The 3D numerical simulation model of deep hard-rock deposit in Kaiyang Phosphate Mine of Guiyang was established based on the practical engineering using 3DEC numerical simulation software. The distribution characteri...The 3D numerical simulation model of deep hard-rock deposit in Kaiyang Phosphate Mine of Guiyang was established based on the practical engineering using 3DEC numerical simulation software. The distribution characteristics of displacement fields and plastic zones of the orebody were simulated in three different excavation cases, including the case of excavation artificial inducted roadway in the orebody, the case of horizontal or vertical excavation direction and the case of the upward or downward excavation order. The simulation results indicate that the plastic zone and displacement field of surrounding rock around the inducted roadway are continuously increasing with the increase of the exposure time after digging an artificial inducted roadway in the orebody. Thus the raw rock ore becomes easier to be fragmented, which provides advantageous conditions for roadheader to cut high stress hard-rock. It is worthy noting that there is a large difference in effective utilization of deep ground pressure between horizontal and vertical excavation directions. The later can produce larger deformation and fracture zone than the former on the rock mass around the deduced roadway, which means that the later may utilize the high ground pressure more effectively to break hard-rock. And the obtained results also show that upward excavation order is more helpful for ground pressure to break rock than downward excavation order.展开更多
Association rule mining methods, as a set of important data mining tools, could be used for mining spatial association rules of spatial data. However, applications of these methods are limited for mining results conta...Association rule mining methods, as a set of important data mining tools, could be used for mining spatial association rules of spatial data. However, applications of these methods are limited for mining results containing large number of redundant rules. In this paper, a new method named Geo-Filtered Association Rules Mining(GFARM) is proposed to effectively eliminate the redundant rules. An application of GFARM is performed as a case study in which association rules are discovered between building land distribution and potential driving factors in Wuhan, China from 1995 to 2015. Ten sets of regular sampling grids with different sizes are used for detecting the influence of multi-scales on GFARM. Results show that the proposed method can filter 50%–70% of redundant rules. GFARM is also successful in discovering spatial association pattern between building land distribution and driving factors.展开更多
A numerical wave load model based on two-phase(water-air) Reynolds-Averaged Navier Stokes(RANS) type equations is used to evaluate hydrodynamic forces exerted on flatted-bottom seafloor mining tool during its entering...A numerical wave load model based on two-phase(water-air) Reynolds-Averaged Navier Stokes(RANS) type equations is used to evaluate hydrodynamic forces exerted on flatted-bottom seafloor mining tool during its entering ocean waves of deploying process.The discretization of the RANS equations is achieved by a finite volume approach(FV).The volume of fluid method(VOF) is employed to track the complicated free surface.A numerical wave tank is built to generate the ocean waves which are suitable for deploying seafloor mining tool.A typical deploying condition is employed to reflect the process of flatted-bottom body impacting with waves,and the pressure distribution of bottom is also presented.Four different lowering velocities are applied to obtain the time histories of maximum pressure of bottom,and it can be concluded that the pressure coefficient decreases with water velocity increasing,which is similar with ordinary water entry case.The numerical results clearly demonstrate the characteristics of flatted-bottom body entering ocean waves.展开更多
A test rig for constant velocity water entry experiments was developed that drives a flatted-bottom section attached on six degree of freedom(6-DOF) platform to enter the water vertically at near constant velocity.The...A test rig for constant velocity water entry experiments was developed that drives a flatted-bottom section attached on six degree of freedom(6-DOF) platform to enter the water vertically at near constant velocity.The experiment system,which consists of drive and actuation system,water pool,model test sections,load cell,and control system,was presented.Water entry forces of different velocities were measured during impact process,and for each test case,three runs were performed with the same motion program to check the repeatability of the force readings.The experiment results are compared with two-dimensional(2D) CFD simulation methods for flatted-bottom rigid bodies with constant entry velocity.Experimental results indicate that the impact forces mainly depend on water entry velocities.It is concluded that the feasibility and accuracy of simulation methods has been validated.展开更多
