Cyber Network Research Articles

HO-OTSVD: A Novel Tensor Decomposition and Its Incremental Decomposition for Cyber–Physical–Social Networks (CPSN)

The development of social networks and ubiquitous sensing promotes the network space into a new stage, which integrates the cyber network, physical network, and social network into cyber–physical–social networks (CPSN). In this paper, we propose a CPSN-based service framework. The framework firstly represents CPSN as an adjacency tensor. Then, a novel tensor decomposition method named high-order orthogonal tensor singular value decomposition (HO-OTSVD) is proposed for knowledge discovery. To cope with the dynamic CPSN, an incremental HO-OTSVD (IHO-OTSVD) is developed to update the orthogonal tensor basis and the core tensor. Furthermore, we propose high-order bidiagonal Lanczos algorithm to cope with the orthogonalization of HO-OTSVD, wherein the complexity reduces from cubic execution time to quadratic execution time. Finally, we use a recommendation system as a case study to evaluate the effectiveness and efficiency of the proposed CPSN-based framework. The results show that HO-OTSVD method outperforms the existing methods.

Classical Failure Modes and Effects Analysis in the Context of Smart Grid Cyber-Physical Systems

Reliability assessment in traditional power distribution systems has played a key role in power system planning, design, and operation. Recently, new information and communication technologies have been introduced in power systems automation and asset management, making the distribution network even more complex. In order to achieve efficient energy management, the distribution grid has to adopt a new configuration and operational conditions that are changing the paradigm of the actual electrical system. Therefore, the emergence of the cyber-physical systems concept to face future energetic needs requires alternative approaches for evaluating the reliability of modern distribution systems, especially in the smart grids environment. In this paper, a reliability approach that makes use of failure modes of power and cyber network main components is proposed to evaluate risk analysis in smart electrical distribution systems. We introduce the application of Failure Modes and Effects Analysis (FMEA) method in future smart grid systems in order to establish the impact of different failure modes on their performance. A smart grid test system is defined and failure modes and their effects for both power and the cyber components are presented. Preventive maintenance tasks are proposed and systematized to minimize the impact of high-risk failures and increase reliability.

Robust self-consistent control of PV-battery-based microgrids without continuous communication

This paper presents a robust two-layer distributed control scheme to regulate the power output of massive distributed energy resources (DERs) (e.g., photovoltaics (PVs) and battery energy storage systems (BESSs)) in an islanded ac microgird, which can achieve the self-consistent proportional power sharing across the whole microgird system with time delay merely through limited noncontinuous communication among DERs based on their status and capacities. By employing delay-based event-triggered communication, the proposed control scheme only relies on limited aperiodic communication, which can greatly reduces the communication cost in the cyber network, moreover is also robust to time delays. Furthermore, the proposed control scheme is fully distributed, thus each DER only requires the local voltage and current measurement from its own and some neighbors for the distributed power sharing control at the last event-triggered time instant to achieve self-consistent active and reactive power outputs. The inequality technique is employed to devise the stability and convergence analysis of the proposed dynamic event-triggered conditions. The effectiveness of the proposed control strategy is verified under various scenarios obtained from OPAL-RT simulator by a modified IEEE 34-bus test network in MATLAB/SimPowerSystems.

Two-Layer Cooperative Control for Multiple Converter-Network Clusters

Cooperative control are mainly employed for multi-converter networks due to the distributed nature of renewable resources and communication network limitations. By dividing all converters within each converter-network (CN) cluster into the leader-converters and follower-converters according to their physical cluster topology structure, the leader and follower control layers are respectively formulated. Then a two-layer cooperative strategy is developed, under which the weighted average voltage of all converters can be regulated to their rated references, meanwhile, the accurate current sharing can be simultaneously realized not only within each CN cluster but also among multiple CN clusters. Compared with previous work, the proposed control strategy has the advantages of accurate current sharing, short time consumption and faster convergence. All controllers are fully distributed and can be applied in all sparse two-layer cyber networks, and control time constant condition is derived to ensure the system stability. Different cases in MATLAB/SimPowerSystems are investigated to verify the effectiveness of the results.

