scholarly journals Scaling limits for shortest path lengths along the edges of stationary tessellations

2010 ◽  
Vol 42 (4) ◽  
pp. 936-952 ◽  
Author(s):  
Florian Voss ◽  
Catherine Gloaguen ◽  
Volker Schmidt

We consider spatial stochastic models, which can be applied to, e.g. telecommunication networks with two hierarchy levels. In particular, we consider Cox processes XL and XH concentrated on the edge set T(1) of a random tessellation T, where the points XL,n and XH,n of XL and XH can describe the locations of low-level and high-level network components, respectively, and T(1) the underlying infrastructure of the network, such as road systems, railways, etc. Furthermore, each point XL,n of XL is marked with the shortest path along the edges of T to the nearest (in the Euclidean sense) point of XH. We investigate the typical shortest path length C* of the resulting marked point process, which is an important characteristic in, e.g. performance analysis and planning of telecommunication networks. In particular, we show that the distribution of C* converges to simple parametric limit distributions if a scaling factor κ converges to 0 or ∞. This can be used to approximate the density of C* by analytical formulae for a wide range of κ.

2010 ◽  
Vol 42 (04) ◽  
pp. 936-952
Author(s):  
Florian Voss ◽  
Catherine Gloaguen ◽  
Volker Schmidt

We consider spatial stochastic models, which can be applied to, e.g. telecommunication networks with two hierarchy levels. In particular, we consider Cox processes X L and X H concentrated on the edge set T (1) of a random tessellation T, where the points X L,n and X H,n of X L and X H can describe the locations of low-level and high-level network components, respectively, and T (1) the underlying infrastructure of the network, such as road systems, railways, etc. Furthermore, each point X L,n of X L is marked with the shortest path along the edges of T to the nearest (in the Euclidean sense) point of X H . We investigate the typical shortest path length C * of the resulting marked point process, which is an important characteristic in, e.g. performance analysis and planning of telecommunication networks. In particular, we show that the distribution of C * converges to simple parametric limit distributions if a scaling factor κ converges to 0 or ∞. This can be used to approximate the density of C * by analytical formulae for a wide range of κ.


2015 ◽  
Vol 47 (02) ◽  
pp. 328-354
Author(s):  
C. Hirsch ◽  
D. Neuhäuser ◽  
C. Gloaguen ◽  
V. Schmidt

We consider Euclidean first passage percolation on a large family of connected random geometric graphs in the d-dimensional Euclidean space encompassing various well-known models from stochastic geometry. In particular, we establish a strong linear growth property for shortest-path lengths on random geometric graphs which are generated by point processes. We consider the event that the growth of shortest-path lengths between two (end) points of the path does not admit a linear upper bound. Our linear growth property implies that the probability of this event tends to zero sub-exponentially fast if the direct (Euclidean) distance between the endpoints tends to infinity. Besides, for a wide class of stationary and isotropic random geometric graphs, our linear growth property implies a shape theorem for the Euclidean first passage model defined by such random geometric graphs. Finally, this shape theorem can be used to investigate a problem which is considered in structural analysis of fixed-access telecommunication networks, where we determine the limiting distribution of the length of the longest branch in the shortest-path tree extracted from a typical segment system if the intensity of network stations converges to 0.


2015 ◽  
Vol 47 (2) ◽  
pp. 328-354 ◽  
Author(s):  
C. Hirsch ◽  
D. Neuhäuser ◽  
C. Gloaguen ◽  
V. Schmidt

We consider Euclidean first passage percolation on a large family of connected random geometric graphs in the d-dimensional Euclidean space encompassing various well-known models from stochastic geometry. In particular, we establish a strong linear growth property for shortest-path lengths on random geometric graphs which are generated by point processes. We consider the event that the growth of shortest-path lengths between two (end) points of the path does not admit a linear upper bound. Our linear growth property implies that the probability of this event tends to zero sub-exponentially fast if the direct (Euclidean) distance between the endpoints tends to infinity. Besides, for a wide class of stationary and isotropic random geometric graphs, our linear growth property implies a shape theorem for the Euclidean first passage model defined by such random geometric graphs. Finally, this shape theorem can be used to investigate a problem which is considered in structural analysis of fixed-access telecommunication networks, where we determine the limiting distribution of the length of the longest branch in the shortest-path tree extracted from a typical segment system if the intensity of network stations converges to 0.


