The dynamics of inviscid multi-component relativistic fluids may be modeled by the relativistic Euler equations, augmented by one (or more) additional species equation(s). We use the high-resolution staggered central ...The dynamics of inviscid multi-component relativistic fluids may be modeled by the relativistic Euler equations, augmented by one (or more) additional species equation(s). We use the high-resolution staggered central schemes to solve these equations. The equilibrium states for each component are coupled in space and time to have a common temperature and velocity. The current schemes can handle strong shocks and the oscillations near the interfaces are negligible, which usually happens in the multi-component flows. The schemes also guarantee the exact mass conservation for each component, the exact conservation of total momentum, and energy in the whole particle system. The central schemes are robust, reliable, compact and easy to implement. Several one- and two-dimensional numerical test cases are included in this paper, which validate the application of these schemes to relativistic multi-component flows.展开更多
To research the effect of the selection method of multi-objects genetic algorithm problem on optimizing result, thismethod is analyzed theoretically and discussed by using an autonomous underwater vehicle(AUV) as an o...To research the effect of the selection method of multi-objects genetic algorithm problem on optimizing result, thismethod is analyzed theoretically and discussed by using an autonomous underwater vehicle(AUV) as an object. A changingweight vtlue method is put forward and a selection formula is modified. Some experiments were implemented on an AUV.TwinBurger. The results shows that this method is effective and feasible.展开更多
In the video-based surveillance application, moving shadows can affect the correct localization and detection of moving objects. This paper aims to present a method for shadow detection and suppression used for moving...In the video-based surveillance application, moving shadows can affect the correct localization and detection of moving objects. This paper aims to present a method for shadow detection and suppression used for moving visual object detection. The major novelty of the shadow suppression is the integration of several features including photometric invariant color feature, motion edge feature, and spatial feature etc. By modifying process for false shadow detected, the averaging detection rate of moving object reaches above 90% in the test of Hall-Monitor sequence.展开更多
The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST, also called the Guo Shou Jing Telescope) is a special reflecting Schmidt telescope. LAMOST’s special design allows both a large aperture (effecti...The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST, also called the Guo Shou Jing Telescope) is a special reflecting Schmidt telescope. LAMOST’s special design allows both a large aperture (effective aperture of 3.6 m–4.9 m) and a wide field of view (FOV) (5°). It has an innovative active reflecting Schmidt configuration which continuously changes the mirror’s surface that adjusts during the observation process and combines thin deformable mirror active optics with segmented active optics. Its primary mirror (6.67m×6.05 m) and active Schmidt mirror (5.74m×4.40 m) are both segmented, and composed of 37 and 24 hexagonal sub-mirrors respectively. By using a parallel controllable fiber positioning technique, the focal surface of 1.75 m in diameter can accommodate 4000 optical fibers. Also, LAMOST has 16 spectrographs with 32 CCD cameras. LAMOST will be the telescope with the highest rate of spectral acquisition. As a national large scientific project, the LAMOST project was formally proposed in 1996, and approved by the Chinese government in 1997. The construction started in 2001, was completed in 2008 and passed the official acceptance in June 2009. The LAMOST pilot survey was started in October 2011 and the spectroscopic survey will launch in September 2012. Up to now, LAMOST has released more than 480 000 spectra of objects. LAMOST will make an important contribution to the study of the large-scale structure of the Universe, structure and evolution of the Galaxy, and cross-identification of multiwaveband properties in celestial objects.展开更多
To obtain the optimal process parameters of stamping forming, finite element analysis and optimization technique were integrated via transforming multi-objective issue into a single-objective issue. A Pareto-based gen...To obtain the optimal process parameters of stamping forming, finite element analysis and optimization technique were integrated via transforming multi-objective issue into a single-objective issue. A Pareto-based genetic algorithm was applied to optimizing the head stamping forming process. In the proposed optimal model, fracture, wrinkle and thickness varying are a function of several factors, such as fillet radius, draw-bead position, blank size and blank-holding force. Hence, it is necessary to investigate the relationship between the objective functions and the variables in order to make objective functions varying minimized simultaneously. Firstly, the central composite experimental(CCD) with four factors and five levels was applied, and the experimental data based on the central composite experimental were acquired. Then, the response surface model(RSM) was set up and the results of the analysis of variance(ANOVA) show that it is reliable to predict the fracture, wrinkle and thickness varying functions by the response surface model. Finally, a Pareto-based genetic algorithm was used to find out a set of Pareto front, which makes fracture, wrinkle and thickness varying minimized integrally. A head stamping case indicates that the present method has higher precision and practicability compared with the "trial and error" procedure.展开更多
