3,200 research outputs found
The Aresys FF-SAR Service for Cryosat-2 at ESA GPOD
No full textThe Fully-Focused SAR (FF-SAR) processing, introduced in Egido and Smith (2016) allows obtaining a maximum resolution of 0.5 m in the along-track direction. It provides significant benefits for inland water altimetry investigations allowing the successful investigation of very small rivers and canals (Kleinherenbrink, 2020) that are typically harder to be analysed by using unfocused Delay-Doppler SAR (DD-SAR) data (about 300 m resolution in the along-track direction).In its development, two major limitations were associated with the FF-SAR processing: 1) the presence of evenly spaced high sidelobes in the Point Target Response (PTR) due to the closed-loop burst mode implemented in Sentinel-3 & Cryosat-2 altimeter payloads, used for initial FF-SAR investigations, and 2) the heavy computational burden with respect to the unfocused DD-SAR processing. The first limitation can be overcome by designing the radar system differently adopting an open-loop transmission scheme as, for instance, the one implemented in the altimeter payload of the Sentinel-6 Michael Freilich mission, launched on 21 November 2020. The second limitation has been addressed in research works following Egido and Smith (2016) indicating that an improvement in terms of computational burden can be achieved by adopting algorithms in the frequency domain (Guccione et al., 2018).Being the role of FF-SAR for future inland water altimetry well understood, along with the possibility to see it implemented with reduced drawbacks during the Sentinel-6 Michael Freilich mission, a collaboration has started between the ESA GPOD Team, already hosting the successful SARvatore services portfolio for unfocused SAR & SARin altimetry, and Aresys. Aresys has developed a generic FF-SAR prototype processor, that is able to process data acquisition from different instruments and exploiting the frequency-domain Omega-K algorithm (Guccione et al., 2018 & Scagliola et al., 2018). The Aresys's FFSAR prototype processor for CryoSat-2 allows users to process, on line and on demand, low-level CryoSat FBR products in SAR mode up to FF-SAR Level-1 products with self-customized options. Additionally a wide set of processing parameters is configurable, allowing as an example to select the along-track resolution or to obtain FFSAR multilooked waveforms at the desired posting rate. The collaboration led to the creation of a new service for the processing of CryoSat Baseline D data in FF-SAR mode. Users will be able to select the following options: 1) range oversampling factor, 2) bandwidth factor (responsible for the along-track resolution value) and 3) multilook posting rate (1Hz-500Hz). Geophysical corrections and L2 estimates from both a threshold peak retracker and an ALES-like subwaveform retracker are part of the output package. In preliminary open ocean analyses, very good results on SSH noise have been obtained by the ALES-like subwaveform retracker.In this presentation, the Aresys FF-SAR prototype processor is described and the outcome of some preliminary validation activities, performed by a group of altimetry researchers, is reported. The service is scheduled to open to all GPOD/SARvatore users in the first semester of 2021. Future evolutions should include the extension of the service to Sentinel-3 and Sentinel-6 data.Astrodynamics & Space Mission
Collective Organization Behaviors of Multi‐Cell Systems Induced by Engineered ECM‐Cell Mechanical Coupling
No full textCells in vivo are surrounded by fibrous extracellular matrix (ECM), which can mediate the propagation of active cellular forces through stressed fiber bundles and regulate various biological processes. However, the mechanisms for multi-cellular organization and collective dynamics induced by cell-ECM mechanical couplings, which are crucial for the development of novel ECM-based biomaterial for cell manipulation and biomechanical applications, remain poorly understood. Herein, the authors design an in vitro quasi-3D experimental system and demonstrate a transition between spreading and aggregating in collective organizational behaviors of discrete multi-cellular systems, induced by engineered ECM-cell mechanical coupling, with the observed phenomena and underlying mechanisms differing fundamentally from those of cell monolayers. During the process of collective cell organization, the collagen substrate undergoes reconstruction into a dense fiber network structure, which is correlated with local cellular density and consistent with observed enhanced cells' motility; and the weakening of fiber bundle formation within the hydrogel reduces cells' movement. Moreover, cells can respond to the curvature and shape of the original cell population and form different aggregation patterns. These results elucidate important physical factors involved in collective cell organization and provide important references for potential applications of biomaterials in new therapies and tissue engineering
The Devil's altar? : crime and the early modern public house
No full textWas the early modern public house really such a dangerous place, as Puritan preachers (and many historians) suggested? This article discusses offences by publicans and patrons. It argues that the evidence for crime needs to be carefully contextualised and that taverns could stabilise as well as threaten the social order
