A novel near-infrared all-fiber mode monitor based on a mini-two-path Mach-Zehnder interferometer(MTP-MZI)is proposed.The MTP-MZI mode monitor is created by fusing a section of(no-core fiber,NCF)and a(single-mode fibe...A novel near-infrared all-fiber mode monitor based on a mini-two-path Mach-Zehnder interferometer(MTP-MZI)is proposed.The MTP-MZI mode monitor is created by fusing a section of(no-core fiber,NCF)and a(single-mode fiber,SMF)together with an optical fiber fusion splicer,establishing two distinct centimeter-level optical transmission paths.Since the high-order modes in NCF transmit near-infrared light more sensitively to curvature-induced energy leakage than the fundamental mode in SMF,the near-infrared high-order mode light leaks out of NCF when the curvature changes,causing the MTP-MZI transmission spectrum to change.By ana⁃lyzing the relationship between the curvature,transmission spectrum,and spatial frequency spectrum,the modes involved in the interference can be studied,thereby revealing the mode transmission characteristics of near-infra⁃red light in optical fibers.In the verification experiments,higher-order modes were excited by inserting a novel hollow-core fiber(HCF)into the MTP-MZI.When the curvature of the MTP-MZI changes,the near-infrared light high-order mode introduced into the device leaks out,causing the transmission spectrum to return to its origi⁃nal state before bending and before the HCF was spliced.The experimental results demonstrate that the MTP-MZI mode monitor can monitor the fiber modes introduced from the external environment,providing both theoretical and experimental foundations for near-infrared all-fiber mode monitoring in optical information systems.展开更多
We study the fringe visibility and the which-path information(WPI) of a general Mach-Zehnder interferometer with an asymmetric beam splitter(BS). A minimum error measurement in the detector is used to extract the WPI....We study the fringe visibility and the which-path information(WPI) of a general Mach-Zehnder interferometer with an asymmetric beam splitter(BS). A minimum error measurement in the detector is used to extract the WPI. Both the fringe visibility V and the WPI I_(path) are affected by the initial state of the photon and the second asymmetric BS. The condition in which the WPI takes the maximum is obtained. The complementarity relationship V^2 + I_(path)~2 ≤ 1 is found, and the conditions for equality are also presented.展开更多
Turner syndrome(TS)is a chromosomal disorder disease that only affects the growth of female patients.Prompt diagnosis is of high significance for the patients.However,clinical screening methods are time-consuming and ...Turner syndrome(TS)is a chromosomal disorder disease that only affects the growth of female patients.Prompt diagnosis is of high significance for the patients.However,clinical screening methods are time-consuming and cost-expensive.Some researchers used machine learning-based methods to detect TS,the performance of which needed to be improved.Therefore,we propose an ensemble method of two-path capsule networks(CapsNets)for detecting TS based on global-local facial images.Specifically,the TS facial images are preprocessed and segmented into eight local parts under the direction of physicians;then,nine two-path CapsNets are respectively trained using the complete TS facial images and eight local images,in which the few-shot learning is utilized to solve the problem of limited data;finally,a probability-based ensemble method is exploited to combine nine classifiers for the classification of TS.By studying base classifiers,we find two meaningful facial areas are more related to TS patients,i.e.,the parts of eyes and nose.The results demonstrate that the proposed model is effective for the TS classification task,which achieves the highest accuracy of 0.9241.展开更多
合环转供电是提高供电可靠性的关键手段,但直接合环可能产生较大冲击电流影响电网运行安全性。采用旋转潮流控制器(rotary power flow controller,RPFC)的方式能够实现台区的零感知合环,但电压调节轨迹不当将会带来RPFC接入点的电压越...合环转供电是提高供电可靠性的关键手段,但直接合环可能产生较大冲击电流影响电网运行安全性。采用旋转潮流控制器(rotary power flow controller,RPFC)的方式能够实现台区的零感知合环,但电压调节轨迹不当将会带来RPFC接入点的电压越限问题。对此,提出一种基于两阶段最优路径的RPFC配电网柔性合环方法。首先,对输出电压运行轨迹进行合理规划,将其分为两阶段:第1阶段要求合环点两端电压相位一致并约束电压幅值相等,实现端电压的平稳过渡;第2阶段在相位一致的基础上,控制RPFC输出电压至目标值,使合环点两端电压幅值一致。然后,采用分相量夹角计算和旋转角协调控制,选择就近的旋转角设定值作为目标值,从而实现合环点两端电压无差调节;最后,仿真和实验对比分析所提方法将电压越限至少降低至30%,展示RPFC在实现配电网柔性合环中的重要应用价值。展开更多
基金Supported by the Central Government Guidance on Local Science and Technology Development Funds(2023ZY1023)the Six Talent Peaks Project in Jiangsu Province(KTHY-052).