2020 ◽  
Vol 2020 (14) ◽  
pp. 305-1-305-6
Author(s):  
Tianyu Li ◽  
Camilo G. Aguilar ◽  
Ronald F. Agyei ◽  
Imad A. Hanhan ◽  
Michael D. Sangid ◽  
...  

In this paper, we extend our previous 2D connected-tube marked point process (MPP) model to a 3D connected-tube MPP model for fiber detection. In the 3D case, a tube is represented by a cylinder model with two spherical areas at its ends. The spherical area is used to define connection priors that encourage connection of tubes that belong to the same fiber. Since each long fiber can be fitted by a series of connected short tubes, the proposed model is capable of detecting curved long tubes. We present experimental results on fiber-reinforced composite material images to show the performance of our method.


Author(s):  
V. Dodokhov ◽  
N. Pavlova ◽  
T. Rumyantseva ◽  
L. Kalashnikova

The article presents the genetic characteristic of the Chukchi reindeer breed. The object of the study was of the Chukchi reindeer. In recent years, the number of reindeer of the Chukchi breed has declined sharply. Reduced reindeer numbers could lead to biodiversity loss. The Chukchi breed of deer has good meat qualities, has high germination viability and is adapted in adverse tundra conditions of Yakutia. Herding of the Chukchi breed of deer in Yakutia are engaged only in the Nizhnekolymsky district. There are four generic communities and the largest of which is the agricultural production cooperative of nomadic tribal community «Turvaurgin», which was chosen to assess the genetic processes of breed using microsatellite markers: Rt6, BMS1788, Rt 30, Rt1, Rt9, FCB193, Rt7, BMS745, C 143, Rt24, OheQ, C217, C32, NVHRT16, T40, C276. It was found that microsatellite markers have a wide range of alleles and generally have a high informative value for identifying of genetic differences between animals and groups of animal. The number of identified alleles is one of the indicators of the genetic diversity of the population. The total number of detected alleles was 127. The Chukchi breed of deer is characterized by a high level of heterozygosity, and the random crossing system prevails over inbreeding in the population. On average, there were 7.9 alleles (Na) per locus, and the mean number of effective alleles (Ne) was 4.1. The index of fixation averaged 0.001. The polymorphism index (PIC) ranged from 0.217 to 0.946, with an average of 0.695.


2020 ◽  
Author(s):  
Sina Faizollahzadeh Ardabili ◽  
Amir Mosavi ◽  
Pedram Ghamisi ◽  
Filip Ferdinand ◽  
Annamaria R. Varkonyi-Koczy ◽  
...  

Several outbreak prediction models for COVID-19 are being used by officials around the world to make informed-decisions and enforce relevant control measures. Among the standard models for COVID-19 global pandemic prediction, simple epidemiological and statistical models have received more attention by authorities, and they are popular in the media. Due to a high level of uncertainty and lack of essential data, standard models have shown low accuracy for long-term prediction. Although the literature includes several attempts to address this issue, the essential generalization and robustness abilities of existing models needs to be improved. This paper presents a comparative analysis of machine learning and soft computing models to predict the COVID-19 outbreak as an alternative to SIR and SEIR models. Among a wide range of machine learning models investigated, two models showed promising results (i.e., multi-layered perceptron, MLP, and adaptive network-based fuzzy inference system, ANFIS). Based on the results reported here, and due to the highly complex nature of the COVID-19 outbreak and variation in its behavior from nation-to-nation, this study suggests machine learning as an effective tool to model the outbreak. This paper provides an initial benchmarking to demonstrate the potential of machine learning for future research. Paper further suggests that real novelty in outbreak prediction can be realized through integrating machine learning and SEIR models.


