bluuebunny/crossref_metadata_2025 huggingface dataset:
GEKKO Optimization Suite
Authors: Beal Logan D. R. , Hill Daniel C. , Martin R. Abraham , Hedengren John D.
Published: August 2018

This paper introduces GEKKO as an optimization suite for Python. GEKKO specializes in dynamic optimization problems for mixed-integer, nonlinear, and differential algebraic equations (DAE) problems. By blending the approaches of typical algebraic modeling languages (AML) and optimal control packages, GEKKO greatly facilitates the development and application of tools such as nonlinear model predicative control (NMPC), real-time optimization (RTO), moving horizon estimation (MHE), and dynamic simulation. GEKKO is an object-oriented Python library that offers model construction, analysis tools, and visualization of simulation and optimization. In a single package, GEKKO provides model reduction, an object-oriented library for data reconciliation/model predictive control, and integrated problem construction/solution/visualization. This paper introduces the GEKKO Optimization Suite, presents GEKKO’s approach and unique place among AMLs and optimal control packages, and cites several examples of problems that are enabled by the GEKKO library.
A New Azimuth-Dependent Elevation Weight (ADEW) Model for Real-Time Deformation Monitoring in Complex Environment by Multi-GNSS
Authors: Han Junqiang , Huang Guanwen , Zhang Qin , Tu Rui , Du Yuan , Wang Xiaolei
Published: August 2018

Global navigation satellite systems (GNSS) have provided an excellent way to monitor micro-deformation in real-time. However, at local sites where landslides frequently occur, the environment can include complex surroundings with mountains, dense vegetation, and human settlements, which can severely degrade the accuracy of positioning with the GNSS technique. In this study, we propose an azimuth-dependent elevation weight (ADEW) model using an azimuth-dependent elevation mask (ADEM) to reduce the effects of multipath errors and improve the accuracy of real-time deformation monitoring in such environments. We developed an adaptive fixed-elevation mask to serve as the outlier of low precision observations at lower elevations for the ADEM, and then, we applied the weighted phase observations into the mitigation process for the effects of multipath errors. The real numerical results indicate that the ADEM model performs better than the conventional model, and the average improvements were 18.91% and 34.93% in the horizontal and vertical direction, respectively. The ADEW model further improved upon the ADEM model results by an additional 21.9% and 29.8% in the horizontal and vertical direction, respectively. Therefore, we propose that the ADEW model can significantly mitigate the effects of multipath errors and improve the accuracy of micro-deformation monitoring via GNSS receivers.
Visual Localizer: Outdoor Localization Based on ConvNet Descriptor and Global Optimization for Visually Impaired Pedestrians
Authors: Lin Shufei , Cheng Ruiqi , Wang Kaiwei , Yang Kailun
Published: August 2018

Localization systems play an important role in assisted navigation. Precise localization renders visually impaired people aware of ambient environments and prevents them from coming across potential hazards. The majority of visual localization algorithms, which are applied to autonomous vehicles, are not adaptable completely to the scenarios of assisted navigation. Those vehicle-based approaches are vulnerable to viewpoint, appearance and route changes (between database and query images) caused by wearable cameras of assistive devices. Facing these practical challenges, we propose Visual Localizer, which is composed of ConvNet descriptor and global optimization, to achieve robust visual localization for assisted navigation. The performance of five prevailing ConvNets are comprehensively compared, and GoogLeNet is found to feature the best performance on environmental invariance. By concatenating two compressed convolutional layers of GoogLeNet, we use only thousands of bytes to represent image efficiently. To further improve the robustness of image matching, we utilize the network flow model as a global optimization of image matching. The extensive experiments using images captured by visually impaired volunteers illustrate that the system performs well in the context of assisted navigation.
Three-Dimensional Imaging of Terahertz Circular SAR with Sparse Linear Array
Authors: Hao Jubo , Li Jin , Pi Yiming
Published: August 2018

Due to the non-contact detection ability of radar and the harmlessness of terahertz waves to the human body, three-dimensional (3D) imaging using terahertz synthetic aperture radar (SAR) is an efficient method of security detection in public areas. To achieve high-resolution and all aspect imaging, circular trajectory movement of radar and linear sensor array along the height direction were used in this study. However, the short wavelength of terahertz waves makes it practically impossible for the hardware to satisfy the half-wavelength spacing condition to avoid grating lobes. To solve this problem, a sparse linear array model based on the equivalent phase center principle was established. With the designed imaging geometry and corresponding echo signal model, a 3D imaging algorithm was derived. Firstly, the phase-preserving algorithm was adopted to obtain the 2D image of the ground plane for each sensor. Secondly, the sparse recovery method was applied to accomplish the scattering coefficient reconstruction along the height direction. After reconstruction of all the range-azimuth cells was accomplished, the final 3D image was obtained. Numerical simulations and experiments using terahertz radar were performed. The imaging results verify the effectiveness of the 3D imaging algorithm for the proposed model and validate the feasibility of terahertz radar applied in security detection.
Physical-Model-Checking to Detect Switching-Related Attacks in Power Systems
Authors: El Hariri Mohamad , Faddel Samy , Mohammed Osama
Published: August 2018

