bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of Savonius Rotors Integrated into Control Valves for Energy Harvesting
Authors: Lv Kai , Xie Yudong , Zhang Xinbiao , Wang Yong
Published: October 2020

Integrating vertical-axis runners into ball valves for energy harvesting from pressurized pipes in water supply systems has become a promising scheme of self-supplying power (referred to as the “GreenValve” scheme). In addition to energy harvesting, the GreenValve configuration also has the function of fluid regulating, which makes a qualitative breakthrough in both structure and function. However, the runner specially used to match the ball valve has not been fully studied and designed. Hence, based on the traditional Savonius rotor, a modified semi-elliptical runner is proposed in this study. To better match the ball valve structurally, the roundness of the runner at blade tip position is improved and, thus, the initial runner configuration is obtained. Moreover, research on blade profile flatness and runner aspect ratio is conducted in FLUENT software to be more functionally compatible with the ball valve. Numerical results indicate that the GreenValve always performs best in terms of shaft power at 25% opening regardless of the aspect ratio and the flatness. When the flatness value is equal to 0.7, the GreenValve presents the maximum shaft power and the second highest flow coefficient which is only 1.9% lower than the maximum value. Comparison results of three models with different aspect ratios reveal that the model with the smallest aspect ratio has a slight reduction in flow capacity while a significant improvement in shaft power, reaching a maximum shaft power of 78.6W.
A Synthesis on the Effects of Two Commercial Recycled Plastics on the Properties of Bitumen and Asphalt
Authors: White Greg
Published: October 2020

The desire to develop sustainable infrastructure, including pavement structures and materials, is ever increasing in recent times. One opportunity is to partially replace high-cost bituminous binder with low-cost recycled plastic in asphalt mixtures. This synthesis combines the various research efforts to understand the effects of two commercially available recycled plastics, known as MR6 and MR10, on bituminous binders and asphalt mixtures. Using common test methods from the United Kingdom, the United States and Australia, generally consistent and significant effects were observed in various base bitumen grades and various common asphalt mixture types. Binder resistance to flow and binder elasticity both increased significantly and were associated with the three to four grade increases under the Performing Grading system. Similarly, mixture stiffness and mixture resistance to deformation increased significantly, while crack resistance and moisture damage resistance were not significantly affected. The effects of MR6 and MR10 were generally similar to the effects associated with conventional polymer modification of asphalt binders and asphalt mixtures, particularly those effects associated with plastomeric polymers.
Social Work during the COVID-19 Crisis: Responding to Urgent Social Needs
Authors: Redondo-Sama Gisela , Matulic Virginia , Munté-Pascual Ariadna , de Vicente Irene
Published: October 2020

Social work during the COVID-19 crisis has faced one of the most challenging times to cover urgent social needs in an uncertain scenario. This study analyzes the immediate responses in social work to vulnerable groups in the first 15 days of the pandemic in Barcelona, one of the most affected areas worldwide by COVID-19. The sample for this qualitative study includes 23 semi-structured interviews with social workers from different fields of intervention, from general approaches (primary care) to specific ones (health, ageing, homeless, and justice). The data analysis followed the communicative methodology, including transformative and exclusionary dimensions, and the analytical categories focused on the impact of the COVID-19 pandemic on social services users, the organizational responses of social workers, and the impact of the interventions to cover urgent social needs of attendees. The interventions have been accompanied by an improvement in communication channels with vulnerable groups, ensuring an understanding of the situation of families and individuals, and covering the most urgent social needs. The study shows the key role of social workers from diverse social attention tools and their contribution to the sustainability of social services with a long-term impact.
Do Board Gender Diversity and Non-Executive Directors Affect CSR Reporting? Insight from Agency Theory Perspective
Authors: Guping Cheng , Safdar Sial Muhammad , Wan Peng , Badulescu Alina , Badulescu Daniel , Vianna Brugni Talles
Published: October 2020

Our paper provides a valuable contribution by exploring the following complex phenomenon: Do board gender diversity and reputational incentives of non-executive directors affect corporate social responsibility(CSR) reporting? To this end, we use panel data regression (fixed effect) to examine the above relationship by using data from the 2009 to 2019 timeperiod, by using data from non-financial firms listed on the Shanghai Stock Exchange. To deal with the possibility of an endogeneity problem, we have used the two-stage least square (2SLS) regression model. Our empirical results suggest that board gender diversity positively affects CSR reporting. Our study has found that the reputational incentives of non-executive directors improve the CSR reporting. Furthermore, reputational incentives of non-executive directors (NEDs) and CSR reporting are moderated by firm size, this effect being stronger for large firms. Our findings also show that the firm size positively moderates the relationship between gender diversity in boards and CSR reporting. The control variables, namely board size, board member average tenure, leverage, “big 4” and return on assets, have an impact on the firm’s CSR reporting. Therefore, our results contribute towards new aspects in respect to the emerging literature concerning the system of non-executive directors, protection of stakeholder’s interests, and CSR reporting, especially as regards China. Furthermore, our results are robust as concerns alternative measures of variables under consideration.
Impacts of the BOPS Option on Sustainable Retailing
Authors: He Yi , Xu Qianqian , Zhao Da
Published: October 2020

