21,683 research outputs found
Turbocharger speed monitoring based on vibration measurements for diesel engine management
No full textA Systematic Review of Industry 4.0 Maturity Models: Applicability in the O&G Upstream Industry
No full textThe study aims to review the currently available Industry 4.0 (I4.0) maturity models (MMs) for manufacturing industries and analyse their applicability in the oil and gas (O&G) upstream sector. Knowing that the growth in demand for energy through crude oil and natural gas is still viable over the next decade, there is the drive to ensure sustenance and improvement in production. The study sees an opportunity in harnessing the gains of Industry 4.0 technologies for better solution-driven strategies in production processes, equipment availability and reliability which would translate into higher production performance. So, a review on the Industry 4.0 MMs is considered important. A systematic and in-depth literature review was performed to identify the specific requirements of this industry. This study examined the key characteristics of the O&G upstream sector and identified research gaps that need to be addressed to successfully support this industry for Industry 4.0 implementation. An Industry 4.0 MM that reflects the industrial realities for this industry more accurately from insights drawn from reviews of existing MMs is proposed. The review of 19 selected Industry 4.0 MMs revealed that the existing MMs are not a direct fit for the O&G upstream industry. Only a few of the models were clear on validation but with subjectivity, low number of persons and industries involved as limitations; none of the models confirmed validation with the O&G industry. There are varying views on the model dimensions and maturity levels by each author and not all required areas specific to the O&G industries were acknowledged by the models. An MM specific to this industry is therefore required. Although the journey of digitisation has commenced in the O&G industry, a reduction with the challenges of transition towards Industry 4.0 implementation and provision of support for improved efficiency is assured using a robust MM, as proposed in this paper
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
O. Henry reviews his writing techniques
No full textAmerican author William Sydney Porter, better known by his pen name "O. Henry," reviews his writing techniques
Resourcefulness quantification approach for resilient communities and countries
No full textAvailability of resources is one of the primary criteria for communities to attain a high resilience level during disaster events. This paper introduces a new approach to evaluate resourcefulness at the community and national scales. Resourcefulness is calculated using a proposed composite resourcefulness index, which is a combination of several resourcefulness indicators. To build the resourcefulness index, resourcefulness indicators representing the different aspects of resourcefulness are collected from renowned literary publications. Every indicator is assigned a measure to make it quantifiable. Time-history data for the measures are needed to perform the analysis. While these data could be obtained from different sources, acquiring a full set of data is quite challenging. Hence, to account for missing data, the Multiple Imputation (MI) and the Markov Chain Monte Carlo (MCMC) data imputation methods are adopted. The data are then normalized, assigned weights, and aggregated to obtain the resourcefulness index. A case study is performed to demonstrate the applicability of the approach. The resourcefulness indexes of two countries, namely the United States and Italy, are evaluated. Results show that resourceful communities/countries are more resilient during disaster events as they have more tools to come up with solutions. It is also shown that knowing the current resourcefulness level helps in better identifying what aspects should be improved.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Integral Design & Managemen
Cooling rates of neutron stars and the young neutron star in the Cassiopeia A supernova remnant
