bluuebunny/crossref_metadata_2025 huggingface dataset:
Burden of emergency conditions and emergency care usage: new estimates from 40 countries
Authors: Chang Cindy Y , Abujaber Samer , Reynolds Teri A , Camargo Carlos A , Obermeyer Ziad
Published: June 2016

Objective

To estimate the global and national burden of emergency conditions, and compare them to emergency care usage rates.

Methods

We coded all 291 Global Burden of Disease 2010 conditions into three categories to estimate emergency burden: conditions that, if not addressed within hours to days of onset, commonly lead to serious disability or death; conditions with common acute decompensations that lead to serious disability or death; and non-emergencies. Emergency care usage rates were obtained from a systematic literature review on emergency care facilities in low-income and middle-income countries (LMICs), supplemented by national health system reports.

Findings

All 15 leading causes of death and disability-adjusted life years (DALYs) globally were conditions with potential emergent manifestations. We identified 41 facility-based reports in 23 countries, 12 of which were in LMICs; data for 17 additional countries were obtained from national or regional reports on emergency usage. Burden of emergency conditions was the highest in low-income countries, with median DALYs of 47 728 per 100 000 population (IQR 45 253–50 085) in low-income, 25 186 (IQR 21 982–40 480) in middle-income and 15 691 (IQR 14 649–16 382) in high-income countries. Patterns were similar using deaths to measure burden and excluding acute decompensations from the definition of emergency conditions. Conversely, emergency usage rates were the lowest in low-income countries, with median 8 visits per 1000 population (IQR 6–10), 78 (IQR 25–197) in middle-income and 264 (IQR 177–341) in high-income countries.

Conclusions

Despite higher burden of emergency conditions, emergency usage rates are substantially lower in LMICs, likely due to limited access to emergency care.
Modelling the spatial distribution of permafrost in Labrador–Ungava using the temperature at the top of permafrost
Authors: Way Robert G. , Lewkowicz Antoni G.
Published: June 2016

Permafrost zonation in Labrador–Ungava ranges from very isolated patches through to continuous permafrost. Here we present a new estimate of the distribution of permafrost at high resolution (250 m × 250 m) using spatial numerical modelling supported by station data from 29 air and ground climate monitoring stations. Permafrost presence was estimated using a modified version of the temperature at the top of permafrost (TTOP) model. Mean ground surface temperatures were modelled using gridded air temperatures and a novel n-factor parameterization scheme that compensates for regional differences in continentality, snowfall, and land cover and is transferable to other Subarctic environments. The thermal offset was modelled using land cover and surficial material datasets. Predicted TTOP values for the average climate range regionally from −9 °C (for high elevations in northern Quebec) to +5 °C (for southeastern Labrador – Quebec). Modelling for specific temporal windows (1948–1962, 1982–1996, 2000–2014) suggests that permafrost area increased from the middle of the 20th century to a potential peak extent (36% of the total land area) in the 1990s. Subsequent warming is predicted to have caused a decrease in permafrost extent of one-quarter (95 000 km2), even if air temperatures rise no further, providing air and ground temperatures equilibrate. Zonal boundaries derived by upscaling the high-resolution model are highly scale dependent, precluding direct comparison with the Permafrost Map of Canada that was generated without the use of geographic information system based analyses.
Taylor’s power law and fixed-precision sampling: application to abundance of fish sampled by gillnets in an African lake
Authors: Xu Meng , Kolding Jeppe , Cohen Joel E.
Published: June 2016

Taylor’s power law (TPL) describes the variance of population abundance as a power-law function of the mean abundance for a single or a group of species. Using consistently sampled long-term (1958–2001) multimesh capture data of Lake Kariba in Africa, we showed that TPL robustly described the relationship between the temporal mean and the temporal variance of the captured fish assemblage abundance (regardless of species), separately when abundance was measured by numbers of individuals and by aggregate weight. The strong correlation between the mean of abundance and the variance of abundance was not altered after adding other abiotic or biotic variables into the TPL model. We analytically connected the parameters of TPL when abundance was measured separately by the aggregate weight and by the aggregate number, using a weight–number scaling relationship. We utilized TPL to find the number of samples required for fixed-precision sampling and compared the number of samples when sampling was performed with a single gillnet mesh size and with multiple mesh sizes. These results facilitate optimizing the sampling design to estimate fish assemblage abundance with specified precision, as needed in stock management and conservation.
Sufentanil attenuates impairment of the endothelium-dependent vasodilation induced by hypoxia–reoxygenation in the rat coronary artery
Authors: Cheng Xin-qi , Zhang Jun-yan , Gao Shan-shan , Wu Hao , Zuo You-mei , Gu Er-wei , Chen Zhi-wu
Published: June 2016

