Physical Sciences and Mathematics Commons^™

Bothriochloa Pertusa- A Useful Grazing-Tolerant Grass For The Seasonally Dry Tropics?, R J. Jones, A Kerr

IGC Proceedings (1977-2023)

Data from 2 grazing experiments, small-plot studies, and a vegetation and soil survey showed that Bothriochloa pertusa increased relative to native tufted perennial grasses under heavy grazing pressure and was adapted to a wide range of soils in the 500-1000 mm zone of northern Australia. Ability to grow on low-P soils, lower relative palatability, strong stoloniferous development and good seed production, were features of its success. Annual steer gains on 8. pertusa pastures were similar to those on native pastures, with no species x stocking rate interaction. Steer gains on B. pertusa-Vernno stylo pastures were lower than on Urochloa …

Sustainability Of Sown Pastures In The Tropics And Subtropics, Jose M. Toledo, Daniel Formoso

IGC Proceedings (1977-2023)

Sown pastures in the tropics and subtropics are important components of production systems. Their role in and contribution to land productivity and economic development are well understood; however, their roles in sustainability and environmental protection are rather misunderstood and little known. The main constraints to sustainability of sown pastures fall into two categories: physical, biological and technical constraints include soil and climatic limitations, lack of adaptation of plants to physical and biotic stress and the limitations of farmers or ranchers to apply technology; socioeconomic factors include political instability, poorness of society and the market forces for land, inputs and products. …

Stability In Rangelands: Ecology And Economics, B H. Walker

IGC Proceedings (1977-2023)

Examples of changes in rangelands are presented relating to changes in livestock number, plant species. composition and soil changes (associated with changes in production), The mechanisms Involved are described, using examples, under the headings: event-driven change, threshold effects, non-linear and hysteresis effects, effects of spatial variation, significance of temporal variation, and interactive effects. The implications for management are presented in the form of a proposed optimal control model which maximises a complex function of welfnre based on long-term net economic benefit, in which stocking rate effects on the state of the rangeland feed back on to economic return.

Diffendal Receives Wisherd Award For University Service, Ronica Stromberg

Robert F. Diffendal, Jr., Publications

Even though he’s retired, Robert Diffendal seems to be working everywhere.

The professor emeritus in the School of Natural Resources retains offices in three buildings. He reports to work at the Center for Great Plains Studies five days a week for about four hours a day. His list of volunteer activities around the state goes on and on, affecting, by his count, 21,088 people since 2003, when he stepped away from full-time faculty work. He capped 2024 at Nebraska Innovation Campus, where he received the Wisherd Award for Outstanding Service to the University of Nebraska–Lincoln.

Chosen by the Emeriti and …

01.21.2025 Ored Connect, Liz Williamson

ORED Newsletter

SmartTech MS Advanced Manufacturing Prize

Mileage Rate Increases

Meth Mortality Rate Increases

Site U1554, R. E. Parnell-Turner, A. Briais, L. J. Levay, Y. Cui, A. Di Chiara, J. P. Dodd, T. Dunkley Jones, D. Dwyer, D. E. Eason, S. A. Friedman, S. R. Hemming, K. Hochmuth, H. Ibrahim, C. Jasper, B. T. Karatsolis, S. Lee, D. E. Leblanc, M. R. Lindsay, D. D. Mcnamara, S. E. Modestou, B. Murton, S. Oconnell, G. T. Pasquet, P. N. Pearson, S. P. Qian, Y. Rosenthal, S. Satolli, M. Sinnesael, T. Suzuki, T. Thulasi Doss, N. J. White, T. Wu

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

No abstract provided.

Site U1555, A. Briais, R. E. Parnell-Turner, L. J. Levay, Y. Cui, A. Di Chiara, J. P. Dodd, T. Dunkley Jones, D. Dwyer, D. E. Eason, S. A. Friedman, S. R. Hemming, K. Hochmuth, H. Ibrahim, C. Jasper, B. T. Karatsolis, S. Lee, D. E. Leblanc, M. R. Lindsay, D. D. Mcnamara, S. E. Modestou, B. Murton, S. Oconnell, G. T. Pasquet, P. N. Pearson, S. P. Qian, Y. Rosenthal, S. Satolli, M. Sinnesael, T. Suzuki, T. Thulasi Doss, N. J. White, T. Wu

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

No abstract provided.

