The design of the CMOS wireless bar code scanner applying optical system based on ZigBee

Science.gov (United States)

Chen, Yuelin; Peng, Jian

2008-03-01

The traditional bar code scanner is influenced by the length of data line, but the farthest distance of the wireless bar code scanner of wireless communication is generally between 30m and 100m on the market. By rebuilding the traditional CCD optical bar code scanner, a CMOS code scanner is designed based on the ZigBee to meet the demands of market. The scan system consists of the CMOS image sensor and embedded chip S3C2401X, when the two dimensional bar code is read, the results show the inaccurate and wrong code bar, resulted from image defile, disturber, reads image condition badness, signal interference, unstable system voltage. So we put forward the method which uses the matrix evaluation and Read-Solomon arithmetic to solve them. In order to construct the whole wireless optics of bar code system and to ensure its ability of transmitting bar code image signals digitally with long distances, ZigBee is used to transmit data to the base station, and this module is designed based on image acquisition system, and at last the wireless transmitting/receiving CC2430 module circuit linking chart is established. And by transplanting the embedded RTOS system LINUX to the MCU, an applying wireless CMOS optics bar code scanner and multi-task system is constructed. Finally, performance of communication is tested by evaluation software Smart RF. In broad space, every ZIGBEE node can realize 50m transmission with high reliability. When adding more ZigBee nodes, the transmission distance can be several thousands of meters long.

Low-complexity joint symbol synchronization and sampling frequency offset estimation scheme for optical IMDD OFDM systems.

Science.gov (United States)

Zhang, Zhen; Zhang, Qianwu; Chen, Jian; Li, Yingchun; Song, Yingxiong

2016-06-13

A low-complexity joint symbol synchronization and SFO estimation scheme for asynchronous optical IMDD OFDM systems based on only one training symbol is proposed. Numerical simulations and experimental demonstrations are also under taken to evaluate the performance of the mentioned scheme. The experimental results show that robust and precise symbol synchronization and the SFO estimation can be achieved simultaneously at received optical power as low as -20dBm in asynchronous OOFDM systems. SFO estimation accuracy in MSE can be lower than 1 × 10-11 under SFO range from -60ppm to 60ppm after 25km SSMF transmission. Optimal System performance can be maintained until cumulate number of employed frames for calculation is less than 50 under above-mentioned conditions. Meanwhile, the proposed joint scheme has a low level of operation complexity comparing with existing methods, when the symbol synchronization and SFO estimation are considered together. Above-mentioned results can give an important reference in practical system designs.

Recent developments with a prototype fan-beam optical CT scanner

Science.gov (United States)

Campbell, W. G.; Jirasek, A.; Wells, D.

2013-06-01

The latest design of a prototype fan-beam optical computed tomography scanner is presented. A new beam creation system consists of a 635 nm laser diode module with variable, DC voltage-controlled beam intensity. A change in scanner alignment allows for the elimination of ring artefacts caused by data corruption that is spaced symmetrically across the detector array. These artefacts, as well as a pair of streaking artefacts caused by flask seams, are removed in sinogram space. A flask registration technique has been developed that allows for accurate, reproducible dosimeter placement. Protocol investigations with gel dosimeters have indicated the importance of: i) proper cooling techniques during gel manufacture, and ii) scanning the dosimeter while it is at room temperature. Latest reconstructions of a normoxic polymer gel dosimeter are presented as an indicator of current system performance.

Recent developments with a prototype fan-beam optical CT scanner

International Nuclear Information System (INIS)

Campbell, W G; Jirasek, A; Wells, D

2013-01-01

The latest design of a prototype fan-beam optical computed tomography scanner is presented. A new beam creation system consists of a 635 nm laser diode module with variable, DC voltage-controlled beam intensity. A change in scanner alignment allows for the elimination of ring artefacts caused by data corruption that is spaced symmetrically across the detector array. These artefacts, as well as a pair of streaking artefacts caused by flask seams, are removed in sinogram space. A flask registration technique has been developed that allows for accurate, reproducible dosimeter placement. Protocol investigations with gel dosimeters have indicated the importance of: i) proper cooling techniques during gel manufacture, and ii) scanning the dosimeter while it is at room temperature. Latest reconstructions of a normoxic polymer gel dosimeter are presented as an indicator of current system performance.

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.

Wear Distribution Detection of Knee Joint Prostheses by Means of 3D Optical Scanners

Directory of Open Access Journals (Sweden)

Saverio Affatato

2017-03-01

Full Text Available The objective of this study was to examine total knee polyethylene inserts from in vitro simulation to evaluate and display—using a 3D optical scanner—wear patterns and wear rates of inserts exposed to wear by means of simulators. Various sets of tibial inserts have been reconstructed by using optical scanners. With this in mind, the wear behavior of fixed and mobile bearing polyethylene knee configurations was investigated using a knee wear joint simulator. After the completion of the wear test, the polyethylene menisci were analyzed by an innovative 3D optical scanners in order to evaluate the 3D wear distribution on the prosthesis surface. This study implemented a new procedure for evaluating polyethylene bearings of joint prostheses obtained after in vitro wear tests and the proposed new approach allowed quantification of the contact zone on the geometry of total knee prostheses. The results of the present study showed that mobile TKPs (total knee prosthesis have lower wear resistance with respect to fixed TKPs.

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

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.

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)

Portable optical fiber probe-based spectroscopic scanner for rapid cancer diagnosis: a new tool for intraoperative margin assessment.

Directory of Open Access Journals (Sweden)

Niyom Lue

Full Text Available There continues to be a significant clinical need for rapid and reliable intraoperative margin assessment during cancer surgery. Here we describe a portable, quantitative, optical fiber probe-based, spectroscopic tissue scanner designed for intraoperative diagnostic imaging of surgical margins, which we tested in a proof of concept study in human tissue for breast cancer diagnosis. The tissue scanner combines both diffuse reflectance spectroscopy (DRS and intrinsic fluorescence spectroscopy (IFS, and has hyperspectral imaging capability, acquiring full DRS and IFS spectra for each scanned image pixel. Modeling of the DRS and IFS spectra yields quantitative parameters that reflect the metabolic, biochemical and morphological state of tissue, which are translated into disease diagnosis. The tissue scanner has high spatial resolution (0.25 mm over a wide field of view (10 cm × 10 cm, and both high spectral resolution (2 nm and high spectral contrast, readily distinguishing tissues with widely varying optical properties (bone, skeletal muscle, fat and connective tissue. Tissue-simulating phantom experiments confirm that the tissue scanner can quantitatively measure spectral parameters, such as hemoglobin concentration, in a physiologically relevant range with a high degree of accuracy (<5% error. Finally, studies using human breast tissues showed that the tissue scanner can detect small foci of breast cancer in a background of normal breast tissue. This tissue scanner is simpler in design, images a larger field of view at higher resolution and provides a more physically meaningful tissue diagnosis than other spectroscopic imaging systems currently reported in literatures. We believe this spectroscopic tissue scanner can provide real-time, comprehensive diagnostic imaging of surgical margins in excised tissues, overcoming the sampling limitation in current histopathology margin assessment. As such it is a significant step in the development of a

IMAGE PROCESSING BASED OPTICAL CHARACTER RECOGNITION USING MATLAB

OpenAIRE

Jyoti Dalal*1 & Sumiran Daiya2

2018-01-01

Character recognition techniques associate a symbolic identity with the image of character. In a typical OCR systems input characters are digitized by an optical scanner. Each character is then located and segmented, and the resulting character image is fed into a pre-processor for noise reduction and normalization. Certain characteristics are the extracted from the character for classification. The feature extraction is critical and many different techniques exist, each having its strengths ...

Experimental demonstration of 30 Gb/s direct-detection optical OFDM transmission with blind symbol synchronisation using virtual subcarriers.

Science.gov (United States)

Bouziane, R; Milder, P A; Erkılınç, S; Galdino, L; Kilmurray, S; Thomsen, B C; Bayvel, P; Killey, R I

2014-02-24

The paper investigates the performance of a blind symbol synchronisation technique for optical OFDM systems based on virtual subcarriers. The test-bed includes a real-time 16-QAM OFDM transmitter operating at a net data rate of 30.65 Gb/s using a single OFDM band with a single FPGA-DAC subsystem and demonstrates transmission over 23.3 km SSMF with direct detection at a BER of 10(-3). By comparing the performance of the proposed synchronisation scheme with that of the Schmidl and Cox algorithm, it was found that the two approaches achieve similar performance for large numbers of averaging symbols, but the performance of the proposed scheme degrades as the number of averaging symbols is reduced. The proposed technique has lower complexity and bandwidth overhead as it does not rely on training sequences. Consequently, it is suitable for implementation in high speed optical OFDM transceivers.

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)

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.

New Challenges in Tribology: Wear Assessment Using 3D Optical Scanners.

Science.gov (United States)

Valigi, Maria Cristina; Logozzo, Silvia; Affatato, Saverio

2017-05-18

Wear is a significant mechanical and clinical problem. To acquire further knowledge on the tribological phenomena that involve freeform mechanical components or medical prostheses, wear tests are performed on biomedical and industrial materials in order to solve or reduce failures or malfunctions due to material loss. Scientific and technological advances in the field of optical scanning allow the application of innovative devices for wear measurements, leading to improvements that were unimaginable until a few years ago. It is therefore important to develop techniques, based on new instrumentations, for more accurate and reproducible measurements of wear. The aim of this work is to discuss the use of innovative 3D optical scanners and an experimental procedure to detect and evaluate wear, comparing this technique with other wear evaluation methods for industrial components and biomedical devices.

Comparison of calibration strategies for optical 3D scanners based on structured light projection using a new evaluation methodology

Science.gov (United States)

Bräuer-Burchardt, Christian; Ölsner, Sandy; Kühmstedt, Peter; Notni, Gunther

2017-06-01

In this paper a new evaluation strategy for optical 3D scanners based on structured light projection is introduced. It can be used for the characterization of the expected measurement accuracy. Compared to the procedure proposed in the VDI/VDE guidelines for optical 3D measurement systems based on area scanning it requires less effort and provides more impartiality. The methodology is suitable for the evaluation of sets of calibration parameters, which mainly determine the quality of the measurement result. It was applied to several calibrations of a mobile stereo camera based optical 3D scanner. The performed calibrations followed different strategies regarding calibration bodies and arrangement of the observed scene. The results obtained by the different calibration strategies are discussed and suggestions concerning future work on this area are given.

Performance improvement of 64-QAM coherent optical communication system by optimizing symbol decision boundary based on support vector machine

Science.gov (United States)

Chen, Wei; Zhang, Junfeng; Gao, Mingyi; Shen, Gangxiang

2018-03-01

High-order modulation signals are suited for high-capacity communication systems because of their high spectral efficiency, but they are more vulnerable to various impairments. For the signals that experience degradation, when symbol points overlap on the constellation diagram, the original linear decision boundary cannot be used to distinguish the classification of symbol. Therefore, it is advantageous to create an optimum symbol decision boundary for the degraded signals. In this work, we experimentally demonstrated the 64-quadrature-amplitude modulation (64-QAM) coherent optical communication system using support-vector machine (SVM) decision boundary algorithm to create the optimum symbol decision boundary for improving the system performance. We investigated the influence of various impairments on the 64-QAM coherent optical communication systems, such as the impairments caused by modulator nonlinearity, phase skew between in-phase (I) arm and quadrature-phase (Q) arm of the modulator, fiber Kerr nonlinearity and amplified spontaneous emission (ASE) noise. We measured the bit-error-ratio (BER) performance of 75-Gb/s 64-QAM signals in the back-to-back and 50-km transmission. By using SVM to optimize symbol decision boundary, the impairments caused by I/Q phase skew of the modulator, fiber Kerr nonlinearity and ASE noise are greatly mitigated.

Microscopy system of atomic force based on a digital optical reading unit and a buzzer-scanner

International Nuclear Information System (INIS)

Dabirian, R.; Loza M, D.; Wang, W. M.; Hwu, E. T.

2015-01-01

An astigmatic detection system (Ads) based on a compact disk/digital-versatile-disk (Cd-DVD) astigmatic optical pickup unit is presented. It can achieve a resolution better than 0.3 nm in detection of the vertical displacement and is able to detect the two-dimensional angular tilt of the object surface. Furthermore, a novel scanner design actuated by piezoelectric disk buzzers is presented. The scanner is composed of a quad-rod actuation structure and several piezoelectric disks. It can be driven directly with low-voltage and low-current sources, such as analogue outputs of a data acquisition card and enables a sufficient scanning range of up to μm. In addition, an economic, high-performance streamlined atomic force microscopy (AFM) was constructed, using the buzzer-scanner to move the sample relative to the probe, and using a Cd/DVD optical pickup unit to detect the mechanical resonance of a micro fabricated cantilever. The performance of the AFM is evaluated. The high sensitivity and high bandwidth of the detection system makes the equipment suitable for characterizing nano scale elements. An AFM using our detection system for detecting the deflection of micro fabricated cantilevers can resolve individual atomic steps on graphite surfaces. (Author)

Recent advances in dental optics - Part I: 3D intraoral scanners for restorative dentistry

Science.gov (United States)

Logozzo, Silvia; Zanetti, Elisabetta M.; Franceschini, Giordano; Kilpelä, Ari; Mäkynen, Anssi

2014-03-01

Intra-oral scanning technology is a very fast-growing field in dentistry since it responds to the need of an accurate three-dimensional mapping of the mouth, as required in a large number of procedures such as restorative dentistry and orthodontics. Nowadays, more than 10 intra-oral scanning devices for restorative dentistry have been developed all over the world even if only some of those devices are currently available on the market. All the existing intraoral scanners try to face with problems and disadvantages of traditional impression fabrication process and are based on different non-contact optical technologies and principles. The aim of this publication is to provide an extensive review of existing intraoral scanners for restorative dentistry evaluating their working principles, features and performances.

A fast dual wavelength laser beam fluid-less optical CT scanner for radiotherapy 3D gel dosimetry II: dosimetric performance

Science.gov (United States)

Ramm, Daniel

2018-02-01

New clinical radiotherapy dosimetry systems need comprehensive demonstration of measurement quality. Practicality and reliability are other important aspects for clinical dosimeters. In this work the performance of an optical CT scanner for true 3D dosimetry is assessed using a radiochromic gel dosimeter. The fluid-less scanner utilised dual lasers to avoid the necessity for pre-irradiation scans and give greater robustness of image quality, enhancing practicality. Calibration methods using both cuvettes and reconstructed volumes were developed. Dosimetric accuracy was similar for dual and single wavelength measurements, except that cuvette calibration reliability was reduced for dual wavelength without pre-irradiation scanning. Detailed performance parameters were specified for the dosimetry system indicating the suitability for clinical use. The most significant limitations of the system were due to the gel dosimeter rather than the optical CT scanner. Quality assurance guidelines were developed to maintain dosimetry system performance in routine use.

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.

Symbolic-computation study of the perturbed nonlinear Schrodinger model in inhomogeneous optical fibers

International Nuclear Information System (INIS)

Tian Bo; Gao Yitian

2005-01-01

A realistic, inhomogeneous fiber in the optical communication systems can be described by the perturbed nonlinear Schrodinger model (also named as the normalized nonlinear Schrodinger model with periodically varying coefficients, dispersion managed nonlinear Schrodinger model or nonlinear Schrodinger model with variable coefficients). Hereby, we extend to this model a direct method, perform symbolic computation and obtain two families of the exact, analytic bright-solitonic solutions, with or without the chirp respectively. The parameters addressed include the shape of the bright soliton, soliton amplitude, inverse width of the soliton, chirp, frequency, center of the soliton and center of the phase of the soliton. Of optical and physical interests, we discuss some previously-published special cases of our solutions. Those solutions could help the future studies on the optical communication systems. ms

Sci-Sat AM: Radiation Dosimetry and Practical Therapy Solutions - 08: A Low-Cost Optical Scanner and Gantry for use with 3D Printing of Radiation Therapy Accessories

Energy Technology Data Exchange (ETDEWEB)

Rickey, Daniel; Sasaki, David; Dubey, Arbind; Harris, Chad; Johnson, Kate; Egtberts, Andy; Koul, Rashmi [CancerCare Manitoba, CancerCare Manitoba, CancerCare Manitoba, CancerCare Manitoba, CancerCare Manitoba, CancerCare Manitoba, CancerCare Manitoba (Canada)

2016-08-15

Purpose: Three-dimensional printing has been implemented at our institution to create customized treatment accessories including shielding and bolus. In order to effectively use 3D printing, the topography of the patient must first be acquired. To this end, we have evaluated a low-cost structured-light 3D scanner in order to assess the clinical viability of this technology. Methods: For ease of use, the scanner (3D Systems, Sense 3D Scanner) was mounted in a simple gantry that guided its motion and maintained an optimum distance between the scanner and the object. To characterise the spatial accuracy of the scanner, we used a geometric phantom and an anthropomorphic head phantom. The geometric phantom was machined from plastic and had overall dimensions of 24 cm by 15 cm and included a hemispherical and a tetrahedron protrusion roughly the dimensions of an average forehead and nose respectively. Meshes acquired by the optical scanner were compared to meshes generated from high-resolution CT images. Results: Scans were acquired in under one minute. Most of the optical scans contained noticeable artefacts although in most instances these were considered minor. Using an algorithm that calculated distances between the two meshes, we found most of the optical scanner measurements agreed with those from CT to within about 1 mm for the geometric phantom and to within about 2 mm for the head phantom. Conclusion: In summary, we deemed this scanner to be clinically acceptable and it has been used to design treatment accessories for several skin cancer patients.

Sci-Sat AM: Radiation Dosimetry and Practical Therapy Solutions - 08: A Low-Cost Optical Scanner and Gantry for use with 3D Printing of Radiation Therapy Accessories

International Nuclear Information System (INIS)

Rickey, Daniel; Sasaki, David; Dubey, Arbind; Harris, Chad; Johnson, Kate; Egtberts, Andy; Koul, Rashmi

2016-01-01

Purpose: Three-dimensional printing has been implemented at our institution to create customized treatment accessories including shielding and bolus. In order to effectively use 3D printing, the topography of the patient must first be acquired. To this end, we have evaluated a low-cost structured-light 3D scanner in order to assess the clinical viability of this technology. Methods: For ease of use, the scanner (3D Systems, Sense 3D Scanner) was mounted in a simple gantry that guided its motion and maintained an optimum distance between the scanner and the object. To characterise the spatial accuracy of the scanner, we used a geometric phantom and an anthropomorphic head phantom. The geometric phantom was machined from plastic and had overall dimensions of 24 cm by 15 cm and included a hemispherical and a tetrahedron protrusion roughly the dimensions of an average forehead and nose respectively. Meshes acquired by the optical scanner were compared to meshes generated from high-resolution CT images. Results: Scans were acquired in under one minute. Most of the optical scans contained noticeable artefacts although in most instances these were considered minor. Using an algorithm that calculated distances between the two meshes, we found most of the optical scanner measurements agreed with those from CT to within about 1 mm for the geometric phantom and to within about 2 mm for the head phantom. Conclusion: In summary, we deemed this scanner to be clinically acceptable and it has been used to design treatment accessories for several skin cancer patients.

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

A spatio-temporally compensated acousto-optic scanner for two-photon microscopy providing large field of view.

Science.gov (United States)

Kremer, Y; Léger, J-F; Lapole, R; Honnorat, N; Candela, Y; Dieudonné, S; Bourdieu, L

2008-07-07

Acousto-optic deflectors (AOD) are promising ultrafast scanners for non-linear microscopy. Their use has been limited until now by their small scanning range and by the spatial and temporal dispersions of the laser beam going through the deflectors. We show that the use of AOD of large aperture (13mm) compared to standard deflectors allows accessing much larger field of view while minimizing spatio-temporal distortions. An acousto-optic modulator (AOM) placed at distance of the AOD is used to compensate spatial and temporal dispersions. Fine tuning of the AOM-AOD setup using a frequency-resolved optical gating (GRENOUILLE) allows elimination of pulse front tilt whereas spatial chirp is minimized thanks to the large aperture AOD.

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

Inter-symbol interference and beat noise in flexible data-rate coherent OCDMA and the BER improvement by using optical thresholding.

Science.gov (United States)

Wang, Xu; Wada, Naoya; Kitayama, Ken-Ichi

2005-12-26

Impairments of inter-symbol interference and beat noise in coherent time-spreading optical code-division-multiple-access are investigated theoretically and experimentally by sweeping the data-rate from 622 Mbps up to 10 Gbps with 511-chip superstructured fiber Bragg grating. The BER improvement by using optical thresholding technique has been verified in the experiment.

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.

Gabor-domain optical coherence microscopy with integrated dual-axis MEMS scanner for fast 3D imaging and metrology

Science.gov (United States)

Canavesi, Cristina; Cogliati, Andrea; Hayes, Adam; Santhanam, Anand P.; Tankam, Patrice; Rolland, Jannick P.

2015-10-01

Fast, robust, nondestructive 3D imaging is needed for characterization of microscopic structures in industrial and clinical applications. A custom micro-electromechanical system (MEMS)-based 2D scanner system was developed to achieve 55 kHz A-scan acquisition in a Gabor-domain optical coherence microscopy (GD-OCM) instrument with a novel multilevel GPU architecture for high-speed imaging. GD-OCM yields high-definition volumetric imaging with dynamic depth of focusing through a bio-inspired liquid lens-based microscope design, which has no moving parts and is suitable for use in a manufacturing setting or in a medical environment. A dual-axis MEMS mirror was chosen to replace two single-axis galvanometer mirrors; as a result, the astigmatism caused by the mismatch between the optical pupil and the scanning location was eliminated and a 12x reduction in volume of the scanning system was achieved. Imaging at an invariant resolution of 2 μm was demonstrated throughout a volume of 1 × 1 × 0.6 mm3, acquired in less than 2 minutes. The MEMS-based scanner resulted in improved image quality, increased robustness and lighter weight of the system - all factors that are critical for on-field deployment. A custom integrated feedback system consisting of a laser diode and a position-sensing detector was developed to investigate the impact of the resonant frequency of the MEMS and the driving signal of the scanner on the movement of the mirror. Results on the metrology of manufactured materials and characterization of tissue samples with GD-OCM are presented.

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...

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.

Classical Optical Transforms Studied in the Context of Quantum Optics via the Route of Developing Dirac's Symbolic Method

Science.gov (United States)

Fan, Hong-Yi; Lu, Hai-Liang

Via the route of developing Dirac's symbolic method and following Dirac's assertion: "⋯ for a quantum dynamic system that has a classical analogue, unitary transformation in the quantum theory is the analogue of contact transformation in the classical theory", we find the generalized Fresnel operator (GFO) corresponding to the generalized Fresnel transform (GFT) in classical optics. We derive GFO's normal product form and its canonical coherent state representation and find that GFO is the loyal representation of symplectic group multiplication rule. We show that GFT is just the transformation matrix element of GFO in the coordinate representation such that two successive GFTs is still a GFT. The ABCD rule of the Gaussian beam propagation is directly demonstrated in quantum optics. With the aid of entangled state representation the entangled Fresnel transform is proposed; new eigenfunctions of the complex fractional Fourier transform and fractional Hankel transform are obtained; the two-variable Hermite eigenmodes of light propagation are used in studying the Talbot effect in quadratic-index media; the complex wavelet transform and the condition of mother wavelet are studied in the context of quantum optics too. Moreover, quantum optical version of classical z-transforms is obtained on the basis of the eigenvector of creation operator. Throughout our discussions, the coherent state, squeezing operators and the technique of integration within an ordered product (IWOP) of operators are fully used.

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…

Symbolic behavior in regular classrooms. A specification of symbolic and non-symbolic behavior

Directory of Open Access Journals (Sweden)

Stefan eBillinger

2011-06-01

Full Text Available Students’ capabilities to use symbolic information in classroom setting could be expected to influence their possibilities to be active and participating. The development of strategies for teachers to compensate for reduced capability need specific operational definition of symbolic behavior. Fifty-three students, aged 11 to 13 years old, 29 boys and 24 girls, from three classes in the same Swedish compulsory regular school participated in the current study. After a short training sequence 25 students (47% were defined as showing symbolic behavior (symbolic, and 28 students (53% were not (non-symbolic, based on their follow-up test performances. Symbolic and non-symbolic differed significantly on post test performances (p. < .05. Surprisingly, non-symbolic behavior deteriorated their performance, while symbolic enhanced their performance (p. < .05. The results indicate that the operational definition used in the present study may be useful in further studies relating the capability to show symbolic behavior and students’ activity and participation in classroom settings.

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.

Variable-coefficient higher-order nonlinear Schroedinger model in optical fibers: Variable-coefficient bilinear form, Baecklund transformation, brightons and symbolic computation

International Nuclear Information System (INIS)

Tian Bo; Gao Yitian; Zhu Hongwu

2007-01-01

Symbolically investigated in this Letter is a variable-coefficient higher-order nonlinear Schroedinger (vcHNLS) model for ultrafast signal-routing, fiber laser systems and optical communication systems with distributed dispersion and nonlinearity management. Of physical and optical interests, with bilinear method extend, the vcHNLS model is transformed into a variable-coefficient bilinear form, and then an auto-Baecklund transformation is constructed. Constraints on coefficient functions are analyzed. Potentially observable with future optical-fiber experiments, variable-coefficient brightons are illustrated. Relevant properties and features are discussed as well. Baecklund transformation and other results of this Letter will be of certain value to the studies on inhomogeneous fiber media, core of dispersion-managed brightons, fiber amplifiers, laser systems and optical communication links with distributed dispersion and nonlinearity management

MR-guided breast biopsy and hook wire marking using a low-field (0.23 T) scanner with optical instrument tracking

International Nuclear Information System (INIS)

Blanco Sequeiros, Roberto; Reinikainen, Heli; Blanco Sequeiros, Andreas M.; Ojala, Risto; Paeaekkoe, Eija; Tervonen, Osmo; Vaara, Teuvo

2007-01-01

The purpose of this study was to evaluate the technical feasibility of MR-guided percutaneous breast biopsy (LCNB) and breast hook wire marking in a low-field (0.23 T) MRI system with optical instrument tracking. MR-guided core biopsy and/or hook wire marking was performed on 13 lesions observable at MR imaging only. Seven breast LCNBs and 10 hook wire markings were performed under MR guidance on 11 patients. The diagnosis was confirmed by excision biopsy or mastectomy in 12 lesions and with histopathological and cytological diagnosis and 12-month clinical follow-up in one lesion. All lesions seen in the high-field scanner were also successfully identified and targeted in the low-field scanner. The following procedures were typically technically successful. There were difficulties due to unsatisfactory functioning of some core biopsy guns. Detailed description of low-field MR guidance and optical tracking in breast biopsies is provided. The procedure seems accurate and safe and provides means to obtain a histological diagnosis of a breast lesion only seen with MRI. The low-field biopsy system is comparable to the high-field MRI system. MR-compatible biopsy guns need to be improved. (orig.)

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.

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

Symbolic computation and solitons of the nonlinear Schroedinger equation in inhomogeneous optical fiber media

International Nuclear Information System (INIS)

Li Biao; Chen Yong

2007-01-01

In this paper, the inhomogeneous nonlinear Schroedinger equation with the loss/gain and the frequency chirping is investigated. With the help of symbolic computation, three families of exact analytical solutions are presented by employing the extended projective Riccati equation method. From our results, many previous known results of nonlinear Schroedinger equation obtained by some authors can be recovered by means of some suitable selections of the arbitrary functions and arbitrary constants. Of optical and physical interests, soliton propagation and soliton interaction are discussed and simulated by computer, which include snake-soliton propagation and snake-solitons interaction, boomerang-like soliton propagation and boomerang-like solitons interaction, dispersion managed (DM) bright (dark) soliton propagation and DM solitons interaction

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.

Total body irradiation with a compensator fabricated using a 3D optical scanner and a 3D printer.

Science.gov (United States)

Park, So-Yeon; Kim, Jung-In; Joo, Yoon Ha; Lee, Jung Chan; Park, Jong Min

2017-05-07

We propose bilateral total body irradiation (TBI) utilizing a 3D printer and a 3D optical scanner. We acquired surface information of an anthropomorphic phantom with the 3D scanner and fabricated the 3D compensator with the 3D printer, which could continuously compensate for the lateral missing tissue of an entire body from the beam's eye view. To test the system's performance, we measured doses with optically stimulated luminescent dosimeters (OSLDs) as well as EBT3 films with the anthropomorphic phantom during TBI without a compensator, conventional bilateral TBI, and TBI with the 3D compensator (3D TBI). The 3D TBI showed the most uniform dose delivery to the phantom. From the OSLD measurements of the 3D TBI, the deviations between the measured doses and the prescription dose ranged from  -6.7% to 2.4% inside the phantom and from  -2.3% to 0.6% on the phantom's surface. From the EBT3 film measurements, the prescription dose could be delivered to the entire body of the phantom within  ±10% accuracy, except for the chest region, where tissue heterogeneity is extreme. The 3D TBI doses were much more uniform than those of the other irradiation techniques, especially in the anterior-to-posterior direction. The 3D TBI was advantageous, owing to its uniform dose delivery as well as its efficient treatment procedure.

Characterization of spectral compression of OFDM symbols using optical time lenses

DEFF Research Database (Denmark)

Røge, Kasper Meldgaard; Guan, Pengyu; Kjøller, Niels-Kristian

2015-01-01

We present a detailed investigation of a double-time-lens subsystem for spectral compression of OFDM symbols. We derive optimized parameter settings by simulations and experimental characterization. The required chirp for OFDM spectral compression is very large.......We present a detailed investigation of a double-time-lens subsystem for spectral compression of OFDM symbols. We derive optimized parameter settings by simulations and experimental characterization. The required chirp for OFDM spectral compression is very large....

SU-E-T-135: Investigation of Commercial-Grade Flatbed Scanners and a Medical- Grade Scanner for Radiochromic EBT Film Dosimetry.

Science.gov (United States)

Syh, J; Patel, B; Syh, J; Wu, H; Rosen, L; Durci, M; Katz, S; Sibata, C

2012-06-01

To evaluate the characteristics of commercial-grade flatbed scanners and medical-grade scanners for radiochromic EBT film dosimetry. Performance aspects of a Vidar Dosimetry Pro Advantage (Red), Epson 750 Pro, Microtek ArtixScan 1800f, and Microtek ScanMaker 8700 scanner for EBT2 Gafchromic film were evaluated in the categories of repeatability, maximum distinguishable optical density (OD) differentiation, OD variance, and dose curve characteristics. OD step film by Stouffer Industries containing 31 steps ranging from 0.05 to 3.62 OD was used. EBT films were irradiated with dose ranging from 20 to 600 cGy in 6×6 cm 2 field sizes and analyzed 24 hours later using RIT113 and Tomotherapy Film Analyzer software. Scans were performed in transmissive mode, landscape orientation, 16-bit image. The mean and standard deviation Analog to Digital (A/D) scanner value was measured by selecting a 3×3 mm 2 uniform area in the central region of each OD step from a total of 20 scans performed over several weeks. Repeatability was determined from the variance of OD step 0.38. Maximum distinguishable OD was defined as the last OD step whose range of A/D values does not overlap with its neighboring step. Repeatability uncertainty ranged from 0.1% for Vidar to 4% for Epson. Average standard deviation of OD steps ranged from 0.21% for Vidar to 6.4% for ArtixScan 1800f. Maximum distinguishable optical density ranged from 3.38 for Vidar to 1.32 for ScanMaker 8700. A/D range of each OD step corresponds to a dose range. Dose ranges of OD steps varied from 1% for Vidar to 20% for ScanMaker 8700. The Vidar exhibited a dose curve that utilized a broader range of OD values than the other scanners. Vidar exhibited higher maximum distinguishable OD, smaller variance in repeatability, smaller A/D value deviation per OD step, and a shallower dose curve with respect to OD. © 2012 American Association of Physicists in Medicine.

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

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.

Fast and compact optical-resolution photoacoustic microscopy using a water-proofing two-axis MEMS scanner, and a step forward to clinical applications

Science.gov (United States)

Kim, Jin Young; Lee, Changho; Lim, Geunbae; Kim, Chulhong

2016-03-01

Optical-resolution photoacoustic microscopy (OR-PAM) is a novel microscopic tool to provide in vivo optically sensitive images in biomedical research. Conventional OR-PAM systems are typically slow and bulky because of the linear scanning stages with stepping motors. For practical purposes, however, fast imaging speed and small footprint are crucial. To address these issues, we have developed a real-time compact OR-PAM system equipped with a waterproof two-axis MEMS scanner. The OR-PAM system consists of key components such as an ultrasonic transducer with a bandwidth of 50 MHz, an opto-acoustic beam combiner (BC), and an MEMS scanner. These are all installed inside a small water tank, with dimensions of 30 mm × 90 mm × 30 mm along the x-, y-, and z-axes, respectively. A pulsed laser with a repetition rate of 50 kHz is confocally aligned with the photoacoustic (PA) waves in the BC to maximize the SNRs. The fast scanning ability of the MEMS scanner fully utilizes the A-scan speed of 50 kHz. For instance, the B- and C-scan imaging speeds are 125 Hz and 0.625 Hz, respectively, when the acquired PA maximum amplitude projection image has 200 × 200 pixels along the x- and y-axes, respectively. The measured lateral resolution of 3.6 μm and axial resolution of 27 μm are sufficient to resolve the small capillaries. Finally, we have successfully obtained in vivo PA images of iris microvasculatures in mice. This real-time and compact OR-PAM system is optimized to examine small animals in clinical studies.

The Coude spectrograph and echelle scanner of the 2.7 m telescope at McDonald observatory

Science.gov (United States)

Tull, R. G.

1972-01-01

The design of the Coude spectrograph of the 2.7 m McDonald telescope is discussed. A description is given of the Coude scanner which uses the spectrograph optics, the configuration of the large echelle and the computer scanner control and data systems.

Methods and apparatus for laser beam scanners with different actuating mechanisms

Science.gov (United States)

Chen, Si-hai; Xiang, Si-hua; Wu, Xin; Dong, Shan; Xiao, Ding; Zheng, Xia-wei

2009-07-01

In this paper, 3 types of laser beam scanner are introduced. One is transmissive beam scanner, which is composed of convex and concave microlens arrays (MLAs). By moving the concave lens in the plane vertical to the optical axis, the incident beam can be deflected in two dimensions. Those two kinds of MLAs are fabricated by thermal reflow and replication process. A set of mechanical scanner frame is fabricated with the two MLAs assembling in it. The testing result shown that the beam deflection angles are 9.5° and 9.6°, in the 2 dimension(2D) with the scanning frequency of 2 HZ and 8 HZ, respectively. The second type of laser beam scanner is actuated by voice coil actuators (VCAs). Based on ANSOFT MAXWELL software, we have designed VCAs with small size and large force which have optimized properties. The model of VCAs is built using AutoCAD and is analyzed by Ansoft maxwell. According to the simulation results, high performance VCAs are fabricated and tested. The result is that the force of the VCAs is 6.39N/A, and the displacement is +/-2.5mm. A set up of beam scanner is fabricated and actuated by the designed VCAs. The testing result shown that the two dimensional scanning angle is 15° and 10° respectively at the frequency of 60HZ. The two dimensional scanning angle is 8.3° and 6° respectively at the frequency of 100HZ. The third type of scanner is actuated by amplified piezoelectric actuators (APAs). The scanning mirror is actuated by the piezoelectric (PZ) actuators with the scanning frequency of 700HZ, 250HZ and 87HZ respectively. The optical scanning angle is +/-0.5° at the three frequencies.

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.

Lisbon Symbol Database (LSD): Subjective norms for 600 symbols.

Science.gov (United States)

Prada, Marília; Rodrigues, David; Silva, Rita R; Garrido, Margarida V

2016-12-01

This article presents subjective rating norms for a new set of 600 symbols, depicting various contents (e.g., transportation, technology, and leisure activities) that can be used by researchers in different fields. Symbols were evaluated for aesthetic appeal, familiarity, visual complexity, concreteness, valence, arousal, and meaningfulness. The normative data were obtained from 388 participants, and no gender differences were found. Descriptive results (means, standard deviations, and confidence intervals) for each symbol in each dimension are presented. Overall, the dimensions were highly correlated. Additionally, participants were asked to briefly describe the meaning of each symbol. The results indicate that the present symbol set is varied, allowing for the selection of exemplars with different levels on the seven examined dimensions. This set of symbols constitutes a tool with potential for research in different areas. The database with all of the symbols is available as supplemental materials.

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.

Hidden Identification on Parts: Magnetic Machine-Readable Matrix Symbols

Science.gov (United States)

Schramm, Harry F.; Jones, Clyde S.; Roxby, Donald L.; Teed, James D.; Shih, William C. L.; Fitzpatrick, Gerald L.; Knisely, Craig

2005-01-01

All NASA parts have identification, usually expressed in terms of part number, serial number, and the like. In most cases, this identification is permanently marked directly on the part for tracking throughout its life cycle. NASA has developed a method for reading the matrix symbol through up to 15 mils (25 m) of paint (5 or 6 layers). This method of part identification involves coating selected patches on the objects with magnetic materials in matrix symbol patterns and reading the patterns by use of magneto-optical imaging equipment.

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.