Objective To compare the acute hemodynamic effects of five different pacing modes in patients with cardiac function NYHA class Ⅰ to Ⅱ without bundle branch block (BBB). Methods This study included 12 patients (SSS ...Objective To compare the acute hemodynamic effects of five different pacing modes in patients with cardiac function NYHA class Ⅰ to Ⅱ without bundle branch block (BBB). Methods This study included 12 patients (SSS 7, Ⅲ°AVB 5) undergoing pacemaker implantation. Right ventricular apex (RVA), right ventricular outflow tract (RVOT), right ventricular bifocal (RV-Bi), left ventricular base (LVB) and bi -ventricular (Bi-Ⅴ) pacing at 60 -80 ppm were done in VVI mode prior to implantation of DDD pacemaker. The cardiac index (CI), mean pulmonary artery pressure (mPAP) and pulmonary capillary wedge pressure (PCWP) were measured with Swan - Ganz thermodilution catheter after 5 minutes of each pacing mode. Results (1) Comparing to pacing at RVA (CI: 2. 41± 0. 38 L/min per m2, PCWP: 16. 7 ±3.3 mmHg), the CI increased and the PCWP decreased significantly in pacing at RVOT(CI: 2. 63 ± 0.46, PCWP: 13. 8±2. 3), LVB(CI: 2. 78±0.52, PCWP: 14. 4±3.1), RV-Bi(CI: 2. 83±0.57, PCWP: 12. 8± 2. 5) and Bi -Ⅴ pacing (CI: 2. 94± 0.60, PCWP: 12. 7±2. 5), P < 0. 01, respectively. (2) The CI of RV-Bi and Bi-Ⅴ pacing was higher than that of RVOT and LVB pacing, the PCWP was lower, P < 0. 05, respectively. (3) There was no significant difference between RV - Bi pacing and Bi-Ⅴ pacing in CI and PCWP. Conclusion There is no significant difference between RV - Bi pacing and Bi -V pacing in the acute hemodynamic effects; however,dual - site pacing is much better than single site pacing in that aspect for patients with cardiac function NYHA class Ⅰ to Ⅱ without BBB. Among single site pacing, the RVOT and LVB pacing is better than RVA pacing in cardiac function.展开更多
In this paper, a successfully studied and developed master - slave muld - microcomputers control system based on PC - BUS for hollow spindle fancy yarn spinning machine, mainly Its overall scheme, software and hardwar...In this paper, a successfully studied and developed master - slave muld - microcomputers control system based on PC - BUS for hollow spindle fancy yarn spinning machine, mainly Its overall scheme, software and hardware construction, is introduced. Spinning experiments show that the system achieves satisfactory result. This system can solve the diftkultles of mechatronical fusion between domestic hollow splndk fancy yarn spuming muchine and its microcomputer control technology.展开更多
A quantitative method is developed to identify the structures of multi-layer woven fabric in this study. Six structural parameters are selected to represent the fabric structure. With some design criteria for the rein...A quantitative method is developed to identify the structures of multi-layer woven fabric in this study. Six structural parameters are selected to represent the fabric structure. With some design criteria for the reinforcement of textile composites, the relationships among the structural parameters are derived for different binding patterns of the fabric structure. The conditions, which meet the requirements of structural cell stability,are also discussed.展开更多
To meet the development trend of multi-bar warp knit-ting machine towards high-speed,advanced technologyand computer control and the requirements of variousproducts with small quantity,there are many researcheson the ...To meet the development trend of multi-bar warp knit-ting machine towards high-speed,advanced technologyand computer control and the requirements of variousproducts with small quantity,there are many researcheson the computer-aided pattern design of multi-barwarp knitted fabrics.In terms of the special propertiesof the computer-aided pattern design of multi-barwarp knitted fabrics,the Object Oriented Program(OOP)programming-Object Windows class Library(OWL)programming is selected.According to thecharacters of the OWL programming,various functionsare defined.Pattern design and technical parameters canbe output,which offers a great convenience for the fac-tory.展开更多
