Global industrial chains(GICs)have become a hallmark of the world economy underpinning the global production cycle.Since the reform and opening up was introduced in 1978,China has taken an active role in global value ...Global industrial chains(GICs)have become a hallmark of the world economy underpinning the global production cycle.Since the reform and opening up was introduced in 1978,China has taken an active role in global value chains(GVCs)and become the world’s factory floor.Under the external shocks to GICs,such as US trade frictions with China and the COVID-19 pandemic,China’s traditional comparative advantages in manufacturing which include its labor force and costs are waning.This has manifested in a wave of industrial relocations from China to other countries as well as China’s weakening international competitiveness.We took stock of the concepts and journey of GVCs and elaborated the intrinsic relationship between GVCs and the new development pattern of“dual circulations”.We also analyzed the trends of GVCs,the current status and problems of China’s industrial chains,and China’s market heft,complete industrial chains and the digital economy as new strengths for industrial chain upgrade.In our conclusion,this paper put forth some policy recommendations for China’s industrial chain upgrade in the context of dual circulations.展开更多
AIM: To compare small sphincterotomy combined with endoscopic papillary large balloon dilation (SES + ELBD) and endoscopic sphincterotomy (EST) for large bile duct stones. METHODS: We compared prospectively SES...AIM: To compare small sphincterotomy combined with endoscopic papillary large balloon dilation (SES + ELBD) and endoscopic sphincterotomy (EST) for large bile duct stones. METHODS: We compared prospectively SES + ELBD (group A, n = 27) with conventional EST (group B, n = 28) for the treatment of large bile duct stones (≥ 15 mm). When the stone could not be removed with a normal basket, mechanical lithotripsy was performed. We compared the rates of complete stone removal with one session and application of mechanical lithotripsy. RESULTS: No significant differences were observed in the mean largest stone size (A: 20.8 mm, B: 21.3 mm), bile duct diameter (A: 21.4 turn, B: 20.5 ram), number of stones (A: 2.2, B: 2.3), or procedure time (A: 18 min, B: 19 rain) between the two groups. The rates of complete stone removal with one session was 85% in group A and 86% in group B (P = 0.473). Mechanical lithotripsy was required for stone removal in nine of 27 patients (33%) in group A and nine of 28 patients (32%, P = 0.527) in group B.CONCLUSION: SES + ELBD did not show significant benefits compared to conventional EST, especially for the removal of large (≥ 15 mm) bile duct stones.展开更多
The temporal variability and spatial pattern of the Arctic Oscillation(AO)simulated in the historical experiment of26 coupled climate models participating in the Coupled Model Intercomparison Project Phase 5(CMIP5)are...The temporal variability and spatial pattern of the Arctic Oscillation(AO)simulated in the historical experiment of26 coupled climate models participating in the Coupled Model Intercomparison Project Phase 5(CMIP5)are evaluated.Spectral analysis of the monthly AO index indicates that 23 out of the 26 CMIP5 models exhibit no statistically significant spectral peak in the historical experiment,as seen in the observations.These models are able to reproduce the AO pattern in the sea level pressure anomaly field during boreal winter,but the intensity of the AO pattern tends to be overestimated in all the models.The zonal-mean zonal wind anomalies associated with the AO is dominated by a meridional dipole in the mid-high latitudes of the Northern Hemisphere during boreal winter,which is well reproduced by only a few models.Most models show significant biases in both strength and location of the dipole compared to the observation.In considering the temporal variability as well as spatial structures in both horizontal and vertical directions,the MPI-ESM-P model reproduces an AO pattern that resembles the observation the best.展开更多
Urban competition refers to capacities of cities for attracting, capturing, controlling, dominating and transforming certain resources during urban development, and capacities for wealth creating, life-standard improv...Urban competition refers to capacities of cities for attracting, capturing, controlling, dominating and transforming certain resources during urban development, and capacities for wealth creating, life-standard improving and sustainable development maintenance. This paper first analyzes the external sources of urban competitive advantages: the global network-based advantages and the location-based ones. Then with the aid of method of principal component analysis in SPSS 10.0 for Windows, the Chinese urban global and local competitive advantages are explored. The finding is that the global network-and location-based advantages are remarkable for the cities in the eastern China. While for those in the western and the middle regions, affected by much lower regional competitive advantages and lower degrees of urban-regional integration, the urban competitive advantages are deeply influenced and weakened.展开更多
