Pub Date : 2019-03-06DOI: 10.4236/OJMSI.2019.72007
A. White, D. Nielsen, M. Censlive
This paper describes a control theoretical model of collaborative value development. This model is designed to assist managers in choosing parameters that are critical to the development process in service design and support their Business Model. This methodology uses control system modelling of web-based service value generation implemented in SIMULINK/MATLAB. An application based on public domain Wikipedia data is used to validate and develop the model. A control theoretic model applied to the creation of Wikipedia articles shows very good agreement with Wikipedia published data for the time dependent growth in articles produced, and editors used, well within the variability of parametric data listed publically justifying the principle equations used in the model. This development and fine tuning of the model has been limited by the publically available data. To obtain a more accurate model in this area would need the co-operation of web service organisations to reveal confidential data. This modelling procedure can produce a decision support process for service design and could, with modification be applied much more widely to other choices in service design/implementation, even allowing for user contribution to be evaluated. This work shows how subjective judgements on value and other intangibles need to be continually re-evaluated. Such methodology has not been applied elsewhere to value generation applications. It could be used to rank contributions from co-creators for reward sharing.
{"title":"A Control Theoretical Model of Web Service Value Development","authors":"A. White, D. Nielsen, M. Censlive","doi":"10.4236/OJMSI.2019.72007","DOIUrl":"https://doi.org/10.4236/OJMSI.2019.72007","url":null,"abstract":"This paper describes a control theoretical model of collaborative value development. This model is designed to assist managers in choosing parameters that are critical to the development process in service design and support their Business Model. This methodology uses control system modelling of web-based service value generation implemented in SIMULINK/MATLAB. An application based on public domain Wikipedia data is used to validate and develop the model. A control theoretic model applied to the creation of Wikipedia articles shows very good agreement with Wikipedia published data for the time dependent growth in articles produced, and editors used, well within the variability of parametric data listed publically justifying the principle equations used in the model. This development and fine tuning of the model has been limited by the publically available data. To obtain a more accurate model in this area would need the co-operation of web service organisations to reveal confidential data. This modelling procedure can produce a decision support process for service design and could, with modification be applied much more widely to other choices in service design/implementation, even allowing for user contribution to be evaluated. This work shows how subjective judgements on value and other intangibles need to be continually re-evaluated. Such methodology has not been applied elsewhere to value generation applications. It could be used to rank contributions from co-creators for reward sharing.","PeriodicalId":56990,"journal":{"name":"建模与仿真(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45685745","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 : 2019-03-06DOI: 10.4236/OJMSI.2019.72005
L. N. Nkamba, Thomas Timothee Manga, N. Sakamoto
This paper focuses on the study and control of a non-linear mathematical epidemic model ( SSvihVELI ) based on a system of ordinary differential equation modeling the spread of tuberculosis infectious with HIV/AIDS coinfection. Existence of both disease free equilibrium and endemic equilibrium is discussed. Reproduction number R0 is determined. Using Lyapunov-Lasalle methods, we analyze the stability of epidemic system around the equilibriums (disease free and endemic equilibrium). The global asymptotic stability of the disease free equilibrium whenever Rvac < 1 is proved, where R0 is the reproduction number. We prove also that when R0 is less than one, tuberculosis can be eradicated. Numerical simulations are conducted to approve analytic results. To achieve control of the disease, seeking to reduce the infectious group by the minimum vaccine coverage, a control problem is formulated. The Pontryagin’s maximum principle is used to characterize the optimal control. The optimality system is derived and solved numerically using the Runge Kutta fourth procedure.
