PCN VT

Ergonomics, 1973

This paper present optimal preventive maintenance strategy for efficient operation of boilers. Efficient operation of Boiler can be achieved from an optimal preventive maintenance strategy. It would be especially beneficial for those plants that rely on breakdown or run-to-failure maintenance. There are many advantages for having an optimal preventive maintenance strategy. The advantages apply to every kind and size of plant. The law of preventive maintenance strategy is that the higher the value of plant assets and equipment per square foot of plant, the greater will be the return on a preventive maintenance strategy.

Visual Inspection is the single most frequently-used aircraft inspection technique, but is still error-prone. This project follows previous reports on fluorescent penetrant inspection (FPI) and borescope inspection in deriving good practices to increase the reliability of NDI processes through generation of good practices based on analysis of the human role in the inspection system. Inspection in aviation is mainly visual, comprising 80% of all inspection by some estimates, and accounting for over 60% of AD notices in a 2000 study. It is usually more rapid than other NDI techniques, and has considerable flexibility. Although it is usually defined with reference to the eyes and visible spectrum, in fact Visual Inspection includes most other non-machine-enhanced methods, such as feel or even sound. It is perhaps best characterized as using the inspectors’ senses with only simple job aids such as magnifying loupes or mirrors. As such, Visual Inspection forms a vital part of many other NDI techniques where the inspector must visually assess an image of the area inspected, e.g. in FPI or radiography. An important characteristic of Visual Inspection is its flexibility, for example in being able to inspect at different intensities from walk-around to detailed inspection. From a variety of industries, including aviation, we know that when the reliability of visual inspection is measured, it is less than perfect. Visual inspectors, like other NDI inspectors, make errors of both missing a defect and calling a non-defect (misses and false alarms respectively).

Optical Measurement Systems for Industrial Inspection, 1999

For elucidation of complex visual processing such as material perception of realistic objects, multiple research approaches should be combined. Shearing stimulus and response data is an effective strategy to make the results of different studies directly comparable, and to assist a wide range of researchers with different backgrounds to jump into the field. We therefore constructed a database of a variety of material images with standard human discrimination performance attached. We created various material images by using physically-based computer graphics techniques and conducted psychophysical experiments both in the laboratory and through crowdsourcing. The observer's task was material discrimination for six material dimensions (gloss contrast, gloss sharpness, translucent vs. opaque, gold vs. plastic yellow, glass vs. silver, and glossy vs. painted) with several task difficulties controlled by material parameters. We also varied illumination consistency and object geometry. We used a non-verbal procedure (oddity task) for our database to be widely used in diverse studies such as cross-cultural, cross-species, clinical and developmental studies. Results showed that discrimination performance was affected by illumination condition and object geometry, in agreement with previous gloss perception studies, although the pattern of effects was slightly different for some material dimensions. Specifically, we found that discrimination of translucency was easier for rugged shapes than for smooth shapes, while the opposite was the case for gloss perception. We also found that the ability to discriminate the spatial consistency of specular highlights on glossiness perception had a larger individual difference than other tasks. The performance obtained through crowdsourcing was highly correlated with that in the laboratory, which suggests that our database can be used even when the experimental conditions are not strictly controlled under non-laboratory environments. Several projects using our dataset are underway. .

Electronics Reliability and Measurement Technology, 1988

Surface inspection techniques are used for process learning, quality verification, and postmortem analysis in manufacturing for a spectrum of disciplines. We will first summarize trends in surface analysis for integrated circuits, high density interconnection boards, and magnetic disks, emphasizing on-line applications as opposed to off-line or development techniques. We will then look more closely at microcontamination detection from both a patterned defect and a particulate inspection point of view. W i l e the critical problem of tbe week on a given manufacturing line will fluctuate dramatically, taken over time there are at least five types of measurements that are key to yield and productivity today, and which will tend to gate future manufacturing capability. One is pattern inspection of integrated circuits and dense interconnection packages. This is done to verify the pattern back to a software data base, and to u n a v e r process variations and contaminants that manifest themselves as pattern defects. The second is detection of contamination (particulates and asperities) on monitors and product parts. Particles are the single biggest yield killer in the silicon industry, and they will probably retain that distinction for the near future. The third is metrology in two and three dimensions. This would include linewidths, via sizes, trench aspect ratios, and bead dimensions and flying heights. This tests processes like deposition, etching, and lithography overlay, exposure, and development. The fourth is film characteristics such as haze, film thickness, roughness, step coverage, and the presence of contaminating films. The fifth is electrical characteristics, which would include dopant concentration, surface passivation, resistivity (including shorts and opens), and oxide integrity.

1988

In this paper, we will review some visual inspection problems that were presented to our laboratory by a consortium of Belgian industrial companies. These problems were selected to serve as a test vehicle for a software package, called LILY (Leuven Image processing Library), that was developed for the consortium by our laboratory. Therefore, this paper consists of several parts : first, an overview of the LILY software package will be given; then, three case studies carried out with the package will be detailed. The case studies are very different in nature, so that a variety of algorithms will be dealt with. The first case study is about defect inspection in unexposed radiographic film. In this case, image data is presented as a continuous stream of lines of pixels. In the study, convolution techniques, curve fitting methods and Fourier analysis were applied. The second case studv treats the inspection of textured textiles and is thus essentially a texture inspection problem. Here,...

1988

In this paper, we will review some visual inspection problems that were presented to our laboratory by a con- sortium of Belgian industrial companies. These problems were selected to serve as a test vehicle for a software pack- age, called LILY (Leuven Image processing Library), that was developed for the consortium by our laboratory. There- fore, this paper consists of

2017

A means of facilitating the transfer of Optical inspection methods knowledge and skills from academic institutions and their research partners into Panama optics and optical research groups is described. The process involves the creation of an Integrated Knowledge Group Research (IKGR), a partnership led by Polytechnic University of Panama with the support of the SENACYT and Optics and Optometry Department, Polytechnic University of Catalonia. The project is designed to address the shortage of key skills in the field of precision engineering for optical applications. The main issues encountered during the development of the knowledge transfer teaching and learning are discussed, and the outcomes from the first year of knowledge transfer activities are described. In overall summary, the results demonstrate how the Integrated Knowledge Group Research and new approach to knowledge transfer has been effective in addressing the engineering skills gap in precision optics for manufactured ...