Optimization of a fast optical CT scanner for nPAG gel dosimetry

Science.gov (United States)

Vandecasteele, Jan; DeDeene, Yves

2009-05-01

A fast laser scanning optical CT scanner was constructed and optimized at the Ghent university. The first images acquired were contaminated with several imaging artifacts. The origins of the artifacts were investigated. Performance characteristics of different components were measured such as the laser spot size, light attenuation by the lenses and the dynamic range of the photo-detector. The need for a differential measurement using a second photo-detector was investigated. Post processing strategies to compensate for hardware related errors were developed. Drift of the laser and of the detector was negligible. Incorrectly refractive index matching was dealt with by developing an automated matching process. When scratches on the water bath and phantom container are present, these pose a post processing challenge to eliminate the resulting artifacts from the reconstructed images Secondary laser spots due to multiple reflections need to be further investigated. The time delay in the control of the galvanometer and detector was dealt with using black strips that serve as markers of the projection position. Still some residual ringing artifacts are present. Several small volumetric test phantoms were constructed to obtain an overall picture of the accuracy.

Alternate symbol inversion for improved symbol synchronization in convolutionally coded systems

Science.gov (United States)

Simon, M. K.; Smith, J. G.

1980-01-01

Inverting alternate symbols of the encoder output of a convolutionally coded system provides sufficient density of symbol transitions to guarantee adequate symbol synchronizer performance, a guarantee otherwise lacking. Although alternate symbol inversion may increase or decrease the average transition density, depending on the data source model, it produces a maximum number of contiguous symbols without transition for a particular class of convolutional codes, independent of the data source model. Further, this maximum is sufficiently small to guarantee acceptable symbol synchronizer performance for typical applications. Subsequent inversion of alternate detected symbols permits proper decoding.

The origin of the flatbed scanner artifacts in radiochromic film dosimetry—key experiments and theoretical descriptions

Science.gov (United States)

Schoenfeld, Andreas A.; Wieker, Soeren; Harder, Dietrich; Poppe, Bjoern

2016-11-01

The optical origin of the lateral response and orientation artifacts, which occur when using EBT3 and EBT-XD radiochromic films together with flatbed scanners, has been reinvestigated by experimental and theoretical means. The common feature of these artifacts is the well-known parabolic increase in the optical density OD(x)  =  -log10 I(x)/I 0(x) versus offset x from the scanner midline (Poppinga et al 2014 Med. Phys. 41 021707). This holds for landscape and portrait orientations as well as for the three color channels. Dose-independent optical subjects, such as neutral density filters, linear polarizers, the EBT polyester foil and diffusive glass, also present the parabolic lateral artifact when scanned with a flatbed scanner. The curvature parameter c of the parabola function OD(x)  =  c 0  +  cx 2 is found to be a linear function of the dose, the parameters of which are influenced by the film orientation and film type, EBT3 or EBT-XD. The ubiquitous parabolic shape of function OD(x) is attributed (a) to the optical path-length effect (van Battum et al 2016 Phys. Med. Biol. 61 625-49), due to the increasing obliquity of the optical scanner light associated with increasing offset x from the scanner midline, and (b) and (c) to the partial polarization and scattering of the light leaving the film, which affect the ratio ~I(x)/{{I}0}(x) , thus making OD(x) increase with x 2. The orientation effect results from the changes of effects (b) and (c) associated with turning the film position, and thereby the orientation of the polymer structure of the sensitive film layer. In a comparison of experimental results obtained with selected optical subjects, the relative weights of the contributions of the optical path-length effect and the polarization and scattering of light leaving the films to the lateral response artifact have been estimated to be of the same order of magnitude. Mathematical models of these causes for the parabolic shape of function

The origin of the flatbed scanner artifacts in radiochromic film dosimetry-key experiments and theoretical descriptions.

Science.gov (United States)

Schoenfeld, Andreas A; Wieker, Soeren; Harder, Dietrich; Poppe, Bjoern

2016-11-07

The optical origin of the lateral response and orientation artifacts, which occur when using EBT3 and EBT-XD radiochromic films together with flatbed scanners, has been reinvestigated by experimental and theoretical means. The common feature of these artifacts is the well-known parabolic increase in the optical density OD(x)  =  -log 10 I(x)/I 0 (x) versus offset x from the scanner midline (Poppinga et al 2014 Med. Phys. 41 021707). This holds for landscape and portrait orientations as well as for the three color channels. Dose-independent optical subjects, such as neutral density filters, linear polarizers, the EBT polyester foil and diffusive glass, also present the parabolic lateral artifact when scanned with a flatbed scanner. The curvature parameter c of the parabola function OD(x)  =  c 0   +  cx 2 is found to be a linear function of the dose, the parameters of which are influenced by the film orientation and film type, EBT3 or EBT-XD. The ubiquitous parabolic shape of function OD(x) is attributed (a) to the optical path-length effect (van Battum et al 2016 Phys. Med. Biol. 61 625-49), due to the increasing obliquity of the optical scanner light associated with increasing offset x from the scanner midline, and (b) and (c) to the partial polarization and scattering of the light leaving the film, which affect the ratio [Formula: see text], thus making OD(x) increase with x 2 . The orientation effect results from the changes of effects (b) and (c) associated with turning the film position, and thereby the orientation of the polymer structure of the sensitive film layer. In a comparison of experimental results obtained with selected optical subjects, the relative weights of the contributions of the optical path-length effect and the polarization and scattering of light leaving the films to the lateral response artifact have been estimated to be of the same order of magnitude. Mathematical models of these causes for the parabolic shape of

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)

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.

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.

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.

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

Cross-spectrum symbol synchronization

Science.gov (United States)

Mccallister, R. D.; Simon, M. K.

1981-01-01

A popular method of symbol synchronization exploits one aspect of generalized harmonic analysis, normally referred to as the cross-spectrum. Utilizing nonlinear techniques, the input symbol energy is effectively concentrated onto multiples of the symbol clock frequency, facilitating application of conventional phase lock synchronization techniques. A general treatment of the cross-spectrum technique is developed and shown to be applicable across a broad class of symbol modulation formats. An important specific symbol synchronization application is then treated, focusing the general development to provide both insight and quantitative measure of the performance impact associated with variation in these key synchronization parameters: symbol modulation format, symbol transition probability, symbol energy to noise density ratio, and symbol rate to filter bandwidth ratio.

Symbolic Number Comparison Is Not Processed by the Analog Number System: Different Symbolic and Non-symbolic Numerical Distance and Size Effects

Directory of Open Access Journals (Sweden)

Attila Krajcsi

2018-02-01

Full Text Available HIGHLIGHTSWe test whether symbolic number comparison is handled by an analog noisy system.Analog system model has systematic biases in describing symbolic number comparison.This suggests that symbolic and non-symbolic numbers are processed by different systems.Dominant numerical cognition models suppose that both symbolic and non-symbolic numbers are processed by the Analog Number System (ANS working according to Weber's law. It was proposed that in a number comparison task the numerical distance and size effects reflect a ratio-based performance which is the sign of the ANS activation. However, increasing number of findings and alternative models propose that symbolic and non-symbolic numbers might be processed by different representations. Importantly, alternative explanations may offer similar predictions to the ANS prediction, therefore, former evidence usually utilizing only the goodness of fit of the ANS prediction is not sufficient to support the ANS account. To test the ANS model more rigorously, a more extensive test is offered here. Several properties of the ANS predictions for the error rates, reaction times, and diffusion model drift rates were systematically analyzed in both non-symbolic dot comparison and symbolic Indo-Arabic comparison tasks. It was consistently found that while the ANS model's prediction is relatively good for the non-symbolic dot comparison, its prediction is poorer and systematically biased for the symbolic Indo-Arabic comparison. We conclude that only non-symbolic comparison is supported by the ANS, and symbolic number comparisons are processed by other representation.

Hand-held optical fuel pin scanner

International Nuclear Information System (INIS)

Kirchner, T.L.; Powers, H.G.

1987-01-01

A portable, hand-held apparatus is described for optically scanning indicia imprinted about a planar end face of an article having an outer wall surface, the apparatus comprising: a supporting frame; light detector means fixed to the frame for digitizing light patterns directed thereto; indexing means on the frame for engaging the planar end face and locating the end face in a preselected focal plane on the frame. The indexing means has an inner wall surface complementary to the article wall surface for disposition thereabout and terminates in an end portion beyond the planar end face. The inner wall surface has a radially inwardly extending shoulder spaced from the end portion and engageable with the planar end face; light means directed onto the preselected focal plane; optical means mounted on the frame about a central axis, the optical means being optically interposed between the indexing means and the light detector means for directing reflected light from the preselected focal plane to the light detector means and including a dove prism centrally aligned along the central axis; and means for selectively rotating the dove prism relative to the frame about the central axis to thereby rotate the image from the focal plane as transmitted to the light detector means

Ultra-compact imaging plate scanner module using a MEMS mirror and specially designed MPPC

Science.gov (United States)

Miyamoto, Yuichi; Sasaki, Kensuke; Takasaka, Masaomi; Fujimoto, Masatoshi; Yamamoto, Koei

2017-02-01

Computed radiography (CR), which is one of the most useful methods for dental imaging and nondestructive testing, uses a phosphor imaging plate (IP) because it is flexible, reusable, and inexpensive. Conventional IP scanners utilize a galvanometer or a polygon mirror as a scanning device and a photomultiplier as an optical sensor. Microelectromechanical systems (MEMS) technology currently provides silicon-based devices and has the potential to replace such discrete devices and sensors. Using these devices, we constructed an ultra-compact IP scanner. Our extremely compact plate scanner utilizes a module that is composed of a one-dimensional MEMS mirror and a long multi-pixel photon counter (MPPC) that is combined with a specially designed wavelength filter and a rod lens. The MEMS mirror, which is a non-resonant electromagnetic type, is 2.6 mm in diameter with a recommended optical scanning angle up to +/-15°. The CR's wide dynamic range is maintained using a newly developed MPPC. The MPPC is a sort of silicon photomultiplier and is a high-sensitivity photon-counting device. To achieve such a wide dynamic range, we developed a long MPPC that has over 10,000 pixels. For size reduction and high optical efficiency, we set the MPPC close to an IP across the rod lens. To prevent the MPPC from detecting excitation light, which is much more intense than photo-stimulated light, we produced a sharp-cut wavelength filter that has a wide angle (+/-60°) of tolerance. We evaluated our constructed scanner module through gray chart and resolution chart images.

A fast dual wavelength laser beam fluid-less optical CT scanner for radiotherapy 3D gel dosimetry I: design and development

Science.gov (United States)

Ramm, Daniel

2018-02-01

Three dimensional dosimetry by optical CT readout of radiosensitive gels or solids has previously been indicated as a solution for measurement of radiotherapy 3D dose distributions. The clinical uptake of these dosimetry methods has been limited, partly due to impracticalities of the optical readout such as the expertise and labour required for refractive index fluid matching. In this work a fast laser beam optical CT scanner is described, featuring fluid-less and dual wavelength operation. A second laser with a different wavelength is used to provide an alternative reference scan to the commonly used pre-irradiation scan. Transmission data for both wavelengths is effectively acquired simultaneously, giving a single scan process. Together with the elimination of refractive index fluid matching issues, scanning practicality is substantially improved. Image quality and quantitative accuracy were assessed for both dual and single wavelength methods. The dual wavelength scan technique gave improvements in uniformity of reconstructed optical attenuation coefficients in the sample 3D volume. This was due to a reduction of artefacts caused by scan to scan changes. Optical attenuation measurement accuracy was similar for both dual and single wavelength modes of operation. These results established the basis for further work on dosimetric performance.

Symbolism in prehistoric man.

Science.gov (United States)

Facchini, F

2000-12-01

The aptitude for symbolization, characteristic of man, is revealed not only in artistic representations and funerary practices. It is exhibited by every manifestation of human activity or representation of natural phenomena that assumes or refers to a meaning. We can recognize functional symbolism (tool-making, habitative or food technology), social symbolism, (language and social communication) and spiritual symbolism (funerary practices and artistic expressions). On the basis of these concepts, research into symbolism in prehistoric man allows us to recognize forms of symbolism already in the manifestations of the most ancient humans, starting with Homo habilis (or rudolfensis). Toolmaking, social organization and organization of the territory are oriented toward survival and the life of the family group. They attest to symbolic behaviors and constitute symbolic systems by means of which man expresses himself, lives and transmits his symbolic world. The diverse forms of symbolism are discussed with reference to the different phases of prehistoric humanity.

Can symbols be ‘promoted’ or ‘demoted’?: Symbols as religious phenomena

Directory of Open Access Journals (Sweden)

Jaco Beyers

2013-03-01

Full Text Available Religious symbols are part of our world, relating to another world. In order to understand the process by which symbols grow and develop, the particular context of a symbol is important. In this article a particular theory as to what symbols are, is presented. Religion presupposes the existence of two worlds: this-worldly (profane and the other-worldly (sacred. The means of communication and reference between these two worlds are symbols. Two examples are investigated so as to indicate how symbols can over time either be demoted or promoted. In the case of the Asherah and asherah as related in the Old Testament a demotion of a symbol is illustrated. The growth of ancient Egyptian religion is an example of a possible promotion of symbols. The conditions under which these processes can occur are investigated.

A new correction method serving to eliminate the parabola effect of flatbed scanners used in radiochromic film dosimetry

Energy Technology Data Exchange (ETDEWEB)

Poppinga, D., E-mail: daniela.poppinga@uni-oldenburg.de; Schoenfeld, A. A.; Poppe, B. [Medical Radiation Physics, Carl v. Ossietzky University, Oldenburg 26127, Germany and Department for Radiation Oncology, Pius Hospital, Oldenburg 26121 (Germany); Doerner, K. J. [Radiotherapy Department, General Hospital, Celle 29223 (Germany); Blanck, O. [CyberKnife Center Northern Germany, Güstrow 18273, Germany and Department for Radiation Oncology, University Clinic Schleswig-Holstein, Lübeck 23562 (Germany); Harder, D. [Medical Physics and Biophysics, Georg-August-University, Göttingen 37073 (Germany)

2014-02-15

Purpose: The purpose of this study is the correction of the lateral scanner artifact, i.e., the effect that, on a large homogeneously exposed EBT3 film, a flatbed scanner measures different optical densities at different positions along thex axis, the axis parallel to the elongated light source. At constant dose, the measured optical densitiy profiles along this axis have a parabolic shape with significant dose dependent curvature. Therefore, the effect is shortly called the parabola effect. The objective of the algorithm developed in this study is to correct for the parabola effect. Any optical density measured at given position x is transformed into the equivalent optical density c at the apex of the parabola and then converted into the corresponding dose via the calibration of c versus dose. Methods: For the present study EBT3 films and an Epson 10000XL scanner including transparency unit were used for the analysis of the parabola effect. The films were irradiated with 6 MV photons from an Elekta Synergy accelerator in a RW3 slab phantom. In order to quantify the effect, ten film pieces with doses graded from 0 to 20.9 Gy were sequentially scanned at eight positions along thex axis and at six positions along the z axis (the movement direction of the light source) both for the portrait and landscape film orientations. In order to test the effectiveness of the new correction algorithm, the dose profiles of an open square field and an IMRT plan were measured by EBT3 films and compared with ionization chamber and ionization chamber array measurement. Results: The parabola effect has been numerically studied over the whole measuring field of the Epson 10000XL scanner for doses up to 20.9 Gy and for both film orientations. The presented algorithm transforms any optical density at positionx into the equivalent optical density that would be measured at the same dose at the apex of the parabola. This correction method has been validated up to doses of 5.2 Gy all over the

A new correction method serving to eliminate the parabola effect of flatbed scanners used in radiochromic film dosimetry

International Nuclear Information System (INIS)

Poppinga, D.; Schoenfeld, A. A.; Poppe, B.; Doerner, K. J.; Blanck, O.; Harder, D.

2014-01-01

Purpose: The purpose of this study is the correction of the lateral scanner artifact, i.e., the effect that, on a large homogeneously exposed EBT3 film, a flatbed scanner measures different optical densities at different positions along thex axis, the axis parallel to the elongated light source. At constant dose, the measured optical densitiy profiles along this axis have a parabolic shape with significant dose dependent curvature. Therefore, the effect is shortly called the parabola effect. The objective of the algorithm developed in this study is to correct for the parabola effect. Any optical density measured at given position x is transformed into the equivalent optical density c at the apex of the parabola and then converted into the corresponding dose via the calibration of c versus dose. Methods: For the present study EBT3 films and an Epson 10000XL scanner including transparency unit were used for the analysis of the parabola effect. The films were irradiated with 6 MV photons from an Elekta Synergy accelerator in a RW3 slab phantom. In order to quantify the effect, ten film pieces with doses graded from 0 to 20.9 Gy were sequentially scanned at eight positions along thex axis and at six positions along the z axis (the movement direction of the light source) both for the portrait and landscape film orientations. In order to test the effectiveness of the new correction algorithm, the dose profiles of an open square field and an IMRT plan were measured by EBT3 films and compared with ionization chamber and ionization chamber array measurement. Results: The parabola effect has been numerically studied over the whole measuring field of the Epson 10000XL scanner for doses up to 20.9 Gy and for both film orientations. The presented algorithm transforms any optical density at positionx into the equivalent optical density that would be measured at the same dose at the apex of the parabola. This correction method has been validated up to doses of 5.2 Gy all over the

A new correction method serving to eliminate the parabola effect of flatbed scanners used in radiochromic film dosimetry.

Science.gov (United States)

Poppinga, D; Schoenfeld, A A; Doerner, K J; Blanck, O; Harder, D; Poppe, B

2014-02-01

The purpose of this study is the correction of the lateral scanner artifact, i.e., the effect that, on a large homogeneously exposed EBT3 film, a flatbed scanner measures different optical densities at different positions along the x axis, the axis parallel to the elongated light source. At constant dose, the measured optical density profiles along this axis have a parabolic shape with significant dose dependent curvature. Therefore, the effect is shortly called the parabola effect. The objective of the algorithm developed in this study is to correct for the parabola effect. Any optical density measured at given position x is transformed into the equivalent optical density c at the apex of the parabola and then converted into the corresponding dose via the calibration of c versus dose. For the present study EBT3 films and an Epson 10000XL scanner including transparency unit were used for the analysis of the parabola effect. The films were irradiated with 6 MV photons from an Elekta Synergy accelerator in a RW3 slab phantom. In order to quantify the effect, ten film pieces with doses graded from 0 to 20.9 Gy were sequentially scanned at eight positions along the x axis and at six positions along the z axis (the movement direction of the light source) both for the portrait and landscape film orientations. In order to test the effectiveness of the new correction algorithm, the dose profiles of an open square field and an IMRT plan were measured by EBT3 films and compared with ionization chamber and ionization chamber array measurement. The parabola effect has been numerically studied over the whole measuring field of the Epson 10000XL scanner for doses up to 20.9 Gy and for both film orientations. The presented algorithm transforms any optical density at position x into the equivalent optical density that would be measured at the same dose at the apex of the parabola. This correction method has been validated up to doses of 5.2 Gy all over the scanner bed with 2D dose

Symbolic PathFinder: Symbolic Execution of Java Bytecode

Science.gov (United States)

Pasareanu, Corina S.; Rungta, Neha

2010-01-01

Symbolic Pathfinder (SPF) combines symbolic execution with model checking and constraint solving for automated test case generation and error detection in Java programs with unspecified inputs. In this tool, programs are executed on symbolic inputs representing multiple concrete inputs. Values of variables are represented as constraints generated from the analysis of Java bytecode. The constraints are solved using off-the shelf solvers to generate test inputs guaranteed to achieve complex coverage criteria. SPF has been used successfully at NASA, in academia, and in industry.

Concealed identification symbols and nondestructive determination of the identification symbols

Science.gov (United States)

Nance, Thomas A.; Gibbs, Kenneth M.

2014-09-16

The concealing of one or more identification symbols into a target object and the subsequent determination or reading of such symbols through non-destructive testing is described. The symbols can be concealed in a manner so that they are not visible to the human eye and/or cannot be readily revealed to the human eye without damage or destruction of the target object. The identification symbols can be determined after concealment by e.g., the compilation of multiple X-ray images. As such, the present invention can also provide e.g., a deterrent to theft and the recovery of lost or stolen objects.

SU-F-T-434: Development of a Fan-Beam Optical Scanner Using CMOS Array for Small Field Dosimetry

Energy Technology Data Exchange (ETDEWEB)

Brost, E; Warmington, L; Watanabe, Y [Department of Radiation Oncology, University of Minnesota, Minneapolis, MN (United States); Senthilkumar, S [Department of Physics, Vel Tech University, Chennai (India); Departamento de Ingeneria Fisica, DCI, Universidad de Guanajuato, Campus Leon, Guanajuato (Mexico)

2016-06-15

Purpose: To design and construct a second generation optical computed tomography (OCT) system using a fan-beam with a CMOS array detector for the 3D dosimetry with polymer gel and radiochromic solid dosimeters. The system was specifically designed for the small field dosimetry. Methods: The optical scanner used a fan-beam laser, which was produced from a collimated red laser beam (λ=620 nm) with a 15-degree laser-line generating lens. The fan-beam was sent through an index-matching bath which holds the sample stage and a sample. The emerging laser light was detected with a 2.54 cm-long CMOS array detector (512 elements). The sample stage rotated through the full 360 degree projection angles at 0.9-degree increments. Each projection was normalized to the unirradiated sample at the projection angle to correct for imperfections in the dosimeter. A larger sample could be scanned by using a motorized mirror and linearly translating the CMOS detector. The height of the sample stage was varied for a full 3D scanning. The image acquisition and motor motion was controlled by a computer. The 3D image reconstruction was accomplished by a fan-beam reconstruction algorithm. All the software was developed inhouse with MATLAB. Results: The scanner was used on both PRESAGE and PAGAT gel dosimeters. Irreconcilable refraction errors were seen with PAGAT because the fan beam laser line refracted away from the detector when the field was highly varying in 3D. With PRESAGE, this type of error was not seen. Conclusion: We could acquire tomographic images of dose distributions by the new OCT system with both polymer gel and radiochromic solid dosimeters. Preliminary results showed that the system was more suited for radiochromic solid dosimeters since the radiochromic dosimeters exhibited minimal refraction and scattering errors. We are currently working on improving the image quality by thorough characterization of the OCT system.

SU-F-T-434: Development of a Fan-Beam Optical Scanner Using CMOS Array for Small Field Dosimetry

International Nuclear Information System (INIS)

Brost, E; Warmington, L; Watanabe, Y; Senthilkumar, S

2016-01-01

Purpose: To design and construct a second generation optical computed tomography (OCT) system using a fan-beam with a CMOS array detector for the 3D dosimetry with polymer gel and radiochromic solid dosimeters. The system was specifically designed for the small field dosimetry. Methods: The optical scanner used a fan-beam laser, which was produced from a collimated red laser beam (λ=620 nm) with a 15-degree laser-line generating lens. The fan-beam was sent through an index-matching bath which holds the sample stage and a sample. The emerging laser light was detected with a 2.54 cm-long CMOS array detector (512 elements). The sample stage rotated through the full 360 degree projection angles at 0.9-degree increments. Each projection was normalized to the unirradiated sample at the projection angle to correct for imperfections in the dosimeter. A larger sample could be scanned by using a motorized mirror and linearly translating the CMOS detector. The height of the sample stage was varied for a full 3D scanning. The image acquisition and motor motion was controlled by a computer. The 3D image reconstruction was accomplished by a fan-beam reconstruction algorithm. All the software was developed inhouse with MATLAB. Results: The scanner was used on both PRESAGE and PAGAT gel dosimeters. Irreconcilable refraction errors were seen with PAGAT because the fan beam laser line refracted away from the detector when the field was highly varying in 3D. With PRESAGE, this type of error was not seen. Conclusion: We could acquire tomographic images of dose distributions by the new OCT system with both polymer gel and radiochromic solid dosimeters. Preliminary results showed that the system was more suited for radiochromic solid dosimeters since the radiochromic dosimeters exhibited minimal refraction and scattering errors. We are currently working on improving the image quality by thorough characterization of the OCT system.

Symbolic and non symbolic numerical representation in adults with and without developmental dyscalculia

Directory of Open Access Journals (Sweden)

Furman Tamar

2012-11-01

Full Text Available Abstract Background The question whether Developmental Dyscalculia (DD; a deficit in the ability to process numerical information is the result of deficiencies in the non symbolic numerical representation system (e.g., a group of dots or in the symbolic numerical representation system (e.g., Arabic numerals has been debated in scientific literature. It is accepted that the non symbolic system is divided into two different ranges, the subitizing range (i.e., quantities from 1-4 which is processed automatically and quickly, and the counting range (i.e., quantities larger than 4 which is an attention demanding procedure and is therefore processed serially and slowly. However, so far no study has tested the automaticity of symbolic and non symbolic representation in DD participants separately for the subitizing and the counting ranges. Methods DD and control participants undergo a novel version of the Stroop task, i.e., the Enumeration Stroop. They were presented with a random series of between one and nine written digits, and were asked to name either the relevant written digit (in the symbolic task or the relevant quantity of digits (in the non symbolic task while ignoring the irrelevant aspect. Result DD participants, unlike the control group, didn't show any congruency effect in the subitizing range of the non symbolic task. Conclusion These findings suggest that DD may be impaired in the ability to process symbolic numerical information or in the ability to automatically associate the two systems (i.e., the symbolic vs. the non symbolic. Additionally DD have deficiencies in the non symbolic counting range.

Symbolic and non symbolic numerical representation in adults with and without developmental dyscalculia.

Science.gov (United States)

Furman, Tamar; Rubinsten, Orly

2012-11-28

The question whether Developmental Dyscalculia (DD; a deficit in the ability to process numerical information) is the result of deficiencies in the non symbolic numerical representation system (e.g., a group of dots) or in the symbolic numerical representation system (e.g., Arabic numerals) has been debated in scientific literature. It is accepted that the non symbolic system is divided into two different ranges, the subitizing range (i.e., quantities from 1-4) which is processed automatically and quickly, and the counting range (i.e., quantities larger than 4) which is an attention demanding procedure and is therefore processed serially and slowly. However, so far no study has tested the automaticity of symbolic and non symbolic representation in DD participants separately for the subitizing and the counting ranges. DD and control participants undergo a novel version of the Stroop task, i.e., the Enumeration Stroop. They were presented with a random series of between one and nine written digits, and were asked to name either the relevant written digit (in the symbolic task) or the relevant quantity of digits (in the non symbolic task) while ignoring the irrelevant aspect. DD participants, unlike the control group, didn't show any congruency effect in the subitizing range of the non symbolic task. These findings suggest that DD may be impaired in the ability to process symbolic numerical information or in the ability to automatically associate the two systems (i.e., the symbolic vs. the non symbolic). Additionally DD have deficiencies in the non symbolic counting range.

A design study for an advanced ocean color scanner system. [spaceborne equipment

Science.gov (United States)

Kim, H. H.; Fraser, R. S.; Thompson, L. L.; Bahethi, O.

1980-01-01

Along with a colorimetric data analysis scheme, the instrumental parameters which need to be optimized in future spaceborne ocean color scanner systems are outlined. With regard to assessing atmospheric effects from ocean colorimetry, attention is given to computing size parameters of the aerosols in the atmosphere, total optical depth measurement, and the aerosol optical thickness. It is suggested that sensors based on the use of linear array technology will meet hardware objectives.

Children’s Non-symbolic, Symbolic Addition and Their Mapping Capacity at 4–7 Years Old

Directory of Open Access Journals (Sweden)

Yanjun Li

2017-07-01

Full Text Available The study aimed to examine the developmental trajectories of non-symbolic and symbolic addition capacities in children and the mapping ability between these two. We assessed 106 4- to 7-year-old children and found that 4-year-olds were able to do non-symbolic addition but not symbolic addition. Five-year-olds and older were able to do symbolic addition and their performance in symbolic addition exceeded non-symbolic addition in grade 1 (approximate age 7. These results suggested non-symbolic addition ability emerges earlier and is less affected by formal mathematical education than symbolic addition. Meanwhile, we tested children’s bi-directional mapping ability using a novel task and found that children were able to map between symbolic and non-symbolic representations of number at age 5. Their ability in mapping non-symbolic to symbolic number became more proficient in grade 1 (approximate age 7. This suggests children at age 7 have developed a relatively mature symbolic representation system.

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.

All-Optical Ultra-High-Speed OFDM to Nyquist-WDM Conversion Based on Complete Optical Fourier Transformation

DEFF Research Database (Denmark)

Guan, Pengyu; Røge, Kasper Meldgaard; Mulvad, Hans Christian Hansen

2016-01-01

We propose a novel all-optical ultra-high-speed orthogonal frequency-division multiplexing (OFDM) to Nyquist wavelength-division multiplexing (Nyquist-WDM) conversion scheme, achieved by exchanging the temporal and spectral profiles using a complete optical Fourier transformation (OFT). This scheme...... enables high-speed OFDM to Nyquist-WDM conversion without complex optical/electrical/optical conversion. The all-optical OFDM transmitter is based on the generation of OFDM symbols with a low duty cycle by rectangular temporal gating, which in combination with optical time-division multiplexing yields...... a higher symbol-rate OFDM signal. In the receiver, the converted Nyquist-WDM super-channel is WDM demultiplexed into individual Nyquist-WDM channels using a rectangular optical bandpass filter, followed by optical sampling at the intersymbol-interference free point. In the experimental demonstration...

The symbol grounding problem revisited: a thorough evaluation of the ANS mapping account and the proposal of an alternative account based on symbol-symbol associations.

Directory of Open Access Journals (Sweden)

Bert Reynvoet

2016-10-01

Full Text Available Recently, a lot of studies in the domain of numerical cognition have been published demonstrating a robust association between numerical symbol processing and individual differences in mathematics achievement. Because numerical symbols are so important for mathematics achievement, many researchers want to provide an answer on the ‘symbol grounding problem’, i.e., how does a symbol acquires its numerical meaning? The most popular account, the ANS mapping account, assumes that a symbol acquires its numerical meaning by being mapped on a non-verbal and Approximate Number System (ANS. Here, we critically evaluate four arguments that are supposed to support this account, i.e., (1 there is an evolutionary system for approximate number processing, (2 non-symbolic and symbolic number processing show the same behavioral effects, (3 non-symbolic and symbolic numbers activate the same brain regions which are also involved in more advanced calculation and (4 non-symbolic comparison is related to the performance on symbolic mathematics achievement tasks. Based on this evaluation, we conclude that all of these arguments and consequently also the mapping account are questionable. Next we explored less popular alternative, where small numerical symbols are initially mapped on a precise representation and then, in combination with increasing knowledge of the counting list result in an independent and exact symbolic system based on order relations between symbols. We evaluate this account by reviewing evidence on order judgement tasks following the same four arguments. Although further research is necessary, the available evidence so far suggests that this symbol-symbol association account should be considered as a worthy alternative of how symbols acquire their meaning.

The Symbol Grounding Problem Revisited: A Thorough Evaluation of the ANS Mapping Account and the Proposal of an Alternative Account Based on Symbol-Symbol Associations.

Science.gov (United States)

Reynvoet, Bert; Sasanguie, Delphine

2016-01-01

Recently, a lot of studies in the domain of numerical cognition have been published demonstrating a robust association between numerical symbol processing and individual differences in mathematics achievement. Because numerical symbols are so important for mathematics achievement, many researchers want to provide an answer on the 'symbol grounding problem,' i.e., how does a symbol acquires its numerical meaning? The most popular account, the approximate number system ( ANS ) mapping account , assumes that a symbol acquires its numerical meaning by being mapped on a non-verbal and ANS. Here, we critically evaluate four arguments that are supposed to support this account, i.e., (1) there is an evolutionary system for approximate number processing, (2) non-symbolic and symbolic number processing show the same behavioral effects, (3) non-symbolic and symbolic numbers activate the same brain regions which are also involved in more advanced calculation and (4) non-symbolic comparison is related to the performance on symbolic mathematics achievement tasks. Based on this evaluation, we conclude that all of these arguments and consequently also the mapping account are questionable. Next we explored less popular alternative, where small numerical symbols are initially mapped on a precise representation and then, in combination with increasing knowledge of the counting list result in an independent and exact symbolic system based on order relations between symbols. We evaluate this account by reviewing evidence on order judgment tasks following the same four arguments. Although further research is necessary, the available evidence so far suggests that this symbol-symbol association account should be considered as a worthy alternative of how symbols acquire their meaning.

The artefacts of radiochromic film dosimetry with flatbed scanners and their causation by light scattering from radiation-induced polymers.

Science.gov (United States)

Schoenfeld, Andreas A; Poppinga, Daniela; Harder, Dietrich; Doerner, Karl-Joachim; Poppe, Bjoern

2014-07-07

Optical experiments and theoretical considerations have been undertaken in order to understand the causes of the 'orientation effect' and the 'parabola effect', the artefacts impairing the desired light absorption measurement on radiochromic EBT3 films with flatbed scanners. EBT3 films exposed to doses up to 20.9 Gy were scanned with an Epson Expression 10000XL flatbed scanner in landscape and portrait orientation. The horizontally and vertically polarized light components of the scanner were determined, and another Epson Expression 10000XL flatbed scanner was disassembled to examine its optical components. The optical properties of exposed and unexposed EBT3 films were studied with incident polarized and unpolarized white light, and the transmitted red light was investigated for its polarization and scattering properties including the distribution of the scattering angles. Neutral density filters were studied for comparison. Guidance was sought from the theory of light scattering from rod-like macromolecular structures. The drastic dose-dependent variation of the transmitted total light current as function of the orientation of front and rear polarizers, interpreted by light scattering theory, shows that the radiation-induced polymerization of the monomers of EBT3 films produces light scattering oscillators preferably polarized at right angles with the coating direction of the film. The directional distribution of the scattered light is partly anisotropic, with a preferred scattering plane at right angles with the coating direction, indicating light scattering from stacks of coherently vibrating oscillators piled up along the monomer crystals. The polyester carrier film also participates in these effects. The 'orientation' and 'parabola' artefacts due to flatbed scanning of radiochromic films can be explained by the interaction of the polarization-dependent and anisotropic light scattering from exposed and unexposed EBT3 films with the quantitative difference

A scanning probe microscope for magnetoresistive cantilevers utilizing a nested scanner design for large-area scans

Directory of Open Access Journals (Sweden)

Tobias Meier

2015-02-01

Full Text Available We describe an atomic force microscope (AFM for the characterization of self-sensing tunneling magnetoresistive (TMR cantilevers. Furthermore, we achieve a large scan-range with a nested scanner design of two independent piezo scanners: a small high resolution scanner with a scan range of 5 × 5 × 5 μm3 is mounted on a large-area scanner with a scan range of 800 × 800 × 35 μm3. In order to characterize TMR sensors on AFM cantilevers as deflection sensors, the AFM is equipped with a laser beam deflection setup to measure the deflection of the cantilevers independently. The instrument is based on a commercial AFM controller and capable to perform large-area scanning directly without stitching of images. Images obtained on different samples such as calibration standard, optical grating, EPROM chip, self-assembled monolayers and atomic step-edges of gold demonstrate the high stability of the nested scanner design and the performance of self-sensing TMR cantilevers.

'demoted'?: Symbols as religious phenomena

African Journals Online (AJOL)

2013-03-06

Mar 6, 2013 ... process by which symbols grow and develop, the particular context of a symbol is important. In this article a particular theory as to what symbols are, is presented. ... of communication and reference between these two worlds are symbols. .... from a psychological perspective, understands symbols as a.

Symbolic and non-symbolic number magnitude processing in children with developmental dyscalculia.

Science.gov (United States)

Castro Cañizares, Danilka; Reigosa Crespo, Vivian; González Alemañy, Eduardo

2012-11-01

The aim of this study was to evaluate if children with Developmental Dyscalculia (DD) exhibit a general deficit in magnitude representations or a specific deficit in the connection of symbolic representations with the corresponding analogous magnitudes. DD was diagnosed using a timed arithmetic task. The experimental magnitude comparison tasks were presented in non-symbolic and symbolic formats. DD and typically developing (TD) children showed similar numerical distance and size congruity effects. However, DD children performed significantly slower in the symbolic task. These results are consistent with the access deficit hypothesis, according to which DD children's deficits are caused by difficulties accessing magnitude information from numerical symbols rather than in processing numerosities per se.

Animated symbols

DEFF Research Database (Denmark)

Frølunde, Lisbeth

2008-01-01

an analytic working model called Animated Symbols concerning critical reflection in a dialogic learning process. The model shows dialogue as interactions that involve two types of transformation: inner ‘learning processes' and outer signs and symbols. The classroom-based research study is part of a Ph...

SYMBOL AND LOGO. THE WAY IN WHICH YOUNG PEOPLE IN KRAKOW PERCEIVE SYMBOLS

Directory of Open Access Journals (Sweden)

Marta Jarzyna

2006-01-01

Full Text Available Symbols are essential elements of each culture. Thanks to them the meaning is created and tradition is kept alive. Advertising and marketing specialist quite often use the meanings of the symbols to create trademarks. In this way specialists refer to the assotiations rooted in the tradition.In my article I am trying to answer following questions: Has logo become symbol? Has logo taken over all the function of the symbol? Can we tell the difference between the meaning of the advertisement and the cultural meaning? I also want to find out, what people understand through the meaning of the symbol. Therfore I have conducted the survey among the high school students and the customers of three banks of Krakow. My researches have shown that most young people find it difficult to define the meaning of the symbol. Moreover high school students cannot show the difference between the symbol and the trade mark.

