Pub Date : 2021-03-30DOI: 10.15406/iratj.2021.07.00223
P. Lohmander
A wolf-moose predator-prey system is defined as a nonlinear continuous time differential equation system. The parameters are estimated via a discretized approximation and empirical data from Isle Royale, USA, representing a 61 year period. All parameter estimates confirm the hypotheses and all P-values are below 5%. Possible dynamic equilibria are determined as explicit general functions of the parameters and as numerical values based on the empirical data. General dynamic properties of the system are determined via phase -plane analysis and nonlinear simulation. The nonlinear system is also linearized close to the single equilibrium with two strictly positive populations. The explicit equations of the time path of the linearized system are compared to the nonlinear simulation. Both methods give almost identical solutions close to the equilibrium. Far from the equilibrium, the time paths of the two methods deviate considerably. The solution is a stable converging spiral (center) (unstable diverging spiral) in case the system equilibrium prey population is located at a higher (the same) (lower) level than the population level that gives maximum sustainable net production. Based on the empirically determined expected parameter values, the system is stable but converges very slowly, as a spiral, to the two-species equilibrium. The estimated standard deviations of the parameters can be used to determine the probability that the system solution is a center or an unstable diverging spiral. The optimal management of the wolf-moose system is also determined via sustainable optimal control. Moose hunting and adjustments of the wolf population based on different prices and values of sustainable population levels are derived. Optimal hunting and stock levels are determined and reported as explicit functions of all parameters and prices.
{"title":"Dynamics, stability and sustainable optimal control in wolf-moose systems","authors":"P. Lohmander","doi":"10.15406/iratj.2021.07.00223","DOIUrl":"https://doi.org/10.15406/iratj.2021.07.00223","url":null,"abstract":"A wolf-moose predator-prey system is defined as a nonlinear continuous time differential equation system. The parameters are estimated via a discretized approximation and empirical data from Isle Royale, USA, representing a 61 year period. All parameter estimates confirm the hypotheses and all P-values are below 5%. Possible dynamic equilibria are determined as explicit general functions of the parameters and as numerical values based on the empirical data. General dynamic properties of the system are determined via phase -plane analysis and nonlinear simulation. The nonlinear system is also linearized close to the single equilibrium with two strictly positive populations. The explicit equations of the time path of the linearized system are compared to the nonlinear simulation. Both methods give almost identical solutions close to the equilibrium. Far from the equilibrium, the time paths of the two methods deviate considerably. The solution is a stable converging spiral (center) (unstable diverging spiral) in case the system equilibrium prey population is located at a higher (the same) (lower) level than the population level that gives maximum sustainable net production. Based on the empirically determined expected parameter values, the system is stable but converges very slowly, as a spiral, to the two-species equilibrium. The estimated standard deviations of the parameters can be used to determine the probability that the system solution is a center or an unstable diverging spiral. The optimal management of the wolf-moose system is also determined via sustainable optimal control. Moose hunting and adjustments of the wolf population based on different prices and values of sustainable population levels are derived. Optimal hunting and stock levels are determined and reported as explicit functions of all parameters and prices.","PeriodicalId":346234,"journal":{"name":"International Robotics & Automation Journal","volume":"2010 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127351811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-13DOI: 10.15406/iratj.2021.07.00218
R. Arulmurugan
The purpose of this article is to analysis various strategies for effective household energy conservation improvement because day by day energy scarcity increases one of third largest consumer is domestic consumer. The power wastage from the domestic consumer is increases abruptly. In this article deals what are different strategies uses to effectively utilize energy conservation for household applications. In the exciting various awareness programme provided by government even-though the power losses are never drop down. The drawback of these due to malfunctions of the equipment. In the proposed article various methods and strategies suggest to reduce the power consumption. The merits of the proposed system is the investment cost is too low, in particular point the investment cost is zero. The outcome of the proposed system helps the public to reduce the power loss and save the nations.
{"title":"Analysis of various strategies for effective household energy conservation","authors":"R. Arulmurugan","doi":"10.15406/iratj.2021.07.00218","DOIUrl":"https://doi.org/10.15406/iratj.2021.07.00218","url":null,"abstract":"The purpose of this article is to analysis various strategies for effective household energy conservation improvement because day by day energy scarcity increases one of third largest consumer is domestic consumer. The power wastage from the domestic consumer is increases abruptly. In this article deals what are different strategies uses to effectively utilize energy conservation for household applications. In the exciting various awareness programme provided by government even-though the power losses are never drop down. The drawback of these due to malfunctions of the equipment. In the proposed article various methods and strategies suggest to reduce the power consumption. The merits of the proposed system is the investment cost is too low, in particular point the investment cost is zero. The outcome of the proposed system helps the public to reduce the power loss and save the nations.","PeriodicalId":346234,"journal":{"name":"International Robotics & Automation Journal","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132644727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-08-31DOI: 10.15406/iratj.2020.06.00210
Mahmood Mazare, M. Taghizadeh, Pegah Ghaf G
In this paper, an Active Fault Tolerant Control (AFTC) strategy using a nonlinear H∞ control is proposed for a delta type parallel robot in the presence of actuator and sensor fault. First, dynamic modeling of the robot is accomplished using the Lagrange method. To measure the position and velocity, a super-twisting third-order sliding mode (STW-TOSM) observer is applied. The proposed scheme can accommodate both faults and uncertainties without velocity measurement. In addition, fast convergence and high accuracy is achieved because of applying the high-order sliding mode (HOSM) observer. In order to indicate the effectiveness of the FTC on the basis of nonlinear H∞, its performance is compared with conventional sliding mode and feedback linearization methods. The obtained results reveal the efficacy of the proposed FTC- H∞.
