ppxscal/embedding_network huggingface dataset:
2005 Special issue: Spatial view cells in the hippocampus, and their idiothetic update based on place and head direction
Authors: Edmund T. Rolls, Simon M. Stringer
Venue: Neural Networks (2005)

Single neuron recording studies have demonstrated the existence of spatial view neurons which encode information about the spatial location at which a primate is looking in the environment. These neurons are able to maintain their firing even in the absence of visual input. The standard neuronal network approach to model networks with memory that represent continuous spaces is that of continuous attractor neural networks. Stringer, Rolls and Trappenberg (2005) have recently shown how idiothetic (self-motion) inputs could update the activity packet of neuronal firing within a two-dimensional continuous attractor neural network of spatial view cells. However, this earlier study examined only the simplified situation in which the agent could rotate on the spot or move its eyes. In this paper we show how spatial view cells could be driven by head direction and place cells, themselves idiothetically updated. The head direction and place neurons are remapped by a competitive network with expansion recoding which self-organises so that different neurons represent different combinations of head direction and the place where the agent is located. The combination cells are then mapped by pattern association involving long-term synaptic potentiation but also long-term homosynaptic depression to spatial view cells, which during training are driven by the spatial view. After training, the spatial view cells are updated in the dark by the idiothetically driven head direction and place cells.
Numerical calculation of electric fields with charge densities expressed using spline functions
Authors: Yohei Miyazaki, Keiko Yukawa, Kazutaka Kitamori
Venue: Proceedings of the 37th conference on Winter simulation (2005)

In the simulation of plasma processes, minimizing the error associated with the electric field calculation in the vicinity of the sheath is an important consideration. The sheath length scale when compared to the plasma size and fact that the electric fields must be solved for self-consistently with equations describing the plasma chemistry make the electric field solution particularly expensive. We describe an electric field simulation with high speed and good accuracy enabled by the description of the density of charged by spline functions. In our method, Legendre Polynomial Weighted Sampling (LPWS) is used to determine charged particle density and velocity distributions. The LPWS method has been developed for Monte Carlo simulations as a means of obtaining more detailed distributions from smaller (or coarser) sample sizes. The coefficient of the spline function is obtained directly from LPWS rather than through macroparameters extracted from the distributions.
Keyphrase Extraction Using Semantic Networks Structure Analysis
Authors: Chong Huang, Yonghong Tian, Zhi Zhou, Charles X. Ling, Tiejun Huang
Venue: Proceedings of the Sixth International Conference on Data Mining (2006)

Keyphrases play a key role in text indexing, summarization and categorization. However, most of the existing keyphrase extraction approaches require human-labeled training sets. In this paper, we propose an automatic keyphrase extraction algorithm, which can be used in both supervised and unsupervised tasks. This algorithm treats each document as a semantic network. Structural dynamics of the network are used to extract keyphrases (key nodes) unsupervised. Experiments demonstrate the proposed algorithm averagely improves 50% in effectiveness and 30% in efficiency in unsupervised tasks and performs comparatively with supervised extractors. Moreover, by applying this algorithm to supervised tasks, we develop a classifier with an overall accuracy up to 80%.
Using bandwidth-space partitioning to improve cell coverage and near-far unfair access problem in a noise-limited CDMA cellular network
Authors: Shih-Tsung Yang, Anthony Ephremides
Venue: Wireless Networks (2005)

This paper concerns CDMA cellular networks equipped with conventional matched filter receivers. For this type of cellular networks, two problems exist. One is the inverse relationship between the coverage and capacity, and the other one is the near-far unfair access problem. To resolve these two problems, a bandwidth-space partitioning technique is adopted. Several admission control schemes based on the bandwidth-space partitioning technique are proposed, and their performances are evaluated based on the simulation.
Effective blind separation of skewed sources
Authors: Rubén Martín-Clemente, Susana Hornillo-Mellado
Venue: Signal Processing (2006)

