FREQUENCY DOMAIN TESTS OF MULTIVARIATE GAUSSIANITY AND LINEARITY

A stationary multivariate time series { X _t } is defined as linear if it can be written in the form X _t = ∑^∞ _{j =−∞} A _j e _{t − j} where A _j are square matrices and e _t are independent and identically distributed random vectors. If the e _t } are normally distributed, then { X _t is a multivariate Gaussian linear process. This paper is concerned with the testing of departures of a vector stationary process from multivariate Gaussianity and linearity using the bispectral approach. First the definition and properties of cumulants of random matrices are used to obtain the expressions for the higher-order cumulant and spectral vectors of a linear vector process as defined above. Then it is shown that linearity of a vector process implies constancy of the modulus square of its normalized higher-order spectra whereas the component of such a vector process does not necessarily have a linear representation. Finally, statistics for the testing of multivariate Gaussianity and linearity are proposed.     

Coverage path planning for eddy current inspection on complex aeronautical parts

Non-destructive testing (NDT) plays a critical role in controlling the structural integrity (therefore the quality) of aeronautical parts, during fabrication as well as during maintenance. Eddy current (EC) testing is one of the most used NDT techniques in the aerospace industry. However, EC testing is still mainly performed by human operators and reliability as well as repeatability is not always guaranteed. To solve these issues, automating this NDT technique with a robotic system is investigated. In this paper, an EC probe equipped with a passive compliant system is assumed to be attached to the end-effector of a 6-DOF manipulator arm to carry on the inspection. Then, assuming that a 3D model of the inspected part is known a priori, a coverage path planning method using a zigzag (or rastering) pattern adapted to EC testing on aeronautical structures with a complex geometry is proposed. To reach this objective, the approach adopted in this work is to adapt existing coverage path planning techniques based on a “divide-and-conquer” strategy used for spraying applications to EC inspection. More precisely, three successive segmentations are applied to the surface to be inspected so that consistent rastering paths can be generated. Simulation results are shown for a complex part of an aeronautical structure to demonstrate the efficiency of the proposed method.     

Automating Test Case Selection in Model-Based Software Product Line Development

We address the problem of how to select test cases for products in a controlled model-based software product line development process. CVL, the common variability language, gives a framework for materialisation of product models from a given base model, variability model and resolution model. From such product models, software products can be derived. In practise, test case development for the product line often is independent from the product development. Therefore, the problem arises which test cases can be applied to which products. In particular, the question is whether a test case for one speci c product can be also used for a "similar" product. In this paper, we show how the expected outcome of a test case to a product in a model-based software product line development can be determined. That is, we give a procedure for assigning the outcome of a given test case on an arbitrary member of a software product line. We recall the relevant de nitions for software product line engineering, describe our approach, and demonstrate it with the example of a product line of super-automatic espresso machines.     

化肥企业质检机构的管理

针对我国化肥生产企业质检机构的现状 ,结合国家相关政策的要求 ,就如何搞好化肥企业质检机构的管理提出了诸多指导性意见     

Gquest: Modeling patient questionnaires and administering them through a mobile platform application

Background

The use of surveys is becoming popular in the health care industry for acquiring information useful to the accomplishment of several studies. Besides their exploitation on a large scale for conducting epidemiological studies, surveys are being increasingly carried out on a narrower perspective through the administration of questionnaires aimed at assessing the quality of life perceived by patients or their clinical status during mid- or long-term treatments. This is useful for managing resources or optimizing and individualizing treatments.

Objectives

This paper describes Gquest, a platform for modeling, generating and administering questionnaires through mobile devices such as smartphones or tablets. Gquest was motivated by the need of administering questionnaires during home treatments, albeit its applicability is rather general. The main requirement was to have a very simple, clean and easy to use platform able to support (a) physicians in the design and delivery of questionnaires and (b) outpatients in sending self-recorded outcomes to the clinical staff.

Methods

Gquest has two basic components. The first one is a model devised for representing questionnaires which is extremely flexible. It allows the generation of questions and answers of different types, supports adaptivity in the dialog with the user and enforces simple consistency rules for checking his input. The second component is an application able to run instances of those questionnaires. It downloads questionnaires over the air in terms of XML files from a server and stores them locally into the mobile repository. Questionnaires become then available to the user, who in our case is a patient or one of his relatives. The user can select which one to fill-in, according to his needs and/or the specific treatment protocol. The selected questionnaire may be filled-in all at once or be completed in subsequent steps over time since any input provided is persisted on a local database. Finally, when a questionnaire is closed all the answers are transparently synchronized to a server for further evaluation or statistical purposes.

