普适计算及其定位感知系统

普适计算的目的是为了使计算机更好地为人类服务，提高人们的生活质量。普适计算中的定位感知系统是普适计算研究中的核心部分之一，如何确定室内用户的动态位置信息，如何主动向用户提供各种所需的信息，这些都是其研究话题。给出了一种自行设计的普适计算室内定位感知系统的最小功能模型。     

Location-Aware Tools for Improving Public Transit Usability

Real-time arrival information, immediately available on mobile devices, can significantly enhance the usability of public transit systems. The OneBusAway system provides just such information to more than 7,000 Seattle-area bus riders per day. The authors describe a new location-aware native iPhone application for OneBusAway that provides bus stop and arrival information tailored to the user's location. Results from survey and user-study evaluations demonstrate quicker access to data using the location-aware tool. In addition, data for OneBusAway users as a whole show strikingly positive changes in rider satisfaction, the number of transit trips per week, reduced wait time at bus stops, and increased walking. The positive results also hold for the location-aware version users, suggesting the possibility of even further gains.     

User needs for location-aware mobile services

Mobile contexts of use vary a lot, and may even be continuously changing during use. The context is much more than location, but its other elements are still difficult to identify or measure. Location information is becoming an integral part of different mobile devices. Current mobile services can be enhanced with location-aware features, thus providing the user with a smooth transition towards context-aware services. Potential application fields can be found in areas such as travel information, shopping, entertainment, event information and different mobile professions. This paper studies location-aware mobile services from the user's point of view. The paper draws conclusions about key issues related to user needs, based on user interviews, laboratory and field evaluations with users, and expert evaluations of location-aware services. The user needs are presented under five main themes: topical and comprehensive contents, smooth user interaction, personal and user-generated contents, seamless service entities and privacy issues.     

普适计算中的上下文及纯方位定位模型

室内高精度定位问题是普适计算中位置感知研究的首要难题。介绍了普适计算中上下丈的概念,就上下文中的位置问题进行了探讨。通过分析目前室内定位中存在的问题,给出了一种利用红外无源定位技术定位的模型,通过测得的方位角计算出用户的位置。对该模型进行了证明,证明结果显示该模型可以定出目标的准确位置。     

Rendezvousing with location-aware devices: Enhancing social coordination

Emerging technologies such as location-awareness devices have the potential to significantly impact users' social coordination, particularly while rendezvousing. It is important that we explore how new technologies influence social behaviours and communication in order to realize their full potential. This paper presents a field study investigating the use of mobile location-aware devices for rendezvous activities. Participants took part in one of three mobile device conditions (a mobile phone, a location-aware handheld, or both a mobile phone and a location-aware handheld) and completed three rendezvousing scenarios. The results reveal key differences in communication patterns between the mediums, as well as the potential strengths and limitations of location-aware devices for social coordination. The paper concludes with a discussion of relevant design issues drawn from observations gathered during the field study.     

The design of a handheld,location-aware guide for indoor environments

Because of the growing spread of mobile and small devices (like PDAs, mobile phones, etc.), designers and developers of interactive systems have to consider user mobility and the dynamic context of use. In this paper we discuss the design criteria we have defined for developing handheld location-aware systems for indoor environments. We analyse some of the technologies currently available for this purpose and examine how to use them in order to obtain location-dependent information. We report on our experience in designing a location-aware guide for museum visitors and identify possible design criteria for this type of system, which uses automatic detection of a change in environment to trigger the presentation of multi-modal, context-dependent information through a hand-held guide.     

ActiveCampus: experiments in community-oriented ubiquitous computing

The continuing proliferation of handheld computing devices offers a new platform for mobile computing applications that could enrich our experience of the world around us. Yet many questions about realizing this vision remain open. We have been investigating these questions at the University of California, San Diego, through the ActiveCampus Project. ActiveCampus explores technologies that can enrich the learning community in the midst of these changes. It explores wireless context-aware computing as a means to enhance the "learning community" experience of a large urban university. We have tested two applications: ActiveClass supports classroom activities, such as asking questions during a lecture, and ActiveCampus Explorer supports context-aware activities, such as instant messaging and location-aware maps annotated with dynamic hyperlinked information.     

A location model for smart environments

This paper presents a location model for location-aware and user-aware services in smart environments. It can be dynamically organized like a tree based on geographical containment, such as that in a user–room–floor–building hierarchy and each node in the tree can be constructed as an executable software component. The model is unique in existing approaches because it enables location-aware services to be managed without any database servers, it can be managed by multiple computers, and it can provide a unified view of the locations of not only physical entities and spaces, including users and objects, but also computing devices and services. A prototype implementation of this approach was constructed on a Java-based mobile agent system. This paper presents the rationale, design, implementation, and applications of the prototype system.     

