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Multi-resolution texture synthesis from turntable image sequences

Xuedong WANG, Xiaojun WU, Xiaorong ZHANG

《机械工程前沿(英文)》 2012年 第7卷 第1期   页码 72-80 doi: 10.1007/s11465-012-0305-8

摘要:

Texture synthesis and texture mapping are important technologies for rendering realistic three-dimensional scene. It has been widely used in virtual reality, urban modeling, 3D animation, gaming and other areas. In this paper, we propose a fast method to construct high quality texture map for multi-resolution texture synthesis from turntable image sequences. Given a 3D mesh model, we first get the projection relationship between 3D mesh and image sequences. We then use image sequences to construct a texture triangle for each 3D triangle mesh and get a global rectangular texture map for the whole mesh. Another approach to construct a texture map is using Stretch-minimizing mesh parameterization. Finally, we map the texture to mesh model to verify the quality of these two methods. The high performance of this method has been demonstrated in many real object models.

关键词: texture synthesis     multi-resolution     texture map     texture mapping    

Study on micro-texture and skid resistance of aggregate during polishing

Zhenyu QIAN, Lingjian MENG

《结构与土木工程前沿(英文)》 2017年 第11卷 第3期   页码 346-352 doi: 10.1007/s11709-017-0409-7

摘要: The skid resistance performance of pavement is closely related to the micro-texture of pavement aggregate, while there is very few research on the relationship between micro-texture and the skid resistance. In this paper, the optical microscope is used to acquire the surface morphology of three types of aggregates including basalt, limestone and red sandstone respectively, where a total of 12 indicators are developed based on the surface texture information. The polishing effect on aggregate is simulated by Wehner/Schulze (W/S) device, during the polishing procedure, the skid resistance are measured by British Pendulum Tester (BPT). Based on the results of independent T-test and the polishing resistance analysis, it shows that the surface texture of basalt is significantly different between limestone and red sandstone. Three indicators including the average roughness ( ), the kurtosis of the surface ( ) and the mean summit curvature ( ) are selected to describe the characteristics of aggregate micro-texture based on the correlation analysis. The contribution of micro-texture to the skid resistance can be described with the secondary polynomial regression model by these indicators.

关键词: skid resistance of pavement     micro-texture     aggregates     polishing test    

Multi-objective optimization of surface texture for the slipperswash plate interface in EHA pumps

《机械工程前沿(英文)》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0704-4

摘要: Well-designed surface textures can improve the tribological properties and the efficiency of the electro-hydrostatic actuator (EHA) pump under high-speed and high-pressure conditions. This study proposes a multi-objective optimization model to obtain the arbitrarily surface textures design of the slipper/swash plate interface for improving the mechanical and volumetric efficiency of the EHA pump. The model is composed of the lubrication film model, the component dynamic model considering the spinning motion, and the multi-objective optimization model. In this way, the arbitrary-shaped surface texture with the best comprehensive effect in the EHA pump is achieved and its positive effects in the EHA pump prototype are verified. Experimental results show a reduction in wear and an improvement in mechanical and volumetric efficiency by 1.4% and 0.8%, respectively, with the textured swash plate compared with the untextured one.

关键词: electro-hydrostatic actuator     axial piston pump     slipper/swash plate interface     multi-objective optimization     surface texture    

Effect of steady shear on multi-axial texture of symmetric diblock copolymers

XU Hui, LIU Honglai, HU Ying

《化学科学与工程前沿(英文)》 2007年 第1卷 第1期   页码 26-34 doi: 10.1007/s11705-007-0006-8

摘要: The effect of steady shear on multi-axial texture of symmetric diblock copolymer was investigated by using dynamic density functional theory. Through modifying the periodic boundary condition, the parallel-transverse biaxial texture and perpendicular-parallel-transverse triaxial texture have been observed. In the formation of the multi-axial texture, there are two critical velocities μ and µ, at which the transition between the perpendicular and the parallel lamellar morphology, and the transition between the parallel and the transverse lamellar morphology occur, respectively. The two critical velocities increase as the interaction parameter increases, but they almost remain constant at different shear rates. Furthermore, the rotation from the transverse lamellae to the parallel lamellae induced by the shear strain, and the increase of lamellar spacings of the three lamellae after removing the shear, have also been observed by the time evolution of the morphologies. These phenomena are consistent with experimental work.

