WorldWideScience

Sample records for based inspection techniques

  1. CANDU in-reactor quantitative visual-based inspection techniques

    Science.gov (United States)

    Rochefort, P. A.

    2009-02-01

    This paper describes two separate visual-based inspection procedures used at CANDU nuclear power generating stations. The techniques are quantitative in nature and are delivered and operated in highly radioactive environments with access that is restrictive, and in one case is submerged. Visual-based inspections at stations are typically qualitative in nature. For example a video system will be used to search for a missing component, inspect for a broken fixture, or locate areas of excessive corrosion in a pipe. In contrast, the methods described here are used to measure characteristic component dimensions that in one case ensure ongoing safe operation of the reactor and in the other support reactor refurbishment. CANDU reactors are Pressurized Heavy Water Reactors (PHWR). The reactor vessel is a horizontal cylindrical low-pressure calandria tank approximately 6 m in diameter and length, containing heavy water as a neutron moderator. Inside the calandria, 380 horizontal fuel channels (FC) are supported at each end by integral end-shields. Each FC holds 12 fuel bundles. The heavy water primary heat transport water flows through the FC pressure tube, removing the heat from the fuel bundles and delivering it to the steam generator. The general design of the reactor governs both the type of measurements that are required and the methods to perform the measurements. The first inspection procedure is a method to remotely measure the gap between FC and other in-core horizontal components. The technique involves delivering vertically a module with a high-radiation-resistant camera and lighting into the core of a shutdown but fuelled reactor. The measurement is done using a line-of-sight technique between the components. Compensation for image perspective and viewing elevation to the measurement is required. The second inspection procedure measures flaws within the reactor's end shield FC calandria tube rolled joint area. The FC calandria tube (the outer shell of the FC) is

  2. a Holistic Approach for Inspection of Civil Infrastructures Based on Computer Vision Techniques

    Science.gov (United States)

    Stentoumis, C.; Protopapadakis, E.; Doulamis, A.; Doulamis, N.

    2016-06-01

    In this work, it is examined the 2D recognition and 3D modelling of concrete tunnel cracks, through visual cues. At the time being, the structural integrity inspection of large-scale infrastructures is mainly performed through visual observations by human inspectors, who identify structural defects, rate them and, then, categorize their severity. The described approach targets at minimum human intervention, for autonomous inspection of civil infrastructures. The shortfalls of existing approaches in crack assessment are being addressed by proposing a novel detection scheme. Although efforts have been made in the field, synergies among proposed techniques are still missing. The holistic approach of this paper exploits the state of the art techniques of pattern recognition and stereo-matching, in order to build accurate 3D crack models. The innovation lies in the hybrid approach for the CNN detector initialization, and the use of the modified census transformation for stereo matching along with a binary fusion of two state-of-the-art optimization schemes. The described approach manages to deal with images of harsh radiometry, along with severe radiometric differences in the stereo pair. The effectiveness of this workflow is evaluated on a real dataset gathered in highway and railway tunnels. What is promising is that the computer vision workflow described in this work can be transferred, with adaptations of course, to other infrastructure such as pipelines, bridges and large industrial facilities that are in the need of continuous state assessment during their operational life cycle.

  3. An Eddy Current Testing Platform System for Pipe Defect Inspection Based on an Optimized Eddy Current Technique Probe Design

    Directory of Open Access Journals (Sweden)

    Damhuji Rifai

    2017-03-01

    Full Text Available The use of the eddy current technique (ECT for the non-destructive testing of conducting materials has become increasingly important in the past few years. The use of the non-destructive ECT plays a key role in the ensuring the safety and integrity of the large industrial structures such as oil and gas pipelines. This paper introduce a novel ECT probe design integrated with the distributed ECT inspection system (DSECT use for crack inspection on inner ferromagnetic pipes. The system consists of an array of giant magneto-resistive (GMR sensors, a pneumatic system, a rotating magnetic field excitation source and a host PC acting as the data analysis center. Probe design parameters, namely probe diameter, an excitation coil and the number of GMR sensors in the array sensor is optimized using numerical optimization based on the desirability approach. The main benefits of DSECT can be seen in terms of its modularity and flexibility for the use of different types of magnetic transducers/sensors, and signals of a different nature with either digital or analog outputs, making it suited for the ECT probe design using an array of GMR magnetic sensors. A real-time application of the DSECT distributed system for ECT inspection can be exploited for the inspection of 70 mm carbon steel pipe. In order to predict the axial and circumference defect detection, a mathematical model is developed based on the technique known as response surface methodology (RSM. The inspection results of a carbon steel pipe sample with artificial defects indicate that the system design is highly efficient.

  4. Novel fiber-based technique for inspection of holes in narrow-bore tubes

    Science.gov (United States)

    Bernard, Fabien; Flaherty, Tony; O'Connor, Gerard M.

    2009-06-01

    Optical tools offer a route to increasing throughput and efficiency in industrial inspection operations, one of the most time-consuming and labour-intensive aspects of modern manufacturing. One prominent example in the medical device industry is inspection of drilled holes, particularly in narrow-bore tubes (precision-flow devices, such as catheters for drug delivery, radio-opaque contrast agents, etc). The products in which these holes feature are increasing in complexity (reduced dimensions, increasing number of drilled features- in some products now reaching into the hundreds). These trends present a number of technical challenges, not least to ensure that holes are completed and that no damage to the part occurs as a result of over-drilling, for example. This paper will present a novel sensor based on back-side illumination of the drilled hole using side-glowing optical fibers to detect, qualify and quantify drilled holes. The concept is based on inserting a laser-coupled side-glowing optical fiber into the lumen of the tube to be drilled, and imaging the light emitted from this fiber through a drilled hole using a vision system mounted external to the tube. The light from the fiber allows rapid determination of hole completion, shape and size, as well as quantity in the case of products with multiple holes. If the fiber is mounted in the tube prior to drilling, the light emitted from the fiber can be used as a real-time hole breakthrough sensor, preventing under or overdrilling of the tube.

  5. Photoelectric Inspecting Techniques for Parallelism and Swaying of Rocket

    Institute of Scientific and Technical Information of China (English)

    ZHOU He; MA Hong; YAN Yu-feng; BAI Su-ping

    2008-01-01

    Introduced is a traditional method for measuring the swaying and multi-barrel parallelism, and deficiencies are analyzed too. Based on that, expatiated is a new method of using a set of equipments to measure the two parameters synthetically, adopting integrative photoelectric inspecting technique, laser technique and computer picture processing technique.

  6. Inspection and Monitoring Techniques for Power Lines

    Institute of Scientific and Technical Information of China (English)

    DAI Kaoshan; CHEN Shenen

    2011-01-01

    Structural assessment is prerequisite for proper maintenance of civil infrastructure.In the begining of this paper, modern inspection and monitoring methods are briefly reviewed.Experiences in applying imagebased methods for highway bridge inspection are described shortly afterward.Studies are then extended to explore technologies for power delivery infrastructure evaluation.Typical power line components are first introduced.Structural analyses show complicated coupling phenomena in the power line system; and its vulnerability is intensified by extreme environment or human induced events.As a main interest, the state-of-art of power line inspection is summarized.Both visual observations and inspections assisted with novel techniques are presented.Real time monitoring of the power line is also investigated in this paper.Technologies that have potentials for monitoring power cables, insulators, and support structures are identified.A conceptual integrated design is proposed by the authors through combining innovative inspection with promising monitoring methods to ensure a sustainable, smart power line.

  7. Codified Risk Based Inspection Planning

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Faber, M.H.

    2002-01-01

    and member failure and at the same time minimizing overall total service life costs. Generic inspections plans can then be established for representative fatigue sensitive details in terms of characteristics such as FDF (Fatigue Design Factor), detail type, RSR (Reserve Strength Ratio) given fatigue failure......Simplified methods are described for reliability- and risk-based inspection planning of steel structures. The methods simplify the practical aspects of identifying inspection plans complying both with specific requirements to the maximum acceptable annual probability of structural collapse...

  8. A Comparative Study of Inspection Techniques for Array Packages

    Science.gov (United States)

    Mohammed, Jelila; Green, Christopher

    2008-01-01

    This viewgraph presentation reviews the inspection techniques for Column Grid Array (CGA) packages. The CGA is a method of chip scale packaging using high temperature solder columns to attach part to board. It is becoming more popular over other techniques (i.e. quad flat pack (QFP) or ball grid array (BGA)). However there are environmental stresses and workmanship challenges that require good inspection techniques for these packages.

  9. POD generator project, development of numerical modeling tools for quantitative assessment of the performance of non-destructive inspection techniques

    NARCIS (Netherlands)

    Bloom, J.G.P.; Stelwagen, U.; Mast, A.; Volker, A.W.F.; Krom, A.H.M.; Mohamoud, A.A.; Gils, G.P. van

    2009-01-01

    Risk based inspection strategies rely on detailed knowledge of the performance of inspection techniques. It is well known that every inspection technique has limitations in terms of reliability and effectiveness. Moreover, these are influenced by many factors. E.g. it depends on operator skills, ins

  10. The Application of Phased Array Ultrasonic Techniques for Inspection of Railway Axles from Their End Face

    Science.gov (United States)

    Liaptsis, D.; Cooper, I.; Boyle, K.; Nicholson, P. I.

    2011-06-01

    As part of the development of a non destructive testing (NDT) system combining complementary inspection techniques, an inspection system based on phased array ultrasonic testing (PAUT) for detection of transverse cracking in solid railway axles is being developed. This paper presents the initial study, which includes the PAUT experimental setup and the initial results obtained after testing the system on railway axle blocks. The inspection of solid axles from their axle end face is investigated.

  11. Proposal for inclusion of the risk based inspection technique in Regulatory Standard NR 13; Proposta de inclusao da tecnica de inspecao baseada em risco na Norma Regulamentadora NR 13

    Energy Technology Data Exchange (ETDEWEB)

    Esteves, Vinicius Teixeira; Lima, Marco Aurelio Oliveira [Det Norske Veritas Ltda. (DNV), Rio de Janeiro, RJ (Brazil)

    2012-07-01

    In Brazil, the Regulatory Standard n. 13 (NR 13) establishes requirements for the inspection of boilers and pressure vessels which has main objective of preventing accidents with these types of equipment. Additionally, it has the Risk-Based Inspection (RBI) technique as an effective way to manage the mechanical integrity of various types of static mechanical equipment by through an inspection planning based on the risk factor. In this study, it is being proposed to include the RBI technique, in the NR 13, for the planning and definition of periods for the safety inspection of boilers and pressure vessels in order to promote an increase in the operational safety in process industries in Brazil. In this study it was carried out a critical analysis of NR 13 and RBI, and beyond that a bibliographic research of various international documents that relate the operational safety of pressurized equipment with the inspection activity, and the acceptability of RBI by governments, agencies and organizations around the world. It is considered that the inclusion and formal acceptance of RBI technique in the NR 13 must be accompanied by a rigorous control to avoid the 'trivialization' of its use and ensure the implementation rational, efficient and reliable. Finally, it was developed and suggested basic elements and minimum requirements to be inserted in the NR 13, to be attended, in order mandatory, by the companies that choose the implementation and use of the RBI technique as a tool for the planning of safety inspection of boilers and pressure vessels. It is concluded that the formal acceptance of the RBI technique in the NR 13 could aggregate much value to this standard, with regard to the prevention of accidents involving boilers or pressure vessels, and provide a technological jump to the companies that make use of RBI technique in Brazil. (author)

  12. Projectile Ullage Inspection Technique: Laboratory Demonstration Apparatus.

    Science.gov (United States)

    1983-08-01

    inspection of projectiles was feasible. The mercury manometer was used because it was the only gauge readily available in the laboratory that was...pres- sure. It is suggested that the mercury manometer be replaced by a panel-mounted diaphragm or Bourdon tube gauge. The full-scale pressure range of...When the mercury manometer is used, the volume of the pressure indicator changes linearly with pres- sure (it is assumed that the manometer tube

  13. Risk-based methodology for USNRC inspections

    Energy Technology Data Exchange (ETDEWEB)

    Wong, S.M. [Brookhaven National Lab., Upton, NY (United States); Holahan, G.M.; Chung, J.W.; Johnson, M.R. [Nuclear Regulatory Commission, Washington, DC (United States). Office of Nuclear Reactor Regulation

    1995-12-01

    This paper describes the development and trial applications of a risk-based methodology to enhance the inspection processes for US nuclear power plants. Objectives of risk-based methods to complement prescriptive engineering approaches in US Nuclear Regulatory Commission (USNRC) inspection programs are presented. Insights from time-dependent risk profiles of plant configurational from Individual Plant Evaluation (IPE) studies were integrated to develop a framework for optimizing inspection efforts in NRC regulatory initiatives. Lessons learned from NRC pilot applications of the risk-based methodology for evaluation of the effectiveness of operational risk management programs at US nuclear power plant sites are also discussed.

  14. Vision-based precision inspection system for profile and performance of small and micro gears using the intelligent image processing techniques and virtual master gears

    Science.gov (United States)

    Pahk, Heui Jae; Hwang, Young Min; Lee, Il Hwan; Ahn, Woo Jung

    2000-10-01

    As the product size become smaller, much smaller sized parts are increasingly required in many products fabrication such as cameras, camcorders, and electric appliances, etc. Small or micro gears whose sizes are about few hundred micrometers to few millimeters have been greatly required for the above products, as they become most efficient parts for power transmission. The small of micro gears are prone to geometrical and functioning inaccuracy during the micro fabrication processes, and thus the measurement system has been desired for the geometry and performance checking of gears. In this paper, a precision inspection system is developed for the gear checking, consisting of the optical vision microscope, vision image processing modules with subpixel accuracy, and the profile inspection software using the virtual master jigs/gears mathematically generated. For accurate analysis of the gear geometry from the captured gear image through the optical vision system, a highly accurate vision image processing algorithm has been implemented, where two dimensional subpixelling technique is developed having about one tenth subpixel accuracy. A mathematically generated mater gears/jigs are implemented: several core parameters of the gear profile are calculated from the comparison between the virtual master and the measured gears. Virtual precision ball jigs are simulated between gear teeth profile, and thus the runout parameter can be successfully evaluated from the virtual jig movement on the gear teeth image. The eccentricity parameters can also be calculated from the sinusoidal fitting of the virtual ball movement. The development precision inspection system for small or micro gears has been applied to practical gears of various range, and the essential gear parameters are successfully measured with sub micrometer accuracy.

  15. Luminescence imaging strategies for drone-based PV array inspection

    DEFF Research Database (Denmark)

    Benatto, Gisele Alves dos Reis; Riedel, Nicholas; Thorsteinsson, Sune

    2017-01-01

    he goal of this work is to perform outdoor defect detection imaging that will be used in a fast, accurate and automatic drone-based survey system for PV power plants. The imaging development focuses on techniques that do not require electrical contact, permitting automatic drone inspections...

  16. A Study on TOFD Inspection Using Phased Array Ultrasonic Technique

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Byung Sik; Kim, Yong Sik; Lee, Hee Jong [Korea Electric Power Research Institute, Daejeon (Korea, Republic of); Lee, Young Ho [Chungnam National University, Daejeon (Korea, Republic of)

    2005-08-15

    The techniques in order to measure the depth of defect in weldment and structure accurately have been developed. Many researches have made efforts to develop the methods for the accurate depth sizing of defect. TOFD is known as the most accurate method of various methods for measuring depth sizing. However, there is a possibility to miss defects because of the limitation of beam coverage for the ultrasound incident angle. In this study, the results for detectability and depth sizing using phased array ultrasonic technique for thick body were compared with those of conventional TOFD technique. It was experimentally confirmed that the phased array ultrasonic TOFD technique gives good detectability and accurate depth measurement for the various types of defects. The phased array ultrasonic TOFD technique developed in this study will contribute to increase the inspection reliability in thick component such as the pressure vessel of power generation industry

  17. Inspection of an artificial heart by the neutron radiography technique

    CERN Document Server

    Pugliesi, R; Andrade, M L G; Menezes, M O; Pereira, M A S; Maizato, M J S

    1999-01-01

    The neutron radiography technique was employed to inspect an artificial heart prototype which is being developed to provide blood circulation for patients expecting heart transplant surgery. The radiographs have been obtained by the direct method with a gadolinium converter screen along with the double coated Kodak-AA emulsion film. The artificial heart consists of a flexible plastic membrane located inside a welded metallic cavity, which is employed for blood pumping purposes. The main objective of the present inspection was to identify possible damages in this plastic membrane, produced during the welding process of the metallic cavity. The obtained radiographs were digitized as well as analysed in a PC and the improved images clearly identify several damages in the plastic membrane, suggesting changes in the welding process.

  18. Vibrational Based Inspection Of A Steel Mast

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Rytter, A.

    1994-01-01

    The aim of this paper is to present the results from a research project concerning vibrational based inspection of a 20 meter high steel mast containing well defined damages. Introductory analyses dealing with among other things evaluation of potential damage indicators and determination...

  19. Inspection of pipeline girth welds with ultrasonic phased array technique

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A novel automatic ultrasonic system used for the inspection of pipeline girth welds is developed, in which a linear phased array transducer using electronic scan is adopted. Optimal array parameters are determined based on a mathematical model of acoustic field for linear phased array derived from Huygens' principle. The testing method and the system structure are introduced. The experimental results show that the phased array transducer system has the same detectability as that of conventional ultrasonic transducer system, but the system architecture can be simplified greatly, and the testing flexibility and the testing speed can be improved greatly.

  20. Inspection-Repair based Availability Optimization of Distribution Systems using Teaching Learning based Optimization

    Science.gov (United States)

    Tiwary, Aditya; Arya, L. D.; Arya, Rajesh; Choube, S. C.

    2016-09-01

    This paper describes a technique for optimizing inspection and repair based availability of distribution systems. Optimum duration between two inspections has been obtained for each feeder section with respect to cost function and subject to satisfaction of availability at each load point. Teaching learning based optimization has been used for availability optimization. The developed algorithm has been implemented on radial and meshed distribution systems. The result obtained has been compared with those obtained with differential evolution.

  1. Principles and status of neutron-based inspection technologies

    Science.gov (United States)

    Gozani, Tsahi

    2011-06-01

    Nuclear based explosive inspection techniques can detect a wide range of substances of importance for a wide range of objectives. For national and international security it is mainly the detection of nuclear materials, explosives and narcotic threats. For Customs Services it is also cargo characterization for shipment control and customs duties. For the military and other law enforcement agencies it could be the detection and/or validation of the presence of explosive mines, improvised explosive devices (IED) and unexploded ordnances (UXO). The inspection is generally based on the nuclear interactions of the neutrons (or high energy photons) with the various nuclides present and the detection of resultant characteristic emissions. These can be discrete gamma lines resulting from the thermal neutron capture process (n,γ) or inelastic neutron scattering (n,n'γ) occurring with fast neutrons. The two types of reactions are generally complementary. The capture process provides energetic and highly penetrating gamma rays in most inorganic substances and in hydrogen, while fast neutron inelastic scattering provides relatively strong gamma-ray signatures in light elements such as carbon and oxygen. In some specific important cases unique signatures are provided by the neutron capture process in light elements such as nitrogen, where unusually high-energy gamma ray is produced. This forms the basis for key explosive detection techniques. In some cases the elastically scattered source (of mono-energetic) neutrons may provide information on the atomic weight of the scattering elements. The detection of nuclear materials, both fissionable (e.g., 238U) and fissile (e.g., 235U), are generally based on the fissions induced by the probing neutrons (or photons) and detecting one or more of the unique signatures of the fission process. These include prompt and delayed neutrons and gamma rays. These signatures are not discrete in energy (typically they are continua) but temporally

  2. Verification of Remote Inspection Techniques for Reactor Internal Structures of Liquid Metal Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Young Sang; Lee, Jae Han

    2007-02-15

    The reactor internal structures and components of a liquid metal reactor (LMR) are submerged in hot sodium of reactor vessel. The division 3 of ASME code section XI specifies the visual inspection as major in-service inspection (ISI) methods of reactor internal structures and components. Reactor internals of LMR can not be visually examined due to opaque liquid sodium. The under-sodium viewing techniques using an ultrasonic wave should be applied for the visual inspection of reactor internals. Recently, an ultrasonic waveguide sensor with a strip plate has been developed for an application to the under-sodium inspection. In this study, visualization technique, ranging technique and monitoring technique have been suggested for the remote inspection of reactor internals by using the waveguide sensor. The feasibility of these remote inspection techniques using ultrasonic waveguide sensor has been evaluated by an experimental verification.

  3. Coke drums inspection and evaluation using stress and strain analysis techniques

    Energy Technology Data Exchange (ETDEWEB)

    Haraguchi, Marcio Issamu [Tricom Tecnologia e Servicos de Manutencao Industrial Ltda., Piquete, SP (Brazil); Samman, Mahmod [Houston Engineering Solutions, Houston, TX (United States); Tinoco, Ediberto Bastos; Marangone, Fabio de Castro; Silva, Hezio Rosa da; Barcelos, Gustavo de Carvalho [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)

    2012-07-01

    Coke drums deform due to a complex combination of mechanical and thermal cyclic stresses. Bulges have progressive behavior and represent the main maintenance problem related to these drums. Bulge failure typically result in through-wall cracks, leaks, and sometimes fires. Such failures generally do not represent a great risk to personnel. Repairs needed to maintain reliability of these vessels might require extensive interruption to operation which in turn considerably impacts the profitability of the unit. Therefore the condition, progression and severity of these bulges should be closely monitored. Coke drums can be inspected during turnaround with 3D Laser Scanning and Remote Visual Inspection (RVI) tools, resulting in a detailed dimensional and visual evaluation of the internal surface. A typical project has some goals: inspect the equipment to generate maintenance or inspection recommendations, comparison with previous results and baseline data. Until recently, coke drum structural analysis has been traditionally performed analyzing Stress Concentration Factors (SCF) thought Finite Element Analysis methods; however this technique has some serious technical and practical limitations. To avoid these shortcomings, the new strain analysis technique PSI (Plastic Strain Index) was developed. This method which is based on API 579/ ASME FFS standard failure limit represents the state of the art of coke drum bulging severity assessment has an excellent correlation with failure history. (author)

  4. The Evaluation of a Squid-Based Non-Contact Magnetic Nde Technique for Application to the Inspection of Offshore Steel Structures

    Science.gov (United States)

    Evanson, S.

    1988-12-01

    Available from UMI in association with The British Library. Requires signed TDF. Conventional methods of Non Destructive Evaluation (NDE) for the detection of surface-breaking defects in steel structures require intimate contact with the test site. This is a serious limitation in offshore inspection where the structure may be covered with tenacious marine contamination up to 0.5m thick. A method of magnetic examination to detect surface-breaking defects at distances, from a steel specimen, in excess of 10cm is reported. A persistent mode superconducting solenoid generates a DC magnetic field perpendicular to the specimen surface. The spatial distortion of this field by surface defects is detected using a SQUID coupled to a novel planar gradiometer, coaxial with the solenoid. DC operation means detection is unaffected by electrically conductive surface coatings. A point defect is represented by an equivalent magnetic dipole and a long defect by a line dipole with a uniformly distributed magnetic moment. Mathematical models for the response of a gradiometer to magnetic dipole sources are used to design a suitable planar gradiometer. Theoretical and experimental data demonstrate the superior performance of this design compared with a conventional second order gradiometer of the type available commercially. The construction of a system for acquisition and computer processing of data from the examination of steel specimens is discussed. Extensive tests were conducted on flat steel plates containing ideal surface defects and good agreement is found with the defect models. The major limitation on defect resolution is a background field associated with the magnetised steel plate. Background components of low spatial frequency are reduced by balancing the gradiometer, further improvement in resolution is achieved by applying band pass digital filters to the SQUID output. A SQUID system offers considerable promise for remote detection of surface defects in plane steel

  5. Multilayer defects nucleated by substrate pits: a comparison of actinic inspection and non-actinic inspection techniques

    Energy Technology Data Exchange (ETDEWEB)

    Barty, A; Goldberg, K; Kearney, P; Rekawa, S; LaFontaine, B; Wood, O; Taylor, J S; Han, H

    2006-10-02

    The production of defect-free mask blanks remains a key challenge for EUV lithography. Mask-blank inspection tools must be able to accurately detect all critical defects while simultaneously having the minimum possible false-positive detection rate. We have recently observed and here report the identification of bump-type buried substrate defects, that were below the detection limit of a non-actinic (i.e. non-EUV) in inspection tool. Presently, the occurrence inspection of pit-type defects, their printability, and their detectability with actinic techniques and non-actinic commercial tools, has become a significant concern. We believe that the most successful strategy for the development of effective non-actinic mask inspection tools will involve the careful cross-correlation with actinic inspection and lithographic printing. In this way, the true efficacy of prototype inspection tools now under development can be studied quantitatively against relevant benchmarks. To this end we have developed a dual-mode actinic mask inspection system capable of scanning mask blanks for defects (with simultaneous EUV bright-field and dark-field detection) and imaging those same defects with a zoneplate microscope that matches or exceeds the resolution of EUV steppers.

  6. Performance-based inspection and maintenance strategies

    Energy Technology Data Exchange (ETDEWEB)

    Vesely, W.E.

    1995-04-01

    Performance-based inspection and maintenance strategies utilize measures of equipment performance to help guide inspection and maintenance activities. A relevant measure of performance for safety system components is component unavailability. The component unavailability can also be input into a plant risk model such as a Probabilistic Risk Assessment (PRA) to determine the associated plant risk performance. Based on the present and projected unavailability performance, or the present and projected risk performance, the effectiveness of current maintenance activities can be evaluated and this information can be used to plan future maintenance activities. A significant amount of information other than downtimes or failure times is collected or can be collected when an inspection or maintenance is conducted which can be used to estimate the component unavailability. This information generally involves observations on the condition or state of the component or component piecepart. The information can be detailed such as the amount of corrosion buildup or can be general such as the general state of the component described as {open_quotes}high degradation{close_quotes}, {open_quotes}moderate degradation{close_quotes}, or {open_quotes}low degradation{close_quotes}. Much of the information collected in maintenance logs is qualitative and fuzzy. As part of an NRC Research program on performance-based engineering modeling, approaches have been developed to apply Fuzzy Set Theory to information collected on the state of the component to determine the implied component or component piecepart unavailability. Demonstrations of the applications of Fuzzy Set Theory are presented utilizing information from plant maintenance logs. The demonstrations show the power of Fuzzy Set Theory in translating engineering information to reliability and risk implications.

  7. Reliability-Based Inspection Planning for Structural Systems

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    1993-01-01

    A general model for reliability-based optimal inspection and repair strategies for structural systems is described. The total expected costs in the design lifetime is minimized with the number of inspections, the inspection times and efforts as decision variables. The equivalence of this model wi...

  8. Generic Reliability-Based Inspection Planning for Fatigue Sensitive Details

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Straub, Daniel; Faber, Michael Havbro

    2005-01-01

    of fatigue sensitive details in fixed offshore steel jacket platforms and FPSO ship structures. Inspection and maintenance activities are planned such that code based requirements to the safety of personnel and environment for the considered structure are fulfilled and at the same time such that the overall......The generic approach for planning of in-service NDT inspections is extended to cover the case where the fatigue load is modified during the design lifetime of the structure. Generic reliability-based inspection planning has been developed as a practical approach to perform inspection planning...... expected costs for design, inspections, repairs and failures are minimized. The method is based on the assumption of “no-finds” of cracks during inspections. Each fatigue sensitive detail is categorized according to their type of details (SN curves), FDF values, RSR values, inspection, repair and failure...

  9. Vibrational Based Inspection of Civil Engineering Structures

    DEFF Research Database (Denmark)

    Rytter, Anders

    at the University of Aalborg from 1988 to 1991. Secondly, a research project, In-Field Vibration Based Inspection of Civil Engineering Structures, which has been performed as a pilot project by the Consulting Engineers Rambøll, Hannemann and Højlund in cooperation with the department of Building Technology......The thesis has been written in relation to two different research projects. Firstly, an offshore test programme, Integrated Experimental/Numerical Analysis of the Dynamic behavior of offshore structures, which was performed at the department of Building Technology and Structural Engineering...... and Structural Engineering at the University of Aalborg since the beginning of 1992. Both projects have been supported by the Danish Technical Research Council. Further, the first mentioned project was supported by the Danish Energy Agency. Their financial support is gratefully acknowledged....

  10. On qualification of TOFD technique for austenitic stainless steel welds inspection

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Ona, R. [Tecnatom, San Sebastian de los Reyes (Spain); Viggianiello, S.; Bleuze, A. [Metalscan, Saint-Remy (France)

    2006-07-01

    Time of Flight Diffraction (TOFD) technique is gaining ground as a solid method for detection and sizing of defects. It has been reported that TOFD technique provides good results on the inspection of fine grain steels. However, there are few results regarding the application and performance of this technique on austenitic stainless steels. A big challenge of these inspections is the coarse grain structure that produces low signal to noise ratio and may mask the diffraction signals. Appropriate transducer design, selection of technique parameters and analysis tools could overcome the actual difficulties. In this paper, the main design aspects and parameters of the TOFD technique for austenitic steels are presented. It follows the description of qualification tests carried out to validate the technique for inspecting stainless steels welds. To conclude, discussion of results from actual inspections is shown. (orig.)

  11. The line inspection system for yarn evenness based on digital image processing techniques%采用数字图像处理技术的条干均匀度在线检测系统

    Institute of Scientific and Technical Information of China (English)

    刘冀龙; 尹岗

    2016-01-01

    为了实现测量过程的自动化,提出了应用图像处理技术的条状物均匀度在线检测系统的设计方法.以交叉编译开发环境Qt Creator为核心,结合开源图像处理库OpenCV,实现了不规则条状物外尺寸的非接触式在线测量和实时显示.采用显微放大镜头,搭建了专用的光学系统;图像预处理采用最大类间方差法(Otsu),消除了不同光照强度对检测结果的影响;为了充分体现人机交互性而编写了友善的上位显示界面,采用MATLAB对采集到的数据进行曲线拟合,验证了分段直线拟合的可行性.实验结果表明,该装置结构简单,测量结果准确,使纺织品条干均匀度在线实时检测成为可能.%In order to realize automatic measurement,a yarn inspection system based on digital image processing techniques was designed.Using Qt Creator as the core IDE,combined with the Open Source Computer Vision Library(OpenCV),to realize the non-touching on-line measurement of yarn evenness and real-time transmission & display.Based on the microscopy camera,the corresponding optical system was designed and constructed;in order to eliminate the effects of different light intensities,one adaptive threshold segmentation method was proposed,based on Otsu threshold method;to build a good Human-Computer Interaction experience,the friendly GUI of the system displaying was written and compiled.Finally the Sub-fitting results were carried out on the MATLAB.The experimental results show that the system has the advantages of simple structure,accurate measurement result and high precision,making the stem diameter line real-time inspection is possible.

  12. Thermal wave imaging techniques for inspection of plywood materials

    Science.gov (United States)

    Mulaveesala, Ravibabu; Venkata Nagarjuna, P.; Ravi, Dadda; Amarnath, Muniyappa

    2012-06-01

    Infrared non-destructive testing and evaluation (IRNDT&E) is an emerging approach for materials characterization due to its capability to test wide variety of solid materials such as metals, composites and semiconductors of industrial interest. Further it supports thorough inspection and evaluation by its unique remote and fast and whole field testing capabilities. Wood is one of the most commonly used house hold building material it has both structural and decorative applications. It is used both in natural and processed form like ply wood, veneer, ply-board etc. Defects like knots, worm track, delaminations, glue smear etc. influences its in-service capabilities. Even though various non-destructive methods such as optical, ultrasonic and radiography are commonly used to inspect wooden materials, infrared imaging has its own advantage due to its safe, whole field inspection capabilities. This paper describes the applicability of the transient thermal wave imaging (TWI) method for inspection of ply wood. This paper highlights applicability of transient pulsed thermal imaging approach for finding out the hidden defects. Capability of the proposed method and its defect detection capabilities have been highlighted through experimental results.

  13. Benefits of Risk Based Inspection Planning for Offshore Structures

    DEFF Research Database (Denmark)

    Straub, D.M.; Goyet, J.; Sørensen, John Dalsgaard

    2006-01-01

    The economical benefits of applying risk-based inspection planning (RBI) for offshore structures subject to fatigue are evaluated based on experiences from past industrial projects. To this end, the factors influencing the cost of inspection, repair and failure of structures are discussed......, the financial benefit of RBI is assessed....

  14. Reliability-Based Maintenance and Inspection Planning for Wind Turbines

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    2004-01-01

    , local buckling of main tower, and failure of the foundation. This paper considers reliability-based optimal inspection and maintenance planning of wind turbines. Different formulations are considered of the objective function including benefits, building costs of the wind turbine, inspection...... and maintenance costs, and failure costs. Different reconstruction policies in case of failure are considered, including systematic reconstruction in case of failure, no reconstruction and failure of the control system. The concept of generic inspection and maintenance planning coupled with information from...

  15. 3D LASER SCANNING TECHNIQUE FOR THE INSPECTION AND MONITORING OF RAILWAY TUNNELS

    OpenAIRE

    2015-01-01

    Railway tunnel inspection and monitoring has predominantly been a visual and manual procedure, which is time-consuming and subjective, giving rise to variance in standards and quality. Thus, alternative, novel, automated techniques need to be developed, for more efficient and reliable tunnel examination. The reported research aimed to investigate the application of a laser scanning technique for the inspection of tunnel degradation and structural integrity. The proposed method may either subs...

  16. A PLM-based automated inspection planning system for coordinate measuring machine

    Science.gov (United States)

    Zhao, Haibin; Wang, Junying; Wang, Boxiong; Wang, Jianmei; Chen, Huacheng

    2006-11-01

    With rapid progress of Product Lifecycle Management (PLM) in manufacturing industry, automatic generation of inspection planning of product and the integration with other activities in product lifecycle play important roles in quality control. But the techniques for these purposes are laggard comparing with techniques of CAD/CAM. Therefore, an automatic inspection planning system for Coordinate Measuring Machine (CMM) was developed to improve the automatization of measuring based on the integration of inspection system in PLM. Feature information representation is achieved based on a PLM canter database; measuring strategy is optimized through the integration of multi-sensors; reasonable number and distribution of inspection points are calculated and designed with the guidance of statistic theory and a synthesis distribution algorithm; a collision avoidance method is proposed to generate non-collision inspection path with high efficiency. Information mapping is performed between Neutral Interchange Files (NIFs), such as STEP, DML, DMIS, XML, etc., to realize information integration with other activities in the product lifecycle like design, manufacturing and inspection execution, etc. Simulation was carried out to demonstrate the feasibility of the proposed system. As a result, the inspection process is becoming simpler and good result can be got based on the integration in PLM.

  17. Inspection Based Evaluation of a Danish Road Bridge

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    In this paper it is shown how an inspection-based evaluation of a Danish road bridge may be performed using the BRIDGE1 and BRIDGE2 bridge management systems produced within the EC-supported research programme "Assessment of Performance and Optimal Strategies for Inspection and Maintenance...

  18. Vision Based Autonomous Robotic Control for Advanced Inspection and Repair

    Science.gov (United States)

    Wehner, Walter S.

    2014-01-01

    The advanced inspection system is an autonomous control and analysis system that improves the inspection and remediation operations for ground and surface systems. It uses optical imaging technology with intelligent computer vision algorithms to analyze physical features of the real-world environment to make decisions and learn from experience. The advanced inspection system plans to control a robotic manipulator arm, an unmanned ground vehicle and cameras remotely, automatically and autonomously. There are many computer vision, image processing and machine learning techniques available as open source for using vision as a sensory feedback in decision-making and autonomous robotic movement. My responsibilities for the advanced inspection system are to create a software architecture that integrates and provides a framework for all the different subsystem components; identify open-source algorithms and techniques; and integrate robot hardware.

  19. INSPECTING COMPLIANCE TO MANY RULES: AN AGENT-BASED MODEL

    Directory of Open Access Journals (Sweden)

    Slaven Smojver

    2016-12-01

    Full Text Available Ever increasing scope and complexity of regulations and other rules that govern human society emphasise importance of the inspection of compliance to those rules. Often-used approaches to the inspection of compliance suffer from drawbacks such as overly idealistic assumptions and narrowness of application. Specifically, inspection models are frequently limited to situations where inspected entity has to comply with only one rule. Furthermore, inspection strategies regularly overlook some useful and available information such as varying costs of compliance to different rules. This article presents an agent-based model for inspection of compliance to many rules, which addresses abovementioned drawbacks. In the article, crime economic, game-theoretic and agent-based modelling approaches to inspection are briefly described, as well as their impact on the model. The model is described and simulation of a simplified version of the model is presented. The obtained results demonstrate that inspection strategies which take into account rules’ compliance costs perform significantly better than random strategies and better than cycle-based strategies. Additionally, the results encourage further, wider testing and validation of the model.

  20. Risk Based Inspection Planning of Ageing Structures

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Ersdal, Gerhard

    2008-01-01

    collapse of the structure. The importance of each component can be measured by the RIF (Residual Influence Factor) for each component and is illustrated by examples. When an installation becomes older then the number of fatigue critical components can be expected to increase. If the maximum acceptable....... Different approaches for updating inspection plans for older installations are considered in order to achieve decreased inspection intervals as the structure are ageing. The most promising method consists in increasing the rate of defects / crack initiation at the end of the expected lifetime. Different...

  1. Study of a risk-based piping inspection guideline system.

    Science.gov (United States)

    Tien, Shiaw-Wen; Hwang, Wen-Tsung; Tsai, Chih-Hung

    2007-02-01

    A risk-based inspection system and a piping inspection guideline model were developed in this study. The research procedure consists of two parts--the building of a risk-based inspection model for piping and the construction of a risk-based piping inspection guideline model. Field visits at the plant were conducted to develop the risk-based inspection and strategic analysis system. A knowledge-based model had been built in accordance with international standards and local government regulations, and the rational unified process was applied for reducing the discrepancy in the development of the models. The models had been designed to analyze damage factors, damage models, and potential damage positions of piping in the petrochemical plants. The purpose of this study was to provide inspection-related personnel with the optimal planning tools for piping inspections, hence, to enable effective predictions of potential piping risks and to enhance the better degree of safety in plant operations that the petrochemical industries can be expected to achieve. A risk analysis was conducted on the piping system of a petrochemical plant. The outcome indicated that most of the risks resulted from a small number of pipelines.

  2. Distributed heterogeneous inspecting system and its middleware-based solution

    Institute of Scientific and Technical Information of China (English)

    黄理灿; 吴朝晖; 潘云鹤

    2003-01-01

    There are many cases when an organization needs to monitor the data and operations of its super-vised departments, especially those departments which are not owned by this organization and are managed by their own information systems. Distributed Heterogeneous Inspecting System (DHIS) is the system an organization uses to monitor its supervised departments by inspecting their information systems. In DHIS, the inspected systems are generally distributed, heterogeneous, and constructed by different companies. DHIS has three key processes-abstracting core data sets and core operation sets, collecting these sets, and inspecting these collected sets. In this paper, we present the concept and mathematical definition of DHIS, a metadata method for solving the interoperability, a security strategy for data transferring, and a middleware-based solution of DHIS. We also describe an example of the inspecting system at WENZHOU custom.

  3. Distributed heterogeneous inspecting system and its middleware-based solution

    Institute of Scientific and Technical Information of China (English)

    黄理灿; 吴朝晖; 潘云鹤

    2003-01-01

    There are many cases when an organization needs to monitor the data and operations of its supervised departments, especially those departments which are not owned by this organization and are managed by their own information systems. Distributed Heterogeneous Inspecting System (DHIS) is the system an organization uses to monitor its supervised departments by inspecting their information systems. In DHIS, the inspected systems are generally distributed, heterogeneous, and constructed by different companies. DHIS has three key processes-abstracting core data sets and core operation sets, collecting these sets, and inspecting these collected sets. In this paper, we present the concept and mathematical definition of DHIS, a metadata method for solving the interoperability, a security strategy for data transferring, and a middleware-based solution of DHIS. We also describe an example of the inspecting system at WENZHOU custom.

  4. Overview of Some New Techniques for Inspection: Using 1950's Physics to Solve Modern Problems

    Science.gov (United States)

    Lanza, Richard

    2007-04-01

    The goal of any inspection technique is to non-intrusively determine the presence of such materials in a manner which is consistent with not interrupting the normal scheme of commerce and which, at the same time, exhibits a high probability of detection and a low probability of false alarms. A great deal of work has been reported in the literature on neutron based techniques for the detection of explosives with by far the largest impetus coming from the requirements of the commercial aviation industry for the inspection of luggage and, to a lesser extent, cargo; for baggage, the major techniques are either x-ray based or are chemical trace detection methods which look for small traces of explosive residues. Nuclear techniques have been proposed for the detection of explosives and contraband for a number of years due to their ability to penetrate shielding and to identify the elemental composition of materials, thus leading to enhanced detection probability and lower false alarm rates. Nuclear techniques are virtually the only method which can both detect and identify the presence of fissile materials, either in the form of bulk material or assembled weapons. Some examples of current work in nuclear based systems currently under development will be discussed such as nuclear resonance radiography, nuclear resonance fluorescence, pulsed fast neutron analysis and pulsed photonuclear detection. The physical basis of these techniques is well known, the physics having been studied in the 1950's, but there remain limitations on current technology with respect to e.g. radiation sources and detectors and data acquisition methods. Accelerator-based systems often are large and are often not well suited for field use; radiation detectors often suffer from limited count rate ability, low sensitivity and poor energy resolution and data acquisition and analysis methods usually rely on analog techniques which are not always stable in field operation. Current research in basic

  5. Optimal Risk-Based Inspection Planning for Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Rangel-Ramirez, Jose G.; Sørensen, John Dalsgaard

    2008-01-01

    Wind turbines for electricity production have increased significantly the last years both in production capability and size. This development is expected to continue also in the coining years. The Support structure for offshore wind turbines is typically a steel structure consisting of a tower......, inspection and maintenance activities are developed. This paper considers aspects of inspection and maintenance planning of fatigue prone details in jacket and tripod types of wind turbine support structures. Based oil risk-based inspection planning methods used for oil & gas installations, a framework...

  6. Optimal Risk-Based Inspection Planning for Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Ramírez, José G. Rangel; Sørensen, John Dalsgaard

    2008-01-01

    Wind turbines for electricity production have increased significantly the last years both in production capability and size. This development is expected to continue also in the coming years. The support structure for offshore wind turbines is typically a steel structure consisting of a tower......, inspection and maintenance activities are developed. This paper considers aspects of inspection and maintenance planning of fatigue prone details in jacket and tripod types of wind turbine support structures. Based on risk-based inspection planning methods used for oil & gas installations, a framework...

  7. Management of Microbiologically Influenced Corrosion in Risk Based Inspection analysis

    DEFF Research Database (Denmark)

    Skovhus, Torben Lund; Hillier, Elizabeth; Andersen, Erlend S.

    2016-01-01

    in the offshore industry as a means to justify the inspection strategy adopted. The RBI analysis is a decision-making technique that enables asset managers to identify the risk related to failure of their most critical systems and components, with an effect on safety, environmental and business related issues....... Microbiologically Influenced Corrosion (MIC) is a degradation mechanism that has received increased attention from corrosion engineers and asset operators in the past decades. In this paper, the most recent models that have been developed in order to assess the impact of MIC on asset integrity will be presented...... and discussed. From a risk perspective, MIC is not satisfactorily assessed by the current models and the models lack a proper view of the MIC threat. Therefore, a review of known parameters that affect MIC is presented. The mapping and identification of parameters is based on the review of past models...

  8. Inspection Workshop-6: OSI Technologies: Methodologies and Techniques for Application

    Energy Technology Data Exchange (ETDEWEB)

    Krioutchenkov, V.; Shchukin, V.; Sweeney, J.J.

    2000-09-14

    On-Site Inspection (OSI) Workshop-6 met 26-30 June 2000 in Vienna, hosted by the Provisional Technical Secretariat (PTS) of the CTBT Organization. The purpose of the workshop was to provide guidance on OSI Operational Manual (OM) development for Working Group B (WGB) of the CTBT preparatory Commission (PrepCom) in the general areas of equipment and logistics. The two main sessions of this workshop, titled ''OSI Equipment: Development of Functional and Operational Requirements, Specifications and Application Procedures'' and ''OSI Logistics: Continued Work on Standing Arrangements, Status of Inspectors and Support Equipment Issues'' reflected this focus. For this workshop, the schedule of work was divided into two parts: The first half of the week were sessions with formal paper presentations and discussion; the latter half of the week used two smaller subgroups to focus on and discuss separately equipment and logistics issues. Drawing heavily on the results of the five previous workshops, these subgroups produced material to be considered by Working Group B. This provisional material is intended to advance the process of equipment definition and procurement and establish procedures for logistics that can be incorporated into the OSI Operational Manual. The participants agreed that using subgroups in this workshop was an especially effective mechanism for discussion of different expert opinion on technical issues, and that having access to material presented at the previous five OSI workshops was particularly valuable.

  9. [Spectroscopy technique and ruminant methane emissions accurate inspecting].

    Science.gov (United States)

    Shang, Zhan-Huan; Guo, Xu-Sheng; Long, Rui-Jun

    2009-03-01

    The increase in atmospheric CH4 concentration, on the one hand through the radiation process, will directly cause climate change, and on the other hand, cause a lot of changes in atmospheric chemical processes, indirectly causing climate change. The rapid growth of atmospheric methane has gained attention of governments and scientists. All countries in the world now deal with global climate change as an important task of reducing emissions of greenhouse gases, but the need for monitoring the concentration of methane gas, in particular precision monitoring, can be scientifically formulated to provide a scientific basis for emission reduction measures. So far, CH4 gas emissions of different animal production systems have received extensive research. The methane emission by ruminant reported in the literature is only estimation. This is due to the various factors that affect the methane production in ruminant, there are various variables associated with the techniques for measuring methane production, the techniques currently developed to measure methane are unable to accurately determine the dynamics of methane emission by ruminant, and therefore there is an urgent need to develop an accurate method for this purpose. Currently, spectroscopy technique has been used and is relatively a more accurate and reliable method. Various spectroscopy techniques such as modified infrared spectroscopy methane measuring system, laser and near-infrared sensory system are able to achieve the objective of determining the dynamic methane emission by both domestic and grazing ruminant. Therefore spectroscopy technique is an important methane measuring technique, and contributes to proposing reduction methods of methane.

  10. Monte Carlo parametric studies of neutron interrogation with the Associated Particle Technique for cargo container inspections

    Science.gov (United States)

    Deyglun, Clément; Carasco, Cédric; Pérot, Bertrand

    2014-06-01

    The detection of Special Nuclear Materials (SNM) by neutron interrogation is extensively studied by Monte Carlo simulation at the Nuclear Measurement Laboratory of CEA Cadarache (French Alternative Energies and Atomic Energy Commission). The active inspection system is based on the Associated Particle Technique (APT). Fissions induced by tagged neutrons (i.e. correlated to an alpha particle in the DT neutron generator) in SNM produce high multiplicity coincidences which are detected with fast plastic scintillators. At least three particles are detected in a short time window following the alpha detection, whereas nonnuclear materials mainly produce single events, or pairs due to (n,2n) and (n,n'γ) reactions. To study the performances of an industrial cargo container inspection system, Monte Carlo simulations are performed with the MCNP-PoliMi transport code, which records for each neutron history the relevant information: reaction types, position and time of interactions, energy deposits, secondary particles, etc. The output files are post-processed with a specific tool developed with ROOT data analysis software. Particles not correlated with an alpha particle (random background), counting statistics, and time-energy resolutions of the data acquisition system are taken into account in the numerical model. Various matrix compositions, suspicious items, SNM shielding and positions inside the container, are simulated to assess the performances and limitations of an industrial system.

  11. Remote Inspection Techniques for Reactor Internals of Liquid Metal Reactor by using Ultrasonic Waveguide Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Young Sang; Kim, Seok Hun; Lee, Jae Han

    2006-02-15

    The primary components such as a reactor core, heat exchangers, pumps and internal structures of a liquid metal reactor (LMR) are submerged in hot sodium of reactor vessel. The division 3 of ASME code section XI specifies the visual inspection and continuous monitoring as major in-service inspection (ISI) methods of reactor internal structures. Reactor core and internal structures of LMR can not be visually examined due to an opaque liquid sodium. The under-sodium viewing and remote inspection techniques by using an ultrasonic wave should be applied for the in-service inspection of reactor internals. The remote inspection techniques using ultrasonic wave have been developed and applied for the visualization and ISI of reactor internals. The under sodium viewing technique has a limitation for the application of LMR due to the high temperature and irradiation environment. In this study, an ultrasonic waveguide sensor with a strip plate has been developed for an application to the under-sodium viewing and remote inspection. The Lamb wave propagation of a waveguide sensor has been analyzed and the zero-order antisymmetric A{sub 0} plate wave was selected as the application mode of the sensor. The A{sub 0} plate wave can be propagated in the dispersive low frequency range by using a liquid wedge clamped to the waveguide. A new technique is presented which is capable of steering the radiation beam angle of a waveguide sensor without a mechanical movement of the sensor assembly. The steering function of the ultrasonic radiation beam can be achieved by a frequency tuning method of the excitation pulse in the dispersive range of the A{sub 0} mode. The technique provides an opportunity to overcome the scanning limitation of a waveguide sensor. The beam steering function has been evaluated by an experimental verification. The ultrasonic C-scanning experiments are performed in water and the feasibility of the ultrasonic waveguide sensor has been verified. The various remote

  12. Development of outdoor luminescence imaging for drone-based PV array inspection

    DEFF Research Database (Denmark)

    Benatto, Gisele Alves dos Reis; Thorsteinsson, Sune; Riedel, Nicholas

    2017-01-01

    This work has the goal to perform outdoor defect detection imaging that will be used in a fast, accurate and automatic drone-based survey system for PV power plants. The imaging development focuses on techniques that do not require electrical contact, permitting automatic drone inspections to be ...

  13. Development of outdoor luminescence imaging for drone-based PV array inspection

    DEFF Research Database (Denmark)

    Benatto, Gisele Alves dos Reis; Thorsteinsson, Sune; Riedel, Nicholas

    2017-01-01

    This work has the goal to perform outdoor defect detection imaging that will be used in a fast, accurate and automatic drone-based survey system for PV power plants. The imaging development focuses on techniques that do not require electrical contact, permitting automatic drone inspections...

  14. Nuclear techniques for the inspection of blast furnaces

    Science.gov (United States)

    Schweitzer, J. S.; Lanza, R. C.

    1999-06-01

    Carbon hearth wall failures in blast furnaces create safety risks and require a large expense to repair. To avoid failures they are replaced early, incurring costs in wasted hearth wall use. Two non-invasive measurements provide realtime analysis of wall integrity. The two major failure modes are erosion of carbon thickness and iron-filled cracks in the bricks. Measurements of backscattered gamma-ray spectra and thermal neutron decay rate can identify both phenomena. Gamma-ray spectra from a compact Linac beam primarily respond to average carbon thickness. Neutron decay time, using a pulsed neutron source, is sensitive to iron in the carbon volume. Each measurement is sensitive to the other failure made, but the combination permits each phenomenon to be resolved. These techniques can detect a high atomic number and thermal neutron absorption cross section material behind one of low atomic number and thermal neutron absorption cross section.

  15. Optical triangulation-based microtopographic inspection of surfaces.

    Science.gov (United States)

    Costa, Manuel F M

    2012-01-01

    The non-invasive inspection of surfaces is a major issue in a wide variety of industries and research laboratories. The vast and increasing range of surface types, tolerance requirements and measurement constraints demanded during the last decades represents a major research effort in the development of new methods, systems and metrological strategies. The discreet dimensional evaluation the rugometric characterization and the profilometric inspection seem to be insufficient in many instances. The full microtopographic inspection has became a common requirement. Among the different systems developed, optical methods have the most important role and among those triangulation-based ones have gained a major status thanks to their flexibility, reliability and robustness. In this communication we will provide a brief historical review on the development of optical triangulation application to the dimensional inspection of objects and surfaces and on the work done at the Microtopography Laboratory of the Physics Department of the University of Minho, Portugal, in the development of methods and systems of optical triangulation-based microtopographic inspection of surfaces.

  16. A noncontacting scanning photoelectron emission technique for bonding surface cleanliness inspection

    Science.gov (United States)

    Gause, Raymond L.

    1989-01-01

    Molecular contamination of bonding surfaces can drastically affect the bond strength that can be achieved and therefore the structural integrity and reliability of the bonded part. The presence of thin contaminant films on bonding surfaces can result from inadequate or incomplete cleaning methods, from oxide growth during the time between cleaning (such as grit blasting) and bonding, or from failure to properly protect cleaned surfaces from oils, greases, fingerprints, release agents, or deposition of facility airborne molecules generated by adjacent manufacturing or processing operations. Required cleanliness levels for desired bond performance can be determined by testing to correlate bond strength with contaminant type and quantity, thereby establishing the degree of contamination that can be tolerated based on the strength that is needed. Once the maximum acceptable contaminant level is defined, a method is needed to quantitatively measure the contaminant level on the bonding surface prior to bonding to verify that the surface meets the established cleanliness requirement. A photoelectron emission technique for the nondestructive inspection of various bonding surfaces, both metallic and nonmetallic, to provide quantitative data on residual contaminant levels is described. The technique can be used to scan surfaces at speeds of at least 30 ft/min using a servo system to maintain required sensor to surface spacing. The fundamental operation of the photoelectron emission sensor system is explained and the automated scanning system and computer data acquisition hardware and software are described.

  17. Reliability-based optimum inspection and maintenance procedures. [for engines

    Science.gov (United States)

    Nanagud, S.; Uppaluri, B.

    1975-01-01

    The development of reliability-based optimum inspection and maintenance schedules for engines needs an understanding of the fatigue behavior of the engines. Critical areas of the engine structure prone to fatigue damage are usually identified beforehand or after the fleet has been put into operation. In these areas, fatigue cracks initiate after several flight hours, and these cracks grow in length until failure takes place when these cracks attain the critical lengths. Crack initiation time and its growth rate are considered to be random variables. Usually, the inspection (fatigue) or test data from similar engines are used as prior distributions. The existing state-of-the-art is to ignore the different lengths of cracks obserbed at various inspections and to consider only the fact that a crack existed (or did not exist) at the time of inspection. In this paper, a procedure has been developed to obtain the probability of finding a crack of a given size at a certain time if the probability distributions for crack initiation and rates of growth are known. Application of the developed stochastic models to devise optimum procedures for inspection and maintenance are also discussed.

  18. Risk-based Inspection Planning Optimisation of Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Ramirez, José Rangel; Sørensen, John Dalsgaard

    2011-01-01

    Wind industry is substantially propelled and the future scenarios designate offshore locations as important sites for energy production. With this development, offshore wind farms represent a feasible option to accomplish the needed energy, bringing with it technical and economical challenges....... Inspection and maintenance (I&M) costs for offshore sites are much larger than for onshore ones, making the choice of suitable I&M planning for minimising costs important. Risk-based inspection planning (RBI) for offshore installations represents a suitable methodology to identify the optimal maintenance...

  19. Bionic Vision-Based Intelligent Power Line Inspection System.

    Science.gov (United States)

    Li, Qingwu; Ma, Yunpeng; He, Feijia; Xi, Shuya; Xu, Jinxin

    2017-01-01

    Detecting the threats of the external obstacles to the power lines can ensure the stability of the power system. Inspired by the attention mechanism and binocular vision of human visual system, an intelligent power line inspection system is presented in this paper. Human visual attention mechanism in this intelligent inspection system is used to detect and track power lines in image sequences according to the shape information of power lines, and the binocular visual model is used to calculate the 3D coordinate information of obstacles and power lines. In order to improve the real time and accuracy of the system, we propose a new matching strategy based on the traditional SURF algorithm. The experimental results show that the system is able to accurately locate the position of the obstacles around power lines automatically, and the designed power line inspection system is effective in complex backgrounds, and there are no missing detection instances under different conditions.

  20. 3D LASER SCANNING TECHNIQUE FOR THE INSPECTION AND MONITORING OF RAILWAY TUNNELS

    Directory of Open Access Journals (Sweden)

    Han-Mei CHEN

    2015-12-01

    Full Text Available Railway tunnel inspection and monitoring has predominantly been a visual and manual procedure, which is time-consuming and subjective, giving rise to variance in standards and quality. Thus, alternative, novel, automated techniques need to be developed, for more efficient and reliable tunnel examination. The reported research aimed to investigate the application of a laser scanning technique for the inspection of tunnel degradation and structural integrity. The proposed method may either substitute or supplement traditional survey techniques, being more efficient, and contributing thus to the standardisation of tunnel inspections. For the purpose of investigating the applicability and accuracy of laser scanning in tunnels, a set of tunnel lining models was constructed for laboratory tests, with the objective of determining the quality of the imaging. Initial tests were carried out using a performant laser scanner and demonstrated the feasibility of the concept. As a result, refined laboratory models were built, and experiments conducted, to establish the quality and precision of laser scanning imaging, for condition monitoring of tunnels. The experimental results indicate that the laser scanning technique used in this research has high potential for detecting the tunnel condition, monitoring the depth of weathered mortar, spalling bricks etc. with high accuracy in static scanning mode.

  1. Inspection of the lids of shallowly buried concrete structures based on the propagation of surface waves

    Science.gov (United States)

    Tremblay, Simon-Pierre; Karray, Mourad; Chekired, Mohamed; Bessette, Carole; Jinga, Livius

    2017-01-01

    The inspection of underground concrete utility structures can be a challenging task due to their inaccessibility. This article presents a nondestructive inspection technique for the lids of such structures based on the propagation of elastic waves where the variation in soil vertical acceleration following an impact is recorded along a given line at the surface of the soil. The structures investigated are made of reinforced concrete and are located below a shallow homogeneous soil layer which is covered by a pavement. It is shown through finite difference numerical modeling that elastic waves are affected by the state of degradation of the underground concrete structure. It is also shown that the difference in dynamic properties between the soil and the concrete structure causes the latter to act as a waveguide that affects the variation of the vertical acceleration measured at the surface of the model. The propagation of elastic waves within different underground profiles is studied in terms of the variation of their energy and of their group and phase velocity. Theoretical models, computed using the propagator matrix technique, are presented in the appendix to demonstrate the importance of the waveguide effects, caused by the presence of the concrete structure, on the group and phase velocity dispersion curves of Rayleigh waves. Finally, some of the results obtained from the inspection of two different real underground structures are also presented. These results show that the proposed inspection technique, developed based on 1D and 2D numerical testing, is also effective for real structures.

  2. Fast in-situ tool inspection based on inverse fringe projection and compact sensor heads

    Science.gov (United States)

    Matthias, Steffen; Kästner, Markus; Reithmeier, Eduard

    2016-11-01

    Inspection of machine elements is an important task in production processes in order to ensure the quality of produced parts and to gather feedback for the continuous improvement process. A new measuring system is presented, which is capable of performing the inspection of critical tool geometries, such as gearing elements, inside the forming machine. To meet the constraints on sensor head size and inspection time imposed by the limited space inside the machine and the cycle time of the process, the measuring device employs a combination of endoscopy techniques with the fringe projection principle. Compact gradient index lenses enable a compact design of the sensor head, which is connected to a CMOS camera and a flexible micro-mirror based projector via flexible fiber bundles. Using common fringe projection patterns, the system achieves measuring times of less than five seconds. To further reduce the time required for inspection, the generation of inverse fringe projection patterns has been implemented for the system. Inverse fringe projection speeds up the inspection process by employing object-adapted patterns, which enable the detection of geometry deviations in a single image. Two different approaches to generate object adapted patterns are presented. The first approach uses a reference measurement of a manufactured tool master to generate the inverse pattern. The second approach is based on a virtual master geometry in the form of a CAD file and a ray-tracing model of the measuring system. Virtual modeling of the measuring device and inspection setup allows for geometric tolerancing for free-form surfaces by the tool designer in the CAD-file. A new approach is presented, which uses virtual tolerance specifications and additional simulation steps to enable fast checking of metric tolerances. Following the description of the pattern generation process, the image processing steps required for inspection are demonstrated on captures of gearing geometries.

  3. Interferometer -based Technology for Optical Nanoscale Inspection

    Directory of Open Access Journals (Sweden)

    Ryabko M.

