ppxscal/embedding_network huggingface dataset:
On-line assessment of statistical learning by event-related potentials
Authors: Dilshat Abla, Kentaro Katahira, Kazuo Okanoya
Venue: Journal of Cognitive Neuroscience (2008)

We investigated the neural processes involved in on-line statistical learning and word segmentation. Auditory event-related potentials (ERPs) were recorded while participants were exposed to continuous, nonlinguistic auditory sequences, the elements of which were organized into “tritone words” that were sequenced in random order, with no silent spaces between them. After listening to three 6.6-min sessions of sequences, the participants performed a behavioral choice test, in which they were instructed to indicate the most familiar tone sequence in each test trial by pressing buttons. The participants were divided into three groups (high, middle, and low learners) based on their behavioral performance. The overall mean performance was 74.4%, indicating that the tone sequence was segmented and that the participants learned the tone words statistically. Grand-averaged ERPs showed that word onset (initial tone) elicited the largest N100 and N400 in the early learning session of high learners, but in middle learners, the word-onset effect was elicited in a later session, and there was no effect in low learners. The N400 amplitudes significantly differed between the three learning sessions in the high-and middle-learner groups. The results suggest that the N400 effect indicates not only on-line word segmentation but also the degree of statistical learning. This study provides insight into the neural mechanisms underlying on-line statistical learning processes.
A new interface for video browsing on PDAs
Authors: Wolfgang Hürst, Georg Götz, Martina Welte
Venue: Proceedings of the 9th international conference on Human computer interaction with mobile devices and services (2007)

We present an interface for interactive video browsing on pen-based handheld devices. Our solution enables users to navigate through a video along the timeline at different granularity levels. In addition, one can skim a file's content by continuous modification of replay speed. Both interaction concepts are smoothly integrated into a single interface that takes full advantage of the limited screen space being available.
Sampling Error Estimation in High-Speed Sampling Systems Introduced by the Presence of Phase Noise in the Sampling Clock
Authors: Salam D. Marougi
Venue: Proceedings of the 9th international symposium on Quality Electronic Design (2008)

The presence of phase noise in the sampling clock of fast Analog-to-Digital converters introduces time jitter into the sampling instants of the Analog-to-Digital converter. In this paper, an analysis has been performed to quantify the impact of phase perturbation in the sampling clock on the signal-to-noise ratio of the digitized waveform. Close form formulae have been obtained for the signal-to-jitter noise (S/Njit) ratio when the phase perturbation is random as well as when it is dominated by a periodic and deterministic component. The result obtained is then used to predict the jitter noise generated by a sampling clock with typical phase noise performance. The results obtained will help identify the impact of the various sampling and phase noise parameters on the resulting S/Njit ratio.
An adaptively accelerated Lucy-Richardson method for image deblurring
Authors: Manoj Kumar Singh, Uma Shanker Tiwary, Young-Hoon Kim
Venue: EURASIP Journal on Advances in Signal Processing (2008)

We present an adaptively accelerated Lucy-Richardson (AALR) method for the restoration of an image from its blurred and noisy version. The conventional Lucy-Richardson (LR) method is nonlinear and therefore its convergence is very slow. We present a novel method to accelerate the existing LR method by using an exponent on the correction ratio of LR. This exponent is computed adaptively in each iteration, using first-order derivatives of the deblurred image from previous two iterations. Upon using this exponent, the AALR improves speed at the first stages and ensures stability at later stages of iteration. An expression for the estimation of the acceleration step size in AALR method is derived. The superresolution and noise amplification characteristics of the proposed method are investigated analytically. Our proposed AALR method shows better results in terms of low root mean square error (RMSE) and higher signal-to-noise ratio (SNR), in approximately 43% fewer iterations than those required for LR method. Moreover, AALR method followed by wavelet-domain denoising yields a better result than the recently published state-of-the-art methods.
Motion synthesis with decoupled parameterization
Authors: Dongwook Ha, JungHyun Han
Venue: The Visual Computer: International Journal of Computer Graphics (2008)

