Search results for "coding"

showing 10 items of 920 documents

Silhouette encoding and synthesis using elliptic Fourier descriptors and applications to videoconferencing, Journal of Visual Language and Computing

2004

This paper investigates the use of elliptic Fourier descriptors as a shape descriptor for encoding the silhouette of a person. Shape descriptors are here used for predicting the shape of silhouettes in missing frames within a sequence. This prediction scheme is applied to the case of generating in-between images in a low frame rate videoconferencing system, where the reconstructed silhouette is used as a binary mask for reducing the computational time for the frame reconstruction.

Settore INF/01 - InformaticaElliptical Fourier analysis silhouette Edge encoding Freeman chain.
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E-LEARNING AND ART OF PROGRAMMING: A CONTEXT ORIENTED TO

2017

Coding or programming is very important for a number of tasks and this is true not only in problem solving but also in the computer science and over. Many skills have to be acquired before to have a high familiarity degree with this science. In the studies for methods of coding, students have a great problem for understanding on how to solve and to develop algorithms in a rational way, thus the expertise on how to solve and to develop algorithms is the most difficult to acquire for all students in whatever age. This paper introduces the prototype of a framework able to running in the web space and to be supported by different devices and browsers, useful to integrate a number of collaborati…

Settore INF/01 - Informaticaframework iconic programming language open source problem solving visual coding.Computer sciencebusiness.industryE-learning (theory)Context (language use)Artificial intelligencebusinessEDULEARN proceedings
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Rateless Codes Performance Analysis in Correlated Channel Model for GEO Free Space Optics Downlinks

2012

Settore ING-INF/03 - TelecomunicazioniFree Space Optics (FSO) technologies for satellite communications offer several advantages: wide bandwidth high rate capability immunity to electromagnetic interference and small equipment size. Thus they are suitable for inter-satellite links deep space communications and also for high data rate ground-to-satellite/satellite-to-ground communications. Nevertheless FSO links suffer impairments that cause power signal degradation at the receiver. Scattering and absorption cause power signal attenuations predictable by suitable deterministic models. Optical turbulence causes random irradiance fluctuations which can generate signal fading events and can thereby only be predicted by statistical models. Attenuation and fading events can corrupt FSO links and so it would be recommended to add mitigation error codes on the communication link. FSO channel can be described as an erasure channel: fading events can cause erasure errors. We have identified in rateless codes (RCs) a suitable solution to be employed in FSO links. RCs do not need feedback and they add a redundant coding on the source data that allows the receiver to recover the whole payload despite erasure errors. We implemented two different of rateless codes: Luby Transform (LT) and Raptor. We analyzed their performances on a simulated turbulent GEO FSO downlink (1 Gbps - OOK modulation) at a 106 μm wavelength and for different values of zenith angles. Assuming a plane-wave propagation and employing Hufnagel-Valley we modeled the downlink using: 1) a temporal correlated channel model based on Gamma-Gamma probability distribution and 2) an irradiance covariance function that we converted on a time function using Taylor frozen eddies hypothesis. Our new channel model is able to simulate irradiance fluctuations at different turbulence conditions as it will be shown in the full paper. We will also report performance results of LT and Raptor codes at overhead range varying between 0 and 50% and for different values of source packets.Settore ING-INF/01 - Elettronica
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Clifford Rotors for Conceptual Representation in Chatbots

2013

In this abstract we introduce an unsupervised sub-symbolic natural language sentences encoding procedure aimed at catching and representing into a Chatbot Knowledge Base (KB) the concepts expressed by an user interacting with a robot. The chatbot KB is coded in a conceptual space induced from the application of the Latent Semantic Analysis (LSA) paradigm on a corpus of documents. LSA has the effect of decomposing the original relationships between elements into linearly-independent vectors. Each basis vector can be considered therefore as a "conceptual coordinate", which can be tagged by the words which better characterize it. This tagging is obtained by performing a (TF-IDF)-like weighting…

