163 research outputs found
Lifecycle Cost Optimization for Electric Bus Systems With Different Charging Methods: Collaborative Optimization of Infrastructure Procurement and Fleet Scheduling
Battery electric buses (BEBs) have been regarded as effective options for sustainable mobility while their promotion is highly affected by the total cost associated with their entire life cycle from the perspective of urban transit agencies. In this research, we develop a collaborative optimization model for the lifecycle cost of BEB system, considering both overnight and opportunity charging methods. This model aims to jointly optimize the initial capital cost and use-phase operating cost by synchronously planning the infrastructure procurement and fleet scheduling. In particular, several practical factors, such as charging pattern effect, battery downsizing benefits, and time-of-use dynamic electricity price, are considered to improve the applicability of the model. A hybrid heuristic based on the tabu search and immune genetic algorithm is customized to effectively solve the model that is reformulated as the bi-level optimization problem. A numerical case study is presented to demonstrate the model and solution method. The results indicate that the proposed optimization model can help to reduce the lifecycle cost by 7.77% and 6.64% for overnight and opportunity charging systems, respectively, compared to the conventional management strategy. Additionally, a series of simulations for sensitivity analysis are conducted to further evaluate the key parameters and compare their respective life cycle performance. The policy implications for BEB promotion are also discussed
3,3-Dimethyl-1-[5-(1H-1,2,4-triazol-1-ylmethyl)-1,3,4-thiadiazol-2-ylsulfanyl]butan-2-one
In the molecule of the title compound, C11H15N5OS2, the thiadiazole and triazole rings are not coplanar, the dihedral angle formed by their mean planes being 59.9 (2)°. The exocyclic S atom, and the methylene, carbonyl, tert-butyl and one methyl carbon form an approximately planar zigzag chain, which makes a dihedral angle of 74.6 (1)° with the thiadiazole ring
Neural Free-Viewpoint Relighting for Glossy Indirect Illumination
Precomputed Radiance Transfer (PRT) remains an attractive solution for
real-time rendering of complex light transport effects such as glossy global
illumination. After precomputation, we can relight the scene with new
environment maps while changing viewpoint in real-time. However, practical PRT
methods are usually limited to low-frequency spherical harmonic lighting.
All-frequency techniques using wavelets are promising but have so far had
little practical impact. The curse of dimensionality and much higher data
requirements have typically limited them to relighting with fixed view or only
direct lighting with triple product integrals. In this paper, we demonstrate a
hybrid neural-wavelet PRT solution to high-frequency indirect illumination,
including glossy reflection, for relighting with changing view. Specifically,
we seek to represent the light transport function in the Haar wavelet basis.
For global illumination, we learn the wavelet transport using a small
multi-layer perceptron (MLP) applied to a feature field as a function of
spatial location and wavelet index, with reflected direction and material
parameters being other MLP inputs. We optimize/learn the feature field
(compactly represented by a tensor decomposition) and MLP parameters from
multiple images of the scene under different lighting and viewing conditions.
We demonstrate real-time (512 x 512 at 24 FPS, 800 x 600 at 13 FPS) precomputed
rendering of challenging scenes involving view-dependent reflections and even
caustics.Comment: 13 pages, 9 figures, to appear in cgf proceedings of egsr 202
Physically-Based Editing of Indoor Scene Lighting from a Single Image
We present a method to edit complex indoor lighting from a single image with
its predicted depth and light source segmentation masks. This is an extremely
challenging problem that requires modeling complex light transport, and
disentangling HDR lighting from material and geometry with only a partial LDR
observation of the scene. We tackle this problem using two novel components: 1)
a holistic scene reconstruction method that estimates scene reflectance and
parametric 3D lighting, and 2) a neural rendering framework that re-renders the
scene from our predictions. We use physically-based indoor light
representations that allow for intuitive editing, and infer both visible and
invisible light sources. Our neural rendering framework combines
physically-based direct illumination and shadow rendering with deep networks to
approximate global illumination. It can capture challenging lighting effects,
such as soft shadows, directional lighting, specular materials, and
interreflections. Previous single image inverse rendering methods usually
entangle scene lighting and geometry and only support applications like object
insertion. Instead, by combining parametric 3D lighting estimation with neural
scene rendering, we demonstrate the first automatic method to achieve full
scene relighting, including light source insertion, removal, and replacement,
from a single image. All source code and data will be publicly released
2-(1H-Benzotriazol-1-yl)-1-(4-bromobenzoyl)ethyl 4-methylbenzoate
In the molecule of the title compound, C23H18BrN3O3, the benzotriazole mean plane makes dihedral angles of 1.26 (1) and 87.39 (1)° with the tolyl and bromophenyl benzene rings, respectively, and the dihedral angle between the benzene rings is 87.27 (1)°. In the crystal structure, molecules are linked into chains along the a axis by C—H⋯O intermolecular hydrogen bonds. The structure is further stabilized by C—H⋯π and π–π interactions, with a distance of 3.700 (1) Å between the centroids of the bromophenyl and benzotriazole benzene rings related by symmetry code (x, −1 + y, z)
Electric Vehicle Routing Problem with Charging Time and Variable Travel Time
An electric vehicle routing problem with charging time and variable travel time is developed to address some operational issues such as range limitation and charging demand. The model is solved by using genetic algorithm to obtain the routes, the vehicle departure time at the depot, and the charging plan. Meanwhile, a dynamic Dijkstra algorithm is applied to find the shortest path between any two adjacent nodes along the routes. To prevent the depletion of all battery power and ensure safe operation in transit, electric vehicles with insufficient battery power can be repeatedly recharged at charging stations. The fluctuations in travel time are implemented to reflect a dynamic traffic environment. In conclusion, a large and realistic case study with a road network in the Beijing urban area is conducted to evaluate the model performance and the solution technology and analyze the results
DMV3D: Denoising Multi-View Diffusion using 3D Large Reconstruction Model
We propose \textbf{DMV3D}, a novel 3D generation approach that uses a
transformer-based 3D large reconstruction model to denoise multi-view
diffusion. Our reconstruction model incorporates a triplane NeRF representation
and can denoise noisy multi-view images via NeRF reconstruction and rendering,
achieving single-stage 3D generation in 30s on single A100 GPU. We train
\textbf{DMV3D} on large-scale multi-view image datasets of highly diverse
objects using only image reconstruction losses, without accessing 3D assets. We
demonstrate state-of-the-art results for the single-image reconstruction
problem where probabilistic modeling of unseen object parts is required for
generating diverse reconstructions with sharp textures. We also show
high-quality text-to-3D generation results outperforming previous 3D diffusion
models. Our project website is at: https://justimyhxu.github.io/projects/dmv3d/ .Comment: Project Page: https://justimyhxu.github.io/projects/dmv3d
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