Search results for "Granger causality [population growth]"
showing 4 items of 4 documents
Carbon accumulation rate in a raised bog in Latvia, NE Europe, in relation to climate warming
2018
The carbon accumulation rate (CAR) over the last 180 years was estimated by measuring carbon concentrations in 1-cm layers in a fine-resolution dated and analysed peat sequence in Teiči Bog, Latvia, NE Europe. We used the Granger causality test to examine the temporal (lagged) relationships between the CAR and the historical climate variables. Our results showed that the average CAR was 192 g C m–2 yr–1 during the last 180 years and 169 g C m–2 yr–1 when excluding the acrotelm where decomposition and the stock of carbon are still not in the balance. The Granger causality test showed significant positive temporal associations between the temperature and the CAR, indicating that the temperatu…
Granger causality analysis of sleep brain-heart interactions
2014
We studied the networks of Granger causality (GC) between the time series of cardiac vagal autonomic activity and brain wave activities, measured respectively as the normalized high frequency (HF) component of heart rate variability and EEG power in the δ, θ, α, Ï, β bands, computed in 10 healthy subjects during sleep. GC analysis was performed by vector autoregressive modeling, and significance of each link in the network was assessed using F-statistics. The whole-night analysis revealed the existence of a fully connected network of brain-heart and brain-brain interactions, with the à EEG power acting as a hub which conveys the largest number of GC links between the heart and brain n…
BVP ir skolinimo elgsena : empiriniai Baltijos šalių ekonomikos požymiai
2021
Darnus ekonominis vystymasis remiasi stabilia ir palankia verslo aplinka, kuri skatina organizacijų konkurencingumą. Komerciniai bankai palengvina kapitalo judėjimą iš mažiau efektyvių ekonomikos sektorių į labiau konkurencingas ekonomikos šakas. Šio tyrimo tikslas – išanalizuoti Baltijos šalių BVP dinamiką 2005-2010 metais ir patikrinti BVP koreliavimą su vietinių komercinių bankų išduotų paskolų verslui skaičiumi. Tyrimo rezultatai parodė, kad yra požymių, jog egzistuoja abipusė priklausomybė tarp BVP veiksnių ir išduotų paskolų, tai savo ruožtu sudaro pagrindą formuoti pasiūlymus, kaip gaivinti Baltijos šalių ekonomiką. Šešiose pramonės šakose atliktas Granger BVP ir skolinimo priežastin…
Algorithms for the inference of causality in dynamic processes: Application to cardiovascular and cerebrovascular variability
2015
This study faces the problem of causal inference in multivariate dynamic processes, with specific regard to the detection of instantaneous and time-lagged directed interactions. We point out the limitations of the traditional Granger causality analysis, showing that it leads to false detection of causality when instantaneous and time-lagged effects coexist in the process structure. Then, we propose an improved algorithm for causal inference that combines the Granger framework with the approach proposed by Pearl for the study of causality among multiple random variables. This new approach is compared with the traditional one in theoretical and simulated examples of interacting processes, sho…