ppxscal/embedding_network huggingface dataset:
''What'' and ''Where'' in Visual Working Memory: A Computational Neurodynamical Perspective for Integrating fMRI and Single-Neuron Data
Authors: Gustavo Deco, Edmund T. Rolls, Barry Horwitz
Venue: Journal of Cognitive Neuroscience (2004)

Single-neuron recordings, functional magnetic resonance imaging (fMRI) data, and the effects of lesions indicate that the prefrontal cortex (PFC) is involved in some types of working memory and related cognitive processes. Based on these data, two different models of the topographical and functional organization of the PFC have been proposed: organization-by-stimulus-domain, and organization-by-process. In this article, we utilize an integrate-and-fire network to model both single-neuron and fMRI data on short-term memory in order to understand data obtained in topologically different parts of the PFC during working memory tasks. We explicitly model the mechanisms that underlie workingmemory-related activity during the execution of delay tasks that have a ''what''-then-''where'' design (with both object and spatial delayed responses within the same trial). The model contains different populations of neurons (as found experimentally) in attractor networks that respond in the delay period to the stimulus object, the stimulus position, and to combinations of both object and position information. The pools are arranged hierarchically and have global inhibition through inhibitory interneurons to implement competi tion. It is shown that a biasing attentional input to define the current relevant information (object or location) enables the system to select the correct neuronal populations during the delay period in what is a biased competition model of attention. The processes occurring at the AMPA and NMDA synapses are dynamically modeled in the integrate-and-fire implementation to produce realistic spiking dynamics. It is shown that the fMRI data characteristic of the dorsal PFC and linked to spatial processing and manipulation of items can be reproduced in the model by a high level of inhibition, whereas the fMRI data characteristic of the ventral PFC and linked to object processing can be produced by a lower level of inhibition, even though the network is itself topographically homogeneous with no spatial topology of the neurons. This article, thus, not only presents a model for how spatial versus object short-term memory could be implemented in the PFC, but also shows that the fMRI BOLD signal measured during such tasks from different parts of the PFC could reflect a higher level of inhibition dorsally, without this dorsal region necessarily being primarily spatial and the ventral region object-related.
Frontal Lobe Contributions to Theory of Mind
Authors: Valerie E. Stone, Simon Baron-cohen, Robert T. Knight
Venue: Journal of Cognitive Neuroscience (1998)

Theory of mind, the ability to make inferences about others' mental states, seems to be a modular cognitive capacity that underlies humans' ability to engage in complex social interaction. It develops in several distinct stages, which can be measured with social reasoning tests of increasing difficulty. Individuals with Asperger's syndrome, a mild form of autism, perform well on simpler theory of mind tests but show deficits on more developmentally advanced theory of mind tests. We tested patients with bilateral damage to orbito-frontal cortex (n = 5) and unilateral damage in left dorsolateral prefrontal cortex (n = 5) on a series of theory of mind tasks varying in difficulty. Bilateral orbito-frontal lesion patients performed similarly to individuals with Asperger's syndrome, performing well on simpler tests and showing deficits on tasks requiring more subtle social reasoning, such as the ability to recognize a faux pas. In contrast, no specific theory of mind deficits were evident in the unilateral dorsolateral frontal lesion patients. The dorsolateral lesion patients had difficulty only on versions of the tasks that placed demands on working memory.
Blueprint for an Autonomic Service Architecture
Authors: Ramy Farha, Alberto Leon-Garcia
Venue: Proceedings of the International Conference on Autonomic and Autonomous Systems (2006)

Next-generation service providers will offer an array of services and applications that is media-rich, personalized, and context-aware. In this future environment, new services and applications will be introduced, provisioned, operated, maintained, and retired at a pace that tracks changing customer requirements and demands. In order to be cost-effective, these services and applications need to be delivered over an all-IP infrastructure, which is autonomically managed to ensure their delivery at a satisfactory level for subscribed customers. In this paper, we propose a blueprint for a generic Autonomic Service Architecture (ASA) to address these challenges.
The Design of New Journaling File Systems: The DualFS Case
Authors: Juan Piernas, Toni Cortes, Jose M. Garcia
Venue: IEEE Transactions on Computers (2007)

