• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 17
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 28
  • 28
  • 8
  • 5
  • 5
  • 5
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The Constituents of Action Representation Evoked When Identifying Manipulable Objects

Lin, Yu-Tang Terry 08 May 2014 (has links)
We examined the effects of keeping hand actions in working memory on the speed of naming handled objects. The features of the hand action and objects’ handle matched or mismatched on two dimensions: alignment (left vs. right), orientation (horizontal vs. vertical). For objects presented in their canonical upright position, the speed of naming was only slower when the actions were partially incongruent with the target object. For rotated objects, the effect was reversed. The pattern of results suggests that the identification system is more sensitive to the functional goal (i.e. the end state) of the rotated object in evoking action representations than the actions evoked by the depicted view (i.e. the beginning state). The findings, overall, strongly support the notion that action representations play a functional role in object identification. / Graduate / 0633 / 0623 / tlin23@gmail.com
2

The Constituents of Action Representation Evoked When Identifying Manipulable Objects

Lin, Yu-Tang Terry 08 May 2014 (has links)
We examined the effects of keeping hand actions in working memory on the speed of naming handled objects. The features of the hand action and objects’ handle matched or mismatched on two dimensions: alignment (left vs. right), orientation (horizontal vs. vertical). For objects presented in their canonical upright position, the speed of naming was only slower when the actions were partially incongruent with the target object. For rotated objects, the effect was reversed. The pattern of results suggests that the identification system is more sensitive to the functional goal (i.e. the end state) of the rotated object in evoking action representations than the actions evoked by the depicted view (i.e. the beginning state). The findings, overall, strongly support the notion that action representations play a functional role in object identification. / Graduate / 0633 / 0623 / tlin23@gmail.com
3

Form Follows Function: The Time Course of Action Representations Evoked by Handled Objects

Kumar, Ragav 21 August 2015 (has links)
To investigate the role of action representations in the identification of upright and rotated objects, we examined the time course of their evocation. Across five experiments, subjects made vertically or horizontally oriented reach and grasp actions primed by images of handled objects that were depicted in upright or rotated orientations, at various Stimulus Onset Asynchronies: -250 ms (action cue preceded the prime), 0 ms, and +250 ms. Congruency effects between action and object orientation were driven by the object's canonical (upright) orientation at the 0 ms SOA, but by its depicted orientation at the +250 ms SOA. Alignment effects between response hand and the object's handle appeared only at the +250 ms SOA, and were driven by the depicted orientation. Surprisingly, an attempt to replicate this finding with improved stimuli (Experiment 3) did not show significant congruency effects at the 0 ms SOA; a further examination of the 0 ms SOA in Experiments 4 and 5 also failed to reach significance. However, a meta-analysis of the latter three experiments showed evidence for the congruency effect, suggesting that the experiments might just have been underpowered. We conclude that subjects initially evoke a conceptually-driven motor representation of the object, and that only after some time can the depicted form become prominent enough to influence the elicited action representation. / Graduate / 0633 / ragavk@uvic.ca
4

Νέες κατευθύνσεις στην αυτόματη ταυτοποίηση αντικειμένων : επιχειρηματικές προκλήσεις

