bluuebunny/crossref_metadata_2025 huggingface dataset:
Optical OFDM for SiPM-Based Underwater Optical Wireless Communication Links
Authors: Essalih Taha , Khalighi Mohammad Ali , Hranilovic Steve , Akhouayri Hassan
Published: October 2020

Underwater optical wireless systems have dual requirements of high data rates and long ranges in harsh scattering and attenuation conditions. In this paper, we investigate the advantages and limitations of optical orthogonal frequency-division multiplexing (O-OFDM) signaling when a silicon photo-multiplier (SiPM) is used at the receiver in order to ensure high sensitivity. Considering a light-emitting diode (LED) transmitter and taking into account the limited dynamic range imposed by the transmitter and the SiPM receiver, we study the performance of three popular O-OFDM schemes, i.e., DC-biased, asymmetrically-clipped, and layered asymmetrically-clipped O-OFDM (DCO-, ACO-, and LACO-OFDM, respectively). We consider a constraint on transmit electrical power PTxe and take into account the required DC bias for the three considered schemes in practice, showing the undeniable advantage of ACO- and LACO-OFDM in terms of energy efficiency. For instance, for the considered SiPM and LED components, a spectral efficiency of ∼1 bps/Hz with a data rate of 20 Mbps, a link range of 70 m, and a target bit-error-rate (BER) of 10−3, ACO and LACO allow a reduction of about 10 and 6 mW, respectively, in the required PTxe, compared to DCO-OFDM. Meanwhile, we show that when relaxing the PTxe constraint, DCO-OFDM offers the largest operational link range within which a target BER can be achieved. For instance, for a target BER of 10−3 and a data rate of 20 Mbps, and considering PTxe of 185, 80, and 50 mW for DCO-, LACO-, and ACO-OFDM, respectively, the corresponding intervals of operational link range are about 81, 74.3, and 73.8 m. Lastly, we show that LACO-OFDM makes a good compromise between energy efficiency and operational range flexibility, although requiring a higher computational complexity and imposing a longer latency at the receiver.
Detection and Quantification of Tomato Paste Adulteration Using Conventional and Rapid Analytical Methods
Authors: Vitalis Flora , Zaukuu John-Lewis Zinia , Bodor Zsanett , Aouadi Balkis , Hitka Géza , Kaszab Timea , Zsom-Muha Viktoria , Gillay Zoltan , Kovacs Zoltan
Published: October 2020

Tomato, and its concentrate are important food ingredients with outstanding gastronomic and industrial importance due to their unique organoleptic, dietary, and compositional properties. Various forms of food adulteration are often suspected in the different tomato-based products causing major economic and sometimes even health problems for the farmers, food industry and consumers. Near infrared (NIR) spectroscopy and electronic tongue (e-tongue) have been lauded as advanced, high sensitivity techniques for quality control. The aim of the present research was to detect and predict relatively low concentration of adulterants, such as paprika seed and corn starch (0.5, 1, 2, 5, 10%), sucrose and salt (0.5, 1, 2, 5%), in tomato paste using conventional (soluble solid content, consistency) and advanced analytical techniques (NIR spectroscopy, e-tongue). The results obtained with the conventional methods were analyzed with univariate statistics (ANOVA), while the data obtained with advanced analytical methods were analyzed with multivariate methods (Principal component analysis (PCA), linear discriminant analysis (LDA), partial least squares regression (PLSR). The conventional methods were only able to detect adulteration at higher concentrations (5–10%). For NIRS and e-tongue, good accuracies were obtained, even in identifying minimal adulterant concentrations (0.5%). Comparatively, NIR spectroscopy proved to be easier to implement and more accurate during our evaluations, when the adulterant contents were estimated with R2 above 0.96 and root mean square error (RMSE) below 1%.
Mapping and Discriminating Rural Settlements Using Gaofen-2 Images and a Fully Convolutional Network
Authors: Ye Ziran , Si Bo , Lin Yue , Zheng Qiming , Zhou Ran , Huang Lu , Wang Ke
Published: October 2020

New ongoing rural construction has resulted in an extensive mixture of new settlements with old ones in the rural areas of China. Understanding the spatial characteristic of these rural settlements is of crucial importance as it provides essential information for land management and decision-making. Despite a great advance in High Spatial Resolution (HSR) satellite images and deep learning techniques, it remains a challenging task for mapping rural settlements accurately because of their irregular morphology and distribution pattern. In this study, we proposed a novel framework to map rural settlements by leveraging the merits of Gaofen-2 HSR images and representation learning of deep learning. We combined a dilated residual convolutional network (Dilated-ResNet) and a multi-scale context subnetwork into an end-to-end architecture in order to learn high resolution feature representations from HSR images and to aggregate and refine the multi-scale features extracted by the aforementioned network. Our experiment in Tongxiang city showed that the proposed framework effectively mapped and discriminated rural settlements with an overall accuracy of 98% and Kappa coefficient of 85%, achieving comparable and improved performance compared to other existing methods. Our results bring tangible benefits to support other convolutional neural network (CNN)-based methods in accurate and timely rural settlement mapping, particularly when up-to-date ground truth is absent. The proposed method does not only offer an effective way to extract rural settlement from HSR images but open a new opportunity to obtain spatial-explicit understanding of rural settlements.
An Analysis of the Eurasian Tectonic Plate Motion Parameters Based on GNSS Stations Positions in ITRF2014
Authors: Jagoda Marcin , Rutkowska Miłosława
Published: October 2020

