bluuebunny/crossref_metadata_2025 huggingface dataset:
On the propagation of electrostatic wave modes in the inhomogeneous ionospheric plasma of Venus
Authors: Fayad A. A. , Elkamash I. S. , Fichtner H. , Lazar M. , El-Labany S. K. , Moslem W. M.
Published: August 2021

The influence of gradients of number density, magnetic field, and flow velocity in a plasma on the propagation of low-frequency electrostatic waves is investigated in plasma conditions relevant for the Venusian ionosphere (vicinity of Venus terminator). For this purpose, we assume a collisionless inhomogeneous plasma model consisting of two positive ion species, hydrogen H+ and oxygen O+, as well as neutralizing electrons. Linear dispersion relations predict two types of plasma modes, namely, ion-acoustic mode and drift mode. It is found that these modes have relatively long wavelengths, extending to 10 km and frequencies on the order of ∼10−3−10−2 Hz. The characteristics of these modes show a strong dependence on the gradients of plasma parameters, and numerical analysis reveals that the coupling of these modes may lead to nonlinear instabilities. However, unstable modes occur only when the field-aligned shear flows are introduced. These results help explain the presence of low-frequency electrostatic modes and their basic features in the Venusian ionosphere, and will allow future studies to extend modeling to other planetary or even cometary conditions.
Bandgap engineering of stacked two-dimensional polyaniline by twist angle
Authors: Kang Dawei , Zuo Zheng-Wei , Wang Zhaowu , Ju Weiwei
Published: August 2021

Stacking two-dimensional materials vertically by van der Waals interaction is a promising approach to realize band structure engineering. Recently, layered two-dimensional materials with adjusted twist angle provide a platform for various novel phenomena. By means of density functional theory and tight-binding modeling, we investigate the bilayer polyaniline (PANI) as a prototype to explore the bandgap tuning mechanism by interlayer twist. A wider and continuous bandgap tuning is found in twisted bilayer PANI compared with the tuning by interlayer translation. The unique bandgap tuning by twist angle can be understood by fast exponential decaying of interlayer coupling strength, twist angle dependent interlayer coupling patterns, and charge transfer effect. These findings might provide an efficient bandgap tuning method by twist angle in 2D layered materials, which is the key to applications in electronic and optical devices.
Magnetic domains and unusual hysteresis loops of yttrium iron garnet crystals revealed by magneto-optic effects
Authors: Zhu X. D.
Published: August 2021

I present a magneto-optic effect study of magnetic domains in a ferrimagnetic yttrium iron garnet crystal at different stages of a hysteresis loop. By measuring the Faraday effect in response to the out-of-plane component and Kerr effects to the in-plane components of the sample magnetization, I examined the evolution of magnetic domains during a hysteresis loop in an in-plane external magnetic field. I found that crystalline anisotropy, magneto-static energy, and the presence of movable domain walls play indispensable roles in the domain orientation, particularly when the external field is near zero, and have led to seemingly unusual appearances of hysteresis loops.
Local molecular probes of ultrafast relaxation channels in strongly coupled metalloporphyrin-cavity systems
Authors: Avramenko Aleksandr G. , Rury Aaron S.
Published: August 2021

The quantum control of ultrafast excited state dynamics remains an unachieved goal within the chemical physics community. In this study, we assess how strongly coupling to cavity photons affects the excited state dynamics of strongly coupled zinc (II) tetraphenyl porphyrin (ZnTPP) and copper (II) tetraphenyl porphyrin (CuTPP) molecules. By varying the concentration of each chromophore within different Fabry–Pérot (FP) structures, we control the collective vacuum Rabi splitting between the energies of cavity polariton states formed through the strong coupling of molecular electrons and cavity photons. Using ultrafast transient reflectivity and transmission measurements probing optical transitions of individual ZnTPP and CuTPP molecules, we find that the polaritonic states localize into uncoupled excited states of these chromophores through different mechanisms. For ZnTPP, we build a simple kinetic model including a direct channel of relaxation between the polaritonic states. We find that our models necessitate a small contribution from this interpolaritonic relaxation channel to explain both our steady-state and transient optical spectroscopic measurements adequately. In contrast, we propose that strong cavity coupling slows the internal conversion between electronic states of CuTPP not directly interacting with the photons of FP structures. These results suggest that researchers must consider the vibrational structure and excited state properties of the strongly coupled chromophores when attempting to use polariton formation as a tool to control the dynamics of molecules central to photo-sensitizing and light harvesting applications.
Fast attenuation of high-frequency acoustic waves in bicontinuous nanoporous gold
Authors: Zheng Q. , Tian Y. , Shen X. , Sokolowski-Tinten K. , Li R. K. , Chen Z. , Mo M. Z. , Wang Z. L. , Liu P. , Fujita T. , Weathersby S. P. , Yang J. , Wang X. J. , Chen M. W.
Published: August 2021

