ppxscal/embedding_network huggingface dataset:
A direct comparison between volume and surface tracking methods with a boundary-fitted coordinate transformation and third-order upwinding
Authors: Maria Zacharioudaki, Charalampos Kouris, Yannis Dimakopoulos, John Tsamopoulos
Venue: Journal of Computational Physics (2007)

A Volume Tracking (VT) and a Front Tracking (FT) algorithm are implemented and compared for locating the interface between two immiscible, incompressible, Newtonian fluids in a tube with a periodically varying, circular cross-section. Initially, the fluids are stationary and stratified in an axisymmetric arrangement so that one is around the axis of the tube (core fluid) and the other one surrounds it (annular fluid). A constant pressure gradient sets them in motion. With both VT and FT, a boundary-fitted coordinate transformation is applied and appropriate modifications are made to adopt either method in this geometry. The surface tension force is approximated using the continuous surface force method. All terms appearing in the continuity and momentum equations are approximated using centered finite differences in space and one-sided forward finite differences in time. In each time step, the incompressibility condition is enforced by a transformed Poisson equation, which is linear in pressure. This equation is solved by either direct LU decomposition or a Multigrid iterative solver. When the two fluids have the same density, the former method is about 3.5 times faster, but when they do not, the Multigrid solver is as much as 10 times faster than the LU decomposition. When the interface does not break and the Reynolds number remains small, the accuracy and rates of convergence of VT and FT are comparable. The well-known failure of centered finite differences arises as the Reynolds number increases and leads to non-physical oscillations in the interface and failure of both methods to converge with mesh refinement. These problems are resolved and computations with Reynolds as large as 500 converged by approximating the convective terms in the momentum equations by third-order upwind differences using Lagrangian Polynomials. When the volume of the core fluid or the Weber number decrease, increasing the importance of interfacial tension and leading to breakup of the interface forming a drop of core fluid, the FT method converges faster with mesh refinement than the VT method and upwinding may be required. Finally, examining the generation of spurious currents around a stationary ''bubble'' in the tube for Ohnesorge numbers between 0.1 and 10 it is found that the maximum velocity remains approximately the same in spite mesh refinements when VT is applied, whereas it is of the same order of magnitude for the coarsest mesh and monotonically decreases with mesh refinement when FT is applied.
A Routing Strategy Based on Ant Algorithm for WSN
Authors: Yuhua Liu, Haiyan Zhu, Kaihua Xu, Yongcan Jia
Venue: Proceedings of the Third International Conference on Natural Computation - Volume 05 (2007)

Combined the characteristic of sensor network and the properties of ant algorithm to quickly identify an optimal path, an ant routing algorithm based on deflection angle is proposed. Roulette choosing method is used, combined deflection angle, energy and distance as the elicitation factors, to find an optimal path from source to sink. Aimed at the two conditions of communication and non-communication between artificial ants, simulation and analysis are done separately.
Inter-spike-intervals analysis of AER Poisson-like generator hardware
Authors: A. Linares-Barranco, M. Oster, D. Cascado, G. Jiménez, A. Civit, B. Linares-Barranco
Venue: Neurocomputing (2007)

Address-Event-Representation (AER) is a communication protocol for transferring images between chips, originally developed for bio-inspired image-processing systems. Such systems may consist of a complicated hierarchical structure with many chips that transmit images among them in real time, while performing some processing (for example, convolutions). In developing AER-based systems it is very convenient to have available some means of generating AER streams from on-computer stored images. Rank order coding (ROC) and Poisson rate coding are the extremes of spikes coding. In this paper, we present a pseudo-random hardware method for generating AER streams in real time from a sequence of images stored in a computer's memory. The Kolmogorov-Smirnov test has been applied to quantify that this method follows a Poisson distribution of the spikes. A USB-AER board, developed by our RTCAR group, have been used for the measurements. An example scenario of use under the EU CAVIAR project is presented.
Grid Resource Scheduling with Gossiping Protocols
Authors: Deger Cenk Erdil, Michael J. Lewis
Venue: Proceedings of the Seventh IEEE International Conference on Peer-to-Peer Computing (2007)