Παπαδάτος, Παναγιώτης 19 January 2011 (has links)
Τα τελευταία χρόνια, η τεχνολογία ραδιοσυχνικής αναγνώρισης (Radio Frequency Identification), πιο γνωστή ως RFID, γνωρίζει σημαντική ανάπτυξη και υιοθετείται σε πολλές εφαρμογές παγκοσμίως. Πρόκειται για μια τεχνολογία, αυτόματης αναγνώρισης αντικειμένων ή/και προσώπων που φέρουν RFID ετικέτα, η οποία συγκεντρώνει σημαντικά χαρακτηριστικά που μπορούν να αξιοποιηθούν για την υποστήριξη υποδομών και συστημάτων ελέγχου προσπέλασης και αναγνώρισης. Τα συστήματα RFID γίνονται ολοένα και περισσότερο δημοφιλή στην εφαρμογή τους σε ολοκληρωμένα επιχειρησιακά συστήματα όπως διαχείρισης εφοδιαστικής αλυσίδας, αναγνώρισης αντικειμένων, ιχνηλάτισης, διαχείρισης εγγράφων αλλά και σε γενικότερο επίπεδο σε εφαρμογές που απαιτούν αναγνώριση των αντικειμένων / ανθρώπων. Ταυτόχρονα με την ανάπτυξη του προτύπου Electronic Product Code‐EPC καθίσταται πλέον δυνατή η αυτόματη αναγνώριση της ταυτότητας των προϊόντων, επιφέροντας μία επαναστατική αλλαγή στον τρόπο που οι επιχειρήσεις διαχειρίζονται και επιβλέπουν τη ροή των υλικών και των πληροφοριών από την παραγωγή του προϊόντος μέχρι την τελική εναπόθεσή του στο ράφι του καταστήματος λιανικής πώλησης. Στο παρόν σύγγραμμα παρέχονται όλες οι απαραίτητες πληροφορίες για την κατανόηση των βασικών χαρακτηριστικών λειτουργίας της μεθόδου RFID καθώς και των προοπτικών εφαρμογής της σε διάφορες επιχειρηματικές εφαρμογές. Η συγκεκριμένη εργασία σαν κύριο στόχο έχει την λεπτομερή περιγραφή της νέας αυτής τεχνολογίας σε επίπεδο συστημικό και εφαρμογών, εστιάζοντας ταυτόχρονα σε τρία κύρια σημεία: κόστος, ιδιωτικότητα, ασφάλεια. Ταυτόχρονα θα γίνει έρευνα που θα αποκαλύπτει την διείσδυση – adoption της καινοτόμας αυτής τεχνολογίας σε Εθνικό και Ευρωπαϊκό επίπεδο παρουσιάζοντας τόσο τις επιχειρήσεις που δραστηριοποιούνται στον χώρο της ανάπτυξης συστημάτων RFID όσο και τις επιχειρήσεις οι οποίες έχουν υιοθετήσει αντίστοιχες λύσεις αυτοματοποίησης των επιχειρησιακών τους διαδικασιών. Επιπλέον θα καταγράψουμε την συμβολή του προτύπου Ηλεκτρονικού Κωδικού Προϊόντος (Electronic Product Code, EPC), που έχει αναπτυχθεί από τον EPCglobal και βοηθά στην αναγνώριση μεμονωμένων αντικειμένων. Πρότυπο στο οποίο βασίζεται το EPCglobal δίκτυο (EPCglobal Network) για αναγνώριση μέσω ραδιοσυχνοτήτων και διευκόλυνση της ορατότητας και διαμοιρασμό των πληροφοριών που σχετίζονται με αντικείμενα ή/και άτομα. Εκτενής αναφορά τέλος θα γίνει και για τις πολιτικές και τα επόμενα βήματα που έχει χαράξει η Ευρωπαϊκή Ένωση για τη χρήση της νέας τεχνολογίας RFID. / -
5

Understanding the dynamics of functional and volumetric action representations when prepared for immediate execution

Wang, Duo 02 January 2019 (has links)
This study examines the state of competing affordances when an action is prepared for immediate production. More specifically, we investigated the nature of motor representations evoked by distinct action intentions, with a special interest in functional (grasp to use) and volumetric (grasp to lift) actions. With just two objects available, participants were asked to prepare an action on a particular object (e.g., preparing to lift the cellphone), and when signaled, either to perform this original action plan or to switch to executing an alternative one, either on the same or different object. By manipulating cueing methods used for indicating the preparatory and the target action plans, we found distinct patterns in the effect of preserving either object (different action on the same object) or action (same grasp type on a different object) on action execution. Changing either component of the action-object pairing incurred a cost in response time. In Experiment 1, a cost was observed when a prepared action was switched to an alternate action on the same object. For example, preparing to lift a cellphone but switching instead to a use action on the same object, incurred a cost. A further cost was found when subjects prepared a functional action to one object (e.g., use the cellphone) but switched to the same class of action on the alternate object (e.g., use the spray can). Both these effects were found to operate at the motor level. No costs were observed when subjects switched from a planned action to naming the target object (Experiment 3). Crucially, it was found that the nature of the cueing method instructing subjects to switch from a planned to an alternate action impacted the effect of action congruency. The cost observed in Experiment 1 when subjects switched to an alternate action on the same object occurred when the switch from a planned to an alternate action was cued by a verb-noun combination (e.g., use cellphone). No such cost occurred when the action was cued by a verb (e.g., use) and the target object was spatially cued by an arrow pointing to its location (Experiment 2). The cost of switching from a planned action type (e.g., a use action) to the same action type carried on the alternate object also depended on whether the planned action was verbally or spatially cued. These results provide new evidence on the nature of action representations associated with different motor intentions, as well as of the nature of action-object pairings. / Graduate
6

Getting a Handle on Meaning: Planned Hand Actions' Influence on the Identification of Handled Objects

