1,721,167 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
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
Säätösuunnittelu CFB-kattiloille yhdistettynä prosessisuunnitteluun
No full textAbstractIntegrated control and process design (ICPD) was implemented for circulating fluidized bed power plants (CFB) in this thesis to obtain fast electrical power load changes. The need to reduce global emissions has resulted in new design requirements for CFB boilers: Combustion power plants are needed for fast load changes due to renewable power variations, and process modifications like oxy-combustion have to be implemented for CFB boilers. This thesis addressed the new requirements by integrating control design with process design for CFB boilers, which was done now for the first time.The work defined an ICPD procedure for closed-loop CFB processes that focuses on load change performance. This was done by reviewing and classifying ICPD literature to select suitable design and analysis methods. The new ICPD procedure consisted of process analysis based on dynamic simulation and state estimation, control structure selection based on relative gain methods, and simultaneous dynamic optimization of process and controller parameters.The design stages were validated through industrial case studies. In the process analysis stage, CFB combustion and flue gas dynamics were studied to define how the boiler should be modified for oxy-combustion. In the control design stage, the relative gain methods were used to identify feasible control structures and performance-limiting interactions in a once-through CFB boiler. In the ICPD optimization stage, the CFB steam path mass storage parameters and controllers were optimized for simulated load change ramps. The goal was to achieve tight output electrical power control and satisfy selected secondary control objectives.The results show how faster load changes and a better flexibility for process modifications are obtained through ICPD compared to sequential process and control design. The design guidelines presented in this thesis thus enable more sustainable power generation in the grid.Original papersOriginal papers are not included in the electronic version of the dissertation.Hultgren, M., Ikonen, E., & Kovács, J. (2014). Oxidant control and air-oxy switching concepts for CFB furnace operation. Computers & Chemical Engineering, 61, 203–219. https://doi.org/10.1016/j.compchemeng.2013.10.018Hultgren, M., Ikonen, E., & Kovacs, J. (2014). Circulating fluidized bed boiler state estimation with an unscented Kalman filter tool. 2014 IEEE Conference on Control Applications (CCA), 310–315. https://doi.org/10.1109/CCA.2014.6981364Hultgren, M., Ikonen, E., & Kovács, J. (2017). Integrated control and process design in CFB boiler design and control—Application possibilities. IFAC-PapersOnLine, 50(1), 1997–2004. https://doi.org/10.1016/j.ifacol.2017.08.180Hultgren, M., Ikonen, E., & Kovács, J. (2017). Once-through circulating fluidized bed boiler control design with the dynamic relative gain array and partial relative gain. Industrial & Engineering Chemistry Research, 56(48), 14290–14303. https://doi.org/10.1021/acs.iecr.7b03259Hultgren, M., Ikonen, E., & Kovács, J. (2019). Integrated control and process design for improved load changes in fluidized bed boiler steam path. Chemical Engineering Science, 199, 164–178. https://doi.org/10.1016/j.ces.2019.01.025Self-archived versionTiivistelmäTässä väitöstutkimuksessa sovellettiin integroitua säätö- ja prosessisuunnittelua (ICPD) kiertoleijupetivoimalaitoksiin (CFB) nopeiden sähkön kuormanmuutosten saavuttamiseksi. Globaalien päästöjen vähentämisen tarve on asettanut uusia suunnitteluvaatimuksia CFB-kattiloille: Uusiutuvan energiantuotannon vaihteluiden vuoksi polttovoimalaitoksia tarvitaan nopeita kuormanmuutoksia varten ja