Background: Prematurely-born individuals tend to exhibit higher resting oxidative stress, although evidence suggests they may be more resistant to acute hypoxia-induced redox balance alterations. We aimed to investiga...Background: Prematurely-born individuals tend to exhibit higher resting oxidative stress, although evidence suggests they may be more resistant to acute hypoxia-induced redox balance alterations. We aimed to investigate the redox balance changes across a 3-day hypobaric hypoxic exposure at 3375 m in healthy adults born preterm(gestational age ≤ 32 weeks) and their term-born(gestational age ≥ 38 weeks)counterparts.Methods: Resting venous blood was obtained in normoxia(prior to altitude exposure), immediately upon arrival to altitude, and the following 3mornings. Antioxidant(superoxide dismutase(SOD), catalase, glutathione peroxidase(GPx), and ferric reducing antioxidant power(FRAP)),pro-oxidant(xanthine oxidase(XO) and myeloperoxidase(MPO)) enzyme activity, oxidative stress markers(advanced oxidation protein product(AOPP) and malondialdehyde(MDA)), nitric oxide(NO) metabolites(nitrites, nitrates, and total nitrite and nitrate(NOx)), and nitrotyrosine were measured in plasma.Results: SOD increased only in the preterm group(p < 0.05). Catalase increased at arrival in preterm group(p < 0.05). XO activity increased at Day 3 for the preterm group, while it increased acutely(arrival and Day 1) in control group. MPO increased in both groups throughout the3 days(p < 0.05). AOPP only increased at arrival in the preterm(p < 0.05) whereas it decreased at arrival up to Day 3(p < 0.05) for control.MDA decreased in control group from arrival onward. Nitrotyrosine decreased in both groups(p < 0.05). Nitrites increased on Day 3(p < 0.05)in control group and decreased on Day 1(p < 0.05) in preterm group.Conclusion: These data indicate that antioxidant enzymes seem to increase immediately upon hypoxic exposure in preterm adults. Conversely, the blunted pro-oxidant enzyme response to prolonged hypoxia exposure suggests that these enzymes may be less sensitive in preterm individuals.These findings lend further support to the potential hypoxic preconditioning effect of preterm birth.展开更多
While different species in nature have safely solved the problem of navigation in a dynamic environment, this remains a challenging task for researchers around the world. The paper addresses the problem of autonomous ...While different species in nature have safely solved the problem of navigation in a dynamic environment, this remains a challenging task for researchers around the world. The paper addresses the problem of autonomous navigation in an unknown dynamic environment for a single and a group of three wheeled omnidirectional mobile robots(TWOMRs). The robot has to track a dynamic target while avoiding dynamic obstacles and dynamic walls in an unknown and very dense environment. It adopts a behavior-based controller that consists of four behaviors: "target tracking", "obstacle avoidance", "dynamic wall following" and "avoid robots". The paper considers the problem of kinematic saturation. In addition, it introduces a strategy for predicting the velocity of dynamic obstacles based on two successive measurements of the ultrasonic sensors to calculate the velocity of the obstacle expressed in the sensor frame. Furthermore, the paper proposes a strategy to deal with dynamic walls even when they have U-like or V-like shapes. The approach can also deal with the formation control of a group of robots based on the leader-follower structure and the behavior-based control, where the robots have to get together and maintain a given formation while navigating toward the target, avoiding obstacles and walls in a dynamic environment. The effectiveness of the proposed approaches is demonstrated via simulation.展开更多
Based on domain specified language mechanism(DSLM),the architecture of the robotic training system for the rehabilitation of children with cerebral palsy(CP)is designed.Application of human-computer interaction(HCI)mo...Based on domain specified language mechanism(DSLM),the architecture of the robotic training system for the rehabilitation of children with cerebral palsy(CP)is designed.Application of human-computer interaction(HCI)motion recognition technology is combined with Kinect to improve the effect of cerebral palsy rehabilitation training.In this system,Kinect's bone recognition method is used to judge the patient's training movements,and the collected bone movement information is judged.The human-computer interaction function is based on the Microsoft foundation classes function of Visual Studio based on DSLM development,which can realize real-time interactive training and evaluation of people and actions,and record the training information of patients.The system combines the designed small game to train the upper limb movement ability and reaction ability of the cerebral palsy patient,and provides key technology for improving the cerebral palsy rehabilitation training system.展开更多