This paper describes the foundation, design, implementation, and evaluation of DualFS, a new high-performance journaling file system which has the same consistency guarantees as traditional journaling file systems but a greater performance. DualFS places data and metadata in different devices (usually, two partitions of the same storage device) and manages them in very different ways. The metadata device is organized as a log-structured file system, whereas the data device is organized as groups. The new design allows DualFS not only to recover the consistency quickly after a system crash, but also to improve the overall file system performance. We have evaluated DualFS and we have found that it greatly reduces the total I/O time taken by the file system in most workloads as compared to other file systems (Ext2, Ext3, ReiserFS, XFS, and JFS). The work carried out has also allowed us to draw some lessons which ought to be taken into account when implementing new file systems.
BER Analysis of Bayesian equalization using orthogonal hyperplanes
Authors: Akrum Elkhazin, Konstantinos N. Plataniotis, Subbarayan Pasupathy
Venue: Signal Processing (2006)

Bayesian symbol-by-symbol detection using a finite sequence observation space has been the subject of renewed research interest. The Bayesian transverse equalizer (BTE) and Bayesian decision feedback equalizer (BDFE) are two common Bayesian detectors. It is often difficult to evaluate the bit-error rate (BER) performance of these Bayesian detectors since the BER cannot be analytically evaluated and the high complexity of these detectors makes simulation techniques computationally prohibitive, especially at low BERs. We propose a framework to evaluate the BER for the BTE and a lower bound on the BER for the BDFE. This framework is based on finding an approximation of the conditional error probability for each of the noiseless channel states in the observation space. The optimal Bayesian decision boundary is approximated by a set of hyperplanes, and each hyperplane is rotated some minimal angle to make them mutually orthogonal/parallel. The conditional probability of error can be readily evaluated on the topology of orthogonal/parallel rotated hyperplanes. Our BER evaluation is accurate and does not require simulations. A reduced complexity approach to evaluate the BER is also developed.
Figure&ndash;Ground Segregation in a Recurrent Network Architecture
Authors: Pieter R. Roelfsema, Victor A. F. Lamme, Henk Spekreijse, Holger Bosch
Venue: Journal of Cognitive Neuroscience (2002)

Here we propose a model of how the visual brain segregates textured scenes into figures and background. During texture segregation, locations where the properties of texture elements change abruptly are assigned to boundaries, whereas image regions that are relatively homogeneous are grouped together. Boundary detection and grouping of image regions require different connection schemes, which are accommodated in a single network architecture by implementing them in different layers. As a result, all units carry signals related to boundary detection as well as grouping of image regions, in accordance with cortical physiology. Boundaries yield an early enhancement of network responses, but at a later point, an entire figural region is grouped together, because units that respond to it are labeled with enhanced activity. The model predicts which image regions are preferentially perceived as figure or as background and reproduces the spatio-temporal profile of neuronal activity in the visual cortex during texture segregation in intact animals, as well as in animals with cortical lesions.
Some basic properties of multiple Hamiltonian covers
Authors: Hans L. Fetter
Venue: Discrete Applied Mathematics (2006)

The aim of this work is to introduce the concept of a multiple Hamiltonian cover (MHC). For the most part, attention is restricted to the class of cubic three-connected planar graphs. For those graphs having an MHC composed of three Hamiltonian cycles we are able to derive a Grinberg type result. On the other hand, for those graphs having an MHC consisting of six Hamiltonian cycles we find it convenient to impose the additional notion of balance, which then allows us to deduce some interesting consequences. We conclude with a problem from three-dimensional geometry. MHC's play a significant role in its solution.
Generalised Weighted Relevance Aggregation Operators for Hierarchical Fuzzy Signatures
Authors: B. S. U. Mendis, T. D. Gedeon, J. Botzheim, L. T. Koczy
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)