This study aims to find the altitudinal distribution pattern of vascular plant species reported from high mountain of Nepal(Manang) along the whole Himalayan elevation gradient, and evaluate their fate against climate...This study aims to find the altitudinal distribution pattern of vascular plant species reported from high mountain of Nepal(Manang) along the whole Himalayan elevation gradient, and evaluate their fate against climate change. Data was gathered from multiple sources, field investigations, literatures, and herbarium specimens. Altogether, 303 vascular plant species were reported from Manang. We used a published data to calculate distribution range of each species by interpolating between its upper and lower elevation limits. The relationship between elevation and species richness is elucidated by generalized linear model. The consequence of global warming upon Manang's vascular plant species was estimated based on projected temperature change for next century and adiabatic lapse rate along the elevation gradient of the Himalayas. The vascular plant species richness has a unimodel relationship with elevation along the whole elevation gradient of Nepal as well as in three biogeographical regions of Nepal. Vascular plants of Manang are found distributed from low land Terai to high alpine regions of Nepal and their elevation distribution range varies from 200 to 4700 m. Out of 303 vascular plants of Manang, only seven species might be affected if temperature increase by 1.5°C, whereas at least 70 species will be affected with 5°C temperature increased. However, the majority of species(233 species) have wider distribution range(> 1000 m) and more than 5°C temperature tolerance range, thus they are likely to be less affected from global warming by the end of 21 st century.展开更多
A large sample size is required for Monte Carlo localization (MCL) in multi-robot dynamic environ- ment, because of the "kidnapped robot" phenomenon, which will locate most of the samples in the regions with small...A large sample size is required for Monte Carlo localization (MCL) in multi-robot dynamic environ- ment, because of the "kidnapped robot" phenomenon, which will locate most of the samples in the regions with small value of desired posterior density. For this problem the crossover and mutation operators in evolutionary computation are introduced into MCL to make samples move towards the regions where the desired posterior density is large, so that the sample set can represent the density better. The proposed method is termed genetic Monte Carlo localization (GMCL). Application in robot soccer system shows that GMCL can considerably reduce the required number of samples, and is more precise and robust in dynamic environment.展开更多
Objective: To investigate if intra-aortic balloon pump(IABP) is contraindicated without anticoag-ulation therapy. Methods: Some 153 IABP patients in the King Abdulaziz Cardiac Center(KSA) were random-ly assigned into ...Objective: To investigate if intra-aortic balloon pump(IABP) is contraindicated without anticoag-ulation therapy. Methods: Some 153 IABP patients in the King Abdulaziz Cardiac Center(KSA) were random-ly assigned into two groups. Anticoagulation group( Group A) consisted of 71 patients who were given heparin intravenously with target aPTT 50 - 70 seconds. Non-anticoagulation group( Group B) consisted of 82 patients without intravenous heparin during balloon pumping. Hematological parameters including platelet count, D-dimer, Plasminogen activator inhibitor-1 (PAI-1) and fibrinogen degradation products(FDP) were checked respectively at the point of baseline, 24 hours, 48 hours and 24 hours post IABP counterpulsation. Clot deposits on balloon surface, vascular complications from IABP including bleeding and limb ischemia were recorded.Results: Platelet count and PAI-1 level decreased at 24 hours and 48 hours in both groups ( P < 0.05) . D-dimer and FDP level increased at 24 hours and 48 hours in both groups( P < 0.05), but returned to the baseline level 24 hours post IABP removal( P > 0.05) . Three patients in Group A and 2 patients in Group B developed minor limb ischemia( P > 0.05). No major limb ischemia in either group. Two patients in Group A suffered major bleeding and required blood transfusion or surgical intervention, whereas no patient had major bleeding in Group B. Eight patients had minor bleeding in Group A, but only 2 patients in Group B ( P <0.05). No clot deposit developed on IABP surface in either group. Conclusion: IABP is safe without routine anticoagulation therapy. Selecting appropriate artery approach and early detection intervention are key methods for preventing complications.展开更多
In this study, using the Geophysical Fluid Dynamics Laboratory Climate Model version 2pl (GFDL CM2pl) coupled model, the winter predictability barrier (WPB) is found to exist in the model not only in the growing p...In this study, using the Geophysical Fluid Dynamics Laboratory Climate Model version 2pl (GFDL CM2pl) coupled model, the winter predictability barrier (WPB) is found to exist in the model not only in the growing phase but also the Indian Ocean dipole (IOD) decaying phase of positive events due to the effect of initial errors. In particular, the WPB is stronger in the growing phase than in the decaying phase. These results indicate that initial errors can cause the WPB. The domi- nant patterns of the initial errors that cause the occurrence of the WPB often present an eastern-western dipole both in the surface and subsurface temperature components. These initial errors tend to concentrate in a few areas, and these areas may represent the sensitive areas of the predictions of positive IOD events. By increasing observations over these areas and eliminating initial errors here, the WPB phenomenon may be largely weakened and the forecast skill greatly improved.展开更多
Due to the superimposed impacts of new industrial revolution,the changing trade policy and the COVID-19 pandemic,the world has seen setbacks in globalization,contractions in the global value chain(GVC),and the risk of...Due to the superimposed impacts of new industrial revolution,the changing trade policy and the COVID-19 pandemic,the world has seen setbacks in globalization,contractions in the global value chain(GVC),and the risk of a fragmented global system.The once-in-a-century changes in our world today highlight the need for China to explore a new development paradigm based on new concepts.In the new era,China must not only come to terms with a backlash against globalization and challenges from the reshaping of international rules,but also breathe life into the“dual circulations,”i.e.domestic and international economic circulations.China must open up wider to the outside world to keep abreast with changes in today’s global governance system.In the complex and volatile international environment,we should explore new areas of development spearheaded by institutional opening up,create new gateways and platforms for opening up and cooperation for mutual benefit,contribute to new global governance and security systems,and promote synergy between domestic and international circulations.In building a great modern socialist country,China must open up wider and be more inclusive to the outside world.展开更多
