ppxscal/embedding_network huggingface dataset:
A survey of messaging software issues and systems for Myrinet-based clusters
Authors: Rodrigo Weber dos Santos, Ricardo Bianchini, Claudio L. Amorim
Venue: Cluster Computing (2001)

Several messaging software architectures (MSAs) have been proposed that entirely remove the operating system from the critical communication path, providing direct user-level access to the network interface and avoiding excessive data copying. In this paper we discuss the most important design issues and tradeoffs related to the functionality and performance of MSAs: the communication model, DMA versus programmed I/O transfers, data copying and protection, message pipelining, message arrival notification, and reliability. In order to illustrate how these issues and tradeoffs are tackled in modern systems, we survey a large number of recently proposed MSAs for the Myrinet interconnection network, including AM, FM, U-Net, VMMC, BIP, PM, and Trapeze.
System administrators are users, too: designing workspaces for managing internet-scale systems
Authors: Rob Barrett, Yen-Yang Michael Chen, Paul P. Maglio
Venue: CHI '03 extended abstracts on Human factors in computing systems (2003)

The people who run large-scale computer systems deserve the attention of the HCI community. These professionals work with increasingly diverse and complex hardware and software, large systems often characterized as "unknowable" by a single person. Relying on relatively crude tools, these professionals keep the technological world running. By improving the system administration work environment, the cost of computing and risk of downtime will be decreased while the deployment of complex, beneficial systems will increase.This one-day workshop will focus on the HCI problems of system administrators, specifically management of scale and diversity, problem solving, and system monitoring and notification. Our goal is to bring together (1) HCI researchers, (2) middleware user interface software developers, and (3) real-world system administrators to form a cross-disciplinary community around this topic.
Assessing the Benefits of Different Stock-Allocation Policies for a Make-to-Stock Production System
Authors: Francis de Véricourt, Fikri Karaesmen, Yves Dallery
Venue: Manufacturing Service Operations Management (2001)

We consider a manufacturing facility that produces a single item that is demanded by several different classes of customers. The inventory-related cost performance of such a system can be improved by effective allocation of production and inventories. We obtain the optimal parameters for three easily implementable allocation policies. Our results cover the case of linear backorder costs as well as fill-rate constraints. We compare the optimal performance of these control policies to gain insights into the benefits of different production and stock-allocation rules.
Semismooth Matrix-Valued Functions
Authors: Defeng Sun, Jie Sun
Venue: Mathematics of Operations Research (2002)

Matrix-valued functions play an important role in the development of algorithms for semidefinite programming problems. This paper studies generalized differential properties of such functions related to nonsmooth-smoothing Newton methods. The first part of this paper discusses basic properties such as the generalized derivative, Rademacher's theorem, B-derivative, directional derivative, and semismoothness. The second part shows that the matrix absolute-value function, the matrix semidefinite-projection function, and the matrix projective residual function are strongly semismooth.
A Subassembly Manufacturing Yield Problem with Multiple Production Runs
Authors: Purushottaman Nandakumar, Jeffrey L. Rummel
Venue: Operations Research (1998)

We consider the assembly of a product that needs to exceed a certain length. The subassemblies are manufactured with a planned length setting. The resulting lengths of the subassemblies are not known with certainty, and vary about the planned setting. After the subassemblies are manufactured, those that fall short are rerun. This process is repeated until all subassemblies exceed the required length. We build and solve a model, to specify the planned length at each run, that minimizes the expected cost of production.
When Does a Dynamic Programming Formulation Guarantee the Existence of a Fully Polynomial Time Approximation Scheme (FPTAS)?
Authors: Gerhard J. Woeginger
Venue: INFORMS Journal on Computing (2000)

We derive results of the following flavor: If a combinatorial optimization problem can be formulated via a dynamic program of a certain structure and if the involved cost and transition functions satisfy certain arithmetical and structural conditions, then the optimization problem automatically possesses a fully polynomial time approximation scheme (FPTAS). Our characterizations provide a natural and uniform approach to fully polynomial time approximation schemes. We illustrate their strength and generality by deducing from them the existence of FPTASs for a multitude of scheduling problems. Many known approximability results follow as corollaries from our main result.
A Min-Max Theorem on Feedback Vertex Sets
Authors: Mao-Cheng Cai, Xiaotie Deng, Wenan Zang
Venue: Mathematics of Operations Research (2002)

