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The increasing role of unmanned aerial vehicle (UAV) swarms in modern warfare poses a significant challenge to ground and air defense systems. Considering complex terrain environments and multi-sensor resources including radar and photoelectric systems constraints, a novel multi-sensor dynamic scheduling algorithm is proposed in this paper. Firstly, a transmission model with Fresnel zone under complex terrain and sensor models for radar/photoelectric systems are established. Considering the constraints of 6 factors, such as pitch angle, array scanning angle and threat levels, a detection model is developed subsequently. Secondly, to meet the real-time requirements of ground and air defense systems, a fast calculation method for Fresnel zone clearance using adaptive buffer is achieved. Thirdly, an improved Hungarian algorithm is proposed to solve the combinatorial optimization problem of sensor scheduling. Finally, simulation experiments are conducted to evaluate the algorithm performance under different conditions. The results demonstrate that the proposed approach significantly reduces the sensor switching rate while achieving a high sensor-UAV matching rate and high-threat matching rate. Furthermore, the simulation results verify the effectiveness of the proposed algorithm when applied to multi-sensor scheduling for defending UAV swarms. • Modern militaries need advanced sensor scheduling solutions to defend UAV. • Considering the Fresnel zone under complex terrain is crucial. • Adaptive buffer enables rapid calculation of Fresnel zone clearance. • Multiple sensor constraints make scheduling problems realistic. • Improved algorithm effectively enhances matching rates while reducing switching. [ABSTRACT FROM AUTHOR]

When legged robots perform complex tasks in unstructured environments, falls are inevitable due to unknown external disturbances. However, current research mainly focuses on the locomotion control of legged robots without falling. This paper proposes a comprehensive decision-making and control framework to address the falling over of quadruped robots. First, a capturability-based fall prediction algorithm is derived for planar single-contact and 3D multi-contact locomotion with a predefined gait sequence. For safe fall control, a novel contact-implicit trajectory optimization method is proposed to generate both state and input trajectories and contact mode sequences. Specifically, incorporating uncertainty into the system and terrain models enables mitigating the non-smoothness of contact dynamics while improving the robustness of the resulting trajectories. Furthermore, a model-free deep reinforcement learning-based approach is presented to achieve fall recovery after the robot completes a fall. Experimental results demonstrate that the proposed fall prediction algorithm accurately predicts robot falls with up to 95% accuracy approximately 395ms in advance. Compared to classical locomotion controllers, which often struggle to maintain balance under significant pushes or terrain perturbations, the presented framework can autonomously switch to the fall controller approximately 0.06s after the perturbation, effectively preventing falls or achieving recovery with a threefold reduction in touchdown impact velocity. These findings highlight the effectiveness of the proposed framework in enhancing the stability and safety of legged robots in unstructured environments. • The proposed fall prediction approach exhibits significantly enhanced reliability and flexibility. • The proposed controller can autonomously generate contact sequences, reducing damage from falls. • The designed reinforcement learning-method improves efficiency and robustness in fall recovery. [ABSTRACT FROM AUTHOR]

Confronted with budgetary constraints and complex sustainment systems in challenging environments, optimization of supply chains has become a necessity. The paper investigates a large body of literature related to integrated and decomposed supply chain problems' modeling, optimization software and mathematical programming, including analytical and heuristic solution methods. The main purpose of this study is to contribute with a review of global optimization models of forward/reverse crisis relief supply chains within tactical and operational levels before developing an Integrated Three-Echelon Multi-Period Multi-Commodity Inventory-Production-Distribution Problem formulation. It aims to minimize the total cost of inventory, production, transportation and shortage penalties from support facilities to satisfy deterministic non-stationary demand of finished and recovered repaired commodities over T periods. Besides functions integration and constraints, no such elaborated decision model has also considered before, simultaneously direct shipments in heterogeneous vehicles with non-stationary demand, hostility attrition, and the loading and safety constraints of heterogeneous commodities clustering and vehicle-commodity compatibility. This work shows how existing modeling approaches are valuable and inspiring to understand and adapt to complex new real-world supply chains with the unique proposed formulation and anticipated upgrades. It receives growing attention worldwide from business, humanitarian and military decision-makers, as well as from automotive industries, to build efficient supply chain strategies, how vital economically, socially and environmentally. This mathematical model leads to an NP-hard mixed integer linear programming (MILP) problem with too many variables and constraints where some promising solution methods are discussed. What we have investigated and modeled so far appeal to a further contribution of a sophisticated solution approach, decomposing it into sub-problems, more tractable through Lagrangian relaxation for lower bounds, or branch-and-price based column generation method. [ABSTRACT FROM AUTHOR]

Existing algorithms for terrain extraction from LiDAR require data to be structured in either a regular grid or triangulated irregular network (TIN) format, and they involve two-step processes; namely filtering and interpolation. This paper introduces a new terrain model based on reversing common interpolation techniques. A new method is presented to extract terrain directly through the inverse interpolation model in a single step. In addition, no raster or TIN format is required to represent the LiDAR data. Instead, points can be processed sequentially as obtained by the laser scanner. Furthermore, additional constraints for handling missing data, which occurs within waterbodies or occluded areas, are introduced in this paper. Several examples of extracted terrain in a variety of scenarios are presented and compared to results from existing algorithms both numerically and visually by inspecting vertical profiles across the data. The new terrain model was found to be in very close proximity to that obtained using existing methods but the former provided a smoother version of the terrain. [ABSTRACT FROM AUTHOR]