This study employed an innovative meth- odological framework that combines geomatics and conventional survey methods to monitor changes in forest conditions and examine their associations with local forest governance ...This study employed an innovative meth- odological framework that combines geomatics and conventional survey methods to monitor changes in forest conditions and examine their associations with local forest governance parameters in a mountain watershed covering 153.3 km2 in the middle moun- tains of Nepal. The study involved two spatial scales and analytical steps. First, geomatics techniques were used to map and detect changes in major land cover types in the watershed between 1976 and 2000 and to analyze relationships between forest cover changes and governance arrangements. This was followed by micro-level analysis of the relationships between the biological conditions of selected forests within the watershed and their governance arrangements, using conventional survey methods and analytical tools. The findings show that forest cover in the watershed in- creased by about 15 per cent during the period. The rate of increase in forest cover was highest in areas under a semi-government type of governance ar- rangement, while the community forests were gener- ally better in terms of current biological conditions compared to the semi-government forests. This in- consistency between the findings from the two analy- ses does not allow us to draw any firm conclusions regarding the role of property rights in determining forest condition, but it indicates that the outcomes of local forest management initiatives may be more de-pendent on local institutional arrangements regulat- ing forest use and maintenance of forest resources than on the type of property rights arrangements. The findings also provide evidence of the methodological suitability of the research approach adopted, which may be useful for addressing many other research questions related to forestry and natural resources management, particularly those involving multiple spatial scales.展开更多
This paper deals with the properties of the solution to a class of nonlocal degenerate reaction-diffusion equation with nonlocal source,subject to the null Dirichlet boundary condition.We first give sufficient conditi...This paper deals with the properties of the solution to a class of nonlocal degenerate reaction-diffusion equation with nonlocal source,subject to the null Dirichlet boundary condition.We first give sufficient conditions for that the solution exists globally or blows up in the finite time.Then the blow-up time is also given.At last,we obtain a property differing from the local source which the blow-up set is the entire interval.展开更多
With such significant advantages as all-day observation, penetrability and all-weather coverage, passive mi-crowave remote sensing technique has been widely applied in the research of global environmental change. As t...With such significant advantages as all-day observation, penetrability and all-weather coverage, passive mi-crowave remote sensing technique has been widely applied in the research of global environmental change. As the sat-ellite-based passive microwave remote sensor, the Advanced Microwave Scanning Radiometer-Earth Observing Sys-tem (AMSR-E) loaded on NASA's (National Aeronautics and Space Administration of USA) Aqua satellite has been popularly used in the field of microwave observation. The Microwave Radiation Imager (MWRI) loaded on the Chi-nese FengYun-3A (FY-3A) satellite is an AMSR-E-like conical scanning microwave sensor, but there are few reports about MWRI data. This paper firstly proposed an optimal spatial position matching algorithm from rough to exact for the position matching between AMSR-E and MWRI data, then taking Northeast China as an example, comparatively analyzed the microwave brightness temperature data derived from AMSR-E and MWRI. The results show that when the antenna footprints of the two sensors are filled with either full water, or full land, or mixed land and water with ap-proximate proportion, the errors of brightness temperature between AMSR-E and MWRI are usually in the range from -10 K to +10 K. In general, the residual values of brightness temperature between the two microwave sensors with the same spatial resolution are in the range of ±3 K. Because the spatial resolution of AMSR-E is three times as high as that of MWRI, the results indicate that the quality of MWRI data is better. The research can provide useful information for the MWRI data application and microwave unmixing method in the future.展开更多
A conventional global contrast enhancement is difficult to apply in various images because image quality and contrast enhancement are dependent on image characteristics largely. And a local contrast enhancement not on...A conventional global contrast enhancement is difficult to apply in various images because image quality and contrast enhancement are dependent on image characteristics largely. And a local contrast enhancement not only causes a washed-out effect, but also blocks. To solve these drawbacks, this paper derives an optimal global equalization function with variable size block based local contrast enhancement. The optimal equalization function makes it possible to get a good quality image through the global contrast enhancement. The variable size block segmentation is firstly exeoated using intensity differences as a measure of similarity. In the second step, the optimal global equalization function is obtained from the enhanced contrast image having variable size blocks. Conformed experiments have showed that the proposed algorithm produces a visually comfortable result image.展开更多