Exhibit 2 “Basement Iswp” 1232 E. Second St. Butte, Mt 59701 January 21, 2025 Database Residential Identifier: R-04389, Butte-Silver Bow Department Of Reclamation And Environmental Services

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Expedition 395 Summary, R. E. Parnell-Turner, A. Briais, L. J. Levay, Y. Cui, A. Di Chiara, J. P. Dodd, T. Dunkley Jones, D. Dwyer, D. E. Eason, S. A. Friedman, S. R. Hemming, K. Hochmuth, H. Ibrahim, C. Jasper, B. T. Karatsolis, S. Lee, D. E. Leblanc, M. R. Lindsay, D. D. Mcnamara, S. E. Modestou, B. Murton, S. Oconnell, G. T. Pasquet, P. N. Pearson, S. P. Qian, Y. Rosenthal, S. Satolli, M. Sinnesael, T. Suzuki, T. Thulasi Doss, N. J. White, T. Wu

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The intersection between the Mid-Atlantic Ridge and Iceland hotspot provides a natural laboratory where the composition and dynamics of Earth's upper mantle can be observed. Plume-ridge interaction drives variations in the melting regime, which result in a range of crustal types, including a series of V-shaped ridges (VSRs) and V-shaped troughs (VSTs) located south of Iceland. Mantle upwelling beneath Iceland dynamically supports regional bathymetry, and its variations may lead to changes in the height of oceanic gateways, which in turn control the flow of deep water on geologic timescales. Expeditions 384, 395C, and 395 recovered extensive successions of basaltic crust …

Sequential Convex Programming Using Safe Flight Corridor For Trajectory Planning Of Uavs, Zhu Wang, Zhenpeng Zhang, Mengtong Zhang, Guangtong Xu

Journal of System Simulation

Abstract: To address the issues of sensitivity to initial values and weak convergence of sequential convex programming(SCP) based time-optimal trajectory planning for UAVs, a SCP method using safety flight corridor, denoted as SFC-SCP(safe flight corridor-sequential convex programming) is proposed. According to the obstacle avoidance path obtained from the front-end path planning, a safe flight corridor is constructed by forming a convex polygon safe flight area without obstacles for each trajectory point. The non-convex obstacle avoidance constraint is converted into linear inequality constraints to improve convergence ability. The rear-end SCP method is used to transform the nonlinear trajectory optimization problem under …

Water Quality Contributions Of Selected Buffalo River Headwaters In Searcy County, Arkansas, 2019–2023, Patrick Michael Dyer

Student Theses and Dissertations

Regulated by the National Park Service since 1972, the Buffalo River faces nitrogen, phosphorous, sediment, and fecal coliform contamination. Research assessing tributary water quality began with collecting water samples weekly from November 2019 until January 2023 (n = 156) near Tyler Bend Campgrounds. Pairwise analysis measured minimal water quality change from upstream to downstream on four headwater creeks. Data revealed that Tomahawk Creek’s fecal coliform bacteria were elevated above background levels, frequently exceeding state standards. National Land Cover Dataset class data were extracted to index land use at different scales. Simple linear regression, stepwise multiple linear regression, and a random …

Research And Realization Of Immersive Skeleton Simulation System, Zining Wang, Shijiang Luo, Weiya Chen, Hanbin Luo

Journal of System Simulation

Abstract: Skeleton, as one of the sliding sports in Winter Olympic Games, has the characteristics of high speed, complexity and danger. In order to reduce the risk of accidents during sliding, a series of immersive skeleton simulation system is constructed utilizing virtual reality. Based on the point cloud data obtained by laser scanning, the existing track is modeled to build a virtual track stadium and skeleton sliding model in Unreal Engine 4. The data collected by motion capture devices is employed to estimate the centroid of the person and enable glide control input. The simulated skeleton posture is captured and …

Research On Modeling And Simulation Of Collective Mechanical Props Performance Behavior, Lian He, Kexiang Huang, Dapeng Yan, Ruida Tang, Gangyi Ding

Journal of System Simulation

Abstract: In stage performances, the increasing number of mechanical props poses significant challenges to their control and design. Each creative modification requires a complete rehearsal, resulting in low efficiency and sensitivity to creative changes. To address these issues, a model for the collective performance behavior of mechanical props is proposed. It utilizes centroid growth and 3D linear interpolation to generate spatial states and optimizes them in the temporal dimension using gradient descent. Through the construction of 3D simulation experiments, the planning and optimization of collective mechanical prop performance behavior in the model are analyzed. Similarity evaluation is used to compare …

