Cyber-physical Systems Applications Research Articles

Guest Editorial: Special Section on Resilience, Reliability, and Security in Cyber–Physical Systems

Cyber-physical systems (CPS) refers to the integrative system consisting of interconnected computing and control devices interacting with the physical infrastructure via sensors and actuators. Recently, there is a swift growth of CPSs ranging from smart grids to smart buildings, robotics, and other industrial control systems. They have formed the keystone of the sustainable growth of the economy, manufacturing, and smart and connected communities. Due to extensive applications of CPSs, their resilience, reliability, and security are paramount. Many factors, however, pose significant threats to CPSs and lead to high economic losses and social impacts. Software defects also make CPSs vulnerable to security attacks and coordinated cyber and physical attacks. To address this issue, emerging technologies and methods for understanding and improving the resilience, reliability, and security of CPSs are needed. This Special Section aims to provide a platform to help define, understand, and quantify the resilience, reliability, and security of CPSs.

Cyber Physical System in the industry

The Industrial Revolution 4.0 greatly affects the activity patterns of human life. Many sectors are feeling the impact of the industrial revolution 4.0, especially industry and education sectors. One of the technologies developed in the era of the Industrial Revolution 4.0, namely Cyber Physical System. This technology that integrates communications, control, and physically through the Internet. This paper was prepared aims to determine the model and the application of Cyber Physical Systems in the industry. The method used in the preparation of this paper, by reviewing the literature in journals that are in the range of 2014 - 2019. The search results and study, there are different models and ways of working are applied Cyber Physical Systems in industry. Based on these results of the study, it is hoped that alternative CPS models can be applied in the same field or developed in other relevant fields.

ТРЕБОВАНИЯ И НОРМЫ ИСПЫТАНИЙ ПО РАДИАЦИОННОЙ СТОЙКОСТИ ИНТЕГРАЛЬНЫХ СХЕМ К ЭФФЕКТАМ ВОЗДЕЙСТВИЯ ТЯЖЕЛЫХ ЗАРЯЖЕННЫХ ЧАСТИЦ

The paper presents an analysis of existing approaches to estimation of single event rate (SER) in integrated circuits under effects of charged particles of space radiation environment. These issues are of significant importance in the light of the expansion of the scope of practical application of cyber-physical control systems for space objects, since it is mainly due to the SER that information is lost in the register elements and in the memory cells of the electronic blocks of spacecraft. It is shown that existing models based on energy deposition in fixed sensitive volume are not applicable for SER estimations in case of high threshold linear energy transfer (LET) values. An alternative approach is proposed. It is based on diffusion charge collection model, which can be used to estimate the SER cross-sections in isotropic particle field. A universal dependence for SER estimation in integral circuits (ICs) at geostationary orbit is proposed and used as a basis for establishing classification of devices based on hardness assurance levels. The obtained results provide the grounds for setting test requirements that has to be met during single event effects testing of ICs.

Automated adaptive façade functions in practice - Case studies on office buildings

The study examines the existing technical basis in building practice for the application of cyber-physical systems on the façade. The associated intelligent cooperation of automated adaptive façade functions, inspired by intelligent technical systems in industry 4.0, offers a potential for the overall building performance. By the type and scope of automations already introduced today, façade functions are identified that offer special potential for consideration in a cyber-physically implemented façade. The investigation represents a multiple case study analysis in which office façades in Germany are examined. Data is collected from literature, expert interviews and field investigations. The evaluation is carried out in a single case analysis and a following cross-case analysis, in which patterns and dependencies in the joint implementation of automated and adaptive façade functions are identified. The study found that especially sun-related functions are implemented adaptively, often in combination with ventilation and the heating and cooling support function.

