期刊文献+
共找到9,601篇文章
< 1 2 250 >
每页显示 20 50 100
Active Machine Learning for Chemical Engineers:A Bright Future Lies Ahead! 被引量:1
1
作者 Yannick Ureel Maarten R.Dobbelaere +4 位作者 Yi Ouyang Kevin De Ras Maarten K.Sabbe Guy B.Marin Kevin M.Van Geem 《Engineering》 SCIE EI CAS CSCD 2023年第8期23-30,共8页
By combining machine learning with the design of experiments,thereby achieving so-called active machine learning,more efficient and cheaper research can be conducted.Machine learning algorithms are more flexible and a... By combining machine learning with the design of experiments,thereby achieving so-called active machine learning,more efficient and cheaper research can be conducted.Machine learning algorithms are more flexible and are better than traditional design of experiment algorithms at investigating processes spanning all length scales of chemical engineering.While active machine learning algorithms are maturing,their applications are falling behind.In this article,three types of challenges presented by active machine learning—namely,convincing the experimental researcher,the flexibility of data creation,and the robustness of active machine learning algorithms—are identified,and ways to overcome them are discussed.A bright future lies ahead for active machine learning in chemical engineering,thanks to increasing automation and more efficient algorithms that can drive novel discoveries. 展开更多
关键词 Active machine learning Active learning Bayesian optimization Chemical engineering Design of experiments
下载PDF
Interactive Training Model of TRIZ for Mechanical Engineers in China 被引量:9
2
作者 TAN Runhua ZHANG Huangao 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2014年第2期240-248,共9页
Abstract: Innovation is a process of taking an original idea and converting it into a business value, in which the engineers face some inventive problems which can be solved hardly by experience. TRIZ, as a new theor... Abstract: Innovation is a process of taking an original idea and converting it into a business value, in which the engineers face some inventive problems which can be solved hardly by experience. TRIZ, as a new theory for companies in China, provides both conceptual and procedural knowledge for finding and solving inventive problems. Because the government plays a leading role in the diffusion of TRIZ, too many companies from different industries are waiting to be trained, but the quantity of the trainers mastering TRIZ is incompatible with that requirement. In this context, to improve the training effect, an interactive training model of TRIZ for the mechanical engineers in China is developed and the implementation in the form of training classes is carried out. The training process is divided into 6 phases as follows: selecting engineers, training stage-l, finding problems, training stage-2, finding solutions and summing up. The government, TRIZ institutions and companies to join the programs interact during the process. The government initiates and monitors a project in form of a training class of TRIZ and selects companies to join the programs. Each selected companies choose a few engineers to join the class and supervises the training result. The TRIZ institutions design the training courses and carry out training curriculum. With the beginning of the class, an effective communication channel is established by means of interview, discussion face to face, E-mail, QQ and so on. After two years training practices, the results show that innovative abilities of the engineers to join and pass the final examinations increased distinctly, and most of companies joined the training class have taken congnizance of the power of TRIZ for product innovation. This research proposes an interactive training model of TRIZ for mechanical engineers in China to expedite the knowledge diffusion of TRIZ. 展开更多
关键词 TR1Z interactive training model innovative abilities for mechanical engineers knowledge diffusion
下载PDF
What Do Educators Need to Teach for Prospective Knowledge Engineers? 被引量:1
3
作者 Jay Liebowitz(Dept. of Management Science, George Washington University, Washington, D. C. 20052) 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1995年第3期1-6,共6页
As expert systems technology has matured and migrated into mainstream computing, there arestill areas which are overlooked in education prospective knowledge engineers. This paper addresses this issue, and provides a ... As expert systems technology has matured and migrated into mainstream computing, there arestill areas which are overlooked in education prospective knowledge engineers. This paper addresses this issue, and provides a message to educators that expert and knowledge-based systems should be an importantstrategic science and technology for many organizations. 展开更多
关键词 Knowledge engineers Expert systems Intelligent systems Knowledge engineering
下载PDF
Introduction of Education Systems for Clinical Engineers in Japan
4
作者 Jun Yoshioka Keiko Fukuta +2 位作者 Hiroki Igeta Takeshi Ifuku Tadayuki Kawasaki 《中国医疗设备》 2016年第9期1-4,共4页
