bluuebunny/crossref_metadata_2025 huggingface dataset:
FirepanIF: High Performance Host-Side Flash Cache Warm-Up Method in Cloud Computing
Authors: Park Hyunchan , Lee Munkyu , Hong Cheol-Ho
Published: February 2020

In cloud computing, a shared storage server, which provides a network-attached storage device, is usually used for centralized data management. However, when multiple virtual machines (VMs) concurrently access the storage server through the network, the performance of each VM may decrease due to limited bandwidth. To address this issue, a flash-based storage device such as a solid state drive (SSD) is often employed as a cache in the host server. This host-side flash cache saves remote data, which are frequently accessed by the VM, locally in the cache. However, frequent VM migration in the data center can weaken the effectiveness of a host-side flash cache as the migrated VM needs to warm up its flash cache again on the destination machine. This study proposes Cachemior, Firepan, and FirepanIF for rapid flash-cache migration in cloud computing. Cachemior warms up the flash cache with a data preloading approach using the shared storage server after VM migration. However, it does not achieve a satisfactory level of performance. Firepan and FirepanIF use the source node’s flash cache as the data source for flash cache warm-up. They can migrate the flash-cache more quickly than conventional methods as they can avoid storage and network congestion on the shared storage server. Firepan incurs downtime of the VM during flash cache migration for data consistency. FirepanIF minimizes the VM downtime with the invalidation filter, which traces the I/O activity of the migrated VM during flash cache migration in order to invalidate inconsistent cache blocks. We implement and evaluate the three flash cache migration techniques in a realistic virtualized environment. FirepanIF demonstrates that it can improve the performance of the I/O workload by up to 21.87% compared to conventional methods.
A Review of Orbital Angular Momentum Vortex Beams Generation: From Traditional Methods to Metasurfaces
Authors: Zhang Kuang , Wang Yuxiang , Yuan Yueyi , Burokur Shah Nawaz
Published: February 2020

In this paper, we review the generation of vortex beams carrying orbital angular momentum in the microwave domain. We firstly present the theory of Laguerre–Gaussian beams where it is demonstrated that they carry such type of momentum. We further provide an overview of the classical methods used to generate orbital angular momentum vortex beams, which rely on two main methods; plane wave to vortex wave conversion and direct generation using radiating antennas. Then, we present recent progress in the physics of metasurfaces devoted to the generation of vortex beams with a discussion about reflective and transmissive metasurfaces for plane wave to vortex wave conversion as well as methods to reduce the intrinsic divergence characteristics of vortex beams. Finally, we conclude on this rapidly developing research field.
Temporal Saliency-Based Suspicious Behavior Pattern Detection
Authors: Cheoi Kyung Joo
Published: February 2020

The topic of suspicious behavior detection has been one of the most emergent research themes in computer vision, video analysis, and monitoring. Due to the huge number of CCTV (closed-circuit television) systems, it is not easy for people to manually identify CCTV for suspicious motion monitoring. This paper is concerned with an automatic suspicious behavior detection method using a CCTV video stream. Observers generally focus their attention on behaviors that vary in terms of magnitude or gradient of motion and behave differently in rules of motion with other objects. Based on these facts, the proposed method detected suspicious behavior with a temporal saliency map by combining the moving reactivity features of motion magnitude and gradient extracted by optical flow. It has been tested on various video clips that contain suspicious behavior. The experimental results show that the performance of the proposed method is good at detecting the six designated types of suspicious behavior examined: sudden running, colliding, falling, jumping, fighting, and slipping. The proposed method achieved an average accuracy of 93.89%, a precision of 96.21% and a recall of 94.90%.
Electrochemical Behavior of NH4F-Pretreated Li1.25Ni0.20Fe0.13Co0.33Mn0.33O2 Cathodes for Lithium-ion Batteries
Authors: Zheng Yonglei , Li Yikai , Wang He , Chen Siheng , Guo Xiangxin , Xu Sheng , Cai Zhongyu
Published: February 2020

We report a novel method to fabricate lithium-ion batteries cathodes with the NH4F pretreatment. In this study, NH4F-pretreated Li1.25Ni0.20Fe0.13Co0.33Mn0.33O2 hollow nano-micro hierarchical microspheres were synthesized for use as cathode materials. The X-ray diffraction patterns of NH4F-pretreated Li1.25Ni0.20Co0.33Fe0.13Mn0.33O2 were analyzed with the RIETAN-FP software program, and the results showed that the samples possess a layered α-NaFeO2 structure. The effects of pretreatment with NH4F on the electrochemical performance of the pristine material were evaluated through charge/discharge cycling, the rate performance, and electrochemical impedance spectroscopy (EIS). Pretreatment with NH4F significantly improved the discharge capacities and coulombic efficiencies of Li1.25Ni0.20Co0.33Fe0.13Mn0.33O2 in the first cycle and during subsequent electrochemical cycling. The sample pretreated with an appropriate amount of NH4F (NFCM 90) showed the highest discharge capacity (209.1 mA h g−1) and capacity retention (85.2% for 50 cycles at 0.1 C). The EIS results showed that the resistance of the NFCM 90 sample (76.32 Ω) is lower than that of the pristine one (206.2 Ω).
Dynamic Balance Method for Grading the Chain Drive Double Threshing Drum of a Combine Harvester
Authors: Tang Zhong , Li Xiyao , Liu Xin , Ren Hui , Zhang Biao
Published: February 2020