Globalization had changed the competitive landscape in which entrepreneurs used to compete. There are advantages and disadvantages of doing business globally. Globalization had also brought about many challenges to en...Globalization had changed the competitive landscape in which entrepreneurs used to compete. There are advantages and disadvantages of doing business globally. Globalization had also brought about many challenges to entrepreneurs in the management of their organization. The values and beliefs of managers and staff across the globe influence visions, missions of their organization. Culture, resources and business practices of countries vary widely. Entrepreneurs must deal with global issues side by side with domestic considerations. This paper looks into how the theories and model of strategic management remain useful and relevant to entrepreneurs in a globalized business world especially in a turbulent economy.展开更多
To find the optimal operational condition when the properties of feedstock changes in the cracking furnace online,a hybrid algorithm named differential evolution group search optimization(DEGSO) is proposed,which is b...To find the optimal operational condition when the properties of feedstock changes in the cracking furnace online,a hybrid algorithm named differential evolution group search optimization(DEGSO) is proposed,which is based on the differential evolution(DE) and the group search optimization(GSO).The DEGSO combines the advantages of the two algorithms:the high computing speed of DE and the good performance of the GSO for preventing the best particle from converging to local optimum.A cooperative method is also proposed for switching between these two algorithms.If the fitness value of one algorithm keeps invariant in several generations and less than the preset threshold,it is considered to fall into the local optimization and the other algorithm is chosen.Experiments on benchmark functions show that the hybrid algorithm outperforms GSO in accuracy,global searching ability and efficiency.The optimization of ethylene and propylene yields is illustrated as a case by DEGSO.After optimization,the yield of ethylene and propylene is increased remarkably,which provides the proper operational condition of the ethylene cracking furnace.展开更多
Land surface water(LSW) is one of the most important resources for human survival and development, and it is also a main component of global water recycling. A full understanding of the spatial distribution of land su...Land surface water(LSW) is one of the most important resources for human survival and development, and it is also a main component of global water recycling. A full understanding of the spatial distribution of land surface water and a continuous measuring of its dynamics can support to diagnose the global ecosystem and environment. Based on the Global Land 30-water 2000 and Global Land 30-water 2010 products, this research analyzed the spatial distribution pattern and temporal fluctuation of land surface water under scale-levels of global, latitude and longitude, continents, and climate zones. The Global Land 30-water products were corrected the temporal inconsistency of original remotely sensed data using MODIS time-series data, and then calculated the indices such as water area, water ration and coefficient of spatial variation for further analysis. Results show that total water area of land surface is about 3.68 million km2(2010), and occupies 2.73% of land area. The spatial distribution of land surface water is extremely uneven and is gathered mainly in mid- to high-latitude area of the Northern Hemisphere and tropic area. The comparison of water ratio between 2000 and 2010 indicates the overall fluctuation is small but spatially differentiated. The Global Land 30-water products and the statistics provided the fundamental information for analyzing the spatial distribution pattern and temporal fluctuation of land surface water and diagnosing the global ecosystem and environment.展开更多
Under some circumstances surgical resection is feasible in a low percentage for the treatment of deep tumors. Nevertheless, high-intensity focused ultrasound (HIFU) is beginning to offer a potential noninvasive alte...Under some circumstances surgical resection is feasible in a low percentage for the treatment of deep tumors. Nevertheless, high-intensity focused ultrasound (HIFU) is beginning to offer a potential noninvasive alternative to conventional therapies for the treatment of deep tumors. In our previous study, a large scale spherical HIFU-phased array was developed to ablate deep tumors. In the current study, taking into account the required focal depth and maximum acoustic power output, 90 identical circular PZT-8 elements (diameter=1.4 cm and frequency=l MHz) were mounted on a spherical shell with a radius of curvature of 18 cm and a diameter of 21 cm. With the developed array, computer simulations and ex vivo experiments were carried out. The simulation results theoretically demonstrate the ability of the array to focus and steer in the specified volume (a 2 cm×2 cm×3 cm volume) at the focal depth of 15 to 18 cm. Ex vivo experiment results also verify the capability of the developed array to ablate deep target tissue by either moving single focal point or generating multiple foci simultaneously.展开更多
