ppxscal/embedding_network huggingface dataset:
A combinatorial algorithm for MAX CSP
Authors: Mayur Datar, Tomás Feder, Aristides Gionis, Rajeev Motwani, Rina Panigrahy
Venue: Information Processing Letters (2003)

We consider the problem MAX CSP over multi-valued domains with variables ranging over sets of size si ≤ s and constraints involving kj ≤ k variables. We study two algorithms with approximation ratios A and B. respectively, so we obtain a solution with approximation ratio max (A, B).The first algorithm is based on the linear programming algorithm of Serna, Trevisan, and Xhafa [Proc. 15th Annual Symp. on Theoret. Aspects of Comput. Sci., 1998, pp. 488-498] and gives ratio A which is bounded below by s1-k. For k = 2, our bound in terms of the individual set sizes is the minimum over all constraints involving two variables of (1/2√s1+ 1/2√s2)2, where s1 and s2 are the set sizes for the two variables.We then give a simple combinatorial algorithm which has approximation ratio B, with B > A/e. The bound is greater than s1-k/e in general, and greater than s1-k(1 - (s - 1)/2(k - 1)) for s ≤ k - 1, thus close to the s1-k linear programming bound for large k. For k = 2, the bound is 4/9 if s = 2, 1/2(s - 1) if s ≥ 3, and in general greater than the minimum of 1/4S1 + 1/4s2 over constraints with set sizes s1 and s2, thus within a factor of two of the linear programming bound.For the case of k = 2 and s = 2 we prove an integrality gap of 4/9 (1 + O(n-1/2)). This shows that our analysis is tight for any method that uses the linear programming upper bound.
Inventory productivity impacts of IT-enabled supply chain coordination in manufacturing environments
Authors: Kristina Setzekorn, Arun Rai, Arlyn J. Melcher
Venue: Creating business value with information technology: challenges and solutions (2003)

This chapter describes an empirical analysis of the mediating effects of supply chain coordination strategy and manufacturing IT infrastructure on the relationship between business complexity and inventory turnover. Business complexity describes the diversity and volatility associated with a firm's product markets. To cope with this complexity, firms deploy inventory buffers. This deployment should decrease inventory turnover. An extensive manufacturing IT infrastructure can increase a firm's "sense and respond" capability, reducing the need for buffers, and can thereby improve inventory turnover. As this technology enables enhanced coordination, and as firms' efforts to reduce buffers within their own organizational boundaries earn diminishing marginal returns, firms attempt to optimize performance across organizational boundaries within the supply chain, i.e., adopt a cooperative supply chain coordination strategy. This supply chain coordination should improve inventory turnover.
An "orderwise" polynomial regression procedure for fuzzy data
Authors: Pierpaolo D'Urso, Tommaso Gastaldi
Venue: Fuzzy Sets and Systems (2002)

A procedure for polynomial fit with fuzzy data is presented. As in real case studies, there is often dependence between modes and spreads, we propose a regression polynomial model capable to take into account possible interactions between the estimated spreads and modes. This method finds applications in several fields such as reliability, quality control, psychometrics, marketing, image processing, etc. An application to a software reliability problem is also presented.
Dynamic Scheduling for a Flexible Processing Network
Authors: Ick-Hyun Nam
Venue: Operations Research (2001)

We study flexible processing systems where there are multiple paths for a certain type of customer to follow through the system. This paper analyzes an open processing network model with discretionary routing. The underlying methodology is the heavy traffic approximation, which has been well publicized by many researchers. Allowing priority sequencing in addition to dynamic routing as our control policy, we show that the balanced workload routing rule does not necessarily give us an optimal solution. In general unbalanced workload routing with priority sequencing is shown to give us better performance than a balanced one. Through some simulation results we compare our recommendation with other scheduling policies for a flexible processing network.
Orion: a power-performance simulator for interconnection networks
Authors: Hang-Sheng Wang, Xinping Zhu, Li-Shiuan Peh, Sharad Malik
Venue: Proceedings of the 35th annual ACM/IEEE international symposium on Microarchitecture (2002)

With the prevalence of server blades and systems-on-a-chip (SoCs), interconnection networks are becoming an important part of the microprocessor landscape. However, there is limited tool support available for their design. While performance simulators have been built that enable performance estimation while varying network parameters, these cover only one metric of interest in modern designs. System power consumption is increasingly becoming equally, if not more important than performance. It is now critical to get detailed power-performance tradeoff information early in the microarchitectural design cycle. This is especially so as interconnection networks consume a significant fraction of total system power. It is exactly this gap that the work presented in this paper aims to fill.We present Orion, a power-performance interconnection network simulator that is capable of providing detailed power characteristics, in addition to performance characteristics, to enable rapid power-performance trade-offs at the architectural-level. This capability is provided within a general framework that builds a simulator starting from a microarchitectural specification of the interconnection network. A key component of this construction is the architectural-level parameterized power models that we have derived as part of this effort. Using component power models and a synthesized efficient power (and performance) simulator, a microarchitect can rapidly explore the design space. As case studies, we demonstrate the use of Orion in determining optimal system parameters, in examining the effect of diverse traffic conditions, as well as evaluating new network microarchitectures. In each of the above, the ability to simultaneously monitor power and performance is key in determining suitable microarchitectures.
EIS data: findings from an evolutionary study
Authors: Jose L. Salmeron
Venue: Journal of Systems and Software (2002)