    2014-02-01

    Full Text Available We demonstrate the interferometer-based approach for nanoscale grating Critical Dimension (CD measurements and prove the possibility to achieve no worse than 10 nm accuracy of measurements for 100 nm pitch gratings. The approach is based on phase shift measurement of light fields specularly reflected from periodical pattern and adjacent substrate with subsequent comparison between experimental and simulation results. RCWA algorithm is used to fit the measured results and extract the CD value. It is shown that accuracy of CD value measurement depends rather on the grating’s CD/pitch ratio than its CD value

  4. Application of risk-based inspection methods for cryogenic equipment

    CERN Document Server

    CERN. Geneva

    2016-01-01

    Risk-based Inspection (RBI) is widely applied across the world as part of Pressure Equipment Integrity Management, especially in the oil and gas industry, to generally reduce costs compared with time-based approaches and assist in assigning resources to the most critical equipment. One of the challenges in RBI is to apply it for low temperature and cryogenic applications, as there are usually no degradation mechanisms by which to determine a suitable probability of failure in the overall risk assessment. However, the assumptions used for other degradation mechanisms can be adopted to determine, qualitatively and semi-quantitatively, a consequence of failure within the risk assessment. This can assist in providing a consistent basis for the assumptions used in ensuring adequate process safety barriers and determining suitable sizing of relief devices. This presentation will discuss risk-based inspection in the context of cryogenic safety, as well as present some of the considerations for the risk assessme...

  5. Realtime Vision-Based Surface Defect Inspection of Steel Balls

    Institute of Scientific and Technical Information of China (English)

    Wang Zhong; Xing Qian; Fu Luhua; Sun Hong

    2015-01-01

    In the proposed system for online inspection of steel balls, a diffuse illumination is developed to enhance defect appearances and produce high quality images. To fully view the entire sphere, a novel unfolding method is put forward based on geometrical analysis, which only requires one-dimensional movement of the balls and a pair of cam-eras to capture images from different directions. Moreover, a realtime inspection algorithm is customized to improve both accuracy and efficiency. The precision and recall of the sample set were 87.7% and 98%, respectively. The aver-age time cost on image processing and analysis for a steel ballwas 47 ms, and the total time cost was less than 200 ms plus the cost of image acquisition and balls’ movement. The system can sort 18 000 balls per hour with a spatial reso-lution higher than 0.01 mm.

  6. Machine vision inspection of rice seed based on Hough transform

    Institute of Scientific and Technical Information of China (English)

    成芳; 应义斌

    2004-01-01

    A machine vision system was developed to inspect the quality of rice seeds. Five varieties of Jinyou402, Shanyou10, Zhongyou207, Jiayou and IIyou were evaluated. The images of both sides of rice seed with black background and white background were acquired with the image processing system for identifying external features of rice seeds. Five image sets consisting of 600 original images each were obtained. Then a digital image processing algorithm based on Hough transform was developed to inspect the rice seeds with incompletely closed glumes. The algorithm was implemented with all image sets using a Matlab 6.5 procedure. The results showed that the algorithm achieved an average accuracy of 96% for normal seeds, 92% for seeds with fine fissure and 87% for seeds with incompletely closed glumes. The algorithm was proved to be applicable to different seed varieties and insensitive to the color of the background.

  7. Machine vision inspection of rice seed based on Hough transform

    Institute of Scientific and Technical Information of China (English)

    成芳; 应义斌

    2004-01-01

    A machine vision system was developed to inspect the quality of rice seeds. Five varieties of Jinyou402,Shanyou 10, Zhongyou207, Jiayou and Ilyou were evaluated. The images of both sides of rice seed with black background and white background were acquired with the image processing system for identifying external features of rice seeds. Five image sets consisting of 600 original images each were obtained. Then a digital image processing algorithm based on Hough transform was developed to inspect the rice seeds with incompletely closed glumes. The algorithm was implemented with all image sets using a Matlab 6.5 procedure. The results showed that the algorithm achieved an average accuracy of 96% for normal seeds, 92% for seeds with fine fissure and 87% for seeds with incompletely closed glumes. The algorithm was proved to be applicable to different seed varieties and insensitive to the color of the background.

  8. High precision ultrasonic guided wave technique for inspection of power transmission line

    Science.gov (United States)

    Cheng, Jun; Qiu, Jinhao; Ji, Hongli; Wang, Enrong; Takagi, Toshiyuki; Uchimoto, Tetsuya

    2017-01-01

    Due to the merits of high inspection speed and long detecting distance, Ultrasonic Guided Wave(UGW) method has been commonly applied to the on-line maintenance of power transmission line. However, the guided wave propagation in this structure is very complicated, leading to the unfavorable defect localization accuracy. Aiming at this situation, a high precision UGW technique for inspection of local surface defect in power transmission line is proposed. The technique is realized by adopting a novel segmental piezoelectric ring transducer and transducer mounting scheme, combining with the comprehensive characterization of wave propagation and circumferential defect positioning with multiple piezoelectric elements. Firstly, the propagation path of guided waves in the multi-wires of transmission line under the proposed technique condition is investigated experimentally. Next, the wave velocities are calculated by dispersion curves and experiment test respectively, and from comparing of the two results, the guided wave mode propagated in transmission line is confirmed to be F(1,1) mode. Finally, the axial and circumferential positioning of local defective wires in transmission line are both achieved, by using multiple piezoelectric elements to surround the stands and send elastic waves into every single wire. The proposed research can play a role of guiding the development of highly effective UGW method and detecting system for multi-wire transmission line.

  9. Application of proposed mutual reciprocal inspection measurement techniques to a weapon component

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, M.W.; Frankle, C.M. [Los Alamos National Lab., NM (United States); Gosnell, T.B. [Lawrence Livermore National Lab., CA (United States)

    1997-04-01

    The shape-measurement technique proposed by Russian scientists for mutual reciprocal inspections (MRI) of plutonium from dismantled nuclear weapons has been applied to a US weapon component. Measurement procedures are described. Results of the measurements are {open_quotes}self-normalized{close_quotes} to remove any classified information and further renormalized to results of previous joint US/Russian measurements of an unclassified plutonium piece. Data are presented in tabular and graphical form, conforming to the method of presentation recommended by Russian experts during the previous measurements.

  10. A new etch-aware after development inspection (ADI) technique for OPC modeling

    Science.gov (United States)

    Xue, Jing; Huang, Jason; Kazarian, Aram; Falch, Brad

    2010-04-01

    This paper presents a new etch-aware after development inspection (ADI) model with an inverse etch bias filter. We model the etch bias as a function of pattern geometry parameters, and we introduce it to the ADI model by means of an inverse bias matrix that works in conjunction with an ADI specification related matrix. The inverse bias filter tunes the ADI model to be highly correlated to the etch effects and provides simplified and designable inputs to the after etch inspection (AEI) model and hence improves its performance over the staged modeling flow. In addition, the inverse bias filter creates a model based rule table for design retargeting. Some of the etch effects are corrected by the inverse bias filter as the lithography model is calibrated, thus speeding up and simplifying the etch AEI model, while maintaining lithography ADI model with a good accuracy.

  11. Evaluation of computer-based ultrasonic inservice inspection systems

    Energy Technology Data Exchange (ETDEWEB)

    Harris, R.V. Jr.; Angel, L.J.; Doctor, S.R.; Park, W.R.; Schuster, G.J.; Taylor, T.T. [Pacific Northwest Lab., Richland, WA (United States)

    1994-03-01

    This report presents the principles, practices, terminology, and technology of computer-based ultrasonic testing for inservice inspection (UT/ISI) of nuclear power plants, with extensive use of drawings, diagrams, and LTT images. The presentation is technical but assumes limited specific knowledge of ultrasonics or computers. The report is divided into 9 sections covering conventional LTT, computer-based LTT, and evaluation methodology. Conventional LTT topics include coordinate axes, scanning, instrument operation, RF and video signals, and A-, B-, and C-scans. Computer-based topics include sampling, digitization, signal analysis, image presentation, SAFI, ultrasonic holography, transducer arrays, and data interpretation. An evaluation methodology for computer-based LTT/ISI systems is presented, including questions, detailed procedures, and test block designs. Brief evaluations of several computer-based LTT/ISI systems are given; supplementary volumes will provide detailed evaluations of selected systems.

  12. Comparing thermal stimulation techniques in infrared thermographic inspection of corrosion in steel

    Science.gov (United States)

    Chulkov, A. O.; Vavilov, V. P.

    2015-04-01

    Remote detection of corrosion in metals is a developing application area of active thermal nondestructive testing. In this study, emphasis is made on the optimization of heating techniques that is of a major interest in practical surveys. Some popular data processing techniques, such as Fourier transform, correlation and principal component analysis, are also quantitatively compared in application to corrosion detection in 1-2 mm thick steel by applying a criterion of signal-to-noise ratio. The best inspection results have been obtained by using powerful halogen lamps and air blowers. Material loss of about 25% with lateral dimensions greater than 10×10 mm can be reliably identified in practical tests. The use of Xenon flash tubes is inefficient because of significant steel thickness. LED panels have not provided expected results due to low absorption of LED quasi-monochromatic radiation.

  13. Task-driven equipment inspection system based on safe workflow model

    Science.gov (United States)

    Guo, Xinyou; Liu, Yangguang

    2010-12-01

    An equipment inspection system is one that contains a number of equipment queues served in cyclic order. In order to satisfy multi-task scheduling and multi-task combination requirements for equipment inspection system, we propose a model based on inspection workflow in this paper. On the one hand, the model organizes all kinds of equipments according to inspection workflow, elemental work units according to inspection tasks, combination elements according to the task defined by users. We proposed a 3-dimensional workflow model for equipments inspection system including organization sub-model, process sub-model and data sub-model. On the other hand, the model is based on the security authorization which defined by relation between roles, tasks, pre-defined business workflows and inspection data. The system based on proposed framework is safe and efficient. Our implement shows that the system is easy to operate and manage according to the basic performance.

  14. Innovative Ultrasonic Techniques for Inspection and Monitoring of Large Concrete Structures

    Directory of Open Access Journals (Sweden)

    Niederleithinger E.

    2013-07-01

    Full Text Available Ultrasonic echo and transmission techniques are used in civil engineering on a regular basis. New sensors and data processing techniques have lead to many new applications in the structural investigation as well as quality control. But concrete structures in the nuclear sector have special features and parameters, which pose problems for the methods and instrumentation currently available, e.g. extreme thickness, dense reinforcement, steel liners or special materials. Several innovative ultrasonic techniques have been developed to deal with these issues at least partly in lab experiments and pilot studies. Modern imaging techniques as multi-offset SAFT have been used e. g. to map delaminations. Thick concrete walls have successfully been inspected, partly through a steel liner. Embedded ultrasonic sensors have been designed which will be used in monitoring networks of large concrete structures above and below ground. In addition, sensitive mathematical methods as coda wave interferometry have been successfully evaluated to detect subtle changes in material properties. Examples of measurements and data evaluation are presented.

  15. Innovative Ultrasonic Techniques for Inspection and Monitoring of Large Concrete Structures

    Science.gov (United States)

    Wiggenhauser, H.; Niederleithinger, E.

    2013-07-01

    Ultrasonic echo and transmission techniques are used in civil engineering on a regular basis. New sensors and data processing techniques have lead to many new applications in the structural investigation as well as quality control. But concrete structures in the nuclear sector have special features and parameters, which pose problems for the methods and instrumentation currently available, e.g. extreme thickness, dense reinforcement, steel liners or special materials. Several innovative ultrasonic techniques have been developed to deal with these issues at least partly in lab experiments and pilot studies. Modern imaging techniques as multi-offset SAFT have been used e. g. to map delaminations. Thick concrete walls have successfully been inspected, partly through a steel liner. Embedded ultrasonic sensors have been designed which will be used in monitoring networks of large concrete structures above and below ground. In addition, sensitive mathematical methods as coda wave interferometry have been successfully evaluated to detect subtle changes in material properties. Examples of measurements and data evaluation are presented.

  16. Linac based photofission inspection system employing novel detection concepts

    Science.gov (United States)

    Stevenson, John; Gozani, Tsahi; Elsalim, Mashal; Condron, Cathie; Brown, Craig

    2011-10-01

    Rapiscan Systems is developing a LINAC based cargo inspection system for detection of special nuclear material (SNM) in cargo containers. The system, called Photofission Based Alarm Resolution (PBAR) is being developed under a DHD/DNDO Advanced Technology Demonstration (ATD) program. The PBAR system is based on the Rapiscan Eagle P9000 X-ray system, which is a portal system with a commercial 9 MeV LINAC X-ray source. For the purposes of the DNDO ATD program, a conveyor system was installed in the portal to allow scanning and precise positioning of 20 ft ISO cargo containers. The system uses a two step inspection process. In the first step, the basic scan, the container is quickly and completely inspected using two independent radiography arrays: the conventional primary array with high spatial resolution and a lower resolution spectroscopic array employing the novel Z-Spec method. The primary array uses cadmium tungstate (CdWO 4) detectors with conventional current mode readouts using photodiodes. The Z-Spec array uses small plastic scintillators capable of performing very fast (up to 10 8 cps) gamma-ray spectroscopy. The two radiography arrays are used to locate high-Z objects in the image such as lead, tungsten, uranium, which could be potential shielding materials as well as SNM itself. In the current system, the Z-Spec works by measuring the energy spectrum of transmitted X-rays. For high-Z materials the higher end of the energy spectrum is more attenuated than for low-Z materials and thus has a lower mean energy and a narrower width than low- and medium-Z materials. The second step in the inspection process is the direct scan or alarm clearing scan. In this step, areas of the container image, which were identified as high Z, are re-inspected. This is done by precisely repositioning the container to the location of the high-Z object and performing a stationary irradiation of the area with X-ray beam. Since there are a large number of photons in the 9 MV

  17. Application of risk-based inspection to two pipelines of the TRANSPETRO network

    Energy Technology Data Exchange (ETDEWEB)

    Leinum, Bente; Bjornoy, Ola [Det Norske Veritas (DNV), Oslo (Norway); Oliveira, Luiz Fernando; Oliveira, Cassia [DNV Principia, Rio de Janeiro, RJ (Brazil); Garcia, Claudio Brito [PETROBRAS Transporte S.A. (TRANSPETRO), Rio de Janeiro, RJ (Brazil)

    2005-07-01

    Inspection and maintenance are a significant part of pipeline operations costs. The objective of this work is to present the results obtained with the application of Risk-Based Inspection to two gas pipelines operated by TRANSPETRO. Based on the current state of knowledge about the degradation mechanisms acting on either pipeline and their respective operating conditions, the RBI study recommended that both be inspected next year. Alternatively in one case, the study lays out the conditions by which the pipeline inspection can be postponed to 2007. TRANSPETRO had already decided to inspect the other pipeline this year (for reasons not related to this study) and therefore, the RBI approach is going to be re-applied after the new inspection results are available. This application will set the date for the next inspection. (author)

  18. Monte-Carlo Simulations of Radiation-Induced Activation in a Fast-Neutron and Gamma- Based Cargo Inspection System

    CERN Document Server

    Bromberger, B; Brandis, M; Dangendorf, V; Goldberg, M B; Kaufmann, F; Mor, I; Nolte, R; Schmiedel, M; Tittelmeier, K; Vartsky, D; Wershofen, H

    2012-01-01

    An air cargo inspection system combining two nuclear reaction based techniques, namely Fast-Neutron Resonance Radiography and Dual-Discrete-Energy Gamma Radiography is currently being developed. This system is expected to allow detection of standard and improvised explosives as well as special nuclear materials. An important aspect for the applicability of nuclear techniques in an airport inspection facility is the inventory and lifetimes of radioactive isotopes produced by the neutron and gamma radiation inside the cargo, as well as the dose delivered by these isotopes to people in contact with the cargo during and following the interrogation procedure. Using MCNPX and CINDER90 we have calculated the activation levels for several typical inspection scenarios. One example is the activation of various metal samples embedded in a cotton-filled container. To validate the simulation results, a benchmark experiment was performed, in which metal samples were activated by fast-neutrons in a water-filled glass jar. T...

  19. Application of dual-energy x-ray techniques for automated food container inspection

    Science.gov (United States)

    Shashishekhar, N.; Veselitza, D.

    2016-02-01

    Manufacturing for plastic food containers often results in small metal particles getting into the containers during the production process. Metal detectors are usually not sensitive enough to detect these metal particles (0.5 mm or lesser), especially when the containers are stacked in large sealed shipping packages; X-ray inspection of these packages provides a viable alternative. This paper presents the results of an investigation into dual-energy X-ray techniques for automated detection of small metal particles in plastic food container packages. The sample packages consist of sealed cardboard boxes containing stacks of food containers: plastic cups for food, and Styrofoam cups for noodles. The primary goal of the investigation was to automatically identify small metal particles down to 0.5 mm diameter in size or less, randomly located within the containers. The multiple container stacks in each box make it virtually impossible to reliably detect the particles with single-energy X-ray techniques either visually or with image processing. The stacks get overlaid in the X-ray image and create many indications almost identical in contrast and size to real metal particles. Dual-energy X-ray techniques were investigated and found to result in a clear separation of the metal particles from the food container stack-ups. Automated image analysis of the resulting images provides reliable detection of the small metal particles.

  20. High performance coated board inspection system based on commercial components

    CERN Document Server

    Barjaktarovic, M; Radunovic, J

    2007-01-01

    This paper presents a vision system for defect (fault) detection on a coated board developed using three industrial firewire cameras and a PC. Application for image processing and system control was realized with the LabView software package. Software for defect detection is based on a variation of the image segmentation algorithm. Standard steps in image segmentation are modified to match the characteristics of defects. Software optimization was accomplished using SIMD (Single Instruction Multiple Data) technology available in the Intel Pentium 4 processors that provided real time inspection capability. System provides benefits such as: improvement in production process, higher quality of delivered coated board and reduction of waste. This was proven during successful exploitation of the system for more than a year.

  1. Inspection of thin-walled pipe welds using mechanized ultrasonic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Lozev, M.; Spencer, R. [Edison Welding Inst., Columbus, OH (United States); Hodgkinson, D. [TransCanada PipeLines Ltd., Calgary, AB (Canada)

    2004-07-01

    This paper investigated applications of high-frequency single/multiprobe techniques and phased-array (PA) technology for the inspection of thin-walled pipes welds. Ultrasonic testing (UT), modeling and simulation was used as an effective way of determining that the desired calibration reflectors and flaws in thin-walled pipes can be accurately sized. A laboratory experiment was conducted in which simple or complex flaws were virtually split on several segments. Beam profile monitoring and automated ultrasonic testing was performed for non-focused 5, 10 and 15 MHz single elements, a variety of focused MHz elements, and a 10 MHz 32 element linear PA probe. A Mephisto model was used to examine the various echo-formation mechanisms. Beam interactions and connected planar flaws were examined. Two calibration targets were used: (1) a 1.5 mm diameter side-drilled hole; and (2) a 4 per cent deep notch. A thin-walled pipe sample was designed for the validation of modeling results. A commercially available PA system and computer software program was used to create focal laws, as well as to steer the beam, collect data, and perform the analysis. Results of the notch tilt models showed that inspection angles of approximately 58 to 68 degrees were the least sensitive to tilt. Signal amplitude losses of less than 10 decibels were observed when compared with the reference notch. The PA model for complex flaws showed that signal loss arising from tilt and skew stabilized at approximately 10 degrees due to a loss of amplitude. Larger sound beams resulted in a greater echo-dynamic that increased masking effects. It was concluded that the most accurate UT simulations were achieved using a 10 MHz, 32-element linear PA technology. 4 refs., 2 tabs., 8 figs.

  2. An Efficient Algorithm Embedded in an Ultrasonic Visualization Technique for Damage Inspection Using the AE Sensor Excitation Method

    Directory of Open Access Journals (Sweden)

    Yaolu Liu

    2014-10-01

    Full Text Available To improve the reliability of a Lamb wave visualization technique and to obtain more information about structural damages (e.g., size and shape, we put forward a new signal processing algorithm to identify damage more clearly in an inspection region. Since the kinetic energy of material particles in a damaged area would suddenly change when ultrasonic waves encounter the damage, the new algorithm embedded in the wave visualization technique is aimed at monitoring the kinetic energy variations of all points in an inspection region to construct a damage diagnostic image. To validate the new algorithm, three kinds of surface damages on the center of aluminum plates, including two non-penetrative slits with different depths and a circular dent, were experimentally inspected. From the experimental results, it can be found that the new algorithm can remarkably enhance the quality of the diagnostic image, especially for some minor defects.

  3. An efficient algorithm embedded in an ultrasonic visualization technique for damage inspection using the AE sensor excitation method.

    Science.gov (United States)

    Liu, Yaolu; Goda, Riu; Samata, Kiyoshi; Kanda, Atsushi; Hu, Ning; Zhang, Jianyu; Ning, Huiming; Wu, Liangke

    2014-10-29

    To improve the reliability of a Lamb wave visualization technique and to obtain more information about structural damages (e.g., size and shape), we put forward a new signal processing algorithm to identify damage more clearly in an inspection region. Since the kinetic energy of material particles in a damaged area would suddenly change when ultrasonic waves encounter the damage, the new algorithm embedded in the wave visualization technique is aimed at monitoring the kinetic energy variations of all points in an inspection region to construct a damage diagnostic image. To validate the new algorithm, three kinds of surface damages on the center of aluminum plates, including two non-penetrative slits with different depths and a circular dent, were experimentally inspected. From the experimental results, it can be found that the new algorithm can remarkably enhance the quality of the diagnostic image, especially for some minor defects.

  4. Risk Based Inspection Methodology and Software Applied to Atmospheric Storage Tanks

    Science.gov (United States)

    Topalis, P.; Korneliussen, G.; Hermanrud, J.; Steo, Y.

    2012-05-01

    A new risk-based inspection (RBI) methodology and software is presented in this paper. The objective of this work is to allow management of the inspections of atmospheric storage tanks in the most efficient way, while, at the same time, accident risks are minimized. The software has been built on the new risk framework architecture, a generic platform facilitating efficient and integrated development of software applications using risk models. The framework includes a library of risk models and the user interface is automatically produced on the basis of editable schemas. This risk-framework-based RBI tool has been applied in the context of RBI for above-ground atmospheric storage tanks (AST) but it has been designed with the objective of being generic enough to allow extension to the process plants in general. This RBI methodology is an evolution of an approach and mathematical models developed for Det Norske Veritas (DNV) and the American Petroleum Institute (API). The methodology assesses damage mechanism potential, degradation rates, probability of failure (PoF), consequence of failure (CoF) in terms of environmental damage and financial loss, risk and inspection intervals and techniques. The scope includes assessment of the tank floor for soil-side external corrosion and product-side internal corrosion and the tank shell courses for atmospheric corrosion and internal thinning. It also includes preliminary assessment for brittle fracture and cracking. The data are structured according to an asset hierarchy including Plant, Production Unit, Process Unit, Tag, Part and Inspection levels and the data are inherited / defaulted seamlessly from a higher hierarchy level to a lower level. The user interface includes synchronized hierarchy tree browsing, dynamic editor and grid-view editing and active reports with drill-in capability.

  5. Robot Based Preventive Maintenance System for In-Service Inspection of Equipments

    Directory of Open Access Journals (Sweden)

    Vimal Upadhyay

    2015-03-01

    Full Text Available The current tendency in the petrochemical plants and Aerospace industry is to save weight and life of the equipments in the processing units, in order to reduce costs and to ensure remaining life of components. The world of today is improving with respect to new technologies. As a result, new composites are added to material for gaining a new shape and structure of material. This has made it compulsory for new innovative in non destructive testing specially in ultrasonic inspection, from conventional ultrasonic based on pulse echo method to phased array methods. In parallel to this innovative in ultrasonic, mechanical manipulator have evolved for grinding and take a setup to unapproachable zones. Industrial robot with ultrasonic inspection developed in this paper, with the collaboration of Indian Oil Corporation, Faridabad, India. Which are bringing reliability, durability, accuracy, flexibility, good maintenance and reproducibility for different sizing components to in-service inspection? This paper focused on the evolution of in-service ultrasonic probe with mechanical manipulator in non destructive testing. This evolution system has led to the current scenario systems, where a perfect combination of innovative methods in ultrasonic techniques and robots is meet to our expected delivers.

  6. Feature-based tolerancing for intelligent inspection process definition

    Energy Technology Data Exchange (ETDEWEB)

    Brown, C.W.

    1993-07-01

    This paper describes a feature-based tolerancing capability that complements a geometric solid model with an explicit representation of conventional and geometric tolerances. This capability is focused on supporting an intelligent inspection process definition system. The feature-based tolerance model`s benefits include advancing complete product definition initiatives (e.g., STEP -- Standard for Exchange of Product model dam), suppling computer-integrated manufacturing applications (e.g., generative process planning and automated part programming) with product definition information, and assisting in the solution of measurement performance issues. A feature-based tolerance information model was developed based upon the notion of a feature`s toleranceable aspects and describes an object-oriented scheme for representing and relating tolerance features, tolerances, and datum reference frames. For easy incorporation, the tolerance feature entities are interconnected with STEP solid model entities. This schema will explicitly represent the tolerance specification for mechanical products, support advanced dimensional measurement applications, and assist in tolerance-related methods divergence issues.

  7. An Image Content Description Technique for the Inspection of Specular Objects

    Directory of Open Access Journals (Sweden)

    S. Bourennane

    2008-11-01

    Full Text Available This paper proposed an image content description method within the context of specular surface inspection. Such a method is based on a preliminary research concerning the generation of specific stripe patterns for the visual enhancement of defective surface parts of cylindrical specular objects. The goal of this paper is to address the stripe pattern interpretation within a general approach. For this purpose, different pattern recognition processes, consisting not only of the combination of different image segmentation, feature retrieval, and classification, but also of feature combination and selection, will be considered. Three top-down and one bottom-up approaches are evaluated for retrieving the most appropriate feature sets in terms of highest classification rates. It will be demonstrated that following a combination and appropriate selection of these feature sets, even better rates can be reached. With only half of the initial features, an increase of more than 2% is observable.

  8. Inspection system for welded tubular joint based on ultrasonic phased array

    Institute of Scientific and Technical Information of China (English)

    Hao Guangping; Deng Zongquan; Shan Baohua; Yu Weizhen; Li Lifang

    2010-01-01

    A manual inspection of large-diameter tubular joints is difficult. As a result a scanner with three degrees of freedom (DOFs) was developed based on the scanning principle of ultrasonic phased array. The weld tracing is realized by a 2D0F motion of scanner. The pose of ultrasonic probe is controlled by the third one. The control strategy is put forward based on a programmable multi-axis controller. Four kinds of scanning modes can be implemented simultaneously employing this ultrasonic inspection system. Experiments on reference blocks of tubular joints reveal that the automatic ultrasonic phased array inspection system has the same inspection accuracy as a manual ultrasonic inspection. This system is superior to the manual ultrasonic system in terms of reliability and repeatability. The artificial defects of weld at tubular joint can be detected accurately with the presented inspection system.

  9. DEVELOPMENT AND TEST OF BLIMP-BASED COMPACT LIDAR POWEWR-LINE INSPECTION SYSTEM

    Directory of Open Access Journals (Sweden)

    W. W. Pan

    2015-03-01

    Full Text Available This paper introduces a compact LIDAR system designed to inspect overhead transmission line for maintenance purposes. This LIDAR system is carried by a small unmanned helium airship, which is guided by GPS and laser ranging to fly automatically along the power-line over a limited distance. The 3D coordinates of the power line, power tower and power line channel features are gathered by LIDAR. Test have been accomplished using this blimp-based compact LIDAR power-line inspection system. Its inspections of a 500kV power lines also shows the high efficient inspection, less risk to personnel and more inspections per day compared with manual inspection.

  10. Sandy Damage Estimates Based on FEMA IA Registrant Inspection Data

    Data.gov (United States)

    Department of Housing and Urban Development — A FEMA housing inspection for renters is used to assess personal property loss and for owners to assess damage to their home as well as personal property. This...

  11. Non-contact inspection for inner surface of small-diameter pipes based on laser-PSD

    Institute of Scientific and Technical Information of China (English)

    WU En-qi; KE Ying-lin; LI Jiang-xiong

    2005-01-01

    A new non-contact inspection technique based on laser-PSD (position sensitive detector) to inspect the inner surface of small-diameter pipe is proposed,and the corresponding sensor has been developed.After being reflected by two mirrors in series,a laser beam is projected onto the inner wall of a pipe as a small light spot and is read by a two-dimensional PSD.Based on the signals from the PSD and the structure parameters of the sensor,the spot position on the wall can be calculated in a local 3D coordinate system.The spot controlled by the micro-motor driven mirrors will scan a closed section ring on the inner wall of the pipe to obtain the relative coordinates of all the sampled points.The data will be then processed through data segmentation and least square fitting,to reconstruct the section curve used for obtaining the radius and the defect description of the section.Driven by a micro-pipe robot,the sensor can inspect a long curved pipe and obtain its 3-D reconstruction.An inspection system based on this technique can detect the mini-diameter pipe with an inner diameter of 9.5 mm~10.5 mm and a curvature radius larger than 100 mm at a measurement accuracy of the inner surface defect of ±0.1 mm.

  12. Non-Intrusive Techniques of Inspections During the Pre-Launch Phase of Space Vehicle

    Science.gov (United States)

    Thirumalainambi, Rejkumar; Bardina, Jorge E.

    2005-01-01

    This paper addresses a method of non-intrusive local inspection of surface and sub-surface conditions, interfaces, laminations and seals in both space vehicle and ground operations with an integrated suite of imaging sensors during pre-launch operations. It employs an advanced Raman spectrophotometer with additional spectrophotometers and lidar mounted on a flying robot to constantly monitor the space hardware as well as inner surface of the vehicle and ground operations hardware. This paper addresses a team of micro flying robots with necessary sensors and photometers to monitor the entire space vehicle internally and externally. The micro flying robots can reach altitude with least amount of energy, where astronauts have difficulty in reaching and monitoring the materials and subsurface faults. The micro flying robot has an embedded fault detection system which acts as an advisory system and in many cases micro flying robots act as a Supervisor to fix the problems. As missions expand to a sustainable presence in the Moon, and extend for durations longer than one year in lunar outpost, the effectiveness of the instrumentation and hardware has to be revolutionized if NASA is to meet high levels of mission safety, reliability, and overall success. The micro flying robot uses contra-rotating propellers powered by an ultra-thin, ultrasonic motor with currently the world's highest power weight ratio, and is balanced in mid-air by means of the world's first stabilizing mechanism using a linear actuator. The essence of micromechatronics has been brought together in high-density mounting technology to minimize the size and weight. The robot can take suitable payloads of photometers, embedded chips for image analysis and micro pumps for sealing cracks or fixing other material problems. This paper also highlights advantages that this type of non-intrusive techniques offer over costly and monolithic traditional techniques.

  13. Sensor-based navigation of air duct inspection mobile robots

    Science.gov (United States)

    Koh, Kyoungchul; Choi, H. J.; Kim, Jae-Seon; Ko, Kuk Won; Cho, Hyungsuck

    2001-02-01

    12 This paper deals with an image sensor system and its position estimation algorithm for autonomous duct cleaning and inspection mobile robots. For the real application, a hierarchical control structure that consists of robot motion controller and image sensor system is designed considering the efficient and autonomous motion behaviors in narrow space such as air ducts. The sensor's system consists of a CCD camera and two laser sources to generate slit beams. The image of the structured lights is used for calculating the geometric parameters of the air ducts which are usually designed with a rectangular section. With the acquired 3D information about the environment, the mobile robot with two differential driving wheels is able to autonomously navigates along the duct path without any human intervention. For real time navigation, the relative position estimation of the robot are performed from 3D image reconstructed by the sensor system. The calibration and image processing methods used for the sensor system are presented with the experimental data. The experimental results show the possibility of the sensor based navigation which is important for effective duct cleaning by small mobile robots.

  14. Reliability Assessment and Reliability-Based Inspection and Maintenance of Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Ramírez, José G. Rangel; Sørensen, John Dalsgaard

    2009-01-01

    Probabilistic methodologies represent an important tool to identify the suitable strategy to inspect and deal with the deterioration in structures such as offshore wind turbines (OWT). Reliability based methods such as Risk Based Inspection (RBI) planning may represent a proper methodology...... to optimize inspection and maintenance (I&M) efforts, entailing to a suitable life-cycle performance without neglecting the economical aspect. Moreover, the integration of condition monitoring information (CMI) can be done through probabilistic inference. In this work, a reliability-based I&M planning OWT...... is presented where CMI may be incorporated. This framework is addressing to fatigue prone details in support structures for OWT. As part of the results, the life-cycle reliabilities and optimal inspection times are calculated. The influence on inspection times resulting from wind farm location of OWT and data...

  15. Toward a drone-based EL and PL inspection tool for PV power plants

    DEFF Research Database (Denmark)

    Riedel, Nicholas; Benatto, Gisele Alves dos Reis; Thorsteinsson, Sune

    On-site inspection of PV systems has been historically performed though visual inspection, infrared (IR) thermography, and electrical measurements.Recent advances and cost reductions in unmanned aerial vehicle (UAV)technology has led to adoption of UAVs equipped with thermal cameras for inspection...... of PV plants,which survey power plants in a fraction of the time and cost than walk through IR imaging. IR imaging however, is limited only to detection of certain fault types that result in elevated temperatures. Techniques such as electro-(EL) and photo-(PL) luminescence imaging offer a higher level...

  16. Toward a drone-based EL and PL inspection tool for PV power plants

    DEFF Research Database (Denmark)

    Riedel, Nicholas; Benatto, Gisele Alves dos Reis; Thorsteinsson, Sune

    2017-01-01

    On-site inspection of PV systems has been historically performed though visual inspection, infrared (IR) thermography, and electrical measurements.Recent advances and cost reductions in unmanned aerial vehicle (UAV)technology has led to adoption of UAVs equipped with thermal cameras for inspection...... of PV plants,which survey power plants in a fraction of the time and cost than walk through IR imaging. IR imaging however, is limited only to detection of certain fault types that result in elevated temperatures. Techniques such as electro-(EL) and photo-(PL) luminescence imaging offer a higher level...

  17. Robotized Inspection of Vertical Structures of a Solar Power Plant Using NDT Techniques

    Directory of Open Access Journals (Sweden)

    Torsten Felsch

    2015-03-01

    Full Text Available Concentrated solar power (CSP plants are expansive facilities that require substantial inspection and maintenance. A fully automated inspection robot increases the efficiency of maintenance work, reduces operating and maintenance costs, and improves safety and work conditions for service technicians. This paper describes a climbing robot that is capable of performing inspection and maintenance on vertical surfaces of solar power plants, e.g., the tubes of the receiver in a central tower CSP plant. Specifically, the service robot’s climbing mechanism is explained and the results of the nondestructive inspection methods are reviewed. The robot moves on the panels of the receiver in the tower and aligns the sensors correctly for inspection. The vertical movement of the climbing kinematics is synchronized with the movement of the tower’s crane. Various devices that detect surface defects and thickness losses inside the tube were integrated into the robot. Since the tubes are exposed to very high radiation, they need to be inspected regularly.

  18. A Novel Image Alignment Algorithm Based on Rotation-Discriminating Ring-Shifted Projection for Automatic Optical Inspection

    Directory of Open Access Journals (Sweden)

    Chin-Sheng Chen

    2016-05-01

    Full Text Available This paper proposes a novel image alignment algorithm based on rotation-discriminating ring-shifted projection for automatic optical inspection. This new algorithm not only identifies the location of the template image within an inspection image but also provides precise rotation information during the template-matching process by using a novel rotation estimation scheme, the so-called ring-shifted technique. We use a two stage framework with an image pyramid searching technique for realizing the proposed image alignment algorithm; in the first stage, the similarity based on hybrid projection transformation with the image pyramid searching technique is employed for quick selection and location of the candidates in the inspection image. In the second stage, the rotation angle of the object is estimated by a novel ring-shifted technique. The estimation is performed only for the most likely candidate which is the one having the highest similarity in the first stage. The experimental results show that the proposed method provides accurate estimation for template matching with arbitrary rotations and is applicable in various environmental conditions.

  19. RBI - Risk Based Inspection: new technologies and methods applied to inspections of FPSO (Floating Production, Storage and Offloading Vessel) hull; IBR - Inspecao Baseada em Risco: novas tecnologias e metodos aplicados as inspecoes de casco de FPSOs

    Energy Technology Data Exchange (ETDEWEB)

    Farias, Bruno de; Figueiredo, Eduardo; Luiz, Marcio [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Meurer, Gustavo; Duarte, Romulo; Oliveira, Thais; Krzonkalla, Viviane [ABS Consulting, Rio de Janeiro, RJ (Brazil)

    2008-07-01

    With the aging of the FPSO's, which are fundamental to the operation Offshore, better techniques and technologies must be applied to assess more accurately the actual efficiency and structural conditions of producing unit. With the emergence of new engineering techniques and equipment and methods of structural inspection, is now possible to use these new technologies to better manage risk and reliability of the structure of the FPSO, with that, the inspections and methods are more rational and efficient. The Risk-Based Inspection is the tool for monitoring operation of industrial plants with systemic use of technology in conjunction with risk analysis and reliability. His concept is applicable to various branches of industry. The companies began their implementation of oil by refineries. The group of ABS Consulting with PETROBRAS has been developing and implementing these new technologies in inspections of hulls of FPSO's. Applied successfully in the units of the Campos basin, these methods are used by the group of Risk-Based Inspection to improve the efficiency of all the steps involved with the structural integrity of the unit. (author)

  20. Application of Markovian technique to modeling influences of inspection on pipe rupture frequencies

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, K.N. [ERIN Engineering and Research, Inc., Carlsbad, CA (United States); Gosselin, S. [Electric Power Research Inst., Charlotte, NC (United States). System and Component Integrity

    1997-10-01

    This paper presents the development and application of new reliability models to estimate the frequencies of piping failures in nuclear power plants. These models are developed as part of an effort to implement risk informed in-service inspection (RISI) strategies for piping systems. The technical approach to RISI adopted by EPRI is to take advantage of insights from service experience from over 2,000 reactor years of commercial LWR piping systems. This experience includes documented evidence of more than 1,500 pipe failures including about 100 that were severe enough to be classified as ruptures with leak flows in excess of 50 gpm, with the remaining failures involving smaller leak rates. These insights include the observation that essentially all the leaks and ruptures that have occurred in this experience are the result of a well defined set of failure mechanisms, whose causative factors have been determined. There are ongoing efforts sponsored by EPRI to update the database through a review of the base documents, correction of inconsistencies, and expansion of the information to include more experience and a larger set of pipe conditions. The more recent but as yet unpublished database includes over 6,000 records of flaws, cracks, challenges, leaks and ruptures. 8 refs, 3 figs, 2 tabs.

  1. A CAD-based inspection planning strategy for video measuring instrument

    Institute of Scientific and Technical Information of China (English)

    LU Rong-sheng; SHI Yan-qiong; XIA Rui-xue; CHEN Lin

    2012-01-01

    A CAD-based inspection planning strategy for video measuring instrument is proposed to improve manufacturing effec- tiveness. The system consists of a video probe that enables itself to inspect a work piece based on a CAD model. The measurement software includes CAIP module and MDP module. The CAIP module is developed based on a CAD development platform whose kernel is the Open CASCADE. The entire system was tested, and relevant examples show that the system can accomplish automatic inspection planning task for common parts efficiently.

  2. Development of nondestructive evaluation techniques for DAM inspection. Progress report, January 1995 through August 1997

    Energy Technology Data Exchange (ETDEWEB)

    Brown, A. E.; Thomas, G.H.

    1997-09-04

    The Lawrence Livermore National Laboratory has concluded a two and a half year study on the development of an ultrasonic inspection system to inspect post stressed steel tendons on dams and flood gates. The inspection systems were part of a program for the California Department of Water Resources. The effort included the identification of the location and amount of corrosion damage to the tendons, identification of the cause of corrosion, and the technology for inhibiting corrosion. Several NDE methods for inspecting and quantifying damage to steel reinforced concrete water pipes were investigated and presented to the DWR for their consideration. The additional methods included Ground Penetrating RADAR, Electro- Potential Measurements, Infrared Technology, Pipe Inspection Crawlers (designed to travel inside pipelines and simultaneously report on the pipe condition as viewed by ultrasonic methods and video cameras from within the pipeline.) Reference to consultants hired by LLNL for similar on-site corrosion inspections were given to the DWR. The LLNL research into industries that have products to prevent corrosion resulted in the identification of an Innsbruck, Austria, company. This company claims to have products to permanently protect post- or pre-stressed tendons. The caveat is that the tendon protection system must be installed when the tendons are installed because no retrofit is available. Corrosion mitigation on the steel reinforcements surrounding the concrete was addressed through active and passive cathodic protection schemes. The combination of corrosion and erosion were addressed during consideration for the inspection of water-pump impeller-blades that are used in the three stage, million horsepower, pumping stations at Edmunston.

  3. Reducing uncertainty in wind turbine blade health inspection with image processing techniques

    Science.gov (United States)

    Zhang, Huiyi

    Structural health inspection has been widely applied in the operation of wind farms to find early cracks in wind turbine blades (WTBs). Increased numbers of turbines and expanded rotor diameters are driving up the workloads and safety risks for site employees. Therefore, it is important to automate the inspection process as well as minimize the uncertainties involved in routine blade health inspection. In addition, crack documentation and trending is vital to assess rotor blade and turbine reliability in the 20 year designed life span. A new crack recognition and classification algorithm is described that can support automated structural health inspection of the surface of large composite WTBs. The first part of the study investigated the feasibility of digital image processing in WTB health inspection and defined the capability of numerically detecting cracks as small as hairline thickness. The second part of the study identified and analyzed the uncertainty of the digital image processing method. A self-learning algorithm was proposed to recognize and classify cracks without comparing a blade image to a library of crack images. The last part of the research quantified the uncertainty in the field conditions and the image processing methods.

  4. In service inspection of pipes based on risk methods; Inspeccion en servicio de tuberias basada en metodos de riesgo

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza G, G.; Viais J, J.; Carmona C, M. [ININ, Centro Nuclear ' Dr. Nabor Carrillo Flores' , Carretera Mexico Toluca, S/N. La Marquesa, Ocoyoacac, Mexico, C. P. 52750 (Mexico)]. e-mail: gmg@nuclear.inin.mx

    2006-07-01

    The politics of the Nuclear Regulatory Commission (by its initials in English NRC) of the United States of America on the use of the Probabilistic Safety Analysis (PSA) in activities of nuclear regulation it foments the use of this analysis technique to improve the decisions making, to reduce the unnecessary work in maintenance aspects, inspection and tests and to improve the regulatory efficiency. The inspection programs in service (ISI by its initials in English) developed by the American Society of Mechanical Engineers (by its initials in English ASME) it has been the one primary mechanism to prove the mechanical equipment in plants of nuclear energy, these programs indeed have been carried out in plants of nuclear energy by more of two decades. Their purpose is to identify the conditions, such as indications of cracks that are precursory of flights and ruptures which violate the integrity principles of the pressure frontier. The inspection in service activities include ultrasonic tests, surface tests and penetrating liquids test, also activities that include the scaffolds construction, removal of insulations and welding polishing. The inspections in service every 18 months during the times outside of service are executed. One of the objectives is to lower the costs of the inspections during the times outside of service and to reduce the exposure to the radiation by part of the personnel during these times out for inspections, while it is increased or it maintains the personnel's safety and the reliability. As part of the methodology a pipe segment is selected for which a fault in any point has the same consequences, being calculated the fault probability of the tube using the dimensions of the segment. In this work the inspection in service methodology is applied based on risk to an aspersion system of low pressure of the Laguna Verde Nucleo electric Central. For this system a reduction in the number of welding to inspect of 103 to only 15 is obtained

  5. Electron Optic Design of Arrayed E-Beam Microcolumns Based Systems for Wafer Defects Inspection

    CERN Document Server

    Kazmiruk, V V

    2008-01-01

    In this paper is considered a matter of the system for wafer defect inspection (WDIS) practical realization. Such systems are on the agenda as the next generation and substitution for light optics and single $e$-beam based WDISs.

  6. Cost effectiveness and reliability improvement capabilities of CHECWORKS and SWIPS based inspection and maintenance plans

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S. [United Dynamics, Malvern, PA (United States); Borodotsky, A. [Rochester Gas and Electric Corp., NY (United States)

    1996-11-01

    CHECWORKS and SWIPS are computer programs that undertaken degradation analysis and generate prioritized lists for scheduling inspections. A simplified analysis presented in this paper demonstrates that application of such computer aided degeneration analysis and prioritized list based I and M plans can achieve full system reliability along with high cost effectiveness. For purposes of developing insight and a basic understanding, relative cost-effectiveness and system reliability improvement analysis is conducted on a small service water system for five types of inspection and maintenance plans. The following plans are considered: a full inspection plan, a random sampling plan, an experienced based sampling plan, a computer aided degeneration analysis based plan, and a superman based plan. The results obtained show that a computer aided inspection plan is the most effective of the feasible plans. For a realistic system, the plan can pay for the analysis cost and generate additional cost savings while maintaining full system reliability.

  7. In-Service Inspection of Wall-thinned Defects Using a Lock-in Technique of IR Thermography

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Kwae Hwan; Kim, Ju Hyun; Na, Man Gyun; Kim, Jin Weon [Chosun Univ., Gwangju (Korea, Republic of)

    2013-10-15

    In this study, a lock-in technique and power adjustment were applied to the cooling device for the IR thermography in order to detect the wall-thinned defects of the pipe specimen in a normal operation NPPs. According as the number of the cooling devices is increased and air volume transferred by the cooling device increases, wall-thinned defects inside pipes are more visible. By cooling the pipe using a lock-in technique in IR thermography, the boundary of the wall-thinned defective part is clear and the defect detection is easy. It is expected to detect the wall-thinned defects of piping during normal operation, to shorten the maintenance time of the NPPs, and to improve the work efficiency of the inspector. Recently, the safety problem of nuclear power plants (NPPs) has emerged as a global concern. As a result, the secondary system equipment in long-term aged NPPs has been growing interest. For these reasons, NDT for checking the integrity of the secondary system equipment is performed. The infrared (IR) thermography is one of the NDT. It is possible for us to solve the problems of the existing NDT. IR thermography can detect without contact the wall-thinned defects in pipes. Also, IR thermography using a lock-in technique for inspection is much safer and faster than other techniques. It is expected to be able to accurately detect the boundary of the non-defect parts and the defect parts, and shows a high utilization in the industrial field. Through this study, we have developed the inspection technique that can detect the defects by using the lock-in technique in IR thermography for inspection of pipes in the NPPs during the normal operation.

  8. Inspection technique of latent flaws on fine polished glass substrates using stress-induced light scattering method

    Science.gov (United States)

    Sakata, Yoshitaro; Sakai, Kazufumi; Nonaka, Kazuhiro

    2014-05-01

    The fine polishing technique, e.g. Chemical Mechanical Polishing treatment (CMP), is one of the most important techniques in the glass substrate manufacturing. However, mechanical interaction, e.g. friction, occurs between the abrasive and the surface of substrates. Therefore, latent flaws are formed in the surfaces of glass substrates depending on the polishing condition. In the case of the cleaning process of the glass substrate in which the latent flaws existed, latent flaws become obvious because glass surfaces were eaten away by chemical interaction of cleaning liquid. Therefore, latent flaws are the cause of decrease the yield of products. In general, non-destructive inspection techniques, e.g. light scattering method, foreign matter on the surface of glass substrates. Though, it is difficult to detect the latent flaws by these method, because these are closed. The present authors propose a novel inspection technique of latent flaws which occurred by the fine polishing technique, using light scattering method with stress concentration (Stress-Induced Light scattering Method; SILSM). SILSM is possible to classify and separately detect latent flaws and particles on the surfaces. Samples are deformed by the actuator and stress concentrations are occurred around the tip of latent flaws. By photo-elastic effect, the refractive index of around the tip of latent flaws is changed. And then, changed refractive index is detected by cooled CCD camera as the light scattering intensity. In this report, applying SILSM to glass substrates, latent flaws on the surface of glass substrates are detected non-destructively, and the usefulness of SILSM is evaluated as novel inspection technique of latent flaws.

  9. Risk Based Optimal Inspection and Repair Planning for Ship Structures Subjected to Corrosion Deterioration

    Institute of Scientific and Technical Information of China (English)

    李典庆; 张圣坤; 唐文勇

    2004-01-01

    A framework of risk based inspection and repair planning was presented to optimize for the ship structures subjected to corrosion deterioration. The planning problem was formulated as an optimization problem where the expected lifetime costs were minimized with a constraint on the minimum acceptable reliability index. The safety margins were established for the inspection events, the repair events and the failure events for ship structures. Moreover, the formulae were derived to calculate failure probabilities and repair probabilities. Based on them, a component subjected to corrosion is investigated for illustration of the process of selecting the optimal inspection and repair strategy. Furthermore, some sensitivity studies were provided. The results show that the optimal inspection instants should take place before the reliability index reaches the minimum acceptable reliability index. The optimal target failure probability is 10-3. In addition, a balance can be achieved between the risk cost and total expected inspection and repair costs by means of the risk-based optimal inspection and repair method, which is very effective in selecting the optimal inspection and repair strategy.

  10. Inspection of integrated circuits through the microfocus radiography technique; Inspecao de circuitos integrados atraves da tecnica radiografia microfocada

    Energy Technology Data Exchange (ETDEWEB)

    Scofano, Carmelo Fabio; Staszczak, Eduardo Jose; Rebello, Joao Marcos Alcoforado [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia

    1995-12-31

    The application of microfocus radiography technique for integrated circuits inspection is evaluated. The experiments were performed according to the international standards for micro-electronic components. In order to define the operational parameters, factors such as contrast and image definition were considered, and by varying the voltage and amperage applied to the X-ray apparatus it was tried to obtain radiographic images with an adequate resolution. the results show that this technique is a promising tool for evaluating these components. 17 refs., 16 figs., 2 tabs.

  11. A Novel Web-Based Approach for Visualization and Inspection of Reading Difficulties on University Students

    DEFF Research Database (Denmark)

    Mejia, Carolina; Florian-Gaviria, Beatriz; Vatrapu, Ravi

    2017-01-01

    Existing tools aim to detect university students with early diagnosis of dyslexia or reading difficulties, but there are not developed tools that let those students better understand some aspects regarding their difficulties. In this paper, a dashboard for visualizing and inspecting early detected...... reading difficulties and their characteristics, called PADA (acronym for the Spanish name Panel de Analíticas de Aprendizaje de Dislexia en Adultos), is presented. PADA is a web-based tool designed to facilitate the creation of descriptive visualizations required for a better understanding of students...... about their learner model. Through information visualization techniques, PADA shows students the knowledge in their learner models in order to help them to increase their awareness and to support reflection and self-regulation about their difficulties in reading. PADA provides different learning...

  12. Research on automatic inspection system for defects on precise optical surface based on machine vision

    Institute of Scientific and Technical Information of China (English)

    WANG Xue; XIE Zhi-jiang

    2006-01-01

    In manufacture of precise optical products, it is important to inspect and classify the potential defects existing on the products' surfaces after precise machining in order to obtain high quality in both functionality and aesthetics. The existing methods for detecting and classifying defects all are low accuracy or efficiency or high cost in inspection process. In this paper, a new inspection system based on machine vision has been introduced, which uses automatic focusing and image mosaic technologies to rapidly acquire distinct surface image, and employs Case-Based Reasoning(CBR)method in defects classification. A modificatory fuzzy similarity algorithm in CBR has been adopted for more quick and robust need of pattern recognition in practice inspection. Experiments show that the system can inspect surface diameter of 500mm in half an hour with resolving power of 0.8μm diameter according to digs or 0.5μm transverse width according to scratches. The proposed inspection principles and methods not only have meet manufacturing requirements of precise optical products, but also have great potential applications in other fields of precise surface inspection.

  13. [Hyperspectral acquisition system for tongue inspection based on X-Y scanning galvanometer].

    Science.gov (United States)

    Li, Gang; Zhao, Jing; Lin, Ling; Zhang, Bao-ju

    2011-12-01

    Hyperspectral was used for tongue inspection in the present work to resolve the problem that information of current research for tongue inspection was inadequate. A hyperspectral acquisition system based on X-Y scanning galvanometer was also proposed due to the high cost of the current hyperspectral apparatus. An experiment was made to test the ability of this system. By collecting the hyperspectral information of color pictures with size similar to the tongue, the results of experiment showed that this system can acquire more information of tongue than other methods, and this method can provide a new way for tongue inspection.

  14. State Inspection for Transmission Lines Based on Independent Component Analysis

    Institute of Scientific and Technical Information of China (English)

    REN Li-jia; JIANG Xiu-chen; SHENG Ge-hao; YANG Wei-wei

    2009-01-01

    Monitoring transmission towers is of great importance to prevent severe thefts on them and ensure the reliability and safety of the power grid operation. Independent component analysis (ICA) is a method for finding underlying factors or components from multivariate statistical data based on dimension reduction methods, and it is applicable to extract the non-stationary signals. FastICA based on negentropy is presented to effectively extract and separate the vibration signals caused by human activity in this paper. A new method combined empirical mode decomposition (EMD) technique with the adaptive threshold method is applied to extract the vibration pulses, and suppress the interference signals. The practical tests demonstrate that the method proposed in the paper is effective in separating and extracting the vibration signals.

  15. Cost Optimal Reliability Based Inspection and Replacement Planning of Piping Subjected to CO2 Corrosion

    DEFF Research Database (Denmark)

    Hellevik, S. G.; Langen, I.; Sørensen, John Dalsgaard

    1999-01-01

    A methodology for cost optimal reliability based inspection and replacement planning of piping subjected to CO2 corrosion is described. Both initial (design phase) and in-service planning are dealt with. The methodology is based on the application of methods for structural reliability analysis...... within the framework of Bayesian decision theory. The planning problem is formulated as an optimization problem where the expected lifetime costs are minimized with a constraint on the minimum acceptable reliability level. The optimization parameters are the number of inspections in the expected lifetime......, the inspection times and methods. In the design phase the nominal design wall thickness is also treated as an optimization parameter. The most important benefits gained through the application of the methodology are consistent evaluation of the consequences of different inspection and replacement plans...

  16. Design of inspection and maintenance models based on the CCC-chart

    OpenAIRE

    Chan, LY

    2003-01-01

    In this research, six maintenance models are constructed based on whether minor inspection, major inspection, minor maintenance and major maintenance are performed on a system. The system to study is a production process in which items produced can be classified as either conforming or nonconforming, and a statistical process control chart called CCC-chart (cumulative count control chart) can be applied to monitor the process. The maintenance models are analyzed quantitatively, and selection ...

  17. An artificial immune approach for optical image based vision inspection

    Institute of Scientific and Technical Information of China (English)

    Hong Zheng(郑宏); Nanfeng Xiao(肖南风); Jinhui Lan(蓝金辉)

    2003-01-01

    This paper presents a novel approach of visual inspection for texture surface defects. The approach usesartificial immune theory in learning the detection of texture defects. In this paper, texture defects areregards as non-self, and normal textures are regarded as self. Defect filters and segmentation thresholdsused for defect detection are regarded as antibodies. The clonal selection algorithm stemmed from thenatural immune system is employed to learn antibodies. Experimental results on textile image inspectionare presented to illustrate the merit and feasibility of the proposed method.

  18. A real-time surface inspection system for precision steel balls based on machine vision

    Science.gov (United States)

    Chen, Yi-Ji; Tsai, Jhy-Cherng; Hsu, Ya-Chen

    2016-07-01

    Precision steel balls are one of the most fundament components for motion and power transmission parts and they are widely used in industrial machinery and the automotive industry. As precision balls are crucial for the quality of these products, there is an urgent need to develop a fast and robust system for inspecting defects of precision steel balls. In this paper, a real-time system for inspecting surface defects of precision steel balls is developed based on machine vision. The developed system integrates a dual-lighting system, an unfolding mechanism and inspection algorithms for real-time signal processing and defect detection. The developed system is tested under feeding speeds of 4 pcs s-1 with a detection rate of 99.94% and an error rate of 0.10%. The minimum detectable surface flaw area is 0.01 mm2, which meets the requirement for inspecting ISO grade 100 precision steel balls.

  19. A Bevel Gear Quality Inspection System Based on Multi-Camera Vision Technology.

    Science.gov (United States)

    Liu, Ruiling; Zhong, Dexing; Lyu, Hongqiang; Han, Jiuqiang

    2016-08-25

    Surface defect detection and dimension measurement of automotive bevel gears by manual inspection are costly, inefficient, low speed and low accuracy. In order to solve these problems, a synthetic bevel gear quality inspection system based on multi-camera vision technology is developed. The system can detect surface defects and measure gear dimensions simultaneously. Three efficient algorithms named Neighborhood Average Difference (NAD), Circle Approximation Method (CAM) and Fast Rotation-Position (FRP) are proposed. The system can detect knock damage, cracks, scratches, dents, gibbosity or repeated cutting of the spline, etc. The smallest detectable defect is 0.4 mm × 0.4 mm and the precision of dimension measurement is about 40-50 μm. One inspection process takes no more than 1.3 s. Both precision and speed meet the requirements of real-time online inspection in bevel gear production.

  20. Wavelet Based Image Denoising Technique

    Directory of Open Access Journals (Sweden)

    Sachin D Ruikar

    2011-03-01

    Full Text Available This paper proposes different approaches of wavelet based image denoising methods. The search for efficient image denoising methods is still a valid challenge at the crossing of functional analysis and statistics. In spite of the sophistication of the recently proposed methods, most algorithms have not yet attained a desirable level of applicability. Wavelet algorithms are useful tool for signal processing such as image compression and denoising. Multi wavelets can be considered as an extension of scalar wavelets. The main aim is to modify the wavelet coefficients in the new basis, the noise can be removed from the data. In this paper, we extend the existing technique and providing a comprehensive evaluation of the proposed method. Results based on different noise, such as Gaussian, Poisson’s, Salt and Pepper, and Speckle performed in this paper. A signal to noise ratio as a measure of the quality of denoising was preferred.

  1. Robotized system for in-pipe inspection using pressure tolerant electronics technique

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Ramon R.; Hsu, Liu; Peixoto, Alessandro J.; Gomes, Luiz P.C.S. [Coordenacao dos Programas de Pos-graduacao de Engenharia (UFRJ/COPPE), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Eletrica. Grupo de Simulacao e Controle em Automacao e Robotica (GSCAR)]. E-mail: ramon, liu, jacoud, lpgomes@coep.ufrj.br; Reis, Ney R.S. dos [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas. Lab. de Robotica]. E-mail: salvireis@cenpes.petrobras.com.br

    2003-07-01

    This paper reports the development and experimental evaluation of a robotized system devised to perform two kinds of measurements inside a pipeline: the thickness of the internal wall painting layer and the internal radius. The thickness measurement allows the inspection of the painting layer quality and by measuring several radii it is possible to estimate the pipeline transversal section shape. The proposed scheme is shown to yield very satisfactory results on an actual 14'' (inches) pipeline in a real site. (author)

  2. Potential of Uav-Based Laser Scanner and Multispectral Camera Data in Building Inspection

    Science.gov (United States)

    Mader, D.; Blaskow, R.; Westfeld, P.; Weller, C.

    2016-06-01

    Conventional building inspection of bridges, dams or large constructions in general is rather time consuming and often cost expensive due to traffic closures and the need of special heavy vehicles such as under-bridge inspection units or other large lifting platforms. In consideration that, an unmanned aerial vehicle (UAV) will be more reliable and efficient as well as less expensive and simpler to operate. The utilisation of UAVs as an assisting tool in building inspections is obviously. Furthermore, light-weight special sensors such as infrared and thermal cameras as well as laser scanner are available and predestined for usage on unmanned aircraft systems. Such a flexible low-cost system is realized in the ADFEX project with the goal of time-efficient object exploration, monitoring and damage detection. For this purpose, a fleet of UAVs, equipped with several sensors for navigation, obstacle avoidance and 3D object-data acquisition, has been developed and constructed. This contribution deals with the potential of UAV-based data in building inspection. Therefore, an overview of the ADFEX project, sensor specifications and requirements of building inspections in general are given. On the basis of results achieved in practical studies, the applicability and potential of the UAV system in building inspection will be presented and discussed.

  3. Application of mobile GIS in special equipment inspection based on PDA

    Science.gov (United States)

    Chen, Zhirong; Xu, Caijiang

    2008-10-01

    This paper discusses how to apply the mobile GIS technology to the common special equipment inspection business to meet the requirements of efficient management. The concepts of "special equipment" and "mobile GIS" are introduced at beginning. Then we analyze the business background and the present technique research; put forward a mobile GIS solution apply to special equipment inspection. A Special Equipment Inspection System is designed independently. The system architecture and database structure are discussed in detail. In the mobile environment, three key technologies are especially discussed in the paper, such as the interface design adapt to PDA device, data alternate mechanism and other embedded development attentions. The system has been used in Hangzhou Bureau of Quality and Technical Supervision for special equipment management, and gotten good result. So the requirements of scientifically manage the special equipment and establish e-government are completed met.

