1,435 research outputs found

    Evolving database systems : a persistent view

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    Submitted to POS7 This work was supported in St Andrews by EPSRC Grant GR/J67611 "Delivering the Benefits of Persistence"Orthogonal persistence ensures that information will exist for as long as it is useful, for which it must have the ability to evolve with the growing needs of the application systems that use it. This may involve evolution of the data, meta-data, programs and applications, as well as the users' perception of what the information models. The need for evolution has been well recognised in the traditional (data processing) database community and the cost of failing to evolve can be gauged by the resources being invested in interfacing with legacy systems. Zdonik has identified new classes of application, such as scientific, financial and hypermedia, that require new approaches to evolution. These applications are characterised by their need to store large amounts of data whose structure must evolve as it is discovered by the applications that use it. This requires that the data be mapped dynamically to an evolving schema. Here, we discuss the problems of evolution in these new classes of application within an orthogonally persistent environment and outline some approaches to these problems.Postprin

    Learning Visual Importance for Graphic Designs and Data Visualizations

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    Knowing where people look and click on visual designs can provide clues about how the designs are perceived, and where the most important or relevant content lies. The most important content of a visual design can be used for effective summarization or to facilitate retrieval from a database. We present automated models that predict the relative importance of different elements in data visualizations and graphic designs. Our models are neural networks trained on human clicks and importance annotations on hundreds of designs. We collected a new dataset of crowdsourced importance, and analyzed the predictions of our models with respect to ground truth importance and human eye movements. We demonstrate how such predictions of importance can be used for automatic design retargeting and thumbnailing. User studies with hundreds of MTurk participants validate that, with limited post-processing, our importance-driven applications are on par with, or outperform, current state-of-the-art methods, including natural image saliency. We also provide a demonstration of how our importance predictions can be built into interactive design tools to offer immediate feedback during the design process

    Linking Text and Image with SVG

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    Annotation and linking (or referring) have been described as "scholarly primitives", basic methods used in scholarly research and publication of all kinds. The online publication of manuscript images is one basic use case where the need for linking and annotation is very clear. High resolution images are of great use to scholars and transcriptions of texts provide for search and browsing, so the ideal method for the digital publication of manuscript works is the presentation of page images plus a transcription of the text therein. This has become a standard method, but leaves open the questions of how deeply the linkages can be done and how best to handle the annotation of sections of the image. This paper presents a new method (named img2xml) for connecting text and image using an XML-based tracing of the text on the page image. The tracing method was developed as part of a series of experiments in text and image linking beginning in the summer of 2008 and will continue under a grant funded by the National Endowment for the Humanities. It employs Scalable Vector Graphics (SVG) to represent the text in an image of a manuscript page in a referenceable form and enables linking and annotation of the page image in a variety of ways. The paper goes on to discuss the scholarly requirements for tools that will be developed around the tracing method, and explores some of the issues raised by the img2xml method

    Computer Vision and Image Processing: A Paper Review

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    Computer vision has been studied from many persective. It expands from raw data recording into techniques and ideas combining digital image processing, pattern recognition, machine learning and computer graphics. The wide usage has attracted many scholars to integrate with many disciplines and fields. This paper provide a survey of the recent technologies and theoretical concept explaining the development of computer vision especially related to image processing using different areas of their field application. Computer vision helps scholars to analyze images and video to obtain necessary information,    understand information on events or descriptions, and scenic pattern. It used method of multi-range application domain with massive data analysis. This paper provides contribution of recent development on reviews related to computer vision, image processing, and their related studies. We categorized the computer vision mainstream into four group e.g., image processing, object recognition, and machine learning. We also provide brief explanation on the up-to-date information about the techniques and their performance

