ppxscal/embedding_network huggingface dataset:
Ecological disturbance maintains and promotes biodiversity in an artificial plant ecology
Authors: Ben Clark, Seth Bullock
Venue: Proceedings of the seventh international conference on simulation of adaptive behavior on From animals to animats (2002)

A model of plant growth, competition and reproduction in three dimensions was constructed using L-systems to simulate plant growth, ray tracing to simulate sunlight and shading, and a steady-state genetic algorithm to simulate evolution by natural selection. Simulated plant growth conformed to expected trade-offs between, for instance, growing up and growing out. Simulated cohorts exhibited conventional population-level phenomena such as obeying the self-thinning law. Competition between species was simulated under various disturbance regimes. Undisturbed, a K-selected type of plant species dominated at equilibrium. However, under certain disturbance regimes, diverse life-history strategies were able to coexist at equilibrium, and even speciate.
Introduction to topic detection and tracking
Authors: James Allan
Venue: Topic detection and tracking: event-based information organization (2002)

The Topic Detection and Tracking (TDT) research program has been running for five years, starting with a pilot study and including yearly open and competitive evaluations since then. In this chapter we define the basic concepts of TDT and provide historical context for the concepts. In describing the various TDT evaluation tasks and workshops, we provide an overview of the technical approaches that have been used and that have succeeded.
Global localization and topological map-learning for robot navigation
Authors: David Filliat, Jean-Arcady Meyer
Venue: Proceedings of the seventh international conference on simulation of adaptive behavior on From animals to animats (2002)

This paper describes a navigation system implemented on a real mobile robot. Using simple sonar and visual sensors, it makes possible the autonomous construction of a dense topological map representing the environment. At any time during the mapping process, this system is able to globally localize the robot, i.e. to estimate the robot's position even if the robot is passively moved from one place to another within the mapped area. This is achieved using algorithms inspired by Hidden Markov Models adapted to the on-line building of the map. Advantages and drawbacks of the system are discussed, along with its potential implications for the understanding of biological navigation systems.
Design principles
Authors: Per Brinch Hansen
Venue: The origin of concurrent programming: from semaphores to remote procedure calls (2002)

This is the opening chapter of the author's book on concurrent programming. The essay describes the fundamental principles of programming which guided the design and implementation of the programming language Concurrent Pascal and the model operating systems written in that language.
Multi-object segregation: ant-like brood sorting using minimalist robots
Authors: Matt Wilson, Chris Melhuish
Venue: Proceedings of the seventh international conference on simulation of adaptive behavior on From animals to animats (2002)

This study shows that a task as complicated as multiobject annular segregation can be accomplished by robots using a 'minimalist' solution employing a simple adaptive mechanism and minimal hardware. The success of the mechanism, which employs a combined leaky integrator, is demonstrated both in simulation and using real robots.
Assessing the Value of Information Sharing in a Promotional Retail Environment
Authors: Ananth. V. Iyer, Jianming Ye
Venue: Manufacturing Service Operations Management (2000)

We focus on a logistics system where inventory is held at three levels: the customers, the retail store, and the warehouse. Retail customer segments are heterogeneous and differ in their reservation prices for product as well as their holding costs. They purchase product from a retail store managed by a retailer. The retailer chooses a retail pricing scheme to maximize his expected profit given a model of customer temporal response to retail pricing. This retailer is supplied product from a warehouse managed by a manufacturer.The manufacturer is responsible for maintaining inventory level at the warehouse and providing 100% service level for retailer orders. The manufacturer uses all available information to generate an inventory policy that maximizes expected profit subject to the service-level requirement. We evaluate the manufacturer's optimal expected profit under two possible schemes: (1) no information regarding the timing of retail promotion plans, and (2) full information regarding the timing of retail promotion plans.We show: (1) as the predictability of the sales impact of a promotion decreases, it may be optimal for the retailer to eliminate retail promotions; (2) increased stockpiling tendency of customers increases retailer profits and decreases manufacturer profits; and (3) retail-promotion information sharing can make retail promotions change from being less profitable than no promotions to being more profitable than no promotions for the manufacturer. We show the impact of fitting the model to a grocery store data set that provided data regarding retail sales (and associated prices) of canned tomato soup over two years. We also explore managerial insights suggested by the model.
Cataloging and metadata issues for electronic resources
Authors: Susan Jane Heron, Charles L. Gordon
Venue: Building a virtual library (2003)