A strong Mw7.0 earthquake struck Pingtung offshore of Talwan on December 26, 2006. It consisted of two major events with an 8-minute interval. The first major shock occurred at 12:26 UTC. Focal mechanism results from...A strong Mw7.0 earthquake struck Pingtung offshore of Talwan on December 26, 2006. It consisted of two major events with an 8-minute interval. The first major shock occurred at 12:26 UTC. Focal mechanism results from Harvard, USGS, and BATS all indicated that the first major shock was a normal fault earthquake and the second one was dominated by strike-slip offsets. The location of the epicenter varied greatly in depth in different analyses. The latest results showed that the focal depth of the first shock was most probably around 40-44 km, placing the epicenter in the lithospheric mantle. However, this is not a location where earthquakes usually occur. To explore the geodynamical mechanism of this event, we carded out 2D finite element method (FEM) numerical experiments. Our primary results indicate that the geodynamical background, as well as the formation of Pingtung earthquake, is a consequence of the collision between Luzon arc and Chinese continental margin. Although Taiwan Island is in the shadow of NW-SE trending compressive collision zone, the existence of ductile lower crust leads to the decoupling between upper crust and lithospheric mantle. As lithospheric mantle subducts to the depth of around 250 km, the upper part of the bending subduction slab puts itself in an extensional state. The extensional stress from bending induced the occurrence of this normal fault earthquake at the critical point.展开更多
文摘Global industrial chains(GICs)have become a hallmark of the world economy underpinning the global production cycle.Since the reform and opening up was introduced in 1978,China has taken an active role in global value chains(GVCs)and become the world’s factory floor.Under the external shocks to GICs,such as US trade frictions with China and the COVID-19 pandemic,China’s traditional comparative advantages in manufacturing which include its labor force and costs are waning.This has manifested in a wave of industrial relocations from China to other countries as well as China’s weakening international competitiveness.We took stock of the concepts and journey of GVCs and elaborated the intrinsic relationship between GVCs and the new development pattern of“dual circulations”.We also analyzed the trends of GVCs,the current status and problems of China’s industrial chains,and China’s market heft,complete industrial chains and the digital economy as new strengths for industrial chain upgrade.In our conclusion,this paper put forth some policy recommendations for China’s industrial chain upgrade in the context of dual circulations.
文摘AIM: To compare small sphincterotomy combined with endoscopic papillary large balloon dilation (SES + ELBD) and endoscopic sphincterotomy (EST) for large bile duct stones. METHODS: We compared prospectively SES + ELBD (group A, n = 27) with conventional EST (group B, n = 28) for the treatment of large bile duct stones (≥ 15 mm). When the stone could not be removed with a normal basket, mechanical lithotripsy was performed. We compared the rates of complete stone removal with one session and application of mechanical lithotripsy. RESULTS: No significant differences were observed in the mean largest stone size (A: 20.8 mm, B: 21.3 mm), bile duct diameter (A: 21.4 turn, B: 20.5 ram), number of stones (A: 2.2, B: 2.3), or procedure time (A: 18 min, B: 19 rain) between the two groups. The rates of complete stone removal with one session was 85% in group A and 86% in group B (P = 0.473). Mechanical lithotripsy was required for stone removal in nine of 27 patients (33%) in group A and nine of 28 patients (32%, P = 0.527) in group B.CONCLUSION: SES + ELBD did not show significant benefits compared to conventional EST, especially for the removal of large (≥ 15 mm) bile duct stones.
基金supported by the National Basic Research Program of China(No.2010CB950501&2010CB950404)the National Natural Science Foundation of China(No.41205058)the China Postdoctoral Sci-ence Foundation(No.2012M510634)
文摘The temporal variability and spatial pattern of the Arctic Oscillation(AO)simulated in the historical experiment of26 coupled climate models participating in the Coupled Model Intercomparison Project Phase 5(CMIP5)are evaluated.Spectral analysis of the monthly AO index indicates that 23 out of the 26 CMIP5 models exhibit no statistically significant spectral peak in the historical experiment,as seen in the observations.These models are able to reproduce the AO pattern in the sea level pressure anomaly field during boreal winter,but the intensity of the AO pattern tends to be overestimated in all the models.The zonal-mean zonal wind anomalies associated with the AO is dominated by a meridional dipole in the mid-high latitudes of the Northern Hemisphere during boreal winter,which is well reproduced by only a few models.Most models show significant biases in both strength and location of the dipole compared to the observation.In considering the temporal variability as well as spatial structures in both horizontal and vertical directions,the MPI-ESM-P model reproduces an AO pattern that resembles the observation the best.
基金Under the auspices of Chinese Postdoctora Slcience Foundations(No .2003034038)
文摘Urban competition refers to capacities of cities for attracting, capturing, controlling, dominating and transforming certain resources during urban development, and capacities for wealth creating, life-standard improving and sustainable development maintenance. This paper first analyzes the external sources of urban competitive advantages: the global network-based advantages and the location-based ones. Then with the aid of method of principal component analysis in SPSS 10.0 for Windows, the Chinese urban global and local competitive advantages are explored. The finding is that the global network-and location-based advantages are remarkable for the cities in the eastern China. While for those in the western and the middle regions, affected by much lower regional competitive advantages and lower degrees of urban-regional integration, the urban competitive advantages are deeply influenced and weakened.
