Absolute Population Estimates Using Capture–Recapture Experiments

The main methods used to estimate population size using capture–recapture for both closed and open populations are described, including the Peterson–Lincoln estimator, the Schabel census, Bailey’s triple catch, the Jolly–Seber stochastic method, and Cormack’s log-linear method. The robust design approach is described. R code listings for commonly used packages are presented. The assumptions common to capture–recapture methods are reviewed, and tests for assumptions such as equal catchability described. The use of programs to select model assumptions are described. The main methods for marking different animal groups are described, together with the use of natural marks and parasites and DNA. Marking methods include paint marks, dyes, tagging, protein marking, DNA, natural marks, tattooing, and mutilation. Methods for handling and release are described.

Across-fault ground motions and their effects on some bridges in the 1999 Chi-Chi earthquake

Simply-supported bridges are vulnerable to surface fault rupture as evidenced by several fault-crossing bridges in the 1999 Chi-Chi earthquake. To investigate the seismic collapse mechanism of simply-supported bridges crossing the fault, across-fault ground motions are firstly simulated in the present study. In particular, based on a previously developed fault model of the 1999 Chi-Chi earthquake, broadband across-fault ground motions at six fault-crossing bridges are simulated using the hybrid deterministic-stochastic method, in which the low- and high-frequency components are computed using the deterministic Green’s function method and the stochastic finite-fault modeling method, respectively. The simulation results indicate that the hybrid deterministic-stochastic method can give reasonable predictions to the across-fault ground motions. Furthermore, utilizing the explicit dynamic finite element (FE) code LS-DYNA, behaviors of a three-span simply-supported bridge under a selected pair of across-fault ground motions are numerically simulated. Numerical results indicate that the structural responses and collapse mechanisms are dominated by the low-frequency ground motions. The large differential static offset across the fault is the main reason for the collapse of the simply-supported bridges. This study contributes understandings for the across-fault ground motions and the collapse mechanism of some bridges in the 1999 Chi-Chi earthquake.

Security of Supply in Gas and Hybrid Energy Networks

Reliable energy supply becomes increasingly complex in hybrid energy networks, due to increasing amounts of renewable electricity and more dynamic demand. Accurate modeling of integrated electricity and gas distribution networks is required to quantify operational bottlenecks in these networks and to increase security of supply. In this paper, we propose a hybrid network solver to model integrated electricity and gas distribution networks. A stochastic method is proposed to calculate the security of supply throughout the networks, taking into account the likelihood of events, operational constraints and dynamic supply and demand. The stochastic method is evaluated on a real gas network case study. The calculated security of supply parameters provide insight into the most critical parts of the network and can be used for future network planning. The capabilities of the coupled hybrid energy network simulation are demonstrated on the real gas network coupled to a simplified electricity network. Results demonstrate how combined simulation of electricity and gas networks facilitate the control design and performance evaluation of regional hybrid energy networks.

Mechanism of neural network training for forecasting the meteorological situation when using GIS

This article is devoted to the mechanisms of neural network training for forecasting the meteorological situation when using GIS. The structural scheme of the GIS under consideration is proposed as a project solution and the main elements allowing to implement neural networks and their training are defined. The stochastic method is chosen as a tool for neural network training as it suggests the most probable outcome of the event based on the previous sample. The article gives an example of testing neural network training as an application program «Data Processor». The results described in the article allow us to judge about the applicability of the selected neural network training method for forecasting meteorological conditions and using data in geoinformation decision-making systems. Keywords: geoinformation system, synoptic forecast method, hydrodynamic forecast method, aggregator, data processor, knowledge base, deterministic method, expert estimation method, stochastic method, neural network, sampling, probability dispersion.

OPTIMIZATION OF IDENTIFICATION MODELING IN THE STOCHASTIC METHOD OF TAKING INTO ACCOUNT THE TERRAIN IN THE INTERPRETATION OF AEROMAGNETIZATION

The results of studies aimed at optimizing the stochastic method of taking into account the terrain when interpreting aeromagnetic survey data are presented. The method is based on the consistent application of the method of empirical mode decomposition and the method of group accounting of arguments The results of a medium-scale aeromagnetic survey conducted in Eastern Siberia were used as actual data. It is shown that the preliminary classification of the studied territory by the nature of the relief and the magnetic field strength allows us to determine the components of the magnetic field that correlate with the relief within the selected classes. To assess the quality of correlation dependencies, the ratio of the standard deviation of the models to the variance of the magnetic field amplitudes of the analyzed frequency component were used. This allows us to compare models with different statistical characteristics of the anomalous magnetic field and divide the components into correlated and uncorrelated with the terrain. The results obtained confirm the possibility of the existence of strong correlational relationships between the magnetic field and the relief in a certain range of spatial frequencies and offer specific methodological methods for applying this stochastic approach to reducing the magnetic field in the areas of the development of platobasalts.