scholarly journals Mathematical Problems of Managing the Risks of Complex Systems under Targeted Attacks with Known Structures

Mathematics ◽  
2021 ◽  
Vol 9 (19) ◽  
pp. 2468
Author(s):  
Alexander Shiroky ◽  
Andrey Kalashnikov
Keyword(s):  
Complex Systems ◽  
Optimal Allocation ◽  
Risk Function ◽  
Chain Structure ◽  
System Structure ◽  
Optimal Placement ◽  
Targeted Attacks ◽  
Mathematical Problems ◽  
Local Risk ◽  
Simple Chain

This paper deals with the problem of managing the risks of complex systems under targeted attacks. It is usually solved by using Defender–Attacker models or similar ones. However, such models do not consider the influence of the defending system structure on the expected attack outcome. Our goal was to study how the structure of an abstract system affects its integral risk. To achieve this, we considered a situation where the Defender knows the structure of the expected attack and can arrange the elements to achieve a minimum of integral risk. In this paper, we consider a particular case of a simple chain attack structure. We generalized the concept of a local risk function to account for structural effects and found an ordering criterion that ensures the optimal placement of the defending system’s elements inside a given simple chain structure. The obtained result is the first step to formulate the principles of optimally placing system elements within an arbitrarily complex network. Knowledge of these principles, in turn, will allow solving the problems of optimal allocation of resources to minimize the risks of a complex system, considering its structure.

scholarly journals Optimal placement design for picking and packing in distribution centers

2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110106
Author(s):  
John Rios ◽  
Rodrigo Linfati ◽  
Daniel Morillo-Torres ◽  
Iván Derpich ◽  
Gustavo Gatica
Keyword(s):  
Optimal Allocation ◽  
Programming Model ◽  
Operating Cost ◽  
Nonlinear Integer Programming ◽  
Operating Costs ◽  
Optimal Placement ◽  
Distribution Centers ◽  
Suitable Space ◽  
Efficient Distribution

An efficient distribution center (DC) is one that receives, stores, picks and packs products into new logistics units and then dispatches them to points of sale at the minimal operating cost. The picking and packing processes represent the highest operating cost of a DC, and both require a suitable space for their operation. An effective coordination between these zones prevents bottlenecks and has a direct impact on the DC’s operational results. In the existing literature, there are no studies that optimize the distribution of the picking and packing areas simultaneously while also reducing operating costs. This article proposes an integer nonlinear integer programming model that minimizes order preparation costs. It does so by predicting customer demand based on historical data and defining the ideal area for picking and packing activities. The model is validated through a real case study of seven clients and fifteen products. It achieves a [Formula: see text] reduction in operating costs when the optimal allocation of the picking and packing areas is made.

The mathematical problems of complex systems investigation under uncertainties

2017 ◽  
pp. 135-171
Author(s):  
K. Atoyev ◽  
P. Knopov ◽  
V. Pepeliaev ◽  
P. Kisała ◽  
R. Romaniuk ◽  
...  
Keyword(s):  
Complex Systems ◽  
Mathematical Problems

A Multibody Model for Computer Simulation of Molecular Structures on Supercomputers

2011 ◽  
Author(s):  
Krishna Chaitanya Rudraraju ◽  
Shanzhong Shawn Duan
Keyword(s):  
Chain Structure ◽  
Molecular Structures ◽  
Theoretical Development ◽  
Molecular Method ◽  
Molecular Systems ◽  
Multibody Model ◽  
Computational Performance ◽  
Simple Chain ◽  
Simulation Time ◽  
Motion Behavior

An efficient O(N) algorithm has been developed on the basis of the proper integration between an internal coordinate method (ICM) and a multibody molecular method. The method has been implemented for virtual prototyping of molecular systems with a simple chain structure and the results showed O(N) computational performance. This paper results the application of O(N) procedure to a large molecular chain and show the linear computational load relationship with the number of subsets. Initially, a brief introduction to O(N) procedure and the theoretical development of the algorithm is presented. Later focus will be turned to the implementation of the algorithm on the molecular structure. Finally, the motion behavior and the simulation time are analyzed for different computer systems.

