Drone also known as unmanned aerial vehicle(UAV)has drawn lots of attention in recent years.Quadcopter as one of the most popular drones has great potential in both industrial and academic fields.Quadcopter drones are...Drone also known as unmanned aerial vehicle(UAV)has drawn lots of attention in recent years.Quadcopter as one of the most popular drones has great potential in both industrial and academic fields.Quadcopter drones are capable of taking off vertically and flying towards any direction.Traditional researches of drones mainly focus on their mechanical structures and movement control.The aircraft movement is usually controlled by a remote controller manually or the trajectory is pre-programmed with specific algorithms.Consumer drones typically use mobile device together with remote controllers to realize flight control and video transmission.Implementing different functions on mobile devices can result in different behaviors of drones indirectly.With the development of deep learning in computer vision field,commercial drones equipped with camera can be much more intelligent and even realize autonomous flight.In the past,running deep learning based algorithms on mobile devices is highly computational intensive and time consuming.This paper utilizes a novel real-time object detection method and deploys the deep learning model on the modern mobile device to realize autonomous object detection and object tracking of drones.展开更多
Achieving mobile liquid droplets on solid surfaces is crucial for various practical applications,such as self-cleaning and anti-fouling coatings.The last two decades have witnessed remarkable progress in designing fun...Achieving mobile liquid droplets on solid surfaces is crucial for various practical applications,such as self-cleaning and anti-fouling coatings.The last two decades have witnessed remarkable progress in designing functional surfaces,including superrepellent surfaces and lubricant-infused surfaces,which allow droplets to roll/slide on the surfaces.However,it remains a challenge to enable droplet motion on hydrophilic solid surfaces.In this work,we demonstrate mobile droplets containing ionic surfactants on smooth hydrophilic surfaces that are charged similarly to surfactant molecules.The ionic surfactant-laden droplets display ultra-low contact angle and ultra-low sliding angle simultaneously on the hydrophilic surfaces.The sliding of the droplet is enabled by the adsorbed surfactant ahead of three-phase contact line,which is regulated by the electrostatic interaction between ionic surfactant and charged solid surface.The droplet can maintain its motion even when the hydrophilic surface has defects.Furthermore,we demonstrate controlled manipulation of ionic surfactantladen droplets on hydrophilic surfaces with different patterns.We envision that our simple technique for achieving mobile droplets on hydrophilic surfaces can pave the way to novel slippery surfaces for different applications.展开更多
BACKGROUND Children with critical acute abdominal conditions often undergo intestinal stoma surgery.AIM To explore the impact of a visual mobile terminal-based extended care model on caregiver competence for children ...BACKGROUND Children with critical acute abdominal conditions often undergo intestinal stoma surgery.AIM To explore the impact of a visual mobile terminal-based extended care model on caregiver competence for children with enterostomies.METHODS One hundred twenty children with enterostomies and their caregivers in a children's hospital in Beijing were divided into a control group and a study group.The control group(60 cases)received traditional telephone follow-up for continuity of care,while the study group(60 cases)used a visualization mobile terminal-based care model.The incidence of stoma-related complications,caregiver burden scale,and competence scores of children with stoma were compared between the two groups.RESULTS The primary caregiver burden score in the study group(37.22±3.17)was significantly lower than that in the control group(80.00±4.47),and the difference was statistically significant(P<0.05).Additionally,the caregiving ability score of the study group(172.08±3.49)was significantly higher than that of the control group(117.55±4.28;P<0.05).The total incidence of complications in the study group(11.7%,7/60)was significantly lower compared to the control group(33.3%,20/60;χ2=8.086,P=0.004).CONCLUSION The visual mobile terminal-based care model reduces caregiver burden,improves home care ability,lowers the incidence of complications and readmission rates,and supports successful second-stage reduction surgery for children with enterostomies.展开更多
During the process of urbanization,community environments encounter challenges such as data disconnection and the underutilization of small and micro spaces.The establishment of“complete communities”necessitates the...During the process of urbanization,community environments encounter challenges such as data disconnection and the underutilization of small and micro spaces.The establishment of“complete communities”necessitates the implementation of refined governance strategies.This research develops a path for the precise establishment of community micro-gardens driven by mobile measurement.It involves the collection of environmental data via mobile devices equipped with various types of sensors,the generation of visualization maps that are adjusted for spatio-temporal synchronization,and the identification of environmental paint points,including areas of excessive temperature exposure and zones with elevated noise levels.Based on the aforementioned considerations,various plant allocation strategies have been proposed for distinct areas.For instance,the implementation of a composite shade and cooling vegetation system is recommended for regions experiencing high temperatures,while a triple protection structure is suggested for areas affected by odor contamination.The efficacy of these strategies is demonstrated through a case study of the micro-garden transformation in the Dongjie Community of Wulituo Street,Shijingshan,Beijing.The study presents operational technical pathways and plant response solutions aimed at facilitating data-driven governance of community micro-environments.展开更多
