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Sample records for employing scanner specific

  1. Why do commercial CT scanners still employ traditional, filtered back-projection for image reconstruction?

    International Nuclear Information System (INIS)

    Pan, Xiaochuan; Sidky, Emil Y; Vannier, Michael

    2009-01-01

    Despite major advances in x-ray sources, detector arrays, gantry mechanical design and especially computer performance, one component of computed tomography (CT) scanners has remained virtually constant for the past 25 years—the reconstruction algorithm. Fundamental advances have been made in the solution of inverse problems, especially tomographic reconstruction, but these works have not been translated into clinical and related practice. The reasons are not obvious and seldom discussed. This review seeks to examine the reasons for this discrepancy and provides recommendations on how it can be resolved. We take the example of field of compressive sensing (CS), summarizing this new area of research from the eyes of practical medical physicists and explaining the disconnection between theoretical and application-oriented research. Using a few issues specific to CT, which engineers have addressed in very specific ways, we try to distill the mathematical problem underlying each of these issues with the hope of demonstrating that there are interesting mathematical problems of general importance that can result from in depth analysis of specific issues. We then sketch some unconventional CT-imaging designs that have the potential to impact on CT applications, if the link between applied mathematicians and engineers/physicists were stronger. Finally, we close with some observations on how the link could be strengthened. There is, we believe, an important opportunity to rapidly improve the performance of CT and related tomographic imaging techniques by addressing these issues. (topical review)

  2. Quantitative wound healing studies using a portable, low cost, handheld near-infrared optical scanner: preliminary sensitivity and specificity analysis

    Science.gov (United States)

    Lei, Jiali; Rodriguez, Suset; Jayachandran, Maanasa; Solis, Elizabeth; Gonzalez, Stephanie; Perez-Clavijo, Francesco; Wigley, Stephen; Godavarty, Anuradha

    2016-03-01

    Lower extremity ulcers are devastating complications that are still un-recognized. To date, clinicians employ visual inspection of the wound site during its standard 4-week of healing process via monitoring of surface granulation. A novel ultra-portable near-infrared optical scanner (NIROS) has been developed at the Optical Imaging Laboratory that can perform non-contact 2D area imaging of the wound site. From preliminary studies it was observed that the nonhealing wounds had a greater absorption contrast with respect to the normal site, unlike in the healing wounds. Currently, non-contact near-infrared (NIR) imaging studies were carried out on 22 lower extremity wounds at two podiatric clinics, and the sensitivity and specificity of the scanner evaluated. A quantitative optical biometric was developed that differentiates healing from non-healing wounds, based on the threshold values obtained during ROC analysis. In addition, optical images of the wound obtained from weekly imaging studies are also assessed to determine the ability of the device to predict wound healing consistently on a periodic basis. This can potentially impact early intervention in the treatment of lower extremity ulcers when an objective and quantitative wound healing approach is developed. Lastly, the incorporation of MATLAB graphical user interface (GUI) to automate the process of image acquisition, image processing and image analysis realizes the potential of NIROS to perform non-contact and real-time imaging on lower extremity wounds.

  3. Development of Monte Carlo simulations to provide scanner-specific organ dose coefficients for contemporary CT

    Science.gov (United States)

    Jansen, Jan T. M.; Shrimpton, Paul C.

    2016-07-01

    The ImPACT (imaging performance assessment of CT scanners) CT patient dosimetry calculator is still used world-wide to estimate organ and effective doses (E) for computed tomography (CT) examinations, although the tool is based on Monte Carlo calculations reflecting practice in the early 1990’s. Subsequent developments in CT scanners, definitions of E, anthropomorphic phantoms, computers and radiation transport codes, have all fuelled an urgent need for updated organ dose conversion factors for contemporary CT. A new system for such simulations has been developed and satisfactorily tested. Benchmark comparisons of normalised organ doses presently derived for three old scanners (General Electric 9800, Philips Tomoscan LX and Siemens Somatom DRH) are within 5% of published values. Moreover, calculated normalised values of CT Dose Index for these scanners are in reasonable agreement (within measurement and computational uncertainties of  ±6% and  ±1%, respectively) with reported standard measurements. Organ dose coefficients calculated for a contemporary CT scanner (Siemens Somatom Sensation 16) demonstrate potential deviations by up to around 30% from the surrogate values presently assumed (through a scanner matching process) when using the ImPACT CT Dosimetry tool for newer scanners. Also, illustrative estimates of E for some typical examinations and a range of anthropomorphic phantoms demonstrate the significant differences (by some 10’s of percent) that can arise when changing from the previously adopted stylised mathematical phantom to the voxel phantoms presently recommended by the International Commission on Radiological Protection (ICRP), and when following the 2007 ICRP recommendations (updated from 1990) concerning tissue weighting factors. Further simulations with the validated dosimetry system will provide updated series of dose coefficients for a wide range of contemporary scanners.

  4. Two examples of indication specific radiation dose calculations in dental CBCT and Multidetector CT scanners.

    Science.gov (United States)

    Stratis, Andreas; Zhang, Guozhi; Lopez-Rendon, Xochitl; Politis, Constantinus; Hermans, Robert; Jacobs, Reinhilde; Bogaerts, Ria; Shaheen, Eman; Bosmans, Hilde

    2017-09-01

    To calculate organ doses and estimate the effective dose for justification purposes in patients undergoing orthognathic treatment planning purposes and temporal bone imaging in dental cone beam CT (CBCT) and Multidetector CT (MDCT) scanners. The radiation dose to the ICRP reference male voxel phantom was calculated for dedicated orthognathic treatment planning acquisitions via Monte Carlo simulations in two dental CBCT scanners, Promax 3D Max (Planmeca, FI) and NewTom VGi evo (QR s.r.l, IT) and in Somatom Definition Flash (Siemens, DE) MDCT scanner. For temporal bone imaging, radiation doses were calculated via MC simulations for a CBCT protocol in NewTom 5G (QR s.r.l, IT) and with the use of a software tool (CT-expo) for Somatom Force (Siemens, DE). All procedures had been optimized at the acceptance tests of the devices. For orthognathic protocols, dental CBCT scanners deliver lower doses compared to MDCT scanners. The estimated effective dose (ED) was 0.32mSv for a normal resolution operation mode in Promax 3D Max, 0.27mSv in VGi-evo and 1.18mSv in the Somatom Definition Flash. For temporal bone protocols, the Somatom Force resulted in an estimated ED of 0.28mSv while for NewTom 5G the ED was 0.31 and 0.22mSv for monolateral and bilateral imaging respectively. Two clinical exams which are carried out with both a CBCT or a MDCT scanner were compared in terms of radiation dose. Dental CBCT scanners deliver lower doses for orthognathic patients whereas for temporal bone procedures the doses were similar. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  5. Developing patient-specific dose protocols for a CT scanner and exam using diagnostic reference levels

    International Nuclear Information System (INIS)

    Strauss, Keith J.

    2014-01-01

    The management of image quality and radiation dose during pediatric CT scanning is dependent on how well one manages the radiographic techniques as a function of the type of exam, type of CT scanner, and patient size. The CT scanner's display of expected CT dose index volume (CTDI vol ) after the projection scan provides the operator with a powerful tool prior to the patient scan to identify and manage appropriate CT techniques, provided the department has established appropriate diagnostic reference levels (DRLs). This paper provides a step-by-step process that allows the development of DRLs as a function of type of exam, of actual patient size and of the individual radiation output of each CT scanner in a department. Abdomen, pelvis, thorax and head scans are addressed. Patient sizes from newborns to large adults are discussed. The method addresses every CT scanner regardless of vendor, model or vintage. We cover adjustments to techniques to manage the impact of iterative reconstruction and provide a method to handle all available voltages other than 120 kV. This level of management of CT techniques is necessary to properly monitor radiation dose and image quality during pediatric CT scans. (orig.)

  6. Cooperation and perception specifics of working students by employers

    Directory of Open Access Journals (Sweden)

    N. I. Fedorenko

    2015-01-01

    Full Text Available The article describes that competition for attractive working position is actively growing up between categories of employees which are different in age, experience and educational level. The severity of this competition is also increasing for the account of students. Further the author describes results of personal research regarding cooperation and perception specifics of working students with the relation to employers. The main trends of employers attitude toward working students are defined and described: interest in cooperation, underlying factors that redound to cooperation between employers and students, employers suggestions toward reasons that lead students to work, particularities in perception of students as employees by employers, job usually offered students by employers, concessions on the needs of students employers are ready to fit. The research presents items of formal relationships between employers and students. Respondent’s answers also allow to analyze particularities in perception of working students by employers and draw up hierarchy of positive and negative qualities of working students according to the viewpoint of employers. The conclusions of the article summarize particularities in perception and relationships between students and employers and indicate whether students are able to realize themselves in additional employment and to form necessary professional skills and abilities.

  7. Development of PC based Monte Carlo simulations for the calculation of scanner-specific normalized organ doses from CT

    International Nuclear Information System (INIS)

    Jansen, J. T. M.; Shrimpton, P. C.; Zankl, M.

    2009-01-01

    This paper discusses the simulation of contemporary computed tomography (CT) scanners using Monte Carlo calculation methods to derive normalized organ doses, which enable hospital physicists to estimate typical organ and effective doses for CT examinations. The hardware used in a small PC-cluster at the Health Protection Agency (HPA) for these calculations is described. Investigations concerning optimization of software, including the radiation transport codes MCNP5 and MCNPX, and the Intel and PGI FORTRAN compilers, are presented in relation to results and calculation speed. Differences in approach for modelling the X-ray source are described and their influences are analysed. Comparisons with previously published calculations at HPA from the early 1990's proved satisfactory for the purposes of quality assurance and are presented in terms of organ dose ratios for whole body exposure and differences in organ location. Influences on normalized effective dose are discussed in relation to choice of cross section library, CT scanner technology (contemporary multi slice versus single slice), definition for effective dose (1990 and 2007 versions) and anthropomorphic phantom (mathematical and voxel). The results illustrate the practical need for the updated scanner-specific dose coefficients presently being calculated at HPA, in order to facilitate improved dosimetry for contemporary CT practice. (authors)

  8. Locally specific measures for employment aimed at regional development

    Directory of Open Access Journals (Sweden)

    Vladimir Cini

    2013-12-01

    Full Text Available The oldest and largest sub-region in the world functioning on the principle of economic union is the European Union. The creation of a single market has initiated the process of conditional adjustment of markets in the EU member states, which has a significant impact on the social welfare of its citizens. It is necessary to tackle this issue by joint efforts within the European Union. As globalization processes push for economic integration and development of competitive advantage, the regions will have to make some challenging adjustments. The development tends to concentrate in highly competitive regions, while regions in the periphery lag behind. However, this pertains not only to the economic lag, but also to a potential negative political situation. Locally specific active employment policy measures are a continuation of the effort to make these measures more flexible. They refer to the Joint Assessment of Employment Policy Priorities and the IPA Human Resources Development Operational Programme - a regional policy instrument of the European Union. Both documents highlight the issue of disproportional development of regions, which requires special local measures and active labour market policy programmes. To reduce regional differences in development, it is necessary to invest more resources in the regions that lag behind. In this particular case, this means the counties in Croatia with high unemployment rates, a large number of registered unemployed persons and low employment rate. Consequently, this paper explains the importance of the adoption of locally specific measures for employment, which unfortunately did not take hold in the Republic of Croatia, and highlights the need for further decentralization of public services, with the aim of balancing regional development

  9. Periodic local MP2 method employing orbital specific virtuals

    International Nuclear Information System (INIS)

    Usvyat, Denis; Schütz, Martin; Maschio, Lorenzo

    2015-01-01

    We introduce orbital specific virtuals (OSVs) to represent the truncated pair-specific virtual space in periodic local Møller-Plesset perturbation theory of second order (LMP2). The OSVs are constructed by diagonalization of the LMP2 amplitude matrices which correspond to diagonal Wannier-function (WF) pairs. Only a subset of these OSVs is adopted for the subsequent OSV-LMP2 calculation, namely, those with largest contribution to the diagonal pair correlation energy and with the accumulated value of these contributions reaching a certain accuracy. The virtual space for a general (non diagonal) pair is spanned by the union of the two OSV sets related to the individual WFs of the pair. In the periodic LMP2 method, the diagonal LMP2 amplitude matrices needed for the construction of the OSVs are calculated in the basis of projected atomic orbitals (PAOs), employing very large PAO domains. It turns out that the OSVs are excellent to describe short range correlation, yet less appropriate for long range van der Waals correlation. In order to compensate for this bias towards short range correlation, we augment the virtual space spanned by the OSVs by the most diffuse PAOs of the corresponding minimal PAO domain. The Fock and overlap matrices in OSV basis are constructed in the reciprocal space. The 4-index electron repulsion integrals are calculated by local density fitting and, for distant pairs, via multipole approximation. New procedures for determining the fit-domains and the distant-pair lists, leading to higher efficiency in the 4-index integral evaluation, have been implemented. Generally, and in contrast to our previous PAO based periodic LMP2 method, the OSV-LMP2 method does not require anymore great care in the specification of the individual domains (to get a balanced description when calculating energy differences) and is in that sense a black box procedure. Discontinuities in potential energy surfaces, which may occur for PAO-based calculations if one is not

  10. Periodic local MP2 method employing orbital specific virtuals

    Energy Technology Data Exchange (ETDEWEB)

    Usvyat, Denis, E-mail: denis.usvyat@chemie.uni-regensburg.de; Schütz, Martin, E-mail: martin.schuetz@chemie.uni-regensburg.de [Institute for Physical and Theoretical Chemistry, Universität Regensburg, Universitätsstraße 31, D-93040 Regensburg (Germany); Maschio, Lorenzo, E-mail: lorenzo.maschio@unito.it [Dipartimento di Chimica, and Centre of Excellence NIS (Nanostructured Interfaces and Surfaces), Università di Torino, via Giuria 5, I-10125 Torino (Italy)

    2015-09-14

    We introduce orbital specific virtuals (OSVs) to represent the truncated pair-specific virtual space in periodic local Møller-Plesset perturbation theory of second order (LMP2). The OSVs are constructed by diagonalization of the LMP2 amplitude matrices which correspond to diagonal Wannier-function (WF) pairs. Only a subset of these OSVs is adopted for the subsequent OSV-LMP2 calculation, namely, those with largest contribution to the diagonal pair correlation energy and with the accumulated value of these contributions reaching a certain accuracy. The virtual space for a general (non diagonal) pair is spanned by the union of the two OSV sets related to the individual WFs of the pair. In the periodic LMP2 method, the diagonal LMP2 amplitude matrices needed for the construction of the OSVs are calculated in the basis of projected atomic orbitals (PAOs), employing very large PAO domains. It turns out that the OSVs are excellent to describe short range correlation, yet less appropriate for long range van der Waals correlation. In order to compensate for this bias towards short range correlation, we augment the virtual space spanned by the OSVs by the most diffuse PAOs of the corresponding minimal PAO domain. The Fock and overlap matrices in OSV basis are constructed in the reciprocal space. The 4-index electron repulsion integrals are calculated by local density fitting and, for distant pairs, via multipole approximation. New procedures for determining the fit-domains and the distant-pair lists, leading to higher efficiency in the 4-index integral evaluation, have been implemented. Generally, and in contrast to our previous PAO based periodic LMP2 method, the OSV-LMP2 method does not require anymore great care in the specification of the individual domains (to get a balanced description when calculating energy differences) and is in that sense a black box procedure. Discontinuities in potential energy surfaces, which may occur for PAO-based calculations if one is not

  11. Scintillation scanner

    International Nuclear Information System (INIS)

    Mehrbrodt, A.W.; Mog, W.F.; Brunnett, C.J.

    1977-01-01

    A scintillation scanner having a visual image producing means coupled through a lost motion connection to the boom which supports the scintillation detector is described. The lost motion connection is adjustable to compensate for such delays as may occur between sensing and recording scintillations. 13 claims, 5 figures

  12. NMR-CT scanner

    International Nuclear Information System (INIS)

    Kose, Katsumi; Sato, Kozo; Sugimoto, Hiroshi; Sato, Masataka.

    1983-01-01

    A brief explanation is made on the imaging methods for a practical diagnostic NMR-CT scanner : A whole-body NMR-CT scanner utilizing a resistive magnet has been developed by Toshiba in cooperation with the Institute for Solid State Physics, the University of Tokyo. Typical NMR-CT images of volunteers and patients obtained in the clinical experiments using this device are presented. Detailed specifications are also shown about the practical NMR-CTs which are to be put on the market after obtaining the government approval. (author)

  13. Gender-specific spatial interactions on Dutch regional labour markets and the gender employment gap

    NARCIS (Netherlands)

    Noback, Inge; Broersma, Lourens; Van Dijk, Jouke

    2013-01-01

    Gender-specific spatial interactions on Dutch regional labour markets and the gender employment gap, Regional Studies. This paper analyses gender-specific employment rates and the gender employment gap in Dutch municipalities for 2002. The novelty of this analysis is that it takes into account the

  14. 25 CFR 170.913 - Do tribal-specific employment rights and contract preference laws apply?

    Science.gov (United States)

    2010-04-01

    ... Indian Preference § 170.913 Do tribal-specific employment rights and contract preference laws apply? Yes... tribe within the consortium, the benefitting tribe's employment rights and contracting preference laws... 25 Indians 1 2010-04-01 2010-04-01 false Do tribal-specific employment rights and contract...

  15. Robotic Prostate Biopsy in Closed MRI Scanner

    National Research Council Canada - National Science Library

    Fischer, Gregory

    2008-01-01

    .... This work enables prostate brachytherapy and biopsy procedures in standard high-field diagnostic MRI scanners through the development of a robotic needle placement device specifically designed...

  16. College Students' Views of the Specific Costs and Benefits Associated with Maternal Employment.

    Science.gov (United States)

    Fronheiser, April; DiBlasi, Francis Paul; Brogan, Maureen; Kosakowski, Jill; Hess, Auden; Alleger, Lindsay; Sosnowski, Jane; Sternberg, Tamar; Chambliss, Catherine

    This study investigated college students' perceptions of the specific costs and benefits to children associated with maternal employment outside the home. Respondents were grouped on the basis of their own mothers' maternal employment status. Attitudes about psychological, academic, behavioral, and environmental risks associated with maternal…

  17. Young Adults' Perceptions of the Specific Costs and Benefits Associated with Maternal Employment.

    Science.gov (United States)

    Fleming, Hillary; Farrell, Debi; Fronheiser, April; DiBlasi, Paul; Fields, Susan; Eddy, Preethy; Denis, Lauren; Hemperly, Megan; Strauss, Aviva; Maggi, Leigh; Chambliss, Catherine

    This study investigated the influence of maternal employment on perceptions of the specific costs and benefits to children associated with mothers working outside the home and professional ambition among young adults. A sample of 90 college students completed a survey including the Beliefs About the Consequences of Maternal Employment for Children…

  18. Postschool Educational and Employment Experiences of Young People with Specific Language Impairment

    Science.gov (United States)

    Conti-Ramsden, Gina; Durkin, Kevin

    2012-01-01

    Purpose: This study examined the postschool educational and employment experiences of young people with and without specific language impairment (SLI). Method: Nineteen-year-olds with (n = 50) and without (n = 50) SLI were interviewed on their education and employment experiences since finishing compulsory secondary education. Results: On average,…

  19. Challenges for Youth Employment in Pakistan : Are They Youth-Specific?

    OpenAIRE

    Hou, Xiaohui

    2011-01-01

    This paper analyzes the patterns of and the challenges for youth employment in Pakistan and examines whether these challenges are youth-specific. Using the 2005/2006 Labor Force Survey, the analysis includes determinants of unemployment, determinants of working in the formal sector, rate of return on education, and determinants of working hours. The paper finds that many of the challenges ...

  20. Wire Scanner Motion Control Card

    CERN Document Server

    Forde, S E

    2006-01-01

    Scientists require a certain beam quality produced by the accelerator rings at CERN. The discovery potential of LHC is given by the reachable luminosity at its interaction points. The luminosity is maximized by minimizing the beam size. Therefore an accurate beam size measurement is required for optimizing the luminosity. The wire scanner performs very accurate profile measurements, but as it can not be used at full intensity in the LHC ring, it is used for calibrating other profile monitors. As the current wire scanner system, which is used in the present CERN accelerators, has not been made for the required specification of the LHC, a new design of a wire scanner motion control card is part of the LHC wire scanner project. The main functions of this card are to control the wire scanner motion and to acquire the position of the wire. In case of further upgrades at a later stage, it is required to allow an easy update of the firmware, hence the programmable features of FPGAs will be used for this purpose. The...

  1. Vocational education and employment over the life course using a new measure of occupational specificity.

    Science.gov (United States)

    Forster, Andrea G; Bol, Thijs

    2018-02-01

    Vocational education is seen as beneficial for the labor market allocation of young people. However, recent studies point to disadvantages later in the life course, where the specific skills that are obtained from vocational education decrease employability. This paper re-evaluates this hypothesis for the Netherlands with an improved measure for the vocational specificity of educational programs, utilizing both vertical (level) and horizontal (field) information on education. More specifically, we use a gradual measure for the linkage strength between education and occupation to predict employment over the life course. Using data from the national Dutch labor force surveys, we show that there is considerable heterogeneity in occupational specificity within the categories of vocational and general educational programs that is masked when using a dichotomous classification of general versus vocational education. In the life course analyses we find that the large early benefits of having vocational education disappear later in the career and turn into a small disadvantage before retirement. Copyright © 2017. Published by Elsevier Inc.

  2. Radiation dosimetry of computed tomography x-ray scanners

    International Nuclear Information System (INIS)

    Poletti, J.L.; Williamson, B.D.P.; Le Heron, J.C.

    1983-01-01

    This report describes the development and application of the methods employed in National Radiation Laboratory (NRL) surveys of computed tomography x-ray scanners (CT scanners). It includes descriptions of the phantoms and equipment used, discussion of the various dose parameters measured, the principles of the various dosimetry systems employed and some indication of the doses to occupationally exposed personnel

  3. Generation-specific incentives and disincentives for nurse faculty to remain employed.

    Science.gov (United States)

    Tourangeau, Ann E; Wong, Matthew; Saari, Margaret; Patterson, Erin

    2015-05-01

    The aims of this paper are to: (1) describe work characteristics that nurse faculty report encourage them to remain in or leave their academic positions; and (2) determine if there are generational differences in work characteristics selected. Nurse faculty play key roles in preparing new nurses and graduate nurses. However, educational institutions are challenged to maintain full employment in faculty positions. A cross-sectional, descriptive survey design was employed. Ontario nurse faculty were asked to select, from a list, work characteristics that entice them to remain in or leave their faculty positions. Respondent data (n = 650) were collected using mailed surveys over four months in 2011. While preferred work characteristics differed across generations, the most frequently selected incentives enticing nurse faculty to stay were having: a supportive director/dean, reasonable workloads, supportive colleagues, adequate resources, manageable class sizes and work/life balance. The most frequently selected disincentives included: unmanageable workloads, unsupportive organizations, poor work environments, exposure to bullying, belittling and other types of incivility in the workplace and having an unsupportive director/dean. This research yields new and important knowledge about work characteristics that nurse faculty report shape their decisions to remain in or leave their current employment. Certain work characteristics were rated as important among all generations. Where similarities exist, broad strategies addressing work characteristics may effectively promote nurse faculty retention. However, where generational differences exist, retention-promoting strategies should target generation-specific preferences. © 2014 John Wiley & Sons Ltd.

  4. Twisting wire scanner

    Energy Technology Data Exchange (ETDEWEB)

    Gharibyan, V.; Delfs, A.; Koruptchenkov, I.; Noelle, D.; Tiessen, H.; Werner, M.; Wittenburg, K.

    2012-11-15

    A new type of 'two-in-one' wire scanner is proposed. Recent advances in linear motors' technology make it possible to combine translational and rotational movements. This will allow to scan the beam in two perpendicular directions using a single driving motor and a special fork attached to it. Vertical or horizontal mounting will help to escape problems associated with the 45 deg scanners. Test results of the translational part with linear motors is presented.

  5. Twisting wire scanner

    International Nuclear Information System (INIS)

    Gharibyan, V.; Delfs, A.; Koruptchenkov, I.; Noelle, D.; Tiessen, H.; Werner, M.; Wittenburg, K.

    2012-11-01

    A new type of 'two-in-one' wire scanner is proposed. Recent advances in linear motors' technology make it possible to combine translational and rotational movements. This will allow to scan the beam in two perpendicular directions using a single driving motor and a special fork attached to it. Vertical or horizontal mounting will help to escape problems associated with the 45 deg scanners. Test results of the translational part with linear motors is presented.

  6. Scanners for analytic print measurement: the devil in the details

    Science.gov (United States)

    Zeise, Eric K.; Williams, Don; Burns, Peter D.; Kress, William C.

    2007-01-01

    Inexpensive and easy-to-use linear and area-array scanners have frequently substituted as colorimeters and densitometers for low-frequency (i.e., large area) hard copy image measurement. Increasingly, scanners are also being used for high spatial frequency, image microstructure measurements, which were previously reserved for high performance microdensitometers. In this paper we address characteristics of flatbed reflection scanners in the evaluation of print uniformity, geometric distortion, geometric repeatability and the influence of scanner MTF and noise on analytic measurements. Suggestions are made for the specification and evaluation of scanners to be used in print image quality standards that are being developed.

  7. Coastal Zone Color Scanner studies

    Science.gov (United States)

    Elrod, J.

    1988-01-01

    Activities over the past year have included cooperative work with a summer faculty fellow using the Coastal Zone Color Scanner (CZCS) imagery to study the effects of gradients in trophic resources on coral reefs in the Caribbean. Other research included characterization of ocean radiances specific to an acid-waste plume. Other activities include involvement in the quality control of imagery produced in the processing of the global CZCS data set, the collection of various other data global sets, and the subsequent data comparison and analysis.

  8. MEMS temperature scanner: principles, advances, and applications

    Science.gov (United States)

    Otto, Thomas; Saupe, Ray; Stock, Volker; Gessner, Thomas

    2010-02-01

    Contactless measurement of temperatures has gained enormous significance in many application fields, ranging from climate protection over quality control to object recognition in public places or military objects. Thereby measurement of linear or spatially temperature distribution is often necessary. For this purposes mostly thermographic cameras or motor driven temperature scanners are used today. Both are relatively expensive and the motor drive devices are limited regarding to the scanning rate additionally. An economic alternative are temperature scanner devices based on micro mirrors. The micro mirror, attached in a simple optical setup, reflects the emitted radiation from the observed heat onto an adapted detector. A line scan of the target object is obtained by periodic deflection of the micro scanner. Planar temperature distribution will be achieved by perpendicularly moving the target object or the scanner device. Using Planck radiation law the temperature of the object is calculated. The device can be adapted to different temperature ranges and resolution by using different detectors - cooled or uncooled - and parameterized scanner parameters. With the basic configuration 40 spatially distributed measuring points can be determined with temperatures in a range from 350°C - 1000°C. The achieved miniaturization of such scanners permits the employment in complex plants with high building density or in direct proximity to the measuring point. The price advantage enables a lot of applications, especially new application in the low-price market segment This paper shows principle, setup and application of a temperature measurement system based on micro scanners working in the near infrared range. Packaging issues and measurement results will be discussed as well.

  9. Married Parents' Perceptions of the Specific Costs and Benefits Associated with Maternal Employment.

    Science.gov (United States)

    DiBlasi, Francis Paul; Fronheiser, April; Baker, Kathleen; Fontanez, Mary; Fulmer, Kim; Ryckebusch, Jenna; Ellis, Trisha; Miller, Heather; Carey, Brandi; Gorton, Laura; Chambliss, Catherine

    This investigation explored parents' attitudes about the risks and benefits associated with maternal employment. The responses of husbands and wives from single paycheck versus dual paycheck families were compared. Participants in this study were 109 mothers and 96 fathers given a survey assessing their views on maternal employment. This study…

  10. Ionization beam scanner

    CERN Multimedia

    CERN PhotoLab

    1973-01-01

    Inner structure of an ionization beam scanner, a rather intricate piece of apparatus which permits one to measure the density distribution of the proton beam passing through it. On the outside of the tank wall there is the coil for the longitudinal magnetic field, on the inside, one can see the arrangement of electrodes creating a highly homogeneous transverse electric field.

  11. Scanner calibration revisited

    Directory of Open Access Journals (Sweden)

    Pozhitkov Alexander E

    2010-07-01

    Full Text Available Abstract Background Calibration of a microarray scanner is critical for accurate interpretation of microarray results. Shi et al. (BMC Bioinformatics, 2005, 6, Art. No. S11 Suppl. 2. reported usage of a Full Moon BioSystems slide for calibration. Inspired by the Shi et al. work, we have calibrated microarray scanners in our previous research. We were puzzled however, that most of the signal intensities from a biological sample fell below the sensitivity threshold level determined by the calibration slide. This conundrum led us to re-investigate the quality of calibration provided by the Full Moon BioSystems slide as well as the accuracy of the analysis performed by Shi et al. Methods Signal intensities were recorded on three different microarray scanners at various photomultiplier gain levels using the same calibration slide from Full Moon BioSystems. Data analysis was conducted on raw signal intensities without normalization or transformation of any kind. Weighted least-squares method was used to fit the data. Results We found that initial analysis performed by Shi et al. did not take into account autofluorescence of the Full Moon BioSystems slide, which led to a grossly distorted microarray scanner response. Our analysis revealed that a power-law function, which is explicitly accounting for the slide autofluorescence, perfectly described a relationship between signal intensities and fluorophore quantities. Conclusions Microarray scanners respond in a much less distorted fashion than was reported by Shi et al. Full Moon BioSystems calibration slides are inadequate for performing calibration. We recommend against using these slides.

  12. Gamma scanner conceptual design report

    International Nuclear Information System (INIS)

    Swinth, K.L.

    1979-11-01

    The Fuels and Materials Examination Facility (FMEF) will include several stations for the nondestructive examination of irradiated fuels. One of these stations will be the gamma scanner which will be employed to detect gamma radiation from the irradiated fuel pins. The conceptual design of the gamma scan station is described. The gamma scanner will use a Standard Exam Stage (SES) as a positioner and transport mechanism for the fuel pins which it will obtain from a magazine. A pin guide mechanism mounted on the face of the collimator will assure that the fuel pins remain in front of the collimator during scanning. The collimator has remotely adjustable tungsten slits and can be manually rotated to align the slit at various angles. A shielded detector cart located in the operating corridor holds an intrinsic germanium detector and associated sodium-iodide anticoincidence detector. The electronics associated with the counting system consist of standard NIM modules to process the detector signals and a stand-alone multichannel analyzer (MCA) for counting data accumulation. Data from the MCA are bussed to the station computer for analysis and storage on magnetic tape. The station computer controls the collimator, the MCA, a source positioner and the SES through CAMAC-based interface hardware. Most of the electronic hardware is commercially available but some interfaces will require development. Conceptual drawings are included for mechanical hardware that must be designed and fabricated

  13. Scanner OPC signatures: automatic vendor-to-vendor OPE matching

    Science.gov (United States)

    Renwick, Stephen P.

    2009-03-01

    As 193nm lithography continues to be stretched and the k1 factor decreases, optical proximity correction (OPC) has become a vital part of the lithographer's tool kit. Unfortunately, as is now well known, the design variations of lithographic scanners from different vendors cause them to have slightly different optical-proximity effect (OPE) behavior, meaning that they print features through pitch in distinct ways. This in turn means that their response to OPC is not the same, and that an OPC solution designed for a scanner from Company 1 may or may not work properly on a scanner from Company 2. Since OPC is not inexpensive, that causes trouble for chipmakers using more than one brand of scanner. Clearly a scanner-matching procedure is needed to meet this challenge. Previously, automatic matching has only been reported for scanners of different tool generations from the same manufacturer. In contrast, scanners from different companies have been matched using expert tuning and adjustment techniques, frequently requiring laborious test exposures. Automatic matching between scanners from Company 1 and Company 2 has remained an unsettled problem. We have recently solved this problem and introduce a novel method to perform the automatic matching. The success in meeting this challenge required three enabling factors. First, we recognized the strongest drivers of OPE mismatch and are thereby able to reduce the information needed about a tool from another supplier to that information readily available from all modern scanners. Second, we developed a means of reliably identifying the scanners' optical signatures, minimizing dependence on process parameters that can cloud the issue. Third, we carefully employed standard statistical techniques, checking for robustness of the algorithms used and maximizing efficiency. The result is an automatic software system that can predict an OPC matching solution for scanners from different suppliers without requiring expert intervention.

  14. 26 CFR 31.3121(b)(5)-1 - Services in employ of an instrumentality of the United States specifically exempted from the...

    Science.gov (United States)

    2010-04-01

    ... Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) EMPLOYMENT TAXES AND... employ of an instrumentality of the United States specifically exempted from the employer tax. Services... 26 Internal Revenue 15 2010-04-01 2010-04-01 false Services in employ of an instrumentality of the...

  15. "The General Theory of Employment, Interest and Money" J. M. Keynes: Background, Methodology and Specific Interpretations

    Directory of Open Access Journals (Sweden)

    Nureev Rustem, M.

    2016-03-01

    Full Text Available The paper was prepared for the 80-th anniversary of publishing of John Maynard Keynes’ “General Theory of Employment, Interest and Money”. It discusses the stages of the economist’s life, the main books written prior to "The General Theory ...". Particular attention is devoted to the development issues of the monetary policy in the works of "Indian Currency and Finance", ”A Tract on Monetary Reform” and "A Treatise on Money". A special section is dedicated to the analysis of Keynes’ methodology, its logic and structure, influenced by John. E. Moore. The paper reveals the unity and the difference in approaches of A. Marshall and John M. Keynes, and explores new categories of behavioral economics and marginal analysis, which established the success of "General Theory of Employment, Interest and Money", shows the value of Keynes's theory for the further development of macroeconomics. Particular attention is paid to the popularization of Keynes's ideas from the initial interpretations of "The General Theory ..." to the neoclassical synthesis and further to neo-Keynesianism and post-Keynesianism. The paper studies the unity and the distinction between Hicks’ and American Keynesianism. Hicksian assumptions of a savings-investment function have determined the features of the IS-LM model. The contributions to the development of Keynesianism A. Hansen and P. A. Samuelson are also shown, as well as the history of the "Keynesian Cross". A comparative analysis of the neoclassical and Keynesian models of general economic equilibrium is given and analyzes the institutional reasons explaining differences between neoclassical and Keynesian paradigms. A special section is devoted to the Keynesian theory of growth, showing unity and difference of R. Harrod and E. Domar models, along with their impact on the creation of Development Economics. Simplified understanding of Keynes's legacy has caused the emergence of unorthodox Keynesianism. The paper

  16. Generic versus specific competencies of entry-level public health graduates: employers' perceptions in Poland, the UK, and the Netherlands.

    Science.gov (United States)

    Biesma, Regien G; Pavlova, Milena; Vaatstra, Rina; van Merode, Godefridus G; Czabanowska, Katarzyna; Smith, Tony; Groot, Wim

    2008-08-01

    Constant changes in society and the public health domain force public health professionals into new roles and the development of new competencies. Public health professionals will need to be trained to respond to this challenge. The aim of this comparative study among Poland, the UK and the Netherlands is to identify competence needs for Master of Public Health graduates entering the labour market from a European perspective. A self-administered questionnaire was sent to employers in the three countries, rating the importance of competency in public health on a master's level. In all three countries, interpersonal competencies, like team working and communication skills, are rated as highly important. However, employers in the UK and Poland generally rate public health specific competencies as much more important than their Dutch colleagues. It is concluded that while public health specific knowledge is providing a useful starting point for entry-level public health professionals, employers increasingly recognise the value of generic competencies such as communication and team working skills. The results suggest a stronger emphasis on teaching methods that encourage active learning and the integration of skills, which is crucial for enhancing graduates' employability, and foster an open attitude to multidisciplinary working, which is essential in modern health care.

  17. Evaluation of Handheld Scanners for Automotive Applications

    Directory of Open Access Journals (Sweden)

    Wadea Ameen

    2018-01-01

    Full Text Available The process of generating a computerized geometric model for an existing part is known as Reverse Engineering (RE. It is a very useful technique in product development and plays a significant role in automotive, aerospace, and medical industries. In fact, it has been getting remarkable attention in manufacturing industries owing to its advanced data acquisition technologies. The process of RE is based on two primary steps: data acquisition (also known as scanning and data processing. To facilitate point data acquisition, a variety of scanning systems is available with different capabilities and limitations. Although the optical control of 3D scanners is fully developed, still several factors can affect the quality of the scanned data. As a result, the proper selection of scanning parameters, such as resolution, laser power, shutter time, etc., becomes very crucial. This kind of investigation can be very helpful and provide its users with guidelines to identify the appropriate factors. Moreover, it is worth noting that no single system is ideal in all applications. Accordingly, this work has compared two portable (handheld systems based on laser scanning and white light optical scanning for automotive applications. A car door containing a free-form surface has been used to achieve the above-mentioned goal. The design of experiments has been employed to determine the effects of different scanning parameters and optimize them. The capabilities and limitations have been identified by comparing the two scanners in terms of accuracy, scanning time, triangle numbers, ease of use, and portability. Then, the relationships between the system capabilities and the application requirements have been established. The results revealed that the laser scanner performed better than the white light scanner in terms of accuracy, while the white light scanner performed better in terms of acquisition speed and triangle numbers.

  18. Whole body line scanner

    International Nuclear Information System (INIS)

    Berninger, W.H.

    1975-01-01

    A bar-shaped scintillator converts incident collimated gamma rays to light pulses which are detected by a row of photoelectric tubes positioned along the output face of the scintillator wherein each tube has a convexly curved photocathode disposed in close proximity to the scintillator. Electronic circuitry connected to the output of phototubes develops the scintillation event x-axis position coordinate electrical signal with good linearity and with substantial independence of the spacing between the scintillator and photocathodes so that the phototubes can be positioned as close to the scintillator as possible to obtain reduced distortion in the field of view and improved spatial resolution. A mechanical drive of the scanner results in an image of the gamma ray source being formed by sequencing the developed scintillation position coordinate signals in the y-axis dimension

  19. Coastal Zone Color Scanner

    Science.gov (United States)

    Johnson, B.

    1988-01-01

    The Coastal Zone Color Scanner (CZCS) spacecraft ocean color instrument is capable of measuring and mapping global ocean surface chlorophyll concentration. It is a scanning radiometer with multiband capability. With new electronics and some mechanical, and optical re-work, it probably can be made flight worthy. Some additional components of a second flight model are also available. An engineering study and further tests are necessary to determine exactly what effort is required to properly prepare the instrument for spaceflight and the nature of interfaces to prospective spacecraft. The CZCS provides operational instrument capability for monitoring of ocean productivity and currents. It could be a simple, low cost alternative to developing new instruments for ocean color imaging. Researchers have determined that with global ocean color data they can: specify quantitatively the role of oceans in the global carbon cycle and other major biogeochemical cycles; determine the magnitude and variability of annual primary production by marine phytoplankton on a global scale; understand the fate of fluvial nutrients and their possible affect on carbon budgets; elucidate the coupling mechanism between upwelling and large scale patterns in ocean basins; answer questions concerning the large scale distribution and timing of spring blooms in the global ocean; acquire a better understanding of the processes associated with mixing along the edge of eddies, coastal currents, western boundary currents, etc., and acquire global data on marine optical properties.

  20. Radiographic scanner apparatus

    International Nuclear Information System (INIS)

    Wake, R.H.

    1980-01-01

    The preferred embodiment of this invention includes a hardware system, or processing means, which operates faster than software. Moreover the computer needed is less expensive and smaller. Radiographic scanner apparatus is described for measuring the intensity of radiation after passage through a planar region and for reconstructing a representation of the attenuation of radiation by the medium. There is a source which can be rotated, and detectors, the output from which forms a data line. The detectors are disposed opposite the planar region from the source to produce a succession of data lines corresponding to the succession of angular orientations of the source. There is a convolver means for convolving each of these data lines, with a filter function, and a means of processing the convolved data lines to create the representation of the radiation attenuation in the planar region. There is also apparatus to generate a succession of data lines indicating radiation attenuation along a determinable path with convolver means. (U.K.)

  1. The cobalt-60 container scanner

    International Nuclear Information System (INIS)

    Jigang, A.; Liye, Z.; Yisi, L.; Haifeng, W.; Zhifang, W.; Liqiang, W.; Yuanshi, Z.; Xincheng, X.; Furong, L.; Baozeng, G.; Chunfa, S.

    1997-01-01

    The Institute of Nuclear Energy Technology (INET) has successfully designed and constructed a container (cargo) scanner, which uses cobalt-60 of 100-300 Ci as radiation source. The following performances of the Cobalt-60 container scanner have been achieved at INET: a) IQI (Image Quality Indicator) - 2.5% behind 100 mm of steel; b) CI (Contrast Indicator) - 0.7% behind 100 mm of steel; c) SP (Steel Penetration) - 240 mm of steel; d) Maximum Dose per Scanning - 0.02mGy; e) Throughput - twenty 40-foot containers per hour. These performances are equal or similar to those of the accelerator scanners. Besides these nice enough inspection properties, the Cobalt-60 scanner possesses many other special features which are better than accelerator scanners: a) cheap price - it will be only or two tenths of the accelerator scanner's; b) low radiation intensity - the radiation protection problem is much easier to solve and a lot of money can be saved on the radiation shielding building; c) much smaller area for installation and operation; d) simple operation and convenient maintenance; e) high reliability and stability. The Cobalt-60 container (or cargo) scanner is satisfied for boundary customs, seaports, airports and railway stations etc. Because of the nice special features said above, it is more suitable to be applied widely. Its high properties and low price will make it have much better application prospects

  2. Side scanner for supermarkets: a new scanner design standard

    Science.gov (United States)

    Cheng, Charles K.; Cheng, J. K.

    1996-09-01

    High speed UPC bar code has become a standard mode of data capture for supermarkets in the US, Europe, and Japan. The influence of the ergonomics community on the design of the scanner is evident. During the past decade the ergonomic issues of cashier in check-outs has led to occupational hand-wrist cumulative trauma disorders, in most cases causing carpal tunnel syndrome, a permanent hand injury. In this paper, the design of a side scanner to resolve the issues is discussed. The complex optical module and the sensor for aforesaid side scanner is described. The ergonomic advantages offer the old counter mounted vertical scanner has been experimentally proved by the industrial funded study at an independent university.

  3. Requirements of Employers for Young Specialists and Issues of Their Training at the Educational Institutions: Regional Specificity of Moscow

    Directory of Open Access Journals (Sweden)

    Vyacheslav Nikolaevich Bobkov

    2016-12-01

    Full Text Available The subject-matter of the article is the study of the peculiarities of the youth labour market in such a specific region of Russia as the city of Moscow. The topic of the work is connected to the adaptation of young specialists training system to the regional requirements of the employers of Moscow. The main hypothesis of the research assumes that Moscow is the atypical region of Russia and it is inexpedient to apply criteria and methodological approaches, which are standard for our country, to its labour market. As a method of the research, a selective survey of key employers of Moscow and respondents aged from 14 till 30 years has been used. The data of the sociological survey conducted by the authors have allowed to establish the following features of the researched region: a respectively low level of youth unemployment compared with the whole Russia; focusing of employers on such features of personnel as a good communicative skills learning ability, professional knowledge and competences. Moscow employers don’t pay significant attention to such characteristics of young specialists as language and computer skills, computer knowledge and the diploma of a prestigious educational institution. The main difficulties in finding employment for young specialists in the city of Moscow are: overestimated salary expectations; the weak professional training level and unwillingness, in fact, to work. As a result of the survey, the practical offers have been formulated. There are two directions of their application: the offers focused on the behaviour of the youth at a stage of their training and those offers focused on the increase of a practical component of the activity of professional educational institutions. The authors came to conclusions about the need of a deep orientation of educational institutions to the applied training for specialists, of practical workers for teaching special disciplines, the development by future specialists their

  4. Nogle muligheder i scanner data

    DEFF Research Database (Denmark)

    Juhl, Hans Jørn

    2000-01-01

    I artiklen gives en diskussion af en række af de muligheder for effektivisering af marketingaktiviteter, der er til stede for såvel mærkevareudbyder som detaillist, ved udnyttelse af information fra scanner data......I artiklen gives en diskussion af en række af de muligheder for effektivisering af marketingaktiviteter, der er til stede for såvel mærkevareudbyder som detaillist, ved udnyttelse af information fra scanner data...

  5. Comparison of Epson scanner quality for radiochromic film evaluation.

    Science.gov (United States)

    Alnawaf, Hani; Yu, Peter K N; Butson, Martin

    2012-09-06

    Epson Desktop scanners have been quoted as devices which match the characteristics required for the evaluation of radiation dose exposure by radiochromic films. Specifically, models such as the 10000XL have been used successfully for image analysis and are recommended by ISP for dosimetry purposes. This note investigates and compares the scanner characteristics of three Epson desktop scanner models including the Epson 10000XL, V700, and V330. Both of the latter are substantially cheaper models capable of A4 scanning. As the price variation between the V330 and the 10000XL is 20-fold (based on Australian recommended retail price), cost savings by using the cheaper scanners may be warranted based on results. By a direct comparison of scanner uniformity and reproducibility we can evaluate the accuracy of these scanners for radiochromic film dosimetry. Results have shown that all three scanners can produce adequate scanner uniformity and reproducibility, with the inexpensive V330 producing a standard deviation variation across its landscape direction of 0.7% and 1.2% in the portrait direction (reflection mode). This is compared to the V700 in reflection mode of 0.25% and 0.5% for landscape and portrait directions, respectively, and 0.5% and 0.8% for the 10000XL. In transmission mode, the V700 is comparable in reproducibility to the 10000XL for portrait and landscape mode, whilst the V330 is only capable of scanning in the landscape direction and produces a standard deviation in this direction of 1.0% compared to 0.6% (V700) and 0.25% (10000XL). Results have shown that the V700 and 10000XL are comparable scanners in quality and accuracy with the 10000XL obviously capable of imaging over an A3 area as opposed to an A4 area for the V700. The V330 scanner produced slightly lower accuracy and quality with uncertainties approximately twice as much as the other scanners. However, the results show that the V330 is still an adequate scanner and could be used for radiation

  6. Laser scanner 3D terrestri e mobile

    Directory of Open Access Journals (Sweden)

    Mario Ciamba

    2013-08-01

    Full Text Available Recentemente si è svolto a Roma un evento dimostrativo per informare, professionisti e ricercatori del settore inerente il rilievo strumentale, sulle recenti innovazioni che riguardano i laser scanner 3d. Il mercato della strumentazione dedicata al rilevamento architettonico e dell'ambiente, offre molte possibilità di scelta. Oggi i principali marchi producono strumenti sempre più efficienti ed ideati per ambiti di applicazione specifici, permettendo ai professionisti, la giusta scelta in termini di prestazioni ed economia. A demonstration event was recently held in Rome with the aim to inform professionals and researchers on recent innovations on instrumental survey related to the 3d laser scanner. The market of instrumentation for architectural survey offers many possibilitiesof choice. Today the major brands produce instruments that are more efficient and designed for specific areas of application, allowing the right choice in terms of performance and economy.

  7. Laser scanner 3D terrestri e mobile

    Directory of Open Access Journals (Sweden)

    Mario Ciamba

    2013-08-01

    Full Text Available Recentemente si è svolto a Roma un evento dimostrativo per informare, professionisti e ricercatori del settore inerente il rilievo strumentale, sulle recenti innovazioni che riguardano i laser scanner 3d. Il mercato della strumentazione dedicata al rilevamento architettonico e dell'ambiente, offre molte possibilità di scelta. Oggi i principali marchi producono strumenti sempre più efficienti ed ideati per ambiti di applicazione specifici, permettendo ai professionisti, la giusta scelta in termini di prestazioni ed economia.A demonstration event was recently held in Rome with the aim to inform professionals and researchers on recent innovations on instrumental survey related to the 3d laser scanner. The market of instrumentation for architectural survey offers many possibilitiesof choice. Today the major brands produce instruments that are more efficient and designed for specific areas of application, allowing the right choice in terms of performance and economy.

  8. On the age-specific correlation between fertility and female employment: Heterogeneity over space and time in OECD countries

    Directory of Open Access Journals (Sweden)

    Uta Brehm

    2015-03-01

    Full Text Available Background: Though there has been profound research on the curious change in correlation between total fertility rate (TFR and female labor force participation (FLP in the mid-1980s, aspects of the compositional character of age-specific effects and the nature of countries' heterogeneity have been neglected. Objective: The present paper aims to contribute to filling this gap by analyzing annual total fertility rates and their equivalents for four age groups between 20 and 39 years as well as the respective lagged FLP from 17 OECD countries between 1985 and 2010. Methods: Random Intercept and Random Coefficient Models are applied, allowing us to assess both effects and country heterogeneity in slopes and intercepts. Results: The analyses reveal that the development of the correlation between FLP and TFR after 1985 is comprised of very different relations between age-specific fertility and labor participation. The youngest group's situation is determined by a decrease in both fertility and FLP, while countries' effects differ increasingly. The oldest women's fertility decisions seem to be detached from labor market influences, though country variation is high. Women in their late 20s and early 30s, in contrast, appear to be most affected by the incompatibility of childbearing and gainful employment. Though these effects seem to have overcome their low points during the mid-1990s, only women in their early 30s show country-convergence. Conclusions: The results highlight the fact that total and age-specific fertility behavior, FLP-effects and country variances are distinct concepts that add considerably to the broad understanding of the correlation between fertility and FLP.

  9. Radiographic scanners and shutter mechanisms in CT scanners

    International Nuclear Information System (INIS)

    Braden, A.B.; Kuwik, J.J.; Taylor, S.K.; Covic, J.

    1981-01-01

    This patent claim relates especially to the design of a shutter mechanism in a CT scanner having a rotatable source of radiation and a series of stationary radiation detectors coplanar with the path of the source and spaced about the axis of rotation of the source, and only partially encircling the path of the source. (U.K.)

  10. Methods for CT automatic exposure control protocol translation between scanner platforms.

    Science.gov (United States)

    McKenney, Sarah E; Seibert, J Anthony; Lamba, Ramit; Boone, John M

    2014-03-01

    An imaging facility with a diverse fleet of CT scanners faces considerable challenges when propagating CT protocols with consistent image quality and patient dose across scanner makes and models. Although some protocol parameters can comfortably remain constant among scanners (eg, tube voltage, gantry rotation time), the automatic exposure control (AEC) parameter, which selects the overall mA level during tube current modulation, is difficult to match among scanners, especially from different CT manufacturers. Objective methods for converting tube current modulation protocols among CT scanners were developed. Three CT scanners were investigated, a GE LightSpeed 16 scanner, a GE VCT scanner, and a Siemens Definition AS+ scanner. Translation of the AEC parameters such as noise index and quality reference mAs across CT scanners was specifically investigated. A variable-diameter poly(methyl methacrylate) phantom was imaged on the 3 scanners using a range of AEC parameters for each scanner. The phantom consisted of 5 cylindrical sections with diameters of 13, 16, 20, 25, and 32 cm. The protocol translation scheme was based on matching either the volumetric CT dose index or image noise (in Hounsfield units) between two different CT scanners. A series of analytic fit functions, corresponding to different patient sizes (phantom diameters), were developed from the measured CT data. These functions relate the AEC metric of the reference scanner, the GE LightSpeed 16 in this case, to the AEC metric of a secondary scanner. When translating protocols between different models of CT scanners (from the GE LightSpeed 16 reference scanner to the GE VCT system), the translation functions were linear. However, a power-law function was necessary to convert the AEC functions of the GE LightSpeed 16 reference scanner to the Siemens Definition AS+ secondary scanner, because of differences in the AEC functionality designed by these two companies. Protocol translation on the basis of

  11. Autism and Overcoming Job Barriers: Comparing Job-Related Barriers and Possible Solutions in and outside of Autism-Specific Employment.

    Directory of Open Access Journals (Sweden)

    Timo Lorenz

    Full Text Available The aim of this study was to discover how individuals with autism succeed in entering the job market. We therefore sought to identify expected and occurred barriers, keeping them from taking up and staying in employment as well as to identify the solutions used to overcome these barriers. Sixty-six employed individuals with autism--17 of them with autism-specific employment--participated in an online survey. Results showed a variety of possible barriers. Individuals in autism-specific employment named formality problems--problems with organizational and practical process-related aspects of the job entry--most frequently while individuals in non-autism-specific employment mentioned social problems--obstacles concerning communication and human interaction--most. In terms of solutions, both groups used their own resources as much as external help, but differed in their specific strategies. In addition, correlations of an autism-specific employment with general and occupational self-efficacy as well as life and job satisfaction were examined. Possible implications of the results are discussed with regard to problem solving behavior and the use of strengths.

  12. Employer branding

    OpenAIRE

    Mičková, Kateřina

    2008-01-01

    The demand for qualified employees is higher then the offering, both in Czech republic and internationally. Demand for specific skills, in addition to a greater demand for workforce generally, is making employee recruitment and retention much more difficult and expensive. Employer Branding claims to be an answer to this new challenge. This international concept focuses on developing an "employer brand" - mental image of a company as an employer. To achieve this, it is necessary to demonstrate...

  13. Sexual Inequality in the Workplace: An Employer-Specific Analysis of Pay Differences. Discussion Paper No. 502-78.

    Science.gov (United States)

    Halaby, Charles N.

    Sexual inequality is rooted in systematic male-female differences in employer-employee exchanges of productive resources for employment and pay. In an analysis of the effects of the differential distribution of personnel across the major job classes and hierarchical levels of a large utilities firm, the degree to which the male-female salary gap…

  14. Compensation strategies for PET scanners with unconventional scanner geometry

    CERN Document Server

    Gundlich, B; Oehler, M

    2006-01-01

    The small animal PET scanner ClearPET®Neuro, developed at the Forschungszentrum Julich GmbH in cooperation with the Crystal Clear Collaboration (CERN), represents scanners with an unconventional geometry: due to axial and transaxial detector gaps ClearPet®Neuro delivers inhomogeneous sinograms with missing data. When filtered backprojection (FBP) or Fourier rebinning (FORE) are applied, strong geometrical artifacts appear in the images. In this contribution we present a method that takes the geometrical sensitivity into account and converts the measured sinograms into homogeneous and complete data. By this means artifactfree images are achieved using FBP or FORE. Besides an advantageous measurement setup that reduces inhomogeneities and data gaps in the sinograms, a modification of the measured sinograms is necessary. This modification includes two steps: a geometrical normalization and corrections for missing data. To normalize the measured sinograms, computed sinograms are used that describe the geometric...

  15. Autism and Overcoming Job Barriers: Comparing Job-Related Barriers and Possible Solutions in and outside of Autism-Specific Employment

    Science.gov (United States)

    Lorenz, Timo; Frischling, Cora; Cuadros, Raphael; Heinitz, Kathrin

    2016-01-01

    The aim of this study was to discover how individuals with autism succeed in entering the job market. We therefore sought to identify expected and occurred barriers, keeping them from taking up and staying in employment as well as to identify the solutions used to overcome these barriers. Sixty-six employed individuals with autism–17 of them with autism-specific employment–participated in an online survey. Results showed a variety of possible barriers. Individuals in autism-specific employment named formality problems–problems with organizational and practical process-related aspects of the job entry–most frequently while individuals in non-autism-specific employment mentioned social problems–obstacles concerning communication and human interaction–most. In terms of solutions, both groups used their own resources as much as external help, but differed in their specific strategies. In addition, correlations of an autism-specific employment with general and occupational self-efficacy as well as life and job satisfaction were examined. Possible implications of the results are discussed with regard to problem solving behavior and the use of strengths. PMID:26766183

  16. Monte Carlo dose calibration in CT scanner

    International Nuclear Information System (INIS)

    Yadav, Poonam; Ramasubramanian, V.; Subbaiah, K.V.; Thayalan, K.

    2008-01-01

    Computed Tomography (CT) scanner is a high radiation imaging modality compared to radiography. The dose from a CT examination can vary greatly depending on the particular CT scanner used, the area of the body examined, and the operating parameters of the scan. CT is a major contributor to collective effective dose in diagnostic radiology. Apart from the clinical benefits, the widespread use of multislice scanner is increasing radiation level to patient in comparison with conventional CT scanner. So, it becomes necessary to increase awareness about the CT scanner. (author)

  17. A megavoltage CT scanner for radiotherapy verification

    International Nuclear Information System (INIS)

    Lewis, D.G.; Swindell, W.; Morton, E.J.; Evans, P.M.; Xiao, Z.R.

    1992-01-01

    The authors have developed a system for generating megavoltage CT images immediately prior to the administration of external beam radiotherapy. The detector is based on the scanner of Simpson (Simpson et al 1982) - the major differences being a significant reduction in dose required for image formation, faster image formation and greater convenience of use in the clinical setting. Attention has been paid to the problem of ring artefacts in the images. Specifically, a Fourier-space filter has been applied to the sinogram data. After suitable detector calibration, it has been shown that the device operates close to its theoretical specification of 3 mm spatial resolution and a few percent contrast resolution. Ring artefacts continue to be a major source of image degradation. A number of clinical images are presented. (author)

  18. Geometric calibration between PET scanner and structured light scanner

    DEFF Research Database (Denmark)

    Kjer, Hans Martin; Olesen, Oline Vinter; Paulsen, Rasmus Reinhold

    2011-01-01

    Head movements degrade the image quality of high resolution Positron Emission Tomography (PET) brain studies through blurring and artifacts. Manny image reconstruction methods allows for motion correction if the head position is tracked continuously during the study. Our method for motion tracking...... is a structured light scanner placed just above the patient tunnel on the High Resolution Research Tomograph (HRRT, Siemens). It continuously registers point clouds of a part of the patient's face. The relative motion is estimated as the rigid transformation between frames. A geometric calibration between...

  19. Specification ''E'' of the CEFRI concerning the enterprises employing personnel of A or B category working in nuclear facilities

    CERN Document Server

    Int. At. Energy Agency, Wien

    2002-01-01

    This document aims to specify the organization dispositions which have to bee taken by the enterprises employing personnel of A or B category to work in nuclear facilities. These dispositions should allow to respect the demands of the CEFRI in matter of formation, medical control and personnel dosimetry. (A.L.B.)

  20. High efficiency conical scanner for earth resources applications

    Science.gov (United States)

    Bates, J. C.; Dumas, H. J., Jr.

    1975-01-01

    A description is given of a six-arm conical scanner which was selected to provide a continuous line-of-sight scan. Two versions of the instrument are considered. The two versions differ in their weight. The weight of the heavy version is 600 lbs. A light weight design which employs beryllium and aluminum optical components weighs only 350 lbs. A multiplexer and analog-to-digital converter are to be incorporated into the design. Questions of instrument performance are also discussed.

  1. Important considerations for radiochromic film dosimetry with flatbed CCD scanners and EBT GAFCHROMIC[reg] film

    International Nuclear Information System (INIS)

    Lynch, Bart D.; Kozelka, Jakub; Ranade, Manisha K.; Li, Jonathan G.; Simon, William E.; Dempsey, James F.

    2006-01-01

    In this study, we present three significant artifacts that have the potential to negatively impact the accuracy and precision of film dosimetry measurements made using GAFCHROMIC[reg] EBT radiochromic film when read out with CCD flatbed scanners. Films were scanned using three commonly employed instruments: a Macbeth TD932 spot densitometer, an Epson Expression 1680 CCD array scanner, and a Microtek ScanMaker i900 CCD array scanner. For the two scanners we assessed the variation in optical density (OD) of GAFCHROMIC EBT film with scanning bed position, angular rotation of the film with respect to the scan line direction, and temperature inside the scanner due to repeated scanning. Scanning uniform radiochromic films demonstrated a distinct bowing effect in profiles in the direction of the CCD array with a nonuniformity of up to 17%. Profiles along a direction orthogonal to the CCD array demonstrated a 7% variation. A strong angular dependence was found in measurements made with the flatbed scanners; the effect could not be reproduced with the spot densitometer. An IMRT quality assurance film was scanned twice rotating the film 90 deg. between the scans. For films scanned on the Epson scanner, up to 12% variation was observed in unirradiated EBT films rotated between 0 deg. and 90 deg. , which decreased to approximately 8% for EBT films irradiated to 300 cGy. Variations of up to 80% were observed for films scanned with the Microtek scanner. The scanners were found to significantly increase the film temperature with repeated scanning. Film temperature between 18 and 33 deg. C caused OD changes of approximately 7%. Considering these effects, we recommend adherence to a strict scanning protocol that includes: maintaining the orientation of films scanned on flatbed scanners, limiting scanning to the central portion of the scanner bed, and limiting the number of consecutive scans to minimize changes in OD caused by film heating

  2. Complete-arch accuracy of intraoral scanners.

    Science.gov (United States)

    Treesh, Joshua C; Liacouras, Peter C; Taft, Robert M; Brooks, Daniel I; Raiciulescu, Sorana; Ellert, Daniel O; Grant, Gerald T; Ye, Ling

    2018-04-30

    Intraoral scanners have shown varied results in complete-arch applications. The purpose of this in vitro study was to evaluate the complete-arch accuracy of 4 intraoral scanners based on trueness and precision measurements compared with a known reference (trueness) and with each other (precision). Four intraoral scanners were evaluated: CEREC Bluecam, CEREC Omnicam, TRIOS Color, and Carestream CS 3500. A complete-arch reference cast was created and printed using a 3-dimensional dental cast printer with photopolymer resin. The reference cast was digitized using a laboratory-based white light 3-dimensional scanner. The printed reference cast was scanned 10 times with each intraoral scanner. The digital standard tessellation language (STL) files from each scanner were then registered to the reference file and compared with differences in trueness and precision using a 3-dimensional modeling software. Additionally, scanning time was recorded for each scan performed. The Wilcoxon signed rank, Kruskal-Wallis, and Dunn tests were used to detect differences for trueness, precision, and scanning time (α=.05). Carestream CS 3500 had the lowest overall trueness and precision compared with Bluecam and TRIOS Color. The fourth scanner, Omnicam, had intermediate trueness and precision. All of the scanners tended to underestimate the size of the reference file, with exception of the Carestream CS 3500, which was more variable. Based on visual inspection of the color rendering of signed differences, the greatest amount of error tended to be in the posterior aspects of the arch, with local errors exceeding 100 μm for all scans. The single capture scanner Carestream CS 3500 had the overall longest scan times and was significantly slower than the continuous capture scanners TRIOS Color and Omnicam. Significant differences in both trueness and precision were found among the scanners. Scan times of the continuous capture scanners were faster than the single capture scanners

  3. Employment protection

    OpenAIRE

    Stefano Scarpetta

    2014-01-01

    Laws on hiring and firing are intended to protect workers from unfair behavior by employers, to counter imperfections in financial markets that limit workers’ ability to insure themselves against job loss, and to preserve firm-specific human capital. But by imposing costs on firms’ adaptation to changes in demand and technology, employment protection legislation may reduce not only job destruction but also job creation, hindering the efficient allocation of labor and productivity growth....

  4. VIA Employability

    DEFF Research Database (Denmark)

    Andersen, Henrik Mariendal

    2017-01-01

    ’s realized at the entrance to the labor market and in the future career. The purpose is to find opportunities to improve employability-developing activities and to adapt it to specific needs from the students. Based on a number of qualitative interviews and personality tests of the graduates, an increased......The fact that students develop employability during their education is a key point for educational institutions and the focus on this issue has never been greater. This project looks into personal experience from VIA-graduates of "developing their employability" during the education and how it...

  5. Experience with a fuel rod enrichment scanner

    International Nuclear Information System (INIS)

    Kubik, R.N.; Pettus, W.G.

    1975-01-01

    This enrichment scanner views all fuel rods produced at B and W's Commercial Nuclear Fuel Plant. The scanner design is derived from the PAPAS System reported by R. A. Forster, H. D. Menlove, and their associates at Los Alamos. The spatial resolution of the system and smoothing of the data are discussed in detail. The cost-effectiveness of multi-detector versus single detector scanners of this general design is also discussed

  6. Long-Range WindScanner System

    DEFF Research Database (Denmark)

    Vasiljevic, Nikola; Lea, Guillaume; Courtney, Michael

    2016-01-01

    The technical aspects of a multi-Doppler LiDAR instrument, the long-range WindScanner system, are presented accompanied by an overview of the results from several field campaigns. The long-range WindScanner system consists of three spatially-separated, scanning coherent Doppler LiDARs and a remote......-rangeWindScanner system measures the wind field by emitting and directing three laser beams to intersect, and then scanning the beam intersection over a region of interest. The long-range WindScanner system was developed to tackle the need for high-quality observations of wind fields on scales of modern wind turbine...