We studied the formation and attenuation of GHz elastic waves in free-standing nanoporous gold films by MeV ultrafast electron diffraction and finite element simulations. By tracing the evolution of the high frequency acoustic waves in time domain, we found that the bicontinuous nanoporous structure in nanoporous gold films results in three-dimensionally acoustic response with low coherence, leading to fast attenuation of the elastic waves in comparison with solid gold films. The morphologically dominated dynamics indicates the nanoporosity plays an important role in the high-frequency acoustic energy relaxation, which shines a light on the applications of dealloyed nanoporous materials in nanodevices and sensors as GHz and THz acoustic filters and dampers.
Scattering theory for Dirac fields inside a Reissner–Nordström-type black hole
Authors: Häfner Dietrich , Mokdad Mokdad , Nicolas Jean-Philippe
Published: August 2021

We show asymptotic completeness for the massive charged Dirac equation between the black hole and Cauchy horizons of a sub-extremal [(anti-)de Sitter]–Reissner–Nordström black hole.
Metal-doped KNbO3 for visible light photocatalytic water splitting: A first principles investigation
Authors: Maarouf Ahmed A. , Gogova D. , Fadlallah Mohamed M.
Published: August 2021

Materials suitable for visible light photocatalytic water splitting provide sustainable green energy production and environmental pollution solution. Potassium niobate, KNbO3, is not widely used in photocatalytic applications because of its large bandgap, which is not appropriate for the visible range of the solar spectrum. However, doping of semiconductors may help reduce their bandgaps by pinning a dopant level near the top/bottom of the valence/conduction band. We employ first-principles calculations to gain insight into the electronic and optical properties of KNbO3 doped with a number of 3d and 4d transition metals to design and enhance its photocatalytic behavior. We demonstrate the substitutional doping with these elements at the Nb site decreases the bandgap and improves the optical and photocatalytic activities of KNbO3. Our calculations prove that the best candidates for water splitting and CO2 gas reduction are Ag- and Mn-doped KNbO3, respectively. Computational outcomes are compared and discussed with existing experimental ones for doped KNbO3 and KTaO3 structures. Meanwhile, we found out Tc-doped KNbO3 can be beneficial for spintronic applications. The results achieved in this study will initiate a number of experimental investigations for the full exploration of the cubic perovskites, especially in green energy production.
An orbital picture extracted from correlated electronic wavefunctions and application to forbidden reactions: 70 years of the frontier orbital theory
Authors: Takatsuka Kazuo , Arasaki Yasuki
Published: August 2021

The one-electron picture in molecular electronic state theory, particularly the molecular orbital (MO) theory with the Hartree–Fock approximation, has set a foundation to develop chemical science. Frontier orbital theory, or the theory of HOMO (highest occupied MO)–LUMO (lowest unoccupied MO) interaction, and the conservation rule of orbital symmetry are among the brightest achievements in a molecular orbital picture. After 70 years from the birth of frontier orbital theory, however, electronic wavefunctions treated in current quantum chemistry are often highly correlated and consist of extensive scales of electronic configurations to be more accurate and to cope with far more complicated reactions than concerted reactions. Under such circumstances, the MO approximation itself readily loses its validity, let alone the utter dominance of the HOMO–LUMO interaction. Recently, we have proposed an invariant method to extract general orbitals from such correlated electronic wavefunctions, which we refer to as Energy Natural Orbitals (ENOs) [K. Takatsuka and Y. Arasaki, J. Chem. Phys. 154, 094103 (2021)]. The energies of ENOs are summed exactly to the total electronic energy. The topological (symmetry) properties of a total wavefunction are represented by the relative phases of ENOs along with the continuity and crossing (avoided and conical intersection) among them. Only a small number of ENOs often dominate and characterize chemical reactions. With these properties of ENO, we explore a couple of simple and typical symmetry forbidden reactions, illustrating the effects of electron correlation and degeneracy in relevant ENOs. We propose the notion of “internal conical intersection” among ENOs, which leads to Jahn–Teller effect, pseudo-Jahn–Teller effect, and so on. We dare to explain the primary origin of elementary conical intersections and multidimensional avoided crossing in chemical reactions with the use of the notion of orbital crossing between those of HOMO–HOMO and LUMO–LUMO interactions and so on.
Toward the design of chemical reactions: Machine learning barriers of competing mechanisms in reactant space
Authors: Heinen Stefan , von Rudorff Guido Falk , von Lilienfeld O. Anatole
Published: August 2021