Sufentanil has been used broadly in cardiac surgery, but the mechanisms by which it modulates coronary vascular tone after ischemia–reperfusion injury are largely unknown. Effects of sufentanil on coronary tone and on the relaxation of rat coronary arteries (CAs) in response to endothelium-dependent (acetylcholine) and endothelium-independent (sodium nitroprusside) relaxing agents in the presence of hypoxia–reoxygenation (H/R) was studied in an in vitro organ chamber setup. Sufentanil (10−7–10−4 mol/L) relaxed rat CA rings in endothelium-dependent and endothelium-independent manners. In endothelium-intact rings, preincubation of H/R-treated CAs with sufentanil (10−5 mol/L) significantly increased the acetylcholine response, but did not augment sodium nitroprusside-induced relaxation. Sufentanil-mediated potentiation of acetylcholine-induced relaxation was not affected by a nitric oxide synthase inhibitor or by intermediate- or small-conductance Ca2+-activated K+ channel blockers. However, potentiation was abolished by iberiotoxin (100 nmol/L), a selective inhibitor of large-conductance Ca2+-activated K+ channels, as well as Rp-cAMPS (30 μmol/L), a cyclic AMP-dependent protein kinase (PKA) inhibitor. Sufentanil induced endothelium-dependent and endothelium-independent relaxation and attenuated H/R-induced impairment of endothelium-dependent vasodilation in the rat CAs. The potentiating effect of sufentanil may involve activation of large-conductance Ca2+-activated K+ channels via cAMP-dependent mechanisms.
Spectrum of area in the Faddeev formulation of gravity
Authors: Khatsymovsky V. M.
Published: June 2016

Faddeev formulation of general relativity (GR) is considered where the metric is composed of ten vector fields or a ten-dimensional tetrad. Upon partial use of the field equations, this theory results in the usual general relativity (GR).

Earlier, we have proposed first-order representation of the minisuperspace model for the Faddeev formulation where the tetrad fields are piecewise constant on the polytopes like four-simplices or, say, cuboids into which [Formula: see text] can be decomposed, an analogue of the Cartan–Weyl connection-type form of the Hilbert–Einstein action in the usual continuum GR.

In the Hamiltonian formalism, the tetrad bilinears are canonically conjugate to the orthogonal connection matrices. We evaluate the spectrum of the elementary areas, functions of the tetrad bilinears. The spectrum is discrete and proportional to the Faddeev analog [Formula: see text] of the Barbero–Immirzi parameter [Formula: see text]. The possibility of the tetrad and metric discontinuities in the Faddeev gravity allows to consider any surface as consisting of a set of virtually independent elementary areas and its spectrum being the sum of the elementary spectra. Requiring consistency of the black hole entropy calculations known in the literature we are able to estimate [Formula: see text].
N-methylated 25-oxasmaragdyrins: Synthesis, structure and properties
Authors: Kaur Tejinder , Lee Way-Zen , Ravikanth Mangalampalli
Published: June 2016

The [Formula: see text]-methylated 25-oxasmaragdyrins were synthesized by reacting 25-oxasmaragdyrins with CH3I in presence of KOH in THF at reflux temperature. Although the reactions were carried out in presence of excess CH3I, we obtained only dimethyl-25-oxasma ragdyrins, where [Formula: see text]-methylations occurred at 24 and 26 “N”s of pyrrole rings of tripyrrane moiety of smaragdyrin core as confirmed by X-ray crystallography. The [Formula: see text]-methylated-25-oxasmaragdyrins were characterized in detail by 1D and 2D NMR spectroscopy, absorption, fluorescence and electrochemical techniques. The effect of distortion induced by methylation, clearly reflected in structural and electronic properties of the macrocycle. All the pyrrole and furan protons experienced upfield shifts in the 1H NMR and maximum upfield shifts were noted for the [Formula: see text]-methylated pyrrole ring protons. The absorption spectra showed broad Soret band and four ill-defined Q-bands with significant reduction in extinction coefficients. The [Formula: see text]-methylated 25-oxasmaragdyrins were comparatively less fluorescent. The redox studies indicated that they are difficult to oxidize and easier to reduce.
NUMERICAL STUDY OF CONTROL OF FLOW SEPARATION OVER A RAMP WITH NANOSECOND PLASMA ACTUATOR
Authors: ZHENG J. G. , KHOO B. C. , CUI Y. D. , ZHAO Z. J. , LI J.
Published: June 2016

The nanosecond plasma discharge actuator driven by high voltage pulse with typical rise and decay time of several to tens of nanoseconds is emerging as a promising active flow control means in recent years and is being studied intensively. The characterization study reveals that the discharge induced shock wave propagates through ambient air and introduces highly transient perturbation to the flow. On the other hand, the residual heat remaining in the discharge volume may trigger the instability of external flow. In this study, this type of actuator is used to suppress flow separation over a ramp model. Numerical simulation is carried out to investigate the interaction of the discharge induced disturbance with the external flow. It is found that the flow separation region over the ramp can be reduced significantly. Our work may provide some insights into the understanding of the control mechanism of nanosecond pulse actuator.
EVALUATION OF THE PERFORMANCE OF THE HYBRID LATTICE BOLTZMANN BASED NUMERICAL FLUX
Authors: ZHENG H. W. , SHU C.
Published: June 2016

It is well known that the numerical scheme is a key factor to the stability and accuracy of a Navier-Stokes solver. Recently, a new hybrid lattice Boltzmann numerical flux (HLBFS) is developed by Shu's group. It combines two different LBFS schemes by a switch function. It solves the Boltzmann equation instead of the Euler equation. In this article, the main object is to evaluate the ability of this HLBFS scheme by our in-house cell centered hybrid mesh based Navier-Stokes code. Its performance is examined by several widely-used bench-mark test cases. The comparisons on results between calculation and experiment are conducted. They show that the scheme can capture the shock wave as well as the resolving of boundary layer.
CHARACTERISTICS OF THE JET IMPACT DURING THE INTERACTION BETWEEN A BUBBLE AND A WALL
Authors: LI SHUAI , WANG SHI-PING , ZHANG A-MAN
Published: June 2016