Recent public disclosures on attacks targeting the power industry showed that savvy attackers are now capable of occulting themselves from conventional rule-based network intrusion detection systems (IDS), bringing about serious threats. In order to leverage the work of rule-based IDS, this paper presents an artificially intelligent physical-model-checking intrusion detection framework capable of detecting tampered-with control commands from control centers of power grids. Unlike the work presented in the literature, the work in this paper utilizes artificial intelligence (AI) to learn the load flow characteristics of the power system and benefits from the fast responses of the AI to decode and understand contents of network packets. The output of the AI is processed through an expert system to verify that incoming control commands do not violate the physical system operational constraints and do not put the power system in an insecure state. The proposed content-aware IDS is tested in simulation on a 14-bus IEEE benchmark system. Experimental verification on a small power system, with an IEC 61850 network architecture is also carried out. The results showed the accuracy of the proposed framework in successfully detecting malicious and/or erroneous control commands.
Evaluation of the Effect of Fly Ash on Hydration Characterization in Self-Compacting Concrete (SCC) at Very Early Ages Using Piezoceramic Transducers
Authors: Zheng Yu , Chen Dongdong , Zhou Lingzhu , Huo Linsheng , Ma Hongwei , Song Gangbing
Published: August 2018

Nowadays, the industrial waste, Fly Ash (FA), as a mineral admixture or a replacement of cement for the production of self-compacting concrete (SCC) has been increasingly used, because of its benefits in enhancing both fresh and long-term concrete properties and in promoting environmental-friendly construction. In this study, the conventional cement was replaced by FA at different rates (0%, 20%, 40%, 60% of the cement mass) for the SCC mixtures. The early-age (0–24 h) SCC hydration, which is a complicated chemical reaction in pozzolanic behavior, was characterized by using a pair of piezoceramic Smart Aggregates (SAs). One SA works as an actuator and the other works as a sensor. A sweep sine signal from 100 Hz to100 kHz was used as the excitation signal, which is helpful to understand the quantitative influence of fly ash on the kinetics of SCC hydration. During the hydration reaction, the received electrical signal was continuously detected by the sensor. The experimental results showed that increasing the volume of fly ash resulted in longer pozzolanic reaction time in SCCs, which successfully reveals the effect of fly ash volume on the hydration behavior in early age (0–24 h) hydration. In order to quantitatively evaluate the hydration in the 0–24 h, based on the wavelet packet energy analysis, the hydration completion index (HCI) and normalized hydration completion index (NHCI) were defined. The experimental results showed that the NHCI can clearly reveal the hydration completion progress during the early hydration age (0–24 h). To validate the accuracy of the test results based on SAs, a series of mechanical tests for penetration resistance of SCCs with different volumes of fly ash were carried out. The results predicted by the signal based on SAs gave reasonable agreement with the test results of penetration resistance. It can be concluded that a successful investigation of the influence of fly ash on early-age SCC hydration response can be achieved based on the analysis of the received electrical signal using the proposed method and the important hydration characteristics, such as initial and final setting time, and can be approximately predicted by NHCI values.
Adaptive and Economically-Robust Group Selling of Spectrum Slots for Cognitive Radio-Based Networks
Authors: Ahmad Maqbool , Shafiq Muhammad , Irshad Azeem , Khalil Afzal Muhammad , Kim Dae Wan , Choi Jin-Ghoo
Published: August 2018

Auction theory has found vital application in cognitive radio to relieve spectrum scarcity by redistributing idle channels to those who value them most. However, countries have been slow to introduce spectrum auctions in the secondary market. This could be in part because a number of substantial conflicts could emerge for leasing the spectrum at the micro level. These representative conflicts include the lack of legislation, interference management, setting a reasonable price, etc. In addition, the heterogeneous nature of the spectrum precludes the true evaluation of non-identical channels. The information abstracted from the initial activity in terms of price paid for specific channels may not be a useful indicator for the valuation of another channel. Therefore, auction mechanisms to efficiently redistribute idle channels in the secondary market are of vital interest. In this paper, we first investigate such leading conflicts and then propose a novel Adaptive and Economically-Robust spectrum slot Group-selling scheme (AERG), for cognitive radio-based networks such as IoT, 5G and LTE-Advanced. This scheme enables group-selling behavior among the primary users to collectively sell their uplink slots that are individually not attractive to the buyers due to the auction overhead. AERG is based on two single-round sealed-bid reverse-auction mechanisms accomplished in three phases. In the first phase, participants adapt asks and bids to fairly evaluate uplink slots considering the dynamics of spectrum trading such as space and time. In the second phase, an inner-auction in each primary network is conducted to collect asks on group slots, and then, an outer-auction is held between primary and secondary networks. In the third phase, the winning primary network declares the winners of the inner-auction that can evenly share the revenue of the slots. Simulation results and logical proofs verify that AERG satisfies economic properties such as budget balance, truthfulness and individual rationality and improves the utilities of the participants.
Multiday EMG-Based Classification of Hand Motions with Deep Learning Techniques
Authors: Zia ur Rehman Muhammad , Waris Asim , Gilani Syed Omer , Jochumsen Mads , Niazi Imran Khan , Jamil Mohsin , Farina Dario , Kamavuako Ernest Nlandu
Published: August 2018