We establish a necessary and sufficient condition for the linear system { x :Hx =e,x = 0} associated with a bipartite tournament to be totally dual integral, whereH is the cycle-vertex incidence matrix ande is the all-one vector. The consequence is a min-max relation on packing and covering cycles, together with strongly polynomial time algorithms for the feedback vertex set problem and the cycle packing problem on the corresponding bipartite tournaments. In addition, we show that the feedback vertex set problem on general bipartite tournaments isNP-complete and approximable within 3.5 based on the min-max theorem.
Capital Budgeting Under Uncertainty--An Integrated Approach Using Contingent Claims Analysis and Integer Programming
Authors: Helga Meier, Nicos Christofides, Gerry Salkin
Venue: Operations Research (2001)

Recently the application of contingent claims analysis and dynamic programming to project evaluation has attracted a lot of attention. These techniques are required, for example, if the value of a project develops stochastically over time and the decision to invest into this project can be postponed. Yet, so far there are no considerations regarding how this perception of projects reflects on a capital budgeting situation. We propose two approaches that integrate these methods with traditional capital budgeting models. A simple capital budgeting model can be formulated as the problem of finding the portfolio of options that has maximal value and fulfils the capital expenditure constraint. However, this model has some shortcomings regarding its applicability in traditional budgeting situations. Therefore, we define an alternative optimisation model that uses scenarios to depict a set of possible future states. The optimal portfolio is then equivalent to a dynamic investment strategy that determines a number of state-dependent optimal portfolios.
Self-organised dynamic recognition states for chaotic neural networks
Authors: Nigel Crook, Tjeerd olde Scheper, Vasantha Pathirana
Venue: Information Sciences&mdash;Informatics and Computer Science: An International Journal (2003)

Chaos offers several advantages to the Engineer over other non-chaotic dynamics. One is that chaotic systems are often significantly easier to control than other linear or non-linear systems, requiring only small, appropriately timed perturbations to constrain them within specific unstable periodic orbits (UPOs). Another is that chaotic attractors contain an infinite number of these UPOs. If individual UPOs can be made to represent specific internal states of a system, then a chaotic attractor can be turned into an infinite state machine. In this paper we investigate this possibility with respect to chaotic neural networks. We present a method by which a network can self-select UPOs in response to specific input values. These UPOs correspond to network recognition states for these input values.
Structural Properties of Stochastic Dynamic Programs
Authors: James E. Smith, Kevin F. McCardle
Venue: Operations Research (2002)

In Markov models of sequential decision processes, one is often interested in showing that the value function is monotonic, convex, and/or supermodular in the state variables. These kinds of results can be used to develop a qualitative understanding of the model and characterize how the results will change with changes in model parameters. In this paper we present several fundamental results for establishing these kinds of properties. The results are, in essence, "metatheorems" showing that the value functions satisfy propertyP if the reward functions satisfy propertyP and the transition probabilities satisfy a stochastic version of this property. We focus our attention on closed convex cone properties, a large class of properties that includes monotonicity, convexity, and supermodularity, as well as combinations of these and many other properties of interest.
Internet path characterization tools
Authors: Dulal C. Kar
Venue: Journal of Computing Sciences in Colleges (2002)

Recently, new tools for Internet path characterization have been released. The tools allow finding the bandwidth, packet loss rate, average queuing delay, and latency of every hop along the path from a sender to a destination host. This has created many teaching and research opportunities in the area of computer networking. Based on these tools, many interesting assignments and projects for computer networking courses can be developed. Some of the tool developers have made their source code publicly available. As such, researchers can extend or tailor such tools to fit their needs. In this work, we provide an overview of the underlying algorithm of these tools, a usage of the tools in finding bandwidths of Internet hops and an outline for some other uses of the tools for teaching purposes.
Coloring edges of graphs embedded in a surface of characteristic zero
Authors: Daniel P. Sanders, Yue Zhao
Venue: Journal of Combinatorial Theory Series B (2003)

Consider graphs that are embeddable in a surface of characteristic zero. Class two graphs of this type with maximum degree Δ ≤ 6 are known to exist. Hind and Zhao showed that such graphs with maximum degree Δ ge; 8 must be class one. This article shows that such graphs with maximum degree Δ = 7 also must be class one, completing the analysis of these surfaces. These are the first surfaces where the maximum degree of class two graphs has been determined.
Minimax-or feared value-L1/L&#x221E; control
Authors: Pierre Bernhard
Venue: Theoretical Computer Science (2003)

