Pub Date : 2019-10-01DOI: 10.1109/ICMECT.2019.8932101
Florian Biesinger, M. Weyrich
The digital twin is a great term that is frequently used in the context of digitalization and Industry 4.0. In discussions with other researchers and colleagues about the digital twin, it oftentimes becomes clear that everyone understands something different about the digital twin. This paper therefore compares the different facets of digital twins in the industrial environment of production. Different applications are shown, and a list of added values of a digital twin is derived based on these applications. The paper also covers the different facets of digital twins in the automotive industry and evaluates their practical benefits. In addition, the different technologies for realizing a digital twin are examined, and a concept for modeling the lifecycle of a production line via the digital twin is presented.
{"title":"The Facets of Digital Twins in Production and the Automotive Industry","authors":"Florian Biesinger, M. Weyrich","doi":"10.1109/ICMECT.2019.8932101","DOIUrl":"https://doi.org/10.1109/ICMECT.2019.8932101","url":null,"abstract":"The digital twin is a great term that is frequently used in the context of digitalization and Industry 4.0. In discussions with other researchers and colleagues about the digital twin, it oftentimes becomes clear that everyone understands something different about the digital twin. This paper therefore compares the different facets of digital twins in the industrial environment of production. Different applications are shown, and a list of added values of a digital twin is derived based on these applications. The paper also covers the different facets of digital twins in the automotive industry and evaluates their practical benefits. In addition, the different technologies for realizing a digital twin are examined, and a concept for modeling the lifecycle of a production line via the digital twin is presented.","PeriodicalId":309525,"journal":{"name":"2019 23rd International Conference on Mechatronics Technology (ICMT)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114983548","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 : 2019-10-01DOI: 10.1109/ICMECT.2019.8932103
S. Yun, Yang-Lae Lee, H. A. Khan, C. Kang, Y. Ham, Jung-Ho Park
This paper deals with a proportional flow control valve for construction vehicle. The proportional flow control valve consists of an electrohydraulic proportional reducing(EPPR) valve and a flow control valve. In this study, static and dynamic characteristics of the proportional flow control valve, suggested for use in excavators, were investigated using experiments, and performance related parameters are discussed.
{"title":"Proportional Flow Control Valve for Construction Vehicle","authors":"S. Yun, Yang-Lae Lee, H. A. Khan, C. Kang, Y. Ham, Jung-Ho Park","doi":"10.1109/ICMECT.2019.8932103","DOIUrl":"https://doi.org/10.1109/ICMECT.2019.8932103","url":null,"abstract":"This paper deals with a proportional flow control valve for construction vehicle. The proportional flow control valve consists of an electrohydraulic proportional reducing(EPPR) valve and a flow control valve. In this study, static and dynamic characteristics of the proportional flow control valve, suggested for use in excavators, were investigated using experiments, and performance related parameters are discussed.","PeriodicalId":309525,"journal":{"name":"2019 23rd International Conference on Mechatronics Technology (ICMT)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130040393","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 : 2019-10-01DOI: 10.1109/ICMECT.2019.8932131
Vincent Y. Philippart, Kristian O. Snel, Antoine M. de Waal, J. Jeedella, E. Najafi
Self-balancing robot control is a common way to challenge students in control-oriented courses to stabilize an unstable, non-linear dynamic system. This paper presents an application of model-based design on a self-balancing robot using the Arduino Due micro-controller board. The system consists of a set DC-motors with quadrature encoders, a nine degree of freedom (9-DOF), a Bluetooth module, a motor controller and a micro-controller. By utilizing cheap off-the-shelf hardware and applying model-based design techniques and simulations an accessible learning environment is created. Both the PID and LQR controllers will be discussed for their educational value.
