João Nuno de Oliveira e Silva, L. Veiga, P. Ferreira
Mobile computing devices, such as mobile phones or even ultra-mobile PC's, are becoming more and more powerful. Because of this fact, users are starting to use these devices to execute tasks that until a few years ago would only be executed on a desktop PC, e.g. picture manipulation, or text editing. Furthermore, these devices, are by now almost continuously connected, either by Wi-Fi or 3G UMTS links. Nevertheless power consumption is still a major factor on these mobile devices usage, restricting autonomy. While users should be able to employ mobile computing devices to perform these tasks with convenience, it would improve performance and reduce battery drain if the bulk processing of such tasks could be offloaded to remote hosts accessible by the same user. To accomplish this, we present SPADE, a middleware to deploy remote and parallel execution of some commodity applications to solve complex problems, from mobile devices, without any special programming effort, and by simply defining several data input sets. In SPADE, jobs are composed of simpler tasks that will be executed on remote computers. The user states what files should be processed by each task, what application will be launched and defines the application arguments. By using SPADE any user can, for instance, accelerate a batch image manipulation by using otherwise idle remote computers, while releasing the mobile device for other tasks. In order to make SPADE usable by a wide set of computer users we implemented two ideas: i) the execution code is a commodity piece of software already installed on the remote computers (e.g. image processing applications), and ii) the definition of the data sets to be remotely processed is done in a simple and intuitive way. The results are promising as the speedups accomplished are near optimal, while reducing power consumption, and SPADE allows the easy and efficient deployment of jobs on remote hosts.
{"title":"SPADE: scheduler for parallel and distributed execution from mobile devices","authors":"João Nuno de Oliveira e Silva, L. Veiga, P. Ferreira","doi":"10.1145/1462789.1462794","DOIUrl":"https://doi.org/10.1145/1462789.1462794","url":null,"abstract":"Mobile computing devices, such as mobile phones or even ultra-mobile PC's, are becoming more and more powerful. Because of this fact, users are starting to use these devices to execute tasks that until a few years ago would only be executed on a desktop PC, e.g. picture manipulation, or text editing. Furthermore, these devices, are by now almost continuously connected, either by Wi-Fi or 3G UMTS links. Nevertheless power consumption is still a major factor on these mobile devices usage, restricting autonomy.\u0000 While users should be able to employ mobile computing devices to perform these tasks with convenience, it would improve performance and reduce battery drain if the bulk processing of such tasks could be offloaded to remote hosts accessible by the same user. To accomplish this, we present SPADE, a middleware to deploy remote and parallel execution of some commodity applications to solve complex problems, from mobile devices, without any special programming effort, and by simply defining several data input sets.\u0000 In SPADE, jobs are composed of simpler tasks that will be executed on remote computers. The user states what files should be processed by each task, what application will be launched and defines the application arguments. By using SPADE any user can, for instance, accelerate a batch image manipulation by using otherwise idle remote computers, while releasing the mobile device for other tasks.\u0000 In order to make SPADE usable by a wide set of computer users we implemented two ideas: i) the execution code is a commodity piece of software already installed on the remote computers (e.g. image processing applications), and ii) the definition of the data sets to be remotely processed is done in a simple and intuitive way. The results are promising as the speedups accomplished are near optimal, while reducing power consumption, and SPADE allows the easy and efficient deployment of jobs on remote hosts.","PeriodicalId":364168,"journal":{"name":"workshop on Middleware for Pervasive and Ad-hoc Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126456734","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}
J. V. Filho, M. Endler, Vagner José do Sacramento Rodrigues
In ubiquitous computing systems, the mobility of users and their devices results in recurring disconnections and recon-nections with different networks, and the corresponding dynamic change of the network and domain-specific resources and services accessible from the user's device. On the other hand, some services are available to be used only by users that are located in a well defined region. In this highly dynamic and heterogeneous scenario, applications must be capable of discovering the appropriate instances of the required services in each visited network or region. In order to support such spontaneous interaction, we propose a discovery service based on the notion of a (geographic) location scope. This discovery service is one of the core services of the MoCA architecture, a middleware that supports the development and deployment of location-aware ubiquitous applications.