The article is the fourth part of our research program concerning an analysis of tectonic plates’ motion parameters that is based on an observation campaign of an array of satellite techniques: SLR, DORIS, VLBI, and now GNSS. In this paper, based on the International Terrestrial Reference Frame 2014 (ITRF2014) for observations and using the GNSS technique, the Eurasian tectonic plate motion was analyzed and the plate motion parameters Φ, Λ (the position of the rotation pole), and ω (the angular rotation speed) were adjusted. Approximately 1000 station positions and velocities globally were obtained from the GNSS campaign over a 21-year time interval and used in ITRF2014. Due to the large number of data generated using this technique, the analyses were conducted separately for each tectonic plate. These baseline data were divided into a number of parts related to the Eurasian plate, and are shown in this paper. The tectonic plate model was analyzed on the basis of approximately 130 GNSS station positions. A large number of estimated station positions allowed a detailed study to be undertaken. Stations that agree with the plate motion were selected and plate parameters were estimated with high accuracy. In addition, stations which did not agree with the tectonic plate motion were identified and removed. In the current paper, the influence of the number and location of stations on the computed values and accuracy of the tectonic plate motion parameters is discussed. Four calculation scenarios are examined. Each scenario contains 30 stations for the common solution of the European and Asiatic part of the Eurasian plate. The maximum difference between the four calculation scenarios is 0.31° for the Φ parameter and 0.24° for the Λ parameter, indicating that it is at the level of the value of the formal error. The ω parameter has the same value for all the scenarios. The final stage of the analysis is the estimation of parameters Φ, Λ, and ω based on all of the 120 stations used in the four calculation scenarios (i.e., scenario 1 + scenario 2 + scenario 3 + scenario 4). The following results are obtained: Φ = 54.81° ± 0.37°, Λ = 261.04° ± 0.48°, and ω = 0.2585°/Ma ± 0.0025°/Ma. The results of the analysis are compared with the APKIM2005 model and another solution based on the GNSS technique, and a good agreement is found.
Random Fiber Grating Characterization Based on OFDR and Transfer Matrix Method
Authors: Zhou Zichao , Chen Chen , Lu Ping , Mihailov Stephen , Chen Liang , Bao Xiaoyi
Published: October 2020

Random fiber gratings (RFGs) have shown great potential applications in fiber sensing and random fiber lasers. However, a quantitative relationship between the degree of randomness of the RFG and its spectral response has never been analyzed. In this paper, two RFGs with different degrees of randomness are first characterized experimentally by optical frequency domain reflectometry (OFDR). Experimental results show that the high degree of randomness leads to low backscattering strength of the grating and strong strength fluctuations in the spatial domain. The local spectral response of the grating exhibits multiple peaks and a large peak wavelength variation range when its degree of randomness is high. The linewidth of its fine spectrum structures shows scaling behavior with the grating length. In order to find a quantitative relationship between the degree of randomness and spectrum property of RFG, entropy was introduced to describe the degree of randomness induced by period variation of the sub-grating. Simulation results showed that the average reflectivity of the RFG in dB scale decreased linearly with increased sub-grating entropy, when the measured wavelength range was smaller than the peak wavelength variation range of the sub-grating. The peak reflectivity of the RFG was determined by κ2LΔP (where κ is the coupling coefficient, L is the grating length, ΔP is period variation range of the sub-grating) rather than κL when ΔP is larger than 8 nm in the spatial domain. The experimental results agree well with the simulation results, which helps to optimize the RFG manufacturing processes for future applications in random fiber lasers and sensors.
A Novel Method with Stacking Learning of Data-Driven Soft Sensors for Mud Concentration in a Cutter Suction Dredger
Authors: Wang Bin , Fan Shi-dong , Jiang Pan , Zhu Han-hua , Xiong Ting , Wei Wei , Fang Zhen-long
Published: October 2020

The dredger construction environment is harsh, and the mud concentration meter can be damaged from time to time. To ensure that the dredger can continue construction operations when the mud concentration meter is damaged, the development of a dredger with advantages of low price and simple operation that can be used in emergency situations is essential. The characteristic spare mud concentration meter is particularly critical. In this study, a data-driven soft sensor method is proposed that can predict the mud concentration in real time and can mitigate current marine mud concentration meter malfunctions, which affects continuous construction. This sensor can also replace the mud concentration meter when the construction is stable, thereby extending its service life. The method is applied to two actual construction cases, and the results show that the stacking generalization (SG) model has a good prediction effect in the two cases, and its goodness of fit R2 values are as high as 0.9774 and 0.9919, indicating that this method can successfully detect the mud concentration.
Guitar Chord Sensing and Recognition Using Multi-Task Learning and Physical Data Augmentation with Robotics
Authors: Byambatsogt Gerelmaa , Choimaa Lodoiravsal , Koutaki Gou
Published: October 2020

