bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigating Customer Behavior of Using Contactless Payment in China: A Comparative Study of Facial Recognition Payment and Mobile QR-Code Payment
Authors: Zhong Yongping , Moon Hee-Cheol
Published: June 2022

Emerging technologies have made tremendous changes in people’s daily lives, and they have profoundly influenced their economic and consumption activities. Recently, the COVID-19 pandemic has also drastically increased individuals’ usage of contactless payment technologies, such as mobile and facial recognition payments, which has accelerated the transformation of digital transaction services in China. In this study, the findings show that perceived usefulness, perceived ease of use, and service security can affect the perceived value and user satisfaction of using contactless payment. Moreover, a higher perceived value and satisfaction level may encourage more post-adoption behaviors, such as continuous and habitual usage of contactless payment methods or encouraging others to use contactless payment methods via word-of-mouth; however, perceived value did not have a direct effect on continuous usage. In addition, there are certain differences in user behavior depending on whether facial recognition payment or mobile QR-code payment is used. For QR-code payment users, overall, their satisfaction and post-adoption behaviors are more strongly bonded with each other compared with the behaviors of facial recognition payment users. This study has generated more information and insight into the transformation of digital payment and can help managers align their strategies more efficiently in the post-pandemic era.
Green Entrepreneurship: Should Legislators Invest in the Formation of Sustainable Hubs?
Authors: Speckemeier Lars , Tsivrikos Dimitrios
Published: June 2022

This study explores which local factors affect the creation of sustainable or green startups in a geographical area. The analysis aims to help regional legislators get a more nuanced view of regional economic and sustainable policymaking and to promote a transition toward a greener economy. Building on knowledge spillover theory, results from 4301 companies across Europe show that the driving factors for the emergence of green startups go beyond funding opportunities. Knowledge exchange and industry networks are equally if not more important in attracting green entrepreneurs. Results also reveal that green startups are more likely than non-green startups to change their location. Of those who change their location, green founders prefer large cities and have a negative inclination to establish their companies in small cities. Companies in the sustainable information technology (IT) industry are less likely to change their location, whereas green manufacturing companies are more likely to change. In summation, results indicate that the location choices and resulting evolution of clusters for green startups are based on a number of variables, including local knowledge stock and spillovers, company density, availability of educated talent, and industry affiliations.
Potential for Artificial Intelligence (AI) and Machine Learning (ML) Applications in Biodiversity Conservation, Managing Forests, and Related Services in India
Authors: Shivaprakash Kadukothanahally Nagaraju , Swami Niraj , Mysorekar Sagar , Arora Roshni , Gangadharan Aditya , Vohra Karishma , Jadeyegowda Madegowda , Kiesecker Joseph M.
Published: June 2022

The recent advancement in data science coupled with the revolution in digital and satellite technology has improved the potential for artificial intelligence (AI) applications in the forestry and wildlife sectors. India shares 7% of global forest cover and is the 8th most biodiverse region in the world. However, rapid expansion of developmental projects, agriculture, and urban areas threaten the country’s rich biodiversity. Therefore, the adoption of new technologies like AI in Indian forests and biodiversity sectors can help in effective monitoring, management, and conservation of biodiversity and forest resources. We conducted a systematic search of literature related to the application of artificial intelligence (AI) and machine learning algorithms (ML) in the forestry sector and biodiversity conservation across globe and in India (using ISI Web of Science and Google Scholar). Additionally, we also collected data on AI-based startups and non-profits in forest and wildlife sectors to understand the growth and adoption of AI technology in biodiversity conservation, forest management, and related services. Here, we first provide a global overview of AI research and application in forestry and biodiversity conservation. Next, we discuss adoption challenges of AI technologies in the Indian forestry and biodiversity sectors. Overall, we find that adoption of AI technology in Indian forestry and biodiversity sectors has been slow compared to developed, and to other developing countries. However, improving access to big data related to forest and biodiversity, cloud computing, and digital and satellite technology can help improve adoption of AI technology in India. We hope that this synthesis will motivate forest officials, scientists, and conservationists in India to explore AI technology for biodiversity conservation and forest management.
Spatial–Temporal Variations of Water Ecosystem Services Value and Its Influencing Factors: A Case in Typical Regions of the Central Loess Plateau
Authors: Xiu Yuan , Wang Ni , Peng Fangxu , Wang Quanxi
Published: June 2022

