ppxscal/embedding_network huggingface dataset:
An experimental study of algorithms for fully dynamic transitive closure
Authors: Ioannis Krommidas, Christos Zaroliagis
Venue: Journal of Experimental Algorithmics (JEA) (2008)

We have conducted an extensive experimental study on algorithms for fully dynamic transitive closure. We have implemented the recent fully dynamic algorithms by King &lsqb;1999&rsqb;, Roditty &lsqb;2003&rsqb;, Roditty and Zwick &lsqb;2002, 2004&rsqb;, and Demetrescu and Italiano &lsqb;2000, 2005&rsqb; along with several variants and compared them to pseudo fully dynamic and simple-minded algorithms developed in a previous study &lsqb;Frigioni et al. 2001&rsqb;. We tested and compared these implementations on random inputs, synthetic (worst-case) inputs, and on inputs motivated by real-world graphs. Our experiments reveal that some of the dynamic algorithms can really be of practical value in many situations.
Locality of Corner Transformation for Multidimensional Spatial Access Methods
Authors: H. K. Dai, K. -Y. Whang, H. C. Su
Venue: Electronic Notes in Theoretical Computer Science (ENTCS) (2008)

The geometric structural complexity of spatial objects does not render an intuitive distance metric on the data space that measures spatial proximity. However, such a metric provides a formal basis for analytical work in transformation-based multidimensional spatial access methods, including locality preservation of the underlying transformation and distance-based spatial queries. We study the Hausdorff distance metric on the space of multidimensional polytopes, and prove a tight relationship between the metric on the original space of k-dimensional hyperrectangles and the standard p-normed metric on the transform space of 2k-dimensional points under the corner transformation, which justifies the effectiveness of the transformation-based technique in preserving spatial locality.
Lightweight task/application performance using single versus multiple monitors: a comparative study
Authors: Youn-ah Kang, John Stasko
Venue: Proceedings of graphics interface 2008 (2008)

It is becoming increasingly common to see computers with two or even three monitors being used today. People seem to like having more display space available, and intuition tells us that the added space should be beneficial to work. Little research has been done to examine the effects and potential utility of multiple monitors for work on everyday tasks with common applications, however. We compared how people completed a trip planning task that involved different applications and included interjected interruptions when they worked on a computer with one monitor as compared to a computer with two monitors. Results showed that participants who used the computer with two monitors performed the task set faster and with less workload, and they also expressed a subjective preference for the multiple monitor computer.
Learning object oriented programming: unique visualizations of individuals learning styles, activities and the programs produced
Authors: Christopher J. Burrell
Venue: Proceedings of the 13th annual conference on Innovation and technology in computer science education (2008)

Constructing new knowledge when learning to program is acknowledged as a difficult process. This poster displays visual models constructed from pre-course questionnaires and the activities and programs produced by novices when taking the first steps in programming. Case study and experimental methods were used to develop these individualized, "student learning models" in an attempt to identify and understand individual differences. A micro-world environment was developed to capture data associated with writing and running programs. Visualizations derived display the resulting learner models which can assist in understanding the developing knowledge state of individuals with the potential of providing a contribution to tutorial support.
A theory of wormhole routing in parallel computers
Authors: S. Felperin
Venue: Proceedings of the 33rd Annual Symposium on Foundations of Computer Science (1992)

Virtually all theoretical work on message routing in parallel computers has dwelt on packet routing: messages are conveyed as packets, an entire packet can reside at a node of the network, and a packet is sent from the queue of one node to the queue of another node until its reaches its destination. The current trend in multicomputer architecture, however, is to use wormhole routing. In wormhole routing a message is transmitted as a contiguous stream of bits, physically occupying a sequence of nodes/edges in the network. Thus, a message resembles a worm burrowing through the network. The authors give theoretical analyses of simple wormhole routing algorithms, showing them to be nearly optimal for butterfly and mesh connected networks. The analysis requires initial random delays in injecting messages to the network. They report simulation results suggesting that the idea of random initial delays is not only useful for theoretical analysis but may actually improve the performance of wormhole routing algorithms.
Persistent clustered main memory index for accelerating k-NN queries on high dimensional datasets
Authors: Alexander Thomasian, Lijuan Zhang
Venue: Multimedia Tools and Applications (2008)