The dynamics of a toroidal bubble splitting near a rigid wall in an inviscid incompressible fluid is studied in this paper. The boundary integral method is adopted to simulate the bubble motion. After the jet impact, the vortex ring model is used to handle the discontinued potential of the toroidal bubble. When the toroidal bubble is splitting, topology changes are made tear the bubble apart. Then, the vortex ring model is extended to multiple vortex rings to simulate the interaction between two toroidal bubbles. A typical case is discussed in this study. Besides, the velocity fields and pressure contours surrounding the bubble are used to illustrate the numerical results. An annular high pressure region is generated at the splitting location, and the maximum pressure may be much higher than the jet impact. More splits may happen after the first split.
AN IMPROVED MOMENTUM-EXCHANGED IMMERSED BOUNDARY-BASED LATTICE BOLTZMANN METHOD FOR INCOMPRESSIBLE VISCOUS THERMAL FLOWS
Authors: CHEN MUFENG , NIU XIAODONG
Published: June 2016

An improved momentum-exchanged immersed boundary-based lattice Boltzmann method (MEIB-LBM) for incompressible viscous thermal flows is presented here. MEIB-LBM was first proposed by Niu et al, which has been shown later that the non-slip boundary condition is not satisfied. Wang. et al. and Hu. et al overcome this drawback by iterative method. But it needs to give an appropriate relaxation parameter. In this work, we come back to the intrinsic feature of LBM, which uses the density distribution function as a dependent variable to evolve the flow field, and uses the density distribution function correction at the neighboring Euler mesh points to satisfy the non-slip boundary condition on the immersed boundary. The same idea can also be applied to the thermal flows with fluid-structure interference. The merits of present improvements for the original MEIB-LBM are that the intrinsic feature of LBM is kept and the flow penetration across the immersed boundaries is avoided. To validate the present method, examples, including forced convection over a stationary heated circular cylinder for heat flux condition, and natural convection with a suspended circle particle in viscous fluid, are simulated. The streamlines, isothermal contours, the drag coefficients and Nusselt numbers are calculated and compared to the benchmark results to demonstrate the effective of the present method.
NUMERICAL INVESTIGATIONS OF TWO TYPICAL UNSTEADY FLOWS IN TURBOMACHINERY USING THE MULTI-PASSAGE MODEL
Authors: ZHOU DI , LU ZHILIANG , GUO TONGQING , SHEN ENNAN
Published: June 2016

In this paper, the research on two types of unsteady flow problems in turbomachinery including blade flutter and rotor-stator interaction is made by means of numerical simulation. For the former, the energy method is often used to predict the aeroelastic stability by calculating the aerodynamic work per vibration cycle. The inter-blade phase angle (IBPA) is an important parameter in computation and may have significant effects on aeroelastic behavior. For the latter, the numbers of blades in each row are usually not equal and the unsteady rotor-stator interactions could be strong. An effective way to perform multi-row calculations is the domain scaling method (DSM). These two cases share a common point that the computational domain has to be extended to multi passages (MP) considering their respective features. The present work is aimed at modeling these two issues with the developed MP model. Computational fluid dynamics (CFD) technique is applied to resolve the unsteady Reynolds-averaged Navier-Stokes (RANS) equations and simulate the flow fields. With the parallel technique, the additional time cost due to modeling more passages can be largely decreased. Results are presented on two test cases including a vibrating rotor blade and a turbine stage.
GPU IMPLEMENTATION OF PRECONDITIONING METHOD FOR LOW-SPEED FLOWS
Authors: ZHANG JIALE , CHEN HONGQUAN
Published: June 2016

An improved preconditioning method for low-Mach-number flows is implemented on a GPU platform. The improved preconditioning method employs the fluctuation of the fluid variables to weaken the influence of accuracy caused by the truncation error. The GPU parallel computing platform is implemented to accelerate the calculations. Both details concerning the improved preconditioning method and the GPU implementation technology are described in this paper. Then a set of typical low-speed flow cases are simulated for both validation and performance analysis of the resulting GPU solver. Numerical results show that dozens of times speedup relative to a serial CPU implementation can be achieved using a single GPU desktop platform, which demonstrates that the GPU desktop can serve as a cost-effective parallel computing platform to accelerate CFD simulations for low-Speed flows substantially.
SPATIALLY-AVERAGED DIFFUSIVITIES FOR POLLUTANT TRANSPORT IN VEGETATED FLOWS
Authors: HUANG JUN , ZHANG XIAOFENG , CHUA VIVIEN P.
Published: June 2016