At present,energy consumption is one of the main bottlenecks in autonomous mobile robot development.To address the challenge of high energy consumption in path planning for autonomous mobile robots navigating unknown ...At present,energy consumption is one of the main bottlenecks in autonomous mobile robot development.To address the challenge of high energy consumption in path planning for autonomous mobile robots navigating unknown and complex environments,this paper proposes an Attention-Enhanced Dueling Deep Q-Network(ADDueling DQN),which integrates a multi-head attention mechanism and a prioritized experience replay strategy into a Dueling-DQN reinforcement learning framework.A multi-objective reward function,centered on energy efficiency,is designed to comprehensively consider path length,terrain slope,motion smoothness,and obstacle avoidance,enabling optimal low-energy trajectory generation in 3D space from the source.The incorporation of a multihead attention mechanism allows the model to dynamically focus on energy-critical state features—such as slope gradients and obstacle density—thereby significantly improving its ability to recognize and avoid energy-intensive paths.Additionally,the prioritized experience replay mechanism accelerates learning from key decision-making experiences,suppressing inefficient exploration and guiding the policy toward low-energy solutions more rapidly.The effectiveness of the proposed path planning algorithm is validated through simulation experiments conducted in multiple off-road scenarios.Results demonstrate that AD-Dueling DQN consistently achieves the lowest average energy consumption across all tested environments.Moreover,the proposed method exhibits faster convergence and greater training stability compared to baseline algorithms,highlighting its global optimization capability under energy-aware objectives in complex terrains.This study offers an efficient and scalable intelligent control strategy for the development of energy-conscious autonomous navigation systems.展开更多
Open Mobile API是基于Android平台的用于手机应用程序访问安全模块的规范.通过分析目前国内移动近场支付业务情况,指出SIM Alliance组织推出该接口规范的背景和原因,论述其架构、功能和设计实现,并举例说明Open Mobile API在移动支付...Open Mobile API是基于Android平台的用于手机应用程序访问安全模块的规范.通过分析目前国内移动近场支付业务情况,指出SIM Alliance组织推出该接口规范的背景和原因,论述其架构、功能和设计实现,并举例说明Open Mobile API在移动支付中的应用.展开更多
In order to save the energy and reduce the latency of the end-to-end transmission in mobile ad hoc networks an adaptive and distance-driven power control ADPC scheme is proposed by means of distance research in random...In order to save the energy and reduce the latency of the end-to-end transmission in mobile ad hoc networks an adaptive and distance-driven power control ADPC scheme is proposed by means of distance research in random geometrics. Through mathematical proof the optimal number of relay nodes and the optimal location of each node for data transmission can be obtained when a distance is given.In the ADPC first the source node computes the optimal number and the sites of the relay nodes between the source and the destination nodes.Then it searches feasible relay nodes around the optimal virtual relay-sites and selects one link with the minimal total transmission energy consumption for data transmission.Simulation results show that the ADPC can reduce both the energy dissipation and the end-to-end latency of the transmission.展开更多
During the past few decades,mobile wireless communications have experienced four generations of technological revolution,namely from 1 G to 4 G,and the deployment of the latest 5 G networks is expected to take place i...During the past few decades,mobile wireless communications have experienced four generations of technological revolution,namely from 1 G to 4 G,and the deployment of the latest 5 G networks is expected to take place in 2019.One fundamental question is how we can push forward the development of mobile wireless communications while it has become an extremely complex and sophisticated system.We believe that the answer lies in the huge volumes of data produced by the network itself,and machine learning may become a key to exploit such information.In this paper,we elaborate why the conventional model-based paradigm,which has been widely proved useful in pre-5 G networks,can be less efficient or even less practical in the future 5 G and beyond mobile networks.Then,we explain how the data-driven paradigm,using state-of-the-art machine learning techniques,can become a promising solution.At last,we provide a typical use case of the data-driven paradigm,i.e.,proactive load balancing,in which online learning is utilized to adjust cell configurations in advance to avoid burst congestion caused by rapid traffic changes.展开更多
Spherical mobile robot has compact structure, remarkable stability, and flexible motion,which make it have many advantages over traditional mobile robots when applied in those unmanned environments, such as outer plan...Spherical mobile robot has compact structure, remarkable stability, and flexible motion,which make it have many advantages over traditional mobile robots when applied in those unmanned environments, such as outer planets. However, spherical mobile robot is a special highly under-actuated nonholonomic system, which cannot be transformed to the classic chained form. At present, there has not been a kinematics-based trajectory tracking controller which could track both the position states and the attitude states of a spherical mobile robot. In this paper, the four-state(two position states and two attitude states) trajectory tracking control of a type of spherical mobile robot driven by a 2-DOF pendulum was studied. A controller based on the shunting model of neurodynamics and the kinematic model was deduced, and its stability was demonstrated with Lyapunov’s direct method. The control priorities of the four states were allocated according to the magnification of each state tracking error in order to firstly ensure the correct tracking of the position states. The outputs(motor speeds) of the controller were regulated according to the maximum speeds and the maximum accelerations of the actuation motors in order to solve the speed jump problem caused by initial state errors, and continuous and bounded outputs were obtained. The effectiveness including the anti-interference ability of the proposed trajectory tracking controller was verified through MATLAB simulations.展开更多
The increasing availability of data in the urban context(e.g.,mobile phone,smart card and social media data)allows us to study urban dynamics at much finer temporal resolutions(e.g.,diurnal urban dynamics).Mobile phon...The increasing availability of data in the urban context(e.g.,mobile phone,smart card and social media data)allows us to study urban dynamics at much finer temporal resolutions(e.g.,diurnal urban dynamics).Mobile phone data,for instance,are found to be a useful data source for extracting diurnal human mobility patterns and for understanding urban dynamics.While previous studies often use call detail record(CDR)data,this study deploys aggregated network-driven mobile phone data that may reveal human mobility patterns more comprehensively and can mitigate some of the privacy concerns raised by mobile phone data usage.We first propose an analytical framework for characterizing and classifying urban areas based on their temporal activity patterns extracted from mobile phone data.Specifically,urban areas’diurnal spatiotemporal signatures of human mobility patterns are obtained through longitudinal mobile phone data.Urban areas are then classified based on the obtained signatures.The classification provides insights into city planning and development.Using the proposed framework,a case study was implemented in the city of Wuhu,China to understand its urban dynamics.The empirical study suggests that human activities in the city of Wuhu are highly concentrated at the Traffic Analysis Zone(TAZ)level.This large portion of local activities suggests that development and planning strategies that are different from those used by metropolitan Chinese cities should be applied in the city of Wuhu.This article concludes with discussions on several common challenges associated with using network-driven mobile phone data,which should be addressed in future studies.展开更多