Similarity search implemented via k-nearest neighbor-- k-NN queries on multidimensional indices is an extremely useful paradigm for content-based image retrieval. As the dimensionality of feature vectors increases the curse of dimensionality sets in, i.e., the performance of k-NN search of disk-resident indices in the R-tree family degrades rapidly due to the overlap in index pages in high dimensions. This problem is dealt with in this study by utilizing the double filtering effect of clustering and indexing. The clustering algorithm ensures that the largest cluster fits into main memory and that only clusters closest to a query point need to be searched and hence loaded into main memory. We organize the data in each cluster according to the ordered-partition--OP-tree main memory resident index, which is not prone to the curse of dimensionality and highly efficient for processing k-NN queries. We serialize an OP-tree by writing its dynamically allocated nodes into contiguous memory locations, optimize its parameters, and make it persistent by writing it to disk. The time to read and write clusters constituting an OP-tree with a single sequential access to disk benefits from higher data transfer rates of modern disk drives. The performance of the index is further improved by applying the Karhunen---Loève transformation--KLT to the dataset, since this results in a more efficient computation of distances for k-NN queries. We compare OP-trees and sequential scans with and without a KL-transformation and with and without using a shortcut method in calculating Euclidean distances. A comparison against the OMNI-sequential scan is also reported. We finally compare a clustered and persistent version of the OP-tree against a clustered version of the SR-tree and the VA-file method. CPU time is measured and elapsed time is estimated in this study. It is observed that the OP-tree index outperforms the other two methods and that the improvement increases with the number of dimensions.
Ensemble Model of Intelligent Paradigms for Stock Market Forecasting
Authors: Qiang Wu, Yuehui Chen, Zhen Liu
Venue: Proceedings of the First International Workshop on Knowledge Discovery and Data Mining (2008)

The use of intelligent systems for stock market predictions has been widely established. This paper introduces a ensemble model of SVM and ANNs for the prediction of three stock indices. The performance of this model is then compared with support vector machine model and an artificial neural network respectively. Empirical results reveal that the ensemble result obtain the best results.
Use of PM Bearings in Permanent Maglev Centrifugal Pumps for Stability Investigation
Authors: Kun-xi Qian, Teng Jing
Venue: Proceedings of the 2008 International Conference on BioMedical Engineering and Informatics - Volume 02 (2008)

It has been widely acknowledged that permanent maglev is unstable according to Earnshaw’s theory (1839). The author has found, however, that this theorem is applicable only to a levitator in static state. For dynamic equilibrium, such as by a levitator in rotary pump, there has been no answer until now to the question whether permanent maglev can be stable. To investigate the feasibility of permanent maglev pumps, a passive magnetic(PM) bearing in common use (Bearing A) and a novel PM bearing developed by the author(Bearing B) were used separately in 3 prototypes of centrifugal pumps: axially driven centrifugal pump, radially driven biventricular assist pump and radially driven centrifugal pump. It exhibited that the PM bearings could achieve stable maglev in all centrifugal pumps, if the rotor had high enough speed and thus obtained a so-called gyro-effect, namely, a rotating body with high enough speed could maintain its rotation stably.
NEFRL: A New Neuro-Fuzzy System for Episodic Reinforcement Learning Tasks
Authors: Babak Behsaz, Reza Safabakhsh
Venue: Proceedings of the 2007 Frontiers in the Convergence of Bioscience and Information Technologies (2007)

In this paper, we propose a new neuro-fuzzy system for episodic reinforcement learning tasks, NEFRL. While NEFRL has all benefits of a neuro-fuzzy architecture, it has the additional advantage that it can learn with a numerical evaluation of performance and there is no need for training input-output pairs. Also, we show that the learning algorithm of this system converges with probability one to a local maximum of the average numerical performance signal. Our experimental results for the Pole-Balancing Task show the power of this system even without any prior domain knowledge.
Middleware abstractions for cross-layer controlled media streaming
Authors: Alexander Eichhorn
Venue: Proceedings of the 2nd workshop on Middleware-application interaction: affiliated with the DisCoTec federated conferences 2008 (2008)

Efficiency, quality, and robustness of multimedia delivery over best-effort packet networks can be improved by advanced streaming protocols. This comes, however, at the cost of increased application complexity because existing solutions require close cooperation between transport layers and applications to perform effective adaptations. Media encoders have to become network-aware while transport layers need to consider certain properties of the data they deliver, such as the unequal importance of data units and their timing constraints. Today's adaptive streaming systems are developed jointly, customising encoders, protocols and surrounding code for a specific application. This heavily restricts the reuse of protocol implementations for other encoding formats, different application requirements and network environments. In order to enable reuse and simplify the integration of advanced streaming protocols into applications, we propose the Noja programming model for multimedia middleware layers. Noja's abstractions leverage protocol coordination and provide selective transparency features to effectively hide complexity, but expose necessary control options to application developers. Based on examples we show that Noja is applicable to a broad range of multimedia streaming applications and beyond that to data streaming applications in general.
On the use of fuzzy inference techniques in assessment models: part I--theoretical properties
Authors: Kai Meng Tay, Chee Peng Lim
Venue: Fuzzy Optimization and Decision Making (2008)

