Eunhoe Kim

An ontology-based context model in a smart home

This paper introduces an ontology-based context model in ubiquitous computing environment. We describe a Getting up scenario to show whether the model is valuable for description of context information in a home domain. We modeled context metadata as well as context information. Context metadata are defined for the use of additional context information such as probabilistic or fuzzy logic reasoning, rich understanding, or efficient context information collection. In addition we developed a context ontology server that manages and processes context information and metadata, and it is based on the ontology-based context model which is introduced in this paper. We used OWL (Web Ontology Language) for modeling the context, and extended the OWL language to represent context metadata.

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.

A Context Management System for Supporting Context-Aware Applications

This paper presents a context management system for supporting context-aware applications in a smart home. In a ubiquitous computing environment context changes dynamically and the applications have to adapt their behaviors according to the context. Therefore a context-aware system in a ubiquitous computing environment has to manage their context information effectively and satisfy qualities of context information required by context-aware applications. To solve these design issues we suggest a context-management system based on context metadata ontology. We defined context metadata ontology as the additional characteristics of context information to improve certainty, freshness, and understanding of the context information. Using the context metadata ontology, we have achieved effective context management. Our system also provides semantic-level interoperability between system components, because it is based on the ontology and service-oriented architecture. In this paper we explain context metadata ontology briefly, and we design and implement the context management system.

A context-awareness middleware based on service-oriented architecture

This paper presents a middleware based on SOA (Service-Oriented Architecture) for context-awareness in a home network with ubiquitous computing. The context-awareness middleware addresses design issues such as heterogeneity, dynamicity, and extensibility issues of ubiquitous computing environment. We also suggest a context model supporting semantic level interoperability of context. In this paper, first we model context metadata ontology as well as context information ontology for the context-awareness middleware. Then we explain a service-oriented context-awareness middleware based on the context model which is introduced in this paper.

RSP: A Remote OSGi Service Sharing Scheme

In this paper, we present RSP (Remote Service Provider), which is a P2P-based effective service sharing scheme on distributed OSGi frameworks. RSP doesn’t need to install additional software or have an additional transformation process of the service representation, because it uses only OSGi technology. In addition, RSP doesn’t have any bottleneck problems, and it improves scalability by providing a service discovery mechanism using P2P. RSP can also access remote services transparently and it can guarantee reliability by sending an immediate notice about changes in the remote services.

A method for detecting illegally copied APK files on the network

We present a method of detecting illegally copied Android apps targeting at the APK files. We extracted the data objects being transmitted from the network through the process of sniffing, analyzing, and assembling packets. Then, we made an analysis on the features of APK files to judge whether the extracted data object is an APK file or not. We were able to achieve a success rate of 95.5% in detecting illegally copied apps by identifying them through APK feature points and forensic technologies.

A semantic interoperable context infrastructure using web services

Ubiquitous computing is more complex and dynamic than distributed computing and mobile computing because of its pervasiveness. This paper presents a context infrastructure to provide the semantic interoperability of context in a ubiquitous computing environment. In addition, we explore the web services approach to support interaction interoperability between the components of the context infrastructure on heterogeneous platforms. First, we develop context ontology- Entity, contextType, and Value - for providing semantic interoperability of context. Then, we suggest a context infrastructure using the web services for interaction interoperability. We also explain context reasoning and evaluate the performance of the context infrastructure.

An Extended SNMP Scheme for a Digital Convergence Device with Control Functions

SNMP (Simple Network Management Protocol) is a standard protocol for management of network devices, and it provides excellent features such as scalability, information management, authentication, encryption, and access control. However, SNMP has a structural weakness to fully support control functions for integrated management of digital convergence devices, and it has a limitation of message length in SNMP communication. In this paper, we present an extended SNMP scheme for integrated management of digital convergence devices with control functions. We modified the SNMP architecture by adding DDS (Device Driver Subsystem) to SNMP engine for controlling different devices and by defining CADM (Control Agent Driver Model), therefore we solved the ambiguity problem between `set` and `control` of SNMP. And the extended SNMP made it easy for SNMP applications to use various control functions. The extended SNMP can transport massive high-level information by adding three new SNMP commands which eliminate the limit of message length.

An Effective Service Sharing Scheme on Distributed OSGi Frameworks

ABSTRACT OSGi technology has applied to Home Network, but now it is loaded into even heterogeneous devices in various domains. Therefore, it is necessary to cooperate with each other framework for offering effective services in distributed OSGi frameworks. However until now, OSGi specification doesn’t provide any methodthat can share the services registered on remote OSGi frameworks. In order to solve this problem, there have been several researches that used existing distributed middleware technologies such as JXTA and Web Services. However these technologies have some weakness, that is, they consume lots of computing resources and need additional process to transform the services. A middleware called R-OSGi uses only OSGi technology for sharing remote OSGi services, but R-OSGi may have a communication bottleneck and SPOF (Single Point of Failure) problem, because it has a central service registry. In this paper we present RSP (Remote Service Provider), which is a P2P-based effective service sharing scheme on distributed OSGi framework. RSP doesn’t need to install additional software nor have the additional transformation process of the service representation, because it uses only OSGi technology. In addition it doesn’t have any bottleneck problem and improves scalability by providing the service discovery mechanism using P2P. RSP can also access remote services transparently and it can guarantee reliability by sending an immediate notice about changes of the remote services. Keywords:OSGi, Service Sharing, Service Discovery, P2P

Design and implementation of the context handlers in a ubiquitous computing environment

This paper is concerned with the design and implementation of the context handlers for context-awareness in a ubiquitous computing environment. The context handlers address design issues of context handling: abstraction of context values, semantic interoperability of context information, logical and semantic interpretation of context information, and structuralization of context information for specifying various situations. To address these design issues, we define a structural context model, a context schema based on ontology, and user-friendly context value ontology. We also use ontology reasoning and rule-based reasoning. This paper focuses on context handling methods in a context-aware system. We expect that these context handling methods will help context-aware system developers to design and implement context handlers in a ubiquitous computing environment.