The effect of texture and irrigation on the soil moisture vertical-temporal variability in an urban artificial

Xiaofeng ZHANG,Xu ZHANG,Guanghe LI

《环境科学与工程前沿(英文)》 2015年 第9卷 第2期   页码 269-278 doi: 10.1007/s11783-014-0672-y

摘要: Soil moisture variability in natural landscapes has been widely studied; however, less attention has been paid to its variability in the urban landscapes with respect to the possible influence of texture stratification and irrigation management. Therefore, a case study was carried out in the Beijing Olympic Forest Park to continuously monitor the soil in three typical profiles from 26 April to 11 November 2010. The texture stratification significantly affected the vertical distribution of moisture in the non-irrigated profile where moisture was mostly below field capacity. In the profile where irrigation was sufficient to maintain moisture above field capacity, gravity flow led to increased moisture with depth and thus eliminated the influence of texture. In the non-irrigated sites, the upper layer (above 80 cm) exhibited long-term moisture persistence with the time scale approximating the average rainfall interval. However, a coarse-textured layer weakened the influence of rainfall, and a fine-textured layer weakened the influence of evapotranspiration, both of which resulted in random noise-like moisture series in the deeper layers. At the irrigated site, frequent irrigation neutralized the influence of evapotranspiration in the upper layer (above 60 cm) and overshadowed the influence of rainfall in the deeper layer. As a result, the moisture level in the upper layer also behaved as a random noise-like series; whereas due to deep transpiration, the moisture of the deep layer had a persistence time-scale longer than a month, consistent with characteristic time-scales found for deep transpiration.

关键词: moisture vertical distribution     moisture temporal variation     texture stratification     irrigation     meteorological forcing     urban landscape    

Application of MoS in the space environment: a review

《机械工程前沿(英文)》 2023年 第18卷 第3期 doi: 10.1007/s11465-023-0755-1

摘要: A considerable portion of space mechanism failures are related to space tribological problems. Cold welding in high vacuum; surface erosion and collision damage caused by various radiations, high temperature oxidation under atomic oxygen (AO) bombardment; and thermal stress caused by temperature alternation all alter the physical, chemical, and friction properties of materials. In particular, the space vibration caused by alternating temperatures and microgravity environments can alter the motion of the contact body, further affecting its friction properties. Improving the friction properties of contact surfaces in the space environment is an important way to extend the service life of spacecraft. Traditional lubricants can no longer meet the lubrication requirements of the space environment. This study describes the characteristics of the space environment and the applications of solid lubricants. The friction properties of MoS2, a solid lubricant widely used in space, are discussed. The synergistic lubrication of MoS2 with surface textures or metals is presented. Advances in research on the friction properties of collision sliding contacts in the space environment are reviewed. The combination of MoS2 and soft metals with surface textures is introduced to reduce the effects of vibration environments on the friction properties of moving parts in space mechanisms. Finally, the challenges and future research interests of MoS2 films in space tribology are presented.

关键词: MoS2     soft metal     space environment     surface texture     synergistic effect     vibration    

Laboratory and field evaluation of asphalt pavement surface friction resistance

Zhong WU, Chris ABADIE

《结构与土木工程前沿(英文)》 2018年 第12卷 第3期   页码 372-381 doi: 10.1007/s11709-017-0463-1

摘要:

Pavement surface friction is a significant factor for driving safety and plays a critical role in reducing wet-pavement crashes. However, the current asphalt mixture design procedure does not directly consider friction as a requirement. The objective of this study was to develop a surface friction prediction model that can be used during a wearing course mixture design. To achieve the objective, an experimental study was conducted on the frictional characteristics of typical wearing course mixtures in Louisiana. Twelve wearing course mixtures including dense-graded and open-graded mixes with different combinations of aggregate sources were evaluated in laboratory using an accelerated polishing and testing procedure considering both micro- and macro texture properties. In addition, the surface frictional properties of asphalt mixtures were measured on twenty-two selected asphalt pavement sections using different in situ devices including Dynamic Friction Tester (DFT), Circular Texture Meter (CTM), and Lock-Wheel Skid Trailer (LWST). The results have led to develop a procedure for predicting pavement end-of-life skid resistance based on the aggregate blend polish stone value, gradation parameters, and traffic, which is suited in checking whether the selected aggregates in a wearing course mix design would meet field friction requirements under a certain design traffic polishing.

关键词: friction skid resistance     polishing     PSV     LWST     micro-texture     macro-texture    

Multiple input self-organizing-map ResNet model for optimization of petroleum refinery conversion units

《化学科学与工程前沿(英文)》 2023年 第17卷 第6期   页码 759-771 doi: 10.1007/s11705-022-2269-5

摘要: This work introduces a deep-learning network, i.e., multi-input self-organizing-map ResNet (MISR), for modeling refining units comprised of two reactors and a separation train. The model is comprised of self-organizing-map and the neural network parts. The self-organizing-map part maps the input data into multiple two-dimensional planes and sends them to the neural network part. In the neural network part, residual blocks enhance the convergence and accuracy, ensuring that the structure will not be overfitted easily. Development of the MISR model of hydrocracking unit also benefits from the utilization of prior knowledge of the importance of the input variables for predicting properties of the products. The results show that the proposed MISR structure predicts more accurately the product yields and properties than the previously introduced self-organizing-map convolutional neural network model, thus leading to more accurate optimization of the hydrocracker operation. Moreover, the MISR model has smoother error convergence than the previous model. Optimal operating conditions have been determined via multi-round-particle-swarm and differential evolution algorithms. Numerical experiments show that the MISR model is suitable for modeling nonlinear conversion units which are often encountered in refining and petrochemical plants.

关键词: hydrocracking     convolutional neural networks     self-organizing map     deep learning     data-driven optimization    

A bacterial artificial chromosome-based physical map of

Yuhua FU,Zhiqiang XIA,Shujuan WANG,Xin CHEN,Cheng LU,Mingcheng LUO,Hongbin ZHANG,Wenquan WANG

《农业科学与工程前沿(英文)》 2016年 第3卷 第4期   页码 321-329 doi: 10.15302/J-FASE-2016124

摘要: Cassava ( ) is known as the third most important food crop in the tropics and also used for industrial feedstock for biofuels. Two new bacterial artificial chromosome (BAC) libraries were constructed for W14 ( ssp. ), a wild ancestor of domesticated cassava. The libraries were constructed with RI and dIII insertion vectors, respectively. The RI library has 29952 clones with an average insert size of 115 kb, while the dIII library consists of 29952 clones with an average insert of 129 kb. The combined libraries contain a total of 59904 clones with an average insert size of 125 kb, representing approximately 10 × haploid genome equivalents. A total of 29952 clones were fingerprinted and resulted in a cassava physical map composed of 2485 contigs with an average physical length of 336 kb and 2909 singletons, representing approximately 762 Mb of the cassava genome. 5000 clones located at the ends of BAC contigs were selected and sequenced. A total of 6077 SNPs and 231 indels were identified, that covered 459 gene sequences, of which 6 genes were associated with starch and sucrose metabolism. This BAC-based physical map provides valuable tools to understand the genetics and evolution of cassava.

