| 41. |
- Butun, Ismail, et al.
(author)
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Detecting Intrusions in Cyber-Physical Systems of Smart Cities : Challenges and Directions
- 2019
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In: Secure Cyber-Physical Systems for Smart Cities. - Hershey, USA : IGI Global. - 9781522571896 ; , s. 74-102
-
Book chapter (peer-reviewed)abstract
- Interfacing the smart cities with cyber-physical systems (CPSs) improves cyber infrastructures while introducing security vulnerabilities that may lead to severe problems such as system failure, privacy violation, and/or issues related to data integrity if security and privacy are not addressed properly. In order for the CPSs of smart cities to be designed with proactive intelligence against such vulnerabilities, anomaly detection approaches need to be employed. This chapter will provide a brief overview of the security vulnerabilities in CPSs of smart cities. Following a thorough discussion on the applicability of conventional anomaly detection schemes in CPSs of smart cities, possible adoption of distributed anomaly detection systems by CPSs of smart cities will be discussed along with a comprehensive survey of the state of the art. The chapter will discuss challenges in tailoring appropriate anomaly detection schemes for CPSs of smart cities and provide insights into future directions for the researchers working in this field.
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| 42. |
- Degen, René, 1994-
(author)
-
Urban Virtual Test Field for HighlyAutomated Vehicle Systems
- 2021
-
Licentiate thesis (other academic/artistic)abstract
- Autonomous driving is one of the key technologies for increasing road safetyand reducing traffic volumes. Therefore, science and industry are workingtogether on new innovative solutions in this field of technology. One importantcomponent in this context is the approval and testing of new solution concepts,with special focus on the ones for urban environments. Not only because ofthe high diversity of traffic situations, but also because of the close contactbetween vulnerable road users (VRU) and automated vehicles.In the course of this work, a novel approach for testing automated drivingfunctions and vehicle systems in urban environments is presented. The goal isto create a safe and valid environment in which the automated vehicle and theVRU can meet and interact. The basis is a highly realistic virtual model of acity center. The physical behavior of the vehicle and VRU is recorded usingmeasurement technology and transferred to the virtual city model.Based on representative urban traffic scenarios, the functionality of the urbantest field is investigated from various points of view. Thereby, the focus is onreal-time capability and the quality of interaction between the vehicle and theVRU.The investigations show that both the real-time capability and the interactionpossibilities could be demonstrated. Further, the developed methodologies aresuitable for real time applications.
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| 43. |
- Eklund, Johan, 1966-, et al.
(author)
-
Tuning SCTP failover for carrier grade telephony signaling
- 2010
-
In: Computer Networks. - : Elsevier BV. - 1389-1286 .- 1872-7069. ; 54:1, s. 133-149
-
Journal article (peer-reviewed)abstract
- The Stream Control Transmission Protocol (SCTP) has not only been selected as the signaling transport protocol of choice in IETF SIGTRAN, the architecture that bridges circuit-switched and IP-based mobile core networks, but also plays a pivotal role in SAE/LTE, the next-generation UMTS/HSPA networks. To meet the redundancy requirements of telecom signaling traffic, SCTP includes a failover mechanism that enables rerouting of traffic from an unreachable network path to a backup path. However, the recommendations provided by IETF on how to configure the SCTP failover mechanism to meet telecom signaling requirements are kept quite general and leave much of the tuning to the telecom equipment vendor and/or operator. Several works by us and others have been carried out to study the effect of different SCTP parameters on the failover performance. The main contribution of this paper is that it gives a coherent treatment of how to configure the SCTP failover mechanism for carrier-grade telephony signaling, and provides practically usable configuration recommendations. The paper also discusses an alternate or complementary way of optimizing the SCTP failover mechanism by relaxing the exponential backoff that foregoes a retransmission timeout in SCTP. Some results showing significantly reduced failover times by use of this mechanism, with only marginal deteriorating effects on a signaling network, are discussed and analyzed in the paper. (C) 2009 Elsevier B.V. All rights reserved.
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| 44. |
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| 45. |
- Ippolito, M. G., et al.
(author)
-
Damping Provision by Different Virtual Synchronous Machine Schemes
- 2020
-
In: Proceedings - 2020 IEEE International Conference on Environment and Electrical Engineering and 2020 IEEE Industrial and Commercial Power Systems Europe, EEEIC / I and CPS Europe 2020.
