Discovering determinants of users perception of mobile device functionality fit

In recent years, there has been an explosive growth in the use of mobile devices. The ubiquitous and multifunctional nature of these devices with internet connectivity and personalization features make them a unique context to investigate what factors shape mobile users perception of their mobile device functionality fit with their needs. In order to answer this question, we proposed a research model in which we introduced multifunctional use and perceived device-functionality fit as two new constructs. The results of our study show that a significant portion of individuals’ perceived device-functionality fit can be explained by their perceived enjoyment, perceived ease of use, perceived usefulness, and symbolic value of the device. In terms of the theoretical contribution, our research suggests revamping the concept of device-functionality fit when it comes to mobile devices by accounting for both hedonic and utilitarian aspects of mobile devices. In terms of practical implications, our study highlights the importance of the social image that mobile devices create in the society for their users as well as the importance of look-and-feel aspects of mobile devices in shaping users perception of fit between functionalities of their mobile devices and their needs.     

The application of wireless local area network technology to the control of mobile robots

This paper describes a communications and control infrastructure for distributed mobile robotics, which makes use of wireless local area network (WLAN) technology and Internet Protocols (IPs). The use of commercial off-the-shelf (COTS) hardware and software components, and protocols, results in a powerful platform for conducting experiments into collective or co-operative robotics. Standard Transmission Control Protocol/Internet Protocol (TCP/IP) compatible applications programming interfaces (APIs) allow for rapid and straightforward development of applications software. Further, the message bandwidth available from WLAN interfaces (1–2 Mbits/s) facilitates multi-robot experiments requiring high data rates, for instance in robot vision or navigation. The infrastructure described is equally applicable to tele-operated mobile robots.     

基于用户使用移动设备习惯的隐式认证初探

在移动设备(特别是手机)上输入密码是非常麻烦的。随着越来越多的人使用移动设备访问Internet服务,或者从事移动商务活动,人们希望能够简化身份认证操作。为此,提出一种新的身份认证方法——隐式认证,它直接利用用户使用设备的习惯来认证用户,免除了用户输入密码的麻烦;给出了可用于隐式认证的数据及其来源,探讨了可用于隐式认证的具体方法和隐式认证的系统体系结构。所述技术对于隐式认证的进一步研究和应用具有实际意义。     

Point-of-capture archiving and editing of personal experiences from a mobile device

Personal experience computing is an emerging research area in computing support for capturing, archiving, and editing. This paper presents our design, implementation, and evaluation of a mobile authoring tool called mProducer that enables everyday users to effectively and efficiently perform archiving and editing at or immediately after the point-of-capture of digital personal experiences from their camera-equipped mobile devices. This point-of-capture capability is crucial to enable immediate sharing of digital personal experiences anytime, anywhere. For example, we have seen everyday people who used handheld camcorders to capture and report their personal, eye-witnessed experiences during the September 11, 2001 terrorist attack in New York (The September 11 Digital Archive. ). With mProducer, they would be able to perform editing immediately after the point of capture, and then share these newsworthy, time-sensitive digital experiences on the Internet. To address the challenges in both user interface constraints and limited system resources on a mobile device, mProducer provides the following innovative system techniques and UI designs. (1) Keyframe-based editing UI enables everyday users to easily and efficiently edit recorded digital experiences from a mobile device using only key frames with the storyboard metaphor. (2) Storage constrained uploading (SCU) algorithm archives continuous multimedia data by uploading them to remote storage servers at the point of capture, so that it alleviates the problem of limited storage on a mobile device. (3) Sensor-assisted automated editing uses data from a GPS receiver and a tilt sensor attached to a mobile device to facilitate two manual editing steps at the point of capture: removal of blurry frames from hand-induced camera shaking, and content search via location-based content management. We have conducted user studies to evaluate mProducer. Results from the user studies have shown that mProducer scores high in user satisfaction in editing experience, editing quality, task performance time, ease of use, and ease of learning.

Comparison of conventional and soft computing-based power control methods in mobile communications systems

 In this paper, we give a comparison between the conventional power control scheme and soft computing-based approaches in a mobile communications application. At the base station, the `bang–bang' control strategy and a neural network-based prediction control method are employed. In addition, full power command transmission mode, single-bit command transmission mode, and fuzzy logic-based power command enhancement unit are considered. Based on simulation experiments, we quantitatively evaluate the performance of various combinations of these control methods and command transmission modes. Conclusions on the optimal configuration are finally drawn.     

Component-based development of DSP software for mobile communication terminals

DSP software development has been tied down by extreme computational requirements. Furthermore, the DSP development tools available today are less advanced than in other embedded software design. This has lead to DSP software architectures that have not taken into account future expansion needs. Therefore, DSP software architectures have been inherently closed. Now, as system complexity increases, this design methodology becomes more of a burden, since it does not support component-based DSP software development that requires open interfaces.

In this paper, mobile-communications DSP software architectures are studied as cases, and key areas for improvements towards more open DSP software development are identified. Proposed solutions are judged against the limited resources of mobile communication terminals and the characteristics of communication DSPs.     

