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Sample records for smooth contours lecture

  1. Area of isodensity contours in Gaussian and non-Gaussian fields

    International Nuclear Information System (INIS)

    Ryden, B.S.

    1988-01-01

    The area of isodensity contours in a smoothed density field can be measured by the contour-crossing statistic N1, the number of times per unit length that a line drawn through the density field pierces an isodensity contour. The contour-crossing statistic distinguishes between Gaussian and non-Gaussian fields and provides a measure of the effective slope of the power spectrum. The statistic is easy to apply and can be used on pencil beams and slices as well as on a three-dimensional field. 10 references

  2. A method for smoothing segmented lung boundary in chest CT images

    Science.gov (United States)

    Yim, Yeny; Hong, Helen

    2007-03-01

    To segment low density lung regions in chest CT images, most of methods use the difference in gray-level value of pixels. However, radiodense pulmonary vessels and pleural nodules that contact with the surrounding anatomy are often excluded from the segmentation result. To smooth lung boundary segmented by gray-level processing in chest CT images, we propose a new method using scan line search. Our method consists of three main steps. First, lung boundary is extracted by our automatic segmentation method. Second, segmented lung contour is smoothed in each axial CT slice. We propose a scan line search to track the points on lung contour and find rapidly changing curvature efficiently. Finally, to provide consistent appearance between lung contours in adjacent axial slices, 2D closing in coronal plane is applied within pre-defined subvolume. Our method has been applied for performance evaluation with the aspects of visual inspection, accuracy and processing time. The results of our method show that the smoothness of lung contour was considerably increased by compensating for pulmonary vessels and pleural nodules.

  3. Shape reconstruction from apparent contours theory and algorithms

    CERN Document Server

    Bellettini, Giovanni; Paolini, Maurizio

    2015-01-01

    Motivated by a variational model concerning the depth of the objects in a picture and the problem of hidden and illusory contours, this book investigates one of the central problems of computer vision: the topological and algorithmic reconstruction of a smooth three dimensional scene starting from the visible part of an apparent contour. The authors focus their attention on the manipulation of apparent contours using a finite set of elementary moves, which correspond to diffeomorphic deformations of three dimensional scenes. A large part of the book is devoted to the algorithmic part, with implementations, experiments, and computed examples. The book is intended also as a user's guide to the software code appcontour, written for the manipulation of apparent contours and their invariants. This book is addressed to theoretical and applied scientists working in the field of mathematical models of image segmentation.

  4. GPU based contouring method on grid DEM data

    Science.gov (United States)

    Tan, Liheng; Wan, Gang; Li, Feng; Chen, Xiaohui; Du, Wenlong

    2017-08-01

    This paper presents a novel method to generate contour lines from grid DEM data based on the programmable GPU pipeline. The previous contouring approaches often use CPU to construct a finite element mesh from the raw DEM data, and then extract contour segments from the elements. They also need a tracing or sorting strategy to generate the final continuous contours. These approaches can be heavily CPU-costing and time-consuming. Meanwhile the generated contours would be unsmooth if the raw data is sparsely distributed. Unlike the CPU approaches, we employ the GPU's vertex shader to generate a triangular mesh with arbitrary user-defined density, in which the height of each vertex is calculated through a third-order Cardinal spline function. Then in the same frame, segments are extracted from the triangles by the geometry shader, and translated to the CPU-side with an internal order in the GPU's transform feedback stage. Finally we propose a "Grid Sorting" algorithm to achieve the continuous contour lines by travelling the segments only once. Our method makes use of multiple stages of GPU pipeline for computation, which can generate smooth contour lines, and is significantly faster than the previous CPU approaches. The algorithm can be easily implemented with OpenGL 3.3 API or higher on consumer-level PCs.

  5. Lectures given at the C.I.M.E. Summer School

    CERN Document Server

    Stefani, Gianna

    2008-01-01

    The lectures gathered in this volume present some of the different aspects of Mathematical Control Theory. Adopting the point of view of Geometric Control Theory and of Nonlinear Control Theory, the lectures focus on some aspects of the Optimization and Control of nonlinear, not necessarily smooth, dynamical systems. Specifically, three of the five lectures discuss respectively: logic-based switching control, sliding mode control and the input to the state stability paradigm for the control and stability of nonlinear systems. The remaining two lectures are devoted to Optimal Control: one investigates the connections between Optimal Control Theory, Dynamical Systems and Differential Geometry, while the second presents a very general version, in a non-smooth context, of the Pontryagin Maximum Principle. The arguments of the whole volume are self-contained and are directed to everyone working in Control Theory. They offer a sound presentation of the methods employed in the control and optimization of nonlinear d...

  6. Finishing aeronautical planetary herringbone gear wheels in container vibrating smoothing machine

    Directory of Open Access Journals (Sweden)

    Jacek MICHALSKI

    2015-12-01

    Full Text Available The paper presents the technological process of abrasive-chemical machining wheel bearing surface of the cylindrical herringbone gears planetary gear in vibrating container smoothing machine according to Isotropic Finishing ISF® technology of the REM Chemicals Inc. company. Gear wheels are made of stainless Pyrowear 53 and subjected to carburizing, hardening, cold working and low tempering. The change in value of deviation indicators for the kinematic accuracy, smoothness and geometric structure of the machined surfaces of the gear teeth after smoothing compared with the contoured grinding were analyzed. The findings are different a characteristic performance on the surface of the tooth side along the outline, especially with a higher value at the head of the tooths. This creates a need for appropriate modification of the lateral surface of the teeth in the process of contoured grinding. The results of the mechanical strength of the samples gear wheel after the smoothing process and evaluating the hydrogen embrittlement are presented.

  7. The Changing Tides of the Type 2 Diabetes Epidemic-Smooth Sailing or Troubled Waters Ahead? Kelly West Award Lecture 2016.

    Science.gov (United States)

    Gregg, Edward W

    2017-10-01

    The Kelly West Award for Outstanding Achievement in Epidemiology is given in memory of Kelly M. West, widely regarded as the "father of diabetes epidemiology," to an individual who has made significant contributions to the field of diabetes epidemiology. Edward W. Gregg, PhD, of the Division of Diabetes Translation, Centers for Disease Control and Prevention, Atlanta, GA, received the prestigious award at the American Diabetes Association's 76th Scientific Sessions, 10-14 June 2016, in New Orleans, LA. He presented the Kelly West Award Lecture, "Changing Tides of the Type 2 Diabetes Epidemic-Smooth Sailing or Troubled Waters Ahead?" on Sunday, 12 June 2016. © 2017 by the American Diabetes Association.

  8. SU-F-J-72: A Clinical Usable Integrated Contouring Quality Evaluation Software for Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, S; Dolly, S; Cai, B; Mutic, S; Li, H [Washington University School of Medicine, Saint Louis, MO (United States)

    2016-06-15

    Purpose: To introduce the Auto Contour Evaluation (ACE) software, which is the clinical usable, user friendly, efficient and all-in-one toolbox for automatically identify common contouring errors in radiotherapy treatment planning using supervised machine learning techniques. Methods: ACE is developed with C# using Microsoft .Net framework and Windows Presentation Foundation (WPF) for elegant GUI design and smooth GUI transition animations through the integration of graphics engines and high dots per inch (DPI) settings on modern high resolution monitors. The industrial standard software design pattern, Model-View-ViewModel (MVVM) pattern, is chosen to be the major architecture of ACE for neat coding structure, deep modularization, easy maintainability and seamless communication with other clinical software. ACE consists of 1) a patient data importing module integrated with clinical patient database server, 2) a 2D DICOM image and RT structure simultaneously displaying module, 3) a 3D RT structure visualization module using Visualization Toolkit or VTK library and 4) a contour evaluation module using supervised pattern recognition algorithms to detect contouring errors and display detection results. ACE relies on supervised learning algorithms to handle all image processing and data processing jobs. Implementations of related algorithms are powered by Accord.Net scientific computing library for better efficiency and effectiveness. Results: ACE can take patient’s CT images and RT structures from commercial treatment planning software via direct user input or from patients’ database. All functionalities including 2D and 3D image visualization and RT contours error detection have been demonstrated with real clinical patient cases. Conclusion: ACE implements supervised learning algorithms and combines image processing and graphical visualization modules for RT contours verification. ACE has great potential for automated radiotherapy contouring quality verification

  9. SU-F-J-72: A Clinical Usable Integrated Contouring Quality Evaluation Software for Radiotherapy

    International Nuclear Information System (INIS)

    Jiang, S; Dolly, S; Cai, B; Mutic, S; Li, H

    2016-01-01

    Purpose: To introduce the Auto Contour Evaluation (ACE) software, which is the clinical usable, user friendly, efficient and all-in-one toolbox for automatically identify common contouring errors in radiotherapy treatment planning using supervised machine learning techniques. Methods: ACE is developed with C# using Microsoft .Net framework and Windows Presentation Foundation (WPF) for elegant GUI design and smooth GUI transition animations through the integration of graphics engines and high dots per inch (DPI) settings on modern high resolution monitors. The industrial standard software design pattern, Model-View-ViewModel (MVVM) pattern, is chosen to be the major architecture of ACE for neat coding structure, deep modularization, easy maintainability and seamless communication with other clinical software. ACE consists of 1) a patient data importing module integrated with clinical patient database server, 2) a 2D DICOM image and RT structure simultaneously displaying module, 3) a 3D RT structure visualization module using Visualization Toolkit or VTK library and 4) a contour evaluation module using supervised pattern recognition algorithms to detect contouring errors and display detection results. ACE relies on supervised learning algorithms to handle all image processing and data processing jobs. Implementations of related algorithms are powered by Accord.Net scientific computing library for better efficiency and effectiveness. Results: ACE can take patient’s CT images and RT structures from commercial treatment planning software via direct user input or from patients’ database. All functionalities including 2D and 3D image visualization and RT contours error detection have been demonstrated with real clinical patient cases. Conclusion: ACE implements supervised learning algorithms and combines image processing and graphical visualization modules for RT contours verification. ACE has great potential for automated radiotherapy contouring quality verification

  10. Global regularizing flows with topology preservation for active contours and polygons.

    Science.gov (United States)

    Sundaramoorthi, Ganesh; Yezzi, Anthony

    2007-03-01

    Active contour and active polygon models have been used widely for image segmentation. In some applications, the topology of the object(s) to be detected from an image is known a priori, despite a complex unknown geometry, and it is important that the active contour or polygon maintain the desired topology. In this work, we construct a novel geometric flow that can be added to image-based evolutions of active contours and polygons in order to preserve the topology of the initial contour or polygon. We emphasize that, unlike other methods for topology preservation, the proposed geometric flow continually adjusts the geometry of the original evolution in a gradual and graceful manner so as to prevent a topology change long before the curve or polygon becomes close to topology change. The flow also serves as a global regularity term for the evolving contour, and has smoothness properties similar to curvature flow. These properties of gradually adjusting the original flow and global regularization prevent geometrical inaccuracies common with simple discrete topology preservation schemes. The proposed topology preserving geometric flow is the gradient flow arising from an energy that is based on electrostatic principles. The evolution of a single point on the contour depends on all other points of the contour, which is different from traditional curve evolutions in the computer vision literature.

  11. Dual conformal transformations of smooth holographic Wilson loops

    Energy Technology Data Exchange (ETDEWEB)

    Dekel, Amit [Nordita, KTH Royal Institute of Technology and Stockholm University, Roslagstullsbacken 23, SE-106 91 Stockholm (Sweden)

    2017-01-19

    We study dual conformal transformations of minimal area surfaces in AdS{sub 5}×S{sup 5} corresponding to holographic smooth Wilson loops and some other related observables. To act with dual conformal transformations we map the string solutions to the dual space by means of T-duality, then we apply a conformal transformation and finally T-dualize back to the original space. The transformation maps between string solutions with different boundary contours. The boundary contours of the minimal surfaces are not mapped back to the AdS boundary, and the regularized area of the surface changes.

  12. An automatic contour propagation method to follow parotid gland deformation during head-and-neck cancer tomotherapy

    International Nuclear Information System (INIS)

    Faggiano, E; Scalco, E; Rizzo, G; Fiorino, C; Broggi, S; Cattaneo, M; Maggiulli, E; Calandrino, R; Dell'Oca, I; Di Muzio, N

    2011-01-01

    We developed an efficient technique to auto-propagate parotid gland contours from planning kVCT to daily MVCT images of head-and-neck cancer patients treated with helical tomotherapy. The method deformed a 3D surface mesh constructed from manual kVCT contours by B-spline free-form deformation to generate optimal and smooth contours. Deformation was calculated by elastic image registration between kVCT and MVCT images. Data from ten head-and-neck cancer patients were considered and manual contours by three observers were included in both kVCT and MVCT images. A preliminary inter-observer variability analysis demonstrated the importance of contour propagation in tomotherapy application: a high variability was reported in MVCT parotid volume estimation (p = 0.0176, ANOVA test) and a larger uncertainty of MVCT contouring compared with kVCT was demonstrated by DICE and volume variability indices (Wilcoxon signed rank test, p -4 for both indices). The performance analysis of our method showed no significant differences between automatic and manual contours in terms of volumes (p > 0.05, in a multiple comparison Tukey test), center-of-mass distances (p = 0.3043, ANOVA test), DICE values (p = 0.1672, Wilcoxon signed rank test) and average and maximum symmetric distances (p = 0.2043, p = 0.8228 Wilcoxon signed rank tests). Results suggested that our contour propagation method could successfully substitute human contouring on MVCT images.

  13. An automatic contour propagation method to follow parotid gland deformation during head-and-neck cancer tomotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Faggiano, E; Scalco, E; Rizzo, G [Istituto di Bioimmagini e Fisiologia Molecolare (IBFM), CNR, Milan (Italy); Fiorino, C; Broggi, S; Cattaneo, M; Maggiulli, E; Calandrino, R [Department of Medical Physics, San Raffaele Scientific Institute, Milan (Italy); Dell' Oca, I; Di Muzio, N, E-mail: fiorino.claudio@hsr.it [Department of Radiotherapy, San Raffaele Scientific Institute, Milan (Italy)

    2011-02-07

    We developed an efficient technique to auto-propagate parotid gland contours from planning kVCT to daily MVCT images of head-and-neck cancer patients treated with helical tomotherapy. The method deformed a 3D surface mesh constructed from manual kVCT contours by B-spline free-form deformation to generate optimal and smooth contours. Deformation was calculated by elastic image registration between kVCT and MVCT images. Data from ten head-and-neck cancer patients were considered and manual contours by three observers were included in both kVCT and MVCT images. A preliminary inter-observer variability analysis demonstrated the importance of contour propagation in tomotherapy application: a high variability was reported in MVCT parotid volume estimation (p = 0.0176, ANOVA test) and a larger uncertainty of MVCT contouring compared with kVCT was demonstrated by DICE and volume variability indices (Wilcoxon signed rank test, p < 10{sup -4} for both indices). The performance analysis of our method showed no significant differences between automatic and manual contours in terms of volumes (p > 0.05, in a multiple comparison Tukey test), center-of-mass distances (p = 0.3043, ANOVA test), DICE values (p = 0.1672, Wilcoxon signed rank test) and average and maximum symmetric distances (p = 0.2043, p = 0.8228 Wilcoxon signed rank tests). Results suggested that our contour propagation method could successfully substitute human contouring on MVCT images.

  14. Contouring variability of human- and deformable-generated contours in radiotherapy for prostate cancer

    International Nuclear Information System (INIS)

    Gardner, Stephen J; Wen, Ning; Kim, Jinkoo; Liu, Chang; Pradhan, Deepak; Aref, Ibrahim; Cattaneo, Richard II; Vance, Sean; Movsas, Benjamin; Chetty, Indrin J; Elshaikh, Mohamed A

    2015-01-01

    This study was designed to evaluate contouring variability of human-and deformable-generated contours on planning CT (PCT) and CBCT for ten patients with low-or intermediate-risk prostate cancer. For each patient in this study, five radiation oncologists contoured the prostate, bladder, and rectum, on one PCT dataset and five CBCT datasets. Consensus contours were generated using the STAPLE method in the CERR software package. Observer contours were compared to consensus contour, and contour metrics (Dice coefficient, Hausdorff distance, Contour Distance, Center-of-Mass [COM] Deviation) were calculated. In addition, the first day CBCT was registered to subsequent CBCT fractions (CBCTn: CBCT2–CBCT5) via B-spline Deformable Image Registration (DIR). Contours were transferred from CBCT1 to CBCTn via the deformation field, and contour metrics were calculated through comparison with consensus contours generated from human contour set. The average contour metrics for prostate contours on PCT and CBCT were as follows: Dice coefficient—0.892 (PCT), 0.872 (CBCT-Human), 0.824 (CBCT-Deformed); Hausdorff distance—4.75 mm (PCT), 5.22 mm (CBCT-Human), 5.94 mm (CBCT-Deformed); Contour Distance (overall contour)—1.41 mm (PCT), 1.66 mm (CBCT-Human), 2.30 mm (CBCT-Deformed); COM Deviation—2.01 mm (PCT), 2.78 mm (CBCT-Human), 3.45 mm (CBCT-Deformed). For human contours on PCT and CBCT, the difference in average Dice coefficient between PCT and CBCT (approx. 2%) and Hausdorff distance (approx. 0.5 mm) was small compared to the variation between observers for each patient (standard deviation in Dice coefficient of 5% and Hausdorff distance of 2.0 mm). However, additional contouring variation was found for the deformable-generated contours (approximately 5.0% decrease in Dice coefficient and 0.7 mm increase in Hausdorff distance relative to human-generated contours on CBCT). Though deformable contours provide a reasonable starting point for contouring

  15. The Development of Contour Interpolation: Evidence from Subjective Contours

    Science.gov (United States)

    Hadad, Bat-Sheva; Maurer, Daphne; Lewis, Terri L.

    2010-01-01

    Adults are skilled at perceiving subjective contours in regions without any local image information (e.g., [Ginsburg, 1975] and [Kanizsa, 1976]). Here we examined the development of this skill and the effect thereon of the support ratio (i.e., the ratio of the physically specified contours to the total contour length). Children (6-, 9-, and…

  16. Localization method of picking point of apple target based on smoothing contour symmetry axis algorithm%基于平滑轮廓对称轴法的苹果目标采摘点定位方法

    Institute of Scientific and Technical Information of China (English)

    王丹丹; 徐越; 宋怀波; 何东健

    2015-01-01

    果实采摘点的精确定位是采摘机器人必须解决的关键问题。鉴于苹果目标具有良好对称性的特点,利用转动惯量所具有的平移、旋转不变性及其在对称轴方向取得极值的特性,提出了一种基于轮廓对称轴法的苹果目标采摘点定位方法。为了解决分割后苹果目标边缘不够平滑而导致定位精度偏低的问题,提出了一种苹果目标轮廓平滑方法。为了验证算法的有效性,对随机选取的20幅无遮挡的单果苹果图像分别利用轮廓平滑和未进行轮廓平滑的算法进行试验,试验结果表明,未进行轮廓平滑算法的平均定位误差为20.678°,而轮廓平滑后算法平均定位误差为4.542°,比未进行轮廓平滑算法平均定位误差降低了78.035%,未进行轮廓平滑算法的平均运行时间为10.2 ms,而轮廓平滑后算法的平均运行时间为7.5 ms,比未进行轮廓平滑算法平均运行时间降低了25.839%,表明平滑轮廓算法可以提高定位精度和运算效率。利用平滑轮廓对称轴算法可以较好地找到苹果目标的对称轴并实现采摘点定位,表明将该方法应用于苹果目标的对称轴提取及采摘点定位是可行的。%The localization of picking points of fruits is one of the key problems for picking robots, and it is the first step of implementation of the picking task for picking robots. In view of a good symmetry of apples, and characteristics of shift, rotation invariance, and reaching the extreme values in symmetry axis direction which moment of inertia possesses, a new method based on a contour symmetry axis was proposed to locate the picking point of apples. In order to solve the problem of low localization accuracy which results from the rough edge of apples after segmentation, a method of smoothing contour algorithm was presented. The steps of the algorithm were as follow, first, the image was transformed from RGB color space into

  17. Curvature histogram features for retrieval of images of smooth 3D objects

    International Nuclear Information System (INIS)

    Zhdanov, I; Scherbakov, O; Potapov, A; Peterson, M

    2014-01-01

    We consider image features on the base of histograms of oriented gradients (HOG) with addition of contour curvature histogram (HOG-CH), and also compare it with results of known scale-invariant feature transform (SIFT) approach in application to retrieval of images of smooth 3D objects.

  18. Evaluating the impact of a Canadian national anatomy and radiology contouring boot camp for radiation oncology residents.

    Science.gov (United States)

    Jaswal, Jasbir; D'Souza, Leah; Johnson, Marjorie; Tay, KengYeow; Fung, Kevin; Nichols, Anthony; Landis, Mark; Leung, Eric; Kassam, Zahra; Willmore, Katherine; D'Souza, David; Sexton, Tracy; Palma, David A

    2015-03-15

    Radiation therapy treatment planning has advanced over the past 2 decades, with increased emphasis on 3-dimensional imaging for target and organ-at-risk (OAR) delineation. Recent studies suggest a need for improved resident instruction in this area. We developed and evaluated an intensive national educational course ("boot camp") designed to provide dedicated instruction in site-specific anatomy, radiology, and contouring using a multidisciplinary (MDT) approach. The anatomy and radiology contouring (ARC) boot camp was modeled after prior single-institution pilot studies and a needs-assessment survey. The boot camp incorporated joint lectures from radiation oncologists, anatomists, radiologists, and surgeons, with hands-on contouring instruction and small group interactive seminars using cadaveric prosections and correlative axial radiographs. Outcomes were evaluated using pretesting and posttesting, including anatomy/radiology multiple-choice questions (MCQ), timed contouring sessions (evaluated relative to a gold standard using Dice similarity metrics), and qualitative questions on satisfaction and perceived effectiveness. Analyses of pretest versus posttest scores were performed using nonparametric paired testing. Twenty-nine radiation oncology residents from 10 Canadian universities participated. As part of their current training, 29%, 75%, and 21% receive anatomy, radiology, and contouring instruction, respectively. On posttest scores, the MCQ knowledge scores improved significantly (pretest mean 60% vs posttest mean 80%, Pradiology in addition to enhancing their confidence and accuracy in contouring. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Male Body Contouring.

    Science.gov (United States)

    Singh, Babu; Keaney, Terrence; Rossi, Anthony M

    2015-09-01

    Men are increasingly turning to dermatologists and plastic surgeons to request procedures that correct or enhance physical features. With the advent of this emerging new patient population, alterations in preexisting aesthetic techniques, gender-specific uses of existing devices and overall approaches need to be revisited and adapted to obtain results that are suitable for the male patient. Recently, body contouring has become one of the most sought out procedures by men. Although the majority of clinical studies involving body contouring esthetics are performed with female patients, gains from such studies can be extrapolated to men. Body contouring can be broadly classified as non-invasive or invasive, depending on the modality used. Non-invasive contouring is most frequently performed with devices that target subcutaneous adipose with focused electrical or thermal energy, including low-level laser, cryolipolysis, ultrasonography, and radiofrequency. Invasive body contouring modalities useful for male body contouring include liposuction, pectoral and abdominal wall etching, jawline fillers, synthetic deoxycholic acid injections, and solid silicone implants. The purpose of this review is to bring attention to the unique aspects, strategies, and modalities used in aesthetic body contouring for the male patient.

  20. Fully automated left ventricular contour detection for gated radionuclide angiography, (1)

    International Nuclear Information System (INIS)

    Hosoba, Minoru; Wani, Hidenobu; Hiroe, Michiaki; Kusakabe, Kiyoko.

    1984-01-01

    A fully automated practical method has been developed to detect the left ventricular (LV) contour from gated pool images. Ejection fraction and volume curve can be computed accurately without operater variance. The characteristics of the method are summarized as follows: 1. Optimal design of the filter that works on Fourier domain, can be achieved to improve the signal to noise ratio. 2. New algorithm which use the cosine and sine transform images has been developed for the separating ventricle from atrium and defining center of LV. 3. Contrast enhancement by optimized square filter. 4. Radial profiles are generated from the center of LV and smoothed by fourth order Fourier series approximation. The crossing point with local threshold value searched from the center of the LV is defined as edge. 5. LV contour is obtained by conecting all the edge points defined on radial profiles by fitting them to Fourier function. (author)

  1. Material properties characterization of low carbon steel using TBW and PWHT techniques in smooth-contoured and U-shaped geometries

    International Nuclear Information System (INIS)

    Aloraier, Abdulkareem S.; Joshi, Suraj; Price, John W.H.; Alawadhi, Khaled

    2013-01-01

    This paper investigates the effects of the temper bead welding (TBW) technique and post weld heat treatment (PWHT) on mechanical properties of multi-layer welding on low carbon steel specimens using Charpy V-notch impact testing and tensile testing. Several samples of two different weld geometries, viz. (i) smooth-contoured, and (ii) U-shaped were made with multiple bead layers using both TBW and PWHT techniques. Impact testing showed that at room temperature and below, TBW gave an impact toughness in the Heat Affected Zone (HAZ) better than both PWHT and the parent material. At temperatures higher than the room temperature but below 60 °C, PWHT gave better impact toughness in the HAZ. Above 60 °C, both TBW and PWHT showed impact toughness lower than that of the parent material. In tensile testing, both TBW and PWHT weld metal specimens produced acceptable results; however, TBW gave yield and tensile strengths closer to that of the actual material than PWHT. -- Highlights: • Effects of post weld heat treatment (PWHT) and temper bead welding (TBW) on properties are tested. • Charpy V-notch impact and tensile testing was performed on multi-layer welding of low carbon steel. • At room temperature and below, TBW gave better impact toughness than both PWHT and parent material. • Above room temperature but below 60 °C, PWHT gave better impact toughness than TBW. • Above 60 °C, both TBW and PWHT showed impact toughness lower than that of parent material

  2. Visualization of Uncertain Contour Trees

    DEFF Research Database (Denmark)

    Kraus, Martin

    2010-01-01

    Contour trees can represent the topology of large volume data sets in a relatively compact, discrete data structure. However, the resulting trees often contain many thousands of nodes; thus, many graph drawing techniques fail to produce satisfactory results. Therefore, several visualization methods...... were proposed recently for the visualization of contour trees. Unfortunately, none of these techniques is able to handle uncertain contour trees although any uncertainty of the volume data inevitably results in partially uncertain contour trees. In this work, we visualize uncertain contour trees...... by combining the contour trees of two morphologically filtered versions of a volume data set, which represent the range of uncertainty. These two contour trees are combined and visualized within a single image such that a range of potential contour trees is represented by the resulting visualization. Thus...

  3. Fragmented esophageal smooth muscle contraction segments on high resolution manometry: a marker of esophageal hypomotility.

    Science.gov (United States)

    Porter, R F; Kumar, N; Drapekin, J E; Gyawali, C P

    2012-08-01

    Esophageal peristalsis consists of a chain of contracting striated and smooth muscle segments on high resolution manometry (HRM). We compared smooth muscle contraction segments in symptomatic subjects with reflux disease to healthy controls. High resolution manometry Clouse plots were analyzed in 110 subjects with reflux disease (50 ± 1.4 years, 51.5% women) and 15 controls (27 ± 2.1 years, 60.0% women). Using the 30 mmHg isobaric contour tool, sequences were designated fragmented if either smooth muscle contraction segment was absent or if the two smooth muscle segments were separated by a pressure trough, and failed if both smooth muscle contraction segments were absent. The discriminative value of contraction segment analysis was assessed. A total of 1115 swallows were analyzed (reflux group: 965, controls: 150). Reflux subjects had lower peak and averaged contraction amplitudes compared with controls (P value to HRM analysis. Specifically, fragmented smooth muscle contraction segments may be a marker of esophageal hypomotility. © 2012 Blackwell Publishing Ltd.

  4. Fairfax County Contours

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — This layer contains contours that were derived from the digital terrain model made up of irregularly spaced mass points and breaklines. The contours are 5 foot...

  5. Combining retraction edge lithography and plasma etching for arbitrary contour nanoridge fabrication

    Science.gov (United States)

    Zhao, Yiping; Jansen, Henri; de Boer, Meint; Berenschot, Erwin; Bouwes, Dominique; Gironès, Miriam; Huskens, Jurriaan; Tas, Niels

    2010-09-01

    Edge lithography in combination with fluorine-based plasma etching is employed to avoid the dependence on crystal orientation in single crystal silicon to create monolithic nanoridges with arbitrary contours. This is demonstrated by using a mask with circular structures and Si etching at cryogenic temperature with SF6+O2 plasma mixtures. Initially, the explored etch recipe was used with Cr as the masking material. Although nanoridges with perfect vertical sidewalls have been achieved, Cr causes severe sidewall roughness due to line edge roughness. Therefore, an SU-8 polymer is used instead. Although the SU-8 pattern definition needs further improvement, we demonstrate the possibility of fabricating Si nanoridges of arbitrary contours providing a width below 50 nm and a height between 25 and 500 nm with smooth surface finish. Artifacts in the ridge profile are observed and are mainly caused by the bird's beak phenomenon which is characteristic for the used LOCOS process.

  6. Evaluating the Impact of a Canadian National Anatomy and Radiology Contouring Boot Camp for Radiation Oncology Residents

    Energy Technology Data Exchange (ETDEWEB)

    Jaswal, Jasbir [Department of Radiation Oncology, London Health Sciences Centre, London, Ontario (Canada); D' Souza, Leah; Johnson, Marjorie [Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, Western University, London, Ontario (Canada); Tay, KengYeow [Department of Diagnostic Radiology, London Health Sciences, London, Ontario (Canada); Fung, Kevin; Nichols, Anthony [Department of Otolaryngology, Head & Neck Surgery, Victoria Hospital, London, Ontario (Canada); Landis, Mark [Department of Diagnostic Radiology, London Health Sciences, London, Ontario (Canada); Leung, Eric [Department of Radiation Oncology, London Health Sciences Centre, London, Ontario (Canada); Kassam, Zahra [Department of Diagnostic Radiology, St. Joseph' s Health Care London, London, Ontario (Canada); Willmore, Katherine [Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, Western University, London, Ontario (Canada); D' Souza, David; Sexton, Tracy [Department of Radiation Oncology, London Health Sciences Centre, London, Ontario (Canada); Palma, David A., E-mail: david.palma@lhsc.on.ca [Department of Radiation Oncology, London Health Sciences Centre, London, Ontario (Canada)

    2015-03-15

    Background: Radiation therapy treatment planning has advanced over the past 2 decades, with increased emphasis on 3-dimensional imaging for target and organ-at-risk (OAR) delineation. Recent studies suggest a need for improved resident instruction in this area. We developed and evaluated an intensive national educational course (“boot camp”) designed to provide dedicated instruction in site-specific anatomy, radiology, and contouring using a multidisciplinary (MDT) approach. Methods: The anatomy and radiology contouring (ARC) boot camp was modeled after prior single-institution pilot studies and a needs-assessment survey. The boot camp incorporated joint lectures from radiation oncologists, anatomists, radiologists, and surgeons, with hands-on contouring instruction and small group interactive seminars using cadaveric prosections and correlative axial radiographs. Outcomes were evaluated using pretesting and posttesting, including anatomy/radiology multiple-choice questions (MCQ), timed contouring sessions (evaluated relative to a gold standard using Dice similarity metrics), and qualitative questions on satisfaction and perceived effectiveness. Analyses of pretest versus posttest scores were performed using nonparametric paired testing. Results: Twenty-nine radiation oncology residents from 10 Canadian universities participated. As part of their current training, 29%, 75%, and 21% receive anatomy, radiology, and contouring instruction, respectively. On posttest scores, the MCQ knowledge scores improved significantly (pretest mean 60% vs posttest mean 80%, P<.001). Across all contoured structures, there was a 0.20 median improvement in students' average Dice score (P<.001). For individual structures, significant Dice improvements occurred in 10 structures. Residents self-reported an improved ability to contour OARs and interpret radiographs in all anatomic sites, 92% of students found the MDT format effective for their learning, and 93% found the boot camp

  7. Evaluating the Impact of a Canadian National Anatomy and Radiology Contouring Boot Camp for Radiation Oncology Residents

    International Nuclear Information System (INIS)

    Jaswal, Jasbir; D'Souza, Leah; Johnson, Marjorie; Tay, KengYeow; Fung, Kevin; Nichols, Anthony; Landis, Mark; Leung, Eric; Kassam, Zahra; Willmore, Katherine; D'Souza, David; Sexton, Tracy; Palma, David A.

    2015-01-01

    Background: Radiation therapy treatment planning has advanced over the past 2 decades, with increased emphasis on 3-dimensional imaging for target and organ-at-risk (OAR) delineation. Recent studies suggest a need for improved resident instruction in this area. We developed and evaluated an intensive national educational course (“boot camp”) designed to provide dedicated instruction in site-specific anatomy, radiology, and contouring using a multidisciplinary (MDT) approach. Methods: The anatomy and radiology contouring (ARC) boot camp was modeled after prior single-institution pilot studies and a needs-assessment survey. The boot camp incorporated joint lectures from radiation oncologists, anatomists, radiologists, and surgeons, with hands-on contouring instruction and small group interactive seminars using cadaveric prosections and correlative axial radiographs. Outcomes were evaluated using pretesting and posttesting, including anatomy/radiology multiple-choice questions (MCQ), timed contouring sessions (evaluated relative to a gold standard using Dice similarity metrics), and qualitative questions on satisfaction and perceived effectiveness. Analyses of pretest versus posttest scores were performed using nonparametric paired testing. Results: Twenty-nine radiation oncology residents from 10 Canadian universities participated. As part of their current training, 29%, 75%, and 21% receive anatomy, radiology, and contouring instruction, respectively. On posttest scores, the MCQ knowledge scores improved significantly (pretest mean 60% vs posttest mean 80%, P<.001). Across all contoured structures, there was a 0.20 median improvement in students' average Dice score (P<.001). For individual structures, significant Dice improvements occurred in 10 structures. Residents self-reported an improved ability to contour OARs and interpret radiographs in all anatomic sites, 92% of students found the MDT format effective for their learning, and 93% found the boot camp

  8. CONTOUR investigation launched

    Science.gov (United States)

    Showstack, Randy

    On 27 August, NASA Administrator Sean O'Keefe appointed a team to investigate the apparent loss of the Comet Nucleus Tour (CONTOUR) spacecraft, which stopped communicating with the mission control operations on 15 August.On that date, CONTOUR failed to communicate following the firing of its main engine that would take it out of its orbit around the Earth. Shortly afterwards, the mission team received telescope images from several observatories showing two objects traveling along the spacecraft's predicted path. Those objects could be CONTOUR, and part of the spacecraft that may have separated from it when the spacecraft's solid rocket motor fired.

  9. (Con)fusing contours

    NARCIS (Netherlands)

    Lier, R.J. van; Wit, T.C.J. de; Koning, A.R.

    2005-01-01

    We have created patterns in which illusory Kanizsa squares are positioned on top of a background grid of bars. When the illusory contours and physical contours are misaligned, the resulting percept appears to be rather confusing (van Lier et al, 2004 Perception 33 Supplement, 77). Observers often

  10. A lecture on lecturing.

    Science.gov (United States)

    Calnan, J

    1976-11-01

    There are major differences between a lecture and a paper for publication. Often the printed word is spoken at meetings, a kind of compulsive public reading which has robbed the lecturer of the chance of oratory and the audience of a little enjoyment. The simple fact is that although doctors read aloud badly (actors do this far better) most can learn to speak spontaneolsly and with animation; but this requires time and effort, both of which are donated in a miserly way. The successful lecturer is generous and considerate of his audience--a rare being at medical meetings.

  11. CMOS image sensor with contour enhancement

    Science.gov (United States)

    Meng, Liya; Lai, Xiaofeng; Chen, Kun; Yuan, Xianghui

    2010-10-01

    Imitating the signal acquisition and processing of vertebrate retina, a CMOS image sensor with bionic pre-processing circuit is designed. Integration of signal-process circuit on-chip can reduce the requirement of bandwidth and precision of the subsequent interface circuit, and simplify the design of the computer-vision system. This signal pre-processing circuit consists of adaptive photoreceptor, spatial filtering resistive network and Op-Amp calculation circuit. The adaptive photoreceptor unit with a dynamic range of approximately 100 dB has a good self-adaptability for the transient changes in light intensity instead of intensity level itself. Spatial low-pass filtering resistive network used to mimic the function of horizontal cell, is composed of the horizontal resistor (HRES) circuit and OTA (Operational Transconductance Amplifier) circuit. HRES circuit, imitating dendrite of the neuron cell, comprises of two series MOS transistors operated in weak inversion region. Appending two diode-connected n-channel transistors to a simple transconductance amplifier forms the OTA Op-Amp circuit, which provides stable bias voltage for the gate of MOS transistors in HRES circuit, while serves as an OTA voltage follower to provide input voltage for the network nodes. The Op-Amp calculation circuit with a simple two-stage Op-Amp achieves the image contour enhancing. By adjusting the bias voltage of the resistive network, the smoothing effect can be tuned to change the effect of image's contour enhancement. Simulations of cell circuit and 16×16 2D circuit array are implemented using CSMC 0.5μm DPTM CMOS process.

  12. Residual stress measurement of EB-welded plates with contour method. Part 2: FEM analysis of contour profiles

    International Nuclear Information System (INIS)

    Romppanen, A.-J.; Immonen, E.

    2013-12-01

    The residual stresses formed as a result of Electronic Beam welding (EB-welding) in copper are investigated by Posiva. In the present study, residual stresses of EB-welded copper plates were studied with contour method. In the method eleven copper plates (X436 - X440 and X453 - X458) were cut in half with wire electric discharge machining (EDM) after which the deformation due to stress relaxation was measured with coordinate measurement system. The measured data was then used as boundary displacement data for the FEM analyses, in which the corresponding residual stresses were calculated. Before giving the corresponding displacement boundary conditions to the FE models, the deformation data was processed and smoothed appropriately. The residual stress levels of the copper plates were found to be around 40 - 55 MPa at maximum. This corresponds to other reported residual stress measurements and current state of knowledge with this material in Posiva. (orig.)

  13. High Resolution Elevation Contours

    Data.gov (United States)

    Minnesota Department of Natural Resources — This dataset contains contours generated from high resolution data sources such as LiDAR. Generally speaking this data is 2 foot or less contour interval.

  14. Tagged Vector Contour (TVC)

    Data.gov (United States)

    Kansas Data Access and Support Center — The Kansas Tagged Vector Contour (TVC) dataset consists of digitized contours from the 7.5 minute topographic quadrangle maps. Coverage for the state is incomplete....

  15. Exploring Tablet PC Lectures: Lecturer Experiences and Student Perceptions in Biomedicine

    Science.gov (United States)

    Choate, Julia; Kotsanas, George; Dawson, Phillip

    2014-01-01

    Lecturers using tablet PCs with specialised pens can utilise real-time changes in lecture delivery via digital inking. We investigated student perceptions and lecturer experiences of tablet PC lectures in large-enrolment biomedicine subjects. Lecturers used PowerPoint or Classroom Presenter software for lecture preparation and in-lecture pen-based…

  16. Ocean Sediment Thickness Contours

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Ocean sediment thickness contours in 200 meter intervals for water depths ranging from 0 - 18,000 meters. These contours were derived from a global sediment...

  17. Automated consensus contour building for prostate MRI.

    Science.gov (United States)

    Khalvati, Farzad

    2014-01-01

    Inter-observer variability is the lack of agreement among clinicians in contouring a given organ or tumour in a medical image. The variability in medical image contouring is a source of uncertainty in radiation treatment planning. Consensus contour of a given case, which was proposed to reduce the variability, is generated by combining the manually generated contours of several clinicians. However, having access to several clinicians (e.g., radiation oncologists) to generate a consensus contour for one patient is costly. This paper presents an algorithm that automatically generates a consensus contour for a given case using the atlases of different clinicians. The algorithm was applied to prostate MR images of 15 patients manually contoured by 5 clinicians. The automatic consensus contours were compared to manual consensus contours where a median Dice similarity coefficient (DSC) of 88% was achieved.

  18. Pitch contour impairment in congenital amusia: New insights from the Self-paced Audio-visual Contour Task (SACT).

    Science.gov (United States)

    Lu, Xuejing; Sun, Yanan; Ho, Hao Tam; Thompson, William Forde

    2017-01-01

    Individuals with congenital amusia usually exhibit impairments in melodic contour processing when asked to compare pairs of melodies that may or may not be identical to one another. However, it is unclear whether the impairment observed in contour processing is caused by an impairment of pitch discrimination, or is a consequence of poor pitch memory. To help resolve this ambiguity, we designed a novel Self-paced Audio-visual Contour Task (SACT) that evaluates sensitivity to contour while placing minimal burden on memory. In this task, participants control the pace of an auditory contour that is simultaneously accompanied by a visual contour, and they are asked to judge whether the two contours are congruent or incongruent. In Experiment 1, melodic contours varying in pitch were presented with a series of dots that varied in spatial height. Amusics exhibited reduced sensitivity to audio-visual congruency in comparison to control participants. To exclude the possibility that the impairment arises from a general deficit in cross-modal mapping, Experiment 2 examined sensitivity to cross-modal mapping for two other auditory dimensions: timbral brightness and loudness. Amusics and controls were significantly more sensitive to large than small contour changes, and to changes in loudness than changes in timbre. However, there were no group differences in cross-modal mapping, suggesting that individuals with congenital amusia can comprehend spatial representations of acoustic information. Taken together, the findings indicate that pitch contour processing in congenital amusia remains impaired even when pitch memory is relatively unburdened.

  19. CT urography: segmentation of urinary bladder using CLASS with local contour refinement

    International Nuclear Information System (INIS)

    Cha, Kenny; Hadjiiski, Lubomir; Chan, Heang-Ping; Caoili, Elaine M; Cohan, Richard H; Zhou, Chuan

    2014-01-01

    We are developing a computerized system for bladder segmentation on CT urography (CTU), as a critical component for computer-aided detection of bladder cancer. The presence of regions filled with intravenous contrast and without contrast presents a challenge for bladder segmentation. Previously, we proposed a conjoint level set analysis and segmentation system (CLASS). In case the bladder is partially filled with contrast, CLASS segments the non-contrast (NC) region and the contrast-filled (C) region separately and automatically conjoins the NC and C region contours; however, inaccuracies in the NC and C region contours may cause the conjoint contour to exclude portions of the bladder. To alleviate this problem, we implemented a local contour refinement (LCR) method that exploits model-guided refinement (MGR) and energy-driven wavefront propagation (EDWP). MGR propagates the C region contours if the level set propagation in the C region stops prematurely due to substantial non-uniformity of the contrast. EDWP with regularized energies further propagates the conjoint contours to the correct bladder boundary. EDWP uses changes in energies, smoothness criteria of the contour, and previous slice contour to determine when to stop the propagation, following decision rules derived from training. A data set of 173 cases was collected for this study: 81 cases in the training set (42 lesions, 21 wall thickenings, 18 normal bladders) and 92 cases in the test set (43 lesions, 36 wall thickenings, 13 normal bladders). For all cases, 3D hand segmented contours were obtained as reference standard and used for the evaluation of the computerized segmentation accuracy. For CLASS with LCR, the average volume intersection ratio, average volume error, absolute average volume error, average minimum distance and Jaccard index were 84.2 ± 11.4%, 8.2 ± 17.4%, 13.0 ± 14.1%, 3.5 ± 1.9 mm, 78.8 ± 11.6%, respectively, for the training set and 78.0 ± 14.7%, 16.4 ± 16.9%, 18.2 ± 15

  20. Contour-Based Corner Detection and Classification by Using Mean Projection Transform

    Directory of Open Access Journals (Sweden)

    Seyed Mostafa Mousavi Kahaki

    2014-02-01

    Full Text Available Image corner detection is a fundamental task in computer vision. Many applications require reliable detectors to accurately detect corner points, commonly achieved by using image contour information. The curvature definition is sensitive to local variation and edge aliasing, and available smoothing methods are not sufficient to address these problems properly. Hence, we propose Mean Projection Transform (MPT as a corner classifier and parabolic fit approximation to form a robust detector. The first step is to extract corner candidates using MPT based on the integral properties of the local contours in both the horizontal and vertical directions. Then, an approximation of the parabolic fit is calculated to localize the candidate corner points. The proposed method presents fewer false-positive (FP and false-negative (FN points compared with recent standard corner detection techniques, especially in comparison with curvature scale space (CSS methods. Moreover, a new evaluation metric, called accuracy of repeatability (AR, is introduced. AR combines repeatability and the localization error (Le for finding the probability of correct detection in the target image. The output results exhibit better repeatability, localization, and AR for the detected points compared with the criteria in original and transformed images.

  1. Pitch contour impairment in congenital amusia: New insights from the Self-paced Audio-visual Contour Task (SACT.

    Directory of Open Access Journals (Sweden)

    Xuejing Lu

    Full Text Available Individuals with congenital amusia usually exhibit impairments in melodic contour processing when asked to compare pairs of melodies that may or may not be identical to one another. However, it is unclear whether the impairment observed in contour processing is caused by an impairment of pitch discrimination, or is a consequence of poor pitch memory. To help resolve this ambiguity, we designed a novel Self-paced Audio-visual Contour Task (SACT that evaluates sensitivity to contour while placing minimal burden on memory. In this task, participants control the pace of an auditory contour that is simultaneously accompanied by a visual contour, and they are asked to judge whether the two contours are congruent or incongruent. In Experiment 1, melodic contours varying in pitch were presented with a series of dots that varied in spatial height. Amusics exhibited reduced sensitivity to audio-visual congruency in comparison to control participants. To exclude the possibility that the impairment arises from a general deficit in cross-modal mapping, Experiment 2 examined sensitivity to cross-modal mapping for two other auditory dimensions: timbral brightness and loudness. Amusics and controls were significantly more sensitive to large than small contour changes, and to changes in loudness than changes in timbre. However, there were no group differences in cross-modal mapping, suggesting that individuals with congenital amusia can comprehend spatial representations of acoustic information. Taken together, the findings indicate that pitch contour processing in congenital amusia remains impaired even when pitch memory is relatively unburdened.

  2. Digital extraction of interference fringe contours

    International Nuclear Information System (INIS)

    Mastin, G.A.; Ghiglia, D.C.

    1985-01-01

    Two basic techniques for extracting interferogram contours have been discussed. The first is a global contour extracton technique based on the fast Fourier transform. The second extracts individual contours with a thinning algorithm using logical neighborhood transformations

  3. Image Interpolation with Geometric Contour Stencils

    Directory of Open Access Journals (Sweden)

    Pascal Getreuer

    2011-09-01

    Full Text Available We consider the image interpolation problem where given an image vm,n with uniformly-sampled pixels vm,n and point spread function h, the goal is to find function u(x,y satisfying vm,n = (h*u(m,n for all m,n in Z. This article improves upon the IPOL article Image Interpolation with Contour Stencils. In the previous work, contour stencils are used to estimate the image contours locally as short line segments. This article begins with a continuous formulation of total variation integrated over a collection of curves and defines contour stencils as a consistent discretization. This discretization is more reliable than the previous approach and can effectively distinguish contours that are locally shaped like lines, curves, corners, and circles. These improved contour stencils sense more of the geometry in the image. Interpolation is performed using an extension of the method described in the previous article. Using the improved contour stencils, there is an increase in image quality while maintaining similar computational efficiency.

  4. Spectrally accurate contour dynamics

    International Nuclear Information System (INIS)

    Van Buskirk, R.D.; Marcus, P.S.

    1994-01-01

    We present an exponentially accurate boundary integral method for calculation the equilibria and dynamics of piece-wise constant distributions of potential vorticity. The method represents contours of potential vorticity as a spectral sum and solves the Biot-Savart equation for the velocity by spectrally evaluating a desingularized contour integral. We use the technique in both an initial-value code and a newton continuation method. Our methods are tested by comparing the numerical solutions with known analytic results, and it is shown that for the same amount of computational work our spectral methods are more accurate than other contour dynamics methods currently in use

  5. The influence of automation on tumor contouring

    NARCIS (Netherlands)

    Aselmaa, A.; van Herk, Marcel; Song, Y.; Goossens, R.H.M.; Laprie, Anne

    2017-01-01

    Fully or semi-automatic contouring tools are increasingly being used in the tumor contouring task for radiotherapy. While the fully automatic contouring tools have not reached sufficient efficiency, the semi-automatic contouring tools balance more effectively between the human interaction and

  6. Memory for Lectures: How Lecture Format Impacts the Learning Experience.

    Science.gov (United States)

    Varao-Sousa, Trish L; Kingstone, Alan

    2015-01-01

    The present study investigated what impact the presentation style of a classroom lecture has on memory, mind wandering, and the subjective factors of interest and motivation. We examined if having a professor lecturing live versus on video alters the learning experience of the students in the classroom. During the lectures, students were asked to report mind wandering and later complete a memory test. The lecture format was manipulated such that all the students received two lectures, one live and one a pre-recorded video. Results indicate that lecture format affected memory performance but not mind wandering, with enhanced memory in the live lectures. Additionally, students reported greater interest and motivation in the live lectures. Given that a single change to the classroom environment, professor presence, impacted memory performance, as well as motivation and interest, the present results have several key implications for technology-based integrations into higher education classrooms.

  7. Enhancement of Afterimage Colors by Surrounding Contours

    Directory of Open Access Journals (Sweden)

    Takao Sato

    2011-05-01

    Full Text Available Presenting luminance contours surrounding the adapted areas in test phase enhances color afterimages in both duration and color appearance. The presence of surrounding contour is crucial to some color phenomenon such as van Lier's afterimage, but the contour-effect itself has not been seriously examined. In this paper, we compared the contour-effect to color afterimages and to actually colored patches to examine the nature of color information subserving color-aftereffect. In the experiment, observers were adapted for 1 sec to a small colored square (red, green, yellow, or blue presented on a gray background. Then, a test field either with or without surrounding contour was presented. Observers matched the color of a test-patch located near the afterimage to the color of afterimage. It was found that the saturation of negative afterimage was almost doubled by the presence of surrounding contours. There was no effect of luminance contrast or polarity of contours. In contrast, no enhancement of saturation by surrounding contours was observed for actually colored patches even though the colors of patches were equalized to that of afterimage without contours. This dissociation in the contour-effect demonstrates the crucial difference between the color information for aftereffects and for ordinary bottom-up color perception.

  8. Automatic media-adventitia IVUS image segmentation based on sparse representation framework and dynamic directional active contour model.

    Science.gov (United States)

    Zakeri, Fahimeh Sadat; Setarehdan, Seyed Kamaledin; Norouzi, Somayye

    2017-10-01

    Segmentation of the arterial wall boundaries from intravascular ultrasound images is an important image processing task in order to quantify arterial wall characteristics such as shape, area, thickness and eccentricity. Since manual segmentation of these boundaries is a laborious and time consuming procedure, many researchers attempted to develop (semi-) automatic segmentation techniques as a powerful tool for educational and clinical purposes in the past but as yet there is no any clinically approved method in the market. This paper presents a deterministic-statistical strategy for automatic media-adventitia border detection by a fourfold algorithm. First, a smoothed initial contour is extracted based on the classification in the sparse representation framework which is combined with the dynamic directional convolution vector field. Next, an active contour model is utilized for the propagation of the initial contour toward the interested borders. Finally, the extracted contour is refined in the leakage, side branch openings and calcification regions based on the image texture patterns. The performance of the proposed algorithm is evaluated by comparing the results to those manually traced borders by an expert on 312 different IVUS images obtained from four different patients. The statistical analysis of the results demonstrates the efficiency of the proposed method in the media-adventitia border detection with enough consistency in the leakage and calcification regions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Memory for Lectures: How Lecture Format Impacts the Learning Experience.

    Directory of Open Access Journals (Sweden)

    Trish L Varao-Sousa

    Full Text Available The present study investigated what impact the presentation style of a classroom lecture has on memory, mind wandering, and the subjective factors of interest and motivation. We examined if having a professor lecturing live versus on video alters the learning experience of the students in the classroom. During the lectures, students were asked to report mind wandering and later complete a memory test. The lecture format was manipulated such that all the students received two lectures, one live and one a pre-recorded video. Results indicate that lecture format affected memory performance but not mind wandering, with enhanced memory in the live lectures. Additionally, students reported greater interest and motivation in the live lectures. Given that a single change to the classroom environment, professor presence, impacted memory performance, as well as motivation and interest, the present results have several key implications for technology-based integrations into higher education classrooms.

  10. Anatomical contouring variability in thoracic organs at risk

    Energy Technology Data Exchange (ETDEWEB)

    McCall, Ross, E-mail: rmccall86@gmail.com [Medical Dosimetry Program, University of Wisconsin, La Crosse, WI (United States); MacLennan, Grayden; Taylor, Matthew; Lenards, Nishele [Medical Dosimetry Program, University of Wisconsin, La Crosse, WI (United States); Nelms, Benjamin E. [Canis Lupus LLC, Madison, WI (United States); Koshy, Matthew; Lemons, Jeffrey [Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL (United States); Hunzeker, Ashley [Medical Dosimetry Program, University of Wisconsin, La Crosse, WI (United States)

    2016-01-01

    The purpose of this study was to determine whether contouring thoracic organs at risk was consistent among medical dosimetrists and to identify how trends in dosimetrist's education and experience affected contouring accuracy. Qualitative and quantitative methods were used to contextualize the raw data that were obtained. A total of 3 different computed tomography (CT) data sets were provided to medical dosimetrists (N = 13) across 5 different institutions. The medical dosimetrists were directed to contour the lungs, heart, spinal cord, and esophagus. The medical dosimetrists were instructed to contour in line with their institutional standards and were allowed to use any contouring tool or technique that they would traditionally use. The contours from each medical dosimetrist were evaluated against “gold standard” contours drawn and validated by 2 radiation oncology physicians. The dosimetrist-derived contours were evaluated against the gold standard using both a Dice coefficient method and a penalty-based metric scoring system. A short survey was also completed by each medical dosimetrist to evaluate their individual contouring experience. There was no significant variation in the contouring consistency of the lungs and spinal cord. Intradosimetrist contouring was consistent for those who contoured the esophagus and heart correctly; however, medical dosimetrists with a poor metric score showed erratic and inconsistent methods of contouring.

  11. An improved spatial contour tree constructed method

    Science.gov (United States)

    Zheng, Yi; Zhang, Ling; Guilbert, Eric; Long, Yi

    2018-05-01

    Contours are important data to delineate the landform on a map. A contour tree provides an object-oriented description of landforms and can be used to enrich the topological information. The traditional contour tree is used to store topological relationships between contours in a hierarchical structure and allows for the identification of eminences and depressions as sets of nested contours. This research proposes an improved contour tree so-called spatial contour tree that contains not only the topological but also the geometric information. It can be regarded as a terrain skeleton in 3-dimention, and it is established based on the spatial nodes of contours which have the latitude, longitude and elevation information. The spatial contour tree is built by connecting spatial nodes from low to high elevation for a positive landform, and from high to low elevation for a negative landform to form a hierarchical structure. The connection between two spatial nodes can provide the real distance and direction as a Euclidean vector in 3-dimention. In this paper, the construction method is tested in the experiment, and the results are discussed. The proposed hierarchical structure is in 3-demintion and can show the skeleton inside a terrain. The structure, where all nodes have geo-information, can be used to distinguish different landforms and applied for contour generalization with consideration of geographic characteristics.

  12. Automatic re-contouring in 4D radiotherapy

    International Nuclear Information System (INIS)

    Lu, Weiguo; Olivera, Gustavo H; Chen, Quan; Chen, Ming-Li; Ruchala, Kenneth J

    2006-01-01

    Delineating regions of interest (ROIs) on each phase of four-dimensional (4D) computed tomography (CT) images is an essential step for 4D radiotherapy. The requirement of manual phase-by-phase contouring prohibits the routine use of 4D radiotherapy. This paper develops an automatic re-contouring algorithm that combines techniques of deformable registration and surface construction. ROIs are manually contoured slice-by-slice in the reference phase image. A reference surface is constructed based on these reference contours using a triangulated surface construction technique. The deformable registration technique provides the voxel-to-voxel mapping between the reference phase and the test phase. The vertices of the reference surface are displaced in accordance with the deformation map, resulting in a deformed surface. The new contours are reconstructed by cutting the deformed surface slice-by-slice along the transversal, sagittal or coronal direction. Since both the inputs and outputs of our automatic re-contouring algorithm are contours, it is relatively easy to cope with any treatment planning system. We tested our automatic re-contouring algorithm using a deformable phantom and 4D CT images of six lung cancer patients. The proposed algorithm is validated by visual inspections and quantitative comparisons of the automatic re-contours with both the gold standard segmentations and the manual contours. Based on the automatic delineated ROIs, changes of tumour and sensitive structures during respiration are quantitatively analysed. This algorithm could also be used to re-contour daily images for treatment evaluation and adaptive radiotherapy

  13. Correlation of surface contour, optoelectronic and spectroscopic properties of Cu(In,Ga)Se{sub 2} by SNOM and AFM

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, Oliver; Heise, Stephan J.; Brueggemann, Rudolf; Meessen, Max; Bauer, Gottfried H. [Institute of Physics, Carl von Ossietzky University Oldenburg (Germany); Witte, Wolfram; Hariskos, Dimitrios [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung Baden-Wuerttemberg (ZSW), Stuttgart (Germany)

    2012-07-01

    Chalcopyrite absorbers exhibit local fluctuations of structural, optical and optoelectronic properties. We study the correlation of the surface contour and the local properties such as the integrated photoluminescence (PL) yield and the splitting of the quasi-Fermi levels in a Cu(In,Ga)Se{sub 2}-based thin-film system at room temperature by AFM and spatially resolved PL measurements at the identical position with a scanning near-field optical microscope (SNOM). The Cu(In,Ga)Se{sub 2} layer is deposited on glass, etched with bromine-methanol to smooth the surface for a more homogeneous incoupling of laser light, and passivated with cadmium sulfide. Our measurements reveal a high structural correlation between surface contour, integrated PL yield and quasi-Fermi level splitting. Additionally, we observe trenches in the surface contour which correspond to a dip or to a peak in the splitting of the quasi-Fermi levels and integrated PL yield. Furthermore some trenches show spectral variation of the PL compared to their direct environment. We discuss these observations with respect to the optoelectronic property and the composition of the absorber.

  14. Technique of experimental measurements of the optical thickness of a pulse discharge plasma channel in water on a contour reabsorption lines of hydrogen Hα

    Directory of Open Access Journals (Sweden)

    O. A. Fedorovich

    2010-03-01

    Full Text Available In this work the results of development and application of the technique of experimental definition of optical thickness (τ of the pulse discharge plasma channel in water which are based on the distribution of radiation intensities on contour reabsorption lines of hydrogen Ha (656.3 nm are given. Optical thickness of continues spectrum was defined by extrapolation of intensities in far wing of contour reabsorption lines of hydrogen Ha, where t value did not vary any more, and the line smoothly transferred in continuous spectrum. The atomic concentration Na, received on a method of definition of t on a contour reabsorption lines of hydrogen Ha., agreed with calculation obtained from the equation of the plasma state. The recommendations on the correct definition of optical thickness of plasma of pulse discharge in liquids are given.

  15. Drawing Contour Trees in the Plane.

    Science.gov (United States)

    Heine, C; Schneider, D; Carr, Hamish; Scheuermann, G

    2011-11-01

    The contour tree compactly describes scalar field topology. From the viewpoint of graph drawing, it is a tree with attributes at vertices and optionally on edges. Standard tree drawing algorithms emphasize structural properties of the tree and neglect the attributes. Applying known techniques to convey this information proves hard and sometimes even impossible. We present several adaptions of popular graph drawing approaches to the problem of contour tree drawing and evaluate them. We identify five esthetic criteria for drawing contour trees and present a novel algorithm for drawing contour trees in the plane that satisfies four of these criteria. Our implementation is fast and effective for contour tree sizes usually used in interactive systems (around 100 branches) and also produces readable pictures for larger trees, as is shown for an 800 branch example.

  16. Live lecture versus video-recorded lecture: are students voting with their feet?

    Science.gov (United States)

    Cardall, Scott; Krupat, Edward; Ulrich, Michael

    2008-12-01

    In light of educators' concerns that lecture attendance in medical school has declined, the authors sought to assess students' perceptions, evaluations, and motivations concerning live lectures compared with accelerated, video-recorded lectures viewed online. The authors performed a cross-sectional survey study of all first- and second-year students at Harvard Medical School. Respondents answered questions regarding their lecture attendance; use of class and personal time; use of accelerated, video-recorded lectures; and reasons for viewing video-recorded and live lectures. Other questions asked students to compare how well live and video-recorded lectures satisfied learning goals. Of the 353 students who received questionnaires, 204 (58%) returned responses. Collectively, students indicated watching 57.2% of lectures live, 29.4% recorded, and 3.8% using both methods. All students have watched recorded lectures, and most (88.5%) have used video-accelerating technologies. When using accelerated, video-recorded lecture as opposed to attending lecture, students felt they were more likely to increase their speed of knowledge acquisition (79.3% of students), look up additional information (67.7%), stay focused (64.8%), and learn more (63.7%). Live attendance remains the predominant method for viewing lectures. However, students find accelerated, video-recorded lectures equally or more valuable. Although educators may be uncomfortable with the fundamental change in the learning process represented by video-recorded lecture use, students' responses indicate that their decisions to attend lectures or view recorded lectures are motivated primarily by a desire to satisfy their professional goals. A challenge remains for educators to incorporate technologies students find useful while creating an interactive learning culture.

  17. Visualizing Contour Trees within Histograms

    DEFF Research Database (Denmark)

    Kraus, Martin

    2010-01-01

    Many of the topological features of the isosurfaces of a scalar volume field can be compactly represented by its contour tree. Unfortunately, the contour trees of most real-world volume data sets are too complex to be visualized by dot-and-line diagrams. Therefore, we propose a new visualization...... that is suitable for large contour trees and efficiently conveys the topological structure of the most important isosurface components. This visualization is integrated into a histogram of the volume data; thus, it offers strictly more information than a traditional histogram. We present algorithms...... to automatically compute the graph layout and to calculate appropriate approximations of the contour tree and the surface area of the relevant isosurface components. The benefits of this new visualization are demonstrated with the help of several publicly available volume data sets....