{"title":"Stability and Optimal Control of Tuberculosis Spread with an Imperfect Vaccine in the Case of Co-Infection with HIV","authors":"L. N. Nkamba, Thomas Timothee Manga, N. Sakamoto","doi":"10.4236/OJMSI.2019.72005","DOIUrl":"https://doi.org/10.4236/OJMSI.2019.72005","url":null,"abstract":"This paper focuses on the study and control of a non-linear mathematical epidemic model ( SSvihVELI ) based on a system of ordinary differential equation modeling the spread of tuberculosis infectious with HIV/AIDS coinfection. Existence of both disease free equilibrium and endemic equilibrium is discussed. Reproduction number R0 is determined. Using Lyapunov-Lasalle methods, we analyze the stability of epidemic system around the equilibriums (disease free and endemic equilibrium). The global asymptotic stability of the disease free equilibrium whenever Rvac < 1 is proved, where R0 is the reproduction number. We prove also that when R0 is less than one, tuberculosis can be eradicated. Numerical simulations are conducted to approve analytic results. To achieve control of the disease, seeking to reduce the infectious group by the minimum vaccine coverage, a control problem is formulated. The Pontryagin’s maximum principle is used to characterize the optimal control. The optimality system is derived and solved numerically using the Runge Kutta fourth procedure.","PeriodicalId":56990,"journal":{"name":"建模与仿真(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47838588","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 : 2019-01-21DOI: 10.4236/ojmsi.2019.71004
Markos Abiso Erango, A. Goshu
Survival of HIV/AIDS patients is crucially dependent on comprehensive and targeted medical interventions such as supply of antiretroviral therapy and monitoring disease progression with CD4 T-cell counts. Statistical modelling approaches are helpful towards this goal. This study aims at developing Bayesian joint models with assumed generalized error distribution (GED) for the longitudinal CD4 data and two accelerated failure time distributions, Lognormal and loglogistic, for the survival time of HIV/AIDS patients. Data are obtained from patients under antiretroviral therapy follow-up at Shashemene referral hospital during January 2006-January 2012 and at Bale Robe general hospital during January 2008-March 2015. The Bayesian joint models are defined through latent variables and association parameters and with specified non-informative prior distributions for the model parameters. Simulations are conducted using Gibbs sampler algorithm implemented in the WinBUGS software. The results of the analyses of the two different data sets show that distributions of measurement errors of the longitudinal CD4 variable follow the generalized error distribution with fatter tails than the normal distribution. The Bayesian joint GED loglogistic models fit better to the data sets compared to the lognormal cases. Findings reveal that patients’ health can be improved over time. Compared to the males, female patients gain more CD4 counts. Survival time of a patient is negatively affected by TB infection. Moreover, increase in number of opportunistic infection implies decline of CD4 counts. Patients’ age negatively affects the disease marker with no effects on survival time. Improving weight may improve survival time of patients. Bayesian joint models with GED and AFT distributions are found to be useful in modelling the longitudinal and survival processes. Thus we recommend the generalized error distributions for measurement errors of the longitudinal data under the Bayesian joint modelling. Further studies may investigate the models with various types of shared random effects and more covariates with predictions.
{"title":"Bayesian Joint Modelling of Survival Time and Longitudinal CD4 Cell Counts Using Accelerated Failure Time and Generalized Error Distributions","authors":"Markos Abiso Erango, A. Goshu","doi":"10.4236/ojmsi.2019.71004","DOIUrl":"https://doi.org/10.4236/ojmsi.2019.71004","url":null,"abstract":"Survival of HIV/AIDS patients is crucially dependent on comprehensive and targeted medical interventions such as supply of antiretroviral therapy and monitoring disease progression with CD4 T-cell counts. Statistical modelling approaches are helpful towards this goal. This study aims at developing Bayesian joint models with assumed generalized error distribution (GED) for the longitudinal CD4 data and two accelerated failure time distributions, Lognormal and loglogistic, for the survival time of HIV/AIDS patients. Data are obtained from patients under antiretroviral therapy follow-up at Shashemene referral hospital during January 2006-January 2012 and at Bale Robe general hospital during January 2008-March 2015. The Bayesian joint models are defined through latent variables and association parameters and with specified non-informative prior distributions for the model parameters. Simulations are conducted using Gibbs sampler algorithm implemented in the WinBUGS software. The results of the analyses of the two different data sets show that distributions of measurement errors of the longitudinal CD4 variable follow the generalized error distribution with fatter tails than the normal distribution. The Bayesian joint GED loglogistic models fit better to the data sets compared to the lognormal cases. Findings reveal that patients’ health can be improved over time. Compared to the males, female patients gain more CD4 counts. Survival time of a patient is negatively affected by TB infection. Moreover, increase in number of opportunistic infection implies decline of CD4 counts. Patients’ age negatively affects the disease marker with no effects on survival time. Improving weight may improve survival time of patients. Bayesian joint models with GED and AFT distributions are found to be useful in modelling the longitudinal and survival processes. Thus we recommend the generalized error distributions for measurement errors of the longitudinal data under the Bayesian joint modelling. Further studies may investigate the models with various types of shared random effects and more covariates with predictions.","PeriodicalId":56990,"journal":{"name":"建模与仿真(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45416638","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 : 2019-01-01DOI: 10.4236/OJMSI.2019.71002
Katharina Renner-Martin, N. Brunner, M. Kühleitner, W. Nowak, K. Scheicher
The paper searched for raw data about wild-caught fish, where a sigmoidal growth function described the mass growth significantly better than non-sigmoidal functions. Specifically, von Bertalanffy’s sigmoidal growth function (metabolic exponent-pair a = 2/3, b = 1) was compared with unbounded linear growth and with bounded exponential growth using the Akaike information criterion. Thereby the maximum likelihood fits were compared, assuming a lognormal distribution of mass (i.e. a higher variance for heavier animals). Starting from 70+ size-at-age data, the paper focused on 15 data coming from large datasets. Of them, six data with 400 - 20,000 data-points were suitable for sigmoidal growth modeling. For these, a custom-made optimization tool identified the best fitting growth function from the general von Bertalanffy-Putter class of models. This class generalizes the well-known models of Verhulst (logistic growth), Gompertz and von Bertalanffy. Whereas the best-fitting models varied widely, their exponent-pairs displayed a remarkable pattern, as their difference was close to 1/3 (example: von Bertalanffy exponent-pair). This defined a new class of models, for which the paper provided a biological motivation that relates growth to food consumption.
