Wide-field compensation of monochromatic eye aberrations: expected performance and design trade-offs

AbstractAn important region of the electromagnetic spectrum for astrophysics is the hard X- and gamma ray band between 10 keV and a few MeV, where several processes occur in a wide variety of objects and with different spatial distribution and time scales. In order to fulfill the observational requirements in this energy range and taking into account the opportunities given by small/medium size missions (e.g. on the ISS), we have proposed a compact, wide field camera based on a thick (1 cm) position sensitive CdTe detector (PSD). The detector is made of an array of 128×96 CdTe microspectrometers with a pixel size of 2×2 mm2. The basic element of the PSD is the linear module that is an independent detection unit with 32 CdTe crystals and monolithic front-electronics (ASIC) supported by a thin (300 μm) ceramic layer. The expected performance of the PSD over the operative energy range and some of the required ASIC functionality are presented and discussed.

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Trade-Off Analysis for the Design of a High Performance Hydrostatic Actuation System

10.1115/imece2000-1981 ◽

2000 ◽

Author(s):

S. R. Habibi

Keyword(s):

Mathematical Modeling ◽

Quadratic Programming ◽

High Performance ◽

Design Parameters ◽

Mathematical Functions ◽

Trade Off ◽

Actuation System ◽

Trade Offs ◽

Expected Performance ◽

Dominant Design

Abstract This paper considers the design of a high performance hydrostatic actuation system referred to as the ElectroHydraulic Actuator (EHA). The expected performance of EHA and its dominant design parameters are identified by using mathematical modeling. The design parameters are classified into Direct and Indirect categories based on the measure of their accessibility to the designer. The Direct parameters are directly quantifiable and, can be linked to the performance of EHA through a set of mathematical functions. A prototype of EHA has been produced and described. The mathematical functions linking performance to design parameters are used to investigate design trade-offs. Design improvements to the prototype are suggested by using constrained quadratic programming.

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Design and Analysis of a Next-Generation Wide Field-of-View Earth Radiation Budget Radiometer

Remote Sensing ◽

10.3390/rs12030425 ◽

2020 ◽

Vol 12 (3) ◽

pp. 425 ◽

Cited By ~ 2

Author(s):

Luca Schifano ◽

Lien Smeesters ◽

Thomas Geernaert ◽

Francis Berghmans ◽

Steven Dewitte

Keyword(s):

Mechanical Design ◽

Thermal Analyses ◽

Field Of View ◽

Radiation Budget ◽

Radiative Energy ◽

Wide Field ◽

Expected Performance ◽

Wide Field Of View ◽

Earth Radiation Budget ◽

Earth Radiation

Climate on Earth is determined by the Earth Radiation Budget (ERB), which quantifies the incoming and outgoing radiative energy fluxes. The ERB can be monitored by non-scanning wide field-of-view radiometers, or by scanning narrow field-of-view radiometers. We propose an enhanced design for the wide field-of-view radiometer, with as key features the use of a near-spherical cavity to obtain a uniform angular sensitivity and the integration of the shuttered electrical substitution principle, eliminating long term drifts of the radiometer and improving its time response. The target absolute accuracy is 1 W/m 2 and the target stability is 0.1 W/m 2 per decade for the measurement of the total outgoing Earth’s radiation. In order to increase the spatial resolution and to separate the total outgoing radiation into reflected Solar and emitted thermal radiation, we propose the joint use of the radiometer with wide field-of-view Shortwave (400–900 nm) and Longwave (8–14 μm) cameras. This paper presents the concept and design of the novel wide field-of-view radiometer, including simulations and analyses of its expected performance. We focus on mechanical design and the measurement characteristics based on optical and thermal analyses. In combination with the cameras, we obtain an estimated accuracy of 0.44 W/m 2 .

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Wide-field motion tuning in nocturnal hawkmoths

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2009.1677 ◽

2009 ◽

Vol 277 (1683) ◽

pp. 853-860 ◽

Cited By ~ 36

Author(s):

Jamie C. Theobald ◽

Eric J. Warrant ◽

David C. O'Carroll

Keyword(s):

Manduca Sexta ◽

Light Sensitivity ◽

Wide Field ◽

Visually Guided ◽

Temporal Acuity ◽

Low Light ◽

Light Levels ◽

Trade Offs ◽

Spatial Frequencies ◽

Deilephila Elpenor

Nocturnal hawkmoths are known for impressive visually guided behaviours in dim light, such as hovering while feeding from nectar-bearing flowers. This requires tight visual feedback to estimate and counter relative motion. Discrimination of low velocities, as required for stable hovering flight, is fundamentally limited by spatial resolution, yet in the evolution of eyes for nocturnal vision, maintenance of high spatial acuity compromises absolute sensitivity. To investigate these trade-offs, we compared responses of wide-field motion-sensitive neurons in three species of hawkmoth: Manduca sexta (a crepuscular hoverer), Deilephila elpenor (a fully nocturnal hoverer) and Acherontia atropos (a fully nocturnal hawkmoth that does not hover as it feeds uniquely from honey in bees' nests). We show that despite smaller eyes, the motion pathway of D. elpenor is tuned to higher spatial frequencies and lower temporal frequencies than A. atropos , consistent with D. elpenor 's need to detect low velocities for hovering. Acherontia atropos , however, presumably evolved low-light sensitivity without sacrificing temporal acuity. Manduca sexta , active at higher light levels, is tuned to the highest spatial frequencies of the three and temporal frequencies comparable with A. atropos . This yields similar tuning to low velocities as in D. elpenor , but with the advantage of shorter neural delays in processing motion.