In recent years, many researchers have shown increasing interest in music information retrieval (MIR) applications, with automatic chord recognition being one of the popular tasks. Many studies have achieved/demonstrated considerable improvement using deep learning based models in automatic chord recognition problems. However, most of the existing models have focused on simple chord recognition, which classifies the root note with the major, minor, and seventh chords. Furthermore, in learning-based recognition, it is critical to collect high-quality and large amounts of training data to achieve the desired performance. In this paper, we present a multi-task learning (MTL) model for a guitar chord recognition task, where the model is trained using a relatively large-vocabulary guitar chord dataset. To solve data scarcity issues, a physical data augmentation method that directly records the chord dataset from a robotic performer is employed. Deep learning based MTL is proposed to improve the performance of automatic chord recognition with the proposed physical data augmentation dataset. The proposed MTL model is compared with four baseline models and its corresponding single-task learning model using two types of datasets, including a human dataset and a human combined with the augmented dataset. The proposed methods outperform the baseline models, and the results show that most scores of the proposed multi-task learning model are better than those of the corresponding single-task learning model. The experimental results demonstrate that physical data augmentation is an effective method for increasing the dataset size for guitar chord recognition tasks.
Livestock Manure and the Impacts on Soil Health: A Review
Authors: Rayne Natasha , Aula Lawrence
Published: October 2020

Soil health is the capacity of the soil to provide an environment for optimum growth and development of plants, while also ensuring the health of animals and humans. Animal manure has been used for centuries as a source of nutrients in agriculture. However, many other soil properties that contribute to soil health are affected when manure is applied. Bulk density, aggregate stability, infiltration, water holding capacity, soil fertility, and biological properties are impacted to various degrees with manure application. The goal of this paper was to compile the research findings on the effects of various livestock manure types on soil fertility, soil physical properties, soil biology and the yield of various cereal crops. Specifically, this paper summarizes results for poultry, cattle, and swine manure used in various cropping systems. Although there are conflicting results in the literature with regards to the effect of manure on various soil properties, the literature offers convincing evidence of beneficial impacts of manure on soil and the growth of crops. The degree to which manure affects soil depends on the physical and chemical properties of the manure itself and various management and environmental factors including rate and timing of application, soil type, and climate.
Short-Term Detraining Does Not Impair Strength, Speed, and Power Performance in Elite Young Soccer Players
Authors: Pereira Lucas A. , Freitas Tomás T. , Pivetti Bruno , Alcaraz Pedro E. , Jeffreys Ian , Loturco Irineu
Published: October 2020

This study aimed to examine the effects of short-term detraining on the strength, speed, and jump capacities of under-20 soccer players. Twenty-four elite under-20 soccer players from the same professional club were assessed pre and post 26 days of detraining. The measurements were performed in the following order: countermovement jump (CMJ); 10 m linear sprint velocity; and one-repetition maximum test (1RM) in the horizontal leg-press exercise. To analyze the differences between pre- and post-tests, a paired T-test was applied. The significance level was set as p < 0.05. Soccer players exhibited a significant increase in CMJ performance (p = 0.02) and no significant differences in 10 m sprint velocity and 1RM leg-press were found after the short-term training cessation (p = 0.61; p = 0.55, respectively). We demonstrated that a short-term detraining period was capable of promoting a significant increase in the vertical jump height without inducing negative effects on the strength and speed capabilities of elite under-20 soccer players. Practitioners and sport scientists should be aware of these findings to program more effective training strategies at the beginning of the subsequent training cycle.
Multi-Objective Optimization Model for P + R and K + R Facilities’ Collaborative Layout Decision
Authors: Wang Wei , Sun Zhentian , Wang Zhiyuan , Liu Yue , Chen Jun
Published: October 2020

In order to reduce the pressure on urban road traffic, multi-modal travel is gradually replacing single-modal travel. Park and ride (P + R) and kiss and ride (K + R) are effective methods to integrate car transportation and rail transit. However, there is often an imbalance between supply and demand in existing car occupant transfer facilities, which include both P + R and K + R facilities. Therefore, we aim to conduct a research on P + R and K + R facilities’ collaborative decision. It first classifies car occupant transfer facilities into types and levels and sets the service capacity of each category. On the premise of ensuring the occupancy of parking spaces, our model aims to maximize the intercepted vehicle mileage and transfer utility and establishes an optimal decision model for car occupant transfer facilities. The model collaboratively decides the facilities in terms of location selection, layout arrangement, and overflow demand conversion to balance the supply and demand. We choose Chengdu as an example, apply the multi-objective optimization model of car occupant transfer facilities, give improved schemes, and further explore the influence of the quantity of facilities on the optimization objectives. The results show that the scheme obtained by the proposed model is significantly better than the existing scheme.
Introduction to Special Issue “Advances in Sustainability-Oriented Innovations”
Authors: González-Álvarez Nuria , Cabeza-García Laura
Published: October 2020