Quantification of deep drainage and the response of soil water content to rainfall patterns are critical for an effective management strategy of soil water conservation and groundwater utilization. However, there has ...Quantification of deep drainage and the response of soil water content to rainfall patterns are critical for an effective management strategy of soil water conservation and groundwater utilization. However, there has been little information on how rainfall characteristics influence soil water dynamics and deep drainage in mobile sandy lands. We used an underground chamber to examine the responses of deep drainage and soil water content in mobile sandy lands to rainfall characteristics in Inner Mongolia during the growing seasons of 2010, 2011 and 2012. Results showed that rainfall in this area was dominated by small events （〈5 mm）, which increased soil water con- tent in the surface soil layers （0-40 cm）, but did not increase soil water content in the deeper soil layers （greater than 40 cm）. Soil water content at the 0-100 cm depth increased significantly when the total amount of rain was 〉20 mm. Rainfall amount, intensity and the duration of dry intervals were significantly related to the soil water content in different soil layers. Deep drainage was significantly correlated with rainfall amount and intensity, but not with the duration of dry intervals. The coefficients of deep drainage in the mobile sandy lands ranged from 61.30% to 67.94% during the growing seasons. Our results suggested that rainfall infiltration in the mobile sandy lands had considerable potential to increase soil water storage while recharging the groundwater in this region.展开更多
This review paper focuses on cooperative robotic arms with mobile or drone bases performing cooperative tasks. This is because cooperative robots are often used as risk-reduction tools to human life. For example, they...This review paper focuses on cooperative robotic arms with mobile or drone bases performing cooperative tasks. This is because cooperative robots are often used as risk-reduction tools to human life. For example, they are used to explore dangerous places such as minefields and disarm explosives. Drones can be used to perform tasks such as aerial photography, military and defense missions,agricultural surveys, etc. The bases of the cooperative robotic arms can be stationary, mobile(ground), or drones. Cooperative manipulators allow faster performance of assigned tasks because of the available "extra hand". Furthermore, a mobile base increases the reachable ground workspace of cooperative manipulators while a drone base drastically increases this workspace to include the aerial space.The papers in this review are chosen to extensively cover a wide variety of cooperative manipulation tasks and industries that use them.In cooperative manipulation, avoiding self-collision is one of the most important tasks to be performed. In addition, path planning and formation control can be challenging because of the increased number of components to be coordinated.展开更多
Locomotion and manipulation optimization is essential for the performance of tetrahedron-based mobile mechanism. Most of current optimization methods are constrained to the continuous actuated system with limited degr...Locomotion and manipulation optimization is essential for the performance of tetrahedron-based mobile mechanism. Most of current optimization methods are constrained to the continuous actuated system with limited degree of freedom(DOF), which is infeasible to the optimization of binary control multi-DOF system. A novel optimization method using for the locomotion and manipulation of an 18 DOFs tetrahedron-based mechanism called 5-TET is proposed. The optimization objective is to realize the required locomotion by executing the least number of struts.Binary control strategy is adopted, and forward kinematic and tipping dynamic analyses are performed, respectively.Based on a developed genetic algorithm(GA), the optimal number of alternative struts between two adjacent steps is obtained as 5. Finally, a potential manipulation function is proposed, and the energy consumption comparison between optimal 5-TET and the traditional wheeled robot is carried out. The presented locomotion optimization and manipulation planning enrich the research of tetrahedron-based mechanisms and provide the instruction to the successive locomotion and operation planning of multi-DOF mechanisms.展开更多
Path planning of a mobile robot in the presence of multiple moving obstacles is found to be a complicated problem.A planning algorithm capable of negotiating both static and moving obstacles in an unpredictable(on-lin...Path planning of a mobile robot in the presence of multiple moving obstacles is found to be a complicated problem.A planning algorithm capable of negotiating both static and moving obstacles in an unpredictable(on-line)environment is proposed.The proposed incremental algorithm plans the path by considering the quadrants in which the current positions of obstacles as well as target are situated.Also,the governing equations for the shortest path are derived.The proposed mathematical model describes the motion(satisfying constraints of the mobile robot)along a collision-free path.Further,the algorithm is applicable to dynamic environments with fixed or moving targets.Simulation results show the effectiveness of the proposed algorithm.Comparison of results with the improved artificial potential field(iAPF)algorithm shows that the proposed algorithm yields shorter path length with less computation time.展开更多
Hypertext transfer protocol(HTTP) adaptive streaming(HAS) plays a key role in mobile video transmission. Considering the multi-segment and multi-rate features of HAS, this paper proposes a buffer-driven resource manag...Hypertext transfer protocol(HTTP) adaptive streaming(HAS) plays a key role in mobile video transmission. Considering the multi-segment and multi-rate features of HAS, this paper proposes a buffer-driven resource management(BDRM) method to enhance HAS quality of experience(QoE) in mobile network. Different from the traditional methods only focusing on base station side without considering the buffer, the proposed method takes both station and client sides into account and end user's buffer plays as the drive of whole schedule process. The proposed HAS QoE influencing factors are composed of initial delay, rebuffering and quality level. The BDRM method decomposes the HAS QoE maximization problem into client and base station sides separately to solve it in multicell and multi-user video playing scene in mobile network. In client side, the decision is made based on buffer probe and rate request algorithm by each user separately. It guarantees the less rebuffering events and decides which HAS segment rate to fetch. While, in the base station side, the schedule of wireless resource is made to maximize the quality level of all access clients and decides the final rate pulled from HAS server. The drive of buffer and twice rate request schemes make BDRMtake full advantage of HAS's multi-segment and multi-rate features. As to the simulation results, compared with proportional fair(PF), Max C/I and traditional HAS schedule(THS) methods, the proposed BDRM method decreases rebuffering percent to 1.96% from 11.1% with PF and from 7.01% with THS and increases the mean MOS of all users to 3.94 from 3.42 with PF method and from 2.15 with Max C/I method. It also guarantees a high fairness with 0.98 from the view of objective and subjective assessment metrics.展开更多
