1,501 research outputs found
Experimental analysis on the mechanism of moisture induced interface weakening in ACF package
No full textThis work was financially supported by the
Fundamental R&D Program for Core Technology of
Materials funded by the Ministry of Knowledge
Economy, Republic of Korea
Ck-Log, A Calculus for Knowledge Processing in Logic
No full textThis 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
Asymptotic behavior of underlying NT paths in interior point methods for monotone semidefinite linear complementarity problems
No full textAn interior point method (IPM) defines a search direction at each interior point of the feasible region. These search directions form a direction field, which in turn gives rise to a system of ordinary differential equations (ODEs). Thus, it is natural to define the underlying paths of the IPM as solutions of the system of ODEs. In Sim and Zhao (Math. Program. Ser. A 110:475–499, 2007), these off-central paths are shown to be well-defined analytic curves and any of their accumulation points is a solution to the given monotone semidefinite linear complementarity problem (SDLCP). In Sim and Zhao (Math. Program. Ser. A 110:475–499, 2007; J. Optim. Theory Appl. 137:11–25, 2008) and Sim (J. Optim. Theory Appl. 141:193–215, 2009), the asymptotic behavior of off-central paths corresponding to the HKM direction is studied. In particular, in Sim and Zhao (Math. Program. Ser. A 110:475–499, 2007), the authors study the asymptotic behavior of these paths for a simple example, while, in Sim and Zhao (J. Optim. Theory Appl. 137:11–25, 2008) and Sim (J. Optim. Theory Appl. 141:193–215, 2009), the asymptotic behavior of these paths for a general SDLCP is studied. In this paper, we study off-central paths corresponding to another well-known direction, the Nesterov-Todd (NT) direction. Again, we give necessary and sufficient conditions for these off-central paths to be analytic w.r.t. √μ and then w.r.t. μ, at solutions of a general SDLCP. Also, as in Sim and Zhao (Math. Program. Ser. A 110:475–499, 2007), we present off-central path examples using the same SDP, whose first derivatives are likely to be unbounded as they approach the solution of the SDP. We work under the assumption that the given SDLCP satisfies a strict complementarity condition.Department of Applied Mathematic
On the analyticity of underlying HKM Paths for monotone semidefinite linear complementarity problems
No full textAn interior point method (IPM) defines a search direction at an interior point of the feasible region. These search directions form a direction field, which in turn defines a system of ordinary differential equations (ODEs). The solutions of the system of ODEs are called off-central paths, underlying paths lying in the interior of the feasible region. It is known that not all off-central paths are analytic, whether w.r.t. μ or √μ, where μ represents the duality gap, at a solution of a given semidefinite linear complementarity problem, SDLCP (Sim and Zhao, Math. Program. 110:475-499, 2007). In Sim and Zhao (J. Optim. Theory Appl. 137:11-25, 2008), we give a necessary and sufficient condition for when an off-central path is analytic as a function of √μ at a solution of a general SDLCP. It is then natural to ask about the analyticity of a SDLCP off-central path at a solution, as a function of μ. We investigate this in the current paper. Again, we work under the assumption that the given SDLCP satisfies strict complementarity condition.Department of Applied Mathematic
The simvastatin on plasma creatine kinase (CK) activity and total cholesterol.