Moise, Noah 03 October 2022 (has links)
We confirm that under certain conditions, constituents of motor actions afforded by handled objects play a role in their identification. Subjects held in working memory action plans specifying both the laterality of the hand to be used (left or right) and a wrist orientation (vertical or horizontal). Speeded object identification was impaired when a pictured object matched the action on only one of these two categorical dimensions (e.g., a frying pan with its handle facing left, an action plan involving the right hand and horizontal wrist orientation), relative to when the object matched the action on both dimensions or neither dimension. This phenomenon only occurred for a semantic task (i.e., naming) and significantly weakened when the handled object was named following the naming of a non-handled object. These results imply that, when maintaining the features of planned actions in working memory, identification of the object leads to conflict between components of the action plan and features of the grasp action afforded by the depicted object. When bound to a matching feature, the discrepant features cannot be easily disregarded, and conflict with the features of the target object resulted in delayed identification. Naming a non-handled object first weakens the pragmatic processing generated by attending to the features of the action plans, resulting in less conflict when only one feature matched between the action plan and action afforded by the handled object. / Graduate
7

The leaf identification problem : natural scene statistics and human performance

Ing, Almon David 21 September 2010 (has links)
For animals with advanced nervous systems, survival and reproduction can depend upon accurate perception of the environment. To understand how a perceptual system should solve a perception task, it is important to consider designs for an ideal observer, a theoretical system that solves a perception task in an optimal way given specific constraints. I studied three specific classification tasks related to the problem of identifying and segmenting leaves in foliage-rich images. In order to derive the ideal observers for these tasks, I created a database of hand-segmented leaves which served to define the ground-truth for these tasks. I also created a new method that uses the ground-truth as a basis for performing statistical inference (classification) in a nearly optimal way. This made it possible for me to approximate ideal observers by approximating an optimal classifier for each task. I also conducted psychophysical experiments to measure human performance in these tasks. The results provide information about how the human visual system should and does interpret foliage-rich images. / text
8

Modeling object identification and tracking errors on automated spatial safety assessment of earthmoving operations

Chi, Seok Ho 01 October 2010 (has links)
Recent research studies have been conducted for automating the safety assessment process in order to identify risks and safety hazards on a job site without human intervention. Regardless of the benefits of automated assessment, safety planners still face challenges selecting applicable devices, methods, and algorithms for safety assessment. This is due to the fact that (1) such devices, methods, and algorithms typically have measurement and processing errors, (2) construction operations and sites are unique and complex, and (3) the impact of the errors is different depending on workspaces. The primary objective of this research is to develop an error impact analysis method to model data collection and data processing errors caused by image-based devices and algorithms and to analyze the impact of the errors for spatial safety assessment of earthmoving and surface mining activities. The literature review revealed the possible causes of accidents on earthmoving activities, investigated the spatial risk factors of these types of accident, and identified spatial data needs for safety assessment based on current safety regulations. Image-based data collection devices and algorithms for safety assessment were then evaluated. Analysis methods and rules for monitoring safety violations were also discussed. A testbed to model and simulate workspaces and related spatial safety violations was finally designed. Using the testbed, the impacts of image-based algorithm and device errors―more specifically, object identification and tracking errors―on the data collected and processed were investigated for the safety planning purpose. Field experiments assessed the feasibility of automated spatial data collection and analysis methods. Industrial project and safety experts verified the proposed safety rules and the testbed design. Computer simulations were conducted for testing the proposed testbed. The testbed was used to model several earthmoving operation scenarios, detect simulated safety violations using safety rules, and finally evaluate the impact of different object identification and tracking errors on the safety analyses. The result of this research could be used for improving site safety assessment and planning by assisting safety planners to understand workspaces and to evaluate errors related to the use of different image-based technologies for safety assessment of earthmoving and surface mining activities. / text
9

