In this paper, we discuss a special class of sets of bivariate empirical points, namely, numerical cartesian sets. We find that the stable quotient bases for numerical cartesian sets are unique if they exist. Furtherm...In this paper, we discuss a special class of sets of bivariate empirical points, namely, numerical cartesian sets. We find that the stable quotient bases for numerical cartesian sets are unique if they exist. Furthermore, the corresponding border bases are the unique stable border bases for the vanishing ideals of numerical cartesian sets.展开更多
针对量子时代下属性基加密(attribute-based encryption,ABE)机制中访问结构设计较复杂的问题,结合Zhu等提出的基于R-LWE(learning with error over ring)的属性基加密方案,提出一种理想格上支持树形访问结构的密文策略属性基加密方案...针对量子时代下属性基加密(attribute-based encryption,ABE)机制中访问结构设计较复杂的问题,结合Zhu等提出的基于R-LWE(learning with error over ring)的属性基加密方案,提出一种理想格上支持树形访问结构的密文策略属性基加密方案。该方案将格理论应用到属性基加密机制中,采用访问树表示访问策略。访问树的叶子节点表示属性,非叶子结点表示策略操作符,通过Shamir秘密共享技术构造灵活的访问表达式,支持访问策略的与、或、门限操作,实现对密文的访问控制。理想格上的加密方案具有私钥尺寸小、运算效率高等优点。该方案基于理想格上RLWE难题,满足标准模型下选择明文攻击安全。通过与相关方案对比分析表明,该方案在保证性能不变的前提下,能够抵抗量子攻击,实现灵活的访问策略。展开更多
This paper illustrates a new bi-objective optimization model of real-time automatic generation control dispatch in a performance-based frequency regulation market.It attempts to simultaneously minimize the total power...This paper illustrates a new bi-objective optimization model of real-time automatic generation control dispatch in a performance-based frequency regulation market.It attempts to simultaneously minimize the total power deviation and the regulation mileage payment via optimally distributing the realtime total generation command to different regulation units.To handle this problem,an efficient non-dominated sorting genetic algorithm II is adopted to rapidly obtain a high-quality Pareto front for real-time AGC dispatch.A dynamic ideal point based decision making technique is designed to select the best compromise solution from the obtained Pareto front according to the minimization of the total regulation variation,which can effectively avoid an excessive regulation variation for each unit.Finally,two testing systems are used to verify the performance of the proposed technique.展开更多
理想格上的加密方案具有密钥尺寸小、加密效率高的优势,利用理想格环上带误差学习(R-LWE,ring learning with error)问题,构造一种可以保护用户属性隐私的属性基加密方案,支持灵活的访问策略,提供用户隐私保护,并且提高方案效率,缩短密...理想格上的加密方案具有密钥尺寸小、加密效率高的优势,利用理想格环上带误差学习(R-LWE,ring learning with error)问题,构造一种可以保护用户属性隐私的属性基加密方案,支持灵活的访问策略,提供用户隐私保护,并且提高方案效率,缩短密钥尺寸。该方案通过采用半策略隐藏方式,保护用户的隐私,从而避免用户的敏感属性值泄露给其他任何第三方。另外,将扩展的Shamir门限秘密共享技术应用于构造方案的访问结构,从而实现用户属性的"与""或""门限"这3种操作,具有更高的灵活性。经安全性分析证明,该方案在标准模型下满足自适应选择明文攻击安全。通过与其他方案的对比,该方案系统公钥、系统私钥、用户私钥长度以及密文长度都有所优化,在实际应用中更加有效。展开更多
电力系统运行在非理想状态时,容易产生短暂的电压波动,此时并联有源电力滤波器(shunt active power filter,SAPF)采用无源控制策略无法高效、精确地调节电能质量,而常规滑模控制又容易引起抖振。针对上述情况,将无源控制和抗干扰能力更...电力系统运行在非理想状态时,容易产生短暂的电压波动,此时并联有源电力滤波器(shunt active power filter,SAPF)采用无源控制策略无法高效、精确地调节电能质量,而常规滑模控制又容易引起抖振。针对上述情况,将无源控制和抗干扰能力更强的超螺旋二阶滑模控制相结合,提出了一种无源超螺旋二阶滑模控制策略。首先,根据有源电力滤波器的数学模型建立基于正负序分离的欧拉−拉格朗日模型;其次,对系统的模型进行了无源性分析,且根据其无源性设计了无源控制器,同时采用超螺旋二阶滑模控制对无源控制器进一步优化,提高了系统整体的鲁棒性和抗干扰能力;最后,在理想状态和负载突变、负载不平衡、电网电压不平衡、单相电压突变4种非理想状态下,通过仿真实验验证了无源超螺旋二阶滑模控制策略的有效性和优越性。展开更多
基金Partially supported by the National Grand Fundamental Research 973 Program (2004CB318000) of China
文摘In this paper, we discuss a special class of sets of bivariate empirical points, namely, numerical cartesian sets. We find that the stable quotient bases for numerical cartesian sets are unique if they exist. Furthermore, the corresponding border bases are the unique stable border bases for the vanishing ideals of numerical cartesian sets.
