ppxscal/embedding_network huggingface dataset:
DIVERSE: a framework for building extensible and reconfigurable device-independent virtual environments and distributed asynchronous simulations
Authors: John Kelso, Steven G. Satterfield, Lance E. Arsenault, Peter M. Ketchan, Ronald D. Kriz
Venue: Presence: Teleoperators and Virtual Environments (2003)

We present DIVERSE, a highly modular collection of complimentary software packages designed to facilitate the creation of device-independent virtual environments and distributed asynchronous simulations. DIVERSE is free/open source software, containing both end-user programs and C++ application programming interfaces (APIs).DPF is the DIVERSE graphics interface to OpenGL Performer. A program using the DPF API can run without modification on platforms ranging from fully immersive systems such as CAVEs to generic desktop workstations.The DIVERSE toolkit (DTK) contains all the nongraphical components of DIVERSE, such as networking utilities, hardware device access, and navigational techniques. It introduces a software implementation of networks of replicated noncoherent shared memory. It also introduces a method that seamlessly extends hardware drivers into interprocess and Internet hardware services.We will describe the design of DIVERSE and present a specific example of how it is being used to aid researchers.
Generalized de Bruijn digraphs and the distribution of patterns in α-expansions
Authors: Wolfgang Steiner
Venue: Discrete Mathematics (2003)

A generalization of de Bruijn digraphs is defined for Party's α-expansions and it is shown that the characteristic polynomial of these graphs is in principle that of α. With the help of this result we prove that certain functionals of α-expansions, e.g. the number of specific digital patterns, satisfy a central limit theorem, which is an extension of a result due to Drmota (Proceedings of the International Conference held in Graz, Austria, 1998, p. 103).
Complexes of t-Colorable Graphs
Authors: Svante Linusson, John Shareshian
Venue: SIAM Journal on Discrete Mathematics (2003)

We study the simplicial complex of t-colorable graphs on n vertices. We prove this complex is homotopy equivalent to a wedge of spheres all of dimension $n(t-1)-\binom{t}{2}-1$ when t=2 and when $t\ge n-3$. We show that such a homotopy equivalence does not hold for general t and n.
Branch and Infer: a Unifying Framework for Integer and Finite Domain Constraint Programming
Authors: Alexander Bockmayr, Thomas Kasper
Venue: INFORMS Journal on Computing (1998)

We introduce branch and infer, a unifying framework for integer linear programming and finite domain constraint programming. We use this framework to compare the two approaches with respect to their modeling and solving capabilities, to introduce symbolic constraint abstractions into integer programming, and to discuss possible combinations of the two approaches.
An Assessment of Design-for-Environment Practices in Leading US Electronics Firms
Authors: Michael Lenox, Andrew King, John Ehrenfeld
Venue: Interfaces (2000)

A growing number of managers believe that addressing environmental impacts in product-design decisions has tangible advantages to firms. Yet many firms struggle to diffuse design-for-environment (DfE) practices across their product-development teams. Four leading electronics firms' attempts to adopt DfE suggest that the establishment of highly interconnected, internal information networks may be a robust diffusion strategy. Technically competent centers acting as clearinghouses of companywide information relevant to environmental design and coordinated with specialists on individual product-design teams seem to be an effective organizational structure for diffusing DfE. Internal information networks reduce the cost to designers of assessing environmental costs and benefits and thus lower the motivational barriers of product managers.Environmental design tools may be a component of successful DfE practice but do not seem to be sufficient in themselves. The complexity of environmental issues requires an approach that continually generates new information. Dense information networks allow pockets of expertise to form in response to ever-changing needs.
Characteristics of river flow in the Transylvanian Basin
Authors: V. Sorocovschi, G. Pandi
Venue: Development and application of computer techniques to environmental studies (2002)

One of the largest depression in the Romanian Carpathians, the Transylvanian Basin, occupies the central part of Romania, being a typical upland region. The river flow characteristics in the Transylvanian Basin have been pointed out as a result of data processing and interpretation activities carried out at 24 hydrometric stations. The humidity contrasts as a consequence of the territory exposure to the advection of oceanic air masses coming from the west are reflected by the distribution of the components of the hydrological balance, which has been presented in detail in the first section of the present paper. The second section focuses on the way in which the effects of the climatic demarcation influence the temporal distribution of the flow, the frequency flow rhythms, as well as on the territorial distribution of the types and subtypes of regime.
Context-based prefetch &ndash; an optimization for implementing objects on relations
Authors: Philip A. Bernstein, Shankar Pal, David Shutt
Venue: The VLDB Journal &mdash; The International Journal on Very Large Data Bases (2000)

