bluuebunny/crossref_metadata_2025 huggingface dataset:
Bipolaris victoriae (Victoria blight of oats).
Authors: Taylor Philip
Published: March 2021

A disease almost unknown prior to 1944 (Romanko, 1957), Bipolaris victoriae is a potentially destructive disease of oats (it reduced the Iowa oat crop by 32% in 1947) (Anon, 1965) that currently has a limited host range and geographical spread. It has been reported from several continents and associated with several crops, however its status as a pathogen on crops could be questioned in all cases with the exception of oats, timothy grass and switch grass. It is seedborne and thus any trade in seed both for cultivation or for livestock feed is a potential means of spread. The virulence of the fungus is due to the production of a peptide often called a host-specific toxin 'victorin'. The disease has generally been controlled through the use of genetically resistant lines but the resistance gene which confers resistance to victorin actually causes plants to become susceptible to crown rust, caused by Puccinia coronata (Lorang et al., 2007).
Coptotermes formosanus (Formosan subterranean termite).
Authors: Henderson Gregg
Published: March 2021

C. formosanus is often transported by boats and shipping containers to port cities before being carried further inland via landscape materials such as railroad ties (railway sleepers). This may explain the current C. formosanus distribution in the USA with coastal areas more densely infested than inland areas (Hochmair and Scheffrahn, 2010). Temperature and humidity are primary factors affecting the establishment of C. formosanus, and it is potentially invasive to areas of high humidity approximately 35° north and south of the equator (Su and Tamashiro, 1987). Competition from native species is another limiting factor for many exotic pests, but C. formosanus is more aggressive and is known to out-compete the endemic termites such as Reticulitermes species. Another factor that has allowed the successful establishment and spread of C. formosanus in exotic areas has been the pest control industry's heavy reliance on soil termiticide barriers for subterranean termite control since the 1950s. Numerous studies, using mark-recapture methods, have revealed that a single colony of C. formosanus might contain several million termites that forage up to 100 m in the soil (Lai, 1977; Su and Scheffrahn, 1988). These agree with the results of excavation studies for C. formosanus colonies (Ehrhorn, 1934; King and Spink, 1969). Because of the large colony size, the application of soil termiticides beneath a structure does not usually have a major impact on the overall population, and the surviving colony continues to produce alates that can further infest nearby areas. Once established, C. formosanus has never been completely eradicated from an area. The dependency of soil termiticide barriers as the primary tool for subterranean termite control is probably the main reason for the establishment and spread of C. formosanus from four isolated port cities in the 1960s in the USA to all south-eastern states by 2001.
Cornu aspersum (common garden snail).
Authors: Cowie Robert , Ansart Armelle , Madec Luc , Guiller Annie
Published: March 2021

C. aspersum, the common garden snail, is represented by several forms that are highly differentiated genetically. Only one lineage, the western one, is considered to be invasive in regions where it has been introduced recently (since the sixteenth century) either accidentally or intentionally (e.g. North and South America, South Africa, Oceania). It was in California, USA, where it was introduced in the 1850s, that it was first treated (1931) as a regulated pest. Its success in colonizing new areas after introduction and establishment may be due to: (i) large phenotypic variation in combinations of life-history traits, especially reflecting a high degree of plasticity (e.g. trade-off of egg weight/egg number), and (ii) great resistance against natural enemies. Also, genetic data indicate that C. aspersum is capable of establishing even after a severe genetic bottleneck.
Spodoptera litura (taro caterpillar).
Authors: Maes Koen
Published: March 2021

The tobacco caterpillar, S. litura, is one of the most important insect pests of agricultural crops in the Asian tropics. It is widely distributed throughout tropical and temperate Asia, Australasia and the Pacific Islands (Feakin, 1973; Kranz et al., 1977). Records of S. litura having limited distribution in (or being eradicated from) Germany, Russian Federation, Russian Far East, the UK and Réunion may in fact refer to S. littoralis. Both S. litura and S. littoralis are totally polyphagous (Brown and Dewhurst, 1975; Holloway, 1989) and therefore have huge potential to invade new areas and/or to adapt to new climatic and/or ecological situations. The Spodoptera group consists of closely related species with similar ecology that are difficult to identify to species level.
Ralstonia solanacearum (bacterial wilt of potato).
Authors: Osdaghi Ebrahim
Published: March 2021

