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Feature-based Software Asset Modeling With Domain Specific KitsAltintas, Nesip Ilker 01 August 2007 (has links) (PDF)
This study proposes an industrialization model, Software Factory Automation, for establishing software product lines. Major contributions of this thesis are the conceptualization of Domain Specific Kits (DSKs) and a domain design model for software product lines based on DSKs. The concept of DSK has been inspired by the way other industries have been successfully realizing factory automation for decades. DSKs, as fundamental building blocks, have been deeply elaborated with their characteristic properties and with several examples.
The constructed domain design model has two major activities: first, building the product line reference architecture using DSK abstraction / and second, constructing reusable asset model again based on DSK concept. Both activities depend on outputs of feature-oriented analysis of product line domain. The outcome of these coupled modeling activities is the reference architecture and asset model of the product line.
The approach has been validated by constructing software product lines for two product families. The reusability of DSKs and software assets has also been discussed with examples. Finally, the constructed model has been evaluated in terms of quality improvements, and it has been compared with other software product line engineering approaches.
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Development Of A Step Feature-based Intelligent Process Planning System For Prismatic PartsAmaitik, Saleh Mohammed 01 June 2005 (has links) (PDF)
Computer aided process planning (CAPP) is generally acknowledged as a significant activity to achieve Computer Integrated Manufacturing (CIM). In coping with the dynamic changes in the modern manufacturing environment, the awareness of developing integrated and intelligent CAPP systems has been raised in an attempt to generate more successful implementation of intelligent manufacturing systems.
The main objective of this research work has been to develop an integrated intelligent process planning system that helps designers and process planners to improve their design and planning in the early stages of the product life cycle. In
order to achieve this goal, the following specific objectives have been accomplished:
(1) Developed a STEP-based feature modeler for building mechanical parts using high-level 3D solid features as the basic design entities. The modeler is capable of generating high-level product data in XML format according to
ISO 10303-AP224 standard. This file can be used to integrate into CAPP/CAM systems without using a complex feature recognition process.
(2) Developed a STEP-based intelligent process planning system for prismatic parts. The system maps STEP AP224 XML data file and produces the corresponding machining operations to generate a digital process plan in XML format according to ISO 14649 (STEP-NC) standard. A Hybrid
approach of most recent techniques of artificial intelligence (neural networks, fuzzy logic and rule-based) is used as the inference engine of the developed system.
Three neural network models are implemented to select machining operations, cutting tools, and machine tools. Several fuzzy logic models are utilized to select machining parameters for different machining operations, work material, and tool material combinations. The rule-based functions are utilized to perform operation sequence and setup planning.
An object-oriented approach has been used in the definition and implementation of the developed system. This approach offers advantages of incremental system development and reusability. The developed system is integrated
with AutoCAD using Activex automation interface. Several examples have been presented to demonstrate and verify the applicability of the developed system.
Finally, this research will contribute significantly to the applicability of advanced artificial intelligent techniques in CAPP systems. The implementation of STEP technology in this research will support the integration of CAPP system with
other systems in CIM environment. The developed system is intended to be an effective concurrent engineering tool that bridges the gap between design and manufacturing.
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A Feature Based Design Software For Parts To Be Machined In A Four-axis Cnc LatheHatipoglu, Demiralp 01 September 2005 (has links) (PDF)
A previously developed feature library and algorithm are improved in order to develop a software capable of designing of parts to be manufactured using a four-axis CNC lathe. The developed program is composed of sections which are / part geometry design, process planning, cutting tool and machining parameter selection, part program generation and G-code simulation for verification.
The developed program is capable of designing parts which contain axisymetric features for turning and related operations, and non-axisymetric features for milling on facial, lateral and cylindrical surfaces. Implemented design procedure defines a blank material shape that can be circular or polygonal cross-sectioned bar or a pre-manufactured part.
A detailed database is created for proper cutting tool selection and machining data determination. User can either define or let the program to automatically select the cutting parameters like cutting speed, feed rate and depth of cut for each cutting tool with respect to the workpiece material being machined. After completing design and process planning procedures / information for generation of the CNC program becomes readily available for editing or transferring to the CNC machine tool. User can also simulate the NC program to verify the tool path.
User friendly interface, which runs on Autodesk' / s INVENTOR software to visualize the design process, allows design and modifications to be done very easily moreover previously designed parts can be redesigned to produce new modified parts.
