965 resultados para object modeling from images


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Manet security has a lot of open issues. Due to its character-istics, this kind of network needs preventive and corrective protection. Inthis paper, we focus on corrective protection proposing an anomaly IDSmodel for Manet. The design and development of the IDS are consideredin our 3 main stages: normal behavior construction, anomaly detectionand model update. A parametrical mixture model is used for behav-ior modeling from reference data. The associated Bayesian classi¯cationleads to the detection algorithm. MIB variables are used to provide IDSneeded information. Experiments of DoS and scanner attacks validatingthe model are presented as well.

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Painelajittelussa sellusta poistetaan epäpuhtauksia. Painelajittimien suunnittelussa on tärkeää ymmärtää lajittimessa tapahtuvia ilmiöitä. Työn tavoitteena oli kehittää kuvaamiseen perustuva mittausjärjestelmä kuitujen liikkeiden mittaamista varten. Mittauksen kohteena ovat sellusulpun kuitujen ja epäpuhtauksien nopeudet. Kuvaamisessa käytetyllä kaksoisvalotuksella pystytään mittaamaan kuitujen ja roskien nopeuksia. Nopeuksien mittaamiseen kuvista kehitettiin järjestelmä ja tutkittiin mahdollisuutta automatisoida mittaaminen. Yksittäisten kuitujen havaitsemiseen sellumassasta käytettiin optisella kirkasteella kirkastettuja kuituja ja UV-valoa. Kuituja värjättiin myös mustiksi ja kuvattiin näkyvällä valolla. Kaksoisvalotukseen käytettiin kahta stroboskooppia. Prosessin kuvaamisessa käytettiin ulkoisella herätteellä ohjattavaa kameraa. Kuvan tuomiseen kameralle ja kohteen valaistukseen käytettiin boroskooppia. Saatujen kuvien käsittelyä ja nopeuksien mittausta varten tehtiin tietokoneohjelma. Käytetyn boroskoopin valovoima ei ollut riittävä kuvausten suorittamiseen, mutta muilta osin laitteisto havaittiin toimivaksi. Kuitujen ja roskien nopeuksia pystyttiin laskemaan ohjelmalla kuvista, joita otettiin ilman boroskooppia. Mittaustiedon hankinnan automatisointi näyttää mahdolliselta tekemällä muutoksia kuvauslaitteistoon.

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The objective of industrial crystallization is to obtain a crystalline product which has the desired crystal size distribution, mean crystal size, crystal shape, purity, polymorphic and pseudopolymorphic form. Effective control of the product quality requires an understanding of the thermodynamics of the crystallizing system and the effects of operation parameters on the crystalline product properties. Therefore, obtaining reliable in-line information about crystal properties and supersaturation, which is the driving force of crystallization, would be very advantageous. Advanced techniques, such asRaman spectroscopy, attenuated total reflection Fourier transform infrared (ATR FTIR) spectroscopy, and in-line imaging techniques, offer great potential for obtaining reliable information during crystallization, and thus giving a better understanding of the fundamental mechanisms (nucleation and crystal growth) involved. In the present work, the relative stability of anhydrate and dihydrate carbamazepine in mixed solvents containing water and ethanol were investigated. The kinetics of the solvent mediated phase transformation of the anhydrate to hydrate in the mixed solvents was studied using an in-line Raman immersion probe. The effects of the operation parameters in terms of solvent composition, temperature and the use of certain additives on the phase transformation kineticswere explored. Comparison of the off-line measured solute concentration and the solid-phase composition measured by in-line Raman spectroscopy allowedthe identification of the fundamental processes during the phase transformation. The effects of thermodynamic and kinetic factors on the anhydrate/hydrate phase of carbamazepine crystals during cooling crystallization were also investigated. The effect of certain additives on the batch cooling crystallization of potassium dihydrogen phosphate (KDP) wasinvestigated. The crystal growth rate of a certain crystal face was determined from images taken with an in-line video microscope. An in-line image processing method was developed to characterize the size and shape of thecrystals. An ATR FTIR and a laser reflection particle size analyzer were used to study the effects of cooling modes and seeding parameters onthe final crystal size distribution of an organic compound C15. Based on the obtained results, an operation condition was proposed which gives improved product property in terms of increased mean crystal size and narrowersize distribution.