Modeling and Vulnerability Analysis of Cyber-Physical Power Systems Based on Community Theory

Nowadays, power grids are equipped with sensors to monitor and collect the information of power nodes. These sensors are connected by optical fibers and form a cyber network. A power grid coupled with a cyber network is called a cyber-physical power system (CPPS). To study the cascading failure, we analyze the vulnerability of CPPS under community attack styles. CPPS model consists of a power layer, a cyber layer, and the association of them where topology consistency and scale-free cyber networks are considered, respectively. The concepts of the control center and dispatch community are presented. Controllable and uncontrollable power nodes and observable and unobservable power lines are defined. The minimum load reduction model is given and described as a linear programming problem. Several indexes are introduced to assess the vulnerability of CPPS. New England 39 nodes system is taken as an example to analyze the effects of different attacks and different cyber networks on the cascading failure process. The simulation results provide some opinions for the attacker and electricians.

Nonlinear Mean-Square Power Sharing Control for AC Microgrids Under Distributed Event Detection

This article proposes a nonlinear distributed cooperative control scheme that can regulate the power output to achieve efficient utilization of renewable energy in ac microgirds, which ensures mean-square autonomous proportional power sharing over a nonlinear microgird system via a sparse cyber network subject to noisy disturbance and limited bandwidth constraints. The cyber networks are exposed to noisy disturbances and limited bandwidth constraints that terribly reduce the stability and quality of the whole system. To eliminate the adverse effects of noisy disturbances and limited bandwidth constraints, we propose a robust distributed control strategy designed by using partial feedback linearization for the dynamical nonlinear model of a microgrid system. Moreover, a distributed event detection mechanism with noise-dependent threshold is adopted to update the control signals with the consideration of unnecessary data communication reduction. Through adopting stochastic stability theory and Lyapunov function, the stability and convergence analysis of the proposed dynamic distributed event-detection conditions considering noise interferences is derived. As a result, the suggested method decreases the sensitivity of the system to failures and increases its reliability. Finally, a modified IEEE 34-bus test system in MATLAB/Simulink is utilized to verify the effectiveness of the proposed controller design scheme.

Dual Hidden Failure Model for Cyber Physical Power System

With the increasingly close coupling between the cyber network and the physical power grid in Cyber Physical Power System (CPPS), the failure of cyber network has become an important cause of blackout. Equipment failure or abnormal operation state will be appeared without alarm in complex cyber network, which brings hidden failures not been diagnosed and dealt with in time. The invisibility and harmfulness of hidden failures pose a significant threat to the safe, reliable, and stable operation of CPPS. The dual hidden cascading failure model for CPPS is proposed to reveal the failure characteristics of CPPS accurately, considering not only the hidden faults in the power grid, but also the hidden failures in the cyber network. With the different coupled relationships between power systems and cyber networks, the cyber network topology with corresponding failure threshold is obtained according to the simulation of the model with different hidden failure rates of cyber network nodes. When the hidden failure rate is lower than the failure threshold, the scale-free topology cyber network coupled mode is adopted between power grids and cyber networks, otherwise the small-world topology cyber network coupled mode is adopted, which can effectively reduce the risk of power system blackouts. The method proposed in this paper is tested by using IEEE-118 power system and its cyber network. The results show that the method is effective.

Power System Security With Cyber-Physical Power System Operation

Cyber-attacks on a cyber-physical power system could lead to significant data failure, false data injection and cascading failure of physical power system components. This paper proposes an advanced approach based on a ternary Markovian model of cyber-physical components interactions to capture the subsystem layers’ interactions of the cyber-physical power system and to quantify the interdependency impacts on physical power system security. The approach models cyber-physical interactive operation based on interactions and characteristics of three subsystem layers of the system with the presence of random and unforeseen contingencies, load demand variations and then quantify the impacts with Monte Carlo simulation. The viability of the approach is investigated by simulating a set of scenarios, representing realistic physical power system operating conditions with the cyber network interactions. Findings justify the presence of cyber-attacks in a cyber-physical power system components operation could lead to severe insecurities. However, the impacts on physical power system security does not always correlate with the severity of cyber-attacks.

