导航卫星阵列天线的快速现场系统校准算法

阵列天线接收处理全球卫星导航信号时,由于天线和射频前端的非理想性,会在不同方向卫星信号中引入不同的载波相位偏差,从而破坏卫星导航接收机距离观测量准确性。针对此问题,提出了一种易实现的卫星导航阵列天线的快速现场系统校准算法。校准过程分为通道校准和天线校准：通过开机和周期进行的通道校准实现阵列天线接收射频前端的通道响应测量;通过与接收处理不同卫星基带数据的数字接收机配合,实现阵列天线的现场阵列流形矢量校准。仿真验证了所提校准算法的正确性和有效性。     

0.5级压力变送器全量程(CMC)表示

在工业生产过程中,会经常用到压力变送器,作为一种比较常用的传感器,在工业生产的很多领域,有着比较广泛的应用。值得注意的是,压力变送器的校准测量工作,比较繁琐和复杂。越来越多的计量部门及校准机构将压力变送器作为国家实验室认可(CNAS)的重点申报项目。本文按照JJG882-2004《压力变送器检定规程》及CNAS-CL07:2011《测量不确定度的要求》内容对0.5级的压力变送器全量程的校准和测量能力(CMC)的表示方式进行阐述。     

船载测控雷达海上无塔校相技术

当前国际商品市场上知识产权产品的平行进口相当普遍,但对平行进口的合法性众说纷纭,至今尚无定论。包括WTO《与贸易有关的知识产权协议》(TRIPs)在内的知识产权国际公约也都未解决这一问题。因此各国只能依据本国的法律加以处理。在知识产权领域,我国虽然已在很短的时间内建立起了较为完善的法律体系,但平行进口方面的立法仍是空白。本文拟分析国际上对知识产权平行进口采取的一些处理原则,进而提出符合我国国情的立法建议。     

Consistent recalibration of yield curve models

The analytical tractability of affine (short rate) models, such as the Vasi?ek and the Cox–Ingersoll–Ross (CIR) models, has made them a popular choice for modeling the dynamics of interest rates. However, in order to properly account for the dynamics of real data, these models must exhibit time‐dependent or even stochastic parameters. This breaks their tractability, and modeling and simulating become an arduous task. We introduce a new class of Heath–Jarrow–Morton (HJM) models that both fit the dynamics of real market data and remain tractable. We call these models consistent recalibration (CRC) models. CRC models appear as limits of concatenations of forward rate increments, each belonging to a Hull–White extended affine factor model with possibly different parameters. That is, we construct HJM models from “tangent” affine models. We develop a theory for continuous path versions of such models and discuss their numerical implementations within the Vasi?ek and CIR frameworks.     

一种用PN码校正相控阵天线通道误差的新方法

为了校准相控阵天线通道间幅相误差,实现精确的数字波束形成,给出了一种用伪噪声序列（PN）码作为校准测试信号的在线校准方法（校准和通信可同时进行）。该方法由特定的校准站发送校准测试信号,被天线各阵元接收,并通过存在误差的各通道,在接收端用与发端相同的PN码作为本地信号与接收信号逐通道做相关运算,对各通道的相关峰值做比较可求出校准矢量进而完成校准。仿真结果表明,该方法可以有效校准相控阵天线通道间的幅相误差,校准后的波束方向图接近理想的波束方向图。     

Integrating Agri-Environmental Programs into Regional Production Models: An Extension of Positive Mathematical Programming

Positive Mathematical Programming (PMP) has become a popular method for regional production models. The standard approach estimates cost (or production) functions for each land-use activity separately from each other. This means that the same crop grown under two technologies is treated as if it were two separate crops, which may lead to unsatisfying results, for example, if agri-environmental programs are modeled. We present an extended version of PMP that leads to more plausible results than the standard version in such cases. The extended method is applicable to other problems where differences in the elasticity of substitution between activities are important.     

TD多通道拉远系统校准方案及算法

在TD(Time Division duplex,时分双工)多通道射频拉远通信系统中,对各通道的时延、相位、幅度分别进行校准是其关键技术。本文先介绍了校准的基本原理,接着阐述了校准的流程,最后分析了相关峰的算法。该算法能校准通道之间的时延、相位和幅度误差,具有较好的性能。     

博弈论在企业应收账款中的应用分析

在激烈的市场竞争中,赊销作为一种销售策略普遍存在。文章就企业与竞争对手之间的"囚徒困境"博弈,分析了应收账款的产生背景和企业选择赊销的被迫性,进而通过企业与客户之间的相机决策博弈,构建模型,在动态的博弈中,依次剖析了企业赊销的选择前提和应收账款的后续管理策略。     

Empirical factor demands and flexible functional forms: a bayesian approach

In this paper we compare classical econometrics, calibration and Bayesian inference in the context of the empirical analysis of factor demands. Our application is based on a popular flexible functional form for the firm's cost function, namely Diewert's Generalized Leontief function, and uses the well-known Berndt and Wood 1947–1971 KLEM data on the US manufacturing sector. We illustrate how the Gibbs sampling methodology can be easily used to calibrate parameter values and elasticities on the basis of previous knowledge from alternative studies on the same data, but with different functional forms. We rely on a system of mixed non-informative diffuse priors for some key parameters and informative tight priors for others. Within the Gibbs sampler, we employ rejection sampling to incorporate parameter restrictions, which are suggested by economic theory but in general rejected by economic data. Our results show that values of those parameters that relate to non-informative priors are almost equal to the standard SUR estimates, whereas differences come out for those parameters to which we have assigned informative priors. Moreover, discrepancies can be appreciated in some crucial parameter estimates obtained with or without rejection sampling.     

Valuation on the Frontier: Calibrating Actual and Hypothetical Statements of Value

The lack of robust evidence showing that hypothetical behavior directly maps into real actions remains a major concern for proponents of stated preference nonmarket valuation techniques. This article explores a new statistical approach to link actual and hypothetical statements. Using willingness-to-pay field data on individual bids from sealed-bid auctions for a $350 baseball card, our results are quite promising. Estimating a stochastic frontier regression model that makes use of data that any contingent valuation survey would obtain, we derive a bid function that is not statistically different from the bid function obtained from subjects in an actual auction. If other data can be calibrated similarly, this method holds significant promise since an appropriate calibration scheme, ex ante or ex post , can be invaluable to the policy maker that desires more accurate estimates of use and nonuse values for nonmarket goods and services.