ppxscal/embedding_network huggingface dataset:
On the existence of periodic solutions for certain differential equations
Authors: B. Mehri, M. A. Niksirat
Venue: Journal of Computational and Applied Mathematics (2005)

Here we are concerned with the problem of the existence of periodic solution for certain second and third-order nonlinear differential equations. Our method here is to consider the problem as an eigenvalue problem and treat it by the topological degree theory. In particular we establish the conditions of the existence of periodic solution first for a simpler system which is homotopic to the original system and then generalize the obtained results for the focal system. The method employed here is applicable also for a system of nonlinear differential equations just with simple modifications. Finally, we present some specific examples numerically to show that the results are valid and realizable.
The growing trend of government involvement in IT security
Authors: Christin Moore
Venue: Proceedings of the 1st annual conference on Information security curriculum development (2004)

In today's society, information security has come to the forefront of discussion, especially as terrorism, illegal corporate activities, and cyber crime incidents are increasing. The government is now taking on a larger role in determining standards and regulations for information security within IT, and it is having definite impacts and effects throughout a variety of industries. From the Gramm-Leach Bliley Act, to Sarbanes-Oxley, to HIPAA, the government continues to pass legislation that promotes some control over securing information. Initiatives continue at present to further this influence into more security areas as well. Impacts to corporations involve updating architecture, policy, and integrating systems. Effects to organizations are both positive and negative, but the question must be raised as to what the true implications of government involvement entail, and whether it is a positive or negative trend.
On the minimum size of some minihypers and related linear codes
Authors: Tatsuya Maruta, Ivan N. Landjev, Assya Rousseva
Venue: Designs, Codes and Cryptography (2005)

We denote by mr, q(s) the minimum value of f for which an {f; θr-2 + s; r, q}-minihyper exists for r ≥ 3, 1 ≤ s ≤ q - 1, where θj = (qj+1 - 1)/(q - 1). It is proved that m3, q(S) = θ1 (θ1 + s) for many cases (e.g., for all q ≥ 4 when s ≤ √q-1) and that mr, q (s) ≥ θr-1 + sθ1 + q for 1 ≤ s ≤ q-1, q ≥ 3, r ≥ 4. The nonexistence of some [n, k, n + s - qk-2]q codes attaining the Griesmer bound is given as an application.
Explicit Solution of a Stochastic, Irreversible Investment Problem and Its Moving Threshold
Authors: Maria B. Chiarolla, Ulrich G. Haussmann
Venue: Mathematics of Operations Research (2005)

We consider a firm producing a single consumption good that makes irreversible investments to expand its production capacity. The firm aims to maximize its expected total discounted real profit net of investment on a finite horizonT. The capacity is modeled as a controlled ItÃ´ process where the control is the real investment, which is not necessarily a rate, but more generally a monotone process. The result is a singular stochastic control problem. We introduce the associated optimal stopping problem, that is "the optimal cost of not investing." Its variational formulation turns out to be a parabolic obstacle problem, which we explicitly solve in the case of Constant Relative Risk Aversion CRRA production functions. The moving free boundary is the threshold at which the shadow value of installed capital exceeds the capital's replacement cost. Then we use the equation of the free boundary to evaluate the optimal investment policy and its corresponding optimal profits.
PC Note
Authors: Eugene Styer
Venue: ACM SIGICE Bulletin (1996)

In this fifth installment in the series, we will start looking at instructions added by the 286 through the Pentium processors. Many of the new instructions are used only (or mostly) by the operating system when running protected mode programs. I will identify these instructions with the label (system). Because of this, the first thing I am going to describe is how protected mode works.
Tilt Rotor Aeromechanics Phenomena in Low Speed Flight
Authors: Mark A. Potsdam, Mark J. Silva
Venue: Proceedings of the 2004 Users Group Conference (2004)

