Measuring price discovery between nearby and deferred contracts in storable and nonstorable commodity futures markets

Using price discovery measures, including Putniņš’ (2013) information leadership share and intraday data, we quantify the proportional contribution of nearby and deferred contracts in price discovery in the corn and live cattle futures markets. On average, nearby contracts reflect information more quickly than deferred contracts in the corn market, but have a relatively less dominant role in the live cattle market. In both markets, the nearby contract loses dominance when its relative volume share dips below 50%, which typically occurs when the nearby is close to maturity. Regression results indicate that the share of price discovery is mainly related to trading volume and time to expiration in both markets. In the corn market, price discovery share between nearby and deferred contracts is also related to inverse carrying charges, crop year differences, USDA announcements, market crashes, and commodity index position rolls. Differences between corn and live cattle markets are consistent with differences in the contracts’ liquidity and commodity storability.     

Sustainability and visitor management in tourist historic cities: the case of Santiago de Compostela,Spain

Tourism has a leading role in heritage cities and this implies a major challenge. The overall objective of this paper is to evaluate the performance of tourism planning and management with the view of achieving sustainable tourism in the historic center of Santiago de Compostela, Spain. The study addresses topics collected during a long research process of more than 10 years, such as strategic tourism plans, the implementation of quality management systems for tourism, the tourist supply and the regulation of flows. The results show a destination that has introduced alternatives to improve the tourism experience and diversify its offer beyond the Camino de Santiago. There is also growing concern in promoting the sustainability of the historic center. From our point of view, the strengthening of synergies between the different agents involved in the tourism sector of the city has been a key factor in dealing with this situation. However, in this sense, the main problem which is decongesting the tourist flows to the cathedral and its surroundings is still unresolved.     

带阻尼器拉索结构的索力识别研究

为解决带多个阻尼器索结构的索力识别问题,依据动力学相关理论,建立带3个减振器的拉索-减振器动力学模型,推导其频率方程,构造相应的无量纲参数并进行参数分析.结果表明:随着减振器支撑刚度的增加,无量纲振动频率逐渐增大,但这种增大趋势随支撑刚度的继续增加而趋于平缓;随着减振器安装距离的增加,无量纲振动频率逐渐增大,且这种趋势接近线性变化.最后利用有限元分析软件ANSYS并分别采用LINK单元与BEAM单元对其结论进行验证.     

基于同轴电缆的移动信号室内深度覆盖系统设计与实现

针对移动信号室内深度覆盖需求和现有覆盖方案存在的问题，提出了一种以有线电视同轴电缆为入户通道的射频系统。分析了系统原理和几个关键问题，计算了系统各项设计参数，阐述了合路器、跨路器和智能终端三个主要部分的结构及阻抗匹配滤波、同步、放大等关键模块的实现方法。实地测试结果表明，系统各项指标符合设计和应用要求，实现了160 m2高层住宅的信号覆盖，提高了小区测量报告（MR）覆盖率，同时对移动室分系统性能也无影响。所提方案与现有方案相比具有低成本、施工快速、协调简单等优势，是一种新颖实用的室内深度覆盖实现方式。     

海洋资源环境承载力评价研究进展

我国海洋经济的高速增长导致近岸海洋资源趋紧、海洋环境污染加剧,引起了社会各界对海洋资源环境过载问题的高度关注。近年来,海洋资源环境承载力评价研究取得了诸多进展,体现在:(1)对海洋资源环境承载力的概念及内涵有了更加深刻的理解;(2)推动了海洋资源环境单要素承载力和综合承载力评价方法研究;(3)海洋资源环境承载力评价研究的综合应用。通过总结发现,当前海洋资源环境承载力评价对象比较局限,反映承载体与承载对象之间动态关系的评价方法还较为薄弱。因此,在陆海统筹目标下的资源环境承载力综合集成评价需求下,海洋分类评价研究的当务之急是建立基于多要素的海洋资源环境承载力评价技术框架。     

银川市生态赤字分析

依据宁夏和银川市2006年的统计数据,对银川市的生态足迹作了定量分析。结果为银川市2005年的人均生态赤字为2.271565公顷,表明银川市的生态发展不可持续。对计算结果进行分析后,提出了可持续发展的应对措施。     

How Much Will Consumers Pay? A Hedonic Analysis of the Cable Television Industry

Because cable television is the classic example of a bundled commodity, it is difficult to determine how consumers value individual cable networks offered on a typical system. This paper uses a modified hedonic framework to determine the marginal willingness to pay by consumers for individual cable networks. The traditional hedonic framework is adapted to allow for the lack of competition on the supply side of the market. It is clear that consumers do value some types of programming more than other types. Sports, news, and family programming all have positive implicit prices while program guides have negative marginal prices.     

基于游客感知的海滩休闲承载力研究——以泉州湾为例

为丰富海滩休闲承载力研究,从游客感知视角出发,借鉴旅游环境承载力模型,从休闲空间、生活环境、设施服务和综合心理四个维度构建海滩休闲承载力评价指标体系,通过问卷调查法获取基础数据,对福建省泉州湾海滩休闲承载力进行研究。结果表明：泉州湾海滩休闲承载力整体处可载水平;由于旅游资源禀赋和区位条件的差异,泉州湾内部各区域海滩休闲承载能力不均衡;泉州湾海滩休闲承载力的的主要制约因素是水环境污染。     

预应力钢结构拉索参数的研究进展

拉索参数的确定是预应力钢结构的关键问题之一。本文总结了预应力钢结构中拉索关键参数的研究状况,着重分析了存在问题和研究趋势,并结合竖向预应力钢结构体系简要介绍了一种新的拉索参数确定方法。     

浅谈海底电缆的实际应用

文章对海底电缆的用途、种类、应用范围以及关于海底电缆的一些注意事项进行了概述,对海底充油电缆泵站供油系统的应用以及基于琼州海峡的HVAC海底电缆工程的保护方案进行了分析与阐述。