ppxscal/embedding_network huggingface dataset:
Logic-Free Reasoning in Isabelle/Isar
Authors: Stefan Berghofer, Makarius Wenzel
Venue: Proceedings of the 9th AISC international conference, the 15th Calculemas symposium, and the 7th international MKM conference on Intelligent Computer Mathematics (2008)

Traditionally a rigorous mathematical document consists of a sequence of definition --- statement --- proof. Taking this basic outline as starting point we investigate how these three categories of text can be represented adequately in the formal language of Isabelle/Isar.Proofs represented in human-readable form have been the initial motivation of Isar language design 10 years ago. The principles developed here allow to turn deductions of the Isabelle logical framework into a format that transcends the raw logical calculus, with more direct description of reasoning using pseudo-natural language elements.Statements describe the main result of a theorem in an open format as a reasoning scheme, saying that in the context of certain parameters and assumptions certain conclusions can be derived. This idea of turning Isar context elements into rule statements has been recently refined to support the dual form of elimination rules as well.Definitions in their primitive form merely name existing elements of the logical environment, by stating a suitable equation or logical equivalence. Inductive definitions provide a convenient derived principle to describe a new predicate as the closure of given natural deduction rules. Again there is a direct connection to Isar principles, rules stemming from an inductive characterization are immediately available in structured reasoning.All three categories benefit from replacing raw logical encodings by native Isar language elements. The overall formality in the presented mathematical text is reduced. Instead of manipulating auxiliary logical connectives and quantifiers, the mathematical concepts are emphasized.
A statistical approach to the problem of restoring damaged and contaminated images
Authors: R. G. Everitt, R. H. Glendinning
Venue: Pattern Recognition (2009)

We address the problem of automatically identifying and restoring damaged and contaminated images. We suggest a novel approach based on a semi-parametric model. This has two components, a parametric component describing known physical characteristics and a more flexible non-parametric component. The latter avoids the need for a detailed model for the sensor, which is often costly to produce and lacking in robustness. We assess our approach using an analysis of electroencephalographic images contaminated by eye-blink artefacts and highly damaged photographs contaminated by non-uniform lighting. These experiments show that our approach provides an effective solution to problems of this type.
Effective simulations to support academics in inclusive online learning design
Authors: George Papadopoulos, Elaine Pearson, Steve Green
Venue: Proceedings of the 10th international ACM SIGACCESS conference on Computers and accessibility (2008)

Accessibility simulations can give an understanding of the effect a disability may have on the way students access online materials. This paper briefly describes the evaluation of a prototype set of accessibility simulations. The purpose of the prototype was to establish the specification for a second, revised version, which would incorporate the simulation into a learning activity that could be used in Continuing Professional Development (CPD) training for academics. The cognitive overload simulation - part of the second application - has been developed and is subsequently described in detail. In conclusion, this paper discusses planned evaluation of this and similar simulations as an awareness raising tool in workshops for academic staff in Higher Education.
Implementing Boolean Matrix Factorization
Authors: Roman Neruda, Václav Snášel, Jan Platoš, Pavel Krömer, Dušan Húsek, Alexander A. Frolov
Venue: Proceedings of the 18th international conference on Artificial Neural Networks, Part I (2008)

Matrix factorization or factor analysis is an important task helpful in the analysis of high dimensional real world data. There are several well known methods and algorithms for factorization of real data but many application areas including information retrieval, pattern recognition and data mining require processing of binary rather than real data. Unfortunately, the methods used for real matrix factorization fail in the latter case. In this paper we introduce the background of the task, neural network, genetic algorithm and non-negative matrix facrotization based solvers and compare the results obtained from computer experiments.
Efficient Reconstruction of RC4 Keys from Internal States
Authors: Eli Biham, Yaniv Carmeli
Venue: Fast Software Encryption: 15th International Workshop, FSE 2008, Lausanne, Switzerland, February 10-13, 2008, Revised Selected Papers (2008)

In this paper we present an efficient algorithm for the retrieval of the RC4 secret key, given an internal state. This algorithm is several orders of magnitude faster than previously published algorithms. In the case of a 40-bit key, it takes only about 0.02 seconds to retrieve the key, with success probability of 86.4%. Even if the algorithm cannot retrieve the entire key, it can retrieve partial information about the key. The key can also be retrieved if some of the bytes of the initial permutation are incorrect or missing.
Breaking Legacy Banking Standards with Special-Purpose Hardware
Authors: Tim Güneysu, Christof Paar
Venue: Financial Cryptography and Data Security: 12th International Conference, FC 2008, Cozumel, Mexico, January 28-31, 2008. Revised Selected Papers (2008)

