ppxscal/embedding_network huggingface dataset:
Achieving Air Quality Standards in the European Union
Authors: Zeger Degraeve, Gert Jan Koopman
Venue: Operations Research (1998)

This paper develops a methodology to select a least cost mix of transport policy measures in different regions of the European Union to attain air quality standards by the year 2010. Two fundamental characteristics of air quality problems are addressed: their variation across regions and the interregional linkages resulting from ozone pollution. We propose a column generation approach to answer the question of which policies should be introduced where to arrive at a least cost solution for the Union as a whole satisfying the emissions reduction constraints. Our methodology can be applied to a wide range of environmental policy questions with a spatial dimension characterized by interdependencies across policy instruments and environmental processes. Improvements in vehicle technology are important for meeting air quality standards. Triggering such changes through economic instruments is attractive because this accommodates the geographical variation of air quality problems throughout the European Union. Different clean fuels are suggested for different regions. Taxation on road use also plays an important role in the mix of policies to curb air pollution. Furthermore, emissions reduction from nontransport sources are of major importance in all scenarios studied.
Matching graphs by pivoting
Authors: Alessio Massaro, Marcello Pelillo
Venue: Pattern Recognition Letters (2003)

Motivated by a recent (continuous) quadratic formulation, in this paper we present a pivoting-based heuristic for graph matching based on the corresponding linear complementarity problem. Experiments are presented which demonstrate the potential of the proposed method.
Evaluation and optimisation of integrated manufacturing system operations using Taguch's experiment design in computer simulation
Authors: Chi-Sheng Tsai
Venue: Computers and Industrial Engineering (2002)

The application of computer simulation have been proposed and implemented to solve the problems of variation in integrated manufacturing systems. However, a simulation model only acts as a tool in examining performance. It is essentially a trial and error methodology, and does not directly provide explanations for observed system behaviours. Therefore, in this paper the use of Taguchi's Experiment Design in simulation is studied to solve decision-making problems in integrated manufacturing systems. In particular, we use the case of a steel soakingpit/rolling-mill plant to demonstrate how the approach works. The results reveal that this approach can take into account the evaluation and optimisation of operating conditions in complex systems simultaneously.
GOALI: A National Science Foundation University-Industry Liaison Program
Authors: Louis A. Martin-Vega, Lawrence M. Seiford, Donald Senich
Venue: Interfaces (2002)

A major objectiveof theNational ScienceFoundation (NSF) is to improve the nation's capacity for intellectual and economic growth. It does this by supporting the discovery of new knowledge and the enhancement of a skilled workforce. Both outcomes are supported by the different mechanisms of industry-university linkages available in NSF's GOALI initiative. By addressing long-term, generic research within an intellectual envelope shared by the industrial partner, the intellectual capital of academe and emerging technologies from industry are brought together in ways that increase the value to both partners. Industry can leverage its research investment, and university researchers can gain access to new technical challenges.
Axiomatic characterizations of threshold choice functions for comparison functions
Authors: Somdeb Lahiri
Venue: Fuzzy Sets and Systems (2002)

In this paper we characterize the threshold choice functions associated with comparison functions (= reciprocal fuzzy relations), a special of which is the Orlovsky choice function (with threshold ½). Our family of threshold choice functions is somewhat larger than the family of choice functions which select only those alternatives that secure a certain pre-specified proportion of the votes against all other alternatives. Our family of threshold choice functions also include ones which select only those alternatives that exceed a certain pre-specified proportion of the votes against all other alternatives. This is the price we pay for omitting continuity from our axiomatic characterizations.
Entropy maximisation and open queueing networks with priorities and blocking
Authors: Demetres Kouvatsos, Irfan Awan
Venue: Performance Evaluation (2003)

