bluuebunny/crossref_metadata_2025 huggingface dataset:
Virtual Tide Gauges for Predicting Relative Sea Level Rise
Authors: Hawkins Rhys , Husson Laurent , Choblet Gaël , Bodin Thomas , Pfeffer Julia
Published: November 2019

We present a Bayesian method to map contemporary rates of relative sea level change using a joint inversion of vertical trends from tide gauges, GPS time series, and satellite radar altimetry measurements. Tide gauge measurements constrain rates of relative sea level change on decadal to secular time scales at a few hundred sites sparsely distributed along coastlines. Predicting the rates of relative sea level change from historical tide gauge measurements is difficult due to the paucity and uneven distribution of sites with high quality records. Since the late twentieth century, deployments of GPS stations have enabled accurate determination of the rates of vertical land motion. A series of satellite radar altimetry missions provide continuous and global monitoring of geocentric sea level changes since the launch of TOPEX/Poseidon in 1992. By combining these three observations types into a single Bayesian inversion, we construct continuous maps of rates of relative sea level change, geocentric sea level change, and vertical land motion assuming linear trends, with robust estimates of uncertainties at regional scales. Cross‐validation tests show that reliable predictions of relative sea level changes are still provided where only GPS and satellite altimetry data are used, suggesting this method is viable for studying potential sea level risk for communities where historical tide gauge data are not available. Our results provide spatially and temporally consistent estimates of the various contributions to relative sea level changes.
Seasonal Variation in Sediment Delivery Across the Bay‐Marsh Interface of an Estuarine Salt Marsh
Authors: Lacy Jessica R. , Foster‐Martinez Madeline R. , Allen Rachel M. , Ferner Matthew C. , Callaway John C.
Published: November 2019

Sediment transport across bay‐marsh interfaces depends on wave energy, vegetation, and marsh‐edge morphology and varies over a range of timescales. We investigated these dynamics in a tidal salt marsh with a gently sloped, vegetated edge adjacent to northern San Francisco Bay. Spartina foliosa (cordgrass) inhabits the lower marsh and Salicornia pacifica (pickleweed) predominates on the marsh plain. We measured suspended‐sediment concentration (SSC) and hydrodynamics in bay shallows and along a 100‐m cross‐shore transect in the marsh, during winter and summer. Four‐year averaged accretion measured with marker‐horizon plots was twice as great along the marsh transect as adjacent to a tidal creek, 50 m from the bay. We estimated deposition and trapping efficiency from the time series data to assess its variation with season and wave energy. At high tide the transition zone (between cordgrass and pickleweed) was usually erosional, the pickleweed zone was depositional, and both erosion and deposition increased with wave energy, as did the landward position of maximum deposition. Erosion from the transition zone accounted for approximately one third of the sediment flux into the pickleweed. In the pickleweed zone, SSC, the difference between flood‐ and ebb‐tide SSC, and trapping efficiency were greater in summer than winter for comparable wave conditions, which we attribute to increased sediment trapping by dense summer cordgrass. Moderate waves in summer (46%) accounted for more annual accretion in the pickleweed zone than larger waves in winter (28%), although the contribution of winter storms was diminished by the dry winter during the study.
Vertical Profiling of Aerosols With a Combined Raman‐Elastic Backscatter Lidar in the Remote Southern Ocean Marine Boundary Layer (43–66°S, 132–150°E)
Authors: Alexander S. P. , Protat A.
Published: November 2019

A combined Raman‐elastic backscatter lidar, deployed aboard the research vessel RV Investigator for two campaigns for a total of 10 week's ship time, is used to quantify the properties of aerosols within the remote Southern Ocean marine boundary layer between Australia and Antarctica in the region 43–66°S and 132–150°E. Eleven Raman case studies are identified for analyses. Particle linear depolarization ratio and height‐resolved lidar ratio S, calculated from the Raman retrievals, are consistent with values expected within the surface mixed layer for clean marine conditions. We determine S=(19±7) sr across the Southern Ocean with the Raman lidar observations. Aerosol optical properties in the marine boundary layer close to Tasmania (43°S) sometimes indicate the influence of continental air masses. Aerosol optical depth at 355 nm calculated from the retrieved Raman extinction profiles within the surface mixed layer is τ=(0.11±0.04). Boundary‐layer height is determined from the lidar observations and decreases from (0.9±0.4) km north of the Polar Front (around 55°S) to (0.7±0.2) km south of the Polar Front. Dried sea salt is present above the midlatitude ocean in the dehumidified decoupled layer in different synoptic‐scale atmospheric conditions including beneath a high‐pressure system and in a post‐frontal air mass. At all latitudes across the Southern Ocean, large aerosol backscatter, low depolarization ratio, and high relative humidity indicate the presence of sea salt droplets within the well‐mixed near‐surface layer.
On the Causal Relationship Between the Moist Diabatic Circulation and Cloud Rapid Adjustment to Increasing CO2
Authors: Dinh T. , Fueglistaler S.
Published: November 2019