  7. Multi-parameter CAMAC compatible ADC scanner

    Energy Technology Data Exchange (ETDEWEB)

    Midttun, G J; Ingebretsen, F [Oslo Univ. (Norway). Fysisk Inst.; Johnsen, P J [Norsk Data A.S., Box 163, Oekern, Oslo 5, Norway

    1979-02-15

    A fast ADC scanner for multi-parameter nuclear physics experiments is described. The scanner is based on a standard CAMAC crate, and data from several different experiments can be handled simultaneously through a direct memory access (DMA) channel. The implementation on a PDP-7 computer is outlined.

  8. 3D whole body scanners revisited

    NARCIS (Netherlands)

    Daanen, H.A.M.; Haar, F.B. ter

    2013-01-01

    An overview of whole body scanners in 1998 (H.A.M. Daanen, G.J. Van De Water. Whole body scanners, Displays 19 (1998) 111-120) shortly after they emerged to the market revealed that the systems were bulky, slow, expensive and low in resolution. This update shows that new developments in sensing and

  9. A strand specific high resolution normalization method for chip-sequencing data employing multiple experimental control measurements

    DEFF Research Database (Denmark)

    Enroth, Stefan; Andersson, Claes; Andersson, Robin

    2012-01-01

    High-throughput sequencing is becoming the standard tool for investigating protein-DNA interactions or epigenetic modifications. However, the data generated will always contain noise due to e.g. repetitive regions or non-specific antibody interactions. The noise will appear in the form of a backg......, the background is only used to adjust peak calling and not as a pre-processing step that aims at discerning the signal from the background noise. A normalization procedure that extracts the signal of interest would be of universal use when investigating genomic patterns....

  10. Comparison of working efficiency of terrestrial laser scanner in day and night conditions

    Science.gov (United States)

    Arslan, A. E.; Kalkan, K.

    2013-10-01

    Terrestrial Laser Scanning is a popular and widely used technique to scan existing objects, document historical sites and items, and remodel them if and when needed. Their ability to collect thousands of point data per second makes them an invaluable tool in many areas from engineering to historical reconstruction. There are many scanners in the market with different technical specifications. One main technical specification of laser scanners is range and illumination. In this study, it is tested to be determined the optimal working times of a laser scanner and the scanners consistency with its specifications sheet. In order to conduct this work, series of GNSS measurements in Istanbul Technical University have been carried out, connected to the national reference network, to determine precise positions of target points and the scanner, which makes possible to define a precise distance between the scanner and targets. Those ground surveys has been used for calibration and registration purposes. Two different scan campaigns conducted at 12 am and 11 pm to compare working efficiency of laser scanner in different illumination conditions and targets are measured with a handheld spectro-radiometer in order to determine their reflective characteristics. The obtained results are compared and their accuracies have been analysed.

  11. Enzyme immunoassay for measurement of murine plasminogen activator inhibitor-1, employing a specific antibody produced by the DNA vaccine method.

    Science.gov (United States)

    Yamada, Takayuki; Takagi, Akira; Takeshita, Kyosuke; Yamamoto, Koji; Ito, Masafumi; Matsushita, Tadashi; Murate, Takashi; Saito, Hidehiko; Kojima, Tetsuhito

    2003-01-01

    We developed a sensitive immunoassay to determine the concentration of mouse plasminogen activator inhibitor-1. The assay was a non-competitive sandwich enzyme-linked immunosorbent assay (ELISA) based on the production of a specific polyclonal antibody against mouse plasminogen activator inhibitor type-1 (PAI-1) used both as a trapping and detecting antibody. This antibody was raised in a rabbit by direct introduction of the expression vector plasmid DNA encoding mouse PAI-1, instead of conventional immunization with the purified protein. The standard curve was constructed with a recombinant glutathione S-transferase (GST)-mouse PAI-1 fusion protein (GST-mPAI-1) and dose-response of the assay was linear for GST-mPAI-1 between 6.25 and 100 pM. In order to assess the consistency of the assay, we measured PAI-1 antigen in normal mouse pooled plasma several times. We found that the intra-assay and inter-assay coefficients of variation (CV) were 4.8% and 9.2%, respectively, indicating that the ELISA would be sufficiently repeatable and reproducible. In this assay, lipopolysaccharide (LPS)-injected mice showed substantially higher levels (22-fold) of plasma PAI-1 antigen than did control mice (12.5+/-2.4 vs. 0.58+/-0.16 nM), similar to results reported elsewhere. Taken together, the DNA vaccine method is extremely useful for preparing specific antibodies against mouse PAI-1, which can be utilized to establish the ELISA and analyze the profile of PAI-1 distributions in mice under various conditions. This approach might also be useful for immunological investigation of other coagulation factors and related proteins.

  12. Preliminary assessment of the operating performance and calibration of rectilinear scanners and dose calibrators in Rio de Janeiro - Brazil

    International Nuclear Information System (INIS)

    Mendes, L.; Wegst, A.

    1983-01-01

    Thirty rectilinear scanners and ten dose calibrators were tested for a variety of operating conditions. The test for rectilinear scanners were based on image quality obtained with phantoms of the brain, liver (Williams phantom) and thyroid. The parameters investigated specifically for rectilinear scanners included those under direct control of the operator, such as proper setting of the focal distance, the velocity, the photopeak calibration, contrast correct collimator, line spacing, and background count. (E.G.) [pt

  13. Performance evaluation of 8 CT scanners for clinical use in Italy

    International Nuclear Information System (INIS)

    Pinto, I.; De Denaro, M.; Giribona, P.; Gicericin, C.; Bravar, D.

    1988-01-01

    In the past few years the use of CT scanners has widely spread in Italian care institutions. This methodology has thus become an important creates the need for an accurate study of the various aspects of the phenomenon, e.g. technological, diagnostic and economic. In order to evaluate the quality of the CT scanners used in our country, the majors suppliers of the Italian market were asked to provide us with a unit from their production. Six out of 7 companies complied with our request. A standard protocol was used to evaluate the performance of 8 CT scanners, currently used in Italy. The following parameters were evaluated: spatial resolution, contrast resolution, noise, slice thickness, uniformity, linearity and radiation dose. Five currently-used operating modalities were employed. The results allow an overall assessment of the performance of the 8 CT scanners

  14. Three-dimensional rectilinear scanner

    International Nuclear Information System (INIS)

    O'Neill, W.J.; Strange, D.R.; Miller, A.

    1976-01-01

    A rectilinear scanner for detecting radiation in a plurality of channels utilizing a collimator is described. Each of the channels receives information from a different portion of the collimator. Information separately received is separately messaged and later collated to present a common image. The information is processed by apparatus in a data processing system. This system has means for messaging analog signals corresponding to gamma radiation counts and converting such analog signals to digital signals. This system has means interfacing the digital signals into an address register that communicates directly via data busses to core memory of a central processing unit by cycle stealing and deriving clinically significant information by computation on the resultant digital data. This system has means for storing, retrieving, and displaying the resultant digital data and the resultant derivations therefrom collectively. This is done in such a manner as to allow time sequencing of the aforementioned operations such that the aforementioned operations can be interleaved on a real time basis. 13 claims, 44 figures

  15. Initial results of the quality control in 11 computed tomography scanners at Curitiba

    International Nuclear Information System (INIS)

    Kodlulovich, S; Oliveira, L.; Jakubiak, R.R.; Miquelin, C.A.

    2008-01-01

    The aim of this study was to evaluate the image quality of 11 scanners installed in public and private centers of Curitiba, Brazil. This sample represents 30% of the CT scanners in the city so far. The ACR CT accreditation phantom was used to verify the accomplishment of the scanners performance to the international quality requirements. The results indicate that efforts should be concentrated in the maintenance of the equipments and specific training of the technicians. Most of the scanners have showed some non-conformity. In 27,5% of the sample the positioning requirement wasn't accomplished. The CT number accuracy evaluation showed that in 72,3 % of the scanners the CT numbers were out of the tolerance range, reaching values 35% greater than the limit. The low contrast resolution criteria weren't accomplished in 9% of the scanners. The main concern is that there isn't a specific program to evaluate the image quality of the CT scanners neither to estimate the CT doses in the procedures. (author)

  16. Transmitting Performance Evaluation of ASICs for CMUT-Based Portable Ultrasound Scanners

    DEFF Research Database (Denmark)

    Llimos Muntal, Pere; Diederichsen, Søren Elmin; Jørgensen, Ivan Harald Holger

    2017-01-01

    Portable ultrasound scanners (PUS) have, in recent years, raised a lot of attention, as they can potentially overcome some of the limitations of static scanners. However, PUS have a lot of design limitations including size and power consumption. These restrictions can compromise the image quality...... of the scanner. In order to overcome these restrictions, application specific integrated circuits (ASICs) are needed to implement the electronics. In this work, a comparative study of the transmitting performance of a capacitive micromachined ultrasonic transducer (CMUT) driven by a commercial generic ultrasound...

  17. Product development of Indian cargo scanner

    International Nuclear Information System (INIS)

    2017-01-01

    A cargo scanner is required for nonintrusive screening of suspected cargo containers in trade, using high energy X-ray, to detect any mis-declarations, contraband goods concealment or hidden ammunition or explosives. The cargo scanners help authorities to process large number of suspected cargo with a high level of confidence with other additional benefit of faster clearance, minimised intrusive inspection and generating secured digital record of the process. BARC is in process of developing Indian Cargo Scanner with indigenous X-ray source. Proof of concept and conformance of the results to the international standards has been demonstrated in laboratory. Full scale equipment named as Portal scanner shall be demonstrated at Gamma field Trombay in year 2017. Subsequently the technology transfer may be done to a suitable Indian vendor

  18. A Cross-Platform Smartphone Brain Scanner

    DEFF Research Database (Denmark)

    Larsen, Jakob Eg; Stopczynski, Arkadiusz; Stahlhut, Carsten

    We describe a smartphone brain scanner with a low-costwireless 14-channel Emotiv EEG neuroheadset interfacingwith multiple mobile devices. This personal informaticssystem enables minimally invasive and continuouscapturing of brain imaging data in natural settings. Thesystem applies an inverse...

  19. Experimental validation of a method characterizing bow tie filters in CT scanners using a real-time dose probe

    International Nuclear Information System (INIS)

    McKenney, Sarah E.; Nosratieh, Anita; Gelskey, Dale; Yang Kai; Huang Shinying; Chen Lin; Boone, John M.

    2011-01-01

    Purpose: Beam-shaping or ''bow tie'' (BT) filters are used to spatially modulate the x-ray beam in a CT scanner, but the conventional method of step-and-shoot measurement to characterize a beam's profile is tedious and time-consuming. The theory for characterization of bow tie relative attenuation (COBRA) method, which relies on a real-time dosimeter to address the issues of conventional measurement techniques, was previously demonstrated using computer simulations. In this study, the feasibility of the COBRA theory is further validated experimentally through the employment of a prototype real-time radiation meter and a known BT filter. Methods: The COBRA method consisted of four basic steps: (1) The probe was placed at the edge of a scanner's field of view; (2) a real-time signal train was collected as the scanner's gantry rotated with the x-ray beam on; (3) the signal train, without a BT filter, was modeled using peak values measured in the signal train of step 2; and (4) the relative attenuation of the BT filter was estimated from filtered and unfiltered data sets. The prototype probe was first verified to have an isotropic and linear response to incident x-rays. The COBRA method was then tested on a dedicated breast CT scanner with a custom-designed BT filter and compared to the conventional step-and-shoot characterization of the BT filter. Using basis decomposition of dual energy signal data, the thickness of the filter was estimated and compared to the BT filter's manufacturing specifications. The COBRA method was also demonstrated with a clinical whole body CT scanner using the body BT filter. The relative attenuation was calculated at four discrete x-ray tube potentials and used to estimate the thickness of the BT filter. Results: The prototype probe was found to have a linear and isotropic response to x-rays. The relative attenuation produced from the COBRA method fell within the error of the relative attenuation measured with the step-and-shoot method

  20. Experimental characterization of the Clear-PEM scanner spectrometric performance

    Energy Technology Data Exchange (ETDEWEB)

    Bugalho, R; Carrico, B; Ferreira, C S; Frade, M; Ferreira, M; Moura, R; Ortigao, C; Pinheiro, J F; Rodrigues, P; Rolo, I; Silva, J C; Trindade, A; Varela, J [Laboratorio de Instrumentacao e Fisica Experimental de Particulas (LIP), Av. Elias Garcia 14-1, 1000-149 Lisboa (Portugal)], E-mail: frade@lip.pt

    2009-10-15

    In the framework of the Clear-PEM project for the construction of a high-resolution and high-specificity scanner for breast cancer imaging, a Positron Emission Mammography tomograph has been developed and installed at the Instituto Portugues de Oncologia do Porto hospital. The Clear-PEM scanner is mainly composed by two planar detector heads attached to a robotic arm, trigger/data acquisition electronics system and computing servers. The detector heads hold crystal matrices built from 2 x 2 x 20 mm{sup 3} LYSO:Ce crystals readout by Hamamatsu S8550 APD arrays. The APDs are optically coupled to both ends of the 6144 crystals in order to extract the DOI information for each detected event. Each one of 12288 APD's pixels is read and controlled by Application Specific Integrated Circuits water-cooled by an external cooling unit. The Clear-PEM frontend boards innovative design results in a unprecedented integration of the crystal matrices, APDs and ASICs, making Clear-PEM the PET scanner with the highest number of APD pixels ever integrated so far. In this paper, the scanner's main technical characteristics, calibration strategies and the first spectrometric performance evaluation in a clinical environment are presented. The first commissioning results show 99.7% active channels, which, after calibration, have inter-pixel and absolute gain distributions with dispersions of, respectively, 12.2% and 15.3%, demonstrating that despite the large number of channels, the system is uniform. The mean energy resolution at 511 keV is of 15.9%, with a 8.8% dispersion, and the mean C{sub DOI}{sup -1} is 5.9%/mm, with a 7.8% dispersion. The coincidence time resolution, at 511 keV, for a energy window between 400 and 600 keV, is 5.2 ns FWHM.

  1. Large angle and high linearity two-dimensional laser scanner based on voice coil actuators

    Science.gov (United States)

    Wu, Xin; Chen, Sihai; Chen, Wei; Yang, Minghui; Fu, Wen

    2011-10-01

    A large angle and high linearity two-dimensional laser scanner with an in-house ingenious deflection angle detecting system is developed based on voice coil actuators direct driving mechanism. The specially designed voice coil actuators make the steering mirror moving at a sufficiently large angle. Frequency sweep method based on virtual instruments is employed to achieve the natural frequency of the laser scanner. The response shows that the performance of the laser scanner is limited by the mechanical resonances. The closed-loop controller based on mathematical model is used to reduce the oscillation of the laser scanner at resonance frequency. To design a qualified controller, the model of the laser scanner is set up. The transfer function of the model is identified with MATLAB according to the tested data. After introducing of the controller, the nonlinearity decreases from 13.75% to 2.67% at 50 Hz. The laser scanner also has other advantages such as large deflection mirror, small mechanical structure, and high scanning speed.

  2. Evaluation of PeneloPET Simulations of Biograph PET/CT Scanners

    Science.gov (United States)

    Abushab, K. M.; Herraiz, J. L.; Vicente, E.; Cal-González, J.; España, S.; Vaquero, J. J.; Jakoby, B. W.; Udías, J. M.

    2016-06-01

    Monte Carlo (MC) simulations are widely used in positron emission tomography (PET) for optimizing detector design, acquisition protocols, and evaluating corrections and reconstruction methods. PeneloPET is a MC code based on PENELOPE, for PET simulations which considers detector geometry, acquisition electronics and materials, and source definitions. While PeneloPET has been successfully employed and validated with small animal PET scanners, it required a proper validation with clinical PET scanners including time-of-flight (TOF) information. For this purpose, we chose the family of Biograph PET/CT scanners: the Biograph True-Point (B-TP), Biograph True-Point with TrueV (B-TPTV) and the Biograph mCT. They have similar block detectors and electronics, but a different number of rings and configuration. Some effective parameters of the simulations, such as the dead-time and the size of the reflectors in the detectors, were adjusted to reproduce the sensitivity and noise equivalent count (NEC) rate of the B-TPTV scanner. These parameters were then used to make predictions of experimental results such as sensitivity, NEC rate, spatial resolution, and scatter fraction (SF), from all the Biograph scanners and some variations of them (energy windows and additional rings of detectors). Predictions agree with the measured values for the three scanners, within 7% (sensitivity and NEC rate) and 5% (SF). The resolution obtained for the B-TPTV is slightly better (10%) than the experimental values. In conclusion, we have shown that PeneloPET is suitable for simulating and investigating clinical systems with good accuracy and short computational time, though some effort tuning of a few parameters of the scanners modeled may be needed in case that the full details of the scanners studied are not available.

  3. Neurosurgical operating computerized tomographic scanner system

    International Nuclear Information System (INIS)

    Okudera, Hiroshi; Sugita, Kenichiro; Kobayashi, Shigeaki; Kimishima, Sakae; Yoshida, Hisashi.

    1988-01-01

    A neurosurgical operating computerized tomography scanner system is presented. This system has been developed for obtaining intra- and postoperative CT images in the operating room. A TCT-300 scanner (manufactured by the Toshiba Co., Tokyo) is placed in the operating room. The realization of a true intraoperative CT image requires certain improvements in the CT scanner and operating table. To adjust the axis of the co-ordinates of the motor system of the MST-7000 microsurgical operating table (manufactured by the Mizuho Ika Co., Tokyo) to the CT scanner, we have designed an interface and a precise motor system so that the computer of the CT scanner can directly control the movement of the operating table. Furthermore, a new head-fixation system has been designed for producing artifact-free intraoperative CT images. The head-pins of the head-fixation system are made of carbon-fiber bars and titanium tips. A simulation study of the total system in the operating room with the CT scanner, operating table, and head holder using a skull model yielded a degree of error similar to that in the phantom testing of the original scanner. Three patients underwent resection of a glial tumor using this system. Intraoperative CT scans taken after dural opening showed a bulging of the cortex, a shift in the central structure, and a displacement of the cortical subarachnoid spaces under the influence of gravity. With a contrast medium the edge of the surrounding brain after resection was enhanced and the residual tumor mass was demonstrated clearly. This system makes it possible to obtain a noninvasive intraoperative image in a situation where structural shifts are taking place. (author)

  4. A flexible and wearable terahertz scanner

    Science.gov (United States)

    Suzuki, D.; Oda, S.; Kawano, Y.

    2016-12-01

    Imaging technologies based on terahertz (THz) waves have great potential for use in powerful non-invasive inspection methods. However, most real objects have various three-dimensional curvatures and existing THz technologies often encounter difficulties in imaging such configurations, which limits the useful range of THz imaging applications. Here, we report the development of a flexible and wearable THz scanner based on carbon nanotubes. We achieved room-temperature THz detection over a broad frequency band ranging from 0.14 to 39 THz and developed a portable THz scanner. Using this scanner, we performed THz imaging of samples concealed behind opaque objects, breakages and metal impurities of a bent film and multi-view scans of a syringe. We demonstrated a passive biometric THz scan of a human hand. Our results are expected to have considerable implications for non-destructive and non-contact inspections, such as medical examinations for the continuous monitoring of health conditions.

  5. Quality assurance of computed tomography (CT) scanners

    International Nuclear Information System (INIS)

    Sankaran, A.; Sanu, K.K. . Email : a_sankaran@vsnl.com

    2004-01-01

    This article reviews the present status of research work and development of various test objects, phantoms and detector/instrumentation systems for quality assurance (QA) of computed tomography (CT) scanners, carried out in advanced countries, with emphasis on similar work done in this research centre. CT scanner is a complex equipment and routine quality control procedures are essential to the maintenance of image quality with optimum patient dose. Image quality can be ensured only through correlation between prospective monitoring of system components and tests of overall performance with standard phantoms. CT examinations contribute a large share to the population dose in advanced countries. The unique dosimetry problems in CT necessitate special techniques. This article describes a comprehensive kit developed indigenously for the following QA and type approval tests as well as for research studies on image quality/dosimetry on CT scanners

  6. Manually operated small envelope scanner system

    Energy Technology Data Exchange (ETDEWEB)

    Sword, Charles Keith

    2017-04-18

    A scanner system and method for acquisition of position-based ultrasonic inspection data are described. The scanner system includes an inspection probe and a first non-contact linear encoder having a first sensor and a first scale to track inspection probe position. The first sensor is positioned to maintain a continuous non-contact interface between the first sensor and the first scale and to maintain a continuous alignment of the first sensor with the inspection probe. The scanner system may be used to acquire two-dimensional inspection probe position data by including a second non-contact linear encoder having a second sensor and a second scale, the second sensor positioned to maintain a continuous non-contact interface between the second sensor and the second scale and to maintain a continuous alignment of the second sensor with the first sensor.

  7. Multimodality Registration without a Dedicated Multimodality Scanner

    Directory of Open Access Journals (Sweden)

    Bradley J. Beattie

    2007-03-01

    Full Text Available Multimodality scanners that allow the acquisition of both functional and structural image sets on a single system have recently become available for animal research use. Although the resultant registered functional/structural image sets can greatly enhance the interpretability of the functional data, the cost of multimodality systems can be prohibitive, and they are often limited to two modalities, which generally do not include magnetic resonance imaging. Using a thin plastic wrap to immobilize and fix a mouse or other small animal atop a removable bed, we are able to calculate registrations between all combinations of four different small animal imaging scanners (positron emission tomography, single-photon emission computed tomography, magnetic resonance, and computed tomography [CT] at our disposal, effectively equivalent to a quadruple-modality scanner. A comparison of serially acquired CT images, with intervening acquisitions on other scanners, demonstrates the ability of the proposed procedures to maintain the rigidity of an anesthetized mouse during transport between scanners. Movement of the bony structures of the mouse was estimated to be 0.62 mm. Soft tissue movement was predominantly the result of the filling (or emptying of the urinary bladder and thus largely constrained to this region. Phantom studies estimate the registration errors for all registration types to be less than 0.5 mm. Functional images using tracers targeted to known structures verify the accuracy of the functional to structural registrations. The procedures are easy to perform and produce robust and accurate results that rival those of dedicated multimodality scanners, but with more flexible registration combinations and while avoiding the expense and redundancy of multimodality systems.

  8. How flatbed scanners upset accurate film dosimetry

    Science.gov (United States)

    van Battum, L. J.; Huizenga, H.; Verdaasdonk, R. M.; Heukelom, S.

    2016-01-01

    Film is an excellent dosimeter for verification of dose distributions due to its high spatial resolution. Irradiated film can be digitized with low-cost, transmission, flatbed scanners. However, a disadvantage is their lateral scan effect (LSE): a scanner readout change over its lateral scan axis. Although anisotropic light scattering was presented as the origin of the LSE, this paper presents an alternative cause. Hereto, LSE for two flatbed scanners (Epson 1680 Expression Pro and Epson 10000XL), and Gafchromic film (EBT, EBT2, EBT3) was investigated, focused on three effects: cross talk, optical path length and polarization. Cross talk was examined using triangular sheets of various optical densities. The optical path length effect was studied using absorptive and reflective neutral density filters with well-defined optical characteristics (OD range 0.2-2.0). Linear polarizer sheets were used to investigate light polarization on the CCD signal in absence and presence of (un)irradiated Gafchromic film. Film dose values ranged between 0.2 to 9 Gy, i.e. an optical density range between 0.25 to 1.1. Measurements were performed in the scanner’s transmission mode, with red-green-blue channels. LSE was found to depend on scanner construction and film type. Its magnitude depends on dose: for 9 Gy increasing up to 14% at maximum lateral position. Cross talk was only significant in high contrast regions, up to 2% for very small fields. The optical path length effect introduced by film on the scanner causes 3% for pixels in the extreme lateral position. Light polarization due to film and the scanner’s optical mirror system is the main contributor, different in magnitude for the red, green and blue channel. We concluded that any Gafchromic EBT type film scanned with a flatbed scanner will face these optical effects. Accurate dosimetry requires correction of LSE, therefore, determination of the LSE per color channel and dose delivered to the film.

  9. How flatbed scanners upset accurate film dosimetry

    International Nuclear Information System (INIS)

    Van Battum, L J; Verdaasdonk, R M; Heukelom, S; Huizenga, H

    2016-01-01

    Film is an excellent dosimeter for verification of dose distributions due to its high spatial resolution. Irradiated film can be digitized with low-cost, transmission, flatbed scanners. However, a disadvantage is their lateral scan effect (LSE): a scanner readout change over its lateral scan axis. Although anisotropic light scattering was presented as the origin of the LSE, this paper presents an alternative cause. Hereto, LSE for two flatbed scanners (Epson 1680 Expression Pro and Epson 10000XL), and Gafchromic film (EBT, EBT2, EBT3) was investigated, focused on three effects: cross talk, optical path length and polarization. Cross talk was examined using triangular sheets of various optical densities. The optical path length effect was studied using absorptive and reflective neutral density filters with well-defined optical characteristics (OD range 0.2–2.0). Linear polarizer sheets were used to investigate light polarization on the CCD signal in absence and presence of (un)irradiated Gafchromic film. Film dose values ranged between 0.2 to 9 Gy, i.e. an optical density range between 0.25 to 1.1. Measurements were performed in the scanner’s transmission mode, with red–green–blue channels. LSE was found to depend on scanner construction and film type. Its magnitude depends on dose: for 9 Gy increasing up to 14% at maximum lateral position. Cross talk was only significant in high contrast regions, up to 2% for very small fields. The optical path length effect introduced by film on the scanner causes 3% for pixels in the extreme lateral position. Light polarization due to film and the scanner’s optical mirror system is the main contributor, different in magnitude for the red, green and blue channel. We concluded that any Gafchromic EBT type film scanned with a flatbed scanner will face these optical effects. Accurate dosimetry requires correction of LSE, therefore, determination of the LSE per color channel and dose delivered to the film. (paper)

  10. A simple scanner for Compton tomography

    CERN Document Server

    Cesareo, R; Brunetti, A; Golosio, B; Castellano, A

    2002-01-01

    A first generation CT-scanner was designed and constructed to carry out Compton images. This CT-scanner is composed of a 80 kV, 5 mA X-ray tube and a NaI(Tl) X-ray detector; the tube is strongly collimated, generating a X-ray beam of 2 mm diameter, whilst the detector is not collimated to collect Compton photons from the whole irradiated cylinder. The performances of the equipment were tested contemporaneous transmission and Compton images.

  11. The performance characteristics of the Philips Gemini PET/CT scanner

    International Nuclear Information System (INIS)

    O'Keefe, G.J.; Papenfuss, A.T.; Scott, A.M.; Rowe, C.C.

    2002-01-01

    Full text: The Department of Nuclear Medicine, Centre for PET at the ARMC is commissioning a next generation PET/CT scanner based on gadolinium silicic dioxide (GSO) crystal technology to replace the BGO crystal PET scanner that has been in operation since 1992. The Gemini PET/CT scanner is a fully 3D PET system which offers significantly increased resolution and sensitivity allowing wholebody scans in under 30 minutes. Until the late 90's, PET scanners were largely used with septa for neurological imaging and the performance characteristics of PET scanners were presented according to the NEMA-NU2-94 standard which specifically addresses the performance of PET scanners for neurological applications. PET is now largely used without septa for oncological imaging and as such, the NEMA-NU2-94 standard does not adequately reflect performance. The NEMA-NU2-2001 standard was designed to incorporate the effects of out-of-FOV activity and its contribution to performance by virtue of the increased scatter and randoms that result when performing wholebody scans without the use of septa. As part of the acceptance program of the Allegro/Gemini systems, the NEMA-NU2-2001 standard will be used to characterise the spatial resolution, sensitivity, randoms and scatter contributions and the Noise Equivalent Count rate (NECr). These results will be presented and compared with the ECAT 951/31R performance characteristics. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  12. Quality assurance for CT scanners and NMR imagers

    International Nuclear Information System (INIS)

    Williams, J.L.; Howarth, W.

    1986-01-01

    Quality Assurance is an essential part of management and the application of its disciplines to the purchase and use of CT and MR scanners is particularly important. The Purchaser and User have the leading role. They must take into account the need for a precise specification which will form part of the contract placed on the Supplier, the basis of acceptance and of maintenance of the equipment. The training of staff is also important. The Scientific and Technical Branch of the DHSS has a programme of work intended to help the Purchaser and User in this role. (author)

  13. Inter laboratory comparison of industrial CT scanners

    DEFF Research Database (Denmark)

    Angel, Jais Andreas Breusch; Cantatore, Angela; De Chiffre, Leonardo

    2012-01-01

    In this report results from an intercomparison of industrial CT scanners are presented. Three audit items, similar to common industrial parts, were selected for circulation: a single polymer part with complex geometry (Item 1), a simple geometry part made of two polymers (Item 2) and a miniature...

  14. Developments in holographic-based scanner designs

    Science.gov (United States)

    Rowe, David M.

    1997-07-01

    Holographic-based scanning systems have been used for years in the high resolution prepress markets where monochromatic lasers are generally utilized. However, until recently, due to the dispersive properties of holographic optical elements (HOEs), along with the high cost associated with recording 'master' HOEs, holographic scanners have not been able to penetrate major scanning markets such as the laser printer and digital copier markets, low to mid-range imagesetter markets, and the non-contact inspection scanner market. Each of these markets has developed cost effective laser diode based solutions using conventional scanning approaches such as polygon/f-theta lens combinations. In order to penetrate these markets, holographic-based systems must exhibit low cost and immunity to wavelength shifts associated with laser diodes. This paper describes recent developments in the design of holographic scanners in which multiple HOEs, each possessing optical power, are used in conjunction with one curved mirror to passively correct focal plane position errors and spot size changes caused by the wavelength instability of laser diodes. This paper also describes recent advancements in low cost production of high quality HOEs and curved mirrors. Together these developments allow holographic scanners to be economically competitive alternatives to conventional devices in every segment of the laser scanning industry.

  15. A PET scanner developed by CERN

    CERN Multimedia

    Laurent Guiraud

    1998-01-01

    This image shows a Position Emission Tomography (PET) scanner at the Hopital Cantonal Universitaire de Genève. Development of the multiwire proportional chamber at CERN in the mid-1970s was soon seen as a potential device for medical imaging. It is much more sensitive than previous devices and greatly reduced the dose of radiation received by the patient.

  16. Wire scanner software and firmware issues

    International Nuclear Information System (INIS)

    Gilpatrick, John Doug

    2008-01-01

    The Los Alamos Neutron Science Center facility presently has 110 slow wire scanning profile measurement instruments located along its various beam lines. These wire scanners were developed and have been operating for at least 30 years. While the wire scanners solved many problems to operate and have served the facility well they have increasingly suffered from several problems or limitations, such as maintenance and reliability problems, antiquated components, slow data acquisition, and etc. In order to refurbish these devices, these wire scanners will be replaced with newer versions. The replacement will consist of a completely new beam line actuator, new cables, new electronics and brand new software and firmware. This note describes the functions and modes of operation that LabVIEW VI software on the real time controller and FPGA LabVIEW firmware will be required. It will be especially interesting to understand the overall architecture of these LabVIEW VIs. While this note will endeavor to describe all of the requirements and issues for the wire scanners, undoubtedly, there will be missing details that will be added as time progresses.

  17. Learning and Teaching with a Computer Scanner

    Science.gov (United States)

    Planinsic, G.; Gregorcic, B.; Etkina, E.

    2014-01-01

    This paper introduces the readers to simple inquiry-based activities (experiments with supporting questions) that one can do with a computer scanner to help students learn and apply the concepts of relative motion in 1 and 2D, vibrational motion and the Doppler effect. We also show how to use these activities to help students think like…

  18. Current segmented gamma-ray scanner technology

    International Nuclear Information System (INIS)

    Bjork, C.W.

    1987-01-01

    A new generation of segmented gamma-ray scanners has been developed at Los Alamos for scrap and waste measurements at the Savannah River Plant and the Los Alamos Plutonium Facility. The new designs are highly automated and exhibit special features such as good segmentation and thorough shielding to improve performance

  19. Get Mobile – The Smartphone Brain Scanner

    DEFF Research Database (Denmark)

    Stahlhut, Carsten; Stopczynski, Arkadiusz; Petersen, Michael Kai

    This demonstration will provide live-interaction with a smartphone brain scanner consisting of a low-cost wireless 14-channel EEG headset (Emotiv Epoc) and a mobile device. With our system it is possible to perform real-time functional brain imaging on a smartphone device, including stimulus...

  20. Scanner and irradiation: optimization of protocols

    International Nuclear Information System (INIS)

    Duchemin, J.; Martine-Rollet, B.; Lienart, S.; Mobailly, M.; Florin, J.P.; Beregi, J.P.; Puech, N.

    2006-01-01

    The irradiation of the patient or the personnel increased with the arrival of the multi-detector scanners. The objective of this work is to realize a didactic poster to inform and make sensitive on the irradiation with scan so that to propose solutions of protection. (N.C.)

  1. submitter Dynamical Models of a Wire Scanner

    CERN Document Server

    Barjau, Ana; Dehning, Bernd

    2016-01-01

    The accuracy of the beam profile measurements achievable by the current wire scanners at CERN is limited by the vibrations of their mechanical parts. In particular, the vibrations of the carbon wire represent the major source of wire position uncertainty which limits the beam profile measurement accuracy. In the coming years, due to the Large Hadron Collider (LHC) luminosity upgrade, a wire traveling speed up to 20 $m s^{−1}$ and a position measurement accuracy of the order of 1 μm will be required. A new wire scanner design based on the understanding of the wire vibration origin is therefore needed. We present the models developed to understand the main causes of the wire vibrations observed in an existing wire scanner. The development and tuning of those models are based on measurements and tests performed on that CERN proton synchrotron (PS) scanner. The final model for the (wire + fork) system has six degrees-of-freedom (DOF). The wire equations contain three different excitation terms: inertia...

  2. Errors in MR-based attenuation correction for brain imaging with PET/MR scanners

    International Nuclear Information System (INIS)

    Rota Kops, Elena; Herzog, Hans

    2013-01-01

    Aim: Attenuation correction of PET data acquired by hybrid MR/PET scanners remains a challenge, even if several methods for brain and whole-body measurements have been developed recently. A template-based attenuation correction for brain imaging proposed by our group is easy to handle and delivers reliable attenuation maps in a short time. However, some potential error sources are analyzed in this study. We investigated the choice of template reference head among all the available data (error A), and possible skull anomalies of the specific patient, such as discontinuities due to surgery (error B). Materials and methods: An anatomical MR measurement and a 2-bed-position transmission scan covering the whole head and neck region were performed in eight normal subjects (4 females, 4 males). Error A: Taking alternatively one of the eight heads as reference, eight different templates were created by nonlinearly registering the images to the reference and calculating the average. Eight patients (4 females, 4 males; 4 with brain lesions, 4 w/o brain lesions) were measured in the Siemens BrainPET/MR scanner. The eight templates were used to generate the patients' attenuation maps required for reconstruction. ROI and VOI atlas-based comparisons were performed employing all the reconstructed images. Error B: CT-based attenuation maps of two volunteers were manipulated by manually inserting several skull lesions and filling a nasal cavity. The corresponding attenuation coefficients were substituted with the water's coefficient (0.096/cm). Results: Error A: The mean SUVs over the eight templates pairs for all eight patients and all VOIs did not differ significantly one from each other. Standard deviations up to 1.24% were found. Error B: After reconstruction of the volunteers' BrainPET data with the CT-based attenuation maps without and with skull anomalies, a VOI-atlas analysis was performed revealing very little influence of the skull lesions (less than 3%), while the filled

  3. Errors in MR-based attenuation correction for brain imaging with PET/MR scanners

    Science.gov (United States)

    Rota Kops, Elena; Herzog, Hans

    2013-02-01

    AimAttenuation correction of PET data acquired by hybrid MR/PET scanners remains a challenge, even if several methods for brain and whole-body measurements have been developed recently. A template-based attenuation correction for brain imaging proposed by our group is easy to handle and delivers reliable attenuation maps in a short time. However, some potential error sources are analyzed in this study. We investigated the choice of template reference head among all the available data (error A), and possible skull anomalies of the specific patient, such as discontinuities due to surgery (error B). Materials and methodsAn anatomical MR measurement and a 2-bed-position transmission scan covering the whole head and neck region were performed in eight normal subjects (4 females, 4 males). Error A: Taking alternatively one of the eight heads as reference, eight different templates were created by nonlinearly registering the images to the reference and calculating the average. Eight patients (4 females, 4 males; 4 with brain lesions, 4 w/o brain lesions) were measured in the Siemens BrainPET/MR scanner. The eight templates were used to generate the patients' attenuation maps required for reconstruction. ROI and VOI atlas-based comparisons were performed employing all the reconstructed images. Error B: CT-based attenuation maps of two volunteers were manipulated by manually inserting several skull lesions and filling a nasal cavity. The corresponding attenuation coefficients were substituted with the water's coefficient (0.096/cm). ResultsError A: The mean SUVs over the eight templates pairs for all eight patients and all VOIs did not differ significantly one from each other. Standard deviations up to 1.24% were found. Error B: After reconstruction of the volunteers' BrainPET data with the CT-based attenuation maps without and with skull anomalies, a VOI-atlas analysis was performed revealing very little influence of the skull lesions (less than 3%), while the filled nasal

  4. Optical Automatic Car Identification (OACI) : Volume 1. Advanced System Specification.

    Science.gov (United States)

    1978-12-01

    A performance specification is provided in this report for an Optical Automatic Car Identification (OACI) scanner system which features 6% improved readability over existing industry scanner systems. It also includes the analysis and rationale which ...

  5. Body scanners: are they dangerous for health?; Scanners corporels: dangereux pour la sante?

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2010-07-01

    As there is a debate about the risk of cancer and of congenital malformation associated with the use of body scanners, notably in airports, this document recalls and comments the IAEA statement on this issue. According to a study performed by this international agency, the irradiation dose is very low. But the French IRSN is more prudent and recommends not to use X ray scanner, but to look for technologies which do not use ionizing radiation

  6. Estimation of time averages from irregularly spaced observations - With application to coastal zone color scanner estimates of chlorophyll concentration

    Science.gov (United States)

    Chelton, Dudley B.; Schlax, Michael G.

    1991-01-01

    The sampling error of an arbitrary linear estimate of a time-averaged quantity constructed from a time series of irregularly spaced observations at a fixed located is quantified through a formalism. The method is applied to satellite observations of chlorophyll from the coastal zone color scanner. The two specific linear estimates under consideration are the composite average formed from the simple average of all observations within the averaging period and the optimal estimate formed by minimizing the mean squared error of the temporal average based on all the observations in the time series. The resulting suboptimal estimates are shown to be more accurate than composite averages. Suboptimal estimates are also found to be nearly as accurate as optimal estimates using the correct signal and measurement error variances and correlation functions for realistic ranges of these parameters, which makes it a viable practical alternative to the composite average method generally employed at present.

  7. Occurrence and characteristics of mutual interference between LIDAR scanners

    Science.gov (United States)

    Kim, Gunzung; Eom, Jeongsook; Park, Seonghyeon; Park, Yongwan

    2015-05-01

    The LIDAR scanner is at the heart of object detection of the self-driving car. Mutual interference between LIDAR scanners has not been regarded as a problem because the percentage of vehicles equipped with LIDAR scanners was very rare. With the growing number of autonomous vehicle equipped with LIDAR scanner operated close to each other at the same time, the LIDAR scanner may receive laser pulses from other LIDAR scanners. In this paper, three types of experiments and their results are shown, according to the arrangement of two LIDAR scanners. We will show the probability that any LIDAR scanner will interfere mutually by considering spatial and temporal overlaps. It will present some typical mutual interference scenario and report an analysis of the interference mechanism.

  8. 21 CFR 882.1925 - Ultrasonic scanner calibration test block.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ultrasonic scanner calibration test block. 882... Ultrasonic scanner calibration test block. (a) Identification. An ultrasonic scanner calibration test block is a block of material with known properties used to calibrate ultrasonic scanning devices (e.g., the...

  9. Clinical applications of a high quantum utilization scanner. Final report

    International Nuclear Information System (INIS)

    Crandall, P.H.; Cassen, B.

    1973-04-01

    The clinical usefulness of a tomographic imaging process employing a fast rectilinear scanner consisted of a spherical-cap nest of seven individual detectors (3'' x 1 / 2 '' activated sodium iodide) collimated to a common focal point at 10 cm. Hydraulic drives permitted a fast rectilinear scan to be made and, when raised or lowered, at different planes. Patients with well-defined brain lesions were studied using /sup 99m/Tc-pertechnetate or 203 Hg-chlormerodrin as tracers by measuring three dimensions of their lesions and anatomical location at the time of operation. Brain maps were used to identify this location at operation and also the location of images traced from film density displays of a conventional radioisotopic scan, the tomographic scan, and cerebral angiograms. (U.S.)

  10. Analysis of pellet coating uniformity using a computer scanner.

    Science.gov (United States)

    Šibanc, Rok; Luštrik, Matevž; Dreu, Rok

    2017-11-30

    A fast method for pellet coating uniformity analysis, using a commercial computer scanner was developed. The analysis of the individual particle coating thicknesses was based on using a transparent orange colored coating layer deposited on white pellet cores. Besides the analysis of the coating thickness the information of pellet size and shape was obtained as well. Particle size dependent coating thickness and particle size independent coating variability was calculated by combining the information of coating thickness and pellet size. Decoupling coating thickness variation sources is unique to presented method. For each coating experiment around 10000 pellets were analyzed, giving results with a high statistical confidence. Proposed method was employed for the performance evaluation of classical Wurster and swirl enhanced Wurster coater operated at different gap settings and air flow rates. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Detector Position Estimation for PET Scanners.

    Science.gov (United States)

    Pierce, Larry; Miyaoka, Robert; Lewellen, Tom; Alessio, Adam; Kinahan, Paul

    2012-06-11

    Physical positioning of scintillation crystal detector blocks in Positron Emission Tomography (PET) scanners is not always exact. We test a proof of concept methodology for the determination of the six degrees of freedom for detector block positioning errors by utilizing a rotating point source over stepped axial intervals. To test our method, we created computer simulations of seven Micro Crystal Element Scanner (MiCES) PET systems with randomized positioning errors. The computer simulations show that our positioning algorithm can estimate the positions of the block detectors to an average of one-seventh of the crystal pitch tangentially, and one-third of the crystal pitch axially. Virtual acquisitions of a point source grid and a distributed phantom show that our algorithm improves both the quantitative and qualitative accuracy of the reconstructed objects. We believe this estimation algorithm is a practical and accurate method for determining the spatial positions of scintillation detector blocks.

  12. Detector position estimation for PET scanners

    International Nuclear Information System (INIS)

    Pierce, Larry; Miyaoka, Robert; Lewellen, Tom; Alessio, Adam; Kinahan, Paul

    2012-01-01

    Physical positioning of scintillation crystal detector blocks in Positron Emission Tomography (PET) scanners is not always exact. We test a proof of concept methodology for the determination of the six degrees of freedom for detector block positioning errors by utilizing a rotating point source over stepped axial intervals. To test our method, we created computer simulations of seven Micro Crystal Element Scanner (MiCES) PET systems with randomized positioning errors. The computer simulations show that our positioning algorithm can estimate the positions of the block detectors to an average of one-seventh of the crystal pitch tangentially, and one-third of the crystal pitch axially. Virtual acquisitions of a point source grid and a distributed phantom show that our algorithm improves both the quantitative and qualitative accuracy of the reconstructed objects. We believe this estimation algorithm is a practical and accurate method for determining the spatial positions of scintillation detector blocks.

  13. Ghost signals in Allison emittance scanners

    International Nuclear Information System (INIS)

    Stockli, Martin P.; Leitner, M.; Moehs, D.P.; Keller, R.; Welton, R.F.

    2004-01-01

    For over 20 years, Allison scanners have been used to measure emittances of low-energy ion beams. We show that scanning large trajectory angles produces ghost signals caused by the sampled beamlet impacting on an electric deflection plate. The ghost signal strength is proportional to the amount of beam entering the scanner. Depending on the ions, and their velocity, the ghost signals can have the opposite or the same polarity as the main beam signals. The ghost signals cause significant errors in the emittance estimates because they appear at large trajectory angles. These ghost signals often go undetected because they partly overlap with the real signals, are mostly below the 1% level, and often hide in the noise. A simple deflection plate modification is shown to reduce the ghost signal strength by over 99%

  14. Ghost Signals In Allison Emittance Scanners

    International Nuclear Information System (INIS)

    Stockli, Martin P.; Leitner, M.; Keller, R.; Moehs, D.P.; Welton, R. F.

    2005-01-01

    For over 20 years, Allison scanners have been used to measure emittances of low-energy ion beams. We show that scanning large trajectory angles produces ghost signals caused by the sampled beamlet impacting on an electric deflection plate. The ghost signal strength is proportional to the amount of beam entering the scanner. Depending on the ions, and their velocity, the ghost signals can have the opposite or the same polarity as the main beam signals. The ghost signals cause significant errors in the emittance estimates because they appear at large trajectory angles. These ghost signals often go undetected because they partly overlap with the real signals, are mostly below the 1% level, and often hide in the noise. A simple deflection plate modification is shown to reduce the ghost signal strength by over 99%

  15. Development of high pressure pipe scanners

    International Nuclear Information System (INIS)

    Kim, Jae H.; Lee, Jae C.; Moon, Soon S.; Eom, Heung S.; Choi, Yu R.

    1998-12-01

    This report describes an automatic ultrasonic scanning system for pressure pipe welds, which was developed in this project using recent advanced technologies on mobile robot and computer. The system consists of two modules: a robot scanner module which navigates and manipulates scanning devices, and a data acquisition module which generates ultrasonic signal and processes the data from the scanner. The robot has 4 magnetic wheels and 2 -axis manipulator on which ultrasonic transducer attached. The wheeled robot can navigate curved surface such as outer wall of circular pipes. Magnetic wheels were optimally designed through magnetic field analysis. Free surface sensing and line tracking control algorithm were developed and implemented, and the control devices and software can be used in practical inspection works. We expect our system can contribute to reduction of inspection time, performance enhancement, and effective management of inspection results

  16. Imaging Scanner Usage in Radiochemical Purity Test

    International Nuclear Information System (INIS)

    Norhafizah Othman; Yahaya Talib; Wan Hamirul Bahrin Wan Kamal

    2011-01-01

    Imaging Scanner model BIOSCAN AR-2000 has been used in the radiochemical purity test for the product of Mo-99/ Tc-99m generator. Result from this test was produced directly where the percentage of pertechnetate was calculated based on width peak area by thin layer chromatography. This paperwork will explain the function, procedure, calibration of the instrument and discussed the advantages compared to the previous method. (author)

  17. Kinetics of Hydrogen Radical Reactions with Toluene Including Chemical Activation Theory Employing System-Specific Quantum RRK Theory Calibrated by Variational Transition State Theory.

    Science.gov (United States)

    Bao, Junwei Lucas; Zheng, Jingjing; Truhlar, Donald G

    2016-03-02

    Pressure-dependent reactions are ubiquitous in combustion and atmospheric chemistry. We employ a new calibration procedure for quantum Rice-Ramsperger-Kassel (QRRK) unimolecular rate theory within a chemical activation mechanism to calculate the pressure-falloff effect of a radical association with an aromatic ring. The new theoretical framework is applied to the reaction of H with toluene, which is a prototypical reaction in the combustion chemistry of aromatic hydrocarbons present in most fuels. Both the hydrogen abstraction reactions and the hydrogen addition reactions are calculated. Our system-specific (SS) QRRK approach is adjusted with SS parameters to agree with multistructural canonical variational transition state theory with multidimensional tunneling (MS-CVT/SCT) at the high-pressure limit. The new method avoids the need for the usual empirical estimations of the QRRK parameters, and it eliminates the need for variational transition state theory calculations as a function of energy, although in this first application we do validate the falloff curves by comparing SS-QRRK results without tunneling to multistructural microcanonical variational transition state theory (MS-μVT) rate constants without tunneling. At low temperatures, the two approaches agree well with each other, but at high temperatures, SS-QRRK tends to overestimate falloff slightly. We also show that the variational effect is important in computing the energy-resolved rate constants. Multiple-structure anharmonicity, torsional-potential anharmonicity, and high-frequency-mode vibrational anharmonicity are all included in the rate computations, and torsional anharmonicity effects on the density of states are investigated. Branching fractions, which are both temperature- and pressure-dependent (and for which only limited data is available from experiment), are predicted as a function of pressure.

  18. Risk factors causing evolvement of alimentary-dependent diseases in specific groups of workers employed at metallurgy production and prevention meausres development

    Directory of Open Access Journals (Sweden)

    Yu.V. Danilova

    2017-03-01

    Full Text Available The article gives the results of hygienic and epidemiologic research of morbidity, nutrition structure, food stuffs safety, working conditions, and actual nutrition of workers employed at metallurgy productions. The research was carried out at "Magnitogorskiy metallurgy plant" PLC. 1208 steel workers and founders made up the main group. Average age of research participants amounted to 40.0 ± 0.75. The sampling was representative. We studied actual nutrition over 2010–2015 via analyzing food consumption frequency and applying extended base of food stuffs chemical structure and analyzing menus with lists of dishes offered for an organized group nutrition. We assessed both qualitative and quantitative parameters, including consumption of basic nutrients, energy, irreplaceable amino acids, lipids, vitamins, dietary fiber, essential and conditionally essential microbiological elements (60 nutrients totally, allowing for losses on a product peeling, edible contents, and other losses occurring at various treatments during cooking. We also assessed nutrition regime and other nutrition features. We detected that ratio between proteins, fats and carbohydrates was the evidence of mostly fat nutrition type. Workers were found to consume insufficient quantity of certain vitamins (A, D, and folic acid and biological elements (calcium, but they instead consumed excessive quantities of saturated fats and common salt. It is shown that actual nutrition of specific workers' groups at metallurgy production is not rational, imbalanced, and doesn't satisfy body needs causing risks of nutrition state shifts and alimentary-dependent diseases evolvement. Alimentary-dependent diseases on average amounted to 21.6 % in the total morbidity structure in 2010–2015. 10.0 % of all diseases with temporary working disability are diseases determined by mostly nutrition factor. Epidemiologic analysis of morbidity comprising diseases related to non-rational nutrition enabled us

  19. Neurosurgical operating computerized tomographic scanner system. The CT scanner in the operating theater

    Energy Technology Data Exchange (ETDEWEB)

    Okudera, Hiroshi; Sugita, Kenichiro; Kobayashi, Shigeaki; Kimishima, Sakae; Yoshida, Hisashi

    1988-12-01

    A neurosurgical operating computerized tomography scanner system is presented. This system has been developed for obtaining intra- and postoperative CT images in the operating room. A TCT-300 scanner (manufactured by the Toshiba Co., Tokyo) is placed in the operating room. The realization of a true intraoperative CT image requires certain improvements in the CT scanner and operating table. To adjust the axis of the co-ordinates of the motor system of the MST-7000 microsurgical operating table (manufactured by the Mizuho Ika Co., Tokyo) to the CT scanner, we have designed an interface and a precise motor system so that the computer of the CT scanner can directly control the movement of the operating table. Furthermore, a new head-fixation system has been designed for producing artifact-free intraoperative CT images. The head-pins of the head-fixation system are made of carbon-fiber bars and titanium tips. A simulation study of the total system in the operating room with the CT scanner, operating table, and head holder using a skull model yielded a degree of error similar to that in the phantom testing of the original scanner. Three patients underwent resection of a glial tumor using this system. Intraoperative CT scans taken after dural opening showed a bulging of the cortex, a shift in the central structure, and a displacement of the cortical subarachnoid spaces under the influence of gravity. With a contrast medium the edge of the surrounding brain after resection was enhanced and the residual tumor mass was demonstrated clearly. This system makes it possible to obtain a noninvasive intraoperative image in a situation where structural shifts are taking place.

  20. Laser measuring scanners and their accuracy limits

    Science.gov (United States)

    Jablonski, Ryszard

    1993-09-01

    Scanning methods have gained the greater importance for some years now due to a short measuring time and wide range of application in flexible manufacturing processes. This paper is a summing up of the autho?s creative scientific work in the field of measuring scanners. The research conducted allowed to elaborate the optimal configurations of measuring systems based on the scanning method. An important part of the work was the analysis of a measuring scanner - as a transducer of an angle rotation into the linear displacement which resulted in obtaining its much higher accuracy and finally in working out a measuring scanner eliminating the use of an additional reference standard. The completion of the work is an attempt to determine an attainable accuracy limit of scanning measurement of both length and angle. Using a high stability deflector and a corrected scanning lens one can obtain the angle determination over 30 (or 2 mm) to an accuracy 0 (or 0 tm) when the measuring rate is 1000 Hz or the range d60 (4 mm) with accuracy 0 " (0 jim) and measurement frequency 6 Hz.

  1. The CT scanner as a therapy machine

    International Nuclear Information System (INIS)

    Iwamoto, K.S.; Norman, A.

    1990-01-01

    Many tumors in the brain and in other tissues can be delineated precisely in images obtained with a CT scanner. After the scan is obtained the patient is taken to another room for radiation therapy and is positioned in the beam with the aid of external markers, simulators or stereotactic devices. This procedure is time consuming and subject to error when precise localization of the beam is desired. The CT scanner itself, with the addition of the collimator, is capable of delivering radiation therapy with great precision without the need for external markers. The patient can be scanned and treated on the same table, the isocenter of the beam can be placed precisely in the center of the lesion, the beam can be restricted to just those planes in which the lesion appears, several arcs can be obtained by simply tilting the gantry, and the position of the patient in the beam can be monitored continuously during therapy. The authors describe the properties of the CTX, the CT scanner modified for therapy. (author). 6 refs.; 6 figs

  2. A scanner for single photon emission tomography

    International Nuclear Information System (INIS)

    Smith, D.B.; Cumpstey, D.E.; Evans, N.T.S.; Coleman, J.D.; Ettinger, K.V.; Mallard, J.R.

    1982-01-01

    The technique of single photon ECT has now been available for some eighteen years, but has yet still to be exploited fully. The difficulties of doing this lie in the need for gathering data of sufficiently good statistical accuracy in a reasonable counting time, in the uniformity of detector sensitivity, and in the means for correcting the image satisfactorily for photon attenuation within the body. The relative ease with which a general purpose gamma camera can be adapted to give rotation around the patient makes this an attractive practical approach to the problem. However, the sensitivity of gamma cameras over their field of view is by no means uniform, and their sensitivity is less good than that of purpose-designed scanners when no more than about ten sections through the body are required. There is therefore a need to assess the clinical usefulness of a whole body tomographic scanner of high sensitivity and uniformity. Such a machine is the Aberdeen Section Scanner Mark II described

  3. A near-infrared confocal scanner

    International Nuclear Information System (INIS)

    Lee, Seungwoo; Yoo, Hongki

    2014-01-01

    In the semiconductor industry, manufacturing of three-dimensional (3D) packages or 3D integrated circuits is a high-performance technique that requires combining several functions in a small volume. Through-silicon vias, which are vertical electrical connections extending through a wafer, can be used to direct signals between stacked chips, thus increasing areal density by stacking and connecting multiple patterned chips. While defect detection is essential in the semiconductor manufacturing process, it is difficult to identify defects within a wafer or to monitor the bonding results between bonded surfaces because silicon and many other semiconductor materials are opaque to visible wavelengths. In this context, near-infrared (NIR) imaging is a promising non-destructive method to detect defects within silicon chips, to inspect bonding between chips and to monitor the chip alignment since NIR transmits through silicon. In addition, a confocal scanner provides high-contrast, optically-sectioned images of the specimen due to its ability to reject out-of-focus noise. In this study, we report an NIR confocal scanner that rapidly acquires high-resolution images with a large field of view through silicon. Two orthogonal line-scanning images can be acquired without rotating the system or the specimen by utilizing two orthogonally configured resonant scanning mirrors. This NIR confocal scanner can be efficiently used as an in-line inspection system when manufacturing semiconductor devices by rapidly detecting defects on and beneath the surface. (paper)

  4. Impedance Characterisation of the SPS Wire Scanner

    CERN Document Server

    AUTHOR|(CDS)2091911; Prof. Sillanpää, Mika

    As a beam diagnostic tool, the SPS wire scanner interacts with the proton bunches traversing the vacuum pipes of the Super Proton Synchrotron particle accelerator. Following the interaction, the bunches decelerate or experience momentum kicks off-axis and couple energy to the cavity walls, resonances and to the diagnostic tool, the scanning wire. The beam coupling impedance and, in particular, the beam induced heating of the wire motivate the characterisation and redesign of the SPS wire scanner. In this thesis, we characterise RF-wise the low frequency modes of the SPS wire scanner. These have the highest contribution to the impedance. We measure the cavity modes in terms of resonance frequency and quality factor by traditional measurement techniques and data analysis. We carry out a 4-port measurement to evaluate the beam coupling to the scanning wire, that yields the spectral heating power. If combined with the simulations, one is able to extract the beam coupling impedance and deduce the spectral dissipa...

  5. Scanner-based macroscopic color variation estimation

    Science.gov (United States)

    Kuo, Chunghui; Lai, Di; Zeise, Eric

    2006-01-01

    Flatbed scanners have been adopted successfully in the measurement of microscopic image artifacts, such as granularity and mottle, in print samples because of their capability of providing full color, high resolution images. Accurate macroscopic color measurement relies on the use of colorimeters or spectrophotometers to provide a surrogate for human vision. The very different color response characteristics of flatbed scanners from any standard colorimetric response limits the utility of a flatbed scanner as a macroscopic color measuring device. This metamerism constraint can be significantly relaxed if our objective is mainly to quantify the color variations within a printed page or between pages where a small bias in measured colors can be tolerated as long as the color distributions relative to the individual mean values is similar. Two scenarios when converting color from the device RGB color space to a standardized color space such as CIELab are studied in this paper, blind and semi-blind color transformation, depending on the availability of the black channel information. We will show that both approaches offer satisfactory results in quantifying macroscopic color variation across pages while the semi-blind color transformation further provides fairly accurate color prediction capability.

  6. Particle discrimination by an automatic scanner for nuclear emulsion plates

    International Nuclear Information System (INIS)

    Heinecke, W.; Fischer, B.E.

    1976-01-01

    An automatic scanner for nuclear emulsion plates has been improved by adding particle discrimination. By determination of the mean luminosity of tracks in darkfield illumination in addition to the track length a clear discrimination has been obtained, at least for lighter particles. The scanning speed of the original automatic scanner has not been reduced. The scanner works up to 200 times faster than a human scanner. Besides the particle discrimination the determination of the mean track luminosity led to a lower perturbation sensitivity with respect to a high background of accidentally developed silvergrains, scratches in emulsion etc. The reproducibility of the results obtained by the automatic scanner is better than 5%. (Auth.)

  7. Examining differences in physical activity levels by employment status and/or job activity level: Gender-specific comparisons between the United States and Sweden.

    Science.gov (United States)

    Kwak, Lydia; Berrigan, David; Van Domelen, Dane; Sjöström, Michael; Hagströmer, Maria

    2016-06-01

    The aim of the study was to examine the relationship between employment status and job activity level with physical activity (PA) and sedentary time, stratified by gender and country. Cross-sectional study design. Data from working age adults (18-65 years) from two cross-sectional studies, the Swedish 2001-2002 and 2007-2008 Attitude Behavior and Change Study (ABC; n=1165) and the 2003-2006 US National Health and Nutrition Examination Survey (NHANES; n=4201), were stratified by employment status (employed and not employed) and job activity level (active, sedentary and mixed). PA in counts×min(-1) and time spent in sedentary, low and moderate or higher intensity were measured with accelerometers. Analyses were conducted in 2012-2013. In NHANES, the employed had significantly higher counts×min(-1) and spent more time in moderate or higher intensity PA than those not employed. In ABC, no significant differences were observed between employed and unemployed. Adults with active versus sedentary occupations had higher counts×min(-1) and less sedentary time in both the USA and Sweden and in both men and women. For example, counts×min(-1) were 20-40% greater in active versus sedentary jobs. Employment status is related to PA and sedentary time among men and women in the USA but not in Sweden. Among the employed, occupational PA is associated with total PA and sedentary time for both genders and in both countries. Comparisons of PA levels based on objective measurements can refine understanding of country differences in activity. Copyright © 2015 Sports Medicine Australia. All rights reserved.

  8. Impacts of Intelligent Automated Quality Control on a Small Animal APD-Based Digital PET Scanner

    Science.gov (United States)

    Charest, Jonathan; Beaudoin, Jean-François; Bergeron, Mélanie; Cadorette, Jules; Arpin, Louis; Lecomte, Roger; Brunet, Charles-Antoine; Fontaine, Réjean

    2016-10-01

    Stable system performance is mandatory to warrant the accuracy and reliability of biological results relying on small animal positron emission tomography (PET) imaging studies. This simple requirement sets the ground for imposing routine quality control (QC) procedures to keep PET scanners at a reliable optimal performance level. However, such procedures can become burdensome to implement for scanner operators, especially taking into account the increasing number of data acquisition channels in newer generation PET scanners. In systems using pixel detectors to achieve enhanced spatial resolution and contrast-to-noise ratio (CNR), the QC workload rapidly increases to unmanageable levels due to the number of independent channels involved. An artificial intelligence based QC system, referred to as Scanner Intelligent Diagnosis for Optimal Performance (SIDOP), was proposed to help reducing the QC workload by performing automatic channel fault detection and diagnosis. SIDOP consists of four high-level modules that employ machine learning methods to perform their tasks: Parameter Extraction, Channel Fault Detection, Fault Prioritization, and Fault Diagnosis. Ultimately, SIDOP submits a prioritized faulty channel list to the operator and proposes actions to correct them. To validate that SIDOP can perform QC procedures adequately, it was deployed on a LabPET™ scanner and multiple performance metrics were extracted. After multiple corrections on sub-optimal scanner settings, a 8.5% (with a 95% confidence interval (CI) of [7.6, 9.3]) improvement in the CNR, a 17.0% (CI: [15.3, 18.7]) decrease of the uniformity percentage standard deviation, and a 6.8% gain in global sensitivity were observed. These results confirm that SIDOP can indeed be of assistance in performing QC procedures and restore performance to optimal figures.

  9. AN AUTOMATIC PROCEDURE FOR COMBINING DIGITAL IMAGES AND LASER SCANNER DATA

    Directory of Open Access Journals (Sweden)

    W. Moussa

    2012-07-01

    Full Text Available Besides improving both the geometry and the visual quality of the model, the integration of close-range photogrammetry and terrestrial laser scanning techniques directs at filling gaps in laser scanner point clouds to avoid modeling errors, reconstructing more details in higher resolution and recovering simple structures with less geometric details. Thus, within this paper a flexible approach for the automatic combination of digital images and laser scanner data is presented. Our approach comprises two methods for data fusion. The first method starts by a marker-free registration of digital images based on a point-based environment model (PEM of a scene which stores the 3D laser scanner point clouds associated with intensity and RGB values. The PEM allows the extraction of accurate control information for the direct computation of absolute camera orientations with redundant information by means of accurate space resection methods. In order to use the computed relations between the digital images and the laser scanner data, an extended Helmert (seven-parameter transformation is introduced and its parameters are estimated. Precedent to that, in the second method, the local relative orientation parameters of the camera images are calculated by means of an optimized Structure and Motion (SaM reconstruction method. Then, using the determined transformation parameters results in having absolute oriented images in relation to the laser scanner data. With the resulting absolute orientations we have employed robust dense image reconstruction algorithms to create oriented dense image point clouds, which are automatically combined with the laser scanner data to form a complete detailed representation of a scene. Examples of different data sets are shown and experimental results demonstrate the effectiveness of the presented procedures.

  10. The number and distribution of computerised tomography scanners in Turkey

    International Nuclear Information System (INIS)

    Semin, S.; Amato, Z.

    1999-01-01

    The goal of this study was to investigate the number and distribution of CT scanners in Turkey. Our results show 173 CT scanners in Turkey in 1994, which equals 2.9 scanners per million people. All of the scanners are located in 45 cities, where 81 % of the population resides. The other 31 cities in Turkey have no scanners. Of the 173 scanners, 103 (59.6 %) are owned by the private sector and the other 70 are owned by the public sector. Of Turkey's CT scanners, 49.2 % are located in private health centres, 21.9 % in university hospitals, 16.7 % in Ministry of Health (MOH) hospitals, 10.4 % in private hospitals and 1.8 % in social security hospitals. (orig.)