China＇s capital market is different from that of the US in economic, political, and socio-cultural ways. China＇s dynamic and fast growing economy for the past decade entails some structural changes and weaknesses an...China＇s capital market is different from that of the US in economic, political, and socio-cultural ways. China＇s dynamic and fast growing economy for the past decade entails some structural changes and weaknesses and as a consequence, there are some business failures. We propose bankruptcy prediction models using Chinese firm data via several data mining tools and traditional logit analysis. We used Chinese firm data one year prior to bankruptcy and our results suggest that the financial variables developed by Altman （1968） and Ohlson （1980） perform reasonably well in determining business failures of Chinese firms, but the overall prediction rate is low compared with those of the US or other countries＇ studies. The reasons for this low prediction rate may be structural weaknesses resulting from China＇s fast growth and immature capital market.展开更多
Objective Natural language processing (NLP) was used to excavate and visualize the core content of syndrome element syndrome differentiation (SESD). Methods The first step was to build a text mining and analysis envir...Objective Natural language processing (NLP) was used to excavate and visualize the core content of syndrome element syndrome differentiation (SESD). Methods The first step was to build a text mining and analysis environment based on Python language, and built a corpus based on the core chapters of SESD. The second step was to digitalize the corpus. The main steps included word segmentation, information cleaning and merging, document-entry matrix, dictionary compilation and information conversion. The third step was to mine and display the internal information of SESD corpus by means of word cloud, keyword extraction and visualization. Results NLP played a positive role in computer recognition and comprehension of SESD. Different chapters had different keywords and weights. Deficiency syndrome elements were an important component of SESD, such as "Qi deficiency""Yang deficiency" and "Yin deficiency". The important syndrome elements of substantiality included "Blood stasis""Qi stagnation", etc. Core syndrome elements were closely related. Conclusions Syndrome differentiation and treatment was the core of SESD. Using NLP to excavate syndromes differentiation could help reveal the internal relationship between syndromes differentiation and provide basis for artificial intelligence to learn syndromes differentiation.展开更多
The resonant tunneling diode (RTD) is a kind of novel ultra-high speed and ultra-high frequency negative differential resistance nanoelectronic device. Integration of RTD and other three-terminal compound semiconducto...The resonant tunneling diode (RTD) is a kind of novel ultra-high speed and ultra-high frequency negative differential resistance nanoelectronic device. Integration of RTD and other three-terminal compound semiconductor devices is one important direction of high speed integrated circuit development. In this paper, monolithic integration technology of RTD and high electron mobility transistor (HEMT) based on GaAs substrate was discussed. A top-RTD and bottom-HEMT material structure was proposed and epitaxyed. Based on wet chemical etching, electron beam lithography, metal lift-off and air bridge technology, RTD and HEMT were fabricated on the same wafer. The peak-to-valley current ratio of RTD is 4 and the peak voltage is 0.5 V. The maximal transconductance is 120 mS/mm for a 0.25 μm gate length depletion mode HEMT. Current levels of two devices are basically suited. The results validate the feasibility of the designed integration process.展开更多
This paper discusses how to excavate the essence of Chinese traditional culture, In contemporary college moral education make some discussion from the historical and cultural educational ideas and way of education, Fo...This paper discusses how to excavate the essence of Chinese traditional culture, In contemporary college moral education make some discussion from the historical and cultural educational ideas and way of education, For higher education worker puts forward several ideas.展开更多
Previous weighted frequent pattern （WFP） mining algorithms are not suitable for data streams for they need multiple database scans. In this paper, we present an efficient algorithm SWFP-Miner to mine weighted freque...Previous weighted frequent pattern （WFP） mining algorithms are not suitable for data streams for they need multiple database scans. In this paper, we present an efficient algorithm SWFP-Miner to mine weighted frequent pattern over data streams. SWFP-Miner is based on sliding window and can discover important frequent pattern from the recent data. A new refined weight definition is proposed to keep the downward closure property, and two pruning strategies are presented to prune the weighted infrequent pattern. Experimental studies are performed to evaluate the effectiveness and efficiency of SWFP-Miner.展开更多
Work study is an area of construction production rationalization in which with scientific, logical, holistic and system analysis methods of the process we gain optimum in way of work and time of work. Chronometry meth...Work study is an area of construction production rationalization in which with scientific, logical, holistic and system analysis methods of the process we gain optimum in way of work and time of work. Chronometry method is one of the work study methods which is appropriate for recording shorter cyclic processes and is based on statistical sampling theory. Determination of cyclic times and work performances of standard cyclic construction machines （SCCM） is one of key assumptions of dynamic planning of machine work on every construction site. Calculation methods of SCCM work performances arc one of basic research objects in the field of construction organization and technology. Study shows applied chronometry method in work of standard cyclic construction machine. Goal of this study is to accomplish regulation through measured time cycle and compare measured effects with effects obtained with standard methodology of calculating hydraulic excavator practical achievement for gaining regulation in order to determine main reasons which effect work performance on site.展开更多