{"title":"Discovering services with restricted location scope in ubiquitous environments","authors":"J. V. Filho, M. Endler, Vagner José do Sacramento Rodrigues","doi":"10.1145/1376866.1376876","DOIUrl":"https://doi.org/10.1145/1376866.1376876","url":null,"abstract":"In ubiquitous computing systems, the mobility of users and their devices results in recurring disconnections and recon-nections with different networks, and the corresponding dynamic change of the network and domain-specific resources and services accessible from the user's device. On the other hand, some services are available to be used only by users that are located in a well defined region. In this highly dynamic and heterogeneous scenario, applications must be capable of discovering the appropriate instances of the required services in each visited network or region. In order to support such spontaneous interaction, we propose a discovery service based on the notion of a (geographic) location scope. This discovery service is one of the core services of the MoCA architecture, a middleware that supports the development and deployment of location-aware ubiquitous applications.","PeriodicalId":364168,"journal":{"name":"workshop on Middleware for Pervasive and Ad-hoc Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125730366","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}
George T. Edwards, Chiyoung Seo, D. Popescu, S. Malek, N. Medvidović
Software systems that execute in embedded and pervasive environments are frequently required to be self-monitoring, self-adapting, and self-healing. However, supporting these self-* capabilities in pervasive environments creates a number of unique engineering challenges. This paper first describes the challenges that we believe to be the most significant based on our experience developing real-world pervasive software applications with self-* capabilities. We then discuss each challenge in the context of four strategies commonly employed in self-* systems: dynamic software update, service discovery, transparent replication, and logical mobility. Finally, we explain how each strategy is implemented in our architectural middleware platform, Prism-MW.
{"title":"Self-* software architectures and component middleware in pervasive environments","authors":"George T. Edwards, Chiyoung Seo, D. Popescu, S. Malek, N. Medvidović","doi":"10.1145/1376866.1376871","DOIUrl":"https://doi.org/10.1145/1376866.1376871","url":null,"abstract":"Software systems that execute in embedded and pervasive environments are frequently required to be self-monitoring, self-adapting, and self-healing. However, supporting these self-* capabilities in pervasive environments creates a number of unique engineering challenges. This paper first describes the challenges that we believe to be the most significant based on our experience developing real-world pervasive software applications with self-* capabilities. We then discuss each challenge in the context of four strategies commonly employed in self-* systems: dynamic software update, service discovery, transparent replication, and logical mobility. Finally, we explain how each strategy is implemented in our architectural middleware platform, Prism-MW.","PeriodicalId":364168,"journal":{"name":"workshop on Middleware for Pervasive and Ad-hoc Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121102441","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}
This paper is about a novel rule-based approach for reasoning about qualitative spatiotemporal relations among technology-rich autonomous objects, to which we refer to as artifacts. The objective of our work is to provide means for defining spatiotemporal constraints - i.e. logical combinations of spatial relations to artifacts at certain time intervals - at a high level of abstraction, and to recognize relative situations therewith. Such constraints are defined with rules that infer high-level relationships for newly recognized situations, which in turn can be used in other constraints. At any time, the history of known relationships can be queried in order to trigger predefined actions. We decided for qualitative abstractions of both spatial and temporal relationships, as they reflect the semantics of natural language terms and thus facilitate dealing with relationships at the application programming level. The core concepts of this reasoning approach are presented, and the implementation of a middleware for spatiotemporal reasoning as well as evaluation results are discussed.
