ppxscal/embedding_network huggingface dataset:
A Stochastic Branch-and-Bound Approach to Activity Crashing in Project Management
Authors: W. J. Gutjahr, C. Strauss, E. Wagner
Venue: INFORMS Journal on Computing (2000)

Many applications such as project scheduling, workflow modeling, or business process re-engineering incorporate the common idea that a product, task, or service consisting of interdependent time-related activities should be produced or performed within given time limits. In real-life applications, certain measures like the use of additional manpower, the assignment of highly-skilled personnel to specific jobs, or the substitution of equipment are often considered as means of increasing the probability of meeting a due date and thus avoiding penalty costs. This paper investigates the problem of selecting, from a set of possible measures of this kind, the combination of measures that is the most cost-efficient. Assuming stochastic activity durations, the computation of the optimal combination of measures may be very expensive in terms of runtime. In this article, we introduce a powerful stochastic optimization approach to determine a set of efficient measures that crash selected activities in a stochastic activity network. Our approach modifies the conventional Stochastic Branch-and-Bound, using a heuristic--instead of exact methods--to solve the deterministic subproblem. This modification spares computational time and by doing so provides an appropriate method for solving various related applications of combinatorial stochastic optimization. A comparative computational study shows that our approach not only outperforms standard techniques but also definitely improves conventional Stochastic Branch-and-Bound.
Parallel computing with load balancing on heterogeneous distributed systems
Authors: Primoz Rus, Boris Stok, Nikolaj Mole
Venue: Advances in Engineering Software (2003)

In the present work, the parallelization of the solution of a system of linear equations, in the framework of finite element computational analyses, is dealt with. As the substructuring method is used, the basic idea refers to a way of decomposing the considered spatial domain, discretized by the finite elements, into a finite set of non-overlapping subdomains, each assigned to an individual processor and computationally analysed in parallel. Considering the fact that Personal Computers and Work Stations are still the most frequently used computers, a parallel computational platform can be built by connecting the available computers into a computer network. The incorporated computers being usually of different computational power and memory size, the efficiency of parallel computations on such a heterogeneous distributed system depends mainly on proper load balance. To cope the balance problem, an algorithm for the efficient load balance for structured and free 2D quadrilateral finite element meshes based on the rearrangement of elements among respective subdomains, has been developed.
Automatic scientific text classification using local patterns: KDD CUP 2002 (task 1)
Authors: Moustafa M. Ghanem, Yike Guo, Huma Lodhi, Yong Zhang
Venue: ACM SIGKDD Explorations Newsletter (2002)

In this paper, we describe our approach for addressing Task 1 in the KDD CUP 2002 competition. The approach is based on developing and using an improved automatic feature selection method in conjunction with traditional classifiers. The feature selection method used is based on capturing frequently occurring keyword combinations (or motifs) within short segments of the text of a document and has proved to produce more accurate classification results than approaches relying solely on using keyword-based features.
Information Theory and the Finite-Time Behavior of the Simulated Annealing Algorithm: Experimental Results
Authors: Mark Fleischer, Sheldon H. Jacobson
Venue: INFORMS Journal on Computing (1999)

This article presents an empirical approach that demonstrates a theoretical connection between (information theoretic) entropy measures and the finite-time performance of the simulated annealing algorithm. The methodology developed leads to several computational approaches for creating problem instances useful in testing and demonstrating the entropy/performance connection: use of generic configuration spaces, polynomial transformations between NP-hard problems, and modification of penalty parameters. In particular, the computational results show that higher entropy measures are associated with superior finite-time performance of the simulated annealing algorithm.
Competitive foraging, decision making, and the ecological rationality of the matching law
Authors: Anil K. Seth
Venue: Proceedings of the seventh international conference on simulation of adaptive behavior on From animals to animats (2002)

The matching law describes how individual foragers often allocate their choices, occasionally suboptimally, in experimental situations. The 'ideal free distribution' predicts how groups of foraging agents should distribute themselves, optimally, over patchy environments. This paper explores the possibility that a single behavioural heuristic can account for both phenomena, allowing the potential suboptimality of matching to be understood in terms of adaptation to a group context. Two simple heuristics are compared, ε-sampling and ω-sampling: the latter is successful in both cases, but contrary to prior claims in the literature the former is successful in neither. These results emphasise the importance of multiple environmental value estimates in effective decision making.
Two stack dynamic memory allocation
Authors: Gordon Bassen, Issak Garber
Venue: Journal of Computing Sciences in Colleges (2002)