Settore ING-INF/05 - Sistemi Di Elaborazione Delle InformazioniDiscrete mathematicsComputer sciencebusiness.industryLatent semantic analysisInformationSystems_INFORMATIONSTORAGEANDRETRIEVALRepresentation (systemics)computer.software_genreChatbotGeometric algebraKnowledge baseArtificial IntelligenceEncoding (semiotics)chatbot clifford algebraArtificial intelligenceDialog systembusinesscomputerNatural language processingNatural language
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A New Class of Searchable and Provably Highly Compressible String Transformations

2019

The Burrows-Wheeler Transform is a string transformation that plays a fundamental role for the design of self-indexing compressed data structures. Over the years, researchers have successfully extended this transformation outside the domains of strings. However, efforts to find non-trivial alternatives of the original, now 25 years old, Burrows-Wheeler string transformation have met limited success. In this paper we bring new lymph to this area by introducing a whole new family of transformations that have all the "myriad virtues" of the BWT: they can be computed and inverted in linear time, they produce provably highly compressible strings, and they support linear time pattern search direc…

Settore ING-INF/05 - Sistemi Di Elaborazione Delle InformazioniFOS: Computer and information sciences050101 languages & linguisticsBurrows-wheeler transformation; Combinatorics on words; Data indexing and compression000 Computer science knowledge general worksSettore INF/01 - InformaticaCombinatorics on words05 social sciences02 engineering and technologyData_CODINGANDINFORMATIONTHEORYComputer ScienceBurrows-wheeler transformationComputer Science - Data Structures and Algorithms0202 electrical engineering electronic engineering information engineering020201 artificial intelligence & image processing0501 psychology and cognitive sciencesData Structures and Algorithms (cs.DS)Data indexing and compressionCombinatorics on word
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Bayesian System for Differential Cryptanalysis of DES

2014

AbstractThis paper proposes a new formalization for the differential cryptanalysis of DES (Data Encryption Standard) based on Bayesian Networks (BN), an artificial intelligence framework used for reasoning on data affected by uncertainty. Through the proposed approach it is possible to analyze DES from a novel point of view, thus paving the way for the development of a new class of cryptanalysis methods.

Settore ING-INF/05 - Sistemi Di Elaborazione Delle InformazioniNeural cryptographyTheoretical computer scienceDifferential cryptanalysisbusiness.industryBayesian probabilityBayesian networkCryptographyData_CODINGANDINFORMATIONTHEORYEncryptionDESlaw.inventionBayesian Networks;lawCryptographyBayesian NetworksPoint (geometry)Cryptanalysisbusinessdifferential cryptanalysiMathematicsdifferential cryptanalysisIERI Procedia
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The effects of mental rotation on computational thinking

2019

Abstract Although several investigations of spatial reasoning and mental rotation skills have been conducted in research areas linked to STEM education, to the best of our knowledge, few of these studies have examined the relationship between spatial reasoning and computational thinking. Given this gap in the literature, the present study investigates the role and action of spatial reasoning, and specifically the effects of mental rotation on computational thinking within an embodied and enacted perspective. To achieve this, we carried out a study involving 92 students in five primary-school classes (1st grade - 5th grade). The findings reveal a positive correlation between computational th…

Settore ING-INF/05 - Sistemi Di Elaborazione Delle InformazioniUnplugged codingGeneral Computer ScienceSettore INF/01 - InformaticaResearch areasComputational thinking05 social sciencesPerspective (graphical)050301 educationSpatial intelligenceMental rotationSTEMPositive correlation050105 experimental psychologyMental rotationEducationAction (philosophy)Embodied cognitionVisuospatial skillsComputational thinking Mental rotation STEM Unplugged coding Visuospatial skills0501 psychology and cognitive sciencesComputational thinkingPsychology0503 educationCognitive psychology
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A visual framework to support collaborative coding activities

2019

In this paper, we present a framework named SIRENE, a Web-based visual programming environment, where teachers and students can collaboratively interact, using a flexible and versatile definition of visual programming code instead of pre-established rules. After the description of the architecture of the SIRENE framework, the preliminary results of a pilot trial with secondary school students will be presented; these results will lead to the final remarks and directions for further developments.