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Classification of Planetary Nebulae through Deep Transfer Learning

Galaxies ◽

10.3390/galaxies8040088 ◽

2020 ◽

Vol 8 (4) ◽

pp. 88

Author(s):

Dayang N. F. Awang Iskandar ◽

Albert A. Zijlstra ◽

Iain McDonald ◽

Rosni Abdullah ◽

Gary A. Fuller ◽

...

Keyword(s):

Transfer Learning ◽

Planetary Nebulae ◽

Parameter Tuning ◽

Wide Field ◽

Morphological Classification ◽

Trade Offs ◽

Research Platform ◽

Astronomical Images ◽

Future Work

This study investigate the effectiveness of using Deep Learning (DL) for the classification of planetary nebulae (PNe). It focusses on distinguishing PNe from other types of objects, as well as their morphological classification. We adopted the deep transfer learning approach using three ImageNet pre-trained algorithms. This study was conducted using images from the Hong Kong/Australian Astronomical Observatory/Strasbourg Observatory H-alpha Planetary Nebula research platform database (HASH DB) and the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS). We found that the algorithm has high success in distinguishing True PNe from other types of objects even without any parameter tuning. The Matthews correlation coefficient is 0.9. Our analysis shows that DenseNet201 is the most effective DL algorithm. For the morphological classification, we found for three classes, Bipolar, Elliptical and Round, half of objects are correctly classified. Further improvement may require more data and/or training. We discuss the trade-offs and potential avenues for future work and conclude that deep transfer learning can be utilized to classify wide-field astronomical images.

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Method to Determine Initial Estimates for the Air Handling System Layout of IC Engines Based on Turbomachinery Design Rules

Volume 8: Microturbines, Turbochargers and Small Turbomachines; Steam Turbines ◽

10.1115/gt2016-56996 ◽

2016 ◽

Author(s):

Rodrigo Rodriguez Erdmenger ◽

Cathal Clancy ◽

Aneesh Vadvadgi ◽

Thomas Lavertu

Keyword(s):

Internal Combustion Engines ◽

Current Paper ◽

Simple Method ◽

Design Rules ◽

Handling System ◽

Turbine Performance ◽

Trade Offs ◽

Expected Performance ◽

Turbomachinery Design ◽

Selection Of

During the initial layout of a new air-handling system for internal combustion engines, the systems engineers need to make significant assumptions based on experience regarding the compressor performance, operating range, the turbine performance and volute and ducting losses. Typically, the initial sizing occurs before the selection of the turbocharger layout and before actual turbocharger maps are available. On the other hand the system information is key to be able to customize and match the compressor and the turbine performance to meet the specific engine requirements which may be significantly different depending on the engine type application. The current paper proposes a simple method to leverage basic turbomachinery design rules, correlations and databases to provide guidance to the system engineers on the expected performance of the air handling components. Additionally the current paper discusses the trade-offs that could be made on turbocharger performance by the adequate selection of the turbine and compressor couple that addresses the specific engine application needs.

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Multi-fluorescence high-resolution episcopic microscopy (MF-HREM) for three dimensional imaging of adult murine organs

10.1101/2020.04.03.023978 ◽

2020 ◽

Cited By ~ 1

Author(s):

Claire Walsh ◽

Natalie Holroyd ◽

Eoin Finnerty ◽

Sean G. Ryan ◽

Paul W. Sweeney ◽

...

Keyword(s):

High Resolution ◽

3D Imaging ◽

Three Dimensional ◽

Image Resolution ◽

Biological Research ◽

Wide Field ◽

Vascular Networks ◽

Optical Sectioning ◽

Trade Offs ◽

Xenograft Models

AbstractThree-dimensional microscopy of large biological samples (>0.5 cm3) is transforming biological research. Many existing techniques require trade-offs between image resolution and sample size, require clearing or use optical sectioning. These factors complicate the implementation of large volume 3D imaging. Here we present Multi-fluorescent High Resolution Episcopic Microscopy (MF-HREM) which allows 3D imaging of large samples without the need for clearing or optical sectioning.MF-HREM uses serial-sectioning and block-facing wide-field fluorescence, without the need for tissue clearing or optical sectioning. We detail developments in sample processing including stain penetration, resin embedding and imaging. In addition, we describe image post-processing methods needed to segment and further quantify these data. Finally, we demonstrate the wide applicability of MF-HREM by: 1) quantifying adult mouse glomeruli. 2) identifying injected cells and vascular networks in tumour xenograft models; 3) quantifying vascular networks and white matter track orientation in mouse brain.

