bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of Acoustic Emission Signals Recorded during Freeze-Thaw Cycling of Concrete
Authors: Topolář Libor , Kocáb Dalibor , Pazdera Luboš , Vymazal Tomáš
Published: March 2021

This manuscript deals with a complex analysis of acoustic emission signals that were recorded during freeze-thaw cycles in test specimens produced from air-entrained concrete. An assessment of the resistance of concrete to the effects of freezing and thawing was conducted on the basis of a signal analysis. Since the experiment simulated testing of concrete in a structure, a concrete block with the height of 2.4 m and width of 1.8 m was produced to represent a real structure. When the age of the concrete was two months, samples were obtained from the block by core drilling and were subsequently used to produce test specimens. Testing of freeze-thaw resistance of concrete employed both destructive and non-destructive methods including the measurement of acoustic emission, which took place directly during the freeze-thaw cycles. The recorded acoustic emission signals were then meticulously analysed. The aim of the conducted experiments was to verify whether measurement using the acoustic emission method during Freeze-thaw (F-T) cycles are more sensitive to the degree of damage of concrete than the more commonly employed construction testing methods. The results clearly demonstrate that the acoustic emission method can reveal changes (e.g., minor cracks) in the internal structure of concrete, unlike other commonly used methods. The analysis of the acoustic emission signals using a fast Fourier transform revealed a significant shift of the dominant frequency towards lower values when the concrete was subjected to freeze-thaw cycling.
Polarization-Sensitive Light Sensors Based on a Bulk Perovskite MAPbBr3 Single Crystal
Authors: Wang Yuan , Zhu Laipan , Du Cuifeng
Published: March 2021

Organic-inorganic halide perovskites have attracted much attention thanks to their excellent optoelectronic performances. Here, a bulk CH3NH3PbBr3 (MAPbBr3) single crystal (SC) was fabricated, whose temperature and light polarization dependence was investigated by measuring photoluminescence. The presence of obvious band tail states was unveiled when the applied temperature was reduced from room temperature to 78 K. Temperature dependence of the bandgap of the MAPbBr3 SC was found to be abnormal compared with those of traditional semiconductors due to the presence of instabilization of out-of-phase tail states. The MAPbBr3 SC revealed an anisotropy light absorption for linearly polarized light with an anisotropy ratio of 1.45, and a circular dichroism ratio of up to 9% was discovered due to the spin-orbit coupling in the band tail states, exhibiting great polarization sensitivity of the MAPbBr3 SC for the application of light sensors. These key findings shed light on the development of potential optoelectronic and spintronic applications based on large-scaled organic-inorganic perovskite SCs.
Coupling Mass Spectral and Genomic Information to Improve Bacterial Natural Product Discovery Workflows
Authors: Crüsemann Max
Published: March 2021

Bacterial natural products possess potent bioactivities and high structural diversity and are typically encoded in biosynthetic gene clusters. Traditional natural product discovery approaches rely on UV- and bioassay-guided fractionation and are limited in terms of dereplication. Recent advances in mass spectrometry, sequencing and bioinformatics have led to large-scale accumulation of genomic and mass spectral data that is increasingly used for signature-based or correlation-based mass spectrometry genome mining approaches that enable rapid linking of metabolomic and genomic information to accelerate and rationalize natural product discovery. In this mini-review, these approaches are presented, and discovery examples provided. Finally, future opportunities and challenges for paired omics-based natural products discovery workflows are discussed.
Anticancer Potential of Selected Flavonols: Fisetin, Kaempferol, and Quercetin on Head and Neck Cancers
Authors: Kubina Robert , Iriti Marcello , Kabała-Dzik Agata
Published: March 2021

Flavonols are ones of the most common phytochemicals found in diets rich in fruit and vegetables. Research suggests that molecular functions of flavonoids may bring a number of health benefits to people, including the following: decrease inflammation, change disease activity, and alleviate resistance to antibiotics as well as chemotherapeutics. Their antiproliferative, antioxidant, anti-inflammatory, and antineoplastic activity has been proved. They may act as antioxidants, while preventing DNA damage by scavenging reactive oxygen radicals, reinforcing DNA repair, disrupting chemical damages by induction of phase II enzymes, and modifying signal transduction pathways. One of such research areas is a potential effect of flavonoids on the risk of developing cancer. The aim of our paper is to present a systematic review of antineoplastic activity of flavonols in general. Special attention was paid to selected flavonols: fisetin, kaempferol, and quercetin in preclinical and in vitro studies. Study results prove antiproliferative and proapoptotic properties of flavonols with regard to head and neck cancer. However, few study papers evaluate specific activities during various processes associated with cancer progression. Moreover, an attempt was made to collect the majority of substantive studies on bioactive potential of the selected flavonols, especially with regard to modulation of a range of signal transduction pathways that participate in cancer development.
Effects of a Rice-Based Diet in Korean Adolescents Who Habitually Skip Breakfast: A Randomized, Parallel Group Clinical Trial
Authors: Kim Hyun-Suk , Jung Su-Jin , Mun Eun-Gyung , Kim Myung-Sunny , Cho Soo-Muk , Cha Youn-Soo
Published: March 2021