  18. Restoration of an object from its complex cross sections and surface smoothing of the object

    International Nuclear Information System (INIS)

    Agui, Takeshi; Arai, Kiyoshi; Nakajima, Masayuki

    1990-01-01

    In clinical medicine, restoring the surface of a three-dimensional object from its set of parallel cross sections obtained by CT or MRI is useful in diagnoses. A method of connecting a pair of contours on neighboring cross sections to each other by triangular patches is generally used for this restoration. This method, however, has the complexity of triangulation algorithm, and requires the numerous quantity of calculations when surface smoothing is executed. In our new method, the positions of sampling points are expressed in cylindrical coordinates. Sampling points including auxiliary points are extracted and connected using simple algorithm. Surface smoothing is executed by moving sampling points. This method extends the application scope of restoring objects by triangulation. (author)

  19. Orientation-crowding within contours.

    Science.gov (United States)

    Glen, James C; Dakin, Steven C

    2013-07-15

    We examined how crowding (the breakdown of object recognition in the periphery caused by interference from "clutter") depends on the global arrangement of target and distracting flanker elements. Specifically we probed orientation discrimination using a near-vertical target Gabor flanked by two vertical distractor Gabors (one above and one below the target). By applying variable (opposite-sign) horizontal offsets to the positions of the two flankers we arranged the elements so that on some trials they formed contours with the target and on others they did not. While the presence of flankers generally elevated orientation discrimination thresholds for the target we observe maximal crowding not when flanker and targets were co-aligned but when a small spatial offset was applied to flanker location, so that contours formed between flanker and targets only when the target orientation was cued. We also report that observers' orientation judgments are biased, with target orientation appearing either attracted or repulsed by the global/contour orientation. A second experiment reveals that the sign of this effect is dependent both on observer and on eccentricity. In general, the magnitude of repulsion is reduced with eccentricity but whether this becomes attraction (of element orientation to contour orientation) is dependent on observer. We note however that across observers and eccentricities, the magnitude of repulsion correlates positively with the amount of release from crowding observed with co-aligned targets and flankers, supporting the notion of fluctuating bias as the basis for elevated crowding within contours.

  20. Development of a contour meter

    International Nuclear Information System (INIS)

    Andrada C, F.A.; Sanz, D.E.

    2006-01-01

    The dosimetric calculation in patients that receive radiotherapy treatment it requires the one knowledge of the geometry of some anatomical portions, which differs from a patient to another. Making reference to the specific case of mammary neoplasia, one of the measurements that is carried out on the patient is the acquisition of the contour of the breast, which is determined from a point marked on the breastbone until another point marked on the lateral of the thorax, below the armpit, with the patient located in the irradiation position. This measurement is carried out with the help of a mechanical contour meter that is a device conformed by a series of wires with a polymeric coating, which support on the breast of the patient and it reproduces its form. Then it is transported in the more careful possible form on a paper and the contour is traced with a tracer one. The geometric error associated to this procedure is of ±1 cm, which is sensitive of being reduced. The present work finds its motivation in the patient's radiological protection radiotherapy. The maximum error in dose allowed in radiotherapeutic treatments is 5%. It would be increase the precision and with it to optimize the treatment received by the patient, reducing the error in the acquisition process of the mammary contour. With this objective, a digital device is designed whose operation is based in the application of a spatial transformation on a picture of the mammary contour, which corrects the geometric distortion introduced in the process of the photographic acquisition. An algorithm that allows to obtain a front image (without distortion) of the plane of the contour was developed. A software tool especially developed carries out the processing of the digital images. The maximum geometric error detected in the validation process is 2 mm located on a small portion of the contour. (Author)

  1. A Method for Denoising Image Contours

    Directory of Open Access Journals (Sweden)

    Ovidiu COSMA

    2017-12-01

    Full Text Available The edge detection techniques have to compromise between sensitivity and noise. In order for the main contours to be uninterrupted, the level of sensitivity has to be raised, which however has the negative effect of producing a multitude of insignificant contours (noise. This article proposes a method of removing this noise, which acts directly on the binary representation of the image contours.

  2. Five Lectures on Photosynthesis

    International Nuclear Information System (INIS)

    Broda, E.

    1979-01-01

    These five lectures were held by E. Broda during the International Symposium on Alternative Energies, in September 1979. Lecture 1 – The Great Physicists and Photosynthesis; Lecture 2 – The Influence of Photosynthesis on the Biosphere. Past, Present and Future; Lecture 3 – The Origin of Photosynthesis; Lecture 4 – The Evolution from Photosynthetic Bacteria to Plants; Lecture 5 – Respiration and Photorespiration. (nowak)

  3. CANDU lectures

    International Nuclear Information System (INIS)

    Rouben, B.

    1984-06-01

    This document is a compilation of notes prepared for two lectures given by the author in the winter of 1983 at the Institut de Genie Nucleaire, Ecole Polytechnique, Montreal. The first lecture gives a physical description of the CANDU reactor core: the nuclear lattice, the reactivity mechanisms, their functions and properties. This lecture also covers various aspects of reactor core physics and describes different calculational methods available. The second lecture studies the numerous facets of fuel management in CANDU reactors. The important variables in fuel management, and the rules guiding the refuelling strategy, are presented and illustrated by means of results obtained for the CANDU 600

  4. Development of a CONTOUR-METER

    International Nuclear Information System (INIS)

    Andrada Contardi, F.A.

    2004-01-01

    Dose calculation in patients undergoing radiotherapy treatments requires the knowledge of their anatomical geometry.Making reference to the specific case of breast cancer, one of the measurement that are made on the patients is the acquisition of the breast's contour, determined in an axial plane from a point marked on the breastbone until another point marked on the thorax side under the armpit.This measurement is normally made with a mechanic contour-meter: a device formed by a series of plastic-covered wires designed to be applied on the patient's skin copying the breast contour after it deformation.The geometrical error associated with this procedure is ± 1 cm. The precision of the dose calculation could be increased acquiring a breast contour more accurate.This objective was achieved developing a method based on breast images from a digital camera.The algorithms to obtain an axial-plane image of the contour from digital photographs taken from arbitrary positions were developed.A geometric transformation is applied to the photograph to correct for perspective distortions, obtaining a frontal - undistorted image (axial-plane image).A software tool to make all the image processing was developed under MatLab.The maximum geometrical error detected during the validation of the process was 2 mm [es

  5. The Web-Lecture - a viable alternative to the traditional lecture format?

    Science.gov (United States)

    Meibom, S.

    2004-12-01

    Educational research shows that students learn best in an environment with emphasis on teamwork, problem-solving, and hands-on experience. Still professors spend the majority of their time with students in the traditional lecture-hall setting where the combination of large classes and limited time prevents sufficient student-teacher interaction to foster an active learning environment. Can modern computer technology be used to provide "lecture-type" information to students via the World Wide Web? If so, will that help professors make better and/or different use of their scheduled time with the students? Answering these questions was the main motivation for the Extra-Solar Planet Project. The Extra-Solar Planet Project was designed to test the effectiveness of a lecture available to the student on the World Wide Web (Web-Lecture) and to engage the students in an active learning environment were their use the information presented in the Web-Lecture. The topic of the Web-Lecture was detection of extra-solar planets and the project was implemented into an introductory astronomy course at University of Wisconsin Madison in the spring of 2004. The Web-Lecture was designed to give an interactive presentation of synchronized video, audio and lecture notes. It was created using the eTEACH software developed at the University of Wisconsin Madison School of Engineering. In my talk, I will describe the project, show excerpts of the Web-Lecture, and present assessments of student learning and results of student evaluations of the web-lecture format.

  6. Contours - MO 2012 Greene County 5ft Contours (SHP)

    Data.gov (United States)

    NSGIC State | GIS Inventory — 5ft cartographic contour file for Greene County, Missouri. This file was created using the elevation data from the 2011 LiDAR flight. It includes indexes for 10, 25,...

  7. Vocal intensity in lecturers: Results of measurements conducted during lecture sessions

    Directory of Open Access Journals (Sweden)

    Witold Mikulski

    2013-12-01

    Full Text Available Background: Occupational voice users (inter alia: lecturers speak with different levels of vocal intensity. Speakers adjust this intensity knowingly (e.g. to underline the importance of fragments of the speech or unknowingly. The unknown adjustment of voice intensity occurs e.g. in the presence of high acoustic background noise (so-called Lombard effect, but it also results from many other factors: hearing loss, construction of the vocal tract, habits and others. The aim of the article is to confirm the thesis that in similar conditions of acoustic properties of the room different lecturers speak with different levels of vocal intensity. Materials and Methods: The study was conducted in a group of 10 lecturers in the same conference room. A-weighted sound pressure level determined at 1 m from the lecturer's mouth was adopted as a parameter defining the intensity of the lecturer's voice. The levels of all lecturers' voice intensity were compared and evaluated according to the criteria defined in EN ISO 9921. Results: Nine in ten lecturers were speaking with normal voice intensity (60-65 dB and only one full-time university lecturer was speaking with raised voice (66-71 dB. Conclusions: It was found that in the room of the same acoustic conditions the lecturers spoke with different intensities of voice. Some lecturers occasionally, and one all the time spoke with the voice intensity specified by PN-EN ISO 9921 as a raised voice. The results of the preliminary study warrant further studies in a larger group of teachers. Med Pr 2013;64(6:797–804

  8. ACADEMIC TRAINING LECTURE

    CERN Multimedia

    Academic Training; Tel 73127

    2001-01-01

    28, 29, 30, 31 May and 1 June REGULAR LECTURE PROGRAMME From 11:00 hrs - Main Auditorium bldg. 500 Quantum computing and Quantum cryptography T. Hey / University of Southampton, GB, and D. Ross / CERN-TH This course will give both an overview and a detailed introduction to quantum computing and quantum cryptography. The first lecture will survey the field, starting from its origins in Feyman's lecture in 1981. The next three lectures will explain in detail the relevance of Bell states and the workings of Grover's Quantum Search and Shor's quantum factorization algorithms. In addition, an explanation of quantum teleportation will be given. The last lecture will survey the recent progress towards realizing working quantum computers and quantum cryptographic systems.

  9. Pancreatic gross tumor volume contouring on computed tomography (CT) compared with magnetic resonance imaging (MRI): Results of an international contouring conference.

    Science.gov (United States)

    Hall, William A; Heerkens, Hanne D; Paulson, Eric S; Meijer, Gert J; Kotte, Alexis N; Knechtges, Paul; Parikh, Parag J; Bassetti, Michael F; Lee, Percy; Aitken, Katharine L; Palta, Manisha; Myrehaug, Sten; Koay, Eugene J; Portelance, Lorraine; Ben-Josef, Edgar; Erickson, Beth A

    Accurate identification of the gross tumor volume (GTV) in pancreatic adenocarcinoma is challenging. We sought to understand differences in GTV delineation using pancreatic computed tomography (CT) compared with magnetic resonance imaging (MRI). Twelve attending radiation oncologists were convened for an international contouring symposium. All participants had a clinical and research interest in pancreatic adenocarcinoma. CT and MRI scans from 3 pancreatic cases were used for contouring. CT and MRI GTVs were analyzed and compared. Interobserver variability was compared using Dice's similarity coefficient (DSC), Hausdorff distances, and Jaccard indices. Mann-Whitney tests were used to check for significant differences. Consensus contours on CT and MRI scans and constructed count maps were used to visualize the agreement. Agreement regarding the optimal method to determine GTV definition using MRI was reached. Six contour sets (3 from CT and 3 from MRI) were obtained and compared for each observer, totaling 72 contour sets. The mean volume of contours on CT was significantly larger at 57.48 mL compared with a mean of 45.76 mL on MRI, P = .011. The standard deviation obtained from the CT contours was significantly larger than the standard deviation from the MRI contours (P = .027). The mean DSC was 0.73 for the CT and 0.72 for the MRI (P = .889). The conformity index measurement was similar for CT and MRI (P = .58). Count maps were created to highlight differences in the contours from CT and MRI. Using MRI as a primary image set to define a pancreatic adenocarcinoma GTV resulted in smaller contours compared with CT. No differences in DSC or the conformity index were seen between MRI and CT. A stepwise method is recommended as an approach to contour a pancreatic GTV using MRI. Copyright © 2017 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

  10. Active contour based segmentation of resected livers in CT images

    Science.gov (United States)

    Oelmann, Simon; Oyarzun Laura, Cristina; Drechsler, Klaus; Wesarg, Stefan

    2015-03-01

    The majority of state of the art segmentation algorithms are able to give proper results in healthy organs but not in pathological ones. However, many clinical applications require an accurate segmentation of pathological organs. The determination of the target boundaries for radiotherapy or liver volumetry calculations are examples of this. Volumetry measurements are of special interest after tumor resection for follow up of liver regrow. The segmentation of resected livers presents additional challenges that were not addressed by state of the art algorithms. This paper presents a snakes based algorithm specially developed for the segmentation of resected livers. The algorithm is enhanced with a novel dynamic smoothing technique that allows the active contour to propagate with different speeds depending on the intensities visible in its neighborhood. The algorithm is evaluated in 6 clinical CT images as well as 18 artificial datasets generated from additional clinical CT images.

  11. A cognitive evaluation procedure for contour based shape descriptors

    NARCIS (Netherlands)

    Ghosh, Anarta; Petkov, Nicolai

    2005-01-01

    Present image processing algorithms are unable to extract a neat and closed contour of an object of interest from a natural image. Advanced contour detection algorithms extract the contour of an object of interest from a natural scene with a side effect of depletion of the contour. Hence in order to

  12. A Biologically Motivated Multiresolution Approach to Contour Detection

    Directory of Open Access Journals (Sweden)

    Alessandro Neri

    2007-01-01

    Full Text Available Standard edge detectors react to all local luminance changes, irrespective of whether they are due to the contours of the objects represented in a scene or due to natural textures like grass, foliage, water, and so forth. Moreover, edges due to texture are often stronger than edges due to object contours. This implies that further processing is needed to discriminate object contours from texture edges. In this paper, we propose a biologically motivated multiresolution contour detection method using Bayesian denoising and a surround inhibition technique. Specifically, the proposed approach deploys computation of the gradient at different resolutions, followed by Bayesian denoising of the edge image. Then, a biologically motivated surround inhibition step is applied in order to suppress edges that are due to texture. We propose an improvement of the surround suppression used in previous works. Finally, a contour-oriented binarization algorithm is used, relying on the observation that object contours lead to long connected components rather than to short rods obtained from textures. Experimental results show that our contour detection method outperforms standard edge detectors as well as other methods that deploy inhibition.

  13. B-Spline Active Contour with Handling of Topology Changes for Fast Video Segmentation

    Directory of Open Access Journals (Sweden)

    Frederic Precioso

    2002-06-01

    Full Text Available This paper deals with video segmentation for MPEG-4 and MPEG-7 applications. Region-based active contour is a powerful technique for segmentation. However most of these methods are implemented using level sets. Although level-set methods provide accurate segmentation, they suffer from large computational cost. We propose to use a regular B-spline parametric method to provide a fast and accurate segmentation. Our B-spline interpolation is based on a fixed number of points 2j depending on the level of the desired details. Through this spatial multiresolution approach, the computational cost of the segmentation is reduced. We introduce a length penalty. This results in improving both smoothness and accuracy. Then we show some experiments on real-video sequences.

  14. The equivalent internal orientation and position noise for contour integration.

    Science.gov (United States)

    Baldwin, Alex S; Fu, Minnie; Farivar, Reza; Hess, Robert F

    2017-10-12

    Contour integration is the joining-up of local responses to parts of a contour into a continuous percept. In typical studies observers detect contours formed of discrete wavelets, presented against a background of random wavelets. This measures performance for detecting contours in the limiting external noise that background provides. Our novel task measures contour integration without requiring any background noise. This allowed us to perform noise-masking experiments using orientation and position noise. From these we measure the equivalent internal noise for contour integration. We found an orientation noise of 6° and position noise of 3 arcmin. Orientation noise was 2.6x higher in contour integration compared to an orientation discrimination control task. Comparing against a position discrimination task found position noise in contours to be 2.4x lower. This suggests contour integration involves intermediate processing that enhances the quality of element position representation at the expense of element orientation. Efficiency relative to the ideal observer was lower for the contour tasks (36% in orientation noise, 21% in position noise) compared to the controls (54% and 57%).

  15. Image Interpolation with Contour Stencils

    OpenAIRE

    Pascal Getreuer

    2011-01-01

    Image interpolation is the problem of increasing the resolution of an image. Linear methods must compromise between artifacts like jagged edges, blurring, and overshoot (halo) artifacts. More recent works consider nonlinear methods to improve interpolation of edges and textures. In this paper we apply contour stencils for estimating the image contours based on total variation along curves and then use this estimation to construct a fast edge-adaptive interpolation.

  16. Interactive 3D segmentation using connected orthogonal contours

    NARCIS (Netherlands)

    de Bruin, P. W.; Dercksen, V. J.; Post, F. H.; Vossepoel, A. M.; Streekstra, G. J.; Vos, F. M.

    2005-01-01

    This paper describes a new method for interactive segmentation that is based on cross-sectional design and 3D modelling. The method represents a 3D model by a set of connected contours that are planar and orthogonal. Planar contours overlayed on image data are easily manipulated and linked contours

  17. Processing convexity and concavity along a 2-D contour: figure-ground, structural shape, and attention.

    Science.gov (United States)

    Bertamini, Marco; Wagemans, Johan

    2013-04-01

    Interest in convexity has a long history in vision science. For smooth contours in an image, it is possible to code regions of positive (convex) and negative (concave) curvature, and this provides useful information about solid shape. We review a large body of evidence on the role of this information in perception of shape and in attention. This includes evidence from behavioral, neurophysiological, imaging, and developmental studies. A review is necessary to analyze the evidence on how convexity affects (1) separation between figure and ground, (2) part structure, and (3) attention allocation. Despite some broad agreement on the importance of convexity in these areas, there is a lack of consensus on the interpretation of specific claims--for example, on the contribution of convexity to metric depth and on the automatic directing of attention to convexities or to concavities. The focus is on convexity and concavity along a 2-D contour, not convexity and concavity in 3-D, but the important link between the two is discussed. We conclude that there is good evidence for the role of convexity information in figure-ground organization and in parsing, but other, more specific claims are not (yet) well supported.

  18. Contour plotting programs for printer and Calcomp plotter

    International Nuclear Information System (INIS)

    Moller, P.

    1980-07-01

    Contour plotting programs for plotting contour diagrams on printers or Calcomp plotters are described. The subroutines also exist in versions that are useful for the special application of finding minima and saddlepoints of nuclear potential energy surfaces generated by the subroutine PETR3 of another program package. For the general user, however, the most interesting aspect of the plotting package is probably the possibility of generating printer contour plots. The plotting of printer contour plots is a very fast and convenient way of displaying two-dimensional functions. 3 figures

  19. Active contour-based visual tracking by integrating colors, shapes, and motions.

    Science.gov (United States)

    Hu, Weiming; Zhou, Xue; Li, Wei; Luo, Wenhan; Zhang, Xiaoqin; Maybank, Stephen

    2013-05-01

    In this paper, we present a framework for active contour-based visual tracking using level sets. The main components of our framework include contour-based tracking initialization, color-based contour evolution, adaptive shape-based contour evolution for non-periodic motions, dynamic shape-based contour evolution for periodic motions, and the handling of abrupt motions. For the initialization of contour-based tracking, we develop an optical flow-based algorithm for automatically initializing contours at the first frame. For the color-based contour evolution, Markov random field theory is used to measure correlations between values of neighboring pixels for posterior probability estimation. For adaptive shape-based contour evolution, the global shape information and the local color information are combined to hierarchically evolve the contour, and a flexible shape updating model is constructed. For the dynamic shape-based contour evolution, a shape mode transition matrix is learnt to characterize the temporal correlations of object shapes. For the handling of abrupt motions, particle swarm optimization is adopted to capture the global motion which is applied to the contour in the current frame to produce an initial contour in the next frame.

  20. Noninvasive Body Contouring: A Male Perspective.

    Science.gov (United States)

    Wat, Heidi; Wu, Douglas C; Goldman, Mitchel P

    2018-01-01

    Noninvasive body contouring is an attractive therapeutic modality to enhance the ideal male physique. Men place higher value on enhancing a well-defined, strong, masculine jawline and developing a V-shaped taper through the upper body. An understanding of the body contour men strive for allows the treating physician to focus on areas that are of most concern to men, thus enhancing patient experience and satisfaction. This article discusses noninvasive body contouring techniques, taking into account the unique aesthetic concerns of the male patient by combining an analysis of the existing literature with our own clinical experience. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Summing over Feynman histories by functional contour integration

    International Nuclear Information System (INIS)

    Garrison, J.C.; Wright, E.M.

    1986-01-01

    The authors show how complex paths can be consistently introduced into sums for Feynman histories by using the notion of functional contour integration. For a kappa-dimensional system specified by a potential with suitable analyticity properties, each coordinate axis is replaced by a copy of the complex plane, and at each instant of time a contour is chosen in each plane. This map from the time axis into the set of complex contours defines a functional contour. The family of contours labelled by time generates a (kappa+1)-dimensional submanifold of the (2kappa+1)-dimensional space defined by the cartesian product of the time axis and the coordinate planes. The complex Feynman paths lie on this submanifold. An application of this idea to systems described by absorptive potentials yields a simple derivation of the correct WKB result in terms of a complex path that extremalises the action. The method can also be applied to spherically symmetric potentials by using a partial wave expansion and restricting the contours appropriately. (author)

  2. Combining prior day contours to improve automated prostate segmentation

    International Nuclear Information System (INIS)

    Godley, Andrew; Sheplan Olsen, Lawrence J.; Stephans, Kevin; Zhao Anzi

    2013-01-01

    Purpose: To improve the accuracy of automatically segmented prostate, rectum, and bladder contours required for online adaptive therapy. The contouring accuracy on the current image guidance [image guided radiation therapy (IGRT)] scan is improved by combining contours from earlier IGRT scans via the simultaneous truth and performance level estimation (STAPLE) algorithm. Methods: Six IGRT prostate patients treated with daily kilo-voltage (kV) cone-beam CT (CBCT) had their original plan CT and nine CBCTs contoured by the same physician. Three types of automated contours were produced for analysis. (1) Plan: By deformably registering the plan CT to each CBCT and then using the resulting deformation field to morph the plan contours to match the CBCT anatomy. (2) Previous: The contour set drawn by the physician on the previous day CBCT is similarly deformed to match the current CBCT anatomy. (3) STAPLE: The contours drawn by the physician, on each prior CBCT and the plan CT, are deformed to match the CBCT anatomy to produce multiple contour sets. These sets are combined using the STAPLE algorithm into one optimal set. Results: Compared to plan and previous, STAPLE improved the average Dice's coefficient (DC) with the original physician drawn CBCT contours to a DC as follows: Bladder: 0.81 ± 0.13, 0.91 ± 0.06, and 0.92 ± 0.06; Prostate: 0.75 ± 0.08, 0.82 ± 0.05, and 0.84 ± 0.05; and Rectum: 0.79 ± 0.06, 0.81 ± 0.06, and 0.85 ± 0.04, respectively. The STAPLE results are within intraobserver consistency, determined by the physician blindly recontouring a subset of CBCTs. Comparing plans recalculated using the physician and STAPLE contours showed an average disagreement less than 1% for prostate D98 and mean dose, and 5% and 3% for bladder and rectum mean dose, respectively. One scan takes an average of 19 s to contour. Using five scans plus STAPLE takes less than 110 s on a 288 core graphics processor unit. Conclusions: Combining the plan and all prior days via

  3. Variation in contour and cancer of stomach

    International Nuclear Information System (INIS)

    Lee, Won Hong; Hwang, Seon Moon; Yoon, Kwon Ha

    1999-01-01

    There were four types of stomach contour included eutonic, hypotonic, steerhorn, and cascade. The aim of this study is to clarify relationship between incidence of stomach cancer and contour variation of the stomach. Double- contrast upper gastrointestinal study was performed in 1,546 patients, who had dyspepsia or other gastrointestinal tract symptoms. The radiographs were classified into the four types including eutonic, hypotonic, steerhorn, and cascade according to stomach contour in relation to body build. We also reviewed pathologic reports on endoscopic biopsy or surgical specimen. We studied the presence of relationship between incidence of stomach cancer and variation of stomach contour. We also examined the incidence of gastritis and gastric ulcer to the stomach contour variation. Of total 1,546 patients, eutonic stomach were 438(28.3%), hypotonic 911(58.9%), steerhorn 102(6.5%) and cascade 95(6.2%). Stomach cancer was found in 139(31.7%) of 438 eutonic stomachs, in 135(14.8%) of 911 hypotonic, in 42(41.2%) of 102 steerhorn, and in 24(36.9%) of 95 cascade (P=0.001). In hypotonic stomach, the incidence of stomach cancer was lower compared to the other three types significantly (p<0.05). Gastritis or gastric ulcer was found in 146(33.3%) of eutonic stomach, in 293(32.1%) of hypotonic, in 36(35.2%) of steerhorn, and in 26(27.3%) of cascade (p=0.640). In conclusion, gastric contour variation seems to be a factor affecting development of stomach cancer. The patients with hypotonic stomach may have lower incidence of stomach cancer than that of the other types. There was no relationship between the contour and gastric ulcer

  4. Variation in contour and cancer of stomach

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Hong; Hwang, Seon Moon [Asan Medical Center, Asan (Korea, Republic of); Yoon, Kwon Ha [College of Medicine, Wonkwang Univ., Iksan (Korea, Republic of)

    1999-04-01

    There were four types of stomach contour included eutonic, hypotonic, steerhorn, and cascade. The aim of this study is to clarify relationship between incidence of stomach cancer and contour variation of the stomach. Double- contrast upper gastrointestinal study was performed in 1,546 patients, who had dyspepsia or other gastrointestinal tract symptoms. The radiographs were classified into the four types including eutonic, hypotonic, steerhorn, and cascade according to stomach contour in relation to body build. We also reviewed pathologic reports on endoscopic biopsy or surgical specimen. We studied the presence of relationship between incidence of stomach cancer and variation of stomach contour. We also examined the incidence of gastritis and gastric ulcer to the stomach contour variation. Of total 1,546 patients, eutonic stomach were 438(28.3%), hypotonic 911(58.9%), steerhorn 102(6.5%) and cascade 95(6.2%). Stomach cancer was found in 139(31.7%) of 438 eutonic stomachs, in 135(14.8%) of 911 hypotonic, in 42(41.2%) of 102 steerhorn, and in 24(36.9%) of 95 cascade (P=0.001). In hypotonic stomach, the incidence of stomach cancer was lower compared to the other three types significantly (p<0.05). Gastritis or gastric ulcer was found in 146(33.3%) of eutonic stomach, in 293(32.1%) of hypotonic, in 36(35.2%) of steerhorn, and in 26(27.3%) of cascade (p=0.640). In conclusion, gastric contour variation seems to be a factor affecting development of stomach cancer. The patients with hypotonic stomach may have lower incidence of stomach cancer than that of the other types. There was no relationship between the contour and gastric ulcer.

  5. Interactive lectures in engineering education

    NARCIS (Netherlands)

    van Dijk, L.A.; van den Berg, G.C.; van Keulen, H.

    2001-01-01

    This article discusses an alternative approach to lecturing: the interactive lecture. In the literature, interactive teaching is forwarded as a means to increase the effectiveness of lectures. Members of lecturing staff still seem, however, reluctant to incorporate interactive teaching in their

  6. Automatic bone outer contour extraction from B-modes ultrasound images based on local phase symmetry and quadratic polynomial fitting

    Science.gov (United States)

    Karlita, Tita; Yuniarno, Eko Mulyanto; Purnama, I. Ketut Eddy; Purnomo, Mauridhi Hery

    2017-06-01

    Analyzing ultrasound (US) images to get the shapes and structures of particular anatomical regions is an interesting field of study since US imaging is a non-invasive method to capture internal structures of a human body. However, bone segmentation of US images is still challenging because it is strongly influenced by speckle noises and it has poor image quality. This paper proposes a combination of local phase symmetry and quadratic polynomial fitting methods to extract bone outer contour (BOC) from two dimensional (2D) B-modes US image as initial steps of three-dimensional (3D) bone surface reconstruction. By using local phase symmetry, the bone is initially extracted from US images. BOC is then extracted by scanning one pixel on the bone boundary in each column of the US images using first phase features searching method. Quadratic polynomial fitting is utilized to refine and estimate the pixel location that fails to be detected during the extraction process. Hole filling method is then applied by utilize the polynomial coefficients to fill the gaps with new pixel. The proposed method is able to estimate the new pixel position and ensures smoothness and continuity of the contour path. Evaluations are done using cow and goat bones by comparing the resulted BOCs with the contours produced by manual segmentation and contours produced by canny edge detection. The evaluation shows that our proposed methods produces an excellent result with average MSE before and after hole filling at the value of 0.65.

  7. Ingenious Snake: An Adaptive Multi-Class Contours Extraction

    Science.gov (United States)

    Li, Baolin; Zhou, Shoujun

    2018-04-01

    Active contour model (ACM) plays an important role in computer vision and medical image application. The traditional ACMs were used to extract single-class of object contours. While, simultaneous extraction of multi-class of interesting contours (i.e., various contours with closed- or open-ended) have not been solved so far. Therefore, a novel ACM model named “Ingenious Snake” is proposed to adaptively extract these interesting contours. In the first place, the ridge-points are extracted based on the local phase measurement of gradient vector flow field; the consequential ridgelines initialization are automated with high speed. Secondly, the contours’ deformation and evolvement are implemented with the ingenious snake. In the experiments, the result from initialization, deformation and evolvement are compared with the existing methods. The quantitative evaluation of the structure extraction is satisfying with respect of effectiveness and accuracy.

  8. Issues in Lecturing in a Second Language: Lecturer's Behaviour and Students' Perceptions

    Science.gov (United States)

    Miller, Lindsay

    2007-01-01

    This article explores how Hong Kong Chinese engineering students with low English language proficiency manage to cope with their lectures given in English. An ethnographic case study approach was used with multiple sources of data triangulated to provide a picture of the lecture event from both the students' and the lecturer's perspectives. One of…

  9. Low level constraints on dynamic contour path integration.

    Directory of Open Access Journals (Sweden)

    Sophie Hall

    Full Text Available Contour integration is a fundamental visual process. The constraints on integrating discrete contour elements and the associated neural mechanisms have typically been investigated using static contour paths. However, in our dynamic natural environment objects and scenes vary over space and time. With the aim of investigating the parameters affecting spatiotemporal contour path integration, we measured human contrast detection performance of a briefly presented foveal target embedded in dynamic collinear stimulus sequences (comprising five short 'predictor' bars appearing consecutively towards the fovea, followed by the 'target' bar in four experiments. The data showed that participants' target detection performance was relatively unchanged when individual contour elements were separated by up to 2° spatial gap or 200 ms temporal gap. Randomising the luminance contrast or colour of the predictors, on the other hand, had similar detrimental effect on grouping dynamic contour path and subsequent target detection performance. Randomising the orientation of the predictors reduced target detection performance greater than introducing misalignment relative to the contour path. The results suggest that the visual system integrates dynamic path elements to bias target detection even when the continuity of path is disrupted in terms of spatial (2°, temporal (200 ms, colour (over 10 colours and luminance (-25% to 25% information. We discuss how the findings can be largely reconciled within the functioning of V1 horizontal connections.

  10. Spatial profile of contours inducing long-range color assimilation.

    Science.gov (United States)

    Devinck, Frédéric; Spillmann, Lothar; Werner, John S

    2006-01-01

    Color induction was measured using a matching method for two spatial patterns, each composed of double contours. In one pattern (the standard), the contours had sharp edges to induce the Watercolor Effect (WCE); in the other, the two contours had a spatial taper so that the overall profile produced a sawtooth edge, or ramped stimulus. These patterns were chosen based on our previous study demonstrating that the strength of the chromatic WCE depends on a luminance difference between the two contours. Low-pass chromatic mechanisms, unlike bandpass luminance mechanisms, may be expected to be insensitive to the difference between the two spatial profiles. The strength of the watercolor spreading was similar for the two patterns at narrow widths of the contour possibly because of chromatic aberration, but with wider contours, the standard stimulus produced stronger assimilation than the ramped stimulus. This research suggests that luminance-dependent chromatic mechanisms mediate the WCE and that these mechanisms are sensitive to differences in the two spatial profiles of the pattern contours only when they are wide.

  11. Academic Training Lecture - Regular lecture programme

    CERN Multimedia

    PH Department

    2011-01-01

    Wednesday 28, Thursday 29 and Friday 30 September 2011 Supersymmetric Recipes by Prof. Ben Allanech / University of Cambridge, UK  from 11:00 to 12:00 (Europe/Zurich) at CERN ( Main Auditorium, Bldg. 500 ) In these lectures, I shall describe the theory of supersymmetry accessible to people with a knowledge of basic quantum field theory. The lectures will contain recipes of how to calculate which interactions (and which special relations) are in supersymmetry, without providing detailed proofs of where they come from. We shall also cover: motivation for weak-scale supersymmetry and the minimal supersymmetric standard model.

  12. Roentgenological differential diagnosis of the psoas contour

    International Nuclear Information System (INIS)

    Voran, G.; Pfab, R.; Hess, F.

    1984-01-01

    The assessment of the psoas border contour in the X-ray photo of the abdomen is important for differential diagnostic considerations. For the separation of fallacious psoas configurations which are similar to the well defined pathological form changes, a regular supine position of the patient was chosen, and the psoas examined without and with muscle tension. The whole visible psoas muscle system did not show any unilateral bulging of the border silhouette during muscle action. Isolated tension of the left psoas muscle induced a distinct deviation of both border contours to the left side, too. There was a clear tendency of a more distinct psoas border contour and of augmented opacity of the muscle over its whole length under muscle tension. Changes similar to the bulging border contour of a psoas abscess were not produced by muscular action. (orig.) [de

  13. [Development of a Software for Automatically Generated Contours in Eclipse TPS].

    Science.gov (United States)

    Xie, Zhao; Hu, Jinyou; Zou, Lian; Zhang, Weisha; Zou, Yuxin; Luo, Kelin; Liu, Xiangxiang; Yu, Luxin

    2015-03-01

    The automatic generation of planning targets and auxiliary contours have achieved in Eclipse TPS 11.0. The scripting language autohotkey was used to develop a software for automatically generated contours in Eclipse TPS. This software is named Contour Auto Margin (CAM), which is composed of operational functions of contours, script generated visualization and script file operations. RESULTS Ten cases in different cancers have separately selected, in Eclipse TPS 11.0 scripts generated by the software could not only automatically generate contours but also do contour post-processing. For different cancers, there was no difference between automatically generated contours and manually created contours. The CAM is a user-friendly and powerful software, and can automatically generated contours fast in Eclipse TPS 11.0. With the help of CAM, it greatly save plan preparation time and improve working efficiency of radiation therapy physicists.

  14. Incomplete contour representations and shape descriptors : ICR test studies

    NARCIS (Netherlands)

    Ghosh, Anarta; Petkov, Nicolai; Gregorio, MD; DiMaio,; Frucci, M; Musio, C

    2005-01-01

    Inspired by psychophysical studies of the human cognitive abilities we propose a novel aspect and a method for performance evaluation of contour based shape recognition algorithms regarding their robustness to incompleteness of contours. We use complete contour representations of objects as a

  15. Academic Training Lecture - Regular Programme

    CERN Multimedia

    PH Department

    2011-01-01

    Regular Lecture Programme 9 May 2011 ACT Lectures on Detectors - Inner Tracking Detectors by Pippa Wells (CERN) 10 May 2011 ACT Lectures on Detectors - Calorimeters (2/5) by Philippe Bloch (CERN) 11 May 2011 ACT Lectures on Detectors - Muon systems (3/5) by Kerstin Hoepfner (RWTH Aachen) 12 May 2011 ACT Lectures on Detectors - Particle Identification and Forward Detectors by Peter Krizan (University of Ljubljana and J. Stefan Institute, Ljubljana, Slovenia) 13 May 2011 ACT Lectures on Detectors - Trigger and Data Acquisition (5/5) by Dr. Brian Petersen (CERN) from 11:00 to 12:00 at CERN ( Bldg. 222-R-001 - Filtration Plant )

  16. 3D Filament Network Segmentation with Multiple Active Contours

    Science.gov (United States)

    Xu, Ting; Vavylonis, Dimitrios; Huang, Xiaolei

    2014-03-01

    Fluorescence microscopy is frequently used to study two and three dimensional network structures formed by cytoskeletal polymer fibers such as actin filaments and microtubules. While these cytoskeletal structures are often dilute enough to allow imaging of individual filaments or bundles of them, quantitative analysis of these images is challenging. To facilitate quantitative, reproducible and objective analysis of the image data, we developed a semi-automated method to extract actin networks and retrieve their topology in 3D. Our method uses multiple Stretching Open Active Contours (SOACs) that are automatically initialized at image intensity ridges and then evolve along the centerlines of filaments in the network. SOACs can merge, stop at junctions, and reconfigure with others to allow smooth crossing at junctions of filaments. The proposed approach is generally applicable to images of curvilinear networks with low SNR. We demonstrate its potential by extracting the centerlines of synthetic meshwork images, actin networks in 2D TIRF Microscopy images, and 3D actin cable meshworks of live fission yeast cells imaged by spinning disk confocal microscopy.

  17. SU-C-BRB-05: Determining the Adequacy of Auto-Contouring Via Probabilistic Assessment of Ensuing Treatment Plan Metrics in Comparison with Manual Contours

    International Nuclear Information System (INIS)

    Nourzadeh, H; Watkins, W; Siebers, J; Ahmad, M

    2016-01-01

    Purpose: To determine if auto-contour and manual-contour—based plans differ when evaluated with respect to probabilistic coverage metrics and biological model endpoints for prostate IMRT. Methods: Manual and auto-contours were created for 149 CT image sets acquired from 16 unique prostate patients. A single physician manually contoured all images. Auto-contouring was completed utilizing Pinnacle’s Smart Probabilistic Image Contouring Engine (SPICE). For each CT, three different 78 Gy/39 fraction 7-beam IMRT plans are created; PD with drawn ROIs, PAS with auto-contoured ROIs, and PM with auto-contoured OARs with the manually drawn target. For each plan, 1000 virtual treatment simulations with different sampled systematic errors for each simulation and a different sampled random error for each fraction were performed using our in-house GPU-accelerated robustness analyzer tool which reports the statistical probability of achieving dose-volume metrics, NTCP, TCP, and the probability of achieving the optimization criteria for both auto-contoured (AS) and manually drawn (D) ROIs. Metrics are reported for all possible cross-evaluation pairs of ROI types (AS,D) and planning scenarios (PD,PAS,PM). Bhattacharyya coefficient (BC) is calculated to measure the PDF similarities for the dose-volume metric, NTCP, TCP, and objectives with respect to the manually drawn contour evaluated on base plan (D-PD). Results: We observe high BC values (BC≥0.94) for all OAR objectives. BC values of max dose objective on CTV also signify high resemblance (BC≥0.93) between the distributions. On the other hand, BC values for CTV’s D95 and Dmin objectives are small for AS-PM, AS-PD. NTCP distributions are similar across all evaluation pairs, while TCP distributions of AS-PM, AS-PD sustain variations up to %6 compared to other evaluated pairs. Conclusion: No significant probabilistic differences are observed in the metrics when auto-contoured OARs are used. The prostate auto-contour needs

  18. SU-C-BRB-05: Determining the Adequacy of Auto-Contouring Via Probabilistic Assessment of Ensuing Treatment Plan Metrics in Comparison with Manual Contours

    Energy Technology Data Exchange (ETDEWEB)

    Nourzadeh, H; Watkins, W; Siebers, J; Ahmad, M [University of Virginia Health Systems, Charlottesville, VA (United States)

    2016-06-15

    Purpose: To determine if auto-contour and manual-contour—based plans differ when evaluated with respect to probabilistic coverage metrics and biological model endpoints for prostate IMRT. Methods: Manual and auto-contours were created for 149 CT image sets acquired from 16 unique prostate patients. A single physician manually contoured all images. Auto-contouring was completed utilizing Pinnacle’s Smart Probabilistic Image Contouring Engine (SPICE). For each CT, three different 78 Gy/39 fraction 7-beam IMRT plans are created; PD with drawn ROIs, PAS with auto-contoured ROIs, and PM with auto-contoured OARs with the manually drawn target. For each plan, 1000 virtual treatment simulations with different sampled systematic errors for each simulation and a different sampled random error for each fraction were performed using our in-house GPU-accelerated robustness analyzer tool which reports the statistical probability of achieving dose-volume metrics, NTCP, TCP, and the probability of achieving the optimization criteria for both auto-contoured (AS) and manually drawn (D) ROIs. Metrics are reported for all possible cross-evaluation pairs of ROI types (AS,D) and planning scenarios (PD,PAS,PM). Bhattacharyya coefficient (BC) is calculated to measure the PDF similarities for the dose-volume metric, NTCP, TCP, and objectives with respect to the manually drawn contour evaluated on base plan (D-PD). Results: We observe high BC values (BC≥0.94) for all OAR objectives. BC values of max dose objective on CTV also signify high resemblance (BC≥0.93) between the distributions. On the other hand, BC values for CTV’s D95 and Dmin objectives are small for AS-PM, AS-PD. NTCP distributions are similar across all evaluation pairs, while TCP distributions of AS-PM, AS-PD sustain variations up to %6 compared to other evaluated pairs. Conclusion: No significant probabilistic differences are observed in the metrics when auto-contoured OARs are used. The prostate auto-contour needs

  19. Invariance Signatures: Characterizing contours by their departures from invariance

    OpenAIRE

    Squire, David; Caelli, Terry M.

    1997-01-01

    In this paper, a new invariant feature of two-dimensional contours is reported: the Invariance Signature. The Invariance Signature is a measure of the degree to which a contour is invariant under a variety of transformations, derived from the theory of Lie transformation groups. It is shown that the Invariance Signature is itself invariant under shift, rotation and scaling of the contour. Since it is derived from local properties of the contour, it is well-suited to a neural network implement...

  20. Cheap contouring of costly functions: the Pilot Approximation Trajectory algorithm

    International Nuclear Information System (INIS)

    Huttunen, Janne M J; Stark, Philip B

    2012-01-01

    The Pilot Approximation Trajectory (PAT) contour algorithm can find the contour of a function accurately when it is not practical to evaluate the function on a grid dense enough to use a standard contour algorithm, for instance, when evaluating the function involves conducting a physical experiment or a computationally intensive simulation. PAT relies on an inexpensive pilot approximation to the function, such as interpolating from a sparse grid of inexact values, or solving a partial differential equation (PDE) numerically using a coarse discretization. For each level of interest, the location and ‘trajectory’ of an approximate contour of this pilot function are used to decide where to evaluate the original function to find points on its contour. Those points are joined by line segments to form the PAT approximation of the contour of the original function. Approximating a contour numerically amounts to estimating a lower level set of the function, the set of points on which the function does not exceed the contour level. The area of the symmetric difference between the true lower level set and the estimated lower level set measures the accuracy of the contour. PAT measures its own accuracy by finding an upper confidence bound for this area. In examples, PAT can estimate a contour more accurately than standard algorithms, using far fewer function evaluations than standard algorithms require. We illustrate PAT by constructing a confidence set for viscosity and thermal conductivity of a flowing gas from simulated noisy temperature measurements, a problem in which each evaluation of the function to be contoured requires solving a different set of coupled nonlinear PDEs. (paper)

  1. VT 10 ft Contour Lines generated from bare earth lidar - Chittenden

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) ElevationContours_CN10T (10ft contours) was extracted from ElevationContours_CN2T (2ft contours), which was generated by USGS from the 2004...

  2. Spiral Light Beams and Contour Image Processing

    Science.gov (United States)

    Kishkin, Sergey A.; Kotova, Svetlana P.; Volostnikov, Vladimir G.

    Spiral beams of light are characterized by their ability to remain structurally unchanged at propagation. They may have the shape of any closed curve. In the present paper a new approach is proposed within the framework of the contour analysis based on a close cooperation of modern coherent optics, theory of functions and numerical methods. An algorithm for comparing contours is presented and theoretically justified, which allows convincing of whether two contours are similar or not to within the scale factor and/or rotation. The advantages and disadvantages of the proposed approach are considered; the results of numerical modeling are presented.

  3. Laughter in University Lectures

    Science.gov (United States)

    Nesi, Hilary

    2012-01-01

    This paper analyses laughter in spoken academic discourse, with the aim of discovering why lecturers provoke laughter in their lectures. A further purpose of the paper is to identify episodes in British data which may differ from those in other cultural contexts where other lecturing practices prevail, and thus to inform the design of study skills…

  4. Explicit calculation of multi-fold contour integrals of certain ratios of Euler gamma functions. Pt. 1

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Ivan [Valparaiso Univ. (Chile). Inst. de Fisica y Astronomia; Kniehl, Bernd A. [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik; Kondrashuk, Igor [Univ. del Bio-Bio, Chillan (Chile). Dept. de Ciencias Basicas; Notte-Cuello, Eduardo A. [La Serena Univ. (Chile). Dept. de Matematicas; Parra-Ferrada, Ivan [Talca Univ. (Chile). Inst. de Matematica y Fisica; Rojas-Medar, Marko A. [Univ. de Tarapaca, Arica (Chile). Inst. de Alta Investigacion

    2016-12-15

    In this paper we proceed to study properties of Mellin-Barnes (MB) transforms of Usyukina-Davydychev (UD) functions. In our previous papers [Nuclear Physics B 870 (2013) 243], [Nuclear Physics B 876 (2013) 322] we showed that multi-fold Mellin-Barnes (MB) transforms of Usyukina-Davydychev (UD) functions may be reduced to two-fold MB transforms and that the higher-order UD functions were obtained in terms of a differential operator by applying it to a slightly modified first UD function. The result is valid in d=4 dimensions and its analog in d=4-2ε dimensions exits too [Theoretical and Mathematical Physics 177 (2013) 1515]. In [Nuclear Physics B 870 (2013) 243] the chain of recurrent relations for analytically regularized UD functions was obtained implicitly by comparing the left hand side and the right hand side of the diagrammatic relations between the diagrams with different loop orders. In turn, these diagrammatic relations were obtained due to the method of loop reductions for the triangle ladder diagrams proposed in 1983 by Belokurov and Usyukina. Here we reproduce these recurrent relations by calculating explicitly via Barnes lemmas the contour integrals produced by the left hand sides of the diagrammatic relations. In such a way we explicitly calculate a family of multi-fold contour integrals of certain ratios of Euler gamma functions. We make a conjecture that similar results for the contour integrals are valid for a wider family of smooth functions which includes the MB transforms of UD functions.

  5. Contour adaptation reduces the spreading of edge induced colors.

    Science.gov (United States)

    Coia, Andrew J; Crognale, Michael A

    2017-04-25

    Brief exposure to flickering achromatic outlines of an area causes a reduction in the brightness contrast of the surface inside the area. This contour adaptation to achromatic contours does not reduce surface contrast when the surface is chromatic (the saturation or colorimetric purity of the surface is maintained). In addition to reducing the brightness of physical luminance contrast, contour adaptation also reduces (or even reverses) the illusory brightness contrast seen in the Craik-O'Brien-Cornsweet illusion, in which two physically identical grey areas appear different brightness because of a sharp luminance edge separating them. Chromatic color spreading illusions also occur with chromatic inducing edges, and an unanswered question is whether contour adaptation can reduce the perceived contrast of illusory color spreading from edges, even though it cannot reduce the perceived contrast of physical surface color. The current studies use a color spreading illusion known as the watercolor effect in order to test whether illusory color spreading is affected by contour adaptation. The general findings of physical achromatic contrast being reduced and chromatic contrast being robust to contour adaptation were replicated. However, both illusory brightness and color were reduced by contour adaptation, even when the illusion edges only differed in chromatic contrast with each other and the background. Additional studies adapting to chromatic contours showed opposite effects on illusory color contrast than achromatic adaptation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Forum: The Lecture and Student Learning. The Lecture's Absent Audience

    Science.gov (United States)

    Sciullo, Nick J.

    2017-01-01

    According to the "Oxford English Dictionary" ("OED"), the noun "lecture" dates from the 14th century and means the "action of reading, perusal. Also, that which is read or perused." This definition, while accurate and resonates today in many college classrooms, ignores a key feature of any lecture. The…

  7. The role of shape complexity in the detection of closed contours.

    Science.gov (United States)

    Wilder, John; Feldman, Jacob; Singh, Manish

    2016-09-01

    The detection of contours in noise has been extensively studied, but the detection of closed contours, such as the boundaries of whole objects, has received relatively little attention. Closed contours pose substantial challenges not present in the simple (open) case, because they form the outlines of whole shapes and thus take on a range of potentially important configural properties. In this paper we consider the detection of closed contours in noise as a probabilistic decision problem. Previous work on open contours suggests that contour complexity, quantified as the negative log probability (Description Length, DL) of the contour under a suitably chosen statistical model, impairs contour detectability; more complex (statistically surprising) contours are harder to detect. In this study we extended this result to closed contours, developing a suitable probabilistic model of whole shapes that gives rise to several distinct though interrelated measures of shape complexity. We asked subjects to detect either natural shapes (Exp. 1) or experimentally manipulated shapes (Exp. 2) embedded in noise fields. We found systematic effects of global shape complexity on detection performance, demonstrating how aspects of global shape and form influence the basic process of object detection. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. A Geminoid as Lecturer

    DEFF Research Database (Denmark)

    Abildgaard, Julie Rafn; Schärfe, Henrik

    2012-01-01

    In this paper we report our findings from an experiment with the teleoperated android Geminoid-DK. The geminoid took up the role of a university lecturer and delivered a 45 minute lecture in front of 150 freshmen students at Aalborg University. While considering the role of the geminoid in this e......In this paper we report our findings from an experiment with the teleoperated android Geminoid-DK. The geminoid took up the role of a university lecturer and delivered a 45 minute lecture in front of 150 freshmen students at Aalborg University. While considering the role of the geminoid...

  9. Contour Propagation Using Feature-Based Deformable Registration for Lung Cancer

    Directory of Open Access Journals (Sweden)

    Yuhan Yang

    2013-01-01

    Full Text Available Accurate target delineation of CT image is a critical step in radiotherapy treatment planning. This paper describes a novel strategy for automatic contour propagation, based on deformable registration, for CT images of lung cancer. The proposed strategy starts with a manual-delineated contour in one slice of a 3D CT image. By means of feature-based deformable registration, the initial contour in other slices of the image can be propagated automatically, and then refined by active contour approach. Three algorithms are employed in the strategy: the Speeded-Up Robust Features (SURF, Thin-Plate Spline (TPS, and an adapted active contour (Snake, used to refine and modify the initial contours. Five pulmonary cancer cases with about 400 slices and 1000 contours have been used to verify the proposed strategy. Experiments demonstrate that the proposed strategy can improve the segmentation performance in the pulmonary CT images. Jaccard similarity (JS mean is about 0.88 and the maximum of Hausdorff distance (HD is about 90%. In addition, delineation time has been considerably reduced. The proposed feature-based deformable registration method in the automatic contour propagation improves the delineation efficiency significantly.

  10. Data integrity systems for organ contours in radiation therapy planning.

    Science.gov (United States)

    Shah, Veeraj P; Lakshminarayanan, Pranav; Moore, Joseph; Tran, Phuoc T; Quon, Harry; Deville, Curtiland; McNutt, Todd R

    2018-06-12

    The purpose of this research is to develop effective data integrity models for contoured anatomy in a radiotherapy workflow for both real-time and retrospective analysis. Within this study, two classes of contour integrity models were developed: data driven models and contiguousness models. The data driven models aim to highlight contours which deviate from a gross set of contours from similar disease sites and encompass the following regions of interest (ROI): bladder, femoral heads, spinal cord, and rectum. The contiguousness models, which individually analyze the geometry of contours to detect possible errors, are applied across many different ROI's and are divided into two metrics: Extent and Region Growing over volume. After analysis, we found that 70% of detected bladder contours were verified as suspicious. The spinal cord and rectum models verified that 73% and 80% of contours were suspicious respectively. The contiguousness models were the most accurate models and the Region Growing model was the most accurate submodel. 100% of the detected noncontiguous contours were verified as suspicious, but in the cases of spinal cord, femoral heads, bladder, and rectum, the Region Growing model detected additional two to five suspicious contours that the Extent model failed to detect. When conducting a blind review to detect false negatives, it was found that all the data driven models failed to detect all suspicious contours. The Region Growing contiguousness model produced zero false negatives in all regions of interest other than prostate. With regards to runtime, the contiguousness via extent model took an average of 0.2 s per contour. On the other hand, the region growing method had a longer runtime which was dependent on the number of voxels in the contour. Both contiguousness models have potential for real-time use in clinical radiotherapy while the data driven models are better suited for retrospective use. © 2018 The Authors. Journal of Applied Clinical

  11. Perceptual representation and effectiveness of local figure-ground cues in natural contours.

    Science.gov (United States)

    Sakai, Ko; Matsuoka, Shouhei; Kurematsu, Ken; Hatori, Yasuhiro

    2015-01-01

    A contour shape strongly influences the perceptual segregation of a figure from the ground. We investigated the contribution of local contour shape to figure-ground segregation. Although previous studies have reported local contour features that evoke figure-ground perception, they were often image features and not necessarily perceptual features. First, we examined whether contour features, specifically, convexity, closure, and symmetry, underlie the perceptual representation of natural contour shapes. We performed similarity tests between local contours, and examined the contribution of the contour features to the perceptual similarities between the contours. The local contours were sampled from natural contours so that their distribution was uniform in the space composed of the three contour features. This sampling ensured the equal appearance frequency of the factors and a wide variety of contour shapes including those comprised of contradictory factors that induce figure in the opposite directions. This sampling from natural contours is advantageous in order to randomly pickup a variety of contours that satisfy a wide range of cue combinations. Multidimensional scaling analyses showed that the combinations of convexity, closure, and symmetry contribute to perceptual similarity, thus they are perceptual quantities. Second, we examined whether the three features contribute to local figure-ground perception. We performed psychophysical experiments to judge the direction of the figure along the local contours, and examined the contribution of the features to the figure-ground judgment. Multiple linear regression analyses showed that closure was a significant factor, but that convexity and symmetry were not. These results indicate that closure is dominant in the local figure-ground perception with natural contours when the other cues coexist with equal probability including contradictory cases.

  12. Perceptual representation and effectiveness of local figure–ground cues in natural contours

    Science.gov (United States)

    Sakai, Ko; Matsuoka, Shouhei; Kurematsu, Ken; Hatori, Yasuhiro

    2015-01-01

    A contour shape strongly influences the perceptual segregation of a figure from the ground. We investigated the contribution of local contour shape to figure–ground segregation. Although previous studies have reported local contour features that evoke figure–ground perception, they were often image features and not necessarily perceptual features. First, we examined whether contour features, specifically, convexity, closure, and symmetry, underlie the perceptual representation of natural contour shapes. We performed similarity tests between local contours, and examined the contribution of the contour features to the perceptual similarities between the contours. The local contours were sampled from natural contours so that their distribution was uniform in the space composed of the three contour features. This sampling ensured the equal appearance frequency of the factors and a wide variety of contour shapes including those comprised of contradictory factors that induce figure in the opposite directions. This sampling from natural contours is advantageous in order to randomly pickup a variety of contours that satisfy a wide range of cue combinations. Multidimensional scaling analyses showed that the combinations of convexity, closure, and symmetry contribute to perceptual similarity, thus they are perceptual quantities. Second, we examined whether the three features contribute to local figure–ground perception. We performed psychophysical experiments to judge the direction of the figure along the local contours, and examined the contribution of the features to the figure–ground judgment. Multiple linear regression analyses showed that closure was a significant factor, but that convexity and symmetry were not. These results indicate that closure is dominant in the local figure–ground perception with natural contours when the other cues coexist with equal probability including contradictory cases. PMID:26579057

  13. Perceptual Representation and Effectiveness of Local Figure-Ground Cues in Natural Contours

    Directory of Open Access Journals (Sweden)

    Ko eSakai

    2015-11-01

    Full Text Available A contour shape strongly influences the perceptual segregation of a figure from the ground. We investigated the contribution of local contour shape to figure-ground segregation. Although previous studies have reported local contour features that evoke figure-ground perception, they were often image features and not necessarily perceptual features. First, we examined whether contour features, specifically, convexity, closure, and symmetry, underlie the perceptual representation of natural contour shapes. We performed similarity tests between local contours, and examined the contribution of the contour features to the perceptual similarities between the contours. The local contours were sampled from natural contours so that their distribution was uniform in the space composed of the three contour features. This sampling ensured the equal appearance frequency of the factors and a wide variety of contour shapes including those comprised of contradictory factors that induce figure in the opposite directions. This sampling from natural contours is advantageous in order to randomly pickup a variety of contours that satisfy a wide range of cue combinations. Multidimensional scaling analyses showed that the combinations of convexity, closure, and symmetry contribute to perceptual similarity, thus they are perceptual quantities. Second, we examined whether the three features contribute to local figure-ground perception. We performed psychophysical experiments to judge the direction of the figure along the local contours, and examined the contribution of the features to the figure-ground judgment. Multiple linear regression analyses showed that closure was a significant factor, but that convexity and symmetry were not. These results indicate that closure is dominant in the local figure-ground perception with natural contours when the other cues coexist with equal probability including contradictory cases.

  14. Hand-Geometry Recognition Based on Contour Parameters

    NARCIS (Netherlands)

    Veldhuis, Raymond N.J.; Bazen, A.M.; Booij, W.D.T.; Hendrikse, A.J.; Jain, A.K.; Ratha, N.K.

    This paper demonstrates the feasibility of a new method of hand-geometry recognition based on parameters derived from the contour of the hand. The contour is completely determined by the black-and-white image of the hand and can be derived from it by means of simple image-processing techniques. It

  15. Prostate Contouring Variation: Can It Be Fixed?

    International Nuclear Information System (INIS)

    Khoo, Eric L.H.; Schick, Karlissa; Plank, Ashley W.; Poulsen, Michael; Wong, Winnie W.G.; Middleton, Mark; Martin, Jarad M.

    2012-01-01

    Purpose: To assess whether an education program on CT and MRI prostate anatomy would reduce inter- and intraobserver prostate contouring variation among experienced radiation oncologists. Methods and Materials: Three patient CT and MRI datasets were selected. Five radiation oncologists contoured the prostate for each patient on CT first, then MRI, and again between 2 and 4 weeks later. Three education sessions were then conducted. The same contouring process was then repeated with the same datasets and oncologists. The observer variation was assessed according to changes in the ratio of the encompassing volume to intersecting volume (volume ratio [VR]), across sets of target volumes. Results: For interobserver variation, there was a 15% reduction in mean VR with CT, from 2.74 to 2.33, and a 40% reduction in mean VR with MRI, from 2.38 to 1.41 after education. A similar trend was found for intraobserver variation, with a mean VR reduction for CT and MRI of 9% (from 1.51 to 1.38) and 16% (from 1.37 to 1.15), respectively. Conclusion: A well-structured education program has reduced both inter- and intraobserver prostate contouring variations. The impact was greater on MRI than on CT. With the ongoing incorporation of new technologies into routine practice, education programs for target contouring should be incorporated as part of the continuing medical education of radiation oncologists.

  16. A cardiac contouring atlas for radiotherapy

    DEFF Research Database (Denmark)

    Duane, Frances; Aznar, Marianne C; Bartlett, Freddie

    2017-01-01

    defined from cardiology models and agreed by two cardiologists. Reference atlas contours were delineated and written guidelines prepared. Six radiation oncologists tested the atlas. Spatial variation was assessed using the DICE similarity coefficient (DSC) and the directed Hausdorff average distance (d→H,avg......-observer contour separation (mean d→H,avg) was 1.5-2.2mm for left ventricular segments and 1.3-5.1mm for coronary artery segments. This spatial variation resulted in

  17. Public Lectures | Events | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Public and special lectures. Academy Public Lectures · Public and special lectures in Mid-Year and Annual Meetings · Platinum Jubilee Lectures. Academy's annual and mid-year meetings include a special lecture by a senior Fellow in the morning of each meeting day and one public lecture by an eminent person, from ...

  18. ACADEMIC TRAINING LECTURE

    CERN Multimedia

    Academic Training; Tel. 73127

    2001-01-01

    12, 13, 14, 15 & 16 March REGULAR LECTURE PROGRAMME From 11:00 hrs - Main Auditorium bldg. 500 Telecommunication for the future Rob Parker / CERN-IT Few fields have experienced such a high level of technical advance over the last few decades as that of telecommunications. This lecture series will track the evolution of telecommunications systems since their inception, and consider how technology is likely to advance over the next years. A personal view will also be given of the effect of these innovations on our work and leisure activities.The lecture series will be aimed at an audience with no specific technical knowledge of telecommunications.

  19. Lectures on string theory

    International Nuclear Information System (INIS)

    Thorn, C.B.

    1988-01-01

    Several topics are discussed in string theory presented as three lectures to the Spring School on Superstrings at the ICTP at Trieste, Italy, in April, 1988. The first lecture is devoted to some general aspects of conformal invariance and duality. The second sketches methods for carrying out perturbative calculations in string field theory. The final lecture presents an alternative lattice approach to a nonperturbative formulation of the sum over world surfaces. 35 refs., 12 figs

  20. A Voronoi interior adjacency-based approach for generating a contour tree

    Science.gov (United States)

    Chen, Jun; Qiao, Chaofei; Zhao, Renliang

    2004-05-01

    A contour tree is a good graphical tool for representing the spatial relations of contour lines and has found many applications in map generalization, map annotation, terrain analysis, etc. A new approach for generating contour trees by introducing a Voronoi-based interior adjacency set concept is proposed in this paper. The immediate interior adjacency set is employed to identify all of the children contours of each contour without contour elevations. It has advantages over existing methods such as the point-in-polygon method and the region growing-based method. This new approach can be used for spatial data mining and knowledge discovering, such as the automatic extraction of terrain features and construction of multi-resolution digital elevation model.

