26 research outputs found

    Road vehicle state estimation using low-cost GPS/INS

    Get PDF
    Due to noise and bias in the Inertial Navigation System (INS), vehicle dynamics measurements using the INS are inaccurate. Although alternative methods involving the integration of INS with accurate Global Positioning System (GPS) exist and are accurate, this kind of system is far too expensive to become value-adding to production vehicles. This thesis therefore considers two aspects: 1) the possibility of estimating vehicle dynamics using low-cost INS and GPS, and 2) the importance of vehicle dynamics in terms of handling in the eyes of customers upon vehicle purchase. The former aspect is considered from an engineering perspective and the latter is studied in a marketing context. From an engineering point of view, knowledge of vehicle dynamics not only improves existing safety control systems, such the Anti-lock Braking System (ABS) and Electronic Stabilising Program (ESP), but also allows the development of new systems. Based on modelling and simulation in MATLAB/Simulink, low-cost GPS and in-car INS (such as accelerometers, gyroscopes and wheel speed sensors) measurements are fused using Kalman Filters (KFs) to estimate the vehicle dynamics. These estimations are then compared with the simulation results from IPG Car- Maker. For most simulations, the speed of the vehicle is kept between 15 to 55kph. It is found that while triple KF designs are able to estimate the tyre radius, the longitudinal velocity and the heading angle accurately, an integrated KF design with known vehicle parameters is also able to estimate the lateral velocity precisely. Apart from studying and comparing different KF designs with restricted sensors quality, the effects and benefits of different sensor qualities in dynamic estimations are also studied via the variation of sensor sampling rates and accuracies. This investigation produces a design procedure and estimation error analyses (theoretical and graphical) which may help future engineers in designing their KFs. From a marketing perspective, it is important to understand customers’ purchase reasons in order to allocate resources more efficiently and effectively. As GPS/INS KF designs are able to enhance vehicle handling, it is vital to understand the relative importance of vehicle handling as a consumer purchase choice criterion. Based on two surveys, namely the New Vehicle Experience Survey in the US (NVES US) and the New Car Buyer Survey in the UK (NCBS UK), analyses are performed in a computer program called the Predictive Analytics SoftWare (PASW), which is formerly known as the Statistical Package for the Social Sciences (SPSS). The number of purchase reasons are first reduced with factor analysis, the latent factors produced are then used in the SPSS Two Step Cluster analysis for customer segmentation. With the customer segments and the latent factors defined, a discriminant analysis is carried out to determine customer type in the automobile sector, in particular for Jaguar Cars. It is found that customers in general take vehicle handling for granted and often underrate its importance in their purchase. New vehicle handling-aided systems therefore need to be marketed in terms of the value they add to other benefits such as reliability and performance in order to increase sales and stakeholder value

    Long-term care cost drivers and expenditure projection to 2036 in Hong Kong

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Hong Kong's rapidly ageing population, characterised by one of the longest life expectancies and the lowest fertility rate in the world, is likely to drive long-term care (LTC) expenditure higher. This study aims to identify key cost drivers and derive quantitative estimates of Hong Kong's LTC expenditure to 2036.</p> <p>Methods</p> <p>We parameterised a macro actuarial simulation with data from official demographic projections, Thematic Household Survey 2004, Hong Kong's Domestic Health Accounts and other routine data from relevant government departments, Hospital Authority and other LTC service providers. Base case results were tested against a wide range of sensitivity assumptions.</p> <p>Results</p> <p>Total projected LTC expenditure as a proportion of GDP reflected secular trends in the elderly dependency ratio, showing a shallow dip between 2004 and 2011, but thereafter yielding a monotonic rise to reach 3.0% by 2036. Demographic changes would have a larger impact than changes in unit costs on overall spending. Different sensitivity scenarios resulted in a wide range of spending estimates from 2.2% to 4.9% of GDP. The availability of informal care and the setting of formal care as well as associated unit costs were important drivers of expenditure.</p> <p>Conclusion</p> <p>The "demographic window" between the present and 2011 is critical in developing policies to cope with the anticipated burgeoning LTC burden, in concert with the related issues of health care financing and retirement planning.</p

    A reference-grade wild soybean genome

    Get PDF
    Wild relatives of crop plants are invaluable germplasm for genetic improvement. Here, Xie et al. report a reference-grade wild soybean genome and show that it can be used to identify structural variation and refine quantitative trait loci

    A reference-grade wild soybean genome

    Get PDF
    Efficient crop improvement depends on the application of accurate genetic information contained in diverse germplasm resources. Here we report a reference-grade genome of wild soybean accession W05, with a final assembled genome size of 1013.2 Mb and a contig N50 of 3.3 Mb. The analytical power of the W05 genome is demonstrated by several examples. First, we identify an inversion at the locus determining seed coat color during domestication. Second, a translocation event between chromosomes 11 and 13 of some genotypes is shown to interfere with the assignment of QTLs. Third, we find a region containing copy number variations of the Kunitz trypsin inhibitor (KTI) genes. Such findings illustrate the power of this assembly in the analysis of large structural variations in soybean germplasm collections. The wild soybean genome assembly has wide applications in comparative genomic and evolutionary studies, as well as in crop breeding and improvement programs

    Neurodegeneration of the retina in mouse models of Alzheimer’s disease: what can we learn from the retina?