Although the individual threshing drum of a combine harvester was balanced on a dynamic balancing machine before it is assembled, there were still unbalances after multiple drums were assembled with the chain drive. In this paper, the double drums with a chain drive of a crawler combined harvester were selected as the research subject. The aim of this study was to develop a dynamic unbalance mode for grading chain drive double drums. Based on the dynamic unbalance characteristics of the main driven drum, the experimental research on the radial balance of the driven drum end face was carried out. It was known that the chain drive had a direct and obvious influence on the unbalanced phase of the drum. The unbalance of the drive load had an obvious effect on unbalanced amplitude of an active drum through the transfer characteristics of the chain drive. For the multi-stage transmission characteristics of a combine harvester, a step-by-step balanced grading chain drive double drum dynamic balancing method was practiced. Results showed that the unbalanced amplitude after balancing threshing drum I chain transmission mode of the combine harvester can be reduced by a maximum of 91%. Simultaneously, the unbalanced amplitude of threshing drum II can reduced by a maximum of 69.2%. The size and position of the wrap angle of the chain drive would directly affect the phase of the two equivalent unbalanced masses.
The Influences of Acoustic and Pulsed Corona Discharge Coupling Field on Agglomeration of Monodisperse Fine Particles
Authors: He Mingchun , Luo Zhongyang , Wang Haolin , Fang Mengxiang
Published: February 2020

In view of the low efficiency of traditional electrostatic precipitators in removing fine particles, acoustic and pulsed corona discharge coupling fields were proposed to increase particle size. In this paper, monodisperse particles with three different sizes (0.5 μm, 2 μm, and 4 μm) were generated to investigate the agglomeration effect under different parameters in external fields. A larger reduction ratio of particle number concentration resulted in a higher agglomeration efficiency. Results indicated that, in the range from 800 to 2400 Hz, the acoustic agglomeration effect on 4-μm particles was better than that on 0.5-μm and 2-μm particles. In the pulsed corona discharge field, agglomeration efficiencies of the three particle sizes were lower than those in the acoustic field. However, application of the coupling field highly improved agglomeration efficiency compared with the single field. When a pulse input voltage of 50 kV with acoustic sound pressure level (SPL) of 143 dB and frequency of 1600 Hz was selected, the corresponding number reduction ratio of 0.5-μm, 2-μm, and 4-μm particles increased to 0.464, 0.526, and 0.918 from 0.254, 0.438, and 0.814 in the acoustic wave field and 0.226, 0.385, and 0.794 in the pulsed corona discharge field.
Influence of Arctic Oscillation on Frequency of Wintertime Fog Days in Eastern China
Authors: Liu Peng , Tang Mingyue , Yu Huaying , Zhang Ying
Published: February 2020

The influence of Arctic Oscillation (AO) on the frequency of wintertime fog days in eastern China is studied based on the winter AO index, the wintertime fog-day data of national stations in China, and the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis data from 1954 to 2007. The results show that heavy fog and light fog are more likely to occur during winter in eastern China with the strong interannual variability. During the winter with the positive-phase AO, there are more days of heavy fog in North China but less in South China, while light fog days become more in the whole of eastern China. It is mainly because that when AO is in the positive phase, the pressure in the polar region decreases at 500 hPa; the pressure in East Asia increases anomalously; the East Asian trough decreases; and the low-level westerly jet moves northward, preventing the northwesterly cold air from moving southward. Therefore, the whole eastern China gets warmer and wetter air, and there are more light fog days with the enhanced water vapor. However, the atmosphere merely becomes more towards unstable in South China, where the precipitation increases but the heavy fog days decreases. Nevertheless, heavy fog days increase with the water vapor in North China because of moving towards a stable atmosphere, which is formed by the anomalous downdrafts north of the precipitation center in South China. When AO is in the negative phase, the situation is basically opposite to that in the positive phase, but the variations of the corresponding fog days and circulations are weaker than those in the AO-positive-phase winter, which may be related to the nonlinear effect of AO on climate.
Active Packaging—Poly(Vinyl Alcohol) Films Enriched with Tomato By-Products Extract
Authors: Szabo Katalin , Teleky Bernadette-Emoke , Mitrea Laura , Călinoiu Lavinia-Florina , Martău Gheorghe-Adrian , Simon Elemer , Varvara Rodica-Anita , Vodnar Dan Cristian
Published: February 2020