Pattern recognition of electromyography (EMG) signals can potentially improve the performance of myoelectric control for upper limb prostheses with respect to current clinical approaches based on direct control. However, the choice of features for classification is challenging and impacts long-term performance. Here, we propose the use of EMG raw signals as direct inputs to deep networks with intrinsic feature extraction capabilities recorded over multiple days. Seven able-bodied subjects performed six active motions (plus rest), and EMG signals were recorded for 15 consecutive days with two sessions per day using the MYO armband (MYB, a wearable EMG sensor). The classification was performed by a convolutional neural network (CNN) with raw bipolar EMG samples as the inputs, and the performance was compared with linear discriminant analysis (LDA) and stacked sparse autoencoders with features (SSAE-f) and raw samples (SSAE-r) as inputs. CNN outperformed (lower classification error) both LDA and SSAE-r in the within-session, between sessions on same day, between the pair of days, and leave-out one-day evaluation (p < 0.001) analyses. However, no significant difference was found between CNN and SSAE-f. These results demonstrated that CNN significantly improved performance and increased robustness over time compared with standard LDA with associated handcrafted features. This data-driven features extraction approach may overcome the problem of the feature calibration and selection in myoelectric control.
Portable System for Real-Time Detection of Stress Level
Authors: Minguillon Jesus , Perez Eduardo , Lopez-Gordo Miguel Angel , Pelayo Francisco , Sanchez-Carrion Maria Jose
Published: August 2018

Currently, mental stress is a major problem in our society. It is related to a wide variety of diseases and is mainly caused by daily-life factors. The use of mobile technology for healthcare purposes has dramatically increased during the last few years. In particular, for out-of-lab stress detection, a considerable number of biosignal-based methods and systems have been proposed. However, these approaches have not matured yet into applications that are reliable and useful enough to significantly improve people’s quality of life. Further research is needed. In this paper, we propose a portable system for real-time detection of stress based on multiple biosignals such as electroencephalography, electrocardiography, electromyography, and galvanic skin response. In order to validate our system, we conducted a study using a previously published and well-established methodology. In our study, ten subjects were stressed and then relaxed while their biosignals were simultaneously recorded with the portable system. The results show that our system can classify three levels of stress (stress, relax, and neutral) with a resolution of a few seconds and 86% accuracy. This suggests that the proposed system could have a relevant impact on people’s lives. It can be used to prevent stress episodes in many situations of everyday life such as work, school, and home.
A Calibration Method for Acoustic Space Charge Measurements Using Multilayer Samples
Authors: Mier-Escurra Guillermo , Rodrigo-Mor Armando , Vaessen Peter
Published: August 2018

Nowadays, the use of several methods for the measurement of space charges in dielectrics has become more relevant. The availability of different space charge measurement methods brings the necessity of calibration and characterization of measurement equipment to reach standardized measurements. In this paper, a method is presented to apply known charges at built samples which can be used for acoustic and thermal methods to compare measured values with calibration purposes. Experimental tests for validation purposes were performed in flat samples by comparison of results between a single layer and multilayer samples. Moreover, this method can be used to measure the resolution and accuracy of space charge measurement systems.
RPC-Based Orthorectification for Satellite Images Using FPGA
Authors: Zhang Rongting , Zhou Guoqing , Zhang Guangyun , Zhou Xiang , Huang Jingjin
Published: August 2018

Conventional rational polynomial coefficients (RPC)-based orthorectification methods are unable to satisfy the demands of timely responses to terrorist attacks and disaster rescue. To accelerate the orthorectification processing speed, we propose an on-board orthorectification method, i.e., a field-programmable gate array (FPGA)-based fixed-point (FP)-RPC orthorectification method. The proposed RPC algorithm is first modified using fixed-point arithmetic. Then, the FP-RPC algorithm is implemented using an FPGA chip. The proposed method is divided into three main modules: a reading parameters module, a coordinate transformation module, and an interpolation module. Two datasets are applied to validate the processing speed and accuracy that are achievable. Compared to the RPC method implemented using Matlab on a personal computer, the throughputs from the proposed method and the Matlab-based RPC method are 675.67 Mpixels/s and 61,070.24 pixels/s, respectively. This means that the proposed method is approximately 11,000 times faster than the Matlab-based RPC method to process the same satellite images. Moreover, the root-mean-square errors (RMSEs) of the row coordinate (ΔI), column coordinate (ΔJ), and the distance ΔS are 0.35 pixels, 0.30 pixels, and 0.46 pixels, respectively, for the first study area; and, for the second study area, they are 0.27 pixels, 0.36 pixels, and 0.44 pixels, respectively, which satisfies the correction accuracy requirements in practice.
Temperature Sensing Performance of Microsphere Resonators
Authors: Yu Jibo , Lewis Elfed , Brambilla Gilberto , Wang Pengfei
Published: August 2018

In recent years, many temperature sensing devices based on microsphere resonators have emerged, attracting an increasing research interest. For the purpose of this review article, microsphere resonators are divided according to their constituting materials, namely silicone, silica, compound glass, and liquid droplet. Temperature monitoring relies mainly on the thermo-optic/thermal expansion of the microspheres and on the fluorescence of the doped ions. This article presents a comprehensive review of the current state of the art of microsphere based temperature sensing and gives an indication of future directions.
Sources and Pathways of Formation of Recalcitrant and Residual Phosphorus in an Agricultural Soil
Authors: Joshi Sunendra R. , Li Wei , Bowden Mark , Jaisi Deb P.
Published: August 2018

