Path planning in changing environments with difficult regions, such as narrow passages and obstacle boundaries, creates significant chal- lenges. As the obstacles in W-space move frequently, the crowd degree of C-spac...Path planning in changing environments with difficult regions, such as narrow passages and obstacle boundaries, creates significant chal- lenges. As the obstacles in W-space move frequently, the crowd degree of C-space changes accordingly. Therefore, in order to dynamically improve the sampling quality, it is appreciated for a planner to rapidly approximate the crowd degree of different parts of the C-space, and boost sample densities with them based on their difficulty levels. In this paper, a novel approach called Adaptive Region Boosting （ARB） is proposed to increase the sampling density for difficult areas with different strategies. What＇s more, a new criterion, called biased entropy, is proposed to evaluate the difficult degree of a region. The new criterion takes into account both temporal and spatial information of a specific C-space region, in order to make a thorough assessment to a local area. Three groups of experiments are conducted based on a dual-manipulator system with 12 DoFs. Experimental results indicate that ARB effectively improves the success rate and outperforms all the other related methods in various dynamical scenarios.展开更多
Colonoscopy sometimes causes pain during insertion,especially in difficult cases.Over-insufflation of air causes elongation or acute angulations of the colon,making passage of the scope difficult and causing pain.We p...Colonoscopy sometimes causes pain during insertion,especially in difficult cases.Over-insufflation of air causes elongation or acute angulations of the colon,making passage of the scope difficult and causing pain.We previously reported a sedative-risk-free colonoscopy insertion technique,namely,"Water Navigation Colonoscopy".Complete air suction after water infusion not only improves the vision,but also makes water flow down to the descending colon,while the sigmoid colon collapses and shortens.While non-sedative colonoscopy can be carried out without pain in most cases,some patients do complain of pain.Most of these patients have abnormal colon morphology,and the pain is caused while negotiating the "hairpin" bends of the colon.The "hairpin" bends of the colon should be negotiated by gently pushing the full-angled colonoscope.The proximal 10-20 cm from the angulated part of the conventional colonoscope is stiff,with a wide turning radius,therefore,a conventional colonoscope cannot be negotiated through the "hairpin" bends of the colon without stretching them and causing pain.The "passive-bending colonoscope" has a flexible tip with a narrow turning radius,so that the scope can be negotiated through the "hairpin" bends of the colon with a minimum turning radius and minimal discomfort.Therefore,the intubation and pain-reducing performance of the "passive-bending colonoscope" was assessed in difficult cases.展开更多
Marked by the UN Climate Change Conference in Copenhagen 2009, climate change is shaping the new pattern for future geopolitics with unprecedented drive. Climate change has surpassed the category of pure environment p...Marked by the UN Climate Change Conference in Copenhagen 2009, climate change is shaping the new pattern for future geopolitics with unprecedented drive. Climate change has surpassed the category of pure environment problem and become a focal issue in international relations. Driven by climate change, new changes have taken place in the evolution of geopolitical pattern. (1) Geopolitical contention expands into new fields and regions. (2) Measures and tools of geopolitical contention become more diversified. (3) Main bodies of geopolitical gambling are divided into different groups. With the development of politicization, climate change has become the significant driving force that can influence the evolution of geopolitical pattern. Measures, sphere and contents of geopolitical contention changed dramatically, carbon emission permits, carbon tariff and new energy technology turned into the key points of geopolitical contention. Climate change acts on the evolution of geopolitical pattern through three main paths: "Feedback effect", "Trace back effect", and "Ripple effect", and they exert influence on geopolitical pattern with three impacts: "Depression effect", "Traceability effect", and "Diffusion effect". We draw several conclusions from the analysis: (1) Climate change gradually becomes one of the most active driving forces to impact on the evolution of geopolitical pattern in the present world and it diversifies the geopolitical targets. (2) Climate change generates new geopolitical tools. The developed countries use climate change as a "Lever" to pry strategic resources like energy and grain and the geopolitical means are in a more secretive way. (3) Low-carbon technology, with new energy technology as the core, becomes the key factor of geopolitical influence and power transition. Those who can take advantage of new energy technologies will occupy the leading position in future's climate change negotiations and geopolitical competition.展开更多
文摘Path planning in changing environments with difficult regions, such as narrow passages and obstacle boundaries, creates significant chal- lenges. As the obstacles in W-space move frequently, the crowd degree of C-space changes accordingly. Therefore, in order to dynamically improve the sampling quality, it is appreciated for a planner to rapidly approximate the crowd degree of different parts of the C-space, and boost sample densities with them based on their difficulty levels. In this paper, a novel approach called Adaptive Region Boosting （ARB） is proposed to increase the sampling density for difficult areas with different strategies. What＇s more, a new criterion, called biased entropy, is proposed to evaluate the difficult degree of a region. The new criterion takes into account both temporal and spatial information of a specific C-space region, in order to make a thorough assessment to a local area. Three groups of experiments are conducted based on a dual-manipulator system with 12 DoFs. Experimental results indicate that ARB effectively improves the success rate and outperforms all the other related methods in various dynamical scenarios.
