Motivated by the count sketch maximal weighted residual Kaczmarz (CS-MWRK) method presented by Zhang and Li (Appl. Math. Comput., 410, 126486), we combine the count sketch tech with the maximal weighted residual Kaczm...Motivated by the count sketch maximal weighted residual Kaczmarz (CS-MWRK) method presented by Zhang and Li (Appl. Math. Comput., 410, 126486), we combine the count sketch tech with the maximal weighted residual Kaczmarz Method with Oblique Projection (MWRKO) constructed by Wang, Li, Bao and Liu (arXiv: 2106.13606) to develop a new method for solving highly overdetermined linear systems. The convergence rate of the new method is analyzed. Numerical results demonstrate that our method performs better in computing time compared with the CS-MWRK and MWRKO methods.展开更多
The overuse of and heavy dependency on a technology will result in the rigidity of thinking, which is true of computer-aided drawing. Due to the similarities in computer graphics, freehand sketching has attracted the ...The overuse of and heavy dependency on a technology will result in the rigidity of thinking, which is true of computer-aided drawing. Due to the similarities in computer graphics, freehand sketching has attracted the public attention again. In this paper, the necessity and importance of freehand sketching were reaffirmed, and suggestions for teaching reform in terms of learning interest, methods, quantity, and achievements were put forward, so as to help students to comprehensively improve their skills and accomplishment in their learning and practice.展开更多
A new 20 kV high voltage system has been designed,developed and operated in CSRm cooler[1],in order to satisfy requirements of pulsed electron cooling experiments[2].Series of FuG high voltage power supplies were used...A new 20 kV high voltage system has been designed,developed and operated in CSRm cooler[1],in order to satisfy requirements of pulsed electron cooling experiments[2].Series of FuG high voltage power supplies were used,including a 20 kV main power supply,two 3.5 kV DC power supplies for the anode and suppressor,a3.5 kV power supply for the grid,a 3.5 kV power supply with the maximum current of 3.0 A for the collector and a 20 V power supply for the filament.The sketch of the power supply system is shown in Fig.1 and the main parameters of all power supplies are listed in Table 1.The residual ripple of the main power supply is around 105(max.p-p value).A LAN interface was built in the main power supply,and other modules were communicated with the main power supply by optical fiber.A interlock system was used for the grid and anode power supplies,therefore the extracted electron beam can be cutoff quickly(<10 ms)while the leakage current of the main power supply is over threshold.展开更多
在高速网络环境中,超级传播者被界定为那些具有大量连接的主机或设备。准确的超级传播者检测在网络监控、安全分析及流量管理等多种应用中起着至关重要的作用。基于Sketch的可逆算法因具有卓越的内存效率与从内部结构中恢复超级传播者I...在高速网络环境中,超级传播者被界定为那些具有大量连接的主机或设备。准确的超级传播者检测在网络监控、安全分析及流量管理等多种应用中起着至关重要的作用。基于Sketch的可逆算法因具有卓越的内存效率与从内部结构中恢复超级传播者ID的能力,受到了广泛关注。根据应用需要,通常将同一台主机或设备发出或接收的所有数据包抽象为一条流。在高速网络中,流的分布通常高度偏斜,仅有少部分流为大流,绝大多数是小流。然而,现有研究的内存结构设计无法高效地适应高度偏斜的流分布,使得内存资源利用率较为低下。为此,设计了一种基于自适应采样的超级传播者检测算法AS-SSD(Adaptive Sampling Based Super Spreader Detection),该算法通过一种基于寄存器共享的自适应采样策略,弥补了上述不足。AS-SSD首先将到达的流元素映射到一个寄存器数组中,使得小流仅使用少量寄存器,而越大的流使用越多的寄存器,从而适应偏斜的流分布;接着,将所有流的元素映射到一个寄存器数组中,使得小流仅使用少量寄存器,大流使用更多的寄存器,从而适应偏斜的流分布;然后,利用自适应采样策略动态调整不同规模流的元素采样概率,在保证精度的前提下,减少大流对寄存器的占用,进一步提升内存资源的利用效率。实验评估显示,AS-SSD在维持高吞吐量的同时,在超级传播者检测任务中展现出了更高的检测准确度,相比目前最先进的算法,最高可以将F1值提高0.609以上。展开更多
With government support,more young people are studying Thangka art,securing its innovative development.THE 1,300-year-old Thangka art,religious painting on woven material,has been lauded as an illustrated encyclopedia...With government support,more young people are studying Thangka art,securing its innovative development.THE 1,300-year-old Thangka art,religious painting on woven material,has been lauded as an illustrated encyclopedia of Tibetan culture.Its unique artistic and cultural value earned it a place on China’s intangible cultural heritage list in 2006.One institution tasked with preserving and developing this ancient art is the Tibet Academy of Thangka(TAT)in Lhasa.It focuses on the Mansar School of Thangka painting.Visitors can observe the whole process of creating a Mansar Thangka piece,from sketching to adding the final touch.展开更多
