Sample records for volume segmentation analysis

  1. Early Expansion of the Intracranial CSF Volume After Palliative Whole-Brain Radiotherapy: Results of a Longitudinal CT Segmentation Analysis

    SciTech Connect

    Sanghera, Paul [Odette Cancer Centre, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); University Hospital Birmingham, Edgbaston, Birmingham (United Kingdom); Gardner, Sandra L. [Odette Cancer Centre, Toronto, Ontario (Canada); Department of Public Health Sciences, University of Toronto, Toronto, Ontario (Canada); Scora, Daryl [R. S. McLaughlin Durham Regional Cancer Centre, Oshawa, Ontario (Canada); Davey, Phillip, E-mail: phil.davey@sunnybrook.c [Odette Cancer Centre, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada)

    2010-03-15

    Purpose: To assess cerebral atrophy after radiotherapy, we measured intracranial cerebrospinal fluid volume (ICSFV) over time after whole-brain radiotherapy (WBRT) and compared it with published normal-population data. Methods and Materials: We identified 9 patients receiving a single course of WBRT (30 Gy in 10 fractions over 2 weeks) for ipsilateral brain metastases with at least 3 years of computed tomography follow-up. Segmentation analysis was confined to the tumor-free hemi-cranium. The technique was semiautomated by use of thresholds based on scanned image intensity. The ICSFV percentage (ratio of ICSFV to brain volume) was used for modeling purposes. Published normal-population ICSFV percentages as a function of age were used as a control. A repeated-measures model with cross-sectional (between individuals) and longitudinal (within individuals) quadratic components was fitted to the collected data. The influence of clinical factors including the use of subependymal plate shielding was studied. Results: The median imaging follow-up was 6.25 years. There was an immediate increase (p < 0.0001) in ICSFV percentage, which decelerated over time. The clinical factors studied had no significant effect on the model. Conclusions: WBRT immediately accelerates the rate of brain atrophy. This longitudinal study in patients with brain metastases provides a baseline against which the potential benefits of more localized radiotherapeutic techniques such as radiosurgery may be compared.

  2. Segmentation strategies for polymerized volume data sets 

    E-print Network

    Doddapaneni, Venkata Purna

    2006-04-12

    A new technique, called the polymerization algorithm, is described for the hierarchical segmentation of polymerized volume data sets (PVDS) using the Lblock data structure. The Lblock data structure is defined as a 3dimensional isorectangular block...

  3. Effect of body mass index (BMI) on estimation of extracellular volume (ECV) in hemodialysis (HD) patients using segmental and whole body bioimpedance analysis

    Microsoft Academic Search

    Mary Carter; Alice T. Morris; Fansan Zhu; Wojciech Zaluska; Nathan W. Levin

    2005-01-01

    The aim of the study was to investigate whether body mass index (BMI) influences the estimation of extracellular volume (ECV) in hemodialysis (HD) patients when using segmental bioimpedance analysis (SBIA) compared to wrist-to-ankle bioimpedance analysis (WBIA) during HD with ultrafiltration (UF). Twenty five HD patients (M:F 19:6,) were studied, and further subdivided into two groups of patients, one group with

  4. Active volume models for medical image segmentation.

    PubMed

    Shen, Tian; Li, Hongsheng; Huang, Xiaolei

    2011-03-01

    In this paper, we propose a novel predictive model, active volume model (AVM), for object boundary extraction. It is a dynamic "object" model whose manifestation includes a deformable curve or surface representing a shape, a volumetric interior carrying appearance statistics, and an embedded classifier that separates object from background based on current feature information. The model focuses on an accurate representation of the foreground object's attributes, and does not explicitly represent the background. As we will show, however, the model is capable of reasoning about the background statistics thus can detect when is change sufficient to invoke a boundary decision. When applied to object segmentation, the model alternates between two basic operations: 1) deforming according to current region of interest (ROI), which is a binary mask representing the object region predicted by the current model, and 2) predicting ROI according to current appearance statistics of the model. To further improve robustness and accuracy when segmenting multiple objects or an object with multiple parts, we also propose multiple-surface active volume model (MSAVM), which consists of several single-surface AVM models subject to high-level geometric spatial constraints. An AVM's deformation is derived from a linear system based on finite element method (FEM). To keep the model's surface triangulation optimized, surface remeshing is derived from another linear system based on Laplacian mesh optimization (LMO). Thus efficient optimization and fast convergence of the model are achieved by solving two linear systems. Segmentation, validation and comparison results are presented from experiments on a variety of 2-D and 3-D medical images. PMID:21118771

  5. Automated volume analysis of head and neck lesions on CT scans using 3D level set segmentation

    PubMed Central

    Street, Ethan; Hadjiiski, Lubomir; Sahiner, Berkman; Gujar, Sachin; Ibrahim, Mohannad; Mukherji, Suresh K.; Chan, Heang-Ping

    2009-01-01

    The authors have developed a semiautomatic system for segmentation of a diverse set of lesions in head and neck CT scans. The system takes as input an approximate bounding box, and uses a multistage level set to perform the final segmentation. A data set consisting of 69 lesions marked on 33 scans from 23 patients was used to evaluate the performance of the system. The contours from automatic segmentation were compared to both 2D and 3D gold standard contours manually drawn by three experienced radiologists. Three performance metric measures were used for the comparison. In addition, a radiologist provided quality ratings on a 1 to 10 scale for all of the automatic segmentations. For this pilot study, the authors observed that the differences between the automatic and gold standard contours were larger than the interobserver differences. However, the system performed comparably to the radiologists, achieving an average area intersection ratio of 85.4% compared to an average of 91.2% between two radiologists. The average absolute area error was 21.1% compared to 10.8%, and the average 2D distance was 1.38 mm compared to 0.84 mm between the radiologists. In addition, the quality rating data showed that, despite the very lax assumptions made on the lesion characteristics in designing the system, the automatic contours approximated many of the lesions very well. PMID:18072505

  6. Partial volume effect modeling for segmentation and tissue classification of brain magnetic resonance images: A review

    PubMed Central

    Tohka, Jussi

    2014-01-01

    Quantitative analysis of magnetic resonance (MR) brain images are facilitated by the development of automated segmentation algorithms. A single image voxel may contain of several types of tissues due to the finite spatial resolution of the imaging device. This phenomenon, termed partial volume effect (PVE), complicates the segmentation process, and, due to the complexity of human brain anatomy, the PVE is an important factor for accurate brain structure quantification. Partial volume estimation refers to a generalized segmentation task where the amount of each tissue type within each voxel is solved. This review aims to provide a systematic, tutorial-like overview and categorization of methods for partial volume estimation in brain MRI. The review concentrates on the statistically based approaches for partial volume estimation and also explains differences to other, similar image segmentation approaches. PMID:25431640

  7. Medical Volume Segmentation using Bank of Gabor Filters Adebayo Olowoyeye

    E-print Network

    Tuceryan, Mihran

    Terms Algorithm, Design, and Experimentation Keywords Segmentation, Classification, Gabor Filters, K-Means-1-60558-166-8/09/03 ...$5.00. using algorithms that segment based on statistical analysis of image features. Segmentation a variety of clustering algorithms (k-means, fuzzy clustering) to group similar pixels together, resulting

  8. Tumor volume measurement for nasopharyngeal carcinoma using knowledge-based fuzzy clustering MRI segmentation

    NASA Astrophysics Data System (ADS)

    Zhou, Jiayin; Lim, Tuan-Kay; Chong, Vincent

    2002-05-01

    A knowledge-based fuzzy clustering (KBFC) MRI segmentation algorithm was proposed to obtain accurate tumor segmentation for tumor volume measurement of nasopharyngeal carcinoma (NPC). An initial segmentation was performed on T1 and contrast enhanced T1 MR images using a semi-supervised fuzzy c-means (SFCM) algorithm. Then, three types of anatomic and space knowledge--symmetry, connectivity and cluster center were used for image analysis which contributed the final tumor segmentation. After the segmentation, tumor volume was obtained by multi-planimetry method. Visual and quantitative validations were performed on phantom model and six data volumes of NPC patients, compared with ground truth (GT) and the results acquired using seeds growing (SG) for tumor segmentation. In visual format, KBFC showed better tumor segmentation image than SG. In quantitative segmentation quality estimation, on phantom model, the matching percent (MP) / correspondence ratio (CR) was 94.1-96.4% / 0.888-0.925 for KBFC and 94.1-96.0% / 0.884-0.918 for SG while on patient data volumes, it was 92.1+/- 2.6% / 0.884+/- 0.014 for KBFC and 87.4+/- 4.3% / 0.843+/- 0.041 for SG. In tumor volume measurement, on phantom model, measurement error was 4.2-5.0% for KBFC and 4.8-6.1% for SG while on patient data volumes, it was 6.6+/- 3.5% for KBFC and 8.8+/- 5.4% for SG. Based on these results, KBFC could provide high quality of MRI tumor segmentation for tumor volume measurement of NPC.

  9. 3D visualization for medical volume segmentation validation

    NASA Astrophysics Data System (ADS)

    Eldeib, Ayman M.

    2002-05-01

    This paper presents a 3-D visualization tool that manipulates and/or enhances by user input the segmented targets and other organs. A 3-D visualization tool is developed to create a precise and realistic 3-D model from CT/MR data set for manipulation in 3-D and permitting physician or planner to look through, around, and inside the various structures. The 3-D visualization tool is designed to assist and to evaluate the segmentation process. It can control the transparency of each 3-D object. It displays in one view a 2-D slice (axial, coronal, and/or sagittal)within a 3-D model of the segmented tumor or structures. This helps the radiotherapist or the operator to evaluate the adequacy of the generated target compared to the original 2-D slices. The graphical interface enables the operator to easily select a specific 2-D slice of the 3-D volume data set. The operator is enabled to manually override and adjust the automated segmentation results. After correction, the operator can see the 3-D model again and go back and forth till satisfactory segmentation is obtained. The novelty of this research work is in using state-of-the-art of image processing and 3-D visualization techniques to facilitate a process of a medical volume segmentation validation and assure the accuracy of the volume measurement of the structure of interest.

  10. Reliability of tissue volumes and their spatial distribution for segmented magnetic resonance images.

    PubMed

    Cardenas, V A; Ezekiel, F; Di Sclafani, V; Gomberg, B; Fein, G

    2001-05-30

    Before using MRI tissue segmentation in clinical studies as a dependent variable or as a means to correct functional data for differential tissue contribution, we must first establish the volume reliability and spatial distribution reproducibility of the segmentation method. Although several reports of volume reliability can be found in the literature, there are no articles assessing the reproducibility of the spatial distribution of tissue. In this report, we examine the validity, volume reliability, and spatial distribution reproducibility for our K-means cluster segmentation. Validation was examined by classifying gray matter, white matter, and CSF on images constructed using an MRI simulator and digital brain phantom, with percentage volume differences of less than 5% and spatial distribution overlaps greater than 0.94 (1.0 is perfect). We also segmented repeat scan MRIs from 10 healthy subjects, with intraclass correlation coefficients greater than 0.92 for cortical gray matter, white matter, sulcal CSF, and ventricular CSF. The original scans were also coregistered to the repeat scan of the same subject, and the spatial overlap for each tissue was then computed. Our overlaps ranged from 0.75 to 0.86 for these tissues. Our results support the use of K-means cluster segmentation, and the use of segmented structural MRIs to guide the analysis of functional and other images. PMID:11382541

  11. Learning Context Cues for Synapse Segmentation in EM Volumes

    E-print Network

    Dalang, Robert C.

    Learning Context Cues for Synapse Segmentation in EM Volumes Carlos Becker , Karim Ali, Graham spatial context into account and train a classifier that can effectively utilize cues such as the presence entirely in 3D. However, it does not exploit the contextual clues that allow human experts to distinguish

  12. Scan-rescan reliability of subcortical brain volumes derived from automated segmentation.

    PubMed

    Morey, Rajendra A; Selgrade, Elizabeth S; Wagner, Henry Ryan; Huettel, Scott A; Wang, Lihong; McCarthy, Gregory

    2010-11-01

    Large-scale longitudinal studies of regional brain volume require reliable quantification using automated segmentation and labeling. However, repeated MR scanning of the same subject, even if using the same scanner and acquisition parameters, does not result in identical images due to small changes in image orientation, changes in prescan parameters, and magnetic field instability. These differences may lead to appreciable changes in estimates of volume for different structures. This study examined scan-rescan reliability of automated segmentation algorithms for measuring several subcortical regions, using both within-day and across-day comparison sessions in a group of 23 normal participants. We found that the reliability of volume measures including percent volume difference, percent volume overlap (Dice's coefficient), and intraclass correlation coefficient (ICC), varied substantially across brain regions. Low reliability was observed in some structures such as the amygdala (ICC = 0.6), with higher reliability (ICC = 0.9) for other structures such as the thalamus and caudate. Patterns of reliability across regions were similar for automated segmentation with FSL/FIRST and FreeSurfer (longitudinal stream). Reliability was associated with the volume of the structure, the ratio of volume to surface area for the structure, the magnitude of the interscan interval, and the method of segmentation. Sample size estimates for detecting changes in brain volume for a range of likely effect sizes also differed by region. Thus, longitudinal research requires a careful analysis of sample size and choice of segmentation method combined with a consideration of the brain structure(s) of interest and the magnitude of the anticipated effects. PMID:20162602

  13. Segmental approach to lung volume reduction therapy for emphysema patients.

    PubMed

    Bandyopadhyay, Sourish; Henne, Erik; Gupta, Avina; Barry, Robert; Snell, Greg; Strange, Charlie; Herth, Felix J F

    2015-01-01

    Emphysema is often distributed heterogeneously throughout the lungs, even at the segmental level. It is important for interventional lung volume reduction therapies to target and treat the most diseased regions of the lung while preserving the less diseased functional regions. Identification and determination of the severity of emphysema can be done using the various quantification measures reviewed in this article. However, all of these measures are similar in what they quantify and are equally good indicators of emphysema. The tissue/air ratio was chosen for our purposes. Software capable of quantifying emphysema severity at the segmental level exists, and can be utilized to identify the most diseased segments while following anatomical boundaries. The segmental heterogeneity index is a new measure being introduced to help quantify differences in emphysema severity at the segmental level. The goal of segmental targeting is to improve efficacy and safety outcomes of vapor ablation patients. The Sequential Staged Treatment of Emphysema with Upper Lobe Predominance (STEP-UP, NCT01719263) trial is currently enrolling patients with upper lobe heterogeneous emphysema using these techniques. PMID:25500669

  14. Industry Analysis and Customer Segmentation Company Description

    E-print Network

    Dahl, David B.

    Industry Analysis and Customer Segmentation Company Description: Our company specializes in baseball equipment, but also manufactures softball, basketball, training equipment and American footballs benefits and services industry, our businesses offer exceptional service, broad capabilities and enduring

  15. Partial volume segmentation of brain magnetic resonance images based on maximum a posteriori probability

    E-print Network

    resonance imaging, fuzzy C-mean algorithm, Markov random field, PV segmentation, intensity inhomogeneityPartial volume segmentation of brain magnetic resonance images based on maximum a posteriori, and image-intensity inhomogeneity render a challenging task for segmentation of brain magnetic resonance MR

  16. Clinical value of prostate segmentation and volume determination on MRI in benign prostatic hyperplasia.

    PubMed

    Garvey, Brian; Türkbey, Bar??; Truong, Hong; Bernardo, Marcelino; Periaswamy, Senthil; Choyke, Peter L

    2014-01-01

    Benign prostatic hyperplasia (BPH) is a nonmalignant pathological enlargement of the prostate, which occurs primarily in the transitional zone. BPH is highly prevalent and is a major cause of lower urinary tract symptoms in aging males, although there is no direct relationship between prostate volume and symptom severity. The progression of BPH can be quantified by measuring the volumes of the whole prostate and its zones, based on image segmentation on magnetic resonance imaging. Prostate volume determination via segmentation is a useful measure for patients undergoing therapy for BPH. However, prostate segmentation is not widely used due to the excessive time required for even experts to manually map the margins of the prostate. Here, we review and compare new methods of prostate volume segmentation using both manual and automated methods, including the ellipsoid formula, manual planimetry, and semiautomated and fully automated segmentation approaches. We highlight the utility of prostate segmentation in the clinical context of assessing BPH. PMID:24675166

  17. Clinical value of prostate segmentation and volume determination on MRI in benign prostatic hyperplasia

    PubMed Central

    Garvey, Brian; Türkbey, Bar??; Truong, Hong; Bernardo, Marcelino; Periaswamy, Senthil; Choyke, Peter L.

    2014-01-01

    Benign prostatic hyperplasia (BPH) is a nonmalignant pathological enlargement of the prostate, which occurs primarily in the transitional zone. BPH is highly prevalent and is a major cause of lower urinary tract symptoms in aging males, although there is no direct relationship between prostate volume and symptom severity. The progression of BPH can be quantified by measuring the volumes of the whole prostate and its zones, based on image segmentation on magnetic resonance imaging. Prostate volume determination via segmentation is a useful measure for patients undergoing therapy for BPH. However, prostate segmentation is not widely used due to the excessive time required for even experts to manually map the margins of the prostate. Here, we review and compare new methods of prostate volume segmentation using both manual and automated methods, including the ellipsoid formula, manual planimetry, and semiautomated and fully automated segmentation approaches. We highlight the utility of prostate segmentation in the clinical context of assessing BPH. PMID:24675166

  18. Spinal Cord Segmentation for Volume Estimation in Healthy and Multiple Sclerosis Subjects using Crawlers and Minimal Paths

    E-print Network

    Hamarneh, Ghassan

    Spinal Cord Segmentation for Volume Estimation in Healthy and Multiple Sclerosis Subjects using Columbia Vancouver, Canada roger.tam@ubc.ca Abstract--Spinal cord analysis is an important problem of both healthy and pathological spinal cords from clinical MR data. This is the first study to validate

  19. Segmented ray casting for data parallel volume rendering

    Microsoft Academic Search

    William M. Hsu

    1993-01-01

    Interactive volume rendering is important for the timely analysis of three-dimensional data, but workstations take seconds to minutes to render data sets of a few megabytes. We have developed a parallel ray-casting technique. called Sepnenred Ray Cnsting, which can render a 128x128~128 data set at 2-3 frames per second on a 4K processor DECmpp 12OOO\\/Sx Model 100. Pixel values in

  20. Fuzzy hidden Markov chains segmentation for volume determination and quantitation in PET

    PubMed Central

    Hatt, Mathieu; Lamare, Frédéric; Boussion, Nicolas; Roux, Christian; Turzo, Alexandre; Cheze-Lerest, Catherine; Jarritt, Peter; Carson, Kathryn; Salzenstein, Fabien; Collet, Christophe; Visvikis, Dimitris

    2007-01-01

    Accurate volume of interest (VOI) estimation in PET is crucial in different oncology applications such as response to therapy evaluation and radiotherapy treatment planning. The objective of our study was to evaluate the performance of the proposed algorithm for automatic lesion volume delineation; namely the Fuzzy Hidden Markov Chains (FHMC), with that of current state of the art in clinical practice threshold based techniques. As the classical Hidden Markov Chain (HMC) algorithm, FHMC takes into account noise, voxel’s intensity and spatial correlation, in order to classify a voxel as background or functional VOI. However the novelty of the fuzzy model consists of the inclusion of an estimation of imprecision, which should subsequently lead to a better modelling of the “fuzzy” nature of the object on interest boundaries in emission tomography data. The performance of the algorithms has been assessed on both simulated and acquired datasets of the IEC phantom, covering a large range of spherical lesion sizes (from 10 to 37mm), contrast ratios (4:1 and 8:1) and image noise levels. Both lesion activity recovery and VOI determination tasks were assessed in reconstructed images using two different voxel sizes (8mm3 and 64mm3). In order to account for both the functional volume location and its size, the concept of % classification errors was introduced in the evaluation of volume segmentation using the simulated datasets. Results reveal that FHMC performs substantially better than the threshold based methodology for functional volume determination or activity concentration recovery considering a contrast ratio of 4:1 and lesion sizes of <28mm. Furthermore differences between classification and volume estimation errors evaluated were smaller for the segmented volumes provided by the FHMC algorithm. Finally, the performance of the automatic algorithms was less susceptible to image noise levels in comparison to the threshold based techniques. The analysis of both simulated and acquired datasets led to similar results and conclusions as far as the performance of segmentation algorithms under evaluation is concerned. PMID:17664555

  1. Recent advances in segmented gamma scanner analysis

    SciTech Connect

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

    1987-01-01

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

  2. A Theoretical Solution to MAP-EM Partial Volume Segmentation of Medical Images

    E-print Network

    A Theoretical Solution to MAP-EM Partial Volume Segmentation of Medical Images Su Wang, Hongyu Lu, Zhengrong Liang Department of Radiology, State University of New York, Stony Brook, NY 11794 Received 4

  3. Segmentation methods for character recognition: from segmentation to document structure analysis

    Microsoft Academic Search

    HIROMICHI FUJISAWA; YASUAKI NAKANO; KIYOMICHI KURINO

    1992-01-01

    A pattern-oriented segmentation method for optical character recognition that leads to document structure analysis is presented. As a first example, segmentation of handwritten numerals that touch are treated. Connected pattern components are extracted, and spatial interrelations between components are measured and grouped into meaningful character patterns. Stroke shapes are analyzed and a method of finding the touching positions that separates

  4. Automated lung tumor segmentation for whole body PET volume based on novel downhill region growing

    NASA Astrophysics Data System (ADS)

    Ballangan, Cherry; Wang, Xiuying; Eberl, Stefan; Fulham, Michael; Feng, Dagan

    2010-03-01

    We propose an automated lung tumor segmentation method for whole body PET images based on a novel downhill region growing (DRG) technique, which regards homogeneous tumor hotspots as 3D monotonically decreasing functions. The method has three major steps: thoracic slice extraction with K-means clustering of the slice features; hotspot segmentation with DRG; and decision tree analysis based hotspot classification. To overcome the common problem of leakage into adjacent hotspots in automated lung tumor segmentation, DRG employs the tumors' SUV monotonicity features. DRG also uses gradient magnitude of tumors' SUV to improve tumor boundary definition. We used 14 PET volumes from patients with primary NSCLC for validation. The thoracic region extraction step achieved good and consistent results for all patients despite marked differences in size and shape of the lungs and the presence of large tumors. The DRG technique was able to avoid the problem of leakage into adjacent hotspots and produced a volumetric overlap fraction of 0.61 +/- 0.13 which outperformed four other methods where the overlap fraction varied from 0.40 +/- 0.24 to 0.59 +/- 0.14. Of the 18 tumors in 14 NSCLC studies, 15 lesions were classified correctly, 2 were false negative and 15 were false positive.

  5. 3D robust Chan-Vese model for industrial computed tomography volume data segmentation

    NASA Astrophysics Data System (ADS)

    Liu, Linghui; Zeng, Li; Luan, Xiao

    2013-11-01

    Industrial computed tomography (CT) has been widely applied in many areas of non-destructive testing (NDT) and non-destructive evaluation (NDE). In practice, CT volume data to be dealt with may be corrupted by noise. This paper addresses the segmentation of noisy industrial CT volume data. Motivated by the research on the Chan-Vese (CV) model, we present a region-based active contour model that draws upon intensity information in local regions with a controllable scale. In the presence of noise, a local energy is firstly defined according to the intensity difference within a local neighborhood. Then a global energy is defined to integrate local energy with respect to all image points. In a level set formulation, this energy is represented by a variational level set function, where a surface evolution equation is derived for energy minimization. Comparative analysis with the CV model indicates the comparable performance of the 3D robust Chan-Vese (RCV) model. The quantitative evaluation also shows the segmentation accuracy of 3D RCV. In addition, the efficiency of our approach is validated under several types of noise, such as Poisson noise, Gaussian noise, salt-and-pepper noise and speckle noise.

  6. A Fuzzy Locally Adaptive Bayesian Segmentation Approach for Volume Determination in PET

    Microsoft Academic Search

    Mathieu Hatt; Catherine Cheze-Le Rest; Alexandre Turzo; Christian Roux; Dimitris Visvikis

    2009-01-01

    Accurate volume estimation in positron emission tomography (PET) is crucial for different oncology applications. The objective of our study was to develop a new fuzzy locally adaptive Bayesian (FLAB) segmentation for automatic lesion volume delineation. FLAB was compared with a threshold approach as well as the previously proposed fuzzy hidden Markov chains (FHMC) and the fuzzy C-Means (FCM) algorithms. The

  7. Watershed-based segmentation of 3D MR data for volume quantization

    Microsoft Academic Search

    J. Sijbers; P. Scheunders; M. Verhoye; A. Van der Linden; D. van Dyck; E. Raman

    1997-01-01

    The aim of this work is the development of a semiautomatic segmentation technique for efficient and accurate volume quantization of Magnetic Resonance (MR) data. The proposed technique uses a 3D variant of Vincent and Soilles immersion-based watershed algorithm that is applied to the gradient magnitude of the MR data and that produces small volume primitives. The known drawback of the

  8. Spinal Crawlers: Deformable Organisms for Spinal Cord Segmentation and Analysis

    E-print Network

    Hamarneh, Ghassan

    Spinal Crawlers: Deformable Organisms for Spinal Cord Segmentation and Analysis Chris Mc, Canada {cmcintos, hamarneh}@cs.sfu.ca Abstract. Spinal cord analysis is an important problem relating to the study of various neurological diseases. We present a novel approach to spinal cord segmentation

  9. Glomeruli Segmentation Based on Neural Network with Fault Tolerance Analysis

    Microsoft Academic Search

    Jun Zhang; Jinglu Hu

    2008-01-01

    Image segmentation, which is the first essential and fundamental issue in the image analysis and pattern recognition, is a classical difficult problem in image processing. In the computer-aided diagnosis system of the renal biopsy images in microscope, the correct segmentation of glomerulus is an important step for automatic analysis. Complex characteristics of renal biopsy images lead to the difficulty in

  10. Automatic segmentation of the fetal cerebellum on ultrasound volumes, using a 3D statistical shape model.

    PubMed

    Gutiérrez-Becker, Benjamín; Arámbula Cosío, Fernando; Guzmán Huerta, Mario E; Benavides-Serralde, Jesús Andrés; Camargo-Marín, Lisbeth; Medina Bañuelos, Verónica

    2013-09-01

    Previous work has shown that the segmentation of anatomical structures on 3D ultrasound data sets provides an important tool for the assessment of the fetal health. In this work, we present an algorithm based on a 3D statistical shape model to segment the fetal cerebellum on 3D ultrasound volumes. This model is adjusted using an ad hoc objective function which is in turn optimized using the Nelder-Mead simplex algorithm. Our algorithm was tested on ultrasound volumes of the fetal brain taken from 20 pregnant women, between 18 and 24 gestational weeks. An intraclass correlation coefficient of 0.8528 and a mean Dice coefficient of 0.8 between cerebellar volumes measured using manual techniques and the volumes calculated using our algorithm were obtained. As far as we know, this is the first effort to automatically segment fetal intracranial structures on 3D ultrasound data. PMID:23686392

  11. Design and Analysis of an Efficient Evolutionary Image Segmentation Algorithm

    Microsoft Academic Search

    Shinn-ying Ho; Kual-zheng Lee

    2003-01-01

    Evolutionary image segmentation algorithms have a number of advantages such as continuous contour, non-oversegmentation, and non-thresholds. However, most of the evolutionary image segmentation algorithms suffer from long computation time because the number of encoding parameters is large. In this paper, design and analysis of an efficient evolutionary image segmentation algorithm EISA are proposed. EISA uses a K-means algorithm to split

  12. Market segmentation with choice-based conjoint analysis

    Microsoft Academic Search

    Wayne S. Desarbo; Venkatram Ramaswamy; Steven H. Cohen

    1995-01-01

    Choice-based conjoint analysis has increased in popularity in recent years among marketing practitioners. The typical practice is to estimate choice-based conjoint models at the aggregate level, given insufficient data for individual-level estimation of part-worths. We discuss a method for market segmentation with choice-based conjoint models. This method determines the number of market segments, the size of each market segment, and

  13. A HIERARCHICAL SEGMENTATION ALGORITHM FOR FACE ANALYSIS. APPLICATION TO LIPREADING

    E-print Network

    Paris-Sud XI, Université de

    color segmentation algorithm (fuzzy c-means). A speaker's lip shape with inner and outer bordersA HIERARCHICAL SEGMENTATION ALGORITHM FOR FACE ANALYSIS. APPLICATION TO LIPREADING M. Li´evin and F. Luthon Signal and Image Laboratory, Grenoble National Polytechnic Institute, LIS, INPG, 46 av. F

  14. Comparison of EM-based and level set partial volume segmentations of MR brain images

    NASA Astrophysics Data System (ADS)

    Tagare, Hemant D.; Chen, Yunmei; Fulbright, Robert K.

    2008-03-01

    EM and level set algorithms are competing methods for segmenting MRI brain images. This paper presents a fair comparison of the two techniques using the Montreal Neurological Institute's software phantom. There are many flavors of level set algorithms for segmentation into multiple regions (multi-phase algorithms, multi-layer algorithms). The specific algorithm evaluated by us is a variant of the multi-layer level set algorithm. It uses a single level set function for segmenting the image into multiple classes and can be run to completion without restarting. The EM-based algorithm is standard. Both algorithms have the capacity to model a variable number of partial volume classes as well as image inhomogeneity (bias field). Our evaluation consists of systematically changing the number of partial volume classes, additive image noise, and regularization parameters. The results suggest that the performances of both algorithms are comparable across noise, number of partial volume classes, and regularization. The segmentation errors of both algorithms are around 5 - 10% for cerebrospinal fluid, gray and white matter. The level set algorithm appears to have a slight advantage for gray matter segmentation. This may be beneficial in studying certain brain diseases (Multiple Sclerosis or Alzheimer's disease) where small changes in gray matter volume are significant.

  15. Multi-region unstructured volume segmentation using tetrahedron filling

    SciTech Connect

    Willliams, Sean Jamerson [Los Alamos National Laboratory; Dillard, Scott E [Los Alamos National Laboratory; Thoma, Dan J [MDI, INSTITUTES; Hlawitschka, Mario [UC DAVIS; Hamann, Bernd [UC DAVIS

    2010-01-01

    Segmentation is one of the most common operations in image processing, and while there are several solutions already present in the literature, they each have their own benefits and drawbacks that make them well-suited for some types of data and not for others. We focus on the problem of breaking an image into multiple regions in a single segmentation pass, while supporting both voxel and scattered point data. To solve this problem, we begin with a set of potential boundary points and use a Delaunay triangulation to complete the boundaries. We use heuristic- and interaction-driven Voronoi clustering to find reasonable groupings of tetrahedra. Apart from the computation of the Delaunay triangulation, our algorithm has linear time complexity with respect to the number of tetrahedra.

  16. Pulmonary airways tree segmentation from CT examinations using adaptive volume of interest

    NASA Astrophysics Data System (ADS)

    Park, Sang Cheol; Kim, Won Pil; Zheng, Bin; Leader, Joseph K.; Pu, Jiantao; Tan, Jun; Gur, David

    2009-02-01

    Airways tree segmentation is an important step in quantitatively assessing the severity of and changes in several lung diseases such as chronic obstructive pulmonary disease (COPD), asthma, and cystic fibrosis. It can also be used in guiding bronchoscopy. The purpose of this study is to develop an automated scheme for segmenting the airways tree structure depicted on chest CT examinations. After lung volume segmentation, the scheme defines the first cylinder-like volume of interest (VOI) using a series of images depicting the trachea. The scheme then iteratively defines and adds subsequent VOIs using a region growing algorithm combined with adaptively determined thresholds in order to trace possible sections of airways located inside the combined VOI in question. The airway tree segmentation process is automatically terminated after the scheme assesses all defined VOIs in the iteratively assembled VOI list. In this preliminary study, ten CT examinations with 1.25mm section thickness and two different CT image reconstruction kernels ("bone" and "standard") were selected and used to test the proposed airways tree segmentation scheme. The experiment results showed that (1) adopting this approach affectively prevented the scheme from infiltrating into the parenchyma, (2) the proposed method reasonably accurately segmented the airways trees with lower false positive identification rate as compared with other previously reported schemes that are based on 2-D image segmentation and data analyses, and (3) the proposed adaptive, iterative threshold selection method for the region growing step in each identified VOI enables the scheme to segment the airways trees reliably to the 4th generation in this limited dataset with successful segmentation up to the 5th generation in a fraction of the airways tree branches.

  17. LANDSAT-D program. Volume 2: Ground segment

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Raw digital data, as received from the LANDSAT spacecraft, cannot generate images that meet specifications. Radiometric corrections must be made to compensate for aging and for differences in sensitivity among the instrument sensors. Geometric corrections must be made to compensate for off-nadir look angle, and to calculate spacecraft drift from its prescribed path. Corrections must also be made for look-angle jitter caused by vibrations induced by spacecraft equipment. The major components of the LANDSAT ground segment and their functions are discussed.

  18. Statistical Structure Analysis in MRI Brain Tumor Segmentation

    Microsoft Academic Search

    Xiao Xuan; Qingmin Liao

    2007-01-01

    Automated MRI (Magnetic Resonance Imaging) brain tumor segmentation is a difficult task due to the variance and complexity of tumors. In this paper, a statistical structure analysis based tumor segmentation scheme is presented, which focuses on the structural analysis on both tumorous and normal tissues. Firstly, 3 kinds of features including intensity-based, symmetry-based and texture-based are extracted from structural elements.

  19. FUZZY VERSUS HARD HIDDEN MARKOV CHAINS SEGMENTATION FOR VOLUME DETERMINATION AND QUANTITATION IN NOISY PET IMAGES

    E-print Network

    FUZZY VERSUS HARD HIDDEN MARKOV CHAINS SEGMENTATION FOR VOLUME DETERMINATION AND QUANTITATION such as edge detection [3] or fuzzy C-Means [4]. The performance of these algorithms greatly depends IN NOISY PET IMAGES M. Hatt1 , N. Boussion1 , Member IEEE, F. Lamare1 , Student Member IEEE, C. Collet2 , F

  20. Microarray Analysis of Focal Segmental Glomerulosclerosis

    Microsoft Academic Search

    Kristopher Schwab; David P. Witte; Bruce J. Aronow; Prasad Devarajan; S. Steven Potter; Larry T. Patterson

    2004-01-01

    Background: Focal segmental glomerulosclerosis (FSGS) is a leading cause of chronic renal failure in children. Recent studies have begun to define the molecular pathogenesis of this heterogeneous condition. Here we use oligonucleotide microarrays to obtain a global gene expression profile of kidney biopsy specimens from patients with FSGS in order to better understand the pathogenesis of this disease. Methods: We

  1. Shape segmentation using local slippage analysis

    Microsoft Academic Search

    Natasha Gelfand; Leonidas J. Guibas

    2004-01-01

    We propose a method for segmentation of 3D scanned shapes into simple geometric parts. Given an input point cloud, our method computes a set of components which possess one or more slippable motions: rigid motions which, when applied to a shape, slide the transformed version against the stationary version without forming any gaps. Slippable shapes include rotationally and translationally symmetrical

  2. Scene analysis by integrating primitive segmentation and associative memory.

    PubMed

    Wang, Deliang; Liu, Xiuwen

    2002-01-01

    Scene analysis is a major aspect of perception and continues to challenge machine perception. This paper addresses the scene-analysis problem by integrating a primitive segmentation stage with a model of associative memory. The model is a multistage system that consists of an initial primitive segmentation stage, a multimodule associative memory, and a short-term memory (STM) layer. Primitive segmentation is performed by a locally excitatory globally inhibitory oscillator network (LEGION), which segments the input scene into multiple parts that correspond to groups of synchronous oscillations. Each segment triggers memory recall and multiple recalled patterns then interact with one another in the STM layer. The STM layer projects to the LEGION network, giving rise to memory-based grouping and segmentation. The system achieves scene analysis entirely in phase space, which provides a unifying mechanism for both bottom-up analysis and top-down analysis. The model is evaluated with a systematic set of three-dimensional (3-D) line drawing objects, which are arranged in an arbitrary fashion to compose input scenes that allow object occlusion. Memory-based organization is responsible for a significant improvement in performance. A number of issues are discussed, including input-anchored alignment, top-down organization, and the role of STM in producing context sensitivity of memory recall. PMID:18238125

  3. Generalized method for partial volume estimation and tissue segmentation in cerebral magnetic resonance images

    PubMed Central

    Khademi, April; Venetsanopoulos, Anastasios; Moody, Alan R.

    2014-01-01

    Abstract. An artifact found in magnetic resonance images (MRI) called partial volume averaging (PVA) has received much attention since accurate segmentation of cerebral anatomy and pathology is impeded by this artifact. Traditional neurological segmentation techniques rely on Gaussian mixture models to handle noise and PVA, or high-dimensional feature sets that exploit redundancy in multispectral datasets. Unfortunately, model-based techniques may not be optimal for images with non-Gaussian noise distributions and/or pathology, and multispectral techniques model probabilities instead of the partial volume (PV) fraction. For robust segmentation, a PV fraction estimation approach is developed for cerebral MRI that does not depend on predetermined intensity distribution models or multispectral scans. Instead, the PV fraction is estimated directly from each image using an adaptively defined global edge map constructed by exploiting a relationship between edge content and PVA. The final PVA map is used to segment anatomy and pathology with subvoxel accuracy. Validation on simulated and real, pathology-free T1 MRI (Gaussian noise), as well as pathological fluid attenuation inversion recovery MRI (non-Gaussian noise), demonstrate that the PV fraction is accurately estimated and the resultant segmentation is robust. Comparison to model-based methods further highlight the benefits of the current approach.

  4. Pipe segment failure dependency analysis and system failure probability estimation

    Microsoft Academic Search

    Liyang Xie

    1998-01-01

    The present paper is mainly concerned with pipe-system failure probability estimation. For this purpose, a multiple component dependent failure (MCDF) model is introduced to deal with dependency among pipe-segment failures. The MCDF model is directly derived from load–strength interference analysis with the underlying notion that stochastic environment load brings about failure dependency. The influence of pipe-segment failure dependency on pipe-system

  5. Automatic segmentation of tumor-laden lung volumes from the LIDC database

    NASA Astrophysics Data System (ADS)

    O'Dell, Walter G.

    2012-03-01

    The segmentation of the lung parenchyma is often a critical pre-processing step prior to application of computer-aided detection of lung nodules. Segmentation of the lung volume can dramatically decrease computation time and reduce the number of false positive detections by excluding from consideration extra-pulmonary tissue. However, while many algorithms are capable of adequately segmenting the healthy lung, none have been demonstrated to work reliably well on tumor-laden lungs. Of particular challenge is to preserve tumorous masses attached to the chest wall, mediastinum or major vessels. In this role, lung volume segmentation comprises an important computational step that can adversely affect the performance of the overall CAD algorithm. An automated lung volume segmentation algorithm has been developed with the goals to maximally exclude extra-pulmonary tissue while retaining all true nodules. The algorithm comprises a series of tasks including intensity thresholding, 2-D and 3-D morphological operations, 2-D and 3-D floodfilling, and snake-based clipping of nodules attached to the chest wall. It features the ability to (1) exclude trachea and bowels, (2) snip large attached nodules using snakes, (3) snip small attached nodules using dilation, (4) preserve large masses fully internal to lung volume, (5) account for basal aspects of the lung where in a 2-D slice the lower sections appear to be disconnected from main lung, and (6) achieve separation of the right and left hemi-lungs. The algorithm was developed and trained to on the first 100 datasets of the LIDC image database.

  6. Segmentation and learning in the quantitative analysis of microscopy images

    NASA Astrophysics Data System (ADS)

    Ruggiero, Christy; Ross, Amy; Porter, Reid

    2015-02-01

    In material science and bio-medical domains the quantity and quality of microscopy images is rapidly increasing and there is a great need to automatically detect, delineate and quantify particles, grains, cells, neurons and other functional "objects" within these images. These are challenging problems for image processing because of the variability in object appearance that inevitably arises in real world image acquisition and analysis. One of the most promising (and practical) ways to address these challenges is interactive image segmentation. These algorithms are designed to incorporate input from a human operator to tailor the segmentation method to the image at hand. Interactive image segmentation is now a key tool in a wide range of applications in microscopy and elsewhere. Historically, interactive image segmentation algorithms have tailored segmentation on an image-by-image basis, and information derived from operator input is not transferred between images. But recently there has been increasing interest to use machine learning in segmentation to provide interactive tools that accumulate and learn from the operator input over longer periods of time. These new learning algorithms reduce the need for operator input over time, and can potentially provide a more dynamic balance between customization and automation for different applications. This paper reviews the state of the art in this area, provides a unified view of these algorithms, and compares the segmentation performance of various design choices.

  7. A segmentation method of merged numerals by wavelet analysis and GVF model

    Microsoft Academic Search

    Jian-Jia Pan; Yuan-Yan Tang

    2008-01-01

    Aiming for some limit of the recognition-free approach to the segment merged numerals, a new segmentation method is proposed based on GVF mode in this paper. Firstly, this paper presents a new segment model based on wavelet multi-scale analysis and GVF model, and then we apply this energy model to segment the merged numerals. This method got the candidate segment

  8. Leaf image segmentation method based on multifractal detrended fluctuation analysis

    NASA Astrophysics Data System (ADS)

    Wang, Fang; Li, Jin-Wei; Shi, Wen; Liao, Gui-Ping

    2013-12-01

    To identify singular regions of crop leaf affected by diseases, based on multifractal detrended fluctuation analysis (MF-DFA), an image segmentation method is proposed. In the proposed method, first, we defend a new texture descriptor: local generalized Hurst exponent, recorded as LHq based on MF-DFA. And then, box-counting dimension f(LHq) is calculated for sub-images constituted by the LHq of some pixels, which come from a specific region. Consequently, series of f(LHq) of the different regions can be obtained. Finally, the singular regions are segmented according to the corresponding f(LHq). Six kinds of corn diseases leaf's images are tested in our experiments. Both the proposed method and other two segmentation methods—multifractal spectrum based and fuzzy C-means clustering have been compared in the experiments. The comparison results demonstrate that the proposed method can recognize the lesion regions more effectively and provide more robust segmentations.

  9. Topology Adaptive Deformable Surfaces for Medical Image Volume Segmentation

    Microsoft Academic Search

    Tim Mcinerney; Demetri Terzopoulos

    1999-01-01

    Deformable models, which include deformable con- tours (the popular snakes) and deformable surfaces, are a power- ful model-based medical image analysis technique. We develop a new class of deformable models by formulating deformable sur- faces in terms of an affine cell image decomposition (ACID). Our approach significantly extends standard deformable surfaces, while retaining their interactivity and other desirable properties. In

  10. A Theoretical Solution to MAP-EM Partial Volume Segmentation of Medical Images

    PubMed Central

    Wang, Su; Lu, Hongyu; Liang, Zhengrong

    2009-01-01

    Voxels near tissue borders in medical images contain useful clinical information, but are subject to severe partial volume (PV) effect, which is a major cause of imprecision in quantitative volumetric and texture analysis. When modeling each tissue type as a conditionally independent Gaussian distribution, the tissue mixture fractions in each voxel via the modeled unobservable random processes of the underlying tissue types can be estimated by maximum a posteriori expectation-maximization (MAP-EM) algorithm in an iterative manner. This paper presents, based on the assumption that PV effect could be fully described by a tissue mixture model, a theoretical solution to the MAP-EM segmentation algorithm, as opposed to our previous approximation which simplified the posteriori cost function as a quadratic term. It was found out that the theoretically-derived solution existed in a set of high-order non-linear equations. Despite of the induced computational complexity when seeking for optimum numerical solutions to non-linear equations, potential gains in robustness, consistency and quantitative precision were noticed. Results from both synthetic digital phantoms and real patient bladder magnetic resonance images were presented, demonstrating the accuracy and efficiency of the presented theoretical MAP-EM solution. PMID:19768123

  11. Interactive navigation of segmented MR angiograms using simultaneous curved planar and volume visualizations

    Microsoft Academic Search

    Schooten van B. W; Dijk van E. M. A. G; A. Suinesiaputra; J. H. C. Reiber

    2011-01-01

    Purpose \\u000aInteractive visualization is required to inspect and monitor the automatic segmentation of vessels derived from contrast-enhanced magnetic resonance angiography (CE-MRA). A dual-view visualization scheme consisting of curved planar reformation (CPR) and direct volume rendering (DVR) was developed for this purpose and tested. \\u000a\\u000aMethods \\u000aA dual view visualization scheme was developed using the vessel pathline for both camera position and

  12. Microscopy image segmentation tool: Robust image data analysis

    SciTech Connect

    Valmianski, Ilya, E-mail: ivalmian@ucsd.edu; Monton, Carlos; Schuller, Ivan K. [Department of Physics and Center for Advanced Nanoscience, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093 (United States)] [Department of Physics and Center for Advanced Nanoscience, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093 (United States)

    2014-03-15

    We present a software package called Microscopy Image Segmentation Tool (MIST). MIST is designed for analysis of microscopy images which contain large collections of small regions of interest (ROIs). Originally developed for analysis of porous anodic alumina scanning electron images, MIST capabilities have been expanded to allow use in a large variety of problems including analysis of biological tissue, inorganic and organic film grain structure, as well as nano- and meso-scopic structures. MIST provides a robust segmentation algorithm for the ROIs, includes many useful analysis capabilities, and is highly flexible allowing incorporation of specialized user developed analysis. We describe the unique advantages MIST has over existing analysis software. In addition, we present a number of diverse applications to scanning electron microscopy, atomic force microscopy, magnetic force microscopy, scanning tunneling microscopy, and fluorescent confocal laser scanning microscopy.

  13. Microscopy image segmentation tool: Robust image data analysis

    NASA Astrophysics Data System (ADS)

    Valmianski, Ilya; Monton, Carlos; Schuller, Ivan K.

    2014-03-01

    We present a software package called Microscopy Image Segmentation Tool (MIST). MIST is designed for analysis of microscopy images which contain large collections of small regions of interest (ROIs). Originally developed for analysis of porous anodic alumina scanning electron images, MIST capabilities have been expanded to allow use in a large variety of problems including analysis of biological tissue, inorganic and organic film grain structure, as well as nano- and meso-scopic structures. MIST provides a robust segmentation algorithm for the ROIs, includes many useful analysis capabilities, and is highly flexible allowing incorporation of specialized user developed analysis. We describe the unique advantages MIST has over existing analysis software. In addition, we present a number of diverse applications to scanning electron microscopy, atomic force microscopy, magnetic force microscopy, scanning tunneling microscopy, and fluorescent confocal laser scanning microscopy.

  14. Spatiotemporal Analysis of Face Profiles: Detection, Segmentation, and Registration

    Microsoft Academic Search

    Behzad Dariush; Sing Bang Kang; Keith Waters

    1998-01-01

    We use a two-image approach to construct a 3D human facial model for multimedia applications. The images used are those of faces at direct frontal and side views. The selection of the side view from a sequence of facial images is automatically done by applying a spatiotemporal approach to face profile analysis. The extracted side profile is then segmented based

  15. Analysis of recent segmental duplications in the bovine genome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Duplicated sequences are an important source of gene innovation and structural variation within mammalian genomes. We describe the first systematic and genome-wide analysis of segmental duplications in the modern domesticated cattle (Bos taurus). Using two distinct computational analyses, we estimat...

  16. Mesoscale analysis of segmental dynamics in microphase-segregated polyurea

    E-print Network

    Grujicic, Mica

    Mesoscale analysis of segmental dynamics in microphase- segregated polyurea M. Grujicic · B-atom molecular dynamics techniques. To overcome this problem, mesoscale coarse-grain simulation methods of constituent atom-size particles. Within the mesoscale methods, on the other hand, this atomistic description

  17. The effect of segment parameter error on gait analysis results

    Microsoft Academic Search

    D. J Pearsall; P. A Costigan

    1999-01-01

    The extent to which errors in predicting body segment parameters (SP) influence biomechanical analysis of human motion is unclear. Therefore, the current study quantitatively evaluated the differences in SP estimates using literature predictive functions and computed the effect of SP variation on the kinetic output of walking. For a group of 15 young males, significant differences (P<0.05) were observed between

  18. Automated cerebellar segmentation: Validation and application to detect smaller volumes in children prenatally exposed to alcohol?

    PubMed Central

    Cardenas, Valerie A.; Price, Mathew; Infante, M. Alejandra; Moore, Eileen M.; Mattson, Sarah N.; Riley, Edward P.; Fein, George

    2014-01-01

    Objective To validate an automated cerebellar segmentation method based on active shape and appearance modeling and then segment the cerebellum on images acquired from adolescents with histories of prenatal alcohol exposure (PAE) and non-exposed controls (NC). Methods Automated segmentations of the total cerebellum, right and left cerebellar hemispheres, and three vermal lobes (anterior, lobules I–V; superior posterior, lobules VI–VII; inferior posterior, lobules VIII–X) were compared to expert manual labelings on 20 subjects, studied twice, that were not used for model training. The method was also used to segment the cerebellum on 11 PAE and 9 NC adolescents. Results The test–retest intraclass correlation coefficients (ICCs) of the automated method were greater than 0.94 for all cerebellar volume and mid-sagittal vermal area measures, comparable or better than the test–retest ICCs for manual measurement (all ICCs > 0.92). The ICCs computed on all four cerebellar measurements (manual and automated measures on the repeat scans) to compare comparability were above 0.97 for non-vermis parcels, and above 0.89 for vermis parcels. When applied to patients, the automated method detected smaller cerebellar volumes and mid-sagittal areas in the PAE group compared to controls (p < 0.05 for all regions except the superior posterior lobe, consistent with prior studies). Discussion These results demonstrate excellent reliability and validity of automated cerebellar volume and mid-sagittal area measurements, compared to manual measurements. These data also illustrate that this new technology for automatically delineating the cerebellum leads to conclusions regarding the effects of prenatal alcohol exposure on the cerebellum consistent with prior studies that used labor intensive manual delineation, even with a very small sample. PMID:25061566

  19. A novel colonic polyp volume segmentation method for computer tomographic colonography

    NASA Astrophysics Data System (ADS)

    Wang, Huafeng; Li, Lihong C.; Han, Hao; Song, Bowen; Peng, Hao; Wang, Yunhong; Wang, Lihua; Liang, Zhengrong

    2014-03-01

    Colorectal cancer is the third most common type of cancer. However, this disease can be prevented by detection and removal of precursor adenomatous polyps after the diagnosis given by experts on computer tomographic colonography (CTC). During CTC diagnosis, the radiologist looks for colon polyps and measures not only the size but also the malignancy. It is a common sense that to segment polyp volumes from their complicated growing environment is of much significance for accomplishing the CTC based early diagnosis task. Previously, the polyp volumes are mainly given from the manually or semi-automatically drawing by the radiologists. As a result, some deviations cannot be avoided since the polyps are usually small (6~9mm) and the radiologists' experience and knowledge are varying from one to another. In order to achieve automatic polyp segmentation carried out by the machine, we proposed a new method based on the colon decomposition strategy. We evaluated our algorithm on both phantom and patient data. Experimental results demonstrate our approach is capable of segment the small polyps from their complicated growing background.

  20. Documented Safety Analysis for the B695 Segment

    SciTech Connect

    Laycak, D

    2008-09-11

    This Documented Safety Analysis (DSA) was prepared for the Lawrence Livermore National Laboratory (LLNL) Building 695 (B695) Segment of the Decontamination and Waste Treatment Facility (DWTF). The report provides comprehensive information on design and operations, including safety programs and safety structures, systems and components to address the potential process-related hazards, natural phenomena, and external hazards that can affect the public, facility workers, and the environment. Consideration is given to all modes of operation, including the potential for both equipment failure and human error. The facilities known collectively as the DWTF are used by LLNL's Radioactive and Hazardous Waste Management (RHWM) Division to store and treat regulated wastes generated at LLNL. RHWM generally processes low-level radioactive waste with no, or extremely low, concentrations of transuranics (e.g., much less than 100 nCi/g). Wastes processed often contain only depleted uranium and beta- and gamma-emitting nuclides, e.g., {sup 90}Sr, {sup 137}Cs, or {sup 3}H. The mission of the B695 Segment centers on container storage, lab-packing, repacking, overpacking, bulking, sampling, waste transfer, and waste treatment. The B695 Segment is used for storage of radioactive waste (including transuranic and low-level), hazardous, nonhazardous, mixed, and other waste. Storage of hazardous and mixed waste in B695 Segment facilities is in compliance with the Resource Conservation and Recovery Act (RCRA). LLNL is operated by the Lawrence Livermore National Security, LLC, for the Department of Energy (DOE). The B695 Segment is operated by the RHWM Division of LLNL. Many operations in the B695 Segment are performed under a Resource Conservation and Recovery Act (RCRA) operation plan, similar to commercial treatment operations with best demonstrated available technologies. The buildings of the B695 Segment were designed and built considering such operations, using proven building systems, and keeping them as simple as possible while complying with industry standards and institutional requirements. No operations to be performed in the B695 Segment or building system are considered to be complex. No anticipated future change in the facility mission is expected to impact the extent of safety analysis documented in this DSA.