The impact of avatar realism and anonymity on effective communication via mobile devices

This research investigates the impact on social communication quality of using anonymous avatars during small-screen mobile audio/visual communications. Elements of behavioral and visual realism of avatars are defined, as is an elaborated three-component measure of communication quality called Social Copresence. Experimental results with 196 participants participating in a social interaction using a simulated mobile device with varied levels of avatar visual and behavioral realism showed higher levels of avatar Kinetic Conformity and Fidelity produced increased perceived Social Richness of Medium, while higher avatar Anthropomorphism produced higher levels of Psychological Copresence and Interactant Satisfaction with Communication. Increased levels of avatar Anonymity produced decreases in Social Copresence, but these were smaller when avatars possessed higher levels of visual and behavioral realism.     

Using tracked mobile sensors to make maps of environmental effects

We present the results of a study of environmental carbon monoxide pollution that uses a set of tracked, mobile pollution sensors. The motivating concept is that we will be able to map pollution and other properties of the real world at a fine scale if we can deploy a large set of sensors with members of the general public who would carry them as they go about their normal everyday activities. To prove the viability of this concept we have to demonstrate that data gathered in an ad hoc manner is reliable enough in order to allow us to build interesting geo-temporal maps. We present a trial using a small number of global positioning system-tracked CO sensors. From analysis of raw GPS logs we find some well-known spatial and temporal properties of CO. Further, by processing the GPS logs we can find fine-grained variations in pollution readings such as when crossing roads. We then discuss the space of possibilities that may be enabled by tracking sensors around the urban environment—both in getting at personal experience of properties of the environment and in making summative maps to predict future conditions. Although we present a study of CO, the techniques will be applicable to other environmental properties such as radio signal strength, noise, temperature, humidity and so on.     

A scalable framework for mobile real-time group communication services

A scalable framework for mobile real-time group communication services is developed in this paper. Examples for possible applications of this framework are mobile social networks, mobile conference calls, mobile instant messaging services, and mobile multi-player on-line games. A key requirement for enabling a real-time group communication service is the tight constraint imposed on the call delivery delay. Since establishing such communication service for a group of independent mobile users under a tight delay constraint is NP-hard, a two-tier architecture is proposed, that can meet the delay constraint imposed by the real-time service requirement for many independent mobile clients in a scalable manner. This goal is achieved by two dimensional partition of the space, first by organization and then geographically. Both the time and memory complexity associated with the location management of N mobile users are O(N) for the location management provided by the proposed framework, while a distributed scheme requires O(N²) for both time and memory complexity.     

Modeling and nonlinear computed torque control of ship-mounted mobile satellite communication system

A mobile satellite communication system (MSCS) is a device installed on a moving carrier for mobile satellite communication. It can eliminate disturbance and maintain continuous satellite communication when the carrier is moving. Because of many advantages of mobile satellite communication, the MSCSs are becoming more and more popular in modern mobile communication. In this paper, a typical ship-mounted MSCS is studied. The dynamic model of the system is derived using the generalized Lagrange method both in the joint space and in the workspace. Based on the dynamic model, a nonlinear computed torque controller with trajectory planning is designed to track an aimed satellite with a satisfied transient response. Simulation results in two different situations are presented to show the tracking performance of the controller.     

A self-verification authentication mechanism for mobile satellite communication systems

In order to provide an opportunity to make personal communication as broad as possible, mobile satellite communication systems have recently drawn much attention. However, any communication system raises two major challenging issues: (1) how to determine whether actors are whom they claim to be; and (2) how to protect data against unauthorized disclosure. Although the secret-key cryptosystem (SKC) and the public-key cryptosystem (PKC) have been developed to provide well-defined security services to address these issues each has serous drawbacks while SKC-based authentication schemes have the common demerit that the server which maintains the secret-key table becomes an attractive target for numerous intrusions, PKC-based schemes suffer from the expensive complexity of the public-key infrastructure (PKI) and a high computation overhead. Therefore, in this paper, a self-verification authentication mechanism with lower computation and key management cost is introduced.     

适合于移动多媒体网络的呼叫接纳控制算法

移动多媒体网络应该能够同时支持传统的数据业务和实时交互式多媒体业务,并能够为用户提供QoS保证.在无线移动网中提供QoS保证,呼叫接纳控制扮演着重要的角色.通过对呼叫接纳算法中资源预留方案进行了分析总结,提出了一种适合于移动多媒体网络的自适应呼叫接纳控制算法.     

Optimal switch location in mobile communication networks using hybrid genetic algorithms

The optimal positioning of switches in a mobile communication network is an important task, which can save costs and improve the performance of the network. In this paper we propose a model for establishing which are the best nodes of the network for allocating the available switches, and several hybrid genetic algorithms to solve the problem. The proposed model is based on the so-called capacitated p-median problem, which have been previously tackled in the literature. This problem can be split in two subproblems: the selection of the best set of switches, and a terminal assignment problem to evaluate each selection of switches. The hybrid genetic algorithms for solving the problem are formed by a conventional genetic algorithm, with a restricted search, and several local search heuristics. In this work we also develop novel heuristics for solving the terminal assignment problem in a fast and accurate way. Finally, we show that our novel approaches, hybridized with the genetic algorithm, outperform existing algorithms in the literature for the p-median problem.     