  11. Daily quality controls analysis of a CT scanner simulator

    International Nuclear Information System (INIS)

    Vasques, Maira Milanelo; Santos, Gabriela R.; Furnari, Laura

    2016-01-01

    With the increasing technological developments, radiotherapy practices, which allow for better involvement of the tumor with the required therapeutic dose and minimize the complications of normal tissues, have become reality in several Radiotherapy services. The use of these resources in turn, was only possible due to the progress made in planning based on digital volumetric images of good quality, such as computed tomography (CT), which allow the correct delimitation of the tumor volume and critical structures. Specific tests for quality control in a CT scanner used in radiotherapy, named CT simulator, should be applied as part of the institutional Quality Assurance Program. This study presents the methodology used in the Instituto de Radiologia do Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo (HCFMUSP) for daily testing of the CT scanner simulator and the results obtained throughout more than two years. The experience gained in the period conducted showed that the tests are easy to perform and can be done in a few minutes by a trained professional. Data analysis showed good reproducibility, which allowed the tests could be performed less frequently, after 16 months of data collection. (author)

  12. Novel design of a parallax free Compton enhanced PET scanner

    International Nuclear Information System (INIS)

    Braem, A.; Chamizo, M.; Chesi, E.; Colonna, N.; Cusanno, F.; De Leo, R.; Garibaldi, F.; Joram, C.; Marrone, S.; Mathot, S.; Nappi, E.; Schoenahl, F.; Seguinot, J.; Weilhammer, P.; Zaidi, H.

    2004-01-01

    Molecular imaging by PET is a powerful tool in modern clinical practice for cancer diagnosis. Nevertheless, improvements are needed with respect to the spatial resolution and sensitivity of the technique for its application to specific human organs (breast, prostate, brain, etc.), and to small animals. Presently, commercial PET scanners do not detect the depth of interaction of photons in scintillators, which results in a not negligible parallax error. We describe here a novel concept of PET scanner design that provides full three-dimensional (3D) gamma reconstruction with high spatial resolution over the total detector volume, free of parallax errors. It uses matrices of long scintillators read at both ends by hybrid photon detectors. This so-called 3D axial concept also enhances the gamma detection efficiency since it allows one to reconstruct a significant fraction of Compton scattered events. In this note, we describe the concept, a possible design and the expected performance of this new PET device. We also report about first characterization measurements of 10 cm long YAP:Ce scintillation crystals

  13. Label-free tissue scanner for colorectal cancer screening

    Science.gov (United States)

    Kandel, Mikhail E.; Sridharan, Shamira; Liang, Jon; Luo, Zelun; Han, Kevin; Macias, Virgilia; Shah, Anish; Patel, Roshan; Tangella, Krishnarao; Kajdacsy-Balla, Andre; Guzman, Grace; Popescu, Gabriel

    2017-06-01

    The current practice of surgical pathology relies on external contrast agents to reveal tissue architecture, which is then qualitatively examined by a trained pathologist. The diagnosis is based on the comparison with standardized empirical, qualitative assessments of limited objectivity. We propose an approach to pathology based on interferometric imaging of "unstained" biopsies, which provides unique capabilities for quantitative diagnosis and automation. We developed a label-free tissue scanner based on "quantitative phase imaging," which maps out optical path length at each point in the field of view and, thus, yields images that are sensitive to the "nanoscale" tissue architecture. Unlike analysis of stained tissue, which is qualitative in nature and affected by color balance, staining strength and imaging conditions, optical path length measurements are intrinsically quantitative, i.e., images can be compared across different instruments and clinical sites. These critical features allow us to automate the diagnosis process. We paired our interferometric optical system with highly parallelized, dedicated software algorithms for data acquisition, allowing us to image at a throughput comparable to that of commercial tissue scanners while maintaining the nanoscale sensitivity to morphology. Based on the measured phase information, we implemented software tools for autofocusing during imaging, as well as image archiving and data access. To illustrate the potential of our technology for large volume pathology screening, we established an "intrinsic marker" for colorectal disease that detects tissue with dysplasia or colorectal cancer and flags specific areas for further examination, potentially improving the efficiency of existing pathology workflows.

  14. Initial clinical test of a breast-PET scanner

    International Nuclear Information System (INIS)

    Raylman, Raymond R.; Koren, Courtney; Schreiman, Judith S.; Majewski, Stan; Marano, Gary D.; Abraham, Jame; Kurian, Sobha; Hazard, Hannah; Filburn, Shannon

    2011-01-01

    The goal of this initial clinical study was to test a new positron emission/tomography imager and biopsy system (PEM/PET) in a small group of selected subjects to assess its clinical imaging capabilities. Specifically, the main task of this study is to determine whether the new system can successfully be used to produce images of known breast cancer and compare them to those acquired by standard techniques. The PEM/PET system consists of two pairs of rotating radiation detectors located beneath a patient table. The scanner has a spatial resolution of ∼2 mm in all three dimensions. The subjects consisted of five patients diagnosed with locally advanced breast cancer ranging in age from 40 to 55 years old scheduled for pre-treatment, conventional whole body PET imaging with F-18 Fluorodeoxyglucose (FDG). The primary lesions were at least 2 cm in diameter. The images from the PEM/PET system demonstrated that this system is capable of identifying some lesions not visible in standard mammograms. Furthermore, while the relatively large lesions imaged in this study where all visualised by a standard whole body PET/CT scanner, some of the morphology of the tumours (ductal infiltration, for example) was better defined with the PEM/PET system. Significantly, these images were obtained immediately following a standard whole body PET scan. The initial testing of the new PEM/PET system demonstrated that the new system is capable of producing good quality breast-PET images compared standard methods.

  15. Employer Branding

    OpenAIRE

    Stroblová, Zuzana

    2017-01-01

    The aim of the Master Thesis is to describe how to build Employer Brand a company. It is based on the description of Employer Branding project of a particular company and the evaluation its process. The thesis is a case study and consists of theoretical and practical part. The theoretical part focuses on trends and changes in leadership approach, definition of Employer Branding and HR Marketing. The practical part deals with the brand building process itself, describes the outputs of the proj...

  16. A combined positron emission tomography (PET)- electron paramagnetic resonance imaging (EPRI) system: initial evaluation of a prototype scanner.

    Science.gov (United States)

    Tseytlin, Mark; Stolin, Alexander V; Guggilapu, Priyaankadevi; Bobko, Andrey A; Khramtsov, Valery V; Tseytlin, Oxana; Raylman, Raymond R

    2018-04-20

    The advent of hybrid scanners, combining complementary modalities, has revolutionized imaging; enhancing clinical practice and biomedical research. In this project, we investigated the melding of two complementary, functional imaging methods: positron emission tomography (PET) and electron paramagnetic resonance imaging (EPRI). The PET radiotracers can provide important information about cellular parameters, such as glucose metabolism. While EPR probes can provide assessment of tissue microenvironment, measuring parameters such as oxygenation and pH, for example. A combined PET/EPRI scanner has the promise to provide new insights not attainable with current imagers by simultaneous acquisition of multiple components of tissue microenvironments. In this investigation, a prototype system was created by combing two existing scanners, modified for simultaneous imaging. Specifically, a silicon photomultiplier (SiPM) based PET scanner ring designed as a portable scanner was combined with an EPRI scanner designed for the imaging of small animals. The ability of the system to obtain simultaneous images was assessed with a small phantom consisting of four cylinders containing both PET and EPR tracers. The resulting images demonstrated the ability to obtain contemporaneous PET and ERP images without cross-modality interference. The next step in this project is the construction of pre-clinical PET/EPRI scanner for multi-parametric assessment of physiologically important parameters of tissue microenvironments. . © 2018 Institute of Physics and Engineering in Medicine.

  17. A combined positron emission tomography (PET)-electron paramagnetic resonance imaging (EPRI) system: initial evaluation of a prototype scanner

    Science.gov (United States)

    Tseytlin, Mark; Stolin, Alexander V.; Guggilapu, Priyaankadevi; Bobko, Andrey A.; Khramtsov, Valery V.; Tseytlin, Oxana; Raylman, Raymond R.

    2018-05-01

    The advent of hybrid scanners, combining complementary modalities, has revolutionized the application of advanced imaging technology to clinical practice and biomedical research. In this project, we investigated the melding of two complementary, functional imaging methods: positron emission tomography (PET) and electron paramagnetic resonance imaging (EPRI). PET radiotracers can provide important information about cellular parameters, such as glucose metabolism. While EPR probes can provide assessment of tissue microenvironment, measuring oxygenation and pH, for example. Therefore, a combined PET/EPRI scanner promises to provide new insights not attainable with current imagers by simultaneous acquisition of multiple components of tissue microenvironments. To explore the simultaneous acquisition of PET and EPR images, a prototype system was created by combining two existing scanners. Specifically, a silicon photomultiplier (SiPM)-based PET scanner ring designed as a portable scanner was combined with an EPRI scanner designed for the imaging of small animals. The ability of the system to obtain simultaneous images was assessed with a small phantom consisting of four cylinders containing both a PET tracer and EPR spin probe. The resulting images demonstrated the ability to obtain contemporaneous PET and EPR images without cross-modality interference. Given the promising results from this initial investigation, the next step in this project is the construction of the next generation pre-clinical PET/EPRI scanner for multi-parametric assessment of physiologically-important parameters of tissue microenvironments.

  18. The simulation of a data acquisition system for a proposed high resolution PET scanner

    Energy Technology Data Exchange (ETDEWEB)

    Rotolo, C.; Larwill, M.; Chappa, S. [Fermi National Accelerator Lab., Batavia, IL (United States); Ordonez, C. [Chicago Univ., IL (United States)

    1993-10-01

    The simulation of a specific data acquisition (DAQ) system architecture for a proposed high resolution Positron Emission Tomography (PET) scanner is discussed. Stochastic processes are used extensively to model PET scanner signal timing and probable DAQ circuit limitations. Certain architectural parameters, along with stochastic parameters, are varied to quantatively study the resulting output under various conditions. The inclusion of the DAQ in the model represents a novel method of more complete simulations of tomograph designs, and could prove to be of pivotal importance in the optimization of such designs.

  19. The simulation of a data acquisition system for a proposed high resolution PET scanner

    International Nuclear Information System (INIS)

    Rotolo, C.; Larwill, M.; Chappa, S.; Ordonez, C.

    1993-10-01

    The simulation of a specific data acquisition (DAQ) system architecture for a proposed high resolution Positron Emission Tomography (PET) scanner is discussed. Stochastic processes are used extensively to model PET scanner signal timing and probable DAQ circuit limitations. Certain architectural parameters, along with stochastic parameters, are varied to quantatively study the resulting output under various conditions. The inclusion of the DAQ in the model represents a novel method of more complete simulations of tomograph designs, and could prove to be of pivotal importance in the optimization of such designs

  20. Risks of exposure to ionizing and millimeter-wave radiation from airport whole-body scanners.

    Science.gov (United States)

    Moulder, John E

    2012-06-01

    Considerable public concern has been expressed around the world about the radiation risks posed by the backscatter (ionizing radiation) and millimeter-wave (nonionizing radiation) whole-body scanners that have been deployed at many airports. The backscatter and millimeter-wave scanners currently deployed in the U.S. almost certainly pose negligible radiation risks if used as intended, but their safety is difficult-to-impossible to prove using publicly accessible data. The scanners are widely disliked and often feared, which is a problem made worse by what appears to be a veil of secrecy that covers their specifications and dosimetry. Therefore, for these and future similar technologies to gain wide acceptance, more openness is needed, as is independent review and regulation. Publicly accessible, and preferably peer-reviewed evidence is needed that the deployed units (not just the prototypes) meet widely-accepted safety standards. It is also critical that risk-perception issues be handled more competently.

  1. Employer Toolkit.

    Science.gov (United States)

    Thuli, Kelli J.; Hong, Esther

    This document consists of two guides intended for either employers or service providers involved in school to work partnerships for students with disabilities. "Tools for Service Providers" is intended to be used for training local-level providers who are developing school to work linkages with employers. Following an introduction, this…

  2. Recent micro-CT scanner developments at UGCT

    Energy Technology Data Exchange (ETDEWEB)

    Dierick, Manuel, E-mail: Manuel.Dierick@UGent.be [UGCT-Department of Physics and Astronomy, Faculty of Sciences, Ghent University, Proeftuinstraat 86, 9000 Ghent (Belgium); XRE, X-Ray Engineering bvba, De Pintelaan 111, 9000 Ghent (Belgium); Van Loo, Denis, E-mail: info@XRE.be [XRE, X-Ray Engineering bvba, De Pintelaan 111, 9000 Ghent (Belgium); Masschaele, Bert [UGCT-Department of Physics and Astronomy, Faculty of Sciences, Ghent University, Proeftuinstraat 86, 9000 Ghent (Belgium); XRE, X-Ray Engineering bvba, De Pintelaan 111, 9000 Ghent (Belgium); Van den Bulcke, Jan [UGCT-Woodlab-UGent, Department of Forest and Water Management, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent (Belgium); Van Acker, Joris, E-mail: Joris.VanAcker@UGent.be [UGCT-Woodlab-UGent, Department of Forest and Water Management, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent (Belgium); Cnudde, Veerle, E-mail: Veerle.Cnudde@UGent.be [UGCT-SGIG, Department of Geology and Soil Science, Faculty of Sciences, Ghent University, Krijgslaan 281, S8, 9000 Ghent (Belgium); Van Hoorebeke, Luc, E-mail: Luc.VanHoorebeke@UGent.be [UGCT-Department of Physics and Astronomy, Faculty of Sciences, Ghent University, Proeftuinstraat 86, 9000 Ghent (Belgium)

    2014-04-01

    This paper describes two X-ray micro-CT scanners which were recently developed to extend the experimental possibilities of microtomography research at the Centre for X-ray Tomography ( (www.ugct.ugent.be)) of the Ghent University (Belgium). The first scanner, called Nanowood, is a wide-range CT scanner with two X-ray sources (160 kV{sub max}) and two detectors, resolving features down to 0.4 μm in small samples, but allowing samples up to 35 cm to be scanned. This is a sample size range of 3 orders of magnitude, making this scanner well suited for imaging multi-scale materials such as wood, stone, etc. Besides the traditional cone-beam acquisition, Nanowood supports helical acquisition, and it can generate images with significant phase-contrast contributions. The second scanner, known as the Environmental micro-CT scanner (EMCT), is a gantry based micro-CT scanner with variable magnification for scanning objects which are not easy to rotate in a standard micro-CT scanner, for example because they are physically connected to external experimental hardware such as sensor wiring, tubing or others. This scanner resolves 5 μm features, covers a field-of-view of about 12 cm wide with an 80 cm vertical travel range. Both scanners will be extensively described and characterized, and their potential will be demonstrated with some key application results.

  3. Recent micro-CT scanner developments at UGCT

    International Nuclear Information System (INIS)

    Dierick, Manuel; Van Loo, Denis; Masschaele, Bert; Van den Bulcke, Jan; Van Acker, Joris; Cnudde, Veerle; Van Hoorebeke, Luc

    2014-01-01

    This paper describes two X-ray micro-CT scanners which were recently developed to extend the experimental possibilities of microtomography research at the Centre for X-ray Tomography ( (www.ugct.ugent.be)) of the Ghent University (Belgium). The first scanner, called Nanowood, is a wide-range CT scanner with two X-ray sources (160 kV max ) and two detectors, resolving features down to 0.4 μm in small samples, but allowing samples up to 35 cm to be scanned. This is a sample size range of 3 orders of magnitude, making this scanner well suited for imaging multi-scale materials such as wood, stone, etc. Besides the traditional cone-beam acquisition, Nanowood supports helical acquisition, and it can generate images with significant phase-contrast contributions. The second scanner, known as the Environmental micro-CT scanner (EMCT), is a gantry based micro-CT scanner with variable magnification for scanning objects which are not easy to rotate in a standard micro-CT scanner, for example because they are physically connected to external experimental hardware such as sensor wiring, tubing or others. This scanner resolves 5 μm features, covers a field-of-view of about 12 cm wide with an 80 cm vertical travel range. Both scanners will be extensively described and characterized, and their potential will be demonstrated with some key application results

  4. Recent advances in segmented gamma scanner analysis

    International Nuclear Information System (INIS)

    Sprinkle, J.K. Jr.; Hsue, S.T.

    1987-01-01

    The segmented gamma scanner (SGS) is used in many facilities to assay low-density scrap and waste generated in the facilities. The procedures for using the SGS can cause a negative bias if the sample does not satisfy the assumptions made in the method. Some process samples do not comply with the assumptions. This paper discusses the effect of the presence of lumps on the SGS assay results, describes a method to detect the presence of lumps, and describes an approach to correct for the lumps. Other recent advances in SGS analysis are also discussed

  5. Fast wire scanner for intense electron beams

    Directory of Open Access Journals (Sweden)

    T. Moore

    2014-02-01

    Full Text Available We have developed a cost-effective, fast rotating wire scanner for use in accelerators where high beam currents would otherwise melt even carbon wires. This new design uses a simple planetary gear setup to rotate a carbon wire, fixed at one end, through the beam at speeds in excess of 20  m/s. We present results from bench tests, as well as transverse beam profile measurements taken at Cornell’s high-brightness energy recovery linac photoinjector, for beam currents up to 35 mA.

  6. Characterization of radiochromic films EBT3 by means of the scanner Vidar dosimetry Pro Red and Epson 10000-XL use; Caracterizacion de films radiocromicos EBT3 mediante el uso de scanner Vidar dosimetry Pro Red y Epson 10000-XL

    Energy Technology Data Exchange (ETDEWEB)

    Medina, L.; Garrigo, E.; Venencia, D.; Adrada, A.; Filipuzzi, M., E-mail: fisicamedina11@gmail.com [Instituto Privado de Radioterapia, Obispo Oro 423, X5000BFI Cordoba (Argentina)

    2014-08-15

    The Radiochromic film have become an attractive tool for verification of dose distributions in IMRT because these have high spatial resolution film, are near water equivalent and not require revealed, A critical aspect of the use of these film is used for digitizing scanner The purpose of this paper is to characterize EBT3 using two types of scanner. Were employed The Radiochromic film EBT3, was used photon beam 6 MV generated by a linear accelerator Siemens Primus, he films were irradiated at a dose range between 0 Gy a 9 Gy. The stabilization time after irradiation was 24 hours. The films were digitized with a scanner Epson 10000-XL y el VIDAR Dosimetry Pro Red. We used the software for construction of the calibration curve. The resolution of each dosimetry system was analyzed through the results of the spatial response function by analyzing a step pattern. The Epson scanner is most sensitive to the red channel. This is less than that obtained with the Vidar. The Vidar scanner spatial response profiles disturbs not opposed to Epson analyzed. The calibration curves for both dosimetry systems can be employed. However, the sensitivity and repeatability of the system is better than Red Vidar Epson 10000-XL. (author)

  7. Circumference estimation using 3D-whole body scanners and shadow scanner

    NARCIS (Netherlands)

    Daanen, H.A.M.

    1998-01-01

    Clothing designers and manufacturers use traditional body dimensions as their basis. When 3D-whole body scanners are introduced to determine the body dimensions, a conversion has to be made, since scan determined circumference measures are slightly larger than the traditional values. This pilot

  8. Characterization of radiochromic films EBT3 by means of the scanner Vidar dosimetry Pro Red and Epson 10000-XL use

    International Nuclear Information System (INIS)

    Medina, L.; Garrigo, E.; Venencia, D.; Adrada, A.; Filipuzzi, M.

    2014-08-01

    The Radiochromic film have become an attractive tool for verification of dose distributions in IMRT because these have high spatial resolution film, are near water equivalent and not require revealed, A critical aspect of the use of these film is used for digitizing scanner The purpose of this paper is to characterize EBT3 using two types of scanner. Were employed The Radiochromic film EBT3, was used photon beam 6 MV generated by a linear accelerator Siemens Primus, he films were irradiated at a dose range between 0 Gy a 9 Gy. The stabilization time after irradiation was 24 hours. The films were digitized with a scanner Epson 10000-XL y el VIDAR Dosimetry Pro Red. We used the software for construction of the calibration curve. The resolution of each dosimetry system was analyzed through the results of the spatial response function by analyzing a step pattern. The Epson scanner is most sensitive to the red channel. This is less than that obtained with the Vidar. The Vidar scanner spatial response profiles disturbs not opposed to Epson analyzed. The calibration curves for both dosimetry systems can be employed. However, the sensitivity and repeatability of the system is better than Red Vidar Epson 10000-XL. (author)

  9. 3D Laser Scanner for Underwater Manipulation

    Directory of Open Access Journals (Sweden)

    Albert Palomer

    2018-04-01

    Full Text Available Nowadays, research in autonomous underwater manipulation has demonstrated simple applications like picking an object from the sea floor, turning a valve or plugging and unplugging a connector. These are fairly simple tasks compared with those already demonstrated by the mobile robotics community, which include, among others, safe arm motion within areas populated with a priori unknown obstacles or the recognition and location of objects based on their 3D model to grasp them. Kinect-like 3D sensors have contributed significantly to the advance of mobile manipulation providing 3D sensing capabilities in real-time at low cost. Unfortunately, the underwater robotics community is lacking a 3D sensor with similar capabilities to provide rich 3D information of the work space. In this paper, we present a new underwater 3D laser scanner and demonstrate its capabilities for underwater manipulation. In order to use this sensor in conjunction with manipulators, a calibration method to find the relative position between the manipulator and the 3D laser scanner is presented. Then, two different advanced underwater manipulation tasks beyond the state of the art are demonstrated using two different manipulation systems. First, an eight Degrees of Freedom (DoF fixed-base manipulator system is used to demonstrate arm motion within a work space populated with a priori unknown fixed obstacles. Next, an eight DoF free floating Underwater Vehicle-Manipulator System (UVMS is used to autonomously grasp an object from the bottom of a water tank.

  10. High-picture quality industrial CT scanner

    International Nuclear Information System (INIS)

    Shoji, Takao; Nishide, Akihiko; Fujii, Masashi.

    1989-01-01

    Industrial X-ray-CT-scanners, which provide cross-sectional images of a tested sample without destroying it, are attracting attention as a new nondestructive inspection device. In 1982, Toshiba commenced the development of industrial CT scanners, and introduced the 'TOSCANER' -3000 and-4000 series. Now, the state of the art 'TOSCANER'-20000 series of CT systems has been developed incorporating the latest computer tomography and image processing technology, such as the T9506 image processor. One of the advantages of this system is its applicability to a wide range of X-ray energy . The 'TOSCANER'-20000 series can be utilized for inspecting castings and other materials with relatively low-transparency to X-rays, as well as ceramics, composite materials and other materials with high X-ray transparency. A further feature of the new system is its high-picture quality, with a high-spatial resolution resulting from a pixel size of 0.2x0.2(mm). (author)

  11. 3D Laser Scanner for Underwater Manipulation.

    Science.gov (United States)

    Palomer, Albert; Ridao, Pere; Youakim, Dina; Ribas, David; Forest, Josep; Petillot, Yvan

    2018-04-04

    Nowadays, research in autonomous underwater manipulation has demonstrated simple applications like picking an object from the sea floor, turning a valve or plugging and unplugging a connector. These are fairly simple tasks compared with those already demonstrated by the mobile robotics community, which include, among others, safe arm motion within areas populated with a priori unknown obstacles or the recognition and location of objects based on their 3D model to grasp them. Kinect-like 3D sensors have contributed significantly to the advance of mobile manipulation providing 3D sensing capabilities in real-time at low cost. Unfortunately, the underwater robotics community is lacking a 3D sensor with similar capabilities to provide rich 3D information of the work space. In this paper, we present a new underwater 3D laser scanner and demonstrate its capabilities for underwater manipulation. In order to use this sensor in conjunction with manipulators, a calibration method to find the relative position between the manipulator and the 3D laser scanner is presented. Then, two different advanced underwater manipulation tasks beyond the state of the art are demonstrated using two different manipulation systems. First, an eight Degrees of Freedom (DoF) fixed-base manipulator system is used to demonstrate arm motion within a work space populated with a priori unknown fixed obstacles. Next, an eight DoF free floating Underwater Vehicle-Manipulator System (UVMS) is used to autonomously grasp an object from the bottom of a water tank.

  12. Interferometric Laser Scanner for Direction Determination

    Directory of Open Access Journals (Sweden)

    Gennady Kaloshin

    2016-01-01

    Full Text Available In this paper, we explore the potential capabilities of new laser scanning-based method for direction determination. The method for fully coherent beams is extended to the case when interference pattern is produced in the turbulent atmosphere by two partially coherent sources. The performed theoretical analysis identified the conditions under which stable pattern may form on extended paths of 0.5–10 km in length. We describe a method for selecting laser scanner parameters, ensuring the necessary operability range in the atmosphere for any possible turbulence characteristics. The method is based on analysis of the mean intensity of interference pattern, formed by two partially coherent sources of optical radiation. Visibility of interference pattern is estimated as a function of propagation pathlength, structure parameter of atmospheric turbulence, and spacing of radiation sources, producing the interference pattern. It is shown that, when atmospheric turbulences are moderately strong, the contrast of interference pattern of laser scanner may ensure its applicability at ranges up to 10 km.

  13. A 3D airborne ultrasound scanner

    Science.gov (United States)

    Capineri, L.; Masotti, L.; Rocchi, S.

    1998-06-01

    This work investigates the feasibility of an ultrasound scanner designed to reconstruct three-dimensional profiles of objects in air. There are many industrial applications in which it is important to obtain quickly and accurately the digital reconstruction of solid objects with contactless methods. The final aim of this project was the profile reconstruction of shoe lasts in order to eliminate the mechanical tracers from the reproduction process of shoe prototypes. The feasibility of an ultrasonic scanner was investigated in laboratory conditions on wooden test objects with axial symmetry. A bistatic system based on five airborne polyvinylidenedifluoride (PVDF) transducers was mechanically moved to emulate a cylindrical array transducer that can host objects of maximum width and height 20 cm and 40 cm respectively. The object reconstruction was based on a simplified version of the synthetic aperture focusing technique (SAFT): the time of flight (TOF) of the first in time echo for each receiving transducer was taken into account, a coarse spatial sampling of the ultrasonic field reflected on the array transducer was delivered and the reconstruction algorithm was based on the ellipsoidal backprojection. Measurements on a wooden cone section provided submillimetre accuracy in a controlled environment.

  14. Interferometric Laser Scanner for Direction Determination

    Science.gov (United States)

    Kaloshin, Gennady; Lukin, Igor

    2016-01-01

    In this paper, we explore the potential capabilities of new laser scanning-based method for direction determination. The method for fully coherent beams is extended to the case when interference pattern is produced in the turbulent atmosphere by two partially coherent sources. The performed theoretical analysis identified the conditions under which stable pattern may form on extended paths of 0.5–10 km in length. We describe a method for selecting laser scanner parameters, ensuring the necessary operability range in the atmosphere for any possible turbulence characteristics. The method is based on analysis of the mean intensity of interference pattern, formed by two partially coherent sources of optical radiation. Visibility of interference pattern is estimated as a function of propagation pathlength, structure parameter of atmospheric turbulence, and spacing of radiation sources, producing the interference pattern. It is shown that, when atmospheric turbulences are moderately strong, the contrast of interference pattern of laser scanner may ensure its applicability at ranges up to 10 km. PMID:26805841

  15. Health physics aspects of the EMI computerized tomography brain scanner

    International Nuclear Information System (INIS)

    Villafana, T.; Scouras, J.; Kirkland, L.; McElroy, N.; Paras, P.

    1978-01-01

    The EMI computerized tomographic cranial scanner is one of the first radiological systems incorporating an on-line computer. The result is an increase in the ability to visualize such tissues as grey matter and white matter as well as blood pools and tumor volumes. This advance has already begun to revolutionize radiological practice. Because of the totally different configuration of this unit, concern has been expressed over the dosages received by the patient, consequently the health physics aspects of this unit have been studied. Specifically, doses received by the surface of head and interior brain points as well as by the lens of the eye and gonads are reported here. X-ray output, beam half-value layers and barrier shielding requirements are also reported and discussed. (author)

  16. MFP scanner diagnostics using a self-printed target to measure the modulation transfer function

    Science.gov (United States)

    Wang, Weibao; Bauer, Peter; Wagner, Jerry; Allebach, Jan P.

    2014-01-01

    In the current market, reduction of warranty costs is an important avenue for improving profitability by manufacturers of printer products. Our goal is to develop an autonomous capability for diagnosis of printer and scanner caused defects with mid-range laser multifunction printers (MFPs), so as to reduce warranty costs. If the scanner unit of the MFP is not performing according to specification, this issue needs to be diagnosed. If there is a print quality issue, this can be diagnosed by printing a special test page that is resident in the firmware of the MFP unit, and then scanning it. However, the reliability of this process will be compromised if the scanner unit is defective. Thus, for both scanner and printer image quality issues, it is important to be able to properly evaluate the scanner performance. In this paper, we consider evaluation of the scanner performance by measuring its modulation transfer function (MTF). The MTF is a fundamental tool for assessing the performance of imaging systems. Several ways have been proposed to measure the MTF, all of which require a special target, for example a slanted-edge target. It is unacceptably expensive to ship every MFP with such a standard target, and to expect that the customer can keep track of it. To reduce this cost, in this paper, we develop new approach to this task. It is based on a self-printed slanted-edge target. Then, we propose algorithms to improve the results using a self-printed slanted-edge target. Finally, we present experimental results for MTF measurement using self-printed targets and compare them to the results obtained with standard targets.

  17. Puebla Territory-Specific Basket of Goods Strategies and Their Local Repercussions for Employment and Profit: the Case of Xicotepec de Juárez, Puebla

    Directory of Open Access Journals (Sweden)

    Mario del Roble Pensado Leglise

    2015-07-01

    Full Text Available Developing a basket of land goods means a systemic strateg y for small farmers because it allows reaching multiple objectives in order to promote territorial competitiveness to access market niches with varied rural goods, strengthen social capital and generate better local levels in employment and income, together with increasing and preserving the environment. This analysis implied the application of a system dynamics model which produced possible future scenarios (through Ve n s i m®DSS 5.8 about employment and income obtained by smallholder coffee farmers from Xicotepec de Juárez municipality in Puebla, regarding the setting of the above mentioned strateg y for rural development. Results showed that this strateg y was implemented successfully and also revealed opportunities for: a improving the development capacity of small farmers; b making the institutional context favorable; c The reinforcement of social capital essential to implement this land strategy.

  18. Was the Scanner Calibration Slide used for its intended purpose?

    Directory of Open Access Journals (Sweden)

    Zong Yaping

    2011-04-01

    Full Text Available Abstract In the article, Scanner calibration revisited, BMC Bioinformatics 2010, 11:361, Dr. Pozhitkov used the Scanner Calibration Slide, a key product of Full Moon BioSystems to generate data in his study of microarray scanner PMT response and proposed a mathematic model for PMT response 1. In the end, the author concluded that "Full Moon BioSystems calibration slides are inadequate for performing calibration," and recommended "against using these slides." We found these conclusions are seriously flawed and misleading, and his recommendation against using the Scanner Calibration Slide was not properly supported.

  19. SCT-4800T whole body X-ray CT scanner

    International Nuclear Information System (INIS)

    Okumura, Yoshitaka; Sato, Yukio; Kuwahara, Hiroshi

    1994-01-01

    A whole body X-ray CT scanner, the SCT-4800T (trade name: INTELLECT series), has been developed. This system is the first CT scanner that is combined with general radiographic functions. The general radiographic functions include a patient couch with film casette and several tube support systems along with the CT scanner. This newly designed CT scanner also features a compact and light-weight gantry with a 700 mm diameter apperture and user-friendly operater's console. The SCT-4800T brings a new level of patient and operator comfort to the emergency radiology examination site. (author)

  20. Input Scanners: A Growing Impact In A Diverse Marketplace

    Science.gov (United States)

    Marks, Kevin E.

    1989-08-01

    Just as newly invented photographic processes revolutionized the printing industry at the turn of the century, electronic imaging has affected almost every computer application today. To completely emulate traditionally mechanical means of information handling, computer based systems must be able to capture graphic images. Thus, there is a widespread need for the electronic camera, the digitizer, the input scanner. This paper will review how various types of input scanners are being used in many diverse applications. The following topics will be covered: - Historical overview of input scanners - New applications for scanners - Impact of scanning technology on select markets - Scanning systems issues

  1. Employer Branding

    DEFF Research Database (Denmark)

    Frimann, Søren; Mønsted, Bolette Rye

    2012-01-01

    Employer branding er både for den private og den offentlige sektor blevet en måde, de kan imødekomme ændrede arbejdsmarkedsvilkår og organisatoriske udfordringer i en postmoderne og globaliseret verden. Den aktuelle finanskrise har skabt nye udfordringer for organisationer i deres bestræbelser på...... at tiltrække- og fastholde attraktive medarbejdere. Men hvilken betydning har det, når Grundfos siger ”Mennesket er i fokus”, og hvad siger ”mangfoldighed” om Københavns Kommune som arbejdsplads i relation til employer branding? Er der egentlig sammenhæng mellem tankerne bag employer branding og de eksternt...... kommunikerede employer brandprodukter. Eller bliver det unikke ved arbejdspladserne ersattet af buzzwords uden substans og inddragelse af ansatte og interessenter? Artiklen har til formål at vurdere disse spørgsmål på baggrund af analyser af to cases med employer branding....

  2. [The comparative assessment of the practical value of the currently employed methods for the recognition and species specificity of the blood].

    Science.gov (United States)

    Grezina, N Iu; Suleĭmenova, G M

    2011-01-01

    The objective of the present study was to evaluate sensitivity and specificity of the HemDirect method on test-plates (Seratec) for detecting human hemoglobin (HHb). These characteristics were compared with those of other widely used methods designed for the detection of blood traces, viz. thin layer chromatography, hemotest, spectrofluorimetry, and identification of blood species specificity (by countercurrent immunoelectrophoresis in agar and on the acetate-cellulose film). It was shown that the HemDirect test is highly specific and far more sensitive than other techniques used for the same purpose in the practical work. It can be recommended as the method of choice for the detection of blood microtraces.

  3. Student employment

    DEFF Research Database (Denmark)

    Jacob, Marita; Gerth, Maria; Weiss, Felix

    2018-01-01

    , according to social origins, in student employment from first-year students through graduating students. We show that inequality in job quality exists and is partly attributable to the need for students from lower social origins to work to finance their studies. We hypothesise that initial inequalities......In this article, we examine social origin differences in employment patterns across different stages of higher education and compare these differences between vocational and academic fields of study. Using data from a large-scale German student survey, we study the development of inequality...

  4. Maternal Employment in Norway A parity-specific analysis of the return to full-time and part-time work after birth

    OpenAIRE

    Marit Rønsen

    1995-01-01

    This paper analyzes the (re)entry of Norwegian mothers into full-time and part-time employment following the first and second birth. Based on theories of job search and human capital depreciation and appreciation a semi-parametric hazard model is estimated, expressing the entry rate as a function of a woman's full wage (the market wage plus the present value of reductions in future earnings due to a career break) and her reservation wage. As predicted, a higher market wage and higher accumula...

  5. Computerized tomographic scanner with shaped radiation filter

    International Nuclear Information System (INIS)

    Carlson, R.W.; Walters, R.G.

    1981-01-01

    The invention comprises a shaped filter and a filter correction circuitry for computerized tomographic scanners. The shaped filter is a generally u-shaped block of filter material which is adapted to be mounted between the source of radiation and the scan circle. The u-shaped block has a parabolic recess. The filter material may be beryllium, aluminum, sulphur, calcium, titanium, erbium, copper, and compounds including oxides and alloys thereof. The filter correction circuit comprises a first filter correction profile adding circuit for adding a first scaler valve to each intensity valve in a data line. The data line is operated on by a beam hardness correction polynomial. After the beam hardness polynomial correction operation, a second filter correction circuit adds a second filter correction profile consisting of a table of scalor values, one corresponding to each intensity reading in the data line

  6. Development of scintillation materials for PET scanners

    CERN Document Server

    Korzhik, Mikhail; Annenkov, Alexander N; Borissevitch, Andrei; Dossovitski, Alexei; Missevitch, Oleg; Lecoq, Paul

    2007-01-01

    The growing demand on PET methodology for a variety of applications ranging from clinical use to fundamental studies triggers research and development of PET scanners providing better spatial resolution and sensitivity. These efforts are primarily focused on the development of advanced PET detector solutions and on the developments of new scintillation materials as well. However Lu containing scintillation materials introduced in the last century such as LSO, LYSO, LuAP, LuYAP crystals still remain the best PET species in spite of the recent developments of bright, fast but relatively low density lanthanum bromide scintillators. At the same time Lu based materials have several drawbacks which are high temperature of crystallization and relatively high cost compared to alkali-halide scintillation materials. Here we describe recent results in the development of new scintillation materials for PET application.

  7. Compact beamforming in medical ultrasound scanners

    DEFF Research Database (Denmark)

    Tomov, Borislav Gueorguiev

    2003-01-01

    for high-quality imaging is large, and compressing it leads to better compactness of the beamformers. The existing methods for compressing and recursive generation of focusing data, along with original work in the area, are presented in Chapter 4. The principles and the performance limitations...... quality is comparable to that of the very good scanners currently on the market. The performance results have been achieved with the use of a simple oversampled converter of second order. The use of a higher order oversampled converter will allow higher pulse frequency to be used while the high dynamic...... channels, and even more channels are necessary for 3-dimensional (3D) diagnostic imaging. On the other hand, there is a demand for inexpensive portable devices for use outside hospitals, in field conditions, where power consumption and compactness are important factors. The thesis starts...

  8. Upgraded airborne scanner for commercial remote sensing

    Science.gov (United States)

    Chang, Sheng-Huei; Rubin, Tod D.

    1994-06-01

    Traditional commercial remote sensing has focused on the geologic market, with primary focus on mineral identification and mapping in the visible through short-wave infrared spectral regions (0.4 to 2.4 microns). Commercial remote sensing users now demand airborne scanning capabilities spanning the entire wavelength range from ultraviolet through thermal infrared (0.3 to 12 microns). This spectral range enables detection, identification, and mapping of objects and liquids on the earth's surface and gases in the air. Applications requiring this range of wavelengths include detection and mapping of oil spills, soil and water contamination, stressed vegetation, and renewable and non-renewable natural resources, and also change detection, natural hazard mitigation, emergency response, agricultural management, and urban planning. GER has designed and built a configurable scanner that acquires high resolution images in 63 selected wave bands in this broad wavelength range.

  9. A clinical molecular scanner: the Melanie project.

    Science.gov (United States)

    Hochstrasser, D F; Appel, R D; Vargas, R; Perrier, R; Vurlod, J F; Ravier, F; Pasquali, C; Funk, M; Pellegrini, C; Muller, A F

    1991-01-01

    We developed an expert system to analyze and interpret protein maps. This system, Melanie (medical electrophoresis analysis interactive expert), can distinguish between normal and cirrhotic liver and identify various types of cancer on the basis of protein patterns in biopsy specimens. Our findings suggest that some diseases associated with toxic compounds or modifications of the human genome can be diagnosed by expert systems that analyze protein maps. The combination of protein mapping and computer analysis could result in a clinically useful "molecular scanner". The massive amount of information analyzed and stored in such studies requires new strategies, including centralized databases and image transmission over networks. Increased understanding of protein expression and regulation will enhance the importance of the human genome project in medicine and biology.

  10. Software development for modeling positrons emission tomograph scanners

    International Nuclear Information System (INIS)

    Vieira, Igor Fagner

    2013-01-01

    The Geant4 Application for Tomographic Emission (GATE) is an international platform recognized and used to develop Computational Model Exposure (CME) in the context of Nuclear Medicine, although currently there are dedicated modules for applications in Radiotherapy and Computed Tomography (CT). GATE uses Monte Carlo (MC) methods, and has a scripting language of its own. The writing of scripts for simulation of a PET scanner in GATE involves a number of interrelated steps, and the accuracy of the simulation is dependent on the correct setup of the geometries involved, since the physical processes depend on them, as well as the modeling of electronic detectors in module Digitizer, for example. The manual implementation of this setup can be a source of errors, especially for users without experience in the field of simulations or without any previous knowledge of a programming language, and also due to the the fact that the modeling process in GATE still remains bounded to LINUX / UNIX based systems, an environment only familiar to a few. This becomes an obstacle for beginners and prevents the use of GATE by a larger number of users interested in optimizing their experiments and/or clinical protocols through a more accessible, fast and friendly application. The objective of this work is therefore to develop a user-friendly software for the modeling of Positron Emission Tomography called GUIGATE (Graphical User Interface for GATE), with specific modules dedicated to quality control in PET scanners. The results exhibit the features available in this first version of GUIGATE, present in a set of windows that allow users to create their input files, perform and display in real time the model and analyze its output file in a single environment, allowing so intuitively access the entire architecture of the GATE simulation and to CERN's data analyzer, the ROOT. (author)

  11. Performance of an automatic dose control system for CT. Specifications and basic phantom tests

    Energy Technology Data Exchange (ETDEWEB)

    Nagel, H.D. [Wissenschaft und Technik fuer die Radiolgoe, Dr. HD Nagel, Buchholz (Germany); Stumpp, P.; Kahn, T.; Gosch, D. [Universitaetsklinikum Leipzig (Germany). Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie

    2011-01-15

    Purpose: To assess the performance and to provide more detailed insight into the characteristics and limitations of devices for automatic dose control (ADC) in CT. Materials and Methods: A comprehensive study on DoseRight 2.0, the ADC system provided by Philips for its Brilliance CT scanners, was conducted. Phantom tests were carried out on a 64-slice scanner (Brilliance 64) using assorted quality control (QC) phantoms that allowed verification of the basic specifications. If feasible, the findings were verified by model calculations based on known specifications. Results: For all tests, the dose reductions and modulation characteristics fully met the values expected from the specifications. Adverse effects due to increased image noise were only moderate as a result of the 'adequate noise system' design that employs comparatively gentle modulation, and the additional use of adaptive filtration. Conclusion: Simple tests with QC phantoms allow evaluation of the most relevant characteristics of devices for ADC in CT. (orig.)

  12. A Hybrid Soft-computing Method for Image Analysis of Digital Plantar Scanners

    Science.gov (United States)

    Razjouyan, Javad; Khayat, Omid; Siahi, Mehdi; Mansouri, Ali Alizadeh

    2013-01-01

    Digital foot scanners have been developed in recent years to yield anthropometrists digital image of insole with pressure distribution and anthropometric information. In this paper, a hybrid algorithm containing gray level spatial correlation (GLSC) histogram and Shanbag entropy is presented for analysis of scanned foot images. An evolutionary algorithm is also employed to find the optimum parameters of GLSC and transform function of the membership values. Resulting binary images as the thresholded images are undergone anthropometric measurements taking in to account the scale factor of pixel size to metric scale. The proposed method is finally applied to plantar images obtained through scanning feet of randomly selected subjects by a foot scanner system as our experimental setup described in the paper. Running computation time and the effects of GLSC parameters are investigated in the simulation results. PMID:24083133

  13. A Hybrid Soft-computing Method for Image Analysis of Digital Plantar Scanners.

    Science.gov (United States)

    Razjouyan, Javad; Khayat, Omid; Siahi, Mehdi; Mansouri, Ali Alizadeh

    2013-01-01

    Digital foot scanners have been developed in recent years to yield anthropometrists digital image of insole with pressure distribution and anthropometric information. In this paper, a hybrid algorithm containing gray level spatial correlation (GLSC) histogram and Shanbag entropy is presented for analysis of scanned foot images. An evolutionary algorithm is also employed to find the optimum parameters of GLSC and transform function of the membership values. Resulting binary images as the thresholded images are undergone anthropometric measurements taking in to account the scale factor of pixel size to metric scale. The proposed method is finally applied to plantar images obtained through scanning feet of randomly selected subjects by a foot scanner system as our experimental setup described in the paper. Running computation time and the effects of GLSC parameters are investigated in the simulation results.

  14. Using mid-range laser scanners to digitize cultural-heritage sites.

    Science.gov (United States)

    Spring, Adam P; Peters, Caradoc; Minns, Tom

    2010-01-01

    Here, we explore new, more accessible ways of modeling 3D data sets that both professionals and amateurs can employ in areas such as architecture, forensics, geotechnics, cultural heritage, and even hobbyist modeling. To support our arguments, we present images from a recent case study in digital preservation of cultural heritage using a mid-range laser scanner. Our appreciation of the increasing variety of methods for capturing 3D spatial data inspired our research. Available methods include photogrammetry, airborne lidar, sonar, total stations (a combined electronic and optical survey instrument), and midand close-range scanning.1 They all can produce point clouds of varying density. In our case study, the point cloud produced by a mid-range scanner demonstrates how open source software can make modeling and disseminating data easier. Normally, researchers would model this data using expensive specialized software, and the data wouldn't extend beyond the laser-scanning community.

  15. Verification of a CT scanner using a miniature step gauge

    DEFF Research Database (Denmark)

    Cantatore, Angela; Andreasen, J.L.; Carmignato, S.

    2011-01-01

    The work deals with performance verification of a CT scanner using a 42mm miniature replica step gauge developed for optical scanner verification. Errors quantification and optimization of CT system set-up in terms of resolution and measurement accuracy are fundamental for use of CT scanning...

  16. Quantitative Assay for Starch by Colorimetry Using a Desktop Scanner

    Science.gov (United States)

    Matthews, Kurt R.; Landmark, James D.; Stickle, Douglas F.

    2004-01-01

    The procedure to produce standard curve for starch concentration measurement by image analysis using a color scanner and computer for data acquisition and color analysis is described. Color analysis is performed by a Visual Basic program that measures red, green, and blue (RGB) color intensities for pixels within the scanner image.

  17. Vision Assisted Laser Scanner Navigation for Autonomous Robots

    DEFF Research Database (Denmark)

    Andersen, Jens Christian; Andersen, Nils Axel; Ravn, Ole

    2008-01-01

    This paper describes a navigation method based on road detection using both a laser scanner and a vision sensor. The method is to classify the surface in front of the robot into traversable segments (road) and obstacles using the laser scanner, this classifies the area just in front of the robot ...

  18. A comparison of the accuracy of intraoral scanners using an intraoral environment simulator.

    Science.gov (United States)

    Park, Hye-Nan; Lim, Young-Jun; Yi, Won-Jin; Han, Jung-Suk; Lee, Seung-Pyo

    2018-02-01

    The aim of this study was to design an intraoral environment simulator and to assess the accuracy of two intraoral scanners using the simulator. A box-shaped intraoral environment simulator was designed to simulate two specific intraoral environments. The cast was scanned 10 times by Identica Blue (MEDIT, Seoul, South Korea), TRIOS (3Shape, Copenhagen, Denmark), and CS3500 (Carestream Dental, Georgia, USA) scanners in the two simulated groups. The distances between the left and right canines (D3), first molars (D6), second molars (D7), and the left canine and left second molar (D37) were measured. The distance data were analyzed by the Kruskal-Wallis test. The differences in intraoral environments were not statistically significant ( P >.05). Between intraoral scanners, statistically significant differences ( P Kruskal-Wallis test with regard to D3 and D6. No difference due to the intraoral environment was revealed. The simulator will contribute to the higher accuracy of intraoral scanners in the future.

  19. Importance of professional qualification for operators of body scanners in prisons

    International Nuclear Information System (INIS)

    Kühn, P.; Huhn, A.

    2017-01-01

    Introduction: The implantation of the personal search by body scanners is gradually being implanted in Brazilian prisons. The body scanner, if operated by a qualified professional, allows the observation of images, generated by X-rays, of the whole body avoiding the intimate search, which is questioned for being embarrassing to the visitors of the inmates. The use of X-rays without control of absorbed doses may endanger the health of operators of equipment and, in the case of prisons, also to visitors. Method: Exploratory and descriptive, based on national and international legislation on the subject, in order to analyze and identify suitable training for the operation of body scanners. Results: The study was composed of the Standards and Recommendations of the National and International Nuclear Energy Commission. The results although the legislation does not clearly identify professional training to operate scanners in prisons, a broad knowledge on ionizing radiation and radiological protection is of the utmost importance. Conclusion: The manipulation of equipment generating ionizing radiation must be performed by qualified and authorized professional, to guarantee the principles of radiological protection to whoever operates the equipment and the population that will possibly be submitted to the personal search in the prison units. Therefore, it is understood that professionals with adequate training and competence to ensure the integrity of the health of all are the professional of Radiological Techniques and these must prove their training with registration in the specific Class Council

  20. Radiation exposure and privacy concerns surrounding full-body scanners in airports

    Directory of Open Access Journals (Sweden)

    Julie Accardo

    2014-04-01

    Full Text Available Millions of people filter through airport security check points in the United States every year. These security checks, in response to the post 9/11 and 2009 “Underwear Bomber” terrorist threats, have become increasingly burdensome to the general public due to the wide spread deployment of “enhanced screening systems.” The enhanced screening systems that have generated the most controversy are the passenger “full-body scanners.” These systems enable airport security personnel to effectively detect contraband (often concealed under clothing without the physical contact necessitated by a strip search. The two types of full-body scanners (also known as Advanced Imaging Technology systems, used in airports in the United States and around the world are referred to as backscatter technology units and millimeter-wave technology units. Although their respective radiation emissions vary, both scanners serve the same purpose; that is, the detection of concealed metallic and non-metallic threats in the form of liquids, gels, plastics, etc. Although enhanced screening systems were deployed to further public safety efforts, they have also generated wide spread public concern. Specifically, these concerns address the potential of adverse health and privacy issues that may result from continued public exposure to full-body scanner systems.

  1. Computer Tomography Scanners in Portugal (1990-2011

    Directory of Open Access Journals (Sweden)

    Ricardo Crispim

    2014-06-01

    Full Text Available The use of Computed Tomography (CT has increased every year since its introduction into medicine in 1972. Technological developments have made CT one of the most important imaging modalities in modern medicine. This importance is evidenced in the increasing demand and number of CT scanners installed in Portugal and worldwide. This review compiles the most recent national statistics from official publications on the number of CT scanners installed in Portugal and compares them with data available in international publications. We conclude that the number of CT scanners installed in Portugal exceeded the EU27 average by 61.5 % and the OECD average by 78.2 %, and that in 2011 there were 203 CT scanners installed in hospitals in Portugal, which equated to 19.23 CT scanners per million inhabitants.

  2. WE-AB-207A-03: A CBCT Head Scanner for Point-Of-Care Imaging of Intracranial Hemorrhage

    Energy Technology Data Exchange (ETDEWEB)

    Xu, J; Sisniega, A; Zbijewski, W; Dang, H; Stayman, J; Aygun, N; Koliatsos, V; Siewerdsen, J [Johns Hopkins University, Baltimore, MD (United States); Wang, X; Foos, D [Carestream Health, Rochester, New York (United States)

    2016-06-15

    Purpose: This work reports the design, development, and first technical assessment of a cone-beam CT (CBCT) scanner developed specifically for imaging of acute intracranial hemorrhage (ICH) at the point of care, with target applications in diagnosis and monitoring of traumatic brain injury, stroke, and postsurgical hemorrhage. Methods: System design employed a task-based image quality model to quantify the influence of factors such as additive noise and high-gain (HG) detector readout on ICH detectability. Three bowtie filters with varying bare-beam attenuation strength and curvature were designed to enable HG readout without detector saturation, and a polyenergetic gain correction was developed to minimize artifacts from bowtie flood-field calibration. Image reconstruction used an iterative penalized weighted least squares (PWLS) method with artifact correction including Monte Carlo scatter estimation, Joseph-Spital beam hardening correction, and spatiotemporal deconvolution of detector glare and lag. Radiation dose was characterized for half-scan and full-scan protocols at various kV, and imaging performance was assessed in a head phantom presenting simulated ICH with diameter ranging 2–12 mm. Results: The image quality model guided system design and was validated by measurements on a CBCT imaging bench. Compared to low-gain readout without a bowtie filter, the combination of HG readout and a modest bowtie improved the contrast-to-noise ratio (CNR per unit square-root dose) by 20% in the center of the image but degraded noise performance near the periphery (20% reduction in CNR). Low-frequency bowtie artifacts (∼100 HU magnitude) were corrected by the polyenergetic gain correction. Image reconstructions on the prototype scanner demonstrate clear visibility of the smallest ICH insert (2 mm diameter) in both HG readout (with a bowtie) and dual-gain readout (without bowtie). Conclusion: Technical assessment of the prototype scanner suggests the capability for

  3. Northern employment

    International Nuclear Information System (INIS)

    Zavitz, J.

    1997-01-01

    Hiring practices and policies and employment opportunities that were available in the Beaufort Sea and MacKenzie Delta project for local residents and for people from southern Canada were dealt with in this chapter. Depending on the source, Northern hiring was a mere token, or a genuine and successful effort on the part of the companies to involve the native population and to share with them the benefits of the project. The fact remains that opening up job opportunities for Northerners was not easily attained, and would never have been realized without the involvement of government and community organizations. Government also played a major role in developing policies and training regimes. By the end of exploration operations, the hiring of Northern residents in the oil and gas industry had become a requirement of drilling applications. Training programs were also created to ensure that Northern residents received the means necessary to take advantage of Northern employment opportunities

  4. Intraoral Scanner Technologies: A Review to Make a Successful Impression

    Directory of Open Access Journals (Sweden)

    Raphaël Richert

    2017-01-01

    Full Text Available To overcome difficulties associated with conventional techniques, impressions with IOS (intraoral scanner and CAD/CAM (computer-aided design and manufacturing technologies were developed for dental practice. The last decade has seen an increasing number of optical IOS devices, and these are based on different technologies; the choice of which may impact on clinical use. To allow informed choice before purchasing or renewing an IOS, this article summarizes first the technologies currently used (light projection, distance object determination, and reconstruction. In the second section, the clinical considerations of each strategy such as handling, learning curve, powdering, scanning paths, tracking, and mesh quality are discussed. The last section is dedicated to the accuracy of files and of the intermaxillary relationship registered with IOS as the rendering of files in the graphical user interface is often misleading. This overview leads to the conclusion that the current IOS is adapted for a common practice, although differences exist between the technologies employed. An important aspect highlighted in this review is the reduction in the volume of hardware which has led to an increase in the importance of software-based technologies.

  5. Aquilion ONE / ViSION Edition CT scanner realizing 3D dynamic observation with low-dose scanning

    International Nuclear Information System (INIS)

    Kazama, Masahiro; Saito, Yasuo

    2015-01-01

    Computed tomography (CT) scanners have been continuously advancing as essential diagnostic imaging equipment for the diagnosis and treatment of a variety of diseases, including the three major disease classes of cerebrovascular disease, cardiovascular disease, and cancer. Through the development of helical CT scanners and multislice CT scanners, Toshiba Medical Systems Corporation has developed the Aquilion ONE, a CT scanner with a scanning range of up to 160 mm per rotation that can obtain three-dimensional (3D) images of the brain, heart, and other organs in a single rotation. We have now developed the Aquilion ONE / ViSION Edition, a next-generation 320-row multislice CT scanner incorporating the latest technologies that achieves a shorter scanning time and significant reduction in dose compared with conventional products. This product with its low-dose scanning technology will contribute to the practical realization of new diagnosis and treatment modalities employing four-dimensional (4D) data based on 3D dynamic observations through continuous rotations. (author)

  6. Development of an indirect ELISA to detect Corynebacterium pseudotuberculosis specific antibodies in sheep employing T1 strain culture supernatant as antigen

    Directory of Open Access Journals (Sweden)

    Miriam F. Rebouças

    2013-11-01

    Full Text Available Corynebacterium pseudotuberculosis is the etiologic agent of caseous lymphadenitis (CLA, a chronic disease that affects goats and sheep, characterized by granuloma formation in subcutaneous and internal lymph nodes. CLA causes significant economic losses to commercial goat herds. In this study, we aimed to test secreted antigens secreted from T1 strain bacteria grown in brain heart infusion (BHI broth in an indirect ELISA system to determine the presence of specific immunoglobulins against C. pseudotuberculosis. We analyzed the BHI antigen electrophoretic profile and the recognition pattern by infected sheep sera samples. The ELISA results were compared with multiplex PCR assay and IFN-gamma production. The ELISA was able to discriminate between negative and positive animals, with a sensitivity of 89% and a specificity of 99%, using microbiological isolation as gold standard. When this assay was compared with multiplex PCR and specific IFN-gamma quantification, six discrepant results were found among thirty-two samples. We concluded that the ELISA using antigens secreted from C. pseudotuberculosis T1 strain growth in BHI broth culture can be used for the serodiagnosis of CLA in sheep.

  7. Digital data storage of core image using high resolution full color core scanner; Kokaizodo full color scanner wo mochiita core image no digital ka

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, W; Ujo, S; Osato, K; Takasugi, S [Geothermal Energy Research and Development Co. Ltd., Tokyo (Japan)

    1996-05-01

    This paper reports on digitization of core images by using a new type core scanner system. This system consists of a core scanner unit (equipped with a CCD camera), a personal computer and ancillary devices. This is a modification of the old type system, with measurable core length made to 100 cm/3 scans, and resolution enhanced to 5100 pixels/m (1024 pixels/m in the old type). The camera was changed to that of a color specification, and the A/D conversion was improved to 24-bit full color. As a result of carrying out a detail reproduction test on digital images of this core scanner, it was found that objects can be identified at a level of about the size of pixels constituting the image in the case when the best contrast is obtained between the objects and the background, and that in an evaluation test on visibility of concaves and convexes on core surface, reproducibility is not very good in large concaves and convexes. 2 refs., 6 figs.

  8. Whole-body 35-GHz security scanner

    Science.gov (United States)

    Appleby, Roger; Anderton, Rupert N.; Price, Sean; Sinclair, Gordon N.; Coward, Peter R.

    2004-08-01

    A 35GHz imager designed for Security Scanning has been previously demonstrated. That imager was based on a folded conical scan technology and was constructed from low cost materials such as expanded polystyrene and printed circuit board. In conjunction with an illumination chamber it was used to collect indoor imagery of people with weapons and contraband hidden under their clothing. That imager had a spot size of 20mm and covered a field of view of 20 x 10 degrees that partially covered the body of an adult from knees to shoulders. A new variant of this imager has been designed and constructed. It has a field of view of 36 x 18 degrees and is capable of covering the whole body of an adult. This was achieved by increasing the number of direct detection receivers from the 32 used in the previous design to 58, and by implementing an improved optical design. The optics consist of a front grid, a polarisation device which converts linear to circular polarisation and a rotating scanner. This new design uses high-density expanded polystyrene as a correcting element on the back of the front grid. This gives an added degree of freedom that allows the optical design to be diffraction limited over a very wide field of view. Obscuration by the receivers and associated components is minimised by integrating the post detection electronics at the receiver array.

  9. Focal plane scanner with reciprocating spatial window

    Science.gov (United States)

    Mao, Chengye (Inventor)

    2000-01-01

    A focal plane scanner having a front objective lens, a spatial window for selectively passing a portion of the image therethrough, and a CCD array for receiving the passed portion of the image. All embodiments have a common feature whereby the spatial window and CCD array are mounted for simultaneous relative reciprocating movement with respect to the front objective lens, and the spatial window is mounted within the focal plane of the front objective. In a first embodiment, the spatial window is a slit and the CCD array is one-dimensional, and successive rows of the image in the focal plane of the front objective lens are passed to the CCD array by an image relay lens interposed between the slit and the CCD array. In a second embodiment, the spatial window is a slit, the CCD array is two-dimensional, and a prism-grating-prism optical spectrometer is interposed between the slit and the CCD array so as to cause the scanned row to be split into a plurality of spectral separations onto the CCD array. In a third embodiment, the CCD array is two-dimensional and the spatial window is a rectangular linear variable filter (LVF) window, so as to cause the scanned rows impinging on the LVF to be bandpass filtered into spectral components onto the CCD array through an image relay lens interposed between the LVF and the CCD array.

  10. Fast and High Accuracy Wire Scanner

    CERN Document Server

    Koujili, M; Koopman, J; Ramos, D; Sapinski, M; De Freitas, J; Ait Amira, Y; Djerdir, A

    2009-01-01

    Scanning of a high intensity particle beam imposes challenging requirements on a Wire Scanner system. It is expected to reach a scanning speed of 20 m.s-1 with a position accuracy of the order of 1 μm. In addition a timing accuracy better than 1 millisecond is needed. The adopted solution consists of a fork holding a wire rotating by a maximum of 200°. Fork, rotor and angular position sensor are mounted on the same axis and located in a chamber connected to the beam vacuum. The requirements imply the design of a system with extremely low vibration, vacuum compatibility, radiation and temperature tolerance. The adopted solution consists of a rotary brushless synchronous motor with the permanent magnet rotor installed inside of the vacuum chamber and the stator installed outside. The accurate position sensor will be mounted on the rotary shaft inside of the vacuum chamber, has to resist a bake-out temperature of 200°C and ionizing radiation up to a dozen of kGy/year. A digital feedback controller allows maxi...

  11. APLIKASI INFO HALAL MENGGUNAKAN BARCODE SCANNER UNTUK SMARTPHONE ANDROID

    Directory of Open Access Journals (Sweden)

    Beki Subeki

    2016-05-01

    Full Text Available Abstract – In the production and trade of food products in the era of globalization, people are consuming, especially Muslims need to be given the knowledge, information and access to adequate in order to obtain the correct information about the halal status of products bought. The use of barcode scanners halal product information using the mobile platform is effective and useful for the public to find out information on a product. Barcode scanners can be read by optical scanners called barcode readers or scanned from an image by special software. In Indonesia, most mobile phones have the scanning software for 2D codes, and similar devices available via smartphone.   Keywords : Barcode Scanner, Mobile Platform, Halal Products, Smartphone     Abstrak - Dalam kegiatan produksi dan perdagangan produk pangan di era globalisasi ini, masyarakat yang mengkonsumsi, khususnya umat islam perlu diberikan pengetahuan tentang kehalalan produk, informasi dan akses yang memadai agar memperoleh informasi yang benar tentang status kehalalan produk yang dibelinya. Penggunaan barcode scanner informasi produk halal dengan menggunakan mobile platform dinilai cukup efektif dan berguna bagi masyarakat luas untuk mengetahui informasi sebuah produk. Barcode scanner dapat dibaca oleh pemindai optik yang disebut pembaca kode batang atau dipindai dari sebuah gambar oleh perangkat lunak khusus. Di Indonesia, kebanyakan telepon genggam memiliki perangkat lunak pemindai untuk kode 2D, dan perangkat sejenis tersedia melalui smartphone.   Kata Kunci: Barcode Scanner, Mobile Platform, Produk Halal, Smartphone

  12. Nimbus 7 Coastal Zone Color Scanner (CZCS). Level 1 data product users' guide

    Science.gov (United States)

    Williams, S. P.; Szajna, E. F.; Hovis, W. A.

    1985-01-01

    The coastal zone color scanner (CZCS) is a scanning multispectral radiometer designed specifically for the remote sensing of Ocean Color parameters from an Earth orbiting space platform. A technical manual which is intended for users of NIMBUS 7 CZCS Level 1 data products is presented. It contains information needed by investigators and data processing personnel to operate on the data using digital computers and related equipment.

  13. Evaluation of the ECAT EXACT HR+ 3D PET scanner in 15O-water brain activation studies

    International Nuclear Information System (INIS)

    Moreno-Cantu, J.J.; Thompson, C.J.; Zatorre, R.J.

