ppxscal/embedding_network huggingface dataset:
2D unstructured mesh generation for oceanic and coastal tidal models from a localized truncation error analysis with complex derivatives
Authors: D. M. Parrish, S. C. Hagen
Venue: International Journal of Computational Fluid Dynamics (2007)

A method for computing target element size for tidal, shallow water flow is developed and demonstrated. The method, Localized truncation error analysis with complex derivatives (LTEA-CD) utilizes localized truncation error estimates of the linearized shallow water momentum equations consisting of complex derivative terms. This application of complex derivatives is the chief way in which the method differs from a similar existing method, LTEA. It is shown that LTEA-CD produces results that are essentially equivalent to those of LTEA (which in turn has been demonstrated to be capable of producing practicable target element sizes) with reduced computational cost. Moreover, LTEA-CD is capable of computing truncation error and corresponding target element sizes at locations up to and including the boundary, whereas LTEA can be applied only on the interior of the model domain. We demonstrate the convergence of solutions over meshes generated with LTEA-CD using an idealized representation of the western North Atlantic Ocean, Caribbean Sea and Gulf of Mexico.
Evaluation of Ordering Methods for DNA Sequence Design Based on Ant Colony System
Authors: Tri Basuki Kurniawan, Noor Khafifah Khalid, Zuwairie Ibrahim, Marzuki Khalid, Martin Middendorf
Venue: Proceedings of the 2008 Second Asia International Conference on Modelling & Simulation (AMS) (2008)

Hybridization between a DNA sequence and its base-pairing complement is crucial in DNA computing to retrieve the information stored in DNA sequences and operate a computation processes. Therefore, much works have focused on designing the DNA sequences for a reliable molecular computation. In this paper, Ant Colony System (ACS) is proposed to solve the DNA sequence design problem. ACS, which is based on Ant Colony Optimization (ACO) is an improvement of Ant System (AS) that uses some agents to obtain the solutions based on the pheromone in their colony. The DNA sequence design problem is modeled by four nodes, representing four DNA bases (A, T, C, and G) using the nearest-neighbor thermodynamic parame-ter’s Watson-Crick base-pair ΔGo37 as distances between one node to other nodes. Seven ordering methods for ACS are presented in this study in order to obtain the best set solution. The performance of each of those methods are compared and evaluated to decide the best ordering method for this application.
SIGABA: Cryptanalysis of the Full Keyspace
Authors: Mark Stamp, Wing On Chan
Venue: Cryptologia (2007)

In this article, we consider an attack on the SIGABA cipher under the assumption that the largest practical keyspace is used. The attack highlights various strengths and weaknesses of SIGABA and provides insight into the inherent level of security provided by the cipher.
Intelligent Navigation of Autonomous Underwater Vehicles for Cage Aquafarm Surveillance
Authors: Jongan Lee, Mootaek Roh, Jinsung Lee, Doheon Lee
Venue: Proceedings of the 2007 Frontiers in the Convergence of Bioscience and Information Technologies (2007)

Cage aquafarm systems need to provide artificial monitoring and control functions to maintain essential environmental factors for the high productivity of marine products. Autonomous underwater vehicles (AUVs), which have been utilized for various ocean applications such as coastal structure inspection and undersea exploration, are emerging as effective candidate tools for aquafarm surveillance due to their capability of broad range navigation. This paper proposes a technique for intelligent navigation of AUVs around cage aquafarms based on the artificial immune technology. We adopt a Clonal Selection Algorithm(CSA) to determine optimal navigation paths surrounding the aquafarms while reducing energy consumption.
FG-MC-CDMA System Performance in Multi-band Channels
Authors: Jingtao Zhang, David W. Matolak
Venue: Proceedings of the Communication Networks and Services Research Conference (2008)

In this paper, we describe a generalized version of multicarrier CDMA (MC-CDMA) that extends to multiple frequency sub-bands or multiple bands. We term this frequency-generalized MC-CDMA (FG-MC-CDMA). This technique can provide more flexibility in selection of data rates and a larger diversity order than comparable schemes, by generalizing MC-CDMA to allow for different spreading factors. We describe the scheme’s principles of operation, and provide analytical and simulation results for its use in multi-band channels. Our results show that FG-MC-CDMA can be an attractive transmission scheme for reliable multi-rate wireless communications.
Using problem frames to model the requirements ofa system for monitoring dangerous goods transportation
Authors: Pietro Colombo, Vieri del Bianco, Luigi Lavazza
Venue: Proceedings of the 3rd international workshop on Applications and advances of problem frames (2008)