This is the third paper, after Bernhard (Expected value, feared value and partial information optimal control, in G.J. Olsder (Ed.), New Trends in Dynamic Games and Applications, Annals of the International Society of Dynamic Games, vol. 3, Birkhauser, Boston, USA, 1995, pp. 95-100; A Separation Theorem for Expected Value and Feared Value Discrete Time Control, COCV, Vol. 1, pp. 191-206, SMAI, www.emath.fr/cocv, 1996.), where we attempt to develop and exploit the parallel between stochastic control and rain-max control induced by the use of the max-plus algebra, using the concept of feared value as the parallel to expected value. The present paper builds on the main formula of Bernhard (1996), the results of which are a subset of those given here. Its new contribution is twofold. On the one hand we clarify the role of the integral part of the cost in that parallel. This leads to a more extensive theory of the so-called (imperfect information) minimax L∞ control problem than apparently available in the literature including a certainty equivalence theorem. On the other hand, we extend the parallel to the continuous time case as much as we can. In that direction, the present paper slightly extends the classical framework of the variational inequality of stopping time games, and gives a formal treatment of the partial information case. Altogether, this might be the first new results obtained with the tool of mathematical fear.
Utilizing mobile devices to capture case stories for knowledge management
Authors: Jia Shen
Venue: CHI '03 extended abstracts on Human factors in computing systems (2003)

This study examines how the increasing number of new mobile devices that enable rich in situ information capture can be utilized to improve knowledge management practices. An ethnographic study is being conducted of a heating and cooling services company focusing on the exchange of case stories. With knowledge gained from this study a prototype system is being built that allows in situ multi-media data capture, and retrieval via the Internet. The proposed field study of this system will extend our understanding of how to effectively design for in situ multi-media data capture so that it is integrated in organizational processes.
A posteriori error estimates applied to flow in a channel with corners
Authors: Pavel Burda, Jaroslav Novotný, Bedřich Sousedík
Venue: Mathematics and Computers in Simulation (2003)

The paper consists of three parts. In the first part, we investigate a posteriori error estimates for the Stokes and Navier-Stokes equations on two-dimensional polygonal domains. Special attention is paid to the sources of the constants in the estimates, as these play a crucial role in practical applications to adaptive refinements, as we also show. In the second part, we deal with the problem of determining accurately the constants that appear in the estimates. We present a technique for calculating the constant with high accuracy. In the third part, we apply the a posteriori error estimates with the constants found numerically to the technique of adaptive mesh refinement-we solve an incompressible flow problem in a domain with corners that cause singularities in the solution.
DG: a scalable approach for broadcasting data securely in wireless networks
Authors: Aslihan Celik, Anindya Datta
Venue: Wireless Networks (2003)

This paper addresses the problem of providing secure access control in broadcast schemes in a wireless network. We consider an environment where clients subscribe to information objects sent via a broadcast onto a wireless network. In this context, a client should only be able to access its objects of interest for its subscription period, and the security system used must not be easily broken. Existing data broadcasting approaches fail to perform well with increased client loads. In this paper, we propose to use the Drop Groups (DG) protocol, that uses a novel grouping criterion. We present the broadcast organization under DG, and demonstrate that our approach is scalable. We use simulation to compare the DG protocol with existing techniques.
Reconstruction of Wavelet Coefficients Using Total Variation Minimization
Authors: Sylvain Durand, Jacques Froment
Venue: SIAM Journal on Scientific Computing (2002)

We propose a model to reconstruct wavelet coefficients using a total variation minimization algorithm. The approach is motivated by wavelet signal denoising methods, where thresholding small wavelet coefficients leads to pseudo-Gibbs artifacts. By replacing these thresholded coefficients by values minimizing the total variation, our method performs a nearly artifact-free signal denoising. In this paper, we detail the algorithm based on a subgradient descent combining a projection on a linear space. The convergence of the algorithm is established and numerical experiments are reported.
Worker Cross-Training in Paced Assembly Lines
Authors: George Vairaktarakis, Janice Kim Winch
Venue: Manufacturing Service Operations Management (1999)

Paced or Synchronous assembly lines are a popular class of assembly systems consisting of a series of assembly stations arranged in tandem. Every job (or order) visits all assembly stations in the same sequence and spends the same amount of time (known as the production cycle) at each station. Industries such as aircraft, fire-engine, and automobile assembly have production cycles of a few hours and are labor intensive. In spite of increased automation in such industries, human capital remains the most expensive and important contributor to a flexible production system. In this article we formulate the cross-training problem on a paced assembly line with m stations (mCT). We assume that each worker possesses a number of skills referred to as a skill vector. Our objective is to schedule a set of work orders through the assembly system so as to minimize the size of the required workforce and/or the workforce cross-training costs. We analyze the complexity of mCT and identify polynomially solvable cases. A variety of lower bounds is developed based on optimization techniques. These lower bounds are used to develop a branch and bound algorithm as well as to evaluate our heuristics. A computational experiment reports the performance of all algorithms. Using these algorithms, we examine how the formation of skill vectors affects the workforce size and draw guidelines for cross-training programs in organizations with labor intensive assembly operations.
Industrial applications of model checking
Authors: Alessandro Cimatti
Venue: Modeling and verification of parallel processes (2001)

