Validating plans with continuous effects

A critical element in the use of PDDL2.1, the modelling language developed for the International Planning Competition series, has been the common understanding of the semantics of the language. The fact that this has been implemented in plan validation software was vital to the progress of the competition. However, the validation of plans using actions with continuous effects presents new challenges (that precede the challenges presented by planning with those effects). In this paper we review the need for continuous effects, their semantics and the problems that arise in validation of plans that include them. We report our progress in implementing the semantics in an extended version of the plan validation software

Driving departmental change through evaluation: Some outcomes and problems

This paper identifies the ways in which a three‐year technology‐based learning and teaching project has addressed the issue of catalysing departmental change. In order to promote change at this level, it is necessary to relate the accepted learning and teaching parameters of specific disciplines to meaningful evaluation data of student and staff perceptions, in an attempt to broaden the understanding of academic staff. Thus, a number of factors become important to the process of change including: supportive role models within departments; forging feasible departmental implementation plans; utilizing support staff with a technical and pedagogical awareness; and fully involving students in curriculum development and design. Inhibitors to change also need to be noted, for instance: time‐management; resource and training allocation; and a lack of managerial support. However, the creation of a supportive structure which highlights good practice is fundamental in gaining uptake of materials and in changing perceptions. An acceptance of staff development needs in the light of the objectives of both the student and the curriculum is required This holistic approach provides a suitable environment for the symbiosis between learning and teaching to develop

Plan validation and mixed-initiative planning in space operations

Bringing artificial intelligence planning and scheduling applications into the real world is a hard task that is receiving more attention every day by researchers and practitioners from many fields. In many cases, it requires the integration of several underlying techniques like planning, scheduling, constraint satisfaction, mixed-initiative planning and scheduling, temporal reasoning, knowledge representation, formal models and languages, and technological issues. Most papers included in this book are clear examples on how to integrate several of these techniques. Furthermore, the book also covers many interesting approaches in application areas ranging from industrial job shop to electronic tourism, environmental problems, virtual teaching or space missions. This book also provides powerful techniques that allow to build fully deployable applications to solve real problems and an updated review of many of the most interesting areas of application of these technologies, showing how powerful these technologies are to overcome the expresiveness and efficiency problems of real world problems

Studies in the surface chemistry of boundary lubrication

Imperial Users onl

Supply Chain Management in the Hospitality Industry: A research agenda

Supply Chain Management is at the heart of competitive advantage for any organisation. Without Supply Chains, the Hospitality Industry would quickly grind to a halt. There would be no fruit or vegetables in our restaurants, no beer or wine in our bars and no beds or toilets in our hotels. There would be no recycling of glass or the disposal of food products. There would be no customers. Given the importance of Supply Chains to the Hospitality Industry it is perhaps surprising that so little is published about Supply Chains and how Supply Chains can be managed. The aim of this working paper is to define SCM and establish an agenda for undertaking research into this important but neglected topic

Estimating the Impact of California Tribal Gaming on Demand for Casino Gaming in Nevada

Since 1990, the California tribal casino industry has grown from a very small and insignificant industry to one with annual gross gaming revenues of about $7.5 billion per annum by 2009. Over this same period, Nevada\u27s gaming revenues grew from approximately$5.0 billion in 1990 to $10.4 billion in 2009, having declined from a peak of$12.8 billion in 2007. Much of the recent decline in Nevada and especially Las Vegas can be attributed to the severity of the economic recession of 2007-2009. However, the major Northern Nevada destination resorts of Reno and South Lake Tahoe had experienced substantial slowdowns or contraction of their gaming industries since the advent of California tribal gaming in the early 1990s, as measured in a number of ways, including number of gaming devices, employment, and gross gaming revenues adjusted for inflation. Las Vegas, on the other hand, had experienced substantial real growth over this same period, until the Great Recession of 2007-2009, at which point it experienced a dramatic reversal of fortune. This analysis estimates demand relationships for gaming activity in the major tourism markets in Northern and Southern Nevada, by specifying a number of variables that relate to the demand for gambling in these markets as well as noting monthly seasonal shifts. It also examines the competitive links between the expansion of California tribal gaming and the Nevada casino industry\u27s economic performance. Regression analysis is utilized to establish the relationship between the growth and expansion of tribal casinos in California and the expansion or contraction of gaming in Nevada\u27s major regions of Reno, Lake Tahoe, and the Las Vegas Strip

