An algorithm to track multiple sharply maneuvering targets without prior knowledge about new target birth is proposed. These targets are capable of achieving sharp maneuvers within a short period of time, such as dron...An algorithm to track multiple sharply maneuvering targets without prior knowledge about new target birth is proposed. These targets are capable of achieving sharp maneuvers within a short period of time, such as drones and agile missiles.The probability hypothesis density (PHD) filter, which propagates only the first-order statistical moment of the full target posterior, has been shown to be a computationally efficient solution to multitarget tracking problems. However, the standard PHD filter operates on the single dynamic model and requires prior information about target birth distribution, which leads to many limitations in terms of practical applications. In this paper,we introduce a nonzero mean, white noise turn rate dynamic model and generalize jump Markov systems to multitarget case to accommodate sharply maneuvering dynamics. Moreover, to adaptively estimate newborn targets’information, a measurement-driven method based on the recursive random sampling consensus (RANSAC) algorithm is proposed. Simulation results demonstrate that the proposed method achieves significant improvement in tracking multiple sharply maneuvering targets with adaptive birth estimation.展开更多
On June 28,2022,Clarivate Analytics released the 2021 SCI Journal Citation Reports(JCR).The SCI impact factor of Petroleum Exploration and Development was 5.194,ranked 1st in all the journals of Petroleum Engineering;...On June 28,2022,Clarivate Analytics released the 2021 SCI Journal Citation Reports(JCR).The SCI impact factor of Petroleum Exploration and Development was 5.194,ranked 1st in all the journals of Petroleum Engineering;and ranked 32nd among the 201 journals in the JCR category of Multidisciplinary Geosciences,up 24 places from the 2020 ranking and entering the Q1 area.The readers have expanded to 127 countries in the world.Paper submissions have been received from authors from 37 countries in Asia,Europe,North America,South America,Africa and Oceania.The international academic influence of the journal has been significantly improved.展开更多
Since the outbreak of the COVID-19,the global economy has fallen into recession,and the lifestyles and consumption ability of residents have undergone important changes.As the country with the largest number of confir...Since the outbreak of the COVID-19,the global economy has fallen into recession,and the lifestyles and consumption ability of residents have undergone important changes.As the country with the largest number of confirmed cases and deaths,the economic downturn and consumption shrinkage are even more serious in the United States.In the second quarter of 2020,U.S.GDP fell by 32.9%year-on-year,the largest drop since records began in 1947.Among them,personal consumption expenditure,which accounts for about 70%of the economy,dropped by 34.6%,the worst performance since the data was recorded.The apparel retail in the United States also suffered heavy losses.In April,it recorded the largest decline of 86.5%year-on-year.Many well-known apparel retail brands such as Brooks Brothers,Ann Taylor,LOFT,J.Crew,etc.have filed for bankruptcy protection and thousands of clothing stores are closed.展开更多
We prove that sharply dominating Archimedean atomic lattice effect algebras can be characterized by the property called basic decomposition of elements.As an application we prove the state smearing theorem for these e...We prove that sharply dominating Archimedean atomic lattice effect algebras can be characterized by the property called basic decomposition of elements.As an application we prove the state smearing theorem for these effect algebras.展开更多
The development of positive and negative streamers in a point-to-plane gap filled with air and nitrogen at various pressures(50-200 kPa)and voltages(8-25 kV)was studied.A four-channel intensified charge-coupled device...The development of positive and negative streamers in a point-to-plane gap filled with air and nitrogen at various pressures(50-200 kPa)and voltages(8-25 kV)was studied.A four-channel intensified charge-coupled device(ICCD)and a streak-camera were used.Electrical parameters were measured with high resolution(10 GHz).An original method of measuring a displacement current caused by a streamer was applied.As was expected,positive streamer branches in nitrogen at low voltages and/or elevated pressures while a large-diameter streamer is formed in air.However,at high voltages or negative polarity,the large-diameter streamer is formed both in nitrogen and air in the entire pressure range.It was found that runaway electrons(REs)are generated in the very first picoseconds of gas ionisation near the pointed cathode.It was assumed that REs can be generated near the pointed anode and produce bremsstrahlung radiation due to a sharply inhomogeneous distribution of electrical potential.It was found that in the final stage of negative streamer development in air and nitrogen,the gas between the streamer front and the opposite electrode is ionised almost simultaneously in the entire volume when the streamer diameter is almost equal to the interelectrode gap.展开更多
<正> In this paper we give the name of automaton to a system ■=(S, ∑) consisting of a set S whose elements are called states, a set ∑ whose elements are called letters, such that for any s∈S and σ∈∑ there...<正> In this paper we give the name of automaton to a system ■=(S, ∑) consisting of a set S whose elements are called states, a set ∑ whose elements are called letters, such that for any s∈S and σ∈∑ there is a state s~σcorresponding to them. Finite sequences of letters in ∑ are called words. (?) is said to展开更多