  1. The segmented regional volumes of the cerebrum and cerebellum in boys with Tourette syndrome.

    PubMed Central

    Hong, Kang-E; Ock, Sun-Myeong; Kang, Min-Hee; Kim, Chul-Eung; Bae, Jae-Nam; Lim, Myung-Kwan; Suh, Chang-Hae; Chung, Sun-Ju; Cho, Soo-Churl; Lee, Jeong-Seop

    2002-01-01

    Neuropathological deficits are an etiological factor in Tourette syndrome (TS), and implicate a network linking the basal ganglia and the cerebrum, not a particular single brain region. In this study, the volumes of 20 cerebral and cerebellar regions and their symmetries were measured in normal boys and TS boys by brain magnetic resonance imaging. Brain magnetic resonance images were obtained prospectively in 19 boys with TS and 17 age-matched normal control boys. Cerebral and cerebellar regions were segmented to gray and white fractions using algorithm for semi-automated fuzzy tissue segmentation. The frontal, parietal, temporal, and the occipital lobes and the cerebellum were defined using the semiautomated Talairach atlas-based parcellation method. Boys with TS had smaller total brain volumes than control subjects. In the gray matter, although the smaller brain volume was taken into account, TS boys had a smaller right frontal lobe and a larger left frontal lobe and increased normal asymmetry (left>right). In addition, TS boys had more frontal lobe white matter. There were no significant differences in regions of interest of the parietal, temporal, or the occipital lobes or the cerebellum. These findings suggest that boys with TS may have neuropathological abnormalities in the gray and the white matter of the frontal lobe. PMID:12172051

  2. Automatic Segmentation and Quantitative Analysis of the Articular Cartilages From Magnetic Resonance Images of the Knee

    PubMed Central

    Fripp, Jurgen; Crozier, Stuart; Warfield, Simon K.; Ourselin, Sébastien

    2010-01-01

    In this paper, we present a segmentation scheme that automatically and accurately segments all the cartilages from magnetic resonance (MR) images of nonpathological knees. Our scheme involves the automatic segmentation of the bones using a three-dimensional active shape model, the extraction of the expected bone-cartilage interface (BCI), and cartilage segmentation from the BCI using a deformable model that utilizes localization, patient specific tissue estimation and a model of the thickness variation. The accuracy of this scheme was experimentally validated using leave one out experiments on a database of fat suppressed spoiled gradient recall MR images. The scheme was compared to three state of the art approaches, tissue classification, a modified semi-automatic watershed algorithm and nonrigid registration (B-spline based free form deformation). Our scheme obtained an average Dice similarity coefficient (DSC) of (0.83, 0.83, 0.85) for the (patellar, tibial, femoral) cartilages, while (0.82, 0.81, 0.86) was obtained with a tissue classifier and (0.73, 0.79, 0.76) was obtained with nonrigid registration. The average DSC obtained for all the cartilages using a semi-automatic watershed algorithm (0.90) was slightly higher than our approach (0.89), however unlike this approach we segment each cartilage as a separate object. The effectiveness of our approach for quantitative analysis was evaluated using volume and thickness measures with a median volume difference error of (5.92, 4.65, 5.69) and absolute Laplacian thickness difference of (0.13, 0.24, 0.12) mm. PMID:19520633

  3. Segmented canonical discriminant analysis of in situ hyperspectral data for identifying 13 urban tree species

    Microsoft Academic Search

    Ruiliang Pu; Desheng Liu

    2011-01-01

    A total of 458 in situ hyperspectral data were collected from 13 urban tree species in the City of Tampa, FL, USA using a spectrometer. The 13 species include 11 broadleaf and two conifer species. Three different techniques, segmented canonical discriminant analysis (CDA), segmented principal component analysis (PCA) and segmented stepwise discriminate analysis (SDA), were applied and compared for dimension

  4. Interactive navigation of segmented MR angiograms using simultaneous curved planar and volume visualizations

    Microsoft Academic Search

    B. W. van Schooten; E. M. A. G. van Dijk; A. Suinesiaputra; J. H. C. Reiber

    Purpose  Interactive visualization is required to inspect and monitor the automatic segmentation of vessels derived from contrast-enhanced\\u000a magnetic resonance angiography (CE-MRA). A dual-view visualization scheme consisting of curved planar reformation (CPR) and\\u000a direct volume rendering (DVR) was developed for this purpose and tested.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  A dual view visualization scheme was developed using the vessel pathline for both camera position and rotation in

  5. Automatic comic page image understanding based on edge segment analysis

    NASA Astrophysics Data System (ADS)

    Liu, Dong; Wang, Yongtao; Tang, Zhi; Li, Luyuan; Gao, Liangcai

    2013-12-01

    Comic page image understanding aims to analyse the layout of the comic page images by detecting the storyboards and identifying the reading order automatically. It is the key technique to produce the digital comic documents suitable for reading on mobile devices. In this paper, we propose a novel comic page image understanding method based on edge segment analysis. First, we propose an efficient edge point chaining method to extract Canny edge segments (i.e., contiguous chains of Canny edge points) from the input comic page image; second, we propose a top-down scheme to detect line segments within each obtained edge segment; third, we develop a novel method to detect the storyboards by selecting the border lines and further identify the reading order of these storyboards. The proposed method is performed on a data set consisting of 2000 comic page images from ten printed comic series. The experimental results demonstrate that the proposed method achieves satisfactory results on different comics and outperforms the existing methods.

  6. 4-D segmentation and normalization of 3He MR images for intrasubject assessment of ventilated lung volumes

    NASA Astrophysics Data System (ADS)

    Contrella, Benjamin; Tustison, Nicholas J.; Altes, Talissa A.; Avants, Brian B.; Mugler, John P., III; de Lange, Eduard E.

    2012-03-01

    Although 3He MRI permits compelling visualization of the pulmonary air spaces, quantitation of absolute ventilation is difficult due to confounds such as field inhomogeneity and relative intensity differences between image acquisition; the latter complicating longitudinal investigations of ventilation variation with respiratory alterations. To address these potential difficulties, we present a 4-D segmentation and normalization approach for intra-subject quantitative analysis of lung hyperpolarized 3He MRI. After normalization, which combines bias correction and relative intensity scaling between longitudinal data, partitioning of the lung volume time series is performed by iterating between modeling of the combined intensity histogram as a Gaussian mixture model and modulating the spatial heterogeneity tissue class assignments through Markov random field modeling. Evaluation of the algorithm was retrospectively applied to a cohort of 10 asthmatics between 19-25 years old in which spirometry and 3He MR ventilation images were acquired both before and after respiratory exacerbation by a bronchoconstricting agent (methacholine). Acquisition was repeated under the same conditions from 7 to 467 days (mean +/- standard deviation: 185 +/- 37.2) later. Several techniques were evaluated for matching intensities between the pre and post-methacholine images with the 95th percentile value histogram matching demonstrating superior correlations with spirometry measures. Subsequent analysis evaluated segmentation parameters for assessing ventilation change in this cohort. Current findings also support previous research that areas of poor ventilation in response to bronchoconstriction are relatively consistent over time.

  7. Partial volume segmentation of brain magnetic resonance images based on maximum a posteriori probability

    SciTech Connect

    Li Xiang; Li Lihong; Lu Hongbing; Liang Zhengrong [Department of Radiology, State University of New York at Stony Brook, Stony Brook, New York, 11794 and Department of Radiation Oncology, Columbia University, New York, New York, 10032 (United States); Department of Radiology, State University of New York at Stony Brook, Stony Brook, New York, 11794 and Department of Engineering Science and Physics, College of Staten Island of the City University of New York, Staten Island, New York 10314 (United States); Department of Radiology, State University of New York at Stony Brook, Stony Brook, New York 11794 and Department of Biomedical Engineering/Computer Application, Fourth Military Medical University, Xi'an, Shaanxi 710032 (China); Department of Radiology, State University of New York at Stony Brook, Stony Brook, New York 11794 (United States)

    2005-07-15

    Noise, partial volume (PV) effect, and image-intensity inhomogeneity render a challenging task for segmentation of brain magnetic resonance (MR) images. Most of the current MR image segmentation methods focus on only one or two of the above-mentioned effects. The objective of this paper is to propose a unified framework, based on the maximum a posteriori probability principle, by taking all these effects into account simultaneously in order to improve image segmentation performance. Instead of labeling each image voxel with a unique tissue type, the percentage of each voxel belonging to different tissues, which we call a mixture, is considered to address the PV effect. A Markov random field model is used to describe the noise effect by considering the nearby spatial information of the tissue mixture. The inhomogeneity effect is modeled as a bias field characterized by a zero mean Gaussian prior probability. The well-known fuzzy C-mean model is extended to define the likelihood function of the observed image. This framework reduces theoretically, under some assumptions, to the adaptive fuzzy C-mean (AFCM) algorithm proposed by Pham and Prince. Digital phantom and real clinical MR images were used to test the proposed framework. Improved performance over the AFCM algorithm was observed in a clinical environment where the inhomogeneity, noise level, and PV effect are commonly encountered.

  8. Automatic delineation of tumor volumes by co-segmentation of combined PET/MR data

    NASA Astrophysics Data System (ADS)

    Leibfarth, S.; Eckert, F.; Welz, S.; Siegel, C.; Schmidt, H.; Schwenzer, N.; Zips, D.; Thorwarth, D.

    2015-07-01

    Combined PET/MRI may be highly beneficial for radiotherapy treatment planning in terms of tumor delineation and characterization. To standardize tumor volume delineation, an automatic algorithm for the co-segmentation of head and neck (HN) tumors based on PET/MR data was developed. Ten HN patient datasets acquired in a combined PET/MR system were available for this study. The proposed algorithm uses both the anatomical T2-weighted MR and FDG-PET data. For both imaging modalities tumor probability maps were derived, assigning each voxel a probability of being cancerous based on its signal intensity. A combination of these maps was subsequently segmented using a threshold level set algorithm. To validate the method, tumor delineations from three radiation oncologists were available. Inter-observer variabilities and variabilities between the algorithm and each observer were quantified by means of the Dice similarity index and a distance measure. Inter-observer variabilities and variabilities between observers and algorithm were found to be comparable, suggesting that the proposed algorithm is adequate for PET/MR co-segmentation. Moreover, taking into account combined PET/MR data resulted in more consistent tumor delineations compared to MR information only.

  9. Automatic delineation of tumor volumes by co-segmentation of combined PET/MR data.

    PubMed

    Leibfarth, S; Eckert, F; Welz, S; Siegel, C; Schmidt, H; Schwenzer, N; Zips, D; Thorwarth, D

    2015-07-01

    Combined PET/MRI may be highly beneficial for radiotherapy treatment planning in terms of tumor delineation and characterization. To standardize tumor volume delineation, an automatic algorithm for the co-segmentation of head and neck (HN) tumors based on PET/MR data was developed. Ten HN patient datasets acquired in a combined PET/MR system were available for this study. The proposed algorithm uses both the anatomical T2-weighted MR and FDG-PET data. For both imaging modalities tumor probability maps were derived, assigning each voxel a probability of being cancerous based on its signal intensity. A combination of these maps was subsequently segmented using a threshold level set algorithm. To validate the method, tumor delineations from three radiation oncologists were available. Inter-observer variabilities and variabilities between the algorithm and each observer were quantified by means of the Dice similarity index and a distance measure. Inter-observer variabilities and variabilities between observers and algorithm were found to be comparable, suggesting that the proposed algorithm is adequate for PET/MR co-segmentation. Moreover, taking into account combined PET/MR data resulted in more consistent tumor delineations compared to MR information only. PMID:26111013

  10. Segmentation of interest region in medical volume images using geometric deformable model.

    PubMed

    Lee, Myungeun; Cho, Wanhyun; Kim, Sunworl; Park, Soonyoung; Kim, Jong Hyo

    2012-05-01

    In this paper, we present a new segmentation method using the level set framework for medical volume images. The method was implemented using the surface evolution principle based on the geometric deformable model and the level set theory. And, the speed function in the level set approach consists of a hybrid combination of three integral measures derived from the calculus of variation principle. The terms are defined as robust alignment, active region, and smoothing. These terms can help to obtain the precise surface of the target object and prevent the boundary leakage problem. The proposed method has been tested on synthetic and various medical volume images with normal tissue and tumor regions in order to evaluate its performance on visual and quantitative data. The quantitative validation of the proposed segmentation is shown with higher Jaccard's measure score (72.52%-94.17%) and lower Hausdorff distance (1.2654 mm-3.1527 mm) than the other methods such as mean speed (67.67%-93.36% and 1.3361mm-3.4463 mm), mean-variance speed (63.44%-94.72% and 1.3361 mm-3.4616 mm), and edge-based speed (0.76%-42.44% and 3.8010 mm-6.5389 mm). The experimental results confirm that the effectiveness and performance of our method is excellent compared with traditional approaches. PMID:22402196

  11. Atlas-based automatic segmentation of head and neck organs at risk and nodal target volumes: a clinical validation

    PubMed Central

    2013-01-01

    Background Intensity modulated radiotherapy for head and neck cancer necessitates accurate definition of organs at risk (OAR) and clinical target volumes (CTV). This crucial step is time consuming and prone to inter- and intra-observer variations. Automatic segmentation by atlas deformable registration may help to reduce time and variations. We aim to test a new commercial atlas algorithm for automatic segmentation of OAR and CTV in both ideal and clinical conditions. Methods The updated Brainlab automatic head and neck atlas segmentation was tested on 20 patients: 10 cN0-stages (ideal population) and 10 unselected N-stages (clinical population). Following manual delineation of OAR and CTV, automatic segmentation of the same set of structures was performed and afterwards manually corrected. Dice Similarity Coefficient (DSC), Average Surface Distance (ASD) and Maximal Surface Distance (MSD) were calculated for “manual to automatic” and “manual to corrected” volumes comparisons. Results In both groups, automatic segmentation saved about 40% of the corresponding manual segmentation time. This effect was more pronounced for OAR than for CTV. The edition of the automatically obtained contours significantly improved DSC, ASD and MSD. Large distortions of normal anatomy or lack of iodine contrast were the limiting factors. Conclusions The updated Brainlab atlas-based automatic segmentation tool for head and neck Cancer patients is timesaving but still necessitates review and corrections by an expert. PMID:23803232

  12. Segmented PCA-based compression for hyperspectral image analysis

    Microsoft Academic Search

    Qian Du; Chein-I. Chang

    2004-01-01

    Hyperspectral images have high spectral resolution that helps to improve object classification. But its vast data volume also causes problems in data transmission and data storage. Since there is high correlation among spectral bands in a hyperspectral image, how to reduce the data redundancy while keeping the important information for the following data analysis is a challenging task. In this

  13. Linear test bed. Volume 1: Test bed no. 1. [aerospike test bed with segmented combustor

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The Linear Test Bed program was to design, fabricate, and evaluation test an advanced aerospike test bed which employed the segmented combustor concept. The system is designated as a linear aerospike system and consists of a thrust chamber assembly, a power package, and a thrust frame. It was designed as an experimental system to demonstrate the feasibility of the linear aerospike-segmented combustor concept. The overall dimensions are 120 inches long by 120 inches wide by 96 inches in height. The propellants are liquid oxygen/liquid hydrogen. The system was designed to operate at 1200-psia chamber pressure, at a mixture ratio of 5.5. At the design conditions, the sea level thrust is 200,000 pounds. The complete program including concept selection, design, fabrication, component test, system test, supporting analysis and posttest hardware inspection is described.

  14. Processing plutonium-contaminated soild for volume reduction using the segmented gate system

    SciTech Connect

    Moroney, K.S.; Moroney, J.D.; Turney, J.M.; Doane, R.W. [Thermo Analytical, Inc., Albuquerque, NM (United States)

    1994-12-31

    TMA/Eberline has developed and demonstrated an effective method for removing mixed plutonium and americium contamination from a coral soil matrix at the Defense Nuclear Agency`s Johnston Atoll site. TMA`s onsite soil processing for volume reduction is ongoing at a rate of over 2000 metric tons per week. The system uses arrays of sensitive radiation detectors coupled with sophisticated computer software developed by Eberline Instrument Corporation. The proprietary software controls four soil sorting units operating in parallel that utilize TMA`s unique Segmented Gate System technology to remove radiologically contaminated soil from a moving supply on conveyor belts. Clean soil is released for use elsewhere on the island. Contaminated soil is diverted to either a metal drum for collecting higher activity {open_quotes}hot{close_quotes} particles (>5000 Becquerels), or to a supplementary soil washing process designed to remove finely divided particles of dispersed low level contamination. Site contamination limits specify maximum dispersed radioactivity of no more than 500 Becquerels per kilogram of soil averaged over no more than 0.1 cubic meter. Results of soil processing at this site have been excellent. After processing over 50,000 metric tons, the volume of contaminated material that would have required expensive special handling, packaging, and disposal as radioactive waste has been successfully reduced by over 98 percent. By mid-January 1994, nearly three million kiloBecquerels of plutonium/americium contamination had been physically separated from the contaminated feed by TMA`s Segmented Gate System, and quality control sampling showed no radioactivity above release criteria in the {open_quotes}clean{close_quotes} soil pile.

  15. Analysis of Methods for Reducing Line Segments in Maps: Towards a General Approach

    E-print Network

    Paris-Sud XI, Université de

    Analysis of Methods for Reducing Line Segments in Maps: Towards a General Approach Francesco method for reducing the number of redundant line segments in maps. In particular, we survey the most^one-Alpes, Grenoble, France. simone.gasparini@inrialpes.fr. general method for fusing line segments in maps. Hence

  16. Comparative assessment of statistical brain MR image segmentation algorithms and their impact on partial volume correction in PET

    Microsoft Academic Search

    Habib Zaidi; Torsten Ruest; Frederic Schoenahl; Marie-Louise Montandon

    2006-01-01

    Magnetic resonance imaging (MRI)-guided partial volume effect correction (PVC) in brain positron emission tomography (PET) is now a well-established approach to compensate the large bias in the estimate of regional radioactivity concentration, especially for small structures. The accuracy of the algorithms developed so far is, however, largely dependent on the performance of segmentation methods partitioning MRI brain data into its

  17. Image segmentation by iterative parallel region growing with application to data compression and image analysis

    NASA Technical Reports Server (NTRS)

    Tilton, James C.

    1988-01-01

    Image segmentation can be a key step in data compression and image analysis. However, the segmentation results produced by most previous approaches to region growing are suspect because they depend on the order in which portions of the image are processed. An iterative parallel segmentation algorithm avoids this problem by performing globally best merges first. Such a segmentation approach, and two implementations of the approach on NASA's Massively Parallel Processor (MPP) are described. Application of the segmentation approach to data compression and image analysis is then described, and results of such application are given for a LANDSAT Thematic Mapper image.

  18. Genetic and expression analysis of enabled in Drosophila leg segmentation

    E-print Network

    Ramel, Marie-Christine

    2001-01-01

    Drosophila leg segmentation is a process which is beginning to be understood. The Notch (N) signaling pathway has been identified as a key regulator of joint formation and segmental growth in Drosophila legs. In this context, four-jointed (fj...

  19. Study of tracking and data acquisition system for the 1990's. Volume 4: TDAS space segment architecture

    NASA Technical Reports Server (NTRS)

    Orr, R. S.

    1984-01-01

    Tracking and data acquisition system (TDAS) requirements, TDAS architectural goals, enhanced TDAS subsystems, constellation and networking options, TDAS spacecraft options, crosslink implementation, baseline TDAS space segment architecture, and treat model development/security analysis are addressed.

  20. A boosted segmentation method for surgical workflow analysis.

    PubMed

    Padoy, N; Blum, T; Essa, I; Feussner, H; Berger, M O; Navab, N

    2007-01-01

    As demands on hospital efficiency increase, there is a stronger need for automatic analysis, recovery, and modification of surgical workflows. Even though most of the previous work has dealt with higher level and hospital-wide workflow including issues like document management, workflow is also an important issue within the surgery room. Its study has a high potential, e.g., for building context-sensitive operating rooms, evaluating and training surgical staff, optimizing surgeries and generating automatic reports. In this paper we propose an approach to segment the surgical workflow into phases based on temporal synchronization of multidimensional state vectors. Our method is evaluated on the example of laparoscopic cholecystectomy with state vectors representing tool usage during the surgeries. The discriminative power of each instrument in regard to each phase is estimated using AdaBoost. A boosted version of the Dynamic Time Warping (DTW) algorithm is used to create a surgical reference model and to segment a newly observed surgery. Full cross-validation on ten surgeries is performed and the method is compared to standard DTW and to Hidden Markov Models. PMID:18051049

  1. Functional Analysis of the Vertebral Column based on MR and Direct Volume Rendering

    E-print Network

    Blanz, Volker

    Functional Analysis of the Vertebral Column based on MR and Direct Volume Rendering P. Hastreiter1 of Neurosurgery, University of Erlangen­Nuremberg, Germany Abstract. Degenerative diseases of the vertebral column providing important functional information about the motion of vertebral segments. Avoid this time

  2. Three dimensional level set based semiautomatic segmentation of atherosclerotic carotid artery wall volume using 3D ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Hossain, Md. Murad; AlMuhanna, Khalid; Zhao, Limin; Lal, Brajesh K.; Sikdar, Siddhartha

    2014-03-01

    3D segmentation of carotid plaque from ultrasound (US) images is challenging due to image artifacts and poor boundary definition. Semiautomatic segmentation algorithms for calculating vessel wall volume (VWV) have been proposed for the common carotid artery (CCA) but they have not been applied on plaques in the internal carotid artery (ICA). In this work, we describe a 3D segmentation algorithm that is robust to shadowing and missing boundaries. Our algorithm uses distance regularized level set method with edge and region based energy to segment the adventitial wall boundary (AWB) and lumen-intima boundary (LIB) of plaques in the CCA, ICA and external carotid artery (ECA). The algorithm is initialized by manually placing points on the boundary of a subset of transverse slices with an interslice distance of 4mm. We propose a novel user defined stopping surface based energy to prevent leaking of evolving surface across poorly defined boundaries. Validation was performed against manual segmentation using 3D US volumes acquired from five asymptomatic patients with carotid stenosis using a linear 4D probe. A pseudo gold-standard boundary was formed from manual segmentation by three observers. The Dice similarity coefficient (DSC), Hausdor distance (HD) and modified HD (MHD) were used to compare the algorithm results against the pseudo gold-standard on 1205 cross sectional slices of 5 3D US image sets. The algorithm showed good agreement with the pseudo gold standard boundary with mean DSC of 93.3% (AWB) and 89.82% (LIB); mean MHD of 0.34 mm (AWB) and 0.24 mm (LIB); mean HD of 1.27 mm (AWB) and 0.72 mm (LIB). The proposed 3D semiautomatic segmentation is the first step towards full characterization of 3D plaque progression and longitudinal monitoring.

  3. Non-invasive measurement of choroidal volume change and ocular rigidity through automated segmentation of high-speed OCT imaging

    PubMed Central

    Beaton, L.; Mazzaferri, J.; Lalonde, F.; Hidalgo-Aguirre, M.; Descovich, D.; Lesk, M. R.; Costantino, S.

    2015-01-01

    We have developed a novel optical approach to determine pulsatile ocular volume changes using automated segmentation of the choroid, which, together with Dynamic Contour Tonometry (DCT) measurements of intraocular pressure (IOP), allows estimation of the ocular rigidity (OR) coefficient. Spectral Domain Optical Coherence Tomography (OCT) videos were acquired with Enhanced Depth Imaging (EDI) at 7Hz during ~50 seconds at the fundus. A novel segmentation algorithm based on graph search with an edge-probability weighting scheme was developed to measure choroidal thickness (CT) at each frame. Global ocular volume fluctuations were derived from frame-to-frame CT variations using an approximate eye model. Immediately after imaging, IOP and ocular pulse amplitude (OPA) were measured using DCT. OR was calculated from these peak pressure and volume changes. Our automated segmentation algorithm provides the first non-invasive method for determining ocular volume change due to pulsatile choroidal filling, and the estimation of the OR constant. Future applications of this method offer an important avenue to understanding the biomechanical basis of ocular pathophysiology. PMID:26137373

  4. Effect of Volume and Temperature on the Global and Segmental Dynamics in Polypropylene Glycol and 1,4-polyisoprene

    E-print Network

    C. M. Roland; R. Casalini; M. Paluch

    2004-04-07

    Published dielectric relaxation measurements on polypropylene glycol and 1,4-polyisoprene are analyzed to determine the relative effect that thermal energy and volume have on the temperature dependence of the normal mode relaxation times, and compare this to their effect on the temperature dependence of the local segmental relaxation times. We find that for both polymers at temperatures well above Tg, both relaxation modes are governed more by thermal energy than by volume, although the latter's contribution is not negligible. Such a result is consistent with an assumption underlying models for polymer viscoelasticity, such as the Rouse and tube models, that the friction coefficient governing motions over large length scales can be identified with the local segmental friction coefficient. We also show that relaxation data for both the segmental and the normal mode superimpose, when expressed as a function of the product of the temperature and the volume, the latter raised to a power. This scaling form arises from an inverse power form for the intermolecular potential. The value of the exponent on the volume for these two polymers indicates a relatively "soft" potential.

  5. Object density-based image segmentation and its applications in biomedical image analysis.

    PubMed

    Yu, Jinhua; Tan, Jinglu

    2009-12-01

    In many applications of medical image analysis, the density of an object is the most important feature for isolating an area of interest (image segmentation). In this research, an object density-based image segmentation methodology is developed, which incorporates intensity-based, edge-based and texture-based segmentation techniques. The proposed method consists of three main stages: preprocessing, object segmentation and final segmentation. Image enhancement, noise reduction and layer-of-interest extraction are several subtasks of preprocessing. Object segmentation utilizes a marker-controlled watershed technique to identify each object of interest (OI) from the background. A marker estimation method is proposed to minimize over-segmentation resulting from the watershed algorithm. Object segmentation provides an accurate density estimation of OI which is used to guide the subsequent segmentation steps. The final stage converts the distribution of OI into textural energy by using fractal dimension analysis. An energy-driven active contour procedure is designed to delineate the area with desired object density. Experimental results show that the proposed method is 98% accurate in segmenting synthetic images. Segmentation of microscopic images and ultrasound images shows the potential utility of the proposed method in different applications of medical image processing. PMID:19473717

  6. Automated detection, 3D segmentation and analysis of high resolution spine MR images using statistical shape models

    NASA Astrophysics Data System (ADS)

    Neubert, A.; Fripp, J.; Engstrom, C.; Schwarz, R.; Lauer, L.; Salvado, O.; Crozier, S.

    2012-12-01

    Recent advances in high resolution magnetic resonance (MR) imaging of the spine provide a basis for the automated assessment of intervertebral disc (IVD) and vertebral body (VB) anatomy. High resolution three-dimensional (3D) morphological information contained in these images may be useful for early detection and monitoring of common spine disorders, such as disc degeneration. This work proposes an automated approach to extract the 3D segmentations of lumbar and thoracic IVDs and VBs from MR images using statistical shape analysis and registration of grey level intensity profiles. The algorithm was validated on a dataset of volumetric scans of the thoracolumbar spine of asymptomatic volunteers obtained on a 3T scanner using the relatively new 3D T2-weighted SPACE pulse sequence. Manual segmentations and expert radiological findings of early signs of disc degeneration were used in the validation. There was good agreement between manual and automated segmentation of the IVD and VB volumes with the mean Dice scores of 0.89 ± 0.04 and 0.91 ± 0.02 and mean absolute surface distances of 0.55 ± 0.18 mm and 0.67 ± 0.17 mm respectively. The method compares favourably to existing 3D MR segmentation techniques for VBs. This is the first time IVDs have been automatically segmented from 3D volumetric scans and shape parameters obtained were used in preliminary analyses to accurately classify (100% sensitivity, 98.3% specificity) disc abnormalities associated with early degenerative changes.

  7. Swept Volume Parameterization for Isogeometric Analysis

    NASA Astrophysics Data System (ADS)

    Aigner, M.; Heinrich, C.; Jüttler, B.; Pilgerstorfer, E.; Simeon, B.; Vuong, A.-V.

    Isogeometric Analysis uses NURBS representations of the domain for performing numerical simulations. The first part of this paper presents a variational framework for generating NURBS parameterizations of swept volumes. The class of these volumes covers a number of interesting free-form shapes, such as blades of turbines and propellers, ship hulls or wings of airplanes. The second part of the paper reports the results of isogeometric analysis which were obtained with the help of the generated NURBS volume parameterizations. In particular we discuss the influence of the chosen parameterization and the incorporation of boundary conditions.

  8. Segmentation and analysis of emission-computed-tomography images

    NASA Astrophysics Data System (ADS)

    Johnson, Valen E.; Bowsher, James E.; Qian, Jiang; Jaszczak, Ronald J.

    1992-12-01

    This paper describes a statistical model for reconstruction of emission computed tomography (ECT) images. A distinguishing feature of this model is that it is parameterized in terms of quantities of direct physiological significance, rather than only in terms of grey-level voxel values. Specifically, parameters representing regions, region means, and region volumes are included in the model formulation and are estimated directly from projection data. The model is specified hierarchically within the Bayesian paradigm. At the lowest level of the hierarchy, a Gibbs distribution is employed to specify a probability distribution on the space of all possible partitions of the discretized image scene. A novel feature of this distribution is that the number of partitioning elements, or image regions, is not assumed known a priori. In contrast, any other segmentation models (e.g., Liang et al., 1991, Amit et al., 1991) require that the number of regions be specified prior to image reconstruction. Since the number of regions in a source distribution is seldom known a priori, allowing the number of regions to vary within the model framework is an important practical feature of this model. In the second level of the model hierarchy, random variables representing emission intensity are associated with each partitioning element or region. Individual voxel intensities are assumed to be drawn from a gamma distribution with mean equal to the region mean in the third stage, and in the final stage of the hierarchy projection data are assumed to be generated from Poisson distributions with means equal to weighted sums of voxel intensities.

  9. Fractal Segmentation and Clustering Analysis for Seismic Time Slices

    NASA Astrophysics Data System (ADS)

    Ronquillo, G.; Oleschko, K.; Korvin, G.; Arizabalo, R. D.

    2002-05-01

    Fractal analysis has become part of the standard approach for quantifying texture on gray-tone or colored images. In this research we introduce a multi-stage fractal procedure to segment, classify and measure the clustering patterns on seismic time slices from a 3-D seismic survey. Five fractal classifiers (c1)-(c5) were designed to yield standardized, unbiased and precise measures of the clustering of seismic signals. The classifiers were tested on seismic time slices from the AKAL field, Cantarell Oil Complex, Mexico. The generalized lacunarity (c1), fractal signature (c2), heterogeneity (c3), rugosity of boundaries (c4) and continuity resp. tortuosity (c5) of the clusters are shown to be efficient measures of the time-space variability of seismic signals. The Local Fractal Analysis (LFA) of time slices has proved to be a powerful edge detection filter to detect and enhance linear features, like faults or buried meandering rivers. The local fractal dimensions of the time slices were also compared with the self-affinity dimensions of the corresponding parts of porosity-logs. It is speculated that the spectral dimension of the negative-amplitude parts of the time-slice yields a measure of connectivity between the formation's high-porosity zones, and correlates with overall permeability.

  10. 3D Method of Using Spatial-Varying Gaussian Mixture and Local Information to Segment MR Brain Volumes

    Microsoft Academic Search

    Zhigang Peng; Xiang Cai; William G. Wee; Jing-huei Lee

    2006-01-01

    \\u000a The paper is an extension of previous work on spatial-varying Gaussian mixture and Markov random field (SVGM-MRF) from 2D\\u000a to 3D to segment the MR brain volume with the presence of noise and inhomogeneity. The reason for this extension is that MR\\u000a brain data are naturally three dimensional, and the information from the additional dimension provides a more accurate conditional

  11. Segmental chloride and fluid handling during correction of chloride-depletion alkalosis without volume expansion in the rat.

    PubMed Central

    Galla, J H; Bonduris, D N; Dumbauld, S L; Luke, R G

    1984-01-01

    To determine whether chloride-depletion metabolic alkalosis (CDA) can be corrected by provision of chloride without volume expansion or intranephronal redistribution of fluid reabsorption, CDA was produced in Sprague-Dawley rats by peritoneal dialysis against 0.15 M NaHCO3; controls (CON) were dialyzed against Ringer's bicarbonate. Animals were infused with isotonic solutions containing the same Cl and total CO2 (tCO2) concentrations as in postdialysis plasma at rates shown to be associated with slight but stable volume contraction. During the subsequent 6 h, serum Cl and tCO2 concentrations remained stable and normal in CON and corrected towards normal in CDA; urinary chloride excretion was less and bicarbonate excretion greater than those in CON during this period. Micropuncture and microinjection studies were performed in the 3rd h after dialysis. Plasma volumes determined by 125I-albumin were not different. Inulin clearance and fractional chloride excretion were lower (P less than 0.05) in CDA. Superficial nephron glomerular filtration rate determined from distal puncture sites was lower (P less than 0.02) in CDA (27.9 +/- 2.3 nl/min) compared with that in CON (37.9 +/- 2.6). Fractional fluid and chloride reabsorption in the proximal convoluted tubule and within the loop segment did not differ. Fractional chloride delivery to the early distal convolution did not differ but that out of this segment was less (P less than 0.01) in group CDA. Urinary recovery of 36Cl injected into the collecting duct segment was lower (P less than 0.01) in CDA (CON 74 +/- 3; CDA 34 +/- 4%). These data show that CDA can be corrected by the provision of chloride without volume expansion or alterations in the intranephronal distribution of fluid reabsorption. Enhanced chloride reabsorption in the collecting duct segment, and possibly in the distal convoluted tubule, contributes importantly to this correction. PMID:6690486

  12. Analysis of image thresholding segmentation algorithms based on swarm intelligence

    NASA Astrophysics Data System (ADS)

    Zhang, Yi; Lu, Kai; Gao, Yinghui; Yang, Bo

    2013-03-01

    Swarm intelligence-based image thresholding segmentation algorithms are playing an important role in the research field of image segmentation. In this paper, we briefly introduce the theories of four existing image segmentation algorithms based on swarm intelligence including fish swarm algorithm, artificial bee colony, bacteria foraging algorithm and particle swarm optimization. Then some image benchmarks are tested in order to show the differences of the segmentation accuracy, time consumption, convergence and robustness for Salt & Pepper noise and Gaussian noise of these four algorithms. Through these comparisons, this paper gives qualitative analyses for the performance variance of the four algorithms. The conclusions in this paper would give a significant guide for the actual image segmentation.

  13. Macrostructural EEG characterization based on nonparametric change point segmentation: application to sleep analysis

    Microsoft Academic Search

    A. Kaplan; J. Röschke; B. Darkhovsky; J. Fell

    2001-01-01

    In the present investigation a new methodology for macrostructural EEG characterization based on automatic segmentation has been applied to sleep analysis. A nonparametric statistical approach for EEG segmentation was chosen, because it minimizes the need for a priori information about a signal. The method provides the detection of change-points i.e. boundaries between quasi-stationary EEG segments based on the EEG characteristics

  14. Recurrence interval analysis of trading volumes.

    PubMed

    Ren, Fei; Zhou, Wei-Xing

    2010-06-01

    We study the statistical properties of the recurrence intervals ? between successive trading volumes exceeding a certain threshold q. The recurrence interval analysis is carried out for the 20 liquid Chinese stocks covering a period from January 2000 to May 2009, and two Chinese indices from January 2003 to April 2009. Similar to the recurrence interval distribution of the price returns, the tail of the recurrence interval distribution of the trading volumes follows a power-law scaling, and the results are verified by the goodness-of-fit tests using the Kolmogorov-Smirnov (KS) statistic, the weighted KS statistic and the Cramér-von Mises criterion. The measurements of the conditional probability distribution and the detrended fluctuation function show that both short-term and long-term memory effects exist in the recurrence intervals between trading volumes. We further study the relationship between trading volumes and price returns based on the recurrence interval analysis method. It is found that large trading volumes are more likely to occur following large price returns, and the comovement between trading volumes and price returns is more pronounced for large trading volumes. PMID:20866478

  15. Recurrence interval analysis of trading volumes

    NASA Astrophysics Data System (ADS)

    Ren, Fei; Zhou, Wei-Xing

    2010-06-01

    We study the statistical properties of the recurrence intervals ? between successive trading volumes exceeding a certain threshold q . The recurrence interval analysis is carried out for the 20 liquid Chinese stocks covering a period from January 2000 to May 2009, and two Chinese indices from January 2003 to April 2009. Similar to the recurrence interval distribution of the price returns, the tail of the recurrence interval distribution of the trading volumes follows a power-law scaling, and the results are verified by the goodness-of-fit tests using the Kolmogorov-Smirnov (KS) statistic, the weighted KS statistic and the Cramér-von Mises criterion. The measurements of the conditional probability distribution and the detrended fluctuation function show that both short-term and long-term memory effects exist in the recurrence intervals between trading volumes. We further study the relationship between trading volumes and price returns based on the recurrence interval analysis method. It is found that large trading volumes are more likely to occur following large price returns, and the comovement between trading volumes and price returns is more pronounced for large trading volumes.

  16. Combining DOM tree and geometric layout analysis for online medical journal article segmentation

    Microsoft Academic Search

    Jie Zou; Daniel X. Le; George R. Thoma

    2006-01-01

    We describe an HTML web page segmentation algorithm, which is applied to segment online medical journal articles (regular HTML and PDF-Converted-HTML files). The web page content is modeled by a zone tree structure based primarily on the geometric layout of the web page. For a given journal article, a zone tree is generated by combining DOM tree analysis and recursive

  17. Multi-resolution Segmentation and Shape Analysis for Remote Sensing Image Classification

    E-print Network

    Aksoy, Selim

    , agricultural and ecological studies. The usual choice for the level of processing image data has been pixel delineation of agricultural fields [9]. We model spatial information by segmenting images into spatiallyMulti-resolution Segmentation and Shape Analysis for Remote Sensing Image Classification Selim

  18. Analysis of Drosophila Segmentation Network Identifies a JNK Pathway Factor Overexpressed in Kidney Cancer

    Microsoft Academic Search

    Jiang Liu; Murad Ghanim; Lei Xue; Christopher D. Brown; Ivan Iossifov; Cesar Angeletti; Sujun Hua; Nicolas Nègre; Michael Ludwig; Thomas Stricker; Hikmat A. Al-Ahmadie; Maria Tretiakova; Robert L. Camp; Montse Perera-Alberto; David L. Rimm; Tian Xu; Andrey Rzhetsky; Kevin P. White

    2009-01-01

    We constructed a large-scale functional network model in Drosophila melanogaster built around two key transcription factors involved in the process of embryonic segmentation. Analysis of the model allowed the identification of a new role for the ubiquitin E3 ligase complex factor SPOP. In Drosophila, the gene encoding SPOP is a target of segmentation transcription factors. Drosophila SPOP mediates degradation of

  19. Segmenting casino gamblers by motivation: A cluster analysis of Korean gamblers

    Microsoft Academic Search

    Choong-Ki Lee; Yong-Ki Lee; Bo Jason Bernhard; Yoo-Shik Yoon

    2006-01-01

    While past research has explored why people become problem or pathological gamblers, the motivations of the broader gambling population have been largely neglected. This study examines casino gambling motivations for a sample of Korean gamblers. Specifically, this study attempts to segment the casino gambling market using a cluster analysis, and to explore differences between segments with respect to socio-demographic and

  20. Quantitative Analysis of Peristaltic and Segmental Motion In Vivo in the Rat Small Intestine Using Dynamic

    E-print Network

    Brasseur, James G.

    Quantitative Analysis of Peristaltic and Segmental Motion In Vivo in the Rat Small Intestine Using of nutrients that takes place within the small intestine. The normal processes of the small intestine are known been used extensively to study segments of the intestine that have been exteriorized from animals

  1. An Integrated Segmentation and Classification Approach Applied to Multiple Sclerosis Analysis

    E-print Network

    1 An Integrated Segmentation and Classification Approach Applied to Multiple Sclerosis Analysis utility in detecting Multiple Sclerosis lesions in 3D multi-channel MRI data. Our method uses segmentation structures focusing on 3D MRI brain data containing scans of Multiple Sclerosis (MS) patients. Manual

  2. An Integrated Segmentation and Classification Approach Applied to Multiple Sclerosis Analysis

    E-print Network

    An Integrated Segmentation and Classification Approach Applied to Multiple Sclerosis Analysis, and demonstrate its utility in detecting multiple sclerosis lesions in 3D MRI data. Our method uses segmentation structures focusing on 3D MRI brain data containing scans of multiple sclerosis (MS) patients. Research

  3. AUTOMATIC INFERIOR VENA CAVA SEGMENTATION IN CONTRAST-ENHANCED CT VOLUMES

    E-print Network

    Paris-Sud XI, Université de

    anatomical model [1]. In clinical practice, manual segmentation by radiology experts is time Mory, Roberto Ardon, Javier Sanchez-Castro Medisys Research Lab, Philips Healthcare, France Anthony. In clinical diagnosis and surgery planning, IVC segmentation is essential since it strongly impacts both liver

  4. Multivision determination of the volume of human body segments and implementation of a dynamic model

    Microsoft Academic Search

    J. Y Ertaud; X Savatier; W Schmidt; J. M Thomine; F. H Dujardin

    1999-01-01

    Many biomechanical models analyzing human movements require the morphological data of each body segment, such as partial mass inertial characteristics. These data may be evaluated from the three-dimensional (3-D) envelope of these segments. This study was aimed at developing a simple system compatible with routine procedures with which these 3-D envelopes could be measured. Testing was carried out with an

  5. Structured Time Series Analysis for Human Action Segmentation and Recognition.

    PubMed

    Gong, Dian; Medioni, Gérard; Zhao, Xuemei

    2013-12-11

    We address the problem of structure learning of human motion to recognize actions from a continuous monocular motion sequence of an arbitrary person from an arbitrary viewpoint. Human motion sequences are represented by multivariate time series in the joint trajectories space. Under this structured time series framework, we first propose Kernelized Temporal Cut (KTC), an extension of previous works on change-point detection by incorporating Hilbert space embedding of distributions, to handle the nonparametric and high dimensionality issues. Experimental results demonstrate the effectiveness of our approach, which yields realtime segmentation, and produces high action segmentation accuracy. Second, a spatio-temporal manifold framework is proposed to model the latent structure of time series data. Then an efficient spatio-temporal alignment algorithm Dynamic Manifold Warping (DMW) is proposed for time series to calculate motion similarity between action sequences (segments). Furthermore, by combining the temporal segmentation algorithm and the alignment algorithm, online action recognition can be performed by associating a few labeled examples from motion capture data. The results on human motion capture data and 3D depth sensor data demonstrate the effectiveness of the proposed approach in segmenting and recognizing motion sequences, and its ability to handle noisy and partially occluded data, in the transfer learning module. PMID:24344075

  6. Molecular cytogenetic analysis of supernumerary heterochromatic segments in Rumex acetosa.

    PubMed

    Shibata, F; Hizume, M; Kuroki, Y

    2000-04-01

    The dioecious plant Rumex acetosa shows intraspecific karyotype variation, caused by supernumerary heterochromatic segments or DAPI (4',6-diamidino-2 phenylindole)-bands at the ends of the short arms of three pairs of autosomes. A DNA sequence (RAE730) specific to the supernumerary heterochromatic segments was cloned and sequenced. RAE730 was about 730 bp and AT-rich (71% AT-content). Using fluorescence in situ hybridization (FISH), RAE730 was localized in the supernumerary DAPI-positive heterochromatic segments on several mitotic chromosomes and chromocenters in interphase nuclei, but not in the DAPI-bands of Y or B chromosomes. RAE730 was tandemly arranged in the genome, and the copy number varied between plants from 40000 to 304000 copies per 2C, corresponding to the relative amount of supernumerary heterochromatic segments per genome. These results indicate that the karyotype variation caused by the supernumerary heterochromatic segment was generated by amplification or reduction of the tandem repeats of RAE730. PMID:10791829

  7. Fuzzy segmentation for geographic object-based image analysis

    NASA Astrophysics Data System (ADS)

    Lizarazo, Ivan; Elsner, Paul

    2009-09-01

    Image segmentation partitions remote sensing images into image objects before assigning them to categorical land cover classes. Current segmentation methods require users to invest considerable time and effort in the search for meaningful image objects. As an alternative method we propose 'fuzzy' segmentation that offers more flexibility in dealing with remote sensing uncertainty. In the proposed method, original bands are processed using regression techniques to output fuzzy image regions which express degrees of membership to target land cover classes. Contextual properties of fuzzy regions can be measured to indicate potential spectral confusion. A 'defuzzification' process is subsequently conducted to produce the categorical land cover classes. This method was tested using data sets of both high and medium spatial resolution. The results indicate that this approach is able to produce classification with satisfying accuracy and requires very little user interaction.

  8. Segmentation of SBFSEM Volume Data of Neural Tissue by Hierarchical Classification

    Microsoft Academic Search

    Björn Andres; Ullrich Köthe; Moritz Helmstaedter; Winfried Denk; Fred A. Hamprecht

    2008-01-01

    Three-dimensional electron-microscopic image stacks with almost isotropic resolution allow, for the first time, to determine\\u000a the complete connection matrix of parts of the brain. In spite of major advances in staining, correct segmentation of these\\u000a stacks remains challenging, because very few local mistakes can lead to severe global errors. We propose a hierarchical segmentation\\u000a procedure based on statistical learning and

  9. Moving object segmentation by background subtraction and temporal analysis

    Microsoft Academic Search

    Paolo Spagnolo; Tiziana D'orazio; Marco Leo; Arcangelo Distante

    2006-01-01

    In this paper, we address the problem of moving object segmentation using background subtraction. Solving this problem is very important for many applications: visual surveillance of both in outdoor and indoor environments, traffic control, behavior detection during sport activities, and so on. All these applications require as a first step, the detection of moving objects in the observed scene before

  10. Ethical segmentation of consumers in developing countries: a comparative analysis

    Microsoft Academic Search

    Jamal A. Al-Khatib; Angela D'Auria Stanton; Mohammed Y. A. Rawwas

    2005-01-01

    Purpose – The purpose of this study is to segment the consumer Gulf market based on actionable and strategy yielding marketing variables (i.e. ethical orientations, trust, opportunisms and Machiavellianism). Design\\/methodology\\/approach – Consumers from Saudi Arabia, Oman and Kuwait were asked to complete a survey which incorporated scales to measure consumers' ethical beliefs, Machiavellianism, ethical orientation, opportunism, trust, as well as

  11. Volumetric analysis of liver segments in 155 living donors

    Microsoft Academic Search

    Surasak Leelaudomlipi; Yasuhiko Sugawara; Junichi Kaneko; Yuichi Matsui; Takao Ohkubo; Masatoshi Makuuchi

    2002-01-01

    Right-lobe graft has been used most frequently for living donor liver transplantation in adult patients; however, some donors cannot donate their right lobe (according to the Healey and Scroy's terminology) because the remaining residual liver would be too small. A recent study suggested the possibility of right posterior segment graft in these donors. The purpose of this study was to

  12. Computed Tomographic Image Analysis Based on FEM Performance Comparison of Segmentation on Knee Joint Reconstruction

    PubMed Central

    Jang, Seong-Wook; Seo, Young-Jin; Yoo, Yon-Sik

    2014-01-01

    The demand for an accurate and accessible image segmentation to generate 3D models from CT scan data has been increasing as such models are required in many areas of orthopedics. In this paper, to find the optimal image segmentation to create a 3D model of the knee CT data, we compared and validated segmentation algorithms based on both objective comparisons and finite element (FE) analysis. For comparison purposes, we used 1 model reconstructed in accordance with the instructions of a clinical professional and 3 models reconstructed using image processing algorithms (Sobel operator, Laplacian of Gaussian operator, and Canny edge detection). Comparison was performed by inspecting intermodel morphological deviations with the iterative closest point (ICP) algorithm, and FE analysis was performed to examine the effects of the segmentation algorithm on the results of the knee joint movement analysis. PMID:25538950

  13. A Two-Step Segmentation Method for Breast Ultrasound Masses Based on Multi-resolution Analysis.

    PubMed

    Rodrigues, Rafael; Braz, Rui; Pereira, Manuela; Moutinho, José; Pinheiro, Antonio M G

    2015-06-01

    Breast ultrasound images have several attractive properties that make them an interesting tool in breast cancer detection. However, their intrinsic high noise rate and low contrast turn mass detection and segmentation into a challenging task. In this article, a fully automated two-stage breast mass segmentation approach is proposed. In the initial stage, ultrasound images are segmented using support vector machine or discriminant analysis pixel classification with a multiresolution pixel descriptor. The features are extracted using non-linear diffusion, bandpass filtering and scale-variant mean curvature measures. A set of heuristic rules complement the initial segmentation stage, selecting the region of interest in a fully automated manner. In the second segmentation stage, refined segmentation of the area retrieved in the first stage is attempted, using two different techniques. The AdaBoost algorithm uses a descriptor based on scale-variant curvature measures and non-linear diffusion of the original image at lower scales, to improve the spatial accuracy of the ROI. Active contours use the segmentation results from the first stage as initial contours. Results for both proposed segmentation paths were promising, with normalized Dice similarity coefficients of 0.824 for AdaBoost and 0.813 for active contours. Recall rates were 79.6% for AdaBoost and 77.8% for active contours, whereas the precision rate was 89.3% for both methods. PMID:25736608

  14. Combined texture feature analysis of segmentation and classification of benign and malignant tumour CT slices.

    PubMed

    Padma, A; Sukanesh, R

    2013-01-01

    A computer software system is designed for the segmentation and classification of benign from malignant tumour slices in brain computed tomography (CT) images. This paper presents a method to find and select both the dominant run length and co-occurrence texture features of region of interest (ROI) of the tumour region of each slice to be segmented by Fuzzy c means clustering (FCM) and evaluate the performance of support vector machine (SVM)-based classifiers in classifying benign and malignant tumour slices. Two hundred and six tumour confirmed CT slices are considered in this study. A total of 17 texture features are extracted by a feature extraction procedure, and six features are selected using Principal Component Analysis (PCA). This study constructed the SVM-based classifier with the selected features and by comparing the segmentation results with the experienced radiologist labelled ground truth (target). Quantitative analysis between ground truth and segmented tumour is presented in terms of segmentation accuracy, segmentation error and overlap similarity measures such as the Jaccard index. The classification performance of the SVM-based classifier with the same selected features is also evaluated using a 10-fold cross-validation method. The proposed system provides some newly found texture features have an important contribution in classifying benign and malignant tumour slices efficiently and accurately with less computational time. The experimental results showed that the proposed system is able to achieve the highest segmentation and classification accuracy effectiveness as measured by jaccard index and sensitivity and specificity. PMID:23094909

  15. Reliable Cell Segmentation Based on Spectral Phasor Analysis of Hyperspectral Stimulated Raman Scattering Imaging Data

    E-print Network

    Xie, Xiaoliang Sunney

    Reliable Cell Segmentation Based on Spectral Phasor Analysis of Hyperspectral Stimulated Raman information on the cell composition. Here, we demonstrate a spectral phasor analysis method that allows fast selection of a few wavenumbers, spectral phasor analysis provides a robust solution to label-free single

  16. Automated vessel segmentation using cross-correlation and pooled covariance matrix analysis.

    PubMed

    Du, Jiang; Karimi, Afshin; Wu, Yijing; Korosec, Frank R; Grist, Thomas M; Mistretta, Charles A

    2011-04-01

    Time-resolved contrast-enhanced magnetic resonance angiography (CE-MRA) provides contrast dynamics in the vasculature and allows vessel segmentation based on temporal correlation analysis. Here we present an automated vessel segmentation algorithm including automated generation of regions of interest (ROIs), cross-correlation and pooled sample covariance matrix analysis. The dynamic images are divided into multiple equal-sized regions. In each region, ROIs for artery, vein and background are generated using an iterative thresholding algorithm based on the contrast arrival time map and contrast enhancement map. Region-specific multi-feature cross-correlation analysis and pooled covariance matrix analysis are performed to calculate the Mahalanobis distances (MDs), which are used to automatically separate arteries from veins. This segmentation algorithm is applied to a dual-phase dynamic imaging acquisition scheme where low-resolution time-resolved images are acquired during the dynamic phase followed by high-frequency data acquisition at the steady-state phase. The segmented low-resolution arterial and venous images are then combined with the high-frequency data in k-space and inverse Fourier transformed to form the final segmented arterial and venous images. Results from volunteer and patient studies demonstrate the advantages of this automated vessel segmentation and dual phase data acquisition technique. PMID:21074345

  17. Analysis and testing of a soft actuation system for segmented reflector articulation and isolation

    NASA Technical Reports Server (NTRS)

    Jandura, Louise; Agronin, Michael L.

