Spectral Variability of LANDSAT-4 Thematic Mapper And Multispectral Scanner Data for Selected Crop And Forest Cover Types

The performance of both the Landsat-4 TM and MSS sensors is evaluated through the analysis of image and digital data simultaneously acquired over agricultural and forestry study sites in California. Spectral statistics extracted for selected cover types include band means, variances, coefficients of variation, range values, skewness, kurtosis, and covariance and correlation matrices. Spectral characteristics are evaluated through analysis of these statistics and interpretation of image products. Image products are used to visually represent significant spectral variations between the TM bands. Significant results include: 1) the overall spectral, spatial, and radiometric quality of the TM data are excellent; 2) discrimination of crop types on single-date image data is significantly improved by the addition of the first short-wave infrared band (TM5); 3) the thermal infrared data (TM6) allows the discrimination of agricultural and forestry cover types based on differences in their radiant temperature responses; and 4) the higher TM spatial resolution (28.5 m versus 57 m) provides the ability to discriminate small agricultural fields and boundaries, forest stand boundary conditions, road and stream networks in rough terrain, and small clearings resulting from various forest management practices.     

Copper@ZIF-8 Core-Shell Nanowires for Reusable Antimicrobial Face Masks

SARS-CoV-2 and other respiratory viruses spread via aerosols generated by infected people. Face masks can limit transmission. However, widespread use of disposable masks consumes tremendous resources and generates waste. Here, a novel material for treating blown polypropylene filtration media used in medical-grade masks to impart antimicrobial activity is reported. To produce thin copper@ZIF-8 core-shell nanowires (Cu@ZIF-8 NWs), Cu NWs are stabilized using a pluronic F-127 block copolymer, followed by growth of ZIF-8 to obtain uniform core-shell structures. The Cu@ZIF-8 NWs are applied to filtration media by dip coating. Aerosol filtration efficiency decreases upon exposure to ethanol (solvent for dip-coating), but increases with addition of Cu@ZIF-8 NWs. Cu@ZIF-8 NWs shows enhanced antibacterial activity, compared to Cu NWs or ZIF-8 alone, against Streptococcus mutans and Escherichia coli. Antiviral activity against SARS-CoV-2 is assayed using virus-infected Vero E6 cells, demonstrating 55% inhibition of virus replication after 48 h by 1 µg of Cu@ZIF-8 NWs per well. Cu@ZIF-8 NWs’ cytotoxicity is tested against four cell lines, and their effect on inflammatory response in A549 cells is examined, demonstrating good biocompatibility. This low-cost, scalable synthesis and straightforward deposition of Cu@ZIF-8 NWs onto filter media has great potential to reduce disease transmission, resource consumption, and environmental impact of waste.     

RERBEE: robust efficient registration via bifurcations and elongated elements applied to retinal fluorescein angiogram sequences

We present RERBEE (robust efficient registration via bifurcations and elongated elements), a novel feature-based registration algorithm able to correct local deformations in high-resolution ultra-wide field-of-view (UWFV) fluorescein angiogram (FA) sequences of the retina. The algorithm is able to cope with peripheral blurring, severe occlusions, presence of retinal pathologies and the change of image content due to the perfusion of the fluorescein dye in time. We have used the computational power of a graphics processor to increase the performance of the most computationally expensive parts of the algorithm by a factor of over × 1300, enabling the algorithm to register a pair of 3900 × 3072 UWFV FA images in 5-10 min instead of the 5-7 h required using only the CPU. We demonstrate accurate results on real data with 267 image pairs from a total of 277 (96.4%) graded as correctly registered by a clinician and 10 (3.6%) graded as correctly registered with minor errors but usable for clinical purposes. Quantitative comparison with state-of-the-art intensity-based and feature-based registration methods using synthetic data is also reported. We also show some potential usage of a correctly aligned sequence for vein/artery discrimination and automatic lesion detection.     

A report on HIPERLAN standardization

HIPERLAN is the new European standard for radio LANs currently being formulated by ETSI RES10 for operation at 5 GHz and 17 GHz. It will be suitable for radio replacement of wired LANs and for ad hoc networking providing a user data rate of 10–20 Mbit/s. This paper is a review of the work of ETSI RES10 on the formulation of the HIPERLAN standard. The origins of ETSI RES10 are documented. The targets set for HIPERLAN and the problems in achieving these targets are discussed. The paper reviews the technical arguments for and against the proposed solutions to these problems, concentrating on the design of the transmission scheme and the channel access mechanism. The discussions leading to significant decisions about the standard are summarized. If the FCC in the United States of America allocate the equivalent 5 GHz band to unlicensed wireless LAN systems, many of these discussions will be revisited for future standards in this band. The paper will be of interest to anyone in academia or industry wishing to be brought quickly up to date with the state of the standard in order to focus their research or development activities. The paper also gives a general insight into the technical side of the standards formulation process in ETSI.     

