4,049 research outputs found
Comment on "Chain Length Scaling of Protein Folding Time", PRL 77, 5433 (1996)
In a recent Letter, Gutin, Abkevich, and Shakhnovich (GAS) reported on a
series of dynamical Monte Carlo simulations on lattice models of proteins.
Based on these highly simplified models, they found that four different
potential energies lead to four different folding time scales tau_f, where
tau_f scales with chain length as N^lambda (see, also, Refs. [2-4]), with
lambda varying from 2.7 to 6.0. However, due to the lack of microscopic models
of protein folding dynamics, the interpretation and origin of the data have
remained somewhat speculative. It is the purpose of this Comment to point out
that the application of a simple "mesoscopic" model (cond-mat/9512019, PRL 77,
2324, 1996) of protein folding provides a full account of the data presented in
their paper. Moreover, we find a major qualitative disagreement with the
argumentative interpretation of GAS. Including, the origin of the dynamics, and
size of the critical folding nucleus.Comment: 1 page Revtex, 1 fig. upon request. Submitted to PR
Applications of Model Predictive Controllers in a Sugar Factory
INTERNATIONAL SYMPOSIUM ON ADVANCED CONTROL OF CHEMICAL PROCESSThis paper presents two applications of Model Predictive Control in a sugar factory: temperature control in the diffusion process and density control in the wastewater treatment plant. The implementation is done using a Generalized Predictive Controller (GPC) designed for a wide class of industrial process, with the same computational requirements as a PID routine and embedded in the existing control system. The processes have in common the existence of long and uncertain dead times, therefore the original GPC algorithm is improved by the use of the T polynomial, which increases the stability robustness by filtering the predictions.Comisión Interministerial de Ciencia y Tecnología (CICYT) TAP 96-0884Comisión Interministerial de Ciencia y Tecnología (CICYT) TAP 98-0541Comisión Interministerial de Ciencia y Tecnología (CICYT) 1FD97-083
Application of simple cascade GPC with robust behaviour to a sugar refinery
This paper presents the application of a Generalized Pre
dictive Controller (GPC) to sludge density control in a
sugar factory. The loop is controlled by a cascade strategy where both the master and the slave controllers are predic
tive ones. The control law is extremely simple to compute
and the tuning is straightforward since a method to im
plement GPC previously developed by the authors which
is very simple to implement and tune has been used. The
controllers are embedded in the existing control system
needing the same computational requirements as pid rou tines. The original GPC algorithm is improved by the use
of the socalled T polynomial which increases the stabil
ity robustness by ltering the predictions in order to cope
with model uncertainties and di erent process dynamics
caused by changes in the process operating pointsMinisterio de Ciencia y Tecnología s TAP 96-884 (CICYT)Ministerio de Ciencia y Tecnología TAP 95-370 (CICYT
Implementation of GPC for integrating··processes with low computational. Requirenients
This paper presents a straightforward method for implementing generalized predictive self-tuning controllers with low computational requirements. The method makes use of the fact that a generalized predictive controller results in a control law that can be described with few parameters.
The controller has been developed for processes having an integral effect. A set of simple functions relating the controller parameters to the process parameters has been obtained. With this set of functions either a fixed or a selftuning GPC can be implemented in a straightforward manner. An application to the control of a DC motor is given
A Broadband Bow-Tie Cavity-Backed Slot for Traveling-Wave Arrays in the Millimeter-Wave Band
The use of bow-tie geometries to enhance the characteristics of a radiating element previously proposed by
the authors is presented. The previous element consisted of a broadband cavity-backed slot in transmission configuration. The bow-tie shape of the cavity improves the bandwidth of the element and the bow-tie slot keeps constant the amount of power radiated. The structure is designed for the millimeterwave band. The enhancement of the element performance is shown through simulation results. A fractional bandwidth of
more than 100% is achieved in the 70 GHz band, and the radiated power remains almost constant throughout 30 GHz of the bandwidth. These results show a great improvement over the original radiating element. The radiating structure has the ideal characteristics for building series-fed reconfigurable arrays for wide-band applications in the millimeter-wave band.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.
This work was supported in part by the European Union’s
Horizon 2020 research and innovation programme under the
Marie Sklodowska-Curie grant agreement No. 706334, in part
by the Spanish Ministerio de Educaci´on, Cultura y Deporte
(Programa para la Formaci´on del Profesorado Universitario)
under Grant FPU15/06457 and in other part by the Spanish
Ministerio de Econom´ıa y Competitividad, under the project
ADDMATE TEC2016-76070-CR3-3-R
Antecedentes y desarrollo de la independencia ecuatoriana
El presente trabajo presenta una síntesis de la Independencia ecuatoriana, dividiéndola en tres apartados principales: la naturaleza o «carácter» de ese movimiento, los antecedentes que lo enmarcan y explican y su desarrollo desde 1808, cuando se formula un primer proyecto que llevaría a conseguir la Independencia, hasta 1830, cuando efectivamente se establece la República del Ecuador como Estado independiente
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