633 research outputs found
Blockchain-based distributive auction for relay-assisted secure communications
Physical layer security (PLS) is considered as a promising technique to prevent information eavesdropping in wireless systems. In this context, cooperative relaying has emerged as a robust solution for achieving PLS due to multipath diversity and relatively lower transmission power. However, relays or the relay operators in the practical environment are unwilling for service provisioning unless they are incentivized for their cost of services. Thus, it is required to jointly consider network economics and relay cooperation to improve system efficiency. In this paper, we consider the problem of joint network economics and PLS using cooperative relaying and jamming. Based on the double auction theory, we model the interaction between transmitters seeking for a particular level of secure transmission of information and relay operators for suitable relay and jammer assignment, in a multiple source-destination networks. In addition, theoretical analyses are presented to justify that the proposed auction mechanism satisfies the desirable economic properties of individual rationality, budget balance, and truthfulness. As the participants in the traditional centralized auction framework may take selfish actions or collude with each other, we propose a decentralized and trustless auction framework based on blockchain technology. In particular, we exploit the smart contract feature of blockchain to construct a completely autonomous framework, where all the participants are financially enforced by smart contract terms. The security properties of the proposed framework are also discussed
Truth-Telling Mechanism for Two-Way Relay Selection for Secrecy Communications With Energy-Harvesting Revenue
This paper brings the novel idea of paying the utility to the winning agents in terms of some physical entity in cooperative communications. Our setting is a secret two-way communication channel where two transmitters exchange information in the presence of an eavesdropper. The relays are selected from a set of interested parties, such that the secrecy sum rate is maximized. In return, the selected relay nodes' energy harvesting requirements will be fulfilled up to a certain threshold through their own payoff so that they have the natural incentive to be selected and involved in the communication. However, relays may exaggerate their private information in order to improve their chance to be selected. Our objective is to develop a mechanism for relay selection that enforces them to reveal the truth since otherwise they may be penalized. We also propose a joint cooperative relay beamforming and transmit power optimization scheme based on an alternating optimization approach. Note that the problem is highly non-convex, since the objective function appears as a product of three correlated Rayleigh quotients. While a common practice in the existing literature is to optimize the relay beamforming vector for given transmit power via rank relaxation, we propose a second-order cone programming-based approach in this paper, which requires a significantly lower computational task. The performance of the incentive control mechanism and the optimization algorithm has bee
Incentivizing Signal and Energy Cooperation in Wireless Networks
Abstract-We consider a two-hop wireless network where the source(s) in the network have the ability to wirelessly power the relay(s) who also have their own data to send to the destination. Considering the fact that each node in the network aims to maximize its own metric, we adopt a game theoretic approach that foresees offering relaying of the sources' data in exchange for energy provided to the relays, and simultaneously offering energy to the relays in exchange for their relaying services. We first study a Stackelberg competition with the single relay node as the leader, and investigate the impact of having multiple source nodes in the system. We next study the reciprocal Stackelberg game with the single source as the leader, and investigate the inter-relay competition with multiple relays. We find that in the Stackelberg games, the leader can improve its individual utility by influencing the follower's decision accordingly, even more so when there are multiple followers. We next formulate a noncooperative game between the source and the relay and show the existence of a unique Nash equilibrium by an appropriate pricing mechanism. The equilibrium maximizes the total utility of the network and allows the destination to choose how much data to receive from each node
Viewpoint: Space Law and the Advancement of Spacepower
The opinions, conclusions, and recommendations expressed or implied in this paper are those of the author and do not necessarily reflect the official policy or position of the United States Air Force, Department of Defense, or United States Government. The author thanks David Koplow, Phil Meek, and Michael Saretsky for their extremely helpful comments on previous versions of this article.
Space law has and should continue to play an essential role in the evolution of spacepower. Testing the principle of “freedom of space” and helping establish the legality of satellite overflight were primary objectives of NSC- 5520, the first U.S. space policy, approved by President Eisenhower in May 1955; during the 1960s, the superpowers and other emerging spacefaring states negotiated a farreaching and forward-thinking Outer Space Treaty (OST); and today a variety of transparency- and confidence-building measures (TCBMs) for space are being discussed and debated in a number of fora
An Integrated Framework for Modelling and Control of eP2P Interactions based on Model Predictive Control
The energy paradigm is undergoing substantial changes in recent years. In terms of
production, it is observable how distributed generation, with an ever-increasing
contribution from renewable sources, is displacing large concentrated generation plants.
