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矿山无人机航测成图质量的控制方法分析

世界有色金属 2024年第8期 156-158页

作者：何学志李九鸿龚弦中国建筑材料工业地质勘查中心四川总队四川成都610000 中交二航局(成都)建设工程有限公司四川成都610000

无人机航测是测绘领域传统航空摄影测量的重要补充,需进一步控制无人机航测成图质量。本文以焦岱镇矿山为例,布设测区控制点,从影像重叠度、航带弯曲度、航带内最大高差、像片倾角检查航测成图影像质量,借助摄影测量系统进行内业数据精... 详细信息

无人机航测是测绘领域传统航空摄影测量的重要补充,需进一步控制无人机航测成图质量。本文以焦岱镇矿山为例,布设测区控制点,从影像重叠度、航带弯曲度、航带内最大高差、像片倾角检查航测成图影像质量,借助摄影测量系统进行内业数据精度分析,包括影像数据分析、空中三角测量精度分析和成图精度分析,得出航测地形图平面误差0.327m,高程误差0.337m,与实测成图相比高程误差较大,针对性提出采用高程扭曲公式获取高程改正值,提高倾斜航带高程精度,保证矿山无人机航测成图质量得到有效控制。

关键词：无人机航测成图平面误差高程误差

Data-based real-time petrochemical gas diffusion simulation approach on virtual reality

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Virtual Reality & Intelligent Hardware 2023年第3期5卷 266-278页

作者： Min YANG Yong HAN Chang SU xue li Faculty of Information Science and Engineering Ocean University of ChinaQingdao 266100China Laboratory for Regional Oceanography and Numerical Modeling Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237China

Background Petrochemical products possess a high risk of flammability,explosivity,and toxicity,making petrochemical accidents exceedingly destructive.Therefore,disaster analysis,prediction,and real-time simulations have become important means of controlling and reducing accident hazards.Methods This study proposes a complete real-time simulation solution of gas diffusion with coordinate and concentration data,which was mainly aimed at simulating the types of harmful gas leakage and diffusion accidents in the petrochemical industry.The rendering effect was more continuous and accurate through grid homogenization and trilinear interpolation.This study presents a data processing and rendering parallelization process to enhance simulation efficiency.Gas concentration and fragment transparency were combined to synthesize transparent pixels in a scene.To ensure the approximate accuracy of the rendering effect,improve the efficiency of real-time rendering,and meet the requirement of intuitive perception using concentration data,a weighted blended order-independent transparency(OIT)with enhanced alpha weight is presented,which can provide a more intuitive perception of the hierarchical information of concentration data while preserving depth information.This study compares and analyzes three OIT algorithms-depth peeling,weighted blended OIT,and weighted blended OIT with enhanced alpha weight-in terms of rendering image quality,rendering time,required memory,and hierarchical information.Results Using weighted blended OIT with an enhanced alpha weight technique,the rendering time was shortened by 53.2%compared with that of the depth peeling algorithm,and the texture memory required was significantly smaller than that of the depth peeling algorithm.The rendering results of weighted blended OIT with an enhanced alpha weight were approximately accurate compared with those of the depth peeling algorithm as the ground truth,and there was no popping when surfaces passed through one another.Simultaneously,compared with weighted b

关键词： Real-time gas diffusion simulation Trilinear interpolation Order-independent transparency rendering parallelization

中国大学生灵活就业:从“是什么”到“怎么办”

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中国大学生就业 2024年第1期 34-41页

作者：陈姚周文霞李佳琦中国人民大学劳动人事学院

围绕灵活就业这一社会热点问题,本文从职业生涯教育的角度切入,通过梳理国内外研究和调查访谈,希望厘清当前我国大学生灵活就业与标准就业、传统的灵活就业、国外灵活就业等的区别和发展趋势,回答当代中国大学生灵活就业“是什么”。并... 详细信息

围绕灵活就业这一社会热点问题,本文从职业生涯教育的角度切入,通过梳理国内外研究和调查访谈,希望厘清当前我国大学生灵活就业与标准就业、传统的灵活就业、国外灵活就业等的区别和发展趋势,回答当代中国大学生灵活就业“是什么”。并在量化和质化研究相结合的基础上,挖掘灵活就业与社会产业变革、大学生职业过渡等的关联性,分析应该“怎么看”。同时,围绕“怎么办”和“办得好”,以机制研究为落脚点,主张通过全程化的职业生涯教育地图构建、全方位的生涯教育实施落地、全员化的生涯教育发展行动,逐步构建适应大学生灵活就业需求和趋势的生涯教育体系及职业发展体系。

关键词：大学生灵活就业职业过渡职业生涯教育职业发展

重庆市主城区居民饮用水9种微量元素含量特征及其健康风险评价

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长江科学院院报 2024年第2期41卷 52-60,75页