The interplay of kinetics and thermodynamics governs reactive processes, and their control is key in synthesis efforts. While sophisticated numerical methods for studying equilibrium states have well advanced, quantitative predictions of kinetic behavior remain challenging. We introduce a reactant-to-barrier (R2B) machine learning model that rapidly and accurately infers activation energies and transition state geometries throughout the chemical compound space. R2B exhibits improving accuracy as training set sizes grow and requires as input solely the molecular graph of the reactant and the information of the reaction type. We provide numerical evidence for the applicability of R2B for two competing text-book reactions relevant to organic synthesis, E2 and SN2, trained and tested on chemically diverse quantum data from the literature. After training on 1–1.8k examples, R2B predicts activation energies on average within less than 2.5 kcal/mol with respect to the coupled-cluster singles doubles reference within milliseconds. Principal component analysis of kernel matrices reveals the hierarchy of the multiple scales underpinning reactivity in chemical space: Nucleophiles and leaving groups, substituents, and pairwise substituent combinations correspond to systematic lowering of eigenvalues. Analysis of R2B based predictions of ∼11.5k E2 and SN2 barriers in the gas-phase for previously undocumented reactants indicates that on average, E2 is favored in 75% of all cases and that SN2 becomes likely for chlorine as nucleophile/leaving group and for substituents consisting of hydrogen or electron-withdrawing groups. Experimental reaction design from first principles is enabled due to R2B, which is demonstrated by the construction of decision trees. Numerical R2B based results for interatomic distances and angles of reactant and transition state geometries suggest that Hammond’s postulate is applicable to SN2, but not to E2.
Typology and diachrony of converbs in Indo-Aryan
Authors: Stroński Krzysztof , Kulikov Leonid
Published: August 2021

Non-finite forms constitute an important component of the verbal system of Indo-Aryan (IA) languages. On the one
hand, some of them, such as e.g., converbs, have already received proper attention in historical linguistics and typological
literature, with regard to Old Indo-Aryan (OIA), Middle Indo-Aryan (MIA) and New Indo-Aryan (NIA) (cf. Tikkanen 1987; Peterson 1998; Subbarao 2012 among others). Other forms, such as participles, have usually been analysed in the wider
context of reorganisation of a finite verbal system which led to alignment change (for recent discussion see Dahl and Stroński 2016). On the other hand, adverbial participles or infinitives have so far been
under-studied (cf. Sigorski 2005), particularly within early NIA. This period in the
history of IA languages witnessed several important morphosyntactic developments and still requires in-depth study, particularly
due to the lack of well-edited corpora. The aim of the present paper is to partly fill this gap by highlighting major trends in
the development of constructions based on various non-finite forms in early NIA. We focus on main argument marking in converbal
chain constructions and its interplay with the animacy hierarchy. We demonstrate a relative stability of differential case marking
(DCM), focusing mainly on conditions on differential subject marking (DSM) and differential object marking (DOM). In addition, we
compare converbal chain constructions with participial absolute constructions (AC). Finally, in order to give a holistic view of
converbal constructions, we verify the type of linking instantiated by them, focusing on three scopal parameters in converbal
constructions (Tense, Illocutionary Force and Negation) and using the apparatus of Role and Reference Grammar and Multivariate
Analysis.
The 12‐lead electrocardiogram of the elite female footballer as defined by different interpretation criteria across the competitive season
Authors: Morrison Barbara , Mohammad Aleah , Oxborough David , Somauroo John , Lindsay Sarah , Drane Aimee L. , Shave Rob , George Keith
Published: August 2021

Pre‐participation screening (PPS), using a 12‐lead electrocardiogram (ECG), is recommended to identify athletes at risk of sudden cardiac death (SCD). ECG interpretation criteria have been developed to address the concern arising from high false‐positives in athletes. There are limited ECG data in elite female footballers. The aims of this study were to (1) compare the ECG outcomes using three published ECG criteria (European Society of Cardiology [ESC], Seattle, International) in elite female footballers and (2) compare ECG data at three different stages of a competitive season. Eighty‐one elite female footballers (21 ± 4 yr) completed a medical assessment, anthropometrics, resting blood pressure and a resting 12‐lead ECG. Each 12‐lead ECG was interpreted in accordance with (1) ESC; (2) Seattle; (3) International Criteria to determine training‐related and non‐training‐related ECG changes. A subset of thirteen (26 ± 4 yr) footballers had repeated resting ECG tests at three time points across the competitive season. Eighty percent of females had training‐related ECG patterns. Sinus bradycardia (65%) and early repolarization (42%) were the most common. Using the ESC Criteria 25% (20/81) of the athletes were considered to have an abnormal ECG, compared to 0% using the Seattle and International Criteria, mainly due to alterations in QT length criteria. There were no clinically significant differences in ECG data across a competitive season. The Seattle and International ECG Criteria significantly reduced the number of ECG false‐positives in elite female footballers and the time point of PPS within a competitive season is unlikely to alter the PPS outcomes.

