563 research outputs found
Diverging business strategies towards climate change : a USA-Europe comparison for four sectors of industry
The research project has investigated what strategies specific sectors of industry develop to limit greenhouse gas emissions. In an USA-Europe co-operation, researchers have analysed emerging climate strategies in the oil industry, the automobile industry, the chemical industry and the bank and insurance sector. These sectors are the most important players in the climate policy debate. Special attention has been paid to the questions whether strategies of EU based corporations differ systematically from USA based corporations. Results show rather sectorial specific developments. In most sectors, i.e. oil, automobile and banks, European corporations generally tend to have more advanced policies than their USA counterparts, but this does not
apply to chemical companies. Corporate strategies appear to be highly determined by a combination of market situation in the home country and of access to alternative technologies. Objective of the study was to provide information of relevance to the COP (Sixth Session of the UNFCCC Conference of the Parties) 2000 conference, November 2000 in The Hague
Inversion of displacement fields to quantify the magnetic particle distribution in homogeneous elastic media from magnetomotive ultrasound
Magnetomotive ultrasound (MMUS) contrasts superparamagnetic iron-oxide nanoparticles (SPIOs) that undergo submicrometer-scale displacements in response to a magnetic gradient force applied to an imaging sample. Typically, MMUS signals are defined in a way that is proportional to the medium displacement, rendering an indirect measure of the density distribution of SPIOs embedded within. Displacement-based MMUS, however, suffers from 'halo effects' that extend into regions without SPIOs due to their inherent mechanical coupling with the medium. To reduce such effects and to provide a more accurate representation of the SPIO density distribution, we propose a model-based inversion of MMUS displacement fields by reconstructing the body force distribution. Displacement fields are modelled using the static Navier-Cauchy equation for linear, homogeneous, and isotropic media, and the body force fields are, in turn, reconstructed by minimizing a regularized least-squares error functional between the modelled and the measured displacement fields. This reconstruction, when performed on displacement fields of two tissue-mimicking phantoms with cuboidal SPIO-laden inclusions, improved the range of errors in measured heights and widths of the inclusions from 54%-282% pre-inversion to-15%-20%. Likewise, the post-inversion contrast to noise ratios (CNRs) of the images were significantly larger than displacement-derived CNRs alone (p = 0.0078, Wilcoxon signed rank test). Qualitatively, it was found that inversion ameliorates halo effects and increases overall detectability of the inclusion. These findings highlight the utility of model-based inversion as a tool for both signal processing and accurate characterization of the number density distribution of SPIOs in magnetomotive imaging
Extracting Spooky-activation-at-a-distance from Considerations of Entanglement
Following an early claim by Nelson & McEvoy \cite{Nelson:McEvoy:2007}
suggesting that word associations can display `spooky action at a distance
behaviour', a serious investigation of the potentially quantum nature of such
associations is currently underway. This paper presents a simple quantum model
of a word association system. It is shown that a quantum model of word
entanglement can recover aspects of both the Spreading Activation equation and
the Spooky-activation-at-a-distance equation, both of which are used to model
the activation level of words in human memory.Comment: 13 pages, 2 figures; To appear in Proceedings of the Third Quantum
Interaction Symposium, Lecture Notes in Artificial Intelligence, vol 5494,
Springer, 200
Proof Explanation in the DR-DEVICE System
Trust is a vital feature for Semantic Web: If users (humans and agents) are to use and integrate system answers, they must trust them. Thus, systems should be able to explain their actions, sources, and beliefs, and this issue is the topic of the proof layer in the design of the Semantic Web. This paper presents the design and implementation of a system for proof explanation on the Semantic Web, based on defeasible reasoning. The basis of this work is the DR-DEVICE system that is extended to handle proofs. A critical aspect is the representation of proofs in an XML language, which is achieved by a RuleML language extension
Application of Bayesian statistics to estimate nitrous oxide emission factors of the nitrogen fertilisers in UK grasslands
Trapezoidal integration by linear interpolation of data points is by far the most commonly used method of
cumulative flux calculations of nitrous oxide (N2O) in studies that use flux chambers; however, this method is
incapable of providing accurate uncertainty estimates. A Bayesian approach was used to calculate N2O emission
factors (EFs) and their associated uncertainties from flux chamber measurements made after the application of
nitrogen fertilisers, in the form of ammonium nitrate (AN), urea (Ur) and urea treated with Agrotain® urease
inhibitor (UI) at four grassland sites in the UK. The comparison between the cumulative fluxes estimated using
the Bayesian and linear interpolation methods were broadly similar (R2=0.79); however, the Bayesian method
was capable of providing realistic uncertainties when a limited number of data points is available. The study
reports mean EF values (and 95% confidence intervals) of 0.60 ± 0.63, 0.29 ± 0.22 and 0.26 ± 0.17% of
applied N emitted as N2O for the AN, Ur and UI treatments, respectively. There was no significant difference
between N2O emissions from the Ur and UI treatments. In the case of the automatic chamber data collected at
one site in this study, the data did not fit the log-normal model, implying that more complex models may be
