Including design in e-manufacturing

This paper reviews major issues in the implementation of e-manufacturing, particularly the design aspects. It will examine recent progress, drawing out particular issues that are being addressed. Use will be made of the work by the author and colleagues to devise rule-based design and Internet-based control of machines to illustrate how these developments affect the integrated e-manufacturing environment. A dynamic Simulink model of the way e-manufacture is affected by overall design delays is used to evaluate general solutions for partial and complete e-based companies. These models show how changing to improved designs reduces WI

Inventory control systems model for strategic capacity acquisition

Variation of installed industrial capacity has been found to follow a cyclic pattern. This paper discusses the application of control theory to the problem of the timely acquisition of extra production capacity. The control system based model presented here is compared with a System Dynamics model proposed by Sterman. Key differences are the method of implementing rational decisions about deployment of extra capacity and the use of a nonlinear APVIOBPCS inventory model. Benefits of this new model are a more measurable process and the ability to select parameter values to optimise capacity deployment. Simulation of the model indicates that the results found by Sterman underestimate the production backlog and time taken to reach equilibrium. The use of a Proportional, Integral, and Derivative (PID) controller in the capacity control loop model illustrates that it is possible not only to alter the backlog levels but at the same time to reduce the sales force and improve the revenue. The model also shows clearly that the impact of not increasing capacity promptly results in catastrophic failure of sales as a structural, rather than a business, problem. This model is simple enough to be implemented as a spreadsheet for use as a guide by managers

MicroR159 regulation of most conserved targets in Arabidopsis has negligible phenotypic effects

BACKGROUND A current challenge of microRNA (miRNA) research is the identification of biologically relevant miRNA:target gene relationships. In plants, high miRNA:target gene complementarity has enabled accurate target predictions, and slicing of target mRNAs has facilitated target validation through rapid amplification of 5' cDNA ends (5'-RACE) analysis. Together, these approaches have identified more than 20 targets potentially regulated by the deeply conserved miR159 family in Arabidopsis, including eight MYB genes with highly conserved miR159 target sites. However, genetic analysis has revealed the functional specificity of the major family members, miR159a and miR159b is limited to only two targets, MYB33 and MYB65. Here, we examine the functional role of miR159 regulation for the other potential MYB target genes. RESULTS For these target genes, functional analysis failed to identify miR159 regulation that resulted in any major phenotypic impact, either at the morphological or molecular level. This appears to be mainly due to the quiescent nature of the remaining family member, MIR159c. Although its expression overlaps in a temporal and spatial cell-specific manner with a subset of these targets in anthers, the abundance of miR159c is extremely low and concomitantly a mir159c mutant displays no anther defects. Examination of potential miR159c targets with conserved miR159 binding sites found neither their spatial or temporal expression domains appeared miR159 regulated, despite the detection of miR159-guided cleavage products by 5'-RACE. Moreover, expression of a miR159-resistant target (mMYB101) resulted predominantly in plants that are indistinguishable from wild type. Plants that displayed altered morphological phenotypes were found to be ectopically expressing the mMYB101 transgene, and hence were misrepresentative of the in vivo functional role of miR159. CONCLUSIONS This study presents a novel explanation for a paradox common to plant and animal miRNA systems, where among many potential miRNA-target relationships usually only a few appear physiologically relevant. The identification of a quiescent miR159c:target gene regulatory module in anthers provides a likely rationale for the presence of conserved miR159 binding sites in many targets for which miR159 regulation has no obvious functional role. Remnants from the demise of such modules may lead to an overestimation of miRNA regulatory complexity when investigated using bioinformatic, 5'-RACE or transgenic approaches.RSA was funded by an ANU postgraduate scholarship and by a CSIRO Emerging Science Initiative. JL is the recipient of an ANU international student postgraduate scholarship. This research was supported by an Australian Research Council grant DP0773270

Introduction to the special issue : historical and projected climatic changes to Australian natural hazards

Australia’s size and varied climates mean that it is affected by a range of weather-related natural hazards, including tropical and extra-tropical storms and associated extreme wind and hail, coastal and inland floods, heatwaves and bushfires. These hazards cause multiple human and environmental impacts, and collectively account for 93 % of Australian insured losses (Schuster 2013). In addition, drought—often treated distinctly from other hazards due to its more gradual onset—can cause substantial reductions in agricultural productivity, and places stress on municipal and industrial water resources and natural ecosystems. Evidence is building that the frequency and cost of natural hazards are increasing both in Australia (Insurance Council of Australia 2013; Schuster 2013) and globally (Munich Re 2014). However, understanding the cause of these changes has proved to be difficult, with increases in reporting rates (Munich Re 2014), changes in societal exposure and vulnerability (Bouwer 2011; Neumayer and Barthel 2011) and anthropogenic climate change (IPCC 2013) all potentially playing a role in explaining the observed changes. Yet although the potential causes are many, correct attribution of the observed changes is necessary in order to identify appropriate policy responses, and to predict how the frequency and severity of natural hazards might change in the future. This Special Issue focuses on the specific role of large-scale climatic changes on the observed and future incidence of Australian natural hazards. The Special Issue is divided into seven papers, each covering a major class of climate-influenced natural hazard: floods, drought, storms (including wind and hail), coastal extremes, bushfires, heatwaves and frost. The work was initiated by the Working Group on Trends and Extremes from the Australian Water and Energy Exchanges (OzEWEX) initiative, which is a regional hydroclimate project run under the auspices of the Global Energy and Water Exchanges (GEWEX) initiative

Lensed CMB power spectra from all-sky correlation functions

Weak lensing of the CMB changes the unlensed temperature anisotropy and polarization power spectra. Accounting for the lensing effect will be crucial to obtain accurate parameter constraints from sensitive CMB observations. Methods for computing the lensed power spectra using a low-order perturbative expansion are not good enough for percent-level accuracy. Non-perturbative flat-sky methods are more accurate, but curvature effects change the spectra at the 0.3-1% level. We describe a new, accurate and fast, full-sky correlation-function method for computing the lensing effect on CMB power spectra to better than 0.1% at l<2500 (within the approximation that the lensing potential is linear and Gaussian). We also discuss the effect of non-linear evolution of the gravitational potential on the lensed power spectra. Our fast numerical code is publicly available.Comment: 16 pages, 4 figures. Changes to match PRD version including new section on non-linear corrections. CAMB code available at http://camb.info

Measurement of Dielectric Suppression of Bremsstrahlung

In 1953, Ter-Mikaelian predicted that the bremsstrahlung of low energy photons in a medium is suppressed because of interactions between the produced photon and the electrons in the medium. This suppression occurs because the emission takes place over on a long distance scale, allowing for destructive interference between different instantaneous photon emission amplitudes. We present here measurements of bremsstrahlung cross sections of 200 keV to 20 MeV photons produced by 8 and 25 GeV electrons in carbon and gold targets. Our data shows that dielectric suppression occurs at the predicted level, reducing the cross section up to 75 percent in our data.Comment: 11 pages, format is postscript file, gzip-ed, uuencode-e