Path searching is challenging problem in many domains such as simulation war games, robotics, military mission planning, computer generated forces (CGF), etc. Effectiveness problems in military route planning are related both with terrain modelling and path planning algorithms. These problems may be considered from the point of view of many criterions. It seems that two criterions are the most important: quality of terrain reflection in the terrain model and computational complexity of the on(off)-line path planning algorithm. The paper deals with two above indicated problems of route planning effectiveness. Comparison of approaches used in route planning is presented. The hybrid, terrain merging-based and partial path planning, approach for route planning in dynamically changed environment during simulation is described. It significantly increase effectiveness of route planning process. The computational complexity of the method is given and some discussion for using the method in the battlefield simulation is conducted. In order to estimate how many times faster we can compute problem for finding shortest path in network with n big squares (b-nodes) with relation to problem for finding shortest path in the network with V small squares (s-nodes) acceleration function is defined and optimized. [ABSTRACT FROM AUTHOR]

This paper introduces an implementation of different GIS tools into Streamlit application: FCNN Terrain Classification, Earth Engine Dataset Parsing, and GIS Timelapse Animations. This toolkit is integrated with terrain multi-classification models using Fully Convolutional Neural Networks (FCNNs) for imagery data into Streamlit microservices. The proposed methodology involves labeled and unlabeled data collection from ESA WorldCover and Sentinel-2 MSI on the Google Earth Engine, compressing datasets into TFRecords format with 9 diverse terrain types, and handling Google Cloud training computations. The experimental results demonstrate the effectiveness of the CNN-based approach, achieving a tolerable from 60% up to 80% accuracy of the model and robust classification performance. The simplicity and efficiency of the proposed method make it suitable for real-world tasks requiring reliable and fast GIS analytics. [ABSTRACT FROM AUTHOR]

Many remote sensing and geoscience applications require a highprecision terrain model. In 2022, the Forest And Buildings removed Copernicus digital elevation model (fabdem) was released, in which trees and buildings were removed at a 30 m resolution. Therefore, it was necessary to make a comprehensive evaluation of this model. This research aims to perform a qualitative and quantitative analysis of fabdem in comparison with the commonly used global dems. We investigated the effect of the terrain slope, aspect, roughness, and land cover types in causing errors in the topographic representation of all dems. The fabdem had the highest overall vertical accuracy of 5.56 m. It was the best dem in representing the terrain roughness. The fabdem and Copernicus dem were equally influenced by the slopes more than the other models and had the worst accuracy of slope representation. In the tree, built, and flooded vegetation areas of the fabdem, the mean errors in elevation have been reduced by approximately 3.34 m, 1.26 m and 1.55 m, respectively. Based on Welch's t-test, there was no significant difference between fabdem and Copernicus dem elevations. However, the slight improvements in the fabdem make it the best filtered dem to represent the terrain heights over different land cover types. [ABSTRACT FROM AUTHOR]

This paper constructs the economic model to consider the economy in cities from the waste management perspective. Specifically, we analyze the link between migration, natural capital, and waste management by applying the new economic geography model. We show the results; the population distribution pattern in the long run varies depending on the congestion effect of natural capital and waste management's technological level. In particular, a full agglomeration equilibrium realizes in the long run for higher technological levels of waste management (lower congestion effects), an interior asymmetric equilibrium does for intermediate technological levels (intermediate congestion effects), and the symmetric dispersion equilibrium realizes for the lower technological levels (higher congestion effects). [ABSTRACT FROM AUTHOR]

Copyright of Revista de Climatología is the property of Revista de Climatologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The morpho-tectonic characteristics of the study area were evaluated due to paleo-tectonic significance. The Upper Tons Basin is associated with the Ganga river system, originated over the fracture zones produced after the collision of Indian and Eurasian plates; hence, the study region has its tectonic importance with small-scale tectonic deformation. The relief, drainage and tectonic characteristics are analyzed by using digital elevation model and topographical maps, geomorphic indices, lineaments and transverse profiles. Result reveals that two-third areas are in declining from mature stage (HI < 0.50) or monadnock phase (HI < 0.40). The value of basin asymmetry factor is suggesting right-side tilting of the trunk stream due to the tributaries of the Tons river originating over the Bhander uplands being longer. Further, the comparison of the stream length gradient with normalized stream length gradient shows delineating tectonically anomalous regions, and the anomalous points are addressed in the longitudinal profiles. The scarps fronts of the plateau are more sinuous and highly eroded, while the straight Kaimur fronts indicate relatively sensitive fronts. The relative tectonic activity index helps to evaluate the potential tectonic activity of a drainage basin and drainage network developed over the tectonically pre-designed valley. [ABSTRACT FROM AUTHOR]