Active films were prepared from poly(vinyl alcohol) (PVA) blended with itaconic acid (Ia), and with chitosan (Ch), enriched with tomato processing by-products extract (TBE) in order to develop new bioactive formulations for food packaging. The effects of two biopolymers (Ch, Ia) and of the incorporated TBE—containing phenolic compounds and carotenoids—were studied regarding the physical and antimicrobial properties of films; in addition, their influence on the total phenolic content, viscosity, and flow behavior on the film-forming solutions was investigated. The results showed increased physical properties (diameter, thickness, density, weight) of the films containing the TBE versus their control. TBE and Ch conferred significant antimicrobial effects to PVA films toward all the tested microorganisms, whereas the best inhibition was registered against S. aureus and P. aeruginosa, with a minimum inhibitory concentration of <0.078 mg DW/mL. The Ia-PVA films also exhibited some antibacterial activity against P. aeruginosa (2.5 mg DW/mL). The total phenolic content of the film-forming solutions presented the highest values for the TBE and Ch-added PVA samples (0.208 mg gallic acid/100 mL film-forming solution). These results suggest that the PVA + Ch film containing TBE can be used for the development of intelligent and active food packaging materials.
The Business Process Model and Notation Used for the Representation of Alzheimer’s Disease Patients Care Process
Authors: Kopecky Martin , Tomaskova Hana
Published: February 2020

Currently, the number of patients with neurological diseases is increasing, especially those older than 65 suffering from Alzheimer’s disease. This development increases the emphasis on understanding and mapping treatment and care processes, not only for the elderly. Service providers (of both treatment and care) are under general pressure to decrease charges and maintain or improve existing levels of care. This situation is significantly influenced by a comprehensive knowledge of the whole process and its values. This publication therefore aims to describe the fundamental procedural aspects of caring for patients with Alzheimer’s disease, using Business Process Model and Notation (BPMN). It also aims to show the possibilities of using BPMN in the description of treatment and care. Modeling of the business process is more frequently being applied not only by businesses but also by scientists involved in process models. It is used to model medical topics, with approximately 10% of its publications only, and most of these publications deal only with clinical pathways, not with overall treatment and care processes. However, the BPMN model allows the whole process of medical and nonmedical care for patients with Alzheimer’s disease to be described, including the decomposition of partial activities into individual threads and sub-processes or atomic tasks. This paper presents the BPMN modeling and mapping of the specific care path for neurodegenerative patients. The text provides a new perspective on the BPMN modeling of Alzheimer’s disease. The presented model offers the option of expanding treatment cost calculation to simulate the process using graphical tools and languages. The overall view of this system creates a much more complex concept of the system and its surroundings.
Structured Mesh Generation and Numerical Analysis of a Scroll Expander in an Open-Source Environment
Authors: Fadiga Ettore , Casari Nicola , Suman Alessio , Pinelli Michele
Published: February 2020

The spread of the organic rankine cycle applications has driven researchers and companies to focus on the improvement of their performance. In small to medium-sized plants, the expander is the component that has typically attracted the most attention. One of the most used types of machine in this scenario is the scroll. Among the other methods, numerical analyses have been increasingly exploited for the investigation of the machine’s behaviour. Nonetheless, there are major challenges for the successful application of computational fluid dynamics (CFD) to scrolls. Specifically, the dynamic mesh treatment required to capture the movement of working chambers and the nature of the expanding fluids require special care. In this work, a mesh generator for scroll machines is presented. Given few inputs, the software described provides the mesh and the nodal positions required for the evolution of the motion in a predefined mesh motion approach. The mesh generator is developed ad hoc for the coupling with the open-source CFD suite OpenFOAM. A full analysis is then carried out on a reverse-engineered commercial machine, including the refrigerant properties calculations via CoolProp. It is demonstrated that the proposed methodology allows for a fast simulation and achieves a good agreement with respect to former analyses.
Evaluation of Zeolite as a Potential Reactive Medium in a Permeable Reactive Barrier (PRB): Batch and Column Studies
Authors: Rocha Liana Carolina Carvalho , Zuquette Lazaro Valentin
Published: February 2020

The purpose of this work is to evaluate the capacity of a natural zeolite to be used as a reactive material in a permeable reactive barrier (PRB) to remove inorganic contaminants from groundwater. To this aim, zeolite samples were subjected to characterization tests, column experiments, batch tests and a flushing process to evaluate the adsorption and desorption capacities of the zeolite. In the column experiments, the samples were subjected to eight successive cycles involving the percolation of a potassium aqueous solution (1500 mg/L) and a subsequent flushing process with water. Batch tests were conducted by mixing 20 g of zeolite with 100 mL of single-element aqueous solutions of K and Zn with concentrations of 200 mg/L. The results indicate that the zeolite rock is composed predominantly of clinoptilolite species and has a Si/Al ratio of 6.8, a high cationic exchange capacity (CEC) of 180 cmolc/kg and a high K+ adsorption rate with a removal efficiency of 78%. The adsorption isotherms of the zeolite follow the Langmuir model and are well fit by a pseudo-second-order kinetic model showing a high correlation coefficient (r2 > 0.999) for both K+ and Zn2+ cations. Additionally, the contaminant transport parameters for K+ ions (Rd = 24.9; Dh = 1.32 × 10–2 cm2/s and α = 1.42) reveal that the zeolite is resistant to the dispersion of ions in the barrier, indicating that the material has advantageous characteristics for use in a PRB. However, the flushing process of the material is not efficient, indicating that the appropriate use of the zeolite is in clean-up systems in which the adsorbent material can be exchanged after losing its efficiency as a reactive barrier.
Numerical Simulation of Donghu Lake Hydrodynamics and Water Quality Based on Remote Sensing and MIKE 21
Authors: Li Xiaojuan , Huang Mutao , Wang Ronghui
Published: February 2020

