ppxscal/embedding_network huggingface dataset:
Back to the future: towards a theory of timed regular languages
Authors: R. Alur
Venue: Proceedings of the 33rd Annual Symposium on Foundations of Computer Science (1992)

The authors introduce two-way timed automata-timed automata that can move back and forth while reading a timed word. Two-wayness in its unrestricted form leads, like nondeterminism, to the undecidability of language inclusion. However, if they restrict the number of times an input symbol may be revisited, then two-wayness is both harmless and desirable. The authors show that the resulting class of bounded two-way deterministic timed automata is closed under all boolean operations, has decidable (PSPACE-complete) emptiness and inclusion problems, and subsumes all decidable real-time logics we know. They obtain a strict hierarchy of real-time properties: deterministic timed automata can accept more languages as the bound on the number of times an input symbol may be revisited is increased. This hierarchy is also enforced by the number of alternations between past and future operators in temporal logic. The combination of the results leads to a decision procedure for a real-time logic with past operators.
Social selected learning content out of web lectures
Authors: Markus Ketterl, Johannes Emden, Jörg Brunstein
Venue: Proceedings of the nineteenth ACM conference on Hypertext and hypermedia (2008)

Virtpresenter is a system for recording lectures and for re-using recorded contents in other didactic scenarios. Here we demonstrate how the interaction of earlier visitors in form of footprints can be used for extracting relevant passages in time based media. We illustrate how to extract online web lecture snippets for enriching static contents of a course wiki page or student blogs.
Unsupervised rank aggregation with distance-based models
Authors: Alexandre Klementiev, Dan Roth, Kevin Small
Venue: Proceedings of the 25th international conference on Machine learning (2008)

The need to meaningfully combine sets of rankings often comes up when one deals with ranked data. Although a number of heuristic and supervised learning approaches to rank aggregation exist, they require domain knowledge or supervised ranked data, both of which are expensive to acquire. In order to address these limitations, we propose a mathematical and algorithmic framework for learning to aggregate (partial) rankings without supervision. We instantiate the framework for the cases of combining permutations and combining top-k lists, and propose a novel metric for the latter. Experiments in both scenarios demonstrate the effectiveness of the proposed formalism.
Scalable molecular dynamics with NAMD on the IBM Blue Gene/L system
Authors: S. Kumar, C. Huang, G. Zheng, E. Bohm, A. Bhatele, J. C. Phillips, H. Yu, L. V. Kalé
Venue: IBM Journal of Research and Development (2008)

NAMD (nanoscale molecular dynamics) is a production molecular dynamics (MD) application for biomolecular simulations that include assemblages of proteins, cell membranes, and water molecules. In a biomolecular simulation, the problem size is fixed and a large number of iterations must be executed in order to understand interesting biological phenomena. Hence, we need MD applications to scale to thousands of processors, even though the individual timestep on one processor is quite small. NAMD has demonstrated its performance on several parallel computer architectures. In this paper, we present various compiler optimization techniques that use single-instruction, multiple-data (SIMD) instructions to obtain good sequential performance with NAMD on the embedded IBM PowerPC® 440 processor core. We also present several techniques to scale the NAMD application to 20,480 nodes of the IBM Blue Gene/L™ (BG/L) system. These techniques include topology-specific optimizations to localize communication, new messaging protocols that are optimized for the BG/L torus, topology-aware load balancing, and overlap of computation and communication. We also present performance results of various molecular systems with sizes ranging from 5,570 to 327,506 atoms.
Estimating cardinality distributions in network traffic: extended abstract
Authors: Aiyou Chen, Li Li, Jin Cao
Venue: Proceedings of the 2008 ACM SIGMETRICS international conference on Measurement and modeling of computer systems (2008)

Information on network host connectivity patterns are important for network monitoring and traffic engineering. In this paper, an efficient streaming algorithm is proposed to estimate cardinality distributions including connectivity distributions, e.g. percent of hosts with any given number of distinct communicating peers or flows.
Proposing SQL statement coverage metrics
Authors: Ben Smith, Yonghee Shin, Laurie Williams
Venue: Proceedings of the fourth international workshop on Software engineering for secure systems (2008)

