Transfer Learning from Deep Features for Remote Sensing and Poverty Mapping

The lack of reliable data in developing countries is a major obstacle to sustainable development, food security, and disaster relief. Poverty data, for example, is typically scarce, sparse in coverage, and labor-intensive to obtain. Remote sensing data such as high-resolution satellite imagery, on the other hand, is becoming increasingly available and inexpensive. Unfortunately, such data is highly unstructured and currently no techniques exist to automatically extract useful insights to inform policy decisions and help direct humanitarian efforts. We propose a novel machine learning approach to extract large-scale socioeconomic indicators from high-resolution satellite imagery. The main challenge is that training data is very scarce, making it difficult to apply modern techniques such as Convolutional Neural Networks (CNN). We therefore propose a transfer learning approach where nighttime light intensities are used as a data-rich proxy. We train a fully convolutional CNN model to predict nighttime lights from daytime imagery, simultaneously learning features that are useful for poverty prediction. The model learns filters identifying different terrains and man-made structures, including roads, buildings, and farmlands, without any supervision beyond nighttime lights. We demonstrate that these learned features are highly informative for poverty mapping, even approaching the predictive performance of survey data collected in the field.Comment: In Proc. 30th AAAI Conference on Artificial Intelligenc

Tile2Vec: Unsupervised representation learning for spatially distributed data

Geospatial analysis lacks methods like the word vector representations and pre-trained networks that significantly boost performance across a wide range of natural language and computer vision tasks. To fill this gap, we introduce Tile2Vec, an unsupervised representation learning algorithm that extends the distributional hypothesis from natural language -- words appearing in similar contexts tend to have similar meanings -- to spatially distributed data. We demonstrate empirically that Tile2Vec learns semantically meaningful representations on three datasets. Our learned representations significantly improve performance in downstream classification tasks and, similar to word vectors, visual analogies can be obtained via simple arithmetic in the latent space.Comment: 8 pages, 4 figures in main text; 9 pages, 11 figures in appendi

Health benefits and control costs of tightening particulate matter emissions standards for coal power plants - The case of Northeast Brazil.

Exposure to ambient particulate matter (PM) caused an estimated 4.2 million deaths worldwide in 2015. However, PM emission standards for power plants vary widely. To explore if the current levels of these standards are sufficiently stringent in a simple cost-benefit framework, we compared the health benefits (avoided monetized health costs) with the control costs of tightening PM emission standards for coal-fired power plants in Northeast (NE) Brazil, where ambient PM concentrations are below World Health Organization (WHO) guidelines. We considered three Brazilian PM10 (PMx refers to PM with a diameter under x micrometers) emission standards and a stricter U.S. EPA standard for recent power plants. Our integrated methodology simulates hourly electricity grid dispatch from utility-scale power plants, disperses the resulting PM2.5, and estimates selected human health impacts from PM2.5 exposure using the latest integrated exposure-response model. Since the emissions inventories required to model secondary PM are not available in our study area, we modeled only primary PM so our benefit estimates are conservative. We found that tightening existing PM10 emission standards yields health benefits that are over 60 times greater than emissions control costs in all the scenarios we considered. The monetary value of avoided hospital admissions alone is at least four times as large as the corresponding control costs. These results provide strong arguments for considering tightening PM emission standards for coal-fired power plants worldwide, including in regions that meet WHO guidelines and in developing countries

Second year technical report on-board processing for future satellite communications systems

Advanced baseband and microwave switching techniques for large domestic communications satellites operating in the 30/20 GHz frequency bands are discussed. The nominal baseband processor throughput is one million packets per second (1.6 Gb/s) from one thousand T1 carrier rate customer premises terminals. A frequency reuse factor of sixteen is assumed by using 16 spot antenna beams with the same 100 MHz bandwidth per beam and a modulation with a one b/s per Hz bandwidth efficiency. Eight of the beams are fixed on major metropolitan areas and eight are scanning beams which periodically cover the remainder of the U.S. under dynamic control. User signals are regenerated (demodulated/remodulated) and message packages are reformatted on board. Frequency division multiple access and time division multiplex are employed on the uplinks and downlinks, respectively, for terminals within the coverage area and dwell interval of a scanning beam. Link establishment and packet routing protocols are defined. Also described is a detailed design of a separate 100 x 100 microwave switch capable of handling nonregenerated signals occupying the remaining 2.4 GHz bandwidth with 60 dB of isolation, at an estimated weight and power consumption of approximately 400 kg and 100 W, respectively