In this paper, we describe an algorithm that performs automatic detection and tracking of astral microtubules in fluorescence confocal images. This sub-population of microtubules only exists during and immediately bef...In this paper, we describe an algorithm that performs automatic detection and tracking of astral microtubules in fluorescence confocal images. This sub-population of microtubules only exists during and immediately before mitosis and aids in the spindle orientation by connecting it to the cell cortex. Anomalies in their dynamic behaviour play a causal role in many diseases, such as development disorders and cancer. The main novelty of the proposed algorithm lies in the fact it provides a fully automated estimation of parameters related to microtubule dynamic instability (growth velocity, track length and track lifetime), and helps in understanding the effects of intermediate drug concentrations. Its performance has been objectively assessed using publicly available synthetic data and largely employed metrics. Moreover, we present experiments addressing cell cultures doped with different concentrations of taxol and nocodazole. Such drugs are known to suppress the microtubule dynamic instability, but their effects at intermediate concentrations are not completely assessed. The algorithm has been compared with other state-of-the-art approaches, tested on consistent real datasets. The results are encouraging in terms of performance, robustness and simplicity of use, and the algorithm is now routinely employed in our Department of Molecular Biotechnology.展开更多
Through the observation and analysis of the motion trajectory of spiral winding motion for slender legless biological creatures in water,V-REP software is adopted to build a dynamic simulator to study on the mechanism...Through the observation and analysis of the motion trajectory of spiral winding motion for slender legless biological creatures in water,V-REP software is adopted to build a dynamic simulator to study on the mechanism of spiral winding swimming(SWS)motion.By using the output of spiral function(SF),the dynamic simulation model of slender legless creature(SLC)realizes the SWS motion in water.The corresponding experiments under the control of different bending angle of SF to control the dynamic model are also carried out to analyze the water performance of SWS in still water.Combined with the output of two different bending angles of the spiral function,the dynamic model can be used to realize SWS and up/down motion.This work provides technical reserve and experimental platform for the corresponding study in related fields.展开更多
In the paper the proposition of a discrete, robust, minimal energetic P servo controller for second order plant is presented. The plant under consideration is described with the use of a state space equation and a tra...In the paper the proposition of a discrete, robust, minimal energetic P servo controller for second order plant is presented. The plant under consideration is described with the use of a state space equation and a transfer function with interval parameters. The considered model describes for example an oriented PV （photovoltaic） system. As a controller a P （proportional） controller was applied. It is very simple and their application in the situation we deal with assures the suitable control performance. The controller is going to be implemented at digital platform. To construct the control system a cost function proposed by the authors was applied. It describes both the energy consumption and the sample time of controller. The proposed cost function is a function of plant parameters, describing the dynamics of the plant and controller parameters： proportional gain and sample time. For the cost function a simple geometric interpretation can be given： for fixed plant parameters and varying controller parameters it is a surface in the Ra plane. This fact can be applied to assign of optimal controller. Theoretical results were depicted by a numerical example.展开更多
State convergence is a novel control algorithm for bilateral teleoperation of robotic systems. First, it models the teleoperation system on state space and considers all the possible interactions between the master an...State convergence is a novel control algorithm for bilateral teleoperation of robotic systems. First, it models the teleoperation system on state space and considers all the possible interactions between the master and slave systems. Second, it presents an elegant design procedure which requires a set of equations to be solved in order to compute the control gains of the bilateral loop. These design conditions are obtained by turning the master-slave error into an autonomous system and imposing the desired dynamic behavior of the teleoperation system. Resultantly, the convergence of master and slave states is achieved in a well-defined manner. The present study aims at achieving a similar convergence behavior offered by state convergence controller while reducing the number of variables sent across the communication channel. The proposal suggests transmitting composite master and slave variables instead of full master and slave states while keeping the operator's force channel intact. We show that,with these composite and force variables;it is indeed possible to achieve the convergence of states in a desired way by strictly following the method of state convergence. The proposal leads to a reduced complexity state convergence algorithm which is termed as composite state convergence controller. In order to validate the proposed scheme in the absence and presence of communication time delays, MATLAB simulations and semi-real time experiments are performed on a single degree-of-freedom teleoperation system.展开更多
