高分辨率遥感影像的深度学习变化检测方法

为提升高分辨率遥感影像的变化检测精度,提出一种利用深度学习的变化检测方法。在预处理的基础上,利用顾及邻域信息的改进变化矢量分析算法和灰度共生矩阵算法获取影像间光谱和纹理变化,并通过设置自适应采样区间提取最可能的变化和未变化区域样本。构建并训练包含标签层的高斯伯努利深度限制玻尔兹曼机模型,以提取变化和未变化区域深层特征,从而有效辨别变化区域。通过WorldView-3与Pléiades-1影像的试验表明本文方法在变化检测精度方面优于对比方法。     

面向高光谱图像分类的半监督空谱判别分析

为充分利用高光谱图像蕴藏的空间信息提升分类精度,提出了面向高光谱图像分类的半监督空谱判别分析(S3 DA)算法。考虑高光谱图像数据集的空间一致性,首先利用少量标记样本定义类内散度矩阵,保存数据集同类像元的光谱近邻结构;再利用无标记样本定义空间近邻像元散度矩阵,揭示像元间的空间近邻结构和地物的空间分布结构信息。S3 DA既保持数据集在光谱域的可分性,又保存了无标记样本蕴藏的空间域近邻结构,增强了同类像元和空间近邻像元在投影子空间的聚集性,从而提升分类性能。在PaviaU和Indian Pines数据集的试验表明,总体分类精度分别达到81.50%和71.77%。与传统的光谱方法比较,该算法能有效提升高光谱图像数据集的地物分类精度。     

递进式项目教学法在“GIS程序设计”课程中的探索与实践

"GIS程序设计"作为地理信息科学专业的必修课,对学生专业能力的培养起到重要作用,同时GIS开发也是目前地理信息科学专业就业的主要方向。文中结合工程实践,通过校园地理信息系统、森林火灾扩散模拟分析与决策系统、小组答辩自选专题地理信息系统3个从简单到复杂的GIS项目,运用递进式的项目教学方法和团队协作、课上实践、课上提问、课内外答疑、课后作业、编写项目文档等措施对该课程进行改革探索和实践,并取得较好的教学效果。     

Should Geography Educators Adopt Electronic Textbooks?

Significant changes in textbook publishing are at college instructors' door. Textbook representatives are directed to mesmerize potential clients with eye-catching displays and statements about digital literacy of the next generation of college students. Based on a one-year pilot study, in 2014–2015, of an electronic textbook, this commentary shares real experiences with the digital tools, contextualizes the shift in textbook publishing and research on student outcomes, and provides insight in navigating through the Brave New World of digital texts and adaptive learning tools.     

In search of meaningful assessment in the university curriculum: the case for culturally relevant pedagogy

ABSTRACT

The poor performance of Pacific students at university is a concern for every level of society. Conventional models of teaching, learning and assessment have overlooked the cultural background of students, yet the effects of this oversight have been disastrous, alienating and disempowering. Studies of and developments in education in the Pacific and elsewhere offer opportunities to rethink the methods of teaching, learning and assessment of Pacific students in ways that are congruent with their home culture. Informed by the principle of so’a lau pule (the Samoan concept of consensus through consultation and conversation) and ethnographic research methods, this study describes an attempt to rethink ways of teaching, learning and assessing student performance in a third-year course on Resource Conservation and Management in the School of Geography, Earth Science and Environment at the University of the South Pacific. Introduced in 2007, the Student Innovative Contribution to Knowledge (SICK) allows students to participate in key decisions concerning teaching, learning and assessment. SICK is grounded in the principles of inclusiveness and participation. It takes account of the skills and abilities of Pacific students and is aligned with the philosophical basis of Pacific cultures. One hundred and fifty-eight students took part in this study over a 5-year period. Analysis was based on students’ written reviews of the semester’s work, in-depth conversation with individual students and the end-of-the-course evaluation. The findings show that, while students embrace the need for non-conventional forms of teaching, learning and assessment, the most frequently cited responses for non-participation are poor time management and varying perceptions of what is considered an innovative assessment. This study shows that understanding the cultural background of students is critical to creating culturally inclusive learning environments.     

