scholarly journals The cover time, the blanket time, and the Matthews bound

Author(s):  
J. Kahn ◽  
J.H. Kim ◽  
L. Lovasz ◽  
V.H. Vu
Keyword(s):  
Climate ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 119
Author(s):  
Pitshu Mulomba Mukadi ◽  
Concepción González-García

Time series of mean monthly temperature and total monthly precipitation are two of the climatic variables most easily obtained from weather station records. There are many studies analyzing historical series of these variables, particularly in the Spanish territory. In this study, the series of these two variables in 47 stations of the provincial capitals of mainland Spain were analyzed. The series cover time periods from the 1940s to 2013; the studies reviewed in mainland Spain go up to 2008. ARIMA models were used to represent their variation. In the preliminary phase of description and identification of the model, a study to detect possible trends in the series was carried out in an isolated manner. Significant trends were found in 15 of the temperature series, and there were trends in precipitation in only five of them. The results obtained for the trends are discussed with reference to those of other, more detailed studies in the different regions, confirming whether the same trend was maintained over time. With the ARIMA models obtained, 12-month predictions were made by measuring errors with the observed data. More than 50% of the series of both were modeled. Predictions with these models could be useful in different aspects of seasonal job planning, such as wildfires, pests and diseases, and agricultural crops.


2008 ◽  
Vol 32 (4) ◽  
pp. 401-439 ◽  
Author(s):  
Colin Cooper ◽  
Alan Frieze

2017 ◽  
Vol 27 (9) ◽  
pp. 093103 ◽  
Author(s):  
Tongfeng Weng ◽  
Jie Zhang ◽  
Michael Small ◽  
Ji Yang ◽  
Farshid Hassani Bijarbooneh ◽  
...  

2009 ◽  
Vol 5 (S267) ◽  
pp. 394-394
Author(s):  
Daniel M. Capellupo ◽  
Fred Hamann ◽  
Joseph C. Shields ◽  
Tom A. Barlow ◽  
Paola Rodriguez

Broad absorption lines (BALs) in quasar spectra identify high-velocity outflows that likely exist in all quasars and could play a major role in feedback to galaxy evolution (e.g., Di Matteo et al. 2005). Studying the variability in these BALs can help us understand the structure, evolution, and basic physical properties of these outflows. We are investigating BAL variability in a sample of 25 luminous quasars at 1.2 < z < 2.9 with multi-epoch observations that cover time scales from less than around a month to 7.7 years in the quasar rest-frame. We investigate changes in the C iv λ1549 BALs, and we see a variety of phenomena, including some BALs that either appeared or disappeared completely and other BALs that did not change at all over the whole observation period.


Author(s):  
Michelle Li Ern Ang ◽  
Dirk Arts ◽  
Danielle Crawford ◽  
Bonifacio V. Labatos ◽  
Khanh Duc Ngo ◽  
...  

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