Evaluating Resilience of Cyber-Physical-Social Systems

Nowadays, protecting the network is not the only security concern. Still, in cyber security, websites and servers are becoming more popular as targets due to the ease with which they can be accessed when compared to communication networks. Another threat in cyber physical social systems with human interactions is that they can be attacked and manipulated not only by technical hacking through networks, but also by manipulating people and stealing users’ credentials. Therefore, systems should be evaluated beyond cy- ber security, which means measuring their resilience as a piece of evidence that a system works properly under cyber-attacks or incidents. In that way, cyber resilience is increas- ingly discussed and described as the capacity of a system to maintain state awareness for detecting cyber-attacks. All the tasks for making a system resilient should proactively maintain a safe level of operational normalcy through rapid system reconfiguration to detect attacks that would impact system performance. In this work, we broadly studied a new paradigm of cyber physical social systems and defined a uniform definition of it. To overcome the complexity of evaluating cyber resilience, especially in these inhomo- geneous systems, we proposed a framework including applying Attack Tree refinements and Hierarchical Timed Coloured Petri Nets to model intruder and defender behaviors and evaluate the impact of each action on the behavior and performance of the system.Hoje em dia, proteger a rede não é a única preocupação de segurança. Ainda assim, na segurança cibernética, sites e servidores estão se tornando mais populares como alvos devido à facilidade com que podem ser acessados quando comparados às redes de comu- nicação. Outra ameaça em sistemas sociais ciberfisicos com interações humanas é que eles podem ser atacados e manipulados não apenas por hackers técnicos através de redes, mas também pela manipulação de pessoas e roubo de credenciais de utilizadores. Portanto, os sistemas devem ser avaliados para além da segurança cibernética, o que significa medir sua resiliência como uma evidência de que um sistema funciona adequadamente sob ataques ou incidentes cibernéticos. Dessa forma, a resiliência cibernética é cada vez mais discutida e descrita como a capacidade de um sistema manter a consciência do estado para detectar ataques cibernéticos. Todas as tarefas para tornar um sistema resiliente devem manter proativamente um nível seguro de normalidade operacional por meio da reconfi- guração rápida do sistema para detectar ataques que afetariam o desempenho do sistema. Neste trabalho, um novo paradigma de sistemas sociais ciberfisicos é amplamente estu- dado e uma definição uniforme é proposta. Para superar a complexidade de avaliar a resiliência cibernética, especialmente nesses sistemas não homogéneos, é proposta uma estrutura que inclui a aplicação de refinamentos de Árvores de Ataque e Redes de Petri Coloridas Temporizadas Hierárquicas para modelar comportamentos de invasores e de- fensores e avaliar o impacto de cada ação no comportamento e desempenho do sistema

A Study on the Effect of Temperature in Synthesis and Magnetic Properties of W-Type Hexaferrites Barium Nanocomposites with Radar Wave Absorbing Properties

Absorption and attenuation of electromagnetic waves spread in air by radar or other equipments is considered as a main problem in military and industrial issues. With increasing development of radars and the raise of detection to solve the issue of camouflage, various methods have been offered including active removal, inactive removal, and absorbing materials and shaping deviate waves. To prepare absorbing materials used in aerospace industry, selecting a wide range of magnetic materials, conducting flow components and dielectric materials applied as matrix are regarded as deterministic factors. The present study attempts to investigate the effect of temperature in synthesis and magnetic properties of w-type hexaferrites barium Nano composites with radar wave absorbing properties. For this purpose, some salts such as cobalt, iron, and barium are employed to produce w-type hexaferrites barium Nano powder (Ba (CoxZn1+x)2 Fe16O27) using sol-gel auto-combustion via microwave. Compared to the other methods, the applied method has the advantages of more affordability, shorter synthesis time, pure specimen, lack of pollution, homogenized final phase, and lack of the need to high temperatures. The produced Nano powders are then analyzed through X-ray diffraction (XRD) in different temperatures revealing a close phase to W-type. A scanning electron microscope (SEM) is also used to determine the particles` size at Nano scale. Moreover, the vibrating magnetometer device is applied in order to depict the hysteresis loop of produced powders so that the rings are longer at the temperatures of 800 ° C and 950 ° C indicating higher magnetic saturation property

A Study on the Effect of Temperature in Synthesis and Magnetic Properties of W-Type Hexaferrites Barium Nanocomposites with Radar Wave Absorbing Properties

Absorption and attenuation of electromagnetic waves spread in air by radar or other equipments is considered as a main problem in military and industrial issues. With increasing development of radars and the raise of detection to solve the issue of camouflage, various methods have been offered including active removal, inactive removal, and absorbing materials and shaping deviate waves. To prepare absorbing materials used in aerospace industry, selecting a wide range of magnetic materials, conducting flow components and dielectric materials applied as matrix are regarded as deterministic factors. The present study attempts to investigate the effect of temperature in synthesis and magnetic properties of w-type hexaferrites barium Nano composites with radar wave absorbing properties. For this purpose, some salts such as cobalt, iron, and barium are employed to produce w-type hexaferrites barium Nano powder (Ba (CoxZn1+x)2 Fe16O27) using sol-gel auto-combustion via microwave. Compared to the other methods, the applied method has the advantages of more affordability, shorter synthesis time, pure specimen, lack of pollution, homogenized final phase, and lack of the need to high temperatures. The produced Nano powders are then analyzed through X-ray diffraction (XRD) in different temperatures revealing a close phase to W-type. A scanning electron microscope (SEM) is also used to determine the particles` size at Nano scale. Moreover, the vibrating magnetometer device is applied in order to depict the hysteresis loop of produced powders so that the rings are longer at the temperatures of 800 ° C and 950 ° C indicating higher magnetic saturation property

