Context-aware middleware for pervasive elderly homecare

The growing aging population faces a number of challenges, including rising medical cost, inadequate number of medical doctors and healthcare professionals, as well as higher incidence of misdiagnosis. There is an increasing demand for a better healthcare support for the elderly and one promising solution is the development of a context-aware middleware infrastructure for pervasive health/wellness-care. This allows the accurate and timely delivery of health/medical information among the patients, doctors and healthcare workers through a widespread deployment of wireless sensor networks and mobile devices. In this paper, we present our design and implementation of such a Context-Aware Middleware for Pervasive Homecare (CAMPH). The middleware offers several key-enabling system services that consist of P2P-based context query processing, context reasoning for activity recognition and context-aware service management. It can be used to support the development and deployment of various homecare services for the elderly such as patient monitoring, location-based emergency response, anomalous daily activity detection, pervasive access to medical data and social networking. We have developed a prototype of the middleware and demonstrated the concept of providing a continuing-care to an elderly with the collaborative interactions spanning multiple physical spaces: person, home, office and clinic. The results of the prototype show that our middleware approach achieves good efficiency of context query processing and good accuracy of activity recognition.     

普适计算中一种上下文感知的自适应可信模型

针对普适计算环境中涌现出的行为可信问题,提出了一种适合于普适计算网络环境的上下文感知的自适应可信模型CASATM,该可信模型能够自适应地对不同的服务提供不同层次的安全保障,能有效地对时间、地点、服务内容等上下文感知.同时提出了一种简单高效的风险评估模型来完成对一些完全陌生客体的可信度初始化.仿真实验表明该可信模型能有效地感知上下文并抵抗恶意客体的周期性欺骗行为.     

Reference model of future ubiquitous convergent network and context-aware telecommunication service platform

1 Introduction Future ubiquitous convergent network is a user-centric harmony communication network. It integrates various heterogeneous networks (i.e. mobile/fixed network, Internet, and some emerging networks) and new technologies [1]. The object of ubi…     

Designing viable business models for context-aware mobile services

Technologies of 3G and beyond open up new opportunities to develop and commercialize context-aware services that utilize information like user location and social context. Although initial expectations were high, the adoption and diffusion of context-aware services have thus far been limited. Existing literature points to failing business models to explain part of the disappointing uptake. However, most authors focus on the factors that explain failing business models rather than providing practical design issues to improve business model viability. This paper fills this gap by specifying generic mobile business model design issues for the domain of context-aware services. As such, we provide a well-grounded, holistic overview of design issues that are the most critical in developing viable business models for context-aware services, based on interviews with eighteen esteemed practitioners and academics in the mobile services domain, at CEO and Professor level. Our findings indicate key challenges in the service domain (i.e. defining value adding elements, specifying target groups and generating trust of consumers in the service), the technology domain (i.e. integrating emerging technology platforms and safeguarding privacy and security), the organizational domain (i.e. division of existing and new roles in complex value networks, openness of the value network towards new service providers and governing the activities in the value network) and the financial domain (i.e. pricing; dividing costs and revenues and combining multiple revenue models). Our research has scientific implications, because it applies generic mobile business model theory to the context-aware services domain. In addition, we provide practical clues to practitioners with regard to the design issues on which they should focus while developing more viable context-aware business models.     

基于普适计算的分布式定位设计

普适环境中,定位计算是上下文察觉计算的重要内容。本文提出分布式定位计算的思想,该思想摆脱了以往传统定位中先确定用户坐标再判断其所处区域的繁琐模式,将对用户所处区域的计算分散至底层的感知设备中,减轻了计算设备的计算负担,提高了上下文感知系统的效率,并通过实现该定位设计验证了分布式定位设计的可行性。     

Context-aware communication

This article describes how the changing information about an individual's location, environment, and social situation can be used to initiate and facilitate people's interactions with one another, individually and in groups. Context-aware communication is contrasted with other forms of context-aware computing, and we characterize applications in terms of design decisions along two dimensions: the extent of autonomy in context sensing and the extent of autonomy in communication action. A number of context-aware communication applications from the research literature are presented in five application categories. Finally, a number of issues related to the design of context-aware communication applications are presented.     

