ppxscal/embedding_network huggingface dataset:
LTL with the freeze quantifier and register automata
Authors: Stéphane Demri, Ranko Lazić
Venue: ACM Transactions on Computational Logic (TOCL) (2009)

A data word is a sequence of pairs of a letter from a finite alphabet and an element from an infinite set, where the latter can only be compared for equality. To reason about data words, linear temporal logic is extended by the freeze quantifier, which stores the element at the current word position into a register, for equality comparisons deeper in the formula. By translations from the logic to alternating automata with registers and then to faulty counter automata whose counters may erroneously increase at any time, and from faulty and error-free counter automata to the logic, we obtain a complete complexity table for logical fragments defined by varying the set of temporal operators and the number of registers. In particular, the logic with future-time operators and 1 register is decidable but not primitive recursive over finite data words. Adding past-time operators or 1 more register, or switching to infinite data words, causes undecidability.
Bringing big systems to small schools: distributed systems for undergraduates
Authors: Jeannie R. Albrecht
Venue: ACM SIGCSE Bulletin (2009)

Distributed applications have become a core component of the Internet's infrastructure. However, many undergraduate curriculums, especially at small colleges, do not offer courses that focus on the design and implementation of distributed systems. The courses that are offered address the theoretical aspects of system design, but often fail to provide students with the opportunity to develop and evaluate distributed applications in real-world environments. As a result, undergraduate students are not as prepared as they should be for graduate study or careers in industry. This paper describes an undergraduate course in Distributed Systems that not only studies the key design principles of distributed systems, but also has a unique emphasis on giving students hands-on access to distributed systems through the use of shared computing testbeds, such as PlanetLab and GENI, and open-source technologies, such as Xen and Hadoop. Using these platforms, students can perform large-scale, distributed experimentation even at small colleges.
Model checking action system refinements
Authors: Graeme Smith, Kirsten Winter
Venue: Formal Aspects of Computing (2009)

Action systems provide a formal approach to modelling parallel and reactive systems. They have a well established theory of refinement supported by simulation-based proof rules. This paper introduces an automatic approach for verifying action system refinements utilising standard CTL model checking. To do this, we encode each of the simulation conditions as a simulation machine, a Kripke structure on which the proof obligation can be discharged by checking that an associated CTL property holds. This procedure transforms each simulation condition into a model checking problem. Each simulation condition can then be model checked in isolation, or, if desired, together with the other simulation conditions by combining the simulation machines and the CTL properties.
Wireless Home Networking in Easy Steps, 2nd edition
Authors: Bill Westhead
Venue:  (2008)

From understanding the basic jargon to setting up and choosing the best products for individual requirements, this handy guide covers every aspect of home networking. Using a simple, step-by-step approach and screenshots, author Bill Westhead explains how to secure and protect a network from unauthorized use and reduce the risk of network hijacking and identity theft. Also here are useful definitions of terms and a troubleshooting guide for identifying common problems with hardware, software, and configurations and quickly solving them.
Adaptive wideband beamforming with sensor delay-lines
Authors: Wei Liu
Venue: Signal Processing (2009)

A novel adaptive wideband beamforming method is proposed, where the tap delays in the traditional method are replaced and only one adaptive coefficient is required for each sensor. In this way, the complex wideband beamforming system with temporal filtering can be avoided by implementing the proposed beamformer with simple analogue circuits for very high frequency and bandwidth applications. Another advantage of this new method is its potential to avoid the beam widening effect at higher off-boresight angels. The effectiveness of the proposed method is verified by simulations.
Larc: a little architecture for the classroom
Authors: Marc L. Corliss, Robert Hendry
Venue: Journal of Computing Sciences in Colleges (2009)

This paper introduces the classroom architecture Larc, which was designed specifically for use in an introductory course on computer architecture. The Larc project has many resources including (among other things) a comprehensive, freely-available student manual, a graphical debugger for helping students write machine/assembly programs, and a Java-like compiler for helping students better understand the role of the compiler and its interaction with the machine.
Temporal Profiling for Opportunistic Partnership Recommendation
Authors: Adriana S. Vivacqua, Carlos Eduardo Mello, Diogo K. Souza, João A. Avellar Menezes, Leandro C. Marques, Marcos S. Ferreira, Jano M. Souza
Venue: Computer Supported Cooperative Work in Design IV: 11th International Conference, CSCWD 2007, Melbourne, Australia, April 26-28, 2007. Revised Selected Papers (2008)