    1996-01-01

    We evaluated the performance of the ECAT EXACT HR + 3D whole body PET scanner when employed to measure brain function using 15 O-water-bolus activation protocols in single data acquisition sessions. Using vibrotactile and auditory stimuli as independent activation tasks, we studied the scanner's performance under different imaging conditions in four healthy volunteers. Cerebral blood flow images were acquired from each volunteer using 15 O-water-bolus injections of activity varying from 5 to 20mCi. Performance characteristics. The scanner's dead time grew linearly with injected dose from 10% to 25%. Random events varied from 30% to 50% of the detected events. Scattered events were efficiently corrected at all doses. Noise-effective-count curves plateau at about 15mCi. One-session 12-injection bolus PET activation protocol. Using an acquisition protocol that accounts for the scanner's performance and the practical aspects of imaging volunteers and patients in one session, we assessed the correlation between the statistical significance of activation foci and the dose per injection used The one-session protocol employs 12 bolus injections per subject. We present evidence suggesting that 15-20mCi is the optimal dose per injection to be used routinely in one-time scanning sessions

  14. Pediatric radiation dose and risk from bone density measurements using a GE Lunar Prodigy scanner.

    Science.gov (United States)

    Damilakis, J; Solomou, G; Manios, G E; Karantanas, A

    2013-07-01

    Effective radiation doses associated with bone mineral density examinations performed on children using a GE Lunar Prodigy fan-beam dual-energy X-ray absorptiometry (DXA) scanner were found to be comparable to doses from pencil-beam DXA devices, i.e., lower than 1 μSv. Cancer risks associated with acquisitions obtained in this study are negligible. No data were found in the literature on radiation doses and potential risks following pediatric DXA performed on GE Lunar DXA scanners. This study aimed to estimate effective doses and associated cancer risks involved in pediatric examinations performed on a GE Lunar Prodigy scanner. Four physical anthropomorphic phantoms representing newborn, 1-, 5-, and 10-year-old patients were employed to simulate DXA exposures. All acquisitions were carried out using the Prodigy scanner. Dose measurements were performed for spine and dual femur using the phantoms simulating the 5- and 10-year-old child. Moreover, doses associated with whole-body examinations were measured for the four phantoms used in the current study. The gender-average effective dose for spine and hip examinations were 0.65 and 0.36 μSv, respectively, for the phantom representing the 5-year-old child and 0.93 and 0.205 μSv, respectively, for the phantom representing the 10-year-old child. Effective doses for whole-body examinations were 0.25, 0.22, 0.19, and 0.15 μSv for the neonate, 1-, 5-, and 10-year old child, respectively. The estimated lifetime cancer risks were negligible, i.e., 0.02-0.25 per million, depending on the sex, age, and type of DXA examination. A formula is presented for the estimation of effective dose from examinations performed on GE Lunar Prodigy scanners installed in other institutions. The effective doses and potential cancer risks associated with pediatric DXA examinations performed on a GE Lunar Prodigy fan-beam scanner were found to be comparable to doses and risks reported from pencil-beam DXA devices.

  15. Restoration of Hyperspectral Push-Broom Scanner Data

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Nielsen, Allan Aasbjerg; Conradsen, Knut

    1997-01-01

    Several effects combine to distort the multispectral data that are obtained from push-broom scanners. We develop an algorithm for restoration of such data, illustrated on images from the ROSIS scanner. In push-broom scanners variation between elements in the detector array results in a strong...... back into the original spectral space results in noise corrected variables. The noise components will now have been removed from the entire original data set by working on a smaller set of noise contaminated transformed variables only. The application of the above techniques results in a dramatic...

  16. PePSS - A portable sky scanner for measuring extremely low night-sky brightness

    Science.gov (United States)

    Kocifaj, Miroslav; Kómar, Ladislav; Kundracik, František

    2018-05-01

    A new portable sky scanner designed for low-light-level detection at night is developed and employed in night sky brightness measurements in a rural region. The fast readout, adjustable sensitivity and linear response guaranteed in 5-6 orders of magnitude makes the device well suited for narrow-band photometry in both dark areas and bright urban and suburban environments. Quasi-monochromatic night-sky brightness data are advantageous in the accurate characterization of spectral power distribution of scattered and emitted light and, also allows for the possibility to retrieve light output patterns from whole-city light sources. The sky scanner can operate in both night and day regimes, taking advantage of the complementarity of both radiance data types. Due to its inherent very high sensitivity the photomultiplier tube could be used in night sky radiometry, while the spectrometer-equipped system component capable of detecting elevated intensities is used in daylight monitoring. Daylight is a source of information on atmospheric optical properties that in turn are necessary in processing night sky radiances. We believe that the sky scanner has the potential to revolutionize night-sky monitoring systems.

  17. Precision of quantitative computed tomography texture analysis using image filtering: A phantom study for scanner variability.

    Science.gov (United States)

    Yasaka, Koichiro; Akai, Hiroyuki; Mackin, Dennis; Court, Laurence; Moros, Eduardo; Ohtomo, Kuni; Kiryu, Shigeru

    2017-05-01

    Quantitative computed tomography (CT) texture analyses for images with and without filtration are gaining attention to capture the heterogeneity of tumors. The aim of this study was to investigate how quantitative texture parameters using image filtering vary among different computed tomography (CT) scanners using a phantom developed for radiomics studies.A phantom, consisting of 10 different cartridges with various textures, was scanned under 6 different scanning protocols using four CT scanners from four different vendors. CT texture analyses were performed for both unfiltered images and filtered images (using a Laplacian of Gaussian spatial band-pass filter) featuring fine, medium, and coarse textures. Forty-five regions of interest were placed for each cartridge (x) in a specific scan image set (y), and the average of the texture values (T(x,y)) was calculated. The interquartile range (IQR) of T(x,y) among the 6 scans was calculated for a specific cartridge (IQR(x)), while the IQR of T(x,y) among the 10 cartridges was calculated for a specific scan (IQR(y)), and the median IQR(y) was then calculated for the 6 scans (as the control IQR, IQRc). The median of their quotient (IQR(x)/IQRc) among the 10 cartridges was defined as the variability index (VI).The VI was relatively small for the mean in unfiltered images (0.011) and for standard deviation (0.020-0.044) and entropy (0.040-0.044) in filtered images. Skewness and kurtosis in filtered images featuring medium and coarse textures were relatively variable across different CT scanners, with VIs of 0.638-0.692 and 0.430-0.437, respectively.Various quantitative CT texture parameters are robust and variable among different scanners, and the behavior of these parameters should be taken into consideration.

  18. Attenuation correction for freely moving small animal brain PET studies based on a virtual scanner geometry

    International Nuclear Information System (INIS)

    Angelis, G I; Kyme, A Z; Ryder, W J; Fulton, R R; Meikle, S R

    2014-01-01

    Attenuation correction in positron emission tomography brain imaging of freely moving animals is a very challenging problem since the torso of the animal is often within the field of view and introduces a non negligible attenuating factor that can degrade the quantitative accuracy of the reconstructed images. In the context of unrestrained small animal imaging, estimation of the attenuation correction factors without the need for a transmission scan is highly desirable. An attractive approach that avoids the need for a transmission scan involves the generation of the hull of the animal’s head based on the reconstructed motion corrected emission images. However, this approach ignores the attenuation introduced by the animal’s torso. In this work, we propose a virtual scanner geometry which moves in synchrony with the animal’s head and discriminates between those events that traversed only the animal’s head (and therefore can be accurately compensated for attenuation) and those that might have also traversed the animal’s torso. For each recorded pose of the animal’s head a new virtual scanner geometry is defined and therefore a new system matrix must be calculated leading to a time-varying system matrix. This new approach was evaluated on phantom data acquired on the microPET Focus 220 scanner using a custom-made phantom and step-wise motion. Results showed that when the animal’s torso is within the FOV and not appropriately accounted for during attenuation correction it can lead to bias of up to 10% . Attenuation correction was more accurate when the virtual scanner was employed leading to improved quantitative estimates (bias < 2%), without the need to account for the attenuation introduced by the extraneous compartment. Although the proposed method requires increased computational resources, it can provide a reliable approach towards quantitatively accurate attenuation correction for freely moving animal studies. (paper)

  19. Pure-Pursuit Reactive Path Tracking for Nonholonomic Mobile Robots with a 2D Laser Scanner

    Directory of Open Access Journals (Sweden)

    Jesús Morales

    2009-01-01

    Full Text Available Due to its simplicity and efficiency, the pure-pursuit path tracking method has been widely employed for planned navigation of nonholonomic ground vehicles. In this paper, we investigate the application of this technique for reactive tracking of paths that are implicitly defined by perceived environmental features. Goal points are obtained through an efficient interpretation of range data from an onboard 2D laser scanner to follow persons, corridors, and walls. Moreover, this formulation allows that a robotic mission can be composed of a combination of different types of path segments. These techniques have been successfully tested in the tracked mobile robot Auriga-α in an indoor environment.

  20. NOAA-9 Earth Radiation Budget Experiment (ERBE) scanner offsets determination

    Science.gov (United States)

    Avis, Lee M.; Paden, Jack; Lee, Robert B., III; Pandey, Dhirendra K.; Stassi, Joseph C.; Wilson, Robert S.; Tolson, Carol J.; Bolden, William C.

    1994-01-01

    The Earth Radiation Budget Experiment (ERBE) instruments are designed to measure the components of the radiative exchange between the Sun, Earth and space. ERBE is comprised of three spacecraft, each carrying a nearly identical set of radiometers: a three-channel narrow-field-of-view scanner, a two-channel wide-field-of-view (limb-to-limb) non-scanning radiometer, a two-channel medium field-of view (1000 km) non-scanning radiometer, and a solar monitor. Ground testing showed the scanners to be susceptible to self-generated and externally generated electromagnetic noise. This paper describes the pre-launch corrective measures taken and the post-launch corrections to the NOAA-9 scanner data. The NOAA-9 scanner has met the mission objectives in accuracy and precision, in part because of the pre-launch reductions of and post-launch data corrections for the electromagnetic noise.

  1. Landsat 1-5 Multispectral Scanner V1

    Data.gov (United States)

    National Aeronautics and Space Administration — Abstract: The Landsat Multispectral Scanner (MSS) was a sensor onboard Landsats 1 through 5 and acquired images of the Earth nearly continuously from July 1972 to...

  2. Design Optimization of a TOF, Breast PET Scanner

    OpenAIRE

    Lee, Eunsin; Werner, Matthew E.; Karp, Joel S.; Surti, Suleman

    2013-01-01

    A dedicated breast positron emission tomography (PET) scanner with limited angle geometry can provide flexibility in detector placement around the patient as well as the ability to combine it with other imaging modalities. A primary challenge of a stationary limited angle scanner is the reduced image quality due to artifacts present in the reconstructed image leading to a loss in quantitative information. Previously it has been shown that using time-of-flight (TOF) information in image recons...

  3. A fast ADC scanner for multiparameter nuclear physics experiments

    International Nuclear Information System (INIS)

    Midttun, G.; Ingebretsen, F.; Holt, K.; Skaali, B.

    1983-04-01

    A fast readout system for multiparameter experiments in nuclear physics is described. The central part of the CAMAC aquisition hardware is an ADC scanner module. The scanner incorporates a new arbitration logic and direct memory access for simultaneous transfer of singles and correlated data. Together with specially designed ADC interfaces the system can be set up for any configuration of singles and multiparameter events from 1 up to 15 ADC's in one crate

  4. A fast ADC scanner for multiparameter nuclear physics experiments

    International Nuclear Information System (INIS)

    Midttun, G.; Holt, K.; Ingebretsen, F.; Skaali, B.

    1983-01-01

    A fast readout system for multiparameter experiments in nuclear physics is described. The central part of the CAMAC aquisition hardware is an ADC scanner module. The scanner incorporates a new arbitration logic and direct memory access for simultaneous transfer of singles and correlated data. Together with specially designed ADC interfaces the system can be set up for any configurations of singles and multiparameter events from 1 up to 15 ADC's in one crate

  5. Utilization pattern of whole body computed tomography scanner

    International Nuclear Information System (INIS)

    Youn, Chul Ho; Lee, Sang Suk

    1986-01-01

    Computed tomography scanner (CT scanner) is one of the most expensive and sophisticated diagnostic tool and has already been utilized in many hospitals in Korea. The price as well as operating costs of CT scanner is so expensive as to regulate its installment by government even in the United States. In order to identify the efficient utilization of the CT scanner, the utilization pattern for CT scanning was analyzed at three general hospital in seoul. The results are as follows: 1. Five out of one thousand outpatients and five out of one hundred inpatients were CT scanned. 2. Eighty percent of patients who were scanned were those of inpatients of the hospitals where the scanned are installed. 3. Head standings constitute 45.6 percent of examinations, internal medicine 63.8 percent, and 38.5 percent neurosurgery respectively. 4. The rate of indication for CT scanning showed no statistically significant difference between insured and non-insured groups. 5. Computed tomography scanner units were operated 5.5 days a week in average and full operation rate was 79.5% in average. 6. The major diagnoses mode by head scanning were: hematoma (56.7%), infarction (12.6%), tumor (8.2%), and hydrocephalus (4.4%). 7. Number of patients taken CT Scanning was 43 persons a week in average for each whole body scanner unit

  6. Spatiotemporal matrix image formation for programmable ultrasound scanners

    Science.gov (United States)

    Berthon, Beatrice; Morichau-Beauchant, Pierre; Porée, Jonathan; Garofalakis, Anikitos; Tavitian, Bertrand; Tanter, Mickael; Provost, Jean

    2018-02-01

    As programmable ultrasound scanners become more common in research laboratories, it is increasingly important to develop robust software-based image formation algorithms that can be obtained in a straightforward fashion for different types of probes and sequences with a small risk of error during implementation. In this work, we argue that as the computational power keeps increasing, it is becoming practical to directly implement an approximation to the matrix operator linking reflector point targets to the corresponding radiofrequency signals via thoroughly validated and widely available simulations software. Once such a spatiotemporal forward-problem matrix is constructed, standard and thus highly optimized inversion procedures can be leveraged to achieve very high quality images in real time. Specifically, we show that spatiotemporal matrix image formation produces images of similar or enhanced quality when compared against standard delay-and-sum approaches in phantoms and in vivo, and show that this approach can be used to form images even when using non-conventional probe designs for which adapted image formation algorithms are not readily available.

  7. An ASIC implementation of digital front-end electronics for a high resolution PET scanner

    International Nuclear Information System (INIS)

    Newport, D.F.; Young, J.W.

    1993-01-01

    AN Application Specific Integrated Circuit (ASIC) has been designed and fabricated which implements many of the current functions found in the digital front-end electronics for a high resolution Positron Emission Tomography (PET) scanner. The ASIC performs crystal selection, energy qualification, time correction, and event counting functions for block technology high resolution PET scanners. Digitized x and y position, event energy, and time information are used by the ASIC to determine block crystal number, qualify the event based on energy, and correct the event time. In addition, event counting and block dead time calculations are performed for system dead time corrections. A loadable sequencer for controlling the analog front-end electronics is also implemented. The ASIC is implemented in a 37,000 gate, 1.0 micron CMOS gate-array and is capable of handling 4 million events/second while reducing parts count, cost, and power consumption over current board-level designs

  8. System Level Design of a Continuous-Time Delta-Sigma Modulator for Portable Ultrasound Scanners

    DEFF Research Database (Denmark)

    Llimos Muntal, Pere; Færch, Kjartan; Jørgensen, Ivan Harald Holger

    2015-01-01

    In this paper the system level design of a continuous-time ∆Σ modulator for portable ultrasound scanners is presented. The overall required signal-to-noise ratio (SNR) is derived to be 42 dB and the sampling frequency used is 320 MHz for an oversampling ratio of 16. In order to match these requir......, based on high-level VerilogA simulations, the performance of the ∆Σ modulator versus various block performance parameters is presented as trade-off curves. Based on these results, the block specifications are derived.......In this paper the system level design of a continuous-time ∆Σ modulator for portable ultrasound scanners is presented. The overall required signal-to-noise ratio (SNR) is derived to be 42 dB and the sampling frequency used is 320 MHz for an oversampling ratio of 16. In order to match...

  9. Heavy ion beam scanner for 14 UD Pelletron Accelerator, BARC- TIFR

    International Nuclear Information System (INIS)

    Nair, P.; Surendran, P.; Ninave, N.G.; Sparrow, Hillary; Gupta, S.K.; Bhagwat, P.V.; Iyer, R.H.

    2003-01-01

    Heavy ions from Pelletron accelerator were used for varied purposes, where beam is confined to the target in a small area by focusing. Larger area can be irradiated by defocusing the beam using quadrupoles but the size limitation of the defocused beam as well as Gaussian distribution of the particles in the specified area brings its own drawbacks. Uniform distribution over a large area needs scanning of the beam across the target. This difficulty was experienced during the initial attempts to make track etch membrane filters using heavy ions from Pelletron Accelerator. A beam scanner will fulfill this need effectively. The filters made are presently being used as supported liquid membranes (Slam) in separation sciences where their performance are at par with commercial membranes. These membranes are also being used by DRDO, Jodhpur for medical application. A beam scanner magnet as per our specification was made by Centre for Advanced Technology (CAT), Indore

  10. Initial investigation of a novel light-scattering gel phantom for evaluation of optical CT scanners for radiotherapy gel dosimetry

    International Nuclear Information System (INIS)

    Bosi, Stephen; Naseri, Pourandokht; Puran, Alicia; Davies, Justin; Baldock, Clive

    2007-01-01

    There is a need for stable gel materials for phantoms used to validate optical computerized tomography (CT) scanners used in conjunction with radiation-induced polymerizing gel dosimeters. Phantoms based on addition of light-absorbing dyes to gelatine to simulate gel dosimeters have been employed. However, to more accurately simulate polymerizing gels one requires phantoms that employ light-scattering colloidal suspensions added to the gel. In this paper, we present the initial results of using an optical CT scanner to evaluate a novel phantom in which radiation-exposed polymer gels are simulated by the addition of colloidal suspensions of varying turbidity. The phantom may be useful as a calibration transfer standard for polymer gel dosimeters. The tests reveal some phenomena peculiar to light-scattering gels that need to be taken into account when calibrating polymer gel dosimeters

  11. Fast, high-resolution 3D dosimetry utilizing a novel optical-CT scanner incorporating tertiary telecentric collimation

    International Nuclear Information System (INIS)

    Sakhalkar, H. S.; Oldham, M.

    2008-01-01

    This study introduces a charge coupled device (CCD) area detector based optical-computed tomography (optical-CT) scanner for comprehensive verification of radiation dose distributions recorded in nonscattering radiochromic dosimeters. Defining characteristics include: (i) a very fast scanning time of ∼5 min to acquire a complete three-dimensional (3D) dataset, (ii) improved image formation through the use of custom telecentric optics, which ensures accurate projection images and minimizes artifacts from scattered and stray-light sources, and (iii) high resolution (potentially 50 μm) isotropic 3D dose readout. The performance of the CCD scanner for 3D dose readout was evaluated by comparison with independent 3D readout from the single laser beam OCTOPUS-scanner for the same PRESAGE dosimeters. The OCTOPUS scanner was considered the 'gold standard' technique in light of prior studies demonstrating its accuracy. Additional comparisons were made against calculated dose distributions from the ECLIPSE treatment-planning system. Dose readout for the following treatments were investigated: (i) a single rectangular beam irradiation to investigate small field and very steep dose gradient dosimetry away from edge effects, (ii) a 2-field open beam parallel-opposed irradiation to investigate dosimetry along steep dose gradients, and (iii) a 7-field intensity modulated radiation therapy (IMRT) irradiation to investigate dosimetry for complex treatment delivery involving modulation of fluence and for dosimetry along moderate dose gradients. Dose profiles, dose-difference plots, and gamma maps were employed to evaluate quantitative estimates of agreement between independently measured and calculated dose distributions. Results indicated that dose readout from the CCD scanner was in agreement with independent gold-standard readout from the OCTOPUS-scanner as well as the calculated ECLIPSE dose distribution for all treatments, except in regions within a few millimeters of the

  12. Temporal resolution measurement of 128-slice dual source and 320-row area detector computed tomography scanners in helical acquisition mode using the impulse method.

    Science.gov (United States)

    Hara, Takanori; Urikura, Atsushi; Ichikawa, Katsuhiro; Hoshino, Takashi; Nishimaru, Eiji; Niwa, Shinji

    2016-04-01

    To analyse the temporal resolution (TR) of modern computed tomography (CT) scanners using the impulse method, and assess the actual maximum TR at respective helical acquisition modes. To assess the actual TR of helical acquisition modes of a 128-slice dual source CT (DSCT) scanner and a 320-row area detector CT (ADCT) scanner, we assessed the TRs of various acquisition combinations of a pitch factor (P) and gantry rotation time (R). The TR of the helical acquisition modes for the 128-slice DSCT scanner continuously improved with a shorter gantry rotation time and greater pitch factor. However, for the 320-row ADCT scanner, the TR with a pitch factor of pitch factor of >1.0, it was approximately one half of the gantry rotation time. The maximum TR values of single- and dual-source helical acquisition modes for the 128-slice DSCT scanner were 0.138 (R/P=0.285/1.5) and 0.074s (R/P=0.285/3.2), and the maximum TR values of the 64×0.5- and 160×0.5-mm detector configurations of the helical acquisition modes for the 320-row ADCT scanner were 0.120 (R/P=0.275/1.375) and 0.195s (R/P=0.3/0.6), respectively. Because the TR of a CT scanner is not accurately depicted in the specifications of the individual scanner, appropriate acquisition conditions should be determined based on the actual TR measurement. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  13. Scanner qualification with IntenCD based reticle error correction

    Science.gov (United States)

    Elblinger, Yair; Finders, Jo; Demarteau, Marcel; Wismans, Onno; Minnaert Janssen, Ingrid; Duray, Frank; Ben Yishai, Michael; Mangan, Shmoolik; Cohen, Yaron; Parizat, Ziv; Attal, Shay; Polonsky, Netanel; Englard, Ilan

    2010-03-01

    Scanner introduction into the fab production environment is a challenging task. An efficient evaluation of scanner performance matrices during factory acceptance test (FAT) and later on during site acceptance test (SAT) is crucial for minimizing the cycle time for pre and post production-start activities. If done effectively, the matrices of base line performance established during the SAT are used as a reference for scanner performance and fleet matching monitoring and maintenance in the fab environment. Key elements which can influence the cycle time of the SAT, FAT and maintenance cycles are the imaging, process and mask characterizations involved with those cycles. Discrete mask measurement techniques are currently in use to create across-mask CDU maps. By subtracting these maps from their final wafer measurement CDU map counterparts, it is possible to assess the real scanner induced printed errors within certain limitations. The current discrete measurement methods are time consuming and some techniques also overlook mask based effects other than line width variations, such as transmission and phase variations, all of which influence the final printed CD variability. Applied Materials Aera2TM mask inspection tool with IntenCDTM technology can scan the mask at high speed, offer full mask coverage and accurate assessment of all masks induced source of errors simultaneously, making it beneficial for scanner qualifications and performance monitoring. In this paper we report on a study that was done to improve a scanner introduction and qualification process using the IntenCD application to map the mask induced CD non uniformity. We will present the results of six scanners in production and discuss the benefits of the new method.

  14. Quality assurance for MR stereotactic imaging for three Siemens scanners

    International Nuclear Information System (INIS)

    Kozubikova, P.; Novotny, J. Jr.; Kulhova, K.; Mihalova, P.; Tamasova, J.; Veselsk, T.

    2014-01-01

    Quality assurance of stereotactic imaging, especially with MRI (magnetic resonance imaging), is a complex issue. It can be divided in the basic verification and commissioning of a particular new scanner or a new scanning MRI protocol that is being implemented into a clinical practice and the routine quality assurance performed for each single radiosurgical case. The aim of this study was geometric distortion assessment in MRI with a special PTGR (Physikalisch-Technische Gesellschaft fuer Radiologie - GmbH, Tuebingen, Germany) target phantom. PTGR phantom consists of 21 three-dimensional cross-hairs filled with contrast medium. Cross hairs are positioned at known Leksell coordinates with a precision of better than 0.1 mm and covering the whole stereotactic space. The phantom can be fixed in the Leksell stereotactic frame and thus stereotactic imaging procedures can be reproduced following exactly the same steps as for a real patient, including also the stereotactic image definition in the Leksell GammaPlan. Since the geometric position (stereotactic coordinates) of each cross-hair is known based on the construction of the phantom, it can be compared with the actual measured Leksell coordinates based on the stereotactic MRI. Deviations between expected and actual coordinates provide information about the level of distortion. The measured distortions proved satisfactory accuracy precision for stereotactic localization at 1.5 T Siemens Magnetom Avanto scanner, Siemens Magnetom Symphony scanner and 3T Siemens Magnetom Skyra scanner (Na Homolce Hospital, Prague). The mean distortion for these MR scanners for standard imaging protocol (T1 weighted 3D images) were 0.8 mm, 1.1 mm and 1.1 mm and maximum distortions were 1.3 mm, 1.9 mm and 2.2 mm, respectively.There was detected dependence of the distortions on the slice orientation and the type of imaging protocol. Image distortions are also property of each particular scanner, the worst distortion were observed for 3T

  15. Quantifying the Spatial Distribution of Hill Slope Erosion Using a 3-D Laser Scanner

    Science.gov (United States)

    Scholl, B. N.; Bogonko, M.; He, Y.; Beighley, R. E.; Milberg, C. T.

    2007-12-01

    Soil erosion is a complicated process involving many interdependent variables including rainfall intensity and duration, drop size, soil characteristics, ground cover, and surface slope. The interplay of these variables produces differing spatial patterns of rill versus inter-rill erosion by changing the effective energy from rain drop impacts and the quantities and timing of sheet and shallow, concentrated flow. The objective of this research is to characterize the spatial patterns of rill and inter-rill erosion produced from simulated rainfall on different soil densities and surface slopes using a 3-D laser scanner. The soil used in this study is a sandy loam with bulk density due to compaction ranging from 1.25-1.65 g/cm3. The surface slopes selected for this study are 25, 33, and 50 percent and represent common slopes used for grading on construction sites. The spatial patterns of soil erosion are measured using a Trimble GX DR 200+ 3D Laser Scanner which employs a time of flight calculation averaged over 4 points using a class 2, pulsed, 532 nm, green laser at a distance of 2 to 11 m from the surface. The scanner measures point locations on an approximately 5 mm grid. The pre- and post-erosion scan surfaces are compared to calculate the change in volume and the dimensions of rills and inter-rill areas. The erosion experiments were performed in the Soil Erosion Research Laboratory (SERL), part of the Civil and Environmental Engineering department at San Diego State University. SERL experiments utilize a 3-m by 10-m tilting soil bed with a soil depth of 0.5 meters. Rainfall is applied to the soil surface using two overhead Norton ladder rainfall simulators, which produce realistic rain drop diameters (median = 2.25 mm) and impact velocities. Simulated storm events used in this study consist of rainfall intensities ranging from 5, 10 to 15 cm/hr for durations of 20 to 30 minutes. Preliminary results are presented that illustrate a change in runoff processes and

  16. Improved Scanners for Microscopic Hyperspectral Imaging

    Science.gov (United States)

    Mao, Chengye

    2009-01-01

    Improved scanners to be incorporated into hyperspectral microscope-based imaging systems have been invented. Heretofore, in microscopic imaging, including spectral imaging, it has been customary to either move the specimen relative to the optical assembly that includes the microscope or else move the entire assembly relative to the specimen. It becomes extremely difficult to control such scanning when submicron translation increments are required, because the high magnification of the microscope enlarges all movements in the specimen image on the focal plane. To overcome this difficulty, in a system based on this invention, no attempt would be made to move either the specimen or the optical assembly. Instead, an objective lens would be moved within the assembly so as to cause translation of the image at the focal plane: the effect would be equivalent to scanning in the focal plane. The upper part of the figure depicts a generic proposed microscope-based hyperspectral imaging system incorporating the invention. The optical assembly of this system would include an objective lens (normally, a microscope objective lens) and a charge-coupled-device (CCD) camera. The objective lens would be mounted on a servomotor-driven translation stage, which would be capable of moving the lens in precisely controlled increments, relative to the camera, parallel to the focal-plane scan axis. The output of the CCD camera would be digitized and fed to a frame grabber in a computer. The computer would store the frame-grabber output for subsequent viewing and/or processing of images. The computer would contain a position-control interface board, through which it would control the servomotor. There are several versions of the invention. An essential feature common to all versions is that the stationary optical subassembly containing the camera would also contain a spatial window, at the focal plane of the objective lens, that would pass only a selected portion of the image. In one version

  17. Astrometric properties of the Tautenburg Plate Scanner

    Science.gov (United States)

    Brunzendorf, Jens; Meusinger, Helmut

    The Tautenburg Plate Scanner (TPS) is an advanced plate-measuring machine run by the Thüringer Landessternwarte Tautenburg (Karl Schwarzschild Observatory), where the machine is housed. It is capable of digitising photographic plates up to 30 cm × 30 cm in size. In our poster, we reported on tests and preliminary results of its astrometric properties. The essential components of the TPS consist of an x-y table movable between an illumination system and a direct imaging system. A telecentric lens images the light transmitted through the photographic emulsion onto a CCD line of 6000 pixels of 10 µm square size each. All components are mounted on a massive air-bearing table. Scanning is performed in lanes of up to 55 mm width by moving the x-y table in a continuous drift-scan mode perpendicular to the CCD line. The analogue output from the CCD is digitised to 12 bit with a total signal/noise ratio of 1000 : 1, corresponding to a photographic density range of three. The pixel map is produced as a series of optionally overlapping lane scans. The pixel data are stored onto CD-ROM or DAT. A Tautenburg Schmidt plate 24 cm × 24 cm in size is digitised within 2.5 hours resulting in 1.3 GB of data. Subsequent high-level data processing is performed off-line on other computers. During the scanning process, the geometry of the optical components is kept fixed. The optimal focussing of the optics is performed prior to the scan. Due to the telecentric lens refocussing is not required. Therefore, the main source of astrometric errors (beside the emulsion itself) are mechanical imperfections in the drive system, which have to be divided into random and systematic ones. The r.m.s. repeatability over the whole plate as measured by repeated scans of the same plate is about 0.5 µm for each axis. The mean plate-to-plate accuracy of the object positions on two plates with the same epoch and the same plate centre has been determined to be about 1 µm. This accuracy is comparable to

  18. LANSCE-R WIRE-SCANNER ANALOG FRONT-END ELECTRONICS

    International Nuclear Information System (INIS)

    Gruchalla, Michael E.

    2011-01-01

    A new AFE is being developed for the new LANSCE-R wire-scanner systems. The new AFE is implemented in a National Instruments Compact RIO (cRIO) module installed a BiRa 4U BiRIO cRIO chassis specifically designed to accommodate the cRIO crate and all the wire-scanner interface, control and motor-drive electronics. A single AFE module provides interface to both X and Y wire sensors using true DC coupled transimpedance amplifiers providing collection of the wire charge signals, real-time wire integrity verification using the normal dataacquisition system, and wire bias of 0V to +/-50V. The AFE system is designed to accommodate comparatively long macropulses (>1ms) with high PRF (>120Hz) without the need to provide timing signals. The basic AFE bandwidth is flat from true DC to 50kHz with a true first-order pole at 50kHz. Numeric integration in the cRIO FPGA provides real-time pulse-to-pulse numeric integration of the AFE signal to compute the total charge collected in each macropulse. This method of charge collection eliminates the need to provide synchronization signals to the wire-scanner AFE while providing the capability to accurately record the charge from long macropulses at high PRF.

  19. A New Generation of X-ray Baggage Scanners Based on a Different Physical Principle

    Directory of Open Access Journals (Sweden)

    Robert D. Speller

    2011-10-01

    Full Text Available X-ray baggage scanners play a basic role in the protection of airports, customs, and other strategically important buildings and infrastructures. The current technology of baggage scanners is based on x-ray attenuation, meaning that the detection of threat objects relies on how various objects differently attenuate the x-ray beams going through them. This capability is enhanced by the use of dual-energy x-ray scanners, which make the determination of the x-ray attenuation characteristics of a material more precise by taking images with different x-ray spectra, and combining the information appropriately. However, this still has limitations whenever objects with similar attenuation characteristics have to be distinguished. We describe an alternative approach based on a different x-ray interaction phenomenon, x-ray refraction. Refraction is a familiar phenomenon in visible light (e.g., what makes a straw half immersed in a glass of water appear bent, which also takes place in the x-ray regime, only causing deviations at much smaller angles. Typically, these deviations occur at the boundaries of all objects. We have developed a system that, like other “phase contrast” based instruments, is capable of detecting such deviations, and therefore of creating precise images of the contours of all objects. This complements the material-related information provided by x-ray attenuation, and helps contextualizing the nature of the individual objects, therefore resulting in an increase of both sensitivity (increased detection rate and specificity (reduced rate of false positives of baggage scanners.

  20. Growth, Employment and Structural Change

    DEFF Research Database (Denmark)

    Aggarwal, Aradhna

    2016-01-01

    This paper studies the decomposition of GSDP growth per capita in Punjab via-a-vis 15 other states in India during 1993–94 and 2011–12 in terms of employment and productivity growth. Specifically, it focuses on the role of employment growth and structural change in employment on economic growth...... but structural shifts have paid off well in terms of diversification of the economy and their contribution to labour productivity especially for manufacturing. Overall employment effect had been negative but this was essentially due to contraction in the labour force; the employment rate effect turned out...

  1. Miniaturized Fourier-plane fiber scanner for OCT endoscopy

    International Nuclear Information System (INIS)

    Vilches, Sergio; Kretschmer, Simon; Ataman, Çağlar; Zappe, Hans

    2017-01-01

    A forward-looking endoscopic optical coherence tomography (OCT) probe featuring a Fourier-plane fiber scanner is designed, manufactured and characterized. In contrast to common image-plane fiber scanners, the Fourier-plane scanner is a telecentric arrangement that eliminates vignetting and spatial resolution variations across the image plane. To scan the OCT beam in a spiral pattern, a tubular piezoelectric actuator is used to resonate an optical fiber bearing a collimating GRIN lens at its tip. The free-end of the GRIN lens sits at the back focal plane of an objective lens, such that its rotation replicates the beam angles in the collimated region of a classical telecentric 4f optical system. Such an optical arrangement inherently has a low numerical aperture combined with a relatively large field-of-view, rendering it particularly useful for endoscopic OCT imaging. Furthermore, the optical train of the Fourier-plane scanner is shorter than that of a comparable image-plane scanner by one focal length of the objective lens, significantly shortening the final arrangement. As a result, enclosed within a 3D printed housing of 2.5 mm outer diameter and 15 mm total length, the developed probe is the most compact forward-looking endoscopic OCT imager to date. Due to its compact form factor and compatibility with real-time OCT imaging, the developed probe is also ideal for use in the working channel of flexible endoscopes as a potential optical biopsy tool. (paper)

  2. Miniaturized Fourier-plane fiber scanner for OCT endoscopy

    Science.gov (United States)

    Vilches, Sergio; Kretschmer, Simon; Ataman, Çağlar; Zappe, Hans

    2017-10-01

    A forward-looking endoscopic optical coherence tomography (OCT) probe featuring a Fourier-plane fiber scanner is designed, manufactured and characterized. In contrast to common image-plane fiber scanners, the Fourier-plane scanner is a telecentric arrangement that eliminates vignetting and spatial resolution variations across the image plane. To scan the OCT beam in a spiral pattern, a tubular piezoelectric actuator is used to resonate an optical fiber bearing a collimating GRIN lens at its tip. The free-end of the GRIN lens sits at the back focal plane of an objective lens, such that its rotation replicates the beam angles in the collimated region of a classical telecentric 4f optical system. Such an optical arrangement inherently has a low numerical aperture combined with a relatively large field-of-view, rendering it particularly useful for endoscopic OCT imaging. Furthermore, the optical train of the Fourier-plane scanner is shorter than that of a comparable image-plane scanner by one focal length of the objective lens, significantly shortening the final arrangement. As a result, enclosed within a 3D printed housing of 2.5 mm outer diameter and 15 mm total length, the developed probe is the most compact forward-looking endoscopic OCT imager to date. Due to its compact form factor and compatibility with real-time OCT imaging, the developed probe is also ideal for use in the working channel of flexible endoscopes as a potential optical biopsy tool.

  3. Moths on the Flatbed Scanner: The Art of Joseph Scheer

    Directory of Open Access Journals (Sweden)

    Stephen L. Buchmann

    2011-12-01

    Full Text Available During the past decade a few artists and even fewer entomologists discovered flatbed scanning technology, using extreme resolution graphical arts scanners for acquiring high magnification digital images of plants, animals and inanimate objects. They are not just for trip receipts anymore. The special attributes of certain scanners, to image thick objects is discussed along with the technical features of the scanners including magnification, color depth and shadow detail. The work of pioneering scanner artist, Joseph Scheer from New York’s Alfred University is highlighted. Representative flatbed-scanned images of moths are illustrated along with techniques to produce them. Collecting and preparing moths, and other objects, for scanning are described. Highlights of the Fulbright sabbatical year of professor Scheer in Arizona and Sonora, Mexico are presented, along with comments on moths in science, folklore, art and pop culture. The use of flatbed scanners is offered as a relatively new method for visualizing small objects while acquiring large files for creating archival inkjet prints for display and sale.

  4. Characterization of a Large, Low-Cost 3D Scanner

    Directory of Open Access Journals (Sweden)

    Jeremy Straub

    2015-01-01

    Full Text Available Imagery-based 3D scanning can be performed by scanners with multiple form factors, ranging from small and inexpensive scanners requiring manual movement around a stationary object to large freestanding (nearly instantaneous units. Small mobile units are problematic for use in scanning living creatures, which may be unwilling or unable to (or for the very young and animals, unaware of the need to hold a fixed position for an extended period of time. Alternately, very high cost scanners that can capture a complete scan within a few seconds are available, but they are cost prohibitive for some applications. This paper seeks to assess the performance of a large, low-cost 3D scanner, presented in prior work, which is able to concurrently capture imagery from all around an object. It provides the capabilities of the large, freestanding units at a price point akin to the smaller, mobile ones. This allows access to 3D scanning technology (particularly for applications requiring instantaneous imaging at a lower cost. Problematically, prior analysis of the scanner’s performance was extremely limited. This paper characterizes the efficacy of the scanner for scanning both inanimate objects and humans. Given the importance of lighting to visible light scanning systems, the scanner’s performance under multiple lighting configurations is evaluated, characterizing its sensitivity to lighting design.

  5. Dental impressions using 3D digital scanners: virtual becomes reality.

    Science.gov (United States)

    Birnbaum, Nathan S; Aaronson, Heidi B

    2008-10-01

    The technologies that have made the use of three-dimensional (3D) digital scanners an integral part of many industries for decades have been improved and refined for application to dentistry. Since the introduction of the first dental impressioning digital scanner in the 1980s, development engineers at a number of companies have enhanced the technologies and created in-office scanners that are increasingly user-friendly and able to produce precisely fitting dental restorations. These systems are capable of capturing 3D virtual images of tooth preparations, from which restorations may be fabricated directly (ie, CAD/CAM systems) or fabricated indirectly (ie, dedicated impression scanning systems for the creation of accurate master models). The use of these products is increasing rapidly around the world and presents a paradigm shift in the way in which dental impressions are made. Several of the leading 3D dental digital scanning systems are presented and discussed in this article.

  6. Authenticity in Employment Relations

    OpenAIRE

    Tackney, Charles T.

    2014-01-01

    This research takes up the concept of authenticity as a criterion variable for theology of the workplace analysis, a domain which explores employment parameters in light of religious teaching on the social question at national, organizational or firm-specific levels. Following a review of the concept in Western culture, philosophy, and management studies, Religious Society of Friends (Quaker) and Roman Catholic social teachings are investigated for positively correlative data to help develop ...

  7. The Development of Dynamic Brand Equity Chase Model and Its Application to Digital Industry Based on Scanner Data

    OpenAIRE

    Nam Yongsik; Kwak Youngsik

    2009-01-01

    The purpose of this research is to develop a comprehensive modeling for measuring dynamics of brand power. We define brand power as brand specific coefficients to yield the sales volume for each period. The modeling consists of multinomial log it model for eachproduct category, the brand-specific coefficients, mixture modeling and fuzzy clustering algorithm. We apply our modeling to TV scanner data in Tianjin China. The results show 5 brands have 12 to 23 times change on their brand power in ...

  8. Free-space wavelength-multiplexed optical scanner.

    Science.gov (United States)

    Yaqoob, Z; Rizvi, A A; Riza, N A

    2001-12-10

    A wavelength-multiplexed optical scanning scheme is proposed for deflecting a free-space optical beam by selection of the wavelength of the light incident on a wavelength-dispersive optical element. With fast tunable lasers or optical filters, this scanner features microsecond domain scan setting speeds and large- diameter apertures of several centimeters or more for subdegree angular scans. Analysis performed indicates an optimum scan range for a given diffraction order and grating period. Limitations include beam-spreading effects based on the varying scanner aperture sizes and the instantaneous information bandwidth of the data-carrying laser beam.

  9. Cyclone: A laser scanner for mobile robot navigation

    Science.gov (United States)

    Singh, Sanjiv; West, Jay

    1991-09-01

    Researchers at Carnegie Mellon's Field Robotics Center have designed and implemented a scanning laser rangefinder. The device uses a commercially available time-of-flight ranging instrument that is capable of making up to 7200 measurements per second. The laser beam is reflected by a rotating mirror, producing up to a 360 degree view. Mounted on a robot vehicle, the scanner can be used to detect obstacles in the vehicle's path or to locate the robot on a map. This report discusses the motivation, design, and some applications of the scanner.

  10. Scanner baseliner monitoring and control in high volume manufacturing

    Science.gov (United States)

    Samudrala, Pavan; Chung, Woong Jae; Aung, Nyan; Subramany, Lokesh; Gao, Haiyong; Gomez, Juan-Manuel

    2016-03-01

    We analyze performance of different customized models on baseliner overlay data and demonstrate the reduction in overlay residuals by ~10%. Smart Sampling sets were assessed and compared with the full wafer measurements. We found that performance of the grid can still be maintained by going to one-third of total sampling points, while reducing metrology time by 60%. We also demonstrate the feasibility of achieving time to time matching using scanner fleet manager and thus identify the tool drifts even when the tool monitoring controls are within spec limits. We also explore the scanner feedback constant variation with illumination sources.

  11. Development of the Shimadzu computed tomographic scanner SCT-200N

    International Nuclear Information System (INIS)

    Ishihara, Hiroshi; Yamaoka, Nobuyuki; Saito, Masahiro

    1982-01-01

    The Shimadzu Computed Tomographic Scanner SCT-200N has been developed as an ideal CT scanner for diagnosing the head and spine. Due to the large aperture, moderate scan time and the Zoom Scan Mode, any part of the body can be scanned. High quality image can be obtained by adopting the precisely stabilized X-ray unit and densely packed array of 64-detectors. As for its operation, capability of computed radiography (CR) prior to patient positioning and real time reconstruction ensure efficient patient through-put. Details of the SCT-200N are described in this paper. (author)

  12. Isocount scintillation scanner with preset statistical data reliability

    International Nuclear Information System (INIS)

    Ikebe, J.; Yamaguchi, H.; Nawa, O.A.

    1975-01-01

    A scintillation detector scans an object such as a live body along horizontal straight scanning lines in such a manner that the scintillation detector is stopped at a scanning point during the time interval T required for counting a predetermined number of N pulses. The rate R/sub N/ = N/T is then calculated and the output signal pulses the number of which represents the rate R or the corresponding output signal is used as the recording signal for forming the scintigram. In contrast to the usual scanner, the isocount scanner scans an object stepwise in order to gather data with statistically uniform reliability

  13. Evaluating Employability Skills: Employer and Student Perceptions

    Science.gov (United States)

    Saunders, Venetia; Zuzel, Katherine

    2010-01-01

    Graduate employability is a key issue for Higher Education. In this two-part study student employability skills have been evaluated from the perspective of sandwich students and graduates in biomolecular science, and their employers. A strong correlation was found between employer and sandwich student/graduate perceptions of the relative…

  14. Quadratic Regression-based Non-uniform Response Correction for Radiochromic Film Scanners

    International Nuclear Information System (INIS)

    Jeong, Hae Sun; Kim, Chan Hyeong; Han, Young Yih; Kum, O Yeon

    2009-01-01

    In recent years, several types of radiochromic films have been extensively used for two-dimensional dose measurements such as dosimetry in radiotherapy as well as imaging and radiation protection applications. One of the critical aspects in radiochromic film dosimetry is the accurate readout of the scanner without dose distortion. However, most of charge-coupled device (CCD) scanners used for the optical density readout of the film employ a fluorescent lamp or a coldcathode lamp as a light source, which leads to a significant amount of light scattering on the active layer of the film. Due to the effect of the light scattering, dose distortions are produced with non-uniform responses, although the dose is uniformly irradiated to the film. In order to correct the distorted doses, a method based on correction factors (CF) has been reported and used. However, the prediction of the real incident doses is difficult when the indiscreet doses are delivered to the film, since the dose correction with the CF-based method is restrictively used in case that the incident doses are already known. In a previous study, therefore, a pixel-based algorithm with linear regression was developed to correct the dose distortion of a flatbed scanner, and to estimate the initial doses. The result, however, was not very good for some cases especially when the incident dose is under approximately 100 cGy. In the present study, the problem was addressed by replacing the linear regression with the quadratic regression. The corrected doses using this method were also compared with the results of other conventional methods

  15. MRI-assisted PET motion correction for neurologic studies in an integrated MR-PET scanner.

    Science.gov (United States)

    Catana, Ciprian; Benner, Thomas; van der Kouwe, Andre; Byars, Larry; Hamm, Michael; Chonde, Daniel B; Michel, Christian J; El Fakhri, Georges; Schmand, Matthias; Sorensen, A Gregory

    2011-01-01

    Head motion is difficult to avoid in long PET studies, degrading the image quality and offsetting the benefit of using a high-resolution scanner. As a potential solution in an integrated MR-PET scanner, the simultaneously acquired MRI data can be used for motion tracking. In this work, a novel algorithm for data processing and rigid-body motion correction (MC) for the MRI-compatible BrainPET prototype scanner is described, and proof-of-principle phantom and human studies are presented. To account for motion, the PET prompt and random coincidences and sensitivity data for postnormalization were processed in the line-of-response (LOR) space according to the MRI-derived motion estimates. The processing time on the standard BrainPET workstation is approximately 16 s for each motion estimate. After rebinning in the sinogram space, the motion corrected data were summed, and the PET volume was reconstructed using the attenuation and scatter sinograms in the reference position. The accuracy of the MC algorithm was first tested using a Hoffman phantom. Next, human volunteer studies were performed, and motion estimates were obtained using 2 high-temporal-resolution MRI-based motion-tracking techniques. After accounting for the misalignment between the 2 scanners, perfectly coregistered MRI and PET volumes were reproducibly obtained. The MRI output gates inserted into the PET list-mode allow the temporal correlation of the 2 datasets within 0.2 ms. The Hoffman phantom volume reconstructed by processing the PET data in the LOR space was similar to the one obtained by processing the data using the standard methods and applying the MC in the image space, demonstrating the quantitative accuracy of the procedure. In human volunteer studies, motion estimates were obtained from echo planar imaging and cloverleaf navigator sequences every 3 s and 20 ms, respectively. Motion-deblurred PET images, with excellent delineation of specific brain structures, were obtained using these 2 MRI

  16. MR-assisted PET Motion Correction for eurological Studies in an Integrated MR-PET Scanner

    Science.gov (United States)

    Catana, Ciprian; Benner, Thomas; van der Kouwe, Andre; Byars, Larry; Hamm, Michael; Chonde, Daniel B.; Michel, Christian J.; El Fakhri, Georges; Schmand, Matthias; Sorensen, A. Gregory

    2011-01-01

    Head motion is difficult to avoid in long PET studies, degrading the image quality and offsetting the benefit of using a high-resolution scanner. As a potential solution in an integrated MR-PET scanner, the simultaneously acquired MR data can be used for motion tracking. In this work, a novel data processing and rigid-body motion correction (MC) algorithm for the MR-compatible BrainPET prototype scanner is described and proof-of-principle phantom and human studies are presented. Methods To account for motion, the PET prompts and randoms coincidences as well as the sensitivity data are processed in the line or response (LOR) space according to the MR-derived motion estimates. After sinogram space rebinning, the corrected data are summed and the motion corrected PET volume is reconstructed from these sinograms and the attenuation and scatter sinograms in the reference position. The accuracy of the MC algorithm was first tested using a Hoffman phantom. Next, human volunteer studies were performed and motion estimates were obtained using two high temporal resolution MR-based motion tracking techniques. Results After accounting for the physical mismatch between the two scanners, perfectly co-registered MR and PET volumes are reproducibly obtained. The MR output gates inserted in to the PET list-mode allow the temporal correlation of the two data sets within 0.2 s. The Hoffman phantom volume reconstructed processing the PET data in the LOR space was similar to the one obtained processing the data using the standard methods and applying the MC in the image space, demonstrating the quantitative accuracy of the novel MC algorithm. In human volunteer studies, motion estimates were obtained from echo planar imaging and cloverleaf navigator sequences every 3 seconds and 20 ms, respectively. Substantially improved PET images with excellent delineation of specific brain structures were obtained after applying the MC using these MR-based estimates. Conclusion A novel MR-based MC

  17. The feasibility of a scanner-independent technique to estimate organ dose from MDCT scans: Using CTDIvol to account for differences between scanners

    International Nuclear Information System (INIS)

    Turner, Adam C.; Zankl, Maria; DeMarco, John J.; Cagnon, Chris H.; Zhang Di; Angel, Erin; Cody, Dianna D.; Stevens, Donna M.; McCollough, Cynthia H.; McNitt-Gray, Michael F.

    2010-01-01

    Purpose: Monte Carlo radiation transport techniques have made it possible to accurately estimate the radiation dose to radiosensitive organs in patient models from scans performed with modern multidetector row computed tomography (MDCT) scanners. However, there is considerable variation in organ doses across scanners, even when similar acquisition conditions are used. The purpose of this study was to investigate the feasibility of a technique to estimate organ doses that would be scanner independent. This was accomplished by assessing the ability of CTDI vol measurements to account for differences in MDCT scanners that lead to organ dose differences. Methods: Monte Carlo simulations of 64-slice MDCT scanners from each of the four major manufacturers were performed. An adult female patient model from the GSF family of voxelized phantoms was used in which all ICRP Publication 103 radiosensitive organs were identified. A 120 kVp, full-body helical scan with a pitch of 1 was simulated for each scanner using similar scan protocols across scanners. From each simulated scan, the radiation dose to each organ was obtained on a per mA s basis (mGy/mA s). In addition, CTDI vol values were obtained from each scanner for the selected scan parameters. Then, to demonstrate the feasibility of generating organ dose estimates from scanner-independent coefficients, the simulated organ dose values resulting from each scanner were normalized by the CTDI vol value for those acquisition conditions. Results: CTDI vol values across scanners showed considerable variation as the coefficient of variation (CoV) across scanners was 34.1%. The simulated patient scans also demonstrated considerable differences in organ dose values, which varied by up to a factor of approximately 2 between some of the scanners. The CoV across scanners for the simulated organ doses ranged from 26.7% (for the adrenals) to 37.7% (for the thyroid), with a mean CoV of 31.5% across all organs. However, when organ doses

  18. Track counting and thickness measurement of LR115 radon detectors using a commercial image scanner

    International Nuclear Information System (INIS)

    De Cicco, F.; Pugliese, M.; Roca, V.; Sabbarese, C.

    2014-01-01

    An original optical method for track counting and film thickness determination of etched LR115 radon detectors was developed. The method offers several advantages compared with standard techniques. In particular, it is non-destructive, very simple and rather inexpensive, since it uses a commercial scanner and a free software. The complete analysis and the calibration procedure carried out for the determination of radon specific activity are reported. A comparison with the results of spark counting defines the accuracy and the precision of the new technique. (authors)

  19. Design of a high-precision fast wire scanner for the SPS at CERN

    CERN Document Server

    Veness, R; Dehning, B; Emery, J; Herranz Alvarez, J; Koujili, M; Samuelsson, S; Sirvent, J-L

    2012-01-01

    Studies are going on of a new wire scanner concept. All moving parts are inside the beam vacuum and it is specified for use in all the machines across the CERN accelerator complex. Key components have been developed and tested. Work is now focussing on the installation of a prototype for test in the Super Proton Synchrotron (SPS) accelerator. This article presents the specification of the device and constraints on the design for integration in the different accelerators at CERN. The design issues of the mechanical components are discussed and optimisation work shown. Finally, the prototype design, integrating the several components into the vacuum tank is presented.

  20. Teach Your Computer to Read: Scanners and Optical Character Recognition.

    Science.gov (United States)

    Marsden, Jim

    1993-01-01

    Desktop scanners can be used with a software technology called optical character recognition (OCR) to convert the text on virtually any paper document into an electronic form. OCR offers educators new flexibility in incorporating text into tests, lesson plans, and other materials. (MLF)

  1. Feature-space transformation improves supervised segmentation across scanners

    DEFF Research Database (Denmark)

    van Opbroek, Annegreet; Achterberg, Hakim C.; de Bruijne, Marleen

    2015-01-01

    Image-segmentation techniques based on supervised classification generally perform well on the condition that training and test samples have the same feature distribution. However, if training and test images are acquired with different scanners or scanning parameters, their feature distributions...

  2. Free-space wavelength-multiplexed optical scanner demonstration.

    Science.gov (United States)

    Yaqoob, Zahid; Riza, Nabeel A

    2002-09-10

    Experimental demonstration of a no-moving-parts free-space wavelength-multiplexed optical scanner (W-MOS) is presented. With fast tunable lasers or optical filters and planar wavelength dispersive elements such as diffraction gratings, this microsecond-speed scanner enables large several-centimeter apertures for subdegree angular scans. The proposed W-MOS design incorporates a unique optical amplifier and variable optical attenuator combination that enables the calibration and modulation of the scanner response, leading to any desired scanned laser beam power shaping. The experimental setup uses a tunable laser centered at 1560 nm and a 600-grooves/mm blazed reflection grating to accomplish an angular scan of 12.92 degrees as the source is tuned over an 80-nm bandwidth. The values for calculated maximum optical beam divergance, required wavelength resolution, beam-pointing accuracy, and measured scanner insertion loss are 1.076 mrad, 0.172 nm, 0.06 mrad, and 4.88 dB, respectively.

  3. Sea surface temperature mapping using a thermal infrared scanner

    Digital Repository Service at National Institute of Oceanography (India)

    RameshKumar, M.R; Pandya, R; Mathur, K.M.; Charyulu, R; Rao, L.V.G.

    1 metre water column below the sea surface. A thermal infrared scanner developed by the Space Applications Centre (ISRO), Ahmedabad was operated on board R.V. Gaveshani in April/May 1984 for mapping SST over the eastern Arabian Sea. SST values...

  4. The economic potential of CT scanners for hardwood sawmills

    Science.gov (United States)

    Donald G. Hodges; Walter C. Anderson; Charles W. McMillin

    1990-01-01

    Research has demonstrated that a knowledge of internal log defects prior to sawing could improve lumber value yields significantly. This study evaluated the potential economic returns from investments in computerized tomographic (CT) scanners to detect internal defects in hardwood logs at southern sawmills. The results indicate that such investments would be profitable...

  5. Phosphor Scanner For Imaging X-Ray Diffraction

    Science.gov (United States)

    Carter, Daniel C.; Hecht, Diana L.; Witherow, William K.

    1992-01-01

    Improved optoelectronic scanning apparatus generates digitized image of x-ray image recorded in phosphor. Scanning fiber-optic probe supplies laser light stimulating luminescence in areas of phosphor exposed to x rays. Luminescence passes through probe and fiber to integrating sphere and photomultiplier. Sensitivity and resolution exceed previously available scanners. Intended for use in x-ray crystallography, medical radiography, and molecular biology.

  6. Benchmarking Advanced Control Algorithms for a Laser Scanner System

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Ordys, A.W.; Smillie, I.

    1996-01-01

    The paper describes tests performed on the laser scanner system toassess feasibility of modern control techniques in achieving a requiredperformance in the trajectory following problem. The two methods tested areQTR H-infinity and Predictive Control. The results are ilustated ona simulation example....

  7. Scanner image methodology (SIM) to measure dimensions of leaves ...

    African Journals Online (AJOL)

    A scanner image methodology was used to determine plant dimensions, such as leaf area, length and width. The values obtained using SIM were compared with those recorded by the LI-COR leaf area meter. Bias, linearity, reproducibility and repeatability (R&R) were evaluated for SIM. Different groups of leaves were ...

  8. Algorithms for Coastal-Zone Color-Scanner Data

    Science.gov (United States)

    1986-01-01

    Software for Nimbus-7 Coastal-Zone Color-Scanner (CZCS) derived products consists of set of scientific algorithms for extracting information from CZCS-gathered data. Software uses CZCS-generated Calibrated RadianceTemperature (CRT) tape as input and outputs computer-compatible tape and film product.

  9. Demonstration: A smartphone 3D functional brain scanner

    DEFF Research Database (Denmark)

    Stahlhut, Carsten; Stopczynski, Arkadiusz; Larsen, Jakob Eg

    We demonstrate a fully portable 3D real-time functional brain scanner consisting of a wireless 14-channel ‘Neuroheadset‘ (Emotiv EPOC) and a Nokia N900 smartphone. The novelty of our system is the ability to perform real-time functional brain imaging on a smartphone device, including stimulus...

  10. Design of active-neutron fuel rod scanner

    International Nuclear Information System (INIS)

    Griffith, G.W.; Menlove, H.O.

    1996-01-01

    An active-neutron fuel rod scanner has been designed for the assay of fissile materials in mixed oxide fuel rods. A 252 Cf source is located at the center of the scanner very near the through hole for the fuel rods. Spontaneous fission neutrons from the californium are moderated and induce fissions within the passing fuel rod. The rod continues past a combined gamma-ray and neutron shield where delayed gamma rays above 1 MeV are detected. We used the Monte Carlo code MCNP to design the scanner and review optimum materials and geometries. An inhomogeneous beryllium, graphite, and polyethylene moderator has been designed that uses source neutrons much more efficiently than assay systems using polyethylene moderators. Layers of borated polyethylene and tungsten are used to shield the detectors. Large NaI(Tl) detectors were selected to measure the delayed gamma rays. The enrichment zones of a thermal reactor fuel pin could be measured to within 1% counting statistics for practical rod speeds. Applications of the rod scanner include accountability of fissile material for safeguards applications, quality control of the fissile content in a fuel rod, and the verification of reactivity potential for mixed oxide fuels. (orig.)

  11. Implementation of fast macromolecular proton fraction mapping on 1.5 and 3 Tesla clinical MRI scanners: preliminary experience

    Science.gov (United States)

    Yarnykh, V.; Korostyshevskaya, A.

    2017-08-01

    Macromolecular proton fraction (MPF) is a biophysical parameter describing the amount of macromolecular protons involved into magnetization exchange with water protons in tissues. MPF represents a significant interest as a magnetic resonance imaging (MRI) biomarker of myelin for clinical applications. A recent fast MPF mapping method enabled clinical translation of MPF measurements due to time-efficient acquisition based on the single-point constrained fit algorithm. However, previous MPF mapping applications utilized only 3 Tesla MRI scanners and modified pulse sequences, which are not commonly available. This study aimed to test the feasibility of MPF mapping implementation on a 1.5 Tesla clinical scanner using standard manufacturer’s sequences and compare the performance of this method between 1.5 and 3 Tesla scanners. MPF mapping was implemented on 1.5 and 3 Tesla MRI units of one manufacturer with either optimized custom-written or standard product pulse sequences. Whole-brain three-dimensional MPF maps obtained from a single volunteer were compared between field strengths and implementation options. MPF maps demonstrated similar quality at both field strengths. MPF values in segmented brain tissues and specific anatomic regions appeared in close agreement. This experiment demonstrates the feasibility of fast MPF mapping using standard sequences on 1.5 T and 3 T clinical scanners.

  12. A miniaturized, high frequency mechanical scanner for high speed atomic force microscope using suspension on dynamically determined points

    Energy Technology Data Exchange (ETDEWEB)

    Herfst, Rodolf; Dekker, Bert; Witvoet, Gert; Crowcombe, Will; Lange, Dorus de [Department of Optomechatronics, Netherlands Organization for Applied Scientific Research, TNO, Delft (Netherlands); Sadeghian, Hamed, E-mail: hamed.sadeghianmarnani@tno.nl, E-mail: h.sadeghianmarnani@tudelft.nl [Department of Optomechatronics, Netherlands Organization for Applied Scientific Research, TNO, Delft (Netherlands); Department of Precision and Microsystems Engineering, Delft University of Technology, Delft (Netherlands)

    2015-11-15

    One of the major limitations in the speed of the atomic force microscope (AFM) is the bandwidth of the mechanical scanning stage, especially in the vertical (z) direction. According to the design principles of “light and stiff” and “static determinacy,” the bandwidth of the mechanical scanner is limited by the first eigenfrequency of the AFM head in case of tip scanning and by the sample stage in terms of sample scanning. Due to stringent requirements of the system, simply pushing the first eigenfrequency to an ever higher value has reached its limitation. We have developed a miniaturized, high speed AFM scanner in which the dynamics of the z-scanning stage are made insensitive to its surrounding dynamics via suspension of it on specific dynamically determined points. This resulted in a mechanical bandwidth as high as that of the z-actuator (50 kHz) while remaining insensitive to the dynamics of its base and surroundings. The scanner allows a practical z scan range of 2.1 μm. We have demonstrated the applicability of the scanner to the high speed scanning of nanostructures.

  13. In vivo cellular imaging with microscopes enabled by MEMS scanners

    Science.gov (United States)

    Ra, Hyejun

    High-resolution optical imaging plays an important role in medical diagnosis and biomedical research. Confocal microscopy is a widely used imaging method for obtaining cellular and sub-cellular images of biological tissue in reflectance and fluorescence modes. Its characteristic optical sectioning capability also enables three-dimensional (3-D) image reconstruction. However, its use has mostly been limited to excised tissues due to the requirement of high numerical aperture (NA) lenses for cellular resolution. Microscope miniaturization can enable in vivo imaging to make possible early cancer diagnosis and biological studies in the innate environment. In this dissertation, microscope miniaturization for in vivo cellular imaging is presented. The dual-axes confocal (DAC) architecture overcomes limitations of the conventional single-axis confocal (SAC) architecture to allow for miniaturization with high resolution. A microelectromechanical systems (MEMS) scanner is the central imaging component that is key in miniaturization of the DAC architecture. The design, fabrication, and characterization of the two-dimensional (2-D) MEMS scanner are presented. The gimbaled MEMS scanner is fabricated on a double silicon-on-insulator (SOI) wafer and is actuated by self-aligned vertical electrostatic combdrives. The imaging performance of the MEMS scanner in a DAC configuration is shown in a breadboard microscope setup, where reflectance and fluorescence imaging is demonstrated. Then, the MEMS scanner is integrated into a miniature DAC microscope. The whole imaging system is integrated into a portable unit for research in small animal models of human biology and disease. In vivo 3-D imaging is demonstrated on mouse skin models showing gene transfer and siRNA silencing. The siRNA silencing process is sequentially imaged in one mouse over time.

  14. Method for calibration of an axial tomographic scanner

    International Nuclear Information System (INIS)

    Sparks, R.A.

    1977-01-01

    The method of calibrating an axial tomographic scanner including frame means having an opening therein in which an object to be examined is to be placed, source and detector means mounted on the frame means for directing one or more beams of penetrating radiation through the object from the source to the detector means, and means to rotate the scanner including the source and detector means about the object whereby a plurality of sets of data corresponding to the transmission or absorption by the object of a plurality of beams of penetrating radiation are collected; the calibration method comprising mounting calibration means supporting an adjustable centering member onto the frame means, positioning the adjustable centering member at approximately the center of rotation of the scanner, placing position-sensitive indicator means adjacent the approximately centered member, rotating the scanner and the calibration means mounted thereon at least one time and, if necessary, adjusting the positioning of the centering member until the centering member is coincident with the center of rotation of the scanner as determined by minimum deflection of the position-sensitive indicator means, rotating and translating the source and detector means and determining for each angular orientation of the frame means supporting the source and detector means the central position of each translational scan relative to the centered member and/or if a plurality of detectors are utilized with the detector means for each planar slice of the object being examined, the central position of each translational scan for each detector relative to the centered member

  15. NMR of geophysical drill cores with a mobile Halbach scanner

    International Nuclear Information System (INIS)

    Talnishnikh, E.

    2007-01-01

    This thesis is devoted to a mobile NMR with an improved Halbach scanner. This is a lightweight tube-shaped magnet with sensitive volume larger and a homogeneity of the magnetic field higher than the previous prototype version. The improved Halbach scanner is used for analysis of water-saturated drill cores and plugs with diameters up to 60 mm. To provide the analysis, the standard 1D technique with the CPMG sequence as well as 2D correlation experiments were successfully applied and adapted to study properties of fluid-saturated sediments. Afterwards the Halbach scanner was calibrated to fast non-destructive measurements of porosity, relaxation time distributions, and estimation of permeability. These properties can be calculated directly from the NMR data using the developed methodology. Any independent measurements of these properties with other methods are not needed. One of the main results of this work is the development of a new NMR on-line core scanner for measurements of porosity in long cylindrical and semi cylindrical drill cores. Also dedicated software was written to operate the NMR on-line core scanner. The physical background of this work is the study of the diffusion influence on transverse relaxation. The diffusion effect in the presence of internal gradients in porous media was probed by 1D and 2D experiments. The transverse relaxation time distributions obtained from 1D and from 2D experiments are comparable but different in fine details. Two new methodologies were developed based on the results of this study. First is the methodology quantifying the influence of diffusion in the internal gradients of water-saturated sediments on transverse relaxation from 2D correlation experiments. The second one is the correction of the permeability estimation from the NMR data taking in account the influence of the diffusion. Furthermore, PFG NMR technique was used to study restricted diffusion in the same kind of samples. Preliminary results are reported

  16. NMR of geophysical drill cores with a mobile Halbach scanner

    Energy Technology Data Exchange (ETDEWEB)

    Talnishnikh, E.