happipolton kaltaisia prosessimuunnoksia on sovellettava CFB-kattiloille. Uusista vaatimuksista johtuviin haasteisiin väitöstutkimus vastasi integroimalla säätö- ja prosessisuunnittelua CFB-kattiloille. Näin tehtiin nyt ensimmäistä kertaa.Työssä määritettiin suljetun piirin CFB-prosesseille kuormanmuutosten suorituskykyä painottava ICPD-suunnittelumalli. Tämä suoritettiin tarkastelemalla ja luokittelemalla ICPD-kirjallisuutta sopivien suunnittelu- ja analyysimenetelmien valitsemiseksi. ICPD-suunnittelumalli koostui dynaamiseen simulointiin ja tilaestimointiin perustuvasta prosessianalyysista, suhteellisen vahvistuksen menetelmiin (”relative gain”) perustuvasta säätörakenteen valinnasta sekä prosessin ja säädinten parametrien yhtäaikaisesta dynaamisesta optimoinnista.Suunnitteluvaiheet validoitiin teollisten tutkimusesimerkkien kautta. CFB:n poltto- ja savukaasudynamiikkaa tutkittiin prosessianalyysivaiheessa, tarkoituksena määrittää, kuinka kattilaa tulisi muuntaa happipolttoa varten. Säätörakenteen valintavaiheessa suhteellisen vahvistuksen menetelmiä käytettiin läpivirtaus-CFB-kattilalle soveltuvien säätörakenteiden ja suorituskykyä rajoittavien vuorovaikutusten määrittämiseen. CFB:n höyrypuolen massavarantoparametrit ja säätimet optimoitiin simuloiduille kuormarampeille ICPD-optimointivaiheessa. Tavoitteena oli saavuttaa tarkka tuotettavan sähkön säätö sekä valitut toissijaiset säätötavoitteet.Tulokset osoittavat, miten ICPD:n kautta saavutetaan nopeampia kuormanmuutoksia ja parempi joustavuus prosessimuutosten osalta vaiheittaiseen prosessi- ja säätösuunnitteluun verrattuna. Työssä esitetyt CFB-kattiloiden suunnittelukäytännöt mahdollistavat täten ympäristöystävällisemmän voimantuotannon verkossa.OsajulkaisutOsajulkaisut eivät sisälly väitöskirjan elektroniseen versioon.Hultgren, M., Ikonen, E., & Kovács, J. (2014). Oxidant control and air-oxy switching concepts for CFB furnace operation. Computers & Chemical Engineering, 61, 203–219. https://doi.org/10.1016/j.compchemeng.2013.10.018Hultgren, M., Ikonen, E., & Kovacs, J. (2014). Circulating fluidized bed boiler state estimation with an unscented Kalman filter tool. 2014 IEEE Conference on Control Applications (CCA), 310–315. https://doi.org/10.1109/CCA.2014.6981364Hultgren, M., Ikonen, E., & Kovács, J. (2017). Integrated control and process design in CFB boiler design and control—Application possibilities. IFAC-PapersOnLine, 50(1), 1997–2004. https://doi.org/10.1016/j.ifacol.2017.08.180Hultgren, M., Ikonen, E., & Kovács, J. (2017). Once-through circulating fluidized bed boiler control design with the dynamic relative gain array and partial relative gain. Industrial & Engineering Chemistry Research, 56(48), 14290–14303. https://doi.org/10.1021/acs.iecr.7b03259Hultgren, M., Ikonen, E., & Kovács, J. (2019). Integrated control and process design for improved load changes in fluidized bed boiler steam path. Chemical Engineering Science, 199, 164–178. https://doi.org/10.1016/j.ces.2019.01.025Rinnakkaistallennettu versioAcademic dissertation to be presented with the assent of the Doctoral Training Committee of Technology and Natural Sciences of the University of Oulu for public defence in the OP-Pohjola auditorium (L6), Linnanmaa, on 3 December 2021, at 1 p.m.Abstract
Integrated control and process design (ICPD) was implemented for circulating fluidized bed power plants (CFB) in this thesis to obtain fast electrical power load changes. The need to reduce global emissions has resulted in new design requirements for CFB boilers: Combustion power plants are needed for fast load changes due to renewable power variations, and process modifications like oxy-combustion have to be implemented for CFB boilers. This thesis addressed the new requirements by integrating control design with process design for CFB boilers, which was done now for the first time.
