A lightweight,self‐adaptive lock gate designation scheme for data collection in long‐thin wireless sensor networks

Constrained by the physical environments, the long‐thin topology has recently been promoted for many practical deployments of wireless sensor networks (WSNs). In general, a long‐thin topology is composed of a number of long branches of sensor nodes, where along a branch each sensor node has only one potential parent node toward the sink node. Although data aggregation may alleviate excessive packet contention, the maximum payload size of a packet and the dynamically changing traffic loads may severely affect the amount of sensor readings that may be collected along a long branch of sensor nodes. In addition, many practical applications of long‐thin WSNs demand the exact sensor readings at each location along the deployment areas for monitoring and analysis purposes, so sensor readings may not be aggregated when they are collected. This paper proposes a lightweight, self‐adaptive scheme that designates multiple collection nodes, termed lock gates, along a long‐thin network to collect sensor readings sent from their respective upstream sensor nodes. The self‐adaptive lock gate designation scheme balances between the responsiveness and the congestion of data collection while mitigating the funneling effect. The scheme also dynamically adapts the designation of lock gates to accommodate the time‐varying sensor reading generation rates of different sensor nodes. A testbed of 100 Jennic sensor nodes is developed to demonstrate the effectiveness of the proposed lock gate designation scheme. Copyright © 2011 John Wiley & Sons, Ltd.     

Glass Additive Influence on the Sintering Behaviors,Magnetic and Electric Properties of Bi–Zn Co‐Doped Co2Y Ferrites

The Bi₂O₃–B₂O₃–ZnO–SiO₂ (BB35SZ) glass effects on the sintering behavior and magnetic properties of Bi–Zn co‐doped Co₂Y ferrites were investigated in developing low‐temperature‐fired ferrites. The results indicate that BB35SZ glass can be used as a sintering aid to reduce the densification temperature of Co₂Y ferrites from 1300°C to 900°C. The 2(Ba_0.9Bi_0.1O)·2(Zn_0.4Co_0.4Cu_0.2O)·6(Fe_1.97Zn_0.03O₃) ferrite with 4 wt% BB35SZ glass can be densified below 900°C, exhibiting an initial permeability of 3.4 and quality factor of 55. This process provides a promising candidate for multilayer chip magnetic devices for microwave applications.     

The phase transformation and crystallization kinetics of (1 − x)Li2O–xNa2O–Al2O3–4SiO2 glasses

The phase transformation and crystallization kinetics of (1 − x)Li₂O–xNa₂O–Al₂O₃–4SiO₂ glasses have been studied by using differential thermal analysis (DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electron diffraction (ED) analysis. The crystallization temperature at the exothermic peak increases from 1171 to 1212 K when the Na₂O content increases from 0 to 0.6 mol. The crystalline phase is composed of spodumene crystallization when the Na₂O content increases from 0 to 0.6 mol. The activation energy of spodumene crystallization decreases from 444.0 ± 22.2 to 284.0 ± 10.8 kJ mol⁻¹ when the Na₂O content increases from 0 to 0.4 mol. Moreover, the activation energy increases from 284.0 ± 10.8 to 446.0 ± 23.2 kJ mol⁻¹ when the Na₂O content increases from 0.4 to 0.6 mol. The crystallization parameters m and n approach 2, indicating that the surface nucleation and two-dimensional growth are dominant in (1 − x)Li₂O–xNa₂O–Al₂O₃–4SiO₂ glasses.     

Efficient algorithms to create and maintain balanced and threaded binary search trees

The algorithm proposed by Chang and lyengar to perfectly balance binary search trees has been modified to not only balance but also thread binary search trees. Threads are constructed in the same sequence as normal pointers during the balancing process. No extra workspace is necessary, and the running time is also linear for the modified algorithm. Such produced tree structure has minimal average path length for fast information retrieval, and threads to facilitate more flexible and efficient traversing schemes. Maintenance and manipulation of the data structure are discussed and relevant algorithms given.     

The mechanism of plantar unloading in total contact casts: implications for design and clinical use

Although the total contact cast (TCC) has been shown to be an extremely effective treatment for the healing of plantar ulcers in diabetic patients, little is known about the biomechanics of its action. In this study, plantar pressure and ground reaction force measurements were obtained from over 750 foot contacts as five subjects with known elevated plantar forefoot pressures walked barefoot, in a padded cast shoe, and a TCC. Peak plantar pressures in the forefoot were markedly reduced in the cast compared with both barefoot and shoe walking (reductions of 75% and 86% respectively, P < 0.05). Peak plantar pressures in the heel were not, however, significantly different between the shoe and the TCC, and the longer duration of heel loading resulted in an impulse that was more than twice as great in the cast compared with the shoe (P < 0.05). An analysis of load distribution indicated that the mechanisms by which the TCC achieves forefoot unloading are (1) transfer of approximately 30% of the load from the leg directly to the cast wall, (2) greater proportionate load sharing by the heel, and (3) removal of a load-bearing surface from the metatarsal heads because of the "cavity" created by the soft foam covering the forefoot. These results point out some of the "essential design features" of the TCC (which are different from what had been previously supposed), support the use of the TCC for healing plantar ulcers in the forefoot, but raise questions about its utility in the healing of plantar ulcers on the heel.     

Radio characteristics evaluation tests of an experimental 3G WCDMA system in Taiwan suburban environments

Abstract

An experimental study on the radio characteristics of a 3G WCDMA system in a Taiwan suburban environment was conducted. This paper presents the results of handover behaviors. The examinations and performance evaluation are based on the measured E_b /I ₀, mobile system transmitting power, bit‐error‐rate and frame‐error‐rate statistic distributions with respect to the time variations, which corresponds to different measurement locations, under individual and independent but appropriate design of experiment procedures. The corresponding radio characteristics are analyzed and evaluated according to the measured data.     

Example‐based Multiple Local Color Transfer by Strokes

This paper investigates a new approach for color transfer. Rather than transferring color from one image to another globally, we propose a system with a stroke‐based user interface to provide a direct indication mechanism. We further present a multiple local color transfer method. Through our system the user can easily enhance a defect (source) photo by referring to some other good quality (target) images by simply drawing some strokes. Then, the system will perform the multiple local color transfer automatically. The system consists of two major steps. First, the user draws some strokes on the source and target images to indicate corresponding regions and also the regions he or she wants to preserve. The regions to be preserved which will be masked out based on an improved graph cuts algorithm. Second, a multiple local color transfer method is presented to transfer the color from the target image(s) to the source image through gradient‐guided pixel‐wise color transfer functions. Finally, the defect (source) image can be enhanced seamlessly by multiple local color transfer based on some good quality (target) examples through an interactive and intuitive stroke‐based user interface.     

Tripartite dynamic competition and equilibrium analysis on global television market

This study intends to investigate the tripartite competition among CRT, LCD and PDP TV by means of the quarterly shipments of 30- to 45-in. TV. The Lotka–Volterra competition diffusion model has been adopted to conduct the empirical analysis with the Lyapunov function to carry out equilibrium and stability. The results indicate that adopting this model can lead to good performance. The price dropping of LCD TV is greater than that of CRT and PDP TV. The severe dropping in the price of LCD TV leads to its higher growth rates. With respect to the equilibrium and stability analysis, PDP and LCD TV will coexist in the TV market and reach a stable equilibrium, while CRT TV will disappear from the 30- to 45 in. TV market.