scholarly journals Automated Visual Inspection of Ship Hull Surfaces Using the Wavelet Transform

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Carlos Fernández-Isla ◽  
Pedro J. Navarro ◽  
Pedro María Alcover
Keyword(s):  
Wavelet Transform ◽  
Visual Inspection ◽  
Cost Effective ◽  
Automated Visual Inspection ◽  
Decomposition Level ◽  
Ship Hulls ◽  
Reconstruction Scheme ◽  
Effective Operation ◽  
On Line ◽  
Selection Of

A new online visual inspection technique is proposed, based on a wavelet reconstruction scheme over images obtained from the hull. This type of visual inspection to detect defects in hull surfaces is commonly carried out at shipyards by human inspectors before the hull repair task starts. We propose the use of Shannon entropy for automatic selection of the band for image reconstruction which provides a low decomposition level, thus avoiding excessive degradation of the image, allowing more precise defect segmentation. The proposed method here is capable of on-line assisting to a robotic system to perform grit blasting operations over damage areas of ship hulls. This solution allows a reliable and cost-effective operation for hull grit spot blasting. A prototype of the automated blasting system has been developed and tested in the Spanish NAVANTIA shipyards.

On-Line Seam Detection in Rolling Processes Using Snake Projection and Discrete Wavelet Transform

2007 ◽  
Vol 129 (5) ◽  
pp. 926-933 ◽  
Author(s):  
Jing Li ◽  
Jianjun Shi ◽  
Tzyy-Shuh Chang
Keyword(s):  
Wavelet Transform ◽  
Discrete Wavelet Transform ◽  
Projection Method ◽  
Discrete Wavelet ◽  
On Line ◽  
Feature Preserving ◽  
Two Parameters ◽  
T2 Control Chart ◽  
Speed And Accuracy ◽  
Selection Of

This paper describes the development of an on-line quality inspection algorithm for detecting the surface defect “seam” generated in rolling processes. A feature-preserving “snake-projection” method is proposed for dimension reduction by converting the suspicious seam-containing images to one-dimensional sequences. Discrete wavelet transform is then performed on the sequences for feature extraction. Finally, a T2 control chart is established based on the extracted features to distinguish real seams from false positives. The snake-projection method has two parameters that impact the effectiveness of the algorithm. Thus, selection of the parameters is discussed. Implementation of the proposed algorithm shows that it satisfies the speed and accuracy requirements for on-line seam detection.

An Overview of the Trunk Scheduling System for the London Ring Main

1993 ◽  
Vol 28 (11-12) ◽  
pp. 99-109 ◽  
Author(s):  
David Burnell ◽  
Julia Race ◽  
Phil Evans
Keyword(s):  
Decision Support ◽  
Unit Cost ◽  
Cost Effective ◽  
Scheduling System ◽  
Effective Operation ◽  
On Line ◽  
Water Hydraulic ◽  
Water Ring ◽  
Core Part ◽  
Operating Regimes

The London Water Ring Main is one of UK's largest water investments. It will eventually carry half of London's water and greatly increase the flexibility of London's trunk distribution network. The Trunk Scheduling System is a core part of decision-support for the enhanced network. It has been written to help Operational Controllers make best use of that extra flexibility. Cost-effective operation makes best use of the cheapest treatment works, lowenergy-loss routes and off-peak tariffs. These need to be combined to meet projected diurnal demands in over 50 zones and leave each of some 20 service reservoirs at a target end volume, whilst taking no more than the declared “reliable output” from each of 10 works. The schedule proposed must be hydraulically viable as well as cheap. Most route constraints arise from pressure limits (so as not to burst mains or leave customers without water). Hydraulic constraints are non-linear and require on-line hydraulic intelligence as the schedule is developed. The key idea is to regard a schedule as a series of “operating regimes”, each of which is applied for a specified duration. Each regime applies within a particular timeslice. It comprises settings for each pump in the network, together with its implications: a unit cost and the effect of those settings on each source and each reservoir under hydraulic equilibrium. Trunk Scheduling provides a series of modules to answer the questions:which regimes (of the billions possible) should make up the schedule?how long should each selected regime be applied for?in which sequence should the chosen regimes be applied?

Medical Literature Searches -How Many Bibliographic Databases are Needed for Sufficient Retrieval in Medical Topics?

1985 ◽  
Vol 24 (03) ◽  
pp. 163-165 ◽  
Author(s):  
K. John
Keyword(s):  
Medical Literature ◽  
Cost Effective ◽  
Medical Faculty ◽  
Bibliographic Databases ◽  
Literature Searches ◽  
Selection Of

SummaryAs many bibliographic services in medicine are offered, literature searches in eight databases at DIMDI were performed to find out which database is most important in medicine. The distribution of publications from members of the medical faculty of Frankfurt University was examined. No save prediction is possible as to which database will yield most articles. Overlapping from different databases is often rather low. The selection of an appropriate database mix for sufficient recall and in a cost-effective manner.is a task for an experienced searcher.

