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Optimization of log-periodic dipole antenna with LTE band rejection
Full text linkThis study presents an optimized design of a 10-dipole logperiodic antenna for UHF TV reception with LTE band rejection. The simulation of the antenna was performed in CST simulation software followed by optimization of the design using TRF (Trusted Region Framework) algorithm in the frequency range of 450 MHz-900 MHz. The parameters optimized are S11, realized gain and front-to-back ratio of the antenna. TV reception passband is 450 MHz-790 MHz and LTE band is 810 MHz-900 MHz. The proposed antenna design provides a good matching with a low S11 in the passband (470 MHz-790 MHz) and a high S11 in the stopband (i.e. LTE region of 810 MHz-900 MHz). The antenna provides a realized gain between 7 dBi and 8 dBi whereas front-to back ratio above 14 dB in the passband
Performance analysis and evaluation of direct phase measuring deflectometry
Full text linkThree-dimensional (3D) shape measurement of specular objects plays an important role in intelligent manufactur- ing applications. Phase measuring deflectometry (PMD)-based methods are widely used to obtain the 3D shapes of specular surfaces because they offer the advantages of a large dynamic range, high measurement accuracy, full-field and noncontact operation, and automatic data processing. To enable measurement of specular objects with discontinuous and/or isolated surfaces, a direct PMD (DPMD) method has been developed to build a direct relationship between phase and depth. In this paper, a new virtual measurement system is presented and is used to optimize the system parameters and evaluate the system’s performance in DPMD applications. Four system parameters are analyzed to obtain accurate measurement results. Experiments are performed using simulated and actual data and the results confirm the effects of these four parameters on the measurement results. Researchers can therefore select suitable system parameters for actual DPMD (including PMD) measurement systems to obtain the 3D shapes of specular objects with high accuracy
Relapse and Recurrence of Common Mental Health Problems after Low Intensity CBT: The WYLOW Longitudinal Cohort Study
Full text linkComparison of Metal-on-Metal Hip Simulator Wear Measured by Gravimetric, CMM and Optical Profiling Methods
Full text linkSimulation of wear in artificial joint implants is critical for evaluating implant designs and materials. Traditional protocols employ the gravimetric method to determine the loss of material by measuring the weight of the implant components before and after various test intervals and after the completed test. However, the gravimetric method cannot identify the location, area coverage or maximum depth of the wear and it has difficulties with proportionally small weight changes in relatively heavy implants. In this study, we compare the gravimetric method with two geometric surface methods; an optical light method (RedLux) and a coordinate measuring method (CMM). We tested ten Adept hips in a simulator for 2 million cycles (MC). Gravimetric and optical methods were performed at 0.33, 0.66, 1.00, 1.33 and 2 MC. CMM measurements were done before and after the test. A high correlation was found between the gravimetric and optical methods for both heads (R<sup>2</sup> = 0.997) and for cups (R<sup>2</sup> = 0.96). Both geometric methods (optical and CMM) measured more volume loss than the gravimetric method (for the heads, p = 0.004 (optical) and p = 0.08 (CMM); for the cups p = 0.01 (optical) and p = 0.003 (CMM)). Two cups recorded negative wear at 2 MC by the gravimetric method but none did by either the optical method or by CMM. The geometric methods were prone to confounding factors such as surface deformation and the gravimetric method could be confounded by protein absorption and backside wear. Both of the geometric methods were able to show the location, area covered and depth of the wear on the bearing surfaces, and track their changes during the test run; providing significant advantages to solely using the gravimetric method
Sustained Bauxite Residue Rehabilitation with Gypsum and Organic Matter 16 years after Initial Treatment
Full text linkBauxite residue is a high volume byproduct of alumina manufacture which is commonly disposed of in purpose-built bauxite residue disposal areas (BRDAs). Natural waters interacting with bauxite residue are characteristically highly alkaline, and have elevated concentrations of Na, Al, and other trace metals. Rehabilitation of BRDAs is therefore often costly and resource/infrastructure intensive. Data is presented from three neighboring plots of bauxite residue that was deposited 20 years ago. One plot was amended 16 years ago with process sand, organic matter, gypsum, and seeded (fully treated), another plot was amended 16 years ago with process sand, organic matter, and seeded (partially treated), and a third plot was left untreated. These surface treatments lower alkalinity and salinity, and thus produce a substrate more suitable for biological colonisation from seeding. The reduction of pH leads to much lower Al, V, and As mobility in the actively treated residue and the beneficial effects of treatment extend passively 20–30 cm below the depth of the original amendment. These positive rehabilitation effects are maintained after 2 decades due to the presence of an active and resilient biological community. This treatment may provide a lower cost solution to BRDA end of use closure plans and orphaned BRDA rehabilitation
