ppxscal/embedding_network huggingface dataset:
A local semi-supervised Sammon algorithm for textual data visualization
Authors: Manuel Martín-Merino, Ángela Blanco
Venue: Journal of Intelligent Information Systems (2009)

Sammon's mapping is a powerful non-linear technique that allow us to visualize high dimensional object relationships. It has been applied to a broad range of practical problems and particularly to the visualization of the semantic relations among terms in textual databases. The word maps generated by the Sammon mapping suffer from a low discriminant power due to the well known "curse of dimensionality" and to the unsupervised nature of the algorithm. Fortunately the textual databases provide frequently a manually created classification for a subset of documents that may help to overcome this problem. In this paper we first introduce a modification of the Sammon mapping (SSammon) that enhances the local topology reducing the sensibility to the 'curse of dimensionality'. Next a semi-supervised version is proposed that takes advantage of the a priori categorization of a subset of documents to improve the discriminant power of the word maps generated. The new algorithm has been applied to the challenging problem of word map generation. The experimental results suggest that the new model improves significantly well known unsupervised alternatives.
Developing parallel programs: A design-oriented perspective
Authors: Ali Ebnenasir, Rasoul Beik
Venue: Proceedings of the 2009 ICSE Workshop on Multicore Software Engineering (2009)

The behavioral correctness of parallel programs has a pivotal role in computational sciences and engineering applications as researchers draw scientific conclusions from the results generated by parallel applications. Moreover, with the advent of multicore processors, the development of parallel programs should be facilitated for the mainstream developers. While numerous programming models and APIs exist for parallel programming, we pose the view that more emphasis should be placed on designing the synchronization mechanisms of parallel programs independent from the design of their functional behaviors. More importantly, programs behaviors evolve (due to new requirements and change of configuration), thereby creating a need for techniques and tools that enable developers to reason about the behavioral evolution of parallel programs. With such motivations, we introduce a framework for automated design/evolution of the synchronization mechanisms of parallel programs.
Operating Systems: A Spiral Approach, 1 edition
Authors: Ramez Elmasri, A Carrick, David Levine
Venue:  (2009)

Elmasri, Levine, and Carrick's "spiral approach" to teaching operating systems develops student understanding of various OS components early on and helps students approach the more difficult aspects of operating systems with confidence. While operating systems have changed dramatically over the years, most OS books use a linear approach that covers each individual OS component in depth, which is difficult for students to follow and requires instructors to constantly put materials in context. Elmasri, Levine, and Carrick do things differently by following an integrative or "spiral" approach to explaining operating systems. The spiral approach alleviates the need for an instructor to "jump ahead" when explaining processes by helping students "completely" understand a simple, working, functional system as a whole in the very beginning. This is more effective pedagogically, and it inspires students to continue exploring more advanced concepts with confidence. Table of contents PART 1: Operating Systems Overview and Background1 Getting Started 2 Operating System Concepts, Components, and ArchitecturesPART 2: Building Operating Systems Incrementally: A Breadth-Oriented Spiral Approach3 A Simple, Single-Process Operating System 4 A Single-User Multitasking Operating System 5 A Single-User Multitasking/Multithreading Operating System 6 A Multiple-User Operating System7 Parallel and Distributed Computing, Clusters, and Grids PART 3: CPU and Memory Management8 Process Management: Concepts, Threads, and Scheduling 9 More Process Management: Interprocess Communication, Synchronization, and Deadlocks 10 Basic Memory Management 11 Advanced Memory Management PART 4: A Depth-Oriented Presentation of OS Concepts: Files Systems and Input/Output 12 File Systems - Basics 13 File Systems - Examples and More Features 14 Disk Scheduling and Input/Output Management PART 5: Networks, Distributed Systems, and Security15 Introduction to Computer Networks 16 Protection and Security17 Distributed Operating Systems PART 6: Case Studies18 Windows NT™ through Vista™ 19 Linux: A Case Study20 Palm OS: A Class Case Study Appendices Appendix A: Overview of Computer System and Architecture Concepts
Isothermality: making speculative optimizations affordable
Authors: David John Pereira
Venue:  (2008)