Prototypical implementation of location-aware services based on a middleware architecture for super-distributed RFID tag infrastructures

We provide evidence of the feasibility and effectiveness of a middleware architecture for mobile devices (MoDs), which employs dense distributions of small computerized entities for providing fault-tolerant location-aware services. We do so by describing exemplary implementations based on radio frequency identification as an enabling technology. Firstly, we present prototypical implementations of the hardware abstraction layer and of selected core middleware services. The latter enable a MoD to store and retrieve data and position information in physical places in a fault-tolerant manner, and to identify places based on a location abstraction which is robust against failure of individual tags. Secondly, we investigate the feasibility of some higher-level services and applications by developing and evaluating prototypical systems for tracing and tracking, self-positioning, and collaborative map-making.

AniDiary: Daily Cartoon-Style Diary Exploits Bayesian Networks

AniDiary (Anywhere Diary) uses Bayesian networks to automatically detect landmark events and summarize a user's daily life in a cartoon-style diary. Our goal was to summarize a given user's daily life with a cartoon-style diary based on information collected from mobile devices such as smart phones. Our system, AniDiary (Anywhere Diary), addresses two main problems of typical diary systems-the huge number of events originating from the real-life log and the awkward presentation of the output. Using modular Bayesian networks, AniDiary can detect and visualize landmarks (relevant or novel events) and transform numerous logs into user-friendly cartoon images. The cartoons provide a good starting point for fine-grained searches of detailed information. For example, users can link each cartoon to rich media (photos or videos) that offer more details, reducing the search space and letting users easily recall the linked details.     

A Web-based nomadic computing system

CoolTown offers a Web model for supporting nomadic users, based on the convergence of Web technology, wireless networks and portable devices. This paper describes how CoolTown ties Web resources to physical objects and places, and how users interact with resources using the information appliances they carry, from laptops to smart watches. Enabling the automatic discovery of URLs from our physical surroundings, and using localized Web servers for directories, we create location-aware but ubiquitous systems. On top of this infrastructure we leverage device connectivity to support communication services.     

Rover: scalable location-aware computing

All the components necessary for realizing location-aware computing are available in the marketplace today. What has hindered the widespread deployment of location-based systems is the lack of an integration architecture that scales with user populations. The authors have completed the initial implementation of Rover, a system designed to achieve this sort of integration and to automatically tailor information and services to a mobile user's location. Their studies have validated Rover's underlying software architecture, which achieves system scalability through high-resolution, application-specific resource scheduling at the servers and network. The authors believe that this technology will greatly enhance the user experience in many places, including museums, amusement and theme parks, shopping malls, game fields, offices, and business centers. They designed the system specifically to scale to large user populations and expect its benefits to increase with them.     

Location-Aware Computing, Virtual Networks

This issue includes four works in process on issues and applications in location-aware computing: letting users set and control privacy policies when they use location-aware applications, cold-starting recommender systems for mobile location-aware services, aggregating contextual information for location-based applications, and applying location-based services to public transportation environments. The department also includes a report on lightweight virtualization of low-power wireless personal area networks.     

An Ecosystem for Learning and Using Sensor-Driven IM Status Messages

The Nomatic prototype system and communications ecosystem automatically infers users' place, activity, and availability from sensors on their handheld devices or laptop computers and then reports this information to their instant-messaging contacts.In our system, Nomatic (nomad and automatic), we explore a way to amplify and leverage this passive style of content creation by focusing on status messages. These short bits of text are usually created by users in the context of small communities of people who monitor each other for playor work-related distributed coordination. Status messages appear in instant-messaging (IM) clients as short customizable phrases such as "at lunch" or "out of the office." Commercial services also provide facilities for communicating status without IM (for example, Facebook, Twitter, and Jaiku). By simply attaching sensor data to the status information that users enter in IM, we can create a rich ecosystem of context-aware applications that benefit users. At the most basic level, keeping status content up to date helps mitigate the increasing problem of interruptions in mobile communications, but there are many other potential uses of such data. To be effective, we must keep this ecosystem in balance by supporting the user's ability to provide status information, supporting other users' ability to understand that data, and effectively motivating both types of users to keep their status information accurate.     