Vegetation in wetlands can create complicated flow patterns and may provide many environmental benefits including water purification, flood protection and shoreline stabilization. The interaction between vegetation and flow has significant impacts on the transport of pollutants, nutrients and sediments. In this paper, we investigate pollutant transport in vegetated flows using the Delft3D-FLOW hydrodynamic software. The model simulates the transport of pollutants with the continuous release of a passive tracer at mid-depth and mid-width in the region where the flow is fully developed. The theoretical Gaussian plume profile is fitted to experimental data, and the lateral and vertical diffusivities are computed using the least squares method. In previous tracer studies conducted in the laboratory, the measurements were obtained at a single cross-section as experimental data is typically collected at one location. These diffusivities are then used to represent spatially-averaged values. With the numerical model, sensitivity analysis of lateral and vertical diffusivities along the longitudinal direction was performed at 8 cross-sections. Our results show that the lateral and vertical diffusivities increase with longitudinal distance from the injection point, due to the larger size of the dye cloud further downstream. A new method is proposed to compute diffusivities using a global minimum least squares method, which provides a more reliable estimate than the values obtained using the conventional method.
WAKE NUMERICAL SIMULATION BASED ON THE PARK-GAUSS MODEL AND CONSIDERING ATMOSPHERIC STABILITY
Authors: YANG XIANGSHENG , ZHAO NING , TIAN LINLIN , ZHU JUN
Published: June 2016

In this paper, a new Park-Gauss model based on the assumption of the Park model and the Eddy-viscosity model is investigated to conduct the wake numerical simulation for solving a single wind turbine problem. The initial wake radius has been modified to improve the model’s numerical accuracy. Then the impact of the atmospheric stability based on the Park-Gauss model has been studied in the wake region. By the comparisons and the analyses of the test results, it turns out that the new Park-Gauss model could achieve better effects of the wind velocity simulation in the wake region. The wind velocity in the wake region recovers quickly under the unstable atmospheric condition provided the wind velocity is closest to the test result, and recovers slowly under stable atmospheric condition in case of the wind velocity is lower than the test result. Meanwhile, the wind velocity recovery falls in between the unstable and stable neutral atmospheric conditions.
DESIGN AND ANALYSIS OF AN STATIC AEROELASTIC EXPERIMENT
Authors: HOU YING-YU , YUAN KAI-HUA , LV JI-NAN , LIU ZI-QIANG
Published: June 2016

Static aeroelastic experiments are very common in the United States and Russia. The objective of static aeroelastic experiments is to investigate deformation and loads of elastic structure in flow field. Generally speaking, prerequisite of this experiment is that the stiffness distribution of structure is known. This paper describes a method for designing experimental models, in the case where the stiffness distribution and boundary condition of a real aircraft are both uncertain. The stiffness distribution form of the structure can be calculated via finite element modeling and simulation calculation and F141 steels and rigid foam are used to make elastic model. In this paper, the design and manufacturing process of static aeroelastic models is presented and a set of experiment model was designed to simulate the stiffness of the designed wings, a set of experiments was designed to check the results. The test results show that the experimental method can effectively complete the design work of elastic model. This paper introduces the whole process of the static aeroelastic experiment, and the experimental results are analyzed. This paper developed a static aeroelasticity experiment technique and established an experiment model targeting at the swept wing of a certain kind of large aspect ratio aircraft.
WAVE-GENERATED FLOWS ON THE WATER SURFACE
Authors: SHATS MICHAEL , PUNZMANN HORST , FRANCOIS NICOLAS , XIA HUA
Published: June 2016

Predicting trajectories of fluid parcels on the water surface perturbed by waves is a difficult mathematical and theoretical problem. It is even harder to model flows generated on the water surface due to complex three-dimensional wave fields, which commonly result from the modulation instability of planar waves. We have recently shown that quasi-standing, or Faraday, waves are capable of generating horizontal fluid motions on the water surface whose statistical properties are very close to those in two-dimensional turbulence. This occurs due to the generation of horizontal vortices. Here we show that progressing waves generated by a localized source are also capable of creating horizontal vortices. The interaction between such vortices can be controlled and used to create stationary surface flows of desired topology. These results offer new methods of surface flow generation, which allow engineering inward and outward surface jets, large-scale vortices and other complex flows. The new principles can be also be used to manipulate floaters on the water surface and to form well-controlled Lagrangian coherent structures on the surface. The resulting flows are localized in a narrow layer near the surface, whose thickness is less than one wavelength.
COST-EFFECTIVE FABRICATION OF WETTABILITY GRADIENT COPPER SURFACE BY SCREEN PRINTING AND ITS APPLICATION TO CONDENSATION HEAT TRANSFER
Authors: LEU TZONG-SHYNG , HUANG HUNG-MING , HUANG DING-JUN
Published: June 2016

In this paper, wettability gradient pattern is applied to condensation heat transfer on a copper tube surface. For this application, the vital issue is how to fabricate gradient patterns on a curve tube surface to accelerate the droplet collection efficiently. For this purpose, novel fabrication processes are developed to form wettability gradient patterns on a curve copper tube surface by using roller screen printing surface modification techniques. The roller screen printing surface modification techniques can easily realize wettability gradient surfaces with superhydrophobicity and superhydrophilicity on a copper tube surface. Experimental results show the droplet nucleation sites, movement and coalescence toward the collection areas can be effectively controlled which can assist in removing the condensation water from the surface. The effectiveness of droplet collection is appropriate for being applied to condensation heat transfer in the foreseeable future.
THE BRIEF INTRODUCTION OF DIFFERENT LASER DIAGNOSTICS METHODS USED IN AERO-ENGINE COMBUSTION RESEARCH
Authors: XING FEI , SONG GE , RUAN CAN , ZHAO JIAN , YANG YONGJUN
Published: June 2016