Ralstonia solanacearum is included in the A2 (high risk) list of quarantine organisms by the European and Mediterranean Plant Protection Organization (EPPO). EPPO Code for R. solanacearum is RALSSO, while the phytosanitary categorization of the species in EPPO A2 list is no.58, EU: I/A2 (EPPO, 2018). Bacterial wilt disease was first reported in southern USA in the late nineteenth century on tomato plants (Smith, 1896). Infected plant materials (e.g. potato tubers) transmit the pathogen over long distances; hence, quarantine inspections and plant sanitary practices are the cornerstone of disease management (EPPO, 2018). R. solanacearum strains in the race 3 group are a select agent under the US Agricultural Bioterrorism Protection Act of 2002 (USDA, 2005). Peculiarly, the organism, if not yet already present in North America in pelargonium (Strider et al., 1981), was introduced with cuttings of this host by American companies producing these cuttings for their markets in countries like Kenya and Guatemala (Norman et al., 1999, 2009; Kim et al., 2002; Williamson et al., 2002; O'Hern, 2004). A similar situation led to introductions of the pathogen from Kenya into some northern European nurseries. Once the source (contaminated surface water) was recognized and proper control measures (use of deep soil water, disinfection of cutting producing premises and replacement of mother stock), the problem was solved and the disease in greenhouses eradicated (Janse et al., 2004). Similarly race 1 has been introduced into greenhouses with ornamental plants (rhizomes, cuttings or fully grown plants) such as Epipremnum, Anthurium, Curcuma spp. and Begonia eliator from tropical areas (Norman and Yuen, 1998, 1999; Janse et al., 2006; Janse, 2012). Introduction can and did occur from Costa Rica and the Caribbean, Indonesia, Thailand and South Africa. However, this idea of placing pathogens on bioterrorist list for unclear and perhaps industry-driven reasons and its effects, is strongly opposed in a recent publication from leading phytobacteriologists. This is because R. solanacearum is an endemic pathogen, causing endemic disease in most parts of its geographic occurrence, moreover normal quarantine regulations are already in place where the disease is not present or only sporadically and are thought to be more efficient and less damaging to trade and research than placing this pathogen on select agent lists and treating it as such (Young et al., 2008). Peculiarly, it has been used in the control of a real invasive species, the weed kahili ginger (Hedychium gardenarium) in tropical forests in Hawaii. This is not without risks because strains occurring on this weed host were thought to be non-virulent, but later appeared to be virulent on many edible and ornamental ginger species as well (Anderson and Gardner, 1999; Paret et al., 2008). Another threat for these countries could be strains belonging to race 1, biovar 1 (phylotype I) that have already been reported from field-grown potatoes in Portugal (Cruz et al., 2008).
Pseudomonas syringae pv. syringae (bacterial canker or blast (stone and pome fruits)).
Authors: Balestra Giorgio M
Published: March 2021

P. syringae pv. syringae occurs in many areas, from the tropics to the frigid zone (e.g. Alaska). It attacks major crops, including beans (Phaseolus vulgaris), cowpeas, stone fruits, pome fruits, kiwi fruit and grain sorghum. The diseases caused by this bacterium are very important in many countries throughout the world. For instance, bacterial brown spot occurs wherever beans are grown, and canker diseases of fruit trees caused by P. syringae pv. syringae are widespread and may be devastating, causing great losses or requiring much effort to protect plants from them.
Arion vulgaris (Spanish slug).
Authors: Anderson Roy
Published: March 2021

The invasiveness of A. vulgaris is related to several factors. Its ability and readiness to colonize humanly-disturbed environments is of major importance. Proschwitz (1997) observed that 99% of Swedish records were from synanthropic habitats and only 1% from natural woodlands. With a proximity to humans, comes the possibility of passive dispersal through trade, particularly in living plants. The garden centre trade and horticulture are particularly implicated (Weidema, 2006). In Poland, there is evidence from studies of molecular diversity that A. vulgaris has originated from repeated, separate introductions from other parts of Europe (Soroka et al., 2007). The ability of A. vulgaris to utilize a great variety of food sources and types has been well-documented and must aid dispersal and colonization. Other than its country of origin (France), it is considered to be invasive across western and central Europe, from the Pyrenees to eastern Poland and from southern France to north Italy, Austria and Slovakia and within an isolated range in eastern Bulgaria.
Policy and political consequences of mandatory climate impact assessments: an explorative study of German cities and municipalities
Authors: Rilling Benedikt , Tosun Jale
Published: March 2021

Since May 2019, several German cities and municipalities have declared a ‘climate emergency’, an action which makes climate impact assessments mandatory for all projects or policy proposals. How have the processes in the local governments changed in response to the emergency status? How have the processes in the city and municipal councils changed? And how, if at all, has the relationship between elected politicians (who make up the city and municipal councils) and bureaucrats (who make up the local government) changed? Based on 13 interviews carried out with representatives of city and municipal councils and local governments, we show, first, that local governments expect a higher workload and to spend more time on cross-sectoral coordination and cooperation. Second, the issue of climate change is now part of the political agenda in the local councils. Third, the administrative actors are now in a stronger position vis-à-vis the political ones as they can de facto veto projects or policies. Overall, we conclude that local-level climate politics has changed following the declaration of the emergency status; however, the design of the corresponding policies has not changed to reflect the cross-sectoral character of responses to climate change.
The continuum limit of quantum gravity at second order in perturbation theory
Authors: Kellett Matthew , Mitchell Alex , Morris Tim R
Published: March 2021

We show that perturbative quantum gravity based on the Einstein–Hilbert action, has a novel continuum limit. The renormalized trajectory emanates from the Gaussian fixed point along (marginally) relevant directions but enters the diffeomorphism invariant subspace only well below a dynamically generated scale. We show that for pure quantum gravity to second order in perturbation theory, and with vanishing cosmological constant, the result is the same as computed in the standard quantisation. Although this case is renormalizable at second order for kinematic reasons, the structure we uncover works in general. One possibility is that gravity has a genuine consistent continuum limit even though it has an infinite number couplings. However we also suggest a possible non-perturbative mechanism, based on the parabolic properties of these flow equations, which would fix all higher order couplings in terms of Newton’s constant and the cosmological constant.
Silicon electro-optic micro-modulator fabricated in standard CMOS technology as components for all silicon monolithic integrated optoelectronic systems
*
Authors: Xu Kaikai
Published: March 2021