An increasing number of cyber attacks are occurring at the application layer when attackers use malicious input. These input validation vulnerabilities can be exploited by (among others) SQL injection, cross site scripting, and buffer overflow attacks. Statement coverage and similar test adequacy metrics have historically been used to assess the level of functional and unit testing which has been performed on an application. However, these currently-available metrics do not highlight how well the system protects itself through validation. In this paper, we propose two SQL injection input validation testing adequacy metrics: target statement coverage and input variable coverage. A test suite which satisfies both adequacy criteria can be leveraged as a solid foundation for input validation scanning with a blacklist. To determine whether it is feasible to calculate values for our two metrics, we perform a case study on a web healthcare application and discuss some issues in implementation we have encountered. We find that the web healthcare application scored 96.7% target statement coverage and 98.5% input variable coverage.
Platform-based software design flow for heterogeneous MPSoC
Authors: Katalin Popovici, Xavier Guerin, Frederic Rousseau, Pier Stanislao Paolucci, Ahmed Amine Jerraya
Venue: ACM Transactions on Embedded Computing Systems (TECS) (2008)

Current multimedia applications demand complex heterogeneous multiprocessor architectures with specific communication infrastructure in order to achieve the required performances. Programming these architectures usually results in writing separate low-level code for the different processors (DSP, microcontroller), implying late global validation of the overall application with the hardware platform. We propose a platform-based software design flow able to efficiently use the resources of the architecture and allowing easy experimentation of several mappings of the application onto the platform resources. We use a high-level environment to capture both application and architecture initial representations. An executable software stack is generated automatically for each processor from the initial model. The software generation and validation is performed gradually corresponding to different software abstraction levels. Specific software development platforms (abstract models of the architecture) are generated and used to allow debugging of the different software components with explicit hardware-software interaction. We applied this approach on a multimedia platform, involving a high performance DSP and a RISC processor, to explore communication architecture and generate an efficient executable code for a multimedia application. Based on automatic tools, the proposed flow increases productivity and preserves design quality.
Cybercivics: a novel approach to reaching k-12 students with the social relevance of computer science
Authors: Jim Owens, Jeanna Matthews
Venue: ACM SIGCSE Bulletin (2008)

This paper describes CyberCivics, a novel approach to computer science outreach that integrates hands-on computing experiences with the study of contemporary social and political issues. We provide details of one such curriculum, focused on electronic voting, that we used with a high school AP Government course in Spring 2007. We describe our experience with this curriculum and how it enabled us to reach a larger, more diverse and more academically prepared group of students than prior outreach efforts targeted directly at computing courses. We also suggest a number of alternative approaches to outreach based on the CyberCivics idea.
POSIX and the Verification Grand Challenge: A Roadmap
Authors: Leo Freitas, Jim Woodcock, Andrew Butterfield
Venue: Proceedings of the 13th IEEE International Conference on on Engineering of Complex Computer Systems (2008)

We present a research roadmap for the second pilot project in the Verified Software Grand Challenge on formally verified POSIX file stores. The work is inspired by the requirements for NASA’s forthcoming Mars Rover missions. The roadmap describes an integrated and comprehensive body of work, including current work, as well as further opportunities for collaboration.
The Effects of Mobility and Redundancy on Wireless Video Streaming over MANETs
Authors: Lei Chen, Chung-Wei Lee
Venue: Proceedings of the 22nd International Conference on Advanced Information Networking and Applications - Workshops (2008)

This study examines the extended use of different coding schemes (Scalable vs. Multiple Description or MD) in different video formats (MPEG vs. Motion JPEG or MJPEG) in a Mobile Ad Hoc Network (MANET) environment and proposes a set of redundancy solutions at different coding levels. Simulations and analysis demonstrate and explain the relationship among the coding schemes, video formats, level and amount of redundancy, mobility of mobile devices, CPU load and battery life and frame loss rate at the receiver side. Finally, two practical scenarios are used to illustrate these findings and proposed solutions.
Discovering correlated spatio-temporal changes in evolving graphs
Authors: Jeffrey Chan, James Bailey, Christopher Leckie
Venue: Knowledge and Information Systems (2008)

