33 research outputs found

    Instrumentation for Ferromagnetic Resonance Spectrometer

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    Diminishing Signaling Traffic for Authentication in Mobile Communication System

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    To identify a mobile station (MS) and validate legal service requests, authentication functions are utilized in the location registration, call origination and call termination procedures. In GSM, the VLR requests the HLR for assistance in authenticating the visiting user. The authentication center (AuC) in the home network generates 3-tuples and sends them back to the VLR for subsequent authentications during the user’s residence. If these 3-tuples are used up before the MS’s leaving, another request is issued by the VLR. The request is expensive, because it needs to access the HLR/AuC. Traditionally, a fixed-K strategy is used. That is, K 3-tuples are sent to the VLR for each request. Lager K is preferred to reduce the number of the expensive requests for 3-tuples. However, much waste of 3-tuples is observed, especially when an inactive user is considered. Hence, K value should be determined based on the usage pattern of the user. We propose a dynamic-K (DK) strategy to reduce the waste and diminish the signaling traffic for authentication. Simulation results show that the DK strategy can effectively determine the appropriate K value. Not only the waste but also the number of requests are diminished efficiently

    Association of Genetic Variants Related to Combined Exposure to Higher Body Mass Index and Waist-to-Hip Ratio on Lifelong Cardiovascular Risk in UK Biobank

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    OBJECTIVE: This study examines the individual and combined association of body mass index (BMI) and 7 waist-to-hip ratio (WHR) with cardiovascular diseases (CVD) risk using genetic scores of the 8 obesity measurements as proxies. DESIGN: A 2×2 factorial analysis approach was applied, with participants divided into four groups of lifetime exposure to low BMI and WHR, high BMI, high WHR, and high BMI and WHR based on weighted genetic risk scores. The difference in CVD risk across groups was evaluated using multivariable logistic regression. SETTING: Cohort study. PARTICIPANTS: A total of 408,003 participants were included from the prospective observational UK Biobank study. RESULTS: A total of 58,429 of CVD events were recorded. Compared to the low BMI and WHR genetic scores group, higher BMI or higher WHR genetic scores were associated with an increase in CVD risk (high BMI: odds ratio (OR), 1.07; 95%CI, 1.04-1.10; high WHR: OR, 1.12; 95%CI, 1.09-1.16). A weak additive effect on CVD risk was found between BMI and WHR (high BMI and WHR: OR, 1.16; 95%CI, 1.12-1.19). Subgroup analysis showed similar patterns between different sex, age (<65, ≥65 years old), smoking status, Townsend deprivation index, fasting glucose level and medication uses, but lower systolic blood pressure was associated with higher CVD risk in obese participants. CONCLUSIONS: High BMI or WHR were associated with increased CVD risk, and their effects are weakly additive. Even though there were overlapping of effect, both BMI and WHR are important in assessing the CVD risk in the general population

    Age-Specific Associations of Usual Blood Pressure Variability With Cardiovascular Disease and Mortality: 10-Year Diabetes Mellitus Cohort Study.

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    Background The detrimental effects of increased variability in systolic blood pressure (SBP) on cardiovascular disease (CVD) and mortality risk in patients with diabetes mellitus remains unclear. This study evaluated age-specific association of usual SBP visit-to-visit variability with CVD and mortality in patients with type 2 diabetes mellitus. Methods and Results A retrospective cohort study investigated 155 982 patients with diabetes mellitus aged 45 to 84 years without CVD at baseline (2008-2010). Usual SBP variability was estimated using SBP SD obtained from a mixed-effects model. Age-specific associations (45-54, 55-64, 65-74, 75-84 years) between usual SBP variability, CVD, and mortality risk were assessed by Cox regression adjusted for patient characteristics. After a median follow-up of 9.7 years, 49 816 events (including 34 039 CVD events and 29 211 mortalities) were identified. Elevated SBP variability was independently, positively, and log-linearly associated with higher CVD and mortality risk among all age groups, with no evidence of any threshold effects. The excess CVD and mortality risk per 5 mm Hg increase in SBP variability within the 45 to 54 age group is >3 times higher than the 70 to 79 age group (hazard ratio, 1.66; 95% CI, 1.49-1.85 versus hazard ratio, 1.19; 95% CI, 1.15-1.23). The significant associations remained consistent among all subgroups. Patients with younger age had a higher association of SBP variability with event outcomes. Conclusions The findings suggest that SBP visit-to-visit variability was strongly associated with CVD and mortality with no evidence of a threshold effect in a population with diabetes mellitus. As well as controlling overall blood pressure levels, SBP visit-to-visit variability should be monitored and evaluated in routine practice, in particular for younger patients

