scholarly journals Thermospheric densities derived from spacecraft orbits: Accurate processing of two-line element sets

Author(s):  
J. M. Picone
Author(s):  
Flavio Mercati

This chapter explains in detail the current Hamiltonian formulation of SD, and the concept of Linking Theory of which (GR) and SD are two complementary gauge-fixings. The physical degrees of freedom of SD are identified, the simple way in which it solves the problem of time and the problem of observables in quantum gravity are explained, and the solution to the problem of constructing a spacetime slab from a solution of SD (and the related definition of physical rods and clocks) is described. Furthermore, the canonical way of coupling matter to SD is introduced, together with the operational definition of four-dimensional line element as an effective background for matter fields. The chapter concludes with two ‘structural’ results obtained in the attempt of finding a construction principle for SD: the concept of ‘symmetry doubling’, related to the BRST formulation of the theory, and the idea of ‘conformogeometrodynamics regained’, that is, to derive the theory as the unique one in the extended phase space of GR that realizes the symmetry doubling idea.


IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 62610-62618 ◽  
Author(s):  
Zhang Youzheng ◽  
Mui Yanping

2019 ◽  
Vol 63 (3) ◽  
pp. 1289-1317
Author(s):  
Aleksander A. Lidtke ◽  
David J. Gondelach ◽  
Roberto Armellin

2020 ◽  
Vol 3 (4) ◽  
pp. 1233
Author(s):  
Albert Albert ◽  
Daniel Christianto ◽  
Hadi Pranata

ABSTRACTAlthough elastic analysis gives a good indication of the elastic capacity and behavior of a building, but the elastic method can’t predict when the first yield will occur, and the failure mechanism and account for redistribution of member forces when the plastic hinges progressively formed. The use of inelastic procedure for evaluation is an attempt made by engineer in the past days to better understand how the structure will behave when subjected to strong earthquake, assuming the elastic capacity of the structure will be exceeded. In this research the pushover analysis was done using the modelling criteria of FEMA 356. The modeling of C-flanged shear was done using line element with the equivalent strength and stiffness properties. Target displacement was calculated using the displacement coefficient method of FEMA 356. Based on the analysis the triangular load pattern resulted in larger target displacement than the uniform load. But the uniform load pattern gives larger seismic response than the triangular load pattern. The uniform load pattern resulted in Life Safety performance level, while the triangular load pattern resulted in Immediate Occupancy, based on the two load patterns used the structure resulted in Life Safety performance level.ABSTRAKWalaupun analisis elastik memberikan indikasi yang baik mengenai kapasitas dan perilaku elastik dari suatu gedung, tetapi metode elastik tidak dapat memperkirakan kapan pelelehan pertama terjadi, serta mekanisme kegagalan apa yang mungkin terjadi pada bangunan tersebut, dan memperkirakan redistribusi dari gaya- gaya dalam ketika pembentukan sendi plastis secara progresif terjadi. Fungsi dari analisis inelastik, sebagai prosedur untuk mengevaluasi bangunan, yang merupakan usaha dari insinyur-insinyur terdahulu memahami bagaimana struktur akan berperilaku apabila dikenai gempa kuat, dimana diasumsikan bahwa kapasitas elastik gedung telah terlampaui. Dalam penelitian ini dilakukan pushover analysis menggunakan kriteria pemodelan berdasarkan FEMA 356. Pemodelan dari dinding geser bersayap C dilakukan menggunakan line element dengan kekuatan dan kekakuan yang ekivalen. Target perpindahan dianalisis menggunakan metode coefficient of displacement dari FEMA 356. Berdasarkan analisis yang dilakukan didapat bahwa pembebanan segitiga lebih besar dibandingkan pembebanan merata. Namun, respons seismik yang didapat akibat beban merata, lebih besar dibandingkan beban segitiga. Pembebanan merata menghasilkan tingkatan kinerja Life Safety, sedangkan pembebanan segitiga menghasilkan tingkatan kinerja Immadiate Occupancy, berdasarkan kedua pembebanan tersebut didapat kinerja dari struktur tersebut adalah Life Safety.


2014 ◽  
Vol 11 (08) ◽  
pp. 1450067 ◽  
Author(s):  
Diego Julio Cirilo-Lombardo ◽  
Thiago Prudêncio

We show that the metric (line element) is the first geometrical object to be associated to a discrete (quantum) structure of the spacetime without necessity of black hole-entropy-area arguments, in sharp contrast with other attempts in the literature. To this end, an emergent metric solution obtained previously in [ Phys. Lett. B661 (2008) 186–191] from a particular non-degenerate Riemannian superspace is introduced. This emergent metric is described by a physical coherent state belonging to the metaplectic group Mp (n) with a Poissonian distribution at lower n (number basis) restoring the classical thermal continuum behavior at large n(n → ∞), or leading to non-classical radiation states, as is conjectured in a quite general basis by means of the Bekenstein–Mukhanov effect. Group-dependent conditions that control the behavior of the macroscopic regime spectrum (thermal or not), as the relationship with the problem of area/entropy of the black hole are presented and discussed.


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