Numerical simulation is an important method used in studying the evolution mechanisms of lake water quality. At the same time, lake water quality inversion technology using the characteristics of spatial optical continuity data from remote sensing satellites is constantly improving. It is, however, a research hotspot to combine the spatial and temporal advantages of both methods, in order to develop accurate simulation and prediction technology for lake water quality. This paper takes Donghu Lake in Wuhan as its research area. The spatial data from remote sensing and water quality monitoring information was used to construct a multi-source nonlinear regression fitting model (genetic algorithm (GA)-back propagation (BP) model) to invert the water quality of the lake. Based on the meteorological and hydrological data, as well as basic water quality data, a hydrodynamic model was established by using the MIKE21 model to simulate the evolution rules of water quality in Donghu Lake. Combining the advantages of the two, the best inversion results were used to provide a data supplement for optimization of the water quality simulation process, improving the accuracy and quality of the simulation. The statistical results were compared with water quality simulation results based on the data measured. The results show that the water quality simulation of chlorophyll a and nitrate nitrogen mean square errors fell to 17% and 24%, from 19% and 31% respectively, after optimization using remote sensing spatial information. The model precision was thus improved, and this is consistent with the actual pollution situation of Donghu Lake.
Life History and Host Preference of Trichopria drosophilae from Southern China, One of the Effective Pupal Parasitoids on the Drosophila Species
Authors: Yi Chuandong , Cai Pumo , Lin Jia , Liu Xuxiang , Ao Guofu , Zhang Qiwen , Xia Huimin , Yang Jianquan , Ji Qinge
Published: February 2020

This study aims to evaluate several life-history traits of a T. drosophilae population from southern China and its parasitic preference of three Drosophila species. For mated T. drosophilae females, the mean oviposition and parasitization period were 27.20 and 37.80 d, respectively. The daily mean parasitization rate was 59.24% per female and the lifetime number of emerged progeny was 134.30 per female. Trichopria drosophilae females survived 37.90 and 71.61 d under host-provided and host-deprived conditions, respectively. To assess the potential for unmated reproduction in T. drosophilae, the mean oviposition and parasitization period of unmated females was 22.90 and 47.70 d, respectively. They had a daily mean parasitization rate of 64.68%, produced a total of 114.80 offspring over their lifetime, and survived 52 d. Moreover, T. drosophilae showed a preference towards D. suzukii based on the total number of emerged offspring under a choice test. Our findings indicate that T. drosophilae from southern China appears to be suitable for the control of D. suzukii in invaded areas, due to its reproductive potential.
The Impact of Prostate Cancer Upgrading and Upstaging on Biochemical Recurrence and Cancer-Specific Survival
Authors: Bakavičius Arnas , Drevinskaitė Mingailė , Daniūnaitė Kristina , Barisienė Marija , Jarmalaitė Sonata , Jankevičius Feliksas
Published: February 2020

Background and Objectives: Significant numbers of prostate cancer (PCa) patients experience tumour upgrading and upstaging between prostate biopsy and radical prostatectomy (RP) specimens. The aim of our study was to investigate the role of grade and stage increase on surgical and oncological outcomes. Materials and Methods: Upgrading and upstaging rates were analysed in 676 treatment-naïve PCa patients who underwent RP with subsequent follow-up. Positive surgical margin (PSM), biochemical recurrence (BCR), metastasis-free survival (MFS), overall (OS) and cancer specific survival (CSS) were analysed according to upgrading and upstaging. Results: Upgrading was observed in 29% and upstaging in 22% of PCa patients. Patients undergoing upgrading or upstaging were 1.5 times more likely to have a PSM on RP pathology. Both upgrading and upstaging were associated with increased risk for BCR: 1.8 and 2.1 times, respectively. Mean time to BCR after RP was 2.1 years in upgraded cases and 2.7 years in patients with no upgrading (p < 0.001), while mean time to BCR was 1.9 years in upstaged and 2.8 years in non-upstaged cases (p < 0.001). Grade and stage increase after RP were associated with inferior MFS rates and ten-year CSS: 89% vs. 98% for upgrading (p = 0.039) and 87% vs. 98% for upstaging (p = 0.008). Conclusions: Currently used risk stratification models are associated with substantial misdiagnosis. Pathological upgrading and upstaging have been associated with inferior surgical results, substantial higher risk of BCR and inferior rates of important oncological outcomes, which should be considered when counselling PCa patients at the time of diagnosis or after definitive therapy.
Fracturing and Near-Surface Diagenesis of a Silicified Miocene Deltaic Sequence: The Montjuïc Hill (Barcelona)
Authors: Cantarero Irene , Parcerisa David , Plata Maria Alexandra , Gómez-Gras David , Gomez-Rivas Enrique , Martín-Martín Juan Diego , Travé Anna
Published: February 2020

