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The use of the LastQuake information system, its app, the associated Twitter account, and, to a lesser extent, the EMSC’s websites have been analyzed for the 7 days following the November 26, 2019, M6.4 Albania destructive earthquake to evaluate what can be improved and how crowdsourcing of information and monitoring of both use and absence of use of the app can contribute to rapid situational awareness. The mainshock and its numerous felt aftershocks triggered a strong public desire for information, which in turn led to rapid and massive adoption of the LastQuake app by up to 5% of the country’s population. The constant flow of new app users created a stress test of the app’s crowdsourcing features and led to errors in the association of felt reports with their appropriate earthquake. However, these errors had no identifiable impact, supporting the conclusion that the curation mechanisms currently in place are efficient. The rapid succession of felt aftershocks contributed to these errors by making information related to the mainshock difficult to access within hours of its occurrence, especially for new users who were not attuned to the app, since more recent events pushed older ones down the timeline of presented information. This revealed that prioritization of information within the app layout was lacking and must be an important design objective, especially during aftershock sequences. LastQuake has been shown to be a powerful tool for rapid situational awareness. The possibility of damage was detected within 8 min of the mainshock earthquake by a lack of LastQuake app activity close to the epicenter. This possibility was then gradually strengthened as new data became available and was finally confirmed by the reception of the first geo-located pictures of structural damage and building collapse within 60–70 min. Direct exchanges on Twitter were appreciated by eyewitnesses and seemed to help to reduce their anxiety in some cases (based on the personal reports). Questions mainly focused on the possible evolution of the seismicity. Attempts to debunk prediction claims were difficult. We report on how this could be eased and possibly made more efficient by sharing among the different actors a clear, concise, pre-prepared statement in the local language, that explains the state of scientific knowledge and the difference between prediction, early warning, or forecasts. &nbsp

In recent years, earthquake felt reports contributed via online systems have provided increasingly valuable sources of data to characterize earthquakes and their effects. Contributed felt reports are accompanied by increases in website traffic, which are themselves potentially useful for the early detection of seismic events. In February 2017 the European-Mediterranean Seismic Centre detected an unusual surge in traffic from the Punjab region in northwestern India, although no nearby seismic event was detected instrumentally. Had crowdsourcing detected a felt earthquake that instruments had missed? Or did Punjab cry wolf? In this Earthquake Lites report, we describe the sleuthing endeavor undertaken to find an answer.

Earthquake early warning systems based on smartphone networks are emerging as complementary systems to the more expensive systems based on scientific-grade instruments. Hence, there is a need to better understand their detection capabilities. This article introduces a probabilistic framework for modeling the interaction between a smartphone network and seismic events to provide estimates of the detection probability for a given earthquake and to assess how the network geometry affects the detection delay. The framework was used to study the detection capability of the first operational smartphone-based earthquake early warning system implemented by the Earthquake Network (EQN) initiative, which started in 2013 and has issued more than 5500 warnings in 25 countries. The analysis showed that the probability of detection of an earthquake depends on the interaction between the network geometry and the earthquake parameters and that the detection probability is greatly affected by the population spatial distribution. Countries that benefit most from the EQN initiative are those without large gaps in the geographic distribution of their population.

Public earthquake early warning systems have the potential to reduce individual risk by warning people of an incoming tremor but their development has been hampered by costly infrastructure. Furthermore, users' understanding of such a service and their reactions to warnings remains poorly studied. The smartphone app of the Earthquake Network initiative turns users' smartphones into motion detectors and provides the first example of purely smartphone-based earthquake early warnings, without the need for dedicated seismic station infrastructure and operating in multiple countries. We demonstrate here that early warnings have been emitted in multiple countries even for damaging shaking levels and so this offers an alternative in the many regions unlikely to be covered by conventional early warning systems in the foreseeable future. We also show that although warnings are understood and appreciated by users, notably to get psychologically prepared, only a fraction take protective actions such as "drop, cover and hold"., Second version, 19 pages, 8 figures