This Special Issue focuses on the study of Sustainability-Oriented Innovations (SOIs). Our purpose is to shed light on the SOIs literature regarding their determining factors, implications and new challenges for the future. In this editorial, we are delighted to present the three papers included in this Special Issue. Each of them tackles different issues related to SOIs having important academic and managerial implications. Two papers analyze the influence of SOIs on urban development and resource productivity, respectively, and the third studies SOIs determinants, in particular, cooperation networks. Moreover, two of the papers analyze SOIs considering territory (cities or countries) as their unit of analysis while the third focuses on firms. This denotes that SOIs’ actions are important whatever the level of analysis and as either a determinant or a consequence.
Contingent Decision of Corporate Environmental Responsibility Based on Uncertain Economic Policy
Authors: Yang Jieqiong , Luo Panzhu , Tan Yong
Published: October 2020

Using 522 nonfinancial listed companies on the Chinese A-share Market during 2008–2016 as the sample, this paper studies the discretion of corporations to fulfill their environmental responsibilities in the face of economic policy uncertainty (EPU) through a panel regression model and a panel quantile regression model. Additionally, the sample is classified and the heterogeneity is analyzed based on the equity nature, the financing constraints and the economic region in which the corporations are located. The conclusions are as follows. First, faced with EPU, the corporations are willing to actively undertake environmental responsibilities, but their marginal propensity to these responsibilities shows a downward trend. Second, under the premise of EPU, the decision-making behavior of different types of corporations to fulfill their environmental responsibilities is heterogeneous, which is embodied in the equity nature, financing constraints and economic region. Third, through the stepwise regression method, this paper further studies the impact mechanism, and finds that the enterprise’s leverage ratio plays a partial mediating role in the relationship between EPU and environmental responsibility of nonfinancial corporations. Our paper provides important policy implications for the government. In the process of requiring corporations to fulfill their environmental responsibilities, relevant government organizations should fully consider the impact of EPU on the corporations’ development, and the level of environmental responsibilities should be controlled based on the type of the corporation. We further suggest that the requirement should be imposed on the corporations to disclose high-quality and reliable environmental protection information. Finally, we recommend that the corporations should adhere to the route of sustainable development.
Concepts of Development of Alternative Travel in Autonomous Cars
Authors: Palevičius Vytautas , Ušpalytė-Vitkūnienė Rasa , Damidavičius Jonas , Karpavičius Tomas
Published: October 2020

Autonomous car travel planning is increasingly gaining attention from scientists and professionals, who are addressing the integration of autonomous cars into the general urban transportation system. Autonomous car travel planning depends on the transport system infrastructure, the dynamic data, and their quality. The efficient development of travel depends on the development level of the Intelligent Transport Systems (ITS) and the Cooperative Intelligent Transport Systems (C-ITS). Today, most cities around the world are competing with each other to become the smartest cities possible, using and integrating the most advanced ITS and C-ITS that are available. It is clear that ITS and C-ITS are occupying an increasing share of urban transport infrastructure, so the complex challenges of ITS and C-ITS development will inevitably need to be addressed, in the near future, by integrating them into the overall urban transport system. With this in mind, the authors proposed three autonomous car travel development concepts that should become a conceptual tool in the development of ITS and C-ITS.
Investigation on the Coupling Coordination Relationship between Electric Power Green Development and Ecological Civilization Construction in China: A Case Study of Beijing
Authors: Chai Jianxue , Zhang Lihui , Yang Meng , Nie Qingyun , Nie Lei
Published: October 2020

In the context of ecological civilization construction (ECC) and energy revolution strategy, there are many studies on ECC or electric power green development (EPGD). However, EPGD and ECC influence each other and are closely related, and there are few studies on the development relationship of EPGD and ECC. Therefore, this paper aims to study the coupling coordination relationship between EPGD and ECC to make them develop in harmony. Firstly, an evaluation index system of EPGD and ECC for their coupling coordination relationship is proposed. Then, this paper combines the coupling coordination degree model (CCDM), improved analytic hierarchy process (AHP) based on cloud model, and regression model to propose a coupling coordination relationship analysis model for EPGD and ECC. The improved AHP based on cloud model can fully reflect the will of decision-makers and effectively deal with the ambiguity and randomness of weight judgment. Finally, this paper conducts an empirical study on Beijing and verifies the applicability of the model proposed in this study. Policy recommendations to promote EPGD and ECC are proposed based on weight analysis, coupling coordination degree (CCD) analysis and regression analysis. This paper provides tools for the study on policies related to power development and ecological civilization.
Understanding the Tourists’ Perspective of Sustainability in Cultural Tourist Destinations
Authors: Aydın Begüm , Alvarez Maria D.
Published: October 2020