In real-time animation systems, motion interpolation techniques are widely used for their controllability and efficiency. The techniques sample the parameter space using example motions, and interpolate them to compute the blend weights corresponding to the given parameters. A main problem of the techniques is that, as the dimension n of the parameter space increases, the number of required example motions increases exponentially, i.e. O(c n ). To resolve the problem, this paper proposes to use two decoupled parameter spaces for controlling the upper body and the lower body separately. At each frame time, a parameterized motion space produces a source frame, and the target frame is synthesized by splicing the upper body of one source frame with the lower body of the other. In order to have the two source frames correlated with each other, a time-warping scheme has been developed. Furthermore, in order to handle the dynamic properties of the parameter samples of the upper body, we have developed an approximation technique for quickly determining the sample positions in its parameter space. This decoupled parameterization method alleviates the complexity problem, e.g. from O(c 6) to O(c 3), while providing the users with the capability of convenient control over the character.
Authorization recycling in RBAC systems
Authors: Qiang Wei, Jason Crampton, Konstantin Beznosov, Matei Ripeanu
Venue: Proceedings of the 13th ACM symposium on Access control models and technologies (2008)

As distributed applications increase in size and complexity, traditional authorization mechanisms based on a single policy decision point are increasingly fragile because this decision point represents a single point of failure and a performance bottleneck. Authorization recycling is one technique that has been used to address these challenges. This paper introduces and evaluates the mechanisms for authorization recycling in RBAC enterprise systems. The algorithms that support these mechanisms allow precise and approximate authorization decisions to be made, thereby masking possible failures of the policy decision point and reducing its load. We evaluate these algorithms analytically and using a prototype implementation. Our evaluation results demonstrate that authorization recycling can improve the performance of distributed access control mechanisms.
Dynamic packet fragmentation for wireless channels with failures
Authors: Predrag R. Jelenković, Jian Tan
Venue: Proceedings of the 9th ACM international symposium on Mobile ad hoc networking and computing (2008)

It was shown recently [7-9], under quite general conditions, that retransmission-based protocols may result in power-law delays and possibly zero throughput even if the distribution of packets (data units) is very concentrated, e.g., exponential or Gaussian. This phenomenon occurs irrespective of whether the cause of retransmissions is due to channel failures in the data link layer [7] or collisions in ALOHA-type protocols in the MAC layer [9]. These theoretical findings are in agreement with empirical measurements in [18], showing that the utilization of the 802.11 protocol is only 40%, basically due to retransmissions. In order to alleviate this problem, we propose a new dynamic packet fragmentation algorithm that can adaptively match channel failure characteristics. This algorithm is based on the mathematical insights developed in [7, 8]. As a first order approximation to the channel dynamics, we assume that the channel is either available for a period of time or unavailable. Then, our fragmentation algorithm divides the original packets into smaller ones whose size is bounded by the kth largest value among the last k+m channel availability periods. We also discuss mechanisms for aggregating smaller packets into larger ones, which, in combination with fragmentation, can further improve the performance. Under the renewal assumptions on the channel dynamics, we prove that our fragmentation method results in k additional moments for the total transmission time until all the fragments are successfully transmitted, i.e., the transmission time has a much more concentrated distribution and, in particular, the channel will always have a positive throughput. In addition, we argue that by tuning the parameter m, the number of introduced new packets can be kept reasonably small as well. Furthermore, we demonstrate through simulations that the superior performance of our fragmentation algorithm extends beyond the renewal assumptions used in the analysis to time varying and/or correlated channels. For practical implementation of the algorithm, we also discuss approaches to measuring the channel availability periods, especially in situations when the channel dynamics may not be directly observable. It is worth mentioning that our algorithm can be used for designing efficient checkpointing schemes in other systems that are prone to failures, e.g., distributed computing systems.
Filtering segmentation cuts for digit string recognition
Authors: E. Vellasques, L. S. Oliveira, A. S. Britto,  Jr., A. L. Koerich, R. Sabourin
Venue: Pattern Recognition (2008)

In this paper we propose a method to evaluate segmentation cuts for handwritten touching digits. The idea of this method is to work as a filter in segmentation-based recognition system. This kind of system usually rely on over-segmentation methods, where several segmentation hypotheses are created for each touching group of digits and then assessed by a general-purpose classifier. The novelty of the proposed methodology lies in the fact that unnecessary segmentation cuts can be identified without any attempt of classification by a general-purpose classifier, reducing the number of paths in a segmentation graph, what can consequently lead to a reduction in computational cost. An cost-based approach using ROC (receiver operating characteristics) was deployed to optimize the filter. Experimental results show that the filter can eliminate up to 83% of the unnecessary segmentation hypothesis and increase the overall performance of the system.
Reorganizing compressed text
Authors: Nieves R. Brisaboa, Antonio Fariña, Susana Ladra, Gonzalo Navarro
Venue: Proceedings of the 31st annual international ACM SIGIR conference on Research and development in information retrieval (2008)