No full text<p>Rats were treated with vehicle (Control) or simvastatin at 60 (Sim 60) and 80 mg.kg<sup>-1</sup>.day<sup>-1</sup> (Sim 80) for 14 days. (<b>A</b>) Plasma CK activity. (<b>B</b>) Plasma [total cholesterol]. *—significantly different from Control and Sim 60 groups. Mean ± SEM. n = 8/group. One way ANOVA with Newman-Keul’s post-hoc test. P < 0.05.</p
Highly parallel and energy-efficient exhaustive minimum distance search engine using hybrid digital/analog circuit techniques
No full textA minimum distance search engine (MDSE) is presented as a hardware. accelerator for various exhaustive pattern-matching systems. This chip executes highly parallel computations of L-1-norms between an input query and stored multiple reference records, and searches for the minimum distance among them in a highly parallel fashion. Our architectural-level estimation shows that this MDSE can reduce energy dissipation by orders of magnitude as the number of records increases, compared with the conventional systems. We have designed a prototype 4-bit 8-word MDSE composed of merged memory logic (MML) and digital/analog-mixed winner-take-all circuit (DAM-WTAC) by using hybrid digital/analog circuit techniques. It was fabricated with a 0.6-mum single-poly triple-metal CMOS technology. Experimental results show that our chip works properly at 3 V/10 MM and has approximately four times larger throughput as well as four times higher energy efficiency, compared with the existing 8-bit microcontrollers.The author would like to thank MICROS, IDEC and Samsung Electronics
Company for their support. They would also like to thank the
reviewers for their valuable comments and Dr. K. Kim, Samsung Electronics
Company, for useful discussion
Feasibility and accuracy of 64-row MDCT coronary imaging from a centre with early experience : a review and comparison with established centres
No full textOng K., Chin SP., Chan WL., Liew CK., Seyfarth MT., Liew HB., Rapaee A., Sim KH
Superlinear convergence of an infeasible predictor-corrector path-following interior point algorithm for a semidefinite linear complementarity problem using the Helmberg-Kojima-Monteiro direction
No full textAn interior point method (IPM) defines a search direction at each interior point of a region. These search directions form a direction field which in turn gives rise to a system of ordinary differential equations (ODEs). The solutions of the system of ODEs can be viewed as underlying paths in the interior of the region. In [C.-K. Sim and G. Zhao, Math. Program. Ser. A, 110 (2007), pp. 475–499], these off-central paths are shown to be well-defined analytic curves, and any of their accumulation points is a solution to a given monotone semidefinite linear complementarity problem (SDLCP). The study of these paths provides a way to understand how iterates generated by an interior point algorithm behave. In this paper, we give a sufficient condition using these off-central paths that guarantees superlinear convergence of a predictor-corrector path-following interior point algorithm for SDLCP using the Helmberg–Kojima–Monteiro (HKM) direction. This sufficient condition is implied by a currently known sufficient condition for superlinear convergence. Using this sufficient condition, we show that for any linear semidefinite feasibility problem, superlinear convergence using the interior point algorithm, with the HKM direction, can be achieved for a suitable starting point. We work under the assumption of strict complementarity.Department of Applied Mathematic
Variability study of Si nanowire FETs with different junction gradients
No full textRandom dopant fluctuation effects of gate-all-around Si nanowire field-effect transistors (FETs) are investigated in terms of different diameters and junction gradients. The nanowire FETs with smaller diameters or shorter junction gradients increase relative variations of the drain currents and the mismatch of the drain currents between source-drain and drain-source bias change in the saturation regime. Smaller diameters decreased current drivability critically compared to standard deviations of the drain currents, thus inducing greater relative variations of the drain currents. Shorter junction gradients form high potential barriers in the source-side lightly-doped extension regions at on-state, which determines the magnitude of the drain currents and fluctuates the drain currents greatly under thermionic-emission mechanism. On the other hand, longer junction gradients affect lateral field to fluctuate the drain currents greatly. These physical phenomena coincide with correlations of the variations between drain currents and electrical parameters such as threshold voltages and parasitic resistances. The nanowire FETs with relatively-larger diameters and longer junction gradients without degrading short channel characteristics are suggested to minimize the relative variations and the mismatch of the drain currents. (C) 2016 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).1163Ysciescopu
Phenazine-1-carboxylic acid (PCA) produced by Paraburkholderia phenazinium CK-PC1 aids postgermination growth of Xyris complanata seedlings with germination induced by Penicillium rolfsii Y-1
No full textSymbiosis of Penicillium rolfsii Y-1 is essential for the seed germination of Hawaii yellow-eyed grass (Xyris complanata). However, the local soil where the plants grow naturally often suppresses the radicle growth of the seedlings. This radicle growth was drastically restored by coinoculation of Paraburkholderia phenazinium isolate CK-PC1, which is a rhizobacterium of X. complanata. It was found that the isolate CK-PC1 produced phenazine-1-carboxylic acid (PCA, 1) as a major metabolite. The biological effects of PCA (1) were investigated using the seeds of X. complanata and Mung bean (Vigna radiata) and it was uncovered that the symbiosis of the isolate CK-PC1was essential for the postgermination growth of X. complanata and the metabolite PCA (1) might partially contribute to promote the growth of the plants
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