Yongyun Cho

Context-aware workflow language based on web services for ubiquitous computing

The services for a ubiquitous computing environment have to automatically provide users with adaptive services according to dynamically changing context information, which is obtained from both the users and their environment. Workflows used in business processes and distributed computing environments have supported service automation by connecting many tasks with rules and/or orderings. To adapt these workflows to ubiquitous computing, we must specify the context information on their transition conditions. In this paper, we propose uWDL, Ubiquitous Workflow Description Language, to specify the context information on the transition constraints of a workflow in order to support adaptive services. And it is designed based on Web services, which are standardized and independent of heterogeneous and various platforms, protocols, and languages. In order to verify the effectiveness of uWDL, we designed and implemented a scenario described with uWDL. And we demonstrated that the uWDL system provides users with autonomic services in ubiquitous computing environments.

A ubiquitous workflow service framework

In ubiquitous environments, all services head for context-awareness to provide appropriate services for a users situation. However, it is hard to implement all kinds of things related to context managements. In this paper we propose a ubiquitous workflow service framework, named uFlow, based on a structural context model and uWDL, which is a ubiquitous workflow description language. Service developers can easily describe context-aware services using the uFlow framework so long as they only select available services based on Web Services and describe context information as a transition condition of workflow services. In order to verify the effectiveness of the uFlow framework, we designed and implemented a service scenario described with uWDL, and demonstrated that the scenario provides users with appropriate services according to a users situation in ubiquitous computing environments.

AWorkflow Language for Context-Aware Services

In the traditional computing environments such as business processes and distributed computing, workflows have well been adopted for service automation. These days, there are many studies that have tried to adopt workflows to ubiquitous computing. Such the workflow systems as uFlow and FollowMe use workflows to support context-aware services in ubiquitous computing environments. However the existing workflow systems have not yet offered a workflow language enough to support workflows various functions. In this paper, we propose a new workflow language for context-aware workflow services in ubiquitous computing environments. The suggested language can specify context information on the transition constraints of a workflow, and support various workflow functions and adaptive services. In order to verify the efficiency of the suggested language, we designed a workflow scenario for context-aware services with the language, and demonstrated a process that provides users with autonomic services according to the scenario using the uFlow system.

A Context-Aware Workflow System for a Smart Home

A workflow model has been successively applied to traditional computing environments such as business processes for service automation. Recently, there are many studies that have tried to adopt workflows to ubiquitous computing. A service in the ubiquitous computing environments must be executed according to a users situation information. However existing workflow systems have not yet included functions enough to support context-aware services for ubiquitous computing. In this paper, we propose a new context- aware workflow language and system for ubiquitous computing environments. The suggested language can specify context information on the transition constraints of a workflow, and support various workflow functions and adaptive services. And the proposed system can offer context-aware services according to users service demand or situation information. We verify the efficiency of the suggested system, through comparison experiments with existing workflow systems such as FollowMe and uFlow.

A workflow language based on structural context model for ubiquitous computing

Workflows used in business processes and distributed computing environments have supported service automation by connecting many tasks with rules and/or orderings. To adapt these workflows to ubiquitous computing, we must specify the context information on their transition conditions. In this paper, we propose uWDL, Ubiquitous Workflow Description Language, to specify context information on the transition constraints of a workflow in order to support adaptive services, and we designed a structural context model to express the context information in uWDL. Furthermore, uWDL is designed based on Web services, which are standardized and independent of various heterogeneous platforms, protocols, and languages. In order to verify the effectiveness of uWDL, we designed and implemented a scenario described with uWDL, and demonstrated that the uWDL system provides users with autonomic services in ubiquitous computing environments.

