ppxscal/embedding_network huggingface dataset:
Path selection and bandwidth allocation in MPLS networks
Authors: James E. Burns, Teunis J. Ott, Anthony E. Krzesinski, Karen E. Müller
Venue: Performance Evaluation (2003)

Multi-protocol label switching extends the IP destination-based routing protocols to provide new and scalable routing capabilities in connectionless networks using relatively simple packet forwarding mechanisms. MPLS networks carry traffic on virtual connections called label switched paths. This paper considers path selection and bandwidth allocation in MPLS networks in order to optimize the network quality of service. The optimization is based upon the minimization of a non-linear objective function which under light load simplifies to OSPF routing with link metrics equal to the link propagation delays. The behavior under heavy load depends on the choice of certain parameters. It can essentially be made to minimize maximal expected utilization, or to maximize minimal expected weighted slacks (both over all links). Under certain circumstances it can be made to minimize the probability that a link has an instantaneous offered load larger than its transmission capacity. We present a model of an MPLS network and an algorithm which optimally distributes the traffic among a set of active paths and reserves a set of back-up paths for carrying the traffic of failed or congested paths. The algorithm is an improvement of the well-known flow deviation non-linear programming method. The algorithm is applied to compute optimal LSPs for a 100-node network carrying a single traffic class. A link carrying some 1400 routes fails. The back-up paths are activated and we compare the performance of the path sets before and after the back-up paths are deployed.
Java concurrent program for the Samarandache function
Authors: David Power, Sabin Tabirca, Tatiana Tabirca
Venue: Smarandache notions (2002)

The aim of this article is to propose a Java concurrent program for the Smarandache function based on the equation S(p1k1.....psks) = max{S(p1k1,....,S(psks)}. Some results concerning the theoretical complexity of this program are proposed. Finally, the experimental results of the sequential and Java programs are given in order to demonstrate the efficiency of the concurrent implementation.
Self-orthogonal codes from symmetric designs with fixed-point-free automorphisms
Authors: Masaaki Harada, Vladimir D. Tonchev
Venue: Discrete Mathematics (2003)

In this paper, we consider a method for constructing non-binary self-orthogonal codes from symmetric designs with fixed-point-free automorphisms. All codes over GF(3) and GF(7) derived from symmetric 2-(υ,k,λ) designs with fixed-point-free automorphisms of order p for the parameters (υ,k,λ,p) = (27,14,7,3),(40,27,18,5) and (45,12,3,5) are classified. A ternary [63,20,21] code with a record breaking minimum weight is constructed from the symmetric 2-(189,48,12) design found recently by Janko. Several codes over GF(5) and GF(7) that are either optimal or have the largest known minimum weight are constructed from designs obtained from known difference sets.
Optimal flow control and routing in multi-path networks
Authors: Wei-Hua Wang, Marimuthu Palaniswami, Steven H. Low
Venue: Performance Evaluation (2003)

We propose two flow control algorithms for networks with multiple paths between each source-destination pair. Both are distributed algorithms over the network to maximize aggregate source utility. Algorithm 1 is a first order Lagrangian method applied to a modified objective function that has the same optimal solution as the original objective function but has a better convergence property. Algorithm 2 is based on the idea that, at optimality, only paths with the minimum price carry positive flows, and naturally decomposes the overall decision into flow control (determines total transmission rate based on minimum path price) and routing (determines how to split the flow among available paths). Both algorithms can be implemented as simply a source-based mechanism in which no link algorithm nor feedback is needed. We present numerical examples to illustrate their behavior.
Nondeterministic trajectories
Authors: Alexandru Mateescu, Arto Salomaa
Venue: Formal and natural computing (2002)

Trajectories have been introduced as mechanisms to control the shuffle operation, traditionally important in the study of parallelism and concurrency. A variant, nondeterministic trajectory will be introduced in this paper. It provides more leeway in the control of the shuffle operation. Ordinary trajectories will be obtained as a special case of nondeterministic ones. The paper investigates basic properties of nondeterministic trajectories, emphasizing algebraic aspects, interconnections with language theory and the property of fairness.
Variational Inclusions under State Constraints
Authors: Moulka Tamzali-Lafond
Venue: SIAM Journal on Control and Optimization (2003)

We extend variational equations of ODEs to nonconvex differential inclusions under state constraints. As an application, we provide a direct proof of the maximum principle of the Pontryagin type for an optimal control problem with state constraints.
Estimation and inversion of the effects of cell population asynchrony in gene expression time-series
Authors: Harri Lähdesmäki, Heikki Huttunen, Tommi Aho, Marja-Leena Linne, Jari Niemi, Juha Kesseli, Ron Pearson, Olli Yli-Harja
Venue: Signal Processing (2003)