Graphs provide powerful abstractions of relational data, and are widely used in fields such as network management, web page analysis and sociology. While many graph representations of data describe dynamic and time evolving relationships, most graph mining work treats graphs as static entities. Our focus in this paper is to discover regions of a graph that are evolving in a similar manner. To discover regions of correlated spatio-temporal change in graphs, we propose an algorithm called cSTAG. Whereas most clustering techniques are designed to find clusters that optimise a single distance measure, cSTAG addresses the problem of finding clusters that optimise both temporal and spatial distance measures simultaneously. We show the effectiveness of cSTAG using a quantitative analysis of accuracy on synthetic data sets, as well as demonstrating its utility on two large, real-life data sets, where one is the routing topology of the Internet, and the other is the dynamic graph of files accessed together on the 1998 World Cup official website.
Powermeeting: gwt-based synchronous groupware
Authors: Weigang Wang
Venue: Proceedings of the nineteenth ACM conference on Hypertext and hypermedia (2008)

The Web has been widely used as a platform for asynchronous collaboration. However, Web based synchronous groupware are still rare, especially those using standard Web browser as front-end. In this demonstration, a groupware system built on GWT and AJAX Push technology will be presented. The system provides a common foundation for developing synchronous groupware applications that consist of a set of groupware tools for various specific collaborative activities. It provides not only a desktop-application like user experience within a browser, but also retains the common Web user experience with link following and backward/forward navigation. The objective of this work is to make synchronous collaboration an integral part of collaboration support on the Web.
FAVE: factor analysis based approach for detecting product line variability from change history
Authors: Kentaro Yoshimura, Fumio Narisawa, Koji Hashimoto, Tohru Kikuno
Venue: Proceedings of the 2008 international working conference on Mining software repositories (2008)

This paper describes a novel approach to detect variability in a software product line from its change history such that software changes are converted to vectors and a factor analysis is applied. To show the applicability of our approach, we conducted experimental applications using a software repository of automotive engine control software. As a result of the experiments, variability is detected from the change history of products.
Translating owl and semantic web rules into prolog: Moving toward description logic programs
Authors: Ken Samuel, Leo Obrst, Suzette Stoutenberg, Karen Fox, Paul Franklin, Adrian Johnson, Ken Laskey, Deborah Nichols, Steve Lopez, Jason Peterson
Venue: Theory and Practice of Logic Programming (2008)

We are researching the interaction between the rule and the ontology layers of the Semantic Web, by comparing two options: 1) using OWL and its rule extension SWRL to develop an integrated ontology/rule language, and 2) layering rules on top of an ontology with RuleML and OWL. Toward this end, we are developing the SWORIER system, which enables efficient automated reasoning on ontologies and rules, by translating all of them into Prolog and adding a set of general rules that properly capture the semantics of OWL. We have also enabled the user to make dynamic changes on the fly, at run time. This work addresses several of the concerns expressed in previous work, such as negation, complementary classes, disjunctive heads, and cardinality, and it discusses alternative approaches for dealing with inconsistencies in the knowledge base. In addition, for efficiency, we implemented techniques called extensionalization, avoiding reanalysis, and code minimization.
Contour line thinning and multigrid generation of raster-based digital elevation models
Authors: Endre Katona
Venue: International Journal of Geographical Information Science (2007)

Thin plate spline interpolation is a widely used approach to generate a digital elevation model (DEM) from contour lines and scattered data. In practice, contour maps are scanned and vectorized, and after resampling in the target grid resolution, interpolation is performed. In this paper we demonstrate the limited accuracy of this process, and propose a high-resolution processing method (without vectorization) that ensures maximum utilization of information in the source data. First, we discuss the mathematical background of thin plate spline interpolation, and explain the multigrid relaxation principle used to speed up convergence. After, we will show why fine tuning is necessary, especially when contour lines and elevation points are processed at the same time. Finally, our own contour thinning method that produces a significant reduction of elevation bias is described.
Measurement of the resonant frequency of nano-scale cantilevers by hard contact readout
Authors: S. Dohn, O. Hansen, A. Boisen
Venue: Microelectronic Engineering (2008)

