ppxscal/embedding_network huggingface dataset:
Event Systems: How to Have Your Cake and Eat It Too
Authors: Patrick Th. Eugster, Pascal Felber, Rachid Guerraoui, S. B. Handurukande
Venue: Proceedings of the 22nd International Conference on Distributed Computing Systems (2002)

This paper addresses the fundamental tradeoffs in event systems between scalability (of event filtering, routing, and delivery mechanisms), expressiveness (when describing interests in events), and event safety (ensuring encapsulation and type-safe interaction with polymorphic events). We point out some ramifications underlying these tradeoffs and we propose a pragmatic approach to handle them. We achieve scalability using a multi-stage filtering strategy that combines approximate and perfect matching techniques for the purpose of event routing and filtering. We achieve expressiveness and event safety by viewing events as objects, i.e., instances of application-defined abstract types.
Indexing and the A-notation
Authors: M. P. Barnett
Venue: Communications of the ACM (1963)

Some methods of indexing sequentially stored elements of sparse multi-dimensional arrays are described in the scheme A notation.
Construction of new extremal self-dual codes
Authors: T. Aaron Gulliver, Masaaki Harada, Jon-Lark Kim
Venue: Discrete Mathematics (2003)

In this paper, new binary extremal self-dual codes are presented. A number of new extremal singly-even self-dual codes of lengths 48, 64 and 78, and extremal doubly-even self-dual codes of lengths 80 and 88, are constructed. We also relate an extremal doubly-even self-dual code of length divisible by 24 to an extremal singly-even self-dual code of that length. New singly-even self-dual codes of lengths 102 to 110 are also given.
A Dynamic HIV-Transmission Model for Evaluating the Costs and Benefits of Vaccine Programs
Authors: Donna M. Edwards, Ross D. Shachter, Douglas K. Owens
Venue: Interfaces (1998)

We developed a dynamic model of HIV transmission to evaluate the costs and benefits of HIV-vaccine programs in a population of homosexual men. We examined how changes in high-risk sexual behavior and the growth pattern of the epidemic influence the cost-effectiveness of preventive vaccines and of therapeutic vaccines. We found that the effect of reductions in condom use is more important for therapeutic vaccines than for preventive vaccines. Therapeutic vaccines may increase HIV seroprevalence in the population, unless the vaccine program is accompanied by increased condom use. Epidemic growth patterns also influence the cost-effectiveness of both vaccines, but the effects are more pronounced for preventive vaccines, which are more cost-effective in an early-stage epidemic than in a late-stage epidemic.
A tangible interface for IP network simulation
Authors: Kazue Kobayashi, Mitsunori Hirano, Atsunobu Narita, Hiroshi Ishii
Venue: CHI '03 extended abstracts on Human factors in computing systems (2003)

We present the IP Network Design Workbench which supports collaborative network design and simulation by a group of experts and customers. This system is based on a tangible user interface platform called "Sensetable," which can wirelessly detect the location and orientation of physical pucks. Using this system, users can directly manipulate network topologies, control parameters of nodes and links using physical pucks on the sensing table, and simultaneously see the simulation results projected onto the table in real-time.
Structural invariance of spatial Pythagorean hodographs
Authors: Rida T. Farouki, Mohammad al-Kandari, Takis Sakkalis
Venue: Computer Aided Geometric Design (2002)

The structural invariance of the four-polynomial characterization for three-dimensional Pythagorean hodographs introduced by Dietz et al. (1993), under arbitrary spatial rotations, is demonstrated. The proof relies on a factored-quaternion representation for Pythagorean hodographs in three-dimensional Euclidean space--a particular instance of the "PH representation map" proposed by Choi et al. (2002)--and the unit quaternion description of spatial rotations. This approach furnishes a remarkably simple derivation for the polynomials u'(t), v'(t), p'(t), q'(t) that specify the canonical form of a rotated Pythagorean hodograph, in terms of the original polynomials u(t), v(t), p(t), q(t) and the angle θ and axis n of the spatial rotation. The preservation of the canonical form of PH space curves under arbitrary spatial rotations is essential to their incorporation into computer-aided design and manufacturing applications, such as the contour machining of free-form surfaces using a ball-end mill and real-time PH curve CNC interpolators.
Demographic profiling: a euphemism for corporate spying
Authors: John Hudson
Venue: Ubiquity (2002)

