ppxscal/embedding_network huggingface dataset:
Psychophysics for perception of (in)determinate art
Authors: Christian Wallraven, Kathrin Kaulard, Cora Kürner, Robert Pepperell, Heinrich H. Bülthoff
Venue: Proceedings of the 4th symposium on Applied perception in graphics and visualization (2007)

The question of how humans perceive art and how the sensory percept is endowed with aesthetics by the human brain has continued to fascinate psychologists and artists alike. It seems, for example, rather easy for us to classify a work of art as either "abstract" or "representational". The artist Robert Pepperell recently has produced a series of paintings that seek to defy this classification: his goal was to convey "indeterminancy" in these paintings - scenes that at first glance look like they contain an object or belong to a certain genre but that upon closer examination escape a definite determination of their contents. Here, we report results from several psychophysical experiments using these artworks as stimuli, which seek to shed light on the perceptual processing of the degree of abstraction in images. More specifically, the task in these experiments was to categorize a briefly shown image as "abstract" or "representational". Stimuli included Pepperell's paintings each of which was paired with a similar representational work of art from several periods and several artistic genres. The results provide insights into the visual processes determining our perception of art and can also function as a "objective" validation for the intentions of the artist.
Speech recognition experiments using multi-span statistical language models
Authors: J. R. Bellegarda
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 02 (1999)

A multi-span framework was proposed to integrate the various constraints, both local and global, that are present in the language. In this approach, local constraints are captured via n-gram language modeling, while global constraints are taken into account through the use of latent semantic analysis. The performance of the resulting multi-span language models, as measured by the perplexity, has been shown to compare favorably with the corresponding n-gram performance. This paper reports on actual speech recognition experiments, and shows that word error rate is also substantially reduced. On a subset of the Wall Street Journal speaker-independent, 20,000-word vocabulary, continuous speech task, the multi-span framework resulted in a reduction in average word error rate of up to 17%.
Independence for partition regular equations
Authors: Imre Leader, Paul A. Russell
Venue: Journal of Combinatorial Theory Series A (2007)

A matrix A is said to be partition regular (PR) over a subset S of the positive integers if whenever S is finitely coloured, there exists a vector x, with all elements in the same colour class in S, which satisfies Ax=0. We also say that S is PR for A. Many of the classical theorems of Ramsey Theory, such as van der Waerden's theorem and Schur's theorem, may naturally be interpreted as statements about partition regularity. Those matrices which are partition regular over the positive integers were completely characterised by Rado in 1933. Given matrices A and B, we say that A Rado-dominates B if any set which is PR for A is also PR for B. One trivial way for this to happen is if every solution to Ax=0 actually contains a solution to By=0. Bergelson, Hindman and Leader conjectured that this is the only way in which one matrix can Rado-dominate another. In this paper, we prove this conjecture for the first interesting case, namely for 1x3 matrices. We also show that, surprisingly, the conjecture is not true in general.
Making Sense of Stories: the development of a new mobile computer game
Authors: Patrick Stacey, Andrew Brown, Joe Nandhakumar
Venue: Proceedings of the 40th Annual Hawaii International Conference on System Sciences (2007)

This paper analyzes the retrospective stories of a four person team responsible for developing a new computer game for mobile phones. Our theorizing is based on an in-depth, two year, case study. The research contribution this paper makes is threefold. First, it outlines and discusses some of the analytical issues at stake in the adoption of a storytelling approach to understanding IS developments. Second, we show how individuals' work stories are tools by which they make sense of organizational events and read meaning into their working lives and relationships with others. Third, we illustrate the roles that individuals' work stories play in bolstering their self-esteem by attributing positive outcomes to the self and negative outcomes to external forces, and in their strategic presentation of the self to others. Finally we outline some implications for managing the mobile game development process.
Adaptive quality of service control in distributed real-time embedded systems
Authors: Chenyang Lu
Venue:  (2006)