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Kandidaatintyö tehtiin osana PulpVision-tutkimusprojektia, jonka tarkoituksena on kehittää kuvapohjaisia laskenta- ja luokittelumetodeja sellun laaduntarkkailuun paperin valmistuksessa. Tämän tutkimusprojektin osana on aiemmin kehitetty metodi, jolla etsittiin kaarevia rakenteita kuvista, ja tätä metodia hyödynnettiin kuitujen etsintään kuvista. Tätä metodia käytettiin lähtökohtana kandidaatintyölle. Työn tarkoituksena oli tutkia, voidaanko erilaisista kuitukuvista laskettujen piirteiden avulla tunnistaa kuvassa olevien kuitujen laji. Näissä kuitukuvissa oli kuituja neljästä eri puulajista ja yhdestä kasvista. Nämä lajit olivat akasia, koivu, mänty, eukalyptus ja vehnä. Jokaisesta lajista valittiin 100 kuitukuvaa ja nämä kuvat jaettiin kahteen ryhmään, joista ensimmäistä käytettiin opetusryhmänä ja toista testausryhmänä. Opetusryhmän avulla jokaiselle kuitulajille laskettiin näitä kuvaavia piirteitä, joiden avulla pyrittiin tunnistamaan testausryhmän kuvissa olevat kuitulajit. Nämä kuvat oli tuottanut CEMIS-Oulu (Center for Measurement and Information Systems), joka on mittaustekniikkaan keskittynyt yksikkö Oulun yliopistossa. Yksittäiselle opetusryhmän kuitukuvalle laskettiin keskiarvot ja keskihajonnat kolmesta eri piirteestä, jotka olivat pituus, leveys ja kaarevuus. Lisäksi laskettiin, kuinka monta kuitua kuvasta löydettiin. Näiden piirteiden eri yhdistelmien avulla testattiin tunnistamisen tarkkuutta käyttämällä k:n lähimmän naapurin menetelmää ja Naiivi Bayes -luokitinta testausryhmän kuville. Testeistä saatiin lupaavia tuloksia muun muassa pituuden ja leveyden keskiarvoja käytettäessä saavutettiin jopa noin 98 %:n tarkkuus molemmilla algoritmeilla. Tunnistuksessa kuitujen keskimäärinen pituus vaikutti olevan kuitukuvia parhaiten kuvaava piirre. Käytettyjen algoritmien välillä ei ollut suurta vaihtelua tarkkuudessa. Testeissä saatujen tulosten perusteella voidaan todeta, että kuitukuvien tunnistaminen on mahdollista. Testien perusteella kuitukuvista tarvitsee laskea vain kaksi piirrettä, joilla kuidut voidaan tunnistaa tarkasti. Käytetyt lajittelualgoritmit olivat hyvin yksinkertaisia, mutta ne toimivat testeissä hyvin.