Combustion test diagnose has always been one of the most important technologies for the development of aerospace engineering. Laser diagnostics techniques developed quickly in the past several years. They are used to measure the parameters of the combustion flow field such as velocity, temperature, components concentration with high space and time resolution and brought no disturbance. Planar Laser-Induced Fluorescence, Coherent Anti-Stokes Raman Scattering, Tunable Diode Laser Absorption Spectroscopy and Raman Scattering were introduced systemically in this paper. After analysis their own advantages and disadvantages, it is believed that Raman Scattering system is more suitable for research activities on aero-engine combustion systems.
SIMULTANEOUS OBSERVATION OF ENERGY AND ENSTROPHY CASCADES IN THIN-LAYER TURBULENCE
Authors: XIA HUA , FRANCOIS NICOLAS , PUNZMANN HORST , BYRNE DAVID , SHATS MICHAEL
Published: June 2016

We report the simultaneous observation of the inverse energy and direct enstrophy cascade in thin-layer turbulence. The experiments are conducted in an electromagnetically driven flow with layers of stratified fluid. Recent questions regarding the two-dimensionality of electromagnetically driven turbulence in such experiments are addressed.
Integrating microsecond circuit switching into the data center
Authors: Porter George , Strong Richard , Farrington Nathan , Forencich Alex , Chen-Sun Pang , Rosing Tajana , Fainman Yeshaiahu , Papen George , Vahdat Amin
Published: June 2016

Recent proposals have employed optical circuit switching (OCS) to reduce the cost of data center networks. However, the relatively slow switching times (10--100 ms) assumed by these approaches, and the accompanying latencies of their control planes, has limited its use to only the largest data center networks with highly aggregated and constrained workloads. As faster switch technologies become available, designing a control plane capable of supporting them becomes a key challenge.

In this paper, we design and implement an OCS prototype capable of switching in 11.5 us, and we use this prototype to expose a set of challenges that arise when supporting switching at microsecond time scales. In response, we propose a microsecond-latency control plane based on a circuit scheduling approach we call Traffic Matrix Scheduling (TMS) that proactively communicates circuit assignments to communicating entities so that circuit bandwidth can be used efficiently.
Expressive privacy control with pseudonyms
Authors: Han Seungyeop , Liu Vincent , Pu Qifan , Peter Simon , Anderson Thomas , Krishnamurthy Arvind , Wetherall David
Published: June 2016

As personal information increases in value, the incentives for remote services to collect as much of it as possible increase as well. In the current Internet, the default assumption is that all behavior can be correlated using a variety of identifying information, not the least of which is a user's IP address. Tools like Tor, Privoxy, and even NATs, are located at the opposite end of the spectrum and prevent any behavior from being linked. Instead, our goal is to provide users with more control over linkability---which activites of the user can be correlated at the remote services---not necessarily more anonymity.

We design a cross-layer architecture that provides users with a
pseudonym
abstraction. To the user, a pseudonym represents a set of activities that the user is fine with linking, and to the outside world, a pseudonym gives the illusion of a single machine. We provide this abstraction by associating each pseudonym with a unique, random address drawn from the IPv6 address space, which is large enough to provide each device with multiple globally-routable addresses. We have implemented and evaluated a prototype that is able to provide unlinkable pseudonyms within the Chrome web browser in order to demonstrate the feasibility, efficacy, and expressiveness of our approach.
Bringing cross-layer MIMO to today's wireless LANs
Authors: Kumar Swarun , Cifuentes Diego , Gollakota Shyamnath , Katabi Dina
Published: June 2016

Recent years have seen major innovations in cross-layer wireless designs. Despite demonstrating significant throughput gains, hardly any of these technologies have made it into real networks. Deploying cross-layer innovations requires adoption from Wi-Fi chip manufacturers. Yet, manufacturers hesitate to undertake major investments without a better understanding of how these designs interact with real networks and applications.

This paper presents the first step towards breaking this stalemate, by enabling the adoption of cross-layer designs in today's networks with commodity Wi-Fi cards and actual applications. We present OpenRF, a cross-layer architecture for managing MIMO signal processing. OpenRF enables access points on the same channel to cancel their interference at each other's clients, while beamforming their signal to their own clients. OpenRF is self-configuring, so that network administrators need not understand MIMO or physical layer techniques.

