ppxscal/embedding_network huggingface dataset:
A Performance Comparison of Continuous and Discontinuous Finite Element Shallow Water Models
Authors: Ethan J. Kubatko, Shintaro Bunya, Clint Dawson, Joannes J. Westerink, Chris Mirabito
Venue: Journal of Scientific Computing (2009)

We present a comparative study of two finite element shallow water equation (SWE) models: a generalized wave continuity equation based continuous Galerkin (CG) model--an approach used by several existing SWE models--and a recently developed discontinuous Galerkin (DG) model. While DG methods are known to possess a number of favorable properties, such as local mass conservation, one commonly cited disadvantage is the larger number of degrees of freedom associated with the methods, which naturally translates into a greater computational cost compared to CG methods. However, in a series of numerical tests, we demonstrate that the DG SWE model is generally more efficient than the CG model (i) in terms of achieving a specified error level for a given computational cost and (ii) on large-scale parallel machines because of the inherently local structure of the method. Both models are verified on a series of analytic test cases and validated on a field-scale application.
Sources and nature of secondary school teachers' education in computer-related ergonomics
Authors: Sara Dockrell, Enda Fallon, Martina Kelly, Rose Galvin
Venue: Computers Education (2009)

Teachers' knowledge of computer-related ergonomics in education will have an effect on the learning process and the work practices of their students. However little is known about teacher education in this area. The study aimed to investigate the sources and nature of secondary school teachers' education about computer-related ergonomics. It also investigated the use of computers by secondary school children. The study included all secondary schools in the Republic of Ireland. The findings suggest that computers are widely available and are used frequently by students and teachers. However, there is evidence that teachers are not receiving information on computer-related ergonomics. Teachers were generally dissatisfied with this and would welcome information on the subject. The study discusses the implications of the findings and makes recommendations to meet the needs of the teachers.
Computing Elevation Maxima by Searching the Gauss Sphere
Authors: Bei Wang, Herbert Edelsbrunner, Dmitriy Morozov
Venue: Proceedings of the 8th International Symposium on Experimental Algorithms (2009)

The elevation function on a smoothly embedded 2-manifold in ¿3 reflects the multiscale topography of cavities and protrusions as local maxima. The function has been useful in identifying coarse docking configurations for protein pairs. Transporting the concept from the smooth to the piecewise linear category, this paper describes an algorithm for finding all local maxima. While its worst-case running time is the same as of the algorithm used in prior work, its performance in practice is orders of magnitudes superior. We cast light on this improvement by relating the running time to the total absolute Gaussian curvature of the 2-manifold.
Fast track article: Dynamic address autoconfiguration in hybrid ad hoc networks
Authors: Emilio Ancillotti, Raffaele Bruno, Marco Conti, Antonio Pinizzotto
Venue: Pervasive and Mobile Computing (2009)

The use of ad hoc networking technologies is emerging as a viable and cost-effective solution to extend the range of traditional wireless local area networks (WLANs). In these networks, mobile client traffic reaches the access points through multi-hop wireless paths that are established by using an ad hoc routing protocol. However, several technical challenges have to be faced in order to construct such an extended WLAN. For instance, traditional autoconfiguration protocols commonly used in infrastructure-based WLANs, such as DHCP or Zeroconf, are not directly applicable in multi-hop wireless networks. To address this problem, in this paper we propose extensions to DHCP to enable the dynamic allocation of globally routable IPv4 addresses to mobile stations in hybrid ad hoc networks, which transparently integrate conventional wired technologies with wireless ad hoc networking technologies. Some of the attractive features of our solution are its ability to cope with node mobility, the introduction of negligible protocol overheads, and the use of legacy DHCP servers. We have implemented a prototype of our scheme, and tested its functionalities considering various topology layouts, network loads and mobility conditions. The experimental results show that our solution ensures short address configuration delays and low protocol overheads.
Autonomous mobile robot navigation to exit path planning for floor tile room
Authors: J. Sandoval, J. J. Medel
Venue: Proceedings of the 8th WSEAS international conference on Signal processing, robotics and automation (2009)

