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MD control performance

MD control performance is evaluated directly from the closed-loop time series data ymd Let deviation variable yt represent the measurement signal at time t. One way of representing yt in terms of previous measurements is through a moving average (MA) correlation model... [Pg.269]

Analysis of full sheet data is useful for process performance evaluations and product value calculations. For feedback control or any other on-line application, it is necessary to continuously convert scanner data into a useful form. Consider the data vector Y ,k) for scan number k. It is separated into its MD and CD components as Y( , A ) = yM )( )+Yc )( , k) where Ymd ) s the mean of Y ,k) as a scalar and YcD -,k) is the instantaneous CD profile vector. MD and CD controllers correspondingly use these calculated measurements as feedback data for discrete time k. Univariate MD controllers are traditional in nature with only measurement delay as a potential design concern. On the other hand, CD controllers are multivariate in form and must address the challenges of controller design for large dimensional correlated systems. [Pg.256]

Figure 10.21. Normalized performance index NPI of Ymd to measure MD control improvement potential. Figure 10.21. Normalized performance index NPI of Ymd to measure MD control improvement potential.
MD controls are slow but complex control loops. Only two to three measurements are available per minute. Using interpolation techniques or Kalman filters, control steps can be performed every 5 to 10 s. MD controls are complex because of the considerably large transport dead time between actuators (i.e. stock valve) and measurement (i.e. scanner at the reel), which is typically larger than 1 min. [Pg.403]

Quality Assurance/Quality Control. QA/QC measures included field blanks, solvent blanks, method blanks, matrix spikes, and surrogates. Percent recovery was determined using three surrogate compounds (nitrobenzene-d5, 2-fluorobiphenyl, d-terphenyl-diQ and matrix spikes (naphthalene, pyrene, benzo[ghi]perylene) the recoveries ranged from 80 to 102%. Separate calibration models were built for each of the 16 PAHs using internal standards (naphthalene-dg, phenanthrene-dio, perylene-di2). Validation was performed using a contaminated river sediment (SRM 1944) obtained from NIST (Gaithersburg, MD) accuracy was <20% for each of the 16 analytes. [Pg.90]

At this point some misleading nomenclature in publications of simulations has to be clarified. Frequently simulations based on DFT functionals are termed ab initio MD and first principle or -empirical. This is indeed not correct as all available density functionals are of a more or less semiempirical nature, as pointed out by their developers themselves, e.g., by Becke in his presentation of the B3LYP functional (15). The term ab initio should be reserved, therefore, for simulations where for the QM part a true ab initio procedure, i.e., HF or correlated methods like MP/2 or better, is employed. Only by this one is also enabled to perform a method-inherent control of accuracy and deficiencies by increasing the level of theory from a one-determinantal to a multi-determinantal method. [Pg.147]

CMA. 1984. Voluntary Testing Program under Section 4 of the Toxic Substances Control Act. Submission of Test Data. Volume III. Isophorone Mutagenicity Studies. Unpublished studies performed by Microbiological Associates, Bethesda, MD for Chemical Manufacturers Association, Washington, DC. OTS Section 4 submission. Doc. ID. 40-8455047. Microfiche No. OTS0507222. [Pg.99]

Fig. 6.2.2a-bc High-performance liquid chromatography (HPLC) with electrochemical (EC) detection of neurotransmitter metabolites, a standard mixture b cerebrospinal fluid (CSF) sample - control c CSF sample - aromatic amino acid decarboxylase (AADC) deficiency. Peak identification 1 = 5HIAA (7.7 min), 2 = 3-MD (9.6 min), 3 = HVA (11.7 min)... [Pg.708]

Another method of controlling the temperature that can be used in CP MD is the stochastic thermostat of Andersen.27 In this approach the velocity of randomly selected nucleus is rescaled this corresponds in a way to the stochastic collisions with other particles in the system. Therefore, this approach is often called a stochastic collision method. The Andersen thermostat has recently been shown28 to perform very well in the Car-Parinello molecular dynamic simulations of bimolecular chemical reactions. [Pg.232]

The time-step of 0.5 fs is used to simulate the dynamic system to 4.0 ps. The temperature of 300 K is used throughout the simulations. The MD simulations are performed using the Nose-Hoover thermostat for temperature control. The Hellmann-Feynman forces acting on the atoms are calculated from the ground-state electronic energies at each time step and are subsequently used in the integration of Newton s equation of motion. [Pg.570]

Student s f-test is performed to determine the significance of changes in clinical pathology values obtained in CD2F1 mice treated with md-LErafAON and control groups. Analysis includes both short-term and long-term treatment groups of these mice. [Pg.71]

Orientation consists of a controlled system of stretching TP molecules in unioriented [unidirectional (UD)] or bioriented [biaxial direction (BD)]. UD orientation can be in the machine direction (MD) or transverse direction (TD).207 Orientation improves strength, stiffness, optics, electrical, and/or other properties with the usual result that improved product performance-to-cost occur. This technique is used during the processing of many different products such as films, sheets, pipes, fibers, tapes, etc. [Pg.269]

Systems approach borrowed from the optimization and control communities can be used to achieve various other tasks of interest in multiscale simulation. For example, Hurst and Wen (2005) have recently considered shear viscosity as a scalar input/output map from shear stress to shear strain rate, and estimated the viscosity from the frequency response of the system by performing short, non-equilibrium MD. Multiscale model reduction, along with optimal control and design strategies, offers substantial promise for engineering systems. Intensive work on this topic is therefore expected in the near future. [Pg.54]

Dukovic and Tobias [58] performed a simulation of leveling in a V groove profiles for Watts nickel plating with added coumarin, as investigated experimentally by Kruglikov et al. [59]. It was reasoned that inhibitors described by the diffusion theory of leveling [60, 61] could be assumed to operate under diffusion control and that the overpotential should be a function of current density md inhibitor flux. A... [Pg.141]


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See also in sourсe #XX -- [ Pg.269 ]

See also in sourсe #XX -- [ Pg.269 ]




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