bluuebunny/crossref_metadata_2025 huggingface dataset:
Non-Linear Chaotic Features-Based Human Activity Recognition
Authors: Tu Pengjia , Li Junhuai , Wang Huaijun , Cao Ting , Wang Kan
Published: January 2021

Human activity recognition (HAR) has vital applications in human–computer interaction, somatosensory games, and motion monitoring, etc. On the basis of the human motion accelerate sensor data, through a nonlinear analysis of the human motion time series, a novel method for HAR that is based on non-linear chaotic features is proposed in this paper. First, the C-C method and G-P algorithm are used to, respectively, compute the optimal delay time and embedding dimension. Additionally, a Reconstructed Phase Space (RPS) is formed while using time-delay embedding for the human accelerometer motion sensor data. Subsequently, a two-dimensional chaotic feature matrix is constructed, where the chaotic feature is composed of the correlation dimension and largest Lyapunov exponent (LLE) of attractor trajectory in the RPS. Next, the classification algorithms are used in order to classify and recognize the two different activity classes, i.e., basic and transitional activities. The experimental results show that the chaotic feature has a higher accuracy than traditional time and frequency domain features.
Representation Learning for Motor Imagery Recognition with Deep Neural Network
Authors: Xu Fangzhou , Rong Fenqi , Miao Yunjing , Sun Yanan , Dong Gege , Li Han , Li Jincheng , Wang Yuandong , Leng Jiancai
Published: January 2021

This study describes a method for classifying electrocorticograms (ECoGs) based on motor imagery (MI) on the brain–computer interface (BCI) system. This method is different from the traditional feature extraction and classification method. In this paper, the proposed method employs the deep learning algorithm for extracting features and the traditional algorithm for classification. Specifically, we mainly use the convolution neural network (CNN) to extract the features from the training data and then classify those features by combing with the gradient boosting (GB) algorithm. The comprehensive study with CNN and GB algorithms will profoundly help us to obtain more feature information from brain activities, enabling us to obtain the classification results from human body actions. The performance of the proposed framework has been evaluated on the dataset I of BCI Competition III. Furthermore, the combination of deep learning and traditional algorithms provides some ideas for future research with the BCI systems.
An Effective Data Sharing Scheme Based on Blockchain in Vehicular Social Networks
Authors: Jiang Yanji , Shen Xueli , Zheng Sifa
Published: January 2021

Vehicular social networks (VSNs) are the vehicular ad hoc networks (VANETs) that integrate social networks. Compared with traditional VANETs, VSNs are more suitable to serve a group of vehicles with common interests. In VSNs, vehicles can upload the necessary data in the cloud service provider (CSP) and other vehicles can query the data they are interested in through CSP, which enables VSNs to provide more user-friendly services. However, due to the wireless network communication environment, the data sent by the vehicle can easily be monitored. Adversaries are able to violate the privacy of the vehicle based on the collected data, thereby threatening the security of the entire network. In addition, if a vehicle shares malicious or false data with other vehicles, it is easy to mislead drivers and even cause serious traffic accidents. This paper proposes an effective data sharing scheme based on blockchain in VSNs. By integrating an identity based signature mechanism and pseudonym generation mechanism, we first propose an anonymous authentication mechanism as the basis for establishing trust relationships before data transmission between entities in VSNs. Then, a data sharing scheme based on blockchain is described, in which the signature mechanism and the consensus mechanism guarantee the security and traceability of data. The result of the performance analysis and the simulation experiment indicate that VAB can achieve a favourable performance compared with existing schemes.
Investigation of Structural and Optoelectronic Properties of Organic Semiconductor Film Based on 8-Hydroxyquinoline Zinc
Authors: Sánchez Vergara María Elena , Ramírez Vargas Lorena , Rios Citlalli , Molina Bertha , Salcedo Roberto
Published: January 2021

In this work, we investigated an organic semiconductor based on zinc 8-hydroxyquinoline (ZnQ2) and tetracyanoquinodimethane (TCNQ), which can be used as a photoactive layer in organic devices. The semiconductor was optimized by applying density-functional theory (DFT) methods, and four hydrogen bridges were formed between ZnQ2 and TCNQ. Later, thin films of ZnQ2-TCNQ were successfully deposited. The films were structurally and morphologically characterized, and the optical characteristics of the photoactive layer were investigated using ultraviolet–visible spectroscopy and time-dependent density-functional theory (TDDFT) calculations. The comparison and analysis of the experimental and theoretical absorption spectra indicate that the optical bandgap of the photoactive layer is 2.4 eV. Additionally, a flexible photo device was manufactured with the active layer ZnQ2-TCNQ, and its electrical behavior was evaluated under dark and light conditions. The results show a significant change in the behavior of the device when radiation is eliminated; the layer is light sensitive. The electrical resistance in the flexible photo device is associated with the optical behavior of the materials that constitute the active layer.
A Horn Antenna Covered with a 3D-Printed Metasurface for Gain Enhancement
Authors: Shrestha Sujan , Baba Affan A. , Abbas Syed Muzahir , Asadnia Mohsen , Hashmi Raheel M.
Published: January 2021