General circulation models predict that clouds in the atmosphere rapidly adjust to the radiative perturbation of an abrupt increase in atmospheric CO2 concentration on a short time scale of about 10 days. This rapid adjustment consists of an increase of clouds in the boundary layer and a decrease of clouds in the free troposphere. Our focus is the mechanism for the decrease of clouds in the free troposphere, which is the dominating component of cloud rapid adjustment in most general circulation models. We propose that the decrease in clouds in the free troposphere arises from the causal relationship between the moist diabatic circulation and the production of condensates that forms clouds in moist processes. As CO2 concentration increases, tropospheric radiative cooling is reduced, resulting in weakening of the moist diabatic circulation and a decrease in precipitation. As the hydrologic cycle weakens and the moist processes involving phase change of water vapor to form the condensates in the atmosphere lessen, the mass of cloud condensates decreases. This decrease in cloud condensates can be predicted from the decrease in the radiative subsidence mass flux, which is a metric for the strength of the moist diabatic circulation in the free troposphere.
Precessional Drivers of Late Miocene Mediterranean Sedimentary Sequences: African Summer Monsoon and Atlantic Winter Storm Tracks
Authors: Marzocchi Alice , Flecker Rachel , Lunt Daniel J. , Krijgsman Wout , Hilgen Frits J.
Published: November 2019

Cyclic sedimentary patterns in the marine record of the Mediterranean Sea have been consistently correlated with orbitally‐driven shifts in climate. Freshwater input driven by the African summer monsoon is thought to be the main control of such hydrological changes, where the runoff signal is transferred from the eastern to the western Mediterranean. The geological record from the Atlantic margin also contains precession‐driven dilution cycles that have been correlated with the sedimentary sequences in the western and eastern Mediterranean despite the lack of a direct connection with the basin. In these regions, Atlantic winter storms have also been invoked to explain the wet phases. In the absence of seasonally‐resolved proxy data, climate simulations at high temporal resolution can be used to investigate the drivers of Mediterranean hydrologic changes both on precessional and seasonal timescales. Here, we use the results of 22 ocean‐atmosphere‐vegetation simulations through an entire late Miocene precession cycle. These show that the African summer monsoon drives the hydrologic budget in the Eastern Mediterranean during precession minima, while the western marginal basins are generally dominated by local net evaporative loss. During precession minima, the western Mediterranean and the Atlantic margin are also influenced by enhanced winter precipitation from the Atlantic storm tracks. We can, therefore, identify two different moisture sources affecting the circum‐Mediterranean area, characterized by the same phasing with respect to precession, but with opposite seasonality. This supports the interregional correlation of geological sections in these areas, as we show for the Messinian and speculate for other time periods.
The Influence of Sudden Commencements on the Rate of Change of the Surface Horizontal Magnetic Field in the United Kingdom
Authors: Smith A. W. , Freeman M. P. , Rae I. J. , Forsyth C.
Published: November 2019

Sudden commencements (SCs) are rapid increases in the northward component of the surface geomagnetic field, related to sharp increases in the dynamic pressure of the solar wind. Large rates of change of the geomagnetic field can induce damaging currents in ground power networks. In this work, the effect of SCs on the (1 min) rate of change of the surface magnetic field (R) at three U.K. stations is investigated. The distributions of R during SCs are shifted to higher values than the data set as a whole. Rates of change greater than 10 nT/min are 30–100 times more likely during SCs, though less than 8% of the most extreme R (≥99.99th percentile) are observed during SCs. SCs may also precede geomagnetic storms, another potential source of large R. We find that the probability of observing large a R is greatly enhanced for 3 days following an SC. In the 24 hr following an SC it is 10 times more likely than at any given time to observe rates of change between 10 and several hundred nT/min. Additionally, between 90% and 94% of data (depending on station) above the 99.97th percentile is recorded within 3 days of an SC. All values of R ≥ 200 nT/min in the United Kingdom have been observed within 3 days of an SC. These results suggest that accurately predicting SCs is critically important to identify intervals during which power networks at similar geomagnetic latitudes to the United Kingdom are at risk from large geomagnetically induced currents.
Hydrological Drought Simulations: How Climate and Model Structure Control Parameter Sensitivity
Authors: Melsen L. A. , Guse B.
Published: November 2019

Hydrological drought, defined as below‐average streamflow conditions, can be triggered by different mechanisms, which are to a large extent dictated by the climate. Moreover, the simulation of hydrological droughts highly depends on the model structure and how drought‐triggering mechanisms are parameterized. In this large‐sample hydrological study, we investigate how climate and model structure control hydrological drought simulations. We conducted sensitivity analysis on parameters of three frequently used hydrological models (HBV, SAC, and VIC) for the simulation of drought duration and drought deficit over 605 basins covering more than 10 different Köppen‐Geiger climates. The sensitivity analysis revealed that, as anticipated, different parameters are sensitive in different climates. However, not all expected drought mechanisms were reflected in the parameter sensitivity: Especially, the sensitivity of ET parameters does not align with the theory, and the role of snow parameters in snow‐related droughts shows a distinction between degree‐day‐based models and energy‐balance models. Besides parameter sensitivity being different over climates, we also found that parameter sensitivity differed over the different models. Where HBV and SAC did display fairly similar behavior, in VIC other model mechanisms were triggered. This implies that conclusions on driving mechanisms in hydrological drought cannot be based on hydrological models only, as different models would lead to different conclusions. Hydrological models can have heuristic value in drought research, to formulate new theories and identify research directions, but formulated theories on driving processes should always be backed up by observations.
Depth‐Resolved Groundwater Chemistry by Longitudinal Sampling of Ambient and Pumped Flows Within Long‐Screened and Open Borehole Wells
Authors: Poulsen David L. , Cook Peter G. , Simmons Craig T. , Solomon D. Kip , Dogramaci Shawan
Published: November 2019