Persistent flows are defined as network flows that persist over multiple time intervals and continue to exhibit activity over extended periods,which are critical for identifying long-term behaviors and subtle security...Persistent flows are defined as network flows that persist over multiple time intervals and continue to exhibit activity over extended periods,which are critical for identifying long-term behaviors and subtle security threats.Programmable switches provide line-rate packet processing to meet the requirements of high-speed network environments,yet they are fundamentally limited in computational and memory resources.Accurate and memoryefficient persistent flow detection on programmable switches is therefore essential.However,existing approaches often rely on fixed-window sketches or multiple sketches instances,which either suffer from insufficient temporal precision or incur substantial memory overhead,making them ineffective on programmable switches.To address these challenges,we propose SP-Sketch,an innovative sliding-window-based sketch that leverages a probabilistic update mechanism to emulate slot expiration without maintaining multiple sketch instances.This innovative design significantly reduces memory consumption while preserving high detection accuracy across multiple time intervals.We provide rigorous theoretical analyses of the estimation errors,deriving precise error bounds for the proposed method,and validate our approach through comprehensive implementations on both P4 hardware switches(with Intel Tofino ASIC)and software switches(i.e.,BMv2).Experimental evaluations using real-world traffic traces demonstrate that SP-Sketch outperforms traditional methods,improving accuracy by up to 20%over baseline sliding window approaches and enhancing recall by 5%compared to non-sliding alternatives.Furthermore,SP-Sketch achieves a significant reduction in memory utilization,reducing memory consumption by up to 65%compared to traditional methods,while maintaining a robust capability to accurately track persistent flow behavior over extended time periods.展开更多
文摘Motivated by the count sketch maximal weighted residual Kaczmarz (CS-MWRK) method presented by Zhang and Li (Appl. Math. Comput., 410, 126486), we combine the count sketch tech with the maximal weighted residual Kaczmarz Method with Oblique Projection (MWRKO) constructed by Wang, Li, Bao and Liu (arXiv: 2106.13606) to develop a new method for solving highly overdetermined linear systems. The convergence rate of the new method is analyzed. Numerical results demonstrate that our method performs better in computing time compared with the CS-MWRK and MWRKO methods.
文摘The overuse of and heavy dependency on a technology will result in the rigidity of thinking, which is true of computer-aided drawing. Due to the similarities in computer graphics, freehand sketching has attracted the public attention again. In this paper, the necessity and importance of freehand sketching were reaffirmed, and suggestions for teaching reform in terms of learning interest, methods, quantity, and achievements were put forward, so as to help students to comprehensively improve their skills and accomplishment in their learning and practice.
基金National Natural Science foundation of China(11575264,11375245,11475235)Hundred Talents Project of CAS。
文摘A new 20 kV high voltage system has been designed,developed and operated in CSRm cooler[1],in order to satisfy requirements of pulsed electron cooling experiments[2].Series of FuG high voltage power supplies were used,including a 20 kV main power supply,two 3.5 kV DC power supplies for the anode and suppressor,a3.5 kV power supply for the grid,a 3.5 kV power supply with the maximum current of 3.0 A for the collector and a 20 V power supply for the filament.The sketch of the power supply system is shown in Fig.1 and the main parameters of all power supplies are listed in Table 1.The residual ripple of the main power supply is around 105(max.p-p value).A LAN interface was built in the main power supply,and other modules were communicated with the main power supply by optical fiber.A interlock system was used for the grid and anode power supplies,therefore the extracted electron beam can be cutoff quickly(<10 ms)while the leakage current of the main power supply is over threshold.