Grid resource providers can use gossiping to disseminate their available resource state to remote regions of the grid to attract application load. Pairwise gossiping protocols exchange information about limited subsets of other resources between pairs of potentially remote participants. In epidemic gossiping protocols, the provider disseminates information to multiple neighbors, who in turn forward it to their neighbors, and so on. One important metric for these protocols is their coverage, which characterizes how many and which resources receive the information. Coverage characteristics of epidemic protocols are non-uniform, concentrated within the vicinity of a disseminating node; they can exhibit bi-modal behavior where information either reaches distant nodes or dies out quickly. Pairwise gossiping protocols, on the other hand, provide a more uniform coverage, but it can take longer for the dissemination to reach desired uniformity. In this paper, we study performance characteristics of three gossiping protocols: (1) epidemic gossiping, (2) pairwise gossiping, and (3) adaptive information dissemination (which is based on a form of epidemic gossiping). We report experimental results based on our simulation framework that compare the three protocols in terms of packet overhead and query satisfaction rates. We show that pairwise gossiping protocols work best when resource distribution on the grid is uniform, but that they can be configured to perform well in support of grid scheduling.
An Information Security Strategy for Networkable Devices
Authors: Ilan Oshri, Julia Kotlarsky, Corey Hirsch
Venue: IEEE Security and Privacy (2007)

Networkable Windows-based operating system devices present information security challenges to both vendors and users of such devices. This article highlights some of those threats and offers measures to improve the link between a firm's business strategy, its operational activities, and its information security strategy.
Counting Beans
Authors: David Alan Grier
Venue: Computer (2007)

Our current body politic is looking for a more robust voting mechanism that is secured by technology rather than by the competence and integrity of bean counters.
A link availability-based QoS-aware routing protocol for mobile ad hoc sensor networks
Authors: Ming Yu, Aniket Malvankar, Wei Su, Simon Y. Foo
Venue: Computer Communications (2007)

With more and more wireless devices being mobile, there is a constant challenge to provide reliable and high quality communication services among these devices. In this paper, we propose a link availability-based QoS-aware (LABQ) routing protocol for mobile ad hoc networks based on mobility prediction and link quality measurement, in addition to energy consumption estimate. The goal is to provide highly reliable and better communication links with energy-efficiency. The proposed routing algorithm has been verified by NS-2 simulations. The results have shown that LABQ outperforms existing algorithms by significantly reducing link breakages and thereby reducing the overheads in reconnection and retransmission. It also reduces the average end-to-end delay for data transfer and enhances the lifetime of nodes by making energy-efficient routing decisions.
Xen and the Art of Cluster Scheduling
Authors: Niels Fallenbeck, Hans-Joachim Picht, Matthew Smith, Bernd Freisleben
Venue: Proceedings of the 2nd International Workshop on Virtualization Technology in Distributed Computing (2006)

In shared use clusters, scheduling systems must schedule both serial and parallel jobs in a fair manner, while at the same time optimizing overall cluster efficiency. Since serial and parallel jobs conflict considerably, scheduling both types of jobs concurrently is a difficult task. Two major strategies are in common use: partitioning the cluster (thus avoiding the problem) and reservation combined with backfilling. Both have major drawbacks in overall performance, ease of use and fairness depending on the particular configuration, which can lead to heated debates between the users of the different types of jobs. In this paper, we introduce an approach to create dynamic virtual cluster partitions using para-virtualization techniques, to deal with the conflicts between parallel and serial jobs. The system dynamically adjusts to different types of job loads and offers easy and transparent use and configuration to both users and administrators, without resorting to complicated runtime prediction or backfilling algorithms. A proof-of-concept implementation based on the Sun Grid Engine scheduling system and Xen is presented.
CLDA: Feature Selection for Text Categorization Based on Constrained LDA
Authors: Cui Zifeng, Xu Baowen, Zhang Weifeng, Jiang Dawei, Xu Junling
Venue: Proceedings of the International Conference on Semantic Computing (2007)

Feature selection is a necessary process before pattern classification, machine learning and data mining. Now feature selection is facing challenge in high dimension space, such as text categorization in information retrieval. Linear Discriminant Analysis (LDA) is an excellent dimensionality reduction method which transforms the original data into low-dimensional feature space. However, it changes the original physical features and makes features uninterpretable, which motivates us to select but not transform features by LDA idea of preserving structure information of between-class and within-class for text categorization. In the paper, a new approach of feature selection based on Constrained LDA (CLDA) is proposed, which models feature selection as a search problem in subspace and finds optimal solution subject to some restrictions. Further, CLDA optimization problem is transformed into a process of scoring and sorting of features. Experiments on 20 Newsgroups and Reuters-21578 show that CLDA is consistently better than information gain and chi2-test with lower computational complexity.
Special Feature the Intel 8089: An Integrated I/O Processor
Authors: K. A. El-Ayat
Venue: Computer (1979)

As most mainframe manufacturers have demonstrated, the logical solution to I/O control problems is to deploy intelligent I/O subsystems. Intel's 8089 brings this capability to microcomputer systems.
Note on Minimal Congruences on Transition Graphs
Authors: B. Reusch
Venue: IEEE Transactions on Computers (1972)