Author(s):  
Сергей Иванович Вележев ◽  
Антон Михайлович Седогин

В представленной статье авторами рассматриваются вопросы уголовно-правовой охраны топливно-энергетического комплекса Российской Федерации от преступных проявлений, в том числе от коррупционной противоправной деятельности должностных лиц. Такие действия причиняют значительный ущерб нормальному функционированию предприятий топливно-энергетического комплекса. Авторами приводятся результаты исследования некоторых криминологических характеристик должностных лиц, совершивших преступления коррупционного характера. Дан анализ причин и условий, способствующих совершению вышеуказанных противоправных действий. Определена типовая модель преступника для данной категории преступлений и его характеристики: в первую очередь, это высокий уровень компетентности, специальное образование и т. д. Авторами отмечается высокий уровень латентной преступности в данной отрасли. Предложены некоторые пути профилактики данной категории правонарушений. Исследование проводилось на основе анализа конкретных уголовных дел, возбужденных следственными органами по результатам оперативно-розыскной деятельности правоохранительных органов. In the article the authors consider the issues of criminal and legal protection of the fuel and energy complex of the Russian Federation from criminal activity including corrupt illegal practices of officials. The authors cite the results of some criminological characteristics study of the fuel and energy complex staff committed corruption crimes. As a result of these illegal actions significant damage is caused to the normal functioning of the fuel and energy enterprises. Such officials` actions determine not only a wide range of other illegal activities, but also lead to public outcry and discredit the industry as a whole. The analysis of the reasons and conditions contributing to the above illegal actions commission is given. A typical model of a criminal for a given crime category and its characteristics are determined. First of all it is a high level competence, special education, etc. A high level of latent crime in this industry is shown. The study results are presented on the example of specific criminal cases initiated by the investigating authorities based on the results of the operation detection activities of law enforcement agencies. Some ways of preventing this category of offenses are proposed.


1970 ◽  
Vol 19 (1-2) ◽  
pp. 264-267 ◽  
Author(s):  
F.H. Reuling ◽  
J.T. Schwartz

In the late 1950's and early 1960's, it became evident that some glaucoma patients developed elevations of intraocular pressure, which were difficult to control, following prolonged use of systemic or ocular medications containing corticosteroids (Chandler, 1955, Alfano, 1963; Armaly, 1963). In addition, some patients without glaucoma, when treated with steroids for long periods of time, developed clinical signs of chronic simple glaucoma (McLean, 1950; François, 1954; Covell, 1958; Linner, 1959; Goldman, 1962). Fortunately, the elevation of intraocular pressure was reversible if the drug was discontinued.Over the past decade, extensive investigation of the “steroid response” has been undertaken. For this presentation, the steroid response may be considered as a gradual elevation of intraocular pressure, occurring over several weeks, in an eye being medicated with corticosteroid drops several times a day. The elevation in pressure is usually accompanied by a reduction in the facility of aqueous outflow. When relatively large numbers of subjects were tested with topical steroids, so that a wide range of responsiveness could be observed, a variation in individual sensitivity was demonstrated. Frequency distributions of intraocular pressure or change in pressure following steroids showed a skew toward the high side. On the basis of trimodal characteristics which they observed in such frequency distributions, Becker and Hahn (1964), Becker (1965) and Armaly (1965, 1966) considered the possible existence of several genetically determined subpopulations. These investigators distinguished three subpopulations on the basis of low, intermediate, and high levels of pressure response. It was hypothesized that these levels of response characterized three phenotypes, corresponding to the three possible genotypes of an allele pair, wherein one member of the pair determined a low level of response, and the other member determined a high level of response (Armaly, 1967).


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