Droop-Based Two-Layer Cooperation for Multiple DC Microgrid Clusters

Enabling energy exchange among multiple dc microgrids (MGs) and adjusting the current outputs of all converters proportional to their power capacities can significantly improve power supply reliability as well as effectively avoid overloaded or uncertainty. By dividing all converters within each dc MG cluster into the leader-converters and follower-converters according to their physical cluster topology structure, the leader and follower control layers are respectively formulated. Then a droop-based two-layer cooperative strategy is developed, under which the weighted average voltage of all converters can be regulated to their rated references, meanwhile, the accurate current sharing can be simultaneously realized not only within each dc MG but also among multiple dc MG clusters. All controllers are fully distributed and can be applied in all sparse two-layer cyber networks, control time constant related sufficient conditions are also derived to ensure the whole system stability. The effectiveness of the results are verified through different cases in MATLAB/SimPowerSystems.

Elaborate Reliability Evaluation of Cyber Physical Distribution Systems Considering Fault Location, Isolation and Supply Restoration Process

The existing reliability models of the cyber physical distribution systems, which are mostly based on some simplified assumptions, cannot accurately evaluate the reliability of complex cases in practical engineering applications. To solve this problem, an elaborate reliability evaluation method considering the whole process of fault location, isolation and supply restoration is proposed. This paper establishes reliability models of components and the two systems, summarizes the mapping relationship between various cyber system failures and the physical fault handling into several laws, proposes the reliability evaluation procedure in the framework of Monte Carlo method, and verifies the feasibility and effectiveness of the method in an actual distribution network cyber physical system. In the proposed method, the multiple component characteristics, complex topological structure, coupling relationship of the cyber-physical distribution systems, and the actual human-computer joint participation are considered in the analysis of fault location, isolation and supply restoration process, which provides a effective and accurate theory for the application of reliability evaluation in the actual distribution network and prosumer energy management system.

How the development of Blockchain affected cybersecurity

This research gives a brief insight into one of the most widely used technologies known as Blockchain. The paper lays the groundwork of how Blockchain functions and how it has quickly become a network with millions of users throughout the world. This study discusses the most important use of Blockchain technology, which is the enhancement of the cyber-security industry. Blockchain has revolutionized the cyber-security industry by introducing a system which is not bound to any four walls and is widely distributed all around the world, seeking refuge on millions of user servers. This decentralized system helps Blockchain defend cyber networks against security threats and attacks such as malware, phishing attacks, and DDoS.

Real-Time Monitoring and Control of Industrial Cyberphysical Systems: With Integrated Plant-Wide Monitoring and Control Framework

Industrial cyberphysical systems (ICPSs) are the cornerstone research subject in the era of Industry 4.0 [1]. The study of ICPSs has, therefore, become a worldwide research focus [2]-[4]. ICPSs integrate physical entities with cyber networks to build systems that can work more harmoniously, benefiting from integrated design and system-wide optimization [5]. The safety and performance of industrial systems can be improved by developing specific information infrastructure, monitoring, and control approaches aimed at maintaining controllability under external disturbances and unexpected faults [6]. Based on these observations, the design and deployment of ICPSs have both theoretical and practical significance.

Anomaly Detection in Distributed Denial of Service Attack using Map Reduce Improvised Counter Based Algorithm in Hadoop

A Distributed denial of Service attacks(DDoS) is one of the major threats in the cyber network and it attacks the computers flooded with the Users Data Gram packet. These types of attacks causes major problem in the network in the form of crashing the system with large volume of traffic to attack the victim and make the victim idle in which not responding the requests. To detect this DDOS attack traditional intrusion detection system is not suitable to handle huge volume of data. Hadoop is a frame work which handles huge volume of data and is used to process the data to find any malicious activity in the data. In this research paper anomaly detection technique is implemented in Map Reduce Algorithm which detects the unusual pattern of data in the network traffic. To design a proposed model, Map Reduce platform is used to hold the improvised algorithm which detects the (DDoS) attacks by filtering and sorting the network traffic and detects the unusual pattern from the network. Improvised Map reduce algorithm is implemented with Map Reduce functionalities at the stage of verifying the network IPS. This Proposed algorithm focuses on the UDP flooding attack using Anomaly based Intrusion detection system technique which detects kind of pattern and flow of packets in the node is more than the threshold and also identifies the source code causing UDP Flood Attack.