Symbol and Bit Error Rates Analysis of Hybrid PIM-CDMA

Directory of Open Access Journals (Sweden)

Ghassemlooy Z

2005-01-01

Full Text Available A hybrid pulse interval modulation code-division multiple-access (hPIM-CDMA scheme employing the strict optical orthogonal code (SOCC with unity and auto- and cross-correlation constraints for indoor optical wireless communications is proposed. In this paper, we analyse the symbol error rate (SER and bit error rate (BER of hPIM-CDMA. In the analysis, we consider multiple access interference (MAI, self-interference, and the hybrid nature of the hPIM-CDMA signal detection, which is based on the matched filter (MF. It is shown that the BER/SER performance can only be evaluated if the bit resolution conforms to the condition set by the number of consecutive false alarm pulses that might occur and be detected, so that one symbol being divided into two is unlikely to occur. Otherwise, the probability of SER and BER becomes extremely high and indeterminable. We show that for a large number of users, the BER improves when increasing the code weight . The results presented are compared with other modulation schemes.

Noncoherent Symbol Synchronization Techniques

Science.gov (United States)

Simon, Marvin

2005-01-01

Traditional methods for establishing symbol synchronization (sync) in digital communication receivers assume that carrier sync has already been established, i.e., the problem is addressed at the baseband level assuming that a 'perfect' estimate of carrier phase is available. We refer to this approach as coherent symbol sync. Since, for NRZ signaling, a suppressed carrier sync loop such as an I-Q Costas loop includes integrate-and-dump (I and D) filters in its in-phase (1) and quadrature (Q) arms, the traditional approach is to first track the carrier in the absence of symbol sync information, then feed back the symbol sync estimate to these filters, and then iterate between the two to a desirable operating level In this paper, we revisit the symbol sync problem by examining methods for obtaining such sync in the absence of carrier phase information, i.e., so-called noncoherent symbol sync loops. We compare the performance of these loops with that of a well-known coherent symbol sync loop and examine the conditions under which one is preferable over the other.

Microscopy system of atomic force based on a digital optical reading unit and a buzzer-scanner; Sistema de microscopia de fuerza atomica basada en una unidad de lectura optica digital y un escaner-zumbador

Energy Technology Data Exchange (ETDEWEB)

Dabirian, R.; Loza M, D. [Universidad de las Fuerzas Armadas-ESPE, Departamento de Ciencias de la Energia y Mecanica, Sangolqui (Ecuador); Wang, W. M.; Hwu, E. T., E-mail: whoand@gmail.com [Academia Sinica, Institute of Physics, Taipei, 11529 Taiwan (China)

2015-07-01

An astigmatic detection system (Ads) based on a compact disk/digital-versatile-disk (Cd-DVD) astigmatic optical pickup unit is presented. It can achieve a resolution better than 0.3 nm in detection of the vertical displacement and is able to detect the two-dimensional angular tilt of the object surface. Furthermore, a novel scanner design actuated by piezoelectric disk buzzers is presented. The scanner is composed of a quad-rod actuation structure and several piezoelectric disks. It can be driven directly with low-voltage and low-current sources, such as analogue outputs of a data acquisition card and enables a sufficient scanning range of up to μm. In addition, an economic, high-performance streamlined atomic force microscopy (AFM) was constructed, using the buzzer-scanner to move the sample relative to the probe, and using a Cd/DVD optical pickup unit to detect the mechanical resonance of a micro fabricated cantilever. The performance of the AFM is evaluated. The high sensitivity and high bandwidth of the detection system makes the equipment suitable for characterizing nano scale elements. An AFM using our detection system for detecting the deflection of micro fabricated cantilevers can resolve individual atomic steps on graphite surfaces. (Author)

The impact of symbolic and non-symbolic quantity on spatial learning.

Directory of Open Access Journals (Sweden)

Koleen McCrink

Full Text Available An implicit mapping of number to space via a "mental number line" occurs automatically in adulthood. Here, we systematically explore the influence of differing representations of quantity (no quantity, non-symbolic magnitudes, and symbolic numbers and directional flow of stimuli (random flow, left-to-right, or right-to-left on learning and attention via a match-to-sample working memory task. When recalling a cognitively demanding string of spatial locations, subjects performed best when information was presented right-to-left. When non-symbolic or symbolic numerical arrays were embedded in these spatial locations, and mental number line congruency prompted, this effect was attenuated and in some cases reversed. In particular, low-performing female participants who viewed increasing non-symbolic number arrays paired with the spatial locations exhibited better recall for left-to-right directional flow information relative to right-to-left, and better processing for the left side of space relative to the right side of space. The presence of symbolic number during spatial learning enhanced recall to a greater degree than non-symbolic number--especially for female participants, and especially when cognitive load is high--and this difference was independent of directional flow of information. We conclude that quantity representations have the potential to scaffold spatial memory, but this potential is subtle, and mediated by the nature of the quantity and the gender and performance level of the learner.

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.

Graphical symbol recognition

OpenAIRE

K.C. , Santosh; Wendling , Laurent

2015-01-01

International audience; The chapter focuses on one of the key issues in document image processing i.e., graphical symbol recognition. Graphical symbol recognition is a sub-field of a larger research domain: pattern recognition. The chapter covers several approaches (i.e., statistical, structural and syntactic) and specially designed symbol recognition techniques inspired by real-world industrial problems. It, in general, contains research problems, state-of-the-art methods that convey basic s...

[Symbol: see text]2 Optimized predictive image coding with [Symbol: see text]∞ bound.

Science.gov (United States)

Chuah, Sceuchin; Dumitrescu, Sorina; Wu, Xiaolin

2013-12-01

In many scientific, medical, and defense applications of image/video compression, an [Symbol: see text]∞ error bound is required. However, pure[Symbol: see text]∞-optimized image coding, colloquially known as near-lossless image coding, is prone to structured errors such as contours and speckles if the bit rate is not sufficiently high; moreover, most of the previous [Symbol: see text]∞-based image coding methods suffer from poor rate control. In contrast, the [Symbol: see text]2 error metric aims for average fidelity and hence preserves the subtlety of smooth waveforms better than the ∞ error metric and it offers fine granularity in rate control, but pure [Symbol: see text]2-based image coding methods (e.g., JPEG 2000) cannot bound individual errors as the [Symbol: see text]∞-based methods can. This paper presents a new compression approach to retain the benefits and circumvent the pitfalls of the two error metrics. A common approach of near-lossless image coding is to embed into a DPCM prediction loop a uniform scalar quantizer of residual errors. The said uniform scalar quantizer is replaced, in the proposed new approach, by a set of context-based [Symbol: see text]2-optimized quantizers. The optimization criterion is to minimize a weighted sum of the [Symbol: see text]2 distortion and the entropy while maintaining a strict [Symbol: see text]∞ error bound. The resulting method obtains good rate-distortion performance in both [Symbol: see text]2 and [Symbol: see text]∞ metrics and also increases the rate granularity. Compared with JPEG 2000, the new method not only guarantees lower [Symbol: see text]∞ error for all bit rates, but also it achieves higher PSNR for relatively high bit rates.

Symbol in View of Ambiguity

Directory of Open Access Journals (Sweden)

Mohamad reza Yousefi

2013-11-01

Full Text Available Abstract Symbol from the perspective of rhetorical word, is phrase or sentence that apparent meaning, also inspires to reader a wide range of semantic.Since exploring the complex social and political ideas in the most mysticalway and indirectreflectionsocial and political thoughts symbolically is easier, so the symbol and symbolism especially in Persian literatureespeciallyin the realm of Persian poetry, has a special appearance.In addition to the factors mentioned in the contemporary literature, according familiar in literature and the emergence of particular schools interest toambiguoussymbolization has spreadfurther, especially the symbol has all the features of art ambiguity in the poem and it isone the major factors causing uncertainty.Thus, the precise definitions and symbols of contemporary poetry could be dominant in the unwinding ambiguous symbol detection of cryptic allusions and metaphors that matches the cursor symbol to help readers.  In the literature, especially language poetry, the inability of language toreflecting obscure mystical ideas, avoid to directexpression of political and social concerns of the reader in the course of participate to creation ambiguous literary works is the main motivation towards symbol and symbolization.According widespread use of symbol and its different of species can be viewed from different perspectives.The creation of ambiguity is the main purposes of using symbols (especially in poetry, so many poets have tried to achieve this goal have to formation of similar symbols and the explanation and resolution of this issue can open new window for understanding the poetry in front of an audience.  In this paper examines the ambiguity of symbols in terms of its precise boundaries are reviewed. Ambiguity is one of the important processes and also is the key Iranian poetry its means is today poetry. In such poetry ambiguity is a need to explore the new world from a different perspective, or explore this

Symbol generators with program control

International Nuclear Information System (INIS)

Gryaznov, V.M.; Tomik, J.

1974-01-01

Methods of constructing symbol generators are described which ensure a program variation of symbol shape and setup. The symbols are formed on the basis of a point microraster. A symbol description code contains information on a symbol shape, with one digit corresponding to each microraster element. For a microraster discrete by-pass the description code is transformed into succession of illuminating pulses by means of a shift register

Political symbols and political transitions

Directory of Open Access Journals (Sweden)

Herrero de Miñón, Miguel

2006-11-01

Full Text Available Politics, Law and Psychology are fields that come together in the symbolic. This text takes evidence from those three areas to develop an analysis of political symbols and political transitions. The development of the analysis goes through three stages. The first succinctly describes the concept of transition and its meaning. The second closely examines the notion of the symbol, in terms of its definition, to explain aspects that allow us to understand it, characterise it and make its functions clear. Finally, from the author's experience as a witness and as an actor, I suggest three ways of understanding symbols in the processes of political transition: as symbols of change, as symbols of acknowledgment, and as symbols of support.

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

Bruce Springsteen as a Symbol

DEFF Research Database (Denmark)

Gitz-Johansen, Thomas

2018-01-01

The article explores how Bruce Springsteen and his music function as a symbol. The article first presents the Jungian theory of symbols and of music as symbol. The central argument of the article is that, by functioning symbolically, Springsteen has the potential to influence the psyche of his au...

The artefacts of radiochromic film dosimetry with flatbed scanners and their causation by light scattering from radiation-induced polymers

International Nuclear Information System (INIS)

Schoenfeld, Andreas A; Poppinga, Daniela; Poppe, Bjoern; Harder, Dietrich; Doerner, Karl-Joachim

2014-01-01

Optical experiments and theoretical considerations have been undertaken in order to understand the causes of the ‘orientation effect’ and the ‘parabola effect’, the artefacts impairing the desired light absorption measurement on radiochromic EBT3 films with flatbed scanners. EBT3 films exposed to doses up to 20.9 Gy were scanned with an Epson Expression 10000XL flatbed scanner in landscape and portrait orientation. The horizontally and vertically polarized light components of the scanner were determined, and another Epson Expression 10000XL flatbed scanner was disassembled to examine its optical components. The optical properties of exposed and unexposed EBT3 films were studied with incident polarized and unpolarized white light, and the transmitted red light was investigated for its polarization and scattering properties including the distribution of the scattering angles. Neutral density filters were studied for comparison. Guidance was sought from the theory of light scattering from rod-like macromolecular structures. The drastic dose-dependent variation of the transmitted total light current as function of the orientation of front and rear polarizers, interpreted by light scattering theory, shows that the radiation-induced polymerization of the monomers of EBT3 films produces light scattering oscillators preferably polarized at right angles with the coating direction of the film. The directional distribution of the scattered light is partly anisotropic, with a preferred scattering plane at right angles with the coating direction, indicating light scattering from stacks of coherently vibrating oscillators piled up along the monomer crystals. The polyester carrier film also participates in these effects. The ‘orientation’ and ‘parabola’ artefacts due to flatbed scanning of radiochromic films can be explained by the interaction of the polarization-dependent and anisotropic light scattering from exposed and unexposed EBT3 films with the quantitative

A novel 360-degree shape measurement using a simple setup with two mirrors and a laser MEMS scanner

Science.gov (United States)

Jin, Rui; Zhou, Xiang; Yang, Tao; Li, Dong; Wang, Chao

2017-09-01

There is no denying that 360-degree shape measurement technology plays an important role in the field of threedimensional optical metrology. Traditional optical 360-degree shape measurement methods are mainly two kinds: the first kind, by placing multiple scanners to achieve 360-degree measurements; the second kind, through the high-precision rotating device to get 360-degree shape model. The former increases the number of scanners and costly, while the latter using rotating devices lead to time consuming. This paper presents a low cost and fast optical 360-degree shape measurement method, which possesses the advantages of full static, fast and low cost. The measuring system consists of two mirrors with a certain angle, a laser projection system, a stereoscopic calibration block, and two cameras. And most of all, laser MEMS scanner can achieve precise movement of laser stripes without any movement mechanism, improving the measurement accuracy and efficiency. What's more, a novel stereo calibration technology presented in this paper can achieve point clouds data registration, and then get the 360-degree model of objects. A stereoscopic calibration block with special coded patterns on six sides is used in this novel stereo calibration method. Through this novel stereo calibration technology we can quickly get the 360-degree models of objects.

WindScanner.eu - a new Remote Sensing Research Infrastructure for On- and Offshore Wind Energy

DEFF Research Database (Denmark)

Mikkelsen, Torben; Siggaard Knudsen, Søren; Sjöholm, Mikael

2012-01-01

will be disseminated throughout Europe to pilot European wind energy research centers. The new research infrastructure will become an open source infrastructure that also invites collaboration with wind energy related atmospheric scientists and wind energy industry overseas. Recent achievements with 3D Wind......A new remote sensing based research infrastructure for atmospheric boundary-layer wind and turbulence measurements named WindScanner have during the past three years been in its early phase of development at DTU Wind Energy in Denmark. During the forthcoming three years the technology......Scanners and spin-off innovation activity are described. The Danish WindScanner.dk research facility is build from new and fast-scanning remote sensing equipment spurred from achievements within fiber optics and telecommunication technologies. At the same time the wind energy society has demanded excessive 3D wind...

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.

Reciprocity Laws for the Higher Tame Symbol and the Witt Symbol on an Algebraic Surface

OpenAIRE

Syder, Kirsty

2013-01-01

Parshin's higher Witt pairing on an arithmetic surface can be combined with the higher tame pairing to form a symbol taking values in the absolute abelian Galois group of the function field. We prove reciprocity laws for this symbol using techniques of Morrow for the Witt symbol and Romo for the higher tame symbol.

Symbolic PathFinder v7

DEFF Research Database (Denmark)

Luckow, Kasper Søe; Păsăreanu, Corina

2014-01-01

We describe Symbolic PathFinder v7 in terms of its updated design addressing the changes of Java PathFinder v7 and of its new optimization when computing path conditions. Furthermore, we describe the Symbolic Execution Tree Extension; a newly added feature that allows for outputting the symbolic...... execution tree that characterizes the execution paths covered during symbolic execution. The new extension can be tailored to the needs of subsequent analyses/processing facilities, and we demonstrate this by presenting SPF-Visualizer, which is a tool for customizable visualization of the symbolic execution...

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...

Ionizing-radiation warning - Supplementary symbol

International Nuclear Information System (INIS)

2007-01-01

This International Standard specifies the symbol to warn of the presence of a dangerous level of ionizing radiation from a high-level sealed radioactive source that can cause death or serious injury if handled carelessly. This symbol is not intended to replace the basic ionizing radiation symbol [ISO 361, ISO 7010:2003, Table 1 (Reference number W003)], but to supplement it by providing further information on the danger associated with the source and the necessity for untrained or uninformed members of the public to stay away from it. This symbol is recommended for use with International Atomic Energy Agency (IAEA) Category 1, 2, and 3 sealed radioactive sources. These sources are defined by the IAEA as having the ability to cause death or serious injuries. The paper informs about scope, shape, proportions and colour of the symbol, and application of the symbol. An annex provides the technical specifications of the symbol

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

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

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.

Online process monitoring at quasi-simultaneous laser transmission welding using a 3D-scanner with integrated pyrometer

Science.gov (United States)

Schmailzl, A.; Steger, S.; Dostalek, M.; Hierl, S.

2016-03-01

Quasi-simultaneous laser transmission welding is a well-known joining technique for thermoplastics and mainly used in the automotive as well as in the medical industry. For process control usually the so called set-path monitoring is used, where the weld is specified as "good" if the irradiation time is inside a defined confidence interval. However, the detection of small-sized gaps or thermal damaged zones is not possible with this technique. The analyzation of the weld seam temperature during welding offers the possibility to overcome this problem. In this approach a 3D-scanner is used instead of a scanner with flat-field optic. By using a pyrometer in combination with a 3D-scanner no color-corrected optic is needed in order to provide that laser- and detection-spot are concentric. Experimental studies on polyethylene T-joints have shown that the quality of the signal is adequate, despite the use of an optical setup with a long working distance and a small optical aperture. The effects on temperature are studied for defects like a gap in the joining zone. Therefore a notch was milled into the absorbent polymer. In case of producing housings for electronic parts the effect of an electrical wire between the joining partners is also investigated. Both defects can be identified by a local temperature deviation even at a feed rate of four meters per second. Furthermore a strategy for signal-processing is demonstrated. By this, remaining defects can be identified. Consequently an online detection of local defects is possible, which makes a dynamic process control feasible.

Self-organisation of symbolic information

Science.gov (United States)

Feistel, R.

2017-01-01

Information is encountered in two different appearances, in native form by arbitrary physical structures, or in symbolic form by coded sequences of letters or the like. The self-organised emergence of symbolic information from structural information is referred to as a ritualisation transition. Occurring at some stage in evolutionary history, ritualisation transitions have in common that after the crossover, arbitrary symbols are issued and recognised by information-processing devices, by transmitters and receivers in the sense of Shannon's communication theory. Symbolic information-processing systems exhibit the fundamental code symmetry whose key features, such as largely lossless copying or persistence under hostile conditions, may elucidate the reasons for the repeated successful occurrence of ritualisation phenomena in evolution history. Ritualisation examples are briefly reviewed such as the origin of life, the appearance of human languages, the establishment of emergent social categories such as money, or the development of digital computers. In addition to their role as carriers of symbolic information, symbols are physical structures which also represent structural information. For a thermodynamic description of symbols and their arrangements, it appears reasonable to distinguish between Boltzmann entropy, Clausius entropy and Pauling entropy. Thermodynamic properties of symbols imply that their lifetimes are limited by the 2nd law.

Ultra Fast Optical Sectioning: Signal preserving filtering and surface reconstruction

DEFF Research Database (Denmark)

Jensen, Rasmus Ramsbøl; Poel, Mike van der; Larsen, Rasmus

2011-01-01

a signal preserving ltering of the data set is done. The remaining data are used for a smooth surface re- construction creating very plausible surfaces. The data used in our work comes from a newly developed hand held 3D scanner. The scanner is an Ultra Fast Optical Sectioning scanner, which is able...

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.

The influence of math anxiety on symbolic and non-symbolic magnitude processing.

Science.gov (United States)

Dietrich, Julia F; Huber, Stefan; Moeller, Korbinian; Klein, Elise

2015-01-01

Deficits in basic numerical abilities have been investigated repeatedly as potential risk factors of math anxiety. Previous research suggested that also a deficient approximate number system (ANS), which is discussed as being the foundation for later math abilities, underlies math anxiety. However, these studies examined this hypothesis by investigating ANS acuity using a symbolic number comparison task. Recent evidence questions the view that ANS acuity can be assessed using a symbolic number comparison task. To investigate whether there is an association between math anxiety and ANS acuity, we employed both a symbolic number comparison task and a non-symbolic dot comparison task, which is currently the standard task to assess ANS acuity. We replicated previous findings regarding the association between math anxiety and the symbolic distance effect for response times. High math anxious individuals showed a larger distance effect than less math anxious individuals. However, our results revealed no association between math anxiety and ANS acuity assessed using a non-symbolic dot comparison task. Thus, our results did not provide evidence for the hypothesis that a deficient ANS underlies math anxiety. Therefore, we propose that a deficient ANS does not constitute a risk factor for the development of math anxiety. Moreover, our results suggest that previous interpretations regarding the interaction of math anxiety and the symbolic distance effect have to be updated. We suggest that impaired number comparison processes in high math anxious individuals might account for the results rather than deficient ANS representations. Finally, impaired number comparison processes might constitute a risk factor for the development of math anxiety. Implications for current models regarding the origins of math anxiety are discussed.

The influence of math anxiety on symbolic and non-symbolic magnitude processing

Directory of Open Access Journals (Sweden)

Julia Felicitas Dietrich

2015-10-01

Full Text Available Deficits in basic numerical abilities have been investigated repeatedly as potential risk factors of math anxiety. Previous research suggested that also a deficient approximate number system (ANS, which is discussed as being the foundation for later math abilities, underlies math anxiety. However, these studies examined this hypothesis by investigating ANS acuity using a symbolic number comparison task. Recent evidence questions the view that ANS acuity can be assessed using a symbolic number comparison task. To investigate whether there is an association between math anxiety and ANS acuity, we employed both a symbolic number comparison task and a non-symbolic dot comparison task, which is currently the standard task to assess ANS acuity. We replicated previous findings regarding the association between math anxiety and the symbolic distance effect for response times. High math anxious individuals showed a larger distance effect than less math anxious individuals. However, our results revealed no association between math anxiety and ANS acuity assessed using a non-symbolic dot comparison task. Thus, our results did not provide evidence for the hypothesis that a deficient ANS underlies math anxiety. Therefore, we propose that a deficient ANS does not constitute a risk factor for the development of math anxiety. Moreover, our results suggest that previous interpretations regarding the interaction of math anxiety and the symbolic distance effect have to be updated. We suggest that impaired number comparison processes in high math anxious individuals might account for the results rather than deficient ANS representations. Finally, impaired number comparison processes might constitute a risk factor for the development of math anxiety. Implications for current models regarding the origins of math anxiety are discussed.

Mathematical symbol hypothesis recognition with rejection option

OpenAIRE

Julca-Aguilar , Frank; Hirata , Nina ,; Viard-Gaudin , Christian; Mouchère , Harold; Medjkoune , Sofiane

2014-01-01

International audience; In the context of handwritten mathematical expressions recognition, a first step consist on grouping strokes (segmentation) to form symbol hypotheses: groups of strokes that might represent a symbol. Then, the symbol recognition step needs to cope with the identification of wrong segmented symbols (false hypotheses). However, previous works on symbol recognition consider only correctly segmented symbols. In this work, we focus on the problem of mathematical symbol reco...

Symbol in Point View of Ambiguity

Directory of Open Access Journals (Sweden)

Dr. M. R. Yousefi

Full Text Available Symbol from the perspective of rhetorical word, is phrase or sentence that apparent meaning, also inspires to reader a wide range of semantic.Since exploring the complex social and political ideas in the most mysticalway and indirectreflectionsocial and political thoughts symbolically is easier, so the symbol and symbolism especially in Persian literatureespeciallyin the realm of Persian poetry, has a special appearance.In addition to the factors mentioned in the contemporary literature, according familiar in literature and the emergence of particular schools interest toambiguoussymbolization has spreadfurther, especially the symbol has all the features of art ambiguity in the poem and it isone the major factors causing uncertainty.Thus, the precise definitions and symbols of contemporary poetry could be dominant in the unwinding ambiguous symbol detection of cryptic allusions and metaphors that matches the cursor symbol to help readers.In the literature, especially language poetry, the inability of language toreflecting obscure mystical ideas, avoid to directexpression of political and social concerns of the reader in the course of participate to creation ambiguous literary works is the main motivation towards symbol and symbolization.According widespread use of symbol and its different of species can be viewed from different perspectives.The creation of ambiguity is the main purposes of using symbols (especially in poetry, so many poets have tried to achieve this goal have to formation of similar symbols and the explanation and resolution of this issue can open new window for understanding the poetry in front of an audience.In this paper examines the ambiguity of symbols in terms of its precise boundaries are reviewed. Ambiguity is one of the important processes and also is the key Iranian poetry; its means is today poetry. In such poetry ambiguity is a need to explore the new world from a different perspective, or explore this complex world

Poster – 39: Using Optical Scanner and 3D Printer Technology to Create Lead Shielding for Radiotherapy of Facial Skin Cancer with Low Energy Photons

International Nuclear Information System (INIS)

Rickey, Daniel; Leylek, Ahmet; Dubey, Arbind; Sasaki, David; Harris, Chad; Butler, Jim; Sharma, Ankur; McCurdy, Boyd; Alpuche Aviles, Jorge E.

2016-01-01

Purpose: Treatment of skin cancers of the face using orthovoltage radiotherapy often requires lead shielding. However, creating a lead shield can be difficult because the face has complex and intricate contours. The traditional process involved creating a plaster mould of the patient’s face can be difficult for patients. Our goal was to develop an improved process by using an optical scanner and 3D printer technology. Methods: The oncologist defined the treatment field by drawing on each patient’s skin. Three-dimensional images were acquired using a consumer-grade optical scanner. A 3D model of each patient’s face was processed with mesh editing software before being printed on a 3D printer. Using a hammer, a 3 mm thick layer of lead was formed to closely fit the contours of the model. A hole was then cut out to define the field. Results: The lead shields created were remarkably accurate and fit the contours of the patients. The hole defining the field exposed only a minimally sized site to be exposed to radiation, while the rest of the face was protected. It was easy to obtain perfect symmetry for the definition of parallel opposed beams. Conclusion: We are routinely using this technique to build lead shielding that wraps around the patient as an alternative to cut-outs. We also use it for treatment of the tip of the nose using a parallel opposed pair beams with a wax nose block. We found this technique allows more accurate delineation of the cut-out and a more reproducible set-up.

Poster – 39: Using Optical Scanner and 3D Printer Technology to Create Lead Shielding for Radiotherapy of Facial Skin Cancer with Low Energy Photons

Energy Technology Data Exchange (ETDEWEB)

Rickey, Daniel; Leylek, Ahmet; Dubey, Arbind; Sasaki, David; Harris, Chad; Butler, Jim; Sharma, Ankur; McCurdy, Boyd; Alpuche Aviles, Jorge E. [CancerCare Manitoba, CancerCare Manitoba, CancerCare Manitoba, CancerCare Manitoba, CancerCare Manitoba, CancerCare Manitoba, CancerCare Manitoba, CancerCare Manitoba, CancerCare Manitoba (Canada)

2016-08-15

Purpose: Treatment of skin cancers of the face using orthovoltage radiotherapy often requires lead shielding. However, creating a lead shield can be difficult because the face has complex and intricate contours. The traditional process involved creating a plaster mould of the patient’s face can be difficult for patients. Our goal was to develop an improved process by using an optical scanner and 3D printer technology. Methods: The oncologist defined the treatment field by drawing on each patient’s skin. Three-dimensional images were acquired using a consumer-grade optical scanner. A 3D model of each patient’s face was processed with mesh editing software before being printed on a 3D printer. Using a hammer, a 3 mm thick layer of lead was formed to closely fit the contours of the model. A hole was then cut out to define the field. Results: The lead shields created were remarkably accurate and fit the contours of the patients. The hole defining the field exposed only a minimally sized site to be exposed to radiation, while the rest of the face was protected. It was easy to obtain perfect symmetry for the definition of parallel opposed beams. Conclusion: We are routinely using this technique to build lead shielding that wraps around the patient as an alternative to cut-outs. We also use it for treatment of the tip of the nose using a parallel opposed pair beams with a wax nose block. We found this technique allows more accurate delineation of the cut-out and a more reproducible set-up.

Symbolic signal processing

International Nuclear Information System (INIS)

Rechester, A.B.; White, R.B.

1993-01-01

Complex dynamic processes exhibit many complicated patterns of evolution. How can all these patterns be recognized using only output (observational, experimental) data without prior knowledge of the equations of motion? The powerful method for doing this is based on symbolic dynamics: (1) Present output data in symbolic form (trial language). (2) Topological and metric entropies are constructed. (3) Develop algorithms for computer optimization of entropies. (4) By maximizing entropies, find the most appropriate symbolic language for the purpose of pattern recognition. (5) Test this method using a variety of dynamical models from nonlinear science. The authors are in the process of applying this method for analysis of MHD fluctuations in tokamaks

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.

A digital transducer and digital microphone using an optical technique

Science.gov (United States)

Ghelmansarai, F. A.

1996-09-01

A transducer is devised to measure pressure, displacements or angles by optical means. This transducer delivers a digital output without relying on interferometry techniques or analogue-to-digital converters. This device is based on an optical scanner and an optical detector. An inter-digital photoconductive detector (IDPC) is employed that delivers a series of pulses, whose number depends on the scan length. A pre-objective scanning configuration is used that allows for the possibility of a flat image plane. The optical scanner provides scanning of IDPC and the generated scan length is proportional to the measurand.

Numerical and symbolic scientific computing

CERN Document Server

Langer, Ulrich

2011-01-01

The book presents the state of the art and results and also includes articles pointing to future developments. Most of the articles center around the theme of linear partial differential equations. Major aspects are fast solvers in elastoplasticity, symbolic analysis for boundary problems, symbolic treatment of operators, computer algebra, and finite element methods, a symbolic approach to finite difference schemes, cylindrical algebraic decomposition and local Fourier analysis, and white noise analysis for stochastic partial differential equations. Further numerical-symbolic topics range from

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.

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

22 CFR 42.11 - Classification symbols.

Science.gov (United States)

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Classification symbols. 42.11 Section 42.11... NATIONALITY ACT, AS AMENDED Classification and Foreign State Chargeability § 42.11 Classification symbols. A... visa symbol to show the classification of the alien. Immigrants Symbol Class Section of law Immediate...

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.

Aging and the number sense: preserved basic non-symbolic numerical processing and enhanced basic symbolic processing

Directory of Open Access Journals (Sweden)

Jade Eloise eNorris

2015-07-01

Full Text Available Aging often leads to general cognitive decline in domains such as memory and attention. The effect of aging on numerical cognition, particularly on foundational numerical skills known as the Number Sense, is not well known. Early research focused on the effect of aging on arithmetic. Recent studies have begun to investigate the impact of healthy aging on basic numerical skills, but focused on non-symbolic quantity discrimination alone. Moreover, contradictory findings have emerged. The current study aimed to further investigate the impact of aging on basic non-symbolic and symbolic numerical skills. A group of 25 younger (18-25 and 25 older adults (60-77 participated in non-symbolic and symbolic numerical comparison tasks. Mathematical and spelling abilities were also measured. Results showed that aging had no effect on foundational non-symbolic numerical skills, as both groups performed similarly (RTs, accuracy and Weber fractions (w. All participants showed decreased non-symbolic acuity (accuracy and w in trials requiring inhibition. However, aging appears to be associated with a greater decline in discrimination speed in such trials. Furthermore, aging seems to have a positive impact on mathematical ability and basic symbolic numerical processing, as older participants attained significantly higher mathematical achievement scores, and performed significantly better on the symbolic comparison task than younger participants. The findings suggest that aging and its lifetime exposure to numbers may lead to better mathematical achievement and stronger basic symbolic numerical skills. Our results further support the observation that basic non-symbolic numerical skills are resilient to aging, but that aging may exacerbate poorer performance on trials requiring inhibitory processes. These findings lend further support to the notion that preserved basic numerical skills in aging may reflect the preservation of an innate, primitive and embedded Number

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 ...

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...

Symbol synchronization in convolutionally coded systems

Science.gov (United States)

Baumert, L. D.; Mceliece, R. J.; Van Tilborg, H. C. A.

1979-01-01

Alternate symbol inversion is sometimes applied to the output of convolutional encoders to guarantee sufficient richness of symbol transition for the receiver symbol synchronizer. A bound is given for the length of the transition-free symbol stream in such systems, and those convolutional codes are characterized in which arbitrarily long transition free runs occur.

7 CFR 29.1008 - Combination symbols.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Combination symbols. 29.1008 Section 29.1008..., 13, 14 and Foreign Type 92) § 29.1008 Combination symbols. A color or group symbol used with another symbol to form the third factor of a grademark to denote a particular side or characteristic of the...

The Analysis of Mythological Symbols in Shahnameh

Directory of Open Access Journals (Sweden)

موسی پرنیان

2012-05-01

Full Text Available Recognizing symbols of Shahnameh requires an understanding of the context and condition of creation and emergence of symbol, myth and epic. Symbol has a relationship with consciousness and unconsciousness of man and constitutes the language of mythologies, legends, and epics. Thus the language of mythological and epic works is symbolic. The main theme in Iranian mythologies is the dual nature of creation, and during the passage from myth to epic the conflict between the two forces of good and evil appear in various aspects of existence. Some characters that represent symbolic and coded concepts more than other elements can be considered as symbols of the evolution of gods to kings and against them there are devilish kings as symbols of drought (Apush. The other symbolic elements analyzed in this study are: epic-romance stories, imaginary creatures, symbolic dreams of kings and heroes, symbolic numbers, symbolic patterns of flags, the symbolism of water, fire and charisma The findings of the study illustrate that people, more than other elements, are the constitutive elements of mythological symbols, and the tension between these human elements depicts the mutual conflict between good and evil in Ferdowsi’s Shahnameh. Like other elements, symbolic characters (especially kings are of symbolic value and constitute a part of constructing elements of mythological symbols in Shahname. Moreover their reputation is dependent on the extent of their benefit from “God charisma“ as the most pivotal element of their personality. Kings like Afrasiab and Zahak, due to lack of it, are the most disreputable kings. On the other hand, Fereidoon and Kaikhosro are on the top of the most reputable kings because of continuous benefit from that. This study has been conducted on the basis of library resources and has applied a descriptive-analytic method.

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.

When math operations have visuospatial meanings versus purely symbolic definitions: Which solving stages and brain regions are affected?

Science.gov (United States)

Pyke, Aryn A; Fincham, Jon M; Anderson, John R

2017-06-01

How does processing differ during purely symbolic problem solving versus when mathematical operations can be mentally associated with meaningful (here, visuospatial) referents? Learners were trained on novel math operations (↓, ↑), that were defined strictly symbolically or in terms of a visuospatial interpretation (operands mapped to dimensions of shaded areas, answer = total area). During testing (scanner session), no visuospatial representations were displayed. However, we expected visuospatially-trained learners to form mental visuospatial representations for problems, and exhibit distinct activations. Since some solution intervals were long (~10s) and visuospatial representations might only be instantiated in some stages during solving, group differences were difficult to detect when treating the solving interval as a whole. However, an HSMM-MVPA process (Anderson and Fincham, 2014a) to parse fMRI data identified four distinct problem-solving stages in each group, dubbed: 1) encode; 2) plan; 3) compute; and 4) respond. We assessed stage-specific differences across groups. During encoding, several regions implicated in general semantic processing and/or mental imagery were more active in visuospatially-trained learners, including: bilateral supramarginal, precuneus, cuneus, parahippocampus, and left middle temporal regions. Four of these regions again emerged in the computation stage: precuneus, right supramarginal/angular, left supramarginal/inferior parietal, and left parahippocampal gyrus. Thus, mental visuospatial representations may not just inform initial problem interpretation (followed by symbolic computation), but may scaffold on-going computation. In the second stage, higher activations were found among symbolically-trained solvers in frontal regions (R. medial and inferior and L. superior) and the right angular and middle temporal gyrus. Activations in contrasting regions may shed light on solvers' degree of use of symbolic versus mental

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)

Nuclear reactors; graphical symbols

International Nuclear Information System (INIS)

1987-11-01

This standard contains graphical symbols that reveal the type of nuclear reactor and is used to design graphical and technical presentations. Distinguishing features for nuclear reactors are laid down in graphical symbols. (orig.) [de

On the Symbolic Verification of Timed Systems

DEFF Research Database (Denmark)

Moeller, Jesper; Lichtenberg, Jacob; Andersen, Henrik Reif

1999-01-01

This paper describes how to analyze a timed system symbolically. That is, given a symbolic representation of a set of (timed) states (as an expression), we describe how to determine an expression that represents the set of states that can be reached either by firing a discrete transition...... or by advancing time. These operations are used to determine the set of reachable states symbolically. We also show how to symbolically determine the set of states that can reach a given set of states (i.e., a backwards step), thus making it possible to verify TCTL-formulae symbolically. The analysis is fully...... symbolic in the sense that both the discrete and the continuous part of the state space are represented symbolically. Furthermore, both the synchronous and asynchronous concurrent composition of timed systems can be performed symbolically. The symbolic representations are given as formulae expressed...

Symbolic Violence and Victimisation

DEFF Research Database (Denmark)

Pedersen, Bodil Maria

2009-01-01

has been criticised for over-generalisations, as well as for disregarding culture and the embeddedness of psychological problems in situated societal processes. The proposed paper is a contribution to this critique. It will draw on Bourdieu's concept of symbolic violence (1992). The concept connects......Nay (1999). It also undertakes a critical discussion of symbolic violence in the meanings given to victimisation and its aftermaths, as when conceptualised with the help of PTSD (e.g. may the use of concepts of this kind and the practices developed in relation to it constitute symbolic violence...... and contribute to victimisation?) Furthermore the analysis aims at unfolding an understanding of victimisation inclusive of connections between cultural/ societal practices, aspects of symbolic violence and lives of concrete subjects. The discussion takes its point of departure in theoretical deliberations...

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.