A Learning Based Framework for Improving Querying on Web Interfaces of Curated Knowledge Bases
Full text linkKnowledge Bases (KBs) are widely used as one of the fundamental components in Semantic Web applications as they provide facts and relationships that can be automatically understood by machines. Curated knowledge bases usually use Resource Description Framework (RDF) as the data representation model. To query the RDF-presented knowledge in curated KBs, Web interfaces are built via SPARQL Endpoints. Currently, querying SPARQL Endpoints has problems like network instability and latency, which affect the query efficiency. To address these issues, we propose a client-side caching framework, SPARQL Endpoint Caching Framework (SECF), aiming at accelerating the overall querying speed over SPARQL Endpoints. SECF identifies the potential issued queries by leveraging the querying patterns learned from clients’ historical queries and prefecthes/caches these queries. In particular, we develop a distance function based on graph edit distance to measure the similarity of SPARQL queries. We propose a feature modelling method to transform SPARQL queries to vector representation that are fed into machine-learning algorithms. A time-aware smoothing-based method, Modified Simple Exponential Smoothing (MSES), is developed for cache replacement. Extensive experiments performed on real-world queries showcase the effectiveness of our approach, which outperforms the state-of-the-art work in terms of the overall querying speed
The virtual simulation of child sexual abuse: Online gameworld users’ views, understanding and responses to sexual ageplay.
Full text linkThis paper explores cultural understandings of virtual sexual ageplay in the online world of Second Life. Online sexual ageplay is the virtual simulation of child abuse by consensual adults operating in-world with child computer characters (avatars). Second Life is primarily governed by Community Standards which rely on residents (the users of Second Life) to recognise sexual ageplay and report it, which requires an appreciation of how residents view, understand and construct sexual ageplay. The research presented drew on 12 months of resident blog posts referring to sexual ageplay: 263 total, with 91 residents. The analysis of this talk explores the cultural understandings of this banned behaviour and beliefs about the nature of Second Life which underpin residents’ likelihood to report sexual ageplay and so comply with the Community Standards. In considering these issues the paper is able to highlight issues regarding the unique cultural position of abuse against children and key concerns which underpin the reporting behaviour of residents. Key considerations relate to defining online sexual activity, child avatars; the moral status of ‘reporters’, and sexual ageplay as a form of edgeplay; belief in the harmfulness of sexual ageplay and its relationship to real world behaviours
Pedagogical Implications for Using a Wiki in Peer-to-Peer Learning Environments
Full text linkThe pedagogical potentials and challenges experienced when trying to incorporate the use of a wiki social media site with undergraduate childhood study students are reported. The wiki was introduced to inspire students to engage in student peer-learning, develop their writing skills, and facilitate a PhD student’s developmental teaching beyond the dissertation phase from PhD student to scholar. Although these aims were achieved to a degree, they were reached in unexpected ways. A “community of practice” (Lave & Wenger, 1991) was evident within the actual seminar session space rather than within an online community capacity
What factors can affect the management of diabetes with regard to studying at university? A systematic review
Full text linkThe purpose of this review is to identify and synthesise literature about diabetes management, and specifically, the barriers that may affect university students’ Type 2 diabetes management. A systematic literature search was conducted using five databases: CINAHL, Google Scholar, PsychINFO, PubMed and Summon. Eligible articles from January 2010 to February 2017 were included in the review. Articles identified by the search which met the inclusion criteria were screened prior to selection for synthesis. A total of 2,577 articles were screened, of which 72 were fully assessed for synthesis. Of these, 22 met the inclusion criteria as they provided useful insights into the issue and were deemed relevant to enable the research question to be answered. These were included in the review.
This review found that individual and external characteristics play a significant role in diabetes management. Additionally, external stressors from university can lead to patients’ non-adherence to medication regimens. The comprehensive review of the evidence in the current body of literature illustrates that a range of factors may affect university students’ management of their Type 2 diabetes. Thus, it provides information that may inform how university well-being teams and policymakers support university students with Type 2 diabetes. Despite attempts being made to undertake a comprehensive search, certain aspects restricted this, such as there being only a single researcher. Nevertheless, this review is important as it identifies a gap in knowledge about Type 2 diabetes management among the university student population. Importantly, this research found that there is a need for more empirical work to be undertaken within the university population to examine external stressors that may affect students’ diabetes management
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