Autonomous safe landing of UAVs is an important and challenging task in unknown environments, as almost no prior scene information can be leveraged for navigation. Most existing methods cannot address this issue completely, due to terrain uncertainty and system complexity. In this paper, we present a novel and complete framework for UAVs landing, which is built on point cloud in coarse-to-fine manner. Besides, our framework is designed with modularity and has four modules: point cloud preprocessing, coarse landing site selection, fine terrain evaluation, and landing optimal model. Specifically, a composite preprocessing scheme is applied to simultaneously filter noise, generate 3D Octo-map and plan the path on the raw point cloud. To balance the accuracy and real-time of the landing system, only promising coarse landing locations are automatically selected by adopting the proposed multi-stage process in grid-map. Based on the result of coarse stage, a fine-grained 3D validation is modeled by multiple terrain factors, which can further improve landing safety. Finally, a novel landing optimal model fuses terrain condition, fuel consumption, and second landing validation to determine the final landing sites during descent. Extensive experiments have been successfully conducted on different real-world and unknown environments, verifying that our method can select safe landing sites for UAVs robustly. Additionally, the system is further evaluated under normal, emergency, and rescue situations respectively to highlight different landing requirements. • A UAVs landing framework is proposed using a coarse-to-fine manner. • We use the multi-stage process to select coarse landing locations automatically. • A fine-grained terrain evaluation is introduced considering multiple factors. • An optimal model is designed to determine the final landing sites. [ABSTRACT FROM AUTHOR]

“Camouflage” is a natural or nature identical phenomenon where the sensory route of vision is delayed to avoid visual detection. Reducing detection capability and hiding in the background environment is critical for Army vehicles, equipment, and soldiers. This research aims to implement a process that will generate digital camouflage patterns specific to the terrain. The adapted digital pattern helps an object blend symmetrically into the background environment. Pixelated textures combine macro and micro designs that blend with ambient shrubs, trees, branches, and shadows. The technique presented in this paper consists of the following main modules: terrain classification model, pixelated camouflage texture generation, and texture evaluation. Experiments have been conducted to detect camouflage objects in the scene to evaluate the performance of the resultant camouflage texture generated for a natural environment. Photo simulation and saliency maps for hidden object detection have been used to evaluate the effectiveness of generated textures for a given terrain. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Kirsehir Education Faculty is the property of Journal of Kirsehir Education Faculty and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista de Climatología is the property of Revista de Climatologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Archaeologia Lituana is the property of Vilnius University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article examines the use of the Grob G 115E simulator (GO simulator) in Air Force elementary flight training, its technical features, and their impact on various areas of training. Questions about the use of the GO simulator will be answered through expert interviews and a user experience survey for flight instructors. In this way, the usefulness of the simulator was investigated. According to the results obtained, the GO simulator and simulator training in general are an invaluable part of flight training. The realistic cockpit environment and avionics of the GO simulator, combined with precise terrain modeling and good maneuverability, create a high-performance entity capable of meeting the requirements of basic flight training. According to the user experience of flight instructors, the simulator is excellent in its function and, above all, easy to use and reliable. [ABSTRACT FROM AUTHOR]

The real-time rendering of large-scale terrain scenes has been a challenge and is a popular research topic in the fields of 3D games and virtual reality. To fully utilize GPU features, this paper proposes a real-time rendering algorithm for large-scale regular grid terrain based on GPU Tessellation. The CPU processes a coarse-grained quadtree to generate terrain patches and then passes the patches to the GPU after view culling. Then, the GPU refines the terrain by using GPU Tessellation and displacement mapping. The most important advantage of our method is that during the tessellation stage, a new rule that the distance, screen space projection error and variance of the height, as the standard of terrain roughness, is designed. During the tessellation stage, the distance, screen space projection error and variance of the height, as the standard of terrain roughness, are considered. The experimental results show that our algorithm can greatly reduce the CPU processing time and main memory space requirement, and fully utilize the new features of the GPU; In conclusion, the proposed approach can render large-scale terrain with high-precision in real-time. [ABSTRACT FROM AUTHOR]

Water movement over and through soil is largely driven by topography and soil management across landscapes. This research tested the hypothesis that the water movement determines the potential for P and Ca redistribution and pH variance across landscapes. This hypothesis was evaluated by using digital elevation model‐derived terrain attributes in fields after 55 yr of broiler litter applications on pastures in Smith County, Mississippi. Results show that soils receiving broiler litter had mean Mehlich‐3 P levels of 1221.8 mg kg−1 at 0‐ to 15‐cm depth and 618.6 mg kg−1 at 15‐ to 30‐cm depth, and Ca with mean values of 768.3 and 645.0 mg kg−1 at 0‐ to 15‐cm and 15‐ to 30‐cm soil depths, respectively. Across fields, soils in areas of predicted convergent flow contained higher P, Ca, and lower pH values in the upper 0 to 15 cm, suggesting contributions via surface overland flow from areas with higher elevation and lower slope gradient. On the other hand, soils in areas with lesser slope and higher elevation also contained high levels of P, Ca, and pH for the subsurface soil depth, suggesting that vertical flow of water on this landscape is a mechanism for movement of P and Ca deeper in the profile. The incorporation of topographic characteristics across fields offers promising results that may be incorporated into improved P indices and management, making them more robust indicators of P mobilization to waterways. Core Ideas: Overland and vertical water flow is a mechanism for redistribution of P and Ca.The selected terrain attribute model provides insight for landscape nutrient distribution.Terrain attribute knowledge helps sampling and targeting best management practices. [ABSTRACT FROM AUTHOR]

