In order to compete in the global manufacturing mar ke t, agility is the only possible solution to response to the fragmented market se gments and frequently changed customer requirements. However, manufacturing agil ...In order to compete in the global manufacturing mar ke t, agility is the only possible solution to response to the fragmented market se gments and frequently changed customer requirements. However, manufacturing agil ity can only be attained through the deployment of knowledge. To embed knowledge into a CAD system to form a knowledge intensive CAD (KIC) system is one of way to enhance the design compatibility of a manufacturing company. The most difficu lt phase to develop a KIC system is to capitalize a huge amount of legacy data t o form a knowledge database. In the past, such capitalization process could only be done solely manually or semi-automatic. In this paper, a five step model fo r automatic design knowledge capitalization through the use of data mining is pr oposed whilst details of how to select, verify and performance benchmarking an a ppropriate data mining algorithm for a specific design task will also be discuss ed. A case study concerning the design of a plastic toaster casing was used as an illustration for the proposed methodology and it was found that the avera ge absolute error of the predictions for the most appropriate algorithm is withi n 17%.展开更多
Since it takes a long time to design an aircraft, the succession to or the acquirement of knowledges and technologies is a key to provide to aircraft design high quality and productivity. This paper describes a comput...Since it takes a long time to design an aircraft, the succession to or the acquirement of knowledges and technologies is a key to provide to aircraft design high quality and productivity. This paper describes a computer support system for wing design using a new tool based on an object-oriented approach. The system is programmed in a module of objects which represent design tasks or design knowledges. The modulated program gives advantages to maintain and extend the system easily. The system provides to users a flexible support with excellent user interface which consists of mouse, menu-driven system, and window system.展开更多
Since the founding of New China in 1949, according to the Constitution of the People's Republic of China, the central government has made it a basic state policy to help ethnic minorities-inhabited border areas with ...Since the founding of New China in 1949, according to the Constitution of the People's Republic of China, the central government has made it a basic state policy to help ethnic minorities-inhabited border areas with their political, economic and cultural development, and to lead all the ethnic groups of China onto the road to common prosperity.展开更多
Automated installation of primary roof support material can potentially increase productivity and operator safety in the roadway development process within underground coal mining. Although the broader manufacturing s...Automated installation of primary roof support material can potentially increase productivity and operator safety in the roadway development process within underground coal mining. Although the broader manufacturing sector has benefited from automation, several challenges exist within the Australian underground coal industry which makes it difficult to fully exploit these technologies. At the University of Wollongong a series of reprogrammable electromechanical manipulators have been designed to overcome these challenges and automatically handle the installation of roof and rib containment consumables on a continuous miner. The automated manipulation removes personnel from hazards in the immediate face area, particularly those associated with working in a confined and unstable working environment in close proximity to rotating and moving equipment. In a series of above ground trials the automated system was successfully demonstrated without human intervention and proven to be capable of achieving cycle times at a rate of 10 m per operating hour, consistent with that required to support high capacity longwall mines. The trials also identified a number of refinements which could further improve both cycle times and system reliability when considering the technology for underground use. The results have concluded that conventional manual handling practices on a continuous miner can be eliminated, and that the prototypes have significantly reduced the technical risk in proceeding to a full underground trial.展开更多
Homestay tourism has begun to flourish throughout the country,becoming a model of tourism innovation and upgrading,and attracting increasing amounts of capital.Through the collection and analysis of tourist questionna...Homestay tourism has begun to flourish throughout the country,becoming a model of tourism innovation and upgrading,and attracting increasing amounts of capital.Through the collection and analysis of tourist questionnaire data for key cities in the Yangtze River Delta,and based on the theory of tourists’perceived value,18 factors related to the perception of homestay tourism are examined.Through exploratory factor analysis,three main factors of facilities and environment perception,cultural experience perception and service value perception are extracted.Then,from the perspectives of each of these perceptions,this study determines the degree of support for homestay tourism development in the Yangtze River Delta,obtains the key factors that affect the development of homestay tourism,and constructs a structural equation model of tourist perception and the degree of homestay tourism support.By calculating the regression path of the structural equation,the standardized path coefficients of the facilities and environment perception,cultural experience perception and service value perception are found to be 0.724,0.813 and 0.692,respectively.These three factors have a significant impact on the development of homestay tourism agglomeration.Positive facilities and environmental perception can effectively support the development of homestay tourism,while the cultural experience perception provides its basic condition,and the service value perception constitutes an important factor of homestay tourism development.To better guide the development of homestay tourism,attention must be paid to developing the tourism facilities and environment,to cultivating tourism cultural experiences,and to improving of tourism service value.展开更多
On August 20, 2009, the State Council adopted the Guidelines on Maintaining the Steady and Relatively Fast Economic Development of Western Regions in Coping With the International Financial Crisis (the Guidelines).
