18 research outputs found

    Loop Closure Detection Based on Object-level Spatial Layout and Semantic Consistency

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    Visual simultaneous localization and mapping (SLAM) systems face challenges in detecting loop closure under the circumstance of large viewpoint changes. In this paper, we present an object-based loop closure detection method based on the spatial layout and semanic consistency of the 3D scene graph. Firstly, we propose an object-level data association approach based on the semantic information from semantic labels, intersection over union (IoU), object color, and object embedding. Subsequently, multi-view bundle adjustment with the associated objects is utilized to jointly optimize the poses of objects and cameras. We represent the refined objects as a 3D spatial graph with semantics and topology. Then, we propose a graph matching approach to select correspondence objects based on the structure layout and semantic property similarity of vertices' neighbors. Finally, we jointly optimize camera trajectories and object poses in an object-level pose graph optimization, which results in a globally consistent map. Experimental results demonstrate that our proposed data association approach can construct more accurate 3D semantic maps, and our loop closure method is more robust than point-based and object-based methods in circumstances with large viewpoint changes

    An improved fault control strategy for virtual synchronous generator with the coordination of STATCOM during unbalanced fault

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    The virtual synchronous generator (VSG) is a good solution for stabilizing the power system with high penetration of renewable energy. However, in case of serious unbalanced voltage disturbance/fault, the conventional VSG may lose voltage, inertia, and damping support characteristics to the grid and even can cause disconnection of renewable energy. This paper proposes an improved fault control strategy for VSG with the coordination of STATCOM. The proposed method can provide sufficient voltage support while keeping continuous system inertia and damping support under severe unbalanced fault. In the paper, an improved VSG and STATCOM control topology based on positive and negative sequence current control are first proposed so as to keep the damping and inertia support to grid during the grid fault. Secondly, the voltage support control method for the VSG with improved topology during unbalanced fault is introduced, which can achieve multiple control objectives, in terms of voltage support, current limitation, and active power output simultaneously. Then a coordination control scheme of improved VSG and STATCOM is developed so as to optimize the maximum control objectives in all possible scenarios, especially in the case of severe unbalanced fault. Finally, the effectiveness of the method is verified by using the MATLAB/SIMULINK simulation platform

    Gender Disparities in Lipid Goal Attainment among Type 2 Diabetes Outpatients with Coronary Heart Disease: Results from the CCMR-3B Study

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    Abstract Our study was aimed to investigate the gender disparities in lipid goal attainment among type 2 diabetes outpatients with concomitant coronary heart disease (CHD) and explore potential risk factors. We performed the present analysis using data from a nationally representative epidemiologic study. The therapeutic goal was defined as achieving a low-density lipoprotein cholesterol (LDL-C) <1.8 mmol/L. A total of 1721 male and 2072 female type 2 diabetes outpatients with established CHD were identified. Compared with men, women had higher levels of total cholesterol (4.98 vs. 4.46 mmol/L; p < 0.001), LDL-C (2.82 vs. 2.54 mmol/L; p < 0.001), and triglycerides (2.02 vs. 1.79 mmol/L; p < 0.001), but not hemoglobin A1c (7.47% vs. 7.50%; p = 0.597). The proportion of women received lipid-lowering therapy was lower (38.1% vs. 48.2%; p < 0.001). The percentages of patients who achieved the LDL-C goal were higher among men. Multivariable regression analysis indicated that the odds ratio for lipid goal attainment due to the gender difference was 0.61 after adjusting confounders. The inability to achieve LDL-C goals in women with type 2 diabetes and CHD is apparently greater than that in men. This finding underscores the importance of initiatives to establish a more aggressive lipid management strategy for women to overcome gender imbalances

    Prevalence of Obesity and Its Influence on Achievement of Cardiometabolic Therapeutic Goals in Chinese Type 2 Diabetes Patients: An Analysis of the Nationwide, Cross-Sectional 3B Study.

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    BACKGROUND:There are few data on the prevalence of obesity and its influence on achieving blood glucose, blood pressure, and blood lipid (3B) goals in Chinese type 2 diabetes outpatients. METHODS:Patient demographic data, anthropometric measurements, medications, and blood glucose and lipid profiles of 24,512 type 2 diabetes patients from a large, geographically diverse study (CCMR-3B) were analyzed. Using cut-points for body mass index (BMI) and waist circumference (WC) recommended by the Working Group on Obesity in China, overweight and obesity were defined as BMIs of 24-27.9 kg/m2 and ≥28.0 kg/m2. Central obesity was defined as a waist circumference ≥80 cm in women and ≥85 cm in men. The 3B therapeutic goals were HbA1c<7.0%, BP<140/90 mmHg and LDL-C<2.6 mmol/L. RESULTS:Overall, 43.0% of type 2 diabetes patients were overweight and 16.7% were obese; 13.3% of overweight and and 10.1% of obese patients achieved all the 3B target goals. Overweight or obese patients were less likely to achieve 3B goals than those with normal BMIs. More than a half the overweight or obese patients (69.6%) were centrally obese. Patients with abdominal obesity were less likely to achieve cardiometabolic targets than those without abdominal obesity. In multivariate logistic regression analysis, female, higher BMI and waist circumference, smoking, drinking, sedentary lifestyle, and longer diabetes duration were significantly correlated with failure to achieve 3B control goals. CONCLUSIONS:Obesity is highly prevalent and associated with poor 3B control in Chinese type 2 diabetes patients. In clinical practice, more attention and resources should focus on weight loss for such patients

