CARTOGRAPHIC MODELS OF PEST DIFFUSION PROCESSES IN NETWORK CYBERSPACE

Author(s):  
Александр Григорьевич Остапенко ◽  
Алексей Леонидович Сердечный ◽  
Александр Алексеевич Остапенко ◽  
Сергей Сергеевич Куликов

Рассматривается весьма актуальная проблема моделирования процесса диффузии вредоносных кодов и деструктивных контентов в киберпространстве, которое в современных условиях носит все более выраженный сетевой характер. В отличии от ранее широко используемых аналоговых и даже развивающих их дискретных эпидемических моделей, в настоящей работе учитываются статический (накопленную информацию) и динамический (информационный трафик) ресурсы узлов и ветвей сети. Наряду с этим принимается во внимание дозировка вредоноса, внедряемого в сеть для нарушения её работоспособности. Все это позволяет осуществить сетевое картографирование эпидемического процесса, порождаемого в результате диффузии вредоносной инъекции. Предлагаемая модель открывает новую страницу в описании информационных эпидемий (и не только) во взвешенных сетях, где предлагаемая авторами формализация масштабирует изображаемые размеры узлов и ветвей модели в соответствии со значениями ресурсов или потенциалов её элементов. Фактически получается граф (карта) исследуемого сетевого ландшафта, в котором циркулирует информация. В случае внедрения вредоноса компоненты карты окрашиваются с учетом дозировки его присутствия в них, где топологической основой выступают “звезды” сети. Для этого авторами предлагаются соответствующие аналитические выражения. The article deals with a very relevant problem of modeling the process of diffusion of malicious codes and destructive content in cyberspace, which in modern conditions has an increasingly pronounced network character. In contrast to the previously widely used analog and even developing discrete epidemic models, this paper takes into account the static (accumulated information) and dynamic (information traffic) resources of nodes and branches of the network. Along with this, the dosage of the malware introduced into the network to disrupt its performance is taken into account. All this makes it possible to carry out network mapping of the epidemic process generated as a result of the diffusion of malicious injection. The proposed model opens a new page in the description of information epidemics (and not only) in weighted networks, where the formalization proposed by the authors scales the depicted sizes of nodes and branches of the model in accordance with the values of resources or potentials of its elements. In fact, a graph (map) of the network landscape under study is obtained, in which information circulates. In the case of the introduction of the malware, the map components are colored taking into account the dosage of its presence in them, where the topological basis is the “stars” of the network. For this purpose, the authors propose the corresponding analytical expressions.

1979 ◽  
Vol 16 (01) ◽  
pp. 198-202 ◽  
Author(s):  
L. Billard ◽  
H. Lacayo ◽  
N. A. Langberg

Classical epidemic models have invariably proved to be mathematically intractable. By considering the distribution of the number of infectives in a simple epidemic process as a convolution of exponential waiting times, the solution to the classical model is obtained easily giving more insight into the underlying structure. The idea can be extended to other simple epidemic models.


Mathematics ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 396 ◽  
Author(s):  
Zizhen Zhang ◽  
Soumen Kundu ◽  
Ruibin Wei

In this paper, we investigate a delayed SEIQRS-V epidemic model for propagation of malicious codes in a wireless sensor network. The communication radius and distributed density of nodes is considered in the proposed model. With this model, first we find a feasible region which is invariant and where the solutions of our model are positive. To show that the system is locally asymptotically stable, a Lyapunov function is constructed. After that, sufficient conditions for local stability and existence of Hopf bifurcation are derived by analyzing the distribution of the roots of the corresponding characteristic equation. Finally, numerical simulations are presented to verify the obtained theoretical results and to analyze the effects of some parameters on the dynamical behavior of the proposed model in the paper.


2002 ◽  
Vol 02 (04) ◽  
pp. L273-L278 ◽  
Author(s):  
DMITRII KHARCHENKO

We consider the stochastic system with an anomalous diffusion. According to the obtained relations between characteristics of diffusion processes the special class of models which exhibit the anomalous behaviour is considered. It was shown that indexes of super- and subdiffusion are related to the Hürst exponent which defines the properties of the phase space inherent to the proposed model of stochastic system.


Author(s):  
Yusuke Tanaka ◽  
Tomoharu Iwata ◽  
Takeshi Kurashima ◽  
Hiroyuki Toda ◽  
Naonori Ueda

Analyzing people flows is important for better navigation and location-based advertising. Since the location information of people is often aggregated for protecting privacy, it is not straightforward to estimate transition populations between locations from aggregated data. Here, aggregated data are incoming and outgoing people counts at each location; they do not contain tracking information of individuals. This paper proposes a probabilistic model for estimating unobserved transition populations between locations from only aggregated data. With the proposed model, temporal dynamics of people flows are assumed to be probabilistic diffusion processes over a network, where nodes are locations and edges are paths between locations. By maximizing the likelihood with flow conservation constraints that incorporate travel duration distributions between locations, our model can robustly estimate transition populations between locations. The statistically significant improvement of our model is demonstrated using real-world datasets of pedestrian data in exhibition halls, bike trip data and taxi trip data in New York City.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Yang Ding ◽  
Jing-liang Dong ◽  
Tong-lin Yang ◽  
Zhong-ping Wang ◽  
Shuang-xi Zhou ◽  
...  