An increasing number of distributed real-time embedded systems face the critical challenge of providing Quality of Service (QoS) guarantees in open and unpredictable environments. For example, such systems often need to enforce CPU utilization bounds on multiple processors in order to avoid overload and meet end-to-end deadlines, even when task execution times deviate significantly from their estimated values or change dynamically at run-time. This dissertation presents an adaptive QoS control framework which includes a set of control design methodologies to provide robust QoS assurance for systems at different scales. To demonstrate its effectiveness, we have applied the framework to the end-to-end CPU utilization control problem for a common class of distributed real-time embedded systems with end-to-end tasks. We formulate the utilization control problem as a constrained multi-input-multi-output control model. We then present a centralized control algorithm for small or medium size systems, and a decentralized control algorithm for large-scale systems. Both algorithms are designed systematically based on model predictive control theory to dynamically enforce desired utilizations. We also introduce novel task allocation algorithms to ensure that the system is controllable and feasible for utilization control. Furthermore, we integrate our control algorithms with fault-tolerance mechanisms as an effective way to develop robust middleware systems, which maintain both system reliability and real-time performance even when the system is in face of malicious external resource contentions and permanent processor failures. Both control analysis and extensive experiments demonstrate that our control algorithms and middleware systems can achieve robust utilization guarantees. The control framework has also been successfully applied to other distributed real-time applications such as end-to-end delay control in real-time image transmission. Our results show that adaptive QoS control middleware is a step towards self-managing, self-healing and self-tuning distributed computing platforms.
Analysis and finite element approximation of a Ladyzhenskaya model for viscous flow in streamfunction form
Authors: Faisal A. Fairag
Venue: Journal of Computational and Applied Mathematics (2007)

In this paper we consider a model for the motion of incompressible viscous flows proposed by Ladyzhenskaya. The Ladyzhenskaya model is written in terms of the velocity and pressure while the studied model is written in terms of the streamfunction only. We derived the streamfunction equation of the Ladyzhenskaya model and present a weak formulation and show that this formulation is equivalent to the velocity-pressure formulation. We also present some existence and uniqueness results for the model. Finite element approximation procedures are presented. The discrete problem is proposed to be well posed and stable. Some error estimates are derived. We consider the 2D driven cavity flow problem and provide graphs which illustrate differences between the approximation procedure presented here and the approximation for the streamfunction form of the Navier-Stokes equations. Streamfunction contours are also displayed showing the main features of the flow.
Collaborative Planning With Privacy
Authors: Max Kanovich, Paul Rowe, Andre Scedrov
Venue: Proceedings of the 20th IEEE Computer Security Foundations Symposium (2007)

Collaboration among organizations or individuals is common. While these participants are often unwilling to share all their information with each other, some information sharing is unavoidable when achieving a common goal. The need to share information and the desire to keep it private/ secret are two competing notions which affect the outcome of a collaboration. This paper proposes a formal model of collaboration which addresses privacy/secrecy concerns. We draw on the notion of a plan which originates in the AI literature. We consider transition systems in which actions have pre- and post-conditions of the same size. We show it is PSPACE-complete to decide whether a given such system protects the privacy/secrecy of its participants and whether it contains a plan leading from a given initial state to a desired goal state.
Multiple co-existing grouping overlays
Authors: Ian Taylor
Venue: Proceedings of the second workshop on Use of P2P, GRID and agents for the development of content networks (2007)

This talk discusses issues in defining multiple overlays within P2P networks for the caching of application-data as well as conventional metadata i.e. adverts, or locations to data. I will discuss work carried out at Cardiff in this area that is being built on top of the P2PS middleware, which allows new types of super-peer overlays to be defined through grouping. Such overlays extend super-peer capabilities to help programmers create schemes for defining new ways for locating data sets as well as adverts. Data-caching groups co-exist with the conventional super-peer overlay, which still bootstraps the network by providing the discovery backbone. Parameters for super-peer or data caching groups can also be adjusted e.g. number of super-peer conenctions, caching policies (replication), security policies, etc, and we are also building interfaces for defining new matchmaking algorithms (for matching adverts with queries) as well as more sophisticated schemes for organising super peers (e.g. distributed hashtables, routing tables, agents, etc.) to be plugged into the network.
IREEL: remote experimentation with real protocols and applications over an emulated network
Authors: Laurent Dairaine, Guillaume Jourjon, Emmanuel Lochin, Sebastien Ardon
Venue: ACM SIGCSE Bulletin (2007)

This paper presents a novel e-learning platform called IREEL. IREEL is a virtual laboratory allowing students to drive experiments with real Internet applications and end-to-end protocols in the context of networking courses. This platform consists in a remote network emulator offering a set of pre-defined applications and protocol mechanisms. Experimenters configure and control the emulation and the end-systems behavior in order to perform tests, measurements, and observations on protocols or applications operating under controlled specific networking conditions. A set of end-to-end mechanisms, mainly focusing on transport and application-level protocols, are currently available. IREEL is scalable and easy to use thanks to an ergonomic web interface.
Transient addressing for related processes: improved firewalling by using IPV6 and multiple addresses per host
Authors: Peter M. Gleitz Steven M. Bellovin
Venue: Proceedings of the 10th conference on USENIX Security Symposium - Volume 10 (2001)