An assessment model is a mathematical model that produces a measuring index, either in the form of a numerical score or a category to a situation/object, with respect to the subject of measure. From the numerical score, decision can be made and action can be taken. To allow valid and useful comparisons among various situations/objects according to their associated numerical scores to be made, the monotone output property and the output resolution property are essential in fuzzy inference-based assessment problems. We investigate the conditions for a fuzzy assessment model to fulfill the monotone output property using a derivative approach. A guideline on how the input membership functions should be tuned is also provided. Besides, the output resolution property is defined as the derivative of the output of the assessment model with respect to its input. This derivative should be greater than the minimum resolution required. From the derivative, we suggest improvements to the output resolution property by refining the fuzzy production rules.
Damia: data mashups for intranet applications
Authors: David E. Simmen, Mehmet Altinel, Volker Markl, Sriram Padmanabhan, Ashutosh Singh
Venue: Proceedings of the 2008 ACM SIGMOD international conference on Management of data (2008)

Increasingly large numbers of situational applications are being created by enterprise business users as a by-product of solving day-to-day problems. In efforts to address the demand for such applications, corporate IT is moving toward Web 2.0 architectures. In particular, the corporate intranet is evolving into a platform of readily accessible data and services where communities of business users can assemble and deploy situational applications. Damia is a web style data integration platform being developed to address the data problem presented by such applications, which often access and combine data from a variety of sources. Damia allows business users to quickly and easily create data mashups that combine data from desktop, web, and traditional IT sources into feeds that can be consumed by AJAX, and other types of web applications. This paper describes the key features and design of Damia's data integration engine, which has been packaged with Mashup Hub, an enterprise feed server currently available for download on IBM alphaWorks. Mashup Hub exposes Damia's data integration capabilities in the form of a service that allows users to create hosted data mashups.
Towards goal-oriented development of self-adaptive systems
Authors: Mirko Morandini, Loris Penserini, Anna Perini
Venue: Proceedings of the 2008 international workshop on Software engineering for adaptive and self-managing systems (2008)

Self-adaptive software aims at anticipating changes which occur in a complex environment and to automatically deal with them at run-time. The increasing demand for complex networked software, which makes computing resources available to anyone, anywhere and at any time, is drawing attention to the engineering of self-adaptive software. The objective of our work is to define a process and a tool-supported design framework to develop self-adaptive systems, which consider Belief-Desire-Intention agent models as reference architectures. We adopt an agent-oriented approach, which allows to explicitly model system goals in requirements specification and in the system architecture design. Moreover, goal achievement conditions are specified along with their relationships with the environment and with possible failures, and corresponding recovery actions. This paper aims at motivating and giving an overview of our approach with the help of an example.
Query Processing and Optimization Techniques over Streamed Fragmented XML
Authors: Guoren Wang, Huan Huo, Donghong Han, Xiaoyun Hui
Venue: World Wide Web (2008)

With the extensive use of XML in applications over the Web, efficient query processing over streaming XML has become a core challenge due to one-pass processing and limited resources. Taking advantage of Hole-Filler model for XML fragments, this paper proposes a hybrid structure (FQ-Index) for both the queries and fragments, and proposes an XML fragment processing algorithm to evaluate forward XPath queries over streamed XML fragments. Two optimization rules, dependence pruning and prefix pruning are also developed. Dependence pruning scheme prunes off the dependent operations caused by fragmentation and transforms the queries for XML tag into queries for XML fragments, while prefix pruning scheme prunes off the "redundant" prefix along the path according to the tag structure. The effectiveness of the techniques developed is illustrated with a detailed set of experiments.
Numerical integration schemes for Petrov--Galerkin infinite BEM
Authors: A. Aimi, M. Diligenti
Venue: Applied Numerical Mathematics (2008)

The present article discusses the numerical approximation of hypersingular integral equations arising from Neumann two-dimensional elliptic problems defined over unbounded domains with unbounded boundaries by using a Petrov-Galerkin infinite boundary element method as discretization technique. An analysis of the singularities, arising during the double integration process needed for the generation of the stiffness matrix elements related to the infinite mesh elements, is carried out and efficient quadrature schemes are proposed. Several numerical results, involving linear elasticity and potential problems defined over various unbounded domains are presented.
Application-Level Fault-Tolerance Solutions for Grid Computing
Authors: Daniel Díaz, Xoán C. Pardo, María J. Martín, Patricia González
Venue: Proceedings of the 2008 Eighth IEEE International Symposium on Cluster Computing and the Grid (2008)

