An Extreme Value Approach to Test the Effect of Price Limits on Volatility

Many stock exchanges around the world enforcing daily price limits on the amount asset prices can change to prevent the market from overreacting and to reduce volatility. Price limits are artificial boundaries set by market regulators who restrict price changes of a stock to a pre-specified range during a trading day or a single trading session. The primary aim of price limit rules is to stabilize the markets during panic trading, to moderate vitality by repressing excessive speculation, and to allow stocks to be traded at prices close to their fair value. However, their impact on the market is a somewhat unresolved issue （Harris, 1998）. Using a methodology of comparing volatility based on the extreme value technique, the authors empirically investigate the impact of price limits on the volatility of the Stock Exchange of Thailand. The empirical results support price limits advocates, suggesting that price limits rules moderate stock price volatility.

半刚性基层沥青混凝土路面疲劳开裂控制因素研究

研究半刚性基层沥青混凝土路面早期开裂的原因,确定疲劳开裂控制因素。进行道路结构足尺应变测试,并采用有限元数值模拟技术对道路结构内部应力场及应变场进行相应分析。以应力水平大小确定疲劳开裂控制因素。依据足尺试验测试结果及数值模拟计算结果分析可知,半刚性基层沥青混凝土路面在荷载作用下结构内部存在明显的受压区、弱拉区及强拉区分布,其中强拉区在道路结构内部连续分布。底基层最大应力水平达到85%。半刚性基层沥青混凝土路面疲劳开裂的控制因素应为底基层强度特性,底基层开裂引发的反射裂缝现象应是路面早期开裂的主要原因。