大众的宏图大略

第一眼,你会觉得大众的电动踏板车不过是又一款概念车——只为设计师的幻想而生;但静下心来细究此车,它虽然是今年年初的上海车展上最小的一款概念车,但却有可能成为最重要的一款。在我们和大众中国的设计总监SimonLoasby聊天时,发现他是一个热情奔放的英国人,他对电动踏板车的前景极为乐观。他认为,与其说这是一     

License plate extraction method for identification of vehicle violations at a railway level crossing

The primary cause of most railroad accidents is vehicle entry into railway level crossings despite warning messages. To identify drivers who violate railway level crossing regulations, vehicle license plate recognition can be applied at railway level crossings. The purpose of this paper is to present an effective method for extracting the license plate region from vehicle images taken at railway level crossings. The method proposed in this paper uses the variation in the gray-level values across the image of a license plate. For license plate region extraction, the character region is first recognized by identifying the character width and the difference between the background region and the character region. The license plate region is then extracted by finding the inter-character distance in the plate region. In addition, the license plate type is identified by the difference in the gray-level value between the background region and the character region. The proposed method is effective in solving the current challenges in extracting the license plate region from the damaged frames of license plates issued for domestic use, including new types of license plates. According to the experimental results, the proposed method yields a high extraction rate of 99.5% for vehicle license plates.     

双通线加热的热力学及实验分析(英文)

The present investigation deals with process analysis of oxy-acetylene flame assisted double pass line heating for varying plate thickness. oxy-acetylene flame as the heat source for multi pass line heating to achieve 3-D bending of plates with varying thicknesses was studied. The oxy-acetylene flame was modeled as the moving heat source in the FEM analysis. The transient thermal histories were predicted taking into account the temperature dependent thermo-mechanical properties. A comparative study between single pass and double pass line heating residual deformation was also carried out. The temperature distribution and residual deformations predicted by the numerical model developed in the present work compared fairly well with those of the experimental ones.     

A multiobjective chance constrained programming model for supplier selection under uncertainty

Risk management is an inherent part of supplier selection. While companies are enjoying the benefits of outsourcing, risks brought by this practice should be taken into account in the process of decision making. This paper presents a multiobjective stochastic sequential supplier allocation model to help in supplier selection under uncertainty. Demand for products, capacities at suppliers as well as transportation and other variable costs are the main sources of uncertainty and are modeled using probability distributions. Disruptions are exogenous events and the model provides proactive mitigation strategies against disruptions by assigning backup suppliers who can be used in case of a default at a primary supplier. When there is no disruption, the model’s solution is an optimal supplier order assignment, considering operational risks.     

GPS-based optimization of plug-in hybrid electric vehicles’ power demands in a cold weather city

Using the WPG03 duty cycle developed from global positioning data collected in Winnipeg, Canada, real world energy demands and costs are modeled. Three types of plug-in hybrid electric vehicles, four temperatures and two charging scenarios are compared to a vehicle with an internal combustion engine. Cold temperatures are shown to greatly affect vehicle operation energy costs, which is an important consideration for cold weather cities such as Winnipeg. The largest energy cost savings are obtained for smaller-battery plug-in hybrids that had the opportunity to charge during the day.     

Blast loaded plates

Plates form one of the basic elements of structures. Land-based structures may be subjected to air blast loads during combat environment or terrorist attack, while marine structures may be subjected to either air blast by the attack of a missile above the water surface or an underwater explosion by the attack of a torpedo or a mine or a depth charge and an aircraft structure may be subjected to an in-flight attack by on-board explosive devices. Furthermore, gas explosion occurs in offshore installations and industries. This review focuses on the phenomenological evolution of blast damage of plates.     

Traffic noise studies in a tropical environment

This paper reports upon a survey of traffic noise annoyance in three residential districts of Trinidad, West Indies. Householder perceptions were solicited by means of a questionnaire survey and direct measurements of traffic noise levels were taken. The results were compared with surveys elsewhere. It was concluded that household status had little effect on annoyance perception, that at L₁₀ levels greater than 70 dB(A) at a dwelling facade the noise level is unacceptable. L₁₀ levels less than 65 dB(A) at the building facade are not perceived as annoying in the environment considered.     

A Study in Port Planning: The Example of Mina Zayed

The correct number of berths that a port should provide is solved by a model which minimizes the total port usage cost in terms of the costs of berth provision and the costs accruing to ships from time spent in the port. This model is then applied to Mina Zayed in the Arabian Gulf as an aid to future planning, and from different sets of cargo forecasts an optimal stategy is derived using a game-theoretic approach.     

The impact of job assignment rules for straddle carriers on the throughput of container terminals

Straddle carriers represent a critical resource in the handling of containers within a container terminal. It is essential that they are deployed in an as efficient manner as possible. The research presented in this paper is motivated by the need to critically evaluate job assignment rules for straddle carriers that operate in a multiple straddle environment. This is achieved by developing a discrete event simulation model using industrial simulation software to model a container terminal located in Melbourne, Australia. The model accounts for variables such as the number of straddle carriers needed, the speed of straddle carriers, the arrival rate of trucks, and the job assignment rule. A principal finding of the study is that increasing the number of straddles in the present set‐up from 6 to 7 has a negligible effect on daily throughput. However, an increase in the number of straddles to 7 is expected to have a profound effect on reducing the average waiting time of trucks within the terminal from over 16 minutes to under 9 minutes, a decrease of 46.5%. However, a further increase in the number of straddles results in no further increase in daily throughput. It was observed that the throughput of the terminal is very sensitive to the speeds at which straddles travel. The management of the terminal has proposed a new heuristic job assignment rule for straddles, because the present rule does not assign the jobs to straddles closest to the truck requesting to load or unload a container. As a result a new heuristic job assignment rule was tested. The simulation results revealed that both the old and new rules performed equally well using performance indicators such as average container flow time, daily throughput, average waiting time of jobs, number of jobs in the queue, and straddle utilisation. Therefore, the new rule will not improve these performance measures if implemented