A simple metasurface integrated with horn antenna exhibiting wide bandwidth, covering full Ku-band using 3D printing is presented. It consists of a 3D-printed horn and a 3D-printed phase transformation surface placed at the horn aperture. Considering the non-uniform wavefront of 3D printed horn, the proposed 3D-printed phase transformation surface is configured by unit cells, consisting of a cube in the centre which is supported by perpendicular cylindrical rods from its sides. Placement of proposed surface helps to improve the field over the horn aperture, resulting in lower phase variations. Both simulated and measured results show good radiation characteristics with lower side lobe levels in both E- and H-planes. Additionally, there is an overall increment in directivity with peak measured directivity up to 24.8 dBi and improvement in aperture efficiency of about 35% to 72% in the frequency range from 10–18 GHz. The total weight of the proposed antenna is about 345.37 g, which is significantly light weight. Moreover, it is a low cost and raid manufacturing solution using 3D printing technology.
Modeling of PV Module and DC/DC Converter Assembly for the Analysis of Induced Transient Response Due to Nearby Lightning Strike
Authors: Formisano Alessandro , Hernández Jesus C. , Petrarca Carlo , Sanchez-Sutil Francisco
Published: January 2021

Photovoltaic (PV) systems are subject to nearby lightning strikes that can contribute to extremely high induced overvoltage transients. Recently, the authors introduced a 3D semi-analytical method to study the electromagnetic transients caused by these strikes in a PV module. In the present paper we develop an improved model of the PV module that: (a) takes into account high-frequency effects by modelling capacitive and inductive couplings; (b) considers the electrical insulation characteristics of the module; (c) includes the connection to a DC/DC converter. The whole process involves three major steps, i.e., the magnetic-field computation, the evaluation of both common-mode- and differential-mode-induced voltages across the PV module, and the use of the calculated voltages as input to a lumped equivalent circuit of the PV module connected to the DC/DC converter. In such a framework, the influence of the PV operating condition on the resulting electrical stresses is assessed; moreover, the relevance or insignificance of some parameters, such as the module insulation or the frame material, is demonstrated. Finally, results show that the induced overvoltage are highly dependent both on the grounding of the conducting parts and on the external conditions such as lightning current waveforms and lightning channel (LC) geometry.
Secure Autonomous Cloud Brained Humanoid Robot Assisting Rescuers in Hazardous Environments
Authors: Angelopoulos Georgios , Baras Nikolaos , Dasygenis Minas
Published: January 2021

On 31 January 2020, the World Health Organization (WHO) declared a global emergency after the discovery of a new pandemic disease that caused severe lung problems. The spread of the disease at an international level drew the attention of many researchers who attempted to find solutions to ameliorate the problem. The implementation of robotics has been one of the proposed solutions, as automated humanoid robots can be used in many situations and limit the exposure of humans to the disease. Many humanoid robot implementations are found in the literature; however, most of them have some distinct drawbacks, such as a high cost and complexity. Our research proposes a novel, secure and efficient programmable system using a humanoid robot that is able to autonomously move and detect survivors in emergency scenarios, with the potential to communicate verbally with victims. The proposed humanoid robot is powered by the cloud and benefits from the powerful storage, computation, and communication resources of a typical modern data center. In order to evaluate the proposed system, we conducted multiple experiments in synthetic hazardous environments.
Numerical Simulation of Pulsed Gravel Packing Completion in Horizontal Wells
Authors: Zhang Zhenxiang , Yang Jin , Chen Shengnan , Ou Qibin , Zhang Yichi , Qu Ximo , Guo Yafei
Published: January 2021

The gravel packing completion method for horizontal wells has the advantages of maintaining high oil production for a long time, maintaining wellbore stability, and preventing sand production, so it has become the preferred completion method for horizontal wells. At present, this technology still faces the problems of high sand bed height and poor gravel migration. In order to improve the efficiency of gravel packing in horizontal wells, pulsed gravel packing technology for horizontal wells is proposed for the first time. Based on the mechanism of hydraulic pulse, the Eulerian–Eulerian model, k-ε model based on the renormalization group theory (RNG k-ε model), and Fluent are used to simulate the solid-liquid two-phase flow. By optimizing the parameters such as frequency and amplitude of pulse waveform, the optimal pulse waveform of pulsed gravel packing in horizontal wells is determined. The effects of parameters such as sand-carrying fluid displacement, sand-carrying fluid viscosity, sand-carrying ratio, gravel particle size, and string eccentricity on pulsed gravel packing in horizontal wells are studied, and the distribution law of gravel migration velocity and volume fraction in horizontal wells is obtained. According to the results, it can be seen that with the increase of displacement and viscosity of carrier fluid, the volume fraction of fixed bed and moving bed decreases gradually, while that of suspension bed increases gradually. With the increase of sand-carrying ratio, gravel particle size, and string eccentricity, the volume fraction of fixed bed and moving bed increases gradually, while that of suspended bed decreases gradually. Comparing the effects of conventional gravel packing and pulsed gravel packing in horizontal wells, it can be concluded that the efficiency of pulsed gravel packing in horizontal wells is higher. The volume fraction of fixed bed and moving bed decreased by 30% and 40% respectively, while the volume fraction of suspended bed increased by 20%. The migration velocity of moving bed and suspended bed increased by 40% and 25%, respectively, and the migration ability of gravel improved obviously.
Internal Wind Turbine Blade Inspections Using UAVs: Analysis and Design Issues
Authors: Kulsinskas Andrius , Durdevic Petar , Ortiz-Arroyo Daniel
Published: January 2021