It is shown that detection of the resonant frequency of a nano-scale cantilever is possible by measuring the time average current flowing from an electrode to the cantilever during hard contact occurring twice every cycle of the cantilever vibration. The electronic detection method is insensitive to unavoidable stray capacitances in the system and provides very high resolution using simple low bandwidth off-chip electronics. Moreover, the detection method does not suffer from the common problem in electronic detection methods, where the strong actuation signals often contaminate the detected signal. The readout method is thereby ideally suited for portable sensor systems.
Scaled memoryless BFGS preconditioned conjugate gradient algorithm for unconstrained optimization
Authors: Neculai Andrei
Venue: Optimization Methods Software (2007)

A scaled memoryless BFGS preconditioned conjugate gradient algorithm for solving unconstrained optimization problems is presented. The basic idea is to combine the scaled memoryless BFGS method and the preconditioning technique in the frame of the conjugate gradient method. The preconditioner, which is also a scaled memoryless BFGS matrix, is reset when the Beale-Powell restart criterion holds. The parameter scaling the gradient is selected as the spectral gradient. In very mild conditions, it is shown that, for strongly convex functions, the algorithm is globally convergent. Computational results for a set consisting of 750 unconstrained optimization test problems show that this new scaled conjugate gradient algorithm substantially outperforms the known conjugate gradient methods including the spectral conjugate gradient by Birgin and Martínez [Birgin, E. and Martínez, J.M., 2001, A spectral conjugate gradient method for unconstrained optimization. Applied Mathematics and Optimization, 43, 117-128], the conjugate gradient by Polak and Ribière [Polak, E. and Ribière, G., 1969, Note sur la convergence de méthodes de directions conjuguées. Revue Francaise Informat. Reserche Opérationnelle, 16, 35-43], as well as the most recent conjugate gradient method with guaranteed descent by Hager and Zhang [Hager, W.W. and Zhang, H., 2005, A new conjugate gradient method with guaranteed descent and an efficient line search. SIAM Journal on Optimization, 16, 170-192; Hager, W.W. and Zhang, H., 2004, CG-DESCENT, A conjugate gradient method with guaranteed descent ACM Transactions on Mathematical Software, 32, 113-137].
Crossing the Digital Divide-Possibilities for Influencing the Private-Sector Business Case
Authors: Helen Maskery
Venue: The Information Society (2007)

The accessible information and communications technologies (ICT) design community has made compelling arguments about the business benefits available to companies who design their products and services to be accessible to people with disabilities. The ICT industry, however, has not embraced accessible design. This article proposes re-branding accessible ICT design as "Anytime, Anywhere, Anyone (AAA) Design." This rebranded approach would shift the focus from one of "pushing" accessible design to one where business would actively "pull" for it.
Exposing the ORM Cache
Authors: Michael Keith, Randy Stafford
Venue: Queue (2008)

In the early 1990s, when object-oriented languages emerged into the mainstream of software development, a noticeable surge in productivity occurred as developers saw new and better ways to create software programs. Although the new and efficient object programming paradigm was hailed and accepted by a growing number of organizations, relational database management systems remained the preferred technology for managing enterprise data. Thus was born ORM (object-relational mapping), out of necessity, and the complex challenge of saving the persistent state of an object environment in a relational database subsequently became known as the object-relational impedance mismatch.
Bipartite labeling of trees with maximum degree three
Authors: C. Paul Bonnington, Jozef Širáň
Venue: Journal of Graph Theory (1999)