    2007-08-21

    This thesis is devoted to a mobile NMR with an improved Halbach scanner. This is a lightweight tube-shaped magnet with sensitive volume larger and a homogeneity of the magnetic field higher than the previous prototype version. The improved Halbach scanner is used for analysis of water-saturated drill cores and plugs with diameters up to 60 mm. To provide the analysis, the standard 1D technique with the CPMG sequence as well as 2D correlation experiments were successfully applied and adapted to study properties of fluid-saturated sediments. Afterwards the Halbach scanner was calibrated to fast non-destructive measurements of porosity, relaxation time distributions, and estimation of permeability. These properties can be calculated directly from the NMR data using the developed methodology. Any independent measurements of these properties with other methods are not needed. One of the main results of this work is the development of a new NMR on-line core scanner for measurements of porosity in long cylindrical and semi cylindrical drill cores. Also dedicated software was written to operate the NMR on-line core scanner. The physical background of this work is the study of the diffusion influence on transverse relaxation. The diffusion effect in the presence of internal gradients in porous media was probed by 1D and 2D experiments. The transverse relaxation time distributions obtained from 1D and from 2D experiments are comparable but different in fine details. Two new methodologies were developed based on the results of this study. First is the methodology quantifying the influence of diffusion in the internal gradients of water-saturated sediments on transverse relaxation from 2D correlation experiments. The second one is the correction of the permeability estimation from the NMR data taking in account the influence of the diffusion. Furthermore, PFG NMR technique was used to study restricted diffusion in the same kind of samples. Preliminary results are reported

  17. Navigated MRI-guided liver biopsies in a closed-bore scanner: experience in 52 patients.

    Science.gov (United States)

    Moche, Michael; Heinig, Susann; Garnov, Nikita; Fuchs, Jochen; Petersen, Tim-Ole; Seider, Daniel; Brandmaier, Philipp; Kahn, Thomas; Busse, Harald

    2016-08-01

    To evaluate clinical effectiveness and diagnostic efficiency of a navigation device for MR-guided biopsies of focal liver lesions in a closed-bore scanner. In 52 patients, 55 biopsies were performed. An add-on MR navigation system with optical instrument tracking was used for image guidance and biopsy device insertion outside the bore. Fast control imaging allowed visualization of the true needle position at any time. The biopsy workflow and procedure duration were recorded. Histological analysis and clinical course/outcome were used to calculate sensitivity, specificity and diagnostic accuracy. Fifty-four of 55 liver biopsies were performed successfully with the system. No major and four minor complications occurred. Mean tumour size was 23 ± 14 mm and the skin-to-target length ranged from 22 to 177 mm. In 39 cases, access path was double oblique. Sensitivity, specificity and diagnostic accuracy were 88 %, 100 % and 92 %, respectively. The mean procedure time was 51 ± 12 min, whereas the puncture itself lasted 16 ± 6 min. On average, four control scans were taken. Using this navigation device, biopsies of poorly visible and difficult accessible liver lesions could be performed safely and reliably in a closed-bore MRI scanner. The system can be easily implemented in clinical routine workflow. • Targeted liver biopsies could be reliably performed in a closed-bore MRI. • The navigation system allows for image guidance outside of the scanner bore. • Assisted MRI-guided biopsies are helpful for focal lesions with a difficult access. • Successful integration of the method in clinical workflow was shown. • Subsequent system installation in an existing MRI environment is feasible.

  18. Employment specialist competencies for supported employment programs

    NARCIS (Netherlands)

    Corbière, M.; Brouwers, E.P.M.; Lanctôt, N.; van Weeghel, J.

    2014-01-01

    Purpose Supported employment (SE) programs are evidence-based programs offered to people with severe mental illness to facilitate obtaining and keeping competitive work. However, significant variations in individuals’ vocational success may be partly explained by differences in their employment

  19. Defense Commissaries: Issues Related to the Sale of Electronic Scanner Data

    National Research Council Canada - National Science Library

    1998-01-01

    In response to your request that we review DeCA'S sale of scanner data and its implementation of category management, this report identifies DeCA'S total revenue from selling scanner data and compares license revenues...

  20. A new generation of PET scanners for small animal studies

    International Nuclear Information System (INIS)

    Hegyesi, G.; Imrek, J.; Kalinka, G.; Molnar, J.; Novak, D.; Valastyan, I.; Balkay, L.; Emri, M.; Kis, S.; Tron, L.

    2008-01-01

    Complete text of publication follows. Research on small animal PET scanners has been a hot topic in recent years. These devices are used in the preclinical phases of drug tests and during the development of new radiopharmaceuticals. They also provide a cost efficient way to test new materials, new design concepts and new technologies that later can be used to build more efficient human medical imaging devices. The development of a PET scanner requires expertise on different fields, therefore a consortium was formed that brought together Hungarian academic and industrial partners: the Nuclear Research Institute (which has experience in the development of nuclear detectors and data acquisition systems), the PET Center of the University of Debrecen (which has clinical experience in the application of nuclear imaging devices and background in image processing software), Mediso Ltd. (which has been developing, manufacturing, selling and servicing medical imaging devices since 1990) and other academic partners. This consortium has been working together since 2003: the knowledge base acquired during the development of our small animal PET scanners (miniPET-I and miniPET-II) is now being utilized to build a commercial multimodal human PET scanner. The operation of a PET scanner is based on the simultaneous detection ('coincidence') of two gamma photons originating from a positron annihilation. In traditional PET scanners coincidence is detected by a central unit during the measurement. In our system there is no such central module: all detected single gamma events are recorded (list mode data acquisition), and the list of events are processed using a computer cluster (built from PCs). The usage of independent detector modules and commercial components reduce both development and maintenance costs. Also, this mode of data acquisition is more suitable for development purposes, since once the data is collected and stored it can be used many times to test different signal

  1. Drilling Information System (DIS and Core Scanner

    Directory of Open Access Journals (Sweden)

    Ronald Conze

    2016-04-01

    Full Text Available The Drilling Information System is a modular structure of databases, tailored user applications as well as web services and instruments including appropriate interfaces to DIS. This tool set has been developed for geoscientific drilling projects but is applicable to other distributed scientific operations. The main focuses are the data acquisition on drill sites (ExpeditionDIS, and the curation of sample material e.g., in core repositories (CurationDIS. Due to the heterogeneity of scientific drilling projects, a project-specific DIS is arranged and adjusted from a collection of existing templates and modules according to the user requirements during a one week training course. The collected data are provided to the Science Team of the drilling project by secured Web services, and stored in long-term archives hosted at GFZ. At the end the data sets and sample material are documented in an Operational Report (e.g., Lorenz et al., 2015 and published with assigned DOI (Digital Object Identifier and IGSN (International Geo Sample Number; for physical samples by GFZ Data Services.

  2. A Computer-Controlled Laser Bore Scanner

    Science.gov (United States)

    Cheng, Charles C.

    1980-08-01

    This paper describes the design and engineering of a laser scanning system for production applications. The laser scanning techniques, the timing control, the logic design of the pattern recognition subsystem, the digital computer servo control for the loading and un-loading of parts, and the laser probe rotation and its synchronization will be discussed. The laser inspection machine is designed to automatically inspect the surface of precision-bored holes, such as those in automobile master cylinders, without contacting the machined surface. Although the controls are relatively sophisticated, operation of the laser inspection machine is simple. A laser light beam from a commercially available gas laser, directed through a probe, scans the entire surface of the bore. Reflected light, picked up through optics by photoelectric sensors, generates signals that are fed to a mini-computer for processing. A pattern recognition techniques program in the computer determines acceptance or rejection of the part being inspected. The system's acceptance specifications are adjustable and are set to the user's established tolerances. However, the computer-controlled laser system is capable of defining from 10 to 75 rms surface finish, and voids or flaws from 0.0005 to 0.020 inch. Following the successful demonstration with an engineering prototype, the described laser machine has proved its capability to consistently ensure high-quality master brake cylinders. It thus provides a safety improvement for the automotive braking system. Flawless, smooth cylinder bores eliminate premature wearing of the rubber seals, resulting in a longer-lasting master brake cylinder and a safer and more reliable automobile. The results obtained from use of this system, which has been in operation about a year for replacement of a tedious, manual operation on one of the high-volume lines at the Bendix Hydraulics Division, have been very satisfactory.

  3. Digital Data Matrix Scanner Developnent At Marshall Space Flight Center

    Science.gov (United States)

    2004-01-01

    Research at NASA's Marshall Space Flight Center has resulted in a system for reading hidden identification codes using a hand-held magnetic scanner. It's an invention that could help businesses improve inventory management, enhance safety, improve security, and aid in recall efforts if defects are discovered. Two-dimensional Data Matrix symbols consisting of letters and numbers permanently etched on items for identification and resembling a small checkerboard pattern are more efficient and reliable than traditional bar codes, and can store up to 100 times more information. A team led by Fred Schramm of the Marshall Center's Technology Transfer Department, in partnership with PRI,Torrance, California, has developed a hand-held device that can read this special type of coded symbols, even if covered by up to six layers of paint. Before this new technology was available, matrix symbols were read with optical scanners, and only if the codes were visible. This latest improvement in digital Data Matrix technologies offers greater flexibility for businesses and industries already using the marking system. Paint, inks, and pastes containing magnetic properties are applied in matrix symbol patterns to objects with two-dimensional codes, and the codes are read by a magnetic scanner, even after being covered with paint or other coatings. The ability to read hidden matrix symbols promises a wide range of benefits in a number of fields, including airlines, electronics, healthcare, and the automotive industry. Many industries would like to hide information on a part, so it can be read only by the party who put it there. For instance, the automotive industry uses direct parts marking for inventory control, but for aesthetic purposes the marks often need to be invisible. Symbols have been applied to a variety of materials, including metal, plastic, glass, paper, fabric and foam, on everything from electronic parts to pharmaceuticals to livestock. The portability of the hand

  4. A dedicated tool for PET scanner simulations using FLUKA

    International Nuclear Information System (INIS)

    Ortega, P.G.; Boehlen, T.T.; Cerutti, F.; Chin, M.P.W.; Ferrari, A.; Mancini, C.; Vlachoudis, V.; Mairani, A.; Sala, Paola R.

    2013-06-01

    Positron emission tomography (PET) is a well-established medical imaging technique. It is based on the detection of pairs of annihilation gamma rays from a beta+-emitting radionuclide, usually inoculated in the body via a biologically active molecule. Apart from its wide-spread use for clinical diagnosis, new applications are proposed. This includes notably the usage of PET for treatment monitoring of radiation therapy with protons and ions. PET is currently the only available technique for non-invasive monitoring of ion beam dose delivery, which was tested in several clinical pilot studies. For hadrontherapy, the distribution of positron emitters, produced by the ion beam, can be analyzed to verify the correct treatment delivery. The adaptation of previous PET scanners to new environments and the necessity of more precise diagnostics by better image quality triggered the development of new PET scanner designs. The use of Monte Carlo (MC) codes is essential in the early stages of the scanner design to simulate the transport of particles and nuclear interactions from therapeutic ion beams or radioisotopes and to predict radiation fields in tissues and radiation emerging from the patient. In particular, range verification using PET is based on the comparison of detected and simulated activity distributions. The accuracy of the MC code for the relevant physics processes is obviously essential for such applications. In this work we present new developments of the physics models with importance for PET monitoring and integrated tools for PET scanner simulations for FLUKA, a fully-integrated MC particle-transport code, which is widely used for an extended range of applications (accelerator shielding, detector and target design, calorimetry, activation, dosimetry, medical physics, radiobiology, ...). The developed tools include a PET scanner geometry builder and a dedicated scoring routine for coincident event determination. The geometry builder allows the efficient

  5. Coastal zone color scanner ``system calibration'': A retrospective examination

    Science.gov (United States)

    Evans, Robert H.; Gordon, Howard R.

    1994-04-01

    During its lifetime the coastal zone color scanner (CZCS) produced approximately 66,000 images. These have been placed in an archive of "raw" radiance (sensor counts) in a subsampled format that is easily accessible. They have also been processed to form global fields, at reduced resolution, of normalized water-leaving radiance, phytoplankton pigments, and diffuse attenuation coefficient. Using this archive, we have tried to characterize some aspects of the "system calibration" for the 8-year lifetime of CZCS. Specifically, we have assumed that the sensitivity of the red band decayed in a simple manner similar to the well-known long-term degradation of the shorter-wavelength bands, and we examined the sensitivity of the green and yellow bands by computing the globally averaged water-leaving radiance, over 10-day periods, for all of the imagery. The results provide evidence that in addition to the long-term degradation, short-term (2 weeks to 1 month) variations in the radiometric sensitivity of these bands started in early fall 1981 and continued for the rest of the mission. In contrast, the data suggest the absence of such variations prior to August 1981. It is reasonable to believe that the sensitivity of the blue (and probably the red) band underwent such variations as well; however, our methodology cannot be used to study the other bands. Thus after these fluctuations began, the actual values of CZCS-estimated pigment concentrations at a given location should be viewed with skepticism; however, the global patterns of derived pigment concentration should be valid. Had an extensive set of surface measurements of water-leaving radiance, e.g., from moored buoys or drifters, been available during the CZCS mission, these fluctuations could have been removed from the data set, and this would have greatly increased its value. The lessons learned from CZCS, that is, the requirement of good radiometric calibration and stability and the necessity of "sea truth" stations

  6. Coastal zone color scanner 'system calibration': A retrospective examination

    Science.gov (United States)

    Evans, Robert H.; Gordon, Howard R.

    1994-01-01

    During its lifetime the Coastal Zone Color Scanner (CZCS) produced approximately 66,000 images. These have been placed in an archive of 'raw' radiance (sensor counts) in a subsampled format that is easily accessible. They have also been processed to form global fields, at reduced resolution, of normalized water-leaving radiance, phytoplankton pigments, and diffuse attenuation coefficient. Using this archive, we have tried to characterize some aspects of the 'system calibration' for the 8-year lifetime of CZCS. Specifically, we have assumed that the sensitivity of the red band decayed in a simple manner similar to the well-known long-term degradation of the shorter-wavelength bands, and we examined the sensitivity of the green and yellow bands by computing the globally averaged water-leaving radiance, over 10-day periods, for all of the imagery. The results provided evidence that in addition to the long-term degradation, short-term (2 weeks to 1 month) variations in the radiometric sensitivity of these bands started in early fall 1981 and continued for the rest of the mission. In contrast, the data suggested the absence of such variations prior to August 1981. It is reasonable to believe that the sensitivity of the blue (and probably the red) band underwent such variations as well; however our methodology cannot be used to study the other bands. Thus, after these fluctuations began, the actual values of CZCS - estimated pigment concentrations at a given location should be viewed with skepticism; however, the global patterns of derived pigment concentrations should be valid. Had an extensive set of surface measurements of water-leaving radiance, e.r., from moored buoyes or drifters, had been available during the CZCS mission, these fluctuations could have been removed from the data set, and this would have greatly increased its value. The lessons learned from CZCS that is, the requirement of good radiometric calibration and stability and the necessity of 'sea truth

  7. Global Positioning Radiometric Scanner System. Innovative Technology Summary Report

    International Nuclear Information System (INIS)

    2001-01-01

    The US DOE continually seeks safer and more cost-effective technologies for use in decontamination and decommissioning (D and D) of nuclear facilities. To this end, the Deactivation and Decommissioning Focus Area (DDFA) of the DOE OST sponsors the Large Scale Demonstration and Deployment Projects (LSDDP). At these LSDDPs, developers and vendors of improved or innovative technologies showcase products that are potentially beneficial to the DOE projects and to others in the D and D community. Benefits sought include decreased health and safety risks to personnel and the environment, increased productivity, and decreased costs of operation. The Idaho National Engineering and Environmental Laboratory (INEEL) LSDDP generated a list of statements defining specific needs or problems where improved technology could be incorporated into ongoing D and D tasks. One of the stated needs was for developing technologies that would reduce costs and shorten DDOE/EM--0552DOE/EM--0552 and D schedules by providing radiological characterizations to meet the free-release criteria. The Global Positioning Radiometric Scanner (GPRS system shown in Figure 1) utilizes a detection system; a portable computer, a differential global positioning system (d-gps), and a four wheel drive vehicle. Once the survey data has been collected, a software program called GeoSofttrademark generates a graphical representation of the radiological contamination extent. Baseline technology involves gridding the area and hand surveying each grid. This demonstration investigated the associated costs and the required time to evaluate the radiological characterization data from the GPRS with respect to the baseline technology. The GPRS system performs in-situ, real-time analyses to identify the extent of radiological contamination. Benefits expected from using the new innovative technology (GPRS) include: Reduced labor hours associated with performing the survey; Increased number of survey data points; Reduced

  8. A Cost Effective Multi-Spectral Scanner for Natural Gas Detection

    Energy Technology Data Exchange (ETDEWEB)

    Yudaya Sivathanu; Jongmook Lim; Vinoo Narayanan; Seonghyeon Park

    2005-12-07

    The objective of this project is to design, fabricate and demonstrate a cost effective, multi-spectral scanner for natural gas leak detection in transmission and distribution pipelines. During the first year of the project, a laboratory version of the multi-spectral scanner was designed, fabricated, and tested at EnUrga Inc. The multi-spectral scanner was also evaluated using a blind Department of Energy study at the Rocky Mountain Oilfield Testing Center. The performance of the scanner was inconsistent during the blind study. However, most of the leaks were outside the view of the multi-spectral scanner that was developed during the first year of the project. Therefore, a definite evaluation of the capability of the scanner was not obtained. Despite the results, sufficient number of plumes was detected fully confirming the feasibility of the multi-spectral scanner. During the second year, the optical design of the scanner was changed to improve the sensitivity of the system. Laboratory tests show that the system can reliably detect small leaks (20 SCFH) at 30 to 50 feet. A prototype scanner was built and evaluated during the second year of the project. Only laboratory evaluations were completed during the second year. The laboratory evaluations show the feasibility of using the scanner to determine natural gas pipeline leaks. Further field evaluations and optimization of the scanner are required before commercialization of the scanner can be initiated.

  9. Addressing Spatial Variability of Surface-Layer Wind with Long-Range WindScanners

    DEFF Research Database (Denmark)

    Berg, Jacob; Vasiljevic, Nikola; Kelly, Mark C.

    2015-01-01

    of the WindScanner data is high, although the fidelity of the estimated vertical velocity component is significantly limited by the elevation angles of the scanner heads. The system of long-range WindScanners presented in this paper is close to being fully operational, with the pilot study herein serving...

  10. Impiego della tecnologia laser scanner su mezzo mobile terrestre per il city modelling

    Directory of Open Access Journals (Sweden)

    Giorgio Vassena

    2009-03-01

    Full Text Available Use of laser scanner on mobile equipment for city modellingThe use of GPS/INS systems on mobile instrumental equipment for 3D city modelling is more and more widespread as advanced technology of survey. These systems offer good versatility, even if with some problems linked to urban canyon and to the drift of inertial systems.In urban contest it seems also profitable the employmentof classical topographic equipment for surveying of position of mobile mean in the 3D and colour data acquisition phase. This technology, easy to use, guarantees a good efficacy on urban scale and accuracies of alignment comparable to those of consolidated technology. The employment of equipment commonly available from operators makes the method proposed economically favourable, results being equal.

  11. The Traveling Optical Scanner – Case Study on 3D Shape Models of Ancient Brazilian Skulls

    DEFF Research Database (Denmark)

    Trinderup, Camilla Himmelstrup; Dahl, Vedrana Andersen; Gregersen, Kristian Murphy

    2016-01-01

    , inoffensive and inexpensive 3D scanning modality based on structured light, suitable for capturing the morphology and the appearance of specimens. Benefits of having 3D models are manifold. The 3D models are easy to share among researchers and can be made available to the general public. Advanced...... morphological modelling is possible with accurate description of the specimens provided by the models. Furthermore, performing studies on models reduces the risk of damage to the original specimen. In our work we employ a high resolution structured light scanner for digitalizing a collection of 8500 year old...... human skulls from Brazil. To evaluate the precision of our setup we compare the structured light scan to micro-CT and achieve submillimetre difference. We analyse morphological features of the Brazilian skulls using manual landmarks, but a research goal is to automate this, fully utilize the dense 3D...

  12. The determination of the volume of the thyroid gland by a new ultrasonic scanner

    International Nuclear Information System (INIS)

    Yokoyama, Naokata; Izumi, Motomori; Nagataki, Shigenobu; Hazama, Ryuji; Kurata, Akihiko; Ishikawa, Naofumi; Ito, Kunihiko.

    1984-01-01

    A newly developed high-resolution ultrasonic scanner for determining the volume of the thyroid gland was employed in 1983's health screening for A-bomb survivors in Nishiyama district (Nagasaki), and effects of radiation on the thyroid gland were examined. Thirty-one inhabitants who have been living in Nishiyama district since the A-bombing were selected as subjects (Nishiyama group) and their sex- and age-matched persons were selected as controls (control group). Regarding the incidence of chronic thyroiditis, Graves' disease, thyroid adenoma, and hypothyroidism, there was no significant difference between the groups. The volume of the thyroid gland was 14.6+-6.2 ml in the Nishiyama group and 13.1+-4.0 ml in the control group; the average volume of the thyroid gland was a little higher in the Nishiyama group than in the control group, but this was not statistically significant. (Namekawa, K.)

  13. The measurement of employment benefits

    International Nuclear Information System (INIS)

    Burtraw, D.

    1994-01-01

    The consideration of employment effects and so-called 'hidden employment benefits' is one of the most confused and contentious issues in benefit-cost analysis and applied welfare economics generally. New investments create new employment opportunities, and often advocates for specific investments cite these employment opportunities as alleged benefits associated with the project. Indeed, from the local perspective, such employment opportunities may appear to be beneficial because they appear to come for free. If there is unemployment in the local area, then new investments create valuable employment opportunities for those in the local community. Even if there is full employment in the local area then new investments create incentives for immigrant from other locations that may have pecuniary benefits locally through increased property values, business revenues, etc. The focus in this study is on net economic benefits from a broad national perspective. From this perspective, many of the alleged employment benefits at the local level are offset by lost benefits at other locales, and do not count as benefits according to economic theory. This paper outlines a methodology for testing this rebuttable presumption with empirical data pertaining to labor markets that would be affected by a specific new investment. The theoretical question that is relevant is whether the social opportunity cost of new employment is less than the market wage. This would be the case, for example, if one expects unemployment or underemployment to persist in a specific region of the economy or occupational category affected by the new investment. In this case, new employment opportunities produce a net increase in social wealth rather than just a transfer of income

  14. The measurement of employment benefits

    Energy Technology Data Exchange (ETDEWEB)

    Burtraw, D

    1994-07-01

    The consideration of employment effects and so-called 'hidden employment benefits' is one of the most confused and contentious issues in benefit-cost analysis and applied welfare economics generally. New investments create new employment opportunities, and often advocates for specific investments cite these employment opportunities as alleged benefits associated with the project. Indeed, from the local perspective, such employment opportunities may appear to be beneficial because they appear to come for free. If there is unemployment in the local area, then new investments create valuable employment opportunities for those in the local community. Even if there is full employment in the local area then new investments create incentives for immigrant from other locations that may have pecuniary benefits locally through increased property values, business revenues, etc. The focus in this study is on net economic benefits from a broad national perspective. From this perspective, many of the alleged employment benefits at the local level are offset by lost benefits at other locales, and do not count as benefits according to economic theory. This paper outlines a methodology for testing this rebuttable presumption with empirical data pertaining to labor markets that would be affected by a specific new investment. The theoretical question that is relevant is whether the social opportunity cost of new employment is less than the market wage. This would be the case, for example, if one expects unemployment or underemployment to persist in a specific region of the economy or occupational category affected by the new investment. In this case, new employment opportunities produce a net increase in social wealth rather than just a transfer of income.

  15. Results of a comparison study using tomographic and segmented gamma scanner technology

    International Nuclear Information System (INIS)

    Hurd, J.R.; Estep, R.J.; Dittrich, S.; Grimes, L.V.; Gomez, C.D.

    2004-01-01

    In order to support the many on-going research and programmatic activities at Los Alamos Plutonium and Chemistry and Metallurgy Research (CMR) Facilities in as accurate, efficient, and cost-effective manner possible, every reasonable effort is made to equip the nondestructive assay (NDA) laboratories with the most modern and technologically advanced instrumentation available. Recently, new state-of-the-art tomographic gamma scanner (TGS) instruments were installed to replace aging and outmoded segmented gamma scanner (SGS) instruments. Through the implementation of a translation axis, in addition to the vertical and rotation axes of the SGS, the TGS technique is able to employ axial tomography to determine the spatial distribution and quantity of nuclear material using high-resolution gamma-ray spectroscopy. Because the attenuation matrix and source distributions are known more accurately than with the SGS technology, biases due to matrix and source distributions should be reduced. In principle, a single calibration should suffice for the determination of isotopic mass for a wide range of material and matrix types. A number of questions naturally arise concerning these purported advantages of the TGS. Perhaps the most fundamental of these is to understand how the TGS measurement results compare with those of a typical SGS on the same well-characterized standards differing in matrix and material type. To that end, the TGS operating parameters were optimized to assay 55-gallon drum waste identical to that measured by our SGS. The calibration and measurement results on these standards, placed in typical low-density waste matrices, are presented and discussed. These results should enable more confident use of the TGS as well as point the way toward even more studies to enable more effective employment of the new TGS technology.

  16. Digital dental surface registration with laser scanner for orthodontics set-up planning

    Science.gov (United States)

    Alcaniz-Raya, Mariano L.; Albalat, Salvador E.; Grau Colomer, Vincente; Monserrat, Carlos A.

    1997-05-01

    We present an optical measuring system based on laser structured light suitable for its diary use in orthodontics clinics that fit four main requirements: (1) to avoid use of stone models, (2) to automatically discriminate geometric points belonging to teeth and gum, (3) to automatically calculate diagnostic parameters used by orthodontists, (4) to make use of low cost and easy to use technology for future commercial use. Proposed technique is based in the use of hydrocolloids mould used by orthodontists for stone model obtention. These mould of the inside of patient's mouth are composed of very fluent materials like alginate or hydrocolloids that reveal fine details of dental anatomy. Alginate mould are both very easy to obtain and very low costly. Once captured, alginate moulds are digitized by mean of a newly developed and patented 3D dental scanner. Developed scanner is based in the optical triangulation method based in the projection of a laser line on the alginate mould surface. Line deformation gives uncalibrated shape information. Relative linear movements of the mould with respect to the sensor head gives more sections thus obtaining a full 3D uncalibrated dentition model. Developed device makes use of redundant CCD in the sensor head and servocontrolled linear axis for mould movement. Last step is calibration to get a real and precise X, Y, Z image. All the process is done automatically. The scanner has been specially adapted for 3D dental anatomy capturing in order to fulfill specific requirements such as: scanning time, accuracy, security and correct acquisition of 'hidden points' in alginate mould. Measurement realized on phantoms with known geometry quite similar to dental anatomy present errors less than 0,1 mm. Scanning of global dental anatomy is 2 minutes, and generation of 3D graphics of dental cast takes approximately 30 seconds in a Pentium-based PC.

  17. A new crystal whole-body scanner for positron emitters

    International Nuclear Information System (INIS)

    Ostertag, H.; Kuebler, W.; Kubesch, R.; Lorenz, W.J.; Woerner, P.

    1980-01-01

    A multicrystal whole body scanner for positron emitters has been constructed. The annihilation quanta are measured in two opposing detector banks. Each detector bank consists of 64 NaI crystals of 1.5'' diameter x 3'' length. Directly opposing single detectors are in coincidence. The patient moves linearly between the stationary transverse detector banks. The scanning area of the system is 64 x 192 cm 2 . The spatial resolution is 2 cm at a sampling distance of 1 cm. The sensitivity is 6400 counts/s for a pure positron flood source with 1 μCi/cm 2 . The system is controlled by a microcomputer (DEC LSI-11). The scintigrams are shown on a display. Absolute activities can be calculated by mathematical comparison of consecutive emission and transmission scans. The design of the positron scanner and its capacibilities are described. Experimental and initial clinical results are presented. (author)

  18. Beam Dumping Ghost Signals in Electric Sweep Scanners

    International Nuclear Information System (INIS)

    Stockli, M.P.; Leitner, M.; Keller, R.; Moehs, D.P.; Welton, R.F.

    2005-01-01

    Over the last 20 years many labs started to use Allison scanners to measure low-energy ion beam emittances. We show that large trajectory angles produce ghost signals due to the impact of the beamlet on the electric deflection plates. The strength of the ghost signal is proportional to the amount of beam entering the scanner. Depending on the ions and their velocity, ghost signals can have the opposite polarity as the main beam signals or the same polarity. These ghost signals are easily overlooked because they partly overlap the real signals, they are mostly below the 1% level, and they are often hidden in the noise. However, they cause significant errors in emittance estimates because they are associated with large trajectory angles. The strength of ghost signals, and the associated errors, can be drastically reduced with a simple modification of the deflection plates

  19. Beam dumping ghost signals in electric sweep scanners

    International Nuclear Information System (INIS)

    Stockli, M.P.; SNS Project, Oak Ridge; Tennessee U.; Leitner, M.; LBL, Berkeley; Moehs, D.P.; Keller, R.; LBL, Berkeley; Welton, R.F.; SNS Project, Oak Ridge

    2004-01-01

    Over the last 20 years many labs started to use Allison scanners to measure loW--energy ion beam emittances. We show that large trajectory angles produce ghost signals due to the impact of the beamlet on the electric deflection plates. The strength of the ghost signal is proportional to the amount of beam entering the scanner. Depending on the ions and their velocity, ghost signals can have the opposite polarity as the main beam signals or the same polarity. These ghost signals are easily overlooked because they partly overlap the real signals, they are mostly below the 1% level, and they are often hidden in the noise. However, they cause significant errors in emittance estimates because they are associated with large trajectory angles. The strength of ghost signals, and the associated errors, can be drastically reduced with a simple modification of the deflection plates

  20. Wire Scanner Beam Profile Measurements: LANSCE Facility Beam Development

    International Nuclear Information System (INIS)

    Gilpatrick, John D.; Batygin, Yuri K.; Gonzales, Fermin; Gruchalla, Michael E.; Kutac, Vincent G.; Martinez, Derwin; Sedillo, James Daniel; Pillai, Chandra; Rodriguez Esparza, Sergio; Smith, Brian G.

    2012-01-01

    The Los Alamos Neutron Science Center (LANSCE) is replacing Wire Scanner (WS) beam profile measurement systems. Three beam development tests have taken place to test the new wire scanners under beam conditions. These beam development tests have integrated the WS actuator, cable plant, electronics processors and associated software and have used H - beams of different beam energy and current conditions. In addition, the WS measurement-system beam tests verified actuator control systems for minimum profile bin repeatability and speed, checked for actuator backlash and positional stability, tested the replacement of simple broadband potentiometers with narrow band resolvers, and tested resolver use with National Instruments Compact Reconfigurable Input and Output (cRIO) Virtual Instrumentation. These beam tests also have verified how trans-impedance amplifiers react with various types of beam line background noise and how noise currents were not generated. This paper will describe these beam development tests and show some resulting data.

  1. Wire Scanner Beam Profile Measurements: LANSCE Facility Beam Development

    Energy Technology Data Exchange (ETDEWEB)

    Gilpatrick, John D. [Los Alamos National Laboratory; Batygin, Yuri K. [Los Alamos National Laboratory; Gonzales, Fermin [Los Alamos National Laboratory; Gruchalla, Michael E. [Los Alamos National Laboratory; Kutac, Vincent G. [Los Alamos National Laboratory; Martinez, Derwin [Los Alamos National Laboratory; Sedillo, James Daniel [Los Alamos National Laboratory; Pillai, Chandra [Los Alamos National Laboratory; Rodriguez Esparza, Sergio [Los Alamos National Laboratory; Smith, Brian G. [Los Alamos National Laboratory

    2012-05-15

    The Los Alamos Neutron Science Center (LANSCE) is replacing Wire Scanner (WS) beam profile measurement systems. Three beam development tests have taken place to test the new wire scanners under beam conditions. These beam development tests have integrated the WS actuator, cable plant, electronics processors and associated software and have used H{sup -} beams of different beam energy and current conditions. In addition, the WS measurement-system beam tests verified actuator control systems for minimum profile bin repeatability and speed, checked for actuator backlash and positional stability, tested the replacement of simple broadband potentiometers with narrow band resolvers, and tested resolver use with National Instruments Compact Reconfigurable Input and Output (cRIO) Virtual Instrumentation. These beam tests also have verified how trans-impedance amplifiers react with various types of beam line background noise and how noise currents were not generated. This paper will describe these beam development tests and show some resulting data.

  2. Linac beam core modeling from wire-scanner data

    International Nuclear Information System (INIS)

    Law, A.G.

    1977-08-01

    This study introduces mathematical modeling of accelerator beams from data collected by wire scanners. Details about a beam core D(x,x',y,y') are examined in several situations: (a) for a discretization of the projection into xy-space, a maximum-entropy solution and a minimum-norm solution are developed and discussed, (b) for undiscretized xy-subspace, a two-dimensional Gaussian approximation D(x,.,y,.) = a exp [α(x-x 0 ) 2 + β(x-x 0 )(y-y 0 ) + γ(y-y 0 ) 2 ] is obtained by least squares, and (c) for four-dimensional space, the fit of a single Gaussian to data from a succession of wire scanners is investigated

  3. Shielding design for testing room of large container scanner

    International Nuclear Information System (INIS)

    Liu Yisi; Miao Qitian; Zhou Liye

    1997-01-01

    Testing facility for large container scanner is a most advanced anti-smuggle tool. The X-ray scanning principle is adopted in this system. The X-ray was collimated a ted as a fan-shape beam. The accelerator only supplies the ray beam when the container is scanned. The irradiation time is less than one minute per test. The X-ray burst irradiation and highly collimated a ted scanning beam of this system is different from the common industrial irradiation accelerator. The shielding design of the 1:1 large container scanner introduced has better collimation level because of tri-collimation. The irradiation dose is less than 150 μGy per test, which is obviously lower than importations

  4. Robust Object Segmentation Using a Multi-Layer Laser Scanner

    Science.gov (United States)

    Kim, Beomseong; Choi, Baehoon; Yoo, Minkyun; Kim, Hyunju; Kim, Euntai

    2014-01-01

    The major problem in an advanced driver assistance system (ADAS) is the proper use of sensor measurements and recognition of the surrounding environment. To this end, there are several types of sensors to consider, one of which is the laser scanner. In this paper, we propose a method to segment the measurement of the surrounding environment as obtained by a multi-layer laser scanner. In the segmentation, a full set of measurements is decomposed into several segments, each representing a single object. Sometimes a ghost is detected due to the ground or fog, and the ghost has to be eliminated to ensure the stability of the system. The proposed method is implemented on a real vehicle, and its performance is tested in a real-world environment. The experiments show that the proposed method demonstrates good performance in many real-life situations. PMID:25356645

  5. A Novel Atomic Force Microscope with Multi-Mode Scanner

    International Nuclear Information System (INIS)

    Qin, Chun; Zhang, Haijun; Xu, Rui; Han, Xu; Wang, Shuying

    2016-01-01

    A new type of atomic force microscope (AFM) with multi-mode scanner is proposed. The AFM system provides more than four scanning modes using a specially designed scanner with three tube piezoelectric ceramics and three stack piezoelectric ceramics. Sample scanning of small range with high resolution can be realized by using tube piezos, meanwhile, large range scanning can be achieved by stack piezos. Furthermore, the combination with tube piezos and stack piezos not only realizes high-resolution scanning of small samples with large- scale fluctuation structure, but also achieves small range area-selecting scanning. Corresponding experiments are carried out in terms of four different scanning modes showing that the AFM is of reliable stability, high resolution and can be widely applied in the fields of micro/nano-technology. (paper)

  6. Enhanced methodology of focus control and monitoring on scanner tool

    Science.gov (United States)

    Chen, Yen-Jen; Kim, Young Ki; Hao, Xueli; Gomez, Juan-Manuel; Tian, Ye; Kamalizadeh, Ferhad; Hanson, Justin K.

    2017-03-01

    As the demand of the technology node shrinks from 14nm to 7nm, the reliability of tool monitoring techniques in advanced semiconductor fabs to achieve high yield and quality becomes more critical. Tool health monitoring methods involve periodic sampling of moderately processed test wafers to detect for particles, defects, and tool stability in order to ensure proper tool health. For lithography TWINSCAN scanner tools, the requirements for overlay stability and focus control are very strict. Current scanner tool health monitoring methods include running BaseLiner to ensure proper tool stability on a periodic basis. The focus measurement on YIELDSTAR by real-time or library-based reconstruction of critical dimensions (CD) and side wall angle (SWA) has been demonstrated as an accurate metrology input to the control loop. The high accuracy and repeatability of the YIELDSTAR focus measurement provides a common reference of scanner setup and user process. In order to further improve the metrology and matching performance, Diffraction Based Focus (DBF) metrology enabling accurate, fast, and non-destructive focus acquisition, has been successfully utilized for focus monitoring/control of TWINSCAN NXT immersion scanners. The optimal DBF target was determined to have minimized dose crosstalk, dynamic precision, set-get residual, and lens aberration sensitivity. By exploiting this new measurement target design, 80% improvement in tool-to-tool matching, >16% improvement in run-to-run mean focus stability, and >32% improvement in focus uniformity have been demonstrated compared to the previous BaseLiner methodology. Matching control and monitoring on multiple illumination conditions, opens an avenue to significantly reduce Focus-Exposure Matrix (FEM) wafer exposure for new product/layer best focus (BF) setup.

  7. Automatic inventory of components by laser 3D scanner

    International Nuclear Information System (INIS)

    Rodriguez Garcia, R.; Munoz Prieto, C.; Sarti Fernandez, F.

    2014-01-01

    One of the existing needs in nuclear decommissioning projects is to provide an inventory of components to be dismantled, which is available from its spatial location and elements that exist in your environment. The Laser scanner technology is a system of data acquisition that allows 3D models composed of millions of points, it's models with pinpoint accuracy and are available in a very short space of time. (Author)

  8. Concrete hardened characterization using table scanner and microtomography computed

    International Nuclear Information System (INIS)

    Wilson, R.E.; Pessoa, J.R.; Assis, J.T. de; Dominguez, D.S.; Dias, L.A.; Santana, M. R.

    2016-01-01

    This paper proposes the use of image processing technologies to analyze hardened concrete samples obtained from table scanner and micro tomography. Techniques will be used to obtain numerical data on the distribution and geometry of aggregates and pores of the concrete, as well as their relative position. It is expected that the data obtained can produce information on the research of concrete pathologies such as AAR, and the freeze / thaw process. (author)

  9. Ultrasonic scanner for stainless steel weld inspections. [LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Kupperman, D. S.; Reimann, K. J.

    1978-09-01

    The large grain size and anisotropic nature of stainless steel weld metal make conventional ultrasonic testing very difficult. A technique is evaluated for minimizing the coherent ultrasonic noise in stainless steel weld metal. The method involves digitizing conventional ''A-scan'' traces and averaging them with a minicomputer. Results are presented for an ultrasonic scanner which interrogates a small volume of the weld metal while averaging the coherent ultrasonic noise.

  10. Design of a laser scanner for a digital mammography system.

    Science.gov (United States)

    Rowlands, J A; Taylor, J E

    1996-05-01

    We have developed a digital readout system for radiographic images using a scanning laser beam. In this system, electrostatic charge images on amorphous selenium (alpha-Se) plates are read out using photo-induced discharge (PID). We discuss the design requirements of a laser scanner for the PID system and describe its construction from commercially available components. The principles demonstrated can be adapted to a variety of digital imaging systems.

  11. Accuracy of five intraoral scanners compared to indirect digitalization.

    Science.gov (United States)

    Güth, Jan-Frederik; Runkel, Cornelius; Beuer, Florian; Stimmelmayr, Michael; Edelhoff, Daniel; Keul, Christine

    2017-06-01

    Direct and indirect digitalization offer two options for computer-aided design (CAD)/ computer-aided manufacturing (CAM)-generated restorations. The aim of this study was to evaluate the accuracy of different intraoral scanners and compare them to the process of indirect digitalization. A titanium testing model was directly digitized 12 times with each intraoral scanner: (1) CS 3500 (CS), (2) Zfx Intrascan (ZFX), (3) CEREC AC Bluecam (BLU), (4) CEREC AC Omnicam (OC) and (5) True Definition (TD). As control, 12 polyether impressions were taken and the referring plaster casts were digitized indirectly with the D-810 laboratory scanner (CON). The accuracy (trueness/precision) of the datasets was evaluated by an analysing software (Geomagic Qualify 12.1) using a "best fit alignment" of the datasets with a highly accurate reference dataset of the testing model, received from industrial computed tomography. Direct digitalization using the TD showed the significant highest overall "trueness", followed by CS. Both performed better than CON. BLU, ZFX and OC showed higher differences from the reference dataset than CON. Regarding the overall "precision", the CS 3500 intraoral scanner and the True Definition showed the best performance. CON, BLU and OC resulted in significantly higher precision than ZFX did. Within the limitations of this in vitro study, the accuracy of the ascertained datasets was dependent on the scanning system. The direct digitalization was not superior to indirect digitalization for all tested systems. Regarding the accuracy, all tested intraoral scanning technologies seem to be able to reproduce a single quadrant within clinical acceptable accuracy. However, differences were detected between the tested systems.

  12. Wire scanner data analysis for the SSC Linac emittance measurement

    International Nuclear Information System (INIS)

    Yao, C.Y.; Hurd, J.W.; Sage, J.

    1993-07-01

    The wire scanners are designed in the SSC Linac for measurement of beam emittance at various locations. In order to obtain beam parameters from the scan signal, a data analysis program was developed that considers the problems of noise reduction, machine modeling, parameter fitting, and correction. This program is intended as a tool for Linac commissioning and also as part of the Linac control program. Some of the results from commissioning runs are presented

  13. Authenticity in Employment Relations

    DEFF Research Database (Denmark)

    Tackney, Charles Thomas

    This research takes up the concept of authenticity as a criterion variable for theology of the workplace analysis, a domain which explores employment parameters in light of religious teaching on the social question at national, organizational or firm-specific levels. Following a review of the con......This research takes up the concept of authenticity as a criterion variable for theology of the workplace analysis, a domain which explores employment parameters in light of religious teaching on the social question at national, organizational or firm-specific levels. Following a review...... of the concept in Western culture, philosophy, and management studies, Religious Society of Friends (Quaker) and Roman Catholic social teachings are investigated for positively correlative data to help develop the criterion variable. From the literature review of concept and historical data in both traditions...... analysis should complement and support corporate social responsibility, management spirituality, authentic leadership / authentic follower, and other secular research by offering a research methods bridge between empirically grounded theology and secular studies, with the common goal of improving workplace...

  14. Building Employer Capacity to Support Meaningful Employment for Persons with Developmental Disabilities: A Grounded Theory Study of Employment Support Perspectives.

    Science.gov (United States)

    Rashid, Marghalara; Hodgetts, Sandra; Nicholas, David

    2017-11-01

    To explore strategies to build employer capacity to support people with DD in meaningful employment from perspective of employment support workers. A grounded theory study was conducted with 34 employment support individuals. A theoretical sampling approach was used to identify and recruit participants from multiple sites in Ontario and Alberta. Three main themes, with seven sub-themes, emerged: (1) experiences of supporting employment finding for people with DD, (2) institutional influences on employee experiences, and (3) attitudes, assumptions and stigma. Several recommendations related to building employer capacity were offered. Our findings provide insight on specific elements and strategies that can support building employer capacity for persons with DD.

  15. Determining the surface roughness coefficient by 3D Scanner

    Directory of Open Access Journals (Sweden)

    Karmen Fifer Bizjak

    2010-12-01

    Full Text Available Currently, several test methods can be used in the laboratory to determine the roughness of rock joint surfaces.However, true roughness can be distorted and underestimated by the differences in the sampling interval of themeasurement methods. Thus, these measurement methods produce a dead zone and distorted roughness profiles.In this paper a new rock joint surface roughness measurement method is presented, with the use of a camera-typethree-dimensional (3D scanner as an alternative to current methods. For this study, the surfaces of ten samples oftuff were digitized by means of a 3D scanner, and the results were compared with the corresponding Rock JointCoefficient (JRC values. Up until now such 3D scanner have been mostly used in the automotive industry, whereastheir use for comparison with obtained JRC coefficient values in rock mechanics is presented here for the first time.The proposed new method is a faster, more precise and more accurate than other existing test methods, and is apromising technique for use in this area of study in the future.

  16. Quality assurance of computed tomography scanner beams in diagnostic radiology

    International Nuclear Information System (INIS)

    Lindskoug, B.A.

    1989-01-01

    The number of computed tomography (CT) scanners in diagnostic radiology is increasing, to the extent that they are now found in relatively small hospitals. These hospitals do not have local physicists available and so methods must be developed to allow quality assurance to be carried out at distant laboratories. Several different types of solid water phantoms are available with various built-in test objects that may supply sufficient information about the many parameters that must be checked. The dose distributions, however, are usually not so well considered, although the connection between image quality and absorbed dose must be known for optimal use of a CT scanner. By introducing thermoluminescent dosemeters (TLDs) into a commercial phantom (RMI), it was possible to measure the absorbed dose profile and the line integral of the absorbed dose across the slit. The computer-guided readout of the TLDs gives the absorbed dose, the average dose and half maximum width, absorbed dose curve, and also the line integral of the peak. The only modification of the phantom was five holes, drilled at strategic positions, that did not influence the built-in test objects. This single measurement provides an appropriate monthly quality assurance check of the CT scanner with little extra effort. (author)

  17. Erosion can't hide from laser scanner

    International Nuclear Information System (INIS)

    Konstant, D.A.

    1991-01-01

    Particles of topsoil blown by wind will bounce along the soil surface and finally escape a field, leaving it less able to support crops. Water will wash away valuable topsoil and nutrients. And how rough the soil surface is influences whether the soil will erode. Until now, soil scientists have had no suitable technique to measure soil roughness - or microtopography - on the small scale. ARS soil scientists Joe M. Bradford and Chi-hua Huang, of the National Soil Erosion Research Laboratory in West Lafayette, Indiana, have developed a portable scanner that can. It measures the tiny ridges left in the soil by tilling or clods of soil particles that clump together naturally. What does the scanner do? It measures soil elevation by shining a low-power laser beam onto the surface and detecting the position of the laser spot reflected from the soil with a 35-mm camera. In place of film, the scanner camera uses electronic circuitry somewhat similar to that in a video camera to transmit the spot's position to a small computer about 30,000 times a minute. The laser and camera are mounted on the frame of a motor-driven carriage. The computer controls the carriage movement. At the end of a scan, a microtopographic map is stored in the computer. Scientists can analyze it immediately and can compare it to previous maps to see whether erosion has occurred

  18. Advanced optical 3D scanners using DMD technology

    Science.gov (United States)

    Muenstermann, P.; Godding, R.; Hermstein, M.

    2017-02-01

    Optical 3D measurement techniques are state-of-the-art for highly precise, non-contact surface scanners - not only in industrial development, but also in near-production and even in-line configurations. The need for automated systems with very high accuracy and clear implementation of national precision standards is growing extremely due to expanding international quality guidelines, increasing production transparency and new concepts related to the demands of the fourth industrial revolution. The presentation gives an overview about the present technical concepts for optical 3D scanners and their benefit for customers and various different applications - not only in quality control, but also in design centers or in medical applications. The advantages of DMD-based systems will be discussed and compared to other approaches. Looking at today's 3D scanner market, there is a confusing amount of solutions varying from lowprice solutions to high end systems. Many of them are linked to a very special target group or to special applications. The article will clarify the differences of the approaches and will discuss some key features which are necessary to render optical measurement systems suitable for industrial environments. The paper will be completed by examples for DMDbased systems, e. g. RGB true-color systems with very high accuracy like the StereoScan neo of AICON 3D Systems. Typical applications and the benefits for customers using such systems are described.

  19. TH-C-18A-06: Combined CT Image Quality and Radiation Dose Monitoring Program Based On Patient Data to Assess Consistency of Clinical Imaging Across Scanner Models

    Energy Technology Data Exchange (ETDEWEB)

    Christianson, O; Winslow, J; Samei, E [Duke University Medical Center, Durham, NC (United States)

    2014-06-15

    Purpose: One of the principal challenges of clinical imaging is to achieve an ideal balance between image quality and radiation dose across multiple CT models. The number of scanners and protocols at large medical centers necessitates an automated quality assurance program to facilitate this objective. Therefore, the goal of this work was to implement an automated CT image quality and radiation dose monitoring program based on actual patient data and to use this program to assess consistency of protocols across CT scanner models. Methods: Patient CT scans are routed to a HIPPA compliant quality assurance server. CTDI, extracted using optical character recognition, and patient size, measured from the localizers, are used to calculate SSDE. A previously validated noise measurement algorithm determines the noise in uniform areas of the image across the scanned anatomy to generate a global noise level (GNL). Using this program, 2358 abdominopelvic scans acquired on three commercial CT scanners were analyzed. Median SSDE and GNL were compared across scanner models and trends in SSDE and GNL with patient size were used to determine the impact of differing automatic exposure control (AEC) algorithms. Results: There was a significant difference in both SSDE and GNL across scanner models (9–33% and 15–35% for SSDE and GNL, respectively). Adjusting all protocols to achieve the same image noise would reduce patient dose by 27–45% depending on scanner model. Additionally, differences in AEC methodologies across vendors resulted in disparate relationships of SSDE and GNL with patient size. Conclusion: The difference in noise across scanner models indicates that protocols are not optimally matched to achieve consistent image quality. Our results indicated substantial possibility for dose reduction while achieving more consistent image appearance. Finally, the difference in AEC methodologies suggests the need for size-specific CT protocols to minimize variability in image

  20. TH-C-18A-06: Combined CT Image Quality and Radiation Dose Monitoring Program Based On Patient Data to Assess Consistency of Clinical Imaging Across Scanner Models

    International Nuclear Information System (INIS)

    Christianson, O; Winslow, J; Samei, E

    2014-01-01

    Purpose: One of the principal challenges of clinical imaging is to achieve an ideal balance between image quality and radiation dose across multiple CT models. The number of scanners and protocols at large medical centers necessitates an automated quality assurance program to facilitate this objective. Therefore, the goal of this work was to implement an automated CT image quality and radiation dose monitoring program based on actual patient data and to use this program to assess consistency of protocols across CT scanner models. Methods: Patient CT scans are routed to a HIPPA compliant quality assurance server. CTDI, extracted using optical character recognition, and patient size, measured from the localizers, are used to calculate SSDE. A previously validated noise measurement algorithm determines the noise in uniform areas of the image across the scanned anatomy to generate a global noise level (GNL). Using this program, 2358 abdominopelvic scans acquired on three commercial CT scanners were analyzed. Median SSDE and GNL were compared across scanner models and trends in SSDE and GNL with patient size were used to determine the impact of differing automatic exposure control (AEC) algorithms. Results: There was a significant difference in both SSDE and GNL across scanner models (9–33% and 15–35% for SSDE and GNL, respectively). Adjusting all protocols to achieve the same image noise would reduce patient dose by 27–45% depending on scanner model. Additionally, differences in AEC methodologies across vendors resulted in disparate relationships of SSDE and GNL with patient size. Conclusion: The difference in noise across scanner models indicates that protocols are not optimally matched to achieve consistent image quality. Our results indicated substantial possibility for dose reduction while achieving more consistent image appearance. Finally, the difference in AEC methodologies suggests the need for size-specific CT protocols to minimize variability in image

  1. Implementation of virtual simulation with a wide-bore multislice helcalct scanner

    International Nuclear Information System (INIS)

    Greer, P.; Kenny, J.

    2004-01-01

    Full text: Multislice large-bore CT scanners specifically designed for radiotherapy have very recently become available. The issues relating to these type of scanners in radiotherapy and the implementation of virtual simulation are therefore of much current interest. A GE LightSpeed RT 4-slice helical CT scanner with a 80 cm bore size was installed in the radiation oncology department of the Newcastle Mater Hospital. This replaced our only simulator, a conventional unit. Specific issues relating to the imaging performance, and virtual simulation process with the large-bore multislice scanner were studied to ensure an accurate radiotherapy process. The detector array fully samples a 50 cm diameter scan circle. The reconstructed diameter can be increased to 65 cm with partial sampling of the extra volume. The GE Advantage Sim (ASim) virtual simulation software was commissioned, with transfer of CT images and DICOM RT plans to the Pinnacle radiotherapy planning system (RTPS) for dose calculation. Some specific issues investigated were: 1) The image quality performance for image reconstruction with the 65 cm area compared to 50 cm was measured with a line-pair phantom. 2) The accuracy of CT numbers with lateral position was assessed with a commercial electron density phantom. 3) Couch lateral movement and sag during acquisition were measured with the couch weighted with 86 kg. 4) The accuracy of the transfer of plans from ASim to Pinnacle was verified with known plan geometries. Image resolution throughout the entire CT image was found to be significantly lower when scan reconstruction was performed with 65 cm scan circle compared to 50 cm. The 0.3, 0.38 and 0.5 1p/mm bars were clearly distinguishable with the 50 cm reconstruction compared to only the 0.3 1p/mm bars in the 65 cm reconstruction. 2) CT numbers varied significantly outside the 50 cm reconstructed area. 3) Couch lateral movement during scanning was within 1 mm. Couch sag was 4 mm at the imaging plane

  2. Evaluation of a LED-based flatbed document scanner for radiochromic film dosimetry in transmission mode.

    Science.gov (United States)

    Lárraga-Gutiérrez, José Manuel; García-Garduño, Olivia Amanda; Treviño-Palacios, Carlos; Herrera-González, José Alfredo

    2018-03-01

    Flatbed scanners are the most frequently used reading instrument for radiochromic film dosimetry because its low cost, high spatial resolution, among other advantages. These scanners use a fluorescent lamp and a CCD array as light source and detector, respectively. Recently, manufacturers of flatbed scanners replaced the fluorescent lamp by light emission diodes (LED) as a light source. The goal of this work is to evaluate the performance of a commercial flatbed scanner with LED based source light for radiochromic film dosimetry. Film read out consistency, response uniformity, film-scanner sensitivity, long term stability and total dose uncertainty was evaluated. In overall, the performance of the LED flatbed scanner is comparable to that of a cold cathode fluorescent lamp (CCFL). There are important spectral differences between LED and CCFL lamps that results in a higher sensitivity of the LED scanner in the green channel. Total dose uncertainty, film response reproducibility and long-term stability of LED scanner are slightly better than those of the CCFL. However, the LED based scanner has a strong non-uniform response, up to 9%, that must be adequately corrected for radiotherapy dosimetry QA. The differences in light emission spectra between LED and CCFL lamps and its potential impact on film-scanner sensitivity suggest that the design of a dedicated flat-bed scanner with LEDs may improve sensitivity and dose uncertainty in radiochromic film dosimetry. Copyright © 2018 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  3. Active Labour Market Policy and Gender Mainstreaming in Germany: Gender-Specific Aspects of Participation and Destination in Selected Instruments of the Federal Employment Service. IAB Labour Market Research Topics.

    Science.gov (United States)

    Muller, Petra; Kurtz, Beate

    The equality of the opportunities available to males and females in Germany's labor market was examined. The study compared employment patterns among women and men and the extent to which selected discretionary benefits of Germany's Federal Employment Service benefit women and men. Selected results were as follows: (1) women are under-represented…

  4. Performance of an improved first generation optical CT scanner for 3D dosimetry

    International Nuclear Information System (INIS)

    Qian, Xin; Wuu, Cheng-Shie; Adamovics, John

    2013-01-01

    Performance analysis of a modified 3D dosimetry optical scanner based on the first generation optical CT scanner OCTOPUS is presented. The system consists of PRESAGE™ dosimeters, the modified 3D scanner, and a new developed in-house user control panel written in Labview program which provides more flexibility to optimize mechanical control and data acquisition technique. The total scanning time has been significantly reduced from initial 8 h to ∼2 h by using the modified scanner. The functional performance of the modified scanner has been evaluated in terms of the mechanical integrity uncertainty of the data acquisition process. Optical density distribution comparison between the modified scanner, OCTOPUS and the treatment plan system has been studied. It has been demonstrated that the agreement between the modified scanner and treatment plans is comparable with that between the OCTOPUS and treatment plans. (note)

  5. Portable CT scanners for use on live trees and standing columns

    International Nuclear Information System (INIS)

    Onoe, M.; Tsao, J.W.; Yamada, H.; Nakamura, H.; Kogure, J.; Kawamura, H.; Isono, E.; Maeda, Y.; Matsumoto, S.

    1985-01-01

    Computed tomography (CT) is a technique to reconstruct a crosssection of a test object from multiple projections obtained using e.g. x-rays. A large number of medical CT scanners and a few industrial CT scanners have been used. Most of these scanners are fixed installations. In contrast, we developed portable CT scanners for nondestructive testing of live trees and standing building columns in field environment. The resolution of these scanners is high enough to reveal details of annual rings of trees and timbers. The scanners have been useful in a wide range of applications. This paper presents two types of scanners with small and large apertures, a system for quick look of reconstruction and a few examples of applications

  6. Efficient system modeling for a small animal PET scanner with tapered DOI detectors

    International Nuclear Information System (INIS)

    Zhang, Mengxi; Zhou, Jian; Yang, Yongfeng; Qi, Jinyi; Rodríguez-Villafuerte, Mercedes

    2016-01-01

    A prototype small animal positron emission tomography (PET) scanner for mouse brain imaging has been developed at UC Davis. The new scanner uses tapered detector arrays with depth of interaction (DOI) measurement. In this paper, we present an efficient system model for the tapered PET scanner using matrix factorization and a virtual scanner geometry. The factored system matrix mainly consists of two components: a sinogram blurring matrix and a geometrical matrix. The geometric matrix is based on a virtual scanner geometry. The sinogram blurring matrix is estimated by matrix factorization. We investigate the performance of different virtual scanner geometries. Both simulation study and real data experiments are performed in the fully 3D mode to study the image quality under different system models. The results indicate that the proposed matrix factorization can maintain image quality while substantially reduce the image reconstruction time and system matrix storage cost. The proposed method can be also applied to other PET scanners with DOI measurement. (paper)

  7. Does the Use of Body Scanners Discriminate Overweight Flight Passengers? The Effect of Body Scanners on Body Image

    Directory of Open Access Journals (Sweden)

    Magdalena Laib

    2016-06-01

    Full Text Available Whereas the introduction of body scanners at airports has been accompanied by critical voices raising concerns that body scanners might have a negative impact on different minority groups, it has not been investigated thus far whether they might also have negative impacts on the average flight passenger and if the provision of adequate information might attenuate such negative impacts. Using a pre/post-design the current study examines the effect of a body scan in a controlled laboratory setting on the explicit and implicit body image of normal-weight and overweight people as assessed by questionnaires and an Implicit Association Test. Half of the sample received an information sheet concerning body scanners before they were scanned. While there was a negative impact of the body scan on the implicit body image of overweight participants, there was a positive impact on their explicit body image. The negative effect of the body scan was unaffected by receiving information. This study demonstrates that body scans do not only have negative effects on certain minority groups but potentially on a large proportion of the general public which suggests a critical reconsideration of the control procedures at airports, the training of the airport staff who is in charge of these procedures and the information flight passengers get about these procedures.

  8. Terrain Extraction by Integrating Terrestrial Laser Scanner Data and Spectral Information

    Science.gov (United States)

    Lau, C. L.; Halim, S.; Zulkepli, M.; Azwan, A. M.; Tang, W. L.; Chong, A. K.

    2015-10-01

    The extraction of true terrain points from unstructured laser point cloud data is an important process in order to produce an accurate digital terrain model (DTM). However, most of these spatial filtering methods just utilizing the geometrical data to discriminate the terrain points from nonterrain points. The point cloud filtering method also can be improved by using the spectral information available with some scanners. Therefore, the objective of this study is to investigate the effectiveness of using the three-channel (red, green and blue) of the colour image captured from built-in digital camera which is available in some Terrestrial Laser Scanner (TLS) for terrain extraction. In this study, the data acquisition was conducted at a mini replica landscape in Universiti Teknologi Malaysia (UTM), Skudai campus using Leica ScanStation C10. The spectral information of the coloured point clouds from selected sample classes are extracted for spectral analysis. The coloured point clouds which within the corresponding preset spectral threshold are identified as that specific feature point from the dataset. This process of terrain extraction is done through using developed Matlab coding. Result demonstrates that a higher spectral resolution passive image is required in order to improve the output. This is because low quality of the colour images captured by the sensor contributes to the low separability in spectral reflectance. In conclusion, this study shows that, spectral information is capable to be used as a parameter for terrain extraction.

  9. Automatic Generation of Indoor Navigable Space Using a Point Cloud and its Scanner Trajectory

    Science.gov (United States)

    Staats, B. R.; Diakité, A. A.; Voûte, R. L.; Zlatanova, S.

    2017-09-01

    Automatic generation of indoor navigable models is mostly based on 2D floor plans. However, in many cases the floor plans are out of date. Buildings are not always built according to their blue prints, interiors might change after a few years because of modified walls and doors, and furniture may be repositioned to the user's preferences. Therefore, new approaches for the quick recording of indoor environments should be investigated. This paper concentrates on laser scanning with a Mobile Laser Scanner (MLS) device. The MLS device stores a point cloud and its trajectory. If the MLS device is operated by a human, the trajectory contains information which can be used to distinguish different surfaces. In this paper a method is presented for the identification of walkable surfaces based on the analysis of the point cloud and the trajectory of the MLS scanner. This method consists of several steps. First, the point cloud is voxelized. Second, the trajectory is analysing and projecting to acquire seed voxels. Third, these seed voxels are generated into floor regions by the use of a region growing process. By identifying dynamic objects, doors and furniture, these floor regions can be modified so that each region represents a specific navigable space inside a building as a free navigable voxel space. By combining the point cloud and its corresponding trajectory, the walkable space can be identified for any type of building even if the interior is scanned during business hours.

  10. Investigation of Tree Spectral Reflectance Characteristics Using a Mobile Terrestrial Line Spectrometer and Laser Scanner

    Directory of Open Access Journals (Sweden)

    Eetu Puttonen

    2013-07-01

    Full Text Available In mobile terrestrial hyperspectral imaging, individual trees often present large variations in spectral reflectance that may impact the relevant applications, but the related studies have been seldom reported. To fill this gap, this study was dedicated to investigating the spectral reflectance characteristics of individual trees with a Sensei mobile mapping system, which comprises a Specim line spectrometer and an Ibeo Lux laser scanner. The addition of the latter unit facilitates recording the structural characteristics of the target trees synchronously, and this is beneficial for revealing the characteristics of the spatial distributions of tree spectral reflectance with variations at different levels. Then, the parts of trees with relatively low-level variations can be extracted. At the same time, since it is difficult to manipulate the whole spectrum, the traditional concept of vegetation indices (VI based on some particular spectral bands was taken into account here. Whether the assumed VIs capable of behaving consistently for the whole crown of each tree was also checked. The specific analyses were deployed based on four deciduous tree species and six kinds of VIs. The test showed that with the help of the laser scanner data, the parts of individual trees with relatively low-level variations can be located. Based on these parts, the relatively stable spectral reflectance characteristics for different tree species can be learnt.

  11. Single-Layer Laser Scanner for Detection and Localization of Unmanned Swarm Members

    Science.gov (United States)

    Krüger, T.; Nowak, S.; Matthaei, J.; Bestmann, U.

    2013-08-01

    In the presented work unmanned vehicles are used for an extra-terrestrial exploration mission. In this scenario a high factor of redundancy for all systems has to be considered. Defective sensors for instance cannot be repaired and any damage has to be compensated through an intelligent use of the remaining sensors and a robust data fusion. Therefore this work proposes the utilization of a singlelayer laser scanner, which is used for Simultaneous Localization And Mapping (SLAM) for the compensation of a defective relative positioning system. An Extended Kalman-Filter (EKF) with error states is used to perform the loosely coupled integration of the estimated states and the measured relative position in discrete updates. Subsequently the improvement of the navigation solution onboard an Unmanned Aerial Vehicles (UAV) can be estimated. The outcomes of a specifically developed simulation will be shown, delivering theoretic results for the proposed method. A flight test is done finally in order to prove the capability of the laser scanner to detect and locate an UAV.

