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Showing papers on "Representation (systemics) published in 2011"


Book
06 Aug 2011
TL;DR: This chapter discusses the construction of curves for B-spline Surfaces using Bezier Curves and discusses the various approaches used to estimate these Curves.
Abstract: Chapter 1 - Curve and Surface Representation Chapter 2 - Bezier Curves Chapter 3 - B-spline Curves Chapter 4 - Rational B-spline Curves Chapter 5 - Bezier Surfaces Chapter 6 - B-spline Surfaces Chapter 7 - Rational B-spline Surfaces Appendices

743 citations


Journal Article
TL;DR: Methods for learning dictionaries that are appropriate for the representation of given classes of signals and multisensor data are described and dimensionality reduction based on dictionary representation can be extended to address specific tasks such as data analy sis or classification.
Abstract: We describe methods for learning dictionaries that are appropriate for the representation of given classes of signals and multisensor data. We further show that dimensionality reduction based on dictionary representation can be extended to address specific tasks such as data analy sis or classification when the learning includes a class separability criteria in the objective function. The benefits of dictionary learning clearly show that a proper understanding of causes underlying the sensed world is key to task-specific representation of relevant information in high-dimensional data sets.

705 citations


Journal ArticleDOI
TL;DR: It is found that abstract words are more emotionally valenced than are concrete words, and this accounts for a residual latency advantage for abstract words, when variables such as imageability and rated context availability are held constant.
Abstract: Although much is known about the representation and processing of concrete concepts, knowledge of what abstract semantics might be is severely limited. In this article we first address the adequacy of the 2 dominant accounts (dual coding theory and the context availability model) put forward in order to explain representation and processing differences between concrete and abstract words. We find that neither proposal can account for experimental findings and that this is, at least partly, because abstract words are considered to be unrelated to experiential information in both of these accounts. We then address a particular type of experiential information, emotional content, and demonstrate that it plays a crucial role in the processing and representation of abstract concepts: Statistically, abstract words are more emotionally valenced than are concrete words, and this accounts for a residual latency advantage for abstract words, when variables such as imageability (a construct derived from dual coding theory) and rated context availability are held constant. We conclude with a discussion of our novel hypothesis for embodied abstract semantics.

631 citations


Journal ArticleDOI
TL;DR: The LTS4 Reference EPFL-ARTICLE-161378 describes the design and construction of the EMMARM, and some of the components that went into the machine learning system were developed and tested in the lab.
Abstract: Keywords: LTS4 Reference EPFL-ARTICLE-161378 Record created on 2010-12-02, modified on 2017-05-10

559 citations


Journal ArticleDOI
TL;DR: A review and critical analysis of the mathematical literature concerning the modeling of vehicular traffic and crowd phenomena and a critical analysis focused on research perspectives that consider the development of a unified modeling strategy are presented.
Abstract: This paper presents a review and critical analysis of the mathematical literature concerning the modeling of vehicular traffic and crowd phenomena. The survey of models deals with the representation scales and the mathematical frameworks that are used for the modeling approach. The paper also considers the challenging objective of modeling complex systems consisting of large systems of individuals interacting in a nonlinear manner, where one of the modeling difficulties is the fact that these systems are difficult to model at a global level when based only on the description of the dynamics of individual elements. The review is concluded with a critical analysis focused on research perspectives that consider the development of a unified modeling strategy.

434 citations


Journal ArticleDOI
TL;DR: The Network-Free Stochastic Simulator (NFsim) is introduced, a general- Purpose modeling platform that overcomes the combinatorial nature of molecular interactions and enables researchers to simulate many biological systems that were previously inaccessible to general-purpose software.
Abstract: The Network-Free Stochastic Simulator (NFsim) allows the representation of complex biological systems as rule-based models and facilitates coarse-graining of the reaction mechanisms.

