Operating efficiency of computers

A method is outlined which can be used to guarantee to users of computing systems a measure of operating efficiency. The monthly utilization coefficient should be equal to or exceed a value agreed on in advance. In addition, the repair time during a computer breakdown should not be longer than a period agreed on in advance

How Responsive Are EU Coal-Burning Plants to Changes in Energy Prices?

The European Union (EU) Emissions Trading System (ETS) has implicitly made it more expensive to burn coal relative to natural gas because coal has a higher carbon content. Therefore, it is important to understand how much plants reduce their coal usage in response to higher coal prices to assess the effectiveness of the ETS in reducing carbon emissions. We analyze a novel panel of coal-burning large combustion plants from a subsample of eight EU countries and found that, holding constant the natural gas price, a 1% increase in the coal price results in a 0.36% decrease in coal consumption. At current ETS prices, this implies that the average large combustion plant in our sample EU countries is burning 7% less coal than it would be absent in the ETS. This suggests that the ETS has significantly reduced carbon emissions from coal-fired plants for the eight countries represented in our sample

Environmental Performance of State-Owned and Privatized Eastern European Energy Utilities

Privatization in Eastern Europe has helped in the transition of the region\u27s economies from planned to free market. However, the effects of privatization on the environment are relatively unknown and many firms remain under state ownership today. We compare the environmental performance of state-owned and privatized energy utility plants in Eastern Europe utilizing a novel panel data that includes reported sulfur dioxide emissions, energy input, and ownership status. We find that state-owned plants emit more sulfur dioxide than privately owned plants; this is environmentally significant as privatization is associated with a reduction in emissions of about 55%

Analyzing the Characteristics of Plants Choosing to Opt-Out of the Large Combustion Plant Directive

The EU Large Combustion Plant Directive (LCPD) is a major but largely unstudied environmental regulation. Most of the 1585 large combustion plants in this analysis are electricity supply plants or combined heat and power plants. We find that, controlling for country characteristics and plant size, plants in the electricity supply, combined heat and power, district heating, and paper industries have a higher probability of being opted-out of the emission limit values (ELVs), which necessitates eventual plant closure. Controlling for plant size and industry, increasing the amount of solid fuel or natural gas utilized at a plant is associated with a decreased likelihood of being opted-out of the ELVs

Literature-based priors for gene regulatory networks

Motivation: The use of prior knowledge to improve gene regulatory network modelling has often been proposed. In this paper we present the first research on the massive incorporation of prior knowledge from literature for Bayesian network learning of gene networks. As the publication rate of scientific papers grows, updating online databases, which have been proposed as potential prior knowledge in past rese-arch, becomes increasingly challenging. The novelty of our approach lies in the use of gene-pair association scores that describe the over-lap in the contexts in which the genes are mentioned, generated from a large database of scientific literature, harnessing the information contained in a huge number of documents into a simple, clear format. Results: We present a method to transform such literature-based gene association scores to network prior probabilities, and apply it to learn gene sub-networks for yeast, E. coli and Human organisms. We also investigate the effect of weighting the influence of the prior know-ledge. Our findings show that literature-based priors can improve both the number of true regulatory interactions present in the network and the accuracy of expression value prediction on genes, in comparison to a network learnt solely from expression data. Networks learnt with priors also show an improved biological interpretation, with identified subnetworks that coincide with known biological pathways. Contact

Porometry, porosimetry, image analysis and void network modelling in the study of the pore-level properties of filters