Phosphorus (P) is an essential nutrient for sustaining life and agricultural production. Transformation of readily available P into forms that are unavailable to plants adds costs to P replenishment, which eventually translates into lower agronomic benefits and potential loss of soil P into runoff may degrade water quality. Therefore, understanding the sources and pathways of the formation of residual P pools in soils is useful information needed for the development of any technological or management efforts to minimize or inhibit the formation of such P pool and thus maximize availability to plants. In this research, we paired phosphate oxygen isotope ratios (δ18OP) with solid-state 31P NMR and quantitative XRD techniques along with general soil chemistry methods to identify the precipitation pathways of acid-extracted inorganic P (Pi) pools in an agricultural soil. Based on the comparison of isotope values of 0.5 mol L−1 NaOH-Pi, 1 mol L−1 HCl-Pi, and 10 mol L−1 HNO3-Pi pools and correlations of associated elements (Ca, Fe, and Al) in these pools, the HNO3-Pi pool appears most likely to be transformed from the NaOH-Pi pool. A narrow range of isotope values of acid-Pi pools in shallow (tilling depth) and below (where physical mixing is absent) is intriguing but likely suggests leaching of particle-bound P in deeper soils. Overall, these findings provide an improved understanding of the sources, transport, and transformation of acid-Pi pools in agricultural soils and further insights into the buildup of legacy P in soils.
Application of Multi-Species Differential Evolution Algorithm in Sustainable Microgrid Model
Authors: Zhang Hui-Juan , Feng Yi-Bo , Lin Kuo-Ping
Published: August 2018

The safety and stability of microgrid (MG) operations are closely related to the capacity of distributed energy resources. A conventional MG model usually adopts investment cost as an objective function. Recently, the issue of environmental protection has been gradually emphasized. Therefore, the objective function of the proposed sustainable microgrid (SMG) model in this study considers the investment cost and environmental protective cost and the decision variable is the capacity of the distributed power. Moreover, weather and electric power load data from the National Centers for Environmental Information database (2010) were analyzed in Matlab program for the case study of Alabaster city, United States of America (USA). For the sake of a stable and economical SMG operation, this study also attempts to use a multi-objective capacity optimal model for effectively solving SMG under a multi-population differential evolution (MPDE) algorithm with dominant population (DP), which can improve the convergence speed in an SMG model. At the same time, considering that different scheduling strategies will also affect the optimization results, two strategies are proposed for the priority order of distributed generation sources. The optimization results under the two scheduling strategies show that the validation of the MPDE algorithm in SMG capacity optimization problems can economize investment costs and enable an environmentally friendly power supply.
Fermion Scattering in a CPT-Even Lorentz Violation Quantum Electrodynamics
Authors: Santos Frederico , Ferreira Manoel
Published: August 2018

In this work, we reassess two known processes of Quantum Electrodynamics involving electrons and muons. The photon propagator is modified by a CPT-even Lorentz-violating (LV) tensor, while fermion lines and the vertex interaction are not altered. Using the Feynman rules, the associated cross sections for unpolarized scatterings are evaluated, revealing the usual energy dependence and Lorentz-violating contributions that induce space anisotropy. A possible route to constraining the LV coefficients is presented and the results properly commented.
Urban Inequality: The City after the 2007 Crisis
Authors: González-Pérez Jesús M.
Published: August 2018

After the impact of the 2007 crisis and post-crisis austerity policies, cities are being reconfigured under the auspices of inequality. Social divides are widening, and there is a growing population of excluded and poor people. The urban and welfare state crises of the 1980s are currently being replicated, albeit even more acutely, given that the welfare state in many countries is very weak and there are worrying signs of a crisis of democracy. In the present urban order of globalization, new players have emerged from the financial sector, including investment funds and the so-called vulture funds. Our contribution to this Special Issue is an analysis of urban inequality today based on theoretical and empirical research. The issue includes articles on social movements and resistance in Latin American cities, vulnerability in crisis-hit Spanish cities, and the segregation and quality of basic services in US cities.
Quantifying the Observational Effort Required for the Radial Velocity Characterization of TESS Planets
Authors: Cloutier Ryan , Doyon René , Bouchy Francois , Hébrard Guillaume
Published: August 2018