This paper focuses on the value of an omnichannel retailing option, Buy-Online-and-Pick-up-in-Store (BOPS), in reducing environmental impact. Analytical models were established to explore the impacts of the BOPS strategy on the pricing and expected profit of the dual-channel retailer as well as the environment. The equilibrium solutions under dual-channel and omnichannel scenarios were obtained. Then, we considered the impact of loyal store consumers in the extended model. We find that the retailer will increase the product price after adopting the BOPS strategy. Our analytical results also show that when the operating cost of the BOPS strategy is relatively low, the total demand under the omnichannel scenario is greater than that under the dual-channel scenario and vice versa. In addition, this strategy can always reduce the environmental impact in terms of the pure online demand. Finally, when the operating cost is lower and the fraction of consumers without channel preference is higher, the retailer can benefit from the BOPS strategy. In this case, the BOPS strategy can achieve profit improvement and environmental impact reduction.
Goal-Driven or Data-Driven? Inventory of Sustainability Indicator Initiatives in Rural Canada
Authors: Lowery Brennan , Dagevos John , Vodden Kelly
Published: October 2020

This article seeks to address knowledge gaps on sustainability indicators (SIs) in rural and natural resource-dependent communities, considering how they are used to contextualize sustainable development priorities and support local governance. We build on recent scholarship on the potentials of SIs for stimulating societal transformation, extending this inquiry into rural and resource-based communities which have been under-represented in SI research. The governance challenges facing rural Canada, as well as its geographic and socio-economic diversity, provide a unique context for examining these issues. We provide relatively uncommon synthetic findings by compiling an inventory of SI initiatives across 39 rural communities and regions of Canada. Using the Community Capital Framework, we examine grey literature and academic publications related to each initiative spanning from 1999–2019 to determine the breadth of sustainable development priorities considered. Informed by collaborative and multi-level governance frameworks, we explore how these initiatives are used to support multi-stakeholder collective action. This article finds that rural Canadian SI initiatives prioritize socio-cultural capital, with relatively fewer economic and ecological indicators, while identifying a typology of SI use and inter-related governance dynamics informing how these priorities and indicators are determined. Although some initiatives display highly collaborative and bottom-up processes, many rural Canadian SI initiatives are characterized by a data-driven approach that, when met with local capacity gaps, fails to contextualize standardized datasets to reflect rural realities. We encourage more in-depth investigation of these findings and comparison of Canadian experiences to other jurisdictions.
Government Reward-Penalty Mechanism in Dual-Channel Closed-Loop Supply Chain
Authors: Chen Haitao , Dong Zhaohui , Li Gendao
Published: October 2020

This study establishs a dual channel closed-loop supply chain (CLSC) model under a government–penalty mechanism (RPM) consisting a dual-channel manufacturer, a retailer, and the government. We consider a Stackelberg game between the manufacturer and the retailer, and the government rewards or punishes manufacturers on the basis of the collection rate of used products. This paper analyzes the influence of government RPM on the optimal decisions, the relationship between the two sales channels, and the total social welfare of the supply chain system. We find that the government RPM can improve the stability of the dual-channel supply chain and the collection rate of the used products. Moreover, we are the first to provide a method of deriving the optimal government RPM through a numerical example.
Impact of the Information and Communication Technologies on Students with Disabilities. A Systematic Review 2009–2019
Authors: Sarasola Sánchez-Serrano José Luis , Jaén-Martínez Alicia , Montenegro-Rueda Marta , Fernández-Cerero José
Published: October 2020

This article provides a bibliographic review of studies undertaken between 2009–2019 regarding the use of Information and Communication Technologies (ICTs) to support the learning of students with disabilities, included in the following databases: Web of Science (WoS,) Scopus, ERIC, SciELO, and Google Scholar. Through a descriptive and quantitative methodology, and using bibliometric maps, the most significant data are presented according to their citation and repercussion index. The results show that ICTs are decisive for student with disabilities but there is evidence of a lack of training by teachers. In this regard, findings show that both the quantity of articles published in the different databases and the citations they receive have a medium-low impact index, as well as a low application of them.
Employee’s Corporate Social Responsibility Perception and Sustained Innovative Behavior: Based on the Psychological Identity of Employees
Authors: Li Yi-Bin , Zhang Gui-Qing , Wu Tung-Ju , Peng Chi-Lu
Published: October 2020