Partial Redundancy Elimination (PRE) is a ubiquitous optimization used by compilers to remove repeated computations from programs. Speculative PRE (SPRE), which uses program profiles (statistics obtained from running a program), is more cognizant of trends in run time behaviour and therefore produces better optimized programs. Unfortunately, the optimal version of SPRE is a very expensive algorithm, of high-order polynomial time complexity, and unlike most compiler optimizations, which run effectively in linear time complexity over the size of the program that they are optimizing. This dissertation uses the concept of &ldquo;isothermality&rdquo;&mdash;the division of a program into a hot region and a cold region&mdash;to create the Isothermal SPRE (ISPRE) optimization, an approximation to optimal SPRE. Unlike SPRE, which creates and solves a flow network for each program expression being optimized&mdash;a very expensive operation&mdash;ISPRE uses two simple bit-vector analyses, optimizing all expressions simultaneously. We show, experimentally, that the ISPRE algorithm works, on average, nine times faster than the SPRE algorithm, while producing programs that are optimized competitively. This dissertation also harnesses the power of isothermality to empower another kind of ubiquitous compiler optimization, Partial Dead Code Elimination (PDCE), which removes computations whose values are not used. Isothermal Speculative PDCE (ISPDCE) is a new, simple, and efficient optimization which requires only three bit-vector analyses. We show, experimentally, that ISPDCE produces superior optimization than PDCE, while keeping a competitive running time. On account of their small analysis costs, ISPRE and ISPDCE are especially appropriate for use in Just-In-Time ( JIT) compilers. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Improvements of semi-implicit schemes for hyperbolic balance laws applied on open channel flow equations
Authors: Bojan Crnković, Nelida rnjarić-ic, Lado Kranjčević
Venue: Computers Mathematics with Applications (2009)

In this paper, we consider a well-balanced semi-implicit one parameter family of schemes. The presented schemes are a generalization of the well-balanced upwind explicit finite volume schemes. The schemes are applied to the Saint Venant open channel flow equations. The main feature of the presented schemes is their balancing property, achieved even for the channels with the general cross section geometry. In the paper, we present the scheme algorithm and the proof of the exact conservation property when the proposed schemes are applied to the open channel flow equations. Furthermore, the schemes' accuracy and stability are improved by using a local semi-implicit approach, which takes into account the CFL number locally. In this way, the highly efficient, robust, and unconditionally stable family of balanced numerical schemes is developed. Newly developed schemes are able to give accurate low diffusion results in stationary as well as in non-stationary test cases. Since particular attention is focused on the simulation efficiency on real engineering problems, an algorithm for treatment and precomputation of channel geometry parameters is presented. The algorithm significantly reduces the computational cost of the simulation. Behavior of new schemes is analyzed in several idealized test cases, and on a simulation of a realistic flood wave propagation in the Kupa river involving friction, non-uniform bed slopes and strong channel width variations.
A model-free ensemble method for class prediction with application to biomedical decision making
Authors: Ralph L. Kodell, Bruce A. Pearce, Songjoon Baek, Hojin Moon, Hongshik Ahn, John F. Young, James J. Chen
Venue: Artificial Intelligence in Medicine (2009)

Objective: A classification algorithm that utilizes two-dimensional convex hulls of training-set samples is presented. Methods and material: For each pair of predictor variables, separate convex hulls of positive and negative samples in the training set are formed, and these convex hulls are used to classify test points according to a nearest-neighbor criterion. An ensemble of these two-dimensional convex-hull classifiers is formed by trimming the "mC"2 possible classifiers derived from the m predictors to a set of classifiers comprised of only unique predictor variables. Because only two-dimensional spaces are required to be populated by training-set samples, the ''curse of dimensionality'' is not an issue. At the same time, the power of ensemble voting is exploited by combining the classifications of the unique two-dimensional classifiers to reach a final classification. Results: The algorithm is illustrated by application to three publicly available biomedical data sets with genomic predictors and is shown to have prediction accuracy that is competitive with a number of published classification procedures. Conclusion: Because of its superior performance in terms of sensitivity and negative predictive value compared to its competitors, the convex-hull ensemble classifier demonstrates good potential for medical screening, where often the major emphasis is placed on having reliable negative predictions.
A system level energy model and energy-quality evaluation for integrated transceiver front-ends
Authors: Ye Li, Bertan Bakkaloglu, Chaitali Chakrabarti
Venue: IEEE Transactions on Very Large Scale Integration (VLSI) Systems (2007)

As CMOS technology scales down, digital supply voltage and digital power consumption goes down. However, the supply voltage and power consumption of the RF front-end and analog sections do not scale in a similar fashion. In fact, in many state-of-the-art communication transceivers, RF and analog sections can consume more energy compared to the digital part. In this paper, first, a system level energy model for all the components in the RF and analog front-end is presented. Next, the RF and analog front-end energy consumption and communication quality of three representative systems are analyzed: a single user point-to-point wireless data communication system, a multi-user code division multiple access (CDMA)-based system and a receive-only video distribution system. For the single user system, the effect of occupied signal bandwidth, peak-to-average ratio (PAR), symbol rate, constellation size, and pulse-shaping filter roll-off factor is analyzed; for the CDMA-based multi-user system, the effect of the number of users in the cell and multiple access interference (MAI) along with the PAR and filter roll-off factor is studied; for the receive-only system, the effect of 1/f noise for direct-conversion receiver and the effect of IF frequency for low-IF architecture on the RF front-end power consumption is analyzed. For a given communication quality specification, it is shown that the energy consumption of a wireless communication front-end can be scaled down by adjusting parameters such as the pulse shaping filter roll-off factor, constellation size, symbol rate, number of users in the cell, and signal center frequency.
Structural Differentiation and Ambidexterity: The Mediating Role of Integration Mechanisms
Authors: Justin J. P. Jansen, Michiel P. Tempelaar, Frans A. J. van den Bosch, Henk W. Volberda
Venue: Organization Science (2009)

