使用Xcelium Machine Learning技术加速验证覆盖率收敛

随着设计越来越复杂,受约束的随机化验证方法已成为验证的主流方法。一般地,验证激励做到不违反spec描述条件下尽量随机,这样验证能跑到的空间才更充分。但是,这给功能覆盖率收敛带来极大挑战,为解决这一难题,Cadence率先推出了仿真器的机器学习功能——Xcelium Machine Learning,采用机器学习技术让功能覆盖率快速收敛,大大提高验证仿真效率。介绍了Xcelium Machine Learning的使用流程,并给出在相同模拟(simulation)验证环境下应用Machine Learning前后情况对比。最后Machine Learning在模拟(simulation)验证中的应用前景进行了展望。

Role of ghrelin in cognitive impairment of hypertensive elders with chronic psychological distress

Objective:To investigate ghrelin level change in combination with psychological stress in the hypertensive old people with cognitive impairment and to explore its effect as well as possible mechanism.Methods:The study population of 300 elders was divided into 2 groups,148 with hypertension and 152 non-hypertension,who were screened for psychological distress and cognition function,and had blood drawn to measure plasma levels of ghrelin and total cortisol on the same day.Results:The rates of anxiety and cognitive impairment were higher in the hypertension elders,which were negatively correlated with plasma ghrelin level,resulted from chronic cortisol response to anxiety.Conclusion:Chronic plasma cortisol increase to long-term anxiety leads a reduce in ghrelin level which then adversely affects blood pressure and cognitive function in old people.So measuring ghrelin of elders may be a diagnostic tool to predict cognitive development and ghrelin may be a selective antihypertensive medicine for cognitive impairment elders with or without chronic psychological stress.