Near-surface diagenesis has been studied in the Langhian siliciclastic rocks of the Montjuïc Hill (Barcelona Plain) by means of petrographical (optical and cathodoluminescence) and geochemical (electron microprobe, δ18O, δ13C, δ34S and 87Sr/86Sr) analyses. In the hill, these rocks are affected by strong silicification, but the same unit remains non-silicified at depth. The results reveal that fracturing took place after lithification and during uplift. Fracture cementation is clearly controlled by the previous diagenesis of the host rock. In non-silicified areas, cementation is dominated by calcite, which precipitated from meteoric waters. In silicified areas, fractures show multiepisodic cementation produced firstly by barite and secondly by silica, following the sequence opal, lussatite, chalcedony, and quartz. Barite precipitated only in fractures from the mixing of upflowing seawater and percolating meteoric fluids. The presence of silica stalactites, illuviation, and geopetal structures, and δ18O values indicate that silica precipitation occurred in the vadose regime from low-temperature percolating meteoric fluids, probably during a glacial period. Moreover, the presence of alunite suggests that silica cement formed under acidic conditions. Karst features (vugs and caverns), formed by arenisation, reveal that silica was derived from the dissolution of surrounding silicified host rocks.
Mute Sacrum. Faith and Its Relation to Heritage on Camino de Santiago
Authors: Roszak Piotr
Published: February 2020

The problem of recognizing the true motivations of secular pilgrims is often experienced on the Camino de Santiago. The faith of pilgrims seems to be hidden under the cover of many behaviors of contemporary pilgrims. At the same time on the Camino de Santiago, there could be observed a significant change in how the sacred is perceived by pilgrims: their experience is more related to “time” or “relation/event”, than “place”. The clue is the correct notion of religiosity, which for Thomas Aquinas was not a set of contents, but the relation to the ultimate end. In this light, the heritage can speak and manifest its message, when the relation is reestablished. With this theological background, I will try to answer the main question about the explanatory dimension of faith, its relation to the meaning of heritage and art and I will offer two proposals for the renewal of the theological approach to pilgrimage.
Mine Machine Radar Sensor for Emergency Escape
Authors: Hargrave Chad , Munday Lance , Kennedy Gareth , de Kock André
Published: February 2020

This paper presents the results of recent work to develop and trial a mine machine radar sensor for underground coal mine vehicles. There is an urgent industry need for an integrated solution to the problem of operating an underground vehicle in conditions of dense ambient dust and/or smoke, such as may occur in underground coal mines after a fire or explosion. Under these conditions, sensors such as cameras and lidar offer limited assistance due to their inability to penetrate thick dust. Thermal infrared can penetrate dust but still results in poor vision, as there is insufficient temperature contrast between the tunnel walls and the ambient air. Microwave radar sensors are able to penetrate the dust, and suitable radar sensors have been developed for use in the automation industry. Adapting such sensors for use in an underground coal mining environment was the focus of this research effort, and involved trialing a suitable sensor in dust and smoke chambers as well as trials in an underground coal mine with introduced dust. Data processing and the development of a suitable user interface were key aspects of the research. Since any sensor would have to operate in an explosive atmosphere, a related research work developed a flameproof dielectric enclosure to allow the use of the radar in the mine environment.
Towards Routine Mapping of Shallow Bathymetry in Environments with Variable Turbidity: Contribution of Sentinel-2A/B Satellites Mission
Authors: Caballero Isabel , Stumpf Richard
Published: February 2020

Satellite-Derived Bathymetry (SDB) has significant potential to enhance our knowledge of Earth’s coastal regions. However, SDB still has limitations when applied to the turbid, but optically shallow, nearshore regions that encompass large areas of the world’s coastal zone. Turbid water produces false shoaling in the imagery, constraining SDB for its routine application. This paper provides a framework that enables us to derive valid SDB over moderately turbid environments by using the high revisit time (5-day) of the Sentinel-2A/B twin mission from the Copernicus programme. The proposed methodology incorporates a robust atmospheric correction, a multi-scene compositing method to reduce the impact of turbidity, and a switching model to improve mapping in shallow water. Two study sites in United States are explored due to their varying water transparency conditions. Our results show that the approach yields accurate SDB, with median errors of under 0.5 m for depths 0–13 m when validated with lidar surveys, errors that favorably compare to uses of SDB in clear water. The approach allows for the semi-automated creation of bathymetric maps at 10 m spatial resolution, with manual intervention potentially limited only to the calibration to the absolute SDB. It also returns turbidity data to indicate areas that may still have residual shoaling bias. Because minimal in-situ information is required, this computationally-efficient technique has the potential for automated implementation, allowing rapid and repeated application in more environments than most existing methods, thereby helping with a range of issues in coastal research, management, and navigation.
A Two-Stream Symmetric Network with Bidirectional Ensemble for Aerial Image Matching
Authors: Park Jae-Hyun , Nam Woo-Jeoung , Lee Seong-Whan
Published: February 2020

