Location awareness in ad hoc wireless mobile networks

Networks composed of dynamically repositioning mobile hosts require location awareness to provide new geographic services and to maximize routing efficiency and quality of service. Because wireless networks can operate in a 3D physical environment, exploiting mobile hosts' location information is both natural and inevitable. Emerging geographic services based on mobile ad-hoc networks (manets) must confront several challenges, including how to increase positioning accuracy and how to establish a connection from location information to the vast body of Web data, as in a tour-guide system for example     

物联网中基于RFID的移动标签定位方案

当前基于RFID的定位系统无法使用异构移动阅读器按照分布式策略定位移动标签,且定位精度低下。针对这种情况,提出了LSMT-RFID系统。该系统使用一组异构移动式RFID阅读器来定位移动RFID标签,移动阅读器通过时间约束交错过程展开合作,附近的阅读器通过共享询问信息来相应地估计标签位置,并使用主动和被动协议来确保位置信息的及时传输。基于ns-3的仿真实验来评估方案的定位能力,重点考察了平均定位误差和定位延时。实验结果表明,本方案能实现有效定位。     

基于位置簇的移动生活服务个性化推荐技术

当前的移动推荐系统只将位置信息作为推荐属性处理,弱化了其在推荐中所起的作用,更重要的是忽略了移动生活服务位置相关性和用户空间运动有界性特征。针对该问题,设计了基于位置簇的用户偏好表示模型和移动生活服务个性化推荐算法。该算法通过模糊聚类得到位置簇,使用遗忘因子调节用户在该位置簇对服务资源属性值的偏好,并且采用概率分布和信息熵理论计算属性权重,按位置簇对用户偏好和服务资源进行匹配得到top-N推荐集。由于位置簇的定义,使得算法给出与用户偏好相似度较高的服务资源。案例分析结果符合这一结论,从而验证了算法的有效性和精确性。     

基于位置服务的研究综述

基于位置的服务是指移动终端利用各种定位技术获得当前位置信息,再通过无线通信将这些信息传输给服务提供商,服务提供商根据用户的位置信息以及用户的上下文信息提供个性化的服务。对位置服务按照不同的方面进行了分类,然后分析了基于位置服务中的关键技术,包括定位、信息传输以及位置索引,接着总结了基于位置服务的典型应用,最后指出了存在的一些问题。     

Location-dependent services for mobile users

One of the main issues in mobile services' research (M-service) is supporting M-service availability, regardless of the user's context (physical location, device employed, etc.). However, most scenarios also require the enforcement of context-awareness, to dynamically adapt M-services depending on the context in which they are requested. In this paper, we focus on the problem of adapting M-services depending on the users' location, whether physical (in space) or logical (within a specific distributed group/application). To this end, we propose a framework to model users' location via a multiplicity of local and active service contexts. First, service contexts represent the mean to access to M-services available within a physical locality. This leads to an intrinsic dependency of M-service on the users' physical location. Second, the execution of service contexts can be tuned depending on who is requesting what M-service. This enables adapting M-services to the logical location of users (e.g., a request can lead to different executions for users belonging to different groups/applications). The paper firstly describes the framework in general terms, showing how it can facilitate the design of distributed applications involving mobile users as well as mobile agents. Then, it shows how the MARS coordination middleware, implementing service contexts in terms of programmable tuple spaces, can be used to develop and deploy applications and M-services coherently with the above framework. A case study is introduced and discussed through the paper to clarify our approach and to show its effectiveness.     

基于Android的老人关爱系统

针对日益突出的老人监护需求,设计并实现了基于安卓智能手机的老人关爱系统,系统围绕老人的位置信息采集、传送、处理生成服务三个核心问题,并探讨了基于极光推送的老人救助模式.通过手机自带GPS定位功能实现了位置信息采集,自定义Json数据传送格式、调用百度API处理显示服务,实现了老人实时位置显示、历史轨迹回放、一键报警功能,系统服务端结合极光推送,可以将老人的求助信息快速推送到相关人员手机上,实现了周边救助模式,初步应用表明,该系统具有实时性强,用户参与度高,经济便捷等特点,为老人关爱领域提供了模型参考.     