During adolescence, healthy eating habits are important, and regular meal intake has an especially positive effect on future health. However, the rate of skipping breakfast has gradually increased. Therefore, this study was conducted to evaluate the positive effects of a rice-based breakfast in Korean adolescents who usually skip breakfast. In this open parallel-group, randomized controlled trial, 105 middle and high school students aged 12–18 years who habitually skipped breakfast were recruited. They were randomly divided into three groups: the rice meal group (RMG, n = 35), wheat meal group (WMG, n = 35), and general meal group (GMG, n = 35). The RMG and WMG received a rice-based breakfast and wheat-based breakfast, respectively, for 12 weeks. After a 12-week intervention, the body fat mass (p < 0.05) and body mass index (p < 0.05) in the RMG were significantly lower than those in the other two groups, and the stress score was also significantly lower in the RMG (p < 0.05). Moreover, after the intervention, in the RMG only, compared to baseline levels, the relative theta (RT) wave activity significantly decreased in eight electrode sites, and the relative alpha (RA) wave activity increased significantly. Eating a rice-based breakfast has positive effects on body fat accumulation and cognitive function in Korean adolescents. Furthermore, a rice-based breakfast plan that is preferred by adolescents should be developed to assist them in developing healthy eating habits.
High-Resolution Spatiotemporal Water Use Mapping of Surface and Direct-Root-Zone Drip-Irrigated Grapevines Using UAS-Based Thermal and Multispectral Remote Sensing
Authors: Chandel Abhilash K. , Khot Lav R. , Molaei Behnaz , Peters R. Troy , Stöckle Claudio O. , Jacoby Pete W.
Published: March 2021

Site-specific irrigation management for perennial crops such as grape requires water use assessments at high spatiotemporal resolution. In this study, small unmanned-aerial-system (UAS)-based imaging was used with a modified mapping evapotranspiration at high resolution with internalized calibration (METRIC) energy balance model to map water use (UASM-ET approach) of a commercial, surface, and direct-root-zone (DRZ) drip-irrigated vineyard. Four irrigation treatments, 100%, 80%, 60%, and 40%, of commercial rate (CR) were also applied, with the CR estimated using soil moisture data and a non-stressed average crop coefficient of 0.5. Fourteen campaigns were conducted in the 2018 and 2019 seasons to collect multispectral (ground sampling distance (GSD): 7 cm/pixel) and thermal imaging (GSD: 13 cm/pixel) data. Six of those campaigns were near Landsat 7/8 satellite overpass of the field site. Weather inputs were obtained from a nearby WSU-AgWeatherNet station (1 km). First, UASM-ET estimates were compared to those derived from soil water balance (SWB) and conventional Landsat-METRIC (LM) approaches. Overall, UASM-ET (2.70 ± 1.03 mm day−1 [mean ± std. dev.]) was higher than SWB-ET (1.80 ± 0.98 mm day−1). However, both estimates had a significant linear correlation (r = 0.64–0.81, p < 0.01). For the days of satellite overpass, UASM-ET was statistically similar to LM-ET, with mean absolute normalized ET departures (ETd,MAN) of 4.30% and a mean r of 0.83 (p < 0.01). The study also extracted spatial canopy transpiration (UASM-T) maps by segmenting the soil background from the UASM-ET, which had strong correlation with the estimates derived by the standard basal crop coefficient approach (Td,MAN = 14%, r = 0.95, p < 0.01). The UASM-T maps were then used to quantify water use differences in the DRZ-irrigated grapevines. Canopy transpiration (T) was statistically significant among the irrigation treatments and was highest for grapevines irrigated at 100% or 80% of the CR, followed by 60% and 40% of the CR (p < 0.01). Reference T fraction (TrF) curves established from the UASM-T maps showed a notable effect of irrigation treatment rates. The total water use of grapevines estimated using interpolated TrF curves was highest for treatments of 100% (425 and 320 mm for the 2018 and 2019 seasons, respectively), followed by 80% (420 and 317 mm), 60% (391 and 318 mm), and 40% (370 and 304 mm) of the CR. Such estimates were within 5% to 11% of the SWB-based water use calculations. The UASM-T-estimated water use was not the same as the actual amount of water applied in the two seasons, probably because DRZ-irrigated vines might have developed deeper or lateral roots to fulfill water requirements outside the irrigated soil volume. Overall, results highlight the usefulness of high-resolution imagery toward site-specific water use management of grapevines.
Next Generation Agricultural Stress Index System (ASIS) for Agricultural Drought Monitoring
Authors: Rojas Oscar
Published: March 2021