The Transiting Exoplanet Survey Satellite (TESS) will conduct a two-year wide-field survey searching for transiting planets around bright stars. Many TESS discoveries will be amenable to mass characterization via ground-based radial velocity measurements with any of a growing suite of existing and anticipated velocimeters in the optical and near-infrared. In this study we present an analytical formalism to compute the number of radial velocity (RV) measurements—and hence the total observing time—required to characterize RV planet masses with the inclusion of either a white or correlated noise activity model. We use our model to calculate the total observing time required to measure all TESS planet masses from the expected TESS planet yield while relying on our current understanding of the targeted stars, stellar activity, and populations of unseen planets that inform the expected RV precision. We also present specialized calculations applicable to a variety of interesting subsets of TESS planets including the characterization of 50 planets smaller than 4 Earth radii, which is expected to take as little as 60 nights of observation. However, the efficient RV characterization of such planets requires a priori knowledge of the “best” targets, which we argue can be identified prior to the conclusion of the TESS planet search based on our calculations. Our results highlight the comparable performance of optical and near-IR spectrographs for most planet populations except for Earths and temperate TESS planets, which are more efficiently characterized in the near-IR. Lastly, we present an online tool to the community to compute the total observing times required to detect any transiting planet using a user-defined spectrograph (RVFC; http://maestria.astro.umontreal.ca/rvfc).
Discovery and Dynamical Analysis of an Extreme Trans-Neptunian Object with a High Orbital Inclination
Authors: Becker J. C. , Khain T. , Hamilton S. J. , Adams F. C. , Gerdes D. W. , Zullo L. , Franson K. , Millholland S. , Bernstein G. M. , Sako M. , Bernardinelli P. , Napier K. , Markwardt L. , Lin 林 Hsing Wen 省文 , Wester W. , Abdalla F. B. , Allam S. , Annis J. , Avila S. , Bertin E. , Brooks D. , Rosell A. Carnero , Kind M. Carrasco , Carretero J. , Cunha C. E. , D’Andrea C. B. , Costa L. N. da , Davis C. , Vicente J. De , Diehl H. T. , Doel P. , Eifler T. F. , Flaugher B. , Fosalba P. , Frieman J. , García-Bellido J. , Gaztanaga E. , Gruen D. , Gruendl R. A. , Gschwend J. , Gutierrez G. , Hartley W. G. , Hollowood D. L. , Honscheid K. , James D. J. , Kuehn K. , Kuropatkin N. , Maia M. A. G. , March M. , Marshall J. L. , Menanteau F. , Miquel R. , Ogando R. L. C. , Plazas A. A. , Sanchez E. , Scarpine V. , Schindler R. , Sevilla-Noarbe I. , Smith M. , Smith R. C. , Soares-Santos M. , Sobreira F. , Suchyta E. , Swanson M. E. C. , Walker A. R. ,   (DES Collaboration)
Published: August 2018

We report the discovery and dynamical analysis of 2015 BP519, an extreme trans-Neptunian object (TNO) detected by the Dark Energy Survey at a heliocentric distance of 55 au, perihelion of ∼36 au, and absolute magnitude H

r
 = 4.3. The current orbit, determined from a 1110 day observational arc, has a semimajor axis a ≈ 450 au, eccentricity e ≈ 0.92, and inclination i ≈ 54°. With these orbital elements, 2015 BP519 is the most extreme TNO discovered to date, as quantified by the reduced Kozai action,

, which is a conserved quantity at fixed semimajor axis a for axisymmetric perturbations. We discuss the orbital stability and evolution of this object and find that, under the influence of the four known giant planets, 2015 BP519 displays rich dynamical behavior, including rapid diffusion in semimajor axis and more constrained variations in eccentricity and inclination. We also consider the long-term orbital stability and evolutionary behavior within the context of the Planet Nine hypothesis and find that 2015 BP519 adds to the circumstantial evidence for the existence of this proposed new member of the solar system, as it would represent the first member of the population of high-i, ϖ-shepherded TNOs.
Can Rocky Exoplanets with Rings Pose as Sub-Neptunes?
Authors: Piro Anthony L.
Published: August 2018

In our solar system, the presence of rings is exclusive to the gas giants, but is this the case for all planetary systems? In principle, it seems that rocky exoplanets could also have rings, which could be searched for by studying their subtle imprint on the ingress and egress of transits. Unfortunately, such effects are difficult to measure and require high-precision photometric and/or spectroscopic observations. At the most basic level though, the presence of rings would result in an increased transit depth that could be mistaken as an anonymously large radius. Motivated by this, I consider how a population of exoplanets with rings would impact radius measurements, focusing on Earth-like exoplanets. It is found that this population introduces an enhancement of inferred radii in the range of ∼2–3 R
⊕, not unlike the sub-Neptunes that have been identified in recent transit surveys. Whether rings can explain all or most sub-Neptunes seems difficult, since it would require a large fraction of rocky planets to have rings (≳40%) and/or a factor of ∼2–3 increase in the number of planets with radii ≲1.2 R
⊕. Even if rings cannot explain all sub-Neptunes, this work suggests that focusing on those planets currently classified as sub-Neptunes may be a good starting place for finding rocky planets with rings.
Born Kernels for the Helioseismic Fourier–Legendre Analysis Method
Authors: Hecht Emanuel , Roth Markus
Published: August 2018

Measuring large-scale flows like the meridional flow with helioseismic methods plays a crucial role for understanding solar dynamics. In this work, we develop a detailed forward model for the Fourier–Legendre analysis method. This method has initially been applied for measuring the meridional flow by Braun & Fan, who observed frequency shifts between poleward and equatorward traveling p-modes. However, a detailed theoretical model based on a description of the solar internal wavefield is lacking. We therefore describe the effect of advection on the acoustic wavefronts in the first Born approximation following the framework of Gizon & Birch. We derive 2D sensitivity kernels for a suitable and unified definition of the frequency shift, and validate them on the example of a meridional flow. Finally, an inversion technique to estimate the meridional flow is developed on the basis of synthetic data from a simulation of linear wave propagation.
Observations of the Electron Jet Generated by Secondary Reconnection in the Terrestrial Magnetotail
Authors: Huang S. Y. , Jiang K. , Yuan Z. G. , Sahraoui F. , He L. H. , Zhou M. , Fu H. S. , Deng X. H. , He J. S. , Cao D. , Yu X. D. , Wang D. D. , Burch J. L. , Pollock C. J. , Torbert R. B.
Published: August 2018