Hands-on adoption of a multi-agent production planning technology in the manufacturing industry.
Usenet Nuggets
Authors: Mark Thorson
Venue: ACM SIGARCH Computer Architecture News (1990)

The PAX parallel processing project developed at the University of Tsukuba by T. Hoshino is summarized. PAX is a two dimensional array of processors which operate in MIMD form. QCDPAX has a fast floating point unit, specially programmed for QCD calculations. Peak performance is 14 Gigaflops.
Finding all solutions of nonlinear equations using the dual simplex method
Authors: Kiyotaka Yamamura, Tsuyoshi Fujioka
Venue: Journal of Computational and Applied Mathematics (2003)

Recently, an efficient algorithm has been proposed for finding all solutions of systems of nonlinear equations using linear programming. This algorithm is based on a simple test (termed the LP test) for nonexistence of a solution to a system of nonlinear equations using the dual simplex method. In this letter, an improved version of the LP test algorithm is proposed. By numerical examples, it is shown that the proposed algorithm could find all solutions of a system of 300 nonlinear equations in practical computation time.
Tutorial on Surrogate Constraint Approaches for Optimization in Graphs
Authors: Fred Glover
Venue: Journal of Heuristics (2003)

Surrogate constraint methods have been embedded in a variety of mathematical programming applications over the past thirty years, yet their potential uses and underlying principles remain incompletely understood by a large segment of the optimization community. In a number of significant domains of combinatorial optimization, researchers have produced solution strategies without recognizing that they can be derived as special instances of surrogate constraint methods. Once the connection to surrogate constraint ideas is exposed, additional ways to exploit this framework become visible, frequently offering opportunities for improvement.We provide a tutorial on surrogate constraint approaches for optimization in graphs, illustrating the key ideas by reference to independent set and graph coloring problems, including constructions for weighted independent sets which have applications to associated covering and weighted maximum clique problems. In these settings, the surrogate constraints can be generated relative to well-known packing and covering formulations that are convenient for exposing key notions. The surrogate constraint approaches yield widely used heuristics for identifying independent sets as simple special cases, and also afford previously unidentified heuristics that have greater power in these settings. Our tutorial also shows how the use of surrogate constraints can be placed within the context of vocabulary building strategies for independent set and coloring problems, providing a framework for applying surrogate constraints that can be used in other applications.At a higher level, we show how to make use of surrogate constraint information, together with specialized algorithms for solving associated sub-problems, to obtain stronger objective function bounds and improved choice rules for heuristic or exact methods. The theorems that support these developments yield further strategies for exploiting surrogate constraint relaxations, both in graph optimization and integer programming generally.
A trust-region algorithm for equality-constrained optimization via a reduced dimension approach
Authors: Jichang Dong, Jianming Shi, Shouyang Wang, Yi Xue, Shuqin Liu
Venue: Journal of Computational and Applied Mathematics (2003)

A trust-region algorithm is presented for solving optimization problem with equality constraints. The algorithm uses the Byrd--Omojokun scheme to compute the steps, and decompose the trial steps into two components: normal component and tangential component. But it differs from the Byrd--Omojokun algorithm with a reduced dimension approach in computing each tangential component. Global convergence of the proposed algorithm is proved under some mild assumptions. Three numerical examples are given to illustrate the efficiency of the algorithm.
Determining Production Schedules Under Base-Stock Policies in Single Facility Multi-Item Production Systems
Authors: Awi Federgruen, Ziv Katalan
Venue: Operations Research (1998)

