Mural inspection by vibration measurements with TV-holography

A commonly encountered problem in the conservation of historical murals is the identification of sections in the plaster that have detached from the wall and thus threaten to fall off. Commonly, walls are inspected by the acoustic response to a gentle finger-tapping (percussion method). Since this is a costly and cumbersome technique, means for a more automatic inspection are searched for. A TV-holography system of increased sensitivity in combination with acoustic excitation of the object is shown to be a new and powerful tool for monitoring of loose areas. It has the advantage of non-contact and remote operation which, for example, is extremely useful in large buildings. Principles of the method, experimental results obtained at an artificial wall in the laboratory, and a thorough comparison of results from historical sites gained by the traditional percussion method and the new technique are presented. The latter shows very good agreement in the assessment of wall quality and thus is evidence of the suitability of the optical equipment for tasks in conservation.     

计量调整型抽样检验系统GB/T6378-1986与ISO3951 :1989的比较分析

GB/T6378-1986作为计量抽样检验方面的基础性国家标准,是参照国际标准ISO3951:1989而制定的。1989年国际标准化组织ISO/TC69发布了ISO3951的修订版本ISO3951:1989,ISO3951的这一修订版反映了计量抽样检验的最新研究成果,为开展国家标准GB/T6378的修订工作,本文系统地对GB/T6378-86和ISO3951:89进行了比较分析研究。     

自动实时激光全息无损检测系统

介绍一种自动激光全息无损检测系统。该系统由计算机控制自动曝光，并对全息干版进行自动冲洗和对测量数据进行处理，解决了一次曝光激光全息实时检测中全息干版无法精确复位的问题。计算机控制真空加载，缺陷大小及位置由计算机打印输出，一次最大测量面积为０５ｍ×１２ｍ，最小分辨缺陷尺寸为３ｍｍ。     

Technically optimal inspection policy with arithmetical adaption

A process is considered whose quality deteriorates accordingto a constant failure intensity . As in practice it can be difficultto estimate the true value of the purpose of this paper isto present a strategy which can be applied without knowing .In order to maximize the number of conforming items per timeunit perfect inspections and renewals are performed. The lengthof the inspection interval is described by an arithmetical sequenceand changes by the time depending on perceived assignable causes.Optimal adaptive control plans provide nearly the same performanceas in the case when is known.     

A maintenance model with failures and inspection following Markovian arrival processes and two repair modes

We consider a deteriorating system submitted to external and internal failures, whose deterioration level is known by means of inspections. There are two types of repairs: minimal and perfect, depending on the deterioration level, each one following a different phase-type distribution. The failures and the inspections follow different Markovian arrival processes (MAP). Under these assumptions, the system is governed by a generalized Markov process, whose state space and generator are constructed. This general model includes the phase-type renewal process as a special case. The distribution of the number of minimal and perfect repairs between two inspections are determined. A numerical application optimizing costs is performed, and different particular cases of the model are compared.     

磁粉法检测表面裂纹概率曲线的测定

本文介绍了利用实物零件测定裂纹检出概率的方法，并作出了用磁粉法检测表面裂纹的检测概率曲线，为大型构件检测周期的确定提供了可靠数据，为结构损伤容限设计，可靠性设计提供了重要的依据。     

Effects of angle of probe laser and pinhole diameter on the time-resolved optical inspection system

A real-time in-situ time-resolved optical inspection system comprising two He-Ne probe lasers, a digital oscilloscope, and three fast photodetectors is developed. The effects of angle of probe laser and pinhole diameter on the time-resolved optical inspection system are investigated during excimer laser crystallization. The longest melt duration and ablation excimer laser fluence are independent of pinhole size. The pinhole with a diameter of 0.3 mm is recommended to use in the time-resolved optical inspection system. Determination of melt duration and observation of explosive crystallization oscillation are independent of angle of probe laser, but four criteria for the relationship between probe lasers and photodetectors should be followed.     

A new method to characterizing surface roughness of TiO2 thin films

Titanium dioxide (TiO₂) thin films have been widely coated in the self-cleaning glass for facade application. The benefit of these glasses is its ability to actively decompose organic compounds with the help of ultraviolet light. Understanding the surface roughness of TiO₂ thin films is important before manufacturing of self-cleaning glasses using TiO₂ thin films because surface roughness of TiO₂ thin films has highly significant influence on the photocatalytic performance. Traditional approach for measuring surface roughness of TiO₂ thin films is atomic force microscopy. The disadvantage of this approach include long lead-time and slow measurement speed. To solve this problem, an optical inspection system for rapidly measuring the surface roughness of TiO₂ thin films is developed in this study. It is found that the incident angle of 60° is a good candidate for measuring surface roughness of TiO₂ thin films and y=90.391x+0.5123 is a trend equation for predicting the surface roughness of TiO₂ thin films. Roughness average (Ra) of TiO₂ thin films (y) can be directly determined from the peak power density (x) using the optical inspection system developed. The results were verified by white-light interferometer. The measurement error rate of the optical inspection system developed can be controlled by about 8.8%. The saving in inspection time of the surface roughness of TiO₂ thin films is up to 83%.     

Surface structure monitoring with plastic optical fiber

A sensor was designed using a plastic optical fiber to study the potential of detecting structural deformities and corrosion of metallic surfaces, in particular for applications in constricted areas such as pipes. The principle of the sensor is based on the collection of scattered light reflected by the surface imperfections. Several types of metallic materials in various surface profiles and stages of corrosion have been studied. The sensor was able to determine the position of ridges on the surface and corroded regions in all cases evaluated in the study. A sensitivity of 100 mV/mm was detectable for proximity and a vertical resolution of 1 mm has been measured.     

X-Y振镜扫描式舌诊高光谱采集系统

针对目前舌诊研究中在舌体信息全面获取方面存在严重不足,将高光谱技术用到舌诊的研究中来,提出了一种基于X-Y振镜扫描式舌诊高光谱采集系统.通过模拟实验,采集与舌体大小相似图片的高光谱信息,验证了该系统可以用于舌体高光谱信息采集,实验结果表明,与现有舌诊客观化研究相比,该系统可以获得更多的舌体信息,为舌诊客观化研究提供了一...