{"title":"Model-Based Design for a Self-Balancing Robot using the Arduino Micro-Controller Board","authors":"Vincent Y. Philippart, Kristian O. Snel, Antoine M. de Waal, J. Jeedella, E. Najafi","doi":"10.1109/ICMECT.2019.8932131","DOIUrl":"https://doi.org/10.1109/ICMECT.2019.8932131","url":null,"abstract":"Self-balancing robot control is a common way to challenge students in control-oriented courses to stabilize an unstable, non-linear dynamic system. This paper presents an application of model-based design on a self-balancing robot using the Arduino Due micro-controller board. The system consists of a set DC-motors with quadrature encoders, a nine degree of freedom (9-DOF), a Bluetooth module, a motor controller and a micro-controller. By utilizing cheap off-the-shelf hardware and applying model-based design techniques and simulations an accessible learning environment is created. Both the PID and LQR controllers will be discussed for their educational value.","PeriodicalId":309525,"journal":{"name":"2019 23rd International Conference on Mechatronics Technology (ICMT)","volume":"138 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124353390","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 : 2019-10-01DOI: 10.1109/ICMECT.2019.8932126
Meghdeep Jana, B. Barua, S. Hazarika
Robotic devices can accelerate the rehabilitation process of an impaired patient by increasing the frequency of treatment and eliminating the need for a physiotherapist. This paper presents the development of a novel human finger exoskeleton for the motor rehabilitation of post-stroke patients by providing assistance-as-required support to patients in active flexion of the finger. The proposed design comprises of a two degrees of freedom, seven-link concatenated mechanism with two links attached to proximal and distal phalanges and actuated by two electric linear actuators for compact size. We synthesized the mechanism on an interactive geometry software to make the mechanism follow natural joint trajectories. Kinematic analysis of the exoskeleton showed very low deviation from ideal trajectory and finite element analyses showed good structural rigidity under maximum load conditions. The paper further describes the electro-mechanical system and software architecture of the prototype. The prototype makes use of electromyography signal to detect human intention and has the ability to provide assistance-as-required rehabilitation through a developed intention based control algorithm. The algorithm makes use of signal processing and statistical techniques to recognise patterns from electromyography data. A classifier was modelled with human intention detection accuracy of nearly 90% The results of the testing on real human finger demonstrate the potential for clinical applications in the robot-assisted rehabilitation of the human hand for grasping tasks.
{"title":"Design and Development of a Finger Exoskeleton for Motor Rehabilitation using Electromyography Signals","authors":"Meghdeep Jana, B. Barua, S. Hazarika","doi":"10.1109/ICMECT.2019.8932126","DOIUrl":"https://doi.org/10.1109/ICMECT.2019.8932126","url":null,"abstract":"Robotic devices can accelerate the rehabilitation process of an impaired patient by increasing the frequency of treatment and eliminating the need for a physiotherapist. This paper presents the development of a novel human finger exoskeleton for the motor rehabilitation of post-stroke patients by providing assistance-as-required support to patients in active flexion of the finger. The proposed design comprises of a two degrees of freedom, seven-link concatenated mechanism with two links attached to proximal and distal phalanges and actuated by two electric linear actuators for compact size. We synthesized the mechanism on an interactive geometry software to make the mechanism follow natural joint trajectories. Kinematic analysis of the exoskeleton showed very low deviation from ideal trajectory and finite element analyses showed good structural rigidity under maximum load conditions. The paper further describes the electro-mechanical system and software architecture of the prototype. The prototype makes use of electromyography signal to detect human intention and has the ability to provide assistance-as-required rehabilitation through a developed intention based control algorithm. The algorithm makes use of signal processing and statistical techniques to recognise patterns from electromyography data. A classifier was modelled with human intention detection accuracy of nearly 90% The results of the testing on real human finger demonstrate the potential for clinical applications in the robot-assisted rehabilitation of the human hand for grasping tasks.","PeriodicalId":309525,"journal":{"name":"2019 23rd International Conference on Mechatronics Technology (ICMT)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129163655","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 : 2019-10-01DOI: 10.1109/ICMECT.2019.8932122
A. Andreev, O. Peregudova, Katherine Sutyrkina, Elena Filatkina
In the paper, the global trajectory tracking control problem of a wheeled mobile robot is considered. Dynamical model of the robot consists of a platform, castor wheel and two rear wheels. The motion control of the robot is carried out by supplying voltage to DC motors which are installed in the axles of the rear wheels. An output feedback controller has been constructed using a backstepping design procedure and Lyapunov approach.
{"title":"On Global Output Feedback Trajectory Tracking Control of a Wheeled Mobile Robot","authors":"A. Andreev, O. Peregudova, Katherine Sutyrkina, Elena Filatkina","doi":"10.1109/ICMECT.2019.8932122","DOIUrl":"https://doi.org/10.1109/ICMECT.2019.8932122","url":null,"abstract":"In the paper, the global trajectory tracking control problem of a wheeled mobile robot is considered. Dynamical model of the robot consists of a platform, castor wheel and two rear wheels. The motion control of the robot is carried out by supplying voltage to DC motors which are installed in the axles of the rear wheels. An output feedback controller has been constructed using a backstepping design procedure and Lyapunov approach.","PeriodicalId":309525,"journal":{"name":"2019 23rd International Conference on Mechatronics Technology (ICMT)","volume":"55 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128003973","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 : 2019-10-01DOI: 10.1109/ICMECT.2019.8932144
Florian Biesinger, Benedikt Kraß, M. Weyrich
This paper highlights the necessity for a digital twin of production systems in the automotive industry. The survey on the use case of a digital twin of the production line is conducted with the production planning department of a major automobile manufacturer. The central part of the paper describes the current and future challenges for production planners in integration planning, which are determined by a survey. There are new trends in the automotive industry identified as a result of this survey. The study identifies exactly the information required by a digital twin of the production plant to improve the integration planning process. Furthermore, this survey provides answers to the benefits of integration planning by an automatically generated digital twin.