Teknologi Esktrasi dan Cara Pemisahannya untuk Mendapatkan Kembali Karotenoid dari Minyak Sawit : Suatu Tinjauan

2016 ◽  
Vol 9 (1) ◽  
pp. 80-95
Author(s):  
Agus Sudibyo ◽  
Sardjono Sardjono
Keyword(s):  
Vitamin A ◽  
Palm Oil ◽  
Beta Carotene ◽  
Cost Effective ◽  
Raw Material ◽  
Extraction And Separation ◽  
Molecular Product ◽  
Industrial Use ◽  
Palm Oil Mill ◽  
Selection Of

Crude palm oil (CPO)is the richest natural plant source of carotenoids in terms of retinol (pro-vitamin A) equivalent, whereas palm oil mill effluent (POME) is generated from palm oil industry that contains oil and carotenes that used to be treated before discharge. Carotenoids are importance in animals and humans for the purpose of the enhancement of immune response, conversion of vitamin A and scavenging of oxygen radicals. This component has different nutritional  functions and benefits to humaan health. The growing interest in the other natural sources of beta-carotene and growing awareness to prevent pollution has stimulated the industrial use of CPO and POME as a raw material for carotenoids extraction. Various technologies of extraction and separation have been developed in order to recover of carotenoids.This article reports on various technologies that have been developed in order to recover of carotenoids from being destroyed in commercial refining of palm oil and effects of some various treatments on the extraction end separation for carotenoid from palm oil and carotenoids concentration. Principally, there are different technologies, and there is one some future which is the use of solvent. Solvent plays important role  in the most technologiest, however the problem of solvents which are used is that they posses potentiaal fire health and environmental hazards. Hence selection of the  most safe, environmentally friendly and cost effective solvent is important to design of alternative extraction methods.Chemical molecular product design is one of the methods that are becoming more popular nowadays for finding solvent with the desired properties prior to experimental testing.ABSTRAKMinyak sawit kasar merupakan sumber karotenoid terkaya yang berasal dari tanaman sawit sebagai senyawa yang sama dengan retinol atau pro-vitamin A; sedangkan limbah pengolahan minyak sawit dihasilkan dari industri pengolahan minyak sawit yang berisi minyak dan karotene yang perlu diberi perlakuan terlebih dahulu sebelum dibuang. Karotenoid merupakan bahan penting yang diperlukan pada hewan dan manusia guna memperkuat tanggapan terhadap kekebalan, konversi ke vitamin A dan penangkapan gugus oksigen radikal. Dengan berkembangnya ketertarikan dalam mencari beta-karotene yang bersumber dari alam lain dan meningkatnya kesadaran untuk mencegah adanya pencemaran lingkungan, maka mendorong suatu industri untuk menggunakan CPO dan POME sebagai bahan baku untuk diekstrak karotenoidnya. Berbagai macam teknologi guna mengekstrak dan memisahkan karotenoid telah dikembangkan untuk mendapatkan kembali karotenoidnya. Makalah ini melaporkan dan membahas berbagai jenis teknologi yang telah dikembangkan guna mendapatkan kembali senyawa karotenoid dari kerusakan di dalam proses pemurnian minyak sawit secara komersial dan pengaruh beberapa perlakuan terhadap ekstrasi dan pemisahan karotenoid dari minyak sawit dan konsentrasi karotenoidnya. Pada prinsipnya, berbagai teknologi yang digunakan untuk mengekstrak dan memisahkan karotenoid terdapat perbedaan, dan terdapat salah satu teknologi yang digunakan untuk esktrasi dan pemisahan karotenoid adalah menggunakan bahan pelarut. Pelarut yang digunakan mempunyai peranan yang penting dalam teknologi ekstrasi; namun pelarut yang digunakan untuk mengekstrak tersebut mempunyai persoalan karena berpotensi mengganggu kesehatan dan membahayakan cemaran lingkungan. Oleh karena itu, pemilihan jenis teknologi yang aman, ramah terhadap lingkungan dan biaya yang efektif untuk penggunaan pelarut merupakan hal penting sebelum dilakukan desain metode/teknologi alternatif untuk esktrasi karotenoid. Pola produk molekuler kimia merupakan salah satu metode yang saat ini menjadi lebih populer untuk mencari pelarut dengan sifat-sifat yang dikehendaki sebelum diujicobakan. Kata kunci :    karotenoid, ekstrasi, pemisahan, teknologi, minyak sawit kasar, limbah industri pengolahan sawit.

Selection of one-dimensional sedimentation: models for on-line use

1995 ◽  
Vol 31 (2) ◽  
pp. 193-204 ◽  
Author(s):  
Koen Grijspeerdt ◽  
Peter Vanrolleghem ◽  
Willy Verstraete
Keyword(s):  
Steady State ◽  
Selection Criteria ◽  
Data Sets ◽  
Concentration Profiles ◽  
A Posteriori ◽  
One Dimensional ◽  
On Line ◽  
Dynamic Concentration ◽  
Selection Of ◽  
Modelling Task

A comparative study of several recently proposed one-dimensional sedimentation models has been made. This has been achieved by fitting these models to steady-state and dynamic concentration profiles obtained in a down-scaled secondary decanter. The models were evaluated with several a posteriori model selection criteria. Since the purpose of the modelling task is to do on-line simulations, the calculation time was used as one of the selection criteria. Finally, the practical identifiability of the models for the available data sets was also investigated. It could be concluded that the model of Takács et al. (1991) gave the most reliable results.

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