bluuebunny/crossref_metadata_2025 huggingface dataset:
Smart District and Circular Economy: The Role of ICT Solutions in Promoting Circular Cities
Authors: Viglioglia Massimiliano , Giovanardi Matteo , Pollo Riccardo , Peruccio Pier Paolo
Published: October 2021

Cities will have a decisive role in reducing the consumption of resources and greenhouse gas emissions by 2050. Various experiences of urban regeneration have exploited Information and Communication Technology (ICT) potentialities to optimize the management of complex systems and to encourage sustainable development models. This paper investigates the role of ICT technologies in favouring emerging design for Circular Economy (CE) in the urban context. The paper starts by defining the theoretical background and subsequently presents the goal and methodology of investigation. Through a scoping review, the authors identify case studies and analyse them within the Ellen MacArthur Foundation classification framework that splits the urban context into three urban systems: buildings, mobility and products. The research focuses on nine case studies where the ICT solutions were able to promote the principles of CE. The results show, on the one hand, how data management appears to be a central issue in the optimization of urban processes and, on the other hand, how the district scale is the most appropriate to test innovative solutions. This paper identifies physical and virtual infrastructures, stakeholders and tools for user engagement as key elements for the pursuit of CE adoption in the urban context.
Demand Side Management Techniques for Home Energy Management Systems for Smart Cities
Authors: Hussain Muhammad Majid , Akram Rizwan , Memon Zulfiqar Ali , Nazir Mian Hammad , Javed Waqas , Siddique Muhammad
Published: October 2021

In this paper, three distinct distributed energy resources (DERs) modules have been built based on demand side management (DSM), and their use in power management of dwelling in future smart cities has been investigated. The investigated modules for DERs system are: incorporation of load shedding, reduction of grid penetration with renewable energy systems (RES), and implementation of home energy management systems (HEMS). The suggested approaches offer new potential for improving demand side efficiency and helping to minimize energy demand during peak hours. The main aim of this work was to investigate and explore how a specific DSM strategy for DER may assist in reducing energy usage while increasing efficiency by utilizing new developing technology. The Electrical Power System Analysis (ETAP) software was used to model and assess the integration of distributed generation, such as RES, in order to use local power storage. An energy management system has been used to evaluate a PV system with an individual household load, which proved beneficial when evaluating its potential to generate about 20–25% of the total domestic load. In this study, we have investigated how smart home appliances’ energy consumption may be minimized and explained why a management system is required to optimally utilize a PV system. Furthermore, the effect of integration of wind turbines to power networks to reduce the load on the main power grid has also been studied. The study revealed that smart grids improve energy efficiency, security, and management whilst creating environmental awareness for consumers with regards to power usage.
Impact of Particle Sizes, Mineralogy and Pore Fluid Chemistry on the Plasticity of Clayey Soils
Authors: Won Jongmuk , Park Junghee , Kim Junki , Jang Junbong
Published: October 2021

The current classification of clayey soils does not entail information of pore fluid chemistry and particle size less than 75 µm. However, the pore fluid chemistry and particle size (at given mineralogy) are critical in the plasticity of clayey soils because of their impact on negative charge density. Therefore, this study extensively discusses the description of clay with respect to mineralogy, particle sizes, and pore fluid chemistry based on liquid and plastic limits of kaolinite, illite, and bentonite, and estimates undrained shear strength from the observed liquid limits. The liquid limits and undrained shear strength estimated from the observed liquid limits as a function of mineralogy (clay type), particle size, and ionic concentration reveal the need of incorporating pore fluid chemistry and particle size into the fines classification system. Furthermore, multiple linear regression models developed in this study demonstrate the importance of particle size and ionic concentration in predicting the liquid limit of clayey soils. This study also discusses the need for a comprehensive understanding of fines classification for proper interpretation of natural phenomena and engineering applications for fine-grained sediments.
Building Organisational Sustainability during the COVID-19 Pandemic with an Inspiring Work Environment
Authors: Rožman Maja , Peša Anita , Rajko Mladen , Štrukelj Tjaša
Published: October 2021

This article aims to analyse significant differences in four constructs: occupational stress, job satisfaction, work engagement, and work productivity among employees before and after the COVID-19 pandemic. The purpose of the paper is to develop a multidimensional model with these four constructs and analyse the differences in the strength of their effects on the model across two intersectional times: before the COVID-19 pandemic and during the COVID-19 pandemic. The research was implemented on a sample of 885 employees in Slovenian organisations. During COVID-19, Slovenia had one of the strictest lockdowns. Based on the research, we can confirm significant differences in the four analysed constructs among employees before COVID-19 and during COVID-19. Based on the results, we can confirm that occupational stress had a more negative effect on job satisfaction and work engagement during COVID-19 than before prior to it. Our research and conclusions highlight the measures with which organisations can reduce the problem of occupational stress and with which organisations can increase job satisfaction, work engagement and work productivity among employees during COVID-19. Based on this, organisations may be able to build a more supportive work environment during, and after, COVID-19.
Perceived Effects of Climate Change and Extreme Weather Events on Forests and Forest-Based Livelihoods in Malawi
Authors: Chisale Harold L. W. , Chirwa Paxie W. , Babalola Folaranmi D. , Manda Samuel O. M.
Published: October 2021