Water resources provide indispensable ecosystem services, which are related to human well-being and sustainable social development. Accurately measuring the water ecosystem services value (WESV), and then grasping its changing characteristics, is particularly important for solving water problems. In this study, the typical area of the central Loess Plateau location is taken as the research area. Based on remote sensing images and statistical data, the direct market method combined with the equivalent factor method was used to calculate the WESV including groundwater and surface water, which is of greatest originality. The temporal and spatial variation characteristics in 2010, 2015 and 2020 were analyzed. Then, four WESV driving factors including per capita GDP, population density, proportion of water areas, and water consumption were selected, and the geographically weighted regression (GWR) model was used to analyze the spatial distribution pattern and temporal variation of WESV’s response to the influencing factors. The results showed that WESV experienced a process of first decreasing and then increasing, which was mainly caused by Yulin. For the composition of WESV, the proportion of provisioning services value has increased, which caused the proportion of regulating services value to decrease. The correlations between four factors and WESV were different. The distribution pattern of the influences was spatially heterogeneous, which showed regular variations over time. These results indicate the necessity of WESV’s independent research and provide a realistic basis for ecological compensation in the Yellow River Basin.
Mapping Studies on Sustainability in the Performance Measurement of Public-Private Partnership Projects: A Systematic Review
Authors: Akomea-Frimpong Isaac , Jin Xiaohua , Osei-Kyei Robert
Published: June 2022

The integration of sustainable practices into infrastructure projects under the auspices of public-private partnerships (PPPs) is vital in the attainment of United Nation’s Sustainable Development Goals (SDGs). Since the inception of the SDGs in 2015, the attention of world has been shifting towards more sustainable practices and it is essential that the conventional performance measurement models on PPP projects also adapt to the trend of sustainable practices. Therefore, This study aims at reviewing and operationalising sustainable performance measures for the PPP infrastructure projects. A systematic literature review (SLR) methodology was utilised in this study. The research process began with the search, retrieval and selection of thirty-three (33) journal articles. Thoroughly, the selected articles were contently analysed to form key themes that form the basis of this research’s findings. The outcomes of this review demonstrate twenty-seven (27) most critical sustainable performance criteria of PPP projects such as the lowest project costs, green index, disability-friendly inclusion rate and carbon emission per project among others. Although, the study is limited to few journal articles, it provides theoretical and practical understanding of integration of sustainability in PPPs. Further, it gives a list of relevant research gaps for further studies. This study contributes to the benchmarking and management of sustainable performance assessment of PPP projects.
A Systematic Study on a Customer’s Next-Items Recommendation Techniques
Authors: Ilyas Qazi Mudassar , Mehmood Abid , Ahmad Ashfaq , Ahmad Muneer
Published: June 2022

A customer’s next-items recommender system (NIRS) can be used to predict the purchase list of a customer in the next visit. The recommendations made by these systems support businesses by increasing their revenue and providing a more personalized shopping experience to customers. The main objective of this paper is to provide a systematic literature review of the domain to analyze the recent techniques and assist future research. The paper examined 90 selected studies to answer the research questions concerning the key aspects of NIRSs. To this end, the main contribution of the paper is that it provides detailed insight into the use of conventional and deep learning techniques, the popular datasets, and specialized metrics for developing and evaluating these systems. The study reveals that conventional machine learning techniques have been quite popular for developing NIRSs in the past. However, more recent works have mainly focused on deep learning techniques due to their enhanced ability to learn sequential and temporal information. Some of the challenges in developing NIRSs that need further investigation are related to cold start, data sparsity, and cross-domain recommendations.
Developing an Objective Framework to Evaluate Street Functions
Authors: Sheikh-Mohammad-Zadeh Abbas , Saunier Nicolas , Waygood E. O. D.
Published: June 2022

Urban street networks are a vital part of urban areas and have a remarkable influence over quality of life and the use of sustainable modes. They make up about 80% of public space and shape urban activities and identity. Therefore, it is crucial to design, develop, and maintain streets in such a way as to make the most of this large and important space in a sustainable manner. Streets have three main functions: to provide access to adjoining properties, to allow transit of users on their way from their origin to their destination, and to provide space for social activities. As such, there is a need to develop indicators, methods, and tools to evaluate how streets fulfill their functions. However, most of the previously developed frameworks rely on measuring the physical environment and transportation facilities, which reflect the potential use of streets, as opposed to their actual use. To address this gap, the main objective of this paper is to propose a holistic and objective framework to evaluate streets based on their actual use by all users. The proposed framework is developed based on direct user observation to assess the various street functions (i.e., transit, access, and place) using objective indicators at a microscopic (individual) level. The developed framework and tools build on street use evaluation by diverse disciplines such as transportation engineering, urban planning, and public health. It will help transportation agencies and urban planners to manage streets and public spaces so that they fulfill their expected functions while minimizing the negative impacts.
Inheritance of Traditional Family Values: A Comparative Study of Family Ancestral Shrines and Related Paintings of Lee Family
Authors: Sun Yikang , Lo Hsienfu , Cao Jing , Lin Rungtai
Published: June 2022

