bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of Polysulfone Membrane via Vapor-Induced Phase Separation for Oil/Water Emulsion Filtration
Authors: Barambu Nafiu Umar , Bilad Muhammad Roil , Bustam Mohamad Azmi , Huda Nurul , Jaafar Juhana , Narkkun Thanitporn , Faungnawakij Kajornsak
Published: October 2020

The discharge of improperly treated oil/water emulsion by industries imposes detrimental effects on human health and the environment. The membrane process is a promising technology for oil/water emulsion treatment. However, it faces the challenge of being maintaining due to membrane fouling. It occurs as a result of the strong interaction between the hydrophobic oil droplets and the hydrophobic membrane surface. This issue has attracted research interest in developing the membrane material that possesses high hydraulic and fouling resistance performances. This research explores the vapor-induced phase separation (VIPS) method for the fabrication of a hydrophilic polysulfone (PSF) membrane with the presence of polyethylene glycol (PEG) as the additive for the treatment of oil/water emulsion. Results show that the slow nonsolvent intake in VIPS greatly influences the resulting membrane structure that allows the higher retention of the additive within the membrane matrix. By extending the exposure time of the cast film under humid air, both surface chemistry and morphology of the resulting membrane can be enhanced. By extending the exposure time from 0 to 60 s, the water contact angle decreases from 70.28 ± 0.61° to 57.72 ± 0.61°, and the clean water permeability increases from 328.70 ± 8.27 to 501.89 ± 8.92 (L·m−2·h−1·bar−1). Moreover, the oil rejection also improves from 85.06 ± 1.6 to 98.48 ± 1.2%. The membrane structure was transformed from a porous top layer with a finger-like macrovoid sub-structure to a relatively thick top layer with a sponge-like macrovoid-free sub-structure. Overall results demonstrate the potential of the VIPS process to enhance both surface chemistry and morphology of the PSF membrane.
Chemical Modification of Pullulan Exopolysaccharide by Grafting Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBHV) via Click Chemistry
Authors: T. de Carvalho Layde , da S. Paula Maria Luiza , M. de Moraes Rodolfo , Alves Gizelda M. , M. Lacerda Talita , Santos Julio C. dos , M. dos Santos Amilton , Medeiros Simone de F.
Published: October 2020

Biodegradable and biocompatible copolymers have been often studied for the development of biomaterials for drug delivery systems. In this context, this work reports the synthesis and characterization of a novel pullulan-g-poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (Pull-g-PHBHV) graft copolymer using click chemistry. Well-defined and functional pullulan backbones containing azide groups (PullN3) previously prepared by our group were successfully used for this purpose and propargyl-terminated poly(3-hydroxybutyrate-co-3-hydroxyvalerate) was prepared via transesterification using propargyl alcohol as a chain transfer agent. By an alkyne-azide cycloaddition reaction catalyzed by copper (Cu (I)) (CuAAC), the graft copolymer Pull-g-PHBHV was obtained. The chemical structures of the polymers were accessed by 1H NMR and 13C NMR FTIR. Disappearance of the bands referring to the main bonds evidenced success in the grafting reaction. Besides that, DRX, DSC and TGA were used in order to access the changes in crystallinity and thermal behavior of the material. The remaining crystallinity of the Pull-g-PHBHV structure evidences the presence of PHBHV. Pull-g-PHBHV presented lower degradation maximum temperature values than the starting materials, indicating its minor thermal stability. Finally, the synthesized material is an innovative biopolymer, which has never been reported in the previous literature. It is a bio-derived and biodegradable polymer, chemically modified, resulting in interesting properties which can be useful for their further applications as biomedical systems for controlled delivery, for example.
Key Role of the Dispersion of Carbon Nanotubes (CNTs) within Epoxy Networks on their Ability to Release
Authors: Pras Maxime , Gérard Jean-François , Golanski Luana , Quintard Guilhem , Duchet-Rumeau Jannick
Published: October 2020

Carbon nanotube (CNT)-reinforced nanocomposites represent a unique opportunity in terms of designing advanced materials with mechanical reinforcement and improvements in the electrical and thermal conductivities. However, the toxic effects of these composites on human health have been studied, and very soon, some regulations on CNTs and on composites based on CNTs will be enacted. That is why the release of CNTs during the nanocomposite lifecycle must be controlled. As the releasing depends on the interfacial strength that is stronger between CNTs and polymers compared to CNTs in a CNT agglomerate, two dispersion states—one poorly dispersed versus another well dispersed—are generated and finely described. So, the main aim of this study is to check if the CNT dispersion state has an influence on the CNT releasing potential in the nanocomposite. To well tailor and characterize the CNT dispersion state in the polymer matrix, electronic microscopies (SEM and TEM) and also rheological analysis are carried out to identify whether CNTs are isolated, in bundles, or in agglomerates. When the dispersion state is known and controlled, its influence on the polymerization kinetic and on mechanical properties is discussed. It appears clearly that in the case of a good dispersion state, strong interfaces are generated, linking the isolated nanotubes with the polymer, whereas the CNT cohesion in an agglomerate seems much more weak, and it does not provide any improvement to the polymer matrix. Raman spectroscopy is relevant to analyze the interfacial properties and allows the relationship with the releasing ability of nanocomposites; i.e., CNTs poorly dispersed in the matrix are more readily released when compared to well-dispersed nanocomposites. The tribological tests confirm from released particles granulometry and observations that a CNT dispersion state sufficiently achieved in the nanocomposite avoids single CNT releasing under those solicitations.
Synthesis of a Novel Spirocyclic Inflatable Flame Retardant and Its Application in Epoxy Composites
Authors: Song Kunpeng , Wang Yinjie , Ruan Fang , Yang Weiwei , Liu Jiping
Published: October 2020