-
Conference paper (peer-reviewed)abstract
- The adoption of virtual synchronous machine (VSM) schemes for the control of power converters is gaining more and more attention both in academia and industry. The VSM control strategies fall into the category of grid-forming converter controls, and they are intended for a range of different applications, providing specific services and different kinds of support to the grid. The paper investigates the possibility of damping provision to the system by VSM power converters. Different schemes are considered and compared, showing the opportunity of the investigated solutions through combined modal and time domain analyses. A specific modification of the power synchronization loop is recognized as the most suitable method to contain the power oscillations and increase the damping level in the system.
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| 46. |
- Ippolito, M. G., et al.
(author)
-
Extension and Tuning of Virtual Synchronous Machine to Avoid Oscillatory Instability in Isolated Power Networks
- 2020
-
In: 12th AEIT International Annual Conference, AEIT 2020.
-
Conference paper (peer-reviewed)abstract
- The risk of oscillatory instability introduced by virtual synchronous machines (VSM) control in isolated power networks is investigated. The considered control is a common scheme widely studied in literature, in several configurations and for different case studies. The impact of the VSM control on the system stability is examined for the existing power network of a Mediterranean island. The VSM control is implemented within the power converters interfacing the energy storage systems (ESS) installed in the network. Simulations and analysis show the occurrence of oscillatory instability in the system, with the ESS-VSM and the synchronous machines of the network progressively swinging against each other. The reasons of the instability are identified as the lack of damping in the system and the adverse interaction between the VSM converter control and the synchronous machine dynamics. The possibility of extending the VSM control with a corrective action for the stabilization of the system is analyzed and discussed. A proper tuning procedure of the extended control is also provided.
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| 47. |
- Kalsson, Stefan, et al.
(author)
-
Eavesdropping G.652 vs. G.657 fibres: a performance comparison
- 2022
-
In: 2022 International Conference on Optical Network Design and Modeling, ONDM 2022.
-
Conference paper (peer-reviewed)abstract
- With increasing dependence on secure access to digital services and the ultra-high traffic volumes running on the optical fibre communication infrastructure, the protection of this infrastructure from eavesdropping is extremely important, especially in defense and military applications. The G.657 fibre is recommended to be deployed in in-building installations for its improved bending performance compared to the G.652 fibre. However, the easiness to be eavesdropped, which reflects the security level of those two types of fibres has not yet been investigated. In this paper, we study the eavesdropping of fibre from a system perspective and compare the bending property of G.652 and G.657 fibres. The measurement results show that G.657 can be bent sharper than G.652 without causing any additional power attenuation at the receiver. This indicates that the so-called bending-insensitive G.657 fibre can potentially be eavesdropped more easily than their G.652 counterparts. The paper also shows that the power level measurement at the receiver may not be sufficient for unambiguous eavesdrop detection.
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| 48. |
- Khan, Suleman, et al.
(author)
-
AKAASH: A realizable authentication, key agreement, and secure handover approach for controller-pilot data link communications
- 2023
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In: International Journal of Critical Infrastructure Protection. - : ELSEVIER. - 1874-5482 .- 2212-2087. ; 42
-
Journal article (peer-reviewed)abstract
- Controller-Pilot Data Link Communications (CPDLC) are rapidly replacing voice-based Air Traffic Control (ATC) communications worldwide. Being digital, CPDLC is highly resilient and bandwidth efficient, which makes it the best choice for traffic-congested airports. Although CPDLC initially seems to be a perfect solution for modern-day ATC operations, it suffers from serious security issues. For instance, eavesdropping, spoofing, man-in-the-middle, message replay, impersonation attacks, etc. Cyber attacks on the aviation communication network could be hazardous, leading to fatal aircraft incidents and causing damage to individuals, service providers, and the aviation industry. Therefore, we propose a new security model called AKAASH, enabling several paramount security services, such as efficient and robust mutual authentication, key establishment, and a secure handover approach for the CPDLC-enabled aviation communication network. We implement the approach on hardware to examine the practicality of the proposed approach and verify its computational and communication efficiency and efficacy. We investigate the robustness of AKAASH through formal (proverif) and informal security analysis. The analysis reveals that the AKAASH adheres to the CPDLC standards and can easily integrate into the CPDLC framework.