Apart from providing a haven, a home serves also as a place where people can develop their personalities and temperaments. Traditions within families are an often-unseen force that has a profound effect on people. In this article, the authors explore the meaning and value of family traditional inheritance in the current context and what manifestations may occur. After reviewing the history and characteristics of ancestral shrines, this study further examined the forms of expression used to express “home” and “family traditions” from the creator’s perspective. A conceptual framework is provided for subsequent case studies. Considering the role and importance of different creations in the transmitting of family traditions, a family memorial hall named “Qiyun Residence” and a series of paintings called “Home: Sweet Home” were created by members of this family to analyze and interpret family traditions. The importance of family traditions cannot be overstated, but they must be appropriately expressed. It is our aim that the examples presented in this article show how “Traditional” can be transferred to “Modernity” for the sustainability of culture.
Geoheritage in a Forest: Traces of Ice Sheets in Pałuki, Western Poland
Authors: Górska-Zabielska Maria
Published: June 2022

In this paper, we present nine large glacial erratic boulders laying in situ in the forested areas of Pałuki in the north-eastern Wielkopolska (Western Poland). They are discussed against the background of the rich geodiversity of the area, which owes its main features to the last ice sheet (Weichselian, MIS2), the front of which, after a momentary oscillation on the line of the Ryszewo moraines, began to recede and retreated northwards. Our field work consisted of collecting information on the dimensions, petrographic type, and type of eratics as well as specific features of the rock morphology. Attention was paid to the records of sub/inglacial processes, as well as periglacial processes affecting the foreland of the melting ice sheet and contemporary morphogenetic processes. In the detailed description of the boulders, attention is drawn to their scientific, cognitive, educational, cultural, conservational, pro-environmental and recreational importance. The recipient/beneficiary of such information can be anyone who is sensitive to the beauty of inanimate nature, who feels like an inheritance of the geological past of their region, or who wants to broaden their horizons with knowledge from the glacial era. Recognized and disseminated heritage of inanimate objects in nature through the transfer of expert knowledge has a great potential to become an effective generator of sustainable development of peripheral tourist areas such as Pałuki. Geotourism, which can be successfully developed in forests, is a tool for increasing the quality of life of inhabitants. Nowadays, social expectations regarding the functions of a forest are evolving in favour of social, educational (ecological education), tourist, and recreational functions.
Spatially Heterogeneity Response of Critical Ecosystem Service Capacity to Address Regional Development Risks to Rapid Urbanization: The Case of Beijing-Tianjin-Hebei Urban Agglomeration in China
Authors: Wang Kaiping , Wang Weiqi , Zha Niyi , Feng Yue , Qiu Chenlan , Zhang Yunlu , Ma Jia , Zhang Rui
Published: June 2022

Urban agglomerations have become the new spatial unit of global economic competition. The intense socioeconomic activities attributed to the development of urban agglomerations are bound to cause damage to the ecosystem services of these urban agglomerations. This study adopts the Beijing-Tianjin-Hebei urban agglomeration in China as the research object, analyzes the spatiotemporal evolution of its critical ecosystem service capacity to address regional ++-development risks from 2000–2018, and employs the Moran’s I and geographically weighted regression model to explore the spatial correlation and spatial heterogeneity in the responses of urbanization and ecosystem services. The study indicates that (1) from 2000–2018, the ecosystem services of the Beijing-Tianjin-Hebei urban agglomeration exhibit an increase and then a decline, reaching the highest index in 2015; (2) the ecosystem services reveal obvious spatial heterogeneity with the Yan and Taihang Mountains region as the boundary; (3) built-up area ratio, GDP density, and population density exhibit highly obvious negative correlation driving characteristics on ecosystem services; and (4) the construction land ratio exerts a notable impact on areas with a high ecosystem services, while the spatial response of the effect magnitude of the population and GDP densities is largely influenced by intensive, high-pollution and energy-consuming industries. This article also proposes strategies for the optimization of ecological resources and spatial control, which are dedicated to mitigating the negative impacts of rapid urbanization processes on ecosystem services.
Will Greenwashing Result in Brand Avoidance? A Moderated Mediation Model
Authors: Xiao Zengrui , Wang Ying , Guo Dongjie
Published: June 2022

Greenwashing has become a widespread phenomenon and obstructs green products, but literature on how consumers react to misbehaving brands is still scarce. This study aims to investigate the effect of greenwashing on consumers’ brand avoidance, integrating the mediating effect of brand hypocrisy and the moderating effect of CSR–CA belief. Data were acquired from a questionnaire survey of 317 consumers. Hypotheses were tested in a first-stage moderated mediation model with a bootstrapping method using the PROCESS program in SPSS. The empirical results demonstrated that greenwashing has a positive effect on brand avoidance, which is partially mediated by brand hypocrisy. Meanwhile, the positive effects of greenwashing on brand hypocrisy and brand avoidance are both weaker at higher levels of CSR–CA belief. Furthermore, the mediating effect of brand hypocrisy is also weaker at higher levels of CSR–CA belief. Based on these findings, we recommend that brands fulfill their environmental claims and balance their quality control, manufacturing costs and environment protection. Moreover, the government and environmental protection organizations should educate the public that there is not necessarily a tradeoff between corporate social responsibility (CSR) and corporate capability (CA).
Analysis of Grid-Interactive PV-Fed BLDC Pump Using Optimized MPPT in DC–DC Converters
Authors: Oliver Jeba Singh , David Prince Winston , Balachandran Praveen Kumar , Mihet-Popa Lucian
Published: June 2022