Derivatives of 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro-[5,5]undecane-3,9-dioxide (SPDPC) are of increasing interest as flame retardants for polymeric materials. In addition, SPDPC is also an important intermediate for the preparation of intumescent flame retardants (IFRs). However, low efficiency and undesirable dispersion are two major problems that seriously restrain the application of IFRs as appropriate flame retardants for polymer materials. Usually, the functionalization or modification of SPDPC is crucial to acquiring high-performance polymer composites. Here, a small molecule spirocyclic flame retardant diphenylimidazole spirocyclic pentaerythritol bisphosphonate (PIPC) was successfully prepared through the substitution reaction between previously synthesized intermediate SPDPC and 2-phenylimidazole (PIM). Phenyl group and imidazole group were uniformly anchored on the molecular structure of SPDPC. This kind of more uniform distribution of flame retardant groups within the epoxy matrix resulted in a synergistic flame retardant effect and enhanced the strength of char layers to the epoxy composites, when compared to the unmodified epoxy. The sample reached a limiting oxygen index (LOI) of 29.7% and passed with a V-0 rating in the UL 94 test with the incorporation of only 5 wt% of as-prepared flame retardant PIPC. Moreover, its peak of heat release rate (pHRR) and total heat release (THR) decreased by 41.15% and 21.64% in a cone calorimeter test, respectively. Furthermore, the addition of PIPC has only slightly impacted the mechanical properties of epoxy composites with a low loading.
3D Printing of Oil Paintings Based on Material Jetting and Its Reduction of Staircase Effect
Authors: Yuan Jiangping , Chen Chen , Yao Danyang , Chen Guangxue
Published: October 2020

Material jetting is a high-precision and fast 3D printing technique for color 3D objects reproduction, but it also suffers from color accuracy and jagged issues. The UV inks jetting processes based on the polymer jetting principle have been studied from printing materials regarding the parameters in the default layer order, which is prone to staircase effects. In this work, utilizing the Mimaki UV inks jetting system with a variable layer thickness, a new framework to print a photogrammetry-based oil painting 3D model has been proposed with the tunable coloring layer sequence to improve the jagged challenge between adjacent layers. Based on contour tracking, a height-rendering image of the oil painting model is generated, which is further segmented and pasted to the corresponding slicing layers to control the overall printing sequence of coloring layers and white layers. The final results show that photogrammetric models of oil paintings can be printed vividly by UV-curable color polymers, and that the proposed reverse-sequence printing method can significantly improve the staircase effect based on visual assessment and color difference. Finally, the case of polymer-based oil painting 3D printing provides new insights for optimizing color 3D printing processes based on other substrates and print accuracy to improve the corresponding staircase effect.
Characterization of Porous Structures of Cellulose Nanofibrils Loaded with Salicylic Acid
Authors: McDonagh Birgitte Hjelmeland , Chinga-Carrasco Gary
Published: October 2020

Bleached and unbleached pulp fibers were treated with 2,2,6,6-tetramethylpyperidine-1-oxyl (TEMPO) mediated oxidation to obtain cellulose nanofibrils (CNFs). The resulting bleached and unbleached CNFs were mixed with salicylic acid (0, 5, 10, 20 wt%) before casting and freeze-drying or 3D-printing. A series of methods were tested and implemented to characterize the CNF materials and the porous structures loaded with salicylic acid. The CNFs were characterized with atomic force microscopy and laser profilometry, and release of salicylic acid was quantified with UV-visible absorbance spectroscopy, conductivity measurements, and inductive coupled plasma mass spectrometry (ICP-MS). Fourier-transform infrared spectroscopy (FTIR) complemented the analyses. Herein, we show that aerogels of bleached CNFs yield a greater release of salicylic acid, compared to CNF obtained from unbleached pulp. The results suggest that biodegradable constructs of CNFs can be loaded with a plant hormone that is released slowly over time, which may find uses in small scale agricultural applications and for the private home market.
Improving Local Climate Zone Classification Using Incomplete Building Data and Sentinel 2 Images Based on Convolutional Neural Networks
Authors: Yoo Cheolhee , Lee Yeonsu , Cho Dongjin , Im Jungho , Han Daehyeon
Published: October 2020