关键词: cassava     BAC library     physical map    

自动驾驶地图有关政策的思考和建议

刘经南,董杨,詹骄,高柯夫

《中国工程科学》 2019年 第21卷 第3期   页码 92-97 doi: 10.15302/J-SSCAE-2019.03.004

摘要:

自动驾驶地图作为实现汽车自动驾驶的关键基础设施,对于推动我国自动驾驶领域的商业化开发至关重要。现阶段,我国受地图测绘、应用和监管等相关法律法规的制度掣肘,在自动驾驶地图的产业化进程方面相对滞后。为此,本文着重分析了我国在自动驾驶地图开发、应用和管理中面临的主要政策法规问题:自动驾驶地图是否需加密的问题、自动驾驶地图部分地理信息表达受限的问题、自动驾驶地图地理信息采集资质和审图流程的问题、自动驾驶地图事故责任和保险问题、自动驾驶地图相关测试规范和测试场景问题。同时结合国内外自动驾驶领域的发展趋势,给出加快我国自动驾驶汽车开发和商业化进程的四点建议:制定自动驾驶地图管理模式、允许自动驾驶地图应用试点及有序开放、适当放开企业权限及优化审核流程、建立国家级自动驾驶地图平台。

关键词: 自动驾驶地图     自动驾驶法规     自动驾驶政策    

用航空航天影像更新地形图地物要素的栅格化方法

林宗坚

《中国工程科学》 2000年 第2卷 第4期   页码 43-47

摘要:

文章针对当前我国1:5和1:1万地形图更新的大规模生产的迫切需求,提出在原有地形图栅格式数字化的基础上,叠加经过精密纠正配准的航空或卫星遥感影像,以栅格方式更新地物要素的全过程方法。文中特别阐述了:1)地形图栅格数字化不同于矢量数字化的扫描采样分辨率问题;2)区别于传统的“针孔式”控制点概念的图像图形阵列控制点技术;3)由于DEM(数字高程模型)数据缺乏或精度不足引起的航空航天影像与地形图图形配准误差的局部纠正方法;4)定性指导定量的影像判读方法;5)从遥感影像提取地物结构信息的半自动化方法。文章最后列出

关键词: 测绘遥感     地形图更新     数字栅格地图    

基于纹理及小波分析的车牌定位方法

黄卫,路小波,余彦翔,凌小静

《中国工程科学》 2004年 第6卷 第3期   页码 19-24

摘要:

提出了一种基于纹理和小波分析的车牌定位方法。针对图像背景复杂,且车牌所占比例较小的特点,提出了一种确定基元分类阈值的二值化方法;根据车牌字符分布规律,提出了二值纹理基元分析方法,提取车牌候选区域;基于小波分析提取车牌区域竖笔画特征,采用隶属度定量表征车牌竖笔画特征、位置特征及形状特征,给出综合这些特征、从候选区域提取车牌区域的方法。测试结果表明,该方法正确定位率超过96%

关键词: 纹理     小波分析     基元     车牌定位    

Optimization of process parameters for mature landfill leachate pretreatment using MAP precipitation

Wei LI, Xiaowen DING, Min LIU, Yuewen GUO, Lei LIU

《环境科学与工程前沿(英文)》 2012年 第6卷 第6期   页码 892-900 doi: 10.1007/s11783-012-0440-9

摘要: Chemical precipitation is a useful technology as a pretreatment to treat mature landfill leachate with high concentrations of ammonium-nitrogen ( ) and refractory organic compounds. Orthogonal experiments and factorial experiments were carried out to determine the optimal conditions enhancing the magnesium ammonium phosphate (MAP) precipitation process, and the experimental results demonstrated that the removal rate of was more than 85% when MgO and NaH PO ·2H O were applied as external sources of magnesium and phosphorous under the optimal conditions that molar ratio n(Mg)∶n(N)∶n(P) = 1.4∶1∶0.8, reaction time 60 min, original pH of leachate and settling time 30 min. In the precipitation process, pH could be maintained at the optimal range of 8–9.5 because MgO could release hydroxide ions to consume hydrogen ions. Calcium ions and carbonate ions existed in the leachate could affect the precipitation process, which resulted in the decrease of removal efficiency. The residues of MAP sediments decomposed by heating under alkaline conditions can be reused as the sources of phosphorous and magnesium for the removal of high concentrations of , and up to 90% of ammonium could be released under molar ratio of n[OH]∶n[MAP] = 2.5∶1, heating temperature 90°C and heating time 2h.