This article proposes a new algorithm for estimating skewed real signals in blind source separation. It is based on the eigendecomposition of a third-order statistics matrix. This matrix is updated iteratively by the algorithm in order to increase the robustness of the estimated source signals against numerical errors and perturbations. Simulations show the effectiveness of the approach.
Adaptive hypermedia as a means for learning programming
Authors: Petr Šaloun, Zdenek Velart
Venue: Workshop proceedings of the sixth international conference on Web engineering (2006)

The adaptive hypermedia system AHA! was used as a tool to increase the quality of education, to ensure the course of programming in C++ and for testing of students. We incorporated into the evaluation tests the idea of negative points per incorrect answer, which is described. Knowledge of basics, rules and semantics of the language, and also training of programming skills is needed for learning the programming language. This paper describes the approach which we used to teach in the context of the course of programming in C++ in the winter semester 2005/2006.The utilization of the outcome of statistics and data mining evaluations of the data gathered in the course -- access to concepts, evaluation of the test in the meaning of correct and incorrect answers -- is shown. The results will be used as a feedback in the next run of the course, or as ideas for future extensions of adaptive hypermedia-based education.
Improving Nearest Neighbor Classifier Using Tabu Search and Ensemble Distance Metrics
Authors: Muhammad Atif Tahir, James Smith
Venue: Proceedings of the Sixth International Conference on Data Mining (2006)

The nearest-neighbor (NN) classifier has long been used in pattern recognition, exploratory data analysis, and data mining problems. A vital consideration in obtaining good results with this technique is the choice of distance function, and correspondingly which features to consider when computing distances between samples. In this paper, a new ensemble technique is proposed to improve the performance of NN classifier. The proposed approach combines multiple NN classifiers, where each classifier uses a different distance function and potentially a different set of features (feature vector). These feature vectors are determined for each distance metric using Simple Voting Scheme incorporated in Tabu Search (TS). The proposed ensemble classifier with different distance metrics and different feature vectors (TS-DF/NN) is evaluated using various benchmark data sets from UCI Machine Learning Repository. Results have indicated a significant increase in the performance when compared with various well-known classifiers. Furthermore, the proposed ensemble method is also compared with ensemble classifier using different distance metrics but with same feature vector (with or without Feature Selection (FS)).
Emotional and Temporal Aspects of Situation Model Processing during Text Comprehension: An Event-Related fMRI Study
Authors: Evelyn C. Ferstl, Mike Rinck, D. Yves Von Cramon
Venue: Journal of Cognitive Neuroscience (2005)

Language comprehension in everyday life requires the continuous integration of prior discourse context and general world knowledge with the current utterance or sentence. In the neurolinguistic literature, these so-called situation model building processes have been ascribed to the prefrontal cortex or to the right hemisphere. In this study, we use whole-head event-related fMRI to directly map the neural correlates of narrative comprehension in context. While being scanned using a spin&ndash;echo sequence, 20 participants listened to 32 short stories, half of which contained globally inconsistent information. The inconsistencies concerned either temporal or chronological information or the emotional status of the protagonist. Hearing an inconsistent word elicited activation in the right anterior temporal lobe. The comparison of different information aspects revealed activation in the left precuneus and a bilateral frontoparietal network for chronological information. Emotional information elicited activation in the ventromedial prefrontal cortex and the extended amygdaloid complex. In addition, the integration of inconsistent emotional information engaged the dorsal frontomedial cortex (Brodmann's area 8/9), whereas the integration of inconsistent temporal information required the lateral prefrontal cortex bilaterally. These results indicate that listening to stories can elicit activation reflecting content-specific processes. Furthermore, updating of the situation model is not a unitary process but it also depends on the particular requirements of the text. The right hemisphere contributes to language processing in context, but equally important are the left medial and bilateral prefrontal cortices.
Strongly typed memory areas programming systems-level data structures in a functional language
Authors: Iavor S. Diatchki, Mark P. Jones
Venue: Proceedings of the 2006 ACM SIGPLAN workshop on Haskell (2006)