The Qingcheng oilfield,the largest shale oil field in China,was discovered in 2019 in source rock of Chang 7 Member of Mesozoic Yanchang Formation,Changqing Oilfield in Ordos Basin,with newly increased proven geologic...The Qingcheng oilfield,the largest shale oil field in China,was discovered in 2019 in source rock of Chang 7 Member of Mesozoic Yanchang Formation,Changqing Oilfield in Ordos Basin,with newly increased proven geological reserves of 358 million tons,predicted geological reserves of 693 million tons,and a total of 1.051 billion tons of shale oil resources.This achieves a historic breakthrough in exploration of shale oil in Chang 7 Member.In recent years,focusing on key issues,such as whether there develop sweet spots in source rock,whether commercial oil production capacity can be formed,and whether scale-effective development can be achieved,studies about geological conditions for shale oil accumulation have been continuously carried out,key supporting technologies have been developed,and a series of theoretical innovations and technological breakthroughs have been achieved in oil exploration in source rocks.The results indicate that shale oil accumulation in Chang 7 Member is controlled by following factors.Firstly,lacustrine black shale,dark mudstone and other high-quality source rocks lay a material foundation for shale oil formation.Secondly,sandy deposits intercalated within black shale and dark mudstones are exploration sweet spots,and sandbody combination types are controlled by morphology of bottom of the lacustrine basin.Thirdly,reservoir properties are good due to development of micro-nano pore throats.Finally,reservoirs with high oil saturation and high gas-oil ratio are formed due to high-intensity oil charging in source rock.Effective matching of multiple factors is a key for shale oil accumulation in Chang 7 Member in Ordos Basin.Through innovation of key supporting technologies,exploration and development technologies for shale oil are developed,and substantial breakthrough on exploration and development of shale oil is realized.The first application of logging-seismic combination technology in loess plateau improves significantly quality of 3D seismic data,which effectively guides prediction of sandy sweet spots.Three-quality well logging technology is used for further evaluation of geological and engineering sweet spots of shale oil.With volumetric fracturing technology based on precise segmentation of long horizontal wells,initial daily oil production of individual well is increased from previously 10 tons to more than 18 tons.The exploration breakthrough in source rocks in Chang 7 Member in Qingcheng oilfield provides an important resource base for the second accelerated development of Changqing Oilfield.It is predicated that oil production from shale in Chang 7 Member in Qingcheng oilfield will reach three million tons in 2022 and five million tons in 2025.展开更多
文摘In order to compete in the global manufacturing mar ke t, agility is the only possible solution to response to the fragmented market se gments and frequently changed customer requirements. However, manufacturing agil ity can only be attained through the deployment of knowledge. To embed knowledge into a CAD system to form a knowledge intensive CAD (KIC) system is one of way to enhance the design compatibility of a manufacturing company. The most difficu lt phase to develop a KIC system is to capitalize a huge amount of legacy data t o form a knowledge database. In the past, such capitalization process could only be done solely manually or semi-automatic. In this paper, a five step model fo r automatic design knowledge capitalization through the use of data mining is pr oposed whilst details of how to select, verify and performance benchmarking an a ppropriate data mining algorithm for a specific design task will also be discuss ed. A case study concerning the design of a plastic toaster casing was used as an illustration for the proposed methodology and it was found that the avera ge absolute error of the predictions for the most appropriate algorithm is withi n 17%.
文摘Since it takes a long time to design an aircraft, the succession to or the acquirement of knowledges and technologies is a key to provide to aircraft design high quality and productivity. This paper describes a computer support system for wing design using a new tool based on an object-oriented approach. The system is programmed in a module of objects which represent design tasks or design knowledges. The modulated program gives advantages to maintain and extend the system easily. The system provides to users a flexible support with excellent user interface which consists of mouse, menu-driven system, and window system.
文摘Since the founding of New China in 1949, according to the Constitution of the People's Republic of China, the central government has made it a basic state policy to help ethnic minorities-inhabited border areas with their political, economic and cultural development, and to lead all the ethnic groups of China onto the road to common prosperity.
