bluuebunny/crossref_metadata_2025 huggingface dataset:
Layered Inter-Cluster Cooperation Scheme for Backhaul-Constrained C-RAN Uplink Systems in the Presence of Inter-Cluster Interference
Authors: Kim Junbeom , Park Seok-Hwan
Published: May 2020

Despite the potential benefits of reducing system costs and improving spectral efficiency, it is challenging to implement cloud radio access network (C-RAN) systems due to the performance degradation caused by finite-capacity fronthaul links and inter-cluster interference signals. This work studies inter-cluster cooperative reception for the uplink of a two-cluster C-RAN system, where two nearby clusters interfere with each other on the uplink access channel. The radio units (RUs) of two clusters forward quantized and compressed version of the uplink received signals to the serving baseband processing units (BBUs) via finite-capacity fronthaul links. The BBUs of the clusters exchange the received fronthaul signals via finite-capacity backhaul links with the purpose of mitigating inter-cluster interference signals. Optimization of conventional cooperation scheme, in which each RU produces a single quantized signal, requires an exhaustive discrete search of exponentially increasing search size with respect to the number of RUs. To resolve this issue, we propose an improved inter-BBU, or inter-cluster, cooperation strategy based on layered compression, where each RU produces two descriptions, of which only one description is forwarded to the neighboring BBU on the backhaul links. We discuss the optimization of the proposed inter-cluster cooperation scheme, and validate the performance gains of the proposed scheme via numerical results.
Opportunities and Challenges of Future District Heating Portfolios of an Austrian Utility
Authors: Büchele Richard , Kranzl Lukas , Hartner Michael , Hasani Jeton
Published: May 2020

In this paper, opportunities and challenges of concrete portfolio options of an Austrian district heating (DH) supplier are assessed against the background of current challenges of the DH sector. The following steps are performed: (1) analysis of status quo; (2) analysis of current and possible future economic framework conditions; (3) definition of four concrete future portfolio options for investment planning until the year 2030; (4) modeling of status quo and future portfolios together with the respective framework conditions in a linear dispatch optimization model; and (5) perform techno-economic analysis for each portfolio under the different possible future framework conditions. The expected increase in renewable power generation capacity is likely to increase volatility in future electricity prices with hours of both very low and very high prices. This higher volatility results in higher technical flexibility requirements for the heat generation plants and a need for heat generation portfolios to respond to both high and low electricity prices. The results indicate that the combination of heat pumps and combined heat and power (CHP) plants is well suited to cope with these challenges from a microeconomic point of view. At the same time, we show that a shift to a high share of renewables of more than 60%, implying a complete exit of gas fired CHPs, is also feasible with costs in a very similar range as the current DH generation portfolio.
Effects of Thickened Excess Sludge Pre-Treatment Using Hydrodynamic Cavitation for Anaerobic Digestion
Authors: Garlicka Agnieszka , Zubrowska-Sudol Monika , Umiejewska Katarzyna , Roubinek Otton , Palige Jacek , Chmielewski Andrzej
Published: May 2020

The main purpose of this study was the assessment of the possibility of increasing the production of biogas through the pre-treatment of thickened excess sludge (TES) by means of the hydrodynamic cavitation (HC) conducted at different levels of energy density (EL) i.e., 70, 140 and 210 kJ/L. The experiments were performed on a pilot scale, and a mixture of thickened primary sludge (TPS) and TES was used as digester feed. The results documented that an important parameter determining the possibility of obtaining an enhanced methane production is the value of energy input in the HC process. This parameter determines the changes occurring in sludge as a result of disintegration (i.e., sludge floc deagglomeration, lysis of cells, re-flocculation process and the related release of compounds susceptible to biodegradation from sludge flocs). The maximum increase in methane yield (MY) of 152% was obtained for EL = 140 kJ/L. In this case, HC mainly caused sludge floc deagglomeration. An increase in MY was also recorded when TES was subject to the disintegration process at EL = 210 kJ/L. However, it was 4.3 times lower than that observed for EL = 140 kJ/L. Pre-treatment of TES at EL = 70 kJ/L did not contribute to an increase in methane production.
Dynamic Voltage Support of Converters during Grid Faults in Accordance with National Grid Code Requirements
Authors: Marchgraber Jürgen , Gawlik Wolfgang
Published: May 2020

To ensure system stability, national grid codes often require converter-based generators to provide fault-ride-through (FRT) capabilities and dynamic voltage support, according to which they should stay connected and support the voltage during fault situations. The requirements for dynamic voltage support include the injection of reactive current in the positive- as well as negative-sequence system, directly proportional to the change of the corresponding voltage between fault and pre-fault. Since this requirement may lead to a reference current surpassing the maximum current capability, the converter control has to contain a proper current limitation. This paper presents an algorithm for such a current limitation and a simulation model of a converter and its control, which applies this algorithm. Based on voltage measurements, which were measured during forced short-circuits in the real grid, the simulation model is used to simulate the behavior of a converter in reaction to these voltage measurements. The results show that the converter control using this algorithm for current limitation guarantees a current output below the maximum current capability while respecting the requirements for dynamic voltage support of the relevant grid codes.
Frequency Stability and Economic Operation of Transactive Multi-Microgrid Systems with Variable Interconnection Configurations
Authors: Lainfiesta Maximiliano , Zhang Xuewei
Published: May 2020