Japanese clinical engineer(CE) is a significant and unique profession compared with other nations with its dual clinical and technology focus and national licensing. The CE system of licensing was established in May 1... Japanese clinical engineer(CE) is a significant and unique profession compared with other nations with its dual clinical and technology focus and national licensing. The CE system of licensing was established in May 1987 under the Clinical Engineers Act. CEs are required to complete 3 to 4 years in designated schools and pass a national examination. It is a professional medical position responsible for the operation and maintenance of life-support and non-life-support medical device systems under the direction of physicians. Currently approximately 70 educational institutes- including technical colleges and universities- provide diverse and wide-ranging curricula from engineering to various clinical disciplines to produce CEs. Since clinical practice training is mandatory as a part of institute work, an important approach for CEs is gained by working in hospitals. The comprehensive curricula and the licensing system in Japan together serve to keep the appropriate quantity and quality of CEs. The Japan Association for Clinical Engineers(JACE) was established in February 1990; one of its aims is to support improvement of CEs throughout their careers through various lectures, seminars, on-the-job trainings, workshops, and an annual member meeting. New CEs can now take advantage of video e-learning. For junior CEs, there are seminars for hyperbaric oxygen therapy, blood purification, heart-lung bypass, respiratory therapy, operating room, intensive care unit, arrhythmia and aphaeresis related devices, as well as healthcare technology management(HTM). Also, the institutes provide a leadership seminar alongside this clinical practice training. Besides the licensing process, a proper certification system for CEs is a critical element in the clinical field. This enhances the ability of CEs to engage in more extensive duties and develop specialties, as well as to provide better healthcare. Associated societies provide certification with technology qualifications in dialysis, extracorporeal circulation, respiratory therapy, clinical medical devices, hyperbaric oxygen therapy, and aphaeresis treatment. JACE also launched a unique certification system in 2010, with specializations in blood purification, arrhythmia, respiratory, and hyperbaric oxygen care. What is the difference between certification by the associated societies and that offered by JACE? Certification by the associated societies provides basic knowledge to pass specialty examinations. Certifications by JACE promote deeper knowledge to enhance clinical decisionmaking and to encourage wider experience. JACE also continues to investigate other certifications. In summary, Japan has introduced a national licensing system for keeping an intake of constant quality and quantity of CEs. Additionally, ongoing workshops and seminars stimulate in-depth knowledge and a higher level of medical care for patients. Together, a system of lifelong education for CEs has been built. 展开更多
关键词 JAPANESE CLINICAL ENGINEER JAPAN Association for CLINICAL engineers national LICENSE CERTIFICATION system
下载PDF
Function Words Analysis——A Reading Comprehension Aid for Chinese Engineers
5
作者 Wu Shuoping and Liu Lian(The Second Academy, MAS) 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1990年第1期86-90,共5页
Background Generally speaking. Chinese college graduates in the fifties and sixties took Russian as their second language, and those who graduated in the seventies had no second language to speak of. Now, in the years... Background Generally speaking. Chinese college graduates in the fifties and sixties took Russian as their second language, and those who graduated in the seventies had no second language to speak of. Now, in the years of our Open Door Policy, they find they have to learn some English and learn it quickly. They try to learn from radio and TV and many take English courses of 4 to 6 months, with varying degree of success. Their chief stumbling blocks 展开更多
关键词 Function Words Analysis A Reading Comprehension Aid for Chinese engineers
下载PDF
Shanghai Hosts the World Engineers' Convention 2004
6
《ZTE Communications》 2004年第2期63-63,共1页
The World Engineers’ Convention2004(WEC2004)was held onNovember 2-6,2004 in Shanghai,China. The motto of the conventionis“Engineers Shape the SustainableFuture.”It advocates that engineersshould take the task of ma... The World Engineers’ Convention2004(WEC2004)was held onNovember 2-6,2004 in Shanghai,China. The motto of the conventionis“Engineers Shape the SustainableFuture.”It advocates that engineersshould take the task of makingpeople’s life better and commit tocreating a new world.Engineers should be well awareof their responsibilities:developingnew technologies and making good 展开更多
关键词 World Convention 2004 Shanghai Hosts the World engineers
下载PDF
Four Engineers...