Prior studies have emphasized that structural attributes are crucial to simultaneously pursuing exploration and exploitation, yet our understanding of antecedents of ambidexterity is still limited. Structural differentiation can help ambidextrous organizations to maintain multiple inconsistent and conflicting demands; however, differentiated exploratory and exploitative activities need to be mobilized, coordinated, integrated, and applied. Based on this idea, we delineate formal and informal senior team integration mechanisms (e.g., contingency rewards and social integration) and formal and informal organizational integration mechanisms (e.g., cross-functional interfaces and connectedness) and examine how they mediate the relationship between structural differentiation and ambidexterity. Overall, our findings suggest that the previously asserted direct effect of structural differentiation on ambidexterity operates through informal senior team (i.e., senior team social integration) and formal organizational (i.e., cross-functional interfaces) integration mechanisms. Through this richer explanation and empirical assessment, we contribute to a greater clarity and better understanding of how organizations may effectively pursue exploration and exploitation simultaneously to achieve ambidexterity.
Cylindrical model of transient heat conduction in automotive fuse using conservative averaging method
Authors: Raimonds Vilums, Hans-Dieter Liess, Andris Buikis, Andis Rudevics
Venue: Proceedings of the 13th WSEAS international conference on Applied mathematics (2008)

Cylindrical mathematical model of automotive fuse is considered in this paper. Initially, partial differential equations of the transient heat conduction are given to describe heat-up process in the fuse. Conservative averaging method is used to obtain analytical approximation of these equations by the system of ordinary differential equations. Numerical solution is compared to finite volume approach. Behavior of existing fuses is studied and conclusions are made for improvement.
Uncertainty sampling and transductive experimental design for active dual supervision
Authors: Vikas Sindhwani, Prem Melville, Richard D. Lawrence
Venue: Proceedings of the 26th Annual International Conference on Machine Learning (2009)

Dual supervision refers to the general setting of learning from both labeled examples as well as labeled features. Labeled features are naturally available in tasks such as text classification where it is frequently possible to provide domain knowledge in the form of words that associate strongly with a class. In this paper, we consider the novel problem of active dual supervision, or, how to optimally query an example and feature labeling oracle to simultaneously collect two different forms of supervision, with the objective of building the best classifier in the most cost effective manner. We apply classical uncertainty and experimental design based active learning schemes to graph/kernel-based dual supervision models. Empirical studies confirm the potential of these schemes to significantly reduce the cost of acquiring labeled data for training high-quality models.
An experimental investigation of set intersection algorithms for text searching
Authors: Jérémy Barbay, Alejandro López-Ortiz, Tyler Lu, Alejandro Salinger
Venue: Journal of Experimental Algorithmics (JEA) (2009)

The intersection of large ordered sets is a common problem in the context of the evaluation of boolean queries to a search engine. In this article, we propose several improved algorithms for computing the intersection of sorted arrays, and in particular for searching sorted arrays in the intersection context. We perform an experimental comparison with the algorithms from the previous studies from Demaine, L&oacute;pez-Ortiz, and Munro [ALENEX 2001] and from Baeza-Yates and Salinger [SPIRE 2005]; in addition, we implement and test the intersection algorithm from Barbay and Kenyon [SODA 2002] and its randomized variant [SAGA 2003]. We consider both the random data set from Baeza-Yates and Salinger, the Google queries used by Demaine et al., a corpus provided by Google, and a larger corpus from the TREC Terabyte 2006 efficiency query stream, along with its own query log. We measure the performance both in terms of the number of comparisons and searches performed, and in terms of the CPU time on two different architectures. Our results confirm or improve the results from both previous studies in their respective context (comparison model on real data, and CPU measures on random data) and extend them to new contexts. In particular, we show that value-based search algorithms perform well in posting lists in terms of the number of comparisons performed.
A new dual wing harmonium model for document retrieval
Authors: Haijun Zhang, Tommy W. S. Chow, M. K. M. Rahman
Venue: Pattern Recognition (2009)

A new dual wing harmonium model that integrates term frequency features and term connection features into a low dimensional semantic space without increase of computation load is proposed for the application of document retrieval. Terms and vectorized graph connectionists are extracted from the graph representation of document by employing weighted feature extraction method. We then develop a new dual wing harmonium model projecting these multiple features into low dimensional latent topics with different probability distributions assumption. Contrastive divergence algorithm is used for efficient learning and inference. We perform extensive experimental verification, and the comparative results suggest that the proposed method is accurate and computationally efficient for document retrieval.
Antfarm: efficient content distribution with managed swarms
Authors: Ryan S. Peterson, Emin Gün Sirer
Venue: Proceedings of the 6th USENIX symposium on Networked systems design and implementation (2009)