The emerging risks and impacts of climate change and extreme weather events on forest ecosystems present significant threats to forest-based livelihoods. Understanding climate change and its consequences on forests and the livelihoods of forest-dependent communities could support forest-based strategies for responding to climate change. Using perception-based assessment principles, we assessed the effects of climate change and extreme weather events on forests and forest-based livelihood among the forest-dependent communities around the Mchinji and Phirilongwe Forest Reserves in the Mchinji and Mangochi districts in Malawi. Content analysis was used to analyze qualitative data. The impact of erratic rainfall, high temperatures, strong winds, flooding, and droughts was investigated using logistic regression models. The respondents perceived increasing erratic rainfall, high temperatures, strong winds, flooding, and droughts as key extreme climate events in their locality. These results varied significantly between the study sites (p < 0.05). Erratic rainfall was perceived to pose extended effects on access to the forest in both Phirilongwe in Mangochi (43%) and Mchinji (61%). Climate change was found to be associated with reduced availability of firewood, thatch grasses, fruits and food, vegetables, mushrooms, and medicinal plants (p < 0.05). Erratic rainfall and high temperatures were more likely perceived to cause reduced availability of essential forest products, and increased flooding and strong winds were less likely attributed to any effect on forest product availability. The study concludes that climate change and extreme weather events can affect the access and availability of forest products for livelihoods. Locally based approaches such as forest products domestication are recommended to address threats to climate-sensitive forest-based livelihoods.
Agent-Based Modeling and Simulation of Tourism Market Recovery Strategy after COVID-19 in Yunnan, China
Authors: Luo Yumei , Li Yuwei , Wang Guiping , Ye Qiongwei
Published: October 2021

The tourism industry hit severely by COVID-19 faces the challenge of developing effective market recovery strategies. Nonetheless, the existing literature is still limited regarding the dynamic evolution process and management practice. Hence, this study chose several famous spots in the Yunnan Province of China as the focus for a case study and utilized an agent-based simulation method for the decision-making process of tourists’ destination selection and the dynamic recovery process of the destinations under different price and information strategies. The study found that the recovery effects of information strategies are positive, negative, or have no effect in different destinations. In contrast, price strategies can significantly stimulate an increase in the market share of destinations. When price strategy and information strategy are applied simultaneously, the interaction effects are inconsistent in different destinations. The findings contribute to the prediction of the recovery effect of strategies, can reduce trial and error costs, and can improve the scientific understanding of tourism market recovery.
Homeowner Preferences for Wildfire Risk Mitigation in the Alaskan Wildland Urban Interface
Authors: Molina Allen , Little Joseph , Drury Stacy , Jandt Randi
Published: October 2021

Wildfire has become a larger threat to human life and property with the proliferation of homes into the wildland urban interface and warming climate. In this study we explored Alaskan homeowner preferences for wildfire risk mitigation in the wildland urban interface using discrete choice experiments to better understand the drivers of their risk mitigation actions. Estimates of willingness-to-pay for private mitigation actions are increased with wildfire risk reduction for all respondents. Willingness-to-pay for private mitigation is also positively associated with the presence of thinned fuel treatments on nearby public lands, but is estimated to decrease if cleared fuel treatments are present on public lands. Our study concludes that homeowners minimize wildfire risk while maintaining neighborhood amenity values. Additionally, findings suggest that there is an optimal amount of neighborhood participation to motivate individual risk mitigation actions, as well as having a say in the mitigation actions on public lands.
Investment and Profitability of Community Heating Systems Using Bioenergy in Finland: Opportunities and Challenges
Authors: KC Raghu , Föhr Jarno , Gyawali Arun , Ranta Tapio
Published: October 2021

Oil heating systems are abundant in rural Finland and they need to be replaced by renewable energy as Finland aims to be carbon neutral by 2035. Bioenergy, one of the renewable energies, is a common source of energy in Finland as the country is rich in forest resources. In Finland, combined heat and power plants utilize such resource to produce district heat and electricity but Finnish rural areas do not have access to the district heating network. However, there are potential scenarios where community heating could be possible using portable chip-fired heating systems (heat containers). Ultimately, the cost of heating is an important factor for the consumers and the cost of investment is likely to put off any interest from the communities. In this research, we explored the cost and profitability of heat container investments in rural Finland and examined the challenges for the energy transition away from oil heating systems, as well as the opportunities decentralized biomass-fired heating systems might bring. The results of this research indicate that the price of heat produced in heat containers is comparatively higher than district heating, which is commonly used in cities in Finland, but is cost-competitive compared to oil heating depending on the price of oil. For example, the current price of LFO (~1 EUR/l) generates costlier heat than the 300 kW heat container provides. Firing wood pellets in the heat container is not economically viable due to expensive raw material but smaller-sized heat container (110 kW) firing wood chips could provide cost-competitive heat if uptime is raised to >2700 h/year. There are socio-economic impacts and value-added effects on the rural region due to utilization of local resource instead of imported LFO but there remain challenges and barriers such as high initial investment, low investment support and lack of policies focused on decentralised energy enterprises.
Participation and Achievement in the Summer Paralympic Games: The Influence of Income, Sex, and Assistive Technology
Authors: Oggero Giulia , Puli Louise , Smith Emma Maria , Khasnabis Chapal
Published: October 2021