In this paper we address periodic base-stock policies for stochastic economic lot scheduling problems. These represent manufacturing settings in which multiple items compete for the availability of a common capacity source, in the presence of setup times and/or costs, incurred when switching between items, and in the presence of uncertainty regarding demand patterns, production, and setup times. Under periodic base-stock policies, items are produced according to a given periodic item-sequence. This paper derives effective heuristics for the design of a periodic item-sequence minimizing system-wide costs. This sequence is constructed based on desirable production frequencies for the items, obtained as the solution of lower bound mathematical programs. An extensive numerical study gauges the quality of the proposed heuristics.
Simple Decentralized Feedback Strategies for Route Guidance in Traffic Networks
Authors: Yannis Pavlis, Markos Papageorgiou
Venue: Transportation Science (1999)

The paper presents a feedback route guidance strategy for complex, meshed traffic networks. Essential components of the strategy are simple, decentralized control laws of the bang-bang, P, or PI types that may be designed based on trial-and-error. Simulation investigations demonstrate the efficiency of the proposed strategy for two example networks under several scenarios of demand and incident conditions. Feedback route guidance, though exclusively based on measurable instantaneous travel times (no predictions, no demand nor origin-destination information are provided), is shown to equalize experienced travel times along any couple of used alternative routes in the network, and to considerably reduce travel delays compared to the no-control case.
A neuro-fuzzy system for ash property prediction
Authors: Giovanna Castellano, Ciro Castiello, Anna M. Fanelli, Michele Giovannini
Venue: Computational intelligence and applications (2002)

This paper proposes a neuro-fuzzy approach to solve the problem of predicting the property of ashes originated from combustion processes for electric generation. The adopted approach uses fuzzy logic for modeling as well as neural networks for extraction and optimization of the fuzzy model via learning from data. A two-phase learning strategy is adopted to determine the structure and parameters of the predictive model on the basis of experimental data derived from observation of different combustion processes. Preliminary results on the application of the proposed neuro-fuzzy approach are also reported.
ACTS: a multi-media contaminant transport modelling platform
Authors: M. M. Aral, M. L. Maslia, J. Guan
Venue: Development and application of computer techniques to environmental studies (2002)

In an attempt to determine if there are links between environmental pollution and increased risk to human health, the Agency for Toxic Substances and Disease Registry (ATSDR) conducts health assessments, health consultations, exposure investigations, and health studies. Quantifying the fate and transport of pollutants and the uncertainty associated with the analysis is a key step in these studies. To assist engineers and health scientists in conducting such analyses, ATSDR and the Multimedia Environmental Simulation Laboratory (MESL) program at Georgia Tech have developed software to assist with environmental multi-media fate and transport computations in a user-friendly environment. This software is identified as the "Analytical Contaminant Transport analysis System" (ACTS). In this paper, we describe general features of this software and the models contained therein. Further demonstration of the capabilities and use of ACTS software in site-specific cases can be found in other publications of the authors as referenced in this paper.
Coloring permutation graphs in parallel
Authors: Stavros D. Nikolopoulos
Venue: Discrete Applied Mathematics (2002)

A coloring of a graph G is an assignment of colors to its vertices so that no two adjacent vertices have the same color. We study the problem of coloring permutation graphs using certain properties of the lattice representation of a permutation and relationships between permutations, directed acyclic graphs and rooted trees having specific key properties. We propose an efficient parallel algorithm which colors an n-node permutation graph in O(log2 n) time using O(n2/log n) processors on the CREW PRAM model. Specifically, given a permutation π we construct a tree T*[π], which we call coloring-permutation tree, using certain combinatorial properties of π. We show that the problem of coloring a permutation graph is equivalent to finding vertex levels in the coloring-permutation tree.
A direct approach to control-flow sensitive region-based memory management
Authors: Fritz Henglein, Henning Makholm, Henning Niss
Venue: Proceedings of the 3rd ACM SIGPLAN international conference on Principles and practice of declarative programming (2001)