A method allowing a desirable matrix spectrum to be constructed as an alternative to the method using matrix transformation to the Frobenius form is stated. It can be applied to implement control algorithms for techni...A method allowing a desirable matrix spectrum to be constructed as an alternative to the method using matrix transformation to the Frobenius form is stated. It can be applied to implement control algorithms for technical systems without executing the variables transformation procedures that are needed for deriving a Frobenius matrix. The method can be used for simulation of systems with different spectrums for choosing an alternative that satisfies to the distinct demands.展开更多
Wind turbine blades have been constantly increasing since wind energy becomes a popular renewable energy source to generate electricity. Therefore, the wind sector requires a more efficient and representative characte...Wind turbine blades have been constantly increasing since wind energy becomes a popular renewable energy source to generate electricity. Therefore, the wind sector requires a more efficient and representative characterization of vertical wind speed profiles to assess the potential for a wind power plant site. This paper proposes an alternative characterization of vertical wind speed profiles based on Ward's agglomerative clustering algorithm, including both wind speed module and direction data. This approach gives a more accurate incoming wind speed variation around the rotor swept area, and subsequently, provides a more realistic and complete wind speed vector characterization for vertical profiles. Real wind database collected for 2018 in the Forschungsplattformen in Nordund Ostsee(FINO) research platform is used to assess the methodology. A preliminary pre-processing stage is proposed to select the appropriated number of heights and remove missing or incomplete data. Finally, two locations and four heights are selected, and 561588 wind data are characterized. Results and discussion are also included in this paper. The methodology can be applied to other wind database and locations to characterize vertical wind speed profiles and identify the most likely wind data vector patterns.展开更多
Precision energy management is very important for sustainability development of solar greenhouses,since huge energy demand for agricultural production both in quantity and quality.A proactive energy management,accordi...Precision energy management is very important for sustainability development of solar greenhouses,since huge energy demand for agricultural production both in quantity and quality.A proactive energy management,according to the optimal energy utilization in a look-ahead period with weather prediction,is presented and tested in this research.A multi-input-multi-output linear model of the energy balance of solar greenhouses based on on-line identification system can simulate greenhouse behavior and allow for predictive control.The good time allocation of available solar energy can be achieved by intelligent use of controls,such as store/retrieve fans and ventilation windows,i.e.solar energy to warm up the air or to be stored in the storage elements(wall,soil,etc.)or to be exhausted to outside.The proactive energy management can select an optimal trajectory of air temperature for the forecasted weather period to minimize plants’thermal‘cost’defined by an‘expert’in terms of set-points for the specific crop.The selection of temperature trajectory is formulated as a generalized traveling salesman problem(GTSP)with precedence constraints and is solved by a genetic algorithm(GA)in this research.The simulation study showed good potential for energy saving and timely allocation to prevent excessive crop stress.The active control elements in addition to predefining and applying,within energy constraints,optimal climate in the greenhouse,it also reduces the energy deficit,i.e.the working hours of the‘heater’in the sustained freezing weather,as well as the ventilation hours,that is,more energy harvest in the warm days.This intelligent solar greenhouse management system is being migrated to the web for serving a‘customer base’in the Internet Plus era.The capacity,of the concrete ground CAUA system(CAUA is an abbreviations from both China Agricultural University and Agricultural University of Athens),to implement web‘updates’of criteria,open weather data and models,on which control actions are based,is what makes use of Cloud Data for closing the loop of an effective Internet of Things(IoT)system,based on MACQU(MAnagement and Control for QUality)technological platform.展开更多
基金funded by the Swiss National Science Foundation(SNSF Grant No.320030L_192073 to GM)the Slovenian Research Agency(ARRS Grant No.N5-0152 to TD).
