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Article

Lenin Mehedy, Sungyoung Lee, Salahuddin Muhammad Salim Zabir and Young‐Koo Lee

Presence of innumerable sensors, complex deduction of contexts from sensor data, and reusability of contextual information impose the requirement of middleware for context

Abstract

Purpose

Presence of innumerable sensors, complex deduction of contexts from sensor data, and reusability of contextual information impose the requirement of middleware for context aware computing. Smart applications, hosted in myriad devices (e.g. PDA, mobile, PCs), acquire different contexts from the middleware and act intelligently based on the available contexts in a context‐aware computing environment. As the system grows larger, scalable delivery of contexts from the middleware to numerous context‐aware applications will be inevitable. However, pure unicast based or pure broadcast‐based dissemination cannot provide high scalability as well as low‐average latency. The purpose of this paper is to present a scalable context delivery mechanism for the middlewares to facilitate the development of larger context‐aware computing systems.

Design/methodology/approach

The proposed scheme is based on hybrid data dissemination technique where the most frequently requested data (e.g. HOT contexts) are delivered through multicast and the rest (e.g. COLD contexts) are delivered through unicast to reduce network traffic. The paper dynamically prioritizes and classifies the HOT and COLD context data depending on the number of requests and longest waiting time. Moreover, the division of bandwidth between the delivery of HOT and COLD contexts reduces average latency. Polling traffic is decreased by incorporating leasing mechanism. Extensive simulation is conducted to evaluate the proposed scheme.

Findings

The mechanism dynamically prioritizes and classifies the hot and cold context data depending on the request rate and longest waiting time. The solution addresses the push popularity problem that occurs in the passive as the passive clients access data without sending explicit requests. The leasing mechanism is incorporated to reduce the periodical requests (polling) for better performance.

Originality/value

The paper is of value in presenting a scalable context delivery mechanism for the middlewares to facilitate the development of larger context‐aware computing systems and also in presenting implementation details of a prototype that is developed using Jini framework and Java reliable multicast service (JRMS) library.

Details

International Journal of Pervasive Computing and Communications, vol. 4 no. 2
Type: Research Article
ISSN: 1742-7371

Keywords

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Article

Jian Zhu, Mohammad Oliya, Hung Keng Pung and Wai Choong Wong

The rapid advances in the technologies of mobile computing and wireless communications have facilitated the use of applications and services on handheld devices. Sharing…

Abstract

Purpose

The rapid advances in the technologies of mobile computing and wireless communications have facilitated the use of applications and services on handheld devices. Sharing of living experience (SOLE) is one such service, through which users can share their experience of daily activities such as shopping, entertainment, and traveling. This paper seeks to study SOLE in more detail.

Design/methodology/approach

The paper presents an application framework for a context‐aware SOLE which considers location, preferences, and other useful information for a seamless user experience. SOLE leverages on the service‐oriented middleware, Coalition. Entities of interest are represented as services registered with Coalition, which are organized using location information. This facilitates location‐based selection of entities for associating or retrieving experiences. In addition, Coalition incorporates the contexts of users in the discovery and delivery of experience information. Besides, to cater for resource constraints of mobile devices, the concept of “proxy” is introduced.

Findings

A detailed study of SOLE, namely, its design as well as its interaction with the middleware, information providers and information consumers, is provided. As a proof of concept, a prototype of SOLE for mobile phone users is also provided. The experiments show the ease of using SOLE and its acceptable performance in practice.

Originality/value

SOLE is generic and scalable, by not assuming a specific application scenario; flexible, by allowing the user to choose where to store the experience data and to specify his audience; and context‐aware by considering the contexts of the user such as location and preferences in the experience sharing process.

Details

International Journal of Pervasive Computing and Communications, vol. 7 no. 1
Type: Research Article
ISSN: 1742-7371

Keywords

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Article

Xiufeng Cheng, Jinqing Yang and Lixin Xia

This paper aims to propose an extensible, service-oriented framework for context-aware data acquisition, description, interpretation and reasoning, which facilitates the…

Abstract

Purpose

This paper aims to propose an extensible, service-oriented framework for context-aware data acquisition, description, interpretation and reasoning, which facilitates the development of mobile applications that provide a context-awareness service.

Design/methodology/approach

First, the authors propose the context data reasoning framework (CDRFM) for generating service-oriented contextual information. Then they used this framework to composite mobile sensor data into low-level contextual information. Finally, the authors exploited some high-level contextual information that can be inferred from the formatted low-level contextual information using particular inference rules.

Findings

The authors take “user behavior patterns” as an exemplary context information generation schema in their experimental study. The results reveal that the optimization of service can be guided by the implicit, high-level context information inside user behavior logs. They also prove the validity of the authors’ framework.

Research limitations/implications

Further research will add more variety of sensor data. Furthermore, to validate the effectiveness of our framework, more reasoning rules need to be performed. Therefore, the authors may implement more algorithms in the framework to acquire more comprehensive context information.

Practical implications

CDRFM expands the context-awareness framework of previous research and unifies the procedures of acquiring, describing, modeling, reasoning and discovering implicit context information for mobile service providers.

