12 research outputs found

    Side lobe supression techniques for polyphase codes in radar

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    The present thesis aims to make an in-depth study of Radar pulse compression. Pulse compression (PC) is an important module in many of the modern radar systems. It is used to overcome major problem of a radar system that requires a long pulse to achieve large radiated energy but simultaneously a short pulse for range resolution .Range resolution is an ability of the receiver to detect nearby targets. The performance measures of PC techniques are PSL, ISL, SNR loss and Doppler shift. The major advantages of PC are resulting gain in SNR and relative tolerance to jammers. PC can also lift small target signals out of clutter. In this thesis we compare the merit factors of different sidelobe reduction techniques with a novel technique, using P4 code of length 1000. The amplitude weighting technique in which the code signal is multiplied with the window coefficients and the weighted code and the transmitted signal are applied to correlation in the receiver side .The tradeoff in reducing the PSL is spreading of the compressed pulse. Woo filter technique is that which uses two correlation filters to produce a single discrete filter, It reduces PSL and ISL at sacrifice of mainlobe splitting and 3 [dB] SNR loss. The modified forms of Woo filter reduce the PSL further and also the mainlobe splitting present in Woo filter is removed. Asymmetrical weighting is a technique in which amplitude of the Woo filter is taken as the weighting function to the incoming signal. This method enables to suppress PSL beyond Barker codes levels while other performance degradations are minimized. In the proposed technique amplitude weighting is applied to a combination of the incoming signal and one-bit shifted version of the incoming signal. This technique produces better peak side lobe ratio (PSL) and integrated side lobe ratio (ISL) than all other conventional sidelobe reduction techniques. Main lobe splitting which is the main disadvantage in Woo filter is eliminated in this techniques and it is easy to implement and incurs a minimal signal to noise ratio SNR loss

    Does ipsilateral remapping following hand loss impact motor control of the intact hand?

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    What happens once a cortical territory becomes functionally redundant? We studied how the brain and behaviour change for the remaining hand in humans (male and female) with either a missing hand from birth (one-handers) or due to amputation. Previous studies reported that in amputees, but not in one-handers, there is increased ipsilateral activity in the somatosensory territory of the missing hand (i.e., remapping). We used a complex finger task to explore whether this observed remapping in amputees involves recruiting more neural resources to support the intact hand to meet greater motor control demand. Using basic fMRI analysis, we found that only amputees had more ipsilateral activity when motor demand increased, however this did not match any noticeable improvement in their task performance. More advanced multivariate fMRI analysis showed that amputees had stronger and more typical representation – relative to controls’ contralateral hand representation – compared to one-handers. This suggests that in amputees, both hand areas work together more collaboratively, potentially reflecting the intact hand's efference copy. One-handers struggled to learn difficult finger configurations, but this did not translate to differences in univariate or multivariate activity relative to controls. Additional white matter analysis provided conclusive evidence that the structural connectivity between the two hand areas did not vary across groups. Together, our results suggest that enhanced activity in the missing hand territory may not reflect intact hand function. Instead, we suggest that plasticity is more restricted than generally assumed and may depend on the availability of homologous pathways acquired early in life

    A proposal for expansion of the medical specialty of rehabilitation medicine

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    The workforce of the medical specialty of Rehabilitation Medicine (RM) in the UK is 10 times less than the European average for the specialty of Physical and Rehabilitation Medicine (PRM). This can be explained partly by the difference in the scope of practice within the specialty between the UK and other European countries and USA. This opinion paper aims to compare the rehabilitation needs in chronic medical conditions and compare the scope of practice between countries within Europe and other regions of the world. The potential advantages of a broader remit specialty to improve rehabilitation care for patients by involving rehabilitation physicians in various medical conditions is explored. Recommendations have been put forward in the Rehabilitation Medicine Expansion Proposal (RMEP), which is likely to make the medical specialty of RM/ PRM more satisfying for the doctors working in the specialty and a more attractive career choice for those entering training in the specialty. There is a need for an international universal framework for the scope of the specialty to have a greater impact on improving the lives of those with chronic medical conditions

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Route optimization for mobile internet protocol

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    Includes bibliographical references (pages [60]-61).M.S. (Master of Science

    Critical Review on Physiological and Molecular Features during Bovine Mammary Gland Development: Recent Advances

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    The mammary gland is a unique organ with the ability to undergo repeated cyclic changes throughout the life of mammals. Among domesticated livestock species, ruminants (cattle and buffalo) constitute a distinct class of livestock species that are known milk producers. Cattle and buffalo contribute to 51 and 13% of the total milk supply in the world, respectively. They also play an essential role in the development of the economy for farming communities by providing milk, meat, and draft power. The development of the ruminant mammary gland is highly dynamic and multiphase in nature. There are six developmental stages: embryonic, prepubertal, pubertal, pregnancy, lactation, and involution. There has been substantial advancement in our understanding of the development of the mammary gland in both mouse and human models. Until now, there has not been a thorough investigation into the molecular processes that underlie the various stages of cow udder development. The current review sheds light on the morphological and molecular changes that occur during various developmental phases in diverse species, with a particular focus on the cow udder. It aims to explain the physiological differences between cattle and non-ruminant mammalian species such as humans, mice, and monkeys. Understanding the developmental biology of the mammary gland in molecular detail, as well as species-specific variations, will facilitate the researchers working in this area in further studies on cellular proliferation, differentiation, apoptosis, organogenesis, and carcinogenesis. Additionally, in-depth knowledge of the mammary gland will promote its use as a model organ for research work and promote enhanced milk yield in livestock animals without affecting their health and welfare

    Supplemental Material - Amputation of the Unsalvageable Leg in Vascular Patients with Cancer

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    Supplemental Material for Amputation of the Unsalvageable Leg in Vascular Patients with Cancer by Arsalan Wafi, Vijay Kolli, Bilal Azhar, Grace Poole, James Budge, Paul Moxey, Ian Loftus and Peter Holt in Vascular and Endovascular Surgery</p

    B-3-Tree: Byte-Addressable Binary B-Tree for Persistent Memory

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    In this work, we propose B-3-tree, a hybrid index for persistent memory that leverages the byte-addressability of the in-memory index and the page locality of B-trees. As in the byte-addressable in-memory index, B-3-tree is updated by 8-byte store instructions. Also, as in disk-based index, B-3-tree is failure-atomic since it makes every 8-byte store instruction transform a consistent index into another consistent index without the help of expensive logging. Since expensive logging becomes unnecessary, the number of cacheline flush instructions required for B-3-tree is significantly reduced. Our performance study shows that B-3-tree outperforms other state-of-the-art persistent indexes in terms of insert and delete performance. While B-3-tree shows slightly worse performance for point query performance, the range query performance of B-3-tree is 2x faster than FAST and FAIR B-tree because the leaf page size of B-3-tree can be set to 8x larger than that of FAST and FAIR B-tree without degrading insertion performance. We also show that read transactions can access B-3- tree without acquiring a shared lock because B-3-tree remains always consistent while a sequence of 8-byte write operations are making changes to it. As a result, B-3-tree provides high concurrency level comparable to FAST and FAIR B-tree
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