The environment in which cataloging principles and standards operate has changed dramatically. The development of automated systems for the creation and processing of bibliographic data, the growth of large-scale shared cataloging programs, and emerging technologies have created new opportunities to provide access to national and international academic library collections. However, economic pressures have also prompted libraries to try to simplify the cataloging process, using "minimal level" cataloging records in order to keep pace with the continued growth of publishing.Cataloging librarians have identified two significant needs: 1) to adapt existing [cataloging] codes and practices to accommodate change resulting from new forms of electronic publishing and the advent of networked access to information resources, and 2) to respond more effectively to an increasingly broad range of user expectations and needs. München (1998) wonders how catalogers will guarantee the quality and relevance of bibliographic access within the exploding world of online materials. If so, what kind of bibliographic records will be required to meet the different uses and user needs? Finally, how should these bibliographic data be organized and structured for intellectual and physical access to the documents?This chapter will provide an overview of current cataloging principles, issues in handling evolving formats, and challenges for academic catalogs. It will include a brief examination of a model created by a large multi-campus urban university in determining best practice in the creation of records for shared, online academic environments. Finally, the chapter will look at the development of alternative frameworks for describing online resources.
Teaching XML
Authors: Ed Gellenbeck, Sherry Yang
Venue: Journal of Computing Sciences in Colleges (2002)

XML has proven itself as a versatile technology, and is currently being utilized on almost every platform, and in every area of software development. This tutorial will give an introduction to XML and related technologies such as XSLT, DTDs and DOM. After completing this hands-on tutorial, you should have the basic concepts and resources to explore the possibility of integrating XML in your curriculum.
Airline Crew Recovery
Authors: Ladislav Lettovský, Ellis L. Johnson, George L. Nemhauser
Venue: Transportation Science (2000)

An airline schedule rarely operates as planned. It is often disrupted by maintenance problems or severe weather conditions. In a typical day, several flights may be delayed or canceled, and aircraft and crews may miss the rest of their assigned flights. Airline coordinators have to find a minimal cost reassignment of aircraft and crews that satisfies all required safety rules, has little impact on passengers, and minimizes operational difficulties for the airline. The size of the entire schedule and the real-time nature of the problem rule out a full-scale optimization. It is necessary to reduce the complexity and the size of the problem before an optimization approach can be applied. In this paper, we focus on the problem of airline crew recovery. A new solution framework is developed, implemented, and tested. It provides, in almost real time, a recovery plan for reassigning crews to restore a disrupted crew schedule. Preprocessing techniques are applied to extract a subset of the schedule for rescheduling. A fast crew-pairing generator is built that enumerates feasible continuations of partially flown crew trips. Several branching strategies are presented that allow fast generation of integer solutions. We disturb the current schedule as little as possible, exploiting the fact that the planned schedule is optimal. The proposed framework has been implemented using tree-based data structures for efficient storage and data access. Computational results using a schedule from a major air carrier are presented.
Improving projected successive overrelaxation method for linear complementarity problems
Authors: M. D. Koulisianis, T. S. Papatheodorou
Venue: Applied Numerical Mathematics (2003)

Projected Successive OverRelaxation (PSOR), an important method for solving Linear Complementarity Problems (LCPs), can be improved considerably if one takes into account the underlying physical properties of the problem involved. We show this for LCPs arising in the context of Moving Boundary Problems and in the case of the American Options Valuation Problem. For such problems, a time stepping procedure is necessary in which one has to solve a sequence of discrete LCPs, one per each time step. In this case, a moving (unknown) boundary separates two domains over which different solution properties hold. Taking advantage of this separation leads to an implementation of PSOR for problems of smaller dimension. This, in turn, leads to a new iterative scheme, which is up to 50% faster compared to plain PSOR.
A comprehensive calibration and registration procedure for the Visual Haptic Workbench
Authors: Milan Ikits, Charles D. Hansen, Christopher R. Johnson
Venue: Proceedings of the workshop on Virtual environments 2003 (2003)

We present a simple yet efficient calibration and registration procedure for improving the overall static display accuracy of the Visual Haptic Workbench. The procedure is used for precisely colocating the visual and haptic workspaces of the system and is divided into three stages. First, we calibrate and register the PHANToM to the display surface of the workbench. Second, we calibrate the tracking system by attaching a rigid extension between the tracker sensor and the PHANToM stylus. Third, we interactively find the remaining unknown display parameters including eye and hotspot offsets as well as a local reference frame. Initial evaluation of the approach indicates that it is possible to improve static display accuracy by at least an order of magnitude for this system.
Visualizing spatial distribution data sets
Authors: Alison Luo, David Kao, Alex Pang
Venue: Proceedings of the symposium on Data visualisation 2003 (2003)