Over the past 40 years, drought has affected more people in the world than any other natural hazard, affecting large segments of the population and destroying the natural resource base, livestock and livelihoods. Recent projections show that drought events are expected to increase in frequency and intensity due to climate change. According to studies conducted by the Food and Agriculture Organization of the United Nations (FAO), 83% of all damages and losses caused globally by drought between 2006 and 2016 have been absorbed by agriculture, putting a large part of the world’s population at risk of food insecurity. This study shows the advantage of scaling-up FAO’s agricultural drought monitoring and early warning system (ASIS) and building the bridge with the anticipatory action, drought financial mechanisms, social protection and other initiatives for preventing the deterioration of food security and strengthening resilience. The results of the methodology that is based on and supported by the digital innovation, machine learning, matured knowledge and experiences accumulated over the past 10 years are illustrated with practical examples from different countries, ecological environments and crops. A fused time series of Advanced Very-High-Resolution Radiometer (AVHRR) data from Meteorological Operational satellite (METOP) and National Oceanic and Atmospheric Administration (NOAA) was used to produce a consistent time series of a vegetation health index (VHI) at 1 km spatial resolution from 1984 to present. VHI is multiplied by the crop coefficient (kc) to provide more responsiveness to the VHI anomaly that occurs during sensitive phenological phases to water stress such as a flowering and grain filling. The weighted VHI (wVHI) is integrated from the start of the season (SOS) up to the end of season (EOS). Once the temporal analysis of wVHI is completed, the spatial average is calculated using the values of pixels within a specific crop mask and administrative unit. The system proposed different vegetation indices to assess the impact of drought in agriculture; including an agricultural drought forecast that provide more time to the decision makers for implementing anticipatory actions to mitigate the drought in agriculture. Next generation agricultural stress index system (ASIS) offers full capabilities to support: parametric crop insurance, social protection schemes, early action, national drought management plans and to guide public investments.
Complex Analysis of the Efficiency of Difference Reflectance Indices on the Basis of 400–700 nm Wavelengths for Revealing the Influences of Water Shortage and Heating on Plant Seedlings
Authors: Sukhova Ekaterina , Yudina Lyubov , Gromova Ekaterina , Ryabkova Anastasiia , Kior Dmitry , Sukhov Vladimir
Published: March 2021

A drought, which can be often accompanied by increased temperature, is a key adverse factor for agricultural plants. Remote sensing of early plant changes under water shortage is a prospective way to improve plant cultivation; in particular, the sensing can be based on measurement of difference reflectance indices (RIs). We complexly analyzed the efficiency of RIs based on 400–700 nm wavelengths for revealing the influences of water shortage and short-term heating on plant seedlings. We measured spectra of reflected light in leaves of pea, wheat, and pumpkin under control and stress conditions. All possible RIs in the 400–700 nm range were calculated, significances of differences between experimental and control indices were estimated, and heatmaps of the significances were constructed. It was shown that the water shortage (pea seedlings) changed absolute values of large quantity of calculated RIs. Absolute values of some RIs were significantly changed for 1–5 or 2–5 days of the water shortage; they were strongly correlated to the potential quantum yield of photosystem II and relative water content in leaves. In contrast, the short-term heating (pea, wheat, and pumpkin seedlings) mainly influenced light-induced changes in RIs. Our results show new RIs, which are potentially sensitive to the action of stressors.
Field Information Modeling (FIM)™: Best Practices Using Point Clouds
Authors: Maalek Reza
Published: March 2021

This study presented established methods, along with new algorithmic developments, to automate point cloud processing in support of the Field Information Modeling (FIM)™ framework. More specifically, given a multi-dimensional (n-D) designed information model, and the point cloud’s spatial uncertainty, the problem of automatic assignment of point clouds to their corresponding model elements was considered. The methods addressed two classes of field conditions, namely (i) negligible construction errors and (ii) the existence of construction errors. Emphasis was given to defining the assumptions, potentials, and limitations of each method in practical settings. Considering the shortcomings of current frameworks, three generic algorithms were designed to address the point-cloud-to-model assignment. The algorithms include new developments for (i) point cloud vs. model comparison (negligible construction errors), (ii) robust point neighborhood definition, and (iii) Monte-Carlo-based point-cloud-to-model surface hypothesis testing (existence of construction errors). The effectiveness of the new methods was demonstrated in real-world point clouds, acquired from construction projects, with promising results. For the overall problem of point-cloud-to-model assignment, the proposed point cloud vs. model and point-cloud-to-model hypothesis testing methods achieved F-measures of 99.3% and 98.4%, respectively, on real-world datasets.
Robust and Efficient Trajectory Replanning Based on Guiding Path for Quadrotor Fast Autonomous Flight
Authors: Zhao Yinghao , Yan Li , Chen Yu , Dai Jicheng , Liu Yuxuan
Published: March 2021

Path planning is one of the key parts of unmanned aerial vehicle (UAV) fast autonomous flight in an unknown cluttered environment. However, real-time and stability remain a significant challenge in the field of path planning. To improve the robustness and efficiency of the path planning method in complex environments, this paper presents RETRBG, a robust and efficient trajectory replanning method based on the guiding path. Firstly, a safe guiding path is generated by using an improved A* and path pruning method, which is used to perceive the narrow space in its surrounding environment. Secondly, under the guidance of the path, a guided kinodynamic path searching method (GKPS) is devised to generate a safe, kinodynamically feasible and minimum-time initial path. Finally, an adaptive optimization function with two modes is proposed to improve the optimization quality in complex environments, which selects the optimization mode to optimize the smoothness and safety of the path according to the perception results of the guiding path. The experimental results demonstrate that the proposed method achieved good performance both in different obstacle densities and different resolutions. Compared with the other state-of-the-art methods, the quality and success rate of the planning result are significantly improved.
On the Generalization Ability of a Global Model for Rapid Building Mapping from Heterogeneous Satellite Images of Multiple Natural Disaster Scenarios
Authors: Hu Yijiang , Tang Hong
Published: March 2021

