A survey on cyber security for smart grid communications

A smart grid is a new form of electricity network with high fidelity power-flow control, self-healing, and energy reliability and energy security using digital communications and control technology. To upgrade an existing power grid into a smart grid, it requires significant dependence on intelligent and secure communication infrastructures. It requires security frameworks for distributed communications, pervasive computing and sensing technologies in smart grid. However, as many of the communication technologies currently recommended to use by a smart grid is vulnerable in cyber security, it could lead to unreliable system operations, causing unnecessary expenditure, even consequential disaster to both utilities and consumers. In this paper, we summarize the cyber security requirements and the possible vulnerabilities in smart grid communications and survey the current solutions on cyber security for smart grid communications. © 2012 IEEE

How much does transmit correlation affect the sum-rate scaling of MIMO Gaussian broadcast channels?

This paper considers the effect of spatial correlation between transmit antennas on the sum-rate capacity of the MIMO Gaussian broadcast channel (i.e., downlink of a cellular system). Specifically, for a system with a large number of users n, we analyze the scaling laws of the sum-rate for the dirty paper coding and for different types of beamforming transmission schemes. When the channel is i.i.d., it has been shown that for large n, the sum rate is equal to M log log n + M log P/M + o(1) where M is the number of transmit antennas, P is the average signal to noise ratio, and o(1) refers to terms that go to zero as n → ∞. When the channel exhibits some spatial correlation with a covariance matrix R (non-singular with tr(R) = M), we prove that the sum rate of dirty paper coding is M log log n + M log P/M + log det(R) + o(1). We further show that the sum-rate of various beamforming schemes achieves M log log n + M log P/M + M log c + o(1) where c ≤ 1 depends on the type of beamforming. We can in fact compute c for random beamforming proposed in and more generally, for random beamforming with preceding in which beams are pre-multiplied by a fixed matrix. Simulation results are presented at the end of the paper

Stitching, Healing and Empowering: Interrogating the Garden as a Space of Reclamation, Occupied Palestine

This folio sets out recent projects by Sharif and Golzari for the Palestine Regeneration Team (PART) which explores how architecture can ‘stitch, heal and empower’ communities in Occupied Palestine, combining built and speculative design. Founded with Murray Fraser in 2008, PART’s recent work explores how garden, landscape and green space can be used in reinforcing their identity and relationship to the land. Sharif and Golzari’s approach brings forward ‘absent’ narratives through spatial means. Using techniques of ‘social mapping’ and analysis of everyday life and traditional cultural practices, the projects promote low-cost, sustainable responses, forming part of an ongoing group of interlinked projects which offer architectural interventions to heal rural communities in Palestine. Projects can be seen as models, working and tested prototypes for other villages across the West Bank and Gaza. PART works with local NGOs, UN-Habitat and municipalities through the repair of landscapes and the regeneration of historic village centres across the West Bank and in the reconstruction of destroyed neighbourhoods in Gaza. This folio features case studies reflecting how PART’s pragmatic built interventions are complemented by more speculative and experimental design work. The former is represented here by the Beit Iksa project near Jerusalem, a part-ruined village regenerated through design participation into a stable and productive landscape where vegetable gardens and eco-playgrounds become spaces of reclamation. The more speculative work includes the Digital Garden project, part of both broader international dissemination of the built work and a method to develop and promote a positive, Palestinian-based creative response to a threatened identity that explores the potential for stealth interventions within the fissures created by Israeli occupation. PART’s work was shortlisted for the RIBA research awards 2016, and The Digital Garden was exhibited at the 2019 AWAN Festival UK, the Chicago Architecture Biennial and the 2020 Berlinale

Phantom Accretion by Five Dimensional Charged Black Hole

This paper deals with the dynamical behavior of phantom field near five dimensional charged black hole. We formulate equations of motion for steady-state spherically symmetric flow of phantom fluids. It is found that phantom energy accretes onto black holes for $u<0$. Further, the location of critical point of accretion are evaluated that leads to mass to charge ratio for 5D charged black hole. This ratio implies that accretion cannot transform a black hole into a naked singularity. We would like to mention here that this work is an irreducible extension of 4D charged black hole.Comment: 8 pages, accepted for publication in Mod. Phys. Lett.

