Thèses sur le sujet « Colored strings »

Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2018.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 18).
Glass is a material that has been used for both practical and artistic purposes starting as early as the 1st century BC, and the stiffness of the glass affects how easy the glass is to work with. A three-point bending test was performed at 582°C (1080°F) for strips of transparent red, clear, black, transparent blue, and white glass. The deflection of the center point of each strip of glass was measured as the temperature was held constant. A proportional relationship of deflection with time was found for the red and white glass and the deflection of the clear, black, and blue glass was characterized by a parabolic relation. It was found that the red glass is the least stiff, followed by black, blue and clear, which have no statistically significant difference in stiffness, and finally the white glass was found to be the most stiff. These were contrary to the glass workers expectations, which was that black would be the least stiff. This will help glass workers know which colors will act similarly, and what to expect of different colors of glass.
by Or Oppenheimer.
S.B.

Thesis (Ed.D.)--Teachers College, Columbia University, 1996.
Issued also on microfilm. Includes tables. Sponsor: Lenore M. Pogonowski. Dissertation Committee: Harold F. Abeles. Includes bibliographical references (leaves 123-125).

Les trous noirs sont produits par effondrement gravitationnel d'étoiles supermassives et contiennent en leur centre une singularité de l'espace-temps habillée d'un horizon auquel rien ne peut s'échapper. Ils se situent à la frontière théorique commune entre la Relativité Générale et la Mécanique Quantique, ce qui en fait le principal laboratoire théorique et expérimental pour tester les théories quantiques de la gravité comme la Théorie des Cordes. L'entropie d'un trou noir est énorme, de l'ordre de sa masse au carré. Comme tout objet entropique, une description microscopique en termes de dégénérescence d'états devrait exister. De plus, le trou noir s'évapore par rayonnement d'Hawking et l'information à l'intérieur semble perdue, ce qui compromet la principe d'unitarité, pierre angulaire de la Mécanique Quantique. Par conséquent, la Théorie des Cordes doit fournir les degrés de liberté nécessaires pour décrire la nature de micro-état de trous noirs, elle doit également trouver un mécanisme résolvant la singularité et le paradoxe de la perte d'information. Cette thèse porte sur la physique des trous noirs à travers le "fuzzball proposal" et le "microstate geometry program". La majeure partie de la discussion se déroulera dans la limite de basse énergie de la Théorie des Cordes, c'est-à-dire en Supergravité. Le ``proposal" stipule qu'il existe "eS" solutions non singulières sans horizon qui ressemblent à un trou noir à large distance mais qui diffèrent à proximité de l'horizon. Sur la base de cette affirmation, la solution de trou noir classique correspond à la description statistique d'un système de solutions qui ont la même géométrie que le trou noir à l'extérieur de l'horizon, mais qui se terminent par des géométries régulières, dites "fuzzy". La proposition soulève plusieurs questions : Comment la singularité est-elle résolue ? De telles géométries peuvent-elles être construites en Supergravité ? Comment l'information s'échappe-t-elle de l'ensemble des micro-états ? La thèse est décomposée en trois parties. La première partie présente les bases et donne un aperçu du "microstate geometry program". La deuxième partie regroupe cinq travaux qui se consacrent à construire de larges familles de micro-états de trous noirs supersymétriques ou non supersymétriques. La dernière partie passe en revue deux travaux. L'un d'eux étudie le processus de diffusion dans les micro-états. Cela permet d'élucider comment le principe d'unicité est restaurée et comment l'information s'échappe des micro-états. La seconde traite du rôle des micro-états dans le contexte de la correspondance AdS2/CFT1 et donne l'ébauche d'une preuve pour le "fuzzball proposal"
Black holes are produced by gravitational collapse of supermassive stars and consist of a spacetime singularity dressed by a horizon from which nothing can escape. They lie at the common theoretical border between General Relativity and Quantum Mechanics, making them the main theoretical and experimental laboratory for testing quantum theories of gravity as String theory. The entropy of a black hole is huge, of the order of its mass squared. As any entropic object, a microscopic description in terms of large degeneracy of states should exist. Moreover, black hole evaporates through thermal Hawking's radiation and the information in the interior seems lost, that compromises the unitary principle, a cornerstone of Quantum Mechanics. Therefore, String Theory must provide the degrees of freedom necessary to describe the microstate nature of black holes, it must also find a mechanism resolving the singularity and the information loss paradox. This thesis addresses black-hole physics through the lens of the fuzzball proposal and the microstate geometry program. The major part of the discussion will be conducted in the low-energy limit of String Theory, that is in Supergravity. The proposal states that there exist "eS" horizonless non-singular solutions that resemble a black hole at large distance but differ in the vicinity of the horizon. Based on this statement, the classical black-hole solution corresponds to the average description of a system of solutions which match the black-hole geometry outside the horizon but cap off as ``fuzzy" smooth geometries in the infrared. The proposal leads to several questions: How is the singularity resolved? Can "eS" such geometries be built in Supergravity? How does the information escape from the ensemble of microstates?The thesis is decomposed in three parts. The first part introduces the basic materials and gives a review of the microstate geometry program. The second part gathers five works that all consist in constructing large classes of smooth horizonless microstate geometries of supersymmetric or non-supersymmetric black holes. The last part review two works. One is investigating the scattering process in microstate geometries. This helps to elucidate how unitarity is restored and how information escapes from black-hole backgrounds. The second one addresses the role of microstate geometries in the context of the AdS2/CFT1 correspondence and gives a beginning of proof for the fuzzball proposal