A simple approach for optimal allocation of dampers in nonsymmetrical 3D multi-storey structures

2014 ◽  
Vol 14 (03) ◽  
pp. 1350074 ◽  
Author(s):  
L. J. Leu ◽  
J. T. Chang
Keyword(s):  
Optimal Allocation ◽  
Seismic Analysis ◽  
Search Algorithm ◽  
Three Dimensional ◽  
Time History ◽  
Simple Approach ◽  
Optimal Placement ◽  
Drift Ratio ◽  
History Analysis ◽  
Stop Criterion

A new simple approach is proposed to search for the optimal placement of dampers in nonsymmetrical three-dimensional (3D) structures. Dampers are placed uniformly and initially at each storey of two selected bays of the bare structures and the time-history seismic analysis is performed. The maximal inter-storey drift ratio is chosen as the performance index. Then the inter-storey drift ratio is checked for the locations where dampers were added. The damper in the location with the minimal inter-storey drift ratio is moved to the location having the maximal inter-storey drift ratio. This process is repeated until the prescribed stop criterion is met. Both linear and nonlinear viscous dampers are used in this study. The damping coefficient of added dampers for the initial damper placement is determined by setting the maximal inter-storey drift ratio of the whole structure equal to a certain value when a ground motion is applied. In the proposed relocation process, the maximal inter-storey drift ratio will be reduced significantly. Three examples, including two 10-storey and one 20-storey 3D nonsymmetrical structures, are used to demonstrate the efficiency and accuracy of the proposed approach. The results are compared with those obtained using the simplified sequential search algorithm (SSSA). It is found that the proposed approach requires fewer number of time-history analysis than that using the SSSA while their accuracy is comparable.

scholarly journals Photovoltaic Generation Integration with Radial Feeders Using GA and GIS

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Elias Mandefro Getie ◽  
Belachew Bantyirga Gessesse ◽  
Tewodros Gera Workneh
Keyword(s):  
Power System ◽  
Power Loss ◽  
Optimal Allocation ◽  
Distribution Networks ◽  
Optimal Placement ◽  
Generation System ◽  
Photovoltaic Generation ◽  
Gis Methods ◽  
Pv Generation ◽  
Transmission And Distribution

The electric power generated from different electricity sources are not used efficiently by end users in the world. This is due to the loss of power supplied in the case of electricity transmission and distribution to residential, commercial, and industrial loads. Even if the loss of power in the power system cannot be avoided 100%, it should be reduced to the minimum optimal value. The loss of power in the radial feeders can be minimized using an optimally allocated photovoltaic (PV) generation system by considering the information of geography, solar irradiance of the site, and space availability, which should not have shadow from large buildings and trees. The PV generation system eliminates the problem of power demand by enhancing the capacity of the power network as well as by reducing the depletion and consumption of fossil fuel resources. To reduce power loss and improve system loading capacity for demand response, the integration and finding the optimal place of photovoltaic generation take high concern from power system operators and technicians. The optimal allocation of PV has been done using the Genetic Algorithm (GA) for optimization of a multiobjective function with different constraints. The main objective of this paper is to minimize the power loss of the radial distribution networks by maintaining the phase voltage of the load in balance and improving the drop in voltage along the phase. So, GA is used to determine the best location and capacity of PV generation that can reduce the loss of power in the system. The IEEE-33 bus system is used to test the proposed method. Generally, using the GA and GIS methods results in a high accuracy for optimal placement of PV generation in the IEEE-33 bus radial feeder and enables to reduce the loss of power during transmission and distribution by maintaining the power quality for consumers.

Component allocation for a distributed system: reliability maximization

1993 ◽  
Vol 30 (2) ◽  
pp. 471-477 ◽  
Author(s):  
Mikhail Revyakov
Keyword(s):  
Distributed System ◽  
Convex Functions ◽  
System Reliability ◽  
Optimal Allocation ◽  
System Structure ◽  
External Influences ◽  
Component Allocation ◽  
Schur Convex ◽  
Superadditive Functions

An optimal allocation of subsystems depending on the system structure and reliability ordering of inherent subsystem components is determined, in the presence of various external influences on the reliability of components in different locations. It is carried out with the help of L-superadditive functions and Schur-convex functions.

scholarly journals Mathematical Problems for Complex Systems

2015 ◽  
Vol 2015 ◽  
pp. 1-2
Author(s):  
Haijun Jiang ◽  
Haibo He ◽  
Jianlong Qiu ◽  
Qiankun Song ◽  
Jianquan Lu
Keyword(s):  
Complex Systems ◽  
Mathematical Problems

scholarly journals Management of Information Risks for Complex System Using the «Cognitive Game» Mechanism