{"title":"A Survey on the Necessity for a Digital Twin of Production in the Automotive Industry","authors":"Florian Biesinger, Benedikt Kraß, M. Weyrich","doi":"10.1109/ICMECT.2019.8932144","DOIUrl":"https://doi.org/10.1109/ICMECT.2019.8932144","url":null,"abstract":"This paper highlights the necessity for a digital twin of production systems in the automotive industry. The survey on the use case of a digital twin of the production line is conducted with the production planning department of a major automobile manufacturer. The central part of the paper describes the current and future challenges for production planners in integration planning, which are determined by a survey. There are new trends in the automotive industry identified as a result of this survey. The study identifies exactly the information required by a digital twin of the production plant to improve the integration planning process. Furthermore, this survey provides answers to the benefits of integration planning by an automatically generated digital twin.","PeriodicalId":309525,"journal":{"name":"2019 23rd International Conference on Mechatronics Technology (ICMT)","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121496762","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 : 2019-10-01DOI: 10.1109/ICMECT.2019.8932156
Y. Mohamadi, E. I. Konukseven, A. Koku
This paper addresses the obstacle avoidance performance of a tele-operated wheeled mobile robot. The robot is equipped with both a camera and a laser range sensor to acquire the necessary data from the surrounding. The communication between the operator and the robot is established by means of a force-feedback haptic joystick. In order to tackle go-to-goal and obstacle avoidance tasks, behavior-based control methodology has been used. The results of the study show that the proposed cooperative control approach is superior to both fully manual and fully autonomous behavior-based control in terms of number of collisions, time consumed to accomplish the tasks and also the cognitive pressure on the operator.
{"title":"Behavior-Based Approach for Cooperative Control of a Haptic-Driven Mobile Robot","authors":"Y. Mohamadi, E. I. Konukseven, A. Koku","doi":"10.1109/ICMECT.2019.8932156","DOIUrl":"https://doi.org/10.1109/ICMECT.2019.8932156","url":null,"abstract":"This paper addresses the obstacle avoidance performance of a tele-operated wheeled mobile robot. The robot is equipped with both a camera and a laser range sensor to acquire the necessary data from the surrounding. The communication between the operator and the robot is established by means of a force-feedback haptic joystick. In order to tackle go-to-goal and obstacle avoidance tasks, behavior-based control methodology has been used. The results of the study show that the proposed cooperative control approach is superior to both fully manual and fully autonomous behavior-based control in terms of number of collisions, time consumed to accomplish the tasks and also the cognitive pressure on the operator.","PeriodicalId":309525,"journal":{"name":"2019 23rd International Conference on Mechatronics Technology (ICMT)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132834738","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 : 2019-10-01DOI: 10.1109/ICMECT.2019.8932153
Shohei Nakama, Tatsuki Ikari, Hidetake Tanaka
In the study, a novel design and fabrication method, which is simple and optimizes press moulding for CFRP based on CAD data was proposed and assessed. CFRP has come into widespread use for weight reduction of transportation equipment in recent years. However, in order to expand the range of their purpose, reduction of the production cost and increasing the molding cycle is necessary. The author focused on press molding technique to achieve this. In the case of press molding CFRP, partial buckling or fracture of the fiber occurs due to a dragged fiber caused by deforming force. As a solution to this problem, the author has used design and fabrication method for CFRP preform. In the previous research, unfolding methodology of a three-dimensional shape to a plane surface based on CAD/CAM system, which enables generation of an unfolding diagram which maintains continuity of fiber tow was proposed. Furthermore, validity of unfolded diagram had been confirmed by reproducing the objective three-dimensional shape from the unfolded diagram using CFRTS tow prepreg. In this study, CFRTP sheet were molded by using press molding to decrease the tact time for aesthetic surface.