A wide spectrum type system for transformation theory

Ladkau, Matthias January 2009 (has links)
One of the most difficult tasks a programmer can be confronted with is the migration of a legacy system. Usually, these systems are unstructured, poorly documented and contain complex program logic. The reason for this, in most cases, is an emphasis on raw performance rather than on clean and structured code as well as a long period of applying quick fixes and enhancements rather than doing a proper software reengineering process including a full redesign during major enhancements. Nowadays, the old programming paradigms are becoming an increasingly serious problem. It has been identified that 90% of the costs of a typical software system arise in the maintenance phase. Many companies are simply too afraid of changing their software infrastructure and prefer to continue with principles like "never touch a running system". These companies experience growing pressure to migrate their legacy systems onto newer platforms because the maintenance of such systems is expensive and dangerous as the risk of losing vital parts of sources code or its documentation increases drastically over time. The FermaT transformation system has shown the ability to automatically or semi-automatically restructure and abstract legacy code within a special intermediate language called WSL (Wide Spectrum Language). Unfortunately, the current transformation process only supports the migration of assembler as WSL lacks the ability to handle data types properly. The data structures in assembler are currently directly translated into C data types which involves many assumptional “hard coded” conversions. The absence of an adequate type system for WSL caused several flaws for the whole transformation process and limits its abilities significantly. The main aim of the presented research is to tackle these problems by investigating and formulating how a type system can contribute to a safe and reliable migration of legacy systems. The described research includes the definition of key aspects of type related problems in the FermaT migration process and how to solve them with a suitable type system approach. Since software migration often includes a change in programming language the type system for WSL has to be able to support various type system approaches including the representation of all relevant details to avoid assumptions. This is especially difficult as most programming languages are designed for a special purpose which means that their possible programming constructs and data types differ significantly. This ranges from languages with simple type systems whose program sare prone to unintended side-effects, to languages with strict type systems which are constrained n their flexibility. It is important to include as many type related details as necessary to avoid making assumptions during language to language translation. The result of the investigation is a novel multi layered type system specifically designed to satisfy the needs of WSL for a sophisticated solution without imposing too many limitations on its abilities. The type system has an adjustable expressiveness, able to represent a wide spectrum of typing approaches ranging from weak typing which allows direct memory access and down casting, via very strict typing with a high diversity of data types to object oriented typing which supports encapsulation and data hiding. Looking at the majority of commercial relevant statically typed programming languages, two fundamental properties of type strictness and safety can be identified. A type system can be either weakly or strongly typed and may or may not allow unsafe features such as direct memory access. Each layer of the Wide Spectrum Type System has a different combination of these properties. The approach also includes special Type System Transformations which can be used to move a given WSL program among these layers. Other emphasised key features are explicit typing and scalability. The whole approach is based on a sound mathematical foundation which assures correctness and integrates seamlessly into the present mathematical definition of WSL. The type system is formally introduced to WSL by constructing an attribute grammar for the language. Type checking and type inference are used to annotate the Abstract Syntax Tree of a given WSL program with type derivations which can be used to reveal and indicate possible typing errors or to infer types if the program did not feature explicit type declarations in the first place. Notable in this approach is also the fact that object orientation is introduced to a procedural programming language without the introduction of new semantics. It is shown that object orientation can be introduced just by adjusting type checking rules and adding some syntactical notations. The approach was implemented and tested on two case studies. The thesis describes and discusses both cases in detail and shows how a migration which ignores type systems could accidentally introduce errors due to assumptions during translation. Both case studies use all important aspects of the approach, Including type transformations and object identification. The thesis finalises by summarising the whole work, identifying limitations, presenting future perspectives and drawing conclusions
10

Automated freeform assembly of threaded fasteners

Dharmaraj, Karthick January 2015 (has links)
Over the past two decades, a major part of the manufacturing and assembly market has been driven by its customer requirements. Increasing customer demand for personalised products create the demand for smaller batch sizes, shorter production times, lower costs, and the flexibility to produce families of products - or different parts - with the same sets of equipment. Consequently, manufacturing companies have deployed various automation systems and production strategies to improve their resource efficiency and move towards right-first-time production. However, many of these automated systems, which are involved with robot-based, repeatable assembly automation, require component- specific fixtures for accurate positioning and extensive robot programming, to achieve flexibility in their production. Threaded fastening operations are widely used in assembly. In high-volume production, the fastening processes are commonly automated using jigs, fixtures, and semi-automated tools. This form of automation delivers reliable assembly results at the expense of flexibility and requires component variability to be adequately controlled. On the other hand, in low- volume, high- value manufacturing, fastening processes are typically carried out manually by skilled workers. This research is aimed at addressing the aforementioned issues by developing a freeform automated threaded fastener assembly system that uses 3D visual guidance. The proof-of-concept system developed focuses on picking up fasteners from clutter, identifying a hole feature in an imprecisely positioned target component and carry out torque-controlled fastening. This approach has achieved flexibility and adaptability without the use of dedicated fixtures and robot programming. This research also investigates and evaluates different 3D imaging technology to identify the suitable technology required for fastener assembly in a non-structured industrial environment. The proposed solution utilises the commercially available technologies to enhance the precision and speed of identification of components for assembly processes, thereby improving and validating the possibility of reliably implementing this solution for industrial applications. As a part of this research, a number of novel algorithms are developed to robustly identify assembly components located in a random environment by enhancing the existing methods and technologies within the domain of the fastening processes. A bolt identification algorithm was developed to identify bolts located in a random clutter by enhancing the existing surface-based matching algorithm. A novel hole feature identification algorithm was developed to detect threaded holes and identify its size and location in 3D. The developed bolt and feature identification algorithms are robust and has sub-millimetre accuracy required to perform successful fastener assembly in industrial conditions. In addition, the processing time required for these identification algorithms - to identify and localise bolts and hole features - is less than a second, thereby increasing the speed of fastener assembly.

Page generated in 0.1308 seconds