Considering the tourists’ viewpoint when creating a sustainable destination is crucial since marketing may be the driving force behind many sustainability initiatives. However, most of the literature has followed a supply-based perspective, ignoring the way that tourists view sustainability attributes. Therefore, this research attempts to address this gap in the literature by analyzing tourists’ perceptions concerning sustainability attributes in tourist destinations. This research aims to determine which of these traits are seen as most important by the tourists and to ascertain their willingness to pay for these aspects. The study is quantitative, based on an online questionnaire administered to Turkish cultural tourists. Exploratory and confirmatory factor analyses are used to obtain insights into how tourists consider sustainability aspects in tourist destinations. Thus, this research concludes that tourists view sustainability from a more varied perspective than that embraced by the classic definition of the concept, which comprises economic, environmental and socio-cultural dimensions. The findings of the study also determine that tourists favor sustainability attributes that are instrumental in enhancing their own tourist experiences. This information may be useful for destinations, providing guidance about how to market sustainable tourist destinations and encourage responsible tourism choices.
Viability of a Single-Stage Unsaturated-Saturated Granular Activated Carbon Biofilter for Greywater Treatment
Authors: Sharaf Ahmed , Guo Bing , Shoults David C. , Ashbolt Nicholas J. , Liu Yang
Published: October 2020

Compared with conventionally collected sewage, source-diverted greywater has a higher potential for on-site treatment and reuse due to its lower contaminant levels and large volume. A new design of granular activated carbon (GAC) biofilters was developed by incorporating unsaturated and saturated zones in a single stage to introduce an efficient, passive, and easy-to-operate technology for greywater on-site treatment at the household scale. The design was customized for its intended application considering various aspects including the reactor’s configuration, packing media, and feeding strategy. With the highest hydraulic and organic loadings of 1.2 m3 m−2 d−1 and 3.5 kg COD m−2 d−1, respectively, and the shortest retention time of 2.4 h, the system maintained an average total chemical oxygen demand removal rate of 94% with almost complete removal of nutrients throughout its 253 days of operation. The system showed a range of reduction efficacy towards five surrogates representing viruses, bacteria, and Cryptosporidium and Giardia (oo)cysts. A well-functioning biofilm was successfully developed, and its mass and activity increased over time with the highest values observed at the top layers. The key microbes within the biofilter were revealed. Feasibility of the proposed technology was investigated, and implications for design and operation were discussed.
Ecological Management Accounting—Taking into Account Sustainability, Does Accounting Have Far to Travel?
Authors: Kelsall Chris A.
Published: October 2020

Concerns regarding the development of environmental accounting have been around for decades. This work is an update to some of the previous questions around the development of ecological accounting to see how this has changed over the last two decades. The work is based on a systematic review of two journal articles from separate accounting journals. The two articles are by widely published academics and are formative ecological management accounting papers highlighting issues since 2000. The analysis includes a comparative review of the two articles, a review of successive articles in the journals, and a citation analysis. The first general finding is around the complex and confusing terminology that is still used, exemplified in the amorphous term sustainability. Specific findings from the paper analysis include ecological management accounting requires a fundamental change to organization management, different values exploring relationships such as material flows, inclusive of the living and physical world, with a longer time horizon, and a centrality of external factors. Due to these challenges, ecological management accounting is presently not used as a research category and therefore is an un-developed research domain. Environmental accounting is a more commonly used synonym for ecological accounting, though this term is distinct and does not cover many of the ecological challenges. Under this research area, there have more recently been attempts to bridge the difficult macro (planetary) and micro (organization) environmental challenge. Concepts such as Accounting for the Management of Ecosystems and Material Flow Cost Accounting are areas of research seen as offering future opportunities to develop into a more ecological management accounting framework, though this will ultimately require research in ecological management accounting based on a multi-disciplinary approach.
The Impact of Covid-19 Outbreak on the Tourism Needs of the Algerian Population
Authors: Madani Azzeddine , Boutebal Saad Eddine , Benhamida Hinde , Bryant Christopher Robin
Published: October 2020