  1. Clinical evaluation of atlas and deep learning based automatic contouring for lung cancer.

    Science.gov (United States)

    Lustberg, Tim; van Soest, Johan; Gooding, Mark; Peressutti, Devis; Aljabar, Paul; van der Stoep, Judith; van Elmpt, Wouter; Dekker, Andre

    2018-02-01

    Contouring of organs at risk (OARs) is an important but time consuming part of radiotherapy treatment planning. The aim of this study was to investigate whether using institutional created software-generated contouring will save time if used as a starting point for manual OAR contouring for lung cancer patients. Twenty CT scans of stage I-III NSCLC patients were used to compare user adjusted contours after an atlas-based and deep learning contour, against manual delineation. The lungs, esophagus, spinal cord, heart and mediastinum were contoured for this study. The time to perform the manual tasks was recorded. With a median time of 20 min for manual contouring, the total median time saved was 7.8 min when using atlas-based contouring and 10 min for deep learning contouring. Both atlas based and deep learning adjustment times were significantly lower than manual contouring time for all OARs except for the left lung and esophagus of the atlas based contouring. User adjustment of software generated contours is a viable strategy to reduce contouring time of OARs for lung radiotherapy while conforming to local clinical standards. In addition, deep learning contouring shows promising results compared to existing solutions. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  2. Auto-propagation of contours for adaptive prostate radiation therapy

    International Nuclear Information System (INIS)

    Chao Ming; Xie Yaoqin; Xing Lei

    2008-01-01

    The purpose of this work is to develop an effective technique to automatically propagate contours from planning CT to cone beam CT (CBCT) to facilitate CBCT-guided prostate adaptive radiation therapy. Different from other disease sites, such as the lungs, the contour mapping here is complicated by two factors: (i) the physical one-to-one correspondence may not exist due to the insertion or removal of some image contents within the region of interest (ROI); and (ii) reduced contrast to noise ratio of the CBCT images due to increased scatter. To overcome these issues, we investigate a strategy of excluding the regions with variable contents by a careful design of a narrow shell signifying the contour of an ROI. For rectum, for example, a narrow shell with the delineated contours as its interior surface was constructed to avoid the adverse influence of the day-to-day content change inside the rectum on the contour mapping. The corresponding contours in the CBCT were found by warping the narrow shell through the use of BSpline deformable model. Both digital phantom experiments and clinical case testing were carried out to validate the proposed ROI mapping method. It was found that the approach was able to reliably warp the constructed narrow band with an accuracy better than 1.3 mm. For all five clinical cases enrolled in this study, the method yielded satisfactory results even when there were significant rectal content changes between the planning CT and CBCT scans. The overlapped area of the auto-mapped contours over 90% to the manually drawn contours is readily achievable. The proposed approach permits us to take advantage of the regional calculation algorithm yet avoiding the nuisance of rectum/bladder filling and provide a useful tool for adaptive radiotherapy of prostate in the future

  3. Auto-propagation of contours for adaptive prostate radiation therapy

    Science.gov (United States)

    Chao, Ming; Xie, Yaoqin; Xing, Lei

    2008-09-01

    The purpose of this work is to develop an effective technique to automatically propagate contours from planning CT to cone beam CT (CBCT) to facilitate CBCT-guided prostate adaptive radiation therapy. Different from other disease sites, such as the lungs, the contour mapping here is complicated by two factors: (i) the physical one-to-one correspondence may not exist due to the insertion or removal of some image contents within the region of interest (ROI); and (ii) reduced contrast to noise ratio of the CBCT images due to increased scatter. To overcome these issues, we investigate a strategy of excluding the regions with variable contents by a careful design of a narrow shell signifying the contour of an ROI. For rectum, for example, a narrow shell with the delineated contours as its interior surface was constructed to avoid the adverse influence of the day-to-day content change inside the rectum on the contour mapping. The corresponding contours in the CBCT were found by warping the narrow shell through the use of BSpline deformable model. Both digital phantom experiments and clinical case testing were carried out to validate the proposed ROI mapping method. It was found that the approach was able to reliably warp the constructed narrow band with an accuracy better than 1.3 mm. For all five clinical cases enrolled in this study, the method yielded satisfactory results even when there were significant rectal content changes between the planning CT and CBCT scans. The overlapped area of the auto-mapped contours over 90% to the manually drawn contours is readily achievable. The proposed approach permits us to take advantage of the regional calculation algorithm yet avoiding the nuisance of rectum/bladder filling and provide a useful tool for adaptive radiotherapy of prostate in the future.

  4. Auto-propagation of contours for adaptive prostate radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Chao Ming; Xie Yaoqin; Xing Lei [Department of Radiation Oncology, Stanford University School of Medicine, 875 Blake Wilbur Drive, Stanford, CA 94305-5847 (United States)], E-mail: lei@reyes.stanford.edu

    2008-09-07

    The purpose of this work is to develop an effective technique to automatically propagate contours from planning CT to cone beam CT (CBCT) to facilitate CBCT-guided prostate adaptive radiation therapy. Different from other disease sites, such as the lungs, the contour mapping here is complicated by two factors: (i) the physical one-to-one correspondence may not exist due to the insertion or removal of some image contents within the region of interest (ROI); and (ii) reduced contrast to noise ratio of the CBCT images due to increased scatter. To overcome these issues, we investigate a strategy of excluding the regions with variable contents by a careful design of a narrow shell signifying the contour of an ROI. For rectum, for example, a narrow shell with the delineated contours as its interior surface was constructed to avoid the adverse influence of the day-to-day content change inside the rectum on the contour mapping. The corresponding contours in the CBCT were found by warping the narrow shell through the use of BSpline deformable model. Both digital phantom experiments and clinical case testing were carried out to validate the proposed ROI mapping method. It was found that the approach was able to reliably warp the constructed narrow band with an accuracy better than 1.3 mm. For all five clinical cases enrolled in this study, the method yielded satisfactory results even when there were significant rectal content changes between the planning CT and CBCT scans. The overlapped area of the auto-mapped contours over 90% to the manually drawn contours is readily achievable. The proposed approach permits us to take advantage of the regional calculation algorithm yet avoiding the nuisance of rectum/bladder filling and provide a useful tool for adaptive radiotherapy of prostate in the future.

  5. Automatic Approach for Lung Segmentation with Juxta-Pleural Nodules from Thoracic CT Based on Contour Tracing and Correction

    Directory of Open Access Journals (Sweden)

    Jinke Wang

    2016-01-01

    Full Text Available This paper presents a fully automatic framework for lung segmentation, in which juxta-pleural nodule problem is brought into strong focus. The proposed scheme consists of three phases: skin boundary detection, rough segmentation of lung contour, and pulmonary parenchyma refinement. Firstly, chest skin boundary is extracted through image aligning, morphology operation, and connective region analysis. Secondly, diagonal-based border tracing is implemented for lung contour segmentation, with maximum cost path algorithm used for separating the left and right lungs. Finally, by arc-based border smoothing and concave-based border correction, the refined pulmonary parenchyma is obtained. The proposed scheme is evaluated on 45 volumes of chest scans, with volume difference (VD 11.15±69.63 cm3, volume overlap error (VOE 3.5057±1.3719%, average surface distance (ASD 0.7917±0.2741 mm, root mean square distance (RMSD 1.6957±0.6568 mm, maximum symmetric absolute surface distance (MSD 21.3430±8.1743 mm, and average time-cost 2 seconds per image. The preliminary results on accuracy and complexity prove that our scheme is a promising tool for lung segmentation with juxta-pleural nodules.

  6. Edge and line oriented contour detection : State of the art

    NARCIS (Netherlands)

    Papari, Giuseppe; Petkov, Nicolai

    We present an overview of various edge and line oriented approaches to contour detection that have been proposed in the last two decades. By edge and line oriented we mean methods that do not rely on segmentation. Distinction is made between edges and contours. Contour detectors are divided in local

  7. The Oskar Klein memorial lectures

    CERN Document Server

    1994-01-01

    The series of Oskar Klein Memorial Lectures is a must-read for those keenly involved or simply interested in exploring the many fascinating aspects of Physics. This volume presents two landmark lectures given by Hans Bethe in October 1990 and Alan H. Guth in June 1991 under the series of Oskar Klein Memorial Lectures. Hans Bethe's lectures dealt with two themes: the astrophysical importance of neutrinos in supernova outbursts and a theoretical account of neutrinos through observations of the neutrino flux from the centre of the sun. Anyone interested in understanding the processes involved in

  8. Lecture Attendance and Web Based Lecture Technologies: A Comparison of Student Perceptions and Usage Patterns

    Science.gov (United States)

    von Konsky, Brian R.; Ivins, Jim; Gribble, Susan J.

    2009-01-01

    This paper investigates the impact of web based lecture recordings on learning and attendance at lectures. Student opinions regarding the perceived value of the recordings were evaluated in the context of usage patterns and final marks, and compared with attendance data and student perceptions regarding the usefulness of lectures. The availability…

  9. An investigation into positron emission tomography contouring methods across two treatment planning systems

    International Nuclear Information System (INIS)

    Young, Tony; Som, Seu; Sathiakumar, Chithradevi; Holloway, Lois

    2013-01-01

    Positron emission tomography (PET) imaging has been used to provide additional information regarding patient tumor location, size, and staging for radiotherapy treatment planning purposes. This additional information reduces interobserver variability and produces more consistent contouring. It is well recognized that different contouring methodology for PET data results in different contoured volumes. The goal of this study was to compare the difference in PET contouring methods for 2 different treatment planning systems using a phantom dataset and a series of patient datasets. Contouring methodology was compared on the ADAC Pinnacle Treatment Planning System and the CMS XiO Treatment Planning System. Contours were completed on the phantom and patient datasets using a number of PET contouring methods—the standardized uptake value 2.5 method, 30%, 40%, and 50% of the maximum uptake method and the signal to background ratio method. Differences of >15% were observed for PET-contoured volumes between the different treatment planning systems for the same data and the same PET contouring methodology. Contoured volume differences between treatment planning systems were caused by differences in data formatting and display and the different contouring tools available. Differences in treatment planning system as well as contouring methodology should be considered carefully in dose-volume contouring and reporting, especially between centers that may use different treatment planning systems or those that have several different treatment planning systems

  10. A new template matching method based on contour information

    Science.gov (United States)

    Cai, Huiying; Zhu, Feng; Wu, Qingxiao; Li, Sicong

    2014-11-01

    Template matching is a significant approach in machine vision due to its effectiveness and robustness. However, most of the template matching methods are so time consuming that they can't be used to many real time applications. The closed contour matching method is a popular kind of template matching methods. This paper presents a new closed contour template matching method which is suitable for two dimensional objects. Coarse-to-fine searching strategy is used to improve the matching efficiency and a partial computation elimination scheme is proposed to further speed up the searching process. The method consists of offline model construction and online matching. In the process of model construction, triples and distance image are obtained from the template image. A certain number of triples which are composed by three points are created from the contour information that is extracted from the template image. The rule to select the three points is that the template contour is divided equally into three parts by these points. The distance image is obtained here by distance transform. Each point on the distance image represents the nearest distance between current point and the points on the template contour. During the process of matching, triples of the searching image are created with the same rule as the triples of the model. Through the similarity that is invariant to rotation, translation and scaling between triangles, the triples corresponding to the triples of the model are found. Then we can obtain the initial RST (rotation, translation and scaling) parameters mapping the searching contour to the template contour. In order to speed up the searching process, the points on the searching contour are sampled to reduce the number of the triples. To verify the RST parameters, the searching contour is projected into the distance image, and the mean distance can be computed rapidly by simple operations of addition and multiplication. In the fine searching process

  11. Electron beam irradiating process for rendering rough or topographically irregular surface substrates smooth; and coated substrates produced thereby

    International Nuclear Information System (INIS)

    Nablo, S.V.

    1979-01-01

    This disclosure involves a novel process for instantaneous electron-beam curing of very thin low viscosity, solventless coating upon rough, irregular or textured surfaces of a substrate such as paper or the like. Through rather critical timing and energy adjustment procedures, the coating firmly adheres to the surface before the coating can conform to the roughness or texture contour or substantially penetrate into the surface. By this method a solidified very smooth outer surface is provided for the substrate that is particularly used for metalization and other finished layerings. (author)

  12. Model cortical association fields account for the time course and dependence on target complexity of human contour perception.

    Directory of Open Access Journals (Sweden)

    Vadas Gintautas

    2011-10-01

    Full Text Available Can lateral connectivity in the primary visual cortex account for the time dependence and intrinsic task difficulty of human contour detection? To answer this question, we created a synthetic image set that prevents sole reliance on either low-level visual features or high-level context for the detection of target objects. Rendered images consist of smoothly varying, globally aligned contour fragments (amoebas distributed among groups of randomly rotated fragments (clutter. The time course and accuracy of amoeba detection by humans was measured using a two-alternative forced choice protocol with self-reported confidence and variable image presentation time (20-200 ms, followed by an image mask optimized so as to interrupt visual processing. Measured psychometric functions were well fit by sigmoidal functions with exponential time constants of 30-91 ms, depending on amoeba complexity. Key aspects of the psychophysical experiments were accounted for by a computational network model, in which simulated responses across retinotopic arrays of orientation-selective elements were modulated by cortical association fields, represented as multiplicative kernels computed from the differences in pairwise edge statistics between target and distractor images. Comparing the experimental and the computational results suggests that each iteration of the lateral interactions takes at least [Formula: see text] ms of cortical processing time. Our results provide evidence that cortical association fields between orientation selective elements in early visual areas can account for important temporal and task-dependent aspects of the psychometric curves characterizing human contour perception, with the remaining discrepancies postulated to arise from the influence of higher cortical areas.

  13. The psychological impact of body contouring surgery

    DEFF Research Database (Denmark)

    Mikkelsen Lorenzen, Mike; Poulsen, Lotte; Poulsen, Signe

    2018-01-01

    INTRODUCTION: Body contouring surgery is associated with changes in body image and identity. The primary aim of the study was to investigate a multidisciplinary assessment of potential psychological challenges before and after body contouring surgery. METHODS: Eight pre- and post-operative patients...... relevant codes had been extracted. RESULTS: A total of seven psychological themes were iden- tified, indicating that surgery alone cannot improve the pa- tients’ psychological difficulties and that psychological care and management of the expected discomfort and body im- age is of considerable importance...... in providing continuity of care. CONCLUSIONS: The reported quality of life is of consider- able importance to patients undergoing body contouring surgery after massive weight loss. Our findings may provide useful information for surgeons and healthcare profes- sionals allowing them to develop patient education...

  14. Effect Of Accounting Lecturer Lecturer Commitment To The Development Of Professional Accounting Empirical Study Lecturer Accounting Faculty Of Economics University Of Muhammadiyah Tangerang 2013

    Directory of Open Access Journals (Sweden)

    Endraria

    2015-04-01

    Full Text Available Abstract The purpose of the study in which the researcher is interested in conducting research by taking the title The Effect of Commitment Against Lecturer - Lecturer in Accounting Accounting Profession Development Empirical Study of Accounting Lecturer Faculty of Economics University of Muhammadiyah Tangerang in 2013 . This research was conducted at the Faculty of Economics University of Muhammadiyah Tangerang is located at Independence Pioneer Road I No.33 Cikokol Tangerang City. The experiment was conducted at the research site easily accessible for the author. The method used in this research is descriptive quantitative methods which aim to describe the descriptive method of data distribution of each variable.There are significant accounting lecturers commitment to the development of the accounting profession Empirical Study of Accounting Lecturer Faculty of Economics University of Muhammadiyah Tangerang in 2013 this is evidenced by the results of hypothesis testing that has been done obtained tcount ttable value 5.7193 and with a significance level of 5 and df n - 2 40-2 38 is equal to 1.686 with the statement concluded that t count t table. Thus Ha Ho accepted and rejected. The conclusion was that there are significant accounting lecturers commitment to the development of the accounting profession Empirical Study of Accounting Lecturer Faculty of Economics University of Muhammadiyah Tangerang in 2013. As for advice to be conveyed in this study is the government as a regulator should be able to evaluate the development of the accounting profession especially in Indonesia with the influence of commitment accounting lecturers are expected to improve and develop the accounting profession especially in the Faculty of Economics University of Muhammadiyah Tangerang.

  15. Contouring algorithm for two dimensional data- an application to airborne surveys

    International Nuclear Information System (INIS)

    Suryakumar, N.V.; Rohatgi, Savita; Raghuwanshi, S.S.

    1994-01-01

    The paper describes in general the contouring algorithm for two dimensional projection of aeroradiometric data and considers not only irregularly spaced flight lines but also solves the other problems related to voluminous data acquired during the airborne surveys. Several simple logics have been described for drawing the contours using scan method and taking care of annotations, identification marking, geographical locations, map size, contour density for visual distinctness and many such problems which may arise during contouring. The present paper also discusses various possibilities of contour line segments in the mini-grid and the criterion for selection of suitable segments has been described in detail. A novel approach to avoid the crossing of contours or missing data is also briefly discussed. The simplicity of the algorithm is mentioned for its ready implementation or any computer/plotter. (author). 8 refs., 8 figs

  16. Visual search of illusory contours: Shape and orientation effects

    Directory of Open Access Journals (Sweden)

    Gvozdenović Vasilije

    2008-01-01

    Full Text Available Illusory contours are specific class of visual stimuli that represent stimuli configurations perceived as integral irrespective of the fact that they are given in fragmented uncompleted wholes. Due to their specific features, illusory contours gained much attention in last decade representing prototype of stimuli used in investigations focused on binding problem. On the other side, investigations of illusory contours are related to problem of the level of their visual processing. Neurophysiologic studies show that processing of illusory contours proceed relatively early, on the V2 level, on the other hand most of experimental studies claim that illusory contours are perceived with engagement of visual attention, binding their elements to whole percept. This research is focused on two experiments in which visual search of illusory contours are based on shape and orientation. The main experimental procedure evolved the task proposed by Bravo and Nakayama where instead of detection, subjects were performing identification of one among two possible targets. In the first experiment subjects detected the presence of illusory square or illusory triangle, while in the second experiment subject were detecting two different orientations of illusory triangle. The results are interpreted in terms of visual search and feature integration theory. Beside the type of visual search task, search type proved to be dependent of specific features of illusory shapes which further complicate theoretical interpretation of the level of their perception.

  17. Holographic Moire Contouring

    Science.gov (United States)

    Sciammarella, C. A.; Sainov, Ventseslav; Simova, Eli

    1990-04-01

    Theoretical analysis and experimental results on holographic moire contouring (HMC) of difussely reflecting objects are presented. The sensitivity and application constraints of the method are discussed. A high signal-to-noise ratio and contrast of the fringes is achieved through the use of high quality silver halide holographic plates HP-650. A good agreement between theoretical and experimental results is observed.

  18. Lectures in medical educaton: what students think?

    Science.gov (United States)

    Mustafa, Tajammal; Farooq, Zerwa; Asad, Zunaira; Amjad, Rabbia; Badar, Iffat; Chaudhry, Abdul Majeed; Khan, Mohammad Amer Zaman; Rafique, Farida

    2014-01-01

    The volume of medical knowledge has increased exponentially and so has the need to improve the efficiency of current teaching practices.With increasing emphasis on interactive and problem based learning, the place of lectures in modern medical education has become a questionable issue. Objectives were to assess the perspective of undergraduate medical students regarding the role and effectiveness of lectures as a mode of instruction as well as the ways and means that can be employed to enhance the effectiveness of lectures. A cross sectional study was carried out among 2nd to final year medical students from five medical colleges including both private and public sector institutions. A total of 347 students participated by completing a structured questionnaire. Data was analyzed using SPSS-17. Sixty seven percent students considered lectures as a useful mode of instruction (47% males and 77% females), whereas 83% of the students reported that clinical sessions were superior to lectures because of small number of students in clinical sessions, active student participation, enhanced clinical orientation, and interaction with patients. About 64% responded that lectures should be replaced by clinical sessions. Majority of the students (92%) reported not being able to concentrate during a lecture beyond 30 minutes, whereas 70% skipped lectures as they were boring. A significantly greater proportion of male respondents, students from clinical years, and those who skipped lectures, considered lectures to be boring, a poor utilization of time and resources, and could not concentrate for the full duration of a lecture compared to females, students from preclinical years, and those who do not skip lectures, respectively. Lecturing techniques need to be improvised. The traditional passive mode of instruction has to be replaced with active learning and inquiry based approach to adequately utilize the time and resources spent on lectures.

  19. A review of methods of analysis in contouring studies for radiation oncology

    International Nuclear Information System (INIS)

    Jameson, Michael G.; Holloway, Lois C.; Metcalfe, Peter E.; Vial, Philip J.; Vinod, Shalini K.

    2010-01-01

    Full text: Inter-observer variability in anatomical contouring is the biggest contributor to uncertainty in radiation treatment planning. Contouring studies are frequently performed to investigate the differences between multiple contours on common datasets. There is, however, no widely accepted method for contour comparisons. The purpose of this study is to review the literature on contouring studies in the context of radiation oncology, with particular consideration of the contouring comparison methods they employ. A literature search, not limited by date, was conducted using Medline and Google Scholar with key words; contour, variation, delineation, inter/intra observer, uncertainty and trial dummy-run. This review includes a description of the contouring processes and contour comparison metrics used. The use of different processes and metrics according to tumour site and other factors were also investigated with limitations described. A total of 69 relevant studies were identified. The most common tumour sites were prostate (26), lung (10), head and neck cancers (8) and breast (7).The most common metric of comparison was volume used 59 times, followed by dimension and shape used 36 times, and centre of volume used 19 times. Of all 69 publications, 67 used a combination of metrics and two used only one metric for comparison. No clear relationships between tumour site or any other factors that may in Auence the contouring process and the metrics used to compare contours were observed from the literature. Further studies are needed to assess the advantages and disadvantages of each metric in various situations.

  20. Subsidence Contours for South Louisiana; UTM 15N NAD83; LRA (2005); [subsidence_contours

    Data.gov (United States)

    Louisiana Geographic Information Center — The GIS data shapefile represents average subsidence contour intervals (0.02 cm/year over 10,000 years) for Coastal LA derived from the following: Kulp, M.A., 2000,...

  1. The use of recorded lectures in education and the impact on lecture attendance and exam performance

    NARCIS (Netherlands)

    Bos, Nynke; Groeneveld, Caspar; Van Bruggen, Jan; Brand-Gruwel, Saskia

    2017-01-01

    Universities increasingly record lectures and make them available online for students. Though the technology to record these lectures is now solidly implemented and embed- ded in many institutions, the impact of the usage of recorded lectures on exam perfor- mance is not clear. The purpose of the

  2. Statistical Modeling Approach to Quantitative Analysis of Interobserver Variability in Breast Contouring

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jinzhong, E-mail: jyang4@mdanderson.org [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Woodward, Wendy A.; Reed, Valerie K.; Strom, Eric A.; Perkins, George H.; Tereffe, Welela; Buchholz, Thomas A. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Zhang, Lifei; Balter, Peter; Court, Laurence E. [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Li, X. Allen [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States); Dong, Lei [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Scripps Proton Therapy Center, San Diego, California (United States)

    2014-05-01

    Purpose: To develop a new approach for interobserver variability analysis. Methods and Materials: Eight radiation oncologists specializing in breast cancer radiation therapy delineated a patient's left breast “from scratch” and from a template that was generated using deformable image registration. Three of the radiation oncologists had previously received training in Radiation Therapy Oncology Group consensus contouring for breast cancer atlas. The simultaneous truth and performance level estimation algorithm was applied to the 8 contours delineated “from scratch” to produce a group consensus contour. Individual Jaccard scores were fitted to a beta distribution model. We also applied this analysis to 2 or more patients, which were contoured by 9 breast radiation oncologists from 8 institutions. Results: The beta distribution model had a mean of 86.2%, standard deviation (SD) of ±5.9%, a skewness of −0.7, and excess kurtosis of 0.55, exemplifying broad interobserver variability. The 3 RTOG-trained physicians had higher agreement scores than average, indicating that their contours were close to the group consensus contour. One physician had high sensitivity but lower specificity than the others, which implies that this physician tended to contour a structure larger than those of the others. Two other physicians had low sensitivity but specificity similar to the others, which implies that they tended to contour a structure smaller than the others. With this information, they could adjust their contouring practice to be more consistent with others if desired. When contouring from the template, the beta distribution model had a mean of 92.3%, SD ± 3.4%, skewness of −0.79, and excess kurtosis of 0.83, which indicated a much better consistency among individual contours. Similar results were obtained for the analysis of 2 additional patients. Conclusions: The proposed statistical approach was able to measure interobserver variability quantitatively

  3. Three dimensional mathematical modeling of violin plate surfaces: An approach based on an ensemble of contour lines.

    Science.gov (United States)

    Piantadosi, Steven

    2017-01-01

    This paper presents an approach to describing the three dimensional shape of a violin plate in mathematical form. The shape description begins with standard contour lines and ends with an equation for a surface in three dimensional space. The traditional specification of cross sectional arching is unnecessary. Advantages of this approach are that it employs simple and universal description of plate geometry and yields a complete, smoothed, precise mathematical equation of the plate that is suitable for modern three dimensional production. It is quite general and suitable for both exterior and interior plate surfaces, yielding the ability to control thicknesses along with shape. This method can produce mathematical descriptions with tolerances easily less than 0.001 millimeters suitable for modern computerized numerical control carving and hand finishing.

  4. Lectures on the inverse scattering method

    International Nuclear Information System (INIS)

    Zakharov, V.E.

    1983-06-01

    In a series of six lectures an elementary introduction to the theory of inverse scattering is given. The first four lectures contain a detailed theory of solitons in the framework of the KdV equation, together with the inverse scattering theory of the one-dimensional Schroedinger equation. In the fifth lecture the dressing method is described, while the sixth lecture gives a brief review of the equations soluble by the inverse scattering method. (author)

  5. Brightness/darkness induction and the genesis of a contour

    Directory of Open Access Journals (Sweden)

    Sergio eRoncato

    2014-10-01

    Full Text Available Visual contours often result from the integration or interpolation of fragmented edges.The strength of the completion increases when the edges share the same contrast polarity (CP. Here we demonstrate that the appearance in the perceptual field of this integrated unit, or contour of invariant CP, is concomitant with a vivid brightness alteration of the surfaces at its opposite sides. To observe this effect requires some stratagems because the formation in the visual field of a contour of invariant CP normally engenders the formation of a second contour and then the rise of two streams of induction signals that interfere in different ways. Particular configurations have been introduced that allow us to observe the induction effects of one contour taken in isolation. I documented these effects by phenomenological observations and psychophysical measurement of the brightness alteration in relation to luminance contrast. When the edges of the same CP complete to form a contour, the background of homogeneous luminance appears to dim at one side and to brighten at the opposite side (in accord with the CP. The strength of the phenomenon is proportional to the local luminance contrast. This effect weakens or nulls when the contour of the invariant CP separates surfaces filled with different grey shades.These conflicting results stimulate a deeper exploration of the induction phenomena and their role in the computation of brightness contrast. An alternative perspective is offered to account for some brightness illusions and their relation to the phenomenal transparency. The main assumption asserts that, when in the same region induction signals of opposite CP overlap, the filling-in are blocked unless the image is stratified into different layers, one for each signal of the same polarity. Phenomenological observations document this solution by the visual system

  6. Color contributes to object-contour perception in natural scenes.

    Science.gov (United States)

    Hansen, Thorsten; Gegenfurtner, Karl R

    2017-03-01

    The magnitudes of chromatic and achromatic edge contrast are statistically independent and thus provide independent information, which can be used for object-contour perception. However, it is unclear if and how much object-contour perception benefits from chromatic edge contrast. To address this question, we investigated how well human-marked object contours can be predicted from achromatic and chromatic edge contrast. We used four data sets of human-marked object contours with a total of 824 images. We converted the images to the Derrington-Krauskopf-Lennie color space to separate chromatic from achromatic information in a physiologically meaningful way. Edges were detected in the three dimensions of the color space (one achromatic and two chromatic) and compared to human-marked object contours using receiver operating-characteristic (ROC) analysis for a threshold-independent evaluation. Performance was quantified by the difference of the area under the ROC curves (ΔAUC). Results were consistent across different data sets and edge-detection methods. If chromatic edges were used in addition to achromatic edges, predictions were better for 83% of the images, with a prediction advantage of 3.5% ΔAUC, averaged across all data sets and edge detectors. For some images the prediction advantage was considerably higher, up to 52% ΔAUC. Interestingly, if achromatic edges were used in addition to chromatic edges, the average prediction advantage was smaller (2.4% ΔAUC). We interpret our results such that chromatic information is important for object-contour perception.

  7. Redefining face contour with a novel anti-aging cosmetic product: an open-label, prospective clinical study.

    Science.gov (United States)

    Garre, Aurora; Martinez-Masana, Gemma; Piquero-Casals, Jaime; Granger, Corinne

    2017-01-01

    Skin aging is accelerated by multiple extrinsic factors: ultraviolet radiation, smoking and pollution increase oxidative activity, damaging cellular and extracellular components such as DNA, proteins, and lipids. With age, collagen and hyaluronic acid levels decline, resulting in loss of elasticity and moisture of the skin. Over time this damage leads to characteristic signs that make the skin look older: altered facial contour, sagging skin, wrinkles, and an uneven complexion. This study evaluated the anti-aging effects of a new facial cream formulated with carnosine, Alteromonas ferment extract, crosspolymer hyaluronic acid, and a tripeptide. An open-label intra-individual study to assess the anti-aging efficacy of the investigational product in 33 women aged 45 to 65 years. The product was applied twice daily for 56 days. Facial contour and skin deformation, elasticity, hydration, and complexion were measured with specialized equipment at baseline and days 28 and 56. Additionally, subjects completed questionnaires at days 28 and 56 on the perceived efficacy and cosmetic characteristics of the product. After 56 days of use of the investigational product, a redefining effect was observed, with a significant decrease in sagging jawline (7%). Skin was significantly more hydrated (12%), firmer (29%), and more elastic (20%) ( P <0.001 for all). On complexion assessment, skin texture (a measure of skin smoothness) and spots (brown and red skin lesions) also improved significantly (12% and 6% decrease, respectively). In the subjective self-evaluation, the majority of subjects reported that the skin was visibly tightened and more elastic, flexible, and moisturized (91%, 88%, 91%, and 90%, respectively). The product was well tolerated with no adverse events reported during the study. This new cosmetic product demonstrated anti-aging effects after 56 days of use, most notably a redefined facial contour and improved complexion. It is a safe and effective anti-aging product.

  8. Parallel peak pruning for scalable SMP contour tree computation

    Energy Technology Data Exchange (ETDEWEB)

    Carr, Hamish A. [Univ. of Leeds (United Kingdom); Weber, Gunther H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Davis, CA (United States); Sewell, Christopher M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ahrens, James P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-09

    As data sets grow to exascale, automated data analysis and visualisation are increasingly important, to intermediate human understanding and to reduce demands on disk storage via in situ analysis. Trends in architecture of high performance computing systems necessitate analysis algorithms to make effective use of combinations of massively multicore and distributed systems. One of the principal analytic tools is the contour tree, which analyses relationships between contours to identify features of more than local importance. Unfortunately, the predominant algorithms for computing the contour tree are explicitly serial, and founded on serial metaphors, which has limited the scalability of this form of analysis. While there is some work on distributed contour tree computation, and separately on hybrid GPU-CPU computation, there is no efficient algorithm with strong formal guarantees on performance allied with fast practical performance. Here in this paper, we report the first shared SMP algorithm for fully parallel contour tree computation, withfor-mal guarantees of O(lgnlgt) parallel steps and O(n lgn) work, and implementations with up to 10x parallel speed up in OpenMP and up to 50x speed up in NVIDIA Thrust.

  9. CT liver volumetry using geodesic active contour segmentation with a level-set algorithm

    Science.gov (United States)

    Suzuki, Kenji; Epstein, Mark L.; Kohlbrenner, Ryan; Obajuluwa, Ademola; Xu, Jianwu; Hori, Masatoshi; Baron, Richard

    2010-03-01

    Automatic liver segmentation on CT images is challenging because the liver often abuts other organs of a similar density. Our purpose was to develop an accurate automated liver segmentation scheme for measuring liver volumes. We developed an automated volumetry scheme for the liver in CT based on a 5 step schema. First, an anisotropic smoothing filter was applied to portal-venous phase CT images to remove noise while preserving the liver structure, followed by an edge enhancer to enhance the liver boundary. By using the boundary-enhanced image as a speed function, a fastmarching algorithm generated an initial surface that roughly estimated the liver shape. A geodesic-active-contour segmentation algorithm coupled with level-set contour-evolution refined the initial surface so as to more precisely fit the liver boundary. The liver volume was calculated based on the refined liver surface. Hepatic CT scans of eighteen prospective liver donors were obtained under a liver transplant protocol with a multi-detector CT system. Automated liver volumes obtained were compared with those manually traced by a radiologist, used as "gold standard." The mean liver volume obtained with our scheme was 1,520 cc, whereas the mean manual volume was 1,486 cc, with the mean absolute difference of 104 cc (7.0%). CT liver volumetrics based on an automated scheme agreed excellently with "goldstandard" manual volumetrics (intra-class correlation coefficient was 0.95) with no statistically significant difference (p(F<=f)=0.32), and required substantially less completion time. Our automated scheme provides an efficient and accurate way of measuring liver volumes.

  10. Deformation of contour and Hawking temperature

    International Nuclear Information System (INIS)

    Ding Chikun; Jing Jiliang

    2010-01-01

    It was found that, in an isotropic coordinate system, the tunneling approach brings a factor of 1/2 for the Hawking temperature of a Schwarzschild black hole. In this paper, we address this kind of problem by studying the relation between the Hawking temperature and the deformation of the integral contour for the scalar and Dirac particles tunneling. We find that the correct Hawking temperature can be obtained exactly as long as the integral contour deformed corresponding to the radial coordinate transform if the transformation is a non-regular or zero function at the event horizon.

  11. Color and Contour Based Identification of Stem of Coconut Bunch

    Science.gov (United States)

    Kannan Megalingam, Rajesh; Manoharan, Sakthiprasad K.; Reddy, Rajesh G.; Sriteja, Gone; Kashyap, Ashwin

    2017-08-01

    Vision is the key component of Artificial Intelligence and Automated Robotics. Sensors or Cameras are the sight organs for a robot. Only through this, they are able to locate themselves or identify the shape of a regular or an irregular object. This paper presents the method of Identification of an object based on color and contour recognition using a camera through digital image processing techniques for robotic applications. In order to identify the contour, shape matching technique is used, which takes the input data from the database provided, and uses it to identify the contour by checking for shape match. The shape match is based on the idea of iterating through each contour of the threshold image. The color is identified on HSV Scale, by approximating the desired range of values from the database. HSV data along with iteration is used for identifying a quadrilateral, which is our required contour. This algorithm could also be used in a non-deterministic plane, which only uses HSV values exclusively.

  12. Some distinguishing characteristics of contour and texture phenomena in images

    Science.gov (United States)

    Jobson, Daniel J.

    1992-01-01

    The development of generalized contour/texture discrimination techniques is a central element necessary for machine vision recognition and interpretation of arbitrary images. Here, the visual perception of texture, selected studies of texture analysis in machine vision, and diverse small samples of contour and texture are all used to provide insights into the fundamental characteristics of contour and texture. From these, an experimental discrimination scheme is developed and tested on a battery of natural images. The visual perception of texture defined fine texture as a subclass which is interpreted as shading and is distinct from coarse figural similarity textures. Also, perception defined the smallest scale for contour/texture discrimination as eight to nine visual acuity units. Three contour/texture discrimination parameters were found to be moderately successful for this scale discrimination: (1) lightness change in a blurred version of the image, (2) change in lightness change in the original image, and (3) percent change in edge counts relative to local maximum.

  13. Automatic programming of grinding robot restoration of contours

    OpenAIRE

    Are Willersrud; Fred Godtliebsen; Trygve Thomessen

    1995-01-01

    A new programming method has been developed for grinding robots. Instead of using the conventional jog-and-teach method, the workpiece contour is automatically tracked by the robot. During the tracking, the robot position is stored in the robot control system every 8th millisecond. After filtering and reducing this contour data, a robot program is automatically generated.

  14. Metallurgy department publications and lectures 1987

    International Nuclear Information System (INIS)

    Schroeder Pedersen, A.; Bilde-Soerensen, J.B.

    1988-04-01

    A presentation (including abstract) of scientific and technical publications and lectures by the staff of the Metallurgy Department during 1987 is given. The list comprises journal papers, conference papers, reports, lectures and poster presentations in the following categories: Publications, Lectures and Poster Presentations. (author)

  15. Online Lecture Recordings and Lecture Attendance: Investigating Student Preferences in a Large First Year Psychology Course

    Science.gov (United States)

    Yeung, Alexandra; Raju, Sadhana; Sharma, Manjula D.

    2016-01-01

    While blended learning has been around for some time, the interplay between lecture recordings, lecture attendance and grades needs further examination particularly for large cohorts of over 1,000 students in 500 seat lecture theatres. This paper reports on such an investigation with a cohort of 1,450 first year psychology students' who indicated…

  16. The Use of Recorded Lectures in Education and the Impact on Lecture Attendance and Exam Performance

    Science.gov (United States)

    Bos, Nynke; Groeneveld, Caspar; van Bruggen, Jan; Brand-Gruwel, Saskia

    2016-01-01

    Universities increasingly record lectures and make them available online for students. Though the technology to record these lectures is now solidly implemented and embedded in many institutions, the impact of the usage of recorded lectures on exam performance is not clear. The purpose of the current study is to address the use of recorded…

  17. Explicit constructivism: a missing link in ineffective lectures?

    Science.gov (United States)

    Prakash, E S

    2010-06-01

    This study tested the possibility that interactive lectures explicitly based on activating learners' prior knowledge and driven by a series of logical questions might enhance the effectiveness of lectures. A class of 54 students doing the respiratory system course in the second year of the Bachelor of Medicine and Bachelor of Surgery program in my university was randomized to two groups to receive one of two types of lectures, "typical" lectures (n = 28, 18 women and 10 men) or "constructivist" lectures (n = 26, 19 women and 7 men), on the same topic: the regulation of respiration. Student pretest scores in the two groups were comparable (P > 0.1). Students that received the constructivist lectures did much better in the posttest conducted immediately after the lectures (6.8 +/- 3.4 for constructivist lectures vs. 4.2 +/- 2.3 for typical lectures, means +/- SD, P = 0.004). Although both types of lectures were well received, students that received the constructivist lectures appeared to have been more satisfied with their learning experience. However, on a posttest conducted 4 mo later, scores obtained by students in the two groups were not any different (6.9 +/- 3 for constructivist lectures vs. 6.9 +/- 3.7 for typical lectures, P = 0.94). This study adds to the increasing body of evidence that there is a case for the use of interactive lectures that make the construction of knowledge and understanding explicit, easy, and enjoyable to learners.

  18. Object segmentation using graph cuts and active contours in a pyramidal framework

    Science.gov (United States)

    Subudhi, Priyambada; Mukhopadhyay, Susanta

    2018-03-01

    Graph cuts and active contours are two very popular interactive object segmentation techniques in the field of computer vision and image processing. However, both these approaches have their own well-known limitations. Graph cut methods perform efficiently giving global optimal segmentation result for smaller images. However, for larger images, huge graphs need to be constructed which not only takes an unacceptable amount of memory but also increases the time required for segmentation to a great extent. On the other hand, in case of active contours, initial contour selection plays an important role in the accuracy of the segmentation. So a proper selection of initial contour may improve the complexity as well as the accuracy of the result. In this paper, we have tried to combine these two approaches to overcome their above-mentioned drawbacks and develop a fast technique of object segmentation. Here, we have used a pyramidal framework and applied the mincut/maxflow algorithm on the lowest resolution image with the least number of seed points possible which will be very fast due to the smaller size of the image. Then, the obtained segmentation contour is super-sampled and and worked as the initial contour for the next higher resolution image. As the initial contour is very close to the actual contour, so fewer number of iterations will be required for the convergence of the contour. The process is repeated for all the high-resolution images and experimental results show that our approach is faster as well as memory efficient as compare to both graph cut or active contour segmentation alone.

  19. Perceptual representation and effectiveness of local figure?ground cues in natural contours

    OpenAIRE

    Sakai, Ko; Matsuoka, Shouhei; Kurematsu, Ken; Hatori, Yasuhiro

    2015-01-01

    A contour shape strongly influences the perceptual segregation of a figure from the ground. We investigated the contribution of local contour shape to figure–ground segregation. Although previous studies have reported local contour features that evoke figure–ground perception, they were often image features and not necessarily perceptual features. First, we examined whether contour features, specifically, convexity, closure, and symmetry, underlie the perceptual representation of natural cont...

  20. Flipped classroom or an active lecture?

    Science.gov (United States)

    Pickering, James D; Roberts, David J H

    2018-01-01

    Recent changes in anatomy education have seen the introduction of flipped classrooms as a replacement to the traditional didactic lecture. This approach utilizes the increasing availability of digital technology to create learning resources that can be accessed prior to attending class, with face-to-face sessions then becoming more student-centered via discussion, collaborative learning, and problem-solving activities. Although this approach may appear intuitive, this viewpoint commentary presents a counter opinion and highlights a simple alternative that utilizes evidence-based active learning approaches as part of the traditional lecture. The active lecture takes the traditional lecture, and (1) ensures the lecture content is relevant and has clear objectives, (2) contains lecture material that is designed according to the latest evidence-base, (3) complements it with additional supplementary material, (4) creates space to check prior understanding and knowledge levels, and (5) utilizes suitable technology to facilitate continual engagement and interaction. Clin. Anat. 31:118-121, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  1. Redefining face contour with a novel anti-aging cosmetic product: an open-label, prospective clinical study

    Directory of Open Access Journals (Sweden)

    Garre A

    2017-11-01

    Full Text Available Aurora Garre,1 Gemma Martinez-Masana,1 Jaime Piquero-Casals,2 Corinne Granger1 1Innovation and Development, ISDIN S.A., Barcelona, Spain; 2Dermik Clinic, Barcelona, Spain Background: Skin aging is accelerated by multiple extrinsic factors: ultraviolet radiation, smoking and pollution increase oxidative activity, damaging cellular and extracellular components such as DNA, proteins, and lipids. With age, collagen and hyaluronic acid levels decline, resulting in loss of elasticity and moisture of the skin. Over time this damage leads to characteristic signs that make the skin look older: altered facial contour, sagging skin, wrinkles, and an uneven complexion. This study evaluated the anti-aging effects of a new facial cream formulated with carnosine, Alteromonas ferment extract, crosspolymer hyaluronic acid, and a tripeptide. Methods: An open-label intra-individual study to assess the anti-aging efficacy of the investigational product in 33 women aged 45 to 65 years. The product was applied twice daily for 56 days. Facial contour and skin deformation, elasticity, hydration, and complexion were measured with specialized equipment at baseline and days 28 and 56. Additionally, subjects completed questionnaires at days 28 and 56 on the perceived efficacy and cosmetic characteristics of the product. Results: After 56 days of use of the investigational product, a redefining effect was observed, with a significant decrease in sagging jawline (7%. Skin was significantly more hydrated (12%, firmer (29%, and more elastic (20% (P<0.001 for all. On complexion assessment, skin texture (a measure of skin smoothness and spots (brown and red skin lesions also improved significantly (12% and 6% decrease, respectively. In the subjective self-evaluation, the majority of subjects reported that the skin was visibly tightened and more elastic, flexible, and moisturized (91%, 88%, 91%, and 90%, respectively. The product was well tolerated with no adverse events reported

  2. Improving Lecture Quality through Training in Public Speaking

    Science.gov (United States)

    Mowbray, Robert; Perry, Laura B.

    2015-01-01

    Lecturing is a common instructional format but poor lecturing skills can detract from students' learning experiences and outcomes. As lecturing is essentially a form of public communication, training in public speaking may improve lecture quality. Twelve university lecturers in Malaysia participated in a six-week public speaking skills training…

  3. SU-E-J-129: Atlas Development for Cardiac Automatic Contouring Using Multi-Atlas Segmentation

    International Nuclear Information System (INIS)

    Zhou, R; Yang, J; Pan, T; Milgrom, S; Pinnix, C; Shi, A; Yang, J; Liu, Y; Nguyen, Q; Gomez, D; Dabaja, B; Balter, P; Court, L; Liao, Z

    2015-01-01

    Purpose: To develop a set of atlases for automatic contouring of cardiac structures to determine heart radiation dose and the associated toxicity. Methods: Six thoracic cancer patients with both contrast and non-contrast CT images were acquired for this study. Eight radiation oncologists manually and independently delineated cardiac contours on the non-contrast CT by referring to the fused contrast CT and following the RTOG 1106 atlas contouring guideline. Fifteen regions of interest (ROIs) were delineated, including heart, four chambers, four coronary arteries, pulmonary artery and vein, inferior and superior vena cava, and ascending and descending aorta. Individual expert contours were fused using the simultaneous truth and performance level estimation (STAPLE) algorithm for each ROI and each patient. The fused contours became atlases for an in-house multi-atlas segmentation. Using leave-one-out test, we generated auto-segmented contours for each ROI and each patient. The auto-segmented contours were compared with the fused contours using the Dice similarity coefficient (DSC) and the mean surface distance (MSD). Results: Inter-observer variability was not obvious for heart, chambers, and aorta but was large for other structures that were not clearly distinguishable on CT image. The average DSC between individual expert contours and the fused contours were less than 50% for coronary arteries and pulmonary vein, and the average MSD were greater than 4.0 mm. The largest MSD of expert contours deviating from the fused contours was 2.5 cm. The mean DSC and MSD of auto-segmented contours were within one standard deviation of expert contouring variability except the right coronary artery. The coronary arteries, vena cava, and pulmonary vein had DSC<70% and MSD>3.0 mm. Conclusion: A set of cardiac atlases was created for cardiac automatic contouring, the accuracy of which was comparable to the variability in expert contouring. However, substantial modification may need

  4. Consensus Recommendations for Radiation Therapy Contouring and Treatment of Vulvar Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Gaffney, David K., E-mail: david.gaffney@hci.utah.edu [Department of Radiation Oncology, Huntsman Cancer Hospital, Salt Lake City, Utah (United States); King, Bronwyn [Department of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre and Epworth Radiation Oncology, Melbourne, Victoria (Australia); Viswanathan, Akila N. [Department of Radiation Oncology, Dana-Farber/Brigham and Women' s Cancer Center, Harvard Medical School, Boston, Massachusetts (United States); Barkati, Maroie [Department of Radiation Oncology, Centre hospitalier de l' universite de Montreal, Montreal, Quebec (Canada); Beriwal, Sushil [Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania (United States); Eifel, Patricia [Department of Radiation Oncology, MD Anderson Cancer Center, Houston, Texas (United States); Erickson, Beth [Department of Radiation Oncology, Proedtert and Medical College Clinical Cancer Center, Milwaukee, Wisconsin (United States); Fyles, Anthony [Department of Radiation Oncology, Princess Margaret Cancer Centre, Toronto, Ontario (Canada); Goulart, Jennifer [Department of Radiation Oncology, British Columbia Cancer Agency, Victoria, British Columbia (Canada); Harkenrider, Matthew [Department of Radiation Oncology, Stritch School of Medicine, Loyola University, Maywood, Illinois (United States); Jhingran, Anuja; Klopp, Ann [Department of Radiation Oncology, MD Anderson Cancer Center, Houston, Texas (United States); Koh, Wui-Jin [Department of Radiation Oncology, University of Washington, Seattle, Washington (United States); Lim, Karen [Liverpool Cancer Therapy Centre, Radiation Oncology Unit, Sydney, New South Wales (Australia); Petersen, Ivy [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States); Portelance, Lorraine [Radiation Oncology Department, Miller School of Medicine, University of Miami, Miami, Florida (United States); and others

    2016-07-15

    Purpose: The purpose of this study was to develop a radiation therapy (RT) contouring atlas and recommendations for women with postoperative and locally advanced vulvar carcinoma. Methods and Materials: An international committee of 35 expert gynecologic radiation oncologists completed a survey of the treatment of vulvar carcinoma. An initial set of recommendations for contouring was discussed and generated by consensus. Two cases, 1 locally advanced and 1 postoperative, were contoured by 14 physicians. Contours were compared and analyzed using an expectation-maximization algorithm for simultaneous truth and performance level estimation (STAPLE), and a 95% confidence interval contour was developed. The level of agreement among contours was assessed using a kappa statistic. STAPLE contours underwent full committee editing to generate the final atlas consensus contours. Results: Analysis of the 14 contours showed substantial agreement, with kappa statistics of 0.69 and 0.64 for cases 1 and 2, respectively. There was high specificity for both cases (≥99%) and only moderate sensitivity of 71.3% and 64.9% for cases 1 and 2, respectively. Expert review and discussion generated consensus recommendations for contouring target volumes and treatment for postoperative and locally advanced vulvar cancer. Conclusions: These consensus recommendations for contouring and treatment of vulvar cancer identified areas of complexity and controversy. Given the lack of clinical research evidence in vulvar cancer radiation therapy, the committee advocates a conservative and consistent approach using standardized recommendations.

  5. Consensus Recommendations for Radiation Therapy Contouring and Treatment of Vulvar Carcinoma

    International Nuclear Information System (INIS)

    Gaffney, David K.; King, Bronwyn; Viswanathan, Akila N.; Barkati, Maroie; Beriwal, Sushil; Eifel, Patricia; Erickson, Beth; Fyles, Anthony; Goulart, Jennifer; Harkenrider, Matthew; Jhingran, Anuja; Klopp, Ann; Koh, Wui-Jin; Lim, Karen; Petersen, Ivy; Portelance, Lorraine

    2016-01-01

    Purpose: The purpose of this study was to develop a radiation therapy (RT) contouring atlas and recommendations for women with postoperative and locally advanced vulvar carcinoma. Methods and Materials: An international committee of 35 expert gynecologic radiation oncologists completed a survey of the treatment of vulvar carcinoma. An initial set of recommendations for contouring was discussed and generated by consensus. Two cases, 1 locally advanced and 1 postoperative, were contoured by 14 physicians. Contours were compared and analyzed using an expectation-maximization algorithm for simultaneous truth and performance level estimation (STAPLE), and a 95% confidence interval contour was developed. The level of agreement among contours was assessed using a kappa statistic. STAPLE contours underwent full committee editing to generate the final atlas consensus contours. Results: Analysis of the 14 contours showed substantial agreement, with kappa statistics of 0.69 and 0.64 for cases 1 and 2, respectively. There was high specificity for both cases (≥99%) and only moderate sensitivity of 71.3% and 64.9% for cases 1 and 2, respectively. Expert review and discussion generated consensus recommendations for contouring target volumes and treatment for postoperative and locally advanced vulvar cancer. Conclusions: These consensus recommendations for contouring and treatment of vulvar cancer identified areas of complexity and controversy. Given the lack of clinical research evidence in vulvar cancer radiation therapy, the committee advocates a conservative and consistent approach using standardized recommendations.

  6. Automatic programming of grinding robot restoration of contours

    Directory of Open Access Journals (Sweden)

    Are Willersrud

    1995-07-01

    Full Text Available A new programming method has been developed for grinding robots. Instead of using the conventional jog-and-teach method, the workpiece contour is automatically tracked by the robot. During the tracking, the robot position is stored in the robot control system every 8th millisecond. After filtering and reducing this contour data, a robot program is automatically generated.

  7. Water Technology Lecture 1: Introducing Water Technology

    OpenAIRE

    Gray, Nicholas Frederick

    2017-01-01

    This is a full set of PowerPoint lectures for a course in Water Technology currently given at Trinity College, University of Dublin by professor N.F. Gray. The lectures cover all aspects of water and wastewater treatment and are available for use to lecturers or those interested in the subject. The lecture series is to be used in conjunction with the new textbook ?Water Science and Technology? (4th edition) published by CRC Press in 2017. Lecture 1 is an introduction to the water indust...

  8. Co-ordinated Classroom Lectures.

    Science.gov (United States)

    Harmon, Darell Boyd

    From a series of lectures, a selection of eight are oriented principally toward the biologically developing child, and the physiological operations in visual process. The numbered lectures are--(1) The Coordinated Classroom, its Philosophy and Principles, (2) An Outline of a Biological Point of View, (3) The Evolution of Structure--despite man's…

  9. Semi-automated contour recognition using DICOMautomaton

    International Nuclear Information System (INIS)

    Clark, H; Duzenli, C; Wu, J; Moiseenko, V; Lee, R; Gill, B; Thomas, S

    2014-01-01

    Purpose: A system has been developed which recognizes and classifies Digital Imaging and Communication in Medicine contour data with minimal human intervention. It allows researchers to overcome obstacles which tax analysis and mining systems, including inconsistent naming conventions and differences in data age or resolution. Methods: Lexicographic and geometric analysis is used for recognition. Well-known lexicographic methods implemented include Levenshtein-Damerau, bag-of-characters, Double Metaphone, Soundex, and (word and character)-N-grams. Geometrical implementations include 3D Fourier Descriptors, probability spheres, boolean overlap, simple feature comparison (e.g. eccentricity, volume) and rule-based techniques. Both analyses implement custom, domain-specific modules (e.g. emphasis differentiating left/right organ variants). Contour labels from 60 head and neck patients are used for cross-validation. Results: Mixed-lexicographical methods show an effective improvement in more than 10% of recognition attempts compared with a pure Levenshtein-Damerau approach when withholding 70% of the lexicon. Domain-specific and geometrical techniques further boost performance. Conclusions: DICOMautomaton allows users to recognize contours semi-automatically. As usage increases and the lexicon is filled with additional structures, performance improves, increasing the overall utility of the system.

  10. MAP Estimation of Chin and Cheek Contours in Video Sequences

    Directory of Open Access Journals (Sweden)

    Kampmann Markus

    2004-01-01

    Full Text Available An algorithm for the estimation of chin and cheek contours in video sequences is proposed. This algorithm exploits a priori knowledge about shape and position of chin and cheek contours in images. Exploiting knowledge about the shape, a parametric 2D model representing chin and cheek contours is introduced. Exploiting knowledge about the position, a MAP estimator is developed taking into account the observed luminance gradient as well as a priori probabilities of chin and cheek contours positions. The proposed algorithm was tested with head and shoulder video sequences (image resolution CIF. In nearly 70% of all investigated video frames, a subjectively error free estimation could be achieved. The 2D estimate error is measured as on average between 2.4 and .

  11. Technology assessment of automated atlas based segmentation in prostate bed contouring

    Directory of Open Access Journals (Sweden)

    Sexton Tracy

    2011-09-01

    Full Text Available Abstract Background Prostate bed (PB contouring is time consuming and associated with inter-observer variability. We evaluated an automated atlas-based segmentation (AABS engine in its potential to reduce contouring time and inter-observer variability. Methods An atlas builder (AB manually contoured the prostate bed, rectum, left femoral head (LFH, right femoral head (RFH, bladder, and penile bulb of 75 post-prostatectomy cases to create an atlas according to the recent RTOG guidelines. 5 other Radiation Oncologists (RO and the AABS contoured 5 new cases. A STAPLE contour for each of the 5 patients was generated. All contours were anonymized and sent back to the 5 RO to be edited as clinically necessary. All contouring times were recorded. The dice similarity coefficient (DSC was used to evaluate the unedited- and edited- AABS and inter-observer variability among the RO. Descriptive statistics, paired t-tests and a Pearson correlation were performed. ANOVA analysis using logit transformations of DSC values was calculated to assess inter-observer variability. Results The mean time for manual contours and AABS was 17.5- and 14.1 minutes respectively (p = 0.003. The DSC results (mean, SD for the comparison of the unedited-AABS versus STAPLE contours for the PB (0.48, 0.17, bladder (0.67, 0.19, LFH (0.92, 0.01, RFH (0.92, 0.01, penile bulb (0.33, 0.25 and rectum (0.59, 0.11. The DSC results (mean, SD for the comparison of the edited-AABS versus STAPLE contours for the PB (0.67, 0.19, bladder (0.88, 0.13, LFH (0.93, 0.01, RFH (0.92, 0.01, penile bulb (0.54, 0.21 and rectum (0.78, 0.12. The DSC results (mean, SD for the comparison of the edited-AABS versus the expert panel for the PB (0.47, 0.16, bladder (0.67, 0.18, LFH (0.83, 0.18, RFH (0.83, 0.17, penile bulb (0.31, 0.23 and rectum (0.58, 0.09. The DSC results (mean, SD for the comparison of the STAPLE contours and the 5 RO are PB (0.78, 0.15, bladder (0.96, 0.02, left femoral head (0.87, 0

  12. Automatic Construction by Contour Crafting Technology

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Khorramshahi

    2017-07-01

    Full Text Available Contour Crafting is a novel technology in construction industry based on 3D printing that uses robotics to construct free form building structures by repeatedly laying down layers of material such as concrete. It is actually an approach to scale up automatic fabrication from building small industrial parts to constructing buildings. However, there are little information about contour crafting (CC in current use; present paper aims to describe the operational steps of creating a whole building by the machine reviewing relevant literature. Furthermore, it will represent the advantages of CC usage compared to traditional construction methods, as well as its applicability in construction industry.

  13. Computer assisted holographic moire contouring

    Science.gov (United States)

    Sciammarella, Cesar A.

    2000-01-01

    Theoretical analyses and experimental results on holographic moire contouring on diffusely reflecting objects are presented. The sensitivity and limitations of the method are discussed. Particular emphasis is put on computer-assisted data retrieval, processing, and recording.

  14. Video Lecture Capture Technology Helps Students Study without Affecting Attendance in Large Microbiology Lecture Courses?

    OpenAIRE

    McLean, Jennifer L.; Suchman, Erica L.

    2016-01-01

    Recording lectures using video lecture capture software and making them available for students to watch anytime, from anywhere, has become a common practice in many universities across many disciplines. The software has become increasingly easy to use and is commonly provided and maintained by higher education institutions. Several studies have reported that students use lecture capture to enhance their learning and study for assessments, as well as to catch up on material they miss when they...

  15. Electronic voting to encourage interactive lectures: a randomised trial

    Science.gov (United States)

    2007-01-01

    Background Electronic Voting Systems have been used for education in a variety of disciplines. Outcomes from these studies have been mixed. Because results from these studies have been mixed, we examined whether an EVS system could enhance a lecture's effect on educational outcomes. Methods A cohort of 127 Year 5 medical students at the University of Adelaide was stratified by gender, residency status and academic record then randomised into 2 groups of 64 and 63 students. Each group received consecutive 40-minute lectures on two clinical topics. One group received the EVS for both topics. The other group received traditional teaching only. Evaluation was undertaken with two, 15-question multiple-choice questionnaires (MCQ) assessing knowledge and problem solving and undertaken as a written paper immediately before and after the lectures and repeated online 8–12 weeks later. Standardised institutional student questionnaires were completed for each lecture and independent observers assessed student behaviour during the lectures. Lecturer's opinions were assessed by a questionnaire developed for this study. Results Two-thirds of students randomised to EVS and 59% of students randomised to traditional lectures attended. One-half of the students in the EVS group and 41% in the traditional group completed all questionnaires. There was no difference in MCQ scores between EVS and traditional lectures (p = 0.785). The cervical cancer lectures showed higher student ranking in favour of EVS in all parameters. The breast cancer lectures showed higher ranking in favour of traditional lectures in 5 of 7 parameters (p lecturer-students interactions were increased in the EVS lecture for one lecturer and reduced for the other. Both lecturers felt that the EVS lectures were difficult to prepare, that they were able to keep to time in the traditional lectures, that the educational value of both lecture styles was similar, and that they were neutral-to-slightly favourably disposed

  16. The 1979 Bernard Gregory lectures

    International Nuclear Information System (INIS)

    Weisskopf, V.F.

    1980-02-01

    This volume contains the texts of the lectures given by Professor V.F. Weisskopf at CERN and in Paris in the autumn of 1979, as the first Gregory lecturer. The titles of the three different texts are 'Growing up with Field Theory', 'Recent Trends in Particle Physics' and 'L'Art et la Science'. While the latter lecture was given in French, an English text here follows the French one. The volume starts with a short biographical note about Bernard Gregory. (orig.)

  17. Summer Student Lecture Programme

    CERN Multimedia

    2004-01-01

    Main Auditorium, bldg. 500 DATE TIME LECTURER TITLE Monday 2 August 09:15 - 10:00 P. Wells (CERN) The Higgs Saga at LEP 10:15 - 11:00 G. Cowan (Univ. of London) Introduction to Statistics (2/3) 11:15 - 12:00 G. Cowan (Univ. of London) Introduction to Statistics (3/3) DATE TIME LECTURER TITLE Tuesday 3 August 09:15 - 10:00 P. Sphicas (CERN) Trigger and Data Acquisition Systems (1/2) 10:15 - 11:00 R. Jacobsen (LBLN) From Raw Data to Physics Results (1/2) 11:15 - 12:00 R. Jacobsen (LBLN) G. Cowan (University of London) Discussion Session DATE TIME LECTURER TITLE Wednesday 4 August 09:15 - 10:00 P. Sphicas (CERN) Trigger and Data Acquisition Systems (2/2) 10:15 - 11:00 R. Jacobsen (LBLN) From Raw Data to Physics Results (2/2) 11:15 - 12:00 N. Palanque-Delabrouille (CEA) Astroparticle Physics (1/3) DATE TIME LECTURER TITLE Thursday 5 August 09:15 - 10:00 N. Palanque-Delabrouille (CEA) Astroparticle Physics (2/3) 10:15 - 11:00 N. Palanque-Delabrouille (CEA) A...

  18. SU-E-J-108: Solving the Chinese Postman Problem for Effective Contour Deformation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, J; Zhang, L; Balter, P; Court, L [MD Anderson Cancer Center, Houston, TX (United States); Zhang, Y; Dong, L [Scripps Proton Therapy Center, San Diego, CA (United States)

    2015-06-15

    Purpose: To develop a practical approach for accurate contour deformation when deformable image registration (DIR) is used for atlas-based segmentation or contour propagation in image-guided radiotherapy. Methods: A contour deformation approach was developed on the basis of 3D mesh operations. The 2D contours represented by a series of points in each slice were first converted to a 3D triangular mesh, which was deformed by the deformation vectors resulting from DIR. A set of parallel 2D planes then cut through the deformed 3D mesh, generating unordered points and line segments, which should be reorganized into a set of 2D contour points. It was realized that the reorganization problem was equivalent to solving the Chinese Postman Problem (CPP) by traversing a graph built from the unordered points with the least cost. Alternatively, deformation could be applied to a binary mask converted from the original contours. The deformed binary mask was then converted back into contours at the CT slice locations. We performed a qualitative comparison to validate the mesh-based approach against the image-based approach. Results: The DIR could considerably change the 3D mesh, making complicated 2D contour representations after deformation. CPP was able to effectively reorganize the points in 2D planes no matter how complicated the 2D contours were. The mesh-based approach did not require a post-processing of the contour, thus accurately showing the actual deformation in DIR. The mesh-based approach could keep some fine details and resulted in smoother contours than the image-based approach did, especially for the lung structure. Image-based approach appeared to over-process contours and suffered from image resolution limits. The mesh-based approach was integrated into in-house DIR software for use in routine clinic and research. Conclusion: We developed a practical approach for accurate contour deformation. The efficiency of this approach was demonstrated in both clinic and

  19. Assessment of vocal intensity in lecturers depending on acoustic properties of lecture rooms

    Directory of Open Access Journals (Sweden)

    Witold Mikulski

    2015-08-01

    Full Text Available Background: Lombard’s effect increases the level of vocal intensity in the environment, in which noise occurs. This article presents the results of the author’s own study of vocal intensity level and A-weighted sound pressure level of background noise during normal lectures. The aim of the study was to define whether above-mentioned parameters depend on acoustic properties of rooms (classrooms or lecture rooms and to define how many lectors speak with raised voice. Material and Methods: The study was performed in a group of 50 teachers and lecturers in 10 classrooms with cubature of 160–430 m3 and reverberation time of 0.37–1.3 s (group A consisted of 3 rooms which fulfilled, group B consisted of 3 rooms which almost fulfilled and group C consisted of 4 rooms which did not fulfill criteria based on reverberation time (maximum permissible value is 0.6–0.8 s according to PN-B-02151-4:2015. Criteria of raising voice were based on vocal intensity level (maximum value: 65 dB according to EN ISO 9921:2003. The values of above-mentioned parameters were determined from modes of A-weighted sound pressure level distributions during lectures. Results: Great differentiation of vocal intensity level between lectors was found. In classrooms of group A lectors were not using raised voice, in group B – 21%, and in group C – 60% of lectors were using raised voice. Conclusions: It was observed that acoustic properties of classrooms (defined by reverberation time exert their effect on lecturer’s vocal intensity level (i.e., raising voice, which may contribute to the increased risk of vocal tract illnesses. The occurrence of Lombard’s effect in groups of teachers and lecturers, conducting lectures in rooms, was evidenced. Med Pr 2015;66(4:487–496

  20. Public Lecture: Human Space Exploration

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    Should you wish to attend to this lecture only (and not the full colloquium), please register here: https://indico.cern.ch/event/386996/registration/ Participants to the full colloquium are automatically registered to the public lectures.