Modern functional languages offer several attractive features to support development of reliable and secure software. However, in our efforts to use Haskell for systems programming tasks-including device driver and operating system construction-we have also encountered some significant gaps in functionality. As a result, we have been forced, either to code some non-trivial components in more traditional but unsafe languages like C or assembler, or else to adopt aspects of the foreign function interface that compromise on strong typing and type safety.In this paper, we describe how we have filled one of these gaps by extending a Haskell-like language with facilities for working directly with low-level, memory-based data structures. Using this extension, we are able to program a wide range of examples, including hardware interfaces, kernel data structures, and operating system APIs. Our design allows us to address concerns about representation, alignment, and placement (in virtual or physical address spaces) that are critical in some systems applications, but clearly beyond the scope of most existing functional languages.Our approach leverages type system features that are wellknown and widely supported in existing Haskell implementations, including kinds, multiple parameter type classes, functional dependencies, and improvement. One interesting feature is the use of a syntactic abbreviation that makes it easy to define and work with functions at the type level.
Improving Testing Efficiency using Cumulative Test Analysis
Authors: Ian Holden, Dave Dalton
Venue: Proceedings of the Testing: Academic & Industrial Conference on Practice And Research Techniques (2006)

It can be impossible to thoroughly test complex software projects with a large library of tests to be run in many environments and configurations. The Cumulative Test Analysis (CTA) technique described reduces the time to find defects by prioritising and minimising the testing. Tests are chosen to target the product areas having the highest risk of defects. Test effectiveness, test code coverage, product code changes and changes to dependencies are monitored and analysed to prioritise the testing. Test results from build to build are accumulated. Build reports clearly identify areas at risk, test results, and the tests that must be run. Experiences with a prototype tool are discussed and conclusions drawn from the use of CTA show that defects are found sooner, more time is available for writing new tests and the focus of test execution moves towards product quality instead of simply test results.
Profiling Management for Personalised Multimedia Delivery On-Demand within the AXMEDIS Framework
Authors: A. Badii, M. Sailor, R. R. Nair
Venue: Proceedings of the Second International Conference on Automated Production of Cross Media Content for Multi-Channel Distribution (2006)

Media content distribution on-demand becomes more complex when performed on a mass scale involving various channels with distinct and dynamic network characteristics, and, deploying a variety of terminal devices offering a wide range of capabilities. It is practically impossible to create and pre-package various static versions of the same content to match all the varying demand parameters of clients for various contexts. In this paper we present a profiling management approach for dynamically personalised media content delivery on-demand integrated with the AXMEDIS Framework. The client profiles comprise the representation of User, Device, Network and Context of content delivery based on MPEG-21:DIA. Although the most challenging proving ground for this personalised content delivery has been the mobile testbed i.e. the distribution to mobile handsets, the framework described here can be deployed for disribution, by the AXMEDIS PnP module, through other channels e.g. satellite, Internet to a range of client terminals e.g. desktops, kiosks, IPtv and other terrminals whose baseline terminal capabilities can be made availabe by the manufacturers as is normal.
Legal programming
Authors: Brian Subirana, Malcolm Bain
Venue: Communications of the ACM (2006)

Using a process modeling-based approach to address privacy and related legal issues arising in an RFID-based augmented reality shopping situation.
How to Get More Mileage from Randomness Extractors
Authors: Ronen Shaltiel
Venue: Proceedings of the 21st Annual IEEE Conference on Computational Complexity (2006)

