1,721,088 research outputs found
ReproducedPapers.org: Openly Teaching and Structuring Machine Learning Reproducibility
No full textWe present ReproducedPapers.org : an open online repository for teaching and structuring machine learning reproducibility. We evaluate doing a reproduction project among students and the added value of an online reproduction repository among AI researchers. We use anonymous self-assessment surveys and obtained 144 responses. Results suggest that students who do a reproduction project place more value on scientific reproductions and become more critical thinkers. Students and AI researchers agree that our online reproduction repository is valuable.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Pattern Recognition and BioinformaticsMultimedia ComputingComputer Science & Engineering-Teaching TeamInteractive IntelligenceSoftware EngineeringEmbedded SystemsCyber SecurityAlgorithmic
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Discrete optimization and stability index apply on stereoscopy into a road context
No full textLes tâches réalisées en traitement d'image tendent à devenir de plus en plus complexes. Par exemple, dans le contexte routier, les systèmes d'aide à la conduite, (Advanced driver-assistance systems), visent à une automatisation complète de la tâche de conduite. L’évaluation de la fiabilité représente un enjeu important pour ce type d’application. Face à la difficulté des tâches à réaliser, les chaînes de traitements sont souvent divisées en de nombreuses étapes de calculs de sorte qu'il est difficile de caractériser les sorties de la chaîne en fonction des perturbations des entrées. Les étapes du traitement consistent le plus souvent en des problèmes formulés comme la minimisation d'une énergie. Cette énergie est généralement difficile à optimiser, ce qui nécessite la mise en œuvre de méthodes d’optimisation adaptées. Dans cette thèse, nous cherchons à caractériser la solution d’un traitement à partir des calculs réalisés au cours de l’étape d'optimisation. Cette approche nous a permis de proposer des indices de stabilité de la solution dans le cadre de deux méthodes d’optimisation discrètes : la coupure de graphe et la programmation dynamique. Tout d’abord, nous nous sommes intéressés au problème de la reconstruction stéréoscopique en contexte routier et au dé-bruitage, dans le cadre de l’optimisation par coupure de graphe. Les modèles issus de l’interprétation bayésienne amènent à optimiser des énergies qui ne peuvent pas être traitées avec les schémas d’optimisation classiques par fusion binaire. Nous avons proposé un schéma adapté qui met en jeu des fusions binaires par expansion et par saut. L’application de ce schéma aux problèmes de la reconstruction stéréoscopique et au dé-bruitage, nous a permis d’obtenir des solutions possédant les caractéristiques que nous recherchions : des contours d’objets nets et des dégradés progressifs dans les zones homogènes. Ensuite, dans le contexte de la programmation dynamique, nous avons réinterprété l’a priori mis en jeu dans la méthode de reconstruction Semi-Global Matching ainsi que certaines de ses variantes. Nous avons proposé d’ajouter un paramètre à ces méthodes afin de modifier les directions privilégiées par l’a priori. Enfin, nous avons proposé des indices de stabilité de la solution dans le cadre de la coupure de graphe et de la programmation dynamique. La prise en compte de ces indices, dans une étape de raffinement des solutions, permet une amélioration des résultatsProblems solved by image processing tend to be more and more complex. For instance, in road context, ADAS (Advanced driver-assistance systems) aim to a completely automatic diving tack. Evaluating system reliability is an important challenge in that case. These tasks being hard to perform, processing chains are often divide in numerous processing steps. As a consequence, characterizing the output using the input of the chain is not obvious. Most of the time, image processing steps are formulate as an energy minimization. These energies are often hard to minimize and need to apply suitable optimization methods. In this thesis, we aim to characterize the solution during the optimization step. Using this approach, we proposed stability index with two discrete optimization methods : graph-cut and dynamic optimization. First, we focused on stereoscopic reconstruction problem in road context and on denoising problem using graph-cut. Models obtained by Bayesian interpretation lead to optimize energies witch cannot be handled by classical binary fusion optimization scheme. We proposed a suitable scheme composed of fusion by expansion and fusions by step. When this scheme is apply to stereoscopic reconstruction and denoising, obtained solution have the wanted characteristics : sharp edges and shading in homogeneous areas. Next, in dynamic programming context, we reinterpreted the prior used in Semi-Global Matching (SGM) stereoscopic reconstruction method and in some of its variants. We proposed an additional parameter in order to modify the favored direction in the prior. At last, we proposed stability index of the solution in graph-cut and dynamic programing context. Using this index in a solution refinement step shows improvement
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Towards high precision internal camera calibration