Les architectures par composants sont de plus en plus étudiées et utilisées pour le développement efficace des applications en génie logiciel. Elles offrent, d’un côté, une architecture claire aux développeurs, et de l’autre, une séparation des différentes parties fonctionnelles et en particulier dans les applications de visualisation scientifique interactives. La modélisation de ces applications doit permettre la description des comportements de chaque composant et les actions globales du système. De plus, les interactions entre composants s’expriment par des schémas de communication qui peuvent être très complexes avec, par exemple, la possibilité de perdre des messages pour gagner en performance. Cette thèse décrit le modèle ComSA (Component-based approach for Scientific Applications) qui est basé sur une approche par composants dédiée aux applications de visualisation scientifique interactive et dynamique formalisée par les réseaux FIFO colorés stricts (sCFN). Les principales contributions de cette thèse sont dans un premier temps, un ensemble d’outils pour modéliser les différents comportements des composants ainsi que les différentes politiques de communication au sein de l’application. Dans un second temps, la définition de propriétés garantissant un démarrage propre de l’application en analysant et détectant les blocages. Cela permet de garantir la vivacité tout au long de l’exécution de l’application. Finalement l’étude de la reconfiguration dynamique des applications d’analyse visuelle par ajout ou suppression à la volée d’un composant sans arrêter toute l’application. Cette reconfiguration permet de minimiser le nombre de services non disponibles
Component-based approaches are increasingly studied and used for the effective development of the applications in software engineering. They offer, on the one hand, safe architecture to developers, and on the other one, a separation of the various functional parts and particularly in the interactive scientific visualization applications. Modeling such applications enables the behavior description of each component and the global system’s actions. Moreover, the interactions between components are expressed through a communication schemes sometimes very complex with, for example, the possibility to lose messages to enhance performance. This thesis describes ComSA model (Component-based approach for Scientific Applications) that relies on a component-based approach dedicated to interactive and dynamic scientific visualization applications and its formalization in strict Colored FIFO Nets (sCFN). The main contributions of this thesis are, first, the definition of a set of tools to model the component’s behaviors and the various application communication policies. Second, providing some properties on the application to guarantee it starts properly. It is done by analyzing and detecting deadlocks. This ensures the liveness throughout the application execution. Finally, we present dynamic reconfiguration of visual analytics applications by adding or removing on the fly of a component without stopping the whole application. This reconfiguration minimizes the number of unavailable services

