ppxscal/embedding_network huggingface dataset:
Complete optimal deployment patterns for full-coverage and k-connectivity (k≤6) wireless sensor networks
Authors: Xiaole Bai, Dong Xuan, Ziqiu Yun, Ten H. Lai, Weijia Jia
Venue: Proceedings of the 9th ACM international symposium on Mobile ad hoc networking and computing (2008)

In this paper, we propose deployment patterns to achieve full coverage and three-connectivity, and full coverage and five-connectivity under different ratios of sensor communication range (denoted by Rc) over sensing range (denoted by Rs) for wireless sensor networks (WSNs). We also discover that there exists a hexagon-based universally elemental pattern which can generate all known optimal patterns. The previously proposed Voronoi-based approach can not be applied to prove the optimality of the new patterns due to their special features. We propose a new deployment-polygon based methodology, and prove their optimality among regular patterns when Rc/Rs ≥ 1. We conjecture that our patterns are globally optimal to achieve full coverage and three-connectivity, and full coverage and five-connectivity, under all ranges of Rc/Rs. With these new results, the set of optimal patterns to achieve full coverage and k-connectivity (k≤6) is complete, for the first time.
Visual Motor Control of a 7 DOF Robot Manipulator Using Function Decomposition and Sub-Clustering in Configuration Space
Authors: Swagat Kumar, Naman Patel, Laxmidhar Behera
Venue: Neural Processing Letters (2008)

This paper deals with real-time implementation of visual-motor control of a 7 degree of freedom (DOF) robot manipulator using self-organized map (SOM) based learning approach. The robot manipulator considered here is a 7 DOF PowerCube manipulator from Amtec Robotics. The primary objective is to reach a target point in the task space using only a single step movement from any arbitrary initial configuration of the robot manipulator. A new clustering algorithm using Kohonen SOM lattice has been proposed that maintains the fidelity of training data. Two different approaches have been proposed to find an inverse kinematic solution without using any orientation feedback. In the first approach, the inverse Jacobian matrices are learnt from the training data using function decomposition. It is shown that function decomposition leads to significant improvement in accuracy of inverse kinematic solution. In the second approach, a concept called sub-clustering in configuration space is suggested to provide multiple solutions for the inverse kinematic problem. Redundancy is resolved at position level using several criteria. A redundant manipulator is dexterous owing to the availability of multiple configurations for a given end-effector position. However, existing visual motor coordination schemes provide only one inverse kinematic solution for every target position even when the manipulator is kinematically redundant. Thus, the second approach provides a learning architecture that can capture redundancy from the training data. The training data are generated using explicit kinematic model of the combined robot manipulator and camera configuration. The training is carried out off-line and the trained network is used on-line to compute the joint angle vector to reach a target position in a single step only. The accuracy attained is better than the current state of art.
Variational convergence of bivariate functions: lopsided convergence
Authors: Alejandro Jofr&#x00e9;, Roger J.-B. Wets
Venue: Mathematical Programming: Series A and B (2008)

We explore convergence notions for bivariate functions that yield convergence and stability results for their maxinf (or minsup) points. This lays the foundations for the study of the stability of solutions to variational inequalities, the solutions of inclusions, of Nash equilibrium points of non-cooperative games and Walras economic equilibrium points, of fixed points, of solutions to inclusions, the primal and dual solutions of convex optimization problems and of zero-sum games. These applications will be dealt with in a couple of accompanying papers.
The 26 December 2004 tsunami measured by satellite altimetry
Authors: J. Gower
Venue: International Journal of Remote Sensing (2007)