In this paper, we propose a novel method to precisely match two aerial images that were obtained in different environments via a two-stream deep network. By internally augmenting the target image, the network considers the two-stream with the three input images and reflects the additional augmented pair in the training. As a result, the training process of the deep network is regularized and the network becomes robust for the variance of aerial images. Furthermore, we introduce an ensemble method that is based on the bidirectional network, which is motivated by the isomorphic nature of the geometric transformation. We obtain two global transformation parameters without any additional network or parameters, which alleviate asymmetric matching results and enable significant improvement in performance by fusing two outcomes. For the experiment, we adopt aerial images from Google Earth and the International Society for Photogrammetry and Remote Sensing (ISPRS). To quantitatively assess our result, we apply the probability of correct keypoints (PCK) metric, which measures the degree of matching. The qualitative and quantitative results show the sizable gap of performance compared to the conventional methods for matching the aerial images. All code and our trained model, as well as the dataset are available online.
Coast–Ship Bistatic HF Surface Wave Radar: Simulation Analysis and Experimental Verification
Authors: Ji Yonggang , Zhang Jie , Wang Yiming , Yue Chao , Gong Weichun , Liu Junwei , Sun Hao , Yu Changjun , Li Ming
Published: February 2020

The coast–ship bistatic high-frequency surface wave radar (HFSWR) not only has the anti-interference advantages of the coast-based bistatic HFSWR, but also has the advantages of maneuverability and an extended detection area of the shipborne HFSWR. In this paper, theoretical formulas were derived for the coast–ship bistatic radar, including the first-order sea clutter scattering cross-section and the Doppler frequency shift of moving targets. Then, simulation results of the first-order sea clutter spectrum under different operating conditions were given, and the range of broadening of the first-order sea clutter spectrum and its influence on target detection were investigated. The simulation results show the broadening ranges of the right sea clutter spectrum and left sea clutter spectrum were symmetric when the shipborne platform was anchored, whereas they were asymmetric when the shipborne platform was underway. This asymmetry is primarily a function of platform velocity and radar frequency. Based on experimental data of the coast–ship bistatic HFSWR conducted in 2019, the broadening range of the sea clutter and the target frequency shift were analyzed and compared with simulation results based on the same parameter configuration. The agreement of the measured results with the simulation results verifies the theoretical formulas.
Analyses of Namibian Seasonal Salt Pan Crust Dynamics and Climatic Drivers Using Landsat 8 Time-Series and Ground Data
Authors: Milewski Robert , Chabrillat Sabine , Bookhagen Bodo
Published: February 2020

Salt pans are highly dynamic environments that are difficult to study by in situ methods because of their harsh climatic conditions and large spatial areas. Remote sensing can help to elucidate their environmental dynamics and provide important constraints regarding their sedimentological, mineralogical, and hydrological evolution. This study utilizes spaceborne multitemporal multispectral optical data combined with spectral endmembers to document spatial distribution of surface crust types over time on the Omongwa pan located in the Namibian Kalahari. For this purpose, 49 surface samples were collected for spectral and mineralogical characterization during three field campaigns (2014–2016) reflecting different seasons and surface conditions of the salt pan. An approach was developed to allow the spatiotemporal analysis of the salt pan crust dynamics in a dense time-series consisting of 77 Landsat 8 cloud-free scenes between 2014 and 2017, covering at least three major wet–dry cycles. The established spectral analysis technique Sequential Maximum Angle Convex Cone (SMACC) extraction method was used to derive image endmembers from the Landsat time-series stack. Evaluation of the extracted endmember set revealed that the multispectral data allowed the differentiation of four endmembers associated with mineralogical mixtures of the crust’s composition in dry conditions and three endmembers associated with flooded or muddy pan conditions. The dry crust endmember spectra have been identified in relation to visible, near infrared, and short-wave infrared (VNIR–SWIR) spectroscopy and X-ray diffraction (XRD) analyses of the collected surface samples. According these results, the spectral endmembers are interpreted as efflorescent halite crust, mixed halite–gypsum crust, mixed calcite quartz sepiolite crust, and gypsum crust. For each Landsat scene the spatial distribution of these crust types was mapped with the Spectral Angle Mapper (SAM) method and significant spatiotemporal dynamics of the major surface crust types were observed. Further, the surface crust dynamics were analyzed in comparison with the pan’s moisture regime and other climatic parameters. The results show that the crust dynamics are mainly driven by flooding events in the wet season, but are also influenced by temperature and aeolian activity in the dry season. The approach utilized in this study combines the advantages of multitemporal satellite data for temporal event characterization with advantages from hyperspectral methods for the image and ground data analyses that allow improved mineralogical differentiation and characterization.
Optimal Inversion of Conversion Parameters from Satellite AOD to Ground Aerosol Extinction Coefficient Using Automatic Differentiation
Authors: Li Lianfa
Published: February 2020