  4. Development of nuclear fuel rod inspection technique using ultrasonic resonance phenomenon

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Myung Sun; Lee, Jong Po; Ju, Young Sang [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1995-11-01

    Acoustic resonance scattering from a nuclear fuel rod in water is analyzed. A new model for the background which is attributed to the interference of reflected wave and diffracted wave is found and here named {sup t}he inherent background{sup .} The resonance spectrum of a fuel rod is obtained by subtracting the inherent background from the scattered pressure. And also analyzed are the effect of material damping of cladding tube and pellet on the resonance spectrum of a fuel rod. The propagation characteristics of circumferential waves which cause the resonances of cladding tube is produced and the appropriate resonance modes for the application to the inspection of assembled fuel rods are selected. The resonance modes are experimentally measured for pre- and post-irradiated fuel rods and the validation of the fuel rod inspection using ultrasonic resonance phenomenon is examined. And thin ultrasonic sensors accessible into the narrow interval (about 2-3mm) between assembled fuel rods are designed and manufactured. 14 refs. (Author).

  5. GASVOL 18'' gas pipeline - risk based inspection study

    Energy Technology Data Exchange (ETDEWEB)

    Bjoernoey, Ola H.; Etterdal, Birger A. [Det Norske Veritas (DNV), Oslo (Norway); Guarize, Rosimar; Oliveira, Luiz F.S. [Det Norske Veritas (DNV) (Brazil); Faertes, Denise; Dias, Ricardo [TRANSPETRO - PETROBRAS Transporte S.A., Rio de Janeiro, RJ (Brazil)

    2003-07-01

    This paper describes a risk based approach and inspection planning as part of the Pipeline Integrity Management (PIM) system for the 95.5 km long 18'' GASVOL gas pipeline in the South eastern region of Brazil transporting circa 5 000 000 m3 dry gas per day. Pipeline systems can be subject to several degradation mechanisms and inspection and monitoring are used to ensure system integrity. Modern pipeline regulations and codes are normally based on a core safety or risk philosophy. The detailed design requirements presented in design codes are practical interpretations established so as to fulfill these core objectives. A given pipeline, designed, constructed and installed according to a pipeline code is therefore the realization of a structure, which, along its whole length, meets the applicable safety objectives of that code. The main objective of Pipeline Integrity Management (PIM) is to control and document the integrity of the pipeline for its whole service life, and to do this in a cost-effective manner. DNV has a specific approach to RBI planning, starting with an initial qualitative assessment where pipelines and damage type are ranked according to risk and potential risk reduction by an inspection and then carried forward to a quantitative detailed assessment where the level of complexity and accuracy can vary based on availability of information and owner needs. Detailed assessment requires significant effort in data gathering. The findings are dependent upon the accuracy of the inspection data, and on DNV's interpretation of the pipeline reference system and simplifications in the inspection data reported. The following specific failure mechanisms were investigated: internal corrosion, external corrosion, third party interference, landslides and black powder. RBI planning, in general words, is a 'living process'. In order to optimize future inspections, it is essential that the analyses utilize the most recent information regarding

  6. Inspection of calandria front area of Wolsung NPP using technique of mapping thermal infrared image into CCD image

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Jai Wan; Kim, Chang Hoi; Seo, Yong Chil; Choi, Young Soo; Kim, Seung Ho [Advance Robotics Teams, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2002-11-15

    This paper describes the enhanced inspection performance of a thermal infrared camera for monitoring abnormal conditions of calandria reactor area of Wolsung nuclear power plant. Thermal infrared camera have poor image qualities compared to commercial CCD cameras, as in contrast, brightness, and resolution. To compensate the poor image quality problems associated with the thermal infrared camera, the technique of mapping thermal infrared image into real ccd image is proposed. The mobile robot KAEROT/m2, loaded with sensor head system at the mast, is entered to monitor leakage of heavy water and thermal abnormality of the calandria reactor area in overhaul period. The sensor head system is composed of thermal infrared camera and ccd camera in parallel. When thermal abnormality on observation points and areas of calandria reactor area is occurred, unusual hot image taken from thermal infrared camera is superimposed on real CCD image. In this inspection experiment, more accurate positions of thermal abnormalities on calandria reactor area can be estimated by using technique of mapping thermal infrared image into CCD image, which include characters arranged in MPOQ order.

  7. Defect inspection and printability study for 14 nm node and beyond photomask

    Science.gov (United States)

    Seki, Kazunori; Yonetani, Masashi; Badger, Karen; Dechene, Dan J.; Akima, Shinji

    2016-10-01

    Two different mask inspection techniques are developed and compared for 14 nm node and beyond photomasks, High resolution and Litho-based inspection. High resolution inspection is the general inspection method in which a 19x nm wavelength laser is used with the High NA inspection optics. Litho-based inspection is a new inspection technology. This inspection uses the wafer lithography information, and as such, this method has automatic defect classification capability which is based on wafer printability. Both High resolution and Litho-based inspection methods are compared using 14 nm and 7 nm node programmed defect and production design masks. The defect sensitivity and mask inspectability is compared, in addition to comparing the defect classification and throughput. Additionally, the Cost / Infrastructure comparison is analyzed and the impact of each inspection method is discussed.

  8. Automatic Inspection of the Warp-Weft Density Using Image Processing Techniques

    OpenAIRE

    ALDEMİR, Erdoğan; Hakan ÖZDEMİR; KILINÇ, Selçuk

    2016-01-01

    In this study, possibility of determining warp and weft yarn density of colored and figured plain and twill woven fabrics by Wiener filter, median filter, grey level co-occurrence matrix and gray line profile methods, which are spatial techniques, and by Fourier and wavelet transformation methods, which are frequency domain techniques, are investigated. Considering the spatial techniques, the most successful technique that determines warp and weft densities of plain and twill fabrics is the m...

  9. Epidemiologic and economic evaluation of risk-based meat inspection for bovine cysticercosis in Danish cattle.

    Science.gov (United States)

    Calvo-Artavia, F F; Nielsen, L R; Alban, L

    2013-03-01

    Under the current EU meat inspection regulation, every single carcase from all bovines above 6 weeks of age has to be examined for bovine cysticercosis (BC). This is time-consuming, costly, and is of limited value in countries with low prevalence. The aim of this study was to develop a stochastic simulation model for analysis of tentative risk-based meat inspection systems for BC in Danish cattle with regard to system sensitivity (SSSe), specificity and potential monetary benefits compared to the current system, which has an estimated SSSe of 15%. The relevant risk factors used to construct three alternative scenario trees were identified from previous Danish risk factor studies (1) gender, (2) grazing and (3) access to risky water sources. Thus, females, animals that had been grazing or animals with access to risky water sources were considered high-risk and would be subjected to invasive inspection at meat inspection. All animals in the low-risk groups (i.e. males, non-grazing or no access to risky water sources, respectively) would be subjected to visual inspection only. It was assumed that half of the cattle were slaughtered in abattoirs that would be able to reorganise the work at the slaughterline, allowing them to do with one meat inspector less. All abattoirs would gain on the price of sold uncut beef from the masseter muscles from visually inspected cattle. Under these assumptions, using gender and grazing were preferable due to them having SSSe only slightly lower than the current system, and highest effectiveness ratios, but they had a lower net economic effect (NEE) than the scenario using risky water sources. Using gender to differentiate high and low-risk groups was judged preferable over grazing due to feasibility, because the information is readily available at the slaughter line. The exact total NEE for the cattle sector depends on how many and which of the abattoirs that would be able to reorganise the work at the slaughter line to save money on

  10. Two non-destructive neutron inspection techniques: prompt gamma-ray activation analysis and cold neutron tomography

    OpenAIRE

    Baechler, Sébastien; Dousse, Jean-Claude; Jolie, Jan

    2005-01-01

    Deux techniques d’inspection non-destructives utilisant des faisceaux de neutrons froids ont été développées à la source de neutrons SINQ de l’Institut Paul Scherrer : (1) l’analyse par activation neutronique prompte (PGAA) et (2) la tomographie neutronique. L’analyse par PGA (Prompt Gamma-ray Activation) est une méthode nucléaire qui permet de déterminer la concentration d’éléments présents dans un échantillon. Cette technique consiste à détecter les rayons gamma prompts émis par l’échantill...

  11. Reliability of non-destructive test techniques in the inspection of pipelines used in the oil industry

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, A.A. [Science Technological Center, University of Fortaleza, UNIFOR, Av. Washington Soares, 1321, Edson Queiroz, CEP: 60, 811-905 Fortaleza-CE (Brazil)], E-mail: alves@metalmat.ufrj.br; Rebello, J.M.A.; Souza, M.P.V. [Federal University of Rio de Janeiro, CEP: 21941-972, Rio de Janeiro, RJ (Brazil); Sagrilo, L.V.S. [Department of Civil Engineering, COPPE/UFRJ, Federal University of Rio de Janeiro, Rio de Janeiro (Brazil); Soares, S.D. [Cidade Universitaria, Ilha do Fundao, CEP: 21949-900, Rio de Janeiro, RJ (Brazil)

    2008-11-15

    The aim of this work is to evaluate the reliability of non-destructive test (NDT) techniques for the inspection of pipeline welds employed in the petroleum industry. Radiography, manual and automatic ultrasonic techniques using pulse-echo and time of flight diffraction (TOFD) were employed. Three classes of defects were analyzed: lack of penetration (LP), lack of fusion (LF) and undercut (UC). The tests were carried out on specimen made from pipelines containing defects, which had been artificially inserted on laying the weld bead. The results showed the superiority of the automatic ultrasonic tests for defect detection compared with the manual ultrasonic and radiographic tests. Additionally, artificial neural networks (ANN) were used in the detection and automatic classification of the defects.

  12. Risk-Based Inspection and Maintenance Planning Optimization of Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Ramírez, José G. Rangel; Sørensen, John Dalsgaard

    2009-01-01

    A risk-based inspection planning (RBI) approach applied to offshore wind turbines (OWT) is presented, based on RBI methodology developed in the last decades in the oil and gas industry. In wind farm (IWF) and single-alone locations are considered using a code-established turbulence models including...

  13. A New Tool for Collaborative Video Search via Content-based Retrieval and Visual Inspection

    NARCIS (Netherlands)

    Hürst, W.O.; Ip Vai Ching, Algernon; Hudelist, Marco A.; Primus, Manfred J.; Schoeffmann, Klaus; Beecks, Chrisitan

    2016-01-01

    We present a new approach for collaborative video search and video browsing relying on a combination of traditional, indexbased video retrieval complemented with large-scale human-based visual inspection. In particular, a traditional PC interface is used for query-based search using advanced indexin

  14. Generative inspection process planner for integrated production

    Energy Technology Data Exchange (ETDEWEB)

    Brown, C.W. (Allied-Signal Aerospace Co., Kansas City, MO (USA). Kansas City Div.); Gyorog, D.A. (Kansas Univ., Lawrence, KS (USA). Dept. of Mechanical Engineering)

    1990-04-01

    This work describes the design prototype development of a generative process planning system for dimensional inspection. The system, IPPEX (Inspection Process Planning EXpert), is a rule-based expert system for integrated production. Using as advanced product modeler, relational databases, and artificial intelligence techniques, IPPEX generates the process plan and part program for the dimensional inspection of products using CMMs. Through an application interface, the IPPEX system software accesses product definition from the product modeler. The modeler is a solid geometric modeler coupled with a dimension and tolerance modeler. Resource data regarding the machines, probes, and fixtures are queried from databases. IPPEX represents inspection process knowledge as production rules and incorporates an embedded inference engine to perform decision making. The IPPEX system, its functional architecture, system architecture, system approach, product modeling environment, inspection features, inspection knowledge, hierarchical planning strategy, user interface formats, and other fundamental issues related to inspection planning and part programming for CMMs are described. 27 refs., 16 figs., 4 tabs.

  15. Recognition algorithm of seabed pipeline defect inspection based on dynamic WBF neural networks

    Institute of Scientific and Technical Information of China (English)

    Jin Tao; Que Peiwen; Tao Zhengshu

    2005-01-01

    This paper describes a magnetic flux leak (MFL) model of pipeline defect inspection, and presents a recognition algorithm based on dynamic wavelet basis function (WBF) neural network. The dynamic network utilizes multiscale and multiresolution orthogonal wavelet, through signals backwards propagation, has more significant advantages than BP or other neural networks used in MFL inspection. It also can control the accuracy of the predicted defect profiles, high-speed convergence possessing and well approaching feature. The performance applying the algorithm based on the network to predict defect profile from experimental MFL signals is presented.

  16. An Empirical Comparative Study of Checklist based and Ad Hoc Code Reading Techniques in a Distributed Groupware Environment

    CERN Document Server

    Akinola, Olalekan S

    2009-01-01

    Software inspection is a necessary and important tool for software quality assurance. Since it was introduced by Fagan at IBM in 1976, arguments exist as to which method should be adopted to carry out the exercise, whether it should be paper based or tool based, and what reading technique should be used on the inspection document. Extensive works have been done to determine the effectiveness of reviewers in paper based environment when using ad hoc and checklist reading techniques. In this work, we take the software inspection research further by examining whether there is going to be any significant difference in defect detection effectiveness of reviewers when they use either ad hoc or checklist reading techniques in a distributed groupware environment. Twenty final year undergraduate students of computer science, divided into ad hoc and checklist reviewers groups of ten members each were employed to inspect a medium sized java code synchronously on groupware deployed on the Internet. The data obtained were...

  17. Application of wavelet packet entropy flow manifold learning in bearing factory inspection using the ultrasonic technique.

    Science.gov (United States)

    Chen, Xiaoguang; Liu, Dan; Xu, Guanghua; Jiang, Kuosheng; Liang, Lin

    2014-12-26

    For decades, bearing factory quality evaluation has been a key problem and the methods used are always static tests. This paper investigates the use of piezoelectric ultrasonic transducers (PUT) as dynamic diagnostic tools and a relevant signal classification technique, wavelet packet entropy (WPEntropy) flow manifold learning, for the evaluation of bearing factory quality. The data were analyzed using wavelet packet entropy (WPEntropy) flow manifold learning. The results showed that the ultrasonic technique with WPEntropy flow manifold learning was able to detect different types of defects on the bearing components. The test method and the proposed technique are described and the different signals are analyzed and discussed.

  18. Automated signal processing applied to volatile-based inspection of greenhouse crops

    NARCIS (Netherlands)

    Jansen, R.M.C.; Hofstee, J.W.; Bouwmeester, H.J.; Henten, van E.J.

    2010-01-01

    Gas chromatograph–mass spectrometers (GC-MS) have been used and shown utility for volatile-based inspection of greenhouse crops. However, a widely recognized difficulty associated with GC-MS application is the large and complex data generated by this instrument. As a consequence, experienced analyst

  19. GIS-based automated management of highway surface crack inspection system

    Science.gov (United States)

    Chung, Hung-Chi; Shinozuka, Masanobu; Soeller, Tony; Girardello, Roberto

    2004-07-01

    An automated in-situ road surface distress surveying and management system, AMPIS, has been developed on the basis of video images within the framework of GIS software. Video image processing techniques are introduced to acquire, process and analyze the road surface images obtained from a moving vehicle. ArcGIS platform is used to integrate the routines of image processing and spatial analysis in handling the full-scale metropolitan highway surface distress detection and data fusion/management. This makes it possible to present user-friendly interfaces in GIS and to provide efficient visualizations of surveyed results not only for the use of transportation engineers to manage road surveying documentations, data acquisition, analysis and management, but also for financial officials to plan maintenance and repair programs and further evaluate the socio-economic impacts of highway degradation and deterioration. A review performed in this study on fundamental principle of Pavement Management System (PMS) and its implementation indicates that the proposed approach of using GIS concept and its tools for PMS application will reshape PMS into a new information technology-based system that can provide convenient and efficient pavement inspection and management.

  20. BONDING OF MINIATURE PARTS WITH ADHESIVES AND VISION BASED PROCEDURE INSPECTION

    Institute of Scientific and Technical Information of China (English)

    Wang Xiaodong; Jürgen Hesselbach

    2004-01-01

    Bonding with adhesives is an important technique for building up hybrid microsystems.Some adhesives are tested with capillary dispensing system for microassembly,and volume of droplets less than 10 nl with good repeatability can be acquired.1-part UV curing adhesive hardens rapidly and is suitable for bonding of transparent microparts.Light-activated adhesive starts the curing process in an adjustable short period of time after the radiation of visible light,and thus suits bonding of non-transparent microparts.A method is proposed for bonding the guides of a miniature linear motor being developed by collaborate research center 516 (SFB516) in Germany.With the method high assembly accuracy in the vertical direction can be guaranteed.By making small grooves on the stator for containing adhesive,the deterioration of the accuracy due to the thickness of adhesive layer can be avoided.The criteria on deciding the size of the groove are given and analyzed.Vision based inspection method is introduced for automatic assembly of the guides.The dispensing volume and position of dispensed adhesive droplets can be detected for ensuring the bonding quality.

  1. Computational defect review for actinic mask inspections

    Science.gov (United States)

    Morgan, Paul; Rost, Daniel; Price, Daniel; Corcoran, Noel; Satake, Masaki; Hu, Peter; Peng, Danping; Yonenaga, Dean; Tolani, Vikram

    2013-04-01

    As optical lithography continues to extend into low-k1 regime, resolution of mask patterns continues to diminish. The limitation of 1.35 NA posed by water-based lithography has led to the application of various resolution enhancement techniques (RET), for example, use of strong phase-shifting masks, aggressive OPC and sub-resolution assist features, customized illuminators, etc. The adoption of these RET techniques combined with the requirements to detect even smaller defects on masks due to increasing MEEF, poses considerable challenges for a mask inspection engineer. Inspecting masks under their actinic-aerial image conditions would detect defects that are more likely to print under those exposure conditions. However, this also makes reviewing such defects in their low-contrast aerial images very challenging. On the other hand, inspecting masks under higher resolution inspection optics would allow for better viewing of defects post-inspection. However, such inspections generally would also detect many more defects, including printable and nuisance, thereby making it difficult to judge which are of real concern for printability on wafer. Often, an inspection engineer may choose to use Aerial and/or high resolution inspection modes depending on where in the process flow the mask is and the specific device-layer characteristics of the mask. Hence, a comprehensive approach is needed in handling defects both post-aerial and post-high resolution inspections. This analysis system is designed for the Applied Materials Aera™ mask inspection platform, all data reported was collected using the Aera.

  2. 基于3D虚拟现实技术的风电场全数字化巡检及监测平台%Full digital inspection and monitoring platform for wind farm based on 3D virtual reality technique

    Institute of Scientific and Technical Information of China (English)

    任岩; 闫素英; 万元; 胡边; 龚传利

    2016-01-01

    提出了基于3D虚拟现实技术的风电场全数字化巡检及监测平台的构建方案.该方案利用虚拟现实技术,对风电场全部设备进行3D数字化建模;应用远程通信技术,将风电场运行的状态数据、指标参数引入到巡检与监测平台.在此基础上,设计了系统的硬件结构,构建了信息的有效性检测模型,并建立风电机组的故障失效模式、影响及后果分析模型;结合状态数据、指标参数与分析模型,实现风电场设备故障诊断;同时,将诊断结果提示给工作人员,确保在中控室便能实现风电场的巡检、监测与故障诊断.%The wind farm has the characteristics of multiple units and scattered equipment distribution,which makes that the regular inspection and monitoring of the workload very large and there is a risk of falling from the sky.Therefore,a scheme of building wind farms inspection and monitoring platform based on 3D virtual reality technology is presented in this paper,which makes use of the virtual reality technology to build 3D digital modeling of all equipment in wind farm and applies the remote communication technology to collect the operation state data and the index parameter of the wind farm.Based on all above,the hardware structure of the platform is designed,the information validity detection model is constructed,and the fault failure mode,effect and consequence analysis model of wind turbine is established.By combining operation state data,index parameters and analysis model,the equipment fault diagnosis of the wind farm can be realized,and the diagnosis results can be provided to the staff,all of which makes sure that the inspection,monitoring and fault diagnosis of the wind farm can be finished in the central control room.

  3. POD generator project: a numerical assessment of the inspection of fatigue cracks using TOFD

    NARCIS (Netherlands)

    Bloom, J.G.P.; Stelwagen, U.; Mast, A.; Volker, A.W.F.

    2009-01-01

    Risk based inspection strategies rely on detailed knowledge of the performance of inspection techniques. The objective of the "POD generator" project is to develop a numerical modeling approach to assess the effectiveness of specific inspection techniques. Simulation offers flexibility and reliabili

  4. Development of advanced techniques for life management and inspection of advanced heavy water reactor (AWHR) coolant channel components

    Energy Technology Data Exchange (ETDEWEB)

    Madhusoodanan, K.; Sinha, S.K.; Kumar, K.; Shyam, T.V.; Panwar, S.; Sharma, B.S.V.G. [Bhabha Atomic Research Centre, Reactor Engineering Div., Trombay, Mumbai (India); Sinha, R. K. [Bhabha Atomic Research Centre, Reactor Design and Development Group., Trombay, Mumbai (India)

    2011-07-01

    Operating life of pressure tubes of Pressurized Heavy Water Reactor (PHWR) is limited due to the presence of various issues associated with the material like hydrogen pick up, delayed hydride cracking, axial elongation and increase in diameter due to irradiation creep and growth. Periodic monitoring of the health of the pressure tube under in-situ conditions is essential to ensure the safe operation of the reactor. New designs of reactor call for innovative design philosophy, modification in fabrication route of pressure tube, development of reactor specific tools, both analytical and hardware for assessing the fitness for service of the pressure tube. Feedback from existing reactors has enhanced the understanding about life limiting parameters. This paper gives an insight into the life limiting issues associated with pressure tube and the efforts pursued for development of life management techniques for coolant channel of Advanced Heavy Water Reactor (AHWR) designed in India. The tools and techniques for in-situ property/hydrogen measurement, pulsed eddy current technique for zirconium alloy in-homogeneity characterization, horizontal shear wave EMAT system for dissimilar metal weld inspection, sliver sampling of vertical channel etc. are elaborated in the paper. (author)

  5. A new track inspection car based on a laser camera system

    Institute of Scientific and Technical Information of China (English)

    Shengwei Ren; Shiping Gu; Guiyang Xu; Zhan Gao; Qibo Feng

    2011-01-01

    @@ We develop and build a new type of inspection car.A beam that is not rigidly connected to the train axle boxes and can absorb the vibration and impact caused by the high speed train is used, and a laser-camera measurement system based on the machine vision method is adopted.This method projects structural light onto the track and measures gauge and longitudinal irregularity.The measurement principle and model are discussed.Through numerous practical experiments, the rebuilt car is found to considerably eliminate the measurement errors caused by vibration and impact, thereby increasing measurement stability under high speeds.This new kind of inspection cars have been used in several Chinese administration bureaus.%We develop and build a new type of inspection car. A beam that is not rigidly connected to the train axle boxes and can absorb the vibration and impact caused by the high speed train is used, and a laser-camera measurement system based on the machine vision method is adopted. This method projects structural light onto the track and measures gauge and longitudinal irregularity. The measurement principle and model are discussed. Through numerous practical experiments, the rebuilt car is found to considerably eliminate the measurement errors caused by vibration and impact, thereby increasing measurement stability under high speeds. This new kind of inspection cars have been used in several Chinese administration bureaus.

  6. Automatic classification and defect verification based on inspection technology with lithography simulation

    Science.gov (United States)

    Kato, Masaya; Inuzuka, Hideki; Kosuge, Takeshi; Yoshikawa, Shingo; Kanno, Kayoko; Imai, Hidemichi; Miyashita, Hiroyuki; Vacca, Anthony; Fiekowsky, Peter; Fiekowsky, Dan

    2015-10-01

    Even small defects on the main patterns can create killer defects on the wafer, whereas the same defect on or near the decorative patterns may be completely benign to the wafer functionality. This ambiguity often causes operators and engineers to put a mask "on hold" to be analyzed by an AIMS™ tool which slows the manufacturing time and increases mask cost. In order to streamline the process, mask shops need a reliable way to quickly identify the wafer impact of defects during mask inspection review reducing the number of defects requiring AIMS™ analysis. Source Mask Optimization (SMO) techniques are now common on sub 20nm node critical reticle patterns These techniques create complex reticle patterns which often makes it difficult for inspection tool operators to identify the desired wafer pattern from the surrounding nonprinting patterns in advanced masks such as SMO, Inverse Lithography Technology (ILT), Negative Tone Development (NTD). In this study, we have tested a system that generates aerial simulation images directly from the inspection tool images. The resulting defect dispositions from a program defect test mask along with numerous production mask defects have been compared to the dispositions attained from AIMS™ analysis. The results of our comparisons are presented, as well as the impact to mask shop productivity.

  7. Nontraditional manufacturing technique-Nano machining technique based on SPM

    Institute of Scientific and Technical Information of China (English)

    DONG; Shen; YAN; Yongda; SUN; Tao; LIANG; Yingchun; CHENG

    2004-01-01

    Nano machining based on SPM is a novel, nontraditional advanced manufacturing technique. There are three main machining methods based on SPM, i.e.single atom manipulation, surface modification using physical or chemical actions and mechanical scratching. The current development of this technique is summarized. Based on the analysis of mechanical scratching mechanism, a 5 μm micro inflation hole is fabricated on the surface of inertial confinement fusion (ICF) target. The processing technique is optimized. The machining properties of brittle material, single crystal Ge, are investigated. A micro machining system combining SPM and a high accuracy stage is developed. Some 2D and 3D microstructures are fabricated using the system. This method has broad applications in the field of nano machining.

  8. ILT based defect simulation of inspection images accurately predicts mask defect printability on wafer

    Science.gov (United States)

    Deep, Prakash; Paninjath, Sankaranarayanan; Pereira, Mark; Buck, Peter

    2016-05-01

    At advanced technology nodes mask complexity has been increased because of large-scale use of resolution enhancement technologies (RET) which includes Optical Proximity Correction (OPC), Inverse Lithography Technology (ILT) and Source Mask Optimization (SMO). The number of defects detected during inspection of such mask increased drastically and differentiation of critical and non-critical defects are more challenging, complex and time consuming. Because of significant defectivity of EUVL masks and non-availability of actinic inspection, it is important and also challenging to predict the criticality of defects for printability on wafer. This is one of the significant barriers for the adoption of EUVL for semiconductor manufacturing. Techniques to decide criticality of defects from images captured using non actinic inspection images is desired till actinic inspection is not available. High resolution inspection of photomask images detects many defects which are used for process and mask qualification. Repairing all defects is not practical and probably not required, however it's imperative to know which defects are severe enough to impact wafer before repair. Additionally, wafer printability check is always desired after repairing a defect. AIMSTM review is the industry standard for this, however doing AIMSTM review for all defects is expensive and very time consuming. Fast, accurate and an economical mechanism is desired which can predict defect printability on wafer accurately and quickly from images captured using high resolution inspection machine. Predicting defect printability from such images is challenging due to the fact that the high resolution images do not correlate with actual mask contours. The challenge is increased due to use of different optical condition during inspection other than actual scanner condition, and defects found in such images do not have correlation with actual impact on wafer. Our automated defect simulation tool predicts

  9. Presence and numbers of Campylobacter, Escherichia coli and Salmonella determined in boiler carcass rinses from United States processing plants in the hazard analysis and critical control point-based inspection models project

    Science.gov (United States)

    In 1999, the USDA-Food Safety Inspection Service introduced an inspection system called The HACCP-Based Inspection Models Project (HIMP). HIMP varies from traditional inspection in that more emphasis is placed on system inspection and verification. Each carcass is still visually inspected but some...

  10. Multiclass MTS for saxophone timbre quality inspection using waveform-shape-based features.

    Science.gov (United States)

    Hsiao, Yu-Hsiang; Su, Chao-Ton

    2009-06-01

    Under the highly developed automation today, the manufacture of saxophone is still a nonautomatic process and much relies on highly skilled technicians. In order to insure the timbre quality, the sound of finished saxophone must be tested in the final inspection stage. The evaluation of timbre quality mainly depends on the professional musicians' hearing judgment; however, the sensitivity of human perception can be influenced by many factors. To improve the reliability of saxophone timbre quality inspection, an automatic multiclass timbre classification system (AMTCS) is developed and used to assist in the inspection work. The AMTCS is composed of our proposed waveform-shape-based feature extraction method in parameterization phase and multiclass Mahalanobis-Taguchi system in classification phase. The numerical experiments show that the musical instrument classification accuracy obtained by our proposed AMTCS is satisfactory. Through employing the AMTCS, strong assistance was provided to the inspection of saxophone timbre quality, and a perfect identification rate on the saxophones with different timbre quality levels is achieved. Moreover, the significant tones having impact on saxophone timbre quality can also be easily identified by AMTCS.

  11. Reliability-Based Planning of Inspection, Operation and Maintenance for Offshore Oil & Gas Structures and Wind Turbines

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    2011-01-01

    Reliability-based cost-optimal planning of inspection, maintenance and operation has many applications. In this paper applications for planning of inspections for oil & gas jacket structures and of operation and maintenance of offshore wind turbines are described and illustrated by examples....

  12. Reactive underwater object inspection based on artificial electric sense.

    Science.gov (United States)

    Lebastard, Vincent; Boyer, Frédéric; Lanneau, Sylvain

    2016-07-26

    Weakly electric fish can perform complex cognitive tasks based on extracting information from blurry electric images projected from their immediate environment onto their electro-sensitive skin. In particular they can be trained to recognize the intrinsic properties of objects such as their shape, size and electric nature. They do this by means of novel perceptual strategies that exploit the relations between the physics of a self-generated electric field, their body morphology and the ability to perform specific movement termed probing motor acts (PMAs). In this article we artificially reproduce and combine these PMAs to build an autonomous control strategy that allows an artificial electric sensor to find electrically contrasted objects, and to orbit around them based on a minimum set of measurements and simple reactive feedback control laws of the probe's motion. The approach does not require any simulation models and could be implemented on an autonomous underwater vehicle (AUV) equipped with artificial electric sense. The AUV has only to satisfy certain simple geometric properties, such as bi-laterally (left/right) symmetrical electrodes and possess a reasonably high aspect (length/width) ratio.

  13. Development of ultrasonic testing DSP inspection technique for class 1 system piping in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Ku, Kil Mo; Lee, Ik Whan; Jeong, Hyun Kyu; Park, Moon Ho; Heo, Hyung; Kong, Un Sik [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1996-01-01

    The purpose of this study is to explore the utilization of new constant-Q SSP in ultrasonic NDE. Various engineering problems are reviewed, and suggestions for implementation of the technique are provided. The filters of new Constant-Q SSP centered on frequency points, and normalized type of the filtered signals was not nromalized. The new Constant-Q SSP uses the frequency-dependant response of the interfering coherent noise produced by unresolvable scatters in the resolution range cell of a transducer. It is implemented by splitting the frequency spectrum of the received signal with gaussian bandpass filters. The principles of the SSP and the various optimization algorithms are recalled, and the conventional decomposition method for the SSP was presented.

  14. Development of nuclear fuel rod inspection technique using ultrasonic resonance phenomenon

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Myoung Seon; Joo, Young Sang; Jung, Hyun Kyu; Cheong, Yong Moo

    1997-02-01

    The scattering of plane acoustic waves normally incident on a multilayered cylindrical shell has been formulated using the global matrix approach. And a simple way to formulate the non-resonant background component in the field scattered by an empty elastic shell has been found. This is to replace the surface admittance for the shell with the zero-frequency limit of the surface admittance for the analogous fluid shell (i.e., the shear wave speed in the elastic shell is set to zero). It has been shown that the background thus obtained is exact and applicable to shells of arbitrary thickness and material makeup, and over all frequencies and mode numbers. This way has been also applied to obtain the expressions of the backgrounds for multilayered shells. The resonant ultrasound spectroscopy system has been constructed to measure the resonance spectrum of a single fuel rod. The leak-defective fuel rod detection system of a laboratory scale has been also constructed. Particularly, all techniques and processes necessary for manufacturing the ultrasonic probe of thin (1.2 mm) strip type have been developed. (author). 38 refs., 34 figs.

  15. The SAFT-UT (synthetic aperture focusing technique for ultrasonic testing) real-time inspection system: Operational principles and implementation

    Energy Technology Data Exchange (ETDEWEB)

    Hall, T. E.; Reid, L. D.; Doctor, S. R.

    1988-06-01

    This document provides a technical description of the real-time imaging system developed for rapid flaw detection and characterization utilizing the synthetic aperture focusing technique for ultrasonic testing (SAFT-UT). The complete fieldable system has been designed to perform inservice inspection of light-water reactor components. Software was written on a DEC LSI 11/23 computer system to control data collection. The unprocessed data is transferred to a VAX 11/730 host computer to perform data processing and image display tasks. A parallel architecture peripheral to the host computer, referred to as the Real-Time SAFT Processor, rapidly performs the SAFT processing function. From the host's point of view, this device operates on the SAFT data in such a way that one may consider it to be a specialized or SAFT array processor. A guide to SAFT-UT theory and conventions is included, along with a detailed description of the operation of the software, how to install the software, and a detailed hardware description.

  16. A Longitudinal Mode Electromagnetic Acoustic Transducer (EMAT Based on a Permanent Magnet Chain for Pipe Inspection

    Directory of Open Access Journals (Sweden)

    Ming Cong

    2016-05-01

    Full Text Available A new electromagnetic acoustic transducer (EMAT design, employing a special structure of the permanent magnet chain, is proposed to generate and receive longitudinal guided waves for pipe inspection based on the magnetostriction mechanism. Firstly, a quantitative analysis of the excitation forces shows the influence of the radial component can be ignored. Furthermore, as the axial component of the static magnetic field is dominant, a method of solenoid testing coils connected in series is adopted to increase the signal amplitude. Then, two EMAT configurations are developed to generate and receive the L(0,2 guided wave mode. The experimental results show the circumferential notch can be identified and located successfully. Finally, a detailed investigation of the performance of the proposed EMATs is given. Compared to the conventional EMAT configuration, the proposed configurations have the advantages of small volume, light weight, easy installation and portability, which is helpful to improve inspection efficiency.

  17. A Longitudinal Mode Electromagnetic Acoustic Transducer (EMAT) Based on a Permanent Magnet Chain for Pipe Inspection.

    Science.gov (United States)

    Cong, Ming; Wu, Xinjun; Qian, Chunqiao

    2016-05-21

    A new electromagnetic acoustic transducer (EMAT) design, employing a special structure of the permanent magnet chain, is proposed to generate and receive longitudinal guided waves for pipe inspection based on the magnetostriction mechanism. Firstly, a quantitative analysis of the excitation forces shows the influence of the radial component can be ignored. Furthermore, as the axial component of the static magnetic field is dominant, a method of solenoid testing coils connected in series is adopted to increase the signal amplitude. Then, two EMAT configurations are developed to generate and receive the L(0,2) guided wave mode. The experimental results show the circumferential notch can be identified and located successfully. Finally, a detailed investigation of the performance of the proposed EMATs is given. Compared to the conventional EMAT configuration, the proposed configurations have the advantages of small volume, light weight, easy installation and portability, which is helpful to improve inspection efficiency.

  18. Report on inspection of the performance based incentive program at the Richland Operations Office

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-10

    The Fiscal Year (FY) 1995 Performance Based Incentive (PBI) Program at the Department of Energy`s (DOE) Richland Operations Office (Richland) was initiated by Richland as one part of the broader DOE Contract Reform Initiative being implemented at the Hanford Site in FY 1995. This program was identified as an area of concern by the Office of Inspections as a result of previous inspection work. Specifically, during a limited review of the construction of an Effluent Treatment Facility at the Hanford Site, we were unable to identify any written policies describing PBI program controls or implementation procedures. We were told that Richland Operations Office Program Management personnel were not directly involved in the selection of the Effluent Treatment Facility project for the PBI Program, or in the determination that this particular PBI would be established with a potential fee of $1 million.

  19. Auxiliary feedwater system risk-based inspection guide for the H. B. Robinson nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Moffitt, N.E.; Lloyd, R.C.; Gore, B.F.; Vo, T.V. [Pacific Northwest Lab., Richland, WA (United States); Garner, L.W. [Nuclear Regulatory Commission, Washington, DC (United States)

    1993-08-01

    In a study sponsored by the US Nuclear Regulatory Commission (NRC), Pacific Northwest Laboratory has developed and applied a methodology for deriving plant-specific risk-based inspection guidance for the auxiliary feedwater (AFW) system at pressurized water reactors that have not undergone probabilistic risk assessment (PRA). This methodology uses existing PRA results and plant operating experience information. Existing PRA-based inspection guidance information recently developed for the NRC for various plants was used to identify generic component failure modes. This information was then combined with plant-specific and industry-wide component information and failure data to identify failure modes and failure mechanisms for the AFW system at the selected plants. H. B. Robinson was selected as one of a series of plants for study. The product of this effort is a prioritized listing of AFW failures which have occurred at the plant and at other PWRs. This listing is intended for use by NRC inspectors in the preparation of inspection plans addressing AFW risk-important components at the H. B. Robinson plant.

  20. Auxiliary feedwater system risk-based inspection guide for the South Texas Project nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Bumgardner, J.D.; Nickolaus, J.R.; Moffitt, N.E.; Gore, B.F.; Vo, T.V. [Pacific Northwest Lab., Richland, WA (United States)

    1993-12-01

    In a study sponsored by the US Nuclear Regulatory Commission (NRC), Pacific Northwest Laboratory has developed and applied a methodology for deriving plant-specific risk-based inspection guidance for the auxiliary feedwater (AFW) system at pressurized water reactors that have not undergone probabilistic risk assessment (PRA). This methodology uses existing PRA results and plant operating experience information. Existing PRA-based inspection guidance information recently developed for the NRC for various plants was used to identify generic component failure modes. This information was then combined with plant-specific and industry-wide component information and failure data to identify failure modes and failure mechanisms for the AFW system at the selected plants. South Texas Project was selected as a plant for study. The product of this effort is a prioritized listing of AFW failures which have occurred at the plant and at other PWRs. This listing is intended for use by the NRC inspectors in preparation of inspection plans addressing AFW risk important components at the South Texas Project plant.

  1. Auxiliary feedwater system risk-based inspection guide for the Point Beach nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Lloyd, R C; Moffitt, N E; Gore, B F; Vo, T V; Vehec, T A [Pacific Northwest Lab., Richland, WA (United States)

    1993-02-01

    In a study sponsored by the US Nuclear Regulatory Commission (NRC), Pacific Northwest Laboratory has developed and applied a methodology for deriving plant-specific risk-based inspection guidance for the auxiliary feedwater (AFW) system at pressurized water reactors that have not undergone probabilistic risk assessment (PRA). This methodology uses existing PRA results and plant operating experience information. Existing PRA-based inspection guidance information recently developed for the NRC for various plants was used to identify generic component failure modes. This information was then combined with plant-specific and industry-wide component information and failure data to identify failure modes and failure mechanisms for the AFW system at the selected plants. Point Beach was selected as one of a series of plants for study. The product of this effort is a prioritized listing of AFW failures which have occurred at the plant and at other PWRS. This listing is intended for use by NRC inspectors in the preparation of inspection plans addressing AFW risk-important components at the Point Beach plant.

  2. Auxiliary feedwater system risk-based inspection guide for the McGuire nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Bumgardner, J.D.; Lloyd, R.C.; Moffitt, N.E.; Gore, B.F.; Vo, T.V. [Pacific Northwest Lab., Richland, WA (United States)

    1994-05-01

    In a study sponsored by the US Nuclear Regulatory Commission (NRC), Pacific Northwest Laboratory has developed and applied a methodology for deriving plant-specific risk-based inspection guidance for the auxiliary feedwater (AFW) system at pressurized water reactors that have not undergone probabilistic risk assessment (PRA). This methodology uses existing PRA results and plant operating experience information. Existing PRA-based inspection guidance information recently developed for the NRC for various plants was used to identify generic component failure modes. This information was then combined with plant-specific and industry-wide component information and failure data to identify failure modes and failure mechanisms for the AFW system at the selected plants. McGuire was selected as one of a series of plants for study. The product of this effort is a prioritized listing of AFW failures which have occurred at the plant and at other PWRs. This listing is intended for use by NRC inspectors in the preparation of inspection plans addressing AFW risk-important components at the McGuire plant.

  3. Auxiliary feedwater system risk-based inspection guide for the Fort Calhoun nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Moffitt, N.E.; Gore, B.F.; Vehec, T.A.; Vo, T.V. [Pacific Northwest Lab., Richland, WA (United States)

    1993-02-01

    In a study sponsored by the US Nuclear Regulatory Commission (NRC), Pacific Northwest Laboratory has developed and applied a methodology for deriving plant-specific risk-based inspection guidance for the auxiliary feedwater (AFW) system at pressurized water reactors that have not undergone probabilistic risk assessment (PRA). This methodology uses existing PRA results and plant operating experience information. Existing PRA-based inspection guidance information recently developed for the NRC for various plants was used to identify generic component failure modes. This information was then combined with plant-specific and industry-wide component information and failure data to identify failure modes and failure mechanisms for the AFW system at the selected plants. Fort Calhoun was selected as the sixth plant for study. The product of this effort is a prioritized listing of AFW failures which have occurred at the plant and at other PWRs. This listing is intended for use by NRC inspectors in the preparation of inspection plans addressing AFW risk-important components at the Fort Calhoun plant.

  4. Surface defect inspection of TFT-LCD panels based on 1D Fourier method

    Science.gov (United States)

    Zhang, Teng-da; Lu, Rong-sheng

    2016-01-01

    Flat panel displays have been used in a wide range of electronic devices. The defects on their surfaces are an important factor affecting the product quality. Automated optical inspection (AOI) method is an important and effective means to perform the surface defection inspection. In this paper, a kind of defect extraction algorithm based on one dimensional (1D) Fourier theory for the surface defect extraction with periodic texture background is introduced. In the algorithm, the scanned surface images are firstly transformed from time domain to frequency domain by 1D Fourier transform. The periodic texture background on the surface is then removed by using filtering methods in the frequency domain. Then, a dual-threshold statistical control method is applied to separate the defects from the surface background. Traditional 1D Fourier transform scheme for detecting ordinary defects is very effective; however, the method is not where the defect direction is close to horizontal in periodic texture background. In order to tackle the problem, a mean threshold method based on faultless image is put forward. It firstly calculates the upper and lower control limits of the every reconstructed line scanned image with faultless and then computes the averages of the upper and lower limits. The averages then act as the constant double thresholds to extract the defects. The experimental results of different defects show that the method developed in the paper is very effective for TFT-LCD panel surface defect inspection even in the circumstance that the defect directions are close to horizontal.

  5. The matching pursuit approach based on the modulated Gaussian pulse for efficient guided-wave damage inspection

    Science.gov (United States)

    Hong, Jin-Chul; Sun, Kyung Ho; Kim, Yoon Young

    2005-08-01

    The success of the guided-wave damage inspection technology depends not only on the generation and measurement of desired waveforms but also on the signal processing of the measured waves, but less attention has been paid to the latter. This research aims to develop an efficient signal processing technique especially suitable for the current guided-wave technology. To achieve this objective, the use of a two-stage matching pursuit approach based on the Gabor dictionary is proposed. Instead of truncated sine pulses commonly used in waveguide inspection, Gabor pulses, the modulated Gaussian pulses, are chosen as the elastic energy carrier to facilitate the matching pursuit algorithm. To extract meaningful waves out of noisy signals, a two-stage matching pursuit strategy is developed, which consists of the following: rough approximations with a set of predetermined parameters characterizing the Gabor pulse, and fine adjustments of the parameters by optimization. The parameters estimated from measured longitudinal elastic waves can be then directly used to assess not only the location but also the size of a crack in a rod. For the estimation of the crack size, in particular, Love's theory is incorporated in the matching pursuit analysis. Several experiments were conducted to verify the validity of the proposed approach in damage assessment.

  6. Optimal design for inspection and maintenance policy based on the CCC chart

    OpenAIRE

    Chan, Ling-Yau; Wu, Shaomin

    2009-01-01

    In this paper, the concept of cumulative count of conforming chart (CCC chart) is applied in inspection and maintenance planning for systems where minor inspection, major inspection, minor maintenance and major maintenance are available. Several inspection and maintenance plans are defined and studied quantitatively. Analytic expressions of relevant statistics and their expectations are derived. These inspection and maintenance plans are optimized from an economic consideration.

  7. Electronic Inspection of Beef

    Science.gov (United States)

    Anselmo, Victor J.; Gammell, Paul M.; Clark, Jerry

    1987-01-01

    Two proposed methods for grading beef quality based on inspection by electronic equipment: one method uses television camera to generate image of a cut of beef as customer sees it; other uses ultrasonics to inspect live animal or unsliced carcasses. Both methods show promise for automated meat inspection.

  8. On automatic visual inspection of reflective surfaces

    DEFF Research Database (Denmark)

    Kulmann, Lionel

    1995-01-01

    surveyed visual inspection system design methods and presented available image processing hardware to perform high resolution image capture. We present general usable practical visual inspection system solutions, when performing high resolution visual inspection of surfaces. We have presented known and new......This thesis descrbes different methods to perform automatic visual inspection of reflective manufactured products, with the aim of increasing productivity, reduce cost and improve the quality level of the production. We investigate two different systems performing automatic visual inspection...... in algorithms for detecting 3-dimensional surface damages based on images from a novel structured lighting setup enhancing the appearance of these defects in specular surfaces. A hardware implementable polynomial classifier structure has been described and compared to better known techniques based...

  9. An Empirical Comparative Study of Checklist-based and Ad Hoc Code Reading Techniques in a Distributed Groupware Environment

    Directory of Open Access Journals (Sweden)

    Adenike O. Osofisan

    2009-09-01

    Full Text Available Software inspection is a necessary and important tool for software quality assurance. Since it was introduced by Fagan at IBM in 1976, arguments exist as to which method should be adopted to carry out the exercise, whether it should be paper-based or tool-based, and what reading technique should be used on the inspection document. Extensive works have been done to determine the effectiveness of reviewers in paper-based environment when using ad hoc and checklist reading techniques. In this work, we take the software inspection research further by examining whether there is going to be any significant difference in defect detection effectiveness of reviewers when they use either ad hoc or checklist reading techniques in a distributed groupware environment. Twenty final year undergraduate students of computer science, divided into ad hoc and checklist reviewers groups of ten members each were employed to inspect a medium-sized java code synchronously on groupware deployed on the Internet. The data obtained were subjected to tests of hypotheses using independent t-test and correlation coefficients. Results from the study indicate that there are no significant differences in the defect detection effectiveness, effort in terms of time taken in minutes and false positives reported by the reviewers using either ad hoc or checklist based reading techniques in the distributed groupware environment studied.Key words: Software Inspection, Ad hoc, Checklist, groupware.

  10. Developing an App by Exploiting Web-Based Mobile Technology to Inspect Controlled Substances in Patient Care Units

    Directory of Open Access Journals (Sweden)

    Ying-Hao Lu

    2017-01-01

    Full Text Available We selected iOS in this study as the App operation system, Objective-C as the programming language, and Oracle as the database to develop an App to inspect controlled substances in patient care units. Using a web-enabled smartphone, pharmacist inspection can be performed on site and the inspection result can be directly recorded into HIS through the Internet, so human error of data translation can be minimized and the work efficiency and data processing can be improved. This system not only is fast and convenient compared to the conventional paperwork, but also provides data security and accuracy. In addition, there are several features to increase inspecting quality: (1 accuracy of drug appearance, (2 foolproof mechanism to avoid input errors or miss, (3 automatic data conversion without human judgments, (4 online alarm of expiry date, and (5 instant inspection result to show not meted items. This study has successfully turned paper-based medication inspection into inspection using a web-based mobile device.

  11. Developing an App by Exploiting Web-Based Mobile Technology to Inspect Controlled Substances in Patient Care Units

    Science.gov (United States)

    2017-01-01

    We selected iOS in this study as the App operation system, Objective-C as the programming language, and Oracle as the database to develop an App to inspect controlled substances in patient care units. Using a web-enabled smartphone, pharmacist inspection can be performed on site and the inspection result can be directly recorded into HIS through the Internet, so human error of data translation can be minimized and the work efficiency and data processing can be improved. This system not only is fast and convenient compared to the conventional paperwork, but also provides data security and accuracy. In addition, there are several features to increase inspecting quality: (1) accuracy of drug appearance, (2) foolproof mechanism to avoid input errors or miss, (3) automatic data conversion without human judgments, (4) online alarm of expiry date, and (5) instant inspection result to show not meted items. This study has successfully turned paper-based medication inspection into inspection using a web-based mobile device. PMID:28286761

  12. Developing an App by Exploiting Web-Based Mobile Technology to Inspect Controlled Substances in Patient Care Units.

    Science.gov (United States)

    Lu, Ying-Hao; Lee, Li-Yao; Chen, Ying-Lan; Cheng, Hsing-I; Tsai, Wen-Tsung; Kuo, Chen-Chun; Chen, Chung-Yu; Huang, Yaw-Bin

    2017-01-01

    We selected iOS in this study as the App operation system, Objective-C as the programming language, and Oracle as the database to develop an App to inspect controlled substances in patient care units. Using a web-enabled smartphone, pharmacist inspection can be performed on site and the inspection result can be directly recorded into HIS through the Internet, so human error of data translation can be minimized and the work efficiency and data processing can be improved. This system not only is fast and convenient compared to the conventional paperwork, but also provides data security and accuracy. In addition, there are several features to increase inspecting quality: (1) accuracy of drug appearance, (2) foolproof mechanism to avoid input errors or miss, (3) automatic data conversion without human judgments, (4) online alarm of expiry date, and (5) instant inspection result to show not meted items. This study has successfully turned paper-based medication inspection into inspection using a web-based mobile device.

  13. Model-based software for simulating ultrasonic pulse/echo inspections of metal components

    Science.gov (United States)

    Chiou, Chien-Ping; Margetan, Frank J.; Taylor, Jared L.; McKillip, Matthew; Engle, Brady J.; Roberts, Ronald A.; Barnard, Daniel J.

    2017-02-01

    Under the sponsorship of the National Science Foundation's Industry/University Cooperative Research Center at Iowa State University, an effort was initiated in 2015 to repackage existing research-grade software into user friendly tools for the rapid estimation of signal-to-noise ratio (S/N) for ultrasonic inspections of metals. The software combines: (1) a Python-based graphical user interface for specifying an inspection scenario and displaying results; and (2) a Fortran-based engine for computing defect signals and backscattered grain noise characteristics. The later makes use the Thompson-Gray Model for the response from an internal defect and the Independent Scatterer Model for backscattered grain noise. This paper provides an overview of the ongoing modeling effort with emphasis on recent developments. These include: treatment of angle-beam inspections, implementation of distance-amplitude corrections, changes in the generation of "invented" calibration signals, efforts to simulate ultrasonic C-scans; and experimental testing of model predictions. The simulation software can now treat both normal and oblique-incidence immersion inspections of curved metal components having equiaxed microstructures in which the grain size varies with depth. Both longitudinal and shear-wave inspections are treated. The model transducer can either be planar, spherically-focused, or bi-cylindrically-focused. A calibration (or reference) signal is required and is used to deduce the measurement system efficiency function. This can be "invented" by the software using center frequency and bandwidth information specified by the user, or, alternatively, a measured calibration signal can be used. Defect types include flat-bottomed-hole reference reflectors, and spherical pores and inclusions. Simulation outputs include estimated defect signal amplitudes, root-mean-squared grain noise amplitudes, and S/N as functions of the depth of the defect within the metal component. At any particular

  14. Graph based techniques for tag cloud generation

    DEFF Research Database (Denmark)

    Leginus, Martin; Dolog, Peter; Lage, Ricardo Gomes

    2013-01-01

    Tag cloud is one of the navigation aids for exploring documents. Tag cloud also link documents through the user defined terms. We explore various graph based techniques to improve the tag cloud generation. Moreover, we introduce relevance measures based on underlying data such as ratings or citat......Tag cloud is one of the navigation aids for exploring documents. Tag cloud also link documents through the user defined terms. We explore various graph based techniques to improve the tag cloud generation. Moreover, we introduce relevance measures based on underlying data such as ratings...

  15. Optimization of probes for the integration of ET techniques in the inspection of tubes GGV; Optimizacion de sondas para la integracion de tecnicas ET en la inspeccion de tubos de GGV

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Bueno, A.; Jimenez Garcia, J. J.; Hernandez Estrada, R.; Mendez Canete, M.

    2012-07-01

    The appearance of the degradation phenomenon called denting tubes in some models of GV, and the need to characterize this type of information and its consequences on the one hand, and to optimize the inspection times on the other, has shown the desirability of develop new probes that integrate different inspection techniques to obtain the maximum information from the degradation phenomena, the minimum inspection times.

  16. A study on laser-based ultrasonic technique by the use of guided wave tomographic imaging

    Energy Technology Data Exchange (ETDEWEB)

    Park, Junpil, E-mail: jpp@pusan.ac.kr; Lim, Juyoung, E-mail: jpp@pusan.ac.kr [Graduate school, School of Mechanical Engineering, Pusan National University (Korea, Republic of); Cho, Younho [School of Mechanical Engineering, Pusan National University (Korea, Republic of); Krishnaswamy, Sridhar [Center for Quality Engineering and Failure Prevention, Northwestern University, Evanston, IL (United States)

    2015-03-31

    Guided wave tests are impractical for investigating specimens with limited accessibility and coarse surfaces or geometrically complicated features. A non-contact setup with a laser ultrasonic transmitter and receiver is the classic attractive for guided wave inspection. The present work was done to develop a non-contact guided-wave tomography technique by laser ultrasonic technique in a plate-like structure. A method for Lam wave generation and detection in an aluminum plate with a pulse laser ultrasonic transmitter and a Michelson interferometer receiver has been developed. In the images obtained by laser scanning, the defect shape and area showed good agreement with the actual defect. The proposed approach can be used as a non-contact-based online inspection and monitoring technique.

  17. A multi-component and multi-failure mode inspection model based on the delay time concept

    Energy Technology Data Exchange (ETDEWEB)

    Wang Wenbin, E-mail: w.wang@salford.ac.u [Salford Business School, University of Salford, Salford, M5 4WT (United Kingdom); PHM Centre of City University of Hong Kong (Hong Kong); Banjevic, Dragan [Department of Mechanical and Industrial Engineering, University of Toronto (Canada); Pecht, Michael [PHM Centre of City University of Hong Kong (Hong Kong); CALCE Electronic Products and Systems, University of Maryland, College Park, MD 20742 (United States)

    2010-08-15

    The delay time concept and the techniques developed for modelling and optimising plant inspection practices have been reported in many papers and case studies. For a system comprised of many components and subject to many different failure modes, one of the most convenient ways to model the inspection and failure processes is to use a stochastic point process for defect arrivals and a common delay time distribution for the duration between defect the arrival and failure of all defects. This is an approximation, but has been proven to be valid when the number of components is large. However, for a system with just a few key components and subject to few major failure modes, the approximation may be poor. In this paper, a model is developed to address this situation, where each component and failure mode is modelled individually and then pooled together to form the system inspection model. Since inspections are usually scheduled for the whole system rather than individual components, we then formulate the inspection model when the time to the next inspection from the point of a component failure renewal is random. This imposes some complication to the model, and an asymptotic solution was found. Simulation algorithms have also been proposed as a comparison to the analytical results. A numerical example is presented to demonstrate the model.

  18. On-line surface inspection using cylindrical lens-based spectral domain low-coherence interferometry.

    Science.gov (United States)

    Tang, Dawei; Gao, Feng; Jiang, X

    2014-08-20

    We present a spectral domain low-coherence interferometry (SD-LCI) method that is effective for applications in on-line surface inspection because it can obtain a surface profile in a single shot. It has an advantage over existing spectral interferometry techniques by using cylindrical lenses as the objective lenses in a Michelson interferometric configuration to enable the measurement of long profiles. Combined with a modern high-speed CCD camera, general-purpose graphics processing unit, and multicore processors computing technology, fast measurement can be achieved. By translating the tested sample during the measurement procedure, real-time surface inspection was implemented, which is proved by the large-scale 3D surface measurement in this paper. ZEMAX software is used to simulate the SD-LCI system and analyze the alignment errors. Two step height surfaces were measured, and the captured interferograms were analyzed using a fast Fourier transform algorithm. Both 2D profile results and 3D surface maps closely align with the calibrated specifications given by the manufacturer.

  19. Techniques of Image Processing Based on Artificial Neural Networks

    Institute of Scientific and Technical Information of China (English)

    LI Wei-qing; WANG Qun; WANG Cheng-biao

    2006-01-01

    This paper presented an online quality inspection system based on artificial neural networks. Chromatism classification and edge detection are two difficult problems in glass steel surface quality inspection. Two artificial neural networks were made and the two problems were solved. The one solved chromatism classification. Hue,saturation and their probability of three colors, whose appearing probabilities were maximum in color histogram,were selected as input parameters, and the number of output node could be adjusted with the change of requirement. The other solved edge detection. In this neutral network, edge detection of gray scale image was able to be tested with trained neural networks for a binary image. It prevent the difficulty that the number of needed training samples was too large if gray scale images were directly regarded as training samples. This system is able to be applied to not only glass steel fault inspection but also other product online quality inspection and classification.

  20. Flow Modeling Based Wall Element Technique

    Directory of Open Access Journals (Sweden)

    Sabah Tamimi

    2012-08-01

    Full Text Available Two types of flow where examined, pressure and combination of pressure and Coquette flow of confined turbulent flow with a one equation model used to depict the turbulent viscosity of confined flow in a smooth straight channel when a finite element technique based on a zone close to a solid wall has been adopted for predicting the distribution of the pertinent variables in this zone and examined even with case when the near wall zone was extended away from the wall. The validation of imposed technique has been tested and well compared with other techniques.

  1. Validation of the ultrasonic and Eddy current techniques to inspect the accommodation of the elements of (CRDH) control rod drive; Validacion de las tecnicas de ultrasonidos y corrientes inducidas para inspeccionar los alojamientos

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, A.; Gomez, P.; Sanchez, J.; Resa, P.

    2013-07-01

    Tecnatom development in the past with ultrasonic inspection procedures to examine vessels BWR of several Central nuclear (CRDH) control rod drive elements, accommodations. In each case, inspection techniques have relied on both the volume of required test postulated defects. Also, taking into account the possible access to the component, developed mechanical equipments of different characteristics.

  2. Characterization of spent fuel elements stored at IEA-R1 research reactor based on visual inspections and sipping tests

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Jose Eduardo Rosa da; Terremoto, Luis Antonio Albiac; Teodoro, Celso Antonio; Castanheira, Myrthes; Lucki, Georgi; Damy, Margaret de Almeida; Silva, Antonio Teixeira e [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: jersilva@ipen.br

    2005-07-01

    Aluminum spent nuclear fuels are susceptible to corrosion attack, or mechanical damage from improper handling, while in pool reactor storage. Storage practices have been modified to reduce the potential for damage, based on recommendations presented at second WS on Spent Fuel Characterization, promoted by IAEA. In this work, we present the inspection program proposed to the IEA-R1 stored spent fuel elements, in order to provide information on the physical condition during the interim storage time under wet condition at the reactor pool. The inspection program is based on non-destructive tests results (visual inspection and sipping tests) already periodically performed to exam the IEA-R1 stored spent fuel and fuel elements from the core reactor. To record the available information and examination results it was elaborated a document in the format of a catalogue containing the proposed inspection program for the IEA-R1 stored spent fuel, the description of the visual inspection and sipping tests systems, a compilation of information and images result from the tests performed for all stored standard spent fuel element and, in annexes, copies of the reference documents. That document constitutes an important step of the effective implementation of the referred IEA-R1 spent fuel inspection program and can be used to address regulatory and operational needs for the demonstration, for example, of safe storage throughout the pool storage period. (author)

  3. Low-Cost Impact Detection and Location for Automated Inspections of 3D Metallic Based Structures

    Directory of Open Access Journals (Sweden)

    Carlos Morón

    2015-05-01

    Full Text Available This paper describes a new low-cost means to detect and locate mechanical impacts (collisions on a 3D metal-based structure. We employ the simple and reasonably hypothesis that the use of a homogeneous material will allow certain details of the impact to be automatically determined by measuring the time delays of acoustic wave propagation throughout the 3D structure. The location of strategic piezoelectric sensors on the structure and an electronic-computerized system has allowed us to determine the instant and position at which the impact is produced. The proposed automatic system allows us to fully integrate impact point detection and the task of inspecting the point or zone at which this impact occurs. What is more, the proposed method can be easily integrated into a robot-based inspection system capable of moving over 3D metallic structures, thus avoiding (or minimizing the need for direct human intervention. Experimental results are provided to show the effectiveness of the proposed approach.

  4. A Shape Based Image Search Technique

    Directory of Open Access Journals (Sweden)

    Aratrika Sarkar

    2014-08-01

    Full Text Available This paper describes an interactive application we have developed based on shaped-based image retrieval technique. The key concepts described in the project are, imatching of images based on contour matching; iimatching of images based on edge matching; iiimatching of images based on pixel matching of colours. Further, the application facilitates the matching of images invariant of transformations like i translation ; ii rotation; iii scaling. The key factor of the system is, the system shows the percentage unmatched of the image uploaded with respect to the images already existing in the database graphically, whereas, the integrity of the system lies on the unique matching techniques used for optimum result. This increases the accuracy of the system. For example, when a user uploads an image say, an image of a mango leaf, then the application shows all mango leaves present in the database as well other leaves matching the colour and shape of the mango leaf uploaded.