High resolution imaging of impacted CFRP composites with a fiber-optic laser-ultrasound scanner

Directory of Open Access Journals (Sweden)

Ivan Pelivanov

2016-06-01

Full Text Available Damage induced in polymer composites by various impacts must be evaluated to predict a component’s post-impact strength and residual lifetime, especially when impacts occur in structures related to human safety (in aircraft, for example. X-ray tomography is the conventional standard to study an internal structure with high resolution. However, it is of little use when the impacted area cannot be extracted from a structure. In addition, X-ray tomography is expensive and time-consuming. Recently, we have demonstrated that a kHz-rate laser-ultrasound (LU scanner is very efficient both for locating large defects and evaluating the material structure. Here, we show that high-quality images of damage produced by the LU scanner in impacted carbon-fiber reinforced polymer (CFRP composites are similar to those produced by X-ray tomograms; but they can be obtained with only single-sided access to the object under study. Potentially, the LU method can be applied to large components in-situ.

High resolution imaging of impacted CFRP composites with a fiber-optic laser-ultrasound scanner.

Science.gov (United States)

Pelivanov, Ivan; Ambroziński, Łukasz; Khomenko, Anton; Koricho, Ermias G; Cloud, Gary L; Haq, Mahmoodul; O'Donnell, Matthew

2016-06-01

Damage induced in polymer composites by various impacts must be evaluated to predict a component's post-impact strength and residual lifetime, especially when impacts occur in structures related to human safety (in aircraft, for example). X-ray tomography is the conventional standard to study an internal structure with high resolution. However, it is of little use when the impacted area cannot be extracted from a structure. In addition, X-ray tomography is expensive and time-consuming. Recently, we have demonstrated that a kHz-rate laser-ultrasound (LU) scanner is very efficient both for locating large defects and evaluating the material structure. Here, we show that high-quality images of damage produced by the LU scanner in impacted carbon-fiber reinforced polymer (CFRP) composites are similar to those produced by X-ray tomograms; but they can be obtained with only single-sided access to the object under study. Potentially, the LU method can be applied to large components in-situ.

Symbol synchronization for the TDRSS decoder

Science.gov (United States)

Costello, D. J., Jr.

1983-01-01

Each 8 bits out of the Viterbi decoder correspond to one symbol of the R/S code. Synchronization must be maintained here so that each 8-bit symbol delivered to the R/S decoder corresponds to an 8-bit symbol from the R/S encoder. Lack of synchronization, would cause an error in almost every R/S symbol since even a - 1-bit sync slip shifts every bit in each 8-bit symbol by one position, therby confusing the mapping betweeen 8-bit sequences and symbols. The error correcting capability of the R/S code would be exceeded. Possible ways to correcting this condition include: (1) designing the R/S decoder to recognize the overload and shifting the output sequence of the inner decoder to establish a different sync state; (2) using the characteristics of the inner decoder to establish symbol synchronization for the outer code, with or without a deinterleaver and an interleaver; and (3) modifying the encoder to alternate periodically between two sets of generators.

BeamOptics. A program for analytical beam optics

International Nuclear Information System (INIS)

Autin, B.; Carli, C.; D'Amico, T.; Groebner, O.; Martini, M.; Wildner, E.

1998-01-01

Analytical beam optics deals with the basic properties of the magnetic modules which compose particle accelerators in the same way as light optics was developed for telescopes, microscopes, or other instruments. The difference between photon and charged-particle optics lies in the nature of the field which acts upon the particle. The magnets of accelerators do not have the rotational symmetry of glass lenses and the computational problems are much more difficult. For this reason, the symbolic program BeamOptics has been written to assist the user in finding the parameters of systems whose complexity is better treated by computer than by hand. Symbolic results may be hard to interpret. Thin-lens models have been adopted because their description is algebraic and emphasis has been put on the existence of solutions, the number of solutions, and simple yet unknown special schemes. The program can also be applied to real machines with long elements. In that case, it works with numerical data but the results are accessible through continuous functions which provide the machine parameters at arbitrary positions along the reference orbit. The code is organized to be implemented in accelerator controls and has functions to correct all the first-order perturbations using a universal procedure. (orig.)

Deficient symbol processing in Alzheimer disease.

Science.gov (United States)

Toepper, Max; Steuwe, Carolin; Beblo, Thomas; Bauer, Eva; Boedeker, Sebastian; Thomas, Christine; Markowitsch, Hans J; Driessen, Martin; Sammer, Gebhard

2014-01-01

Symbols and signs have been suggested to improve the orientation of patients suffering from Alzheimer disease (AD). However, there are hardly any studies that confirm whether AD patients benefit from signs or symbols and which symbol characteristics might improve or impede their symbol comprehension. To address these issues, 30 AD patients and 30 matched healthy controls performed a symbol processing task (SPT) with 4 different item categories. A repeated-measures analysis of variance was run to identify impact of different item categories on performance accuracy in both the experimental groups. Moreover, SPT scores were correlated with neuropsychological test scores in a broad range of other cognitive domains. Finally, diagnostic accuracy of the SPT was calculated by a receiver-operating characteristic curve analysis. Results revealed a global symbol processing dysfunction in AD that was associated with semantic memory and executive deficits. Moreover, AD patients showed a disproportional performance decline at SPT items with visual distraction. Finally, the SPT total score showed high sensitivity and specificity in differentiating between AD patients and healthy controls. The present findings suggest that specific symbol features impede symbol processing in AD and argue for a diagnostic benefit of the SPT in neuropsychological assessment.

Sound Symbolism in Basic Vocabulary

Directory of Open Access Journals (Sweden)

Søren Wichmann

2010-04-01

Full Text Available The relationship between meanings of words and their sound shapes is to a large extent arbitrary, but it is well known that languages exhibit sound symbolism effects violating arbitrariness. Evidence for sound symbolism is typically anecdotal, however. Here we present a systematic approach. Using a selection of basic vocabulary in nearly one half of the world’s languages we find commonalities among sound shapes for words referring to same concepts. These are interpreted as due to sound symbolism. Studying the effects of sound symbolism cross-linguistically is of key importance for the understanding of language evolution.

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)

The symbolism of zombie

Directory of Open Access Journals (Sweden)

Nadine BOUDOU

2015-07-01

Full Text Available The objective of this article is to show why the zombie can be presented as a justifiable object of search for the symbolic communication. The zombie exists as symbol because the word the leading to a qualification became of current usage, what allows a widened communication. The diversity of the interpretations that he makes possible testifies of its ambivalence. That he is defined as a symbol or as a metaphor we shall see that, far from being that a lasted fad, the zombie is rich in different senses.

[Rod of Asclepius. Symbol of medicine].

Science.gov (United States)

Young, Pablo; Finn, Bárbara C; Bruetman, Julio E; Cesaro Gelos, Jorge; Trimarchi, Hernán

2013-09-01

Symbolism is one of the most archaic forms of human thoughts. Symbol derives from the Latin word symbolum, and the latter from the Greek symbolon or symballo, which means "I coincide, I make matches". The Medicine symbol represents a whole series of historical and ethical values. Asclepius Rod with one serpent entwined, has traditionally been the symbol of scientific medicine. In a misconception that has lasted 500 years, the Caduceus of Hermes, entwined by two serpents and with two wings, has been considered the symbol of Medicine. However, the Caduceus is the current symbol of Commerce. Asclepius Rod and the Caduceus of Hermes represent two professions, Medicine and Commerce that, in ethical practice, should not be mixed. Physicians should be aware of their real emblem, its historical origin and meaning.

SU-E-T-37: An Optical Investigation Into the Polarization and Scattering Effects Underlying the Artifacts of Radiochromic Film Dosimetry with Commercial Flatbed Scanners

International Nuclear Information System (INIS)

Schoenfeld, A; Poppinga, D; Poppe, B; Harder, D; Doerner, K

2014-01-01

Purpose: This study aims to investigate the optical properties of radiochromic EBT3 films on exposure to polarized incident light. Methods: An optical table setup was used to investigate the properties of exposed and unexposed EBT3 films. The films were placed with their long side horizontally and illuminated with polarized incident white light. The polarization of light with the electrical vector pointing vertically is referred to as 0°, accordingly horizontal orientation corresponds to 90°. The light transmission was measured depending on the polarization angle of the incident light and the polarization of a polarizer in front of the detector. Secondly, the scattering properties of exposed and unexposed films were measured by placing a plane convex lens behind the films and a screen in its focal plane. Thereby, the distribution of the scattering angles appears as an intensity map on the screen. The distributions of scattering angles caused by EBT3 films and by neutral density filters were compared. Results: EBT3 films show a strong dependence of the light transmission on the polarization of the incident light. With both polarizers parallel, a peak transmission was found at 90° orientation of the polarizers. With the rear polarizer at right angles with the front polarizer, peak transmissions were found at front polarizer orientations 45° and 135°. The scattering appears to be anisotropic with a preference direction parallel to the long side of the film. The portion of scattered light and the half value scattering angle both increase with the dose on the film. Conclusion: EBT3 films show dose dependent changes in polarized light transmission and anisotropic light scattering. These effects impair the light absorption measurements on exposed films performed with commercial flatbed scanners and are causing the well-known artifacts of radiochromic film dosimetry with flatbed scanners, the “orientation effect” and the “parabola effect”

NMR-CT image and symbol phantoms

International Nuclear Information System (INIS)

Hongo, Syozo; Yamaguchi, Hiroshi; Takeshita, Hiroshi

1990-01-01

We have developed Japanese phantoms in two procedures. One is described as a mathematical expression. Another is 'symbol phantoms' in 3 dimensional picture-elements, each of which symbolize an organ name. The concept and the algorithm of the symbol phantom enables us to make a phantom for a individual in terms of all his transversal section images. We got 85 transversal section images of head and trunk parts, and those of 40 legs parts by using NMR-CT. We have made the individual phantom for computation of organ doses. The transversal section images were not so clear to identify all organs needed to dose estimation that we had to do hand-editing the shapes of organs with viewing a typical section images: we could not yet make symbol phantom in a automatic editing. Symbols were coded to be visual cords as ASCII characters. After we got the symbol phantom of the first stage, we can edit it easily using a word-processor. Symbol phantom could describe more freely the shape of organs than mathematical phantom. Symbol phantom has several advantages to be an individual phantom, but the only difficult point is how to determine its end-point as a reference man when we apply the method to build the reference man. (author)

General Symbol Machines: The First Stage in the Evolution of Symbolic Communication

Directory of Open Access Journals (Sweden)

Thomas E. Dickins

2003-01-01

Full Text Available Humans uniquely form stimulus equivalence (SE classes of abstract and unrelated stimuli, i.e. if taught to match A with B and B with C, they will spontaneously match B with A, and C with B, (the relation of symmetry, and A with C (transitivity. Other species do not do this. The SE ability is possibly the consequence of a specific selection event in the Homo lineage. SE is of interest because it appears to demonstrate a facility that is core to symbolic behavior. Linguistic symbols, for example, are arbitrarily and symmetrically related to their referent such that the term banana has no resemblance to bananas but when processed can be used to discriminate bananas. Equally when bananas are perceived the term banana is readily produced. This relation is arguably the defining mark of symbolic representation. In this paper I shall detail the SE phenomenon and argue that it is evidence for a cognitive device that I term a General Symbol Machine (GSM. The GSM not only sets the background condition for subsequent linguistic evolution but also for other symbolic behaviors such as mathematical reasoning. In so doing the GSM is not particularly domain-specific. The apparent domain-specificity of, for example, natural language is a consequence of other computational developments. This introduces complexity to evolutionary arguments about cognitive architecture.

Optical Digital Disk Storage: An Application for News Libraries.

Science.gov (United States)

Crowley, Mary Jo

1988-01-01

Describes the technology, equipment, and procedures necessary for converting a historical newspaper clipping collection to optical disk storage. Alternative storage systems--microforms, laser scanners, optical storage--are also retrieved, and the advantages and disadvantages of optical storage are considered. (MES)

Multiple symbol differential detection

Science.gov (United States)

Divsalar, Dariush (Inventor); Simon, Marvin K. (Inventor)

1991-01-01

A differential detection technique for multiple phase shift keying (MPSK) signals is provided which uses a multiple symbol observation interval on the basis of which a joint decision is made regarding the phase of the received symbols. In accordance with the invention, a first difference phase is created between first and second received symbols. Next, the first difference phase is correlated with the possible values thereof to provide a first plurality of intermediate output signals. A second difference phase is next created between second and third received symbols. The second difference phase is correlated with plural possible values thereof to provide a second plurality of intermediate output signals. Next, a third difference phase is created between the first and third symbols. The third difference phase is correlated with plural possible values thereof to provide a third plurality of intermediate output signals. Each of the first plurality of intermediate outputs are combined with each of the second plurality of intermediate outputs and each of the third plurality of intermediate outputs to provide a plurality of possible output values. Finally, a joint decision is made by choosing from the plurality of possible output values the value which represents the best combined correlation of the first, second and third difference values with the possible values thereof.

Array scanner as microdensitometer surrogate: a deal with the devil or . . . a great deal?

Science.gov (United States)

Williams, Donald R.

2005-01-01

Inexpensive and easy-to-use linear and area-array scanners have frequently substituted as densitometers for low-frequency (i.e., large-area) hard copy image metrology. A number of workers and standards committees1 have in fact advocated such use. Increasingly, scanners are also being tasked for high spatial frequency, image microstructure metrology (which is usually reserved for high-performance microdensitometers that use microscope optics), photomultiplier tubes (PMT), and log amps. It is hard to resist their adoption for such use, given the convenience level. The high speed, large scan areas, auto-focus, discomfiting low cost, and low operator skill requirements of commercial off-the-shelf (COTS) scanners makes one question if their use for such purpose is somehow too good to be true. To confidently judge their limitations requires a comprehensive signal and noise spatial frequency performance evaluation with respect to available driver options. This paper will outline and demonstrate evaluation techniques that use existing ISO metrology standards for modulation transfer function (MTF), noise, and dynamic range with a comparison to the performance of a Photometric Data Systems (PDS) microdensitometer.

Array scanner as microdensitometer surrogate: a deal with the devil or… a great deal?

Science.gov (United States)

Williams, Donald R.

2004-10-01

Inexpensive and easy-to-use linear and area-array scanners have frequently substituted as densitometers for low-frequency (i.e., large-area) hard copy image metrology. A number of workers and standards committees1 have in fact advocated such use. Increasingly, scanners are also being tasked for high spatial frequency, image microstructure metrology (which is usually reserved for high-performance microdensitometers that use microscope optics), photomultiplier tubes (PMT), and log amps. It is hard to resist their adoption for such use, given the convenience level. The high speed, large scan areas, auto-focus, discomfiting low cost, and low operator skill requirements of commercial off-the-shelf (COTS) scanners makes one question if their use for such purpose is somehow too good to be true. To confidently judge their limitations requires a comprehensive signal and noise spatial frequency performance evaluation with respect to available driver options. This paper will outline and demonstrate evaluation techniques that use existing ISO metrology standards for modulation transfer function (MTF), noise, and dynamic range with a comparison to the performance of a Photometric Data Systems (PDS) microdensitometer.

Statistical Symbolic Execution with Informed Sampling

Science.gov (United States)

Filieri, Antonio; Pasareanu, Corina S.; Visser, Willem; Geldenhuys, Jaco

2014-01-01

Symbolic execution techniques have been proposed recently for the probabilistic analysis of programs. These techniques seek to quantify the likelihood of reaching program events of interest, e.g., assert violations. They have many promising applications but have scalability issues due to high computational demand. To address this challenge, we propose a statistical symbolic execution technique that performs Monte Carlo sampling of the symbolic program paths and uses the obtained information for Bayesian estimation and hypothesis testing with respect to the probability of reaching the target events. To speed up the convergence of the statistical analysis, we propose Informed Sampling, an iterative symbolic execution that first explores the paths that have high statistical significance, prunes them from the state space and guides the execution towards less likely paths. The technique combines Bayesian estimation with a partial exact analysis for the pruned paths leading to provably improved convergence of the statistical analysis. We have implemented statistical symbolic execution with in- formed sampling in the Symbolic PathFinder tool. We show experimentally that the informed sampling obtains more precise results and converges faster than a purely statistical analysis and may also be more efficient than an exact symbolic analysis. When the latter does not terminate symbolic execution with informed sampling can give meaningful results under the same time and memory limits.

Contextualizing symbol, symbolizing context

Science.gov (United States)

Maudy, Septiani Yugni; Suryadi, Didi; Mulyana, Endang

2017-08-01

When students learn algebra for the first time, inevitably they are experiencing transition from arithmetic to algebraic thinking. Once students could apprehend this essential mathematical knowledge, they are cultivating their ability in solving daily life problems by applying algebra. However, as we dig into this transitional stage, we identified possible students' learning obstacles to be dealt with seriously in order to forestall subsequent hindrance in studying more advance algebra. We come to realize this recurring problem as we undertook the processes of re-personalization and re-contextualization in which we scrutinize the very basic questions: 1) what is variable, linear equation with one variable and their relationship with the arithmetic-algebraic thinking? 2) Why student should learn such concepts? 3) How to teach those concepts to students? By positioning ourselves as a seventh grade student, we address the possibility of children to think arithmetically when confronted with the problems of linear equation with one variable. To help them thinking algebraically, Bruner's modes of representation developed contextually from concrete to abstract were delivered to enhance their interpretation toward the idea of variables. Hence, from the outset we designed the context for student to think symbolically initiated by exploring various symbols that could be contextualized in order to bridge student traversing the arithmetic-algebraic fruitfully.

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

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.

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.

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.

36 CFR 264.11 - Use of symbol.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Use of symbol. 264.11 Section... MANAGEMENT Mount St. Helens National Volcanic Monument Symbol § 264.11 Use of symbol. Except as provided in § 264.12, use of the Mount St. Helens National Volcanic Monument official symbol, including a facsimile...

Three Alternative Symbol-Lock Detectors

Science.gov (United States)

Shihabi, Mazen M.; Hinedi, Sami M.; Shah, Biren N.

1993-01-01

Three symbol-lock detectors proposed as alternatives in advanced receivers processing non-return-to-zero binary data signals. Two perform operations similar to those of older square-law and absolute-value types. However, integrals computed during nonoverlapping symbol periods and, therefore, only one integrator needed in each such detector. Proposed detectors simpler, but performances worse because noises in overlapping samples correlated, whereas noises in nonoverlapping samples not correlated. Third detector is signal-power-estimator type. Signal integrated during successive half symbol cycles, and therefore only one integrator needed. Half-cycle integrals multiplied to eliminate effect of symbol polarity, and products accumulated during M-cycle observation period to smooth out estimate of signal power. If estimated signal power exceeds threshold, delta, then lock declared.

Applications of symbolic algebraic computation

International Nuclear Information System (INIS)

Brown, W.S.; Hearn, A.C.

1979-01-01

This paper is a survey of applications of systems for symbomic algebraic computation. In most successful applications, calculations that can be taken to a given order by hand are then extended one or two more orders by computer. Furthermore, with a few notable exceptins, these applications also involve numerical computation in some way. Therefore the authors emphasize the interface between symbolic and numerical computation, including: 1. Computations with both symbolic and numerical phases. 2. Data involving both the unpredictible size and shape that typify symbolic computation and the (usually inexact) numerical values that characterize numerical computation. 3. Applications of one field to the other. It is concluded that the fields of symbolic and numerical computation can advance most fruitfully in harmony rather than in competition. (Auth.)

The effects of user factors and symbol referents on public symbol design using the stereotype production method.

Science.gov (United States)

Ng, Annie W Y; Siu, Kin Wai Michael; Chan, Chetwyn C H

2012-01-01

This study investigated the influence of user factors and symbol referents on public symbol design among older people, using the stereotype production method for collecting user ideas during the symbol design process. Thirty-one older adults were asked to draw images based on 28 public symbol referents and to indicate their familiarity with and ease with which they visualised each referent. Differences were found between the pictorial solutions generated by males and females. However, symbol design was not influenced by participants' education level, vividness of visual imagery, object imagery preference or spatial imagery preference. Both familiar and unfamiliar referents were illustrated pictorially without much difficulty by users. The more visual the referent, the less difficulty the users had in illustrating it. The findings of this study should aid the optimisation of the stereotype production method for user-involved symbol design. Copyright © 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.

7 CFR 29.3012 - Color symbols.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Color symbols. 29.3012 Section 29.3012 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Color symbols. As applied to Burley, single color symbols are as follows: L—buff, F—tan, R—red, D—dark...

7 CFR 29.1066 - Symbol (S).

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Symbol (S). 29.1066 Section 29.1066 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 92) § 29.1066 Symbol (S). As applied to Flue-cured tobacco the symbol (S) when used (a) as the...

7 CFR 29.3510 - Color symbols.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Color symbols. 29.3510 Section 29.3510 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 95) § 29.3510 Color symbols. As applied to Dark Air-cured tobacco, color symbols are L—light brown...

7 CFR 29.2259 - Color symbols.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Color symbols. 29.2259 Section 29.2259 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... symbols. As applied to this type, color symbols are: L—light brown, F—medium brown, D—dark brown, M—mixed...

7 CFR 29.1007 - Color symbols.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Color symbols. 29.1007 Section 29.1007 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 92) § 29.1007 Color symbols. As applied to flue-cured tobacco, color symbols are L—lemon, F—orange...

Data science and symbolic AI: Synergies, challenges and opportunities

KAUST Repository

Hoehndorf, Robert

2017-06-02

Symbolic approaches to artificial intelligence represent things within a domain of knowledge through physical symbols, combine symbols into symbol expressions, and manipulate symbols and symbol expressions through inference processes. While a large part of Data Science relies on statistics and applies statistical approaches to artificial intelligence, there is an increasing potential for successfully applying symbolic approaches as well. Symbolic representations and symbolic inference are close to human cognitive representations and therefore comprehensible and interpretable; they are widely used to represent data and metadata, and their specific semantic content must be taken into account for analysis of such information; and human communication largely relies on symbols, making symbolic representations a crucial part in the analysis of natural language. Here we discuss the role symbolic representations and inference can play in Data Science, highlight the research challenges from the perspective of the data scientist, and argue that symbolic methods should become a crucial component of the data scientists’ toolbox.

Data science and symbolic AI: Synergies, challenges and opportunities

KAUST Repository

Hoehndorf, Robert; Queralt-Rosinach, Nú ria

2017-01-01

Symbolic approaches to artificial intelligence represent things within a domain of knowledge through physical symbols, combine symbols into symbol expressions, and manipulate symbols and symbol expressions through inference processes. While a large part of Data Science relies on statistics and applies statistical approaches to artificial intelligence, there is an increasing potential for successfully applying symbolic approaches as well. Symbolic representations and symbolic inference are close to human cognitive representations and therefore comprehensible and interpretable; they are widely used to represent data and metadata, and their specific semantic content must be taken into account for analysis of such information; and human communication largely relies on symbols, making symbolic representations a crucial part in the analysis of natural language. Here we discuss the role symbolic representations and inference can play in Data Science, highlight the research challenges from the perspective of the data scientist, and argue that symbolic methods should become a crucial component of the data scientists’ toolbox.

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.

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.

Sound-Symbolism Boosts Novel Word Learning

Science.gov (United States)

Lockwood, Gwilym; Dingemanse, Mark; Hagoort, Peter

2016-01-01

The existence of sound-symbolism (or a non-arbitrary link between form and meaning) is well-attested. However, sound-symbolism has mostly been investigated with nonwords in forced choice tasks, neither of which are representative of natural language. This study uses ideophones, which are naturally occurring sound-symbolic words that depict sensory…

Symbol-String Sensitivity and Children's Reading

Science.gov (United States)

Pammer, Kristen; Lavis, Ruth; Hansen, Peter; Cornelissen, Piers L.

2004-01-01

In this study of primary school children, a novel "symbol-string" task is used to assess sensitivity to the position of briefly presented non-alphabetic but letter-like symbols. The results demonstrate that sensitivity in the symbol-string task explains a unique proportion of the variability in children's contextual reading accuracy. Moreover,…

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)

Performance of the split-symbol moments SNR estimator in the presence of inter-symbol interference

Science.gov (United States)

Shah, B.; Hinedi, S.

1989-01-01

The Split-Symbol Moments Estimator (SSME) is an algorithm that is designed to estimate symbol signal-to-noise ratio (SNR) in the presence of additive white Gaussian noise (AWGN). The performance of the SSME algorithm in band-limited channels is examined. The effects of the resulting inter-symbol interference (ISI) are quantified. All results obtained are in closed form and can be easily evaluated numerically for performance prediction purposes. Furthermore, they are validated through digital simulations.

Symbol recognition with kernel density matching.

Science.gov (United States)

Zhang, Wan; Wenyin, Liu; Zhang, Kun

2006-12-01

We propose a novel approach to similarity assessment for graphic symbols. Symbols are represented as 2D kernel densities and their similarity is measured by the Kullback-Leibler divergence. Symbol orientation is found by gradient-based angle searching or independent component analysis. Experimental results show the outstanding performance of this approach in various situations.

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

Cells from icons to symbols: molecularizing cell biology in the 1980s.

Science.gov (United States)

Serpente, Norberto

2011-12-01

Over centuries cells have been the target of optical and electronic microscopes as well as others technologies, with distinctive types of visual output. Whilst optical technologies produce images 'evident to the eye', the electronic and especially the molecular create images that are more elusive to conceptualization and assessment. My study applies the semiotic approach to the production of images in cell biology to capture the shift from microscopic images to non-traditional visual technologies around 1980. Here I argue that the visual shift that coincides with the growing dominance of molecular biology involves a change from iconic to symbolic forms. Copyright © 2011 Elsevier Ltd. All rights reserved.

Correspondence between quantum-optical transform and classical-optical transform explored by developing Dirac's symbolic method

Science.gov (United States)

Fan, Hong-yi; Hu, Li-yun

2012-06-01

By virtue of the new technique of performing integration over Dirac's ket-bra operators, we explore quantum optical version of classical optical transformations such as optical Fresnel transform, Hankel transform, fractional Fourier transform, Wigner transform, wavelet transform and Fresnel-Hadmard combinatorial transform etc. In this way one may gain benefit for developing classical optics theory from the research in quantum optics, or vice-versa. We cannot only find some new quantum mechanical unitary operators which correspond to the known optical transformations, deriving a new theorem for calculating quantum tomogram of density operators, but also can reveal some new classical optical transformations. For examples, we find the generalized Fresnel operator (GFO) to correspond to the generalized Fresnel transform (GFT) in classical optics. We derive GFO's normal product form and its canonical coherent state representation and find that GFO is the loyal representation of symplectic group multiplication rule. We show that GFT is just the transformation matrix element of GFO in the coordinate representation such that two successive GFTs is still a GFT. The ABCD rule of the Gaussian beam propagation is directly demonstrated in the context of quantum optics. Especially, the introduction of quantum mechanical entangled state representations opens up a new area in finding new classical optical transformations. The complex wavelet transform and the condition of mother wavelet are studied in the context of quantum optics too. Throughout our discussions, the coherent state, the entangled state representation of the two-mode squeezing operators and the technique of integration within an ordered product (IWOP) of operators are fully used. All these have confirmed Dirac's assertion: "...for a quantum dynamic system that has a classical analogue, unitary transformation in the quantum theory is the analogue of contact transformation in the classical theory".

History of international symbol for ionizing radiation

International Nuclear Information System (INIS)

Franic, Z.

1996-01-01

The year 1996 marks the 50th anniversary of the radiation warning symbol as we currently know it. It was (except the colours used) doodled out at the University of California, Berkeley, sometime in 1946 by a small group of people. The key guy responsible was Nelson Garden, then the head of the Health Chemistry Group, at the Radiation Laboratory. The radiation warning symbol should not be confused with the civil defence symbol (circle divided into six equal sections, three of these being black and three yellow), designed to identify fallout shelters. The basic radiation symbol was eventually internationally standardized by ISO code: 361-1975 (E). Variations of this symbol are frequently used in logotypes radiation protection organizations or associations. Particularly nice are those of International Radiation Protection Association (IRPA) and Croatian Radiation Protection Association (CRPA) that combines traditional Croatian motives with high technology. However, apart from speculations, there is no definite answer why did the Berkeley people chose this particular symbol. Whatever the reason was, it was very good choice because the ionizing radiation symbol is simple, readily identifiable, i.e., not similar to other warning symbols, and discernible at a large distance. (author)

7 CFR 29.2509 - Color symbols.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Color symbols. 29.2509 Section 29.2509 Agriculture...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2509 Color symbols. As applied to these types, color symbols are L—light brown, F—medium brown, D—dark brown, M—mixed or variegated VF—greenish...

Associations of non-symbolic and symbolic numerical magnitude processing with mathematical competence: a meta-analysis.

Science.gov (United States)

Schneider, Michael; Beeres, Kassandra; Coban, Leyla; Merz, Simon; Susan Schmidt, S; Stricker, Johannes; De Smedt, Bert

2017-05-01

Many studies have investigated the association between numerical magnitude processing skills, as assessed by the numerical magnitude comparison task, and broader mathematical competence, e.g. counting, arithmetic, or algebra. Most correlations were positive but varied considerably in their strengths. It remains unclear whether and to what extent the strength of these associations differs systematically between non-symbolic and symbolic magnitude comparison tasks and whether age, magnitude comparison measures or mathematical competence measures are additional moderators. We investigated these questions by means of a meta-analysis. The literature search yielded 45 articles reporting 284 effect sizes found with 17,201 participants. Effect sizes were combined by means of a two-level random-effects regression model. The effect size was significantly higher for the symbolic (r = .302, 95% CI [.243, .361]) than for the non-symbolic (r = .241, 95% CI [.198, .284]) magnitude comparison task and decreased very slightly with age. The correlation was higher for solution rates and Weber fractions than for alternative measures of comparison proficiency. It was higher for mathematical competencies that rely more heavily on the processing of magnitudes (i.e. mental arithmetic and early mathematical abilities) than for others. The results support the view that magnitude processing is reliably associated with mathematical competence over the lifespan in a wide range of tasks, measures and mathematical subdomains. The association is stronger for symbolic than for non-symbolic numerical magnitude processing. So symbolic magnitude processing might be a more eligible candidate to be targeted by diagnostic screening instruments and interventions for school-aged children and for adults. © 2016 John Wiley & Sons Ltd.

AN OPTICAL CHARACTER RECOGNITION RESEARCH AND DEMONSTRATION PROJECT.

Science.gov (United States)

1968

RESEARCH AND DEVELOPMENT OF PROTOTYPE LIBRARY SYSTEMS WHICH UTILIZE OPTICAL CHARACTER RECOGNITION INPUT HAS CENTERED AROUND OPTICAL PAGE READERS AND DOCUMENT READERS. THE STATE-OF-THE-ART OF BOTH THESE OPTICAL SCANNERS IS SUCH THAT BOTH ARE ACCEPTABLE FOR LIBRARY INPUT PREPARATION. A DEMONSTRATION PROJECT UTILIZING THE TWO TYPES OF READERS, SINCE…

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

Social Symbolic Work in Context

DEFF Research Database (Denmark)

Brincker, Benedikte

‘the good organisation’ may offer a supportive organisational framework for social symbolic work, thus promoting regional development in peripheral and poorly developed regions. Exploring what qualifies as a ‘good organisation’, the paper identifies three key elements: management, motivation......This paper reports on a research project that explores social symbolic work. The social symbolic work in question seeks to introduce education in entrepreneurship into the school curriculum in a remote part of Greenland – in order to contribute to regional development. The paper investigates how...

Incorporation of a laser range scanner into image-guided liver surgery: Surface acquisition, registration, and tracking

International Nuclear Information System (INIS)

Cash, David M.; Sinha, Tuhin K.; Chapman, William C.; Terawaki, Hiromi; Dawant, Benoit M.; Galloway, Robert L.; Miga, Michael I.

2003-01-01

As image guided surgical procedures become increasingly diverse, there will be more scenarios where point-based fiducials cannot be accurately localized for registration and rigid body assumptions no longer hold. As a result, procedures will rely more frequently on anatomical surfaces for the basis of image alignment and will require intraoperative geometric data to measure and compensate for tissue deformation in the organ. In this paper we outline methods for which a laser range scanner may be used to accomplish these tasks intraoperatively. A laser range scanner based on the optical principle of triangulation acquires a dense set of three-dimensional point data in a very rapid, noncontact fashion. Phantom studies were performed to test the ability to link range scan data with traditional modes of image-guided surgery data through localization, registration, and tracking in physical space. The experiments demonstrate that the scanner is capable of localizing point-based fiducials to within 0.2 mm and capable of achieving point and surface based registrations with target registration error of less than 2.0 mm. Tracking points in physical space with the range scanning system yields an error of 1.4±0.8 mm. Surface deformation studies were performed with the range scanner in order to determine if this device was capable of acquiring enough information for compensation algorithms. In the surface deformation studies, the range scanner was able to detect changes in surface shape due to deformation comparable to those detected by tomographic image studies. Use of the range scanner has been approved for clinical trials, and an initial intraoperative range scan experiment is presented. In all of these studies, the primary source of error in range scan data is deterministically related to the position and orientation of the surface within the scanner's field of view. However, this systematic error can be corrected, allowing the range scanner to provide a rapid, robust

The rhetoric of disenchantment through symbolism

Directory of Open Access Journals (Sweden)

Théophile Munyangeyo

2012-10-01

Full Text Available The symbolism of flowers has always been a significant part of cultures around the world due to their functional meaning in daily life. From their decorative to their aromatic role, flowers and their symbolic meaning trigger emotions, convey wishes and represent thoughts that can not be explicitly expressed. In this regard, an elaborate language based on flower symbolism was developed in many societies, to convey clear messages to the recipient. However, in some cultural contexts, although the flower symbolism has social connotations, it is mainly associated with economic references. As flowers are an essential precursor to fruits, they are inevitably a source of expectations and hence foster a set of hopes and dreams, which can ultimately lead to excitement or disappointment.Through a discourse analysis based on factional narratives, this article explores the parameters through which the symbolism of bifaceted meaning of flowers fictionalises a space that refers to the social reality. This association between the fictional world and social reference has highlighted that writing can profoundly be a means of representing social events through the rhetoric of symbolism. Through a sociological reading approach, this paper aims to analyse how the symbolism of flowers informs the rhetoric of disenchantment that can foster a content-based pedagogy in language learning where silencing practices engender imagery to exercise the freedom of expression.

Symbols of a cosmic order

Science.gov (United States)

Madjid, F. Hadi; Myers, John M.

2016-10-01

The world runs on networks over which signals communicate sequences of symbols, e.g. numerals. Examining both engineered and natural communications networks reveals an unsuspected order that depends on contact with an unpredictable entity. This order has three roots. The first is a proof within quantum theory that no evidence can ever determine its explanation, so that an agent choosing an explanation must do so unpredictably. The second root is the showing that clocks that step computers do not "tell time" but serve as self-adjusting symbol-handling agents that regulate "logically synchronized" motion in response to unpredictable disturbances. Such a clock-agent has a certain independence as well as the capacity to communicate via unpredictable symbols with other clock-agents and to adjust its own tick rate in response to that communication. The third root is the noticing of unpredictable symbol exchange in natural systems, including the transmission of symbols found in molecular biology. We introduce a symbol-handling agent as a role played in some cases by a person, for example a physicist who chooses an explanation of given experimental outcomes, and in other cases by some other biological entity, and in still other cases by an inanimate device, such as a computer-based detector used in physical measurements. While we forbear to try to explain the propensity of agents at all levels from cells to civilizations to form and operate networks of logically synchronized symbol-handling agents, we point to this propensity as an overlooked cosmic order, an order structured by the unpredictability ensuing from the proof. Appreciating the cosmic order leads to a conception of agency that replaces volition by unpredictability and reconceives the notion of objectivity in a way that makes a place for agency in the world as described by physics. Some specific implications for physics are outlined.

Two cultures - one symbol

Directory of Open Access Journals (Sweden)

O. G. Shostak

2003-06-01

Full Text Available This paper is dedicated to the question of similarities in the approach to the multilevel symbolism in Slav and Native American cultures. Ambivalent symbol of the snake is analyzed in the frame of mythological thinking. At the end the author comes to the conclusion that elements of mythological thinking are still present in everyday life and influence human behavior levels

The number and its symbolism in ancient Greece

Directory of Open Access Journals (Sweden)

Doc. dr Milena Bogdanović

2013-07-01

Full Text Available The symbols are of particular importance. They are the heart of the creative life; rather they are its core. They reveal the secrets of the unconscious mind open to the unknown and the infinite. While talking or gestures while express, we use the symbols, noting it or not. All spiritual science, all art and all art techniques encounter on their way symbols. History confirms that the symbols of each object can be obtained symbolic value, whether natural (rocks, trees, animals, planets, fire, lightning, etc... or abstract (geometrical shape, number, pace, ideas, etc.... The use of numbers as symbols is as old as language itself, but one that precedes writing, which symbolize numbers (that is, where the reality behind the external characters. The sheer numbers and their symbolism in ancient Greece and is closely associated with the philosophy and mathematics (namely arithmetic. They summarize their view of the world and everything around them. This paper draws attention to the symbolism of the numbers that were in ancient Greece.

Trauma and Symbolic Violence

DEFF Research Database (Denmark)

Pedersen, Bodil Maria

2011-01-01

- to praxis, and drawing on the concept of symbolic violence, this article contributes to their critique. In order to develop the analysis of difficulties victims may experience, they will be reconceptualised using critical psychological concepts such as 1st person perspectives and participation. The analysis...... seeks to undertake a discussion of personal meanings attributed to 'traumatisation'. It raises questions as to whether concepts of this kind and related practices may constitute symbolic violence and contribute to victimisation through looping-processes. Furthermore it aims at unfolding an understanding...... inclusive of connections between societal practices, aspects of symbolic violence, and the conduct of lives. The analysis is based on an empirical study of victimisation through rape and other forms of sexualised coercion....