Abbreviations: AMSSM: American Medical Society for Sports Medicine; ANOVA: Analysis of Variance; BSA: Body Surface Area; ECG: Electrocardiogram; ESC: European Society of Cardiology; FA: Football Association; FIFA: The Fédération Internationale de Football Association (FIFA); F‐MARC: FIFA Medical Assessment and Research Centre; LAE: Left atrial enlargement; LVH: Left ventricular hypertrophy; PPS: Pre‐participation screening; SCD: Sudden cardiac death
Influence of a magnetic field on an extreme ultraviolet photon-induced plasma afterglow
Authors: Limpens R , Platier B , Lassise A C , Staps T J A , van Ninhuijs M A W , Luiten O J , Beckers J
Published: August 2021

Understanding extreme ultraviolet (EUV) photon-induced plasma dynamics is key to increasing the lifetime of the new generation of lithography machines. The plasma decay times were determined by means of a non-destructive microwave method, microwave cavity resonance spectroscopy, for unmagnetized and magnetized EUV photon-induced plasma afterglows with the argon pressure ranging from 0.002 to 10 Pa. As a result of an external magnet with a magnetic field strength of (57 ± 1) mT, the plasma decay times were extended by two orders of magnitude. Good agreement was found between these measured plasma decay times and four diffusion models, i.e. the ion acoustic, ambipolar, classical-collision, and Bohm’s diffusion model.
Obtaining a copolymer of polyhexamethylene guanidine hydrochloride and polyvinyl alcohol
Authors: Okladnikova V O , Ochirov O S , Grigor’eva M N , Stelmakh S A , Mognonov D M
Published: August 2021

The possibility of obtaining a polymer gel based on polyhexamethylene guanidine hydrochloride and polyvinyl alcohol under conditions of acid catalysis is considered. It was shown that the use of formaldehyde as a crosslinking agent leads to the formation of methylene bridges between the hydroxyl groups of polyvinyl alcohol and the amino groups of polyhexamethylene guanidine hydrochloride. The study of samples obtained by IR spectroscopy revealed the presence of corresponding signals of functional groups at 2780 cm-1 (isolated methylene group between nitrogen and oxygen atoms) and 1580 cm-1 (characteristic band of the guanidine group).
Evaluating the effectiveness of security systems regime of a hypothetical radiological facility using a risk calculation
Authors: Ansah M N S , Stepanov B P , Amoah P A , Agyekum E B
Published: August 2021

This paper presents how security effectiveness can be measured by considering the cost involved in providing security for a radiological center and measures to improve security through risk analysis. The expansion of nuclear technologies and the possible use of nuclear and radioactive materials continues to grow. This increase comes with potential risk of radioactive materials being used for the wrong reasons; thus it is important to provide physical protection of nuclear related facilities to counter these threats and use atomic energy for peaceful purposes. The effectiveness of the security systems put in place at the facility can be assessed by making analysis of the risks associated to the facility.
High-temperature mechanical properties of preceramic paper-derived Ti3Al(Si)C2composites obtained by spark plasma sintering
Authors: Krotkevich D G , Kashkarov E B , Syrtanov M S , Sedanova E P , Mingazova Y R , Travitzky N
Published: August 2021

In the present work, the flexural strength of Ti3Al(Si)C2-based composites was investigated at 25, 800 and 1000 °C using small punch technique. The composites were spark plasma sintered at 1150 °C and 50 MPa from preceramic paper with Ti3Al(Si)C2powder filler. Sintered composites represent a multi-phase system with secondary TiC and Al2O3phases and have more than 900 MPa of flexural strength at room temperature. It was revealed that at 800 °C the flexural strength of composites decreases to 690 MPa. At 1000 °C, the flexural strength of composites further decreased to 620 MPa, however, an anomalous displacement of punch was detected during the fracture test attributed to the Ti3Al(Si)C2brittle-to-plastic transition of the fracture mechanism.
IoT based system for real-time monitoring the hydrogen-ion activity in water bodies
Authors: Yuzhakov M S , Kazanin V A , Berzin A K , Kuleshov G E , Badin A V , Filchenko D I
Published: August 2021

The paper presents design and principle of operation of a mobile combined pH meter. Sensor’s network underlying the IoT system for monitoring water bodies hydrogen ions activity in real time was demonstrated. The measuring device was tested on liquids with different pH levels. The obtained measurement results were compared using a stationary pH meter OHAUS Starter 3100.
Optimization models of agricultural production with heterogeneous land resources
Authors: Ivanyo Ya , Petrova S , Polkovskaya M
Published: August 2021

The paper identifies information that takes into account the heterogeneity of agricultural land on the basis of the use of a precision farming system and geographic information technologies. The tasks of optimizing the production of agricultural products are formulated, describing the heterogeneity of land resources, for averaged and extreme weather and climatic conditions. These models are implemented for an agricultural enterprise in the Irkutsk region. Two variants of the problem are considered: with deterministic and stochastic parameters. As a random variable, the problem uses the crop yield corresponding to the probability of a drought that occurred in the region in 2015. According to the calculations, the use of various technologies of precision farming, taking into account the heterogeneity of arable land, makes it possible to increase the income of the enterprise, reducing the dispersion of the coefficients included in the optimization model agricultural production. At the same time, it is possible to reduce the risks associated with extreme hydrometeorological events, in particular, with drought
The influence of quartz waste addition on the porosity of cement stone
Authors: Kuznetsova I N
Published: August 2021

