Shengjun Zhang

The invention proposes a geotechnical sample image acquisition device, relating to the technical field of image acquisition equipment. It includes a shooting tent and a base, with the top of the base rotatably connected to a rotating chassis. The shooting tent includes a sliding cover and a fixed cover arranged oppositely, forming a closed display space with the top surface of the base. The fixed cover has a chamber accommodating the sliding cover, and the fixed cover is slidably connected to the sliding cover. The inner side wall of the shooting tent is provided with a lighting component. A longitudinal shooting track is provided inside the fixed cover, and the shooting track abuts against the inner side wall of the fixed cover. A detachable shooting stand is provided on the shooting track, and a camera is provided on any shooting stand. This device can complete all-around image acquisition of geotechnical samples, ensuring image continuity. It features a simple structure, reasonable design, elegant appearance, and is used for 3D panoramic image acquisition. It can effectively complete full-view material acquisition with high efficiency and good quality.

The utility model proposes a hemisphere cover, which relates to the field of covering device technology. It includes a first arc-shaped plate and a second arc-shaped plate, wherein the second arc-shaped plate is rotatably connected to the first arc-shaped plate through a rotation mechanism; the first arc-shaped plate has a cavity for accommodating the second arc-shaped plate, and the second arc-shaped plate is slidably arranged in the cavity of the first arc-shaped plate; the rotation mechanism includes a fixing member and a rotating member, the rotating member is a hollow tube with limit pieces provided on the inner wall, the outer wall of the fixing member is provided with wedges adapted to the limit pieces, the rotating member is sleeved outside the fixing member, the rotating member is fixedly connected to the second arc-shaped plate, and the fixing member is fixedly connected to the first arc-shaped plate. The first arc-shaped plate and the second arc-shaped plate of the device are connected through the rotation mechanism, which is divided into a fixing member and a rotating member. By fixing the fixing member and the rotating member respectively on the first arc-shaped plate and the second arc-shaped plate, the rotation of the second arc-shaped plate is driven by the rotating member, thereby accurately controlling the opening and closing angle of the hemisphere cover.

本书首先介绍了scikit-learn中的机器学习和XGBoost技术，然后探讨了梯度提升背后的理论知识。包括决策树、装袋技术及XGBoost超参数。本书将从头开始构建梯度提升模型，并将梯度提升扩展到大数据领域。本书重点探讨XGBoost的细节，着重于速度增强和通过数学推导导出参数。通过详细案例研究，练习使用 scikit-learn 、原始的 Python API 构建、以及微调 XGBoost 分类器和回归器。利用XGBoost超参数来提高评分、纠正缺失值、缩放不平衡数据集以及微调备选基学习器。最后，应用高级 XGBoost 技术，如构建非相关的集成模型、堆叠模型，并使用稀疏矩阵、定制的转换器和管道为行业部署准备模型。全书共分3篇：第1篇（第1～4章）为入门篇，介绍XGBoost背后的实用理论，包括装袋和提升模型结构、数据预处理、回归和分类模型、XGBoost基本模型及超参数微调；第2篇（第5～7章）为进阶篇，介绍XGBoost框架构成及超参数优化；第3篇（第8 10章）为进阶篇，着重讨论微调备选基学习器、创新技巧、特征工程，并使用稀疏矩阵、定制转换器和管道，练习构建适合行业部署的模型。全书提供了大量应用实例。本书适合作为高等院校计算机、软件工程专业高年级本科生、研究生的教材，同时适合有一定机器学习基础的数据科学家、机器学习工程师和研究人员阅读，为解决复杂问题提供实用指导。

The invention discloses a road perception method and system based on millimeter wave radar, comprising the following steps: S1, the vehicle detects whether there is a base station in the surrounding environment; S2, determining whether networking is required; S3, performing signal analysis on the network formed in step S2, determining the network status, if the network is normal, performing target detection processing, if the network is abnormal, continuing to detect surrounding base stations that can form a network; S4, classifying the detected targets, performing behavior analysis and condition analysis on the classified targets; S5, determining whether the target will affect driving, if it does not affect normal driving, continue detection. The road perception method and system based on millimeter wave radar not only can detect road conditions, but also enable vehicles to communicate using RF networking, perform network detection using multiple base stations, and share communication results, thereby improving detection accuracy and expanding the detection range.

The invention discloses a personnel re-identification system based on RF signals in foundation pit construction scenarios, including an RF transceiver base station and an RF receiver base station. The RF transceiver base station is used to emit RF signals to form a signal field and receive reflected RF signals to obtain data in the signal field. The RF receiver base station is used to receive the remaining scattered waves. The RF transceiver base station includes an RF transmitting unit and an RF receiving unit. The invention adopts a personnel re-identification system and method based on RF signals in foundation pit construction scenarios, which achieves personnel tracking, positioning, and behavior analysis through RF coverage and data collection, reducing operational error risks, saving equipment costs, and improving safety performance.