Satellite aerosol optical depth (AOD) plays an important role for high spatiotemporal-resolution estimation of fine particulate matter with diameters ≤2.5 μm (PM2.5). However, the MODIS sensors aboard the Terra and Aqua satellites mainly measure column (integrated) AOD using the aerosol (extinction) coefficient integrated over all altitudes in the atmosphere, and column AOD is less related to PM2.5 than low-level or ground-based aerosol (extinction) coefficient (GAC). With recent development of automatic differentiation (AD) that has been widely applied in deep learning, a method using AD to find optimal solution of conversion parameters from column AOD to the simulated GAC is presented. Based on the computational graph, AD has considerably improved the efficiency in applying gradient descent to find the optimal solution for complex problems involving multiple parameters and spatiotemporal factors. In a case study of the Jing-Jin-Ji region of China for the estimation of PM2.5 in 2015 using the Multiangle Implementation of Atmospheric Correction AOD, the optimal solution of the conversion parameters was obtained using AD and the loss function of mean square error. This solution fairly modestly improved the Pearson’s correlation between simulated GAC and PM2.5 up to 0.58 (test R2: 0.33), in comparison with three existing methods. In the downstream validation, the simulated GACs were used to reliably estimate PM2.5, considerably improving test R2 up to 0.90 and achieving consistent match for GAC and PM2.5 in their spatial distribution and seasonal variations. With the availability of the AD tool, the proposed method can be generalized to the inversion of other similar conversion parameters in remote sensing.
Confidence Levels, Sensitivity, and the Role of Bathymetry in Coral Reef Remote Sensing
Authors: Goodman James A. , Lay Mui , Ramirez Luis , Ustin Susan L. , Haverkamp Paul J.
Published: February 2020

Remote sensing is playing an increasingly important role in the monitoring and management of coastal regions, coral reefs, inland lakes, waterways, and other shallow aquatic environments. Ongoing advances in algorithm development, sensor technology, computing capabilities, and data availability are continuing to improve our ability to accurately derive information on water properties, water depth, benthic habitat composition, and ecosystem health. However, given the physical complexity and inherent variability of the aquatic environment, most of the remote sensing models used to address these challenges require localized input parameters to be effective and are thereby limited in geographic scope. Additionally, since the parameters in these models are interconnected, particularly with respect to bathymetry, errors in deriving one parameter can significantly impact the accuracy of other derived parameters and products. This study utilizes hyperspectral data acquired in Hawaii in 2000–2001 and 2017–2018 using NASA’s Classic Airborne Visible/Infrared Imaging Spectrometer to evaluate performance and sensitivity of a well-established semi-analytical inversion model used in the assessment of coral reefs. Analysis is performed at several modeled spatial resolutions to emulate characteristics of different feasible moderate resolution hyperspectral satellites, and data processing is approached with the objective of developing a generalized, scalable, automated workflow. Accuracy of derived water depth is evaluated using bathymetric lidar data, which serves to both validate model performance and underscore the importance of image quality on achieving optimal model output. Data are then used to perform a sensitivity analysis and develop confidence levels for model validity and accuracy. Analysis indicates that derived benthic reflectance is most sensitive to errors in bathymetry at shallower depths, yet remains significant at all depths. The confidence levels provide a first-order method for internal quality assessment to determine the physical extent of where and to what degree model output is considered valid. Consistent results were found across different study sites and different spatial resolutions, confirming the suitability of the model for deriving water depth in complex coral reef environments, and expanding our ability to achieve automated widespread mapping and monitoring of global coral reefs.
Improving Policy Evidence Base for Agricultural Sustainability and Food Security: A Content Analysis of Life Cycle Assessment Research
Authors: Gava Oriana , Bartolini Fabio , Venturi Francesca , Brunori Gianluca , Pardossi Alberto
Published: February 2020

Life cycle assessment is a widespread method for measuring and monitoring the environmental impacts of production processes, thereby allowing the comparison of business-as-usual with more ecological scenarios. Life cycle assessment research can support evidence-based policy making by comparing and communicating the environmental impacts of agricultural and food systems, informing about the impact of mitigating interventions and monitoring sectoral progress towards sustainable development goals. This article aims at improving the contribution of science to evidence-based policies for agricultural sustainability and food security, while facilitating further research, by delivering a content-analysis based literature review of life cycle assessment research in agricultural and food economics. Results highlight that demand-side and system-level approaches need further development, as policies need to support redesigned agricultural systems and newly conceived dietary guidelines, which combine environmental protection and health benefits, without reducing productivity. Similarly, more research effort towards consequential life cycle assessment and multidimensional assessment may benefit policy makers by considering the rebound effects associated with the large-scale implementation of impact-mitigating interventions. Promising interventions involve the promotion of waste circularization strategies, which could also improve the profitability of agriculture. For effective policy making towards agricultural sustainability and food security worldwide, countries with the greatest expected population growth and raise of urbanization rates need more attention by researchers.
Method for the Reduction of Natural Losses of Potato Tubers During their Long-Term Storage
Authors: Jakubowski Tomasz , Królczyk Jolanta B.
Published: February 2020

