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关键词： 甲状腺癌   甲状腺结节   超声检查   钙化  

摘要： 目的:分析超声检测甲状腺结节钙化对甲状腺癌的临床诊断价值。方法:选取2022年6月—2024年4月邳州市人民医院收治的甲状腺结节患者68例,均行超声检查,以病理检查为金标准,全面分析超声的临床检测价值。结果:68例甲状腺结节患者经病理检查显示,良性39例(57.35%),恶性29例(42.65%);超声检查良性37例(94.87%),恶性26例(89.66%);超声检查的灵敏度为89.66%,特异度为94.87%,准确率为92.65%;恶性结节中钙化结节占比高于良性结节,差异有统计学意义(P<0.05);恶性钙化结节的边界清晰、微钙化、单发结节占比高于良性钙化结节,差异有统计学意义(P<0.05)。结论:超声检测甲状腺结节钙化对甲状腺癌的诊断,具有重要的临床应用前景,通过分析甲状腺结节的钙化特征,能够更准确地评估结节的良恶性,为临床医生制定更合理的治疗方案,可提供重要参考。

关键词： 激光雷达   卷积神经网络(CNN)   光信号处理   雾中检测   联合注意力机制网络(CAMN)  

摘要： 自动驾驶汽车和移动机器人均依靠激光雷达等传感器技术的快速发展而进入实际应用过程,但是激光雷达在云雾环境下测距精度和探测范围差,限制了其全天候的应用。本文根据激光在雾中的传播和后向散射模型,建立了雾中目标回波信号的模型,同时提出了一种基于卷积神经网络(convolutional neural network,CNN)的联合注意力机制网络(combined attention mechanism network,CAMN),用于实现雾中目标回波信号的检测。仿真和实验结果表明,CAMN网络可以有效消除雾气对脉冲激光信号检测的干扰。在30%的散射率下,在10 m范围内检测的绝对误差平均值达到3.13 cm。激光雷达系统探测范围可以达到42 m,是其他方法探测范围的两三倍。该方法能有效提高雾天激光雷达测距精度和探测范围,为激光雷达的实际应用奠定基础。

关键词： 光纤感知参数   长距离   管道清管器   自动化运行   实时监测   信号分类器  

摘要： 为解决长距离管道清管器作业时,若出现卡堵状态未能及时发现定位,导致管道不能正常输送这一问题,设计基于光纤感知参数的长距离管道清管器自动化运行实时监测系统。考虑清管器卡堵时,卡堵振动信号主要作用于管道光缆光纤上,为此,系统利用长距离管道同沟铺设的通信光缆,组建光纤振动感知网络。由光源模块对管道光缆光纤持续输入光脉冲,并使用光电探测器接收返回的光纤感知信号,将光纤感知的光信号变成电信号模式发送至PC端。使用基于PNN的清管器光纤振动信号分类器,由基于光纤感知参数的清管器定位方法,结合此信号从光源模块发射、被光电探测器接收的时间差参数,运算振动的清管器位置。实验中,该系统可实时跟踪清管器的位置,及时掌握清管器的运行状态,监测位置与实际位置仅存在0.01 m的偏差。

关键词： 煤矿井下   供电系统   在线检测系统   设计研究  

摘要： 供电系统电能质量问题可能造成谐波污染、电压波形畸变等,从而影响煤矿井下设备的可靠稳定运行,严重时甚至危及安全生产。在这种背景下,基于STM32 CPU与RTOS控制器,设计了一套高效、实用的电能质量在线检测系统。该系统可以实时、准确地采集、处理与分析电能质量数据,涵盖电流、电压、谐波等参数,还实现了波形捕捉、事件记录等功能。经实验验证,该系统具备一定的实用性与准确性,能够有效提升煤矿井下电网质量,为提高煤矿生产效率与推动煤矿智能化进程提供有力的技术支撑。

关键词： 无线传感器网络   烟花算法   覆盖率   感知模型  

摘要： 为优化无线传感器网络覆盖范围,提出了一种基于改进烟花算法的无线传感器网络覆盖优化策略。首先,通过概率感知模型和目标函数建立了网络覆盖策略。其次,引入拉丁超立方抽样方法和多重扰动对传统烟花算法进行改进,避免算法进行局部最优和过早收敛。最后,为验证所提算法的优化性能,与常规优化算法进行了对比。实验结果表明:所提算法能有效逃离局部最优,在三种不同场景下,网络覆盖率分别达到了94.82%、98.23%和96.59%,其性能明显优于其他对比算法。

关键词： Landslides   Urban resilience   CCD   Spatial-temporal evolution   DISASTER RESILIENCE   SUSCEPTIBILITY  

