1,758 research outputs found

    Ck-Log, A Calculus for Knowledge Processing in Logic

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    This paper introduces the principal concepts in the organization and operation of the logic based knowledge processing system, called CK-LOG (A Calculus for Knowledge in Logics). CK-LOG uses the frame based system MDS (the Meta Description System) for knowledge representation and for modeling world states. It uses an inference engine based on Natural Deduction for stating and solving problems. As a knowledge processing system CK-LOG has several capabilities, which are new to the technology of knowledge representation systems: CK-LOG has special facilities to represent and reason about actions and their time dependencies. Actions that occur in a world state may create or destroy objects in the world or modify their properties, or prevent or support other actions. The effects of actions are described in CK-LOG using modal operators like CREATE, DESTROY, PREVENT, SUPPORT, KEEP, etc. These operator expressions are also used to represent and reason about possible worlds that the actions might lead to. Most significantly, CK-LOG is a logic-based knowledge processing system, just as PROLOG is logic based programming system. CK-LOG uses a three valued logical system with truth values T (true),? (Unknown) and F (false) to build partial models of world states, and the two valued logic's system of T and F in its theorem proving System. The use of the three valued logical system in its models of world states enables CK-LOG to do problem solving in the context of incomplete information about world states. The theorem proving system of CK-LOG uses a variant of the calculus of sequents first proposed by Kanger (which itself is a variant of Gentzen's system). The two variations in CK-LOG are, (i). the use of a new algorithm called the mating algorithm for testing proof terminations, and (ii) the use of specialized inference rules for reasoning about modal expressions using the possible world semantics.. The mating algorithm gives the theorem proving system of CK-LOG several new capabilities: to identify information that is pertinent to a given problem and retrieve it from its knowledge base, to update its models of possible worlds during the problem solving process based on the findings of the theorem proving system, to use these models of world states to test proof terminations, and to generate hypotheses during the problem solving process that are based on unknown information. These various features of CK-LOG are described here. The paper concludes with a discussion of the logic of frames as used in CK-LOG and establishes a condition called locality condition as a sufficient condition for creating knowledge representations with requisite completeness.Technical report DCS-TR-15

    Effect of conductive particle properties on the reliability of anisotropic conductive film for chip-on-glass applications

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    This paper describes how the material properties of conductive particles in anisotropic conductive films (ACFs) affect the electrical conductivity and the reliability of ACF interconnections for chip-on-glass (COG) applications. For the conductive particles, Au/Ni-coated polymer particles with a 5-mu m diameter were used. Two different types of conductive particles were characterized with respect to their mechanical and electrical properties, such as ball hardness, recovery behavior, and electrical resistance. In addition, two ACFs were fabricated in the form of a double-layered structure, in which the thickness of the ACF and a nonconductive film (NCF) layer were optimized to have as many conductive particles as possible on the bump after COG bonding. The electrical contact resistance of an ACF interconnection in a COG structure depends mainly on the electrical properties of conductive particles in the ACF. The electrical reliability of an ACF interconnection in a COG structure also depends more on the electrical properties than the mechanical properties of conductive particles under a high-temperature and humid condition. Conductive particles with a lower electrical resistance, higher mechanical hardness, and lower recovery rate show better reliability than conductive particles with a higher electrical resistance, lower mechanical hardness, and higher recovery rate. Cross-sectional scanning electron microscopic (SEM) pictures of a COG interconnection show the deformation of two different conductive particles after the reliability tests. The ACF interconnections in the edge or corner of a driver IC show less reliable joints due to high absorption of moisture

    Surface micromachined solenoid on-Si and on-glass inductors for RF applications

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    RF performance of surface micromachined solenoid on-chip inductors fabricated on a standard silicon substrate (10 Omega. cm) has been investigated and the results are compared with the same inductors on glass, The solenoid inductor on Si with a 15-mu m thick insulating layer achieves peak quality (Q-) factor of 16.7 at 2.4 GHz with inductance of 2.67 nH, This peak Q-factor is about two-thirds of that of the same inductor fabricated on glass. The highest performance has been obtained from the narrowest-pitched on-glass inductor, which shows inductance of 2.3 nH, peak Q-factor of 25.1 at 8.4 GHz, and spatial inductance density of 30 nH/mm(2), Both on-Si and on-glass inductors have been modeled by lumped circuits, and the geometrical dependence of the inductance and Q-factor have been investigated as well
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