  5. A flexible 3D vision system based on structured light for in-line product inspection

    Science.gov (United States)

    Skotheim, Øystein; Nygaard, Jens Olav; Thielemann, Jens; Vollset, Thor

    2008-02-01

    A flexible and highly configurable 3D vision system targeted for in-line product inspection is presented. The system includes a low cost 3D camera based on structured light and a set of flexible software tools that automate the measurement process. The specification of the measurement tasks is done in a first manual step. The user selects regions of the point cloud to analyze and specifies primitives to be characterized within these regions. After all measurement tasks have been specified, measurements can be carried out on successive parts automatically and without supervision. As a test case, a measurement cell for inspection of a V-shaped car component has been developed. The car component consists of two steel tubes attached to a central hub. Each of the tubes has an additional bushing clamped to its end. A measurement is performed in a few seconds and results in an ordered point cloud with 1.2 million points. The software is configured to fit cylinders to each of the steel tubes as well as to the inside of the bushings of the car part. The size, position and orientation of the fitted cylinders allow us to measure and verify a series of dimensions specified on the CAD drawing of the component with sub-millimetre accuracy.

  6. NFC based Inspection and Qualification Management (NIQM) System Preventing Counterfeit and Fraudulent Item

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Choong Koo; Kim, Young Joo [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2013-10-15

    Design, manufacturing, fabrication, transportation and installation of the devices and equipment for nuclear power plants shall be conducted under the thorough quality assurance program for the nuclear safety. However, from late in the 1980s, NRC began to issue a number of communications alerting licenses to issues involving counterfeit and fraudulent items. A number of incidents identified by the NRC in the 1980s and 1990s catalyzed the US nuclear industry to adopt standard precautions to guard against counterfeit items. The purpose of this paper is to develop the NFC (Near Field Communication) based Inspection and Qualification Management(NIQM) system preventing counterfeit and fraudulent items. NFC is one of the latest wireless communication technologies. As a short-range wireless connectivity technology, NFC offers safe-yet simple and intuitive-communication between electronic devices. As described above, NFC technology can be applied to the inspection and qualification management system very effectively to prevent counterfeit and fraudulent items. In addition, NIQM system can use existing data and information through the interface with legacy system.

  7. Application of the perspective-based reading technique in the nuclear I and C context. CORSICA work report 2011

    Energy Technology Data Exchange (ETDEWEB)

    Lahtinen, J.

    2012-07-01

    Inspections and reviews are one of the most effective ways of detecting errors in software development. The methods are also cost-effective because defects can be spotted early in the development, and thus the cost of repairing the defects is lower. Reading techniques are the procedures that are used in the inspection or review of a software artefact. The most common procedures are simple ad-hoc reading and a checklist- based reading technique. However, more advanced and detailed procedures have been created for various purposes. This report reviews the state-of-the-art software reading techniques used in inspections and reviews, and briefly reviews some of the empirical research in this context. The majority of the empirical research results indicate that, for example, perspective-based reading is more cost-effective and can detect more defects than more basic reading techniques. This report also describes how perspective-based reading can be applied to the inspection of nuclear-domain requirement specifications. For this purpose, seven perspective-based reading scenarios have been created. (orig.)

  8. IMAGE ANALYSIS BASED ON EDGE DETECTION TECHNIQUES

    Institute of Scientific and Technical Information of China (English)

    纳瑟; 刘重庆

    2002-01-01

    A method that incorporates edge detection technique, Markov Random field (MRF), watershed segmentation and merging techniques was presented for performing image segmentation and edge detection tasks. It first applies edge detection technique to obtain a Difference In Strength (DIS) map. An initial segmented result is obtained based on K-means clustering technique and the minimum distance. Then the region process is modeled by MRF to obtain an image that contains different intensity regions. The gradient values are calculated and then the watershed technique is used. DIS calculation is used for each pixel to define all the edges (weak or strong) in the image. The DIS map is obtained. This help as priority knowledge to know the possibility of the region segmentation by the next step (MRF), which gives an image that has all the edges and regions information. In MRF model,gray level l, at pixel location i, in an image X, depends on the gray levels of neighboring pixels. The segmentation results are improved by using watershed algorithm. After all pixels of the segmented regions are processed, a map of primitive region with edges is generated. The edge map is obtained using a merge process based on averaged intensity mean values. A common edge detectors that work on (MRF) segmented image are used and the results are compared. The segmentation and edge detection result is one closed boundary per actual region in the image.

  9. Optimal condition-based maintenance strategy under periodic inspections for traction motor insulations

    Institute of Scientific and Technical Information of China (English)

    Jian ZHANG; Ji-en MA; Xiao-yan HUANG; You-tong FANG; He ZHANG

    2015-01-01

    目的:充分利用寿命信息,并考虑冲击效应对维修策略的影响,提出符合牵引电机绝缘运行特征的最优视情维修策略。  方法:1.采用正常状态、潜在故障状态与功能故障状态描述牵引电机绝缘运行状况;2.应用泊松过程描述随机高电压冲击;3.以单位时间的运行成本为目标函数,以监测间隔和预防性维修寿命阈值为优化变量,建立最优视情维修决策模型。  结论:该模型能显著降低牵引电机绝缘功能故障的风险,同时降低单位时间运行成本。%Insulation failure is a crucial failure mode of traction motors. Insulation deteriorates under both fatigue load and shock. This paper focuses on proposing an optimal insulation condition-based maintenance strategy. By combining the infor-mation obtained from periodic inspections with historic life information, an integrated model of time-based maintenance and condition-based model is proposed, in which random shocks following Poisson process are also taken into account. In this model we define that insulation has three states: normal state, latent failure state, and functional failure state. Normal state and latent failure state differ in their operating cost, proneness to functional failure, and survival probability under extreme shocks. Preven-tive maintenance (PM) will be launched if an inspection result exceeds the threshold or if the operating time reaches the critical age. One operating cycle ends as soon as a preventive maintenance or a corrective maintenance is completed. Moreover, an op-timization model is established, which takes minimal cost per unit time as the objective, and inspection interval and critical age as the optimization variables. Finally, a numerical example illustrates the analytic results.

  10. Inspection Strategies for Concrete Bridges

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Thoft-Christensen, Palle

    1989-01-01

    In this paper an optimal inspection strategy for concrete bridges based on periodic routine and detailed inspections is presented. The failure mode considered is corrosion of the reinforcement due to chlorides. A simple modelling of the corrosion and of the inspection strategy is presented....... The optimal inspection strategy is determined from an optimization problem, where the design variables are time intervals between detailed inspections and the concrete cover. The strategy is illustrated on a simple structure, namely a reinforced concrete beam....

  11. Rapid Tooling Technique Based on Stereolithograph Prototype

    Institute of Scientific and Technical Information of China (English)

    丁浩; 狄平; 顾伟生; 朱世根

    2001-01-01

    Rapid tooling technique based on the sterelithograph prototype is investigated. The epoxy tooling technological process was elucidated. It is analyzed in detail that the epoxy resin formula is easy to cast, curing process, and release agents. The transitional plaster model is also proposed. The mold to encrust mutual.inductors with epoxy and mold to inject plastic soapboxes was made with the technique The tooling needs very little time and cost, for the process is only to achieve the nice replica of the prototype. It is benefit for the trial and small batch of production.

  12. Language Based Techniques for Systems Biology

    DEFF Research Database (Denmark)

    Pilegaard, Henrik

    calculi have similarly been used for the study of bio-chemical reactive systems. In this dissertation it is argued that techniques rooted in the theory and practice of programming languages, language based techniques if you will, constitute a strong basis for the investigation of models of biological.......g., the effects of receptor defects or drug delivery mechanisms. The property of sequential realisability. which is closely related to the function of biochemical pathways, is addressed by a variant of traditional Data Flow Analysis (DFA). This so-called ‘Pathway Analysis’ computes safe approximations to the set...

  13. 24 CFR 35.1320 - Lead-based paint inspections, paint testing, risk assessments, lead-hazard screens, and...

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Lead-based paint inspections, paint testing, risk assessments, lead-hazard screens, and reevaluations. 35.1320 Section 35.1320 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development LEAD-BASED...

  14. Estimation of Characteristics of a Software Team for Implementing Effective Inspection Process through Inspection Performance Metric

    CERN Document Server

    Nair, T R Gopalakrishnan

    2011-01-01

    The continued existence of any software industry depends on its capability to develop nearly zero-defect product, which is achievable through effective defect management. Inspection has proven to be one of the promising techniques of defect management. Introductions of metrics like, Depth of Inspection (DI, a process metric) and Inspection Performance Metric (IPM, a people metric) enable one to have an appropriate measurement of inspection technique. This article elucidates a mathematical approach to estimate the IPM value without depending on shop floor defect count at every time. By applying multiple linear regression models, a set of characteristic coefficients of the team is evaluated. These coefficients are calculated from the empirical projects that are sampled from the teams of product-based and service-based IT industries. A sample of three verification projects indicates a close match between the IPM values obtained from the defect count (IPMdc) and IPM values obtained using the team coefficients usi...

  15. 阵列探头在传热管管板区涡流检测中的应用%The Feasibility Research of Array Probe Technique on Eddy Current Inspection of Tube Sheet Area

    Institute of Scientific and Technical Information of China (English)

    曹刚; 师绍猛; 袁建中; 杨敏

    2011-01-01

    Bobbin probes are used to inspect tubes of the condenser, but the inspection is subjected with the "blind area" problem near the tube sheet. Based on this inspection requirement, the application of CXB (Circ X+ Bobbin probe, a kind of array probe) on eddy current inspection of tube sheet area is under discussed. Experiment results by mockup show that CXB is capable of solving "blind area" problems encountered in tube sheet area with bobbin technique. In addition, the problem of CXB quantitative evaluation of defects is figured out successfully. Finally, site results are shown.%传统上采用Bobbin探头进行凝汽器传热管涡流检测时存在管板盲区问题。基于传热管管板区涡流检测需求,研究了CXB型阵列探头在此领域的应用。通过设计制作凝汽器模拟管板,开展了试验研究。试验发现,CXB探头能够有效解决涡流检测中Bobbin探头在传热管管板区存在的盲区问题。同时,试验解决了CXB探头对于缺陷的定量评定难题。最后给出了现场检测中的实际应用结果。

  16. Condition-based inspection/replacement policies for non-monotone deteriorating systems with environmental covariates

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Xuejing [Universite de Technologie de Troyes, Institut Charles Delaunay and STMR UMR CNRS 6279, 12 rue Marie Curie, 10010 Troyes (France); School of mathematics and statistics, Lanzhou University, Lanzhou 730000 (China); Fouladirad, Mitra, E-mail: mitra.fouladirad@utt.f [Universite de Technologie de Troyes, Institut Charles Delaunay and STMR UMR CNRS 6279, 12 rue Marie Curie, 10010 Troyes (France); Berenguer, Christophe [Universite de Technologie de Troyes, Institut Charles Delaunay and STMR UMR CNRS 6279, 12 rue Marie Curie, 10010 Troyes (France); Bordes, Laurent [Universite de Pau et des Pays de l' Adour, LMA UMR CNRS 5142, 64013 PAU Cedex (France)

    2010-08-15

    The aim of this paper is to discuss the problem of modelling and optimising condition-based maintenance policies for a deteriorating system in presence of covariates. The deterioration is modelled by a non-monotone stochastic process. The covariates process is assumed to be a time-homogenous Markov chain with finite state space. A model similar to the proportional hazards model is used to show the influence of covariates on the deterioration. In the framework of the system under consideration, an appropriate inspection/replacement policy which minimises the expected average maintenance cost is derived. The average cost under different conditions of covariates and different maintenance policies is analysed through simulation experiments to compare the policies performances.

  17. Hand-eye-vision based control for an inspection robot’s autonomous line grasping

    Institute of Scientific and Technical Information of China (English)

    王伟; 吴功平; 白玉成; 肖华; 杨智勇; 严宇; 何缘; 徐显金; 苏帆

    2014-01-01

    In order to ensure that the off-line arm of a two-arm-wheel combined inspection robot can reliably grasp the line in case of autonomous obstacle crossing, a control method is proposed for line grasping based on hand-eye visual servo. On the basis of the transmission line’s geometrical characteristics and the camera’s imaging principle, a line recognition and extraction method based on structure constraint is designed. The line’s intercept and inclination are defined in an imaging space to represent the robot’s change of pose and a law governing the pose decoupling servo control is developed. Under the integrated consideration of the influence of light intensity and background change, noise (from the camera itself and electromagnetic field) as well as the robot’s kinetic inertia on the robot’s imaging quality in the course of motion and the grasping control precision, a servo controller for grasping the line of the robot’s off-line arm is designed with the method of fuzzy control. An experiment is conducted on a 1:1 simulation line using an inspection robot and the robot is put into on-line operation on a real overhead transmission line, where the robot can grasp the line within 18 s in the case of autonomous obstacle-crossing. The robot’s autonomous line-grasping function is realized without manual intervention and the robot can grasp the line in a precise, reliable and efficient manner, thus the need of actual operation can be satisfied.

  18. Bypassing of stems versus linear base-by-base inspection of mammalian mRNAs during ribosomal scanning.

    Science.gov (United States)

    Abaeva, Irina S; Marintchev, Assen; Pisareva, Vera P; Hellen, Christopher U T; Pestova, Tatyana V

    2011-01-05

    Initiation codon selection in eukaryotes involves base-by-base inspection of the 5'-untranslated region of mRNA by scanning ribosomal 43S preinitiation complexes. We employed in vitro reconstitution to investigate factor requirements for this process and report that in the absence of eIF1 and DHX29, eIFs 4A, 4B and 4G promote efficient bypassing of stable stems by scanning 43S complexes and formation of 48S initiation complexes on AUG codons immediately upstream and downstream of such stems, without their unwinding. However, intact stems are not threaded through the entire mRNA Exit channel of the 40S subunit, resulting in incorrect positioning of mRNA upstream of the ribosomal P site in 48S complexes formed on AUG codons following intact stems, which renders them susceptible to dissociation by eIF1. In 48S complexes formed on AUG codons preceding intact stems, the stems are accommodated in the A site. Such aberrant complexes are destabilized by DHX29, which also ensures that mRNA enters the mRNA-binding cleft in a single-stranded form and therefore undergoes base-by-base inspection during scanning.

  19. Interactive early warning technique based on SVDD

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    After reviewing current researches on early warning,it is found that"bad" data of some systems is not easy to obtain,which makes methods proposed by these researches unsuitable for monitored systems.An interactive early warning technique based on SVDD(support vector data description)is proposed to adopt"good" data as samples to overcome the difficulty in obtaining the"bad"data.The process consists of two parts:(1)A hypersphere is fitted on"good"data using SVDD.If the data object are outside the hypersphere,it would be taken as"suspicious";(2)A group of experts would decide whether the suspicious data is"bad"or"good",early warning messages would be issued according to the decisions.And the detailed process of implementation is proposed.At last,an experiment based on data of a macroeconomic system is conducted to verify the proposed technique.

  20. MATRIX BASED INDEXING TECHNIQUE FOR VIDEO DATA

    Directory of Open Access Journals (Sweden)

    Devarj Saravanan

    2013-01-01

    Full Text Available Due to increasing the usage of media, the utilization of video play central role as it supports various applications. Video is the particular media which contains complex collection of objects like audio, motion, text, color and picture. Due to the rapid growth of this information video indexing process is mandatory for fast and effective retrieval. Many current indexing techniques fails to extract the needed image from the stored data set, based on the users query. Urgent attention in the field of video indexing and image retrieval is the need of the hour. Here a new matrix based indexing technique for image retrieval has been proposed. The proposed method provide better result, experimental results prove this.

  1. MATRIX BASED INDEXING TECHNIQUE FOR VIDEO DATA

    OpenAIRE

    2013-01-01

    Due to increasing the usage of media, the utilization of video play central role as it supports various applications. Video is the particular media which contains complex collection of objects like audio, motion, text, color and picture. Due to the rapid growth of this information video indexing process is mandatory for fast and effective retrieval. Many current indexing techniques fails to extract the needed image from the stored data set, based on the users query. Urgent attention in the fi...

  2. Multiview video codec based on KTA techniques

    Science.gov (United States)

    Seo, Jungdong; Kim, Donghyun; Ryu, Seungchul; Sohn, Kwanghoon

    2011-03-01

    Multi-view video coding (MVC) is a video coding standard developed by MPEG and VCEG for multi-view video. It showed average PSNR gain of 1.5dB compared with view-independent coding by H.264/AVC. However, because resolutions of multi-view video are getting higher for more realistic 3D effect, high performance video codec is needed. MVC adopted hierarchical B-picture structure and inter-view prediction as core techniques. The hierarchical B-picture structure removes the temporal redundancy, and the inter-view prediction reduces the inter-view redundancy by compensated prediction from the reconstructed neighboring views. Nevertheless, MVC has inherent limitation in coding efficiency, because it is based on H.264/AVC. To overcome the limit, an enhanced video codec for multi-view video based on Key Technology Area (KTA) is proposed. KTA is a high efficiency video codec by Video Coding Expert Group (VCEG), and it was carried out for coding efficiency beyond H.264/AVC. The KTA software showed better coding gain than H.264/AVC by using additional coding techniques. The techniques and the inter-view prediction are implemented into the proposed codec, which showed high coding gain compared with the view-independent coding result by KTA. The results presents that the inter-view prediction can achieve higher efficiency in a multi-view video codec based on a high performance video codec such as HEVC.

  3. Inspection Database

    Data.gov (United States)

    U.S. Department of Health & Human Services — FDA is disclosing the final inspection classification for inspections related to currently marketed FDA-regulated products. The disclosure of this information is not...

  4. Inspection Database

    Data.gov (United States)

    U.S. Department of Health & Human Services — FDA is disclosing the final inspection classification for inspections related to currently marketed FDA-regulated products. The disclosure of this information is...

  5. A novel biometric X-ray backscatter inspection of dangerous materials based on a lobster-eye objective

    Science.gov (United States)

    Xu, Jie; Wang, Xin; Mu, Baozhong; Zhan, Qi; Xie, Qing; Li, Yaran; Chen, Yifan; He, Yanan

    2016-10-01

    In order to counter drug-related crimes effectively, and to safeguard homeland security as well as public safety, it is important to inspect drugs, explosives and other contraband quickly and accurately from the express mail system, luggage, vehicles and other objects. In this paper, we discuss X-ray backscatter inspection system based on a novel lobster-eye X-ray objective, which is an effective inspection technology for drugs, explosives and other contraband inspection. Low atomic number materials, such as drugs and explosives, leads to strong Compton scattering after irradiated by X-ray, which is much stronger than high atomic number material, such as common metals, etc. By detecting the intensity of scattering signals, it is possible to distinguish between organics and inorganics. The lobster-eye X-ray optical system imitates the reflective eyes of lobsters, which field of view can be made as large as desired and it is practical to achieve spatial resolution of several millimeters for finite distance detection. A novel lobster-eye X-ray objective is designed based on modifying Schmidt geometry by using multi-lens structure, so as to reduce the difference of resolution between the horizontal and vertical directions. The demonstration experiments of X-ray backscattering imaging were carried out. A suitcase, a wooden box and a tire with several typical samples hidden in them were imaged by the X-ray backscattering inspection system based on a lobster-eye X-ray objective. The results show that this X-ray backscattering inspection system can get a resolution of less than five millimeters under the FOV of more than two hundred millimeters with 0.5 meter object distance, which can still be improved.

  6. Vision-Based Corrosion Detection Assisted by a Micro-Aerial Vehicle in a Vessel Inspection Application.

    Science.gov (United States)

    Ortiz, Alberto; Bonnin-Pascual, Francisco; Garcia-Fidalgo, Emilio; Company-Corcoles, Joan P

    2016-12-14

    Vessel maintenance requires periodic visual inspection of the hull in order to detect typical defective situations of steel structures such as, among others, coating breakdown and corrosion. These inspections are typically performed by well-trained surveyors at great cost because of the need for providing access means (e.g., scaffolding and/or cherry pickers) that allow the inspector to be at arm's reach from the structure under inspection. This paper describes a defect detection approach comprising a micro-aerial vehicle which is used to collect images from the surfaces under inspection, particularly focusing on remote areas where the surveyor has no visual access, and a coating breakdown/corrosion detector based on a three-layer feed-forward artificial neural network. As it is discussed in the paper, the success of the inspection process depends not only on the defect detection software but also on a number of assistance functions provided by the control architecture of the aerial platform, whose aim is to improve picture quality. Both aspects of the work are described along the different sections of the paper, as well as the classification performance attained.

  7. Vision-Based Corrosion Detection Assisted by a Micro-Aerial Vehicle in a Vessel Inspection Application

    Directory of Open Access Journals (Sweden)

    Alberto Ortiz

    2016-12-01

    Full Text Available Vessel maintenance requires periodic visual inspection of the hull in order to detect typical defective situations of steel structures such as, among others, coating breakdown and corrosion. These inspections are typically performed by well-trained surveyors at great cost because of the need for providing access means (e.g., scaffolding and/or cherry pickers that allow the inspector to be at arm’s reach from the structure under inspection. This paper describes a defect detection approach comprising a micro-aerial vehicle which is used to collect images from the surfaces under inspection, particularly focusing on remote areas where the surveyor has no visual access, and a coating breakdown/corrosion detector based on a three-layer feed-forward artificial neural network. As it is discussed in the paper, the success of the inspection process depends not only on the defect detection software but also on a number of assistance functions provided by the control architecture of the aerial platform, whose aim is to improve picture quality. Both aspects of the work are described along the different sections of the paper, as well as the classification performance attained.

  8. A vision-based self-calibration method for robotic visual inspection systems.

    Science.gov (United States)

    Yin, Shibin; Ren, Yongjie; Zhu, Jigui; Yang, Shourui; Ye, Shenghua

    2013-12-03

    A vision-based robot self-calibration method is proposed in this paper to evaluate the kinematic parameter errors of a robot using a visual sensor mounted on its end-effector. This approach could be performed in the industrial field without external, expensive apparatus or an elaborate setup. A robot Tool Center Point (TCP) is defined in the structural model of a line-structured laser sensor, and aligned to a reference point fixed in the robot workspace. A mathematical model is established to formulate the misalignment errors with kinematic parameter errors and TCP position errors. Based on the fixed point constraints, the kinematic parameter errors and TCP position errors are identified with an iterative algorithm. Compared to the conventional methods, this proposed method eliminates the need for a robot-based-frame and hand-to-eye calibrations, shortens the error propagation chain, and makes the calibration process more accurate and convenient. A validation experiment is performed on an ABB IRB2400 robot. An optimal configuration on the number and distribution of fixed points in the robot workspace is obtained based on the experimental results. Comparative experiments reveal that there is a significant improvement of the measuring accuracy of the robotic visual inspection system.

  9. A condition-based maintenance policy with non-periodic inspections for a two-unit series system

    Energy Technology Data Exchange (ETDEWEB)

    Castanier, B. [IRCCyN/Ecole des Mines de Nantes, Departement Automatique et Productique, 4 rue Alfred Kastler, F-44307 Nantes (France)]. E-mail: bruno.castanier@emn.fr; Grall, A. [Universite de Technologie de Troyes, ISTIT-CNRS FRE 2732, Equipe Modelisation et Surete des Systemes, 12, rue Marie Curie, BP 2060-10010 Troyes Cedex (France)]. E-mail: antoine.grall@utt.fr; Berenguer, C. [Universite de Technologie de Troyes, ISTIT-CNRS FRE 2732, Equipe Modelisation et Surete des Systemes, 12, rue Marie Curie, BP 2060-10010 Troyes Cedex (France)]. E-mail: christophe.berenguer@utt.fr

    2005-01-01

    This paper considers a condition-based maintenance policy for a two-unit deteriorating system. Each unit is subject to gradual deterioration and is monitored by sequential non-periodic inspections. It can be maintained by good as new preventive or corrective replacements. Every inspection or replacement entails a set-up cost and a component-specific unit cost but if actions on the two components are combined, the set-up cost is charged only once. A parametric maintenance decision framework is proposed to coordinate inspection/replacement of the two components and minimize the long-run maintenance cost of the system. A stochastic model is developed on the basis of the semi-regenerative properties of the maintained system state and the associated cost model is used to assess and optimize the performance of the maintenance model. Numerical experiments emphasize the interest of a control of the operation groupings.

  10. A PCA and ELM Based Adaptive Method for Channel Equalization in MFL Inspection

    Directory of Open Access Journals (Sweden)

    Zhenning Wu

    2014-01-01

    Full Text Available Magnetic flux leakage (MFL as an efficient method for pipeline flaw detection plays important role in pipeline safety. This nondestructive test technique assesses the health of the buried pipeline. The signal is gathered by an array of hall-effect sensors disposed at the magnetic neutral plane of a pair of permanent magnet in the pipeline inspection gauge (PIG clinging to the inner surface of the pipe wall. The magnetic flux measured by the sensors reflects the health condition of the pipe. The signal is influenced by not only the condition of the pipe, but also by the lift-off value of the sensors and various properties of electronic component. The consistency of the position of the sensors is almost never satisfied and each sensor measures differently. In this paper, a new scheme of channel equalization is proposed for MFL signal in order to correct sensor misalignments, which eventually improves accuracy of defect characterization. The algorithm proposed in this paper is adaptive to the effects of error on the disposition of the sensor due to manufacturing imperfections and movements of the sensors. The algorithm is tested by data acquired from an experimental pipeline. The results show the effectiveness of the proposed algorithm.

  11. 76 FR 65165 - Importation of Plants for Planting; Risk-Based Sampling and Inspection Approach and Propagative...

    Science.gov (United States)

    2011-10-20

    ... plant part) for or capable of propagation, including a tree, a tissue culture, a plantlet culture... articles (other than seeds, bulbs, or sterile cultures of orchid plants) from any country or locality... Animal and Plant Health Inspection Service Importation of Plants for Planting; Risk-Based Sampling...

  12. Plasma etched surface scanning inspection recipe creation based on bidirectional reflectance distribution function and polystyrene latex spheres

    Science.gov (United States)

    Saldana, Tiffany; McGarvey, Steve; Ayres, Steve

    2014-04-01

    The continual increasing demands upon Plasma Etching systems to self-clean and continue Plasma Etching with minimal downtime allows for the examination of SiCN, SiO2 and SiN defectivity based upon Surface Scanning Inspection Systems (SSIS) wafer scan results. Historically all Surface Scanning Inspection System wafer scanning recipes have been based upon Polystyrene Spheres wafer deposition for each film stack and the subsequent creation of light scattering sizing response curves. This paper explores the feasibility of the elimination of Polystyrene Latex Sphere (PSL) and/or process particle deposition on both filmed and bare Silicon wafers prior to Surface Scanning Inspection System recipe creation. The study will explore the theoretical maximal Surface Scanning Inspection System sensitivity based on PSL recipe creation in conjunction with the maximal sensitivity derived from Bidirectional Reflectance Distribution Function (BRDF) maximal sensitivity modeling recipe creation. The surface roughness (Root Mean Square) of plasma etched wafers varies dependent upon the process film stack. Decrease of the root mean square value of the wafer sample surface equates to higher surface scanning inspection system sensitivity. Maximal sensitivity SSIS scan results from bare and filmed wafers inspected with recipes created based upon Polystyrene/Particle Deposition and recipes created based upon BRDF modeling will be overlaid against each other to determine maximal sensitivity and capture rate for each type of recipe that was created with differing recipe creation modes. A statistically valid sample of defects from each Surface Scanning Inspection system recipe creation mode and each bare wafer/filmed substrate will be reviewed post SSIS System processing on a Defect Review Scanning Electron Microscope (DRSEM). Native defects, Polystyrene Latex Spheres will be collected from each statistically valid defect bin category/size. The data collected from the DRSEM will be utilized to

  13. Developing an Inspection Optimization Model Based on the Delay-Time Concept

    Directory of Open Access Journals (Sweden)

    Ehsan Nazemi

    2015-01-01

    Full Text Available Infrastructures are considered as important facilities required for every country and society to be able to work properly. Aging and deterioration of such structures during their lifetime are a major concern both for maintenance researchers in the academic world and for the practitioners. This concern is mainly because the deterioration increases the maintenance costs dramatically and lowers the reliability, availability, and safety of the structural system. Preventive maintenance and inspection activities are the most usual means for keeping the structure in a good condition. This paper utilizes the concept of delay-time for developing the optimal inspection policy for deteriorating structures. In the proposed stochastic model, discrete times of inspection activities are taken as the decision variables of an optimization problem, in a way that the obtained aperiodic (nonuniform inspection schedule minimizes the total downtime ratio of the structure. To illustrate the model capabilities, various numerical examples are solved and results are compared with the traditional periodic (uniform inspection policies. The results indicate the substantial reduction in system downtime due to the wisely planned inspection schedule and the appropriate utilization of delay-time concept, which is indeed a powerful framework for inspection optimization problems.

  14. Knowledge-based techniques in software engineering

    Energy Technology Data Exchange (ETDEWEB)

    Jairam, B.N.; Agarwal, A.; Emrich, M.L.

    1988-05-04

    Recent trends in software engineering research focus on the incorporation of AI techniques. The feasibility of an overlap between AI and software engineering is examined. The benefits of merging the two fields are highlighted. The long-term goal is to automate the software development process. Some projects being undertaken towards the attainment of this goal are presented as examples. Finally, research on the Oak Ridge Reservation aimed at developing a knowledge-based software project management aid is presented. 25 refs., 1 tab.

  15. Autonomous image localization for visual inspection of civil infrastructure

    Science.gov (United States)

    Yeum, C. M.; Choi, J.; Dyke, S. J.

    2017-03-01

    Low-cost, high-performance vision sensors in conjunction with aerial sensing platforms are providing new possibilities for achieving autonomous visual inspection in civil engineering structures. A large volume of images of a given structure can readily be collected for use in visual inspection, overcoming spatial and temporal limitations associated with human-based inspection. Although researchers have explored several algorithms and techniques for vision-based inspection in recent decades, a major challenge in past implementations lies in dealing with a high volume of images while only a small fraction of them are important for actual inspection. Because processing irrelevant images can generate a significant number of false-positives, automated visual inspection techniques should be used in coordination with methods to localize relevant regions on the images. When combined, automated visual inspection will be able to meet the objectives and quality of human visual inspection. To enable this technology, we develop and validate a novel automated image localization technique to extract regions of interest (ROIs) on each of the images before utilizing vision-based damage detection techniques. ROIs are the portions of an image that contain the physical region of the structure that is targeted for visual interrogation, denoted as the targeted region of interest (TRI). ROIs are computed based on the geometric relationship between the collected images and the TRIs. Analysis of such highly relevant and localized images would enable efficient and reliable visual inspection. We successfully demonstrate the capability of the technique to extract the ROIs using a full-scale highway sign structure in the case where weld connections serve as the TRIs.

  16. Modeling of a remote inspection system for NSSS components

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yoo Rark; Kim, Jae Hee; Lee, Jae Cheol

    2003-03-01

    Safety inspection for safety-critical unit of nuclear power plant has been processed using off-line technology. Thus we can not access safety inspection system and inspection data via network such as internet. We are making an on-line control and data access system based on WWW and JAVA technologies which can be used during plant operation to overcome these problems. Users can access inspection systems and inspection data only using web-browser. This report discusses about analysis of the existing remote system and essential techniques such as Web, JAVA, client/server model, and multi-tier model. This report also discusses about a system modeling that we have been developed using these techniques and provides solutions for developing an on-line control and data access system.

  17. Risk analysis of heat recovery steam generator with semi quantitative risk based inspection API 581

    Science.gov (United States)

    Prayogo, Galang Sandy; Haryadi, Gunawan Dwi; Ismail, Rifky; Kim, Seon Jin

    2016-04-01

    Corrosion is a major problem that most often occurs in the power plant. Heat recovery steam generator (HRSG) is an equipment that has a high risk to the power plant. The impact of corrosion damage causing HRSG power plant stops operating. Furthermore, it could be threaten the safety of employees. The Risk Based Inspection (RBI) guidelines by the American Petroleum Institute (API) 58 has been used to risk analysis in the HRSG 1. By using this methodology, the risk that caused by unexpected failure as a function of the probability and consequence of failure can be estimated. This paper presented a case study relating to the risk analysis in the HRSG, starting with a summary of the basic principles and procedures of risk assessment and applying corrosion RBI for process industries. The risk level of each HRSG equipment were analyzed: HP superheater has a medium high risk (4C), HP evaporator has a medium-high risk (4C), and the HP economizer has a medium risk (3C). The results of the risk assessment using semi-quantitative method of standard API 581 based on the existing equipment at medium risk. In the fact, there is no critical problem in the equipment components. Damage mechanisms were prominent throughout the equipment is thinning mechanism. The evaluation of the risk approach was done with the aim of reducing risk by optimizing the risk assessment activities.

  18. Automated Signal Processing Applied to Volatile-Based Inspection of Greenhouse Crops

    Directory of Open Access Journals (Sweden)

    Eldert van Henten

    2010-07-01

    Full Text Available Gas chromatograph–mass spectrometers (GC-MS have been used and shown utility for volatile-based inspection of greenhouse crops. However, a widely recognized difficulty associated with GC-MS application is the large and complex data generated by this instrument. As a consequence, experienced analysts are often required to process this data in order to determine the concentrations of the volatile organic compounds (VOCs of interest. Manual processing is time-consuming, labour intensive and may be subject to errors due to fatigue. The objective of this study was to assess whether or not GC-MS data can also be automatically processed in order to determine the concentrations of crop health associated VOCs in a greenhouse. An experimental dataset that consisted of twelve data files was processed both manually and automatically to address this question. Manual processing was based on simple peak integration while the automatic processing relied on the algorithms implemented in the MetAlignTM software package. The results of automatic processing of the experimental dataset resulted in concentrations similar to that after manual processing. These results demonstrate that GC-MS data can be automatically processed in order to accurately determine the concentrations of crop health associated VOCs in a greenhouse. When processing GC-MS data automatically, noise reduction, alignment, baseline correction and normalisation are required.

  19. Artificial Intelligence based technique for BTS placement

    Science.gov (United States)

    Alenoghena, C. O.; Emagbetere, J. O.; Aibinu, A. M.

    2013-12-01

    The increase of the base transceiver station (BTS) in most urban areas can be traced to the drive by network providers to meet demand for coverage and capacity. In traditional network planning, the final decision of BTS placement is taken by a team of radio planners, this decision is not fool proof against regulatory requirements. In this paper, an intelligent based algorithm for optimal BTS site placement has been proposed. The proposed technique takes into consideration neighbour and regulation considerations objectively while determining cell site. The application will lead to a quantitatively unbiased evaluated decision making process in BTS placement. An experimental data of a 2km by 3km territory was simulated for testing the new algorithm, results obtained show a 100% performance of the neighbour constrained algorithm in BTS placement optimization. Results on the application of GA with neighbourhood constraint indicate that the choices of location can be unbiased and optimization of facility placement for network design can be carried out.

  20. Defect inspection in hot slab surface: multi-source CCD imaging based fuzzy-rough sets method

    Science.gov (United States)

    Zhao, Liming; Zhang, Yi; Xu, Xiaodong; Xiao, Hong; Huang, Chao

    2016-09-01

    To provide an accurate surface defects inspection method and make the automation of robust image region of interests(ROI) delineation strategy a reality in production line, a multi-source CCD imaging based fuzzy-rough sets method is proposed for hot slab surface quality assessment. The applicability of the presented method and the devised system are mainly tied to the surface quality inspection for strip, billet and slab surface etcetera. In this work we take into account the complementary advantages in two common machine vision (MV) systems(line array CCD traditional scanning imaging (LS-imaging) and area array CCD laser three-dimensional (3D) scanning imaging (AL-imaging)), and through establishing the model of fuzzy-rough sets in the detection system the seeds for relative fuzzy connectedness(RFC) delineation for ROI can placed adaptively, which introduces the upper and lower approximation sets for RIO definition, and by which the boundary region can be delineated by RFC region competitive classification mechanism. For the first time, a Multi-source CCD imaging based fuzzy-rough sets strategy is attempted for CC-slab surface defects inspection that allows an automatic way of AI algorithms and powerful ROI delineation strategies to be applied to the MV inspection field.

  1. Actual extension of sinkholes: Considerations about geophysical, geomorphological, and field inspection techniques in urban planning projects in the Ebro basin (NE Spain)

    Science.gov (United States)

    Pueyo Anchuela, Ó.; Pocoví Juan, A.; Casas-Sainz, A. M.; Ansón-López, D.; Gil-Garbi, H.

    2013-05-01

    Aerial photographs, historical cartographies, and field inspection are useful tools in urban planning design on mantled karst because they permit a wide time interval to be analyzed. In the case of Zaragoza city, several works have confirmed the interest of these approaches in configuring the urban planning code and therefore represent a promising technique. Nevertheless, some caveats should be taken into account when using this kind of information. A detailed analysis is presented comparing (in a case study from the surroundings of Zaragoza) geomorphological, historical analysis, and field inspection with geophysical data. Field inspection in a noncultivated area permits the constraint of the presence of karst indicators below the geomorphological resolution of aerial photographs and shows results consistent with geophysical surveys. The studied case shows an inner zone coinciding with the sinkhole mapped from aerial photographs that correlates with changes in the position of the substratum and changes in thickness of alluvial sediments. The integrated analysis permits us to define an external subsidence ring around the geomorphological sinkhole whose surface is twice the size of the inner zone. This outer ring is indicated by geometrical changes in GPR profiles, increases of thickness of the conductive shallower unit toward the collapse, and small collapses on marginal cracks. These results support the higher extension of karst hazards linked to sinkholes with respect to their geomorphological expression and the needed detailed analysis to constrain the real sinkhole size or the use of security radii surrounding this surficial evidence when geomorphological data is used for the hazard analyses or the urban planning at karstic zones.

  2. Consideration of arrayed $e$-beam microcolumn based systems potentialities for wafer defects inspection

    CERN Document Server

    Kazmiruk, V V

    2008-01-01

    The $e$-beam column which is intended on defects inspection is considered. The defects which are to be examined or potentially might be examined at inspection stage are briefly considered. Interrelations between the system parameters is ascertaining and the ways of optimization and the technical requirements to the system in whole are discussed. As a result, we find the optimal combinations of the system parameters for the purpose.

  3. A portable nondestructive real-time detection system for inspection of pork quality attributes using Vis/NIR spectral technique

    Science.gov (United States)

    Sun, Hongwei; Peng, Yankun

    2016-05-01

    There are many preferences expressing the quality of pork: color, pH, especially TVB-N content. Different quality pork has different spectral feature (in range of 400 to 1000nm). To detect quality attributes of pork easily, real-time, nondestructively, a portable device based on Vis/NIR spectral technique was developed. The device is mainly made up of four units: light source, spectrometer, controller and display screen. After hardware platform established, reflectance spectra of 44 samples were collected from this system. And their physicochemical characteristics such as color parameters, pH value and the content of total volatile basic-nitrogen (TVB-N) were measured in standard methods. Spectrum data acquired were processed by Savitzky-Golay filter(S-G) for noise removal, and then operated by standard normal variable transformation (SNV) for baseline drifts relieving. The partial least squares regression (PLSR) was used to build prediction models for L*, a*, b* pH* and TVB-N content, which could gain good prediction results with Rp of 0.92, 0.91, 0.92, 0.95 and 0.96 respectively. The results demonstrated that this device could be a promising tool applied to detecting pork quality attributes portably, real-time and nondestructively.

  4. Intelligent Foreign Particle Inspection Machine for Injection Liquid Examination Based on Modified Pulse-Coupled Neural Networks

    Science.gov (United States)

    Ge, Ji; Wang, YaoNan; Zhou, BoWen; Zhang, Hui

    2009-01-01

    A biologically inspired spiking neural network model, called pulse-coupled neural networks (PCNN), has been applied in an automatic inspection machine to detect visible foreign particles intermingled in glucose or sodium chloride injection liquids. Proper mechanisms and improved spin/stop techniques are proposed to avoid the appearance of air bubbles, which increases the algorithms' complexity. Modified PCNN is adopted to segment the difference images, judging the existence of foreign particles according to the continuity and smoothness properties of their moving traces. Preliminarily experimental results indicate that the inspection machine can detect the visible foreign particles effectively and the detection speed, accuracy and correct detection rate also satisfying the needs of medicine preparation. PMID:22412318

  5. Mode Conversion Behavior of Guided Wave in a Pipe Inspection System Based on a Long Waveguide

    Directory of Open Access Journals (Sweden)

    Feiran Sun

    2016-10-01

    Full Text Available To make clear the mode conversion behavior of S0-mode lamb wave and SH0-plate wave converting to the longitudinal mode guided wave and torsional mode guided wave in a pipe, respectively, the experiments were performed based on a previous built pipe inspection system. The pipe was wound with an L-shaped plate or a T-shaped plate as the waveguide, and the S0-wave and SH0-wave were excited separately in the waveguide. To carry out the objective, a meander-line coil electromagnetic acoustic transducer (EMAT for S0-wave and a periodic permanent magnet (PPM EMAT for SH0-wave were developed and optimized. Then, several comparison experiments were conducted to compare the efficiency of mode conversion. Experimental results showed that the T(0,1 mode, L(0,1 mode, and L(0,2 mode guided waves can be successfully detected when converted from the S0-wave or SH0-wave with different shaped waveguides. It can also be inferred that the S0-wave has a better ability to convert to the T(0,1 mode, while the SH0-wave is easier to convert to the L(0,1 mode and L(0,2 mode, and the L-shaped waveguide has a better efficiency than T-shaped waveguide.

  6. Mode Conversion Behavior of Guided Wave in a Pipe Inspection System Based on a Long Waveguide.

    Science.gov (United States)

    Sun, Feiran; Sun, Zhenguo; Chen, Qiang; Murayama, Riichi; Nishino, Hideo

    2016-10-19

    To make clear the mode conversion behavior of S0-mode lamb wave and SH0-plate wave converting to the longitudinal mode guided wave and torsional mode guided wave in a pipe, respectively, the experiments were performed based on a previous built pipe inspection system. The pipe was wound with an L-shaped plate or a T-shaped plate as the waveguide, and the S0-wave and SH0-wave were excited separately in the waveguide. To carry out the objective, a meander-line coil electromagnetic acoustic transducer (EMAT) for S0-wave and a periodic permanent magnet (PPM) EMAT for SH0-wave were developed and optimized. Then, several comparison experiments were conducted to compare the efficiency of mode conversion. Experimental results showed that the T(0,1) mode, L(0,1) mode, and L(0,2) mode guided waves can be successfully detected when converted from the S0-wave or SH0-wave with different shaped waveguides. It can also be inferred that the S0-wave has a better ability to convert to the T(0,1) mode, while the SH0-wave is easier to convert to the L(0,1) mode and L(0,2) mode, and the L-shaped waveguide has a better efficiency than T-shaped waveguide.

  7. A novel defect depth measurement method based on Nonlinear System Identification for pulsed thermographic inspection

    Science.gov (United States)

    Zhao, Yifan; Mehnen, Jörn; Sirikham, Adisorn; Roy, Rajkumar

    2017-02-01

    This paper introduces a new method to improve the reliability and confidence level of defect depth measurement based on pulsed thermographic inspection by addressing the over-fitting problem. Different with existing methods using a fixed model structure for all pixels, the proposed method adaptively detects the optimal model structure for each pixel thus targeting to achieve better model fitting while using less model terms. Results from numerical simulations and real experiments suggest that (a) the new method is able to measure defect depth more accurately without a pre-set model structure (error is usually within 1 % when SNR>32 dB) in comparison with existing methods, (b) the number of model terms should be 8 for signals with SNR∈ [ 30 dB , 40 dB ] , 8-10 for SNR>40 dB and 5-8 for SNR<30 dB, and (c) a data length with at least 100 data points and 2-3 times of the characteristic time usually produces the best results.

  8. Risk reduction in dimension inspection of the plastic injection-molded parts from mechatronic devices by using optical 3D measuring techniques

    Directory of Open Access Journals (Sweden)

    Braga Ion Cristian

    2017-01-01

    Full Text Available As of the definition presented by Harashima, Tomizuka, and Fukada in 1996, the mechatronics is the synergistic combination of precision mechanical engineering, electronic control and systems thinking in the design of products and manufacturing processes. The most of the mechatronic devices need the precise dimensions of the plastic parts, as long as the combination of those parts leads to a final haptic characteristic defined within specific limits or when the certain travel way is linked with an electrical contact. The increasing of the risks to produce bad mechatronic devices are directly related to the combination of the plastic injectionmolded parts out of different cavities. The paper’s aim is to present reducing of the risks to have bad final parts assembled with the components out of plastic injection-molded parts by using optical 3D measuring techniques at first validation of the parts out of the tool and setting parameters in the injection machines. The shrinkage and the warpage are more easily detected in that way and this will support first article inspection, but also during the entire production process. A case study presents the analysis of the data coming from the measurements of the plastic parts from each cavity and the combination of those parts, by using the ATOS inspection software. The CAD data are compared with the measured ones and the differences will be visible in the colored plotted areas, also the differences of the parts out of distinct cavities will be also displayed by overlaying of the measurements.

  9. Three-axis magnetic flux leakage in-line inspection simulation based on finite-element analysis

    Institute of Scientific and Technical Information of China (English)

    Feng Jian; Zhang Jun-Feng; Lu Sen-Xiang; Wang Hong-Yang; Ma Rui-Ze

    2013-01-01

    With the increase of pipelines,corrosion leakage accidents happen frequently.Therefore,nondestructive testing technology is important for ensuring the safe operation of the pipelines and energy mining.In this paper,the structure and principle of magnetic flux leakage (MFL) in-line inspection system is introduced first.Besides,a mathematic model of the system according to the ampere circuit rule,flux continuity theorem,and column coordinate transform is built,and the magnetic flux density in every point of space is calculated based on the theory of finite element analysis.Then we analyze and design the disposition of measurement section probes and sensors combining both three-axis MFL in-line inspection and multi-sensor fusion technology.Its advantage is that the three-axis changes of magnetic flux leakage field are measured by the multi-probes at the same time,so we can determine various defects accurately.Finally,the theory of finite element analysis is used to build a finite element simulation model,and the relationship between defects and MFL inspection signals is studied.Simulation and experiment results verify that the method not only enhances the detection ability to different types of defects but also improves the precision and reliability of the inspection system.

  10. Deposition uniformity inspection in IC wafer surface

    Science.gov (United States)

    Li, W. C.; Lin, Y. T.; Jeng, J. J.; Chang, C. L.

    2014-03-01

    This paper focuses on the task of automatic visual inspection of color uniformity on the surface of integrated circuits (IC) wafers arising from the layering process. The oxide thickness uniformity within a given wafer with a desired target thickness is of great importance for modern semiconductor circuits with small oxide thickness. The non-uniform chemical vapor deposition (CVD) on a wafer surface will proceed to fail testing in Wafer Acceptance Test (WAT). Early detection of non-uniform deposition in a wafer surface can reduce material waste and improve production yields. The fastest and most low-priced inspection method is a machine vision-based inspection system. In this paper, the proposed visual inspection system is based on the color representations which were reflected from wafer surface. The regions of non-uniform deposition present different colors from the uniform background in a wafer surface. The proposed inspection technique first learns the color data via color space transformation from uniform deposition of normal wafer surfaces. The individual small region statistical comparison scheme then proceeds to the testing wafers. Experimental results show that the proposed method can effectively detect the non-uniform deposition regions on the wafer surface. The inspection time of the deposited wafers is quite compatible with the atmospheric pressure CVD time.

  11. Inspection with non destructive assay techniques of the aluminium coating of the TRIGA Mark III reactor vat; Inspeccion con tecnicas de ensayos no destructivos del recubrimiento de aluminio de la tina del reactor TRIGA Mark III

    Energy Technology Data Exchange (ETDEWEB)

    Reyes A, A.I.; Gonzalez M, A.; Castaneda J, G.; Rivera M, H.; Sandoval G, I. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2001-07-01

    In June 2000, the Reactor Department assigned to the Scientific Research Direction of the National Institute of Nuclear Research requested to the Non-destructive Assays Laboratory (LEND), assigned to the Materials Science Management, the inspection and measurement of thickness of the aluminium coating (liner) of the TRIGA Mark III reactor vat with non-destructive assay techniques, due to that the aluminium coating is exposed mainly to undergo slimming on its back side due to corrosion phenomena. Activity that was able to be carried out from april until august 2001. It is worth pointing out that this type of inspection with these techniques was realized by first time. The non-destructive assays (NDA) are techniques which use indirect physical methods for inspecting the sanitation of components in process or in service, for detect lack of continuity or defects which affect their quality or usefulness. The application of those do not alter the physical, chemical, mechanical or dimensional properties of the part subject of inspection. The results of the application of the ultrasound inspection techniques, industrial radiography and penetrating liquids are presented. (Author)

  12. Decision making for stable inspection planning of deteriorating structures based on constraint reliability and uncertainties

    Directory of Open Access Journals (Sweden)

    Jalal alsarraf

    2014-06-01

    Full Text Available Life-time cost minimization is considered as the optimal criterion for planning of inspection, repair and maintenance of structures. However, most of the probabilities and the cost items related to the cost analysis generally contain inevitable uncertainties in actual cases. The appropriateness of inspection planning may be lost by several errors induced by such uncertainties. In this study, a cost minimization method with the constraint of reliability is developed in order to obtain stable inspection planning against the estimation errors of the parameters. In the analysis, the life-time cost optimization is carried out under the constraint that the failure probabilities of the members are controlled below the respective target values allowed for the members. First, initial target failure probabilities are assumed for each member. Then, the robustness of the inspection planning is investigated by adjusting the parameters within the range of uncertainties. The initial values of the target failure probabilities are altered until an acceptable result is obtained. The applicability of the proposed method is examined for a structure with several uncertain parameters. A sequential cost minimization method is employed to optimize the life-time cost. It is made clear that by using this approach, the stability of the life-time cost is maintained without losing the benefit of the cost minimization method. Keywords: Crack, Fatigue, Inspection, Numerical Model, Reliability, Structure.

  13. Research on Zonal Inspection Intervals of Civil Aircraft Based on Improved FAHP

    Directory of Open Access Journals (Sweden)

    Lu Xiang

    2013-07-01

    Full Text Available One of the most important things in formulating aircraft maintenance program is to determine the zonal inspection intervals. In accordance with the current situation that there has no perfect rating systems of zonal inspection under MSG-3 (Maintenance Steering Group-3 analysis system, a method to calculate the integrate level of zonal rating is to analyze the impact of aircraft zonal rating factors, establish a hierarchical index evaluation system and then utilize the improved fuzzy analytic hierarchy process (FAHP to determine the indexes’ weight. Moreover, the zonal inspection intervals can be established according to the correspondence between rates and intervals. Finally, take a typical zone of an aircraft as an example to verify the method.  

  14. Inspection Robot Based Mobile Sensing and Power Line Tracking for Smart Grid.

    Science.gov (United States)

    Byambasuren, Bat-Erdene; Kim, Donghan; Oyun-Erdene, Mandakh; Bold, Chinguun; Yura, Jargalbaatar

    2016-02-19

    Smart sensing and power line tracking is very important in a smart grid system. Illegal electricity usage can be detected by remote current measurement on overhead power lines using an inspection robot. There is a need for accurate detection methods of illegal electricity usage. Stable and correct power line tracking is a very prominent issue. In order to correctly track and make accurate measurements, the swing path of a power line should be previously fitted and predicted by a mathematical function using an inspection robot. After this, the remote inspection robot can follow the power line and measure the current. This paper presents a new power line tracking method using parabolic and circle fitting algorithms for illegal electricity detection. We demonstrate the effectiveness of the proposed tracking method by simulation and experimental results.

  15. Quantitative Inspection of Remanence of Broken Wire Rope Based on Compressed Sensing

    Directory of Open Access Journals (Sweden)

    Juwei Zhang

    2016-08-01

    Full Text Available Most traditional strong magnetic inspection equipment has disadvantages such as big excitation devices, high weight, low detection precision, and inconvenient operation. This paper presents the design of a giant magneto-resistance (GMR sensor array collection system. The remanence signal is collected to acquire two-dimensional magnetic flux leakage (MFL data on the surface of wire ropes. Through the use of compressed sensing wavelet filtering (CSWF, the image expression of wire ropes MFL on the surface was obtained. Then this was taken as the input of the designed back propagation (BP neural network to extract three kinds of MFL image geometry features and seven invariant moments of defect images. Good results were obtained. The experimental results show that nondestructive inspection through the use of remanence has higher accuracy and reliability compared with traditional inspection devices, along with smaller volume, lighter weight and higher precision.

  16. Inspection Robot Based Mobile Sensing and Power Line Tracking for Smart Grid

    Directory of Open Access Journals (Sweden)

    Bat-erdene Byambasuren

    2016-02-01

    Full Text Available Smart sensing and power line tracking is very important in a smart grid system. Illegal electricity usage can be detected by remote current measurement on overhead power lines using an inspection robot. There is a need for accurate detection methods of illegal electricity usage. Stable and correct power line tracking is a very prominent issue. In order to correctly track and make accurate measurements, the swing path of a power line should be previously fitted and predicted by a mathematical function using an inspection robot. After this, the remote inspection robot can follow the power line and measure the current. This paper presents a new power line tracking method using parabolic and circle fitting algorithms for illegal electricity detection. We demonstrate the effectiveness of the proposed tracking method by simulation and experimental results.

  17. Model Based Ceramic tile inspection using Discrete Wavelet Transform and Euclidean Distance

    CERN Document Server

    Elmougy, Samir; El-Azab, Ahmed

    2010-01-01

    Visual inspection of industrial products is used to determine the control quality for these products. This paper deals with the problem of visual inspection of ceramic tiles industry using Wavelet Transform. The third level the coefficients of two dimensions Haar Discrete Wavelet Transform (HDWT) is used in this paper to process the images and feature extraction. The proposed algorithm consists of two main phases. The first phase is to compute the wavelet transform for an image free of defects which known as reference image, and the image to be inspected which known as test image. The second phase is used to decide whether the tested image is defected or not using the Euclidean distance similarity measure. The experimentation results of the proposed algorithm give 97% for correct detection of ceramic defects.

  18. Quantitative Inspection of Remanence of Broken Wire Rope Based on Compressed Sensing

    Science.gov (United States)

    Zhang, Juwei; Tan, Xiaojiang

    2016-01-01

    Most traditional strong magnetic inspection equipment has disadvantages such as big excitation devices, high weight, low detection precision, and inconvenient operation. This paper presents the design of a giant magneto-resistance (GMR) sensor array collection system. The remanence signal is collected to acquire two-dimensional magnetic flux leakage (MFL) data on the surface of wire ropes. Through the use of compressed sensing wavelet filtering (CSWF), the image expression of wire ropes MFL on the surface was obtained. Then this was taken as the input of the designed back propagation (BP) neural network to extract three kinds of MFL image geometry features and seven invariant moments of defect images. Good results were obtained. The experimental results show that nondestructive inspection through the use of remanence has higher accuracy and reliability compared with traditional inspection devices, along with smaller volume, lighter weight and higher precision. PMID:27571077

  19. Non-Destructive Techniques Based on Eddy Current Testing

    Directory of Open Access Journals (Sweden)

    Ernesto Vázquez-Sánchez

    2011-02-01

    Full Text Available Non-destructive techniques are used widely in the metal industry in order to control the quality of materials. Eddy current testing is one of the most extensively used non-destructive techniques for inspecting electrically conductive materials at very high speeds that does not require any contact between the test piece and the sensor. This paper includes an overview of the fundamentals and main variables of eddy current testing. It also describes the state-of-the-art sensors and modern techniques such as multi-frequency and pulsed systems. Recent advances in complex models towards solving crack-sensor interaction, developments in instrumentation due to advances in electronic devices, and the evolution of data processing suggest that eddy current testing systems will be increasingly used in the future.

  20. Non-destructive techniques based on eddy current testing.

    Science.gov (United States)

    García-Martín, Javier; Gómez-Gil, Jaime; Vázquez-Sánchez, Ernesto

    2011-01-01

    Non-destructive techniques are used widely in the metal industry in order to control the quality of materials. Eddy current testing is one of the most extensively used non-destructive techniques for inspecting electrically conductive materials at very high speeds that does not require any contact between the test piece and the sensor. This paper includes an overview of the fundamentals and main variables of eddy current testing. It also describes the state-of-the-art sensors and modern techniques such as multi-frequency and pulsed systems. Recent advances in complex models towards solving crack-sensor interaction, developments in instrumentation due to advances in electronic devices, and the evolution of data processing suggest that eddy current testing systems will be increasingly used in the future.

  1. Non-Destructive Techniques Based on Eddy Current Testing

    Science.gov (United States)

    García-Martín, Javier; Gómez-Gil, Jaime; Vázquez-Sánchez, Ernesto

    2011-01-01

    Non-destructive techniques are used widely in the metal industry in order to control the quality of materials. Eddy current testing is one of the most extensively used non-destructive techniques for inspecting electrically conductive materials at very high speeds that does not require any contact between the test piece and the sensor. This paper includes an overview of the fundamentals and main variables of eddy current testing. It also describes the state-of-the-art sensors and modern techniques such as multi-frequency and pulsed systems. Recent advances in complex models towards solving crack-sensor interaction, developments in instrumentation due to advances in electronic devices, and the evolution of data processing suggest that eddy current testing systems will be increasingly used in the future. PMID:22163754

  2. Cervical screening by visual inspection, HPV testing, liquid-based and conventional cytology in Amazonian Peru.

    Science.gov (United States)

    Almonte, Maribel; Ferreccio, Catterina; Winkler, Jennifer L; Cuzick, Jack; Tsu, Vivien; Robles, Sylvia; Takahashi, Rina; Sasieni, Peter

    2007-08-15

    Cervical cancer is an important public health problem in many developing countries, where cytology screening has been ineffective. We compared four tests to identify the most appropriate for screening in countries with limited resources. Nineteen midwives screened 5,435 women with visual inspection (VIA) and collected cervical samples for HPV testing, liquid-based cytology (LBC) and conventional cytology (CC). If VIA was positive, a doctor performed magnified VIA. CC was read locally, LBC was read in Lima and HPV testing was done in London. Women with a positive screening test were offered colposcopy or cryotherapy (with biopsy). Inadequacy rates were 5% and 11% for LBC and CC respectively, and less than 0.1% for VIA and HPV. One thousand eight hundred eighty-one women (84% of 2,236) accepted colposcopy/cryotherapy: 79 had carcinoma in situ or cancer (CIS+), 27 had severe- and 42 moderate-dysplasia on histology. We estimated a further 6.5 cases of CIS+ in women without a biopsy. Sensitivity for CIS+ (specificity for less than moderate dysplasia) was 41.2% (76.7%) for VIA, 95.8% (89.3%) for HPV, 80.3% (83.7%) for LBC, and 42.5% (98.7%) for CC. Sensitivities for moderate dysplasia or worse were better for VIA (54.9%) and less favourable for HPV and cytology. In this setting, VIA and CC missed the majority of high-grade disease. Overall, HPV testing performed best. VIA gives immediate results, but will require investment in regular training and supervision. Further work is needed to determine whether screened-positive women should all be treated or triaged with a more specific test.

  3. Camber Angle Inspection for Vehicle Wheel Alignments

    Science.gov (United States)

    Young, Jieh-Shian; Hsu, Hong-Yi; Chuang, Chih-Yuan

    2017-01-01

    This paper introduces an alternative approach to the camber angle measurement for vehicle wheel alignment. Instead of current commercial approaches that apply computation vision techniques, this study aims at realizing a micro-control-unit (MCU)-based camber inspection system with a 3-axis accelerometer. We analyze the precision of the inspection system for the axis misalignments of the accelerometer. The results show that the axes of the accelerometer can be aligned to the axes of the camber inspection system imperfectly. The calibrations that can amend these axis misalignments between the camber inspection system and the accelerometer are also originally proposed since misalignments will usually happen in fabrications of the inspection systems. During camber angle measurements, the x-axis or z-axis of the camber inspection system and the wheel need not be perfectly aligned in the proposed approach. We accomplished two typical authentic camber angle measurements. The results show that the proposed approach is applicable with a precision of ±0.015∘ and therefore facilitates the camber measurement process without downgrading the precision by employing an appropriate 3-axis accelerometer. In addition, the measured results of camber angles can be transmitted via the medium such as RS232, Bluetooth, and Wi-Fi. PMID:28165365

  4. Camber Angle Inspection for Vehicle Wheel Alignments

    Directory of Open Access Journals (Sweden)

    Jieh-Shian Young

    2017-02-01

    Full Text Available This paper introduces an alternative approach to the camber angle measurement for vehicle wheel alignment. Instead of current commercial approaches that apply computation vision techniques, this study aims at realizing a micro-control-unit (MCU-based camber inspection system with a 3-axis accelerometer. We analyze the precision of the inspection system for the axis misalignments of the accelerometer. The results show that the axes of the accelerometer can be aligned to the axes of the camber inspection system imperfectly. The calibrations that can amend these axis misalignments between the camber inspection system and the accelerometer are also originally proposed since misalignments will usually happen in fabrications of the inspection systems. During camber angle measurements, the x-axis or z-axis of the camber inspection system and the wheel need not be perfectly aligned in the proposed approach. We accomplished two typical authentic camber angle measurements. The results show that the proposed approach is applicable with a precision of ± 0.015 ∘ and therefore facilitates the camber measurement process without downgrading the precision by employing an appropriate 3-axis accelerometer. In addition, the measured results of camber angles can be transmitted via the medium such as RS232, Bluetooth, and Wi-Fi.