文摘A novel near-infrared all-fiber mode monitor based on a mini-two-path Mach-Zehnder interferometer(MTP-MZI)is proposed.The MTP-MZI mode monitor is created by fusing a section of(no-core fiber,NCF)and a(single-mode fiber,SMF)together with an optical fiber fusion splicer,establishing two distinct centimeter-level optical transmission paths.Since the high-order modes in NCF transmit near-infrared light more sensitively to curvature-induced energy leakage than the fundamental mode in SMF,the near-infrared high-order mode light leaks out of NCF when the curvature changes,causing the MTP-MZI transmission spectrum to change.By ana⁃lyzing the relationship between the curvature,transmission spectrum,and spatial frequency spectrum,the modes involved in the interference can be studied,thereby revealing the mode transmission characteristics of near-infra⁃red light in optical fibers.In the verification experiments,higher-order modes were excited by inserting a novel hollow-core fiber(HCF)into the MTP-MZI.When the curvature of the MTP-MZI changes,the near-infrared light high-order mode introduced into the device leaks out,causing the transmission spectrum to return to its origi⁃nal state before bending and before the HCF was spliced.The experimental results demonstrate that the MTP-MZI mode monitor can monitor the fiber modes introduced from the external environment,providing both theoretical and experimental foundations for near-infrared all-fiber mode monitoring in optical information systems.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11434011 and 11575058
文摘We study the fringe visibility and the which-path information(WPI) of a general Mach-Zehnder interferometer with an asymmetric beam splitter(BS). A minimum error measurement in the detector is used to extract the WPI. Both the fringe visibility V and the WPI I_(path) are affected by the initial state of the photon and the second asymmetric BS. The condition in which the WPI takes the maximum is obtained. The complementarity relationship V^2 + I_(path)~2 ≤ 1 is found, and the conditions for equality are also presented.
基金the National Key R&D Program of China(No.2020YFB2104402)。
文摘Turner syndrome(TS)is a chromosomal disorder disease that only affects the growth of female patients.Prompt diagnosis is of high significance for the patients.However,clinical screening methods are time-consuming and cost-expensive.Some researchers used machine learning-based methods to detect TS,the performance of which needed to be improved.Therefore,we propose an ensemble method of two-path capsule networks(CapsNets)for detecting TS based on global-local facial images.Specifically,the TS facial images are preprocessed and segmented into eight local parts under the direction of physicians;then,nine two-path CapsNets are respectively trained using the complete TS facial images and eight local images,in which the few-shot learning is utilized to solve the problem of limited data;finally,a probability-based ensemble method is exploited to combine nine classifiers for the classification of TS.By studying base classifiers,we find two meaningful facial areas are more related to TS patients,i.e.,the parts of eyes and nose.The results demonstrate that the proposed model is effective for the TS classification task,which achieves the highest accuracy of 0.9241.
文摘目前,多无人机(Unmanned Aerial Vehicle,UAV)在大规模任务场景下的任务分配问题仍是一个挑战性问题。传统启发式算法可在较低计算复杂度下得到满意的解,但收敛速度慢且难以收敛到全局最优解。为此提出一种基于UAV链、任务链和双阶段修复策略的遗传算法(Genetic Algorithm Based on UAV-chain,Task-chain,and Two-Stage Repair strategy,UTTSRGA)。在编码结构中设计UAV链和任务链来量化任务执行代价,增强了编码中的信息承载能力并显著提升搜索效率。针对交叉操作后出现任务缺失与任务重复问题,设计双阶段修复策略。第一阶段设计随机填充机制,增强对解空间的全局搜索能力;第二阶段设计邻接映射表修复机制,根据任务间的邻接关系提供进化方向,有效引导种群向当前最优解快速收敛。提出动态复合变异策略,融合自适应变异率与基于任务链值的变异点选择,并设计4种功能互补的变异算子,多维度协同优化解的质量。针对大规模场景下的路径交叉问题,引入路径优化策略,从实践角度进一步优化任务分配方案。实验结果表明,UTTSRGA在不同任务规模下,尤其是大规模复杂任务场景中,在解的质量、收敛速度和鲁棒性3个方面均表现出显著优势。
文摘合环转供电是提高供电可靠性的关键手段,但直接合环可能产生较大冲击电流影响电网运行安全性。采用旋转潮流控制器(rotary power flow controller,RPFC)的方式能够实现台区的零感知合环,但电压调节轨迹不当将会带来RPFC接入点的电压越限问题。对此,提出一种基于两阶段最优路径的RPFC配电网柔性合环方法。首先,对输出电压运行轨迹进行合理规划,将其分为两阶段:第1阶段要求合环点两端电压相位一致并约束电压幅值相等,实现端电压的平稳过渡;第2阶段在相位一致的基础上,控制RPFC输出电压至目标值,使合环点两端电压幅值一致。然后,采用分相量夹角计算和旋转角协调控制,选择就近的旋转角设定值作为目标值,从而实现合环点两端电压无差调节;最后,仿真和实验对比分析所提方法将电压越限至少降低至30%,展示RPFC在实现配电网柔性合环中的重要应用价值。
