bluuebunny/crossref_metadata_2025 huggingface dataset:
Deep Reinforcement Learning in Agent Based Financial Market Simulation
Authors: Maeda Iwao , deGraw David , Kitano Michiharu , Matsushima Hiroyasu , Sakaji Hiroki , Izumi Kiyoshi , Kato Atsuo
Published: April 2020

Prediction of financial market data with deep learning models has achieved some level of recent success. However, historical financial data suffer from an unknowable state space, limited observations, and the inability to model the impact of your own actions on the market can often be prohibitive when trying to find investment strategies using deep reinforcement learning. One way to overcome these limitations is to augment real market data with agent based artificial market simulation. Artificial market simulations designed to reproduce realistic market features may be used to create unobserved market states, to model the impact of your own investment actions on the market itself, and train models with as much data as necessary. In this study we propose a framework for training deep reinforcement learning models in agent based artificial price-order-book simulations that yield non-trivial policies under diverse conditions with market impact. Our simulations confirm that the proposed deep reinforcement learning model with unique task-specific reward function was able to learn a robust investment strategy with an attractive risk-return profile.
Spatial-Temporal Characteristics of Cultivated Land Use Efficiency in Major Function-Oriented Zones: A Case Study of Zhejiang Province, China
Authors: Zhang Chaozheng , Su Yangyue , Yang Gangqiao , Chen Danling , Yang Rongxuan
Published: April 2020

Promoting cultivated land use efficiency (CLUE) coordinated development in various major function-oriented zones is a measure to deal with unbalanced development of territorial space in China. Taking the optimized development, key development, agricultural production, ecological function, and ecological economic zones of Zhejiang province as research objects, this study incorporated agricultural carbon emission into the measurement framework of CLUE and analyzed the regional disparity and the convergence of CLUE from 2008 to 2017, using slack-based measure model (SBM), the Theil index, and convergence theory. The main results are as follows: (1) The CLUE value that considered agricultural carbon emissions was lower than the CLUE value that did not consider agricultural carbon emissions; thus, agricultural carbon emissions had a negative effect on CLUE. (2) The CLUE value of the five major function-oriented zones showed an increasing trend; after ranking the CLUE value, the CLUE of the optimized development zones was the highest, followed by the ecological function, ecological economic, and key development zones, and that of the agricultural production zones was the lowest, indicating significant regional disparity. (3) The overall disparity of CLUE presented an upward trend, and the within-regional disparity is the main source of the overall disparity. (4) Neither σ convergence nor absolute β convergence occurred in the CLUE of the five major function-oriented zones, but conditional β convergence occurred among the optimized development and ecological economic zones. Although the planning of major function-oriented zones reflects the regional disparity and convergence of CLUE to some extent, the CLUE under the control of major function-oriented zones is not consistent with the function positioning.
Environmental Transformations in the Area of the Kuźnica Warężyńska Sand Mine, Southern Poland
Authors: Różkowski Jacek , Rahmonov Oimahmad , Szymczyk Artur
Published: April 2020

On the basis of the analysis and interpretation of maps, published literature, and environmental reconnaissance, this article discusses environmental transformations in the area of the Kuźnica Warężyńska sand mine in southern Poland over the years 1944–2015. A comprehensive ecological analysis was carried out concerning spatial development, mining activity, hydrogeological and hydrological conditions as well as the biotic environment. Among the unfavourable changes found were a drastic reduction in the agricultural function of the area (from 7.03 to 0.47 km2), mainly due to periodic activity of sand mine in 1967–2002, covering an area of about 5.80 km2, the destruction of the original biocenoses, the depletion and deterioration in quality of the groundwater resources, and man-made transformations of the hydrographic network (during the mine’s activity its length reached over 103 km). Vegetation changes during the 70-year period examined were closely related to human mining activity. The greatest changes occurred at the end of the 1960s when large areas of pine forest were cut down. The analysis of vegetation in the former workings demonstrated that the diversity of habitats within the workings results in a significant increase in species (367 plant species, 2002 birds) and community diversity (Molinion caeruleae, Molinion caeruleae, three Natura habitats) there compared to the adjacent areas. On the other hand, favourable changes included the construction of a flood control reservoir, with an area of 560 ha and a volume of 51 million m3, created in 2003–2005, making the area more attractive for tourism and recreation, and an increase in biodiversity, including the establishment of a Natura 2000 site.
Relating Lexical Access and Second Language Speaking Performance
Authors: Liu Yu
Published: April 2020

Vocabulary plays a key role in speech production, affecting multiple stages of language processing. This pilot study investigates the relationships between second language (L2) learners’ lexical access and their speaking fluency, speaking accuracy, and speaking complexity. Fifteen L2 learners of Chinese participated in the experiment. A task-specific, native-referenced vocabulary test was used to measure learners’ vocabulary size and lexical retrieval speed. Learners’ speaking performance was measured by thirteen variables. The results showed that lexical access was significantly correlated with learners’ speech rate, lexical accuracy, syntactic accuracy, and lexical complexity. Vocabulary size and lexical retrieval speed were significant predictors of speech rate. However, vocabulary size and lexical retrieval speed each affected learners’ speaking performance differently. Learners’ speaking fluency, accuracy, and complexity were all affected by vocabulary size. No significant correlation was found between lexical retrieval speed and syntactic complexity. Findings in this study support the Model of Bilingual Speech Production, revealing the significant role lexical access plays in L2 speech production.
Exploring the Impact of Government Regulation on Technological Transitions; a Historical Perspective on Innovation in the Dutch Network-Based Industries
Authors: Stout Helen , Jong Martin de
Published: April 2020

