面向智能移动设备的血氧饱和度检测方法分析

由于智能移动设备的蓬勃发展和人们对于自身健康状况的高度关注,通过智能移动设备监测身体指标和健康状况正逐渐成为一个研究热点.血氧饱和度是指血液中氧合血红蛋白在所有血红蛋白中的比例,它是呼吸系统和循环系统的重要生理参数之一,可以反映相关人群的病情变化及身体健康情况等.一般传统血氧饱和度的检测方法需要红外光的支持,而目前的智能移动设备没有红外光发射和接收模块,鉴于此,研究了面向仅具有摄像头和可见光源的移动设备血氧饱和度检测方法.通过分析传统光学模型直接应用于移动设备后存在的问题,提出全新的面向移动设备的血氧饱和度检测模型,并研究其中必备的摄像头成像基线漂移问题的修正算法.提出的模型和方法可以支持许多与血氧饱和度检测相关的应用,并启发相关的人机交互研究.     

Architecture for mobile group communication in campus environment

The demand for group communication using smart devices in campus environment is increasing rapidly. In this paper, we design an architecture for a mobile group communication system (MGCS) on campus by using Wi-Fi networks and smart devices. The architecture is composed of a web-based system and a smart device based mobile system. Through the systems, users on campus create community/mobile group, maintain dynamic group membership, and reliably deliver the message to other users. We use the common features of many smart devices to develop a prototype that works on off-the-shelf hardware. In the experimental section, we demonstrate our system using various real scenarios which can occur in university campuses.     

Sensor Web支持下的租赁车辆远程监控系统设计与实现

对于大型的租赁公司来说,租赁车辆类型多种多样,不同车型安装的定位设备多来自于不同的生产商,这些设备在数据传输协议和数据存储格式上存在很大差异,导致资源难以互通互联。现有的关于租赁车辆远程监控方案只是针对单一定位设备进行数据管理,难以实现多源定位设备获取数据的融合。为解决以上问题,开展多源定位设备接入管理研究,构建一个兼容多源定位设备的租赁车辆远程监控系统。通过对GT220和GT710这两种来自不同厂商的定位设备建模注册,利用Sensor Web标准中的传感器观测服务（SOS,Sensor Observation Service）对多源定位设备及其观测信息进行统一管理;基于Java、AJAX、MINA框架等技术研发了租赁车辆远程监控系统;基于HTML、CSS、JavaScript等技术开发了简洁友好的前端监控页面,实现了车辆实时位置查询、历史轨迹回放、电子围栏报警等功能。对GT220和GT710两种定位设备的仿真实验表明,该系统能准确获取租赁车辆的定位信息,并实现实时跟踪、越界报警。     

Mobile digcovery: discovering and interacting with the world through the Internet of things

The application of Internet-enabled devices in the real world for the development of Smart Cities, environmental monitoring, bus tracking, and parking requires scalability, extensibility, and integration of emerging resources to reach a suitable ecosystem for data acquisition and interaction with citizens. Internet of things needs to offer efficient support for global communications and access to services and information. It needs to enable homogeneous and seamless machine-to-machine communication for different solutions and applications. This work presents an homogeneous and suitable mechanism for global resource discovery, device access for deployed smart objects in different scenarios, and sensors and devices from end users (participative sensing). The integration of legacy and sensors already available from smart buildings and smart objects is presented. For this purpose, a resolution infrastructure called “digcovery” is defined for maximizing efficiency and sustainability of deployments. Digcovery architecture offers the framework to allow users to register/include their own sensors into a common infrastructure and access/discover the available resources through mobile digcovery. Mobile digcovery exploits the context-awareness, geo-location, and identification technologies available in mobile platforms such as smartphones to discover, interact, and access the resources through its ElasticSearch engine.     

一种高效的移动Agent控制机制

在传统分布式系统中,由于任务之间具有明确的依赖关系,所以有很多方法来实现任务的控制。但这些方法已经不适于移动Agent环境,其根本原因在于移动Agent之间不存在那种“自然”的依赖关系。文章提出了一种移动Agent的控制机制,它基于以AgentTracer为中心以Agent影子为辅助的Agent追踪方法,结合能量概念来实现移动Agent的控制,并说明这种方法是高效的。     

Privacy in targeted advertising on mobile devices: a survey

Targeted advertising has transformed the marketing landscape for a wide variety of businesses, by creating new opportunities for advertisers to reach prospective customers by delivering personalised ads, using an infrastructure of a number of intermediary entities and technologies. The advertising and analytics companies collect, aggregate, process, and trade a vast amount of users’ personal data, which has prompted serious privacy concerns among both individuals and organisations. This article presents a comprehensive survey of the privacy risks and proposed solutions for targeted advertising in a mobile environment. We outline details of the information flow between the advertising platform and ad/analytics networks, the profiling process, the measurement analysis of targeted advertising based on user’s interests and profiling context, and the ads delivery process, for both in-app and in-browser targeted ads; we also include an overview of data sharing and tracking technologies. We discuss challenges in preserving the mobile user’s privacy that include threats related to private information extraction and exchange among various advertising entities, privacy threats from third-party tracking, re-identification of private information and associated privacy risks. Subsequently, we present various techniques for preserving user privacy and a comprehensive analysis of the proposals based on such techniques; we compare the proposals based on the underlying architectures, privacy mechanisms, and deployment scenarios. Finally, we discuss the potential research challenges and open research issues.

