As the core component of inertial navigation systems, fiber optic gyroscope (FOG), with technical advantages such as low power consumption, long lifespan, fast startup speed, and flexible structural design, are widely...As the core component of inertial navigation systems, fiber optic gyroscope (FOG), with technical advantages such as low power consumption, long lifespan, fast startup speed, and flexible structural design, are widely used in aerospace, unmanned driving, and other fields. However, due to the temper-ature sensitivity of optical devices, the influence of environmen-tal temperature causes errors in FOG, thereby greatly limiting their output accuracy. This work researches on machine-learn-ing based temperature error compensation techniques for FOG. Specifically, it focuses on compensating for the bias errors gen-erated in the fiber ring due to the Shupe effect. This work pro-poses a composite model based on k-means clustering, sup-port vector regression, and particle swarm optimization algo-rithms. And it significantly reduced redundancy within the sam-ples by adopting the interval sequence sample. Moreover, met-rics such as root mean square error (RMSE), mean absolute error (MAE), bias stability, and Allan variance, are selected to evaluate the model’s performance and compensation effective-ness. This work effectively enhances the consistency between data and models across different temperature ranges and tem-perature gradients, improving the bias stability of the FOG from 0.022 °/h to 0.006 °/h. Compared to the existing methods utiliz-ing a single machine learning model, the proposed method increases the bias stability of the compensated FOG from 57.11% to 71.98%, and enhances the suppression of rate ramp noise coefficient from 2.29% to 14.83%. This work improves the accuracy of FOG after compensation, providing theoretical guid-ance and technical references for sensors error compensation work in other fields.展开更多
The quantum entangled photon-pair source,as an essential component of optical quantum systems,holds great potential for applications such as quantum teleportation,quan-tum computing,and quantum imaging.The current wor...The quantum entangled photon-pair source,as an essential component of optical quantum systems,holds great potential for applications such as quantum teleportation,quan-tum computing,and quantum imaging.The current workhorse technique for preparing photon pairs involves performing spon-taneous parametric down conversion(SPDC)in bulk nonlinear crystals.However,the current power consumption and cost of preparing entangled photon-pair sources are relatively high,pos-ing challenges to their integration and scalability.In this paper,we propose a low-power system model for the quantum entan-gled photon-pair source based on SPDC theory and phase matching technology.This model allows us to analyze the per-formance of each module and the influence of component cha-racteristics on the overall system.In our experimental setup,we utilize a 5 mW laser diode and a typical type-II barium metabo-rate(BBO)crystal to prepare an entangled photon-pair source.The experimental results are in excellent agreement with the model,indicating a significant step towards achieving the goal of low-power and low-cost entangled photon-pair sources.This achievement not only contributes to the practical application of quantum entanglement lighting,but also paves the way for the widespread adoption of optical quantum systems in the future.展开更多
目的探讨脊柱侧弯矫形术患儿围手术期低体温的相关因素。方法以2019年1月至2020年1月于首都医科大学附属北京儿童医院接受手术治疗的脊柱畸形患儿为研究对象。根据围手术期是否发生低体温,分为低体温组(n=147)和正常体温组(n=53)。比较...目的探讨脊柱侧弯矫形术患儿围手术期低体温的相关因素。方法以2019年1月至2020年1月于首都医科大学附属北京儿童医院接受手术治疗的脊柱畸形患儿为研究对象。根据围手术期是否发生低体温,分为低体温组(n=147)和正常体温组(n=53)。比较两组患儿临床特征,采用多因素Logistic回归分析患儿围手术期发生低体温的危险因素。结果共实施脊柱侧弯矫形术200例,其中147例(147/200,73.5%)发生低体温。低体温组中,男64例,女83例,年龄6(3,12)岁;正常体温组中,男30例,女23例,年龄6(3,11)岁。两组患儿年龄、性别、体重、身高、身体质量指数(body mass index,BMI)、脊柱侧弯类型、麻醉时间、手术时间以及手术节段数目比较,差异均无统计学意义(P>0.05);而两组患儿输注异体血、单位输液量、基线体温差异具有统计学意义(P<0.05)。多因素Logistic回归分析结果显示,单位输液量大(OR=1.070,95%CI:1.010~1.133)、手术节段多(OR=1.117,95%CI:1.018~1.227)是导致低体温的独立危险因素;高基线体温(OR=0.064,95%CI:0.021~0.199)是预防低体温发生的独立保护因素。结论脊柱侧弯矫形手术中,输注液体多、手术节段多的患儿低体温的发生风险更高,维持高的基线体温有助于减少低体温的发生。展开更多
基金supported by the National Natural Science Foundation of China(62375013).