Recent studies have enhanced the mapping performance of the local climate zone (LCZ), a standard framework for evaluating urban form and function for urban heat island research, through remote sensing (RS) images and deep learning classifiers such as convolutional neural networks (CNNs). The accuracy in the urban-type LCZ (LCZ1-10), however, remains relatively low because RS data cannot provide vertical or horizontal building components in detail. Geographic information system (GIS)-based building datasets can be used as primary sources in LCZ classification, but there is a limit to using them as input data for CNN due to their incompleteness. This study proposes novel methods to classify LCZ using Sentinel 2 images and incomplete building data based on a CNN classifier. We designed three schemes (S1, S2, and a scheme fusion; SF) for mapping 50 m LCZs in two megacities: Berlin and Seoul. S1 used only RS images, and S2 used RS and building components such as area and height (or the number of stories). SF combined two schemes (S1 and S2) based on three conditions, mainly focusing on the confidence level of the CNN classifier. When compared to S1, the overall accuracies for all LCZ classes (OA) and the urban-type LCZ (OAurb) of SF increased by about 4% and 7–9%, respectively, for the two study areas. This study shows that SF can compensate for the imperfections in the building data, which causes misclassifications in S2. The suggested approach can be excellent guidance to produce a high accuracy LCZ map for cities where building databases can be obtained, even if they are incomplete.
A Kinematic Model of a Humanoid Lower Limb Exoskeleton with Hydraulic Actuators
Authors: Glowinski Sebastian , Krzyzynski Tomasz , Bryndal Aleksandra , Maciejewski Igor
Published: October 2020

Although it is well-established that exoskeletons as robots attached to the extremities of the human body increase their strength, limited studies presented a computer and mathematical model of a human leg hydraulic exoskeleton based on anthropometric data. This study aimed to examine lower limb joint angles during walking and running by using Inertial Measurement Units. The geometry and kinematic parameters were calculated. Twenty-six healthy adults participated in walking and running experiments. The geometric model of a human leg hydraulic exoskeleton was presented. Joint angle data acquired during experiments were used in the mathematical model. The position and velocity of exoskeleton actuators in each phase of movement were calculated using the MATLAB package (Matlab_R2017b, The MathWorks Company, Novi, MI, USA). The highest velocity of the knee actuator during walking and running was in the swing phase, 0.3 and 0.4 m/s, respectively. For the ankle and hip joints, the highest velocity of actuators occurred during the push-off phase. The results with 26 healthy subjects demonstrated that the system's compliance can be effectively adjusted while guiding the subjects walking in predefined trajectories. The developed mathematical model makes it possible to determine the position of lower limb segments and exoskeleton elements. The proposed model allows for calculating the position of the human leg and actuators’ characteristic points.
Advances in Random Fiber Lasers and Their Sensing Application
Authors: Chen Hong , Gao Shaohua , Zhang Mingjiang , Zhang Jianzhong , Qiao Lijun , Wang Tao , Gao Fei , Hu Xinxin , Li Shichuan , Zhu Yicheng
Published: October 2020

Compared with conventional laser, random laser (RL) has no resonant cavity, reducing the requirement of cavity design. In recent years, the random fiber laser (RFL), a novel kind of RL, has made great progress in theories and experiments. The RFL has a simpler structure, a more flexible design, and higher reliability. It has valuable applications for earth sciences, biological life sciences, and national defense security, due to these unique properties. This paper reviews the development of RFLs in the last decade, including their configurations based on various optical fibers and their output properties, especially the method of control. Moreover, we also introduce their applications in the optical fiber sensing system, which is a very important and practical orientation to study. Finally, this paper presents the prospects of RFLs.
Active Disturbance Rejection Position Synchronous Control of Dual-Hydraulic Actuators with Unknown Dead-Zones
Authors: Wang Lixin , Zhao Dingxuan , Liu Fucai , Liu Qian , Zhang Zhuxin
Published: October 2020

In this paper, an integrated control strategy of position synchronization control for dual-electro-hydraulic actuators with unknown dead-zones is proposed. The unified control scheme consists of two parts: One is adaptive dead-zone inverse controllers of each hydraulic actuator to offset the unknown dead-zones. The other is the linear active disturbance rejection controller (LADRC) for position synchronization error. First, the model of the electro-hydraulic proportional position control system (EPPS) was identified by the forgetting factor recursive least square (FFRLS) algorithm. Next, the model reference dead-zone inverse adaptive controller (MRDIAC) was developed to compensate for the delay of actuator response caused by unknown proportional valve dead-zones. Meanwhile, the validity of the adaptive law was proven by the Lyapunov theory. Therefore, the position control accuracy of each hydraulic actuator is guaranteed. Besides, to improve the precision of position synchronization control of dual-hydraulic actuators, a simple and elegant synchronous error-based LADRC was adopted, which applies the total disturbances design concept to eliminate and compensate for motion coupling rather than cross-coupling technology. The performance of the proposed control solution was investigated through extensive comparative experiments based on a hydraulic test platform. The experimental results successfully demonstrate the effectiveness and practicality of the proposed method.
Improved Performance of SRAM-Based True Random Number Generator by Leveraging Irradiation Exposure
Authors: Zhang Xu , Jiang Chunsheng , Dai Gang , Zhong Le , Fang Wen , Gu Ke , Xiao Guoping , Ren Shangqing , Liu Xin , Zou Sanyong
Published: October 2020