MCSM:一种基于移动设备的上下文感知中间件

提出一种针对移动设备的上下文感知中间件MCSM(Mobile Context Sensing Middleware).MCSM可以动态地感知当前移动设备的内外部计算环境及用户活动等上下文信息,并以统一的接口将感知到的上下文数据提供给上层应用程序.为了克服外部传感器数据的高异构性,MCSM采用了一种基于XML的上下文数据描述语言CDDL.基于MCSM的原型系统表明,MCSM具有良好的运行效率和可扩展性,并可显著提高上下文应用程序的开发效率.     

Employing computational intelligence to generate more intelligent and energy efficient living spaces

Our living environments are being gradually occupied with an abundant number of digital objects that have networking and computing capabilities. After these devices are plugged into a network, they initially advertise their presence and capabilities in the form of services so that they can be discovered and, if desired, exploited by the user or other networked devices. With the increasing number of these devices attached to the network, the complexity to configure and control them increases, which may lead to major processing and communication overhead. Hence, the devices are no longer expected to just act as primitive stand-alone appliances that only provide the facilities and services to the user they are designed for, but also offer complex services that emerge from unique combinations of devices. This creates the necessity for these devices to be equipped with some sort of intelligence and self-awareness to enable them to be self-configuring and self-programming. However, with this ＂smart evolution＂, the cognitive load to configure and control such spaces becomes immense. One way to relieve this load is by employing artificial intelligence （AI） techniques to create an intelligent ＂presence＂ where the system will be able to recognize the users and autonomously program the environment to be energy efficient and responsive to the user＇s needs and behaviours. These AI mechanisms should be embedded in the user＇s environments and should operate in a non-intrusive manner. This paper will show how computational intelligence （CI）, which is an emerging domain of AI, could be employed and embedded in our living spaces to help such environments to be more energy efficient, intelligent, adaptive and convenient to the users.     

Integrated location aware medical care services

The advent of Mobile technologies has defined ways for providing better flexibility in communication, collaboration and information sharing through wireless medium using portable mobile devices. Technologies allow users to have anytime, anywhere access to information and applications. Specifically, location-aware mobile service has become the most essential component in dealing with mobile based applications. Mobile health care is one such promising area where mobile technologies are highly useful to provide services to the affected people. Worldwide the investment towards mobile health care applications is tremendously increasing. The significance of SMS, sensors, agent’s technologies is widely seen in most of the health care projects. This paper focuses on a system called LAMECS (Location Aware MEdical Care Services) which helps the needy people at the right time. The major focus of LAMECS is to provide timely facilities to people in the mobile based networked environment. Especially, the key objectives are to reduce the time taken to inform the service providers about the situation and to initiate the health care services at an early stage.     

P3 systems: putting the place back into social networks

The availability of technologies enables a new class of location-aware information systems that link people-to-people-to-geographical-places (P3 systems). P3 systems can strengthen the relationship between social networks and physical places. They can also help individuals leverage location information to make new social ties and coordinate interactions that reinforce existing ties. Using the P3 systems framework, we describe the design space for location-aware community systems and important socio-technical challenges and opportunities.     

一种基于奇异值分解的双语信息过滤算法

本文提出了一种基于SVD(奇异值分解)的双语信息过滤算法,将双语文档进行了统一的表示,使得适应于单语过滤的算法可以方便地用于双语过滤,同时对文档向量进行了压缩,滤去了噪声。在应用方面,将双语过滤算法用于互联网上的个性化主动信息过滤。     

High-precision identification of contextual information in location-aware engineering applications

This paper presents research that investigated algorithms for high-precision identification of contextual information in location-aware engineering applications. The primary contribution of the presented work is the design and implementation of a dynamic user-viewpoint tracking scheme in which mobile users’ spatial context is defined not only by their position (i.e., location), but also by their three-dimensional head orientation (i.e., line of sight). This allows the identification of objects and artifacts visible in a mobile user’s field of view with much higher accuracy than was possible by tracking position alone. For outdoor applications, a georeferencing based algorithm has been developed using the Global Positioning System (GPS) and magnetic orientation tracking devices [5] to track a user’s dynamic viewpoint. For indoor applications, this study explored the applicability of wireless technologies, in particular Indoor GPS, for dynamic user position tracking in situations where GPS is unavailable. The objectives of this paper are to describe the details of the three-stage-algorithm that has been designed and implemented, and to demonstrate the extent to which positioning technologies such as GPS and Indoor GPS can be used together with high-precision orientation trackers to accurately interpret the fully-qualified spatial context of a mobile user in challenging environments such as those found on construction sites. The obtained results highlight the potential of using location-aware technologies for rapidly identifying and retrieving contextual information in engineering applications.