Jiseong Son

CA5W1HOnto: Ontological Context-Aware Model Based on 5W1H

Ubiquitous computing is necessary to define models for broad contextual information arising out of surrounding environment. It also helps comprehend how to model a mechanism of selectively collecting useful pieces of contextual information and of providing relevant intelligent services. Further, studies are also required on how to process contextual information, its maintenance, and reasoning. However, current context-aware researches are still in need of modeling techniques reflecting ontological characteristics. As a result, it is impossible to effectively provide relevant intelligent services. They are limited as well in terms of contextual reasoning and interoperability across different pieces of contextual information. Aware of the issues, this study proposes an ontology-based context-aware modeling technique, along with a relevant framework, in order to enable efficient specification of contextual information and, thereby, further to provide intelligent context-aware services for context management and reasoning. Moreover, we mobilize the maxim of “five Ws and one H” to process physical and logical contextual information and to support our proposed technique. The maxim-applied modeling technique sets forth an intuitive context-aware schema and demonstrates high applicability to sharing and integration of contextual information. Meanwhile, the ontology-based modeling supports reasoning on contextual information and facilitates more intelligent and reliable services.

Performance Evaluation of Storage-Independent Model for SPARQL-to-SQL Translation Algorithms

This paper describes the performance evaluation of a storage-independent model used for SPARQL-to-SQL translation algorithms. Recently, several web ontology languages have been developed for realizing Semantic Web. In particular, query language and web ontology storages based on RDB have been developed for searching and managing web ontology data. Among the proposed query languages, SPARQL is the most representative. However, SPARQL cannot be used to search data in an RDB. To solve this problem, an SPARQL query must be translated to an SQL query (SQL is the RDB query language). Recently, several translation algorithms have been proposed for SPARQL-to-SQL translation. However, the disadvantage of these algorithms is that they are dependent on the storage structure. We have previously developed a model for storage-independent translation algorithms. In this study, we evaluate the performance of a storage-dependent model and a storage-independent model and discuss the obtained results.

Practical Approach: Independently Using SPARQL-to-SQL Translation Algorithms on Storage

With active research on Web ontology, various storages and ontology query languages have been introduced. The most representative query language for Web ontology is SPARQL which have been developed by W3C, and most storages are based on relational database. Under such a situation, the necessity of SPARQL-to-SQL translation algorithm development becomes issued. Even though several translation algorithms have been proposed, there still remain the following problems: (1) They do not fully support SPARQL statements. It means that they cannot translate SPARQL query statements with UNION or FILTER to SQL; (2) The algorithms are dependent on a specific storage model and it requires much cost for modification and verification. In this paper, we focus on the second issue, and a system model for independent use upon storage structures of an algorithm is proposed. The system model guarantees independency between translation algorithms and storages, and it improves application and usability of a translation algorithm.

View-based Storage-Independent Model for SPARQL-to-SQL Translation Algorithms in Semantic Grid Environment

The metadata in the Semantic Grid are described using the technologies of the Semantic Web, such as OWL (OWL Web Ontology Language), and SPARQL has been recommended by W3C. And most metadata including actual data are stored in relational databases. Under such a situation, the necessity of SPARQL-to-SQL translation algorithm development becomes issued for seamless data access to the Semantic Grid data. Even though several translation algorithms have been proposed, there still remain the following problems, and especially these algorithms are dependent on a specific storage model. Hence, when we try to use one of other storages not the original, much cost is required to modify and verify the translation algorithm. In this paper, we propose a new system model to independently use an algorithm upon storage structures. The system model guarantees independency between translation algorithms and storages, and thus it improves application and usability of translation algorithms.

Dynamic access control model for privacy preserving personalized healthcare in cloud environment

When sharing and storing healthcare data in a cloud environment, access control is a central issue for preserving data privacy as a patients personal health data may be accessed without permission from many stakeholders. Specifically, dynamic authorization for the access of data is required because personal health data is stored in cloud storage via wearable devices. Therefore, we propose a dynamic access control model for preserving the privacy of personal healthcare data in a cloud environment. The proposed model considers context information for dynamic access. According to the proposed model, access control can be dynamically determined by changing the context information; this means that even for a subject with the same role in the cloud, access permission is defined differently depending on the context information and access condition. Furthermore, we experiment the ability of the proposed model to provide correct responses by representing a dynamic access decision with real-life personalized healthcare system scenarios.