When implementing persistent objects on a relational database, a major performance issue is prefetching data to minimize the number of round-trips to the database. This is especially hard with navigational applications, since future accesses are unpredictable. We propose the use of the context in which an object is loaded as a predictor of future accesses, where a context can be a stored collection of relationships, a query result, or a complex object. When an object O's state is loaded, similar state for other objects in O's context is prefetched. We present a design for maintaining context and for using it to guide prefetch. We give performance measurements of its implementation in Microsoft Repository, showing up to a 70% reduction in running time. We describe several variations of the optimization: selectively applying the technique based on application and database characteristics, using application-supplied performance hints, using concurrent database queries to support asynchronous prefetch, prefetching across relationship paths, and delayed prefetch to save database round-trips.
Efficient instruction encoding for automatic instruction set design of configurable ASIPs
Authors: Jong-eun Lee, Kiyoung Choi, Nikil Dutt
Venue: Proceedings of the 2002 IEEE/ACM international conference on Computer-aided design (2002)

Application-specific instructions can significantly improve the performance, energy, and code size of configurable processors. A common approach used in the design of such instructions is to convert application-specific operation patterns into new complex instructions. However, processors with a fixed instruction bitwidth cannot accommodate all the potentially interesting operation patterns, due to the limited code space afforded by the fixed instruction bitwidth. We present a novel instruction set synthesis technique that employs an efficient instruction encoding method to achieve maximal performance improvement. We build a library of complex instructions with various encoding alternatives and select the best set of complex instructions while satisfying the instruction bitwidth constraint. We formulate the problem using integer linear programming and also present an effective heuristic algorithm. Experimental results using our technique generate instruction sets that show improvements of up to 38% over the native instruction set for several realistic benchmark applications running on a typical embedded RISC processor.
Invited review: combining forecasts - twenty years later
Authors: C. W. J. Granger
Venue: Essays in econometrics: Spectral analysis, seasonality, nonlinearity, methodology, and forecasting (2001)

The combination of forecasts is a simple, pragmatic and sensible way to possibly produce better forecasts. Simple extensions of the original idea involve the use of various available "forecasts" even if some are rather inefficient. Some unsolved questions relate to combining forecasts with horizons longer than one period. More complicated extensions are associated with "encompassing" and the combination of confidence intervals or quantiles. The relevance of information sets is emphasized in both the underlying theory and the interpretation of combinations.
A physical interface for system dynamics simulation
Authors: Oren Zuckerman, Mitchel Resnick
Venue: CHI '03 extended abstracts on Human factors in computing systems (2003)

We present the System Blocks, a new physical interactive system that makes it easier for kids to explore dynamic systems. A set of computationally enhanced children blocks, made of wood and electronics, the System Blocks can assist K-12 educators to teach the complex concepts of system dynamics and causalities. System dynamics and system thinking are methods for studying the world around us. They deal with understanding how complex systems change over time, and how structure influences behavior. In this paper we will show how the System Blocks enable young children (as early as four years old) to create and interact with systems that simulate real-life dynamic behavior such as a bank account; population growth; or the delicate equilibrium of an ecosystem. The System Blocks gives young children a hands-on environment to learn about complex behavior and encourage new ways of thinking.
On the primality of n! &#x00B1; 1 and 2&#x00D7;3&#x00D7;5&#x00D7;...&#x00D7; p&#x00B1;1
Authors: Chris K. Caldwell, Yves Gallot
Venue: Mathematics of Computation (2002)

For each prime p, let p# be the product of the primes less than or equal to p. We have greatly extended the range for which the primality of n! ± 1 and p# ± 1 are known and have found two new primes of the first form (6380! + 1, 6917! - 1) and one of the second (42209# + 1). We supply heuristic estimates on the expected number of such primes and compare these estimates to the number actually found.
Course Planning at Lufthansa Technical Training: Constructing More Profitable Schedules
Authors: Knut Haase, Jorg Latteier, Andreas Schirmer
Venue: Interfaces (1999)