Encryption is an important step for secure data transmission, and a true random number generator (TRNG) is a key building block in many encryption algorithms. Static random-access memory (SRAM) chips can be easily available sources of true random numbers, benefiting from noisy SRAM cells whose start-up values flip between different power-on cycles. Embarking from this phenomenon, a novel performance (i.e., randomness and throughput) improvement method of SRAM-based TRNG is proposed, and its implementation can be divided into two phases: irradiation exposure and hardware postprocessing. As the randomness of original SRAM power-on values is fairly low, ionization irradiation is utilized to enhance its randomness, and the min-entropy can increase from about 0.03 to above 0.7 in the total ionizing irradiation (TID) experiments. Additionally, while the data remanence effect hampers obtaining random bitstreams with high speed, the ionization irradiation can also weaken this impact and improve the throughput of TRNG. In the hardware postprocessing stage, Secure Hash Algorithm 256 (SHA-256) is implemented on a Field Programmable Gate Array (FPGA) with clock frequency of 200 MHz. It can generate National Institute of Standards and Technology (NIST) SP 800-22 compatible true random bitstreams with throughput of 178 Mbps utilizing SRAM chip with 1 Mbit memory capacity. Furthermore, according to different application scenarios, the throughput can be widely scalable by adjusting clock frequency and SRAM memory capacity, which makes the novel TRNG design applicable for various Internet of Things (IOT) devices.
SoC FPGA Accelerated Sub-Optimized Binary Fully Convolutional Neural Network for Robotic Floor Region Segmentation
Authors: Sun Chi-Chia , Ahamad Afaroj , Liu Pin-He
Published: October 2020

In this article, a new Binary Fully Convolutional Neural Network (B-FCN) based on Taguchi method sub-optimization for the segmentation of robotic floor regions, which can precisely distinguish floor regions in complex indoor environments is proposed. This methodology is quite suitable for robot vision in an embedded platform and the segmentation accuracy is up to 84.80% on average. A total of 6000 training datasets were used to improve the accuracy and reach convergence. On the other hand, to reach real-time computation, a PYNQ FPGA platform with heterogeneous computing acceleration was used to accelerate the proposed B-FCN architecture. Overall, robots would benefit from better navigation and route planning in our approach. The FPGA synthesis of our binarization method indicates an efficient reduction in the BRAM size to 0.5–1% and also GOPS/W is sufficiently high. Notably, the proposed faster architecture is ideal for low power embedded devices that need to solve the shortest path problem, path searching, and motion planning.
A Novel Ensemble Adaptive Sparse Bayesian Transfer Learning Machine for Nonlinear Large-Scale Process Monitoring
Authors: Cheng Hongchao , Liu Yiqi , Huang Daoping , Xu Chong , Wu Jing
Published: October 2020

Process monitoring plays an important role in ensuring the safety and stable operation of equipment in a large-scale process. This paper proposes a novel data-driven process monitoring framework, termed the ensemble adaptive sparse Bayesian transfer learning machine (EAdspB-TLM), for nonlinear fault diagnosis. The proposed framework has the following advantages: Firstly, the probabilistic relevance vector machine (PrRVM) under Bayesian framework is re-derived so that it can be used to forecast the plant operating conditions. Secondly, we extend the PrRVM method and assimilate transfer learning into the sparse Bayesian learning framework to provide it with the transferring ability. Thirdly, the source domain (SD) data are re-enabled to alleviate the issue of insufficient training data. Finally, the proposed EAdspB-TLM framework was effectively applied to monitor a real wastewater treatment process (WWTP) and a Tennessee Eastman chemical process (TECP). The results further demonstrate that the proposed method is feasible.
A Non-Invasive Soil Moisture Sensing System Electronic Architecture: A Real Environment Assessment
Authors: Franceschelli Leonardo , Berardinelli Annachiara , Crescentini Marco , Iaccheri Eleonora , Tartagni Marco , Ragni Luigi
Published: October 2020

This paper will show the electronic architecture of a portable and non-invasive soil moisture system based on an open rectangular waveguide. The spectral information, measured in the range of 1.5–2.7 GHz, is elaborated on by an embedded predictive model, based on a partial least squares (PLS) regression tool, for the estimation of the soil moisture (%) in a real environment. The proposed system is composed of a waveguide, containing Tx and Rx antennas, and an electronic circuit driven by a microcontroller (MCU). It will be shown how the system provides a useful and fast estimation of moisture on a silty clay loam soil characterized by a moisture range of about 9% to 32% and a soil temperature ranging from about 8 °C and 18 °C. Using the PLS approach, the moisture content can be predicted with an R2 value of 0.892, a root mean square error (RMSE) of 1.0%, and a residual prediction deviation (RPD) of 4.3. The results prove that it is possible to make accurate and rapid moisture assessments without the use of invasive electrodes, as currently employed by state-of-the-art approaches.
A Body Tracking-Based Low-Cost Solution for Monitoring Workers’ Hygiene Best Practices during Pandemics
Authors: Manghisi Vito M. , Fiorentino Michele , Boccaccio Antonio , Gattullo Michele , Cascella Giuseppe L. , Toschi Nicola , Pietroiusti Antonio , Uva Antonio E.
Published: October 2020