For underwater terrain-aided navigation systems to collect enough terrain features, a path-planning method for terrain-aided navigation is proposed. First, a distribution model of terrain features is built based on underwater terrain Fisher information content. Then, terrain information and path length are taken as optimization targets, and considering the constraints of autonomous underwater vehicle (AUV) maneuverability, a path applicable to terrain-aided navigation can be provided. Simulation tests show that the terrain feature information in AUVs’ sailing area obtained with the method is adequate; therefore, this method can effectively improve the performance of terrain-aided navigation systems. [ABSTRACT FROM AUTHOR]

Many countries and regions have adopted various incentive land policies to promote industrial agglomeration, but the effect of these policies is limited. This paper extends the new economic geography model, introduces the guiding role of land policy on industrial agglomeration, and explores the rules of land supply affecting industrial agglomeration based on the four cases of Chengdu, Beijing, Shandong, and Shenzhen in China. The study shows that (1) A stable equilibrium for the manufacturing industry agglomeration may still be formed for enterprises not highly dependent on land without incentive land policies. (2) For enterprises with moderate dependence on the land, elastic adjustment of the land supply according to the land demand has a positive effect on the stable equilibrium of industrial agglomeration. (3) For enterprises highly dependent on land, the effect of incentive land supply policies to promote industrial agglomeration may not be significant. (4) Small-scale agricultural land expropriation can, to a certain extent, promote the agglomeration of manufacturing industries. However, suppose the cost of manufacturing land reduced by agricultural land expropriation cannot compensate for the increase in the cost of agricultural products due to the reduction of agricultural land. In that case, the market crowding effect that promotes the dispersion of enterprises still exists. Therefore, the government should fully examine the degree of dependence on the land of various enterprises and formulate targeted land policies, measure the scope of land expropriation that does not disturb the agricultural market, stabilize the cost of agricultural products required by the manufacturing industry, and realize the stable agglomeration for the manufacturing industry from a comprehensive perspective with agriculture incorporated. • I introduced land policy into NEG model and analyzed the impact of land supply on industrial agglomeration. • Exploring spatial forms of industrial development beyond the classic equilibrium. • The degree of dependence on land determines which land policies are more effective for industrial agglomeration. • Large-scale agricultural land expropriation cannot promote the formation of a stable industrial agglomeration. [ABSTRACT FROM AUTHOR]

Copyright of Environmental Research, Engineering & Management / Aplinkos Tyrimai, Inžinerija ir Vadyba is the property of Institute of Environmental Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Terrain conditions, stand structure attributes, and environmental factors are important elements that determine the success of timber harvests. Planning designs for timber harvesting projects must also be physically feasible, environmentally acceptable, and economically viable and address potentially competing objectives upfront in a multi-purpose planning effort. Under mountainous conditions involving highly variable and steep terrain, harvest planning is a particularly complex decision-making process. Here, quantitative (objective) information (e.g., stand volume) is jointly considered with qualitative (subjective) information (e.g., expert judgment of slope failure event and preference value of a certain stand) to arrive at a compromise plan that considers conflicting management objectives. The objective of this paper was to evaluate the existing terrain conditions of a large management area to find zones in which harvest operations can be conducted, assess which portions of the terrain can be harvested by different equipment that is available in the region, and locate landing sites for ground-based skidding operations. The criteria used in this study included quantitative and qualitative elements that were measured/evaluated across different scales. To address this complex decision-making process, we used an integrative approach that combined spatial analyses with multiple-criteria decision analysis (SMCDA). Existing geospatial data were combined with information obtained through pairwise evaluations of environmental, topographic, and stand structure elements to create maps in which the terrain was divided into zones of different suitability classes for timber harvests, placement of landing sites, and deployment of different harvesting systems. The results and assessment of this case study indicate that the methodology has great potential for a more integrated policy, in particular, where multiple spatial objectives explicitly need to be taken into consideration when solving complex forest-management problems in mountainous conditions. One key finding from this work that needs to be further explored involves efficient ways of incorporating this methodology into traditional harvest scheduling models to better support the operational and tactical phases of the timber harvesting. [ABSTRACT FROM AUTHOR]

Reliability Block Diagrams (RBDs) allow us to model the failure relationships of complex systems and their sub-components and are extensively used for system reliability, availability and maintainability analyses. Traditionally, these RBD-based analyses are done using paper-and-pencil proofs or computer simulations, which cannot ascertain absolute correctness due to their inaccuracy limitations. As a complementary approach, we propose to use the higher-order logic theorem prover HOL to conduct RBD-based analysis. For this purpose, we present a higher-order logic formalization of commonly used RBD configurations, such as series, parallel, parallel-series and series-parallel, and the formal verification of their equivalent mathematical expressions. A distinguishing feature of the proposed RBD formalization is the ability to model nested RBD configurations, which are RBDs having blocks that also represent RBD configurations. This generality allows us to formally analyze the reliability of many real-world systems. For illustration purposes, we formally analyze the reliability of a generic Virtual Data Center (VDC) in a cloud computing infrastructure exhibiting the nested series-parallel RBD configuration. [ABSTRACT FROM AUTHOR]

