bluuebunny/crossref_metadata_2025 huggingface dataset:
Acceleration Compensation for Estimation of Along-Track Velocity of Ground Moving Target from Single-Channel SAR SLC Data
Authors: Kim Sang-Wan , Won Joong-Sun
Published: May 2020

Across-track acceleration is a major source of estimation error of along-track velocity in synthetic-aperture radar (SAR) ground moving-target indication (GMTI). This paper presents the theory and a method of compensating across-track acceleration to improve the accuracy of along-track velocity estimated from single-channel SAR single-look complex data. A unique feature of the proposed method is the utilisation of phase derivatives in the Doppler frequency domain, which is effective for azimuth-compressed signals. The performance of the method was evaluated through experimental data acquired by TerraSAR-X and speed-controlled and measured vehicles. The application results demonstrate a notable improvement in along-track velocity estimates. The amount of along-track velocity correction is particularly significant when a target has irregular motion with a low signal-to-clutter ratio. A discontinuous velocity jump rather than a constant acceleration was also observed and verified through comparison between actual data and simulations. By applying this method, the capability of single-channel SAR GMTI could be substantially improved in terms of accuracy of velocity, and moving direction. However, the method is effective only if the correlation between the actual Doppler phase derivatives and a model derived from the residual Doppler rate is sufficiently high. The proposed method will be applied to X-band SAR systems of KOMPSAT-5 and -6.
Performance of an Unmanned Aerial Vehicle (UAV) in Calculating the Flood Peak Discharge of Ephemeral Rivers Combined with the Incipient Motion of Moving Stones in Arid Ungauged Regions
Authors: Yang Shengtian , Li Chaojun , Lou Hezhen , Wang Pengfei , Wang Juan , Ren Xiaoyu
Published: May 2020

Ephemeral rivers are vital to ecosystem balance and human activities as essential surface runoff, while convenient and effective ways of calculating the peak discharge of ephemeral rivers are scarce, especially in ungauged areas. In this study, a new method was proposed using an unmanned aerial vehicle (UAV) combined with the incipient motion of stones to calculate the peak discharge of ephemeral rivers in northwestern China, a typical arid ungauged region. Two field surveys were conducted in dry seasons of 2017 and 2018. Both the logarithmic and the exponential velocity distribution methods were examined when estimating critical initial velocities of moving stones. Results reveal that centimeter-level orthoimages derived from UAV data can demonstrate the movement of stones in the ephemeral river channel throughout one year. Validations with peak discharge through downstream culverts confirmed the effectiveness of the method. The exponential velocity distribution method performs better than the logarithmic method regardless of the amount of water through the two channels. The proposed method performs best in the combination of the exponential method and the river channel with evident flooding (>20 m3/s), with the relative accuracy within 10%. In contrast, in the river channel with a little flow (around 1 m3/s), the accuracies are weak because of the limited number of small moving stones found due to the current resolution of UAV data. The poor performance in the river channel with a little flow could further be improved by identifying smaller moving stones, especially using UAV data with better spatial resolution. The presented method is easy and flexible to apply with appropriate accuracy. It also has great potential for extensive applications in obtaining runoff information of ephemeral rivers in ungauged regions, especially with the quick advance of UAV technology.
Mapping Annual Land Disturbance and Reclamation in a Surface Coal Mining Region Using Google Earth Engine and the LandTrendr Algorithm: A Case Study of the Shengli Coalfield in Inner Mongolia, China
Authors: Xiao Wu , Deng Xinyu , He Tingting , Chen Wenqi
Published: May 2020

The development and utilization of mining resources are basic requirements for social and economic development. Both open-pit mining and underground mining have impacts on land, ecology, and the environment. Of these, open-pit mining is considered to have the greatest impact due to the drastic changes wrought on the original landform and the disturbance to vegetation. As awareness of environmental protection has grown, land reclamation has been included in the mining process. In this study, we used the Shengli Coalfield in the eastern steppe region of Inner Mongolia to demonstrate a mining and reclamation monitoring process. We combined the Google Earth Engine platform with time series Landsat images and the LandTrendr algorithm to identify and monitor mining disturbances to grassland and land reclamation in open-pit mining areas of the coalfield between 2003 and 2019. Pixel-based trajectories were used to reconstruct the temporal evolution of vegetation, and sequential Landsat archive data were used to achieve accurate measures of disturbances to vegetation. The results show that: (1) the proposed method can be used to determine the years in which vegetation disturbance and recovery occurred with accuracies of 86.53% and 78.57%, respectively; (2) mining in the Shengli mining area resulted in the conversion of 89.98 km2 of land from grassland, water, etc., to barren earth, and only 23.54 km2 was reclaimed, for a reclamation rate of 26.16%; and (3) the method proposed in this paper can achieve fast, efficient identification of surface mining land disturbances and reclamation, and has the potential to be applied to other similar areas.
Employment of 1-Methoxy-5-Ethyl Phenazinium Ethyl Sulfate as a Stable Electron Mediator in Flavin Oxidoreductases-Based Sensors
Authors: Fitriana Maya , Loew Noya , Witarto Arief Budi , Ikebukuro Kazunori , Sode Koji , Tsugawa Wakako
Published: May 2020

