High-Resolution Neural Face Swapping for Visual Effects

In this paper, we propose an algorithm for fully automatic neural face swapping in images and videos. To the best of our knowledge, this is the first method capable of rendering photo-realistic and temporally coherent results at megapixel resolution. To this end, we introduce a progressively trained multi-way comb network and a light- and contrast-preserving blending method. We also show that while progressive training enables generation of high-resolution images, extending the architecture and training data beyond two people allows us to achieve higher fidelity in generated expressions. When compositing the generated expression onto the target face, we show how to adapt the blending strategy to preserve contrast and low-frequency lighting. Finally, we incorporate a refinement strategy into the face landmark stabilization algorithm to achieve temporal stability, which is crucial for working with high-resolution videos. We conduct an extensive ablation study to show the influence of our design choices on the quality of the swap and compare our work with popular state-of-the-art methods.     

Online review manipulation by asymmetrical firms: Is a firm’s manipulation of online reviews always detrimental to its competitor?

Online reviews have a significant influence on consumers, and consequently firms are motivated to manipulate online reviews to promote their own products. This paper develops an analytical model to systematically explore the impact of online review manipulation on asymmetrical firms who sell substitutable search products in a competing market. Results show that a firm’s manipulation of online reviews is not necessary to hurt its competitor’s profit. In addition, if firms are free to choose whether to manipulate online reviews, both firms will always choose to manipulate online reviews. Moreover, there exists a prisoner’s dilemma in which online reviews are overmanipulated.     

基于声波的微粒操控型微流控芯片仿真分析

利用有限元仿真软件COMSOL,对基于声表面行波(tsaw)粒子分选芯片及体声波(baw)粒子富集芯片进行了分析并加以实验验证.在仿真软件中分别模拟声表面行波粒子分选芯片的声波传播、声场形成、粒子轨迹以及体声波粒子富集芯片的声场形成、粒子轨迹,分析其运作机理,对肉眼不可见的声波、声场分布做出可视化效果.实验结果说明这两种芯片基于不同原理,都可对微米级的硅球完成可控的操作,并对于后续的器件创新和优化打下基础.     

Semantic Segmentation for Line Drawing Vectorization Using Neural Networks

In this work, we present a method to vectorize raster images of line art. Inverting the rasterization procedure is inherently ill‐conditioned, as there exist many possible vector images that could yield the same raster image. However, not all of these vector images are equally useful to the user, especially if performing further edits is desired. We therefore define the problem of computing an instance segmentation of the most likely set of paths that could have created the raster image. Once the segmentation is computed, we use existing vectorization approaches to vectorize each path, and then combine all paths into the final output vector image. To determine which set of paths is most likely, we train a pair of neural networks to provide semantic clues that help resolve ambiguities at intersection and overlap regions. These predictions are made considering the full context of the image, and are then globally combined by solving a Markov Random Field (MRF). We demonstrate the flexibility of our method by generating results on character datasets, a synthetic random line dataset, and a dataset composed of human drawn sketches. For all cases, our system accurately recovers paths that adhere to the semantics of the drawings.     

Immunoregulation of Macrophages by Controlling Winding and Unwinding of Nanohelical Ligands

Developing materials with the capability of changing their innate features can help to unravel direct interactions between cells and ligand-displaying features. This study demonstrates the grafting of magnetic nanohelices displaying cell-adhesive Arg-Gly-Asp (RGD) ligand partly to a material surface. These enable nanoscale control of rapid winding (“W”) and unwinding (“UW”) of their nongrafted portion, such as directional changes in nanohelix unwinding (lower, middle, and upper directions) by changing the position of a permanent magnet while keeping the ligand-conjugated nanohelix surface area constant. The unwinding (“UW”) setting cytocompatibility facilitates direct integrin recruitment onto the ligand-conjugated nanohelix to mediate the development of paxillin adhesion assemblies of macrophages that stimulate M2 polarization using glass and silicon substrates for in vitro and in vivo settings, respectively, at a single cell level. Real time and in vivo imaging are demonstrated that nanohelices exhibit reversible unwinding, winding, and unwinding settings, which modulate time-resolved adhesion and polarization of macrophages. It is envisaged that this remote, reversible, and cytocompatible control can help to elucidate molecular-level cell–material interactions that modulate regenerative/anti-inflammatory immune responses to implants.     