Interior and exterior wind turbine blade inspections are necessary to extend the lifetime of wind turbine generators. The use of unmanned vehicles is an alternative to exterior wind turbine blade inspections performed by technicians that require the use of cranes and ropes. Interior wind turbine blade inspections are even more challenging due to the confined spaces, lack of illumination, and the presence of potentially harmful internal structural components. Additionally, the cost of manned interior wind turbine blade inspections is a major limiting factor. This paper analyses all aspects of the viability of using manually controlled or autonomous aerial vehicles for interior wind turbine blade inspections. We discuss why the size, weight, and flight time of a vehicle, in addition to the structure of the wind turbine blade, are the main limiting factors in performing internal blade inspections. We also describe the design issues that must be considered to provide autonomy to unmanned vehicles and the control system, the sensors that can be used, and introduce some of the algorithms for localization, obstacle avoidance and path planning that are best suited for the task. Lastly, we briefly describe which non-destructive test instrumentation can be used for the purpose.
Innovative Solutions to Use Ground-Coupled Heat Pumps in Historical Buildings: A Test Case in the City of Napoli, Southern Italy
Authors: Massarotti Nicola , Mauro Alessandro , Normino Gennaro , Vanoli Laura , Verde Clara , Allocca Vincenzo , Calcaterra Domenico , Coda Silvio , De Vita Pantaleone , Forzano Cesare , Palombo Adolfo , Cosenza Paolo
Published: January 2021

The new standards on energy saving for new and existing buildings have animated both researchers and technicians in recent years, aiming at reducing the dependence on fossil fuels, improving indoor comfort, and systems efficiency. In this scenario, special attention must be paid to historical buildings that need to preserve their key testimonial heritage within the society. This paper describes the design and realization stages of a pilot system based on a ground-coupled heat pump, operating both in heating and cooling modes, installed in the monumental site of Saints Marcellino and Festo (SM&F), in Naples, Southern Italy. This study aims to demonstrate that low-enthalpy geothermal systems can be employed as energy retrofit applications in buildings of historical, artistic, and cultural interest and, at the same time, to prove that the use of this technology allows achieving the objectives, set at global level by the current regulations, and requiring a reduction of carbon dioxide emissions (tCO2) of 53% compared to technology using fossil fuels.
Integrated Offshore Seismic Survey Using an Unmanned Wave Glider
Authors: Cheong Snons , Kim Young-Jun , Chun Jong-Hwa , Kim Jung-Ki , Huh Shin
Published: January 2021

An autonomous surface vehicle, known as a wave glider, was used to record refracted and reflected signals from a seismic source penetrating the shallow subsurface. An integrated survey system consisting of a wave gilder and a human-operated source vessel was deployed. These survey systems are used to acquire wide-offset seismic survey data from specific areas, such as offshore structures. The wave gliders can collect seismic refraction and reflection data, which can be used to estimate subsurface information, e.g., acoustic wave velocity and subsurface structure. We processed raw data collected by a receiver equipped with the wave glider and used the relationship between travel time and offset distance to calculate the velocities of shallow sedimentary deposits and the acoustic basement. The velocities of the sedimentary deposits and basement were estimated to be 1557 and 3507 m/s, respectively. We then overlaid the velocities on subsurface data measured using a single-channel streamer. Our results indicate that unmanned equipment can be used for ocean exploration to aid offshore energy development.
Performance Evaluation of a Photovoltaic Thermal (PVT) System Using Nanofluids
Authors: Mahmood Alsalame Haedr Abdalha , Lee Joo Hee , Lee Gwi Hyun
Published: January 2021

In this study, a performance evaluation of a photovoltaic thermal (PVT) system using nanofluids was carried out through an efficiency comparison study using water, CuO-water, and Al2O3-water nanofluids as the heat medium of the PVT system. In addition, a model for computational fluid dynamics (CFD) analysis was established, and the validity of the model was verified by comparing it with the experimental results of the PVT system. Through this, it was confirmed that the outlet temperature of the PVT system using nanofluids can be predicted by applying various conditions. Based on the results, the use of nanofluid as heating medium for the PVT system is proposed to improve the efficiency sufficiently compared to the conventional heating media.
Robust Scheduling for Pumping in a Water Distribution System under the Uncertainty of Activating Regulation Reserves
Authors: Negishi Shintaro , Ikegami Takashi
Published: January 2021

