scholarly journals Prediction and Assessment of Marine Pollution Risk from Ships Based on Statistical Analysis Probability Model

Author(s):  
Hejun Geng ◽  
Xiaobin Jiang ◽  
Deling Wang ◽  
Jie Li
2013 ◽  
Vol 864-867 ◽  
pp. 809-814
Author(s):  
Yun Bin Li ◽  
Cheng Gang Tang ◽  
Xian Feng Wang ◽  
Peng Xu

The oil spill probability is the core problem on studying the risk of oil spill. The oil spill probability model of offshore facilities is established, which based on the ETA model and the oil spill reason analysis of offshore facilities and subsea pipelines. Through a lot of statistics, combined with the actual situation in the Bohai Sea, the probability of various events is calculated. Finally the probability of oil spill for the Bohai Sea oil facilities and subsea pipelines is calculated and providing references for marine pollution prevention and the study of oil spill risks.


Author(s):  
Tom A. B. Snijders ◽  
Mark Pickup

Stochastic Actor Oriented Models for Network Dynamics are used for the statistical analysis of longitudinal network data collected as a panel. The probability model defines an unobserved stochastic process of tie changes, where social actors add new ties or drop existing ties in response to the current network structure; the panel observations are snapshots of the resulting changing network. The statistical analysis is based on computer simulations of this process, which provides a great deal of flexibility in representing data constraints and dependence structures. In this Chapter we begin by defining the basic model. We then explicate a new model for nondirected ties, including several options for the specification of how pairs of actors coordinate tie changes. Next, we describe coevolution models. These can be used to model the dynamics of several interdependent sets of variables, such as the analysis of panel data on a network and the behavior of the actors in the network, or panel data on two or more networks. We finish by discussing the differences between Stochastic Actor Oriented Models and some other longitudinal network models. A major distinguishing feature is the treatment of time, which allows straightforward application of the model to panel data with different time lags between waves. We provide a variety of applications in political science throughout.


2014 ◽  
Vol 584-586 ◽  
pp. 2006-2010
Author(s):  
Tian Chai ◽  
De Qi Xiong

In order to overcome the defects of the present risk assessment model of the pollution from ships, a new mathematic model of quantitative risk assessment based on GIS and AIS is presented and established. Through statistical analysis of historical pollution accidents in the specific sea area and in accordance with the relevant data such as streams of traffic and ship type etc obtained by AIS, the frequency of the ship accident can be calculated. It makes the marine pollution assessment more scientific n and quantitative.


2016 ◽  
Vol 5 (2) ◽  
pp. 141-154 ◽  
Author(s):  
Goran Belamarić ◽  
Željko Kurtela ◽  
Rino Bošnjak

Statistical data, analyses and assessment of maritimepassenger traffic in sea ports in the Republic of Croatia pertaining to the traffic in the Port of Šibenik indicate that, following the expansion and reconstruction of berths for large ships in 2014, marine traffic in the waters of the Port of Šibenik and the Channel of St. Ante has been on the rise. There is therefore a need for pollution risk analysis for the Port of Šibenik. Risk assessment was made using the qualitative method of “Risk assessment-based threat ranking”, following which a scenario involving discharge of harmful substances (oil spill) and possible pollution of the Port of Šibenik and the Channel of St. Ante in difficult navigating conditions in restricted waterways and bad weather was simulated. Marine pollution itself has no direct impact on human life. There are usually no human casualties, although major disasters can affect human health. There can therefore be dire indirect consequences, with negative impact on the eco-system, and consequently on some of the most important branches of industry like tourism, sports, fishing, etc. The prevalent northerly and southerly winds have a particularly high influence on the spreading of oil spills in closedoff waters like those of the Port of Šibenik. The influence of sea currents in the Krka river basin and the Channel of St. Ante is exceptionally strong, especially during heavy rains accompanied by increased water flow. Oil spill simulation is therefore an important tool for planning preventive action and response operations in case of oil spill from ships.


Past studies have indicated that the centroid solid angle is related to probabilities of square prism dice rolls. We explain how it is relevant to these probabilities and how to use the spherical projection to calculate the centroid solid angles for the faces on a square prism. These values are then used in a statistical analysis in the quest of constructing a mathematical probability model. The proposed model is based on the principle that the probability of ending up on a particular resting aspect is proportional to the centroid solid angle of that aspect and inversely proportional to a power of the centroid height in that aspect. Using a power of 2.427, this proposed model fits our data of over 60,000 non-symmetrical square prism dice rolls of various sizes (unequal heights and widths) with the largest magnitude Z-score of 1.01. Different powers can potentially describe other situations; e.g. different surfaces, larger dice, heavier dice, etc.


2020 ◽  
Author(s):  
Roberto Ingrosso ◽  
Piero Lionello ◽  
Mario Marcello Miglietta ◽  
Gianfausto Salvadori

<p>57 tornadoes with intensity Enhanced Fujita Scale 2 or larger that occurred in Italy in the period 2000–2018 are analysed in order to investigate the way two meteorological parameters, namely Wind Shear, calculated in 0-1 km and 0-6 km layers, and CAPE, affect their development. For this purpose, a statistical analysis, by means of homogeneity tests, conditional probabilities and a multivariate analysis via copulas is performed, using two different re-analysis datasets (ERA-Interim and ERA-5). The study indicates that: (a) tornadoes occur mostly in correspondence with positive anomalies of both variables; (b) probability of occurrence is correlated with WS, and (c) is maximum when either WS or CAPE are large. Also, the probability does not increase significantly with CAPE, although sufficiently large values are needed for tornado occurrence. These results are similar for both re-analyses we used and suggest that the selected parameters are reliable precursors for Italian tornadoes.</p>


1966 ◽  
Vol 24 ◽  
pp. 188-189
Author(s):  
T. J. Deeming

If we make a set of measurements, such as narrow-band or multicolour photo-electric measurements, which are designed to improve a scheme of classification, and in particular if they are designed to extend the number of dimensions of classification, i.e. the number of classification parameters, then some important problems of analytical procedure arise. First, it is important not to reproduce the errors of the classification scheme which we are trying to improve. Second, when trying to extend the number of dimensions of classification we have little or nothing with which to test the validity of the new parameters.Problems similar to these have occurred in other areas of scientific research (notably psychology and education) and the branch of Statistics called Multivariate Analysis has been developed to deal with them. The techniques of this subject are largely unknown to astronomers, but, if carefully applied, they should at the very least ensure that the astronomer gets the maximum amount of information out of his data and does not waste his time looking for information which is not there. More optimistically, these techniques are potentially capable of indicating the number of classification parameters necessary and giving specific formulas for computing them, as well as pinpointing those particular measurements which are most crucial for determining the classification parameters.


Sign in / Sign up

Export Citation Format

Share Document