Depth‐resolved chemistry samples are critical to a wide range of groundwater investigations. If a well intersects zones of variable concentrations, a pumped sample is a composite of the inflows, which mix in the well. Where discrete concentrations are required, excessive mixing makes samples less useful and potentially misleading. However, installations for depth‐discrete sampling are expensive, particularly for regional studies, so sometimes there is incentive to use existing infrastructure designed for other purposes (e.g., supply wells). This paper shows how the resolution of groundwater chemistry derived from long‐screened and open borehole wells can be improved by measuring and sampling the in‐well vertical flow regimes in ambient (unpumped) and/or pumped conditions. The ambient flow regime, driven by a natural vertical head gradient, is shown to be particularly useful to sample groundwater native to defined inflow zones (head in the zone > head in the well) and avoid zones impacted by the invasion of intraborehole flow (head in the zone < head in the well). Depth‐specific samples are interpreted either as native groundwater from a discrete source, subject only to analytical error, or a mixture from multiple sources that can be deconvolved, incorporating error in both flow and concentration measurements. Depth‐resolved age tracers (chlorofluorocarbons, 14C, and He) in groundwater from three supply wells are verified with samples from a multidepth nest of piezometers. Results show old groundwater at all depths and the simultaneous occurrence of young water at shallower depths in undisturbed dual‐porosity fractured aquifers in the Pilbara region of Western Australia.
Non‐Newtonian Backflow in an Elastic Fracture
Authors: Chiapponi Luca , Ciriello Valentina , Longo Sandro , Di Federico Vittorio
Published: November 2019

Backflow phenomenon, as a consequence of hydraulic fracturing, is of considerable technical and environmental interest. Here, backflow of a non‐Newtonian fluid from a disk‐shaped elastic fracture is studied theoretically and experimentally. The fracture is of constant aperture h and the outlet section at constant pressure pe. We consider a shear‐thinning power‐law fluid with flow behavior index n. Fracture walls are taken to react with a force proportional to hλ, with λ a positive elasticity exponent; for λ=1 linear elasticity holds. Constant overload f0, acting on the fracture, is also embedded in the model. A transient closed‐form solution is derived for the (i) fracture aperture, (ii) pressure field, and (iii) outflow rate. The particular case of a Newtonian fluid (n=1) is explicitly provided. For pe=0 and f0=0, the residual aperture and outflow rate scale asymptotically with time t as t−n/(n+λ+1) and t−(2n+λ+1)/(n+λ+1), respectively, thus generalizing literature results for n=1 and/or λ=1. For nonzero exit pressure and/or overload, the fracture aperture tends asymptotically to a constant value depending on λ, n, pe, f0, and other geometrical and physical parameters. The results are provided in dimensionless and dimensional form, including the time to achieve a given percentage of fluid recovery. In addition, an example application (with values of parameters derived from field scale applications) is included to further characterize the influence of fluid rheology. Experimental tests are conducted with Newtonian and shear‐thinning fluids and different combinations of parameters to validate the model. Experimental results match well the theoretical predictions, mostly with a slight overestimation.
Hyaluronic acid hydrophilic surface rehabilitating curcumin nanocrystals for targeted breast cancer treatment with prolonged biodistribution
Authors: Ji Peng , Wang Le , Chen Yiwei , Wang Siqi , Wu Zhenghong , Qi Xiaole
Published: November 2019

Due to its high therapeutic efficiency and low systemic toxicity, natural bioactive curcumin has attracted more and more attention as a potential antineoplastic drug.
Synthesis of pyrano[2,3-f]chromen-2-ones vs. pyrano[3,2-g]chromen-2-ones through site controlled gold-catalyzed annulations
Authors: Arcadi Antonio , Ciogli Alessia , Fabrizi Giancarlo , Fochetti Andrea , Franzini Roberta , Ghirga Francesca , Goggiamani Antonella , Iazzetti Antonia
Published: November 2019

A regioselective intramolecular hydroarylation of 7-(prop-2-yn-1-yloxy)-2H-chromen-2-one derivatives to afford 10-substituted-2H,8H-pyrano[2,3-f]chromen-2-ones by means of Au(i) catalysis.
Controllable synthesis of pyrido[2,3-b]indol-4-ones or indolo[3,2-b]quinolines via formal intramolecular C(sp2)–H functionalization
Authors: Song Bo , Wang Mengdan , Xu Murong , Kong Lingkai , Xie Huihui , Wang Chengyu , Li Yanzhong
Published: November 2019