A uWDL handler for context-aware workflow services in ubiquitous computing environments

To develop context-aware workflow services in ubiquitous computing environments, a service developer must describe and recognize context information as transition constraints. uWDL (ubiquitous Workflow Description Language) [1] is a workflow language that describes the situation information of ubiquitous environments as a rule-based service transition condition. In this paper, we suggest a uWDL handler that supports workflow’s service transition to be aware of user’s condition information. The uWDL handler consists of a uWDL parser and a uWDL context mapper. The uWDL parser represents contexts described in the scenario with sub-trees of a DIAST (Document Instance Abstract Syntax Tree) as a result of the parsing. To derive the right transition of workflow services, the uWDL context mapper compares contexts described in sub-trees of DIAST with a user’s situation information generated from ubiquitous environments by using a context comparison algorithm. Therefore, the uWDL handler will be used in developing context-aware workflow applications that can change the flow of a service scenario according to the user’s situation information in the ubiquitous computing environment.

An Embedded Software Testing Tool Supporting Multi-paradigm Views

Because embedded software is necessarily required to control and operate devices in ubiquitous environments, developers can use a development tool in order to make their embedded software efficient. In this paper, we propose an embedded software testing tool, which supports graphical debugging views of multi paradigms. The tool can improve the efficiency of embedded software through performance testing. The tool provides not only various profiling but also a source-level testing and a unit testing with the graphical views. The tool includes a test suite generator to easily make a test driver, and a report generator to raise reusability of test results by representing string-type results to XML classes. With the tool, developers not only can intuitively analyze functions of embedded software, but also easily improve performance of the software. The tool will be useful for developing and testing embedded software in ubiquitous computing environments.

A context-adaptive workflow language for ubiquitous computing environments

Recently, the workflow systems such as uFlow and FollowMe adopt workflow models to support context-aware services in ubiquitous computing environments. A service in the ubiquitous computing environments must be executed according to a users situation information, which is generated dynamically from sensors. However, the existing workflow systems use such workflow languages as uWDL, BPEL and XLANG, which are not yet enough to support context-aware services in ubiquitous computing environments. In this paper, we propose a new workflow language and a workflow system for context-aware workflow services in ubiquitous computing environments. With the suggested workflow language and the workflow system, a user can describe contexts into workflow as service transition conditions and can apply changes of users service demand or situation information into an on-going workflow without interrupting or deleting workflow service. In order to verify the efficiency of the suggested language and system, we design a workflow scenario for context-aware services with the language and simulate a process that the proposed system changes dynamically contexts described in a workflow against changes of users situation information.

A context-aware smart home service system based on uWDL

For a smart home in ubiquitous computing environments, execution of all the home services must be dependent on user’s situation contexts, which are dynamically generated in ubiquitous environments. In this paper, we propose a home-network service system that can support home services appropriate to user’s situation information in ubiquitous computing environments. The suggested system uses a uWDL workflow service scenario [2] describing user’s situation information as service execution constraints and supports a context-aware home service through comparing contexts described in the service scenario with user’s situation information generated from ubiquitous computing environments. To do that, the suggested system represents contexts described in a uWDL document as a context subtree, which expresses not only context data but also relation information among services into the fields of its node. The suggested system uses a algorithm for context comparison between context subtrees and user’s situation information. The algorithm selects a context that has all together values and types entirely equal to those of user’s contexts. Therefore, the suggested system will be useful in the development of a context-aware home-network workflow service application based on uWDL in the ubiquitous computing environment.

CAWET: A Tool of Context-Aware Workflow with Hand-Held Devices

Hand-held devices are rapidly becoming a common technology at work, school, and play. The technologies related with hand-held devices have widely applied to the areas of ubiquitous computing or embedded computing. In recent years, context-aware computing is rapidly developing and can bring important benefits such as interaction with computation by explicit acts of communication and implicit context. In this paper, we present CAWET (Context-Aware Workflow Editor Tool), a context-aware, adaptive and personalized development tool that can edit userpsilas current context information in ubiquitous computing environment through hand-held devices. In order to enhance the support offered by hand-held devices to users, enhanced convenience, more services and functionalities will be added into an initial workflow scenario without interfering workflow services. CAWET architecture provides context-aware information by using uWDL document as the context, which is not only used to express context data but also relation information among services into the fields of its nodes. The suggested CAWET uses an algorithm for context comparison between context sub-tree and userpsilas situation information. The algorithm selects a context that has values and types entirely equal to those of the userpsilas contexts.