On backward stochastic differential equation with generator f(y)∣z∣2f(y)|z|^2

In this paper, we consider the backward stochastic differential equation (BSDE) with generator $f(y)|z|^2,$ where the function $f$ is defined on an open interval $D$ and locally integrable. The existence and uniqueness of bounded solutions and $L^p(p\geq1)$ solutions of such BSDEs are obtained. Some comparison theorems and a converse comparison theorem of such BSDEs are established. As an application, we give a probabilistic interpretation of viscosity solution of quadratic PDEs.Comment: 16 pages, the previous version is rewritten, the previous results are developed. Comments are welcom

The obstacle problem for nonlinear degenerate equations with L1L^{1}-data

The aim of this paper is to study the obstacle problem with an elliptic operator having degenerate coercivity. We prove the existence of an entropy solution to the obstacle problem under the assumption of $L^{1}-$summability on the data. Meanwhile, we prove that every entropy solution belongs to some Sobolev space $W^{1,q}(\Omega)$.Comment: 21 pages. arXiv admin note: text overlap with arXiv:1003.2305 by other author

Topo-electronic transitions in Sb(111) nanofilm: the interplay between quantum confinement and surface effect

When the dimension of a solid structure is reduced, there will be two emerging effects, quantum confinement and surface effect, which dominate at nanoscale. Based on first-principles calculations, we demonstrate that due to an intriguing interplay between these two dominating effects, the topological and electronic (topo-electronic) properties of Sb (111) nanofilms undergo a series of transitions as a function of the reducing film thickness: transforming from a topological semimetal to a topological insulator at 7.8 nm (22 bilayer), then to a quantum spin hall (QSH) phase at 2.7 nm (8 bilayer), and finally to a normal (topological trivial) semiconductor at 1.0 nm (3 bilayer). Our theoretical findings for the first time identify the existence of the QSH in the Sb (111) nanofilms within a narrow range of thickness and suggest that the Sb (111) nanofilms provide an ideal test bed for experimental study of topo-electronic phase transitions.Comment: 4 pages, 4 figure

Finite-volume formalism in the 2→HI+HI22 \xrightarrow[]{H_I+H_I} 2 transition: an application to the lattice QCD calculation of double beta decays

We present the formalism for connecting a second-order electroweak $2\xrightarrow[]{H_I+H_I}2$ transition amplitudes in the finite volume (with two hadrons in the initial and final states) to the physical amplitudes in the infinite volume. Our study mainly focus on the case where the low-lying intermediate state consists of two scattering hadrons. As a side product we also reproduce the finite-volume formula for $2\xrightarrow[]{H_I}2$ transition, originally obtained by Brice\~no and Hansen. With the available finite-volume formalism, we further discuss how to treat with the finite-volume problem in the double beta decays $nn\to pp ee\bar{\nu}\bar{\nu}$ and $nn\to pp ee$.Comment: 18 page

Synthetic spin-orbit coupling and topological polaritons in Janeys-Cummings lattices

The interaction between a photon and a qubit in the Janeys-Cummings (JC) model generates a kind of quasiparticle called polariton. While they are widely used in quantum optics, difficulties in engineering controllable coupling of them severely limit their applications to simulate spinful quantum systems. Here we show that, in the superconducting quantum circuit context, polariton states in the single-excitation manifold of a JC lattice can be used to simulate a spin-1/2 system, based on which tunable synthetic spin-orbit coupling and novel topological polaritons can be generated and explored. The lattice is formed by a sequence of coupled transmission line resonators, each of which is connected to a transmon qubit. Synthetic spin-orbit coupling and effective Zeeman field of the polariton can both be tuned by modulating the coupling strength between neighbouring resonators, allowing for the realization of a large variety of polaritonic topological semimetal bands. Methods for detecting the polaritonic topological edge states and topological invariants are also proposed. Therefore, our work suggests that the JC lattice is a versatile platform for exploring spinful topological states of matter, which may inspire developments of topologically protected quantum optical and information processing devices.Comment: V2: Extended rewritten version; V3: Accepted version; V4 published version with correction