  1. ACADEMIC TRAINING LECTURE

    CERN Multimedia

    Academic Training; Tel. 73127

    2001-01-01

    5, 6, 7, 8 and 9 March REGULAR LECTURE PROGRAMME From 11:00 hrs - Main Auditorium bldg. 500 Tracking at the LHC K. Safarik / CERN-EP The lecture will start with a short history of particle tracking in high-energy physics. Then we will concentrate on tracking in the LHC experiments. We will discuss various tracking devices proposed for these experiments, dividing them into two large groups: solid state detectors and gas detectors. Their characteristics, as well as their behaviour in different external conditions (i.e. magnetic field, radiation) will be compared. Furthermore, we will turn to the question: how to design a tracker using these various technologies, what are the essential parameters to be taken into account and we will apply these considerations to the proposed the LHC detectors. The last part of the lecture will be devoted to tracking software. We will mention simulation and concentrate on track finding and reconstruction, reviewing different algorithms prototyped for the LHC experiments. We will ...

  2. USGS Elevation Contours Overlay Map Service from The National Map

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The USGS Elevation Contours service from The National Map (TNM) consists of contours generated for the conterminous United States from 1- and 1/3 arc-second...

  3. Smooth manifolds

    CERN Document Server

    Sinha, Rajnikant

    2014-01-01

    This book offers an introduction to the theory of smooth manifolds, helping students to familiarize themselves with the tools they will need for mathematical research on smooth manifolds and differential geometry. The book primarily focuses on topics concerning differential manifolds, tangent spaces, multivariable differential calculus, topological properties of smooth manifolds, embedded submanifolds, Sard’s theorem and Whitney embedding theorem. It is clearly structured, amply illustrated and includes solved examples for all concepts discussed. Several difficult theorems have been broken into many lemmas and notes (equivalent to sub-lemmas) to enhance the readability of the book. Further, once a concept has been introduced, it reoccurs throughout the book to ensure comprehension. Rank theorem, a vital aspect of smooth manifolds theory, occurs in many manifestations, including rank theorem for Euclidean space and global rank theorem. Though primarily intended for graduate students of mathematics, the book ...

  4. A Neurocomputational Account of the Role of Contour Facilitation in Brightness Perception

    Directory of Open Access Journals (Sweden)

    Dražen eDomijan

    2015-02-01

    Full Text Available A novel filling-in model is proposed in order to account for challenging brightness illusions where inducing background elements are spatially separated from gray target such as dungeon, cube and grating illusion, bull's eye and ring patterns. The model implements simple idea that neural response to low-contrast contour is enhanced (facilitated by the presence of collinear or parallel high-contrast contour in the wider neighborhood. Contour facilitation is achieved via dendritic inhibition which enables computation of maximum function among inputs to the node. Recurrent application of maximum function leads to the propagation of neural signal along collinear or parallel contour segments. When strong global contour signal is accompanied with weak local contour signal at the same location, conditions are met to produce brightness assimilation within filling-in network. Computer simulations showed that the model correctly predicts brightness appearance in all of the above mentioned illusions as well as in White's effect, Benary's cross, Todorović's illusion, checkerboard contrast, contrast-contrast illusion and various variations on the White's effect. The proposed model offer new insights on how geometric factors (contour colinearity or parallelism jointly with contrast magnitude contribute to the brightness perception.

  5. Radiodiagnosis of gastric diseases on the basis of thin contour findings

    International Nuclear Information System (INIS)

    Zubarev, A.V.; Zavodnov, V.Ya.; Sklyanskaya, O.A.

    1988-01-01

    The authors have analyzed the role of the thin contour in radiodiagnisis of various diseases of the gastric mucosa. Altogether 140 patients with various gastric diseases were investigated. Using X-ray examination of the stomach based on the common 2-phase method, thin contour images were obtained in 80 % of the cases. The results of the investigation have revealed direct correlation between the type of the thin contour and a morphological picture of the gastric mucosa in chronic gastritis. Early stomach cancer was characterized by the local absence or rearrangement of a usual pattern of the thin contour on stomach radiograms. It was difficult to defect single erosions or polyps with a diameter under 5 mm against a background of the gastric mucosa thin contour. Good visualization of stomach areolae, particularly those of a rough nodular type in the proximal part of the stomach was suggestive of an ulcerative lesion

  6. A Survey of First-Year Biology Student Opinions Regarding Live Lectures and Recorded Lectures as Learning Tools

    Science.gov (United States)

    Simcock, D. C.; Chua, W. H.; Hekman, M.; Levin, M. T.; Brown, S.

    2017-01-01

    A cohort of first-year biology students was surveyed regarding their opinions and viewing habits for live and recorded lectures. Most respondents (87%) attended live lectures as a rule (attenders), with 66% attending more than two-thirds of the lectures. In contrast, only 52% accessed recordings and only 13% viewed more than two-thirds of the…

  7. Analysis of contour images using optics of spiral beams

    Science.gov (United States)

    Volostnikov, V. G.; Kishkin, S. A.; Kotova, S. P.

    2018-03-01

    An approach is outlined to the recognition of contour images using computer technology based on coherent optics principles. A mathematical description of the recognition process algorithm and the results of numerical modelling are presented. The developed approach to the recognition of contour images using optics of spiral beams is described and justified.

  8. Film documentaire, lecture documentarisante

    Directory of Open Access Journals (Sweden)

    Roger Odin

    2012-06-01

    Full Text Available Réfléchir sur la relation entre le cinéma et la réalité n’est pas, bien sûr, tenter de distinguer l’espace du documentaire de celui de la fiction, au point que l’opposition avec le film de fiction est devenu le critère de définition privilégié du film documentaire. Prenant acte l’existence, dans le espace de la lecture des films, d’une lecture documentaire ou, plus exactement, d’une lecture documentarisante, nous pensons qu’il y a un ensemble de films que s’affiche comme documentaire (tout le problème est précisément étudier comment s’effetue cet affichage.

  9. Are radiography lecturers, leaders?

    International Nuclear Information System (INIS)

    Hendry, Julie Anne

    2013-01-01

    This review article aims to explore the concept of radiography lecturers acting as leaders to their student followers. Through a brief review of the literature, a definition of leadership is suggested and some leadership theories explored. The path-goal theory, leader–member exchange theory and the contemporary theory of transformational leadership are examined more closely. Links between lecturer-leader behaviour and student motivation and learning are tentatively suggested with transformational leadership appearing to offer the optimal leadership style for lecturers to adopt. The paucity of literature relating directly to radiography is acknowledged and areas for further research are suggested. The article concludes with some of the author's practical ideas for incorporating transformational leadership styles and behaviours into radiography education today

  10. Albert Einstein memorial lectures

    CERN Document Server

    Mechoulam, Raphael; The Israel Academy for Sciences and Humanities

    2012-01-01

    This volume consists of a selection of the Albert Einstein Memorial Lectures presented annually at the Israel Academy of Sciences and Humanities. Delivered by eminent scientists and scholars, including Nobel laureates, they cover a broad spectrum of subjects in physics, chemistry, life science, mathematics, historiography and social issues. This distinguished memorial lecture series was inaugurated by the Israel Academy of Sciences and Humanities following an international symposium held in Jerusalem in March 1979 to commemorate the centenary of Albert Einstein's birth. Considering that Einstein's interests, activities and influence were not restricted to theoretical physics but spanned broad fields affecting society and the welfare of humankind, it was felt that these memorial lectures should be addressed to scientists, scholars and erudite laypersons rather than to physicists alone.

  11. What Property of the Contour of a Deforming Region Biases Percepts toward Liquid?

    Directory of Open Access Journals (Sweden)

    Takahiro Kawabe

    2017-06-01

    Full Text Available Human observers can perceive the existence of a transparent surface from dynamic image deformation. They can also easily discriminate a transparent solid material such as plastic and glass from a transparent fluid one such as water and shampoo just by viewing them. However, the image information required for material discrimination of this sort is still unclear. A liquid changes its contour shape non-rigidly. We therefore examined whether additional properties of the contour of a deformation-defined region, which indicated contour non-rigidity, biased percepts of the region toward liquid materials. Our stimuli had a translating circular region wherein a natural texture image was deformed at the spatiotemporal deformation frequency that was optimal for the perception of a transparent layer. In Experiment 1, we dynamically deformed the contour of the circular region and found that large deformation of the contour biased the percept toward liquid. In Experiment 2, we manipulated the blurriness of the contour and observed that a strongly blurred contour biased percepts toward liquid. Taken together, the results suggest that a deforming region lacking a discrete contour biases percepts toward liquid.

  12. Contour junctions defined by dynamic image deformations enhance perceptual transparency.

    Science.gov (United States)

    Kawabe, Takahiro; Nishida, Shin'ya

    2017-11-01

    The majority of work on the perception of transparency has focused on static images with luminance-defined contour junctions, but recent work has shown that dynamic image sequences with dynamic image deformations also provide information about transparency. The present study demonstrates that when part of a static image is dynamically deformed, contour junctions at which deforming and nondeforming contours are connected facilitate the deformation-based perception of a transparent layer. We found that the impression of a transparent layer was stronger when a dynamically deforming area was adjacent to static nondeforming areas than when presented alone. When contour junctions were not formed at the dynamic-static boundaries, however, the impression of a transparent layer was not facilitated by the presence of static surrounding areas. The effect of the deformation-defined junctions was attenuated when the spatial pattern of luminance contrast at the junctions was inconsistent with the perceived transparency related to luminance contrast, while the effect did not change when the spatial luminance pattern was consistent with it. In addition, the results showed that contour completions across the junctions were required for the perception of a transparent layer. These results indicate that deformation-defined junctions that involve contour completion between deforming and nondeforming regions enhance the perception of a transparent layer, and that the deformation-based perceptual transparency can be promoted by the simultaneous presence of appropriately configured luminance and contrast-other features that can also by themselves produce the sensation of perceiving transparency.

  13. Lecturer on tour!

    Science.gov (United States)

    1998-11-01

    Readers may recall the interview with Professor Peter Kalmus which appeared in the July issue of Physics Education and which indicated his latest role of lecturer for the 1998-9 Institute of Physics Schools and Colleges Lecture series. This year's lecture is entitled `Particles and the universe' and the tour was due to begin in St Andrews, Scotland, late in September. Professor Kalmus will be looking at various aspects of particle physics, quantum physics and relativity, and discussing how they reveal the secrets of the beginning of our universe. His own experience of working at CERN, the European centre for particle physics in Switzerland, as well as at other international research facilities will provide a unique insight into activity in one of the most exciting areas of physics. The talks are aimed at the 16-19 age group but members of the public are also welcome to attend. They will act as an opportunity to gain a sneak preview of the dynamic new topics that will soon feature in the A-level syllabus arising from the Institute's 16-19 project. Further details of attendance are available from the local organizers, a list of whom may be obtained from Catherine Wilson in the Education Department at the Institute of Physics, 76 Portland Place, London W1N 3DH (tel: 0171 470 4800, fax: 0171 470 4848). The published schedule (as of September) for the lecture series consists of the following: Dates

  14. Gait Recognition Based on Outermost Contour

    Directory of Open Access Journals (Sweden)

    Lili Liu

    2011-10-01

    Full Text Available Gait recognition aims to identify people by the way they walk. In this paper, a simple but e ective gait recognition method based on Outermost Contour is proposed. For each gait image sequence, an adaptive silhouette extraction algorithm is firstly used to segment the frames of the sequence and a series of postprocessing is applied to obtain the normalized silhouette images with less noise. Then a novel feature extraction method based on Outermost Contour is performed. Principal Component Analysis (PCA is adopted to reduce the dimensionality of the distance signals derived from the Outermost Contours of silhouette images. Then Multiple Discriminant Analysis (MDA is used to optimize the separability of gait features belonging to di erent classes. Nearest Neighbor (NN classifier and Nearest Neighbor classifier with respect to class Exemplars (ENN are used to classify the final feature vectors produced by MDA. In order to verify the e ectiveness and robustness of our feature extraction algorithm, we also use two other classifiers: Backpropagation Neural Network (BPNN and Support Vector Machine (SVM for recognition. Experimental results on a gait database of 100 people show that the accuracy of using MDA, BPNN and SVM can achieve 97.67%, 94.33% and 94.67%, respectively.

  15. Neuronal oscillations form parietal/frontal networks during contour integration.

    Science.gov (United States)

    Castellano, Marta; Plöchl, Michael; Vicente, Raul; Pipa, Gordon

    2014-01-01

    The ability to integrate visual features into a global coherent percept that can be further categorized and manipulated are fundamental abilities of the neural system. While the processing of visual information involves activation of early visual cortices, the recruitment of parietal and frontal cortices has been shown to be crucial for perceptual processes. Yet is it not clear how both cortical and long-range oscillatory activity leads to the integration of visual features into a coherent percept. Here, we will investigate perceptual grouping through the analysis of a contour categorization task, where the local elements that form contour must be linked into a coherent structure, which is then further processed and manipulated to perform the categorization task. The contour formation in our visual stimulus is a dynamic process where, for the first time, visual perception of contours is disentangled from the onset of visual stimulation or from motor preparation, cognitive processes that until now have been behaviorally attached to perceptual processes. Our main finding is that, while local and long-range synchronization at several frequencies seem to be an ongoing phenomena, categorization of a contour could only be predicted through local oscillatory activity within parietal/frontal sources, which in turn, would synchronize at gamma (>30 Hz) frequency. Simultaneously, fronto-parietal beta (13-30 Hz) phase locking forms a network spanning across neural sources that are not category specific. Both long range networks, i.e., the gamma network that is category specific, and the beta network that is not category specific, are functionally distinct but spatially overlapping. Altogether, we show that a critical mechanism underlying contour categorization involves oscillatory activity within parietal/frontal cortices, as well as its synchronization across distal cortical sites.

  16. An Event-Related Potential Examination of Contour Integration Deficits in Schizophrenia

    Directory of Open Access Journals (Sweden)

    Pamela D Butler

    2013-03-01

    Full Text Available Perceptual organization, which refers to the ability to integrate fragments of stimuli to form a representation of a whole edge, part, or object, is impaired in schizophrenia. A contour integration paradigm, involving detection of a set of Gabor patches forming an oval contour pointing to the right or left embedded in a field of randomly oriented Gabors, has been developed for use in clinical trials of schizophrenia. The purpose of the present study was to assess contributions of early and later stages of processing to deficits in contour integration, as well as to develop an event-related potential (ERP analog of this task. Twenty-one patients with schizophrenia and 28 controls participated. The Gabor elements forming the contours were given a low or high degree of orientational jitter, making it either easy or difficult to identify the direction in which the contour was pointing. ERP results showed greater negative peaks at ~165 (N1 component and ~270 ms for the low-jitter versus the high-jitter contours, with a much greater difference between jitter conditions at 270 ms. This later ERP component was previously termed Ncl for closure negativity. Source localization identified the Ncl in the lateral occipital object recognition area. Patients showed a significant decrease in the Ncl, but not N1, compared to controls, and this was associated with impaired behavioral ability to identify contours. In addition, an earlier negative peak was found at ~120 ms (termed N120 that differentiated jitter conditions, had a dorsal stream source, and differed between patients and controls. Patients also showed a deficit in the dorsal stream sensory P1 component. These results are in accord with impairments in distributed circuitry contributing to perceptual organization deficits and provide an ERP analog to the behavioral contour integration task.

  17. Students’ opinions about modern lecture: development path

    Directory of Open Access Journals (Sweden)

    Tatyana A. Astashova

    2017-01-01

    Full Text Available As an objective of the research, the author set the task of identifying students’ opinion and opinion of lecturers about the purpose of the lectures at the university, about the role of the lecturer and preferred form of lectures. As a result of the research, it was necessary to answer the following important questions: What are the objectives of the lecture and the role of the lecturer? Which lectures are more preferable: traditional or interactive? What do lecturers expect from the lecture, do they consider it an advantage or an unnecessary educational activity?The materials were developed for the survey (questionnaire to conduct the research and analyze the results obtained. The students were surveyed before training and after completion of the semester. The study involved 200 students of all areas of Mechanics and Technology Faculty of Novosibirsk State Technical University. Statistical analysis was used for the analysis of the results.As a result, the experiment revealed nonconformity of opinions of students about the purpose of the lecture and the role of a lecturer before the training and after the end of the semester. Lectures, according to students, should help to implement all kinds of practical and independent assignments.Educational standards imply a reduction in the hours of classroom training and an increase in independent work, and the majority of students are not ready (do not want to to study the materials on the topics of discipline completely independently or partially.It revealed a contradiction in opinion, what form of organization of the lecture classes is more interesting to students, which can increase the motivation of the visit and work on the lectures.The technology of designing the educational process in the conditions of the mixed training is proposed, applying the technological map.The technological map is presented in the form of stages of designing the educational process, including recommendations on the use of

  18. Anthropocentric Video Segmentation for Lecture Webcasts

    Directory of Open Access Journals (Sweden)

    Rojas Raul

    2007-01-01

    Full Text Available Abstract Many lecture recording and presentation systems transmit slides or chalkboard content along with a small video of the instructor. As a result, two areas of the screen are competing for the viewer's attention, causing the widely known split-attention effect. Face and body gestures, such as pointing, do not appear in the context of the slides or the board. To eliminate this problem, this article proposes to extract the lecturer from the video stream and paste his or her image onto the board or slide image. As a result, the lecturer acting in front of the board or slides becomes the center of attention. The entire lecture presentation becomes more human-centered. This article presents both an analysis of the underlying psychological problems and an explanation of signal processing techniques that are applied in a concrete system. The presented algorithm is able to extract and overlay the lecturer online and in real time at full video resolution.

  19. Anthropocentric Video Segmentation for Lecture Webcasts

    Directory of Open Access Journals (Sweden)

    Raul Rojas

    2008-03-01

    Full Text Available Many lecture recording and presentation systems transmit slides or chalkboard content along with a small video of the instructor. As a result, two areas of the screen are competing for the viewer's attention, causing the widely known split-attention effect. Face and body gestures, such as pointing, do not appear in the context of the slides or the board. To eliminate this problem, this article proposes to extract the lecturer from the video stream and paste his or her image onto the board or slide image. As a result, the lecturer acting in front of the board or slides becomes the center of attention. The entire lecture presentation becomes more human-centered. This article presents both an analysis of the underlying psychological problems and an explanation of signal processing techniques that are applied in a concrete system. The presented algorithm is able to extract and overlay the lecturer online and in real time at full video resolution.

  20. Time contour expression of limited range phenomena on stack chart; Jugo chart jo deno kyokuchi gensho jikan contour

    Energy Technology Data Exchange (ETDEWEB)

    Kametani, T

    1997-05-27

    Time contour expression of limited range phenomena on stack chart is examined for further improvement on the result of the ultimate interpretation in the seismic reflection survey. The policy is made clear from the beginning that local phenomena are to be discussed, and data prior CMP stacking is interpreted in detail. For this purpose, it is effective to make use of the time contour expression in the midpoint-offset plane simultaneously with the CMP and COP panels. For the review of data prior to CMP stacking, it is convenient to use the CMP (CDP) stacking chart in which the data is arranged methodically. In this chart, all the channels which are crude data prior to stacking are plotted on midpoint-offset coordinates, which plane is called the MOD (Midpoint Offset Domain) panel. Various panels can be chosen unrestrictedly, and their mutual relations can be easily grasped. When data points are given a time axis, they can be expressed in a time contour. Studies are conducted about the underground structure, multiple reflection paths divided by it, and characteristics of detour reflection attributable to faults. 4 refs., 9 figs.

  1. Three lectures on Newton's laws

    OpenAIRE

    Kokarev, Sergey S.

    2009-01-01

    Three small lectures are devoted to three Newton's laws, lying in the foundation of classical mechanics. These laws are analyzed from the viewpoint of our contemporary knowledge about space, time and physical interactions. The lectures were delivered for students of YarGU in RSEC "Logos".

  2. The Effect of Contouring Variability on Dosimetric Parameters for Brain Metastases Treated With Stereotactic Radiosurgery

    International Nuclear Information System (INIS)

    Stanley, Julia; Dunscombe, Peter; Lau, Harold; Burns, Paul; Lim, Gerald; Liu, Hong-Wei; Nordal, Robert; Starreveld, Yves; Valev, Boris; Voroney, Jon-Paul; Spencer, David P.

    2013-01-01

    Purpose: To quantify the effect of contouring variation on stereotactic radiosurgery plan quality metrics for brain metastases. Methods and Materials: Fourteen metastases, each contoured by 8 physicians, formed the basis of this study. A template-based dynamic conformal 5-arc dose distribution was developed for each of the 112 contours, and each dose distribution was applied to the 7 other contours in each patient set. Radiation Therapy Oncology Group (RTOG) plan quality metrics and the Paddick conformity index were calculated for each of the 896 combinations of dose distributions and contours. Results: The ratio of largest to smallest contour volume for each metastasis varied from 1.25 to 4.47, with a median value of 1.68 (n=8). The median absolute difference in RTOG conformity index between the value for the reference contour and the values for the alternative contours was 0.35. The variation of the range of conformity index for all contours for a given tumor varied with the tumor size. Conclusions: The high degree of interobserver contouring variation strongly suggests that peer review or consultation should be adopted to standardize tumor volume prescription. Observer confidence was not reflected in contouring consistency. The impact of contouring variability on plan quality metrics, used as criteria for clinical trial protocol compliance, was such that the category of compliance was robust to interobserver effects only 70% of the time

  3. Envisioning the Transformative Role of IT in Lectures

    Directory of Open Access Journals (Sweden)

    Telmo Zarraonandia

    2013-02-01

    Full Text Available One of the most widely used methods for teaching is the lecture. During the last few decades lecturers and students have taken advantage of the progressive introduction of new technology for supporting these lectures. As this trend is very likely to continue, in this paper we will try to anticipate some possible technology enriched future lecture scenarios. We also present ALFs, a system which aims to improve the communication between participants in a lecture making use of augmented reality techniques.

  4. Towards Stabilizing Parametric Active Contours

    DEFF Research Database (Denmark)

    Liu, Jinchao; Fan, Zhun; Olsen, Søren Ingvor

    2014-01-01

    Numerical instability often occurs in evolving of parametric active contours. This is mainly due to the undesired change of parametrization during evolution. In this paper, we propose a new tangential diffusion term to compensate this undesired change. As a result, the parametrization will converge...

  5. Diversity dynamics operating between students lecturers and management in a historically Black university: The lecturers perspective

    Directory of Open Access Journals (Sweden)

    Michelle S. May

    2012-03-01

    Research purpose: The purpose of the research was to describe the experiences of nine lecturers in a particular HBU. This was undertaken to analyse and interpret the conscious and unconscious diversity dynamics operating in the relationship between the students, lecturers and management, from the lecturers’ perspective. Motivation for the study: The researcher was interested in the nature of the diversity dynamics operating in the relationship between students, lecturers and management in an HBU, as a platform towards understanding diversity dynamics in educational institutions and South African organisations. Research design, approach and method: Qualitative and descriptive research approaches were used. Hermeneutic phenomenology, using the systems psychodynamic perspective, allowed for the description and interpretation of diversity dynamics operating in the relationship between the students, lecturers and management. The data were obtained through in-depth interviews with nine lecturers. Thematic analysis resulted in two broad themes for which a discussion was provided and a research hypothesis formulated. Main findings: Two broad themes manifested, firstly diversity characteristics and secondly struggle skills entrenching the Black and White divide. Practical/managerial implications: The research highlighted the importance of understanding the diversity dynamics operating in the relationship between students, lecturers and management. This was in order to develop our understanding of diversity dynamics operating in educational institutions specifically, and organisations in general. Contribution/value-add: The understanding about diversity dynamics is available for application, by lecturers and management, to form a different understanding of conscious and unconscious factors impacting on the relationship between the three stakeholders, and subsequently the effectiveness of the three stakeholders in their respective roles. This understanding can also be

  6. Smooth polyhedral surfaces

    KAUST Repository

    Gü nther, Felix; Jiang, Caigui; Pottmann, Helmut

    2017-01-01

    Polyhedral surfaces are fundamental objects in architectural geometry and industrial design. Whereas closeness of a given mesh to a smooth reference surface and its suitability for numerical simulations were already studied extensively, the aim of our work is to find and to discuss suitable assessments of smoothness of polyhedral surfaces that only take the geometry of the polyhedral surface itself into account. Motivated by analogies to classical differential geometry, we propose a theory of smoothness of polyhedral surfaces including suitable notions of normal vectors, tangent planes, asymptotic directions, and parabolic curves that are invariant under projective transformations. It is remarkable that seemingly mild conditions significantly limit the shapes of faces of a smooth polyhedral surface. Besides being of theoretical interest, we believe that smoothness of polyhedral surfaces is of interest in the architectural context, where vertices and edges of polyhedral surfaces are highly visible.

  7. Smooth polyhedral surfaces

    KAUST Repository

    Günther, Felix

    2017-03-15

    Polyhedral surfaces are fundamental objects in architectural geometry and industrial design. Whereas closeness of a given mesh to a smooth reference surface and its suitability for numerical simulations were already studied extensively, the aim of our work is to find and to discuss suitable assessments of smoothness of polyhedral surfaces that only take the geometry of the polyhedral surface itself into account. Motivated by analogies to classical differential geometry, we propose a theory of smoothness of polyhedral surfaces including suitable notions of normal vectors, tangent planes, asymptotic directions, and parabolic curves that are invariant under projective transformations. It is remarkable that seemingly mild conditions significantly limit the shapes of faces of a smooth polyhedral surface. Besides being of theoretical interest, we believe that smoothness of polyhedral surfaces is of interest in the architectural context, where vertices and edges of polyhedral surfaces are highly visible.

  8. Automatic liver contouring for radiotherapy treatment planning

    International Nuclear Information System (INIS)

    Li, Dengwang; Kapp, Daniel S; Xing, Lei; Liu, Li

    2015-01-01

    To develop automatic and efficient liver contouring software for planning 3D-CT and four-dimensional computed tomography (4D-CT) for application in clinical radiation therapy treatment planning systems.The algorithm comprises three steps for overcoming the challenge of similar intensities between the liver region and its surrounding tissues. First, the total variation model with the L1 norm (TV-L1), which has the characteristic of multi-scale decomposition and an edge-preserving property, is used for removing the surrounding muscles and tissues. Second, an improved level set model that contains both global and local energy functions is utilized to extract liver contour information sequentially. In the global energy function, the local correlation coefficient (LCC) is constructed based on the gray level co-occurrence matrix both of the initial liver region and the background region. The LCC can calculate the correlation of a pixel with the foreground and background regions, respectively. The LCC is combined with intensity distribution models to classify pixels during the evolutionary process of the level set based method. The obtained liver contour is used as the candidate liver region for the following step. In the third step, voxel-based texture characterization is employed for refining the liver region and obtaining the final liver contours.The proposed method was validated based on the planning CT images of a group of 25 patients undergoing radiation therapy treatment planning. These included ten lung cancer patients with normal appearing livers and ten patients with hepatocellular carcinoma or liver metastases. The method was also tested on abdominal 4D-CT images of a group of five patients with hepatocellular carcinoma or liver metastases. The false positive volume percentage, the false negative volume percentage, and the dice similarity coefficient between liver contours obtained by a developed algorithm and a current standard delineated by the expert group

  9. Argonne lectures on particles accelerator magnets

    International Nuclear Information System (INIS)

    Devred, A.

    1999-09-01

    The quest for elementary particles has promoted the development of particle accelerators producing beams of increasingly higher energies. In a synchrotron, the particle energy is directly proportional to the product of the machine's radius times the bending magnets' field strength. Present proton experiments at the TeV scale require facilities with circumferences ranging from a few to tens of kilometers and relying on a large number (several hundred to several thousand) high field dipole magnets and high field gradient quadrupole magnets. These electro-magnets use high-current-density, low-critical-temperature superconducting cables and are cooled down at liquid helium temperature. They are among the most costly and the most challenging components of the machine. After explaining what are the various types of accelerator magnets and why they are needed (lecture 1), we briefly recall the origins of superconductivity and we review the parameters of existing superconducting particle accelerators (lecture 2). Then, we review the superconducting materials that are available at industrial scale (chiefly, NbTi and Nb 3 Sn) and we explain in details the manufacturing of NbTi wires and cables (lecture 3). We also present the difficulties of processing and insulating Nb 3 Sn conductors, which so far have limited the use of this material in spite of its superior performances. We continue by discussing the two dimensional current distributions which are the most appropriate for generating pure dipole and quadrupole fields and we explain how these ideal distributions can be approximated by so called cosθ and cos 2θ coil designs (lecture 4). We also present a few alternative designs which are being investigated and we describe the difficulties of realizing coil ends. Next, we present the mechanical design concepts that are used in existing accelerator magnets (lecture 5) and we describe how the magnets are assembled (lecture 6). Some of the toughest requirements on the

  10. Argonne lectures on particles accelerator magnets

    Energy Technology Data Exchange (ETDEWEB)

    Devred, A

    1999-09-01

    The quest for elementary particles has promoted the development of particle accelerators producing beams of increasingly higher energies. In a synchrotron, the particle energy is directly proportional to the product of the machine's radius times the bending magnets' field strength. Present proton experiments at the TeV scale require facilities with circumferences ranging from a few to tens of kilometers and relying on a large number (several hundred to several thousand) high field dipole magnets and high field gradient quadrupole magnets. These electro-magnets use high-current-density, low-critical-temperature superconducting cables and are cooled down at liquid helium temperature. They are among the most costly and the most challenging components of the machine. After explaining what are the various types of accelerator magnets and why they are needed (lecture 1), we briefly recall the origins of superconductivity and we review the parameters of existing superconducting particle accelerators (lecture 2). Then, we review the superconducting materials that are available at industrial scale (chiefly, NbTi and Nb{sub 3}Sn) and we explain in details the manufacturing of NbTi wires and cables (lecture 3). We also present the difficulties of processing and insulating Nb{sub 3}Sn conductors, which so far have limited the use of this material in spite of its superior performances. We continue by discussing the two dimensional current distributions which are the most appropriate for generating pure dipole and quadrupole fields and we explain how these ideal distributions can be approximated by so called cos{theta} and cos 2{theta} coil designs (lecture 4). We also present a few alternative designs which are being investigated and we describe the difficulties of realizing coil ends. Next, we present the mechanical design concepts that are used in existing accelerator magnets (lecture 5) and we describe how the magnets are assembled (lecture 6). Some of the toughest

  11. SmoothMoves : Smooth pursuits head movements for augmented reality

    NARCIS (Netherlands)

    Esteves, Augusto; Verweij, David; Suraiya, Liza; Islam, Rasel; Lee, Youryang; Oakley, Ian

    2017-01-01

    SmoothMoves is an interaction technique for augmented reality (AR) based on smooth pursuits head movements. It works by computing correlations between the movements of on-screen targets and the user's head while tracking those targets. The paper presents three studies. The first suggests that head

  12. Video Lecture Capture Technology Helps Students Study without Affecting Attendance in Large Microbiology Lecture Courses

    Directory of Open Access Journals (Sweden)

    Jennifer Lynn McLean

    2016-12-01

    Full Text Available Recording lectures using video lecture capture software and making them available for students to watch anytime, from anywhere, has become a common practice in many universities across many disciplines. The software has become increasingly easy to use and is commonly provided and maintained by higher education institutions. Several studies have reported that students use lecture capture to enhance their learning and study for assessments, as well as to catch up on material they miss when they cannot attend class due to extenuating circumstances. Furthermore, students with disabilities and students from non-English Speaking Backgrounds (NESB may benefit from being able to watch the video lecture captures at their own pace. Yet, the effect of this technology on class attendance remains a controversial topic and largely unexplored in undergraduate microbiology education. Here, we show that when video lecture captures were available in our large enrollment general microbiology courses, attendance did not decrease. In fact, the majority of students reported that having the videos available did not encourage them to skip class, but rather they used them as a study tool. When we surveyed NESB students and nontraditional students about their attitudes toward this technology, they found it helpful for their learning and for keeping up with the material.

  13. Design of a Vibrotactile Vest for Contour Perception

    Directory of Open Access Journals (Sweden)

    Juan Wu

    2012-11-01

    Full Text Available A vibrotactile array is a promising human computer interface which could display graphical information to users in a tactile form. This paper presents the design and testing of an image contour display system with a vibrotactile array. The tactile image display system is attached to the back of the user. It converts visual graphics into 2D tactile images and allows subjects to feel the contours of objects through vibration stimulus. The system consists of a USB camera, 48 (6×8 vibrating motors and an embedded control system. The image is captured by the camera and the 2D contour is extracted and transformed into vibrotactile stimuli using a temporal-spatial dynamic coding method. Preliminary experiments were carried out and the optimal parameters of the vibrating time and duration were explored. To evaluate the feasibility and robustness of this vibration mode, letters were also tactilely displayed and the recognition rate about the alphabet letter display was investigated. It was shown that under the condition of no pre-training for the subjects, the recognition rate was 82%. Such a recognition rate is higher than that of the scanning mode (47.5% and the improved handwriting mode (76.8%. The results indicated that the proposed method was efficient in conveying the contour information to the visually impaired by means of vibrations.

  14. Smoothing a Piecewise-Smooth: An Example from Plankton Population Dynamics

    DEFF Research Database (Denmark)

    Piltz, Sofia Helena

    2016-01-01

    In this work we discuss a piecewise-smooth dynamical system inspired by plankton observations and constructed for one predator switching its diet between two different types of prey. We then discuss two smooth formulations of the piecewise-smooth model obtained by using a hyperbolic tangent funct...... function and adding a dimension to the system. We compare model behaviour of the three systems and show an example case where the steepness of the switch is determined from a comparison with data on freshwater plankton....

  15. Female Facial Attractiveness Assessed from Three-Dimensional Contour Lines by University Students

    Directory of Open Access Journals (Sweden)

    Jinwara Jirathamopas

    2018-05-01

    Full Text Available Background: Three-dimensional (3D images could provide more accurate evaluation for facial attractiveness than two-dimensional (2D images. The 3D facial image could be simplified into gray scale 3D contour lines. Whether female facial attractiveness could be perceived in these simplified 3D facial contour lines should be determined. Methods: A series of 100 2D photographs (one frontal and two lateral views and 3D contour lines extracted from 3D facial images of females were projected onto a screen. Each image presentation lasted 5 s, and the evaluators marked their impression of each image’s facial attractiveness on a five-point Likert scale within 3 s of its presentation. The evaluation of the 3D contour lines was performed twice, 2 weeks apart. The evaluators were university students. Results: High consistency (r = 0.92 was found for the first and second evaluation of 3D facial contour lines for female facial attractiveness. The judgments of unattractive face were more consistent than the judgments of attractive face. Male students tended to give lower scores than female students in the evaluation of female facial attractiveness. Conclusions: Female facial attractiveness could be evaluated by 3D facial contour lines. 3D facial contour lines should be one of the key factors of facial attractiveness.

  16. Peripheral Contour Grouping and Saccade Targeting: The Role of Mirror Symmetry

    Directory of Open Access Journals (Sweden)

    Michaël Sassi

    2014-01-01

    Full Text Available Integrating shape contours in the visual periphery is vital to our ability to locate objects and thus make targeted saccadic eye movements to efficiently explore our surroundings. We tested whether global shape symmetry facilitates peripheral contour integration and saccade targeting in three experiments, in which observers responded to a successful peripheral contour detection by making a saccade towards the target shape. The target contours were horizontally (Experiment 1 or vertically (Experiments 2 and 3 mirror symmetric. Observers responded by making a horizontal (Experiments 1 and 2 or vertical (Experiment 3 eye movement. Based on an analysis of the saccadic latency and accuracy, we conclude that the figure-ground cue of global mirror symmetry in the periphery has little effect on contour integration or on the speed and precision with which saccades are targeted towards objects. The role of mirror symmetry may be more apparent under natural viewing conditions with multiple objects competing for attention, where symmetric regions in the visual field can pre-attentively signal the presence of objects, and thus attract eye movements.

  17. ACADEMIC TRAINING LECTURE

    CERN Multimedia

    Academic Training; Tel. 73127

    2001-01-01

    26, 27, 28 February and 1, 2 March REGULAR LECTURE PROGRAMME From 11:00 hrs - Main Auditorium bldg. 500 Recent Results on CP Violation and B Physics P.F. HARRISON / QMW, London, UK With the advent of the asymmetric B factories in Japan and the US, exciting new results on CP Violation and B Physics are starting to be achieved. In these lectures, we review the existing experimental and phenomenological context of these measurements, we compare and contrast the new experimental facilities and discuss the implications of the recent results on our understanding. Finally we summarise the prospects for future developments.

  18. Effectiveness of mesotherapy on body contouring.

    Science.gov (United States)

    Park, Seung Ha; Kim, Deok Woo; Lee, Min Ah; Yoo, Sang Chul; Rhee, Seung Chul; Koo, Sang Hwan; Seol, Geun Hye; Cho, Eun Young

    2008-04-01

    Despite the increasing interest in mesotherapy as an alternative method for body contouring, there are few reports of its safety, efficacy, and mechanism of action. A clinical examination was performed to evaluate the efficacy of mesotherapy for body contouring. Twenty women were enrolled in this prospective, case-controlled study over a 12-week period. The authors injected a mixed solution (i.e., aminophylline, buflomedil, and lidocaine) into the superficial dermis of the medial aspect of one thigh weekly using a mechanical delivery gun. There was no treatment to the other thigh. The change in the fat level was evaluated by measuring the girth of the thighs and by computed tomographic scanning. The lipid profiles were checked to determine the effect of mesotherapy on lipid metabolism, and questionnaires were used to determine the satisfaction rate of the patients. The loss of thigh girth on the treated side was not significantly different from that of the untreated side. The computed tomographic scans showed no statistically significant difference in the cross-sectional area or thickness of the fat layer between each group. There were no statistically significant changes in the lipid profiles except for the triglyceride level. A questionnaire asking about the effect of mesotherapy indicated poor patient satisfaction. Mesotherapy is not an effective alternative treatment modality for body contouring.

  19. Lectures for CERN pensioners

    CERN Multimedia

    GS Department

    2009-01-01

    The CERN Medical Service and the Pensioners Association are pleased to invite CERN pensioners to a series of lectures given by professors and specialists from the Teaching Hospitals and the Faculty of Medicine of the University of Geneva on the following topic: PROMOTION OF OPTIMUM BRAIN AGEING The lectures will take place in the Main CERN Auditorium (Building 60) from 2.30 p.m. to 4.30 p.m. on the following dates: Thursday 15 January 2009: Diagnosing and treating Alzheimer’s disease Pr Gabriel GOLD Wednesday 25 February 2009: What is the brain reserve? Speaker’s name to be announced at a later date. The lectures will be given in French, with transparencies in English, and will be followed by a wide-ranging debate with the participants. CERN Medical Service - Pensioners Association - CERN-ESO (GAC-EPA)

  20. Automatic Image Segmentation Using Active Contours with Univariate Marginal Distribution

    Directory of Open Access Journals (Sweden)

    I. Cruz-Aceves

    2013-01-01

    Full Text Available This paper presents a novel automatic image segmentation method based on the theory of active contour models and estimation of distribution algorithms. The proposed method uses the univariate marginal distribution model to infer statistical dependencies between the control points on different active contours. These contours have been generated through an alignment process of reference shape priors, in order to increase the exploration and exploitation capabilities regarding different interactive segmentation techniques. This proposed method is applied in the segmentation of the hollow core in microscopic images of photonic crystal fibers and it is also used to segment the human heart and ventricular areas from datasets of computed tomography and magnetic resonance images, respectively. Moreover, to evaluate the performance of the medical image segmentations compared to regions outlined by experts, a set of similarity measures has been adopted. The experimental results suggest that the proposed image segmentation method outperforms the traditional active contour model and the interactive Tseng method in terms of segmentation accuracy and stability.

  1. Differential contribution of early visual areas to the perceptual process of contour processing.

    Science.gov (United States)

    Schira, Mark M; Fahle, Manfred; Donner, Tobias H; Kraft, Antje; Brandt, Stephan A

    2004-04-01

    We investigated contour processing and figure-ground detection within human retinotopic areas using event-related functional magnetic resonance imaging (fMRI) in 6 healthy and naïve subjects. A figure (6 degrees side length) was created by a 2nd-order texture contour. An independent and demanding foveal letter-discrimination task prevented subjects from noticing this more peripheral contour stimulus. The contour subdivided our stimulus into a figure and a ground. Using localizers and retinotopic mapping stimuli we were able to subdivide each early visual area into 3 eccentricity regions corresponding to 1) the central figure, 2) the area along the contour, and 3) the background. In these subregions we investigated the hemodynamic responses to our stimuli and compared responses with or without the contour defining the figure. No contour-related blood oxygenation level-dependent modulation in early visual areas V1, V3, VP, and MT+ was found. Significant signal modulation in the contour subregions of V2v, V2d, V3a, and LO occurred. This activation pattern was different from comparable studies, which might be attributable to the letter-discrimination task reducing confounding attentional modulation. In V3a, but not in any other retinotopic area, signal modulation corresponding to the central figure could be detected. Such contextual modulation will be discussed in light of the recurrent processing hypothesis and the role of visual awareness.

  2. Impact of region contouring variability on image-based focal therapy evaluation

    Science.gov (United States)

    Gibson, Eli; Donaldson, Ian A.; Shah, Taimur T.; Hu, Yipeng; Ahmed, Hashim U.; Barratt, Dean C.

    2016-03-01

    Motivation: Focal therapy is an emerging low-morbidity treatment option for low-intermediate risk prostate cancer; however, challenges remain in accurately delivering treatment to specified targets and determining treatment success. Registered multi-parametric magnetic resonance imaging (MPMRI) acquired before and after treatment can support focal therapy evaluation and optimization; however, contouring variability, when defining the prostate, the clinical target volume (CTV) and the ablation region in images, reduces the precision of quantitative image-based focal therapy evaluation metrics. To inform the interpretation and clarify the limitations of such metrics, we investigated inter-observer contouring variability and its impact on four metrics. Methods: Pre-therapy and 2-week-post-therapy standard-of-care MPMRI were acquired from 5 focal cryotherapy patients. Two clinicians independently contoured, on each slice, the prostate (pre- and post-treatment) and the dominant index lesion CTV (pre-treatment) in the T2-weighted MRI, and the ablated region (post-treatment) in the dynamic-contrast- enhanced MRI. For each combination of clinician contours, post-treatment images were registered to pre-treatment images using a 3D biomechanical-model-based registration of prostate surfaces, and four metrics were computed: the proportion of the target tissue region that was ablated and the target:ablated region volume ratio for each of two targets (the CTV and an expanded planning target volume). Variance components analysis was used to measure the contribution of each type of contour to the variance in the therapy evaluation metrics. Conclusions: 14-23% of evaluation metric variance was attributable to contouring variability (including 6-12% from ablation region contouring); reducing this variability could improve the precision of focal therapy evaluation metrics.

  3. Adaptive Pseudo Dilation for Gestalt Edge Grouping and Contour Detection

    NARCIS (Netherlands)

    Papari, Giuseppe; Petkov, Nicolai

    2008-01-01

    We consider the problem of detecting object contours in natural images. In many cases, local luminance changes turn out to be stronger in textured areas than on object contours. Therefore, local edge features, which only look at a small neighborhood of each pixel, cannot be reliable indicators of

  4. Feynman Lectures on Gravitation

    International Nuclear Information System (INIS)

    Borcherds, P

    2003-01-01

    In the early 1960s Feynman lectured to physics undergraduates and, with the assistance of his colleagues Leighton and Sands, produced the three-volume classic Feynman Lectures in Physics. These lectures were delivered in the mornings. In the afternoons Feynman was giving postgraduate lectures on gravitation. This book is based on notes compiled by two students on that course: Morinigo and Wagner. Their notes were checked and approved by Feynman and were available at Caltech. They have now been edited by Brian Hatfield and made more widely available. The book has a substantial preface by John Preskill and Kip Thorne, and an introduction entitled 'Quantum Gravity' by Brian Hatfield. You should read these before going on to the lectures themselves. Preskill and Thorne identify three categories of potential readers of this book. 1. Those with a postgraduate training in theoretical physics. 2. 'Readers with a solid undergraduate training in physics'. 3. 'Admirers of Feynman who do not have a strong physics background'. The title of the book is perhaps misleading: readers in category 2 who think that this book is an extension of the Feynman Lectures in Physics may be disappointed. It is not: it is a book aimed mainly at those in category 1. If you want to get to grips with gravitation (and general relativity) then you need to read an introductory text first e.g. General Relativity by I R Kenyon (Oxford: Oxford University Press) or A Unified Grand Tour of Theoretical Physics by Ian D Lawrie (Bristol: IoP). But there is no Royal Road. As pointed out in the preface and in the introduction, the book represents Feynman's thinking about gravitation some 40 years ago: the lecture course was part of his attempts to understand the subject himself, and for readers in all three categories it is this that makes the book one of interest: the opportunity to observe how a great physicist attempts to tackle some of the hardest challenges of physics. However, the book was written 40

  5. Measurement of laser welding pool geometry using a closed convex active contour model

    International Nuclear Information System (INIS)

    Zheng, Rui; Zhang, Pu; Duan, Aiqing; Xiao, Peng

    2014-01-01

    The purpose of this study was to develop a computer vision method to measure geometric parameters of the weld pool in a deep penetration CO 2 laser welding system. Accurate measurement was achieved by removing a huge amount of interference caused by spatter, arc light and plasma to extract the true weld pool contour. This paper introduces a closed convex active contour (CCAC) model derived from the active contour model (snake model), which is a more robust high-level vision method than the traditional low-level vision methods. We made an improvement by integrating an active contour with the information that the weld pool contour is almost a closed convex curve. An effective thresholding method and an improved greedy algorithm are also given to complement the CCAC model. These influences can be effectively removed by using the CCAC model to acquire and measure the weld pool contour accurately and relatively fast. (paper)

  6. Electronic voting to encourage interactive lectures: a randomised trial

    Directory of Open Access Journals (Sweden)

    Palmer Edward

    2007-07-01

    Full Text Available Abstract Background Electronic Voting Systems have been used for education in a variety of disciplines. Outcomes from these studies have been mixed. Because results from these studies have been mixed, we examined whether an EVS system could enhance a lecture's effect on educational outcomes. Methods A cohort of 127 Year 5 medical students at the University of Adelaide was stratified by gender, residency status and academic record then randomised into 2 groups of 64 and 63 students. Each group received consecutive 40-minute lectures on two clinical topics. One group received the EVS for both topics. The other group received traditional teaching only. Evaluation was undertaken with two, 15-question multiple-choice questionnaires (MCQ assessing knowledge and problem solving and undertaken as a written paper immediately before and after the lectures and repeated online 8–12 weeks later. Standardised institutional student questionnaires were completed for each lecture and independent observers assessed student behaviour during the lectures. Lecturer's opinions were assessed by a questionnaire developed for this study. Results Two-thirds of students randomised to EVS and 59% of students randomised to traditional lectures attended. One-half of the students in the EVS group and 41% in the traditional group completed all questionnaires. There was no difference in MCQ scores between EVS and traditional lectures (p = 0.785. The cervical cancer lectures showed higher student ranking in favour of EVS in all parameters. The breast cancer lectures showed higher ranking in favour of traditional lectures in 5 of 7 parameters (p Conclusion In this setting, EVS technology used in large group lectures did not offer significant advantages over the more traditional lecture format.

  7. Assessment and improvement of radiation oncology trainee contouring ability utilizing consensus-based penalty metrics

    International Nuclear Information System (INIS)

    Hallock, Abhirami; Read, Nancy; D'Souza, David

    2012-01-01

    The objective of this study was to develop and assess the feasibility of utilizing consensus-based penalty metrics for the purpose of critical structure and organ at risk (OAR) contouring quality assurance and improvement. A Delphi study was conducted to obtain consensus on contouring penalty metrics to assess trainee-generated OAR contours. Voxel-based penalty metric equations were used to score regions of discordance between trainee and expert contour sets. The utility of these penalty metric scores for objective feedback on contouring quality was assessed by using cases prepared for weekly radiation oncology radiation oncology trainee treatment planning rounds. In two Delphi rounds, six radiation oncology specialists reached agreement on clinical importance/impact and organ radiosensitivity as the two primary criteria for the creation of the Critical Structure Inter-comparison of Segmentation (CriSIS) penalty functions. Linear/quadratic penalty scoring functions (for over- and under-contouring) with one of four levels of severity (none, low, moderate and high) were assigned for each of 20 OARs in order to generate a CriSIS score when new OAR contours are compared with reference/expert standards. Six cases (central nervous system, head and neck, gastrointestinal, genitourinary, gynaecological and thoracic) then were used to validate 18 OAR metrics through comparison of trainee and expert contour sets using the consensus derived CriSIS functions. For 14 OARs, there was an improvement in CriSIS score post-educational intervention. The use of consensus-based contouring penalty metrics to provide quantitative information for contouring improvement is feasible.

  8. VT Data - Lidar 1ft Contours

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) This metadata applies to contours derived from Quality Level 2 (QL2) Lidar 'collections' with a resolution (RESCLASS) of 0.7m. For an overview of...

  9. 47 CFR 73.6010 - Class A TV station protected contour.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Class A TV station protected contour. 73.6010... RADIO BROADCAST SERVICES Class A Television Broadcast Stations § 73.6010 Class A TV station protected contour. (a) A Class A TV station will be protected from interference within the following predicted...

  10. What is in a contour map? A region-based logical formalization of contour semantics

    Science.gov (United States)

    Usery, E. Lynn; Hahmann, Torsten

    2015-01-01

    Contours maps (such as topographic maps) compress the information of a function over a two-dimensional area into a discrete set of closed lines that connect points of equal value (isolines), striking a fine balance between expressiveness and cognitive simplicity. They allow humans to perform many common sense reasoning tasks about the underlying function (e.g. elevation).

  11. From Inpainting to Active Contours

    DEFF Research Database (Denmark)

    Lauze, Francois Bernard; Nielsen, Mads

    2008-01-01

    state equation). The contour evolution is implemented in the framework of level sets. Finally, the proposed method is validated on various examples. We focus among others in the segmentation of calcified plaques observed in radiographs from human lumbar aortic regions. Keywords  Segmentation - Inpainting - Active...

  12. Solution of the diffusion equation (2 dimensions, several media, arbitrary boundary); Resolution de l'equation de diffusion (deux dimensions, plusieurs regions, contours quelconques)

    Energy Technology Data Exchange (ETDEWEB)

    Nuyen, Luong Than [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-05-15

    Quite often practical problems involve relatively complicated geometrical shapes and several very different media. The discretization technique used here (variable mesh spacings) has the following advantages: it enables one to approximate curved contours more easily, to distribute the mesh points more economically and to smooth out discontinuities due to two very different media (danger of poor convergence). The method of programming by subroutines makes available to engineers and scientists who are not well acquainted with numerical analysis, a simple and foolproof iterative method: it suffices to pass by all the mesh points and to call the corresponding subroutine each time. (author) [French] Un probleme pratique est souvent caracterise par une geometrie non simple et des milieux tres differents. La technique de maillage utilisee (pas variable) permet d'approximer plus aisement les contours courbes, de repartir economiquement les points et de regulariser les discontinuites dues a deux milieux tres differents (difficulte de convergence). La technique de programmation par sous-programmes met a la disposition des ingenieurs non specialises dans le domaine numerique une methode iterative simple et sure: il suffit de passer tous les points en revue et d'appeler a chaque fois le sous-programme correspondant. (auteur)

  13. Public Lecture: The Odyssey of Voyager

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    Should you wish to attend to this lecture only (and not the full colloquium), please register here: https://indico.cern.ch/event/387001/registration/ Participants to the full colloquium are automatically registered to the public lectures.

  14. Dynamic contour tonometry: presentation of a new tonometer.

    Science.gov (United States)

    Kanngiesser, Hartmut E; Kniestedt, Christoph; Robert, Yves C A

    2005-10-01

    With tonometers currently in use intraocular pressure is indirectly determined by measuring a physical quantity related to a specified deformation of the cornea. We present a new principle of direct, continuous, and transcorneal intraocular pressure measurement, describe its theoretical foundation, and evaluate its application on the basis of an in vitro model. On a living human eye an optimized pressure-sensitive contact surface was determined by performing pressure measurements with differently shaped tonometer heads. Based on these results and on the theoretical model, a Dynamic Contour Tonometer was constructed and validated on eye bank bulbi against a manometric reference pressure. A concave contact surface with a radius of curvature of 10.5 mm creates a distribution of forces between the central contour matching area of the tip and the cornea that equals the forces generated by the internal pressure of the eye. A sensor integrated into the surface having the same contour measures the intraocular pressure closely to the manometric reference pressure in human cadaver eyes. The accuracy of the tonometer appears to be unaffected by variations in corneal properties. Dynamic Contour Tonometry eliminates most of the systematic errors arising from individual changes of corneal properties that adversely influence all types of applanation tonometers. The advantage of measuring the true pressure in combination with the capability of registering dynamic pressure fluctuations discloses new tonometric opportunities to diagnose and classify different types of glaucoma.

  15. Contour entropy: a new determinant of perceiving ground or a hole.

    Science.gov (United States)

    Gillam, Barbara J; Grove, Philip M

    2011-06-01

    Figure-ground perception is typically described as seeing one surface occluding another. Figure properties, not ground properties, are considered the significant factors. In scenes, however, a near surface will often occlude multiple contours and surfaces, often at different depths, producing alignments that are improbable except under conditions of occlusion. We thus hypothesized that unrelated (high entropy) lines would tend to appear as ground in a figure-ground paradigm more often than similarly aligned ordered (low entropy) lines. We further hypothesized that for lines spanning a closed area, high line entropy should increase the hole-like appearance of that area. These predictions were confirmed in three experiments. The probability that patterned rectangles were seen as ground when alternated with blank rectangles increased with pattern entropy. A single rectangular shape appeared more hole-like when the entropy of the enclosed contours increased. Furthermore, these same contours, with the outline shape removed, gave rise to bounding illusory contours whose strength increased with contour entropy. We conclude that figure-ground and hole perception can be determined by properties of ground in the absence of any figural shape, or surround, factors.

  16. Correlations between contouring similarity metrics and simulated treatment outcome for prostate radiotherapy

    Science.gov (United States)

    Roach, D.; Jameson, M. G.; Dowling, J. A.; Ebert, M. A.; Greer, P. B.; Kennedy, A. M.; Watt, S.; Holloway, L. C.

    2018-02-01

    Many similarity metrics exist for inter-observer contouring variation studies, however no correlation between metric choice and prostate cancer radiotherapy dosimetry has been explored. These correlations were investigated in this study. Two separate trials were undertaken, the first a thirty-five patient cohort with three observers, the second a five patient dataset with ten observers. Clinical and planning target volumes (CTV and PTV), rectum, and bladder were independently contoured by all observers in each trial. Structures were contoured on T2-weighted MRI and transferred onto CT following rigid registration for treatment planning in the first trial. Structures were contoured directly on CT in the second trial. STAPLE and majority voting volumes were generated as reference gold standard volumes for each structure for the two trials respectively. VMAT treatment plans (78 Gy to PTV) were simulated for observer and gold standard volumes, and dosimetry assessed using multiple radiobiological metrics. Correlations between contouring similarity metrics and dosimetry were calculated using Spearman’s rank correlation coefficient. No correlations were observed between contouring similarity metrics and dosimetry for CTV within either trial. Volume similarity correlated most strongly with radiobiological metrics for PTV in both trials, including TCPPoisson (ρ  =  0.57, 0.65), TCPLogit (ρ  =  0.39, 0.62), and EUD (ρ  =  0.43, 0.61) for each respective trial. Rectum and bladder metric correlations displayed no consistency for the two trials. PTV volume similarity was found to significantly correlate with rectum normal tissue complication probability (ρ  =  0.33, 0.48). Minimal to no correlations with dosimetry were observed for overlap or boundary contouring metrics. Future inter-observer contouring variation studies for prostate cancer should incorporate volume similarity to provide additional insights into dosimetry during analysis.

  17. Impact of abbreviated lecture with interactive mini-cases vs traditional lecture on student performance in the large classroom.

    Science.gov (United States)

    Marshall, Leisa L; Nykamp, Diane L; Momary, Kathryn M

    2014-12-15

    To compare the impact of 2 different teaching and learning methods on student mastery of learning objectives in a pharmacotherapy module in the large classroom setting. Two teaching and learning methods were implemented and compared in a required pharmacotherapy module for 2 years. The first year, multiple interactive mini-cases with inclass individual assessment and an abbreviated lecture were used to teach osteoarthritis; a traditional lecture with 1 inclass case discussion was used to teach gout. In the second year, the same topics were used but the methods were flipped. Student performance on pre/post individual readiness assessment tests (iRATs), case questions, and subsequent examinations were compared each year by the teaching and learning method and then between years by topic for each method. Students also voluntarily completed a 20-item evaluation of the teaching and learning methods. Postpresentation iRATs were significantly higher than prepresentation iRATs for each topic each year with the interactive mini-cases; there was no significant difference in iRATs before and after traditional lecture. For osteoarthritis, postpresentation iRATs after interactive mini-cases in year 1 were significantly higher than postpresentation iRATs after traditional lecture in year 2; the difference in iRATs for gout per learning method was not significant. The difference between examination performance for osteoarthritis and gout was not significant when the teaching and learning methods were compared. On the student evaluations, 2 items were significant both years when answers were compared by teaching and learning method. Each year, students ranked their class participation higher with interactive cases than with traditional lecture, but both years they reported enjoying the traditional lecture format more. Multiple interactive mini-cases with an abbreviated lecture improved immediate mastery of learning objectives compared to a traditional lecture format, regardless of

  18. Contouring a guide to the analysis and display of spatial data

    CERN Document Server

    Watson, Debbie

    2013-01-01

    This unique book is the key to computer contouring, exploring in detail the practice and principles using a personal computer. Contouring allows a three dimensional view in two dimensions and is a fundamental technique to represent spatial data. All aspects of this type of representation are covered including data preparation, selecting contour intervals, interpolation and griding, computing volumes and output and display. Formulated for both the novice and the experienced user, this book initially conducts the reader through a step by step explanation of PC software and its application to per

  19. An approach to contouring the dorsal vagal complex for radiotherapy planning

    Energy Technology Data Exchange (ETDEWEB)

    O' Steen, Lillie; Amdur, Robert J., E-mail: amdurr@shands.ufl.edu

    2016-04-01

    Multiple studies suggest that radiation dose to the area of the brainstem called the “dorsal vagal complex (DVC)” influences the frequency of nausea and vomiting during radiotherapy. The purpose of this didactic article is to describe the step-by-step process that we use to contour the general area of the DVC on axial computed tomography (CT) images as would be done for radiotherapy planning. The contouring procedure that we describe for contouring the area of the DVC is useful to medical dosimetrists and radiation oncologists.

  20. Towards Automated Lecture Capture, Navigation and Delivery System for Web-Lecture on Demand

    OpenAIRE

    Kannan, Rajkumar; Andres, Frederic

    2010-01-01

    Institutions all over the world are continuously exploring ways to use ICT in improving teaching and learning effectiveness. The use of course web pages, discussion groups, bulletin boards, and e-mails have shown considerable impact on teaching and learning in significant ways, across all disciplines. ELearning has emerged as an alternative to traditional classroom-based education and training and web lectures can be a powerful addition to traditional lectures. They can even serve as a main c...

  1. Standardization of surgical techniques used in facial bone contouring.

    Science.gov (United States)

    Lee, Tae Sung

    2015-12-01

    Since the introduction of facial bone contouring surgery for cosmetic purposes, various surgical methods have been used to improve the aesthetics of facial contours. In general, by standardizing the surgical techniques, it is possible to decrease complication rates and achieve more predictable surgical outcomes, thereby increasing patient satisfaction. The technical strategies used by the author to standardize facial bone contouring procedures are introduced here. The author uses various pre-manufactured surgical tools and hardware for facial bone contouring. During a reduction malarplasty or genioplasty procedure, double-bladed reciprocating saws and pre-bent titanium plates customized for the zygomatic body, arch and chin are used. Various guarded oscillating saws are used for mandibular angloplasty. The use of double-bladed saws and pre-bent plates to perform reduction malarplasty reduces the chances of post-operative asymmetry or under- or overcorrection of the zygoma contours due to technical faults. Inferior alveolar nerve injury and post-operative jawline asymmetry or irregularity can be reduced by using a guarded saw during mandibular angloplasty. For genioplasty, final placement of the chin in accordance with preoperative quantitative analysis can be easily performed with pre-bent plates, and a double-bladed saw allows more procedural accuracy during osteotomies. Efforts by the surgeon to avoid unintentional faults are key to achieving satisfactory results and reducing the incidence of complications. The surgical techniques described in this study in conjunction with various in-house surgical tools and modified hardware can be used to standardize techniques to achieve aesthetically gratifying outcomes. Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  2. Surface filling-in and contour interpolation contribute independently to Kanizsa figure formation.