{"title":"Rule-based reasoning about qualitative spatiotemporal relations","authors":"Clemens Holzmann","doi":"10.1145/1376866.1376875","DOIUrl":"https://doi.org/10.1145/1376866.1376875","url":null,"abstract":"This paper is about a novel rule-based approach for reasoning about qualitative spatiotemporal relations among technology-rich autonomous objects, to which we refer to as artifacts. The objective of our work is to provide means for defining spatiotemporal constraints - i.e. logical combinations of spatial relations to artifacts at certain time intervals - at a high level of abstraction, and to recognize relative situations therewith. Such constraints are defined with rules that infer high-level relationships for newly recognized situations, which in turn can be used in other constraints. At any time, the history of known relationships can be queried in order to trigger predefined actions. We decided for qualitative abstractions of both spatial and temporal relationships, as they reflect the semantics of natural language terms and thus facilitate dealing with relationships at the application programming level. The core concepts of this reasoning approach are presented, and the implementation of a middleware for spatiotemporal reasoning as well as evaluation results are discussed.","PeriodicalId":364168,"journal":{"name":"workshop on Middleware for Pervasive and Ad-hoc Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127078140","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}
With the increased realisation of the benefits of studying environmental data, sensor networks are rapidly scaling in size, heterogeneity of data, and applications. In this paper, we present a State-based Publish/Subscribe (SPS) framework for sensor systems with many distributed and independent application clients. SPS provides a state-based information deduction model that is suited to many classes of sensor network applications. State Maintenance Components (SMCs) are introduced that are simple in operation, flexible in placement, and decomposable for distributed processing. Publish/Subscribe communication forms the core messaging component of the framework. SPS uses the decoupling feature of Pub/Sub and extends this across the SMCs to support a more flexible and dynamic system structure. Our evaluation, using real sensor data, shows that SPS is expressive in capturing conditions, and scalable in performance.
{"title":"SPS: a middleware for multi-user sensor systems","authors":"S. Taherian, J. Bacon","doi":"10.1145/1376866.1376870","DOIUrl":"https://doi.org/10.1145/1376866.1376870","url":null,"abstract":"With the increased realisation of the benefits of studying environmental data, sensor networks are rapidly scaling in size, heterogeneity of data, and applications. In this paper, we present a State-based Publish/Subscribe (SPS) framework for sensor systems with many distributed and independent application clients. SPS provides a state-based information deduction model that is suited to many classes of sensor network applications. State Maintenance Components (SMCs) are introduced that are simple in operation, flexible in placement, and decomposable for distributed processing. Publish/Subscribe communication forms the core messaging component of the framework. SPS uses the decoupling feature of Pub/Sub and extends this across the SMCs to support a more flexible and dynamic system structure. Our evaluation, using real sensor data, shows that SPS is expressive in capturing conditions, and scalable in performance.","PeriodicalId":364168,"journal":{"name":"workshop on Middleware for Pervasive and Ad-hoc Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126102124","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}
In this paper, we outline an approach to the identification of entities for access control that is based on the membership of groups, rather than individuals. By using group membership as a level of indirection between the individual and the system, we can increase privacy and provide incentives for better behaviour. Privacy comes from the use of pseudonyms generated within the group and which can be authenticated as belonging to the group. The incentives for better behaviour come from the continuous nature of groups - members may come and go, but the group lives on, and groups are organised so as to ensure group-longevity, and prevent actions which may harm the group's reputation. We present a novel pseudonym generation mechanism suitable for use in groups without a centralised administration. Finally, we argue that the use of group membership as the basis for formulating policies on interaction is more efficient for disconnected operation, facilitating proxies and the efficient storage of revoked membership and distrusted organisations within bloom filters for small memory footprints.
