Editorial: Special issue on neural computing and applications in cyber intelligence: ATCI 2020

Editorial: Special issue on neural computing and applications in cyber intelligence: ATCI 202

Physiological traits of Acacia concurrens and Eucalyptus crebra with respect to radical site preparation practices in a revegetation trial, south east Queensland, Australia

Purpose: To successfully establish revegetation, there is a need for weed control. Herbicide application and top soil removal (scalping) may be used to suppress weeds. However, scalping alters soil water and nitrogen availability which in turn may affect plant physiology and performance during the early phase of establishment. Materials and methods: A field trial was established in south east Queensland, Australia, to examine weed control methods, including herbicide application and scalping. Plant survival, mean periodic height gain, specific leaf area and leaf-level physiological traits were measured for Acacia concurrens Pedley and Eucalyptus crebra F. Muell. for 17 months following tree establishment. Results and discussion: Plant survival and growth of A. concurrens were superior in the scalped area compared to the herbicide area, whereas neither survival nor growth of E. crebra was influenced by weed control methods. In general, there were no or little effect of site preparation practices on carbon and nitrogen isotope composition, specific leaf area, photosynthesis, maximum photosynthesis and instantaneous water-use efficiency. Photosynthetic capacity was not influenced by site preparation practices as reflected through the maximum rate of carboxylation and maximum rate of electron transport. Conclusions: Despite altering soil nutrient availability in the scalped areas and high weed coverage in the herbicide areas, there was no substantial alteration in plant physiology for both species. E. crebra was less affected by either low nutrient availability in the scalped areas or high weed coverage in the herbicide areas compared to A. concurrens. Therefore, E. crebra could be considered as a valuable species to revegetate degraded lands. © 2014 Springer-Verlag Berlin Heidelberg

Pedestrian detection by drones

The autonomous detection of UAV on ground targets is a crucial issue in intelligent cruise. In recent years，with therise of deep learning，convolutional neural networks have been tried to apply in the field of target recognition. This paper designs alight-weight convolution neural network model suitable for tiny target detection under UAV. Using UAV real shot samples in theNVIDIA-1080ti platform for verification，the processing speed is up to 82 frames / second.</p

Numerical simulation on combustion process and optimization of structure for the reclaimed copper reverberatory furnace

Some problems, such as high energy consumption, short life and high frequency maintenance, exist in reverberatory furnace which is the key equipment for production of reclaimed copper. Measurement data for energy balance indicate the major reasons are incomplete combustion and too high temperature at some location. In this paper, the coupling numerical simulation on fluid flow, heat transfer and combustion process in a prototype of reverberatory furnace is performed based on FLUENT software, and the boundary conditions result from the comprehensive thermal measurement. The simulating results are verified via measuring data from operating furnace. In terms of the analysis of velocity and temperature field, it is found that the location of burner is not reasonable. A series of simulations have been conducted to maximize the furnace performance. The major parameters investigated include burner construction and installation location. The simulation results assist in understanding the critical factors which affects the production index, thus providing insight into furnace optimization. © 2012 IEEE

Ecophysiological status of different growth stage of understorey Acacia leiocalyx and Acacia disparrima in an Australian dry sclerophyll forest subjected to prescribed burning

Purpose: Understorey Acacia spp. plays an important role in post-fire restoration because these understorey plants are tolerant to stress conditions. We investigated how the ecophysiological status of two species of understorey, Acacia leiocalyx and Acacia disparrima, varied depending on the plant growth stage after prescribed burning. Materials and methods: Plants were grouped in different size classes, namely seedlings, small and medium sizes, and physiological variables such as foliar gas exchange, water use efficiency and light dependency were measured at two experimental sites subjected to prescribed burning. Results and discussion: A. leiocalyx showed higher symbiotic N2 fixation and photosynthetic capacity compared to A. disparrima regardless of plant-size classes at both experimental sites. This could explain the greater relative growth rate of A. leiocalyx than that of A. disparrima. However, A. disparrima is more tolerant to shady conditions than A. leiocalyx. Conclusions: This finding may be an indication of how well these two species recover after fire, although A. leiocalyx may have faster regrowth, as it is fixing more N. © 2013 Springer-Verlag Berlin Heidelberg

Human footprints in urban forests: Implication of nitrogen deposition for nitrogen and carbon storage