In this paper, optoelectronic characteristics and related switching behavior of one monolithically integrated silicon light-emitting device (LED) with an interesting wavelength range of 400–900 nm are studied. Through the comparison of two types of geometry, Si avalanche-based LED and Si field-effect LED (Si FE LED), in the same device, we establish the dimensional dependence of the switching speed of the LED. Almost-linear modulation curve implies lower distortion is shown for the Si FE LED with light emission enhancement, and technology computer aided design (TCAD) simulations are in line with the experimental results. Our findings indicate that ON–OFF keying up to GHz frequencies should be feasible with such diodes. Potential applications should include Si FE LED integrated into the micro-photonic systems.
Microstructural analysis and electrical behaviours of co-sputtered W–Ag thin films with a tilted columnar architecture
Authors: Boukhalfa Houssem , Potin Valérie , Martin Nicolas
Published: March 2021

W–Ag thin films are produced by magnetron co-sputtering technique using glancing angle co-deposition configuration. Different samples are prepared with similar conditions (same pressure, thickness and tungsten target current) but with a variable Ag target current changing from 0 to 80 mA. The effect of the Ag target current on the film structure and electrical properties is investigated using scanning and transmission electron microscopy, energy-dispersive x-ray spectroscopy, x-ray diffraction and van der Pauw technique. Thin films with inclined columns are obtained and the columns section becomes more anisotropic for the films prepared with the lowest Ag target currents. The elemental composition of the films also changes as a function of the Ag target current, varying from tungsten-rich (at low current) to homogeneous (at high current). W–Ag thin films exhibit different crystallographic structures. If the fcc Ag phase is always present, the metastable A15 β-W is pointed out only at low Ag target current while at high current, only the bcc α-W phase is present. The microstructural analysis shows that the core of the columns is formed by W while Ag covers the columns as grains. Room temperature electrical resistivity decreases with Ag target current, whereas its anisotropy decreases. This behaviour correlates with the change in the columnar cross-section morphology.
Mechanism of transient stagnant formation in convection of binary mixtures
Authors: Kobayashi Kazuya U , Shinohara Ryoko , Kurita Rei
Published: March 2021

Two-dimensional convection rolls are usually stable near the critical Rayleigh number in single component fluids. However, in binary mixtures, it has been reported that the roll patterns become unstable over time and that stagnant domains are transiently formed. The formation of transient stagnant domains (TSD) occurs in systems where one component is more viscous than the other. Meanwhile, the mechanism of the TSD formation has been unclear yet. Here, we use experiments using well-mixed silicone oils and colloidal suspensions to show that the formation of transient stagnant regions is chiefly related to the concentration dependence of the kinematic viscosity rather than spatially averaged properties. Furthermore, we find that the concentration dependence of density is also related to the formation of stagnant regions. The coupling between density, viscosity and concentration fluctuations may play an important role for thermal convection in multi-component mixtures.
Enhancing the stability of polymer nanostructures via ultrathin oxide coatings for nano-optical device applications
Authors: Wang Yasi , Liu Peng , Shi Huimin , Dai Yutong , Zhang Jian , Zhang Jianmin , Hu Yueqiang , Duan Huigao , Chen Yiqin
Published: March 2021

Polymer nanostructures have drawn tremendous attention due to their wide applications in nanotechnology. However, the morphology of the polymer nanostructures is fragile under harsh conditions such as high-power irradiation and organic-solution environments during the fabrication or the measurement processes, significantly limiting their potential applications. In this work, we propose and demonstrate a simple approach to improve the stability of polymer nanostructures by coating a conformal ultrathin oxide film via atomic-layer deposition. Due to the refractory and dense coating of the oxide layer, the stability of polymer structures is enhanced by the prohibition of deformation occurrences from thermally induced reflow and organic solution. As a proof of concept, poly(methyl methacrylate) (PMMA) nanostructures coated with a sub-10-nm TiO2 layer are demonstrated, and the structures exhibit high temperature stability at 180 °C and good resistance to soluble damage from organic solutions. Subsequently, the mechanism of the improved thermal stability is analyzed via mechanical simulations. Such an effective approach is proposed to significantly broaden the application of polymer nanostructures as functional elements for optical structures/devices that require excellent thermal and chemical stability.
Skyrmion driven by rotary magnetic field on the surface of magnetic nanotube: a Monte Carlo study
Authors: Chi Xiaodan , Du An , Hu Yong
Published: March 2021

We report a Monte-Carlo simulation of the formation of skyrmions under a rotary magnetic field on a nanotube. The zero-field magnetic state is characterized as helical stripe domains swirling on the nanotube, with one to three periods depending on the ratio of Dzyaloshinskii–Moriya to ferromagnetic interaction and tubular size. Under a rotary magnetic field, the formation of skyrmions is in pair and the skyrmion number can be tuned. The movement of skyrmions is neither synchronous along with the rotary field, nor along a helical trajectory perpendicular to the rotary field. It is ascribed to that within a skyrmion pair, on one hand, the coupling between skyrmions is nonnegligible; on the other hand, different skyrmion pairs side by side are decoupled. This work predicts a way of nanotube-based skyrmion manipulation, and might develop the rotary information storage on energy- and space-saving modes or an edgeless racetrack memory.
Maxwellian mirages in general relativity
Authors: Williams L L , Inan N
Published: March 2021