Corporate social responsibility refers to the voluntary promises made by an enterprise to achieve sustainable development. When enterprises conduct prosocial activities, they must consider the feelings of their employees including employees’ sense of identification and well-being. However, most existing corporate social responsibility studies have focused on the financial performance of enterprises; the effects of corporate social responsibility on employees have seldom been examined. Accordingly, this study conducted an empirical study examining the effects of employee perception of enterprise corporate social responsibility, employee well-being, and organizational identification on employee innovative behavior. A total of 431 valid questionnaires were retrieved. A structural equation modeling analysis revealed that a positive relationship exists between employee perception of enterprise execution of corporate social responsibility and employee innovative behavior. Furthermore, both employee well-being and organizational identification play mediating roles between the two variables. When conducting social responsibility activities, enterprises are suggested to inform their employees or even encourage their participation in their efforts to fulfill their social responsibility. Through interaction between internal and external stakeholders, substantial innovative behavior, beneficial for the subsequent development of enterprises, can be stimulated.
Public Participation in Smart-City Governance: A Qualitative Content Analysis of Public Comments in Urban China
Authors: Gao Zhe , Wang Siqin , Gu Jiang
Published: October 2020

Public participation is crucial in the process of urban governance in smart-city initiatives to enable urban planners and policy makers to take account of the real public needs. Our study aims to develop an analytical framework using citizen-centred qualitative data to analyse urban problems and identify the areas most needed for urban governance. Taking a Chinese megacity as the study area, we first utilise a web-crawling tool to retrieve public comments from an online comment board and employ the Baidu Application Programming Interfaces and a qualitative content analysis for data reclassification. We then analyse the urban problems reflected by negative comments in terms of their statistical and spatial distribution, and the associative factors to explain their formation. Our findings show that urban problems are predominantly related to construction and housing, and most frequently appear in industry-oriented areas and newly developed economic development zones on the urban fringe, where the reconciling of government-centred governance and private governance by real estate developers and property management companies is most needed. Areas with higher land prices and a higher proportion of aged population tend to have fewer urban problems, while various types of civil facilities affect the prevalence of urban problems differently.
Clays, Limestone and Biochar Affect the Bioavailability and Geochemical Fractions of Cadmium and Zinc from Zn-Smelter Polluted Soils
Authors: Lahori Altaf Hussain , Mierzwa-Hersztek Monika , Demiraj Erdona , Idir Rachida , Bui Thi Tuyet Xuan , Vu Dinh Duy , Channa Amanullah , Samoon Naeem Akhtar , Zhang Zengqiang
Published: October 2020

Ca-bentonite (CB) alone and in a mixture with limestone (L), tobacco biochar (TB) and zeolite (Z) on the fixation, geochemical fractions and absorption of Cd and Zn by Chinese cabbage in smelter heavily polluted (S-HP) and smelter low polluted (S-LP) soils were investigated. The results showed that the CB + TB and CB + L + TB treatments significantly immobilized Cd up to 22.0% and 29.7%, respectively, and reduced uptake by Chinese cabbage shoot to 36.0% with CB + Z + L and 61.3% with CB + L in S-HP and S-LP soils compared with the control. The CB + Z + L + TB treatment mobilized Cd up to 4.4% and increased absorption in the shoot by 9.9% in S-HP soil. The greatest immobilization of Zn was 53.2% and 58.2% with the CB + Z + L + TB treatment, which reduced Zn uptake in the plant shoot by 10.0% with CB + L and 58.0% with CB + Z + L + TB in S-HP and S-LP soils. The CB + Z + TB and CB + TB treatments mobilized Zn up to 35.4% and 4.9%, respectively, in both soils. Furthermore, the uptake of Zn in plant shoot was observed by 59.0% and 7.9% with application of CB + Z and CB + TB treatments, respectively, in S-HP and S-LP soils. Overall, our results suggest that Ca-bentonite alone and in mixtures with different amendments can be used to reduce the phyto-extraction of Cd and Zn in Zn-smelter polluted soils.
A Linked Open Data-Oriented Sustainable System for Transparency and Open Access to Government Data: A Case Study of the Public’s Response to Women’s Driving in Saudi Arabia
Authors: AlSukhayri Afnan MuhammadSalh , Aslam Muhammad Ahtisham , Saeedi Kawther , Malik Muhamad Sheraz Arshed
Published: October 2020

Due to the wide-ranging development of data-oriented sustainable systems in the government and the public sectors, the development of such sustainable systems is replete with potential. The ultimate focus of developing these sustainable systems is to provide citizens with transparency, accountability, awareness as well as a single point of query for asking integrated and smart queries. In view of these benefits, the Saudi government has taken the initiative to publish and develop sustainable open data-oriented information systems. However some major challenges in the Saudi Government Open Data are that the (1) data are published and available in different formats such as Excel sheets, CSV files (Comma Separated Values), images, scanned documents and social media sources such as Twitter, (2) datasets from different government departments are not linked with each other or to existing datasets in Linked Open Data Cloud (even though they have strong links with each other), and (3) there is no SPARQL Endpoint that can be used to pose smart semantic-based queries to Saudi Government Data. This paper is part of an ongoing research project to present a framework that can be used to transfer the government data from different sources to RDF format. The framework can also be used to clean and classify/map the data according to the Saudi Government Ontology. We also describe our approach for semiautomatically linking Saudi Government Datasets with one another as well as with other existing open datasets, thus resulting in the Saudi Linked Open Government Data Cloud (SLOGDC). Finally, taking the topic “Public’s Response to Women’s Driving in Saudi Arabia” as a case study, we demonstrate the SLOGD SPARQL Endpoint as a data-oriented system by executing different queries and analyzing results of these queries. This work also contributes new insights into women’s driving in Saudi Arabia using the SLOGDC, thus suggesting the way forward in shaping policies for decision-making.
Energy Engineering Approach for Rural Areas Cattle Farmers in Bangladesh to Reduce COVID-19 Impact on Food Safety
Authors: Nur-E-Alam Mohammad , Hoque Mohammad Nasirul , Ahmed Soyed Mohiuddin , Basher Mohammad Khairul , Das Narottam
Published: October 2020