{"title":"Reconciling privacy and security in pervasive computing: the case for pseudonymous group membership","authors":"I. Wakeman, Dan Chalmers, M. Fry","doi":"10.1145/1376866.1376868","DOIUrl":"https://doi.org/10.1145/1376866.1376868","url":null,"abstract":"In this paper, we outline an approach to the identification of entities for access control that is based on the membership of groups, rather than individuals. By using group membership as a level of indirection between the individual and the system, we can increase privacy and provide incentives for better behaviour. Privacy comes from the use of pseudonyms generated within the group and which can be authenticated as belonging to the group. The incentives for better behaviour come from the continuous nature of groups - members may come and go, but the group lives on, and groups are organised so as to ensure group-longevity, and prevent actions which may harm the group's reputation. We present a novel pseudonym generation mechanism suitable for use in groups without a centralised administration. Finally, we argue that the use of group membership as the basis for formulating policies on interaction is more efficient for disconnected operation, facilitating proxies and the efficient storage of revoked membership and distrusted organisations within bloom filters for small memory footprints.","PeriodicalId":364168,"journal":{"name":"workshop on Middleware for Pervasive and Ad-hoc Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116531796","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}
Due to efficient event dissemination and mobility support, event based middlewares are gaining popularity in pervasive computing environments. However, loss of events caused by broker/client failures or unreliable network connections is a common problem in existing event based middlewares. Middlewares providing support to critical distributed systems must be reliable enough not to lose published events. In this paper, we present the design of REM, a large scale Replication based type and attribute oriented Event Middleware over structured peer to peer (p2p) network. REM safeguards event losses by replicating the states of a broker in the neighboring overlay nodes. REM provides lossless mobility support to the clients even in a highly dynamic environment.
{"title":"A replication oriented approach to event based middleware over structured peer to peer networks","authors":"M. Selim, Y. Goto, Jingde Cheng","doi":"10.1145/1376866.1376877","DOIUrl":"https://doi.org/10.1145/1376866.1376877","url":null,"abstract":"Due to efficient event dissemination and mobility support, event based middlewares are gaining popularity in pervasive computing environments. However, loss of events caused by broker/client failures or unreliable network connections is a common problem in existing event based middlewares. Middlewares providing support to critical distributed systems must be reliable enough not to lose published events. In this paper, we present the design of REM, a large scale Replication based type and attribute oriented Event Middleware over structured peer to peer (p2p) network. REM safeguards event losses by replicating the states of a broker in the neighboring overlay nodes. REM provides lossless mobility support to the clients even in a highly dynamic environment.","PeriodicalId":364168,"journal":{"name":"workshop on Middleware for Pervasive and Ad-hoc Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114945681","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}
Daniel Cheung-Foo-Wo, J. Tigli, S. Lavirotte, M. Riveill
Pervasive devices are becoming popular and smaller. Those mobile systems should be able to adapt to changing requirements and execution environments. But it requires the ability to reconfigure deployed codes, which is considerably simplified if applications are component-oriented rather than monolithic blocks of codes. So, we propose a middleware called WComp which federates an event-driven component-oriented approach to compose distributed services for devices. This approach is coupled with adaptation mechanisms dealing with separation of concerns. In such mechanisms, aspects (called Aspects of Assembly) are selected either by the user or by a self-adaptive process and composed by a weaver with logical merging of high-level specifications. The result of the weaver is then projected in terms of pure elementary modifications of components assemblies with respect to blackbox properties of COTS components. Our approach is validated by analyzing the results of different experiments drawn from sets of application configurations randomly generated and by showing its advantages while evaluating the additional costs on the reaction time to context changing.