In this paper, a novel electron mediator, 1-methoxy-5-ethyl phenazinium ethyl sulfate (mPES), was introduced as a versatile mediator for disposable enzyme sensor strips, employing representative flavin oxidoreductases, lactate oxidase (LOx), glucose dehydrogenase (GDH), and fructosyl peptide oxidase (FPOx). A disposable lactate enzyme sensor with oxygen insensitive Aerococcus viridans-derived engineered LOx (AvLOx), with A96L mutant as the enzyme, was constructed. The constructed lactate sensor exhibited a high sensitivity (0.73 ± 0.12 μA/mM) and wide linear range (0–50 mM lactate), showings that mPES functions as an effective mediator for AvLOx. Employing mPES as mediator allowed this amperometric lactate sensor to be operated at a relatively low potential of +0.2 V to 0 V vs. Ag/AgCl, thus avoiding interference from uric acid and acetaminophen. The lactate sensors were adequately stable for at least 48 days of storage at 25 °C. These results indicated that mPES can be replaced with 1-methoxy-5-methyl phenazinium methyl sulfate (mPMS), which we previously reported as the best mediator for AvLOx-based lactate sensors. Furthermore, this study revealed that mPES can be used as an effective electron mediator for the enzyme sensors employing representative flavin oxidoreductases, GDH-based glucose sensors, and FPOx-based hemoglobin A1c (HbA1c) sensors.
A Fuzzy Analytic Hierarchy Process and Cooperative Game Theory Combined Multiple Mobile Robot Navigation Algorithm
Authors: Kim Changwon , Won Jong-Seob
Published: May 2020

This study presents a multi-robot navigation strategy based on a multi-objective decision-making algorithm, the Fuzzy Analytic Hierarchy Process (FAHP). FAHP analytically selects an optimal position as a sub-goal among points on the sensing boundary of a mobile robot considering the following three objectives: the travel distance to the target, collision safety with obstacles, and the rotation of the robot to face the target. Alternative solutions are evaluated by quantifying the relative importance of the objectives. As the FAHP algorithm is insufficient for multi-robot navigation, cooperative game theory is added to improve it. The performance of the proposed multi-robot navigation algorithm is tested with up to 12 mobile robots in several simulation conditions, altering factors such as the number of operating robots and the warehouse layout.
Real-Time Energy Efficient Hand Pose Estimation: A Case Study
Authors: Al Koutayni Mhd Rashed , Rybalkin Vladimir , Malik Jameel , Elhayek Ahmed , Weis Christian , Reis Gerd , Wehn Norbert , Stricker Didier
Published: May 2020

The estimation of human hand pose has become the basis for many vital applications where the user depends mainly on the hand pose as a system input. Virtual reality (VR) headset, shadow dexterous hand and in-air signature verification are a few examples of applications that require to track the hand movements in real-time. The state-of-the-art 3D hand pose estimation methods are based on the Convolutional Neural Network (CNN). These methods are implemented on Graphics Processing Units (GPUs) mainly due to their extensive computational requirements. However, GPUs are not suitable for the practical application scenarios, where the low power consumption is crucial. Furthermore, the difficulty of embedding a bulky GPU into a small device prevents the portability of such applications on mobile devices. The goal of this work is to provide an energy efficient solution for an existing depth camera based hand pose estimation algorithm. First, we compress the deep neural network model by applying the dynamic quantization techniques on different layers to achieve maximum compression without compromising accuracy. Afterwards, we design a custom hardware architecture. For our device we selected the FPGA as a target platform because FPGAs provide high energy efficiency and can be integrated in portable devices. Our solution implemented on Xilinx UltraScale+ MPSoC FPGA is 4.2× faster and 577.3× more energy efficient than the original implementation of the hand pose estimation algorithm on NVIDIA GeForce GTX 1070.
Field Test of Excess Pore Water Pressure at Pile–Soil Interface Caused by PHC Pipe Pile Penetration Based on Silicon Piezoresistive Sensor
Authors: Wang Yonghong , Liu Xueying , Zhang Mingyi , Yang Suchun , Sang Songkui
Published: May 2020

Prestressed high-strength concrete (PHC) pipe pile with the static press-in method has been widely used in recent years. The generation and dissipation of excess pore water pressure at the pile–soil interface during pile jacking have an important influence on the pile’s mechanical characteristics and bearing capacity. In addition, this can cause uncontrolled concrete damage. Monitoring the change in excess pore water pressure at the pile–soil interface during pile jacking is a plan that many researchers hope to implement. In this paper, field tests of two full-footjacked piles were carried out in a viscous soil foundation, the laws of generation and dissipation of excess pore water pressure at the pile–soil interface during pile jacking were monitored in real time, and the laws of variation in excess pore water pressure at the pile–soil interface with the burial depth and time were analyzed. As can be seen from the test results, the excess pore water pressure at the pile–soil interface increased to the peak and then began to decline, but the excess pore water pressure after the decline was still relatively large. Test pile S1 decreased from 201.4 to 86.3 kPa, while test pile S2 decreased from 374.1 to 114.3 kPa after pile jacking. The excess pore water pressure at the pile–soil interface rose first at the initial stage of consolidation and dissipated only after the hydraulic gradient between the pile–soil interface and the soil surrounding the pile disappeared. The dissipation degree of excess pore water pressure reached about 75–85%. The excess pore water pressure at the pile–soil interface increased with the increase in buried depth and finally tended to stabilize.
Reflections and Methodological Proposals to Treat the Concept of “Information Precision” in Smart Agriculture Practices
Authors: Mazzetto Fabrizio , Gallo Raimondo , Sacco Pasqualina
Published: May 2020