Settore ING-INF/05 - Sistemi Di Elaborazione Delle InformazionicodingSettore INF/01 - Informaticabusiness.industryComputer sciencePilot trialcollaborative online programmingMultiparadigm languageArchitectureVisual programming frameworkSoftware engineeringbusinessCoding (social sciences)Visual programming language2019 29th Annual Conference of the European Association for Education in Electrical and Information Engineering (EAEEIE)
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A new algorithm for bit rate allocation in JPEG2000 tile encoding

2004

A new algorithm for allocating a given bit rate to different image tiles in the JPEG2000 encoding system is proposed. The algorithm outperforms other approaches commonly used in implementations. The new algorithm is suitable when information content is not equally distributed across the image. It is based on the computation of an index of the information content of each tile. To implement the proposed approach, we modified JasPer, a free software-based JPEG2000 coder implementation (Adams, M.D. and Kossentini, F., Proc. IEEE Int. Conf. on Image Process., vol.2, p.53-6, 2000). The experimentation was carried out on a subset of the JPEG2000 test images. Experimental results are reported, show…

Settore ING-INF/05 - Sistemi Di Elaborazione Delle Informazioniimage coding JPEG2000business.industryComputer scienceComputationComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISIONProcess (computing)computer.file_formatImage (mathematics)Softwarevisual_artEncoding (memory)JPEG 2000visual_art.visual_art_mediumTilebusinesscomputerAlgorithmData compression12th International Conference on Image Analysis and Processing, 2003.Proceedings.
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Ancora sulle "esplosive palatali" nelle inchieste dell'Atlante Linguistico del Mediterraneo (ALM): i punti albanesi

2021

Tra i «Problemi redazionali» emersi in fase di controllo e organizzazione dei materiali giunti dalla campagna di rilevamenti dell’Atlante Linguistico del Mediterraneo (ALM), Berruto (1971-1973) rileva la proliferazione e l’eterogeneità di alcune scelte grafemiche operate da diversi raccoglitori che, impegnati in una trascrizione più o meno puntuale delle risposte ottenute, avevano interpretato e risolto variamente alcune delle indicazioni previste nel sistema di trascrizione fonetica che accompagnava il Questionario. Particolarmente complesso era emerso il quadro relativo alla trascrizione di alcune consonanti del settore “palatale”, per le quali i grafemi (e i foni a essi corrispondenti) p…

Settore L-FIL-LET/12 - Linguistica ItalianaAmong the «Editorial problems» that emerged during the control and organization of the materials coming from the survey campaign of the Atlante Linguistico del Mediterraneo (ALM) Berruto (1971-1973) notes the proliferation and heterogeneity of some graphemic choices made by different field researchers. As they were engaged in a more or less punctual transcription of the answers obtained they had interpreted and solved differently some of the directions provided in the phonetic transcription system that accompanied the Questionnaire. The picture relating to the transcription of some consonants of the palatal sector had emerged as particularly complex since the graphemes (and the corresponding phones) foreseen in the original system (ALM 1959) were insufficient. Not even the 1971 updates meant to improve the representation of some phonetic features emerged from the investigations in the operations of Response reviewing allowed to obtain a clear homogeneous picture regarding the «plosive palatal» consonants. With regard to the phonetic trait under scrutiny I have already had the opportunity to propose a path aiming to the achievement of possible operational solutions. This has taken place in view of the planned simplification / homologation and transcoding phase from the ALM original system to the IPA one - while proceeding from the examination of the Schedoni’s current state with regard to the surveys referring to central-southern Italy Corsica and Sicily (see Matranga 2019). The scope is now to investigate the same phonetic trait as proven in the materials about the surveys carried out by Lirak Dodbiba in the ALM’s three Albanian points.
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