ppxscal/embedding_network huggingface dataset:
Aperiodic dynamics and the self-organization of cognitive maps in autonomous agents: Research Articles
Authors: Derek Harter, Robert Kozma
Venue: International Journal of Intelligent Systems (2006)

When we look at the dynamics produced by biological neuronal populations, we are immediately struck by the fact that aperiodic, chaotic-like dynamics appear to be the normal operating state of such systems. Recent work has shown that such aperiodic dynamics, at least in perceptual systems, may not only be the result of random perturbations experienced by the system from external stimulation, but that the brain itself generates aperiodic dynamics to deal more flexibly and reliably with noisy environmental stimulation. Complex systems concepts are helping us to understand the properties of nonlinear systems that are fundamental for the emergence of complex spatiotemporal patterns in natural and biological systems. Advances in neuroscience and computational neurodynamics are applying these concepts of self-organization to understanding the spatiotemporal patterns observed in biological brains. In this article, we introduce a neural population model that is capable of replicating the generation of these types of aperiodic dynamics observed in biological brains. We use the model to self-organize cognitive maps in an autonomous agent through the agent's interaction with its environment. We show how such high-dimensional spatiotemporal dynamics may be shaped by environmental input and learning to form chaotic attractors that come to represent &ldquo;meanings&rdquo; for the agent. We discuss how the internal generation of such aperiodic dynamics may aid in the formation and recognition of such noisy environmental stimuli in biological organisms in general and in our simulated agents specifically. &copy; 2006 Wiley Periodicals, Inc. Int J Int Syst 21: 955&ndash;971, 2006.
IEIP: An Inter-Enterprise Integration Platform for e-Commerce Based on Web Service Mediation
Authors: Suo Cong, Ela Hunt, Klaus R. Dittrich
Venue: Proceedings of the European Conference on Web Services (2006)

Cross-platform interoperability of web services makes it possible to wrap and combine information assets from heterogeneous systems to create a consolidated application. Here we propose a new pragmatic architectural model using web services as building blocks, to form an interenterprise integration platform for e-commerce. The key idea is to separate the view of a web service defined by its provider from the views of this web service employed by consumers. Based on this principle, we explain the use of web service mediators which act on behalf of both service providers and consumers. We advance the notion of requester-based views of a web service, which are published by a mediator and used by service providers to construct services that suit the consumer. To complement those, we use customer-oriented global views which express the information need of a customer. IEIP architecture improves on traditional data and enterprise service integration systems. It achieves the following two goals: a customer can use its own (private) view to access a number of different web services, as it is using a global view; and a provider can provide one view for a service implementation that can be accessed by different requesters using different global views. Leveraging this model, we report on a prototype supporting a European-wide parking services platform that integrates data and services from a large number of parking providers.
Dissociations of Face and Object Recognition in Developmental Prosopagnosia
Authors: Brad Duchaine, Ken Nakayama
Venue: Journal of Cognitive Neuroscience (2005)

Neuropsychological studies with patients suffering from prosopagnosia have provided the main evidence for the hypothesis that the recognition of faces and objects rely on distinct mechanisms. Yet doubts remain, and it has been argued that no case demonstrating an unequivocal dissociation between face and object recognition exists due in part to the lack of appropriate response time measurements (Gauthier et al., 1999). We tested seven developmental prosopagnosics to measure their accuracy and reaction times with multiple tests of face recognition and compared this with a larger battery of object recognition tests. For our systematic comparison, we used an old/new recognition memory paradigm involving memory tests for cars, tools, guns, horses, natural scenes, and houses in addition to two separate tests for faces. Developmental prosopagnosic subjects performed very poorly with the face memory tests as expected. Four of the seven prosopagnosics showed a very strong dissociation between the face and object tests. Systematic comparison of reaction time measurements for all tests indicates that the dissociations cannot be accounted for by differences in reaction times. Contrary to an account based on speed accuracy tradeoffs, prosopagnosics were systematically faster in nonface tests than in face tests. Thus, our findings demonstrate that face and nonface recognition can dissociate over a wide range of testing conditions. This is further support for the hypothesis that face and nonface recognition relies on separate mechanisms and that developmental prosopagnosia constitutes a disorder separate from developmental agnosia.
Dissociating Task-set Selection from Task-set Inhibition in the Prefrontal Cortex
Authors: Ulrich Mayr, Jörn Diedrichsen, Richard Ivry, Steven W. Keele
Venue: Journal of Cognitive Neuroscience (2006)