Smart Agriculture (SA) is an evolution of Precision Farming (PF). It has technological basis very close to the paradigms of Industry 4.0 (Ind-4.0), so that it is also often referred to as Agriculture 4.0. After the proposal of a brief historical examination that provides a conceptual frame to the above terms, the common aspects of SA and Ind-4.0 are analyzed. These are primarily to be found in the cognitive approaches of Knowledge Management 4.0 (KM4.0, the actual theoretical basis of Ind-4.0), which underlines the need to use Integrated Information Systems (IIS) to manage all the activity areas of any production system. Based upon an infological approach, “raw data” becomes “information” only when useful to (or actually used in) a decision-making process. Thus, an IIS must be always designed according to such a view, and KM4.0 conditions the way of collecting and processing data on farms, together with the “information precision” by which the production system is managed. Such precision needs, on their turn, depend on the hierarchical level and the “Macrodomain of Prevailing Interest” (MPI) related to each decision, where the latter identifies a predominant viewpoint through which a system can be analyzed according to a prevailing purpose. Four main MPIs are here proposed: (1) physical and chemical, (2) biological and ecological, (3) productive and hierarchical, and (4) economic and social. In each MPI, the quality of the knowledge depends on the cognitive level and the maturity of the methodological approaches there achieved. The reliability of information tends to decrease from the first to the fourth MPI; lower the reliability, larger the tolerance margins that a measurement systems must ensure. Some practical examples are then discussed, taking into account some IIS-monitoring solutions of increasing complexity in relation to information integration needs and related data fusion approaches. The analysis concludes with the proposal of new operational indications for the verification and certification of the reliability of the information on the entire decision-making chain.
Polarization Beam Splitter Based on Si3N4/SiO2 Horizontal Slot Waveguides for On-Chip High-Power Applications
Authors: Fang Yuxi , Bao Changjing , Wang Zhonghan , Liu Yange , Zhang Lin , Huang Hao , Ren Yongxiong , Pan Zhongqi , Yue Yang
Published: May 2020

In this paper, we propose an Si3N4/SiO2 horizontal-slot-waveguide-based polarization beam splitter (PBS) with low nonlinearity for on-chip high-power systems. The coupling length ratio between the quasi-TE and quasi-TM modes (LTE/LTM) was optimized to 2 for an efficient polarization splitting. For the single-slot design, the coupling length of the PBS was 281.5 μm, while the extinction ratios (ER) of the quasi-TM and quasi-TE modes were 23.9 dB and 20.8 dB, respectively. Compared to PBS based on the Si3N4 strip waveguide, the coupling length became 22.6% shorter. The proposed PBSs also had a relatively good fabrication tolerance for an ER of >20 dB. For the multi-slot design, the coupling length of the PBS was 290.3 μm, while the corresponding ER of the two polarizations were 24.0 dB and 21.0 dB, respectively. Furthermore, we investigated the tradeoff between the ER and coupling length for the optimized PBSs with single slot or multiple slots.
Graphene Electro-Optical Switch Modulator by Adjusting Propagation Length Based on Hybrid Plasmonic Waveguide in Infrared Band
Authors: Cai Ming , Wang Shulong , Liu Zhihong , Wang Yindi , Han Tao , Liu Hongxia
Published: May 2020

A modulator is the core of many optoelectronic applications such as communication and sensing. However, a traditional modulator can hardly reach high modulation depth. In order to achieve the higher modulation depth, a graphene electro-optical switch modulator is proposed by adjusting propagation length in the near infrared band. The switch modulator is designed based on a hybrid plasmonic waveguide structure, which is comprised of an SiO2 substrate, graphene–Si–graphene heterostructure, Ag nanowire and SiO2 cladding. The propagation length of the hybrid plasmonic waveguide varies from 0.14 μm to 20.43 μm by the voltage tunability of graphene in 1550 nm incident light. A modulator with a length of 3 μm is designed based on the hybrid waveguide and it achieves about 100% modulation depth. The lower energy loss (~1.71 fJ/bit) and larger 3 dB bandwidth (~83.91 GHz) are attractive for its application in a photoelectric integration field. In addition, the excellent robustness (error of modulation effects lower than 8.84%) is practical in the fabrication process. Most importantly, by using the method of adjusting propagation length, other types of graphene modulators can also achieve about 100% modulation depth.
Portable XRF Quick-Scan Mapping for Potential Toxic Elements Pollutants in Sustainable urban Drainage Systems: A Methodological Approach
Authors: Venvik Guri , Boogaard Floris C.
Published: May 2020

