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  • American Physical Society (APS)  (149,527)
  • MDPI Publishing
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  • 1
    Publication Date: 2018-08-13
    Description: Remote Sensing, Vol. 10, Pages 1271: Spectral and Spatial Classification of Hyperspectral Images Based on Random Multi-Graphs Remote Sensing doi: 10.3390/rs10081271 Authors: Feng Gao Qun Wang Junyu Dong Qizhi Xu Hyperspectral image classification has been acknowledged as the fundamental and challenging task of hyperspectral data processing. The abundance of spectral and spatial information has provided great opportunities to effectively characterize and identify ground materials. In this paper, we propose a spectral and spatial classification framework for hyperspectral images based on Random Multi-Graphs (RMGs). The RMG is a graph-based ensemble learning method, which is rarely considered in hyperspectral image classification. It is empirically verified that the semi-supervised RMG deals well with small sample setting problems. This kind of problem is very common in hyperspectral image applications. In the proposed method, spatial features are extracted based on linear prediction error analysis and local binary patterns; spatial features and spectral features are then stacked into high dimensional vectors. The high dimensional vectors are fed into the RMG for classification. By randomly selecting a subset of features to create a graph, the proposed method can achieve excellent classification performance. The experiments on three real hyperspectral datasets have demonstrated that the proposed method exhibits better performance than several closely related methods.
    Electronic ISSN: 2072-4292
    Topics: Architecture, Civil Engineering, Surveying , Geography
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  • 2
    Publication Date: 2018-08-13
    Description: Materials, Vol. 11, Pages 1413: Fused Particle Fabrication 3-D Printing: Recycled Materials’ Optimization and Mechanical Properties Materials doi: 10.3390/ma11081413 Authors: Aubrey L. Woern Dennis J. Byard Robert B. Oakley Matthew J. Fiedler Samantha L. Snabes Joshua M. Pearce Fused particle fabrication (FPF) (or fused granular fabrication (FGF)) has potential for increasing recycled polymers in 3-D printing. Here, the open source Gigabot X is used to develop a new method to optimize FPF/FGF for recycled materials. Virgin polylactic acid (PLA) pellets and prints were analyzed and were then compared to four recycled polymers including the two most popular printing materials (PLA and acrylonitrile butadiene styrene (ABS)) as well as the two most common waste plastics (polyethylene terephthalate (PET) and polypropylene (PP)). The size characteristics of the various materials were quantified using digital image processing. Then, power and nozzle velocity matrices were used to optimize the print speed, and a print test was used to maximize the output for a two-temperature stage extruder for a given polymer feedstock. ASTM type 4 tensile tests were used to determine the mechanical properties of each plastic when they were printed with a particle drive extruder system and were compared with filament printing. The results showed that the Gigabot X can print materials 6.5× to 13× faster than conventional printers depending on the material, with no significant reduction in the mechanical properties. It was concluded that the Gigabot X and similar FPF/FGF printers can utilize a wide range of recycled polymer materials with minimal post processing.
    Electronic ISSN: 1996-1944
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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  • 3
    Publication Date: 2018-08-13
    Description: Materials, Vol. 11, Pages 1414: Numerical-Experimental Study of the Consolidation Phenomenon in the Selective Laser Melting Process with a Thermo-Fluidic Coupled Model Materials doi: 10.3390/ma11081414 Authors: Francisco Cordovilla Ángel García-Beltrán Miguel Garzón Diego A. Muñoz José L. Ocaña One of the main limiting factors for a widespread industrial use of the Selective Laser Melting Process it its lack of productivity, which restricts the use of this technology just for high added-value components. Typically, the thickness of the metallic powder that is used lies on the scale of micrometers. The use of a layer up to one millimeter would be necessarily associated to a dramatic increase of productivity. Nevertheless, when the layer thickness increases, the complexity of consolidation phenomena makes the process difficult to be governed. The present work proposes a 3D finite element thermo-coupled model to study the evolution from the metallic powder to the final consolidated material, analyzing specifically the movements and loads of the melt pool, and defining the behavior of some critical thermophysical properties as a function of temperature and the phase of the material. This model uses advanced numerical tools such as the Arbitrary Lagrangean–Eulerian formulation and the Automatic Remeshing technique. A series of experiments have been carried out, using a high thickness powder layer, allowing for a deeper understanding of the consolidation phenomena and providing a reference to compare the results of the numerical calculations.
    Electronic ISSN: 1996-1944
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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  • 4
    Publication Date: 2018-08-13
    Description: Remote Sensing, Vol. 10, Pages 1269: Panoramic Image and Three-Axis Laser Scanner Integrated Approach for Indoor 3D Mapping Remote Sensing doi: 10.3390/rs10081269 Authors: Pengcheng Zhao Qingwu Hu Shaohua Wang Mingyao Ai Qingzhou Mao High-precision indoor three-dimensional maps are a prerequisite for building information models, indoor location-based services, etc., but the indoor mapping solution is still in the stage of technological experiment and application scenario development. In this paper, indoor mapping equipment integrating a three-axis laser scanner and panoramic camera is designed, and the corresponding workflow and critical technologies are described. First, hardware design and software for controlling the operations and calibration of the spatial relationship between sensors are completed. Then, the trajectory of the carrier is evaluated by a simultaneous location and mapping framework, which includes reckoning of the real-time position and attitude of the carrier by a filter fusing the horizontally placed laser scanner data and inertial measurement data, as well as the global optimization by a closed-loop adjustment using a graph optimization algorithm. Finally, the 3D point clouds and panoramic images of the scene are reconstructed from two tilt-mounted laser scanners and the panoramic camera by synchronization of the position and attitude of the carrier. The experiment was carried out in a five-story library using the proposed prototype system; the results demonstrate accuracies of up to 3 cm for 2D maps, and up to 5 cm for 3D maps, and the produced point clouds and panoramic images can be utilized for modeling and further works related to large-scale indoor scenes. Therefore, the proposed system is an efficient and accurate solution for indoor 3D mapping.
    Electronic ISSN: 2072-4292
    Topics: Architecture, Civil Engineering, Surveying , Geography
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  • 5
    Publication Date: 2018-08-13
    Description: Remote Sensing, Vol. 10, Pages 1270: Greening and Browning of the Hexi Corridor in Northwest China: Spatial Patterns and Responses to Climatic Variability and Anthropogenic Drivers Remote Sensing doi: 10.3390/rs10081270 Authors: Qingyu Guan Liqin Yang Ninghui Pan Jinkuo Lin Chuanqi Xu Feifei Wang Zeyu Liu The arid region of northwest China provides a unique terrestrial ecosystem to identify the response of vegetation activities to natural and anthropogenic changes. To reveal the influences of climate and anthropogenic factors on vegetation, the Normalized Difference Vegetation Index (NDVI), climate data, and land use and land cover change (LUCC) maps were used for this study. We analyzed the spatiotemporal change of NDVI during 2000–2015. A partial correlation analysis suggested that the contribution of precipitation (PRE) and temperature (TEM) on 95.43% of observed greening trends was 47% and 20%, respectively. The response of NDVI in the eastern section of the Qilian Mountains (ESQM) and the western section of the Qilian Mountains (WSQM) to PRE and TEM showed opposite trends. The multiple linear regressions used to quantify the contribution of anthropogenic activity on the NDVI trend indicated that the ESQM and oasis areas were mainly affected by anthropogenic activities (26%). The observed browning trend in the ESQM was attributed to excessive consumption of natural resources. A buffer analysis and piecewise regression methods were further applied to explore the influence of urbanization on NDVI and its change rate. The study demonstrated that urbanization destroys the vegetation cover within the developed city areas and extends about 4 km beyond the perimeter of urban areas and the NDVI of buffer cities (counties) in the range of 0–4 km (0–3 km) increased significantly. In the range of 5–15 (4–10) km (except for Jiayuguan), climate factors were the major drivers of a slight downtrend in the NDVI. The relationship of land use change and NDVI trends showed that construction land, urban settlement, and farmland expanded sharply by 171.43%, 60%, and 10.41%, respectively. It indicated that the rapid process of urbanization and coordinated urban-rural development shrunk ecosystem services.
    Electronic ISSN: 2072-4292
    Topics: Architecture, Civil Engineering, Surveying , Geography
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  • 6
    Publication Date: 2018-08-13
    Description: Sensors, Vol. 18, Pages 2640: Spatial Extension of Road Traffic Sensor Data with Artificial Neural Networks Sensors doi: 10.3390/s18082640 Authors: Mariano Gallo Giuseppina De Luca This paper proposes a method for estimating traffic flows on some links of a road network knowing the data on other links that are monitored with sensors. In this way, it is possible to obtain more information on traffic conditions without increasing the number of monitored links. The proposed method is based on artificial neural networks (ANNs), wherein the input data are the traffic flows on some monitored road links and the output data are the traffic flows on some unmonitored links. We have implemented and tested several single-layer feed-forward ANNs that differ in the number of neurons and the method of generating datasets for training. The proposed ANNs were trained with a supervised learning approach where input and output example datasets were generated through traffic simulation techniques. The proposed method was tested on a real-scale network and gave very good results if the travel demand patterns were known and used for generating example datasets, and promising results if the demand patterns were not considered in the procedure. Numerical results have underlined that the ANNs with few neurons were more effective than the ones with many neurons in this specific problem.