This paper shows an algorithm for path planning to reach an exit load inside to unknown environment but dimensional conditions bounded and with obstacles avoidance. The algorithm implemented consider to implant into a Pioneer 3-DX with the Arnl tools, so that, the grid-map navigation use two dimensional space; limiting only by floor tiles adjust the algorithm respect to the real environment. It could be seen as a whole where the path plan algorithm achieve a specific path for anywhere position or orientation into two dimensional space defined into the knowledge base; having it as objective, to exit with autonomous decision. It has a set answers and landmark motion with time restrictions. In this case, the first simulation requires knowing the environment, but don't know the random position obstacles. The position reached by sonar sensor with Doppler information, requires the odometer orientation and position into a grid-base with motion on cardinal and intermediate direction as long as the environment permits to follows the desired exit path; in other words, with a plane defined, the autonomous mobile robot move into valid position with specific obstacles set. The strategy represents random paths, step by step, evaluating in each interval the path achieved for the desired goal.
Different physical structures of solutions for a generalized Boussinesq wave equation
Authors: Shaoyong Lai
Venue: Journal of Computational and Applied Mathematics (2009)

A technique based on the reduction of order for solving differential equations is employed to investigate a generalized nonlinear Boussinesq wave equation. The compacton solutions, solitons, solitary pattern solutions, periodic solutions and algebraic travelling wave solutions for the equation are expressed analytically under several circumstances. The qualitative change in the physical structures of the solutions is highlighted.
Managing data
Authors: David Lindley
Venue: Communications of the ACM (2009)

Dealing with terabytes of data is not the monumental task it once was. The difficult part is presenting enormous amounts of information in ways that are most useful to a wide variety of users.
Paraquat sorption on calcium alginate gel beads
Authors: Montserrat Ruiz, Jesus Barron-Zambrano, Vicente Rodilla, Agata Szygula, Ana Maria Sastre
Venue: Proceedings of the 4th WSEAS/IASME international conference on Dynamical systems and control (2008)

Environmental pollution and accidental poisoning by agricultural chemicals have become a major social problem. The use of calcium alginate gel beads to remove paraquat dichloride (1,1'-dimethyl-4,4-bipyridinium dichloride) from wastewater under different batch experimental conditions was investigated. Special attention was paid to the effects of pH and the initial concentration of paraquat. We determined that the sorption of paraquat was pH-dependent and based on isotherm curves; the Langmuir model appeared to fit the sorption better than the Freundlich model. It was found that the rate of sorption of paraquat onto the calcium alginate gel beads increased with pH. In all cases, the maximum possible adsorption occurred in the first 120 min. The pseudo-second-order chemical reaction model appears to provide a good correlation, confirming that the dominant mechanism of calcium alginate gel bead sorption is chemical sorption.
Material-solid modeling of human body: A heterogeneous B-spline based approach
Authors: Ravi M. Warkhedkar, Amba D. Bhatt
Venue: Computer-Aided Design (2009)

Human body is a natural heterogeneous object optimized in its structure and composition by natural processes over years of evolution. In this paper, B-spline solid representation method is extended to represent material composition to develop a heterogeneous model of the human body. Two different approaches, namely surface fairing and surface fit, are used to create a slice by slice model from CT scan data. Both the approaches are compared for different regression parameters. This methodology has the potential to represent internal body details accurately with fewer digital input data,with applications in FEM analysis, freeform-fabrication and tissue engineering.
Improving sensing accuracy in cognitive PANs through modulation of sensing probability
Authors: Vojislav B. Mišić, Jelena Mišić
Venue: Mobile Information Systems (2009)

