基于LabVIEW的数据回放技术

美国NI公司开发的LabVIEW是一种真正意义上的图形化编程语言,以其界面友好、开发周期短、功能强大在世界范围内得到广泛应用。本文借助于该平台开发出非线性条件下电能测试系统的数据回放软件。该软件功能丰富,界面简洁,操作方便,可再现实时采集的数据,为设备输出参量计算与监控、系统单元匹配、性能评估、维护与改进提供数据依据与指导。     

高速公路项目节能分析与评价

结合福州至银川高速公路十堰至天水联络线湖北境段工程可行性研究成果,阐述了高速公路项目前期工作中的节能分析方法,并基于节能分析结果对路线方案进行了比选。     

武汉地铁2号线区间隧道超浅埋地层矿山法施工技术

武汉地铁2号线一期工程武昌段区间隧道以矿山法施工为主.其中虎泉至名都站区间隧道存在240 m左右的超浅埋段.洞顶覆盖层厚度基本均小于1倍洞径.且上覆地层为人工杂填土和粘土,人工杂填土层发育有上层滞水.根据超浅埋段地质条件和注浆试验结果,采用了地表注浆、分台阶预留核心土、双排注浆小导管超前支护、钢格栅加强支护、喷混凝土封闭成环、回填注浆等整体开挖施工方案和支护措施.施工监测结果表明:地表沉降及周边建筑物的变形满足相应的控制标准,有效地提高了施工的安全性,取得了较好的施工效果.     

增压法和加热法真空预压新工艺的机理和加固效果探讨

真空预压是一种应用广泛的软土地基处理工艺。针对增压法真空预压、加热法真空预压两种新工艺,结合现场试验及工程实例对其进行分析和探讨。结果表明,增压法真空预压在地基内充入高压气体不能改变土体的饱和状态,同时高压气体会降低真空预压的真空度并可能阻碍真空度沿塑料排水板向深层传递;增压法真空预压的加固效果存在较大差异,在实际工程施工前应做好试施工验证其加固效果;加热法真空预压法通过升高土体温度提高渗透系数、缩短固结时间,同时增大固结沉降量,尤其适用于低渗透性的软黏土或淤泥;针对加热法真空预压现场应用难题提出了新型加热型塑料排水板和闷晒式太阳能加热循环水等改进方法,分别较好地解决了加热塑料排水板的制作加工、加热成本高的难题。     

The environmental costs and economic implications of container shipping on the Northern Sea Route

The Northern Sea Route (NSR) has tremendous potential for ocean shipping between Europe and Asia due to the savings from shorter transit time and distance. However, the Arctic area is environmentally vulnerable and thus there is a trade-off between NSR’s impacts on environment vs. its economic benefits, especially when compared with the traditional route, such as through the Suez Canal Route (SCR). This study estimates the market shares of different transport modes and alternative shipping routes for the container transport market between Europe and Asia, and the resulting environmental costs. Our result suggests that NSR can be a viable option under the status quo. However, its environmental costs tend to be higher than SCR due to small ship size and low load factor in the present, thus the development of NSR would lead to worse environment outcomes. If these issues can be resolved, NSR can benefit from lower operational and environmental costs, which will lead to higher market share and social welfare. Otherwise, increased use of NSR may lead to higher total environment costs than the status quo.     

基于B/S和C/S架构的船舶动力装置远程故障诊断系统

依据“智能船舶”的理念,针对船舶动力装置故障诊断系统,提出一种基于C/S和B/S混合架构的船舶动力装置远程故障诊断系统。依据B/S和C/S架构的优势,开发了基于C/S架构的数据管理平台,实现了船、岸间的数据、信息交互;将基于模糊神经网络的专家诊断模型应用于B/S架构的岸基船舶动力装置故障诊断系统的故障诊断判别,并利用BP算法训练实例对该模型进行了精度验证。结果表明,系统稳定可靠,故障诊断准确性高,为“智能船舶”发展提供了一个良好的解决方案。     

掺合料对高耐久性清水混凝土外观的影响

针对海洋环境下高耐久性清水混凝土外观缺陷问题,进行混凝土的圆桶及方模试验,研究掺合料对其外观的影响。结果表明,单掺矿粉的清水混凝土表面气泡较多,且直径较大;双掺矿粉和粉煤灰的清水混凝土的色泽会偏黑,偏暗;双掺矿粉和石粉的清水混凝土表面有较多大直径气泡;而双掺矿粉和硅粉的清水混凝土,色泽较为明亮均匀、气泡较少且气泡尺寸较小,整体均匀性在双掺体系中最好;三掺矿粉、粉煤灰和硅粉的清水混凝土,相对于所有其他系列的清水混凝土,外观改善情况最好,整体色泽均匀明亮,且气泡较少,将其应用于某海洋环境下清水混凝土工程,效果良好。     

Estimation of multinomial probit-kernel integrated choice and latent variable model: comparison on one sequential and two simultaneous approaches

Integrated choice and latent variable (ICLV) model incorporates latent factors into standard discrete choice model with aim to provide greater explanatory power. Using simulated datasets, this study makes a comparison among three estimation approaches corresponding to the sequential approach and two simultaneous approaches including the maximum simulated likelihood with GHK estimator and maximum approximate composite marginal likelihood (MACML) approach, to evaluate their abilities to recover the underlying parameters of multinomial probit-kernel ICLV model. The results show that both simultaneous approaches outperform the sequential approach in terms of estimates accuracy and efficiency irrespective of the sample sizes, and the MACML approach is the most preferable due to its best performance on recovering true values of parameters with relatively small standard errors, especially when the sample size is large enough.     

Accommodating preference heterogeneity in commuting mode choice: an empirical investigation in Shaoxing,China

A latent class model is developed to accommodate preference heterogeneity across commuters with respect to their mode choice between electric bike, private car, and public bus within the context of China. A three-segment solution – ‘electric bike individuals’, ‘private car addicts’, and ‘public bus enthusiasts’ – is identified, each characterized by heterogeneous preferences regarding specific mode attributes and unique socio-demographic profile. The choice model confirms the determinative effects of perceived alternative attributes on commuting mode choice, while the traditionally used objective attributes – travel time and cost – are found to have relatively small influences. The membership model provides solid explanations for these segment-specific preferences. This study provides a better understanding of the nature of mode choice behavior, which can be useful for strategies tailored to a specific segment in order to promote the use of sustainable transport modes.     

关于综合评价模型中复合效用序位在同一置换空间中的唯一性

本文讨论了在相互偏好独立的条件下效用置换的统一函数形式,证明了加性结构的总体复合效用与评价指标的效用函数形式无关和在同一效用置换空间中的序位具有唯一性。