Global participation at the Paralympic Games has been steadily growing in the past 60 years. However, inequities in relation to geographic representation of Paralympians, sex representation, access to assistive technology, and medal success remain. The objectives of this research are to describe and compare trends in Paralympians’ participation and achievements in the Summer Paralympic Games by income level and sex, including in events requiring assistive products (wheelchairs, hand cycles/trikes, and prostheses). A retrospective secondary analysis of publicly available data was conducted. Participation, sex, and medal tally data were extracted from data available on the International Paralympic Committee website and archives. Data regarding income and population were collected from publicly available data available from the World Bank website. Participation in the Summer Paralympic Games differs significantly by income level (p = 0.000) with high- income countries sending, on average, more Paralympians than low- and middle-income countries. There is a significant difference between male and female participation (p = 0.00), with approximately 29% of all Paralympians being female. High-income countries demonstrate significantly higher achievement than low- and middle-income countries (p = 0.000), including in events requiring assistive products (p = 0.007). Despite growth in overall participation, low- and middle-income countries remain severely underrepresented in both participation and achievement at the Paralympic Games, especially in the events that require high quality assistive products to succeed. More equitable participation and achievement in the Paralympics may be supported by addressing the barriers for females, for people from low- and low-middle income countries, and for those without access to high quality assistive products required.
Prediction of Adolescent Physical Self-Concept through Autonomous Motivation and Basic Psychological Needs in Spanish Physical Education Students
Authors: Valero-Valenzuela Alfonso , Huescar Elisa , Núñez Juan L. , Conte Luis , Léon Jaime , Moreno-Murcia Juan Antonio
Published: October 2021

Framed within the theoretical support of the Self-determination Theory (SDT) this study aimed to analyze the relationship between the satisfaction of basic psychological needs, the self-determined motivation towards physical education, and the physical self-concept of Spanish teenagers. For this, 618 students, aged from 10 to 14 years-old (M = 11.62, SD = 0.94), participated in physical education classes. The Basic Psychological Needs Satisfaction Scale (PNSE), the dimensions of intrinsic motivation and identified motivation of the Perceived Locus of Causality Scale in physical education classes (PLOC), and the Physical Self-Concept Questionnaire (PSPP) were administered. A structural equation model and test confirmatory factor analysis were used. The results indicate a positive relationship between the satisfaction of the basic psychological needs of the students and the self-determined motivation towards physical education, with this being positively associated with the physical self-concept of the students. In addition, a prediction model (χ2 = 763.23; p < 0.001; χ2/d.f. = 3.00; IFI = 0.91; CFI = 0.91; TLI = 0.90; RMSEA = 0.05) showed the satisfaction of basic psychological needs positively predicted their self-determined motivation towards physical education, and this, in turn, a greater physical self-concept of the students. The results are discussed centered on the importance of the physical education teacher contemplating experiences that work on the promotion of personal identity and student self-esteem through the improvement of quality motivation. Consequently, the greater importance of the physical self-concept of the students was explained thanks to more autonomous (intrinsic and identified regulation) motivation and higher levels of basic psychological needs (especially autonomy and competence).
Effect of Woody Biomass Gasification Process Conditions on the Composition of the Producer Gas
Authors: Lyons Cerón Alejandro , Konist Alar , Lees Heidi , Järvik Oliver
Published: October 2021

Using woody biomass in thermochemical gasification can be a viable alternative for producing renewable energy. The type of biomass and the process parameters influence the producer gas composition and quality. This paper presents research on the composition of the producer gas from the gasification of three woody biomass species: spruce, alder, and pine. The experiments were conducted in a drop-tube reactor at temperatures of 750, 850, and 950 °C, using air as the gasifying agent, with equivalence ratios of 0.38 and 0.19. Gas chromatography with a thermal conductivity detector was used to determine the composition of the producer gas, while the production of total organic compounds was detected using Fourier-transform infrared spectroscopy. All three wood species exhibited very similar producer gas composition. The highest concentration of combustible gases was recorded at 950 °C, with an average of 4.1, 20.5, and 4.6 vol% for H2, CO, and CH4, respectively, and a LHV ranging from 4.3–5.1 MJ/m3. The results were in accordance with other gasification studies of woody species. Higher temperatures enhanced the composition of the producer gas by promoting endothermic and exothermic gasification reactions, increasing gas production while lowering solid and tar yields. The highest concentrations of combustible gases were observed with an equivalence ratio of 0.38. Continuous TOC measurement allowed understanding the evolution of the gasification process and the relation between a higher production of TOC and CO as the gasification temperature raised.
Developing a Novel Index for Assessing and Managing the Contribution of Sustainable Campuses to Achieve UN SDGs
Authors: Alawneh Rami , Jannoud Ismael , Rabayah Hesham , Ali Hikmat
Published: October 2021