  5. User interface inspection methods a user-centered design method

    CERN Document Server

    Wilson, Chauncey

    2014-01-01

    User Interface Inspection Methods succinctly covers five inspection methods: heuristic evaluation, perspective-based user interface inspection, cognitive walkthrough, pluralistic walkthrough, and formal usability inspections. Heuristic evaluation is perhaps the best-known inspection method, requiring a group of evaluators to review a product against a set of general principles. The perspective-based user interface inspection is based on the principle that different perspectives will find different problems in a user interface. In the related persona-based inspection, colleagues assume the

  6. A risk-based approach to maintenance planning utilizing in-line inspection data

    Energy Technology Data Exchange (ETDEWEB)

    Fenyvesi, L.L. [TransCanada PipeLines Ltd., Calgary, AB (Canada); Colquhoun, I.; Kania, R.; Gu, B. [GE Power Systems (Canada)

    2004-07-01

    The pipeline industry routinely performs in-line inspections (ILI) to manage external corrosion in pipelines. ILIs are followed by repairs of defects that fail a deterministic criterion. Re-inspection is then performed after a prescribed time interval has elapsed. However, due to uncertainties associated with magnetic flux leakage (MFL) defect sizing and corrosion growth rates, a deterministic repair and re-inspection may result in nonessential maintenance expenditure. In addition, critical features may sometimes remain unidentified. This paper suggested that in order to evaluate the sensitivity of a defect's failure probability more effectively, a better approach would be to evaluate corrosion defects by viewing the process as an analysis of a set of stochastic variables rather than deterministic values. Therefore, this paper outlined the proposed stochastic approach in which tool error and growth rate uncertainty were explicitly considered. Computer simulation was used along with a process for continuously improving the characterization of each variable through a feedback loop. In order to minimize analysis time, the paper also outlined alternative methods to Monte Carlo, such as Importance Sampling. The approach has been successfully applied in field situations. It was shown that the approach can incorporate new information through repeat inspections or field excavations. 6 refs., 10 figs.

  7. Identification of seagrasses in the gut of a marine herbivorous fish using DNA barcoding and visual inspection techniques.

    Science.gov (United States)

    Chelsky Budarf, A; Burfeind, D D; Loh, W K W; Tibbetts, I R

    2011-07-01

    Traditional visual diet analysis techniques were compared with DNA barcoding in juvenile herbivorous rabbitfish Siganus fuscescens collected in Moreton Bay, Australia, where at least six species of seagrass occur. The intergenic spacer trnH-psbA, suggested as the optimal gene for barcoding angiosperms, was used for the first time to identify the seagrass in fish guts. Four seagrass species and one alga were identified visually from gut contents; however, there was considerable uncertainty in visual identification with 38 of 40 fish having unidentifiable plant fragments in their gut. PCR and single-strand conformational polymorphism (SSCP) were able to discriminate three seagrass families from visually cryptic gut contents. While effective in identifying cryptic gut content to family level, this novel method is likely to be most efficient when paired with visual identification techniques.

  8. Comparative study of Palito inspection and MFL Inspection

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Anne A. de; Miranda, Ivan Vicente Janvrot; Silva, Jose Augusto Pereira da [Pipeway Engenharia, Rio de Janeiro, RJ (Brazil); Guimaraes, Frederico S.; Magalhaes, Joao Alfredo P. [Minds at Work, Rio de Janeiro, RJ (Brazil); Sabino, Joao Marcos [Petroleo Brasileiro S.A. (PETROBRAS/UN-RN/CE), Natal, RN (Brazil). Unidade de Negocios Rio Grande do Norte e Ceara

    2009-07-01

    A 16 inches oil pipeline was surveyed with MFL and Palito pig in 2007. The MFL inspection was performed by Pipeway Engenharia while Palito inspection was performed by PETROBRAS. A comparison between the results of these two ILI inspections has been made to validate Palito Pig and to assess main characteristics and differences between the two techniques. The purpose of this paper is to detail the methodology applied to perform the comparison and to present a comparative study of results registered in the MFL and Palito inspections by Pipeway Engenharia, PETROBRAS/CENPES and CPTI/PUC-Rio. (author)

  9. Hospital Inspections

    Data.gov (United States)

    U.S. Department of Health & Human Services — Welcome to hospitalinspections.org, a website run by the Association of Health Care Journalists (AHCJ) that aims to make federal hospital inspection reports easier...

  10. Dynamics-based Nondestructive Structural Monitoring Techniques

    Science.gov (United States)

    2012-06-21

    in the practice of non- destructive evaluation ( NDE ) and structural health monitoring (SHM). Guided wave techniques have several advantages over...conventional bulk wave ultrasonic NDE /SHM techniques. Some of these advantages are outlined in Table I. However, in addition to the advantages of...PVDF transducers for SHM applications with controlled guided wave modes and frequencies [7]. Wilcox used EMATs with circular coils in a guided wave

  11. DCT-based cyber defense techniques

    Science.gov (United States)

    Amsalem, Yaron; Puzanov, Anton; Bedinerman, Anton; Kutcher, Maxim; Hadar, Ofer

    2015-09-01

    With the increasing popularity of video streaming services and multimedia sharing via social networks, there is a need to protect the multimedia from malicious use. An attacker may use steganography and watermarking techniques to embed malicious content, in order to attack the end user. Most of the attack algorithms are robust to basic image processing techniques such as filtering, compression, noise addition, etc. Hence, in this article two novel, real-time, defense techniques are proposed: Smart threshold and anomaly correction. Both techniques operate at the DCT domain, and are applicable for JPEG images and H.264 I-Frames. The defense performance was evaluated against a highly robust attack, and the perceptual quality degradation was measured by the well-known PSNR and SSIM quality assessment metrics. A set of defense techniques is suggested for improving the defense efficiency. For the most aggressive attack configuration, the combination of all the defense techniques results in 80% protection against cyber-attacks with PSNR of 25.74 db.

  12. Developing an Inspection Optimization Model Based on the Delay-Time Concept

    OpenAIRE

    Ehsan Nazemi; Kamran Shahanaghi

    2015-01-01

    Infrastructures are considered as important facilities required for every country and society to be able to work properly. Aging and deterioration of such structures during their lifetime are a major concern both for maintenance researchers in the academic world and for the practitioners. This concern is mainly because the deterioration increases the maintenance costs dramatically and lowers the reliability, availability, and safety of the structural system. Preventive maintenance and inspect...

  13. Research on Defects Inspection of Solder Balls Based on Eddy Current Pulsed Thermography

    Science.gov (United States)

    Zhou, Xiuyun; Zhou, Jinlong; Tian, Guiyun; Wang, Yizhe

    2015-01-01

    In order to solve tiny defect detection for solder balls in high-density flip-chip, this paper proposed feasibility study on the effect of detectability as well as classification based on eddy current pulsed thermography (ECPT). Specifically, numerical analysis of 3D finite element inductive heat model is generated to investigate disturbance on the temperature field for different kind of defects such as cracks, voids, etc. The temperature variation between defective and non-defective solder balls is monitored for defects identification and classification. Finally, experimental study is carried on the diameter 1mm tiny solder balls by using ECPT and verify the efficacy of the technique. PMID:26473871

  14. Differential Laser Doppler based Non-Contact Sensor for Dimensional Inspection with Error Propagation Evaluation

    Directory of Open Access Journals (Sweden)

    Ketsaya Vacharanukul

    2006-06-01

    Full Text Available To achieve dynamic error compensation in CNC machine tools, a non-contactlaser probe capable of dimensional measurement of a workpiece while it is being machinedhas been developed and presented in this paper. The measurements are automatically fedback to the machine controller for intelligent error compensations. Based on a well resolvedlaser Doppler technique and real time data acquisition, the probe delivers a very promisingdimensional accuracy at few microns over a range of 100 mm. The developed opticalmeasuring apparatus employs a differential laser Doppler arrangement allowing acquisitionof information from the workpiece surface. In addition, the measurements are traceable tostandards of frequency allowing higher precision.

  15. Research on defects inspection of solder balls based on eddy current pulsed thermography.

    Science.gov (United States)

    Zhou, Xiuyun; Zhou, Jinlong; Tian, Guiyun; Wang, Yizhe

    2015-10-13

    In order to solve tiny defect detection for solder balls in high-density flip-chip, this paper proposed feasibility study on the effect of detectability as well as classification based on eddy current pulsed thermography (ECPT). Specifically, numerical analysis of 3D finite element inductive heat model is generated to investigate disturbance on the temperature field for different kind of defects such as cracks, voids, etc. The temperature variation between defective and non-defective solder balls is monitored for defects identification and classification. Finally, experimental study is carried on the diameter 1mm tiny solder balls by using ECPT and verify the efficacy of the technique.

  16. Research on Defects Inspection of Solder Balls Based on Eddy Current Pulsed Thermography

    Directory of Open Access Journals (Sweden)

    Xiuyun Zhou

    2015-10-01

    Full Text Available In order to solve tiny defect detection for solder balls in high-density flip-chip, this paper proposed feasibility study on the effect of detectability as well as classification based on eddy current pulsed thermography (ECPT. Specifically, numerical analysis of 3D finite element inductive heat model is generated to investigate disturbance on the temperature field for different kind of defects such as cracks, voids, etc. The temperature variation between defective and non-defective solder balls is monitored for defects identification and classification. Finally, experimental study is carried on the diameter 1mm tiny solder balls by using ECPT and verify the efficacy of the technique.

  17. A Comparative Study of Three Vibration Based Damage Assessment Techniques

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Rytter, A.

    Three different vibration based damage assessment techniques have been compared. One of the techniques uses the ratios between changes in experimentally and theoretically estimated natural frequencies, respectively, to locate a damage. The second technique relies on updating of an FEM based...

  18. Flood alert system based on bayesian techniques

    Science.gov (United States)

    Gulliver, Z.; Herrero, J.; Viesca, C.; Polo, M. J.

    2012-04-01

    The problem of floods in the Mediterranean regions is closely linked to the occurrence of torrential storms in dry regions, where even the water supply relies on adequate water management. Like other Mediterranean basins in Southern Spain, the Guadalhorce River Basin is a medium sized watershed (3856 km2) where recurrent yearly floods occur , mainly in autumn and spring periods, driven by cold front phenomena. The torrential character of the precipitation in such small basins, with a concentration time of less than 12 hours, produces flash flood events with catastrophic effects over the city of Malaga (600000 inhabitants). From this fact arises the need for specific alert tools which can forecast these kinds of phenomena. Bayesian networks (BN) have been emerging in the last decade as a very useful and reliable computational tool for water resources and for the decision making process. The joint use of Artificial Neural Networks (ANN) and BN have served us to recognize and simulate the two different types of hydrological behaviour in the basin: natural and regulated. This led to the establishment of causal relationships between precipitation, discharge from upstream reservoirs, and water levels at a gauging station. It was seen that a recurrent ANN model working at an hourly scale, considering daily precipitation and the two previous hourly values of reservoir discharge and water level, could provide R2 values of 0.86. BN's results slightly improve this fit, but contribute with uncertainty to the prediction. In our current work to Design a Weather Warning Service based on Bayesian techniques the first steps were carried out through an analysis of the correlations between the water level and rainfall at certain representative points in the basin, along with the upstream reservoir discharge. The lower correlation found between precipitation and water level emphasizes the highly regulated condition of the stream. The autocorrelations of the variables were also

  19. Model-based compressive sensing for damage localization in Lamb wave inspection.

    Science.gov (United States)

    Perelli, Alessandro; Di Ianni, Tommaso; Marzani, Alessandro; De Marchi, Luca; Masetti, Guido

    2013-10-01

    Compressive sensing (CS) has emerged as a potentially viable technique for the efficient compression and analysis of high-resolution signals that have a sparse representation in a fixed basis. In this work, we have developed a CS approach for ultrasonic signal decomposition suitable to achieve high performance in Lamb-wave-based defect detection procedures. In the proposed approach, a CS algorithm based on an alternating minimization (AM) procedure is adopted to extract the information about both the system impulse response and the reflectivity function. The implemented tool exploits the dispersion compensation properties of the warped frequency transform as a means to generate the sparsifying basis for the signal representation. The effectiveness of the decomposition task is demonstrated on synthetic signals and successfully tested on experimental Lamb waves propagating in an aluminum plate. Compared with available strategies, the proposed approach provides an improvement in the accuracy of wave propagation path length estimation, a fundamental step in defect localization procedures.

  20. Correlation-based imaging technique using ultrasonic transmit-receive array for Non-Destructive Evaluation.

    Science.gov (United States)

    Quaegebeur, Nicolas; Masson, Patrice

    2012-12-01

    This paper describes a novel array post-processing method for Non-Destructive Evaluation (NDE) using phased-array ultrasonic probes. The approach uses the capture and processing of the full matrix of all transmit-receive time-domain signals from a transducer array as in the case of the Total Focusing Method (TFM), referred as the standard of imaging algorithms. The proposed technique is based on correlation of measured signals with theoretical propagated signals computed over a given grid of points. In that case, real-time imaging can be simply implemented using discrete signal product. The advantage of the present technique is to take into account transducer directivity, dynamics and complex propagation patterns, such that the number of required array elements for a given imaging performance can be greatly reduced. Numerical and experimental application to contact inspection of isotropic structure is presented and real-time implementation issues are discussed.

  1. Positioning challenges in reconfigurable semi-autonomous robotic NDE inspection

    Science.gov (United States)

    Pierce, S. Gareth; Dobie, Gordon; Summan, Rahul; Mackenzie, Liam; Hensman, James; Worden, Keith; Hayward, Gordon

    2010-03-01

    This paper describes work conducted into mobile, wireless, semi-autonomous NDE inspection robots developed at The University of Strathclyde as part of the UK Research Centre for Non Destructive Evaluation (RCNDE). The inspection vehicles can incorporate a number of different NDE payloads including ultrasonic, eddy current, visual and magnetic based payloads, and have been developed to try and improve NDE inspection techniques in challenging inspection areas (for example oil, gas, and nuclear structures). A significant research challenge remains in the accurate positioning and guidance of such vehicles for real inspection tasks. Employing both relative and absolute position measurements, we discuss a number of approaches to position estimation including Kalman and particle filtering. Using probabilistic approaches enables a common mathematical framework to be employed for both positioning and data fusion from different NDE sensors. In this fashion the uncertainties in both position and defect identification and classification can be dealt with using a consistent approach. A number of practical constraints and considerations to different precision positioning techniques are discussed, along with NDE applications and the potential for improved inspection capabilities by utilising the inherent reconfigurable capabilities of the inspection vehicles.

  2. Inspecting what you expect: Applying modern tools and techniques to evaluate the effectiveness of household energy interventions

    Science.gov (United States)

    Pillarisetti, Ajay

    Exposure to fine particles (PM2.5) resulting from solid fuel use for household energy needs - including cooking, heating, and lighting - is one of the leading causes of ill-health globally and is responsible for approximately 4 million premature deaths and 84 million lost disability-adjusted life years globally. The well-established links between cooking and ill-health are modulated by complex social, behavioral, technological, and environmental issues that pose unique challenges to efforts that seek to reduce this large health burden. Despite growing interest in the field - and numerous technical solutions that, in the laboratory at least, reduce emissions of harmful air pollutants from solid fuel combustion - there exists a need for refined tools, models, and techniques (1) for measuring environmental pollution in households using solid fuel, (2) for tracking adoption of interventions, and (3) for estimating the potential health benefits attributable to an intervention. Part of the need for higher spatial and temporal resolution data on particular concentrations and dynamics is being met by low-cost sensing platforms that provide large amounts of time-resolved data on critical parameters of interest, including PM2.5 concentrations and time-of-use metrics for heat-generating appliances, like stoves. Use of these sensors can result in non-trivial challenges, including those related to data management and analysis, and field logistics, but also enables novel lines of inquiry and insight. Chapter 2 presents a long-term deployment of real-time PM2.5 sensors in rural, solid-fuel-using kitchens, specifically seeking to evaluate how well commonly measured 24 or 48-hour samples represent long-term means. While short-term measures were poor predictors of long-term means, the dataset enabled evaluation of numerous sampling strategies - including sampling once per week, month, or season - that had much lower errors and higher probabilities of estimating the true mean

  3. Summary Report - Inspections of DoD Facilities and Military Housing and Audits of Base Operations and Support Services Contracts

    Science.gov (United States)

    2016-10-14

    integrity , and efficiency; advises the Secretary of Defense and Congress; and informs the public. Vision Our vision is to be a model oversight organization...Report – Inspections of DoD Facilities and Military Housing and Audits of Base Operations and Support Services Contracts O C T O B E R 1 4 , 2 0... information about whistleblower protection, please see the inside back cover. DODIG-2017-004 (Project No. D2016-D000PT-0030.000) │ i Results in Brief

  4. Epidemiologic and economic evaluation of risk-based meat inspection for bovine cysticercosis in Danish cattle

    DEFF Research Database (Denmark)

    Calvo Artavia, Francisco Fernando; Nielsen, Liza Rosenbaum; Alban, L.

    2013-01-01

    system, and highest effectiveness ratios, but they had a lower net economic effect (NEE) than the scenario using risky water sources. Using gender to differentiate high and low-risk groups was judged preferable over grazing due to feasibility, because the information is readily available at the slaughter...... line. The exact total NEE for the cattle sector depends on how many and which of the abattoirs that would be able to reorganise the work at the slaughter line to save money on inspection of the head of carcases. Overall, the SSSe was low in all scenarios leading to undetected BC-positive cattle both...

  5. Ultrasonic Inspection

    Science.gov (United States)

    1976-01-01

    Automation Industries Inc. has had more than $2 million in contracts to produce innovative equipment for the Apollo program. When Marshall Space Flight Center sought a fast nondestructive way to inspect butt welds in aluminum alloys for spacecraft, the company developed a reliable ultrasonic device using multiple transducers called "delta manipulators" which detect lack of weld penetration not readily seen in radiograph automation. Industry soon adapted the ultrasonic equipment to a unique rail inspection device that saves countless man hours. Device is contained in self propelled railroad cars produced and operated by the company to check old track welds for deterioration.

  6. PIE: A Dynamic Failure-Based Technique

    Science.gov (United States)

    Voas, Jeffrey M.

    1990-01-01

    This paper presents a dynamic technique for statistically estimating three program characteristics that affect a program's computational behavior: (1) the probability that a particular section of a program is executed, (2) the probability that the particular section affects the data state, and (3) the probability that a data state produced by that section has an effect on program output. These three characteristics can be used to predict whether faults are likely to be uncovered by software testing. Index Terms: Software testing, data state, fault, failure, testability. 1 Introduction

  7. Path Based Mapping Technique for Robots

    Directory of Open Access Journals (Sweden)

    Amiraj Dhawan

    2013-05-01

    Full Text Available The purpose of this paper is to explore a new way of autonomous mapping. Current systems using perception techniques like LAZER or SONAR use probabilistic methods and have a drawback of allowing considerable uncertainty in the mapping process. Our approach is to break down the environment, specifically indoor, into reachable areas and objects, separated by boundaries, and identifying their shape, to render various navigable paths around them. This is a novel method to do away with uncertainties, as far as possible, at the cost of temporal efficiency. Also this system demands only minimum and cheap hardware, as it relies on only Infra-Red sensors to do the job.

  8. Comparison of Vibration-Based Damage Assessment Techniques

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Rytter, A.

    1995-01-01

    Three different vibration-based damage assessment techniques have been compared. One of the techniques uses the ratios between changes in experimentally and theoretically estimated natural frequencies, respectively, to locate a damage. The second technique relies on updating of a finite element m...

  9. Robust inspection and interpretation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Marriott, D.L. (Stress Engineering Services, Cincinnati, OH (United States))

    1993-05-01

    This paper explores the value of approximate methods of a specific type, as an efficient aid to performing residual life assessments, particularly when input data are incomplete. These methods, referred to as [open quotes]robust[close quotes] have the desirable attributes of providing satisfactory answers using less-than-perfect input, and being very economical in time of execution. Some examples of robust methods, which have been used successfully in high temperature design and fracture evaluations, are presented. 17 refs., 12 figs.

  10. Dual view x-ray inspection system for foreign objects detection in canned food

    Science.gov (United States)

    Lu, Zhiwen; Peng, Ningsong

    2013-04-01

    X-ray inspection technique for foreign objects in food products can determine and mark the presence of contaminants within the product by using image processing and pattern recognition technique on the X-ray transmission images. This paper presents the dual view X-ray inspection technique for foreign objects in food jar via analyzing the weak points of the traditional single view X-ray inspection technique. In addition, a prototype with the new technique is developed in accordance with glass splinters detection within the food jar (glass jar especially) which is a typical tickler. Some algorithms such as: adaptive image segmentation based on contour tracking, nonlinear arctan function transform and etc., are applied to improve image quality and achieve effective inspection results. The false recognition rate is effectively reduced and the detection sensitivity is highly enhanced. Finally the actual test results of this prototype are given.

  11. The base line problem in DLTS technique

    OpenAIRE

    G. Couturier; Thabti, A.; Barrière, A.S.

    1989-01-01

    This paper describes a solution to suppress the base line problem in DLTS spectroscopy using a lock-in amplifier. The method has been used to characterize deep levels in a GaAs Schottky diode. Comparison with the classical method based on the use of a capacitance meter in the differential mode is established. The electric field dependence of the DLTS signal in a weakly doped semiconductor is also reported and proves the efficiency of the method. Finally, the data process is discussed.

  12. Reliability Assessment and Reliability-Based Inspection and Maintenance of Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Ramirez, José Rangel

    performance during the life cycle. The deterioration processes, such as fatigue and corrosion, are typically affecting offshore structural systems. This damage decreases the system performance and increases the risk of failure, thus not fulfilling the established safety criteria. Inspection and maintenance...... to their offshore location, no pollution risks and low human risks since they are unmanned. This allows the allocation of lower reliability level compared to e.g. oil & gas installations. With the incursion to water depths between 20 and 50 meters, the use of jacket and tripod structures represents a feasible...... are to be accounted for. Wake effects imply increased turbulence and thus decrease in OWT fatigue life and performance. In wind farm locations and single/alone locations of offshore wind turbines are considered, and probabilistic models for assessment of the fatigue reliability are developed. Further a reliability...

  13. Ultrasonic Inspection Technique and Qualification for Reactor Pressure Vessel Weld of Nuclear Power Plant%核电站反应堆压力容器焊缝的超声检测及验证

    Institute of Scientific and Technical Information of China (English)

    许远欢; 聂勇

    2013-01-01

      The ultrasonic inspection technique for reactor pressure vessel weld of nuclear power plant was described.The ultrasonic transmission characterization and the influence factors of defects detection and sizing are analyzed in detail .A serial of testing is done to verify the UT technique .The ultrasonic tech-nique can effectively detect and size the defects and has been qualified by the separate qualification cen -ter UK-IVC.The technique meets the requirement of ultrasonic inspection of in -service inspection rules for the mechanical components of PWR nuclear islands (RES-M 1997).%  通过对反应堆压力容器焊缝超声波传播特性以及超声波缺陷探测和定量影响因素的分析,并通过大量的试验测试研究,确定了反应堆压力容器焊缝超声检测技术。此反应堆压力容器超声检测技术,能有效地进行缺陷探测和缺陷定量,并通过了英国验证中心的第三方独立验证,满足核电站役前和在役检查规范(RSE-M 1997)的超声检测技术要求。

  14. An Authentication Technique Based on Classification

    Institute of Scientific and Technical Information of China (English)

    李钢; 杨杰

    2004-01-01

    We present a novel watermarking approach based on classification for authentication, in which a watermark is embedded into the host image. When the marked image is modified, the extracted watermark is also different to the original watermark, and different kinds of modification lead to different extracted watermarks. In this paper, different kinds of modification are considered as classes, and we used classification algorithm to recognize the modifications with high probability. Simulation results show that the proposed method is potential and effective.

  15. Proof of pipeline strength based on measurements of inspection pigs; Festigkeitsnachweis von Pipelines aufgrund der Messergebnisse von Pruefmolchen

    Energy Technology Data Exchange (ETDEWEB)

    De la Camp, H.J.; Feser, G.; Hofmann, A.; Wolf, B.; Schmidt, H. [TUeV Sueddeutschland Bau und Betrieb GmbH, Muenchen (Germany); Herforth, H.E.; Juengling, K.H.; Schmidt, W. [TUeV Anlagentechnik GmbH, Berlin-Schoeneberg (Germany). Unternehmensgruppe TUeV Rheinland/Berlin-Brandenburg

    2002-01-01

    The report is aimed at collecting and documenting the state of the art and the extensive know how of experts and pipeline operators with regard to judging the structural integrity of pipelines. In order to assess the actual mechanical strength of pipelines based on measurement results obtained by inspection pigs, guidance is given for future processing, which eventually can be used as a basis for an industry standard. A literature study of the commercially available types of inspection pigs describes and synoptically lists the respective pros and cons. In essence the report comprises besides check lists of operating data for the pipeline and the pig runs mainly the evaluation of defects and respective calculating procedures. Included are recommendations regarding maintenance planning, verification of defects as well as repetition of pig runs. (orig.) [German] Ziel des Berichtes ist die Erfassung und Dokumentation zum derzeitigen Stand der Technik und des vorhandenen umfangreichen Know-how von Sachverstaendigen und Pipelinebetreibern auf dem Gebiet der sicherheitstechnischen Beurteilung von Pipelines. Fuer den Festigkeitsnachweis von Pipelines aufgrund der Messergebnisse von Pruefmolchen wurde ein Leitfaden als Basis fuer die zukuenftige Vorgehensweise erstellt, der eventuell die Grundlage eines normativen Regelwerkes bilden kann. In einer Literaturstudie wurden die auf dem Markt befindlichen Pruefmolchtypen zusammenfassend beschrieben und ihre Vor- und Nachteile tabellarisch gegenuebergestellt und bewertet. Neben der Erstellung von Checklisten fuer notwendige Daten zum Betrieb der Pipeline und der Molchlaeufe bildet die Fehlerbewertung mit entsprechenden Berechnungsverfahren den Hauptteil dieses Berichtes. Hinweise zur Instandhaltungsplanung (Fehlerverifikation und Molchlaufwiederholung) werden gegeben. (orig.)

  16. Huffman-based code compression techniques for embedded processors

    KAUST Repository

    Bonny, Mohamed Talal

    2010-09-01

    The size of embedded software is increasing at a rapid pace. It is often challenging and time consuming to fit an amount of required software functionality within a given hardware resource budget. Code compression is a means to alleviate the problem by providing substantial savings in terms of code size. In this article we introduce a novel and efficient hardware-supported compression technique that is based on Huffman Coding. Our technique reduces the size of the generated decoding table, which takes a large portion of the memory. It combines our previous techniques, Instruction Splitting Technique and Instruction Re-encoding Technique into new one called Combined Compression Technique to improve the final compression ratio by taking advantage of both previous techniques. The instruction Splitting Technique is instruction set architecture (ISA)-independent. It splits the instructions into portions of varying size (called patterns) before Huffman coding is applied. This technique improves the final compression ratio by more than 20% compared to other known schemes based on Huffman Coding. The average compression ratios achieved using this technique are 48% and 50% for ARM and MIPS, respectively. The Instruction Re-encoding Technique is ISA-dependent. It investigates the benefits of reencoding unused bits (we call them reencodable bits) in the instruction format for a specific application to improve the compression ratio. Reencoding those bits can reduce the size of decoding tables by up to 40%. Using this technique, we improve the final compression ratios in comparison to the first technique to 46% and 45% for ARM and MIPS, respectively (including all overhead that incurs). The Combined Compression Technique improves the compression ratio to 45% and 42% for ARM and MIPS, respectively. In our compression technique, we have conducted evaluations using a representative set of applications and we have applied each technique to two major embedded processor architectures

  17. FDI and Accommodation Using NN Based Techniques

    Science.gov (United States)

    Garcia, Ramon Ferreiro; de Miguel Catoira, Alberto; Sanz, Beatriz Ferreiro

    Massive application of dynamic backpropagation neural networks is used on closed loop control FDI (fault detection and isolation) tasks. The process dynamics is mapped by means of a trained backpropagation NN to be applied on residual generation. Process supervision is then applied to discriminate faults on process sensors, and process plant parameters. A rule based expert system is used to implement the decision making task and the corresponding solution in terms of faults accommodation and/or reconfiguration. Results show an efficient and robust FDI system which could be used as the core of an SCADA or alternatively as a complement supervision tool operating in parallel with the SCADA when applied on a heat exchanger.

  18. Segmentation of Color Images Based on Different Segmentation Techniques

    Directory of Open Access Journals (Sweden)

    Purnashti Bhosale

    2013-03-01

    Full Text Available In this paper, we propose an Color image segmentation algorithm based on different segmentation techniques. We recognize the background objects such as the sky, ground, and trees etc based on the color and texture information using various methods of segmentation. The study of segmentation techniques by using different threshold methods such as global and local techniques and they are compared with one another so as to choose the best technique for threshold segmentation. Further segmentation is done by using clustering method and Graph cut method to improve the results of segmentation.

  19. Enabling inspection solutions for future mask technologies through the development of massively parallel E-Beam inspection

    Science.gov (United States)

    Malloy, Matt; Thiel, Brad; Bunday, Benjamin D.; Wurm, Stefan; Jindal, Vibhu; Mukhtar, Maseeh; Quoi, Kathy; Kemen, Thomas; Zeidler, Dirk; Eberle, Anna Lena; Garbowski, Tomasz; Dellemann, Gregor; Peters, Jan Hendrik

    2015-09-01

    The new device architectures and materials being introduced for sub-10nm manufacturing, combined with the complexity of multiple patterning and the need for improved hotspot detection strategies, have pushed current wafer inspection technologies to their limits. In parallel, gaps in mask inspection capability are growing as new generations of mask technologies are developed to support these sub-10nm wafer manufacturing requirements. In particular, the challenges associated with nanoimprint and extreme ultraviolet (EUV) mask inspection require new strategies that enable fast inspection at high sensitivity. The tradeoffs between sensitivity and throughput for optical and e-beam inspection are well understood. Optical inspection offers the highest throughput and is the current workhorse of the industry for both wafer and mask inspection. E-beam inspection offers the highest sensitivity but has historically lacked the throughput required for widespread adoption in the manufacturing environment. It is unlikely that continued incremental improvements to either technology will meet tomorrow's requirements, and therefore a new inspection technology approach is required; one that combines the high-throughput performance of optical with the high-sensitivity capabilities of e-beam inspection. To support the industry in meeting these challenges SUNY Poly SEMATECH has evaluated disruptive technologies that can meet the requirements for high volume manufacturing (HVM), for both the wafer fab [1] and the mask shop. Highspeed massively parallel e-beam defect inspection has been identified as the leading candidate for addressing the key gaps limiting today's patterned defect inspection techniques. As of late 2014 SUNY Poly SEMATECH completed a review, system analysis, and proof of concept evaluation of multiple e-beam technologies for defect inspection. A champion approach has been identified based on a multibeam technology from Carl Zeiss. This paper includes a discussion on the

  20. Earthquake Analysis of Structure by Base Isolation Technique in SAP

    OpenAIRE

    T. Subramani; J. Jothi

    2014-01-01

    This paper presents an overview of the present state of base isolation techniques with special emphasis and a brief on other techniques developed world over for mitigating earthquake forces on the structures. The dynamic analysis procedure for isolated structures is briefly explained. The provisions of FEMA 450 for base isolated structures are highlighted. The effects of base isolation on structures located on soft soils and near active faults are given in brief. Simple case s...

  1. Array-based techniques for fingerprinting medicinal herbs

    Directory of Open Access Journals (Sweden)

    Xue Charlie

    2011-05-01

    Full Text Available Abstract Poor quality control of medicinal herbs has led to instances of toxicity, poisoning and even deaths. The fundamental step in quality control of herbal medicine is accurate identification of herbs. Array-based techniques have recently been adapted to authenticate or identify herbal plants. This article reviews the current array-based techniques, eg oligonucleotides microarrays, gene-based probe microarrays, Suppression Subtractive Hybridization (SSH-based arrays, Diversity Array Technology (DArT and Subtracted Diversity Array (SDA. We further compare these techniques according to important parameters such as markers, polymorphism rates, restriction enzymes and sample type. The applicability of the array-based methods for fingerprinting depends on the availability of genomics and genetics of the species to be fingerprinted. For the species with few genome sequence information but high polymorphism rates, SDA techniques are particularly recommended because they require less labour and lower material cost.

  2. Inverter-based circuit design techniques for low supply voltages

    CERN Document Server

    Palani, Rakesh Kumar

    2017-01-01

    This book describes intuitive analog design approaches using digital inverters, providing filter architectures and circuit techniques enabling high performance analog circuit design. The authors provide process, supply voltage and temperature (PVT) variation-tolerant design techniques for inverter based circuits. They also discuss various analog design techniques for lower technology nodes and lower power supply, which can be used for designing high performance systems-on-chip.    .

  3. Planning Annual Shutdown Inspection for BFB Boiler

    OpenAIRE

    Sorsa, Tatu

    2014-01-01

    The goal of this thesis was to create an illustrative guidebook of annual inspection planning for BFB boiler to help power plant operator when planning of annual inspection is topical. This thesis was made for Andritz Oy and it is based on inspection reports and experiences of BFB boiler’s maintenance and inspection staff. In this thesis it is shown how to plan an annual inspection for BFB boiler and thesis gives good tools and hints for operator to manage inspection from the beginning ...

  4. Competency-based on-the-job training for aviation maintenance and inspection--a human factors approach.

    Science.gov (United States)

    Walter, D

    2000-08-01

    More than 90% of the critical skills that an aviation maintenance technician uses are acquired through on-the-job training (OJT). Yet many aviation maintenance technicians rely on a 'degenerating buddy system', 'follow Joe around', or unstructured approach to OJT. Many aspects of the aviation maintenance environment point to the need for a structured OJT program, but perhaps the most significant is the practice of job bidding which can create rapid turnover of technicians. The task analytic training system (TATS), a model for developing team-driven structured OJT was developed by the author, and first introduced in Boeing Commercial Airplane Group to provide competency-based OJT for aviation maintenance and inspection personnel. The goal of the model was not only to provide a comprehensive, highly structured training system that could be applied to any maintenance and inspection task, but also to improve team coordination, attitude and morale. The first goal was accomplished by following the systems eight-step process, the latter through incorporating human factors principles such as decision making, communication, team building and conflict resolution into the process itself. In general, the process helps to instill mutual respect and trust, enhance goal-directed behavior, strengthen technicians' self-esteem and responsiveness to new ideas and encourage technicians to make worthwhile contributions. The theoretical background of the model is addressed by illustrating how the proven training methodologies of job task analysis and job instruction training are blended with human factors principles resulting in a unique team-driven approach to training. The paper discusses major elements of the model including needs identification, outlining targeted jobs, writing and verifying training procedures, an approval system, sequencing of training, certifying trainers, implementing, employing tracking mechanisms, evaluating, and establishing a maintenance/audit plan

  5. Customs Inspection

    Science.gov (United States)

    1977-05-01

    required, for the per- DASDD9-%M) ii the single point of contact for formance of customs inspection functions. customs inspecion matters .in the Office...STATUS Onfdlt dotl. member of Rr": 21 DATE if officer of corporation . slu title) ATP OoM 6A N-7s) PtavIoux MuITUONs MAY BE UN&D Figure l-9. Reld.. and...grips. Commonly called HW-4. Serial number over 300,000 denotes the in- corporation of modified hammer safety components. Model HW-5T Double Action

  6. The detection of bulk explosives using nuclear-based techniques

    Energy Technology Data Exchange (ETDEWEB)

    Morgado, R.E.; Gozani, T.; Seher, C.C.

    1988-01-01

    In 1986 we presented a rationale for the detection of bulk explosives based on nuclear techniques that addressed the requirements of civil aviation security in the airport environment. Since then, efforts have intensified to implement a system based on thermal neutron activation (TNA), with new work developing in fast neutron and energetic photon reactions. In this paper we will describe these techniques and present new results from laboratory and airport testing. Based on preliminary results, we contended in our earlier paper that nuclear-based techniques did provide sufficiently penetrating probes and distinguishable detectable reaction products to achieve the FAA operational goals; new data have supported this contention. The status of nuclear-based techniques for the detection of bulk explosives presently under investigation by the US Federal Aviation Administration (FAA) is reviewed. These include thermal neutron activation (TNA), fast neutron activation (FNA), the associated particle technique, nuclear resonance absorption, and photoneutron activation. The results of comprehensive airport testing of the TNA system performed during 1987-88 are summarized. From a technical point of view, nuclear-based techniques now represent the most comprehensive and feasible approach for meeting the operational criteria of detection, false alarms, and throughput. 9 refs., 5 figs., 2 tabs.

  7. Risk-based school inspections in the Netherlands: A critical reflection on intended effects and causal mechanisms

    NARCIS (Netherlands)

    Ehren, M.C.M.; Honingh, M.

    2012-01-01

    This paper compares and contrasts the program theory of the reenacted Supervision Act to the Supervision Act of 2003. We describe how the expectations about how schools should be inspected, the effect such inspections are expected to have, and how these effects should be realized have changed over t

  8. LiDAR-based Localization and Mapping System using Ellipse Distance Correction Models for UAV Wind Turbine Blade Inspection

    DEFF Research Database (Denmark)

    Nikolov, Ivan Adriyanov; Madsen, Claus B.

    2016-01-01

    The wind energy sector faces a constant need for annual inspections of wind turbine blades for damage, erosion and cracks. These inspections are an important part of the wind turbine life cycle and can be very constly and hazardous to specialists. This has led to the use of automated drone...

  9. Computational mask defect review for contamination and haze inspections

    Science.gov (United States)

    Morgan, Paul; Rost, Daniel; Price, Daniel; Corcoran, Noel; Satake, Masaki; Hu, Peter; Peng, Danping; Yonenaga, Dean; Tolani, Vikram; Wolf, Yulian; Shah, Pinkesh

    2013-09-01

    the mask manufacturing process. The latter characterization qualifies real defect signatures, such as pin-dots or pin-holes, extrusions or intrusions, assist-feature or dummy-fill defects, writeerrors or un-repairable defects, chrome-on-shifter or missing chrome-from-shifter defects, particles, etc., and also false defect signatures, such as those due to inspection tool registration or image alignment, interlace artifacts, CCD camera artifacts, optical shimmer, focus errors, etc. Such qualitative characterization of defects has enabled better inspection tool SPC and process defect control in the mask shop. In this paper, the same computational approach to defect review has been extended to contamination style defect inspections, including Die-to-Die reflected, and non Die-to-Die or single-die inspections. In addition to the computational methods used for transmitted aerial images, defects detected in die-to-die reflected light mode are analyzed based on special defect and background coloring in reflected-light, and other characteristics to determine the exact type and severity. For those detected in the non Die-to-Die mode, only defect images are available from the inspection tool. Without a reference, i.e., defect-free image, it is often difficult to determine the true nature or impact of the defect in question. Using a combination of inspection-tool modeling and image inversion techniques, Luminescent's LAIPHTM system generates an accurate reference image, and then proceeds with automated defect characterization as if the images were simply from a die-to-die inspection. The disposition of contamination style defects this way, filters out >90% of false and nuisance defects that otherwise would have been manually reviewed or measured on AIMSTM. Such computational defect review, unifying defect disposition across all available inspection modes, has been imperative to ensuring no yield losses due to errors in operator defect classification on one hand, and on the other

  10. 基于GPS的输电线路巡检%Inspection of Power Transmission Line Based on GPS

    Institute of Scientific and Technical Information of China (English)

    胡春霞; 王素珍; 孙成龙

    2012-01-01

    在电力系统中,架空高压输电线路是重要组成部分.为了保证输电线路的稳定安全运行、减少巡检员的工作量、同时为管理人员提供有效的监督依据,文中开发了基于GPS的输电线路巡检系统,该系统由终端手持机和后台管理系统组成,集卫星定位系统(GPs)、计算机通信技术和手持式处理终端于一体,具有低成本、操作方便、使用时间长等特点.该系统具有安排线路、记录数据、监督工作状态.汇总数据等功能,同时实现了无纸化办公以及巡检标准的规范化.%In the power system,overhead high voltage transmission lines are an important part. In order to ensure a stable and secure operation of transmission lines .reduce the workload of patrol members, and provide effective supervision for managers, discuss the inspection management system based on the global position system (GPS). H is composed of the terminal handheld and the backstage management system, which unifies the function of the global position system,computer network communication technology and portable information processing terminal The system has the advantages of low cost,convenient operation,long service time and other characteristics. With functions of line arrangements,data recording,supervision of the working state and summary report of data,achieve paperless office and specification of inspection standards.

  11. Inspecting less to inspect better: The use of data mining for risk management by customs administrations

    OpenAIRE

    COUNDOUL, Ousmane; Massene GADIAGA; Anne-Marie GEOURJON; Laporte, Bertrand

    2012-01-01

    In order to limit the number of intrusive inspections, the most modern customs administrations rely on risk analysis as the only effective tool for facilitating trade and securing their operations given the important growth in trade volume in recent years. However, customs administrations in developing countries have been slow to adopt this methodology. This paper demonstrates that based on the experience of Senegal, data mining and statistical scoring techniques can be used effectively by cu...

  12. Modelling in Optimal Inspection and Repair

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Rackwitz, R.; Faber, M.H.;

    1991-01-01

    A model for reliability based optimal inspection and repair strategies is described. The total expected costs in the lifetime is minimized with the number of inspections, the inspection times and efforts, the repair crack size limit and a design parameter as optimization variables. The equivalenc...

  13. A Pipeline Inspection Micro Robot Based on Screw Motion Wheels%采用螺旋驱动轮的管道检测用微机器人

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The micro robot based on screw motion wheels, which features high payload/mass ratio, fast and continuous motion, adaptation to pipe diameter or roundness variations, is suitable for locomotion and inspection inside small-diameter pipelines. The robot inspection system, Tubot I, developed at Shanghai University is composed of locomotion mechanism with an inner motor, a micro CCD camera and a monitor outside the pipeline. In the paper, the kinematics and statics analyses are presented for the screw locomotion system of Tubot I.The moving characteristics are obtained from experiments on the robot prototype.

  14. Robotic inspection of fiber reinforced composites using phased array UT

    Science.gov (United States)

    Stetson, Jeffrey T.; De Odorico, Walter

    2014-02-01

    Ultrasound is the current NDE method of choice to inspect large fiber reinforced airframe structures. Over the last 15 years Cartesian based scanning machines using conventional ultrasound techniques have been employed by all airframe OEMs and their top tier suppliers to perform these inspections. Technical advances in both computing power and commercially available, multi-axis robots now facilitate a new generation of scanning machines. These machines use multiple end effector tools taking full advantage of phased array ultrasound technologies yielding substantial improvements in inspection quality and productivity. This paper outlines the general architecture for these new robotic scanning systems as well as details the variety of ultrasonic techniques available for use with them including advances such as wide area phased array scanning and sound field adaptation for non-flat, non-parallel surfaces.

  15. Methodological aspects of a GIS-based environmental health inspection program used in the Athens 2004 Olympic and Para Olympic Games

    Directory of Open Access Journals (Sweden)

    Pantelopoulos Efstathios

    2005-09-01

    Full Text Available Abstract Background The use of geographical information system (GIS technologies in public health surveillance is gradually gaining momentum around the world and many applications have already been reported in the literature. In this study, GIS technology was used to help county departments of Public Health to implement environmental health surveillance for the Athens 2004 Olympic and Para Olympic Games. Methods In order to assess the workload in each Olympic county, 19 registry forms and 17 standardized inspection forms were developed to register and inspect environmental health items requiring inspection (Hotels, restaurants, swimming pools, water supply system etc, respectively. Furthermore, related databases were created using Epi Info 2002 and a geographical information system (GIS were used to implement an integrated Environmental Health inspection program. The project was conducted in Athens by the Olympic Planning Unit (OPU of the National School of Public Health, in close cooperation with the Ministry of Health and Social Solidarity and the corresponding departments of Public Health in all municipalities that were scheduled to host events during the Athens 2004 Olympic and Para Olympic games. Results A total of 44,741 premises of environmental health interest were geocoded into GIS databases and several electronic maps were developed. Using such maps in association with specific criteria, we first identified the maximum workload required to execute environmental health inspections in all premises within the eleven Olympic County Departments of Public Health. Six different scenarios were created for each county, based on devised algorithms in order to design the most effective and realistic inspection program using the available inspectors from each municipality. Furthermore, GIS applications were used to organize the daily inspection program for the Olympic games, provide coloured displays of the inspection results and link those

  16. Clustering condition-based maintenance for a multi-unit system with aperiodic inspections

    NARCIS (Netherlands)

    Olde Keizer, Minou C.A.; Teunter, Ruud H.; Podofillini, Luca; Sudret, Bruno; Stojadinović, Božidar; Zio, Enrico; Kröger, Wolfgang

    2015-01-01

    Condition-Based Maintenance (CBM) is a predictive maintenance strategy, which bases the maintenance scheduling on condition measurements of the components. In this paper, we continue work on the CBM optimization approach proposed by Castanier, B., A. Grall & C. Bérenguer (2005). A condition-based ma

  17. Inspection of dissimilar metal welds in reactor pressure vessels in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Gadea, J.R.; Regidor, J.J.; Pelaez, J.A.; Serrano, P. [Tecnatom, S.A., San Sebastian de los Reyes, Madrid (Spain)

    2011-07-01

    MRP-139 recommendations for inspection of dissimilar metal (DM) welds in PWR vessels were launched in the last years in the USA. Basically, it increases the frequency of the examinations in these type of welds, with major emphasis in the hot loops, adding one intermediate inspection at the ten years interval in outlet nozzles. The spanish nuclear power plants (NPP's) have begun the implementation of this type of inspections on the vessel nozzles DM welds. As this type of inspections could have an impact in the critical path duration of the outage, it is necessary the use of a mechanical equipment able to examine the nozzles DM welds in a short vessel occupation time (VOT) with high quality, qualified techniques and minimum requirements of the refuelling platform. Tecnatom undertook the design and development of a new more advanced equipment, named TENIS-DM, for implementing the reactor pressure vessel (RPV) nozzles examination. This equipment was designed in order to accomplish the stringent requirements and the updated examination techniques; it was used for the inspection of the DM welds of Asco 1 NPP inlet and outlet nozzles in March 2011. Examination techniques and procedures were qualified through the GRUVAL validation program, based on ENIC methodology. Mechanical scanner was equipped with a large number of examination probes, and TV cameras -for visual inspection and also for monitoring the ultrasonic inspections. A remote operated submarine was also used to give support to the operational personnel during the manipulation of the equipment and its movements from one nozzle to the others. During two months before the inspection, tests of the complete inspection system were made on a nozzle mock-up installed in a 4 meters deep well at Tecnatom's facilities; this scenario was also used during the training sessions of the inspection crew. The defined technical and practical objectives were achieved: use of qualified techniques and minimal impact on the

  18. Simplified Approach to Inspection Planning

    DEFF Research Database (Denmark)

    Bloch, Allan; Sørensen, John Dalsgaard; Faber, M. H.

    2000-01-01

    A simplified and practically applicable approach for risk based inspection planning of fatigue sensitive structural details is presented. The basic idea behind the approach is that the fatigue sensitive details are categorized according to their stress intensity factors and their design fatigue l...... of steel structures. The validity of the proposed approach is illustrated through a study regarding inspection planning of offshore structures....... life to service life ratio, i.e. the fatigue design factor (FDF) and SN curve. When the reserve strength ratio (RSR) and the corresponding probability of total structural failure given fatigue failure of the considered detail is known it is possible to make a generic description of fatigue sensitive...... structural details and thereby develop pre-made inspection plans in tables which depend on relative cost of inspections, repairs and failures. Due to the simplicity of the format of the developed inspection plans the proposed approach has a high potential in code making for the design and maintenance...

  19. Satellite-based enhancement of archaeological marks through data fusion techniques

    Science.gov (United States)

    Lasaponara, Rosa; Masini, Nicola; Aiazzi, Bruno; Alparone, Luciano; Baronti, Stefano

    2008-10-01

    The application of space technology to archaeological research has been paid great attention worldwide, mainly because the current availability of very high resolution (VHR) satellite imagery, such as, IKONOS (1999) and QuickBird (2001), provide valuable data for searching large areas to find potential archaeological sites. Data from VHR satellite can be very useful for the identification, management and documentation of archaeological resources. Archaeological investigation based on the use of VHR satellite images may take benefits from the integration and synergic use of both panchromatic and multispectral data. This can be achieved by using pansharpening techniques, which allow multispectral and panchromatic images to be merged. The two basic frameworks of pansharpening techniques are Component Substitution (CS), such as Intensity-Hue-Saturation (IHS) Gram-Schmidt (GS), and multiresolution analysis (MRA), such as wavelets and Laplacian pyramids (LP). In this paper, both Gram-Schmidt and Laplacian pyramids with context adaptive (CA) detail injection models were used. QB images were processed for a relevant archaeological area in Southern Italy, the ancient Siris-Heraclea, a very significant test area because it is characterized by the presence of both surface and subsurface ancient remains. Outcomes of different pansharpening techniques have been qualitatively evaluated for both surface and subsurface remains. The visual inspection clearly suggests that the quantitative evaluation of the fusion performance for archaeological applications is a critical issue, and "ad hoc" local (i.e. context-adaptive) indices need to be developed.

  20. An Improved Particle Swarm Optimization Algorithm Based on Ensemble Technique

    Institute of Scientific and Technical Information of China (English)

    SHI Yan; HUANG Cong-ming

    2006-01-01

    An improved particle swarm optimization (PSO) algorithm based on ensemble technique is presented. The algorithm combines some previous best positions (pbest) of the particles to get an ensemble position (Epbest), which is used to replace the global best position (gbest). It is compared with the standard PSO algorithm invented by Kennedy and Eberhart and some improved PSO algorithms based on three different benchmark functions. The simulation results show that the improved PSO based on ensemble technique can get better solutions than the standard PSO and some other improved algorithms under all test cases.

  1. Efficient Plant Supervision Strategy Using NN Based Techniques

    Science.gov (United States)

    Garcia, Ramon Ferreiro; Rolle, Jose Luis Calvo; Castelo, Francisco Javier Perez

    Most of non-linear type one and type two control systems suffers from lack of detectability when model based techniques are applied on FDI (fault detection and isolation) tasks. In general, all types of processes suffer from lack of detectability also due to the ambiguity to discriminate the process, sensors and actuators in order to isolate any given fault. This work deals with a strategy to detect and isolate faults which include massive neural networks based functional approximation procedures associated to recursive rule based techniques applied to a parity space approach.

  2. Power system stabilizers based on modern control techniques

    Energy Technology Data Exchange (ETDEWEB)

    Malik, O.P.; Chen, G.P.; Zhang, Y.; El-Metwally, K. [Calgary Univ., AB (Canada). Dept. of Electrical and Computer Engineering

    1994-12-31

    Developments in digital technology have made it feasible to develop and implement improved controllers based on sophisticated control techniques. Power system stabilizers based on adaptive control, fuzzy logic and artificial networks are being developed. Each of these control techniques possesses unique features and strengths. In this paper, the relative performance of power systems stabilizers based on adaptive control, fuzzy logic and neural network, both in simulation studies and real time tests on a physical model of a power system, is presented and compared to that of a fixed parameter conventional power system stabilizer. (author) 16 refs., 45 figs., 3 tabs.

  3. Data Mining and Neural Network Techniques in Case Based System

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper first puts forward a case-based system framework basedon data mining techniques. Then the paper examines the possibility of using neural n etworks as a method of retrieval in such a case-based system. In this system we propose data mining algorithms to discover case knowledge and other algorithms.

  4. Decomposition Techniques and Effective Algorithms in Reliability-Based Optimization

    DEFF Research Database (Denmark)

    Enevoldsen, I.; Sørensen, John Dalsgaard

    1995-01-01

    The common problem of an extensive number of limit state function calculations in the various formulations and applications of reliability-based optimization is treated. It is suggested to use a formulation based on decomposition techniques so the nested two-level optimization problem can be solved...

  5. An Agent Communication Framework Based on XML and SOAP Technique

    Institute of Scientific and Technical Information of China (English)

    李晓瑜

    2009-01-01

    This thesis introducing XML technology and SOAP technology,present an agent communication fi-amework based on XML and SOAP technique,and analyze the principle,architecture,function and benefit of it. At the end, based on KQML communication primitive lan- guages.

  6. Simulation-based optimization parametric optimization techniques and reinforcement learning

    CERN Document Server

    Gosavi, Abhijit

    2003-01-01

    Simulation-Based Optimization: Parametric Optimization Techniques and Reinforcement Learning introduces the evolving area of simulation-based optimization. The book's objective is two-fold: (1) It examines the mathematical governing principles of simulation-based optimization, thereby providing the reader with the ability to model relevant real-life problems using these techniques. (2) It outlines the computational technology underlying these methods. Taken together these two aspects demonstrate that the mathematical and computational methods discussed in this book do work. Broadly speaking, the book has two parts: (1) parametric (static) optimization and (2) control (dynamic) optimization. Some of the book's special features are: *An accessible introduction to reinforcement learning and parametric-optimization techniques. *A step-by-step description of several algorithms of simulation-based optimization. *A clear and simple introduction to the methodology of neural networks. *A gentle introduction to converg...

  7. A Hough Transform based Technique for Text Segmentation

    CERN Document Server

    Saha, Satadal; Nasipuri, Mita; Basu, Dipak Kr

    2010-01-01

    Text segmentation is an inherent part of an OCR system irrespective of the domain of application of it. The OCR system contains a segmentation module where the text lines, words and ultimately the characters must be segmented properly for its successful recognition. The present work implements a Hough transform based technique for line and word segmentation from digitized images. The proposed technique is applied not only on the document image dataset but also on dataset for business card reader system and license plate recognition system. For standardization of the performance of the system the technique is also applied on public domain dataset published in the website by CMATER, Jadavpur University. The document images consist of multi-script printed and hand written text lines with variety in script and line spacing in single document image. The technique performs quite satisfactorily when applied on mobile camera captured business card images with low resolution. The usefulness of the technique is verifie...

  8. Memory Based Machine Intelligence Techniques in VLSI hardware

    OpenAIRE

    James, Alex Pappachen

    2012-01-01

    We briefly introduce the memory based approaches to emulate machine intelligence in VLSI hardware, describing the challenges and advantages. Implementation of artificial intelligence techniques in VLSI hardware is a practical and difficult problem. Deep architectures, hierarchical temporal memories and memory networks are some of the contemporary approaches in this area of research. The techniques attempt to emulate low level intelligence tasks and aim at providing scalable solutions to high ...

  9. Memory Based Machine Intelligence Techniques in VLSI hardware

    CERN Document Server

    James, Alex Pappachen

    2012-01-01

    We briefly introduce the memory based approaches to emulate machine intelligence in VLSI hardware, describing the challenges and advantages. Implementation of artificial intelligence techniques in VLSI hardware is a practical and difficult problem. Deep architectures, hierarchical temporal memories and memory networks are some of the contemporary approaches in this area of research. The techniques attempt to emulate low level intelligence tasks and aim at providing scalable solutions to high level intelligence problems such as sparse coding and contextual processing.

  10. Image analysis techniques associated with automatic data base generation.

    Science.gov (United States)

    Bond, A. D.; Ramapriyan, H. K.; Atkinson, R. J.; Hodges, B. C.; Thomas, D. T.

    1973-01-01

    This paper considers some basic problems relating to automatic data base generation from imagery, the primary emphasis being on fast and efficient automatic extraction of relevant pictorial information. Among the techniques discussed are recursive implementations of some particular types of filters which are much faster than FFT implementations, a 'sequential similarity detection' technique of implementing matched filters, and sequential linear classification of multispectral imagery. Several applications of the above techniques are presented including enhancement of underwater, aerial and radiographic imagery, detection and reconstruction of particular types of features in images, automatic picture registration and classification of multiband aerial photographs to generate thematic land use maps.

  11. MPPT Technique Based on Current and Temperature Measurements

    Directory of Open Access Journals (Sweden)

    Eduardo Moreira Vicente

    2015-01-01

    Full Text Available This paper presents a new maximum power point tracking (MPPT method based on the measurement of temperature and short-circuit current, in a simple and efficient approach. These measurements, which can precisely define the maximum power point (MPP, have not been used together in other existing techniques. The temperature is measured with a low cost sensor and the solar irradiance is estimated through the relationship of the measured short-circuit current and its reference. Fast tracking speed and stable steady-state operation are advantages of this technique, which presents higher performance when compared to other well-known techniques.

  12. Improve mask inspection capacity with Automatic Defect Classification (ADC)

    Science.gov (United States)

    Wang, Crystal; Ho, Steven; Guo, Eric; Wang, Kechang; Lakkapragada, Suresh; Yu, Jiao; Hu, Peter; Tolani, Vikram; Pang, Linyong

    2013-09-01

    As optical lithography continues to extend into low-k1 regime, resolution of mask patterns continues to diminish. The adoption of RET techniques like aggressive OPC, sub-resolution assist features combined with the requirements to detect even smaller defects on masks due to increasing MEEF, poses considerable challenges for mask inspection operators and engineers. Therefore a comprehensive approach is required in handling defects post-inspections by correctly identifying and classifying the real killer defects impacting the printability on wafer, and ignoring nuisance defect and false defects caused by inspection systems. This paper focuses on the results from the evaluation of Automatic Defect Classification (ADC) product at the SMIC mask shop for the 40nm technology node. Traditionally, each defect is manually examined and classified by the inspection operator based on a set of predefined rules and human judgment. At SMIC mask shop due to the significant total number of detected defects, manual classification is not cost-effective due to increased inspection cycle time, resulting in constrained mask inspection capacity, since the review has to be performed while the mask stays on the inspection system. Luminescent Technologies Automated Defect Classification (ADC) product offers a complete and systematic approach for defect disposition and classification offline, resulting in improved utilization of the current mask inspection capability. Based on results from implementation of ADC in SMIC mask production flow, there was around 20% improvement in the inspection capacity compared to the traditional flow. This approach of computationally reviewing defects post mask-inspection ensures no yield loss by qualifying reticles without the errors associated with operator mis-classification or human error. The ADC engine retrieves the high resolution inspection images and uses a decision-tree flow to classify a given defect. Some identification mechanisms adopted by ADC to

  13. A novel lobster-eye imaging system based on Schmidt-type objective for X-ray-backscattering inspection

    Science.gov (United States)

    Xu, Jie; Wang, Xin; Zhan, Qi; Huang, Shengling; Chen, Yifan; Mu, Baozhong

    2016-07-01

    This paper presents a novel lobster-eye imaging system for X-ray-backscattering inspection. The system was designed by modifying the Schmidt geometry into a treble-lens structure in order to reduce the resolution difference between the vertical and horizontal directions, as indicated by ray-tracing simulations. The lobster-eye X-ray imaging system is capable of operating over a wide range of photon energies up to 100 keV. In addition, the optics of the lobster-eye X-ray imaging system was tested to verify that they meet the requirements. X-ray-backscattering imaging experiments were performed in which T-shaped polymethyl-methacrylate objects were imaged by the lobster-eye X-ray imaging system based on both the double-lens and treble-lens Schmidt objectives. The results show similar resolution of the treble-lens Schmidt objective in both the vertical and horizontal directions. Moreover, imaging experiments were performed using a second treble-lens Schmidt objective with higher resolution. The results show that for a field of view of over 200 mm and with a 500 mm object distance, this lobster-eye X-ray imaging system based on a treble-lens Schmidt objective offers a spatial resolution of approximately 3 mm.