Marine mobile buoy（MMB） have many potential applications in the maritime industry and ocean science.Great progress has been made,however the technology in this area is far from maturity in theory and faced with many...Marine mobile buoy（MMB） have many potential applications in the maritime industry and ocean science.Great progress has been made,however the technology in this area is far from maturity in theory and faced with many difficulties in application.A dynamic model of the propulsion mechanism is very necessary for optimizing the parameters of the MMB,especially with consideration of hydrodynamic force.The principle of wave-driven propulsion mechanism is briefly introduced.To set a theory foundation for study on the MMB,a dynamic model of the propulsion mechanism of the MMB is obtained.The responses of the motion of the platform and the hydrofoil are obtained by using a numerical integration method to solve the ordinary differential equations.A simplified form of the motion equations is reached by omitting terms with high order small values.The relationship among the heave motion of the buoy,stiffness of the elastic components,and the forward speed can be obtained by using these simplified equations.The dynamic analysis show the following：The angle of displacement of foil is fairly small with the biggest value around 0.3 rad;The speed of mobile buoy and the angle of hydrofoil increased gradually with the increase of heave motion of buoy;The relationship among heaven motion,stiffness and attack angle is that heave motion leads to the angle change of foil whereas the item of speed or push function is determined by vertical velocity and angle,therefore,the heave motion and stiffness can affect the motion of buoy significantly if the size of hydrofoil is kept constant.The proposed model is provided to optimize the parameters of the MMB and a foundation is laid for improving the performance of the MMB.展开更多
A 27-year-old man with recurrent right lower quadrant pain was admitted to our hospital. Ultrasonography and computed tomography examination of the abdomen revealed a target sign in the ascending colon, which was comp...A 27-year-old man with recurrent right lower quadrant pain was admitted to our hospital. Ultrasonography and computed tomography examination of the abdomen revealed a target sign in the ascending colon, which was compatible with the diagnosis of cecal intussusception. The intussusception was spontaneously resolved at that time, but it relapsed 6 mo later. The patient underwent a successful colonoscopic disinvagination; there was no evidence of neoplastic or inflammatory lesions in the colon and terminal ileum. The patient underwent laparoscopic surgery for recurring cecal intussusception. During laparoscopy, we observed an unfixed cecum on the posterior peritoneum(i.e. a mobile cecum). Thus, we performed laparoscopic appendectomy and cecopexy with a lateral peritoneal flap using a barbed wound suture device. The patient's post-operative course was uneventful, and he continued to do well without recurrence at 10 mo after surgery. Laparoscopic cecopexy using a barbed wound suture device is a simple and reliable procedure that can be the treatment of choice for recurrent cecal intussusception associated with a mobile cecum.展开更多
The electrically driven large-load-ratio six-legged robot with engineering capability can be widely used in outdoor and planetary exploration.However,due to the particularity of its parallel structure,the effective ut...The electrically driven large-load-ratio six-legged robot with engineering capability can be widely used in outdoor and planetary exploration.However,due to the particularity of its parallel structure,the effective utilization rate of energy is not high,which has become an important obstacle to its practical application.To research the power consumption characteristics of robot mobile system is beneficial to speed up it toward practicability.Based on the configuration and walking modes of robot,the mathematical model of the power consumption of mobile system is set up.In view of the tripod gait is often selected for the six-legged robots,the simplified power consumption model of mobile system under the tripod gait is established by means of reducing the dimension of the robot’s statically indeterminate problem and constructing the equal force distribution.Then,the power consumption of robot mobile system is solved under different working conditions.The variable tendencies of the power consumption of robot mobile system are respectively obtained with changes in the rotational angles of hip joint and knee joint,body height,and span.The articulated rotational zones and the ranges of body height and span are determined under the lowest power consumption.According to the walking experiments of prototype,the variable tendencies of the average power consumption of robot mobile system are respectively acquired with changes in duty ratio,body height,and span.Then,the feasibility and correctness of theory analysis are verified in the power consumption of robot mobile system.The proposed analysis method in this paper can provide a reference on the lower power research of the large-load-ratio multi-legged robots.展开更多
Monocyclic aromatic hydrocarbons(MAHs)and polycyclic aromatic hydrocarbons(PAHs)are both well known as hazardous air pollutants and also important anthropogenic precursors of tropospheric ozone(O3)and secondary organi...Monocyclic aromatic hydrocarbons(MAHs)and polycyclic aromatic hydrocarbons(PAHs)are both well known as hazardous air pollutants and also important anthropogenic precursors of tropospheric ozone(O3)and secondary organic aerosols(SOA).In recent years,there have been intensive studies covering MAHs emission from various sources and their behavior under stimulated photochemical conditions.Yet in-situ measurements of PAHs presence and variations in ambient air are sparse.Herein we conducted large geometrical scale mobile measurements for 16 aromatic hydrocarbons(AHs,including 7 MAHs and 9 PAHs)in eastern China between October 27 and November 8,2019.This unique dataset has allowed for some insights in terms of AHs concentration variations,accompanying chemical composition,source contributions and spatial distributions in eastern China.In general,AHs showed a clear concentration variability between the south and the north of the Yangtze River Delta(YRD).The concentrations of PAHs were approximately 9%of AHs,but contributed 23%of SOA formation potential.Source apportionment via positive matrix factorization(PMF)model revealed that industrial processes as the largest source(44%)of observed AHs,followed by solvent usage(21%),vehicle exhaust(19%),coal combustion(11%)and coking processes(6%).In the perspective of PAHs sources,coal combustion emissions were identified as the dominating factor of a share of 41%–52%in eastern China.Our findings complemented the simultaneously monitoring information of PAHs and MAHs in eastern China,revealed the importance of PAHs to SOA formation and highlighted the necessity of formulating strategies to reduce emissions from anthropogenic sources and reduce risks to human health.展开更多
