ppxscal/embedding_network huggingface dataset:
The Numerical Solution of a Challenging Class of Turning Point Problems
Authors: Ping Lin, R. E. O'Malley,  Jr.
Venue: SIAM Journal on Scientific Computing (2003)

A curious class of challenging singularly perturbed turning point problems is considered and properties of the solutions to corresponding initial value problems are studied. The solutions are exponentially small near the turning point and become unstable after passing it. Various state-of-the-art codes available in MATLAB as well as one-step and multistep methods on a uniform mesh are tested. By examining a number of examples, one finds that the usual error control strategies may not work when the solution near the turning point is small, while one-step and multistep methods on a uniform mesh work only for a moderately small perturbation parameter. A scale amplification transformation, however, seems to give the correct solution when the solution is extremely small and/or zero at the turning point. Extensions to problems with more equilibria are also briefly considered.
High code rate, low-density parity-check codes with guaranteed minimum distance and stopping weight
Authors: John Andrew Miller
Venue:  (2003)

Recent schemes have been proposed for magnetic recording that combine a maximum a posteriori probability channel detector for a partial response channel and a low-density parity-check (LDPC) code. The signal processing for these schemes uses the message passing algorithm for iteratively sharing information between the channel detector and the LDPC decoder. At high signal to noise ratios, the sector-error probability of a scheme using an LDPC code is related to the minimum distance of the code. Because these schemes use an LDPC code whose minimum distance has not been characterized, the sector-error probability of these schemes also has not been characterized for high signal to noise ratios. We show that an analysis of isomorphic classes of binary matrices results in new design criteria for an LDPC code with a guaranteed minimum distance. We present a new scheme that uses an LDPC code synthesized using these design criteria. We also present synthesis algorithms that select columns of a parity-check matrix in a random manner resulting in an LDPC code with a minimum distance of at least eight. We show that search algorithms found short block length or high code rate, LDPC codes using either a synthesis algorithm that uses random selection with replacement or a synthesis algorithm that uses random selection without replacement. By using a truncation of the union bound, we show that the new scheme meets the standard sector-error probability requirement for disk drives. We also show via computer simulation that, for low signal to noise ratios, the new scheme has a low sector-error probability. Finally, we present new design criteria for a class of LDPC codes that apply to the binary erasure channel and partial response systems. We define an LDPC code with a stopping weight W as an LDPC code described by a parity-check matrix that contains a set of W columns (with special properties). We show that search algorithms using the new design criteria found short block length or high code rate LDPC codes with a guaranteed minimum stopping weight.
Analytical Expressions For Static Characteristics of Submicron CMOS Inverters
Authors: S. Ulman
Venue: Proceedings of the 17th International Conference on VLSI Design (2004)

In this paper we derive analytical &physical based expressions to characterize thestatic behavior of the submicron CMOS inverter.The model expressions include formulae toestimate the logic threshold voltage and noisemargins of submicron CMOS inverters.Theseexpressions have been derived from a smallgeometry physics based model borrowed from[1] due to its simple mathematical form, highaccuracy to plot the I-V characteristics ofMOSFETs right up to 0.1µ, inclusion of smallgeometry effects like DIBL, channel lengthmodulation, velocity saturation mobilitydegradation, etc and its physical basis.Theseexpression shows an error of 5% on an averagewhen benchmarked against numerical modelslike BSIM 3.
Analysis of variable-stepsize linear multistep methods with special emphasis on symmetric ones
Authors: B. Cano, A. Durán
Venue: Mathematics of Computation (2003)

In this paper we deal with several issues concerning variable-stepsize linear multistep methods. First, we prove their stability when their fixed-stepsize counterparts are stable and under mild conditions on the stepsizes and the variable coefficients. Then we prove asymptotic expansions on the considered tolerance for the global error committed. Using them, we study the growth of error with time when integrating periodic orbits. We consider strongly and weakly stable linear multistep methods for the integration of first-order differential systems as well as those designed to integrate special second-order ones. We place special emphasis on the latter which are also symmetric because of their suitability when integrating moderately eccentric orbits of reversible systems. For these types of methods, we give a characterization for symmetry of the coefficients, which allows their construction, and provide some numerical results for them.
Assessment of blocking performance in unidirectional and bi-directional wavelength routed ring networks
Authors: Mário M. Freire, Henrique J. A. da Silva
Venue: Journal of High Speed Networks (2003)

