bluuebunny/crossref_metadata_2025 huggingface dataset:
Mortality/Longevity Risk-Minimization with or without Securitization
Authors: Choulli Tahir , Daveloose Catherine , Vanmaele Michèle
Published: July 2021

This paper addresses the risk-minimization problem, with and without mortality securitization, à la Föllmer–Sondermann for a large class of equity-linked mortality contracts when no model for the death time is specified. This framework includes situations in which the correlation between the market model and the time of death is arbitrary general, and hence leads to the case of a market model where there are two levels of information—the public information, which is generated by the financial assets, and a larger flow of information that contains additional knowledge about the death time of an insured. By enlarging the filtration, the death uncertainty and its entailed risk are fully considered without any mathematical restriction. Our key tool lies in our optional martingale representation, which states that any martingale in the large filtration stopped at the death time can be decomposed into precise orthogonal local martingales. This allows us to derive the dynamics of the value processes of the mortality/longevity securities used for the securitization, and to decompose any mortality/longevity liability into the sum of orthogonal risks by means of a risk basis. The first main contribution of this paper resides in quantifying, as explicitly as possible, the effect of mortality on the risk-minimizing strategy by determining the optimal strategy in the enlarged filtration in terms of strategies in the smaller filtration. Our second main contribution consists of finding risk-minimizing strategies with insurance securitization by investing in stocks and one (or more) mortality/longevity derivatives such as longevity bonds. This generalizes the existing literature on risk-minimization using mortality securitization in many directions.
Fully Convolutional Approaches for Numerical Approximation of Turbulent Phases in Solar Adaptive Optics
Authors: Riesgo Francisco García , Gómez Sergio Luis Suárez , Alonso Enrique Díez , González-Gutiérrez Carlos , Santos Jesús Daniel
Published: July 2021

Information on the correlations from solar Shack–Hartmann wavefront sensors is usually used for reconstruction algorithms. However, modern applications of artificial neural networks as adaptive optics reconstruction algorithms allow the use of the full image as an input to the system intended for estimating a correction, avoiding approximations and a loss of information, and obtaining numerical values of those correlations. Although studied for night-time adaptive optics, the solar scenario implies more complexity due to the resolution of the solar images potentially taken. Fully convolutional neural networks were the technique chosen in this research to address this problem. In this work, wavefront phase recovery for adaptive optics correction is addressed, comparing networks that use images from the sensor or images from the correlations as inputs. As a result, this research shows improvements in performance for phase recovery with the image-to-phase approach. For recovering the turbulence of high-altitude layers, up to 93% similarity is reached.
Optimized Application of Sustainable Development Strategy in International Engineering Project Management
Authors: Zhou Zhiwu , Alcalá Julián , Yepes Víctor
Published: July 2021

The aim of this paper is to establish an international framework for sustainable project management in engineering, to make up the lack of research in this field, and to propose a scientific theoretical basis for the establishment of a new project management system. The article adopts literature review, mathematical programming algorithm and case study as the research method. The literature review applied the visual clustering research method and analyzed the results of 21-year research in this field. As a result, the project management system was found to have defects and deficiencies. A mathematical model was established to analyze the composition and elements of the optimized international project management system. The case study research selected large bridges for analysis and verified the superiority and practicability of the theoretical system. Thus, the goal of sustainable development of bridges was achieved. The value of this re-search lies in establishing a comprehensive international project management system model; truly integrating sustainable development with project management; providing new research frames and management models to promote the sustainable development of the construction industry.
Algebraic Reflexivity of Non-Canonical Isometries on Lipschitz Spaces
Authors: Jiménez-Vargas Antonio , Ramírez María Isabel
Published: July 2021

Let Lip([0,1]) be the Banach space of all Lipschitz complex-valued functions f on [0,1], equipped with one of the norms: fσ=|f(0)|+f′L∞ or fm=max|f(0)|,f′L∞, where ·L∞ denotes the essential supremum norm. It is known that the surjective linear isometries of such spaces are integral operators, rather than the more familiar weighted composition operators. In this paper, we describe the topological reflexive closure of the isometry group of Lip([0,1]). Namely, we prove that every approximate local isometry of Lip([0,1]) can be represented as a sum of an elementary weighted composition operator and an integral operator. This description allows us to establish the algebraic reflexivity of the sets of surjective linear isometries, isometric reflections, and generalized bi-circular projections of Lip([0,1]). Additionally, some complete characterizations of such reflections and projections are stated.
Model for Reconstruction of γ-Background during Liquid Atmospheric Precipitation
Authors: Yakovleva Valentina , Zelinskiy Aleksey , Parovik Roman , Yakovlev Grigorii , Kobzev Aleksey
Published: July 2021