needed, particularly for measurement data with high temporal resolutioninfo:eu-repo/semantics/publishedVersio
Spin dependent scattering of a domain-wall of controlled size
Magnetoresistance measurements in the CPP geometry have been performed on
single electrodeposited Co nanowires exchange biased on one side by a sputtered
amorphous GdCo layer. This geometry allows the stabilization of a single domain
wall in the Co wire, the thickness of which can be controlled by an external
magnetic field. Comparing magnetization, resistivity, and magnetoresistance
studies of single Co nanowires, of GdCo layers, and of the coupled system,
gives evidence for an additional contribution to the magnetoresistance when the
domain wall is compressed by a magnetic field. This contribution is interpreted
as the spin dependent scattering within the domain wall when the wall thickness
becomes smaller than the spin diffusion length.Comment: 9 pages, 13 figure
Variable Ticket Pricing in Major League Baseball
Sport teams historically have been reluctant to change ticket prices during the season. Recently, however, numerous sport organizations have implemented variable ticket pricing in an effort to maximize revenues. In Major League Baseball variable pricing results in ticket price increases or decreases depending on factors such as quality of the opponent, day of the week, month of the year, and for special events such as opening day, Memorial Day, and Independence Day. Using censored regression and elasticity analysis, this article demonstrates that variable pricing would have yielded approximately 1.4 million in revenue. The largest percentage revenue gain would have been the San Francisco Giants. The Giants would have seen an estimated 6.7% increase in revenue had they used optimal variable pricing
The Contested Politics of Corporate Governance: The Case of the Global Reporting Initiative
The Global Reporting Initiative (GRI) has successfully become institutionalized as the preeminent global framework for voluntary corporate environmental and social reporting. Its success can be attributed to the “institutional entrepreneurs” who analyzed the reporting field and deployed discursive, material, and organizational strategies to change it. GRI has, however, fallen short of the aspirations of its founders to use disclosure to empower nongovernmental organizations (NGOs). The authors argue that its trajectory reflects the power relations between members of the field, their strategic choices and compromises, their ability to mobilize alliances and resources, and constraints imposed by the broader institutions of financial and capital markets. The authors draw three notable implications from this study. First, institutional theory needs to pay more attention to economic structures, strategies, and resources. Second, institutional entrepreneurship by relatively weak societal groups such as NGOs is inherently constrained by the structural power of wider institutions and by the compromises required to initiate change. Third, the strategies of NGOs represent a form of power capable of shifting, if not transforming, the field of corporate governance
Transport properties of strongly correlated metals:a dynamical mean-field approach
The temperature dependence of the transport properties of the metallic phase
of a frustrated Hubbard model on the hypercubic lattice at half-filling are
calculated. Dynamical mean-field theory, which maps the Hubbard model onto a
single impurity Anderson model that is solved self-consistently, and becomes
exact in the limit of large dimensionality, is used. As the temperature
increases there is a smooth crossover from coherent Fermi liquid excitations at
low temperatures to incoherent excitations at high temperatures. This crossover
leads to a non-monotonic temperature dependence for the resistance,
thermopower, and Hall coefficient, unlike in conventional metals. The
resistance smoothly increases from a quadratic temperature dependence at low
temperatures to large values which can exceed the Mott-Ioffe-Regel value, hbar
a/e^2 (where "a" is a lattice constant) associated with mean-free paths less
than a lattice constant. Further signatures of the thermal destruction of
quasiparticle excitations are a peak in the thermopower and the absence of a
Drude peak in the optical conductivity. The results presented here are relevant
to a wide range of strongly correlated metals, including transition metal
oxides, strontium ruthenates, and organic metals.Comment: 19 pages, 9 eps figure
The relationship between levels of education of entrepreneurs and their business success: A study of the province of KwaZulu-Natal, South Africa
The small, medium and micro enterprise (SMME) sector has been widely recognized as an engine of economic growth in South Africa. The implementation of the National Small Business Strategy (NSBS) in 1995 established important objectives for the sector to address such problems as lack of access to markets and procurement, lack of access to finance and credit, low skills and education levels, lack of access to information and a shortage of effective support institutions. In response, the South African government established institutions and programmes designed to improve access to sources of finance, market opportunities, technology, training and development and education. This paper examines whether there is a relationship between the level of education of SMME owners and the growth of their businesses, using labour force and turnover as success indicators. The study adopted a mixed method approach, including questionnaire surveys, observations and face-to-face interviews. The results indicate that in the two years preceding the study there had been a relationship between the owner/manager's level of education and the business's ability to grow by increasing its labour force and annual turnover. This study, conducted in a developing economy, therefore supports the findings of similar studies in developed economies, that the level of education of an entrepreneur and the success of their business are related
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