In this paper, we define distributions as a new data type and address the challenges of visualizing spatial distribution data sets. Numerous visualization techniques exist today for dealing with scalar data. That is, there is a scalar value at each spatial location, which may also be changing over time. Likewise, techniques exist for dealing with vector, tensor and multivariate data sets. However, there is currently no systematic way of dealing with distribution data where there is a collection of values for the same variable at every location and time. Distribution data is increasingly becoming more common as computers and sensor technologies continue to improve. They have also been used in a number of fields ranging from agriculture, engineering design and manufacturing to weather forecasting. Rather than developing specialized visualization techniques for dealing with distribution data, the approach presented in this paper is to find a systematic way of extending existing visualization methods to handle this new data type. For example, we would like to be able to generate isosurfaces of 3D scalar distribution data sets, or generate streamlines of vector distribution data sets. In order to accomplish this goal, we propose the use of a set of mathematically and procedurally defined operators that allow us to work directly on distributions. Color images can also be found in www.cse.ucsc.edu/research/avis/operator.html.
User Mobility Pattern Scheme for Location Update and Paging in Wireless Systems
Authors: Erdal Cayirci, Ian F. Akyildiz
Venue: IEEE Transactions on Mobile Computing (2002)

The user mobility pattern (UMP) scheme is introduced for location update and paging in wireless systems where mobile terminals (MTs) maintain their history data in a database called user mobility history (UMH). During a location update, a UMP is derived from UMH and registered to the network. Unless the MT detects that it has moved out of the registered UMP, it does not perform any other location update. On the other hand, cells are paged selectively according to the cell entry times in the registered UMP upon a call arrival for the MT. The related data structures and the protocols for the UMP scheme are presented in the paper. The experimental results show that the UMP scheme outperforms the time-based and movement-based location update schemes as well as the blanket, selective, and velocity paging schemes.
Integrating distributed channel allocation and adaptive handoff management for QoS-sensitive cellular networks
Authors: Guohong Cao
Venue: Wireless Networks (2003)

Next generation high-speed cellular networks are expected to support multimedia applications, which require QoS provisions. Since frequency spectrum is the most expensive resource in wireless networks, it is a challenge to support QoS using limited frequency spectrum. In the literature, two orthogonal approaches are used to address the bandwidth utilization issue and the QoS provision issue; that is, channel allocation schemes have been proposed to improve bandwidth efficiency, whereas handoff management schemes, based on bandwidth reservation, have been proposed to guarantee a low connection dropping rate. However, little effort has been taken to address both issues together. In this paper, we integrate distributed channel allocation and adaptive handoff management to provide QoS guarantees and efficiently utilize the bandwidth. First, we present a complete distributed distributed channel allocation algorithm and propose techniques to reduce its message complexity and intra-handoff overhead. Second, we integrate the proposed distributed channel allocation algorithm with an adaptive handoff management scheme to provide QoS guarantees and efficiently utilize the bandwidth. Detailed simulation experiments are carried out to evaluate the proposed methodology. Compared to previous schemes, our scheme can significantly reduce the message complexity and intra-handoff overhead. Moreover, the proposed scheme can improve the bandwidth utilization while providing QoS guarantees.
Improved Constructive Multistart Strategies for the Quadratic Assignment Problem Using Adaptive Memory
Authors: Charles Fleurent, Fred Glover
Venue: INFORMS Journal on Computing (1999)

Multistart constructive approaches operate by applying a local search procedure to start from different initial solutions produced by a repeated (variable) constructive process. The classical Random Restart procedure and the more recent GRASP procedure are prominent examples of such approaches. Adaptive memor y strategies that are the heart of tabu search methods give a foundation for alternative, enhanced, multistart approaches. We demonstrate this by showing that a simple implementation of adaptive memory search principles, even when restricted to the constructive phases, can provide more effective multistart methods. Computational experiments for the quadratic assignment problem disclose that these methods improve significantly over previous multistart methods that do not incorporate such memory based strategies.
Incorporating Fuel Constraints and Electricity Spot Prices into the Stochastic Unit Commitment Problem
Authors: Samer Takriti, Benedikt Krasenbrink, Lilian S.-Y. Wu
Venue: Operations Research (2000)

The electric power industry is going through deregulation. As a result, the load on the generating units of a utility is becoming increasingly unpredictable. Furthermore, electric utilities may need to buy power or sell their production to a power pool that serves as a spot market for electricity. These trading activities expose utilities to volatile electricity prices. In this paper, we present a stochastic model for the unit commitment that incorporates power trading into the picture. Our model also accounts for fuel constraints and prices that may vary with electricity prices and demand. The resulting model is a mixed-integer program that is solved using Lagrangian relaxation and Bender's decomposition. Using this solution approach, we solve problems with 729 demand scenarios on a single processor to within 0.1% of the optimal solution in less than 10 minutes. Our numerical results indicate that significant savings can be achieved when the spot market is entered into the problem and when stochastic policy is adopted instead of a deterministic one.
Ubiquitous computing: by the people, for the people
Authors: Ali Ndiwalana, C. M. Chewar, Jacob Somervell, D. Scott McCrickard
Venue: CHI '03 extended abstracts on Human factors in computing systems (2003)

