ppxscal/embedding_network huggingface dataset:
Communication and Trust in Global Virtual Teams
Authors: Sirkka L. Jarvenpaa, Dorothy E. Leidner
Venue: Organization Science (1999)

This paper explores the challenges of creating and maintaining trust in a global virtual team whose members transcend time, space, and culture. The challenges are highlighted by integrating recent literature on work teams, computer-mediated communication groups, cross-cultural communication, and interpersonal and organizational trust. To explore these challenges empirically, we report on a series of descriptive case studies on global virtual teams whose members were separated by location and culture, were challenged by a common collaborative project, and for whom the only economically and practically viable communication medium was asynchronous and synchronous computer-mediated communication. The results suggest that global virtual teams may experience a form of "swift" trust, but such trust appears to be very fragile and temporal. The study raises a number of issues to be explored and debated by future research. Pragmatically, the study describes communication behaviors that might facilitate trust in global virtual teams.
Clustering Spatial Data in the Presence of Obstacles: a Density-Based Approach
Authors: Osmar R. Zaïane, Chi-Hoon Lee
Venue: Proceedings of the 2002 International Symposium on Database Engineering & Applications (2002)

Clustering spatial data is a well-known problem that has been extensively studied. Grouping similar data in large 2-dimensional spaces to find hidden patterns or meaningful sub-groups has many applications such as satellite imagery, geographic information systems, medical image analysis, marketing, computer visions, etc. Although many methods have been proposed in the literature, very few have considered physical obstacles that may have significant consequences on the effectiveness of the clustering. Taking into account these constraints during the clustering process is costly and the modeling of the constraints is paramount forgood performance. In this paper, we investigate the problem of clustering in the presence of constraints such as physical obstacles and introduce a new approach to model these constraints using polygons. We also propose a strategy to prune the search space and reduce the number of polygons to test during clustering. We devise a density-based clusteringalgorithm, DBCluC, which takes advantage of our constraint modeling to efficiently cluster data objects while considering all physical constraints. The algorithm can detect clusters of arbitrary shape and is insensitive to noise, the input order, and the difficulty of constraints. Its average running complexity is O(NlogN) where N is the number of data points.
Exploring the distribution of online healthcare information
Authors: Suresh K. Bhavnani, Renju T. Jacob, Jennifer Nardine, Frederick A. Peck
Venue: CHI '03 extended abstracts on Human factors in computing systems (2003)

Motivated by the importance of retrieving comprehensive healthcare information, we analyzed how information about 12 concepts related to a widely available healthcare topic is distributed across 145 high-quality webpages. The analysis reveals that the distribution of the concepts follows a power law where a few pages contain many concepts, while the majority contains less than half the concepts. The analysis also reveals the existence of general, specialized, and sparse pages, in addition to the large number of pages that users must visit before they have access to all the concepts. These results provide insights into expert search procedures, and motivate the design of future search systems that guide users in the retrieval of comprehensive information.
High Multiplicity in Earliness-Tardiness Scheduling
Authors: John J. Clifford, Marc E. Posner
Venue: Operations Research (2000)

When a production shop has a large number of identical parts, the parts are often recorded by a part description and quantity. This differs from the type of description used by standard scheduling problems, which assume that all parts or jobs are unique. In high-multiplicity scheduling problems, identical jobs are encoded in an efficient format similar to that of the production shop. The input describes one of the jobs and the number of such identical jobs. We consider single-machine, high-multiplicity problems with earliness and tardiness weights. We investigate three categories of weights: unit, common, and job-specific. For the unit and common weights problems, a polynomial time algorithm is developed. The algorithm takes advantage of identical jobs and finds solutions faster than by standard methods.We provide a new method for creating a lower bound for the standard encoding of the job-specific weights problem, which is NP-complete. We disaggregate each job into identical sub jobs with unit processing times. Then, using high-multiplicity encoding for this disaggregated problem, we create a lower bound on the optimal objective function value of the original problem in polynomial time. Heuristic solutions are generated using a randomized rounding technique on the lower bound solution. These results are used in a branch and-bound solution method. Analytical and computational results are presented. Our combination of disaggregation and high-multiplicity encoding provides a new method for creating lower bounds on the objective functions of NP-complete problems.
Aspect-oriented software components
Authors: Anders I. Mørch
Venue: Adaptive evolutionary information systems (2003)

This chapter presents a novel approach for conceptualising and organising computer applications for the purpose of simplifying end-user tailorability and evolutionary application development. The chapter combines ideas from software systems, end-user programming, Gestalt psychology, and everyday tools. An application unit is the basic unit of tailorability. It is defined as a visual component extended with aspects. Aspects provide user-oriented entry points into an application unit at different levels of abstraction. Tools and techniques for locating, viewing and tailoring application unit aspects are presented, and the results of a user study are reported. A goal of writing this chapter has been to present a comprehensive view of some basic technology for user participation in evolutionary application development.
Energy-Aware Wireless Networking with Directional Antennas: The Case of Session-Based Broadcasting and Multicasting
Authors: Jeffrey E. Wieselthier, Gam D. Nguyen, Anthony Ephremides
Venue: IEEE Transactions on Mobile Computing (2002)

