一种高集成度吸排油烟机监控器的实现

描述了作者设计的一种用于全自动吸排油烟机专用集成电路控制器的自动报警、自动监控、延时开关等功能，给出了该专用集成电路的典型应用电路及操作方法．该电路具有价格低廉、外部元件少等特点．     

论便携式智能设备的低功耗设计

低功耗是便携式智能设备设计中应当遵守的一条重要原则。对单片机产品开发工作中的作法和经验，以及有关资料介绍的一些措施，进行了分析、归纳和总结，提出了从系统方案的拟定、电路设计、元器件选取到软件设计各主要环节应当遵守的一般准则。     

On the use of the t-statistic in preliminary testing procedures for the Behrens-Fisher problem

Preliminary testing procedures for the two means problem traditionally employ the pooled variance t-statistic. In this paper we show that bias of the t-statistic under conditions of heterogeneity of variance may be increased if use of the t-statistic is conditional on an affirmative F-test. For this reason we conclude that use of the t-statistic in preliminary testing procedures is inappropriate.     

Antipodally symmetric distributions for orientation statistics

The conventional antipodally symmetric Bingham matrix distribution on the Stiefel manifold is generalized. Large sample maximum likelihood estimation and uniformity tests are discussed, and a parametric model for axial orientations (X-shapes) is suggested. A generalization of the Khatri-Mardia matrix distribution is developed to provide a model suitable for hybrids (T-shapes).     

Fixed‐Smoothing Asymptotics in a Two‐Step Generalized Method of Moments Framework

This paper develops the fixed‐smoothing asymptotics in a two‐step generalized method of moments (GMM) framework. Under this type of asymptotics, the weighting matrix in the second‐step GMM criterion function converges weakly to a random matrix and the two‐step GMM estimator is asymptotically mixed normal. Nevertheless, the Wald statistic, the GMM criterion function statistic, and the Lagrange multiplier statistic remain asymptotically pivotal. It is shown that critical values from the fixed‐smoothing asymptotic distribution are high order correct under the conventional increasing‐smoothing asymptotics. When an orthonormal series covariance estimator is used, the critical values can be approximated very well by the quantiles of a noncentral F distribution. A simulation study shows that statistical tests based on the new fixed‐smoothing approximation are much more accurate in size than existing tests.     

反哺农业:寻求社会公平发展的有效途径

文章提出“三农”问题的实质是现代化过程中农民与其他社会利益主体之间的利益关系。目前,我国已进入工业反哺农业的时代。通过构建农村公共服务体系,实现城乡社会公平发展;依靠乡镇企业发展,实现劳动力转移促农,农产品加工和产业化经营促农;建农补农实现反哺促农;小城镇建设与乡镇企业发展相互促进实现以城带乡促农。     

基于产业示范站的科技扶贫模式及其减贫效应

探索促进区域经济增长和贫困人口减贫相结合的科技扶贫模式,是我国目前精准扶贫战略实施的重点。以西北农林科技大学产业示范站科技扶贫模式为例,从理论层面分析了其减贫机制,并运用陕西省3个国家扶贫开发重点县748份微观农户调研数据,实证检验了科技扶贫的减贫效应。研究发现:(1)产业示范站科技扶贫模式具有显著减贫效应,即农户通过参与农业科技培训、主导产业示范、农业信息服务和产业组织化带动4种扶贫方式,不仅能提高其家庭农业收入,也能降低家庭贫困发生的概率;(2)不同科技扶贫方式的减贫效应存在显著差异,其中农业科技培训的减贫效应较为突出,而农业信息服务的减贫效应有待进一步提升;(3)建档立卡贫困户科技扶贫参与度低于非贫困户。因此,地方政府应加大财政支持与组织保障的力度,引导高校优势科技资源与贫困地区特色产业精准对接,借鉴“西农模式”为深入推进区域精准扶贫战略提供科技支撑。     

MANAGING CREDIT BUBBLES

We study a dynamic economy where credit is limited by insufficient collateral and, as a result, investment and output are too low. In this environment, changes in investor sentiment or market expectations can give rise to credit bubbles, that is, expansions in credit that are backed not by expectations of future profits (i.e., fundamental collateral), but instead by expectations of future credit (i.e., bubbly collateral). Credit bubbles raise the availability of credit for entrepreneurs: this is the crowding‐in effect. However, entrepreneurs must also use some of this credit to cancel past credit: this is the crowding‐out effect. There is an “optimal” bubble size that trades off these two effects and maximizes long‐run output and consumption. The equilibrium bubble size depends on investor sentiment, however, and it typically does not coincide with the “optimal” bubble size. This provides a new rationale for macroprudential policy. A credit management agency (CMA) can replicate the “optimal” bubble by taxing credit when the equilibrium bubble is too high and subsidizing credit when the equilibrium bubble is too low. This leaning‐against‐the‐wind policy maximizes output and consumption. Moreover, the same conditions that make this policy desirable guarantee that a CMA has the resources to implement it.