Since its beginning at the end of 2019, the pandemic spread of the severe acute respiratory syndrome coronavirus 2 (Sars-CoV-2) caused more than one million deaths in only nine months. The threat of emerging and re-emerging infectious diseases exists as an imminent threat to human health. It is essential to implement adequate hygiene best practices to break the contagion chain and enhance society preparedness for such critical scenarios and understand the relevance of each disease transmission route. As the unconscious hand–face contact gesture constitutes a potential pathway of contagion, in this paper, the authors present a prototype system based on low-cost depth sensors able to monitor in real-time the attitude towards such a habit. The system records people’s behavior to enhance their awareness by providing real-time warnings, providing for statistical reports for designing proper hygiene solutions, and better understanding the role of such route of contagion. A preliminary validation study measured an overall accuracy of 91%. A Cohen’s Kappa equal to 0.876 supports rejecting the hypothesis that such accuracy is accidental. Low-cost body tracking technologies can effectively support monitoring compliance with hygiene best practices and training people in real-time. By collecting data and analyzing them with respect to people categories and contagion statistics, it could be possible to understand the importance of this contagion pathway and identify for which people category such a behavioral attitude constitutes a significant risk.
A Novel Error Correction Approach to Improve Standard Point Positioning of Integrated BDS/GPS
Authors: Du Luyao , Ji Jing , Pei Zhonghui , Chen Wei
Published: October 2020

To improve the standard point positioning (SPP) accuracy of integrated BDS (BeiDou Navigation Satellite System)/GPS (Global Positioning System) at the receiver end, a novel approach based on Long Short-Term Memory (LSTM) error correction recurrent neural network is proposed and implemented to reduce the error caused by multiple sources. On the basis of the weighted least square (WLS) method and Kalman filter, the proposed LSTM-based algorithms, named WLS–LSTM and Kalman–LSTM error correction methods, are used to predict the positioning error of the next epoch, and the prediction result is used to correct the next epoch error. Based on the measured data, the results of the weighted least square method, the Kalman filter method and the LSTM error correction method were compared and analyzed. The dynamic test was also conducted, and the experimental results in dynamic scenarios were analyzed. From the experimental results, the three-dimensional point positioning error of Kalman–LSTM error correction method is 1.038 m, while the error of weighted least square method, Kalman filter and WLS–LSTM error correction method are 3.498, 3.406 and 1.782 m, respectively. The positioning error is 3.7399 m and the corrected positioning error is 0.7493 m in a dynamic scene. The results show that the LSTM-based error correction method can improve the standard point positioning accuracy of integrated BDS/GPS significantly.
Ratiometric Sensor Based on PtOEP-C6/Poly (St-TFEMA) Film for Automatic Dissolved Oxygen Content Detection
Authors: Zhang Honglin , Zhang Zhiguo
Published: October 2020

A ratiometric oxygen sensor based on a platinum octaethylporphyrin (PtOEP)–coumarin 6 (C6)/poly (styrene-trifluoroethyl methacrylate) (poly (St-TFEMA)) film was developed for automatic dissolved oxygen (DO) detection. The oxygen-sensing film according to the dynamic quenching mechanism was prepared by embedding platinum octaethylporphyrin (PtOEP) and coumarin 6 (C6) in poly (styrene-trifluoroethyl methacrylate) (poly (St-TFEMA)). The optical parameter (OP) was defined as the ratio of the oxygen-insensitive fluorescence from C6 to the oxygen-sensitive phosphorescence from PtOEP. A calibration equation expressing the correlation between the OP values and DO content described by a linear function was obtained. A program based on the Labview software was developed for monitoring the real-time DO content automatically. The influence of the excitation intensity and fluctuation on the OP values and the direct luminescence signal (integration areas) was compared, verifying the strong anti-interference ability of the sensor. The detection limit of the sensor was determined to be 0.10 (1) mg/L. The switching response time and recovery time of the sensor were 0.4 and 1.3 s, respectively. Finally, the oxygen sensor was applied to the investigation of the kinetic process of the DO content variation, which revealed an exponential relationship with time.
Depth Estimation for Light-Field Images Using Stereo Matching and Convolutional Neural Networks
Authors: Rogge Ségolène , Schiopu Ionut , Munteanu Adrian
Published: October 2020

The paper presents a novel depth-estimation method for light-field (LF) images based on innovative multi-stereo matching and machine-learning techniques. In the first stage, a novel block-based stereo matching algorithm is employed to compute the initial estimation. The proposed algorithm is specifically designed to operate on any pair of sub-aperture images (SAIs) in the LF image and to compute the pair’s corresponding disparity map. For the central SAI, a disparity fusion technique is proposed to compute the initial disparity map based on all available pairwise disparities. In the second stage, a novel pixel-wise deep-learning (DL)-based method for residual error prediction is employed to further refine the disparity estimation. A novel neural network architecture is proposed based on a new structure of layers. The proposed DL-based method is employed to predict the residual error of the initial estimation and to refine the final disparity map. The experimental results demonstrate the superiority of the proposed framework and reveal that the proposed method achieves an average improvement of 15.65% in root mean squared error (RMSE), 43.62% in mean absolute error (MAE), and 5.03% in structural similarity index (SSIM) over machine-learning-based state-of-the-art methods.
Image Inpainting Using Two-Stage Loss Function and Global and Local Markovian Discriminators
Authors: Li Chen , He Kai , Liu Kun , Ma Xitao
Published: October 2020