In recent years, the production of sequential data has been rapidly increasing. This requires solving challenging problems about how to represent information, how to retrieve information, and how to extract knowledge, from sequential data. These questions belong to the areas of coding, indexing, and mining, respectively. In this thesis, we investigate problems from those three areas. Coding refers to the way in which information is represented. Coding aims at generating optimal codes, that are codes having a minimum expected length. Codes can be generated for different purposes, from data compression to error detection/correction. The Lempel-Ziv 77 parsing produces an asymptotically optimal code in terms of compression. We study algorithms to efficiently decompress strings from the Lempel-Ziv 77 parsing, using memory proportional to the size of the parsing itself. We provide the first implementation of an algorithm by Bille et al., the only work we are aware of on this problem. We present a practical evaluation of this approach and several optimizations which improve the performance on all datasets we tested. Through the Ulam-R{'e}nyi game, it is possible to provide optimal adaptive error-correcting codes. The game consists of discovering an unknown $m$-bit number by asking membership questions the answers to which can be erroneous. Questions are formulated knowing the answers to all previous ones. We want to find an optimal strategy, i.e., a strategy that can identify any $m$-bit number using the theoretical minimum number of questions. We studied the case where questions are a union of up to a fixed number of intervals, and up to three answers can be erroneous. We first show that for any sufficiently large $m$, there exists a strategy to identify an initially unknown $m$-bit number which uses at most four intervals per question. We further refine our main tool to turn the above asymptotic result into a complete characterization of those instances of the Ulam-R{'e}nyi game that admit optimal strategies. Indexing refers to the way in which information is retrieved. An index for texts permits finding all occurrences of any substring, without traversing the whole text. Many applications require to look for approximate substrings. One of these is the problem of jumbled pattern matching, where two strings match if one is a permutation of the other. We study combinatorial aspects of prefix normal words, a class of binary words introduced in this context. These words can be used as indices for the Indexed Binary Jumbled Pattern Matching problem. We present a new recursive generation algorithm for prefix normal words that is competitive with the previous one but allows to list all prefix normal words sharing the same prefix. This sheds lights on novel insights that may help solving the problem of counting the number of prefix normal words of a given length. We then introduce infinite prefix normal words, and we show that one of the operations used by the algorithm, when repeatedly applied to extend a word, produces an infinite prefix normal word. This motivates the seeking for other operations that produce infinite prefix normal words. We found that one of these operations establishes a connection between prefix normal words and Sturmian words. We also explored the relationship between prefix normal words and Abelian complexity, as well as between prefix normal words and lexicographic order. Mining refers to the way in which information is converted into knowledge. The process of knowledge discovery covers several processing steps, including knowledge extraction. We analyze the problem of mining assertions for an embedded system from its simulation traces. This problem can be modeled as a pattern discovery problem on colored strings. We present two problems of pattern discovery on colored strings: patterns for one color only, or for all colors at the same time. We present two suffix tree-based algorithms. The first algorithm solves both the one color problem and the all colors problem. We then, introduce modifications which improve performance of the algorithm both on synthetic and on real data. We implemented and evaluated the proposed approaches, highlighting time trade-offs that can be obtained. A different way of knowledge extraction is based on the information-theoretic perspective of Pearl's model of causality. It has been postulated that the true causality direction between two phenomena A and B is related to the problem of finding the minimum entropy joint distribution between A and B. This problem is known to be NP-hard, and greedy algorithms have recently been proposed. We provide a novel analysis of one of the proposed heuristic showing that this algorithm guarantees an additive approximation of 1 bit. We then, provide a general criterion for guaranteeing an additive approximation factor of 1. This criterion may be of independent interest in other contexts where couplings are used.

碩士
國立交通大學
電機與控制工程系
89
Segmentation of pictures and texts is an important phase of document analysis,a good algorithm can make the result correcter or reduce processing time. According to the feature of colour information of digital documents, this task can be classified into two types: monochrome documents segmentation and color documents segmentation. Commonly, the components (text, picture, background)in color documents have uncertain colour, sometimes text string is embedded in color images. Because of these reasons, it is much more difficult to separate text from color documents than monochrome documents. We present a text segmentation scheme, using seven phases to deal with digital colour documents. This scheme is also useful for complicated documents, for example, text is embedded in color images or text string is skew. The seven phases are: 1.color clustering: classify image color according to several standard color; 2.detect edge and label block: use the result of edge detection to label block; 3.region growing: use the region growing rule to compensate small blocks; 4.color classification: classify the block according to color; 5.run length smoothing: merge the near block; 6.filter: extrace the text block; 7.profile projection: correct the skew text string . We uses Borland C++ Builder Language to accomplish the user interface and algorithm, the digital color documents are gotten by scanner. We use the OCR software to recognize our experimental results. Finally, we aim at the results to discuss.