    Electronic ISSN: 1424-8220
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
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  • 7
    Publication Date: 2018-08-13
    Description: Sensors, Vol. 18, Pages 2643: Galfenol Thin Films and Nanowires Sensors doi: 10.3390/s18082643 Authors: Bethanie J. H. Stadler Madhukar Reddy Rajneeta Basantkumar Patrick McGary Eliot Estrine Xiaobo Huang Sang Yeob Sung Liwen Tan Jia Zou Mazin Maqableh Daniel Shore Thomas Gage Joseph Um Matthew Hein Anirudh Sharma Galfenol (Fe1−xGax, 10 < x < 40) may be the only smart material that can be made by electrochemical deposition which enables thick film and nanowire structures. This article reviews the deposition, characterization, and applications of Galfenol thin films and nanowires. Galfenol films have been made by sputter deposition as well as by electrochemical deposition, which can be difficult due to the insolubility of gallium. However, a stable process has been developed, using citrate complexing, a rotating disk electrode, Cu seed layers, and pulsed deposition. Galfenol thin films and nanowires have been characterized for crystal structures and magnetostriction both by our group and by collaborators. Films and nanowires have been shown to be largely polycrystalline, with magnetostrictions that are on the same order of magnitude as textured bulk Galfenol. Electrodeposited Galfenol films were made with epitaxial texture on GaAs. Galfenol nanowires have been made by electrodeposition into anodic aluminum oxide templates using similar parameters defined for films. Segmented nanowires of Galfenol/Cu have been made to provide engineered magnetic properties. Applications of Galfenol and other magnetic nanowires include microfluidic sensors, magnetic separation, cellular radio-frequency identification (RFID) tags, magnetic resonance imaging (MRI) contrast, and hyperthermia.
    Electronic ISSN: 1424-8220
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
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  • 8
    Publication Date: 2018-08-13
    Description: Sensors, Vol. 18, Pages 2644: Effects of the Ground Resolution and Thresholding on Crack Width Measurements Sensors doi: 10.3390/s18082644 Authors: Cho Yoon Jung When diagnosing the condition of a structure, it is necessary to measure the widths of any existing cracks in the structure. To ensure safety when relying on images of cracks, the selected imaging parameters and processing technology must be well understood. In this study, the effects of the ground sample distance and threshold values on the crack width measurement error are analyzed from a theoretical perspective. Here, the main source of such errors is assumed to be due to the mixed pixel phenomena in the left and right boundary pixels. Thus, a mathematical model is proposed in which the intensity changes in these pixels are computed via an equation. In addition, the relationship between the error and error probability distribution is represented with an equation based on the threshold values and mean error. Upon analysis, it was found that the threshold value that minimizes the error is at the mid-point between the background and foreground, and the probabilistic nature of the error indicates that it is theoretically possible to predict both the error and its probability distribution. The proposed model was validated using artificial images.
    Electronic ISSN: 1424-8220
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
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  • 9
    Publication Date: 2018-09-04
    Description: Sustainability, Vol. 10, Pages 3131: The Main Agroecological Structure (MAS) of the Agroecosystems: Concept, Methodology and Applications Sustainability doi: 10.3390/su10093131 Authors: Tomás Enrique León-Sicard Javier Toro Calderón Liven Fernando Martínez-Bernal José Alejandro Cleves-Leguízamo This document presents the concept of the Main Agroecological Structure of agroecosystems (MAS) from the perspective of environmental thinking (ecosystem-culture relationships) and considered as a dissipative cultural structure. It discusses the possible applications of this concept (resilience, production, diversity) both inside and outside the farms. The potential MAS can be useful in the planning processes of the farms because it allows the quantification of the internal and external corridors, including natural vegetation. At the same time, it can be an important tool in the context of landscape management because it shows a series of cultural relations (economic, social, symbolic and technological) that are normally overlooked by the partial analysis of landscape ecology.
    Electronic ISSN: 2071-1050
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 10
    Publication Date: 2018-09-04
    Description: Sustainability, Vol. 10, Pages 3130: Fraud, Economic versus Social-Psychological Losses, and Sustainable E-Auction Sustainability doi: 10.3390/su10093130 Authors: Xiaobing Zhang Fu-Sheng Tsai Chih-Chen Lin Ya-Fang Cheng Kun-Hwa Lu As compared to the economic losses, social and psychological losses are of equal importance in discussing the losses when encountering fraud. Taking advantage of a perspective paper form (i.e., free writing style with a mix of description, analysis, and comments) with in-depth discussions and well-developed propositions, we combine considerations from the knowledge gap, platform quality, and risk management to discuss the comparative seriousness of different fraud-caused losses. The conceptual model mainly articulates on a series of relationships among different degrees of knowledge gap, platform quality, and risk management in predicting the various combinative losses in the economic, social, and psychological aspects. Propositions follow. First, when the knowledge gap is higher, the economic losses of being cheated on the internet will be higher, while lower in social and psychological losses. Second, when perceived platform quality is higher, the economic losses of being cheated on the internet will be lower, while higher in social and psychological losses. Third, when platform risk management is better, all aspects of being cheated on the internet will be lower. Based on the assumption of network externality, we also argue that the multiple dimensions of fraud-caused losses may damage e-auction sustainability. Theoretical and practical implications will be discussed.
    Electronic ISSN: 2071-1050
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 11
    Publication Date: 2018-09-04
    Description: Symmetry, Vol. 10, Pages 379: Effective Blind Frequency Offset Estimation Scheme for BST-OFDM Based HDTV Broadcast Systems Symmetry doi: 10.3390/sym10090379 Authors: Yong-An Jung Young-Hwan You The integrated services digital broadcasting-terrestrial (ISDB-T) system is designed in order to accommodate high-quality video/audio and multimedia services, using band segmented transmission orthogonal frequency division multiplexing (BST-OFDM) scheme. In the ISDB-T system, the pilot configuration varies depending on whether a segment uses a coherent or differential modulation. Therefore, it is necessary to perform a joint estimation of carrier frequency offset (CFO) and sampling frequency offset (SFO) independent of the segment format in the ISDB-T system. The goal is to complete those synchronization tasks while considering an information-carrying transmission and multiplexing configuration control (TMCC) signal as pilot symbols. It is demonstrated through numerical simulations that the differential BPSK-modulated TMCC information can be efficiently used for a least-squares estimation of CFO and SFO, offering an acceptable performance.
    Electronic ISSN: 2073-8994
    Topics: Mathematics , Physics
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  • 12
    Publication Date: 2018-09-04
    Description: Water, Vol. 10, Pages 1179: The Influence of Groundwater on the Sliding and Deposition Behaviors of Cataclinal Slopes Water doi: 10.3390/w10091179 Authors: Cheng-Hsueh Weng Ming-Lang Lin Chia-Ming Lo Hsi-Hung Lin In 2015, Typhoon Soudelor caused a number of slopes to collapse in Wulai District of New Taipei City. One of these landslides took place in the village of Zhongzhi and involved atypical cataclinal slope failure with a rock–soil interface. The remaining rock in the slope and the rock that originally covered it contained vertical joints, so groundwater could have flowed through the joints and influenced landslide behavior. However, few existing studies have examined the influence of upward groundwater flow on slope stability. To fill this gap, this study used physical tests and discrete element method software to conduct relevant investigations. We first conducted tests using the ground water flow and cataclinal slope simulator, in which water can flow out of holes in the platform to simulate upward-seeping groundwater. We used gypsum boards or rhombus-shaped grinding stones to simulate rock with vertical joints and round grinding stones mixed in paste to simulate cohesive regolith. The objective of the tests was to understand the influence of water flow on the landslide behavior of the specimens and the connections between movement behavior and the sequence of sliding between different materials during the landslide. We then reproduced the physical tests using discrete element method software PFC3D (Particle Flow Code 3D Version 4.0 by Itasca, Minneapolis, MN, USA) to display the influence of water flow on specimens, including the weakening of bond strength, decreasing coefficient of friction between particles, and the application of seepage force, as well as uplift and lateral forces caused by water pressure. This process gave us an understanding of the influence of different groundwater conditions on landslide behavior, which facilitates the study of landslide mechanisms and movement behavior. Finally, we applied the water flow influence settings to simulate and examine the Zhongzhi landslide process. Compared to methods that simply reduce the friction coefficients to trigger landslides, our numerical simulation was closer to reality in that in this case a rising water table triggered the landslide.
    Electronic ISSN: 2073-4441
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 13
    Publication Date: 2018-09-04
    Description: Water, Vol. 10, Pages 1178: Recent Trends (2012–2016) of N, Si, and P Export from the Nemunas River Watershed: Loads, Unbalanced Stoichiometry, and Threats for Downstream Aquatic Ecosystems Water doi: 10.3390/w10091178 Authors: Irma Vybernaite-Lubiene Mindaugas Zilius Laura Saltyte-Vaisiauske Marco Bartoli The Curonian Lagoon, the largest in Europe, suffers from nuisance cyanobacterial blooms during summer, probably triggered by unbalanced nutrient availability. However, nutrient delivery to this system was never analysed in detail. During 2012–2016, we analysed the monthly discharge, nutrient loads, and ecological stoichiometry at the closing section of the Nemunas River, the main nutrient source to the lagoon. The aim of this study was to investigate seasonal and annual variations of nitrogen (N), silica (Si), and phosphorous (P) with respect to discharge, climatic features, and historical trends. The nutrient loads varied yearly by up to 50% and their concentrations underwent strong seasonality, with summer N and Si limitation. The river discharge (16 ± 4 km3·yr−1) was lower than the historical average (21.8 km3·yr−1). Changes in agricultural practices resulted in similar N export from the river watershed compared to historical data (1986–2002), while sewage treatment plant improvements led to a ~60% decrease of P loads. This work contributes new data to the scattered available information on the most important nutrient source to the Curonian Lagoon. Further P reduction is needed to avoid unbalanced dissolved inorganic nitrogen and phosphorus (DIN:DIP~10) ecological stoichiometry in summer, which may stimulate undesired cyanobacterial blooms.