Post-classification comparison using pre- and post-event remote-sensing images is a common way to quickly assess the impacts of a natural disaster on buildings. Both the effectiveness and efficiency of post-classification comparison heavily depend on the classifier’s precision and generalization abilities. In practice, practitioners used to train a novel image classifier for an unexpected disaster from scratch in order to evaluate building damage. Recently, it has become feasible to train a deep learning model to recognize buildings from very high-resolution images from all over the world. In this paper, we first evaluate the generalization ability of a global model trained on aerial images using post-disaster satellite images. Then, we systemically analyse three kinds of method to promote its generalization ability for post-disaster satellite images, i.e., fine-tune the model using very few training samples randomly selected from each disaster, transfer the style of postdisaster satellite images using the CycleGAN, and perform feature transformation using domain adversarial training. The xBD satellite images used in our experiment consist of 14 different events from six kinds of frequently occurring disaster types around the world, i.e., hurricanes, tornadoes, earthquakes, tsunamis, floods and wildfires. The experimental results show that the three methods can significantly promote the accuracy of the global model in terms of building mapping, and it is promising to conduct post-classification comparison using an existing global model coupled with an advanced transfer-learning method to quickly extract the damage information of buildings.
Comparison of the Hydrological Dynamics of Poyang Lake in the Wet and Dry Seasons
Authors: Sun Fangdi , Ma Ronghua , Liu Caixia , He Bin
Published: March 2021

Poyang Lake is the largest freshwater lake connecting the Yangtze River in China. It undergoes dramatic dynamics from the wet to the dry seasons. A comparison of the hydrological changes between the wet and dry seasons may be useful for understanding the water flows between Poyang Lake and Yangtze River or the river system in the watershed. Gauged measurements and remote sensing datasets were combined to reveal lake area, level and volume changes during 2000–2020, and water exchanges between Poyang Lake and Yangtze River were presented based on the water balance equation. The results showed that in the wet seasons, the lake was usually around 1301.85–3840.24 km2, with an average value of 2800.79 km2. In the dry seasons, the area was around 618.82–2498.70 km2, with an average value of 1242.03 km2. The inundations in the wet seasons were approximately quadruple those in the dry seasons. In summer months, the lake surface tended to be flat, while in winter months, it was inclined, with the angles at around 10′′–16′′. The mean water levels of the wet and dry seasons were separately 13.51 m and 9.06 m, with respective deviations of around 0–2.38 m and 0.38–2.15 m. Monthly lake volume changes were about 7.5–22.64 km3 and 1–5.80 km3 in the wet and dry seasons, respectively. In the wet seasons, the overall contributions of ground runoff, precipitation on the lake surface and lake evaporation were less than the volume flowing into Yangtze River. In the dry seasons, the three contributions decreased by 50%, 50% and 65.75%, respectively. Therefore, lake storages presented a decrease (−7.42 km3/yr) in the wet seasons and an increase (9.39 km3/yr) in the dry seasons. The monthly exchanges between Poyang Lake and Yangtze River were at around −14.22–32.86 km3. Water all flowed from the lake to the river in the wet seasons, and the chance of water flowing from Yangtze River in the dry seasons was only 5.26%.
Benchmarking Deep Learning Models for Cloud Detection in Landsat-8 and Sentinel-2 Images
Authors: López-Puigdollers Dan , Mateo-García Gonzalo , Gómez-Chova Luis
Published: March 2021

The systematic monitoring of the Earth using optical satellites is limited by the presence of clouds. Accurately detecting these clouds is necessary to exploit satellite image archives in remote sensing applications. Despite many developments, cloud detection remains an unsolved problem with room for improvement, especially over bright surfaces and thin clouds. Recently, advances in cloud masking using deep learning have shown significant boosts in cloud detection accuracy. However, these works are validated in heterogeneous manners, and the comparison with operational threshold-based schemes is not consistent among many of them. In this work, we systematically compare deep learning models trained on Landsat-8 images on different Landsat-8 and Sentinel-2 publicly available datasets. Overall, we show that deep learning models exhibit a high detection accuracy when trained and tested on independent images from the same Landsat-8 dataset (intra-dataset validation), outperforming operational algorithms. However, the performance of deep learning models is similar to operational threshold-based ones when they are tested on different datasets of Landsat-8 images (inter-dataset validation) or datasets from a different sensor with similar radiometric characteristics such as Sentinel-2 (cross-sensor validation). The results suggest that (i) the development of cloud detection methods for new satellites can be based on deep learning models trained on data from similar sensors and (ii) there is a strong dependence of deep learning models on the dataset used for training and testing, which highlights the necessity of standardized datasets and procedures for benchmarking cloud detection models in the future.
From GPS Receiver to GNSS Reflectometry Payload Development for the Triton Satellite Mission
Authors: Tsai Yung-Fu , Yeh Wen-Hao , Juang Jyh-Ching , Yang Dian-Syuan , Lin Chen-Tsung
Published: March 2021