A review is carried out on the characterisation and algorithmic implementation of an extended product-form approximation, based on the principle of maximum entropy (ME), for a wide class of arbitrary finite capacity open queueing network models (QNMs) with service and space priorities. A single server finite capacity GE/GE/1/N queue with R (R < 1) distinct priority classes, compound Poisson arrival processes (CPPs) with geometrically distributed batches and generalised exponential (GE) service times is analysed via entropy maximisation, subject to suitable GE-type queueing theoretic constraints, under preemptive resume (PR) and head-of-line (HOL) scheduling rules combined with complete buffer sharing (CBS) and partial buffer sharing (PBS) management schemes stipulating a sequence of buffer thresholds {N = (N1, ..., NR), 0 > Ni ≤ Ni-1, i = 2 ..., R}. The GE/GE/1/N queue is utilised, in conjunction with GE-type first two moment flow approximation formulae, as a cost-effective building block towards the establishment of a generic ME queue-by-queue decomposition algorithm for arbitrary open QNMs with space and service priorities under repetitive service blocking with random destination (RS-RD). Typical numerical results are included to illustrate the credibility of the ME algorithm against simulation for various network topologies and define experimentally pessimistic GE-type performance bounds. Remarks on the extensions of the ME algorithm to other types of blocking mechanisms, such as repetitive service blocking with fixed destination (RS-FD) and blocking-after-service (BAS), are included.
Quantifying the correlation between two internal-valued random sets
Authors: Manuel Montenegro, María Ángeles Gil, María Teresa López, María Asunción Lubiano
Venue: Technologies for constructing intelligent systems: tools (2002)

The aim of this paper is to develop a study on the correlation of two interval-valued random sets when we consider either a linear relation or an affine function between them.
Self-designing structures
Authors: J. W. Bull, Z. Pitouras
Venue: Civil and structural engineering computing: 2001 (2001)

The research program entitled 'Self-Designing Structures' has developed a suite of computer programs capable of both two and three-dimensional topological optimisation. The Self-Designing Structures optimisation research models the natural behaviour of bone where, when stressed, the bone adds material and when not stressed, the bone discards material. The Self-Designing Structures program uses a similar methodology, but based on the iterative use of finite elements. The structure is reshaped and remeshed at each design iteration. The major output of the research is the EMERGE program. This paper presents an outline of some of the algorithms developed and presents the results of problem solved using the Self-Designing Structures optimisation method. The Self-Designing Structures methodology has been successfully applied to a number of practical industrial engineering problems.
The number of 2-edge-colored complete graphs with unique Hamiltonian alternating cycle
Authors: A. Benkouar, Y. Manoussakis, R. Saad
Venue: Discrete Mathematics (2003)

Let G be a 2-edge-colored complete graph of even order n. A cycle of G is alternating if any two successive edges differ in color. We prove that there is a one-to-one correspondence between the set of bipartite tournaments of order n admitting a unique Hamiltonian cycle and the set of 2-edge-colored complete graphs of order n admitting a unique alternating Hamiltonian cycle.
Design guidelines for robust Internet protocols
Authors: Tom Anderson, Scott Shenker, Ion Stoica, David Wetherall
Venue: ACM SIGCOMM Computer Communication Review (2003)

Robustness has long been a central design goal of the Internet. Much of the initial effort towards robustness focusedon the "fail-stop" model, where node failures are complete and easily detectable by other nodes. The Internet is quite robust against such failures, routinely surviving various catastrophes with only limited outages. This robustness is largely due to the widespread belief in a set of guidelines for critical design decisions such as where to initiate recovery and how to maintain state.However, the Internet remains extremely vulnerable to more arbitrary failures where, through either error or malice, a node issues syntactically correct responses that are not semantically correct. Such failures, some as simple as misconfigured routing state, can seriously undemnine the functioning of the Internet. With the Internet playing such a central role in the global telecommunications infrastructure, this level of vulnerability is no longer acceptable.In this paper we argue that to make the Internet more robust to these kinds of arbitrary failures, we need to change the way we design network protocols. To this end, we propose a set of six design guidelines for improving the network protocol design. These guidelines emerged from a study of past examples of failures, and determining what could have been done to prevent the problem from occurring in the first place. The unifying theme behind the various guidelines is that we need to design protocols more defensively, expecting malicious attack, misimplementation, and misconfiguration at every turn.
A Dynamic Stochastic Stock-Cutting Problem
Authors: Elena V. Krichagina, Rodrigo Rubio, Michael I. Taksar, Lawrence M. Wein
Venue: Operations Research (1998)

