Implementation attacks pose a serious threat for the security of cryptographic devices and there are a multitude of countermeasures that are used to prevent them. Two countermeasures used in implementations of block c...
详细信息
We present a theoretical study of minimum error probability discrimination, using quantum-optical probe states, of M optical phase shifts situated symmetrically on the unit circle. We assume ideal lossless conditions ...
详细信息
We present a theoretical study of minimum error probability discrimination, using quantum-optical probe states, of M optical phase shifts situated symmetrically on the unit circle. We assume ideal lossless conditions and full freedom for implementing quantum measurements and for probe-state selection, subject only to a constraint on the average energy, i.e., photon number. In particular, the probe state is allowed to have any number of signal and ancillary modes and to be pure or mixed. Our results are based on a simple criterion that partitions the set of pure probe states into equivalence classes with the same error probability performance. Under an energy constraint, we find the explicit form of the state that minimizes the error probability. This state is an unentangled but nonclassical single-mode state. The error performance of the optimal state is compared with several standard states in quantum optics. We also show that discrimination with zero error is possible only beyond a threshold energy of (M−1)/2. For the M=2 case, we show that the optimum performance is readily demonstrable with current technology. While transmission loss and detector inefficiencies lead to a nonzero erasure probability, the error rate conditional on no erasure is shown to remain the same as the optimal lossless error rate.
We develop a theory of quantum M-ary phase shift keying in which quantum states of optical modes are modulated at the transmitter by applying one of M uniformly-spaced phase shifts. We allow full freedom in choosing m...
详细信息
We develop a theory of quantum M-ary phase shift keying in which quantum states of optical modes are modulated at the transmitter by applying one of M uniformly-spaced phase shifts. We allow full freedom in choosing modulation states with any number of signal, i.e., transmitted, and ancilla modes, subject only to an average energy, i.e., photon number, constraint in either the signal modes alone or in the signal and ancilla modes together. For lossless operation and unrestricted POVM measurements at the receiver, we find the explicit form of the modulation state that minimizes the average error probability under an energy constraint of N photons. Multiple signal modes, mixed states, and entanglement with an ancilla are shown to be unnecessary for optimum performance. We show that communication with zero error is possible if and only if N ≥ (M - 1)/2.
This paper addresses the denoising problem associated with diffusion MR imaging. Building on previous approaches to this problem, this paper presents a new method for joint denoising of a sequence of diffusion-weighte...
详细信息
ISBN:
(纸本)9781457718571
This paper addresses the denoising problem associated with diffusion MR imaging. Building on previous approaches to this problem, this paper presents a new method for joint denoising of a sequence of diffusion-weighted (DW) magnitude images. The proposed method uses a maximum a posteriori (MAP) estimation formulation to incorporate a Rician likelihood (for modeling the noisy magnitude data), a low rank model (for the DW image sequences) and a spatial prior (for imposing joint edge constraints). An efficient algorithm to solve the associated optimization problem is also described. The proposed method has been evaluated using both simulated and experimental diffusion tensor imaging (DTI) data, which yields very encouraging results both qualitatively and quantitatively.
A flexible transparent modify dipole antenna printed on PET film is presented in this paper. The proposed antenna was designed to operate at 2.4GHz for ISM applications. The impedance characteristic and the radiation ...
详细信息
A flexible transparent modify dipole antenna printed on PET film is presented in this paper. The proposed antenna was designed to operate at 2.4GHz for ISM applications. The impedance characteristic and the radiation characteristic were simulated and measured. The proposed antenna has good performance. It can be easily mounted on conformal shape, because it is fabricated on PET film having the flexible characteristic.
Medicine intake detection and feature selection algorithm are proposed in this paper. A precise medicine intake detection method is crucial in medicine intake monitoring system;it is an important factor in order to pr...
详细信息
Medicine intake detection and feature selection algorithm are proposed in this paper. A precise medicine intake detection method is crucial in medicine intake monitoring system;it is an important factor in order to prevent the harm in the case of medicine non adherence for elderly patients or any people with chronic diseases and need to take medicine regularly. Wrist movement is the main function of intake gesture detection using a wearable 3-axis accelerometer. Activities of interest for medicine taking monitoring are drinking gesture, picking and taking medicine by hand and palm. This paper applied the eigenvalues and covariance for change detection and features selection. Eigenvalues are considered to solve the improper data truncation issue caused by a fixed window size, because respective time during those activities is very varying. Its results are satisfactory. The gestures were classified by feature characteristics with an accuracy as high as 96.7% in the case of medicine taking by palm.
Vertical mode size transformation from 300nm-thick Si-waveguide to 6~7μm, coupling to standard single-mode fiber was demonstrated using CMOS-compatible Si/SiO2 multilayer on-chip GRIN lens (length~11.5μm). Multilaye...
详细信息
We consider the problem of high-dimensional Gaussian graphical model selection. We identify a set of graphs for which an efficient estimation algorithm exists, and this algorithm is based on thresholding of empirical ...
详细信息
We consider the problem of high-dimensional Gaussian graphical model selection. We identify a set of graphs for which an efficient estimation algorithm exists, and this algorithm is based on thresholding of empirical conditional covariances. Under a set of transparent conditions, we establish structural consistency (or sparsistency) for the proposed algorithm, when the number of samples n = Ω(Jmin-2 log p), where p is the number of variables and Jmin is the minimum (absolute) edge potential of the graphical model. The sufficient conditions for sparsistency are based on the notion of walk-summability of the model and the presence of sparse local vertex separators in the underlying graph. We also derive novel non-asymptotic necessary conditions on the number of samples required for sparsistency.
暂无评论