Let
be a Riemannian manifold and let
be a bounded open subset of
. It is well known that significant information about the geometry of
is encoded into the properties of the distance,
, from the ...boundary of
. Here, we show that the generalized gradient flow associated with the distance preserves singularities, that is, if
is a singular point of
then the generalized characteristic starting at
stays singular for all times. As an application, we deduce that the singular set of
has the same homotopy type as
.
Status of the construction of the CMS magnet Herve, A.; Blau, B.; Bredy, P. ...
IEEE transactions on applied superconductivity,
06/2004, Letnik:
14, Številka:
2
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
CMS (compact muon solenoid) is a general-purpose detector designed to run at the highest luminosity at the CERN Large Hadron Collider (LHC). Its distinctive features include a 4 T superconducting ...solenoid with 6 m diameter by 12.5 m long free bore, enclosed inside a 10,000-ton return yoke. The stored magnetic energy is 2.6 GJ. The magnet is being assembled in a surface hall and will be tested at the beginning of 2005 before being transferred to an experimental hall 90 m below ground level. The design and construction of the magnet is a common project of the CMS Collaboration. The task is organized by a CERN based group with strong technical and contractual participation of CEA Saclay, ETH Zurich, Fermilab, INFN Genova, ITEP Moscow, University of Wisconsin and CERN. The return yoke, 21 m long and 14 m in diameter, is equivalent to a thickness of 1.5 m of saturated iron interleaved with four muon stations. Manufacture of the yoke and vacuum tank is completed and the first sub-detectors have been installed. The indirectly-cooled, pure-aluminum-stabilized coil is made up from five modules internally wound with four layers of a 20 kA mechanically-reinforced conductor. The manufacture of the conductor is completed and winding is in progress for a final assembly in 2004. All ancillaries are delivered or under contract. The magnet project is described, with emphasis on the present status of the fabrication.
In this paper, we investigate the existence and regularity of solutions for Bolza optimal control problems in infinite dimension governed by a class of semilinear evolution equations. Our results ...apply to systems exhibiting hereditary properties, as heat propagation in real conductors and isothermal viscoelasticity, described by equations with memory terms which account for the past history of the variables in play.
This paper studies the attainable set at time T>0 for the control system $$\dot y(t)=f(y(t),u(t))\,\qquad u(t)\in U$$ showing that, under suitable assumptions on f, such a set satisfies a uniform ...interior sphere condition. The interior sphere property is then applied to recover a semiconcavity result for the value function of time optimal control problems with a general target, and to deduce C1,1-regularity for boundaries of attainable sets.
Semiconcavity results have generally been obtained for optimal control problems in absence of state constraints. In this paper, we prove the semiconcavity of the value function of an optimal control ...problem with end-point constraints for which all minimizing controls are supposed to be nonsingular.
Status of the CMS magnet (MT17) Herve, A.; Acquistapace, G.; Campi, D. ...
IEEE transactions on applied superconductivity,
03/2002, Letnik:
12, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The CMS experiment (Compact Muon Solenoid) is a general-purpose detector designed to run at the highest luminosity at the CERN Large Hadron Collider (LHC). Its distinctive features include a 4 T ...superconducting solenoid with a free bore of 6 m diameter and 12.5-m length, enclosed inside a 10 000-ton return yoke. The magnet will be assembled and tested in a surface hall at Point 5 of the LHC at the beginning of 2004 before being transferred by heavy lifting means to an experimental hall 90 m below ground level. The design and construction of the magnet is a common project of the CMS Collaboration. The task is organized by a CERN based group with strong technical and contractual participation from CEA Saclay, ETH Zurich, Fermilab, INFN Genova, ITEP Moscow, University of Wisconsin and CERN. The magnet project will be described, with emphasis on the present status of the fabrication.
We introduce a general principle determining in certain cases the regularity of the viscosity solutions of Hamilton-Jacobi equations. This principle says that if one can solve the equation forward in ...time from some initial data and then backward in time resulting in the same initial data, then the solution must be C1. Some cases are given when this holds as well as an example when it does not. Convexity of either the hamiltonian or the initial data plays a crucial role throughout.
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