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Le Jeu, un phénomène difficile à définir, se manifeste en littérature de différentes manières. Le présent travail en considère deux : l’écriture à contrainte, telle que la pratique l’Oulipo, et l’écriture de l’imaginaire, en particulier les romans de Fantasy française. La première partie de cette étude présente donc, sous forme d’essai, les origines et les visées des deux groupes d’écrivains, mettant en lumière les similitudes pouvant être établies entre eux malgré leurs apparentes différences. Tandis que l’Oulipo cherche des contraintes capables de générer un nombre infini de textes et explore la langue par ce moyen, la Fantasy se veut créatrice de mondes imaginaires en puisant généralement à la source de Tolkien et des jeux de rôle. Il en résulte que le jeu, dans les deux cas, se révèle un puissant moteur de création, que le récit appelle un lecteur-explorateur et qu’il crée une infinité de mondes possibles. Malgré tout, des divergences demeurent quant à leurs critiques, leurs rapports avec le jeu et les domaines extralittéraires, et leurs visées. Considérant ce fait, je propose de combiner les deux styles d’écriture en me servant du cycle des Hortense de Jacques Roubaud (structuré au moyen de la sextine) et des Chroniques des Crépusculaires de Mathieu Gaborit (figure de proue en fantasy « pure »). Ce projet a pour but de combler le fossé restant encore entre les deux groupes. Ainsi, la seconde partie de mon travail constitue une première tentative de réunion des deux techniques d’écriture (à contrainte et de l’imaginaire). Six héros (trois aventuriers et trois mercenaires) partent à la recherche d’un objet magique dérobé à la Reine du Désert et capable de bouleverser l’ordre du monde. Le récit, divisé en six chapitres, rapporte les aventures de ce groupe jusqu’à leur rencontre avec l’ennemi juré de la Reine, un puissant sorcier elfe noir. Chaque chapitre comporte six sections plus petites où sont permutés – selon le mouvement de la sextine – six éléments caractéristiques des jeux de rôles : 1-Une description du MJ (Maître du Jeu) ; 2-Un combat ; 3-Une énigme à résoudre ou un piège à désarmer ; 4-Une discussion entre les joueurs à propos de leurs avatars ; 5-L’acquisition d’un nouvel objet ; 6-Une interaction avec un PNJ (Personnage Non Joueur). Tout au long du texte, des références aux Chroniques des Crépusculaires de Mathieu Gaborit apparaissent, suivant également un ordre sextinien. D’autres allusions, à Tolkien, Queneau, Perec ou Roubaud, agrémentent le roman.

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In recent years there is an apparent shift in research from content based image retrieval (CBIR) to automatic image annotation in order to bridge the gap between low level features and high level semantics of images. Automatic Image Annotation (AIA) techniques facilitate extraction of high level semantic concepts from images by machine learning techniques. Many AIA techniques use feature analysis as the first step to identify the objects in the image. However, the high dimensional image features make the performance of the system worse. This paper describes and evaluates an automatic image annotation framework which uses SURF descriptors to select right number of features and right features for annotation. The proposed framework uses a hybrid approach in which k-means clustering is used in the training phase and fuzzy K-NN classification in the annotation phase. The performance of the system is evaluated using standard metrics.

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El trabajo consiste en un estudio histórico y crítico de los mecanismos jurídicos de protección de las tierras de la población desplazada, en el cual se revisan las políticas públicas y la legislación que ha tenido incidencia en la materia. Así, partiendo de un breve estudio de los móviles que determinan el desplazamiento forzado, del cual concluye que la tierra ha sido un factor permanente y definitivo para el conflicto armado y el desplazamiento forzado, por lo cual se justifica abordar el desplazamiento forzado a partir de ella y la necesidad de protegerla, se adelanta un análisis crítico de las medidas que el Estado ha abordado para proteger a los desplazados en sus tierras, destacando la insuficiencia histórica del mismo, para finalmente plantear la necesidad de revaluar la política estatal al respecto.

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Este trabajo tiene como objetivo hacer una revisión teórica desde los inicios de la Teoría General de Sistemas, hasta el desarrollo de la dinámica de sistemas, todo lo que estas dos teorías plantean, además de muchas otras teorías de las cuales estas se encuentran rodeadas y conectadas muy cercanamente, ya que partiendo del planteamiento que hizo el biólogo Ludwig Von Bertalanffy se derivaron diversas corrientes de pensamiento, todas alrededor del enfoque y pensamiento de sistemas, y de la cual se deriva la más importante para nosotros en este trabajo de la cual es padre el Ingeniero Jay Wright Forrester, la Dinámica de Sistemas. Muchas de estas otras teorías tienen como objetivo generar estrategias de cambio en las organizaciones mediante diferentes metodologías, pero todas con el fin de alcanzar un desempeño óptimo en los procesos que son realizados en las organizaciones. Este proyecto es planteado ante la necesidad de tener un amplio conocimiento teórico de todo lo que conllevan los planteamientos de la Dinámica de Sistemas los cuales van de la mano junto con el pensamiento sistémico y el modelamiento organizacional, el cual veremos cómo es desarrollado desde el enfoque de la Dinámica de Sistemas a través de distintos modelos y en la actualidad herramientas informáticas tales como software diseñados exclusivamente para el modelamiento desde la Dinámica de Sistemas.

