ppxscal/embedding_network huggingface dataset:
Towards a Solution to the "Runs" Conjecture
Authors: Maxime Crochemore, Lucian Ilie, Liviu Tinta
Venue: Proceedings of the 19th annual symposium on Combinatorial Pattern Matching (2008)

The "runs" conjecture, proposed by [Kolpakov and Kucherov, 1999], states that the number of occurrences of maximal repetitions (runs) in a string of length n is at most n. The best bound to date, due to [Crochemore and Ilie, 2007], is 1.6n. Here we improve very much this bound using a combination of theory and computer verification. Our best bound is 1.048n but actually solving the conjecture seems to be now only a matter of time.
Software Security
Authors: Gary McGraw
Venue: IEEE Security and Privacy (2004)

Software security is the idea of engineering software so that it continues to function correctly under malicious attack. Most technologists acknowledge this undertaking's importance, but they need some help in understanding how to tackle it. This new department aims to provide that help by exploring software security best practices.
A Computational Experiment to Describe Opinion Formation Using a Master Equation and Monte Carlo Simulations
Authors: Sarantos Psycharis, Evi Makri-Botsari, Gregorios Mouladidis, Fotini Paraskeva, Vassilis Tatsis
Venue: Proceedings of the 1st world summit on The Knowledge Society: Emerging Technologies and Information Systems for the Knowledge Society (2008)

We propose a computer simulation model aiming to describe the interaction of students in a learning environment composed of the teacher, the students in a collaborative project and the educational material. Our aim is to investigate the change of the opinion of students when they interact with an agent with different opinion. This model can apply to all levels of education in order to explore the reconciliation or not of different opinions during the teaching and learning sequence as well as to examine the resistance of students to new challenges and concepts. The idea is based on the social impact theory and uses methods of Computational Physics, mainly the Monte Carlo techniques and the notion of master equation. Results from simulations indicate that opinion formation is established for different values of the populations when the temperature is below the critical temperature.
A General Long-Time Molecular Dynamics Scheme in Atomistic Systems: Hyperdynamics in Entropy Dominated Systems
Authors: Xin Zhou, Yi Jiang
Venue: Proceedings of the 7th international conference on Computational Science, Part I: ICCS 2007 (2007)

We extend the hyperdynamics method developed for low-dimensional energy-dominated systems, to simulate slow dynamics in more general atomistic systems. We show that a few functionals of the pair distribution function forms a low-dimensional collective space, which is a good approximation to distinguish stable and transitional conformations. A bias potential that raises the energy in stable regions, where the system is at local equilibrium, is constructed in the pair-correlation space on the fly. Thus a new MD scheme is present to study any time-scale dynamics with atomic details. We examine the slow gas-liquid transition of Lennard-Jones systems and show that this method can generate correct long-time dynamics and focus on the transition conformations without prior knowledge of the systems. We also discuss the application and possible improvement of the method for more complex systems.
The Heaviside Step Function and MATLAB
Authors: Matilde P. Legua, Isabel Morales, Luis M. Sánchez Ruiz
Venue: Proceeding sof the international conference on Computational Science and Its Applications, Part I (2008)

Mathematical software enables to solve in a very simple way differential equations arisen from casual systems. In this note we point out that the solutions provided by MATLAB may occasionally neglect Heaviside step functions in the output when instant impulses or piecewise continuous functions appear in the input.
Stabilized Procedures for Finite Element Analysis in Saturated Soils Under Cyclic Loading
Authors: Maosong Huang, Ming Liu, O. C. Zienkiewicz
Venue: Proceedings of the 7th international conference on Computational Science, Part III: ICCS 2007 (2007)

Abstract. Conventional finite element procedures with equal order interpolations for saturated soil dynamic u ¿ p formulation have been experiencing numerical difficulties for the problems concerning with small permeability and neglectable compressibility of pore-fluid. Such difficulties can be avoided by the staggered implicit-implicit algorithm and the directá - method which were introduced by Huang et al. (2004). Several numerical examples for surface step loadings were given to demonstrate the performance of the proposed methods. Since the numerical examples for the step loadings are not typical for dynamic problems, which usually show the relatively strong oscillation nature of dynamic behaviors. Due to the necessity to show the effectiveness of the proposed stabilization techniques for cyclic loading problems, two numerical examples regarding saturated soils subject to a surface cyclic loading are presented in this paper. Discussion on uniform and nonuniform mesh configuration is also given.
Extraction of Socio-semantic Data from Chat Conversations in Collaborative Learning Communities
Authors: Traian Rebedea, Stefan Trausan-Matu, Costin-Gabriel Chiru
Venue: Proceedings of the 3rd European conference on Technology Enhanced Learning: Times of Convergence: Technologies Across Learning Contexts (2008)