    1991-01-01

    Segmented reflectors have been proposed for space-based applications such as optical communication and large-diameter telescopes. An actuation system for mirrors in a space-based segmented mirror array has been developed as part of the National Aeronautics and Space Administration-sponsored Precision Segmented Reflector program. The actuation system, called the Articulated Panel Module (APM), articulates a mirror panel in 3 degrees of freedom in the submicron regime, isolates the panel from structural motion, and simplifies space assembly of the mirrors to the reflector backup truss. A breadboard of the APM has been built and is described. Three-axis modeling, analysis, and testing of the breadboard is discussed.

  18. Applying wavelet analysis to speech segmentation and classification

    NASA Astrophysics Data System (ADS)

    Tan, Beng T.; Lang, Robert; Schroder, Heiko; Spray, Andrew; Dermody, Phillip

    1994-03-01

    We propose the design of a hearing aid based on the wavelet transform. The fast wavelet transform is used to decompose speech into different frequency components. This paper presents the difficulties in the use of wavelet transforms for speech processing and shows how the careful selection of wavelet coefficients can enable the four major categories of speech - voiced speech, plosives, fricatives, and silence - to be identified. With knowledge of these four categories, it is shown how speech can be easily and effectively segmented.

  19. Automatic Segmentation of Scanned Human Body Using Curve Skeleton Analysis

    Microsoft Academic Search

    Christian Lovato; Umberto Castellani; Andrea Giachetti

    2009-01-01

    In this paper we present a method for the automatic processing of scanned human body data consisting of an algorithm for the\\u000a extraction of curve skeletons of the 3D models acquired and a procedure for the automatic segmentation of skeleton branches.\\u000a Models used in our experiments are obtained with a whole-body scanner based on structured light (Breuckmann bodySCAN, owned\\u000a by

  20. Sport divers and underwater parks: a market segmentation analysis 

    E-print Network

    Matheusik, Mick Eric

    1983-01-01

    or reserves in Ontario and British Columbia is of value to park planners and managers who are contemplating the long range development of underwater park systems in both provinces, to tourism planners, and to private entrepreneurs who are promoting... these experiences. Understanding the different market segments of sport divers who use underwater parks in Ontario and British Columbia is of value to park planners and managers who are contemplating the development of long range underwater park systems in both...

  1. Automatic segmentation of the colon

    NASA Astrophysics Data System (ADS)

    Wyatt, Christopher L.; Ge, Yaorong; Vining, David J.

    1999-05-01

    Virtual colonoscopy is a minimally invasive technique that enables detection of colorectal polyps and cancer. Normally, a patient's bowel is prepared with colonic lavage and gas insufflation prior to computed tomography (CT) scanning. An important step for 3D analysis of the image volume is segmentation of the colon. The high-contrast gas/tissue interface that exists in the colon lumen makes segmentation of the majority of the colon relatively easy; however, two factors inhibit automatic segmentation of the entire colon. First, the colon is not the only gas-filled organ in the data volume: lungs, small bowel, and stomach also meet this criteria. User-defined seed points placed in the colon lumen have previously been required to spatially isolate only the colon. Second, portions of the colon lumen may be obstructed by peristalsis, large masses, and/or residual feces. These complicating factors require increased user interaction during the segmentation process to isolate additional colon segments. To automate the segmentation of the colon, we have developed a method to locate seed points and segment the gas-filled lumen with no user supervision. We have also developed an automated approach to improve lumen segmentation by digitally removing residual contrast-enhanced fluid resulting from a new bowel preparation that liquefies and opacifies any residual feces.

  2. Analysis of radially cracked ring segments subject to forces and couples

    NASA Technical Reports Server (NTRS)

    Gross, B.; Strawley, J. E.

    1975-01-01

    Results of planar boundary collocation analysis are given for ring segment (C shaped) specimens with radial cracks, subjected to combined forces and couples. Mode I stress intensity factors and crack mouth opening displacements were determined for ratios of outer to inner radius in the range 1.1 to 2.5, and ratios of crack length to segment width in the range 0.1 to 0.8.

  3. REMOVAL OF ABDOMINAL WALL FOR 3D VISUALIZATION AND SEGMENTATION OF ORGANS IN CT VOLUME

    E-print Network

    Leow, Wee Kheng

    images are important in medical image processing for applications such as diagnosis, treatment image processing for applications such as diagnosis, treatment and surgical plan- ning. However. RELATED WORK General deformable segmentation algorithms such as snake [1] and level set [2, 3

  4. Automated Segmentation of Cerebellum Using Brain Mask and Partial Volume Estimation Map

    PubMed Central

    Lee, Dong-Kyun; Yoon, Uicheul; Kwak, Kichang; Lee, Jong-Min

    2015-01-01

    While segmentation of the cerebellum is an indispensable step in many studies, its contrast is not clear because of the adjacent cerebrospinal fluid, meninges, and cerebra peduncle. Thus, various cerebellar segmentation methods, such as a deformable model or a template-based algorithm might exhibit incorrect segmentation of the venous sinuses and the cerebellar peduncle. In this study, we propose a fully automated procedure combining cerebellar tissue classification, a template-based approach, and morphological operations sequentially. The cerebellar region was defined approximately by removing the cerebral region from the brain mask. Then, the noncerebellar region was trimmed using a morphological operator and the brain-stem atlas was aligned to the individual brain to define the brain-stem area. The proposed method was validated with the well-known FreeSurfer and ITK-SNAP packages using the dice similarity index and recall and precision scores. As a result, the proposed method was significantly better than the other methods for the dice similarity index (0.93, FreeSurfer: 0.92, ITK-SNAP: 0.87) and precision (0.95, FreeSurfer: 0.90, ITK-SNAP: 0.93). Therefore, it could be said that the proposed method yielded a robust and accurate segmentation result. Moreover, additional postprocessing with the brain-stem atlas could improve its result.

  5. Fuzzy hidden Markov chains segmentation for volume determination and quantitation in PET

    Microsoft Academic Search

    Accurate volume of interest (VOI) estimation in PET is crucial in different oncology applications such as response to therapy evaluation and radiotherapy treatment planning. The objective of our study was to evaluate the performance of the proposed algorithm for automatic lesion volume delineation; namely the fuzzy hidden Markov chains (FHMC), with that of current state of the art in clinical

  6. Stream Volume Segmentation of Grid-Less Flow Harald Obermaier1

    E-print Network

    Hering-Bertram, Martin

    temperature through a cylindrical mixing tube (see Fig. 1). Six twisted blades located sequentially inside of volumes taking consistent paths through a mixing tube with six partitioning blades. Slicing these volumes extraction. Fig. 1. Cylindrical mixing tube with six blades. #12;In the present work we contribute a novel

  7. Automated abdominal lymph node segmentation based on RST analysis and SVM

    NASA Astrophysics Data System (ADS)

    Nimura, Yukitaka; Hayashi, Yuichiro; Kitasaka, Takayuki; Furukawa, Kazuhiro; Misawa, Kazunari; Mori, Kensaku

    2014-03-01

    This paper describes a segmentation method for abdominal lymph node (LN) using radial structure tensor analysis (RST) and support vector machine. LN analysis is one of crucial parts of lymphadenectomy, which is a surgical procedure to remove one or more LNs in order to evaluate them for the presence of cancer. Several works for automated LN detection and segmentation have been proposed. However, there are a lot of false positives (FPs). The proposed method consists of LN candidate segmentation and FP reduction. LN candidates are extracted using RST analysis in each voxel of CT scan. RST analysis can discriminate between difference local intensity structures without influence of surrounding structures. In FP reduction process, we eliminate FPs using support vector machine with shape and intensity information of the LN candidates. The experimental result reveals that the sensitivity of the proposed method was 82.0 % with 21.6 FPs/case.

  8. Extensions to analysis of ignition transients of segmented rocket motors

    NASA Technical Reports Server (NTRS)

    Caveny, L. H.

    1978-01-01

    The analytical procedures described in NASA CR-150162 were extended for the purpose of analyzing the data from the first static test of the Solid Rocket Booster for the Space Shuttle. The component of thrust associated with the rapid changes in the internal flow field was calculated. This dynamic thrust component was shown to be prominent during flame spreading. An approach was implemented to account for the close coupling between the igniter and head end segment of the booster. The tips of the star points were ignited first, followed by radial and longitudinal flame spreading.

  9. A robust and fast line segment detector based on top-down smaller eigenvalue analysis

    NASA Astrophysics Data System (ADS)

    Liu, Dong; Wang, Yongtao; Tang, Zhi; Lu, Xiaoqing

    2014-01-01

    In this paper, we propose a robust and fast line segment detector, which achieves accurate results with a controlled number of false detections and requires no parameter tuning. It consists of three steps: first, we propose a novel edge point chaining method to extract Canny edge segments (i.e., contiguous chains of Canny edge points) from the input image; second, we propose a top-down scheme based on smaller eigenvalue analysis to extract line segments within each obtained edge segment; third, we employ Desolneux et al.'s method to reject false detections. Experiments demonstrate that it is very efficient and more robust than two state of the art methods—LSD and EDLines.

  10. A marked point process of rectangles and segments for automatic analysis of Digital Elevation Models.

    E-print Network

    Paris-Sud XI, Université de

    1 A marked point process of rectangles and segments for automatic analysis of Digital Elevation annealing algorithm. The proposed model is applied to the analysis of Digital Elevation Models (DEMs Elevation Models, land register, building detection, MCMC, RJMCMC, simulated annealing. I. INTRODUCTION A

  11. UNSUPERVISED MINING OF AUDIOVISUALLY CONSISTENT SEGMENTS IN VIDEOS WITH APPLICATION TO STRUCTURE ANALYSIS

    E-print Network

    Paris-Sud XI, Université de

    video structure analysis, using simple heuristics on occurrence patterns of the events discoveredUNSUPERVISED MINING OF AUDIOVISUALLY CONSISTENT SEGMENTS IN VIDEOS WITH APPLICATION TO STRUCTURE ANALYSIS Mathieu Ben INRIA Rennes 35042 Rennes Cedex, France mathieu.ben@inria.fr Guillaume Gravier IRISA

  12. A phonetically labeled acoustic segment (PLAS) approach to speech analysis-synthesis

    Microsoft Academic Search

    Frank K. Soong

    1989-01-01

    A phonetically labeled acoustic segment (PLAS) approach is proposed for speech analysis-synthesis. The goal is to develop a unified framework for general speech processing by means of a bidirectional context-constrained mapping between a phonetic space and an acoustic space. The PLAS analysis module is a continuous phone (phoneme) recognizer, while the PLAS synthesis module is a phonetically organized acoustic database.

  13. Mathematical Analysis of Space Radiator Segmenting for Increased Reliability and Reduced Mass

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.

    2001-01-01

    Spacecraft for long duration deep space missions will need to be designed to survive micrometeoroid bombardment of their surfaces some of which may actually be punctured. To avoid loss of the entire mission the damage due to such punctures must be limited to small, localized areas. This is especially true for power system radiators, which necessarily feature large surface areas to reject heat at relatively low temperature to the space environment by thermal radiation. It may be intuitively obvious that if a space radiator is composed of a large number of independently operating segments, such as heat pipes, a random micrometeoroid puncture will result only in the loss of the punctured segment, and not the entire radiator. Due to the redundancy achieved by independently operating segments, the wall thickness and consequently the weight of such segments can be drastically reduced. Probability theory is used to estimate the magnitude of such weight reductions as the number of segments is increased. An analysis of relevant parameter values required for minimum mass segmented radiators is also included.

  14. Combining multiset resolution and segmentation for hyperspectral image analysis of biological tissues.

    PubMed

    Piqueras, S; Krafft, C; Beleites, C; Egodage, K; von Eggeling, F; Guntinas-Lichius, O; Popp, J; Tauler, R; de Juan, A

    2015-06-30

    Hyperspectral images can provide useful biochemical information about tissue samples. Often, Fourier transform infrared (FTIR) images have been used to distinguish different tissue elements and changes caused by pathological causes. The spectral variation between tissue types and pathological states is very small and multivariate analysis methods are required to describe adequately these subtle changes. In this work, a strategy combining multivariate curve resolution-alternating least squares (MCR-ALS), a resolution (unmixing) method, which recovers distribution maps and pure spectra of image constituents, and K-means clustering, a segmentation method, which identifies groups of similar pixels in an image, is used to provide efficient information on tissue samples. First, multiset MCR-ALS analysis is performed on the set of images related to a particular pathology status to provide basic spectral signatures and distribution maps of the biological contributions needed to describe the tissues. Later on, multiset segmentation analysis is applied to the obtained MCR scores (concentration profiles), used as compressed initial information for segmentation purposes. The multiset idea is transferred to perform image segmentation of different tissue samples. Doing so, a difference can be made between clusters associated with relevant biological parts common to all images, linked to general trends of the type of samples analyzed, and sample-specific clusters, that reflect the natural biological sample-to-sample variability. The last step consists of performing separate multiset MCR-ALS analyses on the pixels of each of the relevant segmentation clusters for the pathology studied to obtain a finer description of the related tissue parts. The potential of the strategy combining multiset resolution on complete images, multiset segmentation and multiset local resolution analysis will be shown on a study focused on FTIR images of tissue sections recorded on inflamed and non-inflamed palatine tonsils. PMID:26041517

  15. Scientific and clinical evidence for the use of fetal ECG ST segment analysis (STAN).

    PubMed

    Steer, Philip J; Hvidman, Lone Egly

    2014-06-01

    Fetal electrocardiogram waveform analysis has been studied for many decades, but it is only in the last 20 years that computerization has made real-time analysis practical for clinical use. Changes in the ST segment have been shown to correlate with fetal condition, in particular with acid-base status. Meta-analysis of randomized trials (five in total, four using the computerized system) has shown that use of computerized ST segment analysis (STAN) reduces the need for fetal blood sampling by about 40%. However, although there are trends to lower rates of low Apgar scores and acidosis, the differences are not statistically significant. There is no effect on cesarean section rates. Disadvantages include the need for amniotic membranes to be ruptured so that a fetal scalp electrode can be applied, and the need for STAN values to be interpreted in conjunction with detailed fetal heart rate pattern analysis. PMID:24597897

  16. Tie-Zone Watershed, Bottlenecks and Segmentation Robustness Analysis Romaric Audigier, Roberto de Alencar Lotufo

    E-print Network

    Cord, Aurélien

    Tie-Zone Watershed, Bottlenecks and Segmentation Robustness Analysis Romaric Audigier, Roberto de.dca.fee.unicamp.br/lotufo Abstract In a recent paper [1], a new type of watershed (WS) transform was introduced: the tie-zone watershed (TZWS). This region-based watershed transform does not depend on arbitrary implementation

  17. Unsupervised Segmentation Using Gabor Wavelets and Statistical Features in LIDAR Data Analysis

    E-print Network

    Reading, University of

    parameters. 1. Introduction Airborne laser scanned LIDAR data have become popular in remote sensing, land scanned LIDAR data to generate their Gabor wavelet representation, which is then grouped into smallUnsupervised Segmentation Using Gabor Wavelets and Statistical Features in LIDAR Data Analysis Hong

  18. SHAPE-CONSTRAINED SEGMENTATION APPROACH FOR ARCTIC MULTIYEAR SEA ICE FLOE ANALYSIS

    E-print Network

    Boyer, Edmond

    SHAPE-CONSTRAINED SEGMENTATION APPROACH FOR ARCTIC MULTIYEAR SEA ICE FLOE ANALYSIS Yuliya Tarabalka Research Association, MD, USA. e-mail: yuliya.tarabalka@inria.fr ABSTRACT The melting of sea ice, it is important to investigate how rapidly sea ice floes melt. For this purpose, a new TempoSeg method

  19. Loads analysis and testing of flight configuration solid rocket motor outer boot ring segments

    NASA Technical Reports Server (NTRS)

    Ahmed, Rafiq

    1990-01-01

    The loads testing on in-house-fabricated flight configuration Solid Rocket Motor (SRM) outer boot ring segments. The tests determined the bending strength and bending stiffness of these beams and showed that they compared well with the hand analysis. The bending stiffness test results compared very well with the finite element data.

  20. Analysis of horizontally curved post-tensioned segmental concrete box girder bridges

    Microsoft Academic Search

    Rafael Manuel Rojas

    1993-01-01

    This report presents the background and details of a numerical procedure developed specifically for the longitudinal analysis of curved segmentally erected prestressed concrete box girder bridges. It is based on a skew ended thin-wall beam element including the modes of warping and distorsion of the cross section. The cross section must consist of a single cell, may have overhangs, and

  1. Dense motion analysis and segmentation of ultrasound images

    NASA Astrophysics Data System (ADS)

    Yokoyama, Ryo; Aoki, Kota; Nagahashi, Hiroshi

    2015-03-01

    We propose a dense motion analysis method for ultrasound images. A motion analysis is implemented by tracking a lot of lattice points. In this paper, two novel processings are introduced to perform the motion analysis. One is the tracking of lattice points based on an optical flow algorithm in a framework of multiple spring-models. The other is the detection of lattice points based on texture information with confidence value, and its result corrects the tracking errors. We evaluated our method using a sequence of artificial ultrasound images up to 5 minutes. The average and maximum errors of our proposed method have achieved the best performance in the conventional methods.

  2. Music video shot segmentation using independent component analysis and keyframe extraction based on image complexity

    NASA Astrophysics Data System (ADS)

    Li, Wei; Chen, Ting; Zhang, Wenjun; Shi, Yunyu; Li, Jun

    2012-04-01

    In recent years, Music video data is increasing at an astonishing speed. Shot segmentation and keyframe extraction constitute a fundamental unit in organizing, indexing, retrieving video content. In this paper a unified framework is proposed to detect the shot boundaries and extract the keyframe of a shot. Music video is first segmented to shots by illumination-invariant chromaticity histogram in independent component (IC) analysis feature space .Then we presents a new metric, image complexity, to extract keyframe in a shot which is computed by ICs. Experimental results show the framework is effective and has a good performance.

  3. Concerted Assembly and Cloning of Multiple DNA Segments Using In Vitro Site-Specific Recombination: Functional Analysis of Multi-Segment Expression Clones

    PubMed Central

    Cheo, David L.; Titus, Steven A.; Byrd, Devon R.N.; Hartley, James L.; Temple, Gary F.; Brasch, Michael A.

    2004-01-01

    The ability to clone and manipulate DNA segments is central to molecular methods that enable expression, screening, and functional characterization of genes, proteins, and regulatory elements. We previously described the development of a novel technology that utilizes in vitro site-specific recombination to provide a robust and flexible platform for high-throughput cloning and transfer of DNA segments. By using an expanded repertoire of recombination sites with unique specificities, we have extended the technology to enable the high-efficiency in vitro assembly and concerted cloning of multiple DNA segments into a vector backbone in a predefined order, orientation, and reading frame. The efficiency and flexibility of this approach enables collections of functional elements to be generated and mixed in a combinatorial fashion for the parallel assembly of numerous multi-segment constructs. The assembled constructs can be further manipulated by directing exchange of defined segments with alternate DNA segments. In this report, we demonstrate feasibility of the technology and application to the generation of fusion proteins, the linkage of promoters to genes, and the assembly of multiple protein domains. The technology has broad implications for cell and protein engineering, the expression of multidomain proteins, and gene function analysis. PMID:15489333

  4. [Remote sensing image segmentation based on a multiresolution region granularity analysis method].

    PubMed

    Zheng, Chen; Sun, Ding-Qian; Chen, Xiao-Hui

    2013-07-01

    Remote sensing image has abundant granularity information. In order to utilize this information, a multiresolution region granularity analysis method is proposed in the present paper for image segmentation The proposed method firstly uses the mean shift to obtain the initial oversegmented regions at each resolution of the image, and then extracts the granularity information based on the region size and the region context, the Markov random field is employed to provide the final segmentation result by modeling the spectrum information and the granularity information. The SPOT5 remote sensing images of Pingshuo and the aerial image of Taizhou were tested to evaluate the proposed method. Compared with other spectrum-based methods, our method shows a better performance and results improved the segmentation accuracy. PMID:24059200

  5. Mimicking human expert interpretation of remotely sensed raster imagery by using a novel segmentation analysis within ArcGIS

    NASA Astrophysics Data System (ADS)

    Le Bas, Tim; Scarth, Anthony; Bunting, Peter

    2015-04-01

    Traditional computer based methods for the interpretation of remotely sensed imagery use each pixel individually or the average of a small window of pixels to calculate a class or thematic value, which provides an interpretation. However when a human expert interprets imagery, the human eye is excellent at finding coherent and homogenous areas and edge features. It may therefore be advantageous for computer analysis to mimic human interpretation. A new toolbox for ArcGIS 10.x will be presented that segments the data layers into a set of polygons. Each polygon is defined by a K-means clustering and region growing algorithm, thus finding areas, their edges and any lineations in the imagery. Attached to each polygon are the characteristics of the imagery such as mean and standard deviation of the pixel values, within the polygon. The segmentation of imagery into a jigsaw of polygons also has the advantage that the human interpreter does not need to spend hours digitising the boundaries. The segmentation process has been taken from the RSGIS library of analysis and classification routines (Bunting et al., 2014). These routines are freeware and have been modified to be available in the ArcToolbox under the Windows (v7) operating system. Input to the segmentation process is a multi-layered raster image, for example; a Landsat image, or a set of raster datasets made up from derivatives of topography. The size and number of polygons are set by the user and are dependent on the imagery used. Examples will be presented of data from the marine environment utilising bathymetric depth, slope, rugosity and backscatter from a multibeam system. Meaningful classification of the polygons using their numerical characteristics is the next goal. Object based image analysis (OBIA) should help this workflow. Fully calibrated imagery systems will allow numerical classification to be translated into more readily understandable terms. Peter Bunting, Daniel Clewley, Richard M. Lucas and Sam Gillingham. 2014. The Remote Sensing and GIS Software Library (RSGISLib), Computers & Geosciences. Volume 62, Pages 216-226 http://dx.doi.org/10.1016/j.cageo.2013.08.007.

  6. Comparison of Acute and Chronic Traumatic Brain Injury Using Semi-Automatic Multimodal Segmentation of MR Volumes

    PubMed Central

    Chambers, Micah C.; Alger, Jeffry R.; Filippou, Maria; Prastawa, Marcel W.; Wang, Bo; Hovda, David A.; Gerig, Guido; Toga, Arthur W.; Kikinis, Ron; Vespa, Paul M.; Van Horn, John D.

    2011-01-01

    Abstract Although neuroimaging is essential for prompt and proper management of traumatic brain injury (TBI), there is a regrettable and acute lack of robust methods for the visualization and assessment of TBI pathophysiology, especially for of the purpose of improving clinical outcome metrics. Until now, the application of automatic segmentation algorithms to TBI in a clinical setting has remained an elusive goal because existing methods have, for the most part, been insufficiently robust to faithfully capture TBI-related changes in brain anatomy. This article introduces and illustrates the combined use of multimodal TBI segmentation and time point comparison using 3D Slicer, a widely-used software environment whose TBI data processing solutions are openly available. For three representative TBI cases, semi-automatic tissue classification and 3D model generation are performed to perform intra-patient time point comparison of TBI using multimodal volumetrics and clinical atrophy measures. Identification and quantitative assessment of extra- and intra-cortical bleeding, lesions, edema, and diffuse axonal injury are demonstrated. The proposed tools allow cross-correlation of multimodal metrics from structural imaging (e.g., structural volume, atrophy measurements) with clinical outcome variables and other potential factors predictive of recovery. In addition, the workflows described are suitable for TBI clinical practice and patient monitoring, particularly for assessing damage extent and for the measurement of neuroanatomical change over time. With knowledge of general location, extent, and degree of change, such metrics can be associated with clinical measures and subsequently used to suggest viable treatment options. PMID:21787171

  7. Image segmentation and analysis via multiscale gradient watershed hierarchies

    Microsoft Academic Search

    John M. Gauch

    1999-01-01

    Multiscale image analysis has been used successfully in a number of applications to classify image features according to their relative scales. As a consequence, much has been learned about the scale-space behavior of intensity extrema, edges, intensity ridges, and grey-level blobs. We investigate the multiscale behavior of gradient watershed regions. These regions are defined in terms of the gradient properties

  8. Segmented Principal Component Analysis for Parallel Compression of Hyperspectral Imagery

    Microsoft Academic Search

    Qian Du; Wei Zhu; He Yang; James E. Fowler

    2009-01-01

    Principal component analysis (PCA) is widely used for spectral decorrelation in the JPEG2000 compression of hyperspectral imagery. However, due to the data-dependent nature of principal components, the principal component transform matrix is stored in the JPEG2000 bitstream, constituting an overhead that is often negligible if the spatial size of the image is large. However, in parallel compression in which the

  9. Segmentation of X-ray computed tomography images of porous materials: A crucial step for characterization and quantitative analysis of pore structures

    NASA Astrophysics Data System (ADS)

    Iassonov, Pavel; Gebrenegus, Thomas; Tuller, Markus

    2009-09-01

    Nondestructive imaging methods such as X-ray computed tomography (CT) yield high-resolution, three-dimensional representations of pore space and fluid distribution within porous materials. Steadily increasing computational capabilities and easier access to X-ray CT facilities have contributed to a recent surge in microporous media research with objectives ranging from theoretical aspects of fluid and interfacial dynamics at the pore scale to practical applications such as dense nonaqueous phase liquid transport and dissolution. In recent years, significant efforts and resources have been devoted to improve CT technology, microscale analysis, and fluid dynamics simulations. However, the development of adequate image segmentation methods for conversion of gray scale CT volumes into a discrete form that permits quantitative characterization of pore space features and subsequent modeling of liquid distribution and flow processes seems to lag. In this paper we investigated the applicability of various thresholding and locally adaptive segmentation techniques for industrial and synchrotron X-ray CT images of natural and artificial porous media. A comparison between directly measured and image-derived porosities clearly demonstrates that the application of different segmentation methods as well as associated operator biases yield vastly differing results. This illustrates the importance of the segmentation step for quantitative pore space analysis and fluid dynamics modeling. Only a few of the tested methods showed promise for both industrial and synchrotron tomography. Utilization of local image information such as spatial correlation as well as the application of locally adaptive techniques yielded significantly better results.

  10. Image Segmentation Using Artificial Neural Network and Genetic Algorithm: A Comparative Analysis

    Microsoft Academic Search

    S. U. Indira; A. C. Ramesh

    2011-01-01

    Image segmentation is an important step in image processing. Most of the segmentation methods are parametric and the results of segmentation depend on the correctness of the estimated parameters. In case of supervised segmentation, a priori knowledge is needed for successful segmentation. So, nonparametric and unsupervised segmentation method is used when a priori information is not available. Kohonen's Self Organizing

  11. Tracking and data acquisition system for the 1990's. Volume 5: TDAS ground segment architecture and operations concept

    NASA Technical Reports Server (NTRS)

    Daly, R.

    1983-01-01

    Tracking and data acquisition system (TDAS) ground segment and operational requirements, TDAS RF terminal configurations, TDAS ground segment elements, the TDAS network, and the TDAS ground terminal hardware are discussed.

  12. Effects of the volume and temperature on the global and segmental dynamics in poly(propylene glycol) and 1,4-polyisoprene

    NASA Astrophysics Data System (ADS)

    Roland, C. M.; Paluch, M.; Casalini, R.

    2004-12-01

    Published dielectric relaxation measurements on polypropylene glycol and 1,4-polyisoprene are analyzed to determine the relative effect that thermal energy and volume have on the temperature dependence of the normal mode relaxation times, and compare this to their effect on the temperature dependence of the local segmental relaxation times. We find that for both polymers at temperatures well above Tg, both relaxation modes are governed more by thermal energy than by volume, although the latter's contribution is not negligible. Such a result is consistent with an assumption underlying models for polymer viscoelasticity, such as the Rouse and tube models, that the friction coefficient governing motions over large length scales can be identified with the local segmental friction coefficient. We also show that relaxation data for both the segmental and the normal mode superimpose, when expressed as a function of the product of the temperature and the volume, the latter raised to a power. This scaling form arises from an inverse power form for the intermolecular potential. The value of the exponent on the volume for these two polymers indicates a relatively "soft" potential.

  13. Segmentation of multiple sclerosis lesions in intensity corrected multispectral MRI

    Microsoft Academic Search

    B. Johnston; M. S. Atkins; B. Mackiewich; M. Anderson

    1996-01-01

    To segment brain tissues in magnetic resonance images of the brain, the authors have implemented a stochastic relaxation method which utilizes partial volume analysis for every brain voxel, and operates on fully three-dimensional (3-D) data. However, there are still problems with automatically or semi-automatically segmenting thick magnetic resonance (MR) slices, particularly when trying to segment the small lesions present in

  14. Automated iterative neutrosophic lung segmentation for image analysis in thoracic computed tomography

    PubMed Central

    Guo, Yanhui; Zhou, Chuan; Chan, Heang-Ping; Chughtai, Aamer; Wei, Jun; Hadjiiski, Lubomir M.; Kazerooni, Ella A.

    2013-01-01

    Purpose: Lung segmentation is a fundamental step in many image analysis applications for lung diseases and abnormalities in thoracic computed tomography (CT). The authors have previously developed a lung segmentation method based on expectation-maximization (EM) analysis and morphological operations (EMM) for our computer-aided detection (CAD) system for pulmonary embolism (PE) in CT pulmonary angiography (CTPA). However, due to the large variations in pathology that may be present in thoracic CT images, it is difficult to extract the lung regions accurately, especially when the lung parenchyma contains extensive lung diseases. The purpose of this study is to develop a new method that can provide accurate lung segmentation, including those affected by lung diseases. Methods: An iterative neutrosophic lung segmentation (INLS) method was developed to improve the EMM segmentation utilizing the anatomic features of the ribs and lungs. The initial lung regions (ILRs) were extracted using our previously developed EMM method, in which the ribs were extracted using 3D hierarchical EM segmentation and the ribcage was constructed using morphological operations. Based on the anatomic features of ribs and lungs, the initial EMM segmentation was refined using INLS to obtain the final lung regions. In the INLS method, the anatomic features were mapped into a neutrosophic domain, and the neutrosophic operation was performed iteratively to refine the ILRs. With IRB approval, 5 and 58 CTPA scans were collected retrospectively and used as training and test sets, of which 2 and 34 cases had lung diseases, respectively. The lung regions manually outlined by an experienced thoracic radiologist were used as reference standard for performance evaluation of the automated lung segmentation. The percentage overlap area (POA), the Hausdorff distance (Hdist), and the average distance (AvgDist) of the lung boundaries relative to the reference standard were used as performance metrics. Results: The proposed method achieved larger POAs and smaller distance errors than the EMM method. For the 58 test cases, the average POA, Hdist, and AvgDist were improved from 85.4 ± 18.4%, 22.6 ± 29.4 mm, and 3.5 ± 5.4 mm using EMM to 91.2 ± 6.7%, 16.0 ± 11.3 mm, and 2.5 ± 1.0 mm using INLS, respectively. The improvements were statistically significant (p < 0.05). To evaluate the accuracy of the INLS method in the identification of the lung boundaries affected by lung diseases, the authors separately analyzed the performance of the proposed method on the cases with versus without the lung diseases. The results showed that the cases without lung diseases were segmented more accurately than the cases with lung diseases by both the EMM and the INLS methods, but the INLS method achieved better performance than the EMM method in both cases. Conclusions: The new INLS method utilizing the anatomic features of the rib and lung significantly improved the accuracy of lung segmentation, especially for the cases affected by lung diseases. Improvement in lung segmentation will facilitate many image analysis tasks and CAD applications for lung diseases and abnormalities in thoracic CT, including automated PE detection. PMID:23927326

  15. Model-Based Segmentation of Cortical Regions of Interest for Multi-subject Analysis of fMRI Data

    Microsoft Academic Search

    Karin Engel; Andre Brechmann; Klaus Toennies

    2008-01-01

    The high inter-subject variability of human neuroanatomy complicates the analysis of functional imaging data across subjects. We propose a method for the correct segmentation of cortical regions of in- terest based on the cortical surface. First results on the segmentation of Heschl's gyrus indicate the capability of our approach for correct compar- ison of functional activations in relation to individual

  16. Pulse shape analysis in segmented detectors as a technique for background reduction in Ge double-beta decay experiments

    Microsoft Academic Search

    S. R. Elliott; V. M. Gehman; K. Kazkaz; D.-M. Mei; A. R. Young

    2006-01-01

    The need to understand and reject backgrounds in Ge-diode detector double-beta decay experiments has given rise to the development of pulse shape analysis in such detectors to discern single-site energy deposits from multiple-site deposits. Here, we extend this analysis to segmented Ge detectors to study the effectiveness of combining segmentation with pulse shape analysis to identify the multiplicity of the

  17. Pulse shape analysis in segmented detectors as a technique for background reduction in Ge double-beta decay experiments

    E-print Network

    Elliott, S R; Kazkaz, K; Mei, D M; Young, A R

    2006-01-01

    The need to understand and reject backgrounds in Ge-diode detector double-beta decay experiments has given rise to the development of pulse shape analysis in such detectors to discern single-site energy deposits from multiple-site deposits. Here, we extend this analysis to segmented Ge detectors to study the effectiveness of combining segmentation with pulse shape analysis to identify the multiplicity of the energy deposits.

  18. Pulse shape analysis in segmented detectors as a technique for background reduction in Ge double-beta decay experiments

    NASA Astrophysics Data System (ADS)

    Elliott, S. R.; Gehman, V. M.; Kazkaz, K.; Mei, D.-M.; Young, A. R.

    2006-03-01

    The need to understand and reject backgrounds in Ge-diode detector double-beta decay experiments has given rise to the development of pulse shape analysis in such detectors to discern single-site energy deposits from multiple-site deposits. Here, we extend this analysis to segmented Ge detectors to study the effectiveness of combining segmentation with pulse shape analysis to identify the multiplicity of the energy deposits.

  19. Pulse shape analysis in segmented detectors as a technique for background reduction in Ge double-beta decay experiments

    E-print Network

    S. R. Elliott; V. M. Gehman; K. Kazkaz; D-M. Mei; A. R. Young

    2005-09-20

    The need to understand and reject backgrounds in Ge-diode detector double-beta decay experiments has given rise to the development of pulse shape analysis in such detectors to discern single-site energy deposits from multiple-site deposits. Here, we extend this analysis to segmented Ge detectors to study the effectiveness of combining segmentation with pulse shape analysis to identify the multiplicity of the energy deposits.

  20. Automated segmentation of muscle and adipose tissue on CT images for human body composition analysis

    NASA Astrophysics Data System (ADS)

    Chung, Howard; Cobzas, Dana; Birdsell, Laura; Lieffers, Jessica; Baracos, Vickie

    2009-02-01

    The ability to compute body composition in cancer patients lends itself to determining the specific clinical outcomes associated with fat and lean tissue stores. For example, a wasting syndrome of advanced disease associates with shortened survival. Moreover, certain tissue compartments represent sites for drug distribution and are likely determinants of chemotherapy efficacy and toxicity. CT images are abundant, but these cannot be fully exploited unless there exist practical and fast approaches for tissue quantification. Here we propose a fully automated method for segmenting muscle, visceral and subcutaneous adipose tissues, taking the approach of shape modeling for the analysis of skeletal muscle. Muscle shape is represented using PCA encoded Free Form Deformations with respect to a mean shape. The shape model is learned from manually segmented images and used in conjunction with a tissue appearance prior. VAT and SAT are segmented based on the final deformed muscle shape. In comparing the automatic and manual methods, coefficients of variation (COV) (1 - 2%), were similar to or smaller than inter- and intra-observer COVs reported for manual segmentation.

  1. Stress Analysis of Bolted, Segmented Cylindrical Shells Exhibiting Flange Mating-Surface Waviness

    NASA Technical Reports Server (NTRS)

    Knight, Norman F., Jr.; Phillips, Dawn R.; Raju, Ivatury S.

    2009-01-01

    Bolted, segmented cylindrical shells are a common structural component in many engineering systems especially for aerospace launch vehicles. Segmented shells are often needed due to limitations of manufacturing capabilities or transportation issues related to very long, large-diameter cylindrical shells. These cylindrical shells typically have a flange or ring welded to opposite ends so that shell segments can be mated together and bolted to form a larger structural system. As the diameter of these shells increases, maintaining strict fabrication tolerances for the flanges to be flat and parallel on a welded structure is an extreme challenge. Local fit-up stresses develop in the structure due to flange mating-surface mismatch (flange waviness). These local stresses need to be considered when predicting a critical initial flaw size. Flange waviness is one contributor to the fit-up stress state. The present paper describes the modeling and analysis effort to simulate fit-up stresses due to flange waviness in a typical bolted, segmented cylindrical shell. Results from parametric studies are presented for various flange mating-surface waviness distributions and amplitudes.

  2. A multi-scale segmentation\\/object relationship modelling methodology for landscape analysis

    Microsoft Academic Search

    C. Burnett; Thomas Blaschke

    2003-01-01

    Natural complexity can best be explored using spatial analysis tools based on concepts of landscape as process continuums that can be partially decomposed into objects or patches. We introduce a five-step methodology based on multi-scale segmentation and object relationship modelling. Hierarchical patch dynamics (HPD) is adopted as the theoretical framework to address issues of heterogeneity, scale, connectivity and quasi-equilibriums in

  3. Texture analysis based on the Hermite transform for image classification and segmentation

    NASA Astrophysics Data System (ADS)

    Estudillo-Romero, Alfonso; Escalante-Ramirez, Boris; Savage-Carmona, Jesus

    2012-06-01

    Texture analysis has become an important task in image processing because it is used as a preprocessing stage in different research areas including medical image analysis, industrial inspection, segmentation of remote sensed imaginary, multimedia indexing and retrieval. In order to extract visual texture features a texture image analysis technique is presented based on the Hermite transform. Psychovisual evidence suggests that the Gaussian derivatives fit the receptive field profiles of mammalian visual systems. The Hermite transform describes locally basic texture features in terms of Gaussian derivatives. Multiresolution combined with several analysis orders provides detection of patterns that characterizes every texture class. The analysis of the local maximum energy direction and steering of the transformation coefficients increase the method robustness against the texture orientation. This method presents an advantage over classical filter bank design because in the latter a fixed number of orientations for the analysis has to be selected. During the training stage, a subset of the Hermite analysis filters is chosen in order to improve the inter-class separability, reduce dimensionality of the feature vectors and computational cost during the classification stage. We exhaustively evaluated the correct classification rate of real randomly selected training and testing texture subsets using several kinds of common used texture features. A comparison between different distance measurements is also presented. Results of the unsupervised real texture segmentation using this approach and comparison with previous approaches showed the benefits of our proposal.

  4. Recovery of Photoreceptor Outer Segment Length and Analysis of Membrane Assembly Rates in Regenerating Primate Photoreceptor Outer Segments

    Microsoft Academic Search

    Christopher J. Guerin; Geoffrey P. Lewis; Steven K. Fisher; Don H. Anderson

    Purpose. Photoreceptor outer segments are in a dynamic state of membrane addition and disposal. This study was undertaken to determine how a standardized period of retinal detach- ment and varying periods of reattachment affect the renewal process. Methods. To investigate the effects that retinal detachment and reattachment may have on this process, the neural retina from 12 adult rhesus monkeys

  5. MRI segmentation: Methods and applications

    Microsoft Academic Search

    L. P. Clarke; R. P. Velthuizen; M. A. Camacho; J. J. Heine; M. Vaidyanathan; L. O. Hall; R. W. Thatcher; M. L. Silbiger

    1995-01-01

    The current literature on MRI segmentation methods is reviewed. Particular emphasis is placed on the relative merits of single image versus multispectral segmentation, and supervised versus unsupervised segmentation methods. Image pre-processing and registration are discussed, as well as methods of validation. The application of MRI segmentation for tumor volume measurements during the course of therapy is presented here as an

  6. Multi-Modal Glioblastoma Segmentation: Man versus Machine

    PubMed Central

    Pica, Alessia; Schucht, Philippe; Beck, Jürgen; Verma, Rajeev Kumar; Slotboom, Johannes; Reyes, Mauricio; Wiest, Roland

    2014-01-01

    Background and Purpose Reproducible segmentation of brain tumors on magnetic resonance images is an important clinical need. This study was designed to evaluate the reliability of a novel fully automated segmentation tool for brain tumor image analysis in comparison to manually defined tumor segmentations. Methods We prospectively evaluated preoperative MR Images from 25 glioblastoma patients. Two independent expert raters performed manual segmentations. Automatic segmentations were performed using the Brain Tumor Image Analysis software (BraTumIA). In order to study the different tumor compartments, the complete tumor volume TV (enhancing part plus non-enhancing part plus necrotic core of the tumor), the TV+ (TV plus edema) and the contrast enhancing tumor volume CETV were identified. We quantified the overlap between manual and automated segmentation by calculation of diameter measurements as well as the Dice coefficients, the positive predictive values, sensitivity, relative volume error and absolute volume error. Results Comparison of automated versus manual extraction of 2-dimensional diameter measurements showed no significant difference (p?=?0.29). Comparison of automated versus manual segmentation of volumetric segmentations showed significant differences for TV+ and TV (p<0.05) but no significant differences for CETV (p>0.05) with regard to the Dice overlap coefficients. Spearman's rank correlation coefficients (?) of TV+, TV and CETV showed highly significant correlations between automatic and manual segmentations. Tumor localization did not influence the accuracy of segmentation. Conclusions In summary, we demonstrated that BraTumIA supports radiologists and clinicians by providing accurate measures of cross-sectional diameter-based tumor extensions. The automated volume measurements were comparable to manual tumor delineation for CETV tumor volumes, and outperformed inter-rater variability for overlap and sensitivity. PMID:24804720

  7. FEM correlation and shock analysis of a VNC MEMS mirror segment

    NASA Astrophysics Data System (ADS)

    Aguayo, Eduardo J.; Lyon, Richard; Helmbrecht, Michael; Khomusi, Sausan

    2014-08-01

    Microelectromechanical systems (MEMS) are becoming more prevalent in today's advanced space technologies. The Visible Nulling Coronagraph (VNC) instrument, being developed at the NASA Goddard Space Flight Center, uses a MEMS Mirror to correct wavefront errors. This MEMS Mirror, the Multiple Mirror Array (MMA), is a key component that will enable the VNC instrument to detect Jupiter and ultimately Earth size exoplanets. Like other MEMS devices, the MMA faces several challenges associated with spaceflight. Therefore, Finite Element Analysis (FEA) is being used to predict the behavior of a single MMA segment under different spaceflight-related environments. Finite Element Analysis results are used to guide the MMA design and ensure its survival during launch and mission operations. A Finite Element Model (FEM) has been developed of the MMA using COMSOL. This model has been correlated to static loading on test specimens. The correlation was performed in several steps—simple beam models were correlated initially, followed by increasingly complex and higher fidelity models of the MMA mirror segment. Subsequently, the model has been used to predict the dynamic behavior and stresses of the MMA segment in a representative spaceflight mechanical shock environment. The results of the correlation and the stresses associated with a shock event are presented herein.

  8. Segmentation of Unstructured Datasets

    NASA Technical Reports Server (NTRS)

    Bhat, Smitha

    1996-01-01

    Datasets generated by computer simulations and experiments in Computational Fluid Dynamics tend to be extremely large and complex. It is difficult to visualize these datasets using standard techniques like Volume Rendering and Ray Casting. Object Segmentation provides a technique to extract and quantify regions of interest within these massive datasets. This thesis explores basic algorithms to extract coherent amorphous regions from two-dimensional and three-dimensional scalar unstructured grids. The techniques are applied to datasets from Computational Fluid Dynamics and from Finite Element Analysis.

  9. Multiresolution analysis using wavelet, ridgelet, and curvelet transforms for medical image segmentation.

    PubMed

    Alzubi, Shadi; Islam, Naveed; Abbod, Maysam

    2011-01-01

    The experimental study presented in this paper is aimed at the development of an automatic image segmentation system for classifying region of interest (ROI) in medical images which are obtained from different medical scanners such as PET, CT, or MRI. Multiresolution analysis (MRA) using wavelet, ridgelet, and curvelet transforms has been used in the proposed segmentation system. It is particularly a challenging task to classify cancers in human organs in scanners output using shape or gray-level information; organs shape changes throw different slices in medical stack and the gray-level intensity overlap in soft tissues. Curvelet transform is a new extension of wavelet and ridgelet transforms which aims to deal with interesting phenomena occurring along curves. Curvelet transforms has been tested on medical data sets, and results are compared with those obtained from the other transforms. Tests indicate that using curvelet significantly improves the classification of abnormal tissues in the scans and reduce the surrounding noise. PMID:21960988

  10. Multiresolution Analysis Using Wavelet, Ridgelet, and Curvelet Transforms for Medical Image Segmentation

    PubMed Central

    AlZubi, Shadi; Islam, Naveed; Abbod, Maysam

    2011-01-01

    The experimental study presented in this paper is aimed at the development of an automatic image segmentation system for classifying region of interest (ROI) in medical images which are obtained from different medical scanners such as PET, CT, or MRI. Multiresolution analysis (MRA) using wavelet, ridgelet, and curvelet transforms has been used in the proposed segmentation system. It is particularly a challenging task to classify cancers in human organs in scanners output using shape or gray-level information; organs shape changes throw different slices in medical stack and the gray-level intensity overlap in soft tissues. Curvelet transform is a new extension of wavelet and ridgelet transforms which aims to deal with interesting phenomena occurring along curves. Curvelet transforms has been tested on medical data sets, and results are compared with those obtained from the other transforms. Tests indicate that using curvelet significantly improves the classification of abnormal tissues in the scans and reduce the surrounding noise. PMID:21960988

  11. Segmentation of fiber tracts based on an accuracy analysis on diffusion tensor software phantoms.

    PubMed

    Barbieri, Sebastiano; Bauer, Miriam H A; Klein, Jan; Nimsky, Christopher; Hahn, Horst K

    2011-03-15

    Due to its unique sensitivity to tissue microstructure, one of the primary applications of diffusion-weighted magnetic resonance imaging is the reconstruction of neural fiber pathways by means of fiber-tracking algorithms. In this work, we make use of realistic diffusion-tensor software phantoms in order to carry out an analysis of the precision of streamline tractography by systematically varying certain properties of the simulated image data (noise, tensor anisotropy, and image resolution) as well as certain fiber-tracking parameters (number of seed points and step length). Building upon the gained knowledge about the precision of the analyzed fiber-tracking algorithm, we proceed by suggesting a fuzzy segmentation algorithm for diffusion tensor images which better estimates the precise spatial extent of a tracked fiber bundle. The presented segmentation algorithm utilizes information given by the estimated main diffusion direction in a voxel and the respective uncertainty, and its validity is confirmed by both qualitative and quantitative analyses. PMID:21195777

  12. Profiling the different needs and expectations of patients for population-based medicine: a case study using segmentation analysis

    PubMed Central

    2012-01-01

    Background This study illustrates an evidence-based method for the segmentation analysis of patients that could greatly improve the approach to population-based medicine, by filling a gap in the empirical analysis of this topic. Segmentation facilitates individual patient care in the context of the culture, health status, and the health needs of the entire population to which that patient belongs. Because many health systems are engaged in developing better chronic care management initiatives, patient profiles are critical to understanding whether some patients can move toward effective self-management and can play a central role in determining their own care, which fosters a sense of responsibility for their own health. A review of the literature on patient segmentation provided the background for this research. Method First, we conducted a literature review on patient satisfaction and segmentation to build a survey. Then, we performed 3,461 surveys of outpatient services users. The key structures on which the subjects’ perception of outpatient services was based were extrapolated using principal component factor analysis with varimax rotation. After the factor analysis, segmentation was performed through cluster analysis to better analyze the influence of individual attitudes on the results. Results Four segments were identified through factor and cluster analysis: the “unpretentious,” the “informed and supported,” the “experts” and the “advanced” patients. Their policies and managerial implications are outlined. Conclusions With this research, we provide the following: – a method for profiling patients based on common patient satisfaction surveys that is easily replicable in all health systems and contexts; – a proposal for segments based on the results of a broad-based analysis conducted in the Italian National Health System (INHS). Segments represent profiles of patients requiring different strategies for delivering health services. Their knowledge and analysis might support an effort to build an effective population-based medicine approach. PMID:23256543

  13. Evaluation metrics for bone segmentation in ultrasound

    NASA Astrophysics Data System (ADS)

    Lougheed, Matthew; Fichtinger, Gabor; Ungi, Tamas

    2015-03-01

    Tracked ultrasound is a safe alternative to X-ray for imaging bones. The interpretation of bony structures is challenging as ultrasound has no specific intensity characteristic of bones. Several image segmentation algorithms have been devised to identify bony structures. We propose an open-source framework that would aid in the development and comparison of such algorithms by quantitatively measuring segmentation performance in the ultrasound images. True-positive and false-negative metrics used in the framework quantify algorithm performance based on correctly segmented bone and correctly segmented boneless regions. Ground-truth for these metrics are defined manually and along with the corresponding automatically segmented image are used for the performance analysis. Manually created ground truth tests were generated to verify the accuracy of the analysis. Further evaluation metrics for determining average performance per slide and standard deviation are considered. The metrics provide a means of evaluating accuracy of frames along the length of a volume. This would aid in assessing the accuracy of the volume itself and the approach to image acquisition (positioning and frequency of frame). The framework was implemented as an open-source module of the 3D Slicer platform. The ground truth tests verified that the framework correctly calculates the implemented metrics. The developed framework provides a convenient way to evaluate bone segmentation algorithms. The implementation fits in a widely used application for segmentation algorithm prototyping. Future algorithm development will benefit by monitoring the effects of adjustments to an algorithm in a standard evaluation framework.

  14. Comparison of Five Segmentation Tools for {sup 18}F-Fluoro-Deoxy-Glucose-Positron Emission Tomography-Based Target Volume Definition in Head and Neck Cancer

    SciTech Connect

    Schinagl, Dominic A.X. [Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)], E-mail: d.schinagl@rther.umcn.nl; Vogel, Wouter V. [Department of Nuclear Medicine, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Hoffmann, Aswin L. [Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Dalen, Jorn A. van; Oyen, Wim J. [Department of Nuclear Medicine, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Kaanders, Johannes H.A.M. [Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)

    2007-11-15

    Purpose: Target-volume delineation for radiation treatment to the head and neck area traditionally is based on physical examination, computed tomography (CT), and magnetic resonance imaging. Additional molecular imaging with {sup 18}F-fluoro-deoxy-glucose (FDG)-positron emission tomography (PET) may improve definition of the gross tumor volume (GTV). In this study, five methods for tumor delineation on FDG-PET are compared with CT-based delineation. Methods and Materials: Seventy-eight patients with Stages II-IV squamous cell carcinoma of the head and neck area underwent coregistered CT and FDG-PET. The primary tumor was delineated on CT, and five PET-based GTVs were obtained: visual interpretation, applying an isocontour of a standardized uptake value of 2.5, using a fixed threshold of 40% and 50% of the maximum signal intensity, and applying an adaptive threshold based on the signal-to-background ratio. Absolute GTV volumes were compared, and overlap analyses were performed. Results: The GTV method of applying an isocontour of a standardized uptake value of 2.5 failed to provide successful delineation in 45% of cases. For the other PET delineation methods, volume and shape of the GTV were influenced heavily by the choice of segmentation tool. On average, all threshold-based PET-GTVs were smaller than on CT. Nevertheless, PET frequently detected significant tumor extension outside the GTV delineated on CT (15-34% of PET volume). Conclusions: The choice of segmentation tool for target-volume definition of head and neck cancer based on FDG-PET images is not trivial because it influences both volume and shape of the resulting GTV. With adequate delineation, PET may add significantly to CT- and physical examination-based GTV definition.

