Improving Crowded Object Detection via Copy-Paste

Crowdedness caused by overlapping among similar objects is a ubiquitous challenge in the field of 2D visual object detection. In this paper, we first underline two main effects of the crowdedness issue: 1) IoU-confidence correlation disturbances (ICD) and 2) confused de-duplication (CDD). Then we explore a pathway of cracking these nuts from the perspective of data augmentation. Primarily, a particular copy-paste scheme is proposed towards making crowded scenes. Based on this operation, we first design a "consensus learning" method to further resist the ICD problem and then find out the pasting process naturally reveals a pseudo "depth" of object in the scene, which can be potentially used for alleviating CDD dilemma. Both methods are derived from magical using of the copy-pasting without extra cost for hand-labeling. Experiments show that our approach can easily improve the state-of-the-art detector in typical crowded detection task by more than 2% without any bells and whistles. Moreover, this work can outperform existing data augmentation strategies in crowded scenario.Comment: Accepted by AAAI202

Evaluating Operational Effects of Bus Lane with Intermittent Priority under Connected Vehicle Environments

Bus lane with intermittent priority (BLIP) is an innovative method to improve the reliability of bus services while promoting efficient usage of road resources. Vehicle-to-vehicle (V2V) communication is an advanced technology that can greatly enhance the vehicle mobility, improve traffic safety, and alleviate traffic jams. To explore the benefits of BLIP operation under a connected environment, this study proposed a three-lane cellular automata (CA) model under opening boundary condition. In particular, a mandatory BLIP lane-changing rule is developed to analyze special asymmetric lane-changing behaviors. To improve the simulation accuracy, a smaller cell size is used in the CA model. Through massive numerical simulations, the benefits and influences of BLIP are explored in this paper. They include impacts on neighborhood lanes such as traffic density increasing and average speed decreasing, lane-changing behaviors, lane usage, and the impacts of bus departure interval and clear distance on the road capacity of BLIP. Analysis of traffic flow characteristics of BLIP reveals that there is a strong relationship among bus departure interval, clear distance, and road capacity. Furthermore, setting conditions for deployment of BLIP under the V2V environment such as reasonable departure interval, clear distance, and traffic density are obtained

Electrochemically Induced Amorphous-to-Rock-Salt Phase Transformation in Niobium Oxide Electrode for Li-Ion Batteries

Intercalation-type metal oxides are promising negative electrode materials for safe rechargeable lithium-ion batteries due to the reduced risk of Li plating at low voltages. Nevertheless, their lower energy and power density along with cycling instability remain bottlenecks for their implementation, especially for fast-charging applications. Here, we report a nanostructured rock-salt Nb2O5 electrode formed through an amorphous-to-crystalline transformation during repeated electrochemical cycling with Li+. This electrode can reversibly cycle three lithiums per Nb2O5, corresponding to a capacity of 269 mAh g−1 at 20 mA g−1, and retains a capacity of 191 mAh g−1 at a high rate of 1 A g−1. It exhibits superb cycling stability with a capacity of 225 mAh g−1 at 200 mA g−1 for 400 cycles, and a Coulombic efficiency of 99.93%. We attribute the enhanced performance to the cubic rock-salt framework, which promotes low-energy migration paths. Our work suggests that inducing crystallization of amorphous nanomaterials through electrochemical cycling is a promising avenue for creating unconventional high-performance metal oxide electrode materials

A transient numerical study for heat transfer and flow characteristics of dimpled piston cooling gallery of a diesel engine

Piston cooling gallery is an effective cooling method to achieve an acceptable piston temperature field. This paper aims to analyze the effects of teardrop dimples size and dimple head-and-tail orientation on flow and heat transfer inside the cooling gallery. To do so, the computational fluid dynamics model for galleries with different teardrop dimples were established. The results indicate that the local oil flow patterns in the axial and circumferential directions are affected by the dimples. Compared with smooth gallery, the presence of dimple enlarges the fluid charge ratio (FCR). Specifically, when radius of teardrop shaped dimples are R2 and R3 respectively, their corresponding gallery FCRs achieve 55% and 58%. Further, the variation in FCR makes a difference in the distribution of heat transfer, an in-depth analysis finds the dimples increase the heat transfer area between the gallery surface and the oil and simultaneously reduce the space of oil suspending in the gallery. Therefore, the heat transfer coefficient of a dimpled gallery is always greater than that of the smooth gallery, with the maximum improvement of 2.42%. Moreover, the change of heat transfer distribution reconstructs the heat transfer uniformity of the cooling gallery, with the maximum improvement of 24.25%

Synthesis of B4C-TiB2 composite powders by the carbide boronizing process

B4C-TiB2 composite powders were synthesized by a carbide boronizing process, i.e. the solid state reaction between TiC and amorphous boron powders. The particle size of the raw TiC powders was found to greatly affect the phase composition of the composite powders. Nano-TiC powders could be totally consumed and turned into TiB2 phase with heat treatment at 1100 degrees C for 1 h whereas micro-TiC powders was still present even at 1400 degrees C for 1 h. The synthesized B4C-TiB2 composite powders have a small particle size and a homogenous phase distribution, indicating high sintering activity. (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved

AN INVESTIGATION OF LUBRICATION CHARACTERISTICS AND PARAMETERS INFLUENCE ON MAIN BEARING IN HORIZONTAL DIESEL ENGINE

Based on the horizontal two-cylinder diesel engine,the main bearing elastohydrodynamic lubrication model was constructed in AVL EXCITE PU software,some results were acquired at the maximum torque working condition（ 1600 r / min）under the consideration of the roughness of bearing bush and journal. The results showed that three main bearings’ minimum film thickness and maximum film pressure satisfy the design criterion. The 2nd main bearing ’s maximum film pressure is about150 MPa which is the oil pressure limits. The 2nd main bearing orbit was obvious centripetal movement,which showed that the2 nd main bearing had obvious bending moment. The bending moment was considered to analysis object,and the parameters influence to bending moment is width of main bearing,bearing clearance,oil groove width and oil port position with the orthogonal experimental design