The article examines the effect of a nanofiller addition, produced from activated quartz waste, on general porosity of cement stone. It contributes to the uniform distribution of micropores and reduction of the cement stone porosity. This improves the physical and mechanical properties of the cement stone. The porosity of the cement stone reduces by 17%, while its density and strength increases.
A New method of LncRNA classification based on ensemble learning
Authors: Dai Zongrui
Published: August 2021

Long noncoding RNAs (lncRNAs), which have a length longer than 200bp (base pair), participate in various critical biological processes. Moreover, they have many similar features with another kind of RNA - coding RNA, such as long length of transcript and poly-A tail. Therefore, distinguish lncRNA and coding RNA can be one important task in bioinformatics. With the advanced and outstanding ability of machine learning, the computational method provides new insight into lncRNA classification. In this study, two feature selection methods (lasso and PCA) are applied to reduce dimension. 8 differentiated features are extracted, and lasso selection indicates better performance than the PCA method. To achieve an advanced performance of lncRNA classification, one novel ensemble learning based on primary learner and secondary learner is constructed. After comparing different kinds of models, ensemble learning achieves the most outstanding performance in AUC and accuracy within the test dataset (The median of Accuracy=0.950228, AUC=0.979664), which may shed light on the classification of lncRNA.
Prediction of learning behavior characters of MOOC’s data based on time series analysis
Authors: Sun Dezhi , Li Tong , You Fucheng , Hu Man , Li Zhenyu
Published: August 2021

In recent years, big data is used in finance, education, biotechnology, and other fields. In the field of education, thanks to the overall characteristics of big data, it can be applied to understand the objective learning rules of students, to provide effective decision-making suggestions for educators. With the development of electronic communication and media technology, Massive Open Online Courses (MOOC), which contains a large number of user behaviors and information, has gradually become one of the mainstream ways of education. However, MOOC have also been criticized for their high dropout rate. Through the analysis of big data contained in MOOC real data set, it can help teachers master students’ learning rules and learning behaviors in time, which is of great significance to improve the level of education and the dropout rate of MOOC. First, it is helpful for teachers to adjust the course content in time according to the learning status. Second, teachers can carry out benign interventions on students’ learning behavior. In this paper, based on the analysis of the real MOOC data of students’ learning behaviors, we find that different groups of students have the same learning behavior at the same learning period, and students’ learning situations can be divided into three stages. Then ARIMA model is used to predict the learning behaviors of students, to further analyze the factors causing the difference in prediction accuracy, we propose an error analysis method based on MSE. Through the experimental observation, the method proposed in this paper can effectively find and predict the characteristics of students’ learning behavior, to give suggestions for improving the quality of teaching.
Domain Concept Extraction and Ontology Visualization
Authors: Li Xiao-fei
Published: August 2021

A semantic navigation method based on ontology was proposed to solve the problem of digital library information trek. In this paper, the domain concept was extracted based on the knowledge base, linguistics, combined word length ratio, domain correlation and domain consistency.Finally, the domain ontology visualization scheme was put forward, and the related updating technology, wide-angle and aggregation technology were analyzed.The process of using Touch Graph to realize the navigation of ontology visual information was also analyzed.
Evaluating System for Effectiveness of Mask Mandates and the Most Influential Factor in Each State in the U.S.A
Authors: Zhou Chuang
Published: August 2021

Over the past year, the COVID-19 outbreak deeply and thoroughly changed the way the world is, and plenty of people died because of this virus. To control the epidemic, all the state governments in the United States took the mask mandates to ask people to wear masks in public. However, many people doubt if the mask can help them prevent the spread of the virus, and there are few researches about the effectiveness of the mask mandates in each state. To tackle this issue, this paper proposed an evaluating system for the effectiveness of mask mandate in each state in the U.S.A, which can be utilized to analyze whether mask mandates can slow down the spread of the virus. And if the effectiveness of mask mandates is different in different states, this paper will continue to find out which factor can most affect the effectiveness. The experimental results demonstrated that even though the new cases in some states still increased after the mask mandates, it can be seemed that the mask mandates do control the spread of the virus in general. According to the research, the paper can find that the most influential factor to the effectiveness is the infection rate. There are also some secondary factors to the effectiveness of mask mandates. Through these researches, they can analyze the result to develop more effective mandates to control the epidemic and help governments and companies develop new products to fit the needs during the epidemic.
Research on Multi-focal Image Fusion Based on Wavelet Transform
Authors: Zhuo Kong , HaiTao Yang , FengJie Zheng , Yang Li , J Qi , JinYu Wang
Published: August 2021

In recent years, wavelet transform theory has been paid more and more attention in image fusion. With the development of wavelet transform image fusion, wavelet transform is introduced, and the basic principles and types of wavelet transform are introduced. Then, aiming at two images with different focal lengths, the discrete wavelet transform method of three-layer decomposition is used, the low-frequency and high-frequency components are fused by different fusion rules, and the differences of different fusion strategies in wavelet transform image fusion are compared and analyzed. Experimental results show that wavelet transform has the characteristics of convenient application, rapid fusion and real image, and has a good application prospect.
Non-cooperative target clustering algorithm based on clonal selection
Authors: Ying Xu , Xiaogang Pan , Jiongqi Wang , Haiyin Zhou , Yangyang Hou
Published: August 2021