Purpose: Rising levels of nitrogen (N) deposition are influencing urban forest carbon (C) and N dynamics due to greater human disturbance compared to those in rural areas. N deposition in combination with increased atmospheric carbon dioxide (CO2) and water limitation may alter C and N storage in urban forests. This review aimed to provide a better understanding of N and C storage under N deposition scenarios in urban forests. Results and discussion: Globally, fuel combustion and biomass burning contribute in approximately 70 and 16 % of the NOx emission respectively. It is also estimated that NHy and NOx are two to four times higher in urban forests compared to rural areas. However, higher N deposition may not always result in increased N and C storage in urban forests. In fact, urban forests may even show early symptoms of N and C losses under climate change. For example, urban forests in fire-prone areas require higher frequency of burning to reduce the threat of wildfires, leading to an acceleration of C and N loss. Additionally, chronic N deposition may result in an early N loss in urban forests due to faster N saturation and soil acidification in urban forests compared to rural forests. Studies of N deposition on urban forests using N isotope composition (δ15N) also showed that N loss from urban forests can occur through the direct leaching of the deposited NO3−-N. We also noted that using different 15N signal of soil and plant in combination of tree ring δ15N may provide a better understanding of N movement in urban forests. Conclusions: Although urban forests may become a source of C and N faster than rural forests, N-limited urban forests may benefit from N deposition to retain both N and C stocks longer than non-N-limited urban forests. Appropriate management practices may also help to delay such symptoms; however, the main source of emission still needs to be managed to reduce both N deposition and rising atmospheric CO2 in urban forests. Otherwise, the N and C stocks in urban forests may further decline when prolonged drought conditions under global climate change increase the frequency of fires and reduce plant photosynthesis. © 2015, Springer-Verlag Berlin Heidelberg

Effects of pre-planting site management on soil organic matter and microbial community functional diversity in subtropical Australia

Weed control is a key factor affecting early plant growth and establishment in revegetation projects in South-east Queensland of sub-tropical Australia. Costs associated with weed control are significant and methods which reduce establishment costs and effectively suppress weeds are of great interest. However, different methods may have implications for soil quality and fertility and require a detailed investigation. Understanding the response of soil organic matter (SOM) and microbial functional diversity to different weed control methods is crucial as they affect soil quality and nutrient availability. A field trial was established in South-east Queensland to identify the effects of three methods of weed control: (1) glyphosate, (2) a mixture of glyphosate and MCPA and (3) topsoil removal or scalping on SOM, microbial biomass, soil respiration, NH4+-N availability, potentially mineralisable N (PMN) and soil microbial community functional diversity (as assessed by carbon substrate utilisation using Biolog GN2 plates). The scalped area had lower SOM and microbial activity compared to the herbicide and control plots. There was no significant difference in water soluble organic carbon (WSOC), hot water extractable organic C (HWEOC), hot water extractable total N (HWETN) and microbial biomass C and N (MBC and MBN) between the herbicide and control plots, particularly at week 20. NH4+-N and PMN values were lower at week 20 than week 1 in the herbicide and scalping treatments. Week 20 was the end of the growing season and reduction in N availability may have been the result of decreasing temperature. Principal component analyses (PCA) from Biolog GN2 results indicated a separation in soil microbial community function in the scalped area compared to the other treatments which may have implications for soil properties in the long term.Scalping proved to be the most cost-effective method of site preparation, requiring fewer site visits for weed control compared to herbicide application. However, SOM was significantly affected by scalping due to topsoil removal and it may not be a sustainable practice in short rotation plantation establishment. Single herbicide application at field rates did not impact soil organisms but also failed to achieve proper weed control. © 2012 Elsevier B.V

Prediction of soil macro- and micro-elements in sieved and ground air-dried soils using laboratory-based hyperspectral imaging technique

