Since the 1980s, China’s commercial housing market has shown an unprecedented rapid development, and the commercial houses still has a high price. This paper studies the sales rate of commercial housing sales to find...Since the 1980s, China’s commercial housing market has shown an unprecedented rapid development, and the commercial houses still has a high price. This paper studies the sales rate of commercial housing sales to find an appropriate model, and it analyzes the volatility of the commercial housing market to describe the sustainable development of the commercial housing market. By selecting month data of China’s commercial housing sales from January 2006 to October 2018, this paper uses EViews7.2 and the ARMA Model as the tool in order to establish EARCH(1,1) through the method of quantitative analysis. It is found that the yield of commercial housing sales has obvious cluster, asymmetry and leverage effect, and the impact of adverse news on the commercial housing market is more significant than the impact of favorable news.展开更多
针对现有的可搜索加密算法在多用户环境中密钥管理难度大并且缺乏细粒度访问控制机制的问题,利用基于密文策略的属性加密机制(CP-ABE,ciphertext-policy attribute based encryption)实现了对隐藏关键词可搜索加密方案的细粒度访问控制...针对现有的可搜索加密算法在多用户环境中密钥管理难度大并且缺乏细粒度访问控制机制的问题,利用基于密文策略的属性加密机制(CP-ABE,ciphertext-policy attribute based encryption)实现了对隐藏关键词可搜索加密方案的细粒度访问控制。数据拥有者可以为其在第三方服务器中存储的加密指定灵活的访问策略,只有自身属性满足该访问策略的用户才有权限对数据进行检索和解密。同时还能够实现对用户的增加与撤销。安全性分析表明方案不仅可以有效地防止隐私数据的泄露,还可以隐藏关键词的信息,使得第三方服务器在提供检索功能的同时无法窃取用户的任何敏感信息。方案的效率分析表明,该系统的检索效率仅为数十微秒,适合在大型应用系统中使用。展开更多
文摘Since the 1980s, China’s commercial housing market has shown an unprecedented rapid development, and the commercial houses still has a high price. This paper studies the sales rate of commercial housing sales to find an appropriate model, and it analyzes the volatility of the commercial housing market to describe the sustainable development of the commercial housing market. By selecting month data of China’s commercial housing sales from January 2006 to October 2018, this paper uses EViews7.2 and the ARMA Model as the tool in order to establish EARCH(1,1) through the method of quantitative analysis. It is found that the yield of commercial housing sales has obvious cluster, asymmetry and leverage effect, and the impact of adverse news on the commercial housing market is more significant than the impact of favorable news.
文摘针对现有的可搜索加密算法在多用户环境中密钥管理难度大并且缺乏细粒度访问控制机制的问题,利用基于密文策略的属性加密机制(CP-ABE,ciphertext-policy attribute based encryption)实现了对隐藏关键词可搜索加密方案的细粒度访问控制。数据拥有者可以为其在第三方服务器中存储的加密指定灵活的访问策略,只有自身属性满足该访问策略的用户才有权限对数据进行检索和解密。同时还能够实现对用户的增加与撤销。安全性分析表明方案不仅可以有效地防止隐私数据的泄露,还可以隐藏关键词的信息,使得第三方服务器在提供检索功能的同时无法窃取用户的任何敏感信息。方案的效率分析表明,该系统的检索效率仅为数十微秒,适合在大型应用系统中使用。