文摘针对量子时代下属性基加密(attribute-based encryption,ABE)机制中访问结构设计较复杂的问题,结合Zhu等提出的基于R-LWE(learning with error over ring)的属性基加密方案,提出一种理想格上支持树形访问结构的密文策略属性基加密方案。该方案将格理论应用到属性基加密机制中,采用访问树表示访问策略。访问树的叶子节点表示属性,非叶子结点表示策略操作符,通过Shamir秘密共享技术构造灵活的访问表达式,支持访问策略的与、或、门限操作,实现对密文的访问控制。理想格上的加密方案具有私钥尺寸小、运算效率高等优点。该方案基于理想格上RLWE难题,满足标准模型下选择明文攻击安全。通过与相关方案对比分析表明,该方案在保证性能不变的前提下,能够抵抗量子攻击,实现灵活的访问策略。
基金supported by National Natural Science Foundation of China(51907112,61963020)Natural Science Foundation of Guangdong Province of China(2019A1515011671).
文摘This paper illustrates a new bi-objective optimization model of real-time automatic generation control dispatch in a performance-based frequency regulation market.It attempts to simultaneously minimize the total power deviation and the regulation mileage payment via optimally distributing the realtime total generation command to different regulation units.To handle this problem,an efficient non-dominated sorting genetic algorithm II is adopted to rapidly obtain a high-quality Pareto front for real-time AGC dispatch.A dynamic ideal point based decision making technique is designed to select the best compromise solution from the obtained Pareto front according to the minimization of the total regulation variation,which can effectively avoid an excessive regulation variation for each unit.Finally,two testing systems are used to verify the performance of the proposed technique.
文摘理想格上的加密方案具有密钥尺寸小、加密效率高的优势,利用理想格环上带误差学习(R-LWE,ring learning with error)问题,构造一种可以保护用户属性隐私的属性基加密方案,支持灵活的访问策略,提供用户隐私保护,并且提高方案效率,缩短密钥尺寸。该方案通过采用半策略隐藏方式,保护用户的隐私,从而避免用户的敏感属性值泄露给其他任何第三方。另外,将扩展的Shamir门限秘密共享技术应用于构造方案的访问结构,从而实现用户属性的"与""或""门限"这3种操作,具有更高的灵活性。经安全性分析证明,该方案在标准模型下满足自适应选择明文攻击安全。通过与其他方案的对比,该方案系统公钥、系统私钥、用户私钥长度以及密文长度都有所优化,在实际应用中更加有效。
文摘电力系统运行在非理想状态时,容易产生短暂的电压波动,此时并联有源电力滤波器(shunt active power filter,SAPF)采用无源控制策略无法高效、精确地调节电能质量,而常规滑模控制又容易引起抖振。针对上述情况,将无源控制和抗干扰能力更强的超螺旋二阶滑模控制相结合,提出了一种无源超螺旋二阶滑模控制策略。首先,根据有源电力滤波器的数学模型建立基于正负序分离的欧拉−拉格朗日模型;其次,对系统的模型进行了无源性分析,且根据其无源性设计了无源控制器,同时采用超螺旋二阶滑模控制对无源控制器进一步优化,提高了系统整体的鲁棒性和抗干扰能力;最后,在理想状态和负载突变、负载不平衡、电网电压不平衡、单相电压突变4种非理想状态下,通过仿真实验验证了无源超螺旋二阶滑模控制策略的有效性和优越性。