We study the interference from a rotating shipborne radar system that spectrally and spatially coexists with a Long Term Evolution (LTE) cellular communications network in the 3.5 GHz band to investigate the feasibility of LTE deployment in the United States coastal metropolitan cities in that band. First, we simulate the radar systems with realistic operational parameters. Furthermore, we leverage a detailed 3GPP-compliant LTE simulation with a sophisticated air interface modeling and investigate sensitivity of LTE to radar interference in macro cell, outdoor small cell, and indoor small cell scenarios. We simulate the propagation conditions between the radar and LTE system by adopting the Free Space Path Loss and Irregular Terrain Model commonly leveraged by National Telecommunications and Information Administration (NTIA), to account for propagation, diffraction, and troposcatter losses that the radar pulses undergo before they reach the LTE system. As a performance metric, we evaluate the throughput of the LTE system in the uplink direction for various distances between the radar and the cellular system. Our simulation results indicate an LTE link will remain operational even in severe interference conditions. In fact, the LTE system as close as 100 km away from the radar undergoes less than 10 % throughput loss from the LTE total throughput, and the throughput loss is less than 30 % when the radar is only 50 km away from the LTE. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to obtain thematic maps and topographic analyses determined on the field and processed through the basic programs of AutoCAD, TopoLT and Global Mapper which along with topogeodezical details high up in on the field to create a database required to implement a feasibility study, as a previous step of the general cadastre in the Farcasesti village, Gorj county. Topographical surveying were made with GNSS technology using the RTK-Kinematic method, South V-82 type in Real Time and data processing was performed by specialized graphics programs. Field data collected with GPS RTK were transferred to a computer using specialized software LeicaGeo Combined Office and other software like Notepad, Excel, Word, AutoCAD 2013. The imported data from the field in three spatial coordinates, respectively X, Y and Z, were the basis for drawing up planimetric situation plans by outlining the details of the terrain and elevation. In the present paper, we demonstrate that the use of GPS technology made possible topogeodezical data collection from a large area with high precision in a short time using reduced material and human resources. This allowed us to import data from the field by using topogeodezical specialized programs and accurately achieve the outlines of buildings and perimeter, as verified by superimposing them on orthophotomap. Achieving digital plans using AutoCAD Architectural demonstrated that they can be made with accuracy and precision permitting various analyzes of land, including the construction of contour in 2D and 3D. [ABSTRACT FROM AUTHOR]

Researchers in science education have for some time recognised the need for teachers to develop an awareness of students' common alternative conceptions - a key element of pedagogical content knowledge (PCK) - and use this knowledge to develop student understanding (Morrison & Lederman, 2003). Less attention, however, has been devoted to the investigation of geography teachers' awareness of and work with students' ideas. This paper outlines what is currently known about the nature of alternative conceptions in physical geography, teachers' knowledge of these ideas and their use of this knowledge to inform instruction. The paper proposes a framework to explain the factors affecting the development of geography teachers' knowledge in this area and their application of this knowledge in the classroom. Implications of the framework for pre-service training, and the accreditation and ongoing professional learning of geography teachers, are discussed along with directions for future research. [ABSTRACT FROM AUTHOR]

Characterization of wind flows over a complex terrain, especially mountain-gorge terrain (referred to as the very complex terrain with rolling mountains and deep narrow gorges), is an important issue for design and operation of long-span bridges constructed in this area. In both wind tunnel testing and numerical simulation, a transition section is often used to connect the wind tunnel floor or computational domain bottom and the boundary top of the ten-ain model in order to generate a smooth flow transition over the edge of the terrain model. Although the transition section plays an important role in simulation of wind field over complex terrain, an appropriate shape needs investigation. In this study, two principles for selecting an appropriate shape of boundary transition section were proposed, and a theoretical curve serving for the mountain-gorge terrain model was derived based on potential flow theory around a circular cylinder. Then a two-dimensional (2-D) simulation was used to compare the flow transition performance between the proposed curved transition section and the traditional ramp transition section in a wind tunnel. Furthermore, the wind velocity field induced by the curved transition section with an equivalent slope of 30° was investigated in detail, and a parameter called the 'velocity stability factor' was defined; an analytical model for predicting the velocity stability factor was also proposed. The results show that the proposed curved transition section has a better flow transition performance compared with the traditional ramp transition section. The proposed analytical model can also adequately predict the velocity stability factor of the wind field. [ABSTRACT FROM AUTHOR]

Targeting microglial activation is emerging as a clinically promising drug target for neuropathic pain treatment. Fexofenadine, a histamine receptor 1 antagonist, is a clinical drug for the management of allergic reactions as well as pain and inflammation. However, the effect of fexofenadine on microglial activation and pain behaviors remains elucidated. Here, we investigated nanomedicinal approach that targets more preferentially microglia and long-term analgesics. Fexofenadine significantly abolished histamine-induced microglial activation. The fexofenadine-encapsulated poly(lactic-co-glycolic acid) nanoparticles (Fexo NPs) injection reduced the pain sensitivity of spinal nerve ligation rats in a dose-dependent manner. This alleviation was sustained for 4 days, whereas the effective period by direct fexofenadine injection was 3 h. Moreover, Fexo NPs inhibited microglial activation, inflammatory signaling, cytokine release, and a macrophage phenotype shift towards the alternative activated state in the spinal cord. These results show that Fexo NPs exhibit drug repositioning promise as a long-term treatment modality for neuropathic pain. Fexofenadine-encapsulated PLGA nanoparticles (Fexo NPs) and negative control nanoparticles (NC NPs) were generated by sonication with the typical double emulsion (W/O/W) method. As a neuropathic pain model, lumbar 5 spinal nerve ligated rats were administered intrathecally into the spinal subarachnoid space with/without fexofenadine alone, NC NPs, and Fexo NPs. Then, the thermal hyperalgesia was assessed as paw withdrawal latency (PWL) by using Hargreaves Apparatus. The results highlighted that fexofenadine-loaded nanoparticles prolong pain relief in SNL rats. Fexo NPs also reduced M1/M2 macrophage ratio and inhibited cytokine release. [Display omitted] [ABSTRACT FROM AUTHOR]