文摘Colonoscopy sometimes causes pain during insertion,especially in difficult cases.Over-insufflation of air causes elongation or acute angulations of the colon,making passage of the scope difficult and causing pain.We previously reported a sedative-risk-free colonoscopy insertion technique,namely,"Water Navigation Colonoscopy".Complete air suction after water infusion not only improves the vision,but also makes water flow down to the descending colon,while the sigmoid colon collapses and shortens.While non-sedative colonoscopy can be carried out without pain in most cases,some patients do complain of pain.Most of these patients have abnormal colon morphology,and the pain is caused while negotiating the "hairpin" bends of the colon.The "hairpin" bends of the colon should be negotiated by gently pushing the full-angled colonoscope.The proximal 10-20 cm from the angulated part of the conventional colonoscope is stiff,with a wide turning radius,therefore,a conventional colonoscope cannot be negotiated through the "hairpin" bends of the colon without stretching them and causing pain.The "passive-bending colonoscope" has a flexible tip with a narrow turning radius,so that the scope can be negotiated through the "hairpin" bends of the colon with a minimum turning radius and minimal discomfort.Therefore,the intubation and pain-reducing performance of the "passive-bending colonoscope" was assessed in difficult cases.
基金National Natural Science Foundation of China, No.41171110Strategic Priority Research Program-Climate Change: Carbon Budget and Related Issues of the CAS,No.XDA05010205
文摘Marked by the UN Climate Change Conference in Copenhagen 2009, climate change is shaping the new pattern for future geopolitics with unprecedented drive. Climate change has surpassed the category of pure environment problem and become a focal issue in international relations. Driven by climate change, new changes have taken place in the evolution of geopolitical pattern. (1) Geopolitical contention expands into new fields and regions. (2) Measures and tools of geopolitical contention become more diversified. (3) Main bodies of geopolitical gambling are divided into different groups. With the development of politicization, climate change has become the significant driving force that can influence the evolution of geopolitical pattern. Measures, sphere and contents of geopolitical contention changed dramatically, carbon emission permits, carbon tariff and new energy technology turned into the key points of geopolitical contention. Climate change acts on the evolution of geopolitical pattern through three main paths: "Feedback effect", "Trace back effect", and "Ripple effect", and they exert influence on geopolitical pattern with three impacts: "Depression effect", "Traceability effect", and "Diffusion effect". We draw several conclusions from the analysis: (1) Climate change gradually becomes one of the most active driving forces to impact on the evolution of geopolitical pattern in the present world and it diversifies the geopolitical targets. (2) Climate change generates new geopolitical tools. The developed countries use climate change as a "Lever" to pry strategic resources like energy and grain and the geopolitical means are in a more secretive way. (3) Low-carbon technology, with new energy technology as the core, becomes the key factor of geopolitical influence and power transition. Those who can take advantage of new energy technologies will occupy the leading position in future's climate change negotiations and geopolitical competition.