Sustainable campuses have a substantial role to play in achieving the Sustainable Development Goals (SDGs). Worldwide, there are many rating schemes to assess universities’ sustainability; UI GreenMetric is one of the most common global rating schemes aimed at encouraging green campuses and university sustainability worldwide. However, none of the existing rating schemes quantitatively measure the contributions of the implementation of its assessment indicators to achieve SDGs. There is a shortage of information on how sustainable campuses contribute to achieving SDGs. Thus, this research aimed to develop a novel index to assess and manage the contributions of sustainable campuses certified by UI GreenMetric to achieve SDGs. This article proposes novel indices, the GreenMetric Indicator Contribution Index (GMICI) and the GreenMetric Sustainable Campus Index (GMSCI), to evaluate the contributions of implementing UI GreenMetric indicators for achieving the SDGs. By implementing questionnaire surveys, we collected the relevant data. Structured questionnaire surveys yielded 35 responses from experts. The contributions of UI GreenMetric indicators to achieving SDGs were evaluated using the Relative Importance Index (RII). The results indicated an important relationship between the GreenMetric indicator and SDGs 3, 4, 6, 7, 8, 9,11, 12, 13 and 15. This research concludes that the proposed GMICI and GMSCI are a rigorous means for evaluating the contribution of UI GreenMetric indicators to UN-SDGs’ achievement.
Exploring the Joint Impacts of Natural and Built Environments on PM2.5 Concentrations and Their Spatial Heterogeneity in the Context of High-Density Chinese Cities
Authors: Duan Shanyou , Liu Qian , Jiang Dumei , Jiang Yulin , Lin Yinzhi , Gong Ziying
Published: October 2021

Air pollution in China has attracted wide interest from the public and academic communities. PM2.5 is the primary air pollutant across China. PM2.5 mainly comes from human activities, and the natural environment and urban built environment affect its distribution and diffusion. In contrast to American and European cities, Chinese cities are much denser, and studies on the relationships between urban form and air quality in high-density Chinese cities are still limited. In this paper, we used the ordinary least square (OLS) and geographical weighted regression (GWR) models, selected an already high-density city, Shenzhen, as the study area, and explored the effects of the natural and built environments on air pollution. The results showed that temperature always had a positive influence on PM2.5 and wind speed had a varied impact on PM2.5 within the city. Based on the natural factors analysis, the paper found that an increase in the floor area ratio (FAR) and road density may have caused the increase in the PM2.5 concentration in the central city. In terms of land use mix, land use policies should be adopted separately in the central city and suburban areas. Finally, in terms of spatial heterogeneity, the GWR models achieved much better performances than the global multivariate regression models, with lower AICc and RMSE values and higher adjusted R2 values, ultimately explaining 60% of the variance across different city areas. The results indicated that policies and interventions should be more targeted to improve the air environment and reduce personal exposure according to the spatial geographical context.
Robust Design of Power System Stabilizers Using Improved Harris Hawk Optimizer for Interconnected Power System
Authors: Chaib Lakhdar , Choucha Abdelghani , Arif Salem , Zaini Hatim G. , El-Fergany Attia , Ghoneim Sherif S. M.
Published: October 2021

In this present work, a new metaheuristic method called a Harris hawk optimizer (HHO) is applied to achieve the optimal design of a power system stabilizer (PSS) in a multimachine power system. Several well-known chaos maps are incorporated into the HHO to form a chaotic HHO (CHHO) with the aim of improving static operators and enhancing global searching. To assess the CHHO performance, exhaustive comparison studies are made between anticipated chaotic maps in handling unconstrained mathematical problems. At this moment, The PSS design problem over a wide permutation of loading conditions is formulated as a non-linear optimization problem. The adopted objective function defines the damping ratio of lightly damped electromechanical modes subject to a set of constraints. The best PSS parameters are generated by the proposed CHHO. The applicability of the proposed CHHO based on PSS is examined and demonstrated on a 10-generator and 39-bus multimachine power system model. The performance assessments of the CHHO results are realized by a comparative study with HHO through extensive simulations along with further eigenvalue analysis to prove its efficacy. The simulation results convincingly demonstrate the high performance of the proposed CHHO-PSS under various operating scenarios.
Evaluation Model for Sustainable Development of Settlement System
Authors: Harbiankova Alena , Scherbina Elena
Published: October 2021

