A Novel Basis for Membrane Adaptive Optics: The Clamped Zernike Radial Polynomials

2007 ◽  
Author(s):  
Eric J. Ruggiero ◽  
Daniel J. Inman ◽  
Dan K. Marker
Keyword(s):  
Adaptive Optics ◽  
Mode Shapes ◽  
Deformable Mirrors ◽  
Low Density ◽  
Aberration Correction ◽  
The Novel ◽  
Image Correction ◽  
Wavefront Aberrations ◽  
Optical Aberration ◽  
The Future

The future of adaptive optics relies heavily on the development of membranous optical lenses. Large, deformable mirrors offer clear advantages over their glass counterparts: flexibility, low density, and minimal actuation for optical aberration correction. This paper develops a novel set of polynomials to describe incoming wavefront aberrations that is amiable to a membrane mirror’s mode shapes. The novel basis, named the clamped Zernike radial polynomials, conveniently delineates the image correction into four distinct actuation categories feasible with membrane optics.

Black Books and Brownies

2018 ◽  
Author(s):  
Alison Milbank
Keyword(s):  
Historical Change ◽  
Religious Change ◽  
The Novel ◽  
Black Book ◽  
James Hogg ◽  
The Bible ◽  
The Reformation ◽  
The Future

Scottish fiction about the Reformation is concerned with the mechanics of historical change, which are rendered through a series of enchanted books and people discussed in Chapter 8. In the novel, The Monastery, describing the Dissolution and Reformation, Scott gothicizes the Bible as a magic book and the White Lady as its guardian to dramatize the mysterious nature of religious change, the dependence of the future on a Gothic past, and the need for interpretation. In Old Mortality, Scott’s protagonist escapes the frozen dualities of Covenanter and Claverhouse, revealing historical change itself as problematic in Humean terms and requiring a leap of faith. James Hogg contests this presentation of the Covenanters by re-enchanting them as supposed brownies, as mediators of history and nature, and in his Three Perils of Man reprises Scott’s wizard Michael Scott pitted against Roger Bacon and his ‘black book’ the Bible to present the Reformation as an eternal reality.

Dombey and Son

2008 ◽  
Author(s):  
Charles Dickens ◽  
Dennis Walder
Keyword(s):  
Family Relationships ◽  
The Sun ◽  
The Novel ◽  
The Earth ◽  
The Future ◽  
Original Illustrations ◽  
The One

Dombey and Son ... Those three words conveyed the one idea of Mr. Dombey's life. The earth was made for Dombey and Son to trade in, and the sun and moon were made to give them light.' The hopes of Mr Dombey for the future of his shipping firm are centred on his delicate son Paul, and Florence, his devoted daughter, is unloved and neglected. When the firm faces ruin, and Dombey's second marriage ends in disaster, only Florence has the strength and humanity to save her father from desolate solitude. This new edition contains Dickens's prefaces, his working plans, and all the original illustrations by ‘Phiz’. The text is that of the definitive Clarendon edition. It has been supplemented by a wide-ranging Introduction, highlighting Dickens's engagement with his times, and the touching exploration of family relationships which give the novel added depth and relevance.

La Bête humaine

2009 ◽  
Author(s):  
Émile Zola
Keyword(s):  
Human Nature ◽  
Technological Progress ◽  
Second Empire ◽  
The Novel ◽  
Literary Context ◽  
The Future

Did possessing and killing amount to the same thing deep within the dark recesses of the human beast? La Bete humaine (1890), is one of Zola’s most violent and explicit works. On one level a tale of murder, passion and possession, it is also a compassionate study of individuals derailed by atavistic forces beyond their control. Zola considered this his ‘most finely worked’ novel, and in it he powerfully evokes life at the end of the Second Empire in France, where society seemed to be hurtling into the future like the new locomotives and railways it was building. While expressing the hope that human nature evolves through education and gradually frees itself of the burden of inherited evil, he is constantly reminding us that under the veneer of technological progress there remains, always, the beast within. This new translation captures Zola's fast-paced yet deliberately dispassionate style, while the introduction and detailed notes place the novel in its social, historical, and literary context.

