bluuebunny/crossref_metadata_2025 huggingface dataset:
Hexagonal Stimulation Digital Controller Design and Verification for Wireless Subretinal Implant Device
Authors: Abbasi Wajahat , Choi Hojong , Kim Jungsuk
Published: April 2022

Significant progress has been made in the field of micro/nano-retinal implant technologies. However, the high pixel range, power leakage, reliability, and lifespan of retinal implants are still questionable. Active implantable devices are safe, cost-effective, and reliable. Although a device that can meet basic safety requirements set by the Food and Drug Administration and the European Union is reliable for long-term use and provides control on current and voltage parameters, it will be expensive and cannot be commercially successful. This study proposes an economical, fully controllable, and configurable wireless communication system based on field-programmable gated arrays (FPGAs) that were designed with the ability to cope with the issues that arise in retinal implantation. This system incorporates hexagonal biphasic stimulation pulses generated by a digital controller that can be fully controlled using an external transmitter. The integration of two separate domain analog systems and a digital controller based on FPGAs is proposed in this study. The system was also implemented on a microchip and verified using in vitro results.
Validation of Continuous Monitoring System for Epileptic Users in Outpatient Settings
Authors: Zambrana-Vinaroz David , Vicente-Samper Jose Maria , Sabater-Navarro Jose Maria
Published: April 2022

Epilepsy is a chronic disease with a significant social impact, given that the patients and their families often live conditioned by the possibility of an epileptic seizure and its possible consequences, such as accidents, injuries, or even sudden unexplained death. In this context, ambulatory monitoring allows the collection of biomedical data about the patients’ health, thus gaining more knowledge about the physiological state and daily activities of each patient in a more personalized manner. For this reason, this article proposes a novel monitoring system composed of different sensors capable of synchronously recording electrocardiogram (ECG), photoplethysmogram (PPG), and ear electroencephalogram (EEG) signals and storing them for further processing and analysis in a microSD card. This system can be used in a static and/or ambulatory way, providing information about the health state through features extracted from the ear EEG signal and the calculation of the heart rate variability (HRV) and pulse travel time (PTT). The different applied processing techniques to improve the quality of these signals are described in this work. A novel algorithm used to compute HRV and PTT robustly and accurately in ambulatory settings is also described. The developed device has also been validated and compared with other commercial systems obtaining similar results. In this way, based on the quality of the obtained signals and the low variability of the computed parameters, even in ambulatory conditions, the developed device can potentially serve as a support tool for clinical decision-taking stages.
Study of the Two-Line Element Accuracy by 1U CubeSat with a GPS Receiver
Authors: Kovář Pavel , Puričer Pavel , Kovářová Kateřina
Published: April 2022

There is a common practice to calculate orbital trajectories of space objects like satellites and space debris using Two-Line Element Sets (TLEs). However, TLEs provide rather coarse parameters for fine orbit computation and their precision varies with age of their issue and position of the satellite. The paper evaluates such induced position determination error using the comparison of a position calculated from TLE data for a small CubeSat class satellite and a position obtained from the on-board custom GPS receiver that is a part of such satellite payload. The analyses of the impact of satellite position at the orbit, i.e., a dependency of position error on satellite geographical latitude, and impact of the ageing of TLE data in frame of position and velocity vector were made. There was shown that use of TLE data can bring some significant errors in calculation of predicted satellite position which can affect performance and efficiency of some related tasks like steering the ground station antenna for communication with the satellite or planning the satellites operations namely for the classes of small and amateur satellites.
Phase Unwrapping and Frequency Points Subdivision of the Frequency Sweeping Interferometry Based Absolute Ranging System
Authors: Song Luming , Shi Guang , Liu Hong , Lin Hongyi , Zhang Fumin , Sun Dong
Published: April 2022

Frequency sweeping interferometry (FSI) based absolute distance ranging has high precision and no ranging blind area. It can be used to realize large-scale and non-cooperative target measurement. However, the nonlinear frequency modulation of the laser seriously affects the ranging accuracy. In this manuscript, a measurement method assisted by Hilbert Transform (HT) and Chirp-z Transform (CZT) is proposed, which can realize the phase unwrapping of the beat signal, the length reduction in the delay fiber of auxiliary optical path, and the improvement of the frequency resolution. The narrow-band frequency suitable for HT is further studied. In the experiment, the ranging resolution is 70 μm and the standard deviation is 12.6 μm within a distance of 4005 mm.
Revolutionary Love: Early Childhood Education as Counter-Culture
Authors: Taggart Geoff
Published: April 2022

