ppxscal/embedding_network huggingface dataset:
Combined intra- and inter-domain traffic engineering using hot-potato aware link weights optimization
Authors: Simon Balon, Guy Leduc
Venue: Proceedings of the 2008 ACM SIGMETRICS international conference on Measurement and modeling of computer systems (2008)

A well-known approach to intradomain traffic engineering consists in finding the set of link weights that minimizes a network-wide objective function for a given intradomain traffic matrix. This approach is inadequate because it ignores a potential impact on interdomain routing due to hot-potato routing policies. This may result in changes in the intradomain traffic matrix that have not been anticipated by the link weights optimizer, possibly leading to degraded network performance. We propose a BGP-aware link weights optimization method that takes these hot-potato effects into account. This method uses the interdomain traffic matrix and other available BGP data, to extend the intradomain topology with external virtual nodes and links, on which all the well-tuned heuristics of a classical link weights optimizer can be applied. Our method can also optimize the traffic on the interdomain peering links.
Integrated Heterogeneous Multi-Robot System for Collaborative Navigation
Authors: Qining Wang, Guangming Xie, Long Wang, Ming Wu
Venue: Proceedings of the 2007 Frontiers in the Convergence of Bioscience and Information Technologies (2007)

In this paper, we present an integrated heterogeneous multi-robot system that considers the problem of how heterogeneous autonomous robots, including wheeled robots and four-legged robots, which are different both in hardware and software, can collaborate to navigate in an unknown corridor environment. The navigation tasks involve detecting environment features, self-localizing, performing the planned navigation actions. On the one hand, a timevariable limit cycle based method is created to perform real-time obstacle avoidance. On the other hand, we propose a dynamic reference object based collaborative approach for self localization. Satisfactory experimental results are obtained in real robot experiments.
Efficient finite element analysis by graph-theoretical force method; triangular and rectangular plate bending elements
Authors: A. Kaveh, K. Koohestani
Venue: Finite Elements in Analysis and Design (2008)

The calculation of null basis for equilibrium matrix is the main part of finite elements analysis via force method. For an optimal analysis, the selected null basis matrices should be sparse and banded corresponding to sparse, banded and well-conditioned flexibility matrices. There are many algorithms for the formation of null bases among which the algebraic methods benefit from the generality. However, the efficiency of these methods is highly dependent on the size of problems, and their computational times are very high for such problems. In this paper, a graph-theoretical method is presented for the formation of sparse, banded and highly accurate null basis matrices for finite element models with triangular and rectangular plate bending elements. These bases are generated much faster than those obtained by the algebraic methods. The efficiency of the present method is illustrated through some examples.
A polynomial-time algorithm for deciding equivalence of normed context-free processes
Authors: Y. Hirshfeld
Venue: Proceedings of the 35th Annual Symposium on Foundations of Computer Science (1994)

A polynomial-time procedure is presented for deciding bisimilarity of normed context-free processes. It follows as a corollary that language equivalence of simple context-free grammars is decidable in polynomial time.
UMC-Scan Test Methodology: Exploiting the Maximum Freedom of Multicasting
Authors: Chao-Wen Tzeng, Shi-Yu Huang
Venue: IEEE Design Test (2008)

This article presents a universal-multicasting scan architecture for test compression. By universal multicasting, the authors mean that a specific test pattern can be multicast to a set of any desired scan chains as long as they are compatible. It does require the addition of some extra control bits padded to the compressed test patterns. However, by incorporating techniques such as control pattern encoding, skipping, and partial data reuse, the authors demonstrate that the control overhead can be reduced to a modest level. This method improves the test compression ratio substantially over the recent software-defined multicasting methodology, most notably the segmented addressable scan (SAS). Experimental results indicate that up to 51x test compression ratio in both test data volume and test time can be achieved for a real design with a 1.3% care bit ratio in the test set.
Model Based Development of Quality-Aware Software Services
Authors: Miguel A. de Miguel, Philippe Massonet, Juan P. Silva, Javier Briones
Venue: Proceedings of the 2008 11th IEEE Symposium on Object Oriented Real-Time Distributed Computing (2008)

Modelling languages and development frameworks give support for functional and structural description of software architectures. But quality-aware applications require languages which allow expressing QoS as a first-class concept during architecture design and service composition, and to extend existing tools and infrastructures adding support for modelling, evaluating, managing and monitoring QoS aspects. In addition to its functional behaviour and internal structure, the developer of each service must consider the fulfilment of its quality requirements. If the service is flexible, the output quality depends both on input quality and available resources (e.g., amounts of CPU execution time and memory). From the software engineering point of view, modelling of quality-aware requirements and architectures require modelling support for the description of quality concepts, support for the analysis of quality properties (e.g. model checking and consistencies of quality constraints, assembly of quality), tool support for the transition from quality requirements to quality-aware architectures, and from quality-aware architecture to service run-time infrastructures. Quality management in run-time service infrastructures must give support for handling quality concepts dynamically. QoS-aware modeling frameworks and QoS-aware runtime management infrastructures require a common evolution to get their integration.
Implicitly heterogeneous multi-stage programming
Authors: Jason Eckhardt, Roumen Kaiabachev, Emir Pasalic, Kedar Swadi, Walid Taha
Venue: New Generation Computing (2007)