Task Reallocation Method For Unmanned Swarm Under Adversarial Conditions, Lun Zhang, Mei Yang, Tuo Zhao, Shuiku Zhang, Jian Huang

Journal of System Simulation

Abstract: Heterogeneous unmanned swarms have important potential applications in future wars. However, during the high-intensity confrontation in the battlefield, how to efficiently and quickly redistribute the tasks carried by the damaged agents so that the swarms could successfully complete the mission is a difficult problem that must be addressed in the combat application of unmanned swarms. This paper proposes a task reallocation method named improved CNP-HA (contract net protocol-Hungarian algorithm). Through the allocation mechanism and the bidding mechanism, the method realizes the task reallocation of damaged agents with lower communication cost and faster speed comparing with baseline methods. In the …

Multi-Uav Deployment And Collaborative Offloading For Large-Scale Iot Systems, Zhiqin Huang, Tianying Lu, Zheyi Chen

Journal of System Simulation

Abstract: In large-scale internet-of-things (IoT) systems, unmanned aerial vehicles (UAV) enabled mobile edge computing (MEC) can alleviate the performance constraints on end IoT devices. However, due to the uneven distribution of IoT devices and inefficient problem-solving, how to efficiently perform computation offloading in large-scale IoT systems is a major challenge. Existing solutions generally cannot fit into dynamic multi-UAV scenarios, causing inefficient resource utilization and excessive response delay. To address these important challenges, this paper proposes a novel multi-UAV deployment and collaborative offloading (MUCO) method for large-scale IoT systems. A UAV deployment scheme based on constrained K-Means clustering is designed to …

Moving Target Velocity Measurement Method Based On Multi-View Observation Optimization Of Uav Image, Yuxin Wu, Zhilong Zhang, Aoxu Liu, Jiangwei Zou, Chuwei Li

Journal of System Simulation

Abstract: Measuring the position and velocity of moving targets is an important requirement for drone video analysis. In this paper, a moving target localization and velocity estimation algorithm based on least square optimization of UAV multi-view observation images is proposed: the video and corresponding pose parameters obtained by the airborne optoelectronic system are used to establish a line-of-sight model at multiple observation times, it is unified to the WGS-84 coordinate system by coordinate transformation, the position and velocity of the moving target are estimated based on the least squares algorithm. This algorithm does not require laser ranging information between the …

Decision Modeling And Solution Based On Game Adversarial Complex Systems, Jiachen Jiang, Zhengxuan Jia, Zhao Xu, Tingyu Lin, Pengpeng Zhao, Yiming Ou

Journal of System Simulation

Abstract: In view of the complex situation of the current game which will be large-scale, high-intensity, not omniscient, and strong confrontation, and in response to the lack of flexibility and long iteration cycles in traditional game decision-making, the model of the unmanned complex game system is built according to the background of the unmanned red and blue game. Based on deep reinforcement learning technology, intelligent decision-making algorithms are studied in the background of unmanned red and blue games. With the help of deep neural networks and Bellman's optimal principle, the search of the huge solution space is more efficient, and …

Dynamic Scene Point Cloud Mapping Method Based On Lidar-Imu, Weigang Li, Lei Gan, Yongqiang Wang

Journal of System Simulation

Abstract: In order to address the issue of decreased mapping accuracy and precision caused by dynamic object interference during the construction of point cloud maps in dynamic scenarios such as urban roads, this study proposes a method for building dynamic scene point cloud maps based on LiDAR and inertial measurement unit (IMU). The method incorporates several key steps. An index-based Octree voxel structure is utilized to enhance the incremental update and nearest neighbor search efficiency of the local perception map (LP-Map). The point cloud is processed using ground segmentation, clustering, and dynamic score calculation methods to enable real-time identification of …

A Visual Servo Precision Assembly Method For Riveting Parts Based On Adaptive Extended Kalman Filtering, Zonggang Li, Yanbo Li, Jianjun Jiao, Yajiang Du