This paper analyzes the key technology of mobile GIS development, discusses the design method of mobile GIS spatial data management, visualization of spatial data And Spatial data query, tinder Object oriented mode. A...This paper analyzes the key technology of mobile GIS development, discusses the design method of mobile GIS spatial data management, visualization of spatial data And Spatial data query, tinder Object oriented mode. And we develop a set of mobile GIS basic software platform in the Android platform, and tested in the mainstream smart mobile phone with Android operating system, test results show that the software platform can run smoothly. Other users can development a variety of mobile GIS to call the platform through an application service interface.展开更多
基金This work is supported by the National Key R&D Program of China under grant 2018YFB1003205by the National Natural Science Foundation of China under grant U1836208,U1536206,U1836110,61602253,61672294+2 种基金by the Jiangsu Basic Research Programs-Natural Science Foundation under grant numbers BK20181407by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)fundby the Collaborative Innovation Center of Atmospheric Environment and Equipment Technology(CICAEET)fund,China。
文摘Drone also known as unmanned aerial vehicle(UAV)has drawn lots of attention in recent years.Quadcopter as one of the most popular drones has great potential in both industrial and academic fields.Quadcopter drones are capable of taking off vertically and flying towards any direction.Traditional researches of drones mainly focus on their mechanical structures and movement control.The aircraft movement is usually controlled by a remote controller manually or the trajectory is pre-programmed with specific algorithms.Consumer drones typically use mobile device together with remote controllers to realize flight control and video transmission.Implementing different functions on mobile devices can result in different behaviors of drones indirectly.With the development of deep learning in computer vision field,commercial drones equipped with camera can be much more intelligent and even realize autonomous flight.In the past,running deep learning based algorithms on mobile devices is highly computational intensive and time consuming.This paper utilizes a novel real-time object detection method and deploys the deep learning model on the modern mobile device to realize autonomous object detection and object tracking of drones.
文摘Achieving mobile liquid droplets on solid surfaces is crucial for various practical applications,such as self-cleaning and anti-fouling coatings.The last two decades have witnessed remarkable progress in designing functional surfaces,including superrepellent surfaces and lubricant-infused surfaces,which allow droplets to roll/slide on the surfaces.However,it remains a challenge to enable droplet motion on hydrophilic solid surfaces.In this work,we demonstrate mobile droplets containing ionic surfactants on smooth hydrophilic surfaces that are charged similarly to surfactant molecules.The ionic surfactant-laden droplets display ultra-low contact angle and ultra-low sliding angle simultaneously on the hydrophilic surfaces.The sliding of the droplet is enabled by the adsorbed surfactant ahead of three-phase contact line,which is regulated by the electrostatic interaction between ionic surfactant and charged solid surface.The droplet can maintain its motion even when the hydrophilic surface has defects.Furthermore,we demonstrate controlled manipulation of ionic surfactantladen droplets on hydrophilic surfaces with different patterns.We envision that our simple technique for achieving mobile droplets on hydrophilic surfaces can pave the way to novel slippery surfaces for different applications.
基金Supported by Project of the Health Bureau of the Logistics and Security Department of the Central Military Commission,No.145BHQ090003076XMilitary Family Planning Special Fund,No.21JSZ18.
文摘BACKGROUND Children with critical acute abdominal conditions often undergo intestinal stoma surgery.AIM To explore the impact of a visual mobile terminal-based extended care model on caregiver competence for children with enterostomies.METHODS One hundred twenty children with enterostomies and their caregivers in a children's hospital in Beijing were divided into a control group and a study group.The control group(60 cases)received traditional telephone follow-up for continuity of care,while the study group(60 cases)used a visualization mobile terminal-based care model.The incidence of stoma-related complications,caregiver burden scale,and competence scores of children with stoma were compared between the two groups.RESULTS The primary caregiver burden score in the study group(37.22±3.17)was significantly lower than that in the control group(80.00±4.47),and the difference was statistically significant(P<0.05).Additionally,the caregiving ability score of the study group(172.08±3.49)was significantly higher than that of the control group(117.55±4.28;P<0.05).The total incidence of complications in the study group(11.7%,7/60)was significantly lower compared to the control group(33.3%,20/60;χ2=8.086,P=0.004).CONCLUSION The visual mobile terminal-based care model reduces caregiver burden,improves home care ability,lowers the incidence of complications and readmission rates,and supports successful second-stage reduction surgery for children with enterostomies.
文摘During the process of urbanization,community environments encounter challenges such as data disconnection and the underutilization of small and micro spaces.The establishment of“complete communities”necessitates the implementation of refined governance strategies.This research develops a path for the precise establishment of community micro-gardens driven by mobile measurement.It involves the collection of environmental data via mobile devices equipped with various types of sensors,the generation of visualization maps that are adjusted for spatio-temporal synchronization,and the identification of environmental paint points,including areas of excessive temperature exposure and zones with elevated noise levels.Based on the aforementioned considerations,various plant allocation strategies have been proposed for distinct areas.For instance,the implementation of a composite shade and cooling vegetation system is recommended for regions experiencing high temperatures,while a triple protection structure is suggested for areas affected by odor contamination.The efficacy of these strategies is demonstrated through a case study of the micro-garden transformation in the Dongjie Community of Wulituo Street,Shijingshan,Beijing.The study presents operational technical pathways and plant response solutions aimed at facilitating data-driven governance of community micro-environments.