With the progressive addition of microgrids at the distribution level, complex networks of interconnected microgrids and the utility grid are likely to emerge. In such a scenario, advanced microgrid controllers are required to achieve operational stability objectives while maintaining a cost-effective operation. This paper investigates the control strategies, trading mechanisms, and interconnection configurations of a multi-microgrid and utility grid system for frequency stability analysis and operational cost optimization. The analysis is performed on a model of two interconnected microgrids and the utility grid, all possible interconnection configurations are tested. A robust controller is designed and the control parameters are later optimized to ensure that the frequency stability of the system is maintained under normal operating conditions and under various disturbances. A new control element based on switching between interconnection configurations is introduced to handle the power that flows between microgrids, aiming to minimize inter-microgrid energy trading cost while maintaining the system frequency fluctuations within tolerance levels. The effectiveness of the designed controller is demonstrated in this work. This work is expected to provide new insights in the field of multi-microgrid system design.
Systematic Investigation of a Large Two-Stroke Engine Crankshaft Dynamics Model
Authors: Tsitsilonis Konstantinos-Marios , Theotokatos Gerasimos , Xiros Nikolaos , Habens Malcolm
Published: May 2020

The crankshaft dynamics model is of vital importance to a multitude of aspects on engine diagnostics; however, systematic investigations of such models performance (especially for large two-stroke diesel engines that are widely used in the power generation and shipping industries) have not been reported in the literature. This study aims to cover this gap by systematically investigating the parameters that affect the performance of a two-stroke diesel engine crankshaft dynamics model, such as the numerical scheme as well as the engine components inertia and friction. Specifically, the following alternatives are analysed: (a) two optimal performing numerical schemes, in particular, a stiff ordinary differential equations (ODE) solver and a fast solver based on a piecewise Linear Time-Invariant (LTI) scheme method, (b) the linear and the non-linear inertia-speed approaches, and (c) three engine friction submodels of varying complexity. All the potential combinations of the alternatives are investigated, and the crankshaft dynamics model performance is evaluated by employing Key Performance Indicators (KPIs), which consider the results accuracy compared to the measured data, the computational time, and the energy balance error. The results demonstrate that the best performing combination includes the stiff ODE solver, the constant inertia-speed approach and the most simplistic engine friction submodel. However, the LTI numerical scheme is recommended for applications that require fast response due to the significant savings in computational time with an acceptable compromise in the model results accuracy.
Winery Wastewater Treatment by Microalgae to Produce Low-Cost Biomass for Energy Production Purposes
Authors: Spennati Elena , Casazza Alessandro Alberto , Converti Attilio
Published: May 2020

Even though biofuel production from microalgae has become more and more attractive in recent years, it is limited especially by the high cost of microalgae cultivation. However, microalgae can be grown in wastewater in order to reduce their production cost and, at the same time, the polluting impact of wastewaters. Winery wastewaters, which are abundantly released from the wine making process, have a large pollution impact related to their high loads of total solids, chemical oxygen demand (COD) and polyphenol concentration. In this research work a co-culture of Chlorella vulgaris and Arthrospira platensis was used to treat three different winery wastewaters from different steps of the wine production process, in order to produce low-cost biomass intended for biofuel production. Growth of the co-culture and reduction of wastewater pollutant impact were followed by daily determinations of biomass concentration, COD and polyphenol content. The highest productivities of biomass (0.66 gDry Weight/L·day) and lipids (7.10 ± 0.22 gLipid/100 L·day) were obtained using 20% of second washing winery wastewater after 4 days of treatment. Moreover, COD and polyphenol content of the three different wastewaters were reduced by the co-culture by more than 92% and 50%, respectively. These results suggest that winery wastewaters can be used successfully for the growth of A. platensis and C. vulgaris co-culture in order to obtain inexpensive biomass for energy production purposes.
A Minimal Volume Hermetic Packaging Design for High-Energy-Density Micro-Energy Systems
Authors: Yue Xiujun , Grzyb Jessica , Padmanabha Akaash , Pikul James H.
Published: May 2020