With regard to reconstructing the gamma background dose rate, existing models are either empirical with limited applicability or have many unknown input parameters, which complicates their application in practice. Due to this, there is a need to search for a new approach and build a convenient, easily applicable and universal model. The paper proposes a mathematical model for reconstructing the temporal evolution of the ambient equivalent γ-radiation dose rate during rain episodes, depending on the density of radon flux from the soil surface, as well as the duration and intensity of rain. The efficiency of the model is confirmed by the high coefficient of determination (R2 = 0.81–0.99) between the measured and reconstructed ambient equivalent dose rate during periods of rain, the simulation of which was performed using Wolfram Mathematica. An algorithm was developed for restoring the dynamics of the ambient equivalent γ-radiation dose rate during rainfall. Based on the results obtained, assumptions were made where the washout of radionuclides originates. The influence of the radionuclides ratio on the increase in the total γ-radiation dose rate was investigated.
Right Ventricular Functionality Following Hemodialysis Initiation in End-Stage Kidney Disease—A Single-Center, Prospective, Cohort Study
Authors: Tanasa Ana , Burlacu Alexandru , Popa Iolanda Valentina , Covic Adrian
Published: July 2021

Background and Objectives: Two-dimensional speckle tracking echocardiography (2D-STE) is viewed as an outstanding technique, competent of uncovering earlier subclinical myocardial anomalies compared to conventional echocardiography. A few endeavors adopted 2D-STE as a tool to estimate right ventricular (RV) function in subjects with end-stage kidney disease (ESKD). There is no published prospective study on an adult ESKD cohort exploring the consequences of commencing elective hemodialysis (HD) on RV behavior. Materials and Methods: We investigated the RV systolic function using traditional (tricuspid annular plane systolic excursion—TAPSE, RV fractional area change—FAC) and 2D-STE (RV free wall longitudinal strain—RVFWLS) parameters following the initiation of HD. We enrolled 79 consecutive patients with ESKD and assessed them in four steps—at baseline, before HD, and at 3, 6, and 12 months. Results: RVFWLS, FAC, and TAPSE values had a significant increase at 3, 6, and 12 months from baseline (p < 0.001) and a significant increase at 6 months from 3 months (p < 0.001). However, differences between 12 months and 6 months were not significant (p > 0.05) according to Dunn–Bonferroni post hoc tests. Seventeen deaths were recorded before the completion of the study. RVFWLS, FAC, and TAPSE values significantly decreased at 3 and 6 months in all 17 deceased patients, in clear opposition with the values survivors had. All the studied parameters had a significant prediction power on mortality (p < 0.001) having an outstanding performance: baseline-RVFWLS (AUC: 1.000 (95% C.I.: 1.000–1.000)), baseline-FAC (AUC: 0.974 (95% C.I.: 0.942–1.000)), and baseline-TAPSE (AUC: 0.962 (95% C.I.: 0.920–1.000). Conclusions: Our study is the first to investigate RV function by 2D-STE and correlate it with traditional methods in patients with ESKD before and after the initiation of HD. RV function was significantly ameliorated at 3, 6, and 12 months compared to the pre-HD values. FAC and RVFWLS gain an outstanding prognostic role on mortality in this population.
Channelized CO2-Rich Fluid Activity along a Subduction Interface in the Paleoproterozoic Wutai Complex, North China Craton
Authors: Wang Bin , Tian Wei , Fu Bin , Fang Jia-Qi
Published: July 2021

Greenschist facies metabasite (chlorite schist) and metasediments (banded iron formation (BIF)) in the Wutai Complex, North China Craton recorded extensive fluid activities during subduction-related metamorphism. The pervasive dolomitization in the chlorite schist and significant dolomite enrichment at the BIF–chlorite schist interface support the existence of highly channelized updip transportation of CO2-rich hydrothermal fluids. Xenotime from the chlorite schist has U concentrations of 39–254 ppm and Th concentrations of 121–2367 ppm, with U/Th ratios of 0.11–0.62, which is typical of xenotime precipitated from circulating hydrothermal fluids. SHRIMP U–Th–Pb dating of xenotime determines a fluid activity age of 1.85 ± 0.07 Ga. The metasomatic dolomite has δ13CV-PDB from −4.17‰ to −3.10‰, which is significantly lower than that of carbonates from greenschists, but similar to the fluid originated from Rayleigh fractionating decarbonation at amphibolite facies metamorphism along the regional geotherm (~15 °C/km) of the Wutai Complex. The δ18OV-SMOW values of the dolomite (12.08–13.85‰) can also correspond to this process, considering the contribution of dehydration. Based on phase equilibrium modelling, we ascertained that the hydrothermal fluid was rich in CO2, alkalis, and silica, with X(CO2) in the range of 0.24–0.28. All of these constraints suggest a channelized CO2-rich fluid activity along the sediment–basite interface in a warm Paleoproterozoic subduction zone, which allowed extensive migration and sequestration of volatiles (especially carbon species) beneath the forearc.
Spectroscopy and Microscopy of Corundum from Primary Deposits Found in Greece
Authors: Karantoni Vilelmini , Karampelas Stefanos , Voudouris Panagiotis , Melfos Vasilios , Papadopoulou Lambrini , Soldatos Triantafyllos , Mavrogonatos Constantinos
Published: July 2021