A new robust scheduling method for pumping water in a water distribution system under the uncertainty of activating regulation reserves is proposed in this paper. During the operation of power systems, utilizing the energy equipment of the customer to enhance supply-demand control is attracting attention. Because water pumps have been already installed, they can be regarded as a relatively inexpensive, operational, and flexible resource. Changes in the operation of the water pump can contribute to the power supply and demand control. The proposed method helps generate a robust daily schedule for pumping water and provides regulation reserves under the uncertainty of activating regulation reserves. It is based on electric energy prices and regulation reserves, hourly water demand profiles, and the properties of water flow quantity and the electricity consumption of water pumps. This method comprises an optimization model formulated using mixed integer linear programming, validated through simulations of water pumping scheduling under certain scenarios. The results indicate that the net operational cost decreased when water pumps provided regulation reserves; further, the operational feasibility of providing these reserves from water pumps is clarified. The proposed model makes it possible to optimize power system operation that integrates the water supply system.
Intelligent Starting Current-Based Fault Identification of an Induction Motor Operating under Various Power Quality Issues
Authors: Ganesan Sakthivel , David Prince Winston , Balachandran Praveen Kumar , Samithas Devakirubakaran
Published: January 2021

Since most of our industries use induction motors, it is essential to develop condition monitoring systems. Nowadays, industries have power quality issues such as sag, swell, harmonics, and transients. Thus, a condition monitoring system should have the ability to detect various faults, even in the presence of power quality issues. Most of the fault diagnosis and condition monitoring methods proposed earlier misidentified the faults and caused the condition monitoring system to fail because of misclassification due to power quality. The proposed method uses power quality data along with starting current data to identify the broken rotor bar and bearing fault in induction motors. The discrete wavelet transform (DWT) is used to decompose the current waveform, and then different features such as mean, standard deviation, entropy, and norm are calculated. The neural network (NN) classifier is used for classifying the faults and for analyzing the classification accuracy for various cases. The classification accuracy is 96.7% while considering power quality issues, whereas in a typical case, it is 93.3%. The proposed methodology is suitable for hardware implementation, which merges mean, standard deviation, entropy, and norm with the consideration of power quality issues, and the trained NN proves stable in the detection of the rotor and bearing faults.
Thermodynamic Efficiency Maximum of Simple Organic Rankine Cycles
Authors: Ahmed Aram Mohammed , Kondor László , Imre Attila R.
Published: January 2021

The increase of the maximal cycle temperature is considered as one of the best tools to increase cycle efficiency for all thermodynamic cycles, including Organic Rankine Cycles (ORC). Technically, this can be done in various ways, but probably the best solution is the use of hybrid systems, i.e., using an added high-temperature heat source to the existing low-temperature heat source. Obviously, this kind of improvement has technical difficulties and added costs; therefore, the increase of efficiency by increasing the maximal temperature sometimes has technical and/or financial limits. In this paper, we would like to show that for an ideal, simple-layout ORC system, a thermodynamic efficiency-maximum can also exist. It means that for several working fluids, the thermodynamic efficiency vs. maximal cycle temperature function has a maximum, located in the sub-critical temperature range. A proof will be given by comparing ORC efficiencies with TFC (Trilateral Flash Cycle) efficiencies; for wet working fluids, further theoretical evidence can be given. The group of working fluids with this kind of maximum will be defined. Generalization for normal (steam) Rankine cycles and CO2 subcritical Rankine cycles will also be shown. Based on these results, one can conclude that the increase of the maximal cycle temperature is not always a useful tool for efficiency-increase; this result can be especially important for hybrid systems.
Construction of a Frequency Compliant Unit Commitment Framework Using an Ensemble Learning Technique
Authors: Chiu Hsin-Wei , Chang-Chien Le-Ren , Wu Chin-Chung
Published: January 2021

Frequency control is essential to ensure reliability and quality of power systems. North American Electric Reliability Corporation’s (NERC) Control Performance Standard 1 (CPS1) is widely adopted by many operating authorities to examine the quality of the frequency control. The operating authority would have a strong interest in knowing how the frequency-sensitive features affect the CPS1 score and finding out more effective unit-dispatch schedules for reaching the CPS1 goal. As frequency-sensitive features usually possess multi-variable and high-correlated characteristics, this paper employed an ensemble learning technique (the Gradient Boosting Decision Tree algorithm, GBDT) to construct Frequency Response Model (FRM) of the Taipower system in Taiwan to evaluate by CPS1 score. The proposed CPS1 model was then integrated with Unit Commitment (UC) program to determine the unit-dispatch that achieves the targeted CPS1 score. The feasibility and effectiveness of the proposed CPS1-UC platform were validated and compared with the other benchmark model-based UC methods by two operating cases. The proposed model shows promising results: the system frequency could be maintained well, especially in the periods of the early morning or the high renewable penetration.
The Impact of Renewable Energy, Economic and Population Growth on CO2 Emissions in the East African Region: Evidence from Common Correlated Effect Means Group and Asymmetric Analysis
Authors: Namahoro Jean Pierre , Wu Qiaosheng , Xiao Haijun , Zhou Na
Published: January 2021