  14. Runtime Monitoring Technique to handle Tautology based SQL Injection Attacks

    Directory of Open Access Journals (Sweden)

    Ramya Dharam

    2015-05-01

    Full Text Available Software systems, like web applications, are often used to provide reliable online services such as banking, shopping, social networking, etc., to users. The increasing use of such systems has led to a high need for assuring confidentiality, integrity, and availability of user data. SQL Injection Attacks (SQLIAs is one of the major security threats to web applications. It allows attackers to get unauthorized access to the back-end database consisting of confidential user information. In this paper we present and evaluate a Runtime Monitoring Technique to detect and prevent tautology based SQLIAs in web applications. Our technique monitors the behavior of the application during its post- deployment to identify all the tautology based SQLIAs. A framework called Runtime Monitoring Framework, that implements our technique, is used in the development of runtime monitors. The framework uses two pre-deployment testing techniques, such as basis-path and data-flow to identify a minimal set of all legal/valid execution paths of the application. Runtime monitors are then developed and integrated to perform runtime monitoring of the application, during its post-deployment for the identified valid/legal execution paths. For evaluation we targeted a subject application with a large number of both legitimate inputs and illegitimate tautology based inputs, and measured the performance of the proposed technique. The results of our study show that runtime monitor developed for the application was successfully able to detect all the tautology based attacks without generating any false positives.

  15. Laser-based direct-write techniques for cell printing.

    Science.gov (United States)

    Schiele, Nathan R; Corr, David T; Huang, Yong; Raof, Nurazhani Abdul; Xie, Yubing; Chrisey, Douglas B

    2010-09-01

    Fabrication of cellular constructs with spatial control of cell location (+/-5 microm) is essential to the advancement of a wide range of applications including tissue engineering, stem cell and cancer research. Precise cell placement, especially of multiple cell types in co- or multi-cultures and in three dimensions, can enable research possibilities otherwise impossible, such as the cell-by-cell assembly of complex cellular constructs. Laser-based direct writing, a printing technique first utilized in electronics applications, has been adapted to transfer living cells and other biological materials (e.g., enzymes, proteins and bioceramics). Many different cell types have been printed using laser-based direct writing, and this technique offers significant improvements when compared to conventional cell patterning techniques. The predominance of work to date has not been in application of the technique, but rather focused on demonstrating the ability of direct writing to pattern living cells, in a spatially precise manner, while maintaining cellular viability. This paper reviews laser-based additive direct-write techniques for cell printing, and the various cell types successfully laser direct-written that have applications in tissue engineering, stem cell and cancer research are highlighted. A particular focus is paid to process dynamics modeling and process-induced cell injury during laser-based cell direct writing.

  16. Laser-based direct-write techniques for cell printing

    Energy Technology Data Exchange (ETDEWEB)

    Schiele, Nathan R; Corr, David T [Biomedical Engineering Department, Rensselaer Polytechnic Institute, Troy, NY (United States); Huang Yong [Department of Mechanical Engineering, Clemson University, Clemson, SC (United States); Raof, Nurazhani Abdul; Xie Yubing [College of Nanoscale Science and Engineering, University at Albany, SUNY, Albany, NY (United States); Chrisey, Douglas B, E-mail: schien@rpi.ed, E-mail: chrisd@rpi.ed [Material Science and Engineering Department, Rensselaer Polytechnic Institute, Troy, NY (United States)

    2010-09-15

    Fabrication of cellular constructs with spatial control of cell location ({+-}5 {mu}m) is essential to the advancement of a wide range of applications including tissue engineering, stem cell and cancer research. Precise cell placement, especially of multiple cell types in co- or multi-cultures and in three dimensions, can enable research possibilities otherwise impossible, such as the cell-by-cell assembly of complex cellular constructs. Laser-based direct writing, a printing technique first utilized in electronics applications, has been adapted to transfer living cells and other biological materials (e.g., enzymes, proteins and bioceramics). Many different cell types have been printed using laser-based direct writing, and this technique offers significant improvements when compared to conventional cell patterning techniques. The predominance of work to date has not been in application of the technique, but rather focused on demonstrating the ability of direct writing to pattern living cells, in a spatially precise manner, while maintaining cellular viability. This paper reviews laser-based additive direct-write techniques for cell printing, and the various cell types successfully laser direct-written that have applications in tissue engineering, stem cell and cancer research are highlighted. A particular focus is paid to process dynamics modeling and process-induced cell injury during laser-based cell direct writing. (topical review)

  17. PCA Based Rapid and Real Time Face Recognition Technique

    Directory of Open Access Journals (Sweden)

    T R Chandrashekar

    2013-12-01

    Full Text Available Economical and efficient that is used in various applications is face Biometric which has been a popular form biometric system. Face recognition system is being a topic of research for last few decades. Several techniques are proposed to improve the performance of face recognition system. Accuracy is tested against intensity, distance from camera, and pose variance. Multiple face recognition is another subtopic which is under research now a day. Speed at which the technique works is a parameter under consideration to evaluate a technique. As an example a support vector machine performs really well for face recognition but the computational efficiency degrades significantly with increase in number of classes. Eigen Face technique produces quality features for face recognition but the accuracy is proved to be comparatively less to many other techniques. With increase in use of core processors in personal computers and application demanding speed in processing and multiple face detection and recognition system (for example an entry detection system in shopping mall or an industry, demand for such systems are cumulative as there is a need for automated systems worldwide. In this paper we propose a novel system of face recognition developed with C# .Net that can detect multiple faces and can recognize the faces parallel by utilizing the system resources and the core processors. The system is built around Haar Cascade based face detection and PCA based face recognition system with C#.Net. Parallel library designed for .Net is used to aide to high speed detection and recognition of the real time faces. Analysis of the performance of the proposed technique with some of the conventional techniques reveals that the proposed technique is not only accurate, but also is fast in comparison to other techniques.

  18. A Knowledge—Based Specification Technique for Protocol Development

    Institute of Scientific and Technical Information of China (English)

    张尧学; 史美林; 等

    1993-01-01

    is paper proposes a knowledge-based specification technique(KST)for protocol development.This technique semi-automatically translates a protocol described in an informal description(natural languages or graphs)into one described in forml specifications(Estells and SDL).The translation processes are suported by knowledge stored in the knowledge base.This paper discusses the concept,the specification control mechanism of KST and the rules and algorithms for production of FSM's which is the basis of Estelle and SDL.

  19. Rules for Supervision and Inspection of Offshore Oil Industry

    Institute of Scientific and Technical Information of China (English)

    Dai Zhongliang; Song Lisong

    1994-01-01

    @@ In short,safety supervision and technique inspection mean the safety supervision by the government,and the inspection by technical organization,and those are put into practice by a series of administrative rules and regulations.

  20. Collaborative Video Search Combining Video Retrieval with Human-Based Visual Inspection

    NARCIS (Netherlands)

    Hudelist, M.A.; Cobârzan, C.; Beecks, C.; van de Werken, Rob; Kletz, S.; Hürst, W.O.; Schoeffmann, K.

    2016-01-01

    We propose a novel video browsing approach that aims at optimally integrating traditional, machine-based retrieval methods with an interface design optimized for human browsing performance. Advanced video retrieval and filtering (e.g., via color and motion signatures, and visual concepts) on a deskt

  1. Hardware-based image processing for high-speed inspection of grains

    Science.gov (United States)

    A high-speed, low-cost, image-based sorting device was developed to detect and separate grains with slight color differences and small defects on grains The device directly combines a complementary metal–oxide–semiconductor (CMOS) color image sensor with a field-programmable gate array (FPGA) which...

  2. Application of x rays to nonintrusive inspection: an assessment

    Science.gov (United States)

    Leach, Eugene R.; Spradling, Michael L.

    1995-05-01

    Two Advanced Research Projects Agency (ARPA) sponsored x-ray nonintrusive inspection system test programs have recently been conducted. A high energy x-ray system designed to inspect air-sea-land intermodal cargo containers and their contents was tested at the Nonintrusive Inspection Technology Testbed (NITT) located in the Port of Tacoma, Washington and a low energy x-ray system designed primarily to examine empty tractor trailer vehicles was tested at the Commercial Inspection Border Crossing Facility at Otay Mesa, California. Both test programs involved the use of a Red/Blue/Silver Team test concept and were conducted in accordance with test protocols. The 'Red Team' which represented the 'smugglers' has the responsibility for preparing cargoes/vehicles for inspection at a location off-site from the inspection facilities. A computer-based algorithm originally developed under contract with ARPA for testing at the NITT was used to randomly select the preparation of the cargoes. The control vehicles were subsequently sent to the test site for x-ray interrogation and analysis. The 'Blue Team' which represented US Customs Service operations analyzed the x- ray images and made recommendation for release/inspection of the control vehicles. The results of the analyses were returned to the Red Team location for evaluation and data compilation by an unbiased observation team. This paper presents discussions related to these x-ray systems' tests including transport techniques, the use of backscatter and transmission imaging for cargo inspection, resolution, analytical tools, and other related considerations for these two systems.

  3. Dimensionality Reduction using SOM based Technique for Face Recognition

    Directory of Open Access Journals (Sweden)

    Dinesh Kumar

    2008-05-01

    Full Text Available Unsupervised or Self-Organized learning algorithms have become very popular for discovery of significant patterns or features in the input data. The three prominent algorithms namely Principal Component Analysis (PCA, Self Organizing Maps (SOM, and Independent Component Analysis (ICA have widely and successfully been used for face recognition. In this paper a SOM based technique for dimensionality reduction has been proposed. This technique has also been successfully used for face recognition. A comparative study of PCA, SOM and ICA along with the proposed technique for face recognition has also been given. Simulation results indicate that SOM is better than the other techniques for the given face database and the classifier used. The results also show that the performance of the system decreases as the number of classes increase.

  4. Least-squares based iterative multipath super-resolution technique

    CERN Document Server

    Nam, Wooseok

    2011-01-01

    In this paper, we study the problem of multipath channel estimation for direct sequence spread spectrum signals. To resolve multipath components arriving within a short interval, we propose a new algorithm called the least-squares based iterative multipath super-resolution (LIMS). Compared to conventional super-resolution techniques, such as the multiple signal classification (MUSIC) and the estimation of signal parameters via rotation invariance techniques (ESPRIT), our algorithm has several appealing features. In particular, even in critical situations where the conventional super-resolution techniques are not very powerful due to limited data or the correlation between path coefficients, the LIMS algorithm can produce successful results. In addition, due to its iterative nature, the LIMS algorithm is suitable for recursive multipath tracking, whereas the conventional super-resolution techniques may not be. Through numerical simulations, we show that the LIMS algorithm can resolve the first arrival path amo...

  5. Fault Based Techniques for Testing Boolean Expressions: A Survey

    CERN Document Server

    Badhera, Usha; Taruna, S

    2012-01-01

    Boolean expressions are major focus of specifications and they are very much prone to introduction of faults, this survey presents various fault based testing techniques. It identifies that the techniques differ in their fault detection capabilities and generation of test suite. The various techniques like Cause effect graph, meaningful impact strategy, Branch Operator Strategy (BOR), BOR+MI, MUMCUT, Modified Condition/ Decision Coverage (MCDC) has been considered. This survey describes the basic algorithms and fault categories used by these strategies for evaluating their performance. Finally, it contains short summaries of the papers that use Boolean expressions used to specify the requirements for detecting faults. These techniques have been empirically evaluated by various researchers on a simplified safety related real time control system.

  6. Membrane-based microextraction techniques in analytical chemistry: A review.

    Science.gov (United States)

    Carasek, Eduardo; Merib, Josias

    2015-06-23

    The use of membrane-based sample preparation techniques in analytical chemistry has gained growing attention from the scientific community since the development of miniaturized sample preparation procedures in the 1990s. The use of membranes makes the microextraction procedures more stable, allowing the determination of analytes in complex and "dirty" samples. This review describes some characteristics of classical membrane-based microextraction techniques (membrane-protected solid-phase microextraction, hollow-fiber liquid-phase microextraction and hollow-fiber renewal liquid membrane) as well as some alternative configurations (thin film and electromembrane extraction) used successfully for the determination of different analytes in a large variety of matrices, some critical points regarding each technique are highlighted.

  7. A Novel Nanofabrication Technique of Silicon-Based Nanostructures

    Science.gov (United States)

    Meng, Lingkuan; He, Xiaobin; Gao, Jianfeng; Li, Junjie; Wei, Yayi; Yan, Jiang

    2016-11-01

    A novel nanofabrication technique which can produce highly controlled silicon-based nanostructures in wafer scale has been proposed using a simple amorphous silicon (α-Si) material as an etch mask. SiO2 nanostructures directly fabricated can serve as nanotemplates to transfer into the underlying substrates such as silicon, germanium, transistor gate, or other dielectric materials to form electrically functional nanostructures and devices. In this paper, two typical silicon-based nanostructures such as nanoline and nanofin have been successfully fabricated by this technique, demonstrating excellent etch performance. In addition, silicon nanostructures fabricated above can be further trimmed to less than 10 nm by combing with assisted post-treatment methods. The novel nanofabrication technique will be expected a new emerging technology with low process complexity and good compatibility with existing silicon integrated circuit and is an important step towards the easy fabrication of a wide variety of nanoelectronics, biosensors, and optoelectronic devices.

  8. Methodology to identify risk-significant components for inservice inspection and testing

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, M.T.; Hartley, R.S.; Jones, J.L. Jr.; Kido, C.; Phillips, J.H.

    1992-08-01

    Periodic inspection and testing of vital system components should be performed to ensure the safe and reliable operation of Department of Energy (DOE) nuclear processing facilities. Probabilistic techniques may be used to help identify and rank components by their relative risk. A risk-based ranking would allow varied DOE sites to implement inspection and testing programs in an effective and cost-efficient manner. This report describes a methodology that can be used to rank components, while addressing multiple risk issues.

  9. Full-duplex MIMO system based on antenna cancellation technique

    DEFF Research Database (Denmark)

    Foroozanfard, Ehsan; Franek, Ondrej; Tatomirescu, Alexandru

    2014-01-01

    The performance of an antenna cancellation technique for a multiple-input– multiple-output (MIMO) full-duplex system that is based on null-steering beamforming and antenna polarization diversity is investigated. A practical implementation of a symmetric antenna topology comprising three dual-pola...

  10. Heuristic evaluation of paper-based Web pages: a simplified inspection usability methodology.

    Science.gov (United States)

    Allen, Mureen; Currie, Leanne M; Bakken, Suzanne; Patel, Vimla L; Cimino, James J

    2006-08-01

    Online medical information, when presented to clinicians, must be well-organized and intuitive to use, so that the clinicians can conduct their daily work efficiently and without error. It is essential to actively seek to produce good user interfaces that are acceptable to the user. This paper describes the methodology used to develop a simplified heuristic evaluation (HE) suitable for the evaluation of screen shots of Web pages, the development of an HE instrument used to conduct the evaluation, and the results of the evaluation of the aforementioned screen shots. In addition, this paper presents examples of the process of categorizing problems identified by the HE and the technological solutions identified to resolve these problems. Four usability experts reviewed 18 paper-based screen shots and made a total of 108 comments. Each expert completed the task in about an hour. We were able to implement solutions to approximately 70% of the violations. Our study found that a heuristic evaluation using paper-based screen shots of a user interface was expeditious, inexpensive, and straightforward to implement.

  11. Guided-wave tomography imaging plate defects by laser-based ultrasonic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jun Pil; Lim, Ju Young; Cho, Youn Ho [School of Mechanical Engineering, Pusan National University, Pusan (Korea, Republic of)

    2014-12-15

    Contact-guided-wave tests are impractical for investigating specimens with limited accessibility and rough surfaces or complex geometric features. A non-contact setup with a laser-ultrasonic transmitter and receiver is quite attractive for guided-wave inspection. In the present work, we developed a non-contact guided-wave tomography technique using the laser-ultrasonic technique in a plate. A method for Lamb-wave generation and detection in an aluminum plate with a pulsed laser-ultrasonic transmitter and Michelson-interferometer receiver was developed. The defect shape and area in the images obtained using laser scanning, showed good agreement with the actual defect. The proposed approach can be used as a non-contact online inspection and monitoring technique.

  12. FEM model-based investigation of ultrasonic TOFD for notch inspection

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Ziqiao; Yuan, Maodan; Wu, Hu; Zhang, Jianjai; Kim, Hak Joon; Song, Sung Jin [School of Mechanical Engineering, Sungkyunkwan University, Suwon (Korea, Republic of); Kang, Sung Sik [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2014-02-15

    A two-dimensional numerical model based on the finite element method was built to simulate the wave propagation phenomena that occur during the ultrasonic time of flight diffraction (TOFD) process. First, longitudinal-wave TOFD was simulated, and the numerical results agreed well with the theoretical results. Shear-wave TOFD was also investigated because shear waves have higher intensity and resolution. The shear wave propagation was studied using three models with different boundary conditions, and the tip-diffracted shear-to-longitudinal wave was extracted from the A-scan signal difference between the cracked and non-cracked specimens. This signal showed very good agreement between the geometrical and numerical arrival times. The results of this study not only provide better understanding of the diffraction phenomena in TOFD, but also prove the potential of shear-wave TOFD for practical application.

  13. Speckle based configuration for simultaneous in vitro inspection of mechanical contractions of cardiac myocyte cells

    Science.gov (United States)

    Golberg, Mark; Fixler, Dror; Shainberg, Asher; Zlochiver, Sharon; Micó, Vicente; Garcia, Javier; Beiderman, Yevgeny; Zalevsky, Zeev

    2013-04-01

    In this manuscript we propose optical lensless configuration for a remote non-contact measuring of mechanical contractions of vast number of cardiac myocytes. All the myocytes were taken from rats, and the measurements were done in an in vitro mode. The optical method is based on temporal analysis of secondary reflected speckle patterns generated in lensless microscope configuration. The processing involves analyzing the movement and the change in the statistics of the generated secondary speckle patterns that are created on top of the cell culture when it is illuminated by a spot of laser beam. The main advantage of the proposed system is the ability to measure many cells simultaneously (approximately one thousand cells) and to extract the statistical data of their movement at once. The presented experimental results also include investigation the effect of isoproteranol on cells contraction process.

  14. The Real-Time Image Processing Technique Based on DSP

    Institute of Scientific and Technical Information of China (English)

    QI Chang; CHEN Yue-hua; HUANG Tian-shu

    2005-01-01

    This paper proposes a novel real-time image processing technique based on digital singnal processor (DSP). At the aspect of wavelet transform(WT) algorithm, the technique uses algorithm of second generation wavelet transform-lifting scheme WT that has low calculation complexity property for the 2-D image data processing. Since the processing effect of lifting scheme WT for 1-D data is better than the effect of it for 2-D data obviously, this paper proposes a reformative processing method: Transform 2-D image data to 1-D data sequence by linearization method, then process the 1-D data sequence by algorithm of lifting scheme WT. The method changes the image convolution mode,which based on the cross filtering of rows and columns. At the aspect of hardware realization, the technique optimizes the program structure of DSP to exert the operation power with the in-chip memorizer of DSP. The experiment results show that the real-time image processing technique proposed in this paper can meet the real-time requirement of video-image transmitting in the video surveillance system of electric power. So the technique is a feasible and efficient DSP solution.

  15. Face Veins Based MCMT Technique for Personal Identification

    Directory of Open Access Journals (Sweden)

    Kamta Nath Mishra

    2015-08-01

    Full Text Available Face veins based personal identification is a challenging task in the field of identity verification of a person. It is because many other techniques are not identifying the uniqueness of a person in the universe. This research paper finds the uniqueness of a person on the basis of face veins based technique. In this paper five different persons face veins images have been used with different rotation angles (left/right 900 to 2700 and 3150 . For each person, eight different images at different rotations were used and for each of these images the same minimum cost minutiae tree (MCMT is obtained. Here, Prim‟s or Kruskal‟s algorithm is used for finding the MCMT from a minutiae graph. The MCMT is traversed in pre-order to generate the unique string of vertices and edge lengths. We deviated the edge lengths of each MCMT by five pixels in positive and negative directions for robustness testing. It is observed in our experiments that the traversed string which consists of vertices and edge lengths of MCMT is unique for each person and this unique sequence is correctly identifying a person with an accuracy of above 95%. Further, we have compared the performance of our proposed technique with other standard techniques and it is observed that the proposed technique is giving the promising result.

  16. Video multiple watermarking technique based on image interlacing using DWT.

    Science.gov (United States)

    Ibrahim, Mohamed M; Abdel Kader, Neamat S; Zorkany, M

    2014-01-01

    Digital watermarking is one of the important techniques to secure digital media files in the domains of data authentication and copyright protection. In the nonblind watermarking systems, the need of the original host file in the watermark recovery operation makes an overhead over the system resources, doubles memory capacity, and doubles communications bandwidth. In this paper, a robust video multiple watermarking technique is proposed to solve this problem. This technique is based on image interlacing. In this technique, three-level discrete wavelet transform (DWT) is used as a watermark embedding/extracting domain, Arnold transform is used as a watermark encryption/decryption method, and different types of media (gray image, color image, and video) are used as watermarks. The robustness of this technique is tested by applying different types of attacks such as: geometric, noising, format-compression, and image-processing attacks. The simulation results show the effectiveness and good performance of the proposed technique in saving system resources, memory capacity, and communications bandwidth.

  17. Inspection Technique for Green Food Bee Products%绿色食品蜂产品生产检查技术

    Institute of Scientific and Technical Information of China (English)

    唐伟

    2013-01-01

    Bee products are important nutrient products for export.Bee products are high risk products for certification because of the disorderly competition.Green Food certification could make producers obey the standard and produce more safety bee products.This article analyzed the key point for Green Food bee products production and inspection to improve the normalization of inspection and the bee products quality.%蜂产品是我国传统营养食品也是重要出口产品,我国蜂产品由于无序竞争等原因使产品质量风险较高.绿色食品认证作为提高农产品标准化水平的重要抓手,对于提高蜂产品质量有重要作用.本文将对绿色食品蜂产品生产检查关键点进行分析,以进一步提高生产检查的规范性,提高蜂产品质量.

  18. Current and future inspection and maintenance challenges

    Science.gov (United States)

    Bhagat, Pramode K.; Bessette, Lorence; Leonelli, Fredrick

    1996-11-01

    Ever-increasing diversity of civilian aircraft inventory and continued technological advancements in aircraft materials, aircraft flight control equipment, testing equipment, and software methodologies are impacting aircraft inspection and maintenance practices. Current procedures deal mainly with issues related to structural and electrical or electronic integrity to assure continued airworthiness of operational aircraft. Techniques and methodologies for these are widely available, and training needs are well defined. Advances in technology, however, are yielding new and different aircraft, which require more sophisticated electronic instruments for navigation and control.A major issue is the continued reliability and airworthiness of avionics and development of adequate safeguards for these aircraft. Built-in test equipment, maintenance across terminals, and data bases defining inspection needs that are based on operational data, and software integrity, are also rapidly becoming important considerations in aircraft maintenance. In this era of declining funds and personnel resources, a cost-effective approach requires a fresh look at all phases of the current inspection and maintenance practices, including oversight and management. This paper provides a perspective on issues and challenges facing a civilian regulatory agency, specifically, the aircraft maintenance division in the FAA.

  19. Proposing a Wiki-Based Technique for Collaborative Essay Writing

    Directory of Open Access Journals (Sweden)

    Mabel Ortiz Navarrete

    2014-10-01

    Full Text Available This paper aims at proposing a technique for students learning English as a foreign language when they collaboratively write an argumentative essay in a wiki environment. A wiki environment and collaborative work play an important role within the academic writing task. Nevertheless, an appropriate and systematic work assignment is required in order to make use of both. In this paper the proposed technique when writing a collaborative essay mainly attempts to provide the most effective way to enhance equal participation among group members by taking as a base computer mediated collaboration. Within this context, the students’ role is clearly defined and individual and collaborative tasks are explained.

  20. Knowledge based systems advanced concepts, techniques and applications

    CERN Document Server

    1997-01-01

    The field of knowledge-based systems (KBS) has expanded enormously during the last years, and many important techniques and tools are currently available. Applications of KBS range from medicine to engineering and aerospace.This book provides a selected set of state-of-the-art contributions that present advanced techniques, tools and applications. These contributions have been prepared by a group of eminent researchers and professionals in the field.The theoretical topics covered include: knowledge acquisition, machine learning, genetic algorithms, knowledge management and processing under unc

  1. Line impedance estimation using model based identification technique

    DEFF Research Database (Denmark)

    Ciobotaru, Mihai; Agelidis, Vassilios; Teodorescu, Remus

    2011-01-01

    into the operation of the grid-connected power converters. This paper describes a quasi passive method for estimating the line impedance of the distribution electricity network. The method uses the model based identification technique to obtain the resistive and inductive parts of the line impedance. The quasi......The estimation of the line impedance can be used by the control of numerous grid-connected systems, such as active filters, islanding detection techniques, non-linear current controllers, detection of the on/off grid operation mode. Therefore, estimating the line impedance can add extra functions...

  2. Line Search-Based Inverse Lithography Technique for Mask Design

    Directory of Open Access Journals (Sweden)

    Xin Zhao

    2012-01-01

    Full Text Available As feature size is much smaller than the wavelength of illumination source of lithography equipments, resolution enhancement technology (RET has been increasingly relied upon to minimize image distortions. In advanced process nodes, pixelated mask becomes essential for RET to achieve an acceptable resolution. In this paper, we investigate the problem of pixelated binary mask design in a partially coherent imaging system. Similar to previous approaches, the mask design problem is formulated as a nonlinear program and is solved by gradient-based search. Our contributions are four novel techniques to achieve significantly better image quality. First, to transform the original bound-constrained formulation to an unconstrained optimization problem, we propose a new noncyclic transformation of mask variables to replace the wellknown cyclic one. As our transformation is monotonic, it enables a better control in flipping pixels. Second, based on this new transformation, we propose a highly efficient line search-based heuristic technique to solve the resulting unconstrained optimization. Third, to simplify the optimization, instead of using discretization regularization penalty technique, we directly round the optimized gray mask into binary mask for pattern error evaluation. Forth, we introduce a jump technique in order to jump out of local minimum and continue the search.

  3. An Observed Voting System Based On Biometric Technique

    Directory of Open Access Journals (Sweden)

    B. Devikiruba

    2015-08-01

    Full Text Available ABSTRACT This article describes a computational framework which can run almost on every computer connected to an IP based network to study biometric techniques. This paper discusses with a system protecting confidential information puts strong security demands on the identification. Biometry provides us with a user-friendly method for this identification and is becoming a competitor for current identification mechanisms. The experimentation section focuses on biometric verification specifically based on fingerprints. This article should be read as a warning to those thinking of using methods of identification without first examine the technical opportunities for compromising mechanisms and the associated legal consequences. The development is based on the java language that easily improves software packages that is useful to test new control techniques.

  4. A Survey on Statistical Based Single Channel Speech Enhancement Techniques

    Directory of Open Access Journals (Sweden)

    Sunnydayal. V

    2014-11-01

    Full Text Available Speech enhancement is a long standing problem with various applications like hearing aids, automatic recognition and coding of speech signals. Single channel speech enhancement technique is used for enhancement of the speech degraded by additive background noises. The background noise can have an adverse impact on our ability to converse without hindrance or smoothly in very noisy environments, such as busy streets, in a car or cockpit of an airplane. Such type of noises can affect quality and intelligibility of speech. This is a survey paper and its object is to provide an overview of speech enhancement algorithms so that enhance the noisy speech signal which is corrupted by additive noise. The algorithms are mainly based on statistical based approaches. Different estimators are compared. Challenges and Opportunities of speech enhancement are also discussed. This paper helps in choosing the best statistical based technique for speech enhancement

  5. Opencast mine reserve trend inspection system based on ordinary digital camera%基于普通数码相机的露采矿储量动态检测系统

    Institute of Scientific and Technical Information of China (English)

    杨彪; 严丽英; 李浩

    2013-01-01

    For the purpose of rational exploitation of mine reserves and environmental conservation, the government carries out reserve trend inspection on opencast mine. In view of the deficiencies of current work conditions and methods of opencast mine reserve inspection, this paper researches on the key technique of digital close-range photogrammetry on mines based on ordinary digital cameras, and the reserve computation method. As a result, a system of opencast mine reserve trend inspection system is developed, which uses ordinary digital camera calibrated accurately to photograph the mine pits. After taking automatically data processing, such as image distortion correction, relative orientation, absolute orientation, stereo matching, etc. , the 3D reconstruction of the pits is conducted. Together with the previous terrain data, the change of mine reserve is inspected. The practical application of the system remarkably improves the efficiency and accuracy of the reserve inspection.%为促进矿产储量的合理开发和环境保护,国家对露采矿山储量实行动态检测.本文针对露采矿山储量检测工作现状和现有方法的不足,研究基于普通数码相机的矿山数字近景摄影测量关键技术和储量计算方法,并据此开发了露采矿山储量动态检测系统.系统采用经过标定的普通数码相机对矿山宕口摄影,通过影像畸变校正、相对定向、绝对定向、影像匹配等自动化处理,重建矿山开采宕口三维模型,再根据前期地形数据,计算矿山储量变化.系统的实际应用显著提高了储量检测的效率和精度.

  6. 基于GPIB总线的机载校验平台射频组件%The RF component of airborne inspection platform based on GPIB

    Institute of Scientific and Technical Information of China (English)

    都伟伟; 王成林; 李娜

    2012-01-01

    为实现机载飞行校验平台射频通路的自动切换,提出了一种基于GPIB总线的天线控制单元(antenna control unit)的设计.天线控制单元是机载校验平台的重要射频组件,主要用于控制前端天线接收到的射频信号或者航空标准信号源产生的信号与对应接收机的准确自动化的连通.上位机选定不同的校验科目,通过GPIB总线发送命令至天线控制单元,实现相应射频通路的连通和切换.经过测试,可成功实现不同科目的校验,已经应用于国内首套自主研发先进机载飞行校验平台中.%In order to fulfill the automatic switching of RF signal path in airborne flight inspection platform,a design of antenna control unit based on general-purpose interface bus is presented in this paper. Antenna control unit (ACU) is a very critical radio frequency component of airborne inspection platform. It is used for controlling the automatic connecting from RF signals received by front-end antennas or generated by standard aeronautic signal generators to relevant receivers accurately. The upper computers choose different inspection subjects and send messages to ACU by means of GPIB, and then realize connecting and switching of relevant RF signal path. After testing, it has already achieved inspection of different subjects and been applied in the first advanced airborne flight inspection platform designed and developed by China.

  7. Safety Justification of Software Systems. Software Based Safety Systems. Regulatory Inspection Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Dahll, Gustav (OECD Halden Project, Halden (NO)); Liwaang, Bo (Swedish Nuclear Power Inspectorate, Stockholm (Sweden)); Wainwright, Norman (Wainwright Safety Advice (GB))

    2006-07-01

    The introduction of new software based technology in the safety systems in nuclear power plants also makes it necessary to develop new strategies for regulatory review and assessment of these new systems that is more focused on reviewing the processes at the different phases in design phases during the system life cycle. It is a general requirement that the licensee shall perform different kinds of reviews. From a regulatory point of view it is more cost effective to assess that the design activities at the suppliers and the review activities within the development project are performed with good quality. But the change from more technical reviews over to the development process oriented approach also cause problems. When reviewing development and quality aspects there are no 'hard facts' that can be judged against some specified criteria, the issues are more 'soft' and are more to build up structure of arguments and evidences that the requirements are met. The regulatory review strategy must therefore change to follow the development process over the whole life cycle from concept phase until installation and operation. Even if we know what factors that is of interest we need some guidance on how to interpret and judge the information.For that purpose SKl started research activities in this area at the end of the 1990s. In the first phase, in co-operation with Gustav Dahll at the Halden project, a life cycle model was selected. For the different phases a qualitative influence net was constructed of the type that is used in Bayesian Believe Network together with a discussion on different issues involved. In the second phase of the research work, in co-operation with Norman Wainwright, a former NII inspector, information from a selection of the most important sources as guidelines, IAEA and EC reports etc, was mapped into the influence net structure (the total list on used sources are in the report). The result is presented in the form of

  8. RANKINGTHEREFACTORING TECHNIQUES BASED ON THE INTERNAL QUALITY ATTRIBUTES

    Directory of Open Access Journals (Sweden)

    Sultan Alshehri

    2014-01-01

    Full Text Available The analytic hierarchy process (AHP has been applied in many fields and especially to complex engineering problems and applications. The AHP is capable of structuring decision problems and finding mathematically determined judgments built on knowledge and experience. This suggests that AHP should prove useful in agile software development where complex decisions occur routinely. In this paper, the AHP is used to rank the refactoring techniques based on the internal code quality attributes. XP encourages applying the refactoring where the code smells bad. However, refactoring may consume more time and efforts.So, to maximize the benefits of the refactoring in less time and effort, AHP has been applied to achieve this purpose. It was found that ranking the refactoring techniques helped the XP team to focus on the technique that improve the code and the XP development process in general.

  9. Multivariate discrimination technique based on the Bayesian theory

    Institute of Scientific and Technical Information of China (English)

    JIN Ping; PAN Chang-zhou; XIAO Wei-guo

    2007-01-01

    A multivariate discrimination technique was established based on the Bayesian theory. Using this technique, P/S ratios of different types (e.g., Pn/Sn, Pn/Lg, Pg/Sn or Pg/Lg) measured within different frequency bands and from different stations were combined together to discriminate seismic events in Central Asia. Major advantages of the Bayesian approach are that the probability to be an explosion for any unknown event can be directly calculated given the measurements of a group of discriminants, and at the same time correlations among these discriminants can be fully taken into account. It was proved theoretically that the Bayesian technique would be optimal and its discriminating performance would be better than that of any individual discriminant as well as better than that yielded by the linear combination approach ignoring correlations among discriminants. This conclusion was also validated in this paper by applying the Bayesian approach to the above-mentioned observed data.

  10. 3D laser inspection of fuel assembly grid spacers for nuclear reactors based on diffractive optical elements

    Science.gov (United States)

    Finogenov, L. V.; Lemeshko, Yu A.; Zav'yalov, P. S.; Chugui, Yu V.

    2007-06-01

    Ensuring the safety and high operation reliability of nuclear reactors takes 100% inspection of geometrical parameters of fuel assemblies, which include the grid spacers performed as a cellular structure with fuel elements. The required grid spacer geometry of assembly in the transverse and longitudinal cross sections is extremely important for maintaining the necessary heat regime. A universal method for 3D grid spacer inspection using a diffractive optical element (DOE), which generates as the structural illumination a multiple-ring pattern on the inner surface of a grid spacer cell, is investigated. Using some DOEs one can inspect the nomenclature of all produced grids. A special objective has been developed for forming the inner surface cell image. The problems of diffractive elements synthesis, projecting optics calculation, adjusting methods as well as calibration of the experimental measuring system are considered. The algorithms for image processing for different constructive elements of grids (cell, channel hole, outer grid spacer rim) and the experimental results are presented.

  11. An Active Endoscopy Robotic System for Direct Tracheal Inspection

    Institute of Scientific and Technical Information of China (English)

    YU Lian-zhi; YAN Guo-zheng; MA Guan-ying; ZAN Peng

    2007-01-01

    The development of active endoscopy techniques is one important area of medical robot. This paper designed a new flexible and active endoscopy robotic system for direct tracheal inspection. The mobile mechanism of the robot is based on the inchworm movement actuated by pneumatic rubber actuator. There are five air chambers controlled independently, by adjusting pressures in air chambers, the robot can move in a straight mode or in a bending mode. The inspection sensors and some therapy surgery tools can be equipped in the front of the robot.The prototype was made and its mechanical characteristics were analyzed. The robot could move smoothly in a small plastic tube, and the robot is respectable to be used for inspection in human trachea directly.

  12. MEMS-Based Power Generation Techniques for Implantable Biosensing Applications

    Directory of Open Access Journals (Sweden)

    Jonathan Lueke

    2011-01-01

    Full Text Available Implantable biosensing is attractive for both medical monitoring and diagnostic applications. It is possible to monitor phenomena such as physical loads on joints or implants, vital signs, or osseointegration in vivo and in real time. Microelectromechanical (MEMS-based generation techniques can allow for the autonomous operation of implantable biosensors by generating electrical power to replace or supplement existing battery-based power systems. By supplementing existing battery-based power systems for implantable biosensors, the operational lifetime of the sensor is increased. In addition, the potential for a greater amount of available power allows additional components to be added to the biosensing module, such as computational and wireless and components, improving functionality and performance of the biosensor. Photovoltaic, thermovoltaic, micro fuel cell, electrostatic, electromagnetic, and piezoelectric based generation schemes are evaluated in this paper for applicability for implantable biosensing. MEMS-based generation techniques that harvest ambient energy, such as vibration, are much better suited for implantable biosensing applications than fuel-based approaches, producing up to milliwatts of electrical power. High power density MEMS-based approaches, such as piezoelectric and electromagnetic schemes, allow for supplemental and replacement power schemes for biosensing applications to improve device capabilities and performance. In addition, this may allow for the biosensor to be further miniaturized, reducing the need for relatively large batteries with respect to device size. This would cause the implanted biosensor to be less invasive, increasing the quality of care received by the patient.

  13. Container inspection in the port container terminal by using 14 MeV neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Valkovic, Vladivoj [Institute Ruder Boskovic, Zagreb (Croatia); Kvinticka 62, Zagreb (Croatia); Sudac, Davorin; Nad, Karlo; Obhodas, Jasmina [Ruder Boskovic Institute, Bijenicka c.54, Zagreb (Croatia)

    2015-07-01

    A proposal for an autonomous and flexible ship container inspection system is presented. This could be accomplished by the incorporation of inspection system on the container transportation devices (straddle carriers, yard gentry cranes automated guided vehicles, trailers). This configuration is terminal specific and it will be decided by container terminal operator. In such a way no part of port operational area will be used for inspection. The inspection scenario will include container transfer from ship to transportation device with inspection unit mounted on it, inspection during container movement to the container location. A neutron generator without associated alpha particle detection will be used. This will allow the use of higher neutron intensity (5x10{sup 9} - 10{sup 10} n/s in 4π). The inspected container will be stationary in the 'inspection position' on the transportation device while the 'inspection unit' will move along its side. Following analytical methods will be used simultaneously: neutron radiography, X-ray radiography, neutron activation analysis, (n,γ) and (n,n'γ) reactions, neutron absorption, and scattering, X-ray backscattering, Neutron techniques will take the advantage of using 'smart collimators' for neutrons and gammas, both emitted and detected. The inspected voxel will be defined by intersections/union of neutron generator and detectors solid angles. The container inspection protocol will be based on identification of discrepancies between its cargo manifest and its elemental 'fingerprint' and radiography profiles. In addition, the information on container weight will be obtained during the container transport and foreseen screening from the measurement of density of material in the container. (authors)

  14. An Efficient Image Compression Technique Based on Arithmetic Coding

    Directory of Open Access Journals (Sweden)

    Prof. Rajendra Kumar Patel

    2012-12-01

    Full Text Available The rapid growth of digital imaging applications, including desktop publishing, multimedia, teleconferencing, and high visual definition has increased the need for effective and standardized image compression techniques. Digital Images play a very important role for describing the detailed information. The key obstacle for many applications is the vast amount of data required to represent a digital image directly. The various processes of digitizing the images to obtain it in the best quality for the more clear and accurate information leads to the requirement of more storage space and better storage and accessing mechanism in the form of hardware or software. In this paper we concentrate mainly on the above flaw so that we reduce the space with best quality image compression. State-ofthe-art techniques can compress typical images from 1/10 to 1/50 their uncompressed size without visibly affecting image quality. From our study I observe that there is a need of good image compression technique which provides better reduction technique in terms of storage and quality. Arithmetic coding is the best way to reducing encoding data. So in this paper we propose arithmetic coding with walsh transformation based image compression technique which is an efficient way of reduction

  15. Waste inspection tomography (WIT)

    Energy Technology Data Exchange (ETDEWEB)

    Bernardi, R.T. [Bio-Imaging Research, Inc., Lincolnshire, IL (United States)

    1995-10-01

    Waste Inspection Tomography (WIT) provides mobile semi-trailer mounted nondestructive examination (NDE) and assay (NDA) for nuclear waste drum characterization. WIT uses various computed tomography (CT) methods for both NDE and NDA of nuclear waste drums. Low level waste (LLW), transuranic (TRU), and mixed radioactive waste can be inspected and characterized without opening the drums. With externally transmitted x-ray NDE techniques, WIT has the ability to identify high density waste materials like heavy metals, define drum contents in two- and three-dimensional space, quantify free liquid volumes through density and x-ray attenuation coefficient discrimination, and measure drum wall thickness. With waste emitting gamma-ray NDA techniques, WIT can locate gamma emitting radioactive sources in two- and three-dimensional space, identify gamma emitting, isotopic species, identify the external activity levels of emitting gamma-ray sources, correct for waste matrix attenuation, provide internal activity approximations, and provide the data needed for waste classification as LLW or TRU.

  16. SMS Spam Filtering Technique Based on Artificial Immune System

    Directory of Open Access Journals (Sweden)

    Tarek M Mahmoud

    2012-03-01

    Full Text Available The Short Message Service (SMS have an important economic impact for end users and service providers. Spam is a serious universal problem that causes problems for almost all users. Several studies have been presented, including implementations of spam filters that prevent spam from reaching their destination. Nave Bayesian algorithm is one of the most effective approaches used in filtering techniques. The computational power of smart phones are increasing, making increasingly possible to perform spam filtering at these devices as a mobile agent application, leading to better personalization and effectiveness. The challenge of filtering SMS spam is that the short messages often consist of few words composed of abbreviations and idioms. In this paper, we propose an anti-spam technique based on Artificial Immune System (AIS for filtering SMS spam messages. The proposed technique utilizes a set of some features that can be used as inputs to spam detection model. The idea is to classify message using trained dataset that contains Phone Numbers, Spam Words, and Detectors. Our proposed technique utilizes a double collection of bulk SMS messages Spam and Ham in the training process. We state a set of stages that help us to build dataset such as tokenizer, stop word filter, and training process. Experimental results presented in this paper are based on iPhone Operating System (iOS. The results applied to the testing messages show that the proposed system can classify the SMS spam and ham with accurate compared with Nave Bayesian algorithm.

  17. Earthquake Analysis of Structure by Base Isolation Technique in SAP

    Directory of Open Access Journals (Sweden)

    T. Subramani

    2014-06-01

    Full Text Available This paper presents an overview of the present state of base isolation techniques with special emphasis and a brief on other techniques developed world over for mitigating earthquake forces on the structures. The dynamic analysis procedure for isolated structures is briefly explained. The provisions of FEMA 450 for base isolated structures are highlighted. The effects of base isolation on structures located on soft soils and near active faults are given in brief. Simple case study on natural base isolation using naturally available soils is presented. Also, the future areas of research are indicated. Earthquakes are one of nature IS greatest hazards; throughout historic time they have caused significant loss offline and severe damage to property, especially to man-made structures. On the other hand, earthquakes provide architects and engineers with a number of important design criteria foreign to the normal design process. From well established procedures reviewed by many researchers, seismic isolation may be used to provide an effective solution for a wide range of seismic design problems. The application of the base isolation techniques to protect structures against damage from earthquake attacks has been considered as one of the most effective approaches and has gained increasing acceptance during the last two decades. This is because base isolation limits the effects of the earthquake attack, a flexible base largely decoupling the structure from the ground motion, and the structural response accelerations are usually less than the ground acceleration. In general, the increase of additional viscous damping in the structure may reduce displacement and acceleration responses of the structure. This study also seeks to evaluate the effects of additional damping on the seismic response when compared with structures without additional damping for the different ground motions.

  18. Finding Within Cluster Dense Regions Using Distance Based Technique

    Directory of Open Access Journals (Sweden)

    Wesam Ashour

    2012-03-01

    Full Text Available One of the main categories in Data Clustering is density based clustering. Density based clustering techniques like DBSCAN are attractive because they can find arbitrary shaped clusters along with noisy outlier. The main weakness of the traditional density based algorithms like DBSCAN is clustering the different density level data sets. DBSCAN calculations done according to given parameters applied to all points in a data set, while densities of the data set clusters may be totally different. The proposed algorithm overcomes this weakness of the traditional density based algorithms. The algorithm starts with partitioning the data within a cluster to units based on a user parameter and compute the density for each unit separately. Consequently, the algorithm compares the results and merges neighboring units with closer approximate density values to become a new cluster. The experimental results of the simulation show that the proposed algorithm gives good results in finding clusters for different density cluster data set.

  19. 在用医疗器械的检验技术要求%Requirements on the Inspection Technique of In-Use Medical Devices

    Institute of Scientific and Technical Information of China (English)

    李澍; 王权; 张艳丽; 任海萍

    2014-01-01

    This paper ifrstly introduced the overseas quality control status of medical devices, and then analyzed the current situation and problems of medical devices inspection in China from the perspectives of safety, basic performance, lifecycle and standardized instruments checkout vehicles. Finally, corresponding suggestions were put forward in order to improve the management and quality control levels of in-use medical devices.%本文首先介绍了国外医疗器械质量控制现状,然后从安全性、基本性能、生命周期、标准化的器械检测车等四个方面对我国医疗器械检验现状及问题进行分析,并提出相应的意见,以期提高在用医疗器械管理和质量控制水平。

  20. Gabor-based fusion technique for Optical Coherence Microscopy.

    Science.gov (United States)

    Rolland, Jannick P; Meemon, Panomsak; Murali, Supraja; Thompson, Kevin P; Lee, Kye-sung

    2010-02-15

    We recently reported on an Optical Coherence Microscopy technique, whose innovation intrinsically builds on a recently reported - 2 microm invariant lateral resolution by design throughout a 2 mm cubic full-field of view - liquid-lens-based dynamic focusing optical probe [Murali et al., Optics Letters 34, 145-147, 2009]. We shall report in this paper on the image acquisition enabled by this optical probe when combined with an automatic data fusion method developed and described here to produce an in-focus high resolution image throughout the imaging depth of the sample. An African frog tadpole (Xenopus laevis) was imaged with the novel probe and the Gabor-based fusion technique, demonstrating subcellular resolution in a 0.5 mm (lateral) x 0.5 mm (axial) without the need, for the first time, for x-y translation stages, depth scanning, high-cost adaptive optics, or manual intervention. In vivo images of human skin are also presented.

  1. Clustering economies based on multiple criteria decision making techniques

    OpenAIRE

    2011-01-01

    One of the primary concerns on many countries is to determine different important factors affecting economic growth. In this paper, we study some factors such as unemployment rate, inflation ratio, population growth, average annual income, etc to cluster different countries. The proposed model of this paper uses analytical hierarchy process (AHP) to prioritize the criteria and then uses a K-mean technique to cluster 59 countries based on the ranked criteria into four groups. The first group i...

  2. High-Accurate, Physics-Based Wake Simulation Techniques

    Science.gov (United States)

    2015-01-27

    physically accurate problem as well as to show that the sensor can account for artificial viscosity where needed but not overload the problem and ”wash out...code) 1/27/2015 Final Technical Report 02/25/10 - 08/31/14 High-Accurate, Physics -Based Wake Simulation Techniques N00014-10-C-0190 Andrew Shelton...code was developed that utilizes the discontinuous Galerkin method to solve the Euler equations while utilizing a modal artificial viscosity sensor

  3. Optimal inspection and Repair Strategies for Structural Systems

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Faber, M. H.

    1992-01-01

    A model for reliability-based repair and maintenance strategies of structural systems is described. The total expected costs in the lifetime of the structure are minimized with the number of inspections, the number and positions of the inspected points, the inspection efforts, the repair criteria...... to be inspected and to select the location of the points to be inspected. It is shown how information obtained through inspections and through the periods of normal operating of the structure can be used to update the inspection and maintenance planning. Finally, a small example is given illustrating...

  4. NEW VERSATILE CAMERA CALIBRATION TECHNIQUE BASED ON LINEAR RECTIFICATION

    Institute of Scientific and Technical Information of China (English)

    Pan Feng; Wang Xuanyin

    2004-01-01

    A new versatile camera calibration technique for machine vision using off-the-shelf cameras is described. Aimed at the large distortion of the off-the-shelf cameras, a new camera distortion rectification technology based on line-rectification is proposed. A full-camera-distortion model is introduced and a linear algorithm is provided to obtain the solution. After the camera rectification intrinsic and extrinsic parameters are obtained based on the relationship between the homograph and absolute conic. This technology needs neither a high-accuracy three-dimensional calibration block, nor a complicated translation or rotation platform. Both simulations and experiments show that this method is effective and robust.

  5. User Identification Detector Based on Power of R Technique

    Institute of Scientific and Technical Information of China (English)

    WANG Chun-jiang; YU Quan; LIU Yuan-an

    2005-01-01

    To avoid the inaccurate estimation of the active user's number and the corresponding performance degradation, a novel POR-based User Identification Detector (UID) is proposed for the Code Division Multiple Access (CDMA) systems. The new detector adopts the Power of R (POR) technique and the Multiple Signal Classification (MUSIC) method, which does not require the estimation of active users' number, and obtains lower false alarm probability than the subspace-based UID in the multipath channels. However, from our analysis, increasing the order m does not improve the performance. Therefore, when m is one, the performance of the new detector is maximal.

  6. Comparing Four Touch-Based Interaction Techniques for an Image-Based Audience Response System

    NARCIS (Netherlands)

    Jorritsma, Wiard; Prins, Jonatan T.; van Ooijen, Peter M. A.

    2015-01-01

    This study aimed to determine the most appropriate touch-based interaction technique for I2Vote, an image-based audience response system for radiology education in which users need to accurately mark a target on a medical image. Four plausible techniques were identified: land-on, take-off, zoom-poin

  7. A Different Web-Based Geocoding Service Using Fuzzy Techniques

    Science.gov (United States)

    Pahlavani, P.; Abbaspour, R. A.; Zare Zadiny, A.

    2015-12-01

    Geocoding - the process of finding position based on descriptive data such as address or postal code - is considered as one of the most commonly used spatial analyses. Many online map providers such as Google Maps, Bing Maps and Yahoo Maps present geocoding as one of their basic capabilities. Despite the diversity of geocoding services, users usually face some limitations when they use available online geocoding services. In existing geocoding services, proximity and nearness concept is not modelled appropriately as well as these services search address only by address matching based on descriptive data. In addition there are also some limitations in display searching results. Resolving these limitations can enhance efficiency of the existing geocoding services. This paper proposes the idea of integrating fuzzy technique with geocoding process to resolve these limitations. In order to implement the proposed method, a web-based system is designed. In proposed method, nearness to places is defined by fuzzy membership functions and multiple fuzzy distance maps are created. Then these fuzzy distance maps are integrated using fuzzy overlay technique for obtain the results. Proposed methods provides different capabilities for users such as ability to search multi-part addresses, searching places based on their location, non-point representation of results as well as displaying search results based on their priority.

  8. A DIFFERENT WEB-BASED GEOCODING SERVICE USING FUZZY TECHNIQUES

    Directory of Open Access Journals (Sweden)

    P. Pahlavani

    2015-12-01

    Full Text Available Geocoding – the process of finding position based on descriptive data such as address or postal code - is considered as one of the most commonly used spatial analyses. Many online map providers such as Google Maps, Bing Maps and Yahoo Maps present geocoding as one of their basic capabilities. Despite the diversity of geocoding services, users usually face some limitations when they use available online geocoding services. In existing geocoding services, proximity and nearness concept is not modelled appropriately as well as these services search address only by address matching based on descriptive data. In addition there are also some limitations in display searching results. Resolving these limitations can enhance efficiency of the existing geocoding services. This paper proposes the idea of integrating fuzzy technique with geocoding process to resolve these limitations. In order to implement the proposed method, a web-based system is designed. In proposed method, nearness to places is defined by fuzzy membership functions and multiple fuzzy distance maps are created. Then these fuzzy distance maps are integrated using fuzzy overlay technique for obtain the results. Proposed methods provides different capabilities for users such as ability to search multi-part addresses, searching places based on their location, non-point representation of results as well as displaying search results based on their priority.

  9. Fabric Defect Detection Technique Based on Two-double Neural Network

    Institute of Scientific and Technical Information of China (English)

    XIE Chun-ping; XU Bo-jun; CHEN Jun-jie

    2008-01-01

    This paper introduces the identification of the defects on the fabric by using two-double neural network and wavelet analysis. The purpose is to fit for the automatic cloth inspection system and to avoid the disadvantages of traditional human inspection. Firstly, training the normal fabric to acquire its characteristics and then using the BP neural network to tell the normal fabric apart from the one with defects. Secondly, doing the two-dimensional discrete wavelet transformation based on the image of the defects, then wiping off the proper characteristics of the fabric, and identifying the defects utilizing the trained BP neural network. It is proved that this method is of high speed and accuracy. It comes up to the requirement of automatic cloth inspection.

  10. Performance Based Novel Techniques for Semantic Web Mining

    Directory of Open Access Journals (Sweden)

    Mahendra Thakur

    2012-01-01

    Full Text Available The explosive growth in the size and use of the World Wide Web continuously creates new great challenges and needs. The need for predicting the users preferences in order to expedite and improve the browsing though a site can be achieved through personalizing of the websites. Most of the research efforts in web personalization correspond to the evolution of extensive research in web usage mining, i.e. the exploitation of the navigational patterns of the web site visitors. When a personalization system relies solely on usage-based results, however, valuable information conceptually related to what is finally recommended may be missed. Moreover, the structural properties of the web site are often disregarded. In this paper, we propose novel techniques that use the content semantics and the structural properties of a web site in order to improve the effectiveness of web personalization. In the first part of our work we present standing for Semantic Web Personalization, a personalization system that integrates usage data with content semantics, expressed in ontology terms, in order to compute semantically enhanced navigational patterns and effectively generate useful recommendations. To the best of our knowledge, our proposed technique is the only semantic web personalization system that may be used by non-semantic web sites. In the second part of our work, we present a novel approach for enhancing the quality of recommendations based on the underlying structure of a web site. We introduce UPR (Usage-based PageRank, a PageRank-style algorithm that relies on the recorded usage data and link analysis techniques. Overall, we demonstrate that our proposed hybrid personalization framework results in more objective and representative predictions than existing techniques.

  11. Restaurant inspection frequency and food safety compliance.

    Science.gov (United States)

    Newbold, K Bruce; McKeary, Marie; Hart, Robert; Hall, Robert

    2008-11-01

    Although food premises are regularly inspected, little information is available on the effect of inspections on compliance records, particularly with respect to the impact of the frequency of inspection on compliance. The following presents the outcome of a study designed to assess the impact of increased inspection frequency on compliance measures in Hamilton, Ontario, in the absence of any other changes to food handler/safety programs or legislation. High-risk food inspection premises were randomly assigned three, four, or five inspections per year. Results indicate that no statistical difference existed in outcome measures based on frequency of inspection. When premises were grouped based on the average time between inspections, premises with greater time between inspections scored better compliance measures relative to premises that were inspected more frequently. The study was also unique for the level of consultation and collaboration sought from the public health inspectors (PHIs) assigned to the Food Safety Program. Their knowledge and experience with respect to the critical variables associated with compliance were a complementary component to the literature review conducted by the research team.

  12. Regression based peak load forecasting using a transformation technique

    Energy Technology Data Exchange (ETDEWEB)

    Haida, Takeshi; Muto, Shoichi (Tokyo Electric Power Co. (Japan). Computer and Communication Research Center)

    1994-11-01

    This paper presents a regression based daily peak load forecasting method with a transformation technique. In order to forecast the load precisely through a year, the authors should consider seasonal load change, annual load growth and the latest daily load change. To deal with these characteristics in the load forecasting, a transformation technique is presented. This technique consists of a transformation function with translation and reflection methods. The transformation function is estimated with the previous year's data points, in order that the function converts the data points into a set of new data points with preserving the shape of temperature-load relationships in the previous year. Then, the function is slightly translated so that the transformed data points will fit the shape of temperature-load relationships in the year. Finally, multivariate regression analysis with the latest daily loads and weather observations estimates the forecasting model. Large forecasting errors caused by the weather-load nonlinear characteristic in the transitional seasons such as spring and fall are reduced. Performance of the technique which is verified with simulations on actual load data of Tokyo Electric Power Company is also described.

  13. Noninvasive in vivo glucose sensing using an iris based technique

    Science.gov (United States)

    Webb, Anthony J.; Cameron, Brent D.

    2011-03-01

    Physiological glucose monitoring is important aspect in the treatment of individuals afflicted with diabetes mellitus. Although invasive techniques for glucose monitoring are widely available, it would be very beneficial to make such measurements in a noninvasive manner. In this study, a New Zealand White (NZW) rabbit animal model was utilized to evaluate a developed iris-based imaging technique for the in vivo measurement of physiological glucose concentration. The animals were anesthetized with isoflurane and an insulin/dextrose protocol was used to control blood glucose concentration. To further help restrict eye movement, a developed ocular fixation device was used. During the experimental time frame, near infrared illuminated iris images were acquired along with corresponding discrete blood glucose measurements taken with a handheld glucometer. Calibration was performed using an image based Partial Least Squares (PLS) technique. Independent validation was also performed to assess model performance along with Clarke Error Grid Analysis (CEGA). Initial validation results were promising and show that a high percentage of the predicted glucose concentrations are within 20% of the reference values.

  14. IMAGE SEGMENTATION BASED ON MARKOV RANDOM FIELD AND WATERSHED TECHNIQUES

    Institute of Scientific and Technical Information of China (English)

    纳瑟; 刘重庆

    2002-01-01

    This paper presented a method that incorporates Markov Random Field(MRF), watershed segmentation and merging techniques for performing image segmentation and edge detection tasks. MRF is used to obtain an initial estimate of x regions in the image under process where in MRF model, gray level x, at pixel location i, in an image X, depends on the gray levels of neighboring pixels. The process needs an initial segmented result. An initial segmentation is got based on K-means clustering technique and the minimum distance, then the region process in modeled by MRF to obtain an image contains different intensity regions. Starting from this we calculate the gradient values of that image and then employ a watershed technique. When using MRF method it obtains an image that has different intensity regions and has all the edge and region information, then it improves the segmentation result by superimpose closed and an accurate boundary of each region using watershed algorithm. After all pixels of the segmented regions have been processed, a map of primitive region with edges is generated. Finally, a merge process based on averaged mean values is employed. The final segmentation and edge detection result is one closed boundary per actual region in the image.

  15. Computer vision technology in log volume inspection

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Log volume inspection is very important in forestry research and paper making engineering. This paper proposed a novel approach based on computer vision technology to cope with log volume inspection. The needed hardware system was analyzed and the details of the inspection algorithms were given. A fuzzy entropy based on image enhancement algorithm was presented for enhancing the image of the cross-section of log. In many practical applications the cross-section is often partially invisible, and this is the major obstacle for correct inspection. To solve this problem, a robust Hausdorff distance method was proposed to recover the whole cross-section. Experiment results showed that this method was efficient.

  16. 带包覆层铁磁性管道腐蚀脉冲涡流检测技术%Pulsed Eddy Current Inspection Technique in for Corrosion under Insulation in Ferromagnetic Tubes

    Institute of Scientific and Technical Information of China (English)

    康小伟; 付跃文

    2011-01-01

    In this paper, we applied pulsed eddy current(PEC} inspection technique to detect ferromagnetic tubes corrosion under insulation. By detecting corrosion of different thickness insulation and different defect areas and deepness, variation of detection sensitivity was analyzed. It was proved that as for corrosion defect with a large area, pulsed eddy current had a very good ability in testing under appropriate inspection parameters, even with a thick insulation.%应用脉冲涡流检测技术,对带包覆层的铁磁性管道腐蚀进行了检测。对不同厚度的包覆层、不同面积和深度的腐蚀缺陷进行了试验,分析检测灵敏度的变化。试验结果表明,对于较大面积的腐蚀缺陷,即使包覆层较厚,在合适的检测参数下,脉冲涡流也具有很好的检测能力。

  17. User`s guide for the Augmented Computer Exercise for Inspection Training (ACE-IT) software

    Energy Technology Data Exchange (ETDEWEB)

    Dobranich, P.R. [Sandia National Labs., Albuquerque, NM (United States). Cooperative Monitoring Center and Regional Security; Horak, K.E.; Hagan, D.; Evanko, D.; Nelson, J.; Ryder, C.; Hedlund, D. [Ogden Environmental and Energy Services, Inc., Albuquerque, NM (United States)

    1997-09-01

    The on-site inspection provisions in many current and proposed arms control agreements require extensive preparation and training on the part of both the Inspection Teams (inspectors) and Inspected Parties (host). Current training techniques include table-top inspections and practice inspections. The Augmented Computer Exercise for Inspection Training (ACE-IT), an interactive computer training tool, increases the utility of table-top inspections. ACE-IT has been designed to provide training for challenge inspections under the Chemical Weapons Convention (CWC); however, this training tool can be modified for other inspection regimes. Although ACE-IT provides training from notification of an inspection through post-inspection activities, the primary emphasis of ACE-IT is in the inspection itself--particularly with the concept of managed access. ACE-IT also demonstrates how inspection provisions impact compliance determination and the protection of sensitive information. This User`s Guide describes the use of the ACE-IT training software.