Region-based memory management can be used to control dynamic memory allocations and deallocations safely and efficiently. Existing (direct-style) region systems that statically guarantee region safety---no dereferencing of dangling pointers---are based on refinements of Tofte and Talpin's seminal work on region inference for managing heap memory in stacks of regions.We present a unified Floyd-Hoare Logic inspired region type system for reasoning about and inferring region-based memory management, using a sublanguage of imperative region commands. Our system expresses and performs control-sensitive region management without requiring a stack discipline for allocating and deallocating regions. Furthermore, it captures storage mode analysis and late allocation/early deallocation analysis in a single, expressive, unified logical framework. Explicit region aliasing in combination with reference-counted regions provides flexible, context-sensitive early memory deallocation and simultaneously dispenses with the need for an integrated region alias analysis.In this paper we present the design of our region type system, illustrate its practical expressiveness, compare it to existing region analyses, demonstrate how this eliminates the need for previously required source code rewritings for good memory performance, and describe automatic inference of region commands that give consistently better (or at least equally good) memory performance as existing inference techniques.
A Comparative Analysis of Hazardous Waste Remediation Alternatives
Authors: Ronald J. Toland, Jack M. Kloeber,  Jr., Jack A. Jackson
Venue: Interfaces (1998)

The US Department of Energy (DOE) has 136 contaminated nuclear-processing sites requiring remediation. Exploiting new remediation techniques will be critical to containing and treating this hazardous waste and to minimizing the estimated multibillion-dollar costs of cleanup. We combined system simulation, facility layout, stochastic life-cycle cost estimation, linear optimization, and various decision analysis techniques in a nine-month effort to give decision makers in the DOE realistic, flexible, and useful information to guide them in making decisions on Superfund remediation technology worth billions. A small team of students and instructors from the Air Force Institute of Technology used the majority of the techniques and tools taught at the institute to tackle this complex and important decision problem.
Managing a Customer Following a Target Reverting Policy
Authors: Srinagesh Gavirneni, Sridhar Tayur
Venue: Manufacturing Service Operations Management (1999)

We consider a stochastic, capacitated production-inventory model in which the customer provides information about the expected timing of future orders to the supplier. We allow for randomness in customer order arrivals as well as the quantity demanded, but work under the assumption that the customer is making every effort to follow the schedule provided. We term this as a target reverting policy. This gives rise to an interesting nonstationary inventory control model at the supplier. After characterizing the optimal policy, we develop solution procedures to compute the optimal parameters. An extensive computational study provides insights into the behavior of this model at optimality. Further, comparing the cost of the optimal policy to the cost of simple policies that either ignore the customer's information or the capacity constraint, we are able to provide insights as to when these simplifications could be costly.
Massive parallel processing for matrix multiplication: a systolic approach
Authors: D. J. Evans, C. R. Wan
Venue: Highly parallel computaions: algorithms and applications (2001)

In this chapter, we have designed nineteen systolic arrays for matrix multiplication under the framework of the systolic synthesis method using regular iterative algorithm (RIA) representation. Then we define different systolic array performance measures in order to evaluate the systolic designs. The performance of the designed systolic arrays is analysed in detail and this allows the comparison among the different systolic designs.
Examining gender differences in IT professionals' perceptions of job stress in response to technological change
Authors: Mike Gallivan
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 examines antecedents and consequences of IT professionals' perceptions of job stress within the context of assimilating a technological innovation in the workplace. Drawing on recent research on issues of gender within the IT profession (Ahuja 2002; Trauth 2002), as well as on recent studies into gender differences in workplace stress (Gardiner & Tiggeman 1999), we develop a conceptual framework to understand the phenomenon. We develop hypotheses about how the experiences of men and women IT professionals will differ in certain ways as they adopt and adapt to using a technological innovation. Using a mixed-method study of two firms that were adopting a technological innovation, we examine employees' reactions along gender lines. We found that perceived compatibility of the changes being assimilated was inversely related to employees' perceptions of stress for both men and women. While women experienced higher levels of stress and being overworked (as we predicted), there were also some unanticipated findings. Women IT professionals appeared to be more sensitive to the total number of elements in the work environment that were changing (total amount of change) as a precursor to stress. In the one firm where managers provided more autonomy but less supervision in adapting to the new technology, women reported considerably higher levels of stress. Based on both our expected and unexpected findings, we provide insights for IT practitioners to anticipate and manage workplace stress, and we offer future directions for researchers. We argue that our recommendations will allow employers to better accommodate the needs of a diverse workforce.
Optimizing Army Base Realignment and Closure
Authors: Sridhar Bashyam, Michael C. Fu, Robert F. Dell
Venue: Interfaces (1998)