This paper reports on the optimization of thin-film coating-assisted, self-sustainable, off-grid hybrid power generation systems for cattle farming in rural areas of Bangladesh. Bangladesh is a lower middle-income country with declining rates of poverty among its 160 million people due to persistent economic growth in conjunction with balanced agricultural improvements. Most of the rural households adopt a mixed farming system by cultivating crops and simultaneously rearing livestock. Among the animals raised, cattle are considered as the most valuable asset for the small-/medium-scale farmers in terms of their meat and milk production. Currently, along with the major health issue, the COVID-19 pandemic is hindering the world’s economic growth and has thrust millions into unemployment; Bangladesh is also in this loop. However, natural disasters such as COVID-19 pandemic and floods, largely constrain rural smallholder cattle farmers from climbing out of their poverty. In particular, small- and medium-scale cattle farmers face many issues that obstruct them from taking advantage of market opportunities and imposing a greater burden on their families and incomes. An appropriate measure can give a way to make those cattle farmers’ businesses both profitable and sustainable. Optimization of thin-film coating-assisted, self-sustainable, off-grid hybrid power generation system for cattle farming is a new and forward-looking approach for sustainable development of the livestock sector. In this study, we design and optimize a thin-film coating-assisted hybrid (photovoltaic battery generator) power system by using the Hybrid Optimization of Multiple Energy Resources (HOMER, Version 3.14.0) simulation tool. An analysis of the results has suggested that the off-grid hybrid system is more feasible for small- and medium-scale cattle farming systems with long-term sustainability to overcome the significant challenges faced by smallholder cattle farmers in Bangladesh.
Residential Mobility and Quality of Life between Metropolitan Areas: The Case of South Korea
Authors: Oh Jooseok
Published: October 2020

This study investigated the theory of residential mobility in terms of quality of life, focusing on convenience and the urban environment. The evaluation items (e.g., the accessibility to infrastructure, security, the environment, and social relationships) were selected based on previous studies, and a one-way ANOVA was conducted. The Korea Housing Survey was used to obtain data on the evaluations of homeowners who migrated to Seoul (the capital of South Korea) and to the surrounding metropolitan area (Gyeong-in). The regression analysis identified the factors affecting the overall satisfaction with the two destinations. The group that had migrated from Gyeong-in to Seoul was more satisfied with the medical, public, cultural, and transportation facilities than the group that had migrated from Seoul to Gyeong-in. Differences were also found between the two groups in the factors affecting their overall satisfaction with the migration destination. Factors such as satisfaction with transportation, commercial facilities, and cultural facilities affected the overall satisfaction with both destinations. However, homeownership affected the dependent variables only in Gyeong-in. The implications for potential improvements to infrastructure and housing distribution are discussed.
Assessment of Human Productivity Drivers for Construction Labor through Importance Rating and Risk Mapping
Authors: Gunduz Murat , Abu-Hijleh Abdulrahman
Published: October 2020

Labor constitutes a significant portion of the overall cost of a construction project, where labor productivity is often the main driver of the cost. Although studies on labor productivity factors exist, their frequency of occurrence in terms of their ranking remains unexplored. This study differs from other studies in the literature by introducing the frequency component to the productivity factors, a more realistic ranking of the factors by adjusting the importance by frequency (frequency adjusted importance index) and risk mapping of the factors. Moreover, this study is the first to apply risk mapping on labor productivity drivers. The aim of this paper is to identify the project factors affecting the labor productivity in construction projects and to rank these factors considering the perception of the industry on project performance. A literature review of past relevant studies was performed to identify and draft a list of factors affecting labor productivity in construction projects. Thirty-seven labor productivity factors were presented in a questionnaire to investigate the impact and frequency of their occurrence in construction projects. A 9-point scale structured questionnaire was constructed to measure the importance and the frequency of the factors and to evaluate the ranking for different categories. The frequency adjusted importance index (FAII), Spearman’s rank correlation, and risk mapping were used to study and analyze the 105 completed responses. The participants rated the following factors as the five most significant labor productivity-influencing factors: (1) poor labor supervision, (2) delays in payments, (3) poor work environment, (4) lowly skilled labor, and (5) bad weather conditions.
Efficient and Secure NFC Authentication for Mobile Payment Ensuring Fair Exchange Protocol
Authors: Thammarat Chalee
Published: October 2020