Personalized Messaging Based on Dynamic Context Assessment: Application in An Informing Cyber-Physical System

Hazard-intense applications of cyber-physical systems (CPSs), such as the evacuation of a building on fire, require personalized informing on the basis of a real-time assessment of dynamic context. In this paper, a context-dependent message construct

Blockchain-based shared manufacturing in support of cyber physical systems: concept, framework, and operation

Abstract Shared Manufacturing (SharedMfg), a Peer-to-Peer (P2P)-based resource sharing paradigm boosted by the wide-spread of sharing economy, servitization and Internet of things, tends to massively extend the scope of resource sharing in both vertical and horizontal directions, and as a consequence, it amplifies a credibility gap in the manufacturing area. To respond to this problem, and meanwhile, promoting the SharedMfg, blockchain is attempted to integrate into the SharedMfg. Hence, this paper proposes the Blockchain-based SharedMfg (BSM) framework in support of the application of Cyber Physical Systems (CPS). At the same time, Resource Operation Blockchain (ROB) is constructed for the core operation of BSM framework, which carries out on the basis of a consensus mechanism (i.e., Proof-of-Participation) and a Smart Contract Network (SCN), to facilitate the P2P-based resource sharing paradigm. A prototype system is implemented by the Ethereum framework together with discussions to validate the feasibility of ROB. In brief, BSM framework complementarily combines the blockchain and SharedMfg, beneficial to promote both modes.

Formalization of continuous Fourier transform in verifying applications for dependable cyber-physical systems

Continuous Fourier transform (CFT) is widely used and is often directly applied in cyber-physical systems (CPS) without checking its preconditions. This inevitably leads to unexpected defects and even errors. Thus, verification is necessary for the CFT-based engineering design to ensure a dependable cyber physical system. HOL4 (Higher Order Logic 4) is a formal theorem prover that prevails in software and hardware verification. However, there is no CFT theorem library in current HOL4. In this paper, the definition and some frequently used properties of CFT are formalized and verified in HOL4. Based on this, we formally model a basic theorem library of CFT. As a case study, the CFT library is employed to verify the frequency response of an RLC circuit, which is a critical application for dependable CPS. The formalization of the CFT and its properties and the construction of the formal CFT theorem library can effectively extend the function of the HOL4 system. The obtained formal results can be applied in various CFT-based cyber-physical systems.

A Survey of Blockchain Enabled Cyber-Physical Systems.

Cyber-physical systems (CPS) is a setup that controls and monitors the physical world around us. The advancement of these systems needs to incorporate an unequivocal spotlight on making these systems efficient. Blockchains and their inherent combination of consensus algorithms, distributed data storage, and secure protocols can be utilized to build robustness and reliability in these systems. Blockchain is the underlying technology behind bitcoins and it provides a decentralized framework to validate transactions and ensure that they cannot be modified. By distributing the role of information validation across the network peers, blockchain eliminates the risks associated with a centralized architecture. It is the most secure validation mechanism that is efficient and enables the provision of financial services, thereby giving users more freedom and power. This upcoming technology provides internet users with the capability to create value and authenticate digital information. It has the capability to revolutionize a diverse set of business applications, ranging from sharing economy to data management and prediction markets. In this paper, we present a holistic survey of various applications of CPS where blockchain has been utilized. Smart grids, health-care systems, and industrial production processes are some of the many applications that can benefit from the blockchain technology and will be discussed in the paper.

Theoretical foundations and applications of cyber-physical systems: a literature review

PurposeThe purpose of this paper is to review the current research on theoretical foundations and applications for CPS from 2017 to 2019 including the applications in library.Design/methodology/approachThis paper is designed in six parts as Introduction, Literature review, Theoretical foundations of CPS, Applications of CPS, CPS’s application in library and Conclusion. The authors review 70 papers and classify them as the above six parts. The authors collected 70 papers from 2017 to 2019 in the academic databases.FindingsThis paper reviews 70 papers regarding theoretical foundations and applications for CPS from 2017 to 2019 in the academic databases aiming to provide scholars and practitioners with a comprehensive overview. The contents of the papers in each research category are summarized from theoretical foundations and applications including the CPS applications in library.Originality/valueA main contribution of this review paper is that it summarizes the current state-of-the-art theoretical foundations and applications for CPS and in libraries systematically.