We consider ad hoc wireless networks that use directional antennas and have limited energy resources. To explore quantitatively the advantage offered by the use of directional antennas over the case of omnidirectional antennas, we consider the case of connection-oriented multicast traffic. Building upon our prior work on multicasting algorithms, we introduce two protocols that exploit the use of directional antennas and evaluate their performance. We observe significant improvement with respect to the omnidirectional case, in terms of both energy efficiency and network lifetime. Additionally, we show that further substantial increase in the network's lifetime can be achieved by incorporating a simple measure of a node's residual energy into the node's cost function.
Just Modeling Through: a Rough Guide to Modeling
Authors: Richard E. White, John N. Pearson, Jeffrey R. Wilson, Michael Pidd
Venue: Interfaces (1999)

Skill in modeling is one of the keys to success in OR/MS practice. This has been recognized for many years, but we often give it only lip service. Models are used in many ways in OR/MS practice. A few simple principles of modeling may be useful. The six principles discussed here cover simplicity versus complexity; model development as a gradual, almost piecemeal process; dividing larger models into smaller components; using analogies; proper uses of data; and finally the way in which the modeling process can seem chaotic. Others may wish to comment on these principles and add their own.
Evaluation of Installation Stock Based (R, Q)-Policies Fortwo-Level Inventory Systems with Poisson Demands
Authors: Gonzalo Cortazar, Eduardo S. Schwartz, Marcelo Salinas, James E. Smith, Sven Axsater
Venue: Operations Research (1998)

We consider a two-level inventory system with one warehouse and N retailers. Leadtimes (transportation times) are constant, and the retailers face different Poisson demand processes. All facilities apply continuous review installation stock (R, Q)-policies with different reorder points and batch quantities. We show how to evaluate holding and shortage costs exactly in case of two retailers. In case of more than two retailers we use the same methodology as an approximation. When evaluating costs at a certain retailer, the other retailers are then aggregated into a single retailer.
Modelling and analysis of ground vibration problems: a review
Authors: D. Le Houédec
Venue: Civil and structural engineering computing: 2001 (2001)

The transmission of vibrations over the surface of the ground constitutes the main field of this review. The general problem of determining the response of a soil medium under the action of vertical harmonic sources is investigated theoretically. Two kinds of ground are considered : the first one is modeled as an elastic half-space and the second one as an elastic layer overlaying a rigid foundation (bedrock). The effect of the loading speed is particularly studied for the dynamic response. A lot of methods are briefly presented : semi-analytical methods, finite element methods (classical and special), coupled finite and infinite element methods,..., with varied applications.
Production of Collective Action in Alliance-Based Interorganizational Communication and Information Systems
Authors: Peter R. Monge, Janet Fulk, Michael E. Kalman, Andrew J. Flanagin, Claire Parnassa, Suzanne Rumsey
Venue: Organization Science (1998)

This article presents a public goods-based theory that describes the process of producing multifirm, alliance-based, interorganizational communication and information public goods. These goods offer participants in alliances collective benefits that are (a) nonexcludable, in that they are available to all alliance partners whether or not they have contributed, and (b) jointly supplied, in that partners' uses of the good are noncompeting. Two generic types of goods produced are connectivity, the ability of partners to directly communicate with each other through the information and communication system, and communality, the availability of a commonly accessible pool of information to alliance partners. Four types of alliances that can produce these goods are identified: (a) precompetitive, (b) competitive, (c) joint value creation, and (d) value chain. The article examines a variety of factors that influence the production of alliancebased connective and communal goods. Twenty-three integrated propositions are presented. The article concludes with an example of the application of the theoretical model to research on connectivity and communality provided through an alliancebased interorganizational communication and information system linking more than 50 alliance partners.
Adapting multimedia for diverse student learning styles
Authors: Glenn D. Blank, Soma Roy, Shreeram Sahasrabudhe, William M. Pottenger, G. Drew Kessler
Venue: Journal of Computing Sciences in Colleges (2003)

Multimedia can accommodate diverse learning styles. By giving students different ways to learn material, we hope to attract more novices, especially women and minorities, to computer science. We designed a user interface that is independent of both book metaphors and familiar web browsers. It supplies sound and animation for sensory learners, while letting verbal learners disable sound or switch altogether to a JUST THE FACTS mode. Interactive materials include learner-controlled simulations of algorithms, links to programs that students can try immediately after learning related concepts and before exercises that make sure the learner has studied the programs, constructive exercises in which students build programs or models by dragging pieces into place, and inquiry-based exercises in which students learn by doing research, using the web.
Optimal and Hierarchical Controls in Dynamic Stochastic Manufacturing Systems: A Survey
Authors: S. P. Sethi, H. Yan, H. Zhang, Q. Zhang
Venue: Manufacturing Service Operations Management (2002)

