Self-Adversarially Learned Bayesian Sampling

Scalable Bayesian sampling is playing an important role in modern machine learning, especially in the fast-developed unsupervised-(deep)-learning models. While tremendous progresses have been achieved via scalable Bayesian sampling such as stochastic gradient MCMC (SG-MCMC) and Stein variational gradient descent (SVGD), the generated samples are typically highly correlated. Moreover, their sample-generation processes are often criticized to be inefficient. In this paper, we propose a novel self-adversarial learning framework that automatically learns a conditional generator to mimic the behavior of a Markov kernel (transition kernel). High-quality samples can be efficiently generated by direct forward passes though a learned generator. Most importantly, the learning process adopts a self-learning paradigm, requiring no information on existing Markov kernels, e.g., knowledge of how to draw samples from them. Specifically, our framework learns to use current samples, either from the generator or pre-provided training data, to update the generator such that the generated samples progressively approach a target distribution, thus it is called self-learning. Experiments on both synthetic and real datasets verify advantages of our framework, outperforming related methods in terms of both sampling efficiency and sample quality.Comment: AAAI 201

Preliminary study of karst collapse

[cat] L'objecte d'aquest treball és analitzar diversos mètodes de predicció d'enfonsaments càrstics. S'estableixen dos models de predicció, en diferents condicions, d'acord amb el principi d'equilibri límit. Es contrasten ambdós models amb les dades procedents de Yulin, Guilin, Guangxi i d'altres llocs. Els resultats de l’aplicació d'aquests models mostren l’existència de concordància entre el resultat calculat pel model i la realitat. Així, els dos models es poden usar en la predicció d'abisaments càrstics i en l’estimació de l’estabilitat de la cobertura superficial del terreny. Aquesta nota s'ocupa detalladament de la relació entre els models i els factors que influeixen en ells, en base a la situació dels coneixements actuals; també s'apunta, més generalment, el contingut dels esmentats mètodes quant a la predicció d'eventuals abisaments. Per acabar, la predicció d'enfonsaments ha estat realitzada a San Lidian, Guilin, Guangxi, usant els dos models.[eng] The object of this paper is to discuss forecast methods of karst collapse. According to limit equilibrium principle two collapse forecast models are established in different conditions of the level. Two models are checked by the data in Yulin, Guilin of Guangxi and other places. The checking result show to be consistency between the calculating result by the model and reality. So the two models can be used in forecast of karst collapse and estimation of the cover stability. The paper dealt in detail with the relationship between the model and its affecting factors in the light of actually situation and also generally point out the collapse forecast content. Finally the collapse forecast is carried out using the two models in San Lidian, Guilin, Guangx

Giant congenital lower lip nevus restored by local advanced skin flap: a case report

INTRODUCTION: A congenital lower lip nevus is common, but a lower lip length lesion of more than 40% is hard to excise simply, without any distortion. We designed a lower lip bilateral advanced skin flap to restore the wound surface after completely and successfully removing the nevus. CASE PRESENTATION: A 13-year-old Mongolian girl was referred to us with a giant congenital lower lip nevus. The lesion covered nearly half of her lower lip. We designed a lower lip bilateral advanced skin flap to restore the wound surface, after completely removing the nevus without advanced repair. CONCLUSIONS: This case report demonstrates a case of a lower lip length defect of more than 40%, repaired by direct closure without dysfunction. It was a successful attempt that minimized the subsequent scar and dysfunction

Tunable Fano Resonances Based on Two-beam Interference in Microring Resonator

In this paper, a resonant system is demonstrated on silicon-on-insulator wafer to achieve tunable Fano resonances. In this system, the Fano resonance originates from the interference of two beams resonant in the microring resonator. The shapes of the Fano resonances are tunable through controlling the phase difference of the two beams. Both large slope and high extinctionratio (ER) are obtained when the phase difference is 0.5π or 1.5π. Experimental results show that Fano resonances with steep slope and ER over 20 dB are achieved in the whole free spectral range by controlling the microheaters to meet the phase condition

An interactive image segmentation method in hand gesture recognition

In order to improve the recognition rate of hand gestures a new interactive image segmentation method for hand gesture recognition is presented, and popular methods, e.g., Graph cut, Random walker, Interactive image segmentation using geodesic star convexity, are studied in this article. The Gaussian Mixture Model was employed for image modelling and the iteration of Expectation Maximum algorithm learns the parameters of Gaussian Mixture Model. We apply a Gibbs random field to the image segmentation and minimize the Gibbs Energy using Min-cut theorem to find the optimal segmentation. The segmentation result of our method is tested on an image dataset and compared with other methods by estimating the region accuracy and boundary accuracy. Finally five kinds of hand gestures in different backgrounds are tested on our experimental platform, and the sparse representation algorithm is used, proving that the segmentation of hand gesture images helps to improve the recognition accuracy

Chemical Vapor Deposition of High-Quality Large-Sized MoS2 Crystals on Silicon Dioxide Substrates

Large???sized MoS2 crystals can be grown on SiO2/Si substrates via a two???stage chemical vapor deposition method. The maximum size of MoS2 crystals can be up to about 305 ??m. The growth method can be used to grow other transition metal dichalcogenide crystals and lateral heterojunctions. The electron mobility of the MoS2 crystals can reach ???30 cm2 V???1 s???1, which is comparable to those of exfoliated flakes.ope