Cognitive radio technology necessitates accurate and timely sensing of primary users' activity on the chosen set of channels. The simplest selection procedure is a simple random choice of channels to be sensed, but the impact of sensing errors with respect to primary user activity or inactivity differs considerably. In order to improve sensing accuracy and increase the likelihood of finding channels which are free from primary user activity, the selection procedure is modified by assigning different sensing probabilities to active and inactive channels. The paper presents a probabilistic analysis of this policy and investigates the range of values in which the modulation of sensing probability is capable of maintaining an accurate view of the status of the working channel set. We also present a modification of the probability modulation algorithm that allows for even greater reduction of sensing error in a limited range of the duty cycle of primary users' activity. Finally, we give some guidelines as to the optimum application ranges for the original and modified algorithm, respectively.
Utilization of a Reusable File Format for Motional 3D Objects on an Educational System
Authors: Kenji Saito, Keisuke Nakamura, Hajime Saito, Takashi Maeda
Venue: Proceeding of the 2005 conference on Towards Sustainable and Scalable Educational Innovations Informed by the Learning Sciences: Sharing Good Practices of Research, Experimentation and Innovation (2005)

We propose a new file format for motional 3D objects (it's called Acerola3D), and examine the usability of this format on an educational virtual environment. In first parts of this paper, we describe that motional 3D objects are useful in educational virtual environments, but to build such objects into systems requires much effort and time. Then, we easily specify the format that we propose that reduces this problem, and compare this format to existing formats. In section 4, we actually build motional 3D objects into our educational system using Acerola3D file. We describe that Acerola3D has reusability and portability, and may attract learners.
The Network as a Storage Device: Dynamic Routing with Bounded Buffers
Authors: Stanislav Angelov, Sanjeev Khanna, Keshav Kunal
Venue: Algorithmica (2009)

We study dynamic routing in store-and-forward packet networks where each network link has bounded buffer capacity for receiving incoming packets and is capable of transmitting a fixed number of packets per unit of time. At any moment in time, packets are injected at various network nodes with each packet specifying its destination node. The goal is to maximize the throughput, defined as the number of packets delivered to their destinations. In this paper, we make some progress on throughput maximization in various network topologies. Let n and m denote the number of nodes and links in the network, respectively. For line networks, we show that Nearest-to-Go (NTG), a natural distributed greedy algorithm, is $\tilde{O}(\sqrt{n})$-competitive, essentially matching a known $\Omega(\sqrt{n})$lower bound on the performance of any greedy algorithm. We also show that if we allow the online routing algorithm to make centralized decisions, there is a randomized polylog(n)-competitive algorithm for line networks as well as for rooted tree networks, where each packet is destined for the root of the tree. For grid graphs, we show that NTG has a competitive ratio of $\tilde{\Theta}(n^{2/3})$while no greedy algorithm can achieve a ratio better than $\Omega(\sqrt{n})$. Finally, for arbitrary network topologies, we show that NTG is $\tilde{\Theta}(m)$-competitive, improving upon an earlier bound of O(mn).
Enhancement and Registration Schemes for Matching Conjunctival Vasculature
Authors: Simona Crihalmeanu, Arun Ross, Reza Derakhshani
Venue: Proceedings of the Third International Conference on Advances in Biometrics (2009)

Ocular biometrics has made significant strides over the past decade primarily due to the rapid advances in iris recognition. Recent literature has investigated the possibility of using conjunctival vasculature as an added ocular biometric. These patterns, observed on the sclera of the human eye, are especially significant when the iris is off-angle with respect to the acquisition device resulting in the exposure of the scleral surface. In this work, we design enhancement and registration methods to process and match conjunctival vasculature obtained under non-ideal conditions. The goal is to determine if conjunctival vasculature is a viable biometric in an operational environment. Initial results are promising and suggest the need for designing advanced image processing and registration schemes for furthering the utility of this novel biometric. However, we postulate that in an operational environment, conjunctival vasculature has to be used with the iris in a bimodal configuration.
Standardization Research in Information Technology: New Perspectives
Authors: Kai Jakobs, Kai Jakobs
Venue: Premier Reference Source (2007)