An atom-economical Fe-catalyzed protocol for the controllable synthesis of pyrido[2,3-b]indol-4-ones or indolo[3,2-b]quinolines through C–H/N–H coupling reactions. The natural product quindolinone was conveniently prepared by this reaction.
Alignment of theoretically grounded constructs for the measurement of science and chemistry identity
Authors: Hosbein Kathryn N. , Barbera Jack
Published: November 2019

Identity has been theorized to aid in student persistence within STEM disciplines. In this study, science and chemistry identity were defined as being recognized as a science or chemistry person within the classroom. To generalize the effects that identity has on student persistence, a measurable construct must be defined, operationalized, and tested in multiple settings with different populations. This project addressed the first step in the process, defining the construct and grounding it in an established theoretical framework. This qualitative project utilized a previously described physics identity framework, with sub-constructs of performance/competence, recognition, and interest, as a starting point for the alignment of students’ perceptions of identity to the broader theoretical frameworks of identity. Nine semi-structured interviews were conducted with students from a range of chemistry courses at Portland State University. The interviews consisted of questions pertaining to the sub-constructs of identity. Thematic analysis was used to define emerging themes within student responses. These themes were found to align with an array of affective constructs, including mastery experiences, verbal persuasion, vicarious experiences, situational interest, and mindset. These constructs will be used to develop an identity measure for chemistry education that is grounded in the broader theoretical frameworks of identity.
Ultramicropore-influenced mechanism of oxygen electroreduction on metal-free carbon catalysts
Authors: Barrera Deicy , Florent Marc , Kulko Margarita , Bandosz Teresa J.
Published: November 2019

Microporous carbons, with nitrogen groups or without, were synthesized and tested as ORR catalysts. A strong dependence of the ORR efficiency on the combined V<0.7nm, ECSA, and the number of dissociating groups (expressed as PIF) was found.
Reversible and irreversible colossal barocaloric effects in plastic crystals
Authors: Aznar Araceli , Lloveras Pol , Barrio María , Negrier Philippe , Planes Antoni , Mañosa Lluís , Mathur Neil D. , Moya Xavier , Tamarit Josep-Lluís
Published: November 2019

Colossal barocaloric effects were observed in four species of plastic crystals, and two displayed the reversibility required for cooling devices.
Calculation and validation of stray‐field loss in magnetic and non‐magnetic components under harmonic magnetizations based on TEAM Problem 21
Authors: Zhao Xiaojun , Wang Jiawen , Liu Lanrong , Cheng Zhiguang , Yuan Dongwei
Published: November 2019

On the basis of the TEAM problem 21 benchmark model, a modelling method to predict stray‐field loss under real working conditions is presented and validated to investigate the influence of harmonic excitation on stray‐field loss of shielding structural components of converter transformers in high‐voltage direct current systematically. An improved method is adapted to determine stray‐field loss of magnetic and non‐magnetic component based on the experimental measurement and numerical simulation. An experimental platform is established to measure magnetic properties and loss characteristics of the grain‐oriented silicon steel sheets, aiming at parameter identification and verification of the loss modelling applicable for laminated sheets under harmonic magnetisation. Meanwhile, the additional iron loss caused by perpendicular flux penetration is obtained by special treatment of material properties and analysed to observe its contribution to the stray‐field loss under three‐dimensional harmonic magnetisation. Field and loss comparison between measurement and simulation verifies the validation of the proposed modelling method.
Low torque ripple tooth coil windings multi‐3‐phase machines: design considerations and validation
Authors: Diana Michela , Ruffo Riccardo , Guglielmi Paolo
Published: November 2019

In multi‐n‐phase machines, the n‐phases are grouped in separated stars. A particular subcategory of multi‐n‐phase machines is the multi‐3‐phase machines. This study presents the design considerations and their validation for tooth coil wound multi‐3‐phase machines. A generic algorithm to design multi‐3‐phase machines is proposed. Although this study mainly focuses on multi‐3‐phase machines the approach is generalised and is applicable to any multi‐n‐phase machine. The resulting machines exhibit a low torque ripple value, and a mathematical formulation is proposed in order to justify this behaviour. All the multi‐3‐phase machines designed according to the proposed algorithm can be studied, and directly compared, thanks to the generalised harmonic formulation of the stator MMF and the torque performances here proposed. This study is enriched with some design hints useful to realise a machine with low mutual coupling between phases, and some considerations that can help the machine designer in the choice of the number of poles. The design algorithm is applied for the design of a triple‐3‐phase PM‐inset machine solution, with nine slots ten poles. The performances, evaluated by finite element analysis and experimental analysis, demonstrate the effectiveness of the design algorithm proposed in a very simple structure machine.
Rotor magnet demagnetisation diagnosis in asymmetrical six‐phase surface‐mounted AC PMSM drives
Authors: Gritli Yasser , Mengoni Michele , Rizzoli Gabriele , Rossi Claudio , Tani Angelo , Casadei Domenico
Published: November 2019