Against the backdrop of all-time low relations with Asian neighbors, Japan's Emperor Akihito used the occasions of his annual birthday press conference and New Year greeting to talk to his nation about wartime his...Against the backdrop of all-time low relations with Asian neighbors, Japan's Emperor Akihito used the occasions of his annual birthday press conference and New Year greeting to talk to his nation about wartime history. The fact that he rarely addresses展开更多
After a three‐month decline in the China's Mainland market, Passenger vehicle registrations rebounded sharply in October 2008, reaching 532,047 units, a year‐on‐year growth of 21.4%. All body types saw a more t...After a three‐month decline in the China's Mainland market, Passenger vehicle registrations rebounded sharply in October 2008, reaching 532,047 units, a year‐on‐year growth of 21.4%. All body types saw a more than 20% increase compared with the same period last year展开更多
Over time,physical activity(PA)has shifted from being a necessity to being an alternative.As a result,levels of PA have sharply decreased.1 Today,we are facing a worldwide pandemic of physical inactivity,with one deat...Over time,physical activity(PA)has shifted from being a necessity to being an alternative.As a result,levels of PA have sharply decreased.1 Today,we are facing a worldwide pandemic of physical inactivity,with one death every 6 s attributed to insufficient PA.2 To counteract this trend,a tremendous effort is being made to promote regular PA across the lifespan,mainly through the dissemination of knowledge about the health benefits of accumulating sufficient PA.展开更多
The restructuring of global industrial and supply chains is a hot issue in today’s world,and as a result of the once-in-a-century changes and intensified geopolitical and economic competition,the demand for global in...The restructuring of global industrial and supply chains is a hot issue in today’s world,and as a result of the once-in-a-century changes and intensified geopolitical and economic competition,the demand for global industrial and supply chain security has risen sharply,with government departments and transnational corporations(TNCs)becoming the most critical stakeholders.Governments carefully calibrate industrial and trade policies from the perspective of national strategies to create industrial chains that support national competitive advantages,and multinational corporations respond to geopolitical risks by prioritizing industrial and supply chain security and sustainability over capital and efficiency.Against the backdrop of changes unseen in a century,decelerating globalization and global economic downturn,the characteristics and future trends of global industrial and supply chain restructuring are worth paying attention to.展开更多
In 2024,the world economy still faces many uncertainties,and it is likely that the geopolitical economy and global security tensions are likely to continue to intensify;although the global inflation rate is declining,...In 2024,the world economy still faces many uncertainties,and it is likely that the geopolitical economy and global security tensions are likely to continue to intensify;although the global inflation rate is declining,it is still at a high level;the global debt crisis has risen sharply;in particular,the risk of decoupling and chain breakage of the industrial chain and supply chain still exists.展开更多
基金supported by the National Natural Science Foundation of China (61773142)。
文摘An algorithm to track multiple sharply maneuvering targets without prior knowledge about new target birth is proposed. These targets are capable of achieving sharp maneuvers within a short period of time, such as drones and agile missiles.The probability hypothesis density (PHD) filter, which propagates only the first-order statistical moment of the full target posterior, has been shown to be a computationally efficient solution to multitarget tracking problems. However, the standard PHD filter operates on the single dynamic model and requires prior information about target birth distribution, which leads to many limitations in terms of practical applications. In this paper,we introduce a nonzero mean, white noise turn rate dynamic model and generalize jump Markov systems to multitarget case to accommodate sharply maneuvering dynamics. Moreover, to adaptively estimate newborn targets’information, a measurement-driven method based on the recursive random sampling consensus (RANSAC) algorithm is proposed. Simulation results demonstrate that the proposed method achieves significant improvement in tracking multiple sharply maneuvering targets with adaptive birth estimation.
文摘On June 28,2022,Clarivate Analytics released the 2021 SCI Journal Citation Reports(JCR).The SCI impact factor of Petroleum Exploration and Development was 5.194,ranked 1st in all the journals of Petroleum Engineering;and ranked 32nd among the 201 journals in the JCR category of Multidisciplinary Geosciences,up 24 places from the 2020 ranking and entering the Q1 area.The readers have expanded to 127 countries in the world.Paper submissions have been received from authors from 37 countries in Asia,Europe,North America,South America,Africa and Oceania.The international academic influence of the journal has been significantly improved.