We patch the iwlwifi driver to support OpenRF on off-the-shelf Intel cards. We deploy OpenRF on a 20-node network, showing how it manages the complex interaction of cross-layer design with a real network stack, TCP, bursty traffic, and real applications. Our results demonstrate an average gain of 1.6x for TCP traffic and a significant reduction in response time for real-time applications, like remote desktop.
See through walls with WiFi!
Authors: Adib Fadel , Katabi Dina
Published: June 2016

Wi-Fi signals are typically information carriers between a transmitter and a receiver. In this paper, we show that Wi-Fi can also extend our senses, enabling us to see moving objects through walls and behind closed doors. In particular, we can use such signals to identify the number of people in a closed room and their relative locations. We can also identify simple gestures made behind a wall, and combine a sequence of gestures to communicate messages to a wireless receiver without carrying any transmitting device. The paper introduces two main innovations. First, it shows how one can use MIMO interference nulling to eliminate reflections off static objects and focus the receiver on a moving target. Second, it shows how one can track a human by treating the motion of a human body as an antenna array and tracking the resulting RF beam. We demonstrate the validity of our design by building it into USRP software radios and testing it in office buildings.
Empowering the creative user
Authors: Krishnamoorthi Vengatanathan , Bergström Patrik , Carlsson Niklas , Eager Derek , Mahanti Anirban , Shahmehri Nahid
Published: June 2016

This paper presents the design, implementation, and validation of a novel system that supports streaming and playout of personalized, multi-path, nonlinear video. In contrast to regular video, in which the file content is played sequentially, our design allows multiple nonlinear video sequences of the underlying (linear) video to be stitched together and played in any personalized order, and clients can be provided multiple path choices. The design combines the ideas of HTTP-based adaptive streaming (HAS) and multi-path nonlinear video. Personalization of the content is achieved with the use of a customized metafile, which is downloaded separately from the underlying media and the manifest file that defines the HAS structure. An extension to the user interface allows path choices to be presented to and made by the user. Novel buffer management and prefetching policies are used to ensure seamless uninterrupted playback regardless of client path choices, even under scenarios in which clients defer their choices until the last possible moment. Our solution allows creative home users to easily create their own multi-path nonlinear video, opening the door to an endless possibility of new opportunities and media forms.
Smart in-network deduplication for storage-aware SDN
Authors: Hua Yu , Liu Xue , Feng Dan
Published: June 2016

In order to efficiently handle the rapid growth of data and reduce the overhead of network transmission, we propose an in-network deduplication for storage-aware Software Defined Network (SDN), called SMIND. Unlike conventional source or destination deduplication schemes, SMIND implements in-network deduplication via SDN. Moreover, to address the performance bottleneck of accessing and indexing SDN controller, we implement an SDN-enabled Flash Translation Layer (FTL) in a real prototype of Solid State Disk (SSD). Experimental results demonstrate the efficiency and efficacy of SMIND.
A software defined approach to unified IPv6 transition
Authors: Xia Wenfeng , Tsou Tina , Lopez Diego R. , Sun Qiong , Lu Felix , Xie Haiyong
Published: June 2016

The IPv6 transition has been an ongoing process throughout the world due to the exhaustion of the IPv4 address space. However, this transition leads to costly end-to-end network upgrades and poses new challenges of managing a large number of devices with a variety of transitioning protocols. Recognizing these difficulties, we propose an software defined approach to unifying the deployment of IPv6 in a cost-effective, flexible manner. Our deployment and experiments demonstrate significant benefits of this approach, including low complexity, low cost and high flexibility of adopting different existing transition mechanisms.
Don't drop, detour!
Authors: Calder Matt , Miao Rui , Zarifis Kyriakos , Katz-Bassett Ethan , Yu Minlan , Padhye Jitendra
Published: June 2016

Today's data centers must support a range of workloads with different demands. While existing approaches handle routine traffic smoothly, ephemeral but intense hotspots cause excessive packet loss and severely degrade performance. This loss occurs even though the congestion is typically highly localized, with spare buffer capacity available at nearby switches.

We argue that switches should share buffer capacity to effectively handle this spot congestion without the latency or monetary hit of deploying large buffers at individual switches. We present detour-induced buffer sharing (DIBS), a mechanism that achieves a near lossless network without requiring additional buffers. Using DIBS, a congested switch detours packets randomly to neighboring switches to avoid dropping the packets. We implement DIBS in hardware, on software routers in a testbed, and in simulation, and we demonstrate that it reduces the 99th percentile of query completion time by 85%, with very little impact on background traffic.
R2D2
Authors: Grosvenor Matthew P. , Schwarzkopf Malte , Moore Andrew W.
Published: June 2016

Modern data centers commonly run distributed applications that require low-latency communication, and whose performance is critical to service revenue. If as little as one machine in 10,000 is a latency outlier, around 18% of requests will experience high latency. The sacrifice of latency determinism for bandwidth, however, is not an inevitable one. In our R2D2 architecture, we conceptually split the data centre network into an unbuffered, unswitched low-latency network (LLNet) and a deeply buffered bandwidth centric network (BBNet). Through explicitly scheduling network multiplexing in software, our prototype implementation achieves 99.995% and 99.999% messaging latencies of 35us and 75us respectively for 1514-byte packets on a fully loaded network. Furthermore, we show that it is possible to merge the conceptually separate LLNet and BBNet networks onto the same physical infrastructure using commodity switched Ethernet hardware.
Interest set mechanism to improve the transport of named data networking
Authors: Jiang Xiaoke , Bi Jun
Published: June 2016

In this paper, we proposal an Interest Set mechanism which aggregate similar Interest packets from same flow to one packet to improve the efficient of transport of NDN. The trick here is to reset lifetime of corresponding PIT entry in the immediate routers every time when valid Data packet is passed by. This mechanism covers the time and space uncertainty of data generating, reduce the cost of maintaining the pipeline and improve the transport of NDN.
Greedy forwarding for mobile social networks embedded in hyperbolic spaces
Authors: Zhang Jingwei
Published: June 2016