文摘在高速网络环境中,超级传播者被界定为那些具有大量连接的主机或设备。准确的超级传播者检测在网络监控、安全分析及流量管理等多种应用中起着至关重要的作用。基于Sketch的可逆算法因具有卓越的内存效率与从内部结构中恢复超级传播者ID的能力,受到了广泛关注。根据应用需要,通常将同一台主机或设备发出或接收的所有数据包抽象为一条流。在高速网络中,流的分布通常高度偏斜,仅有少部分流为大流,绝大多数是小流。然而,现有研究的内存结构设计无法高效地适应高度偏斜的流分布,使得内存资源利用率较为低下。为此,设计了一种基于自适应采样的超级传播者检测算法AS-SSD(Adaptive Sampling Based Super Spreader Detection),该算法通过一种基于寄存器共享的自适应采样策略,弥补了上述不足。AS-SSD首先将到达的流元素映射到一个寄存器数组中,使得小流仅使用少量寄存器,而越大的流使用越多的寄存器,从而适应偏斜的流分布;接着,将所有流的元素映射到一个寄存器数组中,使得小流仅使用少量寄存器,大流使用更多的寄存器,从而适应偏斜的流分布;然后,利用自适应采样策略动态调整不同规模流的元素采样概率,在保证精度的前提下,减少大流对寄存器的占用,进一步提升内存资源的利用效率。实验评估显示,AS-SSD在维持高吞吐量的同时,在超级传播者检测任务中展现出了更高的检测准确度,相比目前最先进的算法,最高可以将F1值提高0.609以上。
文摘With government support,more young people are studying Thangka art,securing its innovative development.THE 1,300-year-old Thangka art,religious painting on woven material,has been lauded as an illustrated encyclopedia of Tibetan culture.Its unique artistic and cultural value earned it a place on China’s intangible cultural heritage list in 2006.One institution tasked with preserving and developing this ancient art is the Tibet Academy of Thangka(TAT)in Lhasa.It focuses on the Mansar School of Thangka painting.Visitors can observe the whole process of creating a Mansar Thangka piece,from sketching to adding the final touch.
基金supported by the National Undergraduate Innovation and Entrepreneurship Training Program of China(Project No.202510559076)at Jinan University,a nationwide initiative administered by the Ministry of Educationthe National Natural Science Foundation of China(NSFC)under Grant No.62172189.
文摘Persistent flows are defined as network flows that persist over multiple time intervals and continue to exhibit activity over extended periods,which are critical for identifying long-term behaviors and subtle security threats.Programmable switches provide line-rate packet processing to meet the requirements of high-speed network environments,yet they are fundamentally limited in computational and memory resources.Accurate and memoryefficient persistent flow detection on programmable switches is therefore essential.However,existing approaches often rely on fixed-window sketches or multiple sketches instances,which either suffer from insufficient temporal precision or incur substantial memory overhead,making them ineffective on programmable switches.To address these challenges,we propose SP-Sketch,an innovative sliding-window-based sketch that leverages a probabilistic update mechanism to emulate slot expiration without maintaining multiple sketch instances.This innovative design significantly reduces memory consumption while preserving high detection accuracy across multiple time intervals.We provide rigorous theoretical analyses of the estimation errors,deriving precise error bounds for the proposed method,and validate our approach through comprehensive implementations on both P4 hardware switches(with Intel Tofino ASIC)and software switches(i.e.,BMv2).Experimental evaluations using real-world traffic traces demonstrate that SP-Sketch outperforms traditional methods,improving accuracy by up to 20%over baseline sliding window approaches and enhancing recall by 5%compared to non-sliding alternatives.Furthermore,SP-Sketch achieves a significant reduction in memory utilization,reducing memory consumption by up to 65%compared to traditional methods,while maintaining a robust capability to accurately track persistent flow behavior over extended time periods.