Traditionally, hosts have tended to assign relatively few network addresses to an interface for extended periods. Encouraged by the new abundance of addressing possibilities provided by IPv6, we propose a new method, called Transient Addressing for Related Processes (TARP), whereby hosts temporarily employ and subsequently discard IPv6 addresses in servicing a client host's network requests. The method provides certain security advantages and neatly finesses some well-known firewall problems caused by dynamic port negotiation used in a variety of application protocols. A prototype implementation exists as a small set of kame/BSD kernel enhancements and allows socket programmers and applications nearly transparent access to TARP addressing's advantages.
Optimizing End-to-End Latencies by Adaptation of the Activation Events in Distributed Automotive Systems
Authors: Marco Di Natale, Claudio Pinello, Paolo Giusto, Alberto Sangiovanni Vincentelli
Venue: Proceedings of the 13th IEEE Real Time and Embedded Technology and Applications Symposium (2007)

Schedulability theory provides support for the analysis of the worst case latencies in distributed computations when the architecture of the system is known and the communication and synchronization mechanisms have been defined. In the design of complex automotive systems, however, a great benefit of schedulability analysis may come from its use as an aid in the exploration of the software architecture configurations that can best support the target application. We present an optimization algorithm that leverages the trade-offs between the purely periodic and the data-driven activation models to meet the latency requirements of distributed vehicle functions. We demonstrate its effectiveness on a complex automotive architecture.
Graphic Visualization of the 802.11 DCF Protocol under the NS-2 Simulator
Authors: Ryad Ben-El-Kezadri, Farouk Kamoun
Venue: Proceedings of the 40th Annual Simulation Symposium (2007)

The IEEE 802.11 standard uses the Distributed Coordination Function (DCF) protocol to share the medium among multiple stations. DCF is implanted in all the mobile ad-hoc networks (MANET) simulators but its validation poses a true problem considering both the diversity of the models and their simplicity. The validation systems being hard to implement, the visualization tools represent, by comparison, auxiliary applications much more simple to develop. Behind their apparent simplicity, the graphic traces are extremely powerful teaching aids able to bring images of the DCF dysfunctions observed during the simulation execution. For this purpose, the simulation events are logged in trace files and then displayed in the form of timeline. The main contribution of this work is the definition of a tool allowing visualization of the network simulators activity at the data link layer. To show the potential of the approach, screenshots showing the dysfunctions observed in the NS-2 simulator are presented and analyzed.
Simulating Emergent Properties of Coordination in Maude: the Collective Sort Case
Authors: Matteo Casadei, Luca Gardelli, Mirko Viroli
Venue: Electronic Notes in Theoretical Computer Science (ENTCS) (2007)

Recent coordination languages and models are moving towards the application of techniques coming from the research context of complex systems: adaptivity and self-organization are exploited in order to tackle the openness, dynamism and unpredictability of today's distributed systems. In this area, systems are to be described using stochastic models, and simulation is a valuable tool both for analysis and design. Accordingly, in this work we focused on modelling and simulating emergent properties of coordination techniques. We first develop a framework acting as a general-purpose engine for simulating stochastic transition systems, built as a library for the Maude term rewriting system. We then evaluate this tool to a coordination problem called collective sort, where autonomous agents move tuples across different tuple spaces according to local criteria, and resulting in the emergence of the complete clustering property.
Cryptographic device support for FreeBSD
Authors: Samuel J. Leffler
Venue: Proceedings of the BSD Conference 2003 on BSD Conference (2003)

FreeBSD recently adopted the OpenBSD Cryptographic Framework [Keromytis et al, 2003]. In doing so it was necessary to convert the core framework to function correctly in a fully-preemptive/multiprocessor operating system environment. In addition several issues with the basic design were found to cause significant performance loss. After addressing these issues we found that FreeBSD outperformed OpenBSD on identical hardware by as much as 100% in tests that exercise only the cryptographic framework. These optimizations result in similar performance improvements for facilities like IPsec that make heavy use of the cryptographic framework. We observed that FreeBSD's Fast IPsec [Leffler, 2003] typically outperforms OpenBSD's IPsec implementation [Miltchev et al, 2002] by more than 50% on identical hardware. We conclude that the OCF cryptographic API can be optimized and re-tuned to deliver substantially better performance than the original OCF implementation with large gains in both throughput and latency. Moreover these changes can be made with no impact on clients of the cryptographic framework: both user and kernel sofware designed for the original OCF is easily ported to the FreeBSD implementation of OCF.
An update calculus for expressing type-safe program updates
Authors: Martin Erwig, Deling Ren
Venue: Science of Computer Programming (2007)