In solar photovoltaic (PV) system-based Brushless DC (BLDC) motors for water pumping application, the role of DC/DC converters is very important. In order to extract the maximum power from the PV array, an efficient DC/DC converter is essential at the intermediate stage. In this work, different DC/DC converter topologies suitable for BLDC motors are proposed. The converters are supported by an optimized maximum power point tracking system to provide a reliable operation. Recent optimization algorithms such as fuzzy logic, perturb and observe, grey wolf, and whale optimization are implemented with the PI controller in maximum power point tracking to maximize the conversion efficiency. The obtained results using SEPIC, LUO, and interleaved LUO converters provide a comparative study in the case of converter output, motor parameters, and grid output. The performance analysis on three different converters and multiple optimization methods are carried out. By analyzing the performance of different converter topologies, the interleaved LUO converter outperforms the other two converters with the results of a voltage gain ratio of 1:22, conversion efficiency of 98.3%, and grid current THD of 2.9%. Moreover, regarding the power quality aspect, the total harmonic distortion of the grid current is maintained below the IEEE-519 standard. In addition, the developed system has an advantage of operating both in stand-alone and grid-connected operation modes.
Constructs for Assessing Integrated Reports—Testing the Predictive Validity of a Taxonomy for Organization Size, Industry, and Performance
Authors: Lueg Rainer
Published: June 2022

The lack of an agreed valid measurement of integrated reporting () among organizations poses a constant problem to empirical researchers. Lueg and Lueg proposed an  score that rates and categorizes reports according to their compliance with the principles of . This study tested and validated their proposed coding catalogue, constructs, and taxonomy using capital market data and multivariate statistics. These findings suggested that this  score and the corresponding taxonomy for classifying reports has a high predictive validity and can be used by future researchers to measure . In particular, this  score confirmed that integrated thinking reports tend to be published by large organizations in controversial industries with an above-average performance (Adj. R2 = 42.2%). The findings also suggested that the construct form of the integrated report contributes more explanatory power than the construct content. In this regard, the results indicated that only full implementers of  show associations with performance, unlike organizations that partially comply with the  principles.
Research on the Destruction Resistance of Giant Urban Rail Transit Network from the Perspective of Vulnerability
Authors: Xu Xueguo , Xu Chen , Zhang Wenxin
Published: June 2022

Giant urban rail transit (GURT) systems have been formed in many metropolises and play a critical role in addressing serious traffic congestion. Unfortunately, as a dynamic and complex system, the vulnerability of GURT networks under various failure scenarios will be more prominent as the network expansion continues. Thus, it is imperative to explore the complex structural characteristics of the network and improve the ability to deal with the disturbance of emergencies. In this study, the destruction resistance of GURT networks with scale growth is illustrated from a vulnerability perspective. Specifically, taking Shanghai rail transit (SHRT) system as an example, the network topology model is constructed using the Space L method, and the network structure characteristics are analyzed based on the complex network theory. In addition, five attack strategies are developed to represent random and targeted attacks during the simulation of network failure, and two metrics are determined to evaluate the network vulnerability. Some meaningful results have been obtained: (i) The Shanghai rail transit planning network (SHRTPN) has increased the network efficiency by more than 10% over the Shanghai rail transit operating network (SHRTON) and has effectively enhanced the network destruction resistance. (ii) The SHRT network is a small-world network and shows significant vulnerability under the targeted attacks. The failure of only 3% high betweenness stations in SHRTON can lead to a 66.2% decrease in the network efficiency and a 75.8% decrease in the largest connected component (LCC) ratio. (iii) Attacking stations will cause more severe network failures than attacking edges, and it is necessary to focus on preventing catastrophic network failure caused by the critical station’s failure breaking the threshold. Finally, the strategies for improving the destruction resistance of GURT networks are proposed. The findings of this research can provide an essential reference for the rational planning, safety protection, and sustainable construction of GURT systems.
The Informal City: Exploring the Variety of the Street Vending Economy
Authors: Martínez Lina , Short John Rennie
Published: June 2022