Pengaruh Variasi Jumlah Cooling Fan Terhadap Unjuk Kerja Solar Cell
No full textPolycrystalline solar panels have a weakness where at temperatures of more than 25oC their performance decreases, the city of Pekanbaru has an average temperature of 30oC which is higher than the optimal temperature of polycrystalline solar panels which causes the performance of solar panels to decrease. For this reason, it is necessary to make an effort so that the performance of the solar panel can increase, the effort made is by adding a cooling fan to reduce the temperature on the solar panel. This study aims to obtain the effect of adding the best cooling fan to help the performance of solar panels. This research was conducted using various cooling fans, namely using 1cooling fan, 2 cooling fan, 3 cooling fan and 4 cooling fan. From the results of the study, it was found that the performance test and analysis carried out showed that there was an influence on the addition of a cooling fan to the performance of the solar panel, the best was obtained using Variation 4 cooling fan, which got an open current voltage (Voc) of 17.94 V, short-voltage. circuit current (Isc) of 0.55 A, maximum power (Pmax) of 7.15 W, Fill factor (FF) of 0.72, output power (Pout) of 7.15 W, and efficiency (η) of 9 ,86%
Flexible time–space network formulation and hybrid metaheuristic for conflict-free and energy-efficient path planning of automated guided vehicles
No full textOperations of Automated Guided Vehicles (AGVs) are desired to be more energy-efficient while maintaining high transport productivity, motivated by the green production requirements. This paper investigates a new energy-efficient planning problem for determining conflict-free paths of the AGVs in its transport roadmap. In this problem, the vehicle path and transport time in the roadmap are jointly optimized, based on a flexible time–space network (FTSN). We provide the mathematical problem formulation of the energy-efficient path planning problem. The resulting optimization problem is proved to be a non-convex mixed-integer nonlinear programming which is computationally intractable. We further propose a hybrid metaheuristic that integrates the genetic algorithm and estimation of the distribution algorithm to improve its computational efficiency. Numerical results show the effectiveness of the developed algorithm based on the FTSN framework, compared to the existing metaheuristics, the conventional path planning method, and a commercial solver. The proposed method has a wide application in improving energy use of material handling, providing a guiding significance on promoting cleaner production of flexible manufacturing systems.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Transport Engineering and Logistic
Optimal Configuration of Omega-Kappa FF-SAR Processing for Specular and Non-Specular Targets in Altimetric Data: The Sentinel-6 Michael Freilich Study Case
No full textIn this study, the full-focusing (FF) algorithm is reviewed with the objective of optimizing it for processing data from different types of surfaces probed in altimetry. In particular, this work aims to provide a set of optimal FF processing parameters for the Sentinel-6 Michael Freilich (S6-MF) mission. The S6-MF satellite carries an advanced radar altimeter offering a wide range of potential FF-based applications which are just beginning to be explored and require prior optimization of this processing. In S6-MF, the Synthetic Aperture Radar (SAR) altimeter acquisitions are known to be aliased in the along-track direction. Depending on the target, aliasing can be tolerated or may be a severe impairment to provide the level of performance expected from FF processing. Another key aspect to consider in this optimization study is the unprecedented resolution of the FF processing, which results in a higher posting rate than the standard SAR processing. This work investigates the relationship between posting rate and noise levels and provides recommendations for optimal algorithm configurations in various scenarios, including transponder, open ocean, and specular targets like sea-ice and inland water scenes. The Omega–Kappa (WK) algorithm, which has demonstrated superior CPU efficiency compared to the back-projection (BP) algorithm, is considered for this study. But, unlike BP, it operates in the Doppler frequency domain, necessitating further precise spectral and time domain settings. Based on the results of this work, real case studies using S6-MF acquisitions are presented. We first compare S6-MF FF radargrams with Sentinel-1 (S1) images to showcase the potential of optimally configured FF processing. For highly specular surfaces such as sea-ice, distinct techniques are employed for lead signature identification. S1 relies on image-based lineic reconstruction, while S6-MF utilizes phase coherency of focalized pulses for lead detection. The study also delves into two-dimensional wave spectra derived from the amplitude modulation of image/radargrams, with a focus on a coastal example. This case is especially intriguing, as it vividly illustrates different sea states characterized by varying spectral peak positions over time.Astrodynamics & Space Mission
Qian shou qian yan [guan shi yinpu sa guang da yuan man wu ai da bei xin] tuo luo ni jing 千 手 千 眼 [觀 世 音 菩 蕯 廣大 圓 满 無 礙 大 悲 心] 陁 羅 尼 經 trad. de Qie fan da mo 伽梵 達 摩 (Bhagavaddharma).