Hierarchical Fuzzy Signatures are generalizations of the Vector Valued Fuzzy Set concept introduced in the 1970s. A crucial question in the Fuzzy Signature context is what kinds of aggregations are applicable for combining data with partly different substructures. Our earlier work introduced the Weighted Relevance Aggregation method to enhance the accuracy of the final results of calculations based on Hierarchical Fuzzy Signature Structures. In this paper, we further generalise the weights and the aggregation into a new operator called Weighted Relevance Aggregation Operator (WRAO). WRAO enhances the adaptability of the fuzzy signature model to different applications and simplifies the learning of fuzzy signature models from data. We also show the methodology of learning these aggregation operators from data.
Data farming coevolutionary dynamics in RePast
Authors: Brian F. Tivnan
Venue: Proceedings of the 36th conference on Winter simulation (2004)

This paper describes the application of data farming techniques (Brandstein and Horne 1998) to explore various aspects of coevolutionary dynamics (McKelvey 2002) in organization science. Data farming is an iterative process using high-performance computing to execute and vary agent-based models, collect and explore statistical results, and integrate these results for the purposes of growing more data by virtue of generative analysis. The tool of choice for creating these agent-based models is the University of Chicago's Social Science Research Computing's (2004) REcursive Porous Agent Simulation Toolkit (Re-Past). The paper concludes with a brief description of Tivnan's (2004) Coevolutionary model of Boundary-spanning Agents and Strategic Networks (C-BASN), an extension of Hazy and Tivnan's (2004) Model of Organization, Structural Emergence, and Sustainability (MOSES).
Automated Derivation of Complex System Constraints from User Requirements
Authors: Kim Muery, Mark Foshee, Angela Marsh
Venue: Proceedings of the 2nd IEEE International Conference on Space Mission Challenges for Information Technology (2006)

International Space Station (ISS) payload developers submit their payload science requirements for the development of on-board execution timelines. The ISS systems required to execute the payload science operations must be represented as constraints for the execution timeline. Payload developers use a software application, User Requirements Collection (URC), to submit their requirements by selecting a simplified representation of ISS system constraints. To fully represent the complex ISS systems, the constraints require a level of detail that is beyond the insight of the payload developer. To provide the complex representation of the ISS system constraints, HOSC operations personnel, specifically the Payload Activity Requirements Coordinators (PARC), manually translate the payload developers' simplified constraints into detailed ISS system constraints used for scheduling the payload activities in the Consolidated Planning System (CPS). This paper describes the implementation for a software application, User Requirements Integration (URI), developed to automate the manual ISS constraint translation process.
Structured formal development in Isabelle
Authors: Maksym Bortin, Einar Broch Johnsen, Christoph Lüth
Venue: Nordic Journal of Computing (2006)

General purpose theorem provers provide advanced facilities for proving properties about specifications, and may therefore be a valuable tool in formal program development. However, these provers generally lack many of the useful structuring mechanisms found in functional programming or specification languages. This paper presents a constructive approach to adding theory morphisms and parametrisation to theorem provers, while preserving the proof support and consistency of the prover. The approach is implemented in Isabelle and illustrated by examples of an algorithm design rule and of the modular development of computational effects for imperative language features based on monads.
Toward a Code Search Engine Based on the State-of-Art and Practice
Authors: Vinicius C. Garcia, Eduardo S. de Almeida, Liana B. Lisboa, Alexandre C. Martins, Silvio R. L. Meira, Daniel Lucredio, Renata P. de M. Fortes
Venue: Proceedings of the XIII Asia Pacific Software Engineering Conference (2006)