Improving Attack Trees Analysis using Petri Net modeling of Cyber-Attacks

Publisher Copyright: © 2019 IEEE.Cyber security is one general concern to all network-based organizations. In recent years, by significant increasing cyber-attacks in critical infrastructures (CIs) the need of smart prediction, awareness and protection systems is not deniable. The first step for security assessment is on recognizing and analyzing attacks. In this paper, one of the graphical security assessments named Attack Tree (AT) is used to illustrate one kind of cyber-attacks scenario in Industry 4.0 and the system's behavior is analyzed by Petri Nets.authorsversionpublishe

100% screening economic order quantity model under shortage and delay in payment

It is for a long time that the Economic Order Quantity(EOQ) model has been successfully applied to inventory management. This paper studies a multiproduct EOQ problem in which the defective items will be screened out by 0 screening process and will be sold after the screening period. Delay in payment is permissible though payment should be made during the grace period and the warehouse capacity is limited. Otherwise, there will be an additional penalty cost for late payment so the retailer would not be able tobuy products at discount prices.All-units and incremental discounts are considered for the products which dependon the order’s quantity just like the permissible delay in payment. Genetic algorithm (GA) and particle swarm optimization (PSO) algorithm are used to solve the proposed model and numerical examples are provided for better illustrations

Operating Room Scheduling Optimization Based on a Fuzzy Uncertainty Approach and Metaheuristic Algorithms

Today, planning and scheduling problems are the most significant issues in the world and make a great impact on improving organizational productivity and serving systems such as medical and healthcare providers. Since operating room planning is a major problem in healthcare organizations, the optimization of medical staff and equipment plays an essential role. Thus, this study presents a multi-objective mathematical model with a new categorization (preoperative, intraoperative, and postoperative) to minimize operating room scheduling and the risk of using equipment. Time constraints in healthcare systems and medical equipment limited capacity are the most significant considered limitation in the present study. In this regard, since the duration of patient preparation and implementation of treatment processes occur in three states of optimistic, pessimistic, and normal, the introduced parameters are examined relying on a fuzzy uncertainty analysis of the problem. Hence, the model is measured in a real numerical solution sample in a medical center to evaluate and confirm the proposed mathematical model. Then, two meta-heuristic algorithms (NRGA and NSGAII) are implemented on the mathematical model to analyze the proposed model. Finally, the research results indicate that the NSGA-II is more efficient in the operating room scheduling problem

Transforming museum management through ICT adoption: an analysis of the Portuguese context during the COVID-19 pandemic

This study aims at analysing the development of digital co-creative strategies adopted by museums during the COVID-19 pandemic and the transformative potential of co-creative experiences with the help of digital tools to redefine the relationship between the museum and its audiences. This is exploratory research using online qualitative surveys applied to Portuguese museums during the COVID-19 pandemic for participation of virtual audiences for data collection and analysis. Results from this study contribute to managers’ awareness of museum digital transformation around the world sharing similar contexts and that may want to develop the participatory approach with the support of digital technologies. Results show new avenues for the adoption and implementation of digital strategies in museum management. To the authors’ knowledge, this is one of the first studies to explore the participatory museum framework combined with the development of digital strategies applied to museums following COVID-19.info:eu-repo/semantics/acceptedVersio

Determining Optimal Lot Size, Reorder Point, and Quality Features for a Food Item in a Cold Warehouse: Data-Driven Optimization Approach

We propose a nonlinear optimization model for determining the optimum lot size and reorder point for a food item distributed through a cold warehouse as well as the optimum quality features, namely temperature, humidity, packaging type, and level of environmental conditions. The item's quality is estimated based on the features mentioned earlier, and then it is used as a constraint in the optimization process. An assumption was made that the inventory is managed under a continuous review policy and the warehouse has limited space. The model seeks to minimize the annual total cost of managing the warehouse. The model will be a nonlinear mixed programming one, which is solved by Pyomo as a leading library in Python language programming. Numerical examples are used to demonstrate the use of the model and, through sensitivity analysis, develop insights into the operation of cold warehouses. This sensitive analysis opens the doors to managerial insight from which managers and policymakers can highly benefit.Comment: 12 pages, 5 figure

Increasing the reliability and the profit in a redundancy allocation problem

This paper proposes a new mathematical model for multi-objective redundancy allocation problem (RAP) without component mixing in each subsystem when the redundancy strategy can be chosen for individual subsystems. Majority of the mathematical model for the multi-objective redundancy allocation problems (MORAP) assume that the redundancy strategy for each subsystem is predetermined and fixed. In general, active redundancy has received more attention in the past. However, in practice both active and cold-standby redundancies may be used within a particular system design and the choice of the redundancy strategy becomes an additional decision variable. The proposed model for MORAP simultaneously maximizes the reliability and the net profit of the system. And finally, to clarify the proposed mathematical model a numerical example will be solved. Keywords: Redundancy Allocation Problem, Serial-Parallel System, Redundancy Strategies, MORAP