We present fundamental and quantitative comparisons between the techniques of porometry (or flow permporometry), porosimetry, image analysis and void network modelling for seven types of filter, chosen to encompass the range of simple to complex void structure. They were metal, cellulose and glass fibre macro- and meso-porous filters of various types. The comparisons allow a general re-appraisal of the limitations of each technique for measuring void structures. Porometry is shown to give unrealistically narrow void size distributions, but the correct filtration characteristic when calibrated. Shielded mercury porosimetry can give the quaternary (sample-level anisotropic) characteristics of the void structure. The first derivative of a mercury porosimetry intrusion curve is shown to underestimate the large number of voids, but this error can be largely corrected by the use of a void network model. The model was also used to simulate the full filtration characteristic of each sample, which agreed with the manufacturer's filtration ratings. The model was validated through its correct a priori simulation of absolute gas permeabilities for track etch, cellulose nitrate and sintered powder filters. © 2011 Elsevier Ltd

Mean semi-deviation from a target and robust portfolio choice under distribution and mean return ambiguity

Cataloged from PDF version of article.We consider the problem of optimal portfolio choice using the lower partial moments risk measure for a market consisting of n risky assets and a riskless asset. For when the mean return vector and variance/covariance matrix of the risky assets are specified without specifying a return distribution, we derive distributionally robust portfolio rules. We then address potential uncertainty (ambiguity) in the mean return vector as well, in addition to distribution ambiguity, and derive a closed-form portfolio rule for when the uncertainty in the return vector is modelled via an ellipsoidal uncertainty set. Our result also indicates a choice criterion for the radius of ambiguity of the ellipsoid. Using the adjustable robustness paradigm we extend the single-period results to multiple periods, and derive closed-form dynamic portfolio policies which mimic closely the single-period policy. © 2013 Elsevier B.V. All rights reserved

Utility of geometry in lattice QCD simulations

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Make a choice or the choice makes you! Een onderzoek naar de invloed van risicobereidheid op de relatie tussen persoonlijkheid en duurzame inzetbaarheid

Many employers are concerned about the employability of their employees. Most employers are therefore busy with the development of employability. But they also are confronted with a big challenge in stimulating responsibility of employees themselves in relation to their own employability. The extent to which employability is directly related to the choices employees make. This research is focused on the question "What is the relation between personality and employbility and what is the impact of risk propensity on this relation?" In order to answer this question we first exam the possible direct relation between personality and employability, between personality and risk propensity and between risk propensity and employability. Then this research explores the extent to which risk propensity has a moderating of mediating effect in the relation between personality and employability. Based on existing literature hypotheses are tested by quantitative research methods. The research population consists of employees of an organization in the financial sector. They were invited to fill in an questionnaire (N=146), which served as data gathering method. The results show that the Big Five personality traits only Neuroticism has a significant correlation with employability. More specifically, it refers to a negative relation. Furthermore, a significant relation between the four other Big Five personality traits Openness (positive), Conscientiousness (negative), Extraversion (negative) and Altruism (negative) and risk propensity was found. No moderation effect of risk propensity on the relation between personality and employability was found. This also applies to the mediation effect. This study has therefore shown that the extent to which employees are willing to take risk or avoid risk has impact on their own employability, but no impact in the relationship between personality and employability. Finally we conclue that Neuroticism is important for employees and needs to be further explored by organizations for more practical interventions

Robust portfolio choice with CVaR and VaR under distribution and mean return ambiguity

Cataloged from PDF version of article.We consider the problem of optimal portfolio choice using the Conditional Value-at-Risk (CVaR) and Value-at-Risk (VaR) measures for a market consisting of n risky assets and a riskless asset and where short positions are allowed. When the distribution of returns of risky assets is unknown but the mean return vector and variance/covariance matrix of the risky assets are fixed, we derive the distributionally robust portfolio rules. Then, we address uncertainty (ambiguity) in the mean return vector in addition to distribution ambiguity, and derive the optimal portfolio rules when the uncertainty in the return vector is modeled via an ellipsoidal uncertainty set. In the presence of a riskless asset, the robust CVaR and VaR measures, coupled with a minimum mean return constraint, yield simple, mean-variance efficient optimal portfolio rules. In a market without the riskless asset, we obtain a closed-form portfolio rule that generalizes earlier results, without a minimum mean return restriction