56 research outputs found
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The approximate Determinantal Assignment Problem
The Determinantal Assignment Problem (DAP) has been introduced as the unifying description of all frequency assignment problems in linear systems and it is studied in a projective space setting. This is a multi-linear nature problem and its solution is equivalent to finding real intersections between a linear space, associated with the polynomials to be assigned, and the Grassmann variety of the projective space. This paper introduces a new relaxed version of the problem where the computation of the approximate solution, referred to as the approximate DAP, is reduced to a distance problem between a point in the projective space from the Grassmann variety Gm(Rn). The cases G2(Rn) and its Hodge-dual Gnā2(Rn) are examined and a closed form solution to the distance problem is given based on the skew-symmetric matrix description of multivectors via the gap metric. A new algorithm for the calculation of the approximate solution is given and stability radius results are used to investigate the acceptability of the resulting perturbed solutions
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Towards a Security, Privacy, Dependability, Interoperability Framework for the Internet of Things
A popular application of ambient intelligence systems constitutes of assisting living services on smart buildings. As intelligence is imported in embedded equipment, the system becomes able to provide smart services (e.g. control lights, airconditioning, provide energy management services etc.). IoT is the main enabler of such environments. However, the interconnection of these cyber-physical systems and the processing of personal data raise serious security and privacy issues. In this paper we present a framework that can guarantee Security, Privacy, Dependability and Interoperability (SPDI) in IoT. Taking advantage of the underlying IoT deployment, the proposed framework not only implements the requested smart functionality but also provide modelling and administration that can guarantee those SPDI properties. Moreover, we provide an application example of the framework in a smart building scenario
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The approximate determinantal assignment problem
The Determinantal Assignment Problem (DAP) is one of the central problems of Algebraic Control Theory and refers to solving a system of non-linear algebraic equations to place the critical frequencies of the system to specied locations. This problem is decomposed into a linear and a multi-linear subproblem and the solvability of the problem is reduced to an intersection of a linear variety with the Grassmann variety. The linear subproblem can be solved with standard methods of linear algebra, whereas the intersection problem is a problem within the area of algebraic geometry. One of the methods to deal with this problem is to solve the linear problem and then and which element of this linear space is closer - in terms of a metric - to the Grassmann variety. If the distance is zero then a solution for the intersection problem is found, otherwise we get an approximate solution for the problem, which is referred to as the approximate DAP. In this thesis we examine the second case by introducing a number of new tools for the calculation of the minimum distance of a given parametrized multi-vector that describes the linear variety implied by the linear subproblem, from the Grassmann variety as well as the decomposable vector that realizes this least distance, using constrained optimization techniques and other alternative methods, such as the SVD properties of the so called Grassmann matrix, polar decompositions and mother tools. Furthermore, we give a number of new conditions for the appropriate nature of the approximate polynomials which are implied by the approximate solutions based on stability radius results. The approximate DAP problem is completely solved in the 2-dimensional case by examining uniqueness and non-uniqueness (degeneracy) issues of the decompositions, expansions to constrained minimization over more general varieties than the original ones (Generalized Grassmann varieties), derivation of new inequalities that provide closed-form non-algorithmic results and new stability radii criteria that test if the polynomial implied by the approximate solution lies within the stability domain of the initial polynomial. All results are compared with the ones that already exist in the respective literature, as well as with the results obtained by Algebraic Geometry Toolboxes, e.g., Macaulay 2. For numerical implementations, we examine under which conditions certain manifold constrained algorithms, such as Newton's method for optimization on manifolds, could be adopted to DAP and we present a new algorithm which is ideal for DAP approximations. For higher dimensions, the approximate solution is obtained via a new algorithm that decomposes the parametric tensor which is derived by the system of linear equations we mentioned before
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Fault Tolerance Using an SDN Pattern Framework