7
《英语自学》 2000年第3期44-,共1页
There are four engineers traveling in a car;a mechanical engineer,a chemical engi-neer,an electrical engineer and a comput-er engineer.The car breaks down.“Sounds to me as if the pistons have seized.We ll have to str... There are four engineers traveling in a car;a mechanical engineer,a chemical engi-neer,an electrical engineer and a comput-er engineer.The car breaks down.“Sounds to me as if the pistons have seized.We ll have to strip down the engine before we canget the car working again,”says the 展开更多
关键词 Four engineers
下载PDF
Engineers in the Making
8
作者 Ge Lijun Ibrahima Mbodj 《ChinAfrica》 2017年第3期36-37,共2页
FOR Martine DiengAwa and Seydou KaThierno. two 18-year-old classmates from Kolda Town in south Senegal, the prospect of studying abroad after high school seemed an unimaginable and almost impossible dream. Little did ... FOR Martine DiengAwa and Seydou KaThierno. two 18-year-old classmates from Kolda Town in south Senegal, the prospect of studying abroad after high school seemed an unimaginable and almost impossible dream. Little did they know that they would end up a few months later being classmates again, but this time in faraway China, 展开更多
关键词 engineers in the Making
下载PDF
A Perspective on Smart Process Manufacturing Research Challenges forProcess Systems Engineers 被引量:8
9
作者 Ian David Lockhart Bogle 《Engineering》 SCIE EI 2017年第2期161-165,共5页
The challenges posed by smart manufacturing for the process industries and for process systems engineering(PSE) researchers are discussed in this article. Much progress has been made in achieving plant- and site-wid... The challenges posed by smart manufacturing for the process industries and for process systems engineering(PSE) researchers are discussed in this article. Much progress has been made in achieving plant- and site-wide optimization, hut benchmarking would give greater confidence. Technical challenges confrontingprocess systems engineers in developing enabling tools and techniques are discussed regarding flexibilityand uncertainty, responsiveness and agility, robustness and security, the prediction of mixture propertiesand function, and new modeling and mathematics paradigms. Exploiting intelligence from big data to driveagility will require tackling new challenges, such as how to ensure the consistency and confidentiality ofdata through long and complex supply chains. Modeling challenges also exist, and involve ensuring that allkey aspects are properly modeled, particularly where health, safety, and environmental concerns requireaccurate predictions of small but critical amounts at specific locations. Environmental concerns will requireus to keep a closer track on all molecular species so that they are optimally used to create sustainablesolutions. Disruptive business models may result, particularly from new personalized products, but that isdifficult to predict. 展开更多