{"title":"A Model for the Mass-Growth of Wild-Caught Fish","authors":"Katharina Renner-Martin, N. Brunner, M. Kühleitner, W. Nowak, K. Scheicher","doi":"10.4236/OJMSI.2019.71002","DOIUrl":"https://doi.org/10.4236/OJMSI.2019.71002","url":null,"abstract":"The paper searched for raw data about wild-caught fish, where a sigmoidal growth function described the mass growth significantly better than non-sigmoidal functions. Specifically, von Bertalanffy’s sigmoidal growth function (metabolic exponent-pair a = 2/3, b = 1) was compared with unbounded linear growth and with bounded exponential growth using the Akaike information criterion. Thereby the maximum likelihood fits were compared, assuming a lognormal distribution of mass (i.e. a higher variance for heavier animals). Starting from 70+ size-at-age data, the paper focused on 15 data coming from large datasets. Of them, six data with 400 - 20,000 data-points were suitable for sigmoidal growth modeling. For these, a custom-made optimization tool identified the best fitting growth function from the general von Bertalanffy-Putter class of models. This class generalizes the well-known models of Verhulst (logistic growth), Gompertz and von Bertalanffy. Whereas the best-fitting models varied widely, their exponent-pairs displayed a remarkable pattern, as their difference was close to 1/3 (example: von Bertalanffy exponent-pair). This defined a new class of models, for which the paper provided a biological motivation that relates growth to food consumption.","PeriodicalId":56990,"journal":{"name":"建模与仿真(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70368263","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 : 2019-01-01DOI: 10.4236/OJMSI.2019.71001
Garret Vo, Chiwoo Park
Public benchmark datasets have been widely used to evaluate multi-target tracking algorithms. Ideally, the benchmark datasets should include the video scenes of all scenarios that need to be tested. However, a limited amount of the currently available benchmark datasets does not comprehensively cover all necessary test scenarios. This limits the evaluation of multitarget tracking algorithms with various test scenarios. This paper introduced a computer simulation model that generates benchmark datasets for evaluating multi-target tracking algorithms with the complexity of multitarget tracking scenarios directly controlled by simulation inputs such as target birth and death rates, target movement, the rates of target merges and splits, target appearances, and image noise types and levels. The simulation model generated a simulated video and also provides the ground-truth target tracking for the simulated video, so the evaluation of multitarget tracking algorithms can be easily performed without any manual video annotation process. We demonstrated the use of the proposed simulation model for evaluating tracking-by-detection algorithms and filtering-based tracking algorithms.
{"title":"Computer Model for Evaluating Multi-Target Tracking Algorithms","authors":"Garret Vo, Chiwoo Park","doi":"10.4236/OJMSI.2019.71001","DOIUrl":"https://doi.org/10.4236/OJMSI.2019.71001","url":null,"abstract":"Public benchmark datasets have been widely used to evaluate multi-target tracking algorithms. Ideally, the benchmark datasets should include the video scenes of all scenarios that need to be tested. However, a limited amount of the currently available benchmark datasets does not comprehensively cover all necessary test scenarios. This limits the evaluation of multitarget tracking algorithms with various test scenarios. This paper introduced a computer simulation model that generates benchmark datasets for evaluating multi-target tracking algorithms with the complexity of multitarget tracking scenarios directly controlled by simulation inputs such as target birth and death rates, target movement, the rates of target merges and splits, target appearances, and image noise types and levels. The simulation model generated a simulated video and also provides the ground-truth target tracking for the simulated video, so the evaluation of multitarget tracking algorithms can be easily performed without any manual video annotation process. We demonstrated the use of the proposed simulation model for evaluating tracking-by-detection algorithms and filtering-based tracking algorithms.","PeriodicalId":56990,"journal":{"name":"建模与仿真(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70368254","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}
N. Hanajima, T. Kaneko, H. Kajiwara, Yoshinori Fujihira
In this paper, we investigate static stability for a doublespiral mobile robot. It is a new locomotion mechanism suitable for the wetlands that suppresses damage to vegetation and does not sink in the mud. The robot walks on the spirals, which play the role of footholds for the mobile robot. To overcome rough terrain locomotion, we need to ensure the stability of the walking motion on the sloping ground. In this study, we applied normalized energy stability margin (NESM) to the double-spiral mobile robot in order to investigate its static stability over rough terrain. The procedure to derived the NESM value were shown from the point of view of the vector calculation. In the numerical case study, we drew NESM maps to investigate the static stabilities when the inclination of the slope varied or the pose and orientation of the robot changed. We adopted a moment in the swing phase where the stability of the robot’s balance was easily lost. We found that the robot has sensitive directions in terms of stability. Planning the route and motion of the robot in the rough terrain could help maintain its stability.