    Electronic ISSN: 2073-4441
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 14
    Publication Date: 2018-09-04
    Description: Symmetry, Vol. 10, Pages 378: Applications of Differential Form Wu’s Method to Determine Symmetries of (Partial) Differential Equations Symmetry doi: 10.3390/sym10090378 Authors: Temuer Chaolu Sudao Bilige In this paper, we present an application of Wu’s method (differential characteristic set (dchar-set) algorithm) for computing the symmetry of (partial) differential equations (PDEs) that provides a direct and systematic procedure to obtain the classical and nonclassical symmetry of the differential equations. The fundamental theory and subalgorithms used in the proposed algorithm consist of a different version of the Lie criterion for the classical symmetry of PDEs and the zero decomposition algorithm of a differential polynomial (d-pol) system (DPS). The version of the Lie criterion yields determining equations (DTEs) of symmetries of differential equations, even those including a nonsolvable equation. The decomposition algorithm is used to solve the DTEs by decomposing the zero set of the DPS associated with the DTEs into a union of a series of zero sets of dchar-sets of the system, which leads to simplification of the computations.
    Electronic ISSN: 2073-8994
    Topics: Mathematics , Physics
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  • 15
    Publication Date: 2018-09-04
    Description: Symmetry, Vol. 10, Pages 377: The Absolute Ruin Insurance Risk Model with a Threshold Dividend Strategy Symmetry doi: 10.3390/sym10090377 Authors: Wenguang Yu Yujuan Huang Chaoran Cui The absolute ruin insurance risk model is modified by including some valuable market economic information factors, such as credit interest, debit interest and dividend payments. Such information is especially important for insurance companies to control risks. We further assume that the insurance company is able to finance and continue to operate when its reserve is negative. We investigate the integro-differential equations for some interest actuarial diagnostics. We also provide numerical examples to explain the effects of relevant parameters on actuarial diagnostics.
    Electronic ISSN: 2073-8994
    Topics: Mathematics , Physics
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  • 16
    Publication Date: 2018-09-04
    Description: Water, Vol. 10, Pages 1177: Investigating the Dynamic Influence of Hydrological Model Parameters on Runoff Simulation Using Sequential Uncertainty Fitting-2-Based Multilevel-Factorial-Analysis Method Water doi: 10.3390/w10091177 Authors: Shuai Zhou Yimin Wang Jianxia Chang Aijun Guo Ziyan Li Hydrological model parameters are generally considered to be simplified representations that characterize hydrologic processes. Therefore, their influence on runoff simulations varies with climate and catchment conditions. To investigate the influence, a three-step framework is proposed, i.e., a Latin hypercube sampling (LHS-OAT) method multivariate regression model is used to conduct parametric sensitivity analysis; then, the multilevel-factorial-analysis method is used to quantitatively evaluate the individual and interactive effects of parameters on the hydrologic model output. Finally, analysis of the reasons for dynamic parameter changes is performed. Results suggest that the difference in parameter sensitivity for different periods is significant. The soil bulk density (SOL_BD) is significant at all times, and the parameter Soil Convention Service (SCS) runoff curve number (CN2) is the strongest during the flood period, and the other parameters are weaker in different periods. The interaction effects of CN2 and SOL_BD, as well as effective hydraulic channel conditions (CH_K2) and SOL_BD, are obvious, indicating that soil bulk density can impact the amount of loss generated by surface runoff and river recharge to groundwater. These findings help produce the best parameter inputs and improve the applicability of the model.
    Electronic ISSN: 2073-4441
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 17
    Publication Date: 2018-08-14
    Description: Energies, Vol. 11, Pages 2107: Optimal P-Q Control of Grid-Connected Inverters in a Microgrid Based on Adaptive Population Extremal Optimization Energies doi: 10.3390/en11082107 Authors: Min-Rong Chen Huan Wang Guo-Qiang Zeng Yu-Xing Dai Da-Qiang Bi The optimal P-Q control issue of the active and reactive power for a microgrid in the grid-connected mode has attracted increasing interests recently. In this paper, an optimal active and reactive power control is developed for a three-phase grid-connected inverter in a microgrid by using an adaptive population-based extremal optimization algorithm (APEO). Firstly, the optimal P-Q control issue of grid-connected inverters in a microgrid is formulated as a constrained optimization problem, where six parameters of three decoupled PI controllers are real-coded as the decision variables, and the integral time absolute error (ITAE) between the output and referenced active power and the ITAE between the output and referenced reactive power are weighted as the objective function. Then, an effective and efficient APEO algorithm with an adaptive mutation operation is proposed for solving this constrained optimization problem. The simulation and experiments for a 3kW three-phase grid-connected inverter under both nominal and variable reference active power values have shown that the proposed APEO-based P-Q control method outperforms the traditional Z-N empirical method, the adaptive genetic algorithm-based, and particle swarm optimization-based P-Q control methods.
    Electronic ISSN: 1996-1073
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 18
    Publication Date: 2018-08-14
    Description: Energies, Vol. 11, Pages 2104: Online Energy Management and Heterogeneous Task Scheduling for Smart Communities with Residential Cogeneration and Renewable Energy Energies doi: 10.3390/en11082104 Authors: Yongsheng Cao Guanglin Zhang Demin Li Lin Wang Zongpeng Li With the development of renewable energy technology and communication technology in recent years, many residents now utilize renewable energy devices in their residences with energy storage systems. We have full confidence in the promising prospects of sharing idle energy with others in a community. However, it is a great challenge to share residents’ energy with others in a community to minimize the total cost of all residents. In this paper, we study the problem of energy management and task scheduling for a community with renewable energy and residential cogeneration, such as residential combined heat and power system (resCHP) to pay the least electricity bill. We take elastic and inelastic load demands into account which are delay intolerant and delay tolerant tasks in the community. The minimum cost problem of a non-cooperative community is extracted into a random non-convex optimization problem with some physical constraints. Our objective is to minimize the time-average cost for each resident in the community, including the cost of the external grid and natural gas. The Lyapunov optimization theory and a primal-dual gradient method are adopted to tackle this problem, which needs no future data and has low computational complexity. Furthermore, we design a cooperative renewable energy sharing algorithm based on State-action-reward-state-action (Sarsa) Algorithm, in the condition that each residence in the community is able to communicate with its neighbors by a central controller. Finally, extensive simulations are presented to validate the proposed algorithms by using practical data.
    Electronic ISSN: 1996-1073
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 19
    Publication Date: 2018-08-14
    Description: Energies, Vol. 11, Pages 2105: SOLIS—A Novel Decision Support Tool for the Assessment of Solar Radiation in ArcGIS Energies doi: 10.3390/en11082105 Authors: Jan K. Kazak Małgorzata Świąder The global Sustainable Development Goals influence the implementation of energy development strategies worldwide. However, in order to support local stakeholders in sustainable energy development strategies and climate change adaptation plans and the implementation of policies, there is a need to equip local decision makers with tools enabling the assessment of sustainable energy investments. In order to do so, the aim of this study is to create a novel tool for the assessment of solar radiation (SOLIS) in ArcGIS. The SOLIS tool builds on the existing ArcGIS algorithm by including input data conversion and post-processing of the results. This should expand the group of potential users of solar radiation analyses. The self-filtering tool excludes surfaces that are not suitable for solar energy investments due to geometrical reasons. The reduction of the size of the output data is positive for technical reasons (speed of the calculation and occupied storage place) and for cognitive reasons (reduction of the number of objects necessary to analyse by the user). The SOLIS tool limits the requirement for users to insert three-dimensional (3D) models of roofs (with any geometry) and select solar radiation calculation periods. The highlight of this research is to develop the decision support tool for the assessment of solar radiation, which would reduce the requirements for potential users, in order to promote indicator-based assessments among non-Geographical Information Systems (GIS) specialists.
    Electronic ISSN: 1996-1073
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 20
    Publication Date: 2018-08-14
    Description: Energies, Vol. 11, Pages 2103: A Study on the Fuel Economy Potential of Parallel and Power Split Type Hybrid Electric Vehicles Energies doi: 10.3390/en11082103 Authors: Hyunhwa Kim Junbeom Wi Jiho Yoo Hanho Son Chiman Park Hyunsoo Kim What is the best number of gear steps for parallel type hybrid electric vehicles (HEVs) and what are the pros and cons of the power split type HEV compared to the parallel type have been interesting issues in the development of HEVs. In this study, a comparative analysis was performed to evaluate the fuel economy potential of a parallel HEV and a power split type HEV. First, the fuel economy potential of the parallel HEV was investigated for the number of gear steps. Four-speed, six-speed, and eight-speed automatic transmissions (ATs) and a continuously variable transmission (CVT) were selected, and their drivetrain losses were considered in the dynamic programming (DP). It was found from DP results that the power electronics system (PE) loss decreased because the magnitude of the motor load leveling power decreased as the number of gear steps increased. On the other hand, the drivetrain losses including the electric oil pump (EOP) loss increased with increasing gear step. The improvement rate from the 4-speed to the 6-speed was the greatest, while it decreased for the higher gear step. The fuel economy of the CVT HEV was rather low due to the large EOP loss in spite of the reduced PE loss. In addition, the powertrain characteristics of the parallel HEV were compared with the power split type HEV. In the power split type HEV, the PE loss was almost double compared to that of the parallel HEV because two large capacity motor-generators were used. However, the drivetrain loss and EOP loss of the power split type HEV were found to be much smaller due to its relatively simple architecture. It is expected that the power characteristics of the parallel and power split type HEVs obtained from the DP results can be used in the development of HEV systems.