Lufthansa Technical Training GmbH (LTT) runs training courses for Lufthansa Technik AG and for several other international airlines. It offers about 670 types of courses of which several hundred take place each year. The course-scheduling problem LTT faces is to develop a schedule for the year that maximizes its profit while meeting complex precedence, temporal, and resource-related constraints. A good operational schedule should also meet a number of subordinate objectives. In the past, LTT did all its scheduling manually. We developed a prototype course-scheduling module, using the operational planning situation of 1996 as our major test instance. It turned out that most of the schedules generated were substantially better than the solution LTT constructed manually, both in terms of profit and computation time. We subsequently developed a fully fledged decision-support system.
Vehicle Scheduling in Public Transit and Lagrangean Pricing
Authors: Robert E. Kraut, Ronald E. Rice, Colleen Cool, Robert S. Fish, Andreas Lobel
Venue: Management Science (1998)

This paper investigates the solution of the linear programming (LP) relaxation of the multi-commodity flow formulation of the multiple-depot vehicle scheduling problems arising in public mass transit. We develop a column generation technique that makes it possible to solve the huge linear programs that come up there. The technique, which we call Lagrangean pricing, is based on two different Lagrangean relaxations. We describe in detail the basic ingredients of our approach and give computational results for large-scale test data (with up to 70 million variables) from three German public transportation companies. Because of these results, we propose Lagrangean pricing as one of the basic ingredients of an effective method to solve multiple-depot vehicle scheduling problems to proven optimality.
Are remote and non-remote workers different? exploring the impact of trust, work experience and connectivity on performance outcomes
Authors: D. Sandy Staples
Venue: Advanced topics in end user computing (2002)

Information technology (IT) is enabling the creation of virtual organizations and remote work practices. As this practice of employees working remotely from their managers and colleagues grows, so does the importance of making these remote end-users of technology effective members of organizations. This study tested a number of relationships that were suggested in the literature as being relevant in a remote work environment. Interpersonal trust of the employees in their managers was found to be strongly associated with higher self-perceptions of performance, higher job satisfaction and lower job stress. There was weak support for the impact of physical connectivity (i.e., the availability of IT) on job satisfaction, supporting the enabling role of IT. These findings were similar for both remote employees (i.e., those that worked in a different building than their managers) and nonremote employees. However, more frequent communications between the manager and employee was associated with higher levels of interpersonal trust only with the remote workers. Cognition-based trust was also found to be more important than affect-based trust in a remote work environment, suggesting that managers of remote employees should focus on activities that demonstrate competence, responsibility and professionalism.
In the zone: the need for flexible roles
Authors: Phillip Armour
Venue: Communications of the ACM (2003)

Blurring the lines of distinction between team roles is often necessary to adapt to a changing environment.
Knowledge-based extrapolation of cases: a possibilistic approach
Authors: Eyke Hüllermeier, Didier Dubois, Henri Prade
Venue: Technologies for constructing intelligent systems: Tasks (2002)

The paper presents a formal framework of instance-based prediction in which the generalization beyond experience is founded on the concepts of similarity and possibility. The underlying extrapolation principle is formalized by means of possibility rules, a special type of fuzzy rules. Thus, instance-based prediction can be realized as fuzzy set-based approximate reasoning. The basic model is extended by means of fuzzy set-based (linguistic) modeling techniques, including the discounting of untypical cases and the flexible handling and adequate adaptation of different similarity relations. This extension provides a convenient way of incorporating domain-specific (expert) knowledge. Our approach thus allows for combining knowledge and data in a flexible way and favors a view of instance-based reasoning according to which the user interacts closely with the system.
Not All Events Are Attended Equally: Toward a Middle-Range Theory of Industry Attention to External Events
Authors: Andrew J. Hoffman, William Ocasio
Venue: Organization Science (2001)

This paper builds on prior theory and research on attention and identity to examine whether and how industries publicly attend to external events. Events are critical triggers of institutional transformation and industry evolution. However, they must first become the focus of public attention to have this effect. We draw on a paired case comparison of media coverage of eight nonroutine events affecting the natural environment and the U.S. chemical industry. We employ both deductive and inductive analysis to develop a model and hypotheses to explain two research questions. First, what determines the initial public attention to an event? Second, when and why do certain events attain high and sustained levels of industry attention? A key inference is that whether an event receives industry-level attention depends on either outsiders holding the industry accountable for the event, or insiders' internal concerns with the industry image. We further infer that an event can be transformed into a critical issue for an industry, warranting sustained attention, if there is contestation with outsiders over the accountability for the event and its enactment, and internal contradictions and challenges to the industry's identity.
Stochastic dynamics for structural engineering problems: a review
Authors: G. Muscolino
Venue: Civil and structural engineering computing: 2001 (2001)