文摘Background: Prematurely-born individuals tend to exhibit higher resting oxidative stress, although evidence suggests they may be more resistant to acute hypoxia-induced redox balance alterations. We aimed to investigate the redox balance changes across a 3-day hypobaric hypoxic exposure at 3375 m in healthy adults born preterm(gestational age ≤ 32 weeks) and their term-born(gestational age ≥ 38 weeks)counterparts.Methods: Resting venous blood was obtained in normoxia(prior to altitude exposure), immediately upon arrival to altitude, and the following 3mornings. Antioxidant(superoxide dismutase(SOD), catalase, glutathione peroxidase(GPx), and ferric reducing antioxidant power(FRAP)),pro-oxidant(xanthine oxidase(XO) and myeloperoxidase(MPO)) enzyme activity, oxidative stress markers(advanced oxidation protein product(AOPP) and malondialdehyde(MDA)), nitric oxide(NO) metabolites(nitrites, nitrates, and total nitrite and nitrate(NOx)), and nitrotyrosine were measured in plasma.Results: SOD increased only in the preterm group(p < 0.05). Catalase increased at arrival in preterm group(p < 0.05). XO activity increased at Day 3 for the preterm group, while it increased acutely(arrival and Day 1) in control group. MPO increased in both groups throughout the3 days(p < 0.05). AOPP only increased at arrival in the preterm(p < 0.05) whereas it decreased at arrival up to Day 3(p < 0.05) for control.MDA decreased in control group from arrival onward. Nitrotyrosine decreased in both groups(p < 0.05). Nitrites increased on Day 3(p < 0.05)in control group and decreased on Day 1(p < 0.05) in preterm group.Conclusion: These data indicate that antioxidant enzymes seem to increase immediately upon hypoxic exposure in preterm adults. Conversely, the blunted pro-oxidant enzyme response to prolonged hypoxia exposure suggests that these enzymes may be less sensitive in preterm individuals.These findings lend further support to the potential hypoxic preconditioning effect of preterm birth.
文摘While different species in nature have safely solved the problem of navigation in a dynamic environment, this remains a challenging task for researchers around the world. The paper addresses the problem of autonomous navigation in an unknown dynamic environment for a single and a group of three wheeled omnidirectional mobile robots(TWOMRs). The robot has to track a dynamic target while avoiding dynamic obstacles and dynamic walls in an unknown and very dense environment. It adopts a behavior-based controller that consists of four behaviors: "target tracking", "obstacle avoidance", "dynamic wall following" and "avoid robots". The paper considers the problem of kinematic saturation. In addition, it introduces a strategy for predicting the velocity of dynamic obstacles based on two successive measurements of the ultrasonic sensors to calculate the velocity of the obstacle expressed in the sensor frame. Furthermore, the paper proposes a strategy to deal with dynamic walls even when they have U-like or V-like shapes. The approach can also deal with the formation control of a group of robots based on the leader-follower structure and the behavior-based control, where the robots have to get together and maintain a given formation while navigating toward the target, avoiding obstacles and walls in a dynamic environment. The effectiveness of the proposed approaches is demonstrated via simulation.
基金Supported by the China-Slovenia Intergovernmental Science and Technology Cooperation and Exchange Project(2017-21-12-16)China-Serbia Intergovernmental Science and Technology Cooperation and Exchange Project(266-3-1).