  12. Performance Investigation of a Handheld 3d Scanner to Define Good Practices for Small Artefact 3d Modeling

    Science.gov (United States)

    Lachat, E.; Landes, T.; Grussenmeyer, P.

    2017-08-01

    Handheld 3D scanners can be used to complete large scale models with the acquisition of occluded areas or small artefacts. This may be of interest for digitization projects in the field of Cultural Heritage, where detailed areas may require a specific treatment. Such sensors present the advantage of being easily portable in the field, and easily usable even without particular knowledge. In this paper, the Freestyle3D handheld scanner launched on the market in 2015 by FARO is investigated. Different experiments are described, covering various topics such as the influence of range or color on the measurements, but also the precision achieved for geometrical primitive digitization. These laboratory experiments are completed by acquisitions performed on engraved and sculpted stone blocks. This practical case study is useful to investigate which acquisition protocol seems to be the more adapted and leads to precise results. The produced point clouds will be compared to photogrammetric surveys for the purpose of their accuracy assessment.

  13. Employer's Manual on Affirmative Action in Employment.

    Science.gov (United States)

    Kentucky State Commission on Human Rights, Frankfort.

    The express purpose of this manual is for its use by business and industry in Kentucky as an aid to eliminate discrimination. Affirmative action is defined here as a comprehensive effort by an employer designed to: employ women and minority persons where they are under-utilized; include minority persons and women in all facets of the company's…

  14. Employing Discourse: Universities and Graduate "Employability"

    Science.gov (United States)

    Boden, Rebecca; Nedeva, Maria

    2010-01-01

    What constitutes graduate employability is discursively framed. In this paper we argue that whilst universities in the UK have long had an involvement in producing useful and productive citizens, the ongoing neoliberalisation of higher education has engendered a discursive shift in definitions of employability. Traditionally, universities regarded…

  15. Flexible employment, precarious employees? Job-, employer- and institutional explanations for numerical flexibility, and its relation to precarious employment

    NARCIS (Netherlands)

    Olsthoorn, M.

    2015-01-01

    This dissertation presents a study of numerical flexibility and its relation to precarious employment in contemporary labour markets. Precarious employment is defined as the situation in which an employee has both insecure employment and insecure finances. More specifically, precarious employees are

  16. Becoming Self-Employed.

    Science.gov (United States)

    Lee, Grant; Cochran, Larry

    1997-01-01

    Explored how persons become self-employed. In critical incident interviews with five self-employed persons the critical events that assisted or hindered progress toward self-employment were listed in chronological order. In general, becoming self-employed involved establishing conditions of action that enhanced a sense of agency, thus enabling…

  17. Fixed term employment

    International Nuclear Information System (INIS)

    Durant, B.W.; Schonberner, M.J.

    1999-01-01

    A series of brief notes were included with this presentation which highlighted certain aspects of contract management. Several petroleum companies have realized the benefits of taking advantage of contract personnel to control fixed G and A, manage the impacts on their organization, contain costs, to manage termination costs, and to fill gaps in lean personnel rosters. An independent contractor was described as being someone who is self employed, often with a variety of work experiences. The tax benefits and flexibility of contractor personnel were also described. Some liability aspects of hiring an independent contractor were also reviewed. The courts have developed the following 4 tests to help determine whether an individual is an employee or an independent contractor: (1) the control test, (2) the business integration test, (3) specific result test, and (4) the economic reality test

  18. Authenticity in Employment Relations

    DEFF Research Database (Denmark)

    Tackney, Charles Thomas

    2018-01-01

    Authenticity is developed and deployed as a criterion variable for a theology of the workplace inquiry that combines theory and methodological development with data analysis. The goal is to show that social science method can offer an empirically valid, prophetic dimension to the study of employm......Authenticity is developed and deployed as a criterion variable for a theology of the workplace inquiry that combines theory and methodological development with data analysis. The goal is to show that social science method can offer an empirically valid, prophetic dimension to the study...... of employment and work parameters in light of religious teachings on the social question at national, organizational, or firm-specific levels. The function of a criterion variable is described, noting that the switch from a dependent variable approach introduces an open-system dynamism to social science...

  19. Myocardium scintigraphy and coronaries scanner: results and respective contribution of these two examinations; Scintigraphie myocardique et scanner coronaire: resultats et apport respectif des deux examens

    Energy Technology Data Exchange (ETDEWEB)

    Songy, B.; Balestrini, V.; Sablayrolles, J.L.; Vigoni, F.; Lussato, D. [Centre cardiologique du Nord (CCN), Saint-Denis, (France); Faccio, F. [fondation San Geronimo, Santa Fe, (Argentina)

    2009-05-15

    The objective were to evaluate the results and the respective contribution of the myocardium scintigraphy and the coro-scanner. It exists an excellent correlation between a normal scanner and a normal scintigraphy (97%). 30% of patients having non tight stenosis at scanner and 60% of these ones having tight stenosis have a scintigraphy ischemia; An abnormal scanner, whatever be the the degree of stenosis must be completed by a test of myocardium ischemia. The actual limitations of the coro-scanner (64 gills) are in relation with its spatial resolution (quantification) and temporal resolution (right coronary). The choice of the diagnosis examination to realize in first intention must depend on the age and prevalence of the coronary disease. (N.C.)

  20. Effect of mixing scanner types and reconstruction kernels on the characterization of lung parenchymal pathologies: emphysema, interstitial pulmonary fibrosis and normal non-smokers

    Science.gov (United States)

    Xu, Ye; van Beek, Edwin J.; McLennan, Geoffrey; Guo, Junfeng; Sonka, Milan; Hoffman, Eric

    2006-03-01

    In this study we utilize our texture characterization software (3-D AMFM) to characterize interstitial lung diseases (including emphysema) based on MDCT generated volumetric data using 3-dimensional texture features. We have sought to test whether the scanner and reconstruction filter (kernel) type affect the classification of lung diseases using the 3-D AMFM. We collected MDCT images in three subject groups: emphysema (n=9), interstitial pulmonary fibrosis (IPF) (n=10), and normal non-smokers (n=9). In each group, images were scanned either on a Siemens Sensation 16 or 64-slice scanner, (B50f or B30 recon. kernel) or a Philips 4-slice scanner (B recon. kernel). A total of 1516 volumes of interest (VOIs; 21x21 pixels in plane) were marked by two chest imaging experts using the Iowa Pulmonary Analysis Software Suite (PASS). We calculated 24 volumetric features. Bayesian methods were used for classification. Images from different scanners/kernels were combined in all possible combinations to test how robust the tissue classification was relative to the differences in image characteristics. We used 10-fold cross validation for testing the result. Sensitivity, specificity and accuracy were calculated. One-way Analysis of Variances (ANOVA) was used to compare the classification result between the various combinations of scanner and reconstruction kernel types. This study yielded a sensitivity of 94%, 91%, 97%, and 93% for emphysema, ground-glass, honeycombing, and normal non-smoker patterns respectively using a mixture of all three subject groups. The specificity for these characterizations was 97%, 99%, 99%, and 98%, respectively. The F test result of ANOVA shows there is no significant difference (p <0.05) between different combinations of data with respect to scanner and convolution kernel type. Since different MDCT and reconstruction kernel types did not show significant differences in regards to the classification result, this study suggests that the 3-D AMFM can

  1. Temperature dependence of APD-based PET scanners

    International Nuclear Information System (INIS)

    Keereman, Vincent; Van Holen, Roel; Vandenberghe, Stefaan; Vanhove, Christian

    2013-01-01

    Purpose: Solid state detectors such as avalanche photodiodes (APDs) are increasingly being used in PET detectors. One of the disadvantages of APDs is the strong decrease of their gain factor with increasing ambient temperature. The light yield of most scintillation crystals also decreases when ambient temperature is increased. Both effects lead to considerable temperature dependence of the performance of APD-based PET scanners. In this paper, the authors propose a model for this dependence and the performance of the LabPET8 APD-based small animal PET scanner is evaluated at different temperatures.Methods: The model proposes that the effect of increasing temperature on the energy histogram of an APD-based PET scanner is a compression of the histogram along the energy axis. The energy histogram of the LabPET system was acquired at 21 °C and 25 °C to verify the validity of this model. Using the proposed model, the effect of temperature on system sensitivity was simulated for different detector temperature coefficients and temperatures. Subsequently, the effect of short term and long term temperature changes on the peak sensitivity of the LabPET system was measured. The axial sensitivity profile was measured at 21 °C and 24 °C following the NEMA NU 4-2008 standard. System spatial resolution was also evaluated. Furthermore, scatter fraction, count losses and random coincidences were evaluated at different temperatures. Image quality was also investigated.Results: As predicted by the model, the photopeak energy at 25 °C is lower than at 21 °C with a shift of approximately 6% per °C. Simulations showed that this results in an approximately linear decrease of sensitivity when temperature is increased from 21 °C to 24 °C and energy thresholds are constant. Experimental evaluation of the peak sensitivity at different temperatures showed a strong linear correlation for short term (2.32 kcps/MBq/°C = 12%/°C, R = −0.95) and long term (1.92 kcps/MBq/°C = 10%/

  2. Quality control of some CT scanners in Khartoum state

    International Nuclear Information System (INIS)

    Yousif, Ali Mohammed Ali

    2013-06-01

    This study conduced with the aim to evaluate the performance of three CT scanner in Khartoum-Sudan through extensive quality control measurements. Image quality was assessed using a CATPHAN 412 CT image quality phantom. Image quality parameters evaluated were: CT image noise, uniformity, CT number linearity, Low Contrast Resolution, High Contrast Resolution, measurements were performed in accordance with guidelines set out by the Institute of physical science and engineering in medicine (IPEM 91). Image quality parameters tested were within the apoplectic limit specified in the relevant CT guidelines. Measured slice thickness ranged between 9.66-10.5 mm for large slice and 5.25-5.88 for medium slice. The correlation coefficient (R) between the measured and the reference CT number was better than 0.99 for all CT scanners. High resolution for large slice was 7 L P/ cm and 8 L P/ cm for small slice. Low contrast resolution with 1.0% nominal level ranged between 2-3 mm diameter of disc for large slice and 4-7 mm diameter disc for small slice. The measured noise ranged between 1.4-3.4 HU for large slice and 2.92-4.08 HU for small slice. Uniformity ranged between 3.08 to 2.075 HU for large slice and 3.22 to 1.4 HU for small slice thickness. The results indicate that routine maintenance, service and calibration, as well as the frequent quality control of CT scanners play a key rote in achieving the best performance of the system. Since computed tomography (CT) contributes the most to the collective dose compared to other radiological examinations, it is a necessity for quality control and quality assurance programs to be established in each radiology department.(Author)

  3. Experimental developments in dedicated scanners for positron emission tomography

    International Nuclear Information System (INIS)

    Damiani, Chiara

    2001-01-01

    The thesis describes a prototype of a new read out electronics developed for the YAPPET small animal PET tomograph at the Physics Laboratory of the University of Ferrara. The purpose of the new electronics was to make the YAPPET scanner easier to use and more suitable for duplication at other research institutes. The results of tests of the new electronics over a 3 year period are presented. The new electronics prototype attained the same performance as the present YAPPET electronics in energy, position, and time measurements. In addition, a significant improvement in count rate capability is now being studied. The second major component of this thesis is a description of the development of a new scanner prototype incorporating a PET detection system based on YAP:Ce scintillator matrix crystals and wave length shifting (WLS) fibers. Two ribbons of WLS fibers are mounted on the opposite sides of the scintillator matrix in order to read out the columns and the rows of the matrix and recognize the interaction point XY position. The thesis describes the investigation of the materials and methods to be used in this new design. The first tests with the new prototype detector are described in detail: the main result of these preliminary measurements is the evaluation of the light yield of the system which is a signal of about 10 photoelectrons on the detector for 511 keV photoelectric interactions. The new scanner design uses the YAPPET basic principles, but it should have improved performance with applicability to other fields such as scinti-mammography. Copies of this thesis can be obtained from the Department of Physics of the University of Pisa or the author

  4. Discourses on Employability: Constituting the Responsible Citizen

    Science.gov (United States)

    Fejes, Andreas

    2010-01-01

    In the last couple of decades, there has been a shift from speaking about employment to speaking about employability. The interest in this article is directed at how discourses on employability are mobilised in the wider discursive terrain of governance. How does governance operate, what subject is produced and, more specifically, who is…

  5. Comparative evaluation of ultrasound scanner accuracy in distance measurement

    Science.gov (United States)

    Branca, F. P.; Sciuto, S. A.; Scorza, A.

    2012-10-01

    The aim of the present study is to develop and compare two different automatic methods for accuracy evaluation in ultrasound phantom measurements on B-mode images: both of them give as a result the relative error e between measured distances, performed by 14 brand new ultrasound medical scanners, and nominal distances, among nylon wires embedded in a reference test object. The first method is based on a least squares estimation, while the second one applies the mean value of the same distance evaluated at different locations in ultrasound image (same distance method). Results for both of them are proposed and explained.

  6. Mapping of MAC Address with Moving WiFi Scanner

    Directory of Open Access Journals (Sweden)

    Arief Hidayat

    2017-10-01

    Full Text Available Recently, Wifi is one of the most useful technologies that can be used for detecting and counting MAC Address. This paper described using of WiFi scanner which carried out seven times circulated the bus. The method used WiFi and GPS are to counting MAC address as raw data from the pedestrian smartphone, bus passenger or WiFi devices near from the bus as long as the bus going around the route. There are seven processes to make map WiFi data.

  7. A new electronic read-out for the YAPPET scanner

    International Nuclear Information System (INIS)

    Damiani, C.; Ramusino, A.C.A. Cotta; Malaguti, R.; Guerra, A. Del; Domenico, G. Di; Zavattini, G.

    2002-01-01

    A small animal PET-SPECT scanner (YAPPET) prototype was built at the Physics Department of the Ferrara University and is presently being used at the Nuclear Medicine Department for radiopharmaceutical studies on rats. The first YAPPET prototype shows very good performances, but needs some improvements before it can be fully used for intensive radiopharmaceutical research. The main problem of the actual prototype is its heavy electronics, based on NIM and CAMAC standard modules. For this reason a new, compact read-out electronics was developed and tested. The results of a first series of tests made on the first prototype will be presented in the paper

  8. Computerized tomographic x-ray scanner system and gantry assembly

    International Nuclear Information System (INIS)

    Doyd, D.P.; Lanzara, G.

    1991-01-01

    This patent describes a scanner assembly. It comprises: a support head, a C-shaped gantry, means for supporting the gantry in the support head for rotating movement, an x-ray source mounted on one side of the gantry for independent movement with respect to a detector array along the gantry, the x-ray source projecting x-rays across the gantry, and a detector array mounted on the other side of a gantry for independent movement with respect to the x-ray source along the gantry, the detector array serving to receive the projected x-rays

  9. A new electronic read-out for the YAPPET scanner

    CERN Document Server

    Damiani, C; Malaguti, R; Guerra, A D; Domenico, G D; Zavattini, G

    2002-01-01

    A small animal PET-SPECT scanner (YAPPET) prototype was built at the Physics Department of the Ferrara University and is presently being used at the Nuclear Medicine Department for radiopharmaceutical studies on rats. The first YAPPET prototype shows very good performances, but needs some improvements before it can be fully used for intensive radiopharmaceutical research. The main problem of the actual prototype is its heavy electronics, based on NIM and CAMAC standard modules. For this reason a new, compact read-out electronics was developed and tested. The results of a first series of tests made on the first prototype will be presented in the paper.

  10. Applicability of optical scanner method for fine root dynamics

    Science.gov (United States)

    Kume, Tomonori; Ohashi, Mizue; Makita, Naoki; Khoon Kho, Lip; Katayama, Ayumi; Matsumoto, Kazuho; Ikeno, Hidetoshi

    2016-04-01

    Fine root dynamics is one of the important components in forest carbon cycling, as ~60 % of tree photosynthetic production can be allocated to root growth and metabolic activities. Various techniques have been developed for monitoring fine root biomass, production, mortality in order to understand carbon pools and fluxes resulting from fine roots dynamics. The minirhizotron method is now a widely used technique, in which a transparent tube is inserted into the soil and researchers count an increase and decrease of roots along the tube using images taken by a minirhizotron camera or minirhizotron video camera inside the tube. This method allows us to observe root behavior directly without destruction, but has several weaknesses; e.g., the difficulty of scaling up the results to stand level because of the small observation windows. Also, most of the image analysis are performed manually, which may yield insufficient quantitative and objective data. Recently, scanner method has been proposed, which can produce much bigger-size images (A4-size) with lower cost than those of the minirhizotron methods. However, laborious and time-consuming image analysis still limits the applicability of this method. In this study, therefore, we aimed to develop a new protocol for scanner image analysis to extract root behavior in soil. We evaluated applicability of this method in two ways; 1) the impact of different observers including root-study professionals, semi- and non-professionals on the detected results of root dynamics such as abundance, growth, and decomposition, and 2) the impact of window size on the results using a random sampling basis exercise. We applied our new protocol to analyze temporal changes of root behavior from sequential scanner images derived from a Bornean tropical forests. The results detected by the six observers showed considerable concordance in temporal changes in the abundance and the growth of fine roots but less in the decomposition. We also examined

  11. Coastal Zone Color Scanner data of rich coastal waters

    Science.gov (United States)

    Wrigley, R. C.; Klooster, S. A.

    1983-01-01

    Comparisons of chlorophyll concentrations and diffuse attenuation coefficients measured from ships off the central California coast were made with satellite derived estimates of the same parameters using data from the Coastal Zone Color Scanner. Very high chlorophyll concentrations were encountered in Monterey Bay. Although lower chlorophyll values acquired off Pt. Sur agreed satisfactorily with the satellite data, the high chlorophyll values departed markedly from agreement. Two possible causes for the disagreement are suggested. Comparison of diffuse attenuation coefficients from the same data sets showed closer agreement.

  12. Irradiation in helical scanner: doses estimation, parameters choice

    International Nuclear Information System (INIS)

    Cordoliani, Y.S.; Boyer, B.; Jouan, E.; Beauvais, H.

    2001-01-01

    The new generation of helical scanners improves the diagnosis abilities and the service done to the patients. The rational use allows to give the patients a ratio benefit/risk far better than the almost medical examinations. It is particularly true for over sixty years old aged people, that have a null genetic risk and a practically null carcinogen risk; However, for young adults and children, it is necessary to banish any useless irradiation and limit exposure to the strict necessary for the diagnosis. It is necessary to develop a radiation protection culture, possible by the radiation doses index display and doses benchmarks knowledge. (N.C.)

  13. Compact implementation of dynamic receive apodization in ultrasound scanners

    DEFF Research Database (Denmark)

    Tomov, Borislav Gueorguiev; Jensen, Jørgen Arendt

    2004-01-01

    The image quality in medical ultrasound scanners is determined by several factors, one of which is the ability of the receive beamformer to change the aperture weighting function with depth and beam angle. In digital beamformers, precise dynamic apodization can be achieved by representing the fun...... operate at 129.82 MHz and occupies 1.28 million gates. Simulated in Matlab, a 64-channel beamformer provides gray scale image with around 55 dB dynamic range. The beamformed data can also be used for flow estimation....

  14. Construction of a ct scanner using heavy ions or protons

    International Nuclear Information System (INIS)

    Elliott, D.O.

    1981-01-01

    A computed tomography x-ray scanner, in which a monochromatic xray beam is generated by irradiating an x-ray producing target with high energy monoenergetic ions. The ion beam is preferably produced by a cyclotron. The x-ray beam is preferably rotated through an object to be scanned by angularly displacing the ion beam and target about the center axis of the object. A conventional x-ray detector array, a signal and data processor and imaging means are provided to convert detected x-ray absorption measurements into a two-dimensional visual image of the scanned object cross-section

  15. Estimating Daily Inflation Using Scanner Data: A Progress Report

    OpenAIRE

    Kota Watanabe; Tsutomu Watanabe

    2014-01-01

    We construct a Törnqvist daily price index using Japanese point of sale (POS) scanner data spanning from 1988 to 2013. We find the following. First, the POS based inflation rate tends to be about 0.5 percentage points lower than the CPI inflation rate, although the difference between the two varies over time. Second, the difference between the two measures is greatest from 1992 to 1994, when, following the burst of bubble economy in 1991, the POS inflation rate drops rapidly and turns negati...

  16. Computed tomography scanner applied to soil compaction studies

    International Nuclear Information System (INIS)

    Vaz, C.M.P.

    1989-11-01

    The soil compaction problem was studied using a first generation computed tomography scanner (CT). This apparatus gets images of soil cross sections samples, with resolution of a few millimeters. We performed the following laboratory and field experiments: basic experiments of equipment calibrations and resolutions studies; measurements of compacted soil thin layers; measurements of soil compaction caused by agricultural tools; stress-strain modelling in confined soil sample, with several moisture degree; characterizations of soil bulk density profile with samples collected in a hole (trench), comparing with a cone penetrometer technique. (author)

  17. Design and Development of a Megavoltage CT Scanner for Radiation Therapy.

    Science.gov (United States)

    Chen, Ching-Tai

    A Varian 4 MeV isocentric therapy accelerator has been modified to perform also as a CT scanner. The goal is to provide low cost computed tomography capability for use in radiotherapy. The system will have three principal uses. These are (i) to provide 2- and 3-dimensional maps of electron density distribution for CT assisted therapy planning, (ii) to aid in patient set up by providing sectional views of the treatment volume and high contrast scout-mode verification images and (iii) to provide a means for periodically checking the patients anatomical conformation against what was used to generate the original therapy plan. The treatment machine was modified by mounting an array of detectors on a frame bolted to the counter weight end of the gantry in such a manner as to define a 'third generation' CT Scanner geometry. The data gathering is controlled by a Z-80 based microcomputer system which transfers the x-ray transmission data to a general purpose PDP 11/34 for processing. There a series of calibration processes and a logarithmic conversion are performed to get projection data. After reordering the projection data to an equivalent parallel beam sinogram format a convolution algorithm is employed to construct the image from the equivalent parallel projection data. Results of phantom studies have shown a spatial resolution of 2.6 mm and an electron density discrimination of less than 1% which are sufficiently good for accurate therapy planning. Results also show that the system is linear to within the precision of our measurement ((DBLTURN).75%) over a wide range of electron densities corresponding to those found in body tissues. Animal and human images are also presented to demonstrate that the system's imaging capability is sufficient to allow the necessary visualization of anatomy.

  18. The Employer Perspective on Sustainable Employability in the Construction Industry

    NARCIS (Netherlands)

    Tonnon, Susanne C; van der Veen, Rozan; Westerman, Marjan J; Robroek, Suzan J W; van der Ploeg, Hidde P; Van Der Beek, Allard J.; Proper, Karin I.

    OBJECTIVE: To determine the measures employers in the construction industry take to promote sustainable employability, the barriers and facilitators that influence implementation and employer needs. METHODS: Questionnaire among 499 employers and interviews with 17 employers. RESULTS: Employers

  19. Commissioning of a passive rod scanner at INB

    Energy Technology Data Exchange (ETDEWEB)

    Junqueira, Fabio da Silva; Oliveira, Carlos A.; Palheiros, Franklin, E-mail: carlossilva@inb.gov.br, E-mail: franklin@inb.gov.br [Industrias Nucleares do Brasil (INB), Resende, RJ (Brazil). Superintendencia de Engenharia do Combustivel; Fernandez, Pablo Jesus Piñer, E-mail: pineiro@tecnatom.es [Tecnatom, San Sebastian de los Reyes, Madrid (Spain)

    2015-07-01

    For the 21st reload for Angra 1, a shift from Standard to Advanced fuel design will be introduced, where the fuel assemblies under the new design will contain fuel rods with axial blanket, in line with ELETRONUCLEAR's requirement for a higher energy efficient reactor fuel. Additionally, fuel rods for Angra 2 and 3, using gadolinium type burnable poison, have to be submitted to inspections due to the demand for the same type of inspection, which cannot be certified at INB currently. In keeping with CNEN regulations, every fuel-assembly component must be inspected and certified by a qualified method. Nevertheless, INB lacks the means to perform the certification-required inspection aimed at determining the uranium enrichment and presence of gadolinium pellets inside the closed rods. Hence, the use is necessary of a scanner capable of inspecting differently enriched fuel rods and/or gadolinium pellets (axial blanket). This work aims to present the recent Passive Rod Scanner installed at INB with most advance technology in the area, making possible to completely fulfill Angra 1, 2 and 3 rods inspection at INB Resende site. (author)

  20. Scanners and drillers: Characterizing expert visual search through volumetric images

    Science.gov (United States)

    Drew, Trafton; Vo, Melissa Le-Hoa; Olwal, Alex; Jacobson, Francine; Seltzer, Steven E.; Wolfe, Jeremy M.

    2013-01-01

    Modern imaging methods like computed tomography (CT) generate 3-D volumes of image data. How do radiologists search through such images? Are certain strategies more efficient? Although there is a large literature devoted to understanding search in 2-D, relatively little is known about search in volumetric space. In recent years, with the ever-increasing popularity of volumetric medical imaging, this question has taken on increased importance as we try to understand, and ultimately reduce, errors in diagnostic radiology. In the current study, we asked 24 radiologists to search chest CTs for lung nodules that could indicate lung cancer. To search, radiologists scrolled up and down through a “stack” of 2-D chest CT “slices.” At each moment, we tracked eye movements in the 2-D image plane and coregistered eye position with the current slice. We used these data to create a 3-D representation of the eye movements through the image volume. Radiologists tended to follow one of two dominant search strategies: “drilling” and “scanning.” Drillers restrict eye movements to a small region of the lung while quickly scrolling through depth. Scanners move more slowly through depth and search an entire level of the lung before moving on to the next level in depth. Driller performance was superior to the scanners on a variety of metrics, including lung nodule detection rate, percentage of the lung covered, and the percentage of search errors where a nodule was never fixated. PMID:23922445

  1. Emittance scanner for intense low-energy ion beams

    International Nuclear Information System (INIS)

    Allison, P.W.; Sherman, J.D.; Holtkamp, D.B.

    1983-01-01

    An emittance scanner has been developed for use with low-energy H - ion beams to satisfy the following requirements: (1) angular resolution of +-1/2 mrad, (2) small errors from beam space charge, and (3) compact and simple design. The scanner consists of a 10-cm-long analyzer containing two slits and a pair of electric deflection plates driven by a +-500-V linear ramp generator. As the analyzer is mechanically driven across the beam, the front slit passes a thin ribbon of beam through the plates. The ion transit time is short compared with the ramp speed; therefore, the initial angle of the ions that pass through the rear slit is proportional to the instantaneous ramp voltage. The current through the rear slit then is proportional to the phase-space density d 2 i/dxdx'. The data are computer-analyzed to give, for example, rms emittance and phase-space density contours. Comparison of measured data with those calculated from a prepared (collimated) phase space is in good agreement

  2. A noble refractive optical scanner with linear response

    Science.gov (United States)

    Mega, Yair J.; Lai, Zhenhua; DiMarzio, Charles A.

    2013-03-01

    Many applications in various fields of science and engineering use steered optical beam systems. Currently, many methods utilize mirrors in order to steer the beam. However, this approach is an off-axis solution, which normally increases the total size of the system as well as its error and complexity. Other methods use a "Risely Prisms" based solution, which is on-axis solution, however it poses some difficulties from an engineering standpoint, and therefore isn't widely used. We present here a novel technique for steering a beam on its optical axis with a linear deflection response. We derived the formulation for the profile required of the refractive optical component necessary for preforming the beam steering. The functionality of the device was simulated analytically using Matlab, as well as using a ray-tracing software, Zemax, and showed agreement with the analytical model. An optical element was manufactured based on the proposed design and the device was tested. The results show agreement with our hypothesis. We also present some proposed geometries of the several other devices, all based on the same concept, which can be used for higher performance applications such as two-dimensional scanner, video rate scanner etc.

  3. A Moving 3D Laser Scanner for Automated Underbridge Inspection

    Directory of Open Access Journals (Sweden)

    Marco Tarabini

    2017-12-01

    Full Text Available Recent researches have proven that the underbridge geometry can be reconstructed by mounting a 3D laser scanner on a motorized cart travelling on a walkway located under the bridge. The walkway is moved by a truck and the accuracy of the bridge model depends on the accuracy of the trajectory of the scanning head with respect to a fixed reference system. In this paper, we describe a vision-based measurement system that can be used to identify the relative motion of the cart that moves the 3D laser scanner with respect to the walkway. The orientation of the walkway with respect to the bridge is determined using inclinometers and a camera that detect the position of a laser spot, while the position of the truck with respect to the bridge is measured using a conventional odometer. The accuracy of the proposed system was initially evaluated by numerical simulations and successively verified by experiments in laboratory conditions. The complete system has then been tested by comparing the geometry of buildings reconstructed using the proposed system with the geometry obtained with a static scan. Results showed that the error is less than 6 mm; given the satisfying quality of the point clouds obtained, it is also possible to detect small defects on the surface.

  4. Quality control of the Korle Bu rectilinear scanner

    International Nuclear Information System (INIS)

    Feli, S.K.; Tetteh, G.K.

    1993-01-01

    The attainment of high standards of efficiency and reliability in the practice of nuclear medicine requires an appropriate quality assurance programme. Routine monitoring of nuclear medicine instruments, using test procedures that provide check of the quality and reproducibility of instrument performance, aims at giving the user the confidence in the data collected and in updating the performance of the instrument. Quality control testing schedule for rectilinear scanners include weekly density calibration and monthly performance contrast enhancement and collimator evaluation. Discussion in this work is restricted to collimator evaluation which is required to be performed at the initial stages of installation as acceptance reference. However unlike the density, calibration and contrast enhancement, there is no documented work on this for the M800 Scintikart Scanner - a Hungarian Gamma Muvek system belonging to the Korle Bu Hospital, Accra. Tests of linearity of energy, relative sensitivity and resolution including energy and spatial resolutions were conducted in respect of collimator evaluation. In the linearity test it was ascertained that a nonlinear relationship exists between the centre of the window setting and the energy of the photopeak. The spectrometer was calibrated independently for each radionuclide and the position of Tc-99m obtained at 0.45 MeV on the MeV scale. In addition, the F272a13 Collimator offered a better resolution than the routinely used F272a136 collimator which has the highest sensitivity. (author). 10 refs.; 1 tab.; 10 figs

  5. X-ray backscatter imaging with a spiral scanner

    International Nuclear Information System (INIS)

    Bossi, R.H.; Cline, J.L.; Friddell, K.D.

    1989-01-01

    X-ray backscatter imaging allows radiographic inspections to be performed with access to only one side of the object. A collimated beam of radiation striking an object will scatter x-rays by Compton scatter and x-ray fluorescence. A detector located on the source side of the part will measure the backscatter signal. By plotting signal strength as gray scale intensity vs. beam position on the object, an image of the object can be constructed. A novel approach to the motion of the collimated incident beam is a spiral scanner. The spiral scanner approach, described in this paper, can image an area of an object without the synchronized motion of the object or detector, required by other backscatter imaging techniques. X-ray backscatter is particularly useful for flaw detection in light element materials such as composites. The ease of operation and the ability to operate non-contact from one side of an object make x-ray backscatter imaging of increasing interest to industrial inspection problems

  6. Computed tomographic mammography using a conventional body scanner.

    Science.gov (United States)

    Chang, C H; Nesbit, D E; Fisher, D R; Fritz, S L; Dwyer, S J; Templeton, A W; Lin, F; Jewell, W R

    1982-03-01

    The technique for computed tomographic (CT) examination of the breasts using a conventional body scanner is described, and experience with 67 patients is reported. In the diagnosis of both malignant and benign breast lesions, the results with a body scanner were equal to those of a dedicated CT/M mammographic unit. Although the CT study of the breast cannot replace conventional mammography in screening or in routine diagnostic workup, the unique capability of demonstrating both anatomic changes and increased iodide concentration in a cancer provides many advantages over conventional mammography. CT mammography appears to have the capability to detect breast cancers that are occult to other methods. Indications for a CT study of the breasts are: (1) clinically suspected breast cancer, especially with a mammographically occult lesion; (2) questionable mammographic findings, including microcalcifications, tumor shape, architectural distortion, and uncertain lesion location; and (3) evaluation of postbiopsy or postlumpectomy breast cancers when a primary irradiation therapy is contemplated. Breast CT also appears to be a valuable diagnostic tool in searching for a second primary breast cancer, follow-up study of postirradiation of breast cancer, followup study for postmastectomy patients, and screening procedure for genetically high-risk patients, especially those with dense breasts.

  7. Development of contact scanner for Wolsung NPP alarm and annunciation system

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Eung Se [Korea Electric Power Corp. (KEPCO), Taejon (Korea, Republic of). Research Center

    1995-12-31

    Contact scanner system in Wolsung NPP(model ESE-1565) is early `70 equipment so most of components are obsolete. To make 100% compatible PCBs for this system is main object of the study. Most of components used in the system are now not available in the electric market, furthermore original system maker no longer supplies spare parts. System supplier(AECL) quoted lots of money than general PCBs prices in case of spare PCBs are re-marked by canada maker. Contents and scope of the study are specifications research and system analysis, improvements of repairability and reliability, circuit design and simulations using computer aided tools(CAE), make arbitrary mechanical contacts signal generator for test system. Now the long-run test of home made PCBs are conducting at Wolsung NPP. (author). 20 refs., 42 figs.

  8. Monte Carlo simulation of efficient data acquisition for an entire-body PET scanner

    Energy Technology Data Exchange (ETDEWEB)

    Isnaini, Ismet; Obi, Takashi [Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503 (Japan); Yoshida, Eiji, E-mail: rush@nirs.go.jp [National Institute of Radiological Sciences, 4-9-1 Inage-ku, Chiba 263-8555 (Japan); Yamaya, Taiga [National Institute of Radiological Sciences, 4-9-1 Inage-ku, Chiba 263-8555 (Japan)

    2014-07-01

    Conventional PET scanners can image the whole body using many bed positions. On the other hand, an entire-body PET scanner with an extended axial FOV, which can trace whole-body uptake images at the same time and improve sensitivity dynamically, has been desired. The entire-body PET scanner would have to process a large amount of data effectively. As a result, the entire-body PET scanner has high dead time at a multiplex detector grouping process. Also, the entire-body PET scanner has many oblique line-of-responses. In this work, we study an efficient data acquisition for the entire-body PET scanner using the Monte Carlo simulation. The simulated entire-body PET scanner based on depth-of-interaction detectors has a 2016-mm axial field-of-view (FOV) and an 80-cm ring diameter. Since the entire-body PET scanner has higher single data loss than a conventional PET scanner at grouping circuits, the NECR of the entire-body PET scanner decreases. But, single data loss is mitigated by separating the axially arranged detector into multiple parts. Our choice of 3 groups of axially-arranged detectors has shown to increase the peak NECR by 41%. An appropriate choice of maximum ring difference (MRD) will also maintain the same high performance of sensitivity and high peak NECR while at the same time reduces the data size. The extremely-oblique line of response for large axial FOV does not contribute much to the performance of the scanner. The total sensitivity with full MRD increased only 15% than that with about half MRD. The peak NECR was saturated at about half MRD. The entire-body PET scanner promises to provide a large axial FOV and to have sufficient performance values without using the full data.

  9. Employment and Regional Inequality in Romania

    Directory of Open Access Journals (Sweden)

    Laura Patache

    2013-08-01

    Full Text Available It is no doubt that thinking about inequality plays a part in the judgments and actions of politicians, sociologists, economists and ordinary people, too. This paper examines which factors substantially influenced regional employment. Labour market, employment and unemployment have been the subject of various researches and the labour market object has been subject of dispute. Employment and unemployment are both decomposed and analyzed through separate components (such as: full employment, effective employment, atypical employment, precarious employment, regional/local employment etc., respectively, total unemployment, partial or hidden unemployment, technical and structural one and so on. The specific literature about the regional inequalities considered the income per capita as the most relevant indicator measured by Gini coefficient. Gini index measures the extent to which the distribution of income or consumption expenditure among individuals or households within an economy deviates from a perfectly equal distribution. At regional level we studied several indicators that generate regional disparities, and influence employment quality such us: employment rate, tertiary and medium employment, unemployment rate, occupied population in informal sector, employment in primary sector, rural employment, female employment. We developed a scoring based on the deviation from the average of a group of key indicators and devised a map of employment quality resulting from multi-criteria analysis.

  10. Perspectives of employability skills

    OpenAIRE

    ANNE LOUISE NEWTON

    2017-01-01

    The study investigated the different perspectives held by young people, employers and policy makers around Employability Skills and it examined how young people learnt these skills. This study draws young peoples’ perspectives into the research around Employability Skills and highlights the way in which social and cultural capital mediate their development. The research points to a model to re-vision employability skills which recognises the many ways in which they are learnt, over time a...

  11. Youth employment in Egypt

    OpenAIRE

    Eekelen, Willem van; De Luca, Loretta; Ismail, Magwa

    2001-01-01

    Examines economic and social factors affecting youth employment in Egypt and describes three national programmes for the promotion of youth employment based on human resources development, direct job creation and support in self-employment and enterprise creation. Describes one public-private project in each case.

  12. Employment in Agribusiness.

    Science.gov (United States)

    Hilgenberg, Gene; Huston, Jane

    This curriculum guide is intended to assist persons teaching a course in employment in agribusiness. Addressed in the individual units of instruction are the following topics: employment information (training plans/agreements and wages, taxes, and fringe benefits); human relations (employer/employee/customer relations and communication skills);…

  13. Social innovation in employment

    NARCIS (Netherlands)

    Oeij, P.R.A.; Torre, W. van der; Santoclides, M.E

    2017-01-01

    This policy brief on Social Innovation of Employment informs on an inventory of challenges and policy recommendations based on the Case Study Report of Employment and on the Second Policy Foresight Workshop of Employment. A ‘paradigm shift’ is needed in the mind-set of policymakers. ‘Traditional’

  14. Fast neutron radiography scanner for the detection of contraband in air cargo containers

    International Nuclear Information System (INIS)

    Eberhardt, J.E.; Rainey, S.; Stevens, R.J.; Sowerby, B.D.; Tickner, J.R.

    2005-01-01

    There is a growing need to rapidly scan bulk air cargo for contraband such as illicit drugs and explosives. The Commonwealth Science and Industrial Research Organisation (CSIRO) have been working with Australian Customs Service to develop a scanner capable of directly scanning airfreight containers in 1-2 minutes without unpacking. The scanner combines fast neutron and gamma-ray radiography to provide high-resolution images that include information on material composition. A full-scale prototype scanner has been successfully tested in the laboratory and a commercial-scale scanner is due to be installed at Brisbane airport in 2005

  15. Fast neutron radiography scanner for the detection of contraband in air cargo containers

    Energy Technology Data Exchange (ETDEWEB)

    Eberhardt, J.E. [CSIRO Minerals, Private Mail Bag 5, Menai, NSW 2234 (Australia); Rainey, S. [CSIRO Minerals, Private Mail Bag 5, Menai, NSW 2234 (Australia); Stevens, R.J. [CSIRO Minerals, Private Mail Bag 5, Menai, NSW 2234 (Australia); Sowerby, B.D. [CSIRO Minerals, Private Mail Bag 5, Menai, NSW 2234 (Australia)]. E-mail: brian.sowerby@csiro.au; Tickner, J.R. [CSIRO Minerals, Private Mail Bag 5, Menai, NSW 2234 (Australia)

    2005-08-01

    There is a growing need to rapidly scan bulk air cargo for contraband such as illicit drugs and explosives. The Commonwealth Science and Industrial Research Organisation (CSIRO) have been working with Australian Customs Service to develop a scanner capable of directly scanning airfreight containers in 1-2 minutes without unpacking. The scanner combines fast neutron and gamma-ray radiography to provide high-resolution images that include information on material composition. A full-scale prototype scanner has been successfully tested in the laboratory and a commercial-scale scanner is due to be installed at Brisbane airport in 2005.

  16. Ultra-High-Resolution Computed Tomography of the Lung: Image Quality of a Prototype Scanner

    OpenAIRE

    Kakinuma, Ryutaro; Moriyama, Noriyuki; Muramatsu, Yukio; Gomi, Shiho; Suzuki, Masahiro; Nagasawa, Hirobumi; Kusumoto, Masahiko; Aso, Tomohiko; Muramatsu, Yoshihisa; Tsuchida, Takaaki; Tsuta, Koji; Maeshima, Akiko Miyagi; Tochigi, Naobumi; Watanabe, Shun-ichi; Sugihara, Naoki

    2015-01-01

    Purpose: The image noise and image quality of a prototype ultra-high-resolution computed tomography (U-HRCT) scanner was evaluated and compared with those of conventional high-resolution CT (C-HRCT) scanners. Materials and Methods: This study was approved by the institutional review board. A U-HRCT scanner prototype with 0.25 mm × 4 rows and operating at 120 mAs was used. The C-HRCT images were obtained using a 0.5 mm × 16 or 0.5 mm × 64 detector-row CT scanner operating at 150 mAs. Images fr...

  17. Imaging system models for small-bore DOI-PET scanners

    International Nuclear Information System (INIS)

    Takahashi, Hisashi; Kobayashi, Tetsuya; Yamaya, Taiga; Murayama, Hideo; Kitamura, Keishi; Hasegawa, Tomoyuki; Suga, Mikio

    2006-01-01

    Depth-of-interaction (DOI) information, which improves resolution uniformity in the field of view (FOV), is expected to lead to high-sensitivity PET scanners with small-bore detector rings. We are developing small-bore PET scanners with DOI detectors arranged in hexagonal or overlapped tetragonal patterns for small animal imaging or mammography. It is necessary to optimize the imaging system model because these scanners exhibit irregular detector sampling. In this work, we compared two imaging system models: (a) a parallel sub-LOR model in which the detector response functions (DRFs) are assumed to be uniform along the line of responses (LORs) and (b) a sub-crystal model in which each crystal is divided into a set of smaller volumes. These two models were applied to the overlapped tetragonal scanner (FOV 38.1 mm in diameter) and the hexagonal scanner (FOV 85.2 mm in diameter) simulated by GATE. We showed that the resolution non-uniformity of system model (b) was improved by 40% compared with that of system model (a) in the overlapped tetragonal scanner and that the resolution non-uniformity of system model (a) was improved by 18% compared with that of system model (b) in the hexagonal scanner. These results indicate that system model (b) should be applied to the overlapped tetragonal scanner and system model (a) should be applied to the hexagonal scanner. (author)

  18. Employers Roundtable: Employer Supported Child Care.

    Science.gov (United States)

    Delaware Valley Child Care Council, Philadelphia, PA.

    This booklet outlines a number of options available to employers to enable them to better cope with child care issues that they and their employees face. Major options include: (1) flexible work policies, such as flexible scheduling, alternate work places, shorter work weeks, and the consolidating of sick leave, holidays, and vacation time into…

  19. Multi-spectral optical scanners for commercial earth observation missions

    Science.gov (United States)

    Schröter, Karin; Engel, Wolfgang; Berndt, Klaus

    2017-11-01

    In recent years, a number of commercial Earth observation missions have been initiated with the aim to gather data in the visible and near-infrared wavelength range. Some of these missions aim at medium resolution (5 to 10 m) multi-spectral imaging with the special background of daily revisiting. Typical applications aim at monitoring of farming area for growth control and harvest prediction, irrigation control, or disaster monitoring such as hail damage in farming, or flood survey. In order to arrive at profitable business plans for such missions, it is mandatory to establish the space segment, i.e. the spacecraft with their opto -electronic payloads, at minimum cost while guaranteeing maximum reliability for mission success. As multiple spacecraft are required for daily revisiting, the solutions are typically based on micro-satellites. This paper presents designs for multi-spectral opto-electric scanners for this type of missions. These designs are drive n by minimum mass and power budgets of microsatellites, and the need for minimum cost. As a consequence, it is mandatory to arrive at thermally robust, compact telescope designs. The paper gives a comparison between refractive, catadioptric, and TMA optics. For mirror designs, aluminium and Zerodur mirror technologies are briefly discussed. State-of-the art focal plane designs are presented. The paper also addresses the choice of detector technologies such as CCDs and CMOS Active Pixel Sensors. The electronics of the multi-spectral scanners represent the main design driver regarding power consumption, reliability, and (most often) cost. It can be subdivided into the detector drive electronics, analog and digital data processing chains, the data mass memory unit, formatting and down - linking units, payload control electronics, and local power supply. The paper gives overviews and trade-offs between data compression strategies and electronics solutions, mass memory unit designs, and data formatting approaches

  20. Employer attractiveness from a generational perspective: Implications for employer branding

    Directory of Open Access Journals (Sweden)

    Germano Glufke Reis

    2016-03-01

    Full Text Available ABSTRACT This study aimed to identify the employer attractiveness factors prioritized by different generations: Baby Boomers, Generation X, and Generation Y. The survey was conducted with a sample of 937 professionals, working in various areas and companies, most of them were managers and had a high education level. The Employer Attractiveness Scale proposed by Berthon et al. (2005 was adopted and the results indicate that, when choosing a company, the generations under study have specific features regarding the attractiveness attributes they prioritize. It was also observed that Generation Y discriminates and ranks such attributes more clearly than the others. Possible implications for employer branding and research limitations are discussed at the end of the article.

  1. Re-evaluation of structural shielding designs of X-ray and CO-60 gamma-ray scanners at the Port of Tema, Ghana

    International Nuclear Information System (INIS)

    Ofori, K.

    2011-07-01

    This research work was conducted to re-evaluate the shielding designs of the 6 MeV x-ray and the 1.253 MeV Co-60 gamma ray scanners used for cargo-containerized scanning at the Port of Tema. These scanners utilize ionizing radiation, therefore adequate shielding must be provided to reduce the radiation exposure of persons in and around the facilities to acceptable levels. The purpose of radiation shielding is to protect workers and the general public from the harmful effects of ionizing radiation. Investigations on the facilities indicated that after commissioning, no work had been carried out to re-evaluate the shielding designs. However, workloads have increased over time neccessitating review of the installed shielding. There has been introduction of scanner units with higher radiation energy (as in the case of the x-ray scanner) posibily increasing dose rates at various location requiring review of the shielding. New structures have been dotted around the facilities without particular attention to their distances and locations with respect to the radiation source. Measurements of distances from the source axes to the points of concern for primary and leakage barrier shielding; source to container and container to the points of concern for scattered radiation shielding were taken. The primary and secondary thicknesses required for both scanners were determined based on current operational parameters and compared with the thickness constituted during the construction of the facilities. Calculated and measured dose rate beyond the shielding barriers were used to established the adequacy or otherwise of the shielding employed by the shielding designers. Values obtained fell below the 20 µSv/hr specified by NCRP 151 (2005) which showed that the primary and secondary shields of both facilities were adequate requiring no additional shielding. (author)

  2. The accuracy of the CAD system using intraoral and extraoral scanners for designing of fixed dental prostheses.

    Science.gov (United States)

    Shimizu, Sakura; Shinya, Akikazu; Kuroda, Soichi; Gomi, Harunori

    2017-07-26

    The accuracy of prostheses affects clinical success and is, in turn, affected by the accuracy of the scanner and CAD programs. Thus, their accuracy is important. The first aim of this study was to evaluate the accuracy of an intraoral scanner with active triangulation (Cerec Omnicam), an intraoral scanner with a confocal laser (3Shape Trios), and an extraoral scanner with active triangulation (D810). The second aim of this study was to compare the accuracy of the digital crowns designed with two different scanner/CAD combinations. The accuracy of the intraoral scanners and extraoral scanner was clinically acceptable. Marginal and internal fit of the digital crowns fabricated using the intraoral scanner and CAD programs were inferior to those fabricated using the extraoral scanner and CAD programs.

  3. Automated size-specific CT dose monitoring program: Assessing variability in CT dose

    International Nuclear Information System (INIS)

    Christianson, Olav; Li Xiang; Frush, Donald; Samei, Ehsan

    2012-01-01

    adjusted by patient size. Additionally, considerable differences were noted in ED adj distributions between scanners, with scanners employing iterative reconstruction exhibiting significantly lower ED adj (range: 9%–64%). Finally, a significant difference (up to 59%) in ED adj distributions was observed between institutions, indicating the potential for dose reduction. Conclusions: The authors developed a robust automated size-specific radiation dose monitoring program for CT. Using this program, significant differences in ED adj were observed between scanner models and across institutions. This new dose monitoring program offers a unique tool for improving quality assurance and standardization both within and across institutions.

  4. Automated size-specific CT dose monitoring program: Assessing variability in CT dose

    Energy Technology Data Exchange (ETDEWEB)

    Christianson, Olav; Li Xiang; Frush, Donald; Samei, Ehsan [Clinical Imaging Physics Group, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 and Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Clinical Imaging Physics Group, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States) and Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Clinical Imaging Physics Group, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Department of Physics, Duke University, Durham, North Carolina 27710 (United States); and Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708 (United States)

    2012-11-15

    estimates that were not adjusted by patient size. Additionally, considerable differences were noted in ED{sub adj} distributions between scanners, with scanners employing iterative reconstruction exhibiting significantly lower ED{sub adj} (range: 9%-64%). Finally, a significant difference (up to 59%) in ED{sub adj} distributions was observed between institutions, indicating the potential for dose reduction. Conclusions: The authors developed a robust automated size-specific radiation dose monitoring program for CT. Using this program, significant differences in ED{sub adj} were observed between scanner models and across institutions. This new dose monitoring program offers a unique tool for improving quality assurance and standardization both within and across institutions.

  5. Accuracy of single-abutment digital cast obtained using intraoral and cast scanners.

    Science.gov (United States)

    Lee, Jae-Jun; Jeong, Ii-Do; Park, Jin-Young; Jeon, Jin-Hun; Kim, Ji-Hwan; Kim, Woong-Chul

    2017-02-01

    Scanners are frequently used in the fabrication of dental prostheses. However, the accuracy of these scanners is variable, and little information is available. The purpose of this in vitro study was to compare the accuracy of cast scanners with that of intraoral scanners by using different image impression techniques. A poly(methyl methacrylate) master model was fabricated to replicate a maxillary first molar single-abutment tooth model. The master model was scanned with an accurate engineering scanner to obtain a true value (n=1) and with 2 intraoral scanners (CEREC Bluecam and CEREC Omnicam; n=6 each). The cast scanner scanned the master model and duplicated the dental stone cast from the master model (n=6). The trueness and precision of the data were measured using a 3-dimensional analysis program. The Kruskal-Wallis test was used to compare the different sets of scanning data, followed by a post hoc Mann-Whitney U test with a significance level modified by Bonferroni correction (α/6=.0083). The type 1 error level (α) was set at .05. The trueness value (root mean square: mean ±standard deviation) was 17.5 ±1.8 μm for the Bluecam, 13.8 ±1.4 μm for the Omnicam, 17.4 ±1.7 μm for cast scanner 1, and 12.3 ±0.1 μm for cast scanner 2. The differences between the Bluecam and the cast scanner 1 and between the Omnicam and the cast scanner 2 were not statistically significant (P>.0083), but a statistically significant difference was found between all the other pairs (POmnicam, 9.2 ±1.2 μm for cast scanner 1, and 6.9 ±2.6 μm for cast scanner 2. The differences between Bluecam and Omnicam and between Omnicam and cast scanner 1 were not statistically significant (P>.0083), but there was a statistically significant difference between all the other pairs (POmnicam in video image impression had better trueness than a cast scanner but with a similar level of precision. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by

  6. Ultra-High-Resolution Computed Tomography of the Lung: Image Quality of a Prototype Scanner

    Science.gov (United States)

    Kakinuma, Ryutaro; Moriyama, Noriyuki; Muramatsu, Yukio; Gomi, Shiho; Suzuki, Masahiro; Nagasawa, Hirobumi; Kusumoto, Masahiko; Aso, Tomohiko; Muramatsu, Yoshihisa; Tsuchida, Takaaki; Tsuta, Koji; Maeshima, Akiko Miyagi; Tochigi, Naobumi; Watanabe, Shun-ichi; Sugihara, Naoki; Tsukagoshi, Shinsuke; Saito, Yasuo; Kazama, Masahiro; Ashizawa, Kazuto; Awai, Kazuo; Honda, Osamu; Ishikawa, Hiroyuki; Koizumi, Naoya; Komoto, Daisuke; Moriya, Hiroshi; Oda, Seitaro; Oshiro, Yasuji; Yanagawa, Masahiro; Tomiyama, Noriyuki; Asamura, Hisao

    2015-01-01

    Purpose The image noise and image quality of a prototype ultra-high-resolution computed tomography (U-HRCT) scanner was evaluated and compared with those of conventional high-resolution CT (C-HRCT) scanners. Materials and Methods This study was approved by the institutional review board. A U-HRCT scanner prototype with 0.25 mm x 4 rows and operating at 120 mAs was used. The C-HRCT images were obtained using a 0.5 mm x 16 or 0.5 mm x 64 detector-row CT scanner operating at 150 mAs. Images from both scanners were reconstructed at 0.1-mm intervals; the slice thickness was 0.25 mm for the U-HRCT scanner and 0.5 mm for the C-HRCT scanners. For both scanners, the display field of view was 80 mm. The image noise of each scanner was evaluated using a phantom. U-HRCT and C-HRCT images of 53 images selected from 37 lung nodules were then observed and graded using a 5-point score by 10 board-certified thoracic radiologists. The images were presented to the observers randomly and in a blinded manner. Results The image noise for U-HRCT (100.87 ± 0.51 Hounsfield units [HU]) was greater than that for C-HRCT (40.41 ± 0.52 HU; P < .0001). The image quality of U-HRCT was graded as superior to that of C-HRCT (P < .0001) for all of the following parameters that were examined: margins of subsolid and solid nodules, edges of solid components and pulmonary vessels in subsolid nodules, air bronchograms, pleural indentations, margins of pulmonary vessels, edges of bronchi, and interlobar fissures. Conclusion Despite a larger image noise, the prototype U-HRCT scanner had a significantly better image quality than the C-HRCT scanners. PMID:26352144

  7. Ultra-High-Resolution Computed Tomography of the Lung: Image Quality of a Prototype Scanner.

    Directory of Open Access Journals (Sweden)

    Ryutaro Kakinuma

    Full Text Available The image noise and image quality of a prototype ultra-high-resolution computed tomography (U-HRCT scanner was evaluated and compared with those of conventional high-resolution CT (C-HRCT scanners.This study was approved by the institutional review board. A U-HRCT scanner prototype with 0.25 mm x 4 rows and operating at 120 mAs was used. The C-HRCT images were obtained using a 0.5 mm x 16 or 0.5 mm x 64 detector-row CT scanner operating at 150 mAs. Images from both scanners were reconstructed at 0.1-mm intervals; the slice thickness was 0.25 mm for the U-HRCT scanner and 0.5 mm for the C-HRCT scanners. For both scanners, the display field of view was 80 mm. The image noise of each scanner was evaluated using a phantom. U-HRCT and C-HRCT images of 53 images selected from 37 lung nodules were then observed and graded using a 5-point score by 10 board-certified thoracic radiologists. The images were presented to the observers randomly and in a blinded manner.The image noise for U-HRCT (100.87 ± 0.51 Hounsfield units [HU] was greater than that for C-HRCT (40.41 ± 0.52 HU; P < .0001. The image quality of U-HRCT was graded as superior to that of C-HRCT (P < .0001 for all of the following parameters that were examined: margins of subsolid and solid nodules, edges of solid components and pulmonary vessels in subsolid nodules, air bronchograms, pleural indentations, margins of pulmonary vessels, edges of bronchi, and interlobar fissures.Despite a larger image noise, the prototype U-HRCT scanner had a significantly better image quality than the C-HRCT scanners.

  8. Jefferson Lab IR demo FEL photocathode quantum efficiency scanner

    CERN Document Server

    Gubeli, J; Grippo, A; Jordan, K; Shinn, M; Siggins, T

    2001-01-01

    Jefferson Laboratory's Free Electron Laser (FEL) incorporates a cesiated gallium arsenide (GaAs) DC photocathode gun as its electron source. By using a set of scanning mirrors, the surface of the GaAs wafer is illuminated with a 543.5nm helium-neon laser. Measuring the current flow across the biased photocathode generates a quantum efficiency (QE) map of the 1-in. diameter wafer surface. The resulting QE map provides a very detailed picture of the efficiency of the wafer surface. By generating a QE map in a matter of minutes, the photocathode scanner has proven to be an exceptional tool in quickly determining sensitivity and availability of the photocathode for operation.

  9. Attenuation correction for the NIH ATLAS small animal PET scanner

    CERN Document Server

    Yao, Rutao; Liow, JeihSan; Seidel, Jurgen

    2003-01-01

    We evaluated two methods of attenuation correction for the NIH ATLAS small animal PET scanner: 1) a CT-based method that derives 511 keV attenuation coefficients (mu) by extrapolation from spatially registered CT images; and 2) an analytic method based on the body outline of emission images and an empirical mu. A specially fabricated attenuation calibration phantom with cylindrical inserts that mimic different body tissues was used to derive the relationship to convert CT values to (I for PET. The methods were applied to three test data sets: 1) a uniform cylinder phantom, 2) the attenuation calibration phantom, and 3) a mouse injected with left bracket **1**8F right bracket FDG. The CT-based attenuation correction factors were larger in non-uniform regions of the imaging subject, e.g. mouse head, than the analytic method. The two methods had similar correction factors for regions with uniform density and detectable emission source distributions.

  10. Crop water-stress assessment using an airborne thermal scanner

    Science.gov (United States)

    Millard, J. P.; Jackson, R. D.; Reginato, R. J.; Idso, S. B.; Goettelman, R. C.

    1978-01-01

    An airborne thermal scanner was used to measure the temperature of a wheat crop canopy in Phoenix, Arizona. The results indicate that canopy temperatures acquired about an hour and a half past solar noon were well correlated with presunrise plant water tension, a parameter directly related to plant growth and development. Pseudo-colored thermal images reading directly in stress degree days, a unit indicative of crop irrigation needs and yield potential, were produced. The aircraft data showed significant within-field canopy temperature variability, indicating the superiority of the synoptic view provided by aircraft over localized ground measurements. The standard deviation between airborne and ground-acquired canopy temperatures was 2 C or less.

  11. Parameters and design considerations for tomographic transmission scanners

    International Nuclear Information System (INIS)

    Pentlow, K.S.; Beattie, J.W.; Laughlin, J.S.

    1976-01-01

    The design of transverse axial transmission scanners for reconstruction tomography involves many interrelated parameters and conflicting requirements. We have investigated some of those parameters and their interactions and, where appropriate, attempted to optimize them. It is convenient to group the considerations under four headings: (1) Geometrical factors (basic configurations, rectilinear and fan geometry, moving detectors or static arrays, spatial response variations and field uniformity, and collimation); (2) Radiation energy and sources (Considerations here include transmission versus sensitivity, detector efficiency, collimator penetration, scattered radiation, patient dose, monochromatic versus polychromatic radiation and X-ray tubes versus radionuclide sources); (3) Detection systems (types of detector, detection modes and the rejection of scatter); and (4) Reconstruction mathematics and quantum noise. As a result of such considerations we have proposed a particular design which should have advantages in certain applications

  12. Development of radioactive source scanner based on PLC

    International Nuclear Information System (INIS)

    Yang Guogui; Gao Xiang; Guo Hongli

    2013-01-01

    The radioactive radial uniformity of 68 Ge line radioactive sources is a critical quality parameter. The radioactive source scanner with linear scanning function is developed by making use of high-speed pulse counters, high-speed pulse output ports, and the powerful instruction system of Siemens S7-200 series programmable logic controller (PLC). A computer used as a host computer of the instrument communicate with. the PLC by point to point interface (PPI) protocol, The instrument with functions of data collection, transmission, displaying, saving, motion control and instrument parameter settings, can be used to measure the radioactive radial uniformity and total activity of line radioactive source. The advantages of Using the PLC to develop nuclear instrumentation are development speed, strong anti-interference ability, and low-cost. This paper mainly describes the control system implementation and feature of the instrument. (authors)

  13. Coastal Zone Color Scanner atmospheric correction algorithm - Multiple scattering effects

    Science.gov (United States)

    Gordon, Howard R.; Castano, Diego J.

    1987-01-01

    Errors due to multiple scattering which are expected to be encountered in application of the current Coastal Zone Color Scanner (CZCS) atmospheric correction algorithm are analyzed. The analysis is based on radiative transfer computations in model atmospheres, in which the aerosols and molecules are distributed vertically in an exponential manner, with most of the aerosol scattering located below the molecular scattering. A unique feature of the analysis is that it is carried out in scan coordinates rather than typical earth-sun coordinates, making it possible to determine the errors along typical CZCS scan lines. Information provided by the analysis makes it possible to judge the efficacy of the current algorithm with the current sensor and to estimate the impact of the algorithm-induced errors on a variety of applications.

  14. Cloud screening Coastal Zone Color Scanner images using channel 5

    Science.gov (United States)

    Eckstein, B. A.; Simpson, J. J.

    1991-01-01

    Clouds are removed from Coastal Zone Color Scanner (CZCS) data using channel 5. Instrumentation problems require pre-processing of channel 5 before an intelligent cloud-screening algorithm can be used. For example, at intervals of about 16 lines, the sensor records anomalously low radiances. Moreover, the calibration equation yields negative radiances when the sensor records zero counts, and pixels corrupted by electronic overshoot must also be excluded. The remaining pixels may then be used in conjunction with the procedure of Simpson and Humphrey to determine the CZCS cloud mask. These results plus in situ observations of phytoplankton pigment concentration show that pre-processing and proper cloud-screening of CZCS data are necessary for accurate satellite-derived pigment concentrations. This is especially true in the coastal margins, where pigment content is high and image distortion associated with electronic overshoot is also present. The pre-processing algorithm is critical to obtaining accurate global estimates of pigment from spacecraft data.

  15. High speed hydraulic scanner for deep x-ray lithography

    International Nuclear Information System (INIS)

    Milne, J.C.; Johnson, E.D.

    1997-07-01

    From their research and development in hard x-ray lithography, the authors have found that the conventional leadscrew driven scanner stages do not provide adequate scan speed or travel. These considerations have led the authors to develop a scanning system based on a long stroke hydraulic drive with 635 mm of travel and closed loop feedback to position the stage to better than 100 micrometers. The control of the device is through a PC with a custom LabView interface coupled to simple x-ray beam diagnostics. This configuration allows one to set a variety of scan parameters, including target dose, scan range, scan rates, and dose rate. Results from the prototype system at beamline X-27B are described as well as progress on a production version for the X-14B beamline

  16. Radiography and scanner: let us ask the right questions

    International Nuclear Information System (INIS)

    2012-07-01

    By answering simple questions, this document proposes a brief overview of radiographic and scanner-based examinations. It recalls that these both techniques use X rays, the cumulative dose of which could slightly increase a risk of cancer on a long term. It outlines that the benefits of these examinations are much more important that the related risks. It indicates the received dose (compared to a daily natural irradiation) for different kinds of examination and for different parts of the human body. It outlines the sensitivity of children to X rays, gives some recommendations regarding these examinations (they are not automatic; the doctor must explain why he chooses them, previous examinations and photos must be kept and brought with; the received dose must be specified in the examination report)

  17. High speed hydraulic scanner for deep x-ray lithography

    Energy Technology Data Exchange (ETDEWEB)

    Milne, J.C.; Johnson, E.D.

    1997-07-01

    From their research and development in hard x-ray lithography, the authors have found that the conventional leadscrew driven scanner stages do not provide adequate scan speed or travel. These considerations have led the authors to develop a scanning system based on a long stroke hydraulic drive with 635 mm of travel and closed loop feedback to position the stage to better than 100 micrometers. The control of the device is through a PC with a custom LabView interface coupled to simple x-ray beam diagnostics. This configuration allows one to set a variety of scan parameters, including target dose, scan range, scan rates, and dose rate. Results from the prototype system at beamline X-27B are described as well as progress on a production version for the X-14B beamline.

  18. Use of ocean color scanner data in water quality mapping

    Science.gov (United States)

    Khorram, S.

