Split-Bregman iteration for framelet based image inpainting

AbstractImage inpainting plays a significant role in image processing and has many applications. Framelet based inpainting methods were introduced recently by Cai et al. (2007, 2009) [6,7,9] under an assumption that images can be sparsely approximated in the framelet domain. By analyzing these methods, we present a framelet based inpainting model in which the cost functional is the weighted ℓ1 norm of the framelet coefficients of the underlying image. The split-Bregman iteration is exploited to derive an iterative algorithm for the model. The resulting algorithm assimilates advantages while avoiding limitations of the framelet based inpainting approaches in Cai et al. (2007, 2009) [6,7,9]. The convergence analysis of the proposed algorithm is presented. Our numerical experiments show that the algorithm proposed here performs favorably

Smoothing algorithms for nonsmooth and nonconvex minimization over the stiefel manifold

We consider a class of nonsmooth and nonconvex optimization problems over the Stiefel manifold where the objective function is the summation of a nonconvex smooth function and a nonsmooth Lipschitz continuous convex function composed with an linear mapping. We propose three numerical algorithms for solving this problem, by combining smoothing methods and some existing algorithms for smooth optimization over the Stiefel manifold. In particular, we approximate the aforementioned nonsmooth convex function by its Moreau envelope in our smoothing methods, and prove that the Moreau envelope has many favorable properties. Thanks to this and the scheme for updating the smoothing parameter, we show that any accumulation point of the solution sequence generated by the proposed algorithms is a stationary point of the original optimization problem. Numerical experiments on building graph Fourier basis are conducted to demonstrate the efficiency of the proposed algorithms.Comment: 22 page

Comparative Transcriptomics of Strawberries (Fragaria spp.) Provides Insights into Evolutionary Patterns

Multiple closely related species with genomic sequences provide an ideal system for studies on comparative and evolutionary genomics, as well as the mechanism of speciation. The whole genome sequences of six strawberry species (Fragaria spp.) have been released, which provide one of the richest genomic resources of any plant genus. In this study, we first generated seven transcriptome sequences of Fragaria species de novo, with a total of 48,557–82,537 unigenes per species. Combined with 13 other species genomes in Rosales, we reconstructed a phylogenetic tree at the genomic level. The phylogenic tree shows that Fragaria closed grouped with Rubus and the Fragaria clade is divided into three subclades. East Asian species appeared in every subclade, suggesting that the genus originated in this area at ∼7.99 Mya. Four species found in mountains of Southwest China originated at ∼3.98 Mya, suggesting that rapid speciation occurred to adapt to changing environments following the uplift of the Qinghai–Tibet Plateau. Moreover, we identified 510 very significantly positively selected genes in the cultivated species F. × ananassa genome. This set of genes was enriched in functions related to specific agronomic traits, such as carbon metabolism and plant hormone signal transduction processes, which are directly related to fruit quality and flavor. These findings illustrate comprehensive evolutionary patterns in Fragaria and the genetic basis of fruit domestication of cultivated strawberry at the genomic/transcriptomic level

Radial junction Si micro/nano-wire array photovoltaics: Recent progress from theoretical investigation to experimental realization

Radial pn junction Si micro/nano-wire arrays exhibit unique optical and electrical characteristics for building photovoltaic devices with high performance-to-cost ratios over traditional planar junction bulk Si structures. Through optimizing the structural parameters, such as wire diameter and array periodicity, antireflection even superior to the optimized antireflective coatings can be realized. In the meantime, excellent light confinement is easily achievable for Si micro/nano-wire arrays using much less materials compared to their bulk Si counterparts. From the electrical aspect, the radial pn junction configuration formed around the wires significantly reduces the minority carrier collection length along the radial direction, providing outstanding tolerance to material qualities. Owing to these charming properties, radial junction Si micro/nano-wire array-based solar cells have been attracting extensive attention. The power conversion efficiency has also made huge progress from 12% in less than 10 years. With cell performance improvement, the number of research papers regarding theoretical understanding and optimization of the optical and electrical processes, experimental reports of the related solar cells has also surged, also including review papers. Accordingly, in this paper we are focusing on the recent progress, following a brief but systematic introduction to the related topic. Then the issues needing to be addressed for further improving the optical and electrical structures and cell performance are summarized. Following that, several other advanced solar cells employing Si micro/nano-wire arrays as a platform are introduced. ? 2014 Elsevier Ltd

Robot's remote real-time navigation controlled by smart phone

Conference Name:2012 IEEE International Conference on Robotics and Biomimetics, ROBIO 2012. Conference Address: Guangzhou, China. Time:December 11, 2012 - December 14, 2012.IEEE Robotics and Automation Society (RAS); South China University of Technology (SCUT); National Natural Science Foundation of China (NSFC); State Key Laboratory of Robotics and System, HIT; IEEE Systems, Man, and Cybernetics Society (SMC)This paper realizes robot remote real-time navigation system by using smart phone. The smart phone was used for the displayer and command receiver, and the control commands and compressed video stream was transmitted on Internet between the robot and smart phone, thus a real-time video feedback was developed. According to the situation of communication, the sending frame rate of the video and robot's velocity were adjusted automatically. Furthermore an obstacles picture and shake were designed on the smart phone to warm the dangerous closeness between robot and obstacles. Therefore, the security of the robot was enhanced and the defects were overcome that limited computational power, display screen, communication bandwidth and large network delay. Proved by experiment, this robot real-time navigation system was portable, flexible, simple to use and can be used anywhere at any time. 漏 2012 IEEE

New Energy Aggregators Optimal Dispatching Strategies Based on Price Incentive Agreement

The ubiquitous power Internet of things (UPIoT) can realize the wide interconnection of all links of the power system. Based on this background, this paper proposes the price incentive agreement of distributed new energy aggregators and establishes distributed dispatching architecture. Firstly, the information transmission matrix of distributed new energy aggregators with the property of double random matrix is established, and the distributed sub-gradient algorithm based on information transmission matrix is used to solve the distributed dispatching model of new energy aggregators. Finally, the feasibility and effectiveness of the optimization model and its solution method are analyzed through simulation examples, and the information interrupt, information error that may be encountered are also discussed