    Exploiting frame coherence in real-time rendering for energy-efficient GPUs

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    The computation capabilities of mobile GPUs have greatly evolved in the last generations, allowing real-time rendering of realistic scenes. However, the desire for processing complex environments clashes with the battery-operated nature of smartphones, for which users expect long operating times per charge and a low-enough temperature to comfortably hold them. Consequently, improving the energy-efficiency of mobile GPUs is paramount to fulfill both performance and low-power goals. The work of the processors from within the GPU and their accesses to off-chip memory are the main sources of energy consumption in graphics workloads. Yet most of this energy is spent in redundant computations, as the frame rate required to produce animations results in a sequence of extremely similar images. The goal of this thesis is to improve the energy-efficiency of mobile GPUs by designing micro-architectural mechanisms that leverage frame coherence in order to reduce the redundant computations and memory accesses inherent in graphics applications. First, we focus on reducing redundant color computations. Mobile GPUs typically employ an architecture called Tile-Based Rendering, in which the screen is divided into tiles that are independently rendered in on-chip buffers. It is common that more than 80% of the tiles produce exactly the same output between consecutive frames. We propose Rendering Elimination (RE), a mechanism that accurately determines such occurrences by computing and storing signatures of the inputs of all the tiles in a frame. If the signatures of a tile across consecutive frames are the same, the colors computed in the preceding frame are reused, saving all computations and memory accesses associated to the rendering of the tile. We show that RE vastly outperforms related schemes found in the literature, achieving a reduction of energy consumption of 37% and execution time of 33% with minimal overheads. Next, we focus on reducing redundant computations of fragments that will eventually not be visible. In real-time rendering, objects are processed in the order they are submitted to the GPU, which usually causes that the results of previously-computed objects are overwritten by new objects that turn occlude them. Consequently, whether or not a particular object will be occluded is not known until the entire scene has been processed. Based on the fact that visibility tends to remain constant across consecutive frames, we propose Early Visibility Resolution (EVR), a mechanism that predicts visibility based on information obtained in the preceding frame. EVR first computes and stores the depth of the farthest visible point after rendering each tile. Whenever a tile is rendered in the following frame, primitives that are farther from the observer than the stored depth are predicted to be occluded, and processed after the ones predicted to be visible. Additionally, this visibility prediction scheme is used to improve Rendering Elimination’s equal tile detection capabilities by not adding primitives predicted to be occluded in the signature. With minor hardware costs, EVR is shown to provide a reduction of energy consumption of 43% and execution time of 39%. Finally, we focus on reducing computations in tiles with low spatial frequencies. GPUs produce pixel colors by sampling triangles once per pixel and performing computations on each sampling location. However, most screen regions do not include sufficient detail to require high sampling rates, leading to a significant amount of energy wasted computing the same color for neighboring pixels. Given that spatial frequencies are maintained across frames, we propose Dynamic Sampling Rate, a mechanism that analyzes the spatial frequencies of tiles and determines the best sampling rate for them, which is applied in the following frame. Results show that Dynamic Sampling Rate significantly reduces processor activity, yielding energy savings of 40% and execution time reductions of 35%.La capacitat de càlcul de les GPU mòbils ha augmentat en gran mesura en les darreres generacions, permetent el renderitzat de paisatges complexos en temps real. Nogensmenys, el desig de processar escenes cada vegada més realistes xoca amb el fet que aquests dispositius funcionen amb bateries, i els usuaris n’esperen llargues durades i una temperatura prou baixa com per a ser agafats còmodament. En conseqüència, millorar l’eficiència energètica de les GPU mòbils és essencial per a aconseguir els objectius de rendiment i baix consum. Els processadors de la GPU i els seus accessos a memòria són els principals consumidors d’energia en càrregues gràfiques, però molt d’aquest consum és malbaratat en càlculs redundants, ja que les animacions produïdes s¿aconsegueixen renderitzant una seqüència d’imatges molt similars. L’objectiu d’aquesta tesi és millorar l’eficiència energètica de les GPU mòbils mitjançant el disseny de mecanismes microarquitectònics que aprofitin la coherència entre imatges per a reduir els càlculs i accessos redundants inherents a les aplicacions gràfiques. Primerament, ens centrem en reduir càlculs redundants de colors. A les GPU mòbils, sovint s'empra una arquitectura anomenada Tile-Based Rendering, en què la pantalla es divideix en regions que es processen independentment dins del xip. És habitual que més del 80% de les regions de pantalla produeixin els mateixos colors entre imatges consecutives. Proposem Rendering Elimination (RE), un mecanisme que determina acuradament aquests casos computant una signatura de les entrades de totes les regions. Si les signatures de dues imatges són iguals, es reutilitzen els colors calculats a la imatge anterior, el que estalvia tots els càlculs i accessos a memòria de la regió. RE supera àmpliament propostes relacionades de la literatura, aconseguint una reducció del consum energètic del 37% i del temps d’execució del 33%. Seguidament, ens centrem en reduir càlculs redundants en fragments que eventualment no seran visibles. En aplicacions gràfiques, els objectes es processen en l’ordre en què son enviats a la GPU, el que sovint causa que resultats ja processats siguin sobreescrits per nous objectes que els oclouen. Per tant, no se sap si un objecte serà visible o no fins que tota l’escena ha estat processada. Fonamentats en el fet que la visibilitat tendeix a ser constant entre imatges, proposem Early Visibility Resolution (EVR), un mecanisme que prediu la visibilitat basat en informació obtinguda a la imatge anterior. EVR computa i emmagatzema la profunditat del punt visible més llunyà després de processar cada regió de pantalla. Quan es processa una regió a la imatge següent, es prediu que les primitives més llunyanes a el punt guardat seran ocloses i es processen després de les que es prediuen que seran visibles. Addicionalment, aquest esquema de predicció s’empra en millorar la detecció de regions redundants de RE al no afegir les primitives que es prediu que seran ocloses a les signatures. Amb un cost de maquinari mínim, EVR aconsegueix una millora del consum energètic del 43% i del temps d’execució del 39%. Finalment, ens centrem a reduir càlculs en regions de pantalla amb poca freqüència espacial. Les GPU actuals produeixen colors mostrejant els triangles una vegada per cada píxel i fent càlculs a cada localització mostrejada. Però la majoria de regions no tenen suficient detall per a necessitar altes freqüències de mostreig, el que implica un malbaratament d’energia en el càlcul del mateix color en píxels adjacents. Com les freqüències tendeixen a mantenir-se en el temps, proposem Dynamic Sampling Rate (DSR)¸ un mecanisme que analitza les freqüències de les regions una vegada han estat renderitzades i en determina la menor freqüència de mostreig a la que es poden processar, que s’aplica a la següent imatge..