Most manufacturing systems are large and complex and operate in an uncertain environment. One approach to managing such systems is that of hierarchical decomposition. This paper reviews the research devoted to proving that a hierarchy based on the frequencies of occurrence of different types of events in the systems results in decisions that are asymptotically optimal as the rates of some events become large compared to those of others. The paper also reviews the research on stochastic optimal control problems associated with manufacturing systems, their dynamic programming equations, existence of solutions of these equations, and verification theorems of optimality for the systems. Manufacturing systems that are addressed include single-machine systems, dynamic flowshops, and dynamic jobshops producing multiple products. These systems may also incorporate random production capacity and demands, and decisions such as production rates, capacity expansion, and promotional campaigns. Related computational results and areas of applications are also presented. A more detailed survey is available at .
Beyond numbers
Authors: Ubiquity staff
Venue: Ubiquity (2002)

Martha Amram on the current economics of technology investment.
A positive spatial advection scheme on triangular meshes for tracer transport
Authors: P. Wilders
Venue: Scientific computing and applications (2001)

Modelling tracer transport (leading to a single linear advection-diffusion equation) for realistic data provides a challenging task with respect to the robustness of the underlying numerical procedures. In this paper we contribute at this point by formulating a positive spatial advection scheme for triangular meshes. The proof of positivity is presented in detail, using an elementary classification. It is shown that with a careful reconstruction procedure and a moderate demand towards the grid a positive advection scheme is obtained. Next, a brief discussion is given on how we implement this scheme in combination with an implicit time stepping procedure. As a numerical example we discuss tracer transport in a strongly heterogeneous porous medium.
Cellular phone manuals: users' benefit from spatial maps
Authors: Susanne Bay
Venue: CHI '03 extended abstracts on Human factors in computing systems (2003)

Manuals of technical devices are often not very helpful to the user. This study investigates the influence of spatial instructions versus conventional linear step-by-step manuals on inexperienced users' performance handling cellular phones. Results show a significant interaction between user age and manual. Middle aged users profit more from the spatial information given in the manual that contains the phone's menu tree than from the step-by-step instruction, whereas subjects older than 50 show no improvement. It is concluded that manufacturers should consider the inclusion of spatial information on the cellular phones' menu structure in their manuals, as the majority of users would benefit.
Efficient Uses of FPGAs for Implementations of DES and Its Experimental Linear Cryptanalysis
Authors: Gaël Rouvroy, Francois-Xavier Standaert, Jean-Jacques Quisquater, Jean-Didier Legat
Venue: IEEE Transactions on Computers (2003)

In its basic version, linear cryptanalysis is a known-plaintext attack that uses a linear relation between input-bits, output-bits, and key-bits of an encryption algorithm that holds with a certain probability. If enough plaintext-ciphertext pairs are provided, this approximation can be used to assign probabilities to the possible keys and to locate the most probable one. In 1993, Matsui applied it to DES, becoming the best known attack against DES. In 2000, Knudsen proposed three chosen-plaintext linear attacks, the third one becoming the best chosen-plaintext attack. This paper presents two original FPGA implementations of a DES encryption/decryption core that work at data rates up to 21.3 Gbps (333 MHz). We believe that our implementations are the fastest ones known nowadays. In our design, the plaintext, the key, and the mode (encryption/decrytion) can be changed with no dead cycles. Based on one of our fast DES implementations, we present an FPGA implementation of the known-plaintext linear cryptanalysis of DES. The resulting design is deployed on eight FPGAs and allows us to find 12 + 1 key bits in about 2.3 hours. As a comparison, the fastest software implementation known so far (in 2000) used the idle time of 18 Intel Pentium III MMX and broke a DES key in 4.32 days. Our fast linear cryptanalysis implementation made the performing of practical tests possible, allowing a comparison with Matsui's theoretical estimations.
Abstract interpretation of mobile ambients
Authors: Flemming Nielson, René Rydhof Hansen, Hanne Riis Nielson
Venue: Science of Computer Programming (2003)

We show how abstract interpretation can be expressed in a constraint-based formalism that is becoming increasingly popular for the analysis of functional and object-oriented languages. This is illustrated by developing analyses for the ambient calculus.The first step of the development constructs an analysis for counting occurrences of processes inside other processes; we show that the analysis is semantically correct and that the set of acceptable solutions constitutes a Moore family. The second step considers a previously developed control flow analysis and shows how to induce it from the counting analysis; we show that its properties can be derived from those of the counting analysis using general results about abstract interpretation for constraint-based analyses.
Low-Dimensional Linear Programming with Violations
Authors: Timothy M. Chan
Venue: Proceedings of the 43rd Symposium on Foundations of Computer Science (2002)