We present a general-purpose numerical quantum mechanical solver using Schrodinger-Poisson equations called Aestimo 1D. The solver provides self-consistent solutions to the Schrodinger and Poisson equations for a given semiconductor heterostructure built with materials including elementary, binary, ternary, and quaternary semiconductors and their doped structures. The software can be used to calculate electronic band structures of heterostructures either using a single-band or multi-band k.p envelope function approximation. The software is fully open-source and it is released under the GNU general public license version 3 for full freedom of usage for applications in the fields of nano-electronics, optoelectronics, and solid-state device simulations.

Over the past decade technologies and social media have been praised a revolution in the way seismic risk and information was communicated to the public. For instance, LastQuake system is crowdsourcing earthquake detections and providing timely information and safety tips to citizens through social media and a free app now used by over 900K users over the world. Through a series of other practical examples and case studies, among which Earthquake Network system and Raspberry Shakes use, we show that smartphones and social media along with other technologies have indeed shaped new ways to detect earthquakes. They also enable to collect key information in order to raise situational awareness and in the end, inform the public in a timely and geotargeted manner, passing from a top-down approach to a two-way communication. Technology use also led to a significant increase of citizens’ role and implication in seismology, not only raising their interest for the risk but also for the science that relies beneath it.Our analysis demonstrates that in order to be successful, and thus to reduce anxiety and create a trust relationship between scientists and citizens, efficient communication strategies must be based on a thorough knowledge of both risk culture and technological culture. Indeed, such assessment of the audience enables to better meet public’s various information needs in terms of content, format and time frame.However, technologies as well as their uses have kept evolving and seismologists are now facing new challenges to communicate key information. For instance, in an increasing number of cases, misinformation and rumours about earthquake predictions become viral on social media. This is a critical issue to be addressed, especially in a context of development of both earthquake early warning systems and earthquake operational forecast. Additionally, citizen communication and information routines are evolving, especially with the rise of messaging apps or the development of new social media. However, to date, messaging apps are not designed in a way that facilitates communication of critical seismic information by seismic institutions.We conclude that lessons learned from previous challenges, especially through a constant return of experience process, will be useful to address contemporary ones. Communicating towards the public is a necessity during all phases of the crisis cycle, from a scientific and risk perspective. Getting to know the audience’s needs, habits, language, emotions or cultural background and show them empathy is a critical part of efficient communication strategies. Finally, technologies should be seized as an opportunity to engage with citizens and build a lasting trust relationship.

Detection of earthquakes by seismic networks has been accelerated on a global scale using crowdsourced data., In many cases, it takes several minutes after an earthquake to publish online a seismic location with confidence. Via monitoring for specific types of increased website, app, or Twitter usage, crowdsourced detection of seismic activity can be used to “seed” the search in the seismic data for an earthquake and reduce the risk of false detections, thereby accelerating the publication of locations for felt earthquakes. We demonstrate that this low-cost approach can work at the global scale to produce reliable and rapid results. The system was retroactively tested on a set of real crowdsourced detections of earthquakes made during 2016 and 2017, with 50% of successful locations found within 103 s, 76 s faster than GEOFON and 271 s faster than the European-Mediterranean Seismological Centre’s publication times, and 90% of successful locations found within 54 km of the final accepted epicenter.

We present the first hybrid-integrated optical phase-lock loop (OPLL) for use in high spectral purity photonic terahertz sources. We have achieved the necessary short loop delay to lock a 1-MHz linewidth slave laser by hybrid integration of the slave laser and photodetector on a silicon motherboard with silica optical waveguides and combining this with a custom-designed low-delay electronic loop filter circuit. The laser and photodetectors are InP-based and are flip chip bonded to silicon daughter boards, which are in turn attached to the motherboard. Delay between the slave laser and photodiode was approximately 50 ps. The heterodyne between slave and master sources has a linewidth of less than 1 kHz and achieved phase noise less than -80 dBc/Hz at an offset of 10 kHz. The slave laser can be offset from the master source by 2-7 GHz, using a microwave oscillator. This integrated OPLL circuit was used with an optical comb source and an injection-locked laser comb filter to generate high spectral purity signals at frequencies up to 300 GHz with linewidths