摘要： Cities, as complex systems with multi-interconnected subsystems, face significant challenges from both rapid urbanization and climate change. Ensuring high resilience in urban areas is essential for managing these dynamic risks effectively. This study introduces an innovative, data-driven approach to quantitatively analyze the spatialtemporal evolution patterns of urban resilience, validated through a case study of Chongqing, a representative mountainous city in China. Based on historical landslide data from Chongqing (2010-2020), which includes 4464 events, along with indicator data from the Chongqing Statistical Yearbook, we developed a comprehensive assessment framework. This framework incorporates 33 variables, covering indicators of physical-environmental resilience (PER) and socio-economic resilience (SER). The model integrates the Random Forest (RF) algorithm, Analytic Hierarchy Process (AHP), and Coupling Coordination Degree (CCD) model. Key findings include: (1) Social development in mountainous cities like Chongqing follows a point-to-area pattern. Although there is an overall increase in SER, the CCD in more developed areas (Chongqing urban circle) was generally higher than in less developed areas (northeastern and southeastern Chongqing) (2) The PER model demonstrated exceptional performance (AUC values consistently above 0.95). Spatiotemporal evolution models reveal that Chongqing maintains a high overall PER. Notably, from 2019 to 2020, the proportion of administrative units classified as highly resilient peaked at 24.5%, marking a historical high. (3) Multi-year average rainfall primarily impacts PER (ranked first), while Gross Domestic Product (GDP) significantly affect SER. The development of multidimensional recovery indicators provides a robust framework for assessing resilience against landslides in mountainous cities. The CCD model illustrates the importance of regional dynamic coordinated development in resilience trajectories. This study provi

关键词： Charge Transfer Inefficiency   CTI correction   Detectors   CCD   Radiation damage   Space radiation   Pyxel   Software   MODEL  

摘要： Pyxel is a powerful end-to-end detector simulations framework with the aim of being reusable, reliable and help facilitate knowledge transfer between a wide range of related fields. To show how beneficial Pyxel can be, we present an investigation into the effect of Charge Transfer Inefficiency (CTI) on an irradiated CCD273 device produced by Teledyne-e2v, the type of detector used for the Euclid VIS instrument. This requires production of two pipelines. Firstly, a calibration pipeline to search the parameter space and obtain best fitting trap parameters based upon the CTI within the detector. Secondly, a correction pipeline which aims to correct the CTI-induced data using these trap parameters to obtain a nominal efficiency of 99.5%. The following presents work conducted in building, testing and validating the correction pipeline using Pyxel and the CTI model ArCTIC. This involves data from the unirradiated portion of a CCD-273 device using the scene projection system at the labs at the European Space Agency (ESA). The images are computationally altered by varying parameters such as background levels and readout noise, and by synthetically producing CTI trails from known trap parameters. The resulting images are corrected and analysed to understand how noise affects the correction efficiency at varying image background levels.

关键词： CCD imagery   3D reconstruction   Multi-view stereo   Rational function model   Rational polynomial coefficients   Image geometric correction  

摘要： Automatic 3D reconstruction from spaceborne charge-coupled device (CCD) optical imagery is still a challenge as the rational functional model (RFM) based reconstruction pipeline failed to amount to the advances of pinhole based approaches in computer vision and photogrammetry. As a consequence, the accuracy and completeness of the reconstructed surface by RFM based pipeline improved slightly recent years. Though the perspective camera approximation model was explored to convert the RFM to pinhole model, it could hardly guarantee the reconstruction accuracy due to the re-projection error introduced when approximating the linear push broom camera to perspective camera. Hence, we present a refined equivalent pinhole model (REPM) for 3D reconstruction from spaceborne CCD imagery. We initially investigated the aspects that influence the re-projection error thru mathematical induction and discovered that the image size and height range of the captured area are the two key factors. To ensure the performance of the 3D reconstruction while minimizing the re-projection error, we explored the optimal image size to crop large-scale image with, while alleviated the height range effect on the image space by re-projecting the cropped images to be closed to the pseudo- image that is captured by the approximated perspective camera. The above-mentioned improvements are implemented in an image partition module and an image geometric correction module respectively, and are encompassed in the proposed REPM-based 3D reconstruction pipeline. We conducted extensive experiments on different images covering various areas from different linear-array CCD sensors to verify the proposed approach. The results indicate that our pipeline can achieve higher accuracy and completeness and exhibits great potential. The implementation of the pipeline is available at here.

关键词： Sintering pressure   Leach rate   Polycrystalline diamond   TOOL  

摘要： The effect of sintering pressure on the microstructure, wear resistance and leachability of polycrystalline diamond (PDC) was studied using central composite design (CCD) modelling. Pressure and leachability had an inverse relationship due to reduced cobalt pool size and increased diamond contiguity with higher pressures. Xray diffraction and X-ray fluorescence confirmed the selective removal of cobalt during leaching. The relationship between pressure and leachability was modelled as linear: Y =- 1.047x + 11.139, valid within the 5-7 GPa pressure range. For a fixed temperature of 1600 degrees C, the optimum leach rate was 6.1 mu m/h at 5 GPa. This study provided insights into optimizing PDC design and leaching processes for improved performance.

关键词： 光纤水听器   遥泵放大   无中继传输  

摘要： 针对远程大规模光纤水听器系统，分布式光纤喇曼放大器（DFRA）无法有效补偿阵列损耗和传输链路损耗，且高增益放大时存在较强的泵浦光相对强度噪声问题，提出遥泵放大（ROPA）与DFRA相结合的混合放大技术方案，通过建立系统光信噪比（OSNR）与解调相位噪声的关联模型，分析了ROPA对系统OSNR以及解调相位噪声的影响。实验结果表明：在16波长×8时分复用的100km远程PGC解调系统中，ROPA的运用使系统解调相位噪声降低了7.7 dB，达到-100.4 dB@1 kHz；对遥泵增益单元（RGU）光路结构进行优化后，系统解调相位噪声达到-101.5 dB@1 kHz。