We introduce several approaches to improve the quality of gene expression data obtained from time-series measurements by applying signal processing tools. Performance of the proposed methods are examined using both simulated and real yeast gene expression data. In particular, we concentrate especially on a smoothing effect caused by the distribution of the cell population in time and introduce several methods for inverting this phenomenon. The proposed methods can be used to significantly improve the accuracy of the gene expression time-series measurements since the cell population asynchrony (wide distribution) is inevitably caused by the different operation pace of the cells. Some of the proposed methods rely on the partition of the genes, as well as the corresponding expression profiles, into the cell cycle regulated and noncell cycle regulated genes. For that purpose, we first study the cell cycle regulated genes and introduce a method that can be used to estimate the period length of those genes. We also estimate the spreading rate of the underlying distribution of the cell population based solely on the observed gene expression data. After the preliminary experiments, we introduce some methods for estimating the underlying distribution of the cell population instead of its spreading rate. These methods assume certain additional measurements, such as flow cytometry (e.g. fluorescent-activated cell sorter (FACS)) or bud counting measurements, to be available. We also apply the standard blind deconvolution method for estimating the true distribution of the cell population. The found estimates of the spreading rate of the cell distribution and the distributions of the cell population themself are used to invert the smoothing effect. To that end, we discuss some inversion approaches applicable to the problem in hand.
ClearPen: improving the legibility of handwriting
Authors: Timothy S. Butler
Venue: CHI '03 extended abstracts on Human factors in computing systems (2003)

We describe the application of a pen model, and sub-pixel addressing (ClearPen), to render handwriting on an LCD display. This technique is shown to improve the legibility of handwriting. ClearPen can increase the viability of working with handwriting on a computer. This has direct significance to TabletPC applications such as note taking or annotating documents.
Knowledge Networks: Explaining Effective Knowledge Sharing in Multiunit Companies
Authors: Morten T. Hansen
Venue: Organization Science (2002)

This paper introduces the concept of knowledge networks to explain why some business units are able to benefit from knowledge residing in other parts of the company while others are not. The core premise of this concept is that a proper understanding of effective interunit knowledge sharing in a multiunit firm requires a joint consideration of relatedness in knowledge content among business units and the network of lateral interunit relations that enables task units to access related knowledge. Results from a study of 120 new product development projects in 41 business units of a large multiunit electronics company showed that project teams obtained more existing knowledge from other units and completed their projects faster to the extent that they had short interunit network paths to units that possessed related knowledge. In contrast, neither network connections nor extent of related knowledge alone explained the amount of knowledge obtained and project completion time. The results also showed a contingent effect of having direct interunit relations in knowledge networks: While established direct relations mitigated problems of transferring noncodified knowledge, they were harmful when the knowledge to be transferred was codified, because they were less needed but still involved maintenance costs. These findings suggest that research on knowledge transfers and synergies in multiunit firms should pursue new perspectives that combine the concepts of network connections and relatedness in knowledge content.
Pinwheel Scheduling for Fault-Tolerant Broadcast Disks in Real-time Database Systems
Authors: Sanjoy K. Baruah, Azer Bestavros
Venue: Proceedings of the Thirteenth International Conference on Data Engineering (1997)

The design of programs for broadcast disks which incorporate real-time and fault-tolerance requirements is considered. A generalized model for real-time fault-tolerant broadcast disks is defined. It is shown that designing programs for broadcast disks specified in this model is closely related to the scheduling of pinwheel task systems. Some new results in pinwheel scheduling theory are derived, which facilitate the efficient generation of real-time fault-tolerant broadcast disk programs.
On optimization of a car rim using finite element method
Authors: H. Akbulut
Venue: Finite Elements in Analysis and Design (2003)

This paper presents the optimization of an octopus-type car rim for which critical zones were found first and then optimum thickness was investigated using an elasto-plastic analysis. In this study, three-dimensional finite element method was used for conducting elasto-plastic analysis. In the finite elements analysis, the elements forming the meshes are hexahedral linear elements with eight nodes. Twelve different meshes were used. A quadrant of the rim was utilized due to its symmetric shape. The theoretical results were compared with experimental ones. It seems that the theoretical results are in agreement with the experimental ones. The results are presented in tabular and graphical forms.
Introduction to Stochastic Search and Optimization, 1 edition
Authors: James C. Spall
Venue:  (2003)

:* Unique in its survey of the range of topics. * Contains a strong, interdisciplinary format that will appeal to both students and researchers. * Features exercises and web links to software and data sets.
On the parametric complexity of schedules to minimize tardy tasks
Authors: Michael R. Fellows, Catherine McCartin
Venue: Theoretical Computer Science (2003)

