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Stephanie Smith

Bio: Stephanie Smith is an academic researcher from Commonwealth Scientific and Industrial Research Organisation. The author has contributed to research in topics: Antenna (radio) & Anechoic chamber. The author has an hindex of 15, co-authored 40 publications receiving 967 citations. Previous affiliations of Stephanie Smith include Edith Cowan University & Boston Children's Hospital.

Papers
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Journal ArticleDOI
21 Feb 2019-BMJ
TL;DR: TKA and UKA are both viable options for the treatment of isolated unicompartmental osteoarthritis by directly comparing the two treatments, and this study demonstrates better results for UKA in several outcome domains.
Abstract: Objective To present a clear and comprehensive summary of the published data on unicompartmental knee replacement (UKA) or total knee replacement (TKA), comparing domains of outcome that have been shown to be important to patients and clinicians to allow informed decision making. Design Systematic review using data from randomised controlled trials, nationwide databases or joint registries, and large cohort studies. Data sources Medline, Embase, Cochrane Controlled Register of Trials (CENTRAL), and Clinical Trials.gov, searched between 1 January 1997 and 31 December 2018. Eligibility criteria for selecting studies Studies published in the past 20 years, comparing outcomes of primary UKA with TKA in adult patients. Studies were excluded if they involved fewer than 50 participants, or if translation into English was not available. Results 60 eligible studies were separated into three methodological groups: seven publications from six randomised controlled trials, 17 national joint registries and national database studies, and 36 cohort studies. Results for each domain of outcome varied depending on the level of data, and findings were not always significant. Analysis of the three groups of studies showed significantly shorter hospital stays after UKA than after TKA (−1.20 days (95% confidence interval −1.67 to −0.73), −1.43 (−1.53 to −1.33), and −1.73 (−2.30 to −1.16), respectively). There was no significant difference in pain, based on patient reported outcome measures (PROMs), but significantly better functional PROM scores for UKA than for TKA in both non-trial groups (standard mean difference −0.58 (−0.88 to −0.27) and −0.29 (−0.46 to −0.11), respectively). Regarding major complications, trials and cohort studies had non-significant results, but mortality after TKA was significantly higher in registry and large database studies (risk ratio 0.27 (0.16 to 0.45)), as were venous thromboembolic events (0.39 (0.27 to 0.57)) and major cardiac events (0.22 (0.06 to 0.86)). Early reoperation for any reason was higher after TKA than after UKA, but revision rates at five years remained higher for UKA in all three study groups (risk ratio 5.95 (1.29 to 27.59), 2.50 (1.77 to 3.54), and 3.13 (1.89 to 5.17), respectively). Conclusions TKA and UKA are both viable options for the treatment of isolated unicompartmental osteoarthritis. By directly comparing the two treatments, this study demonstrates better results for UKA in several outcome domains. However, the risk of revision surgery was lower for TKA. This information should be available to patients as part of the shared decision making process in choosing treatment options. Systematic review registration PROSPERO number CRD42018089972.

196 citations

Book
15 Dec 2002
TL;DR: Switched parasitic antennas for cellular communications as mentioned in this paper have been used in a wide range of potential applications, such as direction finding and multibeam communications systems, with high-speed signal acquisition, fixed input impedance, low loss and small footprint.
Abstract: From the Publisher: "Switched Parasitic Antennas for Cellular Communications introduces practitioners to the basic concepts and wide range of potential applications of switched parasitic antennas, including smart antennas for wireless communications The book's clear, detailed discussion of design rules for both wire and patch antenna structures, together with their circuit requirements, offers the knowledge needed to successfully design and implement low-cost, small, switched parasitic antennas for a variety of uses" Presenting information typically not found in other books, the authors explore the numerous advantages of these antennas - including high-speed signal acquisition, fixed input impedance, low loss, and small footprint Professionals find practical design examples, strategies, and optimization methods for designing economical switched parasitic antennas for applications such as direction finding and multibeam communications systems Cutting-edge technologies and applications such as MEMs RF switches are also discussed

177 citations

Journal ArticleDOI
TL;DR: In this paper, the authors describe an ultra-widebandwidth, low-frequency receiver recently installed on the Parkes radio telescope, which provides continuous frequency coverage from 704 to 4032 MHz.
Abstract: We describe an ultra-wide-bandwidth, low-frequency receiver recently installed on the Parkes radio telescope. The receiver system provides continuous frequency coverage from 704 to 4032 MHz. For much of the band ( ), the system temperature is approximately 22 K and the receiver system remains in a linear regime even in the presence of strong mobile phone transmissions. We discuss the scientific and technical aspects of the new receiver, including its astronomical objectives, as well as the feed, receiver, digitiser, and signal processor design. We describe the pipeline routines that form the archive-ready data products and how those data files can be accessed from the archives. The system performance is quantified, including the system noise and linearity, beam shape, antenna efficiency, polarisation calibration, and timing stability.