The standard protocol of near field communication (NFC) has concentrated primarily on the speed of communication while ignoring security properties. Message between an NFC-enabled smartphone and a point of sale are exchanged over the air (OTA), which is a message considered an authentication request for payment, billing, ticketing, loyalty services, identification or access control. An attacker who has an antenna can intercept or manipulate the exchanged messages to take advantage of these. In order to solve this problem, many researchers have suggested authentication methods for NFC communications. However, these remain inadequate transaction security and fairness. In this paper, we will propose a technique that ensures mutual authentication, security properties, and strong fairness. Mutual authentication is a security property that prevents replay attacks and man-in-the-middle attacks. Both fair exchange and transaction security are also significant issues in electronic transactions with regards to creating trust among the parties participating in the transaction. The suggested protocol deploys a secure offline session key generation technique to increase transaction security and, importantly, make our protocol lightweight while maintaining the fairness property. Our analysis suggests that our protocol is more effective than others regarding transaction security, fairness, and lightweight protocol. The proposed protocol checks robustness and soundness using Burrows, Abadi and Needham (BAN) logic, the Scyther tool, and automated validation of internet security protocols and applications (AVISPA) that provide formal proofs for security protocols. Furthermore, our protocol can resolve disputes in case one party misbehaves.
An Improved Level Set Method on the Multiscale Edges
Authors: Su Yao , He Kun , Wang Dan , Peng Tong
Published: October 2020

The level set method can segment symmetrical or asymmetrical objects in real images according to image features. However, the segmentation performance varies with feature scale. In order to improve the segmentation effect, we propose an improved level set method on the multiscale edges, which combines the level set method with image multi-scale decomposition to form a unified model. In this model, the segmentation relies on multiscale edges, and the multiscale edges depend on multiscale decomposition. A novel total variation regularization is proposed in multiscale decomposition to preserve edges. The multiscale edges obtained by the multiscale decomposition are integrated into the segmentation process, and the object can be easily extracted from a proper scale. Experimental results indicate that this method has superior performance in precision, recall and F-measure, compared with relative edge-based segmentation methods, and is insensitive to noise and inhomogeneous sub-regions.
Thermo-Hydraulic Performance Analysis on the Effects of Truncated Twisted Tape Inserts in a Tube Heat Exchanger
Authors: Ghalambaz Mehdi , Mashayekhi Ramin , Arasteh Hossein , Ali Hafiz Muhammad , Talebizadehsardari Pouyan , Yaïci Wahiba
Published: October 2020

This paper investigates the convective heat transfer in a heat exchanger equipped with twisted tape elements to examine effects of the twisted tape truncation percentage, pitch value, position and Reynolds number using 3D numerical simulation. A symmetric heat flux is applied around the tube as the studied heat exchanger. Based on the influences in both heat transfer enhancement and pressure drop, the performance evaluation criterion (PEC) is utilized. Inserting twisted tape elements and reducing the pitch value significantly augment the Nusselt number, friction coefficient and PEC number compared to the plain tube. For the best case with a Reynolds number of 1000, the average Nusselt number increases by almost 151%, which is the case of fully fitted twisted tape at a pitch value of L/4. Moreover, increasing the twisted tape truncation percentage reduces both heat transfer and pressure drop. Furthermore, the highest heat transfer rate is achieved when the truncated twisted tape is located at the entrance of the tube. Finally, it is concluded that for P = L, L/2, L/3 and L/4, the optimum cases from the viewpoint of energy conservation are twisted tapes with truncation percentages of 75, 50, 50 and 0%, in which the related PEC numbers at a Reynolds number of 1000 are almost equal to 1.08, 1.24, 1.4 and 1.76, respectively.
A Numerical Approach of a Time Fractional Reaction–Diffusion Model with a Non-Singular Kernel
Authors: Akram Tayyaba , Abbas Muhammad , Ali Ajmal , Iqbal Azhar , Baleanu Dumitru
Published: October 2020

The time–fractional reaction–diffusion (TFRD) model has broad physical perspectives and theoretical interpretation, and its numerical techniques are of significant conceptual and applied importance. A numerical technique is constructed for the solution of the TFRD model with the non-singular kernel. The Caputo–Fabrizio operator is applied for the discretization of time levels while the extended cubic B-spline (ECBS) function is applied for the space direction. The ECBS function preserves geometrical invariability, convex hull and symmetry property. Unconditional stability and convergence analysis are also proved. The projected numerical method is tested on two numerical examples. The theoretical and numerical results demonstrate that the order of convergence of 2 in time and space directions.
Integrable and Superintegrable Potentials of 2d Autonomous Conservative Dynamical Systems
Authors: Mitsopoulos Antonios , Tsamparlis Michael , Paliathanasis Andronikos
Published: October 2020