The global positioning system (GPS) receiver has been one of the most important navigation systems for more than two decades. Although the GPS system was originally designed for near-Earth navigation, currently it is widely used in highly dynamic environments (such as low Earth orbit (LEO)). A space-capable GPS receiver (GPSR) is capable of providing timing and navigation information for spacecraft to determine the orbit and synchronize the onboard timing; therefore, it is one of the essential components of modern spacecraft. However, a space-grade GPSR is technology-sensitive and under export control. In order to overcome export control, the National Space Organization (NSPO) in Taiwan completed the development of a self-reliant space-grade GPSR in 2014. The NSPO GPSR, built in-house, has passed its qualification tests and is ready to fly onboard the Triton satellite. In addition to providing navigation, the GPS/global navigation satellite system (GNSS) is facilitated to many remote sensing missions, such as GNSS radio occultation (GNSS-RO) and GNSS reflectometry (GNSS-R). Based on the design of the NSPO GPSR, the NSPO is actively engaged in the development of the Triton program (a GNSS reflectometry mission). In a GNSS-R mission, the reflected signals are processed to form delay Doppler maps (DDMs) so that various properties (including ocean surface roughness, vegetation, soil moisture, and so on) can be retrieved. This paper describes not only the development of the NSPO GPSR but also the design, development, and special features of the Triton’s GNSS-R mission. Moreover, in order to verify the NSPO GNSS-R receiver, ground/flight tests are deemed essential. Then, data analyses of the airborne GNSS-R tests are presented in this paper.
HARP: Hierarchical Attention Oriented Region-Based Processing for High-Performance Computation in Vision Sensor
Authors: Bhowmik Pankaj , Pantho Md Jubaer Hossain , Bobda Christophe
Published: March 2021

Cameras are widely adopted for high image quality with the rapid advancement of complementary metal-oxide-semiconductor (CMOS) image sensors while offloading vision applications’ computation to the cloud. It raises concern for time-critical applications such as autonomous driving, surveillance, and defense systems since moving pixels from the sensor’s focal plane are expensive. This paper presents a hardware architecture for smart cameras that understands the salient regions from an image frame and then performs high-level inference computation for sensor-level information creation instead of transporting raw pixels. A visual attention-oriented computational strategy helps to filter a significant amount of redundant spatiotemporal data collected at the focal plane. A computationally expensive learning model is then applied to the interesting regions of the image. The hierarchical processing in the pixels’ data path demonstrates a bottom-up architecture with massive parallelism and gives high throughput by exploiting the large bandwidth available at the image source. We prototype the model in field-programmable gate array (FPGA) and application-specific integrated circuit (ASIC) for integrating with a pixel-parallel image sensor. The experiment results show that our approach achieves significant speedup while in certain conditions exhibits up to 45% more energy efficiency with the attention-oriented processing. Although there is an area overhead for inheriting attention-oriented processing, the achieved performance based on energy consumption, latency, and memory utilization overcomes that limitation.
Energy Minimization Algorithm for Estimation of Clock Skew and Reception Window Selection in Wireless Networks
Authors: Gorawski Michał , Grochla Krzysztof , Marjasz Rafał , Frankiewicz Artur
Published: March 2021

The synchronization of time between devices is one of the more important and challenging problems in wireless networks. We discuss the problem of maximization of the probability of receiving a message from a device using a limited listening time window to minimize energy utilization. We propose a solution to two important problems in wireless networks of battery-powered devices: a method of establishing a connection with a device that has been disconnected from the system for a long time and developed unknown skew and also two approaches to follow-up clock synchronization using the confidence interval method. We start with the analysis of measurements of clock skew. The algorithms are evaluated using extensive simulations and we discuss the selection of parameters balancing between minimizing the energy utilization and maximizing the probability of reception of the message. We show that the selection of a time window of growing size requires less energy to receive a packet than using the same size of time window repeated multiple times. The shifting of reception windows can further decrease the energy cost if lower packet reception probability is acceptable. We also propose and evaluate an algorithm scaling the reception window size to the interval between the packet transmission.
Inspection Method of Rope Arrangement in the Ultra-Deep Mine Hoist Based on Optical Projection and Machine Vision
Authors: Shi Lixiang , Tan Jianping , Xue Shaohua , Deng Jiwei
Published: March 2021

Due to the importance of safety detection of the drum’s rope arrangement in the ultra-deep mine hoist and the current situation whereby the speed, accuracy and robustness of rope routing detection are not up to the requirements, a novel machine-vision-detection method based on the projection of the drum’s edge is designed in this paper. (1) The appropriate position of the point source corresponding to different reels is standardized to obtain better projection images. (2) The corresponding image processing and edge curve detection algorithm are designed according to the characteristics of rope arrangement projection. (3) The Gaussian filtering algorithm is improved to adapt to the situation that the curve contains wavelet peak noise when extracting the eigenvalues of the edge curve. (4) The DBSCAN (density-based spatial clustering of applications with noise) method is used to solve the unsupervised classification problem of eigenvalues of rope arrangement, and the distance threshold is calculated according to the characteristics of this kind of data. Finally, we can judge whether there is a rope arranging fault just through one frame and output the location and number of the fault. The accuracy and robustness of the method are verified both in the laboratory and the ultra-deep mine simulation experimental platform. In addition, the detection speed can reach 300 fps under the premise of stable detection.
The Design and Manufacturing Process of an Electrolyte-Free Liquid Metal Frequency-Reconfigurable Antenna
Authors: Qin Peng , Wang Lei , Liu Tian-Ying , Wang Qian-Yu , Fu Jun-Heng , Huang Guan-Long , Gui Lin , Liu Jing , Deng Zhong-Shan
Published: March 2021