碩士
國立清華大學
資訊工程學系
86
A color image retrieval method based on 2D strings is proposed in the study. We provide a friendly interface for users to specify a query picture by drawing the partial contents of desired images. First, at database creation, the color regions of each image in the database are extracted by block-based color segmentation. For each query picture, a color region grouping method is used to eliminate the light or shadow effects of segmented image and to adapt to various query pictures. Next, we obtain 2D strings to represent the spatial relationship among color regions of the query picture and segmented images. The similarity between the query picture and images in the database is defined as the length of the longest common sub-sequence of their corresponding 2D strings. Thus, images which are similar to the query picture can be retrieved from the database.

碩士
東吳大學
音樂學系
106
Since 20th century latter half, the East and West music culture in continues to collide mutually, to affect and in mutually unceasingly the union situation, regarding many Asian modern composer, no matter is in its growth East cultural context, perhaps is accepting the Western music culture the education or contacts the Western music culture the baptism. Not difficult to discover in its creation thought, the composing music technique, receives these two kind of music culture more or less the influence. Among them, not only fits nicely is lies in the Western music culture which appears them to track down inquiring about, is rooted in the Asian music culture importance. Although has respectively in its work creation style differently, respective varying degree fuses the East and West music culture connotation actually and next gathers. At present, has the small space Asian modern composers in the international musical world station, like on the century 80's second halves of, far go to the Ju Siao Song, Chen Yi, Tan Dun from China which American continuation music pursues advanced studies and so on. Becomes famous mostly in them in the work, not difficult to discover its writing technique between has one of mutually common characteristics, that was music performance fused the Western modern technique and the Chinese culture energetic connotation. For this paper to be studied,is precisely one has this characteristic string quartet "Eight Colors". After this first work was composer Tan Dun in 1986 studies abroad US, in Columbia University study music art doctorate period completed. Although was in vogue in at that time the Colombian academism twelve-tone writing, but composer's by no means came under this kind of writing style slightly influence, instead the diverse expression means let music fill the Western modern sound breath feeling. It is noteworthy that, in analyzes this work process, More notable is the composer to create the ingenious conception the behind, were as if more to fuse the Eastern music culture the Connotation, let music in the subtle change process, had charm and the natural rhythm ease flowing. In the work, in under the East and West culture fusion linguistic environment, most has the artistic charm place, the nothing better than timbre and the sound performance; At the same time, the constitution music text member, like the rhythm, the pitch also display the inseparable relation for the constitution music diversification. Therefore, in the research technique, this article first from the Tan Dun Life overview, the creation style as well as "Eight Colors for string quartet " the creation background mentions. Again from the timbre, the rhythm as well as the pitch related essential factor carries on discusses item by item.