Government interventions can affect processes of technological transition through the enactment of legal and other policy instruments. In this contribution, we concentrated on legal interventions only and examined what they were, the relation between the public and private players that they affected, and the nature of the incentive they provided. We did this for four historical cases in the world of utility industries in the Netherlands in the nineteenth and twentieth centuries. The summarizing results for each case appeared in overview tables which eventually showed whether most of the administered stimuli were negative, neutral, or positive for the action alternatives of the innovating players, and thus the further development of the newly emerging technology. It is hard to escape the conclusion that the common argument and rhetoric that governments normally aim to propel industrial progress by opening a variety of options for innovating private players rings hollow when analyzed more systematically. A higher number of the incentives we found across the four cases were negative rather than positive, while some cases had only negative incentives and none had more positive than negative incentives.
Comparative Study on Flow-Accelerated Corrosion and Erosion–Corrosion at a 90° Carbon Steel Bend
Authors: Zeng Li , Chen Geng , Chen Hanxin
Published: April 2020

Electrochemical measurements and surface analysis are performed to comparatively study flow-accelerated corrosion (FAC) and erosion–corrosion (E-C) behavior at a 90° carbon steel bend. The corrosion rates are higher under FAC conditions than those under E-C conditions. For FAC, the corrosion is more serious at the inside wall. However, corrosion is exacerbated at the outside wall under E-C conditions. No erosion scratches are observed under FAC conditions and at the inside wall under E-C conditions, while remarkable erosion scratches appear at the outside wall under E-C conditions. The dominant hydrodynamics affecting FAC and E-C are remarkably different.
Effects of Chemically Treated Eucalyptus Fibers on Mechanical, Thermal and Insulating Properties of Polyurethane Composite Foams
Authors: Członka Sylwia , Strąkowska Anna , Pospiech Piotr , Strzelec Krzysztof
Published: April 2020

In this work, rigid polyurethane (PUR) foams were prepared by incorporating 2 wt% of eucalyptus fibers. The eucalyptus fibers were surface-modified by maleic anhydride, alkali, and silane (triphenylsilanol) treatment. The impact of the modified eucalyptus fibers on the mechanical, thermal, and fire performances of polyurethane foams was analyzed. It was observed that the addition of eucalyptus fibers showed improved mechanical and thermal properties and the best properties were shown by silane-treated fibers with a compressive strength of 312 kPa and a flexural strength of 432 kPa. Moreover, the thermal stability values showed the lowest decline for polyurethane foams modified with the silane-treated fibers, due to the better thermal stability of such modified fibers. Furthermore, the flame resistance of polyurethane foams modified with the silane-treated fibers was also the best among the studied composites. A cone calorimetry test showed a decrease in the peak of heat release from 245 to 110 kW∙m−2 by the incorporation of silane-treated fibers. Furthermore, total heat release and total smoke release were also found to decrease remarkably upon the incorporation of silane-treated fibers. The value of limiting oxygen index was increased from 20.2% to 22.1%. Char residue was also found to be increased from 24.4% to 28.3%. It can be concluded that the application of chemically modified eucalyptus fibers has great potential as an additive to incorporate good mechanical, thermal, and fire properties in rigid polyurethane foams.
Carvacrol Prodrugs with Antimicrobial Activity Loaded on Clay Nanocomposites
Authors: Eusepi Piera , Marinelli Lisa , García-Villén Fátima , Borrego-Sánchez Ana , Cacciatore Ivana , Di Stefano Antonio , Viseras Cesar
Published: April 2020

Background: Carvacrol, an essential oil with antimicrobial activity against a wide range of pathogens, and its water soluble carvacrol prodrugs (WSCP1-3) were intercalated into montmorillonite (VHS) interlayers to improve their stability in physiological media and promote their absorption in the intestine. Methods: Intercalation of prodrugs by cation exchange with montmorillonite interlayer counterions was verified by X-ray powder diffraction and confirmed by Fourier transform infrared spectroscopy and thermal analysis. Results: In vitro release studies demonstrated that montmorillonite successfully controlled the release of the adsorbed prodrugs and promoted their bioactivation only in the intestinal tract where carvacrol could develop its maximum antimicrobial activity. The amount of WSCP1, WSCP2, and WSCP3 released from VHS were 38%, 54%, and 45% at acid pH in 120 min, and 65%, 78%, and 44% at pH 6.8 in 240 min, respectively. Conclusions: The resultant hybrids successfully controlled conversion of the prodrugs to carvacrol, avoiding premature degradation of the drug.
Constitutive Models for Dynamic Strain Aging in Metals: Strain Rate and Temperature Dependences on the Flow Stress
Authors: Song Yooseob , Garcia-Gonzalez Daniel , Rusinek Alexis
Published: April 2020

