1,523 research outputs found
Sensing With Random Signals
Radar systems typically employ well-designed deterministic signals for target
sensing. In contrast to that, integrated sensing and communications (ISAC)
systems have to use random signals to convey useful information, potentially
causing sensing performance degradation. This paper analyzes the sensing
performance via random ISAC signals over a multi-antenna system. Towards this
end, we define a new sensing performance metric, namely, ergodic linear minimum
mean square error (ELMMSE), which characterizes the estimation error averaged
over the randomness of ISAC signals. Then, we investigate a data-dependent
precoding scheme to minimize the ELMMSE, which attains the {optimized} sensing
performance at the price of high computational complexity. To reduce the
complexity, we present an alternative data-independent precoding scheme and
propose a stochastic gradient projection (SGP) algorithm for ELMMSE
minimization, which can be trained offline by locally generated signal samples.
Finally, we demonstrate the superiority of the proposed methods by simulations.Comment: 6 pages, 5 figures, submitted to ICASSP 202
Serum 25-hydroxyvitamin D levels and the risk of idiopathic central precocious puberty in girls
Introduction: Prior studies have found inconsistent results regarding the relationship between vitamin D status and Idiopathic Central Precocious Puberty (ICPP).
Objective: To assess the role of serum 25-hydroxyvitamin D (25 [OH]D) levels in ICPP development.
Method: The authors retrospectively collected data from 221 girls with ICPP and 144 healthy girls between January 2017 and December 2019. The participants’ serum 25(OH)D levels were measured using an automatic chemiluminescence method, and the association between serum 25(OH)D levels and the risk of ICPP was assessed using multivariate logistic regression analysis. Odds Ratios (OR) with 95% Confidence Intervals (95% CI) were calculated as effect estimates.
Results: Serum 25(OH)D levels in the ICPP group were significantly lower than those in healthy controls (p < 0.001). Multivariate analysis indicated that girls with insufficient vitamin D levels (OR = 0.201; 95% CI 0.094–0.428; p < 0.001) and sufficient vitamin D levels (OR = 0.141; 95% CI 0.053–0.375; p < 0.001) both had a lower risk of ICPP than girls with vitamin D deficiency. Moreover, the authors found that the height (p = 0.014), weight (p = 0.014), breast stage (p = 0.010), mother's height (p < 0.001), and luteinizing hormone/follicle-stimulating hormone ratio (p = 0.010) in girls with ICPP could be associated with levels of vitamin D.
Conclusion: This study found that a low serum 25(OH)D level is an independent risk factor for ICPP, and several characteristics of girls with ICPP could be affected by their vitamin D status.
Integration of Genetic Algorithm and Cultural Particle Swarm Algorithms for Constrained Optimization of Industrial Organization and Diffusion Efficiency Analysis in Equipment Manufacturing Industry
Abstract: Aiming at industrial organization multi-objective optimization problem in Equipment Manufacturing Industry, The paper proposes a new type of double layer evolutionary cultural particle swarm optimization algorithm. The algorithm combines the advantages of the particle swarm optimization algorithm and cultural algorithm. It not only revises the problem that the particles are easy to "premature", but also overcomes the drawback of penalty function method. Firstly, improved topology structure of Particle swarm optimization algorithm. Secondly, using crossover strategy and niche competition mechanism. Verified by the test functions, the proposed algorithm has good performance. Through the analysis of the manufacturing performance based on the algorithm, the paper proposes some optimization strategies such as improving the manufacturing industry market concentration, improving the manufacturing level of industry product differentiation and so on
Integration of Genetic Algorithm and Cultural Particle Swarm Algorithms for Constrained Optimization of Industrial Organization and Diffusion Efficiency Analysis in Equipment Manufacturing Industry
Aiming at industrial organization multi-objective optimization problem in Equipment Manufacturing Industry, The paper proposes a new type of double layer evolutionary cultural particle swarm optimization algorithm. The algorithm combines the advantages of the particle swarm optimization algorithm and cultural algorithm. It not only revises the problem that the particles are easy to "premature", but also overcomes the drawback of penalty function method. Firstly, improved topology structure of Particle swarm optimization algorithm. Secondly, using crossover strategy and niche competition mechanism. Verified by the test functions, the proposed algorithm has good performance. Through the analysis of the manufacturing performance based on the algorithm, the paper proposes some optimization strategies such as improving the manufacturing industry market concentration, improving the manufacturing level of industry product differentiation and so on
Expanded CURB-65: A new score system predicts severity of community-acquired pneumonia with superior efficiency
Aim of this study was to develop a new simpler and more effective severity score for communityacquired pneumonia (CAP) patients. A total of 1640 consecutive hospitalized CAP patients in Second
Affiliated Hospital of Zhejiang University were included. The effectiveness of different pneumonia
severity scores to predict mortality was compared, and the performance of the new score was validated
on an external cohort of 1164 patients with pneumonia admitted to a teaching hospital in Italy.
Using age≥ 65 years, LDH>230u/L, albumin<3.5g/dL, platelet count<100×109/L, confusion,
urea>7mmol/L, respiratory rate≥30/min, low blood pressure, we assembled a new severity score
named as expanded-CURB-65. The 30-day mortality and length of stay were increased along with
increased risk score. The AUCs in the prediction of 30-day mortality in the main cohort were 0.826
(95%CI, 0.807–0.844), 0.801 (95%CI, 0.781–0.820), 0.756 (95%CI, 0.735–0.777), 0.793 (95%CI,
0.773–0.813) and 0.759 (95%CI, 0.737–0.779) for the expanded-CURB-65, PSI, CURB-65, SMART-COP
and A-DROP, respectively. The performance of this bedside score was confirmed in CAP patients of
the validation cohort although calibration was not successful in patients with health care-associated
pneumonia (HCAP). The expanded CURB-65 is objective, simpler and more accurate scoring system for
evaluation of CAP severity, and the predictive efficiency was better than other score systems
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