Locating experts or work partners in large communities can sometimes be hard. The most common way of accomplishing this task is through recommendations from known acquaintances. This networked search for others who fit required profiles is a form of social navigation. However, needs, interests and expertise change rapidly, so time is an important factor in this type of situation, and recommendations need to be time-sensitive. This paper presents a peer-to-peer system for social network navigation, which builds user profiles through a temporal analysis of ongoing activities and matches these to find opportunities for collaboration.
SVM Based Shot Boundary Detection Using Block Motion Feature Based on Statistical Moments
Authors: Brojeshwar Bhowmick, Kaustav Goswami
Venue: Proceedings of the 2009 Seventh International Conference on Advances in Pattern Recognition (2009)

Temporal video segmentation is of fundamental importance in order to facilitate user’s access to huge volume of video data as well as for video summarization.The objective of shot boundary detection is to partition the video into meaningful, basic structural units called shots. In this paper, a shot boundary detection technique has been proposed for cuts. The method extracts block feature based similarities from the frames of the input video. Statistical moments up to second order are used to measure the motion present in the frames. Feature vectors are generated using a sliding window over time and are trained by a SVM to identify the cuts.
Energy Consumption of Mobile YouTube: Quantitative Measurement and Analysis
Authors: Yu Xiao, Ramya Sri Kalyanaraman, Antti Yla-Jaaski
Venue: Proceedings of the 2008 The Second International Conference on Next Generation Mobile Applications, Services, and Technologies (2008)

YouTube launched a customized website for mobile devices, which is gaining popularity among users. However, accessing multimedia based Internet services from mobile devices consumes energy, the most critical resource of handheld devices. The energy consumption of YouTube for mobile devices has not been widely studied. In this paper, we present a quantitative study of YouTube's energy consumption in mobile devices based on the measurements carried out on Nokia S60 mobile phones. We further investigate the energy characteristics based on network access technology (WCDMA and WLAN), download technology and storage media used. Our experimental results show that network transmission using WCDMA consumes more energy than when using WLAN. In addition, the power consumption is relevant with the status of network interfaces, and the impact on energy consumption based on the storage media used can be ignored.
In-flight MTF measurement and compensation for the CBERS-2 WFI
Authors: X. Y. Li, X. F. Gu, T. Yu
Venue: International Journal of Remote Sensing (2009)

The Wide-Field Imager (WFI) is one of three payloads onboard the China-Brazil Earth Resources Satellite (CBERS). Limited knowledge of its radiometric characteristics has limited use of its data in China. In this study, our aim was to evaluate the in-flight modulation transfer function (MTF) of the WFI and restore the images. Using the high ground spatial resolution images obtained with the charge-coupled device (CCD) camera also onboard CBERS, a two-image comparison approach was applied to determine the MTF of the WFI, with three pairs of images acquired on different dates. The MTF values measured on different dates were different, especially in the along-orbit direction. As subimage pairs of the Korean scene had the richest information and low relief, MTF values determined from the Korean scene were applied to calculate the half-bandwidths of the WFI and perform the MTF compensation for the WFI images. The results demonstrated that the instant fields of view of the WFI were 317 m, 304 m and 320 m in the cross-orbit, along-orbit and 45°-orbit directions, respectively. As expected, the restored images contained more detail than the original ones.
Two tests for heteroscedasticity in nonparametric regression
Authors: Mario Francisco-Fernández, Juan M. Vilar-Fernández
Venue: Computational Statistics (2009)

In this paper, two new tests for heteroscedasticity in nonparametric regression are presented and compared. The first of these tests consists in first estimating nonparametrically the unknown conditional variance function and then using a classical least-squares test for a general linear model to test whether this function is a constant. The second test is based on using an overall distance between a nonparametric estimator of the conditional variance function and a parametric estimator of the variance of the model under the assumption of homoscedasticity. A bootstrap algorithm is used to approximate the distribution of this test statistic. Extended versions of both procedures in two directions, first, in the context of dependent data, and second, in the case of testing if the variance function is a polynomial of a certain degree, are also described. A broad simulation study is carried out to illustrate the finite sample performance of both tests when the observations are independent and when they are dependent.
GIS Tool for Rural Electrification with Renewable Energies in Latin America
Authors: Javier Domínguez, Irene Pinedo-Pascua
Venue: Proceedings of the 2009 International Conference on Advanced Geographic Information Systems & Web Services (2009)

Renewable energy sources are increasingly being considered as feasible and competitive alternatives in the provision of electricity to isolated rural communities. Electrification planning process must consider the geographical characteristics of the renewable energy sources as well as the social and economical particularities of the target communities, contributing to the long and stable operation of the chosen technologies. GIS are able to manage all the data needed in the decision making process, providing means to compare costs of alternative technologies, based on renewable and non-renewable energy sources. This paper discusses the methodology used by the GIS group for regional integration of Renewable Energies and rural electrification (gTIGER). This method, named IntiGIS, aims to provide the analysis tools we use with more flexibility and dynamism, broadening its application possibilities based on the huge chances given by Geographical Information Technologies. In this paper, an example of GIS to rural electrification carried out in Latin American countries is presented.
Language Classes Defined by Concurrent Finite Automata
Authors: Matthias Jantzen, Manfred Kudlek, Georg Zetzsche
Venue: Fundamenta Informaticae (2008)

