ppxscal/embedding_network huggingface dataset:
Secure and reliable covert channel
Authors: Baishakhi Ray, Shivakant Mishra
Venue: Proceedings of the 4th annual workshop on Cyber security and information intelligence research: developing strategies to meet the cyber security and information intelligence challenges ahead (2008)

We describe the design, implementation and evaluation of a reliable and secure protocol to establish a covert channel that not only maintains a high degree of stealthiness, but also provides reliability despite temporary data loss as well as data confidentiality. An important feature of our proposed protocol is that it can be embedded in any legitimate channel that is based on IP. In this paper, we describe our protocol using ICMP. In particular, the proposed protocol satisfies four important properties: stealthiness, lightweight, confidentiality and integrity, and reliability.
If I were you: double appraisal in affective agents
Authors: Ruth Aylett, Sandy Louchart
Venue: Proceedings of the 7th international joint conference on Autonomous agents and multiagent systems - Volume 3 (2008)

We report the implementation and evaluation of a Simulation Theory (ST) approach to the Theory of Mind in intelligent graphical agents driven by an affective agent architecture FAtiMA. The existing cognitive appraisal mechanism is adapted to produce a second appraisal cycle, a double appraisal, in order to evaluate the emotional impact of possible actions. The action with the greatest emotional impact is selected as a means of producing more interesting dramatic actions. A variant in which the actual minds of characters present are used is also implemented and evaluated. Results show that these mechanisms do produce more interesting stories.
A formal execution semantics and rigorous analytical approach for communicating uml statechart diagrams
Authors: Vitus S. W. Lam
Venue:  (2006)

The major problem of the official UML semantics is it lacks the precise definition which is required for performing a formal analysis and reasoning on statechart diagrams. This thesis first examines a rigorous approach for the formalization of the execution semantics of communicating UML statechart diagrams in the &pi;-calculus. An integrated approach which is based on the formalized execution semantics is then proposed for the equivalence checking and model checking of statechart diagrams. Our formalization transforms a subset of UML statechart diagrams as distinct from statecharts into the &pi;-calculus as a number of processes which communicate via a channel-passing interaction paradigm. Checking equivalence of any two statechart diagrams is transformed to a problem of verifying whether the corresponding &pi;-calculus process expressions are equivalent. An equivalence-checking environment which consists of three software tools is described and demonstrated. The environment allows a user to draw statechart diagrams with Poseidon for UML, translate them into &pi;-calculus representations with SC2PiCal and check whether the statechart diagrams are equivalent using the MWB. Likewise, we put forward a model-checking environment. To verify the correctness of a finite state system represented as multiple interacting statechart diagrams, we specify the design in statechart, diagrams using Poseidon for UML, formalize them in the &pi;-calculus, transform the &pi;-calculus expressions into equivalent NuSMV code using PiCal2NuSMV and verify the system automatically using the NuSMV model checker. Our work illustrates how an integrated approach can provide a more thorough analysis of statechart diagrams. The main contributions of this thesis are: (i) a formal definition of the execution semantics of statechart diagrams; (ii) an integration of different formal methods and tools for analyzing statechart diagrams, and (iii) a practical application of the proposed approach for verifying the correctness of SET/A protocol.
Engineering multilevel overlay graphs for shortest-path queries
Authors: Martin Holzer, Frank Schulz, Dorothea Wagner
Venue: Journal of Experimental Algorithmics (JEA) (2009)

An overlay graph of a given graph G &equals; (V, E) on a subset S &sube; V is a graph with vertex set S and edges corresponding to shortest paths in G. In particular, we consider variations of the multilevel overlay graph used in Schulz et al. [2002] to speed up shortest-path computation. In this work, we follow up and present several vertex selection criteria, along with two general strategies of applying these criteria, to determine a subset S of a graph's vertices. The main contribution is a systematic experimental study where we investigate the impact of selection criteria and strategies on multilevel overlay graphs and the resulting speed-up achieved for shortest-path computation: Depending on selection strategy and graph type, a centrality index criterion, selection based on planar separators, and vertex degree turned out to perform best.
Estimating Effort for Trend Messages in Grouped Bar Charts
Authors: Richard Burns, Stephanie Elzer, Sandra Carberry
Venue: Proceedings of the 5th international conference on Diagrammatic Representation and Inference (2008)

Information graphics found in popular media contain communicative signals which help the viewer infer the graphic designer's intended message. One signal is the relative effort required for different recognition tasks. This paper presents a model of the effort required to recognize a trend in a grouped bar chart. The model is developed using the ACT-R cognitive framework and validated via eye tracking experiments.
A heuristic weight-setting strategy and iteratively updating algorithm for weighted least-squares support vector regression
Authors: Wen Wen, Zhifeng Hao, Xiaowei Yang
Venue: Neurocomputing (2008)