Sustainable urban drainage systems (SuDS) such as swales are designed to collect, store and infiltrate a large amount of surface runoff water during heavy rainfall. Stormwater is known to transport pollutants, such as particle-bound Potential Toxic Elements (PTE), which are known to often accumulate in the topsoil. A portable XRF instrument (pXRF) is used to provide in situ spatial characterization of soil pollutants, specifically lead (Pb), zink (Zn) and copper (Cu). The method uses pXRF measurements of PTE along profiles with set intervals (1 m) to cover the swale with cross-sections, across the inlet, the deepest point and the outlet. Soil samples are collected, and the In-Situ measurements are verified by the results from laboratory analyses. Stormwater is here shown to be the transporting media for the pollutants, so it is of importance to investigate areas most prone to flooding and infiltration. This quick scan method is time and cost-efficient, easy to execute and the results are comparable to any known (inter)national threshold criteria for polluted soils. The results are of great importance for all stakeholders in cities that are involved in climate adaptation and implementing green infrastructure in urban areas. However, too little is still known about the long-term functioning of the soil-based SuDS facilities.
An Economic Order Quantity Stochastic Dynamic Optimization Model in a Logistic 4.0 Environment
Authors: Di Nardo Mario , Clericuzio Mariano , Murino Teresa , Sepe Chiara
Published: May 2020

This paper proposes a stock dynamic sizing optimization under the Logistic 4.0 environment. The safety stock is conceived to fill up the demand variability, providing continuous stock availability. Logistic 4.0 and the smart factory topics are considered. It focuses on vertical integration to implement flexible and reconfigurable smart production systems using the information system integration in order to optimize material flow in a 4.0 full-service approach. The proposed methodology aims to reduce the occurring stock-out events through a link among the wear-out items rate and the downstream logistic demand. The failure rate items trend is obtained through life-cycle state detection by a curve fitting technique. Therefore, the optimal safety stock size is calculated and then validated by an auto-tuning iterative modified algorithm. In this study, the reorder time has been optimized. The case study refers to the material management of a very high-speed train.
The Relationship between Innovation and Sustainability: A Bibliometric Review of the Literature
Authors: Maier Dorin , Maier Andreea , Așchilean Ioan , Anastasiu Livia , Gavriș Ovidiu
Published: May 2020

The research conducted in this paper is directed towards a bibliometric review and a visualization analysis of the relationship between innovation and sustainability. The main objective is to empirically document the intellectual structure, the volume and the knowledge-development directions. For this objective, we used the VOS Viewer software and the scientific databases ISI Web of Science (WoS). We identify that there is a big increase in volume of articles on innovation and sustainability published in the last 10 years, from 2010 up to 2019, compared to the entire period before 2010. Given the large amount of the literature, we form an ample database of 436 peer-reviewed articles published in the last 10 years. The bibliometric analysis reveals the most influential journals, authors and papers in the studied field. This research reveals that by combining the main aspects of innovation and sustainability in a single concept like “sustainable innovation”, an emerging topic can appear, and it can offer new research directions in the very big field of innovation and in the new and actual field of sustainability.
Development of a Global SDG Progress Index Aimed at “Leaving No One Behind”
Authors: Puertas Jerónimo , Bermúdez María
Published: May 2020

The United Nation’s Sustainable Development Goals (SDGs) constitute a set of shared global objectives for the development over the coming years, which both developed and developing countries are working together to achieve. It is, however, very difficult to know from tracking national-level SDG performance estimates whether steps are being taken to arrive at 2030 with an adequate degree of compliance, and fully delivering on the aim of “leaving no one behind”. This paper proposes and evaluates a Global SDG Progress Index which exploits the reported country rankings for the SDG Index, and incorporates a series of weighting coefficients to effectively involve all countries in improving SDG performance, regardless of their position in the ranking. Thresholds for the index are established to determine the adequacy of progress in relation to the 2030 goals. The results show that the current rate of progress in developing countries (assuming as an indicator GDP per capita values) is insufficient to achieve equitable compliance with the SDGs at the global level.
Advancing Applied Research in High Volume Transport in Low-Income Countries in Africa and South Asia
Authors: Thompson Bruce , Obika Bernard
Published: May 2020

The Department for International Development (DFID) is funding the High Volume Transport (HVT) Applied Research Programme. This programme is an integral component of the UK response to delivering transport and mobility that is accessible, efficient, safe, and green in the low-income countries (LICs) in Africa and South Asia. The first part of the HVT programme produced an up-to-date and comprehensive state of knowledge on high volume transport in these countries. This Special Issue presents a selection of papers to cover key research priorities identified in road and rail transport, low carbon transport, and gender and inclusive transport. The state of knowledge has produced a sound basis for setting priorities for applied research in the second part of the programme. Applied research is directed to delivering high volume transport that contributes to economic growth and social development, and that is more resilient to the impact of climate change in LICs in Africa and South Asia.
A Sustainable Approach: Increasing Students’ Information-Technology Competences and Job-Seeking Capabilities through Course Redesign Using FIT Framework and Active Learning Pedagogy
Authors: Pan Tung-Ming , Fan Kuo-Chin
Published: May 2020