Large-Stroke MEMS Deformable Mirrors for Adaptive Optics

2006 ◽  
Vol 15 (3) ◽  
pp. 572-583 ◽  
Author(s):  
D.J. Dagel ◽  
W.D. Cowan ◽  
O.B. Spahn ◽  
G.D. Grossetete ◽  
A.J. Grine ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Deformable Mirrors

Recent developments in regional transit for Greater Vancouver

1978 ◽  
Vol 5 (3) ◽  
pp. 334-339
Author(s):  
Brian E. Sullivan
Keyword(s):  
Land Use ◽  
High Rate ◽  
Low Density ◽  
Transit System ◽  
Shopping Centres ◽  
The Future ◽  
Recent Developments ◽  
Trunk Routes ◽  
The City ◽  
Capital Intensive

The transit system serving Greater Vancouver has high ridership and a high rate of growth. Using as a base the well-designed, well-patronized trolleybus grid in the City of Vancouver, an inter-connected suburban bus network has been created, with radial, cross-radial, and local routes meeting on a timed connection basis at suburban shopping centres and other foci. Planners' thoughts for the future include greater emphasis on the micro and macro aspects of land use and relations to transit; the use of capital intensive modes for heavy trunk routes; and the use of various forms of para-transit for low-density and certain feeder applications.

Optimal actuator placement in adaptive optics systems

2021 ◽  
pp. 107754632110324
Author(s):  
Berk Altıner ◽  
Bilal Erol ◽  
Akın Delibaşı
Keyword(s):  
Cost Function ◽  
Adaptive Optics ◽  
Disturbance Attenuation ◽  
Linear Quadratic ◽  
Placement Problem ◽  
Convex Optimization Problem ◽  
Wavefront Aberrations ◽  
The Cost ◽  
Actuator Placement ◽  
Quadratic Cost Function

Adaptive optics systems are powerful tools that are implemented to degrade the effects of wavefront aberrations. In this article, the optimal actuator placement problem is addressed for the improvement of disturbance attenuation capability of adaptive optics systems due to the fact that actuator placement is directly related to the enhancement of system performance. For this purpose, the linear-quadratic cost function is chosen, so that optimized actuator layouts can be specialized according to the type of wavefront aberrations. It is then considered as a convex optimization problem, and the cost function is formulated for the disturbance attenuation case. The success of the presented method is demonstrated by simulation results.

Mobility-as-a-Service: Simulation of Multi-Modal Operations in Low-Density Cities

2021 ◽  
pp. 036119812110398
Author(s):  
Mohamed El-Agroudy ◽  
Hatem Abou-Senna ◽  
Essam Radwan
Keyword(s):  
Performance Measures ◽  
Magic Bullet ◽  
Low Density ◽  
The Novel ◽  
Review Of The Literature ◽  
Modal Interactions ◽  
New Approach ◽  
Novel Interactions ◽  
Alternative Scenarios ◽  
Urban Characteristics

In the case of the low-density city, empirical evidence continuously demonstrates that transit investment is not a magic bullet. Desirable outcomes are not guaranteed and are often dependent on development density and other urban characteristics. Mobility-as-a-service (MaaS) presents a new approach: a digital platform providing access to multi-modal travel alternatives and totally comprehensive integrated trip-making, planning, and payment services. Review of the literature highlights shortcomings in traditional transportation planning by examining aspects of multi-modal planning such as adoption, parterships, operations, integration, capacity implications, and impact analyses. To enhance the practice of multi-modal planning, the following experiment evaluates various performance measures and inter-modal interactions on International Drive in Orlando, Florida, U.S., via D- and I-optimal experimental designs in a simulated MaaS network. Alternative scenarios are developed comparing varied modal shares across five travel modes: personal vehicles, transit, ridesourcing (or ride-hailing), micro-mobility, and walking. The modal effects are analyzed to highlight the strengths and weakness of each mode under a variety of congestion conditions. While transit enjoys the lowest impact per person, ridesourcing demonstrates adverse effects across all measures. Based on the novel interactions of transit and ridesourcing with directional demand, strategies are outlined for optimizing ridesourcing-transit integration to reduce route travel time, queuing, and overall network delay. The performance impacts of curbside facilities are also discussed for improved multi-modal integration at the street level. These findings are applied to propose a framework for effective planning and implementation of mobility services in low-density cities, focused on operations, city-level connectivity, and curbside management.

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