Application of one‐step method to parameter estimation in ODE models

In this paper, we study application of Le Cam's one‐step method to parameter estimation in ordinary differential equation models. This computationally simple technique can serve as an alternative to numerical evaluation of the popular non‐linear least squares estimator, which typically requires the use of a multistep iterative algorithm and repetitive numerical integration of the ordinary differential equation system. The one‐step method starts from a preliminary ‐consistent estimator of the parameter of interest and next turns it into an asymptotic (as the sample size n →∞ ) equivalent of the least squares estimator through a numerically straightforward procedure. We demonstrate performance of the one‐step estimator via extensive simulations and real data examples. The method enables the researcher to obtain both point and interval estimates. The preliminary ‐consistent estimator that we use depends on non‐parametric smoothing, and we provide a data‐driven methodology for choosing its tuning parameter and support it by theory. An easy implementation scheme of the one‐step method for practical use is pointed out.     

To what extent is integration pursued in compulsory planning tools concerning coastal and marine areas? Evidences from two Mediterranean protected areas

Coastal areas are worldwide characterized by multiple pressures generated by high levels of urbanization and by conflictual and inappropriate uses. The establishment of protected areas represents a tool to contrast such pressures. The integration between planning tools represents a key issue, in particular in the Mediterranean area; hence, it has been addressed by both legally binding acts and voluntary agreements and charters concerning coastal zone management as well as marine spatial planning. By looking at two Italian case studies and analyzing their planning documents currently in force, our study aims at assessing the level of integration in relation to planning and management of areas characterized by the coexistence of various nature protection regimes. Our analysis shows that, although integration seems to be a key point in the planning agenda and in spite of some improvements, an integrated management approach in Mediterranean coastal and marine areas is still in its infancy. The results of the analysis show that, rather than contributing to building an integrated approach to marine and coastal zone management, each planning tool focuses on complying with its sectoral, normative framework. This situation can partly be attributed to the multilayered, and complex, Italian framework, characterized by several categories of protected areas with their own legal act and objectives.     

Recreation vs conservation in Natura 2000 sites: a spatial multicriteria approach analysis

Because of its high naturalness and biodiversity, Natura 2000 network (N2K) is becoming increasingly important for recreational opportunity, providing benefits in terms of physical and mental health through outdoor experiences. Nature-based tourism (NBT) is tourism based on the natural attractions of an area: the greater the recreation opportunities, the greater the attractiveness to people. N2K sites are suitable places to favour the development of the NBT, as N2K is not a system of strict nature reserves from which all human activities would be excluded. The approach to conservation and sustainable use of N2K areas is much wider, largely centred on people working with nature rather than against it. To do this, a balance between nature-based tourism development and ecological protection should be reached. In this work, we propose the application of spatial multicriteria analysis, in order to analyse multiple conflicting dimensions interacting over time, considering in particular both criteria related to NBT development and ecological protection. The aim of the work was to analyse the opportunities of Nature-based tourism development in N2K in Umbria, one of the Regions of central Italy, which consists of 102 sites. In particular, the work considered the conditions of biodiversity conservation, flora and fauna, as well as the leisure opportunities provided by the sites and the pressure produced by human activities on them. A spatial multicriteria analysis has been carried out to understand the potentiality of the N2K at territorial level. In particular, the proposed methodology would like to support decision makers in the identification of N2K sites in which NBT activities could be improved and developed, in a balanced way according to biodiversity conservation. Results show, according to preferences set by three different kinds of experts, that only a small bunch of N2K sites could be suitable for an increase of the NBT.     

Economic valuation of climate‐change‐induced vinery landscape impacts on tourism flows in Tuscany

It is widely acknowledged that landscape features can play a major role in determining tourism demand. The present article assesses the impact of vinery landscape and high‐quality wine production on regional tourism flows in Tuscany, an important tourist region in Italy and renowned for its enchanting countryside. Thus, vinery landscape and high‐quality wine production have been included as explanatory variables in our model for tourism flows. This model has been estimated for both international and domestic markets for the whole region of Tuscany. Estimation results confirm that land areas devoted to the production of these superb Tuscan wines, in the particular case of Siena including the Brunello di Montalcino, play an important role in explaining international tourism flows. In this context, we estimate climate‐change‐induced impacts on vinery landscape and quality wines in the tourism sector. These are estimated to cause a loss in the tourism revenues of nearly 15 and 20 million Euros a year, respectively, for 2020 and 2050, for the Tuscany region. Such losses are quite significant, and reiterate the urgency to identify and implement adequate policy options so as to moderate such land use changes, and respective negative welfare impacts.     

Accessing healthy food: availability and price of a healthy food basket in Scotland

Access to healthy food and its marketing have been asserted as limitations on changing behaviour to improve diet. A retailer survey in Scotland is reported that considered availability and affordability of a basket of indicator healthy food items, termed the Healthy Eating Indicator Shopping Basket (HEISB). It comprised 35 items drawn from 5 major food groups. A census of HEISB availability in 466 stores was undertaken in a sample of locations that varied on dimensions of urban-rural and affluent-deprived. Around half of the supermarkets surveyed stocked all the items. Availability of healthy food items was generally seen to be adequate but there were notable variations in availability for specific items. There were large variations in price for the HEISB items across the stores and the survey areas. The total HEISB median price varied by store type. Basket price tended to rise with deprivation with a caveat of the lowest prices in the most deprived areas. Accessibility to a range of healthy food depends more on the presence of medium and large stores than being in a deprived or affluent area.     

CDMA2000 1X网络优化中的掉话故障分析和解决

介绍CDMA2000 1X网络中的掉话机制,重点从弱覆盖,邻区漏配,外部干扰,前反向链路不平衡,搜索窗设置不合理,业务信道发射功率受限等方面分析CDAM2000 1X网络掉话原因和解决方案。     

金安桥水电站计算机监控系统结构及特点

随着国家节能减排战略的全面实施,水电站在电力系统中承担的责任越来越大,装机规模也越来越大。文章从现场工程实施的角度,阐述了作为金沙江中游特大型梯级水电站之一的金安桥水电站计算机监控系统的结构及特点,并分析了该监控系统设计开发的背景、原则及优势。     

An elementary core equivalence theorem¶in a countable economy

We consider an infinite exchange economy with countably many traders, which can be regarded as a natural extension of finite exchange economies to an infinite one. In our countable economy the core defined in the traditional manner would be empty. To avoid this unwanted situation we have to strengthen the notion of “improves upon”. We will achieve this based on the idea that forming coalitions involve costs. Received: 23 August 2000 / Accepted: 12 April 2002 I am very grateful to István Dancs, Péter Medvegyev, Miklós Pintér, Csaba Sándor, András Simonovits, László Szili, Péter Tallos and the anonymous referees for comments and suggestions. Parts of this research were done during the author's Bolyai János Research Fellowship provided by the Hungarian Academy of Sciences (MTA). Of course, all errors remain the author's responsibility.     

SQL Server 2000认证与权限机制及其安全策略初探

数据库系统的安全性、完整性和有效性是数据库研究领域的一个重要课题,本文分析了SQL Server 2000认证与权限的机制,并就此此问题的安全策略作了初步的探讨。