unified coordinate system
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2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Yahui Xiao

The rendering effect of known visual image texture is poor and the output image is not always clear. To solve this problem, this paper proposes a visual image rendering based on scene visual understanding algorithm. In this approach, the color segmentation of known visual scene is carried out according to a predefined threshold, and the segmented image is processed by morphology. For this purpose, the extraction rules are formulated to screen the candidate regions. The color image is fused and filtered in the neighborhood, the pixels of the image are extracted, and the 2D texture recognition is realized by multilevel fusion and visual feature reconstruction. Using compact sampling to extract more target features, feature points are matched, the coordinate system of known image information are integrated into a unified coordinate system, and design images are generated to complete art-aided design. Simulation results show that the proposed method is more accurate than the original method for extracting the information of known images, which helps to solve the problem of clearly visible output images and improves the overall design effect.


Author(s):  
Ying Zhang ◽  
Daiyin Zhu ◽  
Yulei Qian ◽  
Yuan Cheng ◽  
Xinhua Mao ◽  
...  

2019 ◽  
Vol 13 (11) ◽  
pp. 2835-2851 ◽  
Author(s):  
Jozef Šupinský ◽  
Ján Kaňuk ◽  
Zdenko Hochmuth ◽  
Michal Gallay

Abstract. Ice caves can be considered an indicator of the long-term changes in the landscape. Ice volume is dynamic in the caves throughout the year, but the inter-seasonal comparison of ice dynamics might indicate change in the hydrological–climatic regime of the landscape. However, evaluating cave ice volume changes is a challenging task that requires continuous monitoring based on detailed mapping. Today, laser scanning technology is used for cryomorphology mapping to record the status of the ice with ultra-high resolution. Point clouds from individual scanning campaigns need to be localised in a unified coordinate system as a time series to evaluate the dynamics of cave ice. Here we present a selective cloud-to-cloud approach that addresses the issue of registration of single-scan missions into the unified coordinate system. We present the results of monitoring ice dynamics in the Silická ľadnica cave situated in Slovak Karst, which started in summer of 2016. The results show that the change of ice volume during the year is continuous and we can observe repeated processes of degradation and ice formation in the cave. The presented analysis of the inter-seasonal dynamics of the ice volume demonstrates that there has been a significant decrement of ice in the monitored period. However, further long-term observations are necessary to clarify the mechanisms behind this change.


2019 ◽  
Author(s):  
Jozef Šupinský ◽  
Ján Kaňuk ◽  
Zdenko Hochmuth ◽  
Michal Gallay

Abstract. Ice caves can be considered as an indicator of the long-term changes in the landscape. Dynamics in ice volume in the caves are common throughout the year, but the inter-seasonal comparison of ice dynamics indicates a change in the hydrological-climatic regime of the landscape. However, evaluating cave ice volume changes is a challenging task that requires continuous monitoring based on detailed mapping. Nowadays, laser scanning technology is used for cryomorphology mapping to record a status of the ice at an ultra-high resolution. In order to evaluate the dynamics of cave ice, it is necessary to place individual measurements in an unified coordinate system. In the presented paper, we propose a selective cloud-to-cloud approach that addresses the issue of registration of single scan missions into unified coordinate system. We present the results of the ice dynamics monitoring in the Silická ľadnica cave situated in the Slovak Karst, which started in summer of 2016. Based on the results we can conclude that the change in ice volume during the year is continuous and we can observe repeated processes of degradation and ice formation in the cave. Presented analysis of the inter-seasonal dynamics of the ice volume demonstrates that there has been a significant decrement of ice in the monitored period.


Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1701 ◽  
Author(s):  
Wensheng Chang ◽  
Haihong Tao ◽  
Guangcai Sun ◽  
Yuqi Wang ◽  
Zheng Bao

Considering the difficulty of pulse repetition frequency (PRF) design in multi-angle SAR when using ultra-high speed platforms, a multi-angle SAR imaging system in a unified coordinate system is proposed. The digital multi-beamforming is used in the system and multi-angle SAR data can be obtained in one flight. Therefore, the system improves the efficiency of data recording. An improved range migration algorithm (RMA) is used for data processing, and imaging is made in a unified imaging coordinate system. The resolution of different view images is the same, and there is a fixed delay between the images. On this basis, the SAR image fusion is performed after image matching. The results of simulation and measured data confirm the effectiveness of the system and the method.


2018 ◽  
Vol 70 (4) ◽  
pp. 782-788
Author(s):  
Aibin Zhu ◽  
Hongling Wu ◽  
Yulei Yang ◽  
Shengli He

Purpose Because of the various geometric descriptions of different bearing types, performance calculation of journal bearing is complicated, and is difficult in traditional model. This paper aims to simplify the calculation of the journal bearing performance, and to reduce the workload. Design/methodology/approach On the basis of previous research, a general performance calculation model of journal bearing is proposed in this paper. Eccentricity ratio and attitude angle of axis to each pad are calculated by coordinates of spindle center and each pad center by establishing the unified coordinate system. The surface deformation of journal bearing is taken into consideration, and a correction value is added to the dimensionless oil film thickness. Findings The performance calculation results of various fix-pad and tilting-pad journal bearings match the results of the existing references very well, revealing the validity of the model. The general model can greatly reduce programming workload, and increase adaptability to different bearings. Originality/value Geometric descriptions of both fix-pad and tilting-pad journal bearings are unified in this model, which can be applied to both standard and non-standard journal bearings with different preload ratios. In addition, due to the unification of different bearings types, this model is more conducive to performance comparison among different bearing types, and promotes the development of new structural forms for journal bearings.


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