A new constitutive model for Q235B structural steel is proposed, incorporating the effect of dynamic strain aging. Dynamic strain aging hugely affects the microstructural behavior of metallic compounds, in turn leading to significant alterations in their macroscopic mechanical response. Therefore, a constitutive model must incorporate the effect of dynamic strain aging to accurately predict thermo-mechanical deformation processes. The proposed model assumes the overall response of the material as a combination of three contributions: athermal, thermally activated, and dynamic strain aging stress components. The dynamic strain aging is approached by two alternative mathematical expressions: (i) model I: rate-independent model; (ii) model II: rate-dependent model. The proposed model is finally used to study the mechanical response of Q235B steel for a wide range of loading conditions, from quasi-static loading ( ε ˙ = 0.001   s − 1 and ε ˙ = 0.02   s − 1 ) to dynamic loading ( ε ˙ = 800   s − 1 and ε ˙ = 7000   s − 1 ), and across a broad range of temperatures ( 93   K − 1173   K ). The results from this work highlight the importance of considering strain-rate dependences (model II) to provide reliable predictions under dynamic loading scenarios. In this regard, rate-independent approaches (model I) are rather limited to quasi-static loading.
Effect of the Operational Conditions in the Characteristics of Ceramic Foams Obtained from Quartz and Sodium Silicate
Authors: Uribe Lina , Giraldo Juan D. , Vargas Alejandro
Published: April 2020

Ceramic foams were fabricated without using melting pots through the direct foaming of compacted powder mixtures of commercial quartz (SiO2) with fluxing agents (Na2CO3 and CaO) and a foaming agent (Na2SiO3·5H2O) at a relatively low temperature range (850−870 °C). The effects of the pressing pressure of the powders, the foaming time, foaming temperature, and mixture content were evaluated. The obtained cellular solid materials presented an acceptable volumetric expansion at a pressing pressure of 4 t. The materials only presented porosity at a minimum temperature of 850 °C and at a minimum time of 30 min. All the foamed samples showed an acceptable symmetric expansion and non-appreciable fissures. The study of the mixture content through the statistical software MODDE® shows that the porosity of the samples was principally affected by the Na2SiO3 content and the foaming temperature. The samples obtained at the optimum controlling factors proposed by this statistical software presented an apparent density, porosity, and mechanical strength of 1.09 ± 0.03 g/cm3, 56.01% ± 1.12%, and 3.90 ± 0.16 MPa, respectively. Glass and ceramics foams such as those obtained in this work become attractive as insulation materials in applications where high temperatures occur due to their higher melting points.
Study on Establishing Degradation Model of Chip Solder Joint Material under Coupled Stress
Authors: Li Longteng , Jing Bo , Hu Jiaxing
Published: April 2020

The chip is the core component of the integrated circuit. Degradation and failure of chip solder joints can directly lead to function loss of the integrated circuit. In order to establish the degradation model of chip solder joints under coupled stress, this paper takes quad flat package (QFP) chip solder joints as the study object. First, solder joint degradation data and failure samples were obtained through fatigue tests under coupled stress. Three types of micro failure modes of solder joints were obtained by scanning electron microscope (SEM) analysis and finite element model (FEM) simulation results. Second, the characterization of degradation data was obtained by the principal component of Mahalanobis distance (PCMD) algorithm. It is found that solder joint degradation is divided into three stages: strain accumulation stage, crack propagation stage, and failure stage. Later, Coffin–Manson model and Paris model were modified based on the PCMD health index and strain simulation. The function relationship between strain accumulation time, crack propagation time, and strain was determined, respectively. Solder joint degradation models at different degradation stage were established. Finally, through strain simulation, the models can predict the strain accumulation time and failure time effectively under each failure mode, and their prediction accuracy is above 85%.
The Effect of Temperature and Milling Process on Steel Scale Utilized as a Pigment for Ceramic Glaze
Authors: Ovčačíková Hana , Vlček Jozef , Matějka Vlastimil , Juřica Jan , Maierová Petra , Mlčoch Petr
Published: April 2020

This study is focused on the evaluation of the re-utilizability of scale originated during the steel casting and steel rolling processes as a pigment for glazes. Non-oiled scale with Fe3O4 as the major phase were used as a coloring component of transparent glaze matrix in: (i) as received state, (ii) thermally pre-treated at 700 and 900 °C, (iii) mechanically treated in planetary ball mill (60, 120 and 240 min) and (iv) mechanically treated in vibratory disc mill (60 and 120 min). Prepared glazes were applied on the surface of ceramic tiles prepared from a commercially available white ceramic slurry. The resulting tiles with given glaze were thermally treated at 800, 900 and 1060 °C. The pigments were characterized by X-ray powder diffraction method (XRD), X-ray fluorescence spectroscopy (XRF), granulometry (PSD), thermogravimetric analysis (TG) and differential thermal analysis (DTA), scanning electron microscopy (SEM/EDAX). The color of the samples was described by the coordinates L*a*b* from CIELAB color space. The results showed that the non-oiled scale is suitable as the pigment for ceramic glazes. Careful control of the scale treatment process (mechanical as well as thermal) together with the temperature of final glaze firing is necessary to obtain the glaze of desired color and quality.
Dynamical Mechanical and Thermal Analyses of Biodegradable Raw Materials for Additive Manufacturing
Authors: Mazurchevici Simona-Nicoleta , Mazurchevici Andrei-Danut , Nedelcu Dumitru
Published: April 2020