Weighted least-squares support vector machine (WLS-SVM) is an improved version of least-squares support vector machine (LS-SVM). It adds weights on error variables to correct the biased estimation of LS-SVM. Traditional weight-setting algorithm for WLS-SVM depends on results from unweighted LS-SVM and requires retraining of WLS-SVM. In this paper, a heuristic weight-setting method is proposed. This method derives from the idea of outlier mining, and is independent of unweighted LS-SVM. More importantly, a fast iterative updating algorithm is presented, which reaches the final results of WLS-SVM through a few updating steps instead of directly retraining WLS-SVM. Circumstantial experiments on simulated instances and real-world datasets are conducted, demonstrating comparable results of the proposed WLS-SVM and encouraging performance of the fast iterative updating algorithm.
MIRACLE at ImageCLEFanot 2007: Machine Learning Experiments on Medical Image Annotation
Authors: Sara Lana-Serrano, Julio Villena-Román, José Carlos González-Cristóbal, José Miguel Goñi-Menoyo
Venue: Advances in Multilingual and Multimodal Information Retrieval: 8th Workshop of the Cross-Language Evaluation Forum, CLEF 2007, Budapest, Hungary, September 19-21, 2007, Revised Selected Papers (2008)

This paper describes the participation of MIRACLE research consortium at the ImageCLEF Medical Image Annotation task of ImageCLEF 2007. Our areas of expertise do not include image analysis, thus we approach this task as a machine-learning problem, regardless of the domain. FIRE is used as a black-box algorithm to extract different groups of image features that are later used for training different classifiers based on kNN algorithm in order to predict the IRMA code. The main idea behind the definition of our experiments is to evaluate whether an axis-by-axis prediction is better than a prediction by pairs of axes or the complete code, or vice versa.
A Clustering Algorithm Based on Generalized Stars
Authors: Airel Pérez Suárez, José E. Pagola
Venue: Proceedings of the 5th international conference on Machine Learning and Data Mining in Pattern Recognition (2007)

In this paper we present a new algorithm for document clustering called Generalized Star (GStar). This algorithm is a generalization of the Star algorithm proposed by Aslam et al., and recently improved by them and other researchers. In this method we introduced a new concept of star allowing a different star-shaped form with better overlapping clusters. The evaluation experiments on standard document collections show that the proposed algorithm outperforms previously defined methods and obtains a smaller number of clusters. Since the GStar algorithm is relatively simple to implement and is also efficient, we advocate its use for tasks that require clustering, such as information organization, browsing, topic tracking, and new topic detection.
Preconditioner updates applied to CFD model problems
Authors: Philipp Birken, Jurjen Duintjer Tebbens, Andreas Meister, Miroslav Tůma
Venue: Applied Numerical Mathematics (2008)

This paper deals with solving sequences of nonsymmetric linear systems with a block structure arising from compressible flow problems. The systems are solved by a preconditioned iterative method. We attempt to improve the overall solution process by sharing a part of the computational effort throughout the sequence. Our approach is fully algebraic and it is based on updating preconditioners by a block triangular update. A particular update is computed in a black-box fashion from the known preconditioner of some of the previous matrices, and from the difference of involved matrices. Results of our test compressible flow problems show, that the strategy speeds up the entire computation. The acceleration is particularly important in phases of instationary behavior where we saved about half of the computational time in the supersonic and moderate Mach number cases. In the low Mach number case the updated decompositions were similarly effective as the frozen preconditioners.
Designing Specific Weighted Similarity Measures to Improve Collaborative Filtering Systems
Authors: Laurent Candillier, Frank Meyer, Françoise Fessant
Venue: Proceedings of the 8th industrial conference on Advances in Data Mining: Medical Applications, E-Commerce, Marketing, and Theoretical Aspects (2008)

The aim of collaborative filtering is to help users to find items that they should appreciate from huge catalogues. In that field, we can distinguish user-based from item-based approaches. The former is based on the notion of user neighbourhoods while the latter uses item neighbourhoods.The definition of similarity between users and items is a key problem in both approaches. While traditional similarity measures can be used, we will see in this paper that bespoke ones, that are tailored to type of data that is typically available (i.e. very sparse), tend to lead to better results.Extensive experiments are conducted on two publicly available datasets, called MovieLens and Netflix. Many similarity measures are compared. And we will show that using weighted similarity measures significantly improves the results of both user- and item-based approaches.
On the detection of outliers for water levels of Langat River
Authors: Kamarulzaman Ibrahim, Rafizah Rajali, Azami Zaharim
Venue: Proceedings of the 1st WSEAS International Conference on Multivariate Analysis and its Application in Science and Engineering (2008)