This communication provides an integrated process route of smelting gallium-based liquid metal (GBLM) in a high vacuum, and injecting GBLM into the antenna channel in high-pressure protective gas, which avoids the oxidation of GBLM during smelting and filling. Then, a frequency-reconfigurable antenna, utilizing the thermal expansion characteristic of GBLM, is proposed. To drive GBLM into an air-proof space, the thermal expansion characteristics of GBLM are required. The dimensions of the radiating element of the liquid metal antenna can be adjusted at different temperatures, resulting in the reconfigurability of the operating frequency. To validate the proposed concept, an L-band antenna prototype was fabricated and measured. Experimental results demonstrate that the GBLM in the antenna was well filled, and the GBLM was not oxidized. Due to the GBLM being in an air-proof channel, the designed liquid metal antenna without electrolytes could be used in an air environment for a long time. The antenna is able to achieve an effective bandwidth of over 1.25–2.00 GHz between 25 °C and 100 °C. The maximum radiation efficiency and gain in the tunable range are 94% and 2.9 dBi, respectively. The designed antenna also provides a new approach to the fabrication of a temperature sensor that detects temperature in some situations that are challenging for conventional temperature sensing technology.
Towards Robust Robot Control in Cartesian Space Using an Infrastructureless Head- and Eye-Gaze Interface
Authors: Wöhle Lukas , Gebhard Marion
Published: March 2021

This paper presents a lightweight, infrastructureless head-worn interface for robust and real-time robot control in Cartesian space using head- and eye-gaze. The interface comes at a total weight of just 162 g. It combines a state-of-the-art visual simultaneous localization and mapping algorithm (ORB-SLAM 2) for RGB-D cameras with a Magnetic Angular rate Gravity (MARG)-sensor filter. The data fusion process is designed to dynamically switch between magnetic, inertial and visual heading sources to enable robust orientation estimation under various disturbances, e.g., magnetic disturbances or degraded visual sensor data. The interface furthermore delivers accurate eye- and head-gaze vectors to enable precise robot end effector (EFF) positioning and employs a head motion mapping technique to effectively control the robots end effector orientation. An experimental proof of concept demonstrates that the proposed interface and its data fusion process generate reliable and robust pose estimation. The three-dimensional head- and eye-gaze position estimation pipeline delivers a mean Euclidean error of 19.0±15.7 mm for head-gaze and 27.4±21.8 mm for eye-gaze at a distance of 0.3–1.1 m to the user. This indicates that the proposed interface offers a precise control mechanism for hands-free and full six degree of freedom (DoF) robot teleoperation in Cartesian space by head- or eye-gaze and head motion.
Development of a Low-Cost, Modular Muscle–Computer Interface for At-Home Telerehabilitation for Chronic Stroke
Authors: Marin-Pardo Octavio , Phanord Coralie , Donnelly Miranda Rennie , Laine Christopher M. , Liew Sook-Lei
Published: March 2021

Stroke is a leading cause of long-term disability in the United States. Recent studies have shown that high doses of repeated task-specific practice can be effective at improving upper-limb function at the chronic stage. Providing at-home telerehabilitation services with therapist supervision may allow higher dose interventions targeted to this population. Additionally, muscle biofeedback to train patients to avoid unwanted simultaneous activation of antagonist muscles (co-contractions) may be incorporated into telerehabilitation technologies to improve motor control. Here, we present the development and feasibility of a low-cost, portable, telerehabilitation biofeedback system called Tele-REINVENT. We describe our modular electromyography acquisition, processing, and feedback algorithms to train differentiated muscle control during at-home therapist-guided sessions. Additionally, we evaluated the performance of low-cost sensors for our training task with two healthy individuals. Finally, we present the results of a case study with a stroke survivor who used the system for 40 sessions over 10 weeks of training. In line with our previous research, our results suggest that using low-cost sensors provides similar results to those using research-grade sensors for low forces during an isometric task. Our preliminary case study data with one patient with stroke also suggest that our system is feasible, safe, and enjoyable to use during 10 weeks of biofeedback training, and that improvements in differentiated muscle activity during volitional movement attempt may be induced during a 10-week period. Our data provide support for using low-cost technology for individuated muscle training to reduce unintended coactivation during supervised and unsupervised home-based telerehabilitation for clinical populations, and suggest this approach is safe and feasible. Future work with larger study populations may expand on the development of meaningful and personalized chronic stroke rehabilitation.
Acoustical Slot Mode Sensor for the Rapid Coronaviruses Detection
Authors: Guliy Olga , Zaitsev Boris , Teplykh Andrey , Balashov Sergey , Fomin Alexander , Staroverov Sergey , Borodina Irina
Published: March 2021