322 citations


Proceedings ArticleDOI
20 Jun 2011
TL;DR: This novel approach “imagines” an actor performing an action typical for the target object class, instead of relying purely on the visual object appearance, and handles function as a cue complementary to appearance, rather than being a consideration after appearance-based detection.
Abstract: Many object classes are primarily defined by their functions. However, this fact has been left largely unexploited by visual object categorization or detection systems. We propose a method to learn an affordance detector. It identifies locations in the 3d space which “support” the particular function. Our novel approach “imagines” an actor performing an action typical for the target object class, instead of relying purely on the visual object appearance. So, function is handled as a cue complementary to appearance, rather than being a consideration after appearance-based detection. Experimental results are given for the functional category “sitting”. Such affordance is tested on a 3d representation of the scene, as can be realistically obtained through SfM or depth cameras. In contrast to appearance-based object detectors, affordance detection requires only very few training examples and generalizes very well to other sittable objects like benches or sofas when trained on a few chairs.

283 citations


Journal ArticleDOI
TL;DR: In this paper, complete and transitive preferences that are convex and monotone were studied and a representation result was established, which is at the same time general and rich in structure.

252 citations


Journal ArticleDOI
TL;DR: This article argued that the traditional representational approach is too limiting as regards the epistemic value of modelling given the focus on the relationship between a single model and its supposed target system, and the neglect of the actual representational means with which scientists construct models.

233 citations


Journal ArticleDOI
TL;DR: This editorial of the special issue ''Representing, Processing, and Learning Preferences: Theoretical and Practical Challenges'' surveys past and ongoing research on preferences in AI, including references and pointers to the literature.

196 citations


Journal ArticleDOI
01 Jan 2011
TL;DR: Ramsey as mentioned in this paper argues that the notion of representation has the same explanatory value as knowledge, and that it cannot be used as a theoretical posit in certain branches of cognitive science, e.g., psychology and neuroscience.
Abstract: Some books are just begging to be written. This is one such. It gives a long overdue critical look at the nearly universal tendency to invoke the notion of ‘‘representation’’ as a theoretical posit in certain branches of the cognitive sciences, e.g., psychology and neuroscience. As the preface and opening chapter make clear, Ramsey’s project is to ask, from the vantage point of philosophy of science, whether positing representations has the sort of explanatory value it is generally imagined to have. His principal focus is to determine if the explanatory posits that are in fact employed by these sciences meet the minimal criteria for doing bona fide representational work. As he puts it, the question is whether or not such proposals meet the ‘‘job description challenge.’’ Adequately meeting that challenge requires saying not only what determines the content of a state or structure but also, critically, saying how that state or structure serves or functions as a representation in a larger system. Ramsey’s assessment is that when the notion of representation is invoked in an important class of cases this challenge cannot be met. However, he claims (chapter 3) that there are, at least, two prominent uses of the notion in the classical framework of cognitive science that are exceptions to this rule. Nevertheless, even these uses—so he argues— are at odds in important ways with the standard (folk psychological) interpretation of what being a representation amounts to (chapter 2). Against this backdrop, in making his core argument he is critical of the popular tendency to regard representations as states (or ensembles of states) that only are reliably caused by (or nomically depend upon) the occurrence of certain external features (chapter 4) or those that dispositionally produce certain effects under specific conditions (chapter 5). He classifies these sorts of theory as subscribing to what he designates, respectively, ‘‘receptor’’ and ‘‘tacit’’ notions of representation. These ideas come into play, on the one hand, when scientists speak of states or processes that serve as ‘‘detectors’’ or ‘‘indicators’’ of some external feature or other, or on the other hand, when they talk of a system or organism’s implicit or embodied ‘‘know how’’ as being responsible for generating reliable effects. Subjecting these accounts to a detailed analysis, Ramsey demonstrates that both the receptor and tacit notions of representation—those favored by today’s


Journal ArticleDOI
TL;DR: It is suggested that meaningful information about multimodal aspects of real-world materials reside in the ventral cortex around the fusiform gyrus, where it can be utilized for categorization of materials.

