Showing papers on "Representation (systemics) published in 2004"

Learning to detect objects in images via a sparse, part-based representation

Abstract: We study the problem of detecting objects in still, gray-scale images. Our primary focus is the development of a learning-based approach to the problem that makes use of a sparse, part-based representation. A vocabulary of distinctive object parts is automatically constructed from a set of sample images of the object class of interest; images are then represented using parts from this vocabulary, together with spatial relations observed among the parts. Based on this representation, a learning algorithm is used to automatically learn to detect instances of the object class in new images. The approach can be applied to any object with distinguishable parts in a relatively fixed spatial configuration; it is evaluated here on difficult sets of real-world images containing side views of cars, and is seen to successfully detect objects in varying conditions amidst background clutter and mild occlusion. In evaluating object detection approaches, several important methodological issues arise that have not been satisfactorily addressed in the previous work. A secondary focus of this paper is to highlight these issues, and to develop rigorous evaluation standards for the object detection problem. A critical evaluation of our approach under the proposed standards is presented.

Revisiting Snodgrass and Vanderwart's object pictorial set : the role of surface detail in basic-level object recognition

Abstract: Theories of object recognition differ to the extent that they consider object representations as being mediated only by the shape of the object, or shape and surface details, if surface details are part of the representation. In particular, it has been suggested that color information may be helpful at recognizing objects only in very special cases, but not during basic-level object recognition in good viewing conditions. In this study, we collected normative data (naming agreement, familiarity, complexity, and imagery judgments) for Snodgrass and Vanderwart's object database of 260 black-and-white line drawings, and then compared the data to exactly the same shapes but with added gray-level texture and surface details (set 2), and color (set 3). Naming latencies were also recorded. Whereas the addition of texture and shading without color only slightly improved naming agreement scores for the objects, the addition of color information unambiguously improved naming accuracy and speeded correct response times. As shown in previous studies, the advantage provided by color was larger for objects with a diagnostic color, and structurally similar shapes, such as fruits and vegetables, but was also observed for man-made objects with and without a single diagnostic color. These observations show that basic-level 'everyday' object recognition in normal conditions is facilitated by the presence of color information, and support a 'shape + surface' model of object recognition, for which color is an integral part of the object representation. In addition, the new stimuli (sets 2 and 3) and the corresponding normative data provide valuable materials for a wide range of experimental and clinical studies of object recognition.

The body schema and multisensory representation(s) of peripersonal space

Abstract: To guide the movement of the body through space, the brain must constantly monitor the position and movement of the body in relation to nearby objects. The effective piloting of the body to avoid or manipulate objects in pursuit of behavioural goals requires an integrated neural representation of the body (the ‘body schema’) and of the space around the body (‘peripersonal space’). In the review that follows, we describe and evaluate recent results from neurophysiology, neuropsychology, and psychophysics in both human and non-human primates that support the existence of an integrated representation of visual, somatosensory, and auditory peripersonal space. Such a representation involves primarily visual, somatosensory, and proprioceptive modalities, operates in body-part-centred reference frames, and demonstrates significant plasticity. Recent research shows that the use of tools, the viewing of one’s body or body parts in mirrors, and in video monitors, may also modulate the visuotactile representation of peripersonal space.

What is an auditory object

Abstract: Objects are the building blocks of experience, but what do we mean by an object? Increasingly, neuroscientists refer to 'auditory objects', yet it is not clear what properties these should possess, how they might be represented in the brain, or how they might relate to the more familiar objects of vision. The concept of an auditory object challenges our understanding of object perception. Here, we offer a critical perspective on the concept and its basis in the brain.