关键词 SMART MANUFACTURING Process systems engineering UNCERTAINTY FLEXIBILITY Optimization MODEL-BASED control
下载PDF
TRIZ: The Enlightenment of the Training Mode of Excellent Chinese Engineers 被引量:1
10
作者 Yiyang Fan Yuting Qiu Xing Zhang 《Engineering(科研)》 2012年第12期908-913,共6页
China has been the largest country in terms of the scale of higher engineering education in the world. The training plan of excellent engineers (TPEE) that launched in 2010 is to train various types of high-quality en... China has been the largest country in terms of the scale of higher engineering education in the world. The training plan of excellent engineers (TPEE) that launched in 2010 is to train various types of high-quality engineers and technical personnel who have strong innovative abilities and meet the need of economic and social development. The theory of inventive problem solving (TRIZ), as a scientific methodology to solve innovation problems, provides a theoretical basis and practical guideline for the training of excellent engineers. This paper analyzes the teaching philosophy and methods for the training of excellent engineers within TRIZ framework from the demand perspective, and then discusses the enlightenment of disseminating TRIZ in the following aspects, such as TRIZ application in science, technology, engineering, and mathematics (STEM) education, faculty development, platform development of innovative education and so on. 展开更多
关键词 TRIZ EXCELLENT ENGINEER Training Mode Engineering Education
下载PDF
Science and reflections: With some thoughts to young applied scientists and engineers
11
作者 Robert L Nowack 《Earthquake Science》 2024年第5期459-493,共35页
I provide some science and reflections from my experiences working in geophysics,along with connections to computational and data sciences,including recent developments in machine learning.I highlight several individu... I provide some science and reflections from my experiences working in geophysics,along with connections to computational and data sciences,including recent developments in machine learning.I highlight several individuals and groups who have influenced me,both through direct collaborations as well as from ideas and insights that I have learned from.While my reflections are rooted in geophysics,they should also be relevant to other computational scientific and engineering fields.I also provide some thoughts for young,applied scientists and engineers. 展开更多