Corundum primary deposits in Greece occur in four locations: Paranesti in Drama and Gorgona in Xanthi, both belonging to the wider Rhodope Massif, as well as, Ikaria island and Kinidaros in Naxos island, both belonging to Attic-Cycladic Massif. Eight samples were examined with spectroscopic methods (FTIR, UV-Vis, EDXRF) in order to better characterize these four primary deposits: two pink sapphires from Paranesti, a pink and a blue sapphire from Gorgona, two blue sapphires from Ikaria and three blue sapphires from Kinidaros. Under the microscope, all samples present characteristics linked to post-crystallization deformation, decreasing their gem quality. The FTIR absorption spectra of all samples present in different relative intensities, bands of boehmite, diaspore, goethite, mica and/or chlorite inclusions and CO2 in fluid inclusions. Boehmite and diaspore inclusions are most likely epigenetic. In the UV-Vis spectra, the pink color of the samples is linked with Cr3+ absorptions and the blue color with absorptions due to Fe2+-Ti4+ intervalence charge transfer. EDXRF analyses in the studied samples show relatively high titanium and iron concentrations that are related with mineral inclusions. Gallium is slightly variable in samples from different regions; also, different colored samples from Gorgona present diverse gallium content.
Mercury Anomaly in Oligocene–Miocene Maykop Group Sediments (Caucasus Continental Collision Zone): Mercury Hosts, Distribution, and Sources
Authors: Kokh Svetlana , Sokol Ella , Gustaytis Maria
Published: July 2021

The Oligocene–Miocene Maykop Group sediments, mainly composed of illite–smectite, store mercury in strongly variable concentrations from 10 to 920 μg/kg. Extremely high Hg levels (98–920 μg/kg) coupled with abnormal mercury-to-total organic carbon (TOC) ratios (Hg/TOC = 109 to 3000 μg/kg/wt%; TOC = 0.2 wt% to 1.2 wt%) were measured in the Middle Maykop marine shales that were deposited in the deepwater Indol–Kuban Basin under anoxic conditions. The Middle Maykop shales contain up to 70% of total mercury in sulfide form. In heavy mineral fractions, abundant Hg-bearing pyrite (with up to 4810 µg/kg Hg in hand-picked concentrates) is accompanied by sporadic cinnabar. Relative to the Middle Maykop sediments, the Upper Maykop shales have much lower Hg concentrations and Hg/TOC ratios: 10 to 63 μg/kg (34 μg/kg on average) and 7.7 to 137 μg/kg/wt% (39 μg/kg/wt% on average), respectively. Mercury sequestration is inferred to occur mostly by binding in sulfide hosts in the Middle Maykop anoxic deep-sea sediments and in organic matter, Fe3+-(oxy)hydroxides, and clay particles in the Upper Maykop shales which were deposited in a more oxygenated environment. Mercury inputs to the marine shales during Maykopian sedimentation were possibly associated with local Oligocene–Lower Miocene volcanic activity in the Caucasus Continental Collision Zone. At the same time, the mode of Hg binding in sediments was controlled by redox conditions which changed from anoxic to disoxic and suboxic at the Middle-to-Upper Maykop transition.
What Is the Nutritional Composition of Ultra-Processed Food Marketed in Italy?
Authors: Lorenzoni Giulia , Di Benedetto Rita , Silano Marco , Gregori Dario
Published: July 2021

The present study aimed to provide a descriptive analysis of the nutrient profile of ultra-processed foods (UPFs) marketed in Italy according to three front-of-pack labeling (FOPL) schemes implemented by France, i.e., the Nutriscore; by the United Kingdom, i.e., Multiple Traffic Lights (MTL); and by Italy, i.e., the NutrInform battery. The analysis was made in fourteen food product categories, corresponding to 124 foods. The application of the Nutriscore scheme showed that a significant proportion of foods (23%) were awarded an A or B. Furthermore, the analysis according to the MTL showed that food products that were above the threshold (“red”) for fat, saturated fats, sugars, and salt ranged from 13% to 31%. Interestingly, even though all foods considered in the analysis were UPF, they were heterogeneous in nutritional composition, as demonstrated by the FOPL schemes applied, showing that UPF represent a heterogeneous group of foods with different characteristics. Such a finding may have relevant implications for epidemiological studies that analyze the association between UPF consumption and health outcomes, suggesting the need for better characterization of the effects of UPF intake on human health.
Design, Synthesis, and Utility of Defined Molecular Scaffolds
Authors: Sato Daisuke , Wu Zhiyuan , Fujita Hikaru , Lindsey Jonathan
Published: July 2021

A growing theme in chemistry is the joining of multiple organic molecular building blocks to create functional molecules. Diverse derivatizable structures—here termed “scaffolds” comprised of “hubs”—provide the foundation for systematic covalent organization of a rich variety of building blocks. This review encompasses 30 tri- or tetra-armed molecular hubs (e.g., triazine, lysine, arenes, dyes) that are used directly or in combination to give linear, cyclic, or branched scaffolds. Each scaffold is categorized by graph theory into one of 31 trees to express the molecular connectivity and overall architecture. Rational chemistry with exacting numbers of derivatizable sites is emphasized. The incorporation of water-solubilization motifs, robust or self-immolative linkers, enzymatically cleavable groups and functional appendages affords immense (and often late-stage) diversification of the scaffolds. Altogether, 107 target molecules are reviewed along with 19 syntheses to illustrate the distinctive chemistries for creating and derivatizing scaffolds. The review covers the history of the field up through 2020, briefly touching on statistically derivatized carriers employed in immunology as counterpoints to the rationally assembled and derivatized scaffolds here, although most citations are from the past two decades. The scaffolds are used widely in fields ranging from pure chemistry to artificial photosynthesis and biomedical sciences.
Whole-Genome Sequencing Analysis to Identify Infection with Multiple Species of Nontuberculous Mycobacteria
Authors: Khieu Visal , Ananta Pimjai , Kaewprasert Orawee , Laohaviroj Marut , Namwat Wises , Faksri Kiatichai
Published: July 2021