Rapid assessment of a global earthquake’s impact, focusing on damage caused by ground shaking (rather than secondary effects such as fires, tsunamis, landslides…), relies first on the spatial distribution of earthquake shaking as estimated by ground-motions prediction equations and on the building stock inventory and related vulnerability (Erdik et al. 2011). However, the variability of the ground-motion predictions model is significant (e.g., Atik et al. 2010), and at the global scale, building stock inventory and related vulnerability are difficult to evaluate with sufficient accuracy and spatial resolution (Porter et al. 2008) leading to uncertainties in impact assessments.

PurposeThis paper was written to help practitioners in the field of arts‐based learning understand the impact that training with its roots in theatre can have and has had on business executives – and the causes of that impact.Design/methodology/approachThe paper was developed by examining the 17‐year experience of Performance Plus… in delivering theatre‐based training to a wide range of large US businesses. It examines the way that drama can affect people in the audience and then, more particularly, how theatre based training affected the behaviors and actions of key management participants. The article then connected those results to the work of philosopher E.F. Schumacher and social scientist Daniel Goleman.FindingsThe fundamental conclusion of the paper is that drama is an extremely effective tool for helping people learn skills and behaviors they can apply in the everyday routine of business.Originality/valueBecause so little has been written about theatre‐based training, the primary value of this paper is to open readers’ eyes to a new and powerful way to train business executive – and to outlines a few of the many ways that approach can be taken to ensure that management participants in training programs are actively involved and engaged in the programs being presented and as a result embrace the learning from the program in a lasting way.

We present results for an heterodyne optical phase-lock loop (OPLL), monolithically integrated on InP with external phase detector and loop filter, which phase locks the integrated laser to an external source, for offset frequencies tuneable between 0.6 GHz and 6.1 GHz. The integrated semiconductor laser emits at 1553 nm with 1.1 MHz linewidth, while the external laser has a linewidth less than 150 kHz. To achieve high quality phase locking with lasers of these linewidths, the loop delay has been made less than 1.8 ns. Monolithic integration reduces the optical path delay between the laser and photodiode to less than 20 ps. The electronic part of the OPLL was implemented using a custom-designed feedback circuit with a propagation delay of ~1 ns and an open-loop bandwidth greater than 1 GHz. The heterodyne signal between the locked slave laser and master laser has phase noise below −90 dBc/Hz for frequency offsets greater than 20 kHz and a phase error variance in 10 GHz bandwidth of 0.04 rad2.

A tuneable terahertz source based on the first hybrid integrated optical phase-lock loop is presented. Generated signals have linewidth

A photonic technique for generating high-purity millimetre-wave or terahertz signals based on heterodyne of two phase-locked optical sources is described. Technology requirements and potential applications are discussed.

A bonded rhomb sample geometry is used to study the spin-dependent absorption characteristics of an intersubband transition in the conduction band of a GaAs/AlGaAs quantum well. Optical saturation experiments, using linearly and circularly polarized beams, were compared to measure the population relaxation time of the upper subband and the degree to which spin polarization is occurring in the electron population. In sharp contrast to previous interband absorption studies, the intersubband data are consistent with a picture in which the angular momentum of the incident photons appears to bypass the electron system completely and instead exerts a direct torque on the crystal lattice.

Intersubband transitions within the conduction band in semiconductor quantum wells have been widely explored, which eventually led to their application in quantum well infrared photodetectors and quantum cascade lasers (QCLs). There have been considerably fewer studies of hole intersubband transitions, which are more complicated than their electronic counterparts. They are very interesting, however, because of optical activity for both TM and TE light polarization, offering the possibility of both edge and surface-normal emission or absorption. Earlier studies have mostly focused on bound- continuum transitions in GaAs/AlGaAs and Si/SiGe systems for infrared detection.