Visual displays for cyber network defense

Five computer network Defence displays (one Alphanumeric and four graphical displays: Radial Traffic Analyser, Bar Graph, Cube, and Treemap) were evaluated. Two experiments were conducted using different methodological procedures. Participants responded to questions that were structured to approximate various ways in which analysts might need to consider network traffic. Numerous significant effects were obtained and a fairly clear rank ordering of performance for the four graphical displays was obtained across experiments (from best to worst): Bar Graph, Cube, Radial Traffic Analyser, and Treemap. The results are interpreted from the perspective of ecological interface design: the quality of performance is directly related to the quality of semantic mapping between work domain, display, and human constraints. Factors that may have contributed to the poor performance for the Radial Traffic Analyser and Treemap displays are discussed. General implications for display and interface design are provided. Practitioner summary: Proposed displays for computer network Defence are evaluated; the results are interpreted from the perspective of ecological interface design. The associated design principles are applicable to all analogical graphical displays. Abbreviation: CND: cyber network defence; CSE: cognitive systems engineering; EID: ecological interface design; ICMP: internet control message protocol; IP: internet protocol; RTA: radial traffic analyzer; TCP: transmission control protocol; UDP: user datagram protocol

Cascading Failure of Cyber-Coupled Power Systems Considering Interactions Between Attack and Defense

In this paper, we develop a network-based model with consideration of the physical power flow process to study the cascading failure in cyber-coupled power systems. We take the coupling between power and cyber networks as being resulted from the interdependence of power nodes and cyber nodes. Interaction between two processes, one aiming to attack (cause damage) and the other aiming to defend (protect) the components in the power network, is considered in the model. This interaction offers a novel perspective to interpreting the interdependence of power and cyber networks. To study how an attacker or defender deploys resources to attack or protect a power component, four strategies in distributing the attack and defense strengths are considered, namely, even distribution, degree-based distribution, capacity-based distribution, and random distribution. To probe into the actual propagation process of a blackout, we define four critical time points, namely, start time, attack time, isolation time and end time, and use these time points to analyze and evaluate the effectiveness of different attack and defense strategies. The tit-for-tat defense strategy, in which defender adopts the same strategy as the attacker, is found to be the preferred defense strategy under most conditions. Moreover, allocating defense strength in terms of capacity-based distribution can most effectively suppress cascading failure. This finding was not obtainable without due consideration of the physical power flow process in network-based models.

Cluster-Oriented Distributed Cooperative Control for Multiple AC Microgrids

Matching power transfer between microgrids (MGs) enables maximum utilization of distributed energy resources (DERs), this paper proposes a cluster-oriented cooperative control strategy for multiple ac MG clusters, under which the power sharing among multiple MG clusters can be achieved by an intercluster scheme, whereas the frequency/voltage of all DERs within each MG cluster can also be regulated by an intracluster scheme. By pinning one or some cluster-head DERs from each MG cluster to constitute an intercluster communication network, the intercluster control layer can generate the frequency/voltage references based on the power mismatch among multiple MG clusters. In the intracluster control layer, the pinned DERs propagate these references to their neighbors in an MG cluster, and the frequency/voltage nominal set-points for each DER in the primary control process can be adjusted based on the frequency/voltage errors across the intracluster communication networks. Since the evolutions of intra- and intercluster dynamics may involve different time scales, the upper bound for the ratio of the associated intra- and intercluster time constants is finally derived to guarantee the stability of the whole multi-MG-cluster system. In special, both the intra- and intercluster controllers are designed based on their own sparse cyber networks, allowing different numbers of heterogeneous DERs in each MG cluster. The effectiveness of the control methodology is verified by the simulation of an ac multi-MG-cluster system in MATLAB/SimPowerSystems.