    Electronic ISSN: 1996-1073
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 21
    Publication Date: 2018-08-14
    Description: Energies, Vol. 11, Pages 2102: Electromechanical Transient Modeling of Line Commutated Converter-Modular Multilevel Converter-Based Hybrid Multi-Terminal High Voltage Direct Current Transmission Systems Energies doi: 10.3390/en11082102 Authors: Liang Xiao Yan Li Huangqing Xiao Zheren Zhang Zheng Xu A method for electromechanical modeling of line commutated converter (LCC)-modular multilevel converter (MMC)-based hybrid multi-terminal High Voltage Direct Current Transmission (HVDC) systems for large-scale power system transient stability study is proposed. Firstly, the general idea of modeling the LCC-MMC hybrid multi-terminal HVDC system is presented, then the AC-side and DC-side models of the LCC/MMC are established. Different from the conventional first-order DC-side model of the MMC, an improved second-order DC-side model of the MMC is established. Besides considering the firing angle limit of the LCC, a sequential power flow algorithm is proposed for the initialization of LCC-MMC hybrid multi-terminal HVDC system. Lastly, simulations of small scale and large scale power systems embedded with a three-terminal LCC-MMC hybrid HVDC system are performed on the electromechanical simulation platform PSS/E. It is demonstrated that if the firing angle limit is not considered, the accuracy of the power flow solutions will be greatly affected. Steady state calculation and dynamic simulation show that the developed LCC-MMC hybrid MTDC model is accurate enough for electromechanical transient stability studies of large-scale AC/DC system.
    Electronic ISSN: 1996-1073
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 22
    Publication Date: 2018-08-14
    Description: Energies, Vol. 11, Pages 2100: A Novel Computational Approach for Harmonic Mitigation in PV Systems with Single-Phase Five-Level CHBMI Energies doi: 10.3390/en11082100 Authors: Rosario Miceli Giuseppe Schettino Fabio Viola In this paper, a novel approach to low order harmonic mitigation in fundamental switching frequency modulation is proposed for high power photovoltaic (PV) applications, without trying to solve the cumbersome non-linear transcendental equations. The proposed method allows for mitigation of the first-five harmonics (third, fifth, seventh, ninth, and eleventh harmonics), to reduce the complexity of the required procedure and to allocate few computational resource in the Field Programmable Gate Array (FPGA) based control board. Therefore, the voltage waveform taken into account is different respect traditional voltage waveform. The same concept, known as “voltage cancelation”, used for single-phase cascaded H-bridge inverters, has been applied at a single-phase five-level cascaded H-bridge multilevel inverter (CHBMI). Through a very basic methodology, the polynomial equations that drive the control angles were detected for a single-phase five-level CHBMI. The acquired polynomial equations were implemented in a digital system to real-time operation. The paper presents the preliminary analysis in simulation environment and its experimental validation.
    Electronic ISSN: 1996-1073
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 23
    Publication Date: 2018-08-14
    Description: Energies, Vol. 11, Pages 2098: Analysis of Shallow Subsurface Geological Structures and Ground Effective Thermal Conductivity for the Evaluation of Ground-Source Heat Pump System Installation in the Aizu Basin, Northeast Japan Energies doi: 10.3390/en11082098 Authors: Takeshi Ishihara Gaurav Shrestha Shohei Kaneko Youhei Uchida Shallow subsurface geological structure mapping combined with ground effective thermal conductivity values at the basin scale provide an appropriate method to evaluate the installation potential of ground-source heat pump systems. This study analyzed the geological structure of the Aizu Basin (Northeast Japan) using sedimentary cores and boring log and mapped the distribution of average ground effective thermal conductivity in the range from −10 m to −100 m depth calculated from cores and logs. Gravel layers dominate in alluvial fans of the northern and southern basin areas, which are found to be associated with higher average ground effective thermal conductivity values, 1.3–1.4 W/m/K, while central and western floodplain areas show lower values of 1.0–1.3 W/m/K due to the existence of thick mud layers in the shallow subsurface. The results indicate that the conventional closed-loop systems are more feasible in northern and southern basin areas than in the central and western areas. Evaluation for the installation potential of the ground-source heat pump systems using depth-based distribution maps of average ground effective thermal conductivity is the originality of this study. This approach is valuable and proper for the simple assessment of the system installation in different sedimentary plains and basins in Japan and other countries.
    Electronic ISSN: 1996-1073
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 24
    Publication Date: 2018-08-14
    Description: Energies, Vol. 11, Pages 2097: Prediction of Wave Power Generation Using a Convolutional Neural Network with Multiple Inputs Energies doi: 10.3390/en11082097 Authors: Chenhua Ni Xiandong Ma Successful development of a marine wave energy converter (WEC) relies strongly on the development of the power generation device, which needs to be efficient and cost-effective. An innovative multi-input approach based on the Convolutional Neural Network (CNN) is investigated to predict the power generation of a WEC system using a double-buoy oscillating body device (OBD). The results from the experimental data show that the proposed multi-input CNN performs much better at predicting results compared with the conventional artificial network and regression models. Through the power generation analysis of this double-buoy OBD, it shows that the power output has a positive correlation with the wave height when it is higher than 0.2 m, which becomes even stronger if the wave height is higher than 0.6 m. Furthermore, the proposed approach associated with the CNN algorithm in this study can potentially detect the changes that could be due to presence of anomalies and therefore be used for condition monitoring and fault diagnosis of marine energy converters. The results are also able to facilitate controlling of the electricity balance among energy conversion, wave power produced and storage.
    Electronic ISSN: 1996-1073
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 25
    Publication Date: 2018-08-14
    Description: Entropy, Vol. 20, Pages 600: Identity Vector Extraction by Perceptual Wavelet Packet Entropy and Convolutional Neural Network for Voice Authentication Entropy doi: 10.3390/e20080600 Authors: Lei Lei Kun She Recently, the accuracy of voice authentication system has increased significantly due to the successful application of the identity vector (i-vector) model. This paper proposes a new method for i-vector extraction. In the method, a perceptual wavelet packet transform (PWPT) is designed to convert speech utterances into wavelet entropy feature vectors, and a Convolutional Neural Network (CNN) is designed to estimate the frame posteriors of the wavelet entropy feature vectors. In the end, i-vector is extracted based on those frame posteriors. TIMIT and VoxCeleb speech corpus are used for experiments and the experimental results show that the proposed method can extract appropriate i-vector which reduces the equal error rate (EER) and improve the accuracy of voice authentication system in clean and noisy environment.
    Electronic ISSN: 1099-4300
    Topics: Chemistry and Pharmacology , Physics
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  • 26
    Publication Date: 2018-08-14
    Description: Entropy, Vol. 20, Pages 601: A Maximum-Entropy Method to Estimate Discrete Distributions from Samples Ensuring Nonzero Probabilities Entropy doi: 10.3390/e20080601 Authors: Paul Darscheid Anneli Guthke Uwe Ehret When constructing discrete (binned) distributions from samples of a data set, applications exist where it is desirable to assure that all bins of the sample distribution have nonzero probability. For example, if the sample distribution is part of a predictive model for which we require returning a response for the entire codomain, or if we use Kullback–Leibler divergence to measure the (dis-)agreement of the sample distribution and the original distribution of the variable, which, in the described case, is inconveniently infinite. Several sample-based distribution estimators exist which assure nonzero bin probability, such as adding one counter to each zero-probability bin of the sample histogram, adding a small probability to the sample pdf, smoothing methods such as Kernel-density smoothing, or Bayesian approaches based on the Dirichlet and Multinomial distribution. Here, we suggest and test an approach based on the Clopper–Pearson method, which makes use of the binominal distribution. Based on the sample distribution, confidence intervals for bin-occupation probability are calculated. The mean of each confidence interval is a strictly positive estimator of the true bin-occupation probability and is convergent with increasing sample size. For small samples, it converges towards a uniform distribution, i.e., the method effectively applies a maximum entropy approach. We apply this nonzero method and four alternative sample-based distribution estimators to a range of typical distributions (uniform, Dirac, normal, multimodal, and irregular) and measure the effect with Kullback–Leibler divergence. While the performance of each method strongly depends on the distribution type it is applied to, on average, and especially for small sample sizes, the nonzero, the simple “add one counter”, and the Bayesian Dirichlet-multinomial model show very similar behavior and perform best. We conclude that, when estimating distributions without an a priori idea of their shape, applying one of these methods is favorable.
    Electronic ISSN: 1099-4300
    Topics: Chemistry and Pharmacology , Physics
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  • 27
    Publication Date: 2018-08-14
    Description: Entropy, Vol. 20, Pages 603: Symmetry, Outer Bounds, and Code Constructions: A Computer-Aided Investigation on the Fundamental Limits of Caching Entropy doi: 10.3390/e20080603 Authors: Chao Tian We illustrate how computer-aided methods can be used to investigate the fundamental limits of the caching systems, which are significantly different from the conventional analytical approach usually seen in the information theory literature. The linear programming (LP) outer bound of the entropy space serves as the starting point of this approach; however, our effort goes significantly beyond using it to prove information inequalities. We first identify and formalize the symmetry structure in the problem, which enables us to show the existence of optimal symmetric solutions. A symmetry-reduced linear program is then used to identify the boundary of the memory-transmission-rate tradeoff for several small cases, for which we obtain a set of tight outer bounds. General hypotheses on the optimal tradeoff region are formed from these computed data, which are then analytically proven. This leads to a complete characterization of the optimal tradeoff for systems with only two users, and certain partial characterization for systems with only two files. Next, we show that by carefully analyzing the joint entropy structure of the outer bounds for certain cases, a novel code construction can be reverse-engineered, which eventually leads to a general class of codes. Finally, we show that outer bounds can be computed through strategically relaxing the LP in different ways, which can be used to explore the problem computationally. This allows us firstly to deduce generic characteristic of the converse proof, and secondly to compute outer bounds for larger problem cases, despite the seemingly impossible computation scale.