In the field of eCommerce, online-banking is one of the major application requiring the usage of modern cryptography to protect the confidentiality and integrity of financial transactions between users and the banking system. In banking applications of some countries, the authorization of user transactions is performed with support of cryptographic One-Time-Password (OTP) tokens implementing ANSI X9.9-based challenge-response protocols.The legacy ANSI X9.9 standard is a DES-based authentication method on which we will demonstrate an attack based on a special-purpose hardware cluster. In this work we show how to break such an OTP-token with little effort in terms of costs and time. With an investment of about US $ 10,000 we are able to perform an attack which computes the key of a DES-based OTP token in less than a week having only three challenge-response pairs. Our attack can even be scaled linearly according to the budget of the attacker resulting in even faster breaking times. With this work, we want to point out once more that the immediate migration from legacy products using the DES algorithm is absolutely mandatory for security critical applications.
Composable Markov Building Blocks
Authors: Sander Evers, Maarten M. Fokkinga, Peter M. Apers
Venue: Proceedings of the 1st international conference on Scalable Uncertainty Management (2007)

In situations where disjunct parts of the same process are described by their own first-order Markov models and only one model applies at a time (activity in one model coincides with non-activity in the other models), these models can be joined together into one. Under certain conditions, nearly all the information to do this is already present in the component models, and the transition probabilities for the joint model can be derived in a purely analytic fashion. This composability provides a theoretical basis for building scalable and flexible models for sensor data.
Describing Data Format Exploits Using Bitstream Segment Graphs
Authors: Michael Hartle, Daniel Schumann, Arsene Botchak, Erik Tews, Max Mühlhäuser
Venue: Proceedings of the 2008 The Third International Multi-Conference on Computing in the Global Information Technology (iccgi 2008) (2008)

Exploits based on data processing bugs are delivered through crafted data that seems to follow a data format, yet is altered in some way to trigger a specific bug during processing, eg. in order to execute contained malicious code. Decomposing crafted data according to the purported data format and the function of its components that are not format-compliant is a step towards understanding the delivery mechanism of an exploit and fixing the vulnerable application. This paper demonstrates the use of Bitstream Segment Graphs for describing the structure of exploits on the example of the TIFF Jailbreak exploit for the Apple iPhone and iPod Touch with firmware 1.1.1.
What's in a Cluster? Automatically Detecting Interesting Interactions in Student E-Discussions
Authors: Jan Miksatko, Bruce M. Mclaren
Venue: Proceedings of the 9th international conference on Intelligent Tutoring Systems (2008)

Students in classrooms are starting to use visual argumentation tools for e-discussions --- a form of debate in which contributions are written into graphical shapes and linked to one another according to whether they, for instance, support or oppose one another. In order to moderate several simultaneous e-discussions effectively, teachers must be alerted regarding events of interest. We focused on the identification of clusters of contributions representing interaction patterns that are of pedagogical interest (e.g., a student clarifies his or her opinion and then gets feedback from other students). We designed an algorithm that takes an example cluster as input and uses inexact graph matching, text analysis, and machine learning classifiers to search for similar patterns in a given corpus. The method was evaluated on an annotated dataset of real e-discussions and was able to detect almost 80% of the annotated clusters while providing acceptable precision performance.
Performance and security issues in peer-to-peer based content distribution networks
Authors: Kam-Wing Ng
Venue:  (2007)

Peer-to-Peer (P2P) networks, especially P2P-based content distribution networks (CDN), have enabled large-scale content distribution without major infrastructure support in recent years. However, P2P-based CDNs suffer from performance issues such as stability and scalability, as well as security threats due to their decentralized nature. In this thesis, we address the performance and security issues in P2P-based CDNs. We first consider a BitTorrent-like file swarming system. A simple mathematical model is presented for understanding its performance. With the model we find that under the stable state the peer distribution follows an asymmetric U-shaped curve, which is determined and influenced by various factors. We also analyze the content availability in the system and study its dying process, in which the integrity of the content is endangered. An innovative "tit-for-tat" unchoking strategy enabling more peers to finish their download jobs and prolong the system's lifetime is proposed. We then consider an application-layer tree-like overlay for the synchronous live media multicasting system. In particular we address the instability issue of the multicast overlay caused by nodes' abrupt departures. A set of algorithms are proposed to improve the overlay's stability based on actively estimating the nodes' lifetime model. To support our solution, we have studied the lifetime model via real-world measurements, and have formally proved the effectiveness of the algorithms. The experimental performance evaluation indicates that our algorithms work inexpensively, and could improve the overlay's stability considerably. We also consider the asynchronous on-demand media (MoD) streaming using P2P networks. In particular, we aim to improve the scalability of the system by proposing a novel probabilistic caching mechanism. Theoretical analysis is presented to show that by engaging the proposed mechanism with a flexible system parameter, better scalability could be achieved by a MoD system with less workload imposed on the server. Moreover, we show by simulation that our proposed caching mechanism could improve the streaming service conceived by peers under various conditions of server capacities and network environments. Finally, for improving the security of P2P-based CDNs against peer misbehaviors, we present a stochastic analytical model for understanding the performance of the P2P rating systems, which are widely engaged for safeguarding P2P-based CDNs. We study two representative designs, namely the unstructured self-managing rating (UMR) system and the structured supervising rating (SSR) system with the model under various network environments and adversary attacks. We also propose a configurable loosely supervising rating (LSR) system, and show that the system works inexpensively, and could make tradeoffs between the features of the UMR and the SSR system, thus providing a better overall performance according to the application context.
Cluster spatial point process models for cosmological applications
Authors: J. Mateu, J. A. Lopez
Venue: Journal of Computational Methods in Sciences and Engineering (2005)