Let T = (V, E) be a tree with a properly 2-colored vertex set. A bipartite labeling of T is a bijection &phi;: V ➝ {1, &hellip;, |V|} for which there exists a k such that whenever &phi;(u) &le; k < &phi;(v), then u and v have different colors. The &alpha;-size &alpha;(T) of the tree T is the maximum number of elements in the sets {|&phi;(u) - &phi;(v)|; uv &epsilon; E}, taken over all bipartite labelings &phi; of T. The quantity &alpha;(n) is defined as the minimum of &alpha;(T) over all trees with n vertices. In an earlier article (J Graph Theory 19 (1995), 201215), A. Rosa and the second author proved that 5n-7 &le; &alpha;(n) &le; (5n + 4)-6 for all n &ge; 4; the upper bound is believed to be the asymptotically correct value of (n). In this article, we investigate the &alpha;-size of trees with maximum degree three. Let &alpha;3(n) be the smallest &alpha;-size among all trees with n vertices, each of degree at most three. We prove that &alpha;3(n) &ge; 5n-6 for all n &ge; 12, thus supporting the belief above. This result can be seen as an approximation toward the graceful tree conjectureit shows that every tree on n &ge; 12 vertices and with maximum degree three has "gracesize" at least 5n-6. Using a computer search, we also establish that &alpha;3(n) &ge; n - 2 for all n &le; 17. &copy; 1999 John Wiley Sons, Inc. J Graph Theory 31:715, 1999
Mechanical and electrical bonding between silicon wafer and glass wafer with etched channels containing metal tracks
Authors: S. Brida, S. Metivet, D. Petit, O. Stojanovic
Venue: Microsystem Technologies (2005)

In this paper a novel process to bond and, at the same time, to electrically connect a silicon wafer to a glass wafer is presented. It consists of a low temperature anodic bonding process between silicon and glass by using a glass wafer with etched channels in order to contain metal tracks. The glass-to-silicon anodic bonding process at low temperatures (not exceeding 300&#x00b0;C) assures a strong mechanical link (Berthold et&#x00a0;al. in Transducers 1999, June:7&#x2013;10, 1999). The electrical contacts between the metal pads on the backside of a silicon wafer and the metal pads on the glass wafer are achieved by sintering and diffusion of metals due to a kind of thermo compression bonding. This bonding method permits a high vertical control due to a well-controlled etching of the cavity depth and to the thickness precision of both metallization (pads on silicon wafers and metal tracks on glass wafer). This IC-processing compatible approach opens up the way to a new electrical connection concept keeping, at the same time, a strong mechanical bond between glass and silicon wafers for an easier fabrication of a more complex micro-system.
Analysis of musical rhythm complexity measures in a cultural context
Authors: Eric Thul, Godfried T. Toussaint
Venue: Proceedings of the 2008 C3S2E conference (2008)

Eight measures of musical rhythm complexity are compared to each other using two families of real-world rhythms: subsaharan African timelines and North Indian talas. The complexity measures that are designed to measure syncopation, and that agree with human judgements, also agree with each other across the two families. Thus they may be considered as culturally robust measures, at least for these two families of rhythms. Furthermore, according to these measures the African timelines are more complex than the North Indian talas. On the other hand, the more mathematical measures of complexity are less culturally robust, and suggest that some North Indian talas are more complex, in this sense, than the African timelines.
An Approach to Load Balancing and Network Longevity using Dynamic Adaptive Routing in Wireless Sensor Networks
Authors: R. Sumathi, M. G. Srinivasa, R. Srinivasan
Venue: Proceedings of the 2008 Sixth Annual IEEE International Conference on Pervasive Computing and Communications (2008)

Energy efficiency is the major concern in the design of Wireless Sensor Network (WSN). It is imperative to develop protocols to distribute energy dissipation across nodes and reduces hotspots in the networks. In this paper we introduce Load Balancing Dynamic Adaptive Routing (LBDAR), a reactive protocol to find efficient data routing structure for optimal distribution of load. Rather than finding an optimal path and use it for all communication, the proposed algorithm dynamically finds routers and constitutes energy sufficient routing path from source to sink for each round of communication, by considering two node specific parameters, they are frequency count and residual battery power. Frequency count provides good chance for all the routers to actively participate in forwarding data messages and thus help to distribute the routing load. Router is selected such that it retains some battery power, called Adaptable threshold, which varies with size of sensed data. This prevents the early death of heavily involved nodes due to battery drain off, and hence enhances the network lifetime.