Image inpainting networks can produce visually reasonable results in the damaged regions. However, existing inpainting networks may fail to reconstruct the proper structures or tend to generate the results with color discrepancy. To solve this issue, this paper proposes an image inpainting approach using the proposed two-stage loss function. The loss function consists of different Gaussian kernels, which are utilized in different stages of network. The use of our two-stage loss function in coarse network helps to focus on the image structure, while the use of it in refinement network is helpful to restore the image details. Moreover, we proposed a global and local PatchGANs (GAN means generative adversarial network), named GL-PatchGANs, in which the global and local markovian discriminators were used to control the final results. This is beneficial to focus on the regions of interest (ROI) on different scales and tends to produce more realistic structural and textural details. We trained our network on three popular datasets on image inpainting separately, both Peak Signal to Noise ratio (PSNR) and Structural Similarity (SSIM) between our results, and ground truths on test images show that our network can achieve better performance compared with the recent works in most cases. Besides, the visual results on three datasets also show that our network can produce visual plausible results compared with the recent works.
Rainfall Trend and Its Relationship with Normalized Difference Vegetation Index in a Restored Semi-Arid Wetland of South Africa
Authors: Murungweni Florence M. , Mutanga Onisimo , Odiyo John O.
Published: October 2020

Clearance of terrestrial wetland vegetation and rainfall variations affect biodiversity. The rainfall trend–NDVI (Normalized Difference Vegetation Index) relationship was examined to assess the extent to which rainfall affects vegetation productivity within Nylsvley, Ramsar site in Limpopo Province, South Africa. Daily rainfall data measured from eight rainfall stations between 1950 and 2016 were used to generate seasonal and annual rainfall data. Mann-Kendall and quantile regression were applied to assess trends in rainfall data. NDVI was derived from satellite images from between 1984 and 2003 using Zonal statistics and correlated with rainfall of the same period to assess vegetation dynamics. Mann-Kendall and Sen’s slope estimator showed only one station had a significant increasing rainfall trend annually and seasonally at p < 0.05, whereas all the other stations showed insignificant trends in both rainfall seasons. Quantile regression showed 50% and 62.5% of the stations had increasing annual and seasonal rainfall, respectively. Of the stations, 37.5% were statistically significant at p < 0.05, indicating increasing and decreasing rainfall trends. These rainfall trends show that the rainfall of Nylsvley decreased between 1995 and 2003. The R2 between rainfall and NDVI of Nylsvley is 55% indicating the influence of rainfall variability on vegetation productivity. The results underscore the impact of decadal rainfall patterns on wetland ecosystem change.
Construction Management Solutions to Mitigate Elevator Noise and Vibration of High-Rise Residential Buildings
Authors: Oh Yangki , Kang Minwoo , Lee Kwangchae , Kim Sunkuk
Published: October 2020

In high-rise residential buildings (HRBs), elevators run at a high speed, which causes problems such as change of atmospheric pressure, noise, and vibration. Elevator noise and vibration (ENV) of HRBs causes both mental anxiety and a consistently negative effect for promoting a comfortable residential area. Therefore, a solution for alleviating the ENV of HRBs is essential. To date, studies related to ENV have been mostly conducted in the approach of mechanical and electric aspects. There have been few cases conducted from the perspective of construction management (CM), which integrates design and construction. Therefore, the aim of this study is to propose CM solutions to mitigate the ENV of HRB. For this study, the CM solution is presented after identifying the ENV problems of HRBs through documented research and case measurement. By measuring the noise of HRB that the solution was applied to, the noise level, especially in a range of >125 Hz, was extensively reduced. The result of this study will be used as sustainable guidelines that alleviate ENV problems in the process of design and construction of HRB elevators. It is expected that studies for improving ENV problems that occur in high-rise elevators will increase on the basis of the results of this study.
Polish Consumers’ Response to Social Media Eco-Marketing Techniques
Authors: Bojanowska Agnieszka , Kulisz Monika
Published: October 2020

This study attempts to verify whether green-marketing efforts of companies are recognised by the Polish customer in social media—a vital marketing communication channel. For businesses, this awareness carries important implications for the effectiveness and profitability of the eco-marketing campaigns. This study employed survey methodology, which was coupled with participant observation of online ecology-centred communities. It is shown that the economic aspect of green marketing is valued by customers and they are quite observant with respect to such expressions of eco-marketing as eco-organic product packaging or production in the spirit of zero-waste technology. The results indicate that eco-marketing activities should be predominantly targeted at women because they are more likely to take note of the message. The statistical part of the study utilises the Chi-square (χ2) test (significance level α = 0.05) and the gamma distribution. Eco-marketing activities appear to attract notice in social media, but not yet as much as presumably desired. Gender is shown to correlate with respect to questions regarding the noticeability of zero-waste activities and pro-ecological activities in social media. Women display higher awareness of “zero-waste” and pro-ecological social media campaigns. In the aggregate, those who perceive “zero waste” as a lifestyle include women, who are more observant.
Application of Hybrid SWARA–BIM in Reducing Reworks of Building Construction Projects from the Perspective of Time
Authors: Khalesi Hamidreza , Balali Amirhossein , Valipour Alireza , Antucheviciene Jurgita , Migilinskas Darius , Zigmund Viaceslav
Published: October 2020