Spatial point process models provide a large variety of complex patterns to model particular clustered situations. Due to model complexity, spatial statistics often relies on simulation methods, such as Markov chain Monte Carlo (MCMC) which draws approximate samples of the target distribution as the equilibrium distribution of a Markov chain. In this paper, we focus on point field models that have been used as particular models of galaxy clustering in both cosmology and spatial statistics. We thus select several cluster models and focus on the cluster random model. We provide an extensive simulation study to analyze their flexibility for cluster modelling, under a large variety of practical situations.
A Comparative Study of Unsupervised Machine Learning and Data Mining Techniques for Intrusion Detection
Authors: Reza Sadoddin, Ali A. Ghorbani
Venue: Proceedings of the 5th international conference on Machine Learning and Data Mining in Pattern Recognition (2007)

During the past number of years, machine learning and data mining techniques have received considerable attention among the intrusion detection researchers to address the weaknesses of knowledgebase detection techniques. This has led to the application of various supervised and unsupervised techniques for the purpose of intrusion detection. In this paper, we conduct a set of experiments to analyze the performance of unsupervised techniques considering their main design choices. These include the heuristics proposed for distinguishing abnormal data from normal data and the distribution of dataset used for training. We evaluate the performance of the techniques with various distributions of training and test datasets, which are constructed from KDD99 dataset, a widely accepted resource for IDS evaluations. This comparative study is not only a blind comparison between unsupervised techniques, but also gives some guidelines to researchers and practitioners on applying these techniques to the area of intrusion detection.
Crossmodal Rhythm Perception
Authors: Maria Jokiniemi, Roope Raisamo, Jani Lylykangas, Veikko Surakka
Venue: Proceedings of the 3rd international workshop on Haptic and Audio Interaction Design (2008)

Research on rhythm perception has mostly been focused on the auditory and visual modalities. Previous studies have shown that the auditory modality dominates rhythm perception. Rhythms can also be perceived through the tactile senses, for example, as vibrations, but only few studies exist. We investigated unimodal and crossmodal rhythm perception with auditory, tactile, and visual modalities. Pairs of rhythm patterns were presented to the subject who made a same-different judgment. We used all possible combinations of the three modalities. The results showed that the unimodal auditory condition had the highest rate (79.2%) of correct responses. The unimodal tactile condition (75.0%) and the auditory-tactile condition (74.2%) were close. The average rate remained under 61.7% when the visual modality was involved. The results confirmed that auditory and tactile modalities are suitable for presenting rhythmic information, and they are also preferred by the users.
George A. Philbrick and Polyphemus: The First Electronic Training Simulator
Authors: Per A. Holst
Venue: IEEE Annals of the History of Computing (1982)

In 1937-1938 George A. Philbrick developed what he called an "Automatic Control Analyzer." The analyzer was an electronic analog computer, hard-wired to carry out a computation, or simulation, of a typical process- control loop. The analyzer consisted of several vacuum-tube amplifier stages interconnected to simulate a three-term PID controller operating on a four-lag process, with a number of switches and potentiometers provided for easy variations in the circuit configurations and parameter values. The whole assembly was battery operated and mounted in a standard rack. It contained a built-in oscilloscope: a Dumont 5-inch oscillograph, Type 208, which was one of the early CRT devices on the industrial market. Philbrick named the single-screen analog computer "Polyphemus, " after the one-eyed Cyclops who, according to Greek mythology, was blinded by Odysseus. 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
Identification of urinary track infections using soft computing techniques
Authors: V. S. Kodogiannis, E. Wadge, P. Chountas, I. Petrounias
Venue: Journal of Computational Methods in Sciences and Engineering (2005)