Maxwellian approximations to linear general relativity are revisited in light of recent results on the degrees of freedom (DoF) in the linear gravitational field. The well-known Maxwellian formalism obtained in harmonic coordinates is compared with a Maxwellian formalism obtained under a coordinate choice where each of the metric components corresponds to each of the coordinate-invariant DoF of the linear gravitational field. The coordinate freedom of general relativity can be exploited to cast the field equations into Maxwellian form, but such forms can be mere mirages of the coordinate choice—mirages such as vector gravitational waves. A coordinate choice that yields perfectly-Maxwellian field equations, will yield a force equation that is not Lorentzian. If field definitions are chosen to obtain Lorentz-like terms in the force equation, then Maxwellian forms are compromised in the field equations. Many treatments of gravito-electromagnetism will make inconsistent ordering choices between the field equations and force equations, or else truncate terms of relevant order from the force equation. Often such mistakes reflect an attempt to force exact Maxwellian analogs simultaneously in both the field equations and the force equation, with the result that terms dropped are as large as those kept.
Degenerate solutions to the Dirac equation for massive particles and their applications in quantum tunneling
Authors: Tsigaridas Georgios N , Kechriniotis Aristides I , Tsonos Christos A , Delibasis Konstantinos K
Published: March 2021

In a recent work we have proven the existence of degenerate solutions to the Dirac equation, corresponding to an infinite number of different electromagnetic fields, providing also some examples regarding massless particles. In the present article our results are extended significantly, providing degenerate solutions to the Dirac equation for particles with arbitrary mass, which, under certain conditions, could be interpreted as pairs of particles (or antiparticles) moving in a potential barrier with energy equal to the height of the barrier and spin opposite to each other. We calculate the electromagnetic fields corresponding to these solutions, providing also some examples regarding both spatially constant electromagnetic fields and electromagnetic waves. Further, we discuss some potential applications of our work, mainly regarding the control of the particles outside the potential barrier, without affecting their state inside the barrier. Finally, we study the effect of small perturbations to the degenerate solutions, showing that our results are still valid, in an approximate sense, provided that the amplitude of the electromagnetic fields corresponding to the exact degenerate solutions is sufficiently small.
ANTARES upper limits on the multi-TeV neutrino emission from the GRBs detected by IACTs
Authors: Albert A. , André M. , Anghinolfi M. , Anton G. , Ardid M. , Aubert J.-J. , Aublin J. , Baret B. , Basa S. , Belhorma B. , Bertin V. , Biagi S. , Bissinger M. , Boumaaza J. , Bouta M. , Bouwhuis M.C. , Brânzaş H. , Bruijn R. , Brunner J. , Busto J. , Capone A. , Caramete L. , Carr J. , Carretero V. , Celli S. , Chabab M. , Chau T.N. , Cherkaoui El Moursli R. , Chiarusi T. , Circella M. , Coleiro A. , Colomer-Molla M. , Coniglione R. , Coyle P. , Creusot A. , Díaz A.F. , de Wasseige G. , Deschamps A. , Distefano C. , Di Palma I. , Domi A. , Donzaud C. , Dornic D. , Drouhin D. , Eberl T. , El Khayati N. , Enzenhöfer A. , Ettahiri A. , Fermani P. , Ferrara G. , Filippini F. , Fusco L. , García R. , Gay P. , Glotin H. , Gozzini R. , Graf K. , Guidi C. , Hallmann S. , van Haren H. , Heijboer A.J. , Hello Y. , Hernández-Rey J.J. , Hößl J. , Hofestädt J. , Huang F. , Illuminati G. , James C.W. , Jisse-Jung B. , de Jong M. , de Jong P. , Jongen M. , Kadler M. , Kalekin O. , Katz U. , Khan-Chowdhury N.R. , Kouchner A. , Kreykenbohm I. , Kulikovskiy V. , Lahmann R. , Le Breton R. , Lefèvre D. , Leonora E. , Levi G. , Lincetto M. , Lopez-Coto D. , Loucatos S. , Maderer L. , Manczak J. , Marcelin M. , Margiotta A. , Marinelli A. , Martínez-Mora J.A. , Mazzou S. , Melis K. , Migliozzi P. , Moser M. , Moussa A. , Muller R. , Nauta L. , Navas S. , Nezri E. , Nuñez-Castiñeyra A. , O'Fearraigh B. , Organokov M. , Păvălaş G.E. , Pellegrino C. , Perrin-Terrin M. , Piattelli P. , Pieterse C. , Poirè C. , Popa V. , Pradier T. , Randazzo N. , Reck S. , Riccobene G. , Sánchez-Losa A. , Samtleben D.F.E. , Sanguineti M. , Sapienza P. , Schnabel J. , Schüssler F. , Spurio M. , Stolarczyk Th. , Taiuti M. , Tayalati Y. , Thakore T. , Tingay S.J. , Vallage B. , Van Elewyck V. , Versari F. , Viola S. , Vivolo D. , Wilms J. , Zegarelli A. , Zornoza J.D. , Zúñiga J.
Published: March 2021