A new technique in the creation of the stack frame of a function has been developed with the capability of storing dynamic variables in the same area as local variables. This innovation permits the writing of an array declaration in C/C++ type languages, such as: int arr[n]; to be used within a function in the cases where: 1) n is a constant or, 2) n is a variable with a run time calculated value. Stack allocation as it is currently implemented, allows for run-time variable storing only when a function is called (activated). It does not permit changing the size of the area while the function is executing. This paper illustrates how this disadvantage can be overcome. As a result existence of the heap may no longer be necessary. Furthermore, the authors have developed the capability within object-oriented languages of passing dynamically allocated variables or arrays to the calling function. A high-level language which uses this method of compiling will be simpler, and have the ability to create more compact, efficient, and effective code without losing the strengths and capabilities of existent languages.
Pressure vessels under external pressure
Authors: C. T. F. Ross
Venue: Civil and structural engineering computing: 2001 (2001)

This paper commences by describing the different modes of failure of submarine pressure hulls under external hydrostatic pressure. The importance of attempting to conquer the oceans' bottoms is also described. The paper then gives a brief history of the development of submarines and this is followed by descriptions of novel submarine pressure hulls and modem structural materials, which will enable large structures to dive to great depths, not achieved at present; both commercial and military applications of submarines are considered. Finally, the noise and vibration of submarines are looked at, and the author shows how noise can be reduced to create a stealth submarine, powered by a quiet fuel cell.
About the sharpness of the stability estimates in the Kreiss matrix theorem
Authors: M. N. Spijker, S. Tracogna, B. D. Welfert
Venue: Mathematics of Computation (2003)

One of the conditions in the Kreiss matrix theorem involves the resolvent of the matrices A under consideration. This so-called resolvent condition is known to imply, for all n ≥ 1, the upper bounds ||An|| ≤ eK(N + 1) and ||An|| ≤ eK(n + 1). Here || . || is the spectral norm. K is the constant occurring in the resolvent condition, and the order of A is equal to N + 1 ≥ 1.It is a long-standing problem whether these upper bounds can be sharpened, for all fixed K < 1, to bounds in which the right-hand members grow much slower than linearly with N + 1 and with n + 1, respectively. In this paper it is shown that such a sharpening is impossible. The following result is proved: for each e < 0, there are fixed values C < 0, K < 1 and a sequence of (N + 1) × (N + 1) matrices AN, satisfyirig the resolvent condition, such that ||(AN)n|| ≥ C(N + 1)1-ε = C(n + 1)1-ε for N = n = 1,2,3,....The result proved in this paper is also relevant to matrices A whose ε-pseudospectra lie at a distance not exceeding Kε from the unit disk for all ε < 0.
Recent developments in toroid cavity autoclave engineering
Authors: Heiko G. Niessen, Peter Trautner, Rolf Backhausen, Klaus Woelk
Venue: Concepts in Magnetic Resonance: an Educational Journal (2003)

A toroid cavity autoclave (TCA) is a metal pressure vessel that simultaneously functions as an NMR resonator. Since the introduction of the TCA concept, many adaptations and optimizations were put together to suit particular applications such as catalysis in supercritical fluids, rotating-frame imaging of materials, and evaluation of transport phenomena. In this article, we present recent achievements in TCA engineering that were carried out for both major fields of research with TCAs, i.e., high-pressure and imaging studies. A new modular TCA design is introduced that makes it possible to easily access all individual parts of the autoclave for maintenance and replacement. The TCA is double tuned to a high frequency for 1H and 19F resonances and a low frequency for hetero nuclei. It withstands pressures up to 400 bar at room temperature and 300 bar at temperatures up to 100°C. The autoclave sample volume is electrically separated into two compartments with only the lower compartment NMR sensitive. With the two-compartment TCA, it is possible to monitor multiple-phase systems or gas/liquid reactions in situ without sacrificing high-resolution qualities of the probe. In addition, special features are presented, such as the utilization of a second pressure line for injecting key reagents that initiate a chemical reaction or for vigorously mixing gases with a reactive solution. A newly designed resistive heater that does not introduce stray magnetic fields is also described.
Separation of concerns for software evolution
Authors: Tom Mens, Michel Wermelinger
Venue: Journal of Software Maintenance: Research and Practice (2002)

This special issue reports on approaches that apply the idea of separation of concerns to software evolution. In this context, separation of concerns allows us to separate parts of the software that exhibit different rates of change or different types of change. This makes it possible to provide better evolution support for those parts that have a higher change rate, or to provide different evolution techniques for different views on the software. Another common way to achieve separation of concerns is by raising the level of abstraction to the level of software architectures, business rules and metamodels. This makes software evolution more manageable. The above ideas emerged as important conclusions of the workshop on Formal Foundations of Software Evolution, which was co-located with the Conference on Software Maintenance and Re-engineering in Lisbon in March 2001. Of the 12 original position papers, five have been selected for revision and inclusion in this special issue of the Journal of Software Maintenance and Evolution.
Decision Making with Monotone Lower Probabilities of Infinite Order Fabrice
Authors: Fabrice Philippe, Gabriel Debs, Jean-Yves Jaffray
Venue: Mathematics of Operations Research (1999)

