scholarly journals DESIGNING REMOTE PLACES IN THE POST-WAR AND PANDEMIC SCENARIOS. SMART SURVEYING OF THE GAHAYR CAMPUS IN MOGADISHU

2021 ◽  
Vol XLVI-M-1-2021 ◽  
pp. 1-8
Author(s):  
C. Achille ◽  
F. Fassi ◽  
A. Mandelli ◽  
C. Del Pero ◽  
F. Leonforte ◽  
...  
Keyword(s):  
Real Time ◽  
Staff Training ◽  
Development Cooperation ◽  
High Quality ◽  
Careful Planning ◽  
Local Conditions ◽  
Survey Team ◽  
National University ◽  
Post War ◽  
Preliminary Phase

Abstract. The study presents a part of the operational framework of the “Project for Infrastructure and Strategic Strengthening of the Somali National University”, funded by the Italian Agency for Development Cooperation. The project, coordinated by Politecnico di Milano, aims to reconstruct the Gahayr campus of the Somali National University of Mogadishu, which is today almost destroyed due to the civil war. The preliminary phase for reconstruction is a detailed survey of the buildings and the area over which the Campus will be re-built. In a normal situation, the team in charge of the survey would have gone on-site in Mogadishu; nevertheless, the risky local conditions and the Covid-19 pandemic made it impossible to have foreign personnel on-site. Consequently, the choice was to train a local team remotely, giving them the theoretical and practical instruments to face a complete 3D survey of the area and the buildings. Harsh times cannot stop works and activities that usually need the presence of the survey team on the field. Careful planning of the activities, the online staff training and the continuous sharing of the information permitted to get high quality 3D metric results quickly and to have at disposal all dimensional and qualitative valuable information for the project, usable in real-time by the designers and architects without going directly on the site.

Ambivalent Relationships: London's Youth Culture and the Making of the Multi-Racial Society in the 1960s

2018 ◽  
Vol 11 (1) ◽  
pp. 4-26 ◽  
Author(s):  
Felix Fuhg
Keyword(s):  
Working Class ◽  
Social Life ◽  
Youth Culture ◽  
Global Culture ◽  
Local Conditions ◽  
White Working Class ◽  
Ambivalent Relationship ◽  
Post War ◽  
The 1960S ◽  
Class Youth

The emergence and formation of British working-class youth cultures in the 1960s were characterized by an ambivalent relationship between British identity, global culture and the formation of a multicultural society in the post-war decades. While national and local newspapers mostly reported on racial tensions and racially-motivated violence, culminating in the Notting Hill riots of 1958, the relationship between London's white working-class youth and teenagers with migration backgrounds was also shaped by a reciprocal, direct and indirect, personal and cultural exchange based on social interaction and local conditions. Starting from the Notting Hill Riots 1958, the article reconstructs places and cultural spheres of interaction between white working-class youth and teenagers from Caribbean communities in London in the 1960s. Following debates and discussions on race relations and the participation of black youth in the social life of London in the 1960s, the article shows that British working-class youth culture was affected in various ways by the processes of migration. By dealing with the multicultural dimension of the post-war metropolis, white working-class teenagers negotiated socio-economic as well as political changes, contributing in the process to an emergent, new image of post-imperial Britain.

Sky Segmentation for Enhanced Depth Reconstruction and Bokeh Rendering with Efficient Architectures

2020 ◽  
Vol 2020 (14) ◽  
pp. 378-1-378-7
Author(s):  
Tyler Nuanes ◽  
Matt Elsey ◽  
Radek Grzeszczuk ◽  
John Paul Shen
Keyword(s):  
Real Time ◽  
Mobile Device ◽  
Computational Cost ◽  
False Positives ◽  
Compact Model ◽  
High Quality ◽  
False Negatives ◽  
Trade Off ◽  
Depth Reconstruction ◽  
Binary Classifiers

We present a high-quality sky segmentation model for depth refinement and investigate residual architecture performance to inform optimally shrinking the network. We describe a model that runs in near real-time on mobile device, present a new, highquality dataset, and detail a unique weighing to trade off false positives and false negatives in binary classifiers. We show how the optimizations improve bokeh rendering by correcting stereo depth misprediction in sky regions. We detail techniques used to preserve edges, reject false positives, and ensure generalization to the diversity of sky scenes. Finally, we present a compact model and compare performance of four popular residual architectures (ShuffleNet, MobileNetV2, Resnet-101, and Resnet-34-like) at constant computational cost.

scholarly journals Gauge invariant canonical symplectic algorithms for real-time lattice strong-field quantum electrodynamics

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Qiang Chen ◽  
Jianyuan Xiao ◽  
Peifeng Fan
Keyword(s):  
Field Theory ◽  
Real Time ◽  
Quantum Electrodynamics ◽  
Symplectic Form ◽  
Strong Field ◽  
Relativistic Quantum ◽  
High Order ◽  
High Quality ◽  
Geometric Structures ◽  
Gauge Invariant

