Photogrammetry-based method is gaining popularity in many fields. One of the main tasks of photogrammetry is to identify the homologous points in multiple images, which is commonly referred to as the corresponding problem. Coded targets are often placed on the surfaces of the targeted objects and have been widely used as a reliable method for solving the corresponding problem in photogrammetry for high-accuracy three-dimensional measurements. Automated recognition and identification of coded targets are of great importance in the coded target-based photogrammetry. However, false coded target identifications are inevitable due to large perspective distortion, unfavorable lighting conditions, and low-resolution, low-quality images, etc. As a result, manual corrections are often required, which are tedious, prone to error, and inefficient. In this paper, a faster R-CNN-based method has been proposed to recognize coded targets. Then, a table method has been developed to automatically identify and reject the falsely identified coded targets by taking advantages of the prior knowledge of the geometric arrangement of the coded targets. Based on that, missing coded targets can be recovered using either interpolation or extrapolation method. The effectiveness and accuracy of the proposed method are validated by implementing it into three-dimensional reconstruction of soil specimens during triaxial testing in geotechnical engineering. Experimental validation results indicate that the proposed method can achieve accurate and efficient coded target recognition and identification.
相似文献In this article, we used a non-radial DEA under natural and managerial disposability to measure the unified efficiency of 30 administrative regions in China and then evaluated their operational and environmental performances. We proposed the performance progress unified index (PPUI) based on the non-radial DEA methodology in a time horizon under natural and managerial disposability with a crossover to measure the performance variety of DMUs. The results of the unified efficiency measured under natural and managerial disposability showed that both operational and environmental performance in eastern China were the highest among the three regions during 2000–2011. The PPUIs under natural and managerial disposability indicated that the operational and environmental performance of the three regions improved during 2000–2011, and the rate of operational and environmental performance of eastern China was higher than the other two regions.
相似文献Based on an input–output model, this paper calculates carbon emissions from household energy consumption in 2002, 2005, 2007, and 2010 between China and the USA. By a comparative analysis of the two countries, the results indicate the following: (1) In terms of the total household indirect carbon emissions, the USA has always been at a higher level than China. However, in recent years, China has presented a rapidly rising trend. In contrast, the USA appears to be experiencing a downward trend. (2) Indirect carbon emissions from USA household consumption mainly focus on Residence; Education, Culture, and Recreation; and Transport and Communications. By comparison, residence accounts for 50 % of China’s household indirect carbon emissions, and seven other sectors are much less than the USA (3) Although the number of China’s household facilities is growing rapidly, the carbon emissions remain at a relatively steady level. (4) In terms of the absolute value of the indirect carbon emissions from housing, the USA maintains a steady 400 million ton, while China increased from 150 to 500 million ton over 2002–2010.
相似文献In China, carbon capture and storage (CCS) is recognized as one of the most promising technologies through which to achieve a large reduction in CO2 emissions in future. The choice among different CCS technologies is critical for large-scale applications. With the aim of developing instructive policy suggestions for CCS development, this study proposed an interval programming model to select the optimal CCS technology among the different CCS technologies available in China. The analysis results indicate that the selection of CO2 capture technologies should be based on the actual situation of the project and industry being targeted. If the government implements mandatory CO2 emission reductions, storage in deep saline aquifers is the optimal choice for CO2 sequestration when oil prices are low and the number of available CO2 emission permits is large. In contrast, enhanced oil recovery is the optimal choice when oil prices increase and the availability of CO2 emission permits decreases. It is critical that the government reduce the operating cost and the cost of CO2 capture in particular.
相似文献Carbon verification, which can guarantee the reliability and credibility of greenhouse gas (GHG) emission data, is the most important part of the daily operations of the carbon emission right trading system. Many international institutions, countries and regions have conducted research on and have practiced carbon verification policies and systems. Through comparative analysis of the international carbon verification policies and systems, they can provide experience for Chinese unified national carbon market to start supporting carbon verification. The paper study concludes that (1) carbon verification systems developed by international institutions focus on the scientific level of verification methods; (2) carbon verification policies and systems issued by important countries and regions draw on International Standardization Organization (ISO)14064 standards based on their national conditions and focus on the scientific level and reasonableness of verification methods; (3) major international experience includes complete verification policies and systems, strict standard verification procedures, diversified verification forms and a focus on key emission sources. Based on the differences in China’s carbon emissions characteristics caused by unbalanced regional economic development and the conditions of carbon verification in seven pilot carbon trading areas, this thesis proposes the following suggestions: pushing forward the establishment of carbon verification policies and systems by accelerating legislation on climate changes; facilitating carbon verification in a coordinated manner; regulating key GHG emission sources; establishing and improving supervision on carbon verification; and intensifying international exchanges and cooperation.
