City managers matter in how cities engage with their citizens

Social media and other online innovations allow city managers to engage with their citizenry in new - and often relatively inexpensive - ways. But why have some cities embraced and adopted these technologies while others have lagged behind? In new research which draws on a survey of 2,500 managers in 500 cities, Fengxiu Zhang and Mary K. Feeney find that ..

Investigation of field emission electron guns for gas lasers

Issued as Quarterly progress letter 1-5, and Final report, Projects E-18-606 and E-21-63

Lockheed/Georgia Tech Cooperative VLSI Program

Issued as Monthly letter reports, nos. 1-9, Project no. E-21-640 (subproject B-10-601

SSSpaNG! Stellar Spectra as Sparse, data-driven, Non-Gaussian processes

Upcoming million-star spectroscopic surveys have the potential to revolutionize our view of the formation and chemical evolution of the Milky Way. Realizing this potential requires automated approaches to optimize estimates of stellar properties, such as chemical element abundances, from the spectra. The volume and quality of the observations strongly motivate that these approaches should be data-driven. With this in mind, we introduce SSSpaNG: a data-driven non-Gaussian Process model of stellar spectra. We demonstrate the capabilities of SSSpaNG using a sample of APOGEE red clump stars, whose model parameters we infer via Gibbs sampling. Pooling information between stars to infer their covariance, we permit clear identification of the correlations between spectral pixels. Harnessing these correlations, we infer the true spectrum of each star, inpainting missing regions and denoising by a factor of at least 2 for stars with signal-to-noise of ~20. As we marginalize over the covariance matrix of the spectra, the effective prior on these true spectra is non-Gaussian and sparsifying, favouring typically small but occasionally large excursions from the mean. The high-fidelity inferred spectra produced will enable improved elemental abundance measurements for individual stars. Our model also allows us to quantify the information gained by observing portions of a star's spectrum, and thereby define the most mutually informative spectral regions. Using 25 windows centred on elemental absorption lines, we demonstrate that the iron-peak and alpha-process elements are particularly mutually informative for these spectra, and that the majority of information about a target window is contained in the 10-or-so most informative windows. Such mutual-information estimates have the potential to inform models of nucleosynthetic yields and the design of future observations.Comment: Version published in MNRAS. 15 pages, 9 figures, code available from https://github.com/sfeeney/ddspectr

Feasibility and initial efficacy of project-based treatment for people with ABI

Background: Communication impairments are common and pervasive for people a long time following acquired brain injury (ABI). These impairments have a significant impact on a person's quality of life (QOL) post‐injury. Project‐based treatment is a treatment approach that could have an impact on communication skills and QOL for people with ABI a long‐term post‐injury. This treatment is embedded in a context of meaningful activities chosen by people with ABI, whereby, as a group, they work collaboratively to achieve a tangible end product. Aims: To evaluate the feasibility and initial efficacy of project‐based treatment on improving the communication skills and QOL for people with ABI. Methods & Procedures: An exploratory controlled trial with alternate allocation of groups, and follow‐up at 6–8 weeks, was completed. Twenty‐one people with chronic ABI were recruited in groups of two to three from community settings, allocated to either a TREATMENT (n = 11) or WAITLIST group (n = 10). Participants attended a 20‐h group‐based treatment over 6 weeks where they worked towards achieving a project that helped others. To determine feasibility, four criteria were used: demand, implementation, practicality and acceptability. A range of communication and QOL outcomes was used to determine a fifth feasibility criterion, initial efficacy. Some of these criteria were additionally used to evaluate the feasibility of the outcomes. Outcomes & Results: All participants received the treatment as allocated with high attendance and no dropouts. The treatment was feasible to deliver as intended and was highly acceptable to participants. Medium and large effect sizes were found from pre‐ to post‐treatment, and from pre‐treatment to follow‐up for measures of conversation, perceived communicative ability and QOL. Conclusions & Implications: Project‐based treatment is feasible with indications of initial efficacy for both communication skills and QOL. The treatment provides a promising new approach for improving communication skills and QOL in people with chronic acquired brain injuries in the community setting

The Self and Other: Portraying Israeli and Palestinian Identities on Twitter

The conflict between Israel and Palestine has lasted over half a century, with both sides enduring military and political turmoil. This paper explores how Twitter is being used as a medium to portray identities in the conflict. We examine the tweets contained in the @IDFspokesperson and @ISMPalestine Twitter accounts between late 2015 and early 2016. Using textual analysis, we gain an insight into how these Twitter accounts, defined by the conflict, are used in portraying the self and the other

Semantic-based policy engineering for autonomic systems

This paper presents some important directions in the use of ontology-based semantics in achieving the vision of Autonomic Communications. We examine the requirements of Autonomic Communication with a focus on the demanding needs of ubiquitous computing environments, with an emphasis on the requirements shared with Autonomic Computing. We observe that ontologies provide a strong mechanism for addressing the heterogeneity in user task requirements, managed resources, services and context. We then present two complimentary approaches that exploit ontology-based knowledge in support of autonomic communications: service-oriented models for policy engineering and dynamic semantic queries using content-based networks. The paper concludes with a discussion of the major research challenges such approaches raise