In order to find new ways to ensure sustainable development on a global level, it is essential to combine current top technologies, such as additive manufacturing, with the economic, ecological, and social fields. One objective of this paper refers to wire manufacture such as Arboblend V2 Nature, Arbofill Fichte, and Arboblend V2 Nature reinforced with Extrudr BDP “Pearl” (BDP—Biodegradable Plastic) in order to replace the plastic materials. After wire manufacture by extrusion, the diameter accuracy was analyzed compared with the Fiber Wood wire using SEM analyses and also EDAX—Energy Dispersive X-ray Analysis and DSC—Differential Scanning Calorimetry analyses were done in order to identify their elemental composition and the phase transitions suffered by the materials during heating. Using the samples obtained through the Fused Deposition Modeling (FDM) method, both crystalline phases and chemical composition information (XRD analysis) were identified, as well was determined the visco-elastic behavior Dynamic Mechanical Analysis (DMA), for the reinforced material and Fiber Wood. The extruded wires have allowed size for the printing equipment, around 1.75 mm with tolerance of ± 0.05 mm. The wire material diagrams, Arboblend V2 Nature reinforced with Extrudr BDP “Pearl” and Fiber Wood following the calorimetric analysis, presented peaks corresponding to material crystallization, while Arbofill Fichte revealed only the melting temperature. The storage module was almost double in case of Arboblend V2 Nature reinforced with Extrudr BDP “Pearl” compared with Fiber Wood and materials’ melting temperatures were confirmed by the analyses carried out.
Application of Electrically Conducting Nanocomposite Material Polythiophene@NiO/Frt/GOx as Anode for Enzymatic Biofuel Cells
Authors: Inamuddin  , Alamry Khalid A.
Published: April 2020

In this work, nano-inspired nickel oxide nanoparticles (NiO) and polythiophene (Pth) modified bioanode was prepared for biofuel cell applications. The chemically prepared nickel oxide nanoparticles and its composite with polythiophene were characterized for elemental composition and microscopic characterization while using scanning electron microscopy. The electrochemical characterizations of polythiophene@NiO composite, biocompatible mediator ferritin (Frt) and glucose oxidase (GOx) catalyst modified glassy carbon (GC) electrode were carried out using cyclic voltammetry (CV), linear sweep voltammetry (LSV), and charge-discharge studies. The current density of Pth@NiO/Frt/GOx bioanode was found to be 5.4 mA/cm2. The bioanode exhibited a good bio-electrocatalytic activity towards the oxidation of the glucose. The experimental studies of the bioanode are justifying its employment in biofuel cells. This will cater a platform for the generation of sustainable energy for low temperature devices.
Formula-Driven, Size-Tunable Synthesis of PMMA Nanoparticles by Varying Surfactant Concentration
Authors: Kamras Brian L. , Mirzanasiri Nooshin , Korir Daniel K. , Mandal Sujata , Hariharakumar Shreya L. , Petros Robby A. , Marpu Sreekar B. , Simmons Denise P. , Omary Mohammad A.
Published: April 2020

In this communication, we present a streamlined, reproducible synthetic method for the production of size-tunable poly(methyl methacrylate) (PMMA) nanoparticles (PMMANPs) and amine-functionalized block-copolymer PMMANPs (H2N-PMMANPs) by varying subcritical concentrations (i.e., below the concentration required to form micelles at 1 atm and 20 °C) of sodium dodecyl sulfate (SDS). We plotted the Z-average size data against SDS concentration, which revealed a second-order exponential decay function, expressed as A 1 e − x t 1 + A 2 e − x t 2 + y 0 . The surfactant concentration (wt./wt.%) has been selected as independent variable x. This function is valid at least for the size range of 20 nm to 97 nm (PMMANPs) and 20 nm to 133 nm (H2N-PMMANPs).
A Hybrid k-Means Cuckoo Search Algorithm Applied to the Counterfort Retaining Walls Problem
Authors: García José , Yepes Victor , Martí José V.
Published: April 2020

The counterfort retaining wall is one of the most frequent structures used in civil engineering. In this structure, optimization of cost and CO2 emissions are important. The first is relevant in the competitiveness and efficiency of the company, the second in environmental impact. From the point of view of computational complexity, the problem is challenging due to the large number of possible combinations in the solution space. In this article, a k-means cuckoo search hybrid algorithm is proposed where the cuckoo search metaheuristic is used as an optimization mechanism in continuous spaces and the unsupervised k-means learning technique to discretize the solutions. A random operator is designed to determine the contribution of the k-means operator in the optimization process. The best values, the averages, and the interquartile ranges of the obtained distributions are compared. The hybrid algorithm was later compared to a version of harmony search that also solved the problem. The results show that the k-mean operator contributes significantly to the quality of the solutions and that our algorithm is highly competitive, surpassing the results obtained by harmony search.
Probability-Based Wildfire Risk Measure for Decision-Making
Authors: Rodríguez-Martínez Adán , Vitoriano Begoña
Published: April 2020

Wildfire is a natural element of many ecosystems as well as a natural disaster to be prevented. Climate and land usage changes have increased the number and size of wildfires in the last few decades. In this situation, governments must be able to manage wildfire, and a risk measure can be crucial to evaluate any preventive action and to support decision-making. In this paper, a risk measure based on ignition and spread probabilities is developed modeling a forest landscape as an interconnected system of homogeneous sectors. The measure is defined as the expected value of losses due to fire, based on the probabilities of each sector burning. An efficient method based on Bayesian networks to compute the probability of fire in each sector is provided. The risk measure is suitable to support decision-making to compare preventive actions and to choose the best alternatives reducing the risk of a network. The paper is divided into three parts. First, we present the theoretical framework on which the risk measure is based, outlining some necessary properties of the fire probabilistic model as well as discussing the definition of the event ‘fire’. In the second part, we show how to avoid topological restrictions in the network and produce a computable and comprehensible wildfire risk measure. Finally, an illustrative case example is included.
An Efficient Numerical Method for Fractional SIR Epidemic Model of Infectious Disease by Using Bernstein Wavelets
Authors: Kumar Sunil , Ahmadian Ali , Kumar Ranbir , Kumar Devendra , Singh Jagdev , Baleanu Dumitru , Salimi Mehdi
Published: April 2020