The approach to requirements modelling based on problem frames is gaining increasing attention and popularity. This paper reports an experience in the application of problem frames to modelling the requirements of a system for monitoring the transportation of dangerous goods (namely, petrol and other types of fuels) by trucks. The paper shows that in general the main requirements of the system can be modelled by means of problem frames or problem frame compositions. In the considered system, the requirements are deeply affected by the central role played by the database that stores the data collected from trucks. In one case, the presence of the database made it difficult to identify a problem frame, among those available, to describe the user requirements: this resulted in the proposal for a new problem frame. Another consequence of the presence of the database is that several frame compositions are structured according to a sequential pattern, governed by accesses to the database.
Geometric Algebra for Computer Graphics, 1 edition
Authors: John A. Vince
Venue:  (2008)

Geometric algebra (a Clifford Algebra) has been applied to different branches of physics for a long time but is now being adopted by the computer graphics community and is providing exciting new ways of solving 3D geometric problems. John Vince (author of numerous books including Geometry for Computer Graphics and Vector Analysis for Computer Graphics) has tackled this complex subject in his usual inimitable style, and provided an accessible and very readable introduction. As well as putting geometric algebra into its historical context, John tackles complex numbers and quaternions; the nature of wedge product and geometric product; reflections and rotations (showing how geometric algebra can offer a powerful way of describing orientations of objects and virtual cameras); and how to implement lines, planes, volumes and intersections. Introductory chapters also look at algebraic axioms, vector algebra and geometric conventions and the book closes with a chapter on how the algebra is applied to computer graphics.
On k-coverage in a mostly sleeping sensor network
Authors: Santosh Kumar, Ten H. Lai, József Balogh
Venue: Wireless Networks (2008)

Sensor networks are often desired to last many times longer than the active lifetime of individual sensors. This is usually achieved by putting sensors to sleep for most of their lifetime. On the other hand, event monitoring applications require guaranteed k-coverage of the protected region at all times. As a result, determining the appropriate number of sensors to deploy that achieves both goals simultaneously becomes a challenging problem. In this paper, we consider three kinds of deployments for a sensor network on a unit square--a √n × √n grid, random uniform (for all n points), and Poisson (with density n). In all three deployments, each sensor is active with probability p, independently from the others. Then, we claim that the critical value of the function npπ r2/ log(np) is 1 for the event of k-coverage of every point. We also provide an upper bound on the window of this phase transition. Although the conditions for the three deployments are similar, we obtain sharper bounds for the random deployments than the grid deployment, which occurs due to the boundary condition. In this paper, we also provide corrections to previously published results. Finally, we use simulation to show the usefulness of our analysis in real deployment scenarios.
DSP-based adaptive and self-tuning control of an adjustable speed DC drive system
Authors: Vasile Horga, Alexandru Onea, Mihai Albu
Venue: Proceedings of the 5th WSEAS/IASME International Conference on Systems Theory and Scientific Computation (2005)

The paper presents a solution of self-tuning control applied to a chopper-driven motor system. On that purpose the mathematical model of the plant is firstly delivered. It was preferred an on-line system parameters estimation based on continuous time model. The adaptive and self-tuning algorithms were implemented on a floating-point DSP.
MultiVizArch: multiple graphical layouts for visualizing software architecture
Authors: Amit Prakash Sawant, Naveen Bali
Venue: Crossroads (2008)

This article presents an automated technique for visualizing large software architectures using multiple graphical representations, including multi-dimensional scaling, 2-D grid, and spiral layouts. We describe how our software visualization methods were applied to the Network Appliance operating system known as Data ONTAP 7G (ONTAP). We show how each method can be applied to comprehend a specific aspect of ONTAP. This approach can be used by software engineers, architects, and developers to better understand the architecture of their code.
Personalized active learning for collaborative filtering
Authors: Abhay S. Harpale, Yiming Yang
Venue: Proceedings of the 31st annual international ACM SIGIR conference on Research and development in information retrieval (2008)

Collaborative Filtering (CF) requires user-rated training examples for statistical inference about the preferences of new users. Active learning strategies identify the most informative set of training examples through minimum interactions with the users. Current active learning approaches in CF make an implicit and unrealistic assumption that a user can provide rating for any queried item. This paper introduces a new approach to the problem which does not make such an assumption. We personalize active learning for the user, and query for only those items which the user can provide rating for. We propose an extended form of Bayesian active learning and use the Aspect Model for CF to illustrate and examine the idea. A comparative evaluation of the new method and a well-established baseline method on benchmark datasets shows statistically significant improvements with our method over the performance of the baseline method that is representative for existing approaches which do not take personalization into account.
Improved approximations for multiprocessor scheduling under uncertainty
Authors: Christopher Y. Crutchfield, Zoran Dzunic, Jeremy T. Fineman, David R. Karger, Jacob H. Scott
Venue: Proceedings of the twentieth annual symposium on Parallelism in algorithms and architectures (2008)