{"title":"Development of Press Molding Method with Unfolded Diagram for CFRP","authors":"Shohei Nakama, Tatsuki Ikari, Hidetake Tanaka","doi":"10.1109/ICMECT.2019.8932153","DOIUrl":"https://doi.org/10.1109/ICMECT.2019.8932153","url":null,"abstract":"In the study, a novel design and fabrication method, which is simple and optimizes press moulding for CFRP based on CAD data was proposed and assessed. CFRP has come into widespread use for weight reduction of transportation equipment in recent years. However, in order to expand the range of their purpose, reduction of the production cost and increasing the molding cycle is necessary. The author focused on press molding technique to achieve this. In the case of press molding CFRP, partial buckling or fracture of the fiber occurs due to a dragged fiber caused by deforming force. As a solution to this problem, the author has used design and fabrication method for CFRP preform. In the previous research, unfolding methodology of a three-dimensional shape to a plane surface based on CAD/CAM system, which enables generation of an unfolding diagram which maintains continuity of fiber tow was proposed. Furthermore, validity of unfolded diagram had been confirmed by reproducing the objective three-dimensional shape from the unfolded diagram using CFRTS tow prepreg. In this study, CFRTP sheet were molded by using press molding to decrease the tact time for aesthetic surface.","PeriodicalId":309525,"journal":{"name":"2019 23rd International Conference on Mechatronics Technology (ICMT)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129786035","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 : 2019-10-01DOI: 10.1109/ICMECT.2019.8932146
Rainer Müller, M. Scholer, Anne Blum, A. Kanso
Dynamic and kinematic parameters of the robot's tool are essential to build an accurate model of the robot. This has an impact on the behaviour of the latter. The identification of the kinematic parameters is solved by different conventional methods [1]. On the other hand, the identification of the dynamic parameters is more complex and requires the integration of additional sensors, e.g. force/torque sensors. Given that conventional methods suffer from high inaccuracies, this paper deals with the determination of the dynamic parameters based on a reference measurement to improve the accuracy. Therefore, static and dynamic methods are introduced. By the static method, the robot moves to predefined configurations and avoids continuous and unpredictable movements, whereas the dynamic method is based on a continuous rotation about a predefined axis. A comparison and a validation are carried out in an experimental setup.
{"title":"Identification of the Dynamic Parameters of a Robotic Tool Based on Integrated Torque Sensors","authors":"Rainer Müller, M. Scholer, Anne Blum, A. Kanso","doi":"10.1109/ICMECT.2019.8932146","DOIUrl":"https://doi.org/10.1109/ICMECT.2019.8932146","url":null,"abstract":"Dynamic and kinematic parameters of the robot's tool are essential to build an accurate model of the robot. This has an impact on the behaviour of the latter. The identification of the kinematic parameters is solved by different conventional methods [1]. On the other hand, the identification of the dynamic parameters is more complex and requires the integration of additional sensors, e.g. force/torque sensors. Given that conventional methods suffer from high inaccuracies, this paper deals with the determination of the dynamic parameters based on a reference measurement to improve the accuracy. Therefore, static and dynamic methods are introduced. By the static method, the robot moves to predefined configurations and avoids continuous and unpredictable movements, whereas the dynamic method is based on a continuous rotation about a predefined axis. A comparison and a validation are carried out in an experimental setup.","PeriodicalId":309525,"journal":{"name":"2019 23rd International Conference on Mechatronics Technology (ICMT)","volume":"133 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130701336","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 : 2019-10-01DOI: 10.1109/ICMECT.2019.8932142
Muhammed Si̇pahi̇, Abdurrahman Yilmaz, A. Kaya, Ata Ertug Cil, A. A. Demircali, H. Uvet
In this study, design of flapping wing mini air vehicle (FWMAV) and comparison of wing designs which are chosen with respect to mass parameters are investigated. Wing shape and aspect ratio (AR) affects are observed by using finite element method (FEM) in COMSOL®. To examine thrust of our mechanism for one cycle flapping motion, FEM and empirical formulations are used. Calculation steps of a relationship between wing design parameters and mass of the system are presented. These relations are originated from bird's nature. The flapping wing motion is achieved via a crank-rocker mechanism that generates harmonic flap function. These simulations are made for three different wings whose wing area, wing span and flapping frequency are same. We observed the effect of wing geometry over lift force by comparing wing design. The result of empirical calculation and simulation values show that there is a payload loss of %7 via empirical formulations.
{"title":"Design of Flapping Wing Mini Air Vehicle with Crank-Rocker Mechanism","authors":"Muhammed Si̇pahi̇, Abdurrahman Yilmaz, A. Kaya, Ata Ertug Cil, A. A. Demircali, H. Uvet","doi":"10.1109/ICMECT.2019.8932142","DOIUrl":"https://doi.org/10.1109/ICMECT.2019.8932142","url":null,"abstract":"In this study, design of flapping wing mini air vehicle (FWMAV) and comparison of wing designs which are chosen with respect to mass parameters are investigated. Wing shape and aspect ratio (AR) affects are observed by using finite element method (FEM) in COMSOL®. To examine thrust of our mechanism for one cycle flapping motion, FEM and empirical formulations are used. Calculation steps of a relationship between wing design parameters and mass of the system are presented. These relations are originated from bird's nature. The flapping wing motion is achieved via a crank-rocker mechanism that generates harmonic flap function. These simulations are made for three different wings whose wing area, wing span and flapping frequency are same. We observed the effect of wing geometry over lift force by comparing wing design. The result of empirical calculation and simulation values show that there is a payload loss of %7 via empirical formulations.","PeriodicalId":309525,"journal":{"name":"2019 23rd International Conference on Mechatronics Technology (ICMT)","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130648944","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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