The 26 December 2004 magnitude 9 earthquake off Sumatra provided the first examples of travelling tsunami waves in mid-ocean clearly detected by satellite altimetry. The earthquake was the largest since satellite altimetry started in the 1970s and gave peak-to-trough wave heights in mid-ocean of over a metre. The tsunami was detected by three of the four altimeters presently giving sea surface height information. Each detected the spreading front twice, as it moved south-westwards into the Indian Ocean and as it moved northwards into the Bay of Bengal. They also detected the disturbed region closer to the epicentre that expands with the slower velocities of higher-frequency waves. Although the plate rupture is estimated to extend over about 1300 km in a north/south direction, the satellite observations appear consistent with a smaller generation area towards the south of this rupture zone. Fronts observed in the Indian Ocean show a positive first crest. Those observed in the Bay of Bengal are of smaller amplitude and appear to show a first negative first crest (trough). The structure in the Indian Ocean front observed by Jason-1 suggests the possible presence of a shorter-wavelength negative component superimposed on the positive crest.
A comparative study of local thresholding methods for document image binarization
Authors: Francisco Jiménez-López, David Cuesta-Frau, Jordi Linares-Pellicer, Pau Micó-Tormos
Venue: Machine Graphics Vision International Journal (2006)

This paper provides a comparative study of several local thresholding techniques applied in the binarization of document images with text and graphs. First, the methods are described, and then a quantitative comparative analysis is carried out. Ground truth images are used in the experiments to provide an objective measure, and computational costs are also compared.
In requirements engineering, everything is an aspect
Authors: Daniel M. Berry
Venue: Proceedings of the 13th international workshop on Early Aspects (2008)

This keynote is intended to provoke a discussion on crosscutting in early stages of software development. Both proponents and opponents of Early Aspects are invited to attend. The speaker works in requirements engineering (RE) and is not directly involved with work on Early Aspects. Nevertheless, RE is certainly early. The speaker believes that in RE, one never sees any cross-cutting concerns, but there are plenty of concerns there and these are all requirements. The speaker is of the view that, in the early stages, requirements are not well enough structured, and that, any concern can be identified as crosscutting as opposed to not crosscutting. Consequently, it is hard to define which concerns are crosscutting and which are not. Everything is just a concern. Nevertheless, there will certainly be crosscutting concerns later when the required system is built.
Hardness amplification proofs require majority
Authors: Ronen Shaltiel, Emanuele Viola
Venue: Proceedings of the 40th annual ACM symposium on Theory of computing (2008)

Hardness amplification is the fundamental task of converting a δ-hard function f : (0, 1)n -> (0, 1) into a (1/2-ε)-hard function Amp(f), where f is γ-hard if small circuits fail to compute f on at least a γ fraction of the inputs. Typically, ε,δ are small (and δ=2-k captures the case where f is worst-case hard). Achieving ε = 1/nΩ(1) is a prerequisite for cryptography and most pseudorandom-generator constructions. In this paper we study the complexity of black-box proofs of hardness amplification. A class of circuits cal D proves a hardness amplification result if for any function h that agrees with Amp(f) on a 1/2+e fraction of the inputs there exists an oracle circuit D ∈ D such that Dh agrees with f on a 1-δ fraction of the inputs. We focus on the case where every D ∈ D makes non-adaptive queries to h. This setting captures most hardness amplification techniques. We prove two main results: The circuits in D "can be used" to compute the majority function on 1e bits. In particular, these circuits have large depth when ε ≤ 1/ poly log n. The circuits in D must make Ω log(1/δ)/e2 oracle queries. Both our bounds on the depth and on the number of queries are tight up to constant factors. Our results explain why hardness amplification techniques have failed to transform known lower bounds against constant-depth circuit classes into strong average-case lower bounds. When coupled with the celebrated "Natural Proofs" result by Razborov and Rudich (J. CSS '97) and the pseudorandom functions by Naor and Reingold (J. ACM '04), our results show that standard techniques for hardness amplification can only be applied to those circuit classes for which standard techniques cannot prove circuit lower bounds. Our results reveal a contrast between Yao's XOR Lemma (Amp(f) := f(x1) ⊕ ... ⊕ f(xt) ∈ zo) and the Direct-Product Lemma (Amp(f) := f(x1) O ... O f(xt) ∈ zot; here Amp(f) is non-Boolean). Our results (1) and (2) apply to Yao's XOR lemma, whereas known proofs of the direct-product lemma violate both (1) and (2). One of our contributions is a new technique to handle "non-uniform" reductions, i.e. the case when D contains many circuits.
Approximate optimization methods of control of a flying vehicle
Authors: V. I. Gurman, V. N. Kvokov, M. Yu. Ukhin
Venue: Automation and Remote Control (2008)