Hermetic packaging is critical to the function of many microscale energy storage and harvesting devices. State-of-the-art hermetic packaging strategies for energy technologies, however, are designed for macroscale devices and dramatically decrease the fraction of active materials when applied to micro-energy systems. We demonstrated a minimal volume hermetic packaging strategy for micro-energy systems that increased the volume of active energy storage materials by 2× and 5× compared to the best lab scale microbatteries and commercial pouch cells. The minimal volume design used metal current collectors as a multifunctional hermetic shell and laser-machined hot melt tape to provide a thin, robust hermetic seal between the current collectors with a stronger adhesion to metals than most commercial adhesives. We developed the packaging using commercially available equipment and materials, and demonstrated a strategy that could be applied to many kinds of micro-energy systems with custom shape configurations. This minimal, versatile packaging has the potential to improve the energy density of current micro-energy systems for applications ranging from biomedical devices to micro-robots.
Broadband Impedance Measurement of Lithium-Ion Battery in the Presence of Nonlinear Distortions
Authors: Sihvo Jussi , Roinila Tomi , Stroe Daniel-Ioan
Published: May 2020

The impedance of a Lithium-ion (Li-ion) battery has been shown to be a valuable tool in evaluating the battery characteristics such as the state-of-charge (SOC) and state-of-health (SOH). Recent studies have shown impedance-measurement methods based on broadband pseudo-random sequences (PRS) and Fourier techniques. The methods can be efficiently applied in real-time applications where the conventional electrochemical-impedance spectroscopy (EIS) is not well suited to measure the impedance. The techniques based on the PRS are, however, strongly affected by the battery nonlinearities. This paper presents the use of a direct-synthesis ternary (DST) signal to minimize the effect caused by the nonlinearities. In such a signal, the second- and third-order harmonics are suppressed from the signal energy spectrum. As a result, the effect of the second- and third-order nonlinearities are suppressed from the impedance measurements. The impedance measurements are carried out for a nickel manganese cobalt Li-ion battery cell. The performance of the method is compared to the conventional EIS, as well as to other PRS signals which are more prone to battery nonlinearities. The Kronig–Kramers (K–K) transformation test is used to validate the uniqueness of the measured impedance spectra. It is shown that the measurement method based on the DST produces highly accurate impedance measurements under nonlinear distortions of the battery. The method shows a good K–K test behavior indicating that the measured impedance complies well to a linearized equivalent circuit model that can be used for the SOC and SOH estimation of the battery. Due to the good performance, low measurement time, and simplicity of the DST, the method is well suited for practical battery applications.
Sustainable Utilization of Low Enthalpy Geothermal Resources to Electricity Generation through a Cascade System
Authors: Kaczmarczyk Michał , Tomaszewska Barbara , Operacz Agnieszka
Published: May 2020

The article presents an assessment of the potential for using low temperature geothermal water from the C-PIG-1 well (Małopolskie Voivodship, southern Poland) for electricity generation, as the first stage in a geothermal cascade system. The C-PIG-1 well is characterised by a temperature of geothermal water of 82 °C and a maximum flow rate of 51.22 kg/s. Geothermal water is currently only utilised for recreation purposes in swimming pools. In such locations, with the potential to use renewable energy for energetic purposes, the possibility of comprehensive management of the geothermal waters extracted should be considered both in the first stage of the cascade and after recreational use. Thermodynamic calculations were conducted assuming the use of the Organic Rankine Cycle (ORC) or Kalina Cycle. Two variants were analysed—the use of the maximum flow rate of geothermal waters and partial use with an assumption of a priority for recreational/heating purposes. The analysis and calculations indicate that the gross capacity in the most optimistic variant will not exceed 250 kW for the ORC and 440 kW for the Kalina Cycle. As far as the gross electricity generation is concerned, for ORC this will not exceed 1.9 GWh/year and for the Kalina Cycle it will not exceed 3.5 GWh/year.
Global Energy Security Index and Its Application on National Level
Authors: Azzuni Abdelrahman , Breyer Christian
Published: May 2020

Energy security is an international concern for all countries in the world, particularly, for the policymakers looking for the wellbeing of citizens. While proper methods to measure energy security without ignoring the different aspects and multidimensional interplay is necessary, the need for an objective evaluation with numerical indicators is of utmost importance. This research covers these gaps by providing a detailed numerical method to formulate an energy security index that is globally comprehensive, but also nationally applicable to all countries in the world. This implies to include all needed aspects and dimensions of energy security. Results of this research show the global performance of all countries in the world in energy security and the performance of these countries in each of the 15 dimensions that articulate energy security. Germany and the United States performed best in the world, when it comes to overall energy security levels, whereas the Central African Republic and Turkmenistan are on the lowest end of performance. Conclusions show that there is not a single way for development and enhancing energy security but rather different alternatives and options. Countries need to learn from each other to identify what works best for their context and implement these strategies in order to enhance energy security.
Multi-Objective Sizing Optimization of a Grid-Connected Solar–Wind Hybrid System Using Climate Classification: A Case Study of Four Locations in Southern Taiwan
Authors: Shivam Kumar , Tzou Jong-Chyuan , Wu Shang-Chen
Published: May 2020

