Showing papers in "CTIT technical reports series in 2000"

Policy-Based Network Management with SNMP

Abstract: This paper presents a way of managing configuration of network elements via a set of high-level rules or business policies rather than managing device by device. First, there is a need for abstraction of the capabilities of the individual devices, thus switching the control to network level. The benefit is that we can specify and issue unique management rules (or commands) that can be applied to a cross-section of network devices. Second, a way to manipulate (create, install, monitor, modify, revoke) the policy rules across the network is needed. The IETF SNMPConf (Configuration Management with SNMP [3]) working group explores how the Internet Standard Management Framework SNMP can be used for policy-based configuration management. The material presented in this paper is heavily based on the work of this group.

Generating topologically correct schematic maps

Abstract: This paper studies the creation of schematic maps from traditional vector based carto graphic information An algorithm is proposed to modify positions of lines in the original input map with the goal of producing as output a schematic map that meets certain geomet ric and aesthetic criteria Special emphasis is placed here on preserving topological structure of features during this transformation The known existing methods for preserving topol ogy during map transformation generally involve computing several constrained Delaunay triangulations Mol Gol JBW Rua The algorithm proposed here computes a transformation which preserves topological relations among linear features using simple ge ometric operations and tests

Managing uncertainty in call centers using Poisson mixtures.

Abstract: We model a call centre as a queueing model with Poisson arrivals having an unknown varying arrival rate. We show how to compute prediction intervals for the arrival rate, and use the Erlang formula for the waiting time to compute the consequences for the occupancy level of the call centre. We compare it to the current practice of using a point estimate of the arrival rate (assumed constant) as forecast. Copyright © 2001 John Wiley & Sons, Ltd.

A Customer Service Management Architecture for the Internet

Abstract: Managing services on the Internet is becoming more and more complex and time consuming for service providers since services are increasing both in number and complexity. Also the number of users per service is going up. A solution to this problem is to allow the service users themselves to partly manage the services they are using. This is called Customer Service Management, and it will both increase the perceived value of the services to the users as well as lower the operational costs of service management for the service provider. This paper presents an architecture for Customer Service Management in the Internet.

Grassland bird use of Conservation Reserve Program Fields in the Great Plains

Abstract: An enormous area in the Great Plains is currently enrolled in the Conservation Reserve Program (CRP): 19.5 million acres (nearly 8 million ha) in Montana, North Dakota, South Dakota, Wyoming, Nebraska, Colorado, Kansas, Oklahoma, and Texas. Th is change in land use from cropland to grassland since 1985 has markedly infl uenced grassland bird populations. Many, but certainly not all, grassland species do well in CRP fi elds. Th e responses by birds to the program diff er not only by species but also by region, year, the vegetation composition in a fi eld, and whether or not a fi eld has been hayed or grazed. Th e large scale and extent of the program has allowed researchers to address important conservation questions, such as the eff ect of the size of habitat patch and the infl uence of landscape features on bird use. However, most studies on nongame bird use of CRP in or near the Great Plains have been short-lived; 83% lasted only 1–3 years. Further, attention to the topic seems to have waned in recent years; the number of active studies peaked in the early 1990s and dramatically declined after 1995. Because breeding-bird use of CRP fi elds varies dramatically in response both to vegetational succession and to climatic variation, long-term studies are important. What was learned about CRP in its early stages may no longer be applicable. Finally, although the CRP provisions of the Farm Bill have been benefi cial to many grassland birds, it is critical that gains in grassland habitat produced by the program not be off set by losses of native prairie. Introduction Grasslands are among the nation’s most threatened ecosystems (Samson and Knopf 1994, Noss et al. 1995). Th eir declines have been dramatic, with losses of native grasslands reaching 99.9% for tallgrass prairie in many states, and 70–80% for mixed-grass prairies. Grassland communities and the wildlife that depend on them have suff ered from these declines, as well as from 1 Present address: c/o Department of Fisheries, Wildlife, and Conservation Biology, University of Minnesota, St. Paul, MN 55108, USA; Douglas_H_Johnson@usgs.gov.

Semantics as a foundation for psychology: a case study of Wason's selection task

Abstract: We review the various explanations that have been offered toaccount for subjects' behaviour in Wason's famous selection task. Weargue that one element that is lacking is a good understanding ofsubjects' semantics for the key expressions involved, and anunderstanding of how this semantics is affected by the demands the taskputs upon the subject's cognitive system. We make novel proposals inthese terms for explaining the major content effects of deonticmaterials. Throughout we illustrate with excerpts from tutorialdialogues which motivate the kinds of analysis proposed. Our long termgoal is an integration of the various insights about conditionalreasoning on offer from different cognitive science methodologies. Thepurpose of this paper is to try to draw the attention of logicians andsemanticists to this area, since we believe that empirical investigationof the cognitive processes involved could benefit from semanticanalyses.

Fuzzy Context-Free Languages. Part 1: Generalized Fuzzy Context-Free Grammars

Abstract: Motivated by aspects of robustness in parsing a context-free language, we study generalized fuzzy context-free grammars. These fuzzy context-free K-grammars provide a general framework to describe correctly as well as erroneously derived sentences by a single generating mechanism. They model the situation of making a finite choice out of an infinity of possible grammatical errors during each context-free derivation step. Formally, a fuzzy context-free K-grammar is a fuzzy context-free grammar with a countable rather than a finite number of rules satisfying the following condition: for each symbol α, the set containing all right-hand sides of rules with left-hand side equal to α forms a fuzzy language that belongs to a given family K of fuzzy languages. We investigate the generating power of fuzzy context-free K-grammars, and we show that under minor assumptions on the parameter K, the family of languages generated by fuzzy context-free K-grammars possesses closure properties very similar to those of the family of ordinary context-free languages.

Target selection based on fuzzy clustering : a volume prototype approach to CoIL Challenge 2000

Abstract: A fuzzy clustering based solution to the CoIL Challenge 2000 is described. The challenge consists of correctly determining which customers have caravans in a real world customer data base, and of describing the characteristics of their profile. The solution provided uses fuzzy clustering to granulate different features and determines a score for each cluster. A version of the fuzzy c-means algorithm extended with volume prototypes and similarity based cluster merging is applied for the clustering. A score for each customer is determined from their membership to different clusters and used to select potential caravan owners. Feature selection is also performed using the scores of different clusters. This provides a transparent model that can be used for describing the profile of the potential customers.

Reverse Charging in the Internet, an Architecture for a new Accounting Scheme for Internet Traffic

Abstract: Charging for traffic in the Internet is gaining importance, due to the introduction of different Quality of Service classes and the increasing access speeds of end-users. Current charging schemes are limited since they do not allow Internet Service Providers (ISPs) to charge customers of other ISPs for data that is transferred to these customers. This paper presents an architecture for reverse charging in the Internet, that does allow such payments to be made. Reverse charging enables new business scenarios for traffic flow in the Internet.