Recent research has demonstrated beyond doubts the benefits of compressing natural language texts using word-based statistical semistatic compression. Not only it achieves extremely competitive compression rates, but also direct search on the compressed text can be carried out faster than on the original text; indexing based on inverted lists benefits from compression as well. Such compression methods assign a variable-length codeword to each different text word. Some coding methods (Plain Huffman and Restricted Prefix Byte Codes) do not clearly mark codeword boundaries, and hence cannot be accessed at random positions nor searched with the fastest text search algorithms. Other coding methods (Tagged Huffman, End-Tagged Dense Code, or (s, c)-Dense Code) do mark codeword boundaries, achieving a self-synchronization property that enables fast search and random access, in exchange for some loss in compression effectiveness. In this paper, we show that by just performing a simple reordering of the target symbols in the compressed text (more precisely, reorganizing the bytes into a wavelet-treelike shape) and using little additional space, searching capabilities are greatly improved without a drastic impact in compression and decompression times. With this approach, all the codes achieve synchronism and can be searched fast and accessed at arbitrary points. Moreover, the reordered compressed text becomes an implicitly indexed representation of the text, which can be searched for words in time independent of the text length. That is, we achieve not only fast sequential search time, but indexed search time, for almost no extra space cost. We experiment with three well-known word-based compression techniques with different characteristics (Plain Huffman, End-Tagged Dense Code and Restricted Prefix Byte Codes), and show the searching capabilities achieved by reordering the compressed representation on several corpora. We show that the reordered versions are not only much more efficient than their classical counterparts, but also more efficient than explicit inverted indexes built on the collection, when using the same amount of space.
DNA solution based on sequence alignment to the Minimum Spanning Tree problem
Authors: Aili Han, Daming Zhu, Jingchang Pan
Venue: International Journal of Bioinformatics Research and Applications (2008)

Sequence alignment reveals the relations between the characters in different sequences, and there are the reverse complement relations between the characters in DNA double strand. We introduce sequence alignment to the field of DNA computing, propose the definitions of complement alignment and reverse complement alignment, give a method of computing the scores of complement alignment and reverse complement alignment, and devise a DNA encoding method and the corresponding DNA algorithm for the Minimum Spanning Tree (MST) problem by means of reverse complement alignments. Our work enriches the theory of DNA computing and extends the range of DNA computing to solve optimisation problems.
Weblogging: A study of social computing and its impact on organizations
Authors: Rachael Kwai Fun IP, Christian Wagner
Venue: Decision Support Systems (2008)

This article reviews weblogs and their role as a social networking device for young people and its probable evolution to the organizational computing medium. The motivation of young webloggers, based on an analysis of 33 interviews, and the evaluation of the fit between technology features and the needs of these webloggers are reported. Four user types with their unique profiles and technology needs, and a needs-technology fit model, are described. The findings support the conjecture that organizational computing will (or should) take advantage of employees' social computing expertise and acceptance and to further capture the attention of customers.
Universal DSP based system for communication with AMSAT experimental satellites
Authors: Jan Šebesta, Jiří Šebesta
Venue: Proceedings of the 4th WSEAS International Conference on Applied Informatics and Communications (2004)

The aim of the work is to realize multi-channel universal DSP based communication system suited for ground stations for monitoring experimental satellites launched by AMSAT. The designed system includes four channel terminal node controller with processor AM186CC to handle radio communication protocol, which is commonly AX.25 protocol. System also contains onboard DSP modem with ADSP2189 and digital frequency converters, which enable high universality in modulation selection and sufficient performance in narrowband satellite communication, especially in Doppler shift elimination process. Developed software tools and codekits in assembler and C allow maximally fast and effective algorithms to be developed. New digital modulation techniques for GMSK and similar modulations has been invented and implemented in the system. Next step is aimed on new demodulation algorithms and synchronization techniques.
Where do we go from here? An assessment of navigation performance using a compass versus a GPS unit
Authors: Mark S. Young, Neville A. Stanton, Guy H. Walker, Daniel P. Jenkins, Wes Smart
Venue: Cognition, Technology and Work (2008)

