2,354 research outputs found

    Hypervisor Integrity Measurement Assistant

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    An attacker who has gained access to a computer may want to upload or modify configuration files, etc., and run arbitrary programs of his choice. We can severely restrict the power of the attacker by having a white-list of approved file checksums and preventing the kernel from loading loading any file with a bad checksum. The check may be placed in the kernel, but that requires a kernel that is prepared for it. The check may also be placed in a hypervisor which intercepts and prevents the kernel from loading a bad file. We describe the implementation of and give performance results for two systems. In one the checksumming, or integrity measurement, and decision is performed by the hypervisor instead of the OS. In the other only the final integrity decision is done in the hypervisor. By moving the integrity check out from the VM kernel it becomes harder for the intruder to bypass the check. We conclude that it is technically possible to put file integrity control into the hypervisor, both for kernels without and with pre-compiled support for integrity measurement

    Heavy Tetraquarks in the Diquark-Antidiquark Picture

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    The homogeneous Lippmann-Schwinger integral equation is solved in momentum space to calculate the masses of heavy tetraquarks with hidden charm and bottom. The tetraquark bound states are studied in the diquark-antidiquark picture as a two-body problem. A regularized form of the diquark-antidiquark potential is used to overcome the singularity of the confining potential at large distances or small momenta. Our numerical results indicate that the relativistic effect leads to a small reduction in the mass of heavy tetraquarks, which is less than 2%2\,\% for charm and less than 0.2%0.2\,\% for bottom tetraquarks. The calculated masses of heavy tetraquarks for 1s1s, 1p1p, 2s2s, 1d1d and 2p2p states are in good agreement with other theoretical calculations and experimental data. Our numerical analysis predict the masses of heavy tetraquarks for 3s3s, 2d2d and 3p3p states for the first time, and we are not aware of any other theoretical results or experimental data for these states

    A Hybrid Three Layer Architecture for Fire Agent Management in Rescue Simulation Environment

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    This paper presents a new architecture called FAIS for imple- menting intelligent agents cooperating in a special Multi Agent environ- ment, namely the RoboCup Rescue Simulation System. This is a layered architecture which is customized for solving fire extinguishing problem. Structural decision making algorithms are combined with heuristic ones in this model, so it's a hybrid architecture

    Universal Personal Transfer

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