  18. Design of an Infrared Imaging System for Robotic Inspection of Gas Leaks in Industrial Environments

    Directory of Open Access Journals (Sweden)

    Miguel A. Rodriguez-Conejo

    2015-03-01

    The mobile platform where the gas sensing system is going to be implemented is a robot called TurtleBot. The control of the mobile base and of the inspection device is integrated in ROS architecture. The exploration system is based on the technique of Simultaneous Localization and Mapping (SLAM that makes it possible to locate the gas leak in the map.

  19. New modulation-based watermarking technique for video

    Science.gov (United States)

    Lemma, Aweke; van der Veen, Michiel; Celik, Mehmet

    2006-02-01

    Successful watermarking algorithms have already been developed for various applications ranging from meta-data tagging to forensic tracking. Nevertheless, it is commendable to develop alternative watermarking techniques that provide a broader basis for meeting emerging services, usage models and security threats. To this end, we propose a new multiplicative watermarking technique for video, which is based on the principles of our successful MASK audio watermark. Audio-MASK has embedded the watermark by modulating the short-time envelope of the audio signal and performed detection using a simple envelope detector followed by a SPOMF (symmetrical phase-only matched filter). Video-MASK takes a similar approach and modulates the image luminance envelope. In addition, it incorporates a simple model to account for the luminance sensitivity of the HVS (human visual system). Preliminary tests show algorithms transparency and robustness to lossy compression.

  20. Novel synchrotron based techniques for characterization of energy materials

    Energy Technology Data Exchange (ETDEWEB)

    Poulsen, H.F.; Nielsen, S.F.; Olsen, U.L.; Schmidt, S. (Risoe DTU, Materials Research Dept., Roskilde (Denmark)); Wright, J. (European Synchrotron Radiation Facility, Grenoble Cedex (France))

    2008-10-15

    Two synchrotron techniques are reviewed, both based on the use of high energy x-rays, and both applicable to in situ studies of bulk materials. Firstly, 3DXRD microscopy, which enables 3D characterization of the position, morphology, phase, elastic strain and crystallographic orientation of the individual embedded grains in polycrystalline specimens. In favourable cases, hundreds of grains can be studied simultaneously during processing. Secondly, plastic strain tomography: a unique method for determining the plastic strain field within materials during processing the potential applications of these techniques for basic and applied studies of four types of energy materials are discussed: polymer composites for wind turbines, solid oxide fuel cells, hydrogen storage materials and superconducting tapes. Furthermore, progress on new detectors aiming at improving the spatial and temporal resolution of such measurements is described. (au)

  1. An Improved Face Recognition Technique Based on Modular LPCA Approach

    Directory of Open Access Journals (Sweden)

    Mathu S.S. Kumar

    2011-01-01

    Full Text Available Problem statement: A face identification algorithm based on modular localized variation by Eigen Subspace technique, also called modular localized principal component analysis, is presented in this study. Approach: The face imagery was partitioned into smaller sub-divisions from a predefined neighborhood and they were ultimately fused to acquire many sets of features. Since a few of the normal facial features of an individual do not differ even when the pose and illumination may differ, the proposed method manages these variations. Results: The proposed feature selection module has significantly, enhanced the identification precision using standard face databases when compared to conservative and modular PCA techniques. Conclusion: The proposed algorithm, when related with conservative PCA algorithm and modular PCA, has enhanced recognition accuracy for face imagery with illumination, expression and pose variations.

  2. Efficient Identification Using a Prime-Feature-Based Technique

    DEFF Research Database (Denmark)

    Hussain, Dil Muhammad Akbar; Haq, Shaiq A.; Valente, Andrea

    2011-01-01

    Identification of authorized train drivers through biometrics is a growing area of interest in locomotive radio remote control systems. The existing technique of password authentication is not very reliable and potentially unauthorized personnel may also operate the system on behalf of the operator....... Fingerprint identification system, implemented on PC/104 based real-time systems, can accurately identify the operator. Traditionally, the uniqueness of a fingerprint is determined by the overall pattern of ridges and valleys as well as the local ridge anomalies e.g., a ridge bifurcation or a ridge ending...... in this paper. The technique involves identifying the most prominent feature of the fingerprint and searching only for that feature in the database to expedite the search process. The proposed architect provides efficient matching process and indexing feature for identification is unique....

  3. New Intellectual Economized Technique on Electricity Based on DSP

    Institute of Scientific and Technical Information of China (English)

    Chang-ming LI; Tao JI; Ying SUN

    2010-01-01

    In order to resolve the problem of the unbalanced threephase and unstable voltage,intellectual economized technique on electricity based on electromagnetic regulation and control is proposed in this paper.We choose the TMS320LF2407A as the control chip and stepper motor as the executing agency.The equipment controls the movable contact reaching to the assigned position on the magnetic coil quickly and accurately,and outputs the sine-wave voltage steadily along with the network voltage variation though the fuzzy Porpornonal Integral Derivative(PID)control algorithm of integral separation and incremental mode with setting dead area.The principle of work and the key technique on the electromagnetic regulation and control are introduced in detail in this paper.The experiment result gives a proof for all the algorithm mentioned in this paper.

  4. Inspection of advanced computational lithography logic reticles using a 193-nm inspection system

    Science.gov (United States)

    Yu, Ching-Fang; Lin, Mei-Chun; Lai, Mei-Tsu; Hsu, Luke T. H.; Chin, Angus; Lee, S. C.; Yen, Anthony; Wang, Jim; Chen, Ellison; Wu, David; Broadbent, William H.; Huang, William; Zhu, Zinggang

    2010-09-01

    We report inspection results of early 22-nm logic reticles designed with both conventional and computational lithography methods. Inspection is performed using a state-of-the-art 193-nm reticle inspection system in the reticleplane inspection mode (RPI) where both rule-based sensitivity control (RSC) and a newer modelbased sensitivity control (MSC) method are tested. The evaluation includes defect detection performance using several special test reticles designed with both conventional and computational lithography methods; the reticles contain a variety of programmed critical defects which are measured based on wafer print impact. Also included are inspection results from several full-field product reticles designed with both conventional and computational lithography methods to determine if low nuisance-defect counts can be achieved. These early reticles are largely single-die and all inspections are performed in the die-to-database inspection mode only.

  5. Feature-based multiresolution techniques for product design

    Institute of Scientific and Technical Information of China (English)

    LEE Sang Hun; LEE Kunwoo

    2006-01-01

    3D computer-aided design (CAD) systems based on feature-based solid modelling technique have been widely spread and used for product design. However, when part models associated with features are used in various downstream applications,simplified models in various levels of detail (LODs) are frequently more desirable than the full details of the parts. In particular,the need for feature-based multiresolution representation of a solid model representing an object at multiple LODs in the feature unit is increasing for engineering tasks. One challenge is to generate valid models at various LODs after an arbitrary rearrangement of features using a certain LOD criterion, because composite Boolean operations consisting of union and subtraction are not commutative. The other challenges are to devise proper topological framework for multiresolution representation, to suggest more reasonable LOD criteria, and to extend applications. This paper surveys the recent research on these issues.

  6. Selection of procedures for inservice inspections; Auswahl der Verfahren fuer wiederkehrende Pruefungen

    Energy Technology Data Exchange (ETDEWEB)

    Brast, G. [Preussische Elektrizitaets-AG (Preussenelektra), Hannover (Germany); Britz, A. [Bayernwerk AG, Muenchen (Germany); Maier, H.J. [Stuttgart Univ. (Germany). Staatliche Materialpruefungsanstalt; Seidenkranz, T. [TUEV Energie- und Systemtechnik GmbH, Mannheim (Germany)

    1998-11-01

    At present, selection of procedures for inservice inspection has to take into account the legal basis, i.e. the existing regulatory codes, and the practical aspects, i.e. experience and information obtained by the general, initial inservice inspection or performance data obtained by the latest, recurrent inspection. However, regulatory codes are being reviewed to a certain extent in order to permit integration of technological progress. Depending on the degree of availability in future, of inspection task-specific, sensitive and qualified NDE techniques for inservice inspections (`risk based ISI`), the framework of defined inspection intervals, sites, and detection limits will be broken up and altered in response to progress made. This opens up new opportunities for an optimization of inservice inspections for proof of component integrity. (orig./CB) [Deutsch] Zur Zeit muss sich die Auswahl der Pruefverfahren an den gueltigen Regelwerken und, da es sich um wiederkehrende Pruefungen handelt, an der Basispruefung bzw. der letzten wiederkehrenden Pruefung orientieren. Jedoch vollzieht sich zur Zeit eine Oeffnung der Regelwerke, mit der man auch der Weiterentwicklung der Prueftechniken Rechnung traegt. In dem Masse, wie zukuenftig auf die Pruefaufgabe/Pruefaussage optimal abgestimmte und qualifizierte Prueftechniken mit einer hohen Nachweisempfindlichkeit am Bauteil fuer zielgerichtete wiederkehrende Pruefungen (als `risk based ISI`) zur Verfuegung stehen, wird der Rahmen mit festgelegten Pruefintervallen, Prueforten und festen Registriergrenzen gesprengt und variabel gestaltet werden koennen. Damit ergeben sich neue Moeglichkeiten fuer eine Optimierung der WKP zum Nachweis der Integritaet des Bauteils. (orig./MM)

  7. ANNUAL RADIOACTIVE WASTE TANK INSPECTION PROGRAM - 2011

    Energy Technology Data Exchange (ETDEWEB)

    West, B.; Waltz, R.

    2012-06-21

    Aqueous radioactive wastes from Savannah River Site (SRS) separations and vitrification processes are contained in large underground carbon steel tanks. Inspections made during 2011 to evaluate these vessels and other waste handling facilities along with evaluations based on data from previous inspections are the subject of this report. The 2011 inspection program revealed that the structural integrity and waste confinement capability of the Savannah River Site waste tanks were maintained. All inspections scheduled per SRR-LWE-2011-00026, HLW Tank Farm Inspection Plan for 2011, were completed. Ultrasonic measurements (UT) performed in 2011 met the requirements of C-ESR-G-00006, In-Service Inspection Program for High Level Waste Tanks, Rev. 3, and WSRC-TR-2002-00061, Rev.6. UT inspections were performed on Tanks 25, 26 and 34 and the findings are documented in SRNL-STI-2011-00495, Tank Inspection NDE Results for Fiscal Year 2011, Waste Tanks 25, 26, 34 and 41. A total of 5813 photographs were made and 835 visual and video inspections were performed during 2011. A potential leaksite was discovered at Tank 4 during routine annual inspections performed in 2011. The new crack, which is above the allowable fill level, resulted in no release to the environment or tank annulus. The location of the crack is documented in C-ESR-G-00003, SRS High Level Waste Tank Leaksite Information, Rev.6.

  8. Transformer-based design techniques for oscillators and frequency dividers

    CERN Document Server

    Luong, Howard Cam

    2016-01-01

    This book provides in-depth coverage of transformer-based design techniques that enable CMOS oscillators and frequency dividers to achieve state-of-the-art performance.  Design, optimization, and measured performance of oscillators and frequency dividers for different applications are discussed in detail, focusing on not only ultra-low supply voltage but also ultra-wide frequency tuning range and locking range.  This book will be an invaluable reference for anyone working or interested in CMOS radio-frequency or mm-Wave integrated circuits and systems.

  9. Modal Analysis Based on the Random Decrement Technique

    DEFF Research Database (Denmark)

    Asmussen, J. C.; Brincker, Rune

    1998-01-01

    This article describes the work carried out within the project: Modal Analysis Based on the Random Decrement Technique - Application to Civil Engineering Structures. The project is part of the research programme: Dynamics of Structures sponsored by the Danish Technical Research Counsil. The planned...... contents and the requirement for the project prior to its start are described together with thee results obtained during the 3 year period of the project. The project was mainly carried out as a Ph.D project by the first author from September 1994 to August 1997 in cooperation with associate professor Rune...

  10. A study on in-pipe inspection mobile robots, 3; Basic strategy of inspection path planning for inspection mobile robots

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Toshio (Nagoya Univ. (Japan). Faculty of Engineering); Hosokai, Hidemi; Uemura, Masahiro

    1990-01-01

    This paper deals with inspection path planning for in-pipe inspection mobile robots which have the capability of moving through complicated pipeline networks. It is imperative that the robot systems have an inspection path planning system for such networks for their reasonable and rational operation, controlled by themselves or by the operators. The planning mainly requires two projects: the selection of the place to put the robot in or out, and the generation of the paths in the networks. This system provides the for complicated problems with plural inspection points using a basic strategy of systematically producing patterns and dividing partial problems of simple searches based on rules. (author).

  11. Aspects of Inspection Planning

    DEFF Research Database (Denmark)

    Faber, M. H.; Sørensen, John Dalsgaard

    2000-01-01

    Inspection planning for systems is considered with special emphasis to the effect of the quality of inspections on the system reliability and the probability of repair. Inspection quality is described and discussed in terms of inspection reliability and inspection coverage where the latter is set...... in relation to the correlation between the failure modes of the considered system. The inspection planning problem is described in general terms taking basis in the Bayesian decision theory. Practical applicable approaches are derived from the more general but also more involving formulations. The theoretical...... framework for updating of the reliability of components and systems on the basis of inspection results is outlined. Systems representative for inspection planning of different engineering systems subjected to typical deterioration processes are presented. Numerical simulation studies are performed...

  12. Recipe creation for automated defect classification with a 450mm surface scanning inspection system based on the bidirectional reflectance distribution function of native defects

    Science.gov (United States)

    Yathapu, Nithin; McGarvey, Steve; Brown, Justin; Zhivotovsky, Alexander

    2016-03-01

    This study explores the feasibility of Automated Defect Classification (ADC) with a Surface Scanning Inspection System (SSIS). The defect classification was based upon scattering sensitivity sizing curves created via modeling of the Bidirectional Reflectance Distribution Function (BRDF). The BRDF allowed for the creation of SSIS sensitivity/sizing curves based upon the optical properties of both the filmed wafer samples and the optical architecture of the SSIS. The elimination of Polystyrene Latex Sphere (PSL) and Silica deposition on both filmed and bare Silicon wafers prior to SSIS recipe creation and ADC creates a challenge for light scattering surface intensity based defect binning. This study explored the theoretical maximal SSIS sensitivity based on native defect recipe creation in conjunction with the maximal sensitivity derived from BRDF modeling recipe creation. Single film and film stack wafers were inspected with recipes based upon BRDF modeling. Following SSIS recipe creation, initially targeting maximal sensitivity, selected recipes were optimized to classify defects commonly found on non-patterned wafers. The results were utilized to determine the ADC binning accuracy of the native defects and evaluate the SSIS recipe creation methodology. A statistically valid sample of defects from the final inspection results of each SSIS recipe and filmed substrate were reviewed post SSIS ADC processing on a Defect Review Scanning Electron Microscope (SEM). Native defect images were collected from each statistically valid defect bin category/size for SEM Review. The data collected from the Defect Review SEM was utilized to determine the statistical purity and accuracy of each SSIS defect classification bin. This paper explores both, commercial and technical, considerations of the elimination of PSL and Silica deposition as a precursor to SSIS recipe creation targeted towards ADC. Successful integration of SSIS ADC in conjunction with recipes created via BRDF

  13. Implementation of a tolerance model in a computer aided design and inspection system

    Directory of Open Access Journals (Sweden)

    R. Hunter

    2006-04-01

    Full Text Available Purpose: Purpose of this paper is present a detailed framework to integrate the Computer Aided Design (CAD and Inspection (CAI systems through the integration of the Geometric Dimensioning and Tolerancing (GD&T with the inspection process in coordinate measuring machines (CMMs.Design/methodology/approach: The approach used to develop a prototype of a Knowledge Based System (KBS applied to inspection process establishes a new methodology for integrate the geometric dimensioning and tolerancing (GD&T. The integration is achieved through the definition of the knowledge units for functional properties of GD&T, inspection resources and inspection operations in a common knowledge model. The manufacturing and processing applications are the main topics approach of this paper.Findings: The findings are focused in modeling the features and interactions between knowledge units associated to topology, geometry and tolerances with the inspection process activities. The implementation of the product knowledge model is presented in a computer platform that extracts and represents the GD&T information in a CAI system.Research limitations/implications: The implications are focused on the automation of the inspection process in a KBS application. The future research is focused on the use of artificial intelligent technique, such as genetic algorithms and neural networks, to optimize the time to execute the inspection process.Practical implications: The main outcomes and implication of the KBS prototype application are focused on the reduction of the time spend to develop the inspection process. This KBS application provides the needed information to elaborate this process without the human interface.Originality/value: The original value of this paper is the integration of the design and inspection specification in a unique prototype application. The knowledge model has been defined in a common modeling language (UML and can be implemented in different

  14. Structural level characterization of base oils using advanced analytical techniques

    KAUST Repository

    Hourani, Nadim

    2015-05-21

    Base oils, blended for finished lubricant formulations, are classified by the American Petroleum Institute into five groups, viz., groups I-V. Groups I-III consist of petroleum based hydrocarbons whereas groups IV and V are made of synthetic polymers. In the present study, five base oil samples belonging to groups I and III were extensively characterized using high performance liquid chromatography (HPLC), comprehensive two-dimensional gas chromatography (GC×GC), and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) equipped with atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI) sources. First, the capabilities and limitations of each analytical technique were evaluated, and then the availed information was combined to reveal compositional details on the base oil samples studied. HPLC showed the overwhelming presence of saturated over aromatic compounds in all five base oils. A similar trend was further corroborated using GC×GC, which yielded semiquantitative information on the compound classes present in the samples and provided further details on the carbon number distributions within these classes. In addition to chromatography methods, FT-ICR MS supplemented the compositional information on the base oil samples by resolving the aromatics compounds into alkyl- and naphtheno-subtituted families. APCI proved more effective for the ionization of the highly saturated base oil components compared to APPI. Furthermore, for the detailed information on hydrocarbon molecules FT-ICR MS revealed the presence of saturated and aromatic sulfur species in all base oil samples. The results presented herein offer a unique perspective into the detailed molecular structure of base oils typically used to formulate lubricants. © 2015 American Chemical Society.

  15. A Comparative Analysis of Exemplar Based and Wavelet Based Inpainting Technique

    Directory of Open Access Journals (Sweden)

    Vaibhav V Nalawade

    2012-06-01

    Full Text Available Image inpainting is the process of filling in of missing region so as to preserve its overall continuity. Image inpainting is manipulation and modification of an image in a form that is not easily detected. Digital image inpainting is relatively new area of research, but numerous and different approaches to tackle the inpainting problem have been proposed since the concept was first introduced. This paper compares two separate techniques viz, Exemplar based inpainting technique and Wavelet based inpainting technique, each portraying a different set of characteristics. The algorithms analyzed under exemplar technique are large object removal by exemplar based inpainting technique (Criminisi’s and modified exemplar (Cheng. The algorithm analyzed under wavelet is Chen’s visual image inpainting method. A number of examples on real and synthetic images are demonstrated to compare the results of different algorithms using both qualitative and quantitative parameters.

  16. Emerging nondestructive inspection methods for aging aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Beattie, A; Dahlke, L; Gieske, J [and others

    1994-01-01

    This report identifies and describes emerging nondestructive inspection (NDI) methods that can potentially be used to inspect commercial transport and commuter aircraft for structural damage. The nine categories of emerging NDI techniques are: acoustic emission, x-ray computed tomography, backscatter radiation, reverse geometry x-ray, advanced electromagnetics, including magnetooptic imaging and advanced eddy current techniques, coherent optics, advanced ultrasonics, advanced visual, and infrared thermography. The physical principles, generalized performance characteristics, and typical applications associated with each method are described. In addition, aircraft inspection applications are discussed along with the associated technical considerations. Finally, the status of each technique is presented, with a discussion on when it may be available for use in actual aircraft maintenance programs. It should be noted that this is a companion document to DOT/FAA/CT-91/5, Current Nondestructive Inspection Methods for Aging Aircraft.

  17. Nuclear data needs for non-intrusive inspection.

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D. L.; Michlich, B. J.

    2000-11-29

    Various nuclear-based techniques are being explored for use in non-intrusive inspection. Their development is motivated by the need to prevent the proliferation of nuclear weapons, to thwart trafficking in illicit narcotics, to stop the transport of explosives by terrorist organizations, to characterize nuclear waste, and to deal with various other societal concerns. Non-intrusive methods are sought in order to optimize inspection speed, to minimize damage to packages and containers, to satisfy environmental, health and safety requirements, to adhere to legal requirements, and to avoid inconveniencing the innocent. These inspection techniques can be grouped into two major categories: active and passive. They almost always require the use of highly penetrating radiation and therefore are generally limited to neutrons and gamma rays. Although x-rays are widely employed for these purposes, their use does not constitute nuclear technology and therefore is not discussed here. This paper examines briefly the basic concepts associated with nuclear inspection and investigates the related nuclear data needs. These needs are illustrated by considering four of the methods currently being developed and tested.

  18. On combining Laplacian and optimization-based mesh smoothing techniques

    Energy Technology Data Exchange (ETDEWEB)

    Freitag, L.A.

    1997-07-01

    Local mesh smoothing algorithms have been shown to be effective in repairing distorted elements in automatically generated meshes. The simplest such algorithm is Laplacian smoothing, which moves grid points to the geometric center of incident vertices. Unfortunately, this method operates heuristically and can create invalid meshes or elements of worse quality than those contained in the original mesh. In contrast, optimization-based methods are designed to maximize some measure of mesh quality and are very effective at eliminating extremal angles in the mesh. These improvements come at a higher computational cost, however. In this article the author proposes three smoothing techniques that combine a smart variant of Laplacian smoothing with an optimization-based approach. Several numerical experiments are performed that compare the mesh quality and computational cost for each of the methods in two and three dimensions. The author finds that the combined approaches are very cost effective and yield high-quality meshes.

  19. ONLINE GRINDING WHEEL WEAR COMPENSATION BY IMAGE BASED MEASURING TECHNIQUES

    Institute of Scientific and Technical Information of China (English)

    WAN Daping; HU Dejin; WU Qi; ZHANG Yonghong

    2006-01-01

    Automatic compensation of grinding wheel wear in dry grinding is accomplished by an image based online measurement method. A kind of PC-based charge-coupled device image recognition system is schemed out, which detects the topography changes of the grinding wheel surface. Profile data, which corresponds to the wear and the topography, is measured by using a digital image processing method. The grinding wheel wear is evaluated by analyzing the position deviation of the grinding wheel edge. The online wear compensation is achieved according to the measure results. The precise detection and automatic compensation system is integrated into an open structure CNC curve grinding machine. A practical application is carried out to fulfil the precision curve grinding. The experimental results confirm the benefits of the proposed techniques, and the online detection accuracy is less than 5 μm. The grinding machine provides higher precision according to the in-process grinding wheel error compensation.

  20. Hash Based Least Significant Bit Technique For Video Steganography

    Directory of Open Access Journals (Sweden)

    Prof. Dr. P. R. Deshmukh ,

    2014-01-01

    Full Text Available The Hash Based Least Significant Bit Technique For Video Steganography deals with hiding secret message or information within a video.Steganography is nothing but the covered writing it includes process that conceals information within other data and also conceals the fact that a secret message is being sent.Steganography is the art of secret communication or the science of invisible communication. In this paper a Hash based least significant bit technique for video steganography has been proposed whose main goal is to embed a secret information in a particular video file and then extract it using a stego key or password. In this Least Significant Bit insertion method is used for steganography so as to embed data in cover video with change in the lower bit.This LSB insertion is not visible.Data hidding is the process of embedding information in a video without changing its perceptual quality. The proposed method involve with two terms that are Peak Signal to Noise Ratio (PSNR and the Mean Square Error (MSE .This two terms measured between the original video files and steganographic video files from all video frames where a distortion is measured using PSNR. A hash function is used to select the particular position for insertion of bits of secret message in LSB bits.

  1. Magnetic Particle Technique: Lab Case of CAMAN

    Directory of Open Access Journals (Sweden)

    Sonia Ruth Rincón Urbina

    2015-10-01

    Full Text Available This article presents the general procedure for the use of the technique of magnetic particles; generally describes the main characteristics of the test and inspection procedure from CAMAN Lab developed at the Graduate School of the Colombian Air Force. The method used in the research and development of the project was documentary, in order to establish the rules and regulations required for certification of the magnetic particles technique in nondestructive testing laboratory by the Aeronautical Authority. Finally, based on the data analysis, an Inspection Procedure Manual was developed in order to certify the magnetic particles technique.

  2. Take a byte out of MEEF: VAMPIRE: Vehicle for Advanced Mask Pattern Inspection Readiness Evaluations

    Science.gov (United States)

    Badger, Karen D.; Rankin, Jed; Turley, Christina; Seki, Kazunori; Dechene, Dan J.; Abdelghany, Hesham

    2016-09-01

    -like conditions to determine which defects are wafer printable. This inspection technique is commonly referred to as being `lithography plane' or `litho plane,' since it's assessing the mask quality based on how the mask appears to the imaging optics during use, as proposed to traditional `reticle plane' inspection which is comparing the mask only with its target design. Regardless of how the defects are detected, the real question is when should they be detected? For larger technology nodes, defects are considered `statistical risks'…i.e., first they have to occur, and then they have to fall in high-MEEF areas in order to be of concern, and be below the detection limits of traditional reticle-plane inspection. In short, the `perfect storm' has to happen in order to miss printable defects using well-optimized traditional inspection approaches. The introduction of lithographic inspection techniques has revealed this statistical game is a much higher risk than originally estimated, in that very subtle waferprintable CD errors typically fall into the desense band for traditional reticle plane inspection. Because printability is largely influenced by MEEF, designs with high-MEEF values are at greater risk of traditional inspection missing printable CD errors. The question is… how high is high… and at what MEEF is optical inspection at the reticle plane sufficient? This paper will provide evaluation results for both reticle-plane and litho-plane inspections as they pertain to varying degrees of MEEF. A newly designed high-MEEF programmed defect test mask, named VAMPIRE, will be introduced. This test mask is based on 7 nm node technology and contains intentionally varying degrees of MEEF as well as a variety of programmed defects in high-MEEF environments…all of which have been verified for defect lithographic significance on a Zeiss AIMS system.

  3. An interactive tutorial-based training technique for vertebral morphometry.

    Science.gov (United States)

    Gardner, J C; von Ingersleben, G; Heyano, S L; Chesnut, C H

    2001-01-01

    The purpose of this work was to develop a computer-based procedure for training technologists in vertebral morphometry. The utility of the resulting interactive, tutorial based training method was evaluated in this study. The training program was composed of four steps: (1) review of an online tutorial, (2) review of analyzed spine images, (3) practice in fiducial point placement and (4) testing. During testing, vertebral heights were measured from digital, lateral spine images containing osteoporotic fractures. Inter-observer measurement precision was compared between research technicians, and between technologists and radiologist. The technologists participating in this study had no prior experience in vertebral morphometry. Following completion of the online training program, good inter-observer measurement precision was seen between technologists, showing mean coefficients of variation of 2.33% for anterior, 2.87% for central and 2.65% for posterior vertebral heights. Comparisons between the technicians and radiologist ranged from 2.19% to 3.18%. Slightly better precision values were seen with height measurements compared with height ratios, and with unfractured compared with fractured vertebral bodies. The findings of this study indicate that self-directed, tutorial-based training for spine image analyses is effective, resulting in good inter-observer measurement precision. The interactive tutorial-based approach provides standardized training methods and assures consistency of instructional technique over time.

  4. Enhancing the effectiveness of IST through risk-based techniques

    Energy Technology Data Exchange (ETDEWEB)

    Floyd, S.D.

    1996-12-01

    Current IST requirements were developed mainly through deterministic-based methods. While this approach has resulted in an adequate level of safety and reliability for pumps and valves, insights from probabilistic safety assessments suggest a better safety focus can be achieved at lower costs. That is, some high safety impact pumps and valves are currently not tested under the IST program and should be added, while low safety impact valves could be tested at significantly greater intervals than allowed by the current IST program. The nuclear utility industry, through the Nuclear Energy Institute (NEI), has developed a draft guideline for applying risk-based techniques to focus testing on those pumps and valves with a high safety impact while reducing test frequencies on low safety impact pumps and valves. The guideline is being validated through an industry pilot application program that is being reviewed by the U.S. Nuclear Regulatory Commission. NEI and the ASME maintain a dialogue on the two groups` activities related to risk-based IST. The presenter will provide an overview of the NEI guideline, discuss the methodological approach for applying risk-based technology to IST and provide the status of the industry pilot plant effort.

  5. PDMS microchannel fabrication technique based on microwire-molding

    Institute of Scientific and Technical Information of China (English)

    JIA YueFei; JIANG JiaHuan; MA XiaoDong; LI Yuan; HUANG HeMing; CAI KunBao; CAI ShaoXi; WU YunPeng

    2008-01-01

    Micro-flow channel is basic functional component of microfluidic chip, and every step-forward of its construction technique has been receiving concern all over the world. This article presents a notcomplicated but flexible method for fabrication of micro-flow channels. This method mainly utilizes the conventional molding capability of polydimethylsiloxane (PDMS) and widespread commercial microwires as templates. We have fabricated out some conventional types of microchannels with different topological shapes, as examples for the demonstration of this flexible fabrication route which was not dependent on the stringent demands of photolithographical or microelectromechanical system (MEMS)techniques. The smooth surface, high-intensity, and high flexibility of the wires made it possible to create many types of topological structures of the two-dimensional or three-dimensional microchannel or channel array. The geometric shape of the cross-section of thus forming microchannel in PDMS was the negative of that of embedded-in microwire, in high-fidelity if suitable measures were taken. Moreover, such a microchannel fabrication process can easily integrate the conductivity and low resistivity of the metal wire to create micro-flow devices that are suitable for the electromagnetic control of liquid or the temperature regulation in the microchannel. Furthermore some preliminary optical analysis was provided for the observation of thus forming rounded microchannel. Based on this molding strategy,we even made some prototypes for functional microflow application, such as microsolenoids chip and temperature control gadgets. And an experiment of forming a droplet in the cross channel further confirmed the feasibility and applicability of this flexible microchannel forming technique.

  6. Approximations in Inspection Planning

    DEFF Research Database (Denmark)

    Engelund, S.; Sørensen, John Dalsgaard; Faber, M. H.

    2000-01-01

    Planning of inspections of civil engineering structures may be performed within the framework of Bayesian decision analysis. The effort involved in a full Bayesian decision analysis is relatively large. Therefore, the actual inspection planning is usually performed using a number of approximations....... One of the more important of these approximations is the assumption that all inspections will reveal no defects. Using this approximation the optimal inspection plan may be determined on the basis of conditional probabilities, i.e. the probability of failure given no defects have been found...... by the inspection. In this paper the quality of this approximation is investigated. The inspection planning is formulated both as a full Bayesian decision problem and on the basis of the assumption that the inspection will reveal no defects....

  7. Optimization of an Optical Inspection System Based on the Taguchi Method for Quantitative Analysis of Point-of-Care Testing

    Directory of Open Access Journals (Sweden)

    Chia-Hsien Yeh

    2014-09-01

    Full Text Available This study presents an optical inspection system for detecting a commercial point-of-care testing product and a new detection model covering from qualitative to quantitative analysis. Human chorionic gonadotropin (hCG strips (cut-off value of the hCG commercial product is 25 mIU/mL were the detection target in our study. We used a complementary metal-oxide semiconductor (CMOS sensor to detect the colors of the test line and control line in the specific strips and to reduce the observation errors by the naked eye. To achieve better linearity between the grayscale and the concentration, and to decrease the standard deviation (increase the signal to noise ratio, S/N, the Taguchi method was used to find the optimal parameters for the optical inspection system. The pregnancy test used the principles of the lateral flow immunoassay, and the colors of the test and control line were caused by the gold nanoparticles. Because of the sandwich immunoassay model, the color of the gold nanoparticles in the test line was darkened by increasing the hCG concentration. As the results reveal, the S/N increased from 43.48 dB to 53.38 dB, and the hCG concentration detection increased from 6.25 to 50 mIU/mL with a standard deviation of less than 10%. With the optimal parameters to decrease the detection limit and to increase the linearity determined by the Taguchi method, the optical inspection system can be applied to various commercial rapid tests for the detection of ketamine, troponin I, and fatty acid binding protein (FABP.

  8. Optimization of an optical inspection system based on the Taguchi method for quantitative analysis of point-of-care testing.

    Science.gov (United States)

    Yeh, Chia-Hsien; Zhao, Zi-Qi; Shen, Pi-Lan; Lin, Yu-Cheng

    2014-09-01

    This study presents an optical inspection system for detecting a commercial point-of-care testing product and a new detection model covering from qualitative to quantitative analysis. Human chorionic gonadotropin (hCG) strips (cut-off value of the hCG commercial product is 25 mIU/mL) were the detection target in our study. We used a complementary metal-oxide semiconductor (CMOS) sensor to detect the colors of the test line and control line in the specific strips and to reduce the observation errors by the naked eye. To achieve better linearity between the grayscale and the concentration, and to decrease the standard deviation (increase the signal to noise ratio, S/N), the Taguchi method was used to find the optimal parameters for the optical inspection system. The pregnancy test used the principles of the lateral flow immunoassay, and the colors of the test and control line were caused by the gold nanoparticles. Because of the sandwich immunoassay model, the color of the gold nanoparticles in the test line was darkened by increasing the hCG concentration. As the results reveal, the S/N increased from 43.48 dB to 53.38 dB, and the hCG concentration detection increased from 6.25 to 50 mIU/mL with a standard deviation of less than 10%. With the optimal parameters to decrease the detection limit and to increase the linearity determined by the Taguchi method, the optical inspection system can be applied to various commercial rapid tests for the detection of ketamine, troponin I, and fatty acid binding protein (FABP).

  9. ANNUAL RADIOACTIVE WASTE TANK INSPECTION PROGRAM 2008

    Energy Technology Data Exchange (ETDEWEB)

    West, B.; Waltz, R.

    2009-06-11

    Aqueous radioactive wastes from Savannah River Site (SRS) separations and vitrification processes are contained in large underground carbon steel tanks. Inspections made during 2008 to evaluate these vessels and other waste handling facilities along with evaluations based on data from previous inspections are the subject of this report.

  10. Annual Radioactive Waste Tank Inspection Program - 1997

    Energy Technology Data Exchange (ETDEWEB)

    McNatt, F.G. [Westinghouse Savannah River Company, AIKEN, SC (United States)

    1998-05-01

    Aqueous radioactive wastes from Savannah River Site (SRS) separations processes are contained in large underground carbon steel tanks. Inspections made during 1997 to evaluate these vessels, and evaluations based on data accrued by inspections performed since the tanks were constructed are the subject of this report.

  11. Annual radioactive waste tank inspection program: 1995

    Energy Technology Data Exchange (ETDEWEB)

    McNatt, F.G. Sr.

    1996-04-01

    Aqueous radioactive wastes from Savannah River Site (SRS) separations processes are contained in large underground carbon steel tanks. Inspections made during 1995 to evaluate these vessels and evaluations based on data accrued by inspections performed since the tanks were constructed are the subject of this report

  12. Annual radioactive waste tank inspection program - 1996

    Energy Technology Data Exchange (ETDEWEB)

    McNatt, F.G.

    1997-04-01

    Aqueous radioactive wastes from Savannah River Site (SRS) separations processes are contained in large underground carbon steel tanks. Inspections made during 1996 to evaluate these vessels, and evaluations based on data accrued by inspections performed since the tanks were constructed, are the subject of this report.

  13. The Role that Trace Evidence Techniques Play in Homicide Cases Inspection%痕迹物证技术在命案侦破中的作用

    Institute of Scientific and Technical Information of China (English)

    邵玉龙

    2012-01-01

    Identification techniques for trace evidence play an important role in combating criminal offen- ses. They provide direct and objective evidence for the investigation of cases and trials. The uncovered homi- cide case took place in June 4 of 2009 set a good example for successfully using the examination and identifica- tion of traces evidence techniques and providing evidence for procedure.%痕迹物证的检验鉴定技术在打击刑事犯罪中起着重要作用,为案件侦破和审理的顺利进行提供了直接客观的证据。2009年6月4日云南省芒市侦破的一起命案,是成功运用痕迹物证检验鉴定技术破获案件及提供诉讼证据的典范。

  14. Detecting Molecular Properties by Various Laser-Based Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Hsin, Tse-Ming [Iowa State Univ., Ames, IA (United States)

    2007-01-01

    Four different laser-based techniques were applied to study physical and chemical characteristics of biomolecules and dye molecules. These techniques are liole burning spectroscopy, single molecule spectroscopy, time-resolved coherent anti-Stokes Raman spectroscopy and laser-induced fluorescence microscopy. Results from hole burning and single molecule spectroscopy suggested that two antenna states (C708 & C714) of photosystem I from cyanobacterium Synechocystis PCC 6803 are connected by effective energy transfer and the corresponding energy transfer time is ~6 ps. In addition, results from hole burning spectroscopy indicated that the chlorophyll dimer of the C714 state has a large distribution of the dimer geometry. Direct observation of vibrational peaks and evolution of coumarin 153 in the electronic excited state was demonstrated by using the fs/ps CARS, a variation of time-resolved coherent anti-Stokes Raman spectroscopy. In three different solvents, methanol, acetonitrile, and butanol, a vibration peak related to the stretch of the carbonyl group exhibits different relaxation dynamics. Laser-induced fluorescence microscopy, along with the biomimetic containers-liposomes, allows the measurement of the enzymatic activity of individual alkaline phosphatase from bovine intestinal mucosa without potential interferences from glass surfaces. The result showed a wide distribution of the enzyme reactivity. Protein structural variation is one of the major reasons that are responsible for this highly heterogeneous behavior.

  15. Investigations on landmine detection by neutron-based techniques.

    Science.gov (United States)

    Csikai, J; Dóczi, R; Király, B

    2004-07-01

    Principles and techniques of some neutron-based methods used to identify the antipersonnel landmines (APMs) are discussed. New results have been achieved in the field of neutron reflection, transmission, scattering and reaction techniques. Some conclusions are as follows: The neutron hand-held detector is suitable for the observation of anomaly caused by a DLM2-like sample in different soils with a scanning speed of 1m(2)/1.5 min; the reflection cross section of thermal neutrons rendered the determination of equivalent thickness of different soil components possible; a simple method was developed for the determination of the thermal neutron flux perturbation factor needed for multi-elemental analysis of bulky samples; unfolded spectra of elastically backscattered neutrons using broad-spectrum sources render the identification of APMs possible; the knowledge of leakage spectra of different source neutrons is indispensable for the determination of the differential and integrated reaction rates and through it the dimension of the interrogated volume; the precise determination of the C/O atom fraction requires the investigations on the angular distribution of the 6.13MeV gamma-ray emitted in the (16)O(n,n'gamma) reaction. These results, in addition to the identification of landmines, render the improvement of the non-intrusive neutron methods possible.

  16. Investigations on landmine detection by neutron-based techniques

    Energy Technology Data Exchange (ETDEWEB)

    Csikai, J. E-mail: csikai@delfin.klte.hu; Doczi, R.; Kiraly, B

    2004-07-01

    Principles and techniques of some neutron-based methods used to identify the antipersonnel landmines (APMs) are discussed. New results have been achieved in the field of neutron reflection, transmission, scattering and reaction techniques. Some conclusions are as follows: The neutron hand-held detector is suitable for the observation of anomaly caused by a DLM2-like sample in different soils with a scanning speed of 1 m{sup 2}/1.5 min; the reflection cross section of thermal neutrons rendered the determination of equivalent thickness of different soil components possible; a simple method was developed for the determination of the thermal neutron flux perturbation factor needed for multi-elemental analysis of bulky samples; unfolded spectra of elastically backscattered neutrons using broad-spectrum sources render the identification of APMs possible; the knowledge of leakage spectra of different source neutrons is indispensable for the determination of the differential and integrated reaction rates and through it the dimension of the interrogated volume; the precise determination of the C/O atom fraction requires the investigations on the angular distribution of the 6.13 MeV gamma-ray emitted in the {sup 16}O(n,n'{gamma}) reaction. These results, in addition to the identification of landmines, render the improvement of the non-intrusive neutron methods possible.

  17. A New Particle Swarm Optimization Based Stock Market Prediction Technique

    Directory of Open Access Journals (Sweden)

    Essam El. Seidy

    2016-04-01

    Full Text Available Over the last years, the average person's interest in the stock market has grown dramatically. This demand has doubled with the advancement of technology that has opened in the International stock market, so that nowadays anybody can own stocks, and use many types of software to perform the aspired profit with minimum risk. Consequently, the analysis and prediction of future values and trends of the financial markets have got more attention, and due to large applications in different business transactions, stock market prediction has become a critical topic of research. In this paper, our earlier presented particle swarm optimization with center of mass technique (PSOCoM is applied to the task of training an adaptive linear combiner to form a new stock market prediction model. This prediction model is used with some common indicators to maximize the return and minimize the risk for the stock market. The experimental results show that the proposed technique is superior than the other PSO based models according to the prediction accuracy.

  18. NVC Based Model for Selecting Effective Requirement Elicitation Technique

    Directory of Open Access Journals (Sweden)

    Md. Rizwan Beg

    2012-10-01

    Full Text Available Requirement Engineering process starts from gathering of requirements i.e.; requirements elicitation. Requirementselicitation (RE is the base building block for a software project and has very high impact onsubsequent design and builds phases as well. Accurately capturing system requirements is the major factorin the failure of most of software projects. Due to the criticality and impact of this phase, it is very importantto perform the requirements elicitation in no less than a perfect manner. One of the most difficult jobsfor elicitor is to select appropriate technique for eliciting the requirement. Interviewing and Interactingstakeholder during Elicitation process is a communication intensive activity involves Verbal and Nonverbalcommunication (NVC. Elicitor should give emphasis to Non-verbal communication along with verbalcommunication so that requirements recorded more efficiently and effectively. In this paper we proposea model in which stakeholders are classified by observing non-verbal communication and use it as a basefor elicitation technique selection. We also propose an efficient plan for requirements elicitation which intendsto overcome on the constraints, faced by elicitor.

  19. Filling-Based Techniques Applied to Object Projection Feature Estimation

    CERN Document Server

    Quesada, Luis

    2012-01-01

    3D motion tracking is a critical task in many computer vision applications. Unsupervised markerless 3D motion tracking systems determine the most relevant object in the screen and then track it by continuously estimating its projection features (center and area) from the edge image and a point inside the relevant object projection (namely, inner point), until the tracking fails. Existing object projection feature estimation techniques are based on ray-casting from the inner point. These techniques present three main drawbacks: when the inner point is surrounded by edges, rays may not reach other relevant areas; as a consequence of that issue, the estimated features may greatly vary depending on the position of the inner point relative to the object projection; and finally, increasing the number of rays being casted and the ray-casting iterations (which would make the results more accurate and stable) increases the processing time to the point the tracking cannot be performed on the fly. In this paper, we anal...

  20. Model-checking techniques based on cumulative residuals.

    Science.gov (United States)

    Lin, D Y; Wei, L J; Ying, Z

    2002-03-01

    Residuals have long been used for graphical and numerical examinations of the adequacy of regression models. Conventional residual analysis based on the plots of raw residuals or their smoothed curves is highly subjective, whereas most numerical goodness-of-fit tests provide little information about the nature of model misspecification. In this paper, we develop objective and informative model-checking techniques by taking the cumulative sums of residuals over certain coordinates (e.g., covariates or fitted values) or by considering some related aggregates of residuals, such as moving sums and moving averages. For a variety of statistical models and data structures, including generalized linear models with independent or dependent observations, the distributions of these stochastic processes tinder the assumed model can be approximated by the distributions of certain zero-mean Gaussian processes whose realizations can be easily generated by computer simulation. Each observed process can then be compared, both graphically and numerically, with a number of realizations from the Gaussian process. Such comparisons enable one to assess objectively whether a trend seen in a residual plot reflects model misspecification or natural variation. The proposed techniques are particularly useful in checking the functional form of a covariate and the link function. Illustrations with several medical studies are provided.

  1. Astronomical Image Compression Techniques Based on ACC and KLT Coder

    Directory of Open Access Journals (Sweden)

    J. Schindler

    2011-01-01

    Full Text Available This paper deals with a compression of image data in applications in astronomy. Astronomical images have typical specific properties — high grayscale bit depth, size, noise occurrence and special processing algorithms. They belong to the class of scientific images. Their processing and compression is quite different from the classical approach of multimedia image processing. The database of images from BOOTES (Burst Observer and Optical Transient Exploring System has been chosen as a source of the testing signal. BOOTES is a Czech-Spanish robotic telescope for observing AGN (active galactic nuclei and the optical transient of GRB (gamma ray bursts searching. This paper discusses an approach based on an analysis of statistical properties of image data. A comparison of two irrelevancy reduction methods is presented from a scientific (astrometric and photometric point of view. The first method is based on a statistical approach, using the Karhunen-Loeve transform (KLT with uniform quantization in the spectral domain. The second technique is derived from wavelet decomposition with adaptive selection of used prediction coefficients. Finally, the comparison of three redundancy reduction methods is discussed. Multimedia format JPEG2000 and HCOMPRESS, designed especially for astronomical images, are compared with the new Astronomical Context Coder (ACC coder based on adaptive median regression.

  2. Diagnosis of Dengue Infection Using Conventional and Biosensor Based Techniques

    Directory of Open Access Journals (Sweden)

    Om Parkash

    2015-10-01

    Full Text Available Dengue is an arthropod-borne viral disease caused by four antigenically different serotypes of dengue virus. This disease is considered as a major public health concern around the world. Currently, there is no licensed vaccine or antiviral drug available for the prevention and treatment of dengue disease. Moreover, clinical features of dengue are indistinguishable from other infectious diseases such as malaria, chikungunya, rickettsia and leptospira. Therefore, prompt and accurate laboratory diagnostic test is urgently required for disease confirmation and patient triage. The traditional diagnostic techniques for the dengue virus are viral detection in cell culture, serological testing, and RNA amplification using reverse transcriptase PCR. This paper discusses the conventional laboratory methods used for the diagnosis of dengue during the acute and convalescent phase and highlights the advantages and limitations of these routine laboratory tests. Subsequently, the biosensor based assays developed using various transducers for the detection of dengue are also reviewed.

  3. Crop Yield Forecasted Model Based on Time Series Techniques

    Institute of Scientific and Technical Information of China (English)

    Li Hong-ying; Hou Yan-lin; Zhou Yong-juan; Zhao Hui-ming

    2012-01-01

    Traditional studies on potential yield mainly referred to attainable yield: the maximum yield which could be reached by a crop in a given environment. The new concept of crop yield under average climate conditions was defined in this paper, which was affected by advancement of science and technology. Based on the new concept of crop yield, the time series techniques relying on past yield data was employed to set up a forecasting model. The model was tested by using average grain yields of Liaoning Province in China from 1949 to 2005. The testing combined dynamic n-choosing and micro tendency rectification, and an average forecasting error was 1.24%. In the trend line of yield change, and then a yield turning point might occur, in which case the inflexion model was used to solve the problem of yield turn point.

  4. A polarization-based Thomson scattering technique for burning plasmas

    CERN Document Server

    Parke, E; Hartog, D J Den

    2013-01-01

    The traditional Thomson scattering diagnostic is based on measurement of the wavelength spectrum of scattered light, where electron temperature measurements are inferred from thermal broadening of the scattered laser light. At sufficiently high temperatures, especially those predicted for ITER and other burning plasmas, relativistic effects cause a change in the polarization state of the scattered photons. The resulting depolarization of the scattered light is temperature dependent and has been proposed elsewhere as a potential alternative to the traditional spectral decomposition technique. Following similar work, we analytically calculate the degree of polarization for incoherent Thomson scattering. For the first time, we obtain exact results valid for the full range of incident laser polarization states and electron temperatures. While previous work focused only on linear polarization, we show that circularly polarized incident light optimizes the degree of depolarization for a wide range of temperatures r...

  5. A 3-Level Secure Histogram Based Image Steganography Technique

    Directory of Open Access Journals (Sweden)

    G V Chaitanya

    2013-04-01

    Full Text Available Steganography is an art that involves communication of secret data in an appropriate carrier, eg. images, audio, video, etc. with a goal to hide the very existence of embedded data so as not to arouse an eavesdropper’s suspicion. In this paper, a steganographic technique with high level of security and having a data hiding capacity close to 20% of cover image data has been developed. An adaptive and matched bit replacement method is used based on the sensitivity of Human Visual System (HVS at different intensities. The proposed algorithm ensures that the generated stego image has a PSNR greater than 38.5 and is also resistant to visual attack. A three level security is infused into the algorithm which makes data retrieval from the stego image possible only in case of having all the right keys.

  6. Proposed Arabic Text Steganography Method Based on New Coding Technique

    Directory of Open Access Journals (Sweden)

    Assist. prof. Dr. Suhad M. Kadhem

    2016-09-01

    Full Text Available Steganography is one of the important fields of information security that depend on hiding secret information in a cover media (video, image, audio, text such that un authorized person fails to realize its existence. One of the lossless data compression techniques which are used for a given file that contains many redundant data is run length encoding (RLE. Sometimes the RLE output will be expanded rather than compressed, and this is the main problem of RLE. In this paper we will use a new coding method such that its output will be contains sequence of ones with few zeros, so modified RLE that we proposed in this paper will be suitable for compression, finally we employ the modified RLE output for stenography purpose that based on Unicode and non-printed characters to hide the secret information in an Arabic text.

  7. Whitelists Based Multiple Filtering Techniques in SCADA Sensor Networks

    Directory of Open Access Journals (Sweden)

    DongHo Kang

    2014-01-01

    Full Text Available Internet of Things (IoT consists of several tiny devices connected together to form a collaborative computing environment. Recently IoT technologies begin to merge with supervisory control and data acquisition (SCADA sensor networks to more efficiently gather and analyze real-time data from sensors in industrial environments. But SCADA sensor networks are becoming more and more vulnerable to cyber-attacks due to increased connectivity. To safely adopt IoT technologies in the SCADA environments, it is important to improve the security of SCADA sensor networks. In this paper we propose a multiple filtering technique based on whitelists to detect illegitimate packets. Our proposed system detects the traffic of network and application protocol attacks with a set of whitelists collected from normal traffic.

  8. Clustering economies based on multiple criteria decision making techniques

    Directory of Open Access Journals (Sweden)

    Mansour Momeni

    2011-10-01

    Full Text Available One of the primary concerns on many countries is to determine different important factors affecting economic growth. In this paper, we study some factors such as unemployment rate, inflation ratio, population growth, average annual income, etc to cluster different countries. The proposed model of this paper uses analytical hierarchy process (AHP to prioritize the criteria and then uses a K-mean technique to cluster 59 countries based on the ranked criteria into four groups. The first group includes countries with high standards such as Germany and Japan. In the second cluster, there are some developing countries with relatively good economic growth such as Saudi Arabia and Iran. The third cluster belongs to countries with faster rates of growth compared with the countries located in the second group such as China, India and Mexico. Finally, the fourth cluster includes countries with relatively very low rates of growth such as Jordan, Mali, Niger, etc.

  9. An RSS based location estimation technique for cognitive relay networks

    KAUST Repository

    Qaraqe, Khalid A.

    2010-11-01

    In this paper, a received signal strength (RSS) based location estimation method is proposed for a cooperative wireless relay network where the relay is a cognitive radio. We propose a method for the considered cognitive relay network to determine the location of the source using the direct and the relayed signal at the destination. We derive the Cramer-Rao lower bound (CRLB) expressions separately for x and y coordinates of the location estimate. We analyze the effects of cognitive behaviour of the relay on the performance of the proposed method. We also discuss and quantify the reliability of the location estimate using the proposed technique if the source is not stationary. The overall performance of the proposed method is presented through simulations. ©2010 IEEE.

  10. Hierarchical Spread Spectrum Fingerprinting Scheme Based on the CDMA Technique

    Directory of Open Access Journals (Sweden)

    Kuribayashi Minoru

    2011-01-01

    Full Text Available Abstract Digital fingerprinting is a method to insert user's own ID into digital contents in order to identify illegal users who distribute unauthorized copies. One of the serious problems in a fingerprinting system is the collusion attack such that several users combine their copies of the same content to modify/delete the embedded fingerprints. In this paper, we propose a collusion-resistant fingerprinting scheme based on the CDMA technique. Our fingerprint sequences are orthogonal sequences of DCT basic vectors modulated by PN sequence. In order to increase the number of users, a hierarchical structure is produced by assigning a pair of the fingerprint sequences to a user. Under the assumption that the frequency components of detected sequences modulated by PN sequence follow Gaussian distribution, the design of thresholds and the weighting of parameters are studied to improve the performance. The robustness against collusion attack and the computational costs required for the detection are estimated in our simulation.

  11. Dynamic analysis of granite rockburst based on the PIV technique

    Institute of Scientific and Technical Information of China (English)

    Wang Hongjian; Liu Da’an; Gong Weili; Li Liyun

    2015-01-01

    This paper describes the deep rockburst simulation system to reproduce the granite instantaneous rock-burst process. Based on the PIV (Particle Image Velocimetry) technique, quantitative analysis of a rock-burst, the images of tracer particle, displacement and strain fields can be obtained, and the debris trajectory described. According to the observation of on-site tests, the dynamic rockburst is actually a gas–solid high speed flow process, which is caused by the interaction of rock fragments and surrounding air. With the help of analysis on high speed video and PIV images, the granite rockburst failure process is composed of six stages of platey fragment spalling and debris ejection. Meanwhile, the elastic energy for these six stages has been calculated to study the energy variation. The results indicate that the rockburst process can be summarized as:an initiating stage, intensive developing stage and gradual decay stage. This research will be helpful for our further understanding of the rockburst mechanism.

  12. Demand Management Based on Model Predictive Control Techniques

    Directory of Open Access Journals (Sweden)

    Yasser A. Davizón

    2014-01-01

    Full Text Available Demand management (DM is the process that helps companies to sell the right product to the right customer, at the right time, and for the right price. Therefore the challenge for any company is to determine how much to sell, at what price, and to which market segment while maximizing its profits. DM also helps managers efficiently allocate undifferentiated units of capacity to the available demand with the goal of maximizing revenue. This paper introduces control system approach to demand management with dynamic pricing (DP using the model predictive control (MPC technique. In addition, we present a proper dynamical system analogy based on active suspension and a stability analysis is provided via the Lyapunov direct method.

  13. SAR IMAGE ENHANCEMENT BASED ON BEAM SHARPENING TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    LIYong; ZI-IANGKun-hui; ZHUDai-yin; ZHUZhao-da

    2004-01-01

    A major problem encountered in enhancing SAR image is the total loss of phase information and the unknown parameters of imaging system. The beam sharpening technique, combined with synthetic aperture radiation pattern estimation provides an approach to process this kind of data to achieve higher apparent resolution. Based on the criterion of minimizing the expected quadratic estimation error, an optimum FIR filter with a symmetrical structure is designed whose coefficients depend on the azimuth response of local isolated prominent points because this response can be approximately regarded as the synthetic aperture radiation pattern of the imaging system. The point target simulation shows that the angular resolution is improved by a ratio of almost two to one. The processing results of a live SAR image demonstrate the validity of the method.

  14. A Novel Technique Based on Node Registration in MANETs

    Directory of Open Access Journals (Sweden)

    Rashid Jalal Qureshi

    2012-09-01

    Full Text Available In ad hoc network communication links between the nodes are wireless and each node acts as a router for the other node and packet is forward from one node to other. This type of networks helps in solving challenges and problems that may arise in every day communication. Mobile Ad Hoc Networks is a new field of research and it is particularly useful in situations where network infrastructure is costly. Protecting MANETs from security threats is a challenging task because of the MANETs dynamic topology. Every node in a MANETs is independent and is free to move in any direction, therefore change its connections to other nodes frequently. Due to its decentralized nature different types of attacks can be occur. The aim of this research paper is to investigate different MANETs security attacks and proposed nodes registration based technique by using cryptography functions.

  15. Robotic inspection technology-process an toolbox

    Energy Technology Data Exchange (ETDEWEB)

    Hermes, Markus [ROSEN Group (United States). R and D Dept.

    2005-07-01

    Pipeline deterioration grows progressively with ultimate aging of pipeline systems (on-plot and cross country). This includes both, very localized corrosion as well as increasing failure probability due to fatigue cracking. Limiting regular inspecting activities to the 'scrapable' part of the pipelines only, will ultimately result into a pipeline system with questionable integrity. The confidence level in the integrity of these systems will drop below acceptance levels. Inspection of presently un-inspectable sections of the pipeline system becomes a must. This paper provides information on ROSEN's progress on the 'robotic inspection technology' project. The robotic inspection concept developed by ROSEN is based on a modular toolbox principle. This is mandatory. A universal 'all purpose' robot would not be reliable and efficient in resolving the postulated inspection task. A preparatory Quality Function Deployment (QFD) analysis is performed prior to the decision about the adequate robotic solution. This enhances the serviceability and efficiency of the provided technology. The word 'robotic' can be understood in its full meaning of Recognition - Strategy - Motion - Control. Cooperation of different individual systems with an established communication, e.g. utilizing Bluetooth technology, support the robustness of the ROSEN robotic inspection approach. Beside the navigation strategy, the inspection strategy is also part of the QFD process. Multiple inspection technologies combined on a single carrier or distributed across interacting container must be selected with a clear vision of the particular goal. (author)

  16. Ionospheric Plasma Drift Analysis Technique Based On Ray Tracing

    Science.gov (United States)

    Ari, Gizem; Toker, Cenk

    2016-07-01

    Ionospheric drift measurements provide important information about the variability in the ionosphere, which can be used to quantify ionospheric disturbances caused by natural phenomena such as solar, geomagnetic, gravitational and seismic activities. One of the prominent ways for drift measurement depends on instrumentation based measurements, e.g. using an ionosonde. The drift estimation of an ionosonde depends on measuring the Doppler shift on the received signal, where the main cause of Doppler shift is the change in the length of the propagation path of the signal between the transmitter and the receiver. Unfortunately, ionosondes are expensive devices and their installation and maintenance require special care. Furthermore, the ionosonde network over the world or even Europe is not dense enough to obtain a global or continental drift map. In order to overcome the difficulties related to an ionosonde, we propose a technique to perform ionospheric drift estimation based on ray tracing. First, a two dimensional TEC map is constructed by using the IONOLAB-MAP tool which spatially interpolates the VTEC estimates obtained from the EUREF CORS network. Next, a three dimensional electron density profile is generated by inputting the TEC estimates to the IRI-2015 model. Eventually, a close-to-real situation electron density profile is obtained in which ray tracing can be performed. These profiles can be constructed periodically with a period of as low as 30 seconds. By processing two consequent snapshots together and calculating the propagation paths, we estimate the drift measurements over any coordinate of concern. We test our technique by comparing the results to the drift measurements taken at the DPS ionosonde at Pruhonice, Czech Republic. This study is supported by TUBITAK 115E915 and Joint TUBITAK 114E092 and AS CR14/001 projects.