The first gamma-ray burst detections by Imaging Atmospheric
Cherenkov Telescopes have been recently announced: GRB 190114C,
detected by MAGIC, GRB 180720B and GRB 190829A, observed by
H.E.S.S. A dedicated search for neutrinos in space and time
coincidence with the gamma-ray emission observed by IACTs has been
performed using ANTARES data. The search covers both the prompt and
afterglow phases, yielding no neutrinos in coincidence with the
three GRBs studied. Upper limits on the energetics of the neutrino
emission are inferred. The resulting upper limits are several orders
of magnitude above the observed gamma-ray emission, and they do not
allow to constrain the available models.
Entanglement entropy of cosmological perturbations for S-brane Ekpyrosis
Authors: Brahma Suddhasattwa , Brandenberger Robert , Wang Ziwei
Published: March 2021

We calculate the entanglement entropy of scalar perturbations due to gravitational non-linearities present in any model of canonically-coupled, single-field ekpyrosis. Specifically, we focus on a recent model of improved ekpyrosis which is able to generate a scale-invariant power spectrum of curvature perturbations and gravitational waves as well as have a non-singular bounce due to an S-brane at the end of ekpyrotic contraction. By requiring that the entanglement entropy remians subdominant to the thermal entropy produced during reheating, we get an upper bound on the energy scale of the bounce.
Ray-tracing log-normal simulation for weak gravitational lensing: application
to the cross-correlation with galaxies
Authors: Makiya Ryu , Kayo Issha , Komatsu Eiichiro
Published: March 2021

We present an algorithm to self-consistently generate mock weak gravitational lensing convergence fields and galaxy distributions in redshift space. We generate three-dimensional cosmic density fields that follow a log-normal distribution, and ray-trace them to produce convergence maps. As we generate the galaxy distribution from the same density fields in a manner consistent with ray-tracing, the galaxy-convergence cross-power spectrum measured from the mock agrees with the theoretical expectation with high precision.
We use this simulation to forecast the quality of galaxy-shear cross-correlation measurements from the Subaru
Hyper Suprime-Cam (HSC) and Prime Focus Spectrograph (PFS) surveys.
We find that the nominal HSC and PFS surveys would detect the cross power spectra with signal-to-noise ratios of 20 and 5 at the lowest (z = 0.7) and highest (z = 2.2) redshift bins, respectively.
Energy conditions allow eternal inflation
Authors: Kontou Eleni-Alexandra , Olum Ken D.
Published: March 2021

Eternal inflation requires upward fluctuations of the energy in a
Hubble volume, which appear to violate the energy conditions. In
particular, a scalar field in an inflating spacetime should obey the
averaged null energy condition, which seems to rule out eternal
inflation. Here we show how eternal inflation is possible when energy
conditions (even the null energy condition) are obeyed. The critical
point is that energy conditions restrict the evolution of any single
quantum state, while the process of eternal inflation involves
repeatedly selecting a subsector of the previous state, so there is no
single state where the conditions are violated.
How warm are non-thermal relics? Lyman-α bounds on out-of-equilibrium dark matter
Authors: Ballesteros Guillermo , Garcia Marcos A.G. , Pierre Mathias
Published: March 2021

We investigate the power spectrum of Non-Cold Dark Matter (NCDM) produced in a state out of thermal equilibrium. We consider dark matter production from the decay of scalar condensates (inflaton, moduli), the decay of thermalized and non-thermalized particles, and from thermal and non-thermal freeze-in. For each case, we compute the NCDM phase space distribution and the linear matter power spectrum, which features a cutoff analogous to that for Warm Dark Matter (WDM). This scale is solely determined by the equation of state of NCDM. We propose a mapping procedure that translates the WDM Lyman-α mass bound to NCDM scenarios. This procedure does not require expensive ad hoc numerical computations of the non-linear matter power spectrum. By applying it, we obtain bounds on several NCDM possibilities, ranging from m
DM ≳ EeV for DM production from inflaton decay with a low reheating temperature, to sub-keV values for non-thermal freeze-in. We discuss the phenomenological implications of these results for specific examples which include strongly-stabilized and non-stabilized supersymmetric moduli, gravitino production from inflaton decay, Z' and spin-2 mediated freeze-in, and non-supersymmetric spin-3/2 DM.
Conversion of spin and orbital angular momentum in the third harmonic generation process in the bulk of an isotropic medium
Authors: Grigoriev K S , Diukov V A , Makarov V A
Published: March 2021

The interaction between spin and orbital components of the angular momentum of an elliptically polarized beam with helicoidal phase profile and arbitrary axially symmetric intensity profile in the third-harmonic generation process is investigated. The third-harmonic beam is generated in an isotropic medium with cubic nonlinearity within undepleted pump approximation. The conservation of the total projections of both the spin angular momentum and orbital angular momentum components in four-wave mixing is demonstrated for interacting waves.
Subject- and task-independent neural correlates and prediction of decision confidence in perceptual decision making
Authors: Fernandez-Vargas Jacobo , Tremmel Christoph , Valeriani Davide , Bhattacharyya Saugat , Cinel Caterina , Citi Luca , Poli Riccardo
Published: March 2021