This paper places the pedagogies of love and care which typify the early years of practice in the context of evolution, arguing that, during an optimum window of development, young children are predisposed physiologically to benefit from the attention of multiple alloparents. This anthropological model of community stands in stark contrast to the individualistic and privatised notion of love in neoliberal cultures, indicating reasons why practitioners may be ambivalent about it. Moreover, it is argued that, whilst the notion of care is easily commoditised, the deeper concept of love, contextualised within wisdom and faith paths, is resistant to the money culture. In looking beyond neoliberalism at counter-cultural alternatives, alloparenting traditions suggest a way in which ECEC settings can establish themselves as models of social sustainability rooted in ‘philia’ and mutuality.
Effects of Organic Amendments on Soil Aggregate Stability, Carbon Sequestration, and Energy Use Efficiency in Wetland Paddy Cultivation
Authors: Rahman Mohammad Mizanur , Kamal Mohammed Zia Uddin , Ranamukhaarachchi Senaratne , Alam Mohammad Saiful , Alam Mohammad Khairul , Khan Mohammad Arifur Rahman , Islam Mohammad Moshiul , Alam Mohammad Ashraful , Jiban Saidul Islam , Mamun Mohammad Abdullah Al , Abdullah Hasan Muhammad , Biswas Jatish Chandra , Akhter Sohela , Naher Umme Aminun , Maniruzzaman Md. , Haque Mohammad Mozammel , Ahmed Faruque
Published: April 2022

A study was conducted to assess the effects of organic amendments on soil aggregates, carbon (C) sequestration, and energy use efficiency (EUE) during five consecutive Boro and Transplanted Aman rice seasons in Bangladesh during 2018–2020. Five treatments (viz., control (only inorganic fertilizers), cow dung (CD), vermicompost (VC), rice straw (RS), and poultry manure (PM)) were used. The organic materials were applied at 2 t C ha−1 season−1 to all the plots, except in the control treatment. Inorganic fertilizers were applied in all treatments in both seasons following integrated nutrient management (INM). The data reveal that PM was found to be more efficient at increasing the water-stable soil aggregates (WSA), followed by the RS, CD, and VC. The WSA in smaller-sized soil aggregates were found to be higher than those in larger-sized soil aggregates. VC was found to be the most effective in terms of C sequestration (29%), followed by PM (26%), CD (22%), and RS (20%). The highest EUE was attributed to the control treatment (9.77), followed by the CD (8.67), VC (8.04), RS (2.10), and PM (1.18), which showed energy wastage in the organic treatments. The system productivity (SP) followed the opposite trend of the EUE. The INM is a better approach to improve the soil health, the C sequestration, and the SP, but it appeared as an energy-inefficient strategy, which suggests that a balanced application of organic and inorganic nutrients is needed in order to achieve yield sustainability and EUE.
Explaining Resistance to the COVID-19 Preventive Measures: A Psychological Reactance Perspective
Authors: Bokhari Rabia , Shahzad Khurram
Published: April 2022

This paper examines the impact that psychological reactance has on the COVID-19 adherence-related behavior and vaccine motivations of the residents of Saudi Arabia. A cross-sectional, online survey was administered, and 604 usable responses were analyzed to discover the level of psychological reactance, and its impact on adherence to COVID-19 preventive measures and vaccine intentions. Results of the Kruskal–Wallis H test demonstrated statistically significant evidence (p < 0.05) of differences between the mean ranks for four out of seven key COVID-19 preventive measures studied, and four out of five items related to vaccine motivations, as a result of psychological reactance. These results suggest that while the majority of the population is adhering to COVID-19 preventive measures, for the subset of the population that are not fully compliant, psychological reactance is a significant factor in influencing behavior. Governments are, therefore, recommended to ensure that their public health messages are autonomy supporting, and take into consideration psychological and personality-based differences in individuals.
A Strategy for Managing the Operation of Technical Infrastructure Based on the Analysis of “Bad Actors”—A Case Study of LOTOS Group S.A.
Authors: Dziabas Tomasz , Deja Mariusz , Wiśniewska Aleksandra
Published: April 2022

The article covers issues related to the selection of a management strategy for the operation of technical infrastructure. It contains the approaches, methodology and a general model of the system of operation of the Maintenance Services of the LOTOS Group production company, which is an example of a large oil concern. Nowadays, an increasing aspect is put on the efficiency of individual repair processes, as well as the operation of equipment. Doubts often arise as to which strategy is the right one and which one to choose. With numerous machines, there are problems related to work planning and optimal use of resources. In addition, there are frequently difficulties in identifying the devices that interfere with the processes. The aim of this article is to present the maintenance strategy of the LOTOS production company and to introduce a procedure that allows for the assessment of the efficiency of machinery and equipment operation. It includes a method extending the identification of “Bad Actors” used so far, based on data from the ERP (Enterprise Resource Planning) system, with a solution based on reports made after device repairs. MTBR (Mean Time Between Repair) coefficients were calculated for particular Complexes, Plants and Machines, which allowed for the identification of troublesome areas and the most difficult devices in production processes. This made it possible to select the equipment that should be repaired in the first place. After the implementation of the method and service activities, a decrease in the number of problematic machines was observed.
Interplay of Water–Energy Security and Food Consumption Patterns towards Achieving Nutrition Security in Katsina State, North-Western Nigeria
Authors: Sani Yahaya , Scholz Miklas
Published: April 2022