In the covered karst of west-central Florida, USA, sinkholes (sandy collapse conduits) provide locally concentrated recharge to underlying aquifers. For water management, it would be beneficial to understand the rates at which collapse conduits recharge an underlying aquifer. Self-potential (SP) monitoring has promise as a noninvasive, relatively low-cost method for assessing temporal variability in flow. Previous studies suggested that negative SP anomalies over collapse conduits correspond to downward-flowing groundwater; however, before SP surveys can be reliable indicators of conduit flow, SP from ET, soil conductivity changes, redox, electrode effects, and cultural noise must be better understood. A year of continuous SP monitoring with two grids of approximately 15 Pb/PbCl/KCl nonpolarizing electrodes each was combined with high-resolution ground-penetrating radar surveys and intermittent water table monitoring over two small covered-karst conduits in Tampa, Florida, USA. Although variations in SP resulting from changes in cultural noise, soil conductivity, ET, redox, and rainfall were evident, separate and unrelated positive and negative SP anomalies episodically manifested over conduits, which suggested that conduit flow could be dynamic, not static. Three flow regimes in conduits were postulated: conduit permeability higher than in surrounding surficial sediments, conduit permeability lower than in surrounding surface sediments, conduit permeability matched surrounding surface sediments. Numerical steady-state 2D simulations in Comsol created the three postulated flow regimes and revealed that a different SP polarity could result from different rates of flow: positive SP corresponded to higher permeability conduits, negative SP corresponded to lower permeability conduits, no or minimal SP appeared when conduits and surrounding sediments had equal permeability. In these models, downward flow was not responsible for generating negative SP. To assess the hydrology of a conduit, it appears that SP should be monitored continuously. Further monitoring of field sites with hydrologic sensors is needed. [ABSTRACT FROM AUTHOR]

Abstract: Late Neoproterozoic to Cambrian ages have been widely recorded from the Southern Granulite Terrain (SGT) of India and were correlated with global tectono-thermal (Pan-African) events associated with amalgamation of the Gondwana supercontinent. We report results of single zircon dating from a charnockite and a granitic augen–gneiss from the SGT using SHRIMP and evaporation techniques, complemented by zircon Hf isotopic systematics. The SHRIMP data for zircons in the charnockite are spread along a well-defined discordia line suggesting variably strong lead–loss during the late Neoproterozoic Pan-African event. A concordant grain yielded a 207Pb/206Pb age of 1893±13Ma, and the upper intercept of the discordia line for all analyses with Concordia is at 1881±14Ma. The concordant grain age is considered to most closely reflect the time of emplacement of the charnockite protolith. The imprecise lower Concordia intercept at 572±25Ma is likely to reflect Pb-loss during granulite-facies metamorphism. Evaporation of four zircons yielded consistent 207Pb/206Pb isotopic ratios at high evaporation temperatures of ca. 1598°C, suggesting an age of ca. 1450Ma. This date is clearly much younger than the SHRIMP result and suggests that the evaporated grains no longer contained their original, magmatic 207Pb/206Pb ratios but record strong Pb-loss as also shown by the SHRIMP data. Lu–Hf isotopic analysis of ten spots on zircon grains previously analyzed by SHRIMP II yielded strongly negative εHf(t)-values of −6.1 to −9.2 and mean Hf crustal residence ages of 2.95 to 3.14Ga. Eight grains from the augen–gneiss analyzed on SHRIMP II also show variable but considerable Pb-loss. A concordant grain yielded an age of 1557±16Ma, and the other grains define a discordia line with an upper Concordia intercept at 1553±21Ma. Two unzoned grains produced a combined mean 206Pb/238U age of 583±6Ma and reflect the high-grade late Neoproterozoic metamorphic event. A concordant 207Pb/206Pb age of 2043±13Ma was obtained for a xenocryst. Evaporation of five large zircons from this sample yielded a precise mean 207Pb/206Pb age of 1556.0±0.5Ma, identical to the result for the SHRIMP-dated concordant grain. Lu–Hf isotopic analysis of ten spots on zircon grains from where SHRIMP data were gathered yielded strongly negative εHf(t)-values of −6.0 to −17.0 and mean Hf crustal residence ages of 2.68 to 3.37Ga. Our results suggest that not all rocks in the so-called Pan-African domain of southern India are Neoproterozoic in age, and that there could be more Mesoproterozoic to Archaean crust hidden in the “sea” of Neoproterozoic granulites, granitoids and migmatites than so far recognized. The Hf isotopic data reveal both granitoid samples to be derived from crustal melts generated from Archaean continental crust, and the chemistry of these rocks is inherited from their ancient source. We compare the zircon ages with those of similar rocks in the Highland Complex of Sri Lanka and discuss their relevance as vestiges of an older continental terrain incorporated within the late Neoproterozoic–Cambrian collision belt of East Gondwana. In view of rock and age similarities we tentatively suggest links between the Indian Trivandrum and Madurai Blocks and the Sri Lankan Highland and Wanni Complexes. [Copyright &y& Elsevier]