But the fundamental change is not so much about energy supply as about diluting the
historical roles of producers and consumers to give way to the concept of prosumers.
That is, instead of just being energy consumers, households and industries also become
producers. In principle, the purpose of this production, which is inherently distributed,
is self-consumption. However, when there is a surplus of production, prosumers can
choose between storing the excess, if they have an energy storage system, or sell the
unused fraction of energy.
An obvious type of prosumers are those industries that have renewable generation
facilities and which, as a consequence of their production process, generate by-products
that can be used for cogeneration. In this case an obvious problem for the company is
to select at all times the power sources that minimize the cost of production, which is
known as Optimal Power Dispatch (OPD). If, in addition, the energy consumption time
profile of the manufacturing process (per unit of raw material introduced) is known, it
is also possible to make an optimal production schedule to minimize energy cost, which
is called Optimal Power Scheduling (OPS). Chapter 3 presents an Economic Model
Predictive Controller (EMPC) that simultaneously performs OPD and OPS using an
olive mill as an example.
The emergence of the role of energy prosumers makes it necessary to extend, improve
or replace the traditional mechanisms of energy exchange. This thesis includes novel
approaches for modelling the behaviour of prosumers. It also proposes new structures to
facilitate energy trading, always from the perspective of the peerification of the energy
paradigm. Thus, another line of research studies the establishment of peer-to-peer
(P2P) markets for the exchange of energy between heterogeneous prosumers (homes,
vehicles, intelligent buildings, etc.). The efficiency of markets based on both discrete
double auctions (DDAs) and continuous double auctions (CDAs) is compared. An
Energy Management System (EMS) is also introduced including market agent software
that allows the necessary tasks for participation in the auctions to be carried out automatically (determination of private valuation, role selection and price adaptation).
Chapter 4, Chapter 5 and Chapter 6 present some examples of such exchange markets
stablished between different types of prosumers: i) energy market for electric vehicles
that coincide parked in a large workplace, ii) power market for households within the
same neighbourhood and iii) integrated energy and power markets for heterogeneous
energy entities.
The evolution of aforementioned mechanisms and the appearance of new market
models must be accompanied by the development of control techniques that optimise
and automate all the processes related to energy saving and trading, by a group of
increasingly heterogeneous prosumers. This thesis deals with how different variants of
predictive controllers can contribute to this last aspect. For industries with cogeneration
capacity, the EMPC contributes to the optimal scheduling of production to maximise
the return from energy reuse, either through self-consumption or through the trading of
surpluses. The use of stochastic predictive control is proposed in order to maximise the
expected return on the participation of prosumers, whatever their type, in continuous
markets where the price of energy may undergo stochastic variations.El paradigma energético está experimentando cambios sustanciales en los últimos
años. En cuanto a la producción, se observa cómo la generación distribuida,
con un aporte cada vez mayor de fuentes renovables, está desplazando a las grandes
plantas de generación concentrada. Pero el cambio fundamental no consiste tanto
en el suministro de energía como en la dilución de la clasificación tradicional entre
productores y consumidores para dar paso al concepto de prosumidores. Es decir,
en lugar de ser simplemente consumidores de energía, los hogares y las industrias
también se convierten en productores. En principio, el objetivo de esta producción,
que es intrínsecamente distribuida, es el autoconsumo. Sin embargo, cuando hay un
excedente de producción, los prosumidores pueden elegir entre almacenar el excedente,
si tienen un sistema de almacenamiento de energía, o vender la fracción no utilizada de
la energía.
Un tipo obvio de prosumidores son aquellas industrias que cuentan con instalaciones
de generación renovable y que, como consecuencia de su proceso de producción,
generan subproductos que pueden ser utilizados para la cogeneración. En este caso, un
problema obvio para la empresa es seleccionar en todo momento las fuentes de energía
que minimizan el coste de producción, lo que se conoce como Optimal Power Dispatch
(OPD). Si, además, se conoce el perfil temporal de consumo de energía asociado al
proceso de fabricación (por unidad de materia prima introducida), también es posible
realizar un programa de producción óptimo para minimizar el coste de la energía, lo cual
se denomina Optimal Power Scheduling (OPS). El capítulo 3 presenta un Controlador
Predictivo Económico basado en Modelo (EMPC) que realiza simultáneamente OPD y
OPS utilizando como caso de estudio una almazara olivarera.