  15. Multivariate statistical analysis as a tool for the segmentation of 3D spectral data.

    PubMed

    Lucas, G; Burdet, P; Cantoni, M; Hébert, C

    2013-01-01

    Acquisition of three-dimensional (3D) spectral data is nowadays common using many different microanalytical techniques. In order to proceed to the 3D reconstruction, data processing is necessary not only to deal with noisy acquisitions but also to segment the data in term of chemical composition. In this article, we demonstrate the value of multivariate statistical analysis (MSA) methods for this purpose, allowing fast and reliable results. Using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) coupled with a focused ion beam (FIB), a stack of spectrum images have been acquired on a sample produced by laser welding of a nickel-titanium wire and a stainless steel wire presenting a complex microstructure. These data have been analyzed using principal component analysis (PCA) and factor rotations. PCA allows to significantly improve the overall quality of the data, but produces abstract components. Here it is shown that rotated components can be used without prior knowledge of the sample to help the interpretation of the data, obtaining quickly qualitative mappings representative of elements or compounds found in the material. Such abundance maps can then be used to plot scatter diagrams and interactively identify the different domains in presence by defining clusters of voxels having similar compositions. Identified voxels are advantageously overlaid on secondary electron (SE) images with higher resolution in order to refine the segmentation. The 3D reconstruction can then be performed using available commercial softwares on the basis of the provided segmentation. To asses the quality of the segmentation, the results have been compared to an EDX quantification performed on the same data. PMID:24035679

  16. Combined Finite Element --Finite Volume Method ( Convergence Analysis )

    E-print Network

    Magdeburg, Universität

    Combined Finite Element -- Finite Volume Method ( Convergence Analysis ) M'aria Luk idea is to combine finite volume and finite element methods in an appropriate way. Thus nonlinear grid. Diffusion terms are discretized by the conforming piecewise linear finite element method

  17. FIELD VALIDATION OF EXPOSURE ASSESSMENT MODELS. VOLUME 2. ANALYSIS

    EPA Science Inventory

    This is the second of two volumes describing a series of dual tracer experiments designed to evaluate the PAL-DS model, a Gaussian diffusion model modified to take into account settling and deposition, as well as three other deposition models. In this volume, an analysis of the d...

  18. Twitter Volume Spikes: Analysis and Application in Stock Trading

    E-print Network

    Wang, Bing

    Twitter Volume Spikes: Analysis and Application in Stock Trading Yuexin Mao University bing@engr.uconn.edu ABSTRACT Stock is a popular topic in Twitter. The number of tweets concern- ing Twitter volume spikes related to S&P 500 stocks, and whether they are useful for stock trading. Through

  19. Reliable cell segmentation based on spectral phasor analysis of hyperspectral stimulated Raman scattering imaging data.

    PubMed

    Fu, Dan; Xie, X Sunney

    2014-05-01

    Hyperspectral stimulated Raman scattering (SRS) imaging has rapidly become an emerging tool for high content analyses of cell and tissue systems. The label-free nature of SRS imaging combined with its chemical specificity allows in situ and in vivo biochemical quantification at submicrometer resolution without sectioning and staining. Current hyperspectral SRS data analysis methods are based on either linear unmixing or multivariate analysis, which are not sensitive to small spectral variations and often provide obscure information on the cell composition. Here, we demonstrate a spectral phasor analysis method that allows fast and reliable cellular organelle segmentation of mammalian cells, without any a priori knowledge of their composition or basis spectra. We further show that, in combination with a branch-bound algorithm for optimal selection of a few wavenumbers, spectral phasor analysis provides a robust solution to label-free single cell analysis. PMID:24684208

  20. Tumor segmentation from breast magnetic resonance images using independent component texture analysis

    NASA Astrophysics Data System (ADS)

    Yang, Sheng-Chih; Huang, Chieh-Ling; Chang, Tsai-Rong; Lin, Chi-Yuan

    2013-04-01

    A new spectral signature analysis method for tumor segmentation in breast magnetic resonance images is presented. The proposed method is called an independent component texture analysis (ICTA), which consists of three techniques including independent component analysis (ICA), entropy-based thresholding, and texture feature registration (TFR). ICTA was mainly developed to resolve the inconsistency in the results of independent components (ICs) due to the random initial projection vector of ICA and then accordingly determine the most likely IC. A series of experiments were conducted to compare and evaluate ICTA with principal component texture analysis, traditional ICA, traditional principal component analysis (PCA), fuzzy c-means, constrained energy minimization, and orthogonal subspace projection methods. The experimental results showed that ICTA had higher efficiency than existing methods.

  1. Swept Volume Parameterization for Isogeometric Analysis

    E-print Network

    Jüttler, Bert

    of interesting free-form shapes, such as blades of turbines and propellers, ship hulls or wings of airplanes param- eterizations of swept volumes, which are obtained by sweeping a closed curve through space

  2. An analysis of the segmentation threshold used in axial-shear strain elastography.

    PubMed

    Thittai, Arun K; Xia, Rongmin

    2015-01-01

    Axial-shear strain elastography was introduced recently to image the tumor-host tissue boundary bonding characteristics. The image depicting the axial-shear strain distribution in a tissue under axial compression was termed as an axial-shear strain elastogram (ASSE). It has been demonstrated through simulation, tissue-mimicking phantom experiments, and retrospective analysis of in vivo breast lesion data that metrics quantifying the pattern of axial-shear strain distribution on ASSE can be used as features for identifying the lesion boundary condition as loosely-bonded or firmly-bonded. Consequently, features from ASSE have been shown to have potential in non-invasive breast lesion classification into benign versus malignant. Although there appears to be a broad concurrence in the results reported by different groups, important details pertaining to the appropriate segmentation threshold needed for - (1) displaying the ASSE as a color-overlay on top of corresponding Axial Strain Elastogram (ASE) and/or sonogram for feature visualization and (2) ASSE feature extraction are not yet fully addressed. In this study, we utilize ASSE from tissue mimicking phantom (with loosely-bonded and firmly-bonded inclusions) experiments and freehand - acquired in vivo breast lesion data (7 benign and 9 malignant) to analyze the effect of segmentation threshold on ASSE feature value, specifically, the "fill-in" feature that was introduced recently. We varied the segmentation threshold from 20% to 70% (of the maximum ASSE value) for each frame of the acquisition cine-loop of every data and computed the number of ASSE pixels within the lesion that was greater than or equal to this threshold value. If at least 40% of the pixels within the lesion area crossed this segmentation threshold, the ASSE frame was considered to demonstrate a "fill-in" that would indicate a loosely-bonded lesion boundary condition (suggestive of a benign lesion). Otherwise, the ASSE frame was considered not to demonstrate a "fill-in" indicating a firmly-bonded lesion boundary condition (suggestive of a malignant lesion). The results demonstrate that in the case of in vivo breast lesion data the appropriate range for the segmentation threshold value seems to be 40-60%. It was noted that for a segmentation threshold within this range (for example, at 50%) all of the analyzed breast lesion cases can be correctly classified into benign and malignant, based on the percentage number of frames within the acquisition cine-loop that demonstrate a "fill-in". PMID:25173068

  3. Local multifractal detrended fluctuation analysis for non-stationary image's texture segmentation

    NASA Astrophysics Data System (ADS)

    Wang, Fang; Li, Zong-shou; Li, Jin-wei

    2014-12-01

    Feature extraction plays a great important role in image processing and pattern recognition. As a power tool, multifractal theory is recently employed for this job. However, traditional multifractal methods are proposed to analyze the objects with stationary measure and cannot for non-stationary measure. The works of this paper is twofold. First, the definition of stationary image and 2D image feature detection methods are proposed. Second, a novel feature extraction scheme for non-stationary image is proposed by local multifractal detrended fluctuation analysis (Local MF-DFA), which is based on 2D MF-DFA. A set of new multifractal descriptors, called local generalized Hurst exponent (Lhq) is defined to characterize the local scaling properties of textures. To test the proposed method, both the novel texture descriptor and other two multifractal indicators, namely, local Hölder coefficients based on capacity measure and multifractal dimension Dq based on multifractal differential box-counting (MDBC) method, are compared in segmentation experiments. The first experiment indicates that the segmentation results obtained by the proposed Lhq are better than the MDBC-based Dq slightly and superior to the local Hölder coefficients significantly. The results in the second experiment demonstrate that the Lhq can distinguish the texture images more effectively and provide more robust segmentations than the MDBC-based Dq significantly.

  4. Advanced finite element analysis of L4-L5 implanted spine segment

    NASA Astrophysics Data System (ADS)

    Pawlikowski, Marek; Doma?ski, Janusz; Suchocki, Cyprian

    2014-03-01

    In the paper finite element (FE) analysis of implanted lumbar spine segment is presented. The segment model consists of two lumbar vertebrae L4 and L5 and the prosthesis. The model of the intervertebral disc prosthesis consists of two metallic plates and a polyurethane core. Bone tissue is modelled as a linear viscoelastic material. The prosthesis core is made of a polyurethane nanocomposite. It is modelled as a non-linear viscoelastic material. The constitutive law of the core, derived in one of the previous papers, is implemented into the FE software Abaqus®. It was done by means of the User-supplied procedure UMAT. The metallic plates are elastic. The most important parts of the paper include: description of the prosthesis geometrical and numerical modelling, mathematical derivation of stiffness tensor and Kirchhoff stress and implementation of the constitutive model of the polyurethane core into Abaqus® software. Two load cases were considered, i.e. compression and stress relaxation under constant displacement. The goal of the paper is to numerically validate the constitutive law, which was previously formulated, and to perform advanced FE analyses of the implanted L4-L5 spine segment in which non-standard constitutive law for one of the model materials, i.e. the prosthesis core, is implemented.

  5. Analysis of gene expression levels in individual bacterial cells without image segmentation

    PubMed Central

    Kwak, In Hae; Son, Minjun; Hagen, Stephen J.

    2012-01-01

    Studies of stochasticity in gene expression typically make use of fluorescent protein reporters, which permit the measurement of expression levels within individual cells by fluorescence microscopy. Analysis of such microscopy images is almost invariably based on a segmentation algorithm, where the image of a cell or cluster is analyzed mathematically to delineate individual cell boundaries. However segmentation can be ineffective for studying bacterial cells or clusters, especially at lower magnification, where outlines of individual cells are poorly resolved. Here we demonstrate an alternative method for analysing such images without segmentation. The method employs a comparison between the pixel brightness in phase contrast vs. fluorescence microscopy images. By fitting the correlation between phase contrast and fluorescence intensity to a physical model, we obtain well-defined estimates for the different expression levels of gene expression that are present in the cell or cluster. The method reveals the boundaries of the individual cells, even if the source images lack the resolution to show these boundaries clearly. PMID:22487793

  6. Improved disparity map analysis through the fusion of monocular image segmentations

    NASA Technical Reports Server (NTRS)

    Perlant, Frederic P.; Mckeown, David M.

    1991-01-01

    The focus is to examine how estimates of three dimensional scene structure, as encoded in a scene disparity map, can be improved by the analysis of the original monocular imagery. The utilization of surface illumination information is provided by the segmentation of the monocular image into fine surface patches of nearly homogeneous intensity to remove mismatches generated during stereo matching. These patches are used to guide a statistical analysis of the disparity map based on the assumption that such patches correspond closely with physical surfaces in the scene. Such a technique is quite independent of whether the initial disparity map was generated by automated area-based or feature-based stereo matching. Stereo analysis results are presented on a complex urban scene containing various man-made and natural features. This scene contains a variety of problems including low building height with respect to the stereo baseline, buildings and roads in complex terrain, and highly textured buildings and terrain. The improvements are demonstrated due to monocular fusion with a set of different region-based image segmentations. The generality of this approach to stereo analysis and its utility in the development of general three dimensional scene interpretation systems are also discussed.

  7. Quantitative analysis of volume images -electron microscopic tomography of HIV

    E-print Network

    Nyström, Ingela

    Quantitative analysis of volume images - electron microscopic tomography of HIV Ingela Nystr to assist in the structural analysis of the causative virus of the AIDS disease, HIV. Especially interestingom, Ewert Bengtsson, Bo Nordin Centre for Image Analysis Uppsala University, Sweden Gunilla Borgefors Centre

  8. Surface Analysis from Video Volumes for Fetal Alcohol Syndrome Classification

    Microsoft Academic Search

    Shiaofen Fang; Ying Liu; Sophia Vinci-Booher; Bruce Anthony; Feng Zhou

    2010-01-01

    3D shape reconstruction is often a necessary step to obtain geometric information from multiple 2D images for shape analysis. In this paper, a new shape analysis technique is proposed using surface features derived directly from the video volume of 2D images. It avoids the explicit 3D reconstruction process, which is often not very robust and accurate for surface feature analysis.

  9. Segmenting the fly embryo: logical analysis of the role of the segment polarity cross-regulatory module.

    PubMed

    Sánchez, Lucas; Chaouiya, Claudine; Thieffry, Denis

    2008-01-01

    Initially activated by the pair-rule genes, the expression patterns of the segment polarity genes engrailed and wingless become consolidated through inter-cellular interactions between juxtaposed cells. We delineate a logical model focusing on a dozen molecular components at the core of the regulatory network controlling this process. Our model leads to the following conclusions: (1) the pair-rule signals, which activate engrailed and wingless genes independently of each other, need to be operative until the inter-cellular circuit involving these two genes is functional. This implies that the pair-rule pattern is instrumental both in determining the activation of the genes engrailed and wingless in rows of adjacent cells, and in consolidating these expression patterns; (2) the consolidation of engrailed and wingless expression patterns requires the simultaneous activation of both autocrine and paracrine Wingless-pathways, and the Hedgehog pathway; (3) protein kinase A plays at least two roles through the phosphorylation of Cubitus interruptus, the effector molecule of the Hedgehog signalling pathway and (4) the roles of Sloppy-paired and Naked in the delineation of the engrailed and wingless expression domains are emphasized as being important for segmental boundary formation. Moreover, the application of an original computational method leads to the delineation of a subset of crucial regulatory circuits enabling the coexistence of specific expression states at the cellular level, as well as specific combination of cellular states inter-connected through Wingless and Hedgehog signalling. Finally, the simulation of altered expressions of segment polarity genes leads to results consistent with the published data. PMID:18956339

  10. IEEE GEOSCIENCE AND REMOTE SENSING LETTERS, VOL. 6, NO. 4, OCTOBER 2009 713 Segmented Principal Component Analysis for

    E-print Network

    Fowler, James E.

    Component Analysis for Parallel Compression of Hyperspectral Imagery Qian Du, Senior Member, IEEE, Wei Zhu of hyperspectral imagery, JPEG2000 coupled with principal component analysis (PCA) for spectral decorrelation compression, principal compo- nent analysis (PCA), spectral segmentation. I. INTRODUCTION FOR THE compression

  11. Texture analysis improves level set segmentation of the anterior abdominal wall

    SciTech Connect

    Xu, Zhoubing [Electrical Engineering, Vanderbilt University, Nashville, Tennessee 37235 (United States)] [Electrical Engineering, Vanderbilt University, Nashville, Tennessee 37235 (United States); Allen, Wade M. [Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee 37235 (United States)] [Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee 37235 (United States); Baucom, Rebeccah B.; Poulose, Benjamin K. [General Surgery, Vanderbilt University Medical Center, Nashville, Tennessee 37235 (United States)] [General Surgery, Vanderbilt University Medical Center, Nashville, Tennessee 37235 (United States); Landman, Bennett A. [Electrical Engineering, Vanderbilt University, Nashville, Tennessee 37235 and Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee 37235 (United States)] [Electrical Engineering, Vanderbilt University, Nashville, Tennessee 37235 and Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee 37235 (United States)

    2013-12-15

    Purpose: The treatment of ventral hernias (VH) has been a challenging problem for medical care. Repair of these hernias is fraught with failure; recurrence rates ranging from 24% to 43% have been reported, even with the use of biocompatible mesh. Currently, computed tomography (CT) is used to guide intervention through expert, but qualitative, clinical judgments, notably, quantitative metrics based on image-processing are not used. The authors propose that image segmentation methods to capture the three-dimensional structure of the abdominal wall and its abnormalities will provide a foundation on which to measure geometric properties of hernias and surrounding tissues and, therefore, to optimize intervention.Methods: In this study with 20 clinically acquired CT scans on postoperative patients, the authors demonstrated a novel approach to geometric classification of the abdominal. The authors’ approach uses a texture analysis based on Gabor filters to extract feature vectors and follows a fuzzy c-means clustering method to estimate voxelwise probability memberships for eight clusters. The memberships estimated from the texture analysis are helpful to identify anatomical structures with inhomogeneous intensities. The membership was used to guide the level set evolution, as well as to derive an initial start close to the abdominal wall.Results: Segmentation results on abdominal walls were both quantitatively and qualitatively validated with surface errors based on manually labeled ground truth. Using texture, mean surface errors for the outer surface of the abdominal wall were less than 2 mm, with 91% of the outer surface less than 5 mm away from the manual tracings; errors were significantly greater (2–5 mm) for methods that did not use the texture.Conclusions: The authors’ approach establishes a baseline for characterizing the abdominal wall for improving VH care. Inherent texture patterns in CT scans are helpful to the tissue classification, and texture analysis can improve the level set segmentation around the abdominal region.

  12. Volume accumulator design analysis computer codes

    NASA Technical Reports Server (NTRS)

    Whitaker, W. D.; Shimazaki, T. T.

    1973-01-01

    The computer codes, VANEP and VANES, were written and used to aid in the design and performance calculation of the volume accumulator units (VAU) for the 5-kwe reactor thermoelectric system. VANEP computes the VAU design which meets the primary coolant loop VAU volume and pressure performance requirements. VANES computes the performance of the VAU design, determined from the VANEP code, at the conditions of the secondary coolant loop. The codes can also compute the performance characteristics of the VAU's under conditions of possible modes of failure which still permit continued system operation.

  13. Drive system design and error analysis of the 6 degrees of freedom segment erector of shield tunneling machine

    NASA Astrophysics Data System (ADS)

    Shi, Hu; Gong, Guofang; Yang, Huayong

    2011-09-01

    Focusing on a segment erector of a shield-tunneling machine developed with 6 degrees of freedom (DOF) and controlled by electro-hydraulic proportional systems, the kinematics of the segment erection process is presented. The perturbation method in the error analysis is introduced to establish the position and attitude error model, considering a number of factors such as the hydraulic drive, control accuracy, and tolerance in manufacturing and assembly. Dynamic simulations are carried out to obtain the controlling precision of electrohydraulic drive systems. Formulas for calculating the position and attitude error of the grip hand of the segment erector are derived. The calculation results verify the practicality and effectiveness of the error analysis, providing a foundation for practical designing, manufacturing, and assembling of the segment of the erecting mechanism.

  14. Mosaicism in Segmental Darier Disease: An In-Depth Molecular Analysis Quantifying Proportions of Mutated Alleles in Various Tissues

    Microsoft Academic Search

    Theresa Larriba Harboe; Patrick Willems; Cathrine Jespersgaard; Marie Louise Mølgaard Poulsen; Flemming Brandt Sørensen; Marie Luise Bisgaard

    2011-01-01

    Darier disease is an autosomal dominant genodermatosis caused by germline mutations in the ATP2A2 gene. Clinical expression is variable, including rare segmental phenotypes thought to be caused by postzygotic mosaicism. Genetic counseling of segmental Darier patients is complex, as risk of transmitting a nonsegmental phenotype to offspring is of unknown magnitude. We present the first in-depth molecular analysis of a

  15. SNP discovery and haplotype analysis in the segmentally duplicated DRD5 coding region

    PubMed Central

    HOUSLEY, D. J. E.; NIKOLAS, M.; VENTA, P. J.; JERNIGAN, K. A.; WALDMAN, I. D.; NIGG, J. T.; FRIDERICI, K. H.

    2009-01-01

    SUMMARY The dopamine receptor 5 gene (DRD5) holds much promise as a candidate locus for contributing to neuropsychiatric disorders and other diseases influenced by the dopaminergic system, as well as having potential to affect normal behavioral variation. However, detailed analyses of this gene have been complicated by its location within a segmentally duplicated chromosomal region. Microsatellites and SNPs upstream from the coding region have been used for association studies, but we find, using bioinformatics resources, that these markers all lie within a previously unrecognized second segmental duplication (SD). In order to accurately analyze the DRD5 locus for polymorphisms in the absence of contaminating pseudogene sequences, we developed a fast and reliable method for sequence analysis and genotyping within the DRD5 coding region. We employed restriction enzyme digestion of genomic DNA to eliminate the pseudogenes prior to PCR amplification of the functional gene. This approach allowed us to determine the DRD5 haplotype structure using 31 trios and to reveal additional rare variants in 171 unrelated individuals. We clarify the inconsistencies and errors of the recorded SNPs in dbSNP and HapMap and illustrate the importance of using caution when choosing SNPs in regions of suspected duplications. The simple and relatively inexpensive method presented herein allows for convenient analysis of sequence variation in DRD5 and can be easily adapted to other duplicated genomic regions in order to obtain good quality sequence data. PMID:19397556

  16. A Novel Segmentation, Mutual Information Network Framework for EEG Analysis of Motor Tasks

    PubMed Central

    Wang, Z Jane; Lee, Pamela Wen-Hsin; McKeown, Martin J

    2009-01-01

    Background Monitoring the functional connectivity between brain regions is becoming increasingly important in elucidating brain functionality in normal and disease states. Current methods of detecting networks in the recorded electroencephalogram (EEG) such as correlation and coherence are limited by the fact that they assume stationarity of the relationship between channels, and rely on linear dependencies. In contrast to diseases of the brain cortex (e.g. Alzheimer's disease), with motor disorders such as Parkinson's disease (PD) the EEG abnormalities are most apparent during performance of dynamic motor tasks, but this makes the stationarity assumption untenable. Methods We therefore propose a novel EEG segmentation method based on the temporal dynamics of the cross-spectrogram of the computed Independent Components (ICs). We then utilize mutual information (MI) as the metric for determining also nonlinear statistical dependencies between EEG channels. Graphical theoretical analysis is then applied to the derived MI networks. The method was applied to EEG data recorded from six normal subjects and seven PD subjects off medication. One-way analysis of variance (ANOVA) tests demonstrated statistically significant difference in the connectivity patterns between groups. Results The results suggested that PD subjects are unable to independently recruit different areas of the brain while performing simultaneous tasks compared to individual tasks, but instead they attempt to recruit disparate clusters of synchronous activity to maintain behavioral performance. Conclusion The proposed segmentation/MI network method appears to be a promising approach for analyzing the EEG recorded during dynamic behaviors. PMID:19413908

  17. Segmented Compressed Sampling for Analog-to-Information Conversion: Method and Performance Analysis

    Microsoft Academic Search

    Omid Taheri; Sergiy A. Vorobyov

    2011-01-01

    A new segmented compressed sampling (CS) method foranalog-to-information conversion(AIC)isproposed.Ananalog signal measured by a number of parallel branches of mixers and integrators (BMIs), each characterized by a specific random sam- pling waveform, is first segmented in time into segments. Then the subsamples collected on different segments and different BMIs are reused so that a larger number of samples (at most )

  18. An Integrated Segmentation and Classification Approach Applied to Multiple Sclerosis Analysis

    Microsoft Academic Search

    Ayelet Akselrod-ballin; Meirav Galun; Ronen Basri; Achi Brandt; Moshe John Gomori; Massimo Filippi; Paula Valsasina

    2006-01-01

    We present a novel multiscale approach that combines segmentation with classification to detect abnormal brain structures in medical imagery, and demonstrate its utility in detecting multiple sclerosis lesions in 3D MRI data. Our method uses segmentation to obtain a hierarchical decom- position of a multi-channel, anisotropic MRI scan. It then produces a rich set of features describing the segments in

  19. Sequencing and analysis of chromosome 1 of Eimeria tenella reveals a unique segmental organization

    PubMed Central

    Ling, King-Hwa; Rajandream, Marie-Adele; Rivailler, Pierre; Ivens, Alasdair; Yap, Soon-Joo; Madeira, Alda M.B.N.; Mungall, Karen; Billington, Karen; Yee, Wai-Yan; Bankier, Alan T.; Carroll, Fionnadh; Durham, Alan M.; Peters, Nicholas; Loo, Shu-San; Mat Isa, Mohd Noor; Novaes, Jeniffer; Quail, Michael; Rosli, Rozita; Nor Shamsudin, Mariana; Sobreira, Tiago J.P.; Tivey, Adrian R.; Wai, Siew-Fun; White, Sarah; Wu, Xikun; Kerhornou, Arnaud; Blake, Damer; Mohamed, Rahmah; Shirley, Martin; Gruber, Arthur; Berriman, Matthew; Tomley, Fiona; Dear, Paul H.; Wan, Kiew-Lian

    2007-01-01

    Eimeria tenella is an intracellular protozoan parasite that infects the intestinal tracts of domestic fowl and causes coccidiosis, a serious and sometimes lethal enteritis. Eimeria falls in the same phylum (Apicomplexa) as several human and animal parasites such as Cryptosporidium, Toxoplasma, and the malaria parasite, Plasmodium. Here we report the sequencing and analysis of the first chromosome of E. tenella, a chromosome believed to carry loci associated with drug resistance and known to differ between virulent and attenuated strains of the parasite. The chromosome—which appears to be representative of the genome—is gene-dense and rich in simple-sequence repeats, many of which appear to give rise to repetitive amino acid tracts in the predicted proteins. Most striking is the segmentation of the chromosome into repeat-rich regions peppered with transposon-like elements and telomere-like repeats, alternating with repeat-free regions. Predicted genes differ in character between the two types of segment, and the repeat-rich regions appear to be associated with strain-to-strain variation. PMID:17284678

  20. Theoretical analysis of segmented Wolter/LSM X-ray telescope systems

    NASA Technical Reports Server (NTRS)

    Shealy, D. L.; Chao, S. H.

    1986-01-01

    The Segmented Wolter I/LSM X-ray Telescope, which consists of a Wolter I Telescope with a tilted, off-axis convex spherical Layered Synthetic Microstructure (LSM) optics placed near the primary focus to accommodate multiple off-axis detectors, has been analyzed. The Skylab ATM Experiment S056 Wolter I telescope and the Stanford/MSFC nested Wolter-Schwarzschild x-ray telescope have been considered as the primary optics. A ray trace analysis has been performed to calculate the RMS blur circle radius, point spread function (PSF), the meridional and sagittal line functions (LST), and the full width half maximum (PWHM) of the PSF to study the spatial resolution of the system. The effects on resolution of defocussing the image plane, tilting and decentrating of the multilayer (LSM) optics have also been investigated to give the mounting and alignment tolerances of the LSM optic. Comparison has been made between the performance of the segmented Wolter/LSM optical system and that of the Spectral Slicing X-ray Telescope (SSXRT) systems.

  1. Investigating materials for breast nodules simulation by using segmentation and similarity analysis of digital images

    NASA Astrophysics Data System (ADS)

    Siqueira, Paula N.; Marcomini, Karem D.; Sousa, Maria A. Z.; Schiabel, Homero

    2015-03-01

    The task of identifying the malignancy of nodular lesions on mammograms becomes quite complex due to overlapped structures or even to the granular fibrous tissue which can cause confusion in classifying masses shape, leading to unnecessary biopsies. Efforts to develop methods for automatic masses detection in CADe (Computer Aided Detection) schemes have been made with the aim of assisting radiologists and working as a second opinion. The validation of these methods may be accomplished for instance by using databases with clinical images or acquired through breast phantoms. With this aim, some types of materials were tested in order to produce radiographic phantom images which could characterize a good enough approach to the typical mammograms corresponding to actual breast nodules. Therefore different nodules patterns were physically produced and used on a previous developed breast phantom. Their characteristics were tested according to the digital images obtained from phantom exposures at a LORAD M-IV mammography unit. Two analysis were realized the first one by the segmentation of regions of interest containing the simulated nodules by an automated segmentation technique as well as by an experienced radiologist who has delineated the contour of each nodule by means of a graphic display digitizer. Both results were compared by using evaluation metrics. The second one used measure of quality Structural Similarity (SSIM) to generate quantitative data related to the texture produced by each material. Although all the tested materials proved to be suitable for the study, the PVC film yielded the best results.

  2. Model parameter estimation and tissue mixture segmentation by a MAP-EM algorithm

    Microsoft Academic Search

    Zhengrong Liang; Su Wang; Hongye Lu; Jing Wang

    2007-01-01

    Quantitative volumetric measurement and feature analysis for various clinical applications require image segmentation. Most important clinical features are derived from the borders of a region of interest, which reflects the shape characteristics and volumetric variation of the target. The partial volume (PV) effect renders a significant error for current hard segmentation which assigns a single tissue label to each image

  3. A Comparison of Amplitude-Based and Phase-Based Positron Emission Tomography Gating Algorithms for Segmentation of Internal Target Volumes of Tumors Subject to Respiratory Motion

    SciTech Connect

    Jani, Shyam S., E-mail: sjani@mednet.ucla.edu [Department of Radiation Oncology, David Geffen School of Medicine, University of California, Los Angeles, California (United States); Robinson, Clifford G. [Department of Radiation Oncology, Siteman Cancer Center, Washington University in St Louis, St Louis, Missouri (United States); Dahlbom, Magnus [Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, California (United States); White, Benjamin M.; Thomas, David H.; Gaudio, Sergio; Low, Daniel A.; Lamb, James M. [Department of Radiation Oncology, David Geffen School of Medicine, University of California, Los Angeles, California (United States)

    2013-11-01

    Purpose: To quantitatively compare the accuracy of tumor volume segmentation in amplitude-based and phase-based respiratory gating algorithms in respiratory-correlated positron emission tomography (PET). Methods and Materials: List-mode fluorodeoxyglucose-PET data was acquired for 10 patients with a total of 12 fluorodeoxyglucose-avid tumors and 9 lymph nodes. Additionally, a phantom experiment was performed in which 4 plastic butyrate spheres with inner diameters ranging from 1 to 4 cm were imaged as they underwent 1-dimensional motion based on 2 measured patient breathing trajectories. PET list-mode data were gated into 8 bins using 2 amplitude-based (equal amplitude bins [A1] and equal counts per bin [A2]) and 2 temporal phase-based gating algorithms. Gated images were segmented using a commercially available gradient-based technique and a fixed 40% threshold of maximum uptake. Internal target volumes (ITVs) were generated by taking the union of all 8 contours per gated image. Segmented phantom ITVs were compared with their respective ground-truth ITVs, defined as the volume subtended by the tumor model positions covering 99% of breathing amplitude. Superior-inferior distances between sphere centroids in the end-inhale and end-exhale phases were also calculated. Results: Tumor ITVs from amplitude-based methods were significantly larger than those from temporal-based techniques (P=.002). For lymph nodes, A2 resulted in ITVs that were significantly larger than either of the temporal-based techniques (P<.0323). A1 produced the largest and most accurate ITVs for spheres with diameters of ?2 cm (P=.002). No significant difference was shown between algorithms in the 1-cm sphere data set. For phantom spheres, amplitude-based methods recovered an average of 9.5% more motion displacement than temporal-based methods under regular breathing conditions and an average of 45.7% more in the presence of baseline drift (P<.001). Conclusions: Target volumes in images generated from amplitude-based gating are larger and more accurate, at levels that are potentially clinically significant, compared with those from temporal phase-based gating.

  4. Final safety analysis report for the Galileo Mission: Volume 2, Book 2: Accident model document: Appendices

    SciTech Connect

    Not Available

    1988-12-15

    This section of the Accident Model Document (AMD) presents the appendices which describe the various analyses that have been conducted for use in the Galileo Final Safety Analysis Report II, Volume II. Included in these appendices are the approaches, techniques, conditions and assumptions used in the development of the analytical models plus the detailed results of the analyses. Also included in these appendices are summaries of the accidents and their associated probabilities and environment models taken from the Shuttle Data Book (NSTS-08116), plus summaries of the several segments of the recent GPHS safety test program. The information presented in these appendices is used in Section 3.0 of the AMD to develop the Failure/Abort Sequence Trees (FASTs) and to determine the fuel releases (source terms) resulting from the potential Space Shuttle/IUS accidents throughout the missions.

  5. Laser power conversion system analysis, volume 1

    NASA Technical Reports Server (NTRS)

    Jones, W. S.; Morgan, L. L.; Forsyth, J. B.; Skratt, J. P.

    1979-01-01

    The orbit-to-orbit laser energy conversion system analysis established a mission model of satellites with various orbital parameters and average electrical power requirements ranging from 1 to 300 kW. The system analysis evaluated various conversion techniques, power system deployment parameters, power system electrical supplies and other critical supplies and other critical subsystems relative to various combinations of the mission model. The analysis show that the laser power system would not be competitive with current satellite power systems from weight, cost and development risk standpoints.

  6. Multi-level segment analysis: definition and application in turbulent systems

    NASA Astrophysics Data System (ADS)

    Wang, L. P.; Huang, Y. X.

    2015-06-01

    For many complex systems the interaction of different scales is among the most interesting and challenging features. It seems not very successful to extract the physical properties in different scale regimes by the existing approaches, such as the structure-function and Fourier spectrum method. Fundamentally, these methods have their respective limitations, for instance scale mixing, i.e. the so-called infrared and ultraviolet effects. To make improvements in this regard, a new method, multi-level segment analysis (MSA) based on the local extrema statistics, has been developed. Benchmark (fractional Brownian motion) verifications and the important case tests (Lagrangian and two-dimensional turbulence) show that MSA can successfully reveal different scaling regimes which have remained quite controversial in turbulence research. In general the MSA method proposed here can be applied to different dynamic systems in which the concepts of multiscale and multifractality are relevant.

  7. Online Kernel Slow Feature Analysis for Temporal Video Segmentation and Tracking.

    PubMed

    Liwicki, Stephan; Zafeiriou, Stefanos P; Pantic, Maja

    2015-10-01

    Slow feature analysis (SFA) is a dimensionality reduction technique which has been linked to how visual brain cells work. In recent years, the SFA was adopted for computer vision tasks. In this paper, we propose an exact kernel SFA (KSFA) framework for positive definite and indefinite kernels in Krein space. We then formulate an online KSFA which employs a reduced set expansion. Finally, by utilizing a special kind of kernel family, we formulate exact online KSFA for which no reduced set is required. We apply the proposed system to develop a SFA-based change detection algorithm for stream data. This framework is employed for temporal video segmentation and tracking. We test our setup on synthetic and real data streams. When combined with an online learning tracking system, the proposed change detection approach improves upon tracking setups that do not utilize change detection. PMID:25935036

  8. Automatic classification of segmented MRI data combining Independent Component Analysis and Support Vector Machines.

    PubMed

    Khedher, Laila; Ramírez, Javier; Górriz, Juan Manuel; Brahim, Abdelbasset

    2014-01-01

    This paper proposes a novel method for automatic classification of magnetic resonance images (MRI) based on independent component analysis (ICA). Our methodology consists of three processing steps. First, all the MRI scans are normalized and segmented into gray matter, white matter and cerebrospinal fluid. Then, ICA is applied to the preprocessed images for extracting relevant features which will be used as inputs to a support vector machine (SVM) classifier in order to reduce the feature space dimensionality. The system discriminates between Alzheimer's disease (AD) patients, mild cognitive impairment (MCI), and normal control (NC) subjects. All MRI data used in this work were obtained from the Alzheimers Disease Neuroimaging Initiative (ADNI). The experimental results showed that our methodology can successfully discriminate AD and MCI patients from NC subjects. PMID:25488233

  9. Segmentation of Three-dimensional Retinal Image Data

    Microsoft Academic Search

    Alfred R. Fuller; Robert J. Zawadzki; Stacey Choi; David F. Wiley; John S. Werner; Bernd Hamann

    2007-01-01

    We have combined methods from volume visualization and data analysis to support better diagnosis and treatment of human retinal diseases. Many diseases can be identified by abnormalities in the thicknesses of various retinal layers captured using optical coherence tomography (OCT). We used a support vector machine (SVM) to perform semi-automatic segmentation of retinal layers for subsequent analysis including a comparison

  10. Ultratrace LC-MS/MS analysis of segmented calf hair for retrospective assessment of time of clenbuterol administration in Agriforensics.

    PubMed

    Duvivier, Wilco F; van Beek, Teris A; Meijer, Thijs; Peeters, Ruth J P; Groot, Maria J; Sterk, Saskia S; Nielen, Michel W F

    2015-01-21

    In agriforensics, time of administration is often debated when illegal drug residues, such as clenbuterol, are found in frequently traded cattle. In this proof-of-concept work, the feasibility of obtaining retrospective timeline information from segmented calf tail hair analyses has been studied. First, an ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) hair analysis method was adapted to accommodate smaller sample sizes and in-house validated. Then, longitudinal 1 cm segments of calf tail hair were analyzed to obtain clenbuterol concentration profiles. The profiles found were in good agreement with calculated, theoretical positions of the clenbuterol residues along the hair. Following assessment of the average growth rate of calf tail hair, time of clenbuterol administration could be retrospectively determined from segmented hair analysis data. The data from the initial animal treatment study (n = 2) suggest that time of treatment can be retrospectively estimated with an error of 3-17 days. PMID:25537490

  11. Identifying Like-Minded Audiences for Global Warming Public Engagement Campaigns: An Audience Segmentation Analysis and Tool Development

    PubMed Central

    Maibach, Edward W.; Leiserowitz, Anthony; Roser-Renouf, Connie; Mertz, C. K.

    2011-01-01

    Background Achieving national reductions in greenhouse gas emissions will require public support for climate and energy policies and changes in population behaviors. Audience segmentation – a process of identifying coherent groups within a population – can be used to improve the effectiveness of public engagement campaigns. Methodology/Principal Findings In Fall 2008, we conducted a nationally representative survey of American adults (n?=?2,164) to identify audience segments for global warming public engagement campaigns. By subjecting multiple measures of global warming beliefs, behaviors, policy preferences, and issue engagement to latent class analysis, we identified six distinct segments ranging in size from 7 to 33% of the population. These six segments formed a continuum, from a segment of people who were highly worried, involved and supportive of policy responses (18%), to a segment of people who were completely unconcerned and strongly opposed to policy responses (7%). Three of the segments (totaling 70%) were to varying degrees concerned about global warming and supportive of policy responses, two (totaling 18%) were unsupportive, and one was largely disengaged (12%), having paid little attention to the issue. Certain behaviors and policy preferences varied greatly across these audiences, while others did not. Using discriminant analysis, we subsequently developed 36-item and 15-item instruments that can be used to categorize respondents with 91% and 84% accuracy, respectively. Conclusions/Significance In late 2008, Americans supported a broad range of policies and personal actions to reduce global warming, although there was wide variation among the six identified audiences. To enhance the impact of campaigns, government agencies, non-profit organizations, and businesses seeking to engage the public can selectively target one or more of these audiences rather than address an undifferentiated general population. Our screening instruments are available to assist in that process. PMID:21423743

  12. Segmentation with Area Constraints

    PubMed Central

    Niethammer, Marc; Zach, Christopher

    2012-01-01

    Image segmentation approaches typically incorporate weak regularity conditions such as boundary length or curvature terms, or use shape information. High-level information such as a desired area or volume, or a particular topology are only implicitly specified. In this paper we develop a segmentation method with explicit bounds on the segmented area. Area constraints allow for the soft selection of meaningful solutions, and can counteract the shrinking bias of length-based regularization. We analyze the intrinsic problems of convex relaxations proposed in the literature for segmentation with size constraints. Hence, we formulate the area-constrained segmentation task as a mixed integer program, propose a branch and bound method for exact minimization, and use convex relaxations to obtain the required lower energy bounds on candidate solutions. We also provide a numerical scheme to solve the convex subproblems. We demonstrate the method for segmentations of vesicles from electron tomography images. PMID:23084504

  13. Differential Gene Expression Profiling and Biological Process Analysis in Proximal Nerve Segments after Sciatic Nerve Transection

    PubMed Central

    Wang, Yongjun; Gu, Yun; Liu, Dong; Wang, Chunming; Ding, Guohui; Chen, Jianping; Liu, Jie; Gu, Xiaosong

    2013-01-01

    After traumatic injury, peripheral nerves can spontaneously regenerate through highly sophisticated and dynamic processes that are regulated by multiple cellular elements and molecular factors. Despite evidence of morphological changes and of expression changes of a few regulatory genes, global knowledge of gene expression changes and related biological processes during peripheral nerve injury and regeneration is still lacking. Here we aimed to profile global mRNA expression changes in proximal nerve segments of adult rats after sciatic nerve transection. According to DNA microarray analysis, the huge number of genes was differentially expressed at different time points (0.5 h–14 d) post nerve transection, exhibiting multiple distinct temporal expression patterns. The expression changes of several genes were further validated by quantitative real-time RT-PCR analysis. The gene ontology enrichment analysis was performed to decipher the biological processes involving the differentially expressed genes. Collectively, our results highlighted the dynamic change of the important biological processes and the time-dependent expression of key regulatory genes after peripheral nerve injury. Interestingly, we, for the first time, reported the presence of olfactory receptors in sciatic nerves. Hopefully, this study may provide a useful platform for deeply studying peripheral nerve injury and regeneration from a molecular-level perspective. PMID:23437294

  14. Comparison of functional thalamic segmentation from seed-based analysis and ICA.

    PubMed

    Hale, Joanne R; Mayhew, Stephen D; Mullinger, Karen J; Wilson, Rebecca S; Arvanitis, Theodoros N; Francis, Susan T; Bagshaw, Andrew P

    2015-07-01

    Information flow between the thalamus and cerebral cortex is a crucial component of adaptive brain function, but the details of thalamocortical interactions in human subjects remain unclear. The principal aim of this study was to evaluate the agreement between functional thalamic network patterns, derived using seed-based connectivity analysis and independent component analysis (ICA) applied separately to resting state functional MRI (fMRI) data from 21 healthy participants. For the seed-based analysis, functional thalamic parcellation was achieved by computing functional connectivity (FC) between thalamic voxels and a set of pre-defined cortical regions. Thalamus-constrained ICA provided an alternative parcellation. Both FC analyses demonstrated plausible and comparable group-level thalamic subdivisions, in agreement with previous work. Quantitative assessment of the spatial overlap between FC thalamic segmentations, and comparison of each to a histological "gold-standard" thalamic atlas and a structurally-defined thalamic atlas, highlighted variations between them and, most notably, differences with both histological and structural results. Whilst deeper understanding of thalamocortical connectivity rests upon identification of features common to multiple non-invasive neuroimaging techniques (e.g. FC, structural connectivity and anatomical localisation of individual-specific nuclei), this work sheds further light on the functional organisation of the thalamus and the varying sensitivities of complementary analyses to resolve it. PMID:25896929

  15. Beyond Corridor Reliability Measures: Analysis of Freeway Travel Time Reliability at the1 Segment Level for Hotspot Identification2

    E-print Network

    Bertini, Robert L.

    Beyond Corridor Reliability Measures: Analysis of Freeway Travel Time Reliability at the1 Segment and particularly1 freeways. However, it has become evident that travel time reliability, taking into account at the directional corridor level for planning4 purposes and analyze the ways in which travel time reliability can

  16. In vivo Observation of the Axial Movement of Intraocular Lenses through an Anterior Eye Segment Analysis System

    Microsoft Academic Search

    Hiroko Nakaizumi; Kazuyuki Sasaki; Yasuo Sakamoto

    1992-01-01

    The small axial movement of the anterior surface of implanted intraocular lenses (IOLs) were examined in pseudophakic eyes with one-piece and three-piece IOLs using an anterior eye segment analysis system. The movement was calculated as the distance between the posterior surface of the cornea and the anterior surface of an IOL under a normal pupil size, following the instillation of

  17. Bivariate segmentation of SNP-array data for allele-specific copy number analysis in tumour samples

    PubMed Central

    2013-01-01

    Background SNP arrays output two signals that reflect the total genomic copy number (LRR) and the allelic ratio (BAF), which in combination allow the characterisation of allele-specific copy numbers (ASCNs). While methods based on hidden Markov models (HMMs) have been extended from array comparative genomic hybridisation (aCGH) to jointly handle the two signals, only one method based on change-point detection, ASCAT, performs bivariate segmentation. Results In the present work, we introduce a generic framework for bivariate segmentation of SNP array data for ASCN analysis. For the matter, we discuss the characteristics of the typically applied BAF transformation and how they affect segmentation, introduce concepts of multivariate time series analysis that are of concern in this field and discuss the appropriate formulation of the problem. The framework is implemented in a method named CnaStruct, the bivariate form of the structural change model (SCM), which has been successfully applied to transcriptome mapping and aCGH. Conclusions On a comprehensive synthetic dataset, we show that CnaStruct outperforms the segmentation of existing ASCN analysis methods. Furthermore, CnaStruct can be integrated into the workflows of several ASCN analysis tools in order to improve their performance, specially on tumour samples highly contaminated by normal cells. PMID:23497144

  18. Spectral analysis program. Volume 1: User's guide

    NASA Technical Reports Server (NTRS)

    Hayden, W. L.

    1972-01-01

    The spectral analysis program (SAP) was developed to provide the Manned Spacecraft Center with the capability of computing the power spectrum of a phase or frequency modulated high frequency carrier wave. Previous power spectrum computational techniques were restricted to relatively simple modulating signals because of excessive computational time, even on a high speed digital computer. The present technique uses the recently developed extended fast Fourier transform and represents a generalized approach for simple and complex modulating signals. The present technique is especially convenient for implementation of a variety of low-pass filters for the modulating signal and bandpass filters for the modulated signal.

  19. Interactive 3D segmentation of the prostate in magnetic resonance images using shape and local appearance similarity analysis

    NASA Astrophysics Data System (ADS)

    Shahedi, Maysam; Fenster, Aaron; Cool, Derek W.; Romagnoli, Cesare; Ward, Aaron D.

    2013-03-01

    3D segmentation of the prostate in medical images is useful to prostate cancer diagnosis and therapy guidance, but is time-consuming to perform manually. Clinical translation of computer-assisted segmentation algorithms for this purpose requires a comprehensive and complementary set of evaluation metrics that are informative to the clinical end user. We have developed an interactive 3D prostate segmentation method for 1.5T and 3.0T T2-weighted magnetic resonance imaging (T2W MRI) acquired using an endorectal coil. We evaluated our method against manual segmentations of 36 3D images using complementary boundary-based (mean absolute distance; MAD), regional overlap (Dice similarity coefficient; DSC) and volume difference (?V) metrics. Our technique is based on inter-subject prostate shape and local boundary appearance similarity. In the training phase, we calculated a point distribution model (PDM) and a set of local mean intensity patches centered on the prostate border to capture shape and appearance variability. To segment an unseen image, we defined a set of rays - one corresponding to each of the mean intensity patches computed in training - emanating from the prostate centre. We used a radial-based search strategy and translated each mean intensity patch along its corresponding ray, selecting as a candidate the boundary point with the highest normalized cross correlation along each ray. These boundary points were then regularized using the PDM. For the whole gland, we measured a mean+/-std MAD of 2.5+/-0.7 mm, DSC of 80+/-4%, and ?V of 1.1+/-8.8 cc. We also provided an anatomic breakdown of these metrics within the prostatic base, mid-gland, and apex.

  20. Automated segmentation of free-lying cell nuclei in Pap smears for malignancy-associated change analysis.

    PubMed

    Moshavegh, Ramin; Ehteshami Bejnordi, Babak; Mehnert, Andrew; Sujathan, K; Malm, Patrik; Bengtsson, Ewert

    2012-01-01

    This paper presents an automated algorithm for robustly detecting and segmenting free-lying cell nuclei in bright-field microscope images of Pap smears. This is an essential initial step in the development of an automated screening system for cervical cancer based on malignancy associated change (MAC) analysis. The proposed segmentation algorithm makes use of gray-scale annular closings to identify free-lying nuclei-like objects together with marker-based watershed segmentation to accurately delineate the nuclear boundaries. The algorithm also employs artifact rejection based on size, shape, and granularity to ensure only the nuclei of intermediate squamous epithelial cells are retained. An evaluation of the performance of the algorithm relative to expert manual segmentation of 33 fields-of-view from 11 Pap smear slides is also presented. The results show that the sensitivity and specificity of nucleus detection is 94.71% and 85.30% respectively, and that the accuracy of segmentation, measured using the Dice coefficient, of the detected nuclei is 97.30±1.3%. PMID:23367143

  1. Analysis of in vivo DNA repair rates of alkylpurines in defined segments of human DNA

    SciTech Connect

    Wright, P.W.; Weiss, R.B.; Gallagher, P.E. (West Virginia Univ., Morgantown (United States))

    1991-03-11

    Simple alkylating agents, such as methyl methanesulfonate or dimethyl sulfate, react with DNA bases to yield 7-methylguanine as the major product, with 3-methyladenine and O{sup 6}-methylguanine in lesser amounts. It has been shown that these alkylated bases are actively repaired in vivo in both bacteria and mammalian cells. The authors have employed a polymerase chain reaction assay to examine the in vivo formation and repair rates of alkylpurines in a defined segment of the human dihydrofolate reductase gene. Human lymphoblasts were treated with varying doses of dimethyl sulfate and a limiting concentration of the isolated DNA was used in the amplification reactions. Alkylation resulted in a dose-dependent loss of primer extension, presumably due to 3-methyladenine blockage of the Taq polymerase. Analysis of the amplified reaction products by radioautography following polyacrylamide gel electrophoresis showed that the prematurely truncated amplified products terminated at adenines as compared to DNA sequencing fragments. Heat treatment of the amplified DNAs prior to gel analysis resulted in fragments that terminated at adenines and guanines. The lymphoblast DNA was isolated at various times after alkylation and the repair rate of alkyladenine in the DHFR fragment was found to be more efficient than that of the overall genome.

  2. Microfluidic Chip for High Efficiency Electrophoretic Analysis of Segmented Flow from a Microdialysis Probe and in Vivo Chemical Monitoring

    PubMed Central

    Wang, Meng; Roman, Gregory T.; Perry, Maura L.; Kennedy, Robert T.