This study aims to examine the asymmetric nexus between CO2 emissions and renewable energy and economic and population growth in seven East African countries (EACs) at the regional level and country levels. Common correlated effect means group (CCEMG), nonlinear autoregressive distributed lagged (NARDL), and causality tests were employed for the panel data from 1980 to 2016. The main findings are as follows: (1) Renewable energy consumption negatively affects CO2 emissions, while economic and population growth positively affect CO2 emissions at the regional level. (2) The findings of asymmetric and symmetric linkages between CO2 emissions and its determinants (economic and population growth and renewable energy) are very volatile across the country levels. (3) The causality hypotheses are different across the country and regional levels. (4) This study shows the renewable energy growth nexus, wherein renewable energy positively affects economic growth at the regional level. Lastly, the study suggests potential policy implications for effectively reducing CO2 emissions as well as growing the economy at the regional level.
Determining the Power Consumption of the Automatic Device for Belt Perforation Based on the Dynamic Model
Authors: Wojtkowiak Dominik , Talaśka Krzysztof , Wilczyński Dominik , Górecki Jan , Wałęsa Krzysztof
Published: January 2021

The subject of the dynamic analysis presented in the article is the linear drive system with a timing belt utilized in the automatic device for polymer composite belt perforation. The analysis was carried out in two stages. In the first stage, the timing belt was modeled with all the relevant dynamic phenomena; subsequently, the tension force of the belt required for the correct operation of the belt transmission was determined. The necessary parameters for belt elasticity, vibration damping, and inertia are based exclusively on the catalog data provided by the manufacturer. During the second stage, equations of motion were derived for the designed drive system with a timing belt, and characteristics were identified to facilitate the optimal selection of electromechanical drives for the construction solution under analysis. The presented methodology allows for designing an effective solution that may be adapted for other constructions. The obtained results showed the influence of the kinematic parameters on the motor torque and proved the importance of reducing the mass of the components in machines that perform high-speed processes.
Determinants of Energy Cooperatives’ Development in Rural Areas—Evidence from Poland
Authors: Jasiński Jakub , Kozakiewicz Mariusz , Sołtysik Maciej
Published: January 2021

The strategies, plans and legislation on energy market development and decarbonization in the European Union (EU) developed in recent years, such as the directives implementing the package “Clean energy for all Europeans”, aim at promoting not only renewable energy sources, but also new institutions that involve the development of local energy markets and a greater role for citizens in managing their own energy generation. At the same time, Poland remains the economy most dependent on coal and one of the largest air polluters in the EU. In order to minimize this problem and to meet the direction of energy development in the EU, Poland decided to establish, among other things, an energy cooperative. It is intended to fill the gap in the development of the civil dimension of energy on a local scale and at the same time improve efficiency in the use of the potential of renewable energy sources in rural areas. The authors of the paper seek to verify the extent to which this new institution, which is part of the idea of a local energy community, one of the driving forces for the implementation of the objectives and directions of development of “clean energy” set by the EU, has a chance to develop. The research took into account the characteristics of energy producers and consumers in rural areas, economic preferences provided for by law, relating to the functioning of an energy cooperative and the existing alternative solutions dedicated to prosumers. A dedicated mathematical model in the mixed integer programming technology was used to optimize the functioning of an energy cooperative, and more than 5000 simulations were carried out, with a typical optimization task performed as part of the research with about 50,000 variables. The conclusions and simulations make it possible to confirm the thesis that profitable energy cooperatives can be established in rural areas, with the objective of minimizing the sum of energy purchases from the distribution network and losses on the energy deposit (virtual network storage) (the energy deposit (or network deposit) should be understood as energy introduced to the grid during generation surpluses for its subsequent consumption, taking into account the discount factor).
Lightning Overvoltage Protection of Step-Up Transformer Inside a Nacelle of Onshore New-Generation Wind Turbines
Authors: Sarajcev Petar , Meglic Antun , Goic Ranko
Published: January 2021

This paper presents an electromagnetic transient analysis of lightning-initiated overvoltage stresses of the step-up transformers installed inside a nacelle of onshore, multi-megawatt, new-generation wind turbines. The increase in the wind turbine (WT) nominal power output, necessitated introducing the step-up transformer into the nacelle. A transformer installed inside a nacelle is subjected to completely different overvoltage stresses from those present if it were installed at the base of the WT tower. This has serious repercussions on its overvoltage protection (i.e., selection and installation of surge arresters) and insulation coordination. Furthermore, the overvoltage protection of medium-voltage cables (inside the tower) is also problematic when considering their length, proximity to the tower wall, and their screen grounding practices, and needs to be tackled in conjunction with that of the step-up transformer. This paper presents detailed models for the various components of the latest-generation WTs, intended for fast-front transient analysis and assembled within the EMTP software package. We further present the comprehensive results of the lightning-transient numerical simulations, covering both upward and downward (first and subsequent) strikes, their analysis, and recommendations for the optimal selection of medium-voltage surge arresters for the step-up transformers installed inside a nacelle.
Assessment of Above-Ground Carbon Storage by Urban Trees Using LiDAR Data: The Case of a University Campus
Authors: Gülçin Derya , van den Bosch Cecil C. Konijnendijk
Published: January 2021

