Estimating traffic demand risk – A multiscale analysis

This paper proposes a novel method for estimating the traffic demand risk associated with transportation. Using mathematical properties of wavelets, we develop a statistical measure of traffic demand sensitivity with respect to GDP. This measure can be adapted in a flexible way to capture risk levels relevant for different investment horizons. We demonstrate the timescale decomposition of risk with Swedish traffic demand data for 1950–2005. In general, rail transport shows a stronger co-movement with GDP than road transport. Moreover, we examine the volatility exhibited by traffic demand. Our findings suggest that rail investments are more risky than road investments. Since the findings can be used for optimal investment timing and for choice between public investment alternatives, they are deemed important for public policy in general.     

轻轨车辆的制造

根据庞巴迪运输部德国车辆制造有限公司（ＤＷＡ）轻轨车设计开发、车体模型制作与试验等课题研究情况，进一步介绍如何实现车体轻量化结构、防撞击设计、防火安全及采用的先进的焊接技术。     

肿瘤免疫研究的回顾与展望

20多年来,本校免疫病理研究室一直从事肿瘤免疫的研究,从研究肿瘤浸润淋巴细胞的活化和肿瘤逃逸的机制开始,到探索诱导浸润淋巴细胞(tumor infiltrating lymphocytes, TIL)活化的最佳条件,并将这些研究结果转化为肿瘤免疫治疗和免疫预防的实践,从一个侧面反映了人类在征服肿瘤道路上的艰苦历程。     

IAA与HRP联合作用对人胰腺癌BXPC-3的细胞毒效应

目的　研究吲哚乙酸(IAA)与辣根过氧化物酶(HRP)在体外共同作用于人胰腺癌BXPC 3 细胞所产生的细胞毒效应。方法　MTT法测定IAA/HRP对BXPC 3细胞增殖的影响;流式细胞仪分析BXPC 3 细胞周期时相变化;胎盘兰(曲利本兰)排斥试验,研究IAA/HRP对BXPC 3 细胞死亡率的影响;原位细胞凋亡检测试剂盒检测IAA/HRP作用后BXPC 3细胞的凋亡。结果　IAA/HRP体外对BXPC 3 细胞有抑制生长的效应,且这种效应有浓度和时间依赖性;BXPC 3细胞在IAA/HRP作用48 h后细胞周期被阻滞在G1期和G2期;IAA/HRP作用72 h后对照组和药物组的凋亡细胞数存在着显著性差异,且凋亡细胞数有浓度依赖性。结论　IAA/HRP对胰腺癌BXPC 3 细胞有细胞毒作用,可体外抑制细胞的增殖,诱导凋亡。     

萘乙酸抑制K562细胞增殖作用的初步研究

目的研究萘乙酸(NAA)对K562细胞增殖的抑制作用。方法应用MTT法、细胞计数法、流式细胞术、分裂指数分析、tunnel法以及姊妹染色单体交换(sister chromatid exchange,SCE)和微核制备,对NAA处理的K562细胞进行细胞增殖、细胞周期、凋亡以及染色体损伤检测。结果与对照组相比,NAA可以有效抑制K562细胞的生长,并将细胞阻滞在G1期,降低细胞分裂指数,促进细胞凋亡,提高K562细胞SCE频率以及微核形成率。结论NAA具有抑制K562细胞增殖的作用。     

新型EGFP标记的杆状病毒转移载体的构建及EGFP的制备

目的构建可表达增强型绿色荧光蛋白(EGFP)融合蛋白的昆虫杆状病毒转移载体,利用Sf-9细胞表达、制备EGFP。方法用PCR法从pEGFP质粒中扩增EGFP基因,NcoⅠ/SalⅠ双酶切,克隆入杆状病毒转移载体NcoⅠ/SalⅠ酶切位点之间,获得pFB-EGFP质粒;转化E.coliDH10Bac,通过转座子Tn7的介导,获得重组杆状病毒Ac-EGFP;感染Sf-9昆虫细胞;利用激光共聚焦显微镜和SDS-PAGE观察并检测EGFP的表达。非变性法纯化EGFP。结果荧光显微镜和激光共聚焦显微镜证实感染的Sf-9细胞可表达EGFP;通过SDS-PAGE获得的EGFP,大小为27ku。结论重组pFB-EGFP载体具备表达EGFP的能力,为分子生物学研究提供了一种新型可表达EGFP融合蛋白的昆虫杆状病毒表达载体。     

Practicability study on the suitability of artificial,neural networks for the approximation of unknown steering torques

For steer-by-wire systems, the steering feedback must be generated artificially due to the system characteristics. Classical control concepts require operating-point driven optimisations as well as increased calibration efforts in order to adequately simulate the steering torque in all driving states. Artificial neural networks (ANNs) are an innovative control concept; they are capable of learning arbitrary non-linear correlations without complex knowledge of physical dependencies. The present study investigates the suitability of neural networks for approximating unknown steering torques. To ensure robust processing of arbitrary data, network training with a sufficient volume of training data is required, that represents the relation between the input and target values in a wide range. The data were recorded in the course of various test drives. In this research, a variety of network topologies were trained, analysed and evaluated. Though the fundamental suitability of ANNs for the present control task was demonstrated.     

Exploring maritime ergonomics from a bottom line perspective

The present paper reports a study composed of three research activities exploring the economics of ergonomics in a shipping context. First, a literature study aimed to review previous studies on the economics of ergonomics in general and within the maritime domain in particular; and moreover, to ascertain the key ergonomic factors addressed in contemporary maritime ergonomic research. Second, the concept of ergonomics was probed from a stakeholder perspective through nine semi-structured qualitative interviews. Third, structured interviews were held with representatives of ten Swedish shipping companies to investigate if the shipowners are aware of and calculate the economic effects of ergonomics.     

Virtually being there: Human aspects of shore-based ship assistance

Shore-based ship assistance is a topic that increasingly is attracting attention from the maritime community. Subjects such as shore-based pilotage and VTS are often discussed and there is technological and political pressure towards more extensive forms of such assistance. Perhaps less often mentioned, but not less important, is the human side of these subjects. The present paper examines two of the central concerns for the people who actually work within today’s VTS centers, namely communication and trust. The study consisted of a literature review, study visits, observations and interviews. Communication and trust are found to be closely related, and one main finding is that adapting one’s means of communication to the context can be a very powerful (and necessary) tool for the creation of trust. Another important result is that the ability of the shore-based operator to see the situation from the viewpoint of the crew is crucial for the creation and maintenance of trust.     

发动机冷却风扇气动性能的计算方法

介绍了发动机冷却风扇气动性能的计算方法、建模方法和求解技术。利用CFD软件Fluent计算了某款风扇的静压、功率和效率与流量的关系,试验结果验证了计算结果。通过对风扇内部压力场和速度场的研究,分析了风扇效率低下的原因,并提出了改进方案。计算结果表明,叶尖间隙对风扇性能有重要影响,叶尖间隙过大将导致风扇效率低下,故应减小叶尖间隙或安装圆环以提高风扇性能。