To explain the long-term existence of Uranian narrow rings, we study the dynamical evolution of Uranian epsilon ring under the influence of its two shepherding satellites: Cordelia and Ophelia. The model of planar-ell...To explain the long-term existence of Uranian narrow rings, we study the dynamical evolution of Uranian epsilon ring under the influence of its two shepherding satellites: Cordelia and Ophelia. The model of planar-elliptic restricted three-body problem is employed, in which the three bodies are Uranus, a satellite and a test particle. Dissipations due to interparticle collisions are also taken into consideration. A mapping system has been obtained based on the differential equation system. Numerical results show that only those particles originally lying in the libration region of the resonance can be shepherded. The size of the libration region depends mainly on the orbital eccentricity and mass of the shepherd satellite. For the outer shepherd Ophelia with larger orbital eccentricity, if its mass is a third of the nominal mass 2.5 × 1019 g, most of the orbits are regular and the outer edge of the ring can be shepherded, but more fuzzy than the inner edge. Thus we infer that Ophelia has a smaller mass.展开更多
Swarming behaviors play an eminent role in both biological and engineering research, and show great potential applications in many emerging fields. Traditional swarming models still lack integrity, uniformity, and sta...Swarming behaviors play an eminent role in both biological and engineering research, and show great potential applications in many emerging fields. Traditional swarming models still lack integrity, uniformity, and stability in swarm forming processes,resulting in fragmentation and void phenomena. Inspired by the shepherding behaviors observed in nature, we propose an integrated negotiation-control scheme for distributed swarm control of massive robots. The core idea of this scheme is that the robots at the boundary of the group herd the internal robots to form an equilibrium swarm. For this purpose, we introduce a concept of virtual group center towards which boundary robots herd internal robots. Then, a distributed negotiation mechanism is designed to allow each robot to negotiate the virtual group center only through local interactions with its neighbors. After that, we propose a shepherding-inspired swarm control law to drive a group of robots to form an integrated, uniform, and stable configuration from any initial states. Both numerical and flight simulations are presented to verify the effectiveness of our proposed swarm control scheme.展开更多
Transparency is a widely used but poorly defined term within the explainable artificial intelligence literature.This is due,in part,to the lack of an agreed definition and the overlap between the connected—sometimes ...Transparency is a widely used but poorly defined term within the explainable artificial intelligence literature.This is due,in part,to the lack of an agreed definition and the overlap between the connected—sometimes used synonymously—concepts of interpretability and explainability.We assert that transparency is the overarching concept,with the tenets of interpretability,explainability,and predictability subordinate.We draw on a portfolio of definitions for each of these distinct concepts to propose a human-swarm-teaming transparency and trust architecture(HST3-Architecture).The architecture reinforces transparency as a key contributor towards situation awareness,and consequently as an enabler for effective trustworthy human-swarm teaming(HST).展开更多
Shepherd＇s purse seeds were collected from winter wheat fields and road sides in Hebei Province,China.Their sensitivities to tribenuron-methyl were evaluated in a whole plant dose response assay in the greenhouse.Res...Shepherd＇s purse seeds were collected from winter wheat fields and road sides in Hebei Province,China.Their sensitivities to tribenuron-methyl were evaluated in a whole plant dose response assay in the greenhouse.Results revealed that HB-1,HB-2,HB-3,HB-4,HB-6,HB-7,HB-17,HB-18,HB-19,HB-20,HB-21,and HB-22 populations were susceptible to tribenuron-methyl characterised by very low GR50 values of about 0.10 g a.i.ha-1.On the other hand,populations HB-15 and HB-16 had moderate resistance to tribenuron-methyl with resistance indices （RI） ranging from 10-100 folds,whilst populations HB-5,HB-8,HB-9,HB-10,HB-11,HB-12,HB-13,and HB-14 expressed high level of resistance to tribenuron-methyl with resistance indices over 100.The proportion of moderate resistance level was about 9.09%,and that of high resistance was about 36.36%.展开更多
BACKGROUND Surgical correction of femoral deformities in polyostotic fibrous dysplasia(PFD)or McCune-Albright syndrome(MAS),such as coxa vara or shepherd’s crook deformity,is a challenge.AIM To evaluate the treatment...BACKGROUND Surgical correction of femoral deformities in polyostotic fibrous dysplasia(PFD)or McCune-Albright syndrome(MAS),such as coxa vara or shepherd’s crook deformity,is a challenge.AIM To evaluate the treatment of patients with femoral deformities caused by PDF or MAS treated by osteotomies and stabilized with different methods,by analyzing the most relevant studies on the topic.METHODS A literature search was performed in Medline database(PubMed).Articles were screened for patients affected by PFD or MAS surgically managed by osteotomies and stabilized with different methods.RESULTS The initial search produced 184 studies,with 15 fulfilling the eligibility criteria of our study.Selected articles(1987-2019)included 111 patients overall(136 femurs).CONCLUSION Based on our results,the preferred method to stabilize corrective osteotomies is intramedullary nailing with neck cross pinning.When the deformity is limited to the proximal part of the femur,a screw or blade plate may be used,although there is a high risk of fracture below the plate.When the femur is entirely involved,a two-stage procedure may be considered.展开更多
