too poor quality in terms of resolution. In these cases, combining textual information derived from the page articles with visual information proves to be advantageous for improving the recognition performance. In this work, we extract characters’ names from articles and captions to restrict facial recognition to a limited set of candidates. To solve the difficulties derived from having multiple faces in the same image, we also propose a solution that enables a joint assignment of faces to characters’ names. Extensive tests in both ideal and real scenarios confirm the soundness of the proposed approach

Gauge/gravity duality and the interplay of various fractional branes

We consider different types of fractional branes on a Z_2 orbifold of the conifold and analyze in detail the corresponding gauge/gravity duality. The gauge theory possesses a rich and varied dynamics, both in the UV and in the IR. We find the dual supergravity solution which contains both untwisted and twisted 3-form fluxes, related to what are known as deformation and N=2 fractional branes respectively. We analyze the resulting RG flow from the supergravity perspective, by developing an algorithm to easily extract it. We find hints of a generalization of the familiar cascade of Seiberg dualities due to a non-trivial interplay between the different types of fractional branes. We finally consider the IR behavior in several limits, where the dominant effective dynamics is either confining, in a Coulomb phase or runaway, and discuss the resolution of singularities in the dual geometric background.Comment: 38 pages + appendices, 15 figures; v2: refs added and typos correcte

A Survey of Multi-Source Energy Harvesting Systems

Energy harvesting allows low-power embedded devices to be powered from naturally-ocurring or unwanted environmental energy (e.g. light, vibration, or temperature difference). While a number of systems incorporating energy harvesters are now available commercially, they are specific to certain types of energy source. Energy availability can be a temporal as well as spatial effect. To address this issue, ‘hybrid’ energy harvesting systems combine multiple harvesters on the same platform, but the design of these systems is not straightforward. This paper surveys their design, including trade-offs affecting their efficiency, applicability, and ease of deployment. This survey, and the taxonomy of multi-source energy harvesting systems that it presents, will be of benefit to designers of future systems. Furthermore, we identify and comment upon the current and future research directions in this field

Identifying Video Content Consistency by Vector Quantization

Many post-production videos such as movies and cartoons present well structured story-lines organized in separated visual scenes. Accurate grouping of shots into these logical segments could lead to semantic indexing of scenes for interactive multimedia retrieval and video summaries. In this paper we introduce a novel shot-based analysis approach which aims to cluster together shots with similar visual content. We demonstrate how the use of codebooks of visual codewords (generated by a vector quantization process) represents an effective method to identify clusters containing shots with similar long-term consistency of chromatic compositions. The clusters, obtained by a single-link clustering algorithm, allow the further use of the well-known scene transition graph framework for logical story unit detection and pattern investigation