Social implications

Support the service-oriented context-awareness function in application design and related development in commercial mobile software industry.

Originality/value

Extant researches on context awareness rarely considered the generation contextual information for service providers. The CDRFM can be used to generate valuable contextual information by implementing more reasoning rules.

Details

The Electronic Library, vol. 36 no. 6
Type: Research Article
ISSN: 0264-0473

Keywords

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Article

Mehdia Ajana El Khaddar, Mhammed Chraibi, Hamid Harroud, Mohammed Boulmalf, Mohammed Elkoutbi and Abdelilah Maach

This paper aims to demonstrate that a policy-based middleware solution which facilitates the development of context-aware applications and the integration of the…

Abstract

Purpose

This paper aims to demonstrate that a policy-based middleware solution which facilitates the development of context-aware applications and the integration of the heterogeneous devices should be provided for ubiquitous computing environments. Ubiquitous computing targets the provision of seamless services and applications by providing an environment that involves a variety of devices having different capabilities. These applications help transforming the physical spaces into computationally active and smart environments. The design of applications in these environments needs to consider the heterogeneous devices, applications preferences and rapidly changing contexts. The applications, therefore, need to be context-aware so that they can adapt to different situations in real-time.

Design/methodology/approach

In this paper, we argue that a policy-based middleware solution that facilitates the development of context-aware applications and the integration of the heterogeneous devices should be provided for ubiquitous computing environments. The middleware allows applications to track items and acquire contextual information about them easily, reason about this information captured using different logics and then adapt to changing contexts. A key issue in these environments is to allow heterogeneous applications to express their business rules once, and get the preferred data once they are captured by the middleware without any intervention from the application side.

Findings

Our middleware tackles this problem by using policies to define the different applications’ rules and preferences. These policies can specify rules about the middleware services to be used, type of data captured, devices used, user roles, context information and any other type of conditions.

Originality/value

In this paper, we propose the design of a flexible and performant ubiquitous computing, and context-aware middleware called FlexRFID along with its evaluation results.

Details

International Journal of Pervasive Computing and Communications, vol. 11 no. 1
Type: Research Article
ISSN: 1742-7371

Keywords

Abstract

Details

Research-practice Partnerships for School Improvement: The Learning Schools Model
Type: Book
ISBN: 978-1-78973-571-0

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Article

Tarak Chaari, Frédérique Laforest and Augusto Celentano

The simple environment for context aware systems (SECAS) Project deals with the adaptation of applications to the context (user preferences and environment, terminal…

Abstract

Purpose

The simple environment for context aware systems (SECAS) Project deals with the adaptation of applications to the context (user preferences and environment, terminal, etc.). The authors aim to develop a platform which makes the services, data and the user interface of applications adaptable to different context situations.

Design/methodology/approach

Previous research has concentrated on how to capture context data and how to carry it to the application. The present work focuses on the impact of context on the application core. A case study in the medical field is also analysed.

Findings

The paper illustrates a new definition of the context which separates the application data from the parameters of the context. This definition helps to establish a complete study on how to adapt applications on their three dimensions (services, content and presentation) to the context.

Originality/value

The paper presents the SECAS platform, one that ensures the deployment of adaptive context‐aware applications.

Details

International Journal of Pervasive Computing and Communications, vol. 3 no. 4
Type: Research Article
ISSN: 1742-7371

Keywords

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Article

Penghe Chen, Shubhabrata Sen, Hung Keng Pung, Wenwei Xue and Wai Choong Wong

The rapid proliferation of mobile context aware applications has resulted in an increased research interest towards developing specialized context data management…

Abstract

Purpose

The rapid proliferation of mobile context aware applications has resulted in an increased research interest towards developing specialized context data management strategies for mobile entities. The purpose of this paper is to aim to develop a new way to model mobile entities and manage their contexts accordingly.

Design/methodology/approach

This paper proposes the concept of “Mobile Space” to model mobile entities and presents strategies to manage the various contexts associated therein. To handle availability related issues, two system services are designed: the “Availability Updating Service” which is an identifier based mechanism and is designed to keep track of mobile objects and handle availability related issues, and the “Application Callback Service” which is a publish/subscribe based mechanism to handle application disruptions and interruptions arising due to mobility.

Findings

The paper presents a detailed study of the proposed framework and a description of the underlying services and the components therein to validate the framework. Experimental results carried out in WiFi and 3G environments indicate that the proposed techniques can support mobile applications and minimize application disruptions with minimal overhead.

Originality/value

The proposed context management framework is generic in nature and is not designed for a specific class of applications. Any mobile context aware application can leverage on the framework and utilize the provided functionalities to manage application disruptions. Also, the decoupling of mobile application layer and the underlying context data management layer renders context data management layer transparent to the application design.