The current study revisited the Competence vs Likeability preference in corporate context and in a team member selection task, introducing clothing color as potential implicit factor in this choice. To meet this purpose, two studies were conducted: study 1 counted with a total of 35 individuals and aimed to select the facial stimuli (from a subset of neutral and happy faces taken from the KDEF image base) that were most consistently perceived as those of competent or likeable individuals; study 2 was aimed at understanding how pink, blue and white impacted the decision-making process of choosing collaborators to work with. A total of 348 individuals participated in this second study. Study 1results showed that smiling individuals are perceived as likeable but not competent while not smiling ones are perceived non-likeable but competent. Pictures selected from study one’s most convergent targets in the Competence and Likeability attribution were manipulated to appear dressed either in pink, blue or white and distributed randomly in pairs of candidates to choose from. As expected according to previous studies, study 2 participants chose to work with likeability over competence. Was also expected that preferences on who to work with would be influenced by color gender stereotypes. Based on the assumption that violation of stereotype expectancy is unfavorable in impression formation, participants also confirmed hypotheses on the effect of color: when dressed in pink, competent targets were less chosen; they were, however chosen when dressed in white or blue.
Este estudo aborda o processo de tomada de decisão quando a escolha “competência ou agradabilidade” é apresentada em contextos empresariais, mais especificamente em situações de escolha de um colaborador para integrar uma equipa de trabalho. A esta escolha foi adicionada a cor da roupa do indivíduo como potencial influenciador da mesma. Para atender ao objetivo proposto foram realizados dois estudos: o estudo 1 que contou com um total de 35 indivíduos para selecionar os estímulos faciais (retirados de uma amostra de expressões contentes e neutras da base de imagens KDEF) que melhor representavam indivíduos competentes e indivíduos amáveis; já o estudo 2 foi realizado com o objetivo de compreender como é que as cores: cor de rosa, azul e branco, influenciam a escolha de com qual colaborador trabalhar. Participaram neste segundo estudo 348 indivíduos. Os resultados do estudo 1 evidenciam que os indivíduos com uma expressão facial sorridente foram percebidos como não competentes mas amáveis, enquanto os indivíduos não sorridentes foram percebidos como competentes, mas não amáveis. Assim, as imagens que melhor convergiram nas categorias de Competência e Agradabilidade eram manipuladas para gerar pares de potenciais colaboradores vestidos de cor de rosa, azul ou branco. Estes pares de colaboradores ilustraram a escolha de “Com quem trabalhar?” no estudo 2. Esperava-se que os estereótipos de género relacionados com a cor afectassem as escolhas, no sentido de desfavorecer os candidatos que violassem espectativas de cor. Os resultados foram ao encontro de resultados de estudos prévios: os participantes demonstraram preferência por trabalhar com um colaborador amável ao invés de um colaborador competente. Mais ainda, a hipótese de que a violação de expectativa relacionada com o estereotipo da atribuição de cor influencia o processo de formação de impressões foi verificada: quando os colaboradores se apresentavam vestidos de cor de rosa, os colaboradores competentes foram menos escolhidos; no entanto, estes foram escolhidos quando vestidos de azul ou branco.

碩士
國立臺北大學
通訊工程研究所
103
Large volume video analytics is a commonly discussed topic in the current digital age. Each industry has its own type of video data, and analyzing these video data is regarded as an essential procedure for detecting the relevant impact factors. Currently, Large volume video analytics involves various problems, such as problems in the pattern of video data and search performance. Addressing these problems is not only an industrial development requirement but also a relevant topic for academic research. This paper presents a rapid and accurate method for associative searching in big image data from security monitoring. The Full-Text searching method, which is now an entirely developed technique, searches the relevant image information in a massive image database. In addition, this paper proposes Color to String Transformation Analysis (CoSTA) for transforming a color feature into a text string of a continuous image object. Moreover, to help users find appropriate information from a large volume video database quickly and automatically, this video searching system provides a user interface for accelerating the search time.

碩士
元智大學
光電工程學系
106
LED strip lighting can provide high quality uniform shadow-free diffuse lighting at low cost as numerous emission sources are controlled by a single transformer. Organic LEDs offer the additional advantages of UV free emission and, for visible light communication, picosecond fluorescent lifetimes allowing the whole visible spectrum to be used without filters. Using parameters determined experimentally for solid-state LED strip lighting and fluorescent lifetimes typical of organic phosphors as the input for a Monte Carlo based ray-tracing simulation, we evaluate the potential bandwidths obtainable for indoor communication. Our work suggests that raw data transfer rates of 4 to 10 Mbps are obtainable in a standard 5m by 5m by 3m room compatible with Internet of Things (IoT) applications.