基金supported by Norwegian Council for Higher Education’s Program for Development Research and Education
文摘This study aims to find the altitudinal distribution pattern of vascular plant species reported from high mountain of Nepal(Manang) along the whole Himalayan elevation gradient, and evaluate their fate against climate change. Data was gathered from multiple sources, field investigations, literatures, and herbarium specimens. Altogether, 303 vascular plant species were reported from Manang. We used a published data to calculate distribution range of each species by interpolating between its upper and lower elevation limits. The relationship between elevation and species richness is elucidated by generalized linear model. The consequence of global warming upon Manang's vascular plant species was estimated based on projected temperature change for next century and adiabatic lapse rate along the elevation gradient of the Himalayas. The vascular plant species richness has a unimodel relationship with elevation along the whole elevation gradient of Nepal as well as in three biogeographical regions of Nepal. Vascular plants of Manang are found distributed from low land Terai to high alpine regions of Nepal and their elevation distribution range varies from 200 to 4700 m. Out of 303 vascular plants of Manang, only seven species might be affected if temperature increase by 1.5°C, whereas at least 70 species will be affected with 5°C temperature increased. However, the majority of species(233 species) have wider distribution range(> 1000 m) and more than 5°C temperature tolerance range, thus they are likely to be less affected from global warming by the end of 21 st century.
文摘A large sample size is required for Monte Carlo localization (MCL) in multi-robot dynamic environ- ment, because of the "kidnapped robot" phenomenon, which will locate most of the samples in the regions with small value of desired posterior density. For this problem the crossover and mutation operators in evolutionary computation are introduced into MCL to make samples move towards the regions where the desired posterior density is large, so that the sample set can represent the density better. The proposed method is termed genetic Monte Carlo localization (GMCL). Application in robot soccer system shows that GMCL can considerably reduce the required number of samples, and is more precise and robust in dynamic environment.
文摘Objective: To investigate if intra-aortic balloon pump(IABP) is contraindicated without anticoag-ulation therapy. Methods: Some 153 IABP patients in the King Abdulaziz Cardiac Center(KSA) were random-ly assigned into two groups. Anticoagulation group( Group A) consisted of 71 patients who were given heparin intravenously with target aPTT 50 - 70 seconds. Non-anticoagulation group( Group B) consisted of 82 patients without intravenous heparin during balloon pumping. Hematological parameters including platelet count, D-dimer, Plasminogen activator inhibitor-1 (PAI-1) and fibrinogen degradation products(FDP) were checked respectively at the point of baseline, 24 hours, 48 hours and 24 hours post IABP counterpulsation. Clot deposits on balloon surface, vascular complications from IABP including bleeding and limb ischemia were recorded.Results: Platelet count and PAI-1 level decreased at 24 hours and 48 hours in both groups ( P < 0.05) . D-dimer and FDP level increased at 24 hours and 48 hours in both groups( P < 0.05), but returned to the baseline level 24 hours post IABP removal( P > 0.05) . Three patients in Group A and 2 patients in Group B developed minor limb ischemia( P > 0.05). No major limb ischemia in either group. Two patients in Group A suffered major bleeding and required blood transfusion or surgical intervention, whereas no patient had major bleeding in Group B. Eight patients had minor bleeding in Group A, but only 2 patients in Group B ( P <0.05). No clot deposit developed on IABP surface in either group. Conclusion: IABP is safe without routine anticoagulation therapy. Selecting appropriate artery approach and early detection intervention are key methods for preventing complications.
基金sponsored by the National Basic Research Program of China (Grant No. 2012CB955202)the National Public Benefit (Meteorology) Research Foundation of China (Grant No. GYHY201306018)
文摘In this study, using the Geophysical Fluid Dynamics Laboratory Climate Model version 2pl (GFDL CM2pl) coupled model, the winter predictability barrier (WPB) is found to exist in the model not only in the growing phase but also the Indian Ocean dipole (IOD) decaying phase of positive events due to the effect of initial errors. In particular, the WPB is stronger in the growing phase than in the decaying phase. These results indicate that initial errors can cause the WPB. The domi- nant patterns of the initial errors that cause the occurrence of the WPB often present an eastern-western dipole both in the surface and subsurface temperature components. These initial errors tend to concentrate in a few areas, and these areas may represent the sensitive areas of the predictions of positive IOD events. By increasing observations over these areas and eliminating initial errors here, the WPB phenomenon may be largely weakened and the forecast skill greatly improved.
文摘Due to the superimposed impacts of new industrial revolution,the changing trade policy and the COVID-19 pandemic,the world has seen setbacks in globalization,contractions in the global value chain(GVC),and the risk of a fragmented global system.The once-in-a-century changes in our world today highlight the need for China to explore a new development paradigm based on new concepts.In the new era,China must not only come to terms with a backlash against globalization and challenges from the reshaping of international rules,but also breathe life into the“dual circulations,”i.e.domestic and international economic circulations.China must open up wider to the outside world to keep abreast with changes in today’s global governance system.In the complex and volatile international environment,we should explore new areas of development spearheaded by institutional opening up,create new gateways and platforms for opening up and cooperation for mutual benefit,contribute to new global governance and security systems,and promote synergy between domestic and international circulations.In building a great modern socialist country,China must open up wider and be more inclusive to the outside world.