Previous work on semantics-based multi-stage programming (MSP) language design focused on homogeneous designs, where the generating and the generated languages are the same. Homogeneous designs simply add a hygienic quasi-quotation and evaluation mechanism to a base language. An apparent disadvantage of this approach is that the programmer is bound to both the expressivity and performance characteristics of the base language. This paper proposes a practical means to avoid this by providing specialized translations from subsets of the base language to different target languages. This approach preserves the homogeneous "look" of multi-stage programs, and, more importantly, the static guarantees about the generated code. In addition, compared to an explicitly heterogeneous approach, it promotes reuse of generator source code and systematic exploration of the performance characteristics of the target languages. To illustrate the proposed approach, we design and implement a translation to a subset of C suitable for numerical computation, and show that it preserves static typing. The translation is implemented, and evaluated with several benchmarks. The implementation is available in the online distribution of MetaOCaml.
Two Practical Considerations of Beacon Deployment for Ultrasound-Based Indoor Localization Systems
Authors: Chun-Chieh Hsiao, Polly Huang
Venue: Proceedings of the 2008 IEEE International Conference on Sensor Networks, Ubiquitous, and Trustworthy Computing (sutc 2008) (2008)

In this paper, two practical considerations of beacon deployment for ultrasound-based indoor localization systems are presented. In an indoor environment, beacons are deployed incrementally on the ceiling in order to localize the listeners in between the ceiling and the floor. We first propose a water-drop shaped radio model for the beacon to replace commonly assumed spherical radio model in order to provide true coverage of the listeners. Obstacles in the indoor environment are then considered to take into account the line-of-sight restrictions and thus to enable practical beacon deployment. Although when taking into these two considerations, the number of deployed beacons required tends to be high, it would otherwise be impossible to provide true coverage of the listeners in the indoor environment utilizing ultrasound-based localization.
PT-Scotch: A tool for efficient parallel graph ordering
Authors: C. Chevalier, F. Pellegrini
Venue: Parallel Computing (2008)

The parallel ordering of large graphs is a difficult problem, because on the one hand minimum degree algorithms do not parallelize well, and on the other hand the obtainment of high quality orderings with the nested dissection algorithm requires efficient graph bipartitioning heuristics, the best sequential implementations of which are also hard to parallelize. This paper presents a set of algorithms, implemented in the PT-Scotch software package, which allows one to order large graphs in parallel, yielding orderings the quality of which is only slightly worse than the one of state-of-the-art sequential algorithms. Our implementation uses the classical nested dissection approach but relies on several novel features to solve the parallel graph bipartitioning problem. Thanks to these improvements, PT-Scotch produces consistently better orderings than ParMeTiS on large numbers of processors.
Caml trading – experiences with functional programming on wall street
Authors: Yaron Minsky, Stephen Weeks
Venue: Journal of Functional Programming (2008)

Jane Street Capital is a successful proprietary trading company that uses OCaml as its primary development language. We have over twenty OCaml programmers and hundreds of thousands of lines of OCaml code. We use OCaml for a wide range of tasks: critical trading systems, quantitative research, systems software, and system administration. We value OCaml because it allows us to rapidly produce readable, correct, efficient code to solve complex problems, and to change that code quickly to adapt to a changing world. We believe that using OCaml gives us a significant advantage over competitors that use languages like VB, Perl, C++, C#, or Java. It also makes finding and hiring high-quality software developers easier than with mainstream languages. We have invested deeply in OCaml and intend to use OCaml and grow our team of functional programmers for the foreseeable future.
An upwind-mixed method on changing meshes for two-phase miscible flow in porous media
Authors: Huailing Song, Yirang Yuan
Venue: Applied Numerical Mathematics (2008)

Two-phase miscible flow in porous media is governed by a system of nonlinear partial differential equations. In this paper, the upwind-mixed method on dynamically changing meshes is presented for the problem in two dimensions. The pressure is approximated by a mixed finite element method and the concentration by a method which upwinds the convection and incorporates diffusion using an expanded mixed finite element method. The method developed is shown to obtain almost optimal rate error estimate. When the method is modified we can obtain the optimal rate error estimate that is well known for static meshes. The modification of the scheme is the construction of a linear approximation to the solution, which is used in projecting the solution from one mesh to another. Finally, numerical experiments are given.
Semi-empirical model for longitudinal piezoresistive sensitivity of microcantilevers
Authors: Maryna Lishchynska, Thierry Leıchlé, Liviu Nicu
Venue: Microelectronic Engineering (2008)