A new proof is given for the following fact: All minimal congruences on a transition graph are of one of four types and can easily be obtained by inspecting the graph.
On the hardness of offline multi-objective optimization
Authors: Olivier Teytaud
Venue: Evolutionary Computation (2007)

It has been empirically established that multiobjective evolutionary algorithms do not scale well with the number of conflicting objectives. This paper shows that the convergence rate of all comparison-based multi-objective algorithms, for the Hausdorff distance, is not much better than the convergence rate of the random search under certain conditions. The number of objectives must be very moderate and the framework should hold the following assumptions: the objectives are conflicting and the computational cost is lower bounded by the number of comparisons is a good model. Our conclusions are: (i) the number of conflicting objectives is relevant (ii) the criteria based on comparisons with random-search for multi-objective optimization is also relevant (iii) having more than 3-objectives optimization is very hard. Furthermore, we provide some insight into cross-over operators.
A Novel Algorithm of Channel Resource Allocation in IEEE 802.11 WLAN
Authors: Liu Yanbing, Zhai Congcong, Sun Shixin
Venue: Proceedings of the 2007 IFIP International Conference on Network and Parallel Computing Workshops (2007)

With the development of bandwidth wireless communications, MAC protocol in IEEE 802.11 can't satisfy user-individual quality of service (QoS) guarantees effectively and can't support high-speed mobility. A novel algorithm for channel allocation in bandwidth WLAN and an improved resource reservation mechanism applied into IEEE 802.11 MAC protocol are proposed in this article. The simulated results indicate that the advanced protocol makes the system throughput improved and delay decrease. Moreover, the improved system shows an excellent performance in the environment with high-speed mobility.
Symbolic Bisimulations for Probabilistic Systems
Authors: Peng Wu, Catuscia Palamidessi, Huimin Lin
Venue: Proceedings of the Fourth International Conference on Quantitative Evaluation of Systems (2007)

The paper introduces symbolic bisimulations for a simple probabilistic \pi-calculus to overcome the infinite branching problem that still exists in checking ground bisimulations between probabilistic systems. Especially the definition of weak (symbolic) bisimulation does not rely on the random capability of adversaries and suggests a solution to the open problem on the axiomatization for weak bisimulation in the case of unguarded recursion. Furthermore, we present an efficient characterization of symbolic bisimulations for the calculus, which allows the "on-the-fly" instantiation of bound names and dynamic construction of equivalence relations for quantitative evaluation. This directly results in a local decision algorithm that can explore just a minimal portion of the state spaces of the probabilistic processes in question.
Ternary Cyclo-Decompositions
Authors: H. Arango, J. Santos, A. Chacur
Venue: IEEE Transactions on Computers (1968)

Abstract This note discusses a particular kind of ternary functional decomposition based on a ternary function ? to be performed on the set of composite functions. Such function is closely related to the cycling concept of Postian algebras. A systematic method is given to determine the set of all decompositions of that kind admitted by the function. Such set is called the cyclo-set and it is proved that it is a filter in the partitions lattice. Since any partition of the lattice can be expressed as an intersection of cardinality-2 partitions, it follows that the method consists merely in finding the infimum of the cardinality-2 partitions belonging to the cyclo-set and then determining the filter having this infimum as vertex. The existence of proper subsets of the cardinality-2 partitions set leading to the determination of the ifiter-vertex is discussed, and results obtained for functions of domain-order up to seven are stated. Finally, the total number of cyclo-decompositions for a given partitional structure is calculated.
New Components for Building Fuzzy Logic Circuits
Authors: Ben Choi, Kunal Tipnis
Venue: Proceedings of the Fourth International Conference on Fuzzy Systems and Knowledge Discovery - Volume 02 (2007)

This paper presents two new designs of fuzzy logic circuit components. Currently due to the lack of fuzzy components, many fuzzy systems cannot be fully implemented in hardware. We propose the designs of a new fuzzy memory cell and a new fuzzy logic gate. Unlike a digital memory cell that can only store either a zero or a one, our fuzzy memory cell can store any value ranging from zero to one. The fuzzy memory cell can also be used as a D-type fuzzy flip-flop, which is the first design of a D-type fuzzy flip-flop. We also designed a new fuzzy NOT gate based only on digital NOT gates that can easily be implemented in CMOS microchips. Our D-type fuzzy flip-flop and fuzzy NOT gate together with fuzzy AND gate and fuzzy OR gate allow us to design and implement fuzzy logic circuits to fully exploit fuzzy paradigms in hardware.
Providing awareness through situated process maps: the hospital care case
Authors: Federico Cabitza, Marcello Sarini, Carla Simone
Venue: Proceedings of the 2007 international ACM conference on Supporting group work (2007)