An approximate approach is suggested to the investigation of optimal control of flying vehicles as complex objects, which do not generally have the complete analytical description, with the aim of extending the possibilities of the qualitative analysis with the use of effective special methods and procedures that account for specific features of applied problems, such as the degeneracy and the main nature of their solutions. Provision is made for the approximation of multidimensional numerical arrays generated on practical simulation models of controllable objects by analytical structures of the various complexity and accuracy and the search on their basis for a roughly approximate global solution with the subsequent iterative refinement. As a meaningful example, the investigation is considered of maneuvers of the safe nonregular landing of a helicopter with the definition of the boundary of a safe zone.
A method using time series analysis for IEEE 802.11 WLANs channel forecasting
Authors: Jeandro Bezerra, Rudy Braquehais, Filipe Roberto, Jorge Silva, Marcial Fernandez, Thelmo de Araújo, Celestino Junior
Venue: Proceedings of the 2007 Euro American conference on Telematics and information systems (2007)

The growth of wireless network use has greatly increased research demand. Some applications, which are context-aware, must adapt to the environment. So, information on both environment characteristics and the device's hardware are crucial. In this work, a new method called Natural Adaptive Exponential Smoothing (NAES) is proposed. It describes and forecasts, in real time, IEEE 802.11 WLAN networks channel behavior. The NAES method is a variation of the exponential smoothing technique to compute the channel quality indicators, namely the Received Signal Strength (RSS) and the link quality. A comparison with the results obtained by the Trigg and Leach (TL) method shows that NAES outperforms TL method.
Improving text classification accuracy using topic modeling over an additional corpus
Authors: Somnath Banerjee
Venue: Proceedings of the 31st annual international ACM SIGIR conference on Research and development in information retrieval (2008)

The World Wide Web has many document repositories that can act as valuable sources of additional data for various machine learning tasks. In this paper, we propose a method of improving text classification accuracy by using such an additional corpus that can easily be obtained from the web. This additional corpus can be unlabeled and independent of the given classification task. The method proposed here uses topic modeling to extract a set of topics from the additional corpus. Those extracted topics then act as additional features of the data of the given classification task. An evaluation on the RCV1 dataset shows significant improvement over a baseline method.
Asymptotic relations between the Hahn-type polynomials and Meixner-Pollaczek, Jacobi, Meixner and Krawtchouk polynomials
Authors: Chelo Ferreira, José L. López, Ester Pérez Sinusía
Venue: Journal of Computational and Applied Mathematics (2008)

It has been shown in Ferreira et al. [Asymptotic relations in the Askey scheme for hypergeometric orthogonal polynomials, Adv. in Appl. Math. 31(1) (2003) 61-85], Lopez and Temme [Approximations of orthogonal polynomials in terms of Hermite polynomials, Methods Appl. Anal. 6 (1999) 131-146; The Askey scheme for hypergeometric orthogonal polynomials viewed from asymptotic analysis, J. Comput. Appl. Math. 133 (2001) 623-633] that the three lower levels of the Askey table of hypergeometric orthogonal polynomials are connected by means of asymptotic relations. In Ferreira et al. [Limit relations between the Hahn polynomials and the Hermite, Laguerre and Charlier polynomials, submitted for publication] we have established new asymptotic connections between the fourth level and the two lower levels. In this paper, we continue with that program and obtain asymptotic expansions between the fourth level and the third level: we derive 16 asymptotic expansions of the Hahn, dual Hahn, continuous Hahn and continuous dual Hahn polynomials in terms of Meixner-Pollaczek, Jacobi, Meixner and Krawtchouk polynomials. From these expansions, we also derive three new limits between those polynomials. Some numerical experiments show the accuracy of the approximations and, in particular, the accuracy in the approximation of the zeros of those polynomials.
Efficient Information Retrieval by Dispatching Mobile Agents in Parallel
Authors: Wenyu Qu, Keqiu Li, Chao Zhang
Venue: Proceedings of the 2008 International Conference on Multimedia and Ubiquitous Engineering (2008)