Outliers are of concerned by many researchers since they could possibly provide very useful information or obscure the final time series model. Robust methods are often used to reduce the effect of outlying observation in the model. In this study, we identify the type of outliers using classical least squares method and robust least median square method for 104 weekly mean water level of Langat River from January 2002 to December 2003. The results based on the two techniques are compared and it is found that the robust least median squares method successfully unmasked the effect of outlier as compared to the least squares method.
Performance Issues of Synchronisation in the MPI-2 One-Sided Communication API
Authors: Lars Schneidenbach, David Böhme, Bettina Schnor
Venue: Proceedings of the 15th European PVM/MPI Users' Group Meeting on Recent Advances in Parallel Virtual Machine and Message Passing Interface (2008)

The efficient implementation of one-sided communication for cluster environments is a challenging task. Here, we present and discuss performance issues which are inherently created by the design of the MPI-2 API specification.Based on our investigations, we propose an one-sided communication API called NEON. The presented measurements with a real application demonstrate the benefits of the NEON approach.
Mobile Payment Applications: An Exploratory Analysis of the Italian Diffusion Process
Authors: Raffaello Balocco, Antonio Ghezzi, Giuseppe Bonometti, Filippo Renga
Venue: Proceedings of the 2008 7th International Conference on Mobile Business (2008)

The purpose of this paper is to estimate the size of the Italian market for mobile Payment (mPayment) services – referred to payment of services and products, but excluding mobile content – and to identify and assess mPayment applications' main diffusion drivers. The research work involved a census of mPayment applications and the analysis of the most relevant case studies. In the first phase secondary sources were mainly used, while in the second step interviews with top managers of involved companies were conducted. Concerning the research findings, in the first semester of 2006, 21 mPayment applications were identified. Despite several benefits are related to these services (e.g. easiness and versatility of use, visibility, improved service quality, etc.), strong inhibitory factors (e.g. consolidated substitutive products, costinefficiency, etc.) and adoption barriers (e.g. regulations, value chain relationships, etc.) are restricting the users' adoption.
Finitary formal topologies and Stone's representation theorem
Authors: Francesco Ciraulo, Giovanni Sambin
Venue: Theoretical Computer Science (2008)

We study the concept of finitary formal topology, a point-free version of a topological space with a basis of compact open subsets. The notion of finitary formal topology is defined from the perspective of the Basic Picture (introduced by the second author) and thus it is endowed with a binary positivity relation. As an application, we prove a constructive version of Stone's representation theorem for distributive lattices. We work within the framework of a minimalist foundation (as proposed by Maria Emilia Maietti and the second author). Both inductive and co-inductive methods are used in most proofs.
Distributed and Secure Bootstrapping of Mobile Ad Hoc Networks: Framework and Constructions
Authors: Shouhuai Xu, Srdjan Čapkun
Venue: ACM Transactions on Information and System Security (TISSEC) (2008)

Secure bootstrapping of mobile ad hoc networks (MANETs) is a challenging problem in scenarios in which network users (or nodes) do not share trust relationships prior to the network deployment. In recent years, a number of schemes have been proposed to solve this problem, assuming either no or limited trust between the nodes prior to their deployment. Despite numerous proposals, there is no common understanding of the proposed schemes and of the trade-offs that they provide. This has consequences for both researchers and practitioners, who do not have a clear idea how to compare the schemes and how to select a scheme for a given application. In this article, we present a framework that helps in understanding and comparing schemes for secure bootstrapping of MANETs. The framework is general because it is policy-neutral and can accommodate many existing bootstrapping schemes. The proposed framework can equally serve as a good basis for the development of new MANET bootstrapping schemes; we show how the development of the framework leads to two new (classes of) distributed bootstrapping schemes. Within the framework, we not only investigate and characterize the properties of the relevant bootstrapping schemes, but also give methods for practitioners to select the relevant system parameters in the Random Walk and the (Restricted) Random Waypoint mobility models.
A 4+1 Bit Month-Scale Regularity Mining Algorithm with One-Path and Distributed Server Constraints for Mobile Internet
Authors: Toshihiko Yamakami
Venue: Proceedings of the 2nd international conference on Network-Based Information Systems (2008)

Mobile Internet becomes increasing visible in everyday life. As increased penetration leverages mobile application business opportunities, it is crucial to identify methodologies to fit mobile-specific demands. Regularity is one of the important measures to enclose easy-come, easy-go mobile users. It is known that a user with multiple visits in one day with a long interval has a larger revisiting possibility in the following month than the others. The author proposes a 4+1 bit method to incorporate this empirical law in order to cope with the two major mobile restrictions: distributed server environments and large data stream. The proposed method can be performed in a one-path manner with 32-bit word boundary-aware memory compaction. The experimental result shows the method is promising to identify revisiting users under mobile-specific constraints.
Damaged BZip Files Are Difficult to Repair
Authors: Christian Hundt, Ulf Ochsenfahrt
Venue: Proceedings of the 14th annual international conference on Computing and Combinatorics (2008)

