3D digital relief generation.

This thesis investigates a framework for generating reliefs. Relief is a special kind of sculptured artwork consisting of shapes carved on a surface so as to stand out from the surrounding background. Traditional relief creation is done by hand and is therefore a laborious process. In addition, hand-made reliefs are hard to modify. Contrasted with this, digital relief can offer more flexibility as well as a less laborious alternative and can be easily adjusted. This thesis reviews existing work and offers a framework to tackle the problem of generating three types of reliefs: bas reliefs, high reliefs and sunken reliefs. Considerably enhanced by incorporating gradient operations, an efficient bas relief generation method has been proposed, based on 2D images. An improvement of bas relief and high relief generation method based on 3D models has been provided as well, that employs mesh representation to process the model. This thesis is innovative in describing and evaluating sunken relief generation techniques. Two types of sunken reliefs have been generated: one is created with pure engraved lines, and the other is generated with smooth height transition between lines. The latter one is more complex to implement, and includes three elements: a line drawing image provides a input for contour lines; a rendered Lambertian image shares the same light direction of the relief and sets the visual cues and a depth image conveys the height information. These three elements have been combined to generate final sunken reliefs. It is the first time in computer graphics that a method for digital sunken relief generation has been proposed. The main contribution of this thesis is to have proposed a systematic framework to generate all three types of reliefs. Results of this work can potentially provide references for craftsman, and this work could be beneficial for relief creation in the fields of both entertainment and manufacturing

The existence of positive periodic solutions of a class of lotka-volterra type impulsive systems with infinitely distributed delay

AbstractIn this paper, the existence of positive periodic solutions of a class of periodic Lotka-Volterra type impulsive systems with distributed delays is studied. By using the continuation theorem of coincidence degree theory, a set of easily verifiable sufficient conditions are obtained, which improve and generalize some existing results

In-Place Gestures Classification via Long-term Memory Augmented Network

In-place gesture-based virtual locomotion techniques enable users to control their viewpoint and intuitively move in the 3D virtual environment. A key research problem is to accurately and quickly recognize in-place gestures, since they can trigger specific movements of virtual viewpoints and enhance user experience. However, to achieve real-time experience, only short-term sensor sequence data (up to about 300ms, 6 to 10 frames) can be taken as input, which actually affects the classification performance due to limited spatio-temporal information. In this paper, we propose a novel long-term memory augmented network for in-place gestures classification. It takes as input both short-term gesture sequence samples and their corresponding long-term sequence samples that provide extra relevant spatio-temporal information in the training phase. We store long-term sequence features with an external memory queue. In addition, we design a memory augmented loss to help cluster features of the same class and push apart features from different classes, thus enabling our memory queue to memorize more relevant long-term sequence features. In the inference phase, we input only short-term sequence samples to recall the stored features accordingly, and fuse them together to predict the gesture class. We create a large-scale in-place gestures dataset from 25 participants with 11 gestures. Our method achieves a promising accuracy of 95.1% with a latency of 192ms, and an accuracy of 97.3% with a latency of 312ms, and is demonstrated to be superior to recent in-place gesture classification techniques. User study also validates our approach. Our source code and dataset will be made available to the community.Comment: This paper is accepted to IEEE ISMAR202

A review of digital generation techniques

This paper reports the development of digital relief generation over recent years. Relief generation techniques are classified into three types, image-based techniques, direct modelling techniques, and those by transforming 3D shapes into reliefs. This work aims to assist artists and designers to develop an in-depth understanding of current state of the art in relief generation

Effects of the Interception of Litterfall by the Understory on Carbon Cycling in Eucalyptus Plantations of South China

For the purposes of forest restoration, carbon (C) fixation, and economic improvement, eucalyptus (Eucalyptus urophylla) has been widely planted in South China. The understory of eucalyptus plantations is often occupied by a dense community of the fern Dicranopteris dichotoma, which intercepts tree canopy leaf litter before it reaches the ground. To understand the effects of this interception of litterfall on C cycling in eucalyptus plantations, we quantified the mass of intercepted litter and the influences of litterfall interception on litter decomposition and soil respiration. The total mass of E. urophylla litterfall collected on the understory was similar to that collected by the traditional litter trap method. All of the eucalyptus litterfall is intercepted by the D. dichotoma canopy. Of the litterfall that was intercepted by D. dichotoma, 20–40% and 60–80% was intercepted by the top (50–100 cm) and bottom (0–50 cm) of the understory canopy, respectively. Intercepted litterfall decomposed faster at the bottom of understory canopy (at the base of the plants) than at the top, and decomposition was slower on the soil surface in the absence of understory than on any location in the understory canopy. Soil respiration was highest when both the understory and litter were present and was lowest when both the understory and litter were absent. These results indicate that litterfall interception changed carbon flow between aboveground and belowground through litter decomposition and soil respiration, which changed carbon cycling in eucalyptus plantations. The effects of the understory on litter decomposition and soil respiration should be considered in ecosystem carbon models