Application of a neuro-fuzzy system to control a mobile vehicle

We describe a fuzzy control based on a neural network, which is obtained by merging the advantages of a neural network, a competitive algorithm, and fuzzy control. This adaptive fuzzy control system can deal with data sampled by a neural network. From such training data, it can produce more reasonable fuzzy rules by a competitive (clustering) algorithm, and finally control the object by the optimized fuzzy rules. This is not a simple combination of the three methods, but a merger into one control system. Some experiments and future considerations are also given.This work was presented in part at the 8th International Symposium on Artificial Life and Robotics, Oita, Japan, January 24–26, 2003     

A hybrid control approach to action coordination for mobile robots

In this paper, the problem concerning how to coordinate the contributions from concurrent controllers, when controlling mobile robots, is investigated. It is shown how a behavior based control system for autonomous robots can be modeled as a hybrid automaton, where each node corresponds to a distinct robot behavior. This type of construction gives rise to chattering executions, but it is shown how regularized automata can be used to solve this problem. As an illustration, the obstacle-negotiation problem is solved by using a combination of a robust path-following behavior and a reactive obstacle-avoidance behavior that move the robot around a given obstacle at a predefined safety distance.     

Using mobile data collectors to improve network lifetime of wireless sensor networks with reliability constraints

In this paper, we focus on maximizing network lifetime of a Wireless Sensor Network (WSN) using mobile Data Collectors (DCs) without compromising on the reliability requirements. We consider a heterogeneous WSN which consists of a large number of sensor nodes, a few DCs, and a static Base Station (BS). The sensor nodes are static and are deployed uniformly in the terrain. The DCs have locomotion capabilities and their movement can be controlled. Each sensor node periodically sends sensed event packets to its nearest DC. The DCs aggregate the event packets received from the sensor nodes and send these aggregate event packets to the static BS. We address the following problem: the DCs should send the aggregate event packets to the BS with a given reliability while avoiding the hotspot regions such that the network lifetime is improved. Reliability is achieved by sending each aggregate event packet via multiple paths to the BS. The network lifetime is maximized by moving the DCs in such a way that the forwarding load is distributed among the sensor nodes. We propose both centralized and distributed approaches for finding a movement strategy of the DCs. We show via simulations that the proposed approaches achieve the required reliability and also maximize the network lifetime compared to the existing approaches.     

Vision-based formation control of mobile robots

1Introduction Formation control of multiple vehicles,such ascooperative control of a group of mobile robots[1~4]and multiple spacecraft[5,6],has beenrecognized as a keytechnologyfor the future and studied by many researchersin recent years.The various control approaches to multiplevehicle formation reported in the literature can becategorized into three groups:leader following schemes;behavior_based methods;and virtual structure techniques.In the leader following approach[1,2,7],one of thevehi…     

Context-aware privacy-preserving access control for mobile computing

In mobile and pervasive computing applications, opportunistic connections allow co-located devices to exchange data directly. Keeping data sharing local enables large-scale cooperative applications and empowers individual users to control what and how information is shared. Supporting such applications requires runtime frameworks that allow them to manage the who, what, when, and how of access to resources. Existing frameworks have limited expressiveness and do not allow data owners to modulate the granularity of information released. In addition, these frameworks focus exclusively on security and privacy concerns of data providers and do not consider the privacy of data consumers. We present PADEC, a context-sensitive, privacy-aware framework that allows users to define rich access control rules over their resources and to attach levels of granularity to each rule. PADEC is also characterized by its expressiveness, allowing users to decide under which conditions should which information be shared. We provide a formal definition of PADEC and an implementation based on private function evaluation. Our evaluation shows that PADEC is more expressive than other mechanisms, protecting privacy of both consumers and providers.     

Vision-based formation control of mobile robots

In this paper,a formatio n control algorithm and an obstacle avoidance control algorithm for mobile robots are developed based on a relative motion sensory system such as a pan/tilt camera vision system,without the need for global sensing and communication between robots.This is achieved by e mploying the velocity variation,instead of actual ve locities,as the control inputs.Simulation and experi mental results have demonstrated the effectiveness of the proposed control methods.     

Robust adaptive control for mobile manipulators

This paper addresses the trajectory tracking control of a nonholonomic wheeled mobile manipulator with parameter uncertainties and disturbances. The proposed algorithm adopts a robust adaptive control strategy where parametric uncertainties are compensated by adaptive update techniques and the disturbances are suppressed. A kinematic controller is first designed to make the robot follow a desired end-effector and platform trajectories in task space coordinates simultaneously. Then, an adaptive control scheme is proposed, which ensures that the trajectories are accurately tracked even in the presence of external disturbances and uncertainties. The system stability and the convergence of tracking errors to zero are rigorously proven using Lyapunov theory. Simulations results are given to illustrate the effectiveness of the proposed robust adaptive control law in comparison with a sliding mode controller.