Given a set T of tasks, each of unit length and having an individual deadline d(t) ∈ Z+, a set of precedence constraints on T, and a positive integer k ≤ |T|, we can ask "Is there a one-processor schedule for T that obeys the precedence constraints and contains no more than k late tasks?" This is a well-known NP-complete problem.We might also inquire "Is there a one-processor schedule for T that obeys the precedence constraints and contains at least k tasks that are on time i.e. no more than |T| - k late tasks?"Within the framework of classical complexity theory, these two questions are merely different instances of the same problem. Within the recently developed framework of parameterized complexity theory, however, they give rise to two separate problems that may be studied independently of one another.We investigate these problems from the parameterized point of view. We show that, in the general case, both these problems are hard for the parameterized complexity class W[1].In contrast, in the case where the set of precedence constraints can be modelled by a partial order of bounded width, we show that both these problems are fixed parameter tractable.
Exact multiplicity for degenerate two-point boundary value problems with p-convex nonlinearity
Authors: J. Karátson, P. L. Simon
Venue: Nonlinear Analysis: Theory, Methods Applications (2003)

The exact number of positive solutions of a degenerate quasilinear two-point boundary value problem is investigated. For the generalization of earlier results concerning the nondegenerate case with convex nonlinearity, suitably defined p-convex nonlinearities are considered. Strictly p-convex C2 functions having a non-negative root are classified according to the shape of the bifurcation diagram of positive solutions versus the length of the interval. We have uniqueness when f(0) ≤ 0 and 0, 1 or 2 solutions when f(0) > 0 (similarly to the non-degenerate case), provided that the number of solutions is finite. However, now there may also occur a continuum of solutions, connected to a dead core type phenomenon. The proof of our results relies on the shooting method for the characterization of the shape of the time-map. In contrast to the non-degenerate case, the shooting method does not determine directly the number of solutions, owing to the lack of uniqueness of the corresponding IVP. Exact conditions on the uniqueness of the IVP and, in the case of non-uniqueness, the number and types of its local solutions are given. Based on this, all the positive solutions of the BVP can be compiled.
A New Markov Model For Web Access Prediction
Authors: Xing Dongshan, Shen Junyi
Venue: Computing in Science and Engineering (2002)

Web access prediction is an important research direction in Web mining. Markov models are well-suited for predicting Web access. Although higher-order Markov models have good predictions result, these models have several limitations associated with high state-space complexity and reduced coverage. These affect the prediction performance deeply. A new Web access prediction model, Hybrid-order Tree-like Markov Model (HTMM), is proposed in this article. The technique intelligently merges two methods: a tree-like Markov model method that aggregates the access sequences by pattern matching and a hybrid-order method that combines varying order Markov models so that the resulting model has a low state complexity, improved prediction accuracy, and retains high coverage. Experiments confirm its usefulness. It's suitable for applications in E-business, such as Web prefetching, link prediction, and recommendation.
Predicate Matching and Subscription Matching in Publish/Subscribe Systems
Authors: Ghazaleh Ashayer, Hubert Ka Yau Leung, H.-Arno Jacobsen
Venue: Proceedings of the 22nd International Conference on Distributed Computing Systems (2002)

An important class of publish/subscribe matching algorithms work in two stages. First, predicates are matched and then matching subscriptions are derived. We observe that in practice, the domain types over which predicates are defined are often of fixed enumerable cardinality. Based on this observation we propose a table-based look-up scheme for fast predicate evaluation that finds all matching predicates for each type with one table lookup. We compare this scheme to alternative general-purpose implementations. This observation may also suggests that matching in publish/subscribe systems could equally well be implemented with standard database technology. We propose two DBMS-based matchingalgorithms and compare the better one with a special purpose publish/subscribe matching algorithm implementation. We provide first evidence that for application scenarios that require large subscription workloads and process many events a DBMS-based solution is not a feasible alternative.
Two-Version Based Concurrency Control and Recovery in Real-Time Client/Server Databases
Authors: Tei-Wei Kuo, Yuan-Ting Kao, Chin-Fu Kuo
Venue: IEEE Transactions on Computers (2003)

While there has been a significant amount of research in real-time concurrency control, little work has been done in logging and recovery for real-time databases. This paper proposes a two-version approach which considers both real-time concurrency control and recovery. We propose a network-server-based architecture and algorithms which can not only reduce the blocking time of higher-priority transactions and improve the response time of client-side read-only transactions, but also provide a diskless runtime logging mechanism and an efficient and predictable recovery procedure. The performance of the algorithms was verified by a series of simulation experiments by comparing the algorithms with the well-known Priority Ceiling Protocol (PCP), the Read/Write PCP, the New PCP, and the 2-version two-phase locking protocol, for which we have very encouraging results. The schedulability of higher-priority transactions and the response time of client-side read-only transactions were all greatly improved.
Choosing k for two-class nearest neighbour classifiers with unbalanced classes
Authors: David J. Hand, Veronica Vinciotti
Venue: Pattern Recognition Letters (2003)