Quality monitoring of extra-virgin olive oil using an optical sensor

Science.gov (United States)

Mignani, A. G.; Ciaccheri, L.; Mencaglia, A. A.; Paolesse, R.; Di Natale, C.; Del Nobile, A.; Benedetto, A.; Mentana, A.

2006-04-01

An optical sensor for the detection of olive oil aroma is presented. It is capable of distinguishing different ageing levels of extra-virgin olive oils, and shows effective potential for achieving a non destructive olfactory perception of oil ageing. The sensor is an optical scanner, fitted with an array of metalloporphyrin-based sensors. The scanner provides exposure of the sensors to the flow of the oil vapor being tested, and their sequential spectral interrogation. Spectral data are then processed using chemometric methodologies.

Graphic symbols as "the mind on paper": links between children's interpretive theory of mind and symbol understanding.

Science.gov (United States)

Myers, Lauren J; Liben, Lynn S

2012-01-01

Children gradually develop interpretive theory of mind (iToM)-the understanding that different people may interpret identical events or stimuli differently. The present study tested whether more advanced iToM underlies children's recognition that map symbols' meanings must be communicated to others when symbols are iconic (resemble their referents). Children (6-9 years; N = 80) made maps using either iconic or abstract symbols. After accounting for age, intelligence, vocabulary, and memory, iToM predicted children's success in communicating symbols' meaning to a naïve map-user when mapping tasks involved iconic (but not abstract) symbols. Findings suggest children's growing appreciation of alternative representations and of the intentional assignment of meaning, and support the contention that ToM progresses beyond mastery of false belief. © 2011 The Authors. Child Development © 2011 Society for Research in Child Development, Inc.

A Directed Acyclic Graph-Large Margin Distribution Machine Model for Music Symbol Classification.

Science.gov (United States)

Wen, Cuihong; Zhang, Jing; Rebelo, Ana; Cheng, Fanyong

2016-01-01

Optical Music Recognition (OMR) has received increasing attention in recent years. In this paper, we propose a classifier based on a new method named Directed Acyclic Graph-Large margin Distribution Machine (DAG-LDM). The DAG-LDM is an improvement of the Large margin Distribution Machine (LDM), which is a binary classifier that optimizes the margin distribution by maximizing the margin mean and minimizing the margin variance simultaneously. We modify the LDM to the DAG-LDM to solve the multi-class music symbol classification problem. Tests are conducted on more than 10000 music symbol images, obtained from handwritten and printed images of music scores. The proposed method provides superior classification capability and achieves much higher classification accuracy than the state-of-the-art algorithms such as Support Vector Machines (SVMs) and Neural Networks (NNs).

Influence of scanner, powder application, and adjustments on CAD-CAM crown misfit.

Science.gov (United States)

Prudente, Marcel S; Davi, Letícia R; Nabbout, Kemilly O; Prado, Célio J; Pereira, Leandro M; Zancopé, Karla; Neves, Flávio D

2018-03-01

The manufacturers of computer-aided design and computer-aided manufacturing (CAD-CAM) systems emphasize that new technologies can improve the marginal fit of dental crowns. However, data supporting this claim are limited. The purpose of this in vitro study was to investigate the differences among the following fabrication methods on the marginal discrepancy of dental crowns: intraoral optical scanners, powder application, and adjustments of intaglio surface. A single human premolar was fixed on a typodont and prepared to receive crowns prepared by the CEREC CAD-CAM system. Three fabrication techniques were used: digital scans using the CEREC Bluecam scanner with titanium dioxide powder (TDP), digital scans using the CEREC Omnicam scanner without TDP, and digital scans using the Omnicam scanner with TDP. Five experimental groups (n=10) were designated: Bluecam (group B), Bluecam with adjustments (group BA), Omnicam (group O), Omnicam with adjustments (group OA), and Omnicam with TDP (group OP). The specimens were scanned using microcomputed tomography to measure the vertical, horizontal, and internal fit and volumetric 3-dimensional (3D) internal fit values of each luting space. The paired t test was used to evaluate mean marginal fit change after adjustments within the same group. One-way analysis of variance and post hoc tests were used to compare groups B, O, and OP (α=.05). Mean vertical fit values ±standard deviations of group B=29.5 ±13.2 μm; BA=26.9 ±7.7 μm; O=149.4 ±64.4 μm; OA=49.4 ±12.7 μm; and OP=33.0 ±8.3 μm. Adjustments in the intaglio surface and TDP application statistically influenced the vertical fit of group O (POmnicam system had significantly higher vertical discrepancy and volumetric 3D internal fit than those fabricated using the Bluecam scanner with TDP. Adjustments of the intaglio surface improved the vertical fit of crowns made using the Omnicam scanner; however, TDP application before Omnicam scanning improved the vertical fit

Traffic-aware Elastic Optical Networks to leverage Energy Savings

DEFF Research Database (Denmark)

Turus, Ioan; Fagertun, Anna Manolova; Dittmann, Lars

2014-01-01

Because of the static nature of the deployed optical networks, large energy wastage is experienced today in production networks such as Telecom networks . With power-adaptive optical interfaces and suitable grooming procedures, we propose the design of more energy efficient transport networks....... Optical network reconfigurations are performed by GMPLS node controllers according to monitored traffic information. The investigated energy reduction strategies are simulated on two large scale transport networks (DT17 and COST37). The results show that the energy savings obtained by these strategies......-Europea n COST37 network, for both symbol-rate and modulation format adaptations significant savings are obtained . Mixed adaptation (jointly performing symbol-rate and modulation format adaptations) used together with optical grooming allows up to 4 4 % and 4 7 % power savings in DT17 and COST37 networks...

Optical scanner system for high resolution measurement of lubricant distributions on metal strips based on laser induced fluorescence

Science.gov (United States)

Holz, Philipp; Lutz, Christian; Brandenburg, Albrecht

2017-06-01

We present a new optical setup, which uses scanning mirrors in combination with laser induced fluorescence to monitor the spatial distribution of lubricant on metal sheets. Current trends in metal processing industry require forming procedures with increasing deformations. Thus a welldefined amount of lubricant is necessary to prevent the material from rupture, to reduce the wearing of the manufacturing tool as well as to prevent problems in post-deforming procedures. Therefore spatial resolved analysis of the thickness of lubricant layers is required. Current systems capture the lubricant distribution by moving sensor heads over the object along a linear axis. However the spatial resolution of these systems is insufficient at high strip speeds, e.g. at press plants. The presented technology uses fast rotating scanner mirrors to deflect a laser beam on the surface. This 405 nm laser light excites the autofluorescence of the investigated lubricants. A coaxial optic collects the fluorescence signal which is then spectrally filtered and recorded using a photomultiplier. From the acquired signal a two dimensional image is reconstructed in real time. This paper presents the sensor setup as well as its characterization. For the calibration of the system reference targets were prepared using an ink jet printer. The presented technology for the first time allows a spatial resolution in the millimetre range at production speed. The presented test system analyses an area of 300 x 300 mm² at a spatial resolution of 1.1 mm in less than 20 seconds. Despite this high speed of the measurement the limit of detection of the system described in this paper is better than 0.05 g/m² for the certified lubricant BAM K-009.

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...

Symbolic and Nonsymbolic Equivalence Tasks: The Influence of Symbols on Students with Mathematics Difficulty

Science.gov (United States)

Driver, Melissa K.; Powell, Sarah R.

2015-01-01

Students often experience difficulty with attaching meaning to mathematics symbols. Many students react to symbols, such as the equal sign, as a command to "do something" or "write an answer" without reflecting upon the proper relational meaning of the equal sign. One method for assessing equal-sign understanding is through…

Consumers recall and recognition for brand symbols

OpenAIRE

Subhani, Muhammad Imtiaz; Hasan, Syed Akif; Osman, Ms. Amber

2012-01-01

Brand Symbols are important for any brand in helping consumers to remember one’s brand at the point of purchase. In advertising different ways are used to grab attention in consumers’ mind and majorly it’s through brand recall and recognition. This research captivates the Brand Symbol concept and determines whether symbols play an important role in creating a differential impact with other brands. Secondly, it also answers that whether brand symbol is the cause of creating positive associatio...

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

Exact computation of the 9-j symbols

International Nuclear Information System (INIS)

Lai Shantao; Chiu Jingnan

1992-01-01

A useful algebraic formula for the 9-j symbol has been rewritten for convenient use on a computer. A simple FORTRAN program for the exact computation of 9-j symbols has been written for the VAX with VMS version V5,4-1 according to this formula. The results agree with the approximate values in existing literature. Some specific values of 9-j symbols needed for the intensity and alignments of three-photon nonresonant transitions are tabulated. Approximate 9-j symbol values beyond the limitation of the computer can also be computed by this program. The computer code of the exact computation of 3-j, 6-j and 9-j symbols are available through electronic mail upon request. (orig.)

Self-symbols as implicit motivators

NARCIS (Netherlands)

Holland, R.W.; Wennekers, A.M.; Bijlstra, G.; Jongenelen, M.M.; van Knippenberg, A.

2009-01-01

The present research explored the nonconscious motivational influence of self-symbols. In line with recent findings on the motivational influence of positive affect, we hypothesized that positive affect associated with self-symbols may boost motivation. In Study 1 people drank more of a beverage

Self-symbols as implicit motivators

NARCIS (Netherlands)

Holland, R.W.; Wennekers, A.M.; Bijlstra, G.; Jongenelen, M.M.; Knippenberg, A.F.M. van

2009-01-01

The present research explored the nonconscious motivational influence of self-symbols. In line with recent findings on the motivational influence of positive affect, we hypothesized that positive affect associated with self-symbols may boost motivation. In Study I people drank more of a beverage

The symbolic economy of drugs.

Science.gov (United States)

Lentacker, Antoine

2016-02-01

This essay reviews four recent studies representing a new direction in the history of pharmaceuticals and pharmaceutical science. To this end, it introduces the notion of a symbolic economy of drugs, defined as the production, circulation, and reception of signs that convey information about drugs and establish trust in them. Each of the studies under review focuses on one key signifier in this symbolic economy, namely the brand, the patent, the clinical trial, and the drug itself. Drawing on Pierre Bourdieu's theory of the economy of symbolic goods, I conceptualize these signifiers as symbolic assets, that is, as instruments of communication and credit, delivering knowledge, carrying value, and producing authority. The notion of a symbolic economy is offered with a threefold intention. First, I introduce it in order to highlight the implications of historical and anthropological work for a broader theory of the economy of drugs, thus suggesting a language for interdisciplinary conversations in the study of pharmaceuticals. Second, I deploy it in an attempt to emphasize the contributions of the recent scholarship on drugs to a critical understanding of our own contemporary ways of organizing access to drugs and information about drugs. Finally, I suggest ways in which it might be of use to scholars of other commodities and technologies.

7 CFR 29.3013 - Combination color symbols.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Combination color symbols. 29.3013 Section 29.3013..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER... Type 93) § 29.3013 Combination color symbols. As applied to Burley, combination color symbols are as...

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.

Symbolic Time Separation of Events

DEFF Research Database (Denmark)

Amon, Tod; Hulgaard, Henrik

1999-01-01

We extend the TSE~\\cite{Hulgaard95} timing analysis algorithm into the symbolic domain, that is, we allow symbolic variables to be used to specify unknown parameters of the model (essentially, unknown delays) and verification algorithms which are capable of identifying not just failure or success...

Abstract Expression Grammar Symbolic Regression

Science.gov (United States)

Korns, Michael F.

This chapter examines the use of Abstract Expression Grammars to perform the entire Symbolic Regression process without the use of Genetic Programming per se. The techniques explored produce a symbolic regression engine which has absolutely no bloat, which allows total user control of the search space and output formulas, which is faster, and more accurate than the engines produced in our previous papers using Genetic Programming. The genome is an all vector structure with four chromosomes plus additional epigenetic and constraint vectors, allowing total user control of the search space and the final output formulas. A combination of specialized compiler techniques, genetic algorithms, particle swarm, aged layered populations, plus discrete and continuous differential evolution are used to produce an improved symbolic regression sytem. Nine base test cases, from the literature, are used to test the improvement in speed and accuracy. The improved results indicate that these techniques move us a big step closer toward future industrial strength symbolic regression systems.

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

Cycloid scanning for wide field optical coherence tomography endomicroscopy and angiography in vivo

Science.gov (United States)

Liang, Kaicheng; Wang, Zhao; Ahsen, Osman O.; Lee, Hsiang-Chieh; Potsaid, Benjamin M.; Jayaraman, Vijaysekhar; Cable, Alex; Mashimo, Hiroshi; Li, Xingde; Fujimoto, James G.

2018-01-01

Devices that perform wide field-of-view (FOV) precision optical scanning are important for endoscopic assessment and diagnosis of luminal organ disease such as in gastroenterology. Optical scanning for in vivo endoscopic imaging has traditionally relied on one or more proximal mechanical actuators, limiting scan accuracy and imaging speed. There is a need for rapid and precise two-dimensional (2D) microscanning technologies to enable the translation of benchtop scanning microscopies to in vivo endoscopic imaging. We demonstrate a new cycloid scanner in a tethered capsule for ultrahigh speed, side-viewing optical coherence tomography (OCT) endomicroscopy in vivo. The cycloid capsule incorporates two scanners: a piezoelectrically actuated resonant fiber scanner to perform a precision, small FOV, fast scan and a micromotor scanner to perform a wide FOV, slow scan. Together these scanners distally scan the beam circumferentially in a 2D cycloid pattern, generating an unwrapped 1 mm × 38 mm strip FOV. Sequential strip volumes can be acquired with proximal pullback to image centimeter-long regions. Using ultrahigh speed 1.3 μm wavelength swept-source OCT at a 1.17 MHz axial scan rate, we imaged the human rectum at 3 volumes/s. Each OCT strip volume had 166 × 2322 axial scans with 8.5 μm axial and 30 μm transverse resolution. We further demonstrate OCT angiography at 0.5 volumes/s, producing volumetric images of vasculature. In addition to OCT applications, cycloid scanning promises to enable precision 2D optical scanning for other imaging modalities, including fluorescence confocal and nonlinear microscopy. PMID:29682598

Symbol interval optimization for molecular communication with drift.

Science.gov (United States)

Kim, Na-Rae; Eckford, Andrew W; Chae, Chan-Byoung

2014-09-01

In this paper, we propose a symbol interval optimization algorithm in molecular communication with drift. Proper symbol intervals are important in practical communication systems since information needs to be sent as fast as possible with low error rates. There is a trade-off, however, between symbol intervals and inter-symbol interference (ISI) from Brownian motion. Thus, we find proper symbol interval values considering the ISI inside two kinds of blood vessels, and also suggest no ISI system for strong drift models. Finally, an isomer-based molecule shift keying (IMoSK) is applied to calculate achievable data transmission rates (achievable rates, hereafter). Normalized achievable rates are also obtained and compared in one-symbol ISI and no ISI systems.

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.)

Scientific applications of symbolic computation

International Nuclear Information System (INIS)

Hearn, A.C.

1976-02-01

The use of symbolic computation systems for problem solving in scientific research is reviewed. The nature of the field is described, and particular examples are considered from celestial mechanics, quantum electrodynamics and general relativity. Symbolic integration and some more recent applications of algebra systems are also discussed [fr

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)

A Directed Acyclic Graph-Large Margin Distribution Machine Model for Music Symbol Classification.

Directory of Open Access Journals (Sweden)

Cuihong Wen

Full Text Available Optical Music Recognition (OMR has received increasing attention in recent years. In this paper, we propose a classifier based on a new method named Directed Acyclic Graph-Large margin Distribution Machine (DAG-LDM. The DAG-LDM is an improvement of the Large margin Distribution Machine (LDM, which is a binary classifier that optimizes the margin distribution by maximizing the margin mean and minimizing the margin variance simultaneously. We modify the LDM to the DAG-LDM to solve the multi-class music symbol classification problem. Tests are conducted on more than 10000 music symbol images, obtained from handwritten and printed images of music scores. The proposed method provides superior classification capability and achieves much higher classification accuracy than the state-of-the-art algorithms such as Support Vector Machines (SVMs and Neural Networks (NNs.

New symbol launched to warn public about radiation dangers. Supplementary symbol aims to help reduce needless deaths and injuries

International Nuclear Information System (INIS)

2007-01-01

Full text: With radiating waves, a skull and crossbones and a running person, a new ionizing radiation warning symbol is being introduced to supplement the traditional international symbol for radiation, the three cornered trefoil. The new symbol is being launched today by the IAEA and the International Organization for Standardization (ISO) to help reduce needless deaths and serious injuries from accidental exposure to large radioactive sources. It will serve as a supplementary warning to the trefoil, which has no intuitive meaning and little recognition beyond those educated in its significance. 'I believe the international recognition of the specific expertise of both organizations will ensure that the new standard will be accepted and applied by governments and industry to improve the safety of nuclear applications, protection of people and the environment', said Ms. Eliana Amaral, Director, Division of Radiation, Transport and Waste Safety, IAEA. The new symbol is aimed at alerting anyone, anywhere to the potential dangers of being close to a large source of ionizing radiation, the result of a five-year project conducted in 11 countries around the world. The symbol was tested with different population groups - mixed ages, varying educational backgrounds, male and female - to ensure that its message of 'danger- stay away' was crystal clear and understood by all. 'We can't teach the world about radiation,' said Carolyn Mac Kenzie, an IAEA radiation specialist who helped develop the symbol, 'but we can warn people about dangerous sources for the price of sticker.' The new symbol, developed by human factor experts, graphic artists, and radiation protection experts, was tested by the Gallup Institute on a total of 1 650 individuals in Brazil, Mexico, Morocco, Kenya, Saudi Arabia, China, India, Thailand, Poland, Ukraine and the United States. The symbol is intended for IAEA Category 1, 2 and 3 sources defined as dangerous sources capable of death or serious injury

New symbol launched to warn public about radiation dangers. Supplementary symbol aims to help reduce needless deaths and injuries

International Nuclear Information System (INIS)

2007-01-01

Full text: With radiating waves, a skull and crossbones and a running person, a new ionizing radiation warning symbol is being introduced to supplement the traditional international symbol for radiation, the three cornered trefoil. The new symbol is being launched today by the IAEA and the International Organization for Standardization (ISO) to help reduce needless deaths and serious injuries from accidental exposure to large radioactive sources. It will serve as a supplementary warning to the trefoil, which has no intuitive meaning and little recognition beyond those educated in its significance. 'I believe the international recognition of the specific expertise of both organizations will ensure that the new standard will be accepted and applied by governments and industry to improve the safety of nuclear applications, protection of people and the environment', said Ms. Eliana Amaral, Director, Division of Radiation, Transport and Waste Safety, IAEA. The new symbol is aimed at alerting anyone, anywhere to the potential dangers of being close to a large source of ionizing radiation, the result of a five-year project conducted in 11 countries around the world. The symbol was tested with different population groups - mixed ages, varying educational backgrounds, male and female - to ensure that its message of 'danger- stay away' was crystal clear and understood by all. 'We can't teach the world about radiation,' said Carolyn Mac Kenzie, an IAEA radiation specialist who helped develop the symbol, 'but we can warn people about dangerous sources for the price of sticker.' The new symbol, developed by human factor experts, graphic artists, and radiation protection experts, was tested by the Gallup Institute on a total of 1 650 individuals in Brazil, Mexico, Morocco, Kenya, Saudi Arabia, China, India, Thailand, Poland, Ukraine and the United States. The symbol is intended for IAEA Category 1, 2 and 3 sources defined as dangerous sources capable of death or serious injury

New symbol launched to warn public about radiation dangers. Supplementary symbol aims to help reduce needless deaths and injuries

International Nuclear Information System (INIS)

2007-01-01

Full text: With radiating waves, a skull and crossbones and a running person, a new ionizing radiation warning symbol is being introduced to supplement the traditional international symbol for radiation, the three cornered trefoil. The new symbol is being launched today by the IAEA and the International Organization for Standardization (ISO) to help reduce needless deaths and serious injuries from accidental exposure to large radioactive sources. It will serve as a supplementary warning to the trefoil, which has no intuitive meaning and little recognition beyond those educated in its significance. 'I believe the international recognition of the specific expertise of both organizations will ensure that the new standard will be accepted and applied by governments and industry to improve the safety of nuclear applications, protection of people and the environment', said Ms. Eliana Amaral, Director, Division of Radiation, Transport and Waste Safety, IAEA. The new symbol is aimed at alerting anyone, anywhere to the potential dangers of being close to a large source of ionizing radiation, the result of a five-year project conducted in 11 countries around the world. The symbol was tested with different population groups - mixed ages, varying educational backgrounds, male and female - to ensure that its message of 'danger- stay away' was crystal clear and understood by all. 'We can't teach the world about radiation,' said Carolyn Mac Kenzie, an IAEA radiation specialist who helped develop the symbol, 'but we can warn people about dangerous sources for the price of sticker.' The new symbol, developed by human factor experts, graphic artists, and radiation protection experts, was tested by the Gallup Institute on a total of 1 650 individuals in Brazil, Mexico, Morocco, Kenya, Saudi Arabia, China, India, Thailand, Poland, Ukraine and the United States. The symbol is intended for IAEA Category 1, 2 and 3 sources defined as dangerous sources capable of death or serious injury

New symbol launched to warn public about radiation dangers. Supplementary symbol aims to help reduce needless deaths and injuries

International Nuclear Information System (INIS)

2007-01-01

Full text: With radiating waves, a skull and crossbones and a running person, a new ionizing radiation warning symbol is being introduced to supplement the traditional international symbol for radiation, the three cornered trefoil. The new symbol is being launched today by the IAEA and the International Organization for Standardization (ISO) to help reduce needless deaths and serious injuries from accidental exposure to large radioactive sources. It will serve as a supplementary warning to the trefoil, which has no intuitive meaning and little recognition beyond those educated in its significance. 'I believe the international recognition of the specific expertise of both organizations will ensure that the new standard will be accepted and applied by governments and industry to improve the safety of nuclear applications, protection of people and the environment', said Ms. Eliana Amaral, Director, Division of Radiation, Transport and Waste Safety, IAEA. The new symbol is aimed at alerting anyone, anywhere to the potential dangers of being close to a large source of ionizing radiation, the result of a five-year project conducted in 11 countries around the world. The symbol was tested with different population groups - mixed ages, varying educational backgrounds, male and female - to ensure that its message of 'danger- stay away' was crystal clear and understood by all. 'We can't teach the world about radiation,' said Carolyn Mac Kenzie, an IAEA radiation specialist who helped develop the symbol, 'but we can warn people about dangerous sources for the price of sticker.' The new symbol, developed by human factor experts, graphic artists, and radiation protection experts, was tested by the Gallup Institute on a total of 1 650 individuals in Brazil, Mexico, Morocco, Kenya, Saudi Arabia, China, India, Thailand, Poland, Ukraine and the United States. The symbol is intended for IAEA Category 1, 2 and 3 sources defined as dangerous sources capable of death or serious injury

Proportional Symbol Mapping in R

Directory of Open Access Journals (Sweden)

Susumu Tanimura

2006-01-01

Full Text Available Visualization of spatial data on a map aids not only in data exploration but also in communication to impart spatial conception or ideas to others. Although recent carto-graphic functions in R are rapidly becoming richer, proportional symbol mapping, which is one of the common mapping approaches, has not been packaged thus far. Based on the theories of proportional symbol mapping developed in cartography, the authors developed some functions for proportional symbol mapping using R, including mathematical and perceptual scaling. An example of these functions demonstrated the new expressive power and options available in R, particularly for the visualization of conceptual point data.

Symbolic Dynamics of Reanalysis Data

Science.gov (United States)

Larson, J. W.; Dickens, P. M.

2003-12-01

Symbolic dynamics1 is the study of sequences of symbols belonging to a discrete set of elements, the most commmon example being a sequence of ones and zeroes. Often the set of symbols is derived from a timeseries of a continuous variable through the introduction of a partition function--a process called symbolization. Symbolic dynamics has been used widely in the physical sciences; a geophysical example being the application of C1 and C2 complexity2 to hourly precipitation station data3. The C1 and C2 complexities are computed by examining subsequences--or words--of fixed length L in the limit of large values of L. Recent advances in information theory have led to techniques focused on the growth rate of the Shannon entropy and its asymptotic behavior in the limit of long words--levels of entropy convergence4. The result is a set of measures one can use to quantify the amount of memory stored in the sequence, whether or not an observer is able to synchronize to the sequence, and with what confidence it may be predicted. These techniques may also be used to uncover periodic behavior in the sequence. We are currently applying complexity theory and levels of entropy convergence to gridpoint timeseries from the NCAR/NCEP 50-year reanalysis5. Topics to be discussed include: a brief introduction to symbolic dynamics; a description of the partition function/symbolization strategy; a discussion of C1 and C2 complexity and entropy convergence rates and their utility; and example applications of these techniques to NCAR/NCEP 50-reanalyses gridpoint timeseries, resulting in maps of C1 and C2 complexities and entropy convergence rates. Finally, we will discuss how these results may be used to validate climate models. 1{Hao, Bai-Lin, Elementary Symbolic Dynamics and Chaos in Dissipative Systems, Wold Scientific, Singapore (1989)} 2{d'Alessandro, G. and Politi, A., Phys. Rev. Lett., 64, 1609-1612 (1990).} 3{Elsner, J. and Tsonis, A., J. Atmos. Sci., 50, 400-405 (1993).} 4

The rhetoric of disenchantment through symbolism

OpenAIRE

Munyangeyo, Théophile

2012-01-01

The symbolism of flowers has always been a significant part of cultures around the world due to their functional meaning in daily life. From their decorative to their aromatic role, flowers and their symbolic meaning trigger emotions, convey wishes and represent thoughts that can not be explicitly expressed. In this regard, an elaborate language based on flower symbolism was developed in many societies, to convey clear messages to the recipient. However, in some cultural contexts, although th...

14 CFR 95.3 - Symbols.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Symbols. 95.3 Section 95.3 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES IFR ALTITUDES General § 95.3 Symbols. For the purposes of this part— (a) COP means...

50 CFR 80.26 - Symbols.

Science.gov (United States)

2010-10-01

... appropriate symbol(s) on areas, such as wildlife management areas and fishing access facilities, acquired..., losses and damages arising out of any allegedly unauthorized use of any patent, process, idea, method or... and also from any claims, suits, losses and damages arising out of alleged defects in the articles or...

46 CFR 50.10-25 - Coast Guard Symbol.

Science.gov (United States)

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Coast Guard Symbol. 50.10-25 Section 50.10-25 Shipping... Definition of Terms Used in This Subchapter § 50.10-25 Coast Guard Symbol. (a) The term Coast Guard Symbol... impression of the Coast Guard Symbol for stamping nameplates and specimens is shown in Figure 50.10-25(b...

21 CFR 1302.03 - Symbol required; exceptions.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Symbol required; exceptions. 1302.03 Section 1302... REQUIREMENTS FOR CONTROLLED SUBSTANCES § 1302.03 Symbol required; exceptions. (a) Each commercial container of... § 1308.31 of this chapter) shall have printed on the label the symbol designating the schedule in which...

40 CFR 60.581 - Definitions and symbols.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Definitions and symbols. 60.581 Section... Coating and Printing § 60.581 Definitions and symbols. (a) All terms used in this subpart, not defined... solvent vapors emitted from the flexible vinyl or urethane rotogravure printing line. (b) All symbols used...

32 CFR 310.42 - Reports control symbol.

Science.gov (United States)

2010-07-01

... 32 National Defense 2 2010-07-01 2010-07-01 false Reports control symbol. 310.42 Section 310.42... PROGRAM DOD PRIVACY PROGRAM Reports § 310.42 Reports control symbol. Any report established by this subpart in support of the Privacy Program shall be assigned Report Control Symbol DD-COMP(A)1379. ...

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...

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.)

An Acoustic OFDM System with Symbol-by-Symbol Doppler Compensation for Underwater Communication.

Science.gov (United States)

MinhHai, Tran; Rie, Saotome; Suzuki, Taisaku; Wada, Tomohisa

2016-01-01

We propose an acoustic OFDM system for underwater communication, specifically for vertical link communications such as between a robot in the sea bottom and a mother ship in the surface. The main contributions are (1) estimation of time varying Doppler shift using continual pilots in conjunction with monitoring the drift of Power Delay Profile and (2) symbol-by-symbol Doppler compensation in frequency domain by an ICI matrix representing nonuniform Doppler. In addition, we compare our proposal against a resampling method. Simulation and experimental results confirm that our system outperforms the resampling method when the velocity changes roughly over OFDM symbols. Overall, experimental results taken in Shizuoka, Japan, show our system using 16QAM, and 64QAM achieved a data throughput of 7.5 Kbit/sec with a transmitter moving at maximum 2 m/s, in a complicated trajectory, over 30 m vertically.

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

Recent advances in dental optics - Part II: Experimental tests for a new intraoral scanner

Science.gov (United States)

Logozzo, Silvia; Kilpelä, Ari; Mäkynen, Anssi; Zanetti, Elisabetta M.; Franceschini, Giordano

2014-03-01

The object of this paper is testing the performance of a new device for 3D oral scanning: a two channel PTOF (pulsed time-of-flight) laser scanner, designed for dental and industrial applications in the measurement range of zero to a few centimetres. The application on short distances (0-10 cm) has entailed the improvement of performance parameters such as single shot precision, average precision and walk error up to mm-level and to µm-level respectively.

Optical Character Recognition.

Science.gov (United States)

Converso, L.; Hocek, S.

1990-01-01

This paper describes computer-based optical character recognition (OCR) systems, focusing on their components (the computer, the scanner, the OCR, and the output device); how the systems work; and features to consider in selecting a system. A list of 26 questions to ask to evaluate systems for potential purchase is included. (JDD)

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

Applied cartographic communication: map symbolization for atlases.

Science.gov (United States)

Morrison, J.L.

1984-01-01

A detailed investigation of the symbolization used on general-purpose atlas reference maps. It indicates how theories of cartographic communication can be put into practice. Two major points emerge. First, that a logical scheme can be constructed from existing cartographic research and applied to an analysis of the choice of symbolization on a map. Second, the same structure appears to allow the cartographer to specify symbolization as a part of map design. An introductory review of cartographic communication is followed by an analysis of selected maps' usage of point, area and line symbols, boundaries, text and colour usage.-after Author

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.

Symbol signing design for older drivers

Science.gov (United States)

1997-07-01

This project evaluated the effectiveness of symbol traffic signs for young, middle-aged and elderly drivers. Daytime legibility distance and comprehension of 85 symbols in the Manual on Uniform Traffic Control Devices (MUTCD) were measured. Legibilit...

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

What’s the problem with symbolic religious establishment? The alienation and symbolic equality accounts

DEFF Research Database (Denmark)

Lægaard, Sune

2017-01-01

In this chapter I examine two possible reasons, which are prominent but often not systematically discussed in the literature, for thinking even purely symbolic establishment problematic. These are considerations of alienation and symbolic equality. I am only concerned with ways in which establish...... establishment might be normatively problematic even if it does not infringe on religious freedom and does not involve material injustices in other respects....

Designing and evaluating symbols for electronic displays of navigation information : symbol stereotypes and symbol-feature rules

Science.gov (United States)

2005-09-30

There is currently no common symbology standard for the electronic display of navigation information. The wide range of display technology and the different functions these displays support makes it difficult to design symbols that are easily recogni...

An Acoustic OFDM System with Symbol-by-Symbol Doppler Compensation for Underwater Communication

Directory of Open Access Journals (Sweden)

Tran MinhHai

2016-01-01

Full Text Available We propose an acoustic OFDM system for underwater communication, specifically for vertical link communications such as between a robot in the sea bottom and a mother ship in the surface. The main contributions are (1 estimation of time varying Doppler shift using continual pilots in conjunction with monitoring the drift of Power Delay Profile and (2 symbol-by-symbol Doppler compensation in frequency domain by an ICI matrix representing nonuniform Doppler. In addition, we compare our proposal against a resampling method. Simulation and experimental results confirm that our system outperforms the resampling method when the velocity changes roughly over OFDM symbols. Overall, experimental results taken in Shizuoka, Japan, show our system using 16QAM, and 64QAM achieved a data throughput of 7.5 Kbit/sec with a transmitter moving at maximum 2 m/s, in a complicated trajectory, over 30 m vertically.

An Acoustic OFDM System with Symbol-by-Symbol Doppler Compensation for Underwater Communication

Science.gov (United States)

MinhHai, Tran; Rie, Saotome; Suzuki, Taisaku; Wada, Tomohisa

2016-01-01

We propose an acoustic OFDM system for underwater communication, specifically for vertical link communications such as between a robot in the sea bottom and a mother ship in the surface. The main contributions are (1) estimation of time varying Doppler shift using continual pilots in conjunction with monitoring the drift of Power Delay Profile and (2) symbol-by-symbol Doppler compensation in frequency domain by an ICI matrix representing nonuniform Doppler. In addition, we compare our proposal against a resampling method. Simulation and experimental results confirm that our system outperforms the resampling method when the velocity changes roughly over OFDM symbols. Overall, experimental results taken in Shizuoka, Japan, show our system using 16QAM, and 64QAM achieved a data throughput of 7.5 Kbit/sec with a transmitter moving at maximum 2 m/s, in a complicated trajectory, over 30 m vertically. PMID:27057558

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...

Intuitiveness of Symbol Features for Air Traffic Management

Science.gov (United States)

Ngo, Mary Kim; Vu, Kim-Phuong L.; Thorpe, Elaine; Battiste, Vernol; Strybel, Thomas Z.

2012-01-01

We present the results of two online surveys asking participants to indicate what type of air traffic information might be conveyed by a number of symbols and symbol features (color, fill, text, and shape). The results of this initial study suggest that the well-developed concepts of ownership, altitude, and trajectory are readily associated with certain symbol features, while the relatively novel concept of equipage was not clearly associated with any specific symbol feature.

Parties, rituals and symbolisms in schools

Directory of Open Access Journals (Sweden)

Ana Cecilia Valencia Aguirre

2015-07-01

Full Text Available This paper aims at analyzing school parties from interaction spaces and principals’ narratives in six schools in the state of Jalisco. A party is a ritual where participants share symbols related to imaginary –hence the importance of conducting an analysis for understanding institutions as a symbolic framework. A core argument is that established actors are configured from symbolic practices in the institutional space (schools. The repetition of these practices awash with symbolism leads to daily rituals or micro rituals that are ratified in institutions. Methodologically, interviews and non-participant observation in school interaction spaces were used. Based on the findings, it may be stated that the nuclear family, rooted in the Christian image in which authority is a central point, becomes a fundamental factor in shaping institutional life as well as the imaginary linked to school parties.

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

Symbol synchronization and sampling frequency synchronization techniques in real-time DDO-OFDM systems

Science.gov (United States)

Chen, Ming; He, Jing; Cao, Zizheng; Tang, Jin; Chen, Lin; Wu, Xian

2014-09-01

In this paper, we propose and experimentally demonstrate a symbol synchronization and sampling frequency synchronization techniques in real-time direct-detection optical orthogonal frequency division multiplexing (DDO-OFDM) system, over 100-km standard single mode fiber (SSMF) using a cost-effective directly modulated distributed feedback (DFB) laser. The experiment results show that the proposed symbol synchronization based on training sequence (TS) has a low complexity and high accuracy even at a sampling frequency offset (SFO) of 5000-ppm. Meanwhile, the proposed pilot-assisted sampling frequency synchronization between digital-to-analog converter (DAC) and analog-to-digital converter (ADC) is capable of estimating SFOs with an accuracy of technique can also compensate SFO effects within a small residual SFO caused by deviation of SFO estimation and low-precision or unstable clock source. The two synchronization techniques are suitable for high-speed DDO-OFDM transmission systems.

Symbol phantoms

International Nuclear Information System (INIS)

Yamaguchi, Hiroshi; Hongo, Syozo; Takeshita, Hiroshi

1990-01-01

We have developed Japanese phantoms in two procedures for computation of organ doses exposed to internal and/or external radiation sources. One method is to make mathematical phantoms on the basis of ORNL mathematical phantoms. Parameters to specify organs of Japanese mathematical phantom are determined by interpolations of the ORNL data, which define the organs of Caucasian males and females of various ages, i.e. new born, 1, 5, 10, 15 years and adult, with survey data for Japanese physiques. Another procedure is to build 'symbol phantoms' for the Japanese public. The concept and its method of the symbol phantom enables us to make a phantom for an individual when we have all of his transversal section images obtained by a medical imaging device like MRI, and thus we may achieve more realistic phantoms for Japanese public than the mathematical phantoms. Both studies are in progress in NIRS. (author)

Multiple-Symbol, Partially Coherent Detection of MPSK

Science.gov (United States)

Simon, Marvin K.; Divsalar, Dariush

1994-01-01

Proposed method of reception of multiple-phase-shift-keyed (MPSK) radio signals involves multiple-symbol, partially coherent detection. Instead of attempting to determine phase of transmitted signal during each symbol period as in coherent detection, receiver acquires signal data during multiple-symbol observation interval, then produces maximum-likelihood-sequence estimate of phases transmitted during interval. Combination of coherent-reception and incoherent-reception decision rules are used.

Effects of background color and symbol arrangement cues on construction of multi-symbol messages by young children without disabilities: implications for aided AAC design.