This paper presents results regarding the various relations among the language classes defined by Concurrent Finite Automata, relations to other language classes, as well as decidability and closure properties.
Generating ordered set of symmetric group for solving commutation problems
Authors: S. A. Kalinchuk, Yu. L. Sagalovich
Venue: Automation and Remote Control (2009)

In this paper, the recurrent algorithms for construction of generating ordered set of symmetric group are suggested. The bounds of transpositions' numbers in such sets are found.
Training Students to Work Effectively in Partially Distributed Teams
Authors: Rosalie Ocker, Mary Beth Rosson, Dana Kracaw, S. Roxanne Hiltz
Venue: ACM Transactions on Computing Education (TOCE) (2009)

Information technology teams are often partially distributed teams (PDTs). A PDT consists of two or more subteams that are separated geographically. This articles describes research focused on the use of PDTs to engage students in &ldquo;real world&rdquo; IT team learning about the subject matter while also teaching them the skills they will need to work in global software development teams. Findings from a large-scale international study indicate that the introduction of training modules enhanced perceived learning of appropriate PDT teaming behaviors; students with training reported improved shared team identification, trust, awareness, coordination, competence, and conflict with respect to distant subteam members, and higher overall team performance.
Far voxels: a multiresolution framework for interactive rendering of huge complex 3D models on commodity graphics platforms
Authors: Enrico Gobbetti, Fabio Marton
Venue: ACM SIGGRAPH ASIA 2008 courses (2008)

We present an efficient approach for end-to-end out-of-core construction and interactive inspection of very large arbitrary surface models. The method tightly integrates visibility culling and out-of-core data management with a level-of-detail framework. At preprocessing time, we generate a coarse volume hierarchy by binary space partitioning the input triangle soup. Leaf nodes partition the original data into chunks of a fixed maximum number of triangles, while inner nodes are discretized into a fixed number of cubical voxels. Each voxel contains a compact direction dependent approximation of the appearance of the associated volumetric sub-part of the model when viewed from a distance. The approximation is constructed by a visibility aware algorithm that fits parametric shaders to samples obtained by casting rays against the full resolution dataset. At rendering time, the volumetric structure, maintained off-core, is refined and rendered in front-to-back order, exploiting vertex programs for GPU evaluation of view-dependent voxel representations, hardware occlusion queries for culling occluded subtrees, and asynchronous I/O for detecting and avoiding data access latencies. Since the granularity of the multiresolution structure is coarse, data management, traversal and occlusion culling cost is amortized over many graphics primitives. The efficiency and generality of the approach is demonstrated with the interactive rendering of extremely complex heterogeneous surface models on current commodity graphics platforms.
Some Recent Progress in Lattice-Based Cryptography
Authors: Chris Peikert
Venue: Proceedings of the 6th Theory of Cryptography Conference on Theory of Cryptography (2009)

The past decade in computer science has witnessed tremendous progress in the understanding of lattices, which are a rich source of seemingly hard computational problems. One of their most promising applications is to the design of cryptographic schemes that enjoy exceptionally strong security guarantees and other desirable properties.Most notably, these schemes can be proved secure assuming only the worst-case hardness of well-studied lattice problems. Additionally, and in contrast with number-theoretic problems typically used in cryptography, the underlying problems have so far resisted attacks by subexponential-time and quantum algorithms. Yet even with these security advantages, lattice-based schemes also tend to be remarkably simple, asymptotically efficient, and embarrassingly parallelizable.This tutorial will survey the foundational results of the area, as well as some more recent developments. Our particular focus will be on the core hard cryptographic (average-case) problems, some recurring techniques and abstractions, and a few notable applications.
Transport Prices and Costs in Africa: A Review of the Main International Corridors (Directions in Development)
Authors: Supee Teravaninthorn, Gael Raballand
Venue:  (2008)

Transport prices for most African landlocked countries range from 15 to 20 percent of import costs. This is approximately two to three times more than in most developed countries. It is well known that weak infrastructure can account for low trade performance. Thus, it becomes necessary to understand what types of regional transport services operate in landlocked African nations and it is critical to identify the regulation disparities and provision anomalies that hurt infrastructure efficiency, even when the physical infrastructure such as a road transport corridor exists.Transport Prices and Costs in Africa analyzes the various reasons for poor transport performance seen widely throughout Africa and provides a compelling case for a number of national and regional reforms that are vital to the effort to address the underlying causes of high transport prices and costs and service unpredictability seen in Africa. The book will greatly help supervisory authorities throughout the region develop and implement a comprehensive transport policy that will facilitate long-term growth.
Digital Masters: Travel Photography Documenting the World's People & Places (A Lark Photography Book)
Authors: Bob Krist
Venue:  (2008)