This paper describes Antfarm, a content distribution system based on managed swarms. A managed swarm couples peer-to-peer data exchange with a coordinator that directs bandwidth allocation at each peer. Antfarm achieves high throughput by viewing content distribution as a global optimization problem, where the goal is to minimize download latencies for participants subject to bandwidth constraints and swarm dynamics. The system is based on a wire protocol that enables the Antfarm coordinator to gather information on swarm dynamics, detect misbehaving hosts, and direct the peers' allotment of upload bandwidth among multiple swarms. Antfarm's coordinator grants autonomy and local optimization opportunities to participating nodes while guiding the swarms toward an efficient allocation of resources. Extensive simulations and a PlanetLab deployment show that the system can significantly outperform centralized distribution services as well as swarming systems such as BitTorrent.
Ontology learning from domain specific web documents
Authors: Maryam Hazman, Samhaa R. El-Beltagy, Ahmed Rafea
Venue: International Journal of Metadata, Semantics and Ontologies (2009)

Ontologies play a vital role in many web- and internet-related applications. This work presents a system for accelerating the ontology building process via semi-automatically learning a hierarchal ontology given a set of domain-specific web documents and a set of seed concepts. The methods are tested with web documents in the domain of agriculture. The ontology is constructed through the use of two complementary approaches. The presented system has been used to build an ontology in the agricultural domain using a set of Arabic extension documents and evaluated against a modified version of the AGROVOC ontology.
A proposal for error handling in OpenMP
Authors: Alejandro Duran, Roger Ferrer, Juan José Costa, Marc Gonzàz, Xavier Martorell, Eduard Ayguadé, Jesú Labarta
Venue: International Journal of Parallel Programming (2007)

OpenMP has been focused in performance applied to numerical applications, but when we try to move this focus to other kind of applications, like Web servers, we detect one important lack. In these applications, performance is important, but reliability is even more important, and OpenMP does not have any recovery mechanism. In this paper we present a novel proposal to address this lack. In order to add error handling to OpenMP we propose some extensions to the current OpenMP specification. A directive and a clause are proposed, defining a scope for the error handling (where the error can occur) and specifying a behaviour for handling the specific errors. Some examples of use are presented, and we present also an evaluation showing the impact of this proposal in OpenMP applications. We show that this impact is low enough to consider the proposal worthwhile for OpenMP.
Nonlinear growth models based on the live eye lens weight and age measurements of the European rabbits in Australia and alternative models in multivariate statistics
Authors: Adnan Mazmanoglu, Ali Reha Unlu
Venue: Proceedings of the 2nd WSEAS international conference on Multivariate analysis and its application in science and engineering (2009)

Examining the special model Lens = α exp{-β / (Age + γ)} which belongs to Dudzinski and Mykytowycz (1961), and was used in a study made by them to find the age of Oryctolagus Caniculus, which lives in Europe and is known as the European rabbit, with live eye lens weight, we showed that similar results can be obtained with the Gompertz and Logistic nonlinear regression models. We determined that the results given by the models are showing the goodness of fit, as a result of a statistical analysis. Furthermore we showed that adding various parameters to Dudzinski and Mykytowycz model will not change the results.
A Methodology for Deriving the Architectural Implications of Different Degrees of Mobility in Information Systems
Authors: Matthias Book, Volker Gruhn, Malte Hülder, Clemens Schäfer
Venue: Proceeding of the 2005 conference on New Trends in Software Methodologies, Tools and Techniques: Proceedings of the fourth SoMeT_W05 (2005)

When building information systems that can be accessed through desktop and mobile devices, developers often face the same basic design decisions that depend on a number of still unstructured criteria. Going through the whole decision-making process for every project is inefficient and error-prone, however, a comprehensive set of best practices has not yet been established. We therefore present the foundations of a classification scheme for mobile commerce systems that helps developers to categorize applications according to high-level requirements. After a discussion of the criteria, we suggest implications that can be drawn from it and present examples for their application.
Modelling Learning in an Educational Game
Authors: Micheline Manske, Cristina Conati
Venue: Proceeding of the 2005 conference on Artificial Intelligence in Education: Supporting Learning through Intelligent and Socially Informed Technology (2005)

We describe research on data-drive refinement and evaluation of a probabilistic model of student learning for an educational game on number factorization. The model is to be used by an intelligent pedagogical agent to improve student learning during game play. An initial version of the model was designed based on teachers' advice and subjective parameter settings. Here we illustrate data-driven improvements to the model, and we report results on its accuracy.