<strong>Introduction</strong> In Central-African Republic, according to UNAIDS in 2019, out of approximately 100,000 people living with HIV, 70% (72,000) knew their HIV status and 47,000 (46%) were on ARV ...<strong>Introduction</strong> In Central-African Republic, according to UNAIDS in 2019, out of approximately 100,000 people living with HIV, 70% (72,000) knew their HIV status and 47,000 (46%) were on ARV therapy;however, there is a paucity of data on viral load suppression in people on ARV therapy. The objective of this study was to assess the third 90 of the UNAIDS strategy for the years 2019 and 2020 in the CAR. <strong>Methods</strong> We analyzed the available viral load data extracted from the data base of the medical analysis laboratory (SYSLAM) of the Institut Pasteur of Bangui for the years 2019 and 2020. The viral loads were determined based on plasma collected in an EDTA tube with Cepheid’s GeneXpert<sup><span style="white-space:nowrap;">®</span></sup> 16-module controllers. Viral load data were extracted from SYSLAM, converted to Excel format, and analyzed with STATA version 14 software. The significance threshold for the statistical tests was set at 5%. <strong>Results</strong> This study included 22,895 patients, of who 72% were female. The average age was 40.82 years, and the majority of the patients (80%) came from the city of Bangui. Regarding the virological parameters associated with this study, 66% of the patients had significant viral load suppression according to the WHO recommendations and 34% were in virological failure. Patients over 50 years of age (71.85%) and age group 40 - 49 years (69.25%) recorded significant levels of viral load suppression. On the other hand, 63.45% of patients under 18 years of age had virological failure. All of these results were statistically significant (p < 0.005). <strong>Conclusion</strong> There should be a concerted effort, to make viral load accessible and available to all patients receiving ARV treatment in the CAR and the management of HIV/AIDS infection of children and adolescents should be given special attention.展开更多
混合光伏-热电(centralized hybrid photovoltaic thermoelectric generator,PV-TEG)系统在部分遮蔽(partial shading condition,PSC)条件下呈现多个局部最大功率点(local maximum power point,LMPP)。采用多元宇宙优化算法(multi-verse...混合光伏-热电(centralized hybrid photovoltaic thermoelectric generator,PV-TEG)系统在部分遮蔽(partial shading condition,PSC)条件下呈现多个局部最大功率点(local maximum power point,LMPP)。采用多元宇宙优化算法(multi-verse optimization,MVO),用于PV-TEG系统在PSC下的最大功率点跟踪(maximum power point tracking,MPPT)。MVO通过平衡全局搜索和局部搜索,有效识别多个LMPPs中唯一的全局最大功率点(global maximum power point,GMPP),避免搜索结果陷入LMPP,以提高发电效率和能源利用率。算例仿真结果表明:基于MVO的MPPT可以在更短的时间内收集到更高的功率,实现功率波动最小。展开更多
To realize the continuous and variable gait transition for a new type of arthropod robot, a multi-level gait transition model is studied in this paper. The model is composed of central pattern generator (CPG) and sa...To realize the continuous and variable gait transition for a new type of arthropod robot, a multi-level gait transition model is studied in this paper. The model is composed of central pattern generator (CPG) and saturation function. The CPG consists of four pairs of oscillators which can ex- hibit rhythmic activity when given stimulation signal S that lies in the range of saturation function. All oscillators receive the same S, but each pair of oscillators has different saturation functions. Multi- level gait transition can be realized when S changes regularly, as the oscillators start or stop oscilla- ting at different times. After computer simulation, the gait transition model is implemented in the ar- thropod robot. The experimental results show that ideal gait transition for the arthropod robot can be realized with the multi-level gait transition model.展开更多
文摘The dynamics of inviscid multi-component relativistic fluids may be modeled by the relativistic Euler equations, augmented by one (or more) additional species equation(s). We use the high-resolution staggered central schemes to solve these equations. The equilibrium states for each component are coupled in space and time to have a common temperature and velocity. The current schemes can handle strong shocks and the oscillations near the interfaces are negligible, which usually happens in the multi-component flows. The schemes also guarantee the exact mass conservation for each component, the exact conservation of total momentum, and energy in the whole particle system. The central schemes are robust, reliable, compact and easy to implement. Several one- and two-dimensional numerical test cases are included in this paper, which validate the application of these schemes to relativistic multi-component flows.
文摘To research the effect of the selection method of multi-objects genetic algorithm problem on optimizing result, thismethod is analyzed theoretically and discussed by using an autonomous underwater vehicle(AUV) as an object. A changingweight vtlue method is put forward and a selection formula is modified. Some experiments were implemented on an AUV.TwinBurger. The results shows that this method is effective and feasible.
文摘In the video-based surveillance application, moving shadows can affect the correct localization and detection of moving objects. This paper aims to present a method for shadow detection and suppression used for moving visual object detection. The major novelty of the shadow suppression is the integration of several features including photometric invariant color feature, motion edge feature, and spatial feature etc. By modifying process for false shadow detected, the averaging detection rate of moving object reaches above 90% in the test of Hall-Monitor sequence.