基于电信数据的室外定位技术研究

越来越多的移动计算依赖位置信息提供基于位置的服务,移动设备的室外定位技术至关重要。目前广为采用的方式是GPS,但移动设备端的GPS位置信息依赖移动设备如手机的GPS传感器获取,电信运营商虽然为用户提供通话和数据服务,却无法获得用户的精确GPS位置。针对这种情况,提出利用手机端和电信基站之间的连接信号数据(简称电信数据),实现移动设备的定位服务。考虑到电信运营商积累了海量的电信数据,因此通过研究基于电信数据的室外定位技术,使得运营商获取用户位置成为可能。提取电信特征数据、以手机所在GPS位置作为标签数据,研究了五种基于机器学习模型的室外定位算法,实现了从基站信号数据到GPS坐标点的预测,通过大量的实验对比了这些方法的定位精度和运行时间、不同数据收集模式的定位精度、不同特征的定位精度以及探索了后处理对定位精度的提升效果。最终通过实验可知,基于栅格化的随机森林分类模型是效果最好的方法,能够达到15~20m的平均误差和10m的中位误差,比前期回归算法在2G和4G数据分别实现了39.46%和54.28%的精度提升,取得与GPS定位接近的定位精度。     

Hybrid indoor and outdoor location services for new generation mobile terminals

In the last years, an increasing interest in location services characterized the market of mobile ubiquitous devices (smartphones, handhelds, etc.). Several technologies and solutions have been developed to determine the position of mobile devices in their operating space, each with its specific degree of precision and accuracy. In this scenario, the ideal location service should be able of tracking the mobile terminal in any place it moves to, both indoors and outdoors. However, while outdoor location services have already achieved a satisfactory degree of technological maturity and effectiveness, a really ubiquitous location service that works satisfactorily in both indoor and outdoor scenarios is not yet available. In order to cope with the above challenge, this work proposes a hybrid location approach designed to choose and switch among multiple positioning technologies supported by the mobile device and available in the surrounding environment, in a dynamic and transparent way during the user movement. It combines signal strength–based fingerprinting techniques for indoor positioning together with traditional GPS-based positioning for the outdoor localization and performs opportunistic technology switching according to a count-and-threshold mechanism. The resulting solution is able to leverage the different features of the wireless networks and of the global positioning technologies, in order to provide ubiquitous location services across indoor and outdoor scenarios, as well as to minimize power consumption of the mobile device.     

基于基站的移动终端定位的研究及应用

随着移动终端、3G网络的快速发展与结合,公众对于获取位置信息的需求迅速增长.基于基站的定位系统的发展是非常有必要的.针对移动网络原理、Android技术进行研究后,提出通过定位软件获取GSM网络中移动终端用户的位置信息,在服务器端对数据保存及处理,最后在电子地图的支持下,为用户提供一种定位服务.经过测试,这种定位服务不仅能给普通群体提供定位和轨迹查询服务,更能免费为老人、孩子等弱势群体的人身安全提供保障.     

面向移动云服务系统的形式化语义描述方法

针对移动云服务系统构建过程中架构设计和语义描述等方面存在的问题,以类型范畴理论为基础,为基于Agent的移动云服务系统建立了一种形式化语义描述模型。Agent作为范畴理论中的对象结点,Agent之间的交互和依赖关系作为态射,将整个云服务系统描述为一个类型范畴图表。在此基础上,对Agent交互与协作、架构设计与精化、Agent迁移、Agent可替代性以及应用请求的可满足性等进行了分析和讨论。该形式化模型增强了系统架构的语义描述能力,有助于对移动云服务系统的规约进行分析和验证。     