Mapping tool graphical user interface

Abstract: A graphical user interface and method for creating a mapping between a source object and a destination or target object are provided. The user interface includes a source screen region which displays a graphical representation of a source object, a target screen region which displays a graphical representation of a target object, and a mapping screen region which allows a user to create a mapping between the graphical representation of the source object and the graphical representation of the target object using graphical mapping indicia. The methodology includes displaying a graphical representation of a source object in a source screen region, displaying a graphical representation of a target object in a target screen region, creating a mapping between the graphical representation of the source object and the graphical representation of the target object in a mapping screen region using graphical mapping indicia, and displaying the mapping in the mapping screen region. The source and target objects may be schemas, spreadsheets, documents, databases, or other information sources, and the graphical mapping indicia may include link indicia and/or function objects linking nodes in the target object with nodes in the source object. The mapping may be compiled into code used by a runtime engine to translate source documents into target documents.

Diagrammatic Representation and Inference

Abstract: The beauty of logical graphs consists in many facets, including notational simplicity, multi-modality and normativity. This paper aims at understanding the nature of Peirce’s graphical method and its implications to philosophy of logic.

Management of conversations

Abstract: In one aspect, an arbitrary natural language communication is received from a user. A concept recognition process is applied to automatically derive a representation of concepts embodied in the communication. The concept representation is used to provide to a human agent information useful in responding to the natural language communication.

A century of cerebellar somatotopy: a debated representation

Abstract: The existence of functional localization within the cerebellum was advanced exactly one century ago by both comparative anatomical and physiological studies. Here, we will discuss how models of cerebellar localization have evolved over the last 100 years. Like the somatotopic representation in neocortical sensorimotor areas, the representation size of different body parts in the cerebellum does not reflect their peripheral extent, but rather the different demands on the sensory inputs for different movements.

On the American Option Problem

Abstract: We show how the change-of-variable formula with local time on curves derived recently in Peskir (2002) can be used to prove that the optimal stopping boundary for the American put option can be characterized as the unique solution of a nonlinear integral equation arising from the early exercise premium representation. This settles the question raised in Myneni (1992) and dating back to McKean (1965).

Ability to Translate from One Representation of the Concept of Function to Another and Mathematical Problem Solving

Abstract: Representations are used extensively in mathematics and translation ability is highly correlated with success in mathematics education. The authors investigate the translation ability of university students as far as the concept of function is concerned. The research focuses on the relationship between success in, solving direct translation tasks and success in solving problems by articulating different representations of the concept of function. Furthermore, it examines the relationship between student performance and the nature of the representation included in the translation task. The ability to pass from one representation to another was associated with success in problem solving. These results indicate that translation ability should be considered as an important factor in problem solving. Percentages are lower when an iconic representation is included in the translation task. This could be partly attributed to the holistic nature of iconic representations and to the way the concept of function is t...

A Bayesian Framework for Multi-cue 3D Object Tracking

Abstract: This paper presents a Bayesian framework for multi-cue 3D object tracking of deformable objects. The proposed spatio-temporal object representation involves a set of distinct linear subspace models or Dynamic Point Distribution Models (DPDMs), which can deal with both continuous and discontinuous appearance changes; the representation is learned fully automatically from training data. The representation is enriched with texture information by means of intensity histograms, which are compared using the Bhattacharyya coefficient. Direct 3D measurement is furthermore provided by a stereo system.

Printable representations for time-based media

Abstract: The system of the present invention allows a user to generate a representation of time-based media. The system of the present invention includes a feature extraction module for extracting features from media content. For example, the feature extraction module can detect solos in a musical performance, or can detect music, applause, speech, and the like. A formatting module formats a media representation generated by the system. The formatting module also applies feature extraction information to the representation, and formats the representation according to a representation specification. In addition, the system can include an augmented output device that generates a media representation based on the feature extraction information and the representation specification. The methods of the present invention include extracting features from media content, and formatting a media representation being generated using the extracted features and based on a specification or data structure specifying the representation format. The methods can also include generating a media representation based on the results of the formatting.

User interface to display and manage an entity and associated resources

Abstract: A user interface to display and manage a plurality of entities as if a single entity is provided. The user interface includes a representation of the collection of entities as a whole, and a representation of members associated with the entity. If an action is performed on the representation of the entities as a whole, then the action is propagated to the collection of entities, if the action is performed on the representation of the member associated with the entity, then the action is directed to the member.