No full textWe explore the thermal state of the neutron star in the Cassiopeia A supernova remnant using the recent result of Ho & Heinke that the thermal radiation of this star is well described by a carbon atmosphere model and the emission comes from the entire stellar surface. Starting from neutron star cooling theory, we formulate a robust method to extract neutrino cooling rates of thermally relaxed stars at the neutrino cooling stage from observations of thermal surface radiation. We show how to compare these rates with the rates of standard candles – stars with non-superfluid nucleon cores cooling slowly via the modified Urca process. We find that the internal temperature of standard candles is a well-defined function of the stellar compactness parameter x=rg/R, irrespective of the equation of state of neutron star matter (R and rg are circumferential and gravitational radii, respectively). We demonstrate that the data on the Cassiopeia A neutron star can be explained in terms of three parameters: f?, the neutrino cooling efficiency with respect to the standard candle; the compactness x; and the amount of light elements in the heat-blanketing envelope. For an ordinary (iron) heat-blanketing envelope or a low-mass (? 10?13 M?) carbon envelope, we find the efficiency f?? 1 (standard cooling) for x? 0.5 and f?? 0.02 (slower cooling) for a maximum compactness x? 0.7. A heat blanket containing the maximum mass (?10?8 M?) of light elements increases f? by a factor of 50. We also examine the (unlikely) possibility that the star is still thermally non-relaxe
Probabilistic framework to evaluate the resilience of engineering systems using Bayesian and dynamic Bayesian networks
No full textResilience indicators are a convenient tool to assess the resilience of engineering systems. They are often used in preliminary designs or in the assessment of complex systems. This paper introduces a novel approach to assess the time-dependent resilience of engineering systems using resilience indicators. A Bayesian network (BN) approach is employed to handle the relationships among the indicators. BN is known for its capability of handling causal dependencies between different variables in probabilistic terms. However, the use of BN is limited to static systems that are in a state of equilibrium. Being at equilibrium is often not the case because most engineering systems are dynamic in nature as their performance fluctuates with time, especially after disturbing events (e.g. natural disasters). Therefore, the temporal dimension is tackled in this work using the Dynamic Bayesian Network (DBN). DBN extends the classical BN by adding the time dimension. It permits the interaction among variables at different time steps. It can be used to track the evolution of a system's performance given an evidence recorded at a previous time step. This allows predicting the resilience state of a system given its initial condition. A mathematical probabilistic framework based on the DBN is developed to model the resilience of dynamic engineering systems. Two illustrative examples are presented in the paper to demonstrate the applicability of the introduced framework. One example evaluates the resilience of Brazil. The other one evaluates the resilience of a transportation system.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Integral Design & Managemen
La polvere della memoria. Osservazioni sul libro di M. Stepanova "Pamjati pamjati"
No full textLa polvere della memoria. Osservazioni sul libro di M. Stepanova Pamjati pamjati
Il libro di M. Stepanova, Pamjati pamjati (2017), definito dai critici “il miglior romanzo russo degli ultimi anni”, è entrato dopo pochi giorni dalla sua pubblicazione nelle classifiche dei libri più ven-duti, dando grande notorietà a una poetessa e saggista, nota e apprezzata nei circoli intellettuali pro-gressisti. L’opera si basa sul desiderio dell’autrice di raccogliere e salvare i ricordi e le testimonian-ze dei propri cari sullo sfondo della grande storia. Metaromanzo, storia d’amore, resoconto di viag-gio, riflessione sulla fotografia o tutte queste cose insieme, in Pamjati pamjati, il fenomeno della memoria si sovrappone ad altri temi, diventa ampio e molteplice: la memoria e la storia, la memoria e la catastrofe, la memoria e il suono, la memoria e gli oggetti, la memoria e l’etica. L’autrice porta alla luce i suoi morti e sono loro che la aiuteranno a cambiare il suo linguaggio.
A scrivere quello che è in sostanza un necrologio alla memoria la aiuta uno degli autori che le sono più vicini, W. G. Sebald, i cui libri, a prescindere dal tema trattato, sono sempre scritti dalla parte dei morti. Partendo dall’idea di scrivere la storia della propria famiglia ebrea – russa – europea, composta da medici, architetti, bibliotecari, ragionieri e ingegneri che aspirano a condurre una vita tranquilla in un mondo violento e incivile, l’autrice tocca il problema della memoria del passato, dei piccoli e grandi avvenimenti del XX secolo, e di come essi possano sopravvivere nella memoria personale del singolo. L’ebraismo costituisce uno dei punti focali della narrazione, segna il destino dei personaggi anche se non tragicamente, perché quasi tutti riescono a sfuggire all’olocausto, al terrore staliniano. Non di meno la fragilità e l’insignificanza delle loro vite appaiono vulnerabili.