文摘At present,energy consumption is one of the main bottlenecks in autonomous mobile robot development.To address the challenge of high energy consumption in path planning for autonomous mobile robots navigating unknown and complex environments,this paper proposes an Attention-Enhanced Dueling Deep Q-Network(ADDueling DQN),which integrates a multi-head attention mechanism and a prioritized experience replay strategy into a Dueling-DQN reinforcement learning framework.A multi-objective reward function,centered on energy efficiency,is designed to comprehensively consider path length,terrain slope,motion smoothness,and obstacle avoidance,enabling optimal low-energy trajectory generation in 3D space from the source.The incorporation of a multihead attention mechanism allows the model to dynamically focus on energy-critical state features—such as slope gradients and obstacle density—thereby significantly improving its ability to recognize and avoid energy-intensive paths.Additionally,the prioritized experience replay mechanism accelerates learning from key decision-making experiences,suppressing inefficient exploration and guiding the policy toward low-energy solutions more rapidly.The effectiveness of the proposed path planning algorithm is validated through simulation experiments conducted in multiple off-road scenarios.Results demonstrate that AD-Dueling DQN consistently achieves the lowest average energy consumption across all tested environments.Moreover,the proposed method exhibits faster convergence and greater training stability compared to baseline algorithms,highlighting its global optimization capability under energy-aware objectives in complex terrains.This study offers an efficient and scalable intelligent control strategy for the development of energy-conscious autonomous navigation systems.
基金The National Basic Research Program of China(973 Program)(No.2009CB320501)the National Natural Science Foundation of China(No.61370209,61272532)the Natural Science Foundation of Jiangsu Province(No.BK2010414,BK2011335)
文摘In order to save the energy and reduce the latency of the end-to-end transmission in mobile ad hoc networks an adaptive and distance-driven power control ADPC scheme is proposed by means of distance research in random geometrics. Through mathematical proof the optimal number of relay nodes and the optimal location of each node for data transmission can be obtained when a distance is given.In the ADPC first the source node computes the optimal number and the sites of the relay nodes between the source and the destination nodes.Then it searches feasible relay nodes around the optimal virtual relay-sites and selects one link with the minimal total transmission energy consumption for data transmission.Simulation results show that the ADPC can reduce both the energy dissipation and the end-to-end latency of the transmission.
基金partially supported by the National Natural Science Foundation of China(61751306,61801208,61671233)the Jiangsu Science Foundation(BK20170650)+2 种基金the Postdoctoral Science Foundation of China(BX201700118,2017M621712)the Jiangsu Postdoctoral Science Foundation(1701118B)the Fundamental Research Funds for the Central Universities(021014380094)
文摘During the past few decades,mobile wireless communications have experienced four generations of technological revolution,namely from 1 G to 4 G,and the deployment of the latest 5 G networks is expected to take place in 2019.One fundamental question is how we can push forward the development of mobile wireless communications while it has become an extremely complex and sophisticated system.We believe that the answer lies in the huge volumes of data produced by the network itself,and machine learning may become a key to exploit such information.In this paper,we elaborate why the conventional model-based paradigm,which has been widely proved useful in pre-5 G networks,can be less efficient or even less practical in the future 5 G and beyond mobile networks.Then,we explain how the data-driven paradigm,using state-of-the-art machine learning techniques,can become a promising solution.At last,we provide a typical use case of the data-driven paradigm,i.e.,proactive load balancing,in which online learning is utilized to adjust cell configurations in advance to avoid burst congestion caused by rapid traffic changes.
文摘Spherical mobile robot has compact structure, remarkable stability, and flexible motion,which make it have many advantages over traditional mobile robots when applied in those unmanned environments, such as outer planets. However, spherical mobile robot is a special highly under-actuated nonholonomic system, which cannot be transformed to the classic chained form. At present, there has not been a kinematics-based trajectory tracking controller which could track both the position states and the attitude states of a spherical mobile robot. In this paper, the four-state(two position states and two attitude states) trajectory tracking control of a type of spherical mobile robot driven by a 2-DOF pendulum was studied. A controller based on the shunting model of neurodynamics and the kinematic model was deduced, and its stability was demonstrated with Lyapunov’s direct method. The control priorities of the four states were allocated according to the magnification of each state tracking error in order to firstly ensure the correct tracking of the position states. The outputs(motor speeds) of the controller were regulated according to the maximum speeds and the maximum accelerations of the actuation motors in order to solve the speed jump problem caused by initial state errors, and continuous and bounded outputs were obtained. The effectiveness including the anti-interference ability of the proposed trajectory tracking controller was verified through MATLAB simulations.
基金Under the auspices of the National Natural Science Foundation of China(No.41571146)China Postdoctoral Science Foundation(No.2019M651784)。
文摘The increasing availability of data in the urban context(e.g.,mobile phone,smart card and social media data)allows us to study urban dynamics at much finer temporal resolutions(e.g.,diurnal urban dynamics).Mobile phone data,for instance,are found to be a useful data source for extracting diurnal human mobility patterns and for understanding urban dynamics.While previous studies often use call detail record(CDR)data,this study deploys aggregated network-driven mobile phone data that may reveal human mobility patterns more comprehensively and can mitigate some of the privacy concerns raised by mobile phone data usage.We first propose an analytical framework for characterizing and classifying urban areas based on their temporal activity patterns extracted from mobile phone data.Specifically,urban areas’diurnal spatiotemporal signatures of human mobility patterns are obtained through longitudinal mobile phone data.Urban areas are then classified based on the obtained signatures.The classification provides insights into city planning and development.Using the proposed framework,a case study was implemented in the city of Wuhu,China to understand its urban dynamics.The empirical study suggests that human activities in the city of Wuhu are highly concentrated at the Traffic Analysis Zone(TAZ)level.This large portion of local activities suggests that development and planning strategies that are different from those used by metropolitan Chinese cities should be applied in the city of Wuhu.This article concludes with discussions on several common challenges associated with using network-driven mobile phone data,which should be addressed in future studies.