Results

The platform has been exploited and tested in two medical domains where questionnaires have very different purposes; a quality of life pilot survey involving patients with atrial fibrillation within the EU-funded project MobiGuide, and an investigation of the users’ needs during the requirements elicitation phase of a telemedicine project for the safe discharge of fragile patients.

Conclusions

Gquest proved to be a suitable tool for dealing with a wide variety of question types and has been positively accepted by the patients enrolled in the pilot study.     

列车用CAN协议一致性测试平台的设计与实现

列车用CAN总线协议一致性测试是保证不同设备制造厂家生产的CAN通信设备之间实现互联、互通和互操作的前提。在对协议一致性测试原理和CAN总线协议特点进行简要分析的基础上,提出了针对CAN总线协议一致性测试的协同测试方法和相应的一致性测试内容,设计并构建了相应的一致性测试硬件平台,并对测试软件平台中可执行测试实例产生、测试执行、测试评估以及测试管理等诸多环节所涉及的基本功能软件进行了设计和实现,完成了CAN协议一致性测试的基本功能。实际运行和测试结果表明：所设计的测试平台达到了预期结果,为下一步列车用CAN总线协议的一致性测试打下了基础。     

二斑叶螨和朱砂叶螨对常用杀螨剂的敏感性比较

采用玻片浸渍法和叶片残毒法，选用哒螨灵等6种常用杀螨剂对二斑叶螨和朱砂叶螨进行了毒力测定。结果表明，6种供试药剂对二斑叶螨的卵和雌成螨的LC50均明显大于朱砂叶螨，说明二斑叶螨较朱砂叶螨对供试药剂有更强的耐药性。其中，两种害螨对噻螨酮的敏感性差异相对较小，而对喹螨醚、哒螨灵和阿维菌素等其它药剂的敏感性差异很大。     

热电偶动态响应测试系统

在大型船舶发动机中,高温环境下其齿轮、轴承等部件的温度是发动机运行中必须监控的数据,对于此类动态温度测量,通常选用动态响应时间短的温度传感器进行测量。为实现温度传感器动态响应时间的准确检测,设计了热电偶动态响应测试系统,以检测热电偶动态响应特性,并对影响系统测量精度的因素进行了分析。实验结果表明:动态响应测试系统性能稳定,测试结果准确可靠。     

基于仿真卡的通用1553B总线测试软件设计

1553B总线通信是航天器终端设备的重要功能,在研制各阶段,对设备的总线通信功能进行测试是必不可少的。基于总线仿真卡进行二次开发,提出一种通用1553B总线测试软件设计方法,采用总线消息描述文件和设备参数描述文件分别描述总线消息和设备参数,设计通用程序模块,使软件代码不依赖总线消息或设备参数的具体定义。所述方法已在某航天器多个分系统测试中得以应用。     

Summary of research on soil testing for rock phosphate fertilizers in Western Australia

The relationship between plant yield and values of soils tests for phosphorus (P) was studied in long-term field experiments in south-western Australia for soil previously fertilized with rock phosphate and superphosphate. The rock phosphates studied were: Queensland (Duchess) apatite rock phosphate; reactive apatite rock phosphate from North Carolina; and rock phosphate from Christmas Island (as either C-grade ore or Calciphos). The P fertilizers were applied once only at the start of each experiment, and in subsequent years, soil samples were collected in January-March to measure soil test values. These were compared with plant yields measured later on in that year. The Colwell alkaline bicarbonate soil test was used in all years in all experiments. Olsen, Bray, lactate and Troug tests were used in some years in some experiments. For all soil tests the relationships between yield and soil test values was generally different for rock phosphate and superphosphate. For a given source of P, none of the different soil test reagents was significantly superior for predicting plant yields. The relationship between yield and soil test value was also generally different for different plant species. At one site cultivation was included as a treatment and the relationship varied depending on the cultivation treatment of the topsoil before sowing oats (Avena sativa). The relationship between yield and soil test also differed between years.