Sustainability of settlement systems is of greatest relevance in political and socio-economic stability all over the world. The development effectiveness of a rural settlement system involves the solution of a number of matters in sustainable development, namely social welfare and environmental balance, economy and industry development, improving the pipeline and utility infrastructure, and improving the efficiency of the decision-making process. Currently, the sustainability of a rural settlement system is one of the key objectives in regional planning in post-Soviet countries. The introduction of new tools for assessing and managing the settlement system development is particularly true for Belarus, as a country with a strong focus on agricultural industry. The research aim was to develop and approve a model for evaluating the settlement system development. The research methods were based on the complex and interdisciplinary approaches, namely the system-element approach, the comparative analysis, spatial and mathematical modelling, factor analysis, and the cartographic analysis. The model was approved by practical consideration for evaluating the development of the analogue object at the local planning level. The practical relevance of the research is associated with the potential for using the model as a significant tool in land use planning. The model employs both quantitative and qualitative evaluation to obtain alternative solutions towards sustainable development of rural areas. Another advantage of the model is its multifunctionality, which enables: (1) sustainability evaluation of a settlement system, (2) establishment of regional planning priority areas, and (3) development of specific measures for ensuring the sustainability of a regional settlement system and its elements.
Advanced Warning System to Improve Safety at Train Grade Crossings
Authors: Haces-Garcia Joaquin , Haces-Garcia Arturo , Haces-Garcia Francisco , Haces-Fernandez Francisco
Published: October 2021

The severity of traffic accidents at train grade crossings has led to efforts in mitigating their potential damaging effects. Over the last 45 years, significant investment has been made at these crossings in the United States to reduce the number of accidents. Initially, these improvements reduced accidents, but in the last decade, the numbers have plateaued, even as additional safety investment has continued. Geospatial data from the Federal Railroad Administration was evaluated to ascertain the causes of the efficacy reduction of traditional safety measures. Temporal patterns were detected in diverse parameters that measure accident seriousness such as their frequency, financial damages, injuries, and deaths. An advanced warning system for motorist was proposed in this research to allow them enough time to change their schedules and driving routes, avoiding blockages caused by incoming trains. To avoid pitfalls from previous proposed systems the model will be initially implemented in locations with a high number of accidents and lower layout complexity for the railway, roads, and train grade crossings. Two railways in Texas were selected for the initial implementation of the system. The proposed pilot locations showed high potential for the development of the advanced warning system, in preparation for a broader effort to continue the improvement in safety at railway crossings.
Enhanced Subcontractors Allocation for Apartment Construction Project Applying Conceptual 4D Digital Twin Framework
Authors: Kim Woong-Gi , Ham Namhyuk , Kim Jae-Jun
Published: October 2021

The problem of optimal allocation of resources in limited circumstances to handle assigned tasks has been dealt with in a wide variety of research fields. Various research methodologies have been proposed to address uncertainties such as waiting and waste in construction projects, but they do not take into account the complexity of construction production systems. In this study, a research approach was proposed that simplified the construction production system into a work package to be serviced and a work group to provide services. In addition, a conceptual 4D digital twin framework considering the uncertainty of the construction production system was proposed. This framework includes BIM as an information model and a queuing model as a decision-making model. Through case projects, we have presented how this framework can be used for decision making in several statuses. As a result of the analysis using the performance index of the queuing model, it was possible to monitor the status of the system according to the allocation of resources. In addition, it was possible to confirm the improvement of the performance index according to the additional arrangement of the work group and the activity cycle of the work package. The framework presented in this study helps to quantitatively analyze the state of the system according to the input data based on empirical knowledge, but it has a limitation in that it cannot present an optimized resource allocation solution. Therefore, in future research, it is necessary to consider the grafting of machine learning technology that can provide optimal solutions by solving complex decision-making problems.
Exploring the Institutional and Bottom-Up Actions for Urban Air Quality Improvement: Case Studies in Antwerp and Gdańsk
Authors: Badach Joanna , Dymnicka Małgorzata , Załęcki Jarosław , Brosz Maciej , Voordeckers Dimitri , Van Acker Maarten
Published: October 2021

The article presents the results of qualitative studies concerning the presence of air quality management in the process of urban planning and in the public discourse in Antwerp, Belgium, and Gdańsk, Poland. We focused on the way urban planners, environmental experts, and stakeholders perceive the problem of air pollution, especially with respect to urban development policy, and whether they consider it one of the major factors determining the quality of the urban built environment. The analysis was empirically based on free, partially structured interviews with experts. With that aim, we referred to certain assumptions of the multidimensional concept of environmental protection and integrated urban planning, highlighting the knowledge gained through interview analysis, literature review, and comparative case study research. The approach brings to light the difference between the perceived and measured air quality and to what extent it is affected by the spatial conditions. The research reveals how the range of perceptions of air pollution is embedded in several sociological, urban planning, and cultural perspectives and how these perceptions differ between the different profiles of the stakeholders and experts.
The 1+5 Architectural Views Model in Designing Blockchain and IT System Integration Solutions
Authors: Górski Tomasz
Published: October 2021