    Electronic ISSN: 1099-4300
    Topics: Chemistry and Pharmacology , Physics
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  • 28
    Publication Date: 2018-08-14
    Description: Forests, Vol. 9, Pages 493: Spatio-Temporal Dynamic Architecture of Living Brush Mattress: Root System and Soil Shear Strength in Riverbanks Forests doi: 10.3390/f9080493 Authors: Dong Zhang Jinhua Cheng Ying Liu Hongjiang Zhang Lan Ma Xuemei Mei Yihui Sun As a basal measure of soil bioengineering, the living brush mattress has been widely applied in riparian ecological protection forest construction. The living brush mattress shows favorable protective effects on riverbanks. However, there are few reports on the root structure and the soil strengthening benefit of the living brush mattress. The present work reports a series of experiments on root morphology and soil shear strength enhancement at the temporal and spatial scales. The object of the study is 24 living brush mattress trees constructed with Salix alba L. ‘Tristis’ (LBS hereafter). Traditional root morphology and mechanical measurement methods were used to collect the parameters. The results showed that the root systems of LBS had the characteristics of symmetry and upslope growth. The roots were mainly distributed in a cylindrical region of the soil (radius × thickness: 0.4 m × 0.5 m) and their biomass increased with different growth rates for the periods from 1 to 5 and from 5 to 7 years. Both age and slope position were factors that influence root growth. The root diameter falls within 0–5 mm, has a significant effect on the soil shear strength and provides a conical-shape potentiation zone to ensure the efficient protection of a riverbank. The results of this study demonstrate that LBS is an efficient and feasible engineering measure in the field of riverbank protection.
    Electronic ISSN: 1999-4907
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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  • 29
    Publication Date: 2018-09-04
    Description: Materials, Vol. 11, Pages 1595: An Analytical Study of Electromagnetic Deep Penetration Conditions and Implications in Lossy Media through Inhomogeneous Waves Materials doi: 10.3390/ma11091595 Authors: Paolo Baccarelli Fabrizio Frezza Patrizio Simeoni Nicola Tedeschi This paper illustrates how the penetration of electromagnetic waves in lossy media strongly depends on the waveform and not only on the media involved. In particular, the so-called inhomogeneous plane waves are compared against homogeneous plane waves illustrating how the first ones can generate deep penetration effects. Moreover, the paper provides examples showing how such waves may be practically generated. The approach taken here is analytical and it concentrates on the deep penetration conditions obtained by means of incident inhomogeneous plane waves incoming from a lossless medium and impinging on a lossy medium. Both conditions and constraints that the waveforms need to possess to achieve deep penetration are analysed. Some results are finally validated through numerical computations. The theory presented here is of interest in view of a practical implementation of the deep penetration effect.
    Electronic ISSN: 1996-1944
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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  • 30
    Publication Date: 2018-09-04
    Description: Materials, Vol. 11, Pages 1593: Study on Formation Process and Models of Linear Fe Cluster Structure on a Si(111)-7 × 7-CH3OH Surface Materials doi: 10.3390/ma11091593 Authors: Wenxin Li Wanyu Ding Dongying Ju Ken-ichi Tanaka Fumio Komori STM results showed that Fe atoms were deposited on a Si(111)-7 × 7 reconstructed surface, which was saturated with CH3OH molecules. Fe atomic linear structure was composed of stable clusters and in-situ observed by the scanning tunneling microscopy (STM). The aim to improve its application of magnetic memory material, both formation process and models, has been explored in this paper. By combining surface images and mass spectrometer data, an intermediate layer model was established. In terms of thermal stability, the most favorable adsorption sites of CH3OH were further explored. After that, Fe atoms were deposited on the Si(111)-7 × 7-CH3OH surface, forming a linear cluster structure. On the one hand, a new Fe cluster model was put forward in this paper, which was established with height measurement and 3D surface display technology. This model is also affected by the evaporation temperature, which can be consistent with the atomic stacking pattern of face centered cubic structures. On the other hand, the slight height change suggested the stability of linear structures. Even in the condition of thin air introduction, Fe cluster showed a good performance, which suggested the possibility of magnetic memory application in the future. These investigations are believed to have, to a certain extent, increased the probability of forming Fe linear clusters on the surface of silicon substrate, especially according to the models and surface technology we adjusted.
    Electronic ISSN: 1996-1944
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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  • 31
    Publication Date: 2018-09-04
    Description: Minerals, Vol. 8, Pages 381: Effects of Superplasticizer on the Hydration, Consistency, and Strength Development of Cemented Paste Backfill Minerals doi: 10.3390/min8090381 Authors: Jian Zhang Hongwei Deng Abbas Taheri Junren Deng Bo Ke The strength and consistency of cemented paste backfill (CPB) are of key concerns in the stope stability and cost control for underground mines. It is common practice to use additives, such as superplasticizer, to improve the performance of CPB. This study mainly focuses on the effects of superplasticizer on the hydration, consistency, and strength of CPB. In this study, a polynaphtalene sulfonate was used as the superplasticizer. The binder is a mix of 33.3% ordinary Portland cement and 66.7% fly ash. The CPB specimens with a tailings-binder ratio of 3:1 and a solid concentration of 70% were then tested by a low field nuclear magnetic resonance system after different hydration times. Effects of polynaphtalene sulfonate on the hydration, fluidity, and strength were investigated. Results showed that the polynaphtalene sulfonate has a strong influence on short-duration hydration, which may contribute to the strength increase of CPB. It has been demonstrated that the polynaphtalene sulfonate improved the fluidity of the CPB mixture. With the increased dosage of polynaphtalene sulfonate, the slump increased. It was also found that the polynaphtalene sulfonate dosage has a negligible effect on the 1 day (d) strength while it has a strengthening effect on the 7 d, 14 d, and 28 d strength of CPB specimens.
    Electronic ISSN: 2075-163X
    Topics: Geosciences
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  • 32
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    American Physical Society (APS)
    Publication Date: 2018-08-14
    Description: Author(s): L. Jin We investigate the scattering properties of a parity-time-antisymmetric non-Hermitian system. The parity-time-antisymmetric scattering center possesses imaginary nearest-neighbor hoppings and real on-site potentials; it has been experimentally realized through dissipative coupling and frequency detu... [Phys. Rev. A 98, 022117] Published Mon Aug 13, 2018
    Keywords: Fundamental concepts
    Print ISSN: 1050-2947
    Electronic ISSN: 1094-1622
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  • 33
    Publication Date: 2018-08-14
    Description: Author(s): Kwangil Bae and Wonmin Son The most general class of nonlocality criteria for N -partite d -chotomic systems with k number of measurement settings is derived under the constraint of measurement symmetries. It is the complete characterization of the multipartite nonlocality when the correlation is assumed to be symmetric under t... [Phys. Rev. A 98, 022116] Published Mon Aug 13, 2018
    Keywords: Fundamental concepts
    Print ISSN: 1050-2947
    Electronic ISSN: 1094-1622
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  • 34
    Publication Date: 2018-08-14
    Description: Author(s): Xingze Qiu, Tian-Shu Deng, Guang-Can Guo, and Wei Yi We show that dynamical quantum phase transitions (DQPTs) in the quench dynamics of two-dimensional topological systems can be characterized by a dynamical topological invariant defined along an appropriately chosen closed contour in momentum space. Such a dynamical topological invariant reflects the... [Phys. Rev. A 98, 021601(R)] Published Mon Aug 13, 2018
    Keywords: Matter waves and collective properties of cold atoms and molecules
    Print ISSN: 1050-2947
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  • 35
    Publication Date: 2018-08-14
    Description: Author(s): Ulf Leonhardt, Itay Griniasty, Sander Wildeman, Emmanuel Fort, and Mathias Fink In the Unruh effect an observer with constant acceleration perceives the quantum vacuum as thermal radiation. The Unruh effect has been believed to be a pure quantum phenomenon, but here we show theoretically how the effect arises from the correlation of noise, regardless of whether this noise is qu... [Phys. Rev. A 98, 022118] Published Mon Aug 13, 2018
    Keywords: Fundamental concepts
    Print ISSN: 1050-2947
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  • 36
    Publication Date: 2018-08-14
    Description: Author(s): Xi-Bin Li, Yang-Yang Wang, He Wang, and Jian-Yang Zhu We study and analyze the dynamic properties of both canonical and noncanonical warm inflationary models with dissipative effects. We consider different models of canonical warm inflation with different dissipative coefficients and prove that the behavior at infinity of the quadratic dissipative mode... [Phys. Rev. D 98, 043510] Published Mon Aug 13, 2018
    Keywords: Cosmology
    Print ISSN: 0556-2821
    Electronic ISSN: 1089-4918
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  • 37
    Publication Date: 2018-08-14
    Description: Author(s): Hong-Ming Zhu, Ue-Li Pen, Yu Yu, and Xuelei Chen 21 cm intensity mapping has emerged as a promising technique to map the large-scale structure of the Universe, at redshifts z from 1 to 10. Unfortunately, many of the key cross-correlations with the cosmic microwave background and photo- z galaxies have been thought to be impossible due to the foregr... [Phys. Rev. D 98, 043511] Published Mon Aug 13, 2018
    Keywords: Cosmology
    Print ISSN: 0556-2821
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  • 38
    Publication Date: 2018-08-14
    Description: Author(s): Jan Veltmaat, Jens C. Niemeyer, and Bodo Schwabe We simulate the formation and evolution of ultralight bosonic dark matter halos from cosmological initial conditions. Using zoom-in techniques, we are able to resolve the detailed interior structure of the halos. We observe the formation of solitonic cores and confirm the core-halo mass relation pre... [Phys. Rev. D 98, 043509] Published Mon Aug 13, 2018
    Keywords: Cosmology
    Print ISSN: 0556-2821
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  • 39
    Publication Date: 2018-08-14