In such a competitive environment as the present one, it is no longer enough for managers to make the right choices, but they must also make and implement them as quickly as possible. For this reason, they need several tools to provide them with information. These tools are called executive information systems (EIS). However, an EIS is only as useful as the data it utilizes. Findings show that quantitative data is the most common type of information provided by the EIS. Operative databases in functional areas constitute the main source of internal data provided by EIS, closely followed by data warehouses. Soft data gives a great value to EIS completing usual data. Despite this fact, none of the EIS analyzed include soft data. The capability to provide access to reliable data from several sources (external and internal) is a major issue in EIS. The use of external data is increasing. The most outstanding sources are the services of financial institutions. Findings show that analyzed EIS are experiencing a transition from the first-generation EIS to second-generation EIS.
Conditions for the structural existence of an eigenvalue of a bipartite (min, max, +)-system
Authors: Jacob van der Woude, Subiono
Venue: Theoretical Computer Science (2003)

In this paper we consider bipartite (min, max, +)-systems. We present conditions for the structural existence of an eigenvalue and corresponding eigenvector for such systems, where both the eigenvalue and eigenvector are supposed to be finite. The conditions are stated in terms of the system matrices that describe a bipartite (min, max, +)-system. Structural in the previous means that not so much the numerical values of the finite entries in the system matrices are important, rather than their locations within these matrices. The conditions presented in this paper can be seen as an extension towards bipartite (min, max, +)-systems of known conditions for the structural existence of an eigenvalue of a (max, +)-system involving the (ir)reducibility of the associated system matrix. Although developed for bipartite (min, max, +)-systems, the conditions for the structural existence of an eigenvalue also can directly be applied to general (min, max, +)-systems when given in the so-called conjunctive or disjunctive normal form.
A Market-Based Approach to Optimal Resource Allocation in Integrated-Services Connection-Oriented Networks
Authors: Panagiotis Thomas, Demosthenis Teneketzis, Jeffrey K. Mackie-Mason
Venue: Operations Research (2002)

We present an approach to the admission control and resource allocation problem in connection-oriented networks that offer multiple services to users. users' preferences are summarized by means of their utility functions, and each user is allowed to request more than one type of service. Multiple types of resources are allocated at each link along the path of a connection. We assume that the relation between Quality of Service (QoS) and resource allocation is given, and we incorporate it as a constraint into a static optimization problem. The objective of the optimization problem is to determine the amount of and required resources for each type of service to maximize the sum of the users' utilities. We prove the existence of a solution of the optimization problem and describe a competitive market economy that implements the solution and satisfies the informational constraints imposed by the nature of the decentralized resource allocation problem. The economy consists of four different types of agents: resource providers, service providers, users, and an auctioneer that regulates the prices based on the observed aggregate excess demand. The goods that are sold are: (i) the resources at each link of the network, and (ii) services constructed from these resources and then delivered to users. We specify an iterative procedure that is used by the auctioneer to update the prices, and we show that it leads to an allocation that is arbitrarily close to a solution of the optimization problem in a finite number of iterations.
Network-Optimized Road Pricing: Part I: a Parable and a Model
Authors: Robert B. Dial
Venue: Operations Research (1999)

Part I of a two-part series, this paper recites a parable and formulates a stochastic optimization model that determines optimal link tolls on a road network whose users' value of time is a random variable. The parable, introducing the problem, demonst rates the importance of the variability of the value of time. The model, cast as a variational inequality, becomes a specialized form of a bicriterion user-quilibrium traffic assignment. Its solution is a set of efficient tolls for all links in the network. These tolls induce an equilibrium traffic flow that is at once system-optimal and user-optimal-for all trips, regardless of their value of time. Part II develops a solution algorithm, gives examples, and provides performance statistics.
Use of research-based guidelines in the development of websites
Authors: Sanjay Koyani, Susan Allison
Venue: CHI '03 extended abstracts on Human factors in computing systems (2003)