No full textCette thèse se concentre sur le sujet de la calibration de la camera interne et, en particulier, sur les aspects de haute précision. On suit et examine deux fils principaux: la correction d'une aberration chromatique de lentille et l'estimation des paramètres intrinsèques de la caméra. Pour la problème de l'aberration chromatique, on suit un chemin de post-traitement numérique de l'image, afin de se débarrasser des artefacts de couleur provoqués par le phénomène de dispersion du système d'objectif de la caméra, ce qui produit une désalignement perceptible des canaux couleur. Dans ce contexte, l'idée principale est de trouver un modèle de correction plus général pour réaligner les canaux de couleur que ce qui est couramment utilisé - différentes variantes du polynôme radial. Celui-ci ne peut pas être suffisamment général pour assurer la correction précise pour tous les types de caméras. En combinaison avec une détection précise des points clés, la correction la plus précise de l'aberration chromatique est obtenue en utilisant un modèle polynomial qui est capable de capter la nature physique du décalage des canaux couleur. Notre détection de points clés donne une précision allant jusqu'à 0,05 pixels, et nos expériences montrent sa grande résistance au bruit et au flou. Notre méthode de correction de l’aberration, par opposition aux logiciels existants, montre une géométrique résiduelle inférieure à 0,1 pixels, ce qui est la limite de la perception de la vision humaine. En ce qui concerne l'estimation des paramètres intrinsèques de la caméra, la question est de savoir comment éviter la compensation d'erreur résiduelle qui est inhérent aux méthodes globales d'étalonnage, dont le principe fondamental consiste à estimer tous les paramètres de la caméra ensemble - l'ajustement de faisceaux. Détacher les estimations de la distorsion de la caméra et des paramètres intrinsèques devient possible lorsque la distorsion est compensée séparément. Cela peut se faire au moyen de la harpe d'étalonnage, récemment développée, qui calcule le champ de distorsion en utilisant la mesure de la rectitude de cordes tendues dans différentes orientations. Une autre difficulté, étant donnée une image déjà corrigée de la distorsion, est de savoir comment éliminer un biais perspectif. Ce biais dû à la perspective est présent quand on utilise les centres de cibles circulaires comme points clés, et il s'amplifie avec l'augmentation de l'angle de vue. Afin d'éviter la modélisation de chaque cercle par une fonction conique, nous intégrons plutôt fonction de transformation affine conique dans la procédure de minimisation pour l'estimation de l'homographie. Nos expériences montrent que l'élimination séparée de la distorsion et la correction du biais perspectif sont efficaces et plus stables pour l'estimation des paramètres intrinsèques de la caméra que la méthode d'étalonnage globaleThis dissertation focuses on internal camera calibration and, especially, on its high-precision aspects. Two main threads are followed and examined: lens chromatic aberration correction and estimation of camera intrinsic parameters. For the chromatic aberration problem, we follow a path of digital post-processing of the image in order to get rid from the color artefacts caused by dispersion phenomena of the camera lens system, leading to a noticeable color channels misalignment. In this context, the main idea is to search for a more general correction model to realign color channels than what is commonly used - different variations of radial polynomial. The latter may not be general enough to ensure stable correction for all types of cameras. Combined with an accurate detection of pattern keypoints, the most precise chromatic aberration correction is achieved by using a polynomial model, which is able to capture physical nature of color channels misalignment. Our keypoint detection yields an accuracy up to 0.05 pixels, and our experiments show its high resistance to noise and blur. Our aberration correction method, as opposed to existing software, demonstrates a final geometrical residual of less than 0.1 pixels, which is at the limit of perception by human vision. When referring to camera intrinsics calculation, the question is how to avoid residual error compensation which is inherent for global calibration methods, the main principle of which is to estimate all camera parameters simultaneously - the bundle adjustment. Detachment of the lens distortion from camera intrinsics becomes possible when the former is compensated separately, in advance. This can be done by means of the recently developed calibration harp, which captures distortion field by using the straightness measure of tightened strings in different orientations. Another difficulty, given a distortion-compensated calibration image, is how to eliminate a perspective bias. The perspective bias occurs when using centers of circular targets as keypoints, and it gets more amplified with increase of view angle. In order to avoid modelling each circle by a conic function, we rather incorporate conic affine transformation function into the minimization procedure for homography estimation. Our experiments show that separate elimination of distortion and perspective bias is effective and more stable for camera's intrinsics estimation than global calibration metho
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