Service fulfillment for clients increasingly involves cooperation between information technology (IT) systems. Designing such solutions requires an architectural approach that ensures symmetry between the communicating parties. For the design of such systems, the author introduces the 1+5 architectural views model. The model contains three new architectural views. For business process modeling, it ensures the integrated processes view. Integration aspects cover two additional views: integrated services, and contracts. Moreover, new stereotypes and tagged values have been added to the unified modeling language (UML). The author has introduced two profiles: UML profile for integration flows, and UML profile for distributed ledger deployment. Communication between systems requires flows that arrange mediation mechanisms. The paper describes an integration flow diagram that extends a UML activity diagram. In the case of blockchain, the author has proposed the smart contract design pattern. The paper describes three case studies that have employed the model to design various solutions. The 1+5 model has proven to be well suited for designing both centralized integration environments with enterprise service bus (ESB) and distributed blockchain solutions with peer-to-peer (P2P) connections.
A Composite Initialization Method for Phase Retrieval
Authors: Luo Qi , Lin Shijian , Wang Hongxia
Published: October 2021

Phase retrieval is a classical inverse problem with respect to recovering a signal from a system of phaseless constraints. Many recently proposed methods for phase retrieval such as PhaseMax and gradient-descent algorithms enjoy benign theoretical guarantees on the condition that an elaborate estimate of true solution is provided. Current initialization methods do not perform well when number of measurements are low, which deteriorates the success rate of current phase retrieval methods. We propose a new initialization method that can obtain an estimate of the original signal with uniformly higher accuracy which combines the advantages of the null vector method and maximal correlation method. The constructed spectral matrix for the proposed initialization method has a simple and symmetrical form. A lower error bound is proved theoretically as well as verified numerically.
Weak Feature Extraction of Local Gear Damage Based on Underdamped Asymmetric Periodic Potential Stochastic Resonance
Authors: Hu Bingbing , Zhang Shuai , Peng Ming , Liu Jie , Liu Shanhui , Zhang Chunlin
Published: October 2021

The enhancement of the detection of weak signals against a strong noise background is a key problem in local gear fault diagnosis. Because the periodic impact signal generated by local gear damage is often modulated by high-frequency components, fault information is submerged in its envelope signal when demodulating the fault signal. However, the traditional bistable stochastic resonance (BSR) system cannot accurately match the asymmetric characteristics of the envelope signal because of its symmetrical potential well, which weakens the detection performance for weak faults. In order to overcome this problem, a novel method based on underdamped asymmetric periodic potential stochastic resonance (UAPPSR) is proposed to enhance the weak feature extraction of the local gear damage. The main advantage of this method is that it can better match the characteristics of the envelope signal by using the asymmetry of its potential well in the UAPPSR system and it can effectively enhance the extraction effect of periodic impact signals. Furthermore, the proposed method enjoys a good anti-noise capability and robustness and can strengthen weak fault characteristics under different noise levels. Thirdly, by reasonably adjusting the system parameters of the UAPPSR, the effective detection of input signals with different frequencies can be realized. Numerical simulations and experimental tests are performed on a gear with a local root crack, and the vibration signals are analyzed to validate the effectiveness of the proposed method. The comparison results show that the proposed method possesses a better resonance output effect and is more suitable for weak fault feature extraction under a strong noise background.
Rough q-Rung Orthopair Fuzzy Sets and Their Applications in Decision-Making
Authors: Bilal Muhammad Asim , Shabir Muhammad , Al-Kenani Ahmad N.
Published: October 2021

Yager recently introduced the q-rung orthopair fuzzy set to accommodate uncertainty in decision-making problems. A binary relation over dual universes has a vital role in mathematics and information sciences. During this work, we defined upper approximations and lower approximations of q-rung orthopair fuzzy sets using crisp binary relations with regard to the aftersets and foresets. We used an accuracy measure of a q-rung orthopair fuzzy set to search out the accuracy of a q-rung orthopair fuzzy set, and we defined two types of q-rung orthopair fuzzy topologies induced by reflexive relations. The novel concept of a rough q-rung orthopair fuzzy set over dual universes is more flexible when debating the symmetry between two or more objects that are better than the prevailing notion of a rough Pythagorean fuzzy set, as well as rough intuitionistic fuzzy sets. Furthermore, using the score function of q-rung orthopair fuzzy sets, a practical approach was introduced to research the symmetry of the optimal decision and, therefore, the ranking of feasible alternatives. Multiple criteria decision making (MCDM) methods for q-rung orthopair fuzzy sets cannot solve problems when an individual is faced with the symmetry of a two-sided matching MCDM problem. This new approach solves the matter more accurately. The devised approach is new within the literature. In this method, the main focus is on ranking and selecting the alternative from a collection of feasible alternatives, reckoning for the symmetry of the two-sided matching of alternatives, and providing a solution based on the ranking of alternatives for an issue containing conflicting criteria, to assist the decision-maker in a final decision.
Certain Finite Integrals Related to the Products of Special Functions
Authors: Kumar Dinesh , Ayant Frédéric , Asawasamrit Suphawat , Tariboon Jessada
Published: October 2021