    Science.gov (United States)

    Chen, Siyi; Glasauer, Stefan; Müller, Hermann J; Conci, Markus

    2018-04-30

    To explore mechanisms of object integration, the present experiments examined how completion of illusory contours and surfaces modulates the sensitivity of localizing a target probe. Observers had to judge whether a briefly presented dot probe was located inside or outside the region demarcated by inducer elements that grouped to form variants of an illusory, Kanizsa-type figure. From the resulting psychometric functions, we determined observers' discrimination thresholds as a sensitivity measure. Experiment 1 showed that sensitivity was systematically modulated by the amount of surface and contour completion afforded by a given configuration. Experiments 2 and 3 presented stimulus variants that induced an (occluded) object without clearly defined bounding contours, which gave rise to a relative sensitivity increase for surface variations on their own. Experiments 4 and 5 were performed to rule out that these performance modulations were simply attributable to variable distances between critical local inducers or to costs in processing an interrupted contour. Collectively, the findings provide evidence for a dissociation between surface and contour processing, supporting a model of object integration in which completion is instantiated by feedforward processing that independently renders surface filling-in and contour interpolation and a feedback loop that integrates these outputs into a complete whole. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  3. Purse-string platysmaplasty: the third dimension for neck contouring.

    Science.gov (United States)

    Gentile, Richard D

    2005-11-01

    Techniques and concepts for treatment of the aging neck have been evolving since the late 1960s and rely on two-dimensional anterior approximation with lateral imbrication of the platysma with or without submental fat reduction, However, the medial approximation can sometimes give a "boxy" appearance to the anterior neck, especially if anterior shifting of the platysma recurs after platysmaplasty with laxity redeveloping in this midline location. The "purse-string" platysmaplasty (PSP) is a new concept in neck contouring that facilitates an enhanced definition for the cervicomandibular transition to better simulate the well-defined contour of this transition that is present in youth. It aids in the contouring of difficult poorly defined necks and in male patients. The PSP adds a "third dimension" to neck recontouring by invaginating the platysma with a plication suture and pexing the platysma, without incising it, to deeper neck fascia with a technique that adds support and definition to the neck contour. The PSP can be performed in patients undergoing a full rhytidectomy as well as in individuals having isolated neck rejuvenation. The PSP is especially helpful in rejuvenating the male lower face and neck because of the relatively heavier deeper structures of the male neck and the need to enhance definition along the jawline.

  4. Lectures on Chevalley groups

    CERN Document Server

    Steinberg, Robert

    2016-01-01

    Robert Steinberg's Lectures on Chevalley Groups were delivered and written during the author's sabbatical visit to Yale University in the 1967-1968 academic year. The work presents the status of the theory of Chevalley groups as it was in the mid-1960s. Much of this material was instrumental in many areas of mathematics, in particular in the theory of algebraic groups and in the subsequent classification of finite groups. This posthumous edition incorporates additions and corrections prepared by the author during his retirement, including a new introductory chapter. A bibliography and editorial notes have also been added. This is a great unsurpassed introduction to the subject of Chevalley groups that influenced generations of mathematicians. I would recommend it to anybody whose interests include group theory. -Efim Zelmanov, University of California, San Diego Robert Steinberg's lectures on Chevalley groups were given at Yale University in 1967. The notes for the lectures contain a wonderful exposition of ...

  5. Lectures for CERN pensioners

    CERN Multimedia

    SC Unit

    2008-01-01

    The CERN Medical Service and the Pensioners Association are pleased to invite CERN pensioners to a series of lectures given by professors and specialists from the Teaching Hospitals and the Faculty of Medicine of the University of Geneva on the following topic: PROMOTION OF OPTIMUM BRAIN AGEING The lectures will take place in the Main CERN Auditorium (Building 60) from 2.30 p.m. to 4.30 p.m. on the following dates: Wednesday 12 November 2008: Assessing the extent of brain ageing Dr Dina ZEKRY Friday 12 December 2008: Can memory decline be prevented? Pr Jean-Pierre MICHEL Thursday 15 January 2009: Diagnosing and treating Alzheimer’s disease Pr Gabriel GOLD Wednesday 25 February 2009: What is the brain reserve? Speaker’s name to be announced at a later date The lectures will be given in French, with transparencies in English, and will be followed by a wide-ranging debate with the participants. CERN Medical Service - Pensioners Association - CERN-ESO (GAC-EPA)

  6. Lectures on functor homology

    CERN Document Server

    Touzé, Antoine

    2015-01-01

    This book features a series of lectures that explores three different fields in which functor homology (short for homological algebra in functor categories) has recently played a significant role. For each of these applications, the functor viewpoint provides both essential insights and new methods for tackling difficult mathematical problems. In the lectures by Aurélien Djament, polynomial functors appear as coefficients in the homology of infinite families of classical groups, e.g. general linear groups or symplectic groups, and their stabilization. Djament’s theorem states that this stable homology can be computed using only the homology with trivial coefficients and the manageable functor homology. The series includes an intriguing development of Scorichenko’s unpublished results. The lectures by Wilberd van der Kallen lead to the solution of the general cohomological finite generation problem, extending Hilbert’s fourteenth problem and its solution to the context of cohomology. The focus here is o...

  7. Lectures on quasiconformal mappings

    CERN Document Server

    Ahlfors, Lars V

    2006-01-01

    Lars Ahlfors's Lectures on Quasiconformal Mappings, based on a course he gave at Harvard University in the spring term of 1964, was first published in 1966 and was soon recognized as the classic it was shortly destined to become. These lectures develop the theory of quasiconformal mappings from scratch, give a self-contained treatment of the Beltrami equation, and cover the basic properties of Teichm�ller spaces, including the Bers embedding and the Teichm�ller curve. It is remarkable how Ahlfors goes straight to the heart of the matter, presenting major results with a minimum set of prerequisites. Many graduate students and other mathematicians have learned the foundations of the theories of quasiconformal mappings and Teichm�ller spaces from these lecture notes. This edition includes three new chapters. The first, written by Earle and Kra, describes further developments in the theory of Teichm�ller spaces and provides many references to the vast literature on Teichm�ller spaces and quasiconformal ...

  8. The Impact of Online Lecture Recordings on Student Performance

    Science.gov (United States)

    Williams, Andrew; Birch, Elisa; Hancock, Phil

    2012-01-01

    The use of online lecture recordings as a supplement to physical lectures is an increasingly popular tool at many universities. This paper combines survey data with student record data for students in a "Microeconomics Principles" class to examine the relative effects of lecture attendance and online lecture recordings. The main finding…

  9. Contour Detection for UAV-Based Cadastral Mapping

    Directory of Open Access Journals (Sweden)

    Sophie Crommelinck

    2017-02-01

    Full Text Available Unmanned aerial vehicles (UAVs provide a flexible and low-cost solution for the acquisition of high-resolution data. The potential of high-resolution UAV imagery to create and update cadastral maps is being increasingly investigated. Existing procedures generally involve substantial fieldwork and many manual processes. Arguably, multiple parts of UAV-based cadastral mapping workflows could be automated. Specifically, as many cadastral boundaries coincide with visible boundaries, they could be extracted automatically using image analysis methods. This study investigates the transferability of gPb contour detection, a state-of-the-art computer vision method, to remotely sensed UAV images and UAV-based cadastral mapping. Results show that the approach is transferable to UAV data and automated cadastral mapping: object contours are comprehensively detected at completeness and correctness rates of up to 80%. The detection quality is optimal when the entire scene is covered with one orthoimage, due to the global optimization of gPb contour detection. However, a balance between high completeness and correctness is hard to achieve, so a combination with area-based segmentation and further object knowledge is proposed. The localization quality exhibits the usual dependency on ground resolution. The approach has the potential to accelerate the process of general boundary delineation during the creation and updating of cadastral maps.

  10. On a program manifold's stability of one contour automatic control systems

    Science.gov (United States)

    Zumatov, S. S.

    2017-12-01

    Methodology of analysis of stability is expounded to the one contour systems automatic control feedback in the presence of non-linearities. The methodology is based on the use of the simplest mathematical models of the nonlinear controllable systems. Stability of program manifolds of one contour automatic control systems is investigated. The sufficient conditions of program manifold's absolute stability of one contour automatic control systems are obtained. The Hurwitz's angle of absolute stability was determined. The sufficient conditions of program manifold's absolute stability of control systems by the course of plane in the mode of autopilot are obtained by means Lyapunov's second method.

  11. Joint classification and contour extraction of large 3D point clouds

    Science.gov (United States)

    Hackel, Timo; Wegner, Jan D.; Schindler, Konrad

    2017-08-01

    We present an effective and efficient method for point-wise semantic classification and extraction of object contours of large-scale 3D point clouds. What makes point cloud interpretation challenging is the sheer size of several millions of points per scan and the non-grid, sparse, and uneven distribution of points. Standard image processing tools like texture filters, for example, cannot handle such data efficiently, which calls for dedicated point cloud labeling methods. It turns out that one of the major drivers for efficient computation and handling of strong variations in point density, is a careful formulation of per-point neighborhoods at multiple scales. This allows, both, to define an expressive feature set and to extract topologically meaningful object contours. Semantic classification and contour extraction are interlaced problems. Point-wise semantic classification enables extracting a meaningful candidate set of contour points while contours help generating a rich feature representation that benefits point-wise classification. These methods are tailored to have fast run time and small memory footprint for processing large-scale, unstructured, and inhomogeneous point clouds, while still achieving high classification accuracy. We evaluate our methods on the semantic3d.net benchmark for terrestrial laser scans with >109 points.

  12. Collinear facilitation and contour integration in autism: evidence for atypical visual integration.

    Science.gov (United States)

    Jachim, Stephen; Warren, Paul A; McLoughlin, Niall; Gowen, Emma

    2015-01-01

    Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impaired social interaction, atypical communication and a restricted repertoire of interests and activities. Altered sensory and perceptual experiences are also common, and a notable perceptual difference between individuals with ASD and controls is their superior performance in visual tasks where it may be beneficial to ignore global context. This superiority may be the result of atypical integrative processing. To explore this claim we investigated visual integration in adults with ASD (diagnosed with Asperger's Syndrome) using two psychophysical tasks thought to rely on integrative processing-collinear facilitation and contour integration. We measured collinear facilitation at different flanker orientation offsets and contour integration for both open and closed contours. Our results indicate that compared to matched controls, ASD participants show (i) reduced collinear facilitation, despite equivalent performance without flankers; and (ii) less benefit from closed contours in contour integration. These results indicate weaker visuospatial integration in adults with ASD and suggest that further studies using these types of paradigms would provide knowledge on how contextual processing is altered in ASD.

  13. Collinear facilitation and contour integration in autism: evidence for atypical visual integration

    Directory of Open Access Journals (Sweden)

    Stephen eJachim

    2015-03-01

    Full Text Available Autism spectrum disorder (ASD is a neurodevelopmental disorder characterized by impaired social interaction, atypical communication and a restricted repertoire of interests and activities. Altered sensory and perceptual experiences are also common, and a notable perceptual difference between individuals with ASD and controls is their superior performance in visual tasks where it may be beneficial to ignore global context. This superiority may be the result of atypical integrative processing. To explore this claim we investigated visual integration in adults with ASD (diagnosed with Asperger’s Syndrome using two psychophysical tasks thought to rely on integrative processing - collinear facilitation and contour integration. We measured collinear facilitation at different flanker orientation offsets and contour integration for both open and closed contours. Our results indicate that compared to matched controls, ASD participants show (i reduced collinear facilitation, despite equivalent performance without flankers and (ii less benefit from closed contours in contour integration. These results indicate weaker visuospatial integration in adults with ASD and suggest that further studies using these types of paradigms would provide knowledge on how contextual processing is altered in ASD.

  14. A historical note on illusory contours in shadow writing.

    Science.gov (United States)

    Vezzani, Stefano; Marino, Barbara F M

    2009-01-01

    It is widely accepted that illusory contours have been first displayed and discussed by Schumann (1900, Zeitschrift für Psychologie und Physiologie der Sinnesorgane 23 1-32). Here we show that, before him, Jastrow (1899, Popular Science Monthly 54 299-312) produced illusory contours consisting of a shadow word. A brief history of shadow writing in psychological literature from Jastrow to Brunswik is presented, in which the contributions of Pillsbury, Warren, Koffka, and Benussi are examined.

  15. "Annotated Lectures": Student-Instructor Interaction in Large-Scale Global Education

    Directory of Open Access Journals (Sweden)

    Roger Diehl

    2009-10-01

    Full Text Available We describe an "Annotated Lectures" system, which will be used in a global virtual teaching and student collaboration event on embodied intelligence presented by the University of Zurich. The lectures will be broadcasted via video-conference to lecture halls of different universities around the globe. Among other collaboration features, an "Annotated Lectures" system will be implemented in a 3D collaborative virtual environment and used by the participating students to make annotations to the video-recorded lectures, which will be sent to and answered by their supervisors, and forwarded to the lecturers in an aggregated way. The "Annotated Lectures" system aims to overcome the issues of limited studentinstructor interaction in large-scale education, and to foster an intercultural and multidisciplinary discourse among students who review the lectures in a group. After presenting the concept of the "Annotated Lectures" system, we discuss a prototype version including a description of the technical components and its expected benefit for large-scale global education.

  16. Interactive lectures: Clickers or personal devices?

    Science.gov (United States)

    Morrell, Lesley J; Joyce, Domino A

    2015-01-01

    Audience response systems ('clickers') are frequently used to promote participation in large lecture classes, and evidence suggests that they convey a number of benefits to students, including improved academic performance and student satisfaction. The limitations of these systems (such as limited access and cost) can be overcome using students' personal electronic devices, such as mobile phones, tablets and laptops together with text message, web- or app-based polling systems. Using questionnaires, we compare student perceptions of clicker and smartphone based polling systems. We find that students prefer interactive lectures generally, but those that used their own device preferred those lectures over lectures using clickers. However, device users were more likely to report using their devices for other purposes (checking email, social media etc.) when they were available to answer polling questions. These students did not feel that this distracted them from the lecture, instead, concerns over the use of smartphones centred around increased battery usage and inclusivity for students without access to suitable technology. Our results suggest that students generally preferred to use their own devices over clickers, and that this may be a sensible way to overcome some of the limitations associated with clickers, although issues surrounding levels of distraction and the implications for retention and recall of information need further investigation.

  17. Active Learning in ASTR 101 Lectures

    Science.gov (United States)

    Deming, Grace L.

    1998-12-01

    The lecture is the most common teaching method used at colleges and universities, but does this format facilitate student learning? Lectures can be brilliantly delivered, but they are received by a passive audience. As time passes during a lecture, student attention and effective notetaking diminish. Many students become more interested in a subject and retain information longer in courses that rely on active rather than passive teaching methods. Interactive teaching strategies such as the think-pair-share-(write), the 3-minute paper, and the misconception confrontation can be used to actively engage students during lecture. As a cooperative learning strategy, the think-pair-share-(write) technique requires active discussion by everyone in the class. The "write" component structures individual accountability into the activity. The 3-minute paper is an expansion of the standard 1-minute paper feedback technique, but is required of all students rather than voluntary or anonymous. The misconception confrontation technique allows students to focus on how their pre- conceived notions differ from the scientific explanation. These techniques can be easily adopted by anyone currently using a standard lecture format for introductory astronomy. The necessary components are a commitment by the instructor to require active participation by all students and a willingness to try new teaching methods.

  18. Interactive Lecture Experiments in Large Introductory Physics Classes

    Science.gov (United States)

    Milner-Bolotin, Marina M.; Kotlicki, A.; Rieger, G.; Bates, F.; Moll, R.; McPhee, K.; Nashon, S.

    2006-12-01

    We describe Interactive Lecture Experiments (ILE), which build on Interactive Lecture Demonstrations proposed by Sokoloff and Thornton (2004) and extends it by providing students with the opportunity to analyze experiments demonstrated in the lecture outside of the classroom. Real time experimental data is collected, using Logger Pro combined with the digital video technology. This data is uploaded to the Internet and made available to the students for further analysis. Student learning is assessed in the following lecture using conceptual questions (clickers). The goal of this project is to use ILE to make large lectures more interactive and promote student interest in science, critical thinking and data analysis skills. We report on the systematic study conducted using the Colorado Learning Attitudes about Science Survey, Force Concept Inventory, open-ended physics problems and focus group interviews to determine the impact of ILE on student academic achievement, motivation and attitudes towards physics. Three sections of students (750 students) experienced four ILE experiments. The surveys were administered twice and academic results for students who experienced the ILE for a particular topic were compared to the students, from a different section, who did not complete the ILE for that topic. Additional qualitative data on students’ attitudes was collected using open ended survey questions and interviews. We will present preliminary conclusions about the role of ILEs as an effective pedagogy in large introductory physics courses. Sokoloff, D.R. and R.K. Thornton (2004). Interactive Lecture Demonstrations: Active Learning in Introductory Physics, J.Wiley & Sons, INC. Interactive Lecture Experiments: http://www.physics.ubc.ca/ year1lab/p100/LectureLabs/lectureLabs.html

  19. Twenty lectures on thermodynamics

    CERN Document Server

    Buchdahl, H A

    2013-01-01

    Twenty Lectures on Thermodynamics is a course of lectures, parts of which the author has given various times over the last few years. The book gives the readers a bird's eye view of phenomenological and statistical thermodynamics. The book covers many areas in thermodynamics such as states and transition; adiabatic isolation; irreversibility; the first, second, third and Zeroth laws of thermodynamics; entropy and entropy law; the idea of the application of thermodynamics; pseudo-states; the quantum-static al canonical and grand canonical ensembles; and semi-classical gaseous systems. The text

  20. Lectures on Quantum Mechanics

    CERN Document Server

    Dirac, Paul Adrien Maurice

    1964-01-01

    The author of this concise, brilliant series of lectures on mathematical methods in quantum mechanics was one of the shining intellects in the field, winning a Nobel prize in 1933 for his pioneering work in the quantum mechanics of the atom. Beyond that, he developed the transformation theory of quantum mechanics (which made it possible to calculate the statistical distribution of certain variables), was one of the major authors of the quantum theory of radiation, codiscovered the Fermi-Dirac statistics, and predicted the existence of the positron.The four lectures in this book were delivered

  1. NSCT BASED LOCAL ENHANCEMENT FOR ACTIVE CONTOUR BASED IMAGE SEGMENTATION APPLICATION

    Directory of Open Access Journals (Sweden)

    Hiren Mewada

    2010-08-01

    Full Text Available Because of cross-disciplinary nature, Active Contour modeling techniques have been utilized extensively for the image segmentation. In traditional active contour based segmentation techniques based on level set methods, the energy functions are defined based on the intensity gradient. This makes them highly sensitive to the situation where the underlying image content is characterized by image nonhomogeneities due to illumination and contrast condition. This is the most difficult problem to make them as fully automatic image segmentation techniques. This paper introduces one of the approaches based on image enhancement to this problem. The enhanced image is obtained using NonSubsampled Contourlet Transform, which improves the edges strengths in the direction where the illumination is not proper and then active contour model based on level set technique is utilized to segment the object. Experiment results demonstrate that proposed method can be utilized along with existing active contour model based segmentation method under situation characterized by intensity non-homogeneity to make them fully automatic.

  2. A framework for automated contour quality assurance in radiation therapy including adaptive techniques

    International Nuclear Information System (INIS)

    Altman, M B; Kavanaugh, J A; Wooten, H O; Green, O L; DeWees, T A; Gay, H; Thorstad, W L; Li, H; Mutic, S

    2015-01-01

    Contouring of targets and normal tissues is one of the largest sources of variability in radiation therapy treatment plans. Contours thus require a time intensive and error-prone quality assurance (QA) evaluation, limitations which also impair the facilitation of adaptive radiotherapy (ART). Here, an automated system for contour QA is developed using historical data (the ‘knowledge base’). A pilot study was performed with a knowledge base derived from 9 contours each from 29 head-and-neck treatment plans. Size, shape, relative position, and other clinically-relevant metrics and heuristically derived rules are determined. Metrics are extracted from input patient data and compared against rules determined from the knowledge base; a computer-learning component allows metrics to evolve with more input data, including patient specific data for ART. Nine additional plans containing 42 unique contouring errors were analyzed. 40/42 errors were detected as were 9 false positives. The results of this study imply knowledge-based contour QA could potentially enhance the safety and effectiveness of RT treatment plans as well as increase the efficiency of the treatment planning process, reducing labor and the cost of therapy for patients. (paper)

  3. Effects of background and contour luminance on the hue and brightness of the Watercolor effect.

    Science.gov (United States)

    Gerardin, Peggy; Dojat, Michel; Knoblauch, Kenneth; Devinck, Frédéric

    2018-03-01

    Conjoint measurement was used to investigate the joint influences of the luminance of the background and the inner contour on hue- and brightness filling-in for a stimulus configuration generating a water-color effect (WCE), i.e., a wiggly bi-chromatic contour enclosing a region with the lower luminance component on the exterior. Two stimuli with the background and inner contour luminances covarying independently were successively presented, and in separate experiments, the observer judged which member of the pair's interior regions contained a stronger hue or was brighter. Braided-contour control stimuli that generated little or no perceptual filling-in were also used to assess whether observers were judging the interior regions and not the contours themselves. Three nested models of the contributions of the background and inner contour to the judgments were fit to the data by maximum likelihood and evaluated by likelihood ratio tests. Both stimulus components contributed to both the hue and brightness of the interior region with increasing luminance of the inner contour generating an assimilative filling-in for the hue judgments but a contrast effect for the brightness judgments. Control analyses showed negligible effects for the order of the luminance of the background or inner contour on the judgments. An additive contribution of both components was rejected in favor of a saturated model in which the responses depended on the levels of both stimulus components. For the hue judgments, increased background luminance led to greater hue filling-in at higher luminances of the interior contour. For the brightness judgments, the higher background luminance generated less brightness filling-in at higher luminances of the interior contour. The results indicate different effects of the inner contour and background on the induction of the brightness and coloration percepts of the WCE, suggesting that they are mediated by different mechanisms. Copyright © 2018 Elsevier

  4. The Effect of Instant Messaging on Lecture Retention

    Science.gov (United States)

    McVaugh, Nathan Kant

    2012-01-01

    The impact of instant message interruptions via computer on immediate lecture retention for college students was examined. While watching a 24-minute video of a classroom lecture, students received various numbers of related-to-lecture ("Is consistent use of the eye contact method necessary for success?") versus not-related-to lecture…

  5. Online Lectures in Undergraduate Medical Education: Scoping Review.

    Science.gov (United States)

    Tang, Brandon; Coret, Alon; Qureshi, Aatif; Barron, Henry; Ayala, Ana Patricia; Law, Marcus

    2018-04-10

    The adoption of the flipped classroom in undergraduate medical education calls on students to learn from various self-paced tools-including online lectures-before attending in-class sessions. Hence, the design of online lectures merits special attention, given that applying multimedia design principles has been shown to enhance learning outcomes. The aim of this study was to understand how online lectures have been integrated into medical school curricula, and whether published literature employs well-accepted principles of multimedia design. This scoping review followed the methodology outlined by Arksey and O'Malley (2005). Databases, including MEDLINE, PsycINFO, Education Source, FRANCIS, ERIC, and ProQuest, were searched to find articles from 2006 to 2016 related to online lecture use in undergraduate medical education. In total, 45 articles met our inclusion criteria. Online lectures were used in preclinical and clinical years, covering basic sciences, clinical medicine, and clinical skills. The use of multimedia design principles was seldom reported. Almost all studies described high student satisfaction and improvement on knowledge tests following online lecture use. Integration of online lectures into undergraduate medical education is well-received by students and appears to improve learning outcomes. Future studies should apply established multimedia design principles to the development of online lectures to maximize their educational potential. ©Brandon Tang, Alon Coret, Aatif Qureshi, Henry Barron, Ana Patricia Ayala, Marcus Law. Originally published in JMIR Medical Education (http://mededu.jmir.org), 10.04.2018.

  6. Classification of smooth Fano polytopes

    DEFF Research Database (Denmark)

    Øbro, Mikkel

    A simplicial lattice polytope containing the origin in the interior is called a smooth Fano polytope, if the vertices of every facet is a basis of the lattice. The study of smooth Fano polytopes is motivated by their connection to toric varieties. The thesis concerns the classification of smooth...... Fano polytopes up to isomorphism. A smooth Fano -polytope can have at most vertices. In case of vertices an explicit classification is known. The thesis contains the classification in case of vertices. Classifications of smooth Fano -polytopes for fixed exist only for . In the thesis an algorithm...... for the classification of smooth Fano -polytopes for any given is presented. The algorithm has been implemented and used to obtain the complete classification for ....

  7. Contour extraction of echocardiographic images based on pre-processing

    Energy Technology Data Exchange (ETDEWEB)

    Hussein, Zinah Rajab; Rahmat, Rahmita Wirza; Abdullah, Lili Nurliyana [Department of Multimedia, Faculty of Computer Science and Information Technology, Department of Computer and Communication Systems Engineering, Faculty of Engineering University Putra Malaysia 43400 Serdang, Selangor (Malaysia); Zamrin, D M [Department of Surgery, Faculty of Medicine, National University of Malaysia, 56000 Cheras, Kuala Lumpur (Malaysia); Saripan, M Iqbal

    2011-02-15

    In this work we present a technique to extract the heart contours from noisy echocardiograph images. Our technique is based on improving the image before applying contours detection to reduce heavy noise and get better image quality. To perform that, we combine many pre-processing techniques (filtering, morphological operations, and contrast adjustment) to avoid unclear edges and enhance low contrast of echocardiograph images, after implementing these techniques we can get legible detection for heart boundaries and valves movement by traditional edge detection methods.

  8. Contour extraction of echocardiographic images based on pre-processing

    International Nuclear Information System (INIS)

    Hussein, Zinah Rajab; Rahmat, Rahmita Wirza; Abdullah, Lili Nurliyana; Zamrin, D M; Saripan, M Iqbal

    2011-01-01

    In this work we present a technique to extract the heart contours from noisy echocardiograph images. Our technique is based on improving the image before applying contours detection to reduce heavy noise and get better image quality. To perform that, we combine many pre-processing techniques (filtering, morphological operations, and contrast adjustment) to avoid unclear edges and enhance low contrast of echocardiograph images, after implementing these techniques we can get legible detection for heart boundaries and valves movement by traditional edge detection methods.

  9. Surface roughness of zirconia for full-contour crowns after clinically simulated grinding and polishing.

    Science.gov (United States)

    Hmaidouch, Rim; Müller, Wolf-Dieter; Lauer, Hans-Christoph; Weigl, Paul

    2014-12-01

    The aim of this study was to evaluate the effect of controlled intraoral grinding and polishing on the roughness of full-contour zirconia compared to classical veneered zirconia. Thirty bar-shaped zirconia specimens were fabricated and divided into two groups (n=15). Fifteen specimens (group 1) were glazed and 15 specimens (group 2) were veneered with feldspathic ceramic and then glazed. Prior to grinding, maximum roughness depth (Rmax) values were measured using a profilometer, 5 times per specimen. Simulated clinical grinding and polishing were performed on the specimens under water coolant for 15 s and 2 N pressure. For grinding, NTI diamonds burs with grain sizes of 20 µm, 10 µm, and 7.5 µm were used sequentially. The ground surfaces were polished using NTI kits with coarse, medium and fine polishers. After each step, Rmax values were determined. Differences between groups were examined using one-way analysis of variance (ANOVA). The roughness of group 1 was significantly lower than that of group 2. The roughness increased significantly after coarse grinding in both groups. The results after glazing were similar to those obtained after fine grinding for non-veneered zirconia. However, fine-ground veneered zirconia had significantly higher roughness than venerred, glazed zirconia. No significant difference was found between fine-polished and glazed zirconia, but after the fine polishing of veneered zirconia, the roughness was significantly higher than after glazing. It can be concluded that for full-contour zirconia, fewer defects and lower roughness values resulted after grinding and polishing compared to veneered zirconia. After polishing zirconia, lower roughness values were achieved compared to glazing; more interesting was that the grinding of glazed zirconia using the NTI three-step system could deliver smooth surfaces comparable to untreated glazed zirconia surfaces.

  10. After massive weight loss: patients' expectations of body contouring surgery.

    Science.gov (United States)

    Kitzinger, Hugo B; Abayev, Sara; Pittermann, Anna; Karle, Birgit; Bohdjalian, Arthur; Langer, Felix B; Prager, Gerhard; Frey, Manfred

    2012-04-01

    Massive weight loss following bariatric surgery leads to excess skin with functional and aesthetic impairments. Surplus skin can then contribute to problems with additional weight loss or gain. The aims of the current study were to evaluate the frequency of massive soft tissue development in gastric bypass patients, to determine whether males and females experience similar post-bypass body changes, and to learn about the expectations and impairments related to body contouring surgery. A questionnaire addressing information on the satisfaction of body image, quality of life, and expectation of body contouring surgery following massive weight loss was mailed to 425 patients who had undergone gastric bypass surgery between 2003 and 2009. Of these 425 individuals, 252 (59%) patients completed the survey. Ninety percent of women and 88% of men surveyed rated their appearance following massive weight loss as satisfactory, good, or very good. However, 96% of all patients developed surplus skin, which caused intertriginous dermatitis and itching. In addition, patients reported problems with physical activity (playing sports) and finding clothing that fit appropriately. Moreover, 75% of female and 68% of male patients reported desiring body contouring surgery. The most important expectation of body contouring surgery was improved appearance, followed by improved self-confidence and quality of life. Surplus skin resulting from gastric bypass surgery is a common issue that causes functional and aesthetic impairments in patients. Consequently, this increases the desire for body contouring surgery with high expectations for the aesthetic outcome as well as improved life satisfaction.

  11. Lecturing and Loving It: Applying the Information-Processing Model.

    Science.gov (United States)

    Parker, Jonathan K.

    1993-01-01

    Discusses the benefits of lecturing, when done properly, in high schools. Describes the positive attributes of effective lecturers. Provides a human information-processing model applicable to the task of lecturing to students. (HB)

  12. An evaluation of the contouring abilities of medical dosimetry students for the anatomy of a prostate cancer patient

    International Nuclear Information System (INIS)

    Collins, Kevin S.

    2012-01-01

    Prostate cancer is one of the most common diseases treated in a radiation oncology department. One of the major predictors of the treatment outcome and patient side effects is the accuracy of the anatomical contours for the treatment plan. Therefore, the purpose of this study was to determine which anatomical structures are most often contoured correctly and incorrectly by medical dosimetry students. The author also wanted to discover whether a review of the contouring rules would increase contouring accuracy. To achieve this, a male computed tomography dataset consisting of 72 transverse slices was sent to students for contouring. The students were instructed to import this dataset into their treatment planning system and contour the following structures: skin, bladder, rectum, prostate, penile bulb, seminal vesicles, left femoral head, and right femoral head. Upon completion of the contours, the contour file was evaluated against a “gold standard” contour set using StructSure software (Standard Imaging, Inc). A review of the initial contour results was conducted and then students were instructed to contour the dataset a second time. The results of this study showed significant differences between contouring sessions. These results and the standardization of contouring rules should benefit all individuals who participate in the treatment planning of cancer patients.

  13. The inter-relationship between the periodontium and contours of artificial crowns

    International Nuclear Information System (INIS)

    Fareed, K.; Omar, R.

    1989-01-01

    The subject of axial contour of artificial crowns has and continues to be highly controversial. Much of the controversy centers arounrj whether the gingival sulcus is really in need of protection from buccal and/or lingual convexities, or whether a flatter emergence profile affords self cleansing muscle action. Evidence is reviewed in this part which suggests that overcontouring is probably more detrimental to gingival health than undercontouring. The critical role played by proper tooth reduction in attaining correct axial contour is shown and a rationale presented for the important interplay between preparation design, properties of the restorative materials to be employed and physiologic contour. (author)

  14. Summer Student Lecture Programme

    CERN Multimedia

    2004-01-01

    Main Auditorium, bldg. 500 More Information DATE TIME LECTURER TITLE Wednesday 7 July 09:15 - 10:00 L. Fayard, O. Ullaland, D. Heagerty (CERN) Programme Presentation Workshops presentation Information on Computing Rules 10:15 - 11:00 R. Aymar (CERN) Introduction to CERN (1/2) 11:15 - 12:00 J. Engelen (CERN) Introduction to CERN (2/2) 15:00 - 16:30 H. Menzel (CERN) An Introduction to Radiation Protection DATE TIME LECTURER TITLE Thursday 8 july 09:15 - 10:00 L. Di Lella (CERN) Introduction to Particle Physics (1/4) 10:15 - 11:00 L. Di Lella (CERN) Introduction to Particle Physics (2/4) 11:15 - 12:00 P. Chomaz (GANIL / CERN) Fundamental questions in modern nuclear physics: The challenge of exotic nuclei (1/2) DATE TIME LECTURER TITLE Friday 9 July 09:15 - 10:00 L. Di Lella (CERN) Introduction to Particle Physics (3/4) 10:15 - 11:00 P. Chomaz (GANIL / CERN) Fundamental questions in modern nuclear physics: The challenge of exotic nuclei (2/2) 11:15 - 12:00 P....

  15. Keynote Addresses from the Horace Mann Lecture Series and the Paul Masoner International Lecture Series 1972-1978.

    Science.gov (United States)

    Bender, Mary, Ed.

    The document contains eight lectures addressing a variety of educational trends, issues, and concerns. The objective is to heighten the awareness of educational challenges that must be met and to promote continued professional renewal activities. Lecture I discusses fundamental problems concerning world education, concentrating on hunger and…

  16. On performing concepts during science lectures

    Science.gov (United States)

    Pozzer-Ardenghi, Lilian; Roth, Wolff-Michael

    2007-01-01

    When lecturing, teachers make use of both verbal and nonverbal communication. What is called teaching, therefore, involves not only the words and sentences a teacher utters and writes on the board during a lesson, but also all the hands/arms gestures, body movements, and facial expressions a teacher performs in the classroom. All of these communicative modalities constitute resources that are made available to students for making sense of and learning from lectures. Yet in the literature on teaching science, these other means of communication are little investigated and understood - and, correspondingly, they are undertheorized. The purpose of this position paper is to argue for a different view of concepts in lectures: they are performed simultaneously drawing on and producing multiple resources that are different expressions of the same holistic meaning unit. To support our point, we provide examples from a database of 26 lectures in a 12th-grade biology class, where the human body was the main topic of study. We analyze how different types of resources - including verbal and nonverbal discourse and various material artifacts - interact during lectures. We provide evidence for the unified production of these various sense-making resources during teaching to constitute a meaning unit, and we emphasize particularly the use of gestures and body orientations inside this meaning unit. We suggest that proper analyses of meaning units need to take into account not only language and diagrams but also a lecturer's pointing and depicting gestures, body positions, and the relationships between these different modalities. Scientific knowledge (conceptions) exists in the concurrent display of all sense-making resources, which we, following Vygotsky, understand as forming a unit (identity) of nonidentical entities.

  17. Student Use of Mobile Devices in University Lectures

    Science.gov (United States)

    Roberts, Neil; Rees, Michael

    2014-01-01

    Mobile devices are increasingly used by students in university lectures. This has resulted in controversy and the banning of mobile devices in some lectures. Although there has been some research into how students use laptop computers in lectures, there has been little investigation into the wider use of mobile devices. This study was designed to…

  18. Calf Contouring with Endoscopic Fascial Release, Calf Implant, and Structural Fat Grafting

    Directory of Open Access Journals (Sweden)

    Ercan Karacaoglu, MD

    2013-08-01

    Conclusions: A novel endoscopic approach for lower leg contouring is discussed. Endoscopic fasciotomy technique with calf implant and structural fat grafting for improved lower leg aesthetics is a simple, effective, reliable, and predictable technique for calf contouring.

  19. Robust iterative learning contouring controller with disturbance observer for machine tool feed drives.

    Science.gov (United States)

    Simba, Kenneth Renny; Bui, Ba Dinh; Msukwa, Mathew Renny; Uchiyama, Naoki

    2018-04-01

    In feed drive systems, particularly machine tools, a contour error is more significant than the individual axial tracking errors from the view point of enhancing precision in manufacturing and production systems. The contour error must be within the permissible tolerance of given products. In machining complex or sharp-corner products, large contour errors occur mainly owing to discontinuous trajectories and the existence of nonlinear uncertainties. Therefore, it is indispensable to design robust controllers that can enhance the tracking ability of feed drive systems. In this study, an iterative learning contouring controller consisting of a classical Proportional-Derivative (PD) controller and disturbance observer is proposed. The proposed controller was evaluated experimentally by using a typical sharp-corner trajectory, and its performance was compared with that of conventional controllers. The results revealed that the maximum contour error can be reduced by about 37% on average. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

  20. Technical report on the surface reconstruction of stacked contours by using the commercial software

    Science.gov (United States)

    Shin, Dong Sun; Chung, Min Suk; Hwang, Sung Bae; Park, Jin Seo

    2007-03-01

    After drawing and stacking contours of a structure, which is identified in the serially sectioned images, three-dimensional (3D) image can be made by surface reconstruction. Usually, software is composed for the surface reconstruction. In order to compose the software, medical doctors have to acquire the help of computer engineers. So in this research, surface reconstruction of stacked contours was tried by using commercial software. The purpose of this research is to enable medical doctors to perform surface reconstruction to make 3D images by themselves. The materials of this research were 996 anatomic images (1 mm intervals) of left lower limb, which were made by serial sectioning of a cadaver. On the Adobe Photoshop, contours of 114 anatomic structures were drawn, which were exported to Adobe Illustrator files. On the Maya, contours of each anatomic structure were stacked. On the Rhino, superoinferior lines were drawn along all stacked contours to fill quadrangular surfaces between contours. On the Maya, the contours were deleted. 3D images of 114 anatomic structures were assembled with their original locations preserved. With the surface reconstruction technique, developed in this research, medical doctors themselves could make 3D images of the serially sectioned images such as CTs and MRIs.

  1. Mandibular marginal contouring in oriental aesthetic surgery: refined surgical concept and operative procedure.

    Science.gov (United States)

    Satoh, Kaneshige; Mitsukawa, Nobuyuki

    2014-05-01

    In aesthetic mandibular contouring surgery, which is often conducted in Asians, the operative procedure is thought to deliver a more aesthetic mandibular shape by means of contouring conducted as a whole from the ramus to the symphysis. The authors describe the refined concept and operative procedures of mandibular marginal contouring. For the 7-year period from 2004 to 2011, mandibular marginal contouring has been used in 57 consecutive series of Japanese subjects. Patient ages ranged from 18 to 33 years, and the subjects included 15 men and 42 women. The surgery was carried out by cutting off the protruding deformed mandibular margin from the ramus to the symphysis. In 53 of 57 cases, the focus was on angle contouring. Concomitant genioplasty by horizontal osteotomy of the chin was conducted in 42 of 57 cases (recession, advancement, shortening, elongation, and correction of the shift variously). In 22 materials exhibiting bulk around the mandibular, the ramus to the body was excised sagittally and thinned. In all the patients, mandibular marginal contouring from the ramus to the symphysis was completed. Partial masseter muscle resection was conducted in 11 of 57 cases. Mandibular contouring effectively achieved a highly satisfactory result in all cases. The upper portion of the peripheral branch of the trunk of the mental nerve was dissected by an electric scalpel in 1 case but sutured immediately using an 8-0 nylon stitch. Transient palsy of the mental nerve was noticed in a few cases but subsided in 1 to 2 months. No particular complications were encountered. No secondary revision was required in this series. In mandibular angle plasty, mandibular marginal contouring from the ramus to the symphysis should be carried out by cutting off the angle keeping in mind the entire mandibular shape. This concept and the procedure can deliver greater patient satisfaction.

  2. Pre- and postoperative quantitative analysis of contour abnormalities in Graves upper eyelid retraction.

    Science.gov (United States)

    Ribeiro, Sara F T; Milbratz, Gherusa H; Garcia, Denny M; Devoto, Martin; Guilherme Neto, H; Mörschbächer, Ricardo; Pereira, Filipe J; Cruz, Antonio A V

    2012-01-01

    One of the most common problems of the surgical management of Graves upper eyelid retraction is the occurrence of eyelid contour abnormalities. In the present study, the postoperative contour of a large sample of eyelids of patients with Graves orbitopathy was measured. The postoperative upper eyelid contour of 62 eyes of 43 patients with Graves orbitopathy was subjectively classified by 3 experienced surgeons in 3 categories: poor, fair, and good. The shape of the eyelid contours in each category was then measured with a recently developed custom-made software by measuring multiple midpupil eyelid distances each 15° along the palpebral fissure. The upper eyelid contour of 60 normal subjects was also quantified as a control group. The mean ratio between the sum of the lateral and medial midpupil eyelid distances (lateral/medial ratio) was 1.10 ± 0.11 standard deviation in controls and 1.15 ± 0.13 standard deviation in patients. Postoperatively, the mean midpupil eyelid distance at 90° was 4.16 ± 1.13 mm standard deviation. The distribution lateral/medial ratios of the eyelids judged as having good contours was similar to the distribution of the controls with a modal value centered on the interval between 1.0 and 1.10. The distribution of lateral/medial ratios of the eyelids judged as having poor contour was bimodal, with eyelids with low and high lateral/medial ratios. Low lateral/medial ratios occurred when there was a lateral overcorrection, giving the eyelid a flat or a medial ptosis appearance. High lateral/medial ratios were due to a central or medial overcorrection or a lateral peak maintenance. Postoperative upper eyelid contour abnormalities can be quantified by comparing the sum of multiple midpupil eyelid distances of the lateral and medial sectors of the eyelid. Low and high lateral/medial ratios are anomalous and judged as unpleasant.

  3. The Main Cognitive Model of Visual Recognition: Contour Recognition

    OpenAIRE

    Chen, YongHong

    2017-01-01

    In this paper, we will study the following pattern recognition problem: Every pattern is a 3-dimensional graph, its surface can be split up into some regions, every region is composed of the pixels with the approximately same colour value and the approximately same depth value that is distance to eyes, and there may also be some contours, e.g., literal contours, on a surface of every pattern. For this problem we reveal the inherent laws. Moreover, we establish a cognitive model to reflect the...

  4. Complications following body contouring surgery after massive weight loss

    DEFF Research Database (Denmark)

    Hasanbegovic, Emir; Sørensen, Jens Ahm

    2014-01-01

    Bariatric surgery is a way to achieve lasting weight loss in the obese. Body contouring surgery seeks to alleviate some of the discomfort caused by the excessive loose skin following massive weight loss. Higher complication rates are described in this type of surgery when done post......-bariatric. The purpose of this article is to compare complication rates of body contouring surgery when performed on patients with weight loss due to bariatric surgery compared to patients who lost weight due to dietary changes and/or exercise....

  5. Perceptions of Students and Self- assessment of Lecturers on ...

    African Journals Online (AJOL)

    assessments of lecturers on written essay error feedback. Overall 153 University of Botswana students and 20 lecturers participated in this study. All the students and 12 lecturers completed different but related questionnaires with both closed and ...

  6. Lectures Abandoned: Active Learning by Active Seminars

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak; Corry, Aino Vonge

    2012-01-01

    Traditional lecture-based courses are widely criticised for be- ing less eective in teaching. The question is of course what should replace the lectures and various active learning tech- niques have been suggested and studied. In this paper, we report on our experiences of redesigning a software ......- tive seminars as a replacement of traditional lectures, an activity template for the contents of active seminars, an ac- count on how storytelling supported the seminars, as well as reports on our and the students' experiences....

  7. Brightness Alteration with Interweaving Contours

    Directory of Open Access Journals (Sweden)

    Sergio Roncato

    2012-12-01

    Full Text Available Chromatic induction is observed whenever the perceived colour of a target surface shifts towards the hue of a neighbouring surface. Some vivid manifestations may be seen in a white background where thin coloured lines have been drawn (assimilation or when lines of different colours are collinear (neon effect or adjacent (watercolour to each other. This study examines a particular colour induction that manifests in concomitance with an opposite effect of colour saturation (or anti-spread. The two phenomena can be observed when a repetitive pattern is drawn in which outline thin contours intercept wider contours or surfaces, colour spreading appear to fill the surface occupied by surfaces or thick lines whereas the background traversed by thin lines is seen as brighter or filled of a saturated white. These phenomena were first observed by Bozzi (1975 and Kanizsa (1979 in figural conditions that did not allow them to document their conjunction. Here we illustrate various manifestations of this twofold phenomenon and compare its effects with the known effects of brightness and colour induction. Some conjectures on the nature of these effects are discussed.

  8. The Challenges of Listening to Academic Lectures for EAP Learners and the Impact of Metacognition on Academic Lecture Listening Comprehension

    Directory of Open Access Journals (Sweden)

    Maryam Rahimirad

    2015-06-01

    Full Text Available Academic listening skill is an indispensable necessity for English for academic purposes (EAP students in English-medium universities and also critical for their future success in comprehending conference lectures. But due to the specific nature of such academic lectures, nonnative students all too often face challenges in getting a full command of this task. This study investigates the challenges of listening to academic lectures and the impact of related metacognitive strategies on academic lecture listening comprehension on a group of Iranian learners in an EAP workshop. Fifteen academic staff who took part in two intact classes at the University of Qom, Iran, were randomly assigned to treatment (N = 8 and control (N = 7 groups. The treatment group received 16 hr of metacognitive strategy instruction based on the models proposed by Vandergrift during academic listening instruction, while the control group was just exposed to academic lectures with no explicit strategy instruction. The academic listening sections of the British International English Language Testing System (IELTS were utilized to measure the listening comprehension of both groups before and after the treatment. The results of the data analysis determined that the experimental group significantly outperformed the control group in the listening posttest. The interviews before and after the treatment revealed details of challenges in academic lecture comprehension and also shed light on the perception of the learners regarding metacognitive strategy instruction and the frequency of main metacognitive strategies used in comprehending academic lectures.

  9. Contours, 2 foot contours automatically generated from 2008 LIDAR for the purpose of supporting FEMA floodplain mapping. Limited manual editing, breaklines for waterbodies greater than 5 acres created and use.10' index contours labeled., Published in 2008, 1:1200 (1in=100ft) scale, City of Portage Government.

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Contours dataset current as of 2008. 2 foot contours automatically generated from 2008 LIDAR for the purpose of supporting FEMA floodplain mapping. Limited manual...

  10. I/O-Efficient Algorithms for Computing Contour Lines on a Terrain

    DEFF Research Database (Denmark)

    Agarwal, Pankaj Kumar; Arge, Lars; Sadri, Bardia

    2008-01-01

    A terrain M is the graph of a bivariate function. We assume that M is represented as a triangulated surface with N vertices. A contour (or isoline) of M is a connected component of a level set of M. Generically, each contour is a closed polygonal curve; at "critical" levels these curves may touch...

  11. Should Lecture Recordings Be Mandated in Dental Schools? Two Viewpoints: Viewpoint 1: Lecture Recordings Should Be Mandatory in U.S. Dental Schools and Viewpoint 2: Lecture Recordings Should Not Be Mandatory in U.S. Dental Schools.

    Science.gov (United States)

    Zandona, Andrea Ferreira; Kinney, Janet; Seong, WookJin; Kumar, Vandana; Bendayan, Alexander; Hewlett, Edmond

    2016-12-01

    Transcription or recording of lectures has been in use for many years, and with the availability of high-fidelity recording, the practice is now ubiquitous in higher education. Since technology has permeated education and today's tech-savvy students have expectations for on-demand learning, dental schools are motivated to record lectures, albeit with positive and negative implications. This Point/Counterpoint article addresses the question of whether lecture recording should be mandatory in U.S. dental schools. Viewpoint 1 supports the statement that lecture recording should be mandatory. Proponents of this viewpoint argue that the benefits-notably, student satisfaction and potential for improvement in student performance-outweigh concerns. Viewpoint 2 takes the opposite position, arguing that lecture recording decreases students' classroom attendance and adversely affects the morale of educators. Additional arguments against mandatory lecture recordings involve the expense of incorporating technology that requires ongoing support.

  12. Maintaining Contour Trees of Dynamic Terrains

    DEFF Research Database (Denmark)

    Agarwal, Pankaj K.; Mølhave, Thomas; Revsbæk, Morten

    2015-01-01

    We study the problem of maintaining the contour tree T of a terrain Sigma, represented as a triangulated xy-monotone surface, as the heights of its vertices vary continuously with time. We characterize the combinatorial changes in T and how they relate to topological changes in Sigma. We present ...

  13. A phantom study of tumor contouring on PET imaging

    International Nuclear Information System (INIS)

    Chen Song; Li Xuena; Li Yaming; Yin Yafu; Li Na; Han Chunqi

    2010-01-01

    Objective: To explore an algorithm to define the threshold value for tumor contouring on 18 F-fluorodeoxyglucose (FDG) PET imaging. Methods: A National Electrical Manufacturing Association (NEMA)NU 2 1994 PET phantom with 5 spheres of different diameters were filled with 18 F-FDG. Seven different sphere-to-background ratios were obtained and the phantom was scanned by Discovery LS 4. For each sphere-to-background ratio, the maximum standardized uptake value (SUV max ) of each sphere, the SUV of the border of each sphere (SUV border ), the mean SUV of a 1 cm region of background (SUV bg ) and the diameter (D) of each sphere were measured. SPSS 13.0 software was used for curve fitting and regression analysis to obtain the threshold algorithm. The calculated thresholds were applied to delineate 29 pathologically confirmed lung cancer lesions on PET images and the obtained volumes were compared with the volumes contoured on CT images in lung window. Results: The algorithm for defining contour threshold is TH% = 33.1% + 46.8% SUV bg /SUV max + 13.9%/D (r = 0.994) by phantom studies. For 29 lung cancer lesions, the average gross tumor volumes (GTV) delineated on PET and CT are (7.36±1.62) ml and (8.31±2.05) ml, respectively (t = -1.26, P>0.05). Conclusion: The proposed threshold algorithm for tumor contouring on PET image could provide comparable GTV with CT. (authors)

  14. Taxonomy of Lecture Note-Taking Skills and Subskills

    Science.gov (United States)

    Al-Musalli, Alaa M.

    2015-01-01

    Note taking (NT) in lectures is as active a skill as listening, which stimulates it, and as challenging as writing, which is the end product. Literature on lecture NT misses an integration of the processes involved in listening with those in NT. In this article, a taxonomy is proposed of lecture NT skills and subskills based on a similar list…

  15. Using lecture capture: a qualitative study of nursing faculty's experience.

    Science.gov (United States)

    Freed, Patricia E; Bertram, Julie E; McLaughlin, Dorcas E

    2014-04-01

    As lecture capture technology becomes widely available in schools of nursing, faculty will need to master new technological skills and make decisions about recording their classroom lectures or other activities. This study sought to understand faculty's experience of using a new lecture capture system. This qualitative study used Kruger's systematic approach to explore undergraduate nursing faculty's first-time experience using a lecture capture system purchased by the university. Four focus groups were conducted with a total of fourteen undergraduate faculty using lecture capture for the first-time. The interviews were recorded and transcribed and then analyzed by the researchers. Four themes were identified from the faculty interviews. Two of the themes expressed faculty's concerns about the teaching role, and two themes expressed the faculty's concerns about student learning. Participants experienced stress when learning to use the new lecture capture technology and struggled to resolve it with their own beliefs and teaching values. The impact of lecture capture on student learning, impact on class attendance, and the promotion of a culture of lecturing were revealed as important issues to consider when lecture capture becomes available. © 2013.

  16. Direct Optimization of Printed Reflectarrays for Contoured Beam Satellite Antenna Applications

    DEFF Research Database (Denmark)

    Zhou, Min; Sorensen, Stig B.; Kim, Oleksiy S.

    2013-01-01

    An accurate and efficient direct optimization technique for the design of contoured beam reflectarrays is presented. It is based on the spectral domain method of moments assuming local periodicity and minimax optimization. Contrary to the conventional phase-only optimization techniques, the geome......An accurate and efficient direct optimization technique for the design of contoured beam reflectarrays is presented. It is based on the spectral domain method of moments assuming local periodicity and minimax optimization. Contrary to the conventional phase-only optimization techniques......, the geometrical parameters of the array elements are directly optimized to fulfill the contoured beam requirements, thus maintaining a direct relation between optimization goals and optimization variables, and hence resulting in more optimal designs. Both co- and cross-polar radiation patterns of the reflectarray...... can be optimized for multiple frequencies, polarizations, and feed illuminations. Several contoured beam reflectarrays, that radiate a high-gain beam on a European coverage, have been designed and compared to similar designs obtained using the phase-only optimization technique. The comparisons show...

  17. Expert Consensus Contouring Guidelines for Intensity Modulated Radiation Therapy in Esophageal and Gastroesophageal Junction Cancer

    International Nuclear Information System (INIS)

    Wu, Abraham J.; Bosch, Walter R.; Chang, Daniel T.; Hong, Theodore S.; Jabbour, Salma K.; Kleinberg, Lawrence R.; Mamon, Harvey J.; Thomas, Charles R.; Goodman, Karyn A.

    2015-01-01

    Purpose/Objective(s): Current guidelines for esophageal cancer contouring are derived from traditional 2-dimensional fields based on bony landmarks, and they do not provide sufficient anatomic detail to ensure consistent contouring for more conformal radiation therapy techniques such as intensity modulated radiation therapy (IMRT). Therefore, we convened an expert panel with the specific aim to derive contouring guidelines and generate an atlas for the clinical target volume (CTV) in esophageal or gastroesophageal junction (GEJ) cancer. Methods and Materials: Eight expert academically based gastrointestinal radiation oncologists participated. Three sample cases were chosen: a GEJ cancer, a distal esophageal cancer, and a mid-upper esophageal cancer. Uniform computed tomographic (CT) simulation datasets and accompanying diagnostic positron emission tomographic/CT images were distributed to each expert, and the expert was instructed to generate gross tumor volume (GTV) and CTV contours for each case. All contours were aggregated and subjected to quantitative analysis to assess the degree of concordance between experts and to generate draft consensus contours. The panel then refined these contours to generate the contouring atlas. Results: The κ statistics indicated substantial agreement between panelists for each of the 3 test cases. A consensus CTV atlas was generated for the 3 test cases, each representing common anatomic presentations of esophageal cancer. The panel agreed on guidelines and principles to facilitate the generalizability of the atlas to individual cases. Conclusions: This expert panel successfully reached agreement on contouring guidelines for esophageal and GEJ IMRT and generated a reference CTV atlas. This atlas will serve as a reference for IMRT contours for clinical practice and prospective trial design. Subsequent patterns of failure analyses of clinical datasets using these guidelines may require modification in the future

  18. ACADEMIC TRAINING LECTURE

    CERN Multimedia

    Academic Training; Tel. 73127

    2001-01-01

    23, 24, 25, 26 and 27 April REGULAR LECTURE PROGRAMME From 11:00 hrs - Main Auditorium bldg. 500, on 23 April from 11:15 to 12:15 hrs Searches for Dark Matter F. Feinstein / CPPM, Marseille, F The fact that the mass of the visible stars could not account for the gravitational cohesion of the galaxy clusters was the first manifestation of non-radiating matter in the Universe. Since then, many observations imply that most of the matter is indeed dark. Its nature is still unknown and likely to have several contributions. Recent results indicate that most of it may not be composed of normal matter. These lectures will review the experimental methods, which have been developed to unravel this 70-year long mystery and confront their results with the current theoretical framework of cosmology.

  19. Academic Training: Summer Student Lecture Programme

    CERN Multimedia

    2004-01-01

    Main Auditorium, bldg. 500 DATE TIME LECTURER TITLE Monday 26 July 09:15 - 10:00 A. Pich (IFIC) The Standard Model (7/8) 10:15 - 11:00 R. Rattazzi (CERN) Beyond the Standard Model (1/3) 11:15 - 12:00 K. Jacobs (Universität Freiburg) Physics in Hadronic Colliders (1/4) DATE TIME LECTURER TITLE Tuesday 27 July 09:15 - 10:00 A. Pich (IFIC) The Standard Model (8/8) 10:15 - 11:00 R. Rattazzi (CERN) Beyond the Standard Model (2/3) 11:15 - 12:00 R. Rattazzi (CERN) A. Pich (IFIC) Discussion Session DATE TIME LECTURER TITLE Wednesday 28 July 09:15 - 10:00 K. Jacobs (Universität Freiburg) Physics in Hadronic Colliders (2/4) 10:15 - 11:00 K. Jacobs (Universität Freiburg) Physics in Hadronic Colliders (3/4) 11:15 - 12:00 R. Rattazzi (CERN) Beyond the Standard Model (3/3) 14:00 - 15:00 R. Assmann (CERN) The CLIC project DATE TIME LECTURER TITLE Thursday 29 July 09:15 - 10:00 K. Jacobs (Universität Freiburg) Physics in Hadronic ...

  20. Modeling of the time sharing for lecturers

    Directory of Open Access Journals (Sweden)

    E. Yu. Shakhova

    2017-01-01

    Full Text Available In the context of modernization of the Russian system of higher education, it is necessary to analyze the working time of the university lecturers, taking into account both basic job functions as the university lecturer, and others.The mathematical problem is presented for the optimal working time planning for the university lecturers. The review of the documents, native and foreign works on the study is made. Simulation conditions, based on analysis of the subject area, are defined. Models of optimal working time sharing of the university lecturers («the second half of the day» are developed and implemented in the system MathCAD. Optimal solutions have been obtained.Three problems have been solved:1 to find the optimal time sharing for «the second half of the day» in a certain position of the university lecturer;2 to find the optimal time sharing for «the second half of the day» for all positions of the university lecturers in view of the established model of the academic load differentiation;3 to find the volume value of the non-standardized part of time work in the department for the academic year, taking into account: the established model of an academic load differentiation, distribution of the Faculty number for the positions and the optimal time sharing «the second half of the day» for the university lecturers of the department.Examples are given of the analysis results. The practical application of the research: the developed models can be used when planning the working time of an individual professor in the preparation of the work plan of the university department for the academic year, as well as to conduct a comprehensive analysis of the administrative decisions in the development of local university regulations.

  1. Kepler Planet Detection Metrics: Per-Target Detection Contours for Data Release 25

    Science.gov (United States)

    Burke, Christopher J.; Catanzarite, Joseph

    2017-01-01

    A necessary input to planet occurrence calculations is an accurate model for the pipeline completeness (Burke et al., 2015). This document describes the use of the Kepler planet occurrence rate products in order to calculate a per-target detection contour for the measured Data Release 25 (DR25) pipeline performance. A per-target detection contour measures for a given combination of orbital period, Porb, and planet radius, Rp, what fraction of transit signals are recoverable by the Kepler pipeline (Twicken et al., 2016; Jenkins et al., 2017). The steps for calculating a detection contour follow the procedure outlined in Burke et al. (2015), but have been updated to provide improved accuracy enabled by the substantially larger database of transit injection and recovery tests that were performed on the final version (i.e., SOC 9.3) of the Kepler pipeline (Christiansen, 2017; Burke Catanzarite, 2017a). In the following sections, we describe the main inputs to the per-target detection contour and provide a worked example of the python software released with this document (Kepler Planet Occurrence Rate Tools KeplerPORTs)1 that illustrates the generation of a detection contour in practice. As background material for this document and its nomenclature, we recommend the reader be familiar with the previous method of calculating a detection contour (Section 2 of Burke et al.,2015), input parameters relevant for describing the data quantity and quality of Kepler targets (Burke Catanzarite, 2017b), and the extensive new transit injection and recovery tests of the Kepler pipeline (Christiansen et al., 2016; Burke Catanzarite, 2017a; Christiansen, 2017).

  2. Professionalism of Lecturers at Faculty of Education

    Science.gov (United States)

    Tangkere, T. F. S.; Langitan, F. W.; Maukar, S. M. D.; Roring, R. F.

    2018-02-01

    The main objective of this research was to get the picture pertaining to the professionalization of Lecturers at Faculty of Education in Manado State University, Indonesia. The research method was naturalistic inquiry with qualitative approach. The research techniques were: deep interview, participative observation and document study. The data were analyzed by: data reduction, data display and conclusions, while the validation of data was done by four criteria, namely: credibility, transferability, dependability and conformability. The collecting procedure and data recording were done through observation and interviews. From the findings and conclusions, it can be identified that professionalization of Lecturers at Faculty of Education in Manado State University has been well processed. This can be proved by fulfillment of the minimum academic standard Ninety-one out of the total l12 lecturers has been certified. Based on conclusions, the researcher recommends that the teacher always develop their capability through increasing their academic qualification, self-development through attending educational trainings, conducting more research and publishing those researches through accredited journals. Dean of every Faculty and also execute supporting activities which will support self-development of the lectures and increase the budget for research of the lecturers.

  3. Self-adaptive method to distinguish inner and outer contours of industrial computed tomography image for rapid prototype

    International Nuclear Information System (INIS)

    Duan Liming; Ye Yong; Zhang Xia; Zuo Jian

    2013-01-01

    A self-adaptive identification method is proposed for realizing more accurate and efficient judgment about the inner and outer contours of industrial computed tomography (CT) slice images. The convexity-concavity of the single-pixel-wide closed contour is identified with angle method at first. Then, contours with concave vertices are distinguished to be inner or outer contours with ray method, and contours without concave vertices are distinguished with extreme coordinate value method. The method was chosen to automatically distinguish contours by means of identifying the convexity and concavity of the contours. Thus, the disadvantages of single distinguishing methods, such as ray method's time-consuming and extreme coordinate method's fallibility, can be avoided. The experiments prove the adaptability, efficiency, and accuracy of the self-adaptive method. (authors)

  4. Retroperitoneal Sarcoma Target Volume and Organ at Risk Contour Delineation Agreement Among NRG Sarcoma Radiation Oncologists

    Energy Technology Data Exchange (ETDEWEB)

    Baldini, Elizabeth H., E-mail: ebaldini@partners.org [Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women' s Hospital, Boston, Massachusetts (United States); Abrams, Ross A. [Department of Radiation Oncology, Rush University Medical Center, Chicago, Illinois (United States); Bosch, Walter [Department of Radiation Oncology, Washington University, St. Louis, Missouri (United States); Roberge, David [Department of Radiation Oncology, Centre Hospitalier de l' Universite de Montreal, Montreal, Quebec (Canada); Haas, Rick L.M. [Department of Radiotherapy, Netherlands Cancer Institute, Amsterdam (Netherlands); Catton, Charles N. [Department of Radiation Oncology, Princess Margaret Cancer Centre, Toronto, Ontario (Canada); Indelicato, Daniel J. [Department of Radiation Oncology, University of Florida Medical Center, Jacksonville, Florida (United States); Olsen, Jeffrey R. [Department of Radiation Oncology, Washington University, St. Louis, Missouri (United States); Deville, Curtiland [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania (United States); Chen, Yen-Lin [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Finkelstein, Steven E. [Translational Research Consortium, 21st Century Oncology, Scottsdale, Arizona (United States); DeLaney, Thomas F. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Wang, Dian [Department of Radiation Oncology, Rush University Medical Center, Chicago, Illinois (United States)

    2015-08-01

    Purpose: The purpose of this study was to evaluate the variability in target volume and organ at risk (OAR) contour delineation for retroperitoneal sarcoma (RPS) among 12 sarcoma radiation oncologists. Methods and Materials: Radiation planning computed tomography (CT) scans for 2 cases of RPS were distributed among 12 sarcoma radiation oncologists with instructions for contouring gross tumor volume (GTV), clinical target volume (CTV), high-risk CTV (HR CTV: area judged to be at high risk of resulting in positive margins after resection), and OARs: bowel bag, small bowel, colon, stomach, and duodenum. Analysis of contour agreement was performed using the simultaneous truth and performance level estimation (STAPLE) algorithm and kappa statistics. Results: Ten radiation oncologists contoured both RPS cases, 1 contoured only RPS1, and 1 contoured only RPS2 such that each case was contoured by 11 radiation oncologists. The first case (RPS 1) was a patient with a de-differentiated (DD) liposarcoma (LPS) with a predominant well-differentiated (WD) component, and the second case (RPS 2) was a patient with DD LPS made up almost entirely of a DD component. Contouring agreement for GTV and CTV contours was high. However, the agreement for HR CTVs was only moderate. For OARs, agreement for stomach, bowel bag, small bowel, and colon was high, but agreement for duodenum (distorted by tumor in one of these cases) was fair to moderate. Conclusions: For preoperative treatment of RPS, sarcoma radiation oncologists contoured GTV, CTV, and most OARs with a high level of agreement. HR CTV contours were more variable. Further clarification of this volume with the help of sarcoma surgical oncologists is necessary to reach consensus. More attention to delineation of the duodenum is also needed.