The biomass represented by urban trees is important for urban decision-makers, green space planners, and managers seeking to optimize urban ecosystem services. Carbon storage by urban trees is one of these services. Suitable methods for assessing carbon storage by urban trees are being explored. The latest technologies in remote sensing and data analyses can reduce data collection costs while improving accuracy. This paper introduces an assessment approach that combines ground measurements with unmanned aerial vehicle-based light detection and ranging (LiDAR) data to estimate carbon storage by urban trees. Methods underpinning the approach were tested for the case of the Vancouver campus of the University of British Columbia (UBC), Canada. The study objectives were (1) to test five automated individual tree detection (AITD) algorithms and select one on the basis of the highest segmentation accuracy, (2) to develop a model to estimate the diameter at breast height (DBH), and (3) to estimate and map carbon storage over the UBC campus using LiDAR heights, estimated DBHs, and an existing tree-level above-ground carbon estimation model. Of the segmentation algorithms tested, the Dalponte AITD had the highest F score of 0.83. Of the five CW thresholds (th) tested in the DBH estimation model, we chose one resulting in the lowest Akaike’s information criterion, the highest log-likelihood, and the lowest root-mean-squared error (19.55 cm). Above-ground carbon was estimated for each tree in the study area and subsequently summarized, resulting in an estimated 5.27 kg C·m−2 over the main campus of UBC, Vancouver. The approach could be used in other urban jurisdictions to obtain essential information on urban carbon storage in support of urban landscape governance, planning, and management.
Cupressaceae Pollen in the City of Évora, South of Portugal: Disruption of the Pollen during Air Transport Facilitates Allergen Exposure
Authors: Galveias Ana , Costa Ana R. , Bortoli Daniele , Alpizar-Jara Russell , Salgado Rui , Costa Maria João , Antunes Célia M.
Published: January 2021

Research Highlights: Daily airborne Cupressaceae pollen disruption ranged from 20 to 90%; relative humidity (RH), rainfall and atmospheric pressure (AtP) were the major meteorological determinants of this phenomenon. Background and Objectives: Cupressaceae family includes several species that are widely used as ornamental plants pollinating in late winter-early spring and might be responsible for allergic outbreaks. Cupressaceae pollen disruption may favour allergen dissemination, potentiating its allergenicity. The aim of this work was to characterize the Cupressaceae pollen aerobiology in Évora, South of Portugal, in 2017 and 2018, particularly the pollen disruption, and to identify the meteorological parameters contributing to this phenomenon. Materials and Methods: Pollen was collected using a Hirst type 7-day pollen trap and was identified following the standard methodology. Temperature, RH, rainfall, global solar radiation (Global Srad), AtP, wind speed and direction were obtained from a weather station installed side-by-side to the Hirst platform. Back trajectories (12-h) of air masses arriving at Évora were calculated using the HYSPLIT model. Results: Cupressaceae pollen index was higher in 2017 compared to 2018 (>5994 and 3175 pollen/m3, respectively) and 36 ± 19% (2017) and 64 ± 17% (2018) of the pollen was disrupted. Higher levels of disrupted pollen coincided with RH > 60% and rainfall. Temperature, Global Srad and AtP correlated negatively with pollen disruption. Wind speed and wind direction did not significantly correlate with pollen disruption. Intra-diurnal pollen pattern peaked between 9:00 am–2:00 pm, suggesting local origin, confirmed by the back trajectory analysis. Intra-diurnal pollen disruption profile followed hourly pollen pattern and it negatively correlated with AtP, temperature and Global Srad but was uncorrelated with RH. Conclusions: The results suggest that RH, rainfall and AtP are the main factors affecting airborne Cupressaceae pollen integrity and in conjunction with daily pollen concentration may be used to predict the risk of allergy outbreaks to this pollen type.
The Significance of Exosomal RNAs in the Development, Diagnosis, and Treatment of Gastric Cancer
Authors: Zhao Guiping , Zhou Anni , Li Xiao , Zhu Shengtao , Wang Yongjun , Zhang Shutian , Li Peng
Published: January 2021

Gastric cancer (GC) is one of the most common malignancies in the world. Exosomes, a subset of extracellular vesicles with an average diameter of 100 nm, contain and transfer a variety of functional macromolecules such as proteins, lipids, and nucleic acids. A large number of studies indicated that exosomes can play a significant role in the initiation and development of GC via facilitating intercellular communication between gastric cancer cells and microenvironment. Exosomal RNAs, one of the key functional cargos, are involved in the pathogenesis, development, and metastasis of GC. In addition, recent studies elucidated that exosomal RNAs may serve as diagnostic and prognostic biomarkers or therapeutic targets for GC. In this review, we summarized the function of exosomal RNA in the tumorigenesis, progression, diagnosis, and treatment of GC, which may further unveil the functions of exosome and promote the potentially diagnostic and therapeutic application of exosomes in GC.
Effect of ACTN3 R577X Genotype on Injury Epidemiology in Elite Endurance Runners
Authors: Gutiérrez-Hellín Jorge , Baltazar-Martins Gabriel , Aguilar-Navarro Millán , Ruiz-Moreno Carlos , Oliván Jesús , Del Coso Juan
Published: January 2021