In this work, we design and evaluate a novel greedy forwarding algorithm using metrics in hyperbolic spaces. Hyperbolic geometry has a natural topological reflection of scale-free networks, and greedy algorithm failed in Euclidean space becomes possible in hyperbolic one. We show that mobile social networks can be successfully embedded in such spaces, and obtains competitive performance in terms of message delivery ratio and cost. Under this result, we thus intuitively reveal the fundamental reason that why the famous BUBBLE Rap achieves the optimal performance.
Location Estimation Using Crowdsourced Spatial Relations
Authors: Skoumas Georgios , Pfoser Dieter , Kyrillidis Anastasios , Sellis Timos
Published: June 2016

The “crowd” has become a very important geospatial data provider. Specifically, nonexpert users have been providing a wealth of quantitative geospatial data (e.g., geotagged tweets or photos, online). With spatial reasoning being a basic form of human cognition, textual narratives expressing user travel experiences (e.g., travel blogs) would provide an even bigger source of geospatial data. Narratives typically contain qualitative geospatial data in the form of objects and spatial relations (e.g., “St. John’s church is to the
North of
the Acropolis museum.” The scope of this work is (i) to extract these spatial relations from textual narratives, (ii) to quantify (model) them, and (iii) to reason about object locations based only on the quantified spatial relations. We use information extraction methods to identify toponyms and spatial relations, and we formulate a quantitative approach based on distance and orientation features to represent the latter. Probability density functions (PDFs) for spatial relations are determined by means of a greedy expectation maximization (EM)-based algorithm. These PDFs are then used to estimate unknown object locations. Experiments using a text corpus harvested from travel blog sites establish the considerable location estimation accuracy of the proposed approach on synthetic and real-world scenarios.
ACM IUI 2016 conference highlights
Authors: Nichols Jeffrey , O'Donovan John , Mahmud Jalal
Published: June 2016

As co-chairs of the 21st ACM International Conference on Intelligent User Interfaces (ACM IUI 2016), we are pleased to share with the SIGAI community our thoughts and experiences with this year's edition of the conference. This year's conference was held in Sonoma, California, USA (http://iui.acm.org/2016/), a short drive to the north of San Francisco in the heart of California's wine production region.
Multiscale modeling approach for hierarchical aligned aggregated small area health data
Authors: Aregay Mehreteab , Lawson Andrew B. , Faes Christel , Kirby Russell S. , Carroll Rachel , Watjou Kevin
Published: June 2016

When data are aggregated from a finer to a coarser geographical level, there will be loss of information known as the scaling problem in geography. To address the scaling problem, we propose to use a joint convolution model that describes the risk variation at both the finer and coarser levels simultaneously by sharing both the correlated and the uncorrelated components. We compare our model with the naive approach that ignores the scale effect in real and simulated data in a range of criteria such as deviance information criterion (DIC), Watanabe-Akaike information criterion, and mean square prediction error (MSPE). We found that our multiscale model is better than the naive model.
Report from industrial workshop: ACM SIGSPATIAL 2015 Industrial Workshop Seattle, Washington, USA - November 2, 2015
Authors: Tanin Egemen , Trajcevski Goce
Published: June 2016

The industrial workshop at ACM SIGSPATIAL 2015 (http://cwds.uw.edu/sigspatial workshop) aimed at gathering developers and researchers from leading companies producing well-established systems in areas related to SIGSPATIAL. The workshop was organized in two parts.
MobiGIS 2015 workshop report: the 4th ACM SIGSPATIAL International Workshop on Mobile Geographic Information Systems Seattle, Washington, USA - November 3, 2015
Authors: Chow Chi-Yin , Damiani Maria Luisa , Shekhar Shashi
Published: June 2016

Combining the functionality of mobile devices (smartphones and tablets), wireless communication (Wi-Fi, Bluetooth and 3/4G), and positioning technologies (GPS, Assisted GPS and GLONASS) results in a new era of mobile geographic information systems (GIS) that aim at providing various invaluable services, including location-based services, intelligent transportation systems, logistics management, security and safety, etc. Many mobile GIS applications have been developed to solve challenging real-world problems and improve our quality of life.
Elevated CXC chemokines in urine noninvasively discriminate OAB from UTI
Authors: Tyagi Pradeep , Tyagi Vikas , Qu Xianggui , Chuang Yao Chi , Kuo Hann-Chorng , Chancellor Michael
Published: June 2016

