Search results for "computers"
showing 10 items of 3243 documents
Residual errors in ASTER temperature and emissivity standard products AST08 and AST05
2011
Abstract Land surface temperature and emissivity are independent variables, and the thermal-infrared spectral radiance measured in remote sensing is dependent on both. Therefore the inverse Planck equation is under-determined, with two unknowns and a single measurement. Practical inversion algorithms designed to calculate temperature and emissivity from the measurements cannot do a perfect job of separation, and recovered temperature and emissivity may co-vary. For ASTER images, validation studies of recovered temperature and emissivity, regarded individually, have shown that they are within the precision and accuracy limits predicted in designing the ASTER TES algorithm used to calculate …
Mapping landscape canopy nitrogen content from space using PRISMA data
2021
Abstract Satellite imaging spectroscopy for terrestrial applications is reaching maturity with recently launched and upcoming science-driven missions, e.g. PRecursore IperSpettrale della Missione Applicativa (PRISMA) and Environmental Mapping and Analysis Program (EnMAP), respectively. Moreover, the high-priority mission candidate Copernicus Hyperspectral Imaging Mission for the Environment (CHIME) is expected to globally provide routine hyperspectral observations to support new and enhanced services for, among others, sustainable agricultural and biodiversity management. Thanks to the provision of contiguous visible-to-shortwave infrared spectral data, hyperspectral missions open enhanced …
Active Learning Methods and Strategies to Improve Student Conceptual Understanding: Some Considerations from Physics Education Research
2020
Active learning methods and strategies are credited to be an important means for the development of student cognitive skills. This paper describes some forms of active learning common in Physics Education and briefly introduces some of the pedagogical and psychological theories on the basis of active learning. Then, some evidence for active learning effectiveness in developing students’ critical cognitive skills and improving their conceptual understanding are examined. An example study regarding the effectiveness of an Inquiry-based learning approach in helping students to build mechanisms of functioning and explicative models, and to identify common aspects in apparently different phenome…
Educating to inspire active learning approaches in mathematics in Norwegian universities
2021
This is a report of an analysis of some of the data generated by a national survey of teaching approaches used in higher education mathematics courses. The overall purpose of the survey was to explore how widespread is the use of teaching approaches that might promote students’ active learning of mathematics. The paper includes a brief presentation of the authors meaning of the expression “teaching actions that have the potential to promote active learning”. The analysis focuses on the responses of 95 lecturers working in 13 Norwegian HE institutions. The goal is to expose underlying patterns in lecturers’ responses to questions about the teaching actions they may incorporate in their pract…
Applications of a remote sensing-based two-source energy balance algorithm for mapping surface fluxes without in situ air temperature observations
2012
Abstract The two-source energy balance (TSEB) model uses remotely sensed maps of land–surface temperature (LST) along with local air temperature estimates at a nominal blending height to model heat and water fluxes across a landscape, partitioned between dual sources of canopy and soil. For operational implementation of TSEB, however, it is often difficult to obtain representative air temperature data that are compatible with the LST retrievals, which may themselves have residual errors due to atmospheric and emissivity corrections. To address this issue, two different strategies in applying the TSEB model without requiring local air temperature data were tested over a typical Mediterranean…
A Hierarchical Detection and Response System to Enhance Security Against Lethal Cyber-Attacks in UAV Networks
2018
International audience; Unmanned aerial vehicles (UAVs) networks have not yet received considerable research attention. Specifically, security issues are a major concern because such networks, which carry vital information, are prone to various attacks. In this paper, we design and implement a novel intrusion detection and response scheme, which operates at the UAV and ground station levels, to detect malicious anomalies that threaten the network. In this scheme, a set of detection and response techniques are proposed to monitor the UAV behaviors and categorize them into the appropriate list (normal, abnormal, suspect, and malicious) according to the detected cyber-attack. We focus on the m…
Utility-based resource allocations in multi-hop wireless networks
2011
It is well known that CSMA (Carrier Sense Multiple Access) protocols exhibit very poor performance in case of multi-hop transmissions, because of inter-link interference due to imperfect carrier sensing. Since ad-hoc networks based on multihop packet deliveries are becoming more and more common in different application and networking scenarios, different medium access control extensions are currently considered for improving the channel utilization efficiency. In this paper, we propose a simple approach based on preallocating temporal slots in which different sets of nodes are allowed to contend for the channel access, which can significantly improve CSMA performance with limited signaling …
Symmetry function in gait pattern analysis in patients after unilateral transfemoral amputation using a mechanical or microprocessor prosthetic knee
2021
AbstractBackgroundAbove-knee amputations (AKAs) contribute to gait asymmetry. The level of asymmetry is affected by the type of knee prosthetic module. There is limited evidence suggesting that more technically advanced solutions (microprocessor modules; MicPK) are superior to less advanced ones (mechanical modules; MechPK). The study aimed to evaluate the variable range of hip and pelvic joint movements during gait and look for differentiating areas with an increased level of asymmetry of the gait cycle in individuals who underwent an AKA and are equipped with MicPK or MechPK.MethodsTwenty-eight individuals participated in the study; 14 were assigned to a study group of individuals who und…
Momentary Affect Predicts Bodily Movement in Daily Life: An Ambulatory Monitoring Study
2010
There is converging evidence that physical activity influences affective states. It has been found that aerobic exercise programs can significantly diminish negative affect. Moreover, among healthy individuals, moderate levels of physical activity seem to increase energetic arousal and positive affect. However, the predictive utility of affective states for bodily movement has rarely been investigated. In this study, we examined whether momentarily assessed affect is associated with bodily movement in everyday life. Using a previously published data set (Schwerdtfeger, Eberhardt, & Chmitorz, 2008), we reanalyzed 12-hr ecological momentary assessment (EMA) data from 124 healthy volunteer…
Exploring the Enjoyment of Playing Browser Games
2009
Browser games--mostly persistent game worlds that can be used without client software and monetary cost with a Web browser--belong to the understudied digital game types, although they attract large player communities and motivate sustained play. The present work reports findings from an online survey of 8,203 players of a German strategy browser game ("Travian"). Results suggest that multiplayer browser games are enjoyed primarily because of the social relationships involved in game play and the specific time and flexibility characteristics ("easy-in, easy-out"). Competition, in contrast, seems to be less important for browser gamers than for users of other game types. Findings are discuss…