基金financially supported by the National Natural Science Foundation of China (41371053, 31270501)the National Science and Technology Planning Project (2011BAC07B02)+1 种基金the Strategic Forerunner Project of Science and Technology, Chineses Academy of Sciences (XDA05050201-04-01)the Special Scientific Research Fund (201109025-2)
文摘Quantification of deep drainage and the response of soil water content to rainfall patterns are critical for an effective management strategy of soil water conservation and groundwater utilization. However, there has been little information on how rainfall characteristics influence soil water dynamics and deep drainage in mobile sandy lands. We used an underground chamber to examine the responses of deep drainage and soil water content in mobile sandy lands to rainfall characteristics in Inner Mongolia during the growing seasons of 2010, 2011 and 2012. Results showed that rainfall in this area was dominated by small events （〈5 mm）, which increased soil water con- tent in the surface soil layers （0-40 cm）, but did not increase soil water content in the deeper soil layers （greater than 40 cm）. Soil water content at the 0-100 cm depth increased significantly when the total amount of rain was 〉20 mm. Rainfall amount, intensity and the duration of dry intervals were significantly related to the soil water content in different soil layers. Deep drainage was significantly correlated with rainfall amount and intensity, but not with the duration of dry intervals. The coefficients of deep drainage in the mobile sandy lands ranged from 61.30% to 67.94% during the growing seasons. Our results suggested that rainfall infiltration in the mobile sandy lands had considerable potential to increase soil water storage while recharging the groundwater in this region.
基金by Botswana International University of Science and Technology(BIUST)Drones Project(No.P00015).
文摘This review paper focuses on cooperative robotic arms with mobile or drone bases performing cooperative tasks. This is because cooperative robots are often used as risk-reduction tools to human life. For example, they are used to explore dangerous places such as minefields and disarm explosives. Drones can be used to perform tasks such as aerial photography, military and defense missions,agricultural surveys, etc. The bases of the cooperative robotic arms can be stationary, mobile(ground), or drones. Cooperative manipulators allow faster performance of assigned tasks because of the available "extra hand". Furthermore, a mobile base increases the reachable ground workspace of cooperative manipulators while a drone base drastically increases this workspace to include the aerial space.The papers in this review are chosen to extensively cover a wide variety of cooperative manipulation tasks and industries that use them.In cooperative manipulation, avoiding self-collision is one of the most important tasks to be performed. In addition, path planning and formation control can be challenging because of the increased number of components to be coordinated.
基金Supported by National Science-Technology Support Plan Projects of China (Grant No.2015BAK04B00)2015 Sino-German Postdoc Scholarship Program (Grant No.57165010)
文摘Locomotion and manipulation optimization is essential for the performance of tetrahedron-based mobile mechanism. Most of current optimization methods are constrained to the continuous actuated system with limited degree of freedom(DOF), which is infeasible to the optimization of binary control multi-DOF system. A novel optimization method using for the locomotion and manipulation of an 18 DOFs tetrahedron-based mechanism called 5-TET is proposed. The optimization objective is to realize the required locomotion by executing the least number of struts.Binary control strategy is adopted, and forward kinematic and tipping dynamic analyses are performed, respectively.Based on a developed genetic algorithm(GA), the optimal number of alternative struts between two adjacent steps is obtained as 5. Finally, a potential manipulation function is proposed, and the energy consumption comparison between optimal 5-TET and the traditional wheeled robot is carried out. The presented locomotion optimization and manipulation planning enrich the research of tetrahedron-based mechanisms and provide the instruction to the successive locomotion and operation planning of multi-DOF mechanisms.
文摘Path planning of a mobile robot in the presence of multiple moving obstacles is found to be a complicated problem.A planning algorithm capable of negotiating both static and moving obstacles in an unpredictable(on-line)environment is proposed.The proposed incremental algorithm plans the path by considering the quadrants in which the current positions of obstacles as well as target are situated.Also,the governing equations for the shortest path are derived.The proposed mathematical model describes the motion(satisfying constraints of the mobile robot)along a collision-free path.Further,the algorithm is applicable to dynamic environments with fixed or moving targets.Simulation results show the effectiveness of the proposed algorithm.Comparison of results with the improved artificial potential field(iAPF)algorithm shows that the proposed algorithm yields shorter path length with less computation time.
基金supported by the 863 project (Grant No. 2014AA01A701) Beijing Natural Science Foundation (Grant No. 4152047)
文摘Hypertext transfer protocol(HTTP) adaptive streaming(HAS) plays a key role in mobile video transmission. Considering the multi-segment and multi-rate features of HAS, this paper proposes a buffer-driven resource management(BDRM) method to enhance HAS quality of experience(QoE) in mobile network. Different from the traditional methods only focusing on base station side without considering the buffer, the proposed method takes both station and client sides into account and end user's buffer plays as the drive of whole schedule process. The proposed HAS QoE influencing factors are composed of initial delay, rebuffering and quality level. The BDRM method decomposes the HAS QoE maximization problem into client and base station sides separately to solve it in multicell and multi-user video playing scene in mobile network. In client side, the decision is made based on buffer probe and rate request algorithm by each user separately. It guarantees the less rebuffering events and decides which HAS segment rate to fetch. While, in the base station side, the schedule of wireless resource is made to maximize the quality level of all access clients and decides the final rate pulled from HAS server. The drive of buffer and twice rate request schemes make BDRMtake full advantage of HAS's multi-segment and multi-rate features. As to the simulation results, compared with proportional fair(PF), Max C/I and traditional HAS schedule(THS) methods, the proposed BDRM method decreases rebuffering percent to 1.96% from 11.1% with PF and from 7.01% with THS and increases the mean MOS of all users to 3.94 from 3.42 with PF method and from 2.15 with Max C/I method. It also guarantees a high fairness with 0.98 from the view of objective and subjective assessment metrics.