    Description: Author(s): Xi-Long Fan and Yanbei Chen Although spinning black holes are shown to be stable in vacuum in general relativity, exotic mechanisms have been speculated to convert the spin energy of black holes into gravitational waves. Such waves may be very weak in amplitude, since the spin-down could take a long time, therefore a direct se... [Phys. Rev. D 98, 044020] Published Mon Aug 13, 2018
    Keywords: General relativity, alternative theories of gravity
    Print ISSN: 0556-2821
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  • 40
    Publication Date: 2018-08-14
    Description: Author(s): Zhi Xiao In this paper, we obtain a nonrelativistic Hamiltonian from the Lorentz-violating (LV) scalar Lagrangian in the minimal standard model extension (SME). The Hamiltonian is obtained by two different methods. One is through the usual ansatz Φ ( t , r → ) = e − i m t Ψ ( t , r → ) applied to the LV-corrected Klein-Gordon ... [Phys. Rev. D 98, 035018] Published Mon Aug 13, 2018
    Keywords: Beyond the standard model
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  • 41
    Publication Date: 2018-08-14
    Description: Author(s): Dominic Beck, Giulio Fabbian, and Josquin Errard The study of the cosmic microwave background (CMB) lensing potential has established itself by now as a robust way of probing the physics of large-scale structure growth. The most common estimators of the lensing potential are derived under the assumption of Gaussianity of the matter distribution an... [Phys. Rev. D 98, 043512] Published Mon Aug 13, 2018
    Keywords: Cosmology
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  • 42
    Publication Date: 2018-08-14
    Description: Author(s): C. Deaconu, A. G. Vieregg, S. A. Wissel, J. Bowen, S. Chipman, A. Gupta, C. Miki, R. J. Nichol, and D. Saltzberg We present measurements of radio transmission in the ∼ 100     MHz range through a ∼ 100     m deep region below the surface of the ice at Summit Station, Greenland, called the firn. In the firn, the index of refraction changes due to the transition from snow at the surface to glacial ice below, affecting t... [Phys. Rev. D 98, 043010] Published Mon Aug 13, 2018
    Keywords: Astrophysics and astroparticle physics
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  • 43
    Publication Date: 2018-08-14
    Description: Author(s): Steven S. Gubser, Christian Jepsen, Ziming Ji, and Brian Trundy We exhibit simple lattice systems, motivated by recently proposed cold atom experiments, whose continuum limits interpolate between real and p -adic smoothness as a spectral exponent is varied. A real spatial dimension emerges in the continuum limit if the spectral exponent is negative, while a p -adi... [Phys. Rev. D 98, 045009] Published Mon Aug 13, 2018
    Keywords: Formal aspects of field theory, field theory in curved space
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  • 44
    Publication Date: 2018-08-14
    Description: Author(s): Katsuki Aoki, Chunshan Lin, and Shinji Mukohyama We study canonical transformations of general relativity (GR) to provide a novel matter coupling to gravity. Although the transformed theory is equivalent to GR in vacuum, the equivalence no longer holds if a matter field minimally couples to the canonically transformed gravitational field. We find ... [Phys. Rev. D 98, 044022] Published Mon Aug 13, 2018
    Keywords: General relativity, alternative theories of gravity
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  • 45
    Publication Date: 2018-08-14
    Description: Author(s): L. Zheng, E. C. Aschenauer, J. H. Lee, Bo-Wen Xiao, and Zhong-Bao Yin In this work, we present a systematic study on the feasibility of probing the largely unexplored transverse-momentum-dependent gluon Sivers function (GSF) in open charm production, and high- p T charged dihadron and dijet production at a future high-energy, high-luminosity electron-ion collider (EIC).... [Phys. Rev. D 98, 034011] Published Mon Aug 13, 2018
    Keywords: Strong Interactions
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  • 46
    Publication Date: 2018-08-14
    Description: Author(s): Xin Gao, Pramod Shukla, and Rui Sun We study the four-dimensional (4D) scalar potential arising from a generalized type IIA flux superpotential including the (non)geometric fluxes. First, we show that using a set of peculiar flux combinations, the 4D scalar potential can be formulated into a very compact form. This is what we call the... [Phys. Rev. D 98, 046009] Published Mon Aug 13, 2018
    Keywords: String theory, quantum gravity, gauge/gravity duality
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  • 47
    Publication Date: 2018-08-14
    Description: Author(s): Alex Giacomini, Marcela Lagos, Julio Oliva, and Aldo Vera It is well known that the Reissner-Norstrom solution of Einstein-Maxwell theory cannot be cylindrically extended to a higher dimension, as with the black hole solutions in vacuum. In this paper we show that this result is circumvented in Lovelock gravity. We prove that the theory containing only the... [Phys. Rev. D 98, 044019] Published Mon Aug 13, 2018
    Keywords: General relativity, alternative theories of gravity
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  • 48
    Publication Date: 2018-08-14
    Description: Author(s): Jeremías Aguilera-Damia, Alberto Faraggi, Leopoldo A. Pando Zayas, Vimal Rathee, and Guillermo A. Silva Using ζ -function regularization, we study the one-loop effective action of fundamental strings in A d S 5 × S 5 dual to the latitude 1 4 -BPS Wilson loop in N = 4 super-Yang-Mills theory. To avoid certain ambiguities inherent to string theory on curved backgrounds we subtract the effective action of the holog... [Phys. Rev. D 98, 046011] Published Mon Aug 13, 2018
    Keywords: String theory, quantum gravity, gauge/gravity duality
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  • 49
    Publication Date: 2018-08-14
    Description: Author(s): Arash Azizi and C. N. Pope The dimensional reduction of a generic theory on a curved internal space such as a sphere does not admit a consistent truncation to a finite set of fields that includes the Yang-Mills gauge bosons of the isometry group. In rare cases, e.g., the S 7 reduction of 11-dimensional supergravity, such a con... [Phys. Rev. D 98, 046010] Published Mon Aug 13, 2018
    Keywords: String theory, quantum gravity, gauge/gravity duality
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  • 50
    Publication Date: 2018-08-14
    Description: Author(s): Juho Lankinen and Iiro Vilja The lack of energy conservation introduces new particle processes in curved spacetime that are forbidden in flat space. Therefore, one has to be very cautious about using the results calculated in Minkowskian space in early Universe applications. This is true for particle decay rates in particular, ... [Phys. Rev. D 98, 045010] Published Mon Aug 13, 2018
    Keywords: Formal aspects of field theory, field theory in curved space
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  • 51
    Publication Date: 2018-08-14
    Description: Author(s): Silvia N. Santalla and Silvio C. Ferreira We investigate an off-lattice Eden model where the growth of new cells is performed with a probability dependent on the availability of resources coming externally towards the growing aggregate. The concentration of nutrients necessary for replication is assumed to be proportional to the voids conne... [Phys. Rev. E 98, 022405] Published Mon Aug 13, 2018
    Keywords: Biological Physics
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  • 52
    Publication Date: 2018-08-14
    Description: Author(s): Sergey V. Grishin, Boris S. Dmitriev, Olga I. Moskalenko, Valentin N. Skorokhodov, and Yurii P. Sharaevskii A self-generation of chaotic dissipative spin-wave multisoliton complexes has been observed experimentally. Localized in time, these patterns are formed in a passively Q-switched and mode-locked magnetic film feedback ring due to the competing three- and four-wave nonlinear spin-wave interactions. S... [Phys. Rev. E 98, 022209] Published Mon Aug 13, 2018
    Keywords: Nonlinear Dynamics and Chaos
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  • 53
    Publication Date: 2018-08-14
    Description: Author(s): V. E. Zakhvataev There is rapidly increasing evidence that nanoscale temperature heterogeneities are involved in important biological processes. Combining nanoheating and nanoscale thermosensors forms the basis of emerging unique methods of cell therapy, tissue engineering, and regenerative medicine. Understanding c... [Phys. Rev. E 98, 022404] Published Mon Aug 13, 2018
    Keywords: Biological Physics
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  • 54
    Publication Date: 2018-08-14
    Description: Author(s): F. Tajik, M. Sedighi, A. A. Masoudi, H. Waalkens, and G. Palasantzas We investigate the influence of Casimir and electrostatic torques on double-beam torsional microelectromechanical systems with materials covering a broad range of conductivities of more than three orders of magnitude. For the frictionless autonomous systems, bifurcation and phase space analysis show... [Phys. Rev. E 98, 022210] Published Mon Aug 13, 2018
    Keywords: Nonlinear Dynamics and Chaos
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  • 55
    Publication Date: 2018-08-14
    Description: Author(s): Bert O. Baumgaertner, Peter A. Fetros, Stephen M. Krone, and Rebecca C. Tyson Spatially situated opinions that can be held with different degrees of conviction lead to spatiotemporal patterns such as clustering (homophily), polarization, and deadlock. Our goal is to understand how sensitive these patterns are to changes in the local nature of interactions. We introduce two di... [Phys. Rev. E 98, 022310] Published Mon Aug 13, 2018
    Keywords: Networks and Complex Systems
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  • 56
    Publication Date: 2018-08-14
    Description: Author(s): Gloria Cecchini and Björn Schelter When the network is reconstructed, two types of errors can occur: false positive and false negative errors about the presence or absence of links. In this paper, the influence of these two errors on the vertex degree distribution is analytically analyzed. Moreover, an analytic formula of the density... [Phys. Rev. E 98, 022311] Published Mon Aug 13, 2018
    Keywords: Networks and Complex Systems
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  • 57
    Publication Date: 2018-08-14
    Description: Author(s): Clara Abaurrea Velasco, Masoud Abkenar, Gerhard Gompper, and Thorsten Auth Active agents—like phoretic particles, bacteria, sperm, and cytoskeletal filaments in motility assays—show a large variety of motility-induced collective behaviors, such as aggregation, clustering, and phase separation. The behavior of dense suspensions of engineered phoretic particles and of bacter... [Phys. Rev. E 98, 022605] Published Mon Aug 13, 2018
    Keywords: Colloids, Complex Fluids, and Active Matter
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  • 58
    Publication Date: 2018-08-14
