期刊文献+
共找到3篇文章
< 1 >
每页显示 20 50 100
单波长近眼显示眼镜
1
作者 muhammad nouman 焦新光 +1 位作者 罗朝 梁海锋 《西安工业大学学报》 CAS 2021年第5期544-552,共9页
为适应单色增强现实光学系统体积更小、更易佩戴、视场更大、成像更清晰明亮的要求,文中基于双光栅和平面波导技术原理,完成了光学系统的设计和显示效果评价。基于Zemax软件实现了目镜光学系统、耦合光学系统、平面波导系统和耦合出系... 为适应单色增强现实光学系统体积更小、更易佩戴、视场更大、成像更清晰明亮的要求,文中基于双光栅和平面波导技术原理,完成了光学系统的设计和显示效果评价。基于Zemax软件实现了目镜光学系统、耦合光学系统、平面波导系统和耦合出系统模型优化及建立。以真实图像传输为目标,对仿真结果进行实验验证。实验研究表明:在单波长为532 nm,出瞳距离为8 mm条件下,系统结构正确合理,可以实现20°视场和10 mm的大出瞳显示,图像相似度为34.8。 展开更多
关键词 近眼显示 光学设计 衍射光栅 衍射光波导
在线阅读 下载PDF
Comparison of beta-blockers vs calcium channel blockers in heart failure with preserved ejection fraction
2
作者 Moaz Mansoor Faisal Nabi Depar +6 位作者 Hafiz Usama Talha Haroon Ur Rashid Ahmad Ashraf muhammad nouman Mohammad Abbas Maaz Tariq Abbasi Ali Sher 《World Journal of Cardiology》 2025年第12期84-93,共10页
BACKGROUND Heart failure with preserved ejection fraction(HFpEF)accounts for approximately half of heart failure cases and is associated with high morbidity and mortality.Beta-blockers(BB)and calcium channel blockers(... BACKGROUND Heart failure with preserved ejection fraction(HFpEF)accounts for approximately half of heart failure cases and is associated with high morbidity and mortality.Beta-blockers(BB)and calcium channel blockers(CCB)are commonly used for symptom control and comorbidity management,but their comparative effectiveness and safety remain unclear.AIM To compare the effectiveness and safety of BB vs CCB in patients with HFpEF using simulated real-world data and propensity score-matched analyses.METHODS Simulated data for 4000 HFpEF patients(2000 BB,2000 CCB)were generated based on distributions extracted from electronic medical records spanning 2014-2023.Inclusion criteria included adults with left ventricular ejection fraction≥50%and initiation of BB or CCB.Effectiveness outcomes encompassed mortality,heart failure hospitalizations,and changes in clinical parameters.Safety outcomes included bradycardia,hypotension,and drug discontinuation.Statistical analyses used t-tests,χ2 tests,Cox proportional hazards models for hazard ratios(HR),and incidence rate ratios(IRR)in R software.Propensity score matching(PSM)was performed to balance baseline characteristics,with outcomes reassessed in the matched cohort.RESULTS Baseline characteristics were largely balanced,with minor differences in sex,chronic kidney disease,systolic blood pressure,and left atrial volume index.BB demonstrated lower all-cause mortality(crude HR 0.78,95%CI:0.70-0.87,P=0.003),heart failure hospitalization(crude HR 0.86,95%CI:0.77-0.96,P=0.031),and composite endpoint(crude HR 0.85,95%CI:0.79-0.91,P<0.001)rates compared to CCB.IRR for heart failure hospitalizations and emergency visits favored BB.Safety profiles showed higher symptomatic bradycardia(9.2%vs 4.9%,P<0.001)and drug discontinuation(11.3%vs 9.3%,P=0.043)with BB,and higher hypotension(7.2%vs 11.5%,P<0.001)with CCB.Matched analyses showed all-cause mortality rates of 0.0622 per person-year for BB vs 0.0649 for CCB(HR 0.96,95%CI:0.85-1.08),heart failure hospitalization rates of 0.0751 vs 0.0888(HR 0.84,95%CI:0.75-0.94),and IRR for number of heart failure hospitalizations of 1.65 for CCB vs BB(95%CI:1.51-1.80,P<0.001).CONCLUSION BB may offer potential advantages in reducing mortality and hospitalizations in HFpEF compared to CCB,with distinct safety considerations.PSM confirmed these trends with reduced confounding.Personalized therapy is recommended,warranting prospective trials for validation. 展开更多
关键词 Heart failure with preserved ejection fraction BETA-BLOCKERS Calcium channel blockers MORTALITY HOSPITALIZATION
暂未订购
Towards a lightweight security framework using blockchain and machine learning 被引量:1
3
作者 Shereen Ismail muhammad nouman +1 位作者 Diana W.Dawoud Hassan Reza 《Blockchain(Research and Applications)》 EI 2024年第1期107-118,共12页
Cyber-attacks pose a significant challenge to the security of Internet of Things(IoT)sensor networks,necessitating the development of robust countermeasures tailored to their unique characteristics and limitations.Var... Cyber-attacks pose a significant challenge to the security of Internet of Things(IoT)sensor networks,necessitating the development of robust countermeasures tailored to their unique characteristics and limitations.Various prevention and detection techniques have been proposed to mitigate these attacks.In this paper,we propose an integrated security framework using blockchain and Machine Learning(ML)to protect IoT sensor networks.The framework consists of two modules:a blockchain prevention module and an ML detection module.The blockchain prevention module has two lightweight mechanisms:identity management and trust management.Identity management employs a lightweight Smart Contract(SC)to manage node registration and authentication,ensuring that unauthorized entities are prohibited from engaging in any tasks,while trust management uses a lightweight SC that is responsible for maintaining trust and credibility between sensor nodes throughout the network’s lifetime and tracking historical node behaviors.Consensus and transaction validation are achieved through a Verifiable Byzantine Fault Tolerance(VBFT)mechanism to ensure network reliability and integrity.The ML detection module utilizes the Light Gradient Boosting Machine(LightGBM)algorithm to classify malicious nodes and notify the blockchain network if it must make decisions to mitigate their impacts.We investigate the performance of several off-the-shelf ML algorithms,including Logistic Regression,Complement Naive Bayes,Nearest Centroid,and Stacking,using the WSN-DS dataset.LightGBM is selected following a detailed comparative analysis conducted using accuracy,precision,recall,F1-score,processing time,training time,prediction time,computational complexity,and Matthews Correlation Coefficient(MCC)evaluation metrics. 展开更多
关键词 Blockchain Machine learning IOT SECURITY INTEGRATION Smart contracts
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部