Abstract: We report SHRIMP zircon ages for felsic volcanic rocks of the early Archaean Nondweni greenstone belt (NGB) located in northern KwaZulu-Natal Province, South Africa. The NGB is part of a chain of greenstone belt remnants that occurs south of the well-known Barberton greenstone belt (BGB). Two samples of felsic volcanic rocks of the basal Toggekry Formation yielded zircon ages of ~3.53Ga, whereas significantly younger ages of ~3.41Ga were obtained for two samples of felsic rocks from near the top of the Witkop Formation. The latter date now constrains the age of stromatolite-like structures in cherts associated with the felsic rocks, which probably represent some of the oldest preserved evidence of life on Earth. The zircon ages also indicate that the NGB correlates well chronologically with the BGB and is one of the oldest volcano-sedimentary successions in the southeastern Kaapvaal Craton. Geochemical data for the felsic NGB rocks suggest formation by partial melting or crystal fractionation of a mafic source that was contaminated by older crust, possibly in a back-arc environment. Initial εNd values for NGB rocks range from −1.2 to +0.3 and suggest involvement of pre-greenstone continental crust that was possibly extensive in the southeastern part of the Kaapvaal Craton during Palaeoarchaean times. [Copyright &y& Elsevier]

Abstract: The cause analysis of complex soft terrain collapse and the accordingly reasonable solutions, ensuring the safety of personnel and the environment protection during tunneling are the common concerns in civil and environment engineering. Associated with the soft terrain collapse in the Xinkailing tunnel, after the cause analysis and geological and environmental experts studying together, the reasonable and effective measures have been taken; and the effectiveness of prevention has been evaluated by means of the three dimensional deformation measuring with non-contact total station and the finite element numerical analysis. This research shows that the main causes are the poor geological parameters, the poor discrimination of geological environment and the groundwater erosion, etc. It is the key points to reduce collapse that the good description of tunnel face, timely analyzing and predicting the geological condition at the front of surrounding rock of tunnel face, ensuring accurate judgment of the surrounding rock classification and the meeting of strength requirement of supporting parameters. And it is the effective means that strengthened supporting in collapse impacting area, closing of surrounding rock of collapsed body, enhancing the supporting strength in collapsed area and having it done timely, filling the collapsed cavity. After the treatments,the ultimate arch crown vertical displacement of surrounding rock and primary support in collapsed area is about 17.8mm,the safety factor of primary support structure at side wall is about 3.1, and it meets the specifications. In conclusion, it is proved that the treatments are safe and effective, authentic, offering the reference for alike tunnel design and construction in future. [Copyright &y& Elsevier]

Abstract: In this paper, taking the ENVISAT satellite SAR images in Bam city as an example, the authors construct Digital Elevation Model (DEM) with InSAR technology, and by comparing the InSAR DEM with SRTM-3 DEM they also research the relationship between InSAR DEM''s precision and terrain factors represented by slope and aspect. The results show that the elevation difference mean error between InSAR DEM and SRTM-3 DEM of the experiment area is 12.50 meters, and the precision is reduced with the increase of slope but basically has nothing to do with aspect. In this paper, taking the ENVISAT satellite SAR images in Bam city as an example, the authors construct Digital Elevation Model (DEM) with InSAR technology, and by comparing the InSAR DEM with SRTM-3 DEM they also research the relationship between InSAR DEM''s precision and terrain factors represented by slope and aspect. The results show that the elevation difference mean error between InSAR DEM and SRTM-3 DEM of the experiment area is 12.50 meters, and the precision is reduced with the increase of slope but basically has nothing to do with aspect. [Copyright &y& Elsevier]

Abstract: Although prediction model AERMOD has been widely applied for atmospheric impact assessment in China and abroad, the considerable difficulty of getting the hourly surface meteorological data and upper data in one or more years hinders the development of atmospheric environment assessment in China. By coupling with relevant kernel (AERMOD, AERMAP, BPIPPRM) of AERMOD, AERSCREEN can capture the meteorological conditions and concentration results for the worst case without any input of meteorological data. In this paper, a comparison of atmospheric prediction on the flat terrain between AERMOD and AERSCREEN is made by setting several scenarios in condition of different underlying surfaces and source parameters. Then, a new method of atmospheric impact prediction without meteorological data based on AERSCREEN, as well as suggestions, is put forward in the end of the paper. [Copyright &y& Elsevier]

Abstract: Fire danger rating systems commonly ignore fine scale, topographically-induced weather variations. These variations will likely create heterogeneous, landscape-scale fire danger conditions that have never been examined in detail. We modeled the evolution of fuel moistures and the Energy Release Component (ERC) from the US National Fire Danger Rating System across the 2009 fire season using very high resolution (30m) surface air temperature, humidity and snow ablation date models developed from a network of inexpensive weather sensors. Snow ablation date occurred as much as 28days later on North-facing slopes than on South-facing slopes at upper elevations. South-facing slopes were hotter and drier than North-facing slopes but slope position, in addition to aspect, was also important because nocturnal air temperatures were coolest and humidity was highest in valley bottoms. These factors created heterogeneous fuel moistures and fire danger across the study area. In the late season (August and September), nocturnal cold air drainage and high relative humidity fostered fuel moisture recovery in valley bottoms, where fuel moistures and ERC values were 30% and 45% higher and lower, respectively at peak fire danger (September 29th). Dry fuel moistures and relatively high ERC values persisted on low elevation, South-facing slopes. The driest conditions were observed 100–200m above the valley floor where mid-slope thermal belts frequently developed above areas of cold air pooling. We suggest that a complete understanding of these variations may help improve fire management decision making. [Copyright &y& Elsevier]

