Time variance

The direct-labor-cost variance can, if necessary, be broken down into a direc t-labor-idle-time variance in addition to the direct-wage-rate and direct-labor-efficiency variances. The direc t-labor-idle-time variance is simply the number of idle labor-hours in the period multiplied by the standard wage rate. This is rarely relevant to the conditions existing in process plants except when maintenance is involved. 

Table 8-3 gives the parameters for calculating the mean residence time, variance, E(6), F(6), and 1(6) values. The mean residence time f with 6t = 2.5 is... 

Based on the survey, the actual costs normally associated with the maintenance operation were reduced by more than 50 per cent. The comparison of maintenance costs included the actual labor and overhead of the maintenance department. It also included the actual materials cost of repair parts, tools and other equipment required to maintain plant equipment. The analysis did not include lost production time, variances in direct labor or other costs that should be directly attributed to inefficient maintenance practices. 

Each beer sample was measured 10 times (variance <5.5%). 

Depending on its design, the detector cell can be considered either as a tube with plug flow or as a mixing chamber. More probably, however, it is an intermediate system between these two limits (45). In the least favorable situation, the contribution to time variance, orf, is given by... 

Table 6.7 illustrates example 5. In example 5, consider an infinite horizon with 6 =. 99. To model the time variance of myopia in a simple and extreme way, suppose that P, = 1 for odd t and pt - 0 for even /. TCs refrain always, since any other course of action yields a negative average utility. Hitting always yields utility profile 2, -1, -1, -1,..., and the cost of refraining when hooked (-5) outweighs the benefit of hitting when unhooked (2), so any pattern of moderate consumption also will not be attractive. 

At Clariant, for instance, we focus on increasing time yield and efficiency per employee by systematically analyzing throughput time variances and optimizing production processes continuously. Here, a globally operating rapid process development unit comprised of experienced senior technologists is key for success. 

A pulse of tracer is fed to the reactor and the following exit concentrations are reported. Determine the mean residence time, variance, E(0), F(0), and 1(0) distribution curves from the effluent tracer concentration as shown in Table 8-2. 

A one-dimensional search optimization technique, such as the Fibonacci search, is employed to minimize Equation 8-113. A computer program (PROG81) was developed to estimate the equivalent number of ideal tanks N for the given effluent tracer response versus time data. Additionally, the program calculates the mean residence time, variance, dimensionless variance, dispersion number, and the Peclet number. 

In polymers, it is always observed that a packet of carriers spreads faster with time than predicted by Eq. (30). Thus, the spatial variance of the packet yields an apparent diffusivily that exceeds the zero-field diffusivity predicted by the Einstein relationship. Further, the pholocurrent transients frequently do not show a region in which the photocurrent is independent of time. As a result, inflection points, indicative of the arrival of the carrier packet at an electrode, can only be observed by plotting the time variance of the photocurrent in double logarithmic representation. The explanation of this behavior, as originally proposed by Scher and Lax (1972, 1973) and Scher and Montroll (1975), is that the carrier mean velocity decreases continuously and the packet spreads anomalously with time, if the time required to establish dynamic equilibrium exceeds the average transit time. Under these conditions, the transport is described as dispersive. There have been many models proposed to describe dispersive transport. Of these, the formalism of Scher and Montroll has been the most widely used. 

Furthermore, the recognition of variations across the different scales of spatial and temporal dimensions would enable the identification of shifting therapeutic targets to address both of the individual and the time variances in personalized medicine (see Fig. 1). Accurate and robust biomarkers can also be useful for the stratification of diseases and classification of patient subgroups for more effective prevention and therapy. The prediction of drug responses would in turn help avoid adverse events for better clinical outcomes. In addition, the construction of dynamic disease predictive networks derived from the analyses of omics data would allow for the transition from reactive treatments to holistic and proactive care. With the transformation from disease-centered to human-based care, the systems and dynamical models would provide patient-centric information to enhance the participation of individuals, the goal of participatory medicine. 