文摘This study employed an innovative meth- odological framework that combines geomatics and conventional survey methods to monitor changes in forest conditions and examine their associations with local forest governance parameters in a mountain watershed covering 153.3 km2 in the middle moun- tains of Nepal. The study involved two spatial scales and analytical steps. First, geomatics techniques were used to map and detect changes in major land cover types in the watershed between 1976 and 2000 and to analyze relationships between forest cover changes and governance arrangements. This was followed by micro-level analysis of the relationships between the biological conditions of selected forests within the watershed and their governance arrangements, using conventional survey methods and analytical tools. The findings show that forest cover in the watershed in- creased by about 15 per cent during the period. The rate of increase in forest cover was highest in areas under a semi-government type of governance ar- rangement, while the community forests were gener- ally better in terms of current biological conditions compared to the semi-government forests. This in- consistency between the findings from the two analy- ses does not allow us to draw any firm conclusions regarding the role of property rights in determining forest condition, but it indicates that the outcomes of local forest management initiatives may be more de-pendent on local institutional arrangements regulat- ing forest use and maintenance of forest resources than on the type of property rights arrangements. The findings also provide evidence of the methodological suitability of the research approach adopted, which may be useful for addressing many other research questions related to forestry and natural resources management, particularly those involving multiple spatial scales.
基金Supported by the National Natural Science Foundation of China(10571024)
文摘This paper deals with the properties of the solution to a class of nonlocal degenerate reaction-diffusion equation with nonlocal source,subject to the null Dirichlet boundary condition.We first give sufficient conditions for that the solution exists globally or blows up in the finite time.Then the blow-up time is also given.At last,we obtain a property differing from the local source which the blow-up set is the entire interval.
基金Under the auspices of National Natural Science Foundation of China (No. 40971189)Knowledge Innovation Programs of Chinese Academy of Sciences (No. KZCX2-YW-340)China Postdoctoral Science Foundation (No. 20100471276)
文摘With such significant advantages as all-day observation, penetrability and all-weather coverage, passive mi-crowave remote sensing technique has been widely applied in the research of global environmental change. As the sat-ellite-based passive microwave remote sensor, the Advanced Microwave Scanning Radiometer-Earth Observing Sys-tem (AMSR-E) loaded on NASA's (National Aeronautics and Space Administration of USA) Aqua satellite has been popularly used in the field of microwave observation. The Microwave Radiation Imager (MWRI) loaded on the Chi-nese FengYun-3A (FY-3A) satellite is an AMSR-E-like conical scanning microwave sensor, but there are few reports about MWRI data. This paper firstly proposed an optimal spatial position matching algorithm from rough to exact for the position matching between AMSR-E and MWRI data, then taking Northeast China as an example, comparatively analyzed the microwave brightness temperature data derived from AMSR-E and MWRI. The results show that when the antenna footprints of the two sensors are filled with either full water, or full land, or mixed land and water with ap-proximate proportion, the errors of brightness temperature between AMSR-E and MWRI are usually in the range from -10 K to +10 K. In general, the residual values of brightness temperature between the two microwave sensors with the same spatial resolution are in the range of ±3 K. Because the spatial resolution of AMSR-E is three times as high as that of MWRI, the results indicate that the quality of MWRI data is better. The research can provide useful information for the MWRI data application and microwave unmixing method in the future.
文摘A conventional global contrast enhancement is difficult to apply in various images because image quality and contrast enhancement are dependent on image characteristics largely. And a local contrast enhancement not only causes a washed-out effect, but also blocks. To solve these drawbacks, this paper derives an optimal global equalization function with variable size block based local contrast enhancement. The optimal equalization function makes it possible to get a good quality image through the global contrast enhancement. The variable size block segmentation is firstly exeoated using intensity differences as a measure of similarity. In the second step, the optimal global equalization function is obtained from the enhanced contrast image having variable size blocks. Conformed experiments have showed that the proposed algorithm produces a visually comfortable result image.
文摘Globalization had changed the competitive landscape in which entrepreneurs used to compete. There are advantages and disadvantages of doing business globally. Globalization had also brought about many challenges to entrepreneurs in the management of their organization. The values and beliefs of managers and staff across the globe influence visions, missions of their organization. Culture, resources and business practices of countries vary widely. Entrepreneurs must deal with global issues side by side with domestic considerations. This paper looks into how the theories and model of strategic management remain useful and relevant to entrepreneurs in a globalized business world especially in a turbulent economy.