相似文献X-ray computed tomography (CT) has emerged as the most prevalent technique to obtain three-dimensional morphological information of granular geomaterials. A key challenge in using the X-ray CT technique is to faithfully reconstruct particle morphology based on the discretized pixel information of CT images. In this work, a novel framework based on the machine learning technique and the level set method is proposed to segment CT images and reconstruct particles of granular geomaterials. Within this framework, a feature-based machine learning technique termed Trainable Weka Segmentation is utilized for CT image segmentation, i.e., to classify material phases and to segregate particles in contact. This is a fundamentally different approach in that it predicts segmentation results based on a trained classifier model that implicitly includes image features and regression functions. Subsequently, an edge-based level set method is applied to approach an accurate characterization of the particle shape. The proposed framework is applied to reconstruct three-dimensional realistic particle shapes of the Mojave Mars Simulant. Quantitative accuracy analysis shows that the proposed framework exhibits superior performance over the conventional watershed-based method in terms of both the pixel-based classification accuracy and the particle-based segmentation accuracy. Using the reconstructed realistic particles, the particle-size distribution is obtained and validated against experiment sieve analysis. Quantitative morphology analysis is also performed, showing promising potentials of the proposed framework in characterizing granular geomaterials.
相似文献Filters managed in zoned dams are designed according to criteria based on the grain size distribution of both filter and eroded soil. However, the constriction size distribution of the filter is the key parameter which governs the filter retention process of flowing eroded particles. To assess the filter efficiency regarding eroded particles, several filters and base soils are tested in a vertical cell with a configuration coupling erosion and filtration processes. For setting the boundary condition of eroded particles at the filter inlet, hole erosion test (HET) was performed on the base soil. The investigation of the evolution of filter behavior shows that the void ratio and the grain shape are of a great influence on filter efficiency. A new approach of filter clogging was proposed by evaluating a damage index which is affected by various parameters such as the ratio D15/d85 and the size of eroded particles. An approach linking the geometrical parameters (damage index) to the hydraulic conductivity leads to an estimation of the filter performance which provides a more quantifiable and realistic criterion. The results indicate that even existing criteria were not met; the tested filters remain efficient as regards to experimental data. An analytical approach based on constrictions size distribution was used and pore reduction was matched with experimental results.
相似文献China is preparing to develop and implement an emissions trading system in its 13th five-year plan. Allowance allocation is one of the key issues to settle during the establishment of this system. This study applies the China Energy and Environmental Policy Analysis model to assess how the allowances should be allocated. Simulation results show that, while impacts on China’s economic development vary according to how allowances are allocated, the negative impacts cannot be mitigated completely, which are between −0.5 and −0.1 % when 5 % of carbon emissions are reduced. In terms of the impacts on the macroeconomy, sectoral output, and capital revenue, results suggest that auctioning the allowances and recycling the revenue to reduce the indirect tax will perform best in alleviating the negative impacts. Meanwhile, impacts of carbon mitigation on international competitiveness can be reduced most in the approach where only key energy- and trade-intensive sectors are able to receive free allowances. However, if citizens’ welfare and quality of life is prioritized, auctioning the allowance and transferring the revenue to households in proportion to their occupation will be the most effective approach; in this case, the negative impacts on rural households’ disposable incomes and welfare will be reduced, and the income gap between rural and urban households will be narrowed.
相似文献As natural and man-made disasters have been increasing, interest in preventing crises and/or mitigating the associated consequences has been growing as well. When dealing with predictable disasters, there is a limited time for effective response, and people should be evacuated in a short time to minimize the fatalities. In such extraordinary situations, attention should be given to making better use of existing infrastructure. The aim of this study is to present a model for optimizing street directions in order to increase the outbound capacity of the network. However, because of the magnitude of the problem, an optimal solution cannot be reached through ordinary methods. Hence, the simulated annealing algorithm, which is a meta-heuristic technique, is used. Computational results on a case study demonstrate that this technique yields considerable improvement in the objective function of the problem which is total travel time of road network users.
相似文献This paper calculated the embodied carbon in China export and its distribution in each industrial sector. The calculation results showed the total carbon emission of export experienced an increase before 2007 and then a decrease till 2010. The ratio of export embodied carbon accounting for the total carbon emission in China also increased from 31 % in 2002 to 52 % in 2007 and then declined to 40 % in 2010. As for distribution, the export embodied carbon emission of the following industries such as machinery and equipment manufacturing, metal products manufacturing industry, chemical industry, textile, clothing and leather products manufacturing industry ranked the highest. According to the calculation and analysis of the main driving factors of embodied carbon growth, we analyzed the structure effect, scale effect and technological effect’s influence on embodied carbon growth, respectively. We also calculated the trade competitiveness index of 17 export industries. Through research, we found that the products with strong international competitiveness belong to high-carbon-emission categories, which was the main reason of high carbon emission in China export. Finally, we proposed related policy suggestions to promote China’s export trade structural readjustment and optimization and China’s low carbon development in export.
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