文摘As the core component of inertial navigation systems, fiber optic gyroscope (FOG), with technical advantages such as low power consumption, long lifespan, fast startup speed, and flexible structural design, are widely used in aerospace, unmanned driving, and other fields. However, due to the temper-ature sensitivity of optical devices, the influence of environmen-tal temperature causes errors in FOG, thereby greatly limiting their output accuracy. This work researches on machine-learn-ing based temperature error compensation techniques for FOG. Specifically, it focuses on compensating for the bias errors gen-erated in the fiber ring due to the Shupe effect. This work pro-poses a composite model based on k-means clustering, sup-port vector regression, and particle swarm optimization algo-rithms. And it significantly reduced redundancy within the sam-ples by adopting the interval sequence sample. Moreover, met-rics such as root mean square error (RMSE), mean absolute error (MAE), bias stability, and Allan variance, are selected to evaluate the model’s performance and compensation effective-ness. This work effectively enhances the consistency between data and models across different temperature ranges and tem-perature gradients, improving the bias stability of the FOG from 0.022 °/h to 0.006 °/h. Compared to the existing methods utiliz-ing a single machine learning model, the proposed method increases the bias stability of the compensated FOG from 57.11% to 71.98%, and enhances the suppression of rate ramp noise coefficient from 2.29% to 14.83%. This work improves the accuracy of FOG after compensation, providing theoretical guid-ance and technical references for sensors error compensation work in other fields.
文摘The quantum entangled photon-pair source,as an essential component of optical quantum systems,holds great potential for applications such as quantum teleportation,quan-tum computing,and quantum imaging.The current workhorse technique for preparing photon pairs involves performing spon-taneous parametric down conversion(SPDC)in bulk nonlinear crystals.However,the current power consumption and cost of preparing entangled photon-pair sources are relatively high,pos-ing challenges to their integration and scalability.In this paper,we propose a low-power system model for the quantum entan-gled photon-pair source based on SPDC theory and phase matching technology.This model allows us to analyze the per-formance of each module and the influence of component cha-racteristics on the overall system.In our experimental setup,we utilize a 5 mW laser diode and a typical type-II barium metabo-rate(BBO)crystal to prepare an entangled photon-pair source.The experimental results are in excellent agreement with the model,indicating a significant step towards achieving the goal of low-power and low-cost entangled photon-pair sources.This achievement not only contributes to the practical application of quantum entanglement lighting,but also paves the way for the widespread adoption of optical quantum systems in the future.
文摘目的初步探讨儿童丙泊酚闭环靶控输注技术(closed-loop target-controlled infusion technology,CL-TCI)充分麻醉时间比[bispectral index(40~60)%,BIS(40~60)%]的影响因素,对可能出现低BIS(40~60)%的患者采取更严密的监测,确保丙泊酚CL-TCI技术的安全使用。方法以首都医科大学附属北京儿童医院择期行非颅脑全麻手术患者152例(有效样本量136例)为研究对象,年龄12~216个月,美国医师协会麻醉分级(American Society of Anesthesiologists,ASA)Ⅰ~Ⅳ级。予以丙泊酚TCI(paedfusor模型)2~4μg/mL、芬太尼2μg/kg静脉输注以及罗库溴铵1 mg/kg静脉推注诱导。当BIS数值低于60并维持30 s时认为诱导结束。根据目标血压调整瑞芬太尼用量,手术完毕时停药。记录维持期BIS(40~60)%以及患者性别、体温、月龄、身体质量指数(body mass index,BMI)、ASA分级、麻醉时间、出血量。结果ASA分级和月龄是BIS(40~60)%的影响因素,其中以ASA分级影响最为显著,回归方程为Y=71.72+0.15×月龄-6.82×ASA,R 2=0.53。月龄决策树中,年龄拆分值为17个月。结论丙泊酚CL-TCI技术中,术前ASA分级及低龄是导致BIS(40~60)%降低的危险因素,其中ASA分级对BIS(40~60)%影响更大。对于ASAⅢ级以上或17月龄以下的患者,应加强术中镇静深度的观察与调控。
文摘目的探讨脊柱侧弯矫形术患儿围手术期低体温的相关因素。方法以2019年1月至2020年1月于首都医科大学附属北京儿童医院接受手术治疗的脊柱畸形患儿为研究对象。根据围手术期是否发生低体温,分为低体温组(n=147)和正常体温组(n=53)。比较两组患儿临床特征,采用多因素Logistic回归分析患儿围手术期发生低体温的危险因素。结果共实施脊柱侧弯矫形术200例,其中147例(147/200,73.5%)发生低体温。低体温组中,男64例,女83例,年龄6(3,12)岁;正常体温组中,男30例,女23例,年龄6(3,11)岁。两组患儿年龄、性别、体重、身高、身体质量指数(body mass index,BMI)、脊柱侧弯类型、麻醉时间、手术时间以及手术节段数目比较,差异均无统计学意义(P>0.05);而两组患儿输注异体血、单位输液量、基线体温差异具有统计学意义(P<0.05)。多因素Logistic回归分析结果显示,单位输液量大(OR=1.070,95%CI:1.010~1.133)、手术节段多(OR=1.117,95%CI:1.018~1.227)是导致低体温的独立危险因素;高基线体温(OR=0.064,95%CI:0.021~0.199)是预防低体温发生的独立保护因素。结论脊柱侧弯矫形手术中,输注液体多、手术节段多的患儿低体温的发生风险更高,维持高的基线体温有助于减少低体温的发生。