Street vending is one of the most important economic activities of the informal sector. This paper highlights the diversity of street vending. We extend the previous analysis of the informal economy in one city, Cali, Colombia, with data on informal workers in two public spaces: Downtown and Santa Helena, and workers in the mass transit bus system. We show how the informal economy varies greatly within one city. Provided the lack of data in the study of the informal economy, most studies describe the dynamics of the informal sector as uniform across the urban space. In this analysis, we present evidence about the spatial segmentation and diversity of street vendors by their socioeconomic conditions, profits, and earnings. We further explore the spatial segmentation by analyzing the large indebtedness and financial exclusion of street vendors. We report that workers in the mass transit system are the most vulnerable and indebted and how the large indebtedness to illegal payday lenders is a major barrier for street vendors to move out of poverty. We conclude that it is important to understand the granularity of the urban informal economy in order to craft suitable public policies.
The Effects of Substrate Temperature on the Growth, Microstructural and Magnetic Properties of Gadolinium-Containing Films on Aluminum Nitride
Authors: Ekstrum Craig A. , Venkatesan Ragavendran , Kendrick Chito , Einav Moshe , Sivaprakash Paramasivam , Mayandi Jeyanthinath , Arumugam Sonachalam , Pearce Joshua M.
Published: June 2022

To facilitate future novel devices incorporating rare earth metal films and III-V semiconductors on Si substrates, this study investigates the mechanisms of growth via molecular beam epitaxy of gadolinium (Gd) on aluminum nitride (AlN) by determining the impact of substrate temperature on microstructure. The Gd films underwent extensive surface analysis via in situ reflective high energy electron diffraction (RHEED) and ex-situ SEM and AFM. Characterization of the surface features of rare earth metal films is important, as surface geometry has been shown to strongly impact magnetic properties. SEM and AFM imaging determined that Gd films grown on AlN (0001) from 80 °C to 400 °C transition from wetting, nodular films to island–trench growth mode to reduce in-plane lattice strain. XRD and Raman spectroscopy of the films revealed that they were primarily comprised of GdN, Gd and Gd2O3. The samples were also analyzed by a vibrating sample magnetometer (VSM) at room temperature. From the room temperature magnetic studies, the thick films showed superparamagnetic behavior, with samples grown between 240 °C and 270 °C showing high magnetic susceptibility. Increasing GdN (111) 2θ peak position and single-crystal growth modes correlated with increasing peak magnetization of the thin films, suggesting that lattice strain in single-crystal films was the primary driver of enhanced magnetic susceptibility.
Inductance Analysis of Two-Phase Winding Segmented Permanent Magnet Linear Synchronous Motor
Authors: Zhang Tuanshan , Mei Xuesong
Published: June 2022

The inductance of a winding segmented permanent magnet linear synchronous motor (WS-PMLSM) is affected by winding disconnection and coupling length variation, which makes the variation of inductance more complicated, and this paper proposes incremental inductance, apparent inductance, and positional inductance to reveal this phenomenon, which gives a theoretical basis for mathematical modeling and thrust fluctuation suppression. First, an analytical approach is used to derive a fully coupled state model using the magnetomotive force and specific permeability function. Second, the domain of the specific permeability function is extended and the inductance expressions are calculated for the whole moving range. Finally, the inductance of the prototype WS-PMLSM with a two-phase winding is experimentally verified, and it is proposed that the effects of the three inductive components on the system should be considered comprehensively when implementing control of the WS-PMLSM.
On Fractional Hybrid Non-Linear Differential Equations Involving Three Mixed Fractional Orders with Boundary Conditions
Authors: Li Fang , Zhang Liping , Wang Huiwen
Published: June 2022

In this paper, we study a class of non-linear fractional hybrid differential equations involving three mixed fractional orders with boundary conditions. Under weak assumptions, a formula of solutions is constructed and the existence results of the solutions for the problem are established. The results can be used to solve more general fractional hybrid equations, such as the general variable coefficient fractional hybrid Langevin equations. Moreover, the form of the solution for this kind of equation can provide a theoretical basis for the further study of the positive solution and its symmetry. We provide an example to support our main result.
Asymmetric Motion of Magnetic Skyrmions in Ferromagnetic Nanotubes Induced by a Magnetic Field
Authors: Bao Bei , Yang Mingming , Yan Ming
Published: June 2022

Magnetic skyrmions, featuring topological stability and low driving current density, are believed to be a promising candidate of information carriers. One of the obstacles to application is the skyrmion Hall effect, which can lead to the annihilation of moving skyrmions at the lateral boundary of thin-film tracks. In order to resolve this issue, it was recently proposed to exploit ferromagnetic nanotubes as alternative skyrmion guides. In this work, we investigate the field-effect of current-driven skyrmion motion in nanotubes using micromagnetic simulations. It is found that, in the presence of an axial field, the skyrmion motion becomes asymmetric in tubes. This is fundamentally different from the flat strip, in which a field has little influence on the skyrmion dynamics. Based on the dissipation tensor determined by the spin texture of the skyrmions, the solution of the Thiele equation is obtained, yielding a perfect match with simulations. We argue that the asymmetry of the skyrmion dynamics originates from the curvature of the nanotube.
A Review of Searches for Evidence of Tachyons
Authors: Ehrlich Robert
Published: June 2022

