Minkowski sums are of theoretical interest and have applications in fields related to industrial backgrounds. In this paper we focus on the specific case of summing polytopes as we want to solve the tolerance analysis...Minkowski sums are of theoretical interest and have applications in fields related to industrial backgrounds. In this paper we focus on the specific case of summing polytopes as we want to solve the tolerance analysis problem described in [1]. Our approach is based on the use of linear programming and is solvable in polynomial time. The algorithm we developed can be implemented and parallelized in a very easy way.展开更多
5G通信基站通常配备光储,数量庞大、功耗可调,是一种优质的电力灵活性调节资源。提出了多类型光储式5G基站集群灵活性资源聚合方法以及参与电网调峰的协同调度策略。首先,分析休眠机制下多类型基站功耗可调特性与计及基站备用电量的储...5G通信基站通常配备光储,数量庞大、功耗可调,是一种优质的电力灵活性调节资源。提出了多类型光储式5G基站集群灵活性资源聚合方法以及参与电网调峰的协同调度策略。首先,分析休眠机制下多类型基站功耗可调特性与计及基站备用电量的储能调节能力。基于极限场景思想,构建了光储式5G基站的灵活性空间量化模型。在此基础上,利用闵可夫斯基和法刻画异构基站柔性资源的时空耦合能量轨迹,得到海量基站集群的灵活性资源聚合可调域。其次,建立了基站集群聚合资源参与电能量市场和辅助服务市场的协同调度优化模型,提出了基于交替方向乘子法(alternating direction method of multipliers, ADMM)的分层分布式基站集群协同优化调度策略,将大规模基站集群调度问题降维分解为统一协同调峰功率响应、聚合功率自治调度和基站集群功率分配3个子问题进行求解。通过算例对比分析可知,所提策略可降低通信基站69.86%的用能成本,为提升通信资源利用率和电力系统灵活调节能力提供了有效手段。展开更多
温控负荷(temperature control loads,TCLs)灵活性可行域的有效量化和聚合是其响应电价与调控信号的前提。由于TCLs能量在时间上耦合,且设备调节特性和物理参数各异,具有较高异质性,现有聚合方法面临计算复杂度高、适配性差等问题。该...温控负荷(temperature control loads,TCLs)灵活性可行域的有效量化和聚合是其响应电价与调控信号的前提。由于TCLs能量在时间上耦合,且设备调节特性和物理参数各异,具有较高异质性,现有聚合方法面临计算复杂度高、适配性差等问题。该文基于极端场景法建立了通用虚拟电池(virtual battery,VB)模型,即通过一套标准电池参数描述资源灵活性,其通用形式使得聚合可行域可以按一定规则线性求和获得。在此基础上,提出一种基于虚拟电池模型的外逼近闵可夫斯基聚合方法,并从数学上不失一般性地对不同异质性设备聚合的有效性进行了证明与推广。最后,提出了考虑系统灵活性供需平衡的负荷聚合商日前优化调度模型。算例结果表明,所提温控负荷可行域聚合方法在提高了外逼近精度的同时保证了较高的计算效率。相比传统模型,所提聚合模型有着更好的优化性能。展开更多
In this paper,we first establish the dual Brunn-Minkowski inequality for the star duals for the Lp radial sum.Furthermore,we give some Brunn-Minkowski inequalities for the star duals of intersection bodies for the Lp ...In this paper,we first establish the dual Brunn-Minkowski inequality for the star duals for the Lp radial sum.Furthermore,we give some Brunn-Minkowski inequalities for the star duals of intersection bodies for the Lp radial sum and the Lp harmonic Blaschke sum.展开更多
A method for packing irregular particles with a prescribed volume fraction is proposed.Furthermore,the generated granular material adheres to the prescribed statistical distribution and satisfies the desired complex s...A method for packing irregular particles with a prescribed volume fraction is proposed.Furthermore,the generated granular material adheres to the prescribed statistical distribution and satisfies the desired complex spatial arrangement.First,the irregular geometries of the realistic particles were obtained from the original particle images.Second,the Minkowski sum was used to check the overlap between irregular particles and place an irregular particle in contact with other particles.Third,the optimised advance front method(OAFM)generated irregular particle packing with the prescribed statistical dis-tribution and volume fraction based on the Minkowski sum.Moreover,the signed distance function was introduced to pack the particles in accordance with the desired spatial arrangement.Finally,seven biaxial tests were performed using the UDEC software,which demonstrated the accuracy and potential usefulness of the proposed method.It can model granular material efficiently and reflect the meso-structural characteristics of complex granular materials.This method has a wide range of applications where discrete modelling of granular media is necessary.展开更多
文摘Minkowski sums are of theoretical interest and have applications in fields related to industrial backgrounds. In this paper we focus on the specific case of summing polytopes as we want to solve the tolerance analysis problem described in [1]. Our approach is based on the use of linear programming and is solvable in polynomial time. The algorithm we developed can be implemented and parallelized in a very easy way.