Online collaboration among communities of practice using text-based tools, such as instant messaging, forums and web logs (blogs), has become very popular in the last years, but it is difficult to automatically analyze all their content due to the problems of natural language understanding software. However, useful socio-semantic data can be retrieved from a chat conversation using ontology-based text mining techniques. In this paper, a novel approach for detecting several kinds of semantic data from a chat conversation is presented. This method uses a combination of a dialogistic, socio-cultural perspective and of classical knowledge-based text processing methods. Lexical and domain ontologies are used. A tool has been developed for the discovery of the most important topics and of the contribution of each participant in the conversation. The system also discovers new, implicit references among the utterances of the chat in order to offer a multi-voiced representation of the conversation. The application offers a panel for visualizing the threading of the subjects in the chat and the contributions function. The system was experimented on chat sessions of small groups of students participating in courses on Human-Computer Interaction and Natural Language Processing in "Politehnica" University of Bucharest, Romania.
Characterizing and Computing Minimal Cograph Completions
Authors: Daniel Lokshtanov, Federico Mancini, Charis Papadopoulos
Venue: Proceedings of the 2nd annual international workshop on Frontiers in Algorithmics (2008)

A cograph completion of an arbitrary graph G is a cograph supergraph of G on the same vertex set. Such a completion is called minimal if the set of edges added to G is inclusion minimal. In this paper we present two results on minimal cograph completions. The first is a a characterization that allows us to check in linear time whether a given cograph completion is minimal. The second result is a vertex incremental algorithm to compute a minimal cograph completion H of an arbitrary input graph G in O(V(H) + E(H)) time.
Neural Network Implementation of Image Edge Detectors
Authors: Majid Aghababaie, Gholamali Rezairad
Venue: Proceedings of the 2008 Fifth International Conference on Computer Graphics, Imaging and Visualisation (2008)

Edges are basic low level primitives for image processing. Edge detection is one of the most common operations in image analysis. In this paper a new implementation for edge detection methods using LVQ neural nework is proposed. For instance Susan and Canny and Sobel edge detectors are modeled by neural network and simulation results are very promising.
Software Verification and Software Engineering a Practitioner's Perspective
Authors: Anthony Hall
Venue: Verified Software: Theories, Tools, Experiments: First IFIP TC 2/WG 2.3 Conference, VSTTE 2005, Zurich, Switzerland, October 10-13, 2005, Revised Selected Papers and Discussions (2005)

The web page for this conference announcesa "Grand Challenge" of crucial relevance to society: ensuring that the software of the future will be error-free.According to the Scope and ObjectivesIn the end, the conference should work towards the achievement of the long-standing challenge of the Verifying Compiler.I want to question whether this long-standing challenge is really relevant to the greater goal of achieving trustworthy software. Instead, I suggest that research in verification needs to support a larger effort to improve the software engineering process. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Color Scratches Removal Using Human Perception
Authors: Vittoria Bruni, Paola Ferrara, Domenico Vitulano
Venue: Proceedings of the 5th international conference on Image Analysis and Recognition (2008)

This paper presents a model for the detection and restoration of line scratches from color movies. Light diffraction through the color film support allows the modeling of both the shape and the color of the defects, while perception laws enable their automatic detection and removal. The quality of the restored images is high, while the implemented algorithms are computationally inexpensive and completely user's independent.
Balancing Quality and Performance of Task Distribution in Workflow Based on Resource Aptitude
Authors: Renê Rodrigues Veloso, Autran Macêdo
Venue: Proceedings of the 7th international conference on Computational Science, Part III: ICCS 2007 (2007)

The distribution of tasks in a workflow system, in general, does not consider resource aptitude. Resources that share the same role in a workflow can have different degrees of aptitude to a task. This work proposes an extension to task distribution strategies and presents the use of this extension in the selection of resources to tasks. The experiments presented here demonstrate the effectiveness of the extension. A comparison with traditional strategies has shown gains in terms of time and quality of tasks executed.
Designing Verification Conditions for Software
Authors: K. Rustan Leino
Venue: Proceedings of the 21st international conference on Automated Deduction: Automated Deduction (2007)

Software verification technology has the potential to improve the quality of software. The basic technique is to generate verification conditions for a given program and to discharge these proof obligations using a theorem prover. Encoding the verification conditions is a delicate process, not just because it must capture the intended programming semantics, but also because it must yield formulas that a theorem prover can process effectively.In this talk, I will discuss the process of generating verification conditions in the program verifier for the object-oriented language Spec#. I will highlight design decisions we have made in modeling programs and targeting SMT solvers, lessons we have learned, and challenges that remain ahead.
Design and Analysis of a QoS Signaling Protocol for Mobile IP Networks
Authors: Qing Xiuhua
Venue: Proceedings of the 2008 ISECS International Colloquium on Computing, Communication, Control, and Management - Volume 02 (2008)