Software engineering and reuse-oriented tools have been studied along the last years, aiming to provide help in the software development. With the importance of reuse growing significantly, effective software reuse tools and environments started to be needed. This paper presents and discusses some works that comprise many issues related to source code search tools, covered by university and industry since 90's until today. In the end of the paper, a set of requirements is presented, integrating the features that can be found in most works of the area, serving as a basis for future work toward an effective source code search tool.
The MAPa language of agent dialogues
Authors: María Adela Grando, Christopher D. Walton
Venue: Proceedings of the fifth international joint conference on Autonomous agents and multiagent systems (2006)

In this paper we present the MAPa language for expressing coordination and communication between agents in multi-agent systems. This is accomplished by defining patterns of dialogues between groups of agents, expressed as protocols. Our protocols are flexible and directly executable. Furthermore, our language allow us to specify the connection between communication and knowledge management in a way that is independent of the specific reasoning techniques used.
Simulation analysis of appointment scheduling in an outpatient department of internal medicine
Authors: Athula Wijewickrama, Soemon Takakuwa
Venue: Proceedings of the 37th conference on Winter simulation (2005)

Long waiting times for treatment in the outpatient department of internal medicine, followed by short consultations has long been a complaint of patients. This issue is becoming increasingly important in Japan with the progressively aging society. In this context, a discrete event simulation model to examine various appointment schedules in a mixed-patient type environment in an outpatient department of a general hospital was developed. A special purpose data generator was designed to validate the model and to conduct experiments in bottleneck situations at consultation rooms in the existing system. Some efficient appointment schedules (ASs) were identified, which drastically reduced patient waiting time while keeping doctor idle time as low as possible without adding extra resources. The sensitivity of performance was examined under three realistic environmental factors: no show, variance of consultation time, and variation of walk-ins.
Algorithms for storytelling
Authors: Deept Kumar, Naren Ramakrishnan, Richard F. Helm, Malcolm Potts
Venue: Proceedings of the 12th ACM SIGKDD international conference on Knowledge discovery and data mining (2006)

We formulate a new data mining problem called it storytelling as a generalization of redescription mining. In traditional redescription mining, we are given a set of objects and a collection of subsets defined over these objects. The goal is to view the set system as a vocabulary and identify two expressions in this vocabulary that induce the same set of objects. Storytelling, on the other hand, aims to explicitly relate object sets that are disjoint (and hence, maximally dissimilar) by finding a chain of (approximate) redescriptions between the sets. This problem finds applications in bioinformatics, for instance, where the biologist is trying to relate a set of genes expressed in one experiment to another set, implicated in a different pathway. We outline an efficient storytelling implementation that embeds the CART wheels redescription mining algorithm in an A* search procedure, using the former to supply next move operators on search branches to the latter. This approach is practical and effective for mining large datasets and, at the same time, exploits the structure of partitions imposed by the given vocabulary. Three application case studies are presented: a study of word overlaps in large English dictionaries, exploring connections between genesets in a bioinformatics dataset, and relating publications in the PubMed index of abstracts.
An Optimum ORA BIST for Multiple Fault FPGA Look-Up Table Testing
Authors: Armin Alaghi, Mahnaz Sadoughi Yarandi, Zainalabedin Navabi
Venue: Proceedings of the 15th Asian Test Symposium (2006)

This paper presents a BIST architecture for FPGA Look-Up Table testing using a minimum number of logic elements for its ORA. The propagation of faults in the TPGs and CUTs is formulated so that the ORA can detect multiple faults by monitoring a single signal. At the cost of using more cells for the ORA, the granularity of error detection can be reduced to as low as one fault per five LUTs. The increase in the ORA overhead, and thus the untested FPGA areas, can be compensated by more configurations. We will show that 100% test coverage and a maximum granularity can be achieved simultaneously by a reasonable number of FPGA configurations.
Combining functional and linkage disequilibrium information in the selection of tag SNPs
Authors: P. C. Sham, S. I. Ao, J. S. H. Kwan, P. Kao, F. Cheung, P. Y. Fong, M. K. Ng
Venue: Bioinformatics (2007)