This work investigates important aeromechanics phenomena affecting the V-22 tilt rotor in low speed sideward flight or while hovering in quartering or crosswind conditions. These phenomena, such as pitch-up with sideslip and increased power required in sideward flight, were identified during V-22 critical azimuth flight testing and impacted handling qualities in this flight regime. High fidelity, dynamic, unsteady, Navier-Stokes computational fluid dynamics (CFD) calculations are presented and compared with flight test data. CFD predicts the flight test trends as a function of wind direction, in good agreement with data. Detailed investigation clearly shows the interaction of the rotor wake with the airframe as the major cause of the aeromechanics phenomena seen on the V-22. Identification of the underlying flowfield physics allows investigation of options for alleviation and prediction of future tilt rotor configurations.
SnapFind: Brute Force Interactive Image Retrieval
Authors: Larry Huston, Rahul Sukthankar, Derek Hoiem, Jiaying Zhang
Venue: Proceedings of the Third International Conference on Image and Graphics (2004)

SnapFind is an image retrieval system that enables efficient interactive search of large data sets by exploiting active disk technology. In contrast to earlier approaches, where data is typically pre-indexed forefficient retrieval according to a fixed scheme, SnapFind provides users with the flexibility to search non-indexed data in a brute force manner. The query is translated into a customized searchlet that is executed in parallel by processors near the storage devices. This enables the majority of irrelevant images to be discarded where they are stored. Partial results are displayed during search execution allowing users to interactively refine the query without waiting for search termination. This paper argues that algorithms with user-adjustable parameters are preferable to black-box image retrieval techniques.
Fast Sweeping Methods for Static Hamilton--Jacobi Equations
Authors: Chiu-Yen Kao, Stanley Osher, Yen-Hsi Tsai
Venue: SIAM Journal on Numerical Analysis (2004)

We propose a new sweeping algorithm which discretizes the Legendre transform of the numerical Hamiltonian using an explicit formula. This formula yields the numerical solution at a grid point using only its immediate neighboring grid values and is easy to implement numerically. The minimization that is related to the Legendre transform in our sweeping scheme can either be solved analytically or numerically. We illustrate the efficiency and accuracy approach with several numerical examples in two and three dimensions.
Parametrization of approximate algebraic surfaces by lines
Authors: Sonia Pérez-Díaz, Juana Sendra, J. Rafael Sendra
Venue: Computer Aided Geometric Design (2005)

In this paper we present an algorithm for parametrizing approximate algebraic surfaces by lines. The algorithm is applicable to ε-irreducible algebraic surfaces of degree d having an ε-singularity of multiplicity d - 1, and therefore it generalizes the existing approximate parametrization algorithms. In particular, given a tolerance ε > 0 and an ε-irreducible algebraic surface V of degree d, the algorithm computes a new algebraic surface V-, that is rational, as well as a rational parametrization of V-. In addition, in the error analysis we show that the output surface V- and the input surface V are close. More precisely, we prove that V- lies in the offset region of V at distance, at most, O(ε1/(2d)).
TCP congestion window evolution and spatial reuse in MANETs: Research Articles
Authors: S. Papanastasiou, M. Ould-Khaoua
Venue: Wireless Communications Mobile Computing (2004)

A number of recent research studies have explored ways to improve TCP throughput in mobile ad hoc networks by improving its interaction with the IEEE 802.11 medium access control (MAC) layer. In particular, the hidden terminal effects caused by interference can impact TCP performance dramatically and have been dealt with in the past by restricting the maximum sending window size. We have developed a TCP variant, which instead, adjusts the sending rate increase to achieve competitive goodput for TCP connections. Extensive simulation experiments indicate that a slower sending rate increase during the congestion avoidance phase of TCP leads to improved performance for TCP Reno while eliminating the negative effects inherent in restricting the maximum sending window size. This work discusses the applicability of our TCP oriented solution to the hidden terminal effect, includes a performance comparison against existing solutions and discusses its performance merits under various mobility conditions. Copyright &copy; 2004 John Wiley & Sons, Ltd.
Use and evaluation of the ALEKS interactive tutoring system
Authors: Michael E. Hardy
Venue: Journal of Computing Sciences in Colleges (2004)