Journal of System Simulation

Abstract: Aiming at the problems of multiple peg-in-hole riveting parts in industrial production due to the large number of rivets, small gap between rivets and rivet holes, and irregular rivet distribution, resulting in complex assembly process constraints, high assembly accuracy requirements, and difficulty in realizing intelligent riveting process to improve assembly efficiency, a visual servo accurate assembly method of riveting parts based on adaptive extended Kalman filter is proposed. In order to realize the high-precision positioning of riveted parts assembly, on the basis of the traditional extended Kalman filtering, an adaptive noise estimator is introduced to eliminate the influence of …

Performance Evaluation Technology For Low Earth Orbit Satellite Internet, Xiaofeng Wang, Yi Zhang, Guoxiu Zhang

Journal of System Simulation

Abstract: Performance evaluation can provide strong support for new technology verification of low earth orbit(LEO) satellite internet. Aiming at the characteristics of flexible networking and large spacetime scale of satellite internet, a performance evaluation architecture of satellite internet is designed. Aiming at the characteristics of various performance elements, a performance evaluation index system is designed under the premise of multi-dimensional comprehensive consideration. Aiming at the problem of frequent switching of satellite-ground links caused by high-speed movement, an algorithm for satelliteground link switching is proposed, which provides support for subsequent collection work. Aiming at the multi-dimensional problem of indicators, a multi-mode …

Simulation Research On Multi-Aircraft Conflict Resolution Based On Improved Chaotic Ant Colony Algorithm, Liang Tong, Jie Yang, Xusheng Gan, Di Shen, Wenda Yang, Daxiong Chen

Journal of System Simulation

Abstract: A chaotic ant colony algorithm based on dynamic volatility factor is proposed to solve the problem of multi-aircraft conflict resolution during free flight of fighter jets. The mathematical modelling is conducted on the conflict resolution problem of multiple fighter jets in the air. Based on the performance characteristics of fighter jets, fighter protection zone models, flight conflict models, and resolution models are established respectively. The chaotic ant colony algorithm is improved by using Logistic mapping and Henon mapping to optimize the pheromone update formula in the ant colony algorithm, and setting a dynamic factor for the pheromone volatilization factor …

Research On Mixed-Model Assembly Line Balancing Optimization Based On Hybrid Genetic Tabu Search Algorithm, Ke Wang, Sijia Guan, Xiyan Yin, Xixing Li, Hongtao Tang

Journal of System Simulation

Abstract: Aiming at the problem of unbalanced running load caused by idle or blocked workstations in the assembly line of mixed-flow hydraulic pump, a hybrid genetic tabu search algorithm solution and computer simulation verification method are proposed. A hybrid genetic tabu search algorithm with strong local search capability is designed with the optimization objectives of minimizing the production beats of the mixed-flow assembly line, the operational loads distributed among different workstations and the operational load smoothing indices of different products within the same workstation. The algorithm incorporates multi-fragment crossover and fragmentation of feasible solutions through Hamming distance mutation operations. The …

Research And Implementation Of Digital Twin System For Mine Drainage Monitoring, Qinghui Wu, Yaqing Bao, Zhongxin Zhao, Xu Huang, Yuchen Wei

Journal of System Simulation

Abstract: The conventional mine drainage monitoring system faces problems such as poor visualization, insufficient linkage, and monotonous real-time monitoring methods for mine drainage in dynamic environments. Combining digital twin technology, a digital twin system for mine drainage monitoring has been developed. Through the construction of digital space, virtual real interaction layer structure framework, and three-dimensional visualization system data architecture, combined with fluid mechanics, using Unity3D development engine and five dimensional model ideas, a three-dimensional visualization system architecture for mine drainage is constructed, achieving various application functions such as real-time monitoring, fault warning, and virtual real mixed control. The feasibility of …

Global Selection And Local Differentiation Fusion For Vehicle Re-Identification, Shengjun Xu, Mengqian Zhang, Bohan Zhan, Guanghui Liu, Yuebo Meng

Journal of System Simulation

Abstract: To address the interference issues of different perspectives, complex backgrounds, and lighting intensity in vehicle re-identification caused by cross lens multi view differences, a vehicle reidentification network integrating global selection and local differentiation is proposed. Based on Resnet50 backbone network, a three-branch complementary network integrating global and local features is designed. The global branch is used to learn overall appearance information of the vehicle, while the local branch captures differential details of the vehicle. Based on attention mechanism, a context feature selection module (CFSM) is proposed to effectively separate vehicle information from complex background information, and a detail feature …

