236 research outputs found
Virtual Symposium on Virtual Mind
No full textWhen certain formal symbol systems (e.g., computer programs) are implemented as dynamic physical symbol
systems (e.g., when they are run on a computer) their activity can be interpreted at higher levels (e.g., binary code can be
interpreted as LISP, LISP code can be interpreted as English, and English can be interpreted as a meaningful conversation).
These higher levels of interpretability are called "virtual" systems. If such a virtual system is interpretable as if it had a mind, is
such a "virtual mind" real? This is the question addressed in this "virtual" symposium, originally conducted electronically among
four cognitive scientists: Donald Perlis, a computer scientist, argues that according to the computationalist thesis, virtual minds are
real and hence Searle's Chinese Room Argument fails, because if Searle memorized and executed a program that could pass the
Turing Test in Chinese he would have a second, virtual, Chinese-understanding mind of which he was unaware (as in multiple
personality). Stevan Harnad, a psychologist, argues that Searle's Argument is valid, virtual minds are just hermeneutic
overinterpretations, and symbols must be grounded in the real world of objects, not just the virtual world of interpretations.
Computer scientist Patrick Hayes argues that Searle's Argument fails, but because Searle does not really implement the program:
A real implementation must not be homuncular but mindless and mechanical, like a computer. Only then can it give rise to a mind
at the virtual level. Philosopher Ned Block suggests that there is no reason a mindful implementation would not be a real one
Nonmonotonicity and the Scope of Reasoning: Preliminary Report
No full textExisting formalisms for default reasoning capture some aspects of the nonmonotonicity of human commonsense reasoning. However, Perlis has shown that one of these formalisms, circumscription, is subject to certain counterintuitive limitations. Kraus and Perlis suggested a partial solution, but significant problems remain. In this paper, we observe that the unfortunate limitations of circumscription are even broader than Perlis originally pointed out. Moreover, these problems are not confined to circumscription; they appear to be endemic in current nonmonotonic reasoning formalisms. We develop a much more general solution than that of Kraus and Perlis, involving restricting the scope of nonmonotonic reasoning, and show that it remedies these problems in a variety of formalisms. Introduction The search for theories of nonmonotonic reasoning--- theories of how to reach reasonable conclusions that are not strictly entailed by what is known, and hence are subject to retraction---has yielde..
Stop the World - I Want to Think
No full textReason-based actions plunge the reasoner into temporal considerations from all angles. We see this not only when time enters explicitly into the problem statement, but also in formal robot blocks-world scenarios, in the Yale Shooting Problem and other associated versions of the frame problem (e.g., [Hanks and McDermott, 1986] ), in various specialized actions (e.g., hiding, as in [Allen, 1984] ), and so on. In short, where there is action, there is time, and where there is time, there is a potential need for reasoning about time. Where, then, is the action? It certainly includes the usual overt physical acts of motion, and also certain covert behaviors such as hiding or watching. In these of course time is important. But there is another angle that is not usually noted, one that we have been exploring for the past several years ([Drapkin and Perlis, 1986b] , [Drapkin and Perlis, 1986a] , [ElgotDrapkin, 1988] , [Elgot-Drapkin and Perlis, 1990] ). Namely, action also occurs in the form o..