Instructors of development math have long desired a way to individualize instruction allowing each student to focus on material which he or she does not already know but is ready to learn. Since Fall semester of 2002, many of the developmental math sections at the author's university have used ALEKS, a web based intelligent tutoring program to achieve this end. (ALEKS stands for 'Assessment and LEarning in Knowledge Spaces.') This paper briefly describes the ALEKS system and the data that can be collected from it in order to determine its effectiveness. It describes an analysis of data collected from 135 students who used the program in Intermediate Algebra during the Fall semester of 2002 discusses ways to improve data collection to better answer questions about the effectiveness of the system.
Feature Kernel Functions: Improving SVMs Using High-Level Knowledge
Authors: Qiang Sun, Gerald DeJong
Venue: Proceedings of the 2005 IEEE Computer Society Conference on Computer Vision and Pattern Recognition (CVPR'05) - Volume 2 - Volume 02 (2005)

Kernel functions are often cited as a mechanism to encode prior knowledge of a learning task. But it can be difficult to capture prior knowledge effectively. For example, we know that image pixels of a handwritten character result from a few strokes from a single writing implement; it is not clear how to express this in a kernel function. We investigate an Explanation Based Learning (EBL) paradigm to generate specialized kernel functions. These embody novel high-level features that are automatically constructed from the interaction of prior knowledge and training examples. Our empirical results showed that the performance of the resulting SVM surpasses that of a conventional SVM on the challenging task of classifying handwritten Chinese characters.
The image analysis system with Adaptive Component
Authors: Chul Choi, Young Kwan Choi, Chang-Chun Park
Venue: Proceedings of the 2004 international symposium on Information and communication technologies (2004)

This paper proposes ACA (Adaptive Component Analysis) as a method for feature extraction and analysis of the content-based image retrieval system. Retrieval measurement is a standard indicating how important the value of a relevant feature is to image retrieval. This process of analysis is called ACA (Adaptive Component Analysis) and the result extracted through ACA becomes an adaptive component for retrieval or statistical/mechanical learning. From the viewpoints of algorithm and system, ACA is a middle stage for content-based image retrieval and it purposes to improve the retrieval speed and performance.
Secure Mutual Authentication for Ad hoc Wireless Networks
Authors: Byung-Gi Kim, Sang-Sun Hong
Venue: The Journal of Supercomputing (2005)

As wireless LANs and wireless terminals deployed, security and authentication, among other things, became important. We propose a mutual authentication scheme for access security among wireless terminals. We use user identification together with hardware identification in creating a certificate for the wireless access. And authentication is performed based on the certificate. It enables reliable user authentication, establishment and check of access rights (when a terminal is managed in connection with a network gateway), Peer-to-Peer access with authentication, and international roaming of terminals.
Book review: Intelligent Tutoring Sytems---Lessons Learned by Joseph Psotka, L. Dan Massey, and Sharon Mutter (Lawrence Erlbaum Assocs. Inc.)
Venue: Issue 107 (January 1989) (1989)

Introduction For many years the Sleeman/Brown text on inteligent tutoring systems was the sole offering in the field. During the past year a number of new ITS texts have been released. Although some of them, (e.g. Wenger, 1987) tie theory to application, many of them are redundant in their focus on the early systems and/or their computer science orientation. Furthermore, existing texts rarely mention the decade of relevant research and development in instructional design and computer-based training. This book changes things.
Polarization Multiplexing for Bidirectional Imaging
Authors: Oana G. Cula, Kristin J. Dana, Dinesh K. Pai, Dongsheng Wang
Venue: Proceedings of the 2005 IEEE Computer Society Conference on Computer Vision and Pattern Recognition (CVPR'05) - Volume 2 - Volume 02 (2005)

Our goal is to incorporate polarization in appearance-based modeling in an efficient and meaningful way. Polarization has been used in numerous prior studies for separating diffuse and specular reflectance components, but in this work we show that it also can be used to separate surface reflectance contributions from individual light sources. Our approach is called polarization multiplexing and it has significant impact in appearance modeling and bidirectional imaging where the image as a function of illumination direction is needed. Multiple unknown light sources can illuminate the scene simultaneously, and the individual contributions to the overall surface reflectance can be estimated. To develop the method of polarization multiplexing, we use a relationship between light source direction and intensity modulation. Inverting this transformation enables the individual intensity contributions to be estimated. In addition to polarization multiplexing, we show that phase histograms from the intensity modulations can be used to estimate scene properties including the number of light sources.
Formalisations of Capabilities for BDI-Agents
Authors: Lin Padgham, Patrick Lambrix
Venue: Autonomous Agents and Multi-Agent Systems (2005)

