Identifying residential consumption patterns using data-mining techniques: A large-scale study of smart meter data in Chengdu, China

The fine-grained electricity consumption data created by advanced metering technologies offers an opportunity to understand residential demand from new angles. Although there exists a large body of research on demand response in short- and long-term forecasting, a comprehensive analysis to identify household consumption behaviour in different scenarios has not been conducted. The study’s novelty lies in its use of unsupervised machine learning tools to explore residential customers’ demand patterns and response without the assistance of traditional survey tools. We investigate behavioural response in three different contexts: 1) seasonal (using weekly consumption profiles); 2) holidays/festivals; and 3) extreme weather situations. The analysis is based on the smart metering data of 2,000 households in Chengdu, China over three years from 2014 to 2016. Workday/weekend profiles indicate that there are two distinct groups of households that appear to be white-collar or relatively affluent families. Demand patterns at the major festivals in China, especially the Spring Festival, reveal various types of lifestyle and households. In terms of extreme weather response, the most striking finding was that in summer, at night-time, over 72% of households doubled (or more) their electricity usage, while consumption changes in winter do not seem to be significant. Our research offers more detailed insight into Chinese residential consumption and provides a practical framework to understand households’ behaviour patterns in different settings

Optical Tweezers as an Effective Tool for Spermatozoa Isolation from Mixed Forensic Samples

A single focus optical tweezer is formed when a laser beam is launched through a high numerical aperture immersion objective. This objective focuses the beam down to a diffraction-limited spot, which creates an optical trap where cells suspended in aqueous solutions can be held fixed. Spermatozoa, an often probative cell type in forensic investigations, can be captured inside this optical trap and dragged one by one across millimeter-length distances in order to create a cluster of cells which can be subsequently drawn up into a capillary for collection. Sperm cells are then ejected onto a sterile cover slip, counted, and transferred to a tube for DNA analysis workflow. The objective of this research was to optimize sperm cell collection for maximum DNA yield, and to determine the number of trapped sperm cells necessary to produce a full STR profile. A varying number of sperm cells from both a single-source semen sample and a mock sexual assault sample were isolated utilizing optical tweezers and processed using conventional STR analysis methods. Results demonstrated that approximately 50 trapped spermatozoa were required to obtain a consistently full DNA profile. A complete, single-source DNA profile was also achieved by isolating sperm cells via optical trapping from a mixture of sperm and vaginal epithelial cells. Based on these results, optical tweezers are a viable option for forensic applications such as separation of mixed populations of cells in forensic evidence

Reflection factorizations of Singer cycles

Abstract. The number of shortest factorizations into reflections for a Singer cycle inGLn(Fq) is shown to be (q n − 1) n−1. Formulas counting factorizations of any length, and counting those with reflections of fixed conjugacy classes are also given. Résumé. Nous prouvons que le nombre de factorisations de longueur minimale d’un cycle de Singer dans GLn(Fq) comme un produit de réflexions est (q n −1) n−1. Nous présentons aussi des formules donnant le nombre de factorisations de toutes les longueurs ainsi que des formules pour le nombre de factorisations comme produit de réflexions ayant des classes de conjugaison fixes

High transport currents in mechanically reinforced MgB2 wires

We prepared and characterized monofilamentary MgB2 wires with a mechanically reinforced composite sheath of Ta(Nb)/Cu/steel, which leads to dense filaments and correspondingly high transport currents up to Jc = 10^5 A/cm^2 at 4.2 K, self field. The reproducibility of the measured transport currents was excellent and not depending on the wire diameter. Using different precursors, commercial reacted powder or an unreacted Mg/B powder mixture, a strong influence on the pinning behaviour and the irreversibility field was observed. The critical transport current density showed a nearly linear temperature dependency for all wires being still 52 kA/cm^2 at 20 K and 23 kA/cm^2 at 30 K. Detailed data for Jc(B,T) and Tc(B) were measured.Comment: 21 pages, 13 figures, revised version, to be published in Supercond. Sci. Techno

Trust in Government and Effective Nuclear Safety Governance in Great Britain

Nuclear power can play a role in reducing CO2 emissions and improving energy security. Public attitudes to nuclear safety governance will be critical in whether a large-scale rollout of nuclear power will be successful, so we commissioned a survey of 1,007 members of the British public to understand the determinants of such views. In particular, we focus on the role of trust in government, which has been largely neglected as a subject of study. We find that higher risk perceptions of new nuclear power technologies is associated with lower overall government trustworthiness, while higher engagement levels, being male and intentions to vote Conservative increase trustworthiness. Risk perceptions towards old and the new nuclear technologies do not differ significantly, which raises questions about the view that newer defence-in-depth nuclear technologies can reduce public fear of nuclear power. To build public trust, the UK government must demonstrate its trustworthiness in nuclear safety governance, especially along the dimensions of integrity, reliability and openness. Further, improving stakeholder engagement and thus increasing the levels of public satisfaction towards the government are necessary. Our novel research methodology of determining government trustworthiness in relation to public risk perceptions, technical knowledge, and stakeholder engagement is more broadly applicable and can be transferred to other subject areas and to countries where public concerns over nuclear safety and energy security are significant

Relativistic Proton Production During the 14 July 2000 Solar Event: The Case for Multiple Source Mechanisms

Protons accelerated to relativistic energies by transient solar and interplanetary phenomena caused a ground-level cosmic ray enhancement on 14 July 2000, Bastille Day. Near-Earth spacecraft measured the proton flux directly and ground-based observatories measured the secondary responses to higher energy protons. We have modelled the arrival of these relativistic protons at Earth using a technique which deduces the spectrum, arrival direction and anisotropy of the high-energy protons that produce increased responses in neutron monitors. To investigate the acceleration processes involved we have employed theoretical shock and stochastic acceleration spectral forms in our fits to spacecraft and neutron monitor data. During the rising phase of the event (10:45 UT and 10:50 UT) we find that the spectrum between 140 MeV and 4 GeV is best fitted by a shock acceleration spectrum. In contrast, the spectrum at the peak (10:55 UT and 11:00 UT) and in the declining phase (11:40 UT) is best fitted with a stochastic acceleration spectrum. We propose that at least two acceleration processes were responsible for the production of relativistic protons during the Bastille Day solar event: (1) protons were accelerated to relativistic energies by a shock, presumably a coronal mass ejection (CME). (2) protons were also accelerated to relativistic energies by stochastic processes initiated by magnetohydrodynamic (MHD) turbulence.Comment: 38 pages, 9 figures, accepted for publication in the Astrophysical Journal, January, 200

Social science sequestered

Greenhouse gas removal (GGR) raises many cultural, ethical, legal, social, and political issues, yet in the growing area of GGR research, humanities and social sciences (HASS) research is often marginalized, constrained and depoliticised. This global dynamic is illustrated by an analysis of the UK GGR research programme. This dynamic matters for the knowledge produced and for its users. Without HASS contributions, too narrow a range of perspectives, futures and issues will be considered, undermining or overpromising the prospects for the responsible development of GGR (and threatening worse side-effects), and limiting our understanding of why and how policy demands GGR solutions in the first place. In response, we present policy principles for bringing HASS fully into GGR research, organized around three themes: (1) HASS-led GGR research, (2) Opening up GGR futures, and (3) The politics of GGR futures.We acknowledge funding from the UK GGR programme, under several specific grants: NE/P019838/1, NE/P019900/1, NE/P019951/1, NE/P019668/1, and NE/P01982X/1