2Planning for Contingencies: A Decision-based Approach

A fundamental assumption made by classical AI planners is that there is no uncertainty in the world: the planner has full knowledge of the conditions under which the plan will be executed and the outcome of every action is fully predictable. These planners cannot therefore construct contingency plans, i.e., plans in which different actions are performed in different circumstances. In this paper we discuss some issues that arise in the representation and construction of contingency plans and describe Cassandra, a partial-order contingency planner. Cassandra uses explicit decision-steps that enable the agent executing the plan to decide which plan branch to follow. The decision-steps in a plan result in subgoals to acquire knowledge, which are planned for in the same way as any other subgoals. Cassandra thus distinguishes the process of gathering information from the process of making decisions. The explicit representation of decisions in Cassandra allows a coherent approach to the problems of contingent planning, and provides a solid base for extensions such as the use of different decision-making procedures.Comment: See http://www.jair.org/ for any accompanying file

Escribiendo a Casandra: personajes dramáticos en la narrativa contemporánea

Christa Wolf’s Cassandra is the landmark for refigurations of the Cassandra myth in the contemporary novel. Yet close to its date of publication, Ursule Molinaro (1979), Christine Brooke-Rose (1984) and Hilary Bailey (1993) published their own novelistic reworkings of the Cassandra myth. The presence of the Cassandra myth in the British novel is in contrast with the fruitful reworkings of the Trojan princess in poetry and drama. From the nineteenth century onwards, refigurations of Cassandra in prose writings in English range from the feminist essay to the novel of customs and the fin-de-siècle New Women utopias. Works such as Florence Nightingale’s Cassandra, for example, show how the words of Priam’s daughter can be adapted to social vindications and develop into an obscure discourse which results in Broke-Rose’s postmodernist deconstruction. This chapter seeks to analyze Cassandra’s prophetic language in the three novels in contrast with other refigurations of the myth in English which reveal the cultural processes behind the construction of the narratives

Baby M and the Cassandra Problem

Part I of this essay outlines the facts of the Baby M case and traces the reasoning the New Jersey Supreme Court used to justify the legal conclusions that it reached. Part II then identifies the three common analytical techniques or modes of argument on which the state supreme court relied in conducting its analysis and suggests that each is itself too dependent upon unprincipled policy preferences to have excluded such preferences from the decisionmaking process. Finally, Part III suggests that no matter how strong an argument one might offer to demonstrate the systemic vulnerability of principle to preference, the demonstration could never be convincing. Such arguments are paradoxically self-defeating

Towards the timely detection of toxicants

We address the problem of enhancing the sensitivity of biosensors to the influence of toxicants, with an entropy method of analysis, denoted as CASSANDRA, recently invented for the specific purpose of studying non-stationary time series. We study the specific case where the toxicant is tetrodotoxin. This is a very poisonous substance that yields an abrupt drop of the rate of spike production at t approximatively 170 minutes when the concentration of toxicant is 4 nanomoles. The CASSANDRA algorithm reveals the influence of toxicants thirty minutes prior to the drop in rate at a concentration of toxicant equal to 2 nanomoles. We argue that the success of this method of analysis rests on the adoption of a new perspective of complexity, interpreted as a condition intermediate between the dynamic and the thermodynamic state.Comment: 6 pages and 3 figures. Accepted for publication in the special issue of Chaos Solitons and Fractal dedicated to the conference "Non-stationary Time Series: A Theoretical, Computational and Practical Challenge", Center for Nonlinear Science at University of North Texas, from October 13 to October 19, 2002, Denton, TX (USA

In search of the 1619 African arrivals

Accepted manuscrip

A decade of GRB follow-up by BOOTES in Spain (2003-2013)

This article covers ten years of GRB follow-ups by the Spanish BOOTES stations: 71 follow-ups providing 23 detections. Follow-ups by BOOTES-1B from 2005 to 2008 were given in the previous article, and are here reviewed, updated, and include additional detection data points as the former article merely stated their existence. The all-sky cameras CASSANDRA have not yet detected any GRB optical afterglows, but limits are reported where available

Different Methods of Embodied Cognition in Pedagogy and its Effectiveness in Student Learning

The Mathematical Ideas Analysis hypothesizes that abstract mathematical reasoning is unconsciously organized and integrated with sensory-motor experience. Basic research testing movement, language, and perception during math problem solving supports this hypothesis. Applied research primarily measures students’ performance on math tests after they engage in analogous sensory-motor tasks, but findings show mixed results. Sensory-motor tasks are dependent on several moderators (e.g., instructional guidance, developmental stage) known to help students learn, and studies vary in how each moderator is implemented. There is little research on the effectiveness of sensory-motor tasks without these moderators. This study compares different approaches to working with an interactive application designed to emulate how people intrinsically solve algebraic equations. A total of 130 participants (84 females, 54 males) were drawn from a pool of Introductory Psychology students attending San Jose State University. Participants were placed in three different learning environments, and their performance was measured by comparing improvement between a pre-test and a post-test. We found no difference between participants who worked alone with the application, were instructed by the experimenter while using the application, or who instructed the experimenter on how to solve equations using the application. Further research is needed to examine how and whether analogous sensory-motor interfaces are a useful learning tool, and if so, what circumstances are ideal for sensory-motor interfaces to be used

Juvenile substance use and effects of substance use disorder on incarceration and grade retention in a sample referred for court clinic mental health evaluation

A significant amount of adolescents are involved in the drug court system. Within a few of the systems are mental health clinics providing more specific services to youth introduced into the courts. At the Rhode Island Family Court, juveniles are referred for full mental health evaluations in the court mental health clinic. They are then referred for other services depending on the outcome of the evaluation. The purpose of this study is to provide a descriptive analysis of the drug use of these youth referred to the mental health clinic. Because little is known about the about the affects of a substance use disorder diagnosis on incarceration and grade repetition, an analysis was done to determine if any associations were present. After accounting for mental health diagnosis and demographic variables, an association between substance use disorder and incarceration within 3 months of the mental health evaluation was found. There was no significant association between a substance use disorder diagnosis and grade repetition in school