Toward a Magnesium‐Iodine Battery

The quest for new electrolyte and cathode materials is a crucial point for beyond‐lithium‐ion energy storage systems. Following this, an electrolyte for secondary magnesium batteries based on a new iodoaluminate ionic liquid and δ‐MgI₂ is reported. Promising electrochemical performance in terms of Mg plating‐stripping, coulombic efficiency, and conductivity, demonstrates the potential of this iodine‐based system for future Mg secondary batteries.     

平台2015:Intel处理器及平台在下一个十年的演化

毫无疑问,近年来计算技术取得了长足的进步。但是,在未来的十年,主流计算技术中新的工作量、使用模式的出现及变化对未来的计算平台提出的要求,与过去十年所取得的进展也差不多,这些巨大的要求包括:更高的性能、更低的功率密度、更好的功能可扩展性。倘若出现这些使用计算机的震撼性的变化,我们怎样定义和构架未来的计算平台,就将不得不做出引人注目的改变。要整体地理解和满足的,不仅仅有计算的需要,而且还有接口以及系统基础设施的需要。Intel对这三个基础平台要素的演化的长期设想,以及驱动演化的架构的创新和核心能力,即是我们称之为平台2015(Platform2015)的内容。除了考察相关的趋势、使用、平台处理含意之外,本文将集中在平台2015的计算单元,描述Intel微处理器架构在未来十年的演化。     

Dynamic Base Station Selection for Personal Communication Systems with Distributed Control Schemes

Distributed control schemes allow base stations in personal communication systems to be placed at locations corresponding to high expected traffic. This flexible base station placement creates significant overlapping coverage areas that can be utilized to improve system performance [1]. A new technique for dynamic base station selection in systems with overlapping cells is considered and its effect on traffic performance is characterized. The technique realizes robust performance for personal communication systems in fluctuating and heavily tapered traffic. A mathematical analysis based on a state transition model is used to evaluate performance of a system that employs the proposed technique. The results indicate that improved blocking probability and carried traffic performance are obtainable. Computer simulations were undertaken confirm the analytical results.     

Volume rendering of segmented image objects

This paper describes a new method of combining ray-casting with segmentation. Volume rendering is performed at interactive rates on personal computers, and visualizations include both "superficial" ray-casting through a shell at each object's surface and "deep" ray-casting through the confines of each object. A feature of the approach is the option to smoothly and interactively dilate segmentation boundaries along all axes. This ability, when combined with selective "turning off" of extraneous image objects, can help clinicians detect and evaluate segmentation errors that may affect surgical planning. We describe both a method optimized for displaying tubular objects and a more general method applicable to objects of arbitrary geometry. In both cases, select three-dimensional points are projected onto a modified z buffer that records additional information about the projected objects. A subsequent step selectively volume renders only through the object volumes indicated by the z buffer. We describe how our approach differs from other reported methods for combining segmentation with ray-casting, and illustrate how our method can be useful in helping to detect segmentation errors.     

Spectral study and classification of worldwide locations considering several multijunction solar cell technologies

Multi‐junction solar cells are widely used in high‐concentration photovoltaic systems (HCPV) attaining the highest efficiencies in photovoltaic energy generation. This technology is more dependent on the spectral variations of the impinging Direct Normal Irradiance (DNI) than conventional photovoltaics based on silicon solar cells and consequently demands a deeper knowledge of the solar resource characteristics. This article explores the capabilities of spectral indexes, namely, spectral matching ratios (SMR), to spectrally characterize the annual irradiation reaching a particular location on the Earth and to provide the necessary information for the spectral optimization of a MJ solar cell in that location as a starting point for CPV module spectral tuning. Additionally, the relationship between such indexes and the atmosphere parameters, such as the aerosol optical depth (AOD), precipitable water (PW), and air mass (AM), is discussed using radiative transfer models such as SMARTS to generate the spectrally resolved DNI. The network of ground‐based sun and sky‐scanning radiometers AErosol RObotic NETwork (AERONET) is exploited to obtain the atmosphere parameters for a selected bunch of 34 sites worldwide. Finally, the SMR indexes are obtained for every location, and a comparative analysis is carried out for four architectures of triple junction solar cells, covering both lattice match and metamorphic technologies. The differences found among cell technologies are much less significant than among locations. Copyright © 2016 John Wiley & Sons, Ltd.