Everyone has the right to secure water, energy, and food supplies. These essential resources are stressed in many countries. With the current population growth rate and urbanisation, especially in sub-Saharan Africa, there is a need for more food, water, and energy to sustain the increasing population. The aim of this study was to assess the inter-relationship among water and energy in various urban and rural households to support food and nutrition security. Considering the social-economic peculiarities of the region, a specific framework and questionnaire were developed for the study. A survey involving 1785 questionnaires was conducted. Urban and rural stratification methods were used in selecting settlements across the regions. The household’s nutritional status was measured in relation to protein-rich foods as well as vegetable and fruit consumption. In addition to the Person’s correlation coefficient, which was applied to measure the association between two categories of food consumption, the chi-squared test of interdependence to determine the effect of the urban–rural dichotomy on resource utilisation was calculated. The findings indicate a high risk of undernourishment associated with insufficient sources of water and energy, as well as inappropriate sanitation facilities, especially in rural communities.
The Information Spillover among the Carbon Market, Energy Market, and Stock Market: A Case Study of China’s Pilot Carbon Markets
Authors: Yao Yi , Tian Lixin , Cao Guangxi
Published: April 2022

The carbon emission trading market is an important policy tool to promote the realization of China’s carbon peaking and carbon neutrality goals. Research on the relationship between the carbon market and other related ones supports policy formulation and risk aversion. Firstly, we construct the Carbon–Energy–Stock system to compare the information spillover between the three subsystems under a unified framework. Secondly, we adopt the connectedness network to identify the role and status of the carbon, energy, and stock markets. Thirdly, through the rolling window approach, we explore the dynamic evolution of the information spillover. The results show that (1) the information spillover effect between China’s pilot carbon markets, the energy market, and the stock market is relatively low; (2) in the Carbon–Energy–Stock system, China’s pilot carbon markets behave as the information transmitters, and the Guangdong pilot and Beijing pilot are core pilots. The coal market is the top information recipient, while the new energy industry is the top information transmitter; (3) the system connectivity shows the characteristics of increasing first and then decreasing. For investors and policymakers, looking at each market from a systems point of view will present a more accurate understanding of them and their interconnections.
Levels of Transformation in Sustainable Curricula: The Case of Geography Education
Authors: Granados-Sánchez Jesús
Published: April 2022

The 17 United Nations Sustainable Development Goals (SDGs) adopted in 2015 have created renewed interest in sustainability in education. Geography education is a discipline that studies most of the issues related to the SDGs and has a significant role to play in the Anthropocene. Current debates on curricular sustainability and geography education suggest that geography educators are integrating sustainability in different ways but not all approaches have the same transformative impact. The aim of this study is to provide a theoretical model that determines different levels of transformation that could be helpful for advancing in curricular sustainability in geography education. The proposed model is called The Transformative Sustainable Curricula (TSC) model. Its development has relied on two processes that have involved, at the same time, two different methodologies: the creation of the model through documentary analysis, and its validation from interviews with experts in education for sustainability and geography education. The model is structured in three levels or stages: adaptation, reform and transformation. Each level has been characterized according to the following elements: the perspectives of sustainable development; the type of sustainable education; transformative learning; ecology of knowledge; institutional integration; context, change and community. The proposal makes teachers aware of where their teaching practice is located and how to move forward. It is also useful to determine what elements constitute a prop for sustainability and how these can guide educators and scholars in scaling vertically and horizontally their contribution towards a geographic education that is more sustainable and transformative, should they wish to do so.
Higher Education for Sustainability: A Bibliometric Approach—What, Where and Who Is Doing Research in This Subject?
Authors: Machado Carolina Feliciana , Davim João Paulo
Published: April 2022

Contextualization: From a very early age, assuming more prominence over the last decades, issues related to sustainability have been taking on a particular interest in the field of research. Although initially the basic concern was at the level of environmental sustainability, the truth is that, progressively, education for sustainability, deeply linked to the science of sustainability, constitutes, together with the latter, the scientific basis for education for the sustainability in higher education, thus emerging a research niche capable of providing greater openness and interaction between higher education institutions and their surroundings. Main aims of the study: Due to the importance that this issue assumes, this article seeks to address the issue of sustainability in higher education, giving particular focus to the analysis at the level of studies that have been developed, which are the main countries and institutions where this has been most researched, as well as which main researchers have been working on this issue. Methodology: For this purpose, and using information taken from the Scopus Database, a bibliometric analysis was carried out, which based on the items “higher education” and “sustainability” allowed to identify a set of 4410 publications. Main results: The results obtained allow to conclude that the number of publications in this area has been observing a significant increase over the last 30 years, with the United States, UK, Spain, Australia and Germany emerging as the countries which publish the most, and within these the Leuphana Universitat Luneburg, RMIT, Hochschule fur Angewandte Wissenschaften Hamburg, Manchester Metropolitan and the Arizona State universities that most publish in this field of research. The five main researchers in the field of higher education for sustainability, were also highlighted. Main contributions: Theoretical and practical contributions were highlighgted, namely, the contribution for government entities and the respective HEIs to reflect on the possible synergies to be developed, as well as to establish strategies and policies promoters of a more efficient and effective investment in research in higher education for sustainability.
Urban Flood-Risk Assessment: Integration of Decision-Making and Machine Learning
Authors: Taromideh Fereshteh , Fazloula Ramin , Choubin Bahram , Emadi Alireza , Berndtsson Ronny
Published: April 2022