    Impedance of nanometer thickness ferromagnetic Co40Fe40B20 films

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    Nanocrystalline Co40Fe40B20 films, with film thickness tf = 100 nm, were deposited on glass substrates by the magnetron sputtering method at room temperature. During the film deposition period, a dc magnetic field, h = 40 Oe, was applied to introduce an easy axis for each film sample: one with h||L and the other with h||w, where L and w are the length and width of the film. Ferromagnetic resonance (FMR), ultrahigh frequency impedance (IM), dc electrical resistivity (ρ), and magnetic hysteresis loops (MHL) of these films were studied. From the MHL and r measurements, we obtain saturation magnetization 4πMs = 15.5 kG, anisotropy field Hk = 0.031 kG, and r = 168 mW.cm. From FMR, we can determine the Kittel mode ferromagnetic resonance (FMR-K) frequency fFMRK = 1,963 MHz. In the h||L case, IM spectra show the quasi-Kittel-mode ferromagnetic resonance (QFMR-K) at f0 and the Walker-mode ferromagnetic resonance (FMR-W) at fn, where n = 1, 2, 3, and 4. In the h||w case, IM spectra show QFMR-K at F0 and FMR-W at Fn. We find that f0 and F0 are shifted from fFMRK, respectively, and fn = Fn. The in-plane spin-wave resonances are responsible for those relative shifts

    Age-specific Multimorbidity Patterns and Burden on All-Cause Mortality and Public Direct Medical Expenditure:A Retrospective Cohort Study

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    Objective To evaluate age-specific multimorbidity patterns and morbidity burden on mortality and healthcare expenditure across age groups. Patients and Methods Retrospective observational study between January 1, 2009 to December 31, 2017 using electronic health records in Hong Kong: Individuals were stratified by age (< 50, 50–64, 65–79, ≥ 80), and sub-classified by number of morbidities (0, 1, 2, 3, ≥ 4) out of 21 common chronic conditions. Clustering analyses were conducted to identify specific patterns of multimorbidity. Association between the number as well as combinations of morbidities and all-cause mortality and public expenditure was examined. Results 4,562,832 individuals with a median follow-up of 7 years were included. Mental disorders were the top morbidities among young individuals, while cardiovascular diseases were prevalent in the elderly. An increased number of morbidities was associated with a greater relative risk for mortality and medical expenditure, and this relationship was stronger among younger patients. Compared to individuals in the same age group without morbidity, the hazard ratios (HR; 95% CI) of all-cause mortality in patients aged < 50 and ≥ 80 with two comorbidities 3.81 (3.60–4.03) and 1.38 (1.36–1.40), respectively, which increased to 14.22 (9.87–20.47) and 2.20 (2.13–2.26), respectively, as the number of morbidities increased to ≥ 4. The stroke-hypertension cluster was shown to be associated with the highest HR of mortality 2.48 (2.43–2.53) among all identified clusters arising from the clustering analysis. Conclusion Given the stronger association between multimorbidity and all-cause mortality and greater opportunity costs in younger populations, prevention and management of early-onset multimorbidity are warranted. (248 words

    The Spill-Over Impact of the Novel Coronavirus-19 Pandemic on Medical Care and Disease Outcomes in Non-communicable Diseases: A Narrative Review

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    OBJECTIVES: The coronavirus-19 (COVID-19) pandemic has claimed more than 5 million lives worldwide by November 2021. Implementation of lockdown measures, reallocation of medical resources, compounded by the reluctance to seek help, makes it exceptionally challenging for people with non-communicable diseases (NCD) to manage their diseases. This review evaluates the spill-over impact of the COVID-19 pandemic on people with NCDs including cardiovascular diseases, cancer, diabetes mellitus, chronic respiratory disease, chronic kidney disease, dementia, mental health disorders, and musculoskeletal disorders. METHODS: Literature published in English was identified from PubMed and medRxiv from January 1, 2019 to November 30, 2020. A total of 119 articles were selected from 6,546 publications found. RESULTS: The reduction of in-person care, screening procedures, delays in diagnosis, treatment, and social distancing policies have unanimously led to undesirable impacts on both physical and psychological health of NCD patients. This is projected to contribute to more excess deaths in the future. CONCLUSION: The spill-over impact of COVID-19 on patients with NCD is just beginning to unravel, extra efforts must be taken for planning the resumption of NCD healthcare services post-pandemic

    Applications of Internet of Things

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    This editorial introduces the special issue entitled &ldquo;Applications of Internet of Things&rdquo;, of ISPRS International Journal of Geo-Information. Topics covered in this issue include three main parts: (I) intelligent transportation systems (ITS), (II) location-based services (LBS), and (III) sensing techniques and applications. Three papers on ITS are as follows: (1) &ldquo;Vehicle positioning and speed estimation based on cellular network signals for urban roads,&rdquo; by Lai and Kuo; (2) &ldquo;A method for traffic congestion clustering judgment based on grey relational analysis,&rdquo; by Zhang et al.; and (3) &ldquo;Smartphone-based pedestrian&rsquo;s avoidance behavior recognition towards opportunistic road anomaly detection,&rdquo; by Ishikawa and Fujinami. Three papers on LBS are as follows: (1) &ldquo;A high-efficiency method of mobile positioning based on commercial vehicle operation data,&rdquo; by Chen et al.; (2) &ldquo;Efficient location privacy-preserving k-anonymity method based on the credible chain,&rdquo; by Wang et al.; and (3) &ldquo;Proximity-based asynchronous messaging platform for location-based Internet of things service,&rdquo; by gon Jo et al. Two papers on sensing techniques and applications are as follows: (1) &ldquo;Detection of electronic anklet wearers&rsquo; groupings throughout telematics monitoring,&rdquo; by Machado et al.; and (2) &ldquo;Camera coverage estimation based on multistage grid subdivision,&rdquo; by Wang et al
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