In this paper, the operational matrix based on Bernstein wavelets is presented for solving fractional SIR model with unknown parameters. The SIR model is a system of differential equations that arises in medical science to study epidemiology and medical care for the injured. Operational matrices merged with the collocation method are used to convert fractional-order problems into algebraic equations. The Adams–Bashforth–Moulton predictor correcter scheme is also discussed for solving the same. We have compared the solutions with the Adams–Bashforth predictor correcter scheme for the accuracy and applicability of the Bernstein wavelet method. The convergence analysis of the Bernstein wavelet has been also discussed for the validity of the method.
A Note on NIEP for Leslie and Doubly Leslie Matrices
Authors: Medina Luis , Nina Hans , Valero Elvis
Published: April 2020

The nonnegative inverse eigenvalue problem (NIEP) consists of finding necessary and sufficient conditions for the existence of a nonnegative matrix with a given list of complex numbers as its spectrum. If the matrix is required to be Leslie (doubly Leslie), the problem is called the Leslie (doubly Leslie) nonnegative eigenvalue inverse problem. In this paper, necessary and/or sufficient conditions for the existence and construction of Leslie and doubly Leslie matrices with a given spectrum are considered.
Extension of Calculus Operations in Cartesian Tensor Analysis
Authors: Lu Yiyu , Yue Peng , Wei Sibei
Published: April 2020

In this paper, we derive and propose basic differential operations and generalized Green’s integral theorems applicable to multidimensional spaces based on Cartesian tensor analysis to solve some nonlinear problems in smooth spaces in the necessary dimensions. In practical applications, the theorem can be applied to numerical analysis in the conservation law, effectively reducing the dimensions of high-dimensional problems and reducing the computational difficulty, which can be effectively used in the solution of complex dimensional mechanical problems.
Mathematical Models with Buckling and Contact Phenomena for Elastic Plates: A Review
Authors: Muradova Aliki D. , Stavroulakis Georgios E.
Published: April 2020

A review of mathematical models for elastic plates with buckling and contact phenomena is provided. The state of the art in this domain is presented. Buckling effects are discussed on an example of a system of nonlinear partial differential equations, describing large deflections of the plate. Unilateral contact problems with buckling, including models for plates, resting on elastic foundations, and contact models for delaminated composite plates, are formulated. Dynamic nonlinear equations for elastic plates, which possess buckling and contact effects are also presented. Most commonly used boundary and initial conditions are set up. The advantages and disadvantages of analytical, semi-analytical, and numerical techniques for the buckling and contact problems are discussed. The corresponding references are given.
Homomorphic Image and Inverse Image of Weak Closure Operations on Ideals of BCK-Algebras
Authors: Bordbar Hashem , Jun Young Bae , Song Seok-Zun
Published: April 2020

We introduce the notions of meet, semi-prime, and prime weak closure operations. Using homomorphism of BCK-algebras φ : X → Y , we show that every epimorphic image of a non-zeromeet element is also non-zeromeet and, for mapping c l Y : I ( Y ) → I ( Y ) , we define a map c l Y ← on I ( X ) by A ↦ φ − 1 ( φ ( A ) c l Y ) . We prove that, if “ c l Y ” is a weak closure operation (respectively, semi-prime and meet) on I ( Y ) , then so is “ c l Y ← ” on I ( X ) . In addition, for mapping c l X : I ( X ) → I ( X ) , we define a map c l X → on I ( Y ) as follows: B ↦ φ ( φ − 1 ( B ) c l X ) . We show that, if “ c l X ” is a weak closure operation (respectively, semi-prime and meet) on I ( X ) , then so is “ c l X → ” on I ( Y ) .
An Evolve-Then-Correct Reduced Order Model for Hidden Fluid Dynamics
Authors: Pawar Suraj , Ahmed Shady E. , San Omer , Rasheed Adil
Published: April 2020

In this paper, we put forth an evolve-then-correct reduced order modeling approach that combines intrusive and nonintrusive models to take hidden physical processes into account. Specifically, we split the underlying dynamics into known and unknown components. In the known part, we first utilize an intrusive Galerkin method projected on a set of basis functions obtained by proper orthogonal decomposition. We then present two variants of correction formula based on the assumption that the observed data are a manifestation of all relevant processes. The first method uses a standard least-squares regression with a quadratic approximation and requires solving a rank-deficient linear system, while the second approach employs a recurrent neural network emulator to account for the correction term. We further enhance our approach by using an orthonormality conforming basis interpolation approach on a Grassmannian manifold to address off-design conditions. The proposed framework is illustrated here with the application of two-dimensional co-rotating vortex simulations under modeling uncertainty. The results demonstrate highly accurate predictions underlining the effectiveness of the evolve-then-correct approach toward real-time simulations, where the full process model is not known a priori.
Absence of Non-Trivial Fuzzy Inner Product Spaces and the Cauchy–Schwartz Inequality
Authors: Byun Taechang , Lee Ji Eun , Lee Keun Young , Yoon Jin Hee
Published: April 2020