Abstract A class of high-order canonical symplectic structure-preserving geometric algorithms are developed for high-quality simulations of the quantized Dirac-Maxwell theory based strong-field quantum electrodynamics (SFQED) and relativistic quantum plasmas (RQP) phenomena. With minimal coupling, the Lagrangian density of an interacting bispinor-gauge fields theory is constructed in a conjugate real fields form. The canonical symplectic form and canonical equations of this field theory are obtained by the general Hamilton’s principle on cotangent bundle. Based on discrete exterior calculus, the gauge field components are discreted to form a cochain complex, and the bispinor components are naturally discreted on a staggered dual lattice as combinations of differential forms. With pull-back and push-forward gauge covariant derivatives, the discrete action is gauge invariant. A well-defined discrete canonical Poisson bracket generates a semi-discrete lattice canonical field theory (LCFT), which admits the canonical symplectic form, unitary property, gauge symmetry and discrete Poincaré subgroup, which are good approximations of the original continuous geometric structures. The Hamiltonian splitting method, Cayley transformation and symmetric composition technique are introduced to construct a class of high-order numerical schemes for the semi-discrete LCFT. These schemes involve two degenerate fermion flavors and are locally unconditional stable, which also preserve the geometric structures. Admitting Nielsen-Ninomiya theorem, the continuous chiral symmetry is partially broken on the lattice. As an extension, a pair of discrete chiral operators are introduced to reconstruct the lattice chirality. Equipped with statistically quantization-equivalent ensemble models of the Dirac vacuum and non-trivial plasma backgrounds, the schemes are expected to have excellent performance in secular simulations of relativistic quantum effects, where the numerical errors of conserved quantities are well bounded by very small values without coherent accumulation. The algorithms are verified in detail by numerical energy spectra. Real-time LCFT simulations are successfully implemented for the nonlinear Schwinger mechanism induced e-e+ pairs creation and vacuum Kerr effect, where the nonlinear and non-perturbative features captured by the solutions provide a complete strong-field physical picture in a very wide range, which open a new door toward high-quality simulations in SFQED and RQP fields.

Low-Cost Measurement of Hydraulic Fracture Dimensions Using Pressure Data in Treatment and Observation Wells – A Workflow for Every Well

2021 ◽  
Author(s):  
A. Kirby Nicholson ◽  
Robert C. Bachman ◽  
R. Yvonne Scherz ◽  
Robert V. Hawkes
Keyword(s):  
Hydraulic Fracturing ◽  
Real Time ◽  
Hydraulic Fracture ◽  
Full Scale ◽  
Pressure Data ◽  
Observation Well ◽  
High Quality ◽  
Fracture Length ◽  
Geometry Model ◽  
Observation Wells

Abstract Pressure and stage volume are the least expensive and most readily available data for diagnostic analysis of hydraulic fracturing operations. Case history data from the Midland Basin is used to demonstrate how high-quality, time-synchronized pressure measurements at a treatment and an offsetting shut-in producing well can provide the necessary input to calculate fracture geometries at both wells and estimate perforation cluster efficiency at the treatment well. No special wellbore monitoring equipment is required. In summary, the methods outlined in this paper quantifies fracture geometries as compared to the more general observations of Daneshy (2020) and Haustveit et al. (2020). Pressures collected in Diagnostic Fracture Injection Tests (DFITs), select toe-stage full-scale fracture treatments, and offset observation wells are used to demonstrate a simple workflow. The pressure data combined with Volume to First Response (Vfr) at the observation well is used to create a geometry model of fracture length, width, and height estimates at the treatment well as illustrated in Figure 1. The producing fracture length of the observation well is also determined. Pressure Transient Analysis (PTA) techniques, a Perkins-Kern-Nordgren (PKN) fracture propagation model and offset well Fracture Driven Interaction (FDI) pressures are used to quantify hydraulic fracture dimensions. The PTA-derived Farfield Fracture Extension Pressure, FFEP, concept was introduced in Nicholson et al. (2019) and is summarized in Appendix B of this paper. FFEP replaces Instantaneous Shut-In Pressure, ISIP, for use in net pressure calculations. FFEP is determined and utilized in both DFITs and full-scale fracture inter-stage fall-off data. The use of the Primary Pressure Derivative (PPD) to accurately identify FFEP simplifies and speeds up the analysis, allowing for real time treatment decisions. This new technique is called Rapid-PTA. Additionally, the plotted shape and gradient of the observation-well pressure response can identify whether FDI's are hydraulic or poroelastic before a fracture stage is completed and may be used to change stage volume on the fly. Figure 1Fracture Geometry Model with FDI Pressure Matching Case studies are presented showing the full workflow required to generate the fracture geometry model. The component inputs for the model are presented including a toe-stage DFIT, inter-stage pressure fall-off, and the FDI pressure build-up. We discuss how to optimize these hydraulic fractures in hindsight (look-back) and what might have been done in real time during the completion operations given this workflow and field-ready advanced data-handling capability. Hydraulic fracturing operations can be optimized in real time using new Rapid-PTA techniques for high quality pressure data collected on treating and observation wells. This process opens the door for more advanced geometry modeling and for rapid design changes to save costs and improve well productivity and ultimate recovery.

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