Standardization has the potential to shape, expand, and create markets. Information technology has undergone a rapid transformation in the application of standards in practice, and recent developments have augmented the need for the divulgence of supplementary research. Standardization Research in Information Technology: New Perspectives amasses cutting-edge research on the application of standards in the market, covering topics such as corporate standardization, linguistic qualities of international standards, the role of individuals in standardization, and the development, use, application, and influence of information technology in standardization techniques.
Ranking of Brain Tumour Classifiers Using a Bayesian Approach
Authors: Javier Vicente, Juan Miguel García-Gómez, Salvador Tortajada, Alfredo T. Navarro, Franklyn A. Howe, Andrew C. Peet, Margarida Julià-Sapé, Bernardo Celda, Pieter Wesseling, Magí Lluch-Ariet, Montserrat Robles
Venue: Proceedings of the 10th International Work-Conference on Artificial Neural Networks: Part I: Bio-Inspired Systems: Computational and Ambient Intelligence (2009)

This study presents a ranking for classifers using a Bayesian perspective. This ranking framework is able to evaluate the performance of the models to be compared when they are inferred from different sets of data. It also takes into account the performance obtained on samples not used during the training of the classifiers. Besides, this ranking assigns a prior to each model based on a measure of similarity of the training data to a test case. An evaluation consisting of ranking brain tumour classifiers is presented. These multilayer perceptron classifiers are trained with 1H magnetic resonance spectroscopy (MRS) signals following a multiproject multicenter evaluation approach. We demonstrate that such a framework can be effectively applied to the real problem of selecting classifiers for brain tumour classification.
Time constrained VRP: an agent environment-perception model
Authors: Mahdi Zargayouna
Venue: Proceeding of the 2006 conference on ECAI 2006: 17th European Conference on Artificial Intelligence August 29 -- September 1, 2006, Riva del Garda, Italy (2006)

In this paper, we present a multiagent model in which agents have a perception upon their shared environment, a measure is associated to the agents' perception field. We apply the model on the Vehicle Routing Problem with Time Windows (VRPTW). The overall process adopts the general schema of parallel insertion methods and it uses the contracting of perception's field of the vehicle agents as a new distance between them. This new measure expresses the feasibility universe of the vehicles and is used as a criterion of choice between candidates vehicles for the insertion of a customer in their plan. Our approach provides a new method to tackle the Time constrained VRP in which the solving process is focused on the future and constitutes an alternative for handling the dynamic version of the problem.
Acyclic edge coloring of graphs with maximum degree 4
Authors: Manu Basavaraju, L. Sunil Chandran
Venue: Journal of Graph Theory (2009)

An acyclic edge coloring of a graph is a proper edge coloring such that there are no bichromatic cycles. The acyclic chromatic index of a graph is the minimum number k such that there is an acyclic edge coloring using k colors and is denoted by a&prime;(G). It was conjectured by Alon, Sudakov, and Zaks that for any simple and finite graph G, a&prime;(G)&les;&Delta; + 2, where &Delta;=&Delta;(G) denotes the maximum degree of G. We prove the conjecture for connected graphs with &Delta;(G)&les;4, with the additional restriction that m&les;2n-1, where n is the number of vertices and m is the number of edges in G. Note that for any graph G, m&les;2n, when &Delta;(G)&les;4. It follows that for any graph G if &Delta;(G)&les;4, then a&prime;(G)&les;7. &copy; 2009 Wiley Periodicals, Inc. J Graph Theory 61: 192&ndash;209, 2009
A unified approach to scheduling on unrelated parallel machines
Authors: V. S. Anil Kumar, Madhav V. Marathe, Srinivasan Parthasarathy, Aravind Srinivasan
Venue: Journal of the ACM (JACM) (2009)