We consider the generic quadratic first integral (QFI) of the form I=Kab(t,q)q˙aq˙b+Ka(t,q)q˙a+K(t,q) and require the condition dI/dt=0. The latter results in a system of partial differential equations which involve the tensors Kab(t,q), Ka(t,q), K(t,q) and the dynamical quantities of the dynamical equations. These equations divide in two sets. The first set involves only geometric quantities of the configuration space and the second set contains the interaction of these quantities with the dynamical fields. A theorem is presented which provides a systematic solution of the system of equations in terms of the collineations of the kinetic metric in the configuration space. This solution being geometric and covariant, applies to higher dimensions and curved spaces. The results are applied to the simple but interesting case of two-dimensional (2d) autonomous conservative Newtonian potentials. It is found that there are two classes of 2d integrable potentials and that superintegrable potentials exist in both classes. We recover most main previous results, which have been obtained by various methods, in a single and systematic way.
User Behavior on Online Social Networks: Relationships among Social Activities and Satisfaction
Authors: Mican Daniel , Sitar-Tăut Dan-Andrei , Mihuţ Ioana-Sorina
Published: October 2020

Social networking sites (SNSs) are now ubiquitous communities for constant online interpersonal interactions that trigger symmetric or asymmetric effects on our everyday life. Recent studies advocate in favor of the significant role that SNSs have in promoting well-being and, more importantly, in disseminating reliable information during a global crisis, such as the current COVID-19 pandemic. Based on the growing importance of SNSs to the global framework, the main purpose of this study is to empirically assess the link between the use of symmetric social networks such as Facebook, or asymmetric social networks, like Instagram, and the level of satisfaction, employing the methodology of structural equation modeling. The results of the research validate the hypothesis that SNS activities increase the level of satisfaction, and therefore, that there is a direct link between the number of posts and comments and the level of satisfaction. Furthermore, based on the reversible and significant link between the level of satisfaction and the importance attributed to SNSs, the main conclusion of the study is that the higher the importance of the SNS, the greater the level of dissatisfaction experienced by users. Also, public activities on social networks positively affect social network satisfaction, while private activities have a direct negative relationship with the importance of social networks.
A Modulo Function-Based Robust Asymmetric Variable Data Hiding Using DCT
Authors: Khan Sahib , Khan Khalil , Arif Arslan , Hassaballah Mahmoud , Ali Jehad , Ta Qui Thanh Hoai , Yu Lisu
Published: October 2020

This work presents a new asymmetric data hiding technique that hides a variable number of secret message bits in the discrete cosine transform (DCT) coefficients of a cover image using a modular distance technique. Prior to data hiding, the proposed framework transforms a cover image from a spatial domain to various frequency coefficients using DCT. The DCT coefficients are arranged in two groups: one with low-frequency coefficient, and the other with the medium and high-frequency coefficients. The medium and higher frequency coefficients are processed for variable data hiding asymmetrically. The proposed technique hides variable sets of secret information bits in different coefficients. The variation in hidden secret information is maintained using a key developed based on the modulo of distance of a coefficient from the reference point. The same key is also used to retrieve the confidential information at the receiver ends. The results reveal that the presented framework does not create any visually significant distortion, and thus the hidden information does not attract the human visual system (HVS). The technique also results in high data hiding efficiency.
Evaluation of the Quality Supervision System for Construction Projects in China Considering the Quality Behavior Risk Transmission
Authors: Feng Jingchun , Wang Yuting , Zhang Ke
Published: October 2020

In construction projects, improper quality behavior of a participant results in quality behavior risks, which can transmit to the downstream participants and may cause detrimental effects on the quality of the entity finally constructed. Controlling the transmission of quality behavior risks is the key to effectively supervising and ensuring the quality of construction projects. In this study, the effectiveness of the quality supervision system of construction projects in China was investigated by considering the transmission of quality behavior risks. A multi-player evolutionary game model consisting of the players of quality supervision of a government department, upstream participant (UP), and downstream participant (DP) was generated. By using the system dynamics theory, the game model was simulated to determine the stability of the evolutionary system and to evaluate the effectiveness of China’s current quality supervision system under different scenarios. The results showed that there is no evolutionary stable strategy (ESS) in the evolutionary system of the current quality supervision system in China and there are fluctuations in the evolution process. It revealed that high risk exists in the current quality supervision system in China. To resolve the problem of the low efficiency of the current Chinese supervision system, a dynamic penalty and incentive method is developed, which has been proven to be able to effectively control the quality behavior risks in construction projects and hence ensuring the quality of the entity finally constructed.
Cost-Effective Placement of Recharging Stations in Drone Path Planning for Surveillance Missions on Large Farms
Authors: Fendji Jean Louis Ebongue Kedieng , Bayaola Israel Kolaigue , Thron Christopher , Fendji Marie Danielle , Förster Anna
Published: October 2020