基金Supported by the Major State Basic Research Development Program of China(2012CB720500)the National Natural Science Foundation of China(U1162202),the National Natural Science Foundation of China(61174118)+2 种基金the National High Technology Research and Development Program of China(2012AA040307)Shanghai Key Technologies R&D program(12dz1125100)the Shanghai Leading Academic Discipline Project(B504)
文摘To find the optimal operational condition when the properties of feedstock changes in the cracking furnace online,a hybrid algorithm named differential evolution group search optimization(DEGSO) is proposed,which is based on the differential evolution(DE) and the group search optimization(GSO).The DEGSO combines the advantages of the two algorithms:the high computing speed of DE and the good performance of the GSO for preventing the best particle from converging to local optimum.A cooperative method is also proposed for switching between these two algorithms.If the fitness value of one algorithm keeps invariant in several generations and less than the preset threshold,it is considered to fall into the local optimization and the other algorithm is chosen.Experiments on benchmark functions show that the hybrid algorithm outperforms GSO in accuracy,global searching ability and efficiency.The optimization of ethylene and propylene yields is illustrated as a case by DEGSO.After optimization,the yield of ethylene and propylene is increased remarkably,which provides the proper operational condition of the ethylene cracking furnace.
基金supported by the National High-Tech Research Program of China(Grant Nos.2009AA122001 and 2009AA122004)
文摘Land surface water(LSW) is one of the most important resources for human survival and development, and it is also a main component of global water recycling. A full understanding of the spatial distribution of land surface water and a continuous measuring of its dynamics can support to diagnose the global ecosystem and environment. Based on the Global Land 30-water 2000 and Global Land 30-water 2010 products, this research analyzed the spatial distribution pattern and temporal fluctuation of land surface water under scale-levels of global, latitude and longitude, continents, and climate zones. The Global Land 30-water products were corrected the temporal inconsistency of original remotely sensed data using MODIS time-series data, and then calculated the indices such as water area, water ration and coefficient of spatial variation for further analysis. Results show that total water area of land surface is about 3.68 million km2(2010), and occupies 2.73% of land area. The spatial distribution of land surface water is extremely uneven and is gathered mainly in mid- to high-latitude area of the Northern Hemisphere and tropic area. The comparison of water ratio between 2000 and 2010 indicates the overall fluctuation is small but spatially differentiated. The Global Land 30-water products and the statistics provided the fundamental information for analyzing the spatial distribution pattern and temporal fluctuation of land surface water and diagnosing the global ecosystem and environment.
基金supported by the National Natural Science Foundation of China (No. 30800246)Shanghai Key Technologies R&D Programof China (No. 09441900500)
文摘Under some circumstances surgical resection is feasible in a low percentage for the treatment of deep tumors. Nevertheless, high-intensity focused ultrasound (HIFU) is beginning to offer a potential noninvasive alternative to conventional therapies for the treatment of deep tumors. In our previous study, a large scale spherical HIFU-phased array was developed to ablate deep tumors. In the current study, taking into account the required focal depth and maximum acoustic power output, 90 identical circular PZT-8 elements (diameter=1.4 cm and frequency=l MHz) were mounted on a spherical shell with a radius of curvature of 18 cm and a diameter of 21 cm. With the developed array, computer simulations and ex vivo experiments were carried out. The simulation results theoretically demonstrate the ability of the array to focus and steer in the specified volume (a 2 cm×2 cm×3 cm volume) at the focal depth of 15 to 18 cm. Ex vivo experiment results also verify the capability of the developed array to ablate deep target tissue by either moving single focal point or generating multiple foci simultaneously.
基金supported by National Natural Science Foundation of China (Grant No. 40774048)Major Research of National Natural Science Foundation of China (Grant No. 90814014)Sino-Probe Project of China and Knowledge Innovation Program of Chinese Academy of Sciences (Grant No. KZCX2-YW-123)
文摘A strong Mw7.0 earthquake struck Pingtung offshore of Talwan on December 26, 2006. It consisted of two major events with an 8-minute interval. The first major shock occurred at 12:26 UTC. Focal mechanism results from Harvard, USGS, and BATS all indicated that the first major shock was a normal fault earthquake and the second one was dominated by strike-slip offsets. The location of the epicenter varied greatly in depth in different analyses. The latest results showed that the focal depth of the first shock was most probably around 40-44 km, placing the epicenter in the lithospheric mantle. However, this is not a location where earthquakes usually occur. To explore the geodynamical mechanism of this event, we carded out 2D finite element method (FEM) numerical experiments. Our primary results indicate that the geodynamical background, as well as the formation of Pingtung earthquake, is a consequence of the collision between Luzon arc and Chinese continental margin. Although Taiwan Island is in the shadow of NW-SE trending compressive collision zone, the existence of ductile lower crust leads to the decoupling between upper crust and lithospheric mantle. As lithospheric mantle subducts to the depth of around 250 km, the upper part of the bending subduction slab puts itself in an extensional state. The extensional stress from bending induced the occurrence of this normal fault earthquake at the critical point.