Objective. In many real-world decision tasks, the information available to the decision maker is incomplete. To account for this uncertainty, we associate a degree of confidence to every decision, representing the likelihood of that decision being correct. In this study, we analyse electroencephalography (EEG) data from 68 participants undertaking eight different perceptual decision-making experiments. Our goals are to investigate (1) whether subject- and task-independent neural correlates of decision confidence exist, and (2) to what degree it is possible to build brain computer interfaces that can estimate confidence on a trial-by-trial basis. The experiments cover a wide range of perceptual tasks, which allowed to separate the task-related, decision-making features from the task-independent ones. Approach. Our systems train artificial neural networks to predict the confidence in each decision from EEG data and response times. We compare the decoding performance with three training approaches: (1) single subject, where both training and testing data were acquired from the same person; (2) multi-subject, where all the data pertained to the same task, but the training and testing data came from different users; and (3) multi-task, where the training and testing data came from different tasks and subjects. Finally, we validated our multi-task approach using data from two additional experiments, in which confidence was not reported. Main results. We found significant differences in the EEG data for different confidence levels in both stimulus-locked and response-locked epochs. All our approaches were able to predict the confidence between 15% and 35% better than the corresponding reference baselines. Significance. Our results suggest that confidence in perceptual decision making tasks could be reconstructed from neural signals even when using transfer learning approaches. These confidence estimates are based on the decision-making process rather than just the confidence-reporting process.
Decoding of semantic categories of imagined concepts of animals and tools in fNIRS
Authors: Rybář Milan , Poli Riccardo , Daly Ian
Published: March 2021

Objective. Semantic decoding refers to the identification of semantic concepts from recordings of an individual’s brain activity. It has been previously reported in functional magnetic resonance imaging and electroencephalography. We investigate whether semantic decoding is possible with functional near-infrared spectroscopy (fNIRS). Specifically, we attempt to differentiate between the semantic categories of animals and tools. We also identify suitable mental tasks for potential brain–computer interface (BCI) applications. Approach. We explore the feasibility of a silent naming task, for the first time in fNIRS, and propose three novel intuitive mental tasks based on imagining concepts using three sensory modalities: visual, auditory, and tactile. Participants are asked to visualize an object in their minds, imagine the sounds made by the object, and imagine the feeling of touching the object. A general linear model is used to extract hemodynamic responses that are then classified via logistic regression in a univariate and multivariate manner. Main results. We successfully classify all tasks with mean accuracies of 76.2% for the silent naming task, 80.9% for the visual imagery task, 72.8% for the auditory imagery task, and 70.4% for the tactile imagery task. Furthermore, we show that consistent neural representations of semantic categories exist by applying classifiers across tasks. Significance. These findings show that semantic decoding is possible in fNIRS. The study is the first step toward the use of semantic decoding for intuitive BCI applications for communication.
The improvement of visual object tracking using a combination between particle and correlation filter
Authors: Habibi Yabunayya , Muniri
Published: March 2021

One of the many challenging problems from computer vision is constructing robust object tracking from various problems and object conditions. Difficulties in tracking are more complex when an image sequence has many types of tracking problems such as background clutter, fast motion, occlusion, illumination variance, scale variance, motion blur, non-rigid object pattern, and another. Meanwhile, the task to build a novel approach which efficiently handle all tracking problems still in development step, especially supported by low computing time. We combine adaptive particle filters (APF) and discriminative correlation filters (DCF) to overcome more complex tracking problems so it can improve overall tracking accuracy. Our combination employs APF as the main framework and embeds DCF in it to estimate motion vector. However, this will make a double-edged knife where the utilization of two approaches together will make enlarged computing time. So, we also utilize leap-tracking as an alternative solution to reduce high computation time. Our testing uses 15 sets of benchmarks tracking datasets and 3 sets by ourselves with various tracking problems. The results show that our combination significantly improves tracking accuracy. Thus, the reducing of computational procedures efficiently will increases tracker speed without reduces accuracy and avoids identification errors.
Likelihood ratio test for the adequacy of a regression model when the noise is given by the Slepian field
Authors: Somayasa Wayan
Published: March 2021

In this paper we establish a non parametric likelihood ratio (LR) test procedure for testing the mean of a regression or additive model when the disturbance is represented by the Slepian field. By utilizing the Cameron-Martin-Girsanov formula and the fundamental theorem of projection, we get the likelihood estimator of the mean function under either H
0 or H
1 as the projection of the random observation. By applying the fundamental characteristic of the Slepian field for a typical size of the moving rectangle, it is shown under H
0 that the probability distribution of the test statistic belongs to the family of a central chi-square distributions, whereas under H
1 it is distributed as a noncentral chi-square. Furthermore, by simulating a type of Fourier model, the empirical power function of the test shows that the proposed test is consistent in the sense it maximizes the probability of the rejection when the model is not true.
The comparison between extreme learning machine and artificial neural network-back propagation for predicting the dengue incidences number in DKI Jakarta
Authors: Tiffany S , Sarwinda D , Handari B D , Hertono G F
Published: March 2021