The Communication Technologies Branch at the National Cancer Institute has been working for the past two years to identify research related to web design and usability and to translate that research into web design guidelines. This effort has resulted in a set of approximately 200 guidelines that have strength of evidence and relative importance ratings. Panel members vary in their opinions on how and when to make the best use of guidelines in the development of websites. They will discuss issues related to translating research to guidelines, validation of guidelines, usability of guidelines themselves, and how to handle conflicting research.
Limiting periodicity of the solutions for some Volterra difference equations
Authors: V. B. Kolmanovskii
Venue: Nonlinear Analysis: Theory, Methods Applications (2003)

Conditions of the limiting of periodicity of the solutions for some Volterra difference equations are derived. These conditions are formulated immediately in terms of the coefficients of equations and their resolvent, using the second Liapunov method and fixed point theorem.
The Use of Rewards to Increase and Decrease Trust: Mediating Processes and Differential Effects
Authors: Donald L. Ferrin, Kurt T. Dirks
Venue: Organization Science (2003)

We test hypotheses asserting that reward structures--an omnipresent element of the work context--have a strong influence on interpersonal trust, and we explore the cognitive and behavioral routes through which the effects may occur. Specifically, we use attribution theory to identify several core processes including social perception (causal schemas), self-perception, and attributional biases (correspondence bias, suspicion effects, and preexisting expectations) that may explain trust development. A 3 (cooperative/competitive/mixed rewards) X 2 (high/low initial trust) experimental design in a problem-solving task was used to examine the hypotheses. The results suggest that reward structures have a strong influence on trust, and that the effect is mediated by causal schemas, suspicion effects, and self-perception. We also found some support for the prediction that the impact of mixed reward structures on trust is biased by individuals' preexisting expectations about their partner's trustworthiness. The theory and results suggest that attribution theory provides a useful framework for understanding the complex, diverse, and multiple routes through which trust may develop.
Weakly distance-regular digraphs
Authors: Kaishun Wang, Hiroshi Suzuki
Venue: Discrete Mathematics (2003)

We consider the following generalization of distance-regular digraphs. A connected digraph Γ is said to be weakly distance-regular if, for all vertices x and y with (δ(x,y),δ(y,x))= h, |{z ∈ VΓ| (δ(x,z),δ(z,x)) = i and (δ(z, y),δ(y,z)) = j}| depends only on h, i and j. We give some constructions of weakly distance-regular digraphs and discuss the connections to association schemes. Finally, we determine all commutative weakly distance-regular digraphs of valency 2.
Research Commentary: The Next Wave of Nomadic Computing
Authors: Kalle Lyytinen, Youngjin Yoo
Venue: Information Systems Research (2002)

A nomadic information environment is a heterogeneous assemblage of interconnected technological, and social, and organizational elements that enable the physical and social mobility of computing and communication services between organizational actors both within and across organizational borders. We analyze such environments based on their prevalent features of mobility, digital convergence, and mass scale, along with their mutual interdependencies. By using a framework that organizes research topics in nomadic information environments at the individual, team, organizational, and inter organizational levels and is comprised of both service and infrastructure development, we assess the opportunities and challenges for IS research. These deal with the design, use, adoption, and impacts of nomadic information environments. We conclude by discussing research challenges posed by nomadic information environments for information systems research skills and methods. These deal with the need to invent novel research methods and shift our research focus, the necessity to question the divide between the technical and the social, and the need to better integrate developmental and behavioral (empirical) research modes.
9-11 Information Failures: A Semiotic Approach
Authors: Kevin C. Desouza, Tobin Hensgen
Venue: IT Professional (2003)

Coupling information gathering systems with cohesive, associative applications might have left the US better prepared.
Simultaneous Assignment of Locomotives and Cars to Passenger Trains
Authors: Jean-François Cordeau, François Soumis, Jacques Desrosiers
Venue: Operations Research (2001)

The problem of assigning locomotives and cars to trains is a complex task for most railways. In this paper, we propose a multicommodity network flow-based model for assigning locomotives and cars to trains in the context of passenger transportation. The model has a convenient structure that facilitates the introduction of maintenance constraints, car switching penalties, and substitution possibilities. The large integer programming formulation is solved by a branch-and-bound method that relaxes some of the integrality constraints. At each node of the tree, a mixed-integer problem is solved by a Benders decomposition approach in which the LP relaxations of multicommodity network flow problems are optimized either by the simplex algorithm or by Dantzig-Wolfe decomposition. Some computational refinements, such as the generation of Pareto-optimal cuts, are proposed to improve the performance of the algorithm. Computational experiments performed on two sets of data from a railroad show that the approach can be used to produce optimal solutions to complex problems.
The Measurement of Web-Customer Satisfaction: An Expectation and Disconfirmation Approach
Authors: Vicki McKinney, Kanghyun Yoon, Fatemeh ?Mariam? Zahedi
Venue: Information Systems Research (2002)