We describe two metamaterial waveguide designs which display negative refraction. Both use quantum well nanostructures to engineer tunable resonances in the dielectric response, which can be designed using the rules of quantum mechanics. One uses coupling to a ``plasmonic'' resonance in adjacent metallic layers to enhance the size of the negative refraction effect. The negative refraction appears close to the quantum well intersubband transition energy, and is sensitive to the two-dimensional concentration of electrons within the wells and in adjacent conducting layers, thus offering the potential for switchable devices. These ``quantum metamaterials'' are highly distributed multilayered optically anisotropic systems with comparatively low absorption in the negatively refracting spectral region, and they can readily be grown by conventional semiconductor epitaxial growth technologies.

In 2006, we began monitoring hand hygiene compliance by direct observation. In 2006, with no changes in the methicillin-resistant Staphylococcus aureus (MRSA) control program, a 38% reduction of facility-acquired rates for this organism was realized. These results indicate that focused monitoring of hand hygiene can reduce facility-acquired rates of MRSA.

Optical saturation experiments have been performed on hh1-hh2 intersubband transitions in two samples of p-doped GaAs∕AlGaAs quantum wells. The transitions had energies of 183 and 160meV and the measured population relaxation times were 2±1.5 and 0.3±0.1ps, respectively. Modeling of the quantum wells with a 6×6 k⋅p method shows that intersubband scattering by LO phonons can account for these relaxation times. The valence bandstructure is typically more complicated than the conduction bandstructure in a quantum well but these measurements show that LO phonons are the dominant intersubband scattering mechanism in both cases.

A pulsed midinfrared photoconductivity study of electron recapture in dot-in-a-well infrared photodetectors yields bias-dependent electron-capture lifetimes in the range of 3–600ns and photoconductive gain factors of ∼104–105. The dependence of the lifetimes on temperature and electric field argues for these surprisingly long values being due to electron intervalley transfer. Under normal device operating conditions, photoexcited electrons transfer efficiently out of the central GaAs Γ minimum into the high energy L and X valleys, where they couple only weakly to the Γ-like confined states in the InAs dots.

Public earthquake early warning systems have the potential to reduce individual risk by warning people of approaching tremors, but their development has been hampered by costly infrastructure. Furthermore, both users’ understanding of such a service and their reactions to actual warnings have been the topic of only a few surveys. The smartphone app of the Earthquake Network initiative utilizes users’smartphones asmotion detectors and provides the first example of a purely smartphone-based earthquake early warning system, without the need for dedicated seismic station infrastructure and operating in multiple countries. We demonstrate that this system has issued early warnings in multiple countries, including for damaging shaking levels, and hence that this offers an alternative to conventional early warning systems in the foreseeable future. We also show that although warnings are understood and appreciated by users, notably to get psychologically prepared, only a fraction take protective actions such as “drop, cover, and hold.&rdquo