Developing and Sequencing Community Engagement and Experiential Education: A Case Study of Urban Geography Teaching and Research

Community engagement curricula and course design can provide substantial experiences for both community members and participating students. Using a case study approach, this research focuses on four steps in this process: initial community relationship forming, engaging in community service, transitioning to civic engagement, and developing a community-based research program. Narrative examples from student course evaluations position these community-based experiences as transformative for multiple parties. Institutional structures are presented as helpful entrees to engagement for students, while noting that community relationships provide contextualized, powerful, and meaningful relationships, supporting recommendations for emerging and existing community engagement programs.     

Measuring Community and University Impacts of Critical Civic Geography: Insights from Chicago

Geographers have increasingly adopted community-based learning and research into their teaching and scholarly activities since Bunge and Harvey called for an applied public geography that is both useful and challenges societal inequalities. With few exceptions, however, there has been little discussion of methods for measuring this work. Many published assessments focus on the impacts of projects on students but overlook the impacts on community partners. Impacts on faculty and the larger university community are also often ignored. This article discusses literature on the evaluation of community–university research and service learning from a critical perspective. A discussion of service learning and community-based research (CBR) projects at two Chicago universities, DePaul and Chicago State, is presented. In both cases challenges were encountered to achieve full evaluation of projects, yet both included an evaluation of university and community partners that allowed for assessment of the projects’ value to all partners.     

Carbon pricing in practice: a review of existing emissions trading systems

This article analyses the implementation of emissions trading systems (ETSs) in eight jurisdictions: the EU, Switzerland, the Regional Greenhouse Gas Initiative (RGGI) and California in the US, Québec in Canada, New Zealand, the Republic of Korea and pilot schemes in China. The article clarifies what is working, what isn’t and why, when it comes to the practice of implementing an ETS. The eight ETSs are evaluated against five main criteria: environmental effectiveness, economic efficiency, market management, revenue management and stakeholder engagement. Within each of these categories, ETS attributes ? including abatement cost, stringency of the cap, improved allocation practices over time and the trajectory of price stability ? are assessed for each system. Institutional learning, administrative prudence, appropriate carbon revenue management and stakeholder engagement are identified as key ingredients for successful ETS regimes. Recent implementation of ETSs in regions including California, Québec and South Korea indicates significant institutional learning from prior systems, especially the EU ETS, with these regions implementing more robust administrative and regulatory structures suitable for handling unique national and sub-national opportunities and constraints. The analysis also shows that there is potential for a ‘double dividend’ in emissions reductions even with a modest carbon price, provided the cap tightens over time and a portion of the auctioned revenues are reinvested in other emissions-reduction activities. Knowledge gaps exist in understanding the interaction of pricing instruments with other climate policy instruments and how governments manage these policies to achieve optimum emissions reductions with lower administrative costs.

Key policy insights

• Countries are learning from each other on ETS implementation.

• Administrative and regulatory structures of ETS jurisdictions appear to evolve and become more robust in every ETS analysed.

• A ‘double dividend’ for emissions reductions may also exist in cases where mitigation occurs as a result of the ETS policy and when auction revenues are reinvested in other emissions-reduction activities.

     

基于智能物联网技术的天津城市积水监测预警系统

通过智能物联网技术实时获取积水监测实况数据,利用天津市气象精细化格点预报产品和城市自动雨量观测站实况数据,以机器学习、神经网络模型和天津市城市内涝风险等级划分原理为基础,研究基于用户实时位置的城市内涝预报预警技术,研发天津市城市自动化积水监测预警系统。结果表明,该系统具备一定的城市内涝风险监测预警预报能力,并在2018—2020年多次重大天气过程中应用,积水深度预报结果与监测结果基本一致,应用数据表明验证结果良好,系统可以为政府防灾减灾决策、指挥调度提供精准、及时的气象数据支撑。     

基于e-Learning的测绘专业教学训练系统的设计与实现

介绍了e-Learning的概念及体系结构,结合测绘专业教育的实际需求,在e-Learning三层体系结构的基础上,给出e-Learning环境下测绘专业教学训练的系统设计及实现方案。