Cost-effective and Resilient Operation of Distribution Grids and 5G Telecommunication

5G base stations have growing importance in an integrated electric power and telecommunication system, for mobile user equipment mobile data supply and demand response in distribution grids. However, demand response through base station’s flexibility can have a growing impact on the power flow of the grid. Additionally, in extreme events, if a power outage occurs at the physical base station, data loads need to be first reconnected to the 5G network, which is essential for the grid to further recover the electricity loads. In this paper, a cost-effective and resilient operation method is proposed to optimally utilize the flexibility of renewable-based 5G base stations and the data load shedding to recover the data transmission. The flexibility from batteries equipped in the base stations and the flexible associations between user equipments and base stations are considered. The simulation results verify the proposed method can achieve lower energy costs and power losses of the grid in normal operation and a resilient operation in an extreme event

Are the Tails of Percolation Thresholds Gaussians ?

The probability distribution of percolation thresholds in finite lattices were first believed to follow a normal Gaussian behaviour. With increasing computer power and more efficient simulational techniques, this belief turned to a stretched exponential behaviour, instead. Here, based on a further improvement of Monte Carlo data, we show evidences that this question is not yet answered at all.Comment: 7 pages including 3 figure

Efficient Monte Carlo algorithm and high-precision results for percolation

We present a new Monte Carlo algorithm for studying site or bond percolation on any lattice. The algorithm allows us to calculate quantities such as the cluster size distribution or spanning probability over the entire range of site or bond occupation probabilities from zero to one in a single run which takes an amount of time scaling linearly with the number of sites on the lattice. We use our algorithm to determine that the percolation transition occurs at occupation probability 0.59274621(13) for site percolation on the square lattice and to provide clear numerical confirmation of the conjectured 4/3-power stretched-exponential tails in the spanning probability functions.Comment: 8 pages, including 3 postscript figures, minor corrections in this version, plus updated figures for the position of the percolation transitio

Universality of finite-size corrections to the number of critical percolation clusters

Monte-Carlo simulations on a variety of 2d percolating systems at criticality suggest that the excess number of clusters in finite systems over the bulk value of nc is a universal quantity, dependent upon the system shape but independent of the lattice and percolation type. Values of nc are found to high accuracy, and for bond percolation confirm the theoretical predictions of Temperley and Lieb, and Baxter, Temperley, and Ashley, which we have evaluated explicitly in terms of simple algebraic numbers. Predictions for the fluctuations are also verified for the first time.Comment: 13 pages, 2 figs., Latex, submitted to Phys. Rev. Let

Transistors

Contains reports on six research projects

A fast Monte Carlo algorithm for site or bond percolation

We describe in detail a new and highly efficient algorithm for studying site or bond percolation on any lattice. The algorithm can measure an observable quantity in a percolation system for all values of the site or bond occupation probability from zero to one in an amount of time which scales linearly with the size of the system. We demonstrate our algorithm by using it to investigate a number of issues in percolation theory, including the position of the percolation transition for site percolation on the square lattice, the stretched exponential behavior of spanning probabilities away from the critical point, and the size of the giant component for site percolation on random graphs.Comment: 17 pages, 13 figures. Corrections and some additional material in this version. Accompanying material can be found on the web at http://www.santafe.edu/~mark/percolation

A reduced-reference perceptual image and video quality metric based on edge preservation

In image and video compression and transmission, it is important to rely on an objective image/video quality metric which accurately represents the subjective quality of processed images and video sequences. In some scenarios, it is also important to evaluate the quality of the received video sequence with minimal reference to the transmitted one. For instance, for quality improvement of video transmission through closed-loop optimisation, the video quality measure can be evaluated at the receiver and provided as feedback information to the system controller. The original image/video sequence-prior to compression and transmission-is not usually available at the receiver side, and it is important to rely at the receiver side on an objective video quality metric that does not need reference or needs minimal reference to the original video sequence. The observation that the human eye is very sensitive to edge and contour information of an image underpins the proposal of our reduced reference (RR) quality metric, which compares edge information between the distorted and the original image. Results highlight that the metric correlates well with subjective observations, also in comparison with commonly used full-reference metrics and with a state-of-the-art RR metric. © 2012 Martini et al

The electrophotonic silicon biosensor

The emergence of personalized and stratified medicine requires label-free and low-cost diagnostic technology capable of monitoring multiple disease biomarkers in parallel. Silicon photonic biosensors combine high sensitivity analysis with scalable, low-cost manufacturing technology but they tend to measure only a single biomarker and provide no information about their (bio)chemical activity. Here, we introduce an electrochemical silicon photonic sensor capable of highly sensitive and multiparameter profiling of biomolecules. Our electro-photonic technology consists of microring resonators optimally n-doped to support high Q resonances alongside electrochemical processes in situ. The inclusion of electrochemical processes enables site selective immobilization of different biomolecules, here single stranded DNA, onto individual microrings within a sensor array. The combination of photonic and electrochemical characterization of molecules bound to the sensor surface also provides direct quantification of binding density and unique insight into chemical reactivity that is unavailable with photonic detection alone. By exploiting both the photonic and the electrical properties of silicon, the sensor opens new modalities for sensing on the micro-scale

Two images of Nantes as a ‘Green Model’ of Urban Planning and Governance: The ‘Collaborative City’ Versus the ‘Slow City’

This article examines how the city of Nantes, European Green Capital in 2013, came to promote plans for a new international airport at Notre-Dame-des-Landes. Deploying poststructuralist discourse theory, it analyses how the highly politicised struggle against the airport reveals the limits of the Nantes model of urban sustainability and collaboration, giving rise to a counter model, which we provisionally characterise as the ‘slow city’. While the struggle against the airport can be understood as a rural social movement, we show how its ideals and logics have been progressively displaced to Nantes itself, disclosing new images and possibilities of urban governance