    2009-01-01

    An effective method for in vivo chemical monitoring is to couple sampling probes, such as microdialysis, to on-line analytical methods. A limitation of this approach is that in vivo chemical dynamics may be distorted by flow and diffusion broadening during transfer from sampling probe to analytical system. Converting a homogenous sample stream to segmented flow can prevent such broadening. We have developed a system for coupling segmented microdialysis flow with chip-based electrophoresis. In this system, the dialysis probe is integrated with a PDMS chip that merges dialysate with fluorogenic reagent and segments the flow into 8–10 nL plugs at 0.3–0.5 Hz separated by perfluorodecalin. The plugs flow to a glass chip where they are extracted to an aqueous stream and analyzed by electrophoresis with fluorescence detection. The novel extraction system connects the segmented flow to an electrophoresis sampling channel by a shallow and hydrophilic extraction bridge that removes the entire aqueous droplet from the oil stream. With this approach, temporal resolution was 35 s and independent of distance between sampling and analysis. Electrophoretic analysis produced separation with 223,000 ± 21,000 theoretical plates, 4.4% RSD in peak height, and detection limits of 90–180 nM for six amino acids. This performance was made possible by three key elements: 1) reliable transfer of plug flow to a glass chip; 2) efficient extraction of aqueous plugs from segmented flow; and 3) electrophoretic injection suitable for high efficiency separation with minimal dilution of sample. The system was used to detect rapid concentration changes evoked by infusing glutamate uptake inhibitor into the striatum of anesthetized rats. These results demonstrate the potential of incorporating segmented flow into separations-based sensing schemes for studying chemical dynamics in vivo with improved temporal resolution. PMID:19803495

  3. Semi-automatic segmentation and modeling of the cervical spinal cord for volume quantification in multiple sclerosis patients from magnetic resonance images

    NASA Astrophysics Data System (ADS)

    Sonkova, Pavlina; Evangelou, Iordanis E.; Gallo, Antonio; Cantor, Fredric K.; Ohayon, Joan; McFarland, Henry F.; Bagnato, Francesca

    2008-03-01

    Spinal cord (SC) tissue loss is known to occur in some patients with multiple sclerosis (MS), resulting in SC atrophy. Currently, no measurement tools exist to determine the magnitude of SC atrophy from Magnetic Resonance Images (MRI). We have developed and implemented a novel semi-automatic method for quantifying the cervical SC volume (CSCV) from Magnetic Resonance Images (MRI) based on level sets. The image dataset consisted of SC MRI exams obtained at 1.5 Tesla from 12 MS patients (10 relapsing-remitting and 2 secondary progressive) and 12 age- and gender-matched healthy volunteers (HVs). 3D high resolution image data were acquired using an IR-FSPGR sequence acquired in the sagittal plane. The mid-sagittal slice (MSS) was automatically located based on the entropy calculation for each of the consecutive sagittal slices. The image data were then pre-processed by 3D anisotropic diffusion filtering for noise reduction and edge enhancement before segmentation with a level set formulation which did not require re-initialization. The developed method was tested against manual segmentation (considered ground truth) and intra-observer and inter-observer variability were evaluated.

  4. Unconventional Word Segmentation in Emerging Bilingual Students' Writing: A Longitudinal Analysis

    ERIC Educational Resources Information Center

    Sparrow, Wendy

    2014-01-01

    This study explores cross-language and longitudinal patterns in unconventional word segmentation in 25 emerging bilingual students' (Spanish/English) writing from first through third grade. Spanish and English writing samples were collected annually and analyzed for two basic types of unconventional word segmentation: hyposegmentation, in…

  5. Cell lineage analysis of pattern formation in the Tubifex embryo. I. Segmentation in the mesoderm.

    PubMed

    Goto, A; Kitamura, K; Shimizu, T

    1999-07-01

    Annelids are strongly segmented animals that display a high degree of metamerism in their body plan. The embryonic origin of metameric segmentation was examined in an oligochaete annelid Tubifex using lineage tracers. Segmental organization arises sequentially in the anterior-to-posterior direction along the longitudinal axis of the mesodermal germ band, a coherent column of primary blast cells that are produced from the mesodermal teloblast. Shortly after its birth, each primary blast cell undergoes a spatiotemporally stereotyped sequence of cell divisions to generate three classes of cells (in terms of cell size), which together give rise to a distinct cell cluster. Each cluster is composed of descendants of a single primary blast cell; there is no intermingling of cells between adjacent clusters. Relatively small-sized cells in each cluster become localized at its periphery, and they form coelomic walls including an intersegmental septum to establish individuality of segments. A set of cell ablation experiments showed that these features of mesodermal segmentation are not affected by the absence of the overlying ectodermal germ band. These results suggest that each primary blast cell serves as a founder cell of each mesodermal segment and that the boundary between segments is determined autonomously. It is concluded that the metameric body plan of Tubifex arises from an initially simple organization (i.e., a linear series) of segmental founder cells. PMID:10470648

  6. An Automatic Segmentation Combining Mixture Analysis and Adaptive Region Information: A Level Set Approach

    Microsoft Academic Search

    Mohand Saïd Allili; Djemel Ziou

    2005-01-01

    In this paper, we propose a novel automatic framework for variational color image segmentation based on unifying adaptive region information and mixture modelling. We consider a formulation of the region information by using the posterior probability of a mixture of general Gaussian (GG) pdfs, where each region is represented by a pdf. The segmentation is formulated by the minimization of

  7. Segmentation, reconstruction, and analysis of blood thrombi in 2-photon microscopy images

    Microsoft Academic Search

    Jian Mu; Xiaomin Liu; Malgorzata M. Kamocka; Zhiliang Xu; Mark S. Alber; Elliot D. Rosen; Danny Z. Chen

    2009-01-01

    In this paper, we study the problem of segmenting, reconstructing, and analyzing the structure and growth of thrombi (clots) in vivo in blood vessels based on 2-photon microscopic image data. First, we develop an algorithm for segmenting clots in 3-D microscopic images which incorporates the density-based clustering algorithm and other methods for dealing with imaging artifacts. Next, we apply the

  8. Captured Human Motion Segmentation Based on Dynamics and Principal Component Analysis

    Microsoft Academic Search

    Jing Shu-xu; Yuan Qi

    2009-01-01

    This paper proposes an approach for segmenting single actions from continuously captured motion sequences by examining the properties of active limbs. The target motions are related to sporting and dancing. In particular, two types of human sports motions are examined: 1) boxing and 2) hip hop dance. To segment continuous boxing motion sequences into single punches and combo punches, this

  9. Automated 3D Segmentation of Intraretinal Surfaces in SD-OCT Volumes in Normal and Diabetic Mice

    PubMed Central

    Antony, Bhavna J.; Jeong, Woojin; Abràmoff, Michael D.; Vance, Joseph; Sohn, Elliott H.; Garvin, Mona K.

    2014-01-01

    Purpose To describe an adaptation of an existing graph-theoretic method (initially developed for human optical coherence tomography [OCT] images) for the three-dimensional (3D) automated segmentation of 10 intraretinal surfaces in mice scans, and assess the accuracy of the method and the reproducibility of thickness measurements. Methods Ten intraretinal surfaces were segmented in repeat spectral domain (SD)-OCT volumetric images acquired from normal (n = 8) and diabetic (n = 10) mice. The accuracy of the method was assessed by computing the border position errors of the automated segmentation with respect to manual tracings obtained from two experts. The reproducibility was statistically assessed for four retinal layers within eight predefined regions using the mean and SD of the differences in retinal thickness measured in the repeat scans, the coefficient of variation (CV) and the intraclass correlation coefficients (ICC; with 95% confidence intervals [CIs]). Results The overall mean unsigned border position error for the 10 surfaces computed over 97 B-scans (10 scans, 10 normal mice) was 3.16 ± 0.91 ?m. The overall mean differences in retinal thicknesses computed from the normal and diabetic mice were 1.86 ± 0.95 and 2.15 ± 0.86 ?m, respectively. The CV of the retinal thicknesses for all the measured layers ranged from 1.04% to 5%. The ICCs for the total retinal thickness in the normal and diabetic mice were 0.78 [0.10, 0.92] and 0.83 [0.31, 0.96], respectively. Conclusion The presented method (publicly available as part of the Iowa Reference Algorithms) has acceptable accuracy and reproducibility and is expected to be useful in the quantitative study of intraretinal layers in mice. Translational Relevance The presented method, initially developed for human OCT, has been adapted for mice, with the potential to be adapted for other animals as well. Quantitative in vivo assessment of the retina in mice allows changes to be measured longitudinally, decreasing the need for them. PMID:25346873

  10. Breast cancer risk analysis based on a novel segmentation framework for digital mammograms.

    PubMed

    Chen, Xin; Moschidis, Emmanouil; Taylor, Chris; Astley, Susan

    2014-01-01

    The radiographic appearance of breast tissue has been established as a strong risk factor for breast cancer. Here we present a complete machine learning framework for automatic estimation of mammographic density (MD) and robust feature extraction for breast cancer risk analysis. Our framework is able to simultaneously classify the breast region, fatty tissue, pectoral muscle, glandular tissue and nipple region. Integral to our method is the extraction of measures of breast density (as the fraction of the breast area occupied by glandular tissue) and mammographic pattern. A novel aspect of the segmentation framework is that a probability map associated with the label mask is provided, which indicates the level of confidence of each pixel being classified as the current label. The Pearson correlation coefficient between the estimated MD value and the ground truth is 0.8012 (p-value < 0.0001). We demonstrate the capability of our methods to discriminate between women with and without cancer by analyzing the contralateral mammograms of 50 women with unilateral breast cancer, and 50 controls. Using MD we obtained an area under the ROC curve (AUC) of 0.61; however our texture-based measure of mammographic pattern significantly outperforms the MD discrimination with an AUC of 0.70. PMID:25333160

  11. Accuracy of segmental bioelectrical impedance analysis for predicting body composition in pre- and postmenopausal women.

    PubMed

    Tanaka, Noriko I; Hanawa, Satoshi; Murakami, Haruka; Cao, Zhen-Bo; Tanimoto, Michiya; Sanada, Kiyoshi; Miyachi, Motohiko

    2015-04-01

    This study aimed to compare the accuracy for predicting body composition using single-frequent segmental bioelectrical impedance analysis (BIA) between pre- and postmenopausal women. A total f 559 Japanese women aged 30-88yr were divided into 4 groups by questionnaire: natural menopause, pathological menopause, regular menstruation, or irregular menstruation. The measurement values by dual-energy X-ray absorptiometry were used as a reference of the body composition. In terms of the results, regardless of the menopausal status, BIA slightly but significantly overestimated the percentage of body fat (standard error of estimate: 5.3%-6.7%) and the leg lean soft tissue mass (LSTM; 5.1%-6.1%), and underestimated the LSTM in the whole body (6.2%-7.6%) and arm (2.8%-3.7%). The absolute values of the predictive error for leg LSTM were significantly higher in postmenopausal groups than in the premenopausal ones. The corresponding values for the whole body and arm LSTM, and the percentage of body fat were higher in premenopausal groups than in postmenopausal ones. In conclusion, the predictive accuracy of BIA for postmenopausal women is not inferior to that for premenopausal ones, unless we target the leg LSTM. PMID:25174687

  12. Segmented independent component analysis for improved separation of fetal cardiac signals from nonstationary fetal magnetocardiograms.

    PubMed

    Murta, Luiz O; Guzo, Mauro G; Moraes, Eder R; Baffa, Oswaldo; Wakai, Ronald T; Comani, Silvia

    2015-06-01

    Fetal magnetocardiograms (fMCGs) have been successfully processed with independent component analysis (ICA) to separate the fetal cardiac signals, but ICA effectiveness can be limited by signal nonstationarities due to fetal movements. We propose an ICA-based method to improve the quality of fetal signals separated from fMCG affected by fetal movements. This technique (SegICA) includes a procedure to detect signal nonstationarities, according to which the fMCG recordings are divided in stationary segments that are then processed with ICA. The first and second statistical moments and the signal polarity reversal were used at different threshold levels to detect signal transients. SegICA effectiveness was assessed in two fMCG datasets (with and without fetal movements) by comparing the signal-to-noise ratio (SNR) of the signals extracted with ICA and with SegICA. Results showed that the SNR of fetal signals affected by fetal movements improved with SegICA, whereas the SNR gain was negligible elsewhere. The best measure to detect signal nonstationarities of physiological origin was signal polarity reversal at threshold level 0.9. The first statistical moment also provided good results at threshold level 0.6. SegICA seems a promising method to separate fetal cardiac signals of improved quality from nonstationary fMCG recordings affected by fetal movements. PMID:25781658

  13. Pairwise shared genomic segment analysis in three Utah high-risk breast cancer pedigrees

    PubMed Central

    2012-01-01

    Background We applied a new weighted pairwise shared genomic segment (pSGS) analysis for susceptibility gene localization to high-density genomewide SNP data in three extended high-risk breast cancer pedigrees. Results Using this method, four genomewide suggestive regions were identified on chromosomes 2, 4, 7 and 8, and a borderline suggestive region on chromosome 14. Seven additional regions with at least nominal evidence were observed. Of particular note among these total twelve regions were three regions that were identified in two pedigrees each; chromosomes 4, 7 and 14. Follow-up two-pedigree pSGS analyses further indicated excessive genomic sharing across the pedigrees in all three regions, suggesting that the underlying susceptibility alleles in those regions may be shared in common. In general, the pSGS regions identified were quite large (average 32.2 Mb), however, the range was wide (0.3 – 88.2 Mb). Several of the regions identified overlapped with loci and genes that have been previously implicated in breast cancer risk, including NBS1, BRCA1 and RAD51L1. Conclusions Our analyses have provided several loci of interest to pursue in these high-risk pedigrees and illustrate the utility of the weighted pSGS method and extended pedigrees for gene mapping in complex diseases. A focused sequencing effort across these loci in the sharing individuals is the natural next step to further map the critical underlying susceptibility variants in these regions. PMID:23190577

  14. Analysis of fluctuations in the cGMP-dependent currents of cone photoreceptor outer segments.

    PubMed Central

    Picones, A; Korenbrot, J I

    1994-01-01

    We measured cGMP-dependent currents, under voltage clamp, in membrane patches detached from the outer segment of single-cone photoreceptors isolated from the retina of striped bass. We analyzed the variance of the current about its mean and the spectral density distribution of the current fluctuations. From the analysis of variance, we determined that the cGMP-gated channels increase their probability of opening with increasing cGMP up to a maximum value of 0.87 +/- 0.03. The dependence on cGMP of the probability of opening is well described by a Hill equation with Km = 60.2 +/- 3.7 microM and n = 2.33 +/- 0.32 at -50 mV. At the same voltage, the spectral density distribution is well fit by the sum of two Lorentzians with corner frequencies at 26 +/- 18 and 318 +/- 58 Hz. The single-channel conductance calculated from the current noise by two different methods suggests that the most frequently occupied conductance state has an amplitude of about 18 pS. PMID:8161689

  15. Magnetic field analysis of Lorentz motors using a novel segmented magnetic equivalent circuit method.

    PubMed

    Qian, Junbing; Chen, Xuedong; Chen, Han; Zeng, Lizhan; Li, Xiaoqing

    2013-01-01

    A simple and accurate method based on the magnetic equivalent circuit (MEC) model is proposed in this paper to predict magnetic flux density (MFD) distribution of the air-gap in a Lorentz motor (LM). In conventional MEC methods, the permanent magnet (PM) is treated as one common source and all branches of MEC are coupled together to become a MEC network. In our proposed method, every PM flux source is divided into three sub-sections (the outer, the middle and the inner). Thus, the MEC of LM is divided correspondingly into three independent sub-loops. As the size of the middle sub-MEC is small enough, it can be treated as an ideal MEC and solved accurately. Combining with decoupled analysis of outer and inner MECs, MFD distribution in the air-gap can be approximated by a quadratic curve, and the complex calculation of reluctances in MECs can be avoided. The segmented magnetic equivalent circuit (SMEC) method is used to analyze a LM, and its effectiveness is demonstrated by comparison with FEA, conventional MEC and experimental results. PMID:23358368

  16. Contact-free determination of human body segment parameters by means of videometric image processing of an anthropomorphic body model

    Microsoft Academic Search

    Herbert Hatze; Arnold Baca

    1993-01-01

    The development of noninvasive techniques for the determination of biomechanical body segment parameters (volumes, masses, the three principal moments of inertia, the three local coordinates of the segmental mass centers, etc.) receives increasing attention from the medical sciences (e,.g., orthopaedic gait analysis), bioengineering, sport biomechanics, and the various space programs. In the present paper, a novel method is presented for

  17. Automated Forensic Animal Family Identification by Nested PCR and Melt Curve Analysis on an Off-the-Shelf Thermocycler Augmented with a Centrifugal Microfluidic Disk Segment

    PubMed Central

    Zengerle, Roland; von Stetten, Felix; Schmidt, Ulrike

    2015-01-01

    Nested PCR remains a labor-intensive and error-prone biomolecular analysis. Laboratory workflow automation by precise control of minute liquid volumes in centrifugal microfluidic Lab-on-a-Chip systems holds great potential for such applications. However, the majority of these systems require costly custom-made processing devices. Our idea is to augment a standard laboratory device, here a centrifugal real-time PCR thermocycler, with inbuilt liquid handling capabilities for automation. We have developed a microfluidic disk segment enabling an automated nested real-time PCR assay for identification of common European animal groups adapted to forensic standards. For the first time we utilize a novel combination of fluidic elements, including pre-storage of reagents, to automate the assay at constant rotational frequency of an off-the-shelf thermocycler. It provides a universal duplex pre-amplification of short fragments of the mitochondrial 12S rRNA and cytochrome b genes, animal-group-specific main-amplifications, and melting curve analysis for differentiation. The system was characterized with respect to assay sensitivity, specificity, risk of cross-contamination, and detection of minor components in mixtures. 92.2% of the performed tests were recognized as fluidically failure-free sample handling and used for evaluation. Altogether, augmentation of the standard real-time thermocycler with a self-contained centrifugal microfluidic disk segment resulted in an accelerated and automated analysis reducing hands-on time, and circumventing the risk of contamination associated with regular nested PCR protocols. PMID:26147196

  18. Synthesis and Analysis of Data. Volume II. Corpsmember Training Institute. Teacher Corps 1977.

    ERIC Educational Resources Information Center

    Houston, Robert; And Others

    This document is primarily intended as a companion piece to Volume I, which is entitled Description of CMTI. The first volume is, essentially, a description of the 1977 Teacher Corpsmember Training Institute, while the second volume is an analysis of the data contained in the first document. Volume Two is divided into four parts. Chapter One is a…

  19. Segmental Quantitative MR Imaging Analysis of Diurnal Variation of Water Content in the Lumbar Intervertebral Discs

    PubMed Central

    Zhu, Tingting; Ai, Tao; Zhang, Wei; Li, Tao

    2015-01-01

    Objective To investigate the changes in water content in the lumbar intervertebral discs by quantitative T2 MR imaging in the morning after bed rest and evening after a diurnal load. Materials and Methods Twenty healthy volunteers were separately examined in the morning after bed rest and in the evening after finishing daily work. T2-mapping images were obtained and analyzed. An equally-sized rectangular region of interest (ROI) was manually placed in both, the anterior and the posterior annulus fibrosus (AF), in the outermost 20% of the disc. Three ROIs were placed in the space defined as the nucleus pulposus (NP). Repeated-measures analysis of variance and paired 2-tailed t tests were used for statistical analysis, with p < 0.05 as significantly different. Results T2 values significantly decreased from morning to evening, in the NP (anterior NP = -13.9 ms; central NP = -17.0 ms; posterior NP = -13.3 ms; all p < 0.001). Meanwhile T2 values significantly increased in the anterior AF (+2.9 ms; p = 0.025) and the posterior AF (+5.9 ms; p < 0.001). T2 values in the posterior AF showed the largest degree of variation among the 5 ROIs, but there was no statistical significance (p = 0.414). Discs with initially low T2 values in the center NP showed a smaller degree of variation in the anterior NP and in the central NP, than in discs with initially high T2 values in the center NP (10.0% vs. 16.1%, p = 0.037; 6.4% vs. 16.1%, p = 0.006, respectively). Conclusion Segmental quantitative T2 MRI provides valuable insights into physiological aspects of normal discs. PMID:25598682

  20. A cautionary analysis of STAPLE using direct inference of segmentation truth.

    PubMed

    Van Leemput, Koen; Sabuncu, Mert R

    2014-01-01

    In this paper we analyze the properties of the well-known segmentation fusion algorithm STAPLE, using a novel inference technique that analytically marginalizes out all model parameters. We demonstrate both theoretically and empirically that when the number of raters is large, or when consensus regions are included in the model, STAPLE devolves into thresholding the average of the input segmentations. We further show that when the number of raters is small, the STAPLE result may not be the optimal segmentation truth estimate, and its model parameter estimates might not reflect the individual raters' actual segmentation performance. Our experiments indicate that these intrinsic weaknesses are frequently exacerbated by the presence of undesirable global optima and convergence issues. Together these results cast doubt on the soundness and usefulness of typical STAPLE outcomes. PMID:25333143

  1. Comparative analysis of operational forecasts versus actual weather conditions in airline flight planning, volume 4

    NASA Technical Reports Server (NTRS)

    Keitz, J. F.

    1982-01-01

    The impact of more timely and accurate weather data on airline flight planning with the emphasis on fuel savings is studied. This volume of the report discusses the results of Task 4 of the four major tasks included in the study. Task 4 uses flight plan segment wind and temperature differences as indicators of dates and geographic areas for which significant forecast errors may have occurred. An in-depth analysis is then conducted for the days identified. The analysis show that significant errors occur in the operational forecast on 15 of the 33 arbitrarily selected days included in the study. Wind speeds in an area of maximum winds are underestimated by at least 20 to 25 kts. on 14 of these days. The analysis also show that there is a tendency to repeat the same forecast errors from prog to prog. Also, some perceived forecast errors from the flight plan comparisons could not be verified by visual inspection of the corresponding National Meteorological Center forecast and analyses charts, and it is likely that they are the result of weather data interpolation techniques or some other data processing procedure in the airlines' flight planning systems.

  2. Liver segmentation in contrast enhanced CT data using graph cuts and interactive 3D segmentation refinement methods

    SciTech Connect

    Beichel, Reinhard; Bornik, Alexander; Bauer, Christian; Sorantin, Erich [Departments of Electrical and Computer Engineering and Internal Medicine, Iowa Institute for Biomedical Imaging, University of Iowa, Iowa City, Iowa 52242 (United States); Institute for Computer Graphics and Vision, Graz University of Technology, Inffeldgasse 16, A-8010 Graz (Austria); Department of Electrical and Computer Engineering, Iowa Institute for Biomedical Imaging, University of Iowa, Iowa City, Iowa 52242 (United States); Department of Radiology, Medical University Graz, Auenbruggerplatz 34, A-8010 Graz (Austria)

    2012-03-15

    Purpose: Liver segmentation is an important prerequisite for the assessment of liver cancer treatment options like tumor resection, image-guided radiation therapy (IGRT), radiofrequency ablation, etc. The purpose of this work was to evaluate a new approach for liver segmentation. Methods: A graph cuts segmentation method was combined with a three-dimensional virtual reality based segmentation refinement approach. The developed interactive segmentation system allowed the user to manipulate volume chunks and/or surfaces instead of 2D contours in cross-sectional images (i.e, slice-by-slice). The method was evaluated on twenty routinely acquired portal-phase contrast enhanced multislice computed tomography (CT) data sets. An independent reference was generated by utilizing a currently clinically utilized slice-by-slice segmentation method. After 1 h of introduction to the developed segmentation system, three experts were asked to segment all twenty data sets with the proposed method. Results: Compared to the independent standard, the relative volumetric segmentation overlap error averaged over all three experts and all twenty data sets was 3.74%. Liver segmentation required on average 16 min of user interaction per case. The calculated relative volumetric overlap errors were not found to be significantly different [analysis of variance (ANOVA) test, p = 0.82] between experts who utilized the proposed 3D system. In contrast, the time required by each expert for segmentation was found to be significantly different (ANOVA test, p = 0.0009). Major differences between generated segmentations and independent references were observed in areas were vessels enter or leave the liver and no accepted criteria for defining liver boundaries exist. In comparison, slice-by-slice based generation of the independent standard utilizing a live wire tool took 70.1 min on average. A standard 2D segmentation refinement approach applied to all twenty data sets required on average 38.2 min of user interaction and resulted in statistically not significantly different segmentation error indices (ANOVA test, significance level of 0.05). Conclusions: All three experts were able to produce liver segmentations with low error rates. User interaction time savings of up to 71% compared to a 2D refinement approach demonstrate the utility and potential of our approach. The system offers a range of different tools to manipulate segmentation results, and some users might benefit from a longer learning phase to develop efficient segmentation refinement strategies. The presented approach represents a generally applicable segmentation approach that can be applied to many medical image segmentation problems.

  3. Volume analysis of heat-induced cracks in human molars: A preliminary study

    PubMed Central

    Sandholzer, Michael A.; Baron, Katharina; Heimel, Patrick; Metscher, Brian D.

    2014-01-01

    Context: Only a few methods have been published dealing with the visualization of heat-induced cracks inside bones and teeth. Aims: As a novel approach this study used nondestructive X-ray microtomography (micro-CT) for volume analysis of heat-induced cracks to observe the reaction of human molars to various levels of thermal stress. Materials and Methods: Eighteen clinically extracted third molars were rehydrated and burned under controlled temperatures (400, 650, and 800°C) using an electric furnace adjusted with a 25°C increase/min. The subsequent high-resolution scans (voxel-size 17.7 ?m) were made with a compact micro-CT scanner (SkyScan 1174). In total, 14 scans were automatically segmented with Definiens XD Developer 1.2 and three-dimensional (3D) models were computed with Visage Imaging Amira 5.2.2. The results of the automated segmentation were analyzed with an analysis of variance (ANOVA) and uncorrected post hoc least significant difference (LSD) tests using Statistical Package for Social Sciences (SPSS) 17. A probability level of P < 0.05 was used as an index of statistical significance. Results: A temperature-dependent increase of heat-induced cracks was observed between the three temperature groups (P < 0.05, ANOVA post hoc LSD). In addition, the distributions and shape of the heat-induced changes could be classified using the computed 3D models. Conclusion: The macroscopic heat-induced changes observed in this preliminary study correspond with previous observations of unrestored human teeth, yet the current observations also take into account the entire microscopic 3D expansions of heat-induced cracks within the dental hard tissues. Using the same experimental conditions proposed in the literature, this study confirms previous results, adds new observations, and offers new perspectives in the investigation of forensic evidence. PMID:25125923

  4. Wireless capsule endoscopy video segmentation using an unsupervised learning approach based on probabilistic latent semantic analysis with scale invariant features.

    PubMed

    Shen, Yao; Guturu, Parthasarathy Partha; Buckles, Bill P

    2012-01-01

    Since wireless capsule endoscopy (WCE) is a novel technology for recording the videos of the digestive tract of a patient, the problem of segmenting the WCE video of the digestive tract into subvideos corresponding to the entrance, stomach, small intestine, and large intestine regions is not well addressed in the literature. A selected few papers addressing this problem follow supervised leaning approaches that presume availability of a large database of correctly labeled training samples. Considering the difficulties in procuring sizable WCE training data sets needed for achieving high classification accuracy, we introduce in this paper an unsupervised learning approach that employs Scale Invariant Feature Transform (SIFT) for extraction of local image features and the probabilistic latent semantic analysis (pLSA) model used in the linguistic content analysis for data clustering. Results of experimentation indicate that this method compares well in classification accuracy with the state-of-the-art supervised classification approaches to WCE video segmentation. PMID:22010158

  5. Ascending Direction: East Segment Code and Milepost: 003200 000.560 200 Feet West of Yellowstone Ave, Pocatello (Maple Street) Volumes and Percent of Daily Traffic

    Microsoft Academic Search

    Sunday Monday

    2009-01-01

    Hour Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day 0:00 26 1.6% 14 0.3% 15 0.4% 14 0.3% 23 0.6% 16 0.4% 25 0.9% 16 0.4% 26 1.2%

  6. Airway segmentation and analysis for the study of mouse models of lung disease using micro-CT

    NASA Astrophysics Data System (ADS)

    Artaechevarria, X.; Pérez-Martín, D.; Ceresa, M.; de Biurrun, G.; Blanco, D.; Montuenga, L. M.; van Ginneken, B.; Ortiz-de-Solorzano, C.; Muñoz-Barrutia, A.

    2009-11-01

    Animal models of lung disease are gaining importance in understanding the underlying mechanisms of diseases such as emphysema and lung cancer. Micro-CT allows in vivo imaging of these models, thus permitting the study of the progression of the disease or the effect of therapeutic drugs in longitudinal studies. Automated analysis of micro-CT images can be helpful to understand the physiology of diseased lungs, especially when combined with measurements of respiratory system input impedance. In this work, we present a fast and robust murine airway segmentation and reconstruction algorithm. The algorithm is based on a propagating fast marching wavefront that, as it grows, divides the tree into segments. We devised a number of specific rules to guarantee that the front propagates only inside the airways and to avoid leaking into the parenchyma. The algorithm was tested on normal mice, a mouse model of chronic inflammation and a mouse model of emphysema. A comparison with manual segmentations of two independent observers shows that the specificity and sensitivity values of our method are comparable to the inter-observer variability, and radius measurements of the mainstem bronchi reveal significant differences between healthy and diseased mice. Combining measurements of the automatically segmented airways with the parameters of the constant phase model provides extra information on how disease affects lung function.

  7. Time-ART: a tool for segmenting and annotating multimedia data in early stages of exploratory analysis

    Microsoft Academic Search

    Yasuhiro Yamamoto; Atsushi Aoki; Kumiyo Nakakoji

    2001-01-01

    Time-ART is a tool that helps a user in conducting empirical multimedia(video\\/sound) data analysis as an exploratory iterative process. Time-ART helps a user in (1) identifying seemingly interesting parts, (2) annotating them both textually and visually by positioning them in a 2D space, and (3) producing a summary report. The system consists of Movie\\/SoundEditor to segment a part of a

  8. Biomechanical Analysis of Fusion Segment Rigidity Upon Stress at Both the Fusion and Adjacent Segments: A Comparison between Unilateral and Bilateral Pedicle Screw Fixation

    PubMed Central

    Kim, Ho-Joong; Kang, Kyoung-Tak; Chang, Bong-Soon; Lee, Choon-Ki; Kim, Jang-Woo

    2014-01-01

    Purpose The purpose of this study was to investigate the effects of unilateral pedicle screw fixation on the fusion segment and the superior adjacent segment after one segment lumbar fusion using validated finite element models. Materials and Methods Four L3-4 fusion models were simulated according to the extent of decompression and the method of pedicle screws fixation in L3-4 lumbar fusion. These models included hemi-laminectomy with bilateral pedicle screw fixation in the L3-4 segment (BF-HL model), total laminectomy with bilateral pedicle screw fixation (BF-TL model), hemi-laminectomy with unilateral pedicle screw fixation (UF-HL model), and total laminectomy with unilateral pedicle screw fixation (UF-TL model). In each scenario, intradiscal pressures, annulus stress, and range of motion at the L2-3 and L3-4 segments were analyzed under flexion, extension, lateral bending, and torsional moments. Results Under four pure moments, the unilateral fixation leads to a reduction in increment of range of motion at the adjacent segment, but larger motions were noted at the fusion segment (L3-4) in the unilateral fixation (UF-HL and UF-TL) models when compared to bilateral fixation. The maximal von Mises stress showed similar patterns to range of motion at both superior adjacent L2-3 segments and fusion segment. Conclusion The current study suggests that unilateral pedicle screw fixation seems to be unable to afford sufficient biomechanical stability in case of bilateral total laminectomy. Conversely, in the case of hemi-laminectomy, unilateral fixation could be an alternative option, which also has potential benefit to reduce the stress of the adjacent segment. PMID:25048501

  9. Standard guide for measuring the wear volumes of piston ring segments run against flat coupons in reciprocating wear tests

    E-print Network

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 This guide covers and describes a profiling method for use accurately measuring the wear loss of compound-curved (crowned) piston ring specimens that run against flat counterfaces. It does not assume that the wear scars are ideally flat, as do some alternative measurement methods. Laboratory-scale wear tests have been used to evaluate the wear of materials, coatings, and surface treatments that are candidates for piston rings and cylinder liners in diesel engines or spark ignition engines. Various loads, temperatures, speeds, lubricants, and durations are used for such tests, but some of them use a curved piston ring segment as one sliding partner and a flat or curved specimen (simulating the cylinder liner) as its counterface. The goal of this guide is to provide more accurate wear measurements than alternative approaches involving weight loss or simply measuring the length and width of the wear marks. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its ...

  10. An automatic brain tumor segmentation tool.

    PubMed

    Diaz, Idanis; Boulanger, Pierre; Greiner, Russell; Hoehn, Bret; Rowe, Lindsay; Murtha, Albert

    2013-01-01

    This paper introduces an automatic brain tumor segmentation method (ABTS) for segmenting multiple components of brain tumor using four magnetic resonance image modalities. ABTS's four stages involve automatic histogram multi-thresholding and morphological operations including geodesic dilation. Our empirical results, on 16 real tumors, show that ABTS works very effectively, achieving a Dice accuracy compared to expert segmentation of 81% in segmenting edema and 85% in segmenting gross tumor volume (GTV). PMID:24110443

  11. Probabilities for jumping fault segment stepovers

    Microsoft Academic Search

    Bruce E. Shaw; James H. Dieterich

    2007-01-01

    Seismic hazard analysis relies heavily on the segmentation of faults. The ability of ruptures to break multiple segments has a big impact on estimated hazard. Current practice for estimating multiple segment breakage relies on panels of experts voting on their opinions for each case. Here, we explore the probability of elastodynamic ruptures jumping segment stepovers in numerical simulations of segmented

  12. Probabilities for Jumping Fault Segment Stepovers

    Microsoft Academic Search

    B. E. Shaw; J. H. Dieterich

    2006-01-01

    Seismic hazard analysis relies heavily on the segmentation of faults. The ability of ruptures to break multiple segments has a big impact on estimated hazard. Current practice for estimating multiple segment breakage relies on panels of experts voting on their opinions for each case. Here, we explore the probability of elastodynamic ruptures jumping segment stepovers in numerical simulations of segmented

  13. Current density distributions, field distributions and impedance analysis of segmented deep brain stimulation electrodes

    NASA Astrophysics Data System (ADS)

    Wei, Xuefeng F.; Grill, Warren M.

    2005-12-01

    Deep brain stimulation (DBS) electrodes are designed to stimulate specific areas of the brain. The most widely used DBS electrode has a linear array of 4 cylindrical contacts that can be selectively turned on depending on the placement of the electrode and the specific area of the brain to be stimulated. The efficacy of DBS therapy can be improved by localizing the current delivery into specific populations of neurons and by increasing the power efficiency through a suitable choice of electrode geometrical characteristics. We investigated segmented electrode designs created by sectioning each cylindrical contact into multiple rings. Prototypes of these designs, made with different materials and larger dimensions than those of clinical DBS electrodes, were evaluated in vitro and in simulation. A finite element model was developed to study the effects of varying the electrode characteristics on the current density and field distributions in an idealized electrolytic medium and in vitro experiments were conducted to measure the electrode impedance. The current density over the electrode surface increased towards the edges of the electrode, and multiple edges increased the non-uniformity of the current density profile. The edge effects were more pronounced over the end segments than over the central segments. Segmented electrodes generated larger magnitudes of the second spatial difference of the extracellular potentials, and thus required lower stimulation intensities to achieve the same level of neuronal activation as solid electrodes. For a fixed electrode conductive area, increasing the number of segments (edges) decreased the impedance compared to a single solid electrode, because the average current density over the segments increased. Edge effects played a critical role in determining the current density distributions, neuronal excitation patterns, and impedance of cylindrical electrodes, and segmented electrodes provide a means to increase the efficiency of DBS.

  14. Biomechanical comparison of mono-segment transpedicular fixation with short-segment fixation for treatment of thoracolumbar fractures: a finite element analysis.

    PubMed

    Xu, Guijun; Fu, Xin; Du, Changling; Ma, Jianxiong; Li, Zhijun; Tian, Peng; Zhang, Tao; Ma, Xinlong

    2014-10-01

    Mono-segment transpedicular fixation is a method for the treatment of certain types of thoracolumbar spinal fracture. Finite element models were constructed to evaluate the biomechanics of mono-segment transpedicular fixation of thoracolumbar fracture. Spinal motion (T10-L2) was scanned and used to establish the models. The superior half of the cortical bone of T12 was removed and the superior half of the cancellous bone of the T12 body was assigned the material properties of injured bone to mimic vertebral fracture. Transpedicular fixation of T11 and T12 was performed to produce a mono-segment fixation model; T11 and L1 were fixed to produce a short-segment fixation model. Motion differences between functional units and von Mises stress on the spine and implants were measured under axial compression, anterior bending, extensional bending, lateral bending and axial rotation. We found no significant difference between mono- and short-segment fixations in the motion of any functional unit. Stress on the T10/T11 nucleus pulposus and T10/T11 and L1/L2 annulus fibrosus increased significantly by about 75% on anterior bending, extensional bending and lateral bending. In the fracture model, stress was increased by 24% at the inferior endplate of T10 and by 43% at the superior endplate of L2. All increased stresses were reduced after fixation and lower stress was observed with mono-segment fixation. In summary, the biomechanics of mono-segment pedicle screw instrumentation was similar to that of conventional short-segment fixation. As a minimally invasive treatment, mono-segment fixation would be appropriate for the treatment of selected thoracolumbar spinal fractures. PMID:25267283

  15. An analysis of methods for the selection of atlases for use in medical image segmentation

    NASA Astrophysics Data System (ADS)

    Prescott, Jeffrey W.; Best, Thomas M.; Haq, Furqan; Jackson, Rebecca; Gurcan, Metin

    2010-03-01

    The use of atlases has been shown to be a robust method for segmentation of medical images. In this paper we explore different methods of selection of atlases for the segmentation of the quadriceps muscles in magnetic resonance (MR) images, although the results are pertinent for a wide range of applications. The experiments were performed using 103 images from the Osteoarthritis Initiative (OAI). The images were randomly split into a training set consisting of 50 images and a testing set of 53 images. Three different atlas selection methods were systematically compared. First, a set of readers was assigned the task of selecting atlases from a training population of images, which were selected to be representative subgroups of the total population. Second, the same readers were instructed to select atlases from a subset of the training data which was stratified based on population modes. Finally, every image in the training set was employed as an atlas, with no input from the readers, and the atlas which had the best initial registration, judged by an appropriate registration metric, was used in the final segmentation procedure. The segmentation results were quantified using the Zijdenbos similarity index (ZSI). The results show that over all readers the agreement of the segmentation algorithm decreased from 0.76 to 0.74 when using population modes to assist in atlas selection. The use of every image in the training set as an atlas outperformed both manual atlas selection methods, achieving a ZSI of 0.82.

  16. Sequence analysis on the information of folding initiation segments in ferredoxin-like fold proteins

    PubMed Central

    2014-01-01

    Background While some studies have shown that the 3D protein structures are more conservative than their amino acid sequences, other experimental studies have shown that even if two proteins share the same topology, they may have different folding pathways. There are many studies investigating this issue with molecular dynamics or Go-like model simulations, however, one should be able to obtain the same information by analyzing the proteins’ amino acid sequences, if the sequences contain all the information about the 3D structures. In this study, we use information about protein sequences to predict the location of their folding segments. We focus on proteins with a ferredoxin-like fold, which has a characteristic topology. Some of these proteins have different folding segments. Results Despite the simplicity of our methods, we are able to correctly determine the experimentally identified folding segments by predicting the location of the compact regions considered to play an important role in structural formation. We also apply our sequence analyses to some homologues of each protein and confirm that there are highly conserved folding segments despite the homologues’ sequence diversity. These homologues have similar folding segments even though the homology of two proteins’ sequences is not so high. Conclusion Our analyses have proven useful for investigating the common or different folding features of the proteins studied. PMID:24884463

  17. Analysis of automated highway system risks and uncertainties. Volume 5

    SciTech Connect

    Sicherman, A.

    1994-10-01

    This volume describes a risk analysis performed to help identify important Automated Highway System (AHS) deployment uncertainties and quantify their effect on costs and benefits for a range of AHS deployment scenarios. The analysis identified a suite of key factors affecting vehicle and roadway costs, capacities and market penetrations for alternative AHS deployment scenarios. A systematic protocol was utilized for obtaining expert judgments of key factor uncertainties in the form of subjective probability percentile assessments. Based on these assessments, probability distributions on vehicle and roadway costs, capacity and market penetration were developed for the different scenarios. The cost/benefit risk methodology and analysis provide insights by showing how uncertainties in key factors translate into uncertainties in summary cost/benefit indices.

  18. Synfuel program analysis. Volume I. Procedures-capabilities

    SciTech Connect

    Muddiman, J. B.; Whelan, J. W.

    1980-07-01

    This is the first of the two volumes describing the analytic procedures and resulting capabilities developed by Resource Applications (RA) for examining the economic viability, public costs, and national benefits of alternative synfuel projects and integrated programs. This volume is intended for Department of Energy (DOE) and Synthetic Fuel Corporation (SFC) program management personnel and includes a general description of the costing, venture, and portfolio models with enough detail for the reader to be able to specifiy cases and interpret outputs. It also contains an explicit description (with examples) of the types of results which can be obtained when applied to: the analysis of individual projects; the analysis of input uncertainty, i.e., risk; and the analysis of portfolios of such projects, including varying technology mixes and buildup schedules. In all cases, the objective is to obtain, on the one hand, comparative measures of private investment requirements and expected returns (under differing public policies) as they affect the private decision to proceed, and, on the other, public costs and national benefits as they affect public decisions to participate (in what form, in what areas, and to what extent).

  19. Cell lineage analysis of pattern formation in the Tubifex embryo. II. Segmentation in the ectoderm.

    PubMed

    Nakamoto, A; Arai, A; Shimizu, T

    2000-10-01

    Ectodermal segmentation in the oligochaete annelid Tubifex is a process of separation of 50-microm-wide blocks of cells from the initially continuous ectodermal germ band (GB), a cell sheet consisting of four bandlets of blast cells derived from ectoteloblasts (N, O, P and Q). In this study, using intracellular lineage tracers, we characterized the morphogenetic processes that give rise to formation of these ectodermal segments. The formation of ectodermal segments began with formation of fissures, first on the ventral side and then on the dorsal side of the GB; the unification of these fissures gave rise to separation of a 50-microm-wide block of approximately 30 cells from the ectodermal GB. A set of experiments in which individual ectoteloblasts were labeled showed that as development proceeded, an initially linear array of blast cells in each ectodermal bandlet gradually changed its shape and that its contour became indented in a lineage-specific manner. These morphogenetic changes resulted in the formation of distinct cell clumps, which were separated from the bandlet to serve as segmental elements (SEs). SEs in the N and Q lineages were each comprised of clones of two consecutive primary blast cells. In contrast, in the O and P lineages, individual blast cell clones were distributed across SE boundaries; each SE was a mixture of a part of a more anterior clone and a part of the next more posterior clone. Morphogenetic events, including segmentation, in an ectodermal bandlet proceeded normally in the absence of neighboring ectodermal bandlets. Without the underlying mesoderm, separated SEs failed to space themselves at regular intervals along the anteroposterior axis. We suggest that ectodermal segmentation in Tubifex consists of two stages, autonomous morphogenesis of each bandlet leading to generation of SEs and the ensuing mesoderm-dependent alignment of separated SEs. PMID:11128574

  20. Volume measurements of normal orbital structures by computed tomographic analysis

    SciTech Connect

    Forbes, G.; Gehring, D.G.; Gorman, C.A.; Brennan, M.D.; Jackson, I.T.

    1985-07-01

    Computed tomographic digital data and special off-line computer graphic analysis were used to measure volumes of normal orbital soft tissue, extraocular muscle, orbital fat, and total bony orbit in vivo in 29 patients (58 orbits). The upper limits of normal for adult bony orbit, soft tissue exclusive of the globe, orbital fat, and muscle are 30.1 cm/sup 3/, 20.0 cm/sup 3/, 14.4 cm/sup 3/, and 6.5 cm/sup 3/, respectively. There are small differences in men as a group compared with women but minimal difference between right and left orbits in the same person. The accuracy of the techniques was established at 7%-8% for these orbit structural volumes in physical phantoms and in simulated silicone orbit phantoms in dry skulls. Mean values and upper limits of normal for volumes were determined in adult orbital structures for future comparison with changes due to endocrine ophthalmopathy, trauma, and congenital deformity.

  1. User's operating procedures. Volume 2: Scout project financial analysis program

    NASA Technical Reports Server (NTRS)

    Harris, C. G.; Haris, D. K.

    1985-01-01

    A review is presented of the user's operating procedures for the Scout Project Automatic Data system, called SPADS. SPADS is the result of the past seven years of software development on a Prime mini-computer located at the Scout Project Office, NASA Langley Research Center, Hampton, Virginia. SPADS was developed as a single entry, multiple cross-reference data management and information retrieval system for the automation of Project office tasks, including engineering, financial, managerial, and clerical support. This volume, two (2) of three (3), provides the instructions to operate the Scout Project Financial Analysis program in data retrieval and file maintenance via the user friendly menu drivers.

  2. Immunofluorescence laser micro-dissection of specific nephron segments in the mouse kidney allows targeted downstream proteomic analysis

    PubMed Central

    Micanovic, Radmila; Khan, Shehnaz; El-Achkar, Tarek M

    2015-01-01

    Laser micro-dissection (LMD) is a very useful tool that allows the isolation of finite areas from tissue specimens for downstream analysis of RNA and protein. Although LMD has been adapted for use in kidney tissue, the use of this powerful tool has been limited by the diminished ability to identify specific tubular segments in the kidney. In this study, we describe a major improvement in the methodology to isolate specific cells in the mouse kidney using immunofluorescence LMD (IF-LMD). Using IF-LMD, we can reproducibly isolate not only glomeruli, but also S1–S2 proximal segments, S3 tubules, and thick ascending limbs. We also demonstrate the utility of a novel rapid immunofluorescence staining technique, and provide downstream applications for IF-LMD such as real-time PCR and cutting-edge proteomic studies. This technical breakthrough may become an invaluable tool for understanding cellular and molecular events in the heterogeneous kidney milieu. PMID:25677553

  3. Comparison between MDCT and Grayscale IVUS in a Quantitative Analysis of Coronary Lumen in Segments with or without Atherosclerotic Plaques

    PubMed Central

    Falcão, João L. A. A.; Falcão, Breno A. A.; Gurudevan, Swaminatha V.; Campos, Carlos M.; Silva, Expedito R.; Kalil-Filho, Roberto; Rochitte, Carlos E.; Shiozaki, Afonso A.; Coelho-Filho, Otavio R.; Lemos, Pedro A.

    2015-01-01

    Background The diagnostic accuracy of 64-slice MDCT in comparison with IVUS has been poorly described and is mainly restricted to reports analyzing segments with documented atherosclerotic plaques. Objectives We compared 64-slice multidetector computed tomography (MDCT) with gray scale intravascular ultrasound (IVUS) for the evaluation of coronary lumen dimensions in the context of a comprehensive analysis, including segments with absent or mild disease. Methods The 64-slice MDCT was performed within 72 h before the IVUS imaging, which was obtained for at least one coronary, regardless of the presence of luminal stenosis at angiography. A total of 21 patients were included, with 70 imaged vessels (total length 114.6 ± 38.3 mm per patient). A coronary plaque was diagnosed in segments with plaque burden > 40%. Results At patient, vessel, and segment levels, average lumen area, minimal lumen area, and minimal lumen diameter were highly correlated between IVUS and 64-slice MDCT (p < 0.01). However, 64-slice MDCT tended to underestimate the lumen size with a relatively wide dispersion of the differences. The comparison between 64-slice MDCT and IVUS lumen measurements was not substantially affected by the presence or absence of an underlying plaque. In addition, 64-slice MDCT showed good global accuracy for the detection of IVUS parameters associated with flow-limiting lesions. Conclusions In a comprehensive, multi-territory, and whole-artery analysis, the assessment of coronary lumen by 64-slice MDCT compared with coronary IVUS showed a good overall diagnostic ability, regardless of the presence or absence of underlying atherosclerotic plaques. PMID:25993595

  4. Motion analysis of knee joint using dynamic volume images

    NASA Astrophysics Data System (ADS)

    Haneishi, Hideaki; Kohno, Takahiro; Suzuki, Masahiko; Moriya, Hideshige; Mori, Sin-ichiro; Endo, Masahiro

    2006-03-01

    Acquisition and analysis of three-dimensional movement of knee joint is desired in orthopedic surgery. We have developed two methods to obtain dynamic volume images of knee joint. One is a 2D/3D registration method combining a bi-plane dynamic X-ray fluoroscopy and a static three-dimensional CT, the other is a method using so-called 4D-CT that uses a cone-beam and a wide 2D detector. In this paper, we present two analyses of knee joint movement obtained by these methods: (1) transition of the nearest points between femur and tibia (2) principal component analysis (PCA) of six parameters representing the three dimensional movement of knee. As a preprocessing for the analysis, at first the femur and tibia regions are extracted from volume data at each time frame and then the registration of the tibia between different frames by an affine transformation consisting of rotation and translation are performed. The same transformation is applied femur as well. Using those image data, the movement of femur relative to tibia can be analyzed. Six movement parameters of femur consisting of three translation parameters and three rotation parameters are obtained from those images. In the analysis (1), axis of each bone is first found and then the flexion angle of the knee joint is calculated. For each flexion angle, the minimum distance between femur and tibia and the location giving the minimum distance are found in both lateral condyle and medial condyle. As a result, it was observed that the movement of lateral condyle is larger than medial condyle. In the analysis (2), it was found that the movement of the knee can be represented by the first three principal components with precision of 99.58% and those three components seem to strongly relate to three major movements of femur in the knee bend known in orthopedic surgery.