Activating Boxmind: an evaluation of a web‐based video lecture with synchronized activities

The aim of this study was to evaluate the use of synchronous computer‐mediated communication activities in a video e‐lecture. Previous research has reported that learning is facilitated when communication activities are added to a video lecture. Twelve postgraduate students participated in the study and they viewed a video e‐lecture on the perspective‐taking theory of communication. The lecture consisted of a video image of the lecturer, an audio track, slides, the transcript and a number of communication activities. They were given a pre‐test a week before the lecture and a post‐test a week after. They were also asked to rate the helpfulness of various aspects of the lecture. Students’ post‐test scores were statistically significantly higher than their pre‐test scores. They found the audio track, transcript, slides and activities helpful. The most helpful aspects were the communication activities. The implications of these findings are discussed

Managing the transition toward self-sustaining alternative fuel vehicle markets : policy analysis using a dynamic behavioral spatial model

Thesis (S.M.)--Massachusetts Institute of Technology, Engineering Systems Division, Technology and Policy Program, 2007.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (p. 68-75).Designing public policy or industry strategy to bolster the transition to alternative fuel vehicles (AFVs) is a formidable challenge as demonstrated by historical failed attempts. The transition to new fuels occurs within a dynamically complex system with many distributed actors, long time delays, several important feedback relationships, and multiple tipping points. A broad-boundary, behavioral, dynamic model with explicit spatial structure was previously developed to represent the most important AFV transition barriers. Using California as an illustrative testing region, the model simulates the spatial diffusion of entrant vehicle/fuel technology pairs individually or in competition with other entrants. In this work, the integrated model is carefully parameterized for various specific alternative vehicle technologies. Structural and parametric sensitivity analyses are used to build understanding of system behavior and to identify policy leverage points or the need for further model calibration.(cont.) The qualitative impacts of policies are tested individually and then in multi-policy combinations to find synergies. Under plausible assumptions and strong policies, AFVs can achieve successful diffusion but this process requires long time periods. Findings indicate some commonly suggested policies may provide little leverage and be very costly. The analysis reveals the importance of designing policy cognizant of the system structure underlying its dynamic behavior. Several examples demonstrate how policy leverage varies with context such as key attributes of the alternative vehicle technology. Broadly, coordinated portfolios of policy instruments should be designed to simultaneously develop consumer familiarity, well distributed fueling infrastructure, and manufacturer knowledge at similar rates and over long enough duration to surpass thresholds in these complementary assets before alternative fuel and vehicle markets become self-sustaining. Further, policy should dynamically adapt to observed conditions to lessen the transition constraints dominant at the time. Policy and strategy makers must recognize from the outset that incentives must be stable over long durations for AFV transitions to succeed.by Derek R. Supple.S.M

Very low inheritance in cosmogenic surface exposure ages of glacial deposits: A field experiment from two Norwegian glacier forelands

Terrestrial cosmogenic nuclide dating has been widely used to estimate the surface exposure age of bedrock and boulder surfaces associated with deglaciation and Holocene glacier variations, but the effect of inherited age has been rarely directly addressed. In this study, small clasts, embedded in flute surfaces on two cirque glacier forelands in Jotunheimen, southern Norway and deposited within the last ~60 years, were used to test whether such clasts have the modern surface exposure age expected in the absence of inheritance. Two different approaches were taken involving dating of (1) a single clast of cobble size from the proglacial area of Austanbotnbreen, and (2) 75 clasts mostly of pebble size from the proglacial area of Storbreen crushed and treated as a single sample. 10Be surface exposure ages were 99 ± 98 and 368 ± 90 years, respectively, with 95% confidence (±2σ). It is concluded that (1) these small glaciers have eroded and deposited rock fragments with a cosmogenic zero or near-zero concentration, (2) the likelihood of inherited cosmogenic nuclide concentrations in similar rock fragments deposited by larger warm-based glaciers and ice sheets should be small, and (3) combining a large number of small rock particles into one sample rather than using single large clasts of boulder size may provide a viable alternative to the commonly perceived need for five or more independent estimates of exposure age per site