文摘The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST, also called the Guo Shou Jing Telescope) is a special reflecting Schmidt telescope. LAMOST’s special design allows both a large aperture (effective aperture of 3.6 m–4.9 m) and a wide field of view (FOV) (5°). It has an innovative active reflecting Schmidt configuration which continuously changes the mirror’s surface that adjusts during the observation process and combines thin deformable mirror active optics with segmented active optics. Its primary mirror (6.67m×6.05 m) and active Schmidt mirror (5.74m×4.40 m) are both segmented, and composed of 37 and 24 hexagonal sub-mirrors respectively. By using a parallel controllable fiber positioning technique, the focal surface of 1.75 m in diameter can accommodate 4000 optical fibers. Also, LAMOST has 16 spectrographs with 32 CCD cameras. LAMOST will be the telescope with the highest rate of spectral acquisition. As a national large scientific project, the LAMOST project was formally proposed in 1996, and approved by the Chinese government in 1997. The construction started in 2001, was completed in 2008 and passed the official acceptance in June 2009. The LAMOST pilot survey was started in October 2011 and the spectroscopic survey will launch in September 2012. Up to now, LAMOST has released more than 480 000 spectra of objects. LAMOST will make an important contribution to the study of the large-scale structure of the Universe, structure and evolution of the Galaxy, and cross-identification of multiwaveband properties in celestial objects.
基金Project(2012ZX04010-081) supported by the National Science and Technology Major Project of the Ministry of Science and Technology of China
文摘To obtain the optimal process parameters of stamping forming, finite element analysis and optimization technique were integrated via transforming multi-objective issue into a single-objective issue. A Pareto-based genetic algorithm was applied to optimizing the head stamping forming process. In the proposed optimal model, fracture, wrinkle and thickness varying are a function of several factors, such as fillet radius, draw-bead position, blank size and blank-holding force. Hence, it is necessary to investigate the relationship between the objective functions and the variables in order to make objective functions varying minimized simultaneously. Firstly, the central composite experimental(CCD) with four factors and five levels was applied, and the experimental data based on the central composite experimental were acquired. Then, the response surface model(RSM) was set up and the results of the analysis of variance(ANOVA) show that it is reliable to predict the fracture, wrinkle and thickness varying functions by the response surface model. Finally, a Pareto-based genetic algorithm was used to find out a set of Pareto front, which makes fracture, wrinkle and thickness varying minimized integrally. A head stamping case indicates that the present method has higher precision and practicability compared with the "trial and error" procedure.
文摘Objective To compare the acute hemodynamic effects of five different pacing modes in patients with cardiac function NYHA class Ⅰ to Ⅱ without bundle branch block (BBB). Methods This study included 12 patients (SSS 7, Ⅲ°AVB 5) undergoing pacemaker implantation. Right ventricular apex (RVA), right ventricular outflow tract (RVOT), right ventricular bifocal (RV-Bi), left ventricular base (LVB) and bi -ventricular (Bi-Ⅴ) pacing at 60 -80 ppm were done in VVI mode prior to implantation of DDD pacemaker. The cardiac index (CI), mean pulmonary artery pressure (mPAP) and pulmonary capillary wedge pressure (PCWP) were measured with Swan - Ganz thermodilution catheter after 5 minutes of each pacing mode. Results (1) Comparing to pacing at RVA (CI: 2. 41± 0. 38 L/min per m2, PCWP: 16. 7 ±3.3 mmHg), the CI increased and the PCWP decreased significantly in pacing at RVOT(CI: 2. 63 ± 0.46, PCWP: 13. 8±2. 3), LVB(CI: 2. 78±0.52, PCWP: 14. 4±3.1), RV-Bi(CI: 2. 83±0.57, PCWP: 12. 8± 2. 5) and Bi -Ⅴ pacing (CI: 2. 94± 0.60, PCWP: 12. 7±2. 5), P < 0. 01, respectively. (2) The CI of RV-Bi and Bi-Ⅴ pacing was higher than that of RVOT and LVB pacing, the PCWP was lower, P < 0. 05, respectively. (3) There was no significant difference between RV - Bi pacing and Bi-Ⅴ pacing in CI and PCWP. Conclusion There is no significant difference between RV - Bi pacing and Bi -V pacing in the acute hemodynamic effects; however,dual - site pacing is much better than single site pacing in that aspect for patients with cardiac function NYHA class Ⅰ to Ⅱ without BBB. Among single site pacing, the RVOT and LVB pacing is better than RVA pacing in cardiac function.