{"title":"Static Stability of Double-Spiral Mobile Robot over Rough Terrain","authors":"N. Hanajima, T. Kaneko, H. Kajiwara, Yoshinori Fujihira","doi":"10.3384/ECP171421034","DOIUrl":"https://doi.org/10.3384/ECP171421034","url":null,"abstract":"In this paper, we investigate static stability for a doublespiral mobile robot. It is a new locomotion mechanism suitable for the wetlands that suppresses damage to vegetation and does not sink in the mud. The robot walks on the spirals, which play the role of footholds for the mobile robot. To overcome rough terrain locomotion, we need to ensure the stability of the walking motion on the sloping ground. In this study, we applied normalized energy stability margin (NESM) to the double-spiral mobile robot in order to investigate its static stability over rough terrain. The procedure to derived the NESM value were shown from the point of view of the vector calculation. In the numerical case study, we drew NESM maps to investigate the static stabilities when the inclination of the slope varied or the pose and orientation of the robot changed. We adopted a moment in the swing phase where the stability of the robot’s balance was easily lost. We found that the robot has sensitive directions in terms of stability. Planning the route and motion of the robot in the rough terrain could help maintain its stability.","PeriodicalId":56990,"journal":{"name":"建模与仿真(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75770973","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}
Recently, the super heavy aircraft A380 started operations between Mexico City and Paris, and it has been announced daily operations in March. In addition, Lufthansa and Emirates are also willing to use the A380 to operate from Frankfurt and Dubai to Mexico, respectively. However, in recent years, Mexico City International Airport has been reporting severe congestion problems and it is a concern whether these problems can be overcome with the current facilities and procedures together with the increasing aircraft demand. In this article, a capacity analysis of the operation performed in the airport is presented using information for a particular high-season day. A model-based approach which allows simulating the daily operation of the A380 is presented. This approach allows incorporating most of the restrictions besides the stochasticity inherent to the system.
{"title":"Make Space!: Disruption Analysis of the A380 Operation in Mexico City Airport","authors":"M. Mota, C. Zúñiga, Geert Boosten","doi":"10.3384/ECP17142293","DOIUrl":"https://doi.org/10.3384/ECP17142293","url":null,"abstract":"Recently, the super heavy aircraft A380 started operations between Mexico City and Paris, and it has been announced daily operations in March. In addition, Lufthansa and Emirates are also willing to use the A380 to operate from Frankfurt and Dubai to Mexico, respectively. However, in recent years, Mexico City International Airport has been reporting severe congestion problems and it is a concern whether these problems can be overcome with the current facilities and procedures together with the increasing aircraft demand. In this article, a capacity analysis of the operation performed in the airport is presented using information for a particular high-season day. A model-based approach which allows simulating the daily operation of the A380 is presented. This approach allows incorporating most of the restrictions besides the stochasticity inherent to the system.","PeriodicalId":56990,"journal":{"name":"建模与仿真(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72427343","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}
CO2-EOR is an attractive method because of its potential to increase the oil production from matured oilfields, at the same time reduce the carbon footprint from the industrial sources. The field response to the CO2-EOR technique depends on the petrophysical properties of the reservoir. Carbonate reservoirs are characterized by low permeability and strong heterogeneity, causing significant amounts of water and CO2 to be recycled when CO2 is re-injected into the reservoir. Naturally fractured carbonate reservoirs have low oil production, high water production, early water breakthrough and high water cut. This study focuses on the oil production and the CO2 recycle ratio in naturally fractured carbonate reservoirs, including near-well simulations using the reservoir software Rocx in combination with OLGA. The simulations indicate that closing the fractured zone causes delayed water breakthrough and dramatically reduced water cut, resulting in improved oil recovery as well as lower production and separation costs.