  5. Can Images Obtained With High Field Strength Magnetic Resonance Imaging Reduce Contouring Variability of the Prostate?

    International Nuclear Information System (INIS)

    Usmani, Nawaid; Sloboda, Ron; Kamal, Wafa; Ghosh, Sunita; Pervez, Nadeem; Pedersen, John; Yee, Don; Danielson, Brita; Murtha, Albert; Amanie, John; Monajemi, Tara

    2011-01-01

    Purpose: The objective of this study is to determine whether there is less contouring variability of the prostate using higher-strength magnetic resonance images (MRI) compared with standard MRI and computed tomography (CT). Methods and Materials: Forty patients treated with prostate brachytherapy were accrued to a prospective study that included the acquisition of 1.5-T MR and CT images at specified time points. A subset of 10 patients had additional 3.0-T MR images acquired at the same time as their 1.5-T MR scans. Images from each of these patients were contoured by 5 radiation oncologists, with a random subset of patients repeated to quantify intraobserver contouring variability. To minimize bias in contouring the prostate, the image sets were placed in folders in a random order with all identifiers removed from the images. Results: Although there was less interobserver contouring variability in the overall prostate volumes in 1.5-T MRI compared with 3.0-T MRI (p < 0.01), there was no significant differences in contouring variability in the different regions of the prostate between 1.5-T MRI and 3.0-T MRI. MRI demonstrated significantly less interobserver contouring variability in both 1.5-T and 3.0-T compared with CT in overall prostate volumes (p < 0.01, p = 0.01), with the greatest benefits being appreciated in the base of the prostate. Overall, there was less intraobserver contouring variability than interobserver contouring variability for all of the measurements analyzed. Conclusions: Use of 3.0-T MRI does not demonstrate a significant improvement in contouring variability compared with 1.5-T MRI, although both magnetic strengths demonstrated less contouring variability compared with CT.

  6. Retroperitoneal Sarcoma Target Volume and Organ at Risk Contour Delineation Agreement Among NRG Sarcoma Radiation Oncologists

    International Nuclear Information System (INIS)

    Baldini, Elizabeth H.; Abrams, Ross A.; Bosch, Walter; Roberge, David; Haas, Rick L.M.; Catton, Charles N.; Indelicato, Daniel J.; Olsen, Jeffrey R.; Deville, Curtiland; Chen, Yen-Lin; Finkelstein, Steven E.; DeLaney, Thomas F.; Wang, Dian

    2015-01-01

    Purpose: The purpose of this study was to evaluate the variability in target volume and organ at risk (OAR) contour delineation for retroperitoneal sarcoma (RPS) among 12 sarcoma radiation oncologists. Methods and Materials: Radiation planning computed tomography (CT) scans for 2 cases of RPS were distributed among 12 sarcoma radiation oncologists with instructions for contouring gross tumor volume (GTV), clinical target volume (CTV), high-risk CTV (HR CTV: area judged to be at high risk of resulting in positive margins after resection), and OARs: bowel bag, small bowel, colon, stomach, and duodenum. Analysis of contour agreement was performed using the simultaneous truth and performance level estimation (STAPLE) algorithm and kappa statistics. Results: Ten radiation oncologists contoured both RPS cases, 1 contoured only RPS1, and 1 contoured only RPS2 such that each case was contoured by 11 radiation oncologists. The first case (RPS 1) was a patient with a de-differentiated (DD) liposarcoma (LPS) with a predominant well-differentiated (WD) component, and the second case (RPS 2) was a patient with DD LPS made up almost entirely of a DD component. Contouring agreement for GTV and CTV contours was high. However, the agreement for HR CTVs was only moderate. For OARs, agreement for stomach, bowel bag, small bowel, and colon was high, but agreement for duodenum (distorted by tumor in one of these cases) was fair to moderate. Conclusions: For preoperative treatment of RPS, sarcoma radiation oncologists contoured GTV, CTV, and most OARs with a high level of agreement. HR CTV contours were more variable. Further clarification of this volume with the help of sarcoma surgical oncologists is necessary to reach consensus. More attention to delineation of the duodenum is also needed

  7. Poster - Thur Eve - 65: Optimization of an automatic image contouring system for radiation therapy.

    Science.gov (United States)

    Hamilton, T; Nedialkov, N; Wierzbicki, M

    2012-07-01

    Intensity modulated radiation therapy (IMRT) is an advanced technique used to concentrate the prescribed dose in the tumour while minimizing exposure to healthy tissues. Success in IMRT is greatly dependent upon the localization of the target volume and normal tissue, thus accurate contouring is crucial. In this paper, we describe an automated atlas-based image contouring system and our approach for improving the system by performing a full-scale optimization of registration parameters using high-performance computing. To achieve this, we use manually pre-contoured CT images of ten head and neck patients. For any parameter set, each patient data is registered with the remaining patients. Accuracy of the resulting contours is determined automatically by comparing their overlap with manually defined targets using Dice's similarity coefficient (DSC). This allows us to compare all permutations of the image registration parameter sets and input data to investigate their impact on final contour accuracy. Investigating the parameter space required 27,000 image registrations and 216,000 DSC computations. To perform these registrations we introduced a large cluster of high-performance computers and developed a parallel testing harness. The metrics collected from the tests show a wide range of performance, indicating that parameter selection is crucial in our contouring system. By selecting an optimized parameter set, we increased the mean overlap of the automatically contoured regions of interest by 50% and reduced registration time by 50% compared to the original parameters. Our findings illustrate that full-scale optimization is an effective method for improving the performance of the automated image contouring system. © 2012 American Association of Physicists in Medicine.

  8. Bayesian Exponential Smoothing.

    OpenAIRE

    Forbes, C.S.; Snyder, R.D.; Shami, R.S.

    2000-01-01

    In this paper, a Bayesian version of the exponential smoothing method of forecasting is proposed. The approach is based on a state space model containing only a single source of error for each time interval. This model allows us to improve current practices surrounding exponential smoothing by providing both point predictions and measures of the uncertainty surrounding them.

  9. A comparative study of traditional lecture methods and interactive lecture methods in introductory geology courses for non-science majors at the college level

    Science.gov (United States)

    Hundley, Stacey A.

    In recent years there has been a national call for reform in undergraduate science education. The goal of this reform movement in science education is to develop ways to improve undergraduate student learning with an emphasis on developing more effective teaching practices. Introductory science courses at the college level are generally taught using a traditional lecture format. Recent studies have shown incorporating active learning strategies within the traditional lecture classroom has positive effects on student outcomes. This study focuses on incorporating interactive teaching methods into the traditional lecture classroom to enhance student learning for non-science majors enrolled in introductory geology courses at a private university. Students' experience and instructional preferences regarding introductory geology courses were identified from survey data analysis. The information gained from responses to the questionnaire was utilized to develop an interactive lecture introductory geology course for non-science majors. Student outcomes were examined in introductory geology courses based on two teaching methods: interactive lecture and traditional lecture. There were no significant statistical differences between the groups based on the student outcomes and teaching methods. Incorporating interactive lecture methods did not statistically improve student outcomes when compared to traditional lecture teaching methods. However, the responses to the survey revealed students have a preference for introductory geology courses taught with lecture and instructor-led discussions and students prefer to work independently or in small groups. The results of this study are useful to individuals who teach introductory geology courses and individuals who teach introductory science courses for non-science majors at the college level.

  10. Principle and realization of segmenting contour series algorithm in reverse engineering based on X-ray computerized tomography

    International Nuclear Information System (INIS)

    Wang Yanfang; Liu Li; Yan Yonglian; Shan Baoci; Tang Xiaowei

    2007-01-01

    A new algorithm of segmenting contour series of images is presented, which can achieve three dimension reconstruction with parametric recognition in Reverse Engineering based on X-ray CT. First, in order to get the nested relationship between contours, a method of a certain angle ray is used. Second, for realizing the contour location in one slice, another approach is presented to generate the contour tree by scanning the relevant vector only once. Last, a judge algorithm is put forward to accomplish the contour match between slices by adopting the qualitative and quantitative properties. The example shows that this algorithm can segment contour series of CT parts rapidly and precisely. (authors)

  11. Lecture on Female Masturbation Harassed Him, Male Student Says.

    Science.gov (United States)

    Wilson, Robin

    1995-01-01

    A male student in a California State University-Sacramento psychology lecture on female masturbation has filed a sexual harassment complaint, claiming the lecture violated institutional policy by creating an intimidating, hostile, and offensive learning environment. He felt the lecture was inappropriately graphic and political in intent. (MSE)

  12. Making of Evalution’s Information System of Lecturer's Lecture and Major’s Service-Based Web in PTIK Major FKIP UNS

    Directory of Open Access Journals (Sweden)

    Irma Nuur Rochmah

    2017-12-01

    Full Text Available The quality of education of a study program can be measured from the level of customer satisfaction with the existing service. In accordance with ISO 9001: 2008, an organization should measure and obtain information related to customers and customers. Measurements and information that can be done survey data on customer satisfaction. From this survey data, Informatics and Computer Education Study Program can follow which aspect need improvement for program quality. One way to get survey data by doing the evaluation. In the Study Program of Informatics and Computer Engineering, evaluation using application form online form. The study program does not yet have its own evaluation information system. Therefore, the purpose of this research is to produce information technology and pelaynaan web-based program in the Study Program (Prodi Educational Engineering and Computer Informatics and to determine the level of the feasibility of information. In this study used research and development model with the first phase of the preliminary study, the second stage of product development and the last stage. At the product development stage is done by using software development model. From the stages of inputs obtained from the assessment of students on lecturers' lectures and prodi services in Education Program Informatics and Computer Engineering. The result of evaluation of lecturers' lectures and prodi services by selected students with their rena as output that can be seen by lecturer and admin. A system that can be used to help the services that have been given to the students, both in lecturers' lectures and prodi services. The results of this study, first, has created information and web-based programming services in Informatics and Computer Engineering Education Program, FKIP, UNS. Second, the feasibility of information and product and service development, Informatics and Computer Engineering Education Study Program, FKIP, UNS conducted by expert

  13. Closed contour fractal dimension estimation by the Fourier transform

    International Nuclear Information System (INIS)

    Florindo, J.B.; Bruno, O.M.

    2011-01-01

    Highlights: → A novel fractal dimension concept, based on Fourier spectrum, is proposed. → Computationally simple. Computational time smaller than conventional fractal methods. → Results are closer to Hausdorff-Besicovitch than conventional methods. → The method is more accurate and robustness to geometric operations and noise addition. - Abstract: This work proposes a novel technique for the numerical calculus of the fractal dimension of fractal objects which can be represented as a closed contour. The proposed method maps the fractal contour onto a complex signal and calculates its fractal dimension using the Fourier transform. The Fourier power spectrum is obtained and an exponential relation is verified between the power and the frequency. From the parameter (exponent) of the relation, is obtained the fractal dimension. The method is compared to other classical fractal dimension estimation methods in the literature, e.g., Bouligand-Minkowski, box-counting and classical Fourier. The comparison is achieved by the calculus of the fractal dimension of fractal contours whose dimensions are well-known analytically. The results showed the high precision and robustness of the proposed technique.

  14. Heavy ion scattering in 3D TDHF. [Isodensity contours

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, M.S.

    1977-09-01

    Results of three-dimensional (3D) time-dependent Hartree--Fock (TDHF) calculations are presented. The assumptions used in the calculations are summarized. The first reaction considered is /sup 16/O + /sup 16/O at 105 MeV (lab); isodensity contours integrated perpendicular to the reaction plane are shown for several impact parameters as a function of time. Trajectories are also shown, and the kinetics of the reaction is discussed; several other energies were also examined. Most of the deeply inelastic scattering seems to come from small impact parameters. Density contours and trajectories are next shown for /sup 40/Ca + /sup 40/Ca at 278 MeV (lab). Finally, density contours are shown for asymmetric systems: /sup 4/He + /sup 16/O at l = 5 h-bar and 50 MeV (lab) and /sup 16/O + /sup 40/Ca at l = 20, 40, 60, 80 h-bar and 315 MeV (lab). The light fragment seems to maintain the same average number of nucleons with which it started. 25 figures. (RWR)

  15. Lectures on strings and dualities

    International Nuclear Information System (INIS)

    Vafa, C.

    1997-01-01

    In this set of lectures I review recent developments in string theory emphasizing their non-perturbative aspects and their recently discovered duality symmetries. The goal of the lectures is to make the recent exciting developments in string theory accessible to those with no previous background in string theory who wish to join the research effort in this area. Topics covered include a brief review of string theory, its compactifications, solitons and D-branes, black hole entropy and wed of string dualities. (author)

  16. Contour forming of metals by laser peening

    Science.gov (United States)

    Hackel, Lloyd; Harris, Fritz

    2002-01-01

    A method and apparatus are provided for forming shapes and contours in metal sections by generating laser induced compressive stress on the surface of the metal workpiece. The laser process can generate deep compressive stresses to shape even thick components without inducing unwanted tensile stress at the metal surface. The precision of the laser-induced stress enables exact prediction and subsequent contouring of parts. A light beam of 10 to 100 J/pulse is imaged to create an energy fluence of 60 to 200 J/cm.sup.2 on an absorptive layer applied over a metal surface. A tamping layer of water is flowed over the absorptive layer. The absorption of laser light causes a plasma to form and consequently creates a shock wave that induces a deep residual compressive stress into the metal. The metal responds to this residual stress by bending.

  17. Jubilee Lecture

    Indian Academy of Sciences (India)

    2017-08-07

    Aug 7, 2017 ... E up V As a \\ Nipio with students, teachers and researchers in India. Nsp1 Nup8C Nup57. Nup57. Nup145N. High tea will be served after the lecture. For details contact: M. Ananth, Molecular Biophysics Unit, Indian Institute of Science. Email: ananthmuthiah Ogmail.com/ananthmOmbu..iscernet.in Mob. 984 ...

  18. Anti-smooth muscle antibody

    Science.gov (United States)

    ... gov/ency/article/003531.htm Anti-smooth muscle antibody To use the sharing features on this page, please enable JavaScript. Anti-smooth muscle antibody is a blood test that detects the presence ...

  19. Smooth functors vs. differential forms

    NARCIS (Netherlands)

    Schreiber, U.; Waldorf, K.

    2011-01-01

    We establish a relation between smooth 2-functors defined on the path 2-groupoid of a smooth manifold and differential forms on this manifold. This relation can be understood as a part of a dictionary between fundamental notions from category theory and differential geometry. We show that smooth

  20. Transference of Fermi Contour Anisotropy to Composite Fermions.

    Science.gov (United States)

    Jo, Insun; Rosales, K A Villegas; Mueed, M A; Pfeiffer, L N; West, K W; Baldwin, K W; Winkler, R; Padmanabhan, Medini; Shayegan, M

    2017-07-07

    There has been a surge of recent interest in the role of anisotropy in interaction-induced phenomena in two-dimensional (2D) charged carrier systems. A fundamental question is how an anisotropy in the energy-band structure of the carriers at zero magnetic field affects the properties of the interacting particles at high fields, in particular of the composite fermions (CFs) and the fractional quantum Hall states (FQHSs). We demonstrate here tunable anisotropy for holes and hole-flux CFs confined to GaAs quantum wells, via applying in situ in-plane strain and measuring their Fermi wave vector anisotropy through commensurability oscillations. For strains on the order of 10^{-4} we observe significant deformations of the shapes of the Fermi contours for both holes and CFs. The measured Fermi contour anisotropy for CFs at high magnetic field (α_{CF}) is less than the anisotropy of their low-field hole (fermion) counterparts (α_{F}), and closely follows the relation α_{CF}=sqrt[α_{F}]. The energy gap measured for the ν=2/3 FQHS, on the other hand, is nearly unaffected by the Fermi contour anisotropy up to α_{F}∼3.3, the highest anisotropy achieved in our experiments.

  1. Contributions of contour frequency, amplitude, and luminance to the watercolor effect estimated by conjoint measurement.

    Science.gov (United States)

    Gerardin, Peggy; Devinck, Frédéric; Dojat, Michel; Knoblauch, Kenneth

    2014-04-10

    The watercolor effect is a long-range, assimilative, filling-in phenomenon induced by a pair of distant, wavy contours of different chromaticities. Here, we measured joint influences of the contour frequency and amplitude and the luminance of the interior contour on the strength of the effect. Contour pairs, each enclosing a circular region, were presented with two of the dimensions varying independently across trials (luminance/frequency, luminance/amplitude, frequency/amplitude) in a conjoint measurement paradigm (Luce & Tukey, 1964). In each trial, observers judged which of the stimuli evoked the strongest fill-in color. Control stimuli were identical except that the contours were intertwined and generated little filling-in. Perceptual scales were estimated by a maximum likelihood method (Ho, Landy, & Maloney, 2008). An additive model accounted for the joint contributions of any pair of dimensions. As shown previously using difference scaling (Devinck & Knoblauch, 2012), the strength increases with luminance of the interior contour. The strength of the phenomenon was nearly independent of the amplitude of modulation of the contour but increased with its frequency up to an asymptotic level. On average, the strength of the effect was similar along a given dimension regardless of the other dimension with which it was paired, demonstrating consistency of the underlying estimated perceptual scales.

  2. A fully automated contour detection algorithm the preliminary step for scatter and attenuation compensation in SPECT

    International Nuclear Information System (INIS)

    Younes, R.B.; Mas, J.; Bidet, R.

    1988-01-01

    Contour detection is an important step in information extraction from nuclear medicine images. In order to perform accurate quantitative studies in single photon emission computed tomography (SPECT) a new procedure is described which can rapidly derive the best fit contour of an attenuated medium. Some authors evaluate the influence of the detected contour on the reconstructed images with various attenuation correction techniques. Most of the methods are strongly affected by inaccurately detected contours. This approach uses the Compton window to redetermine the convex contour: It seems to be simpler and more practical in clinical SPECT studies. The main advantages of this procedure are the high speed of computation, the accuracy of the contour found and the programme's automation. Results obtained using computer simulated and real phantoms or clinical studies demonstrate the reliability of the present algorithm. (orig.)

  3. 45 CFR 73.735-706 - Teaching, lecturing, and speechmaking.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Teaching, lecturing, and speechmaking. 73.735-706... OF CONDUCT Outside Activities § 73.735-706 Teaching, lecturing, and speechmaking. (a) Employees are encouraged to engage in teaching and lecturing activities which are not part of their official duties when...

  4. Common Visual Preference for Curved Contours in Humans and Great Apes.

    Science.gov (United States)

    Munar, Enric; Gómez-Puerto, Gerardo; Call, Josep; Nadal, Marcos

    2015-01-01

    Among the visual preferences that guide many everyday activities and decisions, from consumer choices to social judgment, preference for curved over sharp-angled contours is commonly thought to have played an adaptive role throughout human evolution, favoring the avoidance of potentially harmful objects. However, because nonhuman primates also exhibit preferences for certain visual qualities, it is conceivable that humans' preference for curved contours is grounded on perceptual and cognitive mechanisms shared with extant nonhuman primate species. Here we aimed to determine whether nonhuman great apes and humans share a visual preference for curved over sharp-angled contours using a 2-alternative forced choice experimental paradigm under comparable conditions. Our results revealed that the human group and the great ape group indeed share a common preference for curved over sharp-angled contours, but that they differ in the manner and magnitude with which this preference is expressed behaviorally. These results suggest that humans' visual preference for curved objects evolved from earlier primate species' visual preferences, and that during this process it became stronger, but also more susceptible to the influence of higher cognitive processes and preference for other visual features.

  5. Features of using multimedia technologies at lecturing programming

    Directory of Open Access Journals (Sweden)

    G. S. Ivanova

    2014-01-01

    Full Text Available The subject of study of this paper is multimedia capabilities, which are used for lectures on programming for undergraduate students to learn Computer Science and Engineering.The objective is to analyze the factors affecting the efficiency of lectures on programming, readable using multimedia, identifying the advantages and disadvantages of using presentations and process of creating and debugging programs in software environments demonstration, and to make recommendations on the use of illustrative material aimed at improving student's handout with the knowledge readable material.Scientific novelty of the material is to identify and analyze the factors influencing the effectiveness of teaching programming using multimedia as well as to make recommendations on the creation of illustrative material in the form of lecture presentations, analyse the negative side effects of presentations and opportunities to address them.It is stated that even at the initial stage of teaching in programming the amount of learning material and associated details in their records to which student's attention should be drawn, commensurate with the restrictions of psycho physiological capabilities defined for modern undergraduate students to remember and learn. The conclusion about expediency to improve lectures efficiency through the use of multimedia equipment capabilities is made.The types of illustrative material used in lectures on programming are listed and named, examples of illustrative material for presentation slides are analyzed. The positive results of the process of program creating, debugging and running directly in the programming environment during the lecture are underlined .As the merits of the multimedia-based lectures are marked a significant reduction of time to be required for material presentation ( from 10 to 30 % and the structured and with no errors in the program texts of lectures available for students. Negative effects of the multimedia

  6. Luminance contours can gate afterimage colors and "real" colors.

    Science.gov (United States)

    Anstis, Stuart; Vergeer, Mark; Van Lier, Rob

    2012-09-06

    It has long been known that colored images may elicit afterimages in complementary colors. We have already shown (Van Lier, Vergeer, & Anstis, 2009) that one and the same adapting image may result in different afterimage colors, depending on the test contours presented after the colored image. The color of the afterimage depends on two adapting colors, those both inside and outside the test. Here, we further explore this phenomenon and show that the color-contour interactions shown for afterimage colors also occur for "real" colors. We argue that similar mechanisms apply for both types of stimulation.

  7. Academic Training: Summer Student Lecture Programme

    CERN Multimedia

    2004-01-01

    Main Auditorium, bldg. 500 DATE TIME LECTURER TITLE Monday 19 July 09:15 - 10:00 A. PICH (IFIC) The Standard Model (1/8) 10:15 - 11:00 O. ULLALAND (CERN) Detectors (2/5) 11:15 - 12:00 O. ULLALAND (CERN) Detectors (3/5) DATE TIME LECTURER TITLE Tuesday 20 July 09:15 - 10:00 A. PICH (IFIC) The Standard Model (2/8) 10:15 - 11:00 O. ULLALAND (CERN) Detectors (4/5) 11:15 - 12:00 O. ULLALAND (CERN) A. PICH (IFIC) Discussion Session DATE TIME LECTURER TITLE Wednesday 21 July 09:15 - 10:00 A. PICH (IFIC) The Standard Model (3/8) 10:15 - 11:00 A. PICH (IFIC) The Standard Model (4/8) 11:15 - 12:00 O. ULLALAND (CERN) Detectors (5/5) 14:00 - 15:00 R. BRUN (CERN) ROOT: Introduction and Demonstration DATE TIME LECTURER TITLE Thursday 22 July 09:15 - 10:00 A. PICH (IFIC) The Standard Model (5/8) 10:15 - 11:00 C. De La Taille (Laboratoire de l'Accélérateur Linéaire) Introduction to Electronics (1/3) 11:15 - 12:00 A. PICH (IFIC) C. De La Taille (Laboratoi...

  8. On a program manifold’s stability of one contour automatic control systems

    Directory of Open Access Journals (Sweden)

    Zumatov S. S.

    2017-12-01

    Full Text Available Methodology of analysis of stability is expounded to the one contour systems automatic control feedback in the presence of non-linearities. The methodology is based on the use of the simplest mathematical models of the nonlinear controllable systems. Stability of program manifolds of one contour automatic control systems is investigated. The sufficient conditions of program manifold’s absolute stability of one contour automatic control systems are obtained. The Hurwitz’s angle of absolute stability was determined. The sufficient conditions of program manifold’s absolute stability of control systems by the course of plane in the mode of autopilot are obtained by means Lyapunov’s second method.

  9. Smoothness in Binomial Edge Ideals

    Directory of Open Access Journals (Sweden)

    Hamid Damadi

    2016-06-01

    Full Text Available In this paper we study some geometric properties of the algebraic set associated to the binomial edge ideal of a graph. We study the singularity and smoothness of the algebraic set associated to the binomial edge ideal of a graph. Some of these algebraic sets are irreducible and some of them are reducible. If every irreducible component of the algebraic set is smooth we call the graph an edge smooth graph, otherwise it is called an edge singular graph. We show that complete graphs are edge smooth and introduce two conditions such that the graph G is edge singular if and only if it satisfies these conditions. Then, it is shown that cycles and most of trees are edge singular. In addition, it is proved that complete bipartite graphs are edge smooth.

  10. Tonal Language Background and Detecting Pitch Contour in Spoken and Musical Items

    Science.gov (United States)

    Stevens, Catherine J.; Keller, Peter E.; Tyler, Michael D.

    2013-01-01

    An experiment investigated the effect of tonal language background on discrimination of pitch contour in short spoken and musical items. It was hypothesized that extensive exposure to a tonal language attunes perception of pitch contour. Accuracy and reaction times of adult participants from tonal (Thai) and non-tonal (Australian English) language…

  11. "But They Won't Come to Lectures..." The Impact of Audio Recorded Lectures on Student Experience and Attendance

    Science.gov (United States)

    Larkin, Helen E.

    2010-01-01

    The move to increasingly flexible platforms for student learning and experience through provision of online lecture recordings is often interpreted by educators as students viewing attendance at lectures as optional. The trend toward the use of this technology is often met with resistance from some academic staff who argue that student attendance…

  12. SU-C-BRA-03: An Automated and Quick Contour Errordetection for Auto Segmentation in Online Adaptive Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, J; Ates, O; Li, X [Medical College of Wisconsin, Milwaukee, WI (United States)

    2016-06-15

    Purpose: To develop a tool that can quickly and automatically assess contour quality generated from auto segmentation during online adaptive replanning. Methods: Due to the strict time requirement of online replanning and lack of ‘ground truth’ contours in daily images, our method starts with assessing image registration accuracy focusing on the surface of the organ in question. Several metrics tightly related to registration accuracy including Jacobian maps, contours shell deformation, and voxel-based root mean square (RMS) analysis were computed. To identify correct contours, additional metrics and an adaptive decision tree are introduced. To approve in principle, tests were performed with CT sets, planned and daily CTs acquired using a CT-on-rails during routine CT-guided RT delivery for 20 prostate cancer patients. The contours generated on daily CTs using an auto-segmentation tool (ADMIRE, Elekta, MIM) based on deformable image registration of the planning CT and daily CT were tested. Results: The deformed contours of 20 patients with total of 60 structures were manually checked as baselines. The incorrect rate of total contours is 49%. To evaluate the quality of local deformation, the Jacobian determinant (1.047±0.045) on contours has been analyzed. In an analysis of rectum contour shell deformed, the higher rate (0.41) of error contours detection was obtained compared to 0.32 with manual check. All automated detections took less than 5 seconds. Conclusion: The proposed method can effectively detect contour errors in micro and macro scope by evaluating multiple deformable registration metrics in a parallel computing process. Future work will focus on improving practicability and optimizing calculation algorithms and metric selection.

  13. SU-C-BRA-03: An Automated and Quick Contour Errordetection for Auto Segmentation in Online Adaptive Radiotherapy

    International Nuclear Information System (INIS)

    Zhang, J; Ates, O; Li, X

    2016-01-01

    Purpose: To develop a tool that can quickly and automatically assess contour quality generated from auto segmentation during online adaptive replanning. Methods: Due to the strict time requirement of online replanning and lack of ‘ground truth’ contours in daily images, our method starts with assessing image registration accuracy focusing on the surface of the organ in question. Several metrics tightly related to registration accuracy including Jacobian maps, contours shell deformation, and voxel-based root mean square (RMS) analysis were computed. To identify correct contours, additional metrics and an adaptive decision tree are introduced. To approve in principle, tests were performed with CT sets, planned and daily CTs acquired using a CT-on-rails during routine CT-guided RT delivery for 20 prostate cancer patients. The contours generated on daily CTs using an auto-segmentation tool (ADMIRE, Elekta, MIM) based on deformable image registration of the planning CT and daily CT were tested. Results: The deformed contours of 20 patients with total of 60 structures were manually checked as baselines. The incorrect rate of total contours is 49%. To evaluate the quality of local deformation, the Jacobian determinant (1.047±0.045) on contours has been analyzed. In an analysis of rectum contour shell deformed, the higher rate (0.41) of error contours detection was obtained compared to 0.32 with manual check. All automated detections took less than 5 seconds. Conclusion: The proposed method can effectively detect contour errors in micro and macro scope by evaluating multiple deformable registration metrics in a parallel computing process. Future work will focus on improving practicability and optimizing calculation algorithms and metric selection.

  14. Comparing subjective contours for Kanizsa squares and linear edge alignments ('New York Titanic' figures).

    Science.gov (United States)

    Gillam, Barbara; Marlow, Phillip J

    2014-01-01

    One current view is that subjective contours may involve high-level detection of a salient shape with back propagation to early visual areas where small receptive fields allow for scrutiny of relevant details. This idea applies to Kanizsa-type figures. However, Gillam and Chan (2002 Psychological Science, 13, 279-282) using figures based on Gillam's graphic 'New York Titanic' (Gillam, 1997 Thresholds: Limits of perception. New York: Arts Magazine) showed that strong subjective contours can be seen along the linearly aligned edges of a set of shapes if occlusion cues of 'extrinsic edge' and 'entropy contrast' are strong. Here we compared ratings of the strength of subjective contours along linear alignments with those seen in Kanizsa figures. The strongest subjective contour for a single set of linearly aligned shapes was similar in strength to the edges of a Kanizsa square (controlling for support ratio) despite the lack of a salient region. The addition of a second set of linearly aligned inducers consistent with a common surface increased subjective-contour strength, as did having four rather than two 'pacmen' in the Kanizsa figure, indicating a role for surface support. We argue that linear subjective contours allow for the investigation of certain occlusion cues and the interactions between them that are not easily explored with Kanizsa figures.

  15. Students' Perception of Live Lectures' Inherent Disadvantages

    Science.gov (United States)

    Petrovic, Juraj; Pale, Predrag

    2015-01-01

    This paper aims to provide insight into various properties of live lectures from the perspective of sophomore engineering students. In an anonymous online survey conducted at the Faculty of Electrical Engineering and Computing, University of Zagreb, we investigated students' opinions regarding lecture attendance, inherent disadvantages of live…

  16. Enhancing the Lecture: Revitalizing the Traditional Format.

    Science.gov (United States)

    Bonwell, Charles C.

    1996-01-01

    The traditional lecture format of college courses can be enhanced by including active learning designed to further course goals of learning knowledge, developing skills, or fostering attitudes. Techniques suggested include using pauses, short writing periods, think-pair-share activities, formative quizzes, lecture summaries, and several assessment…

  17. The Use of Blog as Supporting Media for Competence of Lecturer

    Directory of Open Access Journals (Sweden)

    Anne Ratnasari

    2015-12-01

    Full Text Available Competence is one of the important parts of brand study, while brand it is a part of the marketing that has an important position by selling product and services. So brand itself not only for the company, it can also manage individual brands, public figures, and lecturer. This research aimed for determining the use of blogs as a medium to support the competence of lecturers from the aspect trustworthiness, commitment, ability to develop themselves practicing a profession, and a limiting factor in building the competence of lecturers. This research uses a qualitative approach with a single case study through observation, interviews, focus group discussions, and literature. The study found that lecturer use blogs to share lectures, ideas about contemporary events, and upload Islamic articles. Lecturer assessed reliably, because the lecturer writing on a blog is the result of his work, and a lot of consultation requests from various circles. The lecturer is committed to making a change for the better in every way when communicating via blog to maintain conformity with the words of his behavior, and lecturer has the ability to develop themselves in their profession as a lecturer, that gives him the strength to continue working.

  18. Maintaining Contour Trees of Dynamic Terrains

    DEFF Research Database (Denmark)

    Agarwal, Pankaj K.; Arge, Lars; Mølhave, Thomas

    We consider maintaining the contour tree T of a piecewise-linear triangulation M that is the graph of a time varying height function h:R2→R. We carefully describe the combinatorial change in T that happen as h varies over time and how these changes relate to topological changes in M. We present a...

  19. Recently Published Lectures and Tutorials for ATLAS

    CERN Multimedia

    J. Herr

    2006-01-01

    As reported in the September 2004 ATLAS eNews, the Web Lecture Archive Project, a collaboration between the University of Michigan and CERN, has developed a synchronized system for recording and publishing educational multimedia presentations, using the Web as medium. The current system, including future developments for the project and the field in general, was recently presented at the CHEP 2006 conference in Mumbai, India. The relevant presentations and papers can be found here: The Web Lecture Archive Project A Web Lecture Capture System with Robotic Speaker Tracking This year, the University of Michigan team has been asked to record and publish all ATLAS Plenary sessions, as well as a large number of Physics and Computing tutorials. A significant amount of this material has already been published and can be accessed via the links below. All lectures can be viewed on any major platform with any common internet browser, either via streaming or local download (for limited bandwidth). Please enjoy the l...

  20. Recently Published Lectures and Tutorials for ATLAS

    CERN Multimedia

    Goldfarb, S.

    2006-01-01

    As reported in the September 2004 ATLAS eNews, the Web Lecture Archive Project, WLAP, a collaboration between the University of Michigan and CERN, has developed a synchronized system for recording and publishing educational multimedia presentations, using the Web as medium. The current system, including future developments for the project and the field in general, was recently presented at the CHEP 2006 conference in Mumbai, India. The relevant presentations and papers can be found here: The Web Lecture Archive Project. A Web Lecture Capture System with Robotic Speaker Tracking This year, the University of Michigan team has been asked to record and publish all ATLAS Plenary sessions, as well as a large number of Physics and Computing tutorials. A significant amount of this material has already been published and can be accessed via the links below. All lectures can be viewed on any major platform with any common internet browser, either via streaming or local download (for limited bandwidth). Please e...

  1. Dynamic e-learning modules for student lecture preparation

    Directory of Open Access Journals (Sweden)

    Timothy McIntyre

    2018-03-01

    Full Text Available We have developed and demonstrated the effectiveness of a set of online interactive learning modules to accompany physics courses at first- and second-year university levels. Students access the modules prior to attending lectures to familiarize themselves with content which is then discussed and reaffirmed in class. Student surveys and access data show that students were much more likely to use material presented in this form, rather than a textbook, when preparing for lectures given in an active learning format. The students found that interactive simulations, videos of problem-solving approaches prepared by course staff, and quick-check immediate feedback questions were all useful tools for lecture preparation–none of which are available when using a traditional textbook for lecture preparation.

  2. Computer-aided diagnosis of pulmonary nodules on CT scans: Segmentation and classification using 3D active contours

    International Nuclear Information System (INIS)

    Way, Ted W.; Hadjiiski, Lubomir M.; Sahiner, Berkman; Chan, H.-P.; Cascade, Philip N.; Kazerooni, Ella A.; Bogot, Naama; Zhou Chuan

    2006-01-01

    We are developing a computer-aided diagnosis (CAD) system to classify malignant and benign lung nodules found on CT scans. A fully automated system was designed to segment the nodule from its surrounding structured background in a local volume of interest (VOI) and to extract image features for classification. Image segmentation was performed with a three-dimensional (3D) active contour (AC) method. A data set of 96 lung nodules (44 malignant, 52 benign) from 58 patients was used in this study. The 3D AC model is based on two-dimensional AC with the addition of three new energy components to take advantage of 3D information: (1) 3D gradient, which guides the active contour to seek the object surface (2) 3D curvature, which imposes a smoothness constraint in the z direction, and (3) mask energy, which penalizes contours that grow beyond the pleura or thoracic wall. The search for the best energy weights in the 3D AC model was guided by a simplex optimization method. Morphological and gray-level features were extracted from the segmented nodule. The rubber band straightening transform (RBST) was applied to the shell of voxels surrounding the nodule. Texture features based on run-length statistics were extracted from the RBST image. A linear discriminant analysis classifier with stepwise feature selection was designed using a second simplex optimization to select the most effective features. Leave-one-case-out resampling was used to train and test the CAD system. The system achieved a test area under the receiver operating characteristic curve (A z ) of 0.83±0.04. Our preliminary results indicate that use of the 3D AC model and the 3D texture features surrounding the nodule is a promising approach to the segmentation and classification of lung nodules with CAD. The segmentation performance of the 3D AC model trained with our data set was evaluated with 23 nodules available in the Lung Image Database Consortium (LIDC). The lung nodule volumes segmented by the 3D AC

  3. Lectures in the history of mathematics

    CERN Document Server

    Bos, Henk J M

    1993-01-01

    "[These lectures] are about themes of the history of mathematics which, for various reasons, are dear to me. The early differential and integral calculus, the work of Christiaan Huygens, and the concept of construction in seventeenth- and eighteenth-century mathematics are the three themes around which much of my research has concentrated and which continue to fascinate me by the insights they offer in the development of that special human activity called mathematics." -from the Introduction This volume contains eleven lectures ranging over a variety of topics in the history of mathematics. The lectures, presented between 1970 and 1987, were delivered in a variety of venues and appeared only in less accessible publications. Those who teach mathematics, as well as mathematics historians, will appreciate this insightful, wide-ranging book.

  4. Pelvic Normal Tissue Contouring Guidelines for Radiation Therapy: A Radiation Therapy Oncology Group Consensus Panel Atlas

    Energy Technology Data Exchange (ETDEWEB)

    Gay, Hiram A., E-mail: hgay@radonc.wustl.edu [Washington University School of Medicine, St Louis, MO (United States); Barthold, H. Joseph [Commonwealth Hematology and Oncology, Weymouth, MA (United States); Beth Israel Deaconess Medical Center, Boston, MA (Israel); O' Meara, Elizabeth [Radiation Therapy Oncology Group, Philadelphia, PA (United States); Bosch, Walter R. [Washington University School of Medicine, St Louis, MO (United States); El Naqa, Issam [Department of Radiation Oncology, McGill University Health Center, Montreal, Quebec (Canada); Al-Lozi, Rawan [Washington University School of Medicine, St Louis, MO (United States); Rosenthal, Seth A. [Radiation Oncology Centers, Radiological Associates of Sacramento, Sacramento, CA (United States); Lawton, Colleen [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States); Lee, W. Robert [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Sandler, Howard [Cedars-Sinai Medical Center, Los Angeles, CA (United States); Zietman, Anthony [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Myerson, Robert [Washington University School of Medicine, St Louis, MO (United States); Dawson, Laura A. [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Ontario (Canada); Willett, Christopher [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Kachnic, Lisa A. [Department of Radiation Oncology, Boston Medical Center, Boston University School of Medicine, Boston, MA (United States); Jhingran, Anuja [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Portelance, Lorraine [University of Miami, Miami, FL (United States); Ryu, Janice [Radiation Oncology Centers, Radiological Associates of Sacramento, Sacramento, CA (United States); and others

    2012-07-01

    Purpose: To define a male and female pelvic normal tissue contouring atlas for Radiation Therapy Oncology Group (RTOG) trials. Methods and Materials: One male pelvis computed tomography (CT) data set and one female pelvis CT data set were shared via the Image-Guided Therapy QA Center. A total of 16 radiation oncologists participated. The following organs at risk were contoured in both CT sets: anus, anorectum, rectum (gastrointestinal and genitourinary definitions), bowel NOS (not otherwise specified), small bowel, large bowel, and proximal femurs. The following were contoured in the male set only: bladder, prostate, seminal vesicles, and penile bulb. The following were contoured in the female set only: uterus, cervix, and ovaries. A computer program used the binomial distribution to generate 95% group consensus contours. These contours and definitions were then reviewed by the group and modified. Results: The panel achieved consensus definitions for pelvic normal tissue contouring in RTOG trials with these standardized names: Rectum, AnoRectum, SmallBowel, Colon, BowelBag, Bladder, UteroCervix, Adnexa{sub R}, Adnexa{sub L}, Prostate, SeminalVesc, PenileBulb, Femur{sub R}, and Femur{sub L}. Two additional normal structures whose purpose is to serve as targets in anal and rectal cancer were defined: AnoRectumSig and Mesorectum. Detailed target volume contouring guidelines and images are discussed. Conclusions: Consensus guidelines for pelvic normal tissue contouring were reached and are available as a CT image atlas on the RTOG Web site. This will allow uniformity in defining normal tissues for clinical trials delivering pelvic radiation and will facilitate future normal tissue complication research.

  5. Eight lectures on theoretical physics

    CERN Document Server

    Planck, Max

    1997-01-01

    In 1909 the great German physicist and Nobel Prize winner Max Planck (1858-1947) delivered a series of eight lectures at Columbia University giving a fascinating overview of the new state of physics, which he had played a crucial role in bringing about. The first, third, fifth, and sixth lectures present his account of the revolutionary developments occasioned when he first applied the quantum hypothesis to blackbody radiation. The reader is given an invaluable opportunity to witness Planck's thought processes both on the level of philosophical principles as well as their application to physi

  6. Medical students' perceptions of video-linked lectures and video-streaming

    Directory of Open Access Journals (Sweden)

    Karen Mattick

    2010-12-01

    Full Text Available Video-linked lectures allow healthcare students across multiple sites, and between university and hospital bases, to come together for the purposes of shared teaching. Recording and streaming video-linked lectures allows students to view them at a later date and provides an additional resource to support student learning. As part of a UK Higher Education Academy-funded Pathfinder project, this study explored medical students' perceptions of video-linked lectures and video-streaming, and their impact on learning. The methodology involved semi-structured interviews with 20 undergraduate medical students across four sites and five year groups. Several key themes emerged from the analysis. Students generally preferred live lectures at the home site and saw interaction between sites as a major challenge. Students reported that their attendance at live lectures was not affected by the availability of streamed lectures and tended to be influenced more by the topic and speaker than the technical arrangements. These findings will inform other educators interested in employing similar video technologies in their teaching.Keywords: video-linked lecture; video-streaming; student perceptions; decisionmaking; cross-campus teaching.

  7. A Social Evaluation of Perception on Body Contouring Surgery by Turkish Male Aesthetic Surgery Patients.

    Science.gov (United States)

    Ozel, Bora; Sezgin, Billur; Guney, Kirdar; Latifoglu, Osman; Celebi, Cemallettin

    2015-02-01

    Although aesthetic procedures are known to have a higher impact on women, men are becoming more inclined toward such procedures since the last decade. To determine the reason behind the increase in demand for male aesthetic procedures and to learn about the expectations and inquietude related to body contouring surgery, a prospective questionnaire study was conducted on 200 Turkish males from January 1, 2011-May 31, 2012. Demographic information, previous aesthetic procedures and thoughts on body contouring procedures with given reasons were questioned. The results of the study showed that 53 % of all participants considered undergoing body contouring surgery with the given reason that they believed their current body structure required it. For those who did not consider contouring operations, 92.5 % said they felt that they did not need such a procedure. The results of the statistical analysis showed that BMI was a significant factor in the decision making process for wanting to undergo body contouring procedures. The results of the study showed that men's consideration for aesthetic operations depends mainly on necessity and that the most considered region was the abdominal zone in regard to contouring. We can conclude that men are becoming more interested in body contouring operations and therefore different surgical procedures should be refined and re-defined according to the expectations of this new patient group.

  8. Smooth halos in the cosmic web

    Energy Technology Data Exchange (ETDEWEB)

    Gaite, José, E-mail: jose.gaite@upm.es [Physics Dept., ETSIAE, IDR, Universidad Politécnica de Madrid, Pza. Cardenal Cisneros 3, E-28040 Madrid (Spain)

    2015-04-01

    Dark matter halos can be defined as smooth distributions of dark matter placed in a non-smooth cosmic web structure. This definition of halos demands a precise definition of smoothness and a characterization of the manner in which the transition from smooth halos to the cosmic web takes place. We introduce entropic measures of smoothness, related to measures of inequality previously used in economy and with the advantage of being connected with standard methods of multifractal analysis already used for characterizing the cosmic web structure in cold dark matter N-body simulations. These entropic measures provide us with a quantitative description of the transition from the small scales portrayed as a distribution of halos to the larger scales portrayed as a cosmic web and, therefore, allow us to assign definite sizes to halos. However, these ''smoothness sizes'' have no direct relation to the virial radii. Finally, we discuss the influence of N-body discreteness parameters on smoothness.

  9. Smooth halos in the cosmic web

    International Nuclear Information System (INIS)

    Gaite, José

    2015-01-01

    Dark matter halos can be defined as smooth distributions of dark matter placed in a non-smooth cosmic web structure. This definition of halos demands a precise definition of smoothness and a characterization of the manner in which the transition from smooth halos to the cosmic web takes place. We introduce entropic measures of smoothness, related to measures of inequality previously used in economy and with the advantage of being connected with standard methods of multifractal analysis already used for characterizing the cosmic web structure in cold dark matter N-body simulations. These entropic measures provide us with a quantitative description of the transition from the small scales portrayed as a distribution of halos to the larger scales portrayed as a cosmic web and, therefore, allow us to assign definite sizes to halos. However, these ''smoothness sizes'' have no direct relation to the virial radii. Finally, we discuss the influence of N-body discreteness parameters on smoothness

  10. Evaluation of the optical conductivity tensor in terms of contour integrations

    OpenAIRE

    Szunyogh, Laszlo; Weinberger, Peter

    2000-01-01

    For the case of finite life-time broadening the standard Kubo-formula for the optical conductivity tensor is rederived in terms of Green's functions by using contour integrations, whereby finite temperatures are accounted for by using the Fermi-Dirac distribution function. For zero life-time broadening, the present formalism is related to expressions well-known in the literature. Numerical aspects of how to calculate the corresponding contour integrals are also outlined.

  11. Ship-borne contour integration for flux determination

    NARCIS (Netherlands)

    Groeskamp, S.; Maas, L.R.M.

    2012-01-01

    The consumption of nutrients by mussel beds can be monitored by measuring the net nutrient flux across a circumscribing vertical surface. Measuring this nutrient flux not only requires resolving the spatial (and temporal) distribution of nutrients at the bounding contour, but also an ability to

  12. Feasibility of geometrical verification of patient set-up using body contours and computed tomography data

    International Nuclear Information System (INIS)

    Ploeger, Lennert S.; Betgen, Anja; Gilhuijs, Kenneth G.A.; Herk, Marcel van

    2003-01-01

    Background and purpose: Body contours can potentially be used for patient set-up verification in external-beam radiotherapy and might enable more accurate set-up of patients prior to irradiation. The aim of this study is to test the feasibility of patient set-up verification using a body contour scanner. Material and methods: Body contour scans of 33 lung cancer and 21 head-and-neck cancer patients were acquired on a simulator. We assume that this dataset is representative for the patient set-up on an accelerator. Shortly before acquisition of the body contour scan, a pair of orthogonal simulator images was taken as a reference. Both the body contour scan and the simulator images were matched in 3D to the planning computed tomography scan. Movement of skin with respect to bone was quantified based on an analysis of variance method. Results: Set-up errors determined with body-contours agreed reasonably well with those determined with simulator images. For the lung cancer patients, the average set-up errors (mm)±1 standard deviation (SD) for the left-right, cranio-caudal and anterior-posterior directions were 1.2±2.9, -0.8±5.0 and -2.3±3.1 using body contours, compared to -0.8±3.2, -1.0±4.1 and -1.2±2.4 using simulator images. For the head-and-neck cancer patients, the set-up errors were 0.5±1.8, 0.5±2.7 and -2.2±1.8 using body contours compared to -0.4±1.2, 0.1±2.1, -0.1±1.8 using simulator images. The SD of the set-up errors obtained from analysis of the body contours were not significantly different from those obtained from analysis of the simulator images. Movement of the skin with respect to bone (1 SD) was estimated at 2.3 mm for lung cancer patients and 1.7 mm for head-and-neck cancer patients. Conclusion: Measurement of patient set-up using a body-contouring device is possible. The accuracy, however, is limited by the movement of the skin with respect to the bone. In situations where the error in the patient set-up is relatively large, it is

  13. Lecture classes in human anatomy: the students' perceptions.

    Science.gov (United States)

    Kar, Maitreyee; Roy, Hironmoy; Ghosh, Anasuya; Tapadar, Arunabha; Chowdhury, Subhramoy; Mukherjee, Pranab; Jana, Tapan Kumar

    2013-06-01

    The human anatomy, or in brief, the body structure has fascinated man for ages. Due to the information explosion and the increase in specializations, this knowledge is available in a very sketchy manner in high school biology courses. The first comprehensive course on the human anatomy is taught to the first year medical students in medical colleges. This is in keeping with the regulations of the Medical Council of India. The anatomy lecture classes occupy a considerable time of the course, to provide the students with an effective knowledge of the gross anatomy, histology, embryology and the clinical anatomy. On the other hand, the students' feedback regarding the lecture methods and the teaching environment is crucial in judging the efficacy of the present curriculum. To obtain the students' feedback about the environment of the lecture classes, as regards the venue, the teaching and learning aids which are used, the lecture class schedule of the university (the number of classes per week, the durations of the lecture classes, etc.) and the existing departmental practices (display of the class routine in advance, synchronization between the lecture and the practical classes), so that their suggestions could help the faculty in planning the most effective teaching procedures. A semi structured questionnaire was supplied to the students to get their feedback. Most of the students found the air conditioned seminar room's environment to be more comfortable and they supported the existing durations of the lecture hours with the combined use of chalk and a board and overhead projectors (OHPs). The perceptions of the learners helped in modifying the departmental practice in the desired way.

  14. Measuring multiple residual-stress components using the contour method and multiple cuts

    Energy Technology Data Exchange (ETDEWEB)

    Prime, Michael B [Los Alamos National Laboratory; Swenson, Hunter [Los Alamos National Laboratory; Pagliaro, Pierluigi [U. PALERMO; Zuccarello, Bernardo [U. PALERMO

    2009-01-01

    The conventional contour method determines one component of stress over the cross section of a part. The part is cut into two, the contour of the exposed surface is measured, and Bueckner's superposition principle is analytically applied to calculate stresses. In this paper, the contour method is extended to the measurement of multiple stress components by making multiple cuts with subsequent applications of superposition. The theory and limitations are described. The theory is experimentally tested on a 316L stainless steel disk with residual stresses induced by plastically indenting the central portion of the disk. The stress results are validated against independent measurements using neutron diffraction. The theory has implications beyond just multiple cuts. The contour method measurements and calculations for the first cut reveal how the residual stresses have changed throughout the part. Subsequent measurements of partially relaxed stresses by other techniques, such as laboratory x-rays, hole drilling, or neutron or synchrotron diffraction, can be superimposed back to the original state of the body.

  15. TU-C-17A-03: An Integrated Contour Evaluation Software Tool Using Supervised Pattern Recognition for Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Chen, H; Tan, J; Kavanaugh, J; Dolly, S; Gay, H; Thorstad, W; Anastasio, M; Altman, M; Mutic, S; Li, H [Washington University School of Medicine, Saint Louis, MO (United States)

    2014-06-15

    Purpose: Radiotherapy (RT) contours delineated either manually or semiautomatically require verification before clinical usage. Manual evaluation is very time consuming. A new integrated software tool using supervised pattern contour recognition was thus developed to facilitate this process. Methods: The contouring tool was developed using an object-oriented programming language C# and application programming interfaces, e.g. visualization toolkit (VTK). The C# language served as the tool design basis. The Accord.Net scientific computing libraries were utilized for the required statistical data processing and pattern recognition, while the VTK was used to build and render 3-D mesh models from critical RT structures in real-time and 360° visualization. Principal component analysis (PCA) was used for system self-updating geometry variations of normal structures based on physician-approved RT contours as a training dataset. The inhouse design of supervised PCA-based contour recognition method was used for automatically evaluating contour normality/abnormality. The function for reporting the contour evaluation results was implemented by using C# and Windows Form Designer. Results: The software input was RT simulation images and RT structures from commercial clinical treatment planning systems. Several abilities were demonstrated: automatic assessment of RT contours, file loading/saving of various modality medical images and RT contours, and generation/visualization of 3-D images and anatomical models. Moreover, it supported the 360° rendering of the RT structures in a multi-slice view, which allows physicians to visually check and edit abnormally contoured structures. Conclusion: This new software integrates the supervised learning framework with image processing and graphical visualization modules for RT contour verification. This tool has great potential for facilitating treatment planning with the assistance of an automatic contour evaluation module in avoiding

  16. Comparison of some nonlinear smoothing methods

    International Nuclear Information System (INIS)

    Bell, P.R.; Dillon, R.S.

    1977-01-01

    Due to the poor quality of many nuclear medicine images, computer-driven smoothing procedures are frequently employed to enhance the diagnostic utility of these images. While linear methods were first tried, it was discovered that nonlinear techniques produced superior smoothing with little detail suppression. We have compared four methods: Gaussian smoothing (linear), two-dimensional least-squares smoothing (linear), two-dimensional least-squares bounding (nonlinear), and two-dimensional median smoothing (nonlinear). The two dimensional least-squares procedures have yielded the most satisfactorily enhanced images, with the median smoothers providing quite good images, even in the presence of widely aberrant points

  17. Academic Training Lecture: Statistical Methods for Particle Physics

    CERN Multimedia

    PH Department

    2012-01-01

    2, 3, 4 and 5 April 2012 Academic Training Lecture  Regular Programme from 11:00 to 12:00 -  Bldg. 222-R-001 - Filtration Plant Statistical Methods for Particle Physics by Glen Cowan (Royal Holloway) The series of four lectures will introduce some of the important statistical methods used in Particle Physics, and should be particularly relevant to those involved in the analysis of LHC data. The lectures will include an introduction to statistical tests, parameter estimation, and the application of these tools to searches for new phenomena.  Both frequentist and Bayesian methods will be described, with particular emphasis on treatment of systematic uncertainties.  The lectures will also cover unfolding, that is, estimation of a distribution in binned form where the variable in question is subject to measurement errors.

  18. Development and evaluation of a new contoured cushion system with an optimized normalization algorithm.

    Science.gov (United States)

    Li, Sujiao; Zhang, Zhengxiang; Wang, Jue

    2014-01-01

    Prevention of pressure sores remains a significant problem confronting spinal cord injury patients and the elderly with limited mobility. One vital aspect of this subject concerns the development of cushions to decrease pressure ulcers for seated patients, particularly those bound by wheelchairs. Here, we present a novel cushion system that employs interface pressure distribution between the cushion and the buttocks to design custom contoured foam cushion. An optimized normalization algorithm was proposed, with which interface pressure distribution was transformed into the carving depth of foam cushions according to the biomechanical characteristics of the foam. The shape and pressure-relief performance of the custom contoured foam cushions was investigated. The outcomes showed that the contoured shape of personalized cushion matched the buttock contour very well. Moreover, the custom contoured cushion could alleviate pressure under buttocks and increase subjective comfort and stability significantly. Furthermore, the fabricating method not only decreased the unit production cost but also simplified the procedure for manufacturing. All in all, this prototype seat cushion would be an effective and economical way to prevent pressure ulcers.

  19. Analysis of irradiance losses on a soiled photovoltaic panel using contours

    International Nuclear Information System (INIS)

    Pulipaka, Subrahmanyam; Kumar, Rajneesh

    2016-01-01

    Highlights: • An irradiance loss factor to quantify relationship between irradiance, tilt angle and power of soiled panel is proposed. • Artificial soiling experiment and Sieve analysis are performed to obtain data for developing contours. • Contour analysis is used to observe the deviation in power of a soiled panel from clean panel. • A correction factor to calculate power of a soiled panel is proposed. • The correction factor is expressed in terms of soil particle size composition present on panel. - Abstract: This paper introduces an irradiance loss factor that quantifies the relationship between irradiance, tilt angle and power output of a soiled panel with the soil particle size composition. Artificial soiling experiments were performed using four soil samples at irradiance levels between 200 and 1200 W/m"2 at 18 tilt angles. Biharmonic interpolation was used to develop power contours in terms of irradiance and tilt angle from experimentally obtained data. These contours were compared with ideal ones of a clean panel to observe deviation in the nature of contours for a soiled panel. A correction factor in terms of particle size composition (as a coefficient to tilt angle) was proposed to calculate power output of a tilted soiled panel. The angular loss on a panel with soil sample containing 150 μm particle size in abundance was observed to be 22% and for sample containing 75 μm particles in majority, the loss is 24%. Presence of 300 μm particle size in abundance causes a 23.7% loss, while 52% angular loss was observed for soil with highest composition of less than 75 μm particle size.

  20. Special lecture

    International Nuclear Information System (INIS)

    Yoshikawa, H.

    1998-01-01

    In his special lecture, given at the Artsimovich-Kadomtsev Memorial Session of the 17th IAEA Fusion Energy Conference in Yokohama, October 1998, Prof. H. Yoshikawa stated that the fusion program had come to a crossroads. He was wondering whether the future would lead to cooperation between nations, striving to overcome the difficulties the world is confronted with, or if it would lead to despair

  1. AN IMPROVED SNAKE MODEL FOR REFINEMENT OF LIDAR-DERIVED BUILDING ROOF CONTOURS USING AERIAL IMAGES

    Directory of Open Access Journals (Sweden)

    Q. Chen

    2016-06-01

    Full Text Available Building roof contours are considered as very important geometric data, which have been widely applied in many fields, including but not limited to urban planning, land investigation, change detection and military reconnaissance. Currently, the demand on building contours at a finer scale (especially in urban areas has been raised in a growing number of studies such as urban environment quality assessment, urban sprawl monitoring and urban air pollution modelling. LiDAR is known as an effective means of acquiring 3D roof points with high elevation accuracy. However, the precision of the building contour obtained from LiDAR data is restricted by its relatively low scanning resolution. With the use of the texture information from high-resolution imagery, the precision can be improved. In this study, an improved snake model is proposed to refine the initial building contours extracted from LiDAR. First, an improved snake model is constructed with the constraints of the deviation angle, image gradient, and area. Then, the nodes of the contour are moved in a certain range to find the best optimized result using greedy algorithm. Considering both precision and efficiency, the candidate shift positions of the contour nodes are constrained, and the searching strategy for the candidate nodes is explicitly designed. The experiments on three datasets indicate that the proposed method for building contour refinement is effective and feasible. The average quality index is improved from 91.66% to 93.34%. The statistics of the evaluation results for every single building demonstrated that 77.0% of the total number of contours is updated with higher quality index.

  2. Extension of Fourier methods to the calculation of effective depths in heterogeneous media of arbitrary contour

    International Nuclear Information System (INIS)

    Starkschall, G.

    1986-01-01

    The description of patient contours and internal structures by means of truncated Fourier series can be extended to continuous contours of arbitrary shape and location by expressing the x and z Cartesian coordinates of the contour as independent Fourier series in a parameter t. An analytic equation for the intersection of the contour and a ray line is then written as an equation in the parameter t. The equation can be solved using numerical methods yielding the Cartesian coordinates of the intersection point directly

  3. Variations in the Contouring of Organs at Risk: Test Case From a Patient With Oropharyngeal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Nelms, Benjamin E., E-mail: alpha@canislupusllc.com [Canis Lupus LLC, Merrimac, WI (United States); Tome, Wolfgang A. [Department of Human Oncology, University of Wisconsin, Madison, WI (United States); Robinson, Greg [Radiation Oncology Resources, Goshen, IN (United States); Wheeler, James [Department of Radiation Oncology, Goshen Health System Goshen, IN (United States)

    2012-01-01

    Purpose: Anatomy contouring is critical in radiation therapy. Inaccuracy and variation in defining critical volumes will affect everything downstream: treatment planning, dose-volume histogram analysis, and contour-based visual guidance used in image-guided radiation therapy. This study quantified: (1) variation in the contouring of organs at risk (OAR) in a clinical test case and (2) corresponding effects on dosimetric metrics of highly conformal plans. Methods and Materials: A common CT data set with predefined targets from a patient with oropharyngeal cancer was provided to a population of clinics, which were asked to (1) contour OARs and (2) design an intensity-modulated radiation therapy plan. Thirty-two acceptable plans were submitted as DICOM RT data sets, each generated by a different clinical team. Using those data sets, we quantified: (1) the OAR contouring variation and (2) the impact this variation has on dosimetric metrics. New technologies were employed, including a software tool to quantify three-dimensional structure comparisons. Results: There was significant interclinician variation in OAR contouring. The degree of variation is organ-dependent. We found substantial dose differences resulting strictly from contouring variation (differences ranging from -289% to 56% for mean OAR dose; -22% to 35% for maximum dose). However, there appears to be a threshold in the OAR comparison metric beyond which the dose differences stabilize. Conclusions: The effects of interclinician variation in contouring organs-at-risk in the head and neck can be large and are organ-specific. Physicians need to be aware of the effect that variation in OAR contouring can play on the final treatment plan and not restrict their focus only to the target volumes.

  4. What Predicts Skill in Lecture Note Taking?

    Science.gov (United States)

    Peverly, Stephen T.; Ramaswamy, Vivek; Brown, Cindy; Sumowski, James; Alidoost, Moona; Garner, Joanna

    2007-01-01

    Despite the importance of good lecture notes to test performance, very little is known about the cognitive processes that underlie effective lecture note taking. The primary purpose of the 2 studies reported (a pilot study and Study 1) was to investigate 3 processes hypothesized to be significantly related to quality of notes: transcription…

  5. Software approach to minimizing problems of student-lecturer ...

    African Journals Online (AJOL)

    Lecturer Interaction in Higher institutions of learning. The Software was developed using PHP and hosted in the University web server, and the interaction between students and their lecturers was compared using both the traditional approaches ...

