Collision avoidance path planning in multi-ship encounter situations

Journal of Marine Science and Technology - Collision avoidance path planning is still one of the essential problems in the design and application of an intelligent maritime navigation system. Its...     

舰船加筋板局部强度评估中的总纵应力折减系数研究

舰船加强筋尺寸的合理确定一直是结构设计中的热点问题。本文综合考虑总纵弯曲应力和局部载荷的相互作用,研究加强筋的许用应力折减系数(C_s)的影响因素与合理取值方法。通过分析加强筋的力学模型、对比不同规范中的C_s取值,以及用非线性有限元软件Abaqus计算一系列加筋板模型,拟合C_s曲线并与规范对比,并验证剖面对称性和局部载荷作用方向对C_s取值的影响方式,丰富了舰船局部强度校核方法的技术背景,为板架设计、舰船三维局部校核程序开发提供借鉴。     

外加电流阴极保护技术在天津港滚装码头预制梁中的应用

外加电流阴极防护是钢筋混凝土结构防腐蚀的主要技术手段之一。文章结合外加电流阴极保护技术在天津港滚装码头预制梁工程中的实际应用,介绍了外加电流阴极保护的原理和保护效果,是国内工程中的首次应用,将为我国今后外加电流阴极防护技术的发展和进步提供重要的参考和借鉴。     

内河双燃料船LNG储气罐位置的确定

为确保内河双燃料船LNG储气罐安放位置的科学性及可靠性,研究如何把层次分析法和模糊数学理论应用到储气罐位置的综合评价中。通过对航行船只的调查研究,确定双燃料动力船安全评价指标和各项指标分级隶属函数,从而建立双燃料动力船安全评价的多层次模糊综合评价体系。     

浅述重力式码头沉箱预制在连云港港赣榆港区一期工程中质量控制要点

由于深水泊位建造日趋增多,沉箱预制逐渐向高大发展。保证质量犹为重要。结合在连云港港赣榆港区一期工程中沉箱预制施工管理实践,介绍施工工艺流程。分析施工中存在的问题。阐述施工过程中主要工序的质量控制要点。     

某型船电网振荡的原因分析及对策

本文分析了某型船电力系统在电网振荡时各电气参数变化的特点及电网发生振荡的原因,阐述了处理电网振荡的方法,提出了一种新的处理方法,并提出了一些建议。     

内河船舶波浪载荷研究

利用内河波浪散布图和修订波浪谱对内河系列船舶进行了波浪载荷的计算预报,首次分析了内河船舶波浪载荷的规律和特点,并与俄罗斯内河登记局(RRR)和法国-德国船级社(B-G)的内河规范载荷对应的等效模数要求进行了比较分析。结合实船测试结果表明：波浪载荷变化规律与国外同类规范一致,预报波浪载荷水平与测试结果及国外同类规范要求相当。内河船舶波浪载荷预报应考虑航速和水深的影响,载荷预报结果可以作为制定内河波浪载荷公式的基础。     

沉管隧道穿越江河海湾的优越性

文章从工程的造价、质量、工期、安全、生态环境及社会效益等角度,通过对沉管隧道与桥梁、盾构隧道渡越方案的分析、对比和论证,着重指出采用沉管隧道方案穿越江河海湾的诸多优越性.     

Incorporating the extended theory of planned behavior in a school travel mode choice model: a case study of Shaoxing,China

Travel to and from school can have social, economic, and environmental implications for students and their parents. Therefore, understanding school travel mode choice behavior is essential to find policy-oriented approaches to optimizing school travel mode share. Recent research suggests that psychological factors of parents play a significant role in school travel mode choice behavior and the Multiple Indicators and Multiple Causes (MIMIC) model has been used to test the effect of psychological constructs on mode choice behavior. However, little research has used a systematic framework of behavioral theory to organize these psychological factors and investigate their internal relationships. This paper proposes an extended theory of planned behavior (ETPB) to delve into the psychological factors caused by the effects of adults’ cognition and behavioral habits and explores the factors’ relationship paradigm. A theoretical framework of travel mode choice behavior for students in China is constructed. We established the MIMIC model that accommodates latent variables from ETPB. We found that not all the psychological latent variables have significant effects on school travel mode choice behavior, but habit can play an essential role. The results provide theoretical support for demand policies for school travel.     

A Pareto-improving hybrid rationing and pricing policy with multiclass network equilibria

This paper extends the work on Pareto-improving hybrid rationing and pricing policy for general road networks by considering heterogeneous users with different values of time. Mathematical programming models are proposed to find a multiclass Pareto-improving pure road space rationing scheme (MPI-PR) and multiclass hybrid rationing and pricing schemes (MHPI and MHPI-S). A numerical example with a multimodal network is provided for comparing both the efficiency and equity of the three proposed policies. We discover that MHPI-S can achieve the largest reduction in total system delay, MHPI can induce the least spatial inequity and MHPI-S is a progressive policy which is appealing to policy makers. Furthermore, numerical results reveal that different classes of users react differently to the same hybrid policies and multiclass Pareto-improving hybrid schemes yield less delay reduction when compared to their single-class counterparts.