Intentional agent systems are increasingly being used in a wide range of complex applications. Capabilities has recently been introduced into some of these systems as a software engineering mechanism to support modularity and reusability while still allowing meta-level reasoning. This paper presents possible formalisations of capabilities within the framework of beliefs, goals and intentions and indicates how capabilities can affect agent reasoning about its intentions. We define a style of agent commitment which we refer to as a self-aware agent which allows an agent to modify its goals and intentions as its capabilities change. We also indicate which aspects of the specification of a BDI interpreter are affected by the introduction of capabilities and give some indications of additional reasoning which could be incorporated into an agent system on the basis of both the theoretical analysis and the existing implementation.
DEQUE: querying the deep web
Authors: Denis Shestakov, Sourav S. Bhowmick, Ee-Peng Lim
Venue: Data Knowledge Engineering (2005)

In this paper, we present a system called DEQUE (Deep WEb QUery SystEm) for modeling and querying the deep Web. We propose a data model for representing and storing HTML forms, and a web form query language called DEQUEL for retrieving data from the deep Web and storing them in the format convenient for additional processing. Our system is able to query forms (single and consecutive) with input values from relations as well as from result pages (results of querying web forms). We present a novel approach in modeling of consecutive forms and introduce the concept of the super form. A prototype system has been implemented on a SUN workstation working under Solaris 2.7 using Perl version 5.005_2 and employing MySQL (version 3.23.49) DBMS as the data storage.
General Proxy-Based Haptics for Volume Visualization
Authors: Karljohan Lundin, Bjorn Gudmundsson, Anders Ynnerman
Venue: Proceedings of the First Joint Eurohaptics Conference and Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems (2005)

We present a general, proxy-based approach to volume haptics founded upon the notion of ýhaptic primitivesý. Haptic modes each representing a different aspect of volumetric data, are created by defining sets of haptic primitives which reflect the local properties of the data. The proxy position for every time-frame in the haptic loop is found by balancing the force feedback in the haptic instrument with the force from the haptic primitives involved. The presented general framework allows for rapid development of haptic feedback modes for volumetric data. The approach also allows, in contrast to previous work on proxy-based volume haptics, combination of non-orthogonal constraints and thus allows free combination of various modes in haptic exploration of multivariate data. We demonstrate the effectiveness of our approach through the implementation of five different haptic modes.
A Bayesian Approach to Unsupervised Feature Selection and Density Estimation Using Expectation Propagation
Authors: Shaorong Chang, Nilanjan Dasgupta, Lawrence Carin
Venue: Proceedings of the 2005 IEEE Computer Society Conference on Computer Vision and Pattern Recognition (CVPR'05) - Volume 2 - Volume 02 (2005)

We propose an approximate Bayesian approach for unsupervised feature selection and density estimation, where the importance of the features for clustering is used as the measure for feature selection. Traditional maximum-likelihood (ML) model-parameter optimization schemes estimate the feature saliencies for a fixed model structure (i.e., a fixed number of clusters). In practice, the number of clusters present in the data for mixture-based modeling is unknown. In an ML framework, the number of clusters typically needs to be ascertained prior to estimating the feature saliencies. We propose a density estimation scheme that addresses model complexity (number of clusters present) and model-parameter estimation (feature saliencies) in a single optimization framework. The approximate Bayesian approach presented here, based on the expectation propagation method, obtains a full posterior distribution on the saliency of the features, along with full posterior distribution of other model parameters (including the number of clusters) that represent the underlying statistics of the data. The performance of the algorithm, is analyzed based on its ability to identify the features salient for clustering the multivariate data.
Autonomous and Dynamic Web Service Composition in Wireless Grids
Authors: Haoming Guo, Mei Yang, Xiaolong Wu, Yingtao Jiang, Shilong Ma, Guoshun Hao
Venue: Proceedings of the International Conference on Information Technology: Coding and Computing (ITCC'05) - Volume II - Volume 02 (2005)