Increased concerns over global warming and air pollution has pushed governments to consider renewable energy as an alternative to meet the required energy demands of countries. Many government policies are deployed in Taiwan to promote solar and wind energy to cope with air pollution and self-dependency for energy generation. However, the residential sector contribution is not significant despite higher feed-in tariff rates set by government. This study analyzes wind and solar power availability of four different locations of southern Taiwan, based on the Köppen–Geiger climate classification system. The solar–wind hybrid system (SWHS) considered in this study consists of multi-crystalline photovoltaic (PV) modules, vertical wind turbines, inverters and batteries. Global reanalysis weather data and a climate-based electricity load profile at a 1-h resolution was used for the simulation. A general framework for multi-objective optimization using this simulation technique is proposed for solar–wind hybrid system, considering the feed-in tariff regulations, environmental regulations and installation area constraints of Taiwan. The hourly load profile is selected using a climate classification system. A decomposition-based differential evolutionary algorithm is used for finding the optimal Pareto set of two economic objectives and one environmental objective with maximum installation area and maximum PV capacity constraints. Two types of buildings are chosen for analysis at four climate locations. Analysis of Pareto sets revealed that the photovoltaic modules are economic options for a grid-connected mode at all four locations, whereas solar–wind hybrid systems are more environmentally friendly. A method of finding the fitness index for the Pareto front sets and a balanced strategy for choosing the optimal configuration is proposed. The proposed balanced strategy provides savings to users—up to 49% for urban residential buildings and up to 32% for rural residential buildings with respect to buildings without a hybrid energy system (HES)—while keeping carbon dioxide (CO2) emissions lower than 50% for the total project lifecycle time of 20 years. The case study reveals that for all four locations and two building types an HES system comprising a 15 kW photovoltaic system and a small capacity battery bank provides the optimal balance between economic and environmental objectives.
Design of Adaptive Controller Exploiting Learning Concepts Applied to a BLDC-Based Drive System
Authors: Dini Pierpaolo , Saponara Sergio
Published: May 2020

This work presents an innovative control architecture, which takes its ideas from the theory of adaptive control techniques and the theory of statistical learning at the same time. Taking inspiration from the architecture of a classical neural network with several hidden levels, the principle is to divide the architecture of the adaptive controller into three different levels. Each level implements an algorithm based on learning from data and therefore we can talk about learning concepts. Each level has a different task: the first to learn the required reference to the control loop; the second to learn the coefficients of the state representation of a model of the system to be controlled; and finally, the third to learn the coefficients of the state representation of the actual controller. The design of the control system is reported from both a rigorous and an operational point of view. As an application example, the proposed control technique is applied on a second-order non-linear system. We consider a servo-drive based on a brushless DC (BLDC) motor, whose dynamic model considers all the non-linear effects related to the electromechanical nature of the electric machine itself, and also an accurate model of the switching power converter. The reported example shows the capability of the control algorithm to ensure trajectory tracking while allowing for disturbance rejection with different disturbance signal amplitude. The implementation complexity analysis of the new controller is also proposed, showing its low overhead vs. basic control solutions.
Effects of Chemical and Natural Additives on Cucumber Juice’s Quality, Shelf Life, and Safety
Authors: El-Saadony Mohamed T. , Elsadek Mohamed F. , Mohamed Alaa S. , Taha Ayman E. , Ahmed Badreldin M. , Saad Ahmed M.
Published: May 2020

Microbial contamination affects beverages’ lifetime, quality, and safety. Cucumber crops are seasonally spoiled because of the overproduction. The current study aimed to maximize the importance of natural preservatives and reduce the usage of artificial ones to prolong the cucumber juice’s storage life, enhance flavor, and control the microorganisms after protein isolate and organic acids supplementation. The additions included control (no addition), citric, benzoic acid, sodium salts, kidney bean pepsin hydrolysate (KPH), chicken egg protein isolate (CEPI), duck egg protein isolate (DEPI), and quail egg protein isolate (QEPI) as J-Control, J-Citric, J-Benzoic, J-sod. Citrate, J-sod. Benzoate, J-KPH, J-CEPI, J-DEPI, and J-QEPI, respectively. The antioxidant activity of these additives and juices was evaluated by DPPH radical scavenging activity. The antimicrobial activity, including antibacterial and antifungal activities, was evaluated by using disc assay and the radial growth of fungal mycelium, respectively. The phenolic compounds and flavonoids were estimated by a spectrophotometer as Gallic acid equivalent (GAE) and quercetin equivalent (QE), respectively. Moreover, chemical parameters such as pH, total soluble solids (TSS), Titratable acidity (TTA), and Vitamin C were evaluated by AOAC. Finally, the color properties were estimated by a spectrophotometer, using the Hunter method. KPH had higher significant (p ≤ 0.05) antioxidant activity (88%), along with antimicrobial activity. It significantly (p ≤ 0.05) reduced the growth of G+ and G− bacteria by 71–97% and 58–66% respectively. Furthermore, it significantly (p ≤ 0.05) inhibited the tested fungi growth by 70–88% and the other additives less than that. During the storage of cucumber juice for an interval of zero, two, four, and six months, the phenolic compounds and flavonoids were significantly (p ≤ 0.05) decreased. Consequently, the potential activity of the juice was reduced; in addition, pH and vitamin C were significantly (p ≤ 0.05) decreased during the storage period. Meanwhile, the TSS and Titratable acidity were significantly raised. As for color and sensory properties, J-sod. Benzoate, J-KPH, J-CEPI, and J-DEPI had significantly (p ≤ 0.05) high scores in color, taste, and flavor against the control. Generally, the usage of natural additives extends the cucumber juice’s lifetime and increased the manufacture of high-quality and valuable juice.
Detection of a Novel, and Likely Ancestral, Tn916-Like Element from a Human Saliva Metagenomic Library
Authors: Reynolds Liam J. , Anjum Muna F. , Roberts Adam P.
Published: May 2020