文摘Based on domain specified language mechanism(DSLM),the architecture of the robotic training system for the rehabilitation of children with cerebral palsy(CP)is designed.Application of human-computer interaction(HCI)motion recognition technology is combined with Kinect to improve the effect of cerebral palsy rehabilitation training.In this system,Kinect's bone recognition method is used to judge the patient's training movements,and the collected bone movement information is judged.The human-computer interaction function is based on the Microsoft foundation classes function of Visual Studio based on DSLM development,which can realize real-time interactive training and evaluation of people and actions,and record the training information of patients.The system combines the designed small game to train the upper limb movement ability and reaction ability of the cerebral palsy patient,and provides key technology for improving the cerebral palsy rehabilitation training system.
文摘In this paper, we describe an algorithm that performs automatic detection and tracking of astral microtubules in fluorescence confocal images. This sub-population of microtubules only exists during and immediately before mitosis and aids in the spindle orientation by connecting it to the cell cortex. Anomalies in their dynamic behaviour play a causal role in many diseases, such as development disorders and cancer. The main novelty of the proposed algorithm lies in the fact it provides a fully automated estimation of parameters related to microtubule dynamic instability (growth velocity, track length and track lifetime), and helps in understanding the effects of intermediate drug concentrations. Its performance has been objectively assessed using publicly available synthetic data and largely employed metrics. Moreover, we present experiments addressing cell cultures doped with different concentrations of taxol and nocodazole. Such drugs are known to suppress the microtubule dynamic instability, but their effects at intermediate concentrations are not completely assessed. The algorithm has been compared with other state-of-the-art approaches, tested on consistent real datasets. The results are encouraging in terms of performance, robustness and simplicity of use, and the algorithm is now routinely employed in our Department of Molecular Biotechnology.
基金the China-Serbia Intergovernmental Science and Technology Cooperation and Exchange Project(No.2021-4-19)China-Slovenia Intergovernmental Science and Technology Cooperation and Exchange Project(No.2017-21-12-16).
文摘Through the observation and analysis of the motion trajectory of spiral winding motion for slender legless biological creatures in water,V-REP software is adopted to build a dynamic simulator to study on the mechanism of spiral winding swimming(SWS)motion.By using the output of spiral function(SF),the dynamic simulation model of slender legless creature(SLC)realizes the SWS motion in water.The corresponding experiments under the control of different bending angle of SF to control the dynamic model are also carried out to analyze the water performance of SWS in still water.Combined with the output of two different bending angles of the spiral function,the dynamic model can be used to realize SWS and up/down motion.This work provides technical reserve and experimental platform for the corresponding study in related fields.
文摘In the paper the proposition of a discrete, robust, minimal energetic P servo controller for second order plant is presented. The plant under consideration is described with the use of a state space equation and a transfer function with interval parameters. The considered model describes for example an oriented PV （photovoltaic） system. As a controller a P （proportional） controller was applied. It is very simple and their application in the situation we deal with assures the suitable control performance. The controller is going to be implemented at digital platform. To construct the control system a cost function proposed by the authors was applied. It describes both the energy consumption and the sample time of controller. The proposed cost function is a function of plant parameters, describing the dynamics of the plant and controller parameters： proportional gain and sample time. For the cost function a simple geometric interpretation can be given： for fixed plant parameters and varying controller parameters it is a surface in the Ra plane. This fact can be applied to assign of optimal controller. Theoretical results were depicted by a numerical example.
