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Ad hoc and sensor networks are an important, emerging niche that is poorly supported by existing operating systems. In this paper, we argue that network-wide energy management is a primary concern in ad hoc networks, and that this functionality is best provided by a systems layer. We are currently designing and implementing a distributed, power-aware, adaptive operating system, called MagnetOS, specifically targeting ad hoc and sensor networks. MagnetOS provides a single system image of a unified Java virtual machine across the nodes that comprise an ad hoc network. By automatically and transparently partitioning applications into components and dynamically placing these components on nodes within the ad hoc network, our system reduces energy consumption, avoids hotspots and increases system longevity. We show that a systems approach to automatic object placement in an ad hoc network can increase system longevity by a factor of four to five. * Supported in part by ONR Grant N00014-01-1-0968. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of these organizations or the U.S. Government. MotivationWith the recent proliferation of cheap and increasingly powerful mobile devices and sensors, ad hoc networking has emerged as a significant application domain. Ad hoc applications appear naturally in mobile environments and when fixed networking infrastructure is either unavailable or impractical. Examples of such ad hoc applications include large-scale environmental data-collection using sensor networks, coordinated battlefield or disasterrelief operations involving mobile computers, and ubiquitous computing in interactive, smart environments. Despite the importance of these emerging application domains, developing applications for ad hoc and sensor networks remains difficult and poorly supported by existing operating systems.Two inherent characteristics of the ad hoc computing environment make developing applications for ad hoc networks particularly difficult: ad hoc networks are limited in resources such as battery capacity, and they exhibit frequent and drastic variation in key system metrics, such as bandwidth and connectivity. Form factor limitations in miniaturized devices place tight constraints on the available energy per node [Hill et al. 00]. In addition, the network topology, available power and bandwidth can vary rapidly and through several orders of magnitude [Satyanarayanan 96]. Applications need to adapt, not only to external changes in the resource constrained, frequently varying ad hoc environment, but also to internal changes initiated by the applications themselves. For instance, a sensor application tracking an object that moves over time may need to relocate its event-filtering component closer to the object to reduce network communication. In addition, an application may change its behavior, as in the transition from defensive to offensive mode in a battle...

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With the continued proliferation of smart mobile devices, Quick Response (QR) code has become one of the most-used types of two-dimensional code in the world. Aiming at beautifying the visual-unpleasant appearance of QR codes, existing works have developed a series of techniques. However, these works still leave much to be desired, such as personalization, artistry, and robustness. To address these issues, in this paper, we propose a novel type of aesthetic QR codes, SEE (Stylize aEsthEtic) QR code, and a three-stage approach to automatically produce such robust style-oriented codes. Specifically, in the first stage, we propose a method to generate an optimized baseline aesthetic QR code, which reduces the visual contrast between the noise-like black/white modules and the blended image. In the second stage, to obtain art style QR code, we tailor an appropriate neural style transformation network to endow the baseline aesthetic QR code with artistic elements. In the third stage, we design an error-correction mechanism by balancing two competing terms, visual quality and readability, to ensure the performance robust. Extensive experiments demonstrate that SEE QR code has high quality in terms of both visual appearance and robustness, and also offers a greater variety of personalized choices to users.

To improve the stability of the autonomous vehicle for high speed tracking, a vehicle estimator scheme integrated into a path-tracking system has been proposed in this paper. Vehicle stability is related to road condition (low road adhesion, high road adhesion, and changing road adhesion) and vehicle state, thus a state observer has been preferred in this paper to estimate vehicle state and tire-road friction as a means of judging vehicle stabilization. For the approach to the estimation, an unscented Kalman filter (UKF) employing a three degrees-of-freedom vehicle model combined with a Magic Formula (MF) tire model was designed. As a widely used model control method, the multi-constraints model predictive control (MMPC) was proposed and that was then used to calculate the desired front steering angle for tracking the planned path. The performance of the MMPC controller, with the estimator, was evaluated by the vehicle simulation software CARSIM and Matlab/Simulink. The simulation results show that the designed MMPC controller with the estimator successfully performs path-tracking at high speed for the intelligent vehicle.