An effective access control mechanism in home network environment based on SPKI certificates

In home network environment, security is one of the most important issues that need to be addressed because the services provided by all kinds of household appliances are likely related with the privacy information of the residents. Although several access control mechanisms have been proposed in the last few years, these existing models always preserve all the access control policies in the home gateway or the distributed household appliances, and all of them have conspicuous defects. In this paper, we divide access control policies into general policies and privacy policies according to different security requirements of the residents. With the help of SPKI certificates theory, we demonstrate that our model is an effective access control mechanism by providing two types of access control policies with different security schemes.

Onto: Ontological Context-Aware Model Based on 5W1H

Ubiquitous computing is necessary to define models for broad contextual information arising out of surrounding environment. It also helps comprehend how to model a mechanism of selectively collecting useful pieces of contextual information and of providing relevant intelligent services. Further, studies are also required on how to process contextual information, its maintenance, and reasoning. However, current context-aware researches are still in need of modeling techniques reflecting ontological characteristics. As a result, it is impossible to effectively provide relevant intelligent services. They are limited as well in terms of contextual reasoning and interoperability across different pieces of contextual information. Aware of the issues, this study proposes an ontology-based context-aware modeling technique, along with a relevant framework, in order to enable efficient specification of contextual information and, thereby, further to provide intelligent context-aware services for context management and reasoning. Moreover, we mobilize the maxim of “five Ws and one H” to process physical and logical contextual information and to support our proposed technique. The maxim-applied modeling technique sets forth an intuitive context-aware schema and demonstrates high applicability to sharing and integration of contextual information. Meanwhile, the ontology-based modeling supports reasoning on contextual information and facilitates more intelligent and reliable services.

CBDAC: context-based dynamic access control model using intuitive 5W1H for ubiquitous sensor network

Currently, access control is facing many issues for information protection in the ubiquitous sensor network (USN) environment. In particular, dynamic access control is a central problem where context always changes because of volatile ubiquitous sensors. The use of context is important in USN. In this paper, we focus on the context-driven privacy protection model. In context-based access control research, the access permission technique that uses context is being intensely investigated because of the ease with which various dynamic access permissions can be assigned in accordance with the various changes in context. A key feature of this approach is dynamic access control. Therefore, we propose a model for privacy preservation that is context-based dynamic access control that uses intuitive 5W1H for USN. According to this model, the access control strategy can be determined dynamically based on context elements and subject attributes, in addition to objects and operations, using access control entities; therefore, it is relatively easy to infer the dynamic access control of context expressivity both accurately and efficiently.

Cost Evaluation on the SPARQL-to-SQL Translation System Model

This paper performs cost evaluation of storage-independent SPARQL-to-SQL use model. With development of semantic Web, much research focuses on various technologies about Web ontology. Especially, for management and searching of data in Web ontology, various storages based on RDB and query languages (e.g., SPARQL, RDQL, RQL) have been developed with activity. In this situation, usage of storage based on relational database (RDB) with SPARQL that is the most representative query language has a problem. SPARQL cannot search data in RDB model because RDB model use SQL as query language. Therefore, the development of SPARQL-to-SQL translation algorithm is required. Currently, several translation algorithms have been presented. However, the proposed algorithms have the following problems. The algorithms are dependent on a specific storage model and it requires much cost for modification and verification. We already proposed a system model for independent usage upon storage structures of an algorithm. The goal of this paper is to show explicitly its performance efficiency, and thus this paper first defines cost evaluation models and presents the quantitative evaluation results.

Efficient RFID service framework for seamless semantic interoperability

This paper presents an efficient RFID service framework for supporting semantic consistency. The chief objective of our proposal is to let RFID applications exchange and share information about objects consistently and independently on various application fields. Our proposal enables seamless semantic interoperability and development of high-quality RFID services.