The dominant share of software development costs is spent on software maintenance, particularly the process of updating programs in response to changing requirements. Currently, such program changes tend to be performed using text editors, an unreliable method that often causes many errors. In addition to syntax and type errors, logical errors can be easily introduced since text editors cannot guarantee that changes are performed consistently over the whole program. All these errors can cause a correct and perfectly running program to become instantly unusable. It is not surprising that this situation exists because the ''text-editor method'' reveals a low-level view of programs that fails to reflect the structure of programs. We address this problem by pursuing a programming-language-based approach to program updates. To this end we discuss in this paper the design and requirements of an update language for expressing update programs. We identify as the essential part of any update language a scope update that performs coordinated update of the definition and all uses of a symbol. As the underlying basis for update languages, we define an update calculus for updating lambda calculus programs. We develop a type system for the update calculus that infers the possible type changes that can be caused by an update program. We demonstrate that type-safe update programs that fulfill certain structural constraints preserve the type correctness of lambda terms. The update calculus can serve as a basis for higher-level update languages, such as for Haskell or Java.
Analysis and Design of Associative Memories Based on Recurrent Neural Networks with Linear Saturation Activation Functions and Time-Varying Delays
Authors: Zhigang Zeng, Jun Wang
Venue: Neural Computation (2007)

In this letter, some sufficient conditions are obtained to guarantee recurrent neural networks with linear saturation activation functions, and time-varying delays have multiequilibria located in the saturation region and the boundaries of the saturation region. These results on pattern characterization are used to analyze and design autoassociative memories, which are directly based on the parameters of the neural networks. Moreover, a formula for the numbers of spurious equilibria is also derived. Four design procedures for recurrent neural networks with linear saturation activation functions and time-varying delays are developed based on stability results. Two of these procedures allow the neural network to be capable of learning and forgetting. Finally, simulation results demonstrate the validity and characteristics of the proposed approach.
Resource Discovery in Ubiquitous Health Care
Authors: Gautham Pallapa, Sajal Das
Venue: Proceedings of the 21st International Conference on Advanced Information Networking and Applications Workshops - Volume 02 (2007)

Ubiquitous computing is an emerging paradigm for health care environments, in which devices must blend into the background unobtrusively, collaborating to provide value-added services for users. Insufficient information flow and coordination are some of the main concerns in a ubiquitous health care environment. Resources are, therefore, essential to the success of this technology and, as a result, both resource discovery and management play a vital role in sustainable ubiquitous deployment. In this paper, we present a novel resource discovery mechanism for ubiquitous computing environments using Resource Index nodes (RIns) and mobile agents. The context information needed to process a query is identified and mobile agents are deployed to explore the ubiquitous environment for requested resources. We present a health care scenario and evaluate our proposed resource discovery method.
Adaptive Thresholding Based on Co-occurrence Matrix Edge Information
Authors: M. M. Mokji, S. A. R. Abu Bakar
Venue: Proceedings of the First Asia International Conference on Modelling & Simulation (2007)

In this paper, an adaptive thresholding technique based on gray level co-occurrence matrix (GLCM) is presented to handle images with fuzzy boundaries. As GLCM contains information on the distribution of gray level transition frequency and edge information, it is very useful for the computation of threshold value. Here the algorithm is designed to have flexibility on the edge definition so that it can handle the object's fuzzy boundaries. By manipulating information in the GLCM, a statistical feature is derived to act as the threshold value for the image segmentation process. The proposed method is tested with the starfruit defect images. To demonstrate the ability of the proposed method, experimental results are compared with three other thresholding techniques.
Data Fusion, De-noising, and Filtering to Produce Cloud-Free High Quality Temporal Composites Employing Parallel Temporal Map Algebra
Authors: Bijay Shrestha, Charles G. O'Hara, Preeti Mali
Venue: Proceedings of the 35th Applied Imagery and Pattern Recognition Workshop (2006)

Remotely sensed images from satellite sensors such as MODIS Aqua and Terra provide high temporal resolution and wide area coverage. Unfortunately, these images frequently include undesired cloud and water cover. Areas of cloud or water cover preclude analysis and interpretation of terrestrial land cover, vegetation vigor, and/or analysis of change. Cross platform multi-temporal image compositing techniques may be employed to create daily synthetic cloud free images using fused images from Aqua and Terra MODIS satellite images, and then creating a composite that includes representative values derived from a set of possibly cloudy satellite images collected during a given longer time period of interest. Spatio-temporal analytical processing methods that utilize moderate spatial resolution satellite imagery with high temporal resolution to create multi-temporal composites are data intensive and computationally intensive. Therefore, a study of the strategies using high performance parallel solutions is required. This research focuses on analyzing the fusion, de-noising, filtering, and compositing strategies for vegetation indices using parallel temporal map algebra. The report provides objective findings on methods and the relative benefits observed from various analysis methods and parallelization strategies.