Urban flood-risk mapping is an important tool for the mitigation of flooding in view of continuing urbanization and climate change. However, many developing countries lack sufficiently detailed data to produce reliable risk maps with existing methods. Thus, improved methods are needed that can help managers and decision makers to combine existing data with more soft semi-subjective data, such as citizen observations of flood-prone and vulnerable areas in view of existing settlements. Thus, we present an innovative approach using the semi-subjective Analytic Hierarchy Process (AHP), which integrates both subjective and objective assessments, to help organize the problem framework. This approach involves measuring the consistency of decision makers’ judgments, generating pairwise comparisons for choosing a solution, and considering criteria and sub-criteria to evaluate possible options. An urban flood-risk map was created according to the vulnerabilities and hazards of different urban areas using classification and regression-tree models, and the map can serve both as a first stage in advancing flood-risk mitigation approaches and in allocating warning and forecasting systems. The findings show that machine-learning methods are efficient in urban flood zoning. Using the city Rasht in Iran, it is shown that distance to rivers, urban drainage density, and distance to vulnerable areas are the most significant parameters that influence flood hazards. Similarly, for urban flood vulnerability, population density, land use, dwelling quality, household income, distance to cultural heritage, and distance to medical centers and hospitals are the most important factors. The integrated technique for both objective and semi-subjective data as outlined in the present study shows credible results that can be obtained without complicated modeling and costly field surveys. The proposed method is especially helpful in areas with little data to describe and display flood hazards to managers and decision makers.
Effect of Decreasing the Interception of Solar Illuminance by Vegetation on Ground Temperature in Degraded Grasslands
Authors: Zhang Hui , Fan Juan , Gao Di , Liu Yulin , Du Huishi
Published: April 2022

Reduced vegetation cover caused by grassland degradation results in the interception of solar illuminance significantly decreasing, then leading to an increase in ground temperature, which has a significant impact on biological growth and regional climate. Based on the field experiment, we explore the interception of solar illuminance by grasslands with three degrees of degradation and its effect on the soil temperature. Solar illuminance at various heights and times was measured to obtain the interception by vegetation, which included reduction by physical shielding and consumption by the plants’ life activities. Solar illuminance in the subareas sprayed with herbicide was merely reduced by physical shielding, and the difference in solar illuminance interception between normally growing grasslands and fatal grasslands was used for the plants’ life activities. This method described above was almost the first to be used for the exploration of the functional allocation of solar illuminance interception. The percentage of solar illuminance interception was largest in the non-degraded grassland (80–95% at different times), including a 50–60% reduction on account of physical shielding and a 20–45% consumption by the grass’s life activities. Light interception by grassland vegetation directly reduced the grassland temperature. The increment of ground temperature reaches 4–13 °C when a non-degraded grassland turns into a severely degraded grassland.
Public Perceptions of Reuse of Faecal Sludge Co-Compost in Bhubaneswar, India
Authors: Singh Shirish , Ibrahim Mohammed Ali , Pawar Sumeet , Brdjanovic Damir
Published: April 2022

Although faecal sludge (FS) co-compost contains vital nutrients, there are several barriers limiting adoption and reuse of FS co-compost in agriculture. This study in Bhubaneswar found that health risk and bad odour were the two topmost negative perceptions of FS co-compost reuse. The main factors influencing farmers’ negative perceptions of FS co-compost were bad odour and fear of infection, whereas socio-cultural/religious beliefs and bad odour were the key factors influencing the negative perceptions of urban households practising kitchen gardening (UHPKG). Fear of infection and bad odour were the key factors influencing fertiliser retailers’ negative perceptions, while inadequate information, unavailability, and lack of government policy on FS co-compost reuse were the key factors influencing Farmer Producer Organisations’ negative perceptions. The majority of farmers (95%) and UHPKG (72%) were unwilling to consume food crops grown with FS co-compost, mainly because of feelings of disgust, fear of infection, and religious and socio-cultural beliefs.
Heavy Metal Pollution and Its Prior Pollution Source Identification in Agricultural Soil: A Case Study in the Qianguo Irrigation District, Northeast China
Authors: Wang Weiwei , Lu Nan , Pan He , Wang Zirui , Han Xu , Zhu Zhichao , Guan Jiunian
Published: April 2022