基金the Australian Coal Association Research Programthe Roadway Development Task Group for their ongoing support with funding and review
文摘Automated installation of primary roof support material can potentially increase productivity and operator safety in the roadway development process within underground coal mining. Although the broader manufacturing sector has benefited from automation, several challenges exist within the Australian underground coal industry which makes it difficult to fully exploit these technologies. At the University of Wollongong a series of reprogrammable electromechanical manipulators have been designed to overcome these challenges and automatically handle the installation of roof and rib containment consumables on a continuous miner. The automated manipulation removes personnel from hazards in the immediate face area, particularly those associated with working in a confined and unstable working environment in close proximity to rotating and moving equipment. In a series of above ground trials the automated system was successfully demonstrated without human intervention and proven to be capable of achieving cycle times at a rate of 10 m per operating hour, consistent with that required to support high capacity longwall mines. The trials also identified a number of refinements which could further improve both cycle times and system reliability when considering the technology for underground use. The results have concluded that conventional manual handling practices on a continuous miner can be eliminated, and that the prototypes have significantly reduced the technical risk in proceeding to a full underground trial.
基金The Youth Program of National Natural Science Foundation of China(41801139)The China Innovation Funding(2019YFC0507802)。
文摘Homestay tourism has begun to flourish throughout the country,becoming a model of tourism innovation and upgrading,and attracting increasing amounts of capital.Through the collection and analysis of tourist questionnaire data for key cities in the Yangtze River Delta,and based on the theory of tourists’perceived value,18 factors related to the perception of homestay tourism are examined.Through exploratory factor analysis,three main factors of facilities and environment perception,cultural experience perception and service value perception are extracted.Then,from the perspectives of each of these perceptions,this study determines the degree of support for homestay tourism development in the Yangtze River Delta,obtains the key factors that affect the development of homestay tourism,and constructs a structural equation model of tourist perception and the degree of homestay tourism support.By calculating the regression path of the structural equation,the standardized path coefficients of the facilities and environment perception,cultural experience perception and service value perception are found to be 0.724,0.813 and 0.692,respectively.These three factors have a significant impact on the development of homestay tourism agglomeration.Positive facilities and environmental perception can effectively support the development of homestay tourism,while the cultural experience perception provides its basic condition,and the service value perception constitutes an important factor of homestay tourism development.To better guide the development of homestay tourism,attention must be paid to developing the tourism facilities and environment,to cultivating tourism cultural experiences,and to improving of tourism service value.
文摘On August 20, 2009, the State Council adopted the Guidelines on Maintaining the Steady and Relatively Fast Economic Development of Western Regions in Coping With the International Financial Crisis (the Guidelines).
基金supported by the National Research Council of Science and Technology Major Project of China(No.2016ZX05050,No.2017ZX05001002)National Key Basic Research Project of China(973 Program)(No.2014CB239003).
文摘The Qingcheng oilfield,the largest shale oil field in China,was discovered in 2019 in source rock of Chang 7 Member of Mesozoic Yanchang Formation,Changqing Oilfield in Ordos Basin,with newly increased proven geological reserves of 358 million tons,predicted geological reserves of 693 million tons,and a total of 1.051 billion tons of shale oil resources.This achieves a historic breakthrough in exploration of shale oil in Chang 7 Member.In recent years,focusing on key issues,such as whether there develop sweet spots in source rock,whether commercial oil production capacity can be formed,and whether scale-effective development can be achieved,studies about geological conditions for shale oil accumulation have been continuously carried out,key supporting technologies have been developed,and a series of theoretical innovations and technological breakthroughs have been achieved in oil exploration in source rocks.The results indicate that shale oil accumulation in Chang 7 Member is controlled by following factors.Firstly,lacustrine black shale,dark mudstone and other high-quality source rocks lay a material foundation for shale oil formation.Secondly,sandy deposits intercalated within black shale and dark mudstones are exploration sweet spots,and sandbody combination types are controlled by morphology of bottom of the lacustrine basin.Thirdly,reservoir properties are good due to development of micro-nano pore throats.Finally,reservoirs with high oil saturation and high gas-oil ratio are formed due to high-intensity oil charging in source rock.Effective matching of multiple factors is a key for shale oil accumulation in Chang 7 Member in Ordos Basin.Through innovation of key supporting technologies,exploration and development technologies for shale oil are developed,and substantial breakthrough on exploration and development of shale oil is realized.The first application of logging-seismic combination technology in loess plateau improves significantly quality of 3D seismic data,which effectively guides prediction of sandy sweet spots.Three-quality well logging technology is used for further evaluation of geological and engineering sweet spots of shale oil.With volumetric fracturing technology based on precise segmentation of long horizontal wells,initial daily oil production of individual well is increased from previously 10 tons to more than 18 tons.The exploration breakthrough in source rocks in Chang 7 Member in Qingcheng oilfield provides an important resource base for the second accelerated development of Changqing Oilfield.It is predicated that oil production from shale in Chang 7 Member in Qingcheng oilfield will reach three million tons in 2022 and five million tons in 2025.