Sensorial analysis based on the utilisation of human senses, is one of the most important investigation methods in food and chemical analysis. Recently, the use of smell in clinical diagnosis has been rediscovered due to major advances in odour sensing technology and artificial intelligence. An array of gas sensors has been employed to identify in vivo urine samples from patients with suspected uncomplicated UTI who were scheduled for microbiological analysis in a UK Health Laboratory environment. An intelligent model consisting of an odour generation mechanism, rapid volatile delivery and recovery system, and a classifier system based on intelligent techniques has been developed. The implementation of an advanced neural network scheme and the concept of fusion of multiple classifiers dedicated to specific feature parameters have been adopted in this study. The experimental results confirm the validity of the presented methods. This study has shown the potential for early detection of microbial contaminants in urine samples using electronic nose technology.
Programming scilab in ARM linux
Authors: Feng Xia, Longhua Ma, Zhe Peng
Venue: ACM SIGSOFT Software Engineering Notes (2008)

Scilab is a free and open source alternative to commercial scientific software packages for numerical computations. It provides an open programming environment along with a large number of powerful primitives. To realize the full potential of Scilab in embedded systems, this paper presents programming techniques essential for using Scilab in the ARM Linux environment. The Scilab package that usually runs on general-purpose computers is ported to the embedded Linux platform with an ARM9 processor. The programming of embedded software and hardware drivers using the ported Scilab package is addressed. Examples are given for illustrating the programming techniques. The cost of the embedded platform developed in this work is very low thanks to the free nature of the software packages used. The flexibility of embedded software built on this platform can be maximized since the source code is open.
Sketch-Based Navigation in 3D Virtual Environments
Authors: Benjamin Hagedorn, Jürgen Döllner
Venue: Proceedings of the 9th international symposium on Smart Graphics (2008)

Navigation represents the fundamental interaction technique in 3D virtual environments (3D VEs) as it enables the users to explore the 3D world and to interact with its objects. Efficient navigation strategies and techniques are required, which take account of the users and their goals and avoid problems of general navigation methods, such as "getting-lost" situations and confusing view configurations. This paper presents a novel method for specifying and controlling navigation in 3D VEs based on sketching navigation commands. The users sketch their navigation intentions on top of the perspective projection of the 3D scene. The system interprets these sketches regarding their geometry, spatial context, and temporal context. Unlike other sketchy navigation techniques, our approach identifies the hit objects of the underlying 3D scene and takes advantage of their semantics and inherent navigation affordances. The approach has been prototypically implemented for the exploration of a virtual 3D city model with a touch-sensitive display.
Can aromaticity be connected with molecular polarizability? A theoretical study of benzene isomers and five-membered heterocyclic molecules
Authors: R. Soriano Jartín, I. García Cuesta, A. Sánchez de Merás, P. Lazzeretti
Venue: Journal of Computational Methods in Sciences and Engineering (2004)

Extended calculations of molecular electric dipole polarizability tensor, at Hartree-Fock and correlated level of accuracy (MP2, CCS, CC2, CCSD, and CCSD(T)) have been carried out to investigate whether aromaticity could be related to the electric dipole polarizability of planar ring systems. The calculations prove the exaltation of the average property of conjugated molecules, which is possibly due to their easily polarizable &pi;-electron cloud. On the other hand, theoretical out-of-plane polarizability components are smaller in benzene than in any other C$_6$H$_6$ isomer. The aromatic stabilization energies of monosubstituted five-membered conjugated cyclic molecules increase in the same direction as theoretical out-of-plane polarizabilities.
Smooth Interpolating Histograms with Error Guarantees
Authors: Thomas Neumann, Sebastian Michel
Venue: Proceedings of the 25th British national conference on Databases: Sharing Data, Information and Knowledge (2008)

Accurate selectivity estimations are essential for query optimization decisions where they are typically derived from various kinds of histograms which condense value distributions into compact representations. The estimation accuracy of existing approaches typically varies across the domain, with some estimations being very accurate and some quite inaccurate. This is in particular unfortunate when performing a parametric search using these estimations, as the estimation artifacts can dominate the search results. We propose the usage of linear splines to construct histograms with known error guarantees across the whole continuous domain. These histograms are particularly well suited for using the estimates in parameter optimization. We show by a comprehensive performance evaluation using both synthetic and real world data that our approach clearly outperforms existing techniques.