Thinking- Skins

Thinking- Skins

A Survey on Decentralized Consensus Mechanisms for Cyber Physical Systems

Modern industry 4.0 applications are shifting towards decentralized automation of computing and cyber-physical systems (CPS), which necessitates building a robust, secure, and efficient system that performs complex interactions with other physical processes. To handle complex interactions in CPS, trust and consensus among various stakeholders is a prime concern. In a similar direction, consensus algorithms in blockchain have evolved over the years that focus on building smart, robust, and secure CPS. Thus, it is imperative to understand the key components, functional characteristics, and architecture of different consensus algorithms used in CPS. Many consensus algorithms exist in the literature with a specified set of functionalities, performance, and computing services. Motivated from these facts, in this survey, we present a comprehensive analysis of existing state-of-the-art consensus mechanisms and highlight their strength and weaknesses in decentralized CPS applications. In the first part, we present the scope of the proposed survey and identify gaps in the existing surveys. Secondly, we present the review method and objectives of the proposed survey based on research questions that address the gaps in existing studies. Then, we present a solution taxonomy of decentralized consensus mechanisms for various CPS applications. Then, open issues and challenges are also discussed in deploying various consensus mechanisms in the CPS with their merits and demerits. The proposed survey will act as a road-map for blockchain developers and researchers to evaluate and design future consensus mechanisms, which helps to build an efficient CPS for industry 4.0 stakeholders.

Smart Contract Privacy Protection Using AI in Cyber-Physical Systems: Tools, Techniques and Challenges

Applications of Blockchain (BC) technology and Cyber-Physical Systems (CPS) are increasing exponentially. However, framing resilient and correct smart contracts (SCs) for these smart application is a quite challenging task because of the complexity associated with them. SC is modernizing the traditional industrial, technical, and business processes. It is self-executable, self-verifiable, and embedded into the BC that eliminates the need for trusted third-party systems, which ultimately saves administration as well as service costs. It also improves system efficiency and reduces the associated security risks. However, SCs are well encouraging the new technological reforms in Industry 4.0, but still, various security and privacy challenges need to be addressed. In this paper, a survey on SC security vulnerabilities in the software code that can be easily hacked by a malicious user or may compromise the entire BC network is presented. As per the literature, the challenges related to SC security and privacy are not explored much by the authors around the world. From the existing proposals, it has been observed that designing a complex SCs cannot mitigate its privacy and security issues. So, this paper investigates various Artificial Intelligence (AI) techniques and tools for SC privacy protection. Then, open issues and challenges for AI-based SC are analyzed. Finally, a case study of retail marketing is presented, which uses AI and SC to preserve its security and privacy.

Formalization of target and assessment of quality of the cyber-physical control systems for emissions reduction technologies

Monitoring and inventory is a necessary but not sufficient condition to reduce emissions in the energy and industry. The ultimate task of controlling air purification technologies in combination with monitoring is effectively achieved while minimizing the human factor. The creation and application of cyber-physical technology management systems provide a solution to a set of related environmental problems. In addition, the development of models based on cyber-physical systems forms new requirements for the development of technologies for their creation. A special feature of such technologies is close interaction between computing methods with design and production facilities. These issues have not been sufficiently reflected in publications. The article presents the target setting for the creation of cyber-physical technology control systems based on local laws of preservation and the decomposition of the target into macroscopic quality assessments. A mathematical model and methods of quality assessment at the life cycle stages of such systems based on recalculation of probability densities of a priori data are presented. Examples of cyber-physical emission reduction systems in the energy and industry developed under the nature-technology concept are given.