Science.gov (United States)

Thistle, Jennifer J; Wilkinson, Krista

2017-09-01

Children whose speech does not meet their communication needs often benefit from augmentative and alternative communication (AAC). The design of an AAC display may influence the child's ability to communicate effectively. The current study examined how symbol background color cues and symbol arrangement affected construction of multi-symbol messages using line-drawing symbols, by young children with typical development. Participants (N = 52) heard a spoken phrase matching a photograph and selected line drawings within a 4 × 4 array. Friedman two-way ANOVAs evaluated speed and accuracy of multi-symbol message construction under four conditions in which the background color and arrangement of symbols was manipulated. Participants demonstrated significantly faster response times when symbols were arranged by word-class category compared to no symbol arrangement. The majority of children responded faster when symbols had white backgrounds, but this effect failed to reach statistical significance. This study provides preliminary evidence suggesting the importance of symbol arrangement for young children. The findings highlight the need for caution when incorporating background color on displays for young children. Future research is needed to examine the effect of visual cues on children who use AAC and consider additional factors that could influence efficacy of symbol arrangement and background color use.

The Scientific Import of Symbols in Human Knowledge | Agbanusi ...

African Journals Online (AJOL)

Symbolism, being the use of symbols to represent ideas, it is generally believed that symbolism is restricted to the Arts, especially logic and literature. However, recent developments have shown that symbolism can be an interesting companion and, in fact, a necessary complement, of science. This work X-Rays the ...

Use of language in symbolic play of toddlers

OpenAIRE

Knap, Petra

2015-01-01

The purpose of the thesis is to determine which materials encourage language development during symbolic play, how often do children in the first age group engage in symbolic play, and how can the teacher influence speech development during this activity. The theoretical part defines play, focusing on symbolic play. It also describes the role of the preschool teacher during play and explores the speech of younger children during symbolic play. The empirical part of the thesis examines whic...

The Polish LGBT movement : symbolic conflict and stigma

OpenAIRE

Mossakowski, Tomek

2011-01-01

This thesis examines the political activities of the LGBT movement in Poland as it seeks to increase its position on the socio-political landscape and ultimately rid itself of stigma. Using ethnographic data collection at a non-governmental organisation in Warsaw, it discusses the use of symbols and the accumulation of what Bourdieu called symbolic capital. It draws heavily on the theory of Harrison's symbolic conflict and Schwimmer's notions of symbolic and direct competition, while bringing...

Symbolism in European Integration

DEFF Research Database (Denmark)

Manners, Ian

2011-01-01

Ernst Haas observed over fifty years ago that ‘United Europe' is a resilient, adaptable, unifying, and yet unspecified symbol'. It is precisely this adaptability and ambiguity that has ensures the continuing importance of European studies as a means of understanding ‘the remarkable social...... of social transformation involved' (Calhoun 2003: 18). This article will consider the role of symbolism in European integration as part of answering Craig Calhoun's call for a means of transcending specific regimes of analysis in order to advance European studies....

Optical CT evaluation on normoxic polymer gel dosimeter

International Nuclear Information System (INIS)

Samuel, E. James Jebaseelan

2013-01-01

Optical computed tomography has been shown to be a potentially useful imaging tool for the radiation therapy physicists. In radiation therapy, researchers have used optical CT for the readout of 3D dosimeters. The purpose of this paper is to explicate the initial evaluation of a newly fabricated laser CT scanner for '3D gel dosimetry' which works in the first generation principle. The normoxic PAGAT (Polyacrylamide Gelatin and Tetrakis) gel is used as a dosimeter for this analysis. When laser passes through this gel phantom, absorption and scattering of photon take place. The optical attenuation coefficient of the laser can be obtained by measuring its intensity after passing through the gel by a sensor.The scanner motion is controlled by the program written in Microsoft Visual C++. Reconstruction and data analysis on the irradiated gel phantom is performed by suitable algorithm using Matlab software. (author)

SYMBOL LEVEL DECODING FOR DUO-BINARY TURBO CODES

Directory of Open Access Journals (Sweden)

Yogesh Beeharry

2017-05-01

Full Text Available This paper investigates the performance of three different symbol level decoding algorithms for Duo-Binary Turbo codes. Explicit details of the computations involved in the three decoding techniques, and a computational complexity analysis are given. Simulation results with different couple lengths, code-rates, and QPSK modulation reveal that the symbol level decoding with bit-level information outperforms the symbol level decoding by 0.1 dB on average in the error floor region. Moreover, a complexity analysis reveals that symbol level decoding with bit-level information reduces the decoding complexity by 19.6 % in terms of the total number of computations required for each half-iteration as compared to symbol level decoding.

Symbol lock detection implemented with nonoverlapping integration intervals

Science.gov (United States)

Shihabi, Mazen M. (Inventor); Hinedi, Sami M. (Inventor); Shah, Biren N. (Inventor)

1995-01-01

A symbol lock detector is introduced for an incoming coherent digital communication signal which utilizes a subcarrier modulated with binary symbol data, d(sub k), and known symbol interval T by integrating binary values of the signal over nonoverlapping first and second intervals selected to be T/2, delaying the first integral an interval T/2, and either summing or multiplying the second integral with the first one that preceded it to form a value X(sub k). That value is then averaged over a number M of symbol intervals to produce a static value Y. A symbol lock decision can then be made when the static value Y exceeds a threshold level delta.

7 CFR 97.900 - Form of official identification symbol.

Science.gov (United States)

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Form of official identification symbol. 97.900 Section... symbol. The symbol set forth in Figure 1, containing the words “Plant Variety Protection Office” and “U.S. Department of Agriculture,” shall be the official identification symbol of the Plant Variety Protection...

An integrated instrumental setup for the combination of atomic force microscopy with optical spectroscopy.

Science.gov (United States)

Owen, R J; Heyes, C D; Knebel, D; Röcker, C; Nienhaus, G U

2006-07-01

In recent years, the study of single biomolecules using fluorescence microscopy and atomic force microscopy (AFM) techniques has resulted in a plethora of new information regarding the physics underlying these complex biological systems. It is especially advantageous to be able to measure the optical, topographical, and mechanical properties of single molecules simultaneously. Here an AFM is used that is especially designed for integration with an inverted optical microscope and that has a near-infrared light source (850 nm) to eliminate interference between the optical experiment and the AFM operation. The Tip Assisted Optics (TAO) system consists of an additional 100 x 100-microm(2) X-Y scanner for the sample, which can be independently and simultaneously used with the AFM scanner. This allows the offset to be removed between the confocal optical image obtained with the sample scanner and the simultaneously acquired AFM topography image. The tip can be positioned exactly into the optical focus while the user can still navigate within the AFM image for imaging or manipulation of the sample. Thus the tip-enhancement effect can be maximized and it becomes possible to perform single molecule manipulation experiments within the focus of a confocal optical image. Here this is applied to simultaneous measurement of single quantum dot fluorescence and topography with high spatial resolution. (c) 2006 Wiley Periodicals, Inc.

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...

Visual Symbolism in Contemporary Theatre Directing in Nigeria ...

African Journals Online (AJOL)

This difference is cropped from the director's perception, conception, imaginative and creative impetus. Visual symbolism in the theatre as a medium traverse forms, textures, symbols, lines, lighting, circles and balance in creating an everlasting theatre experience. Visual symbolism is influenced by style, concept, forms, ...

Assessment of symbolic function in Mexican preschool children

Directory of Open Access Journals (Sweden)

N. R. Jiménez Barreto

2013-04-01

Full Text Available Development of symbolic function is an important psychological formation of pre-school age and reflects the possibility of the child to use signs and symbols in a conscious way. Assessment of symbolic function can be used as one of preparation for school indicators. The objective of the present study is to characterize the level of symbolic function development in Mexican pre-school children. 59 children were included in the study. The ages of the children were between 5 and 6 years and all of them belonged to sub-urban pre-school institution. All 59 children participated in this study for the first time. Our assessment consisted of specific tasks with symbolic means on materialized, perceptive and verbal levels. Each child was tested individually. Results showed an insufficient development of the symbolic function in all evaluated children. More than 78% of the children showed difficulties during performance in the tasks of assessment; their drawings were undifferentiated and had few essential characteristics. The obtained results show the necessity to implement developmental strategies in order to guarantee the formation of the ability of constant conscious sage of symbolic means at the end of pre-school age.

Circular blurred shape model for multiclass symbol recognition.

Science.gov (United States)

Escalera, Sergio; Fornés, Alicia; Pujol, Oriol; Lladós, Josep; Radeva, Petia

2011-04-01

In this paper, we propose a circular blurred shape model descriptor to deal with the problem of symbol detection and classification as a particular case of object recognition. The feature extraction is performed by capturing the spatial arrangement of significant object characteristics in a correlogram structure. The shape information from objects is shared among correlogram regions, where a prior blurring degree defines the level of distortion allowed in the symbol, making the descriptor tolerant to irregular deformations. Moreover, the descriptor is rotation invariant by definition. We validate the effectiveness of the proposed descriptor in both the multiclass symbol recognition and symbol detection domains. In order to perform the symbol detection, the descriptors are learned using a cascade of classifiers. In the case of multiclass categorization, the new feature space is learned using a set of binary classifiers which are embedded in an error-correcting output code design. The results over four symbol data sets show the significant improvements of the proposed descriptor compared to the state-of-the-art descriptors. In particular, the results are even more significant in those cases where the symbols suffer from elastic deformations.

Matter and symbols of the artificial

Energy Technology Data Exchange (ETDEWEB)

Rocha, L.M.

1998-08-01

The study of complex systems should be based on a systems-theoretic framework which requires both self-organizing and symbolic dimensions. An inclusive framework based on the notion of semiotics is advanced to build models capable of representing, as well as evolving in their environments, with implications for Artificial Life. Such undertaking is pursued by discussing the ways in which symbol and matter are irreducibly intertwined in evolutionary systems. The problem is thus phrased in terms of the semiotic categories of syntax, semantics, and pragmatics. With this semiotic view of matter and symbols the requirements of semiotic closure are expressed in models with both self-organizing and symbolic characteristics. Situated action and recent developments in the evolution of cellular automata rules to solve non-trivial tasks are discussed in this context. Finally, indirect encoding schemes for genetic algorithms are developed which follow the semiotic framework here proposed.

Symbolic math for computation of radiation shielding

International Nuclear Information System (INIS)

Suman, Vitisha; Datta, D.; Sarkar, P.K.; Kushwaha, H.S.

2010-01-01

Radiation transport calculations for shielding studies in the field of accelerator technology often involve intensive numerical computations. Traditionally, radiation transport equation is solved using finite difference scheme or advanced finite element method with respect to specific initial and boundary conditions suitable for the geometry of the problem. All these computations need CPU intensive computer codes for accurate calculation of scalar and angular fluxes. Computation using symbols of the analytical expression representing the transport equation as objects is an enhanced numerical technique in which the computation is completely algorithm and data oriented. Algorithm on the basis of symbolic math architecture is developed using Symbolic math toolbox of MATLAB software. Present paper describes the symbolic math algorithm and its application as a case study in which shielding calculation of rectangular slab geometry is studied for a line source of specific activity. Study of application of symbolic math in this domain evolves a new paradigm compared to the existing computer code such as DORT. (author)

Analysing the Effectiveness of the Personality Symbols/Icons

OpenAIRE

Halim, İpek

2012-01-01

Personality symbol can cover all the identifications of the brand. It can be the face or the soul of the company. Their effect on the brand image is huge. The research focuses on calculating the roles and effectives of the personality symbols. It aims to bring in suggestions for developing a successful personality symbols and lists advantages and disadvantages of different types of personality symbols. It does a detailed copy testing. Apart from conducting focus groups to analyse how the targ...

Symbol Synchronization for Diffusion-Based Molecular Communications.

Science.gov (United States)

Jamali, Vahid; Ahmadzadeh, Arman; Schober, Robert

2017-12-01

Symbol synchronization refers to the estimation of the start of a symbol interval and is needed for reliable detection. In this paper, we develop several symbol synchronization schemes for molecular communication (MC) systems where we consider some practical challenges, which have not been addressed in the literature yet. In particular, we take into account that in MC systems, the transmitter may not be equipped with an internal clock and may not be able to emit molecules with a fixed release frequency. Such restrictions hold for practical nanotransmitters, e.g., modified cells, where the lengths of the symbol intervals may vary due to the inherent randomness in the availability of food and energy for molecule generation, the process for molecule production, and the release process. To address this issue, we develop two synchronization-detection frameworks which both employ two types of molecule. In the first framework, one type of molecule is used for symbol synchronization and the other one is used for data detection, whereas in the second framework, both types of molecule are used for joint symbol synchronization and data detection. For both frameworks, we first derive the optimal maximum likelihood (ML) symbol synchronization schemes as performance upper bounds. Since ML synchronization entails high complexity, for each framework, we also propose three low-complexity suboptimal schemes, namely a linear filter-based scheme, a peak observation-based scheme, and a threshold-trigger scheme, which are suitable for MC systems with limited computational capabilities. Furthermore, we study the relative complexity and the constraints associated with the proposed schemes and the impact of the insertion and deletion errors that arise due to imperfect synchronization. Our simulation results reveal the effectiveness of the proposed synchronization schemes and suggest that the end-to-end performance of MC systems significantly depends on the accuracy of the symbol

Examining the Nexus between Grounded Theory and Symbolic Interactionism

Directory of Open Access Journals (Sweden)

P. Jane Milliken RN, PhD

2012-12-01

Full Text Available Grounded theory is inherently symbolic interactionist; however, not all grounded theory researchers appreciate its importance or benefit from its influence. Elsewhere, we have written about the intrinsic relationship between grounded theory and symbolic interactionism, highlighting the silent, fundamental contribution of symbolic interactionism to the methodology. At the same time, there are significant insights to be had by bringing a conscious awareness of the philosophy of symbolic interactionism to grounded theory research. In this article we discuss the symbolic interactionist concepts of mind, self, and society, and their applicability in grounded theorizing. Our purpose is to highlight foundational concepts of symbolic interactionism and their centrality in the processes of conducting grounded theory research.

Multi-core symbolic bisimulation minimisation

OpenAIRE

Dijk, Tom van; Pol, Jaco van de

2017-01-01

We introduce parallel symbolic algorithms for bisimulation minimisation, to combat the combinatorial state space explosion along three different paths. Bisimulation minimisation reduces a transition system to the smallest system with equivalent behaviour. We consider strong and branching bisimilarity for interactive Markov chains, which combine labelled transition systems and continuous-time Markov chains. Large state spaces can be represented concisely by symbolic techniques, based on binary...

Sound-symbolism boosts novel word learning

NARCIS (Netherlands)

Lockwood, G.F.; Dingemanse, M.; Hagoort, P.

2016-01-01

The existence of sound-symbolism (or a non-arbitrary link between form and meaning) is well-attested. However, sound-symbolism has mostly been investigated with nonwords in forced choice tasks, neither of which are representative of natural language. This study uses ideophones, which are naturally

Security enhancement of hand geometry scanners using optical blood flow detection

Science.gov (United States)

Crihalmeanu, Musat C.; Jerabek, Mark A.; Meehan, Kathleen

2004-08-01

In today's security conscious society the efficiency of biometric systems has an increasing tendency to replace the classic but less effective keys and passwords. Hand geometry readers are popular biometrics used for acces control and time and attendance applications. One of their weaknesses is vulnerability to spoofing using fake hands (latex, play-doh or dead-hands). The object of this paper is to design a feature to be added to the hand geometry scanner in order to detect vitality in the hand, reducing the possibilities for spoofing. This paper demonstrates how the hand reader was successfully spoofed and shows the implementation of the vitality detection feature through an inexpensive but efficient electronic design. The method used for detection is photo-plethysmography. The Reflectance Sensor built is of original conception. After amplifying, filtering and processing the sensor's signal, a message is shown via an LCD display, concerning the liveness of the hand and the pulse rate.

Symbolic dynamics of the Lorenz equations

International Nuclear Information System (INIS)

Fang Hai-ping; Hao Bailin.

1994-07-01

The Lorenz equations are investigated in a wide range of parameters by using the method of symbolic dynamics. First, the systematics of stable periodic orbits in the Lorenz equations is compared with that of the one-dimensional cubic map, which shares the same discrete symmetry with the Lorenz model. The systematics is then ''corrected'' in such a way as to encompass all the known periodic windows of the Lorenz equations with only one exception. Second, in order to justify the above approach and to understand the exceptions, another 1D map with a discontinuity is extracted from an extension of the geometric Lorenz attractor and its symbolic dynamics is constructed. All this has to be done in light of symbolic dynamics of two-dimensional maps. Finally, symbolic dynamics for the actual Poincare return map of the Lorenz equations is constructed in a heuristic way. New periodic windows of the Lorenz equations and their parameters can be predicted from this symbolic dynamics in combination with the 1D cubic map. The extended geometric 2D Lorenz map and the 1D antisymmetric map with a discontinuity describe the topological aspects of the Lorenz equations to high accuracy. (author). 44 refs, 17 figs, 8 tabs

Symbolics in control design: prospects and research issues

DEFF Research Database (Denmark)

Christensen, Anders

1994-01-01

The symbolic processor is targeted as a novel basic service in computer aided control system design. Basic symbolic tools are exemplified. A design process model is formulated for control design, with subsets manipulator, tools, target and goals. It is argued, that symbolic processing will give...... substantial contributions to future design environments, as it provides flexibility of representation not possible with traditional numerics. Based on the design process, views on research issues in the incorporation of symbolic processing into traditional numerical design environments are given...

Mythology, Weltanschauung, symbolic universe and states of consciousness

Directory of Open Access Journals (Sweden)

Gert Malan

2016-07-01

Full Text Available This article investigates whether different religious (mythological worldviews can be described as alternative and altered states of consciousness (ASCs. Differences between conscious and unconscious motivations for behaviour are discussed before looking at ASCs, Weltanschauung and symbolic universes. Mythology can be described both as Weltanschauung and symbolic universe, functioning on all levels of consciousness. Different Weltanschauungen constitute alternative states of consciousness. Compared to secular worldviews, religious worldviews may be described as ASCs. Thanks to our globalised modern societies, the issue is even more complex, as alternate modernities lead to a symbolic multiverse, with individuals living in a social multiverse. Keyowrds: mythology; Weltanschauung; worldview; symbolic universe; states of consciousness; altered states of consciousness; alternative states of consciousness; symbolic multiverse; social multiverse

Tunable micro-optics

CERN Document Server

Duppé, Claudia

2015-01-01

Presenting state-of-the-art research into the dynamic field of tunable micro-optics, this is the first book to provide a comprehensive survey covering a varied range of topics including novel materials, actuation concepts and new imaging systems in optics. Internationally renowned researchers present a diverse range of chapters on cutting-edge materials, devices and subsystems, including soft matter, artificial muscles, tunable lenses and apertures, photonic crystals, and complete tunable imagers. Special contributions also provide in-depth treatment of micro-optical characterisation, scanners, and the use of natural eye models as inspiration for new concepts in advanced optics. With applications extending from medical diagnosis to fibre telecommunications, Tunable Micro-optics equips readers with a solid understanding of the broader technical context through its interdisciplinary approach to the realisation of new types of optical systems. This is an essential resource for engineers in industry and academia,...

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.

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

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.

Optical Verification Laboratory Demonstration System for High Security Identification Cards

Science.gov (United States)

Javidi, Bahram

1997-01-01

Document fraud including unauthorized duplication of identification cards and credit cards is a serious problem facing the government, banks, businesses, and consumers. In addition, counterfeit products such as computer chips, and compact discs, are arriving on our shores in great numbers. With the rapid advances in computers, CCD technology, image processing hardware and software, printers, scanners, and copiers, it is becoming increasingly easy to reproduce pictures, logos, symbols, paper currency, or patterns. These problems have stimulated an interest in research, development and publications in security technology. Some ID cards, credit cards and passports currently use holograms as a security measure to thwart copying. The holograms are inspected by the human eye. In theory, the hologram cannot be reproduced by an unauthorized person using commercially-available optical components; in practice, however, technology has advanced to the point where the holographic image can be acquired from a credit card-photographed or captured with by a CCD camera-and a new hologram synthesized using commercially-available optical components or hologram-producing equipment. Therefore, a pattern that can be read by a conventional light source and a CCD camera can be reproduced. An optical security and anti-copying device that provides significant security improvements over existing security technology was demonstrated. The system can be applied for security verification of credit cards, passports, and other IDs so that they cannot easily be reproduced. We have used a new scheme of complex phase/amplitude patterns that cannot be seen and cannot be copied by an intensity-sensitive detector such as a CCD camera. A random phase mask is bonded to a primary identification pattern which could also be phase encoded. The pattern could be a fingerprint, a picture of a face, or a signature. The proposed optical processing device is designed to identify both the random phase mask and the

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

Handwriting generates variable visual input to facilitate symbol learning

Science.gov (United States)

Li, Julia X.; James, Karin H.

2015-01-01

Recent research has demonstrated that handwriting practice facilitates letter categorization in young children. The present experiments investigated why handwriting practice facilitates visual categorization by comparing two hypotheses: That handwriting exerts its facilitative effect because of the visual-motor production of forms, resulting in a direct link between motor and perceptual systems, or because handwriting produces variable visual instances of a named category in the environment that then changes neural systems. We addressed these issues by measuring performance of 5 year-old children on a categorization task involving novel, Greek symbols across 6 different types of learning conditions: three involving visual-motor practice (copying typed symbols independently, tracing typed symbols, tracing handwritten symbols) and three involving visual-auditory practice (seeing and saying typed symbols of a single typed font, of variable typed fonts, and of handwritten examples). We could therefore compare visual-motor production with visual perception both of variable and similar forms. Comparisons across the six conditions (N=72) demonstrated that all conditions that involved studying highly variable instances of a symbol facilitated symbol categorization relative to conditions where similar instances of a symbol were learned, regardless of visual-motor production. Therefore, learning perceptually variable instances of a category enhanced performance, suggesting that handwriting facilitates symbol understanding by virtue of its environmental output: supporting the notion of developmental change though brain-body-environment interactions. PMID:26726913

CHRISTIAN SYMBOLISM IN FYODOR DOSTOEVSKY'S NOVEL "THE POSSESSED" ("DEMONS"

Directory of Open Access Journals (Sweden)

Sergei Leonidovich Sharakov

2013-11-01

Full Text Available The article raises a question of Christian symbolism in Fyodor Dostoevsky’s novel The Possessed (Demons. The introductory part identifies the purpose of a symbol in Christian poetics through the parallel with ancient symbolism. The author makes a conclusion that the functional role of a symbol in the ancient world and Christian tradition is different. Therefore, the ancient symbol involves a number of interrelated categories, such as fate, intuition or conjecture, inspiration, and predictions. Christian symbolism is based on the idea of redemption and moral innocence. Methodologically, the article is based on a cultural and historical approach, as well as on the comparative academic tradition. The overview of Dostoyevsky’s pre-materials for The Possessed (Demons enables us to suggest the use of Christian symbolism in this novel. Hence, the objective of the study is to investigate a composition of images and symbols in this piece of writing, with a special focus on the image of a chronicler since the storyline of the novel is developed through his perception. We make a supposition that there are several levels of Gospel perception in the artistic vision or consciousness of the chronicler, that form the basis of the symbolical composition of the novel. The article sequentially examines the examples of Christian symbolism, including the connection of ideas, characters and storylines of the novel with the Gospel. Then it gives evidence and reasons for the thesis that the Gospel gives the characters of the novel the grounds for shaping their destiny.

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

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)

Examining the Nexus between Grounded Theory and Symbolic Interactionism

OpenAIRE

P. Jane Milliken RN, PhD; Rita Schreiber RN, DNS

2012-01-01

Grounded theory is inherently symbolic interactionist; however, not all grounded theory researchers appreciate its importance or benefit from its influence. Elsewhere, we have written about the intrinsic relationship between grounded theory and symbolic interactionism, highlighting the silent, fundamental contribution of symbolic interactionism to the methodology. At the same time, there are significant insights to be had by bringing a conscious awareness of the philosophy of symbolic interac...

Exploring the Development of Symbolic Function of Consciousness: A Technique

Directory of Open Access Journals (Sweden)

Polyakov A.M.,

2016-07-01

Full Text Available This article describes studying method which developed the symbolic function mind. It is defined as a functional unit providing the solution of problems by understanding and expression of the reality of the subject-subject relationship using symbols. The symbol understood as a cultural form of presen- tation of subjective reality, mediating the relationship and interaction between two or more subjects. The symbol consists of sense-perception of form and meaning, expressing a subjective reality. The structure of the symbolic function includes the following components: generation and implementation plan, the transformation of symbolic forms, the awareness of the antinomic character, character interpretation. Investigation techiques was developed in accordance with the principles of construction of experimental-genetic method. Empirical criteria for evaluating the level of its development was based on the structure of the symbolic function, and developed a system of assistance for the realization of symbolic meaning. The method allows determine the dynamics and conditions for the development of the symbolic function, its genetic makeup, as well as the form and content of cooperation with con- temporaries.

The history and principles of optical computed tomography for scanning 3-D radiation dosimeters: 2008 update

Energy Technology Data Exchange (ETDEWEB)

Doran, Simon J [CRUK Clinical Magnetic Resonance Research Group, Institute of Cancer Research, Sutton, Surrey (United Kingdom); Department of Physics, University of Surrey, Surrey (United Kingdom)], E-mail: Simon.Doran@icr.ac.uk

2009-05-01

The current status of optical CT for 3-D radiation dosimetry is reviewed. The technique is first placed in its historical context, pointing out the relationship with other methods of optical imaging and showing how optical-CT has emerged independently in several different fields and under different names. The theoretical background of the method is described briefly and this provides the foundation for an explanation of the different types of scanner. The relative advantages and disadvantages of instruments based on scanned lasers and pixelated (area) detectors are presented. The latest generation of 'fast laser scanners' is described and the review is concluded with a discussion of the different radiation-sensitive materials used as samples in optical CT.

The Symbolic Meaning of Legal Subjectivity

NARCIS (Netherlands)

Pessers, D.; van Klink, B.; van Beers, B.; Poort, L.

2016-01-01

The legitimacy of the law is not to be found, as is often claimed, in procedural justice, but in the core function of the law: the symbolic insertion of every new generation into the community of legal subjects. This symbolic function is most ambitiously expressed in the Universal Declaration of

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

The mathematica guidebook for symbolics

CERN Document Server

Trott, Michael

2006-01-01

Mathematica is today's most advanced technical computing system. It features a rich programming environment, two-and three-dimensional graphics capabilities and hundreds of sophisticated, powerful programming and mathematical functions using state-of-the-art algorithms. Combined with a user-friendly interface, and a complete mathematical typesetting system, Mathematica offers an intuitive easy-to-handle environment of great power and utility. "The Mathematica GuideBook for Symbolics" (code and text fully tailored for Mathematica 5.1) deals with Mathematica's symbolic mathematical capabilities. Structural and mathematical operations on single and systems of polynomials are fundamental to many symbolic calculations and they are covered in considerable detail. The solution of equations and differential equations, as well as the classical calculus operations (differentiation, integration, summation, series expansion, limits) are exhaustively treated. Generalized functions and their uses are discussed. In addition...

Engineering Evaluation and Assessment (EE and A) Report for the Symbolic and Sub-symbolic Robotics Intelligence Control System (SS-RICS)

Science.gov (United States)

2018-04-01

ARL-TR-8352 ● APR 2018 US Army Research Laboratory Engineering Evaluation and Assessment (EE&A) Report for the Symbolic and Sub...APR 2018 US Army Research Laboratory Engineering Evaluation and Assessment (EE&A) Report for the Symbolic and Sub-symbolic Robotics...Intelligence Control System (SS-RICS) by Troy Dale Kelley and Eric Avery Human Research and Engineering Directorate, ARL Sean McGhee STG Inc

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.

Fiber optic coherent laser radar 3D vision system

International Nuclear Information System (INIS)

Clark, R.B.; Gallman, P.G.; Slotwinski, A.R.; Wagner, K.; Weaver, S.; Xu, Jieping

1996-01-01

This CLVS will provide a substantial advance in high speed computer vision performance to support robotic Environmental Management (EM) operations. This 3D system employs a compact fiber optic based scanner and operator at a 128 x 128 pixel frame at one frame per second with a range resolution of 1 mm over its 1.5 meter working range. Using acousto-optic deflectors, the scanner is completely randomly addressable. This can provide live 3D monitoring for situations where it is necessary to update once per second. This can be used for decontamination and decommissioning operations in which robotic systems are altering the scene such as in waste removal, surface scarafacing, or equipment disassembly and removal. The fiber- optic coherent laser radar based system is immune to variations in lighting, color, or surface shading, which have plagued the reliability of existing 3D vision systems, while providing substantially superior range resolution

Symbolic computer vector analysis

Science.gov (United States)

Stoutemyer, D. R.

1977-01-01

A MACSYMA program is described which performs symbolic vector algebra and vector calculus. The program can combine and simplify symbolic expressions including dot products and cross products, together with the gradient, divergence, curl, and Laplacian operators. The distribution of these operators over sums or products is under user control, as are various other expansions, including expansion into components in any specific orthogonal coordinate system. There is also a capability for deriving the scalar or vector potential of a vector field. Examples include derivation of the partial differential equations describing fluid flow and magnetohydrodynamics, for 12 different classic orthogonal curvilinear coordinate systems.

JINGLE: THE SOUNDING SYMBOL

Directory of Open Access Journals (Sweden)

Bysko Maxim V.

2013-12-01

Full Text Available The article considers the role of jingles in the industrial era, from the occurrence of the regular radio broadcasting, sound films and television up of modern video games, audio and video podcasts, online broadcasts, and mobile communications. Jingles are researched from the point of view of the theory of symbols: the forward motion is detected in the process of development of jingles from the social symbols (radio callsigns to the individual signs-images (ringtones. The role of technical progress in the formation of jingles as important cultural audio elements of modern digital civilization.

Information decomposition method to analyze symbolical sequences

International Nuclear Information System (INIS)

Korotkov, E.V.; Korotkova, M.A.; Kudryashov, N.A.

2003-01-01

The information decomposition (ID) method to analyze symbolical sequences is presented. This method allows us to reveal a latent periodicity of any symbolical sequence. The ID method is shown to have advantages in comparison with application of the Fourier transformation, the wavelet transform and the dynamic programming method to look for latent periodicity. Examples of the latent periods for poetic texts, DNA sequences and amino acids are presented. Possible origin of a latent periodicity for different symbolical sequences is discussed

The Rhetoric of Disenchantment through Symbolism

Science.gov (United States)

Munyangeyo, Théophile

2012-01-01

The symbolism of "flowers" has always been a significant part of cultures around the world due to their functional meaning in daily life. From their decorative to their aromatic role, flowers and their symbolic meaning trigger emotions, convey wishes and represent thoughts that can not be explicitly expressed. In this regard, an…

Carrier tracking by smoothing filter improves symbol SNR

Science.gov (United States)

Pomalaza-Raez, Carlos A.; Hurd, William J.

1986-01-01

The potential benefit of using a smoothing filter to estimate carrier phase over use of phase locked loops (PLL) is determined. Numerical results are presented for the performance of three possible configurations of the deep space network advanced receiver. These are residual carrier PLL, sideband aided residual carrier PLL, and finally sideband aiding with a Kalman smoother. The average symbol signal to noise ratio (SNR) after losses due to carrier phase estimation error is computed for different total power SNRs, symbol rates and symbol SNRs. It is found that smoothing is most beneficial for low symbol SNRs and low symbol rates. Smoothing gains up to 0.4 dB over a sideband aided residual carrier PLL, and the combined benefit of smoothing and sideband aiding relative to a residual carrier loop is often in excess of 1 dB.

A practical approach for writer-dependent symbol recognition using a writer-independent symbol recognizer.

Science.gov (United States)

LaViola, Joseph J; Zeleznik, Robert C

2007-11-01

We present a practical technique for using a writer-independent recognition engine to improve the accuracy and speed while reducing the training requirements of a writer-dependent symbol recognizer. Our writer-dependent recognizer uses a set of binary classifiers based on the AdaBoost learning algorithm, one for each possible pairwise symbol comparison. Each classifier consists of a set of weak learners, one of which is based on a writer-independent handwriting recognizer. During online recognition, we also use the n-best list of the writer-independent recognizer to prune the set of possible symbols and thus reduce the number of required binary classifications. In this paper, we describe the geometric and statistical features used in our recognizer and our all-pairs classification algorithm. We also present the results of experiments that quantify the effect incorporating a writer-independent recognition engine into a writer-dependent recognizer has on accuracy, speed, and user training time.

Graphic Symbols as "The Mind on Paper": Links between Children's Interpretive Theory of Mind and Symbol Understanding

Science.gov (United States)

Myers, Lauren J.; Liben, Lynn S.

2012-01-01

Children gradually develop interpretive theory of mind (iToM)--the understanding that different people may interpret identical events or stimuli differently. The present study tested whether more advanced iToM underlies children's recognition that map symbols' meanings must be communicated to others when symbols are iconic (resemble their…

Handwriting generates variable visual output to facilitate symbol learning.

Science.gov (United States)

Li, Julia X; James, Karin H

2016-03-01

Recent research has demonstrated that handwriting practice facilitates letter categorization in young children. The present experiments investigated why handwriting practice facilitates visual categorization by comparing 2 hypotheses: that handwriting exerts its facilitative effect because of the visual-motor production of forms, resulting in a direct link between motor and perceptual systems, or because handwriting produces variable visual instances of a named category in the environment that then changes neural systems. We addressed these issues by measuring performance of 5-year-old children on a categorization task involving novel, Greek symbols across 6 different types of learning conditions: 3 involving visual-motor practice (copying typed symbols independently, tracing typed symbols, tracing handwritten symbols) and 3 involving visual-auditory practice (seeing and saying typed symbols of a single typed font, of variable typed fonts, and of handwritten examples). We could therefore compare visual-motor production with visual perception both of variable and similar forms. Comparisons across the 6 conditions (N = 72) demonstrated that all conditions that involved studying highly variable instances of a symbol facilitated symbol categorization relative to conditions where similar instances of a symbol were learned, regardless of visual-motor production. Therefore, learning perceptually variable instances of a category enhanced performance, suggesting that handwriting facilitates symbol understanding by virtue of its environmental output: supporting the notion of developmental change though brain-body-environment interactions. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

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.)

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...

Television Commercials: Symbols, Myths and Metaphors.

Science.gov (United States)

Feasley, Florence G.

Television commercials convey to the audience through symbols, metaphors, and myths the feelings and emotions deeply rooted in our culture. While commercials on one level are concerned with a representation of the product or service, they are on another level a symbol of a larger meaning: love, family, romance, motherhood, or hero worship. A can…

Symbol-stream Combiner: Description and Demonstration Plans

Science.gov (United States)

Hurd, W. J.; Reder, L. J.; Russell, M. D.

1984-01-01

A system is described and demonstration plans presented for antenna arraying by symbol stream combining. This system is used to enhance the signal-to-noise ratio of a spacecraft signals by combining the detected symbol streams from two or more receiving stations. Symbol stream combining has both cost and performance advantages over other arraying methods. Demonstrations are planned on Voyager 2 both prior to and during Uranus encounter. Operational use is possible for interagency arraying of non-Deep Space Network stations at Neptune encounter.

A Dynamic Perspective on Symbolic Co-branding

DEFF Research Database (Denmark)

von Wallpach, Sylvia; Backhausen, Mia

2016-01-01

brand’s meaning—a challenge that is accentuated when multiple brands form alliances. Focusing on symbolic co-branding, this paper aims to understand how involved brands’ meaning arises from discursive interactions in stakeholder networks (including brand management). A netnographic study in the context...... of lifestyle and fashion blogs provides in-depth insights into the evolvement of two symbolic co-branding processes. The results highlight various stakeholders’ role in and discursive strategies of creating and transferring meaning between involved brands and add unprecedented insights into symbolic co-branding...

Generating and Solving Symbolic Parity Games

Directory of Open Access Journals (Sweden)

Gijs Kant

2014-07-01

Full Text Available We present a new tool for verification of modal mu-calculus formulae for process specifications, based on symbolic parity games. It enhances an existing method, that first encodes the problem to a Parameterised Boolean Equation System (PBES and then instantiates the PBES to a parity game. We improved the translation from specification to PBES to preserve the structure of the specification in the PBES, we extended LTSmin to instantiate PBESs to symbolic parity games, and implemented the recursive parity game solving algorithm by Zielonka for symbolic parity games. We use Multi-valued Decision Diagrams (MDDs to represent sets and relations, thus enabling the tools to deal with very large systems. The transition relation is partitioned based on the structure of the specification, which allows for efficient manipulation of the MDDs. We performed two case studies on modular specifications, that demonstrate that the new method has better time and memory performance than existing PBES based tools and can be faster (but slightly less memory efficient than the symbolic model checker NuSMV.

Combining metric episodes with semantic event concepts within the Symbolic and Sub-Symbolic Robotics Intelligence Control System (SS-RICS)

Science.gov (United States)

Kelley, Troy D.; McGhee, S.