No full textQian shou qian yan guanshi yin pu sa guang da yuan man wu ai da bei xin tuo luo ni jing 千 手 千 眼 觀 世 音菩 薩 廣 大 圓 滿 無 礙 大 悲 心 陁 羅 尼 經, trad. de BhagavaddharmaQian shouqian yan tuo luo ni jing 千 手 千 眼 陁 羅 尼 經, cf. Qian shou qian yan guan shi yinpu sa guang da yuan man wu ai da bei xin tuo luo ni jing.Nīlakaṇṭha-sūtraNumérisation effectuée à partir d'un document original.En 1 j.,déb. manque. Paragraphes présentés dans un ordre différent de celui deT . 1060, vol. 20 : Ff. 1à 3 (col. 15) : T . 1060, pp.109 c 7-110 a 17 ; Ff. 3 (col. 15) à 5 (col. 11) : T . 1060, p. 111 a 4 b 12 ; Ff.5 (col. 12) à 6 (col. 6) : T .1060, p. 111 c 2-19 (fin du texte et titre complet) ; Ff. 6 (col. 7) à 7(col. 2) : T . 1060, p. 111 b13-c 2 ; Ff. 7 (col. 3) à 10 (col. 9) : T . 1060, pp. 110 a 17-111 a 4. Cette dernière partiecorrespond aussi à la première moitié du texte du Qianshou qian yan guan shi yin pu sa zhi bing he yao jing 千 手 千 眼 觀 世 音 菩 蕯治 病 合 藥 經, T . 1059, pp. 103c-104 c 19. Titre final : Qian shou qian yan tuoluo ni jing. Sous ce titre, nom du traducteur et, à gauche, colophon : «Copie due au fidèle Wang Chong yi 王 崇 藝, 27e année kaiyuan (739). » Bonne écr. call., grands car., traits assez épais.Quelques additions, ratures et corrections. 20 ou 21 col. par f., 16 à 20 car.par col. Quelques notes, fan qie et indicationsnumériques en petits car. sur 1 col. ou sur col. dédoublées. Marges sup. 2,2 à3,5 cm, inf. 1,9 à 3,7 cm, tracées à main levée (ff. 1-6), puis non tracées.Traces de réglure par pliage
Fast FF-to-FFPE Whole Slide Image Translation via Laplacian Pyramid and Contrastive Learning
No full textFormalin-Fixed Paraffin-Embedded (FFPE) and Fresh Frozen (FF) are two major types of histopathological Whole Slide Images (WSIs). FFPE provides high-quality images, however the acquisition process usually takes 12 to 48 h, while FF with relatively low-quality images takes less than 15 min to acquire. In this work, we focus on the task of translating FF to FFPE style (FF2FFPE), to synthesize FFPE-style images from FF images. However, WSIs with giga-pixels impose heavy constraints on computation and time resources. To address these issues, we propose the fastFF2FFPE for translating FF into FFPE-style efficiently. Specifically, we decompose FF images into low- and high-frequency components based on the Laplacian Pyramid, wherein the low-frequency component at low resolution is transformed into FFPE-style with low computational cost, and the high-frequency component is used for providing details. We further employ contrastive learning to encourage similarities between original and output patches. We conduct FF2FFPE translation experiments on The Cancer Genome Atlas (TCGA) Glioblastoma Multiforme (GBM) and Lung Squamous Cell Carcinoma (LUSC) datasets, and verify the efficacy of our model on Microsatellite Instability prediction in gastrointestinal cancer. The code and models are released at https://github.com/hellodfan/fastFF2FFPE
Fluticasone furoate and vilanterol for the treatment of chronic obstructive pulmonary disease
No full textIntroduction: Current national and international guidelines for the management of patients with stable
chronic obstructive pulmonary disease (COPD) recommend the use of inhaled long-acting
bronchodilators, inhaled glucocorticoids and their combinations for maintenance treatment of moderate
to severe stable COPD.
Areas covered: The role of fluticasone furoate (FF) and vilanterol (VI) once daily combination therapy
for the regular treatment of patients with stable COPD is discussed in this review.
Expert commentary: The regular treatment of moderate to severe stable COPD with once daily FF/VI
combination therapy is effective, as seen in in several large placebo-controlled clinical trials involving
many thousands of patients. FF/VI improved lung function, decreased respiratory symptoms and
deceased the number of COPD exacerbations, including COPD-related hospitalizations. FF/VI
combination therapy has also been approved for this indication in most countries. The use of this
combination therapy may significantly decrease the economic costs for some National Health Services
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