The Experts below are selected from a list of 171 Experts worldwide ranked by ideXlab platform
R. Massabò - One of the best experts on this subject based on the ideXlab platform.
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Thermo-elastic solutions for multiLayered wide plates and beams with interfacial imperfections through the transfer matrix method
Meccanica, 2018Co-Authors: H. Darban, R. MassabòAbstract:A matrix technique is formulated to efficiently solve stationary two-dimensional thermo-elasticity problems in simply supported multiLayered beams and plates with an arbitrary number of Layers which may be in imperfect mechanical and thermal contact. The method uses local transfer matrices and continuity conditions at the Layer interfaces to establish explicit relationships between the unknown integration constants in the solution of a Generic Layer and those of the first Layer. Explicit expressions are then derived for temperature, displacements and stresses through the imposition of the boundary conditions at the top and bottom surfaces of the plate. The dimensionless expressions allow to easily generate exact solutions, also for plates with many Layers and interfacial thermal and mechanical imperfections. The solutions can be used for parametric analyses, to investigate the influence of the inhomogeneous material structure and interfacial imperfections on local fields or to verify the accuracy of approximate theories and numerical models.
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2D thermo-elastic solutions for laminates and sandwiches with interLayer delaminations and imperfect thermal contact
Dynamic Response and Failure of Composite Materials and Structures, 2017Co-Authors: H. Darban, R. MassabòAbstract:A matrix technique is used along with the linear theory of 2D thermo-elasticity to efficiently solve the steady-state thermo-mechanical problem in simply supported multiLayered wide plates and beams with an arbitrary number of imperfectly bonded Layers and thermally imperfect interfaces. The method uses local transfer matrices and continuity conditions at the interfaces to establish explicit matrix relationships between the unknown integration constants in the solution of a Generic Layer and those of the first Layer. The thermo-elasticity problem of a plate with many Layers is then reduced to that of a single-Layer plate whose solution can be obtained through the imposition of the boundary conditions. Explicit formulas are derived which simplify the solution procedure and provide a framework to easily generate any desirable benchmark solutions for the verification of approximate theories. Exemplary solutions are presented for plates with three and five Layers.
H. Darban - One of the best experts on this subject based on the ideXlab platform.
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Thermo-elastic solutions for multiLayered wide plates and beams with interfacial imperfections through the transfer matrix method
Meccanica, 2018Co-Authors: H. Darban, R. MassabòAbstract:A matrix technique is formulated to efficiently solve stationary two-dimensional thermo-elasticity problems in simply supported multiLayered beams and plates with an arbitrary number of Layers which may be in imperfect mechanical and thermal contact. The method uses local transfer matrices and continuity conditions at the Layer interfaces to establish explicit relationships between the unknown integration constants in the solution of a Generic Layer and those of the first Layer. Explicit expressions are then derived for temperature, displacements and stresses through the imposition of the boundary conditions at the top and bottom surfaces of the plate. The dimensionless expressions allow to easily generate exact solutions, also for plates with many Layers and interfacial thermal and mechanical imperfections. The solutions can be used for parametric analyses, to investigate the influence of the inhomogeneous material structure and interfacial imperfections on local fields or to verify the accuracy of approximate theories and numerical models.
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2D thermo-elastic solutions for laminates and sandwiches with interLayer delaminations and imperfect thermal contact
Dynamic Response and Failure of Composite Materials and Structures, 2017Co-Authors: H. Darban, R. MassabòAbstract:A matrix technique is used along with the linear theory of 2D thermo-elasticity to efficiently solve the steady-state thermo-mechanical problem in simply supported multiLayered wide plates and beams with an arbitrary number of imperfectly bonded Layers and thermally imperfect interfaces. The method uses local transfer matrices and continuity conditions at the interfaces to establish explicit matrix relationships between the unknown integration constants in the solution of a Generic Layer and those of the first Layer. The thermo-elasticity problem of a plate with many Layers is then reduced to that of a single-Layer plate whose solution can be obtained through the imposition of the boundary conditions. Explicit formulas are derived which simplify the solution procedure and provide a framework to easily generate any desirable benchmark solutions for the verification of approximate theories. Exemplary solutions are presented for plates with three and five Layers.