A method for the rapid detection of coronaviruses is presented on the example of the transmissible gastroenteritis virus (TGEV) directly in aqueous solutions with different conductivity. An acoustic sensor based on a slot wave in an acoustic delay line was used for the research. The addition of anti-TGEV antibodies (Abs) diluted in an aqueous solution led to a change in the depth and frequency of resonant peaks on the frequency dependence of the insertion loss of the sensor. The difference in the output parameters of the sensor before and after the biological interaction of the TGE virus in solutions with the specific antibodies allows drawing a conclusion about the presence/absence of the studied viruses in the analyzed solution. The possibility for virus detection in aqueous solutions with the conductivity of 1.9–900 μs/cm, as well as in the presence of the foreign viral particles, has been demonstrated. The analysis time did not exceed 10 min.
Development of Broadband High-Frequency Piezoelectric Micromachined Ultrasonic Transducer Array
Authors: Wang Xu-Bo , He Le-Ming , Ma You-Cao , Liu Wen-Juan , Xu Wei-Jiang , Ren Jun-Yan , Riaud Antoine , Zhou Jia
Published: March 2021

Piezoelectric micromachined ultrasonic transducers (PMUT) are promising elements to fabricate a two-dimensional (2D) array with a pitch small enough (approximately half wavelength) to form and receive arbitrary acoustic beams for medical imaging. However, PMUT arrays have so far failed to combine the wide, high-frequency bandwidth needed to achieve a high axial resolution. In this paper, a polydimethylsiloxane (PDMS) backing structure is introduced into the PMUTs to improve the device bandwidth while keeping a sub-wavelength (λ) pitch. We implement this backing on a 16 × 8 array with 75 µm pitch (3λ/4) with a 15 MHz working frequency. Adding the backing nearly doubles the bandwidth to 92% (−6 dB) and has little influence on the impulse response sensitivity. By widening the transducer bandwidth, this backing may enable using PMUT ultrasonic arrays for high-resolution 3D imaging.
TiO2 Nanorods and Pt Nanoparticles under a UV-LED for an NO2 Gas Sensor at Room Temperature
Authors: Noh Jinhong , Kwon Soon-Hwan , Park Sunghoon , Kim Kyoung-Kook , Yoon Yong-Jin
Published: March 2021

Because the oxides of nitrogen (NOx) cause detrimental effects on not only the environment but humans, developing a high-performance NO2 gas sensor is a crucial issue for real-time monitoring. To this end, metal oxide semiconductors have been employed for sensor materials. Because in general, semiconductor-type gas sensors require a high working temperature, photoactivation has emerged as an alternative method for realizing the sensor working at room temperature. In this regard, titanium dioxide (TiO2) is a promising material for its photocatalytic ability with ultraviolet (UV) photonic energy. However, TiO2-based sensors inevitably encounter a problem of recombination of photogenerated electron-hole pairs, which occurs in a short time. To address this challenge, in this study, TiO2 nanorods (NRs) and Pt nanoparticles (NPs) under a UV-LED were used as an NO2 gas sensor to utilize the Schottky barrier formed at the TiO2-Pt junction, thereby capturing the photoactivated electrons by Pt NPs. The separation between the electron-hole pairs might be further enhanced by plasmonic effects. In addition, it is reported that annealing TiO2 NRs can achieve noteworthy improvements in sensing performance. Elucidation of the performance enhancement is suggested with the investigation of the X-ray diffraction patterns, which implies that the crystallinity was improved by the annealing process.
Association of Antibiotic Use with the Resistance Epidemiology of Pseudomonas aeruginosa in a Hospital Setting: A Four-Year Retrospective Time Series Analysis
Authors: Kousovista Rania , Athanasiou Christos , Liaskonis Konstantinos , Ivopoulou Olga , Karalis Vangelis
Published: March 2021

Background: Even though, Pseudomonas aeruginosa is a common cause of hospital-acquired infections, treatment is challenging because of decreasing rates of susceptibility to many broad-spectrum antibiotics. Methods: Consumption data of eight broad spectrum antimicrobial agents and resistance rates of P. aeruginosa were collected for 48 consecutive months. Autoregressive integrated moving average (ARIMA) and transfer functions models were used to develop relationships between antibiotic use and resistance. Results: Positive correlations between P. aeruginosa resistance and uses of ciprofloxacin (p < 0.001), meropenem (p < 0.001), and cefepime (p = 0.005) were identified. Transfer function models showed the quantified effect of each of these antibiotics on resistance. Regarding levofloxacin, ceftazidime, piperacillin/tazobactam and imipenem, no significant relationships were found. For ceftazidime and levofloxacin, this was probably due to their low consumption, while for imipenem the reason can possibly be ascribed to the already high established P. aeruginosa resistance in the hospital. Conclusion: In the hospital setting, the effect of antimicrobial agents’ consumption on the susceptibility epidemiology of P. aeruginosa differs significantly for each one of them. In this study, the role of precedent use of meropenem, cefepime and ciprofloxacin was quantified in the development of P. aeruginosa resistance.
Sustainable Strategies for Marathon Tourism in the Time of Pandemics
Authors: Chen Kuo-Hsiung , Yien Jui-Mei , Kao Chien-Chung , Chen Ying-Yu , Tsai Fu-Sheng
Published: March 2021