First, we show that the non-trivial fuzzy inner product space under the linearity condition does not exist, which means a fuzzy inner product space with linearity produces only a crisp real number for each pair of vectors. If the positive-definiteness is added to the condition, then the Cauchy–Schwartz inequality is also proved.
Asymptotic Convergence of Soft-Constrained Neural Networks for Density Estimation
Authors: Trentin Edmondo
Published: April 2020

A soft-constrained neural network for density estimation (SC-NN-4pdf) has recently been introduced to tackle the issues arising from the application of neural networks to density estimation problems (in particular, the satisfaction of the second Kolmogorov axiom). Although the SC-NN-4pdf has been shown to outperform parametric and non-parametric approaches (from both the machine learning and the statistics areas) over a variety of univariate and multivariate density estimation tasks, no clear rationale behind its performance has been put forward so far. Neither has there been any analysis of the fundamental theoretical properties of the SC-NN-4pdf. This paper narrows the gaps, delivering a formal statement of the class of density functions that can be modeled to any degree of precision by SC-NN-4pdfs, as well as a proof of asymptotic convergence in probability of the SC-NN-4pdf training algorithm under mild conditions for a popular class of neural architectures. These properties of the SC-NN-4pdf lay the groundwork for understanding the strong estimation capabilities that SC-NN-4pdfs have only exhibited empirically so far.
Constructing Fuzzy Hypothesis Methods to Determine Critical-To-Quality Service Items
Authors: Yu Chun-Hung , Liu Chin-Chia , Chen Kuen-Suan , Yu Chun-Min
Published: April 2020

This paper constructs a performance evaluation matrix (PEM) with beta distribution. Beta is between zero and one, making it a suitable indicator to describe customer ratings of importance and satisfaction from 0% to 100%. According to the spirit of ceaseless improvement put forward by total quality management, the average ratings are set as the standard, and then the coordinates of each satisfaction and importance item is located in the performance areas. This makes it easy to identify critical-to-quality items that require improvement. However, the data collection method of questionnaires inevitably involves sampling error, and the opinions of customers are often ambiguous. To solve these problems, we constructed a fuzzy testing method based on confidence intervals. The use of confidence intervals decreases the chance of misjudgment caused by sampling errors, and more precisely gets closer to customers’ voices. This result is more reasonable than the traditional statistical testing principle. The proposed methods are applied to assessment of a computer-assisted language learning (CALL) system to display their competence.
A Generalized Equilibrium Transform with Application to Error Bounds in the Rényi Theorem with No Support Constraints
Authors: Shevtsova Irina , Tselishchev Mikhail
Published: April 2020

We introduce a generalized stationary renewal distribution (also called the equilibrium transform) for arbitrary distributions with finite nonzero first moment and study its properties. In particular, we prove an optimal moment-type inequality for the Kantorovich distance between a distribution and its equilibrium transform. Using the introduced transform and Stein’s method, we investigate the rate of convergence in the Rényi theorem for the distributions of geometric sums of independent random variables with identical nonzero means and finite second moments without any constraints on their supports. We derive an upper bound for the Kantorovich distance between the normalized geometric random sum and the exponential distribution which has exact order of smallness as the expectation of the geometric number of summands tends to infinity. Moreover, we introduce the so-called asymptotically best constant and present its lower bound yielding the one for the Kantorovich distance under consideration. As a concluding remark, we provide an extension of the obtained estimates of the accuracy of the exponential approximation to non-geometric random sums of independent random variables with non-identical nonzero means.
Lack of Acute Toxicity and Mutagenicity from Recombinant Epinephelus lanceolatus Piscidin Expressed in Pichia pastoris
Authors: Chen Hsiao-Ching , Pan Chieh-Yu , Rajanbabu Venugopal , Lee Yen-Yun , Tsai Wei-Ren , Chen Jyh-Yih
Published: April 2020

