The Governance of Rural Land in a Liberalised World

Liberalisation of agricultural policies reduces the influence of policy on land‐use decisions, but environmental policy objectives remain. Governance provides an approach that recognises the role of institutions and collective action. The formulation of environmental policy objectives in terms of the provision of public goods raises questions as to the role of economic valuation and as to whether the definition of ‘goods’ may misdirect policy attention. An alternative approach relates to ecosystem services and sees management issues in terms of ecosystem resilience and the adaptive governance of socio‐ecological systems. Governance involves a mix of regulation, markets, government incentives and collective action. Regulation sets the domain within which markets operate and social judgements as to property rights are required as a basis for exchanges. Depending on commodity prices, agri‐environment schemes may be required either to reduce agricultural production intensity or to keep land under production. The diffuse nature of the environmental benefits and costs of land uses, the complexity of ecosystems and the need to co‐ordinate land management decisions indicate a role for local adaptive co‐management of land resources. Governments play a major role in supporting the institutional framework within which this can take place.     

亚洲“四小”对外投资的三大热点简析

近年来,特别是进入九十年代后,随着亚太地区新的产业分工格局的形成,以及处于转型期经济的结构调整,亚洲“四小”的对外直接投资迅速扩大,东南亚地区、苏联与东欧及中国内地则成为它们投资的三大热点,日益为世人所瞩目。一、第一大热点:东南亚地区亚洲“四小”的对外直接投资始于六十年代前后。六十年代至七十年代初,它们的对外直接投资基本上集中在东南亚地区,七十年代中期以后逐步转向以美国为主的西方国家。     

Learning in linear models with expectational leads

Models with expectational leads typically admit multiple rational expectations solutions. Based on the ordinary least-squares algorithm, this paper provides an adaptive learning scheme which allows a forecasting agent to select a particular solution on economic grounds. Conditions are given under which this scheme converges to rational expectations solutions globally for all initial conditions. We strengthen convergence results in relaxing standard assumptions and in providing conditions ensuring algorithm convergence which are easier to verify and to interpret than those previously known.     

移动通信中的空分多址技术

在信息时代，人们对通信业务的需求不断增加，这对通信技术提出了更高的要求，空分多址（SDMA）技术由于其在提高系统容量和频谱利用率方面的独特优势而引起了人们的广泛关注。本文从基本概念、信道模型、系统实现和对通信系统的性能改善等几个方面对空分多址技术进行了较为全面的论述。     

空载雷达杂波抑制自适应阵列技术

文中对一个采用联合局域化－通用似然比准则的自适应阵列雷达与一个采用相移中心孔径（ＤＰＣＡ）技术的雷达作了比较。对目标的实验结果表明，在严重的非均匀杂波及干扰环境中，普通的自适应处理技术是不适用的。     

寡头垄断市场竞争博弈学习模型的研究

有限理性参与者之间的博弈问题是人们十分关注的研究项目。目前已提出了一些博弈学习模型，但都存在一定的局限性。基于模拟退火算法，给出了博弈学习的一个改进方法，建立了寡头垄断市场的博弈学习模型。计算机仿真实验表明，新的博弈学习方法的有效性有了很大的提高。     

反Hook技术的虚核保护机制研究

现有的基于虚拟机的反逆向工程技术,采用静态的虚拟指令集对受保护软件核心代码进行转换。然而,固定不变的静态指令长期使用,既不利于保持软件安全的可靠性,又不能对不同类型的受保护软件进行优化,以提高解释执行的效率。本文在基于虚拟机的保护机制基础上,提出一种基于自适应动态指令集的虚核保护机制,实验表明,该虚核对软件保护的安全性和执行效率有了进一步的提高。     

应用于自适应格型RLS滤波器的变阶数算法

提出了一种新的变阶数(或抽头长度)算法,并将之应用于变阶数自适应格型递归最小二乘(RLS)滤波器的阶数更新中,讨论了格型滤波器阶数更新时相关参数的调整方法.新算法以分贝的形式比较短滤波器与长滤波器的时平均平方误差,采用自适应的抽头长度步长,能够在滤波器权值末收敛时同时快速更新滤波器长度与权值,且在不同大小噪声条件下都能收敛到最优阶数.理论分析与不同大小噪声条件下的自适应系统辨以仿真结果验证了新算法的有效性.     

People,institutions, and technology: A personal view of the role of foundations in international agricultural research and development 1960–2010

In the 1940 and 1950s, the Rockefeller and Ford Foundations initiated overseas rural and agricultural development activities in a number of countries in Asia and Latin America. They began with country programs. These programs often involved creating new institutions in the recipient countries, and while the perspective was long term – as long as it took to achieve program goals – the foundations also explicitly sought to work themselves out of a job and turn over responsibility to nationals. By 1960 the two foundations had moved beyond national assistance programs to invent a new model, the international agricultural research center, designed to improve the lives of poor rural people by increasing the productivity of developing world agriculture. Some of the national programs were morphed into international centers. The international agricultural research centers proved attractive to other donors and by the 1970s international agricultural research had become institutionalized in the form of the CGIAR and its associate centers. The 1960s India agricultural program of the Rockefeller Foundation comprised a team of about a dozen American scientists working in India assisting Indian scientists to invent new approaches to agricultural technology development. At the same time and also in India, the Ford Foundation pioneered the integrated rural development model. By the mid-1970s integrated rural development projects were the approach of choice for many donors. In the 1980s the Ford Foundation moved away from agriculture concentrating on broader social issues; the Government of India and Rockefeller Foundation decided Foundation scientists had, indeed, worked themselves out of their jobs and Rockefeller’s India program was effectively closed down, although by then the international agricultural research centers, including ICRISAT in India, had attained a degree of maturity and stability. The Rockefeller Foundation invented another new model for agricultural research in the 1990s – the international rice biotechnology network, in which leading scientists from Asian countries, Western countries and the international centers worked together within a framework managed by Rockefeller scientists. In 2006, the Bill Melinda Gates Foundation entered the global agricultural scene in partnership with the Rockefeller Foundation to establish AGRA, yet another new model. By 2010 the Gates Foundation was annually spending about 10 times     

GPS卫星接收机的自适应抗干扰设计

提出了一种加强GPS卫星接收机抗干扰能力的技术实现方案,采用自适应调零技术以及天线阵的具体实现方式来消除干扰。文中还对自适应天线阵所采用的功率倒置的算法做了详细说明,并进行了计算机仿真。