This paper presents improved approximation algorithms for the problem of multiprocessor scheduling under uncertainty (SUU), in which the execution of each job may fail probabilistically. This problem is motivated by the increasing use of distributed computing to handle large, computationally intensive tasks. In the SUU problem we are given n unit-length jobs and m machines, a directed acyclic graph G of precedence constraints among jobs, and unrelated failure probabilities qij for each job j when executed on machine i for a single timestep. Our goal is to find a schedule that minimizes the expected makespan. Lin and Rajaraman gave the first approximations for this NP-hard problem for the special cases of independent jobs, precedence constraints forming disjoint chains, and precedence constraints forming trees. In this paper, we present asymptotically better approximation algorithms. In particular, we improve upon the previously best O(log n)-approximation, giving an O(log log(min {m,n}))-approximation in the case of independent jobs. We also give an O(log(n+m) log log(min{m,n}))-approximation algorithm for precedence constraints that form disjoint chains (improving on the previously best O(log(n)log(m) log(n+m) over log log(n+m)-approximation by a (log n/log log n)2 factor when n = m Θ(1)). Our algorithm for precedence constraints forming chains can also be used as a component for precedence constraints forming trees, yielding a similar improvement over the previously best algorithms for trees. Our techniques include reducing SUU to a problem in stochastic scheduling, where machines must process a set of jobs with randomly distributed lengths. We show that our algorithms for (SUU) apply to a standard problem in this setting, giving the first approximation algorithms for preemptive stochastic scheduling on unrelated machines.
On finding approximate supernodes for an efficient block-ILU(k) factorization
Authors: Pascal Hénon, Pierre Ramet, Jean Roman
Venue: Parallel Computing (2008)

Among existing preconditioners, the level-of-fill ILU has been quite popular as a general-purpose technique. Experimental observations have shown that, when coupled with block techniques, these methods can be quite effective in solving realistic problems arising from various applications. In this work, we consider an extension of this kind of method which is suitable for parallel environments. Our method is developed from the framework of high performance sparse direct solvers. The main idea we propose is to define an adaptive blockwise incomplete factorization that is much more accurate (and numerically more robust) than the scalar incomplete factorizations commonly used to precondition iterative solvers. These requirements lead to a robust class of parallel preconditioners based on generalized versions of block ILU techniques.
Powermeeting on common ground: web based synchronous groupware with rich user experience
Authors: Weigang Wang
Venue: Proceedings of the hypertext 2008 workshop on Collaboration and collective intelligence (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. From a technical and social protocol co-evolution perspective, this work examines the Web technical protocol evolution and proposes an AJAX based approach to creating synchronous groupware that may offer a rich user experience. The objective of this work is to make the creation and adoption of such groupware easier, so as to make synchronous collaboration an integral part of collaboration support on the Web. Indirect evidence has been provided to show that this approach offers a practical solution and the objective is achievable.
FuzzyHash: A Secure Biometric Template Protection Technique
Authors: Andrew Teoh Beng Jin, Jaihie Kim
Venue: Proceedings of the 2007 Frontiers in the Convergence of Bioscience and Information Technologies (2007)

Biometrics is likely to provide a new level of security to applications since application users will need to prove their identity when attempting access. Yet if the stored biometric template is compromised then the conventional biometric recognition system is vulnerable to privacy invasion, which is also a permanent loss because the biometric template is not replaceable. We introduce a new technique for protecting the biometric template called FuzzyHashing. It takes inspiration in the cryptographic hashing function, which endows it with properties that are desirable for improved security such as: one-way transformation, confusion, diffusion etc. After an enumeration of the design requirements of FuzzyHashing we demonstrate one of its realizations in the context of face biometrics.
Modified middle point scheme for the elastodynamic frictional contact problem
Authors: Houari B. Khenous
Venue: Proceedings of the 7th WSEAS International Conference on Applied Mathematics (2005)

The purpose of this paper is to present the different time integration scheme used in litterature for the elastodynamic friction contact problem. Each method is detailed and treated in term of energy stability (conservation or dissipation). A modified middle point is employed for treating the problem and to proof the conservation of the system energy. The resulting problem is solved with a Newton method.
A Survey of Context Adaptation in Autonomic Computing
Authors: Cornel Klein, Reiner Schmid, Christian Leuxner, Wassiou Sitou, Bernd Spanfelner
Venue: Proceedings of the Fourth International Conference on Autonomic and Autonomous Systems (2008)

Autonomic Computing (AC) is an emerging paradigm aiming at simplifying the administration of complex computer systems. Efforts required to deploy and maintain complex systems are usually high. Autonomic Computing may help to reduce these efforts by allowing administrators to define abstract policies and then enable systems to configure, optimize and maintain themselves according to the specified policies. Context adaptation can be regarded as an enabling technology for future applications in the field of Autonomic Computing. In this paper we present a survey of past and future secrets of this enabling technology in Autonomic Computing.
A METHOD FOR ONTOLOGY CONFLICT RESOLUTION AND INTEGRATION ON RELATION LEVEL
Authors: Ngoc Thanh Nguyen
Venue: Cybernetics and Systems (2007)