Here, we review searches for empirical evidence for the existence of tachyons, superluminal particles having m2<0. The review considers searches for new particles that might be tachyons, as well as evidence that neutrinos are tachyons from data that may have been gathered for other purposes. Much of the second half of the paper is devoted to the 3+3 neutrino model including a tachyonic mass state, which has empirical support from a variety of areas. Although this is primarily a review article, it contains several newly identified results.
Inversed Model-Based Disturbance Observer Base on Adaptive Fast Convergent Sliding Mode Control and Fixed-Time State Observer for Slotless Self-Bearing Motor
Authors: Nguyen Quang Dich , Giap Van Nam , Huang Shyh-Chour
Published: June 2022

The slotless self-bearing motor (SSBM) is a motor with its self-bearing function. The mechanical structure of the motor is six symmetrical hexagonal shapes. The main control problem for this motor is disturbance and uncertainty rejection. Therefore, this paper proposes a new disturbance observer (DOB) based on an optimal fixed-time state observer (OFTSOB) and adaptive sliding mode control (SMC) for the motor. Firstly, the optimal state observer was used to construct to obtain the information of the states of the bearing-less motor system. Second, a new disturbance observer base on the fast speed reaching law is proposed for estimating the unknown dynamics and unpredicted uncertainty of the motor system. Third, the adaptive fast-reaching law-sliding mode control is designed to control the positions and rotational speed. Fourth, the proposed control system is proved via the Lyapunov theorem. Finally, the corrections of proposed method once again tested by using MATLAB simulation. The obtained results figured out that the proposed method is good at rejection disturbance and uncertainty and precision in control the movement and rotation. The novelties of the proposed method are that the gains of fixed-time observer were met by the support of optimal pole placement method, the disturbances were mostly rejected by a new reaching law of unknown input observer.
A More Flexible Reliability Model Based on the Gompertz Function and the Generalized Integro-Exponential Function
Authors: Reyes Jimmy , Cortés Pedro L. , Rojas Mario A. , Arrué Jaime
Published: June 2022

This work presents a new distribution that allows modeling data from a random variable with non-negative values. The new family is defined by a stochastic representation of a scaled mixture of a random variable with a Gompertz distribution (G) and a random variable with a uniform distribution on the interval (0,1). The result of this gives rise to a new random variable with a Slash Gompertz (SG) distribution that is more flexible than the Gompertz distribution, that is, it better models atypical data, presenting tails heavier than the Gompertz distribution. The density and some general properties of the resulting family are studied, including its moments and kurtosis coefficient. The inference of the parameters is carried out using the method of moments and maximum likelihood. Finally, illustrations of particular cases of this family are shown, adjusting in this case two sets of real data and estimating the parameters by maximum likelihood, where it is verified that this new family of distributions fits the reliability function better than the distributions of Gompertz (G), Slash Birnbaum Saunders (SBS), Slash Weibull (SW), and Gompertz-Verhults (GV).
Recent Advances in Surrogate Modeling Methods for Uncertainty Quantification and Propagation
Authors: Wang Chong , Qiang Xin , Xu Menghui , Wu Tao
Published: June 2022

Surrogate-model-assisted uncertainty treatment practices have been the subject of increasing attention and investigations in recent decades for many symmetrical engineering systems. This paper delivers a review of surrogate modeling methods in both uncertainty quantification and propagation scenarios. To this end, the mathematical models for uncertainty quantification are firstly reviewed, and theories and advances on probabilistic, non-probabilistic and hybrid ones are discussed. Subsequently, numerical methods for uncertainty propagation are broadly reviewed under different computational strategies. Thirdly, several popular single surrogate models and novel hybrid techniques are reviewed, together with some general criteria for accuracy evaluation. In addition, sample generation techniques to improve the accuracy of surrogate models are discussed for both static sampling and its adaptive version. Finally, closing remarks are provided and future prospects are suggested.
Dual-Channel Supply Chain Pricing Decisions under Discounted Advertising Value
Authors: Yan Ke , Liu Shuai , Zuo Min , Zheng Jiamin , Xu Yadong
Published: June 2022

Retailers advertise on different sales channels. When consumers buy online, the effectiveness of advertising is discounted because they cannot feel the product. Observing this phenomenon, this paper studies the advertising strategy of a dual-channel retailer. In this paper, we build stylized game models for the retailer’s price and advertising levels on online and offline channels, respectively. Our contribution is to provide prescriptions for how dual-channel retailers make price and advertise decisions and determine which channel is more profitable for retailers. We find that advertising discounts are not always harming the retailer’s profits. The level of advertising discounts causes retailers to increase the selling price when consumers engage in online shopping. Also, we derive that retailers can choose the sales channels based on the level of consumers’ channel preference of consumers. Interestingly, an increase in the level of advertising discounts will contribute to the growth of the retailer’s profit. Finally, by numerical analysis, we demonstrate the robustness of the results.
Smart Cities from the Perspective of Systems
Authors: Ammara Umme , Rasheed Khansa , Mansoor Athar , Al-Fuqaha Ala , Qadir Junaid
Published: June 2022