  6. On the Relationship between Variational Level Set-Based and SOM-Based Active Contours

    Science.gov (United States)

    Abdelsamea, Mohammed M.; Gnecco, Giorgio; Gaber, Mohamed Medhat; Elyan, Eyad

    2015-01-01

    Most Active Contour Models (ACMs) deal with the image segmentation problem as a functional optimization problem, as they work on dividing an image into several regions by optimizing a suitable functional. Among ACMs, variational level set methods have been used to build an active contour with the aim of modeling arbitrarily complex shapes. Moreover, they can handle also topological changes of the contours. Self-Organizing Maps (SOMs) have attracted the attention of many computer vision scientists, particularly in modeling an active contour based on the idea of utilizing the prototypes (weights) of a SOM to control the evolution of the contour. SOM-based models have been proposed in general with the aim of exploiting the specific ability of SOMs to learn the edge-map information via their topology preservation property and overcoming some drawbacks of other ACMs, such as trapping into local minima of the image energy functional to be minimized in such models. In this survey, we illustrate the main concepts of variational level set-based ACMs, SOM-based ACMs, and their relationship and review in a comprehensive fashion the development of their state-of-the-art models from a machine learning perspective, with a focus on their strengths and weaknesses. PMID:25960736

  7. A 3-Step Algorithm Using Region-Based Active Contours for Video Objects Detection

    Directory of Open Access Journals (Sweden)

    Stéphanie Jehan-Besson

    2002-06-01

    Full Text Available We propose a 3-step algorithm for the automatic detection of moving objects in video sequences using region-based active contours. First, we introduce a very full general framework for region-based active contours with a new Eulerian method to compute the evolution equation of the active contour from a criterion including both region-based and boundary-based terms. This framework can be easily adapted to various applications, thanks to the introduction of functions named descriptors of the different regions. With this new Eulerian method based on shape optimization principles, we can easily take into account the case of descriptors depending upon features globally attached to the regions. Second, we propose a 3-step algorithm for detection of moving objects, with a static or a mobile camera, using region-based active contours. The basic idea is to hierarchically associate temporal and spatial information. The active contour evolves with successively three sets of descriptors: a temporal one, and then two spatial ones. The third spatial descriptor takes advantage of the segmentation of the image in intensity homogeneous regions. User interaction is reduced to the choice of a few parameters at the beginning of the process. Some experimental results are supplied.

  8. Lecture Evaluations by Medical Students: Concepts That Correlate With Scores.

    Science.gov (United States)

    Jen, Aaron; Webb, Emily M; Ahearn, Bren; Naeger, David M

    2016-01-01

    The didactic lecture remains one of the most popular teaching formats in medical education; yet, factors that most influence lecturing success in radiology education are unknown. The purpose of this study is to identify patterns of narrative student feedback that are associated with relatively higher and lower evaluation scores. All student evaluations from our core radiology elective during 1 year were compiled. All evaluation comments were tagged, to identify discrete descriptive concepts. Correlation coefficients were calculated, for each tag with mean evaluation scores. Tags that were the most strongly associated with the highest- versus lowest-rated (> or < 1 SD) lectures were identified. A total of 3,262 comments, on 273 lectures, rated by 77 senior medical students, were analyzed. The mean lecture score was 8.96 ± 0.62. Three tags were significantly positively correlated with lecture score: "interactive"; "fun/engaging"; and "practical/important content" (r = 0.39, r = 0.34, and r = 0.32, respectively; all P < .001). More tags (n = 12) were significantly negatively correlated with score; the three tags with the strongest such correlation were: "not interactive"; "poorly structured or unevenly paced"; and "content too detailed or abundant" (r = -0.44, r = -0.39, and r = -0.36, respectively; all P < .001). Analysis of only the highest- and lowest-rated lectures yielded similar results. Several factors were identified that were strongly associated with lecture score. Among the actionable characteristics, interactive lectures with appropriately targeted content (ie, practical/useful) were the most highly rated. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  9. Sound wave contours around wind turbine arrays

    International Nuclear Information System (INIS)

    Van Beek, A.; Van Blokland, G.J.

    1993-02-01

    Noise pollution is an important factor in selecting suitable sites for wind turbines in order to realize 1000 MW of wind power as planned by the Dutch government for the year 2000. Therefore an accurate assessment of wind turbine noise is important. The amount of noise pollution from a wind turbine depends on the wind conditions. An existing standard method to assess wind turbine noise is supplemented and adjusted. In the first part of the investigation the method was developed and applied for a solitary sound source. In the second part attention is paid to the use of the method for wind turbine arrays. It appears that the adjusted method results in a shift of the contours of the permitted noise level. In general the contours are 15-25% closer to the wind farm, which means that the minimal permitted distance between houses and wind turbine arrays can be reduced. 14 figs., 1 tab., 4 appendices, 7 refs

  10. ACADEMIC TRAINING LECTURE

    CERN Multimedia

    Academic Training; Tel. 73127

    2001-01-01

    14, 15 and 16 May REGULAR LECTURE PROGRAMME 14, 15 May from 10:00 to 12:00 hrs - Main Auditorium bldg. 500 16 May from 11:00 to 12:00 hrs - Council Chamber, bldg 503 Modern Signal Processing: Wavelets vs. Fourier M. Vetterli / EPFL, Lausanne, CH and UC Berkeley Wavelets have established themselves as an important tool in modern signal processing as well as in applied mathematics. This is linked to several facts, among others: New theoretical advances have been achieved, like new forms of 4 time-frequency bases for signal analysis. Efficient computational algorithms are available. Many applications either used similar ideas, like for example the concept of multiresolution, or took advantage of the unified framework provided by wavelets. This combination of elegant theory, efficient algorithms, and successful applications makes the field of wavelets and signal processing quite exciting. It is the purpose of these lectures to establish the theory necessary to understand wavelets and related constructions. A...

  11. ACADEMIC TRAINING LECTURE

    CERN Multimedia

    Academic Training; Tel. 73127

    2001-01-01

    14, 15 and 16 May REGULAR LECTURE PROGRAMME 14, 15 May from 10:00 to 12:00 hrs - Main Auditorium bldg. 500 16 May from 11:00 to 12:00 hrs - Council Chamber, bldg 503 Modern Signal Processing: Wavelets vs. Fourier M. Vetterli / EPFL, Lausanne, CH and UC Berkeley Wavelets have established themselves as an important tool in modern signal processing as well as in applied mathematics. This is linked to several facts, among others: i. New theoretical advances have been achieved, like new forms of 4 time-frequency bases for signal analysis. ii. Efficient computational algorithms are available. iii. Many applications either used similar ideas, like for example the concept of multiresolution, or took advantage of the unified framework provided by wavelets. This combination of elegant theory, efficient algorithms, and successful applications makes the field of wavelets and signal processing quite exciting. It is the purpose of these lectures to establish the theory necessary to understand wavelets and related construct...

  12. ACADEMIC TRAINING LECTURE

    CERN Multimedia

    Françoise Benz

    2002-01-01

    18, 19, 20, 21, 22 November LECTURE FOR POSTGRADUATE STUDENTS From 11:00 hrs - Main Auditorium bldg. 500 Telling the Truth with Statistics R. Barlow / Univ. of Manchester, UK This course of lectures will cover probability, distributions, fitting, errors and confidence levels, for practising High Energy Physicists who need to use Statistical techniques to express their results. Concentrating on these appropriate specialist techniques means that they can be covered in appropriate depth, while assuming only the knowledge and experience of a typical Particle Physicist. The different definitions of probability will be explained, and it will be appear why this basic subject is so controversial; there are several viewpoints and it is important to understand them all, rather than abusing the adherents of different beliefs. Distributions will be covered: the situations they arise in, their useful properties, and the amazing result of the Central Limit Theorem. Fitting a parametrisation to a set of data is one of the m...

  13. Globe: Lecture series

    CERN Multimedia

    2007-01-01

    The LHC: an accelerator of science This series of lectures is all about understanding the scientific and technological challenges of the phenomenal LHC project and assessing its innovations through their everyday applications. Come and take a sneak preview of the LHC! Communicate: the Grid, a computer of global dimensions François Grey, head of communication in CERN’s Information Technology Department How will it be possible for the 15 million billion bytes of data generated by the LHC every year to be handled and stored by a computer that doesn’t have to be the size of a skyscraper? The computer scientists have the answer: the Grid, which will harness the power of tens of thousands of computers all over the world by creating a network of computers and making them operate as one. >>> Lectures are free and require no specialist knowledge. In french. 
 >>> By reservation only: tel. +41 (0)22 767 76 76

  14. Confchem Conference on Flipped Classroom: Student Engagement with Flipped Chemistry Lectures

    Science.gov (United States)

    Seery, Michael K.

    2015-01-01

    This project introduces the idea of "flipped lecturing" to a group of second-year undergraduate students. The aim of flipped lecturing is to provide much of the "content delivery" of the lecture in advance, so that the lecture hour can be devoted to more in-depth discussion, problem solving, and so on. As well as development of…

  15. Short lecture series in sustainable product development

    DEFF Research Database (Denmark)

    McAloone, Tim C.

    2005-01-01

    Three lectures in sustainable product development models, methods and mindsets should give insight into the way of thinking about the environment when developing products. The first two lectures will guide you through: . Environmental problems in industry & life-cycle thinking . Professional...... methods for analysing and changing products’ environmental profiles . Sustainability as a driver for innovation...

  16. SOCIAL MEDIA USE AND PERCEPTION OF LIVE LECTURES BY MEDICAL STUDENTS

    Directory of Open Access Journals (Sweden)

    Nisha Narendran

    2017-02-01

    Full Text Available BACKGROUND The current generation is rightly described as generation M (edia highlighting the increasing time spent with media on any given day. The availability of mobiles and the absence of mobile jammers in lecture classes will seriously interfere with lecture attendance or concentration in lecture hours. We intend to take a survey on the level of social media use or use of smartphone for other non-academic uses by medical students during their lecture hours. We expect them to put forward their views as to how they perceive live lectures and what can be done to improve the effect of live lectures in this era of widespread and anytime media use. Aims of the study were- 1. To conduct a survey among medical students in preclinical postings regarding use of social media use during live lecture hours. 2. To assess their perception regarding conventional lecture duration and the factors, which could improve their concentration during lecture hours. MATERIALS AND METHODS A cross-sectional descriptive study was conducted among the participants. Approval was obtained from the Institutional Research Committee. All the 135 participants of the study were administered a semi-structured prevalidated questionnaire to assess their perception regarding live lecture and a survey regarding use of social media was taken. The collected data was entered into MS Excel and analysed using Epiinfo version 7. Percentages were used to quantify the results. Settings and Design- The study was conducted among third semester students attending pharmacology lectures in Government Medical College, Thrissur. RESULTS 77 (57% participants agreed of using social media regularly in lecture hours. Majority used it to chat or connect with friends and in gaming either because of addiction or to avoid boredom. They were a majority in opinion that the hot noon time lectures should be cut short in duration. They preferred the use of newer technology based methods to be adopted for

  17. Top-Down Modulation on the Perception and Categorization of Identical Pitch Contours in Speech and Music

    Directory of Open Access Journals (Sweden)

    Joey L. Weidema

    2016-06-01

    Full Text Available Whether pitch in language and music is governed by domain-specific or domain-general cognitive mechanisms is contentiously debated. The aim of the present study was to investigate whether mechanisms governing pitch contour perception operate differently when pitch information is interpreted as either speech or music. By modulating listening mode, this study aspired to demonstrate that pitch contour perception relies on domain-specific cognitive mechanisms, which are regulated by top-down influences from language and music. Three groups of participants (Mandarin speakers, Dutch speaking non-musicians, and Dutch musicians were exposed to identical pitch contours, and tested on their ability to identify these contours in a language and musical context. Stimuli consisted of disyllabic words spoken in Mandarin, and melodic tonal analogues, embedded in a linguistic and melodic carrier phrase, respectively. Participants classified identical pitch contours as significantly different depending on listening mode. Top-down influences from language appeared to alter the perception of pitch contour in speakers of Mandarin. This was not the case for non-musician speakers of Dutch. Moreover, this effect was lacking in Dutch speaking musicians. The classification patterns of pitch contours in language and music seem to suggest that domain-specific categorization is modulated by top-down influences from language and music.

  18. Programmed Multi-Image Lectures for College Biology Instruction.

    Science.gov (United States)

    Jensen, William A.; Knauft, Robert L.

    1977-01-01

    Discusses the use of a programed multi-image lecture approach for teaching a botany course to nonmajor students at the University of California, Berkeley. Also considers the advantages, production, method of presentation, and design of the multimedia lectures. (HM)

  19. An automated approach for segmentation of intravascular ultrasound images based on parametric active contour models

    International Nuclear Information System (INIS)

    Vard, Alireza; Jamshidi, Kamal; Movahhedinia, Naser

    2012-01-01

    This paper presents a fully automated approach to detect the intima and media-adventitia borders in intravascular ultrasound images based on parametric active contour models. To detect the intima border, we compute a new image feature applying a combination of short-term autocorrelations calculated for the contour pixels. These feature values are employed to define an energy function of the active contour called normalized cumulative short-term autocorrelation. Exploiting this energy function, the intima border is separated accurately from the blood region contaminated by high speckle noise. To extract media-adventitia boundary, we define a new form of energy function based on edge, texture and spring forces for the active contour. Utilizing this active contour, the media-adventitia border is identified correctly even in presence of branch openings and calcifications. Experimental results indicate accuracy of the proposed methods. In addition, statistical analysis demonstrates high conformity between manual tracing and the results obtained by the proposed approaches.

  20. Automated contouring error detection based on supervised geometric attribute distribution models for radiation therapy: A general strategy

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hsin-Chen; Tan, Jun; Dolly, Steven; Kavanaugh, James; Harold Li, H.; Altman, Michael; Gay, Hiram; Thorstad, Wade L.; Mutic, Sasa; Li, Hua, E-mail: huli@radonc.wustl.edu [Department of Radiation Oncology, Washington University, St. Louis, Missouri 63110 (United States); Anastasio, Mark A. [Department of Biomedical Engineering, Washington University, St. Louis, Missouri 63110 (United States); Low, Daniel A. [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California 90095 (United States)

    2015-02-15

    Purpose: One of the most critical steps in radiation therapy treatment is accurate tumor and critical organ-at-risk (OAR) contouring. Both manual and automated contouring processes are prone to errors and to a large degree of inter- and intraobserver variability. These are often due to the limitations of imaging techniques in visualizing human anatomy as well as to inherent anatomical variability among individuals. Physicians/physicists have to reverify all the radiation therapy contours of every patient before using them for treatment planning, which is tedious, laborious, and still not an error-free process. In this study, the authors developed a general strategy based on novel geometric attribute distribution (GAD) models to automatically detect radiation therapy OAR contouring errors and facilitate the current clinical workflow. Methods: Considering the radiation therapy structures’ geometric attributes (centroid, volume, and shape), the spatial relationship of neighboring structures, as well as anatomical similarity of individual contours among patients, the authors established GAD models to characterize the interstructural centroid and volume variations, and the intrastructural shape variations of each individual structure. The GAD models are scalable and deformable, and constrained by their respective principal attribute variations calculated from training sets with verified OAR contours. A new iterative weighted GAD model-fitting algorithm was developed for contouring error detection. Receiver operating characteristic (ROC) analysis was employed in a unique way to optimize the model parameters to satisfy clinical requirements. A total of forty-four head-and-neck patient cases, each of which includes nine critical OAR contours, were utilized to demonstrate the proposed strategy. Twenty-nine out of these forty-four patient cases were utilized to train the inter- and intrastructural GAD models. These training data and the remaining fifteen testing data sets

  1. Automated contouring error detection based on supervised geometric attribute distribution models for radiation therapy: A general strategy

    International Nuclear Information System (INIS)

    Chen, Hsin-Chen; Tan, Jun; Dolly, Steven; Kavanaugh, James; Harold Li, H.; Altman, Michael; Gay, Hiram; Thorstad, Wade L.; Mutic, Sasa; Li, Hua; Anastasio, Mark A.; Low, Daniel A.

    2015-01-01

    Purpose: One of the most critical steps in radiation therapy treatment is accurate tumor and critical organ-at-risk (OAR) contouring. Both manual and automated contouring processes are prone to errors and to a large degree of inter- and intraobserver variability. These are often due to the limitations of imaging techniques in visualizing human anatomy as well as to inherent anatomical variability among individuals. Physicians/physicists have to reverify all the radiation therapy contours of every patient before using them for treatment planning, which is tedious, laborious, and still not an error-free process. In this study, the authors developed a general strategy based on novel geometric attribute distribution (GAD) models to automatically detect radiation therapy OAR contouring errors and facilitate the current clinical workflow. Methods: Considering the radiation therapy structures’ geometric attributes (centroid, volume, and shape), the spatial relationship of neighboring structures, as well as anatomical similarity of individual contours among patients, the authors established GAD models to characterize the interstructural centroid and volume variations, and the intrastructural shape variations of each individual structure. The GAD models are scalable and deformable, and constrained by their respective principal attribute variations calculated from training sets with verified OAR contours. A new iterative weighted GAD model-fitting algorithm was developed for contouring error detection. Receiver operating characteristic (ROC) analysis was employed in a unique way to optimize the model parameters to satisfy clinical requirements. A total of forty-four head-and-neck patient cases, each of which includes nine critical OAR contours, were utilized to demonstrate the proposed strategy. Twenty-nine out of these forty-four patient cases were utilized to train the inter- and intrastructural GAD models. These training data and the remaining fifteen testing data sets

  2. Atlas-Based Segmentation Improves Consistency and Decreases Time Required for Contouring Postoperative Endometrial Cancer Nodal Volumes

    International Nuclear Information System (INIS)

    Young, Amy V.; Wortham, Angela; Wernick, Iddo; Evans, Andrew; Ennis, Ronald D.

    2011-01-01

    Purpose: Accurate target delineation of the nodal volumes is essential for three-dimensional conformal and intensity-modulated radiotherapy planning for endometrial cancer adjuvant therapy. We hypothesized that atlas-based segmentation ('autocontouring') would lead to time savings and more consistent contours among physicians. Methods and Materials: A reference anatomy atlas was constructed using the data from 15 postoperative endometrial cancer patients by contouring the pelvic nodal clinical target volume on the simulation computed tomography scan according to the Radiation Therapy Oncology Group 0418 trial using commercially available software. On the simulation computed tomography scans from 10 additional endometrial cancer patients, the nodal clinical target volume autocontours were generated. Three radiation oncologists corrected the autocontours and delineated the manual nodal contours under timed conditions while unaware of the other contours. The time difference was determined, and the overlap of the contours was calculated using Dice's coefficient. Results: For all physicians, manual contouring of the pelvic nodal target volumes and editing the autocontours required a mean ± standard deviation of 32 ± 9 vs. 23 ± 7 minutes, respectively (p = .000001), a 26% time savings. For each physician, the time required to delineate the manual contours vs. correcting the autocontours was 30 ± 3 vs. 21 ± 5 min (p = .003), 39 ± 12 vs. 30 ± 5 min (p = .055), and 29 ± 5 vs. 20 ± 5 min (p = .0002). The mean overlap increased from manual contouring (0.77) to correcting the autocontours (0.79; p = .038). Conclusion: The results of our study have shown that autocontouring leads to increased consistency and time savings when contouring the nodal target volumes for adjuvant treatment of endometrial cancer, although the autocontours still required careful editing to ensure that the lymph nodes at risk of recurrence are properly included in the target volume.

  3. An improved active contour model for glacial lake extraction

    Science.gov (United States)

    Zhao, H.; Chen, F.; Zhang, M.

    2017-12-01

    Active contour model is a widely used method in visual tracking and image segmentation. Under the driven of objective function, the initial curve defined in active contour model will evolve to a stable condition - a desired result in given image. As a typical region-based active contour model, C-V model has a good effect on weak boundaries detection and anti noise ability which shows great potential in glacial lake extraction. Glacial lake is a sensitive indicator for reflecting global climate change, therefore accurate delineate glacial lake boundaries is essential to evaluate hydrologic environment and living environment. However, the current method in glacial lake extraction mainly contains water index method and recognition classification method are diffcult to directly applied in large scale glacial lake extraction due to the diversity of glacial lakes and masses impacted factors in the image, such as image noise, shadows, snow and ice, etc. Regarding the abovementioned advantanges of C-V model and diffcults in glacial lake extraction, we introduce the signed pressure force function to improve the C-V model for adapting to processing of glacial lake extraction. To inspect the effect of glacial lake extraction results, three typical glacial lake development sites were selected, include Altai mountains, Centre Himalayas, South-eastern Tibet, and Landsat8 OLI imagery was conducted as experiment data source, Google earth imagery as reference data for varifying the results. The experiment consequence suggests that improved active contour model we proposed can effectively discriminate the glacial lakes from complex backgound with a higher Kappa Coefficient - 0.895, especially in some small glacial lakes which belongs to weak information in the image. Our finding provide a new approach to improved accuracy under the condition of large proportion of small glacial lakes and the possibility for automated glacial lake mapping in large-scale area.

  4. Lecturers' Experience of Using Social Media in Higher Education Courses

    Science.gov (United States)

    Seechaliao, Thapanee

    2015-01-01

    This research paper presents lecturers' experience of using social media in higher education courses. The research methodology used a survey approach. The research instrument was a questionnaire about lecturers' experience of using social media in higher education courses. Thirty-one lecturers completed the questionnaire. The data were scored by…

  5. Water Technology Lecture 3: Water Distribution

    OpenAIRE

    Gray, Nicholas Frederick

    2017-01-01

    This is the third lecture in the course Water Technology dealing with water distribution. This is a PowerPoint lecture which is free to use and modify. It was designed to be used in conjunction with the course text Gray, N.F. (2017) Water Science and Technology: An Introduction, published by CRC Press, Oxford. The basis of water distribution is explored including water pipe materials, distribution systems, leakage, water quality problems, pressure issue, water hydrants, effect of floods,...

  6. The relative pose estimation of aircraft based on contour model

    Science.gov (United States)

    Fu, Tai; Sun, Xiangyi

    2017-02-01

    This paper proposes a relative pose estimation approach based on object contour model. The first step is to obtain a two-dimensional (2D) projection of three-dimensional (3D)-model-based target, which will be divided into 40 forms by clustering and LDA analysis. Then we proceed by extracting the target contour in each image and computing their Pseudo-Zernike Moments (PZM), thus a model library is constructed in an offline mode. Next, we spot a projection contour that resembles the target silhouette most in the present image from the model library with reference of PZM; then similarity transformation parameters are generated as the shape context is applied to match the silhouette sampling location, from which the identification parameters of target can be further derived. Identification parameters are converted to relative pose parameters, in the premise that these values are the initial result calculated via iterative refinement algorithm, as the relative pose parameter is in the neighborhood of actual ones. At last, Distance Image Iterative Least Squares (DI-ILS) is employed to acquire the ultimate relative pose parameters.

  7. Comparing Students' and Experts' Understanding of the Content of a Lecture

    Science.gov (United States)

    Hrepic, Zdeslav; Zollman, Dean A.; Sanjay Rebello, N.

    2007-06-01

    In spite of advances in physics pedagogy, the lecture is by far the most widely used format of instruction. We investigated students' understanding and perceptions of the content delivered during a physics lecture. A group of experts (physics instructors) also participated in the study as a reference for the comparison. During the study, all participants responded to a written conceptual survey on sound propagation. Next, they looked for answers to the survey questions in a videotaped lecture by a nationally known teacher. As they viewed the lecture, they indicated instances, if any, in which the survey questions were answered during the lecture. They also wrote down (and if needed, later explained) the answer, which they perceived was given by the instructor in the video lecture. Students who participated in the study were enrolled in a conceptual physics course and had already covered the topic in class before the study. We discuss and compare students' and experts' responses to the survey questions before and after the lecture.

  8. Use of questioning during lectures in a dental hygiene didactic course.

    Science.gov (United States)

    Hessheimer, Heather M; Rogo, Ellen J; Howlett, Bernadette

    2011-08-01

    The purposes of this quasi-experimental, one-group crossover study were to determine the effect of questioning during dental hygiene lectures on low-level and high-level learning and to evaluate student perceptions of questioning. Twenty-three dental hygiene students participated in two control lectures using traditional lecturing methods. The students served as their own controls by next participating in two experimental lectures with questions asked throughout the lecture at both low and high cognitive levels. Student performance was measured with an examination containing low- and high-level questions. The interaction between the group and the level of questions was analyzed using ANOVA, and no statistically significant difference was found. Based on a Likert scale (1 to 6), average ratings for student perceptions were as follows: enjoyment of use, 4.5; understanding the lecture material, 4.74; and questioning effectiveness, 4.35. Student perceptions of questioning were positive; however, this strategy was found to be no more effective than the traditional lecture in promoting retention of information.

  9. Determination of patients contour for using in radiotherapy planning, by microcomputer

    International Nuclear Information System (INIS)

    Elbern, A.W.; Souto, S.L.L.

    1987-01-01

    This work describes a system for measuring the contour of patients, based on a mechanical device which, during the movement of its tip over the patient's contour, changes the resistence of three potenciometers while the device change its angles. The resistence variation, produces voltage changes, which are digitalized by an analog to digital converter in a microcomputer. The mathematical routines for processing the acquired data, and the obtained results, are discussed in this paper. (author) [pt

  10. Determination of patient's contour for use in radiotherapeutic planning by microcomputer

    International Nuclear Information System (INIS)

    Elbern, A.W.; Souto, S.L.L.

    1987-01-01

    A system for measuring the contour of patients based on a mechanical device, is described. During the movement of the device's tip, over the patient's contour, changes in the resistence of three potenciometers are reported, and the device changes its angles. Voltage changes produced by resistence variation, are digitalized by an analog to digital converter in a micro-computer. The mathematical routines for processing the acquired data, and the obtained results are discussed. (M.A.C.) [pt

  11. Impact of online lecture-capture on student outcomes in a therapeutics course.

    Science.gov (United States)

    Bollmeier, Suzanne G; Wenger, Philip J; Forinash, Alicia B

    2010-09-10

    To examine the correlation between students accessing recorded lecture files (audio and slides) online and course grades and class attendance. Second professional year (of 6-year program) students in a therapeutics course had access to recorded online lectures for 72 hours following live lectures. The number and duration of lecture accessions were compared to final course grades and class attendance. Course grades were compared to those of a historical control group. At the end of the semester, students completed a brief survey instrument regarding their use and perceptions of online lectures. No correlation was found between final course grades and the number of lecture accessions (r = 0.0014) or total number of minutes lectures were viewed (r = 0.033), nor between class attendance and minutes viewed (r = 0.2158). Students with access to recorded lectures outperformed the historical control group on the final examination (p students reported no influence of online files on class attendance. Posting lectures online did not affect student outcomes, but students did score higher on the final examination.

  12. Smooth and non-smooth travelling waves in a nonlinearly dispersive Boussinesq equation

    International Nuclear Information System (INIS)

    Shen Jianwei; Xu Wei; Lei Youming

    2005-01-01

    The dynamical behavior and special exact solutions of nonlinear dispersive Boussinesq equation (B(m,n) equation), u tt -u xx -a(u n ) xx +b(u m ) xxxx =0, is studied by using bifurcation theory of dynamical system. As a result, all possible phase portraits in the parametric space for the travelling wave system, solitary wave, kink and anti-kink wave solutions and uncountably infinite many smooth and non-smooth periodic wave solutions are obtained. It can be shown that the existence of singular straight line in the travelling wave system is the reason why smooth waves converge to cusp waves, finally. When parameter are varied, under different parametric conditions, various sufficient conditions guarantee the existence of the above solutions are given

  13. A marriage of continuance: professional development for mathematics lecturers

    Science.gov (United States)

    Barton, Bill; Oates, Greg; Paterson, Judy; Thomas, Mike

    2015-06-01

    In a 2-year project, we developed and trialled a mode of lecturing professional development amongst staff in our department of mathematics. Theoretically grounded in Schoenfeld's resources, orientations, and goals (ROG) model of teacher action, a group met regularly to discuss both the video excerpts of themselves lecturing along with written pre- and post-lecture statements of their "ROGs". We found evidence of improved teaching performance but more interestingly, identified key aspects of our practice and of undergraduate mathematics that received repeated attention and developed further theoretical insight into lecturer behaviour in mathematics. The trial has been successful enough to be expanded into further groups that now constitute a professional development culture within our department.

  14. Fourier Descriptor Analysis and Unification of Voice Range Profile Contours: Method and Applications

    Science.gov (United States)

    Pabon, Peter; Ternstrom, Sten; Lamarche, Anick

    2011-01-01

    Purpose: To describe a method for unified description, statistical modeling, and comparison of voice range profile (VRP) contours, even from diverse sources. Method: A morphologic modeling technique, which is based on Fourier descriptors (FDs), is applied to the VRP contour. The technique, which essentially involves resampling of the curve of the…

  15. Embedding a Virtual Patient Simulator in an Interactive Surgical lecture.

    Science.gov (United States)

    Kleinert, Robert; Plum, Patrick; Heiermann, Nadine; Wahba, Roger; Chang, De-Huan; Hölscher, Arnulf H; Stippel, Dirk L

    2016-01-01

    Lectures are traditionally used for teaching declarative knowledge. One established tool for clinical education is the demonstration of a real patient. The use of real patients in the daily clinical environment is increasingly difficult. The use of a virtual patient simulator (VPS) can potentially circumvent these problems. Unlimited availability and the opportunity of an electronic feedback system could possibly enrich traditional lectures by enabling more interactivity that meets the expectations of the current student generation. As students face the consequences of their own decisions they take a more active role in the lecture. VPS links declarative knowledge with visual perception that is known to influence students' motivation. Until now, there have been no reports covering the usage and validation of interactive VPS for supporting traditional lectures. In this study, we (1) described the development of a custom-made three-dimensional (3D) VPS for supporting the traditional lecture and (2) performed a feasibility study including an initial assessment of this novel educational concept. Conceptualization included definition of curricular content, technical realization and validation. A custom-made simulator was validated with 68 students. The degree of student acceptance was evaluated. Furthermore, the effect on knowledge gain was determined by testing prelecture and postlecture performance. A custom-made simulator prototype that displays a 3D virtual clinic environment was developed and linked to a PowerPoint presentation. Students were able to connect to the simulator via electronic devices (smartphones and tablets) and to control the simulator via majority vote. The simulator was used in 6 lectures and validated in 2 lectures with 68 students each. Student acceptance and their opinion about effectiveness and applicability were determined. Students showed a high level of motivation when using the simulator as most of them had fun using it. Effect on

  16. Authentic Astronomical Discovery in Planetariums: Data-Driven Immersive Lectures

    Science.gov (United States)

    Wyatt, Ryan Jason

    2018-01-01

    Planetariums are akin to “branch offices” for astronomy in major cities and other locations around the globe. With immersive, fulldome video technology, modern digital planetariums offer the opportunity to integrate authentic astronomical data into both pre-recorded shows and live lectures. At the California Academy of Sciences Morrison Planetarium, we host the monthly Benjamin Dean Astronomy Lecture Series, which features researchers describing their cutting-edge work to well-informed lay audiences. The Academy’s visualization studio and engineering teams work with researchers to visualize their data in both pre-rendered and real-time formats, and these visualizations are integrated into a variety of programs—including lectures! The assets are then made available to any other planetariums with similar software to support their programming. A lecturer can thus give the same immersive presentation to audiences in a variety of planetariums. The Academy has also collaborated with Chicago’s Adler Planetarium to bring Kavli Fulldome Lecture Series to San Francisco, and the two theaters have also linked together in live “domecasts” to share real-time content with audiences in both cities. These lecture series and other, similar projects suggest a bright future for astronomers to bring their research to the public in an immersive and visually compelling format.

  17. Utilisation of Electronic Information Resources By Lecturers in ...

    African Journals Online (AJOL)

    This study assesses the use of information resources, specifically, electronic databases by lecturers/teachers in Universities and Colleges of Education in South Western Nigeria. Information resources are central to teachers' education. It provides lecturers/teachers access to information that enhances research and ...

  18. ACADEMIC TRAINING LECTURES-QUESTIONNAIRE

    CERN Multimedia

    Françoise Benz

    2004-01-01

    ACADEMIC TRAINING Françoise Benz tel. 73127 academic.training@cern.ch SUGGEST AND WIN! Its time to plan the 2004-2005 lecture series. From today until March 19 you have the chance to give your contribution to planning for next year's Academic Training Lecture Series. At the web site: http://cern.ch/Academic.Training/questionnaire you will find questionnaires proposing topics in high energy physics, applied physics and science and society. Answering the questionnaire will help ensure that the selected topics are as close as possible to your interests. In particular requests and comments from students will be much appreciated. To encourage your contribution, the AT Committee will reward one lucky winner with a small prize, a 50 CHF coupon for a book purchase at the CERN bookshop.

  19. Lectures on radiation protection

    International Nuclear Information System (INIS)

    Wachsmann, F.; Consentius, K.

    1981-01-01

    All important subjects of radiation protection are presented in concise form; the explanations may serve as lecture manuscripts. The lectures are divided into 16 to 19 teaching units. Each teaching unit is supplemented by a slide to be projected on a screen while the text is read. This method of visual teaching has already been tried with good results in medicine and medical engineering. Pictures of the slides are given in the text so that the book may also be used for self-studies. The main facts are summarized at the end of each lesson. The finished book will consist of 8 lessons; the first three of these discuss 1. Radiation effects and hazards 2. Dose definitions and units and their role in radiology and radiation protection 3. Dose limits and legal specifications. (orig.) [de

  20. The Relationship Between Method of Viewing Lectures, Course Ratings, and Course Timing.

    Science.gov (United States)

    Burton, William B; Ma, Terence P; Grayson, Martha S

    2017-01-01

    In recent years, medical schools have provided students access to video recordings of course lectures, but few studies have investigated the impact of this on ratings of courses and teachers. This study investigated whether the method of viewing lectures was related to student ratings of the course and its components and whether the method used changed over time. Preclinical medical students indicated whether ratings of course lectures were based primarily on lecture attendance, video capture, or both. Students were categorized into Lecture, Video, or Both groups based on their responses to this question. The data consisted of 7584 student evaluations collected over 2 years. Students who attended live lectures rated the course and its components higher than students who only viewed the video or used both methods, although these differences were very small. Students increasingly watched lectures exclusively by video over time: in comparison with first-year students, second-year students were more likely to watch lectures exclusively by video; in comparison with students in the first half of the academic year, students in the second half of the academic year were more likely to watch lectures exclusively by video. With the increase in use of lecture video recordings across medical schools, attention must be paid to student attitudes regarding these methods.

  1. Design optimization of highly asymmetrical layouts by 2D contour metrology

    Science.gov (United States)

    Hu, C. M.; Lo, Fred; Yang, Elvis; Yang, T. H.; Chen, K. C.

    2018-03-01

    As design pitch shrinks to the resolution limit of up-to-date optical lithography technology, the Critical Dimension (CD) variation tolerance has been dramatically decreased for ensuring the functionality of device. One of critical challenges associates with the narrower CD tolerance for whole chip area is the proximity effect control on asymmetrical layout environments. To fulfill the tight CD control of complex features, the Critical Dimension Scanning Electron Microscope (CD-SEM) based measurement results for qualifying process window and establishing the Optical Proximity Correction (OPC) model become insufficient, thus 2D contour extraction technique [1-5] has been an increasingly important approach for complementing the insufficiencies of traditional CD measurement algorithm. To alleviate the long cycle time and high cost penalties for product verification, manufacturing requirements are better to be well handled at design stage to improve the quality and yield of ICs. In this work, in-house 2D contour extraction platform was established for layout design optimization of 39nm half-pitch Self-Aligned Double Patterning (SADP) process layer. Combining with the adoption of Process Variation Band Index (PVBI), the contour extraction platform enables layout optimization speedup as comparing to traditional methods. The capabilities of identifying and handling lithography hotspots in complex layout environments of 2D contour extraction platform allow process window aware layout optimization to meet the manufacturing requirements.

  2. Rapid Automated Target Segmentation and Tracking on 4D Data without Initial Contours

    International Nuclear Information System (INIS)

    Chebrolu, V.V.; Chebrolu, V.V.; Saenz, D.; Tewatia, D.; Paliwal, B.R.; Chebrolu, V.V.; Saenz, D.; Paliwal, B.R.; Sethares, W.A.; Cannon, G.

    2014-01-01

    To achieve rapid automated delineation of gross target volume (GTV) and to quantify changes in volume/position of the target for radiotherapy planning using four-dimensional (4D) CT. Methods and Materials. Novel morphological processing and successive localization (MPSL) algorithms were designed and implemented for achieving auto segmentation. Contours automatically generated using MPSL method were compared with contours generated using state-of-the-art deformable registration methods (using Elastix © and MIMV ista software). Metrics such as the Dice similarity coefficient, sensitivity, and positive predictive value (PPV) were analyzed. The target motion tracked using the centroid of the GTV estimated using MPSL method was compared with motion tracked using deformable registration methods. Results. MPSL algorithm segmented the GTV in 4DCT images in 27.0 ±11.1 seconds per phase ( 512 ×512 resolution) as compared to 142.3±11.3 seconds per phase for deformable registration based methods in 9 cases. Dice coefficients between MPSL generated GTV contours and manual contours (considered as ground-truth) were 0.865 ± 0.037. In comparison, the Dice coefficients between ground-truth and contours generated using deformable registration based methods were 0.909 ± 0.051. Conclusions. The MPSL method achieved similar segmentation accuracy as compared to state-of-the-art deformable registration based segmentation methods, but with significant reduction in time required for GTV segmentation.

  3. Rapid Automated Target Segmentation and Tracking on 4D Data without Initial Contours

    Directory of Open Access Journals (Sweden)

    Venkata V. Chebrolu

    2014-01-01

    Full Text Available Purpose. To achieve rapid automated delineation of gross target volume (GTV and to quantify changes in volume/position of the target for radiotherapy planning using four-dimensional (4D CT. Methods and Materials. Novel morphological processing and successive localization (MPSL algorithms were designed and implemented for achieving autosegmentation. Contours automatically generated using MPSL method were compared with contours generated using state-of-the-art deformable registration methods (using Elastix© and MIMVista software. Metrics such as the Dice similarity coefficient, sensitivity, and positive predictive value (PPV were analyzed. The target motion tracked using the centroid of the GTV estimated using MPSL method was compared with motion tracked using deformable registration methods. Results. MPSL algorithm segmented the GTV in 4DCT images in 27.0±11.1 seconds per phase (512×512 resolution as compared to 142.3±11.3 seconds per phase for deformable registration based methods in 9 cases. Dice coefficients between MPSL generated GTV contours and manual contours (considered as ground-truth were 0.865±0.037. In comparison, the Dice coefficients between ground-truth and contours generated using deformable registration based methods were 0.909 ± 0.051. Conclusions. The MPSL method achieved similar segmentation accuracy as compared to state-of-the-art deformable registration based segmentation methods, but with significant reduction in time required for GTV segmentation.

  4. Rapid Automated Target Segmentation and Tracking on 4D Data without Initial Contours.

    Science.gov (United States)

    Chebrolu, Venkata V; Saenz, Daniel; Tewatia, Dinesh; Sethares, William A; Cannon, George; Paliwal, Bhudatt R

    2014-01-01

    Purpose. To achieve rapid automated delineation of gross target volume (GTV) and to quantify changes in volume/position of the target for radiotherapy planning using four-dimensional (4D) CT. Methods and Materials. Novel morphological processing and successive localization (MPSL) algorithms were designed and implemented for achieving autosegmentation. Contours automatically generated using MPSL method were compared with contours generated using state-of-the-art deformable registration methods (using Elastix© and MIMVista software). Metrics such as the Dice similarity coefficient, sensitivity, and positive predictive value (PPV) were analyzed. The target motion tracked using the centroid of the GTV estimated using MPSL method was compared with motion tracked using deformable registration methods. Results. MPSL algorithm segmented the GTV in 4DCT images in 27.0 ± 11.1 seconds per phase (512 × 512 resolution) as compared to 142.3 ± 11.3 seconds per phase for deformable registration based methods in 9 cases. Dice coefficients between MPSL generated GTV contours and manual contours (considered as ground-truth) were 0.865 ± 0.037. In comparison, the Dice coefficients between ground-truth and contours generated using deformable registration based methods were 0.909 ± 0.051. Conclusions. The MPSL method achieved similar segmentation accuracy as compared to state-of-the-art deformable registration based segmentation methods, but with significant reduction in time required for GTV segmentation.

  5. Contour analysis of steady state tokamak reactor performance

    International Nuclear Information System (INIS)

    Devoto, R.S.; Fenstermacher, M.E.

    1990-01-01

    A new method of analysis for presenting the possible operating space for steady state, non-ignited tokamak reactors is proposed. The method uses contours of reactor performance and plasma characteristics, fusion power gain, wall neutron flux, current drive power, etc., plotted on a two-dimensional grid, the axes of which are the plasma current I p and the normalized beta, β n = β/(I p /aB 0 ), to show possible operating points. These steady state operating contour plots are called SOPCONS. This technique is illustrated in an application to a design for the International Thermonuclear Experimental Reactor (ITER) with neutral beam, lower hybrid and bootstrap current drive. The utility of the SOPCON plots for pointing out some of the non-intuitive considerations in steady state reactor design is shown. (author). Letter-to-the-editor. 16 refs, 3 figs, 1 tab

  6. Feynman Lectures on Computation

    CERN Document Server

    Feynman, Richard Phillips; Allen, Robin W

    1999-01-01

    "When, in 1984-86, Richard P. Feynman gave his famous course on computation at the California Institute of Technology, he asked Tony Hey to adapt his lecture notes into a book. Although led by Feynman,"

  7. Re-living anatomy: medical student use of lecture capture

    OpenAIRE

    Diss, L; Sharp, A; Scott, F; Moore, L; Daniel, P; Memon, S; Smith, C

    2017-01-01

    Lecture capture resources have become common place within UK Higher education to enhance and support learning in addition to the tradition lecture. These resources can be particularly useful for medical students in anatomy teaching where time dedicated to anatomy within the curriculum has been reduced compared to previous generations(1).\\ud \\ud This study aimed to investigate how lecture capture aided student learning Qualitative feedback was also collected in view to further improve the reso...

  8. The Feynman lectures on physics

    International Nuclear Information System (INIS)

    Feynman, R.P.

    1979-01-01

    This set of lectures tries to elucidate from the beginning those features of the quantum mechanics which are most general. The first lectures tackle head on the ideas of a probability amplitude, the interference of amplitudes, the abstract notion of a state, and the superposition and resolution of states - and the Dirac notation is used from the start. In each instance the ideas are introduced together with a detailed discussion of some specific examples - to try to make the physical ideas as real as possible. The time dependence of states including states of definite energy comes next, and the ideas are applied at once to the study of two-state systems. A detailed discussion of the ammonia maser provides the framework for the introduction to radiation absorption and induced transitions. The lectures then go on to consider more complex systems, leading to a discussion of the propagation of electrons in a crystal, and to a rather complete treatment of the quantum mechanics of angular momentum. Our introduction to quantum mechanics ends in Chapter 20 with a discussion of the Schroedinger wave function, its differential equation, and the solution for the hydrogen atom. The last Chapter of this volume is not intended to be a part of the 'course.' It is a 'seminar' on superconductivity and was given in the spirit of some of the entertainment lectures of the first two volumes, with the intent of opening to the students a broader view of the relation of what they were learning to the general culture of physics. Feynman's 'epilogue' serves as the period to the three-volume series [fr

  9. Review of the Accordia Lectures 2014–2015

    Directory of Open Access Journals (Sweden)

    Silvia Amicone

    2015-11-01

    Full Text Available Accordia is an independent research institute that operates in association with the UCL Institute of Archaeology and with the Institute of Classical Studies, the School of Advanced Study, and the University of London. It is dedicated to the promotion and co-ordination of research in all aspects of Italy, from the earliest settlements to the recent past. Accordia organises lectures, research seminars, conferences and exhibitions on aspects of Italian archaeology and history, and publishes a journal, 'Accordia Research Papers', as well as research publications including specialist volumes, conference papers and excavation reports. A subscription is charged for those who want the journal, but all Accordia events are free and open to the public (for more information see the Accordia website: http://www.ucl.ac.uk/accordia/index.htm. The annual lecture series, now in its 27th year, is a regular feature of the academic calendar. Seven lectures take place between October and May, each held at either the UCL Institute of Archaeology or the Institute of Classical Studies (Senate House. The lecturers include both early career and established scholars, and their topics range widely across Italian archaeology, history and art history. The lectures are aimed at both Italian specialists and the general public. This paper offers a review of the 2014–2015 Accordia Lectures. The series was particularly interesting, and covered a wide range of topics related to the archaeology and history of Italy, from prehistoric settlements to the reception of the Etruscan world.

  10. ACADEMIC TRAINING LECTURES QUESTIONNAIRE: SUGGEST AND WIN!

    CERN Multimedia

    Academic Training; Tel. 73127

    2001-01-01

    Time to plan for the 2001-02 lecture series. From today until April 9 you have the chance to give your contribution to improved planning for next year's Academic Training Lectures Series. At the web site: http://wwwinfo/support/survey/academic-training/ you will find questionnaires concerning the following different categories: high energy physics, applied physics, science and society and post-graduate students lectures. Answering the questionnaire will help ensure that the selected topics are as close as possible to your interests. In particular requests and comments from students will be much appreciated. To encourage your contribution, the AT Committee will reward one lucky winner with a small prize, a 50 CHF coupon for a book purchase at CERN bookshop.

  11. Tumour auto-contouring on 2d cine MRI for locally advanced lung cancer: A comparative study.

    Science.gov (United States)

    Fast, Martin F; Eiben, Björn; Menten, Martin J; Wetscherek, Andreas; Hawkes, David J; McClelland, Jamie R; Oelfke, Uwe

    2017-12-01

    Radiotherapy guidance based on magnetic resonance imaging (MRI) is currently becoming a clinical reality. Fast 2d cine MRI sequences are expected to increase the precision of radiation delivery by facilitating tumour delineation during treatment. This study compares four auto-contouring algorithms for the task of delineating the primary tumour in six locally advanced (LA) lung cancer patients. Twenty-two cine MRI sequences were acquired using either a balanced steady-state free precession or a spoiled gradient echo imaging technique. Contours derived by the auto-contouring algorithms were compared against manual reference contours. A selection of eight image data sets was also used to assess the inter-observer delineation uncertainty. Algorithmically derived contours agreed well with the manual reference contours (median Dice similarity index: ⩾0.91). Multi-template matching and deformable image registration performed significantly better than feature-driven registration and the pulse-coupled neural network (PCNN). Neither MRI sequence nor image orientation was a conclusive predictor for algorithmic performance. Motion significantly degraded the performance of the PCNN. The inter-observer variability was of the same order of magnitude as the algorithmic performance. Auto-contouring of tumours on cine MRI is feasible in LA lung cancer patients. Despite large variations in implementation complexity, the different algorithms all have relatively similar performance. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  12. Efficient Active Contour and K-Means Algorithms in Image Segmentation

    Directory of Open Access Journals (Sweden)

    J.R. Rommelse

    2004-01-01

    Full Text Available In this paper we discuss a classic clustering algorithm that can be used to segment images and a recently developed active contour image segmentation model. We propose integrating aspects of the classic algorithm to improve the active contour model. For the resulting CVK and B-means segmentation algorithms we examine methods to decrease the size of the image domain. The CVK method has been implemented to run on parallel and distributed computers. By changing the order of updating the pixels, it was possible to replace synchronous communication with asynchronous communication and subsequently the parallel efficiency is improved.

  13. Contour Tracking Control for the REMUS Autonomous Underwater Vehicle

    National Research Council Canada - National Science Library

    Van Reet, Alan R

    2005-01-01

    In the interest of enhancing the capabilities of autonomous underwater vehicles used in US Naval Operations, controlling vehicle position to follow depth contours presents exciting potential for navigation...

  14. Mediators on human airway smooth muscle.

    Science.gov (United States)

    Armour, C; Johnson, P; Anticevich, S; Ammit, A; McKay, K; Hughes, M; Black, J

    1997-01-01

    1. Bronchial hyperresponsiveness in asthma may be due to several abnormalities, but must include alterations in the airway smooth muscle responsiveness and/or volume. 2. Increased responsiveness of airway smooth muscle in vitro can be induced by certain inflammatory cell products and by induction of sensitization (atopy). 3. Increased airway smooth muscle growth can also be induced by inflammatory cell products and atopic serum. 4. Mast cell numbers are increased in the airways of asthmatics and, in our studies, in airway smooth muscle that is sensitized and hyperresponsive. 5. We propose that there is a relationship between mast cells and airway smooth muscle cells which, once an allergic process has been initiated, results in the development of critical features in the lungs in asthma.

  15. Nuclear fusion-independent smooth muscle differentiation of human adipose-derived stem cells induced by a smooth muscle environment.

    Science.gov (United States)

    Zhang, Rong; Jack, Gregory S; Rao, Nagesh; Zuk, Patricia; Ignarro, Louis J; Wu, Benjamin; Rodríguez, Larissa V

    2012-03-01

    Human adipose-derived stem cells hASC have been isolated and were shown to have multilineage differentiation capacity. Although both plasticity and cell fusion have been suggested as mechanisms for cell differentiation in vivo, the effect of the local in vivo environment on the differentiation of adipose-derived stem cells has not been evaluated. We previously reported the in vitro capacity of smooth muscle differentiation of these cells. In this study, we evaluate the effect of an in vivo smooth muscle environment in the differentiation of hASC. We studied this by two experimental designs: (a) in vivo evaluation of smooth muscle differentiation of hASC injected into a smooth muscle environment and (b) in vitro evaluation of smooth muscle differentiation capacity of hASC exposed to bladder smooth muscle cells. Our results indicate a time-dependent differentiation of hASC into mature smooth muscle cells when these cells are injected into the smooth musculature of the urinary bladder. Similar findings were seen when the cells were cocultured in vitro with primary bladder smooth muscle cells. Chromosomal analysis demonstrated that microenvironment cues rather than nuclear fusion are responsible for this differentiation. We conclude that cell plasticity is present in hASCs, and their differentiation is accomplished in the absence of nuclear fusion. Copyright © 2011 AlphaMed Press.

  16. Advice for New and Student Lecturers on Probability and Statistics

    Science.gov (United States)

    Larsen, Michael D.

    2006-01-01

    Lecture is a common presentation style that gives instructors a lot of control over topics and time allocation, but can limit active student participation and learning. This article presents some ideas to increase the level of student involvement in lecture. The examples and suggestions are based on the author's experience as a senior lecturer for…

  17. Academic Training: Summer Student Lecture Programme

    CERN Multimedia

    2004-01-01

    Main Auditorium, bldg. 500 DATE TIME LECTURER TITLE Monday 12 July 09:15 - 10:00 G. Ross (The Rudolf Peierls Centre for Theoretical Physics & CERN) Fundamental Concepts of Particle Physics (1/6) 10:15 - 11:00 O. Bruening (CERN) Accelerators (1/5) 11:15 - 12:00 L. Di Lella (CERN) Introduction to Particle Physics (4/4) DATE TIME LECTURER TITLE Tuesday 13 July 09:15 - 10:00 G. Ross (The Rudolf Peierls Centre for Theoretical Physics & CERN) Fundamental Concepts of Particle Physics (2/6) 10:15 - 11:00 O. Bruening (CERN) Accelerators (2/5) 11:15 - 12:00 O. Bruening (CERN) G. Ross (The Rudolf Peierls Centre for Theoretical Physics & CERN) Discussion Session DATE TIME LECTURER TITLE Wednesday 14 July 09:15 - 10:00 G. Ross (The Rudolf Peierls Centre for Theoretical Physics & CERN) Fundamental Concepts of Particle Physics (3/6) 10:15 - 11:00 O. Bruening (CERN) Accelerators (3/5) 11:15 - 12:00 O. Bruening (CERN) Accelerators (4/5) 14:00 - ...

  18. Optoelectronic lessons as an interdisciplinary lecture

    Science.gov (United States)

    Wu, Dan; Wu, Maocheng; Gu, Jihua

    2017-08-01

    It is noticed that more and more students in college are passionately curious about the optoelectronic technology, since optoelectronic technology has advanced extremely quickly during the last five years and its applications could be found in a lot of domains. The students who are interested in this area may have different educational backgrounds and their majors cover science, engineering, literature and social science, etc. Our course "History of the Optoelectronic Technology" is set up as an interdisciplinary lecture of the "liberal education" at our university, and is available for all students with different academic backgrounds from any departments of our university. The main purpose of the course is to show the interesting and colorful historical aspects of the development of this technology, so that the students from different departments could absorb the academic nourishment they wanted. There are little complex derivations of physical formulas through the whole lecture, but there are still some difficulties about the lecture which is discussed in this paper.

  19. Contour detection based on nonclassical receptive field inhibition

    NARCIS (Netherlands)

    Grigorescu, Cosmin; Petkov, Nicolai; Westenberg, Michel A.

    We propose a biologically motivated computational step, called nonclassical receptive field (non-CRF) inhibition, more generally surround inhibition or suppression, to improve contour detection in machine vision. Non-CRF inhibition is exhibited by 80% of the orientation-selective neurons in the

  20. Sir Robert Ball: Victorian Astronomer and Lecturer par excellence

    Science.gov (United States)

    Jones, R. I. G.

    2005-12-01

    Between 1875 and 1910 Sir Robert Stawell Ball gave an estimated 2,500 lectures in towns and cities all over the British Isles and abroad. This paper traces his lecturing career from its beginnings in Ireland to the triumphs of the Royal Institution, and on lecture tours in the United States of America. After a period in mathematics and mechanics, he became a populariser of science, especially astronomy, and found fame and fortune among the working classes and the aristocracy. What motivated him to tireless travels is uncertain, but it might have been that it was rewarding, financially and to his reputation. Whatever his motives, contemporary accounts are clear that BallÕs lectures were extremely popular and well-received.

  1. Multiple Active Contours Guided by Differential Evolution for Medical Image Segmentation

    Science.gov (United States)

    Cruz-Aceves, I.; Avina-Cervantes, J. G.; Lopez-Hernandez, J. M.; Rostro-Gonzalez, H.; Garcia-Capulin, C. H.; Torres-Cisneros, M.; Guzman-Cabrera, R.

    2013-01-01

    This paper presents a new image segmentation method based on multiple active contours guided by differential evolution, called MACDE. The segmentation method uses differential evolution over a polar coordinate system to increase the exploration and exploitation capabilities regarding the classical active contour model. To evaluate the performance of the proposed method, a set of synthetic images with complex objects, Gaussian noise, and deep concavities is introduced. Subsequently, MACDE is applied on datasets of sequential computed tomography and magnetic resonance images which contain the human heart and the human left ventricle, respectively. Finally, to obtain a quantitative and qualitative evaluation of the medical image segmentations compared to regions outlined by experts, a set of distance and similarity metrics has been adopted. According to the experimental results, MACDE outperforms the classical active contour model and the interactive Tseng method in terms of efficiency and robustness for obtaining the optimal control points and attains a high accuracy segmentation. PMID:23983809

  2. Multiple Active Contours Guided by Differential Evolution for Medical Image Segmentation

    Directory of Open Access Journals (Sweden)

    I. Cruz-Aceves

    2013-01-01

    Full Text Available This paper presents a new image segmentation method based on multiple active contours guided by differential evolution, called MACDE. The segmentation method uses differential evolution over a polar coordinate system to increase the exploration and exploitation capabilities regarding the classical active contour model. To evaluate the performance of the proposed method, a set of synthetic images with complex objects, Gaussian noise, and deep concavities is introduced. Subsequently, MACDE is applied on datasets of sequential computed tomography and magnetic resonance images which contain the human heart and the human left ventricle, respectively. Finally, to obtain a quantitative and qualitative evaluation of the medical image segmentations compared to regions outlined by experts, a set of distance and similarity metrics has been adopted. According to the experimental results, MACDE outperforms the classical active contour model and the interactive Tseng method in terms of efficiency and robustness for obtaining the optimal control points and attains a high accuracy segmentation.

  3. The Lecture as a Transmedial Pedagogical Form: A Historical Analysis

    Science.gov (United States)

    Friesen, Norm

    2011-01-01

    The lecture has been much maligned as a pedagogical form, yet it persists and even flourishes today in the form of the podcast, the TED talk, and the "smart" lecture hall. This article examines the lecture as a pedagogical genre, as "a site where differences between media are negotiated" (Franzel) as these media coevolve. This examination shows…

  4. Maintaining Students’ Involvement in a Math Lecture Using Countdown Timers

    Directory of Open Access Journals (Sweden)

    Ann Krizzel A. Aban

    2015-12-01

    Full Text Available Involving students in a lecture is an important but not an easy task that every lecturer must encourage. This task becomes even greater in a math class that is composed of eighty to a hundred sixty students. In 2007, the University of the Philippines Los Baños (UPLB started offering some of its basic math courses in lecture-recitation set-up. This shift and many other factors drove most math instructors of UPLB to widely use presentation software, such as the PowerPoint (PPT, to deliver their lectures. The non-stop use of these softwares, however, seems to have negative effects on the students when it comes to maintaining their involvement in a lecture discussion for they tend to be more passive spectators. On the other hand, adding countdown timers strategically on some parts of the discussion seems to lessen such negative effects. This study determined the effectiveness of using countdown timers in maintaining students’ involvement in a lecture of MATH 27 (Analytic Geometry and Calculus II, a course in UPLB commonly taken by sophomore students. Results show that the effectiveness of countdown timers, as perceived by the students, is independent to students’ genders and degree programs, but is dependent to the colleges where the students belong to. Also, some effects of countdown timers are significantly correlated to various data from students’ profiles. It was concluded in the study that the use of countdown timers is effective in maintaining student’s involvement in MATH 27 lectures and might also be useful in other math lecture classes

  5. Automatic contouring of geologic fabric and finite strain data on the unit hyperboloid

    Science.gov (United States)

    Vollmer, Frederick W.

    2018-06-01

    Fabric and finite strain analysis, an integral part of studies of geologic structures and orogenic belts, is commonly done by the analysis of particles whose shapes can be approximated as ellipses. Given a sample of such particles, the mean and confidence intervals of particular parameters can be calculated, however, taking the extra step of plotting and contouring the density distribution can identify asymmetries or modes related to sedimentary fabrics or other factors. A common graphical strain analysis technique is to plot final ellipse ratios, Rf , versus orientations, ϕf on polar Elliott or Rf / ϕ plots to examine the density distribution. The plot may be contoured, however, it is desirable to have a contouring method that is rapid, reproducible, and based on the underlying geometry of the data. The unit hyperboloid, H2 , gives a natural parameter space for two-dimensional strain, and various projections, including equal-area and stereographic, have useful properties for examining density distributions for anisotropy. An index, Ia , is given to quantify the magnitude and direction of anisotropy. Elliott and Rf / ϕ plots can be understood by applying hyperbolic geometry and recognizing them as projections of H2 . These both distort area, however, so the equal-area projection is preferred for examining density distributions. The algorithm presented here gives fast, accurate, and reproducible contours of density distributions calculated directly on H2 . The algorithm back-projects the data onto H2 , where the density calculation is done at regular nodes using a weighting value based on the hyperboloid distribution, which is then contoured. It is implemented as an Octave compatible MATLAB function that plots ellipse data using a variety of projections, and calculates and displays contours of their density distribution on H2 .

  6. Automatic cumulative sums contour detection of FBP-reconstructed multi-object nuclear medicine images.

    Science.gov (United States)

    Protonotarios, Nicholas E; Spyrou, George M; Kastis, George A

    2017-06-01

    The problem of determining the contours of objects in nuclear medicine images has been studied extensively in the past, however most of the analysis has focused on a single object as opposed to multiple objects. The aim of this work is to develop an automated method for determining the contour of multiple objects in positron emission tomography (PET) and single photon emission computed tomography (SPECT) filtered backprojection (FBP) reconstructed images. These contours can be used for computing body edges for attenuation correction in PET and SPECT, as well as for eliminating streak artifacts outside the objects, which could be useful in compressive sensing reconstruction. Contour detection has been accomplished by applying a modified cumulative sums (CUSUM) scheme in the sinogram. Our approach automatically detects all objects in the image, without requiring a priori knowledge of the number of distinct objects in the reconstructed image. This method has been tested in simulated phantoms, such as an image-quality (IQ) phantom and two digital multi-object phantoms, as well as a real NEMA phantom and a clinical thoracic study. For this purpose, a GE Discovery PET scanner was employed. The detected contours achieved root mean square accuracy of 1.14 pixels, 1.69 pixels and 3.28 pixels and a Hausdorff distance of 3.13, 3.12 and 4.50 pixels, for the simulated image-quality phantom PET study, the real NEMA phantom and the clinical thoracic study, respectively. These results correspond to a significant improvement over recent results obtained in similar studies. Furthermore, we obtained an optimal sub-pattern assignment (OSPA) localization error of 0.94 and 1.48, for the two-objects and three-objects simulated phantoms, respectively. Our method performs efficiently for sets of convex objects and hence it provides a robust tool for automatic contour determination with precise results. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. 30 CFR 785.16 - Permits incorporating variances from approximate original contour restoration requirements for...

    Science.gov (United States)

    2010-07-01

    ... approximate original contour restoration requirements for steep slope mining. 785.16 Section 785.16 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR SURFACE COAL... approximate original contour restoration requirements for steep slope mining. (a) The regulatory authority may...

  8. Iterative Method of Regularization with Application of Advanced Technique for Detection of Contours

    International Nuclear Information System (INIS)

    Niedziela, T.; Stankiewicz, A.

    2000-01-01

    This paper proposes a novel iterative method of regularization with application of an advanced technique for detection of contours. To eliminate noises, the properties of convolution of functions are utilized. The method can be accomplished in a simple neural cellular network, which creates the possibility of extraction of contours by automatic image recognition equipment. (author)

  9. Lectures on the mathematics of quantum mechanics I

    CERN Document Server

    Dell'Antonio, Gianfausto

    2015-01-01

    The first volume (General Theory) differs from most textbooks as it emphasizes the mathematical structure and mathematical rigor, while being adapted to the teaching the first semester of an advanced course in Quantum Mechanics (the content of the book are the lectures of courses actually delivered.). It differs also from the very few texts in Quantum Mechanics that give emphasis to the mathematical aspects because this book, being written as Lecture Notes, has the structure of lectures delivered in a course, namely introduction of the problem, outline of the relevant points, mathematical tools needed, theorems, proofs. This makes this book particularly useful for self-study and for instructors in the preparation of a second course in Quantum Mechanics (after a first basic course). With some minor additions it can be used also as a basis of a first course in Quantum Mechanics for students in mathematics curricula. The second part (Selected Topics) are lecture notes of a more advanced course aimed at giving th...