Literature and Popularity: Shakespeare as a Mediator between the ‘Class’ and the ‘Mass’

Shakespeare has enjoyed immense popularity and recognition among ‘elite’ critics like Ben Jonson in his own time, and Dr Samuel Johnson, Coleridge, Matthew Arnold, T S Eliot among others, till Harold Bloom in the 21st century, not to mention the enormous body of film adaptations, translations, music adaptations and various other mass-media through which he still dominates the ‘popular culture’. This is the reason why his case becomes a curious one as far as literature and popularity are concerned. The new century has brought a whole host of new technological artefacts within hand’s reach of all but the poorest denizens of the city street – the cell phone, the iPad, and attendant applications that help us navigate the city and connect and network cyber and physical spaces. These technologies are creating new cultures, material and aesthetic, cyber and physical space-making of new kinds that do not simply alter older traditions but transmogrify them into new shapes and flows. This paper aims at studying how we define the popular aspect of literature. How have erudite and popular cultures been studied in the 20th and 21st centuries? Where does Shakespeare stand in the debate?

Formal modeling of cyber-physical resource scheduling in IIoT cloud environments

In the recent years, the topic of Industrial Internet of Things (IIoT) has attracted a large number of academic researchers and industry practitioners. IIoT connects the actors, and the physical and cyber resources of industrial systems, manufacturing- or service-based, in a cloud-enabled overall data exchange system. This work outlines a formal model for operational scheduling of cyber-physical resources for different scenarios determined by resource and logistics availability and cost. Information exchange of physical work-in-process, resource failures, alternative resource options, order and logistics information, are used to deliver real-time scheduling to IIoT participants. The model is formalized using discrete state-machine diagrams for resource reliability and availability status, and logistics timing purposes. Low-performance solution invariants are generated and validated through functional requirements test case building. The data exchange network between the processing nodes of the IIoT environment is built on a software-defined network foundation. A simulation is then built for a series of work-in-process orders and their required processing operations, several manufacturing enterprises and associated physical logistics, and the cloud IIoT network cyber infrastructure for data and control information sharing. Both the formalized and the simulation models are run in the IIoT cloud and can be accessed by the participating enterprises. The formalized model provides insights on resource repair or replacement options, part transfer decisions, while the simulation model builds on those decisions and runs only validated scenarios anchored in timing- and cost-based constraints.

Cyber-based design for additive manufacturing using artificial neural networks for Industry 4.0

Additive Manufacturing (AM) requires integrated networking, embedded controls and cloud computing technologies to increase their efficiency and resource utilisation. However, currently there is no readily applicable system that can be used for cloud-based AM. The objective of this research is to develop a framework for designing a cyber additive manufacturing system that integrates an expert system with Internet of Things (IoT). An Artificial Neural Network (ANN) based expert system was implemented to classify input part designs based on CAD data and user inputs. Three ANN algorithms were trained on a knowledge base to identify optimal AM processes for different part designs. A two-stage model was used to enhance the prediction accuracy above 90% by increasing the number of input factors and datasets. A cyber interface was developed to query AM machine availability and resource capability using a Node-RED IoT device simulator. The dynamic AM machine identification system developed using an application programme interface (API) that integrates inputs from the smart algorithm and IoT interface for real-time predictions. This research establishes a foundation for the development of a cyber additive design for manufacturing system which can dynamically allocate digital designs to different AM techniques over the cyber network.

Toward an integrated dynamic defense system for strategic detecting attacks in cloud networks using stochastic game

In a complex network as a cloud computing environment, security is becoming increasingly based on deception techniques. To date, the static nature of cyber networks offers to adversaries good opportunities to systematically study the network environment, launch a cyber-attack effortlessly and wide-spread and finally defeat the target system. In order to resolve the limitations of the traditional security measures as intrusion prevention or detection systems, firewall, access list, etc., which did not change the attack surface and cannot avoid zero-days attacks, technics that provide dynamic defense, such virtual machine migration and honeypot should be deployed. Despite this, with a virtual machine migration technique, not all virtual machines’ migration between servers enhances security considerably. In this paper, we propose an integrated defense system combining virtual machine migration and honeypot. The effectiveness of the proposed system is discussed in terms of security policies. In addition, our proposed model determines the potential attack paths quantitatively then classifies them into two sub-sets: attack paths explored only and attack paths explored and exploited based on the black box intrusion steps. Thus, to model the interaction attacker–defender, the attack graph combined with the stochastic game theory is used. Finally, we carry out some numerical results to demonstrate the effectiveness of the proposed security game model.