基金Projects (50934006, 10872218) supported by the National Natural Science Foundation of ChinaProject (2010CB732004) supported by the National Basic Research Program of China
文摘The 3D numerical simulation model of deep hard-rock deposit in Kaiyang Phosphate Mine of Guiyang was established based on the practical engineering using 3DEC numerical simulation software. The distribution characteristics of displacement fields and plastic zones of the orebody were simulated in three different excavation cases, including the case of excavation artificial inducted roadway in the orebody, the case of horizontal or vertical excavation direction and the case of the upward or downward excavation order. The simulation results indicate that the plastic zone and displacement field of surrounding rock around the inducted roadway are continuously increasing with the increase of the exposure time after digging an artificial inducted roadway in the orebody. Thus the raw rock ore becomes easier to be fragmented, which provides advantageous conditions for roadheader to cut high stress hard-rock. It is worthy noting that there is a large difference in effective utilization of deep ground pressure between horizontal and vertical excavation directions. The later can produce larger deformation and fracture zone than the former on the rock mass around the deduced roadway, which means that the later may utilize the high ground pressure more effectively to break hard-rock. And the obtained results also show that upward excavation order is more helpful for ground pressure to break rock than downward excavation order.
基金Under the auspices of Special Fund of Ministry of Land and Resources of China in Public Interest(No.201511001)
文摘Association rule mining methods, as a set of important data mining tools, could be used for mining spatial association rules of spatial data. However, applications of these methods are limited for mining results containing large number of redundant rules. In this paper, a new method named Geo-Filtered Association Rules Mining(GFARM) is proposed to effectively eliminate the redundant rules. An application of GFARM is performed as a case study in which association rules are discovered between building land distribution and potential driving factors in Wuhan, China from 1995 to 2015. Ten sets of regular sampling grids with different sizes are used for detecting the influence of multi-scales on GFARM. Results show that the proposed method can filter 50%–70% of redundant rules. GFARM is also successful in discovering spatial association pattern between building land distribution and driving factors.
基金Project(51305463)supported by National Natural Science Foundation of ChinaProject(2012QNZT01601005125)supported by Free Exploration Plan of Central South University,ChinaProject supported by Postdoctoral Foundation of Central South university,China
文摘A numerical wave load model based on two-phase(water-air) Reynolds-Averaged Navier Stokes(RANS) type equations is used to evaluate hydrodynamic forces exerted on flatted-bottom seafloor mining tool during its entering ocean waves of deploying process.The discretization of the RANS equations is achieved by a finite volume approach(FV).The volume of fluid method(VOF) is employed to track the complicated free surface.A numerical wave tank is built to generate the ocean waves which are suitable for deploying seafloor mining tool.A typical deploying condition is employed to reflect the process of flatted-bottom body impacting with waves,and the pressure distribution of bottom is also presented.Four different lowering velocities are applied to obtain the time histories of maximum pressure of bottom,and it can be concluded that the pressure coefficient decreases with water velocity increasing,which is similar with ordinary water entry case.The numerical results clearly demonstrate the characteristics of flatted-bottom body entering ocean waves.
基金Project(51074179)supported by National Natural Science Foundation of ChinaProject(2012QNZT01601005125)supported by Free Exploration Plan of Central South University,China
文摘A test rig for constant velocity water entry experiments was developed that drives a flatted-bottom section attached on six degree of freedom(6-DOF) platform to enter the water vertically at near constant velocity.The experiment system,which consists of drive and actuation system,water pool,model test sections,load cell,and control system,was presented.Water entry forces of different velocities were measured during impact process,and for each test case,three runs were performed with the same motion program to check the repeatability of the force readings.The experiment results are compared with two-dimensional(2D) CFD simulation methods for flatted-bottom rigid bodies with constant entry velocity.Experimental results indicate that the impact forces mainly depend on water entry velocities.It is concluded that the feasibility and accuracy of simulation methods has been validated.
