基于Qt Test的自动化单元测试

Qt是跨平台的应用软件开发框架,Qt Test是Qt框架的单元测试库。基于Qt Test的单元测试可以进行功能和性能测试。持续集成系统可以自动化单元测试的构建、部署、运行和结果统计过程。工程实践表明:基于Qt Test的单元测试与持续集成系统的结合可以降低软件的缺陷率,优化软件架构的设计,提高软件工程的自动化。     

软件单元测试及测试用例设计

单元测试是针对各功能模块的进行测试,进行充分的单元测试,是提高软件质量,降低研发成本的必由之路。文章对软件测试和单元测试相关概念做了简要说明,以用户注册模块出生年月日的检验为例,说明了用例设计的过程。     

面向对象的软件测试

面向对象软件测试技术的研究是面向对象开发方法不可缺少的一环,对软件质量和软件重用至关重要。传统的测试技术已经无法有效地进行测试。本文对面向对象软件测试技术进行了分析,剖析了面向对象自动潮试框架,采用VSS(版本控制)+Ant(项目管理)+JUnit(集成测试)的模式实现了一个面向对象的自动化测试。     

web性能测试研究

本文通过对网上web的订餐系统进行测试,通过设计测试方案,对程序进行系统的单元测试,收集测试数据,对测试数据进行分析等手段,最终生成相关资料及最终测试报告,探讨了软件测试技术在Web中的研究和实现。     

中文语法自动纠错系统的研究与实现

文章将从中文语法错误修正中进行解释,主要包括以下几个部分:①语料库的编写,基于高质量的汉语语料库,通过机器学习进行语法错误特征分析和语料库纠错方法,基于模型进行训练;②预处理数据,消除数据噪声,从而获得高质量的数据;③语法错误,句子分割前的自动分割和词性标注,通过提高分词的正确性来提高语法错误识别的准确性;④建立N-Gram模型并基于CRF模型检测语法错误。     

一部手机的“旅程”

做个手机容易吗？不容易，真的，你看看我下面一路的“旅程”就知道了。其实，这还不是我全部的行程，仅仅只是我硬件测试中的一部分，我还有单元测试、集成测试、系统测试、一致性测试等等。这趟“旅程”是我和我的兄弟姐妹们一起“出行”的。对了，我们叫手机，姓“中兴”。     

“Feed”爆发

Feed广告恰恰可以轻松融入移动互联网,并可根据用户属性进行精准匹配,大大提高广告转化率。今年1月,微信在朋友圈以"Feed"信息流的形式投放了首批广告,包括VIVO智能手机、宝马和可口可乐三个品牌。微信官方数据显示,仅VIVO品牌在一天半的时间内,直接总曝光量就已接近1.55亿。直接曝光之外,这次推荐还引发了用户晒广告的转发热潮,增加了大量的额外曝光,甚至还诱发了很多个人用户"以假乱真"的山寨广告传播,十分疯狂。对此,宣亚传播副总裁吴卫华认为,微信     

空气焓差法测量不确定度计算和分析

基于公司现有焓差试验台制冷量测试原理,编写焓差法制冷量/制热量计算软件,在软件的基础上建立和分析焓差法测量不确定度。为制冷量和制热量的测试分析和测量不确定度的评定提供参考。     

多路以太网数据采集系统设计

随着科技的不断发展,工业控制逐步向智能化,网络化和集成化发展,数据采集与监控在远距离数据传输以及工业数据采集中的要求越来越高。文章就以远程数据采集展开研究并设计多路以太网数据采集卡,充分利用远程资源,实现远程数据采集。本系统采用STM32F系列单片机作为控制系统的核心,数据对象为模拟电压信号,通过12位高精度模数转换器将信号转换为数字信号,并经以太网传输至计算机,在计算机上位机显示并处理。从而实现了基于以太网的远程数据采集。数据从下位机网卡(ENC28J60)发出,经以太网传输至PC机网卡,最终由VB编写的以太网客户端拨号链接下位机服务器实现数据的采集并显示,测试结果理想。     

基于Wincon8731的船舶设备远程监测系统的实现

详细介绍了利用Wincon8731来构建船舶设备远程监测系统。用VB.NET语言来编写基于Windows ce.net平台的数据采集及处理程序,并通过iPush Server软件实现数据的远程交换,使系统具备了本地运算、本地存储、数据主动交换及远程程序更新等功能,最终实现了船舶设备的远程实时监测。     

A Comparative Study of Unit Root Tests with Panel Data and a New Simple Test

The panel data unit root test suggested by Levin and Lin (LL) has been widely used in several applications, notably in papers on tests of the purchasing power parity hypothesis. This test is based on a very restrictive hypothesis which is rarely ever of interest in practice. The Im–Pesaran–Shin (IPS) test relaxes the restrictive assumption of the LL test. This paper argues that although the IPS test has been offered as a generalization of the LL test, it is best viewed as a test for summarizing the evidence from a number of independent tests of the sample hypothesis. This problem has a long statistical history going back to R. A. Fisher. This paper suggests the Fisher test as a panel data unit root test, compares it with the LL and IPS tests, and the Bonferroni bounds test which is valid for correlated tests. Overall, the evidence points to the Fisher test with bootstrap-based critical values as the preferred choice. We also suggest the use of the Fisher test for testing stationarity as the null and also in testing for cointegration in panel data.     