{"title":"Self-adaptation of event-driven component-oriented middleware using aspects of assembly","authors":"Daniel Cheung-Foo-Wo, J. Tigli, S. Lavirotte, M. Riveill","doi":"10.1145/1376866.1376872","DOIUrl":"https://doi.org/10.1145/1376866.1376872","url":null,"abstract":"Pervasive devices are becoming popular and smaller. Those mobile systems should be able to adapt to changing requirements and execution environments. But it requires the ability to reconfigure deployed codes, which is considerably simplified if applications are component-oriented rather than monolithic blocks of codes. So, we propose a middleware called WComp which federates an event-driven component-oriented approach to compose distributed services for devices. This approach is coupled with adaptation mechanisms dealing with separation of concerns. In such mechanisms, aspects (called Aspects of Assembly) are selected either by the user or by a self-adaptive process and composed by a weaver with logical merging of high-level specifications. The result of the weaver is then projected in terms of pure elementary modifications of components assemblies with respect to blackbox properties of COTS components. Our approach is validated by analyzing the results of different experiments drawn from sets of application configurations randomly generated and by showing its advantages while evaluating the additional costs on the reaction time to context changing.","PeriodicalId":364168,"journal":{"name":"workshop on Middleware for Pervasive and Ad-hoc Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131894491","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 Service Oriented Architecture (SOA) is used extensively in ubiquitous computing environments. Using external service orchestration, services can be composed into applications. Since cooperation takes place between services that are scattered over the Internet and belong to different parties, there is a growing need to protect the ownership of service providers and keep the security of communication messages in service composition. This paper shows the details of a service-oriented virtual community overlay network designed for secure external service orchestration. It can also provide contracted QoS guarantees that will definitely affect the overall performance of ubiquitous applications. Further, it highlights the working principle of access control policies as well as a service behavior monitoring mechanism using an example scenario.
{"title":"A service-oriented virtual community overlay network for secure external service orchestration","authors":"Shudong Chen, J. Lukkien","doi":"10.1145/1376866.1376869","DOIUrl":"https://doi.org/10.1145/1376866.1376869","url":null,"abstract":"The Service Oriented Architecture (SOA) is used extensively in ubiquitous computing environments. Using external service orchestration, services can be composed into applications. Since cooperation takes place between services that are scattered over the Internet and belong to different parties, there is a growing need to protect the ownership of service providers and keep the security of communication messages in service composition. This paper shows the details of a service-oriented virtual community overlay network designed for secure external service orchestration. It can also provide contracted QoS guarantees that will definitely affect the overall performance of ubiquitous applications. Further, it highlights the working principle of access control policies as well as a service behavior monitoring mechanism using an example scenario.","PeriodicalId":364168,"journal":{"name":"workshop on Middleware for Pervasive and Ad-hoc Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122455678","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}
Inference and reasoning in modern AmI (Ambient Intelligence) middlewares is still a complex task. Currently no common patterns for building smart applications can be identified. This paper presents an ongoing effort to build a generic probabilistic reasoning framework for the networked homes. The framework can be utilized for designing smart agents in a systematic and unified way. The developed modeling and reasoning algorithms make an extensive use of the information about the user and the way he/she interacts with the system. To achieve this, several levels of knowledge representation are combined. Each level enriches the domain knowledge in a way that a consistent, user-adaptable probabilistic knowledge base is constructed. The facts in the knowledge base can be used to encode the logic for a specific application scenario.
{"title":"A probabilistic reasoning framework for smart homes","authors":"Todor Dimitrov, J. Pauli, E. Naroska","doi":"10.1145/1376866.1376867","DOIUrl":"https://doi.org/10.1145/1376866.1376867","url":null,"abstract":"Inference and reasoning in modern AmI (Ambient Intelligence) middlewares is still a complex task. Currently no common patterns for building smart applications can be identified. This paper presents an ongoing effort to build a generic probabilistic reasoning framework for the networked homes. The framework can be utilized for designing smart agents in a systematic and unified way. The developed modeling and reasoning algorithms make an extensive use of the information about the user and the way he/she interacts with the system. To achieve this, several levels of knowledge representation are combined. Each level enriches the domain knowledge in a way that a consistent, user-adaptable probabilistic knowledge base is constructed. The facts in the knowledge base can be used to encode the logic for a specific application scenario.","PeriodicalId":364168,"journal":{"name":"workshop on Middleware for Pervasive and Ad-hoc Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117078035","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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