基于情境感知的人体经络个性化信息服务研究

由于人体经络系统较为复杂,包含经络、穴位、疾病、脏腑及针灸等方面的大量知识信息,同时用户往往由于兴趣、目的及环境的不同而有不同的信息需求,用户不能有针对性地获取所需的信息。为了增强人体经络系统信息服务的个性化,提高用户的学习效率和使用兴趣,将普适计算中的情境感知计算引入到人体经络系统的个性化信息服务中,应用普适计算、图形图像等先进技术,建立起能够感知用户行为的人体经络系统,为经络的学习和研究提供一种直观便捷的有力工具,同时也为电子商务、信息检索、文献分类和多媒体推荐等领域中的个性化信息服务的研究及应用提供了新的思路。     

Activity Recognition for Context-aware Hospital Applications: Issues and Opportunities for the Deployment of Pervasive Networks

Hospitals are convenient settings for the deployment of context-aware applications. The information needs of hospital workers are highly dependent on contextual variables, such as location, role and activity. While some of these parameters can be easily determined, others, such as activity are much more complex to estimate. This paper describes an approach to estimate the activity being performed by hospital workers. The approach is based on information gathered from a workplace study conducted in a hospital, in which 196 h of detailed observation of hospital workers was recorded. Contextual information, such as the location of hospital workers, artifacts being used, the people with whom they collaborate and the time of the day, is used to train a back propagation neural network to estimate hospital workers activities. The activities estimated include clinical case assessment, patient care, preparation, information management, coordination and classes and certification. The results indicate that the user activity can be correctly estimated 75% of the time (on average) which is good enough for several applications. We discuss how these results can be used in the design of activity-aware applications, arguing that recent advances in pervasive and networking technologies hold great promises for the deployment of such applications.     

HotTown, enabling context-aware and extensible mobile interactive spaces

This article introduces a novel, open, and scalable service architecture for context-aware personal communication. In contrast to the network-centric open service access in third-generation mobile networks, this architecture moves the point of integration for user services out to the mobile devices, where we can create support for context-aware computing and communication. Support for peer-to-peer service negotiation with minimal a priori shared knowledge, context representation, and reasoning about context enables the mobile agents (that represent users and other entities) to be aware of and react to any event and thus context. Hence, the delivery of context-aware applications to users intertwining digital and physical objects in mobile interactive spaces leverages events from sensors, mobility support, and digital entities. Finally, a presentation of our prototype and experiences from the HotTown project demonstrates the feasibility of the approach and provides some examples of the enabled user communication for large-scale mobile networks.     

Converged service opportunities supporting the multi-site corporate enterprise

Convergence in the world of telecommunications offers an excellent opportunity for new context-aware services to serve customers better. Customer service is one of the most expensive corporate investments due to the fact that call centres are costly, service is often labour-intensive, and customer representatives require continual training to handle a broad diversity of service issues. Nevertheless, an emerging class of technologies offers the promise to decrease the cost of offering information and services and to improve service consistency. Examples of these technologies include instant messaging (IM), personalisation tools, case-based reasoning systems and intelligent agents or robots (bots) that effectively mimic human interaction. The popularity of IM has increased considerably in recent years. No longer the province of chatty teenagers, it is currently part and parcel of advanced communications networks at many corporations. IM capabilities can help corporate communications with customers in real time, to solve problems, answer questions, and increase sales and customer satisfaction. This paper investigates the use of IM bots in serving corporate customers on the move, the potential value they offer, as well as forecasting how they may deliver the promised benefits. The paper also discusses a prototype demonstrating the extension of a desktop IM to the mobile platform, coupled with context enablers to provide context-aware information and services delivery.     