    Exploiting frame coherence in real-time rendering for energy-efficient GPUs

    Get PDF
    The computation capabilities of mobile GPUs have greatly evolved in the last generations, allowing real-time rendering of realistic scenes. However, the desire for processing complex environments clashes with the battery-operated nature of smartphones, for which users expect long operating times per charge and a low-enough temperature to comfortably hold them. Consequently, improving the energy-efficiency of mobile GPUs is paramount to fulfill both performance and low-power goals. The work of the processors from within the GPU and their accesses to off-chip memory are the main sources of energy consumption in graphics workloads. Yet most of this energy is spent in redundant computations, as the frame rate required to produce animations results in a sequence of extremely similar images. The goal of this thesis is to improve the energy-efficiency of mobile GPUs by designing micro-architectural mechanisms that leverage frame coherence in order to reduce the redundant computations and memory accesses inherent in graphics applications. First, we focus on reducing redundant color computations. Mobile GPUs typically employ an architecture called Tile-Based Rendering, in which the screen is divided into tiles that are independently rendered in on-chip buffers. It is common that more than 80% of the tiles produce exactly the same output between consecutive frames. We propose Rendering Elimination (RE), a mechanism that accurately determines such occurrences by computing and storing signatures of the inputs of all the tiles in a frame. If the signatures of a tile across consecutive frames are the same, the colors computed in the preceding frame are reused, saving all computations and memory accesses associated to the rendering of the tile. We show that RE vastly outperforms related schemes found in the literature, achieving a reduction of energy consumption of 37% and execution time of 33% with minimal overheads. Next, we focus on reducing redundant computations of fragments that will eventually not be visible. In real-time rendering, objects are processed in the order they are submitted to the GPU, which usually causes that the results of previously-computed objects are overwritten by new objects that turn occlude them. Consequently, whether or not a particular object will be occluded is not known until the entire scene has been processed. Based on the fact that visibility tends to remain constant across consecutive frames, we propose Early Visibility Resolution (EVR), a mechanism that predicts visibility based on information obtained in the preceding frame. EVR first computes and stores the depth of the farthest visible point after rendering each tile. Whenever a tile is rendered in the following frame, primitives that are farther from the observer than the stored depth are predicted to be occluded, and processed after the ones predicted to be visible. Additionally, this visibility prediction scheme is used to improve Rendering Elimination’s equal tile detection capabilities by not adding primitives predicted to be occluded in the signature. With minor hardware costs, EVR is shown to provide a reduction of energy consumption of 43% and execution time of 39%. Finally, we focus on reducing computations in tiles with low spatial frequencies. GPUs produce pixel colors by sampling triangles once per pixel and performing computations on each sampling location. However, most screen regions do not include sufficient detail to require high sampling rates, leading to a significant amount of energy wasted computing the same color for neighboring pixels. Given that spatial frequencies are maintained across frames, we propose Dynamic Sampling Rate, a mechanism that analyzes the spatial frequencies of tiles and determines the best sampling rate for them, which is applied in the following frame. Results show that Dynamic Sampling Rate significantly reduces processor activity, yielding energy savings of 40% and execution time reductions of 35%.La capacitat de càlcul de les GPU mòbils ha augmentat en gran mesura en les darreres generacions, permetent el renderitzat de paisatges complexos en temps real. Nogensmenys, el desig de processar escenes cada vegada més realistes xoca amb el fet que aquests dispositius funcionen amb bateries, i els usuaris n’esperen llargues durades i una temperatura prou baixa com per a ser agafats còmodament. En conseqüència, millorar l’eficiència energètica de les GPU mòbils és essencial per a aconseguir els objectius de rendiment i baix consum. Els processadors de la GPU i els seus accessos a memòria són els principals consumidors d’energia en càrregues gràfiques, però molt d’aquest consum és malbaratat en càlculs redundants, ja que les animacions produïdes s¿aconsegueixen renderitzant una seqüència d’imatges molt similars. L’objectiu d’aquesta tesi és millorar l’eficiència energètica de les GPU mòbils mitjançant el disseny de mecanismes microarquitectònics que aprofitin la coherència entre imatges per a reduir els càlculs i accessos redundants inherents a les aplicacions gràfiques. Primerament, ens centrem en reduir càlculs redundants de colors. A les GPU mòbils, sovint s'empra una arquitectura anomenada Tile-Based Rendering, en què la pantalla es divideix en regions que es processen independentment dins del xip. És habitual que més del 80% de les regions de pantalla produeixin els mateixos colors entre imatges consecutives. Proposem Rendering Elimination (RE), un mecanisme que determina acuradament aquests casos computant una signatura de les entrades de totes les regions. Si les signatures de dues imatges són iguals, es reutilitzen els colors calculats a la imatge anterior, el que estalvia tots els càlculs i accessos a memòria de la regió. RE supera àmpliament propostes relacionades de la literatura, aconseguint una reducció del consum energètic del 37% i del temps d’execució del 33%. Seguidament, ens centrem en reduir càlculs redundants en fragments que eventualment no seran visibles. En aplicacions gràfiques, els objectes es processen en l’ordre en què son enviats a la GPU, el que sovint causa que resultats ja processats siguin sobreescrits per nous objectes que els oclouen. Per tant, no se sap si un objecte serà visible o no fins que tota l’escena ha estat processada. Fonamentats en el fet que la visibilitat tendeix a ser constant entre imatges, proposem Early Visibility Resolution (EVR), un mecanisme que prediu la visibilitat basat en informació obtinguda a la imatge anterior. EVR computa i emmagatzema la profunditat del punt visible més llunyà després de processar cada regió de pantalla. Quan es processa una regió a la imatge següent, es prediu que les primitives més llunyanes a el punt guardat seran ocloses i es processen després de les que es prediuen que seran visibles. Addicionalment, aquest esquema de predicció s’empra en millorar la detecció de regions redundants de RE al no afegir les primitives que es prediu que seran ocloses a les signatures. Amb un cost de maquinari mínim, EVR aconsegueix una millora del consum energètic del 43% i del temps d’execució del 39%. Finalment, ens centrem a reduir càlculs en regions de pantalla amb poca freqüència espacial. Les GPU actuals produeixen colors mostrejant els triangles una vegada per cada píxel i fent càlculs a cada localització mostrejada. Però la majoria de regions no tenen suficient detall per a necessitar altes freqüències de mostreig, el que implica un malbaratament d’energia en el càlcul del mateix color en píxels adjacents. Com les freqüències tendeixen a mantenir-se en el temps, proposem Dynamic Sampling Rate (DSR)¸ un mecanisme que analitza les freqüències de les regions una vegada han estat renderitzades i en determina la menor freqüència de mostreig a la que es poden processar, que s’aplica a la següent imatge...Postprint (published version