Modern cities are complex adaptive systems in which there is a lot of dependency and interaction between the various stakeholders, components, and subsystems. The use of digital Information and Communications Technology (ICT) has opened up the vision of smart cities in which the city dwellers can have a better quality of life and the city can be better organized and managed. The deployment of ICT solutions, however, does not automatically or invariably improve the quality of living of the citizens. Analyzing cities as complex systems with various interacting sub-systems can help us understand urban dynamics and the fate of smart cities. We will be able to analyze various policy interventions and ascertain their effectiveness and anticipate potential unintended consequences. In this paper, we discuss how smart cities can be viewed through the lens of systems thinking and complex systems and provide a comprehensive review of related techniques and methods. Along with highlighting the science of cities in light of historic urban modeling and urban dynamics, we focus on shedding light on the smart city complex systems. Finally, we will describe the various challenges of smart cities, discuss the limitations of existing models, and identify promising future directions of work.
Blockchain Traceability System in Complex Application Scenarios: Image-Based Interactive Traceability Structure
Authors: Ju Chunhua , Shen Zhonghua , Bao Fuguang , Wen Zhikai , Ran Xi , Yu Chaoyang , Xu Chonghuan
Published: June 2022

To solve the problems exposed by the application of blockchain technology under complex scenarios, such as fraudulent use of data, hard to store huge amounts of data, and low traceability efficiency under an ultra-huge number of traceability requests, this paper constructs an image-based interactive traceability structure by using images as an enhancement. By adding pointers to raw image files, a specific file structure is formed for traceability, and the traceability process is separated from the verification process, therefore realizing the distributed traceability of “traceability off the chain and verification on the chain”. The experimental results show that, compared with the traditional blockchain traceability mode, the interactive traceability structure can reduce the data retrieval pressure and greatly improve the traceability efficiency of a specific transaction chain. With the growth of the span of the transaction chain, the traceability efficiency advantage of the interactive traceability structure becomes more obvious.
A Model for Knowledge Management Systems in the UbuntuNet Alliance Member Institutions
Authors: Yigzaw Samuel T. , Jormanainen Ilkka , Tukiainen Markku
Published: June 2022

In the current knowledge-driven global economy, higher education and research institutions are taking a leading role as the hubs for knowledge creation and sharing. In contribution to the needed coordination of the efforts, this paper presents a guiding model thorough assessment of the prevailing status of knowledge resources sharing and collaboration in the regional alliance for education and research networks in the eastern and southern African countries—UbuntuNet Alliance. This research carried out a qualitative study with semi-structured interviews with CEOs of three active national research and education networks (NRENs), representing both the government-run and private consortium-based settings. The study adopted a socio-technical perspective in assessing the technological engagements and the knowledge resources utilization within and among the NRENs in the region. The findings show that the NRENs share a similar set of challenges as well as missions and objectives; they aspire to provide technology-enhanced knowledge-sharing platforms within and across their domains. Finally, it presents UbuntuKMS Model—a comprehensive technology-enhanced knowledge management systems model that intends to provide guidance for the NRENs to orient their efforts accordingly. The research revealed that contextual considerations in developing system solutions are vital as the developing economies experience unique realities on the ground.
Start-Ups as Adaptable Stable Systems Based on Synchronous Business Models
Authors: Fox Stephen , Vahala Päivi
Published: June 2022

Business models have been a popular topic in research and practice for more than twenty years. During this time, frameworks for formulating business models have been developed, such as the business model canvas. Moreover, different business model frameworks have been proposed for different sectors. Yet, these frameworks have the fundamental shortcoming of not addressing directly and persistently the primary objective of start-ups: to survive in changing environments. The aim of the action research reported in this paper is to overcome that fundamental shortcoming. This is an important topic because the majority of start-ups do not survive. In this paper, first principles for survival in changing environments are related to business models. In particular, action research to reframe start-ups as adaptable stable systems based on synchronous business models is reported. The paper provides three principal contributions. The contribution to business model theory building is to relate survival first principles revealed through natural science research to business models. Reference to first principles highlight that survival depends on maintaining both external adaptability and internal stability through synchronization with changing environments. The second contribution is to business model practice through describing a simple business modeling method that is based on the scientific first principles. The third contribution is to provide an example that bridges the rigor–relevance gap between scientific research and business practice.
Histopathological Alterations in the Livers of Chronic Hepatitis Patients Exposed to Agent Orange/Dioxin in Vietnam
Authors: Pham Phu Quang , Nguyen Vuong Ba , Pham Tai The , Duong Nhuong Xuan , Nguyen Ha Trong , Ha Quang Van , Nguyen Thuan Duc , Hoang Tuan Minh , Dinh Dong Tien , Tran Quynh Thi Nhu , Bui Linh Kim , Vu Thuy Thi , Phan Manh Van , Luong Tuan Minh , Nguyen Khanh , Vu Dung Anh , Pham Thao Ngoc
Published: June 2022

