CSPN++: Learning Context and Resource Aware Convolutional Spatial Propagation Networks for Depth Completion

Depth Completion deals with the problem of converting a sparse depth map to a dense one, given the corresponding color image. Convolutional spatial propagation network (CSPN) is one of the state-of-the-art (SoTA) methods of depth completion, which recovers structural details of the scene. In this paper, we propose CSPN++, which further improves its effectiveness and efficiency by learning adaptive convolutional kernel sizes and the number of iterations for the propagation, thus the context and computational resources needed at each pixel could be dynamically assigned upon requests. Specifically, we formulate the learning of the two hyper-parameters as an architecture selection problem where various configurations of kernel sizes and numbers of iterations are first defined, and then a set of soft weighting parameters are trained to either properly assemble or select from the pre-defined configurations at each pixel. In our experiments, we find weighted assembling can lead to significant accuracy improvements, which we referred to as "context-aware CSPN", while weighted selection, "resource-aware CSPN" can reduce the computational resource significantly with similar or better accuracy. Besides, the resource needed for CSPN++ can be adjusted w.r.t. the computational budget automatically. Finally, to avoid the side effects of noise or inaccurate sparse depths, we embed a gated network inside CSPN++, which further improves the performance. We demonstrate the effectiveness of CSPN++on the KITTI depth completion benchmark, where it significantly improves over CSPN and other SoTA methods.Comment: Camera Ready Version. Accepted by AAAI 202

Analysis on solid waste emission and management in the development of Beijing City

Beijing, as a typical large city of China, is experiencing a transformational development that huge change occurs in the industrial structure and the city infrastructure. It will have an impact on the resources consumption and solid waste management of Beijing. Based on the data of city development and resources utilization in 2010-2014, this research analyzes the relationship among the different solid waste types, resources consumption and industry development on the premise of sustainable industrial structure adjustment by the methods of the material flow analysis and scenarios analysis. The results show that: firstly, Beijing city has become a typical city relying on resources consumption, with a slow growth of the waste solid emission. Secondly, construction and demolition waste has become the major solid waste in total amount, while municipal solid waste is still the major solid waste in the central urban. Thirdly, a larger reduction of solid waste landfill would be obtained by adjusting the mode of resources recycle, utilization and disposition. The potential reduction of solid waste landfill is estimated to be above 10 million tons in 2020. References [1] Jinglan Hong, Xiangzhi Li, Cui Zhaojie. Life cycle assessment of four municipal solid waste management scenarios in China [J]. Waste Management, 2010, 30: 2362-2369. [2] Dong QingZhang, Soon Keat Tan, Richard M.Gersberg. Municipal solid waste management in China: Status, problems and challenges [J]. Journal of Environmental Management, 2010, 91: 1623-1633. [3] Yan Zhao, Thomas H. Christensen, Wenjing L, et al. Environmental impact assessment of solid waste management in Beijing City, China [J]. Waste Management, 2011, 31: 793-799. [4] Lilliana Abarca Guerrero, Ger Maas, William Hogland. Solid waste management challenges for cities in developing countries [J]. Waste Management, 2013, 33: 220-231

Study on an eco‐design method of industrial solid waste reused products: a case study of mullite produced from fly ash

With the increasing growth of solid waste used as raw materials, it is essential to focus on eco-design of the solid waste reused products to reduce environmental impacts and ensure safe use. In this research, an eco-design and evaluation method is established for the industrial solid waste reused products, with the characteristic of the reuse technology and process of industrial solid waste. This method is established based on the existing eco-design method for general products and life cycle assessment, considering the quality problems as well as the environmental risks in heavy metal, remaining acid and alkali and so on in the recycling products. This method is employed in the fly ash reuse process of producing mullite products. The process is optimized and evaluated by the method with the steps of raw material applicability analysis, process control, products application and safety analysis of final disposition. The results indicate that the process design basically accords with the eco-design purpose of industrial solid waste reused products and it is feasible to implement. References [1] M. Ahmaruzzaman. A review on the utilization of fly ash [J]. Progress in Energy and Combustion Science, 2010, 36: 327-363. [2] Jesus Barragan Ferrer, Stéphane Negny, Guillermo Cortes Robles, Jean Marc Le Lann. Eco-innovative design method for process engineering [J]. Computers and Chemical Engineering, 2012, 45: 137-151. [3] E. Sobiecka. Investigating the chemical stabilization of hazardous waste material (fly ash) encapsulated in Portland cement [J]. International journal of Environmental Science and Technology, 2013, 10: 1219-1224. [4] James W. Levis, Morton A. Barlaz, Joseph F. DeCarolis, S. Ranji Ranjithan. A generalized multistage optimization modeling framework for life cycle assessment-based integrated solid waste management [J]. Environmental Modelling & Software, 2013, 50: 51-65