Operation of distributed generation under stochastic prices

The ongoing deregulation of electricity industries worldwide is providing incentives for microgrids, entities that use small-scale distributed generation (DG) and combined heat and power (CHP) ap- plications to meet local energy loads, to evolve independently of the traditional centralised grid in order to provide greater flexibility and energy efficiency to end-use consumers. We examine the impact of start-up costs on the option values and operating schedules of on-site DG installed by a microgrid in the presence of stochastic electricity and fuel prices. We proceed by formulating a stochastic dynamic programme (SDP) for the microgrid that minimises its expected discounted cost over a time horizon and solving it using least-squares Monte Carlo (LSMC) simulation. The expected cost saving that the microgrid realises by having gas-fired DG installed relative to meeting its entire electric load via off-site purchases is the implied option value of DG. Numerical examples indicate that although start-up costs do not significantly lower DG value, they, nevertheless, have a profound impact on the optimal DG operating schedule as the microgrid must incorporate not only current, but also future, expected start-up costs into its current decision-making process as an opportunity cost. As a consequence, the microgrid becomes more hesitant to turn DG units on (off), preferring to wait until the electricity price (natural gas generating cost) exceeds the natural gas generating cost (electricity price) by a significant margin before taking action. We demonstrate that ignoring this tradeoff and proceeding myopically as in the case without start-up costs results in drastically higher expected costs and fewer opportunities to use DG

On-chip spectroscopy with thermally-tuned high-Q photonic crystal cavities

Spectroscopic methods are a sensitive way to determine the chemical composition of potentially hazardous materials. Here, we demonstrate that thermally-tuned high-Q photonic crystal cavities can be used as a compact high-resolution on-chip spectrometer. We have used such a chip-scale spectrometer to measure the absorption spectra of both acetylene and hydrogen cyanide in the 1550 nm spectral band, and show that we can discriminate between the two chemical species even though the two materials have spectral features in the same spectral region. Our results pave the way for the development of chip-size chemical sensors that can detect toxic substances

Asymptotic Behaviour of the Proper Length and Volume of the Schwarzschild Singularity

Though popular presentations give the Schwarzschild singularity as a point it is known that it is spacelike and not timelike. Thus it has a "length" and is not a "point". In fact, its length must necessarily be infinite. It has been proved that the proper length of the Qadir-Wheeler suture model goes to infinity [1], while its proper volume shrinks to zero, and the asymptotic behaviour of the length and volume have been calculated. That model consists of two Friedmann sections connected by a Schwarzschild "suture". The question arises whether a similar analysis could provide the asymptotic behaviour of the Schwarzschild black hole near the singularity. It is proved here that, unlike the behaviour for the suture model, for the Schwarzschild essential singularity $\Delta s$ $\thicksim$ $K^{1/3}\ln K$ and $V\thicksim$ $K^{-1}\ln K$, where $K$ is the mean extrinsic curvature, or the York time.Comment: 13 pages, 1 figur

William John Adie: the man behind the syndrome

William John Adie was an Australian neurologist in the early 20th century responsible for extensively describing the tonically dilated pupil associated with absent deep tendon reflexes – both features of a syndrome that now bears his name. In addition to other neurological syndromes, he was also significant in delineating narcolepsy through his clinical essays and case series. His ophthalmic and neurologic contributions have served the test of time and played an important role in the modern understanding of Adie syndrome and narcolepsy. This report reviews Adie's medical contributions, extensive descriptions of Adie syndrome, and provides a brief biographical account of his life

Labelling faces as “Autistic” reduces the Inversion Effect

This is the author accepted manuscript. The final version is available from SAGE Publications via the DOI in this recordDoes the belief that a face belongs to an individual with autism affect recognition of that face? To address this question, we used the inversion effect as a marker of face recognition. In Experiment 1, participants completed a recognition task involving upright and inverted faces labelled as either ‘regular’ or ‘autistic’. In reality, the faces presented in both conditions were identical. Results revealed a smaller inversion effect for faces labelled as autistic. Thus, simply labelling a face as ‘autistic’ disrupts recognition. Experiment 2 showed a larger inversion effect after the provision of humanizing versus dehumanizing information about faces labelled as ‘autistic’. We suggest changes in the inversion effect could be used as a measure to study stigma within the context of objectification and dehumanization.S.S.O. is supported by a discovery grant from the Natural Sciences and Engineering Research council of Canada. C.C. is supported by the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie (grant agreement No. 743702) and by the Economic and Social Research Council (ESRC) New Investigator Grant (Ref. ES/R005532)

Grasp Stability Prediction for a Dexterous Robotic Hand Combining Depth Vision and Haptic Bayesian Exploration.