    Development of multiple media documents

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    Development of documents in multiple media involves activities in three different fields, the technical, the discoursive and the procedural. The major development problems of artifact complexity, cognitive processes, design basis and working context are located where these fields overlap. Pending the emergence of a unified approach to design, any method must allow for development at the three levels of discourse structure, media disposition and composition, and presentation. Related work concerned with generalised discourse structures, structured documents, production methods for existing multiple media artifacts, and hypertext design offer some partial forms of assistance at different levels. Desirable characteristics of a multimedia design method will include three phases of production, a variety of possible actions with media elements, an underlying discoursive structure, and explicit comparates for review

    Methodology and process to accompany a virtual geotechnical database for the St. Louis metropolitan area

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    The St. Louis metropolitan (STL) area, which spans Missouri and Illinois, currently has no overarching organization of geospatial data (geodata). The two states have their own geodata, using their own individual standards. The development of a virtual geotechnical database (VGDB) encompassing the entire STL area on both sides of the Mississippi River is a solution to the data sharing and standardization problem of this area. The VGDB integrates geodata from disparate sources into a geographic information systems (GIS) database accessible via the internet. The creation of the STL area VGDB consisted of three parts: 1) compiling the geodata; 2) formatting the geodata in GIS and extensible markup language (XML); 3) making the VGDB viewable in an internet browser --Abstract, page iii
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