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This paper introduces perspex algebra which is being developed as a common representation of geometrical knowledge. A perspex can currently be interpreted in one of four ways. First, the algebraic perspex is a generalization of matrices, it provides the most general representation for all of the interpretations of a perspex. The algebraic perspex can be used to describe arbitrary sets of coordinates. The remaining three interpretations of the perspex are all related to square matrices and operate in a Euclidean model of projective space-time, called perspex space. Perspex space differs from the usual Euclidean model of projective space in that it contains the point at nullity. It is argued that the point at nullity is necessary for a consistent account of perspective in top-down vision. Second, the geometric perspex is a simplex in perspex space. It can be used as a primitive building block for shapes, or as a way of recording landmarks on shapes. Third, the transformational perspex describes linear transformations in perspex space that provide the affine and perspective transformations in space-time. It can be used to match a prototype shape to an image, even in so called 'accidental' views where the depth of an object disappears from view, or an object stays in the same place across time. Fourth, the parametric perspex describes the geometric and transformational perspexes in terms of parameters that are related to everyday English descriptions. The parametric perspex can be used to obtain both continuous and categorical perception of objects. The paper ends with a discussion of issues related to using a perspex to describe logic.

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Based on a series of collage made from images of mega yachts, the Future Monument looks at the possibility of taking late capitalism more seriously as an ideology than it takes itself seriously. The project asks whether the private display of wealth and power represented by the yacht can be appropriated for a new language of public sculpture. The choreographed live performance of the construction of the large scale monument was scripted to a proposed capitalist manifesto and took place in a public square in Herzliya, Israel. It aimed to articulate the ideology latent in capitalism’s claims to a neutral manifestation of human nature. The Future Monument project was developed through reading seminars taking place at Goldsmiths College, as part of a research strand headed by Pil and Galia Kollectiv on irony and overidentification within the Political Currency of Art research group. This research has so far produced a series of silk screen collage prints, a sculpture commissioned by the Essex Council and a live performance commissioned by the Herzliya Biennale. However, the project is ongoing, with future outputs planned including a curated exhibition and conference in 2012, in collaboration with Matthew Poole, Programme Director of the Centre for Curatorial Studies at the University of Essex.

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The passage of an electric current through graphite or few-layer graphene can result in a striking structural transformation, but there is disagreement about the precise nature of this process. Some workers have interpreted the phenomenon in terms of the sublimation and edge reconstruction of essentially flat graphitic structures. An alternative explanation is that the transformation actually involves a change from a flat to a three-dimensional structure. Here we describe detailed studies of carbon produced by the passage of a current through graphite which provide strong evidence that the transformed carbon is indeed three-dimensional. The evidence comes primarily from images obtained in the scanning transmission electron microscope using the technique of high-angle annular dark-field imaging, and from a detailed analysis of electron energy loss spectra. We discuss the possible mechanism of the transformation, and consider potential applications of “three-dimensional bilayer graphene”.

