The Minimum Scheduling Time for Convergecast in Wireless Sensor Networks

We study the scheduling problem for data collection from sensor nodes to the sink node in wireless sensor networks, also referred to as the convergecast problem. The convergecast problem in general network topology has been proven to be NP-hard. In this paper, we propose our heuristic algorithm (finding the minimum scheduling time for convergecast (FMSTC)) for general network topology and evaluate the performance by simulation. The results of the simulation showed that the number of time slots to reach the sink node decreased with an increase in the power. We compared the performance of the proposed algorithm to the optimal time slots in a linear network topology. The proposed algorithm for convergecast in a general network topology has 2.27 times more time slots than that of a linear network topology. To the best of our knowledge, the proposed method is the first attempt to apply the optimal algorithm in a linear network topology to a general network topology

COMPARISON OF SELENIUM BIOACCUMULATION IN THE CLAMS CORBICULA FLUMINEA AND POTAMOCORBULA AMURENSIS: A BIOENERGETIC MODELING APPROACH

rate) were compared between two bivalves, Corbicula fluminea and Potamocorbula amurensis. The effects of salinity and tem-perature on these kinetic parameters for both clam species also were evaluated. The Asiatic clam, C. fluminea, more efficiently assimilated Se associated with algae (66–87%) than Se associated with oxic sediments (20–37%). However, no consistent difference was found between Se assimilation efficiencies from both food types (19–60%) for P. amurensis. The temperature and salinity had a minor influence on the Se assimilation from ingested food. However, the effects of temperature and salinity were more evident in the uptake from dissolved sources. The influx rate of Se(IV) increased by threefold with the increase of temperature from 5 to 218C for C. fluminea. The increase of salinity from 4 to 20 psu decreased the uptake rate constant (ku) of Se in P. amurensis from 0.011 to 0.005 L/g/h, whereas salinity change (0–8 psu) had a negligible effect on the Se influx rate of C. fluminea. The Se influx rate of P. amurensis decreased by half with the 3.5-fold increase in tissue dry weight. The rate constant of loss was greater for P. amurensis (0.029/d at 8 psu) than for C. fluminea (0.014/d at 0 psu and 0.01/d at 8 psu). A bioenergetic model suggests that dietary uptake is the dominant pathway for Se bioaccumulation in the two clams in San Francisco Bay and that interspecies differences in Se bioaccumulation can be explained by differences in food ingestion rates

End-to-End Differentiable Learning to HDR Image Synthesis for Multi-exposure Images

Recently, high dynamic range (HDR) image reconstruction based on the multiple exposure stack from a given single exposure utilizes a deep learning framework to generate high-quality HDR images. These conventional networks focus on the exposure transfer task to reconstruct the multi-exposure stack. Therefore, they often fail to fuse the multi-exposure stack into a perceptually pleasant HDR image as the inversion artifacts occur. We tackle the problem in stack reconstruction-based methods by proposing a novel framework with a fully differentiable high dynamic range imaging (HDRI) process. By explicitly using the loss, which compares the network's output with the ground truth HDR image, our framework enables a neural network that generates the multiple exposure stack for HDRI to train stably. In other words, our differentiable HDR synthesis layer helps the deep neural network to train to create multi-exposure stacks while reflecting the precise correlations between multi-exposure images in the HDRI process. In addition, our network uses the image decomposition and the recursive process to facilitate the exposure transfer task and to adaptively respond to recursion frequency. The experimental results show that the proposed network outperforms the state-of-the-art quantitative and qualitative results in terms of both the exposure transfer tasks and the whole HDRI process

Surgical repair of descending thoracic and thoracoabdominal aortic aneurysm involving the distal arch: Open proximal anastomosis under deep hypothermia versus arch clamping technique