Fuzzy SLIC: Fuzzy Simple Linear Iterative Clustering

Most superpixel methods are sensitive to noise and cannot control the superpixel number precisely. To solve these problems, in this paper, we propose a robust superpixel method called fuzzy simple linear iterative clustering (Fuzzy SLIC), which adopts a local spatial fuzzy C-means clustering and dynamic fuzzy superpixels. We develop a fast and precise superpixel number control algorithm called onion peeling (OP) algorithm. Fuzzy SLIC is insensitive to most types of noise, including Gaussian, salt and pepper, and multiplicative noise. The OP algorithm can control the superpixel number accurately without reducing much computational efficiency. In the validation experiments, we tested the Fuzzy SLIC and OP algorithm and compared them with state-of-the-art methods on the BSD500 and Pascal VOC2007 benchmarks. The experiment results show that our methods outperform state-of-the-art techniques in both noise-free and noisy environments.Comment: 12 pages, 14 figures. This paper has been accepted as a Transactions Paper for publication by IEEE Transactions on Circuits and Systems for Video Technolog

The quantum nature of the superconducting hydrogen sulfide at finite temperatures

H$_3$S is believed to the most possible high-temperature superconducting ($T_{\text{c}}$) phase of hydrogen sulfide at $\sim$200 GPa. It's isotope substitution of hydrogen (H) by deuterium (D), however, shows an anomalous $T_{\text{c}}$ decrease of $\sim$100 K at 140 to 160 GPa, much larger than the Bardeen-Cooper-Schrieffer theory prediction. Using ab initio path-integral molecular dynamics (PIMD), we show that the nuclear quantum effects (NQEs) influence the structures of H$_3$S and D$_3$S differently at finite temperatures and the interval when H$_3$S possesses the symmetric high $T_{\text{c}}$ structure while D$_3$S does not is in agreement with, though their absolute values are lower than experiments. This is consistent with an earlier theoretical study using the stochastic self-consistent harmonic approximation method in descriptions of the nuclei at 0 K.The remaining discrepancy can be substantially improved when the electronic structures are calculated using a hybrid function. Our study presents a simple picture to interpret the isotope dependent of $T_{\text{c}}$ and emphasizes the quantum nature in the high-pressure hydrogen sulfide system.Comment: 7 page

Single-step implementation of a multiple-target-qubit controlled phase gate without need of classical pulses

We propose a simple method for realizing a multiqubit phase gate of one qubit simultaneously controlling $n$ target qubits, by using three-level quantum systems (i.e., qutrits) coupled to a cavity or resonator. The gate can be implemented using one operational step and without need of classical pulses, and no photon is populated during the operation. Thus, the gate operation is greatly simplified and decoherence from the cavity decay is much reduced, when compared with the previous proposals. In addition, the operation time is independent of the number of qubits and no adjustment of the qutrit level spacings or the cavity frequency is needed during the operation.Comment: 4 pages, 3 figure

Data hiding in Fingerprint Minutiae Template for Privacy Protection

In this paper, we propose a novel scheme for data hiding in the fingerprint minutiae template, which is the most popular in fingerprint recognition systems. Various strategies are proposed in data embedding in order to maintain the accuracy of fingerprint recognition as well as the undetectability of data hiding. In bits replacement based data embedding, we replace the last few bits of each element of the original minutiae template with the data to be hidden. This strategy can be further improved using an optimized bits replacement based data embedding, which is able to minimize the impact of data hiding on the performance of fingerprint recognition. The third strategy is an order preserving mechanism which is proposed to reduce the detectability of data hiding. By using such a mechanism, it would be difficult for the attacker to differentiate the minutiae template with hidden data from the original minutiae templates. The experimental results show that the proposed data hiding scheme achieves sufficient capacity for hiding common personal data, where the accuracy of fingerprint recognition is acceptable after the data hiding

Memory-augmented Dialogue Management for Task-oriented Dialogue Systems

Dialogue management (DM) decides the next action of a dialogue system according to the current dialogue state, and thus plays a central role in task-oriented dialogue systems. Since dialogue management requires to have access to not only local utterances, but also the global semantics of the entire dialogue session, modeling the long-range history information is a critical issue. To this end, we propose a novel Memory-Augmented Dialogue management model (MAD) which employs a memory controller and two additional memory structures, i.e., a slot-value memory and an external memory. The slot-value memory tracks the dialogue state by memorizing and updating the values of semantic slots (for instance, cuisine, price, and location), and the external memory augments the representation of hidden states of traditional recurrent neural networks through storing more context information. To update the dialogue state efficiently, we also propose slot-level attention on user utterances to extract specific semantic information for each slot. Experiments show that our model can obtain state-of-the-art performance and outperforms existing baselines.Comment: 25 pages, 9 figures, Under review of ACM Transactions on Information Systems (TOIS