文摘In this paper, a successfully studied and developed master - slave muld - microcomputers control system based on PC - BUS for hollow spindle fancy yarn spinning machine, mainly Its overall scheme, software and hardware construction, is introduced. Spinning experiments show that the system achieves satisfactory result. This system can solve the diftkultles of mechatronical fusion between domestic hollow splndk fancy yarn spuming muchine and its microcomputer control technology.
文摘A quantitative method is developed to identify the structures of multi-layer woven fabric in this study. Six structural parameters are selected to represent the fabric structure. With some design criteria for the reinforcement of textile composites, the relationships among the structural parameters are derived for different binding patterns of the fabric structure. The conditions, which meet the requirements of structural cell stability,are also discussed.
文摘To meet the development trend of multi-bar warp knit-ting machine towards high-speed,advanced technologyand computer control and the requirements of variousproducts with small quantity,there are many researcheson the computer-aided pattern design of multi-barwarp knitted fabrics.In terms of the special propertiesof the computer-aided pattern design of multi-barwarp knitted fabrics,the Object Oriented Program(OOP)programming-Object Windows class Library(OWL)programming is selected.According to thecharacters of the OWL programming,various functionsare defined.Pattern design and technical parameters canbe output,which offers a great convenience for the fac-tory.
文摘<strong>Introduction</strong> In Central-African Republic, according to UNAIDS in 2019, out of approximately 100,000 people living with HIV, 70% (72,000) knew their HIV status and 47,000 (46%) were on ARV therapy;however, there is a paucity of data on viral load suppression in people on ARV therapy. The objective of this study was to assess the third 90 of the UNAIDS strategy for the years 2019 and 2020 in the CAR. <strong>Methods</strong> We analyzed the available viral load data extracted from the data base of the medical analysis laboratory (SYSLAM) of the Institut Pasteur of Bangui for the years 2019 and 2020. The viral loads were determined based on plasma collected in an EDTA tube with Cepheid’s GeneXpert<sup><span style="white-space:nowrap;">®</span></sup> 16-module controllers. Viral load data were extracted from SYSLAM, converted to Excel format, and analyzed with STATA version 14 software. The significance threshold for the statistical tests was set at 5%. <strong>Results</strong> This study included 22,895 patients, of who 72% were female. The average age was 40.82 years, and the majority of the patients (80%) came from the city of Bangui. Regarding the virological parameters associated with this study, 66% of the patients had significant viral load suppression according to the WHO recommendations and 34% were in virological failure. Patients over 50 years of age (71.85%) and age group 40 - 49 years (69.25%) recorded significant levels of viral load suppression. On the other hand, 63.45% of patients under 18 years of age had virological failure. All of these results were statistically significant (p < 0.005). <strong>Conclusion</strong> There should be a concerted effort, to make viral load accessible and available to all patients receiving ARV treatment in the CAR and the management of HIV/AIDS infection of children and adolescents should be given special attention.
文摘混合光伏-热电(centralized hybrid photovoltaic thermoelectric generator,PV-TEG)系统在部分遮蔽(partial shading condition,PSC)条件下呈现多个局部最大功率点(local maximum power point,LMPP)。采用多元宇宙优化算法(multi-verse optimization,MVO),用于PV-TEG系统在PSC下的最大功率点跟踪(maximum power point tracking,MPPT)。MVO通过平衡全局搜索和局部搜索,有效识别多个LMPPs中唯一的全局最大功率点(global maximum power point,GMPP),避免搜索结果陷入LMPP,以提高发电效率和能源利用率。算例仿真结果表明:基于MVO的MPPT可以在更短的时间内收集到更高的功率,实现功率波动最小。
基金Supported by the Ministerial Level Advanced Research Foundation(65822576)
文摘To realize the continuous and variable gait transition for a new type of arthropod robot, a multi-level gait transition model is studied in this paper. The model is composed of central pattern generator (CPG) and saturation function. The CPG consists of four pairs of oscillators which can ex- hibit rhythmic activity when given stimulation signal S that lies in the range of saturation function. All oscillators receive the same S, but each pair of oscillators has different saturation functions. Multi- level gait transition can be realized when S changes regularly, as the oscillators start or stop oscilla- ting at different times. After computer simulation, the gait transition model is implemented in the ar- thropod robot. The experimental results show that ideal gait transition for the arthropod robot can be realized with the multi-level gait transition model.