Logic, self-awareness and self-improvement: The metacognitive loop and the problem of brittleness
No full textThis essay describes a general approach to building perturbation-tolerant autonomous systems, based on the conviction that artificial agents should be able notice when something is amiss, assess the anomaly, and guide a solution into place. We call this basic strategy of self-guided learning the metacognitive loop; it involves the system monitoring, reasoning about, and, when necessary, altering its own decision-making components. In this essay, we (a) argue that equipping agents with a metacognitive loop can help to overcome the brittleness problem, (b) detail the metacognitive loop and its relation to our ongoing work on time-sensitive commonsense reasoning, (c) describe specific, implemented systems whose perturbation tolerance was improved by adding a metacognitive loop, and (d) outline both short-term and long-term research agendas
A frequency-reconfigurable microstrip antenna with constant dipole-like radiation patterns using single bias, triple varactor tuning with reduced complexity
No full textThis work proposes a novel frequency-reconfigurable circular patch antenna incorporated with a rectangular slot and a narrow slot capable of producing constant dipole-like radiation patterns. The antenna compactness is achieved with the integration of the rectangular slot defected ground structure (DGS) on the ground. The proposed antenna is able to perform continuous frequency tuning between 1.91 and 2.77 GHz with a frequency ratio of 1.5:1, in addition to stable dipole-like radiation patterns. The resonant frequency of the antenna is controlled by tuning a simple DC biasing network that consists of three RF varactor diodes located on the narrow slot DGS. Implementing the DC biasing network at the narrow slot DGS while maintaining the large slot DGS helps the antenna miniaturization and maintains the constant dipole-like radiation pattern over all frequency tuning range. The results are validated via simulations and experimental validations in terms of reflection coefficients and the radiation patterns. Measurements indicated that an impedance bandwidth of 85 MHz is featured for each tuned frequency band, with dipole-like patterns and an average gain of 1.57 dBi
Evidence of Coulomb correction and spinorbit coupling in rare-earth dioxides CeO 2, PrO 2 and TbO 2: An ab initio study
No full textThe current study investigates the structural, elastic, electronic and optical properties of CeO 2, PrO 2 and TbO 2 using the full potential (linearized) augmented plane wave plus local orbital method within the WuCohen generalized gradient approximation (GGA) with Hubbard (U) correction and spinorbit coupling (SOC). The GGAU implementation lead us to describe correctly the relativistic effect on 4f electrons for CeO 2. We clarify that the inclusion of the Hubbard U parameter and the spinorbit coupling are responsible for the ferromagnetic insulating of PrO 2 and TbO 2. The magnetic description is achieved by the spin-density contours and magnetic moment calculations, where we show the polarization of oxygen atoms from the rare earth atoms. The mechanical stability is shown via the elastic constants calculations. The optical properties, namely the dielectric function and the reflectivity are calculated for radiation up to 12 eV, giving interesting optoelectronic properties to these dioxides. © 2011 Elsevier B.V. All rights reserved.A part of calculations with Wien2k and VASP codes have been performed in ISCF computers of FUNDP University (Belgium) during the research stays of S.G.-S. and M.B.K. VASP calculations were carried out partially in the Beowulf class heterogeneous computer cluster at KAUST. S.G.-S. and M.B.K. wish to thank Alberto Otero de la Roza from Universidad de Oviedo (Spain) for providing us with RUNWIEN code. For the author A.H.R., his work was supported from the program RDI of the Czech Republic, the project CENAKVA (No. CZ.1.05/2.1.00/01.0024), the Grant no. 152/2010/Z of the Grant Agency of the University of South Bohemia. School of Material Engineering, Malaysia University of Perlis, P.O. Box 77, d/a Pejabat Pos Besar, 01007 Kangar, Perlis, Malaysia
Virtual Symposium on Virtual Mind
No full textWhen certain formal symbol systems (e.g., computer programs) are implemented as dynamic physical symbol systems (e.g., when they are run on a computer) their activity can be interpreted at higher levels (e.g., binary code can be interpreted as LISP, LISP code can be interpreted as English, and English can be interpreted as a meaningful conversation). These higher levels of interpretability are called "virtual" systems. If such a virtual system is interpretable as if it had a mind, is such a "virtual mind" real? This is the question addressed in this "virtual" symposium, originally conducted electronically among four cognitive scientists: Donald Perlis, a computer scientist, argues that according to the computationalist thesis, virtual minds are real and hence Searle's Chinese Room Argument fails, because if Searle memorized and executed a program that could pass the Turing Test in Chinese he would have a second, virtual, Chinese-understanding mind of which he was unaware (as in multiple personality). Stevan Harnad, a psychologist, argues that Searle's Argument is valid, virtual minds are just hermeneutic overinterpretations, and symbols must be grounded in the real world of objects, not just the virtual world of interpretations. Computer scientist Patrick Hayes argues that Searle's Argument fails, but because Searle does not really implement the program: A real implementation must not be homuncular but mindless and mechanical, like a computer. Only then can it give rise to a mind at the virtual level. Philosopher Ned Block suggests that there is no reason a mindful implementation would not be a real one
Autocircumscription
No full textReasoning can be used to select among various possible interpretations of events. But how are these possibilities determined? We isolate two key technical features of circumscription (consistency and minimization), and use the first as the basis for a reformulation of the circumscription principle in a way related to possibility, self knowledge, and negative introspection. The second (minimization) then can be separately expressed on its own. Conceptual clarity and a kind of validity are results of this separation, as well as a computational means to determine (sometimes) when a wff isnot among a reasoner’s conclusions. I
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