RESUMEN
Identifying road surface types (paved or unpaved) can ensure road vehicle safety, reduce energy consumption, and promote economic development. Existing studies identified road surface types by using sensors mounted on mobile devices and high-resolution satellite images that are not openly accessible, which makes it difficult to apply them to large-scale (e.g., national or regional) study areas. Addressing this issue, this study developed a dataset of road surface types (paved and unpaved) for the national road network of Kenya, containing 1,267,818 road segments classified as paved or unpaved. To accomplish this, this study proposes a method that integrates crowdsourced geographic data (OpenStreetMap) and Google satellite imagery to identify road surface types. The accuracy, recall, and F1 score of the method were all above 0.94, validating the effectiveness of the method. The data sources of the method are freely available, and the method may be applied to other countries and regions. The dataset developed based on the method can provide data support and decision support for local governments to improve road infrastructure.
RESUMEN
Time-resolved illumination provides rich spatiotemporal information for applications such as accurate depth sensing or hidden geometry reconstruction, becoming a useful asset for prototyping and as input for data-driven approaches. However, time-resolved illumination measurements are high-dimensional and have a low signal-to-noise ratio, hampering their applicability in real scenarios. We propose a novel method to compactly represent time-resolved illumination using mixtures of exponentially modified Gaussians that are robust to noise and preserve structural information. Our method yields representations two orders of magnitude smaller than discretized data, providing consistent results in such applications as hidden-scene reconstruction and depth estimation, and quantitative improvements over previous approaches.
RESUMEN
A series of 2,4-disubstituted 1,2,4-triazole-3-ones 4 were prepared via an iodine-DMSO-promoted three-component reaction of formaldehyde, amines and hydrazines in moderate yields.
Asunto(s)
Yodo , Aminas , Dimetilsulfóxido , Hidrazinas , Yoduros , Estructura MolecularRESUMEN
The palladium-catalyzed asymmetric [4 + 3] cycloaddition of a sulfonyl-trimethylenemethane (TMM) donor with azadienes furnished various sulfonyl-fused azepines with exclusive regioselectivities and excellent stereoselectivities (up to >20:1 dr, >99% ee) in high yields (up to 93%). Moreover, sulfone, serving as a transient activating group of the TMM species, can be easily removed from the cycloadducts to provide the structurally simple fused azepines with excellent enantioselectivities. This strategy demonstrates sulfonyl-TMM as an effective surrogate of naked TMM with high reactivity, exclusive regioselectivity, and excellent stereoselectivity.
RESUMEN
Exploiting temporal information of light propagation captured at ultra-fast frame rates has enabled applications such as reconstruction of complex hidden geometry and vision through scattering media. However, these applications require high-dimensional and high-resolution transport data, which introduces significant performance and storage constraints. Additionally, due to different sources of noise in both captured and synthesized data, the signal becomes significantly degraded over time, compromising the quality of the results. In this work, we tackle these issues by proposing a method that extracts meaningful sets of features to accurately represent time-resolved light transport data. Our method reduces the size of time-resolved transport data up to a factor of 32, while significantly mitigating variance in both temporal and spatial dimensions.
RESUMEN
The palladium-catalyzed asymmetric [4+3] cyclization of trimethylenemethane donors with benzofuran-derived azadienes furnishes chiral benzofuro[3,2-b]azepine frameworks in high yields (up to 98 %) with exclusive regioselectivities and excellent stereoselectivities (up to >20:1â d.r., >99 %â ee). This catalytic asymmetric [4+3] cyclization of Pd-trimethylenemethane can enrich the arsenal of Pd-TMM reactions in organic synthesis. In addition, this strategy provides an alternative approach to chiral azepines by a transition-metal-catalyzed asymmetric [4+3] cyclization.