This research aims to understand the vision and the reaction of the population towards tourism and holidays during this period of the COVID-19 pandemic. It also investigates the tourist needs of the Algerian population after the closure of international borders. Methods: The data were collected using a mixture of quantitative and qualitative methods through a questionnaire applied to 203 people in different regions of Algeria (a North African country) from 1 June to 13 July 2020. Results: The needs of Algerian tourists were characterized by a great need for leisure to relieve psychological stress caused by COVID-19 (M = 25.33) among the study sample (p < 0.05). The results also show an average need to rationalize the costs of tourist services (M = 5.26) according to the respondents (p < 0.01). This is in addition to the great need (M = 7.75) among respondents (p < 0.05) of the awareness that the tourism sector can contribute to the economic recovery in Algeria after the confinement period. About 75.86% of respondents requested the cleanliness of tourist sites, while 69.95% recommended improving safety because of the size of tourist sites in the Algerian territory as well as measures related to social distancing. The results show that 53.69% of respondents preferred the month of August to go on vacation, 29.06% chose the month of September, and 17.25% would prefer the months of October, November, and December since they expected a reduction in the risks of the COVID-19 pandemic. Conclusions: The COVID-19 pandemic has affected the tourism needs of the Algerian population, which has become increasingly aware of the consequences of the pandemic in relation to their health and in relation to the country’s economy. These results can help the authorities of the tourism sector to better understand and identify the tourism needs of this population in the current period and after the COVID-19 pandemic.
Accurate Physical Activity Recognition using Multidimensional Features and Markov Model for Smart Health Fitness
Authors: Nadeem Amir , Jalal Ahmad , Kim Kibum
Published: October 2020

Recent developments in sensor technologies enable physical activity recognition (PAR) as an essential tool for smart health monitoring and for fitness exercises. For efficient PAR, model representation and training are significant factors contributing to the ultimate success of recognition systems because model representation and accurate detection of body parts and physical activities cannot be distinguished if the system is not well trained. This paper provides a unified framework that explores multidimensional features with the help of a fusion of body part models and quadratic discriminant analysis which uses these features for markerless human pose estimation. Multilevel features are extracted as displacement parameters to work as spatiotemporal properties. These properties represent the respective positions of the body parts with respect to time. Finally, these features are processed by a maximum entropy Markov model as a recognition engine based on transition and emission probability values. Experimental results demonstrate that the proposed model produces more accurate results compared to the state-of-the-art methods for both body part detection and for physical activity recognition. The accuracy of the proposed method for body part detection is 90.91% on a University of Central Florida’s (UCF) sports action dataset and, for activity recognition on a UCF YouTube action dataset and an IM-DailyRGBEvents dataset, accuracy is 89.09% and 88.26% respectively.
Molecular Interactions between Asphaltene and Surfactants in a Hydrocarbon Solvent: Application to Asphaltene Dispersion
Authors: Ahmadi Mohammadali , Chen Zhangxin
Published: October 2020

Heavy oil and bitumen supply the vast majority of energy resources in Canada. Different methods can be implemented to produce oil from such unconventional resources. Surfactants are employed as an additive to water/steam to improve an injected fluid’s effectiveness and enhance oil recovery. One of the main fractions in bitumen is asphaltene, which is a non-symmetrical molecule. Studies of interactions between surfactants, anionic, and non-anionic, and asphaltene have been very limited in the literature. In this paper, we employed molecular dynamics (MD) simulation to theoretically focus on the interactions between surfactant molecules and different types of asphaltene molecules observed in real oil sands. Both non-anionic and anionic surfactants showed promising results in terms of dispersant efficiency; however, their performance depends on the asphaltene architecture. Moreover, a hydrogen/carbon (H/C) ratio of asphaltenes plays an inevitable role in asphaltene aggregation behavior. A higher H/C ratio resulted in decreasing asphaltene aggregation tendency. The results of these studies will give a deep understanding of the interactions between asphaltene and surfactant molecules.
Identification Elements Symmetry in Teaching Informatics in Czech Secondary School during the Covid-19 Outbreak from the Perspective of Students
Authors: Nemec R. , Jahodova Berkova A. , Hubalovsky S.
Published: October 2020

This article describes the research results aimed at distance education during the Covid-19 pandemic and closing schools and its symmetry with the classical state in terms of time, difficulty, and the mental and physical condition of students. An important aspect is therefore to maintain the symmetry of attitudes to teaching in face-to-face form and distance form. In terms of the eight-year gymnasium in the Czech Republic, students’ attitudes to the teaching subject informatics were investigated. The main research questions in our study dealt with whether students felt equally balanced regarding the amount of tasks and time taken for home preparation during the Covid-19 outbreak compared with the time before the quarantine and their condition (both mental and physical) during the Covid-19 outbreak. The research was conducted using an anonymous questionnaire, which was answered by 110 out of 180 students. According to the results, it is evident that students felt that during the distance education, there are more tasks compared to face-to-face ones. Students also claimed to spend more time learning at distance education than at school. On the other hand, they agreed that the self-education schedule is suitable for them. In terms of the questionnaire, their condition (both mental and physical) was also evaluated, which was slightly above the average.
Hesitant Fuzzy Sets Based Symmetrical Model of Decision-Making for Estimating the Durability of Web Application
Authors: Sahu Kavita , Alzahrani Fahad A. , Srivastava R. K. , Kumar Rajeev
Published: October 2020