Tn916 is a conjugative transposon (CTn) and the first reported and most well characterised of the Tn916/Tn1545 family of CTns. Tn916-like elements have a characteristic modular structure and different members of this family have been identified based on similarities and variations in these modules. In addition to carrying genes encoding proteins required for their conjugation, Tn916-like elements also carry accessory, antimicrobial resistance genes; most commonly the tetracycline resistance gene, tet(M). Our study aimed to identify and characterise tetracycline resistance genes from the human saliva metagenome using a functional metagenomic approach. We identified a tetracycline-resistant clone, TT31, the sequencing of which revealed it to encode both tet(M) and tet(L). Comparison of the TT31 sequence with the accessory, regulation, and recombination modules of other Tn916-like elements indicated that a partial Tn916-like element encoding a truncated orf9 was cloned in TT31. Analysis indicated that a previous insertion within the truncated orf9 created the full length orf9 found in most Tn916-like transposons; demonstrating that orf9 is, in fact, the result of a gene fusion event. Thus, we hypothesise that the Tn916-like element cloned in TT31 likely represents an ancestral Tn916.
Interindividual Variation in Cardiorespiratory Fitness: A Candidate Gene Study in Han Chinese People
Authors: Gaowa  , Del Coso Juan , Gu Zhuangzhuang , Gerile Wuyun , Yang Rui , Díaz-Peña Roberto , Valenzuela Pedro L. , Lucia Alejandro , He Zihong
Published: May 2020

Cardiorespiratory fitness, as assessed through peak oxygen uptake (VO2peak), is a powerful health indicator. We aimed to evaluate the influence of several candidate causal genetic variants on VO2peak level in untrained Han Chinese people. A total of 1009 participants (566 women; age [mean ± SD] 40 ± 14 years, VO2peak 29.9 ± 7.1 mL/kg/min) performed a maximal incremental cycling test for VO2peak determination. Genomic DNA was extracted from peripheral whole blood, and genotyping analysis was performed on 125 gene variants. Using age, sex, and body mass as covariates, and setting a stringent threshold p-value of 0.0004, only one single nucleotide polymorphism (SNP), located in the gene encoding angiotensin-converting enzyme (rs4295), was associated with VO2peak (β = 0.87; p < 2.9 × 10−4). Stepwise multiple regression analysis identified a panel of three SNPs (rs4295 = 1.1%, angiotensin II receptor type 1 rs275652 = 0.6%, and myostatin rs7570532 = 0.5%) that together accounted for 2.2% (p = 0.0007) of the interindividual variance in VO2peak. Participants carrying six ‘favorable’ alleles had a higher VO2peak (32.3 ± 8.1 mL/kg/min) than those carrying only one favorable allele (24.6 ± 5.2 mL/kg/min, p < 0.0001). In summary, VO2peak at the pre-trained state is partly influenced by several polymorphic variations in candidate genes, but they represent a minor portion of the variance.
The Rockall and the Orphan Basins of the Southern North Atlantic Ocean: Determining Continuous Basins across Conjugate Margins
Authors: MacMahon Heide , Welford J. Kim , Sandoval Larry , Peace Alexander L.
Published: May 2020

Reconstructions of the opening of the North Atlantic Ocean generally result in the Orphan Basin, offshore Newfoundland, Canada, lying approximately conjugate to the rift basins on the Irish Atlantic margin at the onset of seafloor spreading toward the end of the Early Cretaceous. Most of these plate reconstructions have involved rigid plates with plate motions based solely on the interpretation of oceanic magnetic anomalies. In particular, these reconstructions often show the Rockall Basin, west of Ireland, forming a continuous Mesozoic basin with the West Orphan Basin, offshore Newfoundland. However, more recent plate reconstructions involving deformable plates have called this conjugate relationship into question. The goal of this study is to investigate the validity of this potentially continuous basin system by reconstructing and restoring present-day seismically-constrained geological models both spatially and temporally back to their original configurations pre-rift. By comparing the reconstructions in terms of sedimentary package thicknesses and crustal thicknesses in 3D, using both rigid and deformable plate reconstructions to orient the reconstructed models, we are able to test different basin connectivity scenarios using a multidisciplinary approach. Our analysis provides subsurface geophysical support for the hypothesis that the Rockall Basin was originally conjugate to and continuous with the East Orphan Basin during Jurassic rifting, later linking to the West Orphan Basin as rifting evolved during the Early Cretaceous. This complex basin evolution example highlights the need for using 3D rifting mechanism models to properly understand the fundamental driving forces during rifting and has significant implications for assessing basin prospectivity across conjugate margin pairs.
Healthcare Data Breaches: Insights and Implications
Authors: Seh Adil Hussain , Zarour Mohammad , Alenezi Mamdouh , Sarkar Amal Krishna , Agrawal Alka , Kumar Rajeev , Ahmad Khan Raees
Published: May 2020