Conflict of ontologies can appear on one of three levels: instance level, concept level and relation level. Conflict on instance level appears when the same instance occurs in different ontologies with different descriptions. Two ontologies are in conflict on concept level if the same concept has different structures in these ontologies. Conflict on relation level refers to different relations between the same two concepts in different ontologies. In this article a method for ontology conflict resolution and integration on relation level is presented. Within this method we present a model for representing ontology conflict and consensus-based algorithms for conflict resolution.
An Efficient Approach for Location Updating in Mobile Ad Hoc Networks
Authors: Sanjay K. Dhurandher, Sudip Misra, Namit Nangia, Nitin Bhardwaj, Pankaj Goyal, Sumit Aggarwal, Mohammad S. Obaidat
Venue: Proceedings of the 41st Annual Simulation Symposium (anss-41 2008) (2008)

In this paper, we consider the problem of location updating in mobile ad-hoc networks (MANETs). We propose a node stability-based location updating approach. In order to optimize the routing, most of the existing routing algorithms use some mechanism for determining the nodes’ neighbours. This information is stored in a table called the Neighbour Table. The updating of the Neighbour Table is referred to as Location Updating. Preliminary set of results show that our proposed algorithm outperforms the typical algorithm used for location updating in existing algorithms.
A fixture design system for networked manufacturing
Authors: Y. G. Kang, Z. Wang, R. Li, C. Jiang
Venue: International Journal of Computer Integrated Manufacturing (2007)

Fixture design is a complex and intuitive process. An efficient fixture design system is essential to cut costs and reduce product lead time. For networked manufacturing, the fixture design system must contain characteristics of rapid configuration designing, three-dimensional (3D) modelling, a completely standardized elements database, and it should be able to transfer information with various other systems. For the requirement of rapid configuration design, based on the analysis of the contents and characteristics of fixture design, a hybrid CBR/KBR (case-based reasoning/knowledge-based reasoning) fixture design method is proposed, with CBR as its core, KBR as its assistant and CBR as the support of case-adaptation process. Using design information, the designer can obtain a satisfactory subset of possible configuration designs of a fixture from the KBR process. Then the designer, using this subset and other information (via FIXCOD system), can obtain a similar design of the fixture from the retrieving case database, and then finally use the CBR adaptation technique to obtain the satisfied design of fixture. Networked information releasing technology is applied to part design in the computer aided design (CAD) system, and a new 3D modelling method is presented, driven by networked parameters. The data on the web are integrated into the CAD system to realize multithreading data exchange between the web information releasing system and the CAD system, which will make the CAD system obtain data from the web. Then networked 3D modelling will be realized by the driving of parameters from the web, and a proved model based on CATIA is provided. The internet and the use of extensible mark-up language (XML) as a file format provide a means for the transfer of information and knowledge between the various computer aided manufacturing (CAM) systems. The system has been implemented using Java and is based on a three-tier browser/server (B/S) architecture. This ensures the platform independent performance of the system.
Next-generation access network architectures for video, voice, interactive gaming, and other emerging applications: challenges and directions
Authors: Ramesh Nagarajan, Sven Ooghe
Venue: Bell Labs Technical Journal (2008)

Internet access was the main service supported in legacy access networks via asynchronous transfer mode (ATM)-based digital subscriber line access multiplexers (DSLAMs) and aggregation networks. The broadband remote access server (BRAS) was the Internet Protocol (IP) edge router, and it provided various services including service routing, Point-to-Point Protocol (PPP) handling, shaping, scheduling, and policy-based controls. This architecture is being increasingly replaced by an Ethernet-based aggregation network with potentially multiple broadband network gateways (BNGs) replacing the single BRAS. The migration to Ethernet-based networks is partly driven by the high bandwidth needs of applications such as video on demand (VoD), IP television (IPTV), and the ability to support these applications at cost-effective points. Other drivers that are emerging to further shape the next generation of access networks are examined in this paper. In particular, we focus closely on emerging video and voice applications and the new challenges and requirements they bring. The set of applications and issues that we consider is by no means comprehensive. They have been selected as they pose some interesting challenges and have significant impact on the access network functionality and architecture. For video traffic, we examine the challenges for providing high video quality, fast response for IPTV channel change, and content distribution. For voice, we examine the challenges of emergency standalone operation. Finally, we examine aspects of quality of service (QoS) management, resource control, and network resiliency mechanisms for these emerging applications. We see that the access network needs to become extremely application aware and dynamic and move beyond the traditional IP layer 2-3 forwarding functions in order to meet these challenges effectively. &copy; 2008 Alcatel-Lucent.