One of the major issues of the construction industry has been the “reworks” that affect the time, quality, and cost of projects. Therefore, reworks and the ineffective use of site resources and materials will always result in significant losses on projects. The development of information technology has led to the widespread use of Building Information Modelling (BIM) to enhance the delivery of more sustainable building construction projects. The purpose of this study is to combine the Step-wise Weight Assessment Ratio Analysis (SWARA) method and BIM technologies to identify and reduce time delays caused by reworks in construction projects. Firstly, 49 rework causes in residential buildings were identified and ranked. Then, BIM was generated and compared to the initial model. It was observed that working hours were reduced by 4.6%. Moreover, using an Earned Value Management (EVM) system, a 0.06 increase in Schedule Performance Index (SPI) factor was illustrated. Results obtained by this study provide an effective step in reducing a project’s time in the construction industry.
Announcement Effects of Convertible and Warrant Bond Issues with Embedded Refixing Option: Evidence from Korea
Authors: Kim Yongsik
Published: October 2020

This study examines the announcement effects of convertible and warrant bond issues with embedded refixing option in Korea from January 2001 to December 2018. Refixing option denotes an adjustment right of the conversion price embedded in equity-linked debt when the underlying stock price falls under conversion price. I find statistically significant declines of 2.6 to 2.7 percentage points in cumulative abnormal returns for the inclusion of a refixing clause and especially further declines of 6.2 to 6.3 percentage points during the period from 2016 to 2018. This result implies that the market’s concerns about the dilution of existing shareholder value due to the exercise of the refixing rights are reflected in the market response. I further find that the degree of negative market response varies according to the changes in macroeconomic conditions and the stock exchange on which the issuing firms are listed. The findings are robust after controlling for the effect of firm-, issue-, and market-specific characteristics.
Field Performance of Allelopathic Bacteria for Biological Weed Control in Wheat: Innovative, Sustainable and Eco-Friendly Approach for Enhanced Crop Production
Authors: Abbas Tasawar , Zahir Zahir Ahmad , Naveed Muhammad , Alwahibi Mona S. , Soliman Elshikh Mohamed , A. El-Esawi Mohamed
Published: October 2020

Application of allelopathic bacteria (AB) for weed suppression may be helpful to solve various environmental challenges posed by conventional weed control techniques. In our earlier studies, around 400 strains of rhizobacteria of five weeds and wheat were isolated, screened for production of phytotoxic substances, and tested for phytotoxic activity on wild oat and little seed canary grass, and possible effects on wheat under laboratory conditions. We obtained 13 strains inhibitory to wild oat (Avena fatua L.) and 11 to little seed canary grass (Phalaris minor Retz.). Five of these (13 and 11) strains also suppressed wheat (Triticum aestivum L.) while others either stimulated or remained ineffective on wheat in separate bioassays. The success of any weed biocontrol technique, however, depends on its response under field conditions. Therefore, the present study was conducted to investigate biological weed control of the five most efficient strains of AB under natural conditions in pot and field trials. Wheat was artificially invaded with wild oat in the pot trial through seeding. Wheat of the field trial was artificially invaded with wild oat and little seed canary through seeding. The selected strains belonged to pseudomonads (Pseudomonas putida, P. fluorescence, P. aeruginosa, and P. alcaligenes) and their inocula were prepared using sterilized peat. The inoculated seeds of wild oat and wheat were sown together in a pot trial. The inoculated seeds of wild oat, little seed canary grass, and wheat were sown together in the field experiment. The field was selected based on chronic infestation of these weeds. However, weed invasion was ensured by adding seeds of weeds (inoculated with the respective strains of AB, according to treatment plan). A severe invasion of wild oat was observed in the pot trial, which reduced the grain yield of infested wheat up to 60.8%. The effectiveness of applied strains controlled 22.0–76.3% loss of grain yield of infested wheat. Weed invasion in the field trial reduced the grain yield of the crop up to 56.3% and effectiveness of the applied strains controlled 29.0–60.7% loss of grain yield of infested wheat. The study of other agronomic, physiological, and chemical parameters of the crop and weeds supported these findings. Harnessing the potential of these strains exhibited in our studies may be helpful to introduce an innovative, sustainable, and eco-friendly weed control technique for production of wheat.
Environmental Overcost of Single Family Houses in Insular Context: A Comparative LCA Study of Reunion Island and France
Authors: Ayagapin Leslie , Praene Jean Philippe
Published: October 2020