As we travel to new places, digital camera in hand, we all feel the desire to capture them forever in images: the scenic vistas, the unique architecture, the people who inhabit that landscape. With this magnificent new study, award-winning National Geographic photographer Bob Krist can help us achieve our goal. Its distinguished from other digital how-tos by its comprehensive scope, easy-to-grasp explanations, inspirational attitude, and upscale aesthetics.Krist examines the technological aspects of shooting digitally on location, and explains how to select the right equipment, from cameras and lenses to flashes and tripods. He offers tips for saving, backing up, and sending images on the road, and gets to the heart of what it takes to portray the true spirit of your subject. He poses such questions as: What makes a truly great photograph? How can you create a well-rounded portrait of a place through its geography, people, and culture? The answers are all illustrated with the authors collection of stunning travel photography to inspire us along the way.
Speech Emotion Classification on a Riemannian Manifold
Authors: Chengxi Ye, Jia Liu, Chun Chen, Mingli Song, Jiajun Bu
Venue: Proceedings of the 9th Pacific Rim Conference on Multimedia: Advances in Multimedia Information Processing (2008)

We present a novel algorithm for speech emotion classification. In contrast to previous methods, we additionally consider the relations between simple features by incorporating covariance matrices as the new feature descriptors. Since non-singular covariance matrices do not lie on a linear space, we endow the space with an affine invariance metric and render it into a Riemannian manifold. After that we use the tangent space to approximate the manifold. Classification is performed in the tangent space and a generalized principal component analysis is presented. We test the algorithm on speech emotion classification and the experiment results show an improvement at around 13%(+3% with PCA) in recognition accuracy. Based on that we are able to train one simple model to accurately differentiate the emotions from both genders.
Importance partitioning in micro-aggregation
Authors: G. Kokolakis, D. Fouskakis
Venue: Computational Statistics Data Analysis (2009)

One of the techniques of data holders for the protection of confidentiality of continuous data is that of micro-aggregation. Rather than releasing raw data (individual records), micro-aggregation releases the averages of small groups and thus reduces the risk of identity disclosure. At the same time the method implies loss of information and often distorts the data. Thus, the choice of groups is very crucial to minimize the information loss and the data distortion. No exact polynomial algorithms exist up to date for optimal micro-aggregation, and so the usage of heuristic methods is necessary. A heuristic algorithm, based on the notion of importance partitioning, is proposed and it is shown that compared with other micro-aggregation heuristics achieves improved performance.
Semantics and expressiveness of ordered SOS
Authors: MohammadReza Mousavi, Iain Phillips, Michel A. Reniers, Irek Ulidowski
Venue: Information and Computation (2009)

Structured Operational Semantics (SOS) is a popular method for defining semantics by means of transition rules. An important feature of SOS rules is negative premises, which are crucial in the definitions of such phenomena as priority mechanisms and time-outs. However, the inclusion of negative premises in SOS rules also introduces doubts as to the preferred meaning of SOS specifications. Orderings on SOS rules were proposed by Phillips and Ulidowski as an alternative to negative premises. Apart from the definition of the semantics of positive GSOS rules with orderings, the meaning of more general types of SOS rules with orderings has not been studied hitherto. This paper presents several candidates for the meaning of general SOS rules with orderings and discusses their conformance to our intuition for such rules. We take two general frameworks (rule formats) for SOS with negative premises and SOS with orderings, and present semantics-preserving translations between them with respect to our preferred notion of semantics. Thanks to our semantics-preserving translation, we take existing congruence meta-results for strong bisimilarity from the setting of SOS with negative premises into the setting of SOS with orderings. We further compare the expressiveness of rule formats for SOS with orderings and SOS with negative premises. The paper contains also many examples that illustrate the benefits of SOS with orderings and the properties of the presented definitions of meaning.
A Necessary Condition for Gauss Period Normal Bases to Be the Same Normal Basis
Authors: Yasuyuki Nogami, Ryo Namba, Yoshitaka Morikawa
Venue: IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences (2008)

This paper shows a necessary condition for type–<k,m> and <k',m> Gauss period normal bases in Fpm to be the same normal basis by using their traces.
Multiparadigm programming in Scala: tutorial presentation
Authors: H. Conrad Cunningham, James C. Church
Venue: Journal of Computing Sciences in Colleges (2009)

This tutorial introduces the new programming language Scala [2,3,4] being developed by Martin Odersky and his team at EPFL in Switzerland. Although Scala arose from the academic research community, it has generated considerable interest in the practitioner community as a possible replacement for Java in enterprise software development. (Odersky was one of the designers of the generic type features added to Java 5.)