Manipulating the Light-Matter Interaction of PtS/MoS2 p–n Junctions for High Performance Broadband Photodetection

Due to the limited carrier concentration, 2D transition metal dichalcogenides have lower intrinsic dark current, and thus, are widely studied for high performance room photodetection. However, the light-matter interaction is still unclear, thus tuning the photoexcitation and further manipulating the photodetection is a challenge. Herein, large-area PtS films are synthesized, and the growth mechanism is investigated. It is demonstrated that PtS has an orthorhombic structure and exhibits the p-type semiconducting behavior. Then, MoS₂/PtS p–n heterojunction is fabricated, and its energy diagram is discussed based on the Kelvin probe force microscopy. The contact potential difference is about 160 mV, which is much larger than previous 2D junctions facilitating the charge separation. Furthermore, the phototransistor based on MoS₂/PtS p–n heterojunction is prepared, showing broadband photoresponse from visible to near-infrared. The manipulation of an external field on photoresponse, detectivity, and rise/fall time are explored and discussed. The responsivity can reach up to 25.43 A W⁻¹, and the detectivity is 8.54 × 10¹² Jones. These results indicate that PtS film is a prospective candidate for high-performance optoelectronic devices and broaden the scope of infrared detection materials.     

Purely Electrical Controllable Complete Spin Logic in a Single Magnetic Heterojunction

Fully electrical manipulation of magnetism, preferably through spin current, is highly desired to achieve energy-efficient, nonvolatile, and programmable spin logic devices. It is demonstrated in this study that in a single Pt/IrMn/Co/Ru/CoPt heterojunction, all 16 Boolean logic functions can be realized in a purely electrical way, relying on electrical manipulation of magnetic-field-free spin-orbit torque (SOT) switching. By applying current pulses along with two orthogonal directions, the exchange bias between IrMn and Co, and the SOT switching polarity (clockwise or counterclockwise) of perpendicularly magnetized CoPt, can be reversibly controlled, enabling complete spin logic within a single nonvolatile memory. This study makes a significant step towards practical electrical programmable spin logic devices.     

基于深度强化学习的机器人操作行为研究综述

通过梳理、总结前人的研究,首先对深度学习和强化学习的基本理论和算法进行介绍,进而对深度强化学习的流行算法和在机器人操作领域的应用现状进行综述。最后,根据目前存在的问题及解决方法,对深度强化学习在机器人操作领域未来的发展方向作出总结与展望。     

Redundancy modelling and resolution for robotic mobile manipulators: a general approach

In this work the topic of kinematic redundancy modelling and resolution for robotic mobile manipulators is considered. A set of redundancy parameters is introduced to define a general inverse kinematic procedure for mobile manipulators. Then, redundancy is treated as a non-linear optimization problem with the purpose of finding robot configurations that maximize the designed metric measures. Some strategies to design the optimization objective function are introduced in order to achieve desirable redundant behaviours, such as obstacles avoidance, mobile base motions reductions and dexterity optimization. Moreover, the robot controller has been developed following an object-oriented software architecture principle that allows to keep it general and robot independent. As a prove of reliability and generality of our approach, the same controller has been used to control several different mobile manipulators in a simulation environment, as well as a real KUKA youBot robot.     

Growth and Smoltification of Three Norwegian Strains of Atlantic Salmon Salmo salar Reared under Different Thermal Regimes

A comparative study was performed with juvenile Atlantic salmon Salmo salar from three stocks in Western Norway that differ in their natural conditions. One is from warm, lowland river conditions (Årdal), one is from cold glacial river conditions (Stryn) and the last one (Suldalslågen) is from a hydropower‐regulated river. The salmon parr were tagged and reared at 4, 5.5 and 7 °C and simulated natural water temperature (SNT) for river Suldalslågen. Size distribution was unimodal at 4 °C, with a change to a bimodal distribution, representing potential 1+ and 2+ smolts, at the other temperature regimes. The relative biomass of 1+ smolts varied between the stocks as Stryn (cold glacial river) stock had the highest number of smolts at 7 °C and the Suldalsågen stock (hydropower‐regulated river) displaying the highest number at the SNT regime. Overall, the Stryn stock, originating from cold river conditions, seemed to be well adapted to growth and smoltification at cold temperatures, whereas salmon parr from river Suldalslågen seem to be better adapted to the natural temperature regime (SNT) of this river than the other two stocks. This was reflected in the gill Na⁺,K⁺‐ATPase as the Suldalslågen stock showed increasing activity from 16 April (4.2 µmol ADP mg protein^?1 h^?1) to 10 May (9.2 µmol ADP mg protein^?1 h^?1), and at the end of the experiment, enzyme activity in Suldalslågen stock was significantly higher than both Stryn (5.7) and Årdal (5.9 µmol ADP mg protein^?1 h^?1) stock. In contrast, the warm lowland stock, Årdal, fish had low Na⁺,K⁺‐ATPase activity with no distinct peak at any of the sampled dates from March through May. Copyright © 2016 John Wiley & Sons, Ltd.