{"title":"Simulation of Oil Production in a Fractured Carbonate Reservoir","authors":"N. C. Furuvik, Britt M. E. Moldestad","doi":"10.3384/ECP17142842","DOIUrl":"https://doi.org/10.3384/ECP17142842","url":null,"abstract":"CO2-EOR is an attractive method because of its potential to increase the oil production from matured oilfields, at the same time reduce the carbon footprint from the industrial sources. The field response to the CO2-EOR technique depends on the petrophysical properties of the reservoir. Carbonate reservoirs are characterized by low permeability and strong heterogeneity, causing significant amounts of water and CO2 to be recycled when CO2 is re-injected into the reservoir. Naturally fractured carbonate reservoirs have low oil production, high water production, early water breakthrough and high water cut. This study focuses on the oil production and the CO2 recycle ratio in naturally fractured carbonate reservoirs, including near-well simulations using the reservoir software Rocx in combination with OLGA. The simulations indicate that closing the fractured zone causes delayed water breakthrough and dramatically reduced water cut, resulting in improved oil recovery as well as lower production and separation costs.","PeriodicalId":56990,"journal":{"name":"建模与仿真(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84450856","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}
A series of works such as harvesting and transporting in a farm is one of such works with so care as not to damage the harvest in order to maintain the value of harvests. We are developing an autonomous cart for gathering a harvest with the bed to be controlled to keep in horizontal level at work and in transit, in order to avoid harvests gathered in particular area of the bed and to keep away from being damaged in harvests. It is proposed a method of autonomous steering control of a harvest vehicle with maintaining the horizontal level of the bed of the cart with air cylinder suspension systems. It is shown that the problem of a level control of vehicle’s bed can be formulated as one of optimal control problems. Finally, its simulation study is considered.
{"title":"A Harvest Vehicle with Pneumatic Servo System for gathering a Harvest and its Simulation Study","authors":"K. Moriwaki","doi":"10.3384/ECP17142446","DOIUrl":"https://doi.org/10.3384/ECP17142446","url":null,"abstract":"A series of works such as harvesting and transporting in a farm is one of such works with so care as not to damage the harvest in order to maintain the value of harvests. We are developing an autonomous cart for gathering a harvest with the bed to be controlled to keep in horizontal level at work and in transit, in order to avoid harvests gathered in particular area of the bed and to keep away from being damaged in harvests. It is proposed a method of autonomous steering control of a harvest vehicle with maintaining the horizontal level of the bed of the cart with air cylinder suspension systems. It is shown that the problem of a level control of vehicle’s bed can be formulated as one of optimal control problems. Finally, its simulation study is considered.","PeriodicalId":56990,"journal":{"name":"建模与仿真(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81075355","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}
The utilization of dynamic Bayesian networks (DBNs) in simulation metamodeling enables the investigation of the time evolution of state variables of a simulation model. DBN metamodels have previously described the changes in the probability distribution of the simulation state by using a time slice structure in which the state variables are described at common time instants. In this paper, the novel approach to the determination of the time slice structure is introduced. It enables the selection of time instants of the DBN separately for each state variable. In this way, a more accurate metamodel representing multiple time scales of the variables is achieved. Furthermore, the construction is streamlined by presenting a dynamic programming algo-rithm for determining the key time instants for individual variables. The construction and use of the DBN metamodels are illustrated by an example problem dealing with the simulated operation of an air base.
{"title":"Simulation Metamodeling using Dynamic Bayesian Networks with Multiple Time Scales","authors":"Mikko Harju, Kai Virtanen, Jirka Poropudas","doi":"10.3384/ECP17142619","DOIUrl":"https://doi.org/10.3384/ECP17142619","url":null,"abstract":"The utilization of dynamic Bayesian networks (DBNs) in simulation metamodeling enables the investigation of the time evolution of state variables of a simulation model. DBN metamodels have previously described the changes in the probability distribution of the simulation state by using a time slice structure in which the state variables are described at common time instants. In this paper, the novel approach to the determination of the time slice structure is introduced. It enables the selection of time instants of the DBN separately for each state variable. In this way, a more accurate metamodel representing multiple time scales of the variables is achieved. Furthermore, the construction is streamlined by presenting a dynamic programming algo-rithm for determining the key time instants for individual variables. The construction and use of the DBN metamodels are illustrated by an example problem dealing with the simulated operation of an air base.","PeriodicalId":56990,"journal":{"name":"建模与仿真(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78577212","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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