This study established a new assessment framework to explore the mutual influences of the international marathon tourism indices. A hybrid multiple-criteria decision-making model was used to determine solutions. The surveyed expert team revealed that satisfaction with the Kaohsiung International marathon indices requires improvement, especially in the age of pandemic crisis. To make marathon tourism sustainable, we propose the following systematic improvement procedures: Decision-makers should improve the manager’s professional capabilities and ability to use a comprehensive thinking model to solve problems. Next, managers should invite tourism practitioners from neighboring areas to provide more diverse food and performances along the marathon route. Citizens should be invited to join the cheerleaders to create a lively atmosphere. In addition to the full marathon and half marathon, a completion certificate and a better gift should be provided to participants of races of other distances to increase their sense of self-worth and to encourage more runners to participate, thereby ensuring a more robust crowd of runners at the starting line.
Cultural Differences in Design-Based Product Evaluation: The Role of Holistic and Analytic Thinking
Authors: Liu Li , Orth Ulrich
Published: March 2021

Product evaluation research has a long tradition of examining how consumers evaluate a product from the product itself in an attempt to understand why certain products are better perceived or worse perceived. Usually consumers recall the memory of high evaluation products in their minds when they make buying decisions. Better fitting perceptions would be more favorable than poor fitting ones. Our findings indicate that culture is an important reason that influences consumers’ responses to design-based product evaluations. Westerners evaluate products differently than Easterners due to cross-cultural differences in styles of thinking. Two cultures of people have differences in design-based product evaluation. In most cases, Easterners have more favorable evaluations of a new packaging product than Westerners.
Evaluation of Provincial Carbon Neutrality Capacity of China Based on Combined Weight and Improved TOPSIS Model
Authors: Niu Dongxiao , Wu Gengqi , Ji Zhengsen , Wang Dongyu , Li Yuying , Gao Tian
Published: March 2021

It will be a huge challenge for China to achieve carbon neutrality by 2060. At present, China needs to understand its own carbon neutrality status and then scientifically plan a path to achieve carbon neutrality. In order to evaluate the carbon neutrality capacity of China’s provinces, this paper firstly constructs an evaluation indicator system, which includes 20 indicators at six levels. Then, a combination of subjective and objective weighting methods, as well as an improved technique for order preference by similarity to an ideal solution (TOPSIS) model, are used to calculate evaluation results. On this basis, the reasons for their different carbon neutrality capacities are analyzed. The results show that the use of renewable energy, maintaining ecological environmental quality, and low-carbon technology are important factors affecting China’s carbon neutrality capacity, and according to the evaluation results, China’s provinces are divided into three categories. Finally, corresponding suggestions for speeding up the pace of carbon neutrality are put forward.
The Incidence of Social Responsibility in the Adoption of Business Practices
Authors: Arenas-Torres Felipe , Bustamante-Ubilla Miguel , Campos-Troncoso Roberto
Published: March 2021

Corporate social responsibility (CSR) policies are evidenced by adopting socially relevant business practices for people, communities, companies, and related institutions. Based on this conception, the present work determines the incidence of ethics and CSR on practices regarding diversity, environment, and community of Chilean companies. The method, applied to a sample of 3179 Chilean companies, was descriptive and correlational. Results demonstrate an incipient level of standardization in the adoption of social responsibility practices. The dimension regarding diversity presented a higher cumulative correlation coefficient, which could lead to a change in CSR practices. It is concluded that the collective impact of the ethics and CSR policies was positive and significant in the adoption of practices related to diversity, environment, and community.
The Effect of Organizational Information Security Climate on Information Security Policy Compliance: The Mediating Effect of Social Bonding towards Healthcare Nurses
Authors: Dong Ke , Ali Rao Faizan , Dominic P. D. D. , Ali Syed Emad Azhar
Published: March 2021

The advancement of information communication technology in healthcare institutions has increased information security breaches. Scholars and industry practitioners have reported that most security breaches are due to negligence towards organizational information security policy compliance (ISPC) by healthcare employees such as nurses. There is, however, a lack of understanding of the factors that ensure ISPC among nurses, especially in developing countries such as Malaysia. This paper develops and examines a research framework that draws upon the factors of organizational climate of information security (OCIS) and social bond theory to enhance ISPC among nurses. A questionnaire was adopted in which responses were obtained from 241 nurses employed in 30 hospitals in Malaysia. The findings from the study demonstrated that the ISPC among nurses is enhanced through OCIS factors. The influence on ISPC was even more significant when examined by the mediating effect of the social bond. It implies that influential OCIS factors reinforce social bonds among nurses and eventually increase the ISPC. For information security practitioners, the study findings emphasize the prevalence of socio-active information security culture in healthcare organizations to enhance ISP compliance among nurses.
Sustainability-Oriented Project Scheduling Based on Z-Fuzzy Numbers for Public Institutions
Authors: Kuchta Dorota , Marchwicka Ewa , Schneider Jan
Published: March 2021

A new approach to sustainable project scheduling for public institutions is proposed. The approach is based on experts’ opinions on three aspects of sustainability of project activities (human resources consumption, material consumption and negative influence on local communities), expressed by means of Z-fuzzy numbers. A fuzzy bicriterial optimization model is proposed, whose objective is to obtain a project schedule of an acceptable sustainability degree and of acceptable duration and cost. The model was inspired and is illustrated by a real-world infrastructure project, implemented in 2019 by a public institution in Poland.