关键词 geophysics computational and data science applied science and engineering
下载PDF
WOMEN PROVINGTHEY CANHANDLE POWER Engineers with State Grid in Tianjin Are Defying Traditional Roles
12
作者 Yang Cheng 《Women of China》 2024年第9期38-41,共4页
A woman-adorned in a heavy,custom-made,metal-shielding suit-is hard at work,dozens of meters above the ground.Arcs of electricity flicker at her fingertips,and the crackling sound of current lingers in her ears.Lookin... A woman-adorned in a heavy,custom-made,metal-shielding suit-is hard at work,dozens of meters above the ground.Arcs of electricity flicker at her fingertips,and the crackling sound of current lingers in her ears.Looking up from the ground,the engineer,working on an electric tower,resembles a nimble dancer,gracefully navigating along the power lines connecting various pylons.This is a typical workday for a live-line-maintenance engineer with State Grid Tianjin Electric Power Company.In North China's Tianjin Municipality,women engineers-many of whom born after 1990-are proving they are as capable and dedicated as their male counterparts. 展开更多
关键词 connecting Tianjin engineer
原文传递
基于变化更新的中东欧国家森林覆盖制图
13
作者 王春玲 史锴源 +1 位作者 庞勇 蒙诗栎 《林业科学》 EI CAS CSCD 北大核心 2024年第5期116-126,共11页
[目的]分析中东欧国家森林资源覆盖状况,了解中东欧各国林业的现实情形和独特优势,为中国与中东欧国家加强林业合作提供基础数据。[方法]基于Google Earth Engine(GEE)平台获取中东欧国家2020年生长季无云影像,利用随机森林算法对影像... [目的]分析中东欧国家森林资源覆盖状况,了解中东欧各国林业的现实情形和独特优势,为中国与中东欧国家加强林业合作提供基础数据。[方法]基于Google Earth Engine(GEE)平台获取中东欧国家2020年生长季无云影像,利用随机森林算法对影像进行分类,应用连续变化检测和分类算法得到森林变化信息并更新初步分类结果,最终获得中东欧国家土地覆盖分类结果。利用欧盟统计局土地利用/覆盖区域框架调查(LUCAS)数据、目视解译数据以及联合国粮农组织统计数据(FAOSTAT)对本研究分类结果进行验证和评估,结合谷歌高分辨率影像对制图结果进行分析。[结果]本研究分类结果利用LUCAS数据和目视解译数据的森林类型用户精度分别为0.930和0.911,生产者精度分别为0.860和0.956,总体精度分别为0.810和0.881,整体上优于GlobeLand30 2020产品(森林类型用户精度分别为0.920和0.900,生产者精度分别为0.690和0.840,总体精度分别为0.700和0.832)。根据研究结果计算出中东欧国家总体森林覆盖率为39.6%,相比GlobeLand30 2020结果(34.4%),与FAOSTAT的森林覆盖率(40.0%)更接近。目视上看,本制图结果在细节刻画上比GlobeLand30 2020产品更丰富,更能准确反映森林分布特征。截至2020年,中东欧国家森林覆盖呈北部、东南地区和西南地区丰富密集,中部分布广泛且相对较少的特点,爱沙尼亚、拉脱维亚、斯洛文尼亚、黑山等国家森林分布茂密,波兰、匈牙利等国家森林分布较为稀少。[结论]针对中东欧国家森林覆盖应用需求,本研究提出基于产品变化更新的森林覆盖制图方法,生产了中东欧国家2020年森林覆盖产品。本研究方法可为大区域森林覆盖制图提供新的借鉴和参考,结果有助于宏观了解中东欧国家森林覆盖状况。 展开更多
关键词 中东欧国家 Google Earth Engine 森林资源 遥感监测
下载PDF
京津风沙源区NPP时空变化及其对治理工程实施的响应
14
作者 赵恒谦 刘轩绮 +6 位作者 刘哿 付含聪 张宇娇 杜守航 蒋金豹 郭伟 杨姿涵 《生态学报》 CAS CSCD 北大核心 2024年第6期2406-2419,共14页
