Lifeworld Analysis

We argue that the analysis of agent/environment interactions should be extended to include the conventions and invariants maintained by agents throughout their activity. We refer to this thicker notion of environment as a lifeworld and present a partial set of formal tools for describing structures of lifeworlds and the ways in which they computationally simplify activity. As one specific example, we apply the tools to the analysis of the Toast system and show how versions of the system with very different control structures in fact implement a common control structure together with different conventions for encoding task state in the positions or states of objects in the environment.Comment: See http://www.jair.org/ for any accompanying file

Bridging the gap between digital libraries and e-learning

Digital Libraries (DL) are offering access to a vast amount of digital content, relevant to practically all domains of human knowledge, which makes it suitable to enhance teaching and learning. Based on a systematic literature review, this article provides an overview and a gap analysis of educational use of DLs.The research work presented in this paper is partially supported by the FP7 Grant 316087 AComIn ”Advanced Computing for Innovation”, funded by the European Commission in the FP7 Capacity Programme in 2012-2016.peer-reviewe

How to Win the Nobel Prize?

One Nobel laureate reviews another's account of "The Beginner's Guide to Winning the Nobel Prize. A Life in Science.

Theory of Spin Polarization Phenomena in Atomic and Molecular Photoeffects

A compact invariant expression for the angular distribution of photoelectrons formed as a result of photoionization of axisymmetrically polarized atoms and molecules, including optically active molecules, is derived from the general symmetry considerations and using a recently developed bipolar harmonic reduction technique. In the angular distribution of photoelectrons, as well as in the total photoionization cross section, the dependence on all the geometric parameters is separated completely. The polarization of ionizing radiation can be arbitrary, with the partial polarization being specified by the Stokes parameters. The expression for the angular distribution of photoelectrons escaping from an atomic–molecular system oriented in the first order also determines the structure of the expression for the photoionization cross section of an unpolarized system with allowance for the spin polarization of a photoelectron or a photoion with the spin 1/2. The roles played by circular dichroism, chirality, etc., in the process of photoionization of oriented and aligned systems are analyzed in detail

Practical Resource Allocation Algorithms for QoS in OFDMA-based Wireless Systems

In this work we propose an efficient resource allocation algorithm for OFDMA based wireless systems supporting heterogeneous traffic. The proposed algorithm provides proportionally fairness to data users and short term rate guarantees to real-time users. Based on the QoS requirements, buffer occupancy and channel conditions, we propose a scheme for rate requirement determination for delay constrained sessions. Then we formulate and solve the proportional fair rate allocation problem subject to those rate requirements and power/bandwidth constraints. Simulations results show that the proposed algorithm provides significant improvement with respect to the benchmark algorithm.Comment: To be presented at 2nd IEEE International Broadband Wireless Access Workshop. Las Vegas, Nevada USA Jan 12 200

The Assq Chip and Its Progeny

The Assq Chip lives on the memory bus of the Scheme-81 chip of Sussman et al and serves as a utility for the computation of a number of functions concerned with the maintenance of linear tables and lists. Motivated by a desire to apply the design methodology implicit in Scheme-81, it was designed in about two months, has a very simple architecture and layout, and is primarily machine-generated. The chip and the design process are described and evaluated in the context of a proposal to construct a Scheme-to-silicon compiler that automates the design methodology used in the Assq Chip.MIT Artificial Intelligence Laborator

The Structures of Everyday Life

This note descends from a talk I gave at the AI Lab's Revolving Seminar series in November 1984. I offer it as an informal introduction to some work I've been doing over the last year on common sense reasoning. Four themes wander in and out. 1) Computation provides an observation vocabulary for introspection. With a little work, you can learn to exhume your models of everyday activities. This method can provide empirical grounding for computational theories of the central systems of mind. 2) The central systems of mind arise in each of us as a rational response to the impediments to living posed by the laws of computation. One of these laws is that all search problems (theorem proving for example) are intractable. Another is that no one model of anything is good enough for all tasks. Reasoning from these laws can provide theoretical grounding for computational theories of the central systems of mind. 3) Mental models tend to form mathematical lattices under the relation variously called subsumption or generalization. Your mind puts a lot of effort into maintaining this lattice because it has so many important properties. One of these is that the more abstract models provide a normalized decomposition of world-situations that greatly constrains the search for useful analogies. 4) I have been using these ideas in building a computational theory of routines, the frequency repeated and phenomenologically automatic rituals of which most of daily life is made. I describe this theory briefly.MIT Artificial Intelligence Laborator