Details

International Journal of Pervasive Computing and Communications, vol. 8 no. 2
Type: Research Article
ISSN: 1742-7371

Keywords

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Article

Engida H. Gebre and Esteban Morales

This paper aims to examine the nature and sufficiency of descriptive information included in open datasets and the nature of comments and questions users write in relation…

Abstract

Purpose

This paper aims to examine the nature and sufficiency of descriptive information included in open datasets and the nature of comments and questions users write in relation to specific datasets. Open datasets are provided to facilitate civic engagement and government transparency. However, making the data available does not guarantee usage. This paper examined the nature of context-related information provided together with the datasets and identified the challenges users encounter while using the resources.

Design/methodology/approach

The authors extracted descriptive text provided together with (often at the top of) datasets (N = 216) and the nature of questions and comments users post in relation to the dataset. They then segmented text descriptions and user comments into “idea units” and applied open-coding with constant comparison method. This allowed them to come up with thematic issues that descriptions focus on and the challenges users encounter.

Findings

Results of the analysis revealed that context-related descriptions are limited and normative. Users are expected to figure out how to use the data. Analysis of user comments/questions revealed four areas of challenge they encounter: organization and accessibility of the data, clarity and completeness, usefulness and accuracy and language (spelling and grammar). Data providers can do more to address these issues.

Research limitations/implications

The purpose of the study is to understand the nature of open data provision and suggest ways of making open data more accessible to “non expert users”. As such, it is not focused on generalizing about open data provision in various countries as such provision may be different based on jurisdiction.

Practical implications

The study provides insight about ways of organizing open dataset that the resource can be accessible by the general public. It also provides suggestions about how open data providers could consider users' perspectives including providing continuous support.

Originality/value

Research on open data often focuses on technological, policy and political perspectives. Arguably, this is the first study on analysis of context-related information in open-datasets. Datasets do not “speak for themselves” because they require context for analysis and interpretation. Understanding the nature of context-related information in open dataset is original idea.

Details

Information and Learning Sciences, vol. 121 no. 1/2
Type: Research Article
ISSN: 2398-5348

Keywords

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Article

Khanh Tran Dang, Nhan Trong Phan and Nam Chan Ngo

The paper aims to resolve three major issues in location-based applications (LBA) known as heterogeneity, user privacy, and context-awareness by proposing an elastic and

Abstract

Purpose

The paper aims to resolve three major issues in location-based applications (LBA) known as heterogeneity, user privacy, and context-awareness by proposing an elastic and open design platform named OpenLS privacy-aware middleware (OPM) for LBA.

Design/methodology/approach

The paper analyzes relevant approaches ranging from both academia and mobile industry community and insists the importance of heterogeneity, user privacy, and context-awareness towards the development of LBA.

Findings

The paper proposes the OPM by design. As a result, the OPM consists of two main component named application middleware and location middleware, which are cooperatively functioned to achieve the above goals. In addition, the paper has given the implementation of the OPM as well as its experiments. It is noted that two privacy-preserving techniques at two different levels are integrated into the OPM, including Memorizing algorithm at the application level and Bob-tree at the database level. Last but not least, the paper shows further discussion about other problems and improvements that might be needed for the OPM.

Research limitations/implications

Each issue has its sub problems that cause more influences to the OPM. Besides, each of the issues requires more investigations in depth in order to have better solutions in detail. Therefore, more overall experiments should be conducted to assure the OPM's scalability and effectiveness.

Practical implications

The paper hopefully promotes and speeds up the development of LBA when providing the OPM with suitable application programming interfaces and conforming the OpenLS standard.

Originality/value

This paper shows its originality towards location-based service (LBS) providers to develop their applications and proposes the OPM as a unified solution dealing with heterogeneity, user privacy, and context-awareness in the world of LBS.

Details

International Journal of Pervasive Computing and Communications, vol. 9 no. 4
Type: Research Article
ISSN: 1742-7371

Keywords

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Article

Kostas Stefanidis, Evaggelia Pitoura and Panos Vassiliadis

A context‐aware system is a system that uses context to provide relevant information or services to its users. While there has been a variety of context middleware…

Abstract

Purpose

A context‐aware system is a system that uses context to provide relevant information or services to its users. While there has been a variety of context middleware infrastructures and context‐aware applications, little work has been done on integrating context into database management systems. The purpose of this paper is to consider a preference database system that supports context‐aware queries, that is, queries whose results depend on the context at the time of their submission.

Design/methodology/approach

The paper proposes using data cubes to store the dependencies between context‐dependent preferences and database relations and on‐line analytical processing techniques for processing context‐aware queries. This allows for the manipulation of the captured context data at various levels of abstraction, for instance, in the case of a context parameter representing location, preferences can be expressed, for example, at the level of a city, the level of a country or both. To improve query performance, the paper uses an auxiliary data structure, called context tree. The context tree stores results of past context‐aware queries indexed by the context of their execution. Finally, the paper outline the implementation of a prototype context‐aware restaurant recommender.

Findings

The use of context is important in many applications such as pervasive computing where it is important that users receive only relevant information.

Originality/value

Although there is much research on location‐aware query processing in the area of spatial‐temporal databases, integrating other forms of context in query processing is a rather new research topic.

Details

International Journal of Pervasive Computing and Communications, vol. 3 no. 4
Type: Research Article
ISSN: 1742-7371

Keywords

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