Single Image Reflection Separation via Component Synergy

The reflection superposition phenomenon is complex and widely distributed in the real world, which derives various simplified linear and nonlinear formulations of the problem. In this paper, based on the investigation of the weaknesses of existing models, we propose a more general form of the superposition model by introducing a learnable residue term, which can effectively capture residual information during decomposition, guiding the separated layers to be complete. In order to fully capitalize on its advantages, we further design the network structure elaborately, including a novel dual-stream interaction mechanism and a powerful decomposition network with a semantic pyramid encoder. Extensive experiments and ablation studies are conducted to verify our superiority over state-of-the-art approaches on multiple real-world benchmark datasets. Our code is publicly available at https://github.com/mingcv/DSRNet.Comment: Accepted to ICCV 202

Electronic landscape of the P-cluster of nitrogenase as revealed through many-electron quantum wavefunctions

The electronic structure of the nitrogenase metal cofactors is central to nitrogen fixation. However, the P-cluster and iron molybdenum cofactor, each containing eight irons, have resisted detailed characterization of their electronic properties. Through exhaustive many-electron wavefunction simulations enabled by new theoretical methods, we report on the low-energy electronic states of the P-cluster in three oxidation states. The energy scales of orbital and spin excitations overlap, yielding a dense spectrum with features we trace to the underlying atomic states and recouplings. The clusters exist in superpositions of spin configurations with non-classical spin correlations, complicating interpretation of magnetic spectroscopies, while the charges are mostly localized from reorganization of the cluster and its surroundings. Upon oxidation, the opening of the P-cluster significantly increases the density of states, which is intriguing given its proposed role in electron transfer. These results demonstrate that many-electron simulations stand to provide new insights into the electronic structure of the nitrogenase cofactors.Comment: 23 pages, 5 figure

Predicting the Impact of Changing Speed Limits on Traffic Safety and Mobility on Indiana Freeways

After repeal of the National Maximum Speed Limit Law, states were allowed to set individual speed limits on their interstate roads. Several states opted for a uniform speed limit while others implemented differential speed limits. The current speed limit on Indiana rural freeways limits speed of passenger cars to 70 mph and restricts to 65 mph speed of vehicles with a gross weight of 26,000 pounds or more. Indiana’s speed limit on urban freeways is mostly 55 mph, but varies from 50 mph on certain downtown sections to 65 mph on some suburban sections. Previous studies comparing uniform and differential speed limit settings as to safety and mobility produced inconclusive or conflicting results. This study evaluates the safety and mobility effects of alternative speed limit scenarios on Indiana interstate freeways. Differences in travel time, vehicle operation, and traffic safety were used to compare the speed-limit scenarios. The effect of speed limit was evaluated in hourly periods. The traffic conditions in these periods were classified as uncongested, intermediate, and congested and the speed limit effects were analyzed in relation to these conditions. Rural and urban freeways were analyzed separately and distinct speed models were developed for cars and trucks. Safety was estimated by probability of crash and the conditional probability of crash injury severity. Speed limit was found to affect mobility and safety mostly in non-congested traffic conditions, while no significant effects were found in congested conditions. A limited effect was detected in intermediate traffic conditions on rural freeways. Results indicate that replacing the differential 70/65 mph speed limit on Indiana rural roads with the uniform speed limit of 70 mph may be beneficial for both safety and mobility. Increasing speed limits on urban interstates is confirmed to be beneficial for mobility but detrimental to safety

Using Emerging and Extraordinary Data Sources to Improve Traffic Safety

The current safety management program in Indiana uses a method based on aggregate crash data for conditions averaged over several-year periods with consideration of only major roadway features. This approach does not analyze the risk of crashes potentially affected by time-dependent conditions such as traffic control, operations, weather and their interaction with road geometry. With the rapid development of data collection techniques, time-dependent data have emerged, some of which have become available for safety management. This project investigated the feasibility of using emerging and existing data sources to supplement the current safety management practices in Indiana and performed a comprehensive evaluation of the quality of the new data sources and their relevance to traffic safety analysis. In two case studies, time-dependent data were acquired and integrated to estimate their effects on the hourly probability of crash and its severity on two selected types of roads: (1) rural freeways and (2) signalized intersections. The results indicate a considerable connection between hourly traffic volume, average speeds, and weather conditions on the hourly probability of crash and its severity. Although some roadway geometric features were found to affect safety, the lack of turning volume data at intersections led to some counterintuitive results. Improvements have been identified to be implemented in the next phase of the project to eliminate these undesirable results

A new perspective from hypertournaments to tournaments

A $k$-tournament $H$ on $n$ vertices is a pair $(V, A)$ for $2\leq k\leq n$, where $V(H)$ is a set of vertices, and $A(H)$ is a set of all possible $k$-tuples of vertices, such that for any $k$-subset $S$ of $V$, $A(H)$ contains exactly one of the $k!$ possible permutations of $S$. In this paper, we investigate the relationship between a hyperdigraph and its corresponding normal digraph. Particularly, drawing on a result from Gutin and Yeo, we establish an intrinsic relationship between a strong $k$-tournament and a strong tournament, which enables us to provide an alternative (more straightforward and concise) proof for some previously known results and get some new results.Comment: 10 page

Electronic landscape of the P-cluster of nitrogenase as revealed through many-electron quantum wavefunction simulations

The electronic structure of the metal cofactors of nitrogenase is central to biological nitrogen fixation. However, the P-cluster and iron molybdenum cofactor, each containing eight metal ions, have long resisted detailed characterization of their low-lying electronic states. Through exhaustive many-electron wavefunction simulation, we report on the full low-energy landscape of the P-cluster in three biologically relevant oxidation states. We trace the origin of the low-lying spectrum to the underlying local atomic states and their global recoupling, and how the interplay between antiferromagnetism, delocalization, and spin frustration as the geometry changes upon oxidation gives rise to the structure of the electronic landscape. Our results support the narrative that many-electron wavefunction simulations stand to provide a resolution of the complicated cofactors in nitrogenase at the electronic level