2013-05-01

This paper describes the ongoing development of a robotic control architecture that inspired by computational cognitive architectures from the discipline of cognitive psychology. The Symbolic and Sub-Symbolic Robotics Intelligence Control System (SS-RICS) combines symbolic and sub-symbolic representations of knowledge into a unified control architecture. The new architecture leverages previous work in cognitive architectures, specifically the development of the Adaptive Character of Thought-Rational (ACT-R) and Soar. This paper details current work on learning from episodes or events. The use of episodic memory as a learning mechanism has, until recently, been largely ignored by computational cognitive architectures. This paper details work on metric level episodic memory streams and methods for translating episodes into abstract schemas. The presentation will include research on learning through novelty and self generated feedback mechanisms for autonomous systems.

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.)

Simultaneous acquisition of multislice PET and MR images: initial results with a MR-compatible PET scanner.

Science.gov (United States)

Catana, Ciprian; Wu, Yibao; Judenhofer, Martin S; Qi, Jinyi; Pichler, Bernd J; Cherry, Simon R

2006-12-01

PET and MRI are powerful imaging techniques that are largely complementary in the information they provide. We have designed and built a MR-compatible PET scanner based on avalanche photodiode technology that allows simultaneous acquisition of PET and MR images in small animals. The PET scanner insert uses magnetic field-insensitive, position-sensitive avalanche photodiode (PSAPD) detectors coupled, via short lengths of optical fibers, to arrays of lutetium oxyorthosilicate (LSO) scintillator crystals. The optical fibers are used to minimize electromagnetic interference between the radiofrequency and gradient coils and the PET detector system. The PET detector module components and the complete PET insert assembly are described. PET data were acquired with and without MR sequences running, and detector flood histograms were compared with the ones generated from the data acquired outside the magnet. A uniform MR phantom was also imaged to assess the effect of the PET detector on the MR data acquisition. Simultaneous PET and MRI studies of a mouse were performed ex vivo. PSAPDs can be successfully used to read out large numbers of scintillator crystals coupled through optical fibers with acceptable performance in terms of energy and timing resolution and crystal identification. The PSAPD-LSO detector performs well in the 7-T magnet, and no visible artifacts are detected in the MR images using standard pulse sequences. The first images from the complete system have been successfully acquired and reconstructed, demonstrating that simultaneous PET and MRI studies are feasible and opening up interesting possibilities for dual-modality molecular imaging studies.

Symbol Recognition using Spatial Relations

OpenAIRE

K.C., Santosh; Lamiroy, Bart; Wendling, Laurent

2012-01-01

International audience; In this paper, we present a method for symbol recognition based on the spatio-structural description of a 'vocabulary' of extracted visual elementary parts. It is applied to symbols in electrical wiring diagrams. The method consists of first identifying vocabulary elements into different groups based on their types (e.g., circle, corner ). We then compute spatial relations between the possible pairs of labelled vocabulary types which are further used as a basis for bui...

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.

New Map Symbol System for Disaster Management

Science.gov (United States)

Marinova, Silvia T.

2018-05-01

In the last 10 years Bulgaria was frequently affected by natural and man-made disasters that caused considerable losses. According to the Bulgarian Disaster Management Act (2006) disaster management should be planned at local, regional and national level. Disaster protection is based on plans that include maps such as hazard maps, maps for protection, maps for evacuation planning, etc. Decision-making and cooperation between two or more neighboring municipalities or regions in crisis situation are still rendered difficult because the maps included in the plans differ in scale, colors, map symbols and cartographic design. To improve decision-making process in case of emergency and to reduce the number of human loss and property damages disaster management plans at local and regional level should be supported by detailed thematic maps created in accordance with uniform contents, map symbol system and design. The paper proposes a new symbol system for disaster management that includes a four level hierarchical classification of objects and phenomena according to their type and origin. All objects and phenomena of this classification are divided into five categories: disasters; infrastructure; protection services and infrastructure for protection; affected people and affected infrastructure; operational sites and activities. The symbols of these categories are shown with different background colors and shapes so that they are identifiable. All the symbols have simple but associative design. The new symbol system is used in the design of a series of maps for disaster management at local and regional level.

Efficient Bit-to-Symbol Likelihood Mappings

Science.gov (United States)

Moision, Bruce E.; Nakashima, Michael A.

2010-01-01

This innovation is an efficient algorithm designed to perform bit-to-symbol and symbol-to-bit likelihood mappings that represent a significant portion of the complexity of an error-correction code decoder for high-order constellations. Recent implementation of the algorithm in hardware has yielded an 8- percent reduction in overall area relative to the prior design.

A study of artefacts in simultaneous PET and MR imaging using a prototype MR compatible PET scanner

International Nuclear Information System (INIS)

Slates, R.B.; Farahani, K.; Marsden, P.K.; Taylor, J.; Summers, P.E.; Williams, S.; Beech, J.

1999-01-01

We have assessed the possibility of artefacts that can arise in attempting to perform simultaneous positron emission tomography (PET) and magnetic resonance imaging (MRI) using a small prototype MR compatible PET scanner (McPET). In these experiments, we examine MR images for any major artefacts or loss in image quality due to inhomogeneities in the magnetic field, radiofrequency interference or susceptibility effects caused by operation of the PET system inside the MR scanner. In addition, possible artefacts in the PET images caused by the static and time-varying magnetic fields or radiofrequency interference from the MR system were investigated. Biological tissue and a T 2 -weighted spin echo sequence were used to examine susceptibility artefacts due to components of the McPET scanner (scintillator, optical fibres) situated in the MR field of view. A range of commonly used MR pulse sequences was studied while acquiring PET data to look for possible artefacts in either the PET or MR images. Other than a small loss in signal-to-noise using gradient echo sequences, there was no significant interaction between the two imaging systems. Simultaneous PET and MR imaging of simple phantoms was also carried out in different MR systems with field strengths ranging from 0.2 to 4.7 T. The results of these studies demonstrate that it is possible to acquire PET and MR images simultaneously, without any significant artefacts or loss in image quality, using our prototype MR compatible PET scanner. (author)

Multiple symbol differential detection of uncoded and trellis coded MPSK

Science.gov (United States)

Divsalar, Dariush; Simon, Marvin K.; Shahshahani, Mehrdad

1989-01-01

A differential detection for MPSK, which uses a multiple symbol observation interval, is presented and its performance analyzed and simulated. The technique makes use of maximum-likelihood sequence estimation of the transmitted phases rather than symbol-by-symbol detection as in conventional differential detection. As such the performance of this multiple symbol detection scheme fills the gap between conventional (two-symbol observation) differentially coherent detection of MPSK and ideal coherent of MPSK with differential encoding. The amount of improvement gained over conventional differential detection depends on the number of phases, M, and the number of additional symbol intervals added to the observation. What is particularly interesting is that substantial performance improvement can be obtained for only one or two additional symbol intervals of observation. The analysis and simulation results presented are for uncoded and trellis coded MPSK.

Graphic Symbol Recognition using Graph Based Signature and Bayesian Network Classifier

OpenAIRE

Luqman, Muhammad Muzzamil; Brouard, Thierry; Ramel, Jean-Yves

2010-01-01

We present a new approach for recognition of complex graphic symbols in technical documents. Graphic symbol recognition is a well known challenge in the field of document image analysis and is at heart of most graphic recognition systems. Our method uses structural approach for symbol representation and statistical classifier for symbol recognition. In our system we represent symbols by their graph based signatures: a graphic symbol is vectorized and is converted to an attributed relational g...

Formalising Symbolic Interactionism

NARCIS (Netherlands)

de Nooy, W.

2009-01-01

Symbolic interactionism is generally known as a theory typically linked with a qualitative methodology. Recent developments in quantitative social network analysis, however, can analyze processes theorized within this theoretical tradition. Thick description can be complemented with statistical

SYMBOLIC LANDSCAPE OF CONSCIOUSNESS: MAN BETWEEN REPRESENTATIONALISM, FUNCTIONALISM AND RELATIVISM

Directory of Open Access Journals (Sweden)

P. V. Kretov

2017-12-01

Full Text Available Purpose. The aim of the study is to clarify the changed interpretation of symbol in the context of the ontological turn in cultural anthropology and philosophical anthropology and their correlation with the functioning of the semantic field of culture, and in particular with religious symbols. The paper also considers an epistemological-ideological positions of representationalism, functionalism and relativism with respect to philosopheme of symbol. Methodology. The authors implemented theoretical and conceptual analysis in synchronic and diachronic aspects, the methodology of comparative consideration of the character within the analytical and existential paradigms in the 20th century philosophy. Originality. The work presents the study of correlation between aspect consideration of the nature and specific character in representationalism, functionalism and relativism within the philosophical projects of the cognitive position. The authors substantiated the position of symbol ontologization in the contemporary cultural and philosophical anthropology and the importance of convergence of the symbol concept and philosopheme with the concepts of an object and a thing. They fixed the value of the ontological turn in cultural anthropology for philosophical anthropology. The authors specifically examined the correlation between the declared symbol interpretation, project of object-oriented ontology and the modern philosophy of science. They substantiated ontological concept of symbolic landscape of modern philosophical anthropology, social philosophy and philosophy of mind. The symbol and religious symbolism have the significant importance for human identity, the symbol is considered to be the tool of human’s self-knowledge. Conclusions. The paper outlines the specific character of existence of symbol philosopheme in communicative field of modern man, the social media space, in particular the role of religious symbols for the construction of

7 CFR 91.102 - Form of official identification symbols.

Science.gov (United States)

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Form of official identification symbols. 91.102... LABORATORY TESTING PROGRAMS SERVICES AND GENERAL INFORMATION Designation of Approved Symbols for Identification of Commodities Officially Tested By AMS § 91.102 Form of official identification symbols. Two...

Democracy and the Symbolic Constitution of Society

NARCIS (Netherlands)

Lindahl, H.K.

1998-01-01

Abstract. Building on Cassirer's philosophy of symbolic forms, this paper argues that the continuities and discontinuities characterizing the passage from medieval politics to modern democracy can best be understood by reference to political power's symbolic structure. For the one, political power,

Micro benchtop optics by bulk silicon micromachining

Science.gov (United States)

Lee, Abraham P.; Pocha, Michael D.; McConaghy, Charles F.; Deri, Robert J.

2000-01-01

Micromachining of bulk silicon utilizing the parallel etching characteristics of bulk silicon and integrating the parallel etch planes of silicon with silicon wafer bonding and impurity doping, enables the fabrication of on-chip optics with in situ aligned etched grooves for optical fibers, micro-lenses, photodiodes, and laser diodes. Other optical components that can be microfabricated and integrated include semi-transparent beam splitters, micro-optical scanners, pinholes, optical gratings, micro-optical filters, etc. Micromachining of bulk silicon utilizing the parallel etching characteristics thereof can be utilized to develop miniaturization of bio-instrumentation such as wavelength monitoring by fluorescence spectrometers, and other miniaturized optical systems such as Fabry-Perot interferometry for filtering of wavelengths, tunable cavity lasers, micro-holography modules, and wavelength splitters for optical communication systems.

17 CFR 232.306 - Foreign language documents and symbols.

Science.gov (United States)

2010-04-01

... symbols. 232.306 Section 232.306 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION... § 232.306 Foreign language documents and symbols. (a) All electronic filings and submissions must be in... words or letters in the English language rather than representative symbols, except that HTML documents...

Symbol manipulation and rule learning in spiking neuronal networks.

Science.gov (United States)

Fernando, Chrisantha

2011-04-21

It has been claimed that the productivity, systematicity and compositionality of human language and thought necessitate the existence of a physical symbol system (PSS) in the brain. Recent discoveries about temporal coding suggest a novel type of neuronal implementation of a physical symbol system. Furthermore, learning classifier systems provide a plausible algorithmic basis by which symbol re-write rules could be trained to undertake behaviors exhibiting systematicity and compositionality, using a kind of natural selection of re-write rules in the brain, We show how the core operation of a learning classifier system, namely, the replication with variation of symbol re-write rules, can be implemented using spike-time dependent plasticity based supervised learning. As a whole, the aim of this paper is to integrate an algorithmic and an implementation level description of a neuronal symbol system capable of sustaining systematic and compositional behaviors. Previously proposed neuronal implementations of symbolic representations are compared with this new proposal. Copyright © 2011 Elsevier Ltd. All rights reserved.

Automatic Generation of Symbolic Model for Parameterized Synchronous Systems

Institute of Scientific and Technical Information of China (English)

Wei-Wen Xu

2004-01-01

With the purpose of making the verification of parameterized system more general and easier, in this paper, a new and intuitive language PSL (Parameterized-system Specification Language) is proposed to specify a class of parameterized synchronous systems. From a PSL script, an automatic method is proposed to generate a constraint-based symbolic model. The model can concisely symbolically represent the collections of global states by counting the number of processes in a given state. Moreover, a theorem has been proved that there is a simulation relation between the original system and its symbolic model. Since the abstract and symbolic techniques are exploited in the symbolic model, state-explosion problem in traditional verification methods is efficiently avoided. Based on the proposed symbolic model, a reachability analysis procedure is implemented using ANSI C++ on UNIX platform. Thus, a complete tool for verifying the parameterized synchronous systems is obtained and tested for some cases. The experimental results show that the method is satisfactory.

Developmental change in children's sensitivity to sound symbolism.

Science.gov (United States)

Tzeng, Christina Y; Nygaard, Lynne C; Namy, Laura L

2017-08-01

The current study examined developmental change in children's sensitivity to sound symbolism. Three-, five-, and seven-year-old children heard sound symbolic novel words and foreign words meaning round and pointy and chose which of two pictures (one round and one pointy) best corresponded to each word they heard. Task performance varied as a function of both word type and age group such that accuracy was greater for novel words than for foreign words, and task performance increased with age for both word types. For novel words, children in all age groups reliably chose the correct corresponding picture. For foreign words, 3-year-olds showed chance performance, whereas 5- and 7-year-olds showed reliably above-chance performance. Results suggest increased sensitivity to sound symbolic cues with development and imply that although sensitivity to sound symbolism may be available early and facilitate children's word-referent mappings, sensitivity to subtler sound symbolic cues requires greater language experience. Copyright © 2017 Elsevier Inc. All rights reserved.

Anomalous diffusion in a symbolic model

International Nuclear Information System (INIS)

Ribeiro, H V; Lenzi, E K; Mendes, R S; Santoro, P A

2011-01-01

In this work, we investigate some statistical properties of symbolic sequences generated by a numerical procedure in which the symbols are repeated following the power-law probability density. In this analysis, we consider that the sum of n symbols represents the position of a particle in erratic movement. This approach reveals a rich diffusive scenario characterized by non-Gaussian distribution and, depending on the power-law exponent or the procedure used to build the walker, we may have superdiffusion, subdiffusion or usual diffusion. Additionally, we use the continuous-time random walk framework to compare the analytic results with the numerical data, thereby finding good agreement. Because of its simplicity and flexibility, this model can be a candidate for describing real systems governed by power-law probability densities.

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.

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.)

Optical music recognition on the International Music Score Library Project

Science.gov (United States)

Raphael, Christopher; Jin, Rong

2013-12-01

A system is presented for optical recognition of music scores. The system processes a document page in three main phases. First it performs a hierarchical decomposition of the page, identifying systems, staves and measures. The second phase, which forms the heart of the system, interprets each measure found in the previous phase as a collection of non-overlapping symbols including both primitive symbols (clefs, rests, etc.) with fixed templates, and composite symbols (chords, beamed groups, etc.) constructed through grammatical composition of primitives (note heads, ledger lines, beams, etc.). This phase proceeds by first building separate top-down recognizers for the symbols of interest. Then, it resolves the inevitable overlap between the recognized symbols by exploring the possible assignment of overlapping regions, seeking globally optimal and grammatically consistent explanations. The third phase interprets the recognized symbols in terms of pitch and rhythm, focusing on the main challenge of rhythm. We present results that compare our system to the leading commercial OMR system using MIDI ground truth for piano music.

Influence of colour on acquisition and generalisation of graphic symbols.

Science.gov (United States)

Hetzroni, O E; Ne'eman, A

2013-07-01

Children with autism may benefit from using graphic symbols for their communication, language and literacy development. The purpose of this study was to investigate the influence of colour versus grey-scale displays on the identification of graphic symbols using a computer-based intervention. An alternating treatment design was employed to examine the learning and generalisation of 58 colour and grey-scale symbols by four preschool children with autism. The graphic symbols were taught via a meaning-based intervention using stories and educational games. Results demonstrate that all of the children were able to learn and maintain symbol identification over time for both symbol displays with no apparent differences. Differences were apparent for two of the children who exhibited better generalisation when learning grey-scale symbols first. The other two showed no noticeable difference, between displays when generalising from one display to the other. Implications and further research are discussed. © 2012 The Authors. Journal of Intellectual Disability Research © 2012 John Wiley & Sons Ltd, MENCAP & IASSID.

Cognitive Deficits and Symbolic Play in Preschoolers with Autism

Science.gov (United States)

Lam, Yan Grace; Yeung, Siu-sze Susanna

2012-01-01

This study investigated symbolic play in 12 children with autism and 12 children with typical development and compared theories that consider either theory of mind, executive function or central coherence to be causally involved in the development of symbolic play in autism. Children with autism demonstrated significantly less symbolic play than…

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

Social and Symbolic Capital in Firm Clusters

DEFF Research Database (Denmark)

Gretzinger, Susanne; Royer, Susanne

Based on a relational perspective this paper analyses the case of the “Mechatronics Cluster” in Southern Jutland, Denmark. We found that cluster managers are not aware of the importance of social and symbolic capital. Cluster managers could have access to both but they are not aware...... of this resource and they don´t have any knowledge how to manage social and symbolic capital. Just to integrate social-capital-supporting initiatives in the day to day business would help to develop and to foster social and symbolic capital on a low cost level. And in our example just to integrate successful sub...

Assembly processor program converts symbolic programming language to machine language

Science.gov (United States)

Pelto, E. V.

1967-01-01

Assembly processor program converts symbolic programming language to machine language. This program translates symbolic codes into computer understandable instructions, assigns locations in storage for successive instructions, and computer locations from symbolic addresses.

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)

Low complexity symbol-wise beamforming for MIMO-OFDM systems

KAUST Repository

Lee, Hyun Ho

2011-12-01

In this paper, we consider a low complexity symbol-wise beamforming for MIMO-OFDM systems. We propose a non-iterative algorithm for the symbol-wise beamforming, which can provide the performance approaching that of the conventional symbol-wise beamforming based on the iterative algorithm. We demonstrate that our proposed scheme can reduce the computational complexity significantly. From our simulation results, it is evident that our proposed scheme leads to a negligible performance loss compared to the conventional symbol-wise beamforming regardless of spatial correlation or presence of co-channel interference. © 2011 IEEE.

Waveguide-type optical circuits for recognition of optical 8QAM-coded label

Science.gov (United States)

Surenkhorol, Tumendemberel; Kishikawa, Hiroki; Goto, Nobuo; Gonchigsumlaa, Khishigjargal

2017-10-01

Optical signal processing is expected to be applied in network nodes. In photonic routers, label recognition is one of the important functions. We have studied different kinds of label recognition methods so far for on-off keying, binary phase-shift keying, quadrature phase-shift keying, and 16 quadrature amplitude modulation-coded labels. We propose a method based on waveguide circuits to recognize an optical eight quadrature amplitude modulation (8QAM)-coded label by simple passive optical signal processing. The recognition of the proposed method is theoretically analyzed and numerically simulated by the finite difference beam propagation method. The noise tolerance is discussed, and bit-error rate against optical signal-to-noise ratio is evaluated. The scalability of the proposed method is also discussed theoretically for two-symbol length 8QAM-coded labels.

Children’s Mapping between Non-Symbolic and Symbolic Numerical Magnitudes and Its Association with Timed and Untimed Tests of Mathematics Achievement

Science.gov (United States)

Brankaer, Carmen; Ghesquière, Pol; De Smedt, Bert

2014-01-01

The ability to map between non-symbolic numerical magnitudes and Arabic numerals has been put forward as a key factor in children’s mathematical development. This mapping ability has been mainly examined indirectly by looking at children’s performance on a symbolic magnitude comparison task. The present study investigated mapping in a more direct way by using a task in which children had to choose which of two choice quantities (Arabic digits or dot arrays) matched the target quantity (dot array or Arabic digit), thereby focusing on small quantities ranging from 1 to 9. We aimed to determine the development of mapping over time and its relation to mathematics achievement. Participants were 36 first graders (M = 6 years 8 months) and 46 third graders (M = 8 years 8 months) who all completed mapping tasks, symbolic and non-symbolic magnitude comparison tasks and standardized timed and untimed tests of mathematics achievement. Findings revealed that children are able to map between non-symbolic and symbolic representations and that this mapping ability develops over time. Moreover, we found that children’s mapping ability is related to timed and untimed measures of mathematics achievement, over and above the variance accounted for by their numerical magnitude comparison skills. PMID:24699664

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.

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)

Symbolic analysis of spatio-temporal systems: The measurement problem

International Nuclear Information System (INIS)

Brown, R.; Tang, Xianzhu; Tracy, E.R.

1996-01-01

We consider the problem of measuring physical quantities using time-series observations. The approach taken is to validate theoretical models which are derived heuristically or from first principles. The fitting of parameters in such models constitutes the measurement. This is a basic problem in measurement science and a wide array of tools are available. However, an important gap in the present toolkit exists when the system of interest, and hence the models used, exhibit chaotic or turbulent behavior. The development of reliable schemes for analyzing such signals is necessary before one can claim to have a quantitative understanding of the underlying physics. In experimental situations, the number of independently measured time-series is limited, but the number of dynamical degrees of freedom can be large. In addition, the signals of interest will typically be embedded in a noisy background. In the symbol statistics approach, the time-series is coarse-grained and converted into a long, symbol stream. The probability of occurrence of various symbol sequences of fixed length constitutes the symbol statistics. These statistics contain a wealth of information about the underlying dynamics and, as we shall discuss, can be used to validate models. Previously, we have applied this symbolic approach to low dimensional systems with great success. The symbol statistics are robust up to noise/signal ∼20%. At higher noise levels the symbol statistics are biased, but in a relatively simple manner. By including the noise characteristics into the model, we were able to use the symbol statistics to measure parameters even when signal/noise is ∼ O(1). More recently, we have extended the symbolic approach to spatio-temporal systems. We have considered both coupled-map lattices and the complex Ginzburg-Landau equation. This equation arises generically near the onset of instabilities

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.

49 CFR Appendix B to Part 172 - Trefoil Symbol

Science.gov (United States)

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Trefoil Symbol B Appendix B to Part 172... SECURITY PLANS Pt. 172, App. B Appendix B to Part 172—Trefoil Symbol 1. Except as provided in paragraph 2 of this appendix, the trefoil symbol required for RADIOACTIVE labels and placards and required to be...

Symbols and schemas in emotional eating

DEFF Research Database (Denmark)

Grunert, Suzanne C.

1995-01-01

. Particularly the aspects of security and pleasure are suggested to be important motivators for emotional eating. How these symbolic meanings relate to eating as a regulatory device for emotions is explained by a schema- theoretical approach distinguishing between automatic adaptation mechanisms and strategic......Emotional eating behaviour has been of interest to psychologists exclusively as a disorder. However, evidence suggests that it is a common aspect of normal food habits, initiated by both positive and negative emotions in order to regulate these. T behaviour thus serves to regain or preserve...... the psycho-mental homeostasis. To explain this phenomenon it is first shown which symbolic meanings are associated with eating and foods. The numerous connotations can be grouped into four basic dimensions: Security and pleasure as self-oriented, and status and prestige as socially oriented emotional symbols...

The sound symbolism bootstrapping hypothesis for language acquisition and language evolution.

Science.gov (United States)

Imai, Mutsumi; Kita, Sotaro

2014-09-19

Sound symbolism is a non-arbitrary relationship between speech sounds and meaning. We review evidence that, contrary to the traditional view in linguistics, sound symbolism is an important design feature of language, which affects online processing of language, and most importantly, language acquisition. We propose the sound symbolism bootstrapping hypothesis, claiming that (i) pre-verbal infants are sensitive to sound symbolism, due to a biologically endowed ability to map and integrate multi-modal input, (ii) sound symbolism helps infants gain referential insight for speech sounds, (iii) sound symbolism helps infants and toddlers associate speech sounds with their referents to establish a lexical representation and (iv) sound symbolism helps toddlers learn words by allowing them to focus on referents embedded in a complex scene, alleviating Quine's problem. We further explore the possibility that sound symbolism is deeply related to language evolution, drawing the parallel between historical development of language across generations and ontogenetic development within individuals. Finally, we suggest that sound symbolism bootstrapping is a part of a more general phenomenon of bootstrapping by means of iconic representations, drawing on similarities and close behavioural links between sound symbolism and speech-accompanying iconic gesture. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Fast Multi-Symbol Based Iterative Detectors for UWB Communications

Directory of Open Access Journals (Sweden)

Lottici Vincenzo

2010-01-01

Full Text Available Ultra-wideband (UWB impulse radios have shown great potential in wireless local area networks for localization, coexistence with other services, and low probability of interception and detection. However, low transmission power and high multipath effect make the detection of UWB signals challenging. Recently, multi-symbol based detection has caught attention for UWB communications because it provides good performance and does not require explicit channel estimation. Most of the existing multi-symbol based methods incur a higher computational cost than can be afforded in the envisioned UWB systems. In this paper, we propose an iterative multi-symbol based method that has low complexity and provides near optimal performance. Our method uses only one initial symbol to start and applies a decision directed approach to iteratively update a filter template and information symbols. Simulations show that our method converges in only a few iterations (less than 5, and that when the number of symbols increases, the performance of our method approaches that of the ideal Rake receiver.

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 ...

Symbolic Multidimensional Scaling

NARCIS (Netherlands)

P.J.F. Groenen (Patrick); Y. Terada

2015-01-01

markdownabstract__Abstract__ Multidimensional scaling (MDS) is a technique that visualizes dissimilarities between pairs of objects as distances between points in a low dimensional space. In symbolic MDS, a dissimilarity is not just a value but can represent an interval or even a histogram. Here,

High Throughput, Label-free Screening Small Molecule Compound Libraries for Protein-Ligands using Combination of Small Molecule Microarrays and a Special Ellipsometry-based Optical Scanner.

Science.gov (United States)

Landry, James P; Fei, Yiyan; Zhu, X D

2011-12-01

Small-molecule compounds remain the major source of therapeutic and preventative drugs. Developing new drugs against a protein target often requires screening large collections of compounds with diverse structures for ligands or ligand fragments that exhibit sufficiently affinity and desirable inhibition effect on the target before further optimization and development. Since the number of small molecule compounds is large, high-throughput screening (HTS) methods are needed. Small-molecule microarrays (SMM) on a solid support in combination with a suitable binding assay form a viable HTS platform. We demonstrate that by combining an oblique-incidence reflectivity difference optical scanner with SMM we can screen 10,000 small-molecule compounds on a single glass slide for protein ligands without fluorescence labeling. Furthermore using such a label-free assay platform we can simultaneously acquire binding curves of a solution-phase protein to over 10,000 immobilized compounds, thus enabling full characterization of protein-ligand interactions over a wide range of affinity constants.

Democratisation of AAC Symbol Choices Using Technology.

Science.gov (United States)

Draffan, E A; Wald, Mike; Zeinoun, Nadine; Banes, David

2017-01-01

The use of an online voting system has been developed to enable democratic choices of newly designed symbols to support speech, language and literacy skills in a localisation situation. The system works for those using and supporting Augmentative and Alternative Communication (AAC) symbols on electronic systems by the provision of simplified scales of acceptance and adapted grids. The methodology and results highlighted the importance of user participation at the outset and concrete examples of symbol adaptations that were found necessary to ensure higher levels of user satisfaction. Design changes included appropriate local dress codes, linguistic nuances, social settings, the built environment and religious sensitivities.

Carrier tracking by smoothing filter can improve symbol SNR

Science.gov (United States)

Hurd, W. J.; Pomalaza-Raez, C. A.

1985-01-01

The potential benefit of using a smoothing filter to estimate carrier phase over use of phase locked loops (PLL) is determined. Numerical results are presented for the performance of three possible configurations of the deep space network advanced receiver. These are residual carrier PLL, sideband aided residual carrier PLL, and finally sideband aiding with a Kalman smoother. The average symbol signal to noise ratio (CNR) after losses due to carrier phase estimation error is computed for different total power SNRs, symbol rates and symbol SNRs. It is found that smoothing is most beneficial for low symbol SNRs and low symbol rates. Smoothing gains up to 0.4 dB over a sideband aided residual carrier PLL, and the combined benefit of smoothing and sideband aiding relative to a residual carrier loop is often in excess of 1 dB.

Symbolic initiative and its application to computers

Energy Technology Data Exchange (ETDEWEB)

Hellerman, L

1982-01-01

The author reviews the role of symbolic initiative in mathematics and then defines a sense in which computers compute mathematical functions. This allows a clarification of the semantics of computer and communication data. Turing's view of machine intelligence is examined in terms of its use of symbolic initiative. 12 references.

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.

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.

Simply scan--optical methods for elemental carbon measurement in diesel exhaust particulate.

Science.gov (United States)

Forder, James A

2014-08-01

This article describes a performance assessment of three optical methods, a Magee Scientific OT21 Transmissometer, a Hach-Lange Microcolor II difference gloss meter, and a combination of an office scanner with Adobe Photoshop software. The optical methods measure filter staining as a proxy for elemental carbon in diesel exhaust particulate (DEP) exposure assessment and the suitability of each as a replacement for the existing Bosch meter optical method. Filters loaded with DEP were produced from air in a non-coal mine and the exhaust gases from a mobile crane. These were measured with each apparatus and then by combustion to obtain a reference elemental carbon value. The results from each apparatus were then plotted against both the Bosch number and reference elemental carbon values. The equations of the best fit lines for these plots were derived, and these gave functions for elemental carbon and Bosch number from the output of each new optical method. For each optical method, the range of DEP loadings which can be measured has been determined, and conversion equations for elemental carbon and Bosch number have been obtained. All three optical methods studied will effectively quantify blackness as a measure of elemental carbon. Of these the Magee Scientific OT21 transmissometer has the best performance. The Microcolor II and scanner/photoshop methods will in addition allow conversion to Bosch number which may be useful if historical Bosch data are available and functions for this are described. The scanner/photoshop method demonstrates a technique to obtain measurements of DEP exposure without the need to purchase specialized instrumentation. © The Author 2014. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

On the symbolism of the white coat.

Science.gov (United States)

Nash, David A

2014-12-01

The white coat ceremony has become an academic ritual in the health professions: a ceremony that signals a transformation of status from ordinary student to that of one studying to become a health professional. While donning the white coat is a sign of a changed role, the white coat is also a powerful symbol of transformation. White is a symbol of purity, and the white coat symbolizes the purity of purpose being affirmed in becoming a health professional. Dentistry is afforded the status of a learned profession as a result of the power dentists possess over patients seeking care; this power is based in sophisticated knowledge. Patients must trust that the dentist's knowledge and skills will be used in their best interest-always to benefit, never to exploit. The white coat symbolizes an affirmation on the part of aspiring dentists that their purpose will be pure and that they can be trusted to honor the tradition of the learned professions in placing the interest of patients above self. Absent an emphasis on the symbolic nature of the white coat ceremony, it can simply become an opportunity to publicly congratulate individuals for their success in gaining entrance to the study of dentistry. By understanding its significance, however, the white coat ceremony can serve as a powerful, meaningful ritual emphasizing the transformation occurring within an individual who is entering the profession of dentistry.

The relationship between symbolic interactionism and interpretive description.

Science.gov (United States)

Oliver, Carolyn

2012-03-01

In this article I explore the relationship between symbolic interactionist theory and interpretive description methodology. The two are highly compatible, making symbolic interactionism an excellent theoretical framework for interpretive description studies. The pragmatism underlying interpretive description supports locating the methodology within this cross-disciplinary theory to make it more attractive to nonnursing researchers and expand its potential to address practice problems across the applied disciplines. The theory and method are so compatible that symbolic interactionism appears to be part of interpretive description's epistemological foundations. Interpretive description's theoretical roots have, to date, been identified only very generally in interpretivism and the philosophy of nursing. A more detailed examination of its symbolic interactionist heritage furthers the contextualization or forestructuring of the methodology to meet one of its own requirements for credibility.

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

The Scientific Import of Symbols in Human Knowledge

African Journals Online (AJOL)

Nneka Umera-Okeke

symbolism is restricted to the Arts, especially logic and literature. However ... scholars are aware of this great epistemological base and potentiality of symbols and ... Similarly, in the traditional African setting, the theory of demonology, by.

L’IMPORTANCE DU SYMBOLE ET DU SYMBOLISME DANS LE DEVELOPPEMENT PSYCHIQUE

Directory of Open Access Journals (Sweden)

Gabriel BALACI

2011-04-01

Full Text Available The Symbol in Psychoanalyze is defined as an indirectrepresentation of an object, person, idea, supernatural being, etc. This indirectrepresentation is nothing but a synthesis of all the others means of expression ascomparisony, allegory, metaphor etc. For a psychic content to be symbolized,namely expressed in a symbolic form, is mandatory for it to be repressed in theunconscious. The Symbolism is a representations system based on symbols andaims the expression and the transmission of beliefs and traditions from onegeneration to another.

Towards Symbolic Encryption Schemes

DEFF Research Database (Denmark)

Ahmed, Naveed; Jensen, Christian D.; Zenner, Erik

2012-01-01

, namely an authenticated encryption scheme that is secure under chosen ciphertext attack. Therefore, many reasonable encryption schemes, such as AES in the CBC or CFB mode, are not among the implementation options. In this paper, we report new attacks on CBC and CFB based implementations of the well......Symbolic encryption, in the style of Dolev-Yao models, is ubiquitous in formal security models. In its common use, encryption on a whole message is specified as a single monolithic block. From a cryptographic perspective, however, this may require a resource-intensive cryptographic algorithm......-known Needham-Schroeder and Denning-Sacco protocols. To avoid such problems, we advocate the use of refined notions of symbolic encryption that have natural correspondence to standard cryptographic encryption schemes....

PHILOSOPHEME OF SYMBOL AND CONCEPT OF THE MEANING: PHILOSOPHICAL AND ANTHROPOLOGICAL ASPECTS

Directory of Open Access Journals (Sweden)

P. V. Kretov

2015-12-01

Full Text Available The aim of the study is to find out the meaning of the symbolic nature of the philosophical and anthropological knowledge deployment, as well as symbolic forms of correlation between artificial and natural in the consciousness of human identity and their fixation in the language and also in the forms and structures of culture. The research is based on the methodology of historical and philosophical analysis in synchronic and diachronic aspects, principles of hermeneutic understanding and reconstruction and phenomenological descriptions. Scientific novelty is represented by the postulating such predications of symbolic structures of language and consciousness as multipanorama and transfinite, justification of the ontological status of symbol and symbolism. The symbolic functioning character of language metaphor in scientific discourse and especially the symbolic dimension of semantic field of language and culture, as well as their symbolic association was fixed. The author proves the thesis about the symbolic nature of a holistic, means forming, philosophical knowledge of man, and the relation between the underlying symbolic and metaphorical structures of language and the mechanisms of consciousness, which finds its expression, in particular, in the language of science. The symbolic design that transmits the philosophical aspects of meaning that go beyond definition and formal-logic descriptions is used. In the comparison of the concepts of spiral dynamics, memetics and autopoiesis the existence of a specific symbolic dimension of the semantic field of language, culture and consciousness is postulated. Conclusions of the article define the role of symbol and symbolic and metaphorical constructions and structures of language in forming the discourse of modern philosophical anthropology, which would include the whole thesaurus of language and culture.

Culture as a Moving Symbolic Border.

Science.gov (United States)

Simão, Lívia Mathias

2016-03-01

The aim of this paper is to propose the notion of culture as a symbolic moving border. Departing from both, Boesch's (1991) concept of culture as a symbolic field of action, and Herbst's (1995) co-genetic logic, I will discuss the dynamics of self-other relationships in terms of their potentiality as sources of movement in culture. A brief analysis of an empirical material is given in illustrative character of the ideas here exposed.

Symbolic logic and mechanical theorem proving

CERN Document Server

Chang, Chin-Liang

1969-01-01

This book contains an introduction to symbolic logic and a thorough discussion of mechanical theorem proving and its applications. The book consists of three major parts. Chapters 2 and 3 constitute an introduction to symbolic logic. Chapters 4-9 introduce several techniques in mechanical theorem proving, and Chapters 10 an 11 show how theorem proving can be applied to various areas such as question answering, problem solving, program analysis, and program synthesis.

Symbolic dynamics and description of complexity

International Nuclear Information System (INIS)

Hao Bailin.

1992-10-01

Symbolic dynamics provides a general framework to describe complexity of dynamical behaviour. After a discussion of the state of the filed special emphasis will be made on the role of transfer matrix (the Stefan matrix) both in deriving the grammar from known symbolic dynamics and in extracting the rules from experimental data. The block structure of the Stefan matrix may serve as another indicator of complexity of the associated dynamics. (author). 33 refs, 6 figs

Subrepresentation semirings and an analog of 6j-symbols

International Nuclear Information System (INIS)

Kwon, Namhee; Sage, Daniel S.