作者：刘怡陈燕苏婷谭福亚刘永林张雪琰旷霞殷凤赵家宇重庆师范大学地理与旅游学院重庆401331 重庆师范大学地理信息系统应用研究重庆市高校重点实验室重庆401331 柳州市第八中学广西柳州545005 福建省武夷山第一中学福建武夷山354399

为明确重庆市主城区饮用水中微量元素含量及其对居民健康的潜在影响,采集主城区居民末梢饮用水80件、水源地水样3件,室内测定水样中As、Ba、Cr、Cu、Mo、Ni、Sb、Se、Zn含量,并采用USEPA推荐的健康风险评价模型,评估饮用水中微量元素的... 详细信息

为明确重庆市主城区饮用水中微量元素含量及其对居民健康的潜在影响,采集主城区居民末梢饮用水80件、水源地水样3件,室内测定水样中As、Ba、Cr、Cu、Mo、Ni、Sb、Se、Zn含量,并采用USEPA推荐的健康风险评价模型,评估饮用水中微量元素的健康风险水平。结果表明:①重庆市主城区居民末梢饮用水中9种微量元素均值(算术均值,下同)均未超过国家《生活饮用水卫生标准》。②儿童和成人的总健康风险均值分别为8.72×10^(-5)a^(-1)和3.56×10^(-5)a^(-1),在USEPA推荐的最大可接受标准(10-6~10^(-4)a^(-1))内,但儿童总健康风险高于成人。③居民末梢饮用水健康风险主要表现为Cr和As的致癌风险,儿童和成人致癌风险均呈现R Cr(8.54×10^(-5)a^(-1)和3.48×10^(-5)a^(-1))>R As(1.62×10^(-6)a^(-1)和6.74×10^(-7)a^(-1)),但均低于USEPA推荐的最大可接受标准(10^(-4)a^(-1))。因此饮用水中Cr和As是重庆市主城区居民饮用水产生健康风险的主要物质,需进一步加强这2种元素的监测和管理。

关键词：微量元素健康风险居民末梢饮用水砷铬重庆市

基于模型建构的高中物理课堂教学策略初探——以“轻杆”模型的教学为例

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物理教学探讨 2024年第4期42卷 21-24,28页

作者：李池冉雪峰颜长坤重庆市育才中学校重庆400050

基于《普通高中物理课程标准(2017年版2020年修订)》对高中学生物理模型建构能力的要求,提出情境创设、科学抽象、深度理解和应用迁移四个必要的课堂教学环节,进一步设计了“轻杆”模型的教学案例。

关键词：模型建构教学策略轻杆

Surgery for fibrous dysplasia associated with aneurysmal-bone-cystlike changes in right proximal femur:A case report

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世界临床病例杂志 2023年第26期11卷 6170-6175页

作者： Lun-li Xie xiao Yuan Hong-xia Zhu Dan Pu Department of Joint and Hand Orthopedics Hunan University of Medicine General HospitalHuaihua 418000Hunan ProvinceChina Department of Joint and Hand Surgery Hunan University of Medicine General HospitalHuaihua 418000Hunan ProvinceChina Department of Traumatic Orthopedics Hunan University of Medicine General HospitalHuaihua 418000Hunan ProvinceChina Department of Orthopedics Hunan University of Medicine General HospitalHuaihua 418000Hunan ProvinceChina

BACKGROUND Fibrous dysplasia associated with aneurysmal bone cyst(ABC)-like changes in the right proximal femur has a low incidence.It is considered more difficult to make early diagnosis than for single fibrous dysplasia.CASE SUMMARY A 14-year-old woman was admitted because of persistent pain in the right hip and abnormal gait over the previous 2 mo.She had no history of present or past illness.Preoperative photography,enhanced computed tomography,and magnetic resonance imaging showed ground-glass appearance with cortical scalloping and expansion of the right proximal femur and femoral neck.Pathological examination by preoperative puncture biopsy revealed fibrous dysplasia of the right proximal femur.The patient was diagnosed with fibrous dysplasia based on medical history,physical examination,and results of laboratory,imaging and pathological examinations.According to final pathological examination,the patient was diagnosed with fibrous dysplasia of the right proximal femur associated with ABC.Curettage and allograft along with fixation of compression screws was performed for fibrous dysplasia associated with ABClike changes.No obvious allograft absorption,loosening of fixation,or secondary fracture were observed during 6-months’follow-up with re-examination by plain radiography and computed tomography.Fibrous dysplasia associated with ABClike changes in the right proximal femur has a low incidence and early diagnosis is considered more difficult than for single fibrous dysplasia.CONCLUSION We report a cases of fibrous dysplasia associated with ABC-like changes in the right proximal femur treated with curettage and allograft along with hip compression screws.