Various microsystems applications incorporate piezoresistive sensing elements employed to translate mechanical stress into electrical readout. The piezoresistive sensitivity of such devices is of fundamental importance as it defines the range of detectable deflection or force change. Availability of closed-form analytical models is the most efficient means for fast and reliable MEMS structural design and optimization. This work presents a closed-form model of piezoresistive sensitivity for micromachined cantilevers working in longitudinal deformation mode.
Evaluating the contributions of video representation for a life oral history collection
Authors: Michael G. Christel, Michael H. Frisch
Venue: Proceedings of the 8th ACM/IEEE-CS joint conference on Digital libraries (2008)

A digital video library of over 900 hours of video and 18000 stories from The HistoryMakers is used to investigate the role of motion video for users of recorded life oral histories. Stories in the library are presented in one of two ways in two within-subjects experiments: either as audio accompanied by a single still photographic image per story, or as the same audio within a motion video of the interviewee speaking. Twenty-four participants given a treasure-hunt fact-finding task, i.e., very directed search, showed no significant preference for either the still or video treatment, and no difference in task performance. Fourteen participants in a second study worked on an exploratory task in the same within-subjects experimental framework, and showed a significant preference for video. For exploratory work, video has a positive effect on user satisfaction. Implications for use of video in collecting and accessing recorded life oral histories, in student assignments and more generally, are discussed, along with reflections on long term user studies to complement the ones presented here.
Early containment of worms using dummy addresses and connection trace back
Authors: Taro Inaba, Nobutaka Kawaguchi, Shinya Tahara, Hiroshi Shigeno, Ken-ichi Okada
Venue: Proceedings of the 13th International Conference on Parallel and Distributed Systems - Volume 01 (2007)

Most of existing network worms have used address scanning to find vulnerable hosts. Recently, however, worms with more effective propagation strategies have emerged. Among the worms, we focus on the worms that exploit address lists obtained from infected hosts to find other vulnerable hosts effectively. In this paper, we propose a method to detect and contain such worms that try to infect all hosts in an enterprise network. In our method, a detection system inserts some dummy addresses into the address lists of hosts in the network. Then, the system detects the existence of worms when a host tries to open a connection to a dummy address, and then traces back the connection logs to find potentially infected hosts and removes them from the network. Computer simulation results showed our method detected and contained worms with less than 1% infected hosts and less than 5% removed hosts.
Organizational competence for harnessing IT: A case study
Authors: Gurpreet Dhillon
Venue: Information and Management (2008)

In spite of decades of discussion and research into the benefits of the use of IT in the organization, it has been difficult to prove a positive gain. Literature on IT management has reported more cases of failed implementations than of success. We believed that developing organizational competencies both helped in harnessing IT and also in gaining competitive advantage. Conceptual schema for developing this was based on the theory of strategic competence, which formed the basis of our work. We undertook a case study to prove this. Findings suggested that three broad categories of competence were necessary for harnessing IT. A number of facilitating competencies were also found and are presented.
Code tracking algorithms for mitigating multipath effects in fading channels for satellite-based positioning
Authors: Mohammad Zahidul H. Bhuiyan, Elena Simona Lohan, Markku Renfors
Venue: EURASIP Journal on Advances in Signal Processing (2008)

The ever-increasing public interest in location and positioning services has originated a demand for higher performance global navigation satellite systems (GNSSs). In order to achieve this incremental performance, the estimation of line-of-sight (LOS) delay with high accuracy is a prerequisite for all GNSSs. The delay lock loops (DLLs) and their enhanced variants (i.e., feedback code tracking loops) are the structures of choice for the commercial GNSS receivers, but their performance in severe multipath scenarios is still rather limited. In addition, the new satellite positioning system proposals specify the use of a new modulation, the binary offset carrier (BOC) modulation, which triggers a new challenge in the code tracking stage. Therefore, in order to meet this emerging challenge and to improve the accuracy of the delay estimation in severe multipath scenarios, this paper analyzes feedback as well as feedforward code tracking algorithms and proposes the peak tracking (PT) methods, which are combinations of both feedback and feedforward structures and utilize the inherent advantages of both structures. We propose and analyze here two variants of PT algorithm: PT with second-order differentiation (Diff2), and PT with Teager Kaiser (TK) operator, which will be denoted herein as PT(Diff2) and PT(TK), respectively. In addition to the proposal of the PT methods, the authors propose also an improved early-late-slope (IELS) multipath elimination technique which is shown to provide very good mean-time-to-lose-lock (MTLL) performance. An implementation of a noncoherent multipath estimating delay locked loop (MEDLL) structure is also presented. We also incorporate here an extensive review of the existing feedback and feedforward delay estimation algorithms for direct sequence code division multiple access (DS-CDMA) signals in satellite fading channels, by taking into account the impact of binary phase shift keying (BPSK) as well as the newly proposed BOC modulation, more specifically, sine-BOC(1,1) (SinBOC(1,1)), selected for Galileo open service (OS) signal. The state-of-art algorithms are compared, via simulations, with the proposed algorithms. The main focus in the performance comparison of the algorithms is on the closely spaced multipath scenario, since this situation is the most challenging for estimating LOS component with high accuracy in positioning applications.
The relationship between task structure and collaborative group interactions in a synchronous peer interaction collaborative learning environment for a course of Physics
Authors: Sarantos Psycharis
Venue: Education and Information Technologies (2008)