关键词: magnesium ammonium phosphate precipitation     mature landfill leachate     optimization     ammonium-nitrogen    

腌制工艺对大菱鲆质构及理化性质的影响

王甜甜,李振兴,林洪,郭晓华

《中国工程科学》 2014年 第16卷 第9期   页码 64-68

摘要:

本文通过分析腌制大菱鲆质构及理化指标的变化,研究食盐浓度、腌制时间和腌制方式等对腌制大菱鲆品质的影响。结果表明:食盐浓度和腌制时间对腌制大菱鲆咀嚼度影响显著(P<0.05),对硬度、弹性和胶黏性无显著影响;腌制方式对腌制品的硬度、弹性和胶黏性影响显著(P<0.05),对咀嚼度无显著影响。在腌制过程中,食盐浓度每增加2 %,酸价降低1.03 mg/g,过氧化值平均降低0.1 g/100 g;腌制时间越长,酸价和过氧化值均有所升高;对感官评价来说,腌制时间有比较显著的影响(P<0.05)。由此可知,腌制工艺对大菱鲆产品的品质有显著的影响,本文通过分析各参数的影响,为进一步优化大菱鲆腌制工艺提供基础数据。

关键词: 腌制工艺     大菱鲆     质构     理化性质     感官评价    

Optimization of fuel supply map during starting process of electronic controlled diesel engine

LIANG Jinguang, YU Xiumin, GAO Yue, WANG Yunkai, YU Hongyang, Gong Baoli

《能源前沿(英文)》 2008年 第2卷 第4期   页码 410-415 doi: 10.1007/s11708-008-0080-8

摘要: Tests were conducted to study influence of fuel supply map during the starting process of an electronic controlled diesel engine using an electronic controlled diesel engine which was made up of a CA498Z diesel engine, a VP37 electronic controlled distributor injection pump management system and a VS100 calibration system. The calibration process of starting fuel supply map was educed under the principle of low HC emission and rapid starting velocity. The calibration methods of starting fuel supply map were obtained.

关键词: supply     management     CA498Z     process     controlled distributor    

标题 作者 时间 类型 操作

Multi-resolution texture synthesis from turntable image sequences

Xuedong WANG, Xiaojun WU, Xiaorong ZHANG

期刊论文

Study on micro-texture and skid resistance of aggregate during polishing

Zhenyu QIAN, Lingjian MENG

期刊论文

Multi-objective optimization of surface texture for the slipperswash plate interface in EHA pumps

期刊论文

Effect of steady shear on multi-axial texture of symmetric diblock copolymers

XU Hui, LIU Honglai, HU Ying

期刊论文

The effect of texture and irrigation on the soil moisture vertical-temporal variability in an urban artificial

Xiaofeng ZHANG,Xu ZHANG,Guanghe LI

期刊论文

Application of MoS in the space environment: a review

期刊论文

Laboratory and field evaluation of asphalt pavement surface friction resistance

Zhong WU, Chris ABADIE

期刊论文

Multiple input self-organizing-map ResNet model for optimization of petroleum refinery conversion units

期刊论文

A bacterial artificial chromosome-based physical map of

Yuhua FU,Zhiqiang XIA,Shujuan WANG,Xin CHEN,Cheng LU,Mingcheng LUO,Hongbin ZHANG,Wenquan WANG

期刊论文

自动驾驶地图有关政策的思考和建议

刘经南,董杨,詹骄,高柯夫

期刊论文

用航空航天影像更新地形图地物要素的栅格化方法

林宗坚

期刊论文

基于纹理及小波分析的车牌定位方法

黄卫,路小波,余彦翔,凌小静

期刊论文

Optimization of process parameters for mature landfill leachate pretreatment using MAP precipitation

Wei LI, Xiaowen DING, Min LIU, Yuewen GUO, Lei LIU

期刊论文

腌制工艺对大菱鲆质构及理化性质的影响

王甜甜,李振兴,林洪,郭晓华

期刊论文

Optimization of fuel supply map during starting process of electronic controlled diesel engine

LIANG Jinguang, YU Xiumin, GAO Yue, WANG Yunkai, YU Hongyang, Gong Baoli

期刊论文