Software Defined Networking (SDN) and Network Function Virtualization (NFV) are a promising combination for programmable connectivity, rapid service provisioning and service chaining as they offer the necessary end-to-end optimizations. However, with the actual exponential growth of connected devices, future networks such as SDN/NFV require an open-solutions architecture, facilitated by standards and a strong ecosystem. Such networks need to support communication services that offers guarantees about fault tolerance, redundancy, resilience and security. The construction of complex networks preserving Security and Dependability (S&D) properties is necessary to avoid system vulnerabilities, which may occur in the various layers of SDN architectures. In this work, we propose a pattern framework build in an SDN controller able to import design patterns in a rule-based language in order to provide fault tolerance in SDN networks. To evaluate the importance and the functionality of this framework, fault tolerance patterns are proposed to guarantee network connectivity, detection and restoration of network traffic in SDN network infrastructures
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A pattern-based approach for designing reliable cyber-physical systems
Cyber-Physical Systems (CPS) appear to be of paramount importance due to their increasing use on critical infrastructure. New challenges have occurred because of the nature and the complexity of such systems in supporting heterogeneous physical and cyber components simultaneously. Failures or attacks on system components decrease system reliability creating severe consequences to CPS and the attached applications. The construction of complex CPS with respect to security and dependability (SandD) properties is necessary to avoid system vulnerabilities at design level. Design patterns are solutions for reusable designs and interactions of objects. In this work we present a pattern-based language for designing CPS able to guarantee SandD properties. The first set of SandD patterns includes the Reliability Component Composition (RCC) Patterns for designing reliable CPS. RCC patterns are encoded in Drools, which is a rule-based reasoning system. To evaluate our approach, we use RCC patterns as a methodology for designing a reliable wireless sensor network attached to a physical architecture to send monitored data to a central controller through relay nodes and paths
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Cyber insurance of information systems: Security and privacy cyber insurance contracts for ICT and helathcare organizations
Nowadays, more-and-more aspects of our daily activities are digitalized. Data and assets in the cyber-space, both for individuals and organizations, must be safeguarded. Thus, the insurance sector must face the challenge of digital transformation in the 5G era with the right set of tools. In this paper, we present CyberSure-an insurance framework for information systems. CyberSure investigates the interplay between certification, risk management, and insurance of cyber processes. It promotes continuous monitoring as the new building block for cyber insurance in order to overcome the current obstacles of identifying in real-time contractual violations by the insured party and receiving early warning notifications prior the violation. Lightweight monitoring modules capture the status of the operating components and send data to the CyberSure backend system which performs the core decision making. Therefore, an insured system is certified dynamically, with the risk and insurance perspectives being evaluated at runtime as the system operation evolves. As new data become available, the risk management and the insurance policies are adjusted and fine-tuned. When an incident occurs, the insurance company possesses adequate information to assess the situation fast, estimate accurately the level of a potential loss, and decrease the required period for compensating the insured customer. The framework is applied in the ICT and healthcare domains, assessing the system of medium-size organizations. GDPR implications are also considered with the overall setting being effective and scalable
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Threat Landscape and Good Practice Guide for Software Defined Networks/5G
5G represents the next major phase of mobile telecommunication systems and network architectures beyond the current 4G standards, aiming at extreme broadband and ultra-robust, low latency connectivity, to enable the programmable connectivity for the Internet of Everything2. Despite the significant debate on the technical specifications and the technological maturity of 5G, which are under discussion in various fora3, 5G is expected to affect positively and significantly several industry sectors ranging from ICT to industry sectors such as car and other manufacturing, health and agriculture in the period up to and beyond 2020. 