Dogs were the first animal to become domesticated by humans,and they represent a classic model system for unraveling the processes of domestication.We compare Australian dingo eye contact and socialization with Basenj...Dogs were the first animal to become domesticated by humans,and they represent a classic model system for unraveling the processes of domestication.We compare Australian dingo eye contact and socialization with Basenji and German Shepherd dog(GSD)breeds.Australian dingoes arrived in Australia 5,000–8,000 BP,and there is debate whether they were domesticated before their arrival.The Basenji represents a primitive breed that diverged from the remaining breeds early in the domestication process,while GSDs are a breed dog selected from existing domestic dogs in the late 1800s.We conducted a 4-phase study with unfamiliar and familiar investigators either sitting passively or actively calling each canid.We found 75%of dingoes made eye contact in each phase.In contrast,86%of Basenjis and 96%of GSDs made eye contact.Dingoes also exhibited shorter eye-gaze duration than breed dogs and did not respond to their name being called actively.Sociability,quantified as a canid coming within 1m of the experimenter,was lowest for dingoes and highest for GSDs.For sociability duration,dingoes spent less time within 1m of the experimenter than either breed dog.When compared with previous studies,these data show that the dingo is behaviorally intermediate between wild wolves and Basenji dogs and suggest that it was not domesticated before it arrived in Australia.However,it remains possible that the accumulation of mutations since colonization has obscured historical behaviors,and dingoes now exist in a feralized retamed cycle.Additional morphological and genetic data are required to resolve this conundrum.展开更多
Dogs are used for centuries as people helpers. One of possible use is a sport and service. BSM （Belgian Shepherd Malinois） and GS （German shepherd） dogs are most used breeds like service dogs and also most represe...Dogs are used for centuries as people helpers. One of possible use is a sport and service. BSM （Belgian Shepherd Malinois） and GS （German shepherd） dogs are most used breeds like service dogs and also most represented at sports competitions. Our aim was to compare the results of these breeds in the World Cup of International tests of working dogs （in years 2003-2011）, which is the peak of competitions. The authors evaluated results of German shepherd dog performance test and Belgian shepherd Malinois performance in disciplines such as tracking, obedience and defense. Belgian Shepherds achieved in all disciplines higher score than German shepherds. It was found out that Belgian shepherd Malinois get significant higher score in all disciplines （tracking, obedience and defense） than German shepherd. However, both of breeds are used successfully as service dogs.展开更多
文摘To explain the long-term existence of Uranian narrow rings, we study the dynamical evolution of Uranian epsilon ring under the influence of its two shepherding satellites: Cordelia and Ophelia. The model of planar-elliptic restricted three-body problem is employed, in which the three bodies are Uranus, a satellite and a test particle. Dissipations due to interparticle collisions are also taken into consideration. A mapping system has been obtained based on the differential equation system. Numerical results show that only those particles originally lying in the libration region of the resonance can be shepherded. The size of the libration region depends mainly on the orbital eccentricity and mass of the shepherd satellite. For the outer shepherd Ophelia with larger orbital eccentricity, if its mass is a third of the nominal mass 2.5 × 1019 g, most of the orbits are regular and the outer edge of the ring can be shepherded, but more fuzzy than the inner edge. Thus we infer that Ophelia has a smaller mass.
基金supported by the National Key R&D Program of China (Grant No. 2022YFB3305600)the National Natural Science Foundation of China (Grant Nos. 62103015 and 62141604)+1 种基金the China Postdoctoral Science Foundation (Grant No. 2023M740185)the Postdoctoral Fellows of Beihang “Zhuoyue” Program。
文摘Swarming behaviors play an eminent role in both biological and engineering research, and show great potential applications in many emerging fields. Traditional swarming models still lack integrity, uniformity, and stability in swarm forming processes,resulting in fragmentation and void phenomena. Inspired by the shepherding behaviors observed in nature, we propose an integrated negotiation-control scheme for distributed swarm control of massive robots. The core idea of this scheme is that the robots at the boundary of the group herd the internal robots to form an equilibrium swarm. For this purpose, we introduce a concept of virtual group center towards which boundary robots herd internal robots. Then, a distributed negotiation mechanism is designed to allow each robot to negotiate the virtual group center only through local interactions with its neighbors. After that, we propose a shepherding-inspired swarm control law to drive a group of robots to form an integrated, uniform, and stable configuration from any initial states. Both numerical and flight simulations are presented to verify the effectiveness of our proposed swarm control scheme.