We report in situ observations of an electron jet generated by secondary reconnection within the outflow region of primary reconnection in the terrestrial magnetotail by the Magnetospheric Multiscale (MMS) mission. The MMS spacecraft first passed through the primary X-line and then crossed the electron jet in the outflow of primary reconnection. There are a series of small-scale flux ropes in the secondary reconnection region. Decoupling from the magnetic field for both ions and electrons, an intense out-of-plane current, unambiguous Hall currents, and a Hall electromagnetic field appear in the electron jet. Strong electron dissipation (

), a nonzero electric field in the electron frame (

), and electron crescent-like shaped distributions are detected in the center of the electron jet, implying that MMS spacecraft were likely passing through the electron diffusion region. The significant electron dissipation indicates that the electrons can be accelerated in the electron jet and the electron jet may be another important electron acceleration channel along with the electron diffusion region.
Cosmic-Ray Short Burst Observed with the Global Muon Detector Network (GMDN) on 2015 June 22
Authors: Munakata K. , Kozai M. , Evenson P. , Kuwabara T. , Kato C. , Tokumaru M. , Rockenbach M. , Lago A. Dal , de Mendonca R. R. S. , Braga C. R. , Schuch N. J. , Jassar H. K. Al , Sharma M. M. , Duldig M. L. , Humble J. E. , Sabbah I. , Kóta J.
Published: August 2018

We analyze the short cosmic-ray intensity increase (“cosmic-ray burst”: CRB) on 2015 June 22 utilizing a global network of muon detectors and derive the global anisotropy of cosmic-ray intensity and the density (i.e., the omnidirectional intensity) with 10 minute time resolution. We find that the CRB was caused by a local density maximum and an enhanced anisotropy of cosmic rays, both of which appeared in association with Earth’s crossing of the heliospheric current sheet (HCS). This enhanced anisotropy was normal to the HCS and consistent with a diamagnetic drift arising from the spatial gradient of cosmic-ray density, which indicates that cosmic rays were drifting along the HCS from the north of Earth. We also find a significant anisotropy along the HCS, lasting a few hours after the HCS crossing, indicating that cosmic rays penetrated into the inner heliosphere along the HCS. Based on the latest geomagnetic field model, we quantitatively evaluate the reduction of the geomagnetic cutoff rigidity and the variation of the asymptotic viewing direction of cosmic rays due to a major geomagnetic storm that occurred during the CRB and conclude that the CRB is not caused by the geomagnetic storm, but by a rapid change in the cosmic-ray anisotropy and density outside the magnetosphere.
The Hour-timescale GeV Flares of PSR B1259–63 in 2017
Authors: Tam P. H. T. , He X.-B. , Pal P. S. , Cui Yudong
Published: August 2018

GeV flares from PSR B1259−63/LS 2883 were seen starting around 30 days after the two periastron passages in 2010 and 2014. The flares are clearly delayed compared to the occurrence of the X-ray and TeV flux peaks during the post-periastron disk crossing. Although several attempts have been put forward to explain this phenomenon, the origin of these GeV flares remains a puzzle. Here we present a detailed analysis of the observational data taken by the Fermi and Swift observatories over the 2017 September periastron passage. For the first time, we find short-lived but powerful GeV flares on timescales of down to three hours. The onset of the GeV flaring period in 2017 is also delayed compared to that seen in 2011 and 2014. Supplemented by a reanalysis of previous data, we compare the Fermi/LAT, Swift/XRT, and Swift/UVOT light curves in 2017 with those taken over the 2010 and 2014 periastrons, and differences in UVOT light curves are noted.
The Search for Extra-Galactic Intelligence Signals Synchronized with Binary Neutron Star Mergers
Authors: Nishino Yuki , Seto Naoki
Published: August 2018

We discuss the possibility of receiving a radio signal from extra-Galactic intelligence, around the time when we observe a binary neutron star merger in their galaxy. High-precession measurements of the binary parameters would allow them to send the signal ∼104 years before they themselves observe the merger signal. Using the SKA, we might receive ∼104 bits of data, transmitted from 40 Mpc away with an output power of ∼1TW. We also discuss related topics for GW170817 and mention potential roles of future gravitational wave detectors in relation to this transmission scheme.
Near-infrared Emission Lines in Starburst Galaxies at 0.5 < z < 0.9: Discovery of a Merger Sequence of Extreme Obscurations
Authors: Calabrò A. , Daddi E. , Cassata P. , Onodera M. , Gobat R. , Puglisi A. , Jin S. , Liu D. , Amorín R. , Arimoto N. , Boquien M. , Carraro R. , Elbaz D. , Ibar E. , Juneau S. , Mannucci F. , Méndez Hernánez H. , Oliva E. , Rodighiero G. , Valentino F. , Zanella A.
Published: August 2018