面向情境的移动应用研发

移动网络的出现极大推进普适计算发展,智能设备成为生活、工作不可缺少的部分,形成个体随时、随地在线状态,显具身和情境性,形成应用研发新环境,为软件设计理论、方法、技术等层面创新提供条件。基于被誉为认知科学二次革命的具身、分布认知等新思想,情境、认知将成为移动应用创新切入点,为情境矢量化,认知大数据处理提供理论;移动情境是Agent生存数字空间,其设计思想、方法、矢量化技术直接关系到服务品质。以物流行业移动应用为例,阐述物流情境矢量化架构,认知动力系统结构。     

A synthetical development approach for rehabilitation assistive smart product–service systems: A case study

Digital transformation (DT), the combination of information, computing, communication and connectivity technologies, which has triggered an effective upgrade of different aspects of market strategy, customer experience etc. Nowadays, rehabilitation assistive devices (RADs) are evolving to be more digital, intelligent and personalized. Digitalization and servitization have fostered to an emerging business model—the smart product–service system (Smart PSS). Therefore, DT of the RADs’ industry advocates not only the design of products and functions, the more important is the management of service processes and resource integration. With the increase in the elderly and disabled population, the requirement for RADs is becoming more urgent. However, research on Smart PSS for RAD is still limited. The rehabilitation assistive smart product–service systems (RASPSS) was introduced into the development of RADs based on the “Design and Management of DT” strategy through the service design of assistive devices and user requirements analysis. Further, an integrated design of RAD and Smart PSS has been created, a development method of RASPSS proposed, the theoretical model of the Smart PSS based on RADs built. To specify the service framework, this case study discusses the development of a home rehabilitation assistive system for femoral stem fracture patients. This paper evaluates the usability of the system, the results of which prove usability and effectiveness of the RASPSS development method. The RASPSS development model is designed to meet needs of stakeholders, improve the user rehabilitation experience, promote the service innovation of Smart PSS, bring certain market benefits of rehabilitation aids and create social value.     

A hybrid positioning system for technology‐independent location‐aware computing

Location‐aware computing is a form of context‐aware mobile computing that refers to the ability of providing users with services that depend on their position. Locating the user terminal, often called positioning, is essential in this form of computing. Towards this aim, several technologies exist, ranging from personal area networking, to indoor, outdoor, and up to geographic area systems. Developers of location‐aware software applications have to face with a number of design choices, that typically depend on the chosen technology. This work addresses the problem of easing the development of pull location‐aware applications, by allowing uniform access to multiple heterogeneous positioning systems. Towards this aim, the paper proposes an approach to structure location‐aware mobile computing systems in a way independent of positioning technologies. The approach consists in structuring the system into a layered architecture, that provides application developers with a standard Java Application Programming Interface (JSR‐179 API), and encapsulates location data management and technology‐specific positioning subsystems into lower layers with clear interfaces. In order to demonstrate the proposed approach we present the development of HyLocSys. It is an open hybrid software architecture designed to support indoor/outdoor applications, which allows the uniform (combined or separate) use of several positioning technologies. HyLocSys uses a hybrid data model, which allows the integration of different location information representations (using symbolic and geometric coordinates). Moreover, it allows support to handset‐ and infrastructure‐based positioning approaches while respecting the privacy of the user. The paper presents a prototypal implementation of HyLocSys for heterogeneous scenarios. It has been implemented and tested on several platforms and mobile devices. Copyright © 2009 John Wiley & Sons, Ltd.     

Toward an execution system for self-healing workflows in cyber-physical systems

Cyber-physical systems (CPS) represent a new class of information system that also takes real-world data and effects into account. Software-controlled sensors, actuators and smart objects enable a close coupling of the cyber and physical worlds. Introducing processes into CPS to automate repetitive tasks promises advantages regarding resource utilization and flexibility of control systems for smart spaces. However, process execution systems face new challenges when being adapted for process execution in CPS: the automated processing of sensor events and data, the dynamic invocation of services, the integration of human interaction, and the synchronization of the cyber and physical worlds. Current workflow engines fulfill these requirements only to a certain degree. In this work, we present PROtEUS—an integrated system for process execution in CPS. PROtEUS integrates components for event processing, data routing, dynamic service selection and human interaction on the modeling and execution level. It is the basis for executing self-healing model-based workflows in CPS. We demonstrate the applicability of PROtEUS within two case studies from the Smart Home domain and discuss its feasibility for introducing workflows into cyber-physical systems.     