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Rigid and Non-rigid Point-based Medical Image RegistrationParra, Nestor Andres 13 November 2009 (has links)
The primary goal of this dissertation is to develop point-based rigid and non-rigid image registration methods that have better accuracy than existing methods. We first present point-based PoIRe, which provides the framework for point-based global rigid registrations. It allows a choice of different search strategies including (a) branch-and-bound, (b) probabilistic hill-climbing, and (c) a novel hybrid method that takes advantage of the best characteristics of the other two methods. We use a robust similarity measure that is insensitive to noise, which is often introduced during feature extraction. We show the robustness of PoIRe using it to register images obtained with an electronic portal imaging device (EPID), which have large amounts of scatter and low contrast. To evaluate PoIRe we used (a) simulated images and (b) images with fiducial markers; PoIRe was extensively tested with 2D EPID images and images generated by 3D Computer Tomography (CT) and Magnetic Resonance (MR) images. PoIRe was also evaluated using benchmark data sets from the blind retrospective evaluation project (RIRE). We show that PoIRe is better than existing methods such as Iterative Closest Point (ICP) and methods based on mutual information. We also present a novel point-based local non-rigid shape registration algorithm. We extend the robust similarity measure used in PoIRe to non-rigid registrations adapting it to a free form deformation (FFD) model and making it robust to local minima, which is a drawback common to existing non-rigid point-based methods. For non-rigid registrations we show that it performs better than existing methods and that is less sensitive to starting conditions. We test our non-rigid registration method using available benchmark data sets for shape registration. Finally, we also explore the extraction of features invariant to changes in perspective and illumination, and explore how they can help improve the accuracy of multi-modal registration. For multimodal registration of EPID-DRR images we present a method based on a local descriptor defined by a vector of complex responses to a circular Gabor filter.
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Vibration-Based Structural Health Monitoring of Structures Using a New Algorithm for Signal Feature Extraction and Investigation of Vortex-Induced VibrationsQarib, Hossein January 2020 (has links)
No description available.
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Alternative Approaches for the Registration of Terrestrial Laser Scanners Data using Linear/Planar FeaturesDewen Shi (9731966) 15 December 2020 (has links)
<p>Static terrestrial laser scanners have been increasingly used in three-dimensional data acquisition since it can rapidly provide accurate measurements with high resolution. Several scans from multiple viewpoints are necessary to achieve complete coverage of the surveyed objects due to occlusion and large object size. Therefore, in order to reconstruct three-dimensional models of the objects, the task of registration is required to transform several individual scans into a common reference frame. This thesis introduces three alternative approaches for the coarse registration of two adjacent scans, namely, feature-based approach, pseudo-conjugate point-based method, and closed-form solution. In the feature-based approach, linear and planar features in the overlapping area of adjacent scans are selected as registration primitives. The pseudo-conjugate point-based method utilizes non-corresponding points along common linear and planar features to estimate transformation parameters. The pseudo-conjugate point-based method is simpler than the feature-based approach since the partial derivatives are easier to compute. In the closed-form solution, a rotation matrix is first estimated by using a unit quaternion, which is a concise description of the rotation. Afterward, the translation parameters are estimated with non-corresponding points along the linear or planar features by using the pseudo-conjugate point-based method. Alternative approaches for fitting a line or plane to data with errors in three-dimensional space are investigated.</p><p><br></p><p>Experiments are conducted using simulated and real datasets to verify the effectiveness of the introduced registration procedures and feature fitting approaches. The proposed two approaches of line fitting are tested with simulated datasets. The results suggest that these two approaches can produce identical line parameters and variance-covariance matrix. The three registration approaches are tested with both simulated and real datasets. In the simulated datasets, all three registration approaches produced equivalent transformation parameters using linear or planar features. The comparison between the simulated linear and planar features shows that both features can produce equivalent registration results. In the real datasets, the three registration approaches using the linear or planar features also produced equivalent results. In addition, the results using real data indicates that the registration approaches using planar features produced better results than the approaches using linear features. The experiments show that the pseudo-conjugate point-based approach is easier to implement than the feature-based approach. The pseudo-conjugate point-based method and feature-based approach are nonlinear, so an initial guess of transformation parameters is required in these two approaches. Compared to the nonlinear approaches, the closed-form solution is linear and hence it can achieve the registration of two adjacent scans without the requirement of any initial guess for transformation parameters. Therefore, the pseudo-conjugate point-based method and closed-form solution are the preferred approaches for coarse registration using linear or planar features. In real practice, the planar features would have a better preference when compared to linear features since the linear features are derived indirectly by the intersection of neighboring planar features. To get enough lines with different orientations, planes that are far apart from each other have to be extrapolated to derive lines.</p><div><br></div>