  5. Segmental Analysis of Right Ventricular Longitudinal Deformation in Children before and after Percutaneous Closure of Atrial Septal Defect

    PubMed Central

    Ko, Hong Ki; Cho, Eun Kyung; Kang, So Yeon; Seo, Chang Deok; Baek, Jae Suk; Kim, Young-Hwue; Ko, Jae-Kon

    2014-01-01

    Background The aim of study is to identify the dependence of right ventricular (RV) free wall longitudinal deformation on ventricular loading through segmental approach in relatively large number of patients with atrial septal defect (ASD). Methods Patients with ASD (n = 114) and age matched healthy children (n = 60) were echocardiographically examined the day before percutaneous device closure and within 24 hours afterwards. RV free wall deformation parameters, strain (?) and strain rate (SR), were analyzed in the apical (?A, SRA) and basal (?B, SRB) segments. Measured deformation parameters were adjusted for RV size (?AL, SRAL, ?BL, SRBL) by multiplying by body surface area indexed RV longitudinal dimension. Regression analyses determined the relationships of these deformation parameters with RV loading parameters that were measured by catheterization. Results ?BL and SRBL were not different between pre-closure patients and controls (p = 0.245, p = 0.866), and were decreased post-closure (p = 0.001, p = 0.018). Post-closure ?BL was lower than in controls (p = 0.001). Pre-closure ?AL and SRAL were higher than in controls (p = 0.001, p < 0.001), but decreased after closure (all p < 0.001). The pulmonary to systemic flow ratio was related to procedural differences of ?BL (p = 0.017) and of SRBL (p = 0.019). RV end diastolic pressure was negatively related to post-closure ?BL (p = 0.020) and post-closure SRBL (p = 0.012), and the procedural SRBL difference (p = 0.027). Conclusion The longitudinal deformation of the RV basal segment is dependent and its remodeling is also dependent on volume loading in children with ASD. PMID:25580192

  6. Laser Capture Microdissection-Microarray Analysis of Focal Segmental Glomerulosclerosis Glomeruli

    Microsoft Academic Search

    Michael R. Bennett; Kimberly A. Czech; Lois J. Arend; David P. Witte; Prasad Devarajan; S. Steven Potter

    2007-01-01

    Focal segmental glomerulosclerosis (FSGS) is a major cause of end-stage renal disease. In this report we used laser capture microdissection to purify diseased glomeruli, and microarrays to provide universal gene expression profiles. The results provide a deeper understanding of the molecular mechanisms of the disease process and suggest novel therapeutic strategies. Consistent with earlier studies, molecular markers of the differentiated

  7. DRM workflow analysis for over-the-top HTTP segmented delivery

    Microsoft Academic Search

    Kevin J. Ma; Raj Nair; Radim Bartos

    2011-01-01

    Monetization of premium video content requires two key components: quality and security. In the mobile space, quality issues have been largely address in recent years through faster CPUs and segment-based HTTP adaptive bitrate delivery (e.g., Apple R ! HTTP Live Streaming, Adobe R ! HTTP

  8. SEQUENCE ANALYSIS OF THE SMALL RNA SEGMENT OF GUINEA PIG-PASSAGED PICHINDE VIRUS VARIANTS

    Microsoft Academic Search

    LIHONG ZHANG; KATHLEEN MARRIOTT; JUDITH F. ARONSON

    1999-01-01

    The established animal model for Lassa fever is based on the new world arenavirus Pichinde (PIC). Natural isolates of PIC virus are attenuated in guinea pigs, but serial guinea pig passage renders them extremely virulent in that host. We have compared the nucleotide sequences of the small RNA segments of two attenuated, low- passage variants of the PIC virus Munchique

  9. Cross-Linguistic Analysis of Prosodic Features for Sentence Segmentation James G Fung1

    E-print Network

    Shriberg, Elizabeth

    , cuendet, nikki)@eecs.berkeley.edu Abstract In this paper, we perform a cross-linguistic study of prosodic features in sentence segmentation by using two different fea- ture selection approaches: a forward search wrapper and fea- ture filtering. Experiments in Arabic, English, and Mandarin show that prosodic features

  10. CT-scan images preprocessing and segmentation to improve bioprosthesis leaflets morphological analysis

    E-print Network

    Paris-Sud XI, Université de

    CT-scan images preprocessing and segmentation to improve bioprosthesis leaflets morphological characterization of degenerated aortic bioprostheses. We believe that in the next future CT scan images with other imaging techniques, we hypothesized that the processing of multi-detector CT images would allow

  11. Intrathoracic airway trees: segmentation and airway morphology analysis from low-dose CT scans

    Microsoft Academic Search

    Juerg Tschirren; Eric A. Hoffman; Geoffrey Mclennan; Milan Sonka

    2005-01-01

    ó The segmentation of the human airway tree from volumetric computed tomography (CT) images builds an impor- tant step for many clinical applications and for physiological studies. Previously proposed algorithms suffer from one or several problems: leaking into the surrounding lung parenchyma, the need for the user to manually adjust parameters, excessive runtime. Low-dose CT scans are increasingly utilized in

  12. Genome-wide analysis of mammalian DNA segment fusion\\/fission

    Microsoft Academic Search

    Zhihua Zhang; Hong Sun; Yong Zhang; Yi Zhao; Baochen Shi; Shiwei Sun; Hongchao Lu; Dongbo Bu; Lunjiang Ling; Runsheng Chen

    2006-01-01

    As a powerful tool for gene function prediction, gene fusion has been widely studied in prokaryotes and certain groups of eukaryotes, but it has been little applied in studies of mammalian genomes. With the first fully sequenced mammalian genomes (human, mouse, rat) now available, we defined and collected a set of fusion\\/fission event-linked segments (FFLS) based on structured organized genomic

  13. A non-invasive analysis of the structure and function of human multi-segmental muscle

    Microsoft Academic Search

    Darryl John McAndrew

    2008-01-01

    The Central Nervous System (CNS) exerts extensive control over muscle activation in order to produce accurate voluntary movement, such as the complex movements of the human shoulder joint. Muscles surrounding multi-planar joints are selectively activated depending upon the movement performed, and within the radiate musculature of the shoulder, individual muscle segments exist that are capable of exhibiting specific myoelectric intensity

  14. Mathematical analysis of blood flow through an arterial segment with time?dependent stenosis

    Microsoft Academic Search

    J. C. Misra; S. D. Adhikary; G. C. Shit

    2008-01-01

    A mathematical model is developed here with an aim to study the pulsatile flow of blood through an arterial segment having a time?dependent stenosis. Blood is considered to consist of a core layer where erythrocytes are concentrated and a peripheral plasma layer that is free from erythrocytes. The plasma layer is taken to behave as a Newtonian fluid, while the

  15. Segmentation of hyper-pigmented spots in human skin using automated cluster analysis

    NASA Astrophysics Data System (ADS)

    Gossage, Kirk W.; Weissman, Jesse; Velthuizen, Robert

    2009-02-01

    The appearance and color distribution of skin are important characteristics that affect the human perception of health and vitality. Dermatologists and other skin researchers often use color and appearance to diagnose skin conditions and monitor the efficacy of procedures and treatments. Historically, most skin color and chromophore measurements have been performed using reflectance spectrometers and colorimeters. These devices acquire a single measurement over an integrated area defined by an aperture, and are therefore poorly suited to measure the color of pigmented lesions or other blemishes. Measurements of spots smaller than the aperture will be washed out with background, and spots that are larger may not be adequately sampled unless the blemish is homogenous. Recently, multispectral imaging devices have become available for skin imaging. These devices are designed to image regions of skin and provide information about the levels of endogenous chromophores present in the image field of view. This data is presented as four images at each measurement site including RGB color, melanin, collagen, and blood images. We developed a robust segmentation technique that can segment skin blemishes in these images and provide more precise values of melanin, blood, and collagen by only analyzing the segmented region of interest. Results from hundreds of skin images show this to be a robust automated segmentation technique over a range of skin tones and shades.

  16. Algorithm Evaluation by Probabilistic Fitness/Cost Analysis, and Application to Image Segmentation

    E-print Network

    Everingham, Mark

    . We believe that if segmentation algo- rithms are to be successfully applied in real vision systems of existing quantitative evaluation methods: "Analytical" methods attempt to characterize an algo- rithm of the algo- rithm, or test data. For example, one can define the time complexity of an algorithm or its

  17. Infants' Early Ability to Segment the Conversational Speech Signal Predicts Later Language Development: A Retrospective Analysis

    ERIC Educational Resources Information Center

    Newman, Rochelle; Ratner, Nan Bernstein; Jusczyk, Ann Marie; Jusczyk, Peter W.; Dow, Kathy Ayala

    2006-01-01

    Two studies examined relationships between infants' early speech processing performance and later language and cognitive outcomes. Study 1 found that performance on speech segmentation tasks before 12 months of age related to expressive vocabulary at 24 months. However, performance on other tasks was not related to 2-year vocabulary. Study 2…

  18. A Marked Point Process of Rectangles and Segments for Automatic Analysis of Digital Elevation Models

    Microsoft Academic Search

    Mathias Ortner; Xavier Descombes; Josiane Zerubia

    2008-01-01

    This work presents a framework for automatic feature extraction from images using stochastic geometry. Features in images are modeled as realizations of a spatial point process of geometrical shapes. This framework allows the incorporation of a priori knowledge on the spatial repartition of features. More specifically, we present a model based on the superposition of a process of segments and

  19. Trajectory Changes for CMS Segment A Longitudinal Analysis of Trajectory Changes in the Software Industry: The

    E-print Network

    Boyer, Edmond

    Industry: The Case of the Content Management Application Segment. Claudio Vitari1 and Aurelio Ravarini2 1 France Tel: 0033476706287; E-mail: claudio.vitari@grenoble-em.com Abstract The software industry), but the change trajectory of the industry is still not well understood. This article aims to contribute

  20. Parallel runway requirement analysis study. Volume 1: The analysis

    NASA Technical Reports Server (NTRS)

    Ebrahimi, Yaghoob S.

    1993-01-01

    The correlation of increased flight delays with the level of aviation activity is well recognized. A main contributor to these flight delays has been the capacity of airports. Though new airport and runway construction would significantly increase airport capacity, few programs of this type are currently underway, let alone planned, because of the high cost associated with such endeavors. Therefore, it is necessary to achieve the most efficient and cost effective use of existing fixed airport resources through better planning and control of traffic flows. In fact, during the past few years the FAA has initiated such an airport capacity program designed to provide additional capacity at existing airports. Some of the improvements that that program has generated thus far have been based on new Air Traffic Control procedures, terminal automation, additional Instrument Landing Systems, improved controller display aids, and improved utilization of multiple runways/Instrument Meteorological Conditions (IMC) approach procedures. A useful element to understanding potential operational capacity enhancements at high demand airports has been the development and use of an analysis tool called The PLAND_BLUNDER (PLB) Simulation Model. The objective for building this simulation was to develop a parametric model that could be used for analysis in determining the minimum safety level of parallel runway operations for various parameters representing the airplane, navigation, surveillance, and ATC system performance. This simulation is useful as: a quick and economical evaluation of existing environments that are experiencing IMC delays, an efficient way to study and validate proposed procedure modifications, an aid in evaluating requirements for new airports or new runways in old airports, a simple, parametric investigation of a wide range of issues and approaches, an ability to tradeoff air and ground technology and procedures contributions, and a way of considering probable blunder mechanisms and range of blunder scenarios. This study describes the steps of building the simulation and considers the input parameters, assumptions and limitations, and available outputs. Validation results and sensitivity analysis are addressed as well as outlining some IMC and Visual Meteorological Conditions (VMC) approaches to parallel runways. Also, present and future applicable technologies (e.g., Digital Autoland Systems, Traffic Collision and Avoidance System II, Enhanced Situational Awareness System, Global Positioning Systems for Landing, etc.) are assessed and recommendations made.

  1. Multi-resolution Shape Analysis via Non-Euclidean Wavelets: Applications to Mesh Segmentation and Surface Alignment Problems

    PubMed Central

    Kim, Won Hwa; Chung, Moo K.; Singh, Vikas

    2013-01-01

    The analysis of 3-D shape meshes is a fundamental problem in computer vision, graphics, and medical imaging. Frequently, the needs of the application require that our analysis take a multi-resolution view of the shape’s local and global topology, and that the solution is consistent across multiple scales. Unfortunately, the preferred mathematical construct which offers this behavior in classical image/signal processing, Wavelets, is no longer applicable in this general setting (data with non-uniform topology). In particular, the traditional definition does not allow writing out an expansion for graphs that do not correspond to the uniformly sampled lattice (e.g., images). In this paper, we adapt recent results in harmonic analysis, to derive Non-Euclidean Wavelets based algorithms for a range of shape analysis problems in vision and medical imaging. We show how descriptors derived from the dual domain representation offer native multi-resolution behavior for characterizing local/global topology around vertices. With only minor modifications, the framework yields a method for extracting interest/key points from shapes, a surprisingly simple algorithm for 3-D shape segmentation (competitive with state of the art), and a method for surface alignment (without landmarks). We give an extensive set of comparison results on a large shape segmentation benchmark and derive a uniqueness theorem for the surface alignment problem. PMID:24390194

  2. Oil-spill risk analysis: Cook inlet outer continental shelf lease sale 149. Volume 2: Conditional risk contour maps of seasonal conditional probabilities. Final report

    SciTech Connect

    Johnson, W.R.; Marshall, C.F.; Anderson, C.M.; Lear, E.M.

    1994-08-01

    The Federal Government has proposed to offer Outer Continental Shelf (OCS) lands in Cook Inlet for oil and gas leasing. Because oil spills may occur from activities associated with offshore oil production, the Minerals Management Service conducts a formal risk assessment. In evaluating the significance of accidental oil spills, it is important to remember that the occurrence of such spills is fundamentally probabilistic. The effects of oil spills that could occur during oil and gas production must be considered. This report summarizes results of an oil-spill risk analysis conducted for the proposed Cook Inlet OCS Lease Sale 149. The objective of this analysis was to estimate relative risks associated with oil and gas production for the proposed lease sale. To aid the analysis, conditional risk contour maps of seasonal conditional probabilities of spill contact were generated for each environmental resource or land segment in the study area. This aspect is discussed in this volume of the two volume report.

  3. Segmentation of thin section images for grain size analysis using region competition and edge-weighted region merging

    NASA Astrophysics Data System (ADS)

    Jungmann, Matthias; Pape, Hansgeorg; Wißkirchen, Peter; Clauser, Christoph; Berlage, Thomas

    2014-11-01

    Microscopic thin section images are a major source of information on physical properties, crystallization processes, and the evolution of rocks. Extracting the boundaries of grains is of special interest for estimating the volumetric structure of sandstone. To deal with large datasets and to relieve the geologist from a manual analysis of images, automated methods are needed for the segmentation task. This paper evaluates the region competition framework, which also includes region merging. The procedure minimizes an energy functional based on the Minimum Description Length (MDL) principle. To overcome some known drawbacks of current algorithms, we present an extension of MDL-based region merging by integrating edge information between adjacent regions. In addition, we introduce a modified implementation for region competition for overcoming computational complexities when dealing with multiple competing regions. Commonly used methods are based on solving differential equations for describing the movement of boundaries, whereas our approach implements a simple updating scheme. Furthermore, we propose intensity features for reducing the amount of data. They are derived by comparing theoretical values obtained from a model function describing the intensity inside uniaxial crystals with measured data. Error, standard deviation, and phase shift between the model and intensity measurements preserve sufficient information for a proper segmentation. Additionally, identified objects are classified into quartz grains, anhydrite, and reaction fringes by these features. This grouping is, in turn, used to improve the segmentation process further. We illustrate the benefits of this approach by four samples of microscopic thin sections and quantify them in a comparison of a segmentation result and a manually obtained one.

  4. Shell rendering: fast volume rendering and analysis of fuzzy surfaces

    NASA Astrophysics Data System (ADS)

    Udupa, Jayaram K.; Odhner, Dewey

    1992-05-01

    We present a new paradigm, called shell rendering, for volume visualization of surfaces. It significantly overcomes the two major impediments of current volume rendering methods -- high computational cost and storage requirements -- and makes interactive volume rendering feasible in a workstation environment via portable software. It imparts the notion of a structure -- a shell -- to what is usually treated as an amorphous semi-transparent volume and makes morphometrics of surfaces feasible in the volume rendering paradigm.

  5. Style, content and format guide for writing safety analysis documents. Volume 1, Safety analysis reports for DOE nuclear facilities

    SciTech Connect

    Not Available

    1994-06-01

    The purpose of Volume 1 of this 4-volume style guide is to furnish guidelines on writing and publishing Safety Analysis Reports (SARs) for DOE nuclear facilities at Sandia National Laboratories. The scope of Volume 1 encompasses not only the general guidelines for writing and publishing, but also the prescribed topics/appendices contents along with examples from typical SARs for DOE nuclear facilities.

  6. Computer-aided segmentation and 3D analysis of in vivo MRI examinations of the human vocal tract during phonation

    NASA Astrophysics Data System (ADS)

    Wismüller, Axel; Behrends, Johannes; Hoole, Phil; Leinsinger, Gerda L.; Meyer-Baese, Anke; Reiser, Maximilian F.

    2008-03-01

    We developed, tested, and evaluated a 3D segmentation and analysis system for in vivo MRI examinations of the human vocal tract during phonation. For this purpose, six professionally trained speakers, age 22-34y, were examined using a standardized MRI protocol (1.5 T, T1w FLASH, ST 4mm, 23 slices, acq. time 21s). The volunteers performed a prolonged (>=21s) emission of sounds of the German phonemic inventory. Simultaneous audio tape recording was obtained to control correct utterance. Scans were made in axial, coronal, and sagittal planes each. Computer-aided quantitative 3D evaluation included (i) automated registration of the phoneme-specific data acquired in different slice orientations, (ii) semi-automated segmentation of oropharyngeal structures, (iii) computation of a curvilinear vocal tract midline in 3D by nonlinear PCA, (iv) computation of cross-sectional areas of the vocal tract perpendicular to this midline. For the vowels /a/,/e/,/i/,/o/,/ø/,/u/,/y/, the extracted area functions were used to synthesize phoneme sounds based on an articulatory-acoustic model. For quantitative analysis, recorded and synthesized phonemes were compared, where area functions extracted from 2D midsagittal slices were used as a reference. All vowels could be identified correctly based on the synthesized phoneme sounds. The comparison between synthesized and recorded vowel phonemes revealed that the quality of phoneme sound synthesis was improved for phonemes /a/ and /y/, if 3D instead of 2D data were used, as measured by the average relative frequency shift between recorded and synthesized vowel formants (p<0.05, one-sided Wilcoxon rank sum test). In summary, the combination of fast MRI followed by subsequent 3D segmentation and analysis is a novel approach to examine human phonation in vivo. It unveils functional anatomical findings that may be essential for realistic modelling of the human vocal tract during speech production.

  7. 3D digital cleansing using segmentation rays

    Microsoft Academic Search

    Sarang Lakare; Ming Wan; Mie Sato; Arie E. Kaufman

    2000-01-01

    We propose a novel approach for segmentation and digital cle ans- ing of endoscopic organs. Our method can be used for a variety of segmentation needs with little or no modification. It aimsat fulfilling the dual and often conflicting requirements of a fast and accurate segmentation and also eliminates the undesirable partial volume effect which contemporary approaches cannot. For se

  8. Modeling and analysis of passive dynamic bipedal walking with segmented feet and compliant joints

    NASA Astrophysics Data System (ADS)

    Huang, Yan; Wang, Qi-Ning; Gao, Yue; Xie, Guang-Ming

    2012-10-01

    Passive dynamic walking has been developed as a possible explanation for the efficiency of the human gait. This paper presents a passive dynamic walking model with segmented feet, which makes the bipedal walking gait more close to natural human-like gait. The proposed model extends the simplest walking model with the addition of flat feet and torsional spring based compliance on ankle joints and toe joints, to achieve stable walking on a slope driven by gravity. The push-off phase includes foot rotations around the toe joint and around the toe tip, which shows a great resemblance to human normal walking. This paper investigates the effects of the segmented foot structure on bipedal walking in simulations. The model achieves satisfactory walking results on even or uneven slopes.

  9. Design and Analysis of Modules for Segmented X-Ray Optics

    NASA Technical Reports Server (NTRS)

    McClelland, Ryan S.; BIskach, Michael P.; Chan, Kai-Wing; Saha, Timo T; Zhang, William W.

    2012-01-01

    Future X-ray astronomy missions demand thin, light, and closely packed optics which lend themselves to segmentation of the annular mirrors and, in turn, a modular approach to the mirror design. The modular approach to X-ray Flight Mirror Assembly (FMA) design allows excellent scalability of the mirror technology to support a variety of mission sizes and science objectives. This paper describes FMA designs using slumped glass mirror segments for several X-ray astrophysics missions studied by NASA and explores the driving requirements and subsequent verification tests necessary to qualify a slumped glass mirror module for space-flight. A rigorous testing program is outlined allowing Technical Development Modules to reach technical readiness for mission implementation while reducing mission cost and schedule risk.

  10. Shape-Constrained Segmentation Approach for Arctic Multiyear Sea Ice Floe Analysis

    NASA Technical Reports Server (NTRS)

    Tarabalka, Yuliya; Brucker, Ludovic; Ivanoff, Alvaro; Tilton, James C.

    2013-01-01

    The melting of sea ice is correlated to increases in sea surface temperature and associated climatic changes. Therefore, it is important to investigate how rapidly sea ice floes melt. For this purpose, a new Tempo Seg method for multi temporal segmentation of multi year ice floes is proposed. The microwave radiometer is used to track the position of an ice floe. Then,a time series of MODIS images are created with the ice floe in the image center. A Tempo Seg method is performed to segment these images into two regions: Floe and Background.First, morphological feature extraction is applied. Then, the central image pixel is marked as Floe, and shape-constrained best merge region growing is performed. The resulting tworegionmap is post-filtered by applying morphological operators.We have successfully tested our method on a set of MODIS images and estimated the area of a sea ice floe as afunction of time.

  11. Three-dimensional volume analysis of vasculature in engineered tissues

    NASA Astrophysics Data System (ADS)

    YousefHussien, Mohammed; Garvin, Kelley; Dalecki, Diane; Saber, Eli; Helguera, María.

    2013-01-01

    Three-dimensional textural and volumetric image analysis holds great potential in understanding the image data produced by multi-photon microscopy. In this paper, an algorithm that quantitatively analyzes the texture and the morphology of vasculature in engineered tissues is proposed. The investigated 3D artificial tissues consist of Human Umbilical Vein Endothelial Cells (HUVEC) embedded in collagen exposed to two regimes of ultrasound standing wave fields under different pressure conditions. Textural features were evaluated using the normalized Gray-Scale Cooccurrence Matrix (GLCM) combined with Gray-Level Run Length Matrix (GLRLM) analysis. To minimize error resulting from any possible volume rotation and to provide a comprehensive textural analysis, an averaged version of nine GLCM and GLRLM orientations is used. To evaluate volumetric features, an automatic threshold using the gray level mean value is utilized. Results show that our analysis is able to differentiate among the exposed samples, due to morphological changes induced by the standing wave fields. Furthermore, we demonstrate that providing more textural parameters than what is currently being reported in the literature, enhances the quantitative understanding of the heterogeneity of artificial tissues.

  12. An EM Approach to MAP Solution of Segmenting Tissue Mixtures: A Numerical Analysis

    Microsoft Academic Search

    Zhengrong Liang; Su Wang

    2009-01-01

    This work presents an iterative expectation-maximization (EM) approach to the maximum a posteriori (MAP) solution of segmenting tissue mixtures inside each image voxel. Each tissue type is assumed to follow a normal distribution across the field-of-view (FOV). Furthermore, all tissue types are assumed to be independent from each other. Under these assumptions, the summation of all tissue mixtures inside each

  13. Analysis of ground segment broadcast architectures for the Wideband Gapfiller Satellite (WGS)

    Microsoft Academic Search

    R. A. Williams; H. I. Paul

    2002-01-01

    The purpose of this paper is to summarize the findings of an assessment tasked by the joint staff regarding the broadcast ground segment architecture for the Wideband Gapfiller Satellite (WGS). WGS has the capability to permit Global Broadcast Service (GBS) injection at either Ka-band (30 GHz) or X-band (8-GHz), and be cross-banded and received by current GBS receive-only suites at

  14. Algorithms And System For Segmentation And Structure Analysis In Soccer Video

    Microsoft Academic Search

    Peng Xu; Lexing Xie; Shih-fu Chang; Ajay Divakaran; Anthony Vetro; Huifang Sun

    2001-01-01

    In this paper, we present a novel system and effective algorithms for soccer video segmentation. The output, about whether the ball is in play, reveals high-level structure of the content. The first step is to classify each sample frame into 3 kinds of view using a unique domain-specific feature, grass-area-ratio. Here the grass value and classification rules are learned and

  15. A novel approach to non-segmented flow analysis. Part 2. A prototype high-performance analyser

    PubMed Central

    Malcolme-Lawes, D. J.; Pasquini, C.

    1988-01-01

    A high-performance continuous flow analyser is described, based on gas pressure driven carrier and reagents controlled by computer switched solenoid valves. The principal characteristics of the analyser are discussed and examples of its performance are provided in the form of results obtained using a standard procedure for the determination of Cr(VI). The system was also tested in use with real samples using an ammonium ion analysis on potable and effluent water samples, and the results compared with those obtained using a segmented continuous flow method operated at the Laboratory of the Government Chemist. PMID:18925185

  16. Knowledge-based method for segmentation and analysis of lung boundaries in chest X-ray images.

    PubMed

    Brown, M S; Wilson, L S; Doust, B D; Gill, R W; Sun, C

    1998-01-01

    We present a knowledge-based approach to segmentation and analysis of the lung boundaries in chest X-rays. Image edges are matched to an anatomical model of the lung boundary using parametric features. A modular system architecture was developed which incorporates the model, image processing routines, an inference engine and a blackboard. Edges associated with the lung boundary are automatically identified and abnormal features are reported. In preliminary testing on 14 images for a set of 18 detectable abnormalities, the system showed a sensitivity of 88% and a specificity of 95% when compared with assessment by an experienced radiologist. PMID:10098894

  17. Quantitative morphological analysis of curvilinear network for microscopic image based on individual fibre segmentation (IFS).

    PubMed

    Qiu, J; Li, F-F

    2014-12-01

    Microscopic images of curvilinear fibre network structure like cytoskeleton are traditionally analysed by qualitative observation, which can hardly provide quantitative information of their morphological properties. However, such information is crucially contributive to the understanding of important biological events, even helps to learn about the inner relations hard to perceive. Individual fibre segmentation-based curvilinear structure detector proposed in this study can identify each individual fibre in the network, as well as connections between different fibres. Quantitative information of each individual fibre, including length, orientation and position, can be extracted; so are the connecting modes in the fibre network, such as bifurcation, intersection and overlap. Distribution of fibres with different morphological properties is also presented. No manual intervening or subjective judging is required in the analysing process. Both synthesized and experimental microscopic images have verified that the detector is capable to segment curvilinear network at the subcellular level with strong noise immunity. The proposed detector is finally applied to the morphological study on cytoskeleton. It is believed that the individual fibre segmentation-based curvilinear structure detector can greatly enhance our understanding of those biological images generated from tons of biological experiments. PMID:25243901

  18. Challenges in the segmentation and analysis of X-ray Micro-CT image data

    NASA Astrophysics Data System (ADS)

    Larsen, J. D.; Schaap, M. G.; Tuller, M.; Kulkarni, R.; Guber, A.

    2014-12-01

    Pore scale modeling of fluid flow is becoming increasing popular among scientific disciplines. With increased computational power, and technological advancements it is now possible to create realistic models of fluid flow through highly complex porous media by using a number of fluid dynamic techniques. One such technique that has gained popularity is lattice Boltzmann for its relative ease of programming and ability to capture and represent complex geometries with simple boundary conditions. In this study lattice Boltzmann fluid models are used on macro-porous silt loam soil imagery that was obtained using an industrial CT scanner. The soil imagery was segmented with six separate automated segmentation standards to reduce operator bias and provide distinction between phases. The permeability of the reconstructed samples was calculated, with Darcy's Law, from lattice Boltzmann simulations of fluid flow in the samples. We attempt to validate simulated permeability from differing segmentation algorithms to experimental findings. Limitations arise with X-ray micro-CT image data. Polychromatic X-ray CT has the potential to produce low image contrast and image artifacts. In this case, we find that the data is unsegmentable and unable to be modeled in a realistic and unbiased fashion.

  19. NOTE: Reducing the number of segments in unidirectional MLC segmentations

    NASA Astrophysics Data System (ADS)

    Mellado, X.; Cruz, S.; Artacho, J. M.; Canellas, M.

    2010-02-01

    In intensity-modulated radiation therapy (IMRT), fluence matrices obtained from a treatment planning system are usually delivered by a linear accelerator equipped with a multileaf collimator (MLC). A segmentation method is needed for decomposing these fluence matrices into segments suitable for the MLC, and the number of segments used is an important factor for treatment time. In this work, an algorithm for reduction of the number of segments (NS) is presented for unidirectional segmentations, where there is no backtracking of the MLC leaves. It uses a geometrical representation of the segmentation output for searching the key values in a fluence matrix that complicate its decomposition. The NS reduction is achieved by performing minor modifications in these values, under the conditions of avoiding substantial modifications of the dose-volume histogram, and does not increase in average the total number of monitor units delivered. The proposed method was tested using two clinical cases planned with the PCRT 3D® treatment planning system.

  20. Efficacy of bronchoscopic lung volume reduction: a meta-analysis

    PubMed Central

    Iftikhar, Imran H; McGuire, Franklin R; Musani, Ali I

    2014-01-01

    Background Over the last several years, the morbidity, mortality, and high costs associated with lung volume reduction (LVR) surgery has fuelled the development of different methods for bronchoscopic LVR (BLVR) in patients with emphysema. In this meta-analysis, we sought to study and compare the efficacy of most of these methods. Methods Eligible studies were retrieved from PubMed and Embase for the following BLVR methods: one-way valves, sealants (BioLVR), LVR coils, airway bypass stents, and bronchial thermal vapor ablation. Primary study outcomes included the mean change post-intervention in the lung function tests, the 6-minute walk distance, and the St George’s Respiratory Questionnaire. Secondary outcomes included treatment-related complications. Results Except for the airway bypass stents, all other methods of BLVR showed efficacy in primary outcomes. However, in comparison, the BioLVR method showed the most significant findings and was the least associated with major treatment-related complications. For the BioLVR method, the mean change in forced expiratory volume (in first second) was 0.18 L (95% confidence interval [CI]: 0.09 to 0.26; P<0.001); in 6-minute walk distance was 23.98 m (95% CI: 12.08 to 35.88; P<0.01); and in St George’s Respiratory Questionnaire was -8.88 points (95% CI: ?12.12 to ?5.64; P<0.001). Conclusion The preliminary findings of our meta-analysis signify the importance of most methods of BLVR. The magnitude of the effect on selected primary outcomes shows noninfe-riority, if not equivalence, when compared to what is known for surgical LVR. PMID:24868153

  1. Segmental neurofibromatosis

    PubMed Central

    Galhotra, Virat; Sheikh, Soheyl; Jindal, Sanjeev; Singla, Anshu

    2014-01-01

    Segmental neurofibromatosis is a rare disorder, characterized by neurofibromas or caf?-au-lait macules limited to one region of the body. Its occurrence on the face is extremely rare and only few cases of segmental neurofibromatosis over the face have been described so far. We present a case of segmental neurofibromatosis involving the buccal mucosa, tongue, cheek, ear, and neck on the right side of the face. PMID:25565748

  2. Doppler segmentation

    E-print Network

    Yeh, Chih-Ping

    1983-01-01

    DOPPLER SEGMENTATION A Thesis by CHIH-PING YEH Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May 1983 Major Subject: Electrical Engineering DOPPLER... SEGMENTATION A Thesis by CHIH-PING YEH Approved as to style and content by Norman . Griswo d Chairman of Commi tee) omas R. Fischer (Member) Char s A. smut (Member) M. B. Jones, Jr. (Head of Department) May 1983 ABSTRACT Doppler Segmentation...

  3. Automatic segmentation and identification of solitary pulmonary nodules on follow-up CT scans based on local intensity structure analysis and non-rigid image registration

    NASA Astrophysics Data System (ADS)

    Chen, Bin; Naito, Hideto; Nakamura, Yoshihiko; Kitasaka, Takayuki; Rueckert, Daniel; Honma, Hirotoshi; Takabatake, Hirotsugu; Mori, Masaki; Natori, Hiroshi; Mori, Kensaku

    2011-03-01

    This paper presents a novel method that can automatically segment solitary pulmonary nodule (SPN) and match such segmented SPNs on follow-up thoracic CT scans. Due to the clinical importance, a physician needs to find SPNs on chest CT and observe its progress over time in order to diagnose whether it is benign or malignant, or to observe the effect of chemotherapy for malignant ones using follow-up data. However, the enormous amount of CT images makes large burden tasks to a physician. In order to lighten this burden, we developed a method for automatic segmentation and assisting observation of SPNs in follow-up CT scans. The SPNs on input 3D thoracic CT scan are segmented based on local intensity structure analysis and the information of pulmonary blood vessels. To compensate lung deformation, we co-register follow-up CT scans based on an affine and a non-rigid registration. Finally, the matches of detected nodules are found from registered CT scans based on a similarity measurement calculation. We applied these methods to three patients including 14 thoracic CT scans. Our segmentation method detected 96.7% of SPNs from the whole images, and the nodule matching method found 83.3% correspondences from segmented SPNs. The results also show our matching method is robust to the growth of SPN, including integration/separation and appearance/disappearance. These confirmed our method is feasible for segmenting and identifying SPNs on follow-up CT scans.

  4. Scott Soames. Philosophical Analysis in the Twentieth Century. Volume 1: The Dawn of Analysis. Volume 2: The Age of Meaning. Princeton: Princeton University Press, 2003.

    E-print Network

    Pincock, Chris

    1 Scott Soames. Philosophical Analysis in the Twentieth Century. Volume 1: The Dawn of Analysis's conception of analysis in part two, and logical positivism in part three. It is noteworthy that Soames takes in the coffin of ordinary language philosophy. In part five, Soames returns to Quine, this time discussing

  5. Texture-based segmentation and analysis of emphysema depicted on CT images

    NASA Astrophysics Data System (ADS)

    Tan, Jun; Zheng, Bin; Wang, Xingwei; Lederman, Dror; Pu, Jiantao; Sciurba, Frank C.; Gur, David; Leader, J. Ken

    2011-03-01

    In this study we present a texture-based method of emphysema segmentation depicted on CT examination consisting of two steps. Step 1, a fractal dimension based texture feature extraction is used to initially detect base regions of emphysema. A threshold is applied to the texture result image to obtain initial base regions. Step 2, the base regions are evaluated pixel-by-pixel using a method that considers the variance change incurred by adding a pixel to the base in an effort to refine the boundary of the base regions. Visual inspection revealed a reasonable segmentation of the emphysema regions. There was a strong correlation between lung function (FEV1%, FEV1/FVC, and DLCO%) and fraction of emphysema computed using the texture based method, which were -0.433, -.629, and -0.527, respectively. The texture-based method produced more homogeneous emphysematous regions compared to simple thresholding, especially for large bulla, which can appear as speckled regions in the threshold approach. In the texture-based method, single isolated pixels may be considered as emphysema only if neighboring pixels meet certain criteria, which support the idea that single isolated pixels may not be sufficient evidence that emphysema is present. One of the strength of our complex texture-based approach to emphysema segmentation is that it goes beyond existing approaches that typically extract a single or groups texture features and individually analyze the features. We focus on first identifying potential regions of emphysema and then refining the boundary of the detected regions based on texture patterns.

  6. SignatureSpace: A Multidimensional, Exploratory Approach for the Analysis of Volume Data

    Microsoft Academic Search

    Kith Pradhan; Dirk Bartz; Klaus Mueller

    2005-01-01

    ABSTRACT The analysis of volumetric data is a crucial part in the visualization pipeline, since it determines the features in a volume dataset and henceforth, also its rendering parameters. Unfortunately, volume analysis can also be a very tedious and difcult challenge. To cope with this challenge, this paper describes a novel infor- mation visualization driven, explorative approach that allows users

  7. Phylogenetic analysis, genomic diversity and classification of M class gene segments of turkey reoviruses.

    PubMed

    Mor, Sunil K; Marthaler, Douglas; Verma, Harsha; Sharafeldin, Tamer A; Jindal, Naresh; Porter, Robert E; Goyal, Sagar M

    2015-03-23

    From 2011 to 2014, 13 turkey arthritis reoviruses (TARVs) were isolated from cases of swollen hock joints in 2-18-week-old turkeys. In addition, two isolates from similar cases of turkey arthritis were received from another laboratory. Eight turkey enteric reoviruses (TERVs) isolated from fecal samples of turkeys were also used for comparison. The aims of this study were to characterize turkey reovirus (TRV) based on complete M class genome segments and to determine genetic diversity within TARVs in comparison to TERVs and chicken reoviruses (CRVs). Nucleotide (nt) cut off values of 84%, 83% and 85% for the M1, M2 and M3 gene segments were proposed and used for genotype classification, generating 5, 7, and 3 genotypes, respectively. Using these nt cut off values, we propose M class genotype constellations (GCs) for avian reoviruses. Of the seven GCs, GC1 and GC3 were shared between the TARVs and TERVs, indicating possible reassortment between turkey and chicken reoviruses. The TARVs and TERVs were divided into three GCs, and GC2 was unique to TARVs and TERVs. The proposed new GC approach should be useful in identifying reassortant viruses, which may ultimately be used in the design of a universal vaccine against both chicken and turkey reoviruses. PMID:25655814

  8. Urinary bladder segmentation in CT urography (CTU) using CLASS

    PubMed Central

    Hadjiiski, Lubomir; Chan, Heang-Ping; Cohan, Richard H.; Caoili, Elaine M.; Law, Yuen; Cha, Kenny; Zhou, Chuan; Wei, Jun

    2013-01-01

    Purpose: The authors are developing a computerized system for bladder segmentation on CTU, as a critical component for computer aided diagnosis of bladder cancer. Methods: A challenge for bladder segmentation is the presence of regions without contrast (NC) and filled with intravenous contrast (C). The authors have designed a Conjoint Level set Analysis and Segmentation System (CLASS) specifically for this application. CLASS performs a series of image processing tasks: preprocessing, initial segmentation, 3D and 2D level set segmentation, and postprocessing, designed according to the characteristics of the bladder in CTU. The NC and the C regions of the bladder were segmented separately in CLASS. The final contour is obtained in the postprocessing stage by the union of the NC and C contours. With Institutional Review Board (IRB) approval, the authors retrospectively collected 81 CTU scans, in which 40 bladders contained lesions, 26 contained diffuse wall thickening, and 15 were considered to be normal. The bladders were segmented by CLASS and the performance was assessed by rating the quality of the contours on a 10-point scale (1 = “very poor,” 5 = “fair,” 10 = “perfect”). For 30 bladders, 3D hand-segmented contours were obtained and the segmentation accuracy of CLASS was evaluated and compared to that of a single level set method in terms of the average minimum distance, average volume intersection ratio, average volume error and Jaccard index. Results: Of the 81 bladders, the average quality rating for CLASS was 6.5 ± 1.3. Thirty nine bladders were given quality ratings of 7 or above. Only five bladders had ratings under 5. The average minimum distance, average volume intersection ratio, average volume error, and average Jaccard index for CLASS were 3.5 ± 1.3 mm, (79.0 ± 8.2)%, (16.1 ± 16.3)%, and (75.7 ± 8.4)%, respectively, and for the single level set method were 5.2 ± 2.6 mm, (78.8 ± 16.3)%, (8.3 ± 33.1)%, (71.0 ± 15.4)%, respectively. Conclusions: The results demonstrate the potential of CLASS for segmentation of the bladder. PMID:24320439

  9. Analysis of iris structure and iridocorneal angle parameters with anterior segment optical coherence tomography in Fuchs' uveitis syndrome.

    PubMed

    Basarir, Berna; Altan, Cigdem; Pinarci, Eylem Yaman; Celik, Ugur; Satana, Banu; Demirok, Ahmet

    2013-06-01

    To evaluate the differences in the biometric parameters of iridocorneal angle and iris structure measured by anterior segment optical coherence tomography (AS-OCT) in Fuchs' uveitis syndrome (FUS). Seventy-six eyes of 38 consecutive patients with the diagnosis of unilateral FUS were recruited into this prospective, cross-sectional and comparative study. After a complete ocular examination, anterior segment biometric parameters were measured by Visante(®) AS-OCT. All parameters were compared between the two eyes of each patient statistically. The mean age of the 38 subjects was 32.5 ± 7.5 years (18 female and 20 male). The mean visual acuity was lower in eyes with FUS (0.55 ± 0.31) than in healthy eyes (0.93 ± 0.17). The central corneal thickness did not differ significantly between eyes. All iridocorneal angle parameters (angle-opening distance 500 and 750, scleral spur angle, trabecular-iris space (TISA) 500 and 750) except TISA 500 in temporal quadrant were significantly larger in eyes with FUS than in healthy eyes. Anterior chamber depth was deeper in the eyes with FUS than in the unaffected eyes. With regard to iris measurements, iris thickness in the thickest part, iris bowing and iris shape were all statistically different between the affected eye and the healthy eye in individual patients with FUS. However, no statistically significant differences were evident in iris thickness 500 ?m, thickness in the middle and iris length. There were significant difference in iris shape between the two eyes of patients with glaucoma. AS-OCT as an imaging method provides us with many informative resultsin the analysis of anterior segment parameters in FUS. PMID:23277205

  10. Genetic variation in Tula hantaviruses: sequence analysis of the S and M segments of strains from Central Europe.

    PubMed

    Plyusnin, A; Cheng, Y; Vapalahti, O; Pejcoch, M; Unar, J; Jelinkova, Z; Lehväslaiho, H; Lundkvist, A; Vaheri, A

    1995-12-01

    Hantavirus carried by the European common vole Microtus arvalis from Moravia (Czech Republic) was analyzed by RT-PCR-sequencing and by reactivity with a panel of monoclonal antibodies (MAbs). Sequencing of the full-length S segment and the proximal part of the M segment showed that the virus belonged to genotype Tula (TUL) we discovered earlier in Microtus arvalis from Central Russia. This finding supported the concept of host dependence of hantaviruses. Phylogenetic analyses suggested a similar evolutionary history for S and M genes of TUL strains; thus far there is no evidence for reassortment in TUL. Geographic clustering of TUL genetic variants was observed and different levels of the genetic variability were revealed resembling those estimated for another hantavirus, Puumala (PUU). Comparison of the deduced N protein sequence from Russia and from Moravia showed that genetic drift in TUL occurred not only by accumulation of point mutations but also by the deletion of a nucleotide triplet. It encoded Ser252 which was located within a highly variable hydrophilic part of the N protein carrying B-cell epitopes and presumably forming a loop. Analysis of naturally expressed TUL N-antigen derived from lung tissue of infected voles with MAbs indicated antigenic heterogeneity among TUL strains. PMID:8837887

  11. Fractal analysis of laplacian pyramidal filters applied to segmentation of soil images.

    PubMed

    de Castro, J; Ballesteros, F; Méndez, A; Tarquis, A M

    2014-01-01

    The laplacian pyramid is a well-known technique for image processing in which local operators of many scales, but identical shape, serve as the basis functions. The required properties to the pyramidal filter produce a family of filters, which is unipara metrical in the case of the classical problem, when the length of the filter is 5. We pay attention to gaussian and fractal behaviour of these basis functions (or filters), and we determine the gaussian and fractal ranges in the case of single parameter a. These fractal filters loose less energy in every step of the laplacian pyramid, and we apply this property to get threshold values for segmenting soil images, and then evaluate their porosity. Also, we evaluate our results by comparing them with the Otsu algorithm threshold values, and conclude that our algorithm produce reliable test results. PMID:25114957

  12. Fractal Analysis of Laplacian Pyramidal Filters Applied to Segmentation of Soil Images

    PubMed Central

    de Castro, J.; Méndez, A.; Tarquis, A. M.

    2014-01-01

    The laplacian pyramid is a well-known technique for image processing in which local operators of many scales, but identical shape, serve as the basis functions. The required properties to the pyramidal filter produce a family of filters, which is unipara metrical in the case of the classical problem, when the length of the filter is 5. We pay attention to gaussian and fractal behaviour of these basis functions (or filters), and we determine the gaussian and fractal ranges in the case of single parameter a. These fractal filters loose less energy in every step of the laplacian pyramid, and we apply this property to get threshold values for segmenting soil images, and then evaluate their porosity. Also, we evaluate our results by comparing them with the Otsu algorithm threshold values, and conclude that our algorithm produce reliable test results. PMID:25114957

  13. Sequence analysis of the medium (M) segment of Cache Valley virus, with comparison to other Bunyaviridae.

    PubMed

    Brockus, C L; Grimstad, P R

    1999-01-01

    The complete sequence of the medium (M) segment of Cache Valley virus (CVV), a human neuropathogen, has been determined using a series of overlapping cDNA clones. The viral complementary-sense RNA is comprised of 4463 nucleotides which encodes a polyprotein precursor of 1435 amino acids, starting at AUG at bases 49-51 to a UGA stop codon at bases 4351-4353. This polyprotein-encoding sequence is arranged as G2-NSm-G1. The base composition of the segment is 34.9% A, 17.0% C, 19.4% G and 28.7% U. Comparison of the nucleotide sequence to the prototype Bunyamwera virus sequence shows an identity of 63%, indicating several differences exist within the individual coding regions, most notably within the NSm and G1 coding regions. Based on two presumed cleavage points within the precursor, the G2 glycoprotein, encoded from nt 94-951, is 286 amino acids long, and has two sites of potential glycosylation. NSm, encoded from nt 952-1476, is 175 amino acids, while the largest glycoprotein, G1, encoded from nt 1477-4350, consists of 958 amino acids, and has five potential glycosylation sites, two of which appear to be unique to CVV. The subsequent study of these glycosylation sites and potential differences between the sequence of this prototype CVV strain and other geographic isolates may suggest the means for improving detection of human infections as well as mapping differences in neurovirulence, neuroinvasiveness and other aspects of pathogenicity. PMID:10499453

  14. Quantitative Analysis of Segmented Fluorescein Angiography Images for the Follow-up of Choroidal Neovascular Membrane

    PubMed Central

    Ghosh, Sambuddha; Haldar, Pampa; Ravindran, Prashanth; Chatterjee, Jyotirmoy; Paranjape, Sandeep V.; Bhaduri, Gautam

    2015-01-01

    Purpose: The aim of this study was to evaluate choroidal neovascular (CNV) lesions with fluorescein angiography (FA) and to identify quantitative parameters and correlate these parameters to treatment outcomes. Subjects and Methods: This institution based cross-sectional study evaluated 30 eyes with active sub-foveal predominantly classic CNV treated with bevacizumab. Pre- and post-injection segmented FA images were analyzed. Lesion area and CNV lesion were manually delineated. Outcome measure was the change 1-month after each injection in different intensity values (0–255 divided in eight regions A [lowest intensity] to H [highest intensity] on a linear scale) in lesion area, perimeter, greatest linear dimension (GLD), area, visual acuity (VA) and central macular thickness (CMT). Results: At month 3, statistically significant changes from baseline occurred in VA, CMT, lesion area, GLD and perimeter (P < 0.05 all comparisons). Change in CMT from baseline to 3 months postinjection was correlated with change in VA (P = 0.009, r = 0.469) and intensity regions B (P = 0.001, r = ?0.565), D (P = 0.001, r = 0.560), E (P = 0.035, r = 0.386). At month 3, change in intensity values 0–63 (A + B) was negatively correlated with CMT (P = 0.001, r = ?0.575) and lesion area (P = 0.019, r = ?0.427); change in intensity values 64–223 (C-G) was positively correlated with CMT (P = 0.000, r = 0.636) and lesion area (P = 0.002, r = 0.551). Conclusions: Decrease in area, GLD, perimeter and area with intensity ? 64 on segmented FA were associated with a favorable outcome of treatment. These parameters may be useful adjuncts to existing evaluation techniques during follow-up of CNV. PMID:25949076

  15. A link-segment model of upright human posture for analysis of head-trunk coordination

    NASA Technical Reports Server (NTRS)

    Nicholas, S. C.; Doxey-Gasway, D. D.; Paloski, W. H.

    1998-01-01

    Sensory-motor control of upright human posture may be organized in a top-down fashion such that certain head-trunk coordination strategies are employed to optimize visual and/or vestibular sensory inputs. Previous quantitative models of the biomechanics of human posture control have examined the simple case of ankle sway strategy, in which an inverted pendulum model is used, and the somewhat more complicated case of hip sway strategy, in which multisegment, articulated models are used. While these models can be used to quantify the gross dynamics of posture control, they are not sufficiently detailed to analyze head-trunk coordination strategies that may be crucial to understanding its underlying mechanisms. In this paper, we present a biomechanical model of upright human posture that extends an existing four mass, sagittal plane, link-segment model to a five mass model including an independent head link. The new model was developed to analyze segmental body movements during dynamic posturography experiments in order to study head-trunk coordination strategies and their influence on sensory inputs to balance control. It was designed specifically to analyze data collected on the EquiTest (NeuroCom International, Clackamas, OR) computerized dynamic posturography system, where the task of maintaining postural equilibrium may be challenged under conditions in which the visual surround, support surface, or both are in motion. The performance of the model was tested by comparing its estimated ground reaction forces to those measured directly by support surface force transducers. We conclude that this model will be a valuable analytical tool in the search for mechanisms of balance control.

  16. volumes

    Microsoft Academic Search

    B. S. von Ungern-Sternberg; A. Regli; M. C. Schneider; F. Kunz; A. Reber

    Methods. We prospectively studied 161 patients having either breast surgery (Group A, n=80) or lower abdominal laparotomy (Group B, n=81). Premedication and general anaesthesia were standardized. Spirometry was measured with the patient supine, in a 30? head-up position. We measured vital capacity (VC), forced vital capacity, peak expiratory flow and forced expiratory volume in 1 s at preoperative assessment (baseline),

  17. Analysis of flexible aircraft longitudinal dynamics and handling qualities. Volume 1: Analysis methods

    NASA Technical Reports Server (NTRS)

    Waszak, M. R.; Schmidt, D. S.

    1985-01-01

    As aircraft become larger and lighter due to design requirements for increased payload and improved fuel efficiency, they will also become more flexible. For highly flexible vehicles, the handling qualities may not be accurately predicted by conventional methods. This study applies two analysis methods to a family of flexible aircraft in order to investigate how and when structural (especially dynamic aeroelastic) effects affect the dynamic characteristics of aircraft. The first type of analysis is an open loop model analysis technique. This method considers the effects of modal residue magnitudes on determining vehicle handling qualities. The second method is a pilot in the loop analysis procedure that considers several closed loop system characteristics. Volume 1 consists of the development and application of the two analysis methods described above.

  18. A registration-based segmentation method with application to adiposity analysis of mice microCT images

    NASA Astrophysics Data System (ADS)

    Bai, Bing; Joshi, Anand; Brandhorst, Sebastian; Longo, Valter D.; Conti, Peter S.; Leahy, Richard M.

    2014-04-01

    Obesity is a global health problem, particularly in the U.S. where one third of adults are obese. A reliable and accurate method of quantifying obesity is necessary. Visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) are two measures of obesity that reflect different associated health risks, but accurate measurements in humans or rodent models are difficult. In this paper we present an automatic, registration-based segmentation method for mouse adiposity studies using microCT images. We co-register the subject CT image and a mouse CT atlas. Our method is based on surface matching of the microCT image and an atlas. Surface-based elastic volume warping is used to match the internal anatomy. We acquired a whole body scan of a C57BL6/J mouse injected with contrast agent using microCT and created a whole body mouse atlas by manually delineate the boundaries of the mouse and major organs. For method verification we scanned a C57BL6/J mouse from the base of the skull to the distal tibia. We registered the obtained mouse CT image to our atlas. Preliminary results show that we can warp the atlas image to match the posture and shape of the subject CT image, which has significant differences from the atlas. We plan to use this software tool in longitudinal obesity studies using mouse models.

  19. Breast segmentation in infrared images

    Microsoft Academic Search

    Seckin Ozsarac; Gozde Bozdagi Akar

    2012-01-01

    Breast cancer detection with infrared imaging is a technique that is hazardous radiation free, increases the early detection chance and has a high detection probability. Asymmetry analysis is used for the diagnosis and the analysis is done using the breast segments obtained from the infrared image. In this work, a breast segmentation system based on parabolic Hough transform is presented.

  20. Data for the screening assessment: Volume 2, Appendix A, diskette 4 of 6. Columbia River comprehensive impact assessment: groundwater raw data for segments 20 and 21

    SciTech Connect

    Miley, T.B.; O`Neil, T.K.; Gilbert, R.O.; Klevgard, L.A.; Walters, T.B.

    1997-04-01

    This report is from Appendix A - diskette 4 of 6 titled Groundwater Raw Data for Segments 20, 21; data for the Screening Assessment Columbia River Comprehensive Impact Assessment. The File Name: gwseg**.csv

  1. Data for the screening assessment: Volume 2, Appendix A, diskette 2 of 6. Columbia River comprehensive impact assessment: groundwater raw data for segments 6--9

    SciTech Connect

    Miley, T.B.; O`Neil, T.K; Gilbert, R.O.; Klevgard, L.A.; Walters, T.B.

    1997-04-01

    This report is from Appendix A - diskette 2 of 6 titled Groundwater Raw Data for Segments 6-9; Data for the Screening Assessment Columbia River Comprehensive Impact Assessment. The File Name:gwseg**.csv.

  2. Data for the screening assessment: Volume 2, Appendix A, diskette 1 of 6. Columbia River comprehensive impact assessment: groundwater raw data for segments 1--5

    SciTech Connect

    Miley, T.B.; O`Neil, T.K.; Gilbert, R.O.; Klevgard, L.A.; Walters, T.B.

    1997-04-01

    This report is from Appendix A - diskette 1 of 6 titled Groundwater Raw Data for Segments 1-5; Data for the Screening Assessment Columbia River Comprehensive Impact Assessment. The File Name: gwseg**.csv

  3. ATHOS: a computer program for thermal-hydraulic analysis of steam generators. Volume 2. Programmer's manual

    SciTech Connect

    Singhal, A.K.; Keeton, L.W.; Przekwas, A.J.; Weems, J.S.

    1982-10-01

    ATHOS (Analysis of the Thermal Hydraulics of Steam Generators) is a computer code developed by CHAM of North America Incorporated, under the contract RP 1066-1 from the Electric Power Research Institute, Palo Alto, California. ATHOS supercedes the earlier code URSULA2. ATHOS is designed for three-dimensional, steady-state and transient analyses of PWR steam generators. The current version of the code has been checked out for: three different configurations of the recirculating-type U-tube steam generators; the homogeneous and algebraic-slip flow models; and full and part load operating conditions. The description of ATHOS is divided into the following four volumes: Volume 1, Mathematical and Physical Models and Methods of Solution; Volume 2, Programmer's Manual; Volume 3, User's Manual; and Volume 4, Applications. The code's possible uses, capabilities and limitations are described in Volume 1 as well as in Volume 3.

  4. Cargo Logistics Airlift Systems Study (CLASS). Volume 1: Analysis of current air cargo system

    NASA Technical Reports Server (NTRS)

    Burby, R. J.; Kuhlman, W. H.