Patients with focal lesions in the left (n = 7) and right (n = 4) prefrontal cortex were compared with controls (n = 16) in a task-switching experiment using four different, simple spatial tasks. Each of these tasks involved a left&ndash;right decision, either regarding an arrow, the word "left" or "right," a circle position, or the direction of a moving line. We compared performance on trials that required rule switches versus rule repetitions (local switch costs) and we compared performance between blocks with bivalent stimuli (two dimensions present) and blocks with univalent stimuli (only one dimension present) to assess global switch costs. Patients with left prefrontal lesions, but not patients with right prefrontal lesions, exhibited increased costs on trials in which the relevant dimension switched (local switch costs), but also on no-switch trials with bivalent stimuli (global costs). We also assessed task-set inhibition in the form of the backward-inhibition effect [increased response times to recently abandoned tasks; Mayr, U., & Keele, S. Changing internal constraints on action: The role of backward inhibition. Journal of Experimental Psychology: General, 129, 4&ndash;26, 2000]. Although left frontal patients showed normal inhibition, right frontal patients showed no evidence for inhibition. These results suggest a neurocognitive dissociation between task-set selection and inhibition.
Stacked Euler Vector (SERVE): A Gray-Tone Image Feature Based on Bit-Plane Augmentation
Authors: Arijit Bishnu Bhargab B. Bhattacharya
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (2007)

A new combinatorial feature called Stacked Euler Vector (SERVE) is introduced to characterize a gray-tone image. SERVE comprises a four-tuple, where each element is an integer representing the Euler number of the partial binary image formed by certain pixel overlap relations among the four most significant bit planes of the gray-tone image. Computation of SERVE is simple, fast, and does not involve any floating point operation. SERVE can be used to augment other features to improve the performance of image retrieval significantly. Experimental results on the COIL database are reported to demonstrate its performance.
A Neural Network Model of Lateralization during Letter Identification
Authors: Natalia Shevtsova, James A. Reggia
Venue: Journal of Cognitive Neuroscience (1999)

The causes of cerebral lateralization of cognitive and other functions are currently not well understood. To investigate one aspect of function lateralization, a bihemispheric neural network model for a simple visual identification task was developed that has two parallel interacting paths of information processing. The model is based on commonly accepted concepts concerning neural connectivity, activity dynamics, and synaptic plasticity. A combination of both unsupervised (Hebbian) and supervised (Widrow-Hoff) learning rules is used to train the model to identify a small set of letters presented as input stimuli in the left visual hemifield, in the central position, and in the right visual hemifield. Each visual hemifield projects onto the contralateral hemisphere, and the two hemispheres interact via a simulated corpus callosum. The contribution of each individual hemisphere to the process of input stimuli identification was studied for a variety of underlying asymmetries. The results indicate that multiple asymmetries may cause lateralization. Lateralization occurred toward the side having larger size, higher excitability, or higher learning rate parameters. It appeared more intensively with strong inhibitory callosal connections, supporting the hypothesis that the corpus callosum plays a functionally inhibitory role. The model demonstrates clearly the dependence of lateralization on different hemisphere parameters and suggests that computational models can be useful in better understanding the mechanisms underlying emergence of lateralization.
Maximum likelihood estimation of spectral moments at low signal to noise ratios
Authors: J. M. B. Dias, J. M. N. Leitao
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1993. ICASSP-93 Vol 4., 1993 IEEE International Conference on - Volume 04 (1993)

A maximum likelihood (ML) estimator of spectral moments of a zero-mean complex Gaussian vector process, immersed in independent additive Gaussian white noise is proposed. The covariance function is assumed known in advance, apart from a vector of parameters which are related with the spectral moments. Since the maximization of the log-likelihood function yields a highly cumbersome algorithm, a more manageable objective function is considered. This objective function provides estimates consistent with probability one, and that are asymptotically efficient, which are the asymptotic properties of the ML estimator. For finite sample sizes, and signal to noise ratio (SNR) tending to zero, the results are similar to the ML results. Statistical characterization and simulation examples are presented.
Network Sensor and Its Application in Structure Health Monitoring System
Authors: Zhan-feng Gao, Yan-liang Du, Mu-biao Su, Biaoping Chen
Venue: Proceedings of the First International Conference on Innovative Computing, Information and Control - Volume 1 (2006)

Network sensor is a new sensing technique in which sensor signal is transferred into digital signal and transmitted on the basis of network protocol. The network sensor provides for the consolidation of analog signal conditioning and digital signal processing functions at the sensor, which results in system cost reductions, high reliability and improved performance. In order to improve the disadvantage of the traditional structure safety monitoring system, the principle and realization of a novel network sensor designed with A/D converter ADS8321, microprocessor Rabbit3000 and TCP/IP protocol are introduced. The structure health monitoring system (SHMS) based on network technique is discussed as wel1. The results show that the network sensor has the characteristics of great applicability, flexibility and high reliability. It represents the new development direction of the structure health monitoring system.
On pedagogically sound examples in public-key cryptography
Authors: Suan Khai Chong, Graham Farr, Laura Frost, Simon Hawley
Venue: Proceedings of the 29th Australasian Computer Science Conference - Volume 48 (2006)

