A5019185243- Monetary Policy and Economic Impact
- Complex Network Analysis Techniques
- Complex Systems and Time Series Analysis
- Climate variability and models
- Fish Ecology and Management Studies
- Marine and fisheries research
- Insurance, Mortality, Demography, Risk Management
- Geophysics and Gravity Measurements
- Statistical Methods and Inference
- Global Financial Crisis and Policies
- Opinion Dynamics and Social Influence
- Geochemistry and Geologic Mapping
- European Socioeconomic and Political Studies
- Hydrological Forecasting Using AI
- Economic theories and models
- Geology and Paleoclimatology Research
- Market Dynamics and Volatility
- Oceanographic and Atmospheric Processes
- Time Series Analysis and Forecasting
- Hungarian Social, Economic and Educational Studies
- Energy Load and Power Forecasting
- Banking stability, regulation, efficiency
- Marine and environmental studies
- Cryospheric studies and observations
- Geochemistry and Elemental Analysis
Aarhus University
2017-2023
Universitat Pompeu Fabra
2013-2016
University of Iceland
1975-2012
National University Hospital
2009
National University Hospital of Iceland
1996
Landsvirkjun (Iceland)
1971-1985
Chinese University of Hong Kong
1985
Iceland GeoSurvey
1972
Institute of Science and Technology
1970
University of Manchester
1970
Catches, stocks and fishing mortality rates are connected by given non-linear relationships. Multivariate time series models of proposed linear approximations to the Kalman filter algorithm used estimate unobserved from observed catches at each age. The model parameters estimated likelihood function catch prediction errors. Time estimation does not require effort measurements as well catch-at-age data, but it is also possible include auxiliary information. Estimates with acceptable accuracy...
Reliable taxonomy underpins communication in all of biology, not least nature conservation and sustainable use ecosystem resources. The flexibility taxonomic interpretations, however, presents a serious challenge for end-users concepts. Users need standardised continuously harmonised reference systems, as well high-quality complete data sets, but these are generally lacking non-specialists. solution is dynamic, expertly curated web-based tools. Pan-European Species-directories Infrastructure...
ABSTRACT: This paper reports our experience in building time series models which connect the flows two Icelandic rivers with meteorological variables of precipitation and temperature. Two different hydrological characteristics were studied. In areas where may be either form rain or snow linear are inadequate to describe relationship between river variables. The methodology threshold recently developed seems well suited for taking into account sharp difference according whether it is freezing...
Fish stock assessment by catch-at-age and survey data is affected many stochastic elements: measurement errors; sampling variations; natural variations in mortality, catchability migrations; technological social effects on fishing intensity selectivity. Estimation of simulated models shows that the bias estimation linear approximation Kalman filter or automatic marginal likelihood function much smaller than errors produced elements. In time series modelling, they are represented residuals...
It is proved that the modulus of Fourier-transform magnetic anomaly a two-dimensional magnetized body determined by two parameters less than those determining itself. This true for any component field. A method developed to calculate estimates from limited amount data and actual examples are given demonstrate how this can be used in interpretation anomalies. The uses all information there record about shape depth concentrates it into few values. also provides convenient way investigating...
Fishing mortality rates are described by a model encompassing common simplifying assumptions, including separable age and year effects, constant rate above the of full recruitment, proportionality to given fishing effort. Each these assumptions can be tested against more general specification. Because great difference in catch numbers for different ages, transformations necessary stabilize variances, care must exercised so that large departures from normality do not invalidate inferences...
We introduce a class of partial correlation network models with community structure for large panels time series. In the model, series are partitioned into latent groups such that is higher within than between them. then propose an algorithm allows one to detect communities using eigenvectors sample covariance matrix. study properties procedure and establish its consistency. The methodology used real activity clustering in United States.
The relationship between oceanographical and meteorological variables off northeast Iceland is re-examined analyzed statistically. analysis confirms the previous hypothesis of a strong connection conditions east Langanes, Iceland, air temperature N-S winds about 90 days prior to observations. Since hydrographic north are known depend largely on influx Atlantic Water from Irminger Sea, average travel time this water northwest coast region Langanes 3 months, lag corresponds closely expected...