Mixed infection with multiple species of nontuberculous mycobacteria (NTM) is difficult to identify and to treat. Current conventional molecular-based methods for identifying mixed infections are limited due to low specificity. Here, we evaluated the utility of whole-genome sequencing (WGS) analysis to detect and identify mixed NTM infections. Analytical tools used included PubMLST, MetaPhlAn3, Kraken2, Mykrobe-Predictor and analysis of heterozygous SNP frequencies. The ability of each to identify mixed infections of NTM species was compared. Sensitivity was tested using 101 samples (sequence sets) including 100 in-silico simulated mixed samples with various proportions of known NTM species and one sample of known mixed NTM species from a public database. Single-species NTM control samples (155 WGS samples from public databases and 15 samples from simulated reads) were tested for specificity. Kraken2 exhibited 100% sensitivity and 98.23% specificity for detection and identification of mixed NTM species with accurate estimation of relative abundance of each species in the mixture. PubMLST (99% and 96.47%) and MetaPhlAn3 (95.04% and 83.52%) had slightly lower sensitivity and specificity. Mykrobe-Predictor had the lowest sensitivity (57.42%). Analysis of read frequencies supporting single nucleotide polymorphisms (SNPs) could not detect mixed NTM samples. Clinical NTM samples (n = 16), suspected on the basis of a 16S–23S rRNA gene sequence-based line-probe assay (LPA) to contain more than one NTM species, were investigated using WGS-analysis tools. This identified only a small proportion (37.5%, 6/16 samples) of the samples as mixed infections and exhibited only partial agreement with LPA results. LPAs seem to be inadequate for detecting mixed NTM species infection. This study demonstrated that WGS-analysis tools can be used for diagnosis of mixed infections with different species of NTM.
Analysis of Boswellic Acid Contents and Related Pharmacological Activities of Frankincense-Based Remedies That Modulate Inflammation
Authors: Börner Friedemann , Werner Markus , Ertelt Johannes , Meins Jürgen , Abdel-Tawab Mona , Werz Oliver
Published: July 2021

Extracts of frankincense, the gum resin of Boswellia species, have been extensively used in traditional folk medicine since ancient times and are still of great interest as promising anti-inflammatory remedies in Western countries. Despite their common therapeutic use and the intensive pharmacological research including studies on active ingredients, modes of action, bioavailability, pharmacokinetics, and clinical efficacy, frankincense preparations are available as nutraceuticals but have not yet approved as a drug on the market. A major issue of commercially available frankincense nutraceuticals is the striking differences in their composition and quality, especially related to the content of boswellic acids (BAs) as active ingredients, mainly due to the use of material from divergent Boswellia species but also because of different work-up and extraction procedures. Here, we assessed three frequently used frankincense-based preparations for their BA content and the interference with prominent pro-inflammatory actions and targets that have been proposed, that is, 5-lipoxygenase and leukotriene formation in human neutrophils, microsomal prostaglandin E2 synthase-1, and inflammatory cytokine secretion in human blood monocytes. Our data reveal striking differences in the pharmacological efficiencies of these preparations in inflammation-related bioassays which obviously correlate with the amounts of BAs they contain. In summary, high-quality frankincense extracts display powerful anti-inflammatory effectiveness against multiple targets which can be traced back to BAs as bioactive ingredients.
Insulin-Mimic Components in Acer truncatum Leaves: Bio-Guided Isolation, Annual Variance Profiling and Regulating Pathway Investigated by Omics
Authors: Zhang Xiao-Yue , Liu Yi-Han , Liu Da-Zhi , Xu Jia-Yang , Zhang Qiang
Published: July 2021

Insulin mimic can promote transporting glucose to muscle tissue and accelerate glucose consumption. It is commonly occurring in many functional foods or traditional medicines. Anti-diabetes molecules from food sources are highly safe and suitable for long-term use to prevent early diabetes. The leaves of Acer truncatum was found glucose uptake promotion in our phenotypic screening. However, its bioactive components and mechanism are still unclear. We collected leaves from trees of different ages (2, 3, 4, 7 and 11 years old) and profiled the ingredients by LC-MS/MS. The essential active component (myricitrin) was acquired following bio-guide on a whole organism Zebrafish (Danio rerio). Its content in the leaves was not affected by tree ages. Therefore, myricitrin can serve as a quality mark for functional foods derived from A. truncatum leaves. The transcriptomic and metabolomic analysis in Zebrafish explored the differentially expressed genes and metabolites. Based on joint-pathway enrichment and qRT-PCR verification, the critical bioactive component myricitrin was found to affect toll-like receptors signaling pathways to regulate glucose uptake. Our findings disclosed a bioactive marker (myricitrin) in A. truncatum leaves and explored its regulation mechanism, which rationalized the anti-diabetes function of the herbal food.
COVID-19: Failure of the DisCoVeRy Clinical Trial, and Now–New Hopes?
Authors: Vanden Eynde Jean Jacques
Published: July 2021