Heavy metals are the primary pollutants in agricultural soil and have hindered the sustainable development of agriculture. To control heavy metal pollution, it is essential to identify the pollution sources, particularly the prior source, in agricultural soils. In the current study, Qianguo Irrigation District, a typical agricultural region in Northeast China, was selected to be investigated for the source apportionment of soil heavy metals and identify the prior pollution source. The results showed that the study area was at a moderate pollution level with considerable ecological risk, while Hg and Cd were the main pollutants. Human-health risk assessment indicated that the non-carcinogenic risk for all populations was acceptable (HI < 1), and the carcinogenic risk was not negligible (10−6 < TCR < 10−4). The main pollution sources were concluded to be of lithogenic origin (35.5%), livestock manure (25.4%), coal combustion (21.5%), and chemical fertilizers (17.7%). Coal combustion was identified as the prior pollution source, accounting for 47.69% of the RI contribution. This study can provide scientific support for environmental management and pollution control of soil heavy metals in agricultural regions.
Analysis and Design of Series-LC-Switch Capacitor Multistage High Gain DC-DC Boost Converter for Electric Vehicle Applications
Authors: Khalid Hassan , Mekhilef Saad , Mubin Marizan Binti , Seyedmahmoudian Mehdi , Stojcevski Alex , Rawa Muhyaddin , Horan Ben
Published: April 2022

Research into modern transportation systems is currently in progress in order to fully replace the traditional inter-combustible engine with a noiseless, fast, energy-efficient, and environmentally friendly electric vehicle. Electric vehicles depend on an electric motor and require highly efficient converter drive circuits. Among these converters, DC-DC boost converters play a major role in charging not only the battery banks but also in providing the DC-link excitation voltage in transformerless applications. However, the development of these converters, which have higher voltage and current gain with minimum components, minimum voltage, and current stress, is quite challenging. Therefore, this research work aims to address these issues and also to improve overall system performance. These aims are achieved by developing a series LC-based single-stage boost converter, and extending its gain through a multi-stage boost converter using switch capacitor phenomena. This article also presents a complete operating model in continuous conduction mode. The proposed converter is tested under various testing conditions, such as output loading, input voltage levels, and duty cycle ratio for a 50 W resistive load. The results are compared with existing models. The proposed converter is stated to have achieved the highest efficiency, i.e., 96.5%, along with extendable voltage gain with reduced voltage and current stresses, which is a major contribution to this research field.
Waste to Hydrogen: Elaboration of Hydroreactive Materials from Magnesium-Aluminum Scrap
Authors: Buryakovskaya Olesya A. , Kurbatova Anna I. , Vlaskin Mikhail S. , Valyano George E. , Grigorenko Anatoly V. , Ambaryan Grayr N. , Dudoladov Aleksandr O.
Published: April 2022

Ball-milled hydroreactive powders of Mg-Al scrap with 20 wt.% additive (Wood’s alloy, KCl, and their mixture) and with no additives were manufactured. Their hydrogen yields and reaction rates in a 3.5 wt.% NaCl aqueous solution at 15–35 °C were compared. In the beginning of the reaction, samples with KCl (20 wt.%) and Wood’s alloy (10 wt.%) with KCl (10 wt.%) provided the highest and second-highest reaction rates, respectively. However, their hydrogen yields after 4 h were correspondingly the lowest and second-lowest percentages—(45.6 ± 4.4)% and (56.0 ± 1.2)% at 35 °C. At the same temperature, samples with 20 wt.% Wood’s alloy and with no additives demonstrated the highest hydrogen yields of (73.5 ± 10.0)% and (70.6 ± 2.5)%, correspondingly, while their respective maximum reaction rates were the lowest and second-lowest. The variations in reaction kinetics for the powders can be explained by the difference in their particle sizes (apparently affecting specific surface area), the crystal lattice defects accumulated during ball milling, favoring pitting corrosion, the morphology of the solid reaction product covering the particles, and the contradicting effects from the potential formation of reaction-enhancing microgalvanic cells intended to induce anodic dissolution of Mg in conductive media and reaction-hindering crystal-grain-screening compounds of the alloy and metal scrap components.
Formal Modeling of IoT-Based Distribution Management System for Smart Grids
Authors: Kousar Shaheen , Zafar Nazir Ahmad , Ali Tariq , Alkhammash Eman H. , Hadjouni Myriam
Published: April 2022