2008-01-01

Let V be a complex representation of the compact group G. The subrepresentation semiring associated to V is the set of subrepresentations of the algebra of linear endomorphisms of V with operations induced by the matrix operations. The study of these semirings has been motivated by recent advances in materials science, in which the search for microstructure-independent exact relations for physical properties of composites has been reduced to the study of these semirings for the rotation group SO(3). In this case, the structure constants for subrepresentation semirings can be described explicitly in terms of the 6j-symbols familiar from the quantum theory of angular momentum. In this paper, we investigate subrepresentation semirings for the class of quasisimply reducible groups defined by Mackey ['Multiplicity free representations of finite groups', Pac. J. Math. 8, 503 (1958)]. We introduce a new class of symbols called twisted 6j-symbols for these groups, and we explicitly calculate the structure constants for subrepresentation semirings in terms of these symbols. Moreover, we show that these symbols satisfy analog of the standard properties of classical 6j-symbols

Volume scanning three-dimensional display with an inclined two-dimensional display and a mirror scanner

Science.gov (United States)

Miyazaki, Daisuke; Kawanishi, Tsuyoshi; Nishimura, Yasuhiro; Matsushita, Kenji

2001-11-01

A new three-dimensional display system based on a volume-scanning method is demonstrated. To form a three-dimensional real image, an inclined two-dimensional image is rapidly moved with a mirror scanner while the cross-section patterns of a three-dimensional object are displayed sequentially. A vector-scan CRT display unit is used to obtain a high-resolution image. An optical scanning system is constructed with concave mirrors and a galvanometer mirror. It is confirmed that three-dimensional images, formed by the experimental system, satisfy all the criteria for human stereoscopic vision.

A LabVIEW® based generic CT scanner control software platform.

Science.gov (United States)

Dierick, M; Van Loo, D; Masschaele, B; Boone, M; Van Hoorebeke, L

2010-01-01

UGCT, the Centre for X-ray tomography at Ghent University (Belgium) does research on X-ray tomography and its applications. This includes the development and construction of state-of-the-art CT scanners for scientific research. Because these scanners are built for very different purposes they differ considerably in their physical implementations. However, they all share common principle functionality. In this context a generic software platform was developed using LabVIEW® in order to provide the same interface and functionality on all scanners. This article describes the concept and features of this software, and its potential for tomography in a research setting. The core concept is to rigorously separate the abstract operation of a CT scanner from its actual physical configuration. This separation is achieved by implementing a sender-listener architecture. The advantages are that the resulting software platform is generic, scalable, highly efficient, easy to develop and to extend, and that it can be deployed on future scanners with minimal effort.

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.

The two-loop symbol of all multi-Regge regions

International Nuclear Information System (INIS)

Bargheer, Till; Papathanasiou, Georgios; Schomerus, Volker

2016-01-01

We study the symbol of the two-loop n-gluon MHV amplitude for all Mandelstam regions in multi-Regge kinematics in N=4 super Yang-Mills theory. While the number of distinct Mandelstam regions grows exponentially with n, the increase of independent symbols turns out to be merely quadratic. We uncover how to construct the symbols for any number of external gluons from just two building blocks which are naturally associated with the six- and seven-gluon amplitude, respectively. The second building block is entirely new, and in addition to its symbol, we also construct a prototype function that correctly reproduces all terms of maximal functional transcendentality.

The two-loop symbol of all multi-Regge regions

International Nuclear Information System (INIS)

Bargheer, Till; Schomerus, Volker; Papathanasiou, Georgios

2015-12-01

We study the symbol of the two-loop n-gluon MHV amplitude for all Mandelstam regions in multi-Regge kinematics in N= 4 super Yang-Mills theory. While the number of distinct Mandelstam regions grows exponentially with n, the increase of independent symbols turns out to be merely quadratic. We uncover how to construct the symbols for any number of external gluons from just two building blocks which are naturally associated with the six- and seven-gluon amplitude, respectively. The second building block is entirely new, and in addition to its symbol, we also construct a prototype function that correctly reproduces all terms of maximal functional transcendentality.

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

Long-Term Symbolic Learning

National Research Council Canada - National Science Library

Kennedy, William G; Trafton, J. G

2007-01-01

What are the characteristics of long-term learning? We investigated the characteristics of long-term, symbolic learning using the Soar and ACT-R cognitive architectures running cognitive models of two simple tasks...

An instrument for small-animal imaging using time-resolved diffuse and fluorescence optical methods

International Nuclear Information System (INIS)

Montcel, Bruno; Poulet, Patrick

2006-01-01

We describe time-resolved optical methods that use diffuse near-infrared photons to image the optical properties of tissues and their inner fluorescent probe distribution. The assembled scanner uses picosecond laser diodes at 4 wavelengths, an 8-anode photo-multiplier tube and time-correlated single photon counting. Optical absorption and reduced scattering images as well as fluorescence emission images are computed from temporal profiles of diffuse photons. This method should improve the spatial resolution and the quantification of fluorescence signals. We used the diffusion approximation of the radiation transport equation and the finite element method to solve the forward problem. The inverse problem is solved with an optimization algorithm such as ART or conjugate gradient. The scanner and its performances are presented, together with absorption, scattering and fluorescent images obtained with it

Symbolism and Advertising in Pop Art

OpenAIRE

Willis, Nicole

2009-01-01

Introduction The premise of the written work on the subject of Symbolism and Advertising in Pop Art is to reveal that the thread of symbolism, in advertisement and other forms of media, whether it be ancient or contemporary, has been an intrinsic part of all artworks to date and that historically, movements in socio-economic structures of societies and their relative consumerism have been a catalyst in the direction of representational art works. I will first approach the conce...

Symbolic Interaction and Applied Social Research

Science.gov (United States)

Kotarba, Joseph A.

2014-01-01

In symbolic interaction, a traditional yet unfortunate and unnecessary distinction has been made between basic and applied research. The argument has been made that basic research is intended to generate new knowledge, whereas applied research is intended to apply knowledge to the solution of practical (social and organizational) problems. I will argue that the distinction between basic and applied research in symbolic interaction is outdated and dysfunctional. The masters of symbolic interactionist thought have left us a proud legacy of shaping their scholarly thinking and inquiry in response to and in light of practical issues of the day (e.g., Znaniecki, and Blumer). Current interactionist work continues this tradition in topical areas such as social justice studies. Applied research, especially in term of evaluation and needs assessment studies, can be designed to serve both basic and applied goals. Symbolic interaction provides three great resources to do this. The first is its orientation to dynamic sensitizing concepts that direct research and ask questions instead of supplying a priori and often impractical answers. The second is its orientation to qualitative methods, and appreciation for the logic of grounded theory. The third is interactionism’s overall holistic approach to interfacing with the everyday life world. The primary illustrative case here is the qualitative component of the evaluation of an NIH-funded, translational medical research program. The qualitative component has provided interactionist-inspired insights into translational research, such as examining cultural change in medical research in terms of changes in the form and content of formal and informal discourse among scientists; delineating the impact of significant symbols such as "my lab" on the social organization of science; and appreciating the essence of the self-concept "scientist" on the increasingly bureaucratic and administrative identities of medical researchers. This

The Creative Identity: Creative Behavior from the Symbolic Interactionist Perspective.

Science.gov (United States)

Petkus, Ed, Jr.

1996-01-01

This article examines the motivation of certain creative behaviors from the perspective of symbolic interactionism. The fundamental tenets of symbolic interactionism are described and the mechanics of symbolic interactionist-based, role-identity theory are explained. Ways that the theory can be applied to the motivation of creative behavior are…

Symbol addition by monkeys provides evidence for normalized quantity coding

Science.gov (United States)

Livingstone, Margaret S.; Pettine, Warren W.; Srihasam, Krishna; Moore, Brandon; Morocz, Istvan A.; Lee, Daeyeol

2014-01-01

Weber’s law can be explained either by a compressive scaling of sensory response with stimulus magnitude or by a proportional scaling of response variability. These two mechanisms can be distinguished by asking how quantities are added or subtracted. We trained Rhesus monkeys to associate 26 distinct symbols with 0–25 drops of reward, and then tested how they combine, or add, symbolically represented reward magnitude. We found that they could combine symbolically represented magnitudes, and they transferred this ability to a novel symbol set, indicating that they were performing a calculation, not just memorizing the value of each combination. The way they combined pairs of symbols indicated neither a linear nor a compressed scale, but rather a dynamically shifting, relative scaling. PMID:24753600

The Development of Symbolic and Non-Symbolic Number Line Estimations: Three Developmental Accounts Contrasted Within Cross-Sectional and Longitudinal Data

Directory of Open Access Journals (Sweden)

Delphine Sasanguie

2016-12-01

Full Text Available Three theoretical accounts have been put forward for the development of children’s response patterns on number line estimation tasks: the log-to-linear representational shift, the two-linear-to-linear transformation and the proportion judgment account. These three accounts have not been contrasted, however, within one study, using one single criterion to determine which model provides the best fit. The present study contrasted these three accounts by examining first, second and sixth graders with a symbolic and non-symbolic number line estimation task (Experiment 1. In addition, first and second graders were tested again one year later (Experiment 2. In case of symbolic estimations, the proportion judgment account described the data best. Most young children’s non-symbolic estimation patterns were best described by a logarithmic model (within the log-to-lin account, whereas those of most older children were best described by the simple power model (within the proportion judgment account.

[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.

A study on the reproducibility and spatial uniformity of N-isopropylacrylamide polymer gel dosimetry using a commercial 10X fast optical-computed tomography scanner

International Nuclear Information System (INIS)

Chang, Y J; Lin, J Q; Hsieh, B T; Chen, C H

2013-01-01

This study investigated the reproducibility and spatial uniformity of N-isopropylacrylamide (NIPAM) polymer gel as well as the reproducibility of a NIPAM polymer gel dosimeter. A commercial 10X fast optical computed tomography scanner (OCTOPUS-10X, MGS Research, Inc., Madison, CT, USA) was used as the readout tool of the NIPAM polymer gel dosimeter. A cylindrical NIPAM gel phantom measuring 10 cm (diameter) by 10 cm (height) by 3 mm (thickness) was irradiated by the four-field box treatment with a field size of 3 cm × 3 cm. The dose profiles were found to be consistent at the depths of 2.0 cm to 5.0 cm for two independent gel phantom batches, and the average uncertainty was less than 2%. The gamma pass rates were calculated to be between 94% and 95% at depths of 40 mm for two independent gel phantom batches using 4% dose difference and 4 mm distance-to-agreement criterion. The NIPAM polymer gel dosimeter was highly reproducible and spatially uniform. The results highlighted the potential of the NIPAM polymer gel dosimeter in radiotherapy.

Management Concerns for Optical Based Filing Systems

Science.gov (United States)

1990-03-01

terminals, WORM Palo Alto, CA 94303 drives, optical jukeboxes, printers, scanners. Candi Technology Inc. Systems integrators providing 2354 Calle Del Mundo ...firms are using them to help design everything from parts to buildings. Auto makers use them to design new car moaels and even build the cars using

On Modeling Affect in Audio with Non-Linear Symbolic Dynamics

Directory of Open Access Journals (Sweden)

Pauline Mouawad

2017-09-01

Full Text Available The discovery of semantic information from complex signals is a task concerned with connecting humans’ perceptions and/or intentions with the signals content. In the case of audio signals, complex perceptions are appraised in a listener’s mind, that trigger affective responses that may be relevant for well-being and survival. In this paper we are interested in the broader question of relations between uncertainty in data as measured using various information criteria and emotions, and we propose a novel method that combines nonlinear dynamics analysis with a method of adaptive time series symbolization that finds the meaningful audio structure in terms of symbolized recurrence properties. In a first phase we obtain symbolic recurrence quantification measures from symbolic recurrence plots, without the need to reconstruct the phase space with embedding. Then we estimate symbolic dynamical invariants from symbolized time series, after embedding. The invariants are: correlation dimension, correlation entropy and Lyapunov exponent. Through their application for the logistic map, we show that our measures are in agreement with known methods from literature. We further show that one symbolic recurrence measure, namely the symbolic Shannon entropy, correlates positively with the positive Lyapunov exponents. Finally we evaluate the performance of our measures in emotion recognition through the implementation of classification tasks for different types of audio signals, and show that in some cases, they perform better than state-of-the-art methods that rely on low-level acoustic features.

TH-CD-201-05: Characterization of a Novel Light-Collimating Tank Optical-CT System for 3D Dosimetry

Energy Technology Data Exchange (ETDEWEB)

Miles, D; Yoon, S [Duke University Medical Physics Graduate Program, Durham, NC (United States); Adamovics, J [Department of Chemistry and Biology, Rider University, Skillman, NJ (United States); Oldham, M [Duke University Medical Center, Durham, NC (United States)

2016-06-15

Purpose: Comprehensive 3D dosimetry is highly desirable for advanced clinical QA, but costly optical readout techniques have hindered widespread implementation. Here, we present the first results from a cost-effective Integrated-lens Dry-tank Optical Scanner (IDOS), designed for convenient 3D dosimetry readout of radiochromic plastic dosimeters (e.g. PRESAGE). Methods: The scanner incorporates a novel transparent light-collimating tank, which collimates a point light source into parallel-ray CT geometry. The tank was designed using an in-house Monte-Carlo optical ray-tracing simulation, and was cast in polyurethane using a 3D printed mould. IDOS spatial accuracy was evaluated by imaging a set of custom optical phantoms, with comparison to x-ray CT images. IDOS dose measurement performance was assessed by imaging PRESAGE dosimeters irradiated with simple known dose distributions (e.g., 4 field box 6MV treatment with Varian Linac). Direct comparisons were made to images from our gold standard DLOS scanner and calculated dose distributions from a commissioned Eclipse planning system. Results: All optical CT images were reconstructed at 1mm isotropic resolution. Comparison of IDOS and x-ray CT images of the geometric phantom demonstrated excellent IDOS geometric accuracy (sub-mm) throughout the dosimeter. IDOS measured 3D dose distribution agreed well with prediction from Eclipse, with 95% gamma pass rate at 3%/3mm. Cross-scanner dose measurement gamma analysis shows >90% of pixels passing at 3%/3mm. Conclusion: The first prototype of the IDOS system has demonstrated promising performance, with accurate dosimeter readout and negligible spatial distortion. The use of optical simulations and 3D printing to create a light collimating-tank has dramatically increased convenience and reduced costs by removing the need for expensive lenses and large volumes of refractive matching fluids.

TH-CD-201-05: Characterization of a Novel Light-Collimating Tank Optical-CT System for 3D Dosimetry

International Nuclear Information System (INIS)

Miles, D; Yoon, S; Adamovics, J; Oldham, M

2016-01-01

Purpose: Comprehensive 3D dosimetry is highly desirable for advanced clinical QA, but costly optical readout techniques have hindered widespread implementation. Here, we present the first results from a cost-effective Integrated-lens Dry-tank Optical Scanner (IDOS), designed for convenient 3D dosimetry readout of radiochromic plastic dosimeters (e.g. PRESAGE). Methods: The scanner incorporates a novel transparent light-collimating tank, which collimates a point light source into parallel-ray CT geometry. The tank was designed using an in-house Monte-Carlo optical ray-tracing simulation, and was cast in polyurethane using a 3D printed mould. IDOS spatial accuracy was evaluated by imaging a set of custom optical phantoms, with comparison to x-ray CT images. IDOS dose measurement performance was assessed by imaging PRESAGE dosimeters irradiated with simple known dose distributions (e.g., 4 field box 6MV treatment with Varian Linac). Direct comparisons were made to images from our gold standard DLOS scanner and calculated dose distributions from a commissioned Eclipse planning system. Results: All optical CT images were reconstructed at 1mm isotropic resolution. Comparison of IDOS and x-ray CT images of the geometric phantom demonstrated excellent IDOS geometric accuracy (sub-mm) throughout the dosimeter. IDOS measured 3D dose distribution agreed well with prediction from Eclipse, with 95% gamma pass rate at 3%/3mm. Cross-scanner dose measurement gamma analysis shows >90% of pixels passing at 3%/3mm. Conclusion: The first prototype of the IDOS system has demonstrated promising performance, with accurate dosimeter readout and negligible spatial distortion. The use of optical simulations and 3D printing to create a light collimating-tank has dramatically increased convenience and reduced costs by removing the need for expensive lenses and large volumes of refractive matching fluids.

Different ritual symbols in Igbo traditional religion and their functions ...

African Journals Online (AJOL)

Symbols change in their value and functions and as a result of the changes in cultural appreciation. The change in the emphasis on the role of symbolism in general is partly consequence of cultural intellectual, social and economic transformation. All our actions are symbolic and we cannot do without interacting with each ...

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.

Symbolism and rationality in the politics of psychoactive substances.

Science.gov (United States)

Room, Robin

2005-01-01

Psychoactive substances take on many symbolic meanings, and thus the politics of psychoactive substances has featured symbolic elements, or value-based rationality, alongside and often dominating instrumental rationality. Drawing particularly on the work of Joseph Gusfield and Nordic scholars, the chapter considers the symbolic dimension in the politics of substance use, even in Nordic countries celebrated for their societal commitment to knowledge-based policymaking, and its effects on the interplay of science and policy.

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.

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.

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...

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

Symbol Stream Combining in a Convolutionally Coded System

Science.gov (United States)

Mceliece, R. J.; Pollara, F.; Swanson, L.

1985-01-01

Symbol stream combining has been proposed as a method for arraying signals received at different antennas. If convolutional coding and Viterbi decoding are used, it is shown that a Viterbi decoder based on the proposed weighted sum of symbol streams yields maximum likelihood decisions.

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...

16-level differential phase shift keying (D16PSK) in direct detection optical communication systems

DEFF Research Database (Denmark)

Sambaraju, R.; Tokle, Torger; Jensen, J.B.

2006-01-01

Optical 16-level differential phase shift keying (D16PSK) carrying four bits for every symbol is proposed for direct detection optical communication systems. Transmitter and receiver schematics are presented, and the receiver sensitivity is discussed. We numerically investigate the impact...

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

Symbolic Processing Combined with Model-Based Reasoning

Science.gov (United States)

James, Mark

2009-01-01

A computer program for the detection of present and prediction of future discrete states of a complex, real-time engineering system utilizes a combination of symbolic processing and numerical model-based reasoning. One of the biggest weaknesses of a purely symbolic approach is that it enables prediction of only future discrete states while missing all unmodeled states or leading to incorrect identification of an unmodeled state as a modeled one. A purely numerical approach is based on a combination of statistical methods and mathematical models of the applicable physics and necessitates development of a complete model to the level of fidelity required for prediction. In addition, a purely numerical approach does not afford the ability to qualify its results without some form of symbolic processing. The present software implements numerical algorithms to detect unmodeled events and symbolic algorithms to predict expected behavior, correlate the expected behavior with the unmodeled events, and interpret the results in order to predict future discrete states. The approach embodied in this software differs from that of the BEAM methodology (aspects of which have been discussed in several prior NASA Tech Briefs articles), which provides for prediction of future measurements in the continuous-data domain.

Symbolic Water Imagery in the Drama of J. P. Clark- Bekederemo

African Journals Online (AJOL)

Prof

Key words: Imagery, Symbolism, Water, Drama, J. P. Clark-Bekederemo. Introduction .... the other types (the literal and the figurative) is that a symbolic image has the capacity to extend its ..... A Dictionary of Literary Symbols. Cambridge: ...

The method of covariant symbols in curved space-time

International Nuclear Information System (INIS)

Salcedo, L.L.

2007-01-01

Diagonal matrix elements of pseudodifferential operators are needed in order to compute effective Lagrangians and currents. For this purpose the method of symbols is often used, which however lacks manifest covariance. In this work the method of covariant symbols, introduced by Pletnev and Banin, is extended to curved space-time with arbitrary gauge and coordinate connections. For the Riemannian connection we compute the covariant symbols corresponding to external fields, the covariant derivative and the Laplacian, to fourth order in a covariant derivative expansion. This allows one to obtain the covariant symbol of general operators to the same order. The procedure is illustrated by computing the diagonal matrix element of a nontrivial operator to second order. Applications of the method are discussed. (orig.)

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.)

Management as a Symbolizing Construction? Re-Arranging the Understanding of Management

Directory of Open Access Journals (Sweden)

Katharina Mayr

2010-09-01

Full Text Available In this article, we outline the concept of management as a symbolizing construction. According to Niklas LUHMANN, organizations process by referring to decisions. But decisions are not simply "given" and in principle invisible. This is the reason why organizations institute formalities like protocols, signatures or other insignia of the official that symbolize the decision—without actually being a decision. These symbols allow for making decisions "process-able." And just like a protocol or a signature, management symbolizes decisions as well. Management provides an organizational practice with symbols of decision making without being the "unity" of the decisions, as decisions perpetually have to be reconstructed, redefined and rearranged in the communication of all organizational units. Therefore management symbolizes on the one hand more than it can achieve. On the other hand the importance of management as a symbolizing construction lies in allowing the reconstruction, redefining and rearrangement of decisions by making them visible and recognizable. Heroic managers, meetings, management tools and procedures are solutions to the paradox of decision making. By symbolizing decidedness they create credibilities that conceal the self-referential construction of organizational communication and the paradox of its decision praxis. URN: urn:nbn:de:0114-fqs1003218

Awareness and use of the Heart Symbol by Finnish consumers.

Science.gov (United States)

Lahti-Koski, Marjaana; Helakorpi, Satu; Olli, Mari; Vartiainen, Erkki; Puska, Pekka

2012-03-01

To study the awareness of the Heart Symbol in different age and educational groups, and changes in the awareness over a 9-year period. In addition, the reported use of products with the symbol was examined. A series of annual cross-sectional postal surveys on Health Behaviour and Health among the Finnish Adult Population. A random sample (n 5000 per annum) from the Finnish population aged 15-64 years, drawn from the National Population Register, received a questionnaire. Men and women (n 29 378) participating in the surveys in 2000-2009. At the early 2000s, 48 % of men and 73 % of women reported to be familiar with the symbol. The corresponding rates were 66 % for men and 91 % for women in 2009. The reported use of products with the symbol increased from 29 % to 52 % in men and from 40 % to 72 % in women. In men, the awareness did not vary by age, whereas older women (45-64 years) were less likely to be aware of the symbol compared with younger women (25-34 years). Men and women with the highest education were best aware of the symbol and more likely to use the products in the early 2000s. The educational differences diminished or disappeared during the study period. The majority of Finnish adults are familiar with the Heart Symbol, and the reported use of such products increased in all age and educational groups, especially among the less educated. The symbol may work as an effective measure to diminish nutrition-related health inequalities.

Symbolic BDD and ADD Algorithms for Energy Games

Directory of Open Access Journals (Sweden)

Shahar Maoz

2016-11-01

Full Text Available Energy games, which model quantitative consumption of a limited resource, e.g., time or energy, play a central role in quantitative models for reactive systems. Reactive synthesis constructs a controller which satisfies a given specification, if one exists. For energy games a synthesized controller ensures to satisfy not only the safety constraints of the specification but also the quantitative constraints expressed in the energy game. A symbolic algorithm for energy games, recently presented by Chatterjee et al., is symbolic in its representation of quantitative values but concrete in the representation of game states and transitions. In this paper we present an algorithm that is symbolic both in the quantitative values and in the underlying game representation. We have implemented our algorithm using two different symbolic representations for reactive games, Binary Decision Diagrams (BDD and Algebraic Decision Diagrams (ADD. We investigate the commonalities and differences of the two implementations and compare their running times on specifications of energy games.

A STUDY OF SYMBOLIC RELATIONS IN PUBLIC TRANSPORT

Directory of Open Access Journals (Sweden)

ANDREI BALAN

2011-04-01

Full Text Available This paper presents an anthropological, exploratory study of the microsocial world of public transport. Our research focuses on the symbolic relations that are being established (verbally or nonverbally between urban transport travellers that do not know each other and the consequences these relations create. Modern urban configuration forces large numbers of individuals to share public space every day. When this space becomes restrictive, symbolic relations and interpersonal behaviors such as territoriality and personal space management become clearer. Due to overcrowding, public transport is the scene of one of the most restrictive public spaces in a city. The challenge was to observe and interpret daily, casual behaviors through a sociological and psychological scheme, following the methodological tradition established by Erving Goffman and the other symbolic interactionists. Finally, our study generates a number of hypotheses and explanatory models for common practices and behaviors in trams and metros regarded from a symbolic perspective.

Multiformity of inherent randomicity and visitation density in n symbolic dynamics

International Nuclear Information System (INIS)

Zhang Yagang; Wang Changjiang

2007-01-01

The multiformity of inherent randomicity and visitation density in n symbolic dynamics will be clarified in this paper. These stochastic symbolic sequences bear three features. The distribution of frequency, inter-occurrence times and the alignment of two random sequences are amplified in detail. The features of visitation density in surjective maps presents catholicity and the catholicity in n letters randomicity has the same measure foundation. We hope to offer a symbolic platform that satisfies these stochastic properties and to attempt to study certain properties of DNA base sequences, 20 amino acids symbolic sequences of proteid structure, and the time series that can be symbolic in finance market et al

HMD symbol stabilization concepts

Science.gov (United States)

Newman, Richard L.; Greeley, Kevin W.

1995-05-01

Helmet-mounted displays (HMDs) present flight, navigation, and weapon information in the pilot's line of sight. The HMD was developed to allow the pilot to retain aircraft and weapon information while looking off boresight. Symbol stabilization is a key issue for HMDs. In current equipment, the lack of compensation for pilot head motion creates excessive workload during hovering and nap-of-the-earth flight. This high workload translates into excessive training requirements. At the same time, misleading symbology makes interpretation of the height of obstructions impossible. A set of standardized coordinate transformations are necessary for the development of HMD symbology and the control laws. Part of the problem is there is no agreed upon set of definitions or descriptions for how HMD symbols are driven to compensate for pilot head motion. A candidate set of coordinate definitions is proposed to address this issue.

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)

Consumers’ perception of symbols and health claims as health-related label messages

DEFF Research Database (Denmark)

Carrillo, E.; Fiszman, S.; Lähteenmäki, Liisa

2014-01-01

The package is the first contact between the food and the consumer and an excellent vehicle for communication with the consumer. Visual cues (symbols) on the package can be used to communicate health-related information. Although EU legislation provides for the use of symbols, there could......’s appeal and convincingness in two countries, one Mediterranean (Spain) and the other Scandinavian (Denmark). Four symbols were employed in the study: (1) heart-plus-stethoscope, (2) olives (a symbol often used in Spain but not so much in Denmark), and two not directly linked to food products: (3) active...... of the symbols perceived by the participants was similar in both countries but the culture influenced the connotations attached to the symbols. In addition, the symbols on the packaging were found to be more important than the verbal information....

Symbolic Form in the Pedagogical Implications of Sociolinguistics

Science.gov (United States)

Tolic, Mirela

2011-01-01

The author with the help of analysis of symbolic forms and sociolinguistics explains the transformation of "homo communicans in conscious homo symbolicum." He points out the importance of etymological analysis Cassierer's philosophy of symbolic forms and its effects in the modern understanding of sociolinguistics. It is necessary their…

Multi Optical Transition Radiation System for ATF2

International Nuclear Information System (INIS)

Alabau-Gonzalvo, Javier

2012-01-01

In this paper we describe the design, installation and first calibration tests of a Multi Optical Transition Radiation System in the beam diagnostic section of the Extraction (EXT) line of ATF2, close to the multi wire scanner system. This system will be a valuable tool for measuring beam sizes and emittances coming from the ATF Damping Ring. With an optical resolution of about 2 (micro)m an original OTR design (OTR1X) located after the septum at the entrance of the EXT line demonstrated the ability to measure a 5.5 (micro)m beam size in one beam pulse and to take many fast measurements. This gives the OTR the ability to measure the beam emittance with high statistics, giving a low error and a good understanding of emittance jitter. Furthermore the nearby wire scanners will be a definitive test of the OTR as a beam emittance diagnostic device. The multi-OTR system design proposed here is based on the existing OTR1X.

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.

[Determining visual acuity with LH symbols and Landolt rings].

Science.gov (United States)

Gräf, M; Becker, R

1999-08-01

Lea (LH) symbols seem to be favourable for visual acuity assessment in childhood. The symbols of the LH test are well standardized and applicable to preschool children. We compared the visual acuity determined by LH single symbols (LH) and the acuity measured with the Landolt-C (LC). 138 cooperative subjects aged 7 to 91 years were examined. Their visual acuity was either normal or reduced due to various etiologies. Their refractive error was corrected. The monocular LH and LC were determined by a 3/4 criterion (study 1). In 19 healthy subjects aged 21 to 58 years, acuity was reduced stepwise by 5 different calibrated occlusives (study 2). A Lighthouse single symbol book (LH symbols) was used at a distance of 3 m. LC was determined at a distance of 5 m. The luminance of the test field was 180-200 cd/m2. The right eye of each patient and the amblyopic eye of the squinting patients was taken for statistical evaluation. The strabismic patients' interocular differences of LC and LH were compared. Within study 1, LC ranged from 0.02 to 2.0 and LH from 0.03 to 2.5. LH overestimated LC by 1.4 lines on an average (t-test p 1 line, 85.7% resp. 90% of the strabismic amblyopic patients with an interocular LC difference > 1 resp > 2 lines were detected. In study 2, LC ranged from 0.1 to 1.6, LH from 0.12 to 2.0. The mean difference LH-LC was 1.3 lines. The regression equation was lgLH = 0.91 lgLC + 0.08 (r = 0.95). LH symbols allow a reliable measurement of recognition acuity. Due to the design of the symbols, they are excellently suitable for application to preschool children. Age related normal values should be established. The systematic difference between the LC acuity and the LH acuity measured with the Lighthouse LH single symbol book by 1.4 lines has to be considered.

Temporal Probabilistic Constellation Shaping for WDM Optical Communication Systems

DEFF Research Database (Denmark)

Yankov, Metodi Plamenov; Forchhammer, Søren

2016-01-01

Finite state machine sources transmitting QPSK are studied as input to WDM optical fiber systems with ideal distributed Raman amplification. The probabilities of successive constellation symbols are shaped for nonlinear transmission and gains of around 500km (5-10%) are demonstrated...

Temporal Probabilistic Constellation Shaping for WDM Optical Communication Systems

OpenAIRE

Yankov, Metodi Plamenov; Forchhammer, Søren

2016-01-01

Finite state machine sources transmitting QPSK are studied as input to WDM optical fiber systems with ideal distributed Raman amplification. The probabilities of successive constellation symbols are shaped for nonlinear transmission and gains of around 500km (5-10%) are demonstrated

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

Multiple-Symbol Detection Of Multiple-Trellis-Coded MDPSK

Science.gov (United States)

Divsalar, Dariush; Simon, Marvin K.; Shahshahani, Mehrdad M.

1991-01-01

In proposed scheme for detection and decoding of multiple-trellis-coded multilevel differential-phase-shift-keyed (MDPSK) radio signals, observation time for differential detection extended from conventional 2 to larger number of symbol periods. Decreases rate of error in differential detection of uncoded MDPSK by increasing number of symbol periods.

Digit Symbol Performance in Mild Dementia and Depression.

Science.gov (United States)

Hart, Robert P.; And Others

1987-01-01

Patients with mild dementia of the Alzheimer's type (DAT), patients with major depression, and normal control subjects completed the Wechsler Adult Intelligence Scale (WAIS) Digit Symbol test of incidental memory. Though mild DAT and depressed patients had equivalent deficits in psychomotor speed, DAT patients recalled fewer digit-symbol items.…

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...

Isotropic Optical Mouse Placement for Mobile Robot Velocity Estimation

Directory of Open Access Journals (Sweden)

Sungbok Kim

2014-06-01

Full Text Available This paper presents the isotropic placement of multiple optical mice for the velocity estimation of a mobile robot. It is assumed that there can be positional restriction on the installation of optical mice at the bottom of a mobile robot. First, the velocity kinematics of a mobile robot with an array of optical mice is obtained and the resulting Jacobian matrix is analysed symbolically. Second, the isotropic, anisotropic and singular optical mouse placements are identified, along with the corresponding characteristic lengths. Third, the least squares mobile robot velocity estimation from the noisy optical mouse velocity measurements is discussed. Finally, simulation results for several different placements of three optical mice are given.

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.

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)

Initial evaluation of commercial optical CT-based 3D gel dosimeter

International Nuclear Information System (INIS)

Islam, K.T.S.; Dempsey, James F.; Ranade, Manisha K.; Maryanski, Marek J.; Low, Daniel A.

2003-01-01

We evaluated the OCTOPUS-ONE trade mark sign research laser CT scanner developed and manufactured by MGS Research, Inc. (Madison, CT). The scanner is designed for imaging 3D optical density distributions in BANG registered gels. The scanner operates in a translate-rotate configuration with a single scanning laser beam. The rotating cylindrical gel phantom is immersed in a refractive index matching solution and positioned at the center of a square tank made of plastic and glass. A stationary polarized He-Ne laser beam (633 nm) is reflected from a mirror moving parallel to the tank wall and scans the gel. Another mirror moves synchronously along the opposite side of the tank and collects the transmitted light and sends it to a single stationary silicon photodetector. A filtered backprojection algorithm is used to reconstruct projection data in a plane. The laser-mirrors-detector assembly is mounted on a horizontal platform that moves vertically for slice selection. We have tested the mechanical and optical setup, projection centering on the axis of rotation, linearity, and spatial resolution. We found the optical detector to respond linearly to transmitted light from control samples. The spatial resolution of the scanner was determined by employing a split field resolution technique. We obtained the horizontal and vertical full widths at half maxima of the laser beam intensity profiles as 0.6 and 0.8 mm, respectively. Dose calibration tests of the gel were performed using a nine-field (2x2 cm 2 each) dose pattern irradiated at different dose levels. Finally, we compared gel-derived 2D planar dose distribution against radiochromic film measured dose distribution for both the nine-field and a uniform 5x5 cm 2 field of 6 MV x rays. Very similar dose distributions were observed in gel and radiochromic film except in regions of steep dose gradient and highest dose. A dose normalization of 15.6% was required between the two dosimeters due to differences in overall

Symbolic interactionism as a theoretical perspective for multiple method research.

Science.gov (United States)

Benzies, K M; Allen, M N

2001-02-01

Qualitative and quantitative research rely on different epistemological assumptions about the nature of knowledge. However, the majority of nurse researchers who use multiple method designs do not address the problem of differing theoretical perspectives. Traditionally, symbolic interactionism has been viewed as one perspective underpinning qualitative research, but it is also the basis for quantitative studies. Rooted in social psychology, symbolic interactionism has a rich intellectual heritage that spans more than a century. Underlying symbolic interactionism is the major assumption that individuals act on the basis of the meaning that things have for them. The purpose of this paper is to present symbolic interactionism as a theoretical perspective for multiple method designs with the aim of expanding the dialogue about new methodologies. Symbolic interactionism can serve as a theoretical perspective for conceptually clear and soundly implemented multiple method research that will expand the understanding of human health behaviour.

VULTURES: EXEGESIS OF A SYMBOL

Directory of Open Access Journals (Sweden)

Maura Andreoni

2016-12-01

Full Text Available Depending on the different cultures and historical periods, vultures have been considered both impure or sacred. But, since they usually do not prey upon living animals, their symbolic dimension, associated to the idea of purification, is present in many myths, religions, burial praxis of ancient populations and remains in some religions today.In the ancient Mediterranean civilizations, they have been carved in some of the most ancient bas-reliefs of the history by stone age people; were sacred to Egyptians, who even took them as symbol of gods; in the classical times they were supposed to be all feminine and breed by parthenogenesis, and therefore appreciated by some early Christian authors, who came to comparing them even to the Virgin Mary; they have been studied and described by ancient scientists, naturalists, philosophers, playwrights; involved in many of the most enduring Greek and Roman myths and legends; many parts of their body were considered as a medicine or even a talisman for happiness; and they were so proverbial for Romans to become even one of the symbols of the founding of Rome itself.But they were also so fragile that perfumes, myrrh and pomegranates were supposed to be lethal for them ….

Diagrams benefit symbolic problem-solving.

Science.gov (United States)

Chu, Junyi; Rittle-Johnson, Bethany; Fyfe, Emily R

2017-06-01

The format of a mathematics problem often influences students' problem-solving performance. For example, providing diagrams in conjunction with story problems can benefit students' understanding, choice of strategy, and accuracy on story problems. However, it remains unclear whether providing diagrams in conjunction with symbolic equations can benefit problem-solving performance as well. We tested the impact of diagram presence on students' performance on algebra equation problems to determine whether diagrams increase problem-solving success. We also examined the influence of item- and student-level factors to test the robustness of the diagram effect. We worked with 61 seventh-grade students who had received 2 months of pre-algebra instruction. Students participated in an experimenter-led classroom session. Using a within-subjects design, students solved algebra problems in two matched formats (equation and equation-with-diagram). The presence of diagrams increased equation-solving accuracy and the use of informal strategies. This diagram benefit was independent of student ability and item complexity. The benefits of diagrams found previously for story problems generalized to symbolic problems. The findings are consistent with cognitive models of problem-solving and suggest that diagrams may be a useful additional representation of symbolic problems. © 2017 The British Psychological Society.

Imagining and Remembering City: Memory, Space and Symbolism of Belgrade

Directory of Open Access Journals (Sweden)

Ljiljana Rogač Mijatović

2014-11-01

Full Text Available In contemporary “runaway world”, cities are becoming the main reference point of social life, change and development. The author discusses the complex process of articulating city identity and memory, as well as the meanings that arise in the interaction of memory, space and symbols of the city, within urban symbolism and cultural memory approach. What are the strategies of activating the cultural memory through multiple symbol bearers of the city, both tangible and intangible? The case study of the city of Belgrade indicates how the narratives related to memory and symbol bearers can be used in fostering culturally sustainable development of the city.