The coupling of signaling protocols for mobility management and resource reservation plays an important role to achieve Quality-of-Service (QoS) in mobile environments. In this paper, we analyze the effects of node mobility on the interaction between QoS signaling protocols and mobility management protocols, and propose an efficient QoS signaling protocol which operates adaptively in mobile IP networks. The key features of the protocol include crossover node discovery and local repair to achieve seamless services. Our simulation and experimental results show that the proposed protocol works well in mobile environments.
Model of Cue Extraction from Distractors by Active Recall
Authors: Adam Ponzi
Venue: Neural Information Processing: 14th International Conference, ICONIP 2007, Kitakyushu, Japan, November 13-16, 2007, Revised Selected Papers, Part I (2007)

Cues are informative signals animals must use to make decisions in order to obtain rewards, usually after intervening temporal delays, typified in the cue-action-reward task. In behavioural experiments the cue is often clearly distinguished from other stimuli, by a salience such as brightness for example, however in the real world animals face the problem of recognizing real cues from among other environmental distracting stimuli. Furthermore once the cue is recognized it must cause the animal to make a certain action to obtain reward. Therefore the animal faces a compound chicken-and-egg problem to obtain reward. First it must recognize the cue and then it must learn that the cue must initiate a certain action. But how can the animal recognize the cue before it has learned the action to obtain reward, since in this initial learning stage the cue is only partially predictive of reward? Here we present a simple neural network model of how animals extract cues from background distractor stimulus, all presented with equal salience, based on successive testing of different stimulus-action allocations over several trials. A stimulus is selected and gated into working memory to drive an action and then reactivated at the end period to be reinforced if correct. If the stimulus is not reinforced over several trials it is suppressed and a different stimulus is selected. If the stimulus is a real cue but it drives the incorrect action, its cue-action allocation is suppressed. This mechanism is enhanced by the property of cue mutual exclusion in trials which also provides a simple model of bottom-up attention and pop-out. The model is based on the cortical and hippocampal projections to the dopamine system through the striatum including a model of salience gated working memory and a reinforcement and punishment system based on dopamine feedback balance. We illustrate the model by numerical simulations of a rat learning to navigate a T-maze and show how it deterministically discovers the correct cue-action allocations. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Enhancing Library Services with Web 2.0 Functionalities
Authors: Dimitris Gavrilis, Constantia Kakali, Christos Papatheodorou
Venue: Proceedings of the 12th European conference on Research and Advanced Technology for Digital Libraries (2008)

In this paper, a prototype of an Online Public Access Catalog (OPAC) is presented. This new OPAC features new functionalities and utilizes web 2.0 technologies in order to deliver improved search and retrieval services. Some of these new services include social tag annotations, user opinions and ranks and tag-based similarity searches. The prototype is evaluated by a user group through questionnaires, interviews and with the system's integrated logging mechanism. The results are encouraging enough and show that Library 2.0 technologies seem to be acceptable by the majority of the users.
Theory of Quantum Key Distribution: The Road Ahead (Invited Talk)
Authors: Norbert Lütkenhaus
Venue: Proceedings of the 3rd international conference on Information Theoretic Security (2008)

Quantum Key Distribution (QKD) has been an area with lots of research activity. So nearly 25 years after the publication of the Bennett-Brassard 1984 protocol, what is left to do? As a basis of my talk, I will present the ideas of quantum key distribution in a language that emphasizes the common basis with information theoretic secure key distribution schemes that are based on independent noise assumptions in channels. As I will show, the role quantum theory plays is to verify the nature of correlations between sender, receiver and eavesdropper based only on the observations of sender and receiver. For reviews of practical QKD and issues addressed in this presentation, see [1,2,3].Current research directions concentrate on the theoretic side on the optimal method of extracting secret key out of given observed correlations between sender and receiver. As it is the case in the classical scenario, different protocols using for example one-way or two-way communication over an authenticated public channel can have different maximum thresholds for error rates, and can yield different key rates. Other research directions deal with side channels and imperfections that are unavoidable in the implementation of the QKD protocols. After all, in implementations we are not sending 'qubits', the quantum equivalent of classical bits, but real optical signals that have a rich internal structure.As for applications, it is desirable to go beyond the simple point-to-point QKD connection and I will present research done within the European Consortium SECOQC [4] that builds a network demonstrator using trusted repeater stations in Vienna. This demonstrator involves the development of optical technology for the QKD implementation, but also the development of key management structures and routing protocols that are compatible with high-security application scenarios. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Population Coding of Song Element Sequence in the Songbird Brain Nucleus HVC
Authors: Jun Nishikawa, Masato Okada, Kazuo Okanoya
Venue: Neural Information Processing: 14th International Conference, ICONIP 2007, Kitakyushu, Japan, November 13-16, 2007, Revised Selected Papers, Part I (2007)