We investigated changes in some laboratory indices and the liver histology of chronic hepatitis patients who were exposed to dioxin. In 2014, we collected liver biopsy samples for histopathological examination from 33 chronic hepatitis patients living around the Da Nang Airbase, which is a dioxin-contaminated area due to the herbicide spraying in Vietnam. Dioxin exposure was measured by its levels in the blood. METAVIR classification was used to clarify the liver fibrosis stage. Laboratory tests included ten biochemical and six hematological indices that were measured in the blood. A regression linear model and binary logistic regression were used for data analysis. The observed alterations in the liver at the histological level mainly comprised hydropic degenerative hepatocytes, lymphocytes and polynuclear leukocytes surrounding the liver cells and granular and lipoic degeneration. In addition, increased TCDD levels were associated with increasing aminotransferase (AST), alanine aminotransferase, protein and total bilirubin levels and liver fibrosis stage. Similarly, increased TEQ-PCDD/Fs levels were associated with higher levels of AST and protein and liver fibrosis stage. In conclusion, dioxin exposure altered the liver histology and increased some biochemical marker indices and the liver fibrosis stage of chronic hepatitis patients living in dioxin-contaminated areas in Da Nang, Vietnam.
Lead and Cadmium Bioaccumulation in Fresh Cow’s Milk in an Intermediate Area of the Central Andes of Peru and Risk to Human Health
Authors: Chirinos-Peinado Doris , Castro-Bedriñana Jorge , Ríos-Ríos Elva , Mamani-Gamarra Gloria , Quijada-Caro Elías , Huacho-Jurado Analí , Nuñez-Rojas Wilfredo
Published: June 2022

The dairy basin of the Mantaro River located in the centre of Peru faces serious anthropogenic disturbances as it receives emissions and discharges from the metallurgical mining activity located in the headwaters of the basin and milk contaminated with lead (Pb) and cadmium (Cd) endangers the environmental and human health, especially children. To measure the concentrations of Pb and Cd in milk and the dangers of their consumption in the Peruvian population, 40 milk samples were collected and quantified by atomic absorption spectrometry. The mean concentration of Pb in milk was 15 ± 2.6 µg/kg, which represented 75% of the Maximum Limit (ML), and that of Cd was 505 ± 123 µg/kg, which exceeded the ML by more than 194 times. The estimated weekly intake of Pb for people aged 2–85 years was below the Provisional Tolerable Weekly Intake (PTWI) references, determining risk coefficients (CRD) < 1. Weekly Cd intake was much higher than the PTWIs and CRDs were between 14 and 34, indicating that consumers would experience carcinogenic health effects, with children being at higher risk than adults, therefore, milk from the area is not safe for consumption. Cd would be transferred mainly through the soil (water)-grass-milk pathway, due to its presence in irrigation water and in fertilizers that contain Cd. The main pathway for Pb entry would be air-soil (water)-milk grass, from the fine particles emitted into the air by the mining-metallurgical activity, developed approximately 90 km from the study area.
Toxic Effects and Tumor Promotion Activity of Marine Phytoplankton Toxins: A Review
Authors: Pradhan Biswajita , Kim Hansol , Abassi Sofia , Ki Jang-Seu
Published: June 2022

Phytoplankton are photosynthetic microorganisms in aquatic environments that produce many bioactive substances. However, some of them are toxic to aquatic organisms via filter-feeding and are even poisonous to humans through the food chain. Human poisoning from these substances and their serious long-term consequences have resulted in several health threats, including cancer, skin disorders, and other diseases, which have been frequently documented. Seafood poisoning disorders triggered by phytoplankton toxins include paralytic shellfish poisoning (PSP), neurotoxic shellfish poisoning (NSP), amnesic shellfish poisoning (ASP), diarrheic shellfish poisoning (DSP), ciguatera fish poisoning (CFP), and azaspiracid shellfish poisoning (AZP). Accordingly, identifying harmful shellfish poisoning and toxin-producing species and their detrimental effects is urgently required. Although the harmful effects of these toxins are well documented, their possible modes of action are insufficiently understood in terms of clinical symptoms. In this review, we summarize the current state of knowledge regarding phytoplankton toxins and their detrimental consequences, including tumor-promoting activity. The structure, source, and clinical symptoms caused by these toxins, as well as their molecular mechanisms of action on voltage-gated ion channels, are briefly discussed. Moreover, the possible stress-associated reactive oxygen species (ROS)-related modes of action are summarized. Finally, we describe the toxic effects of phytoplankton toxins and discuss future research in the field of stress-associated ROS-related toxicity. Moreover, these toxins can also be used in different pharmacological prospects and can be established as a potent pharmacophore in the near future.