Due to the explosive growth of the WWW and the increasing amount of data available via the Internet, how to retrieve desired information from the Internet with high efficiency and good effectiveness is of great importance. In this paper, we propose an information retrieval model based on mobile agent technology. Theoretical analysis on the time complexity is also provided. Experiments are conducted on the performance of the proposed approach comparing with two existing approaches. Our approach well utilize mobile agents' inherent merits and provide useful tools for efficient information retrieval.
Electric and electronic circuit analysis with millman theorem
Authors: Vahé Nerguizian, Mustapha Rafaf, Chahé Nerguizian
Venue: Proceedings of the 9th International Conference on Circuits (2005)

In the electrical engineering curriculum, after circuit modeling, the analysis of a circuit is done using voltage-current Ohm law, Kirchhoff's laws and several theorems such as Thévenin, Norton and superposition. Moreover, to enhance the efficiency of the analysis, some methods and techniques such as voltage and current divider and mesh or node methods are used. In this paper the theorem of Millman is introduced in order to ease the analysis of some circuits and to verify the results with a second mean or tool. The application of this theorem is specifically interesting for circuits containing operational amplifiers. The pedagogical goal of this analysis approach is to give the students another tool to improve and verify the analysis of electric and electronic circuits.
Multitasking workload scheduling on flexible core chip multiprocessors
Authors: Divya P. Gulati, Changkyu Kim, Simha Sethumadhavan, Stephen W. Keckler, Doug Burger
Venue: ACM SIGARCH Computer Architecture News (2008)

While technology trends have ushered in the age of chip multiprocessors (CMP) and enabled designers to place an increasing number of cores on chip, a fundamental question is what size to make each core. Most current commercial designs are symmetric CMPs in which each core is identical and range from a relatively simple RISC pipeline to a large and complicated out-of-order x86 core. When the granularity of parallelism in the tasks matches the granularity of the processing cores, a CMP will be at its most efficient. To adjust the granularity of a core to the tasks running on it, recent research has proposed flexible-core chip multiprocessors, which typically consist of a number of small processing cores that can be aggregated to form larger logical processors. These architectures introduce a new resource allocation and scheduling problem which must determine how many logical processors should be configured, how powerful each processor should be, and where/when each task should run. This paper introduces and motivates this new scheduling problem, describes the challenges associated with it, and examines and evaluates several algorithms (amenable to implementation in an operating system) appropriate for such flexible-core CMPs. We also describe how scheduling for flexible-core architectures differs from scheduling for fixed multicore architectures, and compare the performance of flexible-core CMPs to both symmetric and asymmetric fixed-core CMPs.
Generalized Krylov recycling methods for solution of multiple related linear equation systems in electromagnetic analysis
Authors: Zuochang Ye, Zhenhai Zhu, Joel R. Phillips
Venue: Proceedings of the 45th annual Design Automation Conference (2008)

In this paper we propose methods for fast iterative solution of multiple related linear systems of equations. Such systems arise, for example, in building pattern libraries for interconnect parasitic extraction, parasitic extraction under process variation, and parameterized interconnect characterization. Our techniques are based on a generalized form of "recycled" Krylov subspace methods that use sharing of information between related systems of equations to accelerate the iterative solution. Experimental results on electromagnetics problems demonstrate that the proposed method can achieve a speed-up of 5X~30X compared to direct GMRES applied sequentially to the individual systems. These methods are generic, fully treat nonlinear perturbations without approximation, and can be applied in a wide variety of application domains outside electromagnetics.
Complementing approaches in ERP effort estimation practice: an industrial study
Authors: Maya Daneva
Venue: Proceedings of the 4th international workshop on Predictor models in software engineering (2008)