Properties of convex and monotone capacities of infinite order in Polish spaces are studied and used to justify the representation of certain situations of imprecise risk (imprecisely known probabilities) by lower probabilities, which are monotone of infinite order. Decision making with imprecise risk is then modeled, and linear utility theory is shown to be generalizable to the case of imprecise risk.
Executing multiple pipelined data analysis operations in the grid
Authors: Matthew Spencer, Renato Ferreira, Michael Beynon, Tahsin Kurc, Umit Catalyurek, Alan Sussman, Joel Saltz
Venue: Proceedings of the 2002 ACM/IEEE conference on Supercomputing (2002)

Processing of data in many data analysis applications can be represented as an acyclic, coarse grain data flow, from data sources to the client. This paper is concerned with scheduling of multiple data analysis operations, each of which is represented as a pipelined chain of processing on data. We define the scheduling problem for effectively placing components onto Grid resources, and propose two scheduling algorithms. Experimental results are presented using a visualization application.
Discovering cluster-based local outliers
Authors: Zengyou He, Xiaofei Xu, Shengchun Deng
Venue: Pattern Recognition Letters (2003)

In this paper, we present a new definition for outlier: cluster-based local outlier, which is meaningful and provides importance to the local data behavior. A measure for identifying the physical significance of an outlier is designed, which is called cluster-based local outlier factor (CBLOF). We also propose the FindCBLOF algorithm for discovering outliers. The experimental results show that our approach outperformed the existing methods on identifying meaningful and interesting outliers.
Matlab implementation of the finite element method in elasticity
Authors: J. Alberty, C. Carstensen, S. A. Funken, R. Klose
Venue: Computing (2002)

A short Matlab implementation for P1 and Q1 finite elements (FE) is provided for the numerical solution of 2d and 3d problems in linear elasticity with mixed boundary conditions. Any adaptation from the simple model examples provided to more complex problems can easily be performed with the given documentation. Numerical examples with postprocessing and error estimation via an averaged stress field illustrate the new Matlab tool and its flexibility.
An Integrated Approach to Parallel Scheduling Using Gang-Scheduling, Backfilling, and Migration
Authors: Yanyong Zhang, Hubertus Franke, Jose Moreira, Anand Sivasubramaniam
Venue: IEEE Transactions on Parallel and Distributed Systems (2003)

Effective scheduling strategies to improve response times, throughput, and utilization are an important consideration in large supercomputing environments. Parallel machines in these environments have traditionally used space-sharing strategies to accommodate multiple jobs at the same time by dedicating the nodes to a single job until it completes. This approach, however, can result in low system utilization and large job wait times. This paper discusses three techniques that can be used beyond simple space-sharing to improve the performance of large parallel systems. The first technique we analyze is backfilling, the second is gang-scheduling, and the third is migration. The main contribution of this paper is an analysis of the effects of combining the above techniques. Using extensive simulations based on detailed models of realistic workloads, the benefits of combining the various techniques are shown over a spectrum of performance criteria.
Evaluating a scientific collaboratory: Results of a controlled experiment
Authors: Diane H. Sonnenwald, Mary C. Whitton, Kelly L. Maglaughlin
Venue: ACM Transactions on Computer-Human Interaction (TOCHI) (2003)

The evaluation of scientific collaboratories has lagged behind their development. Do the capabilities afforded by collaboratories outweigh their disadvantages? To evaluate a scientific collaboratory system, we conducted a repeated-measures controlled experiment that compared the outcomes and process of scientific work completed by 20 pairs of participants (upper level undergraduate science students) working face-to-face and remotely. We collected scientific outcomes (graded lab reports) to investigate the quality of scientific work, post-questionnaire data to measure the adoptability of the system, and post-interviews to understand the participants' views of doing science under both conditions. We hypothesized that study participants would be less effective, report more difficulty, and be less favorably inclined to adopt the system when collaborating remotely. Contrary to expectations, the quantitative data showed no statistically significant differences with respect to effectiveness and adoption.The qualitative data helped explain this null result: participants reported advantages and disadvantages working under both conditions and developed work-arounds to cope with the perceived disadvantages of collaborating remotely. While the data analysis produced null results, considered as a whole, the analysis leads us to conclude there is positive potential for the development and adoption of scientific collaboratory systems.
The Reconstruction of Doubled Genomes
Authors: Nadia El-Mabrouk, David Sankoff
Venue: SIAM Journal on Computing (2003)