     

Accurate overlaying for mobile augmented reality

Mobile augmented reality requires accurate alignment of virtual information with objects visible in the real world. We describe a system for mobile communications to be developed to meet these strict alignment criteria using a combination of computer vision, inertial tracking and low-latency rendering techniques. A prototype low-power and low-latency renderer using an off-the-shelf 3D card is discussed.     

First Person Indoor/Outdoor Augmented Reality Application: ARQuake

This paper presents a first person outdoor/indoor augmented reality application ARQuake that we have developed. ARQuake is an extension of the desktop game Quake, and as such we are investigating how to convert a desktop first person application into an outdoor/indoor mobile augmented reality application. We present an architecture for a low cost, moderately accurate six degrees of freedom tracking system based on GPS, digital compass, and fiducial vision-based tracking. Usability issues such as monster selection, colour, input devices, and multi-person collaboration are discussed.     

面向富互联网应用的计算任务动态迁移机制

富互联网应用(rich Internet application,RIA)目前已经成为重要的应用模式.随着信息技术日益泛在化和服务化,富互联网应用也开始在移动设备之上运行.然而,由于设备计算能力的不足,很可能出现部分代码无法在富客户端顺利运行的情况.提出面向富互联网应用的计算任务动态迁移机制,在应用运行过程中,动态地将...     

An expert system development tool for non AI experts

From their first applications until now, expert systems have provided solutions to multiple problems in companies of all types. With the advent of the Internet and its evolution, web-based expert systems have become very important. Moreover, the arrival of new mobile devices that can connect to the Internet has made it easy to access information from any place at any time, creating new requirements for web systems. The creation of an expert system normally requires certain technical knowledge and concepts of artificial intelligence (AI). If the need to make it accessible through the Internet is added, the degree of technical knowledge necessary for its development is greater, entailing an unaffordable cost for small and medium-sized companies. In this article, we present a tool for the development of web-based expert systems which permits the expert to define the knowledge without having to know anything about AI. The proposed inference engine is integrated in a web server through which it can be accessed from any device with an Internet connection. Finally, the article presents examples of developments achieved via the proposed framework.     

Maximizing Water Surface Target Localization Accuracy Under Sunlight Reflection with an Autonomous Unmanned Aerial Vehicle

Reflected sunlight can significantly impact the effectiveness of vision-based object detection and tracking algorithms, especially ones developed for an aerial platform operating over a marine environment. These algorithms often fail to detect water surface objects due to sunlight glitter or rapid course corrections of unmanned aerial vehicles (UAVs) generated by the laws of aerodynamics. In this paper, we propose a UAV path planning method that maximizes the stationary or mobile target detection likelihood during localization and tracking by minimizing the sunlight reflection influences. In order to better reduce sunlight reflection effects, an image-based sunlight reflection reception adjustment is also proposed. We validate our method using both stationary and mobile target tracking tests.     

Immersive interactive reality: Internet-based on-demand VR for cultural presentation

This paper presents an Internet-based virtual reality technology, called panoramic broadcasting (PanoCAST) where multiple viewers share an experience yet each having full control of what they see independent from other viewers. Our solution was developed for telepresence-based cultural presentation and entertainment services. The core architecture involves a compact spherical vision system that compresses and transmits data from multiple digital video sources to a central host computer, which in turn distributes the recorded information among multiple render- and streaming servers for personalized viewing over the Internet or mobile devices. In addition, using advanced computer vision, tracking and animation features, the PanoCAST architecture introduces the notion of Clickable Content Management (CCM), where each visual element in the image becomes a source for providing further information, educational content and cultural detail. Key contributions of our application to advance the state-of-the-art include bringing streaming panoramic video onto mobile platforms, an advanced tracking interface to turn visual elements into sources of interaction, physical simulation to combine the benefits of panoramic video with that of 3D models and animated, photo-realistic faces to help users express their emotions in shared online virtual cultural experiences as well as a feedback mechanism in such environments. Therefore, we argue that the PanoCAST system offers a low-cost and economical solution for personalized content distribution and as such it can serve as a unified basis for novel applications many of which are demonstrated in this paper.     

What input errors do you experience? Typing and pointing errors of mobile Web users

Small devices such as personal digital assistants (PDAs) are widely used to access the World Wide Web (Web). However, accessing the Web from small devices is affected by poor interface bandwidth, such as small keyboards and limited pointing devices. There is little empirical work investigating the input difficulties caused by such insufficient facilities, however, anecdotal evidence suggests that there is a link between able-bodied users of the mobile Web and motor impaired users of the Web on desktop computers. This being the case we could transfer the solutions which already exists for motor impaired users into the mobile Web and vice versa. This paper presents a user study that investigates the input errors of mobile Web users in both typing and pointing. The study identifies six types of typing errors and three types of pointing errors shared between our two user domains. We find that mobile Web users often confuse the different characters located on the same key, press keys that are adjacent to the target key, and miss certain key presses. When using a stylus, they also click in the wrong places, slide the stylus during multiple clicks, and make errors when dragging. Our results confirm that despite using different input devices, mobile Web users share common problems with motor impaired desktop users; and we therefore surmise that it will be beneficial to transfer available solutions between these user domains in order to address their common problems.     