The smart grid is characterized as a power system that integrates real-time measurements, bi-directional communication, a two-way flow of electricity, and evolutionary computation. The power distribution system is a fundamental aspect of the electric power system in order to deliver safe, efficient, reliable, and resilient power to consumers. A distribution management system (DMS) begins with the extension of the Supervisory Control and Data Acquisition (SCADA) system through a transmission network beyond the distribution network. These transmission networks oversee the distribution of energy generated at power plants to consumers via a complex system of transformers, substations, transmission lines, and distribution lines. The major challenges that existing distribution management systems are facing, maintaining constant power loads, user profiles, centralized communication, and the malfunctioning of system equipment and monitoring huge amounts of data of millions of micro-transactions, need to be addressed. Substation feeder protection abruptly shuts down power on the whole feeder in the event of a distribution network malfunction, causing service disruption to numerous end-user clients, including industrial, hospital, commercial, and residential users. Although there are already many traditional systems with the integration of smart things at present, there are few studies of those systems reporting runtime errors during their implementation and real-time use. This paper presents the systematic model of a distribution management system comprised of substations, distribution lines, and smart meters with the integration of Internet-of-Things (IoT), Nondeterministic Finite Automata (NFA), Unified Modeling Language (UML), and formal modeling approaches. Non-deterministic finite automata are used for automating the system procedures. UML is used to represent the actors involved in the distribution management system. Formal methods from the perspective of the Vienna Development Method-Specification Language (VDM-SL) are used for modeling the system. The model will be analyzed using the facilities available in the VDM-SL toolbox.
Convergence Analysis on Data-Driven Fortet-Mourier Metrics with Applications in Stochastic Optimization
Authors: Chen Zhiping , Hu He , Jiang Jie
Published: April 2022

Fortet-Mourier (FM) probability metrics are important probability metrics, which have been widely adopted in the quantitative stability analysis of stochastic programming problems. In this study, we contribute to different types of convergence assertions between a probability distribution and its empirical distribution when the deviation is measured by FM metrics and consider their applications in stochastic optimization. We first establish the quantitative relation between FM metrics and Wasserstein metrics. After that, we derive the non-asymptotic moment estimate, asymptotic convergence, and non-asymptotic concentration estimate for FM metrics, which supplement the existing results. Finally, we apply the derived results to four kinds of stochastic optimization problems, which either extend the present results to more general cases or provide alternative avenues. All these discussions demonstrate the motivation as well as the significance of our study.
The Mediating Role of Job Satisfaction in the Relationship between FWAs and Turnover Intentions
Authors: Berber Nemanja , Gašić Dimitrije , Katić Ivana , Borocki Jelena
Published: April 2022

The problem of employee turnover has been investigated in recent years because more and more countries and organizations are faced with the lack of an adequate labor force. The new generation of employees (Y and Z generations), contemporary political, social, and economic challenges, and the COVID-19 pandemic have raised new issues in human resource management (HRM), especially concerning turnover intentions. In such situations, companies need to create working conditions that will attract, motivate, and retain employees. One possible response is the usage of flexible working arrangements (FWAs) as a more flexible way of organizing traditional jobs and working positions; these arrangements allow employees more possibilities to maintain work–life balance. The main aim of this paper is to investigate the relationship between FWAs and turnover intentions of employees, and the mediating effect of job satisfaction. The theoretical research is based on the literature review. The empirical part of the paper is based on the analysis of a sample of 219 employees from organizations in Serbia. The authors used descriptive statistics and the PLS-SEM method to investigate proposed relations. The results pointed to the positive effects of FWAs and job satisfaction on turnover intentions. In addition, there is an indirect effect of FWAs on turnover intentions through job satisfaction. FWAs may contribute to increasing job satisfaction and, in turn, job satisfaction contributes to decreasing turnover intentions. Job satisfaction mediates this relationship, and employees that are offered FWAs may experience a lower level of turnover intentions when they are satisfied on the job.
Resource Recycling with the Aim of Achieving Zero-Waste Manufacturing
Authors: Awogbemi Omojola , Kallon Daramy Vandi Von , Bello Kazeem Aderemi
Published: April 2022

The management of the huge amounts of waste generated from domestic and industrial activities has continued to be a source of concern for humanity globally because of its impact on the ecosystem and human health. Millions of tons of such used materials, substances, and products are therefore discarded, rejected, and abandoned, because they have no further usefulness or application. Additionally, owing to the dearth of affordable materials for various applications, the environmental impact of waste, and the high cost of procuring virgin materials, there have been intensive efforts directed towards achieving the reduction, minimization, and eradication of waste in human activities. The current review investigates zero-waste (ZW) manufacturing and the various techniques for achieving zero waste by means of resource recycling. The benefits and challenges of applying innovative technologies and waste recycling techniques in order to achieve ZW are investigated. Techniques for the conversion of waste glass, paper, metals, textiles, plastic, tire, and wastewater into various products are highlighted, along with their applications. Although waste conversion and recycling have several drawbacks, the benefits of ZW to the economy, community, and environment are numerous and cannot be overlooked. More investigations are desirable in order to unravel more innovative manufacturing techniques and innovative technologies for attaining ZW with the aim of pollution mitigation, waste reduction, cost-effective resource recovery, energy security, and environmental sustainability.
A Comprehensive Post Evaluation of the Implementation of Water-Saving Measures in Xiangtan, Hunan Province, China
Authors: Zhao Jiangtao , Zhang Xiaojin , Qi Lijian , Liu Li , Huo Miao
Published: April 2022