文摘China＇s capital market is different from that of the US in economic, political, and socio-cultural ways. China＇s dynamic and fast growing economy for the past decade entails some structural changes and weaknesses and as a consequence, there are some business failures. We propose bankruptcy prediction models using Chinese firm data via several data mining tools and traditional logit analysis. We used Chinese firm data one year prior to bankruptcy and our results suggest that the financial variables developed by Altman （1968） and Ohlson （1980） perform reasonably well in determining business failures of Chinese firms, but the overall prediction rate is low compared with those of the US or other countries＇ studies. The reasons for this low prediction rate may be structural weaknesses resulting from China＇s fast growth and immature capital market.
基金the funding support from the National Natural Science Foundation of China (No. 81874429)Digital and Applied Research Platform for Diagnosis of Traditional Chinese Medicine (No. 49021003005)+1 种基金2018 Hunan Provincial Postgraduate Research Innovation Project (No. CX2018B465)Excellent Youth Project of Hunan Education Department in 2018 (No. 18B241)
文摘Objective Natural language processing (NLP) was used to excavate and visualize the core content of syndrome element syndrome differentiation (SESD). Methods The first step was to build a text mining and analysis environment based on Python language, and built a corpus based on the core chapters of SESD. The second step was to digitalize the corpus. The main steps included word segmentation, information cleaning and merging, document-entry matrix, dictionary compilation and information conversion. The third step was to mine and display the internal information of SESD corpus by means of word cloud, keyword extraction and visualization. Results NLP played a positive role in computer recognition and comprehension of SESD. Different chapters had different keywords and weights. Deficiency syndrome elements were an important component of SESD, such as "Qi deficiency""Yang deficiency" and "Yin deficiency". The important syndrome elements of substantiality included "Blood stasis""Qi stagnation", etc. Core syndrome elements were closely related. Conclusions Syndrome differentiation and treatment was the core of SESD. Using NLP to excavate syndromes differentiation could help reveal the internal relationship between syndromes differentiation and provide basis for artificial intelligence to learn syndromes differentiation.
基金Supported by Funds of National Defense Technology Key Laboratory (NO.9140C060203060C0603)China Postdoctoral Science Foundation(NO.20060400189) .
文摘The resonant tunneling diode (RTD) is a kind of novel ultra-high speed and ultra-high frequency negative differential resistance nanoelectronic device. Integration of RTD and other three-terminal compound semiconductor devices is one important direction of high speed integrated circuit development. In this paper, monolithic integration technology of RTD and high electron mobility transistor (HEMT) based on GaAs substrate was discussed. A top-RTD and bottom-HEMT material structure was proposed and epitaxyed. Based on wet chemical etching, electron beam lithography, metal lift-off and air bridge technology, RTD and HEMT were fabricated on the same wafer. The peak-to-valley current ratio of RTD is 4 and the peak voltage is 0.5 V. The maximal transconductance is 120 mS/mm for a 0.25 μm gate length depletion mode HEMT. Current levels of two devices are basically suited. The results validate the feasibility of the designed integration process.
文摘This paper discusses how to excavate the essence of Chinese traditional culture, In contemporary college moral education make some discussion from the historical and cultural educational ideas and way of education, For higher education worker puts forward several ideas.
文摘Previous weighted frequent pattern （WFP） mining algorithms are not suitable for data streams for they need multiple database scans. In this paper, we present an efficient algorithm SWFP-Miner to mine weighted frequent pattern over data streams. SWFP-Miner is based on sliding window and can discover important frequent pattern from the recent data. A new refined weight definition is proposed to keep the downward closure property, and two pruning strategies are presented to prune the weighted infrequent pattern. Experimental studies are performed to evaluate the effectiveness and efficiency of SWFP-Miner.
文摘Work study is an area of construction production rationalization in which with scientific, logical, holistic and system analysis methods of the process we gain optimum in way of work and time of work. Chronometry method is one of the work study methods which is appropriate for recording shorter cyclic processes and is based on statistical sampling theory. Determination of cyclic times and work performances of standard cyclic construction machines （SCCM） is one of key assumptions of dynamic planning of machine work on every construction site. Calculation methods of SCCM work performances arc one of basic research objects in the field of construction organization and technology. Study shows applied chronometry method in work of standard cyclic construction machine. Goal of this study is to accomplish regulation through measured time cycle and compare measured effects with effects obtained with standard methodology of calculating hydraulic excavator practical achievement for gaining regulation in order to determine main reasons which effect work performance on site.