Online shopping provides convenience to Web shoppers, yet its electronic format changes information-gathering methods traditionally used by customers. This change raises questions concerning customer satisfaction with the online purchasing process. Web shopping involves a number of phases, including the information phase, in which customers search for information regarding their intended purchases. The purpose of this paper is to develop theoretically justifiable constructs for measuring Web-customer satisfaction during the information phase.By synthesizing the expectation-disconfirmation paradigm with empirical theories in user satisfaction, we separate Web site quality into information quality (IQ) and system quality (SQ), and propose nine key constructs for Web-customer satisfaction. The measurements for these constructs are developed and tested in a two-phase study. In the first phase, the IQ and SQ dimensions are identified, and instruments for measuring them are developed and tested. In the second phase, using the salient dimensions of Web-IQ and Web-SQ as the basis for formulating first-order factors, we develop and empirically test instruments for measuring IQ and SQ-satisfaction. Moreover, this phase involves the design and test of second-order factors for measuring Web-customer expectations, disconfirmation, and perceived performance regarding IQ and SQ. The analysis of the measurement model indicates that the proposed metrics have a relatively high degree of validity and reliability. The results of the study provide reliable instruments for operationalizing the key constructs in the analysis of Web-customer satisfaction within the expectation-disconfirmation paradigm.
Fair Queuing and Other Probabilistic Allocation Methods
Authors: Hervé Moulin, Richard Stong
Venue: Mathematics of Operations Research (2002)

A server processes one job per unit of time and randomly schedules the jobs requested by a given set of users; each user may request a different number of jobs.Fair queuing (Shenker 1989) schedules jobs in successive round-robin fashion, where each agent receives one unit in each round until his demand is met and the ordering is random in each round. Fair queuing *, the reverse scheduling of fair queuing, serves first (with uniform probability) one of the users with the largest remaining demand.We characterize fair queuing * by the combination of lower composition--LC--(the scheduling sequence is history independent), demand monotonicity--DM--(increasing my demand cannot result in increased delay) and two equity axioms, equal treatment ex ante--ETEA (two identical demands give the same probability distribution of service) and equal treatment ex post--ETEP (two identical demands must be served in alternating fashion). The set of dual axioms (in which ETEA and ETEP are unchanged) characterizes fair queuing.We also characterize the rich family of methods satisfying LC, DM, and the familiar consistency--CSY--axiom. They work by fixing a standard of comparison (preordering) between a demand ofx iunits by agenti and one ofx junits by agentj. The first job scheduled is drawn from the agents whose demand has the highest standard.
An Evolutionary Approach to Group Decision Making
Authors: Jackie Rees, Gary J. Koehler
Venue: INFORMS Journal on Computing (2002)

We propose modeling Group Support System (GSS) search tasks with Genetic Algorithms. Using explicit mathematical models for Genetic Algorithms (GAs), we show how to estimate the underlying GA parameters from an observed GSS solution path. Once these parameters are estimated, they may be related to GSS variables such as group composition and membership, leadership presence, the specific GSS tools available, incentive structure, and organizational culture. The estimated Genetic Algorithm parameters can be used with the mathematical models for GAs to compute or simulate expected GSS process out comes.
A pattern-based J2EE application development environment
Authors: Imed Hammouda, Kai Koskimies
Venue: Nordic Journal of Computing (2002)

J2EE is Java's platform for building distributed enterprise applications. The platform takes advantage of a wide range of new and evolving technologies and has been enriched by proven design solutions. These solutions are formulated and documented in what is known as J2EE design patterns. Rather than applying the patterns in isolation, a complete design system can be composed of the patterns. This pattern-based system can significantly ease the development process of J2EE applications and improve the quality of the produced software. In this paper, we will show how a general architectural tool (Fred) can be used to model such a pattern system and to generate an architecture-centric environment for developing J2EE applications. The environment is a task-based wizard that guides the user through the development of the application by enforcing certain design rules.
A multilevel local mesh refinement projection method for low Mach number flows
Authors: Xavier Coré, Philippe Angot, Jean-Claude Latché
Venue: Mathematics and Computers in Simulation (2003)

This paper addresses a sub-problem of low Mach number reactive flows modelling: the solution of the mass and momentum balance equations for a pressure-independent variable density flow. For this objective, we develop a novel numerical scheme: the time discretisation is performed by an incremental projection method, using the original form of the mass balance equation for the projection step; the resulting two semi-discrete problems are then discretised in space by finite volumes on a MAC staggered mesh, with a multilevel local mesh refinement algorithm based on the Flux Interface Correction (FIC) method. The efficiency of this numerical scheme, which offers the opportunity to avoid computing with non-uniform grids or unstructured meshes, is assessed against a practical test case, specifically produced for this purpose.