关键词： Fibrous dysplasia Aneurysmal bone cyst Curettage Allograft Hip compression screws Case report

Predicted Mean Vote of Subway Car Environment Based on Machine Learning

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Big Data Mining and Analytics 2023年第1期6卷 92-105页

作者： Kangkang Huang Shihua Lu Xinjun li Ke Feng Weiwei Chen Yi xia School of Energy and Mechanical Engineering Nanjing Normal UniversityNanjing 210046China

The thermal comfort of passengers in the carriage cannot be ignored.Thus,this research aims to establish a prediction model for the thermal comfort of the internal environment of a subway car and find the optimal input combination in establishing the prediction model of the predicted mean vote(PMV)index.Data-driven modeling utilizes data from experiments and questionnaires conducted in Nanjing Metro.Support vector machine(SVM),decision tree(DT),random forest(RF),and logistic regression(LR)were used to build four models.This research aims to select the most appropriate input variables for the predictive model.All possible combinations of 11 input variables were used to determine the most accurate model,with variable selection for each model comprising 102350 iterations.In the PMV prediction,the RF model was the best when using the correlation coefficients square(R2)as the evaluation indicator(R^(2):0.7680,mean squared error(MSE):0.2868).The variables include clothing temperature(CT),convective heat transfer coefficient between the surface of the human body and the environment(CHTC),black bulb temperature(BBT),and thermal resistance of clothes(TROC).The RF model with MSE as the evaluation index also had the highest accuracy(R^(2):0.7676,MSE:0.2836).The variables include clothing surface area coefficient(CSAC),CT,BBT,and air velocity(AV).The results show that the RF model can efficiently predict the PMV of the subway car environment.

关键词： predicted mean vote random forest variable selection thermal comfort

A Sea Ice Recognition Algorithm in Bohai Based on Random Forest

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Computers, Materials & Continua 2022年第11期73卷 3721-3739页

作者： Tao li Di Wu Rui Han Jinyue xia Yongjun Ren School of Artificial Intelligence/School of Future Technology Nanjing University of Information Science and TechnologyNanjing210044China Unit 93117 of PLA PLAJiangsu210000China International Business Machines Corporation(IBM) NY100014USA School of Computer Science Nanjing University of Information Science and TechnologyNanjing210044China

As an important maritime hub,Bohai Sea Bay provides great convenience for shipping and suffers from sea ice disasters of different severity every winter,which greatly affects the socio-economic and development of the region.Therefore,this paper uses FY-4A(a weather satellite)data to study sea ice in the Bohai Sea.After processing the data for land removal and cloud detection,it combines multi-channel threshold method and adaptive threshold algorithm to realize the recognition of Bohai Sea ice under clear sky conditions.The random forests classification algorithm is introduced in sea ice identification,which can achieve a certain effect of sea ice classification recognition under cloud cover.Under non-clear sky conditions,the results of Bohai Sea ice identification based on random forests have been improved,and the algorithm can effectively identify Bohai Sea Ice and can improve the accuracy of sea ice identification,which lays a foundation for the accuracy and stability of sea ice identification.It realizes sea ice identification in the Bohai Sea and provides data support and algorithm support for marine climate forecasting related departments.

关键词： FY-4A random forests Bohai Sea Ice sea ice identification adaptive threshold

高原地区低剂量食管癌根治性放疗后放射性肺炎影响因素分析

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食管疾病 2024年第2期6卷 102-106页

作者：赵冬梅王丽柏晗卢飞李岚夏耀雄红河州第三人民医院云南红河651400 北京大学肿瘤医院云南医院云南省肿瘤医院昆明医科大学第三附属医院云南昆明650000

目的基于纵向队列分析高原地区低剂量食管癌根治性放疗后放射性肺炎(radiation pneumonia,RP)发生的影响因素。方法回顾性分析2020年7月至2023年6月在云南省肿瘤医院放疗科进行根治性放疗的172例食管癌患者资料,按照美国国立癌症研究所... 详细信息

目的基于纵向队列分析高原地区低剂量食管癌根治性放疗后放射性肺炎(radiation pneumonia,RP)发生的影响因素。方法回顾性分析2020年7月至2023年6月在云南省肿瘤医院放疗科进行根治性放疗的172例食管癌患者资料,按照美国国立癌症研究所常见不良反应术语评定标准5.0版(CTCAE 5.0)进行放射性肺炎的评级,分别收集临床因素、传统独立剂量学特征和剂量区间变化特征。对用于预测是否发生症状性放射性肺炎的特征进行相关性分析,使用结构聚类法进行特征筛选,使用逻辑回归(logisitc regression,LR)进行多因素分析,并用Python进行可视化展示。结果全组172例患者发生RP 81例(47.09%),其中1级53例(30.8%),2级13例(7.5%),3级12例(6.9%),4级3例(1.7%);123例(71.51%)患者接受≤50.4 Gy的低剂量照射;多因素分析显示体力评分(performance Status,PS),间质性肺炎(interstitial pneumonia,IP),处方剂量(plan_dose)是放射性肺炎发生的独立预后因素。结论低剂量背景下高原地区食管癌根治性放疗是安全的,对体力评分较差及既往合并间质性肺炎的患者应谨慎决定放疗剂量。

关键词：高原地区食管癌放射治疗剂量学、放射性肺炎