With the increase of the long-span bridge, the damage of the long-span bridge hanger has attracted more and more attention. Nowadays, the probability statistics method based on Bayes’ theorem is widely used for evaluating the damage of bridge, that is, Bayesian inference. In this study, the damage evaluation model of bridge hanger is established based on Bayesian inference. For the damage evaluation model, the analytical expressions for calculating the weights by finite mixture (FM) method are derived. In order to solve the complex analytical expressions in damage evaluation model, the Metropolis-Hastings (MH) sampling of Markov chain Monte Carlo (MCMC) method was used. Three case studies are adopted to demonstrate the effect of the initial value and the applicability of the proposed model. The result suggests that the proposed model can evaluate the damage of the bridge hanger.


Author(s):  
Jafar Ababneh ◽  
Fadi Thabtah ◽  
Hussein Abdel-Jaber ◽  
Wael Hadi ◽  
Emran Badarneh

Congestion in networks is considered a serious problem; in order to manage and control this phenomena in early stages before it occurs, a derivation of a new discrete-time queuing network analytical model based on dynamic random early drop (DRED) algorithm is derived to present analytical expressions to calculate three performance measures: average queue length (Qavg,j), packet-loss rate (Ploss,j), and packet dropping probability (pd(j)). Many scenarios can be implemented to analyze the effectiveness and flexibility of the model. We compare between the three queue nodes of the proposed model using the derived performance measures to identify which queue node provides better performance. Results show that queue node one provides highest Qavg,j, Ploss,j, and (pd(j)) than queue nodes two and three, since it has the highest priority than other nodes. All the above results of performance measure are obtained only based on the queuing network setting parameters.


2021 ◽  
Vol 16 (4) ◽  
pp. 71-79
Author(s):  
Yuriy Ivanschikov ◽  
Vasiliy Skovorodin ◽  
Yuriy Dobrohotov ◽  
Roman Andreev ◽  
Aleksandr Vasil'ev ◽  
...  

A significant number (up to 25%) of failures of automotive transmissions are associated with a loss of rigidity in the rolling bearings. One of the main reasons for the loss of stiffness in rolling bearings is a violation of the tightness of the bearing on the shaft and in the housing due to fretting corrosion. The paper presents the results of a study of the causes of fretting corrosion in bearing fits and the patterns of its development. The conditions promoting the occurrence of the fretting process are determined and the factors characterizing the nature and intensity of destruction of contacting surfaces during fretting corrosion are established. It was also found that the greatest influence on the occurrence and course of the fretting process is exerted by the specific load on the contact surface, the duration and frequency of its application, and the amplitude of the relative slip of the contacting surfaces. Analytical expressions for calculating the actual values of the listed factors of the fretting process in the coupling of the rolling bearing with the shaft are determined by the calculation method, and a mathematical model of its destruction is proposed. For the practical implementation of the described mechanism of destruction of the rolling bearing landing on the shaft as a result of fretting corrosion, an algorithm and a program have been developed to determine the limiting state of the bearing landings of automotive transmissions. Subsequent laboratory tests confirmed the adequacy of the proposed model. As an example, the results of modeling the limiting state of the rolling bearing of the intermediate shaft of the gearbox of the K-700A tractor and the ball bearing 313 are given. It is revealed that the main role in reducing the intensity of the fretting process, along with the hardness of the shaft, is played by the roughness of its seating surface. In particular, a decrease in the roughness parameters from Ra = 2.0 µm to Ra = 0.5 µm at the same hardness HRC48 and an interference fit in N = 24 µm leads to an increase in the joint resource by 1.5 times


2008 ◽  
Vol 35 (1-3) ◽  
pp. 305-322 ◽  
Author(s):  
Milena Vujosevic

The work focuses on the thermally induced deformations caused by the processing of Flip Chip Ball Grid Arrays (FCBGA). Analytical expressions for substrate displacements are derived based on the Plate Theory and Suhir's solution for stresses in tri-material assembly. The validity of the model is established by comparing the analytical solution to the numerical finite element results as well as to the experimental data. The benefits of the proposed model are twofold: 1) it provides a tool for fundamental understanding of the deformation process of interest, and 2) has a predictive capability. More specifically, an analysis is presented on the nature and degree of influence that different geometric and material parameters have on the substrate deflections, as well as a "Warpage Contour Plot", proposed as a tool for warpage prediction that can be easily utilized in the early stages of the design process.


2014 ◽  
Vol 70 (3) ◽  
pp. 621-646 ◽  
Author(s):  
Romain Guy ◽  
Catherine Larédo ◽  
Elisabeta Vergu

1986 ◽  
Vol 18 (2) ◽  
pp. 289-310 ◽  
Author(s):  
Frank Ball

We provide a unified probabilistic approach to the distribution of total size and total area under the trajectory of infectives for a general stochastic epidemic with any specified distribution of the infectious period. The key tool is a Wald&s identity for the epidemic process. The generalisation of our results to epidemics spreading amongst a heterogeneous population is straightforward.


Sign in / Sign up

Export Citation Format

Share Document