Hyperspectral image analysis in laboratory-based settings has the potential to estimate soil elements. This study aimed to explore the effects of soil particle size on element estimation using visible-near infrared (400–1000 nm) hyperspectral imaging. Images were captured from 116 sieved and ground soil samples. Data acquired from hyperspectral images (HSI) were used to develop partial least square regression (PLSR) models to predict soil available aluminum (Al), boron (B), calcium (Ca), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), sodium (Na), phosphorus (P) and zinc (Zn). The soil available Al, Fe, K, Mn, Na and P were not predicted with high precision. However, the developed PLSR models predicted B (R2 CV = 0.62 and RMSECV = 0.15), Ca (R2 CV = 0.81 and RMSECV = 260.97), Cu (R2 CV = 0.74 and RMSECV = 0.27), Mg (R2 CV = 0.80 and RMSECV = 43.71) and Zn (R2 CV = 0.76 and RMSECV = 0.97) in sieved soils. The PLSR models using reflectance of ground soil were also developed for B (R2 CV = 0.53 and RMSECV = 0.16), Ca (R2 CV = 0.81 and RMSECV = 260.79), Cu (R2 CV = 0.73 and RMSECV = 0.29), Mg (R2 CV = 0.79 and RMSECV = 45.45) and Zn (R2 CV = 0.76 and RMSECV = 0.97). RMSE of different PLSR models, developed from sieved and ground soils for the corresponding elements did not significantly differ based on the Levene's test. Therefore, this study indicated that it was not necessary to grind soil samples to predict elements using HSI. © 2018 Elsevier B.V

Stabilizing mechanism and running behavior of couplers on heavy haul trains

Published studies in regard to coupler systems have been mainly focused on the manufacturing process or coupler strength issues. With the ever increasing of tonnage and length of heavy haul trains, lateral in-train forces generated by longitudinal in-train forces and coupler rotations have become a more and more significant safety issue for heavy haul train operations. Derailments caused by excessive lateral in-train forces are frequently reported. This article studies two typical coupler systems used on heavy haul locomotives. Their structures and stabilizing mechanism are analyzed before the corresponding models are developed. Coupler systems models are featured by two distinct stabilizing mechanism models and draft gear models with hysteresis considered. A model set which consists of four locomotives and three coupler systems is developed to study the rotational behavior of different coupler systems and their implications for locomotive dynamics. Simulated results indicate that when the locomotives are equipped with the type B coupler system, locomotives can meet the dynamics standard on tangent tracks; while the dynamics performance on curved tracks is very poor. The maximum longitudinal in-train force for locomotives equipped with the type B coupler system is 2000 kN. Simulations revealed a distinct trend for the type A coupler system. Locomotive dynamics are poorer for the type A case when locomotives are running on tangent tracks, while the dynamics are better for the type A case when locomotives are running on curved tracks. Theoretical studies and simulations carried out in this article suggest that a combination of the two types of stabilizing mechanism can result in a good design which can significantly decrease the relevant derailments

Nitrogen and carbon cycling associated with litterfall production in monoculture teak and mixed species teak and flueggea stands

Purpose: High demand for teak (Tectona grandis L.f.), a species of economic importance, was the reason Solomon Islands experienced a surge in community-wide planting of monoculture teak stands in the last two decades. Mixed species planting of teak and flueggea (Flueggea flexuosa Muell. Arg.) was introduced to overcome the reluctance of growers to thin their stands. However, there is lack of information on the effect of changing from monoculture to mixed species plantings on the cycling of nutrients especially carbon (C) and nitrogen (N). Materials and methods: This study assessed litter quantity and quality, total C (TC), total N (TN), C:N ratio and C and N isotope compositions (δ13C and δ15N) over 18 months at two sites (Ringgi and Poitete). The treatments included teak planted at 833 stems per hectare (sph) (T1), teak planted in rows with two rows of flueggea at 833 sph (T2), 625 sph (T3) and 416 sph (T4), and teak planted in alternating rows with flueggea at 833 sph (T5). Results and discussion: Treatment 1 (T1) produced significantly higher total litter than T4 at Ringgi. However, based on individual tree litterfall production, teak in T4 (lowest stocking rate) at both trials produced higher litter per tree than the teak in T3, T2, T5 and T1 while there was no significant difference with litter production of flueggea. An enrichment of litter δ15N was observed over time in either species, which suggested an increased N loss and transformations in both experimental sites. When comparing each treatment and using individual tree productivity, T4 significantly produced and returned higher litter TC and TN than T3, T2, T5 and T1. Conclusions: Overall, individual tree productivity demonstrated that mixed species stands had a significant potential for cycling higher rates of C and N than monoculture teak stands. Therefore, establishment of mixed species stands, especially T4 and T3, was recommended as a practical measure to address the widely experienced problem of reluctance by growers to thin high value trees while preserving the balance of C and N inputs into the ground