The DisCoVeRy clinical trial aimed at the evaluation of four treatments for patients suffering from severe to critical COVID-19: Hydroxychloroquine, eventually associated with azithromycin; the combination lopinavir/ritonavir; the combination with the addition of interferon β-1a; remdesivir. The trial was discontinued due to the lack of positive results. Meanwhile, many other potential options have been considered either to target the virus itself, the interactions with the host cells, or the cytokine storm frequently observed during the infection. Several of those options are briefly reviewed. They include vaccines, small molecules, antibodies, and stem cells.
Genome-Wide Association Studies for Sex Determination and Cross-Compatibility in Water Yam (Dioscorea alata L.)
Authors: Mondo Jean M. , Agre Paterne A. , Asiedu Robert , Akoroda Malachy O. , Asfaw Asrat
Published: July 2021

Yam (Dioscorea spp.) species are predominantly dioecious, with male and female flowers borne on separate individuals. Cross-pollination is, therefore, essential for gene flow among and within yam species to achieve breeding objectives. Understanding genetic mechanisms underlying sex determination and cross-compatibility is crucial for planning a successful hybridization program. This study used the genome-wide association study (GWAS) approach for identifying genomic regions linked to sex and cross-compatibility in water yam (Dioscorea alata L.). We identified 54 markers linked to flower sex determination, among which 53 markers were on chromosome 6 and one on chromosome 11. Our result ascertained that D. alata is characterized by the male heterogametic sex determination system (XX/XY). The cross-compatibility indices, average crossability rate (ACR) and percentage high crossability (PHC), were controlled by loci on chromosomes 1, 6 and 17. Of the significant loci, SNPs located on chromosomes 1 and 17 were the most promising for ACR and PHC, respectively, and should be validated for use in D. alata hybridization activities to predict cross-compatibility success. A total of 61 putative gene/protein families with direct or indirect influence on plant reproduction were annotated in chromosomic regions controlling the target traits. This study provides valuable insights into the genetic control of D. alata sexual reproduction. It opens an avenue for developing genomic tools for predicting hybridization success in water yam breeding programs.
Optimized ANFIS Model Using Aquila Optimizer for Oil Production Forecasting
Authors: AlRassas Ayman Mutahar , Al-qaness Mohammed A. A. , Ewees Ahmed A. , Ren Shaoran , Abd Elaziz Mohamed , Damaševičius Robertas , Krilavičius Tomas
Published: July 2021

Oil production forecasting is one of the essential processes for organizations and governments to make necessary economic plans. This paper proposes a novel hybrid intelligence time series model to forecast oil production from two different oil fields in China and Yemen. This model is a modified ANFIS (Adaptive Neuro-Fuzzy Inference System), which is developed by applying a new optimization algorithm called the Aquila Optimizer (AO). The AO is a recently proposed optimization algorithm that was inspired by the behavior of Aquila in nature. The developed model, called AO-ANFIS, was evaluated using real-world datasets provided by local partners. In addition, extensive comparisons to the traditional ANFIS model and several modified ANFIS models using different optimization algorithms. Numeric results and statistics have confirmed the superiority of the AO-ANFIS over traditional ANFIS and several modified models. Additionally, the results reveal that AO is significantly improved ANFIS prediction accuracy. Thus, AO-ANFIS can be considered as an efficient time series tool.
Smart Cleaner: A New Autonomous Indoor Disinfection Robot for Combating the COVID-19 Pandemic
Authors: Ruan Kaicheng , Wu Zehao , Xu Qingsong
Published: July 2021

The COVID-19 pandemic imposes an increasing demand for service robots as a substitute for humans to conduct various types of work in contaminated areas. Such work includes logistics, patient care, and disinfection, which can reduce the risk of human exposure to the highly contagious and deadly virus. This paper presents the design and development of Smart Cleaner, which is a new cost-effective autonomous indoor disinfection robot. It integrates a wheeled mobile robot platform and a hydrogen peroxide atomization device for automated disinfection operation in the complex indoor environment. Through the system integration of various hardware components and software programming, a prototype of the disinfection robot has been fabricated for experimental investigation. A simulation study of the drymist hydrogen peroxide disinfection model was carried out to understand the diffusion of disinfectant in a room environment. The effectiveness of the developed robot was verified in practical scenarios, such as hospital, hotel, office, and laboratory. The effect of disinfection was validated by a qualified third-party testing agency. Results demonstrate the high efficiency of the developed disinfection robot dedicated to autonomous indoor disinfection work.
A Rigorous Observation Model for the Risley Prism-Based Livox Mid-40 Lidar Sensor
Authors: Brazeal Ryan G. , Wilkinson Benjamin E. , Hochmair Hartwig H.
Published: July 2021