Journal ArticleDOI
TL;DR: Agarwal et al. as discussed by the authors presented a graph-based representation of proteins as walk-in-space and higher-order AA Adjacency-count matrices for protein alignment.
Abstract: 6.8. Protein Profiles 823 7. Spectrum-like Representation of Proteins 824 8. Graphical Approach to Protein Alignment 825 9. Nongraphical Representation of Proteins 828 9.1. Representation of Proteins as Walks in Space 828 9.2. Protein Descriptors 829 10. Most Recent Results 830 10.1. Amino Acid Adjacency-Count Matrix 830 10.2. Higher-Order AA Adjacency-Count Matrices 834 10.3. Simplified Graphical Representations of Proteins 834

Proceedings ArticleDOI
David Pfeiffer1, Uwe Franke1
01 Jan 2011
TL;DR: This work presents a novel reconstruction of stereo vision data that allows to incorporate real-world constraints such as perspective ordering and delivers an optimal segmentation with respect to freespace and obstacle information.
Abstract: Dense 3D data as delivered by stereo vision systems, modern laser scanners or timeof-flight cameras such as PMD is a key element for 3D scene understanding. Real-time high-level vision systems require a compact and explicit representation of that data which allows for efficient attention control, object detection, and reasoning. Because man-made environments are dominated by planar horizontal and vertical surfaces we approximate the three dimensional scenery by using sets of thin planar rectangles called Stixels. This medium level representation serves as input for further processing steps and applications. Using this novel representation those are not required to process the large amounts of raw 3D data individually. This reconstruction is addressed by means of a unified probabilistic approach. Dynamic programming allows to incorporate real-world constraints such as perspective ordering and delivers an optimal segmentation with respect to freespace and obstacle information. We present results for both stereo vision data and laser data. The real-time capable approach can also be used to fuse the information of multiple data sources.

Patent
Ying Chen1, Marta Karczewicz1
18 Feb 2011
TL;DR: In this paper, an apparatus includes a processor configured to provide information to a client device for accessing data for a first representation of a video sequence and a second representation of the video sequence, and the client device can use the information to perform seamless switching between the representations.
Abstract: In one example, an apparatus includes a processor configured to provide information to a client device for accessing data for a first representation of a video sequence and a second representation of the video sequence, and to provide information to the client device indicating that the client device can, during transmission of the data for the first representation, switch to the second representation without experiencing a presentation gap when displaying the video sequence and without simultaneously executing more than one decoder to decode the data for the first representation and the second representation during the switch, in response to a first request from the client device to retrieve data from the first representation. In this manner, the client device may use the information to perform seamless switching between the representations.

Journal ArticleDOI
TL;DR: In this paper, the notion of n-representation-finite hereditary algebras was introduced and a combinatorial description of the n-APR tilting procedure was given.
Abstract: We introduce the notion of n-representation-finiteness, generalizing representationfinite hereditary algebras. We establish the procedure of n-APR tilting, and show that it preserves n-representation-finiteness. We give some combinatorial description of this procedure, and use this to completely describe a class of n-representation-finite algebras called “type A”.

Journal ArticleDOI
TL;DR: The article presents a general classification of the models being developed in the area of sustainability arguing that the existing models represent the historical conceptualisation of sustainability starting from environmental constraints and moving towards economic valuation and social behaviour and policies.

Patent
David Petrou1
27 Jul 2011
TL;DR: In this paper, a head-mounted display (HMD) displays a visual representation of a physical interaction with an input interface that is located outside of the field of view (FOV).
Abstract: A head-mounted display (HMD) displays a visual representation of a physical interaction with an input interface that is located outside of the field of view. In one embodiment, the visual representation includes symbols that indicate when close proximity or physical contact is made with the input interface. In another embodiment, the visual representation is a simulation of the physical interaction with the input interface. The visual representation displayed by the HMD can beneficially enable the wearer to interact with the input interface more efficiently.


