70,463 research outputs found

    Class-based storage location assignment : an overview of the literature

    Get PDF
    Storage, per se, is not only an important process in a warehouse, also it has the greatest influence on the most expensive one, i.e., order picking. This study aims to give a literature overview on class-based storage location assignment (CBSLAP). In this paper, we discuss storage policies and present a classification of storage location assignment problem. Next, different configuration of classes are presented. We identify the research gaps in the literature and conclude with promising future research directions

    Optimal Attack against Cyber-Physical Control Systems with Reactive Attack Mitigation

    Full text link
    This paper studies the performance and resilience of a cyber-physical control system (CPCS) with attack detection and reactive attack mitigation. It addresses the problem of deriving an optimal sequence of false data injection attacks that maximizes the state estimation error of the system. The results provide basic understanding about the limit of the attack impact. The design of the optimal attack is based on a Markov decision process (MDP) formulation, which is solved efficiently using the value iteration method. Using the proposed framework, we quantify the effect of false positives and mis-detections on the system performance, which can help the joint design of the attack detection and mitigation. To demonstrate the use of the proposed framework in a real-world CPCS, we consider the voltage control system of power grids, and run extensive simulations using PowerWorld, a high-fidelity power system simulator, to validate our analysis. The results show that by carefully designing the attack sequence using our proposed approach, the attacker can cause a large deviation of the bus voltages from the desired setpoint. Further, the results verify the optimality of the derived attack sequence and show that, to cause maximum impact, the attacker must carefully craft his attack to strike a balance between the attack magnitude and stealthiness, due to the simultaneous presence of attack detection and mitigation

    Damage identification in structural health monitoring: a brief review from its implementation to the Use of data-driven applications

    Get PDF
    The damage identification process provides relevant information about the current state of a structure under inspection, and it can be approached from two different points of view. The first approach uses data-driven algorithms, which are usually associated with the collection of data using sensors. Data are subsequently processed and analyzed. The second approach uses models to analyze information about the structure. In the latter case, the overall performance of the approach is associated with the accuracy of the model and the information that is used to define it. Although both approaches are widely used, data-driven algorithms are preferred in most cases because they afford the ability to analyze data acquired from sensors and to provide a real-time solution for decision making; however, these approaches involve high-performance processors due to the high computational cost. As a contribution to the researchers working with data-driven algorithms and applications, this work presents a brief review of data-driven algorithms for damage identification in structural health-monitoring applications. This review covers damage detection, localization, classification, extension, and prognosis, as well as the development of smart structures. The literature is systematically reviewed according to the natural steps of a structural health-monitoring system. This review also includes information on the types of sensors used as well as on the development of data-driven algorithms for damage identification.Peer ReviewedPostprint (published version

    CERN openlab Whitepaper on Future IT Challenges in Scientific Research

    Get PDF
    This whitepaper describes the major IT challenges in scientific research at CERN and several other European and international research laboratories and projects. Each challenge is exemplified through a set of concrete use cases drawn from the requirements of large-scale scientific programs. The paper is based on contributions from many researchers and IT experts of the participating laboratories and also input from the existing CERN openlab industrial sponsors. The views expressed in this document are those of the individual contributors and do not necessarily reflect the view of their organisations and/or affiliates

    Dynamic Capabilities and their Indirect Impact on Firm Performance

    Get PDF
    This paper investigates the relationship between dynamic capabilities and firm performance. In particular it addresses the question of whether dynamic capabilities impact directly or indirectly on performance. Using data from manufacturing firms, the paper articulates and measures dynamic capabilities as a multi-dimensional construct with three underlying factors: coordination, learning and strategic competitive response. Then, structural equation modelling is employed to explore the relationships among dynamic capabilities, functional competences and firm performance. Empirical findings suggest that dynamic capabilities are antecedents to functional competences which in turn have a significant effect on performance. Direct effects on performance are found to be insignificant. Furthermore, similar effects seem to hold for both higher and lower levels of environmental dynamism. Theoretical and practical implications are discussed.Dynamic capabilities; functional competences; firm performance; indirect impact
    corecore