基金United States Office of Naval Research-Global(ONR-G)(N629091812140)。
文摘Transparency is a widely used but poorly defined term within the explainable artificial intelligence literature.This is due,in part,to the lack of an agreed definition and the overlap between the connected—sometimes used synonymously—concepts of interpretability and explainability.We assert that transparency is the overarching concept,with the tenets of interpretability,explainability,and predictability subordinate.We draw on a portfolio of definitions for each of these distinct concepts to propose a human-swarm-teaming transparency and trust architecture(HST3-Architecture).The architecture reinforces transparency as a key contributor towards situation awareness,and consequently as an enabler for effective trustworthy human-swarm teaming(HST).
基金supported by the State Key Laboratory for Biology of Plant Diseases and Insect Pests,Institute of Plant Protection (IPP),Chinese Academy of Agricultural Sciences,China (SKL2010OP15)the National Natural Science Foundation of China (31000856)
文摘Shepherd＇s purse seeds were collected from winter wheat fields and road sides in Hebei Province,China.Their sensitivities to tribenuron-methyl were evaluated in a whole plant dose response assay in the greenhouse.Results revealed that HB-1,HB-2,HB-3,HB-4,HB-6,HB-7,HB-17,HB-18,HB-19,HB-20,HB-21,and HB-22 populations were susceptible to tribenuron-methyl characterised by very low GR50 values of about 0.10 g a.i.ha-1.On the other hand,populations HB-15 and HB-16 had moderate resistance to tribenuron-methyl with resistance indices （RI） ranging from 10-100 folds,whilst populations HB-5,HB-8,HB-9,HB-10,HB-11,HB-12,HB-13,and HB-14 expressed high level of resistance to tribenuron-methyl with resistance indices over 100.The proportion of moderate resistance level was about 9.09%,and that of high resistance was about 36.36%.
文摘BACKGROUND Surgical correction of femoral deformities in polyostotic fibrous dysplasia(PFD)or McCune-Albright syndrome(MAS),such as coxa vara or shepherd’s crook deformity,is a challenge.AIM To evaluate the treatment of patients with femoral deformities caused by PDF or MAS treated by osteotomies and stabilized with different methods,by analyzing the most relevant studies on the topic.METHODS A literature search was performed in Medline database(PubMed).Articles were screened for patients affected by PFD or MAS surgically managed by osteotomies and stabilized with different methods.RESULTS The initial search produced 184 studies,with 15 fulfilling the eligibility criteria of our study.Selected articles(1987-2019)included 111 patients overall(136 femurs).CONCLUSION Based on our results,the preferred method to stabilize corrective osteotomies is intramedullary nailing with neck cross pinning.When the deformity is limited to the proximal part of the femur,a screw or blade plate may be used,although there is a high risk of fracture below the plate.When the femur is entirely involved,a two-stage procedure may be considered.
基金supported by Australian Research Council Discover Project 150102038.
文摘Dogs were the first animal to become domesticated by humans,and they represent a classic model system for unraveling the processes of domestication.We compare Australian dingo eye contact and socialization with Basenji and German Shepherd dog(GSD)breeds.Australian dingoes arrived in Australia 5,000–8,000 BP,and there is debate whether they were domesticated before their arrival.The Basenji represents a primitive breed that diverged from the remaining breeds early in the domestication process,while GSDs are a breed dog selected from existing domestic dogs in the late 1800s.We conducted a 4-phase study with unfamiliar and familiar investigators either sitting passively or actively calling each canid.We found 75%of dingoes made eye contact in each phase.In contrast,86%of Basenjis and 96%of GSDs made eye contact.Dingoes also exhibited shorter eye-gaze duration than breed dogs and did not respond to their name being called actively.Sociability,quantified as a canid coming within 1m of the experimenter,was lowest for dingoes and highest for GSDs.For sociability duration,dingoes spent less time within 1m of the experimenter than either breed dog.When compared with previous studies,these data show that the dingo is behaviorally intermediate between wild wolves and Basenji dogs and suggest that it was not domesticated before it arrived in Australia.However,it remains possible that the accumulation of mutations since colonization has obscured historical behaviors,and dingoes now exist in a feralized retamed cycle.Additional morphological and genetic data are required to resolve this conundrum.
文摘Dogs are used for centuries as people helpers. One of possible use is a sport and service. BSM （Belgian Shepherd Malinois） and GS （German shepherd） dogs are most used breeds like service dogs and also most represented at sports competitions. Our aim was to compare the results of these breeds in the World Cup of International tests of working dogs （in years 2003-2011）, which is the peak of competitions. The authors evaluated results of German shepherd dog performance test and Belgian shepherd Malinois performance in disciplines such as tracking, obedience and defense. Belgian Shepherds achieved in all disciplines higher score than German shepherds. It was found out that Belgian shepherd Malinois get significant higher score in all disciplines （tracking, obedience and defense） than German shepherd. However, both of breeds are used successfully as service dogs.