The genome can be modeled as a set of strings (chromosomes) of distinguished elements called genes. Genome duplication is an important source of new gene functions and novel physiological pathways. Originally (ancestrally), a duplicated genome contains two identical copies of each chromosome, but through the genomic rearrangement mutational processes of reciprocal translocation (prefix and/or suffix exchanges between chromosomes) and substring reversals, this simple doubled structure is disrupted. At the time of observation, each of the chromosomes resulting from the accumulation of rearrangements can be decomposed into a succession of conserved segments, such that each segment appears exactly twice in the genome. We present exact algorithms for reconstructing the ancestral doubled genome in linear time, minimizing the number of rearrangement mutations required to derive the observed order of genes along the present-day chromosomes. Somewhat different techniques are required for a translocations-only model, a translocations/reversals model, both of these in the multichromosomal context (eukaryotic nuclear genomes), and a reversals-only model for single chromosome prokaryotic and organellar genomes. We apply these methods to the yeast genome, which is thought to have doubled, and to the liverwort mitochondrial genome, whose duplicate genes are unlikely to have arisen by genome doubling.
Class numbers of real cyclotomic fields of prime conductor
Authors: René Schoof
Venue: Mathematics of Computation (2003)

The class numbers hl+ of the real cyclotomic fields Q(ζl + + ζl+-1) are notoriously hard to compute. Indeed, the number hl+ is not known for a single prime l ≥ 71. In this paper we present a table of the orders of certain subgroups of the class groups of the real cyclotomic fields Q(ζl + ζl-1) for the primes l > 10,000. It is quite likely that these subgroups are in fact equal to the class groups themselves, but there is at present no hope of proving this rigorously. In the last section of the paper we argue -on the basis of the Cohen-Lenstra heuristics-that the probability that our table is actually a table of class numbers hl+, is at least 98%.
Perceptual validation experiments for evaluating the quality of wavelet-synthesized sounds
Authors: Nadine E. Miner, Timothy E. Goldsmith, Thomas P. Caudell
Venue: Presence: Teleoperators and Virtual Environments (2002)

This paper describes three psychoacoustic experiments that evaluated the perceptual quality of sounds generated from a new wavelet-based synthesis technique. The synthesis technique provides a method for modeling and synthesizing percepsually compelling sound. The experiments define a methodology for evaluating the effectiveness of any synthesized sound. An identification task and a context-based rating task evaluated the perceptual quality of individual sounds. These experiments confirmed that the wavelet technique synthesizes a wide variety of compelling sounds from a small model set. The third experiment obtained sound similarity ratings. Psychological scaling methods were applied to the similarity ratings to generate both spatial and network models of the perceptual relations among the synthesized sounds. These analysis techniques helped to refine and extend the sound models. Overall, the studies provided a framework to validate synthesized sounds for a variety of applications including virtual reality and data sonification systems.
A sequential pruning strategy for the selection of the number of states in hidden Markov models
Authors: Manuele Bicego, Vittorio Murino, Mário A. T. Figueiredo
Venue: Pattern Recognition Letters (2003)

This paper addresses the problem of the optimal selection of the structure of a hidden Markov model. A new approach is proposed, which is able to deal with drawbacks of standard general purpose methods, like those based on the Bayesian inference criterion, i.e., computational requirements, and sensitivity to initialization of the training procedures. The basic idea is to perform "decreasing" learning, starting each training session from a "nearly good" situation, derived from the result of the previous training session by pruning the "least probable" state of the model. Experiments with real and synthetic data show that the proposed approach is more accurate in finding the optimal model, is more effective in classification accuracy, while reducing the computational burden.
Distance learning
Authors: Merilyn Burke, Bruce Lubotsky Levin, Ardis Hanson
Venue: Building a virtual library (2003)

Gapen (1993) states that the concept of remote access to the contents and services of libraries and other information resources provides the user technology that brings access to the resources of multiple libraries and information services. With the evolution of a variety of methods involved in distance education, the role of academic libraries has broadened to provide resources and services to these invisible but very tangible students.This chapter begins with a brief review of the history of distance education and the impact of this technology on higher education. The chapter also explores the role of libraries and librarians in providing the variety of services, resources, and technology necessary to support this steadily growing facet of academic institutions. Finally, the chapter will present a case illustration of how one university has incorporated its virtual library as a critical element in its distance learning educational initiatives.
Hierarchy of the Control and Optimal-Control Structures
Authors: A. V. Babichev, A. G. Butkovskii
Venue: Automation and Remote Control (2003)

An axiomatic approach to determination and analysis of the control structures was proposed. Abstract mathematical structures enabling one to develop a metric approach to the general problem of optimal control and establish the optimality conditions were considered. A new structure, hierarchy of metrics, characterizing the control system in the sense of the optimal-control problem was shown to arise. The structure of the state space and its existence conditions were considered. The chosen approach enables one to obtain a new hierarchy of the basic control structures in terms of a particular system of axioms.