Analysis of Generalized Grover's Quantum Search Algorithms Using Recursion Equations

The recursion equation analysis of Grover's quantum search algorithm presented by Biham et al. [PRA 60, 2742 (1999)] is generalized. It is applied to the large class of Grover's type algorithms in which the Hadamard transform is replaced by any other unitary transformation and the phase inversion is replaced by a rotation by an arbitrary angle. The time evolution of the amplitudes of the marked and unmarked states, for any initial complex amplitude distribution is expressed using first order linear difference equations. These equations are solved exactly. The solution provides the number of iterations T after which the probability of finding a marked state upon measurement is the highest, as well as the value of this probability, P_max. Both T and P_max are found to depend on the averages and variances of the initial amplitude distributions of the marked and unmarked states, but not on higher moments.Comment: 8 pages, no figures. To appear in Phys. Rev.

Building and Testing a Statistical Shape Model of the Human Ear Canal

Abstract. Today the design of custom in-the-ear hearing aids is based on personal experience and skills and not on a systematic description of the variation of the shape of the ear canal. In this paper it is described how a dense surface point distribution model of the human ear canal is built based on a training set of laser scanned ear impressions and a sparse set of anatomical landmarks placed by an expert. The landmarks are used to warp a template mesh onto all shapes in the training set. Using the vertices from the warped meshes, a 3D point distribution model is made. The model is used for testing for gender related differences in size and shape of the ear canal.

THE HIGH FIELD THERMOMAGNETIC COEFFICIENTS OF POTASSIUM

Nous présentons des résultats sur la résistivité Righi-Leduc γyx et la magnétorésistance thermique transverse γxx du potassium polycrystallin à basses températures (1,5≤T≤4,5 K) en champ appliqué jusqu'à 4.5 tesla. On peut comprendre nos valeurs à l'aide de la théorie semi-classique utilisant un champ élevé. Nous pouvons ainsi déterminer la conductibilité thermique du réseau avec précision.We present data on the Righi-Leduc resistivity γxx and the transverse thermal magnetoresistivity γxx of polycrystalline potassium for 1.5 K ≤ T≤ 4.5 K, and for fields up to 4.5 telsa. We find that our data can be understood within the framework of high field semi classical theory and we are able to accurately extract the lattice thermal conductivity

Towards Making Broadcast Encryption Practical

The problem we address is how to communicate securely with a set of users (the target set) over an insecure broadcast channel. In order to solve this problem, several broadcast encryption schemes have been proposed. In these systems, the parameters of major concern are the length of transmission and number of keys held by each user's set top terminal (STT). Due to the need to withstand hardware tampering, the amount of secure memory available in the STTs is quite small, severely limiting the number of keys each user holds. In such cases, known theoretical bounds seem to indicate that non-trivial broadcast encryption schemes are only feasible when the number of users is small. In order to break away from these theoretical bounds, our approach is to allow a controlled number of users outside the target set to occasionally receive the multicast. This relaxation is appropriate for low-cost transmissions such as multicasting electronic coupons. For this purpose, we introduce f-redundant est..

Intellectual property metering

Abstract. We have developed the first hardware and software (intellectual property) metering scheme that enables reliable low overhead proofs for the number of manufactured parts and copied programs. The key idea is to make each design slightly different during postprocessing phase. Therefore, if two identical hardware/software designs or a design that is not reported by the foundry are detected, the design house has proof of misconduct. We start by establishing implementation requirements for hardware metering. We also establish the connection between the requirements for hardware and software metering and synthesis process. Furthermore, we present mathematical analysis of statistical accuracy of the proposed hardware and software metering schemes. The effectiveness of the metering scheme is demonstrated on a numbe