The Internet of Medical Things, Smart Devices, Information Systems, and Cloud Services have led to a digital transformation of the healthcare industry. Digital healthcare services have paved the way for easier and more accessible treatment, thus making our lives far more comfortable. However, the present day healthcare industry has also become the main victim of external as well as internal attacks. Data breaches are not just a concern and complication for security experts; they also affect clients, stakeholders, organizations, and businesses. Though the data breaches are of different types, their impact is almost always the same. This study provides insights into the various categories of data breaches faced by different organizations. The main objective is to do an in-depth analysis of healthcare data breaches and draw inferences from them, thereby using the findings to improve healthcare data confidentiality. The study found that hacking/IT incidents are the most prevalent forms of attack behind healthcare data breaches, followed by unauthorized internal disclosures. The frequency of healthcare data breaches, magnitude of exposed records, and financial losses due to breached records are increasing rapidly. Data from the healthcare industry is regarded as being highly valuable. This has become a major lure for the misappropriation and pilferage of healthcare data. Addressing this anomaly, the present study employs the simple moving average method and the simple exponential soothing method of time series analysis to examine the trend of healthcare data breaches and their cost. Of the two methods, the simple moving average method provided more reliable forecasting results.
Analytical and Numerical Groundwater Flow Solutions for the FEMME-Modeling Environment
Authors: El-Rawy Mustafa , Batelaan Okke , Buis Kerst , Anibas Christian , Mohammed Getachew , Zijl Wouter , Salem Ali
Published: May 2020

Simple analytical and numerical solutions for confined and unconfined groundwater-surface water interaction in one and two dimensions were developed in the STRIVE package (stream river ecosystem) as part of FEMME (flexible environment for mathematically modelling the environment). Analytical and numerical solutions for interaction between one-dimensional confined and unconfined aquifers and rivers were used to study the effects of a 0.5 m sudden rise in the river water level for 24 h. Furthermore, a two-dimensional groundwater model for an unconfined aquifer was developed and coupled with a one-dimensional hydrodynamic model. This model was applied on a 1 km long reach of the Aa River, Belgium. Two different types of river water level conditions were tested. A MODFLOW model was set up for these different types of water level condition in order to compare the results with the models implemented in STRIVE. The results of the analytical solutions for confined and unconfined aquifers were in good agreement with the numerical results. The results of the two-dimensional groundwater model developed in STRIVE also showed that there is a good agreement with the MODFLOW solutions. It is concluded that the facilities of STRIVE can be used to improve the understanding of groundwater-surface water interaction and to couple the groundwater module with other modules developed for STRIVE. With these new models STRIVE proves to be a powerful example as a development and testing environment for integrated water modeling.
Bivariate Spatial Pattern between Smoking Prevalence and Lung Cancer Screening in US Counties
Authors: Liu Bian , Sze Jeremy , Li Lihua , Ornstein Katherine A. , Taioli Emanuela
Published: May 2020

Objectives: Lung cancer screening (LCS) with low-dose computed tomography (LDCT) has been a reimbursable preventive service covered by Medicare since 2015. Geographic disparities in the access to LDCT providers may contribute to the low uptake of LCS. We evaluated LDCT service availability for older adults in the United States (US) based on Medicare claims data and explored its ecological correlation with smoking prevalence. Materials and Methods: We identified providers who provided at least 11 LDCT services in 2016 using the Medicare Provider Utilization and Payment Data: Physician and Other Supplier Public Use File. We constructed a 30-mile Euclidian distance buffer around each provider’s location to estimate individual LDCT coverage areas. We then mapped the county-level density of LDCT providers and the county-level prevalence of current daily cigarette smoking in a bivariate choropleth map. Results: Approximately 1/5 of census tracts had no LDCT providers within 30 miles and 46% of counties had no LDCT services. At the county level, the median LDCT density was 0.5 (interquartile range (IQR): 0–5.3) providers per 1000 Medicare fee-for-service beneficiaries, and cigarette smoking prevalence was 17.5% (IQR: 15.2–19.8%). High LDCT service availability was most concentrated in the northeast US, revealing a misalignment with areas of high current smoking prevalence, which tended to be in the central and southern US. Conclusions: Our maps highlight areas in need for enhanced workforce and capacity building aimed at reducing disparities in the access and utilization of LDCT services among older adults in the US.
Mediating Effects of Emotional Symptoms on the Association between Homophobic Bullying Victimization and Problematic Internet/Smartphone Use among Gay and Bisexual Men in Taiwan
Authors: Li Dian-Jeng , Chang Yu-Ping , Chen Yi-Lung , Yen Cheng-Fang
Published: May 2020