Clinical Pathways (CPs) are artifacts that clinicians are increasingly introducing in their practices in order to deal with health problems in the most effective, efficient and agreed way. As a result of an observational study at a Neonatology Intensive Care Unit, we found that most CPs are still paper-based. Although perceived useful even on paper, the physicians advocated a system integrating CPs with the clinical record. Based on their requirements, we present a proposal on how to conceive a computational system that can promote awareness in order to achieve better coordination and committed inclusion of pathways in daily clinical practice.
An Introduction to Global Product Line Requirements Engineering
Authors: Andrew J. Kornecki
Venue: Proceedings of the International Conference on Global Software Engineering (2007)

Empirical studies have shown that the use of a product line approach to software development can result in shorter time to market and improved productivity. Outsourcing and distributed development has added a new dimension to product management, exacerbating problems associated with transitioning from marketing studies to product definition to analysis and design. Communication problems can arise when requirements for products are captured on a regional or international basis. This half day tutorial provides an introduction to global product line requirements engineering from the perspective of project and product management. Topics covered include geographically distributed product lines including organizational and technical issues of globalization, distributed requirements elicitation, feature modeling, the role of the product line manager, and the use of meta-models to define global/distributed processes.
On the Conversion of Hensel Codes to Farey Rationals
Authors: E. V. Krishnamurthy
Venue: IEEE Transactions on Computers (1983)

Three different algorithms are described for the conversion of Hensel codes to Farey rationals. The first algorithm is based on the trial and error factorization of the weight of a Hensel code, inversion and range test. The second algorithm is deterministic and uses a pair of different p-adic systems for simultaneous computation; from the resulting weights of the two different Hensel codes of the same rational, two equivalence classes of rationals are generated using the respective primitive roots. The intersection of these two equivalence classes uniquely identifies the rational. Both the above algorithms are exponential (in time and/or space).
Eight key issues for the decision support systems discipline
Authors: David Arnott, Graham Pervan
Venue: Decision Support Systems (2008)

This paper integrates a number of strands of a long-term project that is critically analysing the academic field of decision support systems (DSS). The project is based on the content analysis of 1093 DSS articles published in 14 major journals from 1990 to 2004. An examination of the findings of each part of the project yields eight key issues that the DSS field should address for it to continue to play an important part in information systems scholarship. These eight issues are: the relevance of DSS research, DSS research methods and paradigms, the judgement and decision-making theoretical foundations of DSS research, the role of the IT artifact in DSS research, the funding of DSS research, inertia and conservatism of DSS research agendas, DSS exposure in general ''A'' journals, and discipline coherence. The discussion of each issue is based on the data derived from the article content analysis. A number of suggestions are made for the improvement of DSS research. These relate to case study research, design science, professional relevance, industry funding, theoretical foundations, data warehousing, and business intelligence. The suggestions should help DSS researchers construct high quality research agendas that are relevant and rigorous.
Evaluating tagging behavior in social bookmarking systems: metrics and design heuristics
Authors: Umer Farooq, Thomas G. Kannampallil, Yang Song, Craig H. Ganoe, John M. Carroll, Lee Giles
Venue: Proceedings of the 2007 international ACM conference on Supporting group work (2007)

To improve existing social bookmarking systems and to design new ones, researchers and practitioners need to understand how to evaluate tagging behavior. In this paper, we analyze over two years of data from CiteULike, a social bookmarking system for tagging academic papers. We propose six tag metrics-tag growth, tag reuse, tag non-obviousness, tag discrimination, tag frequency, and tag patterns-to understand the characteristics of a social bookmarking system. Using these metrics, we suggest possible design heuristics to implement a social bookmarking system for CiteSeer, a popular online scholarly digital library for computer science. We believe that these metrics and design heuristics can be applied to social bookmarking systems in other domains.
Configurable Multi-Processor Platforms for Next Generation Embedded Systems
Authors: David Goodwin, Chris Rowen, Grant Martin
Venue: Proceedings of the 2007 Asia and South Pacific Design Automation Conference (2007)

Next-generation embedded systems in application domains such as multimedia, wired and wireless communications, and multipurpose portable devices, are increasingly turning to multiprocessor platforms as a vehicle for their realization. But entirely fixed platforms composed of entirely fixed components lack the flexibility and ability to be optimized to the application to offer the best solution in any of these areas. Configurability at multiple levels offers a much better chance to optimize the resulting multiprocessor platform. Existing and emerging technologies for configurable and extensible processors and the creation of configurable multiprocessor subsystem platforms offer significant capability to design teams to both differentiate and optimize their products.