V-nets, new formalism to manage diagnosis problems in Cyber-Physical Systems (CPS) and industrial applications

Abstract This article presents the new formalism called V-nets as a tool to deal with diagnosis problems of Cyber-Physical Systems (CPS) and industrial processes, situations such as simultaneity of events, partial recognition of event sequences, and false positives. Cyber-Physical Systems (CPS) and industrial processes demand the reliability of its supervisory and control elements, especially in fault detection applications. There are many scenarios in which typical formal models of DES (Discrete Event Systems) do not guarantee by itself a reliable analysis of the circumstances. The simultaneous occurrence of discrete events and false positives are circumstances examined in this paper and the new formalism V-nets is presented as a new tool that can manage the situations described.

Driven by Data or Derived Through Physics? A Review of Hybrid Physics Guided Machine Learning Techniques With Cyber-Physical System (CPS) Focus

A multitude of cyber-physical system (CPS) applications, including design, control, diagnosis, prognostics, and a host of other problems, are predicated on the assumption of model availability. There are mainly two approaches to modeling: Physics/Equation based modeling (Model-Based, MB) and Machine Learning (ML). Recently, there is a growing consensus that ML methodologies relying on data need to be coupled with prior scientific knowledge (or physics, MB) for modeling CPS. We refer to the paradigm that combines MB approaches with ML as hybrid learning methods. Hybrid modeling (HB) methods is a growing field within both the ML and scientific communities, and are recognized as an important emerging but nascent area of research. Recently, several works have attempted to merge MB and ML models for the complete exploitation of their combined potential. However, the research literature is scattered and unorganized. So, we make a meticulous and systematic attempt at organizing and standardizing the methods of combining ML and MB models. In addition to that, we outline five metrics for the comprehensive evaluation of hybrid models. Finally, we conclude by shedding some light on the challenges of hybrid models, which we, as a research community, should focus on for harnessing the full potential of hybrid models. An additional feature of this survey is that the hybrid modeling work has been discussed with a focus on modeling cyber-physical systems.

Differential Privacy Techniques for Cyber Physical Systems: A Survey

Modern cyber physical systems (CPSs) has widely being used in our daily lives because of development of information and communication technologies (ICT).With the provision of CPSs, the security and privacy threats associated to these systems are also increasing. Passive attacks are being used by intruders to get access to private information of CPSs. In order to make CPSs data more secure, certain privacy preservation strategies such as encryption, and k-anonymity have been presented in the past. However, with the advances in CPSs architecture, these techniques also needs certain modifications. Meanwhile, differential privacy emerged as an efficient technique to protect CPSs data privacy. In this paper, we present a comprehensive survey of differential privacy techniques for CPSs. In particular, we survey the application and implementation of differential privacy in four major applications of CPSs named as energy systems, transportation systems, healthcare and medical systems, and industrial Internet of things (IIoT). Furthermore, we present open issues, challenges, and future research direction for differential privacy techniques for CPSs. This survey can serve as basis for the development of modern differential privacy techniques to address various problems and data privacy scenarios of CPSs.

CONFIDENTIALITY OF CYBER-PHYSICAL SYSTEMS USING EVENT-BASED CRYPTOGRAPHY

Abstract One of the most important challenges for the application of cyber-physical systems (CPS) in smart industries is ensuring its security against cyber attacks. In this paper, we consider that the CPS is abstracted as a Discrete-Event System (DES), and we consider cyber attacks where the intruder eavesdrops the sensor communication channel to detect the occurrence of a sequence in the secret behavior of the system. In order to prevent the attacker from getting information from the sensor channel, we introduce a new cryptographic scheme based on events called event-based cryptography. We also define the property of confidentiality of DES, present a necessary and sufficient condition for ensuring this property, and propose a verification test.