    Get PDF
    Alzheimer’s disease (AD) is an age-related progressive neurodegenerative disease commonly found among elderly. In addition to cognitive and behavioral deficits, vision abnormalities are prevalent in AD patients. Recent studies investigating retinal changes in AD double-transgenic mice have shown altered processing of amyloid precursor protein and accumulation of β-amyloid peptides in neurons of retinal ganglion cell layer (RGCL) and inner nuclear layer (INL). Apoptotic cells were also detected in the RGCL. Thus, the pathophysiological changes of retinas in AD patients are possibly resembled by AD transgenic models. The retina is a simple model of the brain in the sense that some pathological changes and therapeutic strategies from the retina may be observed or applicable to the brain. Furthermore, it is also possible to advance our understanding of pathological mechanisms in other retinal degenerative diseases. Therefore, studying AD-related retinal degeneration is a promising way for the investigation on (1) AD pathologies and therapies that would eventually benefit the brain and (2) cellular mechanisms in other retinal degenerations such as glaucoma and age-related macular degeneration. This review will highlight the efforts on retinal degenerative research using AD transgenic mouse models

    New insights into the genetic etiology of Alzheimer's disease and related dementias

    Get PDF
    Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

    Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

    Get PDF
    Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p&lt;0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p&lt;0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

    Breast cancer management pathways during the COVID-19 pandemic: outcomes from the UK ‘Alert Level 4’ phase of the B-MaP-C study

    Get PDF
    Abstract: Background: The B-MaP-C study aimed to determine alterations to breast cancer (BC) management during the peak transmission period of the UK COVID-19 pandemic and the potential impact of these treatment decisions. Methods: This was a national cohort study of patients with early BC undergoing multidisciplinary team (MDT)-guided treatment recommendations during the pandemic, designated ‘standard’ or ‘COVID-altered’, in the preoperative, operative and post-operative setting. Findings: Of 3776 patients (from 64 UK units) in the study, 2246 (59%) had ‘COVID-altered’ management. ‘Bridging’ endocrine therapy was used (n = 951) where theatre capacity was reduced. There was increasing access to COVID-19 low-risk theatres during the study period (59%). In line with national guidance, immediate breast reconstruction was avoided (n = 299). Where adjuvant chemotherapy was omitted (n = 81), the median benefit was only 3% (IQR 2–9%) using ‘NHS Predict’. There was the rapid adoption of new evidence-based hypofractionated radiotherapy (n = 781, from 46 units). Only 14 patients (1%) tested positive for SARS-CoV-2 during their treatment journey. Conclusions: The majority of ‘COVID-altered’ management decisions were largely in line with pre-COVID evidence-based guidelines, implying that breast cancer survival outcomes are unlikely to be negatively impacted by the pandemic. However, in this study, the potential impact of delays to BC presentation or diagnosis remains unknown

    Road vehicle state estimation using low-cost GPS/INS

    Get PDF
    Assuming known vehicle parameters, this paper proposes an innovative integrated Kalman filter (IKF) scheme to estimate vehicle dynamics, in particular the sideslip, the heading and the longitudinal velocity. The IKF is compared with the 2DoF linear bicycle model, the triple Kalman filter (KF) and a model-based KF (MKF) in a simulation environment. Simulation results show that the proposed IKF is superior to other KF designs (both Kinematic KF and MKF) on state estimation when tyre characteristics are within the linear region (i.e. manoeuvres below 55 kph)

    Road vehicle state estimation using low-cost GPS/INS

    No full text
    Due to noise and bias in the Inertial Navigation System (INS), vehicle dynamics measurements using the INS are inaccurate. Although alternative methods involving the integration of INS with accurate Global Positioning System (GPS) exist and are accurate, this kind of system is far too expensive to become value-adding to production vehicles. This thesis therefore considers two aspects: 1) the possibility of estimating vehicle dynamics using low-cost INS and GPS, and 2) the importance of vehicle dynamics in terms of handling in the eyes of customers upon vehicle purchase. The former aspect is considered from an engineering perspective and the latter is studied in a marketing context. From an engineering point of view, knowledge of vehicle dynamics not only improves existing safety control systems, such the Anti-lock Braking System (ABS) and Electronic Stabilising Program (ESP), but also allows the development of new systems. Based on modelling and simulation in MATLAB/Simulink, low-cost GPS and in-car INS (such as accelerometers, gyroscopes and wheel speed sensors) measurements are fused using Kalman Filters (KFs) to estimate the vehicle dynamics. These estimations are then compared with the simulation results from IPG Car- Maker. For most simulations, the speed of the vehicle is kept between 15 to 55kph. It is found that while triple KF designs are able to estimate the tyre radius, the longitudinal velocity and the heading angle accurately, an integrated KF design with known vehicle parameters is also able to estimate the lateral velocity precisely. Apart from studying and comparing different KF designs with restricted sensors quality, the effects and benefits of different sensor qualities in dynamic estimations are also studied via the variation of sensor sampling rates and accuracies. This investigation produces a design procedure and estimation error analyses (theoretical and graphical) which may help future engineers in designing their KFs. From a marketing perspective, it is important to understand customers’ purchase reasons in order to allocate resources more efficiently and effectively. As GPS/INS KF designs are able to enhance vehicle handling, it is vital to understand the relative importance of vehicle handling as a consumer purchase choice criterion. Based on two surveys, namely the New Vehicle Experience Survey in the US (NVES US) and the New Car Buyer Survey in the UK (NCBS UK), analyses are performed in a computer program called the Predictive Analytics SoftWare (PASW), which is formerly known as the Statistical Package for the Social Sciences (SPSS). The number of purchase reasons are first reduced with factor analysis, the latent factors produced are then used in the SPSS Two Step Cluster analysis for customer segmentation. With the customer segments and the latent factors defined, a discriminant analysis is carried out to determine customer type in the automobile sector, in particular for Jaguar Cars. It is found that customers in general take vehicle handling for granted and often underrate its importance in their purchase. New vehicle handling-aided systems therefore need to be marketed in terms of the value they add to other benefits such as reliability and performance in order to increase sales and stakeholder value.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
    corecore