60GHz无线局域网低成本毫米波频率源的设计

设计了一种低成本高性能的锁相倍频60GHz毫米波频率源，用于室内超宽带无线局域网的高速无线通信系统。频率源由Ku波段锁相频率源经4倍频网络得到55-58GHz工作频率，Ku波段采用混频锁相方法获得毫米波频段优良的相位噪声特性。最小跳频间隔7．5MHz，频率过渡时间小于100μs，相位噪声优于-75dBcHz@100kHz，杂散优于一45dBc。     

Incentive compatibility constraints and dynamic programming in continuous time

This paper is devoted to the study of infinite horizon continuous time optimal control problems with incentive compatibility constraints that arise in many economic problems, for instance in defining the second best Pareto optimum for the joint exploitation of a common resource, as in Benhabib and Radner [Benhabib, J., Radner, R., 1992. The joint exploitation of a productive asset: a game theoretic approach. Economic Theory, 2: 155–190]. An incentive compatibility constraint is a constraint on the continuation of the payoff function at every time. We prove that the dynamic programming principle holds, the value function is a viscosity solution of the associated Hamilton–Jacobi–Bellman (HJB) equation, and that it is the minimal supersolution satisfying certain boundary conditions. When the incentive compatibility constraint only depends on the present value of the state variable, we prove existence of optimal strategies, and we show that the problem is equivalent to a state constraints problem in an endogenous state region which depends on the data of the problem. Some economic examples are analyzed.     

300MW机组凝结泵变频改造

本文主要研究了蒙西发电厂转动设备变频节电技术的关键技术。包括:高压变频器原理,高压变频器变频调速方案。最后将高压变频器技术应用于#1机A、B凝结水泵电机变频改造中。     

调频诱饵干扰技术

传统的拖曳式雷达有源诱饵对抗导引头跟踪系统，其干扰效能受到限制。提出一种新型诱饵干扰形式，利用频率调制技术对导引头跟踪系统实施欺骗性干扰，并给出相关的系统模型和干扰理论。计算机仿真证明了其良好的干扰效能。     

PERIODICITIES OF FOREIGN EXCHANGE MARKETS AND THE DIRECTIONAL CHANGE POWER LAW

This paper utilizes advanced methods from Fourier analysis in order to describe periodicities in financial ultrahigh frequency foreign exchange data. The Lomb–Scargle Fourier transform is used to take into account the irregularity in spacing in the time domain. It provides a natural framework for the power spectra of different inhomogeneous time‐series processes to be easily and quickly estimated. Furthermore, an event‐based approach in intrinsic time based on a power‐law relationship is employed using different event thresholds to filter the foreign exchange tick‐data. The calculated spectral density demonstrates that the price process in intrinsic time contains different periodic components for directional changes, especially in the medium–long term, implying the existence of stylized facts of ultrahigh frequency data in the frequency domain. Copyright © 2013 John Wiley & Sons, Ltd.     

Major World Equity Market Interdependence a Decade After the 1987 Crash: Evidence From Cross Spectral Analysis

Several studies have focused on the pre- post-October 1987 crash. Results indicate that major market equity correlations rose during the crash period. Cross spectral analysis is applied to six of the G-7 markets to determine whether frequency domain correlations have increased post-crash relative to the pre-crash period. The results indicate that correlations have increased for most of the markets studied. Most striking are the increased post-crash correlations among the three European markets, in light of the European Union. Additional evidence shows mixed results regarding frequency domain phase leads among the markets.     

Kerr型介质的增益与光束小扰动空间频率的关系

应用Bespalov-Tanalov理论，分析了克尔型放大介质中光束小扰动演化特性，研究了小扰动空间频率与介质长度及增益系数的关系．     

Conducting Online Surveys

The World Wide Web (WWW) is increasingly being used as a tool and platform for survey research. Two types of electronic or online surveys available for data collection are the email and Web based survey, and they constitute the focus of this paper. We address a multitude of issues researchers should consider before and during the use of this method of data collection: advantages and liabilities with this form of survey research, sampling problems, questionnaire design considerations, suggestions in approaching potential respondents, response rates and aspects of data processing. Where relevant, the methodological issues involved are illustrated with examples from our own research practice. This methods review shows that most challenges are resolved when taking into account the principles that guide the conduct of conventional surveys.     

Correcting for On-Site Sampling in Random Utility Models

This study demonstrates how the joint distribution of a set of conditional trip counts to a system of recreation-sites can be adjusted for on-site sampling. An econometric approach is proposed that addresses both the size-biased distribution of the sampled visits and the weighted distribution of reported visits to ancillary destinations in a multivariate random utility framework. Estimation results indicate that uncorrected models produce biased estimates of trip counts and welfare measures. The empirical application examines jet skiing in the Lake Tahoe region.     

Optimal Fiscal Policies,Congestion and Over‐entry*

By shedding light on market imperfections and the congestion of public goods, we show that free entry in a market equilibrium will lead to excessive entry relative to the social optimum. Moreover, by specifying a generalized congestion function, it is also shown that different fiscal policies, including labor income tax, capital income tax and government expenditure, play a distinct role in terms of remedying market distortions. Specifically, optimal income taxes decrease with the degree of market imperfections in order to remove the monopoly inefficiency, while they increase with the degree of congestion in order to remedy the adverse externality caused by congestion distortion. Since a higher degree of increasing returns to an expansion in the variety of intermediate goods is found to intensify the congestion effect of government infrastructure expenditure, the optimal rule of government expenditure proposed by Barro (1990) should be modified.