Multiphase permanent‐magnet synchronous machines (PMSMs) are receiving more and more interest in safety‐critical modern industries owing to their higher reliability when compared with conventional three‐phase PMSMs. Rotor magnets are critical components, which, in case of fault, directly affect the performance of the PMSMs. Thus, monitoring the rotor magnets status is essential to ensure both high level of efficiency and service continuity. The present study focuses on the investigation of a new approach for the detection of rotor magnet demagnetisation in a vector‐controlled asymmetrical six‐phase surface‐mounted AC PMSM. The main contribution of the proposed technique is the assessment of a rotor demagnetisation fault index derived from the fifth and seventh harmonics of the stator voltage space vector evaluated in the α 5–β 5 ‐plane, and already available in the control system platform. The performance of the proposed approach is evaluated using finite element analysis and numerical simulations, both validated by experimental tests.
Interior permanent magnet synchronous motor minimum current harmonics torque ripple suppression strategy based on magnetic co‐energy model
Authors: Yi Peng , Wang Xinjian , Sun Zechang
Published: November 2019

Permanent magnet synchronous motors are widely used in electric vehicles. The permanent magnet synchronous motor torque ripple suppression is a research hotspot at present. This study adopts the torque ripple equation based on magnetic co‐energy. Two novel minimum current harmonics torque ripple suppression strategies based on the magnetic co‐energy are proposed. Both methods are suitable for whole current map calculation. One is based on dq‐axis model, which makes the dq‐axis current harmonics fluctuate along gradient direction of the torque equation to dq‐axis currents. The other one is based on the newly proposed torque–current coupling model. The minimum current harmonics obtained by the two methods are basically the same. At last, finite element method and test bench experiment are used to verify the two methods. Both of them can effectively suppress torque ripple.
Rotor fault diagnosis in permanent magnet synchronous machine using the midpoint voltage of windings
Authors: Bossio José , Ruschetti Cristian , Bossio Guillermo , Verucchi Carlos , De Angelo Cristian
Published: November 2019

A new strategy is proposed here for the diagnosis of asymmetric demagnetisation in permanent magnet synchronous machines. The strategy is based on the measuring of the voltage at the midpoint of the windings within a phase. Unlike the phase voltage, for a fault situation, the midpoint voltage shows sidebands around the fundamental component, which allows detecting and quantifying the demagnetisation phenomenon. A low‐cost implementation for the automatic detection of faults is also proposed in the present study and experimental results are presented to validate the strategy.
Contribution of winding space harmonics to average torque in fractional‐slot concentrated permanent magnet machines with equal/unequal teeth
Authors: Sun Haiyang , Wang Kai , Li Feng , Kong Jinwang , Gu Zhengyong
Published: November 2019

This study investigates the modulation effects in any m‐phase permanent magnet machines with fractional‐slot concentrated windings and separates the average torque contributed by the winding space harmonics, with particular emphasis on unequal stator teeth. First, winding space harmonics of m‐phase machines with double/single layer windings are analysed and modulation effects of equal/unequal teeth are studied. It is found that, apart from the conventional torque contributed by main harmonic (v = p) and modulated torque by v = p ± Ns harmonics (Ns is slot number and p is pole pair number), additional modulated torque owing to v = p ± Ns/2 harmonic appears in the unequal teeth machines. Then, 12‐slot/10‐pole (12S10P) three‐phase and 10S8P five‐phase machines are employed to verify the analysis through finite element method. It is demonstrated that, for unequal teeth machine, v = p − Ns and v = p − Ns/2 harmonics have positive average torque contribution, around 6.5 and 6% to the total torque. The v = p + Ns and v = p + Ns/2 order harmonics produce negative average torque but with much smaller values. Finally, experiments are carried out on the 10S8P unequal teeth prototype.
Image quality assessment via spatial‐transformed domains multi‐feature fusion
Authors: Yu Miaomiao , Zheng Yuanlin , Liao Kaiyang , Tang Zhisen
Published: November 2019

The basis of image processing is to evaluate and monitor image quality using algorithms rather than subjective methods. Conventional gradient operators have been popularly used in previous image quality assessment tasks to reflect the edge contour of an image, while there are some obvious defects in terms of the selection of mask scale and direction. Some improved versions are also less than ideal since they fail to consider the gradient information of the same pixel in different directions at the same time. The authors adopt a powerful gradient operator that can simultaneously capture edge information in all four directions at the same pixel point with more relevant values being considered instead of selecting the maximum in these four directions. Furthermore, four complementary types of features extracted from the spatial and transform domains are considered. A set of 12‐dimensional feature vectors is generated for each image by multi‐feature fusion. Ultimately, random forest regression technique is employed to train their model and then map the distortion effects to the prediction scores. The experimental results show that the proposed FVC‐G has better overall performance, more powerful cross‐database operation capability, and higher visual consistency than other advanced methods.
From pyramids to state‐of‐the‐art: a study and comprehensive comparison of visible–infrared image fusion techniques
Authors: Sharma Apoorav M. , Dogra Ayush , Goyal Bhawna , Vig Renu , Agrawal Sunil
Published: November 2019

