The Case for Modeling Correlation in Manufacturing Systems

Manufacturing-related models have traditionally made independence assumptions on associated stochastic processes in order to achieve tractability of analytical models and simplify Monte Carlo models. This paper aims to alert users to potential deleterious implications stemming from unfounded independence assumptions in traditional stochastic models of manufacturing systems. Specifically, it demonstrates the dramatic impact that appreciable autocorrelations can have on manufacturing performance measures through a preliminary study of prediction errors incurred in ignoring dependence. To this end, the study compared performance measures of common manufacturing models with renewal components to their autocorrelated counterparts, drawn from the TES (Transform-Expand-Sample) class. TES models constitute a versatile class of stochastic processes, designed to capture empirical distributions and autocorrelations, simultaneously, and as such, are suitable for both Monte Carlo simulation and analytical modeling of autocorrelated time series. A brief overview of simple TES processes and their generation algorithms is also included.     

A research methodology for evaluating location aware experiences

Research field trials of fully functional prototypes of location-based games are an effective way to test game designs and develop an understanding of what makes games compelling. They may also expose emergent behaviors or facets of the game which were not predicted in the design. Experiments are a good way to explore these emergent behaviors in a rigorous way. We describe an emergence-driven research methodology that formalizes this process of using emergent phenomena from research field trials to drive experiments. We also describe a range of techniques that can be used to evaluate location aware experiences.     

Short-term beneficial effect of deprenyl monotherapy in early Parkinson''s disease: a quantitative assessment

We report a case of giant ectopic pelvic spleen combined with an accessory spleen and confirmed by liver-spleen scan, angiography, magnetic resonance imaging, and surgical findings. In various reviews of the literature, no ectopic pelvic spleen larger than this one has been reported.     

Analysis of the nonuniformity of the velocity fields in chemical reactors of different geometries

The effect of the shape of an apparatus and the flow pattern in it on the nonuniformity of the velocity field is studied. A criterion for comparing the nonuniformity of hydrodynamic fields is proposed. It is shown that the nonuniformity can be analyzed using the simplest hydrodynamic model without parameters—the model of potential flow of an inviscid incompressible liquid.     

Antibodies from ALS patients inhibit dopamine release mediated by L-type calcium channels

From the studies analysed as well as based on our own experience, induction therapy mainly with polyclonal cytolytic agents represents a helpful tool in the individualised immunosuppressive approach, whereas monoclonal induction therapies have to be discussed carefully. Although transplantation is also feasible without cytolytic agents, certain patients at risk will further encourage the need for this valuable therapy also in the future, where new immunosuppressants are available. However, it is anticipated that the application should be conducted on an individual patient basis to achieve optimal individual benefit.     

Has the health profile and pregnant Ethiopian immigrants changed in the Ashkelon region in the past years?]

There are about 6500 births yearly in the Ashkelon District. 6% of the mothers are Ethiopians, most of whom immigrated to Israel since the early 90's. Our data are from 3 sources: birth certificates, infant death certificates, and the national population register. Birth rates in single mothers and rates of low-birth-weight births have declined over the years. Infant mortality and still-birth rates have also shown remarkable and consistent declines between 1990-1995. We conclude that improvement in life conditions of Ethiopian immigrants and better use of health services have had a great impact on birth outcomes and pregnancy patterns. The gap between Ethiopian immigrants and other Jewish communities in Israel is closing fast.     

Participation of a PGU-325 in frequency primary control

Engineering features of the main machinery for a PGU-325 power generating unit of plant no. 2 of the Ivanovskie combined cycle plants (CCPs) are given. Based on the results of preliminary tests, the upper and lower limits of the operating load range are chosen for tests of the PGU-325 on the compliance to the general frequency primary control standard of the System Operator (SO) of the Unified Power System (UPS). For the effective participation of a vapor turbine in the frequency primary control, an operating point for the control valve opening is chosen. Tests are performed at the imitation of frequency errors of ±300 mHz from a nominal value that cause a power generating unit variation of ±10% of nominal at a degree of irregularity of 6%. Tests showed that the power generating unit equipped by engineers of the automatic process control system of Interavtomatika met the requirements of the SO to dynamics of primary power generation and may render corresponding system services.     

Elevated burnout predicts the onset of musculoskeletal pain among apparently healthy employees.

Musculoskeletal (MS) pain is highly prevalent in the working population, often resulting in chronic disability. Burnout represents accumulated exposure to work-related stresses and therefore could predict the incidence of MS pain. We investigated prospectively the extent to which changes in the levels of burnout over time predict new cases of MS pain. Participants were 1,704 apparently healthy employed men and women who underwent periodic health examination at three points of time (T1, T2, and T3), over a period of about three years. We used the T1 to T2 changes in the levels of burnout, depressive symptoms, and anxiety to predict the onset of new cases of MS pain between T2 and T3, while controlling for possible confounders. Logistic regression results indicated that the T1–T2 change in burnout levels was associated with a 2.09-fold increased risk of MS pain (95% confidence interval = 1.07–4.10). No support was found for the possibility of reverse causation; that is, that MS pain predicts subsequent elevations of burnout levels. It was concluded that burnout might be a risk factor in the development of MS pain in apparently healthy individuals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Local spectral analysis of short-pulse excited scattering fromweakly inhomogeneous media. I. Forward scattering

In this two-part sequence, we extend a previously formulated pulsed plane wave (PPW)-based time-domain (TD) diffraction tomography for forward and inverse scattering from weakly inhomogeneous lossless nondispersive media to a more highly localized pulsed beam (PB) wavepacket-based diffraction tomography. In the PPW version, the incident and scattered fields have been parameterized in the space-time wavenumber domain in terms of slant-stacked TD plane waves whose wavefronts move through the scattering medium at the ambient propagation speed, thereby accumulating information along time-resolved laterally extended planar cuts. The PB parameterized localization confines the laterally sampled regions to the spatial domains of influence transverse to the relevant beam axes. These localizations are performed in two stages. The present paper implements the PB parameterization by PB post processing of the forward scattered fields excited by an incident PPW; the companion paper (Part 2, see ibid., vol.47, no.7, p.1218-27, July 1999) deals with the inverse problem by back propagation of the PB parameterized data. An “ultimate” localization of a space-time resolved scattering cell is also briefly summarized in Part 2