5G will be driven by the influence of software on network functions, known as Software Defined Networking (SDN) and Network Function Virtualization (NFV). The key concept that underpins SDN is the logical centralization of network control functions by decoupling the control and packet forwarding functionality of the network. NFV complements this vision through the virtualization of these functionalities based on recent advances in general server and enterprise IT virtualization. Considering the technological maturity of the technologies that 5G can leverage on, SDN is the one that is moving faster from development to production. To realize the business potential of SDN/5G, a number of technical issues related to the design and operation of Software Defined Networks need to be addressed. Amongst them, SDN/5G security is one of the key issues, that needs to be addressed comprehensively in order to avoid missing the business opportunities arising from SDN/5G. In this report, we review threats and potential compromises related to the security of SDN/5G networks. More specifically, this report contains a review of the emerging threat landscape of 5G networks with particular focus on Software Defined Networking. It also considers security of NFV and radio network access. To provide a comprehensive account of the emerging threat SDN/5G landscape, this report has identified related network assets and the security threats, challenges and risks arising for these assets. Driven by the identified threats and risks, this report has also reviewed and identified existing security mechanisms and good practices for SDN/5G/NFV, and based on these it has analysed gaps and provided technical, policy and organizational recommendations for proactively enhancing the security of SDN/5G
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A lightweight framework for secure life-logging in smart environments
As the world becomes an interconnected network where objects and humans interact with each other, new challenges and threats appear in the ecosystem. In this interconnected world, smart objects have an important role in giving users the chance for life-logging in smart environments. However, smart devices have several limitations with regards to memory, resources and computation power, hindering the opportunity to apply well-established security algorithms and techniques for secure life-logging on the Internet of Things (IoT) domain. The need for secure and trustworthy life-logging in smart environments is vital, thus, a lightweight approach has to be considered to overcome the constraints of smart objects. The purpose of this paper is to present in details the current topics of life-logging in smart environments, while describing interconnection issues, security threats and suggesting a lightweight framework for ensuring security, privacy and trustworthy life-logging. In order to investigate the efficiency of the lightweight framework and the impact of the security attacks on energy consumption, an experimental test-bed was developed including two interconnected users and one smart attacker, who attempts to intercept transmitted messages or interfere with the communication link. Several mitigation factors, such as power control, channel assignment and AES-128 encryption were pplied for secure life-logging. Finally, research into the degradation of the consumed energy regarding the described intrusions is presented
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Pairing a Circular Economy and the 5G-Enabled Internet of Things: Creating a Class of āLooping Smart Assetsā
The increase in the worldās population has led to a
massive rise in human consumption of the planetās natural
resources, well beyond their replacement rate. Traditional
recycling concepts and methods are not enough to counter such
effects. In this context, a circular economy (CE), that is, a
restorative and regenerative by-design economy, can reform
todayās ātakeāmakeādisposeā economic model. On the other hand,
the Internet of Things (IoT) continues to gradually transform our
everyday lives, allowing for the introduction of novel types of
services while enhancing legacy ones. Taking this as our
motivation, in this article we analyze the CE/IoT interplay,
indicating innovative ways in which this interaction can drastically
affect products and services, their underlying business models,
and the associated ecosystems. Moreover, we present an IoT
architecture that enables smart object integration into the IoT
ecosystem. The presented architecture integrates circularityenabling
features by maximizing the exploitation of assets toward
a new type of IoT ecosystem that is circular by design (CbD).
Finally, we provide a proof-of-concept implementation and an
application study of the proposed architecture and results
regarding the applicability of the proposed approach for the
telecommunications (telecom) sector
Communications in Emergency and Crisis Situations
Abstract. In emergency and crisis situations (ECS) like earthquakes, tsunamis, terrorist attacks, it is very important that communication facilities are operative to provide services both to rescue teams and civilians. In ECS it is very common that communication premises are often unable to provide services, either due to physical damages or traffic overload. In such a case there is the need for rapid reestablishment of communication services. In this paper the communication services that can be exploited for ECS mitigation are discussed. The usage scenarios of such services are studied. Following that and looking from a network perspective view an ECS communication network architecture is presented. This architecture aims to provide seamless interoperability of varies communication technologies often present in EC
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