Charged Cylindrical Collapse of Anisotropic Fluid

Following the scheme developed by Misner and Sharp, we discuss the dynamics of gravitational collapse. For this purpose, an interior cylindrically symmetric spacetime is matched to an exterior charged static cylindrically symmetric spacetime using the Darmois matching conditions. Dynamical equations are obtained with matter dissipating in the form of shear viscosity. The effect of charge and dissipative quantities over the cylindrical collapse are studied. Finally, we show that homogeneity in energy density and conformal flatness of spacetime are necessary and sufficient for each other.Comment: 19 pages, accepted for publication in Gen. Relativ. Gra

A survey on smart grid communication infrastructures: Motivations, requirements and challenges

A communication infrastructure is an essential part to the success of the emerging smart grid. A scalable and pervasive communication infrastructure is crucial in both construction and operation of a smart grid. In this paper, we present the background and motivation of communication infrastructures in smart grid systems. We also summarize major requirements that smart grid communications must meet. From the experience of several industrial trials on smart grid with communication infrastructures, we expect that the traditional carbon fuel based power plants can cooperate with emerging distributed renewable energy such as wind, solar, etc, to reduce the carbon fuel consumption and consequent green house gas such as carbon dioxide emission. The consumers can minimize their expense on energy by adjusting their intelligent home appliance operations to avoid the peak hours and utilize the renewable energy instead. We further explore the challenges for a communication infrastructure as the part of a complex smart grid system. Since a smart grid system might have over millions of consumers and devices, the demand of its reliability and security is extremely critical. Through a communication infrastructure, a smart grid can improve power reliability and quality to eliminate electricity blackout. Security is a challenging issue since the on-going smart grid systems facing increasing vulnerabilities as more and more automation, remote monitoring/controlling and supervision entities are interconnected. © 1998-2012 IEEE

Accuracy of distributed strain sensing with single mode fibre in composite laminates under thermal and vibration loads

In this work, the strain measurement accuracy of single-mode fibre (SMF) under thermal and vibration loads is investigated by strain-frequency shift coefficient analyses. This research allows for the application of SMF sensors for structural health monitoring in real operational conditions. The strain measurement accuracy under combined static and thermal load is investigated experimentally, which demonstrated that temperature fluctuations induce non-negligible errors in the strain measurement, even with temperature compensation applied. The temperature fluctuation range which can induce measurement errors is quantified as less than −20°C or higher than 55°C. In addition, a fatigue experiment is conducted to investigate the measurement accuracy under low-frequency vibration load. The results of the fatigue experiment demonstrate that the vibrations mainly increase the ratio of null values in strain measurements. Findings from experiments can be applied to enhance structural health monitoring accuracy and reduce false positives. This study has important implications for the service application of distributed optical fibre sensing for composite structure health monitoring

Latest Advances in Waste Plastic Pyrolytic Catalysis

With the increase in demand for plastic use, waste plastic (WP) management remains a challenge in the contemporary world due to the lack of sustainable efforts to tackle it. The increment in WPs is proportional to man’s demand and use of plastics, and these come along with environmental challenges. This increase in WPs, and the resulting environmental consequences are mainly due to the characteristic biodegradation properties of plastics. Landfilling, pollution, groundwater contamination, incineration, and blockage of drainages are common environmental challenges associated with WPs. The bulk of these WPs constitutes polyethene (PE), polyethene terephthalate (PET) and polystyrene (PS). Pyrolysis is an eco-friendly thermo-chemical waste plastic treatment solution for valuable product recovery, preferred over landfilling and incineration solutions. In this extensive review, a critical investigation on waste plastic catalytic pyrolysis (WPCP) is performed, including catalyst and non-catalyst applications to sustainably tackle WP management. Current catalysis techniques are revealed, and some comparisons are made where necessary. Common pyrolytic products and common shortcomings and errors related to WP catalysis were also identified. The benefits of catalysts and their applications to augment and optimise thermal pyrolysis are emphasised. With all these findings, and more, this paper provides reassurance on the significance of catalysis to industrial-scale applications and products and supports related WPCP research work concerning the environment and other beneficiaries

Recent Advances on Waste Plastic Thermal Pyrolysis: A Critical Overview

Post-consumer plastic management, otherwise termed waste plastic (WP) management, is a great challenge in today’s world, mainly because of its characteristic biodegradation properties. The quantity of waste plastics correspondingly increases with the increase in demand for plastic use. Research has shown that this demand increases yearly. Most of these waste plastics include high-density polyethylene (HDPE), low-density polyethylene (LDPE), polyethylene terephthalate (PET) and polystyrene (PS). Potentially, these wastes are a wealth, and studies have explored that pyrolysis is a reputable mechanism to accomplish this. In this critical review, an extensive investigation on waste plastics thermal pyrolysis (WPTP) is carried out. The factors that affect the product’s yield and selectivity are discussed, and a comparative quality guarantee of WPTP is examined. This paper presents an assurance into the current findings of WPTP and reveals some common gaps and misconceptions surrounding this field, which are recommendable towards the support of further research work. The significant role of co-pyrolysis of plastics with biomass in this field is also emphasised, and a glimpse into the influence of mixed waste plastics in pyrolysis is presented