The aim of this paper is to establish a theorem associated with the product of the Aleph-function, the multivariable Aleph-function, and the general class of polynomials. The results of this theorem are unified in nature and provide a very large number of analogous results (new or known) involving simpler special functions and polynomials (of one or several variables) as special cases. The derived results lead to significant applications in physics and engineering sciences.
Delay Differential Equations of Fourth-Order: Oscillation and Asymptotic Properties of Solutions
Authors: Bazighifan Omar , Al-Kandari Maryam , Al-Ghafri Khalil S. , Ghanim F. , Askar Sameh , Oros Georgia Irina
Published: October 2021

In this work, by using the comparison method and Riccati transformation, we obtain some oscillation criteria of solutions of delay differential equations of fourth-order in canonical form. These criteria complement those results in the literature. We give two examples to illustrate the main results. Symmetry plays an essential role in determining the correct methods for solutions to differential equations.
Using Shapley Values and Genetic Algorithms to Solve Multiobjective Optimization Problems
Authors: Wu Hsien-Chung
Published: October 2021

This paper proposes a new methodology to solve multiobjective optimization problems by invoking genetic algorithms and the concept of the Shapley values of cooperative games. It is well known that the Pareto-optimal solutions of multiobjective optimization problems can be obtained by solving the corresponding weighting problems that are formulated by assigning some suitable weights to the objective functions. In this paper, we formulated a cooperative game from the original multiobjective optimization problem by regarding the objective functions as the corresponding players. The payoff function of this formulated cooperative game involves the symmetric concept, which means that the payoff function only depends on the number of players in a coalition and is independent of the role of players in this coalition. In this case, we can reasonably set up the weights as the corresponding Shapley values of this formulated cooperative game. Under these settings, we can obtain the so-called Shapley–Pareto-optimal solution. In order to choose the best Shapley–Pareto-optimal solution, we used genetic algorithms by setting a reasonable fitness function.
Protective Effects of the Hydroethanolic Extract of Fridericia chica on Undifferentiated Human Neuroblastoma Cells Exposed to α-Zearalenol (α-ZEL) and β-Zearalenol (β-ZEL)
Authors: Alvarez-Ortega Neda , Caballero-Gallardo Karina , Taboada-Alquerque María , Franco Jackeline , Stashenko Elena E. , Juan Cristina , Juan-García Ana , Olivero-Verbel Jesus
Published: October 2021

Fridericia chica (Bignoniaceae) is a traditional medicinal plant. The aim of this research was to determine the protective effects of the hydroethanolic extract from the F. chica leaves (HEFc) against the cytotoxicity of zearalenone (α-ZEL) and β-ZEL on SH-SY5Y cells. Free radical scavenging activity of HEFc was evaluated using the DPPH method. The cytotoxicity of both zearalenone metabolites and HEFc was examined using MTT test, as was the cytoprotective effects of the HEFc on cells treated with these mycotoxins. The chemical composition of HEFc was determined using UPLC-QTOF-MS/MS. HEFc elicited good DPPH radical scavenging activity following a concentration-dependent relationship. Cells exposed to α-ZEL exhibited a viability ˂50% after 48 h of treatment (25 and 50 µM), while those exposed to β-ZEL showed viability ˂50% (100 µM) and ˂25% (25-100 µM) after 24 and 48 h of exposure, respectively. HEFc showed a significant increase in cell viability after exposure to α-ZEL (25 and 50 µM) and β-ZEL (6–100 µM) (p < 0.05). UPLC-QTOF-MS/MS analyses allowed the identification of 10 phytochemical components in the HEFc. In short, the hydroethanolic extract of F. chica grown in Colombian Caribbean can protect against the effects of mycotoxins and it is a valuable source of compounds with antioxidant properties.
Biomarkers of Deoxynivalenol, Citrinin, Ochratoxin A and Zearalenone in Pigs after Exposure to Naturally Contaminated Feed Close to Guidance Values
Authors: Tkaczyk Agnieszka , Jedziniak Piotr , Zielonka Łukasz , Dąbrowski Michał , Ochodzki Piotr , Rudawska Adrianna
Published: October 2021