Image fusion has emerged as a major area of research in the past few decades due to its extended applications. While progressing in the field of image fusion, a large number of techniques‐based image transforms and spatial filters have been devised for both general and specific sets of images. The primary criterion of image fusion technique is to deliver high‐quality visual perception besides giving a considerable objective evaluation rate. In this study, an information fusion rate‐based study is done on recent, most researched, and high‐performing state‐of‐the‐art techniques using visible and infrared image datasets. These techniques have been chosen carefully, owing to their superiority in performance on both objective and subjective scales of evaluation and have been discussed in terms of their respective advantages and disadvantages. It is clearly evident that some rather primitive techniques can perform well as well as techniques based on a hybrid of various domains can significantly boost the information fusion rate.
Novel multiple images encryption algorithm using CML system and DNA encoding
Authors: Zhang Hao , Wang Xiao‐qing , Wang Xing‐yuan , Yan Peng‐fei
Published: November 2019

In this study, the authors advance a novel multiple images encryption algorithm using the coupled map lattices (CML) system and DNA encoding. The algorithm adopts a permutation‐diffusion structure. First, the initial values and parameters of the CML system are determined by given values and SHA hash key of original images. Secondly, several plain images are grouped and permuted among groups. Next, different groups are combined into eight blocks of the same size, each of which is independently coded and scrambled. Thirdly, in the diffusion process, a DNA‐level multiplication operation is redefined, and required key matrices are resulted from a small key connected with original images. Finally, dynamic DNA coding/decoding is adopted, and the coding and decoding rules are determined by original images. The evaluation of the simulation experiment shows that the proposed algorithm is safe and feasible, and has good encryption effect.
Comprehensive perspective on virtual inductor for improved power decoupling of virtual synchronous generator control
Authors: Wen Tiliang , Zou Xudong , Zhu Donghai , Guo Xiang , Peng Li , Kang Yong
Published: November 2019

The virtual inductor is widely used in the virtual synchronous generator (VSG) control to attain predominantly inductive impedance and reduce the power coupling. In fact, ‘predominantly inductive impedance’ is a misleading indicator of decoupling performance. In this study, a comprehensive perspective on virtual inductor is given for the improved decoupling performance of VSG control. A small‐signal model is proposed to make a thorough inquiry into the effects of virtual inductor on power decoupling. With the proposed model, the optimal value of virtual inductor is obtained, the physical interpretation of the optimal decoupling is revealed, and the necessity of using virtual inductor is discussed. First, with optimisation of the value of virtual inductor, some negative effects of excessively large virtual inductor on power decoupling can be avoided. The excessively large value of virtual inductor will deteriorate the performance of power decoupling, aggravate the reactive power shortage of the grid and increase the capacity demand of voltage‐source converter. Additionally, when the grid inductance is larger than the threshold value, virtual inductor is not needed. After that, the external physical characteristics of VSG when the grid inductance is under that critical condition are analysed. Finally, the theoretical analysis is validated by simulation and experiments.
Energy dissipation of MMC‐HVDC based onshore wind power integration system with FB‐DBS and DCCB
Authors: Cao Shuai , Xiang Wang , Lu Xiaojun , Lin Weixing , Zhang Kai , Wen Jinyu , Zhang Xin
Published: November 2019

With the development of high‐voltage direct current (HVDC), modular multilevel converter (MMC) is seeking its application in onshore wind power integration. AC and DC faults are important issues for the wind power integration system, during which the wind generation system continuously provides wind power and the surplus power may cause overvoltage to sub‐modules of MMC. This study focuses on the energy dissipation during AC and DC faults for the overhead‐line MMC‐HVDC system integrating large‐scale wind power. A two‐terminal MMC‐HVDC system with permanent magnet synchronous generator based wind farm is studied. Hybrid DC circuit breakers (DCCBs) are employed to interrupt DC fault current and the method based on measuring the rate of change of DC line voltage is adopted to trip DCCBs. Also a full‐bridge sub‐module based dynamic braking system (FB‐DBS) is implemented at the DC link to absorb the surplus wind power in case of AC or DC faults in the HVDC grid. To ride‐through AC and DC faults without blocking IGBTs, the control of hybrid DCCB and the system fault ride‐through strategies are properly designed. PSCAD/EMTDC simulations are shown to demonstrate theoretical analysis.
Robust power balancing scheme for the grid‐forming microgrid
Authors: Chandak Sheetal , Bhowmik Pritam , Rout Pravat Kumar
Published: November 2019

Control over the voltage and the frequency instabilities in a grid‐forming microgrid due to the power mismatch conditions become the point of concern. Therefore, the study implements a self‐tuned proportional–integral integrated active power–voltage drooping and reactive power–frequency boosting control strategy for the precise power sharing among the distributed generators. Furthermore, to handle the power deficit scenarios and protect the system from the blackout, a system independent and priority‐based adaptive three‐stage load shedding strategy is proposed. The sensitivity of the strategy depends on the system inertia and is computed according to the varying absolute rate‐of‐change‐of‐frequency. The strategy incorporates the operation of a hybrid storage system comprised of battery and supercapacitor present in the microgrid, to provide a reliable power supply to the customers for a considerable time rather than a sudden load shedding. The effectiveness of the proposed strategies is investigated on a modified IEEE 13‐bus system. The study is simulated in the time domain, on the podium of MATLAB 2015b.
A diurnal carbon engine explains13C-enriched carbonates without increasing the global production of oxygen
Authors: Geyman Emily C. , Maloof Adam C.
Published: November 2019

