25 research outputs found

    Linear motor for multi-car elevators, design and position measurement

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    Multi-car elevator is an emerging technology consisting of two or more elevator cars moving independently in an elevator hoistway, which has become more appealing as building heights increase. In this paper, the design and drive methodologies for a linear motor driven multi-car elevator system with independently moving cars is introduced together with experimental results. Additionally, a safety method developed for the linear motor elevator and the conditions necessary for its proper operation are discussed. The new results introduced in this paper are in the areas of the design method of the linear motor for multi-car elevator system, and the preliminary results for the position measurement system

    A Network Analogy for Three-dimensional Eddy Current Problems

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    We present a numerical method for the solution of eeddy current problems arising in the analysis of electric machines. The method is based on a network analogy which is equivalent to a differential-integral equation formulation of Maxwell's equations, using the Biot-Savart Law. The present approach is intended mainly to give an intuitive picture rather than to be used as a general method for solving practical problems. A more effective method is presented in a companion article, where we start from a direct mathematical formulation

    Numerical Solution of Three-dimensional Eddy Current Problems

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    A general numerical method is given for the solution of quasi-stationary electromagnetic field problems. The integral equation-type formulation used permits the elimination of field quantities of inactive regions (air etc.) from the calculation. Some difficulties present in other methods (like surface charges etc.) are also avoided. The use of global variables in connection with the coordinate-independent (tensorial) form of the basic equations is likely to be helpful for an easy definition of a class of practical problems for a general computer program. A numerical example is included

    Optimal Elevator Group Control by Evolution Strategies

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    Efficient elevator group control is important for the operation of large buildings. Recent developments in this field include the use of fuzzy logic and neural networks. This paper summarizes the development of an evolution strategy (ES) that is capable of optimizing the neuro-controller of an elevator group controller. It extends the results that were based on a simplified elevator group controller simulator. A threshold selection technique is presented as a method to cope with noisy fitness function values during the optimization run. Experimental design techniques are used to analyze first experimental results

    Design and implementation of a linear motor for multi-car elevators

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    The multi-car elevator system is a revolutionary new technology for high-rise buildings, promising outstanding economic benefits, but also requiring new technology for propulsion, safety and control. In this paper we report on experimental results with new components for linear motor driven multi-car elevators. We show that linear synchronous motors with optimized design and with our new safety and control system can be considered as core components of a new generation of elevator systems. The main new results concern the development of a safety system integrated into the propulsion system, the design methodology of a linear motor optimized for the multi-car elevator task, and the motion control system that is expected to be usable for extra high-rise buildings

    LOCAL PROPERTIES OF THE HOCHSCHILD COHOMOLOGY OF C*-ALGEBRAS

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    Let A be a C*-algebra, and let X be a Banach A-bimodule. Johnson [B.E.Johnson, ‘Local derivations on C*-algebras are derivations', Trans. Amer. Math. Soc. 353 (2000), 313-325] showed that local derivations from A into X are derivations. We extend this concept of locality to the higher cohomology of a C*-algebra and show that, for every nNn\in \mathbb {N}, bounded local n-cocycles from A(n) into X are n-cocycle

    Threshold Selection, Hypothesis Tests, and DOE Methods

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    Threshold selection -- a selection mechanism for noisy evolutionary algorithms -- is put into the broader context of hypothesis testing. Theoretical results are presented and applied to a simple model of stochastic search and to a simplified elevator simulator. Design of experiments methods are used to validate the significance of the results
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