First International Microgravity Laboratory

This colorful booklet presents capsule information on every aspect of the International Microgravity Laboratory (IML). As part of Spacelab, IML is divided into Life Science Experiments and Materials Science Experiments. Because the life and materials sciences use different Spacelab resources, they are logically paired on the IML missions. Life science investigations generally require significant crew involvement, and crew members often participate as test subjects or operators. Materials missions capitalize on these complementary experiments. International cooperation consists in participation by the European Space Agency, Canada, France, Germany, and Japan who are all partners in developing hardware and experiments of IML missions. IML experiments are crucial to future space ventures, like the development of Space Station Freedom, the establishment of lunar colonies, and the exploration of other planets. Principal investigators are identified for each experiment

Evidence-use and role of the superintendent in leading for learning: a case study of a small Illinois rural school district

Extensive research has been conducted on the role of school principals in promoting student learning, but there has been relatively little focus on the role of the central office administration, specifically the superintendent, as leaders for learning. The school district superintendent's office is often seen as a separate entity that is removed from everyday work in classrooms. Hough (2014) states that superintendents are often seen as too detached from the classroom to have any quantifiable impact on student academic performance; perhaps this assumption is due to the fact that the majority of the empirical evidence centers on the school level as the unit of study. Smith and O'Day (1991) explained that teachers and building leaders are the "initiators, designers, and directors of change efforts" (p. 235). However, the school superintendent, as the chief administrative officer of the school system, also has an important duty to facilitate, direct, and support classroom teaching and learning practices. This qualitative case study examined the practices of one exemplary Illinois rural school district that is engaged in a formalized evidence-use process as a lever for school reform. The school district superintendent’s leadership behaviors and practices were examined as he compiled, desegregated, and analyzed district data in collaboration with district and building personnel. The supposition of this study was the superintendent is uniquely positioned as the formally appointed head of the organization to lead and guide procedures and practices related to student learning. Gaining an understanding of the unique role of the rural superintendent while leading for learning included an examination of how evidence-use processes are structured and what systems and sub-units matter to evidence-use. Specifically, a focus of the study was the examination of the superintendent’s leadership choices and experiences while leading a district-wide reform process that centered on student learning, to gain an understanding of successful implementation strategies and potential obstacles in leading change, and to explore one promising lever—evidence-use—to increase student learning. The theoretical construct that informed this study is rooted in the Leadership for Learning Framework (Knapp et al., 2010) and is an appropriate lens for examining district improvement and leadership processes. The findings revealed the superintendent demonstrated behaviors and practices that facilitated and supported evidence-use process and subsequently the district engaged in practices that promoted professional, student, and systems learning. The findings revealed four themes that included the superintendent focused on learning, established high expectations for learning, modeled evidence as a medium for leading improvements, and "generated will" with stakeholders through the development of good relationships. Next, four key themes emerged from the data regarding what matters in effective evidence-use processes that included the district focusing on collaboration, building staff members' capacity as educators through meaningful professional development and leadership opportunities, establishing a mutually reliant information exchange relationship, and engaging in professional reflection. Finally, the findings revealed three key themes related to evidence-use barriers and constraints that inhibit effective evidence-use process that included: (a) optimal assessment conditions, (b) striking the right balance in testing, and (c) communicating findings in a productive manner. Implications from this study focused upon the superintendent facilitating Leadership for Learning action steps, distributing leadership, collaborating, and building capacity through the evidence-use processes to promote professional, student, and system learning. Recommendations for practice, policy and future research are presented to advance rural district leaders of learning utilization of one strategic lever of school reform—evidence-use processes focused upon improving student performance

Herschel Observations of the T Cha Transition Disk: Constraining the Outer Disk Properties

T Cha is a nearby (d similar to 100 pc) transition disk known to have an optically thin gap separating optically thick inner and outer disk components. Huelamo et al. recently reported the presence of a low-mass object candidate within the gap of the T Cha disk, giving credence to the suspected planetary origin of this gap. Here we present the Herschel photometry (70, 160, 250, 350, and 500 mu m) of T Cha from the "Dust, Ice, and Gas in Time" Key Program, which bridges the wavelength range between existing Spitzer and millimeter data and provide important constraints on the outer disk properties of this extraordinary system. We model the entire optical to millimeter wavelength spectral energy distribution (SED) of T Cha (19 data points between 0.36 and 3300 mu m without any major gaps in wavelength coverage). T Cha shows a steep spectral slope in the far-IR, which we find clearly favors models with outer disks containing little or no dust beyond similar to 40 AU. The full SED can be modeled equally well with either an outer disk that is very compact (only a few AU wide) or a much larger one that has a very steep surface density profile. That is, T Cha's outer disk seems to be either very small or very tenuous. Both scenarios suggest a highly unusual outer disk and have important but different implications for the nature of T Cha. Spatially resolved images are needed to distinguish between the two scenarios.DIGIT Herschel Open Time Key ProgramNASAAlexander von Humboldt FoundationEuropean CommissionAgence Nationale pour la Recherche of France PERG06-GA-2009-256513, ANR-07-BLAN-0221, ANR-2010-JCJC-0504-01CNRS/INSU, FranceAstronom