  17. Carburizing Inspection of Cracking Furnace Tube Using Magnetic Hysteresis Non-Destructive Evaluation Technique%磁滞无损评估技术在裂解炉管渗碳检测中的应用

    Institute of Scientific and Technical Information of China (English)

    刘德宇; 王宁辉; 张国庆; 李国瑞

    2015-01-01

    Large tube type fuel heating furnaces are important and essential equipments, with a wide range of applications in the petroleum and chemical industry, in which the failure modes of furnace tubes are mostly caused by carburizing. To estimate the effect of magnetic hysteresis non-destructive evaluation technique on carburizing inspection, both new and the three-years-service cracking furnace tubes were performed carburizing test. Different carburized depth of tubes were got and their coercivity was tested. The results showed that there is a good relationship between the coercivity and carburized case depth, which would be a great potential applications in the carburizing inspection of tube.%大型管式燃料加热炉是石油化工企业里广泛应用且必不可少的重要设备,其中炉管的失效大多由渗碳引起。为了评价磁滞无损评估技术在渗碳层厚度检测中应用的有效性,对未服役和服役3年的裂解炉炉管进行渗碳实验,得到不同渗碳层厚度的炉管,并采集磁滞参数矫顽力,结果表明,矫顽力与渗碳层厚度具有很好的对应关系,在炉管渗碳检测中具有很大的应用前景。

  18. Advanced Multipath Mitigation Techniques for Satellite-Based Positioning Applications

    Directory of Open Access Journals (Sweden)

    Mohammad Zahidul H. Bhuiyan

    2010-01-01

    Full Text Available Multipath remains a dominant source of ranging errors in Global Navigation Satellite Systems (GNSS, such as the Global Positioning System (GPS or the future European satellite navigation system Galileo. Multipath is generally considered undesirable in the context of GNSS, since the reception of multipath can make significant distortion to the shape of the correlation function used for time delay estimation. However, some wireless communications techniques exploit multipath in order to provide signal diversity though in GNSS, the major challenge is to effectively mitigate the multipath, since we are interested only in the satellite-receiver transit time offset of the Line-Of-Sight (LOS signal for the receiver's position estimate. Therefore, the multipath problem has been approached from several directions in order to mitigate the impact of multipath on navigation receivers, including the development of novel signal processing techniques. In this paper, we propose a maximum likelihood-based technique, namely, the Reduced Search Space Maximum Likelihood (RSSML delay estimator, which is capable of mitigating the multipath effects reasonably well at the expense of increased complexity. The proposed RSSML attempts to compensate the multipath error contribution by performing a nonlinear curve fit on the input correlation function, which finds a perfect match from a set of ideal reference correlation functions with certain amplitude(s, phase(s, and delay(s of the multipath signal. It also incorporates a threshold-based peak detection method, which eventually reduces the code-delay search space significantly. However, the downfall of RSSML is the memory requirement which it uses to store the reference correlation functions. The multipath performance of other delay-tracking methods previously studied for Binary Phase Shift Keying-(BPSK- and Sine Binary Offset Carrier- (SinBOC- modulated signals is also analyzed in closed loop model with the new Composite

  19. TOFD Technique Applied to Weld Inspection of Special Strartures%TOFD技术在特殊结构焊缝检测中的应用

    Institute of Scientific and Technical Information of China (English)

    洪作友; 唐兴军

    2009-01-01

    The working principle of TOFD technique was described. The testing effects were compared between radiographic testing and ultrasonic testing method for the detection of volute plate and seam weld. The actual weld section showed that the planar defects, which were difficult to detect by conventional ultrasonic testing and radiographic testing method, were easy to TOFD technique, but there was some error for the porosity, inclusions and such as volume-like defects between TOFD testing and actual section. Due to its high defect detection rate,sensitive to planar defects, less limits by direction, fast testing speed, intuitive scanning image and with no radiation and so on, TOFD technique had good prospect on the safety evaluation at petrochemical installations and so on special equipments.%叙述了TOFD技术的工作原理.在蜗壳焊缝试板及焊缝检测中将超声波和射线检测技术进行了对比.焊缝的缺陷解剖试验表明,TOFD技术能检出常规超声和射线检测方法难以检出的平面状缺陷,对气孔、夹杂等体积状缺陷的检测结果与实际解剖结果有出入.鉴于TOFD技术缺陷检出率高,对面状缺陷灵敏、不受方向性限制、检测速度快、扫描图显示直观并且无辐射等优点,因此在石化装置等在役特种设备的安全评定中具有很好的推广价值.

  20. Inspection Principle and Defect Quantitative Estimation of Pulsed Remote Field Eddy Current Technique%基于脉冲激励的远场涡流检测机理及缺陷定量评估技术

    Institute of Scientific and Technical Information of China (English)

    杨宾峰; 张辉; 荆毅飞; 李龙军; 崔文岩

    2012-01-01

    Remote field eddy current (RFEC) technique has been widely used for the inspection of ferromagnetic pipes and it's not restricted by the skin-depth effect. However, the technique under the sinusoidal excitation needs a long probe and a high power dissipation, which restricts the application of RFEC in real inspection. The pulse exciting signal has the advantages of rich frequency components, the disadvantages of the traditional RFEC can be overcome by using pulse excitation instead of sinusoidal excitation. On the basis of analyzing the principle of pulsed RFEC, the distributions of the magnetic field and eddy current a-round the pipeline and exciting coil are simulated and analyzed, the changing rule of transient state detecting signals in different field regions is studied and obtained with finite element simulation method, then, the remote field region is confirmed. The zero-crossing time and negative peak value are extracted as the eigenvectors for defect quantification. Finally, the performances of quantifying the axial defect length and depth by the pulsed RFEC are verified by performing an experiment, the result shows that this technique can be used to realize the quantitative estimation of the defect.%脉冲激励信号包含非常丰富的频谱成分,以脉冲激励代替传统的正弦激励为克服远场涡流技术的不足提供了新的解决途径.在分析了脉冲激励下远场涡流检测机理的基础上,仿真分析了激励线圈和管道周围磁场和涡流的分布,得到了检测线圈处于不同场区时瞬态检测信号的变化规律,确定了远场区的范围.并从检测信号中提取了过零时间作为缺陷定量的特征量.最后,采用实验的方法验证了脉冲激励下的远场涡流技术对管道中轴向裂纹缺陷长度和深度的定量检测能力,实验结果表明该技术可以很好的实现对缺陷的定量评估.

  1. Parameter tuning of PVD process based on artificial intelligence technique

    Science.gov (United States)

    Norlina, M. S.; Diyana, M. S. Nor; Mazidah, P.; Rusop, M.

    2016-07-01

    In this study, an artificial intelligence technique is proposed to be implemented in the parameter tuning of a PVD process. Due to its previous adaptation in similar optimization problems, genetic algorithm (GA) is selected to optimize the parameter tuning of the RF magnetron sputtering process. The most optimized parameter combination obtained from GA's optimization result is expected to produce the desirable zinc oxide (ZnO) thin film from the sputtering process. The parameters involved in this study were RF power, deposition time and substrate temperature. The algorithm was tested to optimize the 25 datasets of parameter combinations. The results from the computational experiment were then compared with the actual result from the laboratory experiment. Based on the comparison, GA had shown that the algorithm was reliable to optimize the parameter combination before the parameter tuning could be done to the RF magnetron sputtering machine. In order to verify the result of GA, the algorithm was also been compared to other well known optimization algorithms, which were, particle swarm optimization (PSO) and gravitational search algorithm (GSA). The results had shown that GA was reliable in solving this RF magnetron sputtering process parameter tuning problem. GA had shown better accuracy in the optimization based on the fitness evaluation.

  2. Damage detection technique by measuring laser-based mechanical impedance

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyeonseok; Sohn, Hoon [Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (Daehak-ro 291, Yuseong-gu, Daejeon 305-701) (Korea, Republic of)

    2014-02-18

    This study proposes a method for measurement of mechanical impedance using noncontact laser ultrasound. The measurement of mechanical impedance has been of great interest in nondestructive testing (NDT) or structural health monitoring (SHM) since mechanical impedance is sensitive even to small-sized structural defects. Conventional impedance measurements, however, have been based on electromechanical impedance (EMI) using contact-type piezoelectric transducers, which show deteriorated performances induced by the effects of a) Curie temperature limitations, b) electromagnetic interference (EMI), c) bonding layers and etc. This study aims to tackle the limitations of conventional EMI measurement by utilizing laser-based mechanical impedance (LMI) measurement. The LMI response, which is equivalent to a steady-state ultrasound response, is generated by shooting the pulse laser beam to the target structure, and is acquired by measuring the out-of-plane velocity using a laser vibrometer. The formation of the LMI response is observed through the thermo-mechanical finite element analysis. The feasibility of applying the LMI technique for damage detection is experimentally verified using a pipe specimen under high temperature environment.

  3. Electron tomography based on a total variation minimization reconstruction technique

    Energy Technology Data Exchange (ETDEWEB)

    Goris, B., E-mail: bart.goris@ua.ac.be [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Van den Broek, W. [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Batenburg, K.J. [Centrum Wiskunde and Informatica, Science Park 123, NL-1098XG Amsterdam (Netherlands); Vision Lab, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk (Belgium); Heidari Mezerji, H.; Bals, S. [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

    2012-02-15

    The 3D reconstruction of a tilt series for electron tomography is mostly carried out using the weighted backprojection (WBP) algorithm or using one of the iterative algorithms such as the simultaneous iterative reconstruction technique (SIRT). However, it is known that these reconstruction algorithms cannot compensate for the missing wedge. Here, we apply a new reconstruction algorithm for electron tomography, which is based on compressive sensing. This is a field in image processing specialized in finding a sparse solution or a solution with a sparse gradient to a set of ill-posed linear equations. Therefore, it can be applied to electron tomography where the reconstructed objects often have a sparse gradient at the nanoscale. Using a combination of different simulated and experimental datasets, it is shown that missing wedge artefacts are reduced in the final reconstruction. Moreover, it seems that the reconstructed datasets have a higher fidelity and are easier to segment in comparison to reconstructions obtained by more conventional iterative algorithms. -- Highlights: Black-Right-Pointing-Pointer A reconstruction algorithm for electron tomography is investigated based on total variation minimization. Black-Right-Pointing-Pointer Missing wedge artefacts are reduced by this algorithm. Black-Right-Pointing-Pointer The reconstruction is easier to segment. Black-Right-Pointing-Pointer More reliable quantitative information can be obtained.

  4. The effects of processing techniques on magnesium-based composite

    Science.gov (United States)

    Rodzi, Siti Nur Hazwani Mohamad; Zuhailawati, Hussain

    2016-12-01

    The aim of this study is to investigate the effect of processing techniques on the densification, hardness and compressive strength of Mg alloy and Mg-based composite for biomaterial application. The control sample (pure Mg) and Mg-based composite (Mg-Zn/HAp) were fabricated through mechanical alloying process using high energy planetary mill, whilst another Mg-Zn/HAp composite was fabricated through double step processing (the matrix Mg-Zn alloy was fabricated by planetary mill, subsequently HAp was dispersed by roll mill). As-milled powder was then consolidated by cold press into 10 mm diameter pellet under 400 MPa compaction pressure before being sintered at 300 °C for 1 hour under the flow of argon. The densification of the sintered pellets were then determined by Archimedes principle. Mechanical properties of the sintered pellets were characterized by microhardness and compression test. The results show that the density of the pellets was significantly increased by addition of HAp, but the most optimum density was observed when the sample was fabricated through double step processing (1.8046 g/cm3). Slight increment in hardness and ultimate compressive strength were observed for Mg-Zn/HAp composite that was fabricated through double step processing (58.09 HV, 132.19 MPa), as compared to Mg-Zn/HAp produced through single step processing (47.18 HV, 122.49 MPa).

  5. Introducing Risk Management Techniques Within Project Based Software Engineering Courses

    Science.gov (United States)

    Port, Daniel; Boehm, Barry

    2002-03-01

    In 1996, USC switched its core two-semester software engineering course from a hypothetical-project, homework-and-exam course based on the Bloom taxonomy of educational objectives (knowledge, comprehension, application, analysis, synthesis, and evaluation). The revised course is a real-client team-project course based on the CRESST model of learning objectives (content understanding, problem solving, collaboration, communication, and self-regulation). We used the CRESST cognitive demands analysis to determine the necessary student skills required for software risk management and the other major project activities, and have been refining the approach over the last 5 years of experience, including revised versions for one-semester undergraduate and graduate project course at Columbia. This paper summarizes our experiences in evolving the risk management aspects of the project course. These have helped us mature more general techniques such as risk-driven specifications, domain-specific simplifier and complicator lists, and the schedule as an independent variable (SAIV) process model. The largely positive results in terms of review of pass / fail rates, client evaluations, product adoption rates, and hiring manager feedback are summarized as well.

  6. Validation techniques of agent based modelling for geospatial simulations

    Directory of Open Access Journals (Sweden)

    M. Darvishi

    2014-10-01

    Full Text Available One of the most interesting aspects of modelling and simulation study is to describe the real world phenomena that have specific properties; especially those that are in large scales and have dynamic and complex behaviours. Studying these phenomena in the laboratory is costly and in most cases it is impossible. Therefore, Miniaturization of world phenomena in the framework of a model in order to simulate the real phenomena is a reasonable and scientific approach to understand the world. Agent-based modelling and simulation (ABMS is a new modelling method comprising of multiple interacting agent. They have been used in the different areas; for instance, geographic information system (GIS, biology, economics, social science and computer science. The emergence of ABM toolkits in GIS software libraries (e.g. ESRI’s ArcGIS, OpenMap, GeoTools, etc for geospatial modelling is an indication of the growing interest of users to use of special capabilities of ABMS. Since ABMS is inherently similar to human cognition, therefore it could be built easily and applicable to wide range applications than a traditional simulation. But a key challenge about ABMS is difficulty in their validation and verification. Because of frequent emergence patterns, strong dynamics in the system and the complex nature of ABMS, it is hard to validate and verify ABMS by conventional validation methods. Therefore, attempt to find appropriate validation techniques for ABM seems to be necessary. In this paper, after reviewing on Principles and Concepts of ABM for and its applications, the validation techniques and challenges of ABM validation are discussed.

  7. Validation techniques of agent based modelling for geospatial simulations

    Science.gov (United States)

    Darvishi, M.; Ahmadi, G.

    2014-10-01

    One of the most interesting aspects of modelling and simulation study is to describe the real world phenomena that have specific properties; especially those that are in large scales and have dynamic and complex behaviours. Studying these phenomena in the laboratory is costly and in most cases it is impossible. Therefore, Miniaturization of world phenomena in the framework of a model in order to simulate the real phenomena is a reasonable and scientific approach to understand the world. Agent-based modelling and simulation (ABMS) is a new modelling method comprising of multiple interacting agent. They have been used in the different areas; for instance, geographic information system (GIS), biology, economics, social science and computer science. The emergence of ABM toolkits in GIS software libraries (e.g. ESRI's ArcGIS, OpenMap, GeoTools, etc) for geospatial modelling is an indication of the growing interest of users to use of special capabilities of ABMS. Since ABMS is inherently similar to human cognition, therefore it could be built easily and applicable to wide range applications than a traditional simulation. But a key challenge about ABMS is difficulty in their validation and verification. Because of frequent emergence patterns, strong dynamics in the system and the complex nature of ABMS, it is hard to validate and verify ABMS by conventional validation methods. Therefore, attempt to find appropriate validation techniques for ABM seems to be necessary. In this paper, after reviewing on Principles and Concepts of ABM for and its applications, the validation techniques and challenges of ABM validation are discussed.

  8. Comparative Calibration of Corrosion Measurements Using K-Nearest Neighbour Based Techniques

    Directory of Open Access Journals (Sweden)

    Hamed Yaman

    2016-01-01

    Full Text Available Every measuring equipment or inspection tool is known to have its own accuracy, which may affect the reliability of its measurements. This includes oil and gas pipeline corrosion defects measurements. The inspection tolerance occurred in the measurements should be treated carefully for each equipment to prevent misinterpretation of the data which could lead to incorrect assessment. This paper presents a comparison between two K-Nearest Neighbour (KNN interpolation techniques used to calibrate corrosion measurements collected by Magnetic Flux Leakage Intelligent Pig (MFL-IP with the readings of Ultrasonic Testing (UT scan device. The comparison has relied on the position of the interpolators, the weight sequence, and the error in the final enhanced metrics compared to the original measurements. Both techniques have the potential to calibrate and enhance IP measurements, with relative advantage for one technique in reducing over fitting problem. This enhancement will be used to improve the integrity assessment report that depends on the disturbed corrosion metrics of oil and gas pipelines, to decide whether the pipeline is fit for service or needs certain maintenance.

  9. Optical inspection of EPL stencil masks

    Science.gov (United States)

    Lee, Po-Tung; Engelstad, Roxann L.; Lovell, Edward G.; Kawata, Shintaro; Hirayanagi, Noriyuki; Sogard, Michael R.

    2003-06-01

    We are now at a major junction in lithography where non-optical lithographies, such as Electron Projection Lithography (EPL) [1], are being introduced. The mask used in EPL is a non-transparent silicon substrate with a thin silicon (~2μm) membrane with openings for electrons to pass through acting as a scatterer. This must be inspected as defects may cause printable defects. Initial mask inspection work has used SEM inspection to find these defects. However, we have historically used optical mask inspection tools, utilising wavelengths at or above what we are using for imaging, to qualify masks. This technology has been increasingly difficult to sustain as we have moved from imaging using mercury lamp based sources to pulsed excimer laser based sources that are not very suited to the inspection imaging. Indeed, review of defects found has moved from optical microscopes to SEM based tools. Inspection tools have also evolved, with the first SEM based mask inspection tools being developed to find the smallest defects, however these have the penalty of very low throughput. We will show the potential of using optical systems for the transmissive inspection of these EPL masks. The high potential of existing tools will be shown together with the need for a next generation of inspection tools. We will show that simulations indicate that an inspection source with 193nm wavelength would be required for the detection of 50nm defects on a mask used to print 70nm dense lines. It will also be shown how the position of the defect within the membrane greatly influences detection as well as the implications of moving to a thinner silicon membrane.

  10. Ground-based intercomparison of two isoprene measurement techniques

    Directory of Open Access Journals (Sweden)

    E. Leibrock

    2003-01-01

    Full Text Available An informal intercomparison of two isoprene (C5H8 measurement techniques was carried out during Fall of 1998 at a field site located approximately 3 km west of Boulder, Colorado, USA. A new chemical ionization mass spectrometric technique (CIMS was compared to a well-established gas chromatographic technique (GC. The CIMS technique utilized benzene cation chemistry to ionize isoprene. The isoprene levels measured by the CIMS were often larger than those obtained with the GC. The results indicate that the CIMS technique suffered from an anthropogenic interference associated with air masses from the Denver, CO metropolitan area as well as an additional interference occurring in clean conditions. However, the CIMS technique is also demonstrated to be sensitive and fast. Especially after introduction of a tandem mass spectrometric technique, it is therefore a candidate for isoprene measurements in remote environments near isoprene sources.

  11. Development of NRU reflector wall inspection system

    Energy Technology Data Exchange (ETDEWEB)

    Lumsden, R.H.; Luloff, B.V.; Zahn, N.; Simpson, N., E-mail: lumsdenr@aecl.ca [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2013-06-15

    In 2009 May, the National Research Universal (NRU) calandria leaked. During the next year, the calandria was inspected with six new Non-Destructive Evaluation (NDE) techniques to determine the extent of the corrosion, repaired, and finally the repair was inspected with four additional new NDE techniques before the reactor was returned to service. The calandria is surrounded by a light-water reflector vessel fabricated from the same material as the calandria vessel. Concerns that the same corrosion mechanism had damaged the reflector vessel led to the development of a system to inspect the full circumference of the reflector wall for corrosion damage. The inspection region could only be accessed through 64 mm diameter ports, was 10 m below the port, and had to be inspected from the corroded surface. The ultrasonic technique was designed to produce a closely spaced wall thickness (WT) grid over an area of approximately 5 m2 on the corroded surface using a very small probe holder. This paper describes the Reflector Wall Inspection (RWI) development project and the system that resulted. (author)

  12. Bare PCB inspection system with SV-GMR sensor eddy-current testing probe

    OpenAIRE

    Chomsuwan, K.; Yamada, Sotoshi; Iwahara, Masayoshi

    2007-01-01

    This paper describes bare printed circuit board (PCB) inspection based on eddy-current testing (ECT) technique with high scanning speed. A high-frequency ECT probe composed of a meander coil as an exciting coil and the spin-valve giant magnetoresistance (SV-GMR) sensor was fabricated and is proposed. The ECT probe was designed based on crack inspection over flat surface, especially suitable for microdefect detection on high-density bare PCB. The ECT signal detected by the SV-GMR sensor was ac...

  13. Signal Processing Techniques for Silicon Drift Detector Based X-Ray Spectrometer for Planatary Instruments

    Science.gov (United States)

    Patel, A.; Shanmugam, M.; Ladiya, T.

    2016-10-01

    We are developing SDD based x-ray spectrometer using various pulse height analysis techniques. This study will help to identify the proper processing technique based on instrument specifications which can be used for future scientific missions.

  14. 40 CFR 264.254 - Monitoring and inspection.

    Science.gov (United States)

    2010-07-01

    ... liners and covers must be inspected to ensure tight seams and joints and the absence of tears, punctures, or blisters; and (2) Soil-based and admixed liners and covers must be inspected for imperfections... Waste Piles § 264.254 Monitoring and inspection. (a) During construction or installation, liners...

  15. Orientation of student entrepreneurial practices based on administrative techniques

    Directory of Open Access Journals (Sweden)

    Héctor Horacio Murcia Cabra

    2005-07-01

    Full Text Available As part of the second phase of the research project «Application of a creativity model to update the teaching of the administration in Colombian agricultural entrepreneurial systems» it was decided to re-enforce student planning and execution of the students of the Agricultural business Administration Faculty of La Salle University. Those finishing their studies were given special attention. The plan of action was initiated in the second semester of 2003. It was initially defined as a model of entrepreneurial strengthening based on a coherent methodology that included the most recent administration and management techniques. Later, the applicability of this model was tested in some organizations of the agricultural sector that had asked for support in their planning processes. Through an investigation-action process the methodology was redefined in order to arrive at a final model that could be used by faculty students and graduates. The results obtained were applied to the teaching of Entrepreneurial Laboratory of ninth semester students with the hope of improving administrative support to agricultural enterprises. Following this procedure more than 100 students and 200 agricultural producers have applied this procedure between June 2003 and July 2005. The methodology used and the results obtained are presented in this article.

  16. Image content authentication technique based on Laplacian Pyramid

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This paper proposes a technique of image content authentication based on the Laplacian Pyramid to verify the authenticity of image content.First,the image is decomposed into Laplacian Pyramid before the transformation.Next,the smooth and detail properties of the original image are analyzed according to the Laplacian Pyramid,and the properties are classified and encoded to get the corresponding characteristic values.Then,the signature derived from the encrypted characteristic values is embedded in the original image as a watermark.After the reception,the characteristic values of the received image are compared with the watermark drawn out from the image.The algorithm automatically identifies whether the content is tampered by means of morphologic filtration.The information of tampered location is Presented at the same time.Experimental results show that the pro posed authentication algorithm can effectively detect the event and location when the original image content is tampered.Moreover,it can tolerate some distortions produced by compression,filtration and noise degradation.

  17. Research on technique of wavefront retrieval based on Foucault test

    Science.gov (United States)

    Yuan, Lvjun; Wu, Zhonghua

    2010-05-01

    During finely grinding the best fit sphere and initial stage of polishing, surface error of large aperture aspheric mirrors is too big to test using common interferometer. Foucault test is widely used in fabricating large aperture mirrors. However, the optical path is disturbed seriously by air turbulence, and changes of light and dark zones can not be identified, which often lowers people's judging ability and results in making mistake to diagnose surface error of the whole mirror. To solve the problem, the research presents wavefront retrieval based on Foucault test through digital image processing and quantitative calculation. Firstly, real Foucault image can be gained through collecting a variety of images by CCD, and then average these image to eliminate air turbulence. Secondly, gray values are converted into surface error values through principle derivation, mathematical modeling, and software programming. Thirdly, linear deviation brought by defocus should be removed by least-square method to get real surface error. At last, according to real surface error, plot wavefront map, gray contour map and corresponding pseudo color contour map. The experimental results indicates that the three-dimensional wavefront map and two-dimensional contour map are able to accurately and intuitively show surface error on the whole mirrors under test, and they are beneficial to grasp surface error as a whole. The technique can be used to guide the fabrication of large aperture and long focal mirrors during grinding and initial stage of polishing the aspheric surface, which improves fabricating efficiency and precision greatly.

  18. A formal model for integrity protection based on DTE technique

    Institute of Scientific and Technical Information of China (English)

    JI Qingguang; QING Sihan; HE Yeping

    2006-01-01

    In order to provide integrity protection for the secure operating system to satisfy the structured protection class' requirements, a DTE technique based integrity protection formalization model is proposed after the implications and structures of the integrity policy have been analyzed in detail. This model consists of some basic rules for configuring DTE and a state transition model, which are used to instruct how the domains and types are set, and how security invariants obtained from initial configuration are maintained in the process of system transition respectively. In this model, ten invariants are introduced, especially, some new invariants dealing with information flow are proposed, and their relations with corresponding invariants described in literatures are also discussed.The thirteen transition rules with well-formed atomicity are presented in a well-operational manner. The basic security theorems correspond to these invariants and transition rules are proved. The rationalities for proposing the invariants are further annotated via analyzing the differences between this model and ones described in literatures. At last but not least, future works are prospected, especially, it is pointed out that it is possible to use this model to analyze SE-Linux security.

  19. Biofunctionalization of Si nanowires using a solution based technique

    Science.gov (United States)

    Williams, Elissa H.; Davydov, Albert V.; Oleshko, Vladimir P.; Lin, Nancy J.; Steffens, Kristen L.; Manocchi, Amy K.; Krylyuk, Sergiy; Rao, Mulpuri V.; Schreifels, John A.

    2012-10-01

    Here we present a solution based functionalization technique for streptavidin (SA) protein conjugation to silicon nanowires (Si NWs). Si NWs, with a diameter of 110 nm to 130 nm and a length of 5 μm to 10 μm, were functionalized with 3-aminopropyltriethoxysilane (APTES) followed by biotin for the selective attachment of SA. High-resolution transmission electron microscopy (HRTEM) and atomic force microscopy (AFM) showed that the Si NWs were conformally coated with 20 nm to 30 nm thick APTES, biotin, and SA layers upon functionalization. Successful attachment of each bio/organic layer was confirmed by X-ray photoelectron spectroscopy (XPS) and fluorescence microscopy. Fluorescence microscopy also demonstrated that there was an undesirable non-specific binding of the SA protein as well as a control protein, bovine serum albumin (BSA), to the APTES-coated Si NWs. However, inhibition of BSA binding and enhancement of SA binding were achieved following the biotinylation step. The biofunctionalized Si NWs show potential as label-free biosensing platforms for the specific and selective detection of biomolecules.

  20. Channel Based Adaptive Rate Control Technique for MANET

    Directory of Open Access Journals (Sweden)

    R. Bharathiraja

    2014-04-01

    Full Text Available In Mobile Ad hoc Networks (MANET, most of the existing works does not consider energy efficiency during selecting the appropriate route. Hence in MANET selecting the appropriate route and also maintaining energy efficiency is very important. Hence in order to overcome these issues, in this study we propose Channel Based Adaptive Rate Control technique for MANET. Here the most appropriate links is selected to transmit the node with efficient power consumption. The node broadcasts the information of its outgoing and incoming links in NSET instead of waiting for the feedback informattion from receiver. The number of packets transmitted in a channel access time is maximized by implementing the benefit ratio in rate selection algorithm. This study also introduces node cooperation, in node cooperation the node determines the feasibility of new rate setting determined by rate selection algorithm and it carries out new setting if it is feasible by following help, ack, reject and accept method. By simulation results we show that the proposed approach is power efficient and also increases the trasmission rate.

  1. Formal Verification Techniques Based on Boolean Satisfiability Problem

    Institute of Scientific and Technical Information of China (English)

    Xiao-Wei Li; Guang-Hui Li; Ming Shao

    2005-01-01

    This paper exploits Boolean satisfiability problem in equivalence checking and model checking respectively. A combinational equivalence checking method based on incremental satisfiability is presented. This method chooses the can didate equivalent pairs with some new techniques, and uses incremental satisfiability algorithm to improve its performance. By substituting the internal equivalent pairs and converting the equivalence relations into conjunctive normal form (CNF) formulas, this approach can avoid the false negatives, and reduce the search space of SAT procedure. Experimental results on ISCAS'85 benchmark circuits show that, the presented approach is faster and more robust than those existed in literature.This paper also presents an algorithm for extracting of unsatisfiable core, which has an important application in abstraction and refinement for model checking to alleviate the state space explosion bottleneck. The error of approximate extraction is analyzed by means of simulation. An analysis reveals that an interesting phenomenon occurs, with the increasing density of the formula, the average error of the extraction is decreasing. An exact extraction approach for MU subformula, referred to as pre-assignment algorithm, is proposed. Both theoretical analysis and experimental results show that it is more efficient.

  2. WORMHOLE ATTACK MITIGATION IN MANET: A CLUSTER BASED AVOIDANCE TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Subhashis Banerjee

    2014-01-01

    Full Text Available A Mobile Ad-Hoc Network (MANET is a self configuring, infrastructure less network of mobile devices connected by wireless links. Loopholes like wireless medium, lack of a fixed infrastructure, dynamic topology, rapid deployment practices, and the hostile environments in which they may be deployed, make MANET vulnerable to a wide range of security attacks and Wormhole attack is one of them. During this attack a malicious node captures packets from one location in the network, and tunnels them to another colluding malicious node at a distant point, which replays them locally. This paper presents a cluster based Wormhole attack avoidance technique. The concept of hierarchical clustering with a novel hierarchical 32- bit node addressing scheme is used for avoiding the attacking path during the route discovery phase of the DSR protocol, which is considered as the under lying routing protocol. Pinpointing the location of the wormhole nodes in the case of exposed attack is also given by using this method.

  3. Structuring Task-based Interaction through Collaborative Learning Techniques (2)

    Institute of Scientific and Technical Information of China (English)

    William Littlewood

    2004-01-01

    @@ Techniques for collaborative learning In this section the focus will move from broad strategies to specific techniques (often also called "structures") through which the strategies can be realized. It gives a selection of techniques which have proved (in my own experience as well as that of others) particularly useful in pro-viding contexts for practice, exploration and /or interaction in the second language classroom.

  4. Weighted graph based ordering techniques for preconditioned conjugate gradient methods

    Science.gov (United States)

    Clift, Simon S.; Tang, Wei-Pai

    1994-01-01

    We describe the basis of a matrix ordering heuristic for improving the incomplete factorization used in preconditioned conjugate gradient techniques applied to anisotropic PDE's. Several new matrix ordering techniques, derived from well-known algorithms in combinatorial graph theory, which attempt to implement this heuristic, are described. These ordering techniques are tested against a number of matrices arising from linear anisotropic PDE's, and compared with other matrix ordering techniques. A variation of RCM is shown to generally improve the quality of incomplete factorization preconditioners.

  5. Adoption of farm-based irrigation water-saving techniques in the Guanzhong Plain, China

    NARCIS (Netherlands)

    Tang, Jianjun; Folmer, Henk; Xue, Jianhong

    2016-01-01

    This article analyses adoption of farm-based irrigation water saving techniques, based on a cross-sectional data set of 357 farmers in the Guanzhong Plain, China. Approximately 83% of the farmers use at least one farm-based water-saving technique. However, the traditional, inefficient techniques bor

  6. Evidence-based surgical techniques for caesarean section

    DEFF Research Database (Denmark)

    Aabakke, Anna J M; Secher, Niels Jørgen; Krebs, Lone

    2014-01-01

    Caesarean section (CS) is a common surgical procedure, and in Denmark 21% of deliveries is by CS. There is an increasing amount of scientific evidence to support the different surgical techniques used at CS. This article reviews the literature regarding CS techniques. There is still a lack...

  7. A Technique for Volumetric CSG Based on Morphology

    DEFF Research Database (Denmark)

    Bærentzen, Jakob Andreas; Christensen, Niels Jørgen

    2001-01-01

    In this paper, a new technique for volumetric CSG is presented. The technique requires the input volumes to correspond to solids which fulfill a voxelization suitability criterion. Assume the CSG operation is union. The volumetric union of two such volumes is defined in terms of the voxelization...

  8. A Lossless Data Hiding Technique based on AES-DWT

    Directory of Open Access Journals (Sweden)

    Gustavo Fernandaacute;ndez Torres2

    2012-09-01

    Full Text Available In this paper we propose a new data hiding technique. The new technique uses steganography and cryptography on images with a size of 256x256 pixels and an 8-bit grayscale format. There are design restrictions such as a fixed-size cover image, and reconstruction without error of the hidden image. The steganography technique uses a Haar-DWT (Discrete Wavelet Transform with hard thresholding and LSB (Less Significant Bit technique on the cover image. The algorithms used for compressing and ciphering the secret image are lossless JPG and AES, respectively. The proposed technique is used to generate a stego image which provides a double type of security that is robust against attacks. Results are reported for different thresholds levels in terms of PSNR.

  9. A Review of Automated Inspection Planning Systems for Use with an Integrated Manufacturing System

    Institute of Scientific and Technical Information of China (English)

    A; Ajmal; D; S; Manolache

    2002-01-01

    The paper outlines a comprehensive state-of-the- ar t review of automated inspection planning systems for use with a co-ordinate-m easuring machine (CMM) and summaries the application methods and techniques used in automation of inspection planning for CMMs. A classification of the automate d inspection planning systems according to the concept, methodologies and techni ques used for inspection planning tasks has been identified and grouped. The rev iew also outlines the classification of inspection planni...

  10. Feasibility of Magnetostrictive Sensor Inspection of Containments

    Energy Technology Data Exchange (ETDEWEB)

    Kwun, H.

    1999-03-01

    This report describes the results of a study on the feasibility of using guided waves for long-range global inspection of containment metallic pressure boundaries (i.e., steel containments and liners of reinforced concrete containments) in nuclear power plants. Of particular concern in this study was the potential of the guided-wave approach for remotely inspecting the regions that are inaccessible; for example, regions where the metallic pressure boundary is backed by concrete on one or both sides. The study includes a literature review on long-range guided-wave inspection techniques, a modeling study of the behavior of guided waves in plates with different boundary conditions (e.g., freestanding and backed by concrete on one or both sides), and an experimental investigation of the feasibility of a guided-wave technique called ''magnetostrictive sensor (MsS)'' for (1) generating and detecting guided waves in plates and (2) detecting a defect over a long range. Results of the study showed (1) that it is feasible to achieve long-range global inspection of plates, including regions that are inaccessible, using low-frequency guided waves and (2) that the MsS technique is well suited for this application. Recommendations are made to further test and develop the MsS technique for practical implementation for containment inspection in nuclear power plants.

  11. Application of Ultrasonic Time of Flight Diffraction Inspection Techniques for T-type Welding Seam%超声TOFD检测技术在T型焊缝中的应用

    Institute of Scientific and Technical Information of China (English)

    王勇

    2016-01-01

    TOFD检测技术是一种高效快捷的检测焊缝的超声技术。文章采用TOFD检测方法对T型焊缝进行探伤,提出了TOFD对称扫查方法和非对称扫查方法,2种方法结合实现了对T型焊缝的全面检测。该TOFD检测方法探伤速度快,缺陷检出率高,能实时成像,并能对缺陷进行快速分析。%The ultrasonic Time of Flight Diffraction (TOFD) technique is a fast and efficient testing technology. The TOFD symmetric scanning method and asymmetric scanning method are proposed in this paper. The combination of TOFD symmetric and asymmetric scanning method are used to have a comprehensive inspection for T-type welding seam. These TOFD detection methods have faster detection speed and higher defect detection rate and can help to analyze defects quickly.

  12. Industrial applications of automated X-ray inspection

    Science.gov (United States)

    Shashishekhar, N.

    2015-03-01

    Many industries require that 100% of manufactured parts be X-ray inspected. Factors such as high production rates, focus on inspection quality, operator fatigue and inspection cost reduction translate to an increasing need for automating the inspection process. Automated X-ray inspection involves the use of image processing algorithms and computer software for analysis and interpretation of X-ray images. This paper presents industrial applications and illustrative case studies of automated X-ray inspection in areas such as automotive castings, fuel plates, air-bag inflators and tires. It is usually necessary to employ application-specific automated inspection strategies and techniques, since each application has unique characteristics and interpretation requirements.

  13. Improvement of the reliability on nondestructive inspection

    Energy Technology Data Exchange (ETDEWEB)

    Song, Sung Jin; Kim, Young H. [Sungkyunkwan Univ., Suwon (Korea, Republic of); Lee, Hyang Beom [Soongsil Univ., Seoul (Korea, Republic of); Shin, Young Kil [Kunsan National Univ., Gunsan (Korea, Republic of); Jung, Hyun Jo [Wonkwang Univ., Iksan (Korea, Republic of); Park, Ik Keun; Park, Eun Soo [Seoul Nationl Univ., Seoul (Korea, Republic of)

    2002-03-15

    Retaining reliabilities of nondestructive testing is essential for the life-time maintenance of Nuclear Power Plant. The nondestructive testing methods which are frequently used in the Nuclear Power Plant are eddy current testing for the inspection of steam generator tubes and ultrasonic testing for the inspection of weldments. In order to improve reliabilities of ultrasonic testing and eddy current testing, the subjects carried out in this study are as follows : development of BEM analysis technique for ECT of SG tube, development of neural network technique for the intelligent analysis of ECT flaw signals of SG tubes, development of RFECT technology for the inspection of SG tube, FEM analysis of ultrasonic scattering field, evaluation of statistical reliability of PD-RR test of ultrasonic testing and development of multi-Gaussian beam modeling technique to predict accurate signal of signal beam ultrasonic testing with the efficiency in calculation time.

  14. SPAM CLASSIFICATION BASED ON SUPERVISED LEARNING USING MACHINE LEARNING TECHNIQUES

    Directory of Open Access Journals (Sweden)

    T. Hamsapriya

    2011-12-01

    Full Text Available E-mail is one of the most popular and frequently used ways of communication due to its worldwide accessibility, relatively fast message transfer, and low sending cost. The flaws in the e-mail protocols and the increasing amount of electronic business and financial transactions directly contribute to the increase in e-mail-based threats. Email spam is one of the major problems of the today’s Internet, bringing financial damage to companies and annoying individual users. Spam emails are invading users without their consent and filling their mail boxes. They consume more network capacity as well as time in checking and deleting spam mails. The vast majority of Internet users are outspoken in their disdain for spam, although enough of them respond to commercial offers that spam remains a viable source of income to spammers. While most of the users want to do right think to avoid and get rid of spam, they need clear and simple guidelines on how to behave. In spite of all the measures taken to eliminate spam, they are not yet eradicated. Also when the counter measures are over sensitive, even legitimate emails will be eliminated. Among the approaches developed to stop spam, filtering is the one of the most important technique. Many researches in spam filtering have been centered on the more sophisticated classifier-related issues. In recent days, Machine learning for spam classification is an important research issue. The effectiveness of the proposed work is explores and identifies the use of different learning algorithms for classifying spam messages from e-mail. A comparative analysis among the algorithms has also been presented.

  15. Bio-inspired computational techniques based on advanced condition monitoring

    Institute of Scientific and Technical Information of China (English)

    Su Liangcheng; He Shan; Li Xiaoli; Li Xinglin

    2011-01-01

    The application of bio-inspired computational techniques to the field of condition monitoring is addressed.First, the bio-inspired computational techniques are briefly addressed; the advantages and disadvantages of these computational methods are made clear. Then, the roles of condition monitoring in the predictive maintenance and failures prediction and the development trends of condition monitoring are discussed. Finally, a case study on the condition monitoring of grinding machine is described, which shows the application of bio-inspired computational technique to a practical condition monitoring system.

  16. A New Image Steganography Based On First Component Alteration Technique

    CERN Document Server

    Kaur, Amanpreet; Sikka, Geeta

    2010-01-01

    In this paper, A new image steganography scheme is proposed which is a kind of spatial domain technique. In order to hide secret data in cover-image, the first component alteration technique is used. Techniques used so far focuses only on the two or four bits of a pixel in a image (at the most five bits at the edge of an image) which results in less peak to signal noise ratio and high root mean square error. In this technique, 8 bits of blue components of pixels are replaced with secret data bits. Proposed scheme can embed more data than previous schemes and shows better image quality. To prove this scheme, several experiments are performed, and are compared the experimental results with the related previous works.

  17. A New Image Steganography Based On First Component Alteration Technique

    Directory of Open Access Journals (Sweden)

    Amanpreet Kaur

    2009-12-01

    Full Text Available In this paper, A new image steganography scheme is proposed which is a kind of spatial domain technique. In order to hide secret data in cover-image, the first component alteration technique is used. Techniques used so far focuses only on the two or four bits of a pixel in a image (at the most five bits at the edge of an image which results in less peak to signal noise ratio and high root mean square error. In this technique, 8 bits of blue components of pixels are replaced with secret data bits. Proposed scheme can embed more data than previous schemes and shows better image quality. To prove this scheme, several experiments are performed, and are compared the experimental results with the related previous works.Keywords—image; mean square error; Peak signal to noise ratio; steganography;

  18. SNMP Based Network Optimization Technique Using Genetic Algorithms

    Directory of Open Access Journals (Sweden)

    M. Mohamed Surputheen

    2012-03-01

    Full Text Available Genetic Algorithms (GAs has innumerable applications through the optimization techniques and network optimization is one of them. SNMP (Simple Network Management Protocol is used as the basic network protocol for monitoring the network activities health of the systems. This paper deals with adding Intelligence to the various aspects of SNMP by adding optimization techniques derived out of genetic algorithms, which enhances the performance of SNMP processes like routing.

  19. EDM COLLABORATIVE MANUFACTURING SYSTEM BASED ON MULTI-AGENT TECHNIQUES

    Institute of Scientific and Technical Information of China (English)

    Zhao Wansheng; Zhao Jinzhi; Song Yinghui; Yang Xiaodong

    2003-01-01

    A framework for building EDM collaborative manufacturing system using multi-agent technology to support organizations characterized by physically distributed, enterprise-wide, heterogeneous intelligent manufacturing system over Internet is proposed. Expert system theory is introduced.Design, manufacturing and technological knowledge are shared using artificial intelligence and web techniques by EDM-CADagent, EDM-CAMagent and EDM-CAPPagent. System structure, design process, network conditions, realization methods and other key techniques are discussed. Instances are also introduced to testify feasibility.

  20. Design and optimization of the low frequency eddy current technique for the volumetric inspection of austenitic small diameter tubes with a wall thickness up to 12 mm; Auslegung und Optimierung des Niederfrequenz-Wirbelstrom-Verfahrens fuer die volumetrische Pruefung von austenitischen Neben- und Kleinleitungen mit Wandstaerken bis 12 mm

    Energy Technology Data Exchange (ETDEWEB)

    Becker, R.; Bessert, S.; Disque, M.; Weiss, R. [Fraunhofer-Institut fuer Zerstoerungsfreie Pruefverfahren, Saarbruecken (Germany)

    1998-11-01

    The low-frequency eddy current technique discussed is a suitable external inspection technique detecting defects at the inner walls of small-diameter tubes and measuring their depths via the ligament. A testing system with optimized sensor lus software for image recording, evaluation, display and documentation is available. The current state of development of the system permits detection and measurement of defects up to 20 mm in size in austenitic inner walls 12.5 mm thick down to a depth of 3 mm. This applies both to the homogenous base metal and the weld with {delta} ferrite. (orig./CB) [Deutsch] Das vorgestellte Niederfrequenz-Wirbelstrom-Verfahren ist geeignet, bei Pruefung von aussen Fehler an der Innenseite von Klein- und Nebenleitungen nachzuweisen und ueber das Ligament deren Tiefe zu bestimmen. Ein entsprechendes Pruefsystem mit optimiertem Sensor und der Software zur Aufnahme, Auswertung, Darstellung und Dokumentation der Wirbelstrom-Urdaten steht zur Verfuegung. Beim jetzigen Entwicklungsstand liegt die Nachweisgrenze fuer einen 20 mm langen Innenfehler in einer 12.5 mm dicken austenitischen Wandung bei einer Fehlertiefe von 3 mm. Dies gilt sowohl fuer den homogenen Grundwerkstoff als auch fuer Schweissgefuege mit {delta}-Ferrit. (orig./MM)

  1. Biogeosystem technique as a base of Sustainable Irrigated Agriculture

    Science.gov (United States)

    Batukaev, Abdulmalik

    2016-04-01

    The world water strategy is to be changed because the current imitational gravitational frontal isotropic-continual paradigm of irrigation is not sustainable. This paradigm causes excessive consumption of fresh water - global deficit - up to 4-15 times, adverse effects on soils and landscapes. Current methods of irrigation does not control the water spread throughout the soil continuum. The preferable downward fluxes of irrigation water are forming, up to 70% and more of water supply loses into vadose zone. The moisture of irrigated soil is high, soil loses structure in the process of granulometric fractions flotation decomposition, the stomatal apparatus of plant leaf is fully open, transpiration rate is maximal. We propose the Biogeosystem technique - the transcendental, uncommon and non-imitating methods for Sustainable Natural Resources Management. New paradigm of irrigation is based on the intra-soil pulse discrete method of water supply into the soil continuum by injection in small discrete portions. Individual volume of water is supplied as a vertical cylinder of soil preliminary watering. The cylinder position in soil is at depth form 10 to 30 cm. Diameter of cylinder is 1-2 cm. Within 5-10 min after injection the water spreads from the cylinder of preliminary watering into surrounding soil by capillary, film and vapor transfer. Small amount of water is transferred gravitationally to the depth of 35-40 cm. The soil watering cylinder position in soil profile is at depth of 5-50 cm, diameter of the cylinder is 2-4 cm. Lateral distance between next cylinders along the plant raw is 10-15 cm. The soil carcass which is surrounding the cylinder of non-watered soil remains relatively dry and mechanically stable. After water injection the structure of soil in cylinder restores quickly because of no compression from the stable adjoining volume of soil and soil structure memory. The mean soil thermodynamic water potential of watered zone is -0.2 MPa. At this potential

  2. ANNUAL RADIOACTIVE WASTE TANK INSPECTION PROGRAM 2009

    Energy Technology Data Exchange (ETDEWEB)

    West, B.; Waltz, R.

    2010-06-21

    Aqueous radioactive wastes from Savannah River Site (SRS) separations and vitrification processes are contained in large underground carbon steel tanks. Inspections made during 2009 to evaluate these vessels and other waste handling facilities along with evaluations based on data from previous inspections are the subject of this report. The 2009 inspection program revealed that the structural integrity and waste confinement capability of the Savannah River Site waste tanks were maintained. All inspections scheduled per LWO-LWE-2008-00423, HLW Tank Farm Inspection Plan for 2009, were completed. All Ultrasonic measurements (UT) performed in 2009 met the requirements of C-ESG-00006, In-Service Inspection Program for High Level Waste Tanks, Rev. 1, and WSRC-TR-2002-00061, Rev.4. UT inspections were performed on Tank 29 and the findings are documented in SRNL-STI-2009-00559, Tank Inspection NDE Results for Fiscal Year 2009, Waste Tank 29. Post chemical cleaning UT measurements were made in Tank 6 and the results are documented in SRNL-STI-2009-00560, Tank Inspection NDE Results Tank 6, Including Summary of Waste Removal Support Activities in Tanks 5 and 6. A total of 6669 photographs were made and 1276 visual and video inspections were performed during 2009. Twenty-Two new leaksites were identified in 2009. The locations of these leaksites are documented in C-ESR-G-00003, SRS High Level Waste Tank Leaksite Information, Rev.4. Fifteen leaksites at Tank 5 were documented during tank wall/annulus cleaning activities. Five leaksites at Tank 6 were documented during tank wall/annulus cleaning activities. Two new leaksites were identified at Tank 19 during waste removal activities. Previously documented leaksites were reactivated at Tanks 5 and 12 during waste removal activities. Also, a very small amount of additional leakage from a previously identified leaksite at Tank 14 was observed.

  3. Retention of denture bases fabricated by three different processing techniques – An in vivo study

    Science.gov (United States)

    Chalapathi Kumar, V. H.; Surapaneni, Hemchand; Ravikiran, V.; Chandra, B. Sarat; Balusu, Srilatha; Reddy, V. Naveen

    2016-01-01

    Aim: Distortion due to Polymerization shrinkage compromises the retention. To evaluate the amount of retention of denture bases fabricated by conventional, anchorized, and injection molding polymerization techniques. Materials and Methods: Ten completely edentulous patients were selected, impressions were made, and master cast obtained was duplicated to fabricate denture bases by three polymerization techniques. Loop was attached to the finished denture bases to estimate the force required to dislodge them by retention apparatus. Readings were subjected to nonparametric Friedman two-way analysis of variance followed by Bonferroni correction methods and Wilcoxon matched-pairs signed-ranks test. Results: Denture bases fabricated by injection molding (3740 g), anchorized techniques (2913 g) recorded greater retention values than conventional technique (2468 g). Significant difference was seen between these techniques. Conclusions: Denture bases obtained by injection molding polymerization technique exhibited maximum retention, followed by anchorized technique, and least retention was seen in conventional molding technique. PMID:27382542

  4. Skull base tumours part I: Imaging technique, anatomy and anterior skull base tumours

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Alexandra [Instituto Portugues de Oncologia Francisco Gentil, Centro de Lisboa, Servico de Radiologia, Rua Professor Lima Basto, 1093 Lisboa Codex (Portugal)], E-mail: borgesalexandra@clix.pt

    2008-06-15

    Advances in cross-sectional imaging, surgical technique and adjuvant treatment have largely contributed to ameliorate the prognosis, lessen the morbidity and mortality of patients with skull base tumours and to the growing medical investment in the management of these patients. Because clinical assessment of the skull base is limited, cross-sectional imaging became indispensable in the diagnosis, treatment planning and follow-up of patients with suspected skull base pathology and the radiologist is increasingly responsible for the fate of these patients. This review will focus on the advances in imaging technique; contribution to patient's management and on the imaging features of the most common tumours affecting the anterior skull base. Emphasis is given to a systematic approach to skull base pathology based upon an anatomic division taking into account the major tissue constituents in each skull base compartment. The most relevant information that should be conveyed to surgeons and radiation oncologists involved in patient's management will be discussed.

  5. Galois Field Based Very Fast and Compact Error Correcting Technique

    Directory of Open Access Journals (Sweden)

    Alin Sindhu.A,

    2014-01-01

    Full Text Available As the technology is improving the memory devices are becoming larger, so powerful error correction codes are needed. Error correction codes are commonly used to protect memories from soft errors, which change the logical value of memory cells without damaging the circuit. These codes can correct a large number of errors, but generally require complex decoders. In order to avoid this decoding complexity, in this project it uses Euclidean geometry LDPC codes with one step majority decoding technique. This method detects words having error in the first iteration of the majority logic decoding process and reduces the decoding time by stopping the decoding process when no errors are detected as well as reduces the memory access time. And the result obtained through this technique also proves that it is an effective and compact error correcting technique.

  6. A novel technique for extracting clouds base height using ground based imaging

    Directory of Open Access Journals (Sweden)

    E. Hirsch

    2011-01-01

    Full Text Available The height of a cloud in the atmospheric column is a key parameter in its characterization. Several remote sensing techniques (passive and active, either ground-based or on space-borne platforms and in-situ measurements are routinely used in order to estimate top and base heights of clouds. In this article we present a novel method that combines thermal imaging from the ground and sounded wind profile in order to derive the cloud base height. This method is independent of cloud types, making it efficient for both low boundary layer and high clouds. In addition, using thermal imaging ensures extraction of clouds' features during daytime as well as at nighttime. The proposed technique was validated by comparison to active sounding by ceilometers (which is a standard ground based method, to lifted condensation level (LCL calculations, and to MODIS products obtained from space. As all passive remote sensing techniques, the proposed method extracts only the height of the lowest cloud layer, thus upper cloud layers are not detected. Nevertheless, the information derived from this method can be complementary to space-borne cloud top measurements when deep-convective clouds are present. Unlike techniques such as LCL, this method is not limited to boundary layer clouds, and can extract the cloud base height at any level, as long as sufficient thermal contrast exists between the radiative temperatures of the cloud and its surrounding air parcel. Another advantage of the proposed method is its simplicity and modest power needs, making it particularly suitable for field measurements and deployment at remote locations. Our method can be further simplified for use with visible CCD or CMOS camera (although nighttime clouds will not be observed.

  7. RP-based Abrading Technique for Graphite EDM Electrode

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Traditional processes for machining mold cavities are lengthy and costly. EDM (electro-discharge machining) is the most commonly used technique to obtain complex mold cavities. However, some electrodes are difficult to fabricate because of the complexity. Applying RP (rapid prototyping) technology to fabricate an abrading tool which is used to abrade graphite EDM electrodes, the cost and cycle time can greatly be reduced. The paper describes the work being conducted in this area by the authors. This technique will find widespread application in rapid steel mold manufacturing.

  8. Advanced High Speed Roller Bearing Inspection Techniques

    Science.gov (United States)

    1977-05-01

    Parametrics New York, New York S. Orange, Connecticut Modern Controls, Inc. Peerless Nuclear Corporation Minneapolis, Minnesota Stamford, Connecticut Monitor...California Reticon Slocomb, J. T., Co. Sunnyvale, California So. Glastonbury, Connecticut A6 Solid State Electronics Corporation Texas Instruments Inc

  9. Response Time Comparisons among Four Base Running Starting Techniques in Slow Pitch Softball.

    Science.gov (United States)

    Israel, Richard G.; Brown, Rodney L.

    1981-01-01

    Response times among four starting techniques (cross-over step, jab step, standing sprinter's start, and momentum start) were compared. The results suggest that the momentum start was the fastest starting technique for optimum speed in running bases. (FG)

  10. A Predicate Based Fault Localization Technique Based On Test Case Reduction

    Directory of Open Access Journals (Sweden)

    Rohit Mishra

    2015-08-01

    Full Text Available ABSTRACT In todays world software testing with statistical fault localization technique is one of most tedious expensive and time consuming activity. In faulty program a program element contrast dynamic spectra that estimate location of fault. There may have negative impact from coincidental correctness with these technique because in non failed run the fault can also be triggered out and if so disturb the assessment of fault location. Now eliminating of confounding rules on the recognizing the accuracy. In this paper coincidental correctness which is an effective interface is the reason of success of fault location. We can find out fault predicates by distribution overlapping of dynamic spectrum in failed runs and non failed runs and slacken the area by referencing the inter class distances of spectra to clamp the less suspicious candidate. After that we apply coverage matrix base reduction approach to reduce the test cases of that program and locate the fault in that program. Finally empirical result shows that our technique outshine with previous existing predicate based fault localization technique with test case reduction.

  11. DSPI system based on spatial carrier phase shifting technique

    Science.gov (United States)

    Wang, Yonghong; Li, Junrui; Sun, Jianfei; Yang, Lianxiang

    2013-10-01

    Digital Speckle Pattern Interferometry (DSPI) is an optical method for measuring small displacement and deformation. It allows whole field, non-contacting measurement of micro deformation. Traditional Temporal phase shifting has been used for quantitative analyses in DSPI. The technique requires the recording of at least three phase-shifted interferograms, which must be taken sequentially. This can lead to disturbances by thermal and mechanical fluctuations during the required recording time. In addition, fast object deformations cannot be detected. In this paper a DSPI system using Spatial Carrier Phase Shifting (SCPS) technique is introduced, which is useful for extracting quantitative displacement data from the system with only two interferograms. The sensitive direction of this system refers to the illumination direction and observation direction. The frequencies of the spatial carrier relates to the angle between reference light and observation direction. Fourier transform is adopted in the digital evaluation to filter out the frequencies links to the deformation of testing object. The phase is obtained from the complex matrix formed by inverse Fourier transform, and the phase difference and deformation are calculated subsequently. Comparing with conventional temporal phase shifting, the technique can achieve measuring the vibration and transient deformation of testing object. Experiment set-ups and results are presented in this paper, and the experiment results have shown the effectiveness and advantages of the SCPS technique.

  12. A novel image inpainting technique based on median diffusion

    Indian Academy of Sciences (India)

    Rajkumar L Biradar; Vinayadatt V Kohir

    2013-08-01

    Image inpainting is the technique of filling-in the missing regions and removing unwanted objects from an image by diffusing the pixel information from the neighbourhood pixels. Image inpainting techniques are in use over a long time for various applications like removal of scratches, restoring damaged/missing portions or removal of objects from the images, etc. In this study, we present a simple, yet unexplored (digital) image inpainting technique using median filter, one of the most popular nonlinear (order statistics) filters. The median is maximum likelihood estimate of location for the Laplacian distribution. Hence, the proposed algorithm diffuses median value of pixels from the exterior area into the inner area to be inpainted. The median filter preserves the edge which is an important property needed to inpaint edges. This technique is stable. Experimental results show remarkable improvements and works for homogeneous as well as heterogeneous background. PSNR (quantitative assessment) is used to compare inpainting results.

  13. Kernel-Based Discriminant Techniques for Educational Placement

    Science.gov (United States)

    Lin, Miao-hsiang; Huang, Su-yun; Chang, Yuan-chin

    2004-01-01

    This article considers the problem of educational placement. Several discriminant techniques are applied to a data set from a survey project of science ability. A profile vector for each student consists of five science-educational indicators. The students are intended to be placed into three reference groups: advanced, regular, and remedial.…

  14. MRA Based Efficient Database Storing and Fast Querying Technique

    Directory of Open Access Journals (Sweden)

    Mitko Kostov

    2017-02-01

    Full Text Available In this paper we consider a specific way of organizing 1D signals or 2D image databases, such that a more efficient storage and faster querying is achieved. A multiresolution technique of data processing is used in order of saving the most significant processed data.

  15. Design and implementation of the safety inspection system based on intelligent mobile terminal%基于智能移动终端的安全检查系统设计与实现

    Institute of Scientific and Technical Information of China (English)

    樊新; 高曙

    2012-01-01

    为了提高矿山安全检查信息化水平,提出了一种基于智能移动终端的安全检查系统的设计与实现方案。该方案通过手持终端采集安全检查信息并将其保存到终端SQLite数据库中,同时利用Socket编程使终端安全检查信息通过WiFi无线通信技术传输到服务器数据库中。通过分析矿山安全检查信息来确定矿山的安全状况,从而实现对矿山的安全管理。%In order to improve the information level of mine safety information, design and implementation of safety inspection system based on intelligent mobile terminal was presented. The precept was that hand-held terminals collected safety inspection in- formation and saved it to terminal SQLite database, at the same time taking advantage of Socket programming, the terminal security inspection information transmitted to server database by the WiFi wireless communication technology. Through the analysis of safety inspection information to determine the safety status of mine, thus realized the security inspection for the mine.

  16. Signal Station Inspection Reports

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Handwritten reports resulting from detailed inspections of US Army Signal Service Stations, 1871-1889. Features reported included instrument exposure and condition,...

  17. RBI - Risk Based Inspection: new concept applied to management of FPSOs (Floating, Production and Storage Offshore) structural integrity; IBR-Inspecao baseada em risco: um novo conceito aplicado a gestao da integridade estrutural de FPSOs

    Energy Technology Data Exchange (ETDEWEB)

    Farias, Bruno de; Figueiredo, Eduardo; Luiz, Marcio [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Meurer, Gustavo; Duarte, Romulo; Belligotti, Rufo; Krzonkalla, Viviane [ABS Consulting, Rio de Janeiro, RJ (Brazil)

    2008-07-01

    Due to the difficulties of adapting the plan of inspection, typical of oil tankers, the units of the FPSO, began to occur large periods of unavailability of the cargo tanks. Also, with the expansion of the fleet, began to notice a difficulty in meeting the plan of inspection of the FPSO's hull. To improve the management of structural integrity of its FPSO's, PETROBRAS aims to ABS Consulting with the development and implementation of Risk-Based Inspection, known as RBI. This concept is applicable to various branches of industry. The companies began their implementation of oil by refineries. The development application for a ship's hull is recent and PETROBRAS is one of the first companies to implement the IBR for monitoring of the FPSO hull. (author)

  18. Decision Analysis Technique

    Directory of Open Access Journals (Sweden)

    Hammad Dabo Baba

    2014-01-01

    Full Text Available One of the most significant step in building structure maintenance decision is the physical inspection of the facility to be maintained. The physical inspection involved cursory assessment of the structure and ratings of the identified defects based on expert evaluation. The objective of this paper is to describe present a novel approach to prioritizing the criticality of physical defects in a residential building system using multi criteria decision analysis approach. A residential building constructed in 1985 was considered in this study. Four criteria which includes; Physical Condition of the building system (PC, Effect on Asset (EA, effect on Occupants (EO and Maintenance Cost (MC are considered in the inspection. The building was divided in to nine systems regarded as alternatives. Expert's choice software was used in comparing the importance of the criteria against the main objective, whereas structured Proforma was used in quantifying the defects observed on all building systems against each criteria. The defects severity score of each building system was identified and later multiplied by the weight of the criteria and final hierarchy was derived. The final ranking indicates that, electrical system was considered the most critical system with a risk value of 0.134 while ceiling system scored the lowest risk value of 0.066. The technique is often used in prioritizing mechanical equipment for maintenance planning. However, result of this study indicates that the technique could be used in prioritizing building systems for maintenance planning

  19. A Review On Segmentation Based Image Compression Techniques

    Directory of Open Access Journals (Sweden)

    S.Thayammal

    2013-11-01

    Full Text Available Abstract -The storage and transmission of imagery become more challenging task in the current scenario of multimedia applications. Hence, an efficient compression scheme is highly essential for imagery, which reduces the requirement of storage medium and transmission bandwidth. Not only improvement in performance and also the compression techniques must converge quickly in order to apply them for real time applications. There are various algorithms have been done in image compression, but everyone has its own pros and cons. Here, an extensive analysis between existing methods is performed. Also, the use of existing works is highlighted, for developing the novel techniques which face the challenging task of image storage and transmission in multimedia applications.

  20. Wavelet-Based Techniques for the Gamma-Ray Sky

    CERN Document Server

    McDermott, Samuel D; Cholis, Ilias; Lee, Samuel K

    2015-01-01

    We demonstrate how the image analysis technique of wavelet decomposition can be applied to the gamma-ray sky to separate emission on different angular scales. New structures on scales that differ from the scales of the conventional astrophysical foreground and background uncertainties can be robustly extracted, allowing a model-independent characterization with no presumption of exact signal morphology. As a test case, we generate mock gamma-ray data to demonstrate our ability to extract extended signals without assuming a fixed spatial template. For some point source luminosity functions, our technique also allows us to differentiate a diffuse signal in gamma-rays from dark matter annihilation and extended gamma-ray point source populations in a data-driven way.