We develop a single rounding algorithm for scheduling on unrelated parallel machines; this algorithm works well with the known linear programming-, quadratic programming-, and convex programming-relaxations for scheduling to minimize completion time, makespan, and other well-studied objective functions. This algorithm leads to the following applications for the general setting of unrelated parallel machines: (i) a bicriteria algorithm for a schedule whose weighted completion-time and makespan simultaneously exhibit the current-best individual approximations for these criteria; (ii) better-than-two approximation guarantees for scheduling to minimize the Lp norm of the vector of machine-loads, for all 1 < p < &infin;; and (iii) the first constant-factor multicriteria approximation algorithms that can handle the weighted completion-time and any given collection of integer Lp norms. Our algorithm has a natural interpretation as a melding of linear-algebraic and probabilistic approaches. Via this view, it yields a common generalization of rounding theorems due to Karp et al. [1987] and Shmoys & Tardos [1993], and leads to improved approximation algorithms for the problem of scheduling with resource-dependent processing times introduced by Grigoriev et al. [2007].
An intelligent physical layer for cognitive radio networks
Authors: Aveek Dutta, Jeffrey Fifield, Graham Schelle, Dirk Grunwald, Douglas Sicker
Venue: Proceedings of the 4th Annual International Conference on Wireless Internet (2008)

In this paper, we present an intelligent physical layer for cognitive mesh networks. It is well recognized that wireless mesh networks suffer from the inherent property of per hop delay attributed to store and forward routing and channel contention. We show that an intelligent physical layer coupled with efficient traffic engineering and channel allocation mechanism will reduce latency. In this paper, we discuss the evolution of an OFDM receiver, with sufficient software control to aid reconfigurability, capable of receiving and decoding information on different set of subcarriers, and also capable of switching the incoming signals to a different part of the available spectrum on the fly. Equipped with this enhanced receiver we propose a mechanism for wireless worm-hole routing, which employs frequency domain switching between subchannels where each subchannel is defined by a set of subcarriers. The OFDM receiver handles three primitives: transmit, receive and relay rather than just transmit or receive. Instead of a contention based, store and forward routing, a relay oriented physical layer has been proposed to reduce latency. The processing pipeline at an intermediate node no longer involves higher layer processing, and the hardware relays the incoming signal on-the-fly to a different part of the spectrum allowing for a full duplex transmission as the transmitter can relay signals while it is receiving on a different subchannel.
Thread criticality predictors for dynamic performance, power, and resource management in chip multiprocessors
Authors: Abhishek Bhattacharjee, Margaret Martonosi
Venue: Proceedings of the 36th annual international symposium on Computer architecture (2009)

With the shift towards chip multiprocessors (CMPs), exploiting and managing parallelism has become a central problem in computing systems. Many issues of parallelism management boil down to discerning which running threads or processes are critical, or slowest, versus which are non-critical. If one can accurately predict critical threads in a parallel program, then one can respond in a variety of ways. Possibilities include running the critical thread at a faster clock rate, performing load balancing techniques to offload work onto currently non-critical threads, or giving the critical thread more on-chip resources to execute faster. This paper proposes and evaluates simple but effective thread criticality predictors for parallel applications. We show that accurate predictors can be built using counters that are typically already available on-chip. Our predictor, based on memory hierarchy statistics, identifies thread criticality with an average accuracy of 93% across a range of architectures. We also demonstrate two applications of our predictor. First, we show how Intel's Threading Building Blocks (TBB) parallel runtime system can benefit from task stealing techniques that use our criticality predictor to reduce load imbalance. Using criticality prediction to guide TBB's task-stealing decisions improves performance by 13-32% for TBB-based PARSEC benchmarks running on a 32-core CMP. As a second application, criticality prediction guides dynamic energy optimizations in barrier-based applications. By running the predicted critical thread at the full clock rate and frequency-scaling non-critical threads, this approach achieves average energy savings of 15% while negligibly degrading performance for SPLASH-2 and PARSEC benchmarks.