Modern lidar sensors are continuing to decrease in size, weight, and cost, but the demand for fast, abundant, and high-accuracy lidar observations is only increasing. The Livox Mid-40 lidar sensor was designed for use within sense-and-avoid navigation systems for autonomous vehicles, but has also found adoption within aerial mapping systems. In order to characterize the overall quality of the point clouds from the Mid-40 sensor and enable sensor calibration, a rigorous model of the sensor’s raw observations is needed. This paper presents the development of an angular observation model for the Mid-40 sensor, and its application within an extended Kalman filter that uses the sensor’s data to estimate the model’s operating parameters, systematic errors, and the instantaneous prism rotation angles for the Risley prism optical steering mechanism. The analysis suggests that the Mid-40’s angular observations are more accurate than the specifications provided by the manufacturer. Additionally, it is shown that the prism rotation angles can be used within a planar constrained least-squares adjustment to theoretically improve the accuracy of the angular observations of the Mid-40 sensor.
Scattered Far-Field Sampling in Multi-Static Multi-Frequency Configuration
Authors: Maisto Maria Antonia , Masoodi Mehdi , Leone Giovanni , Solimene Raffaele , Pierri Rocco
Published: July 2021

This paper deals with an inverse scattering problem under a linearized scattering model for a multi-static/multi-frequency configuration. The focus is on the determination of a sampling strategy that allows the reduction of the number of measurement points and frequencies and at the same time keeping the same achievable performance in the reconstructions as for full data acquisition. For the sake of simplicity, a 2D scalar geometry is addressed, and the scattered far-field data are collected. The relevant scattering operator exhibits a singular value spectrum that abruptly decays (i.e., a step-like behavior) beyond a certain index, which identifies the so-called number of degrees of freedom (NDF) of the problem. Accordingly, the sampling strategy is derived by looking for a discrete finite set of data points for which the arising semi-discrete scattering operator approximation can reproduce the most significant part of the singular spectrum, i.e., the singular values preceding the abrupt decay. To this end, the observation variables are suitably transformed so that Fourier-based arguments can be used. The arising sampling grid returns several data that is close to the NDF. Unfortunately, the resulting data points (in the angle-frequency domain) leading to a complicated measurement configuration which requires collecting the data at different spatial positions for each different frequency. To simplify the measurement configuration, a suboptimal sampling strategy is then proposed which, by an iterative procedure, enforces the sampling points to belong to a rectangular grid in the angle-frequency domain. As a result of this procedure, the overall data points (i.e., the couples angle-frequency) actually increase but the number of different angles and frequencies reduce and lead to a measurement configuration that is more practical to implement. A few numerical examples are included to check the proposed sampling scheme.
Urban Vegetation Mapping from Aerial Imagery Using Explainable AI (XAI)
Authors: Abdollahi Arnick , Pradhan Biswajeet
Published: July 2021

Urban vegetation mapping is critical in many applications, i.e., preserving biodiversity, maintaining ecological balance, and minimizing the urban heat island effect. It is still challenging to extract accurate vegetation covers from aerial imagery using traditional classification approaches, because urban vegetation categories have complex spatial structures and similar spectral properties. Deep neural networks (DNNs) have shown a significant improvement in remote sensing image classification outcomes during the last few years. These methods are promising in this domain, yet unreliable for various reasons, such as the use of irrelevant descriptor features in the building of the models and lack of quality in the labeled image. Explainable AI (XAI) can help us gain insight into these limits and, as a result, adjust the training dataset and model as needed. Thus, in this work, we explain how an explanation model called Shapley additive explanations (SHAP) can be utilized for interpreting the output of the DNN model that is designed for classifying vegetation covers. We want to not only produce high-quality vegetation maps, but also rank the input parameters and select appropriate features for classification. Therefore, we test our method on vegetation mapping from aerial imagery based on spectral and textural features. Texture features can help overcome the limitations of poor spectral resolution in aerial imagery for vegetation mapping. The model was capable of obtaining an overall accuracy (OA) of 94.44% for vegetation cover mapping. The conclusions derived from SHAP plots demonstrate the high contribution of features, such as Hue, Brightness, GLCM_Dissimilarity, GLCM_Homogeneity, and GLCM_Mean to the output of the proposed model for vegetation mapping. Therefore, the study indicates that existing vegetation mapping strategies based only on spectral characteristics are insufficient to appropriately classify vegetation covers.
Impacts of Stroke on Muscle Perceptions and Relationships with the Motor and Functional Performance of the Lower Extremities
Authors: Liu Wan-Ju , Lin Li-Fong , Chiang Shang-Lin , Lu Liang-Hsuan , Chen Chao-Ying , Lin Chueh-Ho
Published: July 2021