Orderly observation of non-cooperative targets for subsequent identification and control is one of the important prerequisites and key technologies of space on orbit service. Restricted by the limited number of ground observation equipment, the visible time window of each non-cooperative target, and the different types of targets, it is increasingly difficult to observe the transit non-cooperative targets and plan the observation tasks. In this paper, the fuzzy clustering algorithm based on clonal selection is used to cluster the non-cooperative targets which are about to cross the border according to their own characteristics, physical characteristics, geometric characteristics, orbital characteristics and other different attributes. Considering the urgency of the task, the importance and priority of each non-cooperative target relative to the observation task are formed, it can provide effective input for the subsequent task planning of non-cooperative target observation, reduce the problem complexity of orderly observation of non-cooperative target, and improve the efficiency of problem solving.
Research on Flower Image Classification Algorithm Based on Convolutional Neural Network
Authors: Jiantao Zhao , Shumin Chu
Published: August 2021

The fast progress of deep learning makes Convolutional Neural Network (CNN) emerges at the historic moment, and as an important achievement, it has been extensively used in all sorts of fields. Compared with traditional machine learning, CNN has more advantages, on the one hand, it has more hidden layers and complex network structure, and on the other hand, it has a stronger ability of feature learning and feature expression. With the fast progress of computer technology, the application research of fast and accurate recognition and classification of flowers by obtaining flower images through mobile devices has received extensive attention. The flowers images collected under natural conditions have large background interference, and it is difficult to recognize flowers because of their inter-class similarity and intra-class diversity. Therefore, in view of the lack of flower image data and low classification accuracy, t he experi m ent sorted out the data sets of four kinds of flowers, and used the CNN to classify the images. Compared with the traditional approaches, the classification precision can be largely enhanced.
An optimized workflow scheduling algorithm on CPU-GPU heterogeneous systems
Authors: Ma Haoyang , Fang Juan
Published: August 2021

Aiming at the workflow scheduling problem on CPU-GPU heterogeneous systems, this article proposes a workflow scheduling algorithm that optimizes task priority and processor selection phase. This article focuses on the relationship between processor processing time and task acceleration ratio, and uses optimistic finish time table. This article estimates each task’s communication cost and computation cost on the basis of each task’s acceleration ratio ri. Then the algorithm calculates the task’s priority ranku based on communication cost and computation cost. In processor selection phase, this article takes the Earliest Finish Time (EFT) difference between the processor with the fastest task and the processor selected based on Heterogeneous Earliest Finish Time (HEFT) algorithm as the judgment condition k. If the difference between the earliest completion time of all child tasks is greater than k, the algorithm selects the processor selected by the HEFT algorithm; otherwise, the algorithm selects another one. This article uses the computational shared facility’s kernel timer for simulation experiment, which bases on the University of Manchester’s high performance computing cluster. Based on the simulation results, the proposed algorithm can reduce the maximum completion time and energy consumption, and improve the acceleration ratio. Compared with the HEFT algorithm, the task maximum completion time and energy consumption are reduced by 10% and 5% respectively, and the acceleration ratio is improved by 3%.
Statistical Evaluation of Green Economic Development Based on Rough Set Calculation Method
Authors: Peng Minjing , Fan Jiajia
Published: August 2021

In the context of big data, decisions and evaluations in business, economics and other fields increasingly rely on data analysis rather than experience and intuition. Data grows exponentially, but not all of it is useful. Rough set is a data mining method to deal with data classification, which can effectively remove redundant information. Green economy is an important proposition of the current world development. The evaluation of green economy should not only focus on economic data, but also environmental and social data. How to filter the data and establish a green economic index evaluation model is the problem this paper wants to solve. Based on the data of green economy and rough set algorithm, this paper evaluates the development level of green economy. Taking the data of Jiangmen city as an example, the evaluation model is tested and analyzed.
Impacts of stormwater infiltration on downslope soil moisture and tree water use
Authors: Western Andrew W , Arora Meenakshi , Burns Matthew J , Bonneau Jérémie , Thom Jasmine K , Yong Chui Fern , James Robert B , Poelsma Peter J , Fletcher Tim D
Published: August 2021