Summary: We have developed an online program, WCLUSTAG, for tag SNP selection that allows the user to specify variable tagging thresholds for different SNPs. Tag SNPs are selected such that a SNP with user-specified tagging threshold C will have a minimum R2 of C with at least one tag SNP. This flexible feature is useful for researchers who wish to prioritize genomic regions or SNPs in an association study. Availability: The online WCLUSTAG program is available at http://bioinfo.hku.hk/wclustag/ Contact: mng@math.hkbu.edu.hk
Simulation-optimization for transportation in a unified automated material handling systems
Authors: Jairo Rafael Montoya Torres, Stéphane Dauzere-Peres, Hélène Marian, Leon Vermarien
Venue: Proceedings of the 37th conference on Winter simulation (2005)

This paper focuses on the analysis of transport strategies in Automated Material Handling Systems (AMHS) for the semiconductor industry. A difference against previous work is that our approach takes into account the unified nature of inter-bay and intra-bay load transport operations. In a unified AMHS, vehicles can travel along the whole network path to deliver loads directly from one machine to another without passing by intermediate storage. In order to optimally satisfy transport requests during the production horizon, intelligent strategies have to be implemented. The problem is addressed by means of a hybrid simulation-optimization approach. A detailed simulation model of the semiconductor factory is built in order to analyze factory dynamics. Mathematical programming is used to determine the optimal value of the parameters of the simulation model. The detailed simulation model carried out for this research work showed some interesting and unpredictable evidences.
Mitigating the FloodingWaves Problem in Energy-Efficient Routing for MANETs
Authors: Sameh Gobriel, Daniel Mosse, Rami Melhem
Venue: Proceedings of the 26th IEEE International Conference on Distributed Computing Systems (2006)

In wireless mobile adhoc networks (MANETs) channel and energy capacities are scarce resources, a lot of energy-efficient routing protocols for MANETs have been previously proposed to take into consideration the nodes' residual energies when establishing routes between source-destination pairs. In this paper we are not trying to introduce a new routing algorithm to be added to the already proposed stack of energy-efficient protocols, but rather, we identify a problem in cost-based energy-efficient routing for MANETs, we call this problem "Flooding Waves". We show that the "Flooding Waves" is a serious problem in dense networks, to the extent that the excessive energy overhead consumed in these waves can outweigh the gain achieved by energy-efficient path selection. We propose the "Delayed-Forwarding" as a solution for this problem. We provide both a simulation analysis and a simple theoretical framework to validate and support this solution.
PsyGrid: Applying e-Science to Epidemiology
Authors: John Ainsworth, Robert Harper, Ismael Juma, Iain Buchan
Venue: Proceedings of the 19th IEEE Symposium on Computer-Based Medical Systems (2006)

The process of hypothesis-driven epidemiological research has three phases - the establishment and characterisation of a large, representative cohort from a geographically distributed population; the integration of the cohort data with other data sources to provide additional characterisation; the formulation of a hypothesis and generation of the corresponding predictions. Grid-computing technologies make possible secure, distributed collaboration, and the ability to share data sources, computational resources and storage resources across administrative boundaries. PsyGrid is an e-Science project established to apply grid-computing technologies to each of the three phases, with the aim of eliminating the obstacles that hinder epidemiological research. We describe a system for distributed cohort characterisation, and the first application to the study of First Episode Psychosis.
Service Quality Design Via Fuzzy Approach
Authors: Jung-Fung Chen
Venue: Proceedings of the First International Conference on Innovative Computing, Information and Control - Volume 2 (2006)

This paper presents a fuzzy optimization model (FOM) based on the fuzzy set theory (FST), through which the decision-makers are able to determine what type of quality characteristic or service standard should be provided to customers of different needs at the same time, in order to maximize general customer satisfaction (CS). In this paper, the trapezoidal fuzzy number (TFN) of the FST represents the levels of CS, while the linear programming (LP) constructs the FOM; an example of services provided to three customers in a restaurant is used to demonstrate the practicability of FOM. The model presented in this study is quite practical and can be applied broadly to all businesses.