FIT, Fluency with Information Technology, was developed by the National Research Council, USA in 1999. A FIT individual is defined as someone who can build new knowledge based on his/her prior knowledge, be self-sustaining when changes happen, and find solutions creatively to solve more complicated problems. Using FIT framework and active learning concept to restructure an information technology (IT) course is a sustainable approach to helping students learn, think, and adapt to the constant changes of technology. This article illustrates how FIT framework helped redesign a general education Network Resources and Applications course to enhance students’ IT competences and job-seeking capabilities. It describes (1) the importance of IT education in Taiwan to sustain its high-tech economy, (2) the trend of IT literacy education and active learning presented in literature, (3) how FIT intellectual framework was applied to redesign this course and how active learning strategies were incorporated into teaching, and (4) how pre-test, post-test, and Likert-Scale statistical methodology were used to measure the effectiveness of this new approach. Test results indicated that the new approach did effectively facilitate teaching and increase students’ learning performance, which is consistent with the findings presented in the literature.
Self-Reinforcing Processes Governing Urban Sprawl in Belgium: Evidence over Six Decades
Authors: Mustafa Ahmed , Teller Jacques
Published: May 2020

Urban sprawl is widely acknowledged as an environmental and socio-economic challenge worldwide. This study examines urban sprawl in Belgium over six decades from 1950 to 2010. We assume that sprawl is a self-reinforcing process, i.e., sprawl is fueling further sprawl over time. The main objective of this study is to examine this assumption. We measure urban sprawl at four different levels in this study: country, regions, municipalities, and 1-km2 cells. Three sprawl indices are employed: the degree of urban dispersion, degree of urban permeation of the landscape, and built-up land uptake per capita. These three indices consider both the growth of built-up areas and population density to measure the magnitude of sprawl. The drivers of urban sprawl have been analyzed at a 1-km2 level. The examined drivers are previous urban dispersion patterns, distance to urban cores, elevation, and slope degree by means of linear regression. Urban sprawl significantly increased between 1950 and 1980, whereas its increase was more moderate between 1980 and 2010. Urban dispersion and permeation strongly affect the Brussels and Flanders regions. The results show that the increase in the degree of dispersion is locally driven by previous values of dispersion; i.e., it provides an adequate milieu for further dispersion. Therefore, our conclusion is that urban sprawl in Belgium tends to be a self-reinforcing process.
Cooperatives and Sustainable Development: A Multilevel Approach Based on Intangible Assets
Authors: Castilla-Polo Francisca , Sánchez-Hernández M. Isabel
Published: May 2020

There is a major interest in analyzing the role of intangible assets on sustainable development, which is a topic under the auspices of the so-called 5th stage of research. Cooperatives are enterprises directly committed to sustainable development due to their dual nature–economic and social. This paper is based on a literature review and proposes a theoretical model based on intangible assets for understanding the role of cooperatives as drivers of sustainable development. The findings show that these assets are involved in regional competitiveness and especially evident when considering cooperatives. It can be concluded that, when focusing the attention on cooperatives, it is useful to use a multilevel approach (micro and macro levels) to understand the whole process of interaction between intangible assets and sustainable development. The model aims to contribute to a line of research of great potential, but is also a practical tool for reflecting on cooperativism and for government agencies.
A Context-Aware Location Recommendation System for Tourists Using Hierarchical LSTM Model
Authors: Shafqat Wafa , Byun Yung-Cheol
Published: May 2020

The significance of contextual data has been recognized by analysts and specialists in numerous disciplines such as customization, data recovery, ubiquitous and versatile processing, information mining, and management. While a generous research has just been performed in the zone of recommender frameworks, by far most of the existing approaches center on prescribing the most relevant items to customers. It usually neglects extra-contextual information, for example time, area, climate or the popularity of different locations. Therefore, we proposed a deep long-short term memory (LSTM) based context-enriched hierarchical model. This proposed model had two levels of hierarchy and each level comprised of a deep LSTM network. In each level, the task of the LSTM was different. At the first level, LSTM learned from user travel history and predicted the next location probabilities. A contextual learning unit was active between these two levels. This unit extracted maximum possible contexts related to a location, the user and its environment such as weather, climate and risks. This unit also estimated other effective parameters such as the popularity of a location. To avoid feature congestion, XGBoost was used to rank feature importance. The features with no importance were discarded. At the second level, another LSTM framework was used to learn these contextual features embedded with location probabilities and resulted into top ranked places. The performance of the proposed approach was elevated with an accuracy of 97.2%, followed by gated recurrent unit (GRU) (96.4%) and then Bidirectional LSTM (94.2%). We also performed experiments to find the optimal size of travel history for effective recommendations.
Sustainable Supply Chain in the Era of Industry 4.0 and Big Data: A Systematic Analysis of Literature and Research
Authors: Chalmeta Ricardo , Santos-deLeón Nestor J.
Published: May 2020