In April 1997, the United States Army announced that savings had finally overtaken costs in closing or realigning 803 of its installations worldwide. This milestone occurred in the ninth year of a 13-year program approved by Congress and Presidents Reagan, Bush, and Clinton. The cost of this program is $5.3 billion, and when complete, the army expects annual savings of $996 million in perpetuity. A mixed-integer linear program, BRACAS (base realignment and closure action scheduler), helped the army budget for the 29 closures and 11 realignments approved by Congress and President Clinton in 1995. The army used BRACAS to schedule optimally the $2 billion in BRAC costs for these 40 installations over the six-year period mandated by Congress; associated annual savings will be $360 million.
A riverbank trove
Authors: David Kahn
Venue: Cryptologia (2002)

A proof with handwritten corrections by the author of William F. Friedman's Riverbank Publication No. 22, one of the most important documents in the evolution of cryptology, has been found at the New York Public Library.
Multi-Adaptive Galerkin Methods for ODEs I
Authors: Anders Logg
Venue: SIAM Journal on Scientific Computing (2002)

We present multi-adaptive versions of the standard continuous and discontinuous Galerkin methods for ODEs. Taking adaptivity one step further, we allow for individual time-steps, order and quadrature, so that in particular each individual component has its own time-step sequence. This paper contains a description of the methods, an analysis of their basic properties, and a posteriori error analysis. In the accompanying paper [A. Logg, SIAM J. Sci. Comput., submitted], we present adaptive algorithms for time-stepping and global error control based on the results of the current paper.
SoftGenLock: active stereo and genlock for PC cluster
Authors: Jérémie Allard, Valérie Gouranton, Guy Lamarque, Emmanuel Melin, Bruno Raffin
Venue: Proceedings of the workshop on Virtual environments 2003 (2003)

In this paper, we present SoftGenLock, an open source software that enables genlock and active stereo on commodity graphics cards. SoftGenLock is implemented on top of Linux. It does not require any hardware modification of the graphics card. Rather than to gain total control on signal generation, which would make the software deeply dependent on the graphics card specification, SoftGenLock applies continuous small modifications to converge and maintain genlocked video signals. To be properly synchronized with each video retrace, SoftGenLock is executed as a real-time task. The genlock signal is propagated along the different machines using the parallel port, a low latency device present on all PCs. It results in a software that only requires access to few specific registers on a graphics card: it can be ported with minimal effort on potentially any graphics card.
Head tracking using stereo
Authors: Daniel B. Russakoff, Martin Herman
Venue: Machine Vision and Applications (2002)

Head tracking is an important primitive for smart environments and perceptual user interfaces where the poses and movements of body parts need to be determined. Most prevaous solutions to this problem are based on intensity images and, as a result, suffer from a host of problems including sensitivity to background clutter and lighting variations. Our approach avoids these pitfalls by using stereo depth data together with a simple human-torso model to create a head-tracking system that is both fast and robust. We use stereo data1 to derive a depth model of the background that is then employed to provide accurate foreground segmentation. We then use directed local edge detectors on the foreground to find occluding edges that are used as features to fit to a torso model. Once we have the model parameters, the location and orientation of the head can be easily estimated. A useful side effect from using stereo data is the ability to track head movement through a room in three dimensions. Experimental results on real image sequences are given.