The second moment m2j of a peak i with the distribution function y,(f) is related to the retention time mu and as the central moment represents the peak time variance [Pg.330]

The demands can be derived simply from basic equations. The time variance of... 

Theoretically the best method to eliminate a time-variance error in deconvolution is to use a simultaneous reference administration of a tracer form of the drug. This will eliminate the error if the time variance is a between experiments disposition change. A within experiments time variance error will be reduced but not eliminated by this advanced approach. 

From standard queuing results, the marginal distribution of 7Q follows a Poisson distribution with mean = AE[LJ, which depends on the lead time distribution G only through its mean. This implies that the higher moments of the lead time (variance in particular) do not affect the item-based performance. This is no longer true, however, for the joint distribution of (7Q, i = 1,. . . , m) as we shall see below. 

Drzewiecki, G.M, Karam, E., and Welkowitz, W. 1989. Physiological basis for mechanical time-variance in the heart special consideration of non-Unear function. J. Theor. Biol. 139 465-486. 

This description of value states that value is a function of quality, as perceived by the customer the delivery of the product which could represent the actual lead time, variance in the lead time, or the method of delivery and the firms flexibility. Further, the equation states that customers perceive these benefits of the product in relation to the cost of the product. 

Discuss how you would decide between a freight transit mode that is faster (i.e., lower mean transit time), but less reliable (i.e., higher transit time variance), and a mode that is slower but more reliable What aspects of the joint transportation-inventory models discussed in this chapter are affected by the mode choice and how could you use that knowledge in building a means of comparing fhese two hypothetical modes ... 

FT-EIS allows for measurements of nonstationary systems evolving slowly with time or during a potential sweep. In addition, it allows for detecting and quantifying the presence of time variance and nonlinear distortions in experimental data [123-127, 135]. In these experiments, a series of odd harmonics was applied from which every third or fourth frequency was removed. They were 1, 3, 9, 11, 15, 17, 21... or 3, 5, 7,11, 15, 17, 19, 21, 25... This method was applied to study organic coatings on A1 [125], The signal contained frequencies between 0.1 Hz and... 

FT-based measurements allow for faster measurements because all the frequencies are applied at the same time, and to carry out impedance measurements during the potential sweep, it is assumed that the changes during the data block used for transformation are negligible (pseudostationary). FT-based measurements also permit one to determine time variance and nonlinear distortions in the data. However, the cost of this convenience is a lower amplitude for each frequency compared to classical EIS. This produces a weaker signal and larger noise. The interest in this method is constantly increasing. 

Considering the first reaction, A + B = C, separately, the thermodynamic time variance is... 

Irreversible transduction nodes An irreversible transduction node is a resistive node with true power ports with one additional power port of which the flow is equal to the entropy production function of the resistive node. Consequently the conjugate effort equals the power of this port divided by the entropy production function and is called temperature. This illustrates the nonlinear nature of its constitutive relations, such that the earlier conclusion that linear, time-(in)variant transducers are reversible is not violated. Node label RS. In case of modulation (time variance of the entropy production function) MRS. Note that an (M)RS is an extension of an (M)R and when discussing port-based modeling, it will turn out that the (M)R rather is a special case of an (M)RS which is the result of a modeling assumption (constant temperature or irrelevance of temperature changes) that remains often implicit. 

Gajpal, Y. Rajendran, C. (2006). An ant-colony optimization algorithm for minimizing the completion-time variance of jobs in flowshop. International Journal of Production Economics, Vol. 101, No. 2, pp.259-272. 

Although some circuits, and particularly electromechanical networks, are purposely designed to exhibit time-varying volt-ampere characteristics, parametric time variance is generally viewed as a parasitic phenomenon in the majority of practical circuits. Unfortunately, a degree of parametric time variance is unavoidable in even those circuits that are specifically designed to achieve input/output response properties that closely approximate time-invariant characteristics. For example, the best of network elements exhibit a slow aging phenomenon that shifts the values of its intrinsic physical parameters. The upshot of these shifts is electrical circuits the overall performance of which deteriorates with time. 

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