Diviso in tre parti, la prima di nove capitoli, la seconda di dieci e la terza di quattro, il libro mescola nelle prime due parti lettere di parenti, documenti, che conservano le loro voci. Intorno alle lettere, ci sono fotografie, oggetti quotidiani che l’autrice non si limita a descrivere al lettore, bensì mostra, trascrive, ingloba nel suo testo, perché ha sfiducia nelle immagini, nei selfi che pretendono di ripro-durre la vita senza riuscirci. La definizione “romance”, romanza, che leggiamo in copertina caratte-rizza perfettamente l’opera, tanto che alla fine Stepanova confessa a se stessa di aver dedicato il suo tempo non ad un’occupazione rispettabile, a una ricerca o a uno studio, bensì a un romanzo familia-re “freudiano”, a una “romanza sentimentale sul passato”.The Dust of Memory. A few remarks on M. Stepanova’s book Pamjati pamjati
The present article deals with M. Stepanova’s book Post-Memory published in 2017 with great suc-cess, a book which has no analogues not only in Russian but also in world literature. A meta-novel, a great literary reconstruction, which has created a whole new genre and sounds the relation be-tween memory, time, and history.
Stepanova had the idea of this writing at ten or eleven years. The project started as an exploration of how our memory works. When she started working on the book, she meant linear narrative —a sto-ry of search and finding. Go there, go here, find out, describe. It seemed her then that a large part of the hiatus and failures that have been family history will be easy to fill in accurate knowledge; but it turned out that the story is mostly from hiatus and is neither to find nor to make up for really any-thing. Only when she began to disassemble the family archive, she found, among other things, let-ters, photos, horoscopes, childhood souvenirs, things that the author examines in astonishment. Who were these people who travelled all throughout Europe yet lived in Russia? Who did their best to remain anonymous and who made little effort to make history seem interesting? But it is precise-ly the unspectacular nature of the find which turns the author’s research in the Russian context into something new: «Everyone else had a family made up of people participating in history; mine was made up only of their tenants». Destined to become victims of persecution and repression, they all still managed to survive the 20th century. How was that possible? This is the question and point of departure for Marija Stepanova’s first great work of prose.
In dialogue with W.G. Sebald, imbued with a passion for thought and a wonderfully soft, poetic voice derived from sensual as well as intellectual observations, Stepanova assembles her found pieces into a panorama of an entire age. At its heart lives a large family of doctors, architects, librar-ians, accountants, and engineers, unheroic individuals who did not attach themselves to any great project but who in uncivilized, violent times attempted to live quiet, civilized lives
Gushel–Mukai varieties with many symmetries and an explicit irrational Gushel–Mukai threefold
No full textWe construct an explicit smooth Fano complex threefold with Picard number 1, index 1, and degree 10 (also known as a Gushel–Mukai threefold) and prove that it is not rational by showing that its intermediate Jacobian has a faithful PSL(2,F11)-action. Along the way, we construct Gushel–Mukai varieties of various dimensions with rather large (finite) automorphism groups. The starting point of all these constructions is an Eisenbud–Popescu–Walter sextic with a faithful PSL(2,F11)-action discovered by the second author in 2013
Stenosemus exaratus G. O. Sars 1878
No full textStenosemus exaratus (G. O. Sars, 1878) Lophyrus exaratus G. O. Sars 1878: 113, pl. 8, figs 1 a–k. Kaas & Van Belle (1990) gave a bathymetric range for this species from 100 to 2580 m depth. Unfortunately the present author failed in getting a more precise citation for the abyssal record(s) of this species.Published as part of Schwabe, Enrico, 2008, A summary of reports of abyssal and hadal Monoplacophora and Polyplacophora (Mollusca) *, pp. 205-222 in Zootaxa 1866 on page 216, DOI: 10.5281/zenodo.18381
- …