Pencil-and-paper exercises in public-key cryptography are important in learning the subject. It is desirable that a student doing such an exercise does not get the right answer by a wrong method. We therefore seek exercises that are sound in the sense that a student who makes one of several common errors will get a wrong answer. Such exercises are difficult to construct by hand. This paper considers how to do so automatically, and describes software developed for this purpose, covering several popular cryptosystems (RSA, Difie-Hellman, Massey-Omura, ElGamal, Knapsack). We also introduce diagnostic exercises, in which all error paths lead to difierent answers, so that the answer given by the student may suggest the nature of their error. These too can be generated automatically by our software.
Type-safe distributed programming for OCaml
Authors: John Billings, Peter Sewell, Mark Shinwell, Rok Strniša
Venue: Proceedings of the 2006 workshop on ML (2006)

Existing ML-like languages guarantee type-safety, ensuring memory safety and protecting the invariants of abstract types, but only within single executions of single programs. Distributed programming is becoming ever more important, and should benefit even more from such guarantees. In previous work on theoretical calculi and the Acute prototype language we outlined techniques to provide them for simple languages.In this paper we put these ideas into practice, describing the HashCaml extension to the OCaml bytecode compiler, which supports type-safe and abstraction-safe marshalling, together with related naming constructs. Our contribution is threefold: (1) We show how to define globally meaningful runtime type names for key OCaml type constructs that were not covered in our previous work, dealing with the generativity issues involved: user-defined variant and record types, substructures, functors, arbitrary ascription, separate compilation, and external C functions. (2) We support marshalling within polymorphic functions by type-passing, requiring us to build compositional runtime type names and revisit the OCaml relaxed value restriction. We show that with typed marshalling one must fall back to the SML97 value restriction. (3) We show how the above can be implemented with reasonable performance as an unintrusive modification to the existing OCaml language, implementation, and standard libraries. An alpha release of HashCaml, capable of bootstrapping itself, is available, along with an example type-safe distributed communication library written in the language.
Coordinated perspectives and enhanced force-directed layout for the analysis of network motifs
Authors: Christian Klukas, Falk Schreiber, Henning Schwöbbermeyer
Venue: Proceedings of the 2006 Asia-Pacific Symposium on Information Visualisation - Volume 60 (2006)

The analysis of network motifs, patterns of local interconnections with potential functional properties, has applications in many fields of science. Network motif analysis is particularly important for the exploration of biological networks. The distribution and multiple occurrences of motifs in a network, complicated by dierent concepts for the determination of motif frequency, create various diculties in understanding and interpretation. We present a system that facilitates the analysis of network motifs by presenting co-ordinated perspectives simultaneously. A list of motifs supported by the network, visual representations of motifs of interest, a motif fingerprint and a visualisation of motif matches in the network are interwoven in a single interface. A motif and cluster-preserving force-directed layout algorithm supports the visual analysis of network motifs. This coordination of perspectives significantly enhances the explorative power of network motif analysis.
Lenient learners in cooperative multiagent systems
Authors: Liviu Panait, Keith Sullivan, Sean Luke
Venue: Proceedings of the fifth international joint conference on Autonomous agents and multiagent systems (2006)

In concurrent learning algorithms, an agent's perception of the joint search space depends on the actions currently chosen by the other agents. These perceptions change as each agent's action selection is influenced by its learning. We observe that agents that show lenience to their teammates achieve more accurate perceptions of the overall learning task. Additionally, lenience appears more beneficial at early stages of learning, when the agent's teammates are merely exploring their actions, and less helpful as the agents start to converge. We propose two multiagent learning algorithms where agents exhibit a variable degree of lenience, and we demonstrate their advantages in several coordination problems.
Hybrid control of a cart-pendulum system with restrictions on the travel
Authors: D. Gromov, J. Raisch
Venue: Proceedings of the 2003 International Conference on Physics and Control - Volume 4 (2003)

A globally stabilizing controller for a cart-pendulum system is developed. It is shown that the use of hybrid methods can significantly simplify the procedure of control synthesis in the presence of restrictions on the control signal and on the length of travel. A special feature of the proposed approach is that restrictions are embedded into the control algorithm.
Real Time Business Intelligence for the Adaptive Enterprise
Authors: B Azvine, Z Cui, D D. Nauck, B Majeed
Venue: Proceedings of the The 8th IEEE International Conference on E-Commerce Technology and The 3rd IEEE International Conference on Enterprise Computing, E-Commerce, and E-Services (2006)