Infiltration of stormwater is a widely used strategy to mitigate the flooding and environmental risks that come from urban runoff and conventional urban drainage. An understanding of the fate of this infiltrated water is required for rigorous design. Principal design objectives are typically to restore more natural hydrology in order to protect receiving waters from pollution and hydrologic change. Without such understanding there is also a risk of unforeseen impacts on nearby infrastructure and urban vegetation. We sought to understand the pathways and fate of water from a stormwater infiltration basin. To trace water, we used a combination of water table monitoring and isotopic composition analysis in the infiltration basin, as well as in rainfall, soil water, the shallow groundwater, and in vegetation upslope and downslope of the basin. We also measured tree water use directly using sap flow sensors. The infiltration basin was shown to increase the availability of water downslope, allowing trees to maintain elevated levels of water use during dry periods with high energy demand. In contrast, water limitation upslope saw substantial seasonal reductions in tree water use. The soil water isotopic composition demonstrated significant differences from upslope to downslope, with downslope water being more reflective of rainfall, while the upslope water used by the trees was more depleted. The results paint a picture of stormwater infiltration being a significant source of lateral flow, while trees are a significant sink of lateral flow emanating from the basin. This finding suggests that stormwater infiltration could be used as a strategy to support the health and growth of urban trees. Urban trees have demonstrated benefits for human health and comfort, particularly in a warming climate. It also suggests that stormwater infiltration may not always recharge groundwater and provide baseflow in receiving waters, being instead taken up by vegetation. These findings should be considered in the siting of stormwater infiltration systems, to ensure that the objectives they were designed for are actually met.
Progress on microstructure features and creep properties of prospective Tin-Silver-Zinc alloy using a magnetic field
Authors: Hammad A E , El-Molla Sara , El-Rehim A F Abd , Ragab M
Published: August 2021

In the current work, applying a rotating magnetic field (RMF) is an innovative approach to improve the microstructure features and creep resistance of Sn-2.0Ag-2.0Zn (SAZ) alloy. The results revealed that RMF does not change intermetallic compounds (IMCs) constituents furthermore SAZ alloy with applying a magnetic field (SAZ-B) exhibited microstructure refinement and homogeneous distribution of IMCs. Moreover, SAZ-B displayed more creep resistance (∼366%) and greater creep rupture time (∼56.4%) than those of SAZ alloy. These results have great implications in improving the alloy’s performance for industrial applications.
Telling the Untold Story: Jewish Wartime Refuge in Haiti in Louis-Philippe Dalembert’s Avant que les ombres s’effacent
Authors: Casteel Sarah Phillips
Published: August 2021

Literary narratives of Jewish refugees in the Caribbean uncover a forgotten chapter of wartime history. A key example is Haitian author Louis-Philippe Dalembert’s novel Avant que les ombres s’effacent (2017), which tracks the traumatic dispersion of a Polish Jewish family to Haiti, Cuba, Israel, and the US in the late 1930s. Dalembert interweaves the tale of his Jewish protagonist’s flight to Haiti with portrayals of the Haitian émigré community in Paris and the Haitian concentration camp prisoner Jean-Marcel Nicolas. Blending fact and fiction, the novel highlights the Haitian state’s little-known efforts to aid Holocaust refugees and connects those efforts to the island nation’s own revolutionary history. In this article, I argue that fiction’s unique traits as a medium of cultural memory enable Dalembert to reframe the wartime past from a Haitian perspective. Avant que les ombres s’effacent harnesses the fictional privileges of literary narrative, mediating between the real and the imaginary and combining Jewish and Caribbean memory systems in unexpected and often startling ways. Generating images of the wartime past that transform our perception of it, the novel moves Haiti to the center of the story and in so doing uncovers global dimensions of Jewish experience.
Defining Ideal External Female Genital Anatomy via Crowdsourcing Analysis
Authors: Frojo Gianfranco , Kareh Aurora M , Stash Bryce D , Probst Kenneth X , Rector Jeffrey D , Plikaitis Christina M , Lund Herluf G , Lin Alexander Y
Published: August 2021

Background

Despite existing anthropometric data in the literature regarding the variation of female external genital anatomy, the ideal aesthetic characteristics have yet to be defined.

Objectives

The authors utilized crowdsourcing to better evaluate preferred anatomic characteristics of external female genitalia.

Methods

Fifty-six total images were digitally created by altering the proportions of the labia minora, labia majora, and clitoral hood. Images with differing ratios were presented in pairs to Amazon Mechanical Turk (Seattle, WA, USA) raters. Three different experiments were performed with each varying 2 of the 3 image characteristics to permit 2-factor modeling. The Bradley-Terry-Luce model was applied to the pairwise comparisons ratings to create a rank order for each image. Preferences for each anatomic variable were compared with chi-squared tests.

Results

A total of 5000 raters participated. Experiment 1 compared differing widths of the labia majora and labia minora and determined a significant preference for larger labia majora width and mid-range labia minora width (P = 0.007). Experiment 2 compared labia minora width vs clitoral hood length and showed a statistically significant preference for wider majoras (P < 0.001) but no significant preference in clitoral hood length (P = 0.54). Experiment 3 compared clitoral hood length vs labia minora width and showed a statistically significant preference for mid-range labia minora widths (P < 0.001) but no significant preference in clitoral hood length (P = 0.78).