The nature of foveal representation

Abstract: A fundamental question in visual perception is whether the representation of the fovea is split at the midline between the two hemispheres, or bilaterally represented by overlapping projections of the fovea in each hemisphere. Here we examine psychophysical, anatomical, neuropsychological and brain stimulation experiments that have addressed this question, and argue for a shift from the current default view of bilateral representation to that of a split representation, to provide a greater understanding of higher visual processes.

Aggregation bias in macro models: does it matter foir the euro area?

Abstract: The euro area represents a case-study of great institutional relevance for the econometric problem of aggregation bias. The available data can be used to analyze the area either with aggregate or with country-specific models. The choice should be the result of a statistical comparison between the two options, with respect to the specific model. In this paper we suggest a representation of the aggregation error based on unobservable components and explicitly conceived for aggregations over a small number of economies. In the empirical application two alternative models are estimated: the first specifies the main euro countries while the other refers to the whole area. We then evaluate the aggregation error either from the viewpoint of a comparison of the two models with standard methods, or looking at the components of the representation suggested here. Both categories of results indicate non-negligible aggregation errors for the euro area.

Agent Learning Representation - Advice in Modelling Economic Learning

Abstract: This paper presents an overview on the existing learning models in the economic literature. Furthermore, it discusses which of these models should be used under what circumstances and how adequate learning models can be chosen in simulation approaches. It gives advice for getting along with the many models existing and picking the right one for the own application.

Learning to Detect Objects in Images via a Sparse, Part-Based Representation

Abstract: We study the problem of detecting objects in still, gray-scale images. Our primary focus is the development of a learning- based approach to the problem that makes use of a sparse, part-based representation. A vocabulary of distinctive object parts is automatically constructed from a set of sample images of the object class of interest; images are then represented using parts from this vocabulary, together with spatial relations observed among the parts. Based on this representation, a learning algorithm is used to automatically learn to detect instances of the object class in new images. The approach can be applied to any object with distinguishable parts in a relatively fixed spatial configuration; it is evaluated here on difficult sets of real-world images containing side views of cars, and is seen to successfully detect objects in varying conditions amidst background clutter and mild occlusion. In evaluating object detection approaches, several important methodological issues arise that have not been satisfactorily addressed in previous work. A secondary focus of this paper is to highlight these issues and to develop rigorous evaluation standards for the object detection problem. A critical evaluation of our approach under the proposed standards is presented.

An extension and analysis of the Shu-Osher representation of Runge-Kutta methods

Abstract: In the context of solving nonlinear partial differential equations, Shu and Osher introduced representations of explicit Runge-Kutta methods, which lead to stepsize conditions under which the numerical process is total-variation-diminishing (TVD). Much attention has been paid to these representations in the literature. In general, a Shu-Osher representation of a given Runge-Kutta method is not unique. Therefore, of special importance are representations of a given method which are best possible with regard to the stepsize condition that can be derived from them. Several basic questions are still open, notably regarding the following issues: (1) the formulation of a simple and general strategy for finding a best possible Shu-Osher representation for any given Runge-Kutta method; (2) the question of whether the TVD property of a given Runge-Kutta method can still be guaranteed when the stepsize condition, corresponding to a best possible Shu-Osher representation of the method, is violated; (3) the generalization of the Shu-Osher approach to general (possibly implicit) Runge-Kutta methods. In this paper we give an extension and analysis of the original Shu-Osher representation, by means of which the above questions can be settled. Moreover, we clarify analogous questions regarding properties which are referred to, in the literature, by the terms monotonicity and strong-stability-preserving (SSP).

3-D graphical representation of DNA sequences and their numerical characterization

Abstract: We introduce a 3-D graphical representation of DNA sequences, L-curve. L-curve also avoids loss of information accompanying alternative 2-D and 3-D representation in which the curve standing for DNA overlaps and intersects itself. The method is illustrated on the coding sequence of the first exon of human β-globin gene.