The existence of COVID-19 in Indonesia is not the only disease which we must be aware of. The Health Ministry has said that Dengue Hemorrhagic Fever is as dangerous as COVID-19 and must also be treated with caution. Based on data, until July 2020, there are 71,633 dengue cases in Indonesia and DKI Jakarta has the sixth-highest dengue incidence number. One of the factors that affects the spread of dengue vector is weather. It is necessary to predict the number of dengue incidences so that the dengue handling and prevention efforts can be done optimally. In this study, the number of dengue incidences will be predicted by involving weather factors (rainfall, temperature, and humidity) using Extreme Learning Machine and Artificial Neural Network-Back Propagation and also comparing the both of their performance. The result shows that Extreme Learning Machine can give the dengue incidence prediction in DKI Jakarta with the best RMSE testing result of 0.04584, which is more accurate than the dengue incidence prediction that is given by using Artificial Neural Network-Back Propagation with 100 epochs. Moreover, Extreme Learning Machine can do the training process faster than Artificial Neural Network-Back Propagation.
Discovering Unusual Periodically Human Activity Patterns Through Fuzzy High Utility Rare Itemsets Mining
Authors: Ushio Soma , Iqbal Mohammad , Mukhlash Imam
Published: March 2021

Monitoring the resident activities is a key goal to build a safe and convenient environment in a smart house system. One way to capture the activity is by installing motion sensors around the house. By collecting the triggered sensor state, we attempt to find unusual activity patterns to notify suspicious movements or health issues information as our main goals. This study focuses to express the nature of time interval of each activity more clearly using fuzzy set. Next, this study employs fuzzy high utility rare itemsets mining to obtain some odd activities with different quantity of time intervals. Hence, we can determine how peculiar the activity. In this study, we analyzed the public human activity recognition dataset based on each single resident and their activities. As the results, we successfully catch the uncommon activity compared to the daily ones either fishy movements or sick, the illogical movement order, and the false alarm due to the limitation of sensor transmission.
Modelling and Verification of Cash Withdrawal Transaction in Automated Teller Machine Using Timed Automata
Authors: Hendrawan Ari Ramadhana , Adzkiya Dieky
Published: March 2021

This study was conducted to verify a system of Automated Teller Machine (ATM) which is a facility provided by a bank. Various transactions can be done by using ATM, including cash withdrawal, payment, and transfer. However, in spite of its function, ATM can also be a target of crime such as cash robbery and frauds. Therefore, the correctness of ATM and its security is essential and for that reason, formal verification is needed. Formal verification is a technique to ensure the model of a system to satisfy a certain specification. ATM has a time variable on its system. Therefore, timed automata can be used as a model of ATM. In this paper, an algorithm is constructed based on the ATM cash withdrawal steps. Next, we construct a timed automaton model and design nine specifications. Then, timed automaton were verified against these nine specifications using UPPAAL. From the verification results, it can be concluded that the security of the ATM system is guaranteed.
Study numerical scheme of finite difference for solution partial differential equation of parabolic type to heat conduction problem
Authors: Hanafi L , Mardlijah M , Utomo D B , Amiruddin A
Published: March 2021

The mathematical formulation of heat conduction problem along the rod involving rates of change with respect to two independent variablels, namely time and length leads to a partial differential equation of parabolic type. The initial and boundaries conditions are known. Finite difference approximations are used as a numerical method approach how to solve heat conduction problem. In this paper, numerical scheme of finite difference should be applied to construct and compute the temperature within a rod by explicit method, implicit method and Crank-Nicolson method.
Latent Class Cluster for Clustering Villages Based on Socio-economic Indicators in 2018
Authors: Riyanto A , Kuswanto H , Prastyo D D
Published: March 2021

Latent class analysis (LCA) is a statistical method used to classify units into unobserved (latent) variable classes, so-called clusters. In this article, we introduce LCA to demonstrate its use for village groupings. We applied LCA on data processed from the census conducted by BPS-Statistics Indonesia, namely the village potential (Podes) data 2018. The Podes data is used to extract the socio-economic characteristics of a village. The empirical results of the LCA application show that the villages in the Banyumas Regency are grouped into three classes/clusters.
Spatio-Temporal models with intervention effect for modelling the impact of Covid-19 on the tourism sector in Indonesia
Authors: Prastuti M , Aridinanti L , Dwiningtyas W P
Published: March 2021

Coronavirus is a virus that attacks the respiratory system, this disease due to viral infection is called Covid-19. Since it was found at December 2019 in China, the Covid-19 outbreak has spreads to several countries, one of them is Indonesia. This causes the tourism sector in Indonesia to decline drastically. Therefore, this study aims to analyze the impact of Covid-19 outbreak on the number of foreign tourist arrivals to Indonesia especially in Jakarta, Bali, and Surabaya. This data is ordered by times from several different locations and has a relationship with each other or is called spatio-temporal data. Furthermore, the data will be added the intervention variable is time where the covid-19 outbreak found in December 2019. The data will be analyzed using a spatio-temporal models. The result shows that seasonal GSTARX-GLS models tend to give more accurate forecast than VARX and seasonal GSTARX-OLS models.
Comparison of Ensemble Kalman Filter, Unscented Kalman Filter, and Fractional Kalman Filter for estimating the concentration of CO and NO
2
Authors: Prakosa S E , Lestari D D , Dianawati R , Apriliani E , Arif D K , Herisman I , Akbar M S
Published: March 2021

