302 research outputs found

    Development of modified double-weight code and its implementation in multi-rate transmissions

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    This paper presents a new code structure and its ability in supporting multiple transmission rates in point to point Spectral Amplitude Coding- Optical Code Division Multiple Access (SAC-OCDMA) links. The Double-Weight (DW) code family that has a basic fixed weight of 2 was proposed. Modified Double Weight (MDW) Code is a DW code family variation that has variable weight of greater than two. The ability of MDW codes to support simultaneous transmissions at different bit rates is shown through simulated results of the bit error rate (BER) and the eye patterns. Four MDW encoded channels were used at the bit rates of 2.5Gbps and 10Gbps. MDW code shown here significantly performs better than Hadamard and Modified Frequency Hopping (MFH) codes

    Design & investigation of 10x10 gbit/s MDM over hybrid FSO link under different weather conditions and fiber to the home

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    In this paper, we design and investigate 10-channels of mode division multiplexer (MDM) over hybrid free-space optics (FSO) link in several weather conditions to achieve the maximum possible medium range and fiber to the home (FTTH) for high bandwidth access networks. System capacity can be effectively increased with the use of MDM over hybrid FSO-FTTH. In this study, a 10-channel MDM over FSO-FTTH system has been analyzed in different weather conditions that operate at 1550 nm wavelength. The simulated system has transmitted 100 Gbit/s up for a distance of 3200 meters FSO in superbly clear weather condition. It also transmitted 100 Gbit/s up for a distance of 650 meters FSO during heavy rain. The validation of this study is measures based on eye diagrams bit-error rates (BER) that have been analyzed

    Hybrid WDM/OCDMA system to support differentiated services in access network

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    This paper presents a new scheme of WDM/OCDMA system that capable of providing differentiated services in access network. We implement the proposed double-weight (DW) code in this system. The double-weight (DW) code has a fixed weight of 2 and exists for every natural number, n. In spectral-amplitude-coding optical code division multiple access (CDMA) systems, DW code has an ideal cross correlation to eliminate multiuser interference and suppress the noise. We analyze the performance of the system by evaluating the bit error rate (BER) of different services

    Performance comparison of complementary and AND subtraction detection techniques for hybrid SCM SAC-OCDMA system

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    The subtraction detection techniques for a hybrid SCM spectral-amplitude-coding (SAC) OCDMA using double weight (DW) code family are investigated. The experimental simulation results show that the proposed new subtraction detection technique provides a better system performance

    Optical domain service differentiation using spectral-amplitude-coding

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    We have implemented a new service differentiation technique in the optical domain using a spectral-amplitude-coding (SAC) variant of optical code division multiple access (OCDMA). The newly developed code, named KS (Khazani–Syed) is compared mathematically with other codes which use similar techniques. In our proposal, multiple weights are used to support ‘triple-play’ services (audio, video and data) with different quality-of-service (QoS) requirements. The results characterizing the bit-error-rate (BER) with respect to the total number of active users show that KS offers a significantly improved performance over the previous reported techniques by accommodating additional 30 users with shorter code length and smaller code weight at BER of 10−9. In variable weight system, we have shown that KS codes with larger weight always have the best performance when other users of different weights are present in the system

    Mortality, morbidity, and hospitalisations due to influenza lower respiratory tract infections, 2017: an analysis for the global burden of disease study 2017