基于公平期的循环服务——一种用于ATM网络的简单公平信元调度机制

为了在ATM网络中简洁及公平地实现信元调度,本文提出了一种新的公平服务规划;基于公平期的循环服务（简称为FCRR）,FCRR将理想的公平服务准则与经典循环服务的简单性有机地相结合,以接近于经典循环服务的代价实现了在每个“公平期”上对各用户业务的公平服务。在给出了“公平基”和“公平期”的概念后,我们证明了FCRR在每个“公平期”上服务的公平性,导出了PCRR的最差公平性和信元时延上界,与转交式循环服务（CORR）相比,FCRR具有更好的公平服务特性。相应的模拟分析进一步表明,FCRR的公平性明显优于CORR,并对高速业务具有比CORR更好的时延特性。     

Applying privacy on the dissemination of location information

Recent achievements in the positioning technology enable the provision of location-based services that require high accuracy. On the other hand, location privacy is important, since position information is considered as personal information. Thus, anonymity and location privacy in mobile and pervasive environments has been receiving increasing attention during the last few years, and several mechanisms and architectures have been proposed to prevent “big brother” phenomena. In this paper, we discuss an architecture to shield the location of a mobile user and preserve the anonymity on the service delivery. This architecture relies on un-trusted entities to distribute segments of anonymous location information, and authorizes other entities to combine these portions and derive the actual location of a user. The paper describes how the proposed architecture takes into account the location privacy requirements, and how it is used by the end users’ devices, e.g., mobile phones, for the dissemination of location information to Service Providers. Furthermore, it discusses performance study experiments, based on real location data, and summarizes the threats analysis results.     

The study of youth online: a critical review and agenda

The increasing and pervasive use of online technologies, especially social media, has inspired scholars to investigate how the Internet influences communication. As young people represent the fastest growing adopters of new online technology, much of this research targets youth activity online. But how is the communication discipline taking up this issue, broadly? Typically left to new media and computer-mediated communication scholars, we argue youth online activity raises new and exciting possibilities for researchers across the communication discipline. In this paper, we present a qualitative content analysis of communication research about youth and the Internet. Our analysis of over 700 journal articles provides a clear picture of past and present trends in communication research of youth online activity. Furthermore, we discuss the top four content themes, including: uses and gratifications, engagement, identity, and the uniqueness of youth experience. Critically, we articulate how such research organizes and positions youth in meaningful ways, paving the way for issues of inclusion. We call for a shift from a “difference” framework to one that more explicitly considers “complexity” before suggesting opportunities for future research that crosses and unites subdisciplinary boundaries.     

Enhanced IPACT: solving the over-granting problem in long-reach EPON

In this paper we address an issue referred to as “over-granting problem”, which is inherent in the existing dynamic bandwidth allocation algorithms for Ethernet-based Passive Optical Networks (EPON), in particular when deployed for multi-threaded scheme in long-reach scenario. In order to solve this problem we design a scheme for the algorithm of Interleaved Polling with Adapted Cycle Time (IPACT) with the limited service discipline. We evaluate the proposed scheme through simulations for single-thread and double-thread cases and demonstrate that, the network performance can be significantly improved by our solution in terms of average delay, jitter, and throughput.     

A cross-layer architecture to improve mobile host rate performance and to solve unfairness problem in WLANs

The evolution of the Internet has been mainly promoted in recent years by the emergence and proliferation of wireless access networks towards a global ambient and pervasive network accessed from mobile devices. These new access networks have introduced new MAC layers independently of the legacy “wire-oriented” protocols that are still at the heart of the protocol stacks of the end systems. This principle of isolation and independence between layers advocated by the OSI model has its drawbacks of maladjustment between new access methods and higher-level protocols built on the assumption of a wired Internet. In this paper, we introduce and deliver solutions for several pathological communication behaviors resulting from the maladjustment between WLAN MAC and higher layer standard protocols such as TCP/IP and UDP/IP. Specially, based on an efficient analytical model for WLANs bandwidth estimation, we address in this paper the two following issues: (1) Performance degradation due to the lack of flow control between the MAC and upper layer resulting in potential MAC buffer overflow; (2) Unfair bandwidth share issues between various type of flows. We show how these syndromes can be efficiently solved from neutral “cross layer” interactions which entail no changes in the considered protocols and standards.     