The development of web applications essentially relies on users’ demands who expect highly efficacious but cost effective software services. Managing time and cost so as to develop web applications that cater to the users’ need is a challenge for developers at present. Moreover, low-cost maintenance can only be achieved by enhancing the durability of the web applications. Identifying characteristics of durability is a complex task because the different experts have different opinions regarding the significance of characteristics that determine durability quotient of the web applications. As established by the best practices undertaken in this context, some experts consider quality to be the most important factor for determining durability. Therefore, the present study enlists multi-criteria decision-based symmetrical technique to address the multi-vector option availability for the apt selection of the characteristics for durability. Furthermore, it has also been identified that a numerical assessment of web applications’ durability can affect the service life and low-cost management in web applications. In this context, to achieve high durability and longevity in web applications, this paper attempts to illustrate and perform a numerical evaluation of durability characteristics. By understanding the various characteristics and their significance towards durability, the paper finds that the hesitant fuzzy-based symmetrical technique of the Analytic Hierarchy Process (AHP) and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) is an effective methodology for evaluating web applications’ durability. For evaluating the quality of the results and establishing their sensitivity, the authors have assessed the outcomes on six different projects of the University. Additionally, results assessed and discussed in this paper would be a conclusive reference for the developers in their attempts to develop highly durable and manageable web applications.
Connections between Older Greek Adults’ Implicit Attributes and Their Perceptions of Online Technologies
Authors: Alexandrakis Diogenis , Chorianopoulos Konstantinos , Tselios Nikolaos
Published: October 2020

Older Greek adults make use of web technologies much less than the majority of their peers in Europe. Based on the fact that psychosocial attributes can also affect technology usage, this exploratory quantitative research is an attempt to focus on the implicit factors related to older Greek adults’ perceived usability, learnability, and ease-of-use of web technologies. For this aim, a web 2.0 storytelling prototype has been demonstrated to 112 participants and an online questionnaire was applied for data collection. According to the results, distinct correlations emerged between older adults’ characteristics (chronological age, loneliness, future time perspective) and the perceived usability, learnability, and ease-of-use of the presented prototype. These outcomes contribute to the limited literature in the field by probing the connections between older people’s implicit attributes and their evaluative perceptions of online technologies.
Using Multivariate Outliers from Smartphone Sensor Data to Detect Physical Barriers While Walking in Urban Areas
Authors: Ruiz Blázquez Ramona , Muñoz-Organero Mario
Published: October 2020

Nowadays, our mobile devices have become smart computing platforms, incorporating a wide number of embedded sensors such as accelerometers, gyroscopes, barometers, GPS receivers, and magnetometers. Smartphones are valuable devices for gathering user-related data and transforming it into value-added information for the user. In this study, a novel mechanism to process sensor data from mobile devices in order to detect the type of area the user is crossing while walking in an urban setting is presented. The method is based on combining outlier data analysis and classification techniques from data collected by several pedestrians while traversing an urban environment. A theoretical framework, composed of methods for detecting multivariate outliers combined with supervised classification techniques, has been proposed in order to identify different situations and physical barriers while walking. Each type of element to be detected is characterized by using a feature vector computed based on the outliers detected. Finally, a radial SVM is used for the classification task. The classifier is trained in a supervised way with data from 20 different segments containing several physical barriers and used later to assign a class to new un-labelled data. The results obtained with this approach are very promising with an average accuracy around 95% when detecting different types of physical barriers.
Nicotine Causes Nephrotoxicity through the Induction of NLRP6 Inflammasome and Alpha7 Nicotinic Acetylcholine Receptor
Authors: Zheng Cai-Mei , Lee Yu-Hsuan , Chiu I-Jen , Chiu Yu-Jhe , Sung Li-Chin , Hsu Yung-Ho , Chiu Hui-Wen
Published: October 2020

Current cigarette smoking is associated with chronic kidney disease (CKD) or death from end-stage renal disease (ESRD). Mainstream cigarette smoke includes over 4000 compounds. Among the compounds present in tobacco smoke, nicotine is one of a large number of biologically stable and active compounds present in tobacco. However, the mechanisms by which nicotine exacerbates kidney disease progression have not been identified. It is known that the inflammasomes constitute an important innate immune pathway and contribute to the pathophysiology of diverse kidney diseases. The relationship between inflammasomes and nicotine-induced kidney damage still remains unclear. In the present study, we studied the mechanisms of nicotine-induced nephrotoxicity. We found that nicotine decreased cell viability and induced reactive oxygen species (ROS) generation in human kidney cells. Furthermore, nicotine significantly increased the expression of the alpha7 nicotinic acetylcholine receptor (α7nAChR). Nicotine activated the NLRP6 inflammasome and induced endoplasmic reticulum (ER) stress. Nicotine caused mild apoptosis and necrosis but triggered significant autophagy in human kidney cells. In addition, nicotine induced the NLRP6 inflammasome and autophagy via α7nAChR. In an animal model, the histological analysis in kidney showed evident changes and injury. The results indicated that α7nAChR, IRE1α, LC3 and NLRP6 expression in kidney sections was markedly increased in the nicotine groups. These findings suggest that nicotine causes kidney damage by modulating α7nAChR, NLRP6 inflammasome, ER stress and autophagy.
Deterministic Assessment of the Risk of Phthalate Esters in Sediments of U-Tapao Canal, Southern Thailand
Authors: Kingsley Okpara , Witthayawirasak Banchong
Published: October 2020