    Description: Author(s): Balachandra Suri, Jeffrey Tithof, Roman O. Grigoriev, and Michael F. Schatz Recent studies suggest that unstable, nonchaotic solutions of the Navier-Stokes equation may provide deep insights into fluid turbulence. In this article, we present a combined experimental and numerical study exploring the dynamical role of unstable equilibrium solutions and their invariant manifol... [Phys. Rev. E 98, 023105] Published Mon Aug 13, 2018
    Keywords: Fluid Dynamics
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  • 59
    Publication Date: 2018-08-14
    Description: Author(s): B. Dinesh and S. Pushpavanam The effect of a soluble surfactant on the linear stability of layered two-phase Poiseuille flows through soft-gel-coated parallel walls is studied in this paper. The focus is on determining the effect of the elastohydrodynamic coupling between the fluids and the soft-gel layers on the various flow i... [Phys. Rev. E 98, 023106] Published Mon Aug 13, 2018
    Keywords: Fluid Dynamics
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  • 60
    Publication Date: 2018-08-14
    Description: Author(s): Omid Reza Mohammadipour, Sauro Succi, and Hamid Niazmand The aim of this study is to introduce a general approach to implement curved boundaries in lattice Boltzmann simulations. The main idea is to determine boundary values by extrapolating macroscopic properties from some reference points inside the computational domain. The introduced approach is based... [Phys. Rev. E 98, 023304] Published Mon Aug 13, 2018
    Keywords: Computational Physics
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  • 61
    Publication Date: 2018-08-14
    Description: Author(s): Anatoly A. Svidzinsky, Jonathan S. Ben-Benjamin, Stephen A. Fulling, and Don N. Page We find that uniformly accelerated motion of a mirror yields excitation of a static two-level atom with simultaneous emission of a real photon. This occurs because of virtual transitions with probability governed by the Planck factor involving the photon frequency ν and the Unruh temperature. The re... [Phys. Rev. Lett. 121, 071301] Published Mon Aug 13, 2018
    Keywords: Gravitation and Astrophysics
    Print ISSN: 0031-9007
    Electronic ISSN: 1079-7114
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  • 62
    Publication Date: 2018-08-14
    Description: Author(s): Yoshiyuki Tagawa and Ivo R. Peters The collapse of a vapor bubble in a corner generates a jet whose direction depends on the corner opening angle and bubble position. Experimental data is found to agree well with a potential flow model that gives analytical solutions for a family of corner opening angles. [Phys. Rev. Fluids 3, 081601(R)] Published Mon Aug 13, 2018
    Keywords: Drops, Bubbles, Capsules, and Vesicles
    Electronic ISSN: 2469-990X
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  • 63
    Publication Date: 2018-08-14
    Description: Author(s): B. Cheng, T. J. T. Kwan, S. A. Yi, O. L. Landen, Y. M. Wang, C. J. Cerjan, S. H. Batha, and F. J. Wysocki Asymmetric implosion of inertial confinement fusion capsules is known, both experimentally and computationally, to reduce thermonuclear performance. This work shows that low-mode asymmetries degrade performance as a result of a decrease in the hydrodynamic disassembly time of the hot-spot core, whic... [Phys. Rev. E 98, 023203] Published Mon Aug 13, 2018
    Keywords: Plasma Physics
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  • 64
    Publication Date: 2018-08-14
    Description: Author(s): Chi Peng, Shouceng Tian, Gensheng Li, and Michael C. Sukop This work serves as an important extension of previous work on cavitation simulation [Sukop and Or, Phys. Rev. E 71 , 046703 (2005) ]. A modified Shan-Chen single-component multiphase lattice Boltzmann method is used to simulate two different heterogeneous cavitation nucleation mechanisms, the free ga... [Phys. Rev. E 98, 023305] Published Mon Aug 13, 2018
    Keywords: Computational Physics
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  • 65
    Publication Date: 2018-08-14
    Description: Author(s): F. A. S. Barbosa, A. S. Coelho, L. F. Muñoz-Martínez, L. Ortiz-Gutiérrez, A. S. Villar, P. Nussenzveig, and M. Martinelli Researchers have entangled six modes of a laser cavity—a record number for such a device. [Phys. Rev. Lett. 121, 073601] Published Mon Aug 13, 2018
    Keywords: Atomic, Molecular, and Optical Physics
    Print ISSN: 0031-9007
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  • 66
    Publication Date: 2018-08-14
    Description: Author(s): Konstantin Clauß, Martin J. Körber, Arnd Bäcker, and Roland Ketzmerick A hypothesis about the average phase-space distribution of resonance eigenfunctions in chaotic systems with escape through an opening is proposed. Eigenfunctions with decay rate γ are described by a classical measure that (i) is conditionally invariant with classical decay rate γ and (ii) is uniform... [Phys. Rev. Lett. 121, 074101] Published Mon Aug 13, 2018
    Keywords: Nonlinear Dynamics, Fluid Dynamics, Classical Optics, etc.
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  • 67
    Publication Date: 2018-08-14
    Description: Author(s): August E. G. Mikkelsen, Panagiotis Kotetes, Peter Krogstrup, and Karsten Flensberg A metal-semiconductor interface is a promising candidate for a topological superconductor. [Phys. Rev. X 8, 031040] Published Mon Aug 13, 2018
    Electronic ISSN: 2160-3308
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  • 68
    Publication Date: 2018-08-14
    Description: Author(s): A. Wolski and A. T. Herrod Symplectic integrators around a bent reference orbit are obtained in the paraxial approximation with an application to the g-2 storage ring. [Phys. Rev. Accel. Beams 21, 084001] Published Mon Aug 13, 2018
    Keywords: Single-Particle Dynamics
    Electronic ISSN: 1098-4402
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  • 69
    Publication Date: 2018-08-14
    Description: Author(s): Andrey E. Antipov, Arno Bargerbos, Georg W. Winkler, Bela Bauer, Enrico Rossi, and Roman M. Lutchyn A new theoretical treatment provides guidance for fine-tuning the presence of Majorana zero modes, a promising platform for reliable quantum bits, in semiconductor-superconductor nanowires. [Phys. Rev. X 8, 031041] Published Mon Aug 13, 2018
    Electronic ISSN: 2160-3308
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  • 70
    Publication Date: 2018-08-14
    Description: Author(s): Yue-Yue Chen, Jian-Xing Li, Karen Z. Hatsagortsyan, and Christoph H. Keitel Gamma-ray beams with a large angular momentum may affect astrophysical phenomena, which calls for appropriate earth-based experimental investigations. For this purpose, we investigate the generation of well-collimated γ -ray beams with a very large orbital angular momentum using nonlinear Compton sca... [Phys. Rev. Lett. 121, 074801] Published Mon Aug 13, 2018
    Keywords: Plasma and Beam Physics
    Print ISSN: 0031-9007
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  • 71
    Publication Date: 2018-08-14
    Description: Author(s): Emilia V. Silletta, Mark E. Tuckerman, and Alexej Jerschow Water exhibits numerous anomalous properties, many of which remain poorly understood. One of its intriguing behaviors is that it exhibits a temperature of maximum density (TMD) at 4   ° C . We provide here new experimental evidence for hitherto unknown abrupt changes in proton transfer kinetics at the T... [Phys. Rev. Lett. 121, 076001] Published Mon Aug 13, 2018
    Keywords: Condensed Matter: Structure, etc.
    Print ISSN: 0031-9007
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  • 72
    Publication Date: 2018-08-14
    Description: Author(s): I. Petrushina, V. N. Litvinenko, I. Pinayev, K. Smith, G. Narayan, and F. Severino Superconducting rf (SRF) photoinjectors are one of the most promising devices for generating continuous wave (CW) electron beams with record high brightness. Ultrahigh vacuum of SRF guns provides for long lifetime of the high quantum efficiency (QE) photocathodes, while SRF technology provides for h... [Phys. Rev. Accel. Beams 21, 082001] Published Mon Aug 13, 2018
    Keywords: Radio Frequency Calculations and Technology
    Electronic ISSN: 1098-4402
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  • 73
    Publication Date: 2018-08-14
    Description: Author(s): S. Verdú-Andrés, K. Artoos, S. Belomestnykh, I. Ben-Zvi, C. Boulware, G. Burt, R. Calaga, O. Capatina, F. Carra, A. Castilla, W. Clemens, T. Grimm, N. Kuder, R. Leuxe, Z. Li, E. A. McEwen, H. Park, T. Powers, A. Ratti, N. Shipman, J. Skaritka, Q. Wu, B. P. Xiao, J. Yancey, and C. Zanoni Crab crossing is essential for high-luminosity colliders. The high-luminosity Large Hadron Collider (HL-LHC) will equip one of its interaction points (IP1) with double-quarter wave (DQW) crab cavities. A DQW cavity is a new generation of deflecting rf cavities that stands out for its compactness and... [Phys. Rev. Accel. Beams 21, 082002] Published Mon Aug 13, 2018
    Keywords: Radio Frequency Calculations and Technology
    Electronic ISSN: 1098-4402
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  • 74
    Publication Date: 2018-09-05
    Description: Remote Sensing, Vol. 10, Pages 1406: JAXA High-Resolution Land Use/Land Cover Map for Central Vietnam in 2007 and 2017 Remote Sensing doi: 10.3390/rs10091406 Authors: Phan Cao Duong Ta Hoang Trung Kenlo Nishida Nasahara Takeo Tadono Robust remote monitoring of land cover changes is essential for a range of studies such as climate modeling, ecosystems, and environmental protection. However, since each satellite data has its own effective features, it is difficult to obtain high accuracy land cover products derived from a single satellite’s data, perhaps because of cloud cover, suboptimal acquisition schedules, and the restriction of data accessibility. In this study, we integrated Landsat 5, 7, and 8, Sentinel-2, Advanced Land Observing Satellite Advanced Visual, and Near Infrared Radiometer type 2 (ALOS/AVNIR-2), ALOS Phased Array L-band Synthetic Aperture Radar (PALSAR) Mosaic, ALOS-2/PALSAR-2 Mosaic, Shuttle Radar Topography Mission (SRTM), and ancillary data, using kernel density estimation to map and analyze land use/cover change (LUCC) over Central Vietnam from 2007 to 2017. The region was classified into nine categories, i.e., water, urban, rice paddy, upland crops, grassland, orchard, forest, mangrove, and bare land by an automatic model which was trained and tested by 98,000 reference data collected from field surveys and visual interpretations. Results were the 2007 and 2017 classified maps with the same spatial resolutions of 10 m and the overall accuracies of 90.5% and 90.6%, respectively. They indicated that Central Vietnam experienced an extensive change in land cover (33 ± 18% of the total area) during the study period. Gross gains in forests (2680 km2) and water bodies (570 km2) were primarily from conversion of orchards, paddy fields, and crops. Total losses in bare land (495 km2) and paddy (485 km2) were largely to due transformation to croplands and urban & other infrastructure lands. In addition, the results demonstrated that using global land cover products for specific applications is impaired because of uncertainties and inconsistencies. These findings are essential for the development of resource management strategy and environmental studies.