Formal methods have a great potential of application in the development of industrial critical systems. In certain application fields, formal methods are even becoming part of standards. Among formal methods, Model Checking is proving particularly effective, especially thanks to its ability to automatically analyze complex designs and to produce counterexamples. However, the application of formal methods in the industrial development practice is by no means trivial. Formal methods can be costly, slow down the development, and require training and changes to the development cycle. In this paper, the application of Model Checking techniques in the development of industrial critical systems is discussed, by focusing on two projects where Model Checking has been successfully applied under different conditions.
Graph visualization for the analysis of the structure and dynamics of extreme-scale supercomputers
Authors: Cheng Zhou, Kenneth L. Summers, Thomas P. Caudell
Venue: Proceedings of the 2003 ACM symposium on Software visualization (2003)

We are exploring the development and application of information visualization techniques for the analysis of new massively parallel supercomputer architectures. Modern supercomputers typically comprise very large clusters of commodity SMPs interconnected by possibly dense and often nonstandard networks. The scale, complexity, and inherent nonlocality of the structure and dynamics of this hardware, and the systems and applications distributed over it, challenge traditional analysis methods. As part of the 'a la carte team at Los Alamos National Laboratory, who are simulating these advanced architectures, we are exploring advanced visualization techniques and creating tools to provide intuitive exploration, discovery, and analysis of these simulations. This work complements existing and emerging algorithmic analysis tools. This paper gives background on the problem domain, a description of a prototypical computer architecture of interest (on the order of 10,000 processors connected by a quaternary fat-tree communications network), and a presentation of two classes of visualizations that clearly display the switch structure and the flow of information in the interconnecting network.
Scenarios in practice
Authors: John Carroll, Mary Beth Rosson, Paul McInerney
Venue: CHI '03 extended abstracts on Human factors in computing systems (2003)

This one-day workshop focuses on how scenarios are being used in industrial projects effectively and efficiently. The scope includes the overlapping concerns of: (1) deployment (2) method integration (3) craft and quality, and (4) tailing to various project contexts.
A strongly polynomial-time algorithm for over-constraint resolution: efficient debugging of timing constraint violations
Authors: Ali Dasdan
Venue: Proceedings of the tenth international symposium on Hardware/software codesign (2002)

A system of binary linear constraints or difference constraints (SDC) contains a set of variables that are constrained by a set of unary or binary linear inequalities. In such diverse applications as scheduling, interface timing verification, real-time systems, multimedia systems, layout compaction, and constraint satisfaction, SDCs have successfully been used to model systems of both temporal and spatial constraints. Formally, SDCs are modeled by weighted, directed (constraint) graphs. The consistency of an SDC means that there is at least one instantiation of its variables that satisfies all its constraints. It is well known that the absence of positive cycles in a graph implies the consistency of the corresponding SDC, so the consistency can be decided in strongly polynomial time. If a SDC is found to be inconsistent, it has to be repaired to make it consistent. This task is equivalent to removing positive cycles from the corresponding graph. All the previous algorithms for this task take time proportional to the number of positive cycles in the graph, which can grow exponentially. In this paper, we propose a strongly polynomial-time algorithm, i.e., an algorithm whose time complexity is polynomial in the size of the graph. Our algorithm takes in a graph and returns a list of edges and the changes in their weights to remove all the positive cycles from the graph. We experimentally quantify the length of the edge list and the running time of the algorithm on large benchmark graphs. We show that both are very small, so our algorithm is practical.
Hamiltonian systems with orbits covering densely submanifolds of small codimension
Authors: Ernest Fontich, Pau Martín
Venue: Nonlinear Analysis: Theory, Methods Applications (2003)

The existence of a transition chain in a Hamiltonian system leads to the existence of orbits shadowing it, if some lambda lemma can be applied. This fact has been used to prove the existence of diffusion in perturbations of integrable a priori stable systems. We prove that, under suitable conditions, there are orbits which cover densely codimension two submanifolds of the (2n - 1)-dimensional energy level. We also construct examples, near general integrable systems, where the computations to verify the sufficient conditions for the appearance of such phenomenon can be performed.
A new approach to sum-fuzzy rational choice functions
Authors: Xiao Luo
Venue: Fuzzy Sets and Systems (2002)

The purpose of this paper is to present a new approach to sum-fuzzy rational choice functions. By making use of the model of perceptrons in neural theory, we establish a sufficient and necessary condition for sum-fuzzy rationality. Moreover, we provide a geometric characterization of sum-fuzzy rationality for single-valued choice functions. Based on the learning rules of perceptrons, we offer an algorithm to find a sum-fuzzy implementation of a choice function and, then, provide a concrete example.