Let C be a class of distributions over {0, 1}^n. A deterministic randomness extractor for C is a function E : {0, 1}^n \to {0, 1}^m such that for any X in C the distribution E(X) is statistically close to the uniform distribution. A long line of research deals with explicit constructions of such extractors for various classes C while trying to maximize m. In this paper we give a general transformation that transforms a deterministic extractor E that extracts "few" bits into an extractor E that extracts "almost all the bits present in the source distribution". More precisely, we prove a general theorem saying that if E and C satisfy certain properties, then we can transform E into an extractor E. Our methods build on (and generalize) a technique of Gabizon, Raz and Shaltiel (FOCS 2004) that present such a transformation for the very restricted class C of "oblivious bit-fixing sources". Loosely speaking the high level idea is to find properties of E and C which allow "recycling" the output of E so that it can be "reused" to operate on the source distribution. An obvious obstacle is that the output of E is correlated with the source distribution.
Boosted String Representation and Its Application to Video Surveillance
Authors: Yung-Tai Hsu, Jun-Wei Hsieh
Venue: Proceedings of the 2006 International Conference on Intelligent Information Hiding and Multimedia (2006)

This paper presents a new behavior classification system for analyzing human movements directly from video sequences. First of all, we propose a triangulation-based method to transform each action sequence into a set of symbols. Then, for analyzing the human behavior via those strings representation, we propose a boosted string representation method to extract important string features for accurately analyzing and recognizing different action sequences. The boosted method not only can solve the problem of time warping, but also can reduce the error effects when some postures are wrongly coded into symbols. Since the Adaboost algorithm is proposed for solving two-class problems, we use the error coding concept to modify the Adaboost algorithm such that multiple human action events can be well solved. Then, each action can be well recognized by its correspondence boosted classifier. Experiment results prove that the proposed method is a robust, accurate, and powerful tool for human movement analysis.
Book Reviews: Breaking Security Design Bottlenecks in Payment Technologies
Authors: Godfried Williams
Venue: IEEE Distributed Systems Online (2006)

A review of Payment Technologies for E-Commerce by Weidong Kou, ed.
An advanced VOF algorithm for oil boom design
Authors: J. Fang, K.-F. V. Wong
Venue: International Journal of Modelling and Simulation (2006)

In this paper, an accurate interface convection technique based on the volume-of-fluid (VOF) scheme is presented and the concepts of interface basis and three types of fluxes are introduced to handle two-layer fluid flow in complex geometric situations. The scheme was tested and the results proved to be accurate. We then compared the computational simulation and the laboratory experiment of an innovative boom arrangement. Satisfactory results indicate the potential for using the computational technique developed in this paper to aid in oil boom design as well as in other multilayer immiscible flow applications.
Addressing the Need for Map-Matching Speed: Localizing Globalb Curve-Matching Algorithms
Authors: Carola Wenk, Randall Salas, Dieter Pfoser
Venue: Proceedings of the 18th International Conference on Scientific and Statistical Database Management (2006)

With vehicle tracking data becoming an important sensor data resource for a range of applications related to traffic assessment and prediction, fast and accurate mapmatching algorithms become a necessary means to ultimately utilize this data. This work proposes a fast mapmatching algorithm which exploits tracking data error estimates in a provably correct way and offers a quality guarantee for the computed result trajectory. A new model for the map-matching task is introduced which takes tracking error estimates into account. The proposed Adaptive Clipping algorithm (i) provably solves this map-matching task and (ii) utilizes the weak Fréchet distance to measure similarity between curves. The algorithm uses the error estimates in the trajectory data to reduce the search space (error-aware pruning), while offering the quality guarantee of finding a curve which minimizes the weak Fréchet distance to the vehicle trajectory among all possible curves in the road network. Moreover, this work introduces an outputsensitive variant of an existing weak Fréchet map-matching algorithm, which is also employed in the Adaptive Clipping algorithm. Output-sensitiveness paired with error-aware pruning makes Adaptive Clipping the first map-matching algorithm that provably solves a well-defined map-matching task. An experimental evaluation establishes further that Adaptive Clipping is also in a practical setting a fast algorithm that at the same time produces high-quality matching results.
Comparison of the Basal Ganglia and Cerebellum in Shifting Attention
Authors: Susan M. Ravizza, Richard B. Ivry
Venue: Journal of Cognitive Neuroscience (2001)