Birdsong is a complex vocalization composed of various song elements organized according to sequential rules. To reveal the neural representation of song element sequence, we recorded the neural responses to all possible element pairs of stimuli in the Bengalese finch brain nucleus HVC. Our results show that each neuron has broad but differential response properties to element sequences. We calculated the time course of population activity vectors and mutual information between auditory stimuli and neural activities. The clusters of population vectors responding to second elements had a large overlap, whereas the clusters responding to first elements were clearly divided. At the same timing, confounded information also significantly increased. These results indicate that the song element sequence is encoded in a neural ensemble in HVC via population coding.
Semantic Segmentation of Motion Capture Using Laban Movement Analysis
Authors: Durell Bouchard, Norman Badler
Venue: Proceedings of the 7th international conference on Intelligent Virtual Agents (2007)

Many applications that utilize motion capture data require small, discrete, semantic segments of data, but most motion capture collection processes produce long sequences of data. The smaller segments are often created from the longer sequences manually. This segmentation process is very laborious and time consuming. This paper presents an automatic motion capture segmentation method based on movement qualities derived from Laban Movement Analysis (LMA). LMA provides a good compromise between high-level semantic features, which are difficult to extract for general motions, and low-level kinematic features which, often yield unsophisticated segmentations. The LMA features are computed using a collection of neural networks trained with temporal variance in order to create a classifier that is more robust with regard to input boundaries. The actual segmentation points are derived through simple time series analysis of the LMA features.
Security and Interoperability for MANETs and a Fixed Core
Authors: Colin O'Halloran, Andy Bates
Venue: Proceedings of the 27th international conference on Computer Safety, Reliability, and Security (2008)

The problem of ensuring security and interoperability for mobile ad hoc networks that connect to a valuable fixed core infrastructure is discussed. The problem is broken down into three interdependent research areas of Security versus Risk; Identity Management; Verification, Validation and Certification. The research issues for each area are discussed in detail.
Research and Implementation of Knowledge-Enhanced Information Services
Authors: Bo Yang, Hao Wang, Liang Liu, Qian Ma, Ying Chen, Hui Lei
Venue: Proceedings of the 5th international conference on Service-Oriented Computing (2007)

Information isolation has been identified as a big challenge in IT Service Management (ITSM). Existing ITSM practices mostly rely on configuration information and are geared towards individual applications and processes. However, information available in complicated IT infrastructure goes beyond data from the configuration management domain. How to efficiently extract and integrate the hidden knowledge from a wide variety of information sources is a major pain point for ITSM. In this paper, a threading strategy (TS) with KPI mark and knowledge-enhanced information services is proposed to improve ITSM quality. The essential contribution of this work is to organize the highly complex IT service information with KPI mark and to build a knowledge repository for accumulateing and reusing experts' knowledge. In addition, a prototype called BIANCHIN is implemented to explore this knowledge-enhanced information services framework. Finally, a real business application of Cisco VoIP system is used as a case study for evaluating the effectiveness and efficiency of the knowledge-enhanced information services framework.
Password Mistyping in Two-Factor-Authenticated Key Exchange
Authors: Vladimir Kolesnikov, Charles Rackoff
Venue: Proceedings of the 35th international colloquium on Automata, Languages and Programming, Part II (2008)

We study the problem of Key Exchange (KE), where authentication is two-factor and based on both electronically stored long keys and human-supplied credentials (passwords or biometrics). The latter credential has low entropy and may be adversarily mistyped. Our main contribution is the first formal treatment of mistyping in this setting.Ensuring security in presence of mistyping is subtle. We show mistyping-related limitations of previous KE definitions and constructions (of Boyen et al. [6,7,10] and Kolesnikov and Rackoff [16]).We concentrate on the practical two-factor authenticated KE setting where servers exchange keys with clients, who use short passwords (memorized) and long cryptographic keys (stored on a card). Our work is thus a natural generalization of Halevi-Krawczyk [15] and Kolesnikov-Rackoff [16]. We discuss the challenges that arise due to mistyping. We propose the first KE definitions in this setting, and formally discuss their guarantees. We present efficient KE protocols and prove their security.