Jooik Jung

IoT Service Selection Based on Physical Service Model and Absolute Dominance Relationship

The Internet of Things (IoT) is a paradigm where real-world entities can be connected to the Internet and provide services with the help of attached devices. With the development of IoT technologies, the number of devices deployed around the world as well as their services are increasing rapidly. Thus, selecting an appropriate service which satisfies a users requirements from such many services becomes a time consuming challenge. Therefore, to address this issue we propose a Physical Service Model (PSM) to describe heterogeneous IoT physical services. PSM contains three core concepts (Device, Resource and Service) and specifies their relationships. Based on PSM, we define four quality of service (QoS) attributes and rate candidate services according to user requirements. In order to dynamically aggregate individual QoS ratings and select physical services, we propose a Physical Service Selection (PSS) method which takes a user preference and an absolute dominance relationship among physical services into account. Finally, experiments are conducted to evaluate the performance of the proposed method.

A Pub/Sub-Based Fog Computing Architecture for Internet-of-Vehicles

Fog computing is a promising paradigm in terms of extending cloud computing to an edge network. In a broad sense, fog computing in Internet-of-Vehicles(IoV) provides low-latency services since fog nodes are closely located with moving cars and are locally distributed. In this paper, we propose a fog computing architecture based on a publish/subscribe model. After that, we describe a traffic congestion control scenario using a smart traffic light system which operates on top of the proposed architecture. Furthermore, we propose an upper-level domain ontology in order to enhance the expressivity of knowledge and describe a variety of semantic properties which interlink spatial information in IoV. Finally, we present an active rule where supports the exchange of event-driven messages between publishing and subscribing fog nodes.

Short paper: Semantic URI-based event-driven physical mashup

To enhance the integration of different IoT application domains, we propose a two-layered IoT information model that consists of domain-independent and domain-specific models. In addition, for the meaningful composition of things and their services, a semantic URI as a unique identifier is allocated to a thing. Finally, a modeling approach of constructing physical mashups is proposed for the event-driven composition of IoT services. In order to show the efficiency of the proposed event-driven physical mashup approach, an energy management scenario in u-campus is demonstrated as a case study.

Semantic search for smart mobile devices

To enhance the incorrectness of keyword based search, we propose an efficient semantic search method based on a lightweight mobile ontology designed for smart mobile devices. In addition, we implement a prototype of semantic search engine working on Android smartphones and our prototype engine provides better user experience compared with keyword based search.

A fast and scalable approach for IoT service selection based on a physical service model

Information Systems (ISs) have become one of the crucial tools for various organizations in managing and coordinating business processes. Now we are entering the era of the Internet of Things (IoT). IoT is a paradigm in which real-world physical things can be connected to the Internet and provide services through the computing devices attached. The IoT infrastructure is starting to be integrated with ISs thereby diminishing the boundaries between the physical world and the business IT systems. With the development of IoT technologies, the number of connected things and their available physical services are increasing rapidly. Thus, selecting an appropriate service that satisfies a user’s requirements from such services becomes a time-consuming challenge. To address this issue, we propose a Physical Service Model (PSM) as a common conceptual model to describe heterogeneous IoT physical services. PSM contains three core concepts (device, resource, and service) and specifies their relationships. Based on the proposed PSM, we define three types of Quality of Service (QoS) attributes and rate candidate services according to user requirements. To dynamically rate QoS values and select an appropriate physical service, we propose a Physical Service Selection (PSS) method that takes a user preference and an absolute dominance relationship among physical services into account. Finally, experiments are conducted to evaluate the performance of the proposed method.

Hypergraph-based overlay network model for the Internet of Things

As the Internet of Things (IoT) is gaining tremendous popularity from industries to researchers for its potential to provide business opportunities and academic contributions, several research challenges have risen to the surface. With billions of IoT objects being produced, connected and interacting, one of the challenges claim that there is an imperative need for ways to organize and manage the objects effectively. This paper, therefore, proposes a network-based multidimensional structure to model the IoT for efficient management and discovery of IoT objects. In addition, we address various research issues that must be considered in designing the proposed model. To test the feasibility of the model, we present numerous experiments performed on our smart home automation demo box, along with their justifications.

Keyword Based Semantic Search for Mobile Data

Most of the mobile platforms provide a keyword based full text search (FTS) for users to find what they want. However, FTS has difficulties in dealing with the cases where a user cannot remember the exact keywords about target data or the number of search results is too many. To overcome these limitations of FTS, we propose a semantically enhanced method of searching for data on mobile devices along with mobile ontology. Experimental results of the proposed method show that our method provides accurate search results and is suitable for a mobile environment.

An efficient access control based on role attributes in service oriented environments

There are difficulties in applying role-based dynamic delegation to Web services. This is because XACML, which is a standard language for describing the access policies of Web services, does not support the dynamic delegation between roles in different domains. We propose role attributes to specify the characteristics of roles in different domains to support role-based dynamic delegation in a Web services system, which services in different administrative domains work together. The proposed method enables the dynamic delegation in a service-oriented system based on the proposed role attributes. Experimental results show that the proposed method performs better than previous methods, resulting in enhancing an authorization rate about 32 percent on average.

Outlier-robust web service selection based on a probabilistic QoS model

In real world, a service may be affected by various factors making service selection process a difficult task. Therefore it is important to select an appropriate service efficiently from a large number of services based on the quality of a service QoS. However, existing approaches have limitations in processing QoS data with outliers that may occur in reality. When decomposing a global QoS constraint given by a service requester into local constraints, local thresholds are commonly computed with no consideration of outliers. Therefore, an appropriate service may not be selected due to false negative errors. To address this limitation, we propose an outlier-robust Web service selection approach based on a probabilistic QoS model. Specifically, the approach prunes services which do not satisfy a global constraint due to outliers. A service is then selected based on its probability of satisfying a global constraint. Experimental results show that the proposed approach outperforms an existing solution in terms of global QoS conformance.

Context-Aware Mashup for Smart Mobile Devices

A mobile mash up should be able to compose the component services in accordance with a users context. We propose a context-aware mash up method for smart mobile devices. For this purpose, a novel user request model is presented and the conventional service description model is extended. We propose a context ontology which can efficiently manage contextual information in a mobile environment. Furthermore, the proposed method undergoes three computations -- functional, I/O connectable and contextual matching. In particular, the contextual matching technique utilizes two types of contextual information that are proposed in this paper, implicit and explicit contexts. In order to evaluate the accuracy of the proposed method, a test registry based on real world Web APIs was built. Experimental results show an overall improvement of 26.7% in precision compared with the case where contextual information was not utilized.