What to Read: A Biased Guide to AI Literacy for the Beginner

Acknowledgements. It was Ken Forbus' idea, and he, Howie Shrobe, Dan Weld, and John Batali read various drafts. Dan Huttenlocher and Tom Knight helped with the speech recognition section. The science fiction section was prepared with the aid of my SF/AI editorial board, consisting of Carl Feynman and David Wallace, and of the ArpaNet SF-Lovers community. Even so, all responsibility rests with me.This note tries to provide a quick guide to AI literacy for the beginning AI hacker and for the experienced AI hacker or two whose scholarship isn't what it should be. most will recognize it as the same old list of classic papers, give or take a few that I feel to be under- or over-rated. It is not guaranteed to be thorough or balanced or anything like that.MIT Artificial Intelligence Laborator

Partnering For Success: The Principals\u27 Role In Beginning Teacher-Mentor-Principal Relationships

This small-scale qualitative study examined the perceptions of elementary principals, mentors and beginning teachers regarding the principal\u27s role in promoting beginning teacher professional growth within comprehensive induction programs. This role may not be clear to principals, mentors, beginning teachers or induction program leaders. In recent years, the call for principal instructional leadership is in the forefront of the literature with increasing emphasis placed on academic standards and accountability. This emphasis is shifting the focus of principal instructional leadership from teaching to student learning. Mentors and principals are working together with beginning teachers to accelerate professional growth and impact student achievement. This three-way relationship creates a triad of educators invested in supporting beginning teachers and accelerating their professional growth. Qualitative study methods were used, including interviews, district, and state program level document review. For the purposes of this study, participants included four elementary triads working in different building sites within the same Midwestern district. Five broad themes emerged from the analysis process: (a) healthy school cultures and trusting relationships influenced beginning teacher professional growth; (b) beginning teachers relied on their mentors to prepare them to be successful in the eyes of their principals; (c) the mentoring and induction program structure influenced beginning teacher\u27s experience; (d) supervision and evaluation promoted beginning teacher growth within the structured mentoring and induction program; and (e) all participants benefitted from the mentoring experience when communication occurred within the triad. It is essential for induction leaders at local, regional and national levels to recognize the importance of individual principal\u27s beliefs, dispositions, and actions in setting the tone for the work of the mentoring and induction program at their school sites. The absence of systematic and consistent principal interaction limits opportunities for consistent feedback and the development of trusting relationships and professional growth for all teachers

Writing and Representation

This paper collects several notes I've written over the last year in an attempt to work through my dissatisfactions with the ideas about representation I was taught in school. Among these ideas are the notion of a 'world model'; the notion of representations having 'content' independent of the identity, location, attitudes, or activities of any agent; and the notion that a representation is the sort of thing you might implement with datastructures and pointers. Here I begin developing an alternative view of representation whose prototype is a set of instructions written in English on a sheet of paper you're holding in your hand while pursuing some ordinarily complicated concrete project in the everyday world. Figuring out what the markings on this paper are talking about is a fresh problem in every next setting, and solving this problem takes work. Several detailed stories about representation use in everyday activities—such as assembling a sofa from a kit, being taught to fold origami cranes, following stories across pages of a newspaper, filling a photocopier with toner, and keeping count when running laps—illustrate this view. Finally, I address the seeming tension between necessity of interpreting one's representations in every next setting and the idea that everyday life is fundamentally routine.MIT Artificial Intelligence Laborator