A general relation between magnetization and the spectrum of magnetic anomalies is proved under assumption that a product scalar function constant vector. It can be used to find spectra models compare these with actual values in order test hypotheses about formation rocks spatial distribution magnetization. The method suitable for examining some problems distinguishing different hypotheses. Two-dimensional cross-spectra survey from Carlsberg Ridge confirm previous results cannot explained by...
SUMMARY In econometric models each dependent variable is usually a linear function of small number and independent variables which are selected on economic considerations. Here uncorrelated combinations all used for explaining every variable. The by maximizing the sum their squared correlation coefficients with variables. Two numerical examples given data from An model United Kingdom Klein et al. (1961). One based after subtracting average value quarter respective series. second example...
We evaluated levodopa use (LDU) by the Icelandic population focusing on: 1) annual gross (LD) sales from wholesalers to pharmacies for period 1978–1990, using a reported method; 2) data prescription survey conducted October 1st, 1990 March 31st, 1991; and 3) raw on prevalences of Parkinson's disease (PD) in 1963 this country. The standard adjustments reference LDU comparisons was Swedish 1984. Crude LD Iceland Sweden 1984 amounted 1.67 1.35 DDD/1000 person days respectively. After respective...
The relationship between oceanographical and meteorological variables off northeast Iceland is re-examined analyzed statistically. analysis confirms the previous hypothesis of a strong connection conditions east Langanes, Iceland, air temperature N-S winds about 90 days prior to observations. Since hydrographic north are known depend largely on influx Atlantic Water from Irminger Sea, average travel time this water northwest coast region Langanes 3 months, lag corresponds closely expected...
This paper establishes bounds on the performance of empirical risk minimization for large-dimensional linear regression. We generalize existing results by allowing data to be dependent and heavy-tailed. The analysis covers both cases identically heterogeneously distributed observations. Our is nonparametric in sense that relationship between regressand regressors not specified. main this show minimizer achieves optimal (up a logarithmic factor) setting.
The main factors determining the short term variations of river Thjorsa in Iceland are rainfall and melting snow glaciers. Time dependent spectral analysis was applied to investigate seasonal second order properties their relationships with temperature precipitation.In late summer a linear model precipitation at meteorological station Haell provides good fit observations. Because non-linear effects connected models less appropriate during winter although they can still explain significant...
The effects of a fatty acid extract from cod-liver oil on herpes simplex virus type 1 (HSV-1) and the transdermal delivery acyclovir were evaluated. solubilizing effect various alcohols other solvents was also investigated. Both an ointment containing possess notable antiviral activity against HSV-1. A 1% caused 50000-fold or greater reduction viral infectivity in 10 min. An ointment, 30% extract, inactivated about 1.5 million-fold. Acyclovir had greatest solubility polyvalent...
de Pedro-Cuesta J (Instituto Salud Carlos III, Centro Nacional Epidemiología, Departamento Epidemiología Aplicada, c/ Sinesio Delgado, 6, 28029 Madrid, Spain), Gudmundsson G, Abraira V, Lōve A, Tulinius H, Veiga J, Almazán and Petersen I for the EUROPARKINSON Preparatory Activity Research Group. Whooping Cough Parkinson' Disease. International Journal of Epidemiology 1996; 25: 1301–1311. We reported high levodopa use prevalences Parkinson's Disease (PD) in periodically, time-clustered,...
Abstract Linear models of the relationships between meteorological observations and flow river Tungnaá at western margin glacier Vatnajökull were investigated by means spectral analysis estimation impulse response. Most variation is confined to lowest frequencies diurnal variations. The temperature has most effect on rapid variations around 1 cycle/day whereas largest coherences with precipitation are in frequencies. wind explains over 20% frequency range from 0–1 cycle/day, but this partly...
Abstract This paper describes the relationship between central bank interest rates and exchange under a capital control regime. Higher may strengthen currency by inducing owners of local assets not to sell offshore. There is also an effect that goes in opposite direction: higher increase flow income foreigners through current account, making rate fall. The historical financial crisis Iceland provides excellent testing grounds for analysis. Overall, Icelandic experience does suggest cutting...