Problematic internet/smartphone use (PI/SU) and homophobic bullying has become a new type of mental health problem among sexual minorities. However, few studies have investigated the mediators of the association between these factors. We aimed to develop a model to estimate the mediating effect of emotional symptoms, including depression and anxiety, on this association among gay and bisexual men in Taiwan. In total, 500 gay or bisexual men in early adulthood were recruited, and their histories of homophobic bullying victimization during childhood and adolescence, current severity of PI/SU, and current emotional symptoms were evaluated using self-administered questionnaires. A mediation model was developed to test the mediating effect of emotional symptoms on the association between homophobic bullying victimization and PI/SU. In total, 190 (38%) and 201 (40.2%) of the participants had experiences of traditional and cyber homophobic bullying victimization, respectively. A higher level of homophobic bullying victimization was significantly associated with a more severe level of PI/SU, and this was mediated by a higher severity of emotional symptoms. There was a significant effect of emotional symptoms on the association between homophobic bullying victimization and PI/SU. Timely interventions for emotional symptoms are necessary for gay and bisexual men, especially for those who are victims of homophobic bullying.
Government Intervention, Risk Perception, and the Adoption of Protective Action Recommendations: Evidence from the COVID-19 Prevention and Control Experience of China
Authors: Duan Taixiang , Jiang Hechao , Deng Xiangshu , Zhang Qiongwen , Wang Fang
Published: May 2020

This study examines the relationships between government interventions, risk perception, and the public’s adoption of protective action recommendations (PARs) during the COVID-19 coronavirus disease emergency in mainland China. We conducted quota sampling based on the proportion of the population in each province and gender ratios in the Sixth Census and obtained a sample size of 3837. Government intervention was divided into government communication, government prevention and control, and government rescue. We used multiple regression and a bootstrap mediation effect test to study the mechanism of these three forms of government intervention on the public’s adoption of PARs. The results show that government prevention and control and government rescue significantly increased the likelihood of the public adopting PARs. Risk perception was significantly associated with the public’s adoption of PARs. The effects of government interventions and risk perception on the public’s adoption of PARs was not found to vary by region. Risk perception is identified as an important mediating factor between government intervention and the public’s adoption of PARs. These results indicate that increasing the public’s risk perception is an effective strategy for governments seeking to encourage the public to adopt PARs during the COVID-19 pandemic.
An Explanatory Model of Sexual Satisfaction in Adults with a Same-Sex Partner: An Analysis Based on Gender Differences
Authors: Calvillo Cristóbal , Sánchez-Fuentes María del Mar , Sierra Juan Carlos
Published: May 2020

This study aimed to develop an explanatory model of sexual satisfaction in same-sex attracted individuals with a partner, based on personal and interpersonal variables. The participants were 410 men (mean age = 29.24, SD = 9.84) and 410 women (mean age = 29, SD = 8.57) who maintained a relationship with another person of the same sex. Internalized homophobia was considered as a personal variable, and as interpersonal variables, the dimensions of attachment (anxiety and avoidance), sexual functioning, dyadic adjustment, relationship satisfaction, the components of the Interpersonal Exchange Model of Sexual Satisfaction, the number of sexual costs and the number of sexual rewards were considered. The degree to which sexual satisfaction was related to these variables was examined separately, for both men and women, through multiple linear regression models within the framework of structural equation models. The results indicated that sexual satisfaction is associated in a negative sense with internalized homophobia, the number of sexual costs, anxiety, and avoidance, and in a positive sense with the remaining variables. Relational variables were more relevant in the explanation of sexual satisfaction. The clinical implications are discussed.
Trend in the Prevalence of Non-Daily Smoking and Their Relationship with Mental Health Using the Korea Health and Nutrition Examination Survey
Authors: Kwan Yunna , Kim Hye Sim , Kang Dae Ryong , Kim Tae Hui
Published: May 2020

