Energetic particle influence on the Earth's atmosphere

This manuscript gives an up-to-date and comprehensive overview of the effects of energetic particle precipitation (EPP) onto the whole atmosphere, from the lower thermosphere/mesosphere through the stratosphere and troposphere, to the surface. The paper summarizes the different sources and energies of particles, principally galactic cosmic rays (GCRs), solar energetic particles (SEPs) and energetic electron precipitation (EEP). All the proposed mechanisms by which EPP can affect the atmosphere are discussed, including chemical changes in the upper atmosphere and lower thermosphere, chemistry-dynamics feedbacks, the global electric circuit and cloud formation. The role of energetic particles in Earth’s atmosphere is a multi-disciplinary problem that requires expertise from a range of scientific backgrounds. To assist with this synergy, summary tables are provided, which are intended to evaluate the level of current knowledge of the effects of energetic particles on processes in the entire atmosphere

Why are Algebra word problems difficult? Using tutorial log files and the power law of learning to select the best fitting cognitive model

Abstract. Some researchers have argued that algebra word problems are difficult for students because they have difficulty in comprehending English. Others have argued that because algebra is a generalization of arithmetic, and generalization is hard, it’s the use of variables, per se, that cause difficulty for students. Heffernan and Koedinger [9] [10] presented evidence against both of these hypotheses. In this paper we present how to use tutorial log files from an intelligent tutoring system to try to contribute to answering such questions. We take advantage of the Power Law of Learning, which predicts that error rates should fit a power function, to try to find the best fitting mathematical model that predicts whether a student will get a question correct. We decompose the question of “Why are Algebra Word Problems Difficult? ” into two pieces. First, is there evidence for the existence of this articulation skill that Heffernan and Koedinger argued for? Secondly, is there evidence for the existence of the skill of “composed articulation ” as the best way to model the “composition effect” that Heffernan and Koedinger discovered?

Operational Semantics for Agents by Iterated Refinement

In this paper we evaluate transition systems as a tool for providing a rule-based specification of the operational aspects of autonomous agents. By our technique, different aspects of an agent can be analyzed and designed in a loosely coupled way, enabling the possibility of studying their properties in isolation. We take as a use case the ParADE framework for building intelligent agents, which leverages a FIPA-like ACL semantics to support semantic interoperability. Our grey-boxing technique is exploited to provide a specification where aspects related to the ACL, the adopted ontology, the agent social role, and the other agent internal details are described separately, in an incremental way