The p.R577X polymorphism (rs1815739) in the ACTN3 gene causes individuals with the ACTN3 XX genotype to be deficient in functional α-actinin-3. Previous investigations have found that XX athletes are more prone to suffer non-contact muscle injuries. This investigation aimed to determine the influence of the ACTN3 R577X polymorphism in the injury epidemiology of elite endurance athletes. Using a cross-sectional experiment, the epidemiology of running-related injuries was recorded for one season in a group of 89 Spanish elite endurance runners. ACTN3 R577X genotype was obtained for each athlete using genomic DNA samples. From the study sample, 42.7% of athletes had the RR genotype, 39.3% had the RX genotype, and 18.0% had the XX genotype. A total of 96 injuries were recorded in 57 athletes. Injury incidence was higher in RR runners (3.2 injuries/1000 h of running) than in RX (2.0 injuries/1000 h) and XX (2.2 injuries/1000 h; p = 0.030) runners. RR runners had a higher proportion of injuries located in the Achilles tendon, RX runners had a higher proportion of injuries located in the knee, and XX runners had a higher proportion of injuries located in the groin (p = 0.025). The ACTN3 genotype did not affect the mode of onset, the severity, or the type of injury. The ACTN3 genotype slightly affected the injury epidemiology of elite endurance athletes with a higher injury rate in RR athletes and differences in injury location. However, elite ACTN3 XX endurance runners were not more prone to muscle-type injuries.
Geochemical and Mineralogical Characterization of Construction Materials from Historical Buildings of Ferrara (Italy)
Authors: Marrocchino Elena , Telloli Chiara , Vaccaro Carmela
Published: January 2021

This paper presents a chemical-mineralogical characterization of construction materials from medieval Renaissance buildings of Ferrara (NE Italy) to provide an insight into the nature and provenance of the raw materials used. Biagio Rossetti was an Italian architect and urbanist from the city of Ferrara. From 1483, he was the architect of the Duke of Ferrara Ercole I d’Este who in 1492 assigned him the project of enlarging the city of Ferrara. Biagio Rossetti is still famous because he designed and built many notable palaces and churches in Ferrara, e.g., the Palazzo Roverella, the monastery of Santa Maria delle Grazie and the renovation of the church of San Andrea. To date, only the first two historic buildings are still in use and consequently restored, while the church of San Andrea has been abandoned over the years and the remains have been subject to decay. Different kinds of samples (bricks, cotto, plaster and mortars) were collected from the three sampling sites and analyzed in X-ray fluorescence and X-ray diffractometer to investigate the construction materials through the evaluation of their chemical composition, historic building activity and degradation degree. These investigations should provide knowledge useful for restoration and conservation processes.
Menstrual Cycle Patterns and the Prevalence of Premenstrual Syndrome and Polycystic Ovary Syndrome in Korean Young Adult Women
Authors: Park Young-Joo , Shin Hyunjeong , Jeon Songi , Cho Inhae , Kim Yae-Ji
Published: January 2021

Menstruation is one of the important indicators of reproductive health. Therefore, in order to improve the reproductive health of women in puberty and early adulthood, it is necessary to investigate menstrual health and symptoms. This cross-sectional descriptive correlational study was conducted to identify young women’s menstrual cycle patterns, prevalence of Premenstrual Syndrome (PMS), Polycystic Ovary Syndrome (PCOS) and the relationships of health-related factors according to menstrual regularity and PCOS. 462 women participated in the first phase of the study and completed the menstrual health and health-related behaviors questionnaire. In the second phase, 88 women with irregular menstruation in phase one had blood tests taken and body composition measured. As a result, Menarche was slightly later in irregular menstruation group. Women with regular menstruation had a mean number of 11.7 menstrual cycles over the past year, 93.0% of them reported a normal menstruation cycle frequency (21–35 days), 95.2% reported a normal duration (2–7 days) and 55.9% of participants had heavy menstrual bleeding. In the irregular menstrual group, there were higher percentages of underweight and obese women as well as more women experiences weight and diet changes. The estimated prevalence rates of PMS and PCOS were 25.5%, 5.2% respectively. This study provides updated basic data about menstrual health among Korean young women but more extensive and sophisticated studies are needed in the future.
The Role of the mHealth in the Fight against the Covid-19: Successes and Failures
Authors: Giansanti Daniele
Published: January 2021

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Family Variables and Quality of Life in Children with Down Syndrome: A Scoping Review
Authors: Lee Anna , Knafl Kathleen , Van Riper Marcia
Published: January 2021

The purpose of this scoping review was to identify the family and child quality of life variables that have been studied in relation to one another in children with Down syndrome, the frequency with which different relationships have been studied, and the extent to which family variables were the focus of the research aims. A literature search was conducted to find studies published between January 2007 and June 2018. The initial search yielded 2314 studies; of these, 43 were selected for a final review. Researchers most often addressed family resources and family problem-solving and coping concerning child personal development and physical well-being. Little attention to child emotional well-being was observed, with none considering family appraisal of child emotional well-being. The relationship between family variables and child QoL rarely was the primary focus of the study. Methodologically, most reviewed studies used cross-sectional designs, were conducted in North America and based on maternal report. From future research considering the issues found in this review, healthcare providers can obtain an in-depth understanding of relationships between children and family variables.
The Perceived Restorativeness of Differently Managed Forests and Its Association with Forest Qualities and Individual Variables: A Field Experiment
Authors: Simkin Jenni , Ojala Ann , Tyrväinen Liisa
Published: January 2021