The basal ganglia and cerebellum have traditionally been associated with motor performance. Recently, there has been considerable interest regarding the contributions of these subcortical structures to aspects of cognition. In particular, both the basal ganglia and cerebellum have been hypothesized to be involved in the control of attentional set. To date, no neuropsychological studies have directly compared the effects of basal ganglia and cerebellar dysfunction on the same attention shifting tasks. To this end, we employed an alternating attention task that has been used to demonstrate putative attentional control deficits in children with cerebellar pathology, either related to autism or neurological insult. When adult patients with either Parkinson's disease or cerebellar lesions were tested on this task, a similar pattern of deficits was observed for both groups. However, when the motor demands were reduced, cerebellar patients showed a significant improvement on the alternating attention task, whereas the Parkinson patients continued to exhibit an impairment. This dissociation suggests that attentional deficits reported previously as being due to cerebellar dysfunction may be, at least in part, secondary to problems related to coordinating successive responses. In contrast, attention-shifting deficits associated with basal ganglia impairment cannot be explained by recourse to the motor demands of the task.
Extensions of the Kummer evaluation of a finite hypergeometric series
Authors: B. M. Brown, M. S. P. Eastham
Venue: Journal of Computational and Applied Mathematics (2006)

Kummer's evaluation of a finite hypergeometric series F(a, b; c; - 1) (c=b-a+ 1,b=-2m) is extended in two directions to answer questions related to the positivity of Jost functions arising from one-dimensional Schrödinger equations with exponentially decaying potentials.
Implementation of fractional delay waveguide models using allpass filters
Authors: V. Valimaki, M. Karjalainen
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1995. on International Conference - Volume 02 (1995)

This paper discusses a discrete-time modeling technique where the length of time delays can be arbitrarily adjusted. The new system is called a fractional delay waveguide model (FDWM). Formerly, FDWMs have only been implemented with FIR-type fractional delay filters. We show how an FDWM can be implemented using allpass filters. We use low-order allpass filters that are maximally-flat approximations of the ideal delay. The advantages of the allpass approach are computational efficiency and reduced approximation error. The proposed structure can be applied to discrete-time modeling of acoustic tubes, such as the human vocal tract or resonators of musical instruments.
An Improved Automatic MPI Code Generation Algorithm for Distributed Memory Machine
Authors: Xue-rong Gong, Yong-hong Sheng, Lin-sheng Lu, Ping Zhang
Venue: Proceedings of the Seventh International Conference on Parallel and Distributed Computing, Applications and Technologies (2006)

This paper presents an overview of our ongoing project KAP, which aims to build a message-passing parallelizing compiler for distributed-memory machines. In this paper an improved automatic code generation algorithm is discussed. Our algorithm uses the data and computation decomposition, and the reading and writing access functions to create the communication code. We can not only solve the problems which the conventional algorithm can do but also can solve another kind of problem. In such cases: there is no data dependence and the read access is not aligned in the loop nest, or the exact data-flow analysis is not given because of the limitation of the algorithm of LWT, the conventional algorithm can not create communication code correctly while our improved algorithm can resolve this problem. Experiments prove that the novel algorithm can achieve satisfactory effect.
Histogram-Based Perceptual Hashing for Minimally Changing Video Sequences
Authors: Kevin Hamon, Martin Schmucker, Xuebing Zhou
Venue: Proceedings of the Second International Conference on Automated Production of Cross Media Content for Multi-Channel Distribution (2006)

An increasing number of multimedia applications require techniques for efficient and automatic content identification and verification. Here, perceptual hashing technologies apply. Due to the diverseness of video data, algorithms whose design considers the properties of the different video classes are required. Therefore, different approaches exist to extract a perceptual hash. In this article, we propose a histogram-based perceptual hashing algorithm for minimally changing video sequences. The algorithm is described and the performed evaluation shows improvements of the identification performance for minimally changing video content.