Water resource is an important foundation to support industrial and agricultural production, in the maintenance of national energy security role is irreplaceable. Water conservation and the effective use of water resources are essential for achieving sustainable development in China. The construction of water-saving society is a prerequisite for realizing efficient utilization of water resources and an important strategic development for moving towards environment-friendly society. This study established an index system to evaluate the implementation of water-saving measures in Xiangtan, Hunan province, China. The index system incorporated five aspects: (1) comprehensiveness; (2) agricultural water; (3) industrial water; (4) domestic water, and; (5) aquatic ecology and environmental management. Analytic hierarchy (AH) was used to determine the weights of indices, and AH was integrated with grey relative analysis to establish a comprehensive system for the evaluation of the water-saving measures in Xiangtan. The results showed that the implementation of water-saving measures in Xiangtan is generally progressing well. However, industrial added value water consumption per 10,000-yuan remains at the primary stage and wastewater reuse remains limited. In addition, water use per 10,000-yuan gross domestic product, the coverage of water-saving irrigation projects, industrial wastewater reuse, and the leakage rate of urban water supply network remain at an intermediate stage. The result of this study can scientifically reflect the level of the water-saving measures in place in Xiangtan and could guide future implementation of water saving measures in Xiangtan and in other cities.
Symmetry and Asymmetry in the Fluid Mechanical Sewing Machine
Authors: Ribe Neil M. , Brun Pierre-Thomas , Audoly Basile
Published: April 2022

The ‘fluid mechanical sewing machine’ is a device in which a thin thread of viscous fluid falls onto a horizontal belt moving in its own plane, creating a rich variety of ‘stitch’ patterns depending on the fall height and the belt speed. This review article surveys the complex phenomenology of the patterns, their symmetries, and the mathematical models that have been used to understand them. The various patterns obey different symmetries that include (slightly imperfect) fore–aft symmetry relative to the direction of belt motion and invariance under reflection across a vertical plane containing the velocity vector of the belt, followed by a shift of one-half the wavelength. As the belt speed decreases, the first (Hopf) bifurcation is to a ‘meandering’ state whose frequency is equal to the frequency Ωc of steady coiling on a motionless surface. More complex patterns can be studied using direct numerical simulation via a novel ‘discrete viscous threads’ algorithm that yields the Fourier spectra of the longitudinal and transverse components of the motion of the contact point of the thread with the belt. The most intriguing case is the ‘alternating loops’ pattern, the spectra of which are dominated by the first five multiples of Ωc/3. A reduced (three-degrees-of-freedom) model succeeds in predicting the sequence of patterns observed as the belt speed decreases for relatively low fall heights for which inertia in the thread is negligible. Patterns that appear at greater fall heights seem to owe their existence to weakly nonlinear interaction between different ‘distributed pendulum’ modes of the quasi-vertical ‘tail’ of the thread.
Special Issue Editorial “Symmetry in the Mathematical Inequalities”
Authors: Minculete Nicuşor
Published: April 2022

The theory of inequalities represents a long-standing topic in many mathematical areas and remains an attractive research domain with many applications [...]
Symmetry in Quantum Theory of Gravity
Authors: Fields Chris
Published: April 2022

Nicolas Gisin [...]
An Iterative Algorithm for the Generalized Reflexive Solution Group of a System of Quaternion Matrix Equations
Authors: Jiang Jing , Li Ning
Published: April 2022

In the present paper, an iterative algorithm is proposed for solving the generalized (P,Q)-reflexive solution group of a system of quaternion matrix equations ∑l=1M(AlsXlBls+ClsXl˜Dls)=Fs,s=1,2,…,N. A generalized (P,Q)-reflexive solution group, as well as the least Frobenius norm generalized (P,Q)-reflexive solution group, can be derived by choosing appropriate initial matrices, respectively. Moreover, the optimal approximate generalized (P,Q)-reflexive solution group to a given matrix group can be derived by computing the least Frobenius norm generalized (P,Q)-reflexive solution group of a reestablished system of matrix equations. Finally, some numerical examples are given to illustrate the effectiveness of the algorithm.
Whispered Speech Detection Using Glottal Flow-Based Features
Authors: Phapatanaburi Khomdet , Pathonsuwan Wongsathon , Wang Longbiao , Anchuen Patikorn , Jumphoo Talit , Buayai Prawit , Uthansakul Monthippa , Uthansakul Peerapong
Published: April 2022