GPS-based Clock Synchronization in a Mobile,Distributed Real-Time System

In a vehicle tracking system computers aboard moving vehicles determine periodically their geographical position and transmit it to a control center. This paper presents a commercial vehicle tracking system as an example of a distributed real-time system with mobile components and focuses on the issue of clock synchronization. The mobile components of the system obtain highly accurate timing information from the Global Positioning System which is used to synchronize their local clocks to UTC world time. Thus a tight clock synchronization is achieved without imposing additional load on the communication channels of the system.     

Spatial audio in small screen device displays

Our work addresses the problem of (visual) clutter in mobile device interfaces. The solution we propose involves the translation of technique-from the graphical to the audio domain-for expliting space in information representation. This article presents an illustrative example in the form of a spatialisedaudio progress bar. In usability tests, participants performed background monitoring tasks significantly more accurately using this spatialised audio (a compared with a conventional visual) progress bar. Moreover, their performance in a simultaneously running, visually demanding foreground task was significantly improved in the eye-free monitoring condition. These results have important implications for the design of multi-tasking interfaces for mobile devices.     

移动设备视线跟踪技术研究进展

针对移动设备视线跟踪技术研究现状进行了综述,介绍了视线跟踪技术的发展及移动设备的资源劣势,将移动设备视线跟踪技术分为利用自身集成硬件和使用外接硬件设备两类,并分别进行了说明。最后,总结分析了移动设备视线跟踪存在的问题,并对其未来发展及研究方向进行展望。     

Real-time people tracking for mobile robots using thermal vision

This paper presents a vision-based approach for tracking people on a mobile robot using thermal images. The approach combines a particle filter with two alternative measurement models that are suitable for real-time tracking. With this approach a person can be detected independently from current light conditions and in situations where no skin colour is visible. In addition, the paper presents a comprehensive, quantitative evaluation of the different methods on a mobile robot in an office environment, for both single and multiple persons. The results show that the measurement model that was learned from local grey-scale features could improve on the performance of the elliptic contour model, and that both models could be combined to further improve performance with minimal extra computational cost.     

Load Balancing in IEEE 802.11 Networks

Because wireless stations independently select which access points to camp on, the total wireless station traffic on all available IEEE 802.11 network APs might be unevenly distributed. This load-balancing problem can lead to overloading and network congestion. This survey examines the problem, along with state-of-the-art network- and wireless-station-based solutions. It also presents experimental results using off-the-shelf IEEE 802.11 devices. As the results show, effectively balancing AP traffic loads can increase overall system throughputs.     

Trajectory Tracking Controller Design for Unmanned Vehicles: A New Methodology

A major issue in the automatic guidance of vehicles is the design of control laws dedicated to the specific mobile platform used. Thus, if the model associated with the mobile platform or its constraints change, a new control law must be designed. In this paper, the problem of designing trajectory tracking controllers for unmanned vehicles is addressed. The methodology proposed here is an algebraic approach for obtaining optimum and stable trajectory tracking controllers for nonholonomic vehicles. Such an algebraic formulation makes the proposal suitable for embedded applications. The stability and optimality of the proposed controllers design method is theoretically proven for both bicycle‐type and unicycle‐type mobile robots, although the methodology can be extended to other types of unmanned vehicles. Four tests were carried out in this work in order to show the advantages of the proposal: the step discontinuity test, the curvature test, the real world test, and navigation under disturbances in the control actions. The results obtained were compared with four trajectory tracking controllers previously published in the literature. Additionally, an agricultural application is included in order to show the performance of the proposed controller when applied to a service unit within an agricultural environment. Field experiments demonstrating the capabilities of our proposal are also reported and discussed.     

Detecting structural anomalies of quadcopter UAVs based on LSTM autoencoder

Detecting a structural anomaly, such as a damaged propeller or motor, is crucial for mission-critical operation of unmanned aerial vehicles (UAVs). The existing solutions often fail to detect structural anomalies because the pre-defined parameters required for the solution are limited in reflecting the flight pattern or the external environment, such as wind conditions. In this paper, we propose a method for detecting structural anomalies in quadcopter UAVs, using only regular data and specifically considering flight patterns and runtime flight conditions. To this end, we employ a long short-term memory (LSTM) autoencoder model to learn complex features of regular flight data. While flying the UAV, the trained model estimates the degree of outlierness of the incoming data and assesses abnormal behavior of UAV by adaptively considering its movement. This way, the proposed method accurately detects structural anomalies in UAVs regardless of the runtime environment or flight mission. Our experiment results with an off-the-shelf UAV show that the proposed approach detects diverse structural anomalies by an average of 98.6% specificity and 90.3% sensitivity.