    二甲双胍日剂量和治疗时间对中国2型糖尿病患者维生素B12缺乏和周围神经病变患病率的影响:一项多中心横断面研究

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    Abstract Aims To evaluate the prevalence of vitamin B12 deficiency in Chinese patients with type 2 diabetes mellitus receiving metformin treatment and to investigate the effects of metformin daily dose and treatment duration on the prevalence of vitamin B12 deficiency and peripheral neuropathy (PN). Materials and Methods In this multicenter cross‐sectional study, 1027 Chinese patients who had been taking ≥1000 mg/day metformin for ≥1 year were enrolled using proportionate stratified random sampling based on daily dose and treatment duration. Primary measures included the prevalence of vitamin B12 deficiency (<148 pmol/L), borderline B12 deficiency (148 pmol/L‐211 pmol/L), and PN. Results The prevalence of vitamin B12 deficiency, borderline deficiency, and PN were 2.15%, 13.66%, and 11.59%, respectively. Patients receiving ≥1500 mg/day metformin had significantly higher prevalence of borderline vitamin B12 deficiency (16.76% vs. 9.91%, p = .0015) and serum B12 ≤221 pmol/L (19.25% vs. 11.64%, p < .001) than patients receiving <1500 mg/day metformin. No difference was found in prevalence of borderline vitamin B12 deficiency (12.58% vs. 15.49%, p = .1902) and serum B12 ≤221 pmol/L (14.91% vs. 17.32%, p = .3055) between patients receiving metformin for ≥3 and <3 years. Patients with vitamin B12 deficiency had numerically higher PN prevalence (18.18% vs. 11.27%, p = .3192) than patients without it. Multiple logistic analyses revealed that HbA1c and metformin daily dose were associated with the prevalence of borderline B12 deficiency and B12 ≤221 pmol/L. Conclusions High daily dosage (≥1500 mg/day) played an important role in metformin‐associated vitamin B12 deficiency while not contributing to the risk of PN

    Prevalence of hypertension in china: a cross-sectional study.

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    AIMS: The present study aimed to assess the prevalence of hypertension among Chinese adults. METHODS: Data were obtained from sphygmomanometer measurements and a questionnaire administered to 46239 Chinese adults ≥20 years of age who participated in the 2007-2008 China National Diabetes and Metabolic Disorders Study. Hypertension was defined as blood pressure ≥140/90 mm Hg or use of antihypertensive medication. RESULTS: A total of 26.6% of Chinese adults had hypertension, and a significantly greater number of men were hypertensive than women (29.2% vs 24.1%, p<0.001). The age-specific prevalence of hypertension was 13.0%, 36.7%, and 56.5% among persons aged 20 to 44 years (young people), 45 to 64 years (middle-aged people), and ≥65 years (elderly people), respectively. In economically developed regions, the prevalence of hypertension was significantly higher among rural residents than among urban residents (31.3% vs 29.2%, p = 0.001). Among women or individuals who lived in the northern region, the disparity in the prevalence of hypertension between urban and rural areas disappeared (women: 24.0% vs. 24.0%, p = 0.942; northern region: 31.6% vs. 31.2%, p = 0.505). Among hypertensive patients, 45.0% were aware of their condition, 36.2% were treated, and 11.1% were adequately controlled. CONCLUSIONS: The prevalence of hypertension in China is increasing. The trend of an increase in prevalence is striking in young people and rural populations. Hypertension awareness, treatment, and control are poor. Public health efforts for further improving awareness and enhancing effective control are urgently needed in China, especially in emerging populations

    Trends in the prevalence of hypertension among Chinese aged ≥20 years from 1991 to 2007–2008.

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    <p>(A) Trends in the prevalence of hypertension among men from 1991 to 2007–2008 according to different age groups. (B) Trends in the prevalence of hypertension among women. (C) Trends in the prevalence of hypertension in the overall population between 1991 and 2007–2008. Bars indicate 95% confidence intervals.</p

    Age-specific prevalence of hypertension and mean blood pressure levels among Chinese aged ≥20 years.

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    <p>The prevalence of hypertension (A), mean systolic blood pressure levels (B) and mean diastolic blood pressure levels (C) among men and women are shown according to age. Bars indicate 95% confidence intervals.</p

    2004 ‐ 2014年中国1型糖尿病妇女妊娠结局:回顾性研究(CARNATION研究)

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    Abstract Background We aimed to report pregnancy outcomes of women with type 1 diabetes (T1D) in China, on which data were sparse. Methods This is a nationwide retrospective study conducted in 11 general medical centers in 8 cities across China. We investigated the clinical data of all women who attended these centers with a singleton pregnancy and whose pregnancy ended between 1 January 2004 and 31 December 2014. Pregnancies of women with pregestational T1D were ascertained and compared with those of women without T1D. Results From over 300 000 pregnancies over the 11‐year study period, we identified 265 singleton pregnancies of women with T1D. One maternal death was documented among 265 (0.37%) women with T1D and 83 among 318 486 (0.03%) women without T1D. Women with T1D suffered from higher rates of pregnancy loss (13.21% vs 2.92%, crude risk ratio [cRR] 5.08 [95% CI, 3.56‐7.26]) and preeclampsia (17.74% vs 4.20%, cRR 4.94 [95% CI, 3.60‐6.77]) compared with those without T1D. Infants of these women with T1D had elevated rates of neonatal death (5.65% vs 0.16%, cRR 37.36 [95% CI, 21.21‐65.82]) and congenital malformation(s) (8.26% vs 3.53%, cRR 2.46 [95% CI, 1.54‐3.93]) compared with those of women without T1D. No significant improvement in pregnancy outcomes in women with T1D was observed over the period 2004 to 2014. Conclusions Pregnancy outcomes were persistently poor in women with T1D during 2004 to 2014 in China. Pregnancy care needs to be improved to reduce adverse pregnancy outcomes among Chinese women with T1D
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