1,721,008 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Gas Turbine Operation - Drift av Gassturbiner
Full text linkImportant power and mechanical drive demands offshore are met by utilizing gas turbines. The safe and reliable operation of these fine-tuned thermo machines are of key importance to maintain platform operation. Problems related to challenging weather conditions and especially ice, are of real concern to engineers. Icing both precipitate and condensate are found to occur in gas turbines, and are only dealt with utilizing anti-icing measures, such as anti-icing systems and filters.
Anti-icing systems mostly used today comes with considerable costs to gas turbine efficiency, and prompts higher emissions to air. An extensive literature study of state-of-the-art anti-icing technologies have been conducted in this thesis. The operational impact the systems have on the gas turbine performance has been mapped. Waste heat recovery method of prevention has been documented to have a relatively small impact on operation. Analysing operational data from two LM2500PE gas turbines offshore confirms this notion. In the analysis the deviation in important performance parameters such as GG speed (N_1), and Pressure Ratio (PR), is more prominent in the gas turbine utilizing hot bleed extraction. The mass flow extraction is believed to be the cause of these deviation on performance parameters. The waste heat recovery system utilizes exhaust gas instead of compressor discharge air, as heat medium, which makes it the preferred system to install.
The hot bleed anti-icing system are documented to impact both compressor and gas turbine efficiencies. The deviations in polytropic compressor and thermal efficiency needs correcting. Correcting these efficiency trends will make diagnosing and detecting malfunctions easier. Polytropic efficiency was found to deviate due to altered N_1c and 〖PR〗_c. Thermal efficiency deviated because compressor delivery temperature (T_3c) was altered. A correction procedure was suggested and it proved promising as polytropic and thermal deviation was reduced from 3% to -1% and 2.4% to 0.4% for baseload, respectively. The part load running machines were corrected from 5.5% to 1% and 4.2% to 1.8% respectively
Gas Turbine Operation - Drift av Gassturbiner
No full textImportant power and mechanical drive demands offshore are met by utilizing gas turbines. The safe and reliable operation of these fine-tuned thermo machines are of key importance to maintain platform operation. Problems related to challenging weather conditions and especially ice, are of real concern to engineers. Icing both precipitate and condensate are found to occur in gas turbines, and are only dealt with utilizing anti-icing measures, such as anti-icing systems and filters.
Anti-icing systems mostly used today comes with considerable costs to gas turbine efficiency, and prompts higher emissions to air. An extensive literature study of state-of-the-art anti-icing technologies have been conducted in this thesis. The operational impact the systems have on the gas turbine performance has been mapped. Waste heat recovery method of prevention has been documented to have a relatively small impact on operation. Analysing operational data from two LM2500PE gas turbines offshore confirms this notion. In the analysis the deviation in important performance parameters such as GG speed (N_1), and Pressure Ratio (PR), is more prominent in the gas turbine utilizing hot bleed extraction. The mass flow extraction is believed to be the cause of these deviation on performance parameters. The waste heat recovery system utilizes exhaust gas instead of compressor discharge air, as heat medium, which makes it the preferred system to install.