2020 ◽  
pp. 2-10
Author(s):  
Andrey Kalashnikov ◽  
◽  
Evgenia Anikina ◽  
Keyword(s):  
Complex System ◽  
Risk Management ◽  
Complex Systems ◽  
Computer Network ◽  
Mutual Influence ◽  
The State ◽  
Theoretic Approach ◽  
Risk Manager ◽  
Game Theoretic ◽  
Local Risk

Purpose of the article: development of mechanisms for solving problems of information risk management of complex systems in conditions of uncertainty and mutual influence of system elements on each other. Research method: game-theoretic mathematical modeling of risk management processes in complex systems based on arbitration schemes and multistep games on cognitive maps. The result: a general model of a complex system (for example, a heterogeneous computer network) is considered, within which the risk manager (risk-manager) carries out effective risk management by distributing the resource at his disposal among its elements (nodes of a computer network). To assess the state of the system elements, functions of local risk are proposed that satisfy certain specified requirements, and to assess the state of the system as a whole, an integral risk function is proposed. It is shown that in the case of independence (absence of mutual influence on each other) of the system elements to find an effective resource allocation, a game-theoretic approach can be used based on an arbitration scheme based on the principles of stimulation and non-suppression (MS-solution). For the case when changes in the level of risk for one element of the system can have a significant impact on the levels of risks of other elements, it is proposed to use game-theoretic models based on the MS-solution and a multistep “cognitive game”.

scholarly journals Cooperation of agents in complex systems based on supervision

2014 ◽  
Vol 14 (1) ◽  
pp. 40-51
Author(s):  
František Čapkovič
Keyword(s):  
Complex Systems ◽  
State Vector ◽  
Discrete Event Systems ◽  
Discrete Event ◽  
The State ◽  
System Structure ◽  
Continuous Systems ◽  
Production Lines ◽  
Supervisor Synthesis

Abstract Complex systems consist of many cooperating devices. To have a transparent view on the system structure, as well as on the structural interconnections and cooperation of the subsystems, it is useful to synthesize the complex systems systematically in a prescribed order, even in analytical terms (if possible). The supervision of the subsystems seems to be a very suitable approach to accomplish these demands, and consequently it makes the complex systems diagnostics easier. The substantial agents (i.e., the agents of material nature − e.g., devices like particular production lines, robots, numerically controlled machines, etc.) can be coordinated and forced to cooperation by means of efficiently synthesized supervisors. The cooperation process has the character of DES (Discrete-Event Systems), because any system (including continuous systems), has minimally two discrete states - idle and working. DES control theory can be successfully utilized in supervisor synthesis. There are several approaches to modeling the agents and the process of supervisor synthesis. The Petri net-based approach is one of them. Place/Transition Petri Nets (P/T PN) are used here for modeling the behaviour of particular agents, as well as in the computational parocess used for the supervisor synthesis. Two main methods of the P/T PN-based supervision will be used, namely (i) the supervision based on the place invariants (P-invariants) of P/T PN, utilizing only the state vector during the supervisor synthesis, and (ii) the extended supervision utilizing not only the state vector, but also the control vector and Parikh’s vector. The efficiency of the proposed approach is illustrated in a case study.

scholarly journals Optimal placement and sizing of distributed generation for loss minimization using ABC optimization

2021 ◽  
Vol 10 (4) ◽  
pp. 347
Author(s):  
Madhu Valavala
Keyword(s):  
Distributed Generation ◽  
Public Services ◽  
Optimal Allocation ◽  
Probabilistic Approach ◽  
Optimal Placement ◽  
Voltage Profile ◽  
High Loss ◽  
Bee Colony ◽  
Delivery Reliability ◽  
Stochastic Optimization Algorithm

The distributed generation (DG) refers to the use of the nearby units of small generation or in the sleefelzentres. Revisions have shown that unfitting choice of the position and scope of the DG can lead to bigger system sufferers than DG's sufferers. Public services are already available before the high loss of energy loss and of the mediocre voltage profile, in particular developing countries cannot tolerate any increase in losses. From optimal allocation, public services in the reduction of system losses improve tension adjustment and improve delivery reliability. This article aims to minimalize the annual system's annual loss through the appropriate positioning and size of the DG units. The artificials bee colony (ABC) of EPA are inspired by the behavior of the API feeding, this method is incredibly conventional, a stroke or a peoplated stochastic optimization algorithm to meet the solution of the specified problem. At MATLAB, a probabilistic approach is simulated to reach the target indicates that the size of the DGs to be installed to reduce almost the same loss as a percentage that the situation in which the load power is considered constant.

Sign in / Sign up

Export Citation Format

Share Document