This baseline study evaluated the ecological risk associated with the concentration of six common Phthalate esters (PAEs) in sediment samples collected from the U-Tapao canal in Southern Thailand. Deterministic approaches consisting of standard sediment quality guidelines (SQGs) and Risk quotient (RQ) were used to evaluate the potential ecological risk of individuals and a mixture of Phthalate esters (PAEs) detected in sediment samples. Of the 6 PAEs measured, only three, including di-n-butyl phthalate (DBP), di-2-ethyl hexyl phthalate (DEHP) and di-isononyl phthalate (DiNP), were identified and quantified. The total concentration of the 3 PAEs congeners found in the sediment samples ranged from 190 to 2010 ng/g dw. The results from the SQGs and RQ were not consistent with each other. The SQGs results for individual PAEs showed that DEHP and DBP found in sediment was estimated to cause moderate risk on benthic organisms, DiNP was not estimated due to lack of SQGs data. However, the RQ method indicated a low risk of DEHP and DBP on algae, crustacean and fish, whereas DiNP poses no risk on crustacean. Furthermore, based on the result obtained in this study, the consensus SQGs for mixture effects prove to be a more protective tool than the RQ concentration addition approach in predicting mixture effects. Despite inevitable uncertainties, the integration of several screening approaches of ecological risk assessment (ERA) can help get a more inclusive and credible result of the first tier of individuals and a mixture of these pollutants.
Qualitative Analysis of the Dynamics of a Two-Component Chiral Cosmological Model
Authors: Zhuravlev Viktor , Chervon Sergey
Published: October 2020

We present a qualitative analysis of chiral cosmological model (CCM) dynamics with two scalar fields in the spatially flat Friedman–Robertson–Walker Universe. The asymptotic behavior of chiral models is investigated based on the characteristics of the critical points of the selfinteraction potential and zeros of the metric components of the chiral space. The classification of critical points of CCMs is proposed. The role of zeros of the metric components of the chiral space in the asymptotic dynamics is analysed. It is shown that such zeros lead to new critical points of the corresponding dynamical systems. Examples of models with different types of zeros of metric components are represented.
New Physics of Strong Interaction and Dark Universe
Authors: Beylin Vitaly , Khlopov Maxim , Kuksa Vladimir , Volchanskiy Nikolay
Published: October 2020

The history of dark universe physics can be traced from processes in the very early universe to the modern dominance of dark matter and energy. Here, we review the possible nontrivial role of strong interactions in cosmological effects of new physics. In the case of ordinary QCD interaction, the existence of new stable colored particles such as new stable quarks leads to new exotic forms of matter, some of which can be candidates for dark matter. New QCD-like strong interactions lead to new stable composite candidates bound by QCD-like confinement. We put special emphasis on the effects of interaction between new stable hadrons and ordinary matter, formation of anomalous forms of cosmic rays and exotic forms of matter, like stable fractionally charged particles. The possible correlation of these effects with high energy neutrino and cosmic ray signatures opens the way to study new physics of strong interactions by its indirect multi-messenger astrophysical probes.
Thin-Shell Wormholes in Einstein and Einstein–Gauss–Bonnet Theories of Gravity
Authors: Kokubu Takafumi , Harada Tomohiro
Published: October 2020

We review recent works on the possibility for eternal existence of thin-shell wormholes on Einstein and Einstein–Gauss–Bonnet gravity. We introduce thin-shell wormholes that are categorized into a class of traversable wormhole solutions. After that, we discuss stable thin-shell wormholes with negative-tension branes in Reissner–Nordström–(anti) de Sitter spacetimes in d-dimensional Einstein gravity. Imposing Z2 symmetry, we construct and classify traversable static thin-shell wormholes in spherical, planar and hyperbolic symmetries. It is found that the spherical wormholes are stable against spherically symmetric perturbations. It is also found that some classes of wormholes in planar and hyperbolic symmetries with a negative cosmological constant are stable against perturbations preserving symmetries. In most cases, stable wormholes are found with the appropriate combination of an electric charge and a negative cosmological constant. However, as special cases, there are stable wormholes even with a vanishing cosmological constant in spherical symmetry and with a vanishing electric charge in hyperbolic symmetry. Subsequently, the existence and dynamical stability of traversable thin-shell wormholes with electrically neutral negative-tension branes is discussed in Einstein–Gauss–Bonnet theory of gravitation. We consider radial perturbations against the shell for the solutions, which have the Z2 symmetry. The effect of the Gauss–Bonnet term on the stability depends on the spacetime symmetry.