    1978-01-01

    The material presented in this volume is classified into the following sections; (1) analysis of current routes; (2) air eligibility criteria; (3) current direct support infrastructure; (4) comparative mode analysis; (5) political and economic factors; and (6) future potential market areas. An effort was made to keep the observations and findings relating to the current systems as objective as possible in order not to bias the analysis of future air cargo operations reported in Volume 3 of the CLASS final report.

  5. Navier-Stokes analysis of two- and three-dimensional flow field in solid rocket motors with segment joints

    NASA Technical Reports Server (NTRS)

    Sabnis, J. S.; Gibeling, H. J.; Mcdonald, H.

    1987-01-01

    A multidimensional implicit Navier-Stokes analysis which uses numerical solution of ensemble-averaged Navier-Stokes equations in a nonorthogonal bodyfitted cylindrical-polar coordinate system has been applied to simulation of the internal flow field in solid-propellant rocket motor chambers with segment joints. The calculation procedure incorporates a two-equation (k-epsilon) turbulence model and utilizes a consistently split, linearized block-implicit algorithm for numerical solution of the governing equations. Computations performed to simulate the axisymmetric flow field in the vicinity of the aft field joint in the Space Shuttle SRB using 14,725 grid points show the presence of a region of reversed axial flow near the downstream edge of the slot. Calculations were also performed for two cases involving asymmetric three-dimensional flow in the vicinity of the aft field joint in the SRB using 721,525 grid points to estimate circumferential velocities and pressure gradients at the joint.

  6. Navier-Stokes analysis of two- and three-dimensional flow field in solid rocket motors with segment joints

    NASA Astrophysics Data System (ADS)

    Sabnis, J. S.; Gibeling, H. J.; McDonald, H.

    1987-06-01

    A multidimensional implicit Navier-Stokes analysis which uses numerical solution of ensemble-averaged Navier-Stokes equations in a nonorthogonal bodyfitted cylindrical-polar coordinate system has been applied to simulation of the internal flow field in solid-propellant rocket motor chambers with segment joints. The calculation procedure incorporates a two-equation (k-epsilon) turbulence model and utilizes a consistently split, linearized block-implicit algorithm for numerical solution of the governing equations. Computations performed to simulate the axisymmetric flow field in the vicinity of the aft field joint in the Space Shuttle SRB using 14,725 grid points show the presence of a region of reversed axial flow near the downstream edge of the slot. Calculations were also performed for two cases involving asymmetric three-dimensional flow in the vicinity of the aft field joint in the SRB using 721,525 grid points to estimate circumferential velocities and pressure gradients at the joint.

  7. Spectrally segmented principal component analysis of hyperspectral imagery for mapping invasive plant species

    Microsoft Academic Search

    F. Tsai; K. Yoshino

    2007-01-01

    Principal component analysis (PCA) is one of the most commonly adopted feature reduction techniques in remote sensing image analysis. However, it may overlook subtle but useful information if directly applied to the analysis of hyperspectral data, especially for the discrimination among different vegetation types. In order to accurately map an invasive plant species (horse tamarind, Leucaena leucocephala) in southern Taiwan

  8. EPA RREL'S MOBILE VOLUME REDUCTION UNIT -- APPLICATIONS ANALYSIS REPORT

    EPA Science Inventory

    The volume reduction unit (VRU) is a pilot-scale, mobile soil washing system designed to remove organic contaminants from the soil through particle size separation and solubilization. The VRU removes contaminants by suspending them in a wash solution and by reducing the volume of...

  9. Volume 7, Issue 3 2011 Article 5 Journal of Quantitative Analysis in

    E-print Network

    Davis, Donald M.

    Volume 7, Issue 3 2011 Article 5 Journal of Quantitative Analysis in Sports Markov Analysis of APBA) "Markov Analysis of APBA, a Baseball Simulation Game," Journal of Quantitative Analysis in Sports: Vol. 7 major league player is represented by a card, which has numbers on it that reflect his performance

  10. Laser and sound scanner for non-contact 3D volume measurement and surface texture analysis

    Microsoft Academic Search

    S S Bhat; D J Smith

    1994-01-01

    Noninvasive three-dimensional measurement of volume and analysis of surface texture is desired in various medical applications, particularly wound healing measurements. The authors present a PC-based noncontact laser scanner for volume measurements, and a sound scanner that can accurately measure volumes and analyse surface textures. The noninvasive laser and sound sensors, which are lightweight, are mounted inverted on an X-Y table

  11. Structural analysis of an RNase T1 variant with an altered guanine binding segment.

    PubMed

    Höschler, K; Hoier, H; Hubner, B; Saenger, W; Orth, P; Hahn, U

    1999-12-17

    The ribonuclease T1 variant 9/5 with a guanine recognition segment, altered from the wild-type amino acid sequence 41-KYNNYE-46 to 41-EFRNWQ-46, has been cocrystallised with the specific inhibitor 2'-GMP. The crystal structure has been refined to a crystallographic R factor of 0.198 at 2.3 A resolution. Despite a size reduction of the binding pocket, pushing the inhibitor outside by 1 A, 2'-GMP is fixed to the primary recognition site due to increased aromatic stacking interactions. The phosphate group of 2'-GMP is located about 4.2 A apart from its position in wild-type ribonuclease T1-2'-GMP complexes, allowing a Ca(2+), coordinating this phosphate group, to enter the binding pocket. The crystallographic data can be aligned with the kinetic characterisation of the variant, showing a reduction of both, guanine affinity and turnover rate. The presence of Ca(2+) was shown to inhibit variant 9/5 and wild-type enzyme to nearly the same extent. PMID:10600381

  12. Photogrammetric Digital Outcrop Model analysis of a segment of the Centovalli Line (Trontano, Italy)

    NASA Astrophysics Data System (ADS)

    Consonni, Davide; Pontoglio, Emanuele; Bistacchi, Andrea; Tunesi, Annalisa

    2015-04-01

    The Centovalli Line is a complex network of brittle faults developing between Domodossola (West) and Locarno (East), where it merges with the Canavese Line (western segment of the Periadriatic Lineament). The Centovalli Line roughly follows the Southern Steep Belt which characterizes the inner or "root" zone of the Penninic and Austroalpine units, which underwent several deformation phases under variable P-T conditions over all the Alpine orogenic history. The last deformation phases in this area developed under brittle conditions, resulting in an array of dextral-reverse subvertical faults with a general E-W trend that partly reactivates and partly crosscuts the metamorphic foliations and lithological boundaries. Here we report on a quantitative digital outcrop model (DOM) study aimed at quantifying the fault zone architecture in a particularly well exposed outcrop near Trontano, at the western edge of the Centovalli Line. The DOM was reconstructed with photogrammetry and allowed to perform a complete characterization of the damage zones and multiple fault cores on both point cloud and textured surfaces models. Fault cores have been characterized in terms of attitude, thickness, and internal distribution of fault rocks (gouge-bearing), including possibly seismogenic localized slip surfaces. In the damage zones, the fracture network has been characterized in terms of fracture intensity (both P10 and P21 on virtual scanlines and scan-areas), fracture attitude, fracture connectivity, etc.

  13. Who Will More Likely Buy PHEV: A Detailed Market Segmentation Analysis

    SciTech Connect

    Lin, Zhenhong [ORNL] [ORNL; Greene, David L [ORNL] [ORNL

    2010-01-01

    Understanding the diverse PHEV purchase behaviors among prospective new car buyers is key for designing efficient and effective policies for promoting new energy vehicle technologies. The ORNL MA3T model developed for the U.S. Department of Energy is described and used to project PHEV purchase probabilities by different consumers. MA3T disaggregates the U.S. household vehicle market into 1458 consumer segments based on region, residential area, driver type, technology attitude, home charging availability and work charging availability and is calibrated to the EIA s Annual Energy Outlook. Simulation results from MA3T are used to identify the more likely PHEV buyers and provide explanations. It is observed that consumers who have home charging, drive more frequently and live in urban area are more likely to buy a PHEV. Early adopters are projected to be more likely PHEV buyers in the early market, but the PHEV purchase probability by the late majority consumer can increase over time when PHEV gradually becomes a familiar product. Copyright Form of EVS25.

  14. Segmentation and Tracking of Adherens Junctions in 3D for the Analysis of Epithelial Tissue Morphogenesis

    PubMed Central

    Cilla, Rodrigo; Mechery, Vinodh; Hernandez de Madrid, Beatriz; Del Signore, Steven; Dotu, Ivan; Hatini, Victor

    2015-01-01

    Epithelial morphogenesis generates the shape of tissues, organs and embryos and is fundamental for their proper function. It is a dynamic process that occurs at multiple spatial scales from macromolecular dynamics, to cell deformations, mitosis and apoptosis, to coordinated cell rearrangements that lead to global changes of tissue shape. Using time lapse imaging, it is possible to observe these events at a system level. However, to investigate morphogenetic events it is necessary to develop computational tools to extract quantitative information from the time lapse data. Toward this goal, we developed an image-based computational pipeline to preprocess, segment and track epithelial cells in 4D confocal microscopy data. The computational pipeline we developed, for the first time, detects the adherens junctions of epithelial cells in 3D, without the need to first detect cell nuclei. We accentuate and detect cell outlines in a series of steps, symbolically describe the cells and their connectivity, and employ this information to track the cells. We validated the performance of the pipeline for its ability to detect vertices and cell-cell contacts, track cells, and identify mitosis and apoptosis in surface epithelia of Drosophila imaginal discs. We demonstrate the utility of the pipeline to extract key quantitative features of cell behavior with which to elucidate the dynamics and biomechanical control of epithelial tissue morphogenesis. We have made our methods and data available as an open-source multiplatform software tool called TTT (http://github.com/morganrcu/TTT) PMID:25884654

  15. Subcortical brain segmentation of two dimensional T1-weighted data sets with FMRIB's Integrated Registration and Segmentation Tool (FIRST)

    PubMed Central

    Amann, Michael; And?lová, Michaela; Pfister, Armanda; Mueller-Lenke, Nicole; Traud, Stefan; Reinhardt, Julia; Magon, Stefano; Bendfeldt, Kerstin; Kappos, Ludwig; Radue, Ernst-Wilhelm; Stippich, Christoph; Sprenger, Till

    2014-01-01

    Brain atrophy has been identified as an important contributing factor to the development of disability in multiple sclerosis (MS). In this respect, more and more interest is focussing on the role of deep grey matter (DGM) areas. Novel data analysis pipelines are available for the automatic segmentation of DGM using three-dimensional (3D) MRI data. However, in clinical trials, often no such high-resolution data are acquired and hence no conclusions regarding the impact of new treatments on DGM atrophy were possible so far. In this work, we used FMRIB's Integrated Registration and Segmentation Tool (FIRST) to evaluate the possibility of segmenting DGM structures using standard two-dimensional (2D) T1-weighted MRI. In a cohort of 70 MS patients, both 2D and 3D T1-weighted data were acquired. The thalamus, putamen, pallidum, nucleus accumbens, and caudate nucleus were bilaterally segmented using FIRST. Volumes were calculated for each structure and for the sum of basal ganglia (BG) as well as for the total DGM. The accuracy and reliability of the 2D data segmentation were compared with the respective results of 3D segmentations using volume difference, volume overlap and intra-class correlation coefficients (ICCs). The mean differences for the individual substructures were between 1.3% (putamen) and ?25.2% (nucleus accumbens). The respective values for the BG were ?2.7% and for DGM 1.3%. Mean volume overlap was between 89.1% (thalamus) and 61.5% (nucleus accumbens); BG: 84.1%; DGM: 86.3%. Regarding ICC, all structures showed good agreement with the exception of the nucleus accumbens. The results of the segmentation were additionally validated through expert manual delineation of the caudate nucleus and putamen in a subset of the 3D data. In conclusion, we demonstrate that subcortical segmentation of 2D data are feasible using FIRST. The larger subcortical GM structures can be segmented with high consistency. This forms the basis for the application of FIRST in large 2D MRI data sets of clinical trials in order to determine the impact of therapeutic interventions on DGM atrophy in MS. PMID:25610766

  16. Microstructural analysis of pineal volume using trueFISP imaging

    PubMed Central

    Bumb, Jan M; Brockmann, Marc A; Groden, Christoph; Nolte, Ingo

    2013-01-01

    AIM: To determine the spectrum of pineal microstructures (solid/cystic parts) in a large clinical population using a high-resolution 3D-T2-weighted sequence. METHODS: A total of 347 patients enrolled for cranial magnetic resonance imaging were randomly included in this study. Written informed consent was obtained from all patients. The exclusion criteria were artifacts or mass lesions prohibiting evaluation of the pineal gland in any of the sequences. True-FISP-3D-imaging (1.5-T, isotropic voxel 0.9 mm) was performed in 347 adults (55.4 ± 18.1 years). Pineal gland volume (PGV), cystic volume, and parenchyma volume (cysts excluded) were measured manually. RESULTS: Overall, 40.3% of pineal glands were cystic. The median PGV was 54.6 mm3 (78.33 ± 89.0 mm3), the median cystic volume was 5.4 mm3 (15.8 ± 37.2 mm3), and the median parenchyma volume was 53.6 mm3 (71.9 ± 66.7 mm3). In cystic glands, the standard deviation of the PGV was substantially higher than in solid glands (98% vs 58% of the mean). PGV declined with age (r = -0.130, P = 0.016). CONCLUSION: The high interindividual volume variation is mainly related to cysts. Pineal parenchyma volume decreased slightly with age, whereas gender-related effects appear to be negligible. PMID:23671752

  17. A STANDARD PROCEDURE FOR COST ANALYSIS OF POLLUTION CONTROL OPERATIONS. VOLUME II. APPENDICES

    EPA Science Inventory

    Volume I is a user guide for a standard procedure for the engineering cost analysis of pollution abatement operations and processes. The procedure applies to projects in various economic sectors: private, regulated, and public. Volume II, the bulk of the document, contains 11 app...

  18. Cell Volume to Aid Analysis and Technique of Somatic Cell Counts in Milk

    Microsoft Academic Search

    R. F. Sheldrake; R. J. T. Hoare; V. E. Woodhouse; G. D. McGregor

    1977-01-01

    In conjunction with a Coulter Coun- ter, somatic cells in milk were sized by electronic analysis. Quarter milk from cows with mastitis had a cell volume peak with a modal cell volume of 102\\/23 while milk from healthy quarters had no peak. Bulk milks with a peak had higher cell counts than milks where there was no peak. Dimensions of

  19. Complex trait analysis of the mouse striatum: independent QTLs modulate volume and neuron number

    Microsoft Academic Search

    Glenn D. Rosen; Robert W. Williams

    2001-01-01

    BACKGROUND: The striatum plays a pivotal role in modulating motor activity and higher cognitive function. We analyzed variation in striatal volume and neuron number in mice and initiated a complex trait analysis to discover polymorphic genes that modulate the structure of the basal ganglia. RESULTS: Brain weight, brain and striatal volume, neuron-packing density and number were estimated bilaterally using unbiased

  20. The structure of vortex tube segments in fluid turbulence

    NASA Astrophysics Data System (ADS)

    Wang, Lipo

    2011-12-01

    Geometrical description of the flow fields is an important direction to understand the physics of turbulence. Recently several new analysis approaches addressing the entire field properties have been developed, such as dissipation element analysis for the scalar fields and streamtube segment analysis (J. Fluid Mech. 2010, 648: 183-203) for the velocity vector field. By decomposing into a fundamental structure, i.e. stream-tube segments, the velocity field can be understood from the statistics of these relative simple units. Similar idea can be adopted to analyze the vorticity field. The classic concept of vortex tube has been remaining as a topic of essential importance in many aspects. However, the vortex tube structure is not complete to represent the entire turbulent fields, because of its ambiguous definition and small volume portion. This work presents tentatively the vorticitytube segment structure to overcome the existing deficiency. Vorticitytube segments reveal an inherent topology of turbulence vorticity fields. Based on statistics conditioned on different vorticitytube segments, some problems can be newly understood, such as the enstrophy production. Results hereof may also serve for turbulence modeling.

  1. Fast prostate segmentation for brachytherapy based on joint fusion of images and labels

    NASA Astrophysics Data System (ADS)

    Nouranian, Saman; Ramezani, Mahdi; Mahdavi, S. Sara; Spadinger, Ingrid; Morris, William J.; Salcudean, Septimiu E.; Abolmaesumi, Purang

    2014-03-01

    Brachytherapy as one of the treatment methods for prostate cancer takes place by implantation of radioactive seeds inside the gland. The standard of care for this treatment procedure is to acquire transrectal ultrasound images of the prostate which are segmented in order to plan the appropriate seed placement. The segmentation process is usually performed either manually or semi-automatically and is associated with subjective errors because the prostate visibility is limited in ultrasound images. The current segmentation process also limits the possibility of intra-operative delineation of the prostate to perform real-time dosimetry. In this paper, we propose a computationally inexpensive and fully automatic segmentation approach that takes advantage of previously segmented images to form a joint space of images and their segmentations. We utilize joint Independent Component Analysis method to generate a model which is further employed to produce a probability map of the target segmentation. We evaluate this approach on the transrectal ultrasound volume images of 60 patients using a leave-one-out cross-validation approach. The results are compared with the manually segmented prostate contours that were used by clinicians to plan brachytherapy procedures. We show that the proposed approach is fast with comparable accuracy and precision to those found in previous studies on TRUS segmentation.

  2. Image segmentation with cyclic load balanced parallel Fuzzy C - Means cluster analysis

    Microsoft Academic Search

    Mogana Vadiveloo; Rosni Abdullah; Mandava Rajeswari; Ahmad Adel Abu-Shareha

    2011-01-01

    This paper proposes a cyclic load balancing strategy to parallel Fuzzy C-Means cluster analysis algorithm. The problem is to minimize the total time cost and maximize the parallel processing efficiency when a subset of clusters is distributed over a set of processors cores on shared memory architecture. The parallel Fuzzy C - Means (FCM) cluster analysis algorithm is composed by

  3. Conjoint Analysis of Study Abroad Preferences: Key Attributes, Segments and Implications for Increasing Student Participation

    ERIC Educational Resources Information Center

    Garver, Michael S.; Divine, Richard L.

    2008-01-01

    An adaptive conjoint analysis was performed on the study abroad preferences of a sample of undergraduate college students. The results indicate that trip location, cost, and time spent abroad are the three most important determinants of student preference for different study abroad trip scenarios. The analysis also uncovered four different study…

  4. The feasibility of a video-based motion analysis system in measuring the segmental movements between upper and lower cervical spine

    Microsoft Academic Search

    Shyi-Kuen Wu; Howard H. C. Lan; Li-Chieh Kuo; Sen-Wei Tsai; Chiung-Ling Chen; Fong-Chin Su

    2007-01-01

    The evaluation of the range of motion (ROM) and static posture in the cervical spine are important in physical examination. Despite offering dynamic assessment without radiation, the video-based motion analysis system has not yet been applied to measure the cervical segmental movements. The purposes of this study were to develop a neck model to differentiate the movements and posture between

  5. Validity of segmental multiple-frequency bioelectrical impedance analysis to estimate body composition of adults across a range of body mass indexes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Objective: Compare estimates of body composition using segmental, multiple frequency bioelectrical impedance analysis (MF-BIA) with dual x-ray absorptiometry (DXA) in healthy adults across a range of body mass index (BMI). Methods: Percent body fat (%BF), fat-mass (FM), and fat-free mass (FFM) asses...

  6. Genetic characterization of Indian peste des petits ruminants virus (PPRV) by sequencing and phylogenetic analysis of fusion protein and nucleoprotein gene segments

    Microsoft Academic Search

    N. Kerur; M. K. Jhala; C. G. Joshi

    2008-01-01

    Peste des petits ruminants (PPR) is an important viral disease of sheep and goats, endemic in India. The study was undertaken to characterize the local PPRV by sequencing fusion (F) protein and nucleoprotein (N) gene segments and phylogenetic analysis, so as to focus on genetic variation in the field viruses. Selected regions of PPRV genome were amplified from clinical samples

  7. Nucleotide sequencing analysis of the swine 433-kb genomic segment located between the non-classical and classical SLA class I gene clusters

    Microsoft Academic Search

    Atsuko Shigenari; Asako Ando; Christine Renard; Patrick Chardon; Takashi Shiina; Jerzy K. Kulski; Hiroshi Yasue; Hidetoshi Inoko

    2004-01-01

    Genome analysis of the swine leukocyte antigen ( SLA) region is needed to obtain information on the MHC genomic sequence similarities and differences between the swine and human, given the possible use of swine organs for xenotransplantation. Here, the genomic sequences of a 433-kb segment located between the non-classical and classical SLA class I gene clusters were determined and analyzed for

  8. Lung tumor segmentation in PET images using graph cuts.

    PubMed

    Ballangan, Cherry; Wang, Xiuying; Fulham, Michael; Eberl, Stefan; Feng, David Dagan

    2013-03-01

    The aim of segmentation of tumor regions in positron emission tomography (PET) is to provide more accurate measurements of tumor size and extension into adjacent structures, than is possible with visual assessment alone and hence improve patient management decisions. We propose a segmentation energy function for the graph cuts technique to improve lung tumor segmentation with PET. Our segmentation energy is based on an analysis of the tumor voxels in PET images combined with a standardized uptake value (SUV) cost function and a monotonic downhill SUV feature. The monotonic downhill feature avoids segmentation leakage into surrounding tissues with similar or higher PET tracer uptake than the tumor and the SUV cost function improves the boundary definition and also addresses situations where the lung tumor is heterogeneous. We evaluated the method in 42 clinical PET volumes from patients with non-small cell lung cancer (NSCLC). Our method improves segmentation and performs better than region growing approaches, the watershed technique, fuzzy-c-means, region-based active contour and tumor customized downhill. PMID:23146420

  9. Cross Profile and Volume Analysis of Bahram Valles on Mars

    NASA Astrophysics Data System (ADS)

    Kereszturi, A.

    2005-03-01

    We analysed cross section profiles of Bahram Valles on Mars and the connection between its shape, the surrrounding terrain and the probable erosional processes, and estimated the volume of transported material during its formation.

  10. Fast leukocyte image segmentation using shadowed sets.

    PubMed

    Mohapatra, Subrajeet; Patra, Dipti; Kumar, Kundan

    2012-01-01

    Leukocyte image segmentation acts as the foundation for all automated image based hematological disease recognition systems. Perfection in image segmentation is a necessary condition for improving the diagnostic accuracy in automated cytology. Even though much effort has been put in developing suitable segmentation routines, the problem still remains open in areas like pathological imaging. Clustering is an essential image segmentation procedure which segments an image into desired regions. This paper introduces a novel Shadowed C-means (SCM) clustering approach towards leukocyte segmentation in blood microscopic images. The segmented nucleus and cytoplasm of a leukocyte can be used for feature extraction which can lead to acute leukemia detection. Absence of parameter tuning in SCM with acceptable segmentation performance gives the proposed scheme an edge over standard cluster based segmentation techniques. Comparative analysis reveals that the proposed algorithm is fast and robust in segmenting stained blood microscopic images in the presence of outliers. PMID:22436298

  11. Automated analysis of high-throughput B-cell sequencing data reveals a high frequency of novel immunoglobulin V gene segment alleles.

    PubMed

    Gadala-Maria, Daniel; Yaari, Gur; Uduman, Mohamed; Kleinstein, Steven H

    2015-02-24

    Individual variation in germline and expressed B-cell immunoglobulin (Ig) repertoires has been associated with aging, disease susceptibility, and differential response to infection and vaccination. Repertoire properties can now be studied at large-scale through next-generation sequencing of rearranged Ig genes. Accurate analysis of these repertoire-sequencing (Rep-Seq) data requires identifying the germline variable (V), diversity (D), and joining (J) gene segments used by each Ig sequence. Current V(D)J assignment methods work by aligning sequences to a database of known germline V(D)J segment alleles. However, existing databases are likely to be incomplete and novel polymorphisms are hard to differentiate from the frequent occurrence of somatic hypermutations in Ig sequences. Here we develop a Tool for Ig Genotype Elucidation via Rep-Seq (TIgGER). TIgGER analyzes mutation patterns in Rep-Seq data to identify novel V segment alleles, and also constructs a personalized germline database containing the specific set of alleles carried by a subject. This information is then used to improve the initial V segment assignments from existing tools, like IMGT/HighV-QUEST. The application of TIgGER to Rep-Seq data from seven subjects identified 11 novel V segment alleles, including at least one in every subject examined. These novel alleles constituted 13% of the total number of unique alleles in these subjects, and impacted 3% of V(D)J segment assignments. These results reinforce the highly polymorphic nature of human Ig V genes, and suggest that many novel alleles remain to be discovered. The integration of TIgGER into Rep-Seq processing pipelines will increase the accuracy of V segment assignments, thus improving B-cell repertoire analyses. PMID:25675496

  12. MIXTURE PRINCIPAL COMPONENT ANALYSIS FOR DISTRIBUTION VOLUME PARAMETRIC IMAGING IN BRAIN PET STUDIES

    E-print Network

    Liu, K. J. Ray

    . For quantitative analysis of neuroreceptor PET studies, compartmental model-based approaches are the most widely of mixture Principal Compo- nent Analysis (mPCA). Distinguishing specific binding and non-specific bindingMIXTURE PRINCIPAL COMPONENT ANALYSIS FOR DISTRIBUTION VOLUME PARAMETRIC IMAGING IN BRAIN PET

  13. Volume 2, Issue 4 2006 Article 1 Journal of Quantitative Analysis in

    E-print Network

    Redner, Sidney

    analysis of the results of all sports competitions in five major sports leagues in England and the UnitedVolume 2, Issue 4 2006 Article 1 Journal of Quantitative Analysis in Sports Parity, Sidney (2006) "Parity and Predictability of Competitions," Journal of Quantitative Analysis in Sports

  14. Adjunctive Manual Thrombus Aspiration during ST-Segment Elevation Myocardial Infarction: A Meta-Analysis of Randomized Controlled Trials

    PubMed Central

    Deng, Song-Bai; Wang, Jing; Xiao, Jun; Wu, Ling; Jing, Xiao-Dong; Yan, Yu-Ling; Du, Jian-Lin; Liu, Ya-Jie; She, Qiang

    2014-01-01

    Objective The aim of this study was to synthesize evidence by examining the effects of manual thrombus aspiration on clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI). Methods and Results A total of 26 randomized controlled trials (RCTs), enrolling 11,780 patients, with 5,869 patients randomized to manual thrombus aspiration and 5,911 patients randomized to conventional percutaneous coronary intervention (PCI), were included in the meta-analysis. Separate clinical outcome analyses were based on different follow-up periods. There were no statistically reductions in the incidences of mortality (risk ratio [RR], 0.86 [95% confidence interval [CI]: 0.73 to 1.02]), reinfarction (RR, 0.62 [CI, 0.31 to 1.32]) or target vessel revascularization (RR, 0.89 [CI, 0.75 to 1.05]) in the manual thrombus aspiration arm at 12 to 24 months of follow-up. The composite major adverse cardiac events (MACEs) outcomes were significantly lower in the manual thrombus aspiration arm over the long-term follow-up (RR, 0.76 [CI, 0.63 to 0.91]). A lower incidence of reinfarction was observed in the hospital to 30 days (RR, 0.59 [CI, 0.37 to 0.92]). Conclusion The present meta-analysis suggested that there was no evidence that using manual thrombus aspiration in patients with STEMI could provide distinct benefits in long-term clinical outcomes. PMID:25405874

  15. Markov models of genome segmentation

    NASA Astrophysics Data System (ADS)

    Thakur, Vivek; Azad, Rajeev K.; Ramaswamy, Ram

    2007-01-01

    We introduce Markov models for segmentation of symbolic sequences, extending a segmentation procedure based on the Jensen-Shannon divergence that has been introduced earlier. Higher-order Markov models are more sensitive to the details of local patterns and in application to genome analysis, this makes it possible to segment a sequence at positions that are biologically meaningful. We show the advantage of higher-order Markov-model-based segmentation procedures in detecting compositional inhomogeneity in chimeric DNA sequences constructed from genomes of diverse species, and in application to the E. coli K12 genome, boundaries of genomic islands, cryptic prophages, and horizontally acquired regions are accurately identified.

  16. ICDAR 2003 Page Segmentation Competition

    Microsoft Academic Search

    Apostolos Antonacopoulos; Basilios Gatos; Dimosthenis Karatzas

    2003-01-01

    There is a significant need to objectively evaluate layout analysis (page segmentation and region classification) methods. This paper describes the Page Segmentation Competition (modus operandi, dataset and evaluation criteria) held in the context of ICDAR2003 and presents the results of the evaluation of the candidate methods. The main objective of the competition was to evaluate such methods using scanned documents

  17. Earth Observatory Satellite system definition study. Report 5: System design and specifications. Volume 4: Mission peculiar spacecraft segment and module specifications

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The specifications for the Earth Observatory Satellite (EOS) peculiar spacecraft segment and associated subsystems and modules are presented. The specifications considered include the following: (1) wideband communications subsystem module, (2) mission peculiar software, (3) hydrazine propulsion subsystem module, (4) solar array assembly, and (5) the scanning spectral radiometer.

  18. IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE, VOL. 20, NO. 5, MAY 1998 481 Segmenting Images

    E-print Network

    Lee, Chun Man "Thomas"

    is based on Rissanen's minimum description length (MDL) principle and consists of two components: i) an MDL. The proposed segmentation procedure is based on Rissanen's minimum description length (MDL) principle [22, with promising results. Index Terms--Correlated noise, image segmentation, merging algorithm, minimum description

  19. Dynamic analysis of the activley controlled segmented mirror of the W. M. Keck ten-meter telescope

    Microsoft Academic Search

    Jean-Noel Aubrun; Kenneth R. Lorell; Terry S. Mast; J. Nelson

    1987-01-01

    The W. M. Keck Observatory and Telescope are presently under construction on Mauna Kea, Hawaii. When completed in 1990, the telescope will be the world's largest instrument for astronomical observations at visible and infrared wavelengths. The primary mirror has a diameter of 10 m and consists of a mosaic of 36 hexagonal segments, with the orientation of each segment actively

  20. Improved Inference in Bayesian Segmentation Using Monte Carlo Sampling: Application to Hippocampal Subfield Volumetry

    PubMed Central

    Iglesias, Juan Eugenio; Sabuncu, Mert Rory; Leemput, Koen Van

    2013-01-01

    Many segmentation algorithms in medical image analysis use Bayesian modeling to augment local image appearance with prior anatomical knowledge. Such methods often contain a large number of free parameters that are first estimated and then kept fixed during the actual segmentation process. However, a faithful Bayesian analysis would marginalize over such parameters, accounting for their uncertainty by considering all possible values they may take. Here we propose to incorporate this uncertainty into Bayesian segmentation methods in order to improve the inference process. In particular, we approximate the required marginalization over model parameters using computationally efficient Markov chain Monte Carlo techniques. We illustrate the proposed approach using a recently developed Bayesian method for the segmentation of hippocampal subfields in brain MRI scans, showing a significant improvement in an Alzheimer’s disease classification task. As an additional benefit, the technique also allows one to compute informative “error bars” on the volume estimates of individual structures. PMID:23773521

  1. A new CAD mesh segmentation method, based on curvature tensor analysis

    E-print Network

    Lavoué, Guillaume

    and particularly optimized triangulated CAD meshes. The algorithm is based on the curvature tensor field analysis-meshes by a mixed approach vertex-triangle, J WSCG 2004;12(2):245­52] and which decomposes the object into near´seau National de Recherche en Te´le´communications). The objective is the low bandwidth transmission of CAD

  2. Probabilistic Segmentation and Analysis of Horizontal Cells Vebjorn Ljosa and Ambuj K. Singh

    E-print Network

    California at Santa Barbara, University of

    ) develop and respond to injuries and other stimuli quite differently than neurons in vivo (in tissue). One of acquisition and analysis. One approach to understanding the vast complexity of the brain is to study and ganglion cells before they are finally passed through the optic nerve into the rest of the brain

  3. Registration-based segmentation of murine 4D cardiac micro-CT data using symmetric normalization

    PubMed Central

    Clark, Darin; Badea, Alexandra; Liu, Yilin; Johnson, G. Allan; Badea, Cristian T.

    2013-01-01

    Micro-CT can play an important role in preclinical studies of cardiovascular disease because of its high spatial and temporal resolution. Quantitative analysis of 4D cardiac images requires segmentation of the cardiac chambers at each time point, an extremely time consuming process if done manually. To improve throughput this study proposes a pipeline for registration-based segmentation and functional analysis of 4D cardiac micro-CT data in the mouse. Following optimization and validation using simulations, the pipeline was applied to in vivo cardiac micro-CT data corresponding to 10 cardiac phases acquired in C57BL/6 mice (n = 5). After edge-preserving smoothing with a novel adaptation of 4D bilateral filtration, one phase within each cardiac sequence was manually segmented. Deformable registration was used to propagate these labels to all other cardiac phases for segmentation. The volumes of each cardiac chamber were calculated and used to derive stroke volume, ejection fraction, cardiac output, and cardiac index. Dice coefficients and volume accuracies were used to compare manual segmentations of two additional phases with their corresponding propagated labels. Both measures were, on average, >0.90 for the left ventricle and >0.80 for the myocardium, the right ventricle, and the right atrium, consistent with trends in inter- and intra-segmenter variability. Segmentation of the left atrium was less reliable. On average, the functional metrics of interest were underestimated by 6.76% or more due to systematic label propagation errors around atrioventricular valves; however, execution of the pipeline was 80% faster than performing analogous manual segmentation of each phase. PMID:22971564

  4. Adaptive Breast Radiation Therapy Using Modeling of Tissue Mechanics: A Breast Tissue Segmentation Study

    SciTech Connect

    Juneja, Prabhjot, E-mail: Prabhjot.Juneja@icr.ac.uk [Joint Department of Physics, Institute of Cancer Research, Sutton (United Kingdom)] [Joint Department of Physics, Institute of Cancer Research, Sutton (United Kingdom); Harris, Emma J. [Joint Department of Physics, Institute of Cancer Research, Sutton (United Kingdom)] [Joint Department of Physics, Institute of Cancer Research, Sutton (United Kingdom); Kirby, Anna M. [Department of Academic Radiotherapy, Royal Marsden National Health Service Foundation Trust, Sutton (United Kingdom)] [Department of Academic Radiotherapy, Royal Marsden National Health Service Foundation Trust, Sutton (United Kingdom); Evans, Philip M. [Joint Department of Physics, Institute of Cancer Research, Sutton (United Kingdom)] [Joint Department of Physics, Institute of Cancer Research, Sutton (United Kingdom)

    2012-11-01

    Purpose: To validate and compare the accuracy of breast tissue segmentation methods applied to computed tomography (CT) scans used for radiation therapy planning and to study the effect of tissue distribution on the segmentation accuracy for the purpose of developing models for use in adaptive breast radiation therapy. Methods and Materials: Twenty-four patients receiving postlumpectomy radiation therapy for breast cancer underwent CT imaging in prone and supine positions. The whole-breast clinical target volume was outlined. Clinical target volumes were segmented into fibroglandular and fatty tissue using the following algorithms: physical density thresholding; interactive thresholding; fuzzy c-means with 3 classes (FCM3) and 4 classes (FCM4); and k-means. The segmentation algorithms were evaluated in 2 stages: first, an approach based on the assumption that the breast composition should be the same in both prone and supine position; and second, comparison of segmentation with tissue outlines from 3 experts using the Dice similarity coefficient (DSC). Breast datasets were grouped into nonsparse and sparse fibroglandular tissue distributions according to expert assessment and used to assess the accuracy of the segmentation methods and the agreement between experts. Results: Prone and supine breast composition analysis showed differences between the methods. Validation against expert outlines found significant differences (P<.001) between FCM3 and FCM4. Fuzzy c-means with 3 classes generated segmentation results (mean DSC = 0.70) closest to the experts' outlines. There was good agreement (mean DSC = 0.85) among experts for breast tissue outlining. Segmentation accuracy and expert agreement was significantly higher (P<.005) in the nonsparse group than in the sparse group. Conclusions: The FCM3 gave the most accurate segmentation of breast tissues on CT data and could therefore be used in adaptive radiation therapy-based on tissue modeling. Breast tissue segmentation methods should be used with caution in patients with sparse fibroglandular tissue distribution.

  5. Reliability of segmental accelerations measured using a new wireless gait analysis system

    Microsoft Academic Search

    Justin J. Kavanagh; Steven Morrison; Daniel A. James; Rod Barrett

    2006-01-01

    The purpose of this study was to determine the inter- and intra-examiner reliability, and stride-to-stride reliability, of an accelerometer-based gait analysis system which measured 3D accelerations of the upper and lower body during self-selected slow, preferred and fast walking speeds. Eight subjects attended two testing sessions in which accelerometers were attached to the head, neck, lower trunk, and right shank.

  6. A system for the quantitative analysis of bone metastases by image segmentation

    SciTech Connect

    Erdi, Y.E.; Humm, J.L.; Yeung, H. [Memorial Sloan-Kettering Cancer Center, New York, NY (United States)] [and others

    1996-12-31

    Preliminary evidence indicates that the fraction of bone containing metastatic lesions is a strong prognostic indicator of survival longevity for prostate and breast cancer. To quantify metastatic lesions, the most common method is to visually inspect the fraction of each bone involvement and determine the percent involvement by drawing region-of-interest. However, this approach is time-consuming, subjective and dependent upon individual interpretation. To overcome these problems, a semi-automated region-growing program was developed for the quantitation of metastases from planar bone scans. The program then computes the fraction of lesion involvement in each bone based on look-up-tables containing the relationship of bone weight with: race, sex, height, and age. The bone metastases analysis system has been used on 11 scans from 6 patients. The correlation was high (r=0.83) between conventional (manually drawn region-of-interest) and this analysis system. Bone metastases analysis results in consistently lower estimates of fractional involvement in bone compared to the conventional region-of-interest drawing or visual estimation method. This is due to the apparent broadening of objects at and below the limits of resolution of the gamma camera. Bone metastases (BMets) analysis system reduces the delineation and quantitation time of lesions by at least 2 compared to manual region-of-interest drawing. The objectivity of this technique allows the detection of small variations in follow-up patient scans for which manual region-of-interest method may fail, due to performance variability of the user. This method preserves the diagnostic skills of the nuclear medicine physician to select which bony structures contain lesions, yet combines it with an objective delineation of the lesion.

  7. Visualizing and Segmenting Large Volumetric Data Sets

    Microsoft Academic Search

    Steven Senger

    1999-01-01

    Current systems for segmenting and visualizing volumetric data sets characteristically require the user to possess a technical sophistication in volume visualization techniques, thus restricting the potential audience of users. As large volumetric data sets become more common, segmentation and visualization tools need to deemphasize the technical aspects of visualization and let users exploit their content knowledge of the data set.

  8. Complete Genomic Sequence and Comparative Analysis of the Genome Segments of Sweet Potato Chlorotic Stunt Virus in China

    PubMed Central

    Qin, Yanhong; Wang, Li; Zhang, Zhenchen; Qiao, Qi; Zhang, Desheng; Tian, Yuting; Wang, Shuang; Wang, Yongjiang; Yan, Zhaoling

    2014-01-01

    Background Sweet potato chlorotic stunt virus (family Closteroviridae, genus Crinivirus) features a large bipartite, single-stranded, positive-sense RNA genome. To date, only three complete genomic sequences of SPCSV can be accessed through GenBank. SPCSV was first detected from China in 2011, only partial genomic sequences have been determined in the country. No report on the complete genomic sequence and genome structure of Chinese SPCSV isolates or the genetic relation between isolates from China and other countries is available. Methodology/Principal Findings The complete genomic sequences of five isolates from different areas in China were characterized. This study is the first to report the complete genome sequences of SPCSV from whitefly vectors. Genome structure analysis showed that isolates of WA and EA strains from China have the same coding protein as isolates Can181-9 and m2-47, respectively. Twenty cp genes and four RNA1 partial segments were sequenced and analyzed, and the nucleotide identities of complete genomic, cp, and RNA1 partial sequences were determined. Results indicated high conservation among strains and significant differences between WA and EA strains. Genetic analysis demonstrated that, except for isolates from Guangdong Province, SPCSVs from other areas belong to the WA strain. Genome organization analysis showed that the isolates in this study lack the p22 gene. Conclusions/Significance We presented the complete genome sequences of SPCSV in China. Comparison of nucleotide identities and genome structures between these isolates and previously reported isolates showed slight differences. The nucleotide identities of different SPCSV isolates showed high conservation among strains and significant differences between strains. All nine isolates in this study lacked p22 gene. WA strains were more extensively distributed than EA strains in China. These data provide important insights into the molecular variation and genomic structure of SPCSV in China as well as genetic relationships among isolates from China and other countries. PMID:25170926

  9. Analysis of Combined Mass- and Volume-Transducing Sensor Arrays

    SciTech Connect

    Wise, Barry M. (EIGENVECTOR RESEARCH, INC); Gallagher, Neal B. (EIGENVECTOR RESEARCH, INC); Grate, Jay W. (BATTELLE (PACIFIC NW LAB))

    2003-09-01

    In prior work it was shown that both mass and volume transducing sensor arrays with polymer coatings can be modeled with a Classical Least Squares (CLS) type formulation. Given a response vector, this method allows one to solve simultaneously for the vapor descriptors and concentration, even for previously unseen analytes. It has also been shown that Inverse Least Squares (ILS) models can be used in this system to estimate vapor descriptors. A more challenging task is to extract vapor descriptors from sensor arrays which respond to both mass and volume changes simultaneously. This problem is important because Surface Acoustic Wave (SAW) sensors, and probably other types of sensors such as Flexural Plate Wave (FPW) sensors, respond via both mass and volume mechanisms. In this work we show how a closed form solution can be obtained to a slightly simplified mass and volume sensitive system. This solution can be further refined with direct optimization using the full modeling equations. Simulations are performed to evaluate the accuracy of the approximate and refined solutions. This is compared to the accuracy of the known descriptors.

  10. Learning static object segmentation from motion segmentation

    E-print Network

    Ross, Michael G. (Michael Gregory), 1975-

    2005-01-01

    This thesis describes the SANE (Segmentation According to Natural Examples) algorithm for learning to segment objects in static images from video data. SANE uses background subtraction to find the segmentation of moving ...

  11. An approach to dissecting the congenitally malformed heart in the forensic autopsy: the value of sequential segmental analysis.

    PubMed

    Horn, K D; Devine, W A

    2001-12-01

    The demonstration of congenital heart disease at autopsy necessitates the careful preservation and examination of the heart, the vessels, and their connections. Techniques preserving these connections and using a reproducible and systematic approach are preferred. The Rokitansky method of organ block dissection, in combination with a system of heart examination termed sequential segmental analysis, provides such an approach. This study is based on the examination of heart specimens accessioned into the Frank E. Sherman, M.D., and Cora C. Lenox, M.D., Heart Museum (containing approximately 2400 specimens) of the Pathology Department, Children's Hospital of Pittsburgh. Specimens received in consultation during a 25-year period from hospitals and coroners'/medical examiners' offices were examined, and the corresponding reports were reviewed. Of 46 total heart specimens examined (1975-1999), 29 (63%) were dissected properly or left intact for dissection at Children's Hospital of Pittsburgh, and 17 (37%) were incorrectly dissected for the demonstration of congenital heart disease. Of these 17 cases, 11 (24%) displayed dissection errors, which did not hinder a complete diagnosis, 3 cases (6.5%) had errors that enabled only an incomplete diagnosis, and in 3 cases (6.5%), no diagnosis of congenital heart disease could be made. Dissection mistakes and means of avoiding them are discussed. Review of medical and family history, external and internal examination, and a reproducible and sequential method of examining the heart and its connections enables documentation of even the most complex cardiovascular anomalies. PMID:11764911

  12. Metric Learning to Enhance Hyperspectral Image Segmentation

    NASA Technical Reports Server (NTRS)

    Thompson, David R.; Castano, Rebecca; Bue, Brian; Gilmore, Martha S.

    2013-01-01

    Unsupervised hyperspectral image segmentation can reveal spatial trends that show the physical structure of the scene to an analyst. They highlight borders and reveal areas of homogeneity and change. Segmentations are independently helpful for object recognition, and assist with automated production of symbolic maps. Additionally, a good segmentation can dramatically reduce the number of effective spectra in an image, enabling analyses that would otherwise be computationally prohibitive. Specifically, using an over-segmentation of the image instead of individual pixels can reduce noise and potentially improve the results of statistical post-analysis. In this innovation, a metric learning approach is presented to improve the performance of unsupervised hyperspectral image segmentation. The prototype demonstrations attempt a superpixel segmentation in which the image is conservatively over-segmented; that is, the single surface features may be split into multiple segments, but each individual segment, or superpixel, is ensured to have homogenous mineralogy.

  13. Earth Observatory Satellite system definition study. Report 5: System design and specifications. Volume 3: General purpose spacecraft segment and module specifications

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The specifications for the Earth Observatory Satellite (EOS) general purpose aircraft segment are presented. The satellite is designed to provide attitude stabilization, electrical power, and a communications data handling subsystem which can support various mission peculiar subsystems. The various specifications considered include the following: (1) structures subsystem, (2) thermal control subsystem, (3) communications and data handling subsystem module, (4) attitude control subsystem module, (5) power subsystem module, and (6) electrical integration subsystem.

  14. Segmentation and Tracking of Multiple Moving Objects for Intelligent Video Analysis

    NASA Astrophysics Data System (ADS)

    Xu, L.-Q.; Landabaso, J. L.; Lei, B.

    In recent years, there has been considerable interest in visual surveillance of a wide range of indoor and outdoor sites by various parties. This is manifested by the widespread and unabated deployment of CCTV cameras in public and private areas. In particular, the increasing connectivity of broadband wired and wireless IP networks, and the emergence of IP-CCTV systems with smart sensors, enabling centralised or distributed remote monitoring, have further fuelled this trend. It is not uncommon nowadays to see a bank of displays in an organisation showing the activities of dozens of surveillance sites simultaneously. However, the limitations and deficiencies, together with the costs associated with human operators in monitoring the overwhelming video sources, have created urgent demands for automated video analysis solutions. Indeed, the ability of a system to automatically analyse and interpret visual scenes is of increasing importance to decision making, offering enormous business opportunities in the sector of information and communications technologies.

  15. Compatibility of segmented thermoelectric generators

    NASA Technical Reports Server (NTRS)

    Snyder, J.; Ursell, T.

    2002-01-01

    It is well known that power generation efficiency improves when materials with appropriate properties are combined either in a cascaded or segmented fashion across a temperature gradient. Past methods for determining materials used in segmentation weremainly concerned with materials that have the highest figure of merit in the temperature range. However, the example of SiGe segmented with Bi2Te3 and/or various skutterudites shows a marked decline in device efficiency even though SiGe has the highest figure of merit in the temperature range. The origin of the incompatibility of SiGe with other thermoelectric materials leads to a general definition of compatibility and intrinsic efficiency. The compatibility factor derived as = (Jl+zr - 1) a is a function of only intrinsic material properties and temperature, which is represented by a ratio of current to conduction heat. For maximum efficiency the compatibility factor should not change with temperature both within a single material, and in the segmented leg as a whole. This leads to a measure of compatibility not only between segments, but also within a segment. General temperature trends show that materials are more self compatible at higher temperatures, and segmentation is more difficult across a larger -T. The compatibility factor can be used as a quantitative guide for deciding whether a material is better suited for segmentation orcascading. Analysis of compatibility factors and intrinsic efficiency for optimal segmentation are discussed, with intent to predict optimal material properties, temperature interfaces, and/or currentheat ratios.

  16. Conferences on Orthodontics Advances in Science and Technology, Monterey, September 2002 (in 3D Visualization of the Craniofacial Patient: Volume Segmentation, Data

    E-print Network

    Shahabi, Cyrus

    , memon, jamesmah} @usc.edu Keywords: 3D Visualization, volume rendering, CT, dentition models, jaw in this area, with a previous method described using spherical markers placed on the skeleton and dentition

  17. A phonetic-context controlled strategy for segmentation and phonetic labeling of speech

    Microsoft Academic Search

    P. Mermelstein

    1975-01-01

    This paper considers a sequential strategy for acoustic-phonetic speech analysis. Each analysis process is applied to an appropriately labeled speech segment and results in a possible sub-segmentation of the original segment. The segments resulting from the analysis are labeled according to the analysis results. The advantages of the strategy are that no more segments are considered than those actually differentiated

  18. Industrial process heat data analysis and evaluation. Volume 1

    SciTech Connect

    Lewandowski, A; Gee, R; May, K

    1984-07-01

    The Solar Energy Research Institute (SERI) has modeled seven of the Department of Energy (DOE) sponsored solar Industrial Process Heat (IPH) field experiments and has generated thermal performance predictions for each project. Additionally, these performance predictions have been compared with actual performance measurements taken at the projects. Predictions were generated using SOLIPH, an hour-by-hour computer code with the capability for modeling many types of solar IPH components and system configurations. Comparisons of reported and predicted performance resulted in good agreement when the field test reliability and availability was high. Volume I contains the main body of the work: objective, model description, site configurations, model results, data comparisons, and summary. Volume II contains complete performance prediction results (tabular and graphic output) and computer program listings.

  19. Underground Test Area Subproject Phase I Data Analysis Task. Volume VII - Tritium Transport Model Documentation Package

    SciTech Connect

    None

    1996-12-01

    Volume VII of the documentation for the Phase I Data Analysis Task performed in support of the current Regional Flow Model, Transport Model, and Risk Assessment for the Nevada Test Site Underground Test Area Subproject contains the tritium transport model documentation. Because of the size and complexity of the model area, a considerable quantity of data was collected and analyzed in support of the modeling efforts. The data analysis task was consequently broken into eight subtasks, and descriptions of each subtask's activities are contained in one of the eight volumes that comprise the Phase I Data Analysis Documentation.

  20. Underground Test Area Subproject Phase I Data Analysis Task. Volume VI - Groundwater Flow Model Documentation Package

    SciTech Connect

    None

    1996-11-01

    Volume VI of the documentation for the Phase I Data Analysis Task performed in support of the current Regional Flow Model, Transport Model, and Risk Assessment for the Nevada Test Site Underground Test Area Subproject contains the groundwater flow model data. Because of the size and complexity of the model area, a considerable quantity of data was collected and analyzed in support of the modeling efforts. The data analysis task was consequently broken into eight subtasks, and descriptions of each subtask's activities are contained in one of the eight volumes that comprise the Phase I Data Analysis Documentation.

  1. Underground Test Area Subproject Phase I Data Analysis Task. Volume II - Potentiometric Data Document Package

    SciTech Connect

    None

    1996-12-01

    Volume II of the documentation for the Phase I Data Analysis Task performed in support of the current Regional Flow Model, Transport Model, and Risk Assessment for the Nevada Test Site Underground Test Area Subproject contains the potentiometric data. Because of the size and complexity of the model area, a considerable quantity of data was collected and analyzed in support of the modeling efforts. The data analysis task was consequently broken into eight subtasks, and descriptions of each subtask's activities are contained in one of the eight volumes that comprise the Phase I Data Analysis Documentation.

  2. Cost Analysis of Different Volume Replacement Strategies in Anesthesia

    Microsoft Academic Search

    J. Boldt; S. Suttner; B. Kumle; I. Hüttner

    2000-01-01

    Summary Objective: Varying regimens of volume replacement are available. In today’s climate of cost consciousness and cost contain-ment it appears to be of interest to assess effective costs associated with the different fluid therapies. Design:Prospective, randomized study. Setting:Single-institutional, clinical investigation in an urban, university-affiliated hospital. Patients and Methods: 150 patients undergoing major abdominal surgery were divided into three groups. Perioperatively

  3. Economic Analysis of Lung Volume Reduction Surgery as Part of the National Emphysema Treatment Trial

    Microsoft Academic Search

    Scott D. Ramsey; Sean D. Sullivan; Robert M. Kaplan; Douglas E. Wood; Yen-Pin Chiang; Judith L. Wagner

    2010-01-01

    Background. In today's cost-conscious health care en- vironment, obtaining timely and accurate economic in- formation regarding new medical technologies has be- come extremely important. The National Emphysema Treatment Trial, a multicenter, randomized controlled trial of lung volume reduction surgery (LVRS) plus medical therapy, versus medical therapy for patients with severe emphysema, includes a parallel cost-effec- tiveness analysis. Methods. The analysis

  4. Comparative analysis of anterior segment parameters in normal and keratoconus eyes generated by scheimpflug tomography.