Two decades ago, Megiddo and Dyer showed that linear programming in 2 and 3 dimensions (and subsequently, any constant number of dimensions) can be solved in lineartime. In this paper, we consider linear programming with at most k violations: finding a point inside all but at most k of n given halfspaces. We give a simple algorithm in 2-d that runs in 0((n + k^2 )\log n) expected time; this is faster than earlier algorithms by Everett, Robert, and van Kreveld (1993) and Matou¿ek (1994) and is probably near-optimal for all k \ll {n \mathord{\left/ {\vphantom {n 2}} \right. \kern-\nulldelimiterspace} 2}. A (theoretical) extension of our algorithm in 3-d runs in near 0(n + k^{{{11} \mathord{\left/ {\vphantom {{11} 4}} \right. \kern-\nulldelimiterspace} 4}} n^{{1 \mathord{\left/ {\vphantom {1 4}} \right. \kern-\nulldelimiterspace} 4}}) expected time. Interestingly, the idea is based on concave-chain decompositions (or covers) of the( \leqslant k)-level, previously used in proving combinatorial k-level bounds.Applications in the plane include improved algorithms for finding a line that misclassifies the fewest among a set of bichromatic points, and finding the smallest circle enclosing all but k points. We also discuss related problems of finding local minima in levels.
A distributed program synthesizer
Authors: Vahur Kotkas
Venue: Acta Cybernetica (2002)

This paper describes an architecture of a distributed synthesizer for automated program construction. The objective of the synthesizer is to realize the ideas of Structural Synthesis of Programs in a computer network. The synthesizer handles structural specifications stored into Java classes as meta-interfaces and works on a network using CORBA technology.
Aggregation Error Bounds for a Class of Location Models
Authors: R. L. Francis, T. J. Lowe, Arie Tamir
Venue: Operations Research (2000)

Many location models involve distances and demand points in their objective function. In urban contexts, there can be millions of demand points. This leads to demand point aggregation, which produces error. We identify a general model structure that includes most such location models, and present a means of obtaining error bounds for all models with this structure. The error bounds suggest how to do the demand point aggregation so as to keep the error small.
Constructions of representations of o(2n + 1, C) that imply Molev and Reiner-Stanton lattices are strongly Sperner
Authors: Robert G. Donnelly, Scott J. Lewis, Robert Pervine
Venue: Discrete Mathematics (2003)

Two infinite families of distributive lattices parameterized by positive integers n and k are considered. The first family of lattices, here denoted LRSB(k,2n), was introduced by Reiner and Stanton (J. Algebraic Combin. 7 (1998) 91) as the distributive lattices Good(k,2n) of certain partitions. There, Reiner and Stanton showed that these lattices are rank symmetric and rank unimodal and conjectured that they are strongly Sperner. The second family of lattices introduced here is denoted LMolB(k, 2n) because of its connection to certain representation constructions of the odd orthogonal Lie algebras obtained by Molev (J. Phys. A 33 (2000) 4143). For fixed n and k, the two lattices have the same rank generating function, but the lattices are isomorphic as posets if and only if k = 1. In this paper, the lattices LRSB(k,2n) and LMolB(k,2n) are used to produce two different constructions of the irreducible representation of the odd orthogonal Lie algebra o(2n + 1, C) isomorphic to the largest irreducible component in the kth symmetric power of the defining representation of o(2n + 1, C). Constructions of the analogous infinite family of irreducible representations of G2 are obtained as a special case. These constructions use the elements of the lattices to index bases for the representing spaces, and explicit formulas for the matrix entries of the representing matrices for certain Lie algebra generators are given. These constructions together with a result of Proctor imply that both lattices are rank symmetric, rank unimodal, and strongly Sperner.
Towards a "Universal dictionary" for multi-language information retrieval applications
Authors: J. Michael Schultz, Mark Y. Liberman
Venue: Topic detection and tracking: event-based information organization (2002)

Multilingual information retrieval tasks such as Topic Tracking have yielded high-quality results simply using word-by-word translation approaches. However, the construction of translation dictionaries for new languages is expensive and time-consuming. We show that an appropriate metric for term selection in a monolingual English corpus allows us to define a fairly small list, containing about ten thousand inflected forms or about 7500 lemmas, which works essentially as well (for a particular monolingual document classification evaluation) as an unlimited vocabulary of more than 300,000 word forms does. We suggest that such a list can be taken to form the English axis of a sort of "universal dictionary" for document classification tasks, providing a much more efficient path to the addition of new languages.