The antimicrobial peptide (AMP) piscidin was identified from Epinephelus lanceolatus and demonstrated to possess antimicrobial and immune-related functions. Supplementation of feed with recombinant Epinephelus lanceolatus piscidin (rEP)-expressing yeast pellets may minimize the excessive use of antibiotics and control pathogens in aquaculture or animal husbandry. However, before implementing rEP as a supplement, it is necessary to understand whether it harbors any toxicity. Since toxicological information on the topic is scarce, the present investigation was carried out to test whether rEP exhibits allergenic and/or toxic effects. In an oral acute toxicity test (OECD 425), Sprague Dawley (SD) rats were administered rEP dissolved in reverse osmosis water, yielding an LD50 > 5000 mg/kg (no observed animal death). The compound was therefore classified as non-toxic by oral administration. In an acute respiratory toxicity test (OECD 403), heads and noses of SD rats were exposed to liquid aerosol for 4 h (the highest concentration that could be administered without causing any animal death), and a lethal concentration (LC50) > 0.88 mg/L was obtained. The mass medium aerodynamics diameter (MMAD) of rEP aerosol particles was 8.18 μm and mass medium aerodynamics diameter (GSD) was 3.04, which meant that 25.90% could enter the airway (<4 μm) of a rat, and 58.06% (<10 μm) could be inhaled by humans. An ocular irritation test (OECD 405) with rEP powder was performed on New Zealand White (NZW) rabbits. Signs of irritation included conjunctival swelling and diffuse flushing 1 h after administration. The signs were less apparent after 24 h and disappeared after 72 h. The classification assigned to the powder was mild eye irritation. Skin sensitization was performed for a local lymphoproliferative test (OECD 442B) using BALB/c mice, with the highest soluble concentration of the rEP considered to be 100% test substance; formulations were diluted to 50% and 25%, and bromodeoxyuridine (BrdU) incorporation was used to measure the degree of lymphocyte proliferation. The stimulation indexes (SIs) were 1.06 (100%), 0.44 (50%), and 0.77 (25%), all of which were less than the cutoff value for a positive sensitization result (1.6). Negative response was also seen in the bacterial reverse mutation test (OECD 471), and no chromosomal effects on Chinese hamster ovary (CHO)-K1 cells were observed (OECD 487). Based on these six toxicity tests, rEP showed neither acute toxic effects in experimental animals nor mutagenicity. Thus, rEP can be considered safe for use in subsequent research on its application as a feed additive for poultry, cattle, or aquatic animals.
Identification of an LPS-Induced Chemo-Attractive Peptide from Ciona robusta
Authors: Longo Valeria , Longo Alessandra , Martorana Annamaria , Lauria Antonino , Augello Giuseppa , Azzolina Antonina , Cervello Melchiorre , Colombo Paolo
Published: April 2020

Background: Previously published work has demonstrated that the LPS injection of Ciona robusta leads to the overexpression of a truncated form of an immune-related mRNA (C8short) by means of Ciona robusta (CR) alternative polyadenylation (APA) (CR-APA). Methods: The 3D structure of the C8short-derived Ciona robusta chemo-attractive peptide (CrCP) was evaluated by homology modeling. The biological activity of the CrCP was studied in vitro using a primary human dermal cell line (HuDe). Real-Time PCR was used to investigate the expression levels of genes involved in cell motility. NF-κB signaling was studied by western blotting. Results: In silico modeling showed that CrCP displayed structural characteristics already reported for a short domain of the vertebrate CRK gene, suggesting its possible involvement in cell migration mechanisms. In vitro assays demonstrated that CrCP was capable of inducing the motility of HuDe cells in both wound healing and chemo-attractive experiments. qPCR demonstrated the capability of CrCP to modulate the expression of the matrix metalloproteinase-7 (MMP-7) and E-cadherin genes. Finally, western blot analysis demonstrated that treatment with CrCP induced activation of the NF-κB signaling pathway. Conclusion: Our results describe the characterization of the 3D structure and chemo-attractive activity of an LPS-induced CrCP peptide from Ciona robusta.
Liver Remodeling on CT Examination in Patients with HCV Compensated Cirrhosis Who Achieved Sustained Virological Response after Direct-Acting Antivirals Treatment
Authors: Mihai Florin , Trifan Anca , Stanciu Carol , Singeap Ana Maria , Cucuteanu Bogdan , Lupascu Ursulescu Corina , Pop Corina , Girleanu Irina , Cuciureanu Tudor , Negru Dragos , Cojocariu Camelia
Published: April 2020

Aims: The purpose of this study was to assess the changes in hepatic morphology evaluated by computed tomography (CT) examination in patients with hepatitis C virus (HCV)-related compensated cirrhosis who achieved sustained virologic response (SVR) after direct-acting antivirals (DAAs) treatment. Methods: CT examination was performed in 56 patients with HCV-related compensated cirrhosis before and within 6–18 months after the treatment with Ombitasvir/Paritaprevir/ritonavir + Dasabuvir. The liver CT changes were assessed by measuring liver volume, caudate-right lobe ratio (C/RL), hepatic vessels diameters, periportal widening space, and right posterior notch. Portal trunk, splenic and superior mesenteric vein diameters, as well as spleen volume were assessed as part of portal hypertension. Results: Right hepatic vein diameter was significantly wider after treatment (median: 8.12 mm; IQR: 4.20) than before treatment (median: 6.36 mm; IQR: 3.94) z = −3.894; p < 0.001. The liver volume was significantly higher prior to the treatment (median: 1786.77 mm3; IQR: 879.23) than after treatment (median: 1716.44 mm3; IQR: 840.50), z = −1.970; p = 0.049. Splenic volume was considerably higher before treatment (median: 564.79 mm3; IQR: 342.54) than after (median: 474.45 mm3; IQR: 330.00), z = −2.500; p = 0.012. The other parameters, such as C/RL, periportal space widening, and right hepatic notch showed no significant changes. Conclusions: SVR in patients with HCV-related compensated cirrhosis treated with DAAs is associated with some improvements of hepatic morphology detectable by CT, the most constant being the increase of right hepatic vein diameter.
Autonomic and Cognitive Function Response to Normobaric Hyperoxia Exposure in Healthy Subjects. Preliminary Study
Authors: Kujawski Sławomir , Słomko Joanna , Morten Karl , Murovska Modra , Buszko Katarzyna , Newton Julia , Zalewski Paweł
Published: April 2020