In this paper, we present a comparison of the blocking performance in unidirectional and hi-directional wavelength routed ring networks. This performance comparison reveals that, for the same load per node and equal number of wavelengths per link, the performance of a unidirectional ring with N nodes is very close to the performance of a bi-directional ring with 4N nodes. This comparison also suggests that, for the same number of nodes and equal number of wavelengths per link, the performance of a unidirectional ring network with a load per node of ρ is similar to the performance of a bi-directional ring network with a load per node of 4ρ. An explanation is presented for this fourfold capacity increase of bi-directional rings over unidirectional rings, regarding number of nodes or loads per node.
Building XML statistics for the hidden web
Authors: Ashraf Aboulnaga, Jeffrey F. Naughton
Venue: Proceedings of the twelfth international conference on Information and knowledge management (2003)

There have been several techniques proposed for building statistics for static XML data. However, very little work has been done in the area of building XML statistics for data sources that export XML views of data that is stored in relational or other databases. For such data sources, we need statistics that are built in an on-line manner, by observing the XML queries to the data sources and their results. In this paper, we present a technique for building on-line XML statistics by observing the XPath queries issued to a data source and their result sizes. These XPath queries select parts of the virtual XML document representing the XML view of the data at the data source. We convert these XPath queries to a more abstract and generalized form that we call annotated path expressions. We present a technique for storing these annotated path expressions and information about their selectivity for use in estimating the selectivity of future XPath queries. We also present an experimental evaluation of our proposed approach.
Non-blocking atomic commit in asynchronous distributed systems with failure detectors
Authors: Rachid Guerraoui
Venue: Distributed Computing (2002)

This paper addresses the Non-Blocking Atomic Commit (NB-AC) problem in asynchronous distributed systems augmented with failure detectors. We first show that, in these systems, NB-AC and Consensus are incomparable. Roughly speaking, there is a failure detector that solves NBAC but not Consensus and a failure detector that solves Consensus but not NB-AC. Then we introduce the Anonymously Perfect failure detector ?P. We show that, to solve NB-AC, ?P is necessary (while P is not), whereas ?P + ♦S is sufficient when a majority of the processes are correct. We draw from our results some observations on the practical solvability of NB-AC.
The effect of training set distributions for supervised learning artificial neural networks on classification accuracy
Authors: Steven Walczak, Irena Yegorova, Bruce H. Andrews
Venue: Information management: support systems & multimedia technology (2003)

Neural networks have been repeatedly shown to outperform traditional statistical modeling techniques for both discriminant analysis and forecasting. While questions regarding the effects of architecture, input variable selection, learning algorithm, and size of training sets on the neural network model's performance have been addressed, very little attention has been focused on distribution effects of training and out-of-sample populations on neural network performance. This article examines the effect of changing the population distribution within training sets for estimated distribution density functions, in particular for a credit risk assessment problem.
Distributive idempotent uninorms
Authors: D. Ruiz, J. Torrens
Venue: International Journal of Uncertainty, Fuzziness and Knowledge-Based Systems (2003)

A characterization of all idempotent uninorms satisfying the distributive property is given. The special cases of left-continuous and right-continuous idempotent uninorms are presented separately and it is also proved that all idempotent uninorms are autodistributive. Moreover, all distributive pairs of idempotent uninorms (pairs U1, U2 such that U1 is distributive over U2 and U2 is distributive over U1) are also characterized.
Virtualisations and its role in business
Authors: Jerzy Kisielnicki
Venue: Managing IT in government business & communities (2003)

This chapter presents some of the aspects of virtualisation and its role in modern society. In today's world, a controlled virtualisation process creates enormous opportunity for economic growth of those countries and organisations, which, so far, due to various restrictions, have had no chance to become competitive in the global market. Those people and organisations that know how to make use of the opportunities presented by virtualisation may become more effective in business. Moreover, virtualisation creates the best options for intellectual enterprise development. Virtualisation is a very complex process. The author would like to discusses both the positive impact virtualisation can have on society and also some dangers or problems.
Drawing marks, acts, and reacts: Toward a computational sketching interface for architectural design
Authors: Ellen Yi-luen Do
Venue: Artificial Intelligence for Engineering Design, Analysis and Manufacturing (2002)

Architects use sketching and diagramming in their design process to perform functional reasoning, formal arrangements, analogy transfer, structure mapping, and knowledge acquisition. This paper describes a research framework of the author's efforts in the studies of design drawings and the building of computational sketching tools to support the early conceptual design process in architecture. The first part of the paper discusses empirical studies conducted to determine or guess a designer's thought process from sketches and thus identifies domain-specific graphical symbols. It proposes a reasoning process framework of drawing marks, acts, and reacts. The second part of the paper illustrates how design support tools could be developed based on these concepts and describes the various applications of the study, such as indexing and retrieving of design drawings or images based on the recognition of geometric shapes and the spatial relationships among them.
Dealing with Uncertainties in Building Scenarios for the Development of Mobile Services
Authors: Elisabeth van de Kar, Patrick van der Duin
Venue: Proceedings of the Proceedings of the 37th Annual Hawaii International Conference on System Sciences (HICSS'04) - Track 3 - Volume 3 (2004)