Smart devices and spaces for pervasive computing

Applications and services for pervasive computing have been dramatically grown and have contributed extensively to our daily experiences in recent years. Smart systems, devices, and spaces are proactive for ubiquitous and pervasive computing. Smart information technology (IT) is also an outcome of the state of the art and novel mobile and ubiquitous computing technologies that include highly capable handheld device, pervasive and personal device, etc. This special issue will be a trigger for further related research and technology improvements in pervasive and ubiquitous computing using smart devices and services. This special issue called for original papers describing the latest developments, trends, and solutions of smart devices and spaces for pervasive computing including real-time operating systems (OS), tiny OS and middleware supports, mobile system performance, trustworthy Internet and communications, agents and mobile and pervasive services, among others. In particular, this special issue focuses on a remote control and media-sharing system, flash storage-based smart system, heterogeneous mobile OS, and prediction and auto-execution system for pervasive computing.     

基于WLAN移动定位的个性化商品信息推荐平台

随着WLAN在室内环境的日益普及,基于现代的移动设备可以方便实时地获取各种有价值的WLAN数据,这对我们识别个体日常生活中的多样化行为提供了前所未有的机会。近年来,用户的兴趣点与行为模式挖掘等领域日益引起各界的广泛关注,设计了一套基于室内定位的推荐系统,基于用户的历史访问记录,实现从过载的信息中识别出用户感兴趣的内容。现有的位置服务通常只针对用户的室外位置数据,缺乏对室内数据的挖掘分析,忽略了室内位置数据中蕴含的大量语义信息。利用室内定位技术获取用户在商场中的活动轨迹,根据用户去过的店铺和浏览过的商品等历史信息,估算用户的兴趣爱好并进而向用户个性化地推荐感兴趣的商品,基于以上思路设计实现了一套基于室内定位和微信平台的个性化商品推荐系统。     

Relational Model for Robotic Semantic Navigation in Indoor Environments

The emergence of service robots in our environment raises the need to find systems that help the robots in the task of managing the information from human environments. A semantic model of the environment provides the robot with a representation closer to the human perception, and it improves its human-robot communication system. In addition, a semantic model will improve the capabilities of the robot to carry out high level navigation tasks. This paper presents a semantic relational model that includes conceptual and physical representation of objects and places, utilities of the objects, and semantic relation among objects and places. This model allows the robot to manage the environment and to make queries about the environment in order to do plans for navigation tasks. In addition, this model has several advantages such as conceptual simplicity and flexibility of adaptation to different environments. To test the performance of the proposed semantic model, the output for the semantic inference system is associate to the geometric and topological information of objects and places in order to do the navigation tasks.     

A Robust Missing Data-Recovering Technique for Mobility Data Mining

Based on location information, users’ mobility profile building is the main task for making different useful systems such as early warning system, next destination and route prediction, tourist guide, mobile users’ behavior-aware applications, and potential friend recommendation. For mobility profile building, frequent trajectory patterns are required. The trajectory building is based on significant location extraction and the user’s actual movement prediction. Previous works have focused on significant places extraction without considering the change in GSM (global system for mobile communication) network and is based on complete data analysis. Since network operators change the GSM network periodically, there are possibilities of missing values and outliers. These missing values and outliers must be addressed to ensure actual mobility and for the efficient extraction of significant places, which are the basis for users’ trajectory building. In this paper, we propose a methodology to convert geo-coordinates into semantic tags and we also purposed a clustering methodology for recovering missing values and outlier detection. Experimental results prove the efficiency and effectiveness of the proposed scheme.