The energy limitation remains one of the biggest constraints in drone path planning, since it prevents drones from performing long surveillance missions. To assist drones in such missions, recharging stations have recently been introduced. They are platforms where the drone can autonomously land to recharge its battery before continuing the mission. However, the cost of those platforms remains a significant obstacle to their adoption. Consequently, it is important to reduce their number while planning the path of the drone. This work introduces the Single Drone Multiple Recharging Stations on Large Farm problem (SD-MRS-LF). A large farm is considered as an area of interest to cover with a set of candidate locations where recharging stations can be installed. The aim is to determine the path of the drone that minimizes the number of locations for recharging stations as well as the completion time of the surveillance mission. This path planning problem falls within the realm of computational geometry and is related to similar problems that are encountered in the field of robotics. The problem is complicated due to environmental constraints on farms such as wind speed and direction, which produce asymmetries in the optimal solution. A back-and-forth-k-opt simulated annealing (BFKSA) approach is proposed to solve the defined problem. The new approach is compared to the basic back-and-forth (BF) and a K-opt variant of the well-known simulated annealing (KSA) approach over a set of 20 random topologies in different environmental conditions. The results from computational experiments show that the BFKSA approach outperforms the others, in terms of providing feasible solutions and minimizing the number of recharges.
Blockchain Platforms and Access Control Classification for IoT Systems
Authors: Abdi Adam Ibrahim , Eassa Fathy Elbouraey , Jambi Kamal , Almarhabi Khalid , AL-Ghamdi Abdullah Saad AL-Malaise
Published: October 2020

The Internet of Things paradigm is growing rapidly. In fact, controlling this massive growth of IoT globally raises new security and privacy issues. The traditional access control mechanisms provide security to IoT systems such as DAC (discretionary access control) and mandatory access control (MAC). However, these mechanisms are based on central authority management, which raises some issues such as absence of scalability, single point of failure, and lack of privacy. Recently, the decentralized and immutable nature of blockchain technology integrated with access control can help to overcome privacy and security issues in the IoT. This paper presents a review of different access control mechanisms in IoT systems. We present a comparison table of reviewed access control mechanisms. The mechanisms’ scalability, distribution, security, user-centric, privacy and policy enforcing are compared. In addition, we provide access control classifications. Finally, we highlight challenges and future research directions in developing decentralized access control mechanisms for IoT systems.
Strength, Jumping and Change of Direction Speed Asymmetries in Soccer, Basketball and Tennis Players
Authors: Šarabon Nejc , Smajla Darjan , Maffiuletti Nicola A. , Bishop Chris
Published: October 2020

Despite growing research in the field of inter-limb asymmetries (ILAs), little is known about the variation of ILAs in different populations of athletes. The purpose of this study was to compare ILAs among young basketball, soccer and tennis players. ILAs were assessed in three different types of tests (strength, jumping and change of direction (CoD) speed), each including different tasks: (1) bilateral and unilateral counter movement jump, (2) isometric strength of knee extensors (KE) and knee flexors (KF), and (3) 90° and 180° CoD. Generally, the absolute metrics showed strong reliability and revealed significant differences (p < 0.05) among the three groups in KE maximal torque, KE and KF rate of force development and in both CoD tests. For jumping ILAs, power and force impulse metrics exhibited significant between-limb differences between groups, compared to jump height. For strength and CoD speed ILAs, only KF maximal torque and 180° CoD exhibited significant differences between groups. Greater KF strength ILAs in soccer players and counter-movement jump ILAs in tennis players are most probably the result of sport-specific movement patterns and training routines. Sport practitioners should be aware of the differences in ILAs among sports and address training programs accordingly.
Multiperiod Transfer Synchronization for Cross-Platform Transfer in an Urban Rail Transit System
Authors: Cao Nan , Tang Tao , Gao Chunhai
Published: October 2020

Transfer synchronization is an important issue in timetable scheduling for an urban rail transit system, especially a cross-platform transfer. In this paper, we aim to optimize the performance of transfer throughout the daily operation of an urban rail transit system. The daily operation is divided into multiple time periods and each time period has a specific headway to fulfill time varied passenger demand. At the same time, the turn-back process of trains should also be considered for a real operation. Therefore, our work enhances the base of the transfer synchronization model taking into account time-dependent passenger demand and utilization of trains. A mixed integer programming model is developed to obtain an optimal timetable, providing a smooth transfer for cross-transfer platform and minimizing the transfer waiting time for all transfer passengers from different directions with consideration of timetable symmetry. By adjusting the departure time of trains based on a predetermined timetable, this transfer optimization model is solved through a genetic algorithm. The proposed model and algorithm are utilized for a real transfer problem in Beijing and the results demonstrate a significant reduction in transfer waiting time.
An Analysis of the KDD99 and UNSW-NB15 Datasets for the Intrusion Detection System
Authors: Al-Daweri Muataz Salam , Zainol Ariffin Khairul Akram , Abdullah Salwani , Md. Senan Mohamad Firham Efendy
Published: October 2020