  10. Automatic Camera Control System for a Distant Lecture with Videoing a Normal Classroom.

    Science.gov (United States)

    Suganuma, Akira; Nishigori, Shuichiro

    The growth of a communication network technology enables students to take part in a distant lecture. Although many lectures are conducted in universities by using Web contents, normal lectures using a blackboard are still held. The latter style lecture is good for a teacher's dynamic explanation. A way to modify it for a distant lecture is to…

  11. multiscale smoothing in supervised statistical learning

    Indian Academy of Sciences (India)

    Optimum level of smoothing is chosen based on the entire training sample, while a good choice of smoothing parameter may also depend on the observation to be classified. One may like to assess the strength of evidence in favor of different competing class at different scale of smoothing. In allows only one single ...

  12. Agriculture Lecturers' Perception of the Benefits of Professional ...

    African Journals Online (AJOL)

    The study assessed Agriculture lecturer's perception of the benefits of professional meetings in Nigeria. The study was conducted in Southeast and southsouth geo political zone of Nigeria. Multistage sampling technique was used to select eighty agriculture lecturers for the study. Data were collected with the aid of ...

  13. How to move beyond lecture capture: Pedagogy guide

    NARCIS (Netherlands)

    Moes, S.; Young, C.

    2014-01-01

    This guide gives you an introduction to the phenomenon of lecture capture, the impact it can have, student and teacher attitudes towards this technology in past years, and it also discusses questions like "What is the effect on attendance of students and on the lecture itself?". The guide explains

  14. ANALYTICAL ENGINEERING OF A TELECONTROLLED PILOTLESS AIRCRAFT CONTOUR IN ACCORDANCE WITH GENERALIZED WORK CRITERION

    Directory of Open Access Journals (Sweden)

    A. M. Eromin

    2015-01-01

    Full Text Available The article considers the non­terminal problem for neutral contour of a telecontrolled pilotless aircraft. Optimal control synthesis is provided on the basis of minimization of generalized work functional. The analysis of optimal telecontrolled pilotless aircraft contour is carried out.

  15. ACADEMIC TRAINING LECTURES-QUESTIONNAIRE: SUGGEST AND WIN!

    CERN Multimedia

    Françoise Benz

    2002-01-01

    Its time to plan for the 2002-2003 lecture series. From today until April 26 you have the chance to give your contribution to improved planning for next year's Academic Training Lectures Series. At the web site, you will find questionnaires concerning the following different categories: high energy physics, applied physics, science and society and post-graduate student lectures. Answering the questionnaire will help ensure that the selected topics are as close as possible to your interests. In particular requests and comments from students will be much appreciated. To encourage your contribution, the AT Committee is offering 10 prizes of a self-teach web based training course to people who provide their email address when filling in the questionnaire. The 10 winners will be chosen randomly from the replies received before the closing date.

  16. Mathematical omnibus thirty lectures on classic mathematics

    CERN Document Server

    Fuchs, Dmitry; Fuchs, Dmitry

    2007-01-01

    The book consists of thirty lectures on diverse topics, covering much of the mathematical landscape rather than focusing on one area. The reader will learn numerous results that often belong to neither the standard undergraduate nor graduate curriculum and will discover connections between classical and contemporary ideas in algebra, combinatorics, geometry, and topology. The reader's effort will be rewarded in seeing the harmony of each subject. The common thread in the selected subjects is their illustration of the unity and beauty of mathematics. Most lectures contain exercises, and solutions or answers are given to selected exercises. A special feature of the book is an abundance of drawings (more than four hundred), artwork by an accomplished artist, and about a hundred portraits of mathematicians. Almost every lecture contains surprises for even the seasoned researcher.

  17. Smoothness of limit functors

    Indian Academy of Sciences (India)

    Abstract. Let S be a scheme. Assume that we are given an action of the one dimen- sional split torus Gm,S on a smooth affine S-scheme X. We consider the limit (also called attractor) subfunctor Xλ consisting of points whose orbit under the given action. 'admits a limit at 0'. We show that Xλ is representable by a smooth ...

  18. Segmentation of breast ultrasound images based on active contours using neutrosophic theory.

    Science.gov (United States)

    Lotfollahi, Mahsa; Gity, Masoumeh; Ye, Jing Yong; Mahlooji Far, A

    2018-04-01

    Ultrasound imaging is an effective approach for diagnosing breast cancer, but it is highly operator-dependent. Recent advances in computer-aided diagnosis have suggested that it can assist physicians in diagnosis. Definition of the region of interest before computer analysis is still needed. Since manual outlining of the tumor contour is tedious and time-consuming for a physician, developing an automatic segmentation method is important for clinical application. The present paper represents a novel method to segment breast ultrasound images. It utilizes a combination of region-based active contour and neutrosophic theory to overcome the natural properties of ultrasound images including speckle noise and tissue-related textures. First, due to inherent speckle noise and low contrast of these images, we have utilized a non-local means filter and fuzzy logic method for denoising and image enhancement, respectively. This paper presents an improved weighted region-scalable active contour to segment breast ultrasound images using a new feature derived from neutrosophic theory. This method has been applied to 36 breast ultrasound images. It generates true-positive and false-positive results, and similarity of 95%, 6%, and 90%, respectively. The purposed method indicates clear advantages over other conventional methods of active contour segmentation, i.e., region-scalable fitting energy and weighted region-scalable fitting energy.

  19. v9 = ? The Answer Depends on Your Lecturer

    Science.gov (United States)

    Kontorovich, Igor'

    2016-01-01

    This article is concerned with the approaches to the root concept that lecturers in calculus, linear algebra and complex analysis employ in their instruction. Three highly experienced university lecturers participated in the study. In the individual interviews the participants referred to roots of real numbers, roots of complex numbers, roots as…

  20. SU-E-E-05: Improving Contouring Precision and Consistency for Physicians-In-Training with Simple Lab Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Ma, L; Larson, D A [University of California School of Medicine, San Francisco, CA (United States)

    2015-06-15

    Purpose: Target contouring for high-dose treatments such as radiosurgery of brain metastases is highly critical in eliminating marginal failure and reducing complications as shown by recent clinical studies. In order to improve contouring accuracy and practice consistency for the procedure, we introduced a self-assessed physics lab practice for the physicians-in-training. Methods: A set of commercially acquired high-precision PMMA plastic spheres were randomly embedded in a Styrofoam block and then scanned with the CT/MR via the clinical procedural imaging protocol. A group of first-year physicians-in-training (n=6) from either neurosurgery or radiation oncology department were asked to contour the scanned objects (diameter ranged from 0.4 cm to 3.8 cm). These user-defined contours were then compared with the ideal contour sets of object shape for self assessments to determine the maximum areas of the observed discrepancies and method of improvements. Results: The largest discrepancies from initial practice were consistently found to be located near the extreme longitudinal portions of the target for all the residents. Discrepancy was especially prominent when contouring small objects < 1.0 cm in diameters. For example, the mean volumes rendered from the initial contour data set differed from the ideal data set by 7.7%±6.6% for the participants (p> 0.23 suggesting agreement cannot be established). However, when incorporating a secondary imaging scan such as reconstructed coronal or sagittal images in a repeat practice, the agreement was dramatically improved yielding p<0.02 in agreement with the reference data set for all the participants. Conclusion: A simple physics lab revealed a common pitfall in contouring small metastatic brain tumors for radiosurgical procedures and provided a systematic tool for physicians-in-training in improving their clinical contouring skills. Dr Ma is current a board member of international stereotactic radiosurgical society.

  1. Impostor Syndrome 2014 lecture

    OpenAIRE

    Drew, Joshua

    2014-01-01

    A lecture given at the University of Rochester outlining what the Impostor Syndrome is, as well as how it can impact graduate student success. Other topics include how to build support networks in school as well as picking appropriately scaled projects

  2. The Comparison of Learning Radiographic Extraoral Anatomic Landmarks through Lecture and blended method(Computer-Assisted teaching and Lecture:An interventional Study

    Directory of Open Access Journals (Sweden)

    T ahmine Razi

    2013-05-01

    Full Text Available Introduction: One of the main problems in learning extraoral radiographic anatomic indexes is the long interval between presentation of radiology and human anatomy courses, resulting in forgetting anatomic regions. Therefore, radiographic indexes are formed as complete abstract and transient images in students’ minds; as a result, their learning and retention decrease. The aim of this study was to compare lecture with combination of computer-assisted learning and lecture of extra-oral radiographic landmarks among dental students. Methods: This interventional study was carried out in 2009 on 51 dental students of Tabriz University of Medical Sciences. Students were randomly allocated into two groups. The first group was taught through a teaching method which involved lectures in the classroom. In the second group, a CD was given to the students. The teaching was accomplished through presentation using skull. Six months after finishing the teaching, both groups took a similar test for evaluation of long term learning. The data was analyzed by SPSS 16 using U Mann-Whitney test. Results: There was no significant differences in the mean scores between the two groups in the first exam after teaching (P=0.13, yet it was significant in the second exam (regarding retention (P=0.006, and average of non-traditional teaching method group (20.89±10.23 was higher than that of lecture group (13.48±6.39. Conclusion: Based on the results, non-traditional technique of teaching was not more effective than the lecture in short-term learning but in longterm learning, non-traditional technique was more effective than the lecture.

  3. Strain-induced fermi contour anisotropy of GaAs 2D holes.

    Science.gov (United States)

    Shabani, J; Shayegan, M; Winkler, R

    2008-03-07

    We report measurements of magnetoresistance commensurability peaks, induced by a square array of antidots, in GaAs (311)A two-dimensional holes as a function of applied in-plane strain. The data directly probe the shapes of the Fermi contours of the two spin subbands that are split thanks to the spin-orbit interaction and strain. The experimental results are in quantitative agreement with the predictions of accurate energy band calculations, and reveal that the majority spin subband has a severely distorted Fermi contour whose anisotropy can be tuned with strain.

  4. Low dose CBCT reconstruction via prior contour based total variation (PCTV) regularization: a feasibility study

    Science.gov (United States)

    Chen, Yingxuan; Yin, Fang-Fang; Zhang, Yawei; Zhang, You; Ren, Lei

    2018-04-01

    Purpose: compressed sensing reconstruction using total variation (TV) tends to over-smooth the edge information by uniformly penalizing the image gradient. The goal of this study is to develop a novel prior contour based TV (PCTV) method to enhance the edge information in compressed sensing reconstruction for CBCT. Methods: the edge information is extracted from prior planning-CT via edge detection. Prior CT is first registered with on-board CBCT reconstructed with TV method through rigid or deformable registration. The edge contours in prior-CT is then mapped to CBCT and used as the weight map for TV regularization to enhance edge information in CBCT reconstruction. The PCTV method was evaluated using extended-cardiac-torso (XCAT) phantom, physical CatPhan phantom and brain patient data. Results were compared with both TV and edge preserving TV (EPTV) methods which are commonly used for limited projection CBCT reconstruction. Relative error was used to calculate pixel value difference and edge cross correlation was defined as the similarity of edge information between reconstructed images and ground truth in the quantitative evaluation. Results: compared to TV and EPTV, PCTV enhanced the edge information of bone, lung vessels and tumor in XCAT reconstruction and complex bony structures in brain patient CBCT. In XCAT study using 45 half-fan CBCT projections, compared with ground truth, relative errors were 1.5%, 0.7% and 0.3% and edge cross correlations were 0.66, 0.72 and 0.78 for TV, EPTV and PCTV, respectively. PCTV is more robust to the projection number reduction. Edge enhancement was reduced slightly with noisy projections but PCTV was still superior to other methods. PCTV can maintain resolution while reducing the noise in the low mAs CatPhan reconstruction. Low contrast edges were preserved better with PCTV compared with TV and EPTV. Conclusion: PCTV preserved edge information as well as reduced streak artifacts and noise in low dose CBCT reconstruction

  5. Calcium dynamics in vascular smooth muscle

    OpenAIRE

    Amberg, Gregory C.; Navedo, Manuel F.

    2013-01-01

    Smooth muscle cells are ultimately responsible for determining vascular luminal diameter and blood flow. Dynamic changes in intracellular calcium are a critical mechanism regulating vascular smooth muscle contractility. Processes influencing intracellular calcium are therefore important regulators of vascular function with physiological and pathophysiological consequences. In this review we discuss the major dynamic calcium signals identified and characterized in vascular smooth muscle cells....

  6. Topical Articles: Attention during Lectures--Beyond Ten Minutes

    Science.gov (United States)

    Wilson, Karen; Korn, James H.

    2007-01-01

    Many authors claim that students' attention declines approximately 10 to 15 min into lectures. To evaluate this claim, we reviewed several types of studies including studies of student note taking, observations of students during lectures, and self-reports of student attention, as well as studies using physiological measures of attention. We found…

  7. Automatic Online Lecture Highlighting Based on Multimedia Analysis

    Science.gov (United States)

    Che, Xiaoyin; Yang, Haojin; Meinel, Christoph

    2018-01-01

    Textbook highlighting is widely considered to be beneficial for students. In this paper, we propose a comprehensive solution to highlight the online lecture videos in both sentence- and segment-level, just as is done with paper books. The solution is based on automatic analysis of multimedia lecture materials, such as speeches, transcripts, and…

  8. Human resources management and lecturer's job satisfaction in ...

    African Journals Online (AJOL)

    The study examines the extent to which the management of human resources by the administrators influence lecturers' job satisfaction in tertiary institutions in Akwa Ibom and Cross River States, Nigeria. The ex-post-facto research design was used for the study. The population of the study was 2286 lecturers from nine (9) ...

  9. College Students' Perceptions of the Traditional Lecture Method

    Science.gov (United States)

    Covill, Amy E.

    2011-01-01

    Fifty-one college students responded to survey questions regarding their perceptions of the traditional lecture method of instruction that they received in a 200-level psychology course. At a time when many professors are being encouraged to use active learning methods instead of lectures, it is important to consider the students' perspective. Do…

  10. Free-convective flow of fluid in a thin porous contour and geothermal anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Magomedbekov Kh.G.; Ramazanov, M.M.; Vagabov, M.V.

    1996-01-24

    The problem of free convection in a thin porous contour, placed in uniform impermeable massif is considered. The approximate analitical solution of conjugate problem is obtained. The critical Rayleigh number is determined, by exceeding of which the steady fluid circulation in an annulus is established. The computations of abnormal heat flow near surface are carried out, stipulated by thermoconvection in a contour.

  11. Directional harmonic theory: a computational Gestalt model to account for illusory contour and vertex formation.

    Science.gov (United States)

    Lehar, Steven

    2003-01-01

    Visual illusions and perceptual grouping phenomena offer an invaluable tool for probing the computational mechanism of low-level visual processing. Some illusions, like the Kanizsa figure, reveal illusory contours that form edges collinear with the inducing stimulus. This kind of illusory contour has been modeled by neural network models by way of cells equipped with elongated spatial receptive fields designed to detect and complete the collinear alignment. There are, however, other illusory groupings which are not so easy to account for in neural network terms. The Ehrenstein illusion exhibits an illusory contour that forms a contour orthogonal to the stimulus instead of collinear with it. Other perceptual grouping effects reveal illusory contours that exhibit a sharp corner or vertex, and still others take the form of vertices defined by the intersection of three, four, or more illusory contours that meet at a point. A direct extension of the collinear completion models to account for these phenomena tends towards a combinatorial explosion, because it would suggest cells with specialized receptive fields configured to perform each of those completion types, each of which would have to be replicated at every location and every orientation across the visual field. These phenomena therefore challenge the adequacy of the neural network approach to account for these diverse perceptual phenomena. I have proposed elsewhere an alternative paradigm of neurocomputation in the harmonic resonance theory (Lehar 1999, see website), whereby pattern recognition and completion are performed by spatial standing waves across the neural substrate. The standing waves perform a computational function analogous to that of the spatial receptive fields of the neural network approach, except that, unlike that paradigm, a single resonance mechanism performs a function equivalent to a whole array of spatial receptive fields of different spatial configurations and of different orientations

  12. Resident training for eclampsia and magnesium toxicity management: simulation or traditional lecture?

    Science.gov (United States)

    Fisher, Nelli; Bernstein, Peter S; Satin, Andrew; Pardanani, Setul; Heo, Hye; Merkatz, Irwin R; Goffman, Dena

    2010-10-01

    To compare eclampsia and magnesium toxicity management among residents randomly assigned to lecture or simulation-based education. Statified by year, residents (n = 38) were randomly assigned to 3 educational intervention groups: Simulation→Lecture, Simulation, and Lecture. Postintervention simulations were performed for all and scored using standardized lists. Maternal, fetal, eclampsia management, and magnesium toxcity scores were assigned. Mann-Whitney U, Wilcoxon rank sum and χ(2) tests were used for analysis. Postintervention maternal (16 and 15 vs 12; P < .05) and eclampsia (19 vs 16; P < .05) scores were significantly better in simulation based compared with lecture groups. Postintervention magnesium toxcitiy and fetal scores were not different among groups. Lecture added to simulation did not lead to incremental benefit when eclampsia scores were compared between Simulation→Lecture and Simulation (19 vs 19; P = nonsignificant). Simulation training is superior to traditional lecture alone for teaching crucial skills for the optimal management of both eclampsia and magnesium toxicity, 2 life-threatening obstetric emergencies. Published by Mosby, Inc.

  13. A Brief History of the Lecture: A Multi-Media Analysis

    Directory of Open Access Journals (Sweden)

    Norm Friesen

    2014-09-01

    Full Text Available The lecture has been much maligned as a pedagogical form. It has been denigrated as a «hot ‎medium» that has long been «superseded» by the cooler dialogical and televisual forms. Yet the lecture ‎persists and even flourishes today in the form of the podcast, the TED Talk, Kahn Academy and the «smart» ‎lecture hall (outfitted with audio, video and student feedback technologies. This persistence ‎should lead us to re-evaluate both the lecture and the role of the media that have been related to it over time. This paper examines the lecture as a site of intersecting media, as «a site where differences between media are negotiated» as these media ‎evolve (Franzel 2010. This study shows the lecture as bridging oral ‎communication with writing and newer media technologies, rather than as being superseded ‎by newer electronic and digital forms. The result is a remarkably adaptable and robust form ‎that combines textual record and ephemeral event. It is that is capable of addressing a range of ‎different demands and circumstances, both in terms of classroom pragmatics and more abstractly, of the circulation of knowledge itself. The Web, which ‎brings multiple media together with new and established forms and genres, presents fertile ‎grounds for the continuation and revitalization of the lecture as a dominant pedagogical form.

  14. Opening lecture

    International Nuclear Information System (INIS)

    Thomas, J.B.

    1997-01-01

    The opening lecture on the results of fifty years in the nuclear energy field, deals with the main principles underlying the CEA policy concerning the fission nuclear energy transformation, i.e. the design of a nuclear industry that is a safe, high-performance and reliable source of electric power, the development of an adaptive power generation tool with the capacity to progress according to new constraints, and the necessary anticipation for preparing to the effects of the next 50 year technological leaps

  15. Lectures on dark matter

    International Nuclear Information System (INIS)

    Seljak, U.

    2001-01-01

    These lectures concentrate on evolution and generation of dark matter perturbations. The purpose of the lectures is to present, in a systematic way, a comprehensive review of the cosmological parameters that can lead to observable effects in the dark matter clustering properties. We begin by reviewing the relativistic linear perturbation theory formalism. We discuss the gauge issue and derive Einstein's and continuity equations for several popular gauge choices. We continue by developing fluid equations for cold dark matter and baryons and Boltzmann equations for photons, massive and massless neutrinos. We then discuss the generation of initial perturbations by the process of inflation and the parameters of that process that can be extracted from the observations. Finally we discuss evolution of perturbations in various regimes and the imprint of the evolution on the dark matter power spectrum both in the linear and in the nonlinear regime. (author)

  16. Lectures on dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Seljak, U [Department of Physics, Princeton University, Princeton, NJ (United States)

    2001-11-15

    These lectures concentrate on evolution and generation of dark matter perturbations. The purpose of the lectures is to present, in a systematic way, a comprehensive review of the cosmological parameters that can lead to observable effects in the dark matter clustering properties. We begin by reviewing the relativistic linear perturbation theory formalism. We discuss the gauge issue and derive Einstein's and continuity equations for several popular gauge choices. We continue by developing fluid equations for cold dark matter and baryons and Boltzmann equations for photons, massive and massless neutrinos. We then discuss the generation of initial perturbations by the process of inflation and the parameters of that process that can be extracted from the observations. Finally we discuss evolution of perturbations in various regimes and the imprint of the evolution on the dark matter power spectrum both in the linear and in the nonlinear regime. (author)

  17. Lecture Notes in Statistics. 3rd Semester

    DEFF Research Database (Denmark)

    The lecture note is prepared to meet the requirements for the 3rd semester course in statistics at the Aarhus School of Business. It focuses on multiple regression models, analysis of variance, and log-linear models.......The lecture note is prepared to meet the requirements for the 3rd semester course in statistics at the Aarhus School of Business. It focuses on multiple regression models, analysis of variance, and log-linear models....

  18. PDF Lecture Materials for Online and ``Flipped'' Format Astronomy Courses

    Science.gov (United States)

    Kary, D. M.; Eisberg, J.

    2013-04-01

    Online astronomy courses typically rely on students reading the textbook and/or a set of text-based lecture notes to replace the “lecture” material. However, many of our students report that this is much less engaging than in-person lectures, especially given the amount of interactive work such as “think-pair-share” problems done in many astronomy classes. Students have similarly criticized direct lecture-capture. To address this, we have developed a set of PowerPoint-style presentations with embedded lecture audio combined with prompts for student interaction including think-pair-share questions. These are formatted PDF packages that can be used on a range of different computers using free software. The presentations are first developed using Microsoft PowerPoint software. Audio recordings of scripted lectures are then synchronized with the presentations and the entire package is converted to PDF using Adobe Presenter. This approach combines the ease of editing that PowerPoint provides along with the platform-independence of PDF. It's easy to add, remove, or edit individual slides as needed, and PowerPoint supports internal links so that think-pair-share questions can be inserted with links to feedback based on the answers selected. Modern PDF files support animated visuals with synchronized audio and they can be read using widely available free software. Using these files students in an online course can get many of the benefits of seeing and hearing the course material presented in an in-person lecture format. Students needing extra help in traditional lecture classes can use these presentations to help review the materials covered in lecture. Finally, the presentations can be used in a “flipped” format in which students work through the presentations outside of class time while spending the “lecture” time on in-class interaction.

  19. Effect of lecture instruction on student performance on qualitative questions

    Science.gov (United States)

    Heron, Paula R. L.

    2015-06-01

    The impact of lecture instruction on student conceptual understanding in physics has been the subject of research for several decades. Most studies have reported disappointingly small improvements in student performance on conceptual questions despite direct instruction on the relevant topics. These results have spurred a number of attempts to improve learning in physics courses through new curricula and instructional techniques. This paper contributes to the research base through a retrospective analysis of 20 randomly selected qualitative questions on topics in kinematics, dynamics, electrostatics, waves, and physical optics that have been given in introductory calculus-based physics at the University of Washington over a period of 15 years. In some classes, questions were administered after relevant lecture instruction had been completed; in others, it had yet to begin. Simple statistical tests indicate that the average performance of the "after lecture" classes was significantly better than that of the "before lecture" classes for 11 questions, significantly worse for two questions, and indistinguishable for the remaining seven. However, the classes had not been randomly assigned to be tested before or after lecture instruction. Multiple linear regression was therefore conducted with variables (such as class size) that could plausibly lead to systematic differences in performance and thus obscure (or artificially enhance) the effect of lecture instruction. The regression models support the results of the simple tests for all but four questions. In those cases, the effect of lecture instruction was reduced to a nonsignificant level, or increased to a significant, negative level when other variables were considered. Thus the results provide robust evidence that instruction in lecture can increase student ability to give correct answers to conceptual questions but does not necessarily do so; in some cases it can even lead to a decrease.

  20. Lecture Videos in Online Courses: A Follow-Up

    Science.gov (United States)

    Evans, Heather K.; Cordova, Victoria

    2015-01-01

    In a recent study regarding online lecture videos, Evans (2014) shows that lecture videos are not superior to still slides. Using two Introduction to American Government courses, taught in a 4-week summer session, she shows that students in a non-video course had higher satisfaction with the course and instructor and performed better on exams than…

  1. Just Do It: Flipped Lecture, Determinants and Debate

    Science.gov (United States)

    Kensington-Miller, Barbara; Novak, Julia; Evans, Tanya

    2016-01-01

    This paper describes a case study of two pure mathematicians who flipped their lecture to teach matrix determinants in two large mathematics service courses (one at Stage I and the other at Stage II). The purpose of the study was to transform the passive lecture into an active learning opportunity and to introduce valuable mathematical skills,…

  2. Quality of life long-term after body contouring surgery following bariatric surgery: sustained improvement after 7 years.

    Science.gov (United States)

    van der Beek, Eva S J; Geenen, Rinie; de Heer, Francine A G; van der Molen, Aebele B Mink; van Ramshorst, Bert

    2012-11-01

    Bariatric surgery for morbid obesity results in massive weight loss and improvement of health and quality of life. A downside of the major weight loss is the excess of overstretched skin, which may influence the patient's quality of life by causing functional and aesthetic problems. The purpose of the current study was to evaluate the patient's quality of life long-term after body contouring following bariatric surgery. Quality of life was measured with the Obesity Psychosocial State Questionnaire in 33 post-bariatric surgery patients 7.2 years (range, 3.2 to 13.3 years) after body contouring surgery. Data were compared with previous assessments 4.1 years (range, 0.7 to 9.2 years) after body contouring surgery of the quality of life at that time and before body contouring surgery. Compared with appraisals of quality of life before body contouring surgery, a significant, mostly moderate to large, sustained improvement of quality of life was observed in post-bariatric surgery patients 7.2 years after body contouring surgery in six of the seven psychosocial domains. A small deterioration occurred between 4.1- and 7.2-year follow-up on two of the seven domains except for the domain efficacy toward eating, which showed a significant improvement. At 7-year follow-up, 18 patients (55 percent) were satisfied with the result of body contouring surgery. This study indicates a sustained quality-of-life improvement in post-bariatric surgery patients after body contouring surgery. This suggests the importance of including reconstructive surgery as a component in the multidisciplinary approach in the surgical treatment of morbid obesity. Therapeutic, IV.

  3. Development and Validation of Consensus Contouring Guidelines for Adjuvant Radiation Therapy for Bladder Cancer After Radical Cystectomy

    Energy Technology Data Exchange (ETDEWEB)

    Baumann, Brian C. [Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania (United States); Bosch, Walter R. [Washington University in St. Louis, St. Louis, Missouri (United States); Bahl, Amit [University Hospitals Bristol NHS Foundation Trust, Bristol (United Kingdom); Birtle, Alison J. [Royal Preston Hospital, Preston (United Kingdom); Breau, Rodney H. [University of Ottawa, Ottawa, Ontario (Canada); Challapalli, Amarnath [University Hospitals Bristol NHS Foundation Trust, Bristol (United Kingdom); Chang, Albert J. [University of California San Francisco, San Francisco, California (United States); Choudhury, Ananya [Department of Clinical Oncology, The Christie NHS Foundation Trust, Manchester (United Kingdom); The University of Manchester, Manchester Academic Heath Science Centre, Manchester (United Kingdom); Daneshmand, Sia [University of Southern California, Los Angeles, California (United States); El-Gayed, Ali [Saskatoon Cancer Centre, Saskatoon (Canada); Feldman, Adam [Massachusetts General Hospital, Boston, Massachusetts (United States); Finkelstein, Steven E. [Cancer Treatment Centers of America, Tulsa, Oklahoma (United States); Guzzo, Thomas J. [Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania (United States); Hilman, Serena [University Hospitals Bristol NHS Foundation Trust, Bristol (United Kingdom); Jani, Ashesh [Emory University, Atlanta, Georgia (United States); Malkowicz, S. Bruce [Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania (United States); Mantz, Constantine A. [21st Century Oncology, Scottsdale, Arizona (United States); 21st Century Oncology, Fort Myers, Florida (United States); Master, Viraj [Emory University, Atlanta, Georgia (United States); Mitra, Anita V. [University College London Hospital, London (United Kingdom); Murthy, Vedang [Tata Memorial Center, Mumbai (India); and others

    2016-09-01

    Purpose: To develop multi-institutional consensus clinical target volumes (CTVs) and organs at risk (OARs) for male and female bladder cancer patients undergoing adjuvant radiation therapy (RT) in clinical trials. Methods and Materials: We convened a multidisciplinary group of bladder cancer specialists from 15 centers and 5 countries. Six radiation oncologists and 7 urologists participated in the development of the initial contours. The group proposed initial language for the CTVs and OARs, and each radiation oncologist contoured them on computed tomography scans of a male and female cystectomy patient with input from ≥1 urologist. On the basis of the initial contouring, the group updated its CTV and OAR descriptions. The cystectomy bed, the area of greatest controversy, was contoured by another 6 radiation oncologists, and the cystectomy bed contouring language was again updated. To determine whether the revised language produced consistent contours, CTVs and OARs were redrawn by 6 additional radiation oncologists. We evaluated their contours for level of agreement using the Landis-Koch interpretation of the κ statistic. Results: The group proposed that patients at elevated risk for local-regional failure with negative margins should be treated to the pelvic nodes alone (internal/external iliac, distal common iliac, obturator, and presacral), whereas patients with positive margins should be treated to the pelvic nodes and cystectomy bed. Proposed OARs included the rectum, bowel space, bone marrow, and urinary diversion. Consensus language describing the CTVs and OARs was developed and externally validated. The revised instructions were found to produce consistent contours. Conclusions: Consensus descriptions of CTVs and OARs were successfully developed and can be used in clinical trials of adjuvant radiation therapy for bladder cancer.

  4. Field-level financial assessment of contour prairie strips for enhancement of environmental quality.

    Science.gov (United States)

    Tyndall, John C; Schulte, Lisa A; Liebman, Matthew; Helmers, Matthew

    2013-09-01

    The impacts of strategically located contour prairie strips on sediment and nutrient runoff export from watersheds maintained under an annual row crop production system have been studied at a long-term research site in central Iowa. Data from 2007 to 2011 indicate that the contour prairie strips utilized within row crop-dominated landscapes have greater than proportionate and positive effects on the functioning of biophysical systems. Crop producers and land management agencies require comprehensive information about the Best Management Practices with regard to performance efficacy, operational/management parameters, and the full range of financial parameters. Here, a farm-level financial model assesses the establishment, management, and opportunity costs of contour prairie strips within cropped fields. Annualized, depending on variable opportunity costs the 15-year present value cost of utilizing contour prairie strips ranges from $590 to $865 ha(-1) year(-1) ($240-$350 ac(-1) year(-1)). Expressed in the context of "treatment area" (e.g., in this study 1 ha of prairie treats 10 ha of crops), the costs of contour prairie strips can also be viewed as $59 to about $87 per treated hectare ($24-$35 ac(-1)). If prairie strips were under a 15-year CRP contract, total per acre cost to farmers would be reduced by over 85 %. Based on sediment, phosphorus, and nitrogen export data from the related field studies and across low, medium, and high land rent scenarios, a megagram (Mg) of soil retained within the watershed costs between $7.79 and $11.46 mg(-1), phosphorus retained costs between $6.97 and $10.25 kg(-1), and nitrogen retained costs between $1.59 and $2.34 kg(-1). Based on overall project results, contour prairie strips may well become one of the key conservation practices used to sustain US Corn Belt agriculture in the decades to come.

  5. Pseudo-Hermitian description of PT-symmetric systems defined on a complex contour

    International Nuclear Information System (INIS)

    Mostafazadeh, Ali

    2005-01-01

    We describe a method that allows for a practical application of the theory of pseudo-Hermitian operators to PT-symmetric systems defined on a complex contour. We apply this method to study the Hamiltonians H = p 2 + x 2 (ix) ν with ν ε (-2, ∞) that are defined along the corresponding anti-Stokes lines. In particular, we reveal the intrinsic non-Hermiticity of H for the cases that ν is an even integer, so that H p 2 ± x 2+ν , and give a proof of the discreteness of the spectrum of H for all ν ε (-2, ∞). Furthermore, we study the consequences of defining a square-well Hamiltonian on a wedge-shaped complex contour. This yields a PT-symmetric system with a finite number of real eigenvalues. We present a comprehensive analysis of this system within the framework of pseudo-Hermitian quantum mechanics. We also outline a direct pseudo-Hermitian treatment of PT-symmetric systems defined on a complex contour which clarifies the underlying mathematical structure of the formulation of PT-symmetric quantum mechanics based on the charge-conjugation operator. Our results provide conclusive evidence that pseudo-Hermitian quantum mechanics provides a complete description of general PT-symmetric systems regardless of whether they are defined along the real line or a complex contour

  6. Effect of smoothing on robust chaos.

    Science.gov (United States)

    Deshpande, Amogh; Chen, Qingfei; Wang, Yan; Lai, Ying-Cheng; Do, Younghae

    2010-08-01

    In piecewise-smooth dynamical systems, situations can arise where the asymptotic attractors of the system in an open parameter interval are all chaotic (e.g., no periodic windows). This is the phenomenon of robust chaos. Previous works have established that robust chaos can occur through the mechanism of border-collision bifurcation, where border is the phase-space region where discontinuities in the derivatives of the dynamical equations occur. We investigate the effect of smoothing on robust chaos and find that periodic windows can arise when a small amount of smoothness is present. We introduce a parameter of smoothing and find that the measure of the periodic windows in the parameter space scales linearly with the parameter, regardless of the details of the smoothing function. Numerical support and a heuristic theory are provided to establish the scaling relation. Experimental evidence of periodic windows in a supposedly piecewise linear dynamical system, which has been implemented as an electronic circuit, is also provided.

  7. DEVELOPMENT OF VISUALLY GUIDED BEHAVIOR REQUIRES ORIENTED CONTOURS

    NARCIS (Netherlands)

    BRENNER, E; CORNELISSEN, FW

    1992-01-01

    Kittens do not learn to use visual information to guide their behaviour if they are deprived of the optic flow that accompanies their own movements. We show that the optic flow that is required for developing visually guided behaviour is derived from changes in contour orientations, rather than from

  8. Anatomically contoured plates for fixation of rib fractures.

    Science.gov (United States)

    Bottlang, Michael; Helzel, Inga; Long, William B; Madey, Steven

    2010-03-01

    : Intraoperative contouring of long bridging plates for stabilization of flail chest injuries is difficult and time consuming. This study implemented for the first time biometric parameters to derive anatomically contoured rib plates. These plates were tested on a range of cadaveric ribs to quantify plate fit and to extract a best-fit plating configuration. : Three left and three right rib plates were designed, which accounted for anatomic parameters required when conforming a plate to the rib surface. The length lP over which each plate could trace the rib surface was evaluated on 109 cadaveric ribs. For each rib level 3-9, the plate design with the highest lP value was extracted to determine a best-fit plating configuration. Furthermore, the characteristic twist of rib surfaces was measured on 49 ribs to determine the surface congruency of anatomic plates with a constant twist. : The tracing length lP of the best-fit plating configuration ranged from 12.5 cm to 14.7 cm for ribs 3-9. The corresponding range for standard plates was 7.1-13.7 cm. The average twist of ribs over 8-cm, 12-cm, and 16-cm segments was 8.3 degrees, 20.6 degrees, and 32.7 degrees, respectively. The constant twist of anatomic rib plates was not significantly different from the average rib twist. : A small set of anatomic rib plates can minimize the need for intraoperative plate contouring for fixation of ribs 3-9. Anatomic rib plates can therefore reduce the time and complexity of flail chest stabilization and facilitate spanning of flail segments with long plates.

  9. Smooth surfaces from rational bilinear patches

    KAUST Repository

    Shi, Ling

    2014-01-01

    Smooth freeform skins from simple panels constitute a challenging topic arising in contemporary architecture. We contribute to this problem area by showing how to approximate a negatively curved surface by smoothly joined rational bilinear patches. The approximation problem is solved with help of a new computational approach to the hyperbolic nets of Huhnen-Venedey and Rörig and optimization algorithms based on it. We also discuss its limits which lie in the topology of the input surface. Finally, freeform deformations based on Darboux transformations are used to generate smooth surfaces from smoothly joined Darboux cyclide patches; in this way we eliminate the restriction to surfaces with negative Gaussian curvature. © 2013 Elsevier B.V.

  10. Automatic contour propagation using deformable image registration to determine delivered dose to spinal cord in head-and-neck cancer radiotherapy

    Science.gov (United States)

    Yeap, P. L.; Noble, D. J.; Harrison, K.; Bates, A. M.; Burnet, N. G.; Jena, R.; Romanchikova, M.; Sutcliffe, M. P. F.; Thomas, S. J.; Barnett, G. C.; Benson, R. J.; Jefferies, S. J.; Parker, M. A.

    2017-08-01

    To determine delivered dose to the spinal cord, a technique has been developed to propagate manual contours from kilovoltage computed-tomography (kVCT) scans for treatment planning to megavoltage computed-tomography (MVCT) guidance scans. The technique uses the Elastix software to perform intensity-based deformable image registration of each kVCT scan to the associated MVCT scans. The registration transform is then applied to contours of the spinal cord drawn manually on the kVCT scan, to obtain contour positions on the MVCT scans. Different registration strategies have been investigated, with performance evaluated by comparing the resulting auto-contours with manual contours, drawn by oncologists. The comparison metrics include the conformity index (CI), and the distance between centres (DBC). With optimised registration, auto-contours generally agree well with manual contours. Considering all 30 MVCT scans for each of three patients, the median CI is 0.759 +/- 0.003 , and the median DBC is (0.87 +/- 0.01 ) mm. An intra-observer comparison for the same scans gives a median CI of 0.820 +/- 0.002 and a DBC of (0.64 +/- 0.01 ) mm. Good levels of conformity are also obtained when auto-contours are compared with manual contours from one observer for a single MVCT scan for each of 30 patients, and when they are compared with manual contours from six observers for two MVCT scans for each of three patients. Using the auto-contours to estimate organ position at treatment time, a preliminary study of 33 patients who underwent radiotherapy for head-and-neck cancers indicates good agreement between planned and delivered dose to the spinal cord.

  11. Automatic contour propagation using deformable image registration to determine delivered dose to spinal cord in head-and-neck cancer radiotherapy.

    Science.gov (United States)

    Yeap, P L; Noble, D J; Harrison, K; Bates, A M; Burnet, N G; Jena, R; Romanchikova, M; Sutcliffe, M P F; Thomas, S J; Barnett, G C; Benson, R J; Jefferies, S J; Parker, M A

    2017-07-12

    To determine delivered dose to the spinal cord, a technique has been developed to propagate manual contours from kilovoltage computed-tomography (kVCT) scans for treatment planning to megavoltage computed-tomography (MVCT) guidance scans. The technique uses the Elastix software to perform intensity-based deformable image registration of each kVCT scan to the associated MVCT scans. The registration transform is then applied to contours of the spinal cord drawn manually on the kVCT scan, to obtain contour positions on the MVCT scans. Different registration strategies have been investigated, with performance evaluated by comparing the resulting auto-contours with manual contours, drawn by oncologists. The comparison metrics include the conformity index (CI), and the distance between centres (DBC). With optimised registration, auto-contours generally agree well with manual contours. Considering all 30 MVCT scans for each of three patients, the median CI is [Formula: see text], and the median DBC is ([Formula: see text]) mm. An intra-observer comparison for the same scans gives a median CI of [Formula: see text] and a DBC of ([Formula: see text]) mm. Good levels of conformity are also obtained when auto-contours are compared with manual contours from one observer for a single MVCT scan for each of 30 patients, and when they are compared with manual contours from six observers for two MVCT scans for each of three patients. Using the auto-contours to estimate organ position at treatment time, a preliminary study of 33 patients who underwent radiotherapy for head-and-neck cancers indicates good agreement between planned and delivered dose to the spinal cord.

  12. Comparison of Internet versus lecture instructional methods for teaching nursing research.

    Science.gov (United States)

    Woo, M A; Kimmick, J V

    2000-01-01

    Although many higher education programs are using the Internet to teach classes, there are few published reports on the effectiveness of this method on test scores or student satisfaction. The purpose of this study was to compare test and student satisfaction scores of graduate nursing students who take a nursing research course via the Internet with those of students who take the same course via traditional lecture instruction. In addition, student technical support use and Internet student lecture attendance also were examined. A total of 97 students (Internet, 44; lectures, 53) participated. There were no significant differences in test scores and overall course student satisfaction (P > .05). However, the Internet students reported significantly higher (P = .04) stimulation of learning compared with the traditional lecture students. Technical support use by the Internet students was high initially and was related to software problems. Of interest were the large proportion of Internet students (73 percent) who attended at least 3 of the 10 lectures. Use of the Internet to teach graduate-level nursing research can provide comparable learning and student satisfaction to traditional lecture instructional methods.

  13. Effects of three types of lecture notes on medical student achievement.

    Science.gov (United States)

    Russell, I J; Caris, T N; Harris, G D; Hendricson, W D

    1983-08-01

    Two parallel studies were conducted with junior medical students to determine what influence the forms of lecture notes would have on learning. The three types of notes given to the students were: a comprehensive manuscript of the lecture containing text, tables, and figures; a partial handout which included some illustrations but required substantial annotation by the students; and a skeleton outline containing no data from the lecture. The students' knowledge about the subject was measured before the lecture, immediately after the lecture, two to four weeks later, and approximately three months later. The students' responses to questionnaires indicated a strong preference for very detained handouts as essential to preparation for examinations. By contract, the students' performances on tests generally were better for those who had received the partial or skeleton handout formats. This was particularly true for information presented during the last quarter of each lecture, when learning efficiency of the skeleton handout group increased while the other two handout groups exhibited learning fatigue. It was concluded that learning by medical students was improved when they recorded notes in class.

  14. Memory for pure tone sequences without contour.

    Science.gov (United States)

    Lefebvre, Christine; Jolicœur, Pierre

    2016-06-01

    We presented pure tones interspersed with white noise sounds to disrupt contour perception in an acoustic short-term memory (ASTM) experiment during which we recorded the electroencephalogram. The memory set consisted of seven stimuli, 0, 1, 2, 3, or 4 of which were to-be-remembered tones. We estimated each participant׳s capacity, K, for each set size and measured the amplitude of the SAN (sustained anterior negativity, an ERP related to acoustic short-term memory). We correlated their K slopes with their SAN amplitude slopes as a function of set size, and found a significant link between performance and the SAN: a larger increase in SAN amplitude was linked with a larger number of stimuli maintained in ASTM. The SAN decreased in amplitude in the later portion of the silent retention interval, but the correlation between the SAN and capacity remained strong. These results show the SAN is not an index of contour but rather an index of the maintenance of individual objects in STM. This article is part of a Special Issue entitled SI: Auditory working memory. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. The interrupted learner: How distractions during live and video lectures influence learning outcomes.

    Science.gov (United States)

    Zureick, Andrew H; Burk-Rafel, Jesse; Purkiss, Joel A; Hortsch, Michael

    2017-11-27

    New instructional technologies have been increasingly incorporated into the medical school learning environment, including lecture video recordings as a substitute for live lecture attendance. The literature presents varying conclusions regarding how this alternative experience impacts students' academic success. Previously, a multi-year study of the first-year medical histology component at the University of Michigan found that live lecture attendance was positively correlated with learning success, while lecture video use was negatively correlated. Here, three cohorts of first-year medical students (N = 439 respondents, 86.6% response rate) were surveyed in greater detail regarding lecture attendance and video usage, focusing on study behaviors that may influence histology learning outcomes. Students who reported always attending lectures or viewing lecture videos had higher average histology scores than students who employed an inconsistent strategy (i.e., mixing live attendance and video lectures). Several behaviors were negatively associated with histology performance. Students who engaged in "non-lecture activities" (e.g., social media use), students who reported being interrupted while watching the lecture video, or feeling sleepy/losing focus had lower scores than their counterparts not engaging in these behaviors. This study suggests that interruptions and distractions during medical learning activities-whether live or recorded-can have an important impact on learning outcomes. Anat Sci Educ 00: 000-000. © 2017 American Association of Anatomists. © 2017 American Association of Anatomists.

  16. Trends in National Emergency Medicine Conference Didactic Lectures Over a 6-Year Period.

    Science.gov (United States)

    Gottlieb, Michael; Riddell, Jeff; Njie, Abdoulie

    2017-01-01

    National conference didactic lectures have traditionally featured hour-long lecture-based presentations. However, there is evidence that longer lectures can lead to both decreased attention and retention of information. The authors sought to identify trends in lecture duration, lecture types, and number of speakers at four national emergency medicine (EM) conferences over a 6-year period. The authors performed a retrospective analysis of the length, number of speakers, and format of didactic lectures at four different national EM conferences over 6 years. The authors abstracted data from the national academic assemblies for the four largest not-for-profit EM organizations in the United States: American Academy of Emergency Medicine, American College of Emergency Physicians, Council of Emergency Medicine Residency Directors, and Society for Academic Emergency Medicine. There was a significant yearly decrease in the mean lecture lengths for three of the four conferences. There was an increase in the percentage of rapid fire sessions over the preceding 2 years with a corresponding decrease in the percentage of general educational sessions. There was no significant difference in the mean number of speakers per lecture. An analysis of 4210 didactic lecture sessions from the annual meetings of four national EM organizations over a 6-year period showed significant decreases in mean lecture length. These findings can help to guide EM continuing medical education conference planning and research.

  17. Afterimage watercolors: an exploration of contour-based afterimage filling-in.

    Science.gov (United States)

    Hazenberg, Simon J; van Lier, Rob

    2013-01-01

    We investigated filling-in of colored afterimages and compared them with filling-in of "real" colors in the watercolor illusion. We used shapes comprising two thin adjacent undulating outlines of which the inner or the outer outline was chromatic, while the other was achromatic. The outlines could be presented simultaneously, inducing the original watercolor effect, or in an alternating fashion, inducing colored afterimages of the chromatic outlines. In Experiment 1, using only alternating outlines, these afterimages triggered filling-in, revealing an "afterimage watercolor" effect. Depending on whether the inner or the outer outline was chromatic, filling-in of a complementary or a similarly colored afterimage was perceived. In Experiment 2, simultaneous and alternating presentations were compared. Additionally, gray and black achromatic contours were tested, having an increased luminance contrast with the background for the black contours. Compared to "real" color filling-in, afterimage filling-in was more easily affected by different luminance settings. More in particular, afterimage filling-in was diminished when high-contrast contours were used. In the discussion we use additional demonstrations in which we further explore the "watercolor afterimage." All in all, comparisons between both types of illusions show similarities and differences with regard to color filling-in. Caution, however, is warranted in attributing these effects to different underlying processing differences.

  18. Lectures on Quantum Gravity

    CERN Document Server

    Gomberoff, Andres

    2006-01-01

    The 2002 Pan-American Advanced Studies Institute School on Quantum Gravity was held at the Centro de Estudios Cientificos (CECS),Valdivia, Chile, January 4-14, 2002. The school featured lectures by ten speakers, and was attended by nearly 70 students from over 14 countries. A primary goal was to foster interaction and communication between participants from different cultures, both in the layman’s sense of the term and in terms of approaches to quantum gravity. We hope that the links formed by students and the school will persist throughout their professional lives, continuing to promote interaction and the essential exchange of ideas that drives research forward. This volume contains improved and updated versions of the lectures given at the School. It has been prepared both as a reminder for the participants, and so that these pedagogical introductions can be made available to others who were unable to attend. We expect them to serve students of all ages well.

  19. Lecture 2: Software Security

    CERN Multimedia

    CERN. Geneva

    2013-01-01

    Computer security has been an increasing concern for IT professionals for a number of years, yet despite all the efforts, computer systems and networks remain highly vulnerable to attacks of different kinds. Design flaws and security bugs in the underlying software are among the main reasons for this. This lecture addresses the following question: how to create secure software? The lecture starts with a definition of computer security and an explanation of why it is so difficult to achieve. It then introduces the main security principles (like least-privilege, or defense-in-depth) and discusses security in different phases of the software development cycle. The emphasis is put on the implementation part: most common pitfalls and security bugs are listed, followed by advice on best practice for security development, testing and deployment. Sebastian Lopienski is CERN’s deputy Computer Security Officer. He works on security strategy and policies; offers internal consultancy and audit services; develops and ...

  20. National seminar on nuclear energy in everyday life: lectures

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-06-01

    The document includes 8 lectures presented at the National Seminar on Nuclear Energy in Everyday Life organized by the International Atomic Energy Agency (Vienna) and the Atomic Energy Authority (Egypt) between 28-29 June 1994 in Cairo. A separate abstract was prepared for each lecture.

  1. National seminar on nuclear energy in everyday life: lectures

    International Nuclear Information System (INIS)

    1994-06-01

    The document includes 8 lectures presented at the National Seminar on Nuclear Energy in Everyday Life organized by the International Atomic Energy Agency (Vienna) and the Atomic Energy Authority (Egypt) between 28-29 June 1994 in Cairo. A separate abstract was prepared for each lecture

  2. Values in Higher Education. The Wilson Lecture Series.

    Science.gov (United States)

    Wilson, O. Meredith

    The text of a lecture in the University of Arizona Wilson Lecture Series on values in higher education is presented, with responses by Richard H. Gallagher, Jeanne McRae McCarthy, and Raymond H. Thompson. The theme of the talk is that man is by evolution and by necessity a thinking animal, who now finds himself in a technologically dependent…

  3. The Stanley Melville Memorial Lectures 1937-1945

    International Nuclear Information System (INIS)

    Brian Bentley, H.

    2006-01-01

    The Archibald Reid Memorial Competition theses have been precised in a previous edition of Radiography (Vol 11 Issue 3 Aug 2005). A great deal of information about the development of the profession and techniques was highlighted. In this edition (Vol 12 Issue 1 February 2006) we have looked at the Stanley Melville Memorial Lectures from 1937 to 1945. Unfortunately the First lecture, which took place in 1937, was not published. Eminent speakers, radiologists, radiographers, physicists and industrialists presented papers based on the background of radiography or radiotherapy of that period. There was obviously no point in reprinting the full lecture/paper but in selecting interesting information, quotations and ideas it was hoped to stimulate further reading and to continue the database. The exercise was also undertaken to show the progress made from the beginning to the present day procedures and practice. It will be seen that some of the concepts we hold today were in fact outlined 50 or 60 years ago. The other important thing to note is how the enthusiasm and foresight which people like Stanley Melville exhibited, has brought radiology and radiography, and radiologists and radiographers to the present. Seven of the Melville lectures appear in this paper and those delivered between 1946 and 1950 will form the basis of the next paper in the series

  4. Bifurcations of non-smooth systems

    Science.gov (United States)

    Angulo, Fabiola; Olivar, Gerard; Osorio, Gustavo A.; Escobar, Carlos M.; Ferreira, Jocirei D.; Redondo, Johan M.

    2012-12-01

    Non-smooth systems (namely piecewise-smooth systems) have received much attention in the last decade. Many contributions in this area show that theory and applications (to electronic circuits, mechanical systems, …) are relevant to problems in science and engineering. Specially, new bifurcations have been reported in the literature, and this was the topic of this minisymposium. Thus both bifurcation theory and its applications were included. Several contributions from different fields show that non-smooth bifurcations are a hot topic in research. Thus in this paper the reader can find contributions from electronics, energy markets and population dynamics. Also, a carefully-written specific algebraic software tool is presented.

  5. Evaluation of receptivity of the medical students in a lecture of a large group

    Directory of Open Access Journals (Sweden)

    Vidyarthi SurendraK, Nayak RoopaP, GuptaSandeep K

    2014-04-01

    Full Text Available Background: Lecturing is widely used teaching method in higher education. Instructors of large classes may have only option to deliver lecture to convey informations to large group students.Aims and Objectives: The present study was to evaluate the effectiveness/receptivity of interactive lecturing in a large group of MBBS second year students. Material and Methods: The present study was conducted in the well-equipped lecture theater of Dhanalakshmi Srinivasan Medical College and Hospital (DSMCH, Tamil Nadu. A fully prepared interactive lecture on the specific topic was delivered by using power point presentation for second year MBBS students. Before start to deliver the lecture, instructor distributed multiple choice 10 questionnaires to attempt within 10 minutes. After 30 minutes of delivering lecture, again instructor distributed same 10 sets of multiple choice questionnaires to attempt in 10 minutes. The topic was never disclosed to the students before to deliver the lecture. Statistics: We analyzed the pre-lecture & post-lecture questions of each student by applying the paired t-test formula by using www.openepi.com version 3.01 online/offline software and by using Microsoft Excel Sheet Windows 2010. Results: The 31 male, 80 female including 111 students of average age 18.58 years baseline (pre-lecture receptivity mean % was 30.99 ± 14.64 and post-lecture receptivity mean % was increased upto 53.51± 19.52. The only 12 students out of 111 post-lecture receptivity values was less (mean % 25.8± 10.84 than the baseline (mean % 45± 9.05 receptive value and this reduction of receptivity was more towards negative side. Conclusion: In interactive lecture session with power point presentation students/learners can learn, even in large-class environments, but it should be active-learner centered.

  6. Adult Education between the Wars: The Curious Case of the Selborne Lecture Bureau

    Science.gov (United States)

    Clarke, Richard

    2010-01-01

    "Independent" lecture agencies are a neglected element in the history of education. Between 1918 and 1939, the Selborne Lecture Bureau was a significant national provider of adult education in Britain, both in its own right and as a supplier of lecture(r)s to Women's Institutes and other bodies, and it pioneered the use of films in…

  7. Investigating a model for lecturer training that enables lecturers to plan and carry out meaningful e-learning activities

    DEFF Research Database (Denmark)

    Kjær, Christopher; Hansen, Pernille Stenkil; Christensen, Inger-Marie F.

    2014-01-01

    This paper reports on the effect of a lecturer training model in the shape of an e-learning project based on research on adult and work-based learning. A survey was conducted to explore participants’ learning experiences. Findings show high overall satisfaction, motivation and engagement. Suggest......This paper reports on the effect of a lecturer training model in the shape of an e-learning project based on research on adult and work-based learning. A survey was conducted to explore participants’ learning experiences. Findings show high overall satisfaction, motivation and engagement...

  8. Mandarin-Speaking Children’s Speech Recognition: Developmental Changes in the Influences of Semantic Context and F0 Contours

    Directory of Open Access Journals (Sweden)

    Hong Zhou

    2017-06-01

    Full Text Available The goal of this developmental speech perception study was to assess whether and how age group modulated the influences of high-level semantic context and low-level fundamental frequency (F0 contours on the recognition of Mandarin speech by elementary and middle-school-aged children in quiet and interference backgrounds. The results revealed different patterns for semantic and F0 information. One the one hand, age group modulated significantly the use of F0 contours, indicating that elementary school children relied more on natural F0 contours than middle school children during Mandarin speech recognition. On the other hand, there was no significant modulation effect of age group on semantic context, indicating that children of both age groups used semantic context to assist speech recognition to a similar extent. Furthermore, the significant modulation effect of age group on the interaction between F0 contours and semantic context revealed that younger children could not make better use of semantic context in recognizing speech with flat F0 contours compared with natural F0 contours, while older children could benefit from semantic context even when natural F0 contours were altered, thus confirming the important role of F0 contours in Mandarin speech recognition by elementary school children. The developmental changes in the effects of high-level semantic and low-level F0 information on speech recognition might reflect the differences in auditory and cognitive resources associated with processing of the two types of information in speech perception.

  9. Using Online Lectures to Make Time for Active Learning

    Science.gov (United States)

    Prunuske, Amy J.; Batzli, Janet; Howell, Evelyn; Miller, Sarah

    2012-01-01

    To make time in class for group activities devoted to critical thinking, we integrated a series of short online lectures into the homework assignments of a large, introductory biology course at a research university. The majority of students viewed the online lectures before coming to class and reported that the online lectures helped them to complete the in-class activity and did not increase the amount of time they devoted to the course. In addition, students who viewed the online lecture performed better on clicker questions designed to test lower-order cognitive skills. The in-class activities then gave the students practice analyzing the information in groups and provided the instructor with feedback about the students’ understanding of the material. On the basis of the results of this study, we support creating hybrid course models that allow students to learn the fundamental information outside of class time, thereby creating time during the class period to be dedicated toward the conceptual understanding of the material. PMID:22714412

  10. Lecture programme The reality of science today

    CERN Multimedia

    2007-01-01

    What are the new challenges and realities facing scientific research? What is its place in society today? To answer these questions, the History and Philosophy of Sciences Unit of Geneva University, in collaboration with ASPERA, the European network for astroparticle physics research, has organised a programme of lectures entitled La réalité de la science d’aujourd’hui, enjeux et défis de la diversité. This series of lectures will provide researchers and members of the public with a snapshot of the state of science today from the perspective of laboratories and institutes, and on subjects such as funding policy and technological and legal impact. The first lecture will be given by science historian Dominique Pestre (EHESS & Centre Koyré, Paris), renowned for his contributions to the analysis of science past and present, and notably one of the authors of the work "History of CERN". He will discuss the modern methods of producing scientific knowledge which have been develop...

  11. Recently Published Lectures and Tutorials for ATLAS

    CERN Multimedia

    Herr, J.

    2006-01-01

    As reported in the September 2004 ATLAS eNews, the Web Lecture Archive Project, WLAP, a collaboration between the University of Michigan and CERN, has developed a synchronized system for recording and publishing educational multimedia presentations, using the Web as medium. This year, the University of Michigan team has been asked to record and publish all ATLAS Plenary sessions, as well as a large number of Physics and Computing tutorials. A significant amount of this material has already been published and can be accessed via the links below. The WLAP model is spreading. This summer, the CERN's High School Teachers program has used WLAP's system to record several physics lectures directed toward a broad audience. And a new project called MScribe, which is essentially the WLAP system coupled with an infrared tracking camera, is being used by the University of Michigan to record several University courses this academic year. All lectures can be viewed on any major platform with any common internet browser...

  12. Lecture programme The reality of science today

    CERN Multimedia

    2008-01-01

    John Ellis (CERN): Gauguin’s questions in the context of particle physics.John Ellis (CERN) will speak about: Gauguin’s questions in the context of particle physics In a famous painting, Paul Gauguin asked the universal and eternal questions: Where do we come from? What are we? Where are we going? In this lecture, John Ellis will comment on the prospects of particle physics in an attempt to provide elements of answers to these questions. This is the second in the series of lectures organised by the History and Philosophy of Sciences Unit of Geneva University, in collaboration with ASPERA, the European network for astroparticle physics research, which began with a contribution from Dominique Pestre (EHESS and Centre Koyré, Paris). What are the new challenges and realities facing research? What is its place in today’s society? In this series of lectures covering a range of topics, researchers and members of the general public are invited to think about the state of sc...

  13. A SAS IML Macro for Loglinear Smoothing

    Science.gov (United States)

    Moses, Tim; von Davier, Alina

    2011-01-01

    Polynomial loglinear models for one-, two-, and higher-way contingency tables have important applications to measurement and assessment. They are essentially regarded as a smoothing technique, which is commonly referred to as loglinear smoothing. A SAS IML (SAS Institute, 2002a) macro was created to implement loglinear smoothing according to…

  14. LECTURE CANCELLED - Academic Training Lecture: Implications of LHC Data to New Physics (1/3)

    CERN Multimedia

    2013-01-01

    PLEASE NOTE THAT THIS LECTURE IS CANCELLED by Alex Pomarol Clotet (Universitat Autònoma de Barcelona, Spain). Monday, March 18, 2013 from 11:00 to 12:00 (Europe/Zurich) at CERN ( 4-3-006 - TH Conference Room ) More information here.

  15. Universal Design for Learning in Teaching Large Lecture Classes

    Science.gov (United States)

    Dean, Tereza; Lee-Post, Anita; Hapke, Holly

    2017-01-01

    To augment traditional lecture with instructional tools that provide options for content representation, learner engagement, and learning expression, we followed the Universal Design for Learning (UDL) principles to design and implement a learning environment for teaching and learning in large lecture classes. To this end, we incorporated four…

  16. Analysing Lecturer Practice: The Role of Orientations and Goals

    Science.gov (United States)

    Hannah, John; Stewart, Sepideh; Thomas, Mike

    2011-01-01

    This article continues a fairly recent trend of research examining the teaching practice of university mathematics lecturers. A lecturer's pedagogical practices in a course in linear algebra were discussed via a supportive community of inquiry. We use Schoenfeld's framework describing the relationship of resources, orientations and goals to…

  17. Income and Consumption Smoothing among US States

    DEFF Research Database (Denmark)

    Sørensen, Bent; Yosha, Oved

    within regions but not between regions. This suggests that capital markets transcend regional barriers while credit markets are regional in their nature. Smoothing within the club of rich states is accomplished mainly via capital markets whereas consumption smoothing is dominant within the club of poor...... states. The fraction of a shock to gross state products smoothed by the federal tax-transfer system is the same for various regions and other clubs of states. We calculate the scope for consumption smoothing within various regions and clubs, finding that most gains from risk sharing can be achieved...

  18. Algorithms and Data Structures (lecture 1)

    CERN Multimedia

    CERN. Geneva

    2018-01-01

    Algorithms have existed, in one form or another, for as long as humanity has. During the second half of the 20th century, the field was revolutionised with the introduction of ever faster computers. In these lectures we discuss how algorithms are designed, how to evaluate their speed, and how to identify areas of improvement in existing algorithms. An algorithm consists of more than just a series of instructions; almost as important is the memory structure of the data on which it operates. A part of the lectures will be dedicated to a discussion of the various ways one can store data in memory, and their advantages and disadvantages.

  19. Algorithms and Data Structures (lecture 2)

    CERN Multimedia

    CERN. Geneva

    2018-01-01

    Algorithms have existed, in one form or another, for as long as humanity has. During the second half of the 20th century, the field was revolutionised with the introduction of ever faster computers. In these lectures we discuss how algorithms are designed, how to evaluate their speed, and how to identify areas of improvement in existing algorithms. An algorithm consists of more than just a series of instructions; almost as important is the memory structure of the data on which it operates. A part of the lectures will be dedicated to a discussion of the various ways one can store data in memory, and their advantages and disadvantages.

  20. Reports on memorial lecture meetings on co-operative application finish of the SF cyclotron and its result reports

    International Nuclear Information System (INIS)

    2000-01-01

    The SF cyclotron at the Institute for Nuclear Study (INS) of University of Tokyo began its co-operative application in 1997 to continue its smooth operation during 21 years reaching March, 1997. Together with improvement of INS organization on April, 1997, it was transferred to the Center for Nuclear Study School of Science, University of Tokyo, INS continued a co-operative research for two years thereafter with Tanashi campus of the High Energy Accelerator Research Organization also established on April, 1997. This co-operative research was finished without accident at the end of March, 1999, to close history of co-operative application of cyclotron during 23 years. This report contains 15 memorial lecture and convivial meeting reports at the co-operative application finish of cyclotron and some results of co-operative applications and experiments, during 23 years. (G.K.)