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Observers generally fail to recover three-dimensional shape accurately from binocular disparity. Typically, depth is overestimated at near distances and underestimated at far distances [Johnston, E. B. (1991). Systematic distortions of shape from stereopsis. Vision Research, 31, 1351–1360]. A simple prediction from this is that disparity-defined objects should appear to expand in depth when moving towards the observer, and compress in depth when moving away. However, additional information is provided when an object moves from which 3D Euclidean shape can be recovered, be this through the addition of structure from motion information [Richards, W. (1985). Structure from stereo and motion. Journal of the Optical Society of America A, 2, 343–349], or the use of non-generic strategies [Todd, J. T., & Norman, J. F. (2003). The visual perception of 3-D shape from multiple cues: Are observers capable of perceiving metric structure? Perception and Psychophysics, 65, 31–47]. Here, we investigated shape constancy for objects moving in depth. We found that to be perceived as constant in shape, objects needed to contract in depth when moving toward the observer, and expand in depth when moving away, countering the effects of incorrect distance scaling (Johnston, 1991). This is a striking example of the failure of shape con- stancy, but one that is predicted if observers neither accurately estimate object distance in order to recover Euclidean shape, nor are able to base their responses on a simpler processing strategy.

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This paper presents an automatic method to detect and classify weathered aggregates by assessing changes of colors and textures. The method allows the extraction of aggregate features from images and the automatic classification of them based on surface characteristics. The concept of entropy is used to extract features from digital images. An analysis of the use of this concept is presented and two classification approaches, based on neural networks architectures, are proposed. The classification performance of the proposed approaches is compared to the results obtained by other algorithms (commonly considered for classification purposes). The obtained results confirm that the presented method strongly supports the detection of weathered aggregates.

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Vegetation growing on railway trackbeds and embankments present potential problems. The presence of vegetation threatens the safety of personnel inspecting the railway infrastructure. In addition vegetation growth clogs the ballast and results in inadequate track drainage which in turn could lead to the collapse of the railway embankment. Assessing vegetation within the realm of railway maintenance is mainly carried out manually by making visual inspections along the track. This is done either on-site or by watching videos recorded by maintenance vehicles mainly operated by the national railway administrative body. A need for the automated detection and characterisation of vegetation on railways (a subset of vegetation control/management) has been identified in collaboration with local railway maintenance subcontractors and Trafikverket, the Swedish Transport Administration (STA). The latter is responsible for long-term planning of the transport system for all types of traffic, as well as for the building, operation and maintenance of public roads and railways. The purpose of this research project was to investigate how vegetation can be measured and quantified by human raters and how machine vision can automate the same process. Data were acquired at railway trackbeds and embankments during field measurement experiments. All field data (such as images) in this thesis work was acquired on operational, lightly trafficked railway tracks, mostly trafficked by goods trains. Data were also generated by letting (human) raters conduct visual estimates of plant cover and/or count the number of plants, either on-site or in-house by making visual estimates of the images acquired from the field experiments. Later, the degree of reliability of(human) raters’ visual estimates were investigated and compared against machine vision algorithms. The overall results of the investigations involving human raters showed inconsistency in their estimates, and are therefore unreliable. As a result of the exploration of machine vision, computational methods and algorithms enabling automatic detection and characterisation of vegetation along railways were developed. The results achieved in the current work have shown that the use of image data for detecting vegetation is indeed possible and that such results could form the base for decisions regarding vegetation control. The performance of the machine vision algorithm which quantifies the vegetation cover was able to process 98% of the im-age data. Investigations of classifying plants from images were conducted in in order to recognise the specie. The classification rate accuracy was 95%.Objective measurements such as the ones proposed in thesis offers easy access to the measurements to all the involved parties and makes the subcontracting process easier i.e., both the subcontractors and the national railway administration are given the same reference framework concerning vegetation before signing a contract, which can then be crosschecked post maintenance.A very important issue which comes with an increasing ability to recognise species is the maintenance of biological diversity. Biological diversity along the trackbeds and embankments can be mapped, and maintained, through better and robust monitoring procedures. Continuously monitoring the state of vegetation along railways is highly recommended in order to identify a need for maintenance actions, and in addition to keep track of biodiversity. The computational methods or algorithms developed form the foundation of an automatic inspection system capable of objectively supporting manual inspections, or replacing manual inspections.