    1981-01-01

    Remotely sensed data, in combination with in situ data, are used in assessing water quality parameters within the San Francisco Bay-Delta. The parameters include suspended solids, chlorophyll, and turbidity. Regression models are developed between each of the water quality parameter measurements and the Ocean Color Scanner (OCS) data. The models are then extended to the entire study area for mapping water quality parameters. The results include a series of color-coded maps, each pertaining to one of the water quality parameters, and the statistical analysis of the OCS data and regression models. It is found that concurrently collected OCS data and surface truth measurements are highly useful in mapping the selected water quality parameters and locating areas having relatively high biological activity. In addition, it is found to be virtually impossible, at least within this test site, to locate such areas on U-2 color and color-infrared photography.

  19. Optofluidic laser scanner based on a rotating liquid prism.

    Science.gov (United States)

    Kopp, Daniel; Lehmann, Lukas; Zappe, Hans

    2016-03-20

    We demonstrate an electrowetting-actuated optofluidic system based on a rotatable liquid prism implemented as a two-dimensional laser scanner. The system is fabricated through a novel technology using a patterned flexible polymeric foil on which a high density of electrodes is structured and which is subsequently inserted into a cylindrical housing. The resulting radial electrode array is used for electrowetting actuation of two fluids filled into the cylinder, which allows a controllable tilt and orientation of the planar liquid interface and thus represents a tunable rotating prism. Finite element simulations and subsequent experimental verification show that this highly planar and precisely positionable liquid/liquid interface may be actuated to a deflection angle of ±6.4°, with a standard deviation of ±0.18°, and rotated 360° about the vertical axis. Power consumption is limited to several microwatts, and switching times of several hundred milliseconds were determined.

  20. ARIES segmented gamma-ray scanner user manual

    International Nuclear Information System (INIS)

    Biddle, R.S.; Sheppard, G.A.; Schneider, C.M.

    1998-01-01

    The segmented gamma-ray scatter (SGS) designated as Win SGS at the Los Alamos Plutonium Facility has been installed and is intended for use in quantifying the radioisotope content of DOE-STD-3013-96 equivalent containers. The SGS features new software written in C and a new user interface that runs under Microsoft Windows trademark. The operation of the ARIES Segmented Gamma-ray Scanner is documented in this manual. It covers user instructions as well as hardware and software details. Additional information is found in the documentation for the commercially available components and modules that compose the SGS. The objective of the ARIES project is to demonstrate technology to dismantle plutonium pits from excess nuclear weapons, convert the plutonium to a metal ingot or an oxide powder, package the metal or oxide, and verify the contents of the package by nondestructive assay

  1. Intracardiac ultrasound scanner using a micromachine (MEMS) actuator.

    Science.gov (United States)

    Zara, J M; Bobbio, S M; Goodwin-Johansson, S; Smith, S W

    2000-01-01

    Catheter-based intracardiac ultrasound offers the potential for improved guidance of interventional cardiac procedures. The objective of this research is the development of catheter-based mechanical sector scanners incorporating high frequency ultrasound transducers operating at frequencies up to 20 MHz. The authors' current transducer assembly consists of a single 1.75 mm by 1.75 mm, 20 MHz, PZT element mounted on a 2 mm by 2 mm square, 75 mum thick polyimide table that pivots on 3-mum thick gold plated polyimide hinges. The hinges also serve as the electrical connections to the transducer. This table-mounted transducer is tilted using a miniature linear actuator to produce a sector scan. This linear actuator is an integrated force array (IFA), which is an example of a micromachine, i.e., a microelectromechanical system (MEMS). The IFA is a thin (2.2 mum) polyimide membrane, which consists of a network of hundreds of thousands of micron scale deformable capacitors made from pairs of metallized polyimide plates. IFAs contract with an applied voltage of 30-120 V and have been shown to produce strains as large as 20% and forces of up to 8 dynes. The prototype transducer and actuator assembly was fabricated and interfaced with a GagePCI analog to digital conversion board digitizing 12 bit samples at a rate of 100 MSamples/second housed in a personal computer to create a single channel ultrasound scanner. The deflection of the table transducer in a low viscosity insulating fluid (HFE 7100, 3M) is up to +/-10 degrees at scan rates of 10-60 Hz. Software has been developed to produce real-time sector scans on the PC monitor.

  2. Effective dose range for dental cone beam computed tomography scanners

    International Nuclear Information System (INIS)

    Pauwels, Ruben; Beinsberger, Jilke; Collaert, Bruno; Theodorakou, Chrysoula; Rogers, Jessica; Walker, Anne; Cockmartin, Lesley; Bosmans, Hilde; Jacobs, Reinhilde; Bogaerts, Ria; Horner, Keith

    2012-01-01

    Objective: To estimate the absorbed organ dose and effective dose for a wide range of cone beam computed tomography scanners, using different exposure protocols and geometries. Materials and methods: Two Alderson Radiation Therapy anthropomorphic phantoms were loaded with LiF detectors (TLD-100 and TLD-100H) which were evenly distributed throughout the head and neck, covering all radiosensitive organs. Measurements were performed on 14 CBCT devices: 3D Accuitomo 170, Galileos Comfort, i-CAT Next Generation, Iluma Elite, Kodak 9000 3D, Kodak 9500, NewTom VG, NewTom VGi, Pax-Uni3D, Picasso Trio, ProMax 3D, Scanora 3D, SkyView, Veraviewepocs 3D. Effective dose was calculated using the ICRP 103 (2007) tissue weighting factors. Results: Effective dose ranged between 19 and 368 μSv. The largest contributions to the effective dose were from the remainder tissues (37%), salivary glands (24%), and thyroid gland (21%). For all organs, there was a wide range of measured values apparent, due to differences in exposure factors, diameter and height of the primary beam, and positioning of the beam relative to the radiosensitive organs. Conclusions: The effective dose for different CBCT devices showed a 20-fold range. The results show that a distinction is needed between small-, medium-, and large-field CBCT scanners and protocols, as they are applied to different indication groups, the dose received being strongly related to field size. Furthermore, the dose should always be considered relative to technical and diagnostic image quality, seeing that image quality requirements also differ for patient groups. The results from the current study indicate that the optimisation of dose should be performed by an appropriate selection of exposure parameters and field size, depending on the diagnostic requirements.

  3. An MRI-Conditional External Cardiac Defibrillator for Resuscitation Within the MRI Scanner Bore

    Science.gov (United States)

    Schmidt, Ehud J.; Watkins, Ronald D.; Zviman, Menekhem M.; Guttman, Michael A.; Wang, Wei; Halperin, Henry A.

    2016-01-01

    Background Subjects undergoing cardiac arrest within an MRI scanner are currently removed from the bore and then from the MRI suite, prior to delivery of CPR and defibrillation, potentially increasing risk of mortality. This precludes many higher-risk (acute-ischemic, acute-stroke) patients from undergoing MRI imaging and MRI-guided intervention. An MRI-conditional cardiac defibrillator should enable scanning with defibrillation pads attached and the generator ON, enabling application of defibrillation within the MRI seconds after a cardiac event. An MRI-conditional external defibrillator may improve patient acceptance for MRI procedures. Methods and Results A commercial external defibrillator was rendered 1.5 Tesla MRI-conditional by addition of novel Radio-Frequency (RF) filters between the generator and commercial disposable surface-pads. The RF filters reduced emission into the MRI scanner, and prevented cable/surface-pad heating during imaging, while preserving all the defibrillator’s monitoring and delivery functions. Human volunteers were imaged using high Specific-Absorption-Rate sequences to validate MRI image quality (IQ) and lack of heating. Swine were electrically fibrillated (N=4) and thereafter defibrillated both outside and inside the MRI bore. MRI IQ was reduced by 0.8 or 1.6 dB, with the generator in monitoring mode and operating on battery or AC power, respectively. Commercial surface-pads did not create artifacts deeper than 6mm below the skin surface. RF heating was within FDA guidelines. Defibrillation was completely successful inside and outside the MRI bore. Conclusions A prototype MRI-conditional defibrillation system successfully defibrillated in the MRI without degrading image quality, or increasing the time needed for defibrillation. It can increase patient acceptance for MRI procedures. PMID:27729363

  4. Acoustic pressure waves induced in human heads by RF pulses from high-field MRI scanners.

    Science.gov (United States)

    Lin, James C; Wang, Zhangwei

    2010-04-01

    The current evolution toward greater image resolution from magnetic resonance image (MRI) scanners has prompted the exploration of higher strength magnetic fields and use of higher levels of radio frequencies (RFs). Auditory perception of RF pulses by humans has been reported during MRI with head coils. It has shown that the mechanism of interaction for the auditory effect is caused by an RF pulse-induced thermoelastic pressure wave inside the head. We report a computational study of the intensity and frequency of thermoelastic pressure waves generated by RF pulses in the human head inside high-field MRI and clinical scanners. The U.S. Food and Drug Administration (U.S. FDA) guides limit the local specific absorption rate (SAR) in the body-including the head-to 8 W kg(-1). We present results as functions of SAR and show that for a given SAR the peak acoustic pressures generated in the anatomic head model were essentially the same at 64, 300, and 400 MHz (1.5, 7.0, and 9.4 T). Pressures generated in the anatomic head are comparable to the threshold pressure of 20 mPa for sound perception by humans at the cochlea for 4 W kg(-1). Moreover, results indicate that the peak acoustic pressure in the brain is only 2 to 3 times the auditory threshold at the U.S. FDA guideline of 8 W kg(-1). Even at a high SAR of 20 W kg(-1), where the acoustic pressure in the brain could be more than 7 times the auditory threshold, the sound pressure levels would not be more than 17 db above threshold of perception at the cochlea.

  5. Continued Development Of An Inexpensive Simulator Based CT Scanner For Radiation Therapy Treatment Planning

    Science.gov (United States)

    Peschmann, K. R.; Parker, D. L.; Smith, V.

    1982-11-01

    An abundant number of different CT scanner models has been developed in the past ten years, meeting increasing standards of performance. From the beginning they remained a comparatively expensive piece of equipment. This is due not only to their technical complexity but is also due to the difficulties involved in assessing "true" specifications (avoiding "overde-sign"). Our aim has been to provide, for Radiation Therapy Treatment Planning, a low cost CT scanner system featuring large freedom in patient positioning. We have taken advantage of the concurrent tremendously increased amount of knowledge and experience in the technical area of CT1 . By way of extensive computer simulations we gained confidence that an inexpensive C-arm simulator gantry and a simple one phase-two pulse generator in connection with a standard x-ray tube could be used, without sacrificing image quality. These components have been complemented by a commercial high precision shaft encoder, a simple and effective fan beam collimator, a high precision, high efficiency, luminescence crystal-silicon photodiode detector with 256 channels, low noise electronic preamplifier and sampling filter stages, a simplified data aquisition system furnished by Toshiba/ Analogic and an LSI 11/23 microcomputer plus data storage disk as well as various smaller interfaces linking the electrical components. The quality of CT scan pictures of phantoms,performed by the end of last year confirmed that this simple approach is working well. As a next step we intend to upgrade this system with an array processor in order to shorten recon-struction time to one minute per slice. We estimate that the system including this processor could be manufactured for a selling price of $210,000.

  6. Absolute dosimetric characterization of Gafchromic EBT3 and HDv2 films using commercial flat-bed scanners and evaluation of the scanner response function variability

    Energy Technology Data Exchange (ETDEWEB)

    Chen, S. N.; Revet, G.; Fuchs, J. [LULI-CNRS, Ecole Polytechnique, CEA: Universite Paris-Saclay, UPMC Univ Paris 06, Sorbonne Universities, F-91128 Palaiseau Cedex (France); Institute of Applied Physics, 46 Ulyanov Street, 603950 Nizhny Novgorod (Russian Federation); Gauthier, M.; Glenzer, S.; Propp, A. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Bazalova-Carter, M. [Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8P 5C2 (Canada); Bolanos, S. [LULI-CNRS, Ecole Polytechnique, CEA: Universite Paris-Saclay, UPMC Univ Paris 06, Sorbonne Universities, F-91128 Palaiseau Cedex (France); Riquier, R. [LULI-CNRS, Ecole Polytechnique, CEA: Universite Paris-Saclay, UPMC Univ Paris 06, Sorbonne Universities, F-91128 Palaiseau Cedex (France); CEA, DAM, DIF, F-91297 Arpajon (France); Antici, P. [INRS-EMT, Varennes, J3X1S2 Québec (Canada); Morabito, A. [ELI-ALPS, ELI-HU non profit kft, Dugonics ter 13, H-6720, Szeged (Hungary); Starodubtsev, M. [Institute of Applied Physics, 46 Ulyanov Street, 603950 Nizhny Novgorod (Russian Federation)

    2016-07-15

    Radiochromic films (RCF) are commonly used in dosimetry for a wide range of radiation sources (electrons, protons, and photons) for medical, industrial, and scientific applications. They are multi-layered, which includes plastic substrate layers and sensitive layers that incorporate a radiation-sensitive dye. Quantitative dose can be retrieved by digitizing the film, provided that a prior calibration exists. Here, to calibrate the newly developed EBT3 and HDv2 RCFs from Gafchromic™, we used the Stanford Medical LINAC to deposit in the films various doses of 10 MeV photons, and by scanning the films using three independent EPSON Precision 2450 scanners, three independent EPSON V750 scanners, and two independent EPSON 11000XL scanners. The films were scanned in separate RGB channels, as well as in black and white, and film orientation was varied. We found that the green channel of the RGB scan and the grayscale channel are in fact quite consistent over the different models of the scanner, although this comes at the cost of a reduction in sensitivity (by a factor ∼2.5 compared to the red channel). To allow any user to extend the absolute calibration reported here to any other scanner, we furthermore provide a calibration curve of the EPSON 2450 scanner based on absolutely calibrated, commercially available, optical density filters.

  7. [Practicability of the mobile one-finger scanner Cross Match MV5 in fingerprinting of corpses: are mobile fingerprinting scanners suitable for use in mass disasters?].

    Science.gov (United States)

    Breitmeier, Dirk; Landmesser, Britta; Schulz, Yvonne; Albrecht, Knut

    2008-01-01

    Dactyloscopy is a special field in the police records department and a suitable means for identifying unknown dead persons as well as solving crimes by taking fingerprints from living persons. Apart from the conventional methods of dactyloscopy, mobile and more compact instruments are to facilitate taking prints of fingertips and palms also at the scene of mass disasters. In the presented study, living persons and corpses were examined to find out the possible uses and limits of mobile one-finger scanners. The concrete issue of the investigation was whether the mobile one-finger scanner Cross Match MV5 is suitable for application in mass disasters. The device was used in 12 corpses aged 5 weeks to 76 years (mean postmortem interval 5.5 days) and in 28 living persons aged 6 weeks to 87 years. In summary, the scanner produced qualitatively good prints in all age groups of the living individuals. In the corpses, the prints were only partly evaluable. In particular, fingers and fingertips with soot blackening and livid discoloration were difficult to analyse. Postmortem rigidity also complicated the handling of the scanner. In fresh corpses, the scanner can be recommended without reservation. Even if the epidermis was detached, the scanner was able to produce evaluable prints of the dermis of the hypothenar.

  8. Information Literacy and Employability

    OpenAIRE

    O'Keeffe, Colin

    2016-01-01

    Information Literacy (IL) and its relationship to third level graduates’ employability has gained more attention in recent years. This article examines how IL has evolved from skills initially associated with academic libraries into a key workplace skill set of the knowledge economy. It outlines the challenges interviewees encounter when selling IL to employers, how IL can be utilised when preparing for upcoming interviews and suggests a distinction between workplace IL and employability IL. ...

  9. General Outside Employment

    Data.gov (United States)

    Montgomery County of Maryland — This dataset contains all outside employment requests held by employees of Montgomery County (excluding uniformed police officer) approved by the Ethics Commission...

  10. Secretary Marshall's Employment Strategies

    Science.gov (United States)

    Stevenson, Gloria

    1977-01-01

    A review of proposed employment strategies and priorities of Ray Marshall, Secretary of Labor, with regard to training programs, governmental subsidy programs, apprenticeships, private sector jobs, etc. (WL)

  11. Institutionalized Employer Collective Action

    DEFF Research Database (Denmark)

    Ibsen, Christian Lyhne; Navrbjerg, Steen Erik

    2016-01-01

    Recent studies show that employer associations continue to exist in new ways despite internationalisation of the economy, liberalisation of markets and the decline of trade unions. This paradox raises two questions regarding EOs in today’s labour markets: Which employers join employer associations...... and what kind of services do EOs offer employers? This article explores these questions using two comprehensive surveys on EOs in Denmark – a prominent case of coordinated market economies. The main finding of the analyses is that collective activities vis-à-vis trade unions and government are still...

  12. FormScanner: Open-Source Solution for Grading Multiple-Choice Exams

    Science.gov (United States)

    Young, Chadwick; Lo, Glenn; Young, Kaisa; Borsetta, Alberto

    2016-01-01

    The multiple-choice exam remains a staple for many introductory physics courses. In the past, people have graded these by hand or even flaming needles. Today, one usually grades the exams with a form scanner that utilizes optical mark recognition (OMR). Several companies provide these scanners and particular forms, such as the eponymous…

  13. Validity and Repeatability of the Sizestream 3D Scanner and Poikos Modeling System

    NARCIS (Netherlands)

    Vonk, T.E.; Daanen, H.A.M.

    2015-01-01

    Three-dimensional (3D) body scanning becomes increasingly important in the medical, ergonomical and apparel industry. The SizeStream 3D body scanner is a 3D body scanner in the shape of a fitting room that can generate a 3D copy of the human body in a few seconds. The Poikos modeling system

  14. Application of intra-oral dental scanners in the digital workflow of implantology

    NARCIS (Netherlands)

    van der Meer, Wicher J; Andriessen, Frank S; Wismeijer, Daniel; Ren, Yijin

    2012-01-01

    UNLABELLED: Intra-oral scanners will play a central role in digital dentistry in the near future. In this study the accuracy of three intra-oral scanners was compared. MATERIALS AND METHODS: A master model made of stone was fitted with three high precision manufactured PEEK cylinders and scanned

  15. Digitisation of electron microscope films: Six useful tests applied to three film scanners

    International Nuclear Information System (INIS)

    Henderson, R.; Cattermole, D.; McMullan, G.; Scotcher, S.; Fordham, M.; Amos, W.B.; Faruqi, A.R.

    2007-01-01

    A series of simple tests have been used to measure the performance of flat-bed film scanners suitable for digitisation of electron micrographs. Two of the film scanners evaluated are commercially available and one has been constructed in the laboratory paying special attention to the needs of the electron microscopist. The tests may be useful for others

  16. Accuracy and reproducibility of the DAVID SLS-2 scanner in three-dimensional facial imaging

    DEFF Research Database (Denmark)

    Secher, Jesper Jared; Darvann, Tron Andre; Pinholt, Else Marie

    2017-01-01

    PURPOSE: A prospective study was performed to test the accuracy and reproducibility of the DAVID-SLS-2 scanner (SLS-2) [DAVID Vision Systems GmbH], compared to the validated 3dMDtrio scanner (3dMD) [3dMD, LLC, Atlanta, GA, USA]. MATERIALS AND METHODS: The accuracy of the SLS-2 was determined thro...

  17. Scanner Uniformity improvements for radiochromic film analysis with matt reflectance backing

    International Nuclear Information System (INIS)

    Butson, M.; Yu, P.K.N.

    2011-01-01

    Full text: A simple and reproducible method for increasing desktop scanner uniformity for the analysis of radiochromic films is presented. Scanner uniformity, especially in the non-scan direction, for transmission scanning is well known to be problematic for radiochromic film analysis and normally corrections need to be applied. These corrections are dependant on scanner coordinates and dose level applied which complicates dosimetry procedures. This study has highlighted that using reflectance scanning in combination with a matt, white backing material instead of the conventional gloss scanner finish, substantial increases in the scanner uniformity can be achieved within 90% of the scanning area. Uniformity within ±I% over the scanning area for our epsonV700 scanner tested was found. This is compared to within ±3% for reflection scanning with the gloss backing material and within ±4% for transmission scanning. The matt backing material used was simply 5 layers of standard quality white printing paper (80 g/m It was found that 5 layers was the optimal result for backing material however most of the improvements were seen with a minimum of 3 layers. Above 5 layers, no extra benefit was seen. This may eliminate the need to perform scanner corrections for position on the desktop scanners for radiochromic film dosimetry. (author)

  18. Implementation of a versatile research data acquisition system using a commercially available medical ultrasound scanner

    DEFF Research Database (Denmark)

    Hemmsen, Martin Christian; Nikolov, Svetoslav Ivanov; Pedersen, Mads Møller

    2012-01-01

    to the clinic. The system consists of a standard PC equipped with a camera link and an ultrasound scanner equipped with a research interface. The ultrasound scanner is an easy-to-use imaging device that is capable of generating high-quality images. In addition to supporting the acquisition of multiple data...

  19. Accuracy of four different digital intraoral scanners: effects of the presence of orthodontic brackets and wire.

    Science.gov (United States)

    Jung, Yoo-Ran; Park, Ji-Man; Chun, Youn-Sic; Lee, Kkot-Nim; Kim, Minji

    The objective of this study was to compare the accuracy of four different digital intraoral scanners and the effects of buccal brackets and orthodontic wire. For this study, three sets of models (Control model, BKT model with buccal bracket, and WBKT model with buccal bracket and orthodontic wire) were scanned using four different types of intraoral scanners: E4D dentist, iTero, Trios, and Zfx IntraScan. The mesiodistal width of the teeth, intercanine width, and intermolar width measured by four scanners were compared. Three-dimensional (3D) images of the brackets were taken using the four scanners. Data were analyzed with one-way ANOVA, independent t test, and post-hoc Tukey test at a significance level of P brackets and orthodontic wire. Comparison of 3D bracket images scanned by the four scanners showed differences in image distortion among the scanners. Bracket characteristics did not affect the 3D bracket images. The four intraoral scanners used in this study differed in accuracy. However, the results acquired by iTero and Trios were more reliable. Effects of buccal brackets and orthodontic wire on the 3D images taken by intraoral scanners were not clinically significant.

  20. Accuracy of automated volumetry of pulmonary nodules across different multislice CT scanners

    International Nuclear Information System (INIS)

    Das, Marco; Muehlenbruch, Georg; Mahnken, Andreas H.; Katoh, Markus; Guenther, Rolf W.; Wildberger, Joachim E.; Ley-Zaporozhan, Julia; Kauczor, Hans-Ulrich; Gietema, H.A.; Prokop, Mathias; Czech, Andre; Diederich, Stefan; Bakai, Annemarie; Salganicoff, Marcos

    2007-01-01

    The purpose of this study was to compare the accuracy of an automated volumetry software for phantom pulmonary nodules across various 16-slice multislice spiral CT (MSCT) scanners from different vendors. A lung phantom containing five different nodule categories (intraparenchymal, around a vessel, vessel attached, pleural, and attached to the pleura), with each category comprised of 7-9 nodules (total, n = 40) of varying sizes (diameter 3-10 mm; volume 6.62 mm 3 -525 mm 3 ), was scanned with four different 16-slice MSCT scanners (Siemens, GE, Philips, Toshiba). Routine and low-dose chest protocols with thin and thick collimations were applied. The data from all scanners were used for further analysis using a dedicated prototype volumetry software. Absolute percentage volume errors (APE) were calculated and compared. The mean APE for all nodules was 8.4% (±7.7%) for data acquired with the 16-slice Siemens scanner, 14.3% (±11.1%) for the GE scanner, 9.7% (±9.6%) for the Philips scanner and 7.5% (±7.2%) for the Toshiba scanner, respectively. The lowest APEs were found within the diameter size range of 5-10 mm and volumes >66 mm 3 . Nodule volumetry is accurate with a reasonable volume error in data from different scanner vendors. This may have an important impact for intraindividual follow-up studies. (orig.)

  1. Computer-aided analysis of digital dental impressions obtained from intraoral and extraoral scanners.

    Science.gov (United States)

    Bohner, Lauren Oliveira Lima; De Luca Canto, Graziela; Marció, Bruno Silva; Laganá, Dalva Cruz; Sesma, Newton; Tortamano Neto, Pedro

    2017-11-01

    The internal and marginal adaptation of a computer-aided design and computer-aided manufacturing (CAD-CAM) prosthesis relies on the quality of the 3-dimensional image. The quality of imaging systems requires evaluation. The purpose of this in vitro study was to evaluate and compare the trueness of intraoral and extraoral scanners in scanning prepared teeth. Ten acrylic resin teeth to be used as a reference dataset were prepared according to standard guidelines and scanned with an industrial computed tomography system. Data were acquired with 4 scanner devices (n=10): the Trios intraoral scanner (TIS), the D250 extraoral scanner (DES), the Cerec Bluecam intraoral scanner (CBIS), and the Cerec InEosX5 extraoral scanner (CIES). For intraoral scanners, each tooth was digitized individually. Extraoral scanning was obtained from dental casts of each prepared tooth. The discrepancy between each scan and its respective reference model was obtained by deviation analysis (μm) and volume/area difference (μm). Statistical analysis was performed using linear models for repeated measurement factors test and 1-way ANOVA (α=.05). No significant differences in deviation values were found among scanners. For CBIS and CIES, the deviation was significantly higher (PDentistry. Published by Elsevier Inc. All rights reserved.

  2. Application of intra-oral dental scanners in the digital workflow of implantology

    NARCIS (Netherlands)

    van der Meer, W.J.; Andriessen, F.S.; Wismeijer, D.; Ren, Y.

    2012-01-01

    Intra-oral scanners will play a central role in digital dentistry in the near future. In this study the accuracy of three intra-oral scanners was compared. Materials and methods: A master model made of stone was fitted with three high precision manufactured PEEK cylinders and scanned with three

  3. Evaluation of wedge-shaped phantoms for assessment of scanner display as a part of quality control of scanner performance

    International Nuclear Information System (INIS)

    Bergmann, H.; Havlik, E.

    1981-01-01

    Image manipulation in modern rectilinear scanners comprises background subtraction and contrast enhancement facilities. It has been the aim of this investigation to develop simple quality assurance methods suitable for checking the function of these features on a routine basis. Several types of phantoms have been investigated: an absorption step wedge, an emission step wedge and an emission continuous wedge. The absorption step wedge when used with a usual gamma-camera checking source gave the least satisfactory results. The emission step wedge is best suited for test procedures for background subtraction of the colour printer display and for contrast enhancement of the photo display, whereas the emission continuous wedge gave best results in testing the contrast enhancement of the colour printer display. An evaluation of the relative merits of the phantoms indicates that the emission step wedge is best suited for quality assurance tests. (author)

  4. Cardiac imaging systems and methods employing computerized tomographic scanning

    International Nuclear Information System (INIS)

    Richey, J.B.; Wake, R.H.; Walters, R.G.; Hunt, W.F.; Cool, S.L.

    1980-01-01

    The invention relates to cardiac imaging systems and methods employing computerised tomographic scanning. Apparatus is described which allows an image of the radiation attenuation of the heart at a desired phase of the cardiac cycle. The patients ECG signal can be used in a transverse-and-rotate type CT scanner as a time base, so that the beam reaches the heart at a desired phase of the cardiac cycle, or, in a purely rotational-type CT scanner continuously generated scan data is only stored for corresponding phases of successive cardiac cycles. Alternatively, gating of the beams themselves by shuttering or switching the power supply can be controlled by the ECG signal. A pacemaker is used to stabilize the cardiac period. Also used is a system for recognising unacceptable variations in the cardiac period and discarding corresponding scan data. In a transverse-and-rotate type fan-beam CT scanner, the effective beam width is narrowed to reduce the duration of the traverse of the heart. (U.K.)

  5. Out of lab calibration of a rotating 2D scanner for 3D mapping

    Science.gov (United States)

    Koch, Rainer; Böttcher, Lena; Jahrsdörfer, Maximilian; Maier, Johannes; Trommer, Malte; May, Stefan; Nüchter, Andreas

    2017-06-01

    Mapping is an essential task in mobile robotics. To fulfil advanced navigation and manipulation tasks a 3D representation of the environment is required. Applying stereo cameras or Time-of-flight cameras (TOF cameras) are one way to archive this requirement. Unfortunately, they suffer from drawbacks which makes it difficult to map properly. Therefore, costly 3D laser scanners are applied. An inexpensive way to build a 3D representation is to use a 2D laser scanner and rotate the scan plane around an additional axis. A 3D point cloud acquired with such a custom device consists of multiple 2D line scans. Therefore the scanner pose of each line scan need to be determined as well as parameters resulting from a calibration to generate a 3D point cloud. Using external sensor systems are a common method to determine these calibration parameters. This is costly and difficult when the robot needs to be calibrated outside the lab. Thus, this work presents a calibration method applied on a rotating 2D laser scanner. It uses a hardware setup to identify the required parameters for calibration. This hardware setup is light, small, and easy to transport. Hence, an out of lab calibration is possible. Additional a theoretical model was created to test the algorithm and analyse impact of the scanner accuracy. The hardware components of the 3D scanner system are an HOKUYO UTM-30LX-EW 2D laser scanner, a Dynamixel servo-motor, and a control unit. The calibration system consists of an hemisphere. In the inner of the hemisphere a circular plate is mounted. The algorithm needs to be provided with a dataset of a single rotation from the laser scanner. To achieve a proper calibration result the scanner needs to be located in the middle of the hemisphere. By means of geometric formulas the algorithms determine the individual deviations of the placed laser scanner. In order to minimize errors, the algorithm solves the formulas in an iterative process. First, the calibration algorithm was

  6. Performance on a CT Scanner. Application for the dose correction in the presence of heterogeneities, experimental study using high energy photon beams

    International Nuclear Information System (INIS)

    Hanna, Therese.

    1979-01-01

    The purpose of this work is the physical analysis of a second generation C T scanner: the A C T A Scanner 0200 FS (PFIZER) used at the 'Institut Gustave Roussy, Villejuif' and its application in radiotherapy. The first part of the study specifically concerns the physical performance of the C T Scanner, and, the evaluation of the doses, delivered to patients during tomodensitometric examinations. The second part envisages the possibilities of the application of C T scanning in radiotherapy. A particular study is established for the utilization of the physical characteristics, furnished by the C T Scanner, concerning different organs, in dose calculations, in the presence of heterogeneities. An experimental study using high energy photon beams more particularly 25 MV X ray beams produced by a linear accelerator (type Sagittaire) has been realized with materials, simulating different human tissues. Consequently, the validity of different correction methods proposed in the literature has been tested for the soft tissues and bone as for the lungs. Modifications are suggested to allow the use of these methods for the photons of very high energy [fr

  7. Bladder filling variation during radiation treatment of prostate cancer: Can the use of a bladder ultrasound scanner and biofeedback optimize bladder filling?

    International Nuclear Information System (INIS)

    Stam, Marcel R.; Lin, Emile N.J. Th. van; Vight, Lisette P. van der; Kaanders, Johannes; Visser, Andries G.

    2006-01-01

    Purpose: To investigate the use of a bladder ultrasound scanner in achieving a better reproducible bladder filling during irradiation of pelvic tumors, specifically prostate cancer. Methods and Materials: First, the accuracy of the bladder ultrasound scanner relative to computed tomography was validated in a group of 26 patients. Next, daily bladder volume variation was evaluated in a group of 18 patients. Another 16 patients participated in a biofeedback protocol, aiming at a more constant bladder volume. The last objective was to study correlations between prostate motion and bladder filling, by using electronic portal imaging device data on implanted gold markers. Results: A strong correlation between bladder scanner volume and computed tomography volume (r = 0.95) was found. Daily bladder volume variation was very high (1 Sd = 47.2%). Bladder filling and daily variation did not significantly differ between the control and the feedback group (47.2% and 40.1%, respectively). Furthermore, no linear correlations between bladder volume variation and prostate motion were found. Conclusions: This study shows large variations in daily bladder volume. The use of a biofeedback protocol yields little reduction in bladder volume variation. Even so, the bladder scanner is an easy to use and accurate tool to register these variations

  8. Design and use of the IR gas-cloud scanner for measurement and imaging of the spatial distribution of gases at workplaces

    Science.gov (United States)

    ter Kuile, Willem M.; van Veen, J. J.; Knoll, Bas

    1995-02-01

    Usual sampling methods and instruments for checking compliance with `threshold limit values' (TLV) of gaseous components do not provide much information on the mechanism which caused the measured workday average concentration. In the case of noncompliance this information is indispensable for the design of cost effective measures. The infrared gas cloud (IGC) scanner visualizes the spatial distribution of specific gases at a workplace in a quantitative image with a calibrated grayvalue scale. This helps to find the cause of an over- exposure, and so it permits effective abatement of high exposures in the working environment. This paper deals with the technical design of the IGC scanner. Its use is illustrated by some real-world problems. The measuring principle and the technical operation of the IGC-scanner are described. Special attention is given to the pros and cons of retro-reflector screens, the noise reduction methods and image presentation and interpretation. The latter is illustrated by the images produced by the measurements. Essentially the IGC scanner can be used for selective open-path measurement of all gases with a concentration in the ppm range and sufficiently strong distinct absorption lines in the infrared region between 2.5 micrometers and 14.0 micrometers . Further it could be useful for testing the efficiency of ventilation systems and the remote detection of gas leaks. We conclude that a new powerful technique has been added to the industrial hygiene facilities for controlling and improving the work environment.

  9. High-speed two-dimensional laser scanner based on Bragg gratings stored in photothermorefractive glass.

    Science.gov (United States)

    Yaqoob, Zahid; Arain, Muzammil A; Riza, Nabeel A

    2003-09-10

    A high-speed free-space wavelength-multiplexed optical scanner with high-speed wavelength selection coupled with narrowband volume Bragg gratings stored in photothermorefractive (PTR) glass is reported. The proposed scanner with no moving parts has a modular design with a wide angular scan range, accurate beam pointing, low scanner insertion loss, and two-dimensional beam scan capabilities. We present a complete analysis and design procedure for storing multiple tilted Bragg-grating structures in a single PTR glass volume (for normal incidence) in an optimal fashion. Because the scanner design is modular, many PTR glass volumes (each having multiple tilted Bragg-grating structures) can be stacked together, providing an efficient throughput with operations in both the visible and the infrared (IR) regions. A proof-of-concept experimental study is conducted with four Bragg gratings in independent PTR glass plates, and both visible and IR region scanner operations are demonstrated.

  10. The development of a mobile CT-scanner gantry for use in the operating room

    International Nuclear Information System (INIS)

    Okudera, Hiroshi; Kobayashi, Shigeaki; Koike, Jouji; Harada, Takanobu; Kanemaru, Kei

    1989-01-01

    We report the development of a mobile CT-scanner gantry which uses a gantry platter. This system has been developed for use in the operating room. We designed a small lift to move the gantry unit of the scanner: the gantry carrier. The scanner gantry is fixed to the gantry carrier. A phantom test with a digitalized operating table worked well in the laboratory, and operating-room use showed that there was no deterioration in image quality. The mobile gantry system has been developed to increase the efficiency of the operating CT-scanner system. This system enables us to obtain CT images during surgery of immediately after surgery in the operating room, i.e., in cases that are not transferable to the radiological department. The operability is basically the same as that of a conventional mobile X-ray unit. Theoretically, this unit could be used with any CT scanner and in any operating room. (author)

  11. SU-E-P-11: Comparison of Image Quality and Radiation Dose Between Different Scanner System in Routine Abdomen CT

    Energy Technology Data Exchange (ETDEWEB)

    Liao, S; Wang, Y; Weng, H [Chiayi Chang Gung Memorial Hospital of The C.G.M.F, Puzi City, Chiayi County, Taiwan (China)

    2015-06-15

    Purpose To evaluate image quality and radiation dose of routine abdomen computed tomography exam with the automatic current modulation technique (ATCM) performed in two different brand 64-slice CT scanners in our site. Materials and Methods A retrospective review of routine abdomen CT exam performed with two scanners; scanner A and scanner B in our site. To calculate standard deviation of the portal hepatic level with a region of interest of 12.5 mm x 12.5mm represented to the image noise. The radiation dose was obtained from CT DICOM image information. Using Computed tomography dose index volume (CTDIv) to represented CT radiation dose. The patient data in this study were with normal weight (about 65–75 Kg). Results The standard deviation of Scanner A was smaller than scanner B, the scanner A might with better image quality than scanner B. On the other hand, the radiation dose of scanner A was higher than scanner B(about higher 50–60%) with ATCM. Both of them, the radiation dose was under diagnostic reference level. Conclusion The ATCM systems in modern CT scanners can contribute a significant reduction in radiation dose to the patient. But the reduction by ATCM systems from different CT scanner manufacturers has slightly variation. Whatever CT scanner we use, it is necessary to find the acceptable threshold of image quality with the minimum possible radiation exposure to the patient in agreement with the ALARA principle.

  12. SU-E-P-11: Comparison of Image Quality and Radiation Dose Between Different Scanner System in Routine Abdomen CT

    International Nuclear Information System (INIS)

    Liao, S; Wang, Y; Weng, H

    2015-01-01

    Purpose To evaluate image quality and radiation dose of routine abdomen computed tomography exam with the automatic current modulation technique (ATCM) performed in two different brand 64-slice CT scanners in our site. Materials and Methods A retrospective review of routine abdomen CT exam performed with two scanners; scanner A and scanner B in our site. To calculate standard deviation of the portal hepatic level with a region of interest of 12.5 mm x 12.5mm represented to the image noise. The radiation dose was obtained from CT DICOM image information. Using Computed tomography dose index volume (CTDIv) to represented CT radiation dose. The patient data in this study were with normal weight (about 65–75 Kg). Results The standard deviation of Scanner A was smaller than scanner B, the scanner A might with better image quality than scanner B. On the other hand, the radiation dose of scanner A was higher than scanner B(about higher 50–60%) with ATCM. Both of them, the radiation dose was under diagnostic reference level. Conclusion The ATCM systems in modern CT scanners can contribute a significant reduction in radiation dose to the patient. But the reduction by ATCM systems from different CT scanner manufacturers has slightly variation. Whatever CT scanner we use, it is necessary to find the acceptable threshold of image quality with the minimum possible radiation exposure to the patient in agreement with the ALARA principle

  13. Evaluation of New Inorganic Scintillators for Application in a Prototype Small Animal PET Scanner

    CERN Document Server

    Kuntner, C

    2003-01-01

    In the study of new pharmaceuticals as well as brain and genetic research, Positron Emission Tomography (PET) is a useful method. It has also recently entered the clinical domain in cardiology and particularly in oncology. Small animals such as mice, are often used to validate sophisticated models of human disease. High spatial resolution PET instrumentation is therefore necessary due to the reduced dimensions of the organs. Inorganic scintillators are employed in most of the diagnostic imaging devices. The ultimate performance of the PET scanner is tightly bound to the scintillation properties of the crystals. In the last years there has been an effort to develop new scintillating materials characterized by high light output, high detection efficiency and fast decay time. The most studied systems are mainly Ce3+-doped crystals such as LSO:Ce, YAP:Ce, LuAP:Ce, and recently also mixed Lux(RE3+)1-xAlO3:Ce crystals. These crystals are very attractive for medical application because of their high density (with th...

  14. Maine's Employability Skills Program

    Science.gov (United States)

    McMahon, John M.; Wolffe, Karen E.; Wolfe, Judy; Brooker, Carrie

    2013-01-01

    This Practice Report describes the development and implementation of the "Maine Employability Skills Program," a model employment program developed by the Maine Division for the Blind and Visually Impaired (DBVI). The program was designed to support the efforts of the chronically unemployed or underemployed. These consumers were either…

  15. Maternal Employment: 1979.

    Science.gov (United States)

    Hoffman, Lois Wladis

    1979-01-01

    Maternal employment is a part of modern family life, a response to changes such as smaller families and more efficient household management. Not only does maternal employment meet parents' needs, but it is a pattern better suited for socializing the child for the adult role s/he will occupy. (Author/GC)

  16. Dimensions of Adolescent Employment.

    Science.gov (United States)

    Mael, Fred A.; Morath, Ray A.; McLellan, Jeffrey A.

    1997-01-01

    Examines positive and negative correlates of adolescent work as a function of work dimensions. Results indicate that concurrent costs and benefits of adolescent employment may depend on dimensions of work as well as adolescent characteristics. Adolescent employment was generally related to subsequent work motivation and nonacademic performance.…

  17. Does Supported Employment Work?

    Science.gov (United States)

    Morgan McInnes, Melayne; Ozturk, Orgul Demet; McDermott, Suzanne; Mann, Joshua R.

    2010-01-01

    Providing employment-related services, including supported employment through job coaches, has been a priority in federal policy since the enactment of the Developmental Disabilities Assistance and Bill of Rights Act in 1984. We take advantage of a unique panel data set of all clients served by the South Carolina Department of Disabilities and…

  18. Use of Terrestrial Laser Scanner for Rigid Airport Pavement Management.

    Science.gov (United States)

    Barbarella, Maurizio; D'Amico, Fabrizio; De Blasiis, Maria Rosaria; Di Benedetto, Alessandro; Fiani, Margherita

    2017-12-26

    The evaluation of the structural efficiency of airport infrastructures is a complex task. Faulting is one of the most important indicators of rigid pavement performance. The aim of our study is to provide a new method for faulting detection and computation on jointed concrete pavements. Nowadays, the assessment of faulting is performed with the use of laborious and time-consuming measurements that strongly hinder aircraft traffic. We proposed a field procedure for Terrestrial Laser Scanner data acquisition and a computation flow chart in order to identify and quantify the fault size at each joint of apron slabs. The total point cloud has been used to compute the least square plane fitting those points. The best-fit plane for each slab has been computed too. The attitude of each slab plane with respect to both the adjacent ones and the apron reference plane has been determined by the normal vectors to the surfaces. Faulting has been evaluated as the difference in elevation between the slab planes along chosen sections. For a more accurate evaluation of the faulting value, we have then considered a few strips of data covering rectangular areas of different sizes across the joints. The accuracy of the estimated quantities has been computed too.

  19. Application of 3D Laser Scanner to Forensic Engineering.

    Science.gov (United States)

    Park, Chan-Seong; Jeon, Hong-Pil; Choi, Kwang-Soo; Kim, Jin-Pyo; Park, Nam-Kyu

    2018-05-01

    In the case of building collapses and overturned structures, a three-dimensional (3D) collapse or overturn model is required to reconstruct the accident. As construction sites become increasingly complex and large, 3D laser scanning is sometimes the best tool to accurately document and store the site conditions. This case report presents one case of a structure collapse and one case of an overturned crane reconstructed by a 3D laser scanner. In the case of structural collapse of a prefabricated shoring system, a 3D model reconstructed all the members successfully, a task that is nearly impossible using a scale such as a tape measure. The reconstructed prefabricated shoring system was verified through a structural analysis through comparison with the construction drawings to investigate faults in construction. In the case of the overturned crane, the jib angle and other major dimensions were successfully acquired through 3D laser scanning and used to estimate the working radius. As a result, the propriety of the working radius with the given lifting load was successfully determined. © 2017 American Academy of Forensic Sciences.

  20. Use of Terrestrial Laser Scanner for Rigid Airport Pavement Management

    Directory of Open Access Journals (Sweden)

    Maurizio Barbarella

    2017-12-01

    Full Text Available The evaluation of the structural efficiency of airport infrastructures is a complex task. Faulting is one of the most important indicators of rigid pavement performance. The aim of our study is to provide a new method for faulting detection and computation on jointed concrete pavements. Nowadays, the assessment of faulting is performed with the use of laborious and time-consuming measurements that strongly hinder aircraft traffic. We proposed a field procedure for Terrestrial Laser Scanner data acquisition and a computation flow chart in order to identify and quantify the fault size at each joint of apron slabs. The total point cloud has been used to compute the least square plane fitting those points. The best-fit plane for each slab has been computed too. The attitude of each slab plane with respect to both the adjacent ones and the apron reference plane has been determined by the normal vectors to the surfaces. Faulting has been evaluated as the difference in elevation between the slab planes along chosen sections. For a more accurate evaluation of the faulting value, we have then considered a few strips of data covering rectangular areas of different sizes across the joints. The accuracy of the estimated quantities has been computed too.

  1. Design of a portable CAT scanner for utility pole inspection

    International Nuclear Information System (INIS)

    Miller, W.H.

    1986-01-01

    Work is under way at the University of Missouri, Columbia (UMC) to design, build, and test a portable computerized axial tomography (CAT) device for the nondestructive, field imaging of wooden utility poles. CAT is a well-established medical technology that has recently been applied to a number of industrial applications. Wooden utility poles are prone to rot and decay at ground level; current techniques to assess this loss of strength are relatively primitive, i.e., tapping the pole (hitting the pole with a hammer) or boring into the pole for samples and then testing inside the bore hole with an electrical pulse device. The accuracy in identifying poles needing replacement using these techniques is ∼ 70%. Since the cost of replacing a pole ranges from hundreds to thousands of dollars, an accurate, nondestructive method is needed. CAT can accurately image a wooden utility pole (since the size, density, and atomic elements of a pole are similar to the human head to torso), as was confirmed by imaging poles using the UMC nuclear engineering EMI-1010 medical scanner. Detailed images have been produced showing the ring structure of the wood and voids due to rot or decay. Images approaching this quality have also been produced on living trees using semiportable systems by other researchers

  2. Performance evaluation and calibration of the neuro-pet scanner

    International Nuclear Information System (INIS)

    Sank, V.J.; Brooks, R.A.; Cascio, H.E.; Di Chiro, G.; Friauf, W.S.; Leighton, S.B.

    1983-01-01

    The Neuro-PET is a circular ring seven-slice positron emission tomograph designed for imaging human heads and small animals. The scanner uses 512 bismuth germanate detectors 8.25 mm wide packed tightly together in four layers to achieve high spatial resolution (6-7 mm FWHM) without the use of beam blockers. Because of the small 38 cm ring diameter, the sensitivity is also very high: 70,000 c/s per true slice with medium energy threshold (375 keV) for a 20 cm diameter phantom containing 1 μCi/cc of positron-emitting activity, according to a preliminary measurement. There are three switch-selectable thresholds, and the sensitivity will be higher in the low threshold setting. The Neuro-PET is calibrated with a round or elliptical phantom that approximates a patient's head; this method eliminates the effects of scatter and self-attenuation to first order. Further software corrections for these artifacts are made in the reconstruction program, which reduce the measured scatter to zero, as determined with a 5 cm cold spot. With a 1 cm cold spot, the apparent activity at the center of the cold spot is 18% of the surrounding activity, which is clearly a consequence of the limits of spatial resolution, rather than scatter. The Neuro-PET has been in clinical operation since June 1982, and approximately 30 patients have been scanned to date

  3. 2D MEMS scanner integrating a position feedback

    Directory of Open Access Journals (Sweden)

    Lani Sebastien

    2015-01-01

    Full Text Available An integrated position sensor for a dual-axis electromagnetic tilting mirror is presented. This tilting mirror is composed of a silicon based mirror directly assembled on a silicon membrane supported by flexible beams. The position sensors are constituted by 4 Wheatstone bridges of piezoresistors which are fabricated by doping locally the flexible beams. A permanent magnet is attached to the membrane and the scanner is mounted above planar coils deposited on a ceramic substrate to achieve electromagnetic actuation. The performances of the piezoresistive sensors are evaluated by measuring the output signal of the piezoresistors as a function of the tilt of the mirror and the temperature. White light interferometry was performed for all measurement to measure the exact tilt angle. The minimum detectable angle with such sensors was 30μrad (around 13bits in the range of the minimum resolution of the interferometer. The tilt reproducibility was 0.0186%, obtained by measuring the tilt after repeated actuations with a coil current of 50mA during 30 min and the stability over time was 0.05% in 1h without actuation. The maximum measured tilt angle was 6° (mechanical limited by nonlinearity of the MEMS system.

  4. Rail Track Detection and Modelling in Mobile Laser Scanner Data

    Directory of Open Access Journals (Sweden)

    S. Oude Elberink

    2013-10-01

    Full Text Available We present a method for detecting and modelling rails in mobile laser scanner data. The detection is based on the properties of the rail tracks and contact wires such as relative height, linearity and relative position with respect to other objects. Points classified as rail track are used in a 3D modelling algorithm. The modelling is done by first fitting a parametric model of a rail piece to the points along each track, and estimating the position and orientation parameters of each piece model. For each position and orientation parameter a smooth low-order Fourier curve is interpolated. Using all interpolated parameters a mesh model of the rail is reconstructed. The method is explained using two areas from a dataset acquired by a LYNX mobile mapping system in a mountainous area. Residuals between railway laser points and 3D models are in the range of 2 cm. It is concluded that a curve fitting algorithm is essential to reliably and accurately model the rail tracks by using the knowledge that railways are following a continuous and smooth path.

  5. Wire Scanner Beam Profile Measurements for the LANSCE Facility

    Energy Technology Data Exchange (ETDEWEB)

    Gilpatrick, John D. [Los Alamos National Laboratory; Gruchalla, Michael E. [Los Alamos National Laboratory; Martinez, Derwin [Los Alamos National Laboratory; Pillai, Chandra [Los Alamos National Laboratory; Rodriguez Esparza, Sergio [Los Alamos National Laboratory; Sedillo, James Daniel [Los Alamos National Laboratory; Smith, Brian G. [Los Alamos National Laboratory

    2012-05-15

    The Los Alamos Neutron Science Center (LANSCE) is replacing beam profile measurement systems, commonly known as Wire Scanners (WS). Using the principal of secondary electron emission, the WS measurement system moves a wire or fiber across an impinging particle beam, sampling a projected transverse-beam distribution. Because existing WS actuators and electronic components are either no longer manufactured or home-built with antiquated parts, a new WS beam profile measurement is being designed, fabricated, and tested. The goals for these new WS's include using off-the-shelf components while eliminating antiquated components, providing quick operation while allowing for easy maintainability, and tolerating external radioactivation. The WS measurement system consists of beam line actuators, a cable plant, an electronics processor chassis, and software located both in the electronics chassis (National Instruments LabVIEW) and in the Central Control Room (EPICS-based client software). This WS measurement system will measure Hand H{sup +} LANSCE-facility beams and will also measure less common beams. This paper describes these WS measurement systems.

  6. Wire Scanner Beam Profile Measurements for the LANSCE Facility

    International Nuclear Information System (INIS)

    Gilpatrick, John D.; Gruchalla, Michael E.; Martinez, Derwin; Pillai, Chandra; Rodriguez Esparza, Sergio; Sedillo, James Daniel; Smith, Brian G.

    2012-01-01

    The Los Alamos Neutron Science Center (LANSCE) is replacing beam profile measurement systems, commonly known as Wire Scanners (WS). Using the principal of secondary electron emission, the WS measurement system moves a wire or fiber across an impinging particle beam, sampling a projected transverse-beam distribution. Because existing WS actuators and electronic components are either no longer manufactured or home-built with antiquated parts, a new WS beam profile measurement is being designed, fabricated, and tested. The goals for these new WS's include using off-the-shelf components while eliminating antiquated components, providing quick operation while allowing for easy maintainability, and tolerating external radioactivation. The WS measurement system consists of beam line actuators, a cable plant, an electronics processor chassis, and software located both in the electronics chassis (National Instruments LabVIEW) and in the Central Control Room (EPICS-based client software). This WS measurement system will measure Hand H + LANSCE-facility beams and will also measure less common beams. This paper describes these WS measurement systems.

  7. Methods for registration laser scanner point clouds in forest stands

    International Nuclear Information System (INIS)

    Bienert, A.; Pech, K.; Maas, H.-G.

    2011-01-01

    Laser scanning is a fast and efficient 3-D measurement technique to capture surface points describing the geometry of a complex object in an accurate and reliable way. Besides airborne laser scanning, terrestrial laser scanning finds growing interest for forestry applications. These two different recording platforms show large differences in resolution, recording area and scan viewing direction. Using both datasets for a combined point cloud analysis may yield advantages because of their largely complementary information. In this paper, methods will be presented to automatically register airborne and terrestrial laser scanner point clouds of a forest stand. In a first step, tree detection is performed in both datasets in an automatic manner. In a second step, corresponding tree positions are determined using RANSAC. Finally, the geometric transformation is performed, divided in a coarse and fine registration. After a coarse registration, the fine registration is done in an iterative manner (ICP) using the point clouds itself. The methods are tested and validated with a dataset of a forest stand. The presented registration results provide accuracies which fulfill the forestry requirements [de

  8. A radioisotope scanner for use in developing countries

    International Nuclear Information System (INIS)

    Crawley, J.C.W.; Cronquist, A.G.; Veall, N.; Ajdukiewicz, A.B.; Bassett, N.

    1981-01-01

    A scanner was designed for use at the Medical Research Council Laboratories in The Gambia, in a research project on the epidemiology and treatment of hepatoma. The detector consists of a 40-cm long by 5-cm diameter sodium iodide crystal assembly with one photo-multiplier at each end moving sideways over the area to be scanned. A fork lift truck forms the main frame of the instrument with a yoke carrying the detector in place of the forks. This assembly can be raised and lowered by a manually operated hydraulic system and rotated to scan from above, below or beside the patient. The relatively thick detector can be used with indium-113 as well as technetium-99m. A small cabinet mounted on the fork lift truck houses the electronic circuits and carries the polaroid camera for recording the scans. Rechargeable batteries floating across a DC power supply buffer the instrument against the wide fluctuations in mains voltage and frequent power cuts that occur at Fajara. The instrument was designed and constructed at Harrow before shipment by sea to The Gambia, where it has been in use for about 18 months. (author)

  9. Inland wetland change detection using aircraft MSS [multispectral scanner] data

    International Nuclear Information System (INIS)

    Jensen, J.R.; Ramsey, E.W.; Mackey, H.E. Jr.; Sharitz, R.R.; Christensen, E.J.

    1986-01-01

    Nontidal wetlands in a portion of the Savannah River swamp forest affected by reactor cooling water discharges were mapped using March 31, 1981 and April 29, 1985 high-resolution aircraft multispectral scanner (MSS) data. Due to the inherent distortion in the aircraft MSS data and the complex spectral characteristics of the wetland vegetation, it was necessary to implement multiple techniques in the registration and classification of the MSS imagery of the Pen Branch Delta on each date. In particular, it was necessary to use a piecewise-linear registration process over relatively small regions to perform image-to-image registration. When performing unsupervised classification, an iterative ''cluster busting'' technique was used, which simplified the cluster labeling process. These procedures allowed important wetland vegetation categories to be identified on each date. The multiple-date classification maps were then evaluated using a post-classification comparison technique yielding change classes that were of value in determining the extent of inland wetland change in this region

  10. Clinical applications of the imatron fast CT scanner

    International Nuclear Information System (INIS)

    Stanford, W.

    1986-01-01

    Utilizing three imaging modes, Cine CT has proven satisfactory in the assessment of left ventricular mass and function including ejection fractions and abnormalities of wall motion. It is helpful in documenting pericardial constrictions, as well as in assessing intracavitary tumors and thrombi. In the lungs, it is used to document AV fistulae and to evaluate the vascularity of mediastinal masses and to exclude invasion or major thoracic vessels. It can be used, as in the conventional scanner, for needle directed lung and chest well biopsies. It is frequently used in a airway studies to differentiate fixed from physiologic constrictions and to assess tracheomalacia and bronchopulmonary dysplasias. It can be used to plan radiation ports in the treatment of breast carcinoma. In the abdomen, successful applications include its use in the assessment of renal blood flow and the evaluation of cavernous hemangiomas of the liver as well as in screening of possible aortic aneurysms. In orthopedics, Cine CT is used to evaluate patellofermoral tracking in subluxations of the patella and used to evaluate subluxations and dislocations of the radio-ulnar joint. Cine CT by virtue of its speed and satisfactory spatial resolution is a significant imaging modality for evaluating the beating heart. Other applications include the evaluation of aortic aneurysms and dissections, para-aortic mass lesions, airway obstructions and patellar tracking and forearm subluxations

  11. The usefulness of the combined PET-CT scanner

    International Nuclear Information System (INIS)

    Yoshikawa, Kyosan

    2003-01-01

    Recently, combined PET-CT scanners that simultaneously reveal both anatomical and metabolic images within the body have been developed. The Siemens Biograph was the first PET-CT used in Japan and was installed at National Institute of Radiological Sciences (NIRS) at the end of March 2002. The Biograph system integrates Siemens PET (HR+) and spiral CT (SOMATOM Emotion Duo) technologies with a multimodality computer platform. The CT data obtained with PET-CT is also used for attenuation corrections of the PET images. The advantages of PET-CT for clinical use are much shorter study time for each patient, easy and precise alignment of the patient's lesion within the PET field of view, an increase in PET image quality due to the CT attenuation correction system which gives a higher spatial resolution and produces much less noise in the attenuation correction data, and an improvement in diagnostic accuracy provided by both functional and anatomic imaging. The Japanese government has not yet approved the marketing of PET-CT. We are continuing to investigate its usefulness. We expect that PET-CT will be a major diagnostic tool for oncology imaging in the near future. (authors)

  12. Improving scanner wafer alignment performance by target optimization

    Science.gov (United States)

    Leray, Philippe; Jehoul, Christiane; Socha, Robert; Menchtchikov, Boris; Raghunathan, Sudhar; Kent, Eric; Schoonewelle, Hielke; Tinnemans, Patrick; Tuffy, Paul; Belen, Jun; Wise, Rich

    2016-03-01

    In the process nodes of 10nm and below, the patterning complexity along with the processing and materials required has resulted in a need to optimize alignment targets in order to achieve the required precision, accuracy and throughput performance. Recent industry publications on the metrology target optimization process have shown a move from the expensive and time consuming empirical methodologies, towards a faster computational approach. ASML's Design for Control (D4C) application, which is currently used to optimize YieldStar diffraction based overlay (DBO) metrology targets, has been extended to support the optimization of scanner wafer alignment targets. This allows the necessary process information and design methodology, used for DBO target designs, to be leveraged for the optimization of alignment targets. In this paper, we show how we applied this computational approach to wafer alignment target design. We verify the correlation between predictions and measurements for the key alignment performance metrics and finally show the potential alignment and overlay performance improvements that an optimized alignment target could achieve.

  13. Radiation safety concerns and diagnostic reference levels for computed tomography scanners in Tamil Nadu

    International Nuclear Information System (INIS)

    Livingstone, Roshan S.; Dinakaran, Paul M.

    2011-01-01

    Radiation safety in computed tomography (CT) scanners is of concern due its widespread use in the field of radiological imaging. This study intends to evaluate radiation doses imparted to patients undergoing thorax, abdomen and pelvic CT examinations and formulate regional diagnostic reference levels (DRL) in Tamil Nadu, South India. In-site CT dose measurement was performed in 127 CT scanners in Tamil Nadu for a period of 2 years as a part of the Atomic Energy Regulatory Board (AERB)-funded project. Out of the 127 CT scanners,13 were conventional; 53 single-slice helical scanners (SSHS); 44 multislice CT (MSCT) scanners; and 17 refurbished scanners. CT dose index (CTDI) was measured using a 32-cm polymethyl methacrylate (PMMA)-body phantom in each CT scanner. Dose length product (DLP) for different anatomical regions was generated using CTDI values. The regional DRLs for thorax, abdomen and pelvis examinations were 557, 521 and 294 mGy cm, respectively. The mean effective dose was estimated using the DLP values and was found to be 8.04, 6.69 and 4.79 mSv for thorax, abdomen and pelvic CT examinations, respectively. The establishment of DRLs in this study is the first step towards optimization of CT doses in the Indian context. (author)

  14. Basic study of entire whole-body PET scanners based on the OpenPET geometry

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Eiji, E-mail: rush@nirs.go.j [National Institute of Radiological Sciences, 4-9-1 Inage-ku, Chiba 263-8555 (Japan); Yamaya, Taiga; Nishikido, Fumihiko; Inadama, Naoko; Murayama, Hideo [National Institute of Radiological Sciences, 4-9-1 Inage-ku, Chiba 263-8555 (Japan)

    2010-09-21

    A conventional PET scanner has a 15-25 cm axial field-of-view (FOV) and images a whole body using about six bed positions. An OpenPET geometry can extend the axial FOV with a limited number of detectors. The entire whole-body PET scanner must be able to process a large amount of data effectively. In this work, we study feasibility of the fully 3D entire whole-body PET scanner using the GATE simulation. The OpenPET has 12 block detector rings with the ring diameter of 840 mm and each block detector ring consists of 48 depth-of-interaction (DOI) detectors. The OpenPET has the axial length of 895.95 mm with five parts of 58.95 mm open gaps. The OpenPET has higher single data loss than a conventional PET scanner at grouping circuits. NECR of the OpenPET decreases by single data loss. But single data loss is mitigated by separating the axially arranged detector into two parts. Also, multiple coincidences are found to be important for the entire whole-body PET scanner. The entire whole-body PET scanner with the OpenPET geometry promises to provide a large axial FOV with the open space and to have sufficient performance values. But single data loss at the grouping circuits and multiple coincidences are limited to the peak noise equivalent count rate (NECR) for the entire whole-body PET scanner.

  15. Comparison of two intraoral scanners based on three-dimensional surface analysis

    Directory of Open Access Journals (Sweden)

    Kyung-Min Lee

    2018-02-01

    Full Text Available Abstract Background This in vivo study evaluated the difference of two well-known intraoral scanners used in dentistry, namely iTero (Align Technology and TRIOS (3Shape. Methods Thirty-two participants underwent intraoral scans with TRIOS and iTero scanners, as well as conventional alginate impressions. The scans obtained with the two intraoral scanners were compared with each other and were also compared with the corresponding model scans by means of three-dimensional surface analysis. The average differences between the two intraoral scans on the surfaces were evaluated by color-mapping. The average differences in the three-dimensional direction between each intraoral scans and its corresponding model scan were calculated at all points on the surfaces. Results The average differences between the two intraoral scanners were 0.057 mm at the maxilla and 0.069 mm at the mandible. Color histograms showed that local deviations between the two scanners occurred in the posterior area. As for difference in the three-dimensional direction, there was no statistically significant difference between two scanners. Conclusions Although there were some deviations in visible inspection, there was no statistical significance between the two intraoral scanners.

  16. Entrepreneurship and Employment Stability

    DEFF Research Database (Denmark)

    Failla, Virgilio; Melillo, Francesca; Reichstein, Toke

    2017-01-01

    This paper challenges the conventional belief that entrepreneurship is an unstable career path. Using longitudinal matched employer–employee data from Denmark, the analysis reveals that a transition to entrepreneurship decreases individual's employment turnover tendency. Three explanations...

  17. Veteran Services - Welcome Employers

    Science.gov (United States)

    Assistance Crosswalk websites Transition GPS National Career Readiness Certificate Post Traumatic Stress Credits (PDF) Fidelity Bonding Program National Career Readiness (PDF) Veteran Recruitment State/Federal veteran recruitment process Military Veteran Employment Guide Veterans Hiring Toolkit Other Information

  18. Duplication of complete dentures using general-purpose handheld optical scanner and 3-dimensional printer: Introduction and clinical considerations.

    Science.gov (United States)

    Kurahashi, Kosuke; Matsuda, Takashi; Goto, Takaharu; Ishida, Yuichi; Ito, Teruaki; Ichikawa, Tetsuo

    2017-01-01

    To introduce a new clinical procedure for fabricating duplicates of complete dentures by bite pressure impression using digital technology, and to discuss its clinical significance. The denture is placed on a rotary table and the 3-dimensional form of the denture is digitized using a general-purpose handheld optical scanner. The duplicate denture is made of polylactic acid by a 3-dimensional printer using the 3-dimensional data. This procedure has the advantages of wasting less material, employing less human power, decreasing treatment time at the chair side, lowering the rates of contamination, and being readily fabricated at the time of the treatment visit. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  19. Development of x-ray computed tomographic scanner for iron and steel

    International Nuclear Information System (INIS)

    Taguchi, Isamu; Nakamura, Shigeo.

    1985-01-01

    X-ray computed tomography is extensively used in medicine, but has rarely been applied to non-medical purposes. Steel specimens pose particularly difficult problems-very poor transmission of X-rays and the need for high resolving capability. There has thus been no effective tomographic method of examining steel specimens. Due to the growing need for non-destructive, non-contact methods for observing and analyzing the internal conditions of steel microscopically, however, we have developed an X-ray Computed Tomographic Scanner for Steel (CTS) system, specifically for examination of steel specimens. Its major specifications and functions are as follows. Type: the second-generation CT, 8-channels, Scanning method: 6 0 revolution, 30-times traversing, Slice width: 0.5 mm, Resolving capability: 0.25 x 0.25 mm, X-ray source: 420 kV, 3 mA, X-ray detector: BGO scintillator, Standard specimen shape: 50 mm dia., 100 mm high, Measuring time: 10.5 min. Porosity of a stainless steel (SUS 304) bloom was examined three-dimensionally by the CTS system. Corrosion procedure of a steel slab was also examined. (author)

  20. Employers meet employees

    OpenAIRE

    Scheuer, Christian

    2009-01-01

    "Leaping into the future of labor economics: the research potential of linking employer and employee data" is the title of a paper by Daniel S Hammermesh published in Labour Economics in 1999. I quote it here, since it captures much of my motivation for the work included in this thesis. Considering applied micro econometrics and labor economics my main elds of interest, the development of linked employer-employee data that took place in Denmark around the time of the new mille...