Supervised classification problems in which the class sizes are very different are common. In such cases, nearest neighbour classifiers exhibit a non-monotonic relationship between the number of nearest neighbours and misclassification rate of each of the two classes separately.
An architecture to support scalable online personalization on the Web
Authors: Anindya Datta, Kaushik Dutta, Debra VanderMeer, Krithi Ramamritham, Shamkant B. Navathe
Venue: The VLDB Journal &mdash; The International Journal on Very Large Data Bases (2001)

Online personalization is of great interest to e-companies. Virtually all personalization technologies are based on the idea of storing as much historical customer session data as possible, and then querying the data store as customers navigate through a web site. The holy grail of online personalization is an environment where fine-grained, detailed historical session data can be queried based on current online navigation patterns for use in formulating real-time responses. Unfortunately, as more consumers become e-shoppers, the user load and the amount of historical data continue to increase, causing scalability-related problems for almost all current personalization technologies. This paper chronicles the development of a real-time interaction management system through the integration of historical data and online visitation patterns of e-commerce site visitors. It describes the scientific underpinnings of the system as well as its architecture. Experimental evaluation of the system shows that the caching and storage techniques built into the system deliver performance that is orders of magnitude better than those derived from off-the-shelf database components.
Improved Empty Freight Car Distribution
Authors: Kaj Holmberg, Martin Joborn, Jan T. Lundgren
Venue: Transportation Science (1998)

In this paper we consider the problem of distributing empty freight cars in a railway company. We describe and analyze the current planning process, identify the shortcomings of the process, and stress the importance of a reliable distribution process for satisfying customer demand and reducing capital costs. We show how the process can be improved using an optimization model which includes capacity constraints on the trains and adheres explicitly to the arrival and departure times of the trains. The optimization model can be characterized as a multicommodity network flow model with integer requirements. Computational tests show that the model can be solved in acceptable time for real size problems, and indicate that the model generates distribution plans that can improve the quality of the planning process.
Scheduling with Fixed Delivery Dates
Authors: Nicholas G. Hall, Maseka Lesaoana, Chris N. Potts
Venue: Operations Research (2001)

In most classical scheduling models, it is assumed that a job is dispatched to a customer immediately after its processing completes. In many practical situations, however, a set of delivery dates may be fixed before any jobs are processed. This is particularly relevant where delivery is an expensive or complicated operation, for example, as with heavy machinery. A similar situation arises where customers find deliveries disruptive and thus require them to be made within a limited time interval that repeats periodically. A third possibility is that a periodic business function, for example, the supplier's billing cycle, effectively defines a delivery date, and includes all jobs that have been completed since the previous billing cycle. These situations are not adequately represented by classical scheduling models. We consider a variety of deterministic scheduling problems in which a job is dispatched to a customer at the earliest fixed delivery date that is no earlier than the completion time of its processing. Problems where the number of delivery dates is constant, and others where it is specified as part of data input, are studied. For almost all problems considered, we either provide an efficient algorithm or establish that such an algorithm is unlikely to exist. By doing so, we permit comparisons between the solvability of these fixed delivery date problems and of the corresponding classical scheduling problems.
On the M/M/1 Queue with Catastrophes and Its Continuous Approximation
Authors: A. Di Crescenzo, V. Giorno, A. G. Nobile, L. M. Ricciardi
Venue: Queueing Systems: Theory and Applications (2003)

For the M/M/1 queue in the presence of catastrophes the transition probabilities, densities of the busy period and of the catastrophe waiting time are determined. A heavy-traffic approximation to this discrete model is then derived. This is seen to be equivalent to a Wiener process subject to randomly occurring jumps for which some analytical results are obtained. The goodness of the approximation is discussed by comparing the closed-form solutions obtained for the continuous process with those obtained for the M/M/1 catastrophized queue.
Software Development In Java
Authors: Sartaj Sahni, Raj Kumar
Venue:  (2003)

: Synopsis Software Development in Java is a comprehensive introduction to all aspects of software development such as specification, modularization, stepwise refinement, testing, verification. The authors also discuss performance analysis and measurement methods and how to make choices between data structures and algorithms. The authors use Java to teach software development and for the examples. Software Development in Java is appropriate for use as a textbook for courses on good software development, and advanced programming. Software Development in Java is a must for software developers. About the Author RAJ KUMAR is a consultant with 10 years of experience in designing building software systems. He is an expert in databases and web technologies. DR. SARTAJ SAHNI is a Distinguished Professor and Chair of Computer Information Sciences and Engineering at the University of Florida. He got his PhD in Computer Science from Cornell University. Dr. Sahni is the author or coauthor of 14 text books and over 250 research papers in computer science.