experiment. Electrophysiologists have described neurons in striate cortex that are selectively sensitive to certain visual properties; for reviews, see Hubel (1988) and DeValois and DeValois (1988). Psychophysicists have inferred the existence of channels that are tuned for certain visual

Emerging adulthood is proposed as a new conception of development for the period from the late teens through the twenties, with a focus on ages 18-25. A theoretical back-ground is presented, Then evidence is provided to support the idea that emerging adulthood is a distinct period de

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The objective of this article is to give a tutorial on lattice-based access control models for computer security. The paper begins with a review of Denning's axioms for information flow policies, which provide a theoretical foundation for these models. The structure of security labels in the military and government sectors, and the resulting lattice is discussed. This is followed by a review of the Bell-LaPadula model, which enforces information flow policies by means of its simple-security and *-properties. It is noted that information flow through covert channels is beyond the scope of such access controls. Variations of the Bell-LaPadula model are considered. The paper next discusses the Biba integrity model, examining its relationship to the Bell-LaPadula model. The paper then reviews the Chinese Wall policy, which arises in a segment of the commercial sector. It is shown how this policy can be enforced in a lattice framework.

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This book presents a unified treatment of many different kinds of planning algorithms. The subject lies at the crossroads between robotics, control theory, artificial intelligence, algorithms, and computer graphics. The particular subjects covered include motion planning, discrete planning, planning under uncertainty, sensor-based planning, visibility, decision-theoretic planning, game theory, information spaces, reinforcement learning, nonlinear systems, trajectory planning, nonholonomic planning, and kinodynamic planning.

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of communication (for example, number, navigation, and social relations). If a martian graced our planet, it would bestruck by one remarkable similarity amongEarth’s living creatures and a key difference. Concerning similarity, it would note that all living things are de-