Biblio

Industrial IoT (IIoT) is a specialized subset of IoT which involves the interconnection of industrial devices with ubiquitous control and intelligent processing services to improve industrial system's productivity and operational capability. In essence, IIoT adapts a use-case specific architecture based on RFID sense network, BLE sense network or WSN, where heterogeneous industrial IoT devices can collaborate with each other to achieve a common goal. Nonetheless, most of the IIoT deployments are brownfield in nature which involves both new and legacy technologies (SCADA (Supervisory Control and Data Acquisition System)). The merger of these technologies causes high degree of cross-linking and decentralization which ultimately increases the complexity of IIoT systems and introduce new vulnerabilities. Hence, industrial organizations becomes not only vulnerable to conventional SCADA attacks but also to a multitude of IIoT specific threats. However, there is a lack of understanding of these attacks both with respect to the literature and empirical evaluation. As a consequence, it is infeasible for industrial organizations, researchers and developers to analyze attacks and derive a robust security mechanism for IIoT. In this paper, we developed a multi-layer taxonomy of IIoT attacks by considering both brownfield and greenfield architecture of IIoT. The taxonomy consists of 11 layers 94 dimensions and approximately 100 attack techniques which helps to provide a holistic overview of the incident attack pattern, attack characteristics and impact on industrial system. Subsequently, we have exhibited the practical relevance of developed taxonomy by applying it to a real-world use-case. This research will benefit researchers and developers to best utilize developed taxonomy for analyzing attack sequence and to envisage an efficient security platform for futuristic IIoT applications.

Eddy Current Pulsed Thermography (ECPT) is widely used in Nondestructive Testing (NDT) of metal defects where the defect information is sometimes affected by coil noise and edge noise, therefore, it is necessary to segment the ECPT image sequences to improve the detection effect, that is, segmenting the defect part from the background. At present, the methods widely used in ECPT are mostly based on matrix decomposition theory. In fact, tensor decomposition is a new hotspot in the field of image segmentation and has been widely used in many image segmentation scenes, but it is not a general method in ECPT. This paper analyzes the feasibility of the usage of tensor decomposition in ECPT and designs several experiments on different samples to verify the effects of two popular tensor decomposition algorithms in ECPT. This paper also compares the matrix decomposition methods and the tensor decomposition methods in terms of treatment effect, time cost, detection success rate, etc. Through the experimental results, this paper points out the advantages and disadvantages of tensor decomposition methods in ECPT and analyzes the suitable engineering application scenarios of tensor decomposition in ECPT.

Tensile residual stresses combined with an applied tensile stress can reduce the reliability of steel components. Nondestructive evaluation of residual stress is thus important to avoid unintended fatigue or cracking. Because magnetic hysteresis properties of ferromagnetic materials are sensitive to stress, nondestructive evaluation of residual stress through magnetic properties can be expected. The spatial mapping of local magnetic hysteresis properties becomes possible by using the acoustically stimulated electromagnetic (ASEM) method and the tensile stress dependence of the hysteresis properties has been investigated in steel. It is found that the coercivity Hc and the remanent magnetization signal Vr monotonically decrease with increasing the tensile stress. In this work, we verified the detection of residual stresses through the ASEM response in a welded steel plate. Tensile stresses are intentionally introduced on the opposite side of the partially welded face by controlling welding temperatures. We found that Hc and Vr clearly decrease in the welded region, suggesting that the presence of tensile residual stresses is well detected by the hysteresis parameters.

Supply Chain wide proactive risk management based on real-time risk related information transparency is required to increase the security of modern, volatile supply chains. At this time, none or only limited empirical/objective information about digitalization benefits for supply chain risk management is available. A method is needed, which draws conclusion on the estimation of costs and benefits of digitalization initiatives. The paper presents a flexible simulation based approach for assessing digitalization scenarios prior to realization. The assessment approach is integrated into a framework and its applicability will be shown in a case study of a German steel producer, evaluating digitalization effects on the Mean Lead time-at-risk.