Should research samples reflect the diversity of the population

Abstract: Recent research governance documents say that the body of research evidence must reflect population diversity. The response to this needs to be more sophisticated than simply ensuring minorities are present in samples. For quantitative research looking primarily at treatment effects of drugs and devices four suggestions are made. First, identify where the representation of minorities in samples matters—for example, where ethnicity may cause different treatment effects. Second, where the representation of a particular group matters then subgroup analysis of the results will usually be necessary. Third, ensuring representation and subgroup analysis will have costs; deciding on whether such representation is worthwhile will involve cost benefit analysis. Fourth, the representation of minorities should not be seen as mainly a locality issue. For qualitative research it is argued that the representation of diversity is often important. Given the small samples of many qualitative projects, however, the best way to ensure representation occurs is to allow a proliferation of such research, not to stipulate such representation in samples.

Low and Medium Level Vision Using Channel Representations

Abstract: This thesis introduces and explores a new type of representation for low and medium level vision operations called channel representation The channel representation is a more general way to repres

Intelligent Information Integration for the Semantic Web

Abstract: and Related Work.- Related Work.- The Buster Approach for Terminological, Spatial, and Temporal Representation and Reasoning.- General Approach of Buster.- Terminological Representation and Reasoning, Semantic Translation.- Spatial Representation and Reasoning.- Temporal Representation and Reasoning.- Implementation, Conclusion, and Future Work.- Implementation Issues and System Demonstration.- Conclusion and Future Work.- References.

The Architecture of Computerized Business Gaming Simulations

Abstract: Advances in the design of computerized business gaming simulations since the earliest works of the late 1950s are reviewed. A taxonomy of computerized gaming simulation is discussed, and the role of purpose in design is considered. Issues with respect to the representation, timing, hosting, and scoring of gaming simulations are covered.

Visuo-tactile representation of near-the-body space.

Abstract: Here we report findings from neuropsychological investigations showing the existence, in humans, of intersensory integrative systems representing space through the multisensory coding of visual and tactile events. In addition, these findings show that visuo-tactile integration may take place in a privileged manner within a limited sector of space closely surrounding the body surface, i.e., the near-peripersonal space. They also demonstrate that the representation of near-peripersonal space is not static, as objects in the out-of-reach space can be processed as nearer, depending upon the (illusory) visual information about hand position in space, and the use of tools as physical extensions of the reachable space. Finally, new evidence is provided suggesting the multisensory coding of peripersonal space can be achieved through bottom-up processing that, at least in some instances, is not necessarily modulated by more "cognitive" top-down processing, such as the expectation regarding the possibility of being touched. These findings are entirely consistent with the functional properties of multisensory neuronal structures coding near-peripersonal space in monkeys, as well as with behavioral, and neuroimaging evidence for the cross-modal coding of space in normal subjects. This high level of convergence ultimately favors the idea that multisensory space coding is achieved through similar multimodal structures in both humans and non-human primates.

Understanding Primes: The Role of Representation.

Abstract: In this article we investigate how preservice elementary school (K‐7) teachers understand the concept of prime numbers. We describe participants’ understanding of primes and attempt to detect factors that influence their understanding. Representation of number properties serves as a lens for the analysis of participants’ responses. We suggest that an obstacle to the conceptual understanding of primality of numbers is the lack of a transparent representation for a prime number.

Object Updating and the Flash-Lag Effect

Abstract: Flash lag is a misperception of spatial relations between a moving object and a briefly flashed stationary one. This study began with the observation that the illusion occurs when the moving object continues following the flash, but is eliminated if the object's motion path ends with the flash. The data show that disrupting the continuity of the moving object, via a transient change in size or color, also eliminates the illusion. We propose that this is because a large feature change leads to the formation of a second object representation. Direct evidence for this proposal is provided by the results for a corollary perceptual feature of the disruption in object continuity: the perception of two objects, rather than only one, on the motion path.