Grasp stability prediction of unknown objects is crucial to enable autonomous robotic manipulation in an unstructured environment. Even if prior information about the object is available, real-time local exploration might be necessary to mitigate object modelling inaccuracies. This paper presents an approach to predict safe grasps of unknown objects using depth vision and a dexterous robot hand equipped with tactile feedback. Our approach does not assume any prior knowledge about the objects. First, an object pose estimation is obtained from RGB-D sensing; then, the object is explored haptically to maximise a given grasp metric. We compare two probabilistic methods (i.e. standard and unscented Bayesian Optimisation) against random exploration (i.e. uniform grid search). Our experimental results demonstrate that these probabilistic methods can provide confident predictions after a limited number of exploratory observations, and that unscented Bayesian Optimisation can find safer grasps, taking into account the uncertainty in robot sensing and grasp execution

A suspected virus infection of the oral mucosa in Swedish reindeer (Rangifer tarandus L)

During the winter 1980 reindeer herds in the Tornedalen area, along the Finnish border, were hit by grazing difficulties. Thus minor parts of the reindeer her*ds in this area were given supplementary feed in pens. Some of the supplementary fed animals were taken ill and some deaths occurred. According to the owners sick animals showed loss of appetite and signs of fever. A total of 8 carcasses were necropsied at The National Veterinary Institute. In 5 of these cases oral lesions were observed. The histological investigation of the oral mucosa revealed intracytoplasmic inclusion bodies, inter- and intracellular oedema and vesicle formation. An electron-microscopical study of 2 of the cases confirmed the histological findings. At the bacteriological investigations Coli, ß-haemolyzing streptococci, Conrynebacterium pyogenes and Fusobacterium necrophorum could be indentified. The found bacteria were all considered secondary invaders. Serological samples from four affected reindeer flocks were tested for antibodies against BVD-, P13 and IBR-virus as well as Chlamydia. A few samples showed low positive titres for agents tested but for BVDV. The result of the investigation indicates that a still unidentified virus could be the primary cause of this enzootically appearing disease of the oral mucosa in reindeer.Misstanke om virusinfektion i munnslemhinnan på svensk ren.Abstract in Swedish / Sammanfattning: Under vintern 1980 drabbades renhjordar i Tornedalsområdet av betessvårigheter. Av denna anledning fördes mindre flockar, ur hjordarna, till inhägnader och tillskottsutfodrades. En del av de tillskottsutfodrade djuren insjuknade och dödsfall inträffade. Enligt djurägarna förlorade de sjuka djuren aptiten och uppvisade tecken på feber. Av de döda renarna erhölls åtta fôr obduktion vid Statens Veterinärmedicinska anstalt. Hos fem av de obducerade renarna forelåg skador i munhålan. Vid histologisk undersokning av munslemhinnan påvisades intracytoplasmatiska inklusionskroppar, inter- och intracellulärt ödem och vesikelbildningar. Elektronmikroskopisk undersokning av två av fallen konfirmerade de histologiska undersökningarna. Vid de bakteriologiska undersökningarna påvisades våxt av kolibakterier, ß-hemolyserande streptokocker, Corynebacterium pyogenes och Fusobacterium necrophorum. I samtliga fall betraktades dessa som sekundårinfektio-ner. Serologiska undersökningar företogs, i fyra flockar dår dödsfall förekommit, avseende forekomst av antikroppar emot BVD-virus, Pi3 och IBR-virus samt Chlamydia. Ett mindre antal prover uppvisade positiva titrar fôr de undersökta agens utom vad avser BVD. Resultaten av undersökningarna indikerar att ett annu ej identifierat virus kan vara primärorsak till de enzootiskt upptrådande utbrotten av sjukliga förändringar i munhålen hos ren