Significance

We present stable carbon isotope (δ13C) data from modern carbonate sediment that require a decoupling of the carbon cycles in the global ocean versus shallow carbonate shelves. This realization is important because, for the first 97% of Earth history, many inferences about global paleoclimate and seawater chemistry rely on interpretations of shallow carbonates. We use modern observations and a simple model to show how ordinary diurnal carbon cycling in shallow waters is sufficient to produce anomalously positiveδ13C on shelves today, and in the geological record. Our results alleviate the need to interpret positiveδ13C excursions in the geological record as global reorganizations of the carbon cycle and instead linkδ13C to local and/or global paleoenvironmental and paleoecological controls.
Traveling wave solutions for the spatial diffusion of bird flu model
Authors: Rince Putri Arrival , Husna Radhiatul
Published: November 2019

We describe mathematical model to study bird flu transmission in bird system and human system. The behaviour of this model was analyzed through stability of constant solutions. Our result shows that these stabilities depend on values of some parameters. Furthermore, the model of bird system is reformulated by adding diffusive term. Traveling wave solutions of the diffusive model were investigated. The positive solutions are numerically illustrated with homogeneous Neumann boundary conditions. The result shows that transmission progress can be expressed in form of a traveling wave solutions.
Direct and indirect grouping strategies for a multi-item probabilistic inventory model
Authors: Koswara Handi , Lesmono Dharma
Published: November 2019

In this paper we develop joint replenishment strategies, namely direct and indirect grouping to find the optimal solution for a multi-item probabilistic inventory problem. Basically, direct grouping is a strategy to group items according to a predetermined ratio of holding cost and minor ordering cost. On the other hand, in indirect grouping strategy, items are ordered every predetermined basic cycle time with a possibility that not all items are ordered. We assume that demands are normally distributed and all shortages are backordered. In developing our model, we also develop an algorithm for direct and indirect grouping. In the numerical experiments, we consider six items with their own parameters, ordered from one supplier, and compare the total inventory cost between direct and indirect grouping strategies. We found that in our examples that indirect grouping strategies gives lower total inventory cost than direct grouping strategy.
Path analysis of entrepreneurial motivations in tourism based on local resources and creative economy in nagari salayo of west sumatra
Authors: Devianto Dodi , Ridho Muhammad , Maryati Sri , Lenggogeni Sari
Published: November 2019

The purpose of this study is to analyze the entrepreneurial motivations in tourism based on local resources and creative economy in Nagari Salayo of West Sumatra in developing this area into a cultural and creative based tourist destination. The sixty beginner entrepreneurs are involved in this research in community services, where their entrepreneurial motivations are measured by an entrepreneurial motivation scale of the questionnaire and analyzed by using path analysis in determining the relationship between personality characteristic motivation cores. The statistical path model showed significantly affecting of working motive and social motive to capability of entrepreneurial as a direct effect, in contrast only working motive influenced of intention of entrepreneurs, and the capability of entrepreneurial as mediation variable for indirect effects of entrepreneurial motive to intention entrepreunerial. This analysis suggests the model that entrepreneurial motivations have effect to capacity and intention of beginner entrepreneurs to develop business on tourism based on local resources and the creative economy.
Poisson gamma model in empirical Bayes of small area estimation (SAE)
Authors: Yanuar Ferra , Eka Putri Nadya Cindy , Yozza Hazmira
Published: November 2019

This study aims to describe the empirical Bayes estimator for small area estimation which use Poisson Gamma as prior distribution. The method then apply to generated data and model it with and without indicator variable. Parameter model estimated uses direct method and indirect method (known as empirical Bayes approach; with and without indicator variable). The choice of better estimator is based on MSE with Jackknife method. The criteria of acceptable proposed model are based on Deviance, Scaled Deviance, Pearson ChiSquare and Scaled Pearson Chi-square. This study proves that empirical Bayes in SAE with indicator variable result better estimated values than two other methods. All criteria of acceptable model indicate that proposed model could be accepted. Based on plot between the estimated residual versus predicted values of response variable informed that proposed model is plausible enough.
Leaf feature extraction using glcm, moment invariant and shape morphology for indonesian medicinal plants recognition
Authors: Syahputra Hermawan , Indra Zulfahmi , Febrian Didi , Putri Adriani Dhea
Published: November 2019

