23,364 research outputs found
ECONOMIC IMPACTS OF EPA'S MANURE APPLICATION REGULATIONS ON DAIRY FARMS IN THE SOUTHWEST REGION
We estimate that EPA's CAFO final rule on manure application would have different impacts on dairy farms in the region, assuming that the farms would maintain the same herd size and same crop production practices. Some farms in the region would be able to comply it on their current land base, but other would need to lease additional land for land application of manure. Less than 30 percent of those affected farms would have a lower farm income. Most of these affected farms could have no income reduction or a higher income as a result of reduced feed cost from expanding homegrown feed production.Environmental Economics and Policy,
Simultaneous Localization and Mapping (SLAM) on NAO
Simultaneous Localization and Mapping (SLAM) is a navigation and mapping method used by autonomous robots and moving vehicles. SLAM is mainly concerned with the problem of building a map in an unknown environment and concurrently navigating through the environment using the map. Localization is of utmost importance to allow the robot to keep track of its position with respect to the environment and the common use of odometry proves to be unreliable. SLAM has been proposed as a solution by previous research to provide more accurate localization and mapping on robots. This project involves the implementation of the SLAM algorithm in the humanoid robot NAO by Aldebaran Robotics. The SLAM technique will be implemented using vision from the single camera attached to the robot to map and localize the position of NAO in the environment. The result details the attempt to implement specifically the chosen algorithm, 1-Point RANSAC Inverse Depth EKF Monocular SLAM by Dr Javier Civera on the robot NAO. The algorithm is shown to perform well for smooth motions but on the humanoid NAO, the sudden changes in motion produces undesirable results.This study on SLAM will be useful as this technique can be widely used to allow mobile robots to map and navigate in areas which are deemed unsafe for humans
S&Reg: End-to-End Learning-Based Model for Multi-Goal Path Planning Problem
In this paper, we propose a novel end-to-end approach for solving the
multi-goal path planning problem in obstacle environments. Our proposed model,
called S&Reg, integrates multi-task learning networks with a TSP solver and a
path planner to quickly compute a closed and feasible path visiting all goals.
Specifically, the model first predicts promising regions that potentially
contain the optimal paths connecting two goals as a segmentation task.
Simultaneously, estimations for pairwise distances between goals are conducted
as a regression task by the neural networks, while the results construct a
symmetric weight matrix for the TSP solver. Leveraging the TSP result, the path
planner efficiently explores feasible paths guided by promising regions. We
extensively evaluate the S&Reg model through simulations and compare it with
the other sampling-based algorithms. The results demonstrate that our proposed
model achieves superior performance in respect of computation time and solution
cost, making it an effective solution for multi-goal path planning in obstacle
environments. The proposed approach has the potential to be extended to other
sampling-based algorithms for multi-goal path planning.Comment: 7 paegs, 12 figures. Accepted at IEEE International Conference on
Robot and Human Interactive Communication (ROMAN), 202
Simultaneous Localization and Mapping (SLAM) on NAO
Simultaneous Localization and Mapping (SLAM) is a navigation and mapping method used by autonomous robots and moving vehicles. SLAM is mainly concerned with the problem of building a map in an unknown environment and concurrently navigating through the environment using the map. Localization is of utmost importance to allow the robot to keep track of its position with respect to the environment and the common use of odometry proves to be unreliable. SLAM has been proposed as a solution by previous research to provide more accurate localization and mapping on robots. This project involves the implementation of the SLAM algorithm in the humanoid robot NAO by Aldebaran Robotics. The SLAM technique will be implemented using vision from the single camera attached to the robot to map and localize the position of NAO in the environment. The result details the attempt to implement specifically the chosen algorithm, 1-Point RANSAC Inverse Depth EKF Monocular SLAM by Dr Javier Civera on the robot NAO. The algorithm is shown to perform well for smooth motions but on the humanoid NAO, the sudden changes in motion produces undesirable results.This study on SLAM will be useful as this technique can be widely used to allow mobile robots to map and navigate in areas which are deemed unsafe for humans
Perovskite-polymer composite cross-linker approach for highly-stable and efficient perovskite solar cells.
Manipulation of grain boundaries in polycrystalline perovskite is an essential consideration for both the optoelectronic properties and environmental stability of solar cells as the solution-processing of perovskite films inevitably introduces many defects at grain boundaries. Though small molecule-based additives have proven to be effective defect passivating agents, their high volatility and diffusivity cannot render perovskite films robust enough against harsh environments. Here we suggest design rules for effective molecules by considering their molecular structure. From these, we introduce a strategy to form macromolecular intermediate phases using long chain polymers, which leads to the formation of a polymer-perovskite composite cross-linker. The cross-linker functions to bridge the perovskite grains, minimizing grain-to-grain electrical decoupling and yielding excellent environmental stability against moisture, light, and heat, which has not been attainable with small molecule defect passivating agents. Consequently, all photovoltaic parameters are significantly enhanced in the solar cells and the devices also show excellent stability
Neural-Network-Driven Method for Optimal Path Planning via High-Accuracy Region Prediction
Sampling-based path planning algorithms suffer from heavy reliance on uniform
sampling, which accounts for unreliable and time-consuming performance,
especially in complex environments. Recently, neural-network-driven methods
predict regions as sampling domains to realize a non-uniform sampling and
reduce calculation time. However, the accuracy of region prediction hinders
further improvement. We propose a sampling-based algorithm, abbreviated to
Region Prediction Neural Network RRT* (RPNN-RRT*), to rapidly obtain the
optimal path based on a high-accuracy region prediction. First, we implement a
region prediction neural network (RPNN), to predict accurate regions for the
RPNN-RRT*. A full-layer channel-wise attention module is employed to enhance
the feature fusion in the concatenation between the encoder and decoder.
Moreover, a three-level hierarchy loss is designed to learn the pixel-wise,
map-wise, and patch-wise features. A dataset, named Complex Environment Motion
Planning, is established to test the performance in complex environments.
Ablation studies and test results show that a high accuracy of 89.13% is
achieved by the RPNN for region prediction, compared with other region
prediction models. In addition, the RPNN-RRT* performs in different complex
scenarios, demonstrating significant and reliable superiority in terms of the
calculation time, sampling efficiency, and success rate for optimal path
planning.Comment: 9 pages, 8 figure
PKE-RRT: Efficient Multi-Goal Path Finding Algorithm Driven by Multi-Task Learning Model
Multi-goal path finding (MGPF) aims to find a closed and collision-free path
to visit a sequence of goals orderly. As a physical travelling salesman
problem, an undirected complete graph with accurate weights is crucial for
determining the visiting order. Lack of prior knowledge of local paths between
vertices poses challenges in meeting the optimality and efficiency requirements
of algorithms. In this study, a multi-task learning model designated Prior
Knowledge Extraction (PKE), is designed to estimate the local path length
between pairwise vertices as the weights of the graph. Simultaneously, a
promising region and a guideline are predicted as heuristics for the
path-finding process. Utilizing the outputs of the PKE model, a variant of
Rapidly-exploring Random Tree (RRT) is proposed known as PKE-RRT. It
effectively tackles the MGPF problem by a local planner incorporating a
prioritized visiting order, which is obtained from the complete graph.
Furthermore, the predicted region and guideline facilitate efficient
exploration of the tree structure, enabling the algorithm to rapidly provide a
sub-optimal solution. Extensive numerical experiments demonstrate the
outstanding performance of the PKE-RRT for the MGPF problem with a different
number of goals, in terms of calculation time, path cost, sample number, and
success rate.Comment: 9 pages, 12 figure
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