112 citations

Journal ArticleDOI
Fernando Camilo, P. Scholz1, M. Serylak2, M. Serylak3  +215 moreInstitutions (22)
TL;DR: In this article, radio and X-ray observations of PSR J1622-4950 indicate that the magnetar, in a quiescent state since at least early 2015, reactivated between 2017 March 19 and April 5.
Abstract: New radio (MeerKAT and Parkes) and X-ray (XMM-Newton, Swift, Chandra, and NuSTAR) observations of PSR J1622-4950 indicate that the magnetar, in a quiescent state since at least early 2015, reactivated between 2017 March 19 and April 5. The radio flux density, while variable, is approximately 100 larger than during its dormant state. The X-ray flux one month after reactivation was at least 800 larger than during quiescence, and has been decaying exponentially on a 111 19 day timescale. This high-flux state, together with a radio-derived rotational ephemeris, enabled for the first time the detection of X-ray pulsations for this magnetar. At 5%, the 0.3-6 keV pulsed fraction is comparable to the smallest observed for magnetars. The overall pulsar geometry inferred from polarized radio emission appears to be broadly consistent with that determined 6-8 years earlier. However, rotating vector model fits suggest that we are now seeing radio emission from a different location in the magnetosphere than previously. This indicates a novel way in which radio emission from magnetars can differ from that of ordinary pulsars. The torque on the neutron star is varying rapidly and unsteadily, as is common for magnetars following outburst, having changed by a factor of 7 within six months of reactivation.

96 citations

Journal ArticleDOI
TL;DR: In this paper, the authors presented a design methodology for a compact low-cost partially reflecting surface (PRS) for a wideband high-gain resonant cavity antenna (RCA) which requires only a single commercial dielectric slab.
Abstract: This communication presents a design methodology for a compact low-cost partially reflecting surface (PRS) for a wideband high-gain resonant cavity antenna (RCA) which requires only a single commercial dielectric slab. The PRS has one nonuniform double-sided printed dielectric, which exhibits a negative transverse-reflection magnitude gradient and, at the same time, a progressive reflection phase gradient over frequency. In addition, a partially shielded cavity is proposed as a method to optimize the directivity bandwidth and the peak directivity of RCAs. A prototype of the PRS was fabricated and tested with a partially shielded cavity, showing good agreement between the predicted and measured results. The measured peak directivity of the antenna is 16.2 dBi at 11.4 GHz with a 3 dB bandwidth of 22%. The measured peak gain and 3 dB gain bandwidth are 15.75 dBi and 21.5%, respectively. The PRS has a radius of 29.25 mm ( $1.1\lambda _{0}$ ) with a thickness of 1.52 mm ( $0.12\lambda _{g}$ ), and the overall height of the antenna is $0.6\lambda _{0} $ , where $\lambda _{0}$ and $\lambda _{g}$ are the free-space and guided wavelengths at the center frequency of 11.4 GHz.

89 citations


Cited by
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15 Mar 1979
TL;DR: In this article, the experimental estimation of parameters for models can be solved through use of the likelihood ratio test, with particular attention to photon counting experiments, and procedures presented solve a greater range of problems than those currently in use, yet are no more difficult to apply.
Abstract: Many problems in the experimental estimation of parameters for models can be solved through use of the likelihood ratio test. Applications of the likelihood ratio, with particular attention to photon counting experiments, are discussed. The procedures presented solve a greater range of problems than those currently in use, yet are no more difficult to apply. The procedures are proved analytically, and examples from current problems in astronomy are discussed.

1,748 citations

01 Jan 2011
TL;DR: The study concludes that understanding lags first requires agreeing models, definitions and measures, which can be applied in practice, and a second task would be to develop a process by which to gather these data.
Abstract: This study aimed to review the literature describing and quantifying time lags in the health research translation process. Papers were included in the review if they quantified time lags in the development of health interventions. The study identified 23 papers. Few were comparable as different studies use different measures, of different things, at different time points. We concluded that the current state of knowledge of time lags is of limited use to those responsible for R&D and knowledge transfer who face difficulties in knowing what they should or can do to reduce time lags. This effectively ‘blindfolds’ investment decisions and risks wasting effort. The study concludes that understanding lags first requires agreeing models, definitions and measures, which can be applied in practice. A second task would be to develop a process by which to gather these data.

1,429 citations

Journal ArticleDOI
Abstract:

1,392 citations

01 Jan 2006
TL;DR: User experience surveys (UESs) are regarded as an important part of the overall performance framework for social care and, providing councils with information about how they might improve services locally, and are required to submit their results to government bodies so that the relative performance of the CSSRs can be judged.
Abstract: For some time now councils with social services responsibilities (CSSRs) have been required to conduct surveys of user’s experience of social services. These have taken place nationally in three-yearly cycles. In 2002/03 the survey was for older people, in 2003/04 it was for younger adults with physical and sensory impairments, and in 2004/05 it was for children. 2005/06 marked the beginning of the second wave of the cycle. The mandate for conducting surveys of user’s experiences and satisfaction with services was first given in the white paper Modern Local Government: in Touch with the People (Department for the Environment, Trade and the Regions, 1998). In 2002 the Office of National Statistics (ONS) and SPRU developed a set of questionnaires for this purpose (Qureshi and Rowlands, 2004). Subsequent national surveys have drawn on this work to identify a set of compulsory questions for each round. User experience surveys (UESs) are regarded as an important part of the overall performance framework for social care and, providing councils with information about how they might improve services locally. Local authorities are required to submit their results to government bodies so that the relative performance of the CSSRs can be judged. This report is composed of five sections. The aims and objectives of the report are outlined in the second section and the method used to gather the data is outlined in section 3. In section 4 we report on the findings from the fieldwork and draw some conclusions and recommendations for the national survey in section 5. The topic guides for the focus groups and interviews are included in the appendices along with a brief discussion of the findings from the focus groups and a copy of the final extended questionnaire.

628 citations