船舶产品三维设计仿真验证技术研究与应用

船舶产品结构复杂、系统繁多,产品信息多样且数据量庞大,在设计阶段发现并解决问题,是提高设计质量的重要环节.通过梳理船舶产品三维设计仿真验证的需求,提出了仿真验证技术方案,阐述了船舶产品三维设计仿真验证的关键技术及解决途径,开发了仿真验证系统,并在多型JC产品中进行了工程应用,对及早发现建造、使用、维护等过程中产生的问题具有重要意义.     

基于PLC的大型油船燃油锅炉仿真系统的开发

为解决航海教育中大型油船燃油锅操作培训的问题，以大型油船燃油锅炉自动控制系统为对象，利用在自动化领域广泛使用并得到各国船级社认可的S7—300可编程序控制器，使用STEP7V5．3编程软件，开发了基于PLC的大型油船燃油锅炉仿真系统，实现了大型油船燃油锅炉的各种控制功能的仿真，仿真控制曲线符合实际。硬件的设计和软件的开发能有效地代替真实锅炉进行操作培训。     

汽车防抱制动系统模糊控制的研究

本文介绍了汽车防抱制动系统的基本原理、建立了车辆制动系统的数学模型及模糊控制算法,并对基于滑移率的模糊控制防抱制动系统进行了计算机仿真研究。     

考虑氯化钠中毒影响的PEMFC电化学性能仿真

氯化钠中毒对质子交换膜燃料电池(Proton Exchange Membrane Fuel Cell ,PEMFC)电化学性能有重要影响。通过量纲分析方法修正电化学模型并利用COMSOL Multiphysics平台量化分析氯化钠浓度对质子交换膜燃料电池性能影响,最后验证了修正电化学模型的准确性。结果表明：随着阴极空气中氯化钠浓度增大,电池电化学性能降低。低电流密度时,氯化钠浓度变化对质子交换膜燃料电池极化曲线、功率密度曲线几乎无影响;中、高电流密度时,电池输出电压、最大输出功率随氯化钠浓度增加而降低。当氯化钠浓度达到 8×10^-5mg·cm^-3,膜最大、最小电流密度分别下降30.83%、25.23%,最大输出功率密度下降50.00%。 关键词：质子交换膜燃料电池;氯化钠中毒;电池性能;数值仿真     

Siting charging stations for electric vehicle adoption in shared autonomous fleets

The transportation sector is undergoing three revolutions: shared mobility, autonomous driving, and electrification. When planning the charging infrastructure for electric vehicles, it is critical to consider the potential interactions and synergies among these three emerging systems. This study proposes a framework to optimize charging infrastructure development for increasing electric vehicle (EV) adoption in systems with different levels of autonomous vehicle adoption and ride sharing participation. The proposed model also accounts for the pre-existing charging infrastructure, vehicle queuing at the charging stations, and the trade-offs between building new charging stations and expanding existing ones with more charging ports.Using New York City (NYC) taxis as a case study, we evaluated the optimum charging station configurations for three EV adoption pathways. The pathways include EV adoption in a 1) traditional fleet (non-autonomous vehicles without ride sharing), 2) future fleet (fully autonomous vehicles with ride sharing), and 3) switch-over from traditional to future fleet. Our results show that, EV adoption in a traditional fleet requires charging infrastructure with fewer stations that each has more charging ports, compared to the future fleet which benefits from having more scattered charging stations. Charging will only reduce the service level by 2% for a future fleet with 100% EV adoption. EV adoption can reduce CO₂ emissions of NYC taxis by up to 861 Tones/day for the future fleet and 1100 Tones/day for the traditional fleet.     

一种新的鱼雷垂直命中目标的制导方法

该文针对鱼雷采用前视角声纳和旁视声纳识别和跟踪目标,引入了初始导引段跟踪虚拟目标的概念,提出一种新的精确制导方法,给出了导引跟踪和垂直命中弹道的数学模型。经仿真和分析表明：该制导方法对攻击目标的初始态势几乎没有限制,即使目标为逃避攻击进行转向机动,也能垂直命中目标。     

Electric vehicles in car sharing networks – Challenges and simulation model analysis

In this paper, we examine the operation of electric vehicles in urban car sharing networks. After surveying strategic and operational differences and comparing them to gasoline-fueled cars, a simulation study was carried out. The proposed discrete event simulation tool covered important operational characteristics of electric vehicles, including realistic charging routines. Different vehicle types were compared under various conditions and on multiple markets to determine their performance. The data obtained indicated the competitiveness of electric vehicles in car sharing networks. Key success factors included advantageous relations between the market environment (e.g. electricity and fuel prices) and important characteristics of electric cars (e.g. price and range).     

An investment appraisal method to compare LNG-fueled and conventional vessels

Ever stricter emission regulations stimulate vessel owners to consider the adoption of alternative marine fuels, such as Liquefied Natural Gas (LNG). In deciding whether to invest in LNG-fueled vessels, initial investment and operating costs are decisive factors that have not yet been fully studied in the literature. In this paper, we present a new investment appraisal method to compare the costs of LNG-fueled vessels with conventional vessels. We analyze the fuel costs and overall exploitation costs by simulating bunker planning decisions under stochastic fuel prices, presence in emission controlled areas, and route lengths. Our analyses reveal that the fuel costs of LNG-fueled vessels are often lower than those of conventional vessels, even under unfavorable LNG prices. Due to the higher initial investment costs in LNG-fueled vessels, these fuel cost reductions do not always translate into lower overall exploitation costs. By conducting numerical experiments, we identified conditions under which the exploitation costs of LNG-fueled vessels are lower than conventional vessels.     

An agent-based multimodal simulation model for capacity planning of a cross-border transit facility

Cross-border transit facilities constitute major public investment, and thus must serve the long-term needs of the communities, such as providing access to schools and businesses, contributing to a shared regional culture and lifestyle, fostering international trade, and supporting jobs for the region’s residents. Numerous studies have been conducted to evaluate the economic implications of vehicular flow delays at border crossings, however none of the studies focused on assessing cross-border flow of bus passengers and pedestrians. Since pedestrians are considered to be autonomous, intelligent, and perceptive, it is a challenging task to predict pedestrian movement and behavior in comparison to vehicular flows which follow a specific set of traffic rules. This paper presents a multiagent based multimodal simulation model to evaluate the capacity and performance of a cross-border transit facility. The significance of this research is the use of dynamic mode choice functionality in the model, which allows an individual person to make instantaneous choices between available modes of transportation. The scope of interest of the paper is limited to simulating access interface, circulation areas, ancillary and processing facilities. The developed model was calibrated to ensure realistic performance, and validated against specific performance criteria such as throughput per processing facility. In order to demonstrate the applicability of the developed simulation model, capacity and operational planning of a pedestrian transit facility was performed. The relative performance of alternative design or configuration was evaluated using the level of service criteria. Lastly, the effectiveness of each proposed capacity or operational improvement strategy was compared to the “do-nothing” scenario.     

Case studies of shipping along Arctic routes. Analysis and profitability perspectives for the container sector

Arctic sea routes have for long attracted interest from observers and shipping companies because of their shorter distances between the Atlantic and the Pacific. The prevalence of sea ice prevented the real development of a significant traffic, but did not prevent research from trying to assess the economic viability of these routes. With the actual present melting of sea ice in the Arctic, this effort at modeling the profitability of Arctic shipping routes received a new impetus. However, the conclusions of these studies vary widely, depending on the chosen parameters and their value. What can be said of these models, from 1991 until 2013, and to what extent can a model be drawn, capitalizing on twenty years of simulations?