Recent studies have reported that the performance of Automatic Speech Recognition (ASR) technologies designed for normal speech notably deteriorates when it is evaluated by whispered speech. Therefore, the detection of whispered speech is useful in order to attenuate the mismatch between training and testing situations. This paper proposes two new Glottal Flow (GF)-based features, namely, GF-based Mel-Frequency Cepstral Coefficient (GF-MFCC) as a magnitude-based feature and GF-based relative phase (GF-RP) as a phase-based feature for whispered speech detection. The main contribution of the proposed features is to extract magnitude and phase information obtained by the GF signal. In the GF-MFCC, Mel-frequency cepstral coefficient (MFCC) feature extraction is modified using the estimated GF signal derived from the iterative adaptive inverse filtering as the input to replace the raw speech signal. In a similar way, the GF-RP feature is the modification of the relative phase (RP) feature extraction by using the GF signal instead of the raw speech signal. The whispered speech production provides lower amplitude from the glottal source than normal speech production, thus, the whispered speech via Discrete Fourier Transformation (DFT) provides the lower magnitude and phase information, which make it different from a normal speech. Therefore, it is hypothesized that two types of our proposed features are useful for whispered speech detection. In addition, using the individual GF-MFCC/GF-RP feature, the feature-level and score-level combination are also proposed to further improve the detection performance. The performance of the proposed features and combinations in this study is investigated using the CHAIN corpus. The proposed GF-MFCC outperforms MFCC, while GF-RP has a higher performance than the RP. Further improved results are obtained via the feature-level combination of MFCC and GF-MFCC (MFCC&GF-MFCC)/RP and GF-RP(RP&GF-RP) compared with using either one alone. In addition, the combined score of MFCC&GF-MFCC and RP&GF-RP gives the best frame-level accuracy of 95.01% and the utterance-level accuracy of 100%.
Lie-Group Shooting/Boundary Shape Function Methods for Solving Nonlinear Boundary Value Problems
Authors: Liu Chein-Shan , Chang Chih-Wen
Published: April 2022

In the numerical integration of the second-order nonlinear boundary value problem (BVP), the right boundary condition plays the role as a target equation, which is solved either by the half-interval method (HIM) or a new derivative-free Newton method (DFNM) to be presented in the paper. With the help of a boundary shape function, we can transform the BVP to an initial value problem (IVP) for a new variable. The terminal value of the new variable is expressed as a function of the missing initial value of the original variable, which is determined through a few integrations of the IVP to match the target equation. In the new boundary shape function method (NBSFM), we solve the target equation to obtain a highly accurate missing initial value, and then compute a precise solution. The DFNM can find more accurate left boundary values, whose performance is superior than HIM. Apparently, DFNM converges faster than HIM. Then, we modify the Lie-group shooting method and combine it to the BSFM for solving the nonlinear BVP with Robin boundary conditions. Numerical examples are examined, which assure that the proposed methods together with DFNM can successfully solve the nonlinear BVPs with high accuracy.
Significance of Chemical Reaction and Lorentz Force on Third-Grade Fluid Flow and Heat Transfer with Darcy–Forchheimer Law over an Inclined Exponentially Stretching Sheet Embedded in a Porous Medium
Authors: Abbas Amir , Shafqat Ramsha , Jeelani Mdi Begum , Alharthi Nadiyah Hussain
Published: April 2022

The combined impact of a linear chemical reaction and Lorentz force on heat and mass transfer in a third-grade fluid with the Darcy–Forchheimer relation over an inclined, exponentially stretching surface embedded in a porous medium is investigated. The proposed process is mathematically expressed in terms of nonlinear and coupled partial differential equations, with the symmetry of the conditions normal to the surface. To solve the mathematical model of the proposed phenomenon, the partial differential equations are first reduced to ordinary differential equations; then, MATLAB built-in Numerical Solver bvp4c is used to obtain the numerical results of these equations. The influence of all the pertinent parameters that appeared in the flow model on the unknown material properties of interest is depicted in the forms of tables and graphs. The physical attitude of the unknown variables is discussed with physical reasoning. From the numerical solutions, it is inferred that, as Lorentz force parameter M is increased, the velocity of the fluid decreases, but fluid temperature and mass concentration increase. This is due to the fact that Lorentz force retards the motion of fluid, and the increasing resistive force causes the rise in the temperature of the fluid. It is also noted that, owing to an increase in the magnitude of chemical reaction parameter R, the velocity profile and the mass concentration decline as well, but the fluid temperature increases in a reasonable manner. It is noted that, by augmenting the values of the local inertial coefficient Fr and the permeability parameter K*, the velocity field decreases, the temperature field increases, and mass concentration also increases with reasonable difference. Increasing values of Prandtl number Pr results in a decrease in the profiles of velocity and temperature. All the numerical results are computed at the angle of inclination α=π/6. The current results are compared with the available results in the existing literature for this special case, and there is good agreement between them that shows the validation of the present study. All the numerical results show asymptotic behavior by satisfying the given boundary conditions.
A Study on the Bertrand Offsets of Timelike Ruled Surfaces in Minkowski 3-Space
Authors: Abdel-Baky Rashad A. , Mofarreh Fatemah
Published: April 2022

This work extends some classical results of Bertrand curves to timelike ruled and developable surfaces using the E. Study map. This provides support to define two timelike ruled surfaces which are offset in the sense of Bertrand. It is proved that every timelike ruled surface has a Bertrand offset if and only if an equation should be satisfied among their dual invariants. In addition, some new results and theorems concerning the developability of the Bertrand offsets of timelike ruled surfaces are gained.