基于Sieve Bootstrap方法的季节时间序列模型检验问题研究

研究目标：完善季节时间序列模型建模理论,解决建模过程烦琐、各类检验方法的结论差异大以及模型误设定问题。研究方法：基于对各季节时间序列模型的数理分析及比较,提出合理的模型检验程序;再运用Sieve Bootstrap方法,给出季节性单位根检验及确定性季节过程检验的统计量的临界值,并比较基于Sieve Bootstrap的检验方法与HEGY检验、BT检验的异同。研究发现：本文提出的检验程序能有效识别模型,检验统计量有限样本性质优良;实证分析表明,本文提出的检验程序及方法能更有效地识别中国宏观经济数据中的季节性。研究创新：将Sieve Bootstrap方法应用于季节时间序列的平稳性检验及趋势性检验中。研究价值：提出季节时间序列模型检验程序及检验方法,促进其在季节性经济数据中的应用。     

Testing for a unit root in the volatility of asset returns

It is now well established that the volatility of asset returns is time varying and highly persistent. One leading model that is used to represent these features of the data is the stochastic volatility model. The researcher may test for non-stationarity of the volatility process by testing for a unit root in the log-squared time series. This strategy for inference has many advantages, but is not followed in practice because these unit root tests are known to have very poor size properties. In this paper I show that new tests that are robust to negative MA roots allow a reliable test for a unit root in the volatility process to be conducted. In applying these tests to exchange rate and stock returns, strong rejections of non-stationarity in volatility are obtained. Copyright © 1999 John Wiley & Sons, Ltd.     

Multiple Testing for No Cointegration under Nonstationary Volatility

With cointegration tests often being oversized under time‐varying error variance, it is possible, if not likely, to confuse error variance non‐stationarity with cointegration. This paper takes an instrumental variable (IV) approach to establish individual‐unit test statistics for no cointegration that are robust to variance non‐stationarity. The sign of a fitted departure from long‐run equilibrium is used as an instrument when estimating an error‐correction model. The resulting IV‐based test is shown to follow a chi‐square limiting null distribution irrespective of the variance pattern of the data‐generating process. In spite of this, the test proposed here has, unlike previous work relying on instrumental variables, competitive local power against sequences of local alternatives in 1/T‐neighbourhoods of the null. The standard limiting null distribution motivates, using the single‐unit tests in a multiple testing approach for cointegration in multi‐country data sets by combining P‐values from individual units. Simulations suggest good performance of the single‐unit and multiple testing procedures under various plausible designs of cross‐sectional correlation and cross‐unit cointegration in the data. An application to the equilibrium relationship between short‐ and long‐term interest rates illustrates the dramatic differences between results of robust and non‐robust tests.     

基于MIMU的车速测量方案研究

分析了车辆装备底盘性能测试对运动参数测量的特点和要求,提出了利用MIMU单独工作进行车速测量的方案,以MIMU(MEMS Inertial measurement unit)为主要单元,以小型蓄电池作为供电源,通过USB-RS422转换接头,从USB口连接到笔记本电脑,从而获得计算的基本数据。给出了车速测量系统的安装调整和速度及位移的计算思路,明确了实现工程化应用还需深入进行的工作。     

一种基于Android系统的嵌入式数据库同步方案

近年来,无线应用业务迅速发展,大大地丰富了人们的沟通和生活方式。本文作者结合基于Android系统的应用软件开发,介绍了服务器数据库与客户端SQLite数据库的一种同步方案。其中涉及到XML、Java DOM等基本技术。     

Unit root testing under a local break in trend

Recent approaches to testing for a unit root when uncertainty exists over the presence and timing of a trend break employ break detection methods, so that a with-break unit root test is used only if a break is detected by some auxiliary statistic. While these methods achieve near asymptotic efficiency in both fixed trend break and no trend break environments, in finite samples pronounced “valleys” in the power functions of the tests (when mapped as functions of the break magnitude) are observed, with power initially high for very small breaks, then decreasing as the break magnitude increases, before increasing again. In response to this problem, we propose two practical solutions, based either on the use of a with-break unit root test but with adaptive critical values, or on a union of rejections principle taken across with-break and without-break unit root tests. These new procedures are shown to offer improved reliability in terms of finite sample power. We also develop local limiting distribution theory for both the extant and the newly proposed unit root statistics, treating the trend break magnitude as local-to-zero. We show that this framework allows the asymptotic analysis to closely approximate the finite sample power valley phenomenon, thereby providing useful analytical insights.     

基于B/S结构医院药库信息系统的实现

本文主要描述B/S结构医院药库信息系统的实现,包括系统的主要功能和具体的实现方法。系统基于J2EE企业级开发平台,利用现有流行的集成开源框架,采用四层结构来实现,其中表示层、控制层、业务逻辑层采用标准的MVC模式Struts框架来实现,数据持久层采用Hibernate框架。该结构不仅使系统结构清楚、可维护性强,而且大大增强了代码的可读性和可重用性。     

Relative Efficiency of the Fuzzy p-Value Approach to Hypothesis Testing

In missing data problems, it is often the case that there is a natural test statistic for testing a statistical hypothesis had all the data been observed. A fuzzy  p -value approach to hypothesis testing has recently been proposed which is implemented by imputing the missing values in the "complete data" test statistic by values simulated from the conditional null distribution given the observed data. We argue that imputing data in this way will inevitably lead to loss in power. For the case of scalar parameter, we show that the asymptotic efficiency of the score test based on the imputed "complete data" relative to the score test based on the observed data is given by the ratio of the observed data information to the complete data information. Three examples involving probit regression, normal random effects model, and unidentified paired data are used for illustration. For testing linkage disequilibrium based on pooled genotype data, simulation results show that the imputed Neyman Pearson and Fisher exact tests are less powerful than a Wald-type test based on the observed data maximum likelihood estimator. In conclusion, we caution against the routine use of the fuzzy  p -value approach in latent variable or missing data problems and suggest some viable alternatives.