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    Although the burden of influenza is often discussed in the context of historical pandemics and the threat of future pandemics, every year a substantial burden of lower respiratory tract infections (LRTIs) and other respiratory conditions (like chronic obstructive pulmonary disease) are attributable to seasonal influenza. The Global Burden of Disease Study (GBD) 2017 is a systematic scientific effort to quantify the health loss associated with a comprehensive set of diseases and disabilities. In this Article, we focus on LRTIs that can be attributed to influenza. Methods: We modelled the LRTI incidence, hospitalisations, and mortality attributable to influenza for every country and selected subnational locations by age and year from 1990 to 2017 as part of GBD 2017. We used a counterfactual approach that first estimated the LRTI incidence, hospitalisations, and mortality and then attributed a fraction of those outcomes to influenza. Findings: Influenza LRTI was responsible for an estimated 145 000 (95% uncertainty interval [UI] 99 000–200 000) deaths among all ages in 2017. The influenza LRTI mortality rate was highest among adults older than 70 years (16·4 deaths per 100 000 [95% UI 11·6–21·9]), and the highest rate among all ages was in eastern Europe (5·2 per 100 000 population [95% UI 3·5–7·2]). We estimated that influenza LRTIs accounted for 9 459 000 (95% UI 3 709 000–22 935 000) hospitalisations due to LRTIs and 81 536 000 hospital days (24 330 000–259 851 000). We estimated that 11·5% (95% UI 10·0–12·9) of LRTI episodes were attributable to influenza, corresponding to 54 481 000 (38 465 000–73 864 000) episodes and 8 172 000 severe episodes (5 000 000–13 296 000). Interpretation: This comprehensive assessment of the burden of influenza LRTIs shows the substantial annual effect of influenza on global health. Although preparedness planning will be important for potential pandemics, health loss due to seasonal influenza LRTIs should not be overlooked, and vaccine use should be considered. Efforts to improve influenza prevention measures are needed. Funding: Bill & Melinda Gates Foundation

    Development of clinical pathway for mild cognitive impairment and dementia to quantify cost of age-related cognitive disorders in Malaysia

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    As the Malaysian population ages, the burden of age-related cognitive disorders such as dementia and Alzheimer’s disease will increase concomitantly. This is one of the sub-study under a research project titled by quantify the cost of age-related cognitive impairment in Malaysia, which was undertaken to develop a clinical pathway for Mild Cognitive Impairment (MCI) and Dementia. The clinical pathway (CP) will be used to support the costing studies of MCI and Dementia. An expert group discussion (EGD) was conducted among selected experts from six (6) government hospitals from different states of Malaysia, Ministry of Health, and United Nations University, International Institute for Global Health, UKM and UPM. The expert group includes psychiatrist specialists and public health medicine specialists. A total of 15 participants took part in the EGD. The group was presented with the different approach in managing MCI and Dementia. Finally, the group came to the consensus agreement on the most appropriate and efficient ways of managing the two conditions. In the EGD, an operational definition for MCI and Dementia was agreed upon and a pathway was developed for the usual practice in the Malaysian health system. A typical case used, as a reference is a 60-year-old patient referred to a memory clinic with complaint of “forgetfulness”. After three outpatient visits in the clinic, the diagnosis of MCI and Dementia could be clinically established. The clinical pathways covered all active clinical and non-clinical management of the patient over a period of one year. The experts identified the additional resources required to manage these patients for the whole spectrum of lifetime based on the expected life expectancy. The Clinical pathway (CP) for MCI and Dementia was successfully developed in EGD with strong support from practitioners in the health system. The findings will help the researchers to identify all-important clinical activities and interventions that will be included in the costing study

    Impact of routine PCV7 (Prevenar) vaccination of infants on the clinical and economic burden of pneumococcal disease in Malaysia

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    <p>Abstract</p> <p>Background</p> <p>Pneumococcal disease is the leading cause of vaccine-preventable death in children younger than 5 years of age worldwide. The World Health Organization recommends pneumococcal conjugate vaccine as a priority for inclusion into national childhood immunization programmes. Pneumococcal vaccine has yet to be included as part of the national vaccination programme in Malaysia although it has been available in the country since 2005. This study sought to estimate the disease burden of pneumococcal disease in Malaysia and to assess the cost effectiveness of routine infant vaccination with PCV7.</p> <p>Methods</p> <p>A decision model was adapted taking into consideration prevalence, disease burden, treatment costs and outcomes for pneumococcal disease severe enough to result in a hospital admission. Disease burden were estimated from the medical records of 6 hospitals. Where local data was unavailable, model inputs were obtained from international and regional studies and from focus group discussions. The model incorporated the effects of herd protection on the unvaccinated adult population.</p> <p>Results</p> <p>At current vaccine prices, PCV7 vaccination of 90% of a hypothetical 550,000 birth cohort would incur costs of RM 439.6 million (US128million).Overa10yeartimehorizon,vaccinationwouldreduceepisodesofpneumococcalhospitalisationby9,585casesto73,845hospitalisationswithcostsavingsofRM37.5million(US128 million). Over a 10 year time horizon, vaccination would reduce episodes of pneumococcal hospitalisation by 9,585 cases to 73,845 hospitalisations with cost savings of RM 37.5 million (US10.9 million) to the health system with 11,422.5 life years saved at a cost effectiveness ratio of RM 35,196 (US10,261)perlifeyeargained.</p><p>Conclusions</p><p>PCV7vaccinationofinfantsisexpectedtobecosteffectiveforMalaysiawithanincrementalcostperlifeyeargainedofRM35,196(US10,261) per life year gained.</p> <p>Conclusions</p> <p>PCV7 vaccination of infants is expected to be cost-effective for Malaysia with an incremental cost per life year gained of RM 35,196 (US10,261). This is well below the WHO's threshold for cost effectiveness of public health interventions in Malaysia of RM 71,761 (US$20,922).</p