Background and objective: This is the first study to investigate the effect of high-flow oxygen therapy, using a normobaric chamber on cognitive, biochemical (oxidative stress parameters and the level of neurotrophins), cardiovascular and autonomic functioning. Materials and methods: 17 healthy volunteers, eight males and nine females, with a mean age of 37.5 years, were examined. The experimental study involved ten two-hour exposures in a normobaric chamber with a total pressure of 1500 hPa, in air adjusted to 37% oxygen, 1.079% carbon dioxide and 0.44% hydrogen. Cognitive function was assessed by using Trail Making Test parts A, B and difference in results of these tests (TMT A, TMT B and TMT B-A); California Verbal Learning Test (CVLT); Digit symbol substitution test (DSST); and Digit Span (DS). Fatigue (Fatigue Severity Scale (FSS)), cardiovascular, autonomic and baroreceptor functioning (Task Force Monitor) and biochemical parameters were measured before and after intervention. Results: After 10 sessions in the normobaric chamber, significant decreases in weight, caused mainly by body fat % decrease (24.86 vs. 23.93%, p = 0.04 were observed. TMT part A and B results improved (p = 0.0007 and p = 0.001, respectively). In contrast, there was no statistically significant influence on TMT B-A. Moreover, decrease in the number of symbols left after a one-minute test in DSST was noted (p = 0.0001). The mean number of words correctly recalled in the CVLT Long Delay Free Recall test improved (p = 0.002), and a reduction in fatigue was observed (p = 0.001). Biochemical tests showed a reduction in levels of malondialdehyde (p < 0.001), with increased levels of Cu Zn superoxide dismutase (p < 0.001), Neurotrophin 4 (p = 0.0001) and brain-derived neurotrophic factor (p = 0.001). A significant increase in nitric oxide synthase 2 (Z = 2.29, p = 0.02) and Club cell secretory protein (p = 0.015) was also noted. Baroreceptor function was significantly improved after normobaric exposures (p = 0.003). Significant effect of normobaric exposures and BDNF in CVLT Long Delay Free Recall was noted. Conclusions: This study demonstrates that 10 exposures in a normobaric chamber have a positive impact on visual information and set-shifting processing speed and increase auditory-verbal short-term memory, neurotrophic levels and baroreceptor function. A response of the respiratory tract to oxidative stress was also noted. There is a need to rigorously examine the safety of normobaric therapy. Further studies should be carried out with physician examination, both pre and post treatment.
High-Speed Rotary Ultrasonic Elliptical Milling of Ti-6Al-4V Using High-Pressure Coolant
Authors: Zhang Mingliang , Zhang Deyuan , Guo Hailin , Gao Ze , Geng Daxi , Liu Jiajia , Jiang Xinggang
Published: April 2020

High-speed rotary ultrasonic elliptical milling (HRUEM), as a novel ultrasonic vibration cutting method, has been introduced in milling the alloy Ti-6Al-4V. The application of ultrasonic vibration in high-speed milling can help open the cutting contact area intermittently. New cutting effects will happen with full use of the separation effect brought by ultrasonic vibration and the cooling effect brought by a high-pressure coolant (HPC). On the basis of that, this paper firstly introduces HPC into HRUEM of Ti-6Al-4V in the open literature and analyzes the tool-workpiece separation cooling mechanism in HRUEM, including kinematic analysis of tool tip trajectories, tool-workpiece separation principles and high-pressure coolant effects. We have conducted a comprehensive experimental study and the results show when HPC is increased to 200 bar, compared to conventional milling (CM), the tool life in HUREM can be extended by 6.6 times at 80 m/min, 4.2 times at 120 m/min and 2.4 times at 160 m/min. The maximum material removal volume (MRV) for a given new end mill in HRUEM is increased by 657% approximately. When the cutting speed is 80 m/min, the cutting temperature of the workpiece in HRUEM is reduced by 24.1% compared to that of CM. By applying the combination of HPC and tool-workpiece periodic separation, we can significantly enhance the cooling and lubrication efficiency in HRUEM and also inhibit the tool wear mode of adhesive wear typically occurred in CM.
Biological Machine Learning Combined with Campylobacter Population Genomics Reveals Virulence Gene Allelic Variants Cause Disease
Authors: Bandoy DJ Darwin R. , Weimer Bart C.
Published: April 2020

Highly dimensional data generated from bacterial whole-genome sequencing is providing an unprecedented scale of information that requires an appropriate statistical analysis framework to infer biological function from populations of genomes. The application of genome-wide association study (GWAS) methods is an appropriate framework for bacterial population genome analysis that yields a list of candidate genes associated with a phenotype, but it provides an unranked measure of importance. Here, we validated a novel framework to define infection mechanism using the combination of GWAS, machine learning, and bacterial population genomics that ranked allelic variants that accurately identified disease. This approach parsed a dataset of 1.2 million single nucleotide polymorphisms (SNPs) and indels that resulted in an importance ranked list of associated alleles of porA in Campylobacter jejuni using spatiotemporal analysis over 30 years. We validated this approach using previously proven laboratory experimental alleles from an in vivo guinea pig abortion model. This framework, termed μPathML, defined intestinal and extraintestinal groups that have differential allelic porA variants that cause abortion. Divergent variants containing indels that defeated automated annotation were rescued using biological context and knowledge that resulted in defining rare, divergent variants that were maintained in the population over two continents and 30 years. This study defines the capability of machine learning coupled with GWAS and population genomics to simultaneously identify and rank alleles to define their role in infectious disease mechanisms.