We obtained optical/near-IR rest-frame Magellan FIRE spectra (including Paβ and Paγ) of 25 starburst galaxies at 0.5 < z < 0.9, with average star formation rates (SFRs) seven times above the main sequence (MS). We find that Paschen-to-Balmer line ratios saturate around a constant value corresponding to A
V ∼ 2–3 mag, while line-to-IR-luminosity ratios suggest a large range of more extreme obscurations and appear to be uncorrelated with the former. This behavior is not consistent with standard attenuation laws derived for local and distant galaxies, yet is remarkably consistent with observations of starburst cores in which young stars and dust are homogeneously mixed. This model implies A
V = 2–30 mag attenuation to the center of starburst cores, with a median of ∼9 mag (a factor of 4000). X-ray hardness ratios for six AGNs in our sample and column densities derived from observed dust masses and radio sizes independently confirm this level of attenuation. In these conditions observed optical/near-IR emission comes from surface regions, while inner starburst cores are invisible. We thus attribute the high [N ii]/Hα ratios to widespread shocks from accretion, turbulence, and dynamic disturbances rather than to AGNs. The large range of optical depths demonstrates that substantial diversity is present within the starburst population, possibly connected to different merger phases or progenitor properties. The majority of our targets are, in fact, morphologically classified as mergers. We argue that the extreme obscuration provides in itself smoking gun evidence of their merger origin, and a powerful tool for identifying mergers at even higher redshifts.
Collective Study of Polar Crown Filaments in the Past Four Solar Cycles
Authors: Xu Yan , Pötzi Werner , Zhang Hewei , Huang Nengyi , Jing Ju , Wang Haimin
Published: August 2018

Polar crown filaments (PCFs) form above the magnetic polarity inversion line, which separates the unipolar polar fields and the nearest dispersed fields from the trailing part of active regions with opposite polarity. The statistical properties of PCFs are correlated with the solar cycle. Therefore, the study of PCFs plays an important role in understanding the variations of the solar cycle, especially the prolonged cycle 23 and the current “abnormal” solar cycle 24. In this Letter, we investigate PCFs using full-disk Hα data from 1973 to early 2018, recorded by Kanzelhöhe Solar Observatory and Big Bear Solar Observatory, in digital form from 1997 to 2018 and in 35 mm film (digitized) from 1973 to 1996. PCFs are identified manually because their segmented shape and close-to-limb location were not handled well by automatical detections in several previous studies. Our results show that the PCFs start to move poleward at the beginning of each solar cycle. When the PCFs approach to the maximum latitude, the polar field strength reduces to zero followed by a reversal. The migration rates are about 0.°4 to 0.°7 per Carrington rotation, with a clear N–S asymmetric pattern. In cycles 21 and 23, the PCFs in the northern hemisphere migrate faster than those in the southern hemisphere. However, in the “abnormal” cycle 24, the southern PCFs migrate faster, which is consistent with other observations of magnetic fields and radio emission. In addition, there are more days in cycle 23 and 24 without PCFs than in the previous cycles.
L’expérience économique du gouvernement Hamas sous blocus dans la bande de Gaza
Authors: Labadi Taher
Published: August 2018

Le blocus de la bande de Gaza ainsi que les guerres successives menées par Israël au cours de la dernière décennie ont provoqué une grave crise économique et humanitaire sur cette portion du territoire palestinien. S’ajoute à cela un contexte de fracture politique interne entre le Hamas qui gouverne la bande de Gaza et l’Autorité palestinienne établie en Cisjordanie. J’examine certaines pratiques et politiques inédites du gouvernement de Gaza sous blocus qui nous renseignent sur le caractère à la fois éminemment conflictuel et nécessairement précaire des tentatives d’adaptation, d’autonomisation et de régulation de l’activité économique en temps de guerre. Trois expériences en particulier sont étudiées : l’entreprise du ministère de l’Agriculture pour développer une production en situation d’autarcie ; le recours aux réseaux de contrebande et l’exploitation des tunnels à la frontière avec l’Égypte ; l’effort pour fonder un système administratif et financier parallèle dans un contexte de souveraineté partagée.
La région libanaise de Wadi Khaled à la frontière avec la Syrie : quelles transformations économiques en temps de paix et de guerre ?
Authors: Mouawad Jamil , Périer Miriam
Published: August 2018

Cet article propose une lecture historique des principales transformations de la vie économique – en temps de paix comme en temps de guerre – dans la région libanaise de Wadi Khaled, à la frontière nord avec la Syrie. Nous examinons ces transformations en considérant les fluctuations incessantes des processus de frontiérisation et de refrontiérisation, et montrons que les moyens de subsistance des habitants de la région reposent sur la différence des systèmes économiques libanais et syriens et sur la porosité de la frontière, notamment, pour le commerce et la contrebande. L’irruption de la guerre en Syrie à la fin de l’année 2011 a progressivement refermé la frontière. Devenue à la fois plus rigide et imperméable, elle n’a plus permis aux habitants de Wadi Khaled de maintenir leur source de revenus principale. Une dépendance à la présence des réfugiés syriens s’est installée et une nouvelle frontière s’est trouvée en partage : celle entre une communauté d’accueil et des réfugiés. Nous montrons ainsi comment la région est passée d’une dépendance économique à la Syrie à une dépendance économique aux Syriens venus trouver refuge dans cette région limitrophe, et comment, finalement, cette zone est inextricablement liée à la Syrie, que la frontière soit poreuse ou pas.
Une économie de la survie au plus près de la guerre. Stratégies quotidiennes des réfugiés syriens à Nabaa
Authors: Boissière Thierry , Tohmé Tabet Annie
Published: August 2018