文摘5G通信基站通常配备光储,数量庞大、功耗可调,是一种优质的电力灵活性调节资源。提出了多类型光储式5G基站集群灵活性资源聚合方法以及参与电网调峰的协同调度策略。首先,分析休眠机制下多类型基站功耗可调特性与计及基站备用电量的储能调节能力。基于极限场景思想,构建了光储式5G基站的灵活性空间量化模型。在此基础上,利用闵可夫斯基和法刻画异构基站柔性资源的时空耦合能量轨迹,得到海量基站集群的灵活性资源聚合可调域。其次,建立了基站集群聚合资源参与电能量市场和辅助服务市场的协同调度优化模型,提出了基于交替方向乘子法(alternating direction method of multipliers, ADMM)的分层分布式基站集群协同优化调度策略,将大规模基站集群调度问题降维分解为统一协同调峰功率响应、聚合功率自治调度和基站集群功率分配3个子问题进行求解。通过算例对比分析可知,所提策略可降低通信基站69.86%的用能成本,为提升通信资源利用率和电力系统灵活调节能力提供了有效手段。
文摘温控负荷(temperature control loads,TCLs)灵活性可行域的有效量化和聚合是其响应电价与调控信号的前提。由于TCLs能量在时间上耦合,且设备调节特性和物理参数各异,具有较高异质性,现有聚合方法面临计算复杂度高、适配性差等问题。该文基于极端场景法建立了通用虚拟电池(virtual battery,VB)模型,即通过一套标准电池参数描述资源灵活性,其通用形式使得聚合可行域可以按一定规则线性求和获得。在此基础上,提出一种基于虚拟电池模型的外逼近闵可夫斯基聚合方法,并从数学上不失一般性地对不同异质性设备聚合的有效性进行了证明与推广。最后,提出了考虑系统灵活性供需平衡的负荷聚合商日前优化调度模型。算例结果表明,所提温控负荷可行域聚合方法在提高了外逼近精度的同时保证了较高的计算效率。相比传统模型,所提聚合模型有着更好的优化性能。
基金Project supported by the National Natural Science Foundation of China (Grant No.10671119)the Shanghai Leading Academic Discipline Project (Grant No.J50101)the Shanghai University Graduate Innovation Foundation Project (GrantNo.SHUCX092003)
文摘In this paper,we first establish the dual Brunn-Minkowski inequality for the star duals for the Lp radial sum.Furthermore,we give some Brunn-Minkowski inequalities for the star duals of intersection bodies for the Lp radial sum and the Lp harmonic Blaschke sum.
基金The authors would like to acknowledge the financial support provided by the National Key R&D Program of China(Grant No.2018YFC1504802)the National Natural Science Foundation of China(Grant Nos.41972266,12102230).
文摘A method for packing irregular particles with a prescribed volume fraction is proposed.Furthermore,the generated granular material adheres to the prescribed statistical distribution and satisfies the desired complex spatial arrangement.First,the irregular geometries of the realistic particles were obtained from the original particle images.Second,the Minkowski sum was used to check the overlap between irregular particles and place an irregular particle in contact with other particles.Third,the optimised advance front method(OAFM)generated irregular particle packing with the prescribed statistical dis-tribution and volume fraction based on the Minkowski sum.Moreover,the signed distance function was introduced to pack the particles in accordance with the desired spatial arrangement.Finally,seven biaxial tests were performed using the UDEC software,which demonstrated the accuracy and potential usefulness of the proposed method.It can model granular material efficiently and reflect the meso-structural characteristics of complex granular materials.This method has a wide range of applications where discrete modelling of granular media is necessary.