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STM studies of crystal growth

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100086179 ◽

1991 ◽

Vol 49 ◽

pp. 374-375

Author(s):

M. G. Lagally

Keyword(s):

Crystal Growth ◽

Molecular Beam ◽

Chemical Vapor ◽

Sputter Deposition ◽

Field Of View ◽

Scanning Tunneling ◽

Wide Field ◽

Tunneling Microscopy ◽

Wide Field Of View ◽

The One

It has been recognized since the earliest days of crystal growth that kinetic processes of all Kinds control the nature of the growth. As the technology of crystal growth has become ever more refined, with the advent of such atomistic processes as molecular beam epitaxy, chemical vapor deposition, sputter deposition, and plasma enhanced techniques for the creation of “crystals” as little as one or a few atomic layers thick, multilayer structures, and novel materials combinations, the need to understand the mechanisms controlling the growth process is becoming more critical. Unfortunately, available techniques have not lent themselves well to obtaining a truly microscopic picture of such processes. Because of its atomic resolution on the one hand, and the achievable wide field of view on the other (of the order of micrometers) scanning tunneling microscopy (STM) gives us this opportunity. In this talk, we briefly review the types of growth kinetics measurements that can be made using STM. The use of STM for studies of kinetics is one of the more recent applications of what is itself still a very young field.

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Novel players fine-tune plant trade-offs

Essays in Biochemistry ◽

10.1042/bse0580083 ◽

2015 ◽

Vol 58 ◽

pp. 83-100 ◽

Cited By ~ 25

Author(s):

Selena Gimenez-Ibanez ◽

Marta Boter ◽

Roberto Solano

Keyword(s):

Ubiquitin Ligase ◽

Feedback Loop ◽

Molecular Level ◽

26S Proteasome ◽

Signalling Molecules ◽

Transcriptional Reprogramming ◽

Trade Offs ◽

Jaz Proteins ◽

Regulatory Feedback Loop ◽

Fine Tune

Jasmonates (JAs) are essential signalling molecules that co-ordinate the plant response to biotic and abiotic challenges, as well as co-ordinating several developmental processes. Huge progress has been made over the last decade in understanding the components and mechanisms that govern JA perception and signalling. The bioactive form of the hormone, (+)-7-iso-jasmonyl-l-isoleucine (JA-Ile), is perceived by the COI1–JAZ co-receptor complex. JASMONATE ZIM DOMAIN (JAZ) proteins also act as direct repressors of transcriptional activators such as MYC2. In the emerging picture of JA-Ile perception and signalling, COI1 operates as an E3 ubiquitin ligase that upon binding of JA-Ile targets JAZ repressors for degradation by the 26S proteasome, thereby derepressing transcription factors such as MYC2, which in turn activate JA-Ile-dependent transcriptional reprogramming. It is noteworthy that MYCs and different spliced variants of the JAZ proteins are involved in a negative regulatory feedback loop, which suggests a model that rapidly turns the transcriptional JA-Ile responses on and off and thereby avoids a detrimental overactivation of the pathway. This chapter highlights the most recent advances in our understanding of JA-Ile signalling, focusing on the latest repertoire of new targets of JAZ proteins to control different sets of JA-Ile-mediated responses, novel mechanisms of negative regulation of JA-Ile signalling, and hormonal cross-talk at the molecular level that ultimately determines plant adaptability and survival.

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The miR-21 potential of serving as a biomarker for liver diseases in clinical practice

Biochemical Society Transactions ◽

10.1042/bst20200653 ◽

2020 ◽

Vol 48 (5) ◽

pp. 2295-2305

Author(s):

Jiawei Zhang ◽

Dandan Li ◽

Rui Zhang ◽

Peng Gao ◽

Rongxue Peng ◽

...

Keyword(s):

Clinical Practice ◽

Liver Diseases ◽

Hepatic Disease ◽

Noninvasive Detection ◽

Diagnosis And Prognosis ◽

Expected Performance ◽

Potential Biomarker ◽

Disease Condition ◽

Complex Regulatory Network

The role of miR-21 in the pathogenesis of various liver diseases, together with the possibility of detecting microRNA in the circulation, makes miR-21 a potential biomarker for noninvasive detection. In this review, we summarize the potential utility of extracellular miR-21 in the clinical management of hepatic disease patients and compared it with the current clinical practice. MiR-21 shows screening and prognostic value for liver cancer. In liver cirrhosis, miR-21 may serve as a biomarker for the differentiating diagnosis and prognosis. MiR-21 is also a potential biomarker for the severity of hepatitis. We elucidate the disease condition under which miR-21 testing can reach the expected performance. Though miR-21 is a key regulator of liver diseases, microRNAs coordinate with each other in the complex regulatory network. As a result, the performance of miR-21 is better when combined with other microRNAs or classical biomarkers under certain clinical circumstances.

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