In today's competitive environment, analysing data to predict market trends and to improve enterprise performance is an essential business activity. However, it is becoming clear that business success requires such data analysis to be carried out in real-time, and that actions in response to analysis results must also be performed in realtime in order to meet the rapid change in demand from customers and regulators alike. This paper discusses issues and problems of current business intelligence systems, and then outlines our vision of future real-time business intelligence. We present a list of emerging technologies that are being developed within the research program of British Telecommunications plc (BT), which could contribute to the realisation of real-time business intelligence, in addition to some examples of applying these technologies to improve BT's systems and services.
Iterative Methods for Linear Systems: Following the Meandering Way
Authors: Dianne P. O'Leary
Venue: Computing in Science and Engineering (2006)

Solving a linear system of equations is one of the easiest computational tasks imaginable, but when the matrix is very large, the algorithms we learned in linear algebra class take too long, and we need to use a different type of method. In this homework assignment, we investigate these iterative methods.
Traffic flow management modeling and operational complexity
Authors: Brendan Hogan, Leonard A. Wojcik
Venue: Proceedings of the 36th conference on Winter simulation (2004)

Traffic Flow Management (TFM) actions are commonly used to mitigate capacity/demand imbalances within the National Airspace System (NAS). Modeling TFM events has proven challenging in the past, partly because of weather forecast uncertainty, and partly because of the complexity and unpredictability associated with highly-interrelated traffic patterns and distributed decision-making in the NAS. In this paper, we present results of a simulation of a NAS TFM event in which weather effects are relatively small. This facilitates interpretation of the similarities and differences between simulation results and the actual event in terms of NAS operations and decision making, with relatively small weather-related complications. We conclude that TFM modeling shows promise as a tool to aid post-event TFM analysis, but the complex operational factors impose limits on the predictability of outcomes in TFM events. A CAASD-developed fast-time network simulation of the NAS was used for this analysis.
Securing Interaction between Threads and the Scheduler
Authors: Alejandro Russo, Andrei Sabelfeld
Venue: Proceedings of the 19th IEEE workshop on Computer Security Foundations (2006)

The problem of information flow in multithreaded programs remains an important open challenge. Existing approaches to specifying and enforcing information-flow security often suffer from over-restrictiveness, relying on non-standard semantics, lack of compositionality, inability to handle dynamic threads, scheduler dependence, and efficiency overhead for code that results from securityenforcing transformations. This paper suggests a remedy for some of these shortcomings by developing a novel treatment of the interaction between threads and the scheduler. As a result, we present a permissive noninterference-like security specification and a compositional security type system that provably enforces this specification. The type system guarantees security for a wide class of schedulers and provides a flexible and efficiency-friendly treatment of dynamic threads.
BFBR: A Novel Bird Flocking Behavior Based Routing for Highly Mobile Ad Hoc Networks
Authors: T. Srinivasan, T. Niranjan Babu, V. Mahadevan, M. Nivedita, G. Sahitya, A. Meyyappan, J. V. Sahana
Venue: Proceedings of the International Conference on Computational Inteligence for Modelling Control and Automation and International Conference on Intelligent Agents Web Technologies and International Commerce (2006)

Over the past decade, the field of Routing in Mobile Ad hoc networks has been the focus of intensive research. This paper proposes 'A novel Bird Flocking Behavior based Routing (BFBR) for Highly Mobile Ad hoc Networks (HMANET)' an efficient routing scheme with considerable advantages over previous attempts in this field. The general problem presented by HMANET is one of coordinating communication between nodes in settings in which the details of the connections to each other can change continuously, for which we apply the bird flocking behavior, where the individual agents with limited knowledge work synergistically in order to develop an intelligent system, which is executed in BFBR through an Encounter Search phenomenon. Also we leverage the characteristics of biological systems which exhibit complex, emergent behavior that is robust with respect to failure of individual entities in BFBR through an effective route maintenance which also takes care of high node mobility in HMANETs. Simulation results illustrate that BFBR scheme significantly improves the performance with respect to bandwidth usage.
A framework for standard modular simulation in semiconductor wafer fabrication systems
Authors: José A. Ramírez-Hernández, Heshan Li, Emmanuel Fernandez, Charles McLean, Swee Leong
Venue: Proceedings of the 37th conference on Winter simulation (2005)

This paper presents the application of a framework, proposed by the National Institute of Standards and Technology (NIST), for standard modular simulation in semiconductor wafer fabrication facilities (fabs). The application of the proposed framework resulted in the identification and specification of four different elements in the context of semiconductor fabs: (1) market sector, (2) hierarchical modeling levels, (3) simulation case studies, (4) models and data. An example of the application of the proposed simulation framework to a benchmark semiconductor fab model, the so-called Mini-fab, is presented. In this example, evaluation of production performance under different workforces is studied. Current and future research is focused on the improvement of the proposed framework (e.g., design and testing of generic case studies).