Composing Citizens: Epistemic Work in the Interstices of Comprehensive- Planning Genre Systems

This case-study examines the ways citizens took up, and in some ways resisted, city planners’ assumptions about their lived experience of “Portstown.” While it is necessary to acknowledge the coercive properties of institutional documents and genre-systems, community-literacy workers must not efface the epistemic potential of everyday compositions, for this quality creates opportunities for strategic interventions in the solicitation and reception of civic writing

<i>AKARI</i>/IRC source catalogues and source counts for the IRAC Dark Field, ELAIS North and the <i>AKARI</i> Deep Field South

We present the first detailed analysis of three extragalactic fields (IRAC Dark Field, ELAIS-N1, ADF-S) observed by the infrared satellite, AKARI, using an optimized data analysis toolkit specifically for the processing of extragalactic point sources. The InfaRed Camera (IRC) on AKARI complements the SpitzerSpace Telescope via its comprehensive coverage between 8–24 μm filling the gap between the Spitzer/IRAC and MIPS instruments. Source counts in the AKARI bands at 3.2, 4.1, 7, 11, 15 and 18 μm are presented. At near-infrared wavelengths, our source counts are consistent with counts made in other AKARI fields and in general with SpitzerIRAC (except at 3.2 μm where our counts lie above). In the mid-infrared (11 – 18 μm), we find our counts are consistent with both previous surveys by AKARI and the Spitzer peak-up imaging survey with the InfraRed Spectrograph (IRS). Using our counts to constrain contemporary evolutionary models, we find that although the models and counts are in agreement at mid-infrared wavelengths there are inconsistencies at wavelengths shortward of 7 μm, suggesting either a problem with stellar subtraction or indicating the need for refinement of the stellar population models. We have also investigated the AKARI/IRC filters, and find an active galactic nucleus selection criteria out to z AKARI 4.1, 11, 15 and 18 μm colours

Plasma-tail activity and the interplanetary medium at Halley's Comet during Armada Week: 6-14 March 1986

The encounters of five spacecraft with Halley's Comet during 6-14 March 1986 offered a unique opportunity to calibrate the solar-wind interaction with cometary plasmas as recorded by remote wide-field and narrow-field/narrowband imaging. Perhaps not generally recognized in the comet community is the additional opportunity offered by the Halley Armada to study the structure of the solar-wind and interplanetary magnetic field (IMF) in three dimensions using five sets of data obtained over similar time intervals and heliocentric distances, but at somewhat different heliolatitudes. In fact, the two problems, i.e., comet physics and the structure of the interplanetary medium, are coupled if one wants to understand what conditions pertained at the comet between the encounters. This relationship is discussed

Tracking icebergs with time-lapse photography and sparse optical flow, LeConte Bay, Alaska, 2016–2017

We present a workflow to track icebergs in proglacial fjords using oblique time-lapse photos and the Lucas-Kanade optical flow algorithm. We employ the workflow at LeConte Bay, Alaska, where we ran five time-lapse cameras between April 2016 and September 2017, capturing more than 400 000 photos at frame rates of 0.5–4.0 min−1. Hourly to daily average velocity fields in map coordinates illustrate dynamic currents in the bay, with dominant downfjord velocities (exceeding 0.5 m s−1 intermittently) and several eddies. Comparisons with simultaneous Acoustic Doppler Current Profiler (ADCP) measurements yield best agreement for the uppermost ADCP levels (∼ 12 m and above), in line with prevalent small icebergs that trace near-surface currents. Tracking results from multiple cameras compare favorably, although cameras with lower frame rates (0.5 min−1) tend to underestimate high flow speeds. Tests to determine requisite temporal and spatial image resolution confirm the importance of high image frame rates, while spatial resolution is of secondary importance. Application of our procedure to other fjords will be successful if iceberg concentrations are high enough and if the camera frame rates are sufficiently rapid (at least 1 min−1 for conditions similar to LeConte Bay).This work was funded by the U.S. National Science Foundation (OPP-1503910, OPP-1504288, OPP-1504521 and OPP-1504191).Ye

Charge transfer efficiency in a p-channel CCD irradiated cryogenically and the impact of room temperature annealing

It is important to understand the impact of the space radiation environment on detector performance, thereby ensuring that the optimal operating conditions are selected for use in flight. The best way to achieve this is by irradiating the device using appropriate mission operating conditions, i.e. holding the device at mission operating temperature with the device powered and clocking. This paper describes the Charge Transfer Efficiency (CTE) measurements made using an e2v technologies p-channel CCD204 irradiated using protons to the 10 MeV equivalent fluence of 1.24×109 protons.cm-2 at 153 K. The device was held at 153 K for a period of 7 days after the irradiation before being allowed up to room temperature where it was held at rest, i.e. unbiased, for twenty six hours to anneal before being cooled back to 153 K for further testing, this was followed by a further one week and three weeks of room temperature annealing each separated by further testing. A comparison to results from a previous room temperature irradiation of an n-channel CCD204 is made using assumptions of a factor of two worse CTE when irradiated under cryogenic conditions which indicate that p-channel CCDs offer improved tolerance to radiation damage when irradiated under cryogenic conditions

Droplet Combustion Experiment (DCE)