The European Mediterranean Seismological Centre (EMSC), one of the top global earthquake information centers, has been empirically developing a multichannel rapid information system comprising websites, a Twitter quakebot, and a smartphone app for global earthquake eyewitnesses. At the intersection between seismology, citizen science, and digital communication, its aim is twofold: to offer timely, appropriate information in regions where an earthquake is felt and to collect high numbers of eyewitnesses’ direct and indirect observations about the degree of shaking being felt and possible damage incurred. This, in turn, will improve rapid situation awareness and augment data at a relatively low cost. Engagement with eyewitnesses is based on the rapid provision of tremor detection (between few tens of seconds to a couple of minutes from when the earthquake strikes) which is derived from the analysis of indirect information, i.e., digital footprints of Internet and social media searches by eyewitnesses eager to find out the cause of the tremor. This detection generally precedes detection by seismic networks. Eyewitness’ behavior is comparable to real-time seismic sensors when using EMSC websites or LastQuake smartphone app. The hit times on our websites and launch times of our app closely follow seismic wave propagation. Crowdsourced data (felt reports, geo-located pictures, and open comments) is then fed back into the ongoing information product improvement and situation awareness which, in turn, attracts more eyewitnesses through a viral spread, thus creating a positive feedback loop. The use of visual communication for felt report collection, where traditional online questionnaires have been replaced by cartoons depicting different degrees of shaking and damage levels, has proven to be fast and efficient on a global scale with, on average, half of the felt reports being collected within 10 min. Following requests by Nepalese users after the devastating 2015 Gorkha, Nepal earthquake, the LastQuake app now includes timely geo-targeted safety checks to inform loved ones that one is safe and safety tips communicated using cartoons to describe behaviors to be encouraged or avoided after violent tremors. We argue that this simple and affordable system, based on standard Internet technologies and social media, can reduce anxiety by offering timely information and services to eyewitnesses and possibly contribute to immediate global seismic risk reduction by complementing well-established long-term strategies built around improving the seismic performance of the existing buildings by raising situation awareness and limiting potentially dangerous behaviors after violent ground shaking. Short abstract The EMSC, one of the top global earthquake information centers, has been empirically developing a multichannel rapid information system comprising websites, a Twitter quakebot and a smartphone app for global earthquake eyewitnesses. At the intersection between seismology, citizen science, and digital communication, its aim is twofold: to offer timely, appropriate information in regions where an earthquake is felt and to collect high numbers of eyewitnesses’ direct and indirect observations to improve rapid situation awareness. Engagement with eyewitnesses is based on the rapid provision of tremor detection (between few tens of seconds to a couple of minutes) which is derived from the analysis of indirect information, i.e., Internet and social media searches by eyewitnesses eager to find out the cause of the tremor. Eyewitness’ behavior is comparable to real-time seismic sensors when using EMSC websites or LastQuake smartphone app. Crowdsourced data is then fed back into the ongoing information product improvement and situation awareness which, in turn, attracts more eyewitnesses through a viral spread. The use of visual communication for felt report collection has proven to be fast and efficient on a global scale with, on average, 50% of felt reports being collected within 10 min. The LastQuake app now includes timely geo-targeted safety checks and safety tips to describe behaviors to be encouraged or avoided after violent tremors. We argue that this simple,affordable system, based on Internet technologies and social media, can reduce anxiety by offering timely information to eyewitnesses and possibly contribute to immediate global seismic risk reduction.

The collection of earthquake testimonies (i.e., qualitative descriptions of felt shaking) is essential for macroseismic studies (i.e., studies gathering information on how strongly an earthquake was felt in different places), and when done rapidly and systematically, improves situational awareness and in turn can contribute to efficient emergency response. In this study, we present advances made in the collection of testimonies following earthquakes around the world using a thumbnail‐based questionnaire implemented on the European‐Mediterranean Seismological Centre (EMSC) smartphone app and its website compatible for mobile devices. In both instances, the questionnaire consists of a selection of thumbnails, each representing an intensity level of the European Macroseismic Scale 1998. We find that testimonies are collected faster, and in larger numbers, by way of thumbnail‐based questionnaires than by more traditional online questionnaires. Responses were received from all seismically active regions of our planet, suggesting that thumbnails overcome language barriers. We also observed that the app is not sufficient on its own, because the websites are the main source of testimonies when an earthquake strikes a region for the first time in a while; it is only for subsequent shocks that the app is widely used. Notably though, the speed of the collection of testimonies increases significantly when the app is used. We find that automated EMSC intensities as assigned by user‐specified thumbnails are, on average, well correlated with “Did You Feel It?” (DYFI) responses and with the three independently and manually derived macroseismic datasets, but there is a tendency for EMSC to be biased low with respect to DYFI at moderate and large intensities. We address this by proposing a simple adjustment that will be verified in future earthquakes. NRF (Natl Research Foundation, S’pore) MOE (Min. of Education, S’pore) Published version