One of the key functionalities provided by Grid systems is the remote execution of applications. This paper introduces a research proposal on fault-tolerance mechanisms for the execution of sequential and message-passing parallel applications on the Grid. A service-based architecture called CPPC-G is proposed. The CPPC (Controller/Precompiler for Portable Checkpointing) framework is used to insert checkpointing instrumentation into the application code. CPPC-G services will be in charge of the submission and monitoring of the application execution, management of checkpoint files generated by CPPC-enabled applications, and detection and automatic restart of failed executions. The development of the CPPC-G architecture will involve research in different areas such as storage and management of data files (checkpoint files); automatic selection of suitable computing resources; reliable detection of execution failures and robustness issues to make the architecture fault-tolerant itself.
Development of a nanostructural microwave probe based on GaAs
Authors: Y. Ju, T. Kobayashi, H. Soyama
Venue: Microsystem Technologies (2008)

In order to develop a new structural microwave probe, we studied the fabrication of an AFM probe on a GaAs wafer. A waveguide was introduced by evaporating Au film on the top and bottom surfaces of the GaAs AFM probe where a tip 7&#x00a0;&#x03bc;m high with a 2.0 aspect ratio was formed and the dimensions of the cantilever were 250&#x00a0;&#x00d7;&#x00a0;30&#x00a0;&#x00d7;&#x00a0;15&#x00a0;&#x03bc;m. The open structure of the waveguide at the tip of the probe was obtained by FIB fabrication. An AFM image and profile analysis for a standard sample, obtained by the fabricated GaAs microwave probe and a commercial Si AFM probe, indicate that the fabricated probe has a similar capability for measurement of material topography as compared to the commercial probe.
Warm-up periods in simulation can be detrimental
Authors: Winfried k. Grassmann
Venue: Probability in the Engineering and Informational Sciences (2008)

The question of how long to run a discrete event simulation before data collection starts is an important issue when estimating steady-state performance measures such as average queue lengths. By using experiments based on numerical (nonsimulation) methods published elsewhere, we shed light on this question. Our experiments indicate that no initialization phase should be used when starting in state with a reasonable high equilibrium probability. Delaying data collection is only justified if the starting state is highly unlikely, and data collection should start as soon as a system enters a state with reasonably high probability.
A self-tunning method of fuzzy inference rules using counter propagation networks
Authors: Hiromi Miyajima, Shinya Fukumoto, Noritaka Shigei, Kazuya Kishida
Venue: Proceedings of the 2nd WSEAS International Conference on Electronics, Control and Signal Processing (2003)

This paper describes a learning method of fuzzy rules using counter propagation networks (CPNs). First, the initial assignment of fuzzy rules by use of CPNs is determined. Further the number of fuzzy rules to an objective value, inference error, is determined by a constructive method. In order to demonstrate the validity of the proposed method, some numerical simulations are performed.
Towards the construction of a language for describing the learning potential of computing activities
Authors: Gary S. Stager
Venue: Informatics in education (2007)

This paper represents a first attempt at constructing a language for describing the potential learning value of computers as a learning material. A lack of precision in describing the value computers add to the learning process has paradoxically made it easy for people to elevate the significance of using computers in pedestrian ways while simultaneously marginalizing higher-order uses such as Logo programming. Colleagues are invited to extend or challenge this paper's hypotheses. In the early 1980s Seymour Papert was dissatisfied with Robert Taylor's metaphors for the use of the computer in education. Taylor wrote about the computer as a tool, tutor or tutee (Taylor, 1980) while Papert described the computer as "mudpie" (Papert, 1980a; Papert, 1984) and then later more generally as material (Papert and Franz, 1987). The tool metaphor dominates most discourse regarding the use of computers in education. Educators and policy-makers alike use it to describe nearly every application of "technology". It would be impossible to list all of the examples of "computer as tool" in common usage or even scholarship. This work attempts to define the continuum that lies between the use of computers to reinforce traditional practice and the powerful ideas Papert writes of in Mindstorms (Papert, 1980b). While Papert's subsequent work provides examples of the construction of powerful ideas he fails to identify less powerful uses of computers. This may be the result of simple omission or a desire to appear polite. In either case all manner of computer-based activities have been granted equivalence by an education community lacking a precise metric for assessing value. When combined with the liberal and often inaccurate use of terms like constructivist we are left with a culture of intellectual relativism in which the loudest voice sets the standard. Dichotomies like conservative/liberal, traditional/progressive, Democratic/Republican are inadequate for describing educational philosophy and its resulting translation into practice. Papert's instructionism vs. constructionism seems a more precise way of describing one's learning theory and the practice that follows. It seems impossible to invent an empirical metric for measuring the efficacy of computer use in the context of education. There are simply too many variables involved in a complex system such as education. The nature of learning is even more difficult to quantify in anything but a reductionist fashion. Therefore, I propose the creation of a continuum that spans the gulf between traditional education routines possibly enhanced by the use of a computer and the sort of powerful idea construction only possible with the purposeful use of the computer. The subjectivity of the examples are acknowledge, but are intended to generate discussion. Compelling examples of children, computers and powerful ideas will be presented at Eurologo.