Airlines within airlines: Assessing the vulnerabilities of mixing business models

In this paper we examine two questions; what is it that makes some cases of airlines within airlines apparently successful while in many other cases it is just the opposite? And second, why would a carrier attempt such a strategy, is there a common set of circumstances or is each case unique? In the US, Canada and Europe a number of legacy carriers have sought to respond to LCC entry by creating an LCC within the legacy carriers; most have failed but some have succeeded, most notably in Australia and Germany. We first examine the evolution of the LCC business model and illustrate the different forms it takes today. Following this we provide a discussion of the underlying sources of cost advantage of the LCC and assess which sources are sustainable in the longer term. Finally we examine the conditions under which these apparent successes have occurred and look for common threads. We find market dominance, judicious network planning and co-ordination are necessary conditions for success.     

Understanding How Policy Actors Improvise and Collaborate in the Great Barrier Reef

Complex policy frameworks guide the management of the Great Barrier Reef (GBR) at multiple decision-making levels. Mounting pressure on its outstanding universal value suggests that further improvements in governance are required. There has been little examination of the role of policy actors in addressing complex governance challenges in large scale marine protected areas (LSMPAs) involving multi-layered governance conflicts across diverse contexts. Framed by street level bureaucracy, pragmatic planning theory, and lessons from MPA governance, this paper examines how policy actors improvised and collaborated to advance outcomes in the GBR LSMPA. We assessed practice-focused oral histories with experienced policy actors who negotiated agreements and achieved policy outcomes in the GBR between 1985 and 2016. These policy actors were skilled improvisers, alternating between roles as democratisers, mediators, and negotiators. They used collaboration and facilitative leadership to advance policy in the face of governance problems. This enabled them to adapt policy across multi-level decision systems, address power and information imbalances, and generally deal with conflict and uncertainty. A deeper understanding of improvisation will assist governments and others to address complex challenges in LSMPAs.     

井下低压电力线多载波通信系统的小波基选择

在简要分析我国煤矿配电网的基本结构的基础上,提出基于小波变换的通信系统,该系统采用小波基取代传统的正交频分复用中的余弦函数基的多载波调制技术.通过对6种典型小波基分析比较,结合井下低压电力线的应用条件,给出OFDM通信系统中小波基的选择原则,指出正交性在OFDM系统中具有重要作用.     

从“油轮单壳改双壳”到“油轮改散货轮”

本文主要阐述了油轮改散货船在流程管理、变形控制、安全管理、质量管理、周期控制等方面的难点及防控要点。     

城际铁路与地下道路共构设计大断面方案比选

为合理确定城际铁路与地下道路共构设计时隧道匝道汇入主体结构的大断面方案,采用有限元计算软件Midas Civil分别对平顶顶板、折板形顶板及拱形顶板3种方案进行建模计算,分别对不同方案的位移、应力、弯矩等进行分析。结果表明,拱形顶板与折板形顶板的受力性能均优于平顶顶板,且刚度增大,应力分布合理,弯矩值大幅度减少。综合考虑施工难易程度、工程量等因素,结论是选用折板形式作为隧道与城际铁路合建段大断面的顶板施工方案,具有结构受力合理、施工技术成熟、工程造价可控三大优势。     

可视化技术在港工结构稳定性研究中的应用

可视化技术能够以突出的细节画面再现实验或模拟的过程和结果,使研究人员观察到数据中的隐含现象,进而深入分析实验的结果。利用Dephi编程,以"沉入式大直径圆筒结构施工期稳定性实验研究"的数据和结论为例,应用可视化技术研究开发了可视化软件。该软件可以判断在施工期大圆筒是否满足稳定性的要求,可将数值模拟或物理实验的过程和结果在屏幕上动态地显示出来。     

大断面连拱隧道施工要点探讨

分析大断面连拱隧道的工程特点,总结其主要施工方法和注意事项,对今后公路隧道施工提供参考。     

杭州湾跨海大桥海中区引桥上部结构方案构思与设计

通过设计、施工等多方面的比选,杭州湾跨海大桥海上引桥上部结构采用70 m跨径预应力混凝土连续箱梁,整孔预制架设施工方案。简要介绍海上引桥上部结构的设计构思和部分结构设计细节。     

浅埋、小净距、大跨度扁坦公路隧道结构设计与分析

介绍了浅埋、大跨度、双洞八车道小净距公路隧道的初步设计方案,有限元计算表明水平对拉锚杆和系统锚杆的设置有利于抑制中柱塑性区的交叉连通及拱顶塑性区与地面的连通,所得结论对类似隧道设计和施工有参考价值。     

拱桥极限跨径研究

以拱肋材料的强度为限定条件，研究恒载下分别以抛物线、悬链线作为合理拱轴线时拱桥的极限跨径。并以此为基础，就极限跨径下拱桥的最佳矢跨比范围进行讨论。