Projects implementing enterprise resource planning (ERP) solutions are characterized by specific context factors such as high level of reuse, scope of the ERP modules, interdependent functionality, and use of vendor-specific standard implementation method, all of which impose risks known to cause various degrees of project failure. We suggest a remedy to this issue by tackling it from a portfolio management perspective. Our solution rests on earlier work by other authors and is a combination of a classic cost estimation method (COCOMO II), a Monte Carlo simulation process, and a portfolio management model. We report on the results of a case study done in a company site in the telecommunication sector.
Reliability study of AlTi/TiW on polysilicon contacts for high temperature sensors
Authors: A. Andrei, C. Malhaire, S. Brida, J. M. Dujardin, D. Barbier, O. Legras
Venue: Microsystem Technologies (2005)

This paper deals with the reliability of metal on polysilicon gauges for sensors operating in harsh environments. Particular test structures and characterization equipment have been developed in order to study AlTi/TiW on highly doped polysilicon contact resistance behaviour and long-term stability. Finite element modeling of current density distribution over the test structures allowed accurate contact resistance extraction. Contact resistance was found to be temperature dependent, having relative good long term stability at 150&#x00b0;C with a slight (lower than 10%) trend of increase.
Learning Control Knowledge for Forward Search Planning
Authors: Sungwook Yoon, Alan Fern, Robert Givan
Venue: The Journal of Machine Learning Research (2008)

A number of today's state-of-the-art planners are based on forward state-space search. The impressive performance can be attributed to progress in computing domain independent heuristics that perform well across many domains. However, it is easy to find domains where such heuristics provide poor guidance, leading to planning failure. Motivated by such failures, the focus of this paper is to investigate mechanisms for learning domain-specific knowledge to better control forward search in a given domain. While there has been a large body of work on inductive learning of control knowledge for AI planning, there is a void of work aimed at forward-state-space search. One reason for this may be that it is challenging to specify a knowledge representation for compactly representing important concepts across a wide range of domains. One of the main contributions of this work is to introduce a novel feature space for representing such control knowledge. The key idea is to define features in terms of information computed via relaxed plan extraction, which has been a major source of success for non-learning planners. This gives a new way of leveraging relaxed planning techniques in the context of learning. Using this feature space, we describe three forms of control knowledge---reactive policies (decision list rules and measures of progress) and linear heuristics---and show how to learn them and incorporate them into forward state-space search. Our empirical results show that our approaches are able to surpass state-of-the-art non-learning planners across a wide range of planning competition domains.
Tracking in a spaghetti bowl: monitoring transactions using footprints
Authors: Animashree Anandkumar, Chatschik Bisdikian, Dakshi Agrawal
Venue: Proceedings of the 2008 ACM SIGMETRICS international conference on Measurement and modeling of computer systems (2008)

The problem of tracking end-to-end service-level transactions in the absence of instrumentation support is considered. The transaction instances progress through a state-transition model and generate time-stamped footprints on entering each state in the model. The goal is to track individual transactions using these footprints even when the footprints may not contain any tokens uniquely identifying the transaction instances that generated them. Assuming a semi-Markov process model for state transitions, the transaction instances are tracked probabilistically by matching them to the available footprints according to the maximum likelihood (ML) criterion. Under the ML-rule, for a two-state system, it is shown that the probability that all the instances are matched correctly is minimized when the transition times are i.i.d. exponentially distributed. When the transition times are i.i.d. distributed, the ML-rule reduces to a minimum weight bipartite matching and reduces further to a first-in first-out match for a special class of distributions. For a multi-state model with an acyclic state transition digraph, a constructive proof shows that the ML-rule reduces to splicing the results of independent matching of many bipartite systems.