基金supported by the Natural Sciences and Engineering Research Council of Canada(NSERC)
文摘State convergence is a novel control algorithm for bilateral teleoperation of robotic systems. First, it models the teleoperation system on state space and considers all the possible interactions between the master and slave systems. Second, it presents an elegant design procedure which requires a set of equations to be solved in order to compute the control gains of the bilateral loop. These design conditions are obtained by turning the master-slave error into an autonomous system and imposing the desired dynamic behavior of the teleoperation system. Resultantly, the convergence of master and slave states is achieved in a well-defined manner. The present study aims at achieving a similar convergence behavior offered by state convergence controller while reducing the number of variables sent across the communication channel. The proposal suggests transmitting composite master and slave variables instead of full master and slave states while keeping the operator's force channel intact. We show that,with these composite and force variables;it is indeed possible to achieve the convergence of states in a desired way by strictly following the method of state convergence. The proposal leads to a reduced complexity state convergence algorithm which is termed as composite state convergence controller. In order to validate the proposed scheme in the absence and presence of communication time delays, MATLAB simulations and semi-real time experiments are performed on a single degree-of-freedom teleoperation system.
文摘A method allowing a desirable matrix spectrum to be constructed as an alternative to the method using matrix transformation to the Frobenius form is stated. It can be applied to implement control algorithms for technical systems without executing the variables transformation procedures that are needed for deriving a Frobenius matrix. The method can be used for simulation of systems with different spectrums for choosing an alternative that satisfies to the distinct demands.
基金supported in part by the Ministry of Science and Innovation (Spain)(No. PID2021-126082OB-C22)。
文摘Wind turbine blades have been constantly increasing since wind energy becomes a popular renewable energy source to generate electricity. Therefore, the wind sector requires a more efficient and representative characterization of vertical wind speed profiles to assess the potential for a wind power plant site. This paper proposes an alternative characterization of vertical wind speed profiles based on Ward's agglomerative clustering algorithm, including both wind speed module and direction data. This approach gives a more accurate incoming wind speed variation around the rotor swept area, and subsequently, provides a more realistic and complete wind speed vector characterization for vertical profiles. Real wind database collected for 2018 in the Forschungsplattformen in Nordund Ostsee(FINO) research platform is used to assess the methodology. A preliminary pre-processing stage is proposed to select the appropriated number of heights and remove missing or incomplete data. Finally, two locations and four heights are selected, and 561588 wind data are characterized. Results and discussion are also included in this paper. The methodology can be applied to other wind database and locations to characterize vertical wind speed profiles and identify the most likely wind data vector patterns.
基金This research was supported by the National Key Research and Development Program of China(2016YED0201003)the Yunnan Academician Expert Workstation(Wang Maohua,Grant No.2015IC16)。
文摘Precision energy management is very important for sustainability development of solar greenhouses,since huge energy demand for agricultural production both in quantity and quality.A proactive energy management,according to the optimal energy utilization in a look-ahead period with weather prediction,is presented and tested in this research.A multi-input-multi-output linear model of the energy balance of solar greenhouses based on on-line identification system can simulate greenhouse behavior and allow for predictive control.The good time allocation of available solar energy can be achieved by intelligent use of controls,such as store/retrieve fans and ventilation windows,i.e.solar energy to warm up the air or to be stored in the storage elements(wall,soil,etc.)or to be exhausted to outside.The proactive energy management can select an optimal trajectory of air temperature for the forecasted weather period to minimize plants’thermal‘cost’defined by an‘expert’in terms of set-points for the specific crop.The selection of temperature trajectory is formulated as a generalized traveling salesman problem(GTSP)with precedence constraints and is solved by a genetic algorithm(GA)in this research.The simulation study showed good potential for energy saving and timely allocation to prevent excessive crop stress.The active control elements in addition to predefining and applying,within energy constraints,optimal climate in the greenhouse,it also reduces the energy deficit,i.e.the working hours of the‘heater’in the sustained freezing weather,as well as the ventilation hours,that is,more energy harvest in the warm days.This intelligent solar greenhouse management system is being migrated to the web for serving a‘customer base’in the Internet Plus era.The capacity,of the concrete ground CAUA system(CAUA is an abbreviations from both China Agricultural University and Agricultural University of Athens),to implement web‘updates’of criteria,open weather data and models,on which control actions are based,is what makes use of Cloud Data for closing the loop of an effective Internet of Things(IoT)system,based on MACQU(MAnagement and Control for QUality)technological platform.