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L'attention sélective et les traits visuels dans la correspondance transsaccadique / The role of visual attention and features in the transsaccadic correspondenceEymond, Cécile 30 November 2016 (has links)
Chaque saccade oculaire décale brusquement l'image projetée sur la rétine. Pourtant notre perception du monde reste stable et uniforme car le système visuel fait correspondre les informations avant et après chaque saccade. Pour établir cette correspondance, les mécanismes attentionnels seraient fondamentaux. Jusqu'à présent, ce lien transsaccadique a été mis en évidence par des études portant essentiellement sur le traitement des informations spatiales - à savoir, comment la position rétinienne d'un objet est corrigée à chaque saccade pour maintenir une perception stable du monde. Le traitement des traits visuels tels que la couleur ou la forme est encore mal compris et leur rôle dans l'impression de stabilité reste à établir. Est-ce que les traits et l'attention dédiée aux traits (feature-based attention), par définition indépendants de l'espace, participent aussi à la correspondance transsaccadique ? Pour analyser la relation entre le traitement des traits et celui des positions lors des saccades oculaires, cette thèse a suivi deux approches. La première s'est intéressée à la perception des attributs visuels, uniforme malgré l'hétérogénéité du système visuel. Les résultats ont montré que si la perception uniforme des attributs visuels s'appuie sur un apprentissage, les mécanismes sous-jacents ne seraient pas spécifiques aux mouvements oculaires. L'uniformité de la perception s'appuierait plutôt sur un mécanisme d'apprentissage associatif général. La seconde approche a cherché à mieux comprendre la nature de l'attention sélective transsaccadique. Les résultats ont montré que l'attention allouée à la cible d'une saccade ne contribue pas à aux mécanismes sélectifs guidés par les traits et engagés juste après l'exécution d'un mouvement oculaire. L'attention allouée à une cible saccadique et l'attention aux traits seraient alors indépendantes. Enfin, la dernière étude a montré que, lorsque l'attention sélective basée sur les traits est engagée pendant la préparation de la saccade en dehors de la cible saccadique, les traits sont maintenus pendant la saccade et affectent les processus sélectifs engagés juste après la saccade. L'attention transsaccadique ne serait alors pas de nature purement spatiale. L'ensemble de ces résultats suggère que les traits et l'attention aux traits joueraient un rôle dans la correspondance transsaccadique. / With each saccade, the image on the retina shifts abruptly but our perception of the surrounding world remains stable and uniform, because the visual system matches pre- and post-saccadic visual information. Attentional mechanisms could play a fundamental role in this process and numerous studies have examined the role of spatial attention. The processing of feature-based attention across saccades remains unclear and its role in matching pre- to post-saccadic visual information is not known. Do visual features and feature-based attention, assumed to enhance the feature-specific representations throughout the visual field, take part in the transsaccadic correspondence? To examine the relationship between feature and spatial processing, this thesis chose two approaches. The first one considered the uniform perception that we have for features despite the heterogeneity of the retina. Results show that, if the transsaccadic correspondence of visual features relies on learning, the underlying mechanisms would not be specific to eye movements. Visual constancy is more likely to arise from a general associative learning. The second approach examined the nature of transsaccadique attention. Results show that attention drawn to the saccade target did not contribute to selective mechanisms engaged just after an eye movement, suggesting a dissociation between feature-based attention and saccade programming. Finally, the last study show that feature-based selectivity is maintained across saccades to ensure spatiotopic correspondence, pointing out the potential role of feature-based attention in matching pre- to post-saccadic information.
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Mixed Signal Detection, Estimation, and Modulation ClassificationQu, Yang 18 December 2019 (has links)
No description available.
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Feature Based Image Mosaicing using Regions of Interest for Wide Area Surveillance Camera Arrays with Known Camera OrderingBallard, Brett S. 16 May 2011 (has links)
No description available.
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Discriminative Articulatory Feature-based Pronunciation Models with Application to Spoken Term DetectionPrabhavalkar, Rohit Prakash 27 September 2013 (has links)
No description available.
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