Dissertation
01 Jan 2011
TL;DR: It is easier to discriminate between an apple and a pear as between two types of pears, which suggests that the neural representation of object categories is plastic, and changes as a result of experience.
Abstract: Een wetenschappelijke proeve op het gebied van de sociale wetenschappen Proefschrift ter verkrijging van de graad van doctor aan de Radboud Universiteit Nijmegen op gezag van de rector magnificus prof. mr. Contents Chapter 1 General introduction and outline 9 Chapter 2 Birds of a feather flock together: Experience-driven formation of visual object categories in human ventral temporal cortex 21 Chapter 3 Formation of category representations in superior temporal sulcus 4 3 Chapter 4 Category training induces crossmodal object representations in the adult human brain 6 1 Chapter 5 Task-and experience-dependent cortical selectivity to features informative for categorization 8 5 Chapter 6 Summary and discussion 107 Chapter 7 Nederlandse samenvatting 113 Acknowledgements 122 Biography 123 List of publications 123 Donders Graduate School for Cognitive Neuroscience Series 124 General introduction and outline 1 10 General introduction and outline R ecognizing objects and categorizing them starts already at a very young age and continues throughout adulthood. Experience continuously shapes the borders of existing categories and creates even entirely new categories. As such we can easily assign a novel instance of a known object to its category and at the same time we can discriminate between objects that look similar but are in fact different exemplars of the same category e.g. a pear and an apple. This shows that our visual system is capable of both generalization and discrimination. These are the key points of categorization. Moreover, when more skilled in recognizing fruit, for example because of working in the fruit department of a grocery store, one might even be able to distinguish a Bartlett pear from an Anjou pear (Fig 1.1). This suggests that the neural representation of object categories is plastic, and changes as a result of experience. The research in this thesis was designed to investigate experience-dependent plasticity in the representation of object categories. In the experiments in this thesis subjects were trained to differentiate between categories of computer-generated birds (Chapters 2, 3, and 4) and fish (Chapter 5). These stimuli are very difficult to distinguish without any form of training. We used behavioural measures in combination with a non-invasive brain imaging technique (functional magnetic resonance imaging, see box 1) to get insight on experience-based changes in cortical representations. Figure 1.1 It is easier to discriminate between an apple and a pear as between two types of pears. Categorization Categorization takes place at several levels of abstraction (Rosch, Mervis, Gray, Johnson, …

Journal ArticleDOI
TL;DR: A new approach for visual object tracking based on Sample-Based Adaptive Sparse Representation (AdaSR), which ensures that the tracked object is adaptively and compactly expressed with predefined samples, which is better than those of several representative tracking methods.

Journal ArticleDOI
TL;DR: This reply to Jane Mansbridge is argued in favor of concepts that emphasize one side or other of a relationship, rather than treating both sides simultaneously, defending the view that “promissory” and “anticipatory” may usefully describe the activity of “representing” but ought to emphasize only one side of the representative–voter relationship.
Abstract: In this reply to Jane Mansbridge's “Clarifying the Concept of Representation” in this issue (American Political Science Review 2011). I argue that our main disagreements are conceptual, and are traceable to the attempt to treat the concept of representation as a “single highly complex concept” as Hanna Pitkin once put it. Instead, I argue, it would be more useful to develop the various concepts that emphasize the underlying forms of representation. Against the view that empirical regularity should guide concept formation, I suggest that the failure to find instances of the cases I conceptualize is not itself a reason to reject them. Instead, I argue in favor of concepts that emphasize one side or other of a relationship, rather than treating both sides simultaneously, defending the view that “promissory” and “anticipatory” may usefully describe the activity of “representing” but ought to emphasize only one side of the representative–voter relationship. I also explain why adding substantive accounts of representation to any of Mansbridge's modifying concepts dilutes their practical value. I conclude by indicating the importance of developing concepts that stretch beyond the democratic contexts that feature prominently in her response.

Patent
08 Aug 2011
TL;DR: In this article, a computing apparatus is configured to identify a set of users; identify a plurality of triggers, each of which corresponds to a set which when satisfied by a transaction of a user from the set, as the transaction is being processed by the transaction handler, causes transmission of an advertisement to the user; provide a graphical representation of triggers; and provide data related to the triggers on the graphical representation.
Abstract: In one aspect, a computing apparatus is configured to identify a set of users; identify a plurality of triggers, each of which corresponds to a set of one or more conditions which when satisfied by a transaction of a user from the set, as the transaction is being processed by the transaction handler, causes transmission of an advertisement to the user; provide a graphical representation of triggers; and provide data related to the triggers on the graphical representation, in response to user interaction with the graphical representation.

