1,721,348 research outputs found
A Novel Index for Agricultural Drought Measurement: Soil Moisture and Evapotranspiration Revealed Drought Index (SERDI)
No full textDroughts are common across various climates, typically caused by prolonged decreases in rainfall. Several factors contribute to drought, including the temperature, wind speed, and relative humidity and the timing, amount, and intensity of rainfall during the growing season. This study introduces the Soil Moisture and Evapotranspiration Revealed Drought Index (SERDI), a new index that combines soil moisture and evapotranspiration (calculated using the Penman–Monteith method) to enhance drought early warning systems. To validate the SERDI, we compared it with other established indices such as the Land Surface Temperature (LST), Vegetation Health Index (VHI), Normalized Difference Vegetation Index (NDVI), and Normalized Difference Water Index (NDWI), using metrics like the R-squared (R2), root mean square error (RMSE), mean absolute percentage error (MAPE), and p-value to assess the accuracy, data variability, and forecast conditions. The results showed a low RMSE and high R2 between the SERDI and the LST and VHI, indicating a strong correlation. However, weaker correlations were observed between the SERDI and NDVI/NDWI, as shown by the lower R2 and higher RMSE values in semi-arid areas. Regions across Iran, Iraq, Syria, Jordan, and Israel experienced mostly moderate to severe drought conditions, with a few areas in Iran and Syria showing normal conditions. The SERDI’s strong correlation with the LST and moderate correlation with the VHI can be attributed to the direct influence of the soil moisture and evapotranspiration on the surface temperature and vegetation health. On the other hand, the weaker correlation with the NDVI and NDWI is due to variability in the vegetation response, irrigation practices, and regional differences. This study concludes that the SERDI is an effective tool for the detection of drought based on soil moisture and evapotranspiration
Saplākšņa sendvičpaneļa ar viļņotu serdi eksperimentālās pārbaudes un skaitliskā modelēšana
No full textLaminātu materiālu un konstrukciju
projektēšana, izmantojot uz galīgo elementu metodes (GEM)
bāzētas aprēķina programmas, ļauj efektīvi izstrādāt inovatīvus
risinājumus dažādām mehānisko slodžu konfigurācijām. Tajā
pašā laikā, lai garantētu šādu projektēšanas paņēmiena
precizitāti, ir jābūt verificētam aprēķina modelim, pārbaudītām
materiāla mehāniskajām īpašībām un validētam izstrādātajam
modelim ar eksperimentāliem rezultātiem. Šajā pētījumā
noteiktas vienvirziena līmēta bērza (Betulaspp.) finiera elastīgās
īpašības stiepē vairāk nekā 250 neliela izmēra finiera stiepes
paraugiem. Tika izgatavoti vairāku biezumu paraugi ar dažādu
virsmas apstrādi, lai pētītu ražošanas procesu ietekmi uz finiera
mehāniskajām īpašībām. Iegūtie rezultāti kalpo par ievaddatiem
saplākšņa sendvičpaneļu ar viļņotu serdi parametriskā aprēķina
modeļa izstrādei GEM komercprogrammatūrā ANSYS. Rezultātu
validācija veikta iepriekš izveidotiem sendvičpaneļiem ar viļņotu
serdi 4-punktu lieces laboratorijas testos atbilstoši EN 789 (2004)
standartam. Pētījuma rezultātā noteiktas finiera mehānisko
īpašību robežvērtības, kuras var pielietot saplākšņa plātņu
skaitliskos aprēķinos. Izmantojot iegūtās vērtības, novērtēts
skaitlisko aprēķinu ticamības intervāls salīdzinājumā ar
laboratorijas eksperimentiem, prognozējot paneļa izlieci, kā arī
virsējo šķiedru relatīvās deformācijas. Tika pierādīts, ka
datoraprēķina modeliiespējams veiksmīgi izmantot saplākšņa 3D
struktūru projektēšana
Saplākšņa sendvičpaneļa ar viļņotu serdi eksperimentālās pārbaudes un skaitliskā modelēšana
No full textLaminātu materiālu un konstrukciju projektēšana, izmantojot uz galīgo elementu metodes (GEM) bāzētas aprēķina programmas, ļauj efektīvi izstrādāt inovatīvus risinājumus dažādām mehānisko slodžu konfigurācijām. Tajā pašā laikā, lai garantētu šādu projektēšanas paņēmiena precizitāti, ir jābūt verificētam aprēķina modelim, pārbaudītām materiāla mehāniskajām īpašībām un validētam izstrādātajam modelim ar eksperimentāliem rezultātiem. Šajā pētījumā noteiktas vienvirziena līmēta bērza (Betula sp.) finiera elastīgās īpašības stiepē vairāk kā 250 neliela izmēra finiera stiepes paraugiem. Paraugi izgatavoti ar dažādiem biezumiem un virsmas apstrādi, lai pētītu ražošanas procesu ietekmi uz finiera mehāniskajām īpašībām. Iegūtie rezultāti kalpo kā ievaddati saplākšņa sendvičpaneļu ar viļņotu serdi parametriskā aprēķina modeļa izstrādei GEM komercprogrammatūrā ANSYS. Rezultātu validācija veikta iepriekš izveidotiem sendvičpaneļiem ar viļņotu serdi 4-punktu lieces laboratorijas testos, atbilstoši EN 789 (2004) standartam. Pētījuma rezultātā noteiktas finiera mehānisko īpašību robežvērtības, kuras var pielietot saplākšņa plātņu skaitliskos aprēķinos. Izmantojot iegūtās vērtības, novērtēts skaitlisko aprēķinu konfidences intervāls salīdzinājumā ar laboratorijas eksperimentiem, prognozējot paneļa izlieci, kā arī virsējo šķiedru relatīvās deformācijas. Tika pierādīts, ka datoraprēķina modeli iespējams veiksmīgi izmantot saplākšņa 3D struktūru projektēšanai
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
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