The hot bleed anti-icing system are documented to impact both compressor and gas turbine efficiencies. The deviations in polytropic compressor and thermal efficiency needs correcting. Correcting these efficiency trends will make diagnosing and detecting malfunctions easier. Polytropic efficiency was found to deviate due to altered N_1c and 〖PR〗_c. Thermal efficiency deviated because compressor delivery temperature (T_3c) was altered. A correction procedure was suggested and it proved promising as polytropic and thermal deviation was reduced from 3% to -1% and 2.4% to 0.4% for baseload, respectively. The part load running machines were corrected from 5.5% to 1% and 4.2% to 1.8% respectively
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Bruk av heis til evakuering ved brann
No full textUtkastet til standard «prNS 3807:2019 Bruk av heis til evakuering» er utarbeidet med hensikt åetablere bestemmelser som kan benyttes for å bruke heis til evakuering av bygninger og anlegg,selv om byggteknisk forskrift (TEK17) angir at «Heis og rulletrapp kan ikke være del av fluktveieller rømningsvei. Slike innretninger skal stoppe på en sikker måte ved brannalarm». Det vises tilkrav til at økt tilgjengelighet, inkludert for personer med nedsatte funksjonsevner, medfører øktekrav til evakuering. Såkalte «sikre heissoner» skal bidra til at heiser skal kunne være i drift lengretid enn det som er tillatt i dag. RISE Fire Research har fått i oppdrag fra Direktoratet for byggkvalitet (DiBK) og Direktoratetfor samfunnssikkerhet og beredskap (DSB) å undersøke forutsetninger ved sikkerhetsbarrierer oghensyn til menneskelig adferd i prNS 3807:2019. Med utgangspunkt i oppdragsgivers spørsmål er noen usikkerhetsmomenter identifisert medhensyn til trygg bruk av heis ved brann i prNS 3807:2019. Noen er knyttet til vurdering av kriterierfor røykproduksjon og aktivisering av heisstopp. Brannskille i ventesone som oppfyller kriterieneangitt i prNS 3807:2019 vil ikke nødvendigvis forhindre røykspredning. Det er også usikkert hvorgodt de logiske heissonene, som er åpne og altså ikke er omgitt av noen skiller, ivaretarsikkerheten for personer som venter på en heis. Det angis ingen krav til minimumsstørrelse på fysisk heissone eller krav til plass forrullestolbrukere, noe som kan lede til at rømningsveier blir sperret og til opphopning av folk. Det er spesiell usikkerhet er knyttet til informasjon og kommunikasjon om evakueringen.Manglende krav til informativ talemelding kan bidra til at personer ikke forstår hva lyssignal ogtekst betyr, og dermed setter seg selv i fare. Det fremstår slik at sikkerheten i stor grad er avhengigav organisatoriske tiltak, noe som det i varierende grad kan legges til rette for avhengig av hvabygningen skal brukes til. Det kan være utfordrende å sikre at organisatoriske planer følges i langtid etter at de ble vedtatt i et brannkonsept, for eksempel siden aktiviteten og bruken av bygningenkan forandre seg over tid. Det stilles ikke krav om nærliggende alternative rømningsveier/trapp i anslutning til heis, dersomgitte barrierer blir brutt slik at ventesonen blir røykfylt og heisen stopper. Standarden legger kun opp til brukerstyring ved evakuering, dvs. det er brukerne selv somprioriterer hvem som kan ta heisen. Derfor ivaretas ikke nødvendigvis de som har størst behovfor rømning med heis. Sosiale bånd kan både forsinke og effektivisere en evakuering, avhengig av forholdene iforbindelse med alarmen (type bygning, aktivitet i bygningen, karakteristiske forhold vedbrannen, etc.) og menneskene som evakuerer (er de i slekt, kjenner de hverandre, andre faktorersom påvirker hvordan individer samhandler ved en hendelse). Med hensyn til å endre på innlært adferd (at man ikke skal ta heisen når alarmen går), vil detsannsynligvis kreves mye informasjonsarbeid for å få folk til å faktisk bruke heisen, og de vil nokvære mer villige å benytte seg av den jo høyere etasje de oppholder seg på. Når folk først har lærtseg at heis er trygt, er det uvisst om det er en reell risiko for at folk vil ta heisen også ved brann ibygg som ikke har «trygge soner». Kunnskap om hvordan man skal oppføre seg i en spesifikk bygning ved en brannsituasjon ernødvendig, men det er sannsynligvis ikke gjennomførbart med opplæring på forhånd for allegrupper av brukere i alle typer bygninger. I mange tilfeller vil det være snakk om sporadiskopphold, slik at informasjon i forbindelse med en konkret hendelse vil være mer relevant. Da erbudskapet viktig, og at det fremføres på en måte som alle kan tilegne seg. Det er derfor vanskeligå generalisere eller standardisere behov for opplæring og behov for organisering for alle typerbygg
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