Overlapping symptoms of overactive bladder (OAB) and urinary tract infection (UTI) often complicate the diagnosis and contribute to overprescription of antibiotics. Inflammatory response is a shared characteristic of both UTI and OAB and here we hypothesized that molecular differences in inflammatory response seen in urine can help discriminate OAB from UTI. Subjects in the age range of (20–88 yr) of either sex were recruited for this urine analysis study. Urine specimens were available from 62 UTI patients with positive dipstick test before antibiotic treatment. Six of these patients also provided urine after completion of antibiotic treatment. Subjects in cohorts of OAB ( n = 59) and asymptomatic controls ( n = 26) were negative for dipstick test. Urinary chemokines were measured by MILLIPLEX MAP Human Cytokine/Chemokine Immunoassay and their association with UTI and OAB was determined by univariate and multivariate statistics. Significant elevation of CXCL-1, CXCL-8 (IL-8), and CXCL-10 together with reduced levels for a receptor antagonist of IL-1A (sIL-1RA) were seen in UTI relative to OAB and asymptomatic controls. Elevated CXCL-1 urine levels predicted UTI with odds ratio of 1.018 and showed a specificity of 80.77% and sensitivity of 59.68%. Postantibiotic treatment, reduction was seen in all CXC chemokines with a significant reduction for CXCL-10. Strong association of CXCL-1 and CXCL-10 for UTI over OAB indicates mechanistic differences in signaling pathways driving inflammation secondary of infection in UTI compared with a lack of infection in OAB. Urinary chemokines highlight molecular differences in the paracrine signaling driving the overlapping symptoms of UTI and OAB.
Office-Based Case Finding for Chronic Obstructive Pulmonary Disease in Older Adults in Primary Care
Authors: Lee Linda , Patel Tejal , Hillier Loretta M. , Milligan James
Published: June 2016

Background. Chronic Obstructive Pulmonary Disease (COPD) is underdiagnosed in primary care.Aim. To explore the utility of proactive identification of COPD in patients 75 years of age and older in a Canadian primary care setting.Methods.Canadian Thoracic Society (CTS) screening questions were administered to patients with a smoking history of 20 pack-years or more; those with a positive screen were referred for postbronchodilator spirometry.Results. A total of 107 patients (21%), of 499 screened, had a 20-pack-year smoking history; 105 patients completed the CTS screening. Forty-four (42%) patients were positive on one or more questions on the screening; significantly more patients with a previous diagnosis of COPD (64%) were positive on the CTS compared to those without a previous diagnosis of COPD (30%). Of those who were not previously diagnosed with COPD (N= 11), four (36%) were newly diagnosed with COPD.Conclusion. A systematic two-stage method of screening for COPD, using CTS screening questions followed by spirometric confirmation, is feasible in the context of a busy primary care setting. More research is needed to assess the value of restricting screening to patients with a smoking history of 20 pack-years and on the sensitivity and specificity of these measures.
Macerals of Shengli Lignite in Inner Mongolia of China and Their Combustion Reactivity
Authors: Teng Ying Yue , Liu Yu Zhe , Liu Quan Sheng , Li Chang Qing
Published: June 2016

The macerals, including fusinitic coal containing 72.20% inertinite and xyloid coal containing 91.43% huminite, were separated from Shengli lignite using an optical microscope, and their combustion reactivity was examined by thermogravimetric analysis. Several combustion parameters, including ignition and burnout indices, were analyzed, and the combustion kinetics of the samples were calculated by regression. Fusinitic coal presented a porous structure, while xyloid coal presented a compact structure. The specific surface area of fusinitic coal was 2.5 times larger than that of xyloid coal, and the light-off temperature of the former was higher than that of the latter. However, the overall combustion reactivity of fusinitic coal was better than that of xyloid coal. The combustion processes of fusinitic and xyloid coals can be accurately described by both the homogeneous model and the shrinking core model. The features of xyloid coal agree with the shrinking core model when its conversion rate is 10%–90%. The activation energy of fusinitic coal during combustion can be divided into three phases, with the middle phase featuring the highest energy. The activation energy of xyloid coal is lower than that of fusinitic coal in the light-off phase, which may explain the low light-off temperature of this coal.
Passive Removal of Silicone Oil with Temporal Head Position through Two 23-Gauge Cannulas
Authors: Lin Zhong , Ke Zhi Sheng , Zheng Qian , Zhao Zhen Quan , Song Zong Ming
Published: June 2016

Purpose. To report a new approach for removal of silicone oil. Methods. All surgeries were performed using 23-gauge vitrectomy system with two transconjunctival sutureless cannulas. At the beginning, most of the silicone oil was removed by traditional microinvasive vitrectomy system through inferior-temporal cannula. Then, the blood transfusion tube is removed from the inferior-temporal cannula, and the fluid-air exchange is performed. A passive fluid-air exchange was performed to aspirate the residual silicone oil after gradually turning the patient’s head temporally by approximately 90° gradually. Results. After the surgery, all patients had a clear anterior chamber and vitreous cavity on slit lamp and B scan examination, respectively. The mean time taken for silicone oil removal and total surgery was 8.0±1.4 minutes and 12.4±2.5 minutes, respectively. The mean intraocular pressure 1 day, 3 days, 1 week, 1 month, and 3 months after surgery was 9.0±5.8 mmHg, 11.3±7.6 mmHg, 16.1±6.9 mmHg, 17.7±4.8 mmHg, and 17.1±3.5 mmHg, respectively. Conclusion. This new approach may provide a safe and fast method to remove the silicone oil.
On the Convergence of Solutions for SPDEs under Perturbation of the Domain
Authors: Guo Zhongkai , Liu Jicheng , Wang Wenya
Published: June 2016

We investigate the effect of domain perturbation on the behavior of mild solutions for a class of semilinear stochastic partial differential equations subject to the Dirichlet boundary condition. Under some assumptions, we obtain an estimate for the mild solutions under changes of the domain.