The mobile telecommunications industry needs to develop services for the mobile data market, not only to regain their investments in licenses but also to stay competitive in the future. The current turbulence on markets, politics and technology is generating many uncertainties with regard to, for instance, user needs, dominant technology and the role of different market players. The goal of this paper is to show how to apply the scenario method for coping with these uncertainties in the development of mobile data services. We argue that mobile service providers should pay more and permanent attention to these uncertainties when developing new mobile data services.In 2001 a Dutch consortium (named MOBUS), consisting of representatives of mobile service providers, research institutes, universities, telecommunication suppliers and financial companies, undertook a project with the goal of defining possible new services for the mobile telecommunications industry. To develop a view on the future, a set of four scenarios for the year 2005 was developed. These scenarios were not only made to gain insight into possible new mobile data services but also into how users might use these services and which technologies might be available. An important element of the project was a list of uncertainties produced by the consortium that formed the basis of the scenarios. These uncertainties were evaluated two years later to find out whether these uncertainties are still valid, why theychanged and if new uncertainties have come up. Two items were considered to be not uncertain anymore, i.e. mobile services will be multimedia based and mobile payment is available. On the other hand 26 new uncertainties were identified. Therefor all market parties involved in mobile data services development should reconsider uncertainties on a regular basis with different teams of experts.
Monotonic scaling of the KPZ growth with quenched disorder
Authors: H. Katsuragi, H. Honjo
Venue: Proceedings of the international conference on Computational methods in sciences and engineering (2003)

Multiaffine analysis is applied to the KPZQ (Kardar-Parisi-Zhang growth with Quenched disorder) model. In the previous work, we have found that the BDP (Ballistic Deposition growth with Power-law noise) model has a multiaffinity, and power-law noise tends to break the KPZ universality. In this paper, we report on the monotonic self-affine scaling of the KPZQ model. It is confirmed that the KPZ universality holds in higher order exponents. This implies that the BDP model and the KPZQ model can be classified by the multiaffine analysis.
Managing QoS for Multimedia Applications in the Differentiated Services Environment
Authors: Manish Mahajan, Manish Parashar
Venue: Journal of Network and Systems Management (2003)

The overall quality of network connections has a significant impact on the performance of networked applications. As a result, Quality-of-Service (QoS) management for networked multimedia applications over IP is a significant and immediate challenge. While differentiated services (DiffServ) provide a sense of resource allocation and QoS, they do not guarantee QoS. This paper presents the design, implementation and evaluation of a content-aware bandwidth broker (CABB) that manages QoS for multimedia applications in a DiffServ environment. CABB allocates network resources to multimedia flows based on client requirements, the adaptability of the application, and its tolerance to network level parameters such as bandwidth, delay, and latency. It has been implemented and evaluated using the NS-2 simulator toolkit. Evaluations show that CABB improves network resource allocations and increases overall throughput. Furthermore multimedia application flows are better managed and controlled, improving perceived QoS and avoiding possible congestion at core routers.
Trees and jumps and real roots
Authors: Werner Krandick
Venue: Journal of Computational and Applied Mathematics (2004)

When the nodes of a tree are visited in depth-first order there are occasional jumps from a deeper level of the tree to a higher level. On the set of all full binary trees with a given number of nodes there is about 1 jump for every 2 internal nodes, and the average jump distance is about 2 levels. These averages are close to averages for trees that arise in polynomial real root isolation.
Simulating rational social normative trust, predictive trust, and predictive reliance between agents
Authors: Maj Tuomela, Solveig Hofmann
Venue: Ethics and Information Technology (2003)

A program for the simulation of rational social normative trust, predictive `trust,' and predictive reliance between agents will be introduced. It offers a tool for social scientists or a trust component for multi-agent simulations/multi-agent systems, which need to include trust between agents to guide the decisions about the course of action. It is based on an analysis of rational social normative trust (RSNTR) (revised version of M. Tuomela 2002), which is presented and briefly argued. For collective agents, belief conditions for collective agency should be added. For the various forms of trust agents must have (at least) subjectively rational reasons to believe that the conditions of the trust account are fulfilled. A list of such reasons (of varied weights), e.g., given by empirical research, can manually be built into a parameter file or be generated by a calling program in a fixed format. From this list of reasons the program randomly generates a belief base for the agents of the artificial society. Reasons can be chained together so that one set of reasons satisfies several belief conditions. The program checks if the conditions are fulfilled for the artificial agents' social normative trust/predictive `trust'/`predictive reliance' in another agent that he will perform an action X. Each outcome is logged to a result file. In conclusion we discuss various aspects of the application of a trust component of the suggested kind in empirical research, social simulation, and multi-agent systems.
RTGEN: an algorithm for automatic generation of reservation tables from architectural descriptions
Authors: Peter Grun, Ashok Halambi, Nikil Dutt, Alex Nicolau
Venue: IEEE Transactions on Very Large Scale Integration (VLSI) Systems (2003)

