Existence of Positive Solutions of Nonlinear Second-Order Periodic Boundary Value Problems

<p>Abstract</p> <p>This paper is devoted to study the existence of periodic solutions of the second-order equation <inline-formula> <graphic file="1687-2770-2010-626054-i1.gif"/></inline-formula>, where <inline-formula> <graphic file="1687-2770-2010-626054-i2.gif"/></inline-formula> is a Carath&#233;odory function, by combining a new expression of Green's function together with Dancer's global bifurcation theorem. Our main results are sharp and improve the main results by Torres (2003).</p

VeLoc: Finding Your Car in Indoor Parking Structures

While WiFi-based indoor localization is attractive, there are many indoor places without WiFi coverage with a strong demand for localization capability. This paper describes a system and associated algorithms to address the indoor vehicle localization problem without the installation of additional infrastructure. In this paper, we propose VeLoc, which utilizes the sensor data of smartphones in the vehicle together with the floor map of the parking structure to track the vehicle in real time. VeLoc simultaneously harnesses constraints imposed by the map and environment sensing. All these cues are codified into a novel augmented particle filtering framework to estimate the position of the vehicle. Experimental results show that VeLoc performs well when even the initial position and the initial heading direction of the vehicle are completely unknown

Smartphone indoor localization by photo-taking of the environment

Existing mainstream indoor localization technologies mainly rely on RF signatures and thus incur significant and recurring labor cost to measure the time-varying signature map. We have proposed a smartphone localization system using the embedded gyroscope for triangulation from nearby physical features (e.g., store logos) recognized from photo-taking. It requires a much reduced and one-time measurement, while incurs uncertain localization errors. In this paper, we propose two methods to systematically address image matching errors that cause unrecognized physical features and large errors in our system. We formulate the optimal benchmark image selection problem and propose a heuristic algorithm that finds the best benchmark images for high matching accuracy. We propose a couple of geographical constraints to further infer unknown physical features based on the observation that the features chosen by the user are close together. Experiments in a 150 ?? 75m shopping mall, 300 ?? 200m train station show that dramatically we cut down both maximum and general localization errors, and achieve 2-8m accuracy at 80-percentile even with only one benchmark image on the phone. ? 2014 IEEE.EI

High Temperature Oxidation Behaviors of BaO/TiO2 Binary Oxide-Enhanced NiAl-Based Composites

High temperature lubricating composites have been widely used in aerospace and other high-tech industries. In the actual application process, high temperature oxidation resistance is a very importance parameter. In this paper, BaO/TiO2-enhanced NiAl-based composites were prepared by vacuum hot-press sintering. The oxidation resistance performance of the composites at 800 °C was investigated. The composites exhibited very good sintered compactness and only a few pores were present. Meanwhile, the composite had excellent oxidation resistance properties due to the formation of a dense Al2O3 layer which could prevent further oxidation of the internal substrate; its oxidation mechanism was mainly decided by the outward diffusion of Al and the inward diffusion of O. The addition of BaO/TiO2 introduced more boundaries and made the Kp value increase from 1.2 × 10−14 g2/cm4 s to 3.3 × 10−14 g2/cm4 s, leading to a slight reduction in the oxidation resistance performance of the composites—although it was still excellent

Long-Term Impact of China’s Returning Farmland to Forest Program on Rural Economic Development

The Returning Farmland to Forest Program (RFFP) is widely known as one of China&rsquo;s largest and most successful payment schemes for ecosystem service projects for the achievement of both environmental and economic sustainability. By sponsoring afforestation activities and compensating farmers for converting cropland to forest, the project was designed to achieve multiple goals. Ecologically, the program aims to expand forest cover and to reduce flood and soil erosion. Economically, it aims to alleviate poverty and improve rural livelihoods. Although the official metrics indicate successful program outcomes in the short term, researchers have reported mixed and controversial results for long-term outcomes. We combined the difference-in-difference (DID) with instrumental variables (IVs) regression to examine the long-term effects of China&rsquo;s RFFP on local economic development. We found that (1) the RFFP has had a remarkably positive impact on local economic growth in the primary sector, but considerably limits the growth of enterprises above a designated size by 16.8%; (2) the RFFP is unable to promote the development of the secondary industry because it cannot effectively promote the transfer of rural laborers to the secondary industry sector; and (3) in addition to increasing the general budgetary expenditure of local finance by 7.50%, this program has significantly reduced local fiscal revenue by 35.50%. We suggest that eco-compensation should consider the performance of the RFFP in its evaluation criteria