    Electronic ISSN: 2072-4292
    Topics: Architecture, Civil Engineering, Surveying , Geography
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  • 75
    Publication Date: 2018-09-05
    Description: Remote Sensing, Vol. 10, Pages 1405: Investigations on the Coregistration of Sentinel-1 TOPS with the Conventional Cross-Correlation Technique Remote Sensing doi: 10.3390/rs10091405 Authors: Yuxiao Qin Daniele Perissin Jing Bai In Sentinel-1 TOPS mode, the antenna sweeps in the azimuth direction for the purpose of illuminating the targets with the entire azimuth antenna pattern (AAP). This azimuth sweeping introduces an extra high-frequency Doppler term into the impulse response function (IRF), which poses a more strict coregistration accuracy for the interferometric purpose. A 1/1000 pixel coregistration accuracy is required for the interferometric phase error to be negligible, and the enhanced spectral diversity (ESD) method is applied for achieving such accuracy. However, since ESD derives miscoregistration from cross-interferometric phase, and phase is always wrapped to [ − π , π ) , an initial coregistration method with enough accuracy is required to resolve the phase ambiguity in ESD. The mainstream for initial coregistration that meets this requirement is the geometrical approach, which accuracy mainly depends on the accuracy of orbits. In this article, the authors propose to investigate the feasibility of using the conventional coregistration approach, namely the cross-correlation-and-rigid-transformation, as the initial coregistration method. The aim is to quantify the coregistration accuracy for cross-correlation-and-rigid-transformation using the Cramér-Rao lower bound (CRLB) and determine whether this method could eventually help to resolve the phase ambiguities of ESD. In addition, we studied the feasibility and robustness of the cross-correlation plus ESD under different conditions. For validation, we checked whether the cross-correlation plus ESD approach could reach the same coregistration accuracy as geometrical plus ESD approach. In general, for large areas with enough coherence and little topography variance, the cross-correlation method could be used as an alternative to the geometrical approach. The interferogram from the two different approaches (with ESD applied afterward) shows a negligible difference under such circumstances.
    Electronic ISSN: 2072-4292
    Topics: Architecture, Civil Engineering, Surveying , Geography
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  • 76
    Publication Date: 2018-08-14
    Description: Remote Sensing, Vol. 10, Pages 1275: Focusing High-Resolution Airborne SAR with Topography Variations Using an Extended BPA Based on a Time/Frequency Rotation Principle Remote Sensing doi: 10.3390/rs10081275 Authors: Chunhui Lin Shiyang Tang Linrang Zhang Ping Guo With the increasing requirement for resolution, the negligence of topography variations causes serious phase errors, which leads to the degradation of the focusing quality of the synthetic aperture (SAR) imagery, and geometric distortion. Hence, a precise and fast algorithm is necessary for high-resolution airborne SAR. In this paper, an extended back-projection (EBP) algorithm is proposed to compensate the phase errors caused by topography variations. Three-dimensional (3D) variation will be processed in the time-domain for high-resolution airborne SAR. Firstly, the quadratic phase error (QPE) brought by topography variations is analyzed in detail for high-resolution airborne SAR. Then, the key operation, a time-frequency rotation operation, is applied to decrease the samplings in the azimuth time-domain. Just like the time-frequency rotation of the conventional two-step approach, this key operation can compress data in an azimuth time-domain and it reduces the computational burden of the conventional back-projection algorithm, which is applied lastly in the time-domain processing. The results of the simulations validate that the proposed algorithm, including frequency-domain processing and time-domain processing can obtain good focusing performance. At the same time, it has strong practicability with a small amount of computation, compared with the conventional algorithm.
    Electronic ISSN: 2072-4292
    Topics: Architecture, Civil Engineering, Surveying , Geography
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  • 77
    Publication Date: 2018-08-14
    Description: Remote Sensing, Vol. 10, Pages 1272: Mapping Damage-Affected Areas after Natural Hazard Events Using Sentinel-1 Coherence Time Series Remote Sensing doi: 10.3390/rs10081272 Authors: Stephanie Olen Bodo Bookhagen The emergence of the Sentinel-1A and 1B satellites now offers freely available and widely accessible Synthetic Aperture Radar (SAR) data. Near-global coverage and rapid repeat time (6–12 days) gives Sentinel-1 data the potential to be widely used for monitoring the Earth’s surface. Subtle land-cover and land surface changes can affect the phase and amplitude of the C-band SAR signal, and thus the coherence between two images collected before and after such changes. Analysis of SAR coherence therefore serves as a rapidly deployable and powerful tool to track both seasonal changes and rapid surface disturbances following natural disasters. An advantage of using Sentinel-1 C-band radar data is the ability to easily construct time series of coherence for a region of interest at low cost. In this paper, we propose a new method for Potentially Affected Area (PAA) detection following a natural hazard event. Based on the coherence time series, the proposed method (1) determines the natural variability of coherence within each pixel in the region of interest, accounting for factors such as seasonality and the inherent noise of variable surfaces; and (2) compares pixel-by-pixel syn-event coherence to temporal coherence distributions to determine where statistically significant coherence loss has occurred. The user can determine to what degree the syn-event coherence value (e.g., 1st, 5th percentile of pre-event distribution) constitutes a PAA, and integrate pertinent regional data, such as population density, to rank and prioritise PAAs. We apply the method to two case studies, Sarpol-e, Iran following the 2017 Iran-Iraq earthquake, and a landslide-prone region of NW Argentina, to demonstrate how rapid identification and interpretation of potentially affected areas can be performed shortly following a natural hazard event.
    Electronic ISSN: 2072-4292
    Topics: Architecture, Civil Engineering, Surveying , Geography
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  • 78
    Publication Date: 2018-09-06
    Description: Author(s): Thao P. Le and Alexandra Olaya-Castro Quantum Darwinism and spectrum broadcast structure describe the emergence of objectivity in quantum systems. However, it is unclear whether these two frameworks lead to consistent predictions on the objectivity of the state of a quantum system in a given scenario. In this paper, we jointly investiga... [Phys. Rev. A 98, 032103] Published Wed Sep 05, 2018
    Keywords: Fundamental concepts
    Print ISSN: 1050-2947
    Electronic ISSN: 1094-1622
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  • 79
    Publication Date: 2018-09-06
    Description: Author(s): J. Perczel, P. Kómár, and M. D. Lukin The imaging properties of a lens that may perfectly focus electromagnetic waves is investigated at the quantum level. The lens is shown to be diffraction limited, and its role in entangling operations based on dipole-dipole interactions is discussed. [Phys. Rev. A 98, 033803] Published Wed Sep 05, 2018
    Keywords: Quantum optics, physics of lasers, nonlinear optics, classical optics
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  • 80
    Publication Date: 2018-09-06
    Description: Author(s): Shiroman Prakash, Akalank Jain, Bhakti Kapur, and Shubangi Seth We study single-qutrit gates composed of Clifford and T gates, using the qutrit version of the T gate proposed by Howard and Vala [M. Howard and J. Vala, Phys. Rev. A 86 , 022316 (2012) ]. We propose a normal form for single-qutrit gates analogous to the Matsumoto-Amano normal form for qubits. We prov... [Phys. Rev. A 98, 032304] Published Wed Sep 05, 2018
    Keywords: Quantum information
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  • 81
    Publication Date: 2018-09-05
    Description: Sensors, Vol. 18, Pages 2945: A Residual Analysis-Based Improved Particle Filter in Mobile Localization for Wireless Sensor Networks Sensors doi: 10.3390/s18092945 Authors: Long Cheng Liang Feng Yan Wang Wireless sensor networks (WSNs) have become a popular research subject in recent years. With the data collected by sensors, the information of a monitored area can be easily obtained. As a main contribution of WSN localization is widely applied in many fields. However, when the propagation of signals is obstructed there will be some severe errors which are called Non-Line-of-Sight (NLOS) errors. To overcome this difficulty, we present a residual analysis-based improved particle filter (RAPF) algorithm. Because the particle filter (PF) is a powerful localization algorithm, the proposed algorithm adopts PF as its main body. The idea of residual analysis is also used in the proposed algorithm for its reliability. To test the performance of the proposed algorithm, a simulation is conducted under several conditions. The simulation results show the superiority of the proposed algorithm compared with the Kalman Filter (KF) and PF. In addition, an experiment is designed to verify the effectiveness of the proposed algorithm in an indoors environment. The localization result of the experiment also confirms the fact that the proposed algorithm can achieve a lower localization error compared with KF and PF.
    Electronic ISSN: 1424-8220
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
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