One of the challenges in building and evaluating ubiquitous computing systems emanates from the fact that they generally have been built to showcase technological innovation without considering how to foretell whether and how people will eventually accept them in their lives. In this study, participants are introduced to the notion of ubiquitous computing via a scenario-centric presentation including basic everyday objects imbued with some computational power to convey information. Through a detailed survey, participants provide feedback relating to their impressions, rating the performance of each interface on a number of metrics and making comparisons between the ubiquitous and desktop interfaces. We inspire them to think of new ways to use existing ubiquitous interfaces to support their current and possible information needs, as well as better interfaces that can convey this information.
Processor Allocation in the Mesh Multiprocessors Using the Leapfrog Method
Authors: Fan Wu, Ching-Chi Hsu, Li-Ping Chou
Venue: IEEE Transactions on Parallel and Distributed Systems (2003)

The mesh-connected multiprocessor has become popular for its simple and regular structure. In this paper, a new data structure, theR{\hbox{-}}{\rm{array}} , is proposed to represent the mesh at first. The element in theR{\hbox{-}}{\rm{array}}stores the statistical information about the occupied conditions of the mesh. The statistical information of theR{\hbox{-}}{\rm{array}}can direct the allocation process to jump to the processors that can serve as a base of a free submesh. Based on a simple and reasonable assumption, we develop a stochastic process to analyze the behaviors of the proposed scheme. The proposed scheme is the first one whose probabilities of locating free submeshes under different workloads are precisely computed. These results can be applied to each full-recognition scheme. In addition, the execution costs of the proposed scheme can also be accurately calculated. Finally, the simulations are performed. Compared with a lot of the previous schemes, the simulations show that the proposed schemes are faster than most of them.
Fault tolerant computing in computer design
Authors: Mohamad R. Neilforoshan
Venue: Journal of Computing Sciences in Colleges (2003)

This paper is presented as an attempt to cover the basic practices and methodologies involved in the area of contemporary fault tolerant computing in a computer design course. Most computer design courses cover design of various components of a computer system and integration of these components to build a system. Unfortunately, fault tolerance is not typically covered in a computer design course.We have identified four steps for our method. First, we are identifying the relative effectiveness of the different approaches in fault tolerant. Second, we are discussing various architectures used in the implementation of fault tolerance. Third, we are providing the performance overview of various architectures used. Fourth, we are covering the trade offs involved with the selection of fault tolerance versus system performance.
A unified mechanism for information systems definition in action
Authors: Frank Stowell, Donna Champion
Venue: Systems engineering for business process change: new directions (2002)

The complex and dynamic environment in which information system development (ISD) is undertaken for today's business and organisational clients has lead to a focus on Rapid Application Development and evolutionary prototyping. However, such approaches focus only on specifying the requirements for the technological support and often fail to appreciate the actual problems faced by those involved within the situation of focus. An interpretivist approach to ISD places the emphasis on first creating a shared appreciation of the problems faced by those involved in the situation and on reaching an accommodation concerning purposeful action that may be undertaken with the hope of bringing improvement. From this appreciation of a desirable and feasible intervention, the information technology (IT) needed to support this action can be specified, or changes to an existing legacy computing system, identified. The aim of the UMISD project (a Unified Mechanism for Information Systems Definition) is to develop practical interpretivist approaches to ISD, by developing modelling methods that enable the design process to be "Client-Led", as far as is possible, rather than directed toward fulfilling the requirements imposed by engineering techniques. By applying "systems" ideas and Conversation Modelling we suggest an approach to information systems design that moves from the clients" description of the agreed intervention, to the specification for the technical provision. The ideas described here have been applied in a 'Field Study' within a UK national banking organisation. An example from practice is given, and the initial ideas are critically evaluated.
An axiomatic approach to digital topology
Authors: Eladio Domínguez, Angel R. Francés
Venue: Digital and image geometry: advanced lectures (2001)

In a series of papers the authors have developed an approach to Digital Topology, which is based on a multilevel architecture. One of the foundations of this approach is an axiomatic definition of the notion of digital space. In this paper we relate this approach with several other approaches to Digital Topology appeared in literature through a deep analysis of the axioms involved in the definition of digital space.