757 research outputs found

    ERS-1 SAR data processing

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    To take full advantage of the synthetic aperature radar (SAR) to be flown on board the European Space Agency's Remote Sensing Satellite (ERS-1) (1989) and the Canadian Radarsat (1990), the implementation of a receiving station in Alaska is being studied to gather and process SAR data pertaining in particular to regions within the station's range of reception. The current SAR data processing requirement is estimated to be on the order of 5 minutes per day. The Interim Digital Sar Processor (IDP) which was under continual development through Seasat (1978) and SIR-B (1984) can process slightly more than 2 minutes of ERS-1 data per day. On the other hand, the Advanced Digital SAR Processore (ADSP), currently under development for the Shuttle Imaging Radar C (SIR-C, 1988) and the Venus Radar Mapper, (VMR, 1988), is capable of processing ERS-1 SAR data at a real time rate. To better suit the anticipated ERS-1 SAR data processing requirement, both a modified IDP and an ADSP derivative are being examined. For the modified IDP, a pipelined architecture is proposed for the mini-computer plus array processor arrangement to improve throughout. For the ADSP derivative, a simplified version is proposed to enhance ease of implementation and maintainability while maintaing real time throughput rates. These processing systems are discussed and evaluated

    Predictive nonlinear biplots: maps and trajectories

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    When the difference between samples is measured using a Euclidean embeddable dissimilarity function, observations and the associated variables can be displayed on a nonlinear biplot. Furthermore, a nonlinear biplot is predictive if information on variables is added in such a way that it allows the values of the variables to be estimated for points in the biplot. In this paper an r dimensional biplot which maps the predicted value of a variable for every point in the plot, is introduced. Using such maps it is shown that even with continuous data, predicted values do not always vary continuously across the biplot plane. Prediction trajectories that appropriate for summarising such non-continuous prediction maps are also introduced. These prediction trajectories allow information about two or more variables to be estimated even when the underlying predicted values do not vary continuously

    Journal Staff

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    The aluminum–zinc-vacancy (Al Zn −V Zn ) complex is identified as one of the dominant defects in Al-containing n -type ZnO after electron irradiation at room temperature with energies above 0.8 MeV. The complex is energetically favorable over the isolated V Zn , binding more than 90% of the stable V Zn ’s generated by the irradiation. It acts as a deep acceptor with the (0/− ) energy level located at approximately 1 eV above the valence band. Such a complex is concluded to be a defect of crucial and general importance that limits the n -type doping efficiency by complex formation with donors, thereby literally removing the donors, as well as by charge compensation

    Integrated regional vulnerability assessment of government services to climate change

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    © Emerald Group Publishing Limited. Purpose – This paper aims to describe the conduct and outcomes of an integrated assessment (IA) of the vulnerability to climate change of government service provision at regional scale in New South Wales, Australia. The assessment was co-designed with regional public sector managers to address their needs for an improved understanding of regional vulnerabilities to climate change and variability. Design/methodology/approach – The study used IA of climate change impacts through a complex adaptive systems approach incorporating social learning and stakeholder-led research processes. Workshops were conducted with stakeholders from NSW government agencies, state-owned corporations and local governments representing the tourism, water, primary industries, human settlements, emergency management, human health, infrastructure and natural landscapes sectors. Participants used regional socioeconomic profiling and climate projections to consider the impacts on and the need to adapt community service provision to future climate. Findings – Many sectors are currently experiencing difficulty coping with changes in regional demographics and structural adjustment in the economy. Climate change will result in further impacts on already vulnerable systems in the forms of resource conflicts between expanded human settlements, the infrastructure that supports them and the environment (particularly for water); increased energy costs; and declining agricultural production and food security. Originality/value – This paper describes the application of meta-analysis in climate change policy research and frames climate change as a problem of environmental pollution and an issue of development and social equity

    Identifying Key Constructs and Measurements to Assess the Situation Analysis Reports

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    Every five years, unit offices of Virginia Cooperative Extension (VCE) must submit a situation analysis (SA) report. The purpose of the SA report is to identify the current issues at the local level to develop future educational programs. The primary objective of this study was to develop a methodology that could be used to assess the quality of SA reports in Virginia. We have evaluated 196 SA reports from VCE to begin development of an assessment. Results of testing of the tool identify areas for continued development

    Recruitment of Reviewers Is Becoming Harder at Some Journals: A Test of the Influence of Reviewer Fatigue at Six Journals in Ecology and Evolution

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    Background: It is commonly reported by editors that it has become harder to recruit reviewers for peer review and that this is because individuals are being asked to review too often and are experiencing reviewer fatigue. However, evidence supporting these arguments is largely anecdotal. Main body: We examine responses of individuals to review invitations for six journals in ecology and evolution. The proportion of invitations that lead to a submitted review has been decreasing steadily over 13 years (2003–2015) for four of the six journals examined, with a cumulative effect that has been quite substantial (average decline from 56% of review invitations generating a review in 2003 to just 37% in 2015). The likelihood that an invitee agrees to review declines significantly with the number of invitations they receive in a year. However, the average number of invitations being sent to prospective reviewers and the proportion of individuals being invited more than once per year has not changed much over these 13 years, despite substantial increases in the total number of review invitations being sent by these journals—the reviewer base has expanded concomitant with this growth in review requests. Conclusions: The proportion of review invitations that lead to a review being submitted has been declining steadily for four of the six journals examined here, but reviewer fatigue is not likely the primary explanation for this decline

    Judicial Work and Traumatic Stress: Vilification, Threats, and Secondary Trauma on the Bench

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    This article reports the results of a survey of judicial officers’ exposure to potentially traumatic stressors in a single state in Australia. An online survey was fully or partially completed by 205 serving and retired members of state courts between June and August of 2019. Respondents answered questions in a Yes/No and Likert scale format and provided comments on their experience and recommendations for the future. The survey focused on the prevalence and impact of three kinds of traumatic stress: threats to the person, vicarious trauma, and vilification. It sought to measure prevalence and to identify how different events in the workplace impacted psychological wellbeing and traumatic stress. The overall response rate was 55.3%, with 205 out of 371 judicial officers providing a full or partial response. The results indicated that 61% of respondents had experienced threats of violence to themselves or someone close to them. Three quarters (75.1%) of respondents reported being exposed to events associated with vicarious trauma, and 61 (29.7%) reported symptoms consistent with trauma-related effects. Just over half (52.7%) reported instances of harsh public criticism amounting to vilification. On the Kessler 10 scale of psychological distress 25.9% scored in the “moderate” range, 18.9% in the “high” range, and 9.8% in the “very high” range, much higher than the general population’s distress distribution. Respondents also rated the usefulness of current support resources and made recommendation for future resources

    Bandgap narrowing in Mn doped GaAs probed by room-temperature photoluminescence

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    The electronic band structure of the (Ga,Mn)As system has been one of the most intriguing problems in solid state physics over the past two decades. Determination of the band structure evolution with increasing Mn concentration is a key issue to understand the origin of ferromagnetism. Here we present room temperature photoluminescence and ellipsometry measurements of Ga_{100%-x}Mn_{x}As alloy. The up-shift of the valence-band is proven by the red shift of the room temperature near band gap emission from the Ga_{100%-x}Mn_{x}As alloy with increasing Mn content. It is shown that even a doping by 0.02 at.% of Mn affects the valence-band edge and it merges with the impurity band for a Mn concentration as low as 0.6 at.%. Both X-ray diffraction pattern and high resolution cross-sectional TEM images confirmed full recrystallization of the implanted layer and GaMnAs alloy formation.Comment: 24 pages, 7 figures, accepted at Phys. Rev. B 201
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