À la jonction de l’anthropologie urbaine et économique, de la sociologie des migrations et d’une ethnographie des pratiques du quotidien, cette étude présente les premiers résultats d’un travail de terrain en cours. Elle analyse la façon dont les réfugiés syriens prennent place dans Nabaa, un quartier populaire de la banlieue est de Beyrouth, et les types de dispositifs, notamment résidentiels et économiques, sur lesquels ils s’appuient au quotidien. Notre analyse prend en compte leurs trajectoires depuis la Syrie jusqu’à leur installation dans le quartier, ainsi que le développement d’activités économiques et de survie. Elle pose enfin la question des conditions de la construction d’un quotidien dans l’exil, notamment à travers la mise en place de formes de routines dans un contexte d’incertitude et de grande précarité matérielle, sociale, politique et statutaire.
Emplacement et organisation de l’espace funéraire en Anatolie occidentale au Bronze Ancien (IIIe millénaire)
Authors: Perello Bérengère
Published: August 2018

En Anatolie occidentale, le Bronze Ancien est caractérisé par l’apparition de nécropoles extra-muros, notamment à Demirci-Sarıket, Karataş-Elmalı, Kusura et Yortan. Ainsi, les quelques exemples référencés d’inhumation intra-muros sous le sol des habitations font figure d’exceptions (Beycesultan, Ovabayındır, Troie). Nous verrons que, au-delà de la distinction topographique, l’émergence des nécropoles extra-muros inaugure un changement majeur dans les relations entre le monde des vivants et le monde des morts et nous renseigne sur la structure et le fonctionnement de ces sociétés protohistoriques.
Dead people among the living?
Authors: Hülden Oliver
Published: August 2018

Although in Lycia the most tombs are situated outside the city walls – as well as in other parts of the ancient world – the existence of intramural burials is discussed since the days of the first travellers of the 19th century. Especially a comment of O. Benndorf and G. Niemann describing that Lycian tombs are often combined with intramural individual houses – a combination which seems to blur the boundaries between the settlement and the necropolis – had a large impact on later scholars. In this paper I will give a general and diachronic but also a critical overview of this phenomenon especially based on observations made in the necropoleis of Xanthos and the settlement on the Avşar Tepesi (Zagaba?).
Wandering Cemeteries
Authors: Steskal Martin
Published: August 2018

Like most other ancient cities, Ephesus was surrounded by large-scale necropoleis. Except for a few examples, the typical burial sites were located in extramural burial areas outside the Hellenistic city-walls.Sanitary precautions and fear of defilement readily explain this law. So, no matter from what direction an ancient traveler arrived in Ephesus, he had to pass a cemetery. Although no longer visible today the relationship between tombs and city appeared to be heterogeneous: On the one hand they were packed tightly around inhabited areas, on the other hand they were located on uninhabited slopes. The common denominator is their location in heavily frequented areas or next to major traffic routes; this made them noticeable and permanently present to the citizens of the ancient city. The structure, the architectural design and the furnishings of the tombs so prominently sited served as vehicles for any kind of status display and a definition of social hierarchies.Intramural burials were very rare, and they were granted by cities only as a mark of high distinction and were typically restricted to exceptional cases. In this paper several remarkable funerary and honorific monuments located along the Curetes Street are presented.The important rank of the owners of these monuments in Ephesian society was reﬂected by the centrality of their monuments within the civic landscape.The law of extramural burials changed to a certain extent in late antiquity, when Christians were allowed to bury the deceased adjacent to or even in churches.It was of no importance whether the churches were located inside or outside the cities. Together with the abandonment of vast mortuary areas starting at the end of the 5th century AD a ‘wandering’ of the Ephesian burial sites can be discerned. This change of the mortuary landscape from early Imperial to late antiquity within the capital of the Roman province of Asia will be the focus of this paper.
L'Inra et l'international. Opportunités, apprentissages et tâtonnements stratégiques (de la fondation de l'Institut aux années soixante-dix)
Authors: Martone Lisalou
Published: August 2018

The National Institute for Agricultural Research (INRA) was founded in the aftermath of World War 2 in order to regenerate France’s power. The institute has since developed a complex and original relationship to the international scientific landscape, both trying to meet the challenge of Anglo-Saxon countries mainly, and aiming at rebuilding an area of influence in the developing world by the means of scientific cooperation. Built on a cross-over study of oral and administrative archives, this paper sets light on the international acculturation of French agronomic research up to the beginning of the 1980’s.
Radioscoper une discipline grâce à son répertoire professionnel
Authors: Cuyala Sylvain , Commenges Hadrien
Published: August 2018

Les études qui s’intéressent à la structuration des disciplines mobilisent une grande diversité de sources et de méthodes. Malgré cette diversité, il existe une source largement inexploitée alors qu’elle est disponible dans de nombreuses disciplines : le répertoire professionnel. Cet article propose une méthode d’exploitation des répertoires professionnels pour étudier les disciplines de manière systématique, à la fois dans le temps et dans l’espace. Pas à pas sont expliquées les étapes mises en place pour extraire l’information du bottin, pour produire une information de cadrage, pour explorer certains aspects de la structure des disciplines et de leur organisation spatiale. Enfin, ce parcours méthodologique est illustré par un exemple d’application et des pistes sont proposées pour l’articulation de cette méthode avec l’analyse d’un corpus d’entretiens.