BackgroundSurgical repair of a descending thoracic and thoracoabdominal aortic aneurysm (DTA/TAAA) involving the distal arch is challenging and requires either deep hypothermic circulatory arrest (DHCA) or crossclamping of the distal arch. The aim of this study was to compare these 2 techniques in the treatment of DTA/TAAA involving the distal arch.MethodsFrom 1994 to 2012, 298 patients underwent open repair of DTA/TAAA through a left thoracotomy. One hundred seventy-four patients with distal arch involvement who were suitable for either DHCA (n = 81) or arch clamping (AC; n = 93), were analyzed. In-hospital outcomes were compared using propensity scores and inverse-probability-of-treatment weighting adjustment to reduce treatment selection bias.ResultsEarly mortality was 11.1% in the DHCA group and 8.6% in the AC group (P = .58). Major adverse outcomes included stroke in 16 patients (9.2%), low cardiac output syndrome in 15 (8.6%), paraplegia in 10 (5.7%), and multiorgan failure in 10 (5.7%). After adjustment, patients who underwent DHCA were at similar risk of death (odds ratio [OR], 1.14; P = .80) and permanent neurologic injury (OR, 0.95; P = .92) to those who underwent AC. Although prolonged ventilator support (>24 hours) was more frequent with DHCA than with AC (OR, 2.60; P = .003), DHCA showed a tendency to lower the risk of paraplegia (OR, 0.15; P = .057).ConclusionsCompared with AC, DHCA did not increase postoperative mortality and morbidity, except for prolonged ventilator support. However, DHCA may offer superior spinal cord protection to AC during repair of DTA/TAAA involving the distal arch

Highly circularly polarized white light using a combination of white polymer light-emitting diode and wideband cholesteric liquid crystal reflector

We present a simple and intriguing device that generates highly circularly polarized white light. It comprises white polymer light-emitting diodes (WPLEDs) attached to a wideband cholesteric liquid crystal (CLC) reflector with a wide photonic bandgap (PBG) covering the visible range. The degree of circular polarization realized is very high over the visible range. The wide PBG was realized by introducing a gradient in pitch of the cholesteric helix by controlling the twisting power within the CLC medium. WPLEDs fabricated using a ternary (red, green, and blue) fluorescent polymer blend with the same moiety showed a low turn-on voltage, high brightness, high efficiency, and good color stability.open0

Indentations on Air Plasma Sprayed Thermal Barrier Coatings Prepared by Different Starting Granules

The effect of starting granules on the indentation properties of air plasma sprayed thermal barrier coatings (TBCs) is investigated in this paper. Various kinds of spray-dried granules are prepared from different processing conditions, especially varying solvent and dispersant, showing a deformed hollow-typed and a filled spherical-typed granule. The similar coating thicknesses are prepared by adjusting process parameters during air plasma spray. All XRD peaks in phase analysis are tetragonal and cubic phases without any monoclinic phase after the starting granules were heat-treated. A relatively porous microstructure of the coating layer could be obtained from the monodisperse granules, while a relatively dense microstructure resulted from the hollow-typed granules. The morphology and distribution of the granules crucially affect the microstructure of thermal barrier coatings and thus have influences on indentation properties such as indentation stress-strain curves, contact damage, and hardness. The implication concerning microstructure design of TBCs for gas turbine applications is considered

Interpreting positive signs of the supraspinatus test in screening for torn rotator cuff.

The purpose of this study was to investigate the validity of the supraspinatus test as a screening test for detecting torn rotator cuff and to determine what its valuable positive signs were. Both the empty-can test and full-can test were performed on 200 shoulders diagnosed by magnetic resonance imaging (MRI)-and in some cases, surgical findings-to have full-thickness or partial-thickness torn rotator cuff s, or no tear in the rotator cuff . During the maneuver, the presence of pain or weakness or both pain and weakness were recorded as positive signs, and the distribution of these signs were analyzed according to the degree of tear. The predictive values were calculated in 2 ways by considering (1) only full-thickness tears as tears and (2) both full- and partial-thickness tears as tears. The 2 tests and the 2 ways of considering partial-thickness tears were compared. Pain and weakness were severity-dependent, and the empty-can test had a higher incidence of pain. The sensitivities of the 2 supraspinatus tests in all positive signs were higher when including partial-thickness tears in the tear group ; however, their specificities were higher when excluding partial-thickness tears. Both pain and weakness were interpretive for the supraspinatus test, and both tests were sensitive to full- and partial- thickness tears and specific for full-thickness tears

Resonance of Domain Wall in a Ferromagnetic Nanostrip: Relation Between Distortion and Velocity

The resonance of the magnetic domain wall under the applied field amplifies its velocity compared to the one-dimensional model. To quantify the amplification, we define the distortion variation rate of the domain wall that can represent how fast and severely the wall shape is variated. Introducing that rate gives a way to bring the resonance into the one-dimensional domain wall dynamics model. We obtain the dissipated energy and domain wall velocity amplification by calculating the distortion variation rate. The relationship between velocity and distortion variation rate agrees well with micromagnetic simulation.Comment: 15 pages, 4 figure