bzip is a program written by Julian Seward that is often used under Unix to compress single files. It splits the file into blocks which are compressed individually using a combination of the Burrows-Wheeler-Transformation, the Move-To-Front algorithm, Huffman and Runlength encoding. The author himself stated that compressed blocks that are damaged, i.e., part of which are lost, are essentially non-recoverable. This paper gives a formal proof that this is indeed true: focusing on the Burrows-Wheeler-Transformation, the problem of completing a transformed string, such that the decoded string obeys certain file format restrictions, is NP-hard.
Modular robotic system: a concurrent engineering approch
Authors: Nicu Bîzdoaca, Anca Petrisor, Elvira Bîzdoaca, Ilie Diaconu
Venue: Proceedings of the 10th WSEAS International Conference on Automatic Control, Modelling & Simulation (2008)

The modularity of robotic subsystems is a big opportunity for robotics to compel recognition on the market as a viable and efficient alternative, thanks to the development of standardized modulus, especially, but also because of the robots' features-such as productivity and flexibility. The idea of this proposal roots in the structure of a personal computer. The winding and the upgrade of a pc is an extremely simple and quick process thanks to the standardization of the functional modulus. Extrapolating this idea to robots, and to robotic systems, in general, it is necessary the conceiving of a modular system, as far back as in the primary design faze. The modular system should be conceived as intelligent structures with a high degree of sensorial, communicational, functional and control autonomy. These elements are presented and experimented with functional models, for validation. The conclusions are formulated and future directions are targeted.
Detecting Action Items in Meetings
Authors: Gabriel Murray, Steve Renals
Venue: Proceedings of the 5th international workshop on Machine Learning for Multimodal Interaction (2008)

We present a method for detecting action items in spontaneous meeting speech. Using a supervised approach incorporating prosodic, lexical and structural features, we can classify such items with a high degree of accuracy. We also examine how well various feature subclasses can perform this task on their own.
Autonomy in Virtual Agents: Integrating Perception and Action on Functionally Grounded Representations
Authors: Argyris Arnellos, Spyros Vosinakis, George Anastasakis, John Darzentas
Venue: Proceedings of the 5th Hellenic conference on Artificial Intelligence: Theories, Models and Applications (2008)

Autonomy is a fundamental property for an intelligent virtual agent. The problem in the design of an autonomous IVA is that the respective models approach the interactive, environmental and representational aspects of the agent as separate to each other, while the situation in biological agents is quite different. A theoretical framework indicating the fundamental properties and characteristics of an autonomous biological agent is briefly presented and the interactivist model of representations combined with the concept of a semiotic process are used as a way to provide a detailed architecture of an autonomous agent and its fundamental characteristics. A part of the architecture is implemented as a case study and the results are critically discussed showing that such architecture may provide grounded representational structures, while issues of scaling are more difficult to be tackled.
Fuzzy Naive Bayesian Classification in RoboSoccer 3D: A Hybrid Approach to Decision Making
Authors: Carlos Bustamante, Leonardo Garrido, Rogelio Soto
Venue: RoboCup 2006: Robot Soccer World Cup X (2006)

We propose the use of a Fuzzy Naive Bayes classifier with a MAP rule as a decision making module for the RoboCup Soccer Simulation 3D domain. The Naive Bayes classifier has proven to be effective in a wide range of applications, in spite of the fact that the conditional independence assumption is not met in most cases. In the Naive Bayes classifier, each variable has a finite number of values, but in the RoboCup domain, we must deal with continuous variables. To overcome this issue, we use a fuzzy extension known as the Fuzzy Naive Bayes classifier that generalizes the meaning of an attribute so it does not have exactly one value, but a set of values to a certain degree of truth. We implemented this classifier in a 3D team so an agent could obtain the probabilities of success of the possible action courses given a situation in the field and decide the best action to execute. Specifically, we use the pass evaluation skill as a test bed. The classifier is trained in a scenario where there is one passer, one teammate and one opponent that tries to intercept the ball. We show the performance of the classifier in a test scenario with four opponents and three teammates. After a brief introduction, we present the specific characteristics of our training and test scenarios. Finally, results of our experiments are shown.
Modernizing Software & System Engineering Processes
Authors: Liliana Favre
Venue: Proceedings of the 2008 19th International Conference on Systems Engineering (2008)

There is an increased demand of reengineering of legacy systems that are still business-critical in order to extend their useful lifetime. The success of system modernization depends on the existence of technical frameworks for information integration and tool interoperation like the Model Driven Architecture (MDA). Validation, verification and consistency are crucial activities in the modernization of systems that are critical to safety, security and economic profits. This paper contributes an MDA-based framework for modernizing systems. We propose an integration of compiler techniques, metamodeling techniques and formal specification to define rigorous software reengineering processes.