文摘Since the outbreak of the COVID-19,the global economy has fallen into recession,and the lifestyles and consumption ability of residents have undergone important changes.As the country with the largest number of confirmed cases and deaths,the economic downturn and consumption shrinkage are even more serious in the United States.In the second quarter of 2020,U.S.GDP fell by 32.9%year-on-year,the largest drop since records began in 1947.Among them,personal consumption expenditure,which accounts for about 70%of the economy,dropped by 34.6%,the worst performance since the data was recorded.The apparel retail in the United States also suffered heavy losses.In April,it recorded the largest decline of 86.5%year-on-year.Many well-known apparel retail brands such as Brooks Brothers,Ann Taylor,LOFT,J.Crew,etc.have filed for bankruptcy protection and thousands of clothing stores are closed.
基金the National Natural Science Foundation of China (Grant Nos.10771191,10471124)the Natural Science Foundation of Zhejiang Province (Grant Nos.M103057,10771191)the Slovak Research and Development Agency under the contracts SK-CN-017-06 and APVV-0071-06
文摘We prove that sharply dominating Archimedean atomic lattice effect algebras can be characterized by the property called basic decomposition of elements.As an application we prove the state smearing theorem for these effect algebras.
基金National Key Research and Development Plan of China,Grant/Award Number:2021YFE0114700Ministry of Science and Higher Education of the Russian Federation,Grant/Award Number:075-15-2021-1026。
文摘The development of positive and negative streamers in a point-to-plane gap filled with air and nitrogen at various pressures(50-200 kPa)and voltages(8-25 kV)was studied.A four-channel intensified charge-coupled device(ICCD)and a streak-camera were used.Electrical parameters were measured with high resolution(10 GHz).An original method of measuring a displacement current caused by a streamer was applied.As was expected,positive streamer branches in nitrogen at low voltages and/or elevated pressures while a large-diameter streamer is formed in air.However,at high voltages or negative polarity,the large-diameter streamer is formed both in nitrogen and air in the entire pressure range.It was found that runaway electrons(REs)are generated in the very first picoseconds of gas ionisation near the pointed cathode.It was assumed that REs can be generated near the pointed anode and produce bremsstrahlung radiation due to a sharply inhomogeneous distribution of electrical potential.It was found that in the final stage of negative streamer development in air and nitrogen,the gas between the streamer front and the opposite electrode is ionised almost simultaneously in the entire volume when the streamer diameter is almost equal to the interelectrode gap.
文摘<正> In this paper we give the name of automaton to a system ■=(S, ∑) consisting of a set S whose elements are called states, a set ∑ whose elements are called letters, such that for any s∈S and σ∈∑ there is a state s~σcorresponding to them. Finite sequences of letters in ∑ are called words. (?) is said to
文摘Against the backdrop of all-time low relations with Asian neighbors, Japan's Emperor Akihito used the occasions of his annual birthday press conference and New Year greeting to talk to his nation about wartime history. The fact that he rarely addresses
文摘After a three‐month decline in the China's Mainland market, Passenger vehicle registrations rebounded sharply in October 2008, reaching 532,047 units, a year‐on‐year growth of 21.4%. All body types saw a more than 20% increase compared with the same period last year
基金We would like to thank individuals for their participation in our online survey as well as the study authors who responded to our data requests.This work was supported by the Economic and Social Research Council(ES/P000738/1)the Medical Research Council(MC_UU_00006/5)the University of Cambridge,and the National Health and Medical Research Council(GS2000053).The funders had no role in designing the study,analyzing the data,or writing the manuscript.
文摘Over time,physical activity(PA)has shifted from being a necessity to being an alternative.As a result,levels of PA have sharply decreased.1 Today,we are facing a worldwide pandemic of physical inactivity,with one death every 6 s attributed to insufficient PA.2 To counteract this trend,a tremendous effort is being made to promote regular PA across the lifespan,mainly through the dissemination of knowledge about the health benefits of accumulating sufficient PA.
文摘The restructuring of global industrial and supply chains is a hot issue in today’s world,and as a result of the once-in-a-century changes and intensified geopolitical and economic competition,the demand for global industrial and supply chain security has risen sharply,with government departments and transnational corporations(TNCs)becoming the most critical stakeholders.Governments carefully calibrate industrial and trade policies from the perspective of national strategies to create industrial chains that support national competitive advantages,and multinational corporations respond to geopolitical risks by prioritizing industrial and supply chain security and sustainability over capital and efficiency.Against the backdrop of changes unseen in a century,decelerating globalization and global economic downturn,the characteristics and future trends of global industrial and supply chain restructuring are worth paying attention to.
文摘In 2024,the world economy still faces many uncertainties,and it is likely that the geopolitical economy and global security tensions are likely to continue to intensify;although the global inflation rate is declining,it is still at a high level;the global debt crisis has risen sharply;in particular,the risk of decoupling and chain breakage of the industrial chain and supply chain still exists.