{"title":"Active fault tolerant control based on nonlinear subject to actuator and sensor faults for a parallel robot","authors":"Mahmood Mazare, M. Taghizadeh, Pegah Ghaf G","doi":"10.15406/iratj.2020.06.00210","DOIUrl":"https://doi.org/10.15406/iratj.2020.06.00210","url":null,"abstract":"In this paper, an Active Fault Tolerant Control (AFTC) strategy using a nonlinear H∞ control is proposed for a delta type parallel robot in the presence of actuator and sensor fault. First, dynamic modeling of the robot is accomplished using the Lagrange method. To measure the position and velocity, a super-twisting third-order sliding mode (STW-TOSM) observer is applied. The proposed scheme can accommodate both faults and uncertainties without velocity measurement. In addition, fast convergence and high accuracy is achieved because of applying the high-order sliding mode (HOSM) observer. In order to indicate the effectiveness of the FTC on the basis of nonlinear H∞, its performance is compared with conventional sliding mode and feedback linearization methods. The obtained results reveal the efficacy of the proposed FTC- H∞.","PeriodicalId":346234,"journal":{"name":"International Robotics & Automation Journal","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122907329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.15406/iratj.2022.08.00244
Mi Lu
Modern systems demand high computational power within limited resources. Approximate computing is a promising approach to design arithmetic units with tight resources for error-tolerant applications such as image and signal processing and computer vision. A floating-point multiplier is one of the arithmetic units with the highest complexity in such applications. Designing a floating-point multiplier based on the approximate computing technique can reduce its complexity as well as increase performance and energy efficiency. However, an unknown error rate for upcoming input data is problematic to design appropriate approximate multipliers. The existing solution is to utilize an error estimator relying on statistical analysis. In this paper, we propose new approximate floating-point multipliers based on an accumulator and reconfigurable adders with an error estimator. Unlike previous designs, our proposed designs are able to change the levels of accuracy at runtime. Thus, we can make errors distributed more evenly. In contrast to other designs, our proposed design can maximize the performance gain since reconfigurable multipliers are able to operate two multiplications in parallel once the low accuracy mode is selected. Furthermore, we apply a simple rounding technique to approximate floating-point multipliers for additional improvement. Our simulation results reveal that our new method can reduce area by 70.98% when error tolerance margin of our target application is 5%, and when its error tolerance margin is 3%, our rounding enhanced simple adders-based approximate multiplier can save area by 65.9%, and our reconfigurable adder-based approximate multiplier with rounding can save the average delay and energy by 54.95% and 46.67% respectively compared to an exact multiplier.
{"title":"Runtime accuracy alterable approximate floatingpoint multipliers","authors":"Mi Lu","doi":"10.15406/iratj.2022.08.00244","DOIUrl":"https://doi.org/10.15406/iratj.2022.08.00244","url":null,"abstract":"Modern systems demand high computational power within limited resources. Approximate computing is a promising approach to design arithmetic units with tight resources for error-tolerant applications such as image and signal processing and computer vision. A floating-point multiplier is one of the arithmetic units with the highest complexity in such applications. Designing a floating-point multiplier based on the approximate computing technique can reduce its complexity as well as increase performance and energy efficiency. However, an unknown error rate for upcoming input data is problematic to design appropriate approximate multipliers. The existing solution is to utilize an error estimator relying on statistical analysis. In this paper, we propose new approximate floating-point multipliers based on an accumulator and reconfigurable adders with an error estimator. Unlike previous designs, our proposed designs are able to change the levels of accuracy at runtime. Thus, we can make errors distributed more evenly. In contrast to other designs, our proposed design can maximize the performance gain since reconfigurable multipliers are able to operate two multiplications in parallel once the low accuracy mode is selected. Furthermore, we apply a simple rounding technique to approximate floating-point multipliers for additional improvement. Our simulation results reveal that our new method can reduce area by 70.98% when error tolerance margin of our target application is 5%, and when its error tolerance margin is 3%, our rounding enhanced simple adders-based approximate multiplier can save area by 65.9%, and our reconfigurable adder-based approximate multiplier with rounding can save the average delay and energy by 54.95% and 46.67% respectively compared to an exact multiplier.","PeriodicalId":346234,"journal":{"name":"International Robotics & Automation Journal","volume":"129 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132658415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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