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| 49. |
- Lavassani, Mehrzad
(author)
-
Evolving Industrial Networks : Data-Driven Network Traffic Modelling and Monitoring
- 2023
-
Doctoral thesis (other academic/artistic)abstract
- The concept of Industrial IoT encompasses the joint applicability of operation and information technologies to expand the efficiency expectation of automation to green and flexible processes with innovative products and services. Future industrial networks need to accommodate, manage and guarantee the performance of converged traffic from different technologies. The network infrastructures are transforming to enable data availability for advanced applications and enhance flexibility. Nonetheless, the pace of IT–OT networks development has been slow despite their considered benefits in optimising performance and enhancing information flows. The hindering factors vary from general challenges in performance management of the diverse traffic for greenfield configuration to the lack of outlines for evolving from brownfield installations without interrupting the operation of ongoing processes. One tangible gap is the lack of insight into the brownfield installation in operation. This dissertation explores the possible evolutionary steps from brownfield installations to future industrial networks.The goal is to ensure the uninterrupted performance of brownfield installations on the path of evolving to the envisioned smart factories. It addresses the gap between the state of the art and state of practice, and the technical prerequisites of the integrated traffic classes for the development of an IIoT monitoring mechanism. A novel lightweight learning algorithm at the sensor level for an IIoT compliance monitoring system, together with a case study of traffic collected from a brownfield installation, provides the baseline of comparative analysis between the common assumptions and the state of practice. The identified gaps and challenges to address them directs the research for proposing a two-step aggregated traffic modelling by introducing new measurement method and performance indicator parameters for capturing the communication dynamics. Lastly, the sensor-level learning algorithm is refined with the knowledge gained from practice and research contributions to propose an in-band telemetry mechanism for monitoring aggregated network traffic.
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| 50. |
- Muddala, Suryanarayana Murthy, 1984-
(author)
-
Free View Rendering for 3D Video : Edge-Aided Rendering and Depth-Based Image Inpainting
- 2015
-
Doctoral thesis (other academic/artistic)abstract
- Three Dimensional Video (3DV) has become increasingly popular with the success of 3D cinema. Moreover, emerging display technology offers an immersive experience to the viewer without the necessity of any visual aids such as 3D glasses. 3DV applications, Three Dimensional Television (3DTV) and Free Viewpoint Television (FTV) are auspicious technologies for living room environments by providing immersive experience and look around facilities. In order to provide such an experience, these technologies require a number of camera views captured from different viewpoints. However, the capture and transmission of the required number of views is not a feasible solution, and thus view rendering is employed as an efficient solution to produce the necessary number of views. Depth-image-based rendering (DIBR) is a commonly used rendering method. Although DIBR is a simple approach that can produce the desired number of views, inherent artifacts are major issues in the view rendering. Despite much effort to tackle the rendering artifacts over the years, rendered views still contain visible artifacts.This dissertation addresses three problems in order to improve 3DV quality: 1) How to improve the rendered view quality using a direct approach without dealing each artifact specifically. 2) How to handle disocclusions (a.k.a. holes) in the rendered views in a visually plausible manner using inpainting. 3) How to reduce spatial inconsistencies in the rendered view. The first problem is tackled by an edge-aided rendering method that uses a direct approach with one-dimensional interpolation, which is applicable when the virtual camera distance is small. The second problem is addressed by using a depth-based inpainting method in the virtual view, which reconstructs the missing texture with background data at the disocclusions. The third problem is undertaken by a rendering method that firstly inpaint occlusions as a layered depth image (LDI) in the original view, and then renders a spatially consistent virtual view.Objective assessments of proposed methods show improvements over the state-of-the-art rendering methods. Visual inspection shows slight improvements for intermediate views rendered from multiview videos-plus-depth, and the proposed methods outperforms other view rendering methods in the case of rendering from single view video-plus-depth. Results confirm that the proposed methods are capable of reducing rendering artifacts and producing spatially consistent virtual views.In conclusion, the view rendering methods proposed in this dissertation can support the production of high quality virtual views based on a limited number of input views. When used to create a multi-scopic presentation, the outcome of this dissertation can benefit 3DV technologies to improve the immersive experience.
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