We consider a stock cutting problem for a paper plant that produces sheets of various sizes for a finished goods inventory that services random customer demand. The controller decides when to shut down and restart the paper machine and how to cut completed paper rolls into sheets of paper. The objective is to minimize long-run expected average costs related to paper waste (from inefficient cutting), shutdowns, backordering, and holding finished goods inventory. A two-step procedure (linear programming in the first step and Brownian control in the second step) is developed that leads to an effective, but suboptimal, solution. The linear program greatly restricts the number of cutting configurations that can be employed in the Brownian analysis, and hence the proposed policy is easy to implement, and the resulting production process is considerably simplified. In an illustrative numerical example using representative data from an industrial facility, the proposed policy outperforms several policies that use a larger number of cutting configurations. Finally, we discuss some alternative production settings where this two-step procedure may be applicable.
Inclusion of solutions of Darboux problems for quasilinear hyperbolic equations
Authors: M. Koeber
Venue: Journal of Computational and Applied Mathematics (2003)

We deal with the characteristic initial value problem for a hyperbolic differential equation a(x,y,u)uxx + b(x,y,u)uxy + c(x,y,u)uyy = f(x,y,u,ux,uy). The paper presents a method which yields pointwise enclosures of the domain of determinacy M (depending implicitly on u) and of the corresponding solution u(x,y), (x,y) ∈ M. The method has been implemented on a computer using machine interval arithmetic.
An improved genetic algorithm for facility layout problems having inner structure walls and passages
Authors: Kyu-Yeul Lee, Seong-Nam Han, Myung-Il Roh
Venue: Computers and Operations Research (2003)

This study proposes an improved genetic algorithm (GA) to derive solutions for facility layouts that are to have inner walls and passages. The proposed algorithm models the layout of facilities on gene structures. These gene structures consist of a four-segmented chromosome. Improved solutions are produced by employing genetic operations known as selection, crossover, inversion, mutation, and refinement of these genes for successive generations. All relationships between the facilities and passages are represented as an adjacency graph. The shortest path and distance between two facilities is calculated using Dijkstra's algorithm of graph theory. Comparative testing shows that the proposed algorithm performs better than other existing algorithms for the optimal facility layout design. Finally, the proposed algorithm is applied to ship compartment layout problems with the computational results compared with an actual ship compartment layout.
Delivering cutting edge OOP curriculum in a time of resource reduction (without sacrificing quality)
Authors: Sharon N. Vest, David D. Langan
Venue: Journal of Computing Sciences in Colleges (2003)

Consistently delivering cutting edge OOP curriculum and instruction in the computer science discipline in times of economic constraint is an on-going challenge. This paper outlines the modifications made by one institution to the curriculum and delivery of the CS1 sequence in a time of reduced resources. Constraints leading to the compromises are discussed, as are the consequences that resulted. The process of continuously modifying the program based on feedback from faculty, students and graduate assistants directly involved in the course is described. Local impact of two delivery strategies on student attrition rates is presented. Recommendations for course management are provided as well as lessons learned for those faced with similar resource constraints.
A Design-for-Verification Technique for Functional Pattern Reduction
Authors: Chien-Nan Jimmy Liu, I-Ling Chen, Jing-Yang Jou
Venue: IEEE Design Test (2003)