Estimation distribution of air pollution is necessary to determine the level of pollution in a location so it can be used to recommend emission minimization. This research use some modification of Kalman Filter method for estimation distribution of air pollution. Three estimation methods namely Fractional Kalman Filter (FKF), Ensemble Kalman Filter (EnKF), Unscented Kalman Filter (UKF). The simulation result of three methods will be compared. Distribution of carbon monoxide and nitrogen dioxide in Surabaya was estimated using three methods. This reserach showed that Fractional Kalman Filter method is the best estimator among the others because error value is the smallest.
Cat bond valuation using Monte Carlo and quasi Monte Carlo method
Authors: Siyamah Imroatus , Putri Endah RM , Imron Chairul
Published: March 2021

The frequency of natural disasters is very small, but the loss of damage and the risks that must be borne is of enormous value. Recently, Catastrophe bond (CAT bond) has grown rapidly in financial markets to increase the coverage of environmental disasters and the resulting economic losses, insurance companies and reinsurers are barely covered. Catastrophe bond (CAT Bond) is one of the insurance-linked financial securities instruments that aim to transfer risk by insuring natural disaster events to the capital market. The model of natural disaster loss without a jump-diffusion process followed a model of geometric Brownian motion. We estimate and match each parameter in each model by using grid search and then we use the method of Monte Carlo and quasi-Monte Carlo to obtain numerical results for the CAT bonds pricing formulas. From this simulation, the Monte Carlo method has good enough accuracy and efficiency to valuates the CAT bond. Less then 500 iterations Monte Carlo have reached convergence in 1280.49 seconds. And quasi-Monte Carlo more efficient with less than 400 iterations have reached convergence in 30.89 seconds. Both methods have reached small enough MAPE. Based on the simulations carried out through this research, it was showed that the quasi-Monte Carlo method is better than the Monte Carlo method based on the value of Mean Absolute Percentage Error (MAPE) and running time.
Sentiment analysis and topic modeling of BPJS Kesehatan based on twitter crawling data using Indonesian Sentiment Lexicon and Latent Dirichlet Allocation algorithm
Authors: Dikiyanti T D , Rukmi A M , Irawan M I
Published: March 2021

In today’s era, company performance is influenced by quick and easy responses to interacting with users. Twitter is one of the social media which is believed that public opinion on Twitter can influence the government or companies to make policies. Public criticism on Twitter is more quickly responded than people who contacting customer service directly, this is because the companies or government do not want their image to be bad due to delays in responding to public complaints on Twitter. Studies related to opinion writing on social media can use the method of topic modeling and sentiment analysis in order to get what topics are currently being discussed and also the value of their sentiments. Modeling of the topic was carried out using Latent Dirichlet Allocation and sentiment analysis using the Indonesian Sentiment Lexicon. A case study of public opinion on BPJS Kesehatan using Twitter data for 3 months from February to April 2020, obtained 5 main topics with the BPJS Kesehatan’s New Contribution Rate as a trending topic with a sentiment value of 61.7% positive and 38.3% negative.
Application of Pascoletti-Serafini scalarization modification method to solve multi-objective optimization problems for stock portfolio
Authors: Mustika M , Mulyawati T , Apriyanto D K , Sausan A , Rofikah
Published: March 2021

One example of a multi-objective optimization problem is stock portfolio management. There are at least two objective functions to be achieved simultaneously, namely to maximize returns and minimize risk. The desire to maximize return and minimize risk are conflicting objectives. In this study, the problem of multi-objective optimization in the selection of Islamic stock portfolios will use the Pascoletti-Serafini scalarization modification method. Furthermore, the solution to the multi objective optimization problem is known as the Pareto optimal solution or efficient solution. In the Pascoletti-Serafini scalarization modification method, a set of Pareto optimal solutions can be constructed so that not only one solution is offered to decision makers, but a set of Pareto optimal solutions. From this research, the results obtained in the form of a set of efficient solutions that can be used as investor preferences in choosing the optimal stock portfolio.
Jacobi multipliers and Hamel’s formalism
Authors: Cariñena José F , Santos Patricia
Published: March 2021

In this work we establish the relation between the Jacobi last multiplier, which is a geometrical tool in the solution of problems in mechanics and that provides Lagrangian descriptions and constants of motion for second-order ordinary differential equations, and nonholonomic Lagrangian mechanics where the dynamics is determined by Hamel’s equations.
The Influence of Nonlinear Deformation-Wave Processes Induced by Seismic Effects on the Gas-Dynamic Activity of Coal Mines
Authors: Kiryaeva T A , Oparin V N
Published: March 2021

Starting in 1834, the article gives a historical review of the influence of nonlinear deformation-wave processes, including those induced by seismic effects, on the gas-dynamic activity of coal mines. Hypotheses that differ in respect to the role of gas, rock pressure or tectonic stresses in the excitation and development of sudden outbursts in Russia and abroad, as well as the interpretation of these hypotheses from a modern point of view, are considered. It is shown that there is a deterministic connection between nonlinear deformation-wave processes induced by natural-technogenic earthquakes and propagating in rock masses in the form of packets of pendulum waves of the “quasimeter” (0.11 ÷ 1 m / s) velocity range, and modes of increased gas-dynamic activity coal mines of Kuzbass.