This study applied multi-mycotoxin liquid chromatography with tandem mass spectrometric detection (LC-MS/MS) methods to determine the biomarkers of exposure in urine and serum samples from a dose-response study with pigs. The 24 studied pigs were divided into three groups: a control and two experimental ones (with different levels of feed contamination). They were exposed to feed prepared from cereals contaminated with deoxynivalenol (DON), zearalenone (ZEN), ochratoxin A (OTA) and citrinin (CIT) for 14 days. After that, both experimental groups received the same feed as the control group for the next 14 days to determine the kinetics of the disappearance of mycotoxin biomarkers. Urine samples were collected daily in the morning and blood samples—eight-times during the experiment. The study reported herein was the first prolonged exposure experiment for multiple mycotoxins like OTA and CIT in pigs. The urinary and serum levels of all biomarkers correlated well with the respective toxin intake; thereby demonstrating that they are suitable biomarkers of exposure in pigs. Urine is a good candidate to monitor DON, ZEN, OTA, CIT exposure while serum may be used to monitor DON, OTA and CIT. Additionally, OTA has even been quantified in both matrices in the experimental groups two weeks after changing the contaminated feed back to the control, this result differed from those produced by the other mycotoxins which were only quantified during the first two weeks. Therefore both matrices are suitable candidates to monitor prolonged OTA exposure in pigs.
Botulinum Neurotoxins in Central Nervous System: An Overview from Animal Models to Human Therapy
Authors: Luvisetto Siro
Published: October 2021

Botulinum neurotoxins (BoNTs) are potent inhibitors of synaptic vesicle fusion and transmitter release. The natural target of BoNTs is the peripheral neuromuscular junction (NMJ) where, by blocking the release of acetylcholine (ACh), they functionally denervate muscles and alter muscle tone. This leads them to be an excellent drug for the therapy of muscle hyperactivity disorders, such as dystonia, spasticity, and many other movement disorders. BoNTs are also effective in inhibiting both the release of ACh at sites other than NMJ and the release of neurotransmitters other than ACh. Furthermore, much evidence shows that BoNTs can act not only on the peripheral nervous system (PNS), but also on the central nervous system (CNS). Under this view, central changes may result either from sensory input from the PNS, from retrograde transport of BoNTs, or from direct injection of BoNTs into the CNS. The aim of this review is to give an update on available data, both from animal models or human studies, which suggest or confirm central alterations induced by peripheral or central BoNTs treatment. The data will be discussed with particular attention to the possible therapeutic applications to pathological conditions and degenerative diseases of the CNS.
Antifungal Activity of Biocontrol Agents In Vitro and Potential Application to Reduce Mycotoxins (Aflatoxin B1 and Ochratoxin A)
Authors: Illueca Francisco , Vila-Donat Pilar , Calpe Jorge , Luz Carlos , Meca Giuseppe , Quiles Juan M.
Published: October 2021

Food bio-preservatives are requested as substituents of chemical pesticides in food. The aim of this study was to carry out a screening of twenty biocontrol agents (BCAs) for their potential fungicidal activity in vitro. Twenty BCAs were tested against ten pathogenic fungi. Some of the cell-free supernatants (CFS) tested showed in vitro antifungal activity versus pathogenic fungi. The highest fungicidal activity was observed in the fermented CFS of Paenibacillus chibensis CECT 375, Bacillus amyloliquefaciens CECT 493, and Pantoea agglomerans CECT 850, which showed a minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values of 125 and 250 g/L, respectively. The compounds responsible for the antifungal activity, such as organic and phenolic acids, were determined. Lactic acid, acetic acid, benzoic acid, and phenyllactic acid among others can be related to antifungal activity. HPLC-MS/MS analysis showed a reduction of ochratoxin A (OTA) and aflatoxin B1 (AFB1) up to 26% (Paenibacillus alvei CECT 2) and 55% (Paenibacillus polymyxa CECT 155), respectively. The present study prompts that metabolism products of BCAs are propitious for the bioconservation of food, due to their ability to reduce the proliferation of mycotoxigenic fungi and mycotoxins production.
Twenty-Five Years of Domoic Acid Monitoring in Galicia (NW Spain): Spatial, Temporal and Interspecific Variations
Authors: Blanco Juan , Moroño Ángeles , Arévalo Fabiola , Correa Jorge , Salgado Covadonga , Rossignoli Araceli E. , Lamas J. Pablo
Published: October 2021

Prevalence, impact on shellfish resources and interspecific, spatial, and temporal variabilities of domoic acid (DA) in bivalves from Galicia (NW Spain) have been studied based on more than 25 years of monitoring data. The maximum prevalence (samples in which DA was detected) (100%) and incidence (samples with DA levels above the regulatory limit) (97.4%) were recorded in Pecten maximus, and the minimum ones in Mytilus galloprovincialis (12.6 and 1.1%, respectively). The maximum DA concentrations were 663.9 mg kg−1 in P. maximus and 316 mg kg−1 in Venerupis corrugata. After excluding scallop P. maximus data, DA was found (prevalence) in 13.3% of bivalve samples, with 1.3% being over the regulatory limit. In general, the prevalence of this toxin decreased towards the North but not the magnitude of its episodes. The seasonal distribution was characterized by two maxima, in spring and autumn, with the later decreasing in intensity towards the north. DA levels decreased slightly over the studied period, although this decreasing trend was not linear. A cyclic pattern was observed in the interannual variability, with cycles of 4 and 11 years. Intoxication and detoxification rates were slower than those expected from laboratory experiments, suggesting the supply of DA during these phases plays an important role.