Conclusions

Raters preferred a labia majora to labia minora width ratio of 3:1 with minimal preference in clitoral hood length.
Factors Influencing Social Work Identity in Mental Health Placements
Authors: Smith Fiona Louise , Harms Louise , Brophy Lisa
Published: August 2021

This article shares findings from a study that explored factors contributing to the development of a social work professional identity, with a particular focus on social work students undertaking field education placements in mental health settings. Social work identity is not well recognised or articulated by experienced practitioners, nor does it appear to be adequately emphasised in social work education and training programmes. There is limited research on social work identity in mental health settings and even less pertaining to students’ efforts to construct a professional identity in such paradigmatically unfamiliar environments. This qualitative study explored how students understand, experience and articulate their developing professional identity in mental health settings. Participants were interviewed towards the completion of seventy-day (500-hour) field placements. Findings highlight that students struggled to relate to the concept of a ‘social work identity’ and were unable to articulate what it might be or involve. Students were more at ease describing specific roles they performed during their placement. However, analysis of their reflections on what they observed, what they did during placement, and reflective or integrative opportunities, provided rich descriptions of a range of the factors contributing to and influencing their developing social work identity.
Dying-back of ascending noradrenergic projections in Parkinson’s disease
Authors: Helmich Rick C , Lehéricy Stéphane
Published: August 2021

This scientific commentary refers to ‘Regional locus coeruleus degeneration is uncoupled from noradrenergic terminal loss in Parkinson’s disease’, by Doppler et al. (doi:10.1093/brain/awab236).
Articulatory Gain Predicts Motor Cortex and Subthalamic Nucleus Activity During Speech
Authors: Dastolfo-Hromack C , Bush A , Chrabaszcz A , Alhourani A , Lipski W , Wang D , Crammond D J , Shaiman S , Dickey M W , Holt L L , Turner R S , Fiez J A , Richardson R M
Published: August 2021

Speaking precisely is important for effective verbal communication, and articulatory gain is one component of speech motor control that contributes to achieving this goal. Given that the basal ganglia have been proposed to regulate the speed and size of limb movement, that is, movement gain, we explored the basal ganglia contribution to articulatory gain, through local field potentials (LFP) recorded simultaneously from the subthalamic nucleus (STN), precentral gyrus, and postcentral gyrus. During STN deep brain stimulation implantation for Parkinson’s disease, participants read aloud consonant-vowel-consonant syllables. Articulatory gain was indirectly assessed using the F2 Ratio, an acoustic measurement of the second formant frequency of/i/vowels divided by/u/vowels. Mixed effects models demonstrated that the F2 Ratio correlated with alpha and theta activity in the precentral gyrus and STN. No correlations were observed for the postcentral gyrus. Functional connectivity analysis revealed that higher phase locking values for beta activity between the STN and precentral gyrus were correlated with lower F2 Ratios, suggesting that higher beta synchrony impairs articulatory precision. Effects were not related to disease severity. These data suggest that articulatory gain is encoded within the basal ganglia-cortical loop.
ProBDNF Dependence of LTD and Fear Extinction Learning in the Amygdala of Adult Mice
Authors: Ma Xiaoyun , Vuyyuru Harish , Munsch Thomas , Endres Thomas , Lessmann Volkmar , Meis Susanne
Published: August 2021

Neurotrophins are secreted proteins that control survival, differentiation, and synaptic plasticity. While mature neurotrophins regulate these functions via tyrosine kinase signaling (Trk), uncleaved pro-neurotrophins bind preferentially to the p75 neurotrophin receptor (p75NTR) and often exert opposite effects to those of mature neurotrophins. In the amygdala, brain-derived neurotrophic factor (BDNF) enables long-term potentiation as well as fear and fear extinction learning. In the present study, we focused on the impact of mature BDNF and proBDNF signaling on long-term depression (LTD) in the lateral amygdala (LA). Hence, we conducted extracellular field potential recordings in an in vitro slice preparation and recorded LTD in cortical and thalamic afferents to the LA. LTD was unchanged by acute block of BDNF/TrkB signaling. In contrast, LTD was inhibited by blocking p75NTR signaling, by disinhibition of the proteolytic cleavage of proBDNF into mature BDNF, and by preincubation with a function-blocking anti-proBDNF antibody. Since LTD-like processes in the amygdala are supposed to be related to fear extinction learning, we locally inhibited p75NTR signaling in the amygdala during or after fear extinction training, resulting in impaired fear extinction memory. Overall, these results suggest that in the amygdala proBDNF/p75NTR signaling plays a pivotal role in LTD and fear extinction learning.
Chaebols and firm dynamics in Korea
Authors: Aghion Philippe , Guriev Sergei , Jo Kangchul
Published: August 2021

We study firm dynamics in Korea before and after the 1997/8 Asian crisis and pro-competitive reforms that reduced the dominance of chaebols. We find that in industries that were dominated by chaebols before the crisis, labour productivity and total factor productivity of non-chaebol firms increased markedly after the reforms (relative to other industries). Furthermore, entry of non-chaebol firms increased significantly in all industries after the reform. After the crisis, the non-chaebol firms also dramatically increased their patenting activity. Finally, markups of chaebol firms declined substantially, especially within industries dominated by chaebols before the crisis. These results suggest that the crisis had the virtue of helping Korea move from catching-up growth based on investment in existing technologies to innovation-based growth.