The significant increase in technology development over the internet makes network security a crucial issue. An intrusion detection system (IDS) shall be introduced to protect the networks from various attacks. Even with the increased amount of works in the IDS research, there is a lack of studies that analyze the available IDS datasets. Therefore, this study presents a comprehensive analysis of the relevance of the features in the KDD99 and UNSW-NB15 datasets. Three methods were employed: a rough-set theory (RST), a back-propagation neural network (BPNN), and a discrete variant of the cuttlefish algorithm (D-CFA). First, the dependency ratio between the features and the classes was calculated, using the RST. Second, each feature in the datasets became an input for the BPNN, to measure their ability for a classification task concerning each class. Third, a feature-selection process was carried out over multiple runs, to indicate the frequency of the selection of each feature. From the result, it indicated that some features in the KDD99 dataset could be used to achieve a classification accuracy above 84%. Moreover, a few features in both datasets were found to give a high contribution to increasing the classification’s performance. These features were present in a combination of features that resulted in high accuracy; the features were also frequently selected during the feature selection process. The findings of this study are anticipated to help the cybersecurity academics in creating a lightweight and accurate IDS model with a smaller number of features for the developing technologies.
Solving the Asymmetry Multi-Objective Optimization Problem in PPPs under LPVR Mechanism by Bi-Level Programing
Authors: Liu Feiran , Liu Jun , Yan Xuedong
Published: October 2020

Optimizing the cost and benefit allocation among multiple players in a public-private partnership (PPP) project is recognized to be a multi-objective optimization problem (MOP). When the least present value of revenue (LPVR) mechanism is adopted in the competitive procurement of PPPs, the MOP presents asymmetry in objective levels, control variables and action orders. This paper characterizes this asymmetrical MOP in Stackelberg theory and builds a bi-level programing model to solve it in order to support the decision-making activities of both the public and private sectors in negotiation. An intuitive algorithm based on the non-dominated sorting genetic algorithm III (NSGA III) framework is designed to generate Pareto solutions that allow decision-makers to choose optimal strategies from their own criteria. The effectiveness of the model and algorithm is validated via a real case of a highway PPP project. The results reveal that the PPP project will be financially infeasible without the transfer of certain amounts of exterior benefits into supplementary income for the private sector. Besides, the strategy of transferring minimum exterior benefits is more beneficial to the public sector than to users.
Gravitating Bubbles of Gluon Plasma above Deconfinement Temperature
Authors: Brihaye Yves , Buisseret Fabien
Published: October 2020

The equation of state of SU(3) Yang–Mills theory can be modelled by an effective Z3−symmetric potential depending on the temperature and on a complex scalar field ϕ. Allowing ϕ to be dynamical opens the way to the study of spatially localized classical configurations of the scalar field. We first show that spherically symmetric static Q-balls exist in the range (1−1.21)×Tc, Tc being the deconfinement temperature. Then we argue that Q-holes solutions, if any, are unphysical within our framework. Finally, we couple our matter Lagrangian to Einstein gravity and show that spherically symmetric static boson stars exist in the same range of temperature. The Q-ball and boson-star solutions we find can be interpreted as “bubbles” of deconfined gluonic matter; their mean radius is always smaller than 10 fm.
On Schwarzschild’s Interior Solution and Perfect Fluid Star Model
Authors: Barletta Elisabetta , Dragomir Sorin , Esposito Francesco
Published: October 2020

We solve the boundary value problem for Einstein’s gravitational field equations in the presence of matter in the form of an incompressible perfect fluid of density ρ and pressure field p(r) located in a ball r≤r0. We find a 1-parameter family of time-independent and radially symmetric solutions ga,ρa,pa:−2m<a<a1 satisfying the boundary conditions g=gS and p=0 on r=r0, where gS is the exterior Schwarzschild solution (solving the gravitational field equations for a point mass M concentrated at r=0) and containing (for a=0) the interior Schwarzschild solution, i.e., the classical perfect fluid star model. We show that Schwarzschild’s requirement r0>9κM/(4c2) identifies the “physical” (i.e., such that pa(r)≥0 and pa(r) is bounded in 0≤r≤r0) solutions {pa:a∈U0} for some neighbourhood U0⊂(−2m,+∞) of a=0. For every star model {ga:a0<a<a1}, we compute the volume V(a) of the region r≤r0 in terms of abelian integrals of the first, second, and third kind in Legendre form.
Symmetric Identities for Carlitz’s Type Higher-Order (p,q)-Genocchi Polynomials
Authors: Kim Ahyun , Ryoo Cheon Seoung
Published: October 2020

In this paper, we study Carlitz’s type higher-order (p,q)-Genocchi polynomials. To be specific, we define Carlitz’s type higher-order (p,q)-Genocchi polynomials and Carlitz’s type higher-order (h,p,q)-Genocchi polynomials. This paper also explores properties including distribution relation and symmetric identities. In addition, we find alternating (p,q)-power sums. We identify symmetric identities using Carlitz’s type higher-order (h,p,q)-Genocchi polynomials and alternating (p,q)-power sums.