电压频率转换器在诊断X射线检测中的应用

根据诊断X射线检测的设计要求,结合STM32单片机的特点,将电压频率转换器应用到诊断X射线检测系统中。分析了电压频率转换器的工作原理,给出了电压频率转换器电路设计及诊断X射线检测系统的硬件构成,并对检测系统的控制程序流程进行详细的说明。电压频率转换器具有设计简单、低成本、高精度、应用灵活等特点,适合于低速数据采集。     

轴承试验中心分布式监控管理系统

本文设计了轴承试验中心分布式监控管理系统，系统可对多台试验机进行在线监测，对被试验轴承做实时诊断，有故障时立即报警，并可将整个试验过程数据通过网络传送到上位机进行显示并存储到数据库中，供技术人员分析使用。该系统已在轴承生产企业得到了成功的应用。     

Estimators of sensitivity and specificity in the presence of verification bias: A Bayesian approach

Verification bias can occur if some of the patients with test results are not selected to receive the gold standard procedure. Unverified cases frequently are not suggestive to be positives. Consequently, the set of verified cases overestimates the number of true positives and underestimates the number of true negatives. The sensitivity and specificity estimates based only on the patients with verified disease are often biased. In this article we derive estimators for sensitivity and specificity not subject to verification bias using a Bayesian approach. Marginal posterior densities of all parameters are estimated using the Gibbs sampler algorithm. An application to the study of accuracy of Hybrid Capture II in the diagnosis of cervical intraepithelial neoplasia grades 2 and 3 illustrates the proposed methodology.     

Compact optical diagnostic device for isothermal nucleic acids amplification

We recently reported the successful use of the loop-mediated isothermal amplification (LAMP) reaction for hepatitis B virus (HBV) DNA amplification and its optimal primer design method. In this study, we report the development of an integrated isothermal device for both amplification and detection of targeted HBV DNA. It has two major components, a disposable polymethyl methacrylate (PMMA) micro-reactor and a temperature-regulated optical detection unit (base apparatus) for real-time monitoring of the turbidity changes due to the precipitation of DNA amplification by-product, magnesium pyrophosphate. We have established a correlation curve (R² = 0.99) between the concentration of pyrophosphate ions and the level of turbidity by using a simulated chemical reaction to evaluate the characteristics of our device. For the applications of rapid pathogens detection, we also have established a standard curve (R² = 0.96) by using LAMP reaction with a standard template in our device. Moreover, we also have successfully used the device on seven clinical serum specimens where HBV DNA levels have been confirmed by real-time PCR. The result indicates that different amounts of HBV DNA can be successfully detected by using this device within 1 h.     

Diagnostic test decision for suppliers in cruise-building supply chain with information asymmetry

To solve the potential supply disruption in cruise-building supply chain, this study explores a supply system consisting of a monopoly supplier, a new entrant supplier, and a cruise-building manufacturer. A two-step option contract including diagnostic test and process improvement is designed to solve the order quantity allocation and to avoid supply disruption. The analysis combines the decision tree with the principal-agent model under information asymmetry. The result shows that the cruise-building manufacturer would like to allocate more orders to the unreliable supplier who implements process improvement. In the end, the detailed numerical analysis is implemented to justify the proposal.     

Local influence in estimating equations

Local influence diagnostics based on estimating equations as the role of a gradient vector derived from any fit function are developed for repeated measures regression analysis. Our proposal generalizes tools used in other studies ( [Cook, 1986] and [Cadigan and Farrell, 2002]), considering herein local influence diagnostics for a statistical model where estimation involves an estimating equation in which all observations are not necessarily independent of each other. Moreover, the measures of local influence are illustrated with some simulated data sets to assess influential observations. Applications using real data are presented.     

Feature-based assessment of visuo-spatial neglect patients using hand-drawing tasks

Visuo-spatial neglect (VSN) is a post-stroke condition in which a patient fails to respond to stimuli on one side of the visual field. Using an established pencil-and-paper-based method for the assessment of VSN (the Rivermead Behavioural Inattention Test) as a reference, a battery of computer-based hand-drawing tests is developed and shown to be effective in distinguishing between stroke subjects with and without neglect. The novel approach adopts measurements both of the outcome and the process by which the drawing tasks are executed. This approach provides a novel diagnostic capability which results in increased test sensitivity, a more objective assessment and a reduction in overall evaluation time. The paper describes the development of a binary assessment system using the computer-based acquisition and analysis of task data alongside feature selection techniques to maximise performance.

The Beck Depression Inventory and Research Diagnostic Criteria: Congruence in an Older Population.

This study examined the congruence between conventional cutoff scores on the Beck Depression Inventory (BDI) and selected diagnostic classifications of the Research Diagnostic Criteria in a sample of 102 elders seeking psychological treatment. Only 16.67% were misclassified by customary BDI cutoff scores. Minor Depressive Disorders were less clearly identified than Major Depressive Disorders or nondepressed status. Similar results were obtained in a second sample of elders not seeking treatment. Findings support the utility of the BDI as a screening instrument for identification of clinically depressed elders. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

数字电路自动测试生成实用化软件

介绍了针对ATE应用和TPS开发的需要首次在Windows NT平台上研制的一套数字电路诊断测试数据自动生成的实用化软件系统OCTOPUS100。该软件与已有的ATPG软件相比具有成本低,有利于推广等优点。该软件具有灵活性、实用性和通用性,经实验与试用表明有很高的实用价值。