The purpose of the study was to establish whether UV-C radiation applied to potato tubers prior to their storage affected their natural losses over a long period of time. A custom-built UV-C radiation stand constructed for the purpose of this experiment was equipped with a UV-C NBV15 radiator generating a 253.7 nm long wave with power density of 80 to 100 μW∙cm−2. Three varieties of edible medium late potatoes, Jelly, Syrena, and Fianna, were the objects of the research. The measurement of tightly controlled storage conditions was carried out over three seasons between 2016/2017 and 2018/2019, in a professional agricultural cold store with automated adjustment of interior microclimate parameters. The obtained data were processed using the variance analysis (α = 0.05). There was a statistically significant reduction in transpiration- and respiration-caused losses in the UV-C radiated potato tubers in comparison to those of the control sample. Additionally, the Jelly variety reacted to UV-C radiation demonstrating a reduction in sprout weight.
Impact of Age Management on Sustainability in Czech Organisations
Authors: Urbancová Hana , Vnoučková Lucie , Linhart Zdenek , Ježková Petrů Gabriela , Zuzák Roman , Holečková Lenka , Prostějovská Zita
Published: February 2020

Age management is becoming an increasingly important part of strategic human resources management practices and can ultimately lead to a competitive advantage. Research results confirmed that a strategic focus on the efficient use of all age categories of employees yields retention, the successful achievement of organisation goals, development, and, ultimately, a competitive advantage. The aim of this article is to identify and evaluate approaches to age management practices in organisations in 1271 organisations in the Czech Republic. Quantitative research was carried out in selected organisations operating over a three-year period. Data was gathered from these organisations and evaluated using descriptive and multidimensional statistics. The results show that those organisations focusing on the application of age management practices achieved a competitive advantage regardless of size or sector of the organisation. Statistical analysis (χ2 test, Cramer’s V, factor analysis) on survey data shows that many of these organisations achieved significant perceived benefits from the application of age management. The approach to age management application varies in organisations depending on whether it is an internal branding of an employer or response to a crisis. Organisations either use of best practices to implement age management or it is a carefully planned process in advance. Follow-up research can focus on the use of age management in crisis management or employer branding. This study is a non-experimental quantitative correlation analysis utilising longitudinal empirical data.
A Model for Sustainable Courier Services: Vehicle Routing with Exclusive Lanes
Authors: Lee Keyju , Chae Junjae , Song Bomi , Choi Donghyun
Published: February 2020

In Southeast Asian cities, it is common for logistic companies to operate a heterogeneous fleet of delivery vehicles with motorcycles being the preferred vehicle to handle the final phase of delivery. In such scenarios, heterogeneous fleet vehicle routing problem (HFVRP) is generally applied to plan an optimal delivery. However, in many downtown cores of large and rapidly developing Southeast Asian cities, HFVRP is neither viable nor reliable because of road usage restrictions. The purpose of this article is to develop and test a different approach that accurately takes these restrictions into account and provides viable and more sustainable results. Restrictions in this paper refer to situations of urban areas in Vietnam where (i) certain vehicle types are prohibited in specified areas or where narrow alleyways limit the utilization of vehicles that exceed the road capacity and (ii) certain roads are exclusive to certain vehicle types. In networks, limited access and exclusive lanes are represented as links, or arcs, exclusive to one or another. Taking these limitations into consideration, we have developed a unique model, which we have termed Vehicle Routing Problem with Exclusive Links (VRP-EL). The model was validated and tested for its performance on scenarios with varying ratios of exclusive links. Scenarios up to 500 customers were tested on a meta-heuristic algorithm, simulated annealing. VRP-EL produces realistic outcomes. Limiting certain links to be selected according to vehicle types increases overall travel distance. However, this increase outweighs the cost of re-planning and rerouting had they not been constrained initially. The reduction in traveling distance leads to fossil fuel reduction for the overall system. The estimation of reduced carbon emissions through applying the proposed model is presented. Considering the severe traffic congestion and carbon emissions caused by motorcycles in Vietnam, the proposed model leads to a sustainable road environment.
Probiotics in Animal Husbandry: Applicability and Associated Risk Factors
Authors: Alayande Kazeem Adekunle , Aiyegoro Olayinka Ayobami , Ateba Collins Njie
Published: February 2020

Probiotics have been emerging as a safe and viable alternative to antibiotics for increasing performance in livestock. Literature was collated via retrieved information from online databases, viz, PubMed, MEDLINE, ScienceDirect, Scopus, Web of Science and Google Scholar. Besides improved immunomodulation and nutrient digestibility, in-feed probiotics have shown drastic reductions in gastrointestinal tract-invading pathogens. However, every novel probiotic strain cannot be assumed to share historical safety with conventional strains. Any strain not belonging to the wild-type distributions of relevant antimicrobials, or found to be harbouring virulence determinants, should not be developed further. Modes of identification and the transmigration potential of the strains across the gastrointestinal barrier must be scrutinized. Other potential risk factors include the possibility of promoting deleterious metabolic effects, excessive immune stimulation and genetic stability of the strains over time. Adverse effects of probiotics could be strain specific, depending on the prevailing immunological and physiological condition of the host. The most crucial concern is the stability of the strain. Probiotics stand a good chance of replacing antibiotics in animal husbandry. The possibility of the probiotics used in animal feed cross-contaminating the human food chain cannot be downplayed. Thus, the established safety measures in probiotic development must be adhered to for a successful global campaign on food safety and security.