利用遥感大数据对生态治理工程区域的净初级生产力和固碳能力进行长期动态监测可以实现对治理工程的实施效果的评价,同时为区域“碳中和”目标的实现及可持续发展提供有力支撑。利用Google Earth Engine(GEE)云计算平台,基于改进的CASA... 利用遥感大数据对生态治理工程区域的净初级生产力和固碳能力进行长期动态监测可以实现对治理工程的实施效果的评价,同时为区域“碳中和”目标的实现及可持续发展提供有力支撑。利用Google Earth Engine(GEE)云计算平台,基于改进的CASA模型对京津风沙源治理工程区域的NPP进行计算。运用Sen斜率分析和MK趋势分析方法对2001—2020年间的NPP进行时空变化分析,并分析NPP对京津风沙源治理工程实施的响应。结果表明:1)在京津风沙源工程治理期间,京津风沙源区NPP总体呈波动上升趋势,平均增速为2.21 gC m^(-2)a^(-1),其中极显著增加区域占38.03%,说明京津风沙源治理工程对我国“碳中和”任务起到了积极作用,增加了区域的固碳能力;2)空间尺度上,京津风沙源区NPP和固碳量空间异质性较大,空间分布上主要呈现东部高,西部低的特点,其中,暖温带落叶阔叶林区域最高,温带荒漠区域最低;3)治理工程的实施所带来的NPP增长的速度在不同的区域并不一致,2001—2020年的NPP增速京津冀地区(4.74 gC m^(-2)a^(-1))>山西地区(4.52 gC m^(-2)a^(-1))>陕西地区(3.53 gC m^(-2)a^(-1))>内蒙古地区(1.55 gC m^(-2)a^(-1));4)生态工程实施所带来的生态环境的改善总体呈现先慢后快的特点,绝大部分区域后十年间的变化速率都显著大于前十年,而在生态环境较为恶劣、荒漠区域广布的内蒙古地区,生态环境的改善则具有一定的滞后性,2001—2010年NPP增速仅为0.04 gC m^(-2)a^(-1),直到2011年,NPP才开始有较为明显的增长,2011—2020年NPP增速为1.67 gC m^(-2)a^(-1)。风沙源治理工程需要长期坚持,才能取得更明显的成效。 展开更多
关键词 京津风沙源治理工程 Google Earth Engine云平台 CASA模型 植被净初级生产力 固碳能力 时空变化
下载PDF
基于Sentinel-5P的长三角大气NO_(2)污染特征及影响因子分析
15
作者 曹念文 宋坤杰 方文圣 《安全与环境学报》 CAS CSCD 北大核心 2024年第2期767-777,共11页
基于哨兵-5P(Sentinel-5 Precursor,Sentinel-5P)卫星反演的NO_(2)柱浓度数据,利用Google Earth Engine云平台,结合自然因子和人为社会因子数据,分析长三角地区大气NO_(2)柱浓度的污染特征及影响因素。结果显示:(1)Sentinel-5P卫星反演... 基于哨兵-5P(Sentinel-5 Precursor,Sentinel-5P)卫星反演的NO_(2)柱浓度数据,利用Google Earth Engine云平台,结合自然因子和人为社会因子数据,分析长三角地区大气NO_(2)柱浓度的污染特征及影响因素。结果显示:(1)Sentinel-5P卫星反演的NO_(2)柱浓度数据与地面观测站NO_(2)质量浓度具有较好的相关性(r≥0.59,p<0.01),可较为准确地反映长三角地区大气NO_(2)污染状况;(2)长三角的大气NO_(2)柱浓度呈现季节性的周期波动,呈“冬高夏低”变化趋势;(3)大气NO_(2)柱浓度具有显著的空间异质性,整体上东北高,西南低,呈现出一条六安至台州,即“西北—东南”方向的NO_(2)柱浓度分界线,以及一个以环太湖城市群为中心的西南向“U形口”;(4)植被指数、高程、全社会用电量、第二产业产值、第三产业产值是长三角大气NO_(2)柱浓度空间分布的重要影响因子,区域大气NO_(2)柱浓度受因子交互作用显著,高程及植被指数与其他因子的交互作用q均在0.6以上。 展开更多
关键词 环境学 NO_(2)污染 长江三角洲 Google Earth Engine 地理探测器
下载PDF
STEM教育与研究
16
作者 柳秀峰 翟彦芳 《中国科技教育》 2024年第2期15-19,共5页
STEM,即科学(Science)、技术(Technology)、工程(Engineering)和数学(Mathematics)的缩写,最早由美国国家科学基金会(NSF)提出并应用,并将这一术语用于对教育和劳动力发展项目进行分类[1]。自21世纪初以来,美国国家科学基金会一直在其... STEM,即科学(Science)、技术(Technology)、工程(Engineering)和数学(Mathematics)的缩写,最早由美国国家科学基金会(NSF)提出并应用,并将这一术语用于对教育和劳动力发展项目进行分类[1]。自21世纪初以来,美国国家科学基金会一直在其发布的出版物和提交给国会的预算申请中使用这一术语,用以指一系列相关项目。尽管STEM教育深受欢迎,但目前还没有一个统一的定义或广泛接受的概念[2]。 展开更多
关键词 美国国家科学基金会 STEM教育 ENGINEERING
下载PDF
中国西南山地城市生态环境质量长时序变化及其评价——以重庆市为例 被引量:1
17
作者 苟晓娟 刘瑞 李谷琳 《物探化探计算技术》 CAS 2024年第2期224-234,共11页
为研究中国西南地区山地城市的生态环境质量,选择以重庆市为例,利用遥感技术和Google Earth Engine(GEE)平台,构建遥感生态指数(RSEI,remote sensing ecological index),评价重庆市2000年~2021年的生态环境质量及其长时序变化。为探讨... 为研究中国西南地区山地城市的生态环境质量,选择以重庆市为例,利用遥感技术和Google Earth Engine(GEE)平台,构建遥感生态指数(RSEI,remote sensing ecological index),评价重庆市2000年~2021年的生态环境质量及其长时序变化。为探讨山地城市生态环境质量的主要影响因素,选取海拔、坡度、气温和降水四个影响因子,得到RSEI的海拔依赖性与坡度依赖性以及RSEI与气候因子的响应关系。结果表明:①遥感生态指数RSEI总体呈上升趋势,生态质量为“优”的面积增加了130.27%,生态质量为“差”的面积减少了65.68%,生态环境有明显的改善;②从RSEI随海拔、坡度变化曲线可以看出,0 m~1800 m范围内RSEI缓慢增加,1800 m~2800 m范围内开始减小,RSEI随坡度增加而增长,坡度>40°之后RSEI趋于平稳;③从RSEI与气候因子的响应曲线可以看出,温度和RSEI呈负相关,温度越高,RSEI越低;随着降水的增加,RSEI指数逐渐上升。研究表明,使用GEE平台可以对多云雾、植被覆盖度高的西南山地城市的生态环境质量进行长时序的监测和评价。研究结果可为中国西南地区山地城市的生态环境保护提供精细化管理,从而根据区域特色进行环境治理,实现生态环境与经济的协调发展。 展开更多
关键词 Google Earth Engine RSEI 西南山地城市 重庆 海拔 气候 生态保护