Vehicle Routing Problem With Drones Considering Zoned Distribution Of Epidemic Prevention Materials, Huawei Ma, Boying Yan

Journal of System Simulation

Abstract: To address the shortcomings of current contactless delivery methods in the collaborative distribution of epidemic prevention supplies, we introduce a specialized model called the vehicle routing problem with drones considering zoned distribution (VRPD-ZD). In order to solve the problem, a linear programming model is established with the shortest delivery time as the optimization objective, and a two-stage heuristic algorithm is proposed. The initial solution is generated by greedy algorithm in the first stage. In the second stage, we develop a Tabu search algorithm with genetic algorithm (TSGA) hybrid. This enhanced algorithm integrates a taboo list and employs advanced chromosome …

Cooperative Control Method Of Mixed Traffic At Signalized Intersection, Qiushi Huang, Yanyang Wang, Changliang Wu, Junfu Huang, Shenggen Zhang, Haoxuan Luo

Journal of System Simulation

Abstract: A hierarchical decoupling cooperative control method for signal light mixed traffic platoon is designed with the goal of improving the traffic environment at signalized intersections. In the research of upper layer signal control, a calculation model for vehicle delay time at intersections is selected, with the goal of minimizing the average delay time of vehicles. A genetic algorithm based upper layer control strategy for intersection signal lights is proposed and verified; in the research of lower layer mixed platoon control, a "1+N" form is used to establish a dynamic model of the mixed platoon. A vehicle energy consumption model …

Path Planning Of Mobile Robot Based On The Integration Of Multi-Scale A* And Optimized Dwa Algorithm, Jianmin Xu, Lei Song, Dongdong Deng, Yaoruo Chen, Wei Yang

Journal of System Simulation

Abstract: In order to solve the problems of sharply increasing computational and time costs, as well as poor flexibility of the traditional A* algorithm and dynamic window approach (DWA) in the face of largescale complex environmental path planning, a fusion algorithm based on the A* algorithm of the multiscale map approach(MMA) and the improved DWA algorithm is proposed. A multi-scale map set is established and an obstacle proportion factor is added to the heuristic function of the A* algorithm. The A* algorithm is used to calculate the optimal path on the coarse-scale map, and the optimal path is mapped onto …

Driverless Vehicles Distribution Problem In Communities In Cooperation Of Storage Points, Xiaolong Diao

Journal of System Simulation

Abstract: With the development of smart communities, the distribution of driverless vehicles in communities has become a focus of government, operators and researchers. The joint cooperation of storage points in communities is designed to balance the the distribution of each storage point and avoid the high input cost of driverless vehicles, which means that driverless vehicles can travel between different storage points. The driverless vehicle distribution problem proposed in this paper includes the unloading subproblem and the driverless vehicle scheduling subproblem. For the unloading subproblem, the unloading scheme of vehicles at storage points is optimized with the aim of minimizing …

Novel Multi-Gait Strategy For Stable And Efficient Quadruped Robot Locomotion, Daoxun Zhang, Xieyuanli Chen, Zhengyu Zhong, Ming Xu, Zhiqiang Zheng, Huimin Lu

Journal of System Simulation

Abstract: Inspired by the natural gait transition mechanism of quadruped animals, a multi-gait motion strategy is proposed to realize the stable and efficient motion of quadruped robots on different terrains in response to the trade-off between motion energy efficiency and motion stability. The gait is defined based on the duty cycle parameters and phase bias to form the switching basis. Secondly, the affine transformation of gait parameters and the finite state machine are introduced to establish the switching sequence, which realizes the timely gait switching. The speed-gait mapping is designed based on the cost of transport (CoT) and the stability …

Design Of Robust Behavior Tree Control Architecture For Agents In Dynamic Task Environment, Qiwei Wang, Qi Zhang, Shuo Yang, Yong Peng

Journal of System Simulation

Abstract: In recent years, the environment in which agents perform tasks has become more open and dynamic, which puts forward higher requirements for the robustness of task planning and behavior scheduling of agents. As a classic behavior control architecture, behavior tree has the characteristics of modularity, behavior parameterization, and structure of both plan representation and reaction, which can effectively support the behavior representation, decision making and scheduling of agents. Based on the hybrid behavior strategy , this paper proposes a robust behavior tree control architecture for dynamic task environment to realize the prudent decision-making and reactive control of agents. The …