La aparición de la figura de los prosumidores energéticos hace necesario ampliar,
mejorar o sustituir los mecanismos tradicionales de intercambio energético. Esta tesis
incluye enfoques novedosos para modelar el comportamiento de los prosumidores.
También propone nuevas estructuras para facilitar el comercio de energía, siempre
desde la perspectiva de la peerificación del paradigma energético. Así, otra línea
de investigación estudia el establecimiento de mercados peer-to-peer (P2P) para el
intercambio de energía entre prosumidores heterogéneos (viviendas, vehículos, edificios inteligentes, etc.). Se compara la eficiencia de los mercados basados tanto en subastas
dobles discretas (Discrete Double Auction - DDA) como en subastas dobles continuas
(Continuous Double Auctions - CDA). También se introduce un Sistema de Gestión
Energética (Energy Management System - EMS) que incluye un software de agente
de mercado que permite que las tareas necesarias para la participación en las subastas
(determinación de la valoración privada, selección de roles y adaptación de precios)
se lleven a cabo automáticamente. Los capítulos 4, 5 y 6 presentan algunos ejemplos
de estos mercados de intercambio establecidos entre diferentes tipos de prosumidores:
i) mercado de energía para vehículos eléctricos que coinciden aparcados en un gran
lugar de trabajo, ii) mercado de energía para hogares dentro de un mismo barrio y iii)
mercados integrados de energía y electricidad para entidades energéticas heterogéneas.
La evolución de los mecanismos mencionados y la aparición de nuevos modelos de
mercado deben ir acompañados del desarrollo de técnicas de control que optimicen y
automaticen todos los procesos relacionados con el ahorro y la comercialización de la
energía, por parte de un conjunto de prosumidores cada vez más heterogéneos. Esta
tesis trata de cómo las diferentes variantes de los controladores predictivos pueden
contribuir a este último aspecto. Para las industrias con capacidad de cogeneración,
el EMPC contribuye a la programación óptima de la producción para maximizar
el rendimiento de la reutilización de la energía, ya sea a través del autoconsumo o
de la comercialización de excedentes. Por otro lado, se propone el uso del control
predictivo estocástico para maximizar el rendimiento esperado de la participación de
los prosumidores, cualquiera que sea su tipo, en mercados P2P donde el precio de la
energía está sujeto a incertidumbres
Resource Management Techniques in Cloud-Fog for IoT and Mobile Crowdsensing Environments
The unpredictable and huge data generation nowadays by smart devices from IoT and mobile Crowd Sensing applications like (Sensors, smartphones, Wi-Fi routers) need processing power and storage. Cloud provides these capabilities to serve organizations and customers, but when using cloud appear some limitations, the most important of these limitations are Resource Allocation and Task Scheduling. The resource allocation process is a mechanism that ensures allocation virtual machine when there are multiple applications that require various resources such as CPU and I/O memory. Whereas scheduling is the process of determining the sequence in which these tasks come and depart the resources in order to maximize efficiency. In this paper we tried to highlight the most relevant difficulties that cloud computing is now facing. We presented a comprehensive review of resource allocation and scheduling techniques to overcome these limitations. Finally, the previous techniques and strategies for allocation and scheduling have been compared in a table with their drawbacks
Mean-Field-Type Games in Engineering
A mean-field-type game is a game in which the instantaneous payoffs and/or
the state dynamics functions involve not only the state and the action profile
but also the joint distributions of state-action pairs. This article presents
some engineering applications of mean-field-type games including road traffic
networks, multi-level building evacuation, millimeter wave wireless
communications, distributed power networks, virus spread over networks, virtual
machine resource management in cloud networks, synchronization of oscillators,
energy-efficient buildings, online meeting and mobile crowdsensing.Comment: 84 pages, 24 figures, 183 references. to appear in AIMS 201
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