The theory of tune feedback correction and the principle of a feedback algorithm based on machine learning are introduced,with a focus on the application of lasso regression for tune feedback correction.Simulation ver...The theory of tune feedback correction and the principle of a feedback algorithm based on machine learning are introduced,with a focus on the application of lasso regression for tune feedback correction.Simulation verification and online feedback correction results are presented.The results show that,after applying machine learning,the feedback accuracy of the tune feedback system was higher,and the betatron tune stability was further improved.展开更多
Iterative feedback tuning is an attractive method for industry as it is a model free approach using experiments conducted on the plant to tune controller parameters. Classically Gauss-Newton iterative methods are used...Iterative feedback tuning is an attractive method for industry as it is a model free approach using experiments conducted on the plant to tune controller parameters. Classically Gauss-Newton iterative methods are used in IFT to update the controller parameters in the negative gradient direction of a specified design criterion function. Levenburg-Marquardt and Trust-Region strategies offer attractive advantages to Gauss-Newton in many applications,these alternative methods are given and results from simulation presented. A discussion on the differences between line search methods and Trust-Region methods is given showing the Trust-Region search direction is more flexible. Step size selection is often the limiting factor and it is found that with unknown step size values and initial controller parameters the Trust-Region is the best selection,where as if overshoot is a concern Levenburg-Marquardt is a good choice.Gauss-Newton method provides quick convergence and a fast response time however it shows more dependence on the step size.展开更多
This paper investigates the intensity tuning characteristics of a double longitudinal modes HeiNe laser subjected to optical feedback. The intensity undulations of the total light and the two modes are observed for di...This paper investigates the intensity tuning characteristics of a double longitudinal modes HeiNe laser subjected to optical feedback. The intensity undulations of the total light and the two modes are observed for different external cavity length. Two modulations of the internal cavity length are performed. One is only for the internal cavity length being modulated and the other is for both the internal and the external cavity length being modulated. The undulation frequency of the total light is found to be determined by the ratio of external cavity length to internal cavity length in both modulations. When the external cavity length is integral times of the internal cavity length, the fringe frequency of the total light could be seven or even more times of that in conventional optical feedback. A simple theoretical analysis is presented, which is in good agreement with the experimental results. The potential use of the experimental results is also discussed.展开更多
This paper demonstrates wide-band CMOS VCO based on the transformer feedback from traditional circuit to our proposed work. The start up condition of the traditional cross-coupled pair is expressed by the high frequen...This paper demonstrates wide-band CMOS VCO based on the transformer feedback from traditional circuit to our proposed work. The start up condition of the traditional cross-coupled pair is expressed by the high frequency model. The wide band technique of this structure is derived with the help of the high frequency model of the transistor. Therefore, the wide band CMOS VCO based on the common source transformer feedback topology can achieves the high performance in the low voltage and low phase noise. The measurement result of the VCO exhibits the figure of merit, core power consumption and output power at supply voltage 0.8 V are –193.1 dBc/Hz, 4.4 mW and –2.3 dBm, respectively. The phase noise is –124.3 dBc/Hz at 1 MHz offset under the operation frequency 5.8 GHz. And the tuning range of the circuit can obtain 28%, this VCO is fabricated in TSMC 0.18 μm 1P6MCMOS process.展开更多
专利作为创新技术的重要知识载体,文本相似性计算是自然语言处理应用广泛的重要一环,专利文本相似性计算有助于挖掘潜在价值专利和支撑专利检索。本文提出了一种基于专家反馈微调的专利文本相似性计算方法,在专家评价小数据集上,利用大...专利作为创新技术的重要知识载体,文本相似性计算是自然语言处理应用广泛的重要一环,专利文本相似性计算有助于挖掘潜在价值专利和支撑专利检索。本文提出了一种基于专家反馈微调的专利文本相似性计算方法,在专家评价小数据集上,利用大模型重新生成摘要文本进而实现负例文本增强,随后利用专家评价数据集对预训练模型进行微调,并在大规模数据集上重新计算得到相似专利。本文在新材料和电子信息两个新兴领域中分别继续训练BART (bidirectional and auto-regressive transformers)和BGE (Beijing Academy of Artificial Intelligence general embedding)模型,并在专家评价数据集上微调两个模型。实验结果表明,该方法的Spearman相关系数相较于初始模型分别提升了6.4%和16.9%。实证部分识别了电子信息领域企业技术竞争对手这一场景,验证了该方法在技术竞争对手识别中的优势。展开更多
基金supported by the National Natural Science Foundation of China (No. 11975227)Hefei Science Center,CAS (No.2019HSC-KPRD003)
文摘The theory of tune feedback correction and the principle of a feedback algorithm based on machine learning are introduced,with a focus on the application of lasso regression for tune feedback correction.Simulation verification and online feedback correction results are presented.The results show that,after applying machine learning,the feedback accuracy of the tune feedback system was higher,and the betatron tune stability was further improved.
