Engineering

Review | 2020-08-03

Progress of Air Pollution Control in China and Its Challenges and Opportunities in the Ecological Civilization Era

China's past economic growth has substantially relied on fossil fuels, causing serious air pollution issues. Decoupling economic growth and pollution has become the focus in developing ecological civilization in China. We have analyzed the three-decade progress of air pollution controls in China, highlighting a strategic transformation from emission control toward air quality management. Emission control of sulfur dioxide (SO₂) resolved the deteriorating acid rain issue in China in 2007. Since 2013, control actions on multiple precursors and sectors have targeted the reduction of the concentration of fine particulate matter (PM_2.5), marking a transition to an air-quality-oriented strategy. Increasing ozone (O₃) pollution further requires O₃ and PM_2.5 integrated control strategies with an emphasis on their complex photochemical interactions. Fundamental improvement of air quality in China, as a key indicator for the success of ecological civilization construction, demands the deep de-carbonization of China's energy system as well as more synergistic pathways to address air pollution and global climate change simultaneously.

Xi Lu , Shaojun Zhang et al.

Article | 2020-07-30

Velocity-Free MS/AE Source Location Method for Three-Dimensional Hole-Containing Structures

Microseismic source/acoustic emission (MS/AE) localization method is crucial for predicting and controlling of potentially dangerous sources of complex structures. However, the locating errors induced by both the irregular structure and pre-measured velocity are poorly understood in existing methods. To meet the high-accuracy locating requirements in complex three-dimensional hole-containing structures, a velocity-free MS/AE source location method is developed in this paper. It avoids manual repetitive training by using equidistant grid points to search the path, which introduces A* search algorithm and uses grid points to accommodate complex structures with irregular holes. It also takes advantage of the velocity-free source location method. To verify the validity of the proposed method, lead-breaking tests were performed on a cubic concrete test specimen with a size of 10 cm × 10 cm × 10 cm. It was cut out into a cylindrical empty space with a size of ϕ6cm × 10 cm. Based on the arrivals, the classical Geiger method and the proposed method are used to locate lead-breaking sources. Results show that the locating error of the proposed method is 1.20 cm, which is less than 2.02 cm of the Geiger method. Hence, the proposed method can effectively locate sources in the complex three-dimensional structure with holes and achieve higher precision requirements.

Longjun Dong , Qingchun Hu et al.

Article | 2020-07-30

Developing Medical Examiner Offices in China: Necessity and Administration Mode

Deepening the reform of the judicial system in China and improving the unified management system for judicial authentication are important in promoting the overall law-based governance of the country. Straightening out the management system of forensic identification is the top priority to establish a unified management system for judicial authentication. In this paper, different management systems of forensic identification are compared and the current disadvantages in forensic identification in China are analyzed, including decentralized management departments, excessive marketization, unbalanced regional development, and insufficient research investment. Based on this, the feasibility and necessity of establishing an administration mode of medical examiner offices in China are investigated. Moreover, the operating mechanism and responsibilities of the medical examiner offices are elaborated. We propose that China should integrate its forensic resources in different departments and strengthen the forensic professionals to establish a unified medical examiner office system which is independent of the judicial system and covers the national, provincial, and municipal levels, thus to improve the authority and credibility of forensic identification. The medical examiner offices should be responsible for judicial authentication, scientific research, professional title assessment, personnel training, and for formulating technical standards and guidelines for forensic identification.

Song Suimin , Ma Chunling et al.

Article | 2020-07-30

Constructing Internet Plus New Infrastructure in Cities

Internet Plus New Infrastructure is a key component of the Internet Plus initiative. This study analyzes the demand,development status, and problems regarding the Internet Plus New Infrastructure mode, and proposes that establishing the Internet Plus New Infrastructure mode requires addressing the effective aggregation, integration, and application of massive data and ensuring realtime processing and response with high concurrency, low latency, and high security and reliability of network services. This study also demonstrates the typical construction path for constructing the Internet Plus New Infrastructure mode, that is, to address the efficient integration and effective use of city data through the construction of data middle offices and to provide both high-throughput and high quality services through the “information high-speed rail stations.” The concepts and technical essentials of the data middle offices and information high-speed rail stations are analyzed, which are the core infrastructures of the Internet Plus initiative. To promote the Internet Plus initiative in China, countermeasures and suggestions for the construction of the Internet Plus New Infrastructure mode in cities are proposed from the perspective of planning, policy implementation, and flexible operating models.

Fan Lingjun , Yang Fei et al.

Article | 2020-07-30

A Product Process Adaptive Design Method Based on Manufacturing-Related Big Data

As digital and smart production methods being applied widely in manufacturing, enterprises should pay more attention to the values of manufacturing-related big data, which is important to the innovation of product process design. This study aims to propose a product process adaptive design method based on manufacturing-related big data. This method is proposed based on the requirement of enterprises for data–business deep integration and it is used for solving the insufficient utilization of manufacturing-related data among enterprises. To this end, a product process adaptive design model “data + knowledge + decision” is proposed and the data mining and utilization processes are summarized for the model, namely, multi-source heterogeneous data fusion; data cleaning and preprocessing; data conversion and dimensionality reduction; data mining; data visualization; and design decision. Subsequently, the automobile welding process is used as an example. A prediction model of the relationship between welding parameters and welding defects is established, aiming to improve welding quality and realize welding process adaptive design. This research reveals that manufacturing related big data contains rich knowledge and patterns and thus can guide product design decisions and support the product process adaptive design under different manufacturing environments. In the future, to enhance the integration of manufacturing-related big data with product process design, the integration of big data with 5G technology should be promoted and investment should be increased inthe development of big data and algorithm design platforms.

Wei Wei , Chen Zheng et al.

Article | 2020-07-30

The Architecture of a Product Collaborative Design Platform Based on Cloud Manufacturing

Product design is crucial to improving product quality and lowering manufacturing costs. Cloud manufacturing is emerging as a new manufacturing model and an integrated technology and has become an important development direction for advanced manufacturing. To adapt to the transformation of traditional manufacturing to service-oriented and innovative manufacturing, this study investigates the current status of collaborative design and summarizes the problems regarding the sharing and on-demand use of massive resources in traditional manufacturing. It also proposes the architecture of a product collaborative design platform based on cloud manufacturing and explains the meaning of each layer in detail. Then three key technologies for building the platform are discussed: cloud manufacturing technology, product family and product platform technology, and product collaborative design technology. Finally, using a cloud-manufacturing-based product collaborative design platform system established by a company as an example, the system architecture and functions of the platform are analyzed, and the differences in task assign and completion time between cloud manufacturing and traditional manufacturing are compared. The effectiveness and superiority of the cloud manufacturing-based system are verified, and the application and research direction of the system are prospected.

Wei Wei , Wang Yufei et al.

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