610 research outputs found

    Prediction of home energy consumption based on gradient boosting regression tree

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    Abstract Energy consumption prediction of buildings has drawn attention in the related literature since it is very complex and affected by various factors. Hence, a challenging work is accurately estimating the energy consumption of buildings and improving its efficiency. Therefore, effective energy management and energy consumption forecasting are now becoming very important in advocating energy conservation. Many researchers work on saving energy and increasing the utilization rate of energy. Prior works about the energy consumption prediction combine software and hardware to provide reasonable suggestions for users based on the analyzed results. In this paper, an innovative energy consumption prediction model is established to simulate and predict the electrical energy consumption of buildings. In the proposed model, the energy consumption data is more accurately predicted by using the gradient boosting regression tree algorithm. By comparing the performance index Root Mean Square Error of different prediction models through experiments it is shown that the proposed model obtains lower values on different testing data. More detailed comparison with other existing models through experiments show that the proposed prediction model is superior to other models in energy consumption prediction

    Reduced-Complexity Verification for K-Step and Infinite-Step Opacity in Discrete Event Systems

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    Opacity is a property that captures security concerns in cyber-physical systems and its verification plays a significant role. This paper investigates the verifications of K-step and infinite-step weak and strong opacity for partially observed nondeterministic finite state automata. K-step weak opacity is checked by constructing, for some states in the observer, appropriate state-trees, to propose a necessary and sufficient condition. Based on the relation between K-step weak and infinite-step weak opacity, a condition that determines when a system is not infinite-step weak opaque is presented. Regarding K-step and infinite-step strong opacity, we develop a secret-involved projected automaton, based on which we construct secret-unvisited state trees to derive a necessary and sufficient condition for K-step strong opacity. Furthermore, an algorithm is reported to compute a verifier that can be used to obtain a necessary and sufficient condition for infinite-step strong opacity. It is argued that, in some particular cases, the proposed methods achieve reduced complexity compared with the state of the art

    Verification and Enforcement of Strong State-Based Opacity for Discrete-Event Systems

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    In this paper, we investigate the verification and enforcement of strong state-based opacity (SBO) in discrete-event systems modeled as partially-observed (nondeterministic) finite-state automata, including strong K-step opacity (K-SSO), strong current-state opacity (SCSO), strong initial-state opacity (SISO), and strong infinite-step opacity (Inf-SSO). They are stronger versions of four widely-studied standard opacity notions, respectively. We firstly propose a new notion of K-SSO, and then we construct a concurrent-composition structure that is a variant of our previously-proposed one to verify it. Based on this structure, a verification algorithm for the proposed notion of K-SSO is designed. Also, an upper bound on K in the proposed K-SSO is derived. Secondly, we propose a distinctive opacity-enforcement mechanism that has better scalability than the existing ones (such as supervisory control). The basic philosophy of this new mechanism is choosing a subset of controllable transitions to disable before an original system starts to run in order to cut off all its runs that violate a notion of strong SBO of interest. Accordingly, the algorithms for enforcing the above-mentioned four notions of strong SBO are designed using the proposed two concurrent-composition structures. In particular, the designed algorithm for enforcing Inf-SSO has lower time complexity than the existing one in the literature, and does not depend on any assumption. Finally, we illustrate the applications of the designed algorithms using examples.Comment: 30 pages, 20 figures, partial results in Section 3 were presented at IEEE Conference on Decision and Control, 2022. arXiv admin note: text overlap with arXiv:2204.0469

    Verification of Joint Current-State Opacity Using Petri Nets

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    A discrete event system (DES) is said to be opaque if a predefined secret can never be exposed to an intruder who can observe its evolution. In this paper we consider a problem of joint current-state opacity for a system modeled by a Petri net and monitored by multiple local intruders, each of which can partially observe the behavior of the system. The intruders can synchronously communicate to a coordinator the state estimate they have computed, but not their observations. We demonstrate that the verification of this property can be efficiently addressed by using a compact representation of the reachability graph, called basis reachability graph (BRG), as it avoids the need for exhaustive enumeration of the reachability space. A joint BRG-observer is constructed to analyze joint current- state opacity under such a coordinated decentralized architecture
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