Supply chain sustainability (SCS) in the age of Industry 4.0 and Big Data is a growing area of research. However, there are no systematic and extensive studies that classify the different types of research and examine the general trends in this area of research. This paper reviews the literature on sustainability, Big Data, Industry 4.0 and supply chain management published since 2009 and provides a thorough insight into the field by using bibliometric and network analysis techniques. A total of 87 articles published in the past 10 years were evaluated and the top contributing authors, countries, and key research topics were identified. Furthermore, the most influential works based on citations and PageRank were obtained and compared. Finally, six research categories were proposed in which scholars could be encouraged to expand Big Data and Industry 4.0 research on SCS. This paper contributes to the literature on SCS in the age of Industry 4.0 by discussing the challenges facing current research but also, more importantly, by identifying and proposing these six research categories and future research directions.
Necessity of a Multifaceted Approach in Analyzing Growth of Impervious Surfaces
Authors: Abubakar Ghali Abdullahi , Wu Jiexia , Shahtahmassebi Amir Reza , Wang Ke
Published: May 2020

While substantial efforts have been devoted to the remote sensing of impervious surfaces, few studies have developed frameworks to connect impervious surfaces’ growth with spatial planning decisions. To this end, this paper develops a multifaceted approach with three components: Visualization, numerical analysis, and simulation at the sub-pixel level. First, the growth of impervious surfaces was visualized through write function memory (WFM) insertion for the period of 1974–2009 of Cixi County in Zhejiang Province, China. Second, anomaly detection, statistical analysis, and landscape metrics were used to quantify changes in impervious surfaces over time. Finally, a slope, land use, exclusion, urban extent, transportation, and hill shade (SLEUTH) cellular automata model was employed to simulate the impervious surface growth until 2015 under four specific spatial decision scenarios: Current trends, environmental protection growth, business growth, and Chinese policy for protecting rural regions. The results show that Cixi County experienced compact growth due to expansion and internal intensification. Interestingly, the SLEUTH reveals that the projected space of impervious surfaces’ growth was consistent with reality in 2015. The framework established in this study holds considerable potential for improving our understanding of the interaction between impervious surfaces’ growth and planning aspects.
Deforestation and Subsequent Cultivation of Nutrient Poor Soils of Miombo Woodlands of Tanzania: Long Term Effect on Maize Yield and Soil Nutrients
Authors: Rannestad Meley Mekonen , Gessesse Tigist Araya
Published: May 2020

The miombo woodlands of Tanzania have continued to be subjected to deforestation due to mainly agricultural expansion. Knowledge of long-term productivity of the subsequent land use can help to evaluate the sustainability of the existing land management systems. We used both socioeconomic and soil survey data to assess maize yield and selected soil properties, respectively, with an increasing cultivation period since conversion from miombo woodland. Data on maize production was collected from 121 households in three villages, while soil sampling was undertaken on 15 plots in one of the study villages. Soil samples were taken from miombo woodland and from croplands with cultivation periods varying from two to 52 years. Samples were taken at 0–10 cm and 10–20 cm depths and analyzed for the major plant nutrients. According to the results of the socioeconomic data analysis, continued cultivation of former miombo woodlands does not have a significant effect on maize yield. The results of the soil analysis also showed that the major plant nutrients on farmlands in both soil layers did not show a significant change from the adjacent miombo woodland and did not decline with increasing cultivation period. This indicates that the current farming system can maintain the levels of the major plant nutrients and thus soil productivity.
Multi-Period Planning of Hydrogen Supply Network for Refuelling Hydrogen Fuel Cell Vehicles in Urban Areas
Authors: Bae Sungmi , Lee Eunhan , Han Jinil
Published: May 2020

The hydrogen economy refers to an economic and industrial structure that uses hydrogen as its main energy source, replacing traditional fossil-fuel-based energy systems. In particular, the widespread adoption of hydrogen fuel cell vehicles (HFCVs) is one of the key factors enabling a hydrogen economy, and aggressive investment in hydrogen refuelling infrastructure is essential to make large-scale adoption of HFCVs possible. In this study, we address the problem of effectively designing a hydrogen supply network for refuelling HFCVs in urban areas relatively far from a large hydrogen production site, such as a petrochemical complex. In these urban areas where mass supply of hydrogen is not possible, hydrogen can be supplied by reforming city gas. In this case, building distributed hydrogen production bases that extract large amounts of hydrogen from liquefied petroleum gas (LPG) or compressed natural gas (CNG) and then supply hydrogen to nearby hydrogen stations may be a cost-effective option for establishing a hydrogen refuelling infrastructure in the early stage of the hydrogen economy. Therefore, an optimization model is proposed for effectively deciding when and where to build hydrogen production bases and hydrogen refuelling stations in an urban area. Then, a case study of the southeastern area of Seoul, known as a commercial and residential center, is discussed. A variety of scenarios for the design parameters of the hydrogen supply network are analyzed based on the target of the adoption of HFCVs in Seoul by 2030. The proposed optimization model can be effectively used for determining the time and sites for building hydrogen production bases and hydrogen refuelling stations.
From Bio to Nano: A Review of Sustainable Methods of Synthesis of Carbon Nanotubes
Authors: Janas Dawid
Published: May 2020