    Global, regional, and national burden of respiratory tract cancers and associated risk factors from 1990 to 2019: a systematic analysis for the Global Burden of Disease Study 2019

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    Background Prevention, control, and treatment of respiratory tract cancers are important steps towards achieving target 3.4 of the UN Sustainable Development Goals (SDGs)—a one-third reduction in premature mortality due to non-communicable diseases by 2030. We aimed to provide global, regional, and national estimates of the burden of tracheal, bronchus, and lung cancer and larynx cancer and their attributable risks from 1990 to 2019. Methods Based on the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 methodology, we evaluated the incidence, mortality, years lived with disability, years of life lost, and disability-adjusted life-years (DALYs) of respiratory tract cancers (ie, tracheal, bronchus, and lung cancer and larynx cancer). Deaths from tracheal, bronchus, and lung cancer and larynx cancer attributable to each risk factor were estimated on the basis of risk exposure, relative risks, and the theoretical minimum risk exposure level input from 204 countries and territories, stratified by sex and Socio-demographic Index (SDI). Trends were estimated from 1990 to 2019, with an emphasis on the 2010–19 period. Findings Globally, there were 2·26 million (95% uncertainty interval 2·07 to 2·45) new cases of tracheal, bronchus, and lung cancer, and 2·04 million (1·88 to 2·19) deaths and 45·9 million (42·3 to 49·3) DALYs due to tracheal, bronchus, and lung cancer in 2019. There were 209 000 (194 000 to 225 000) new cases of larynx cancer, and 123 000 (115 000 to 133 000) deaths and 3·26 million (3·03 to 3·51) DALYs due to larynx cancer globally in 2019. From 2010 to 2019, the number of new tracheal, bronchus, and lung cancer cases increased by 23·3% (12·9 to 33·6) globally and the number of larynx cancer cases increased by 24·7% (16·0 to 34·1) globally. Global age-standardised incidence rates of tracheal, bronchus, and lung cancer decreased by 7·4% (−16·8 to 1·6) and age-standardised incidence rates of larynx cancer decreased by 3·0% (−10·5 to 5·0) in males over the past decade; however, during the same period, age-standardised incidence rates in females increased by 0·9% (−8·2 to 10·2) for tracheal, bronchus, and lung cancer and decreased by 0·5% (−8·4 to 8·1) for larynx cancer. Furthermore, although age-standardised incidence and death rates declined in both sexes combined from 2010 to 2019 at the global level for tracheal, bronchus, lung and larynx cancers, some locations had rising rates, particularly those on the lower end of the SDI range. Smoking contributed to an estimated 64·2% (61·9–66·4) of all deaths from tracheal, bronchus, and lung cancer and 63·4% (56·3–69·3) of all deaths from larynx cancer in 2019. For males and for both sexes combined, smoking was the leading specific risk factor for age-standardised deaths from tracheal, bronchus, and lung cancer per 100 000 in all SDI quintiles and GBD regions in 2019. However, among females, household air pollution from solid fuels was the leading specific risk factor in the low SDI quintile and in three GBD regions (central, eastern, and western sub-Saharan Africa) in 2019. Interpretation The numbers of incident cases and deaths from tracheal, bronchus, and lung cancer and larynx cancer increased globally during the past decade. Even more concerning, age-standardised incidence and death rates due to tracheal, bronchus, lung cancer and larynx cancer increased in some populations—namely, in the lower SDI quintiles and among females. Preventive measures such as smoking control interventions, air quality management programmes focused on major air pollution sources, and widespread access to clean energy should be prioritised in these settings.publishedVersio
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