Stroke results in paretic limb disabilities, but few studies have investigated the impacts of stroke on muscle perception deficits in multiaxis movements and related functional changes. Therefore, this study aimed to investigate stroke-related changes in muscle perceptions using a multiaxis ankle haptic interface and analyze their relationships with various functions. Sixteen stroke patients and 22 healthy participants performed active reproduction tests in multiaxis movements involving the tibialis anterior (TA), extensor digitorum longus (EDL), peroneus longus, and flexor digitorum longus (FDL) of the ankle joint. The direction error (DE), absolute error (AE), and variable error (VE) were calculated. The lower extremity of Fugl-Meyer Assessment (FMA-LE), Barthel Index (BI), Postural Assessment Scale for Stroke Patients, Tinetti Performance-Oriented Mobility Assessment (POMA), and 10-m walk test (10MWT) were evaluated. VE of EDL for the paretic ankle was significantly lower than that for the nonparetic ankle (p = 0.009). AE of TA, EDL, and FDL and VE of EDL and FDL of muscle perceptions were significantly lower in healthy participants than in stroke patients (p < 0.05 for both). DE of TA for the paretic ankle was moderately correlated with FMA-LE (r = −0.509) and POMA (r = −0.619) scores. AE and VE of EDL for the paretic ankle were moderately correlated with the 10MWT score (r = 0.515 vs. 0.557). AE of FDL for the paretic ankle was also moderately correlated with BI (r = −0.562). This study indicated poorer accuracy and consistency in muscle perception for paretic ankles, which correlated with lower limb functions of stroke patients.
Initial Positive Indications with Wearable Fitness Technology Followed by Relapse: What’s Going On?
Authors: Parker James , Johnson Urban , Ivarsson Andreas
Published: July 2021

The motivational influence of wearable fitness technology (WFT) on increasing physical activity (PA) is unclear, and improvements in PA have been shown to be driven by both intrinsic and extrinsic motivation. In the current study, PA (daily number of steps), moderate to vigorous intensity physical activity, and muscular strength training were measured over 6 months on, originally, 16 randomly selected sedentary community workers (mean age = 51 years). Moreover, self-determined motivation (Behavioral Regulation in Exercise Questionnaire-2) was measured before, midway, and after a 6-month intervention program that included motivational interviewing, as well as the use of WFT and a structured outdoor gym program. Our findings showed WFT, in combination with motivational interviewing, initially helped the participants meet recommended guidelines for PA in terms of at least 10,000 steps per day, and at least 150 min of moderate aerobic activity per week. There was a large decrease in participants’ PA and increase in introjected motivation between the first half (3 months) and the second half of the intervention (6 months). The increase in introjected motivation suggests that toward the end of the 6-month intervention, participants engaged in PA to satisfy external demands or avoid guilt, which may lead to less-persistent behavior change.
Optimal Operation of Stand-Alone Microgrid Considering Emission Issues and Demand Response Program Using Whale Optimization Algorithm
Authors: Tahmasebi Mehrdad , Pasupuleti Jagadeesh , Mohamadian Fatemeh , Shakeri Mohammad , Guerrero Josep M. , Basir Khan M. Reyasudin , Nazir Muhammad Shahzad , Safari Amir , Bazmohammadi Najmeh
Published: July 2021

Microgrids are new technologies for integrating renewable energies into power systems. Optimal operation of renewable energy sources in standalone micro-grids is an intensive task due to the continuous variation of their output powers and intermittant nature. This work addresses the optimum operation of an independent microgrid considering the demand response program (DRP). An energy management model with two different scenarios has been proposed to minimize the costs of operation and emissions. Interruptible/curtailable loads are considered in DRPs. Besides, due to the growing concern of the developing efficient optimization methods and algorithms in line with the increasing needs of microgrids, the focus of this study is on using the whale meta-heuristic algorithm for operation management of microgrids. The findings indicate that the whale optimization algorithm outperforms the other known algorithms such as imperialist competitive and genetic algorithms, as well as particle swarm optimization. Furthermore, the results show that the use of DRPS has a significant impact on the costs of operation and emissions.
Theft Prediction Model Based on Spatial Clustering to Reflect Spatial Characteristics of Adjacent Lands
Authors: Kim Dongyoung , Jung Sungwon , Jeong Yongwook
Published: July 2021

Previous studies have shown that when a crime occurs, the risk of crime in adjacent areas increases. To reflect this, previous grid-based crime prediction studies combined all the cells surrounding the event location to be predicted for use in model training. However, the actual land is continuous rather than a set of independent cells as in a geographic information system. Because the patterns that occur according to the detailed method of crime vary, it is necessary to reflect the spatial characteristics of the adjacent land in crime prediction. In this study, cells with similar spatial characteristics were classified using the Max-p region model (a spatial clustering technique), and the performance was compared to the existing method using random forest (a tree-based machine learning model). According to the results, the F1 score of the model using spatial clustering increased by approximately 2%. Accordingly, there are differences in the physical environmental factors influenced by the detailed method of crime. The findings reveal that crime involving the same offender is likely to occur around the area of the original crime, indicating that a repeated crime is likely in areas with similar spatial features to the area where the crime occurred.
A Non-Market Valuation Approach to Environmental Cost-Benefit Analysis for Sanitary Landfill Project Appraisal
Authors: Nik Ab Rahim Nik Nor Rahimah , Othman Jamal , Hanim Mohd Salleh Norlida , Chamhuri Norshamliza
Published: July 2021