This applications paper presents the methods used to create a seamless topobathy digital terrain model (DTM) at 50-foot resolution intended to support hurricanes storm surge modeling in Tampa Bay, Florida. Lidar, bathymetry, and various breakline data were integrated using the Terrain Data Set structure in ArcGIS®. The use of the Terrain Data Set structure allowed for embedding large data sets (such as lidar points) and archiving them after DTM creation while maintaining topographic analysis capabilities. The bathymetric data, natively referenced to Mean Sea Level (MSL), were converted to North American Vertical Datum of 1988 (NAVD88) using an inverse distance weighted average offset from the three nearest NOAA tidal benchmark stations; results of this conversion were within 6.1 centimeters of those produced by NOAA VDatum software in a quality control test area. This methodology can therefore be used in coastal regions of other countries. [ABSTRACT FROM AUTHOR]

The basic block diagrams of proportional navigation are revisited. The effect of initial conditions on the miss distance is studied. Using the important case of multiple targets, two proportional navigation block diagrams are compared. The first, the ideal proportional navigation, applies the true line-of-sight rate, which is calculated by an analytic derivative of the fine-of-sight angle. The block diagram resulting from this guidance loop is minimal. The second applies an approximate derivative of the line-of-sight angle. Because of zero-pole cancellation at the origin, the block diagram resulting from this guidance loop is unobservable with respect to target displacement. The consequence is that for the target-displacement initial condition the two diagrams do not result in the same miss distance. Moreover, several solutions that can resolve the above difficulty are suggested. One of the solutions is to reset the derivative filter with the correct initial conditions. Another solution is to skip the first few samples of the derivative filter right after target separation. [ABSTRACT FROM AUTHOR]

Operational airborne releases of trace quantities of the radioactive noble gas 41Ar from the HIFAR Nuclear Research Reactor located in Sydney, Australia, are valuable for evaluating emergency response models incorporating radiological dispersion. A network of meteorological stations and GR-150 environmental gamma dose detectors are placed in the complex terrain within a 5 km radius of the site. Predictions from the model combination LSMC/RIMPUFF are evaluated using 15 min 41Ar peak observations from the detector network during 2002-2003 under a range of atmospheric stability conditions. Statistical analyses are carried out to compare the results against previous evaluations. [ABSTRACT FROM AUTHOR]

Implementation of the ITU-R P.1546-4 and ITM propagation models for SEAMCAT prepared and developed in the National Institute of Telecommunications Poland is presented. Results of our research encompasses methodology, implementation and verification of plug-ins into the SEAMCAT software are shown. [ABSTRACT FROM AUTHOR]

Abstract: This paper describes a new fast and scalable parallel algorithm to compute global flow accumulation for automatic drainage network extraction in large digital elevation models (DEM for short). Our method uses the D8 model to compute the flow directions for all pixels in the DEM (except NODATA and oceans). A parallel spanning tree algorithm is proposed to compute hierarchical catchment basins to model the flow of water from a sink (local minima) moving on DEM to its outlet (ocean, NODATA, or border of DEM). And finally, based on local flow accumulation and the hierarchical trees between sinks, we determinate entirely the global flow accumulation. From that, the drainage networks of DEM can be extracted. Our method does not need any preprocessing like stream burning on the initial DEM and tends to make the most of incomplete DEMs. Our algorithms are entirely parallel. Efficiency and scalability have been tested on different large DEMs. [Copyright &y& Elsevier]

Abstract: We propose a new method to detect ridges from digital elevation map (DEM) data. We call it “the steepest ascent method” which is based on steepest ascent lines obtained by selecting the maximum inclined direction from eight neighbors. Then ridge lines are extracted by their steepest ascent lines on a surface. In this paper it is shown that our method is able to detect ridge lines sharply. Besides we claim that our algorithm is simple and suitable for huge area such as the entire area of Japan. Finally, we give the ridge detected terrain map of the entire area of Japan and Korea by applying “the steepest ascent method”. [Copyright &y& Elsevier]

This paper introduces an automated method for building height recovery through the integration of high-resolution satellite images and digital vector maps. A crosscorrelation matching method along the vertical line locus on the Ikonos images was deployed to recover building heights. The rational function models composed of rational polynomial coefficients were utilized to create a stereopair of the epipolar resampled Ikonos images. Building footprints from the digital maps were used for locating the vertical guideline along the building edges. The digital terrain model (DTM) was generated from the contour layer in the digital maps. The terrain height derived from the DTM at each foot of the buildings was used as the starting location for image matching. At a preset incremental value of height along the vertical guidelines derived from vertical line loci, an evaluation process that is based on the cross-correlation matching of the images was carried out to test if the top of the building has reached where maximum correlation occurs. The accuracy of the reconstructed buildings was evaluated by the comparison with manually digitized 3D building data derived from aerial photographs. [ABSTRACT FROM AUTHOR]