Masked Autoencoders in 3D Point Cloud Representation Learning

Transformer-based Self-supervised Representation Learning methods learn generic features from unlabeled datasets for providing useful network initialization parameters for downstream tasks. Recently, self-supervised learning based upon masking local surface patches for 3D point cloud data has been under-explored. In this paper, we propose masked Autoencoders in 3D point cloud representation learning (abbreviated as MAE3D), a novel autoencoding paradigm for self-supervised learning. We first split the input point cloud into patches and mask a portion of them, then use our Patch Embedding Module to extract the features of unmasked patches. Secondly, we employ patch-wise MAE3D Transformers to learn both local features of point cloud patches and high-level contextual relationships between patches and complete the latent representations of masked patches. We use our Point Cloud Reconstruction Module with multi-task loss to complete the incomplete point cloud as a result. We conduct self-supervised pre-training on ShapeNet55 with the point cloud completion pre-text task and fine-tune the pre-trained model on ModelNet40 and ScanObjectNN (PB\_T50\_RS, the hardest variant). Comprehensive experiments demonstrate that the local features extracted by our MAE3D from point cloud patches are beneficial for downstream classification tasks, soundly outperforming state-of-the-art methods ($93.4\%$ and $86.2\%$ classification accuracy, respectively).Comment: Accepted to IEEE Transactions on Multimedi

Comprehensive evaluation of green transportation in Chongqing main urban area based on sustainable development theory

Taking the main urban area of Chongqing as the research area, this paper combines the content of urban green transportation and sustainable development, characteristics of mountain cities and factors affecting green transportation. The relevant indexes of urban green traffic evaluation index system are screened by taking into account the availability of each indicator data, while a comprehensive evaluation index system of green traffic suitable for mountain cities is established. Analytic Hierarchy Process (AHP) and Information Entropy Method are used to determine the weight of each factor and the combination weight of each index in the urban traffic green evaluation index system. Then, the weights of the evaluation factors and indicators are combined and empowered. Combining ArcGIS software with evaluation model, data collection and evaluation of green traffic indicators are carried out in nine districts of Chongqing. Finally, suggestions and improvement measures are put forward to promote the development of green traffic in Chongqing

Product design lifecycle information model (PDLIM)

In response to rapidly changing market and customer needs, product design and development (PDD) is evolving into a human-centred and data-driven design paradigm. The design environment gets more open often involving crowdsourcing and the design process becomes more complex, considering product family design along product whole lifecycle development, and needing more data support. Therefore, it is critical to effectively capture, share, and manage design-related information in such a complex design environment. From this perspective, it is a prerequisite to have a proper product design lifecycle information model (PDLIM) to guide information gathering, sharing and management. To the best of our knowledge, currently, there lacks such a PDLIM to support effective PDD, though digital twin (DT) technology shows a great potential of supporting product lifecycle information collection and management. In this paper, the overall structure of the proposed PDLIM is firstly developed to frame in all main product lifecycle stages and the corresponding key phases for structurally capturing and storing necessary data along a product lifecycle. Secondly, key design information items against the main product lifecycle stages and their corresponding key phases are explored from literature reviews and case study analyses. Thirdly, the necessity of the identified information items in the PDLIM is qualitatively evaluated by two case studies. Finally, the PDLIM is further evaluated by applying formal object-role modelling (ORM) to demonstrate how design information items are used and interacted in exemplary design interaction scenarios, and to approve that it can be formally described and managed as an information model. The evaluation results show that the PDLIM is feasible to be adapted in a crowdsourcing-combined PDD process for supporting design management, reviewing, quality control, and next round product redesign and improvement

Evaluation of multicomponent recombinant vaccines against Actinobacillus pleuropneumoniae in mice

<p>Abstract</p> <p>Background</p> <p>Porcine contagious pleuropneumonia (PCP) is a highly contagious disease that is caused by <it>Actinobacillus pleuropneumoniae </it>(APP) and characterized by severe fibrinous necrotizing hemorrhagic pleuropneumonia, which is a severe threat to the swine industry. In addition to APP RTX-toxins I (ApxI), APP RTX-toxin II (ApxII), APP RTX-toxin III (ApxIII) and Outer membrane protein (OMP), there may be other useful antigens that can contribute to protection. In the development of an efficacious vaccine against APP, the immunogenicities of multicomponent recombinant subunit vaccines were evaluated.</p> <p>Methods</p> <p>Six major virulent factor genes of APP, i.e., <it>apxI</it>, <it>apxII</it>, <it>apxIII</it>, APP RTX-toxins IV (<it>apxIV</it>), <it>omp </it>and type 4 fimbrial structural (<it>apfa</it>) were expressed. BALB/c mice were immunized with recombinant ApxI ( rApxI), recombinant ApxII (rApxII), recombinant ApxIII (rApxIII) and recombinant OMP (rOMP) (Group I); rApxI, rApxII, rApxIII, recombinant ApxIV (rApxIV), recombinant Apfa (rApfa) and rOMP (Group II); APP serotype 1 (APP1) inactivated vaccine (Group III); or phosphate-buffered saline (PBS) (Control group), respectively. After the first immunization, mice were subjected to two booster immunizations at 2-week intervals, followed by challenge with APP1 Shope 4074 and APP2 S1536.</p> <p>Results</p> <p>The efficacy of the multicomponent recombinant subunit vaccines was evaluated on the basis of antibody titers, survival rates, lung lesions and indirect immunofluorescence (IIF) detection of APP. The antibody level of Group I was significantly higher than those of the other three groups (<it>P </it>< 0.05). The survival rate of Group I was higher than that of Groups II and III (<it>P </it>< 0.05) and the control (<it>P </it>< 0.01). Compared with the other three groups, the lungs of Group I did not exhibit obvious hemorrhage or necrosis, and only showed weak and scattered fluorescent dots by IIF detection.</p> <p>Conclusion</p> <p>The result indicates that the multicomponent recombinant subunit vaccine composed of rApxI, rApxII, rApxIII and rOMP can provide effective cross-protection against homologous and heterologous APP challenge.</p