G. Martiniello - One of the best experts on this subject based on the ideXlab platform.
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ICC - Wireless LAN-3G Integration: Unified Mechanisms for Secure Authentication based on SIP
2006 IEEE International Conference on Communications, 2006Co-Authors: Luca Veltri, Stefano Salsano, G. MartinielloAbstract:In WLANs, secure access can be provided operating at link Layer, at network Layer (IP) or at application level, and several solutions have been implemented in current public/private access networks; however most of them are proprietary and the interworking between different operators is still an open issue. At the same time, the 3GPP is working in integrating the WLAN access with the rest of 3GPP/UMTS network infrastructure. In this paper we propose a Generic Layer-two-independent open solution for secure authentication in a heterogeneous wireless access scenario based on 3G SIM credentials and on the SIP protocol. The solution follows the 3G specification for the authentication in the IMS, with the only addition of a new parameter in a specific header of the SIP protocol. Therefore the security infrastructure of the 3G networks can be fully reused also in scenarios in which the visited network does not provide 3G services. The proposed solution has been implemented in a testbed in which UMTS, 802.11, and Bluetooth has been used as access technologies.
Freek Wiedijk - One of the best experts on this subject based on the ideXlab platform.
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Proviola: A Tool for Proof Re-animation
arXiv: Logic in Computer Science, 2010Co-Authors: Carst Tankink, Herman Geuvers, James Mckinna, Freek WiedijkAbstract:To improve on existing models of interaction with a proof assistant (PA), in particular for storage and replay of proofs, we in- troduce three related concepts, those of: a proof movie, consisting of frames which record both user input and the corresponding PA response; a camera, which films a user's interactive session with a PA as a movie; and a proviola, which replays a movie frame-by-frame to a third party. In this paper we describe the movie data structure and we discuss a proto- type implementation of the camera and proviola based on the ProofWeb system. ProofWeb uncouples the interaction with a PA via a web- interface (the client) from the actual PA that resides on the server. Our camera films a movie by "listening" to the ProofWeb communication. The first reason for developing movies is to uncouple the reviewing of a formal proof from the PA used to develop it: the movie concept enables users to discuss small code fragments without the need to install the PA or to load a whole library into it. Other advantages include the possibility to develop a separate com- mentary track to discuss or explain the PA interaction. We assert that a combined camera+proviola provides a Generic Layer between a client (user) and a server (PA). Finally we claim that movies are the right type of data to be stored in an encyclopedia of formalized mathematics, based on our experience in filming the Coq standard library.
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AISC/MKM/Calculemus - Proviola: a tool for proof re-animation
Lecture Notes in Computer Science, 2010Co-Authors: Carst Tankink, Herman Geuvers, James Mckinna, Freek WiedijkAbstract:To improve on existing models of interaction with a proof assistant (PA), in particular for storage and replay of proofs, we introduce three related concepts, those of: a proof movie, consisting of frames which record both user input and the corresponding PA response; a camera, which films a user's interactive session with a PA as a movie; and a proviola, which replays a movie frame-by-frame to a third party. In this paper we describe the movie data structure and we discuss a prototype implementation of the camera and proviola based on the ProofWeb system [7]. ProofWeb uncouples the interaction with a PA via a web-interface (the client) from the actual PA that resides on the server. Our camera films a movie by "listening" to the ProofWeb communication. The first reason for developing movies is to uncouple the reviewing of a formal proof from the PA used to develop it: the movie concept enables users to discuss small code fragments without the need to install the PA or to load a whole library into it. Other advantages include the possibility to develop a separate commentary track to discuss or explain the PA interaction. We assert that a combined camera+proviola provides a Generic Layer between a client (user) and a server (PA). Finally we claim that movies are the right type of data to be stored in an encyclopedia of formalized mathematics, based on our experience in filming the Coq standard library.
Luca Veltri - One of the best experts on this subject based on the ideXlab platform.
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ICC - Wireless LAN-3G Integration: Unified Mechanisms for Secure Authentication based on SIP
2006 IEEE International Conference on Communications, 2006Co-Authors: Luca Veltri, Stefano Salsano, G. MartinielloAbstract:In WLANs, secure access can be provided operating at link Layer, at network Layer (IP) or at application level, and several solutions have been implemented in current public/private access networks; however most of them are proprietary and the interworking between different operators is still an open issue. At the same time, the 3GPP is working in integrating the WLAN access with the rest of 3GPP/UMTS network infrastructure. In this paper we propose a Generic Layer-two-independent open solution for secure authentication in a heterogeneous wireless access scenario based on 3G SIM credentials and on the SIP protocol. The solution follows the 3G specification for the authentication in the IMS, with the only addition of a new parameter in a specific header of the SIP protocol. Therefore the security infrastructure of the 3G networks can be fully reused also in scenarios in which the visited network does not provide 3G services. The proposed solution has been implemented in a testbed in which UMTS, 802.11, and Bluetooth has been used as access technologies.