In this review some of the most recent developments of importance within the field of stochastic dynamics in structural engineering are discussed. Particularly emphasis is put on the improvement of the calculation of non-Gaussian probability density function. In this area methods for the evaluation of this density for nonlinear systems are treated in detail.
On the common zeros of Bessel functions
Authors: Eugenia N. Petropoulou, Panayiotis D. Siafarikas, Ioannis D. Stabolas
Venue: Journal of Computational and Applied Mathematics (2003)

Using a functional analytic method we give some results concerning common zeros of the ordinary Bessel functions Jv(z) of first kind, with respect to v and fixed z. A lower bound for the common zero z of the Bessel functions Jv(z), Jµ(z), where v, µ are known, is also given.
Decision technologies for new bid pricing processes in distribution industries
Authors: P. Bussey, N. Cassaigne
Venue: Systems engineering for business process change: new directions (2002)

The vast majority of business-to-business purchases are performed through contract bidding. For any business involved in bidding for contracts a significant problem exists: How to increase their number of successful bids while maintaining or increasing profit margins upon those bids? Chapter 11 examines the current processes used by businesses for setting bid prices and highlights their failures. By re-engineering the current approaches a new generic bid pricing process has been created that provides a well-structured, formal method of pricing bids that can be adapted to many industries. A set of software tools providing decision support for the new process has also been developed. An adaptation of the process and its application within the handling and distribution industry through a successful case study are also described.
Delegating Pricing Decisions
Authors: Pradeep Bhardwaj
Venue: Marketing Science (2001)

An outstanding problem in marketing is why some firms in a competitive market delegate pricing decisions to agents and other firms do not. This paper analyzes the impact of competition on the delegation decision and, in turn, the impact of delegation on prices and incentives. The theory builds on the simplest framework of competition in two dimensions: prices and (sales agents') effort. Specifically, we are interested in answering the following questions: (1) Does competition affect the price-delegation decision and, if yes, why? (2) How do prices vary under price-delegation and no-price-delegation scenarios? (3) Do the incentives to the sales representatives vary under the delegation and no-delegation scenarios?To address these issues, we build a game-theoretic model that consists of two firms selling through their sales representatives. These representatives are company employees. Sales are a function of prices and selling efforts. The risk-neutral firms decide whether or not to delegate the pricing decision to risk-averse sales representatives. The wages to the sales representatives consist of salary plus a commission on gross margins. The commission on gross margins can be adjusted, either through communicated marginal cost of production, which we call ''virtual'' marginal cost, or directly. The firm and the sales representative are assumed to have the same information about the market, that is, there is no information asymmetry.With competition in two dimensions, the strategic nature of decision variableprice depends on the relative intensity of competition. With unobservable contracts and risk-averse sales representatives, firms delegate the pricing decision when price competition is intense. Part of the uncertainty in demand is absorbed by the firm by keeping ''virtual'' marginal cost greater than the marginal cost of production. The competing firm infers this through the risk aversion of the sales representatives. Under price delegation the sales representatives' wages are higher, and they set a price that is higher than what the firms would have set themselves. This leads to softening of price competition that is to the advantage of both firms. When the effort competition is dominant, however, the firms prefer to make the pricing decision themselves, because this reduces the intensity of effort competition among agents.A single-instrument commission structure in which the firms adjust the ''virtual'' marginal cost is compared to a two-instrument commission structure in which the firms can adjust the commission rate, as well the ''virtual'' marginal cost. Under no price delegation, the two incentive schemes are the same. However, under price delegation the risk premium with the two-instrument scheme is lower. However, the prices and efforts are higher with the single-instrument scheme. When price competition is intense, the increase in risk premium with the single instrument scheme is more than compensated for by the increase in profits. This is the benefit of softening price competition through higher prices.
Asymptotic Behavior of an Allocation Policy for Revenue Management
Authors: William L. Cooper
Venue: Operations Research (2002)

Revenue management has become an important tool in the airline, hotel, and rental car industries. We describe asymptotic properties of revenue management policies derived from the solution of a deterministic optimization problem. Our primary results state that, within a stochastic and dynamic framework, solutions arising out of a single well-known linear program can be used to generate allocation policies for which the normalized revenue converges in distribution to a constant upper bound on the optimal value. We also show similar asymptotic results for expected revenues. In addition, we describe counterintuitive behavior that can occur when allocations are updated during the booking process (updating allocations can lead to lower expected revenue). These results add to the understanding of allocation policies and help to make concrete the statement that simple policies from easy-to-solve formulations can be relatively effective, even when analyzed in the more realistic stochastic and dynamic framework.