The building and public works sector is, in France as in Europe, a major consumer of raw materials for both the manufacture of products and the construction of buildings and structures. This sector has a direct impact on the natural and built environment. This effect is even more pronounced in the case of isolated territories, such as islands. The latter have their own constraints (geographical location, production of the local grid mix) and particularities: very small territory, massive importation of goods in all fields, such as food, automobile, building, and others). In this study, we focus on the building branch of the construction industry, which covers housing (single-family houses and apartment blocks). The study is based on the analysis of about twenty single-family houses built in metropolitan France and Reunion Island. The construction standards for these two regions comply with European standards (CE) and French regulations. However, in the case of Reunion Island, a tropical island, it applies in particular to the Thermal, Acoustic, and Ventilation Regulations for New Buildings in Overseas Departments and Regions (RTAA DROM). The approach that is used for the environmental assessment of single-family homes is the Life Cycle Assessment (LCA), from cradle to grave. The results initially showed that there is an additional environmental cost in the construction sector between France and Reunion Island. This is initially due to the choice of origin of materials and products, which can greatly contribute to the impacts of construction. Secondly, to the use of the countries’ electricity mix, which also contributes, in part, to the impact of the construction of these single-family homes during the assembly and transformation of the products. Finally, this additional cost also differs according to the transport used (sea, air, rail, road). For the Global Warming Potential (GWP) indicator, in our study we note that the additional environmental cost is 37% higher in Reunion Island. This figure explains the additional impact of the 218 kg-CO2eq/m2 of built-up area built for Reunion Island. This study is one of the first analyses demonstrating the additional environmental cost that exists between mainland France and overseas France. Thus, the results demonstrate the importance of creating a specialized and regionalized database for the case of remote islands. Thus, this database would allow for professionals to have a precise environmental assessment, not on a national but on a regional scale. This document also provides a framework and guideline for policy decision-making in the overseas islands.
How Does Heterogeneity Affect Freeway Safety? A Simulation-Based Exploration Considering Sustainable Intelligent Connected Vehicles
Authors: Shi Yuntao , Li Ye , Cai Qing , Zhang Hao , Wu Dan
Published: October 2020

Intelligent connected vehicles (ICVs) are recognized as a new sustainable transportation mode, which could be promising for reducing crashes. However, the mixed traffic consisting of manually driven vehicles and ICVs may negatively affect road safety due to individual heterogeneity. This study investigated heterogeneity effects on freeway safety-based simulation experiments. Two types of vehicle dynamic models were employed to depict dynamic behaviors of manually driven vehicles and adaptive cruise control (ACC) vehicles (a simplified version of ICVs), respectively. Real vehicle trajectories were utilized to calibrate model parameters based on genetic algorithms. Surrogate safety measures were applied to establish the relationship between vehicle behaviors and longitudinal collision risks. Simulation results indicate that the heterogeneity has negative effects on longitudinal safety. With the higher degree of heterogeneity, longitudinal collision risks are increased. Compared to traffic flow consisting of human drivers only, mixed traffic flow may be more dangerous when the market penetration rate of ACC is low, since the ACC system can be recognized as a new source of individual heterogeneity. Findings of this study show that necessary countermeasures should be developed to improve safety for mixed traffic flow from the perspective of transportation safety planning in the near future.
Organizational Factors Affecting Charitable Giving in the Environmental Nonprofit Context
Authors: Leardini Chiara , Rossi Gina , Landi Stefano
Published: October 2020

Nonprofit organizations operating in the environmental protection and conservation sector face challenging fundraising issues in collecting from individual donors the money needed to accomplish their goals. The purpose of this study was to investigate which organizational factors can play a role in influencing the ability of these organizations to collect charitable contributions. By applying an extended version of the economic model of giving to a sample of 142 environmental nonprofits from the United States, the results of the regression analyses show that the following factors allow these organizations to attract more donations: devoting a high percentage of donations to programs, promoting the organization’s image through fundraising activities, having a large amount of assets that ensures a sustainable financial structure, and providing online information that demonstrates how the organization has dealt with its mission. Moreover, the study reveals that providing high amounts of disclosure on the organization’s website can have a conditional effect on fundraising expenses by boosting the positive effect of these expenses on donations. The results of this study contribute to the debate on the effectiveness of organizational factors in attracting funds from donors willing to support environmental nonprofits.
Entrepreneurship and Intrapreneurship in Social, Sustainable, and Economic Development: Opportunities and Challenges for Future Research
Authors: Aparicio Sebastian , Turro Andreu , Noguera Maria
Published: October 2020

Understanding entrepreneurship and intrapreneurship as engines of outcomes beyond economic terms, this paper introduces the Special Issue “Entrepreneurship and intrapreneurship in social, sustainable, and economic development”. Institutions set the basis to analyze the role societies and organizations play in supporting entrepreneurial and intrapreneurial activity. Thus, we take a broad look at formal and informal institutions as those contextual components that are encompassed in a social progress orientation. Based on this, we discuss and provide examples about how entrepreneurship and intrapreneurship lead social, sustainable, and economic outcomes. Thus, in this paper and this Issue, we argue that it is necessary to consider those (institutional) antecedents and (developmental) consequences of entrepreneurship and its diversity as a simultaneous process. In addition to summarizing the main contributions of those articles contained in this Issue, we highlight some opportunities and challenges to further explore the role of entrepreneurship and intrapreneurship not only in economic development but also in social change and sustainability.