Despite increasing research knowledge about the positive well-being effects forests have on citizens, it is still unclear how the quality of forests and individual variables effect the well-being. This research investigated (1) the differences in restorative experiences (components being away, fascination, compatibility and extent, measured by perceived restorativeness (PRS)), and (2) how people evaluate forest qualities in four differently managed forests. Furthermore, this research studied (3) which individual variables (4) as well as forest qualities, explain the overall restorative experience (PRS-score from all components). Altogether, 66 volunteers were taken in small groups to each of the four forest sites once, after their day at work. The participants viewed the forests for 15 min and then walked inside the forests for 30 min. Their perceived restorativeness and perceptions about forest qualities were measured on-site after each visit. Most of the components of PRS differed between the three older forests compared to the young forest. The three older forests also had more preferred qualities, compared to the young commercial forest. From the individual variables, the nature relatedness positively explained the restorative experiences (PRS-score) in old-growth forest and in mature commercial forest. Beauty was the most important quality that explained PRS-score in all forests. Biodiversity positively explained the PRS-score, except in urban recreation forest. However, not all forest qualities need to be present in order to reach high perceived restorativeness and both a pristine or managed old forest can have high restorative values. Also, decaying wood does not seem to diminish forests’ restorative values, but there may be individual differences in its acceptance. Therefore, a greater attention to the overall versatility is needed when managing the forest used for outdooring.
Translation and First Pilot Validation Study of the “Undergraduate Nursing Student Academic Satisfaction Scale” Questionnaire to the Spanish Context
Authors: Guerra-Martín María Dolores , Cano-Orihuela Alejandro , Martos-García Raúl , Ponce-Blandón José Antonio
Published: January 2021

Satisfaction helps nursing students to develop skills and improve their academic performance, hence the importance of assessing it by means of a reliable instrument. The objective was to translate and culturally adapt the “Undergraduate Nursing Student Academic Satisfaction Scale” (UNSASS) instrument to the Spanish context. A cross-sectional study was conducted with a representative sample of 354 fourth-year nursing students from University of Seville, Seville, Spain. The validation process was carried out in five phases as follows: direct translation, synthesis of the translations, back translation, consolidation by a panel of experts, and pilot test with nursing students. After two rounds among two expert committees, the Content Validity Index (CVI) varied from 0.85 to 1, obtaining a CVI above 0.8 with the global questionnaire. A scale composed of 48 items and 4 subscales was obtained, resulting in a Cronbach’s α coefficient of 0.96. Within the subscales, this coefficient varied between 0.92 and 0.94. No statistically significant differences were found between the total satisfaction of the scale and gender and teaching unit. An inversely proportional relationship was found between the age and the “Support & Resources” scale. The “Escala de Satisfacción Académica del Estudiante de Enfermería” (ESAEE) scale was obtained, translated, and adapted to the Spanish context from the UNSASS scale, with satisfactory consistency and validity.
A Rapid Assessment of Disaster Preparedness Needs and Resources during the COVID-19 Pandemic
Authors: Palinkas Lawrence A. , Springgate Benjamin F. , Sugarman Olivia K. , Hancock Jill , Wennerstrom Ashley , Haywood Catherine , Meyers Diana , Johnson Arthur , Polk Mara , Pesson Carter L. , Seay Jessica E. , Stallard Caroline N. , Wells Kenneth B.
Published: January 2021

Background: This year has seen the emergence of two major crises, a significant increase in the frequency and severity of hurricanes and the COVID-19 pandemic. However, little is known as to how each of these two events have impacted the other. A rapid qualitative assessment was conducted to determine the impact of the pandemic on preparedness and response to natural disasters and the impact of past experiences with natural disasters in responding to the pandemic. Methods: Semi-structured interviews were conducted with 26 representatives of 24 different community-based programs in southern Louisiana. Data were analyzed using procedures embedded in the Rapid Assessment Procedure-Informed Community Ethnography methodology, using techniques of immersion and crystallization and focused thematic analysis. Results: The pandemic has impacted the form and function of disaster preparedness, making it harder to plan for evacuations in the event of a hurricane. Specific concerns included being able to see people in person, providing food and other resources to residents who shelter in place, finding volunteers to assist in food distribution and other forms of disaster response, competing for funds to support disaster-related activities, developing new support infrastructures, and focusing on equity in disaster preparedness. However, several strengths based on disaster preparedness experience and capabilities were identified, including providing a framework for how to respond and adapt to COVID and integration of COVID response with their normal disaster preparedness activities. Conclusions: Although prior experience has enabled community-based organizations to respond to the pandemic, the pandemic is also creating new challenges to preparing for and responding to natural disasters.