The Global Positioning System (GPS) looks set to replace the traditional map and compass for navigation tasks in military and civil domains. However, we may ask whether GPS has a real performance advantage over traditional methods. We present an exploratory study using a waypoint-plotting task to compare the standard magnetic compass against a military GPS unit, for both expert and non-expert navigators. Whilst performance times were generally longer in setting up the GPS unit, once navigation was underway the GPS was more efficient than the compass. For medium- to long-term missions, this means that GPS could offer significant performance benefits, although the compass remains superior for shorter missions. Notwithstanding the performance times, significantly more errors, and more serious errors, occurred when using the compass. Overall, then, the GPS offers some clear advantages, especially for non-expert users. Nonetheless, concerns over the development of cognitive maps remain when using GPS technologies.
Concept of Multi-agent Conditional Interplay
Authors: Alexey Botchkaryov, Serhiy Kovela
Venue: Proceedings of the Tenth International Conference on Computer Modeling and Simulation (2008)

A new approach to modeling the collective behaviour in terms of conditional multi-agent interplay is proposed in this paper. Within this approach, we explicitly model the situation where some agents’ action history (past behaviour) conditions subsequent actions of some other agents. Such a viewpoint of the multi-agent behaviour provides for the possibility to create and study useful models of collective behaviour, ultimately gaining a deeper understanding of the basic laws of the conditional interplay. The temporizing game as an example of modeling the collective behaviour within the sample coordination space, the cyberCromlech, demonstrates the approach.
Analytical design of optimal controllers under permanent stochastic disturbances as applied to the design of vibration isolation systems
Authors: A. D. Mizhidon
Venue: Automation and Remote Control (2008)

An approach to the design of vibroprotection systems for objects subjected to stochastic disturbances was developed on the basis of a procedure for analytical design of the optimal controller. For that, this procedure was generalized to the case of permanently acting stationary stochastic disturbances. When solving the problem of designing the vibration isolation system, the optimizing functional was constructed so that minimization provided reduction in the dynamic actions on the object with the observance of the overall disturbances. Technical feasibility of the vibration isolation system designed using the elastodamping suspensions and dampers with transformation of motion was demonstrated.
Using peer-to-peer technology for knowledge sharing in communities of practices
Authors: Chen-Ya Wang, Hsin-Yi Yang, Seng-cho T. Chou
Venue: Decision Support Systems (2008)

Communities of Practices (CoPs) are informal structures within organizations that bind people together through informal relationships and the sharing of expertise and experience. As such, they are effective tools for the creation and sharing of organizational knowledge, and an increasing number of organizations are adopting them as part of their knowledge management strategies. In this paper, we examine the knowledge sharing characteristics and roles of CoPs and develop a peer-to-peer knowledge sharing architecture that matches the behavioral characteristics of the members of the CoPs. We also propose a peer-to-peer knowledge sharing tool called KTella that enables a community's members to voluntarily share and retrieve knowledge more effectively.
A kappa projection algorithm (KPA) for programming to femtoampere currents in standard CMOS floating-gate elements
Authors: Paul D. Smith, David Graham, Paul Hasler
Venue: Analog Integrated Circuits and Signal Processing (2008)

We present an algorithm that enables programming of standard CMOS floating-gate devices into ultra-low current levels. This paper looks at the limitations of conventional programming schemes for these devices, as well as new methods to achieve ultra-low current levels, reliably, in these devices. Currents range from 1 µA down to 100 fA. We present measured results programming an array of bandpass filters using floating-gate transistors using the Kappa Projection Algorithm (KPA) from 10 Hz to 48 kHz. We program out device offsets and mismatches to result in very precise device behavior within the circuit elements. Experimental data is presented from circuits fabricated on a 0.5 µm nwell CMOS process available through MOSIS.
QoS-supported on-chip communication for multi-processors
Authors: Mohammad Abdullah Al Faruque, Jörg Henkel
Venue: International Journal of Parallel Programming (2008)

We present a Quality of Service (QoS)-supported on-chip communication that increases the shared communication resources for multi-processor systems on chip. Time-critical embedded systems require tight guaranteed services in terms of throughput, latency etc. in order to comply to hard real-time constraints. Typically, guaranteed-service schemes require dedicated/reserved resources (i.e. links) for communication and thus suffer from low resource utilization. So improving the bandwidth utilization by using the unused bandwidth among the other competing transactions in a fair fashion is an important issue. To the best of our knowledge, we are presenting the first approach for on-chip communication that provides a high resource utilization under a transaction-specific, flexible communication scheme. It provides tight time-related guarantees through our bounded arbitration scheme considering the lower and the upper bounds for each type of transactions. We demonstrate its advantages by means of a complete MPEG4 video decoder case study analysis and achieve under certain constraints a bandwidth utilization of up to 100% and 97% on average with a guaranteed 100% bandwidth. Thus, we provide an on-chip communication scheme that provides high bandwidth uti lization while providing tight guarantee.