Learning to Warp for Style Transfer

Since its inception in 2015, Style Transfer has focused on texturing a content image using an art exemplar. Recently, the geometric changes that artists make have been acknowledged as an important component of style[42], [55], [62], [63]. Our contribution is to propose a neural network that, uniquely, learns a mapping from a 4D array of inter-feature distances to a non-parametric 2D warp field. The system is generic in not being limited by semantic class, a single learned model will suffice; all examples in this paper are output from one model.Our approach combines the benefits of the high speed of Liu et al. [42] with the non-parametric warping of Kim et al. [55]. Furthermore, our system extends the normal NST paradigm: although it can be used with a single exemplar, we also allow two style exemplars: one for texture and another geometry. This supports far greater flexibility in use cases than single exemplars can provide

Geometric and Textural Augmentation for Domain Gap Reduction

Research has shown that convolutional neural networks for object recognition are vulnerable to changes in depiction because learning is biased towards the low-level statistics of texture patches. Recent works concentrate on improving robustness by applying style transfer to training examples to mitigate against over-fitting to one depiction style. These new approaches improve performance, but they ignore the geometric variations in object shape that real art exhibits: artists deform and warp objects for artistic effect. Motivated by this observation, we propose a method to reduce bias by jointly increasing the texture and geometry diversities of the training data. In effect, we extend the visual object class to include examples with shape changes that artists use. Specifically, we learn the distribution of warps that cover each given object class. Together with augmenting textures based on a broad distribution of styles, we show by experiments that our method improves performance on several cross-domain benchmarks

Static, dynamic mechanical and fatigue properties of cement-asphalt mortars

High-speed railway or rail (HSR) is a hot topic all over the contemporary world. And there is a growing tendency towards the application of nonballasted or slab tracks in HSR. Cement-asphalt mortar (CAM), a composite of Portland cement and asphalt emulsion, is widely used as a cushion layer in the two prevailing prefabricated concrete slab tracks of HSR in China, namely CRTS I and CRTS II. After a few years’ operation and service, however, premature cracking has been identified in the CAM layer along part of CRTS I and CRTS II. This is mainly caused by the fatigue of CAMs under repetitive traffic loading, that is, mechanical fatigue. In this research work, therefore, static, dynamic mechanical and most importantly, fatigue properties of the two typical CAMs, namely CAM-I and CAM-II, were investigated. Using a 4-point bending (4PB) test method, static or quasi-static mechanical properties of these two CAMs were studied. Results indicated that the 4PB test method was suitable for characterising their static bending properties in the laboratory, and more reliable results could be obtained, especially on modulus of elasticity, compared to the compression test method which was usually used for formulation design and quality evaluation. However, irrespective of the test methods used, CAM-I and CAM-II were found to be distinctively different in their static mechanical properties and behaviour at room temperature, due to the changes in the microstructures of their binding materials, cement-asphalt binder (CABs), used in CAMs at different A/Cs. The primary functions of CAMs as the cushion layer in CRTS I and II, especially damping, had been demonstrated to be in close relation to their viscoelasticity. Based on the DMA method, the temperature spectra of dynamical modulus and loss factors of CAMs or CABs were obtained to characterise their temperature susceptibility and viscoelasticity, respectively. On the temperature spectrum of CAM-I, the two characteristic temperatures of the asphalt binder, Tg implied to be around -20 °C and TR&B measured to be 48 °C, could be determined, andthese two not only defined the viscoelastic zone for CAM-I and the immediate temperature range for the fatigue tests of CAM-I, but also the two boundaries of service temperatures for CAM-I and CAM-II under traffic loads. The higher A/C caused a decrease in dynamic modulus of CAMs but an increase in their loss factors and temperature susceptibility, and a balance should be considered between them in the future design of new CAMs. For the first time, 4PB fatigue of CAM-I and CAM-II were investigated using two different fatigue test schemes, and the results indicated that, in terms of the fatigue behaviour, the CAM-I can be considered as a cement-modified asphalt mortar whilst CAM-II an asphalt-modified cement mortar. Therefore, it is preferable to use the asphalt mixture-based fatigue test configuration for CAM-I and this fatigue test scheme was an ideal one to be used. Additionally, it was found that low temperature was beneficial to the fatigue life of CAM-I whereas high temperature was detrimental to its fatigue life. On the other hand, the fatigue test configuration of cement-based materials including plain concretes is favourable to use for CAM-II but might not suitable for CAM-II, especially when the influence of the reversal stress, R, or the test temperature was separately considered. Different from plain concrete materials, the reversal stress or the test temperature had a significant impact on the fatigue life of CAM-II. Higher temperature would greatly reduce its fatigue life, and this temperature should not be higher than TR&B of the asphalt binder used. Much longer fatigue life of CAM-II was observed under low temperatures if the same stress, instead of normalised stress level, was applied, and CAM-II was more like plain concretes when temperature fell to around Tg of the asphalt binder

Experimental study on the wave measurements of wave buoys

Wave measurement is of vital importance for assessing the wave power resources and for developing wave energy devices, especially for the wave energy production and the survivability of the wave energy device. Wave buoys are one of the most popular measuring technologies developed and used for long-term wave measurements. In order to figure out whether the wave characteristics can be recorded by using the wave buoys accurately, an experimental study was carried out on the performance of three wave buoy models, viz two WaveScan buoys and one ODAS buoy, in a wave tank using the European FP7 MARINET facilities. This paper presents the test results in both time and frequency domains and the comparison between the wave buoys and wave gauge measurements. The analysis results reveal that for both regular and irregular waves, the WaveScan buoys have better performances than the ODAS buoy in terms of accuracy and the WaveScan buoys measurements have a very good correlation with those from the wave gauges

4-(5-tert-Butyl-1,3-dithian-2-yl)-5-chloro-2-phenyl-1,3-oxazole

In the title mol­ecule, C17H20ClNOS2, the phenyl and oxazole rings are nearly coplanar with an average deviation of 0.022 Å from the mean plane (M). The 1,3-dithiane ring adopts a chair conformation and is twisted in such a way that the C—CBu fragment lies in M (deviations are 0.031 and 0.010 Å, respectively, for the two C atoms)