Although collaborative group work is used by many instructors as a useful educational tool, there is much room for research on how learning actually occurs within collaborative learning environments. This paper attempts to explore the relationship(if any) between task structure and collaborative group interactions in a synchronous peer interaction collaborative learning environment. For this reason, we used the Cmap during a Physics course for Grade 12 students. This paper compares two groups of students, one studying concept maps with single answer task, and the other studying concept maps with variable answer task. The aim of the study presented in this article is to also investigate the influence of task structure on students' interactivity according to certain indicators and cognitive performance.
Incompleteness of exponential system in the weighted Banach space
Authors: Xiangdong Yang
Venue: Journal of Approximation Theory (2008)

We take a new approach to obtain necessary and sufficient condition for the incompleteness of exponential system in C"@a, where C"@a is the weighted Banach space of complex continuous functions f defined on the real axis R with f(t)exp(-@a(t)) vanishing at infinity, in the uniform norm.
Are your votes really counted?: testing the security of real-world electronic voting systems
Authors: Davide Balzarotti, Greg Banks, Marco Cova, Viktoria Felmetsger, Richard Kemmerer, William Robertson, Fredrik Valeur, Giovanni Vigna
Venue: Proceedings of the 2008 international symposium on Software testing and analysis (2008)

Electronic voting systems play a critical role in today's democratic societies, as they are responsible for recording and counting the citizens' votes. Unfortunately, there is an alarming number of reports describing the malfunctioning of these systems, suggesting that their quality is not up to the task. Recently, there has been a focus on the security testing of voting systems to determine if they can be compromised in order to control the results of an election. We have participated in two large-scale projects, sponsored by the Secretaries of State of California and Ohio, whose respective goals were to perform the security testing of the electronic voting systems used in those two states. The testing process identified major flaws in all the systems analyzed, and resulted in substantial changes in the voting procedures of both states. In this paper, we describe the testing methodology that we used in testing two real-world electronic voting systems, the findings of our analysis, and the lessons we learned.
Winning strategies for hexagonal polyomino achievement
Authors: Kazumine Inagaki, Akihiro Matsuura
Venue: Proceedings of the 12th WSEAS International Conference on Applied Mathematics (2007)

In polyomino achievement games, two players alternately mark the cells of a tessellation and try to achieve a given polyomino. In [2], Bode and Harborth investigated polyomino achievement games for the hexagonal tessellation and determined all but five polyominoes with at most five cells whether they are achieved by the first player. In this paper, we show winning strategies for three hexagonal polyominoes with five cells called Y, Z, and C, which were left unsolved in [2].
Can Learning Languages Help You Better Understand Science and Technology?
Authors: Philip Yaffe
Venue: Ubiquity (2008)

"I was 24 years old when I first began thinking and speaking in a foreign language. It was like being released from prison. I saw my cell door swinging open and my mind flying free. That was over 40 years ago, but the picture is as fresh now as if it had just happened."
MidFusion: An adaptive middleware for information fusion in sensor network applications
Authors: Hitha Alex, Mohan Kumar, Behrooz Shirazi
Venue: Information Fusion (2008)

Applications and services are increasingly dependent on networks of smart sensors embedded in the environment to constantly sense and react to events. In a typical sensor network application, information is collected from a large number of distributed and heterogeneous sensor nodes. Information fusion in such applications is a challenging research issue due to the dynamicity, heterogeneity, and resource limitations of sensor networks. We present MidFusion, an adaptive middleware architecture to facilitate information fusion in sensor network applications. MidFusion discovers and selects the best set of sensors or sensor agents on behalf of applications (transparently), depending on the quality of service (QoS) guarantees and the cost of information acquisition. We also provide the theoretical foundation for MidFusion to select the best set of sensors using the principles of Bayesian and Decision theories. A sensor selection algorithm (SSA) for selecting the best set of sensors is presented in this paper. Our theoretical findings are validated through simulation of the SSA algorithm on an example scenario.