Patent
11 Jul 2011
TL;DR: In this article, a method and a system for 3D modeling of a 3D object (724) adapted to be inserted in or worn by a patient is described, which applies information of one or more features from an acquired 2D digital representation comprising textural data.
Abstract: 3D modeling of an object using textural features. Disclosed is a method and a system (720) for 3D modeling of a 3D object (724) adapted to be inserted in or worn by a patient. The 3D modeling applies information of one or more features from an acquired 2D digital representation comprising textural data of the location where the 3D object (724) is adapted to be arranged.

Patent
29 Dec 2011
TL;DR: In this article, the authors present a set of methods for generating heat maps of event data, which can be classified into three categories: discrete decomposition, at least one constraint, and heat map generation.
Abstract: Systems, methods, and media for generating heat maps of event data are provided herein. Methods may include gathering instances of event data according to a performance characteristic, discretely decomposing the instances by applying at least one constraint to the instances, assigning a hue to each instance, the hue being associated with the at least one constraint, and generating a heat map that includes representations of the instances, wherein each representation includes the hue associated with the at least one constraint to which the instance has been assigned.

Journal ArticleDOI
TL;DR: An account of scientific representation in terms of partial structures and partial morphisms is further developed in this paper, which addresses a variety of difficulties and challenges that have recently been raised against such formal accounts of representation.
Abstract: An account of scientific representation in terms of partial structures and partial morphisms is further developed. It is argued that the account addresses a variety of difficulties and challenges that have recently been raised against such formal accounts of representation. This allows some useful parallels between representation in science and art to be drawn, particularly with regard to apparently inconsistent representations. These parallels suggest that a unitary account of scientific and artistic representation is possible, and our article can be viewed as laying the groundwork for such an account— although, as we shall acknowledge, significant differences exist between these two forms of representation.

Proceedings ArticleDOI
09 May 2011
TL;DR: This work presents a framework that combines two approaches to grasp planning based on perceived sensor data of an object, aiming to find consensus on how the object should be grasped by using the information from each object representation according to their confidence levels.
Abstract: Grasp planning based on perceived sensor data of an object can be performed in different ways, depending on the chosen semantic interpretation of the sensed data. For example, if the object can be recognized and a complete 3D model is available, a different planning tool can be selected compared to the situation in which only the raw sensed data, such as a single point cloud, is available. Instead of choosing between these options, we present a framework that combines them, aiming to find consensus on how the object should be grasped by using the information from each object representation according to their confidence levels. We show that this method is robust to common errors in perception, such as incorrect object recognition, while also taking into account potential grasp execution errors due to imperfect robot calibration. We illustrate this method on the PR2 robot by grasping objects common in human environments.

01 Jan 2011
TL;DR: This paper presents the design of an annotation language, meant to be used either as an intermediate representation within library generators or directly by the programmer, that represents parameterized programs in a compact and natural way.
Abstract: As processor complexity increases compilers tend to deliver suboptimal performance. Library generators such as ATLAS, FFTW and SPIRALz overcome this issue by empirically searching in the space of possible program versions for the one that performs the best. Empirical search can also be applied by programmers, but because they lack a tool to automate the process, programmers need to manually re-write the application in terms of several parameters whose best value will be determined by the empirical search in the target machine. In this paper, we present the design of an annotation language, meant to be used either as an intermediate representation within library generators or directly by the programmer. This language that we call X represents parameterized programs in a compact and natural way. It provides an powerful optimization framework for high performance computing.

Journal ArticleDOI
TL;DR: The findings showed that 4-year-olds performed more accurately on go trials in the inhibition phase with transparent cues than with arbitrary cues, suggesting that goal representation is a key element for efficient executive function across a variety of settings involving different executive functions.