The work defined an ICPD procedure for closed-loop CFB processes that focuses on load change performance. This was done by reviewing and classifying ICPD literature to select suitable design and analysis methods. The new ICPD procedure consisted of process analysis based on dynamic simulation and state estimation, control structure selection based on relative gain methods, and simultaneous dynamic optimization of process and controller parameters.
The design stages were validated through industrial case studies. In the process analysis stage, CFB combustion and flue gas dynamics were studied to define how the boiler should be modified for oxy-combustion. In the control design stage, the relative gain methods were used to identify feasible control structures and performance-limiting interactions in a once-through CFB boiler. In the ICPD optimization stage, the CFB steam path mass storage parameters and controllers were optimized for simulated load change ramps. The goal was to achieve tight output electrical power control and satisfy selected secondary control objectives.
The results show how faster load changes and a better flexibility for process modifications are obtained through ICPD compared to sequential process and control design. The design guidelines presented in this thesis thus enable more sustainable power generation in the grid.Tiivistelmä
Tässä väitöstutkimuksessa sovellettiin integroitua säätö- ja prosessisuunnittelua (ICPD) kiertoleijupetivoimalaitoksiin (CFB) nopeiden sähkön kuormanmuutosten saavuttamiseksi. Globaalien päästöjen vähentämisen tarve on asettanut uusia suunnitteluvaatimuksia CFB-kattiloille: Uusiutuvan energiantuotannon vaihteluiden vuoksi polttovoimalaitoksia tarvitaan nopeita kuormanmuutoksia varten ja happipolton kaltaisia prosessimuunnoksia on sovellettava CFB-kattiloille. Uusista vaatimuksista johtuviin haasteisiin väitöstutkimus vastasi integroimalla säätö- ja prosessisuunnittelua CFB-kattiloille. Näin tehtiin nyt ensimmäistä kertaa.
Työssä määritettiin suljetun piirin CFB-prosesseille kuormanmuutosten suorituskykyä painottava ICPD-suunnittelumalli. Tämä suoritettiin tarkastelemalla ja luokittelemalla ICPD-kirjallisuutta sopivien suunnittelu- ja analyysimenetelmien valitsemiseksi. ICPD-suunnittelumalli koostui dynaamiseen simulointiin ja tilaestimointiin perustuvasta prosessianalyysista, suhteellisen vahvistuksen menetelmiin (”relative gain”) perustuvasta säätörakenteen valinnasta sekä prosessin ja säädinten parametrien yhtäaikaisesta dynaamisesta optimoinnista.
Suunnitteluvaiheet validoitiin teollisten tutkimusesimerkkien kautta. CFB:n poltto- ja savukaasudynamiikkaa tutkittiin prosessianalyysivaiheessa, tarkoituksena määrittää, kuinka kattilaa tulisi muuntaa happipolttoa varten. Säätörakenteen valintavaiheessa suhteellisen vahvistuksen menetelmiä käytettiin läpivirtaus-CFB-kattilalle soveltuvien säätörakenteiden ja suorituskykyä rajoittavien vuorovaikutusten määrittämiseen. CFB:n höyrypuolen massavarantoparametrit ja säätimet optimoitiin simuloiduille kuormarampeille ICPD-optimointivaiheessa. Tavoitteena oli saavuttaa tarkka tuotettavan sähkön säätö sekä valitut toissijaiset säätötavoitteet.
Tulokset osoittavat, miten ICPD:n kautta saavutetaan nopeampia kuormanmuutoksia ja parempi joustavuus prosessimuutosten osalta vaiheittaiseen prosessi- ja säätösuunnitteluun verrattuna. Työssä esitetyt CFB-kattiloiden suunnittelukäytännöt mahdollistavat täten ympäristöystävällisemmän voimantuotannon verkossa
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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