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 szerző kísérletet tett arra, hogy egy, a legújabb európai kutatásokat felölelő, jegyzetekkel is ellátott bibliográfiát állítson össze. A rövid könyvismertetők előtt az európai és az amerikai információs társadalommal kapcsolatos kutatások ellentmondásainak és eredményeinek rövid összefoglalása olvasható. A kritikai igényű írás rávilágít az eltérő kutatási módszerek hiányosságaira, illetve szembeállítja az amerikaiak és az európaiak módszertanát, hozzáállását és eredményességét az információs társadalommal kapcsolatos kutatásokban

Az arcunk nem vonalkód: érvek a nyilvános helyeken elhelyezett automatikus arcfelismerő berendezések használata ellen

Philip E. Agre a világon egyre terjedő arcfelismerő rendszerek üzemeltetése ellen száll síkra, tételesen cáfolva a térfigyelő kamerák működtetése mellett legtöbbször hangoztatott érveket. Elemzi a térfigyelő rendszerek működésének elégtelenségét, és a privát szférát, az emberi méltóságot és a demokráciát veszélyeztető eszközként írja le ezeket. A cikk a hazánkban is egyre több helyen alkalmazott arcfelismerő rendszerek veszélyeire hívja fel a figyelmet

Malaria Antifolate Resistance With Contrasting Plasmodium Falciparum Dihydrofolate Reductase (DHFR) Polymorphisms in Humans and Anopheles Mosquitoes

Surveillance for drug-resistant parasites in human blood is a major effort in malaria control. Here we report contrasting antifolate resistance polymorphisms in Plasmodium falciparum when parasites in human blood were compared with parasites in Anopheles vector mosquitoes from sleeping huts in rural Zambia. DNA encoding P. falciparum dihydrofolate reductase (EC 1.5.1.3) was amplified by PCR with allele-specific restriction enzyme digestions. Markedly prevalent pyrimethamine-resistant mutants were evident in human P. falciparum infections - S108N (\u3e90%), with N51I, C59R, and 108N+51I+59R triple mutants (30-80%). This resistance level may be from selection pressure due to decades of sulfadoxine/pyrimethamine use in the region. In contrast, cycloguanil-resistant mutants were detected in very low frequency in parasites from human blood samples - S108T (13%), with A16V and 108T+16V double mutants (∼4%). Surprisingly, pyrimethamine-resistant mutants were of very low prevalence (2-12%) in the midguts of Anopheles arabiensis vector mosquitoes, but cycloguanil-resistant mutants were highly prevalent - S108T (90%), with A16V and the 108T+16V double mutant (49-57%). Structural analysis of the dihydrofolate reductase by in silico modeling revealed a key difference in the enzyme within the NADPH binding pocket, predicting the S108N enzyme to have reduced stability but the S108T enzyme to have increased stability. We conclude that P. falciparum can bear highly host-specific drug-resistant polymorphisms, most likely reflecting different selective pressures found in humans and mosquitoes. Thus, it may be useful to sample both human and mosquito vector infections to accurately ascertain the epidemiological status of drug-resistant alleles