45 research outputs found
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
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
Virtual Inclusion
Several recent knowledge-representation schemes have used virtual copies for storage efficiency. Virtual copes are confusing. In the course of trying to understand, implement, and use Jon Doyle's SDL virtual copy mechanism, we encountered difficulties that led us to define an extension of virtual copies we call virtual inclusion. Virtual inclusion has interesting similarities to the environment structures maintained by a program in a block-structured language. It eliminates the clumsy typed part mechanism of SDL, and handles properly a proposed test of sophisticated virtual copy schemes.MIT Artificial Intelligence Laborator
Új európai kutatások az információs társadalomról
A szerzĹ‘ kĂsĂ©rletet tett arra, hogy egy, a legĂşjabb eurĂłpai kutatásokat felölelĹ‘, jegyzetekkel is ellátott bibliográfiát állĂtson össze. A rövid könyvismertetĹ‘k elĹ‘tt az eurĂłpai Ă©s az amerikai informáciĂłs társadalommal kapcsolatos kutatások ellentmondásainak Ă©s eredmĂ©nyeinek rövid összefoglalása olvashatĂł. A kritikai igĂ©nyű Ărás rávilágĂt az eltĂ©rĹ‘ kutatási mĂłdszerek hiányosságaira, illetve szembeállĂtja az amerikaiak Ă©s az eurĂłpaiak mĂłdszertanát, hozzáállását Ă©s eredmĂ©nyessĂ©gĂ©t az informáciĂłs társadalommal kapcsolatos kutatásokban
Az arcunk nem vonalkód: érvek a nyilvános helyeken elhelyezett automatikus arcfelismerő berendezések használata ellen
Philip E. Agre a világon egyre terjedĹ‘ arcfelismerĹ‘ rendszerek ĂĽzemeltetĂ©se ellen száll sĂkra, tĂ©telesen cáfolva a tĂ©rfigyelĹ‘ kamerák működtetĂ©se mellett legtöbbször hangoztatott Ă©rveket. Elemzi a tĂ©rfigyelĹ‘ rendszerek működĂ©sĂ©nek elĂ©gtelensĂ©gĂ©t, Ă©s a privát szfĂ©rát, az emberi mĂ©ltĂłságot Ă©s a demokráciát veszĂ©lyeztetĹ‘ eszközkĂ©nt Ărja le ezeket. A cikk a hazánkban is egyre több helyen alkalmazott arcfelismerĹ‘ rendszerek veszĂ©lyeire hĂvja fel a figyelmet
Beyond water homeostasis:diverse functional roles of mammalian aquaporins
Background - Aquaporin (AQP) water channels are best known as passive transporters of water that are vital for water homeostasis. Scope of review - AQP knockout studies in whole animals and cultured cells, along with naturally occurring human mutations suggest that the transport of neutral solutes through AQPs has important physiological roles. Emerging biophysical evidence suggests that AQPs may also facilitate gas (CO2) and cation transport. AQPs may be involved in cell signalling for volume regulation and controlling the subcellular localization of other proteins by forming macromolecular complexes. This review examines the evidence for these diverse functions of AQPs as well their physiological relevance. Major conclusions - As well as being crucial for water homeostasis, AQPs are involved in physiologically important transport of molecules other than water, regulation of surface expression of other membrane proteins, cell adhesion, and signalling in cell volume regulation. General significance - Elucidating the full range of functional roles of AQPs beyond the passive conduction of water will improve our understanding of mammalian physiology in health and disease. The functional variety of AQPs makes them an exciting drug target and could provide routes to a range of novel therapies