  1. Deficiency of employability capacity

    Directory of Open Access Journals (Sweden)

    Pelse I.

    2012-10-01

    Full Text Available Young unemployed people have comprised one of the significantly largest groups of the unemployed people in Latvia in recent years. One of the reasons why young people have difficulty integrating into the labour market is the “expectation gap” that exists in the relations between employers and the new generation of workers. Employers focus on capacity-building for employability such individual factors as strength, patience, self-discipline, self-reliance, self-motivation, etc., which having a nature of habit and are developed in a long-term work socialization process, which begins even before the formal education and will continue throughout the life cycle. However, when the socialization is lost, these habits are depreciated faster than they can be restored. Currently a new generation is entering the labour market, which is missing the succession of work socialization. Factors, such as rising unemployment and poverty in the background over the past twenty years in Latvia have created a very unfavourable employability background of “personal circumstances” and “external factors”, which seriously have impaired formation of the skills and attitudes in a real work environment. The study reveals another paradox – the paradox of poverty. Common sense would want to argue that poverty can be overcome by the job. However, the real state of affairs shows that unfavourable coincidence of the individual, personal circumstances and external factors leads to deficit of employability capacity and possibility of marked social and employment deprivation.

  2. Employment of security personnel

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    If a company or institution hires personnel of a security service company to protect its premises, this kind of employment does not mean the company carries on temporary employment business. Within the purview of section 99, sub-section 1 of the BetrVG (Works Constitution Act), the security service personnel is not 'employed' in the proper sense even if the security tasks fulfilled by them are done at other times by regular employees of the company or institution. The court decision also decided that the Works Council need not give consent to employment of foreign security personnel. The court decision was taken for settlement of court proceedings commenced by Institute of Plasma Physics in Garching. In his comments, W. Hunold accedes to the court's decision and discusses the underlying reasons of this decision and of a previous ruling in the same matter by putting emphasis on the difference between a contract for services and a contract for work, and a contract for temporary employment. The author also discusses the basic features of an employment contract. (orig./HP) [de

  3. Reducing Employment Insecurity

    Directory of Open Access Journals (Sweden)

    Florence Lebert

    2016-10-01

    Full Text Available The perception of job insecurity is known to be a stressful condition for employees. Less is known about employment insecurity and the ways employees and their families deal with it. This study investigates whether participation in further training is a strategy that employees adopt to reduce perceived employment insecurity. As participation in further training is often costly and time-consuming, we assume that the family context is of importance for the decision to take part in further training. To take account of possible self-selection, we apply a propensity score matching procedure on longitudinal data from the Swiss Household Panel (2004-2013. Three main findings can be emphasized: first, participation in further training is not a strategy adopted particularly by employees who perceive high employment insecurity as they are less likely to train than their secure counterparts. Second, even though further training is not a strategy that is actively adopted, employees who train subsequently report lower levels of perceived employment insecurity. Third, the family context indeed influences the likelihood to train: partnered employees are more likely to train and preschool-aged children act as a constraint on women’s but enhance men’s participation in further training. Yet, in the context of high perceived employment insecurity, children generally reduce their parents’ likelihood to train as the parents may turn to other strategies that reduce perceived employment insecurity.

  4. Employment of Near Full-Length Ribosome Gene TA-Cloning and Primer-Blast to Detect Multiple Species in a Natural Complex Microbial Community Using Species-Specific Primers Designed with Their Genome Sequences.

    Science.gov (United States)

    Zhang, Huimin; He, Hongkui; Yu, Xiujuan; Xu, Zhaohui; Zhang, Zhizhou

    2016-11-01

    It remains an unsolved problem to quantify a natural microbial community by rapidly and conveniently measuring multiple species with functional significance. Most widely used high throughput next-generation sequencing methods can only generate information mainly for genus-level taxonomic identification and quantification, and detection of multiple species in a complex microbial community is still heavily dependent on approaches based on near full-length ribosome RNA gene or genome sequence information. In this study, we used near full-length rRNA gene library sequencing plus Primer-Blast to design species-specific primers based on whole microbial genome sequences. The primers were intended to be specific at the species level within relevant microbial communities, i.e., a defined genomics background. The primers were tested with samples collected from the Daqu (also called fermentation starters) and pit mud of a traditional Chinese liquor production plant. Sixteen pairs of primers were found to be suitable for identification of individual species. Among them, seven pairs were chosen to measure the abundance of microbial species through quantitative PCR. The combination of near full-length ribosome RNA gene library sequencing and Primer-Blast may represent a broadly useful protocol to quantify multiple species in complex microbial population samples with species-specific primers.

  5. Computer-aided diagnosis of pneumoconiosis abnormalities extracted from chest radiographs scanned with a CCD scanner

    International Nuclear Information System (INIS)

    Abe, Koji; Minami, Masahide; Nakamura, Munehiro

    2011-01-01

    This paper presents a computer-aided diagnosis for pneumoconiosis radiographs obtained with a common charge-coupled devices (CCD) scanner. Since the current computer-aided diagnosis systems of pneumoconiosis are not practical for medical doctors due to high costs of usage for a special scanner, we propose a novel system which measures abnormalities of pneumoconiosis from lung images obtained with a common CCD scanner. Experimental results of discriminations between normal and abnormal cases for 56 right-lung images including 6 standard pneumoconiosis images have shown that the proposed abnormalities are well extracted according to the standards of pneumoconiosis categories. (author)

  6. Joint Calibration of 3d Laser Scanner and Digital Camera Based on Dlt Algorithm

    Science.gov (United States)

    Gao, X.; Li, M.; Xing, L.; Liu, Y.

    2018-04-01

    Design a calibration target that can be scanned by 3D laser scanner while shot by digital camera, achieving point cloud and photos of a same target. A method to joint calibrate 3D laser scanner and digital camera based on Direct Linear Transformation algorithm was proposed. This method adds a distortion model of digital camera to traditional DLT algorithm, after repeating iteration, it can solve the inner and external position element of the camera as well as the joint calibration of 3D laser scanner and digital camera. It comes to prove that this method is reliable.

  7. Mechanical optimisation of a high-precision fast wire scanner at CERN

    CERN Document Server

    Samuelsson, Sebastian; Veness, Raymond

    Wire scanners are instruments used to measure the transverse beam prole in particle accelerators by passing a thin wire through the particle beam. To avoid the issues of vacuum leakage through the bellows and wire failure related to current designs of wire scanners, a new concept for a wire scanner has been developed at CERN. This design has all moving parts inside the beam vacuum and has a nominal wire scanning speed of 20 m/s. The demands on the design associated with this together with the high precision requirements create a need for\

  8. Who gets afraid in the MRI-scanner? Neurogenetics of state-anxiety changes during an fMRI experiment.

    Science.gov (United States)

    Mutschler, Isabella; Wieckhorst, Birgit; Meyer, Andrea H; Schweizer, Tina; Klarhöfer, Markus; Wilhelm, Frank H; Seifritz, Erich; Ball, Tonio

    2014-11-07

    Experiments using functional magnetic resonance imaging (fMRI) play a fundamental role in affective neuroscience. When placed in an MR scanner, some volunteers feel safe and relaxed in this situation, while others experience uneasiness and fear. Little is known about the basis and consequences of such inter-individually different responses to the general experimental fMRI setting. In this study emotional stimuli were presented during fMRI and subjects' state-anxiety was assessed at the onset and end of the experiment while they were within the scanner. We show that Val/Val but neither Met/Met nor Val/Met carriers of the catechol-O-methyltransferase (COMT) Val(158)Met polymorphism-a prime candidate for anxiety vulnerability-became significantly more anxious during the fMRI experiment (N=97 females: 24 Val/Val, 51 Val/Met, and 22 Met/Met). Met carriers demonstrated brain responses with increased stability over time in the right parietal cortex and significantly better cognitive performances likely mediated by lower levels of anxiety. Val/Val, Val/Met and Met/Met did not significantly differ in state-anxiety at the beginning of the experiment. The exposure of a control group (N=56 females) to the same experiment outside the scanner did not cause a significant increase in state-anxiety, suggesting that the increase we observe in the fMRI experiment may be specific to the fMRI setting. Our findings reveal that genetics may play an important role in shaping inter-individual different emotional, cognitive and neuronal responses during fMRI experiments. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  9. Poster - 01: LabPET II Pixelated APD-Based PET Scanner for High-Resolution Preclinical Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lecomte, Roger; Arpin, Louis; Beaudoin, Jean-François; Bergeron, Mélanie; Bouchard, Jonathan; Bouziri, Haithem; Cadorette, Jules; Gaudin, Émilie; Jürgensen, Nadia; Koua, Konin Calliste; Trépanier, Pierre-Yves Lauzier; Leroux, Jean-Daniel; Loignon-Houle, Francis; Njejimana, Larissa; Paillé, Maxime; Paulin, Caroline; Pepin, Catherine; Pratte, Jean-François; Samson, Arnaud; Thibaudeau, Christian [Université de Sherbrooke, Université de Sherbrooke, CIMS/CRCHUS, Université de Sherbrooke, Université de Sherbrooke, Université de Sherbrooke, CIMS/CRCHUS, Université de Sherbrooke, Université de Sherbrooke, 3IT, Université de Sherbrooke, Novalgo Inc., Université de Sherbrooke, Université de Sherbrooke, CIMS/CRCHUS, 3IT, Université de Sherbrooke, Université de Sherbrooke, Université de Sherbrooke, Université de Sherbrooke, 3IT, Université de Sherbrooke (Canada); and others

    2016-08-15

    Purpose: LabPET II is a new generation APD-based PET scanner designed to achieve sub-mm spatial resolution using truly pixelated detectors and highly integrated parallel front-end processing electronics. Methods: The basic element uses a 4×8 array of 1.12×1.12 mm{sup 2} Lu{sub 1.9}Y{sub 0.1}SiO{sub 5}:Ce (LYSO) scintillator pixels with one-to-one coupling to a 4×8 pixelated monolithic APD array mounted on a ceramic carrier. Four detector arrays are mounted on a daughter board carrying two flip-chip, 64-channel, mixed-signal, application-specific integrated circuits (ASIC) on the backside interfacing to two detector arrays each. Fully parallel signal processing was implemented in silico by encoding time and energy information using a dual-threshold Time-over-Threshold (ToT) scheme. The self-contained 128-channel detector module was designed as a generic component for ultra-high resolution PET imaging of small to medium-size animals. Results: Energy and timing performance were optimized by carefully setting ToT thresholds to minimize the noise/slope ratio. ToT spectra clearly show resolved 511 keV photopeak and Compton edge with ToT resolution well below 10%. After correction for nonlinear ToT response, energy resolution is typically 24±2% FWHM. Coincidence time resolution between opposing 128-channel modules is below 4 ns FWHM. Initial imaging results demonstrate that 0.8 mm hot spots of a Derenzo phantom can be resolved. Conclusion: A new generation PET scanner featuring truly pixelated detectors was developed and shown to achieve a spatial resolution approaching the physical limit of PET. Future plans are to integrate a small-bore dedicated mouse version of the scanner within a PET/CT platform.

  10. Evaluation of patient dose using a virtual CT scanner: Applications to 4DCT simulation and Kilovoltage cone-beam imaging

    International Nuclear Information System (INIS)

    DeMarco, J J; Agazaryan, N; McNitt-Gray, M F; Cagnon, C H; Angel, E; Zankl, M

    2008-01-01

    This work evaluates the effects of patient size on radiation dose from simulation imaging studies such as four-dimensional computed tomography (4DCT) and kilovoltage cone-beam computed tomography (kV-CBCT). 4DCT studies are scans that include temporal information, frequently incorporating highly over-sampled imaging series necessary for retrospective sorting as a function of respiratory phase. This type of imaging study can result in a significant dose increase to the patient due to the slower table speed as compared with a conventional axial or helical scan protocol. Kilovoltage cone-beam imaging is a relatively new imaging technique that requires an on-board kilovoltage x-ray tube and a flat-panel detector. Instead of porting individual reference fields, the kV tube and flat-panel detector are rotated about the patient producing a cone-beam CT data set (kV-CBCT). To perform these investigations, we used Monte Carlo simulation methods with detailed models of adult patients and virtual source models of multidetector computed tomography (MDCT) scanners. The GSF family of three-dimensional, voxelized patient models, were implemented as input files using the Monte Carlo code MCNPX. The adult patient models represent a range of patient sizes and have all radiosensitive organs previously identified and segmented. Simulated 4DCT scans of each voxelized patient model were performed using a multi-detector CT source model that includes scanner specific spectra, bow-tie filtration, and helical source path. Standard MCNPX tally functions were applied to each model to estimate absolute organ dose based upon an air-kerma normalization measurement for nominal scanner operating parameters

  11. MR-guided percutaneous biopsy of solitary pulmonary lesions using a 1.0-T open high-field MRI scanner with respiratory gating

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ming; Huang, Jie; Xu, Yujun; He, Xiangmeng; Lue, Yubo; Liu, Qiang; Li, Chengli [Department of Interventional MRI, Shandong Medical Imaging Research Institute affiliated to Shandong University, Shandong Key Laboratory of Advanced Medical Imaging Technologies and Applications, Jinan, Shandong (China); Li, Lei [Qingdao Central Hospital, Department of Interventional Radiology, Qingdao, Shandong (China); Blanco Sequeiros, Roberto [Turku University Hospital, The South Western Finland Imaging Centre, Turku (Finland)

    2017-04-15

    To prospectively evaluate the feasibility, safety and accuracy of MR-guided percutaneous biopsy of solitary pulmonary lesions using a 1.0-T open MR scanner with respiratory gating. Sixty-five patients with 65 solitary pulmonary lesions underwent MR-guided percutaneous coaxial cutting needle biopsy using a 1.0-T open MR scanner with respiratory gating. Lesions were divided into two groups according to maximum lesion diameters: ≤2.0 cm (n = 31) and >2.0 cm (n = 34). The final diagnosis was established in surgery and subsequent histology. Diagnostic accuracy, sensitivity and specificity were compared between the groups using Fisher's exact test. Accuracy, sensitivity and specificity of MRI-guided percutaneous pulmonary biopsy in diagnosing malignancy were 96.9 %, 96.4 % and 100 %, respectively. Accuracy, sensitivity and specificity were 96.8 %, 96.3 % and 100 % for lesions 2.0 cm or smaller and 97.1 %, 96.4 % and 100 %, respectively, for lesions larger than 2.0 cm. There was no significant difference between the two groups (P > 0.05). Biopsy-induced complications encountered were pneumothorax in 12.3 % (8/65) and haemoptysis in 4.6 % (3/65). There were no serious complications. MRI-guided percutaneous biopsy using a 1.0-T open MR scanner with respiratory gating is an accurate and safe diagnostic technique in evaluation of pulmonary lesions. (orig.)

  12. SU-G-206-07: Dual-Energy CT Inter- and Intra-Scanner Variability Within One Make and Model

    International Nuclear Information System (INIS)

    Jacobsen, M; Wood, C; Cody, D

    2016-01-01

    Purpose: It can be logistically quite difficult to scan patients on the same exact device for their repeat visits in multi-scanner facilities. The reliability between dual-energy CT scanners’ quantitative results is not known, nor is their individual repeatability. Therefore, we evaluated inter- and intra-scanner variability with respect to several key clinical quantitative metrics specific to dual-energy CT. Methods: Eleven identical GE HD-750 CT scanners in a busy clinical environment were used to perform dual-energy (DE) CT scans of a large elliptical quality control (QC) phantom (Gammex, Inc.; Middleton, WI) which contains many standard insert materials. The DE-QC phantom was scanned bi-weekly during 2016; 3 to 4 scans were obtained from each scanner (a total of 35 data sets were used for analysis). Iodine accuracy for the 2mg/ml, 5mg/ml and 15mg/ml rods (from the Iodine(Water) image set) and soft tissue HU (40 HU based on NIST constants) from the 50keV data set were used to assess inter- and intra-scanner variability (standard deviation). Results: Intra-scanner variability average for 2mg/ml Iodine was 0.10 mg/ml (range 0.05–0.15 mg/ml), for 5mg/ml Iodine was 0.12 mg/ml (range 0.07–0.16 mg/ml), for 15 mg/ml Iodine was 0.25 mg/ml (range 0.16–0.37 mg/ml), and for the soft tissue inserts was 2.1 HU (range 1.8–2.6 HU). Inter-scanner variability average for 2mg/ml Iodine was 0.16 mg/ml (range 0.11–0.19 mg/ml), for 5mg/ml Iodine was 0.18 mg/ml (range 0.11–0.22 mg/ml), for 15 mg/ml Iodine was 0.35 mg/ml (range 0.23–0.44 mg/ml), and for the soft tissue inserts was 3.8 HU (range 3.1–4.5 HU). Conclusion: Intra-scanner variability for the iodine and soft tissue inserts averaged 3.1% and 5.2% respectively, and inter-scanner variability for these regions analyzed averaged 5.0% and 9.5%, respectively. Future work will include determination of smallest measurable change and acceptable limits for DE-CT scanner variability over longer time intervals. This

  13. Accuracy of complete-arch model using an intraoral video scanner: An in vitro study.

    Science.gov (United States)

    Jeong, Il-Do; Lee, Jae-Jun; Jeon, Jin-Hun; Kim, Ji-Hwan; Kim, Hae-Young; Kim, Woong-Chul

    2016-06-01

    Information on the accuracy of intraoral video scanners for long-span areas is limited. The purpose of this in vitro study was to evaluate and compare the trueness and precision of an intraoral video scanner, an intraoral still image scanner, and a blue-light scanner for the production of digital impressions. Reference scan data were obtained by scanning a complete-arch model. An identical model was scanned 8 times using an intraoral video scanner (CEREC Omnicam; Sirona) and an intraoral still image scanner (CEREC Bluecam; Sirona), and stone casts made from conventional impressions of the same model were scanned 8 times with a blue-light scanner as a control (Identica Blue; Medit). Accuracy consists of trueness (the extent to which the scan data differ from the reference scan) and precision (the similarity of the data from multiple scans). To evaluate precision, 8 scans were superimposed using 3-dimensional analysis software; the reference scan data were then superimposed to determine the trueness. Differences were analyzed using 1-way ANOVA and post hoc Tukey HSD tests (α=.05). Trueness in the video scanner group was not significantly different from that in the control group. However, the video scanner group showed significantly lower values than those of the still image scanner group for all variables (P<.05), except in tolerance range. The root mean square, standard deviations, and mean negative precision values for the video scanner group were significantly higher than those for the other groups (P<.05). Digital impressions obtained by the intraoral video scanner showed better accuracy for long-span areas than those captured by the still image scanner. However, the video scanner was less accurate than the laboratory scanner. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  14. The Employed Neurosurgeon: Essential Lessons.

    Science.gov (United States)

    Benzil, Deborah L; Zusman, Edie E

    2017-04-01

    Neurosurgeons are highly specialized surgeons whose pride is mastery of the complexity of form and function that is the nervous system and then knowing when and how these require surgical intervention. Following years of arduous postgraduate education, neurosurgeons enter the world of practice that is not only daunting in its intricacies of regulations, mandates, and unknown business practices, but also changing at a meteoric pace. Overwhelmingly, graduating residents and fellows are choosing to practice as employed physicians, a trend that is new in its magnitude and also changed because of the rapid evolution of large health systems. Case studies of challenges other employed surgical specialists have faced can provide critical and important education for any neurosurgeon in this arena. As with the lessons of all case studies, the teachings are remarkably universal, but how those lessons apply to an individual's specific situation will require personalized adaptation. Copyright © 2016 by the Congress of Neurological Surgeons.

  15. Towards the Experimental Assessment of the DQE in SPECT Scanners

    Science.gov (United States)

    Fountos, G. P.; Michail, C. M.

    2017-11-01

    The purpose of this work was to introduce the Detective Quantum Efficiency (DQE) in single photon emission computed tomography (SPECT) systems using a flood source. A Tc-99m-based flood source (Eγ = 140 keV) consisting of a radiopharmaceutical solution of dithiothreitol (DTT, 10-3 M)/Tc-99m(III)-DMSA, 40 mCi/40 ml bound to the grains of an Agfa MammoRay HDR Medical X-ray film) was prepared in laboratory. The source was placed between two PMMA blocks and images were obtained by using the brain tomographic acquisition protocol (DatScan-brain). The Modulation Transfer Function (MTF) was evaluated using the Iterative 2D algorithm. All imaging experiments were performed in a Siemens e-Cam gamma camera. The Normalized Noise Power spectra (NNPS) were obtained from the sagittal views of the source. The higher MTF values were obtained for the Flash Iterative 2D with 24 iterations and 20 subsets. The noise levels of the SPECT reconstructed images, in terms of the NNPS, were found to increase as the number of iterations increase. The behavior of the DQE was influenced by both MTF and NNPS. As the number of iterations was increased, higher MTF values were obtained, however with a parallel, increase of magnitude in image noise, as depicted from the NNPS results. DQE values, which were influenced by both MTF and NNPS, were found higher when the number of iterations results in resolution saturation. The method presented here is novel and easy to implement, requiring materials commonly found in clinical practice and can be useful in the quality control of SPECT scanners.

  16. Status of computed tomography dosimetry for wide cone beam scanners

    International Nuclear Information System (INIS)

    2011-01-01

    International standardization in dosimetry is essential for the successful exploitation of radiation technology. To provide such standardization in diagnostic radiology, the IAEA published Code of Practice entitled Dosimetry in Diagnostic Radiology: An International Code of Practice (IAEA Technical Reports Series No. 457; 2007), which recommends procedures for calibration and dosimetric measurement both in standards dosimetry laboratories, especially Secondary Standards Dosimetry Laboratories (SSDLs), and in clinical centres for radiology, as found in most hospitals. These standards address the main dosimetric methodologies needed in clinical diagnostic radiology, with the calibration of associated dosimetric equipment, including the measurement methodologies for computed tomography (CT). For some time now there has been a growing awareness that radiation dose originating from medical diagnostic procedures in radiology, is contributing an increasing proportion to the total population dose, with a large component coming from CT examinations. This is accompanied by rapid developments in CT technology, including the use of increasingly wide X ray scanning beams, which are presenting problems in dosimetry that currently cannot be adequately addressed by existing standards. This situation has received attention from a number of professional bodies, and institutions have proposed and are investigating new and adapted dosimetric models in order to find robust solutions to these problems that are critically affecting clinical application of CT dosimetry. In view of these concerns, and as a response to a recommendation from a coordinated research project that reviewed the implementation of IAEA Technical Reports Series No. 457, a meeting was held to review current dosimetric methodologies and to determine if a practical solution for dosimetry for wide X ray beam CT scanners was currently available. The meeting rapidly formed the view that there was an interim solution that

  17. Socio-economics on computed tomography (CT) scanner

    International Nuclear Information System (INIS)

    Niki, Ryu

    1983-01-01

    It was in 1975, only eight years ago, that a CT scanner was first introduced into Japan, which demonstrated enormous power in the early diagnosis of cephalic disease. Since then, CT has spread rapidly in spite of the initial high price of 200 million yen, and has attained 2,120 sets as of December, 1982. The rate of CT propagation in Japan is 18.5 sets per one million persons, or No. 1 in the world. However, its socio-economic investigation has only been done fragmentarily in Japan. In this report, the CT is investigated in three aspects of medical facilities, medical instrument manufacturers, and the medical fee of nation. In Japan, the CT installation has largely increased by 20 times in five years from 1977 to 1981, and has widely spread not only to medium to small scale hospitals but also to general clinics. In this report, the CT is investigated for the number in various facilities and prefectures, and the comparison of the state of use in USA and Japan. Since 1979, the products of domestic manufacturers were at advantage over foreign products in Japan, and Hitachi and Toshiba have been predominant among them. The fee for CT in Japan is only 1/5 as compared with that in the U.S. Setting extremely low fee like this may get into the danger to induce excessive inspection. The significant popularization of CT in Japan is much concerned with the features of Japanese medical care system as well as the medical technological characteristics of the CT. (Wakatsuki, Y.)

  18. Implementing public employment policy

    DEFF Research Database (Denmark)

    Larsen, Flemming; Bredgaard, Thomas

    disciplining of the unemployed (work first) (cf.Bredgaard & Larsen, 2005; Sol & Westerweld, 2005). It is, however, remarkable that in the research field there seems to be a division of labour so that changes in public administration and changes in the substance of employment policies are dealt with separately......Like most other areas within welfare policy, the employment and social policy areas are undergoing far-reaching changes in many countries. Partly in the shape of new forms of governance inspired by New Public Management (NPM), partly through new policies oriented towards activation and stronger....... But there is an interesting question to investigate here: whether and if so how, NPM-inspired reforms are related to changes in employment policy towards a work-first approach? Are changes in public management systems created as deliberate policy changes, or do they bring about more indirect and unintended policy changes...

  19. An image scanner for real time analysis of spark chamber images

    International Nuclear Information System (INIS)

    Cesaroni, F.; Penso, G.; Locci, A.M.; Spano, M.A.

    1975-01-01

    The notes describes the semiautomatic scanning system at LNF for the analysis of spark chamber images. From the projection of the images on the scanner table, the trajectory in the real space is reconstructed

  20. Automatic Tree Data Removal Method for Topography Measurement Result Using Terrestrial Laser Scanner

    Science.gov (United States)

    Yokoyama, H.; Chikatsu, H.

    2017-02-01

    Recently, laser scanning has been receiving greater attention as a useful tool for real-time 3D data acquisition, and various applications such as city modelling, DTM generation and 3D modelling of cultural heritage sites have been proposed. And, former digital data processing were demanded in the past digital archive techniques for cultural heritage sites. However, robust filtering method for distinguishing on- and off-terrain points by terrestrial laser scanner still have many issues. In the past investigation, former digital data processing using air-bone laser scanner were reported. Though, efficient tree removal methods from terrain points for the cultural heritage are not considered. In this paper, authors describe a new robust filtering method for cultural heritage using terrestrial laser scanner with "the echo digital processing technology" as latest data processing techniques of terrestrial laser scanner.

  1. The design of the detector and collimators for a hybrid scanner

    International Nuclear Information System (INIS)

    Vauramo, E.; Virjo, A.

    1977-01-01

    The hybrid scanner is a scanning device in which a long crystal with two or more photomultiplier (PM) tubes acts as a gamma camera along the crystal axis; the device acts as a linear scanner in a direction perpendicular to the crystal axis. A detailed analysis of the intrinsic resolution and uniformity is given for a two-PM-tube hybrid scanner (with one PM tube at each end) and the expressions derived should help the designer to choose the best crystal system. Collimation theory is discussed for the general hybrid scanner. Expressions and graphs are given to help in the design of a collimator with the best balance between the conflicting requirements of resolution, sensitivity, depth independence and freedom from artifacts (collimator holes may be seen in the image at high energy). Examples of practical collimators are given for energies of 80 to 140, 364, 511, 662 and 840 keV. (author)

  2. Symptoms and Cognitive Effects of Exposure to Magnetic Stray Fields of MRI Scanners

    NARCIS (Netherlands)

    Vocht, Frank Gérard de

    2006-01-01

    People working routinely with magnetic resonance imaging (MRI) systems report a number of symptoms related to their presence in the inhomogeneous static magnetic fields (the stray field) surrounding these scanners. Experienced symptoms and neurobehavioral performance among engineers manufacturing

  3. The mechatronic design of a fast wire scanner in IHEP U-70 accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Baranov, V.T. [Institute for High Energy Physics in National Research Centre “Kurchatov Institute”, Protvino 142281 (Russian Federation); Makhov, S.S. [Microprivod Ltd., Moscow 111123 (Russian Federation); Savin, D.A.; Terekhov, V.I. [Institute for High Energy Physics in National Research Centre “Kurchatov Institute”, Protvino 142281 (Russian Federation)

    2016-10-11

    This paper presents the mechatronic design of a fast wire scanner based on a servomotor. The design of the wire scanner is motivated by the need to measure the transverse profile of the high power proton and carbon beams at the IHEP U-70 accelerator. This paper formulates the requirements to the fast wire scanner system for the high intensity proton beam at the U-70 accelerator. The results on the design of electro-mechanical device for the wire scanner with a wire traveling speed 10–20 m/s are presented. The solution consists in a brushless servomotor and standard motor control electronics. High radiation levels in the accelerator enclosure dictate the use of a resolver as the position feedback element.

  4. Improved quality of image got through whole-body CT scanner

    International Nuclear Information System (INIS)

    Asahina, Kiyotaka

    1980-01-01

    The quality of brain images taken with a whole-body CT scanner has so far been generally inferior in quality to those got through a CT scanner exclusively used for brains. In order to improve the whole-body CT scanner so as to get better brain image, its detection system has been made multichannel; the capacity of its X-ray tube, increased; and its software, innovated. As a result, the spatial resolution has been improved from 5.51 p/cm to 9.01 p/cm, the contrast resolution has been improved from 3.2 mm% to 1.5 mm%, with the noise maintained at 0.5%. In clinical examination, the image quality has been improved equally well for brains, abdomens and lungs. Especially high appreciation is given to the diagnosis information got through this new scanner. (author)

  5. A double-bent planar leaf flexure guide for a nano-scanner: experimental report

    International Nuclear Information System (INIS)

    Jeon, Jeong-Woo; Kim, Jong-Moon; Lee, Young-Hyoung; Lee, Dong-Yeon

    2014-01-01

    We describe an experimental study on the double-bent leaf flexure-guided nano-scanner introduced in a previous paper [J. Korean Phy. Soc. 57, 1581 (2010)]. The optimally-designed nanoscanner was fabricated. Its performances were verified using a finite element analysis (FEA). The nano-scanner is actuated by a voice coil motor. Its characteristics were measured with a laser interferometer. The first resonant frequency is calculated as 17.1 Hz. The performances of the nano-scanner, including sine tracking capability, a multi-step response, and range of travel check were evaluated using various experimental procedures. Test results reveal that the scanner traveled over a 4.0 mm range and had good nano-precision (4 nm).

  6. SLAC Scanner Processor: a FASTBUS module for data collection and processing

    International Nuclear Information System (INIS)

    Brafman, H.; Glanzman, T.; Lankford, A.J.; Olsen, J.; Paffrath, L.

    1984-10-01

    A new, general purpose, programmable FASTBUS module, the SLAC Scanner Processor (SSP), is introduced. Both hardware and software elements of SSP operation are discussed. The role of the SSP within the upgraded Mark II Detector at SLAC is described

  7. Employment certificates on HRT

    CERN Multimedia

    HR Department

    2008-01-01

    As part of the ongoing drive to simplify and streamline administrative procedures and processes, the IT and HR Departments have made employment certificates available on a self-service basis on the HRT application, in the main menu under "My self services". All members of the personnel can thus obtain a certificate of employment or association, in French or in English, for the present or past contractual period. The HR Department’s Records Office remains responsible for issuing any special certificates that might be required. IT-AIS (Administrative Information Services) HR-SPS (Services, Procedures & Social) Records Office – Tel. 73700

  8. Radiation protection - the employer

    International Nuclear Information System (INIS)

    Goldfinch, E.

    1983-01-01

    A brief report is given of a paper presented at the symposium on 'Radiation and the Worker - where do we go from here' in London 1983. The paper concerned the employers' viewpoint on the draft of the proposed Ionising Radiations Regulations in the Health and Safety Commission Consultative Document. It was concluded that there was already a very good standard of radiological protection in the UK and that any improvements could therefore only be fringe improvements, although the cost to the employer of introducing and implementing the new proposed Regulations was bound to be high. (U.K.)

  9. Effects of injected dose, BMI and scanner type on NECR and image noise in PET imaging

    International Nuclear Information System (INIS)

    Chang Tingting; Chang Guoping; Clark, John W Jr; Kohlmyer, Steve; Rohren, Eric; Mawlawi, Osama R

    2011-01-01

    Noise equivalent count rate (NECR) and image noise are two different but related metrics that have been used to predict and assess image quality, respectively. The aim of this study is to investigate, using patient studies, the relationships between injected dose (ID), body mass index (BMI) and scanner type on NECR and image noise measurements in PET imaging. Two groups of 90 patients each were imaged on a GE DSTE and a DRX PET/CT scanner, respectively. The patients in each group were divided into nine subgroups according to three BMI (20-24.9, 25-29.9, 30-45 kg m -2 ) and three ID (296-444, 444-555, 555-740 MBq) ranges, resulting in ten patients/subgroup. All PET data were acquired in 3D mode and reconstructed using the VuePoint HD (registered) fully 3D OSEM algorithm (2 iterations, 21(DRX) or 20 (DSTE) subsets). NECR and image noise measurements for bed positions covering the liver were calculated for each patient. NECR was calculated from the trues, randoms and scatter events recorded in the DICOM header of each patient study, while image noise was determined as the standard deviation of 50 non-neighboring voxels in the liver of each patient. A t-test compared the NECR and image noise for different scanners but with the same BMI and ID. An ANOVA test on the other hand was used to compare the results of patients with different BMI but the same ID and scanner type as well as different ID but the same BMI and scanner type. As expected the t-test showed a significant difference in NECR between the two scanners for all BMI and ID subgroups. However, contrary to what is expected no such findings were observed for image noise measurement. The ANOVA results showed a statistically significant difference in both NECR and image noise among the different BMI for each ID and scanner subgroup. However, there was no statistically significant difference in NECR and image noise across different ID for each BMI and scanner subgroup. Although the GE DRX PET/CT scanner has better

  10. Psychological Prices and Price Rigidity in Grocery Retailing: Analysis of German Scanner Data

    OpenAIRE

    Herrmann, Roland; Moeser, Anke

    2005-01-01

    A substantial degree of price rigidity has been reported for branded foods in various studies with scanner data. One possible explanation for price rigidity is the existence of psychological pricing points. We analyze to which extent psychological pricing plays a role in grocery retailing and whether it contributes to price rigidity of branded foods in Germany. Psychological pricing defined here as just-below-the-round-figure-pricing is empirically analyzed with scanner data of weekly prices ...

  11. Two-Dimensional Metrology with Flatbed Scanners at Room and Liquid Nitrogen Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Grau Carles, A.; Grau Malonda, A. [CIEMAT. Madrid (Spain)

    2000-07-01

    We study the capability of the commercial flatbed scanner as a measuring instrument of two-coordinate sample both at room and liquid nitrogen temperatures. We describes simple procedure to calibrate the scanner, and the most adequate standard configuration to carry out the measurements. To illustrate the procedure, we measure the relative positions of the conductors in a cross-section of a superconducting magnet of CERN. (Author) 8 refs.

  12. Two-Dimensional Metrology with Flatbed Scanners at Room and Liquid Nitrogen Temperatures

    International Nuclear Information System (INIS)

    Grau Carles, A.; Grau Malonda, A.

    2000-01-01

    We study the capability of the commercial flatbed scanner as a measuring instrument of two-coordinate sample both at room and liquid nitrogen temperatures. We describes simple procedure to calibrate the scanner, and the most adequate standard configuration to carry out the measurements. To illustrate the procedure, we measure the relative positions of the conductors in a cross-section of a superconducting magnet of CERN. (Author) 8 refs

  13. A multispectral scanner survey of the Rocky Flats Environmental Technology Site and surrounding area, Golden, Colorado

    International Nuclear Information System (INIS)

    Brewster, S.B. Jr.; Brickey, D.W.; Ross, S.L.; Shines, J.E.

    1997-04-01

    Aerial multispectral scanner imagery was collected of the Rocky Flats Environmental Technology Site in Golden, Colorado, on June 3, 5, 6, and 7, 1994, using a Daedalus AADS1268 multispectral scanner and coincident aerial color and color infrared photography. Flight altitudes were 4,500 feet (1372 meters) above ground level to match prior 1989 survey data; 2,000 feet (609 meters) above ground level for sitewide vegetation mapping; and 1,000 feet (304 meters) above ground level for selected areas of special interest. A multispectral survey was initiated to improve the existing vegetation classification map, to identify seeps and springs, and to generate ARC/INFO Geographic Information System compatible coverages of the vegetation and wetlands for the entire site including the buffer zone. The multispectral scanner imagery and coincident aerial photography were analyzed for the detection, identification, and mapping of vegetation and wetlands. The multispectral scanner data were processed digitally while the color and color infrared photography were manually photo-interpreted to define vegetation and wetlands. Several standard image enhancement techniques were applied to the multispectral scanner data to assist image interpretation. A seep enhancement was applied and a color composite consisting of multispectral scanner channels 11, 7, and 5 (thermal infrared, mid-infrared, and red bands, respectively) proved most useful for detecting seeps, seep zones, and springs. The predawn thermal infrared data were also useful in identifying and locating seeps. The remote sensing data, mapped wetlands, and ancillary Geographic Information System compatible data sets were spatially analyzed for seeps

  14. Design and evaluation of a low thermal electromotive force guarded scanner for resistance measurements

    Science.gov (United States)

    Jarrett, Dean G.; Marshall, James A.; Marshall, Thomas A.; Dziuba, Ronald F.

    1999-06-01

    The design and testing of a low thermal electromotive force guarded scanner, developed to provide completely guarded switching when used with actively guarded resistance bridge networks, is described. The design provides a continuous guard circuit trace on the scanner circuit boards that surrounds the relay contacts and protects the measurement circuit from leakages to ground. Modification to the circuit boards and relays of the guarded scanner are explained. Several tests were developed to evaluate the guarding effectiveness, including isolating sections of the guard circuit to create a potential drop between the main and guard circuits. Calibration of standard resistors using the guarded scanner has shown relative differences less than 1×10-6, 30×10-6, and 150×10-6 for measurements made with and without the guarded scanner at nominal resistances of 1, 10, and 100 GΩ, respectively. The substitution method was used to significantly reduce the relative differences between channels to less than 0.5×10-6, 3×10-6, and 30×10-6 for nominal resistances of 1, 10, and 100 GΩ, respectively. Applications for the guarded scanner in automated direct current measurement systems are presented.

  15. Unsteady pressures on a blunt trailing edge measured with an embedded pressure scanner

    Science.gov (United States)

    Naughton, Jonathan; Nikoueeyan, Pourya; Hind, Michael; Strike, John; Dahland, Matz; Keeter, Steven

    2017-11-01

    Development of direct-mount pressure scanners can decrease the pneumatic tubing length required to connect the measurement ports to the scanner manifold resulting in improved dynamic range for unsteady pressure measurements. In this work, the performance of a direct-mount pressure scanner for time-resolved pressure measurement is demonstrated in a well-established flow; the pressure fluctuations near the base of flat plate is considered. The additive manufactured model is instrumented with a pressure scanner and flush-mounted high-speed pressure transducers. The configuration of the ports on the model allows for side-by-side comparison of the pressures measured via embedded pneumatic tubing routed to a pressure scanner with that measured by high-speed transducers. Prior to testing, the dynamic response of each embedded pressure port is dynamically calibrated via an in-situ calibration technique. Pressure data is then acquired for fixed angle-of-attack and different dynamic pitching conditions. The dynamic range of the measurements acquired via direct-mount scanner will be compared to those acquired by the high speed transducers for both static and dynamic pitching configurations. The uncertainties associated with Weiner deconvolution are also quantified for the measurements.

  16. A rural CT scanner: evaluating the effect on local health care

    International Nuclear Information System (INIS)

    Merkens, B.J.; Mowbray, R.D.; Creeden, L.; Engels, P.T.; Rothwell, D.M.; Chan, B.T.B.; Tu, K.

    2006-01-01

    The first small rural hospital in Ontario to propose a computed tomography (CT) scanner was in Walkerton, a town 160 km north of London. The Ontario Ministry of Health approved the proposal as a pilot project to evaluate the effect on local health care of a rural scanner. This evaluation study had 3 parts: a survey of physicians, a survey of patients, and an analysis of population CT scanning rates. The physicians in the area served by the scanner were asked about its impact on their care of their patients in a mailed questionnaire and in semistructured interviews. Scanner outpatients were given a questionnaire in which they rated the importance of its advantages. The analysis of scanning rates--the ratio of number of scans to estimated population--compared rates in the area with other Ontario rates before and after the scanner was introduced. The physicians reported that local CT allowed them to diagnose and treat patients sooner, closer to home, and with greater confidence. On average, 75% of the patients ranked faster and closer access as very important. Scanning rates in the area rose, although they did not match urban rates. The study confirms that the rural scanner changed the area's health care in significant ways and that it helped to narrow the gap between rural and urban service levels. We recommend that CT be expanded to other rural regions. (author)

  17. Inter-operator and inter-device agreement and reliability of the SEM Scanner.

    Science.gov (United States)

    Clendenin, Marta; Jaradeh, Kindah; Shamirian, Anasheh; Rhodes, Shannon L

    2015-02-01

    The SEM Scanner is a medical device designed for use by healthcare providers as part of pressure ulcer prevention programs. The objective of this study was to evaluate the inter-rater and inter-device agreement and reliability of the SEM Scanner. Thirty-one (31) volunteers free of pressure ulcers or broken skin at the sternum, sacrum, and heels were assessed with the SEM Scanner. Each of three operators utilized each of three devices to collect readings from four anatomical sites (sternum, sacrum, left and right heels) on each subject for a total of 108 readings per subject collected over approximately 30 min. For each combination of operator-device-anatomical site, three SEM readings were collected. Inter-operator and inter-device agreement and reliability were estimated. Over the course of this study, more than 3000 SEM Scanner readings were collected. Agreement between operators was good with mean differences ranging from -0.01 to 0.11. Inter-operator and inter-device reliability exceeded 0.80 at all anatomical sites assessed. The results of this study demonstrate the high reliability and good agreement of the SEM Scanner across different operators and different devices. Given the limitations of current methods to prevent and detect pressure ulcers, the SEM Scanner shows promise as an objective, reliable tool for assessing the presence or absence of pressure-induced tissue damage such as pressure ulcers. Copyright © 2015 Bruin Biometrics, LLC. Published by Elsevier Ltd.. All rights reserved.

  18. Active Damping of a Piezoelectric Tube Scanner using Self-Sensing Piezo Actuation

    Science.gov (United States)

    Kuiper, S.; Schitter, G.

    2010-01-01

    In most Atomic Force Microscopes (AFM), a piezoelectric tube scanner is used to position the sample underneath the measurement probe. Oscillations stemming from the weakly damped resonances of the tube scanner are a major source of image distortion, putting a limitation on the achievable imaging speed. This paper demonstrates active damping of these oscillations in multiple scanning axes without the need for additional position sensors. By connecting the tube scanner in a capacitive bridge circuit the scanner oscillations can be measured in both scanning axes, using the same piezo material as an actuator and sensor simultaneously. In order to compensate for circuit imbalance caused by hysteresis in the piezo element, an adaptive balancing circuit is used. The obtained measurement signal is used for feedback control, reducing the resonance peaks in both scanning axes by 18 dB and the cross-coupling at those frequencies by 30 dB. Experimental results demonstrate a significant reduction in scanner oscillations when applying the typical triangular scanning signals, as well as a strong reduction in coupling induced oscillations. Recorded AFM images show a considerable reduction in image distortion due to the proposed control method, enabling artifact free AFM imaging at a speed of 122 lines per second with a standard piezoelectric tube scanner. PMID:26412944

  19. Disability Employment 101

    Science.gov (United States)

    US Department of Education, 2007

    2007-01-01

    Business is about productivity and maintaining a competitive advantage. To do this, business needs qualified workers. Hiring people with disabilities adds value to a business and will attract new customers. Disability is not inability. Employers can make sound business decisions and gain a competitive advantage by using this guide to increase the…

  20. Discrimination in Employment

    Science.gov (United States)

    Abzug, Bella

    1975-01-01

    This testimony, before a public hearing of the New York City Commission on Human Rights in May 1974, expressly focuses on discrimination in employment, asserting that this has had the most direct effect on minorities and women in the country; while legal protections have grown stronger, they have not been used effectively. (Author/JM)

  1. Governing EU employment policy

    DEFF Research Database (Denmark)

    Sørensen, Eva; Triantafillou, Peter; Damgaard, Bodil

    2015-01-01

    In the European Union (EU), employment policy is a prerogative of the member states. Therefore the EU's ability to govern in this area depends on its capability to involve national governments and relevant stakeholders in a collaborative effort to formulate and implement shared policy objectives....... of collaboration, the implementation phase mainly consists in the less demanding forms of cooperation and coordination....

  2. Employment Relations in Denmark

    DEFF Research Database (Denmark)

    Madsen, Jørgen Steen; Due, Jesper Jørgen; Andersen, Søren Kaj

    2011-01-01

    Jørgen Steen Madsen, Jesper Due og Søren Kaj Andersen har skrevet et kapitel om udviklingen i dansk arbejdsmarkedsregulering til bogen International and Comparative Employment Relations, redigeret af Greg Bamber, Russell Lansbury og Nick Wailes. Bogen indeholder bidrag, der præsenterer og...

  3. Employment Challenges in Kenya

    African Journals Online (AJOL)

    Dr Kazungu

    of foreigners in rural trade, use of work permits to limit employment of expatriates, .... as social and trade union protection, job security, and wage negotiations to the worker. .... are Republic of Korea (1960–2001); Malaysia (1967–1997); Malta ...

  4. Transitional Employment Programs.

    Science.gov (United States)

    Dulle, Paul J.; And Others

    The paper examines the need and implementation of transitional employment programs for handicapped youth. Effects on the handicapped of future automation are considered along with the need for school-business cooperation to prepare for the future. The importance of initial success in any innovation is noted. A Chicago transitional employment…

  5. Policies for full employment

    DEFF Research Database (Denmark)

    de Koning, Jaap; Layard, Richard; Nickel, Stephen

    European unemployment is too high, and employment is too low. Over 7½ per cent of Europe's workforce is unemployed, and only two thirds of people aged 15-64 are in work. At the Lisbon summit two years ago the heads of government set the target that by 2010 the employment rate should rise from 64...... per cent to at least 70 per cent. And for older workers between 55 and 64 the employment rate should rise from 38 per cent to at least one half. These are ambitious targets. They will require two big changes: more people must seek work, and among those seeking work a higher proportion must get a job....... So we need higher participation, and (for full employment) we need a much lower unemployment rate. Can it be done? A mere glance at the experience of different European countries shows that it can. As Table 1 shows, four E.U. countries already exceed the overall target for 2010 (Britain, Denmark...

  6. Implementing the employability agenda

    DEFF Research Database (Denmark)

    Lee, Donna; Snaith, Holly Grace; Foster, Emma

    2014-01-01

    whether, and how, colleagues in politics and international relations (IR) had taken ownership of student employability at the level of the curriculum. In the article, the key findings of the research are summarised. There is also discussion of the (sometimes troubling) professional implications...

  7. Industrialisation, Exports and Employment.

    Science.gov (United States)

    Sabolo, Yves

    1980-01-01

    After reviewing trends in industrial production, exports, and employment in the Third World since 1960, the author discusses industrialization strategies based on the local processing of raw materials for export. Such processing has proved to be a major factor in job creation. (Author/SK)

  8. The Employment Mismatch

    Science.gov (United States)

    Fischer, Karin

    2013-01-01

    Employers value a four-year college degree, many of them more than ever. Yet half of those surveyed recently by "The Chronicle" and American Public Media's "Marketplace" said they had trouble finding recent graduates qualified to fill positions at their company or organization. Nearly a third gave colleges just fair to poor marks for producing…

  9. Effect of scanner acoustic background noise on strict resting-state fMRI.

    Science.gov (United States)

    Rondinoni, C; Amaro, E; Cendes, F; dos Santos, A C; Salmon, C E G

    2013-04-01

    Functional MRI (fMRI) resting-state experiments are aimed at identifying brain networks that support basal brain function. Although most investigators consider a 'resting-state' fMRI experiment with no specific external stimulation, subjects are unavoidably under heavy acoustic noise produced by the equipment. In the present study, we evaluated the influence of auditory input on the resting-state networks (RSNs). Twenty-two healthy subjects were scanned using two similar echo-planar imaging sequences in the same 3T MRI scanner: a default pulse sequence and a reduced "silent" pulse sequence. Experimental sessions consisted of two consecutive 7-min runs with noise conditions (default or silent) counterbalanced across subjects. A self-organizing group independent component analysis was applied to fMRI data in order to recognize the RSNs. The insula, left middle frontal gyrus and right precentral and left inferior parietal lobules showed significant differences in the voxel-wise comparison between RSNs depending on noise condition. In the presence of low-level noise, these areas Granger-cause oscillations in RSNs with cognitive implications (dorsal attention and entorhinal), while during high noise acquisition, these connectivities are reduced or inverted. Applying low noise MR acquisitions in research may allow the detection of subtle differences of the RSNs, with implications in experimental planning for resting-state studies, data analysis, and ergonomic factors.

  10. Image quality assesment using NEMA NU 4/2008 standards in small animal PET scanner

    International Nuclear Information System (INIS)

    Gontijo, Rodrigo M.G.; Ferreira, Andréa V.; Silva, Juliana B.; Mamede, Marcelo

    2017-01-01

    In Brazil, there are few micro PET in use and a quality control protocols standardization are needed to harmonize their use in the research field. Thus, the purpose of this study is to characterize the image quality performance of the micro PET scanner (Lab PET 4, GE healthcare Technologies, Waukesha, WI) using the NEMA NU 4/ 2008 standards and specific phantom. The NEMA image-quality (IQ) phantom consists of 3 different regions to analyze distinct characteristics: image noise (%SD), expressed as percentage SD in a uniform region (%SD), recovery coefficient (RC) and Spill-over (SOR) in air and water. The IQ phantom was filled with 18 F-FDG calibrated at the beginning of acquisition, placed in the center of the field-of-view (FOV) and measured with the typical whole body imaging protocol. The images were reconstructed with different reconstruction methods (FBP-2D; MLEM-3D and OSEM-3D); with and without high resolution (HR) when possible. The results were compared. The LabPET 4 system produces appropriate image and with performance according to the literature. The present study is an initial step to verify the NEMA NU 4/2008 use in the Brazilian scenario for further standardization. (author)

  11. Calibrating an optical scanner for quality assurance of large area radiation detectors

    Science.gov (United States)

    Karadzhinova, A.; Hildén, T.; Berdova, M.; Lauhakangas, R.; Heino, J.; Tuominen, E.; Franssila, S.; Hæggström, E.; Kassamakov, I.

    2014-11-01

    A gas electron multiplier (GEM) is a particle detector used in high-energy physics. Its main component is a thin copper-polymer-copper sandwich that carries Ø =70  ±  5 µm holes. Quality assurance (QA) is needed to guarantee both long operating life and reading fidelity of the GEM. Absence of layer defects and conformity of the holes to specifications is important. Both hole size and shape influence the detector’s gas multiplication factor and hence affect the collected data. For the scanner the required lateral measurement tolerance is ± 5 µm. We calibrated a high aspect ratio optical scanning system (OSS) to allow ensuring the quality of large GEM foils. For the calibration we microfabricated transfer standards, which were imaged with the OSS and which were compared to corresponding scanning electron microscopy (SEM) images. The calibration fulfilled the ISO/IEC 17025 and UKAS M3003 requirements: the calibration factor was 1.01  ±  0.01, determined at 95% confidence level across a 950  ×  950 mm2 area. The proposed large-scale scanning technique can potentially be valuable in other microfabricated products too.

  12. Image quality assesment using NEMA NU 4/2008 standards in small animal PET scanner

    Energy Technology Data Exchange (ETDEWEB)

    Gontijo, Rodrigo M.G.; Ferreira, Andréa V.; Silva, Juliana B.; Mamede, Marcelo, E-mail: rodrigo.gontijo@cdtn.br, E-mail: rodrigogadelhagontijo1@hotmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-07-01

    In Brazil, there are few micro PET in use and a quality control protocols standardization are needed to harmonize their use in the research field. Thus, the purpose of this study is to characterize the image quality performance of the micro PET scanner (Lab PET 4, GE healthcare Technologies, Waukesha, WI) using the NEMA NU 4/ 2008 standards and specific phantom. The NEMA image-quality (IQ) phantom consists of 3 different regions to analyze distinct characteristics: image noise (%SD), expressed as percentage SD in a uniform region (%SD), recovery coefficient (RC) and Spill-over (SOR) in air and water. The IQ phantom was filled with {sup 18}F-FDG calibrated at the beginning of acquisition, placed in the center of the field-of-view (FOV) and measured with the typical whole body imaging protocol. The images were reconstructed with different reconstruction methods (FBP-2D; MLEM-3D and OSEM-3D); with and without high resolution (HR) when possible. The results were compared. The LabPET 4 system produces appropriate image and with performance according to the literature. The present study is an initial step to verify the NEMA NU 4/2008 use in the Brazilian scenario for further standardization. (author)

  13. Framework for Automated GD&T Inspection Using 3D Scanner

    Science.gov (United States)

    Pathak, Vimal Kumar; Singh, Amit Kumar; Sivadasan, M.; Singh, N. K.

    2018-04-01

    Geometric Dimensioning and Tolerancing (GD&T) is a typical dialect that helps designers, production faculty and quality monitors to convey design specifications in an effective and efficient manner. GD&T has been practiced since the start of machine component assembly but without overly naming it. However, in recent times industries have started increasingly emphasizing on it. One prominent area where most of the industries struggle with is quality inspection. Complete inspection process is mostly human intensive. Also, the use of conventional gauges and templates for inspection purpose highly depends on skill of workers and quality inspectors. In industries, the concept of 3D scanning is not new but is used only for creating 3D drawings or modelling of physical parts. However, the potential of 3D scanning as a powerful inspection tool is hardly explored. This study is centred on designing a procedure for automated inspection using 3D scanner. Linear, geometric and dimensional inspection of the most popular test bar-stepped bar, as a simple example was also carried out as per the new framework. The new generation engineering industries would definitely welcome this automated inspection procedure being quick and reliable with reduced human intervention.

  14. Effect of scanner acoustic background noise on strict resting-state fMRI

    Directory of Open Access Journals (Sweden)

    C. Rondinoni

    2013-04-01

    Full Text Available Functional MRI (fMRI resting-state experiments are aimed at identifying brain networks that support basal brain function. Although most investigators consider a ‘resting-state' fMRI experiment with no specific external stimulation, subjects are unavoidably under heavy acoustic noise produced by the equipment. In the present study, we evaluated the influence of auditory input on the resting-state networks (RSNs. Twenty-two healthy subjects were scanned using two similar echo-planar imaging sequences in the same 3T MRI scanner: a default pulse sequence and a reduced “silent” pulse sequence. Experimental sessions consisted of two consecutive 7-min runs with noise conditions (default or silent counterbalanced across subjects. A self-organizing group independent component analysis was applied to fMRI data in order to recognize the RSNs. The insula, left middle frontal gyrus and right precentral and left inferior parietal lobules showed significant differences in the voxel-wise comparison between RSNs depending on noise condition. In the presence of low-level noise, these areas Granger-cause oscillations in RSNs with cognitive implications (dorsal attention and entorhinal, while during high noise acquisition, these connectivities are reduced or inverted. Applying low noise MR acquisitions in research may allow the detection of subtle differences of the RSNs, with implications in experimental planning for resting-state studies, data analysis, and ergonomic factors.

  15. Health complaints among nurses working near MRI scanners-A descriptive pilot study

    International Nuclear Information System (INIS)

    Wilen, Jonna; Vocht, Frank de

    2011-01-01

    A questionnaire-based descriptive pilot study was conducted among all nurses routinely working with MRI in the Northern part of Sweden to provide an indication of the self-reported prevalence of health complaints related to working with MRI systems. Fifty-nine nurses (88% response rate), with on average 8 (±6) years experience with MRI scanning procedures, returned the questionnaire. In total, 9 nurses (15%) reported regularly experiencing at least one of the health complaints (1-5% for specific health complaints) attributed to arise or be aggravated by their presence in the MRI scanning room. Stratification of the results indicated that reporting of adverse symptoms was not related to the level of occupational workload/stress. However, reporting of health complaints was related to the strength of the magnet(s) the nurses worked with, with 57% of symptoms reported by those nurses working with the strongest systems (both 1.5 and 3 T scanners in this population). Although this descriptive study did not include a control population and was based on self-reporting of health complaints, these data indicate that the prevalence of reported health complaints is not related to perceived work load or occupational stress, but does confirm data from other occupational sectors and indicates that the prevalence of adverse health complaints increases with the strength of the MRI system for nurses as well.

  16. POTENTIAL OF UAV-BASED LASER SCANNER AND MULTISPECTRAL CAMERA DATA IN BUILDING INSPECTION

    Directory of Open Access Journals (Sweden)

    D. Mader

    2016-06-01

    Full Text Available 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.

  17. Performance evaluation of a high resolution dedicated breast PET scanner

    Energy Technology Data Exchange (ETDEWEB)

    García Hernández, Trinitat, E-mail: mtrinitat@eresa.com; Vicedo González, Aurora; Brualla González, Luis; Granero Cabañero, Domingo [Department of Medical Physics, ERESA, Hospital General Universitario, Valencia 46014 (Spain); Ferrer Rebolleda, Jose; Sánchez Jurado, Raúl; Puig Cozar Santiago, Maria del [Department of Nuclear Medicine, ERESA, Hospital General Universitario, Valencia 46014 (Spain); Roselló Ferrando, Joan [Department of Medical Physics, ERESA, Hospital General Universitario, Valencia 46014 (Spain); Department of Physiology, University of Valencia, Valencia 46010 (Spain)

    2016-05-15

    Purpose: Early stage breast cancers may not be visible on a whole-body PET scan. To overcome whole-body PET limitations, several dedicated breast positron emission tomography (DbPET) systems have emerged nowadays aiming to improve spatial resolution. In this work the authors evaluate the performance of a high resolution dedicated breast PET scanner (Mammi-PET, Oncovision). Methods: Global status, uniformity, sensitivity, energy, and spatial resolution were measured. Spheres of different sizes (2.5, 4, 5, and 6 mm diameter) and various 18 fluorodeoxyglucose ({sup 18}F-FDG) activity concentrations were randomly inserted in a gelatine breast phantom developed at our institution. Several lesion-to-background ratios (LBR) were simulated, 5:1, 10:1, 20:1, 30:1, and 50:1. Images were reconstructed using different voxel sizes. The ability of experienced reporters to detect spheres was tested as a function of acquisition time, LBR, sphere size, and matrix reconstruction voxel size. For comparison, phantoms were scanned in the DbPET camera and in a whole body PET (WB-PET). Two patients who just underwent WB-PET/CT exams were imaged with the DbPET system and the images were compared. Results: The measured absolute peak sensitivity was 2.0%. The energy resolution was 24.0% ± 1%. The integral and differential uniformity were 10% and 6% in the total field of view (FOV) and 9% and 5% in the central FOV, respectively. The measured spatial resolution was 2.0, 1.9, and 1.7 mm in the radial, tangential, and axial directions. The system exhibited very good detectability for spheres ≥4 mm and LBR ≥10 with a sphere detection of 100% when acquisition time was set >3 min/bed. For LBR = 5 and acquisition time of 7 min the detectability was 100% for spheres of 6 mm and 75% for spheres of 5, 4, and 2.5 mm. Lesion WB-PET detectability was only comparable to the DbPET camera for lesion sizes ≥5 mm when acquisition time was >3 min and LBR > 10. Conclusions: The DbPET has a good

  18. Maximum likelihood positioning algorithm for high-resolution PET scanners

    International Nuclear Information System (INIS)

    Gross-Weege, Nicolas; Schug, David; Hallen, Patrick; Schulz, Volkmar

    2016-01-01

    Purpose: In high-resolution positron emission tomography (PET), lightsharing elements are incorporated into typical detector stacks to read out scintillator arrays in which one scintillator element (crystal) is smaller than the size of the readout channel. In order to identify the hit crystal by means of the measured light distribution, a positioning algorithm is required. One commonly applied positioning algorithm uses the center of gravity (COG) of the measured light distribution. The COG algorithm is limited in spatial resolution by noise and intercrystal Compton scatter. The purpose of this work is to develop a positioning algorithm which overcomes this limitation. Methods: The authors present a maximum likelihood (ML) algorithm which compares a set of expected light distributions given by probability density functions (PDFs) with the measured light distribution. Instead of modeling the PDFs by using an analytical model, the PDFs of the proposed ML algorithm are generated assuming a single-gamma-interaction model from measured data. The algorithm was evaluated with a hot-rod phantom measurement acquired with the preclinical HYPERION II D PET scanner. In order to assess the performance with respect to sensitivity, energy resolution, and image quality, the ML algorithm was compared to a COG algorithm which calculates the COG from a restricted set of channels. The authors studied the energy resolution of the ML and the COG algorithm regarding incomplete light distributions (missing channel information caused by detector dead time). Furthermore, the authors investigated the effects of using a filter based on the likelihood values on sensitivity, energy resolution, and image quality. Results: A sensitivity gain of up to 19% was demonstrated in comparison to the COG algorithm for the selected operation parameters. Energy resolution and image quality were on a similar level for both algorithms. Additionally, the authors demonstrated that the performance of the ML

  19. Performance evaluation of a high resolution dedicated breast PET scanner

    International Nuclear Information System (INIS)

    García Hernández, Trinitat; Vicedo González, Aurora; Brualla González, Luis; Granero Cabañero, Domingo; Ferrer Rebolleda, Jose; Sánchez Jurado, Raúl; Puig Cozar Santiago, Maria del; Roselló Ferrando, Joan

    2016-01-01

    Purpose: Early stage breast cancers may not be visible on a whole-body PET scan. To overcome whole-body PET limitations, several dedicated breast positron emission tomography (DbPET) systems have emerged nowadays aiming to improve spatial resolution. In this work the authors evaluate the performance of a high resolution dedicated breast PET scanner (Mammi-PET, Oncovision). Methods: Global status, uniformity, sensitivity, energy, and spatial resolution were measured. Spheres of different sizes (2.5, 4, 5, and 6 mm diameter) and various 18 fluorodeoxyglucose ("1"8F-FDG) activity concentrations were randomly inserted in a gelatine breast phantom developed at our institution. Several lesion-to-background ratios (LBR) were simulated, 5:1, 10:1, 20:1, 30:1, and 50:1. Images were reconstructed using different voxel sizes. The ability of experienced reporters to detect spheres was tested as a function of acquisition time, LBR, sphere size, and matrix reconstruction voxel size. For comparison, phantoms were scanned in the DbPET camera and in a whole body PET (WB-PET). Two patients who just underwent WB-PET/CT exams were imaged with the DbPET system and the images were compared. Results: The measured absolute peak sensitivity was 2.0%. The energy resolution was 24.0% ± 1%. The integral and differential uniformity were 10% and 6% in the total field of view (FOV) and 9% and 5% in the central FOV, respectively. The measured spatial resolution was 2.0, 1.9, and 1.7 mm in the radial, tangential, and axial directions. The system exhibited very good detectability for spheres ≥4 mm and LBR ≥10 with a sphere detection of 100% when acquisition time was set >3 min/bed. For LBR = 5 and acquisition time of 7 min the detectability was 100% for spheres of 6 mm and 75% for spheres of 5, 4, and 2.5 mm. Lesion WB-PET detectability was only comparable to the DbPET camera for lesion sizes ≥5 mm when acquisition time was >3 min and LBR > 10. Conclusions: The DbPET has a good performance

  20. Precarious Employment and Quality of Employment in Relation to Health and Well-being in Europe.

    Science.gov (United States)

    Julià, Mireia; Vanroelen, Christophe; Bosmans, Kim; Van Aerden, Karen; Benach, Joan

    2017-07-01

    This article presents an overview of the recent work on precarious employment and employment quality in relation to workers' health and well-being. More specifically, the article mainly reviews the work performed in the E.U. 7th Framework project, SOPHIE. First, we present our overarching conceptual framework. Then, we provide a compiled overview of the evidence on the sociodemographic and European cross-country distribution of employment quality and employment precariousness. Subsequently, we provide the current evidence regarding the relations with health and broader worker well-being indicators. A final section summarizes current insights on the pathways relating precarious employment and health and well-being. The article concludes with a plea for further data collection and research into the longitudinal effects of employment precariousness among emerging groups of workers. Based on the evidence compiled in this article, policymakers should be convinced of the harmful health and well-being effects of employment precariousness and (further) labor market flexibilization.