This technique reduces the number of required functional patterns by first defining conditions for hard-to-control (HTC) code in a hardware-description-language design and then using an algorithm to detect such code automatically. A second algorithm eliminates these HTC points by selecting a minimum number of nodes for control point insertion.
Practical lessons from experience with the database design course project
Authors: Sharon M. Tuttle
Venue: Journal of Computing Sciences in Colleges (2002)

In a typical database design and implementation course, it is not unusual to have a course project. This paper describes the evolution of such a project within such a course over eight semesters; I wish I had "known then what I know now", so to speak, and so it is hoped that this description will help others newly assigned to such a course, or might encourage further discussion of how to make such projects better experiences for students and instructor alike.
On Polynomial-Factor Approximations to the Shortest Lattice Vector Length
Authors: Ravi Kumar, D. Sivakumar
Venue: SIAM Journal on Discrete Mathematics (2003)

For every constant $\epsilon > 0$, we obtain a $2^{O(n(1/2 + 1/\epsilon))}$ time randomized algorithm to approximate the length of the shortest vector in an n-dimensional lattice to within a factor of $n^{3 + \epsilon}$.
Software systems for tabular data releases
Authors: Adrian Dobra, Alan F. Karr, Ashish P. Sanil, Stephen E. Fienberg
Venue: International Journal of Uncertainty, Fuzziness and Knowledge-Based Systems (2002)

We describe two classes of software systems that release tabular summaries of an underlying database. Table servers respond to user queries for (marginal) sub-tables of the "full" table summarizing the entire database, and are characterized by dynamic assessment of disclosure risk, in light of previously answered queries. Optimal tabular releases are static releases of sets of sub-tables that are characterized by maximizing the amount of information released, as given by a measure of data utility, subject to a constraint on disclosure risk. Underlying abstractions - primarily associated with the query space, as well as released and unreleasable sub-tables and frontiers, computational algorithms and issues, especially scalability, and prototype software implementations are discussed.
Non-Approximability Results for Scheduling Problems with Minsum Criteria
Authors: Han Hoogeveen, Petra Schuurman, Gerhard J. Woeginger
Venue: INFORMS Journal on Computing (2001)

We provide several non-approximability results for deterministic scheduling problems whose objective is to minimize the total job completion time. Unless , none of the problems under consideration can be approximated in polynomial time within arbitrarily good precision. Most of our results are derived by APX-hardness proofs.We show that, whereas scheduling on unrelated machines with unit weights is polynomially solvable, the problem becomes APX-hard if release dates or weights are added. We further show APX-hardness for scheduling in flow shops, job shops, and open shops. We also investigate the problems of scheduling on parallel machines with precedence constraints and unit processing times, and two variants of the latter problem with unit communication delays; for these problems we provide lower bounds on the worst-case behavior of any polynomial-time approximation algorithm through the gap-reduction technique.
Women talking about IT work: duality or dualism?
Authors: Sue. H. Nielsen, Liisa A. von Hellens, Jenine Beekhuyzen, Eileen M. Trauth
Venue: Proceedings of the 2003 SIGMIS conference on Computer personnel research: Freedom in Philadelphia--leveraging differences and diversity in the IT workforce (2003)

This paper explores the way that professional women working in the IT industry discuss the nature of their work. The research is part of an ongoing project (WinIT) commenced in 1995, which seeks to understand the declining female participation in IT education and work. An examination of our interview data using concepts from Giddens' structuration theory shows that a number of dualisms provide the women with interpretive schemes through which they can interpret and make sense of their working lives. Such dualisms may provide ontological security as representations of the routines which women in the IT industry enact in their daily activities. This paper suggests that the way women talk about their work reinforces widely held impressions of the IT industry. The use of structuration theory helps show how this talk is not always consistent with the womens' lived experiences. The interviews reveal contradictions in these dualisms, indicating that these polarised views of women and IT work are being undermined by women in the IT industry. In order to understand better how women help configure the institutional realm of IT work, we propose that more qualitative studies of women at work in IT as well as women talking about IT are needed.
Representing vertex-based simplicial multi-complexes
Authors: Emanuele Danovaro, Leila De Floriani, Paola Magillo, Enrico Puppo
Venue: Digital and image geometry: advanced lectures (2001)