基金Supported by National Natural Science Foundation of China(Grant No.51175484)Program for New Century Excellent Talents in University,China(Grant No.NCET-12-0500)+1 种基金Program of Introducing Talents of Discipline to Universities,China(Grant No.B14028)Fundamental Research Funds for the Central Universities,China(Grant No.841513053)
文摘Marine mobile buoy（MMB） have many potential applications in the maritime industry and ocean science.Great progress has been made,however the technology in this area is far from maturity in theory and faced with many difficulties in application.A dynamic model of the propulsion mechanism is very necessary for optimizing the parameters of the MMB,especially with consideration of hydrodynamic force.The principle of wave-driven propulsion mechanism is briefly introduced.To set a theory foundation for study on the MMB,a dynamic model of the propulsion mechanism of the MMB is obtained.The responses of the motion of the platform and the hydrofoil are obtained by using a numerical integration method to solve the ordinary differential equations.A simplified form of the motion equations is reached by omitting terms with high order small values.The relationship among the heave motion of the buoy,stiffness of the elastic components,and the forward speed can be obtained by using these simplified equations.The dynamic analysis show the following：The angle of displacement of foil is fairly small with the biggest value around 0.3 rad;The speed of mobile buoy and the angle of hydrofoil increased gradually with the increase of heave motion of buoy;The relationship among heaven motion,stiffness and attack angle is that heave motion leads to the angle change of foil whereas the item of speed or push function is determined by vertical velocity and angle,therefore,the heave motion and stiffness can affect the motion of buoy significantly if the size of hydrofoil is kept constant.The proposed model is provided to optimize the parameters of the MMB and a foundation is laid for improving the performance of the MMB.
文摘A 27-year-old man with recurrent right lower quadrant pain was admitted to our hospital. Ultrasonography and computed tomography examination of the abdomen revealed a target sign in the ascending colon, which was compatible with the diagnosis of cecal intussusception. The intussusception was spontaneously resolved at that time, but it relapsed 6 mo later. The patient underwent a successful colonoscopic disinvagination; there was no evidence of neoplastic or inflammatory lesions in the colon and terminal ileum. The patient underwent laparoscopic surgery for recurring cecal intussusception. During laparoscopy, we observed an unfixed cecum on the posterior peritoneum(i.e. a mobile cecum). Thus, we performed laparoscopic appendectomy and cecopexy with a lateral peritoneal flap using a barbed wound suture device. The patient's post-operative course was uneventful, and he continued to do well without recurrence at 10 mo after surgery. Laparoscopic cecopexy using a barbed wound suture device is a simple and reliable procedure that can be the treatment of choice for recurrent cecal intussusception associated with a mobile cecum.
基金National Natural Science Foundation of China(Grant No.51505335)Industry University Cooperation Collaborative Education Project of the Department of Higher Education of the Ministry of Education of China(Grant No.202102517001)Doctor Startup Projects of TUTE of China(Grant No.KYQD1806)。
文摘The electrically driven large-load-ratio six-legged robot with engineering capability can be widely used in outdoor and planetary exploration.However,due to the particularity of its parallel structure,the effective utilization rate of energy is not high,which has become an important obstacle to its practical application.To research the power consumption characteristics of robot mobile system is beneficial to speed up it toward practicability.Based on the configuration and walking modes of robot,the mathematical model of the power consumption of mobile system is set up.In view of the tripod gait is often selected for the six-legged robots,the simplified power consumption model of mobile system under the tripod gait is established by means of reducing the dimension of the robot’s statically indeterminate problem and constructing the equal force distribution.Then,the power consumption of robot mobile system is solved under different working conditions.The variable tendencies of the power consumption of robot mobile system are respectively obtained with changes in the rotational angles of hip joint and knee joint,body height,and span.The articulated rotational zones and the ranges of body height and span are determined under the lowest power consumption.According to the walking experiments of prototype,the variable tendencies of the average power consumption of robot mobile system are respectively acquired with changes in duty ratio,body height,and span.Then,the feasibility and correctness of theory analysis are verified in the power consumption of robot mobile system.The proposed analysis method in this paper can provide a reference on the lower power research of the large-load-ratio multi-legged robots.
基金supported by the National Natural Science Foundation of China(No.42175135)the Science and Technology Commission of the Shanghai Municipality(No.20ZR1447800).
文摘Monocyclic aromatic hydrocarbons(MAHs)and polycyclic aromatic hydrocarbons(PAHs)are both well known as hazardous air pollutants and also important anthropogenic precursors of tropospheric ozone(O3)and secondary organic aerosols(SOA).In recent years,there have been intensive studies covering MAHs emission from various sources and their behavior under stimulated photochemical conditions.Yet in-situ measurements of PAHs presence and variations in ambient air are sparse.Herein we conducted large geometrical scale mobile measurements for 16 aromatic hydrocarbons(AHs,including 7 MAHs and 9 PAHs)in eastern China between October 27 and November 8,2019.This unique dataset has allowed for some insights in terms of AHs concentration variations,accompanying chemical composition,source contributions and spatial distributions in eastern China.In general,AHs showed a clear concentration variability between the south and the north of the Yangtze River Delta(YRD).The concentrations of PAHs were approximately 9%of AHs,but contributed 23%of SOA formation potential.Source apportionment via positive matrix factorization(PMF)model revealed that industrial processes as the largest source(44%)of observed AHs,followed by solvent usage(21%),vehicle exhaust(19%),coal combustion(11%)and coking processes(6%).In the perspective of PAHs sources,coal combustion emissions were identified as the dominating factor of a share of 41%–52%in eastern China.Our findings complemented the simultaneously monitoring information of PAHs and MAHs in eastern China,revealed the importance of PAHs to SOA formation and highlighted the necessity of formulating strategies to reduce emissions from anthropogenic sources and reduce risks to human health.
文摘This paper analyzes the key technology of mobile GIS development, discusses the design method of mobile GIS spatial data management, visualization of spatial data And Spatial data query, tinder Object oriented mode. And we develop a set of mobile GIS basic software platform in the Android platform, and tested in the mainstream smart mobile phone with Android operating system, test results show that the software platform can run smoothly. Other users can development a variety of mobile GIS to call the platform through an application service interface.