文摘Iterative feedback tuning is an attractive method for industry as it is a model free approach using experiments conducted on the plant to tune controller parameters. Classically Gauss-Newton iterative methods are used in IFT to update the controller parameters in the negative gradient direction of a specified design criterion function. Levenburg-Marquardt and Trust-Region strategies offer attractive advantages to Gauss-Newton in many applications,these alternative methods are given and results from simulation presented. A discussion on the differences between line search methods and Trust-Region methods is given showing the Trust-Region search direction is more flexible. Step size selection is often the limiting factor and it is found that with unknown step size values and initial controller parameters the Trust-Region is the best selection,where as if overshoot is a concern Levenburg-Marquardt is a good choice.Gauss-Newton method provides quick convergence and a fast response time however it shows more dependence on the step size.
基金Project supported by the Major Program of the National Natural Science Foundation of China （Grant No 60438010）.
文摘This paper investigates the intensity tuning characteristics of a double longitudinal modes HeiNe laser subjected to optical feedback. The intensity undulations of the total light and the two modes are observed for different external cavity length. Two modulations of the internal cavity length are performed. One is only for the internal cavity length being modulated and the other is for both the internal and the external cavity length being modulated. The undulation frequency of the total light is found to be determined by the ratio of external cavity length to internal cavity length in both modulations. When the external cavity length is integral times of the internal cavity length, the fringe frequency of the total light could be seven or even more times of that in conventional optical feedback. A simple theoretical analysis is presented, which is in good agreement with the experimental results. The potential use of the experimental results is also discussed.
文摘This paper demonstrates wide-band CMOS VCO based on the transformer feedback from traditional circuit to our proposed work. The start up condition of the traditional cross-coupled pair is expressed by the high frequency model. The wide band technique of this structure is derived with the help of the high frequency model of the transistor. Therefore, the wide band CMOS VCO based on the common source transformer feedback topology can achieves the high performance in the low voltage and low phase noise. The measurement result of the VCO exhibits the figure of merit, core power consumption and output power at supply voltage 0.8 V are –193.1 dBc/Hz, 4.4 mW and –2.3 dBm, respectively. The phase noise is –124.3 dBc/Hz at 1 MHz offset under the operation frequency 5.8 GHz. And the tuning range of the circuit can obtain 28%, this VCO is fabricated in TSMC 0.18 μm 1P6MCMOS process.
文摘专利作为创新技术的重要知识载体,文本相似性计算是自然语言处理应用广泛的重要一环,专利文本相似性计算有助于挖掘潜在价值专利和支撑专利检索。本文提出了一种基于专家反馈微调的专利文本相似性计算方法,在专家评价小数据集上,利用大模型重新生成摘要文本进而实现负例文本增强,随后利用专家评价数据集对预训练模型进行微调,并在大规模数据集上重新计算得到相似专利。本文在新材料和电子信息两个新兴领域中分别继续训练BART (bidirectional and auto-regressive transformers)和BGE (Beijing Academy of Artificial Intelligence general embedding)模型,并在专家评价数据集上微调两个模型。实验结果表明,该方法的Spearman相关系数相较于初始模型分别提升了6.4%和16.9%。实证部分识别了电子信息领域企业技术竞争对手这一场景,验证了该方法在技术竞争对手识别中的优势。