In combination of web service and wireless technology, grid computing is evolved into a de facto standard for shared-resource computations. Although numerous efforts have been made on the construction of grid systems, stateless web service composition has not been addressed sufficiently in grid environment, which is usually service-conscious. This paper attempts to address this issue through a novel work flow model which not only builds tasks through web services, also handles state control through the grid platform. Based on this model, a grid system can ultimately compose web services and give user a better tool for supercomputing
Lattice Image Processing: A Unification of Morphological and Fuzzy Algebraic Systems
Authors: Petros Maragos
Venue: Journal of Mathematical Imaging and Vision (2005)

This paper explores some aspects of the algebraic theory of mathematical morphology from the viewpoints of minimax algebra and translation-invariant systems and extends them to a more general algebraic structure that includes generalized Minkowski operators and lattice fuzzy image operators. This algebraic structure is based on signal spaces that combine the sup-inf lattice structure with a scalar semi-ring arithmetic that possesses generalized `additions' and ¿-`multiplications'. A unified analysis is developed for: (i) representations of translation-invariant operators compatible with these generalized algebraic structures as nonlinear sup-¿ convolutions, and (ii) kernel representations of increasing translation-invariant operators as suprema of erosion-like nonlinear convolutions by kernel elements. The theoretical results of this paper develop foundations for unifying large classes of nonlinear translation-invariant image and signal processing systems of the max or min type. The envisioned applications lie in the broad intersection of mathematical morphology, minimax signal algebra and fuzzy logic.
On the Use of Augmented Lagrangians in the Solution of Generalized Semi-Infinite Min-Max Problems
Authors: Elijah Polak, Johannes O. Royset
Venue: Computational Optimization and Applications (2005)

We present an approach for the solution of a class of generalized semi-infinite optimization problems. Our approach uses augmented Lagrangians to transform generalized semi-infinite min-max problems into ordinary semi-infinite min-max problems, with the same set of local and global solutions as well as the same stationary points. Once the transformation is effected, the generalized semi-infinite min-max problems can be solved using any available semi-infinite optimization algorithm. We illustrate our approach with two numerical examples, one of which deals with structural design subject to reliability constraints.
The Connectedness of Some Varieties and the Deligne-Simpson Problem
Authors: Vladimir Petrov Kostov
Venue: Journal of Dynamical and Control Systems (2005)

The Deligne--Simpson problem (DSP) (respectively, the weak DSP) is formulated as follows: give necessary and sufficient conditions for the choice of the conjugacy classes Cj ¿ GL(n, ¿) or cj ¿ gl(n, ¿) so that there exist irreducible (respectively, with trivial centralizer) (p + 1)-tuples of matrices Mj ¿ Cj or Aj ¿ cj satisfying the equality M1 ... Mp+1 = I or A1 + ... + Ap+1 = 0. The matrices Mj and Aj are interpreted as monodromy operators of regular linear systems and as matrices-residua of Fuchsian ones on the Riemann sphere. For ((p + 1))-tuples of conjugacy classes one of which is with distinct eigenvalues we prove that the variety {(M1, ..., Mp+1) | Mj ¿ Cj, M1 ... Mp+1 = I} or {(A1, ..., Ap+1) | Aj ¿ cj, A1 + ... + Ap+1 = 0| is connected if the DSP is positively solved for the given conjugacy classes and give necessary and sufficient conditions for the positive solvability of the weak DSP.
TWO METHODS FOR PRODUCING DISCRIMINABLE COLOUR SETS FOR COMPUTER DISPLAYS
Authors: Darren Van Laar, Richard Flavell
Venue: ACM SIGCHI Bulletin (1991)

One of the most important decisions facing designers of colour displays is how to choose a colour, or set of colours for a display when the possible number or combination of choices is often in the millions. One way of determining colours is on the basis of how different they look, with colours that are easily told apart being necessary for many tasks such as reading, search and identification.