This review summarizes the up-to-date techniques devised to synthesize carbon nanotubes (CNTs) from liquid or solid precursors of sustainable nature. The possibility to replace petroleum-based feeds for renewable resources such as essential oils or plant shoots is critically examined. The analysis shows that the complex nature of such resources requires the optimization of the reaction conditions to obtain products of desired microstructure and chemical composition. However, appropriate tuning of the process parameters enables the synthesis of even high-purity single-walled CNTs with a spectrum of demonstrated high-performance applications at low cost. The sheer number of successful studies completed on this front so far and described herein validate that the development of techniques for the manufacture of such products of high-added value from common precursors is not only possible but, most importantly, promising.
Impacts of Climate Change on the Potential Productivity of Eleven Staple Crops in Rwanda
Authors: Austin Kemen , Beach Robert , Lapidus Daniel , Salem Marwa , Taylor Naomi , Knudsen Mads , Ujeneza Noel
Published: May 2020

This study quantifies the potential responses of 11 staple crop yields to projected changes in temperature and precipitation in Rwanda, using a cross sectional model based on yield data collected across more than 14,000 villages. We incorporated a relatively high spatial resolution dataset on crop productivity, considered a broad range of crops relevant to national agricultural production priorities, used environmental data developed specifically for Rwanda, and reported uncertainty both from our estimation model and due to uncertainty in future climate projections. We estimate that future climate change will have the largest impacts on potential productivity of maize, bush bean, and Irish potato. All three crops are likely to experience a reduction in potential yields of at least 10% under Representative Concentration Pathway (RCP) 4.5 and at least 15% under RCP 8.5 by 2050. Notably, these are important crops nationally, and three of the crops targeted by Rwanda’s Crop Intensification Program. We find that the most severe reductions in potential crop yields will occur in the drier eastern savannah and plateau regions, but that the impacts of climate change could be neutral or even positive in the highlands through mid-century. The refined spatial scale of our analysis allows us to identify potentially vulnerable regions where adaptation investments may need to be prioritized to support food security and climate resilience in Rwanda’s agricultural sector.
Users’ Perception of Value of Travel Time and Value of Ridesharing Impacts on Europeans’ Ridesharing Participation Intention: A Case Study Based on MoTiV European-Wide Mobility and Behavioral Pattern Dataset
Authors: Malichová Eva , Pourhashem Ghadir , Kováčiková Tatiana , Hudák Martin
Published: May 2020

Ridesharing as a form of mobility service increased significantly and has become a popular concept in recent years among users, mobility authorities, and transport service providers. This research focused on exploring an emerging view of value of travel time (VTT) from the traveler’s perspective, based on the stated travel time worthwhileness, preferences and motivations on their intention towards participation in ridesharing to evaluate individual’s perception of VTT and perceived value of ridesharing (VRS) impacts on intentions to participate in car sharing for their daily commuting using multinomial logit (MNL) model. This is particularly relevant today, as peer-to-peer mobility services are on the one hand shaping and redefining the value of technologies, and services, and on the other hand introducing new actors in the mobility eco-system. This study describes a survey of 278 people in 4 European countries: Finland, Portugal, Spain, and Slovakia as part of the “Mobility and Time Value” (MoTiV) H2020 project EU-wide data collection. In short, the empirical analysis indicates the high significance of enjoyment in terms of travel time worthwhileness on ridesharing adoption for commuting trips. Results also revealed economic benefit and enjoyment of being social as major motivators for participation in ridesharing. Findings are discussed in terms of implications for urban and transport planners, policy makers, and authorities to implement in shared mobility planning and to prepare transport policies which are tailored to individuals’ ridesharing needs and travel preferences and count also on travel happiness factors to better reflect the traveler’s personal ambitions. Suggestions for future research on shared mobility planning are outlined in conclusion.
Higher Levels of Physical Fitness Are Associated with Lower Peak Plantar Pressures in Older Women
Authors: Štefan Lovro , Kasović Mario , Zvonař Martin
Published: May 2020

Little is known about how physical fitness is associated with peak plantar pressures in older adults. Therefore, the main purpose of the study was to explore whether higher physical fitness levels were associated with lower peak plantar pressures in a sample of community-dwelling older adults. In this cross-sectional study, we recruited 120 older women aged ≥60 years. To assess the level of peak plantar pressure, we used a Zebris plantar pressure platform. To estimate the level of physical fitness, a senior fitness test battery was used. To calculate the associations between the level of physical fitness and peak plantar pressures beneath the different foot regions (forefoot, midfoot and hindfoot), we used generalized estimating equations with a linear regression model. In unadjusted models, higher physical fitness levels were associated with lower peak plantar pressures. When we adjusted for chronological age, the risk of falls and the presence of foot pain, higher physical fitness levels remained associated with lower peak plantar pressures. Our study shows that higher levels of physical fitness are associated with lower peak plantar pressures, even after adjusting for several potential covariates.
The Effects of Ambient Illumination, Color Combination, Sign Height, and Observation Angle on the Legibility of Wayfinding Signs in Metro Stations
Authors: Shi Yuqi , Zhang Yi , Wang Tao , Li Chaoyang , Yuan Shengqiang
Published: May 2020