In this paper, we consider the problem of representing a multiresolution geometric model, called a Simplicial Multi-Complex (SMC), in a compact way. We present encoding schemes for both two- and three-dimensional SMCs built through a vertex insertion (removal) simplification strategy. We show that a good compression ratio is achieved not only with respect to a general-purpose data structure for a SMC, but also with respect to just encoding the complex at the maximum resolution.
The World Wide Web: Opportunities for Operations Research and Management Science
Authors: Hemant K. Bhargava, Ramayya Krishnan
Venue: INFORMS Journal on Computing (1998)

The World Wide Web has already affected OR/MS work in a significant way, and holds great potential for changing the nature of OR/MS products and the OR/MS software economy. Web technologies are relevant to OR/MS work in two ways. First, the Web is a multimedia communication system. Originally based on an information pull model, it is-critically for OR/MS-being extended for information push as well. Second, it is a large distributed computing environment in which OR/MS products-interactive computational applications-can be made available, and interacted with, over a global network. Enabling technologies for Web-based execution of OR/MS applications are classified into those involving client-side execution and server-side execution. Methods for combining multiple client-side and server-side technologies are critical to OR/MS's use of these technologies. These methods, and various emerging technologies for developing computational applications, give the OR/MS worker a rich armament for building Web-based versions of conventional applications. They also enable a new class of distributed applications working on real-time data. Web technologies are expected to encourage the development of OR/MS products as specialized component applications that can be bundled to solve real-world problems. Effective exploitation, for OR/MS purposes, of these technological innovations will also require initiatives, changes, and greater involvement by OR/MS organizations.
An alternative definition for fuzzy interval orders
Authors: Ahmed Bufardi
Venue: Fuzzy Sets and Systems (2003)

The class of interval orders is one of the most studied classes of preference structures without incomparability in the theory of classical preference modelling. In this paper, we propose a generalization of the classical definition of interval order and strict interval order. We focus our attention on two important classes of interval orders and strict interval orders which are, respectively, defined by means of a strong De Morgan triplet and a min-max De Morgan triplet.
Multiscale Bases for the Sparse Representation of Boundary Integral Operators on Complex Geometry
Authors: Johannes Tausch, Jacob White
Venue: SIAM Journal on Scientific Computing (2002)

A multilevel transform is introduced to represent discretizations of integral operators from potential theory by nearly sparse matrices. The new feature presented here is to construct the basis in a hierarchical decomposition of the three-space and not, as in previous approaches, in a parameter space of the boundary manifold. This construction leads to sparse representations of the operator even for geometrically complicated, multiply connected domains. We will demonstrate that the numerical cost to apply a vector to the operator using the nonstandard form is essentially equal to performing the same operation with the fast multipole method. With a second compression scheme the multiscale approach can be further optimized. The diagonal blocks of the transformed matrix can be used as an inexpensive preconditioner which is empirically shown to reduce the condition number of discretizations of the single layer operator so as to be independent of mesh size.
Direct numerical identification of boundary values in the Laplace equation
Authors: Keisuke Hayashi, Kazuei Onishi, Yoko Ohura
Venue: Journal of Computational and Applied Mathematics (2003)

An inverse boundary value problem for the Laplace equation is considered. The Dirichlet and the Neumann data are prescribed on respective part of the boundary, while there is the second part of the boundary where no boundary data are given. There is the third part of the boundary where the Robin condition is prescribed. This ill-posed problem of finding unknown values along the whole boundary is reformulated in terms of the variational problem, which is then recast into primary and adjoint boundary value problems of the Laplace equation in conventional forms. A direct method for numerical solution of the boundary value problems using the boundary element method is presented.