Integrated moving target defense and control reconfiguration for securing Cyber-Physical systems

With the increasingly connected nature of Cyber-Physical Systems (CPS), new attack vectors are emerging that were previously not considered in the design process. Specifically, autonomous vehicles are one of the most at risk CPS applications, including challenges such as a large amount of legacy software, non-trusted third party applications, and remote communication interfaces. With zero day vulnerabilities constantly being discovered, an attacker can exploit such vulnerabilities to inject malicious code or even leverage existing legitimate code to take over the cyber part of a CPS. Due to the tightly coupled nature of CPS, this can lead to altering physical behavior in an undesirable or devastating manner. Therefore, it is no longer effective to reactively harden systems, but a more proactive approach must be taken. Moving target defense (MTD) techniques such as instruction set randomization (ISR), and address space randomization (ASR) have been shown to be effective against code injection and code reuse attacks. However, these MTD techniques can result in control system crashing which is unacceptable in CPS applications since such crashing may cause catastrophic consequences. Therefore, it is crucial for MTD techniques to be complemented by control reconfiguration to maintain system availability in the event of a cyber-attack. This paper addresses the problem of maintaining system and security properties of a CPS under attack by integrating moving target defense techniques, as well as detection, and recovery mechanisms to ensure safe, reliable, and predictable system operation. Specifically, we consider the problem of detecting code injection as well as code reuse attacks, and reconfiguring fast enough to ensure the safety and stability of autonomous vehicle controllers are maintained. By using MTD such as ISR, and ASR, our approach provides the advantage of preventing attackers from obtaining the reconnaissance knowledge necessary to perform code injection and code reuse attacks, making sure attackers can’t find vulnerabilities in the first place. Our system implementation includes a combination of runtime MTD utilizing AES 256 ISR and fine grained ASR, as well as control management that utilizes attack detection, and reconfiguration capabilities. We evaluate the developed security architecture in an autonomous vehicle case study, utilizing a custom developed hardware-in-the-loop testbed.

Real-time carbon emission monitoring in prefabricated construction

The problem of carbon emissions from the construction industry should be a serious concern, because it contributes a very large share of the overall GHG emissions. However, because of traditional construction modes, most previous research has focused on forecasting ex-post analysis of carbon emissions, and few efforts have concentrated on real-time analysis, the lack of which leads to deficiencies in carbon emission control. The industrial transformation of construction has created opportunities for improvement, and similarly the developments in information technology, notably cyber-physical systems (CPS), have shown the potential to contribute to solving this problem. In several other industries, the application of CPS has made significant progress. To strengthen the monitoring and analysis of carbon emissions in prefabricated construction and thus prevent an excessive impact on the environment, this study proposes a real-time carbon emission monitoring (CEM) system for the whole industrial chain of prefabricated construction. To achieve this aim, previous studies on carbon monitoring in the construction industry are reviewed to investigate the applicability of CPS to CEM systems. The functionality of the system is designed according to the requirements of different end users, and five types of hardware are developed for automated data acquisition in real time. In addition, for better utilization of the monitoring system, three different data presentation platforms are developed for customers (desktop platform, browser, and smartphone app). The system can successfully perform real-time monitoring of carbon emissions，which is useful in preventing additional emissions.

An inaudible voice attack to context-based device authentication in smart IoT systems

Abstract As a typical application of Cyber-physical systems (CPS), a smart Internet of Things (IoT) system integrates computation, networking, and physical processes from embedded computing devices. To protect the confidentiality and authenticity of IoT systems, device authentication/pairing is a critical operation for securing networking and communication. Context-based pairing aims to provide more practical methods of pairing, using the common events in the same trust domain as the basis for device authentication. However, the inaccuracy of event recognition and context noise sensitivity are inherent flaws that greatly affect the robustness and efficiency of these approaches. In this paper, we analyze the weakness of context-based pairing methods and present a jamming-based attack named Pairjam, which interferes with the device authentication of these context-based device pairing methods. Due to the unknown noise threshold in signal detection, we design two attack model and validate that both attacks lead to misclassified of attack signal and decrease the similarity of fingerprint. The experiment results demonstrate that Pairjam can successfully disturb the device pairing by interfere with the fingerprint similarity of the microphone-equipped devices with other non-acoustic IoT devices.