The first space-based experiments were performed on the combustion of free, individual liquid fuel droplets in oxidizing atmospheres. The fuel was heptane, with initial droplet diameters ranging about from 1 mm to 4 mm. The atmospheres were mixtures of helium and oxygen, at pressures of 1.00, 0.50 and 0.25 bar, with oxygen mole fractions between 20% and 40%, as well as normal Spacelab cabin air. The temperatures of the atmospheres and of the initial liquid fuel were nominally 300 K. A total of 44 droplets were burned successfully on the two flights, 8 on the shortened STS-83 mission and 36 on STS-94. The results spanned the full range of heptane droplet combustion behavior, from radiative flame extinction at larger droplet diameters in the more dilute atmospheres to diffusive extinction in the less dilute atmospheres, with the droplet disappearing prior to flame extinction at the highest oxygen concentrations. Quasisteady histories of droplet diameters were observed along with unsteady histories of flame diameters. New and detailed information was obtained on burning rates, flame characteristics and soot behavior. The results have motivated new computational and theoretical investigations of droplet combustion, improving knowledge of the chemical kinetics, fluid mechanics and heat and mass transfer processes involved in burning liquid fuels

Gaia CCDs: charge transfer inefficiency measurements between five years of flight

The European Space Agency’s Gaia spacecraft was launched in December 2013 and has been in orbit at the Earth-Sun Lagrange point 2 (L2) for over 6 years. The spacecraft measures the positions, distances, space motions and many other physical characteristics of around one billion stars in the Milky Way and beyond. It has a focal plane of 106 Charge-Coupled Devices (CCDs) which have all been performing well but have been measuring a small but quantifiable degradation in performance in time due to Non-Ionizing Energy Loss (NIEL) damage from interstellar radiation. This NIEL damage produces trap defects which can capture charge from signals and reduces the quality of the data. Gaia’s original mission lifetime was planned to be around 5 years and the pre-flight testing and radiation damage analysis was tailored around those timescales as well as with the projected solar activity before launch. Closer to the time of launch and during Gaia’s years of orbit, it has been noted that the solar activity was lower than what was initially predicted. From the previous analysis of in-flight data in 2016, it was calculated that Gaia was experiencing an order of magnitude less radiation damage than was predicted. This paper describes the analysis of charge calibration data and corresponding Charge Transfer Inefficiency (CTI) measurements from the in-flight CCDs, both near the beginning of the mission and after more than 5 years in orbit to quantify the radiation damage impact. These sets of results can be compared with those from the pre-flight tests which can be used to evaluate and understand the differences between the on-ground and in-flight results

Visual Affect Around the World: A Large-scale Multilingual Visual Sentiment Ontology

Every culture and language is unique. Our work expressly focuses on the uniqueness of culture and language in relation to human affect, specifically sentiment and emotion semantics, and how they manifest in social multimedia. We develop sets of sentiment- and emotion-polarized visual concepts by adapting semantic structures called adjective-noun pairs, originally introduced by Borth et al. (2013), but in a multilingual context. We propose a new language-dependent method for automatic discovery of these adjective-noun constructs. We show how this pipeline can be applied on a social multimedia platform for the creation of a large-scale multilingual visual sentiment concept ontology (MVSO). Unlike the flat structure in Borth et al. (2013), our unified ontology is organized hierarchically by multilingual clusters of visually detectable nouns and subclusters of emotionally biased versions of these nouns. In addition, we present an image-based prediction task to show how generalizable language-specific models are in a multilingual context. A new, publicly available dataset of >15.6K sentiment-biased visual concepts across 12 languages with language-specific detector banks, >7.36M images and their metadata is also released.Comment: 11 pages, to appear at ACM MM'1

Trap pumping schemes for the Euclid CCD273 detector: characterisation of electrodes and defects

The VISible imager instrument (VIS) on board the Euclid mission will deliver high resolution shape measurements of galaxies down to very faint limits (R ~ 25 at 10σ) in a large part of the sky, in order to infer the distribution of dark matter in the Universe. To help mitigate radiation damage effects that will accumulate in the detectors over the mission lifetime, the properties of the radiation induced traps needs to be known with as high precision as possible. For this purpose the trap pumping method will be employed as part of the in-orbit calibration routines. Using trap pumping it is possible to identify and characterise single traps in a Charge-Coupled Device (CCD), thus providing information such as the density, emission time constants and sub-pixel positions of the traps in the detectors. This paper presents the trap pumping algorithms used for the radiation testing campaign of the CCD273 detectors, performed by the Centre for Electronic Imaging (CEI) at the Open University, that will be used for the VIS instrument. The CCD273 is a four-phase device with uneven phase widths, which complicates the trap pumping analysis. However, we find that by optimising the trap pumping algorithms and analysis routines, it is possible to obtain sub-pixel and even sub-phase positional information about the traps. Further, by comparing trap pumping data with simulations, it is possible to gain more information about the effective electrode widths of the device

Relationship between solar energetic oxygen flux and MHD shock Mach number

This study correlates the time-intensity profile of a magnetohydrodynamic (MHD) shock with the corresponding solar energetic oxygen for a coronal mass ejection (CME) event that occurred on October 28, 2003. The intensity of MHD shock, in terms of Mach number, is simulated using a 1.5D MHD code, whereas the solar energetic oxygen flux is observed by the Solar Isotope Spectrometer (SIS) on board the Advanced Composition Explorer (ACE) spacecraft. A good correlation (Pearson correlation coefficient: r = 0.70 – 0.84) is found between the forward fast-mode shock Mach number and the hourly-averaged, logarithmic oxygen differential energy flux for 7 energy channels (7.3 – 63.8 MeV). We suspect that the intensity-time profile of high energy SEP events is manifested by the strength (Mach number) of CME-driven propagation shocks. While further studies with more events are required to be more conclusive, this study result provides a direction for future studies or predictions of SEP fluxes