Text is no longer confined to scanned pages and often appears in camera-based images originating from text on real world objects. Unlike the images from conventional flatbed scanners, which have a controlled acquisition environment, camera-based images pose new challenges such as uneven illumination, blur, poor resolution, perspective distortion and 3D deformations that can severely affect the performance of any optical character recognition (OCR) system. Due to the variations in the imaging condition as well as the target document type, traditional OCR systems, designed for scanned images, cannot be directly applied to camera-captured images and a new level of processing needs to be addressed. In this thesis, we study some of the issues commonly encountered in camera-based image analysis and propose novel methods to overcome them. All the methods make use of color connected components. 1. Connected component descriptor for document image mosaicing Document image analysis often requires mosaicing when it is not possible to capture a large document at a reasonable resolution in a single exposure. Such a document is captured in parts and mosaicing stitches them into a single image. Since connected components (CCs) in a document image can easily be extracted regardless of the image rotation, scale and perspective distortion, we design a robust feature named connected component descriptor that is tailored for mosaicing camera-captured document images. The method involves extraction of a circular measurement region around each CC and its description using the angular radial transform (ART). To ensure geometric consistency during feature matching, the ART coefficients of a CC are augmented with those of its 2 nearest neighbors. Our method addresses two critical issues often encountered in correspondence matching: (i) the stability of features and (ii) robustness against false matches due to multiple instances of many characters in a document image. We illustrate the effectiveness of the proposed method on camera-captured document images exhibiting large variations in viewpoint, illumination and scale. 2. Font and background color independent text binarization The first step in an OCR system, after document acquisition, is binarization, which converts a gray-scale/color image into a two-level image -the foreground text and the background. We propose two methods for binarization of color documents whereby the foreground text is output as black and the background as white regardless of the polarity of foreground-background shades. (a) Hierarchical CC Analysis: The method employs an edge-based connected component approach and automatically determines a threshold for each component. It overcomes several limitations of existing locally-adaptive thresholding techniques. Firstly, it can handle documents with multi-colored texts with different background shades. Secondly, the method is applicable to documents having text of widely varying sizes, usually not handled by local binarization methods. Thirdly, the method automatically computes the threshold for binarization and the logic for inverting the output from the image data and does not require any input parameter. However, the method is sensitive to complex backgrounds since it relies on the edge information to identify CCs. It also uses script-specific characteristics to filter out edge components before binarization and currently works well for Roman script only. (b) Contour-based color clustering (COCOCLUST): To overcome the above limitations, we introduce a novel unsupervised color clustering approach that operates on a ‘small’ representative set of color pixels identified using the contour information. Based on the assumption that every character is of a uniform color, we analyze each color layer individually and identify potential text regions for binarization. Experiments on several complex images having large variations in font, size, color, orientation and script illustrate the robustness of the method. 3. Multi-script and multi-oriented text extraction from scene images Scene text understanding normally involves a pre-processing step of text detection and extraction before subjecting the acquired image for character recognition task. The subsequent recognition task is performed only on the detected text regions so as to mitigate the effect of background complexity. We propose a color-based CC labeling for robust text segmentation from natural scene images. Text CCs are identified using a combination of support vector machine and neural network classifiers trained on a set of low-level features derived from the boundary, stroke and gradient information. We develop a semiautomatic annotation toolkit to generate pixel-accurate groundtruth of 100 scenic images containing text in various layout styles and multiple scripts. The overall precision, recall and f-measure obtained on our dataset are 0.8, 0.86 and 0.83, respectively. The proposed method is also compared with others in the literature using the ICDAR 2003 robust reading competition dataset, which, however, has only horizontal English text. The overall precision, recall and f-measure obtained are 0.63, 0.59 and 0.61 respectively, which is comparable to the best performing methods in the ICDAR 2005 text locating competition. A recent method proposed by Epshtein et al. [1] achieves better results but it cannot handle arbitrarily oriented text. Our method, however, works well for generic scene images having arbitrary text orientations. 4. Alignment of curved text lines Conventional OCR systems perform poorly on document images that contain multi-oriented text lines. We propose a technique that first identifies individual text lines by grouping adjacent CCs based on their proximity and regularity. For each identified text string, a B-spline curve is fitted to the centroids of the constituent characters and normal vectors are computed along the fitted curve. Each character is then individually rotated such that the corresponding normal vector is aligned with the vertical axis. The method has been tested on a data set consisting of 50 images with text laid out in various ways namely along arcs, waves, triangles and a combination of these with linearly skewed text lines. It yields 95.9% recognition accuracy on text strings, where, before alignment, state-of-the-art OCRs fail to recognize any text. The CC-based pre-processing algorithms developed are well-suited for processing camera-captured images. We demonstrate the feasibility of the algorithms on the publicly-available ICDAR 2003 robust reading competition dataset and our own database comprising camera-captured document images that contain multiple scripts and arbitrary text layouts.