•The current dynamics with bounded communication delays is proposed by resorting to the Boolean matrix STP.•The corresponding current estimate of possible reachable states are calculated by a matrix ...approach.•Networked opacity is investigated and its verification criterion is given in a concise algebraic form.•The algebraic approach well validates the impact of communication delay on the opacity of CPSs.
Networked finite state machines consider the delay factor in real-time communication networks, and the security has become an important research topic in cyber-physical systems (CPSs). In this brief paper, we explore the networked opacity of finite state machine with bounded communication delays. Firstly, the networked opacity is proposed from the perspective of security state reachability, and by use of the Boolean matrix semi-tensor product (STP), we introduce the reachability matrix with respect to all feasible events to give the current dynamics with bounded communication delays. Subsequently, based on the algebraic equation, we continue to discuss the corresponding current estimate of possible reachable states, which can be calculated by a matrix approach. Then, a more simple and effective verification criterion of networked opacity is derived by some matrix manipulations. Finally, a typical example is provided to validate the impact of communication delay on the opacity of CPSs, and our results contribute to deeply understanding the information security in the area of CPSs.
Identifying driving anomalies is of great significance for improving driving safety. The development of the Internet-of-Vehicle (IoV) technology has made it feasible to acquire big data from multiple ...vehicle sensors, and such big data play a fundamental role in identifying driving anomalies. Existing approaches are mainly based on either rules or supervised learning. However, such approaches often require labeled data, which are typically not available in big data scenarios. In addition, because driving behaviors differ under vehicle statuses (e.g., speed and gear position), to precisely model driving behaviors needs to fuse multiple sources of sensor data. To address these issues, in this paper, we propose SafeDrive, an online and status-aware approach, which does not require labeled data. From a historical dataset, SafeDrive statistically offline derives a state graph (SG) as a behavior model. Then, SafeDrive splits the online data stream into segments and compares each segment with the SG. SafeDrive identifies a segment that significantly deviates from the SG as an anomaly. We evaluate SafeDrive on a cloud-based IoV platform with over 29 000 real connected vehicles. The evaluation results demonstrate that SafeDrive is capable of identifying a variety of driving anomalies effectively from a large-scale vehicle data stream with an overall accuracy of 93%; such identified driving anomalies can be used to timely alert drivers to correct their driving behaviors.
Today, the verification of the control logic of automation projects is mainly a manual task during real commissioning phase on the physical installation. This involves a lot of risks towards possible ...damage and unanticipated delays in project completion. Virtual commissioning allows the verification to start earlier in the project timeline but is often also a manual task and requires a lot of human knowledge and expertise. This paper proposes a workflow to provide additional support to the automation engineer based on a 3D Digital Model that interacts with the real control logic. The digital model records all occurring states and transitions in the background and visualizes the state graph to highlight unexpected behaviour and to support troubleshooting. The proposed approach is validated on a test case confirming (1) the effectiveness of highlighting unexpected behaviour during programming phase and (2) the substantial reduction in real commissioning time. The added value of the approach is concluded, although a number of limitations still exist. Future research includes the validation of the approach on real industrial cases.
The control logic implemented in building automation systems (BAS) has a significant impact on the overall energy demand of the building. However, information on the control logic, if documented, is ...often concealed from further data integration and reuse in heterogeneous information silos using disparate data formats. In particular, existing data formats and information models offer limited support to describe control logic explicitly. Ontology-based modeling of the control logic of BAS can potentially result in a versatile source of information for information-driven processes to further increase the performance of technical equipment in a building. Therefore, we present a novel information model, CTRLont, which allows to formally specify the domain of control logic in BAS. We demonstrate the usefulness of the novel information model by using it as a knowledge base for automating rule-based verification of designed control logic in BAS. We successfully apply the methodology to a simple control of an air handling unit and indicate a number of future steps.
Due to the constant growth of cities in terms of population and territory, the volume of passenger traffic is sharply increasing. A lot of attention is paid to the study of transport infrastructure ...in scientific works, but the current problems of the functioning of various types of transport in large cities remain not fully covered. First of all this concerns the great uncertainty in the current information about the movement of transport and their work in the event of emergency situations. The article proposes to use the mathematical apparatus of the theory of queuing systems for the analysis of passenger traffic on urban transport. As an example, a graph of states for fixed-route taxis is constructed and ratios are obtained for evaluating the main indicators of the quality of their work. In the conditions of frequent changes in road situations and uncertainty of the conditions for obtaining information about the current situation, it is proposed to carry out traffic management using intelligent decisionmaking support tools. In this regard, it is advisable to use an approach based on fuzzy situational management. For this purpose, the article proposes an algorithm for fuzzy situational management, which is the basis of intelligent IDSS. . For an optimal transition from the current situation to a situation that meets the new operating conditions, in the sense of the selected criterion, it is proposed to use the dynamic programming method. Ref. 12, pic. 4.
Recently, the temporal constraint satisfiability is regarded as an important criterion in Web service composition to guarantee its timely completion. This leads to a new challenge in analyzing the ...compatibility of Web services under temporal constraints. The existing methods either do not consider message mismatches between services in a composition or suffer from state-space explosion by verifying a service composition model as a whole; or lack the ability to generate execution paths of each participating service. In this paper, we present a Petri net-based method to address these three issues in a holistic manner, and also in a modular way. Compared with the existing work, the proposed approach not only composes Web services by adding a mediation net to deal with message mismatches, but also checks the compatibility w.r.t. temporal constraints by generating modular timed state graphs. Furthermore, the reliable and usable execution paths that satisfy the timed compatibility can be derived to guide service execution and avoid any temporal exception.
In this paper, to solve the scheduling problem of discrete event systems modeled by Place-timed Petri nets, a timed state graph with time information is designed to abstract the state space of ...Place-timed Petri nets. The feasible firing transitions sequence with the minimal duration is kept in the timed state graph. Furthermore, a modified timed state space is further designed with smaller size than the timed state graph, and it also keeps the feasible firing transitions sequence with the minimal duration. By searching these timed state graphs, we can find the optimal solution, i.e., the feasible firing transitions sequence with minimal duration directly.
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