Extensive non-engineered landfilling practice in developing countries has raised environmental concerns, but operating a sanitary landfill appears infeasible due to financial incapability. This study aims to determine the feasibility of a sanitary landfill project by including its environmental values into the project appraisal while simultaneously applying three policy-relevant methods—non-market valuation, benefits transfer, and cost-benefit analysis—in two study areas in Peninsular Malaysia. The non-market valuation study used choice modeling, a questionnaire-based technique, to elicit willingness to pay among 624 households toward the environmental attributes of the sanitary landfill. Their responses resulted in the monetary values of the environmental attributes by referring to implicit prices of leachate discharge, bad odor, disease vector and view. The implicit prices of bad odor (RM2.29 per month) and view (RM3.59 per month) in the two study areas were transferable and used as a proxy of additional solid waste disposal payment in environmental cost-benefit analysis. Positive net present value offers empirical evidence of the feasibility of the sanitary landfill project. The findings show that the inclusion of environmental values in project appraisals increases the chances of implementing sanitary landfills, providing a new approach to address the environmental concerns in developing countries. Future research should consider the external costs along with the external benefits to allow for a comprehensive comparison between environmental values in environmental cost-benefit analysis.
Agrometeorological Requirements of Maize Crop Phenology for Sustainable Cropping—A Historical Review for Romania
Authors: Vâtcă Sorin Daniel , Stoian Valentina Ancuța , Man Titus Cristian , Horvath Csaba , Vidican Roxana , Gâdea Ștefania , Vâtcă Anamaria , Rotaru Ancuța , Vârban Rodica , Cristina Moldovan , Stoian Vlad
Published: July 2021

Identifying regional variations and agronomical records can turn into a function of magnitude and timing for sustainable maize production. The crop characteristics are directly related with the temperature and precipitation from the growing season. Therefore, the main aim of this study was to highlight maize crop requirements from the most suggestive records from Romania. A literature search was performed based on keywords related to both maize crop and agrometeorological requirements. After the evaluation of the temperature requirements on maize phenology’s principal stages, some inconsistencies were identified. These are related to the leaf development stage and the development of the fruit stage, where the minimum temperature interval overlaps with the optimum. A wide variety of assessments were also made, taking into account mainly the monthly temperature and precipitation requirements. The number of principal growth stages assessed differed greatly from one source to another. The growth degree days has been incoherently expressed and calculated, and these details must be taken into account for developing further models. The results regarding phenology aim to propose the setting up of comparable records at a regional (PannEx area) and global scale. This review will help to develop new climate projections in Romania in the climate change context through the project Agroclim.
Recycling Technology Innovation as a Source of Competitive Advantage: The Sustainable and Circular Business Model of a Bicentennial Company
Authors: Corral-Marfil José-Antonio , Arimany-Serrat Núria , Hitchen Emma L. , Viladecans-Riera Carme
Published: July 2021

La Farga Yourcoppersolutions is a bicentennial Catalan company that manufactures semi-finished copper products. As copper is a 100% recyclable material, much of the sector’s production comes from secondary copper, scrap, not from mined copper. In the case of La Farga, not only a good part of its output comes from recycled copper, but it is also a world leader in copper-recycling technology. The objective of the paper is to describe La Farga’s business model from the point of view of sustainability and the circular economy. What have been the causes and effects of recycling on the business model? Regarding the methodology, the work follows the research strategy of the case study. Both qualitative and quantitative data were collected from a variety of primary and secondary sources. Economic, social and environmental sustainability of the firm was assessed through financial and non-financial indicators; value-added generation and distribution were calculated from accounting data; and the circular business model was analysed via a thematic analysis: its components, innovation, enablers and barriers. Results show that the presence of barriers forces the implementation of circularity to be gradual and to combine linear and circular models to maintain competitiveness.
Landscape Governance and Sustainable Land Restoration: Evidence from Shinyanga, Tanzania
Authors: Nzyoka Judith , Minang Peter A. , Wainaina Priscilla , Duguma Lalisa , Manda Lucas , Temu Emmanuel
Published: July 2021

Inclusive land restoration is increasingly considered to be a critical sustainable pathway to the achievement of sustainable development goals (SDGs) in developing countries. The literature suggests that good governance practices support successful sustainable natural resource management. The study assesses the role of landscape governance in a long-term thriving forest and landscape restoration project in Shinyanga. We apply the good governance principles, which include participation, representation and legitimacy, actor interactors, equity and fairness, accountability and transparency, and respect for local knowledge. Descriptive methods are used to analyze the data collected through focus group discussions and key informant interviews. The evidence suggests that all of the principles contributed positively to the successful restoration, except for accountability and transparency. Building on local knowledge and institutions, the local rules and norms of restoration constituted the foundation of the success. Equity and empowerment were the least influential attributes due to the exclusion of women in the management of the restoration areas. The actors identified the enhancement of the incentives, equitable benefit-sharing mechanisms, performance, and accountability instruments as the key governance aspects that would benefit land restoration at the landscape level. Furthermore, cohesion and synergies amongst the different actors, the governing structures, and recognizing formal and informal institutions’ interactions are vital determinants of restoration outcomes.