Pervasiveness in a competitive multi-operator environment:the daidalos project

This article briefly describes the EU-funded Daidalos project, which designs and develops a communications infrastructure for next-generation networks to enable personalized, context-aware, composite services to mobile users. The fundamental concepts rely on federation of operators who create a pervasive environment for service provisioning, on integrated mobility, security, virtual identity for users, and resource management. The project validates concepts by means of specification, implementation, and integration in a large research testbed.     

Extracting High-Level Information from Location Data: The W4 Diary Example

Services for mobile and pervasive computing should extensively exploit contextual information both to adapt to user needs and to enable autonomic behavior. To fulfill this idea it is important to provide two key tools: a model supporting context-data representation and manipulation, and a set of algorithms relying on the model to perform application tasks. Following these lines, we first describe the W4 context model showing how it can represent a simple yet effective framework to enable flexible and general-purpose management of contextual information. In particular, we show the model suitability in describing user-centric situations, e.g., describing situations in terms of where a user is located and what he is doing. Then, we illustrate a set of algorithms to semantically enrich W4 represented data and to extract relevant information from it. In particular, starting from W4 data, such algorithms are able to identify the places that matter to the user and to describe them semantically. Overall, we show how the context-model and the algorithms allow to create an high-level, semantic and context-aware diary-based service. This service meaningfully collects and classifies the user whereabouts and the places that the user visited.

SPETA: Social pervasive e-Tourism advisor

Tourism is one of the major sources of income for many countries. Therefore, providing efficient, real-time service for tourists is a crucial competitive asset which needs to be enhanced using major technological advances. The current research has the objective of integrating technological innovation into an information system, in order to build a better user experience for the tourist. The principal strength of the approach is the fusion of context-aware pervasive systems, GIS systems, social networks and semantics. This paper presents the SPETA system, which uses knowledge of the user’s current location, preferences, as well as a history of past locations, in order to provide the type of recommender services that tourists expect from a real tour guide.     

Perfect secrecy cryptosystem with nonuniform distribution of keys

More strictly mathematical concepts of infinite perfect secrecy and random “one-time pad” cryptosystem in theory were presented,and the whole secure communication system was divided into two stages:design of a basic cryptosystem and one of its applications.How to design a basic cryptosystem by using a group of orthogonal Latin squares was first studied and an example to illustrate how to design nonlinear encryption transformations for a basic cryptosystem was given.Then,how to design the sequence of keys by using random method with nonuniform distribution was discussed,and it was strictly proven in theory that the infinite random “one-time pad” cryptosystem based on the designed basic cryptosystem was of perfect secrecy.Since the obtained result generalizes the existing one for random “one-time pad” cryptosystem to be perfect by using a basic cryptosystem with modulo addition,it may be used as a wider ideal simulated prototype to design stream cipher algorithms.Since the number of basic cryptosystems that can be designed is much more than one of the common basic cryptosystems with modulo addition,the obtained result is effective supplement and perfection to mainstream design method for the current stream cryptosystems.     

A group-based security protocol for machine-type communications in LTE-advanced

Machine-type communication (MTC) takes advantage of millions of devices being connected to each other in sensing our environment. A third-generation partnership project has been actively considering MTC as an enabler for ubiquitous computing and context-aware services. Until recently, we have not yet known how to productively manage the signaling traffic from these MTC devices because authentication requirements may impose such large signaling loads that they overwhelm the radio access of 4G cellular networks. This paper proposes the design of an efficient security protocol for MTC. This protocol is designed to be compatible with the incumbent system by being composed of only symmetric cryptography. Efficiency is attained by aggregating many authentication requests into a single one. The security and performance of the new design are evaluated via formal verification and theoretical analysis. Implementation of the proposed protocol in a real LTE-A network is provided through a feasibility analysis undertaken to prove the practicability of the protocol. Based on these evaluations, we contend that the proposed protocol is practical in terms of security and performance for MTC in LTE-Advanced.