下载PDF
耦合时序特征的林分类型遥感识别
18
作者 高雨珊 彭道黎 +4 位作者 张楠 杨鹏辉 杨灿灿 陈铭捷 陈健 《北京林业大学学报》 CAS CSCD 北大核心 2024年第1期68-81,共14页
【目的】结合多源遥感数据进行特征提取,获取最优分类策略并探究时间序列特征在林分类型识别中的重要性,为遥感林分类型识别提供技术途径。【方法】结合Sentinel-2光谱特征和时间序列特征、Sentinel-1雷达后向散射特征和SRTM DEM地形特... 【目的】结合多源遥感数据进行特征提取,获取最优分类策略并探究时间序列特征在林分类型识别中的重要性,为遥感林分类型识别提供技术途径。【方法】结合Sentinel-2光谱特征和时间序列特征、Sentinel-1雷达后向散射特征和SRTM DEM地形特征在Google Earth Engine中进行各特征变量的提取,构建不同特征组合使用随机森林分类器进行分类并对不同分类结果进行制图输出和精度评价。【结果】(1)使用Sentinel-2时间序列光谱特征、Sentinel-1雷达后向散射特征和SRTM DEM地形特征的方案分类效果最好,总体精度为84.62%,Kappa系数为0.82;(2)在构建的5个不同特征组合方案中,多特征组合的方案分类效果优于单一特征;(3)地形特征、后向散射特征和时间序列特征对于分类结果非常重要,尤其是时间序列特征的加入能大大提升林分类型识别精度。光谱特征中短红外波段B11和B12最重要,时间序列特征中4月份和10月份为最重要的时间节点。【结论】基于多源遥感数据提取的多特征分类方案能够有效进行研究区林分类型识别,地形特征、后向散射特征和Sentinel-2时间序列特征可以作为光谱特征的有效辅助特征变量提高分类精度,使林分类型识别更为准确,尤其是时间序列特征在提高林分类型识别精度上有突出作用。 展开更多
关键词 Sentinel-2 Sentinel-1 随机森林 Google Earth Engine(GEE) 时间序列特征
下载PDF
基于GEE的Landsat-8与Sentinel-2影像在棉花种植提取中差异性分析及提取方法对比研究
19
作者 洪国军 周保平 +5 位作者 李明哲 李森威 刘成成 张灵 付仙兵 李旭 《江苏农业科学》 北大核心 2024年第4期223-230,共8页
棉花作为南疆地区重要的经济作物之一,在经济工作中起着至关重要的作用。及时、准确地获取棉花种植面积,对农业政策和经济发展具有重要意义。为了实现这一目标,需要综合分析不同方法和遥感数据对最终棉花种植面积制图精度的影响。本研... 棉花作为南疆地区重要的经济作物之一,在经济工作中起着至关重要的作用。及时、准确地获取棉花种植面积,对农业政策和经济发展具有重要意义。为了实现这一目标,需要综合分析不同方法和遥感数据对最终棉花种植面积制图精度的影响。本研究以新疆阿克苏地区棉花种植区为例,借助Google Earth Engine云平台,采用随机森林法(RF)、支持向量机法(SVM)、最小距离分类法(MDC)等3种机器学习方法,利用2类中分辨率影像提取棉花种植信息,充分评估使用的档案数据和官方统计数字。结果表明,采用Sentinel-2方法和RF获得了最优棉花图,随机森林法分类器的总体精度、Kappa系数和用户精度分别高达97.4%、96.7%和91.1%,分别比Landsat-8图像和RF模型的结果高出7.3百分点、0.081、2.8百分点。与官方统计数据相比,采用RF、SVM、MDC对Sentinel-2和Landsat-8图像的棉花种植面积估算图的精度分别为98.4%、95.8%、79.6%和90.3%、83.7%、72.5%。很明显,Sentinel-2和RF模型的组合与官方数据的一致性最高。对比分析结果表明,Landsat-8和Sentinel-2数据可用于大范围复杂种植结构的棉花高精度测绘。本研究结果有望为棉花大面积鉴别提供一定的理论指导和实践指导。 展开更多
关键词 棉花分类 Sentinel-2 Landsat-8 随机森林 支持向量机 最小距离分类 Google Earth Engine
下载PDF
滇池蓝藻水华时空变化特征及环境影响因素
20
作者 龚铭 王百群 +1 位作者 赵方凯 于洋 《水土保持研究》 CSCD 北大核心 2024年第4期419-429,共11页
[目的]明晰滇池流域水体富营养化演变特征和水体综合治理状况及其主要驱动因素,为滇池流域水污染治理和水生态修复提供科学支撑。[方法]以滇池为研究对象,采用Google Earth Engine(GEE)和遥感监测分析2002—2021年期间滇池蓝藻水华的时... [目的]明晰滇池流域水体富营养化演变特征和水体综合治理状况及其主要驱动因素,为滇池流域水污染治理和水生态修复提供科学支撑。[方法]以滇池为研究对象,采用Google Earth Engine(GEE)和遥感监测分析2002—2021年期间滇池蓝藻水华的时空变化,并探讨了蓝藻水华与环境因子之间的关系。[结果]2002—2021年,滇池蓝藻水华面积变化具有显著的年际特征,在2006年、2013年和2016年出现峰值,分别为1.952×10^(7),2.010×10^(7),1.743×10^(7) m^(2);在2005年、2010年和2014年出现谷值,分别为1.243×10^(7),1.156×10^(7),1.163×10^(7) m^(2)。2016年后蓝藻水华面积稳定波动,整体无明显变化趋势,2021年面积为1.709×10^(7) m^(2)。在月份尺度,蓝藻水华主要发生在7—12月,8月达到峰值,11—2月持续降低,2月达谷值。蓝藻水华与气温、降水量之间呈现正相关关系,与风向呈现显著负相关关系(p<0.05),与风向呈现最为密切的显著相关关系(p<0.05),受滇池地形等因素影响,4种气象因子中风向因子重要性最高,偏东的风向对滇池蓝藻水华覆盖率具有显著促进作用。[结论]滇池蓝藻整体保持稳定波动无显著演变趋势,未来滇池水生态修复应深入考量风向、风速对蓝藻爆发的重要驱动作用。 展开更多
关键词 蓝藻水华 滇池 Google Earth Engine
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部