Well-designed wayfinding signs play an important role in improving the service level of metro stations, ensuring the safety of passengers in evacuation, and promoting the sustainable development of public transport. This study explored the effects of ambient illumination, color combination, sign height, and observation angle on wayfinding signs’ legibility in metro stations. In the experiment, simulated metro-wayfinding signs were made to test legibility. As designed, the legibility was measured based on the following independent variables: two levels of ambient illumination (70 lux and 273 lux), two target/background color combinations (achromatic-white target on black background, chromatic-yellow target on black background), two sign heights (1.5 m and 2 m), and three observation angles (0°, 45°, 70°). The results showed that brighter ambient illumination provided passengers with higher legibility. Achromatic color combination was more legible than chromatic color combination, but not significantly. Different types of signs, set at different height, did not directly affect legibility. Observation angle had significant effects on legibility. Visibility catchment area of wayfinding signs was like an ellipse, with its short axis nearly equal to the legibility distance of the sign at 0 degrees. The findings will facilitate the layout and setting location of wayfinding signs in metro stations and improve the level of wayfinding service.
SU(2) × SU(2) Algebras and the Lorentz Group O(3,3)
Authors: Walker Martin
Published: May 2020

The Lie algebra of the Lorentz group O(3,3) admits two types of SU(2) × SU(2) subalgebras: a standard form based on spatial rotation generators and a second form based on temporal rotation generators. The units of measurement for the conserved quantity due to invariance under temporal rotations are investigated and found to be the same units of measure as the Planck constant. The breaking of time reversal symmetry is considered and found to affect the chiral properties of a temporal SU(2) × SU(2) algebra. Finally, the symmetry between algebras is explored and pairs of algebras are found to be related by SU(2) × U(1) symmetry, while a group of three algebras are related by SO(4) symmetry.
Neutrosophic Components Semigroups and Multiset Neutrosophic Components Semigroups
Authors: W. B. Vasantha , Kandasamy Ilanthenral , Smarandache Florentin
Published: May 2020

Neutrosophic components (NC) under addition and product form different algebraic structures over different intervals. In this paper authors for the first time define the usual product and sum operations on NC. Here four different NC are defined using the four different intervals: (0, 1), [0, 1), (0, 1] and [0, 1]. In the neutrosophic components we assume the truth value or the false value or the indeterminate value to be from the intervals (0, 1) or [0, 1) or (0, 1] or [0, 1]. All the operations defined on these neutrosophic components on the four intervals are symmetric. In all the four cases the NC collection happens to be a semigroup under product. All of them are torsion free semigroups or weakly torsion free semigroups. The NC defined on the interval [0, 1) happens to be a group under addition modulo 1. Further it is proved the NC defined on the interval [0, 1) is an infinite commutative ring under addition modulo 1 and usual product with infinite number of zero divisors and the ring has no unit element. We define multiset NC semigroup using the four intervals. Finally, we define n-multiplicity multiset NC semigroup for finite n and these two structures are semigroups under + modulo 1 and { M ( S ) , + , × } and { n - M ( S ) , + , × } are NC multiset semirings. Several interesting properties are discussed about these structures.
Optimal Investment, Consumption and Leisure with an Option to File for Bankruptcy
Authors: Lim Byung Hwa , Lee Ho-Seok
Published: May 2020

This paper investigates the optimal personal bankruptcy decision of a debtor who participates in the labor market. This paper is based on a mathematical finance model that assumes a Black-Scholes financial market and describes a decision problem as an expected discounted utility maximization problem. Our optimization problem can be cast into a mixed optimal stopping and control problem, and has a symmetry feature with a voluntary retirement decision problem in characterizing the stopping times. To obtain value function and optimal strategies, we use dynamic programming method and transform the relevant nonlinear Bellman equation into a linear equation. Numerical illustrations from our explicit expressions for the optimal strategies reveal how an opportunity to file for bankruptcy affects debtor’s consumption, leisure, and portfolio decisions.
Multi-Stress Induction of the Mycobacterium tuberculosis MbcTA Bactericidal Toxin-Antitoxin System
Authors: Ariyachaokun Kanchiyaphat , Grabowska Anna D. , Gutierrez Claude , Neyrolles Olivier
Published: May 2020

MbcTA is a type II toxin/antitoxin (TA) system of Mycobacterium tuberculosis. The MbcT toxin triggers mycobacterial cell death in vitro and in vivo through the phosphorolysis of the essential metabolite NAD+ and its bactericidal activity is neutralized by physical interaction with its cognate antitoxin MbcA. Therefore, the MbcTA system appears as a promising target for the development of novel therapies against tuberculosis, through the identification of compounds able to antagonize or destabilize the MbcA antitoxin. Here, the expression of the mbcAT operon and its regulation were investigated. A dual fluorescent reporter system was developed, based on an integrative mycobacterial plasmid that encodes a constitutively expressed reporter, serving as an internal standard for monitoring mycobacterial gene expression, and an additional reporter, dependent on the promoter under investigation. This system was used both in M. tuberculosis and in the fast growing model species Mycobacterium smegmatis to: (i) assess the autoregulation of mbcAT; (ii) perform a genetic dissection of the mbcA promoter/operator region; and (iii) explore the regulation of mbcAT transcription from the mbcA promoter (PmbcA) in a variety of stress conditions, including in vivo in mice and in macrophages.