Reservation Tables (RTs) have long been used to detect conflicts between operations that simultaneously access the same architectural resource. Traditionally, these RTs have been specified explicitly by the designer. However, the increasing complexity of modern processors makes the manual specification of RTs cumbersome and error prone. Furthermore, manual specification of such conflict information is infeasible for supporting rapid architectural exploration. In this paper, we present an algorithm to automatically generate RTs from a high-level processor description with the goal of avoiding manual specification of RTs, resulting in more concise architectural specifications and also supporting faster turn-around time in design space exploration. We demonstrate the utility of our approach on a set of experiments using the TI C6201 very long instruction Word digital signal processor and DLX processor architectures, and a suite of multimedia and scientific applications.
Discrete Absorbing Boundary Conditions for Schrödinger-Type Equations. Construction and Error Analysis
Authors: Isaias Alonso-Mallo, Nuria Reguera
Venue: SIAM Journal on Numerical Analysis (2003)

When a partial differential equation in an unbounded domain is solved numerically, it is necessary to introduce artificial boundary conditions. In this paper, a general class of absorbing boundary conditions is constructed for one-dimensional Schrödinger-type equations discretized in space by finite differences. For this, rational approximations to the transparent boundary conditions are used. We study the simplest case in detail, obtaining an estimate for the full discrete error and showing that the discrete problem is weakly unstable. Moreover, we show numerically that the discrete problems associated to higher order absorbing boundary conditions are more unstable. Several numerical experiments confirm the results previously obtained.
The grobner fan and grobner walk for modules
Authors: Ruth Lynn Auerbach
Venue:  (2003)

This dissertation extends the theory of the Gr&ouml;bner fan and Gr&ouml;bner walk for ideals in polynomial rings to the case of submodules of free modules over a polynomial ring. The Gr&ouml;bner fan for an ideal creates a correspondence between a pair consisting of a cone in the fan and a point in the support of the cone and a pair consisting of a leading term ideal (or equivalently, a reduced marked Gr&ouml;bner basis) and a grading of the ring that is compatible with the choice of leading terms. The analog in the submodule case has pairs of a cone and a point in the fan corresponding to pairs of a leading monomial submodule (or equivalently, a reduced marked Gr&ouml;bner basis) and a grading of the free module over the ring that is compatible with the choice of leading monomials. The Gr&ouml;bner walk is the Gr&ouml;bner walk can be more efficient for Gr&ouml;bner basis computations with difficult monomial orders. In addition, the concept of a state polytope for a homogeneous ideal of a polynomial ring, which is closely related to the Gr&ouml;bner fan and is a generalization of the classical Newton polytope for a polynomial, is extended to homogeneous submodules of free modules over polynomial rings. Algorithms to generate the Gr&ouml;bner fan and the state polytope and algorithms for the Gr&ouml;bner walk are given.
Impact of reordering on the memory of a multifrontal solver
Authors: Abdou Guermouche, Jean-Yves L'Excellent, Gil Utard
Venue: Parallel Computing (2003)

This paper is concerned with the memory usage of sparse direct solvers, which depends on the ordering of the unknowns and the scheduling of the computational tasks. We study the influence of state-of-the-art sparse matrix reordering techniques on the memory usage of a multifrontal solver. Concerning the scheduling, the memory usage depends on the tree traversal and how the tasks are assigned to the processors. We analyze the memory scalability when a dynamic scheduling strategy mainly based on the balance of the workload is used. Finally we give hints to improve the parallel memory behaviour.
Practical Random Number Generation in Software
Authors: John Viega
Venue: Proceedings of the 19th Annual Computer Security Applications Conference (2003)

There is a large gap between the theory and practicefor random number generation. For example, on mostoperating systems, using /dev/random to generate a256-bit AES key is highly likely to produce a key withno more than 160 bits of security. In this paper, wepropose solutions to many of the issues that realsoftware-based random number infrastructures haveencountered. Particularly, we demonstrate thatuniversal hash functions are a theoretically appealingand efficient mechanism for accumulating entropy, weshow how to deal with forking processes withoutusing a two-phase commit, we explore better metricsfor estimating entropy and argue that systems shouldprovide both computational security and informationtheoretic security through separate interfaces.