This study aims to determine the extraction of GLCM texture features, shape morphology and moment invariant features on the leaf image of medicinal plants and determine the accuracy of plant recognition based on these three features by using Artificial Neural Network Classifiers. The procedure performed to classify medicinal plants based on their leaf image is image acquisition, image pre-processing, feature extraction, image classification and calculating the accuracy of test results. The introduction had tested for ten Indonesian medicinal plant samples, namely: Bangun-Bangun, Binahong, Jarak, Kemuning, Mangkokan, Mengkudu, Pegagan, Sambiloto, Sambung Nyawa, and Sirih. Based on the test results, obtained 97% accuracy with GLCM features, 69% with Shape Morphological features, 86% with GLCM and Shape Morphological features and 79% with moment invariant features.
Constructive heuristic for the mixed capacitated arc routing problem with multi capacity
Authors: Masran H , Ramli M F
Published: November 2019

This paper addresses a variant of the capacitated arc routing problems known as the mixed capacitated arc routing problem (MCARP) with multi capacity constraints. The MCARP represents closely real life situations since it takes into account directed and undirected links to serve customers in the associated network. A constructive heuristic based on insertion techniques is proposed to tackle the problem. Computational experiments were conducted using some randomly generated instances and the experiments show competitive results. Some avenues for future research are also highlighted.
Characteristics of bidikmisi’s scholarship awardee in FMIPA UNP using chi-squared automatic interaction detection
Authors: Amalita Nonong , Kurniawati Yenni , Fitria Dina
Published: November 2019

Bidikmisi’s Scholarships is a funding assistance from government to help students in the university who lack economically but good in academic. Number of awardee in FMIPA UNP increases yearly. So, we have to know classification of awardee to make sure that scholarship is received by the right one. We use CHAID-Chi-Squared Autimatic Interaaction Detection analysis. Result of the research, there are five groups awardee. Characteristics of awardee is father’s jobs (farmers, motor driver, jobless) and area of their house approximately 50 m2.
Variational approximations for intersite soliton in a cubic-quintic discrete nonlinear Schrödinger equation
Authors: Putri N Z. , Asfa R. , Fitri A A. , Bakri I. , Syafwan M.
Published: November 2019

In this paper, the approximation for stationary soliton solution with intersite-typed configuration in the cubic-quintic DNLS equation for anti-continuum limit is determined by a variational approximation (AV) method. The proposed ansatz is of the form an exponential function with three variational parameters. The obtained VA solutions are then examined its validation and compared with the corresponding numerical solutions. The results show that the VA solutions are valid and provide a very good agreement with the numeric.
The Comparison of Fourth Order Runge-Kutta and Homotopy Analysis Method for Solving Three Basic Epidemic Models
Authors: Yong B
Published: November 2019

All epidemic models include a system of non-linear differential equation. Mostly the analytical solution of epidemic model is difficult to obtain. There are many different methods to solve non-linear differential equation, one of them is homotopy analysis method. The homotopy analysis method is an analytic approximation method using series solution for highly non-linear equations. The advantage of this method is a guarantee the convergence of approximation power series solution by choosing suitable values of the auxiliary parameter. In this paper, we consider three epidemic models in a closed population without demographics; SI, SIR, and SEIR models. We find the solutions of the models by homotopy analysis method and then compare the numerical results with fourth order Runge-Kutta method. The homotopy analysis method gives a good result for the solution of the epidemic models with a few iterations and the solutions obtained from this method are good as compared to fourth order Runge-Kutta numerical method.
Optimization and analysis of some oxinate metal complex system as introduction test for HPLC analysis
Authors: Oktavia Budhi , Purnama Sari Mega , Comala Sary Ratih , Lisa Mona , Nasra Edi , Zainul Rahadian , Efendi Jon
Published: November 2019

Heavy metals are metals that have a mass of more than 5 g / cm3 in the lower right corner of the periodic system. Heavy metals rarely form atoms themselves in water, but are usually bound by other compounds to form molecules. Heavy metal is a chemical compound that has the potential to cause environmental pollution problems. Methods of heavy metal content analysis in the aquatic environment developed simultaneously are still being developed. The simultaneous analysis provides an advantage in terms of time and cost efficiency. In this study is being developed heavy metal analysis based on the formation of complexes with oxin compounds. It is known that the oxide can form a yellow complex with several metal ions. The use of oxine as a complex is selected based on the color and pH of the complexes formed. By performing optimization and analysis of the complex system formed it is expected to produce an excellent method for the analysis of several heavy metals simultaneously using High Performance Liquid Chromatography (HPLC).
Application of chitosan crosslink as selective adsorbent
Authors: Hasri  , Auliah Army , Pratiwi Diana E , Sulfikar  , Yusaerah Nur
Published: November 2019

A selective chitosan adsorbent may remove Cd2+and Pb2+ions in aquatic environment to reduce pollution. This study has applied crosslink chitosan to reduce Cd2+and Pb2+ions in water. The study is related to the searching of optimum condition with respect to citric acid and sodium tripolyphosphate concentrations in a batch method. The study also includes the determination of optimum pH and interaction study of complex molecule with either Cd2+or Pb2+ions in relation to competitive chitosan adsorption. The optimum pH is found at pH 5. The optimum concentration of citric acid with chitosan is found to be 1% (b / v). It is concluded that chitosan adsorbent is selective for Pb2+over Cd2+ions.