Introduction: Non-Daily Smoking (NDS), which is increasingly prevalent worldwide, has not yet attracted as much attention as has daily smoking in Asia. The aims of this study were to identify trends in the prevalence of NDS and to compare characteristics by age, gender, and mental health indicators such as depression, suicidality, and alcohol consumption in South Korea. Methods: We included 33,806 adults (aged ≥ 19 years) who participated in the Korean National Health and Nutrition Examination Survey (KNHNES) from 2010 to 2015. The dataset includes self-reported medical history and questionnaires that explore depression, suicidality, and alcohol use, which are known to be highly related to smoking. We divided the respondents into four groups according to smoking status: Never Smoking (NS, N = 20,270); Past Smoking (PS = 6835); Daily Smoking (DS = 5927), who reported smoking every day; and Non-Daily Smoking (NDS = 774), who reported that they sometimes smoke. Results: Increased NDS prevalence is observed in most age groups in both male and female adults despite the prevalence of total smoking and daily smoking gradually decreasing. Depression and suicidality were significantly more prevalent in the NDS than the NS group (Depression Odds ratio, OR = 1.72, 95% Confidence interval, CI = 1.31–2.26; Suicidality OR = 3.14, 95% CI = 1.40–7.02). NDS is also associated with a higher frequency of binge drinking and alcohol use disorder than NS (OR = 4.17, 95% CI = 3.49–4.99). Conclusions: This study suggests that more concern is warranted for NDS given the increasing prevalence and characteristics of poor mental health in NDS respondents.
Critical Hazards Identification and Prevention of Cascading Escalator Accidents at Metro Rail Transit Stations
Authors: Wang Zhiru , Bhamra Ran S. , Wang Min , Xie Han , Yang Lili
Published: May 2020

Escalator accidents not only happen frequently but also have cascading effects. The purpose of this study is to block the formation of cascading accident networks by identifying and preventing critical hazards. A modified five-step task-driven method (FTDM) is proposed to break down passenger-related cascading escalator accidents. Three complex network parameters in complex network theory are utilized to identify critical and non-critical Risk Passenger Behavior (RPB) hazards and Other Hazards related with Risk Passenger Behavior (OH-RPB) in accident chains. A total of 327 accidents that occurred in the Beijing metro rail transit (MRT) stations were used for case studies. The results are consistent in critical and non-critical RPB and OH-RPB and prove that through combination of FTDM accident investigation model and complex network analysis method, critical and non-critical RPB and OH-RPB in a complicated cascading hazards network can be identified. Prevention of critical RPB can block the formation of cascading accident networks. The method not only can be used by safety manager to make the corresponding preventive measures according to the results in daily management but also the findings can guide the allocation of limited preventive resources to critical hazards rather than non-critical hazards. Moreover, the defects of management plan and product design can be re-examined according to the research results.
Experiences of Overseas Trained Physical Therapists Working in Saudi Arabia: An Observational Study
Authors: Alghadir Ahmad H. , Zafar Hamayun , Iqbal Zaheen A.
Published: May 2020

Background: Health professionals, including physical therapists (PTs), are known to migrate for better jobs, as well as for personal and professional development. However, this involves risks of maladjustment, discrimination, and exploitation. We conducted this study to investigate the experiences of overseas trained PTs in Saudi Arabia (SA) and their perceptions about physical therapy practice and problems regarding the profession in the country. Methods: A questionnaire and accompanying explanation of the study was sent to 175 members of the Saudi Physical Therapy Association (SPTA) working in SA who had been trained outside SA and had a minimum of one year of work experience before moving to SA. Results: One hundred and fifty (86%) respondents completed the questionnaire. Among the respondents, the majority had more than five years of work experience after moving to SA. While 54% of the respondents reported that they were satisfied with their work experiences in SA, the remaining respondents reported their dissatisfaction for various reasons. Conclusions: With the increase in aged population and rise in disability, the need for PTs has simultaneously increased in the health care sector around the world, including in SA. Until PTs of local origin are ready to fill the requirements, the services of PTs from other countries will be required in SA. Although the majority of respondents reported having positive work experiences in SA, the negative aspects and challenges faced by PTs in SA have also been highlighted in this study. These problems need to be addressed in order to promote the development of a better and more holistic approach to patient care.
Social Capital, Deprivation and Psychological Well-Being among Young Adolescents: A Multilevel Study from England and Wales
Authors: Jonsson Kenisha Russell , Busfield Joan , Södergren Marita , Karen Miia , Adjei Nicholas Kofi
Published: May 2020

Examining the mechanisms influencing mental health and life satisfaction simultaneously allows for a better understanding of adolescents psychological well-being. Six indicators of neighbourhood social capital (NSC), neighbourhood socioeconomic deprivation (SecD) and their association with psychological well-being among young adolescents aged 10-15 from England and Wales were investigated. Using a random sample of 5201 adolescents (7253 observations) from the UK Household Longitudinal Study merged to aggregated local area census measures, we fitted a series of multilevel models. The findings showed that not being worried about crime and friendship networks mitigated the negative effects of deprivation on adolescent’s psychological well-being. These findings suggest that some forms of NSC may have a buffering and protective function, with the strongest effects in deprived neighbourhoods. We further found that psychological well-being of adolescents is dependent on both individual vulnerabilities and neighbourhood context. However caution is required if, and when public health policies are formulated to address this issue, given significant variations (27-36%) in the inter- and intra-individual psychological well-being were found among this group over time. Thus, policies designed to improve psychological well-being among adolescents should take into account the role of social processes in transmitting deprivation’s effects, as well as the various forms of social capital.