    PubMed

    Orucoglu, Faik; Toker, Ebru

    2015-01-01

    Purpose. To assess and compare the anterior and posterior corneal surface parameters, keratoconus indices, thickness profile data, and data from enhanced elevation maps of keratoconic and normal corneas with the Pentacam Scheimpflug corneal tomography and to determine the sensitivity and specificity of these parameters in discriminating keratoconus from normal eyes. Methods. The study included 656 keratoconus eyes and 515 healthy eyes with a mean age of 30.95 ± 9.25 and 32.90 ± 14.78 years, respectively. Forty parameters obtained from the Pentacam tomography were assessed by the receiver operating characteristic curve analysis for their efficiency. Results. Receiver operating characteristic curve analyses showed excellent predictive accuracy (area under the curve, ranging from 0.914 to 0.972) for 21 of the 40 parameters evaluated. Among all parameters indices of vertical asymmetry, keratoconus index, front elevation at thinnest location, back elevation at thinnest location, Ambrósio Relational Thickness (ARTmax), deviation of average pachymetric progression, deviation of ARTmax, and total deviation showed excellent (>90%) sensitivity and specificity in addition to excellent area under the receiver operating characteristic curve (AUROC). Conclusions. Parameters derived from the topometric and Belin-Ambrósio enhanced ectasia display maps very effectively discriminate keratoconus from normal corneas with excellent sensitivity and specificity. PMID:25878897

  5. Analysis of photoreceptor outer segment morphogenesis in zebrafish ift57, ift88 and ift172 intraflagellar transport mutants

    E-print Network

    Sukumaran, Sujita

    2009-05-15

    transmission electron microscopy to study the ultrastructure of photoreceptors at 60, 72 and 96 hours post fertilization (hpf). At 60 hpf, developing outer segments were seen in IFT57 mutant and wild type embryos, however, disorganized membranous structures...

  6. Measurement of fluid viscosity at microliter volumes using quartz impedance analysis

    Microsoft Academic Search

    Atul Saluja; Devendra S. Kalonia

    2004-01-01

    The purpose of this work was to measure viscosity of fluids at low microliter volumes by means of quartz crystal impedance\\u000a analysis. To achieve this, a novel setup was designed that allowed for measurement of viscosity at volumes of 8 to 10 ?L.\\u000a The technique was based on the principle of electromechanical coupling of piezoelectric quartz crystals. The arrangement was

  7. A comparison of volume-based and surface-based multi-voxel pattern analysis

    Microsoft Academic Search

    Nikolaas N. Oosterhof; Tobias Wiestler; Paul E. Downing; Jörn Diedrichsen

    2011-01-01

    For functional magnetic resonance imaging (fMRI), multi-voxel pattern analysis (MVPA) has been shown to be a sensitive method to detect areas that encode certain stimulus dimensions. By moving a searchlight through the volume of the brain, one can continuously map the information content about the experimental conditions of interest to the brain.Traditionally, the searchlight is defined as a volume sphere

  8. [Analysis of tumor volume in latent prostatic carcinoma].

    PubMed

    Wada, T; Ohoishi, Y; Tashiro, K; Kawashima, Y; Asano, K; Machida, T; Furusato, M; Ito, T; Kato, H; Aizawa, S

    1992-03-01

    An assessment has been made of the histopathological characteristics of latent prostatic carcinoma and the tumor volume in 500 male Japanese patients who underwent dissection at The Jikei University since 1983. A microscopic observation was made of the prostatic glands extirpated totally at the necropsy, fixed with formalin and prepared as a step-section in a thickness of 3 mm. In the cases of latent carcinoma, after photographing the lesion in the same magnification and measuring the area of the carcinoma lesion with a digitizer, the volume was calculated by multiplying the thickness of 3 mm, and carcinoma volume was determined by integrating the value of each slice and adjusted by a conversion formula. The incidence of latent carcinoma was 104 cases out of 500 (22%). The incidence increased as the age layer becomes higher, and latent carcinoma was observed in 44% of the patients aged 80 and above. Complication of latent carcinoma with prostatic hyperplasia was presumed to be an independent phenomenon in so far as it is seen from the statistical aspect. The patients were classified histopathologically into well-differentiated type (64%), mixed type (27%) and poorly-differentiated type (9%), showing high incidence in the low-aged layer of well-differentiated lesions and in the high-aged layer of mixed type lesions and in the high-aged layer of mixed type lesions. The average tumor volume of latent carcinoma was so small as 231 mm3, but many of the lesions in the cases of well-differentiated type were small, being on average 103.9 mm3, but many of the lesions in the cases of poorly-differentiated type were large, being on average 642.2 mm3. Statistically, with a tumor size of 200 mm3 as the boundary, a difference was observed in the distribution of histological constitution between the group with smaller lesions and the group with larger lesions. As an application of this result to the clinical carcinoma of stage A, the value of volume of 200 mm3 was considered to be important as a diagnostic criterion in deciding the necessity of treatment. PMID:1373454

  9. Comparison of human and automatic segmentations of kidneys from CT images

    SciTech Connect

    Rao, Manjori [Department of Radiation Oncology, University of North Carolina, Chapel Hill, NC (United States); Stough, Joshua [Department of Computer Science, University of North Carolina, Chapel Hill, NC (United States); Chi, Y.-Y. [Department of Biostatistics, University of North Carolina, Chapel Hill, NC (United States); Muller, Keith [Department of Biostatistics, University of North Carolina, Chapel Hill, NC (United States); Tracton, Gregg [Department of Radiation Oncology, University of North Carolina, Chapel Hill, NC (United States); Pizer, Stephen M. [Department of Radiation Oncology, University of North Carolina, Chapel Hill, NC (United States); Department of Computer Science, University of North Carolina, Chapel Hill, NC (United States); Chaney, Edward L. [Department of Radiation Oncology, University of North Carolina, Chapel Hill, NC (United States)]. E-mail: chaney@med.unc.edu

    2005-03-01

    Purpose: A controlled observer study was conducted to compare a method for automatic image segmentation with conventional user-guided segmentation of right and left kidneys from planning computerized tomographic (CT) images. Methods and materials: Deformable shape models called m-reps were used to automatically segment right and left kidneys from 12 target CT images, and the results were compared with careful manual segmentations performed by two human experts. M-rep models were trained based on manual segmentations from a collection of images that did not include the targets. Segmentation using m-reps began with interactive initialization to position the kidney model over the target kidney in the image data. Fully automatic segmentation proceeded through two stages at successively smaller spatial scales. At the first stage, a global similarity transformation of the kidney model was computed to position the model closer to the target kidney. The similarity transformation was followed by large-scale deformations based on principal geodesic analysis (PGA). During the second stage, the medial atoms comprising the m-rep model were deformed one by one. This procedure was iterated until no changes were observed. The transformations and deformations at both stages were driven by optimizing an objective function with two terms. One term penalized the currently deformed m-rep by an amount proportional to its deviation from the mean m-rep derived from PGA of the training segmentations. The second term computed a model-to-image match term based on the goodness of match of the trained intensity template for the currently deformed m-rep with the corresponding intensity data in the target image. Human and m-rep segmentations were compared using quantitative metrics provided in a toolset called Valmet. Metrics reported in this article include (1) percent volume overlap; (2) mean surface distance between two segmentations; and (3) maximum surface separation (Hausdorff distance). Results: Averaged over all kidneys the mean surface separation was 0.12 cm, the mean Hausdorff distance was 0.99 cm, and the mean volume overlap for human segmentations was 88.8%. Between human and m-rep segmentations the mean surface separation was 0.18-0.19 cm, the mean Hausdorff distance was 1.14-1.25 cm, and the mean volume overlap was 82-83%. Conclusions: Overall in this study, the best m-rep kidney segmentations were at least as good as careful manual slice-by-slice segmentations performed by two experienced humans, and the worst performance was no worse than typical segmentations from our clinical setting. The mean surface separations for human-m-rep segmentations were slightly larger than for human-human segmentations but still in the subvoxel range, and volume overlap and maximum surface separation were slightly better for human-human comparisons. These results were expected because of experimental factors that favored comparison of the human-human segmentations. In particular, m-rep agreement with humans appears to have been limited largely by fundamental differences between manual slice-by-slice and true three-dimensional segmentation, imaging artifacts, image voxel dimensions, and the use of an m-rep model that produced a smooth surface across the renal pelvis.

  10. Segmentation Using a Region Growing Thresholding Matei MANCAS1

    E-print Network

    Dupont, Stéphane

    it for spinal cord segmentation but it also shows results for parotid glands or even tumors. Moreover, it seems preliminary results which are encouraging. Keywords: Region Growing, Image Segmentation, Parotid Glands segmentation such as parotid glands ganglionic areas or spinal cord. Knowledge on precise position or volume

  11. Self-Paced Physics, Segment 41A-41E.

    ERIC Educational Resources Information Center

    New York Inst. of Tech., Old Westbury.

    The second review segment of the Self-Paced Physics Course is presented in this volume and arranged to match study segments 19 through 40. The segment is divided into five subsegments, each of which is composed of a set of problems and solutions. A study guide is provided for each subsegment. The problem set is designed in a back-referencing…

  12. Self-Paced Physics, Segments 15-17.

    ERIC Educational Resources Information Center

    New York Inst. of Tech., Old Westbury.

    Three review segments of the Self-Paced Physics Course materials are provided in this volume which is arranged to match study segments 1 through 14. Each of the three segments is composed of a set of problems and solutions, and accompanied by its own individual study guide. The problem set is designed as a back-referencing system, and the…

  13. Stochastic watershed segmentation Jess Angulo and Dominique Jeulin

    E-print Network

    Angulo,Jesús

    Stochastic watershed segmentation Jesús Angulo and Dominique Jeulin Centre de Morphologie.angulo,dominique.jeulin@ensmp.fr Abstract This paper introduces a watershed-based stochastic segmentation methodology. The approach is based is then segmented by volumic watershed for den- ing the R most signicant regions. It over-performs the standard

  14. A Finite-Volume "Shaving" Method for Interfacing NASA/DAO''s Physical Space Statistical Analysis System to the Finite-Volume GCM with a Lagrangian Control-Volume Vertical Coordinate

    NASA Technical Reports Server (NTRS)

    Lin, Shian-Jiann; DaSilva, Arlindo; Atlas, Robert (Technical Monitor)

    2001-01-01

    Toward the development of a finite-volume Data Assimilation System (fvDAS), a consistent finite-volume methodology is developed for interfacing the NASA/DAO's Physical Space Statistical Analysis System (PSAS) to the joint NASA/NCAR finite volume CCM3 (fvCCM3). To take advantage of the Lagrangian control-volume vertical coordinate of the fvCCM3, a novel "shaving" method is applied to the lowest few model layers to reflect the surface pressure changes as implied by the final analysis. Analysis increments (from PSAS) to the upper air variables are then consistently put onto the Lagrangian layers as adjustments to the volume-mean quantities during the analysis cycle. This approach is demonstrated to be superior to the conventional method of using independently computed "tendency terms" for surface pressure and upper air prognostic variables.

  15. Virtual Mastoidectomy Performance Evaluation through Multi-Volume Analysis

    PubMed Central

    Kerwin, Thomas; Stredney, Don; Wiet, Gregory; Shen, Han-Wei

    2012-01-01

    Purpose Development of a visualization system that provides surgical instructors with a method to compare the results of many virtual surgeries (n > 100). Methods A masked distance field models the overlap between expert and resident results. Multiple volume displays are used side-by-side with a 2D point display. Results Performance characteristics were examined by comparing the results of specific residents with those of experts and the entire class. Conclusions The software provides a promising approach for comparing performance between large groups of residents learning mastoidectomy techniques. PMID:22528058

  16. Segmental order in uniaxially strained bimodal polymer networks: a deuterium-NMR study

    NASA Astrophysics Data System (ADS)

    Chapellier, B.; Deloche, B.; Oeser, R.

    1993-11-01

    The segmental orientational order generated in bimodal poly(dimethylsiloxane) networks under uniaxial stress is probed using deuterium nuclear magnetic resonance (2H-NMR). The induced segmental order is measured either on “short” chains (M_n = 3000 g/mol) or on “long” chains (M_n = 25000 g/mol). The segmental orientation is very similar for both kinds of chains and decreases linearly as the volume fraction ?_L of “long” chain increases. A mean field analysis including orientational correlations between segments is developed and accounts for these observations. Additionally, this study has been carried out on two sets of samples with different crosslinkers. It shows clearly that the induced orientational order depends on the nature of the crosslinking junctions.

  17. Review of Department of Defense Education Activity (DoDEA) Schools. Volume II: Quantitative Analysis of Educational Quality. IDA Paper.

    ERIC Educational Resources Information Center

    Anderson, Lowell Bruce; Bracken, Jerome; Bracken, Marilyn C.

    This volume compiles, and presents in integrated form, the Institute for Defense Analyses' (IDA) quantitative analysis of educational quality provided by the Department of Defense's dependent schools. It covers the quantitative aspects of volume 1 in greater detail and presents some analyses deemed too technical for that volume. The first task in…

  18. Reproducibility of transvaginal three-dimensional endometrial volume measurements with virtual organ computer-aided analysis (VOCAL) during ovarian stimulation

    Microsoft Academic Search

    A. Bordes; M. Benchaib; R. C. Rudigoz; B. Salle

    2002-01-01

    Objective To calculate inter- and intraobserver reliabilities for three-dimensional endometrial volume measurements during in vitro fertilization using virtual organ computer- aided analysis (VOCAL \\

  19. Computerized segmentation and measurement of malignant pleural mesothelioma

    PubMed Central

    Sensakovic, William F.; Armato, Samuel G.; Straus, Christopher; Roberts, Rachael Y.; Caligiuri, Philip; Starkey, Adam; Kindler, Hedy L.

    2011-01-01

    Purpose: The current linear method to track tumor progression and evaluate treatment efficacy is insufficient for malignant pleural mesothelioma (MPM). A volumetric method for tumor measurement could improve the evaluation of novel treatments, but a fully manual implementation of volume measurement is too tedious and time-consuming. This manuscript presents a computerized method for the three-dimensional segmentation and volumetric analysis of MPM. Methods: The computerized MPM segmentation method segments the lung parenchyma and hemithoracic cavities to define the pleural space. Nonlinear diffusion and a k-means classifier are then implemented to identify MPM in the pleural space. A database of 31 computed tomography scans from 31 patients with pathologically confirmed MPM was retrospectively collected. Three observers independently outlined five randomly selected sections in each scan. The Jaccard similarity coefficient (J) between each of the observers and between the observer-defined and computer-defined segmentations was calculated. The computer-defined and the observer-defined segmentation areas (averaged over all observers) were both calculated for each axial section and compared using Bland–Altman plots. Results: The median J value among observers averaged over all sections was 0.517. The median J between the computer-defined and manual segmentations was 0.484. The difference between these values was not statistically significant. The area delineated by the computerized method demonstrated variability and bias comparable to the tumor area calculated from manual delineations. Conclusions: A computerized method for segmentation and measurement of MPM was developed. This method requires minimal initialization by the user and demonstrated good agreement with manually drawn outlines and area measurements. This method will allow volumetric tracking of tumor progression and may improve the evaluation of novel MPM treatments. PMID:21361192

  20. Segmented testing

    NASA Technical Reports Server (NTRS)

    Robinson, J. P.

    1984-01-01

    The fraction of faults detected for a digital network is frequently high for the first few input combinations applied out of a set of test vectors. When the particular ordering of test patterns does not appreciably change the shape of the coverage curve, there appears to be an advantage to splitting the test into segments which are applied at different times. It is shown that the expected time to error detection and the probability of an undetected double error can be reduced. The amount of reduction is dependent on the shape of the fault coverage curve. It is conjectured that such a reduction can be obtained for VLSI networks.

  1. Oil-spill risk analysis: Cook inlet outer continental shelf lease sale 149. Volume 1. The analysis. Final report

    SciTech Connect

    Johnson, W.R.; Marshall, C.F.; Anderson, C.M.; Lear, E.M.

    1994-08-01

    This report summarizes results of an oil-spill risk analysis (OSRA) conducted for the proposed lower Cook Inlet Outer Continental Shelf (OCS) Lease Sale 149. The objective of this analysis was to estimate relative oil-spill risks associated with oil and gas production from the leasing alternatives proposed for the lease sale. The Minerals Management Service (MMS) will consider the analysis in the environmental impact statement (EIS) prepared for the lease sale. The analysis for proposed OCS Lease Sale 149 was conducted in three parts corresponding to different aspects of the overall problem. The first part dealt with the probability of oil-spill occurrence. The second dealt with trajectories of oil spills from potential spill sites to various environmental resources or land segments. The third part combined the results of the first two parts to give estimates of the overall oil-spill risk if there is oil production as a result of the lease sale. To aid the analysis, conditional risk contour maps of seasonal conditional probabilities of spill contact were generated for each environmental resource or land segment in the study area (see vol. 2).

  2. Analysis of Cell Concentration, Volume Concentration, and Colony Size of Microcystis Via Laser Particle Analyzer

    NASA Astrophysics Data System (ADS)

    Li, Ming; Zhu, Wei; Gao, Li

    2014-05-01

    The analysis of the cell concentration, volume concentration, and colony size of Microcystis is widely used to provide early warnings of the occurrence of blooms and to facilitate the development of predictive tools to mitigate their impact. This study developed a new approach for the analysis of the cell concentration, volume concentration, and colony size of Microcystis by applying a laser particle analyzer. Four types of Microcystis samples (55 samples in total) were analyzed by a laser particle analyzer and a microscope. By the application of the laser particle analyzer (1) when n = 1.40 and k = 0.1 ( n is the intrinsic refractive index, whereas k is absorption of light by the particle), the results of the laser particle analyzer showed good agreement with the microscopic results for the obscuration indicator, volume concentration, and size distribution of Microcystis; (2) the Microcystis cell concentration can be calculated based on its linear relationship with obscuration; and (3) the volume concentration and size distribution of Microcystis particles (including single cells and colonies) can be obtained. The analytical processes involved in this new approach are simpler and faster compared to that by microscopic counting method. From the results, it was identified that the relationship between cell concentration and volume concentration depended on the colony size of Microcystis because the intercellular space was high when the colony size was high. Calculation of cell concentration and volume concentration may occur when the colony size information is sufficient.

  3. Random harmonic analysis program, L221 (TEV156). Volume 2: Supplemental system design and maintenenace document

    NASA Technical Reports Server (NTRS)

    Graham, M. L.; Clemmons, R. E.; Miller, R. D.

    1979-01-01

    Volume 2 of a two volume document is presented. A computer program, L222 (TEV 156), available for execution on the CDC 6600 computer is described. The program is capable of calculating steady-state solutions for linear second-order differential equations due to sinusoidal forcing functions. From this, steady-state solutions, generalized coordinates, and load frequency responses may be determined. Statistical characteristics of loads for the forcing function spectral shape may also be calculated using random harmonic analysis techniques. The particular field of application of the program is the analysis of airplane response and loads due to continuous random air turbulence.

  4. Information System: Analysis for the Peel Board of Education. Volume I: Description. Volume II: Technical Appendices.

    ERIC Educational Resources Information Center

    Padro, Susan

    Interviews with central office superintendents in the academic and business divisions, identification of user needs, and analysis of major management levels provided the data for designing an integrated information system for the Peel Board of Education in Ontario. A synthesis of the data into an overall framework representing the information…

  5. Demand modelling of passenger air travel: An analysis and extension, volume 2

    NASA Technical Reports Server (NTRS)

    Jacobson, I. D.

    1978-01-01

    Previous intercity travel demand models in terms of their ability to predict air travel in a useful way and the need for disaggregation in the approach to demand modelling are evaluated. The viability of incorporating non-conventional factors (i.e. non-econometric, such as time and cost) in travel demand forecasting models are determined. The investigation of existing models is carried out in order to provide insight into their strong points and shortcomings. The model is characterized as a market segmentation model. This is a consequence of the strengths of disaggregation and its natural evolution to a usable aggregate formulation. The need for this approach both pedagogically and mathematically is discussed. In addition this volume contains two appendices which should prove useful to the non-specialist in the area.

  6. A Bland-Altman Analysis of the Bias Between Computed Tomography and Ultrasound Prostate Volume Measurements

    SciTech Connect

    Gloi, Aime [Department of Radiation Oncology, St. Vincent Hospital, Green Bay, WI (United States)], E-mail: agloi@stvgb.org; McCourt, Stephen; Zuge, Corrie; Goettler, AnnDrea; Schlise, Sally; Cooley, Greg [Department of Radiation Oncology, St. Vincent Hospital, Green Bay, WI (United States)

    2008-10-01

    This study assesses the agreement between computed tomography (CT) measurements of prostate volume and those obtained by ultrasound (US), a well-established non-invasive technique. Twenty-six patients aged between 58 and 74 years were evaluated for prostate seed implant therapy using both CT and US measurements. The level of agreement between these 2 methods, which were strongly correlated (R{sup 2} = 0.828; p < 0.0001), was determined through Bland-Altman analysis. The mean prostate volume ({+-} one standard deviation) of the sample was 31.8 {+-} 10.5 cc for the CT method and 27.0 {+-} 8.2 cc for the US method. The prostate volumes obtained by CT were, on average, 17% larger than the corresponding volumes determined by US. The average bias between the 2 imaging methods is 4.80 cc or 15%, which is significantly larger than the clinically acceptable margin of 10%.

  7. Isomap transform for segmenting human body shapes

    Microsoft Academic Search

    P. Cerveri; K. J. Sarro; M. Marchente; R. M. L. Barros

    2011-01-01

    Segmentation of the 3D human body is a very challenging problem in applications exploiting volume capture data. Direct clustering in the Euclidean space is usually complex or even unsolvable. This paper presents an original method based on the Isomap (isometric feature mapping) transform of the volume data-set. The 3D articulated posture is mapped by Isomap in the pose of Da

  8. Study on skin color image segmentation used by Fuzzy-c-means arithmetic

    Microsoft Academic Search

    Keke Shang; Peng Zhou; Guohui Li

    2010-01-01

    Skin color image segmentation is an important part in skin image analysis. Segmentation feature parameter and segmentation arithmetic significantly influence the segmentation result. In this article, we compared RGB, HSV, and Lab color spaces and found that HSV color space as segmentation feature parameter has the advantage. Furthermore, we used an improved Fuzzy-c-means arithmetic (IFCM) in skin color image segmentation

  9. Electronic Transactions on Numerical Analysis. Volume 32, pp. 173189, 2008.

    E-print Network

    Dobrowolski, Manfred

    State University. ISSN 1068­9613. ETNA Kent State University etna@mcs.kent.edu NUMERICAL ANALYSIS­97074 Wuerzburg, Germany (dobro@mathematik.uni­wuerzburg.de). 173 #12; ETNA Kent State University etna

  10. Combined subsegmentectomy: postoperative pulmonary function compared to multiple segmental resection

    Microsoft Academic Search

    Kentaro Yoshimoto; Hiroaki Nomori; Takeshi Mori; Yasuomi Ohba; Kenji Shiraishi; Koei Ikeda

    2011-01-01

    Background  For small peripheral c-T1N0M0 non-small cell lung cancers involving multiple segments, we have conducted a resection of subsegments\\u000a belonging to different segments, i.e. combined subsegmentectomy (CSS), to avoid resection of multiple segments or lobectomy.\\u000a Tumor size, location of tumor, and forced expiratory volume in 1 second (FEV1) of each preserved lobe were compared among the CSS, resection of single segment,

  11. Effective SAR Image Segmentation in Analysis of Sea Ice Floe Distribution (FSD) Using Graph-cut Based Feature Extraction and Fusion

    NASA Astrophysics Data System (ADS)

    Sakhalkar, S.

    2014-12-01

    Soumitra Sakhalkar1, Jinchang Ren1 and Byong Jun Hwang21 Centre for excellence in Signal & Image Processing (CeSIP), Department of Electronic and Electrical Engineering, University of Strathclyde, Glasgow, G1 1XQ, UK.2 Scottish Association for Marine Science (SAMS), Oban, PA37 1QA, UK.Sea ices that grow in the open seas are characteristically different in forms and shapes from the largely smooth sea ice that grows in calm inlets. For example, strong force from winds and waves fractures the thick sea ice into pieces or floes, which then collide with each other. In studies of the Polar Regions with satellite SAR (Synthetic Aperture Radar) imagery, identification of ice floes and their distribution is particularly important for examining for both large and small scale applications.In this paper, a Graph-Cut (GC) based feature extraction and fusion technique has been proposed for effective segmentation of SAR images and following on FSD analysis. Though GC based approach has been used in the segmentation of natural images, the application of it on SAR image in this context is rare. Based on an energy minimization process, the GC technique has utilized a graph based representation in grouping pixels for segmentation. To deal with sparkle noise, effective pre-processing and image filter is also applied.To validate the efficacy of the proposed approach, real SAR images with a high resolution of 16k by 16k are used for both visual assessment and quantitative analysis. In comparison to several state-of-the-art algorithms such as watershed and K-means it is found kernel based GC approach yields the most accurate results as shown in Fig. 1. Fig. 1: One example image (t-l) and its ground truth (t-m) along with results of segmentation using graph cut (t-r) and (b-l), watershed (b-m) and K-means (b-r).

  12. An investigation of wing buffeting response at subsonic and transonic speeds. Phase 1: F-111A flight data analysis. Volume 3: Tabulated power spectra

    NASA Technical Reports Server (NTRS)

    Benepe, D. B.; Cunningham, A. M., Jr.; Dunmyer, W. D.

    1978-01-01

    Volume 3 of this three volume report is presented. This volume presents power spectral density in tabular form for the convenience of those who might wish to perform additional analysis. Some of the information contained in Volume 1 is again repeated (as in volume 2) in this volume to allow the reader to identify the specific conditions appropriate to each tabular listing and for further analysis.

  13. On 3-D inelastic analysis methods for hot section components. Volume 1: Special finite element models

    NASA Technical Reports Server (NTRS)

    Nakazawa, S.

    1987-01-01

    This Annual Status Report presents the results of work performed during the third year of the 3-D Inelastic Analysis Methods for Hot Section Components program (NASA Contract NAS3-23697). The objective of the program is to produce a series of new computer codes that permit more accurate and efficient three-dimensional analysis of selected hot section components, i.e., combustor liners, turbine blades, and turbine vanes. The computer codes embody a progression of mathematical models and are streamlined to take advantage of geometrical features, loading conditions, and forms of material response that distinguish each group of selected components. This report is presented in two volumes. Volume 1 describes effort performed under Task 4B, Special Finite Element Special Function Models, while Volume 2 concentrates on Task 4C, Advanced Special Functions Models.

  14. Viscous wing theory development. Volume 1: Analysis, method and results

    NASA Technical Reports Server (NTRS)

    Chow, R. R.; Melnik, R. E.; Marconi, F.; Steinhoff, J.

    1986-01-01

    Viscous transonic flows at large Reynolds numbers over 3-D wings were analyzed using a zonal viscid-inviscid interaction approach. A new numerical AFZ scheme was developed in conjunction with the finite volume formulation for the solution of the inviscid full-potential equation. A special far-field asymptotic boundary condition was developed and a second-order artificial viscosity included for an improved inviscid solution methodology. The integral method was used for the laminar/turbulent boundary layer and 3-D viscous wake calculation. The interaction calculation included the coupling conditions of the source flux due to the wing surface boundary layer, the flux jump due to the viscous wake, and the wake curvature effect. A method was also devised incorporating the 2-D trailing edge strong interaction solution for the normal pressure correction near the trailing edge region. A fully automated computer program was developed to perform the proposed method with one scalar version to be used on an IBM-3081 and two vectorized versions on Cray-1 and Cyber-205 computers.

  15. SLUDGE TREATMENT PROJECT ALTERNATIVES ANALYSIS SUMMARY REPORT [VOLUME 1

    SciTech Connect

    FREDERICKSON JR; ROURK RJ; HONEYMAN JO; JOHNSON ME; RAYMOND RE

    2009-01-19

    Highly radioactive sludge (containing up to 300,000 curies of actinides and fission products) resulting from the storage of degraded spent nuclear fuel is currently stored in temporary containers located in the 105-K West storage basin near the Columbia River. The background, history, and known characteristics of this sludge are discussed in Section 2 of this report. There are many compelling reasons to remove this sludge from the K-Basin. These reasons are discussed in detail in Section1, and they include the following: (1) Reduce the risk to the public (from a potential release of highly radioactive material as fine respirable particles by airborne or waterborn pathways); (2) Reduce the risk overall to the Hanford worker; and (3) Reduce the risk to the environment (the K-Basin is situated above a hazardous chemical contaminant plume and hinders remediation of the plume until the sludge is removed). The DOE-RL has stated that a key DOE objective is to remove the sludge from the K-West Basin and River Corridor as soon as possible, which will reduce risks to the environment, allow for remediation of contaminated areas underlying the basins, and support closure of the 100-KR-4 operable unit. The environmental and nuclear safety risks associated with this sludge have resulted in multiple legal and regulatory remedial action decisions, plans,and commitments that are summarized in Table ES-1 and discussed in more detail in Volume 2, Section 9.

  16. Ceramic component development analysis -- Volume 1. Final report

    SciTech Connect

    Boss, D.E.

    1998-06-09

    The development of advanced filtration media for advanced fossil-fueled power generating systems is a critical step in meeting the performance and emissions requirements for these systems. While porous metal and ceramic candle-filters have been available for some time, the next generation of filters will include ceramic-matrix composites (CMCs) (Techniweave/Westinghouse, Babcock and Wilcox (B and W), DuPont Lanxide Composites), intermetallic alloys (Pall Corporation), and alternate filter geometries (CeraMem Separations). The goal of this effort was to perform a cursory review of the manufacturing processes used by 5 companies developing advanced filters from the perspective of process repeatability and the ability for their processes to be scale-up to produce volumes. Given the brief nature of the on-site reviews, only an overview of the processes and systems could be obtained. Each of the 5 companies had developed some level of manufacturing and quality assurance documentation, with most of the companies leveraging the procedures from other products they manufacture. It was found that all of the filter manufacturers had a solid understanding of the product development path. Given that these filters are largely developmental, significant additional work is necessary to understand the process-performance relationships and projecting manufacturing costs.

  17. Wireless Capsule Endoscopy Video Segmentation Using an Unsupervised Learning Approach Based on Probabilistic Latent Semantic Analysis With Scale Invariant Features

    Microsoft Academic Search

    Yao Shen; Bill P. Buckles

    2012-01-01

    Since wireless capsule endoscopy (WCE) is a novel technology for recording the videos of the digestive tract of a patient, the problem of segmenting the WCE video of the digestive tract into subvideos corresponding to the entrance, stomach, small intestine, and large intestine regions is not well addressed in the literature. A selected few papers addressing this problem follow supervised

  18. Mutational Analysis of the Connector Segment in the HAMP Domain of Tsr, the Escherichia coli Serine Chemoreceptor

    Microsoft Academic Search

    Peter Ames; Qin Zhou; John S. Parkinson

    2008-01-01

    HAMP domains are 50-residue motifs, found in many bacterial signaling proteins, that consist of two amphiphilic helices joined by a nonhelical connector segment. The HAMP domain of Tsr, the serine chemo- receptor of Escherichia coli, receives transmembrane input signals from the periplasmic serine binding domain and in turn modulates output signals from the Tsr kinase control domain to elicit chemotactic

  19. IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING, VOL. 49, NO. 4, APRIL 2002 363 Feature Analysis and Centromere Segmentation of

    E-print Network

    British Columbia, University of

    and Centromere Segmentation of Human Chromosome Images Using an Iterative Fuzzy Algorithm Parvin Mousavi, Rabab--Classification of homologous chromosomes is essen- tial to advanced studies of cancer genetics. Centromere intensities of centromeres is a major step toward the realization of homolog classification. This paper describes

  20. Analysis of length and surface area of each segment of the large intestine according to age, sex and physique

    Microsoft Academic Search

    S Sadahiro; T Ohmura; Y Yamada; T Saito; Y Taki

    1992-01-01

    Summary Length, diameter and surface area of each of 6 segments of the large intestine were determined and calculated in 920 Japanese patients who underwent barium enema. Of the length and surface area measurements obtained, those of the transverse colon were the largest, followed by those of the sigmoid colon. The diameter of the ascending colon was the largest, while

  1. RFLP analysis of the size of chromosomal segments retained around the Tm2 locus of tomato during backcross breeding

    Microsoft Academic Search

    N. D. Young; S. D. Tanksley

    1989-01-01

    Genes introduced into cultivated plants by backcross breeding programs are flanked by introgressed segments of DNA derived from the donor parent. This phenomenon is known as linkage drag and is frequently thought to affect traits other than the one originally targeted. The Tm-2 gene of Lycopersicon peruvianum, which confers resistance to tobacco mosaic virus, was introduced into several different tomato

  2. What drives investors'behaviour in dierent FX market segments? A VAR-based return decomposition analysis

    Microsoft Academic Search

    Olli Castren; Chiara Osbat; Matthias Sydow

    2006-01-01

    We apply the Campbell-Shiller return decomposition to exchange rate returns and fundamentals in a stationary panel vector autoregression framework. The return decomposition is then used to analyse how dif- ferent investor segments react to news as captured by the dierent return components. The results suggest that intrinsic value news are dominat- ing for equity investors and speculative money market investors

  3. Color image segmentation by pixel classification in an adapted hybrid color space. Application to soccer image analysis

    Microsoft Academic Search

    Nicolas Vandenbroucke; Ludovic Macaire; Jack-gérard Postaire

    2003-01-01

    In this paper, we propose an original approach in order to improve the results of color im- age segmentation by pixel classification. We define a new kind of color space by selecting a set of color components which can belong to any of the different classical color spaces. Such spaces, which have neither psycho-visual nor physical color significance, are named

  4. ACOUSTIC INDICATORS OF TOPIC SEGMENTATION Julia Hirschberg Christine Nakatani

    E-print Network

    Hirschberg, Julia

    ACOUSTIC INDICATORS OF TOPIC SEGMENTATION Julia Hirschberg Christine Nakatani AT&T Labs) DARPA/NIST database. 1. INTRODUCTION The segmentation of speech into meaningful units of analysis and discourse analysis, because there exist fun­ damental correspondences between the acoustic

  5. Finite element analysis of laminated plates and shells, volume 1

    NASA Technical Reports Server (NTRS)

    Seide, P.; Chang, P. N. H.

    1978-01-01

    The finite element method is used to investigate the static behavior of laminated composite flat plates and cylindrical shells. The analysis incorporates the effects of transverse shear deformation in each layer through the assumption that the normals to the undeformed layer midsurface remain straight but need not be normal to the mid-surface after deformation. A digital computer program was developed to perform the required computations. The program includes a very efficient equation solution code which permits the analysis of large size problems. The method is applied to the problem of stretching and bending of a perforated curved plate.

  6. Geotechnical Analysis Report for July 2004 - June 2005, Volume 2, Supporting Data

    SciTech Connect

    Washington TRU Solutions LLC

    2006-03-20

    This report is a compilation of geotechnical data presented as plots for each active instrument installed in the underground at the Waste Isolation Pilot Plant (WIPP) through June 30, 2005. A summary of the geotechnical analyses that were performed using the enclosed data is provided in Volume 1 of the Geotechnical Analysis Report (GAR).

  7. Waste Isolation Pilot Plant Geotechnical Analysis Report for July 2005 - June 2006, Volume 2, Supporting Data

    SciTech Connect

    Washington TRU Solutions LLC

    2007-03-25

    This report is a compilation of geotechnical data presented as plots for each active instrument installed in the underground at the Waste Isolation Pilot Plant (WIPP) through June 30, 2006. A summary of the geotechnical analyses that were performed using the enclosed data is provided in Volume 1 of the Geotechnical Analysis Report (GAR).

  8. Weibull statistical analysis of area and volume effects on the breakdown strength in liquid nitrogen

    Microsoft Academic Search

    H. Goshima; N. Hayakawa; M. Hikita; H. Okubo; K. Uchida

    1995-01-01

    In order to examine the area and the volume effects on breakdown strength in liquid nitrogen (LN2), we measured dc and ac breakdown voltages in LN2 with sphere to plane and coaxial cylindrical electrode configurations. We also carried out statistical analysis of the experimental results using the Weibull distribution and discussed with the statistical stressed electrode area (SSEA) and\\/or liquid

  9. Definition and sensitivity analysis of a finite volume SOFC model for a tubular cell geometry

    Microsoft Academic Search

    S. Campanari; P. Iora

    2004-01-01

    A finite volume model of a solid oxide fuel cell has been developed. The model applies a detailed electrochemical and thermal analysis to a tubular SOFC of given geometry, material properties and assigned input flows. Electrochemical modeling includes an evaluation of ohmic, activation and diffusion losses as well as a kinetic model of hydrocarbon reactions, based on most recent literature

  10. Electronic Transactions on Numerical Analysis. Volume 28, pp. 149-167, 2008.

    E-print Network

    O'Leary, Dianne P.

    State University. ISSN 1068-9613. ETNA Kent State University etna@mcs.kent.edu A WEIGHTED-GCV METHOD'LEARY No regularization method is effective without an appropriate choice of the regularization parameter. VariousElectronic Transactions on Numerical Analysis. Volume 28, pp. 149-167, 2008. Copyright © 2008, Kent

  11. The Journal of Fourier Analysis and Applications Volume 4, Issue 2, 1998

    E-print Network

    Lau, Ka Sing

    The Journal of Fourier Analysis and Applications Volume 4, Issue 2, 1998 Asymptotic Behavior(x) = I-IT=0 g (x/2n). In this article we investigate the asymptotic behavior of foT [G(x)lqdx and 1 n ~k principle. An algorithm to calculate the pressure is presented. The results are applied to study

  12. Radio Science, Volume ???, Number , Pages 131, Radio tomography of the ionosphere: Analysis

    E-print Network

    Garcia, Raphaël

    Radio Science, Volume ???, Number , Pages 1­31, Radio tomography of the ionosphere: Analysis AND CRESPON: 4D IONOSPHERE TOMOGRAPHY After analysing the forward and inverse problems of radio tomography, and constrained by NeQuick ionosphere model and its spatial gradients. Our inversion scheme is fundamentally

  13. Cost Analysis of Correctional Standards: Halfway Houses. Volumes I and II.

    ERIC Educational Resources Information Center

    Thalheimer, Donald J.

    The Standards and Goals Project has undertaken cost analysis of halfway houses in order to analyze and estimate the costs of implementing correctional standards, and to provide cost guidelines and cost estimation techniques for use by jurisdictions. The first volume: (1) provides a brief background on the Corrections Standards relating to halfway…

  14. Substrate volume and stress gradient concepts in mechanical adhesion: analysis of single straight sections

    Microsoft Academic Search

    Erol Sancaktar; Kiran Narayan

    1999-01-01

    The primary objective of this study was to optimize the geometry and volume of the substrate in lap, butt, and scarf adhesive joints under various loading and boundary conditions by finite element analysis. The finite element models are validated by evaluating for convergence and by calculating theoretical values using the strength of materials and applied elasticity. The results of this

  15. A STANDARD PROCEDURE FOR COST ANALYSIS OF POLLUTION CONTROL OPERATIONS. VOLUME I. USER GUIDE

    EPA Science Inventory

    Volume I is a user guide for a standard procedure for the engineering cost analysis of pollution abatement operations and processes. The procedure applies to projects in various economic sectors: private, regulated, and public. The models are consistent with cost evaluation pract...

  16. Precise measurement of liquid petroleum tank volume based on data cloud analysis

    Microsoft Academic Search

    Jintao Wang; Ziyong Liu; Long Zhang; Ligong Guo; Xuesong Bao; Lin Tong

    2010-01-01

    Metal tanks are generally used for the measurement of liquid petroleum products for fiscal or custody transfer application. One tank volume precise measurement method based on data cloud analysis was studied, which was acquired by laser scanning principle. Method of distance measurement by laser phase shift and angular measurement by optical grating were applied to acquire coordinates of points in

  17. Volume 15, number 5 June/July 2010 markets products analysis research forecasts

    E-print Network

    Volume 15, number 5 June/July 2010 highlights markets products analysis research forecasts CliCk here to visit our website (www.woodmarkets.com)! international Wood markets Group inc. is pleased to provide you with an overview of our monthly 12-page WOOD Markets newsletter. The excerpts displayed

  18. Volume 15, number 3 april 2010 markets products analysis research forecasts

    E-print Network

    Volume 15, number 3 april 2010 highlights markets products analysis research forecasts Cli and fractured. This is a widespread phenomenon that is showing up in many products, channels and markets around the world in almost all wood products. While WOOD MARKETS' supply and demand models have been

  19. Gait Volume : Spatio-Temporal Analysis of Walking Yu Ohara, Ryusuke Sagawa, Tomio Echigo, and Yasushi Yagi

    E-print Network

    Sagawa, Ryusuke

    Gait Volume : Spatio-Temporal Analysis of Walking Yu Ohara, Ryusuke Sagawa, Tomio Echigo pattern. This paper also evaluates the availability of three dimensional frequency analysis of the gait data, here called "gait volume", contain in- formation not only of spatial individualities

  20. SCARF: a segmental conditional random field toolkit for speech recognition

    Microsoft Academic Search

    Geoffrey Zweig; Patrick Nguyen

    2010-01-01

    This paper describes a new toolkit - SCARF - for doing speech recognition with segmental conditional random fields. It is de- signed to allow for the integration of numerous, possibly re- dundant segment level acoustic features, along with a complete language model, in a coherent speech recognition framework. SCARF performs a segmental analysis, where each segment cor- responds to a

  1. Segment-Wise Genome-Wide Association Analysis Identifies a Candidate Region Associated with Schizophrenia in Three Independent Samples

    PubMed Central

    Rietschel, Marcella; Mattheisen, Manuel; Breuer, René; Schulze, Thomas G.; Nöthen, Markus M.; Levinson, Douglas; Shi, Jianxin; Gejman, Pablo V.; Cichon, Sven; Ophoff, Roel A.

    2012-01-01

    Recent studies suggest that variation in complex disorders (e.g., schizophrenia) is explained by a large number of genetic variants with small effect size (Odds Ratio?1.05–1.1). The statistical power to detect these genetic variants in Genome Wide Association (GWA) studies with large numbers of cases and controls (?15,000) is still low. As it will be difficult to further increase sample size, we decided to explore an alternative method for analyzing GWA data in a study of schizophrenia, dramatically reducing the number of statistical tests. The underlying hypothesis was that at least some of the genetic variants related to a common outcome are collocated in segments of chromosomes at a wider scale than single genes. Our approach was therefore to study the association between relatively large segments of DNA and disease status. An association test was performed for each SNP and the number of nominally significant tests in a segment was counted. We then performed a permutation-based binomial test to determine whether this region contained significantly more nominally significant SNPs than expected under the null hypothesis of no association, taking linkage into account. Genome Wide Association data of three independent schizophrenia case/control cohorts with European ancestry (Dutch, German, and US) using segments of DNA with variable length (2 to 32 Mbp) was analyzed. Using this approach we identified a region at chromosome 5q23.3-q31.3 (128–160 Mbp) that was significantly enriched with nominally associated SNPs in three independent case-control samples. We conclude that considering relatively wide segments of chromosomes may reveal reliable relationships between the genome and schizophrenia, suggesting novel methodological possibilities as well as raising theoretical questions. PMID:22723893

  2. Segment inertial parameter evaluation in two anthropometric models by application of a dynamic linked segment model

    Microsoft Academic Search

    Idsart Kingma; Huub M. Toussaint; Michiel P. De Looze; Jaap H. Van Dieen

    1996-01-01

    The estimation of segment inertial parameters (SIPs) is an important source of error in inverse dynamic analysis. In most individual cases SIPs are derived from extrapolation of known SIPs of a certain population through regression equations (proportional models). Another well-known method is the use of mathematical approximation of the shape of human body segments combined with estimations of segment densities

  3. Economic analysis of lung volume reduction surgery as part of the national emphysema treatment trial

    Microsoft Academic Search

    Scott D Ramsey; Sean D Sullivan; Robert M Kaplan; Douglas E Wood; Yen-Pin Chiang; Judith L Wagner

    2001-01-01

    Background. In today’s cost-conscious health care environment, obtaining timely and accurate economic information regarding new medical technologies has become extremely important. The National Emphysema Treatment Trial, a multicenter, randomized controlled trial of lung volume reduction surgery (LVRS) plus medical therapy, versus medical therapy for patients with severe emphysema, includes a parallel cost-effectiveness analysis.Methods. The analysis is designed to determine the

  4. Lobar analysis of collapsibility indices to assess functional lung volumes in COPD patients

    PubMed Central

    Kitano, Mariko; Iwano, Shingo; Hashimoto, Naozumi; Matsuo, Keiji; Hasegawa, Yoshinori; Naganawa, Shinji

    2014-01-01

    Background We investigated correlations between lung volume collapsibility indices and pulmonary function test (PFT) results and assessed lobar differences in chronic obstructive pulmonary disease (COPD) patients, using paired inspiratory and expiratory three dimensional (3D) computed tomography (CT) images. Methods We retrospectively assessed 28 COPD patients who underwent paired inspiratory and expiratory CT and PFT exams on the same day. A computer-aided diagnostic system calculated total lobar volume and emphysematous lobar volume (ELV). Normal lobar volume (NLV) was determined by subtracting ELV from total lobar volume, both for inspiratory phase (NLVI) and for expiratory phase (NLVE). We also determined lobar collapsibility indices: NLV collapsibility ratio (NLVCR) (%) = (1 ? NLVE/NLVI) × 100%. Associations between lobar volumes and PFT results, and collapsibility indices and PFT results were determined by Pearson correlation analysis. Results NLVCR values were significantly correlated with PFT results. Forced expiratory volume in 1 second, measured as percent of predicted results (FEV1%P) was significantly correlated with NLVCR values for the lower lobes (P<0.01), whereas this correlation was not significant for the upper lobes (P=0.05). FEV1%P results were also moderately correlated with inspiratory, expiratory ELV (ELVI,E) for the lower lobes (P<0.05). In contrast, the ratio of the diffusion capacity for carbon monoxide to alveolar gas volume, measured as percent of predicted (DLCO/VA%P) results were strongly correlated with ELVI for the upper lobes (P<0.001), whereas this correlation with NLVCR values was weaker for upper lobes (P<0.01) and was not significant for the lower lobes (P=0.26). Conclusion FEV1%P results were correlated with NLV collapsibility indices for lower lobes, whereas DLCO/VA%P results were correlated with NLV collapsibility indices and ELV for upper lobes. Thus, evaluating lobar NLV collapsibility might be useful for estimating pulmonary function in COPD patients. PMID:25525352

  5. County: Bonneville Station # 176 District: 06 Route: I-15 Ascending Direction: North Segment Code and Milepost: 001330 114.645 0.15 Mi. N of New Sweden School Road UP (New Sweden) Volumes and Percent of Daily Traffic

    Microsoft Academic Search

    Sunday Monday

    2006-01-01

    Hour Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day 0:00 283 1.7% 183 1.0% 155 0.8% 165 0.8% 175 0.8% 203 0.9% 279 1.5% 170 0.9% 281 1.6%

  6. County: Boise Station # 184 District: 03 Route: SH55 Ascending Direction: North Segment Code and Milepost: 001990 078.748 379 Ft S of Garden Valley Rd (S. Banks) Volumes and Percent of Daily Traffic

    Microsoft Academic Search

    Sunday Monday

    2007-01-01

    Hour Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day 0:00 27 0.5% 16 0.4% 21 0.7% 14 0.5% 16 0.5% 17 0.3% 25 0.5% 17 0.5% 26 0.5%

  7. County: Ada Station # 010 District: 03 Route: SH55 Ascending Direction: North Segment Code and Milepost: 001990 047.830 3.3 Miles North of Jct SH44 (Dry Creek) Volumes and Percent of Daily Traffic

    Microsoft Academic Search

    Sunday Monday

    2005-01-01

    Hour Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day 0:00 58 0.6% 33 0.4% 32 0.5% 22 0.4% 23 0.3% 34 0.4% 58 0.7% 28 0.4% 58 0.7%

  8. County: Lincoln Station # 014 District: 04 Route: SH75 Ascending Direction: North Segment Code and Milepost: 002230 079.670 6.0 Miles North of North Rail St (Shoshone) Volumes and Percent of Daily Traffic

    Microsoft Academic Search

    Sunday Monday

    2005-01-01

    Hour Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day 0:00 37 0.9% 16 0.4% 12 0.3% 13 0.3% 21 0.5% 22 0.4% 35 0.8% 16 0.4% 36 0.8%

  9. County: Elmore Station # 071 District: 03 Route: I-84 Ascending Direction: East Segment Code and Milepost: 001010 114.500 0.5 Miles East of Jct I-84B (Hammett) Volumes and Percent of Daily Traffic

    Microsoft Academic Search

    Sunday Monday

    2006-01-01

    Hour Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day 0:00 169 1.2% 135 1.2% 184 1.5% 159 1.2% 159 1.1% 189 1.1% 205 1.4% 159 1.2% 187 1.3%

  10. County: Ada Station # 080 District: 03 Route: SMA 7643 Ascending Direction: North Segment Code and Milepost: 002140 004.144 0.5 Miles South of Warm Springs Ave, Boise (Eckert Road) Volumes and Percent of Daily Traffic

    Microsoft Academic Search

    Sunday Monday

    2009-01-01

    Hour Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day 0:00 29 1.0% 14 0.4% 9 0.2% 14 0.4% 34 0.9% 16 0.4% 25 0.7% 18 0.5% 27 0.9%

  11. Analysis of flexible aircraft longitudinal dynamics and handling qualities. Volume 2: Data

    NASA Technical Reports Server (NTRS)

    Waszak, M. R.; Schmidt, D. K.

    1985-01-01

    Two analysis methods are applied to a family of flexible aircraft in order to investigate how and when structural (especially dynamic aeroelastic) effects affect the dynamic characteristics of aircraft. The first type of analysis is an open loop modal analysis technique. This method considers the effect of modal residue magnitudes on determining vehicle handling qualities. The second method is a pilot in the loop analysis procedure that considers several closed loop system characteristics. Both analyses indicated that dynamic aeroelastic effects caused a degradation in vehicle tracking performance, based on the evaluation of some simulation results. Volume 2 consists of the presentation of the state variable models of the flexible aircraft configurations used in the analysis applications mode shape plots for the structural modes, numerical results from the modal analysis frequency response plots from the pilot in the loop analysis and a listing of the modal analysis computer program.

  12. Quantification of regional fat volume in rat MRI

    NASA Astrophysics Data System (ADS)

    Sacha, Jaroslaw P.; Cockman, Michael D.; Dufresne, Thomas E.; Trokhan, Darren

    2003-05-01

    Multiple initiatives in the pharmaceutical and beauty care industries are directed at identifying therapies for weight management. Body composition measurements are critical for such initiatives. Imaging technologies that can be used to measure body composition noninvasively include DXA (dual energy x-ray absorptiometry) and MRI (magnetic resonance imaging). Unlike other approaches, MRI provides the ability to perform localized measurements of fat distribution. Several factors complicate the automatic delineation of fat regions and quantification of fat volumes. These include motion artifacts, field non-uniformity, brightness and contrast variations, chemical shift misregistration, and ambiguity in delineating anatomical structures. We have developed an approach to deal practically with those challenges. The approach is implemented in a package, the Fat Volume Tool, for automatic detection of fat tissue in MR images of the rat abdomen, including automatic discrimination between abdominal and subcutaneous regions. We suppress motion artifacts using masking based on detection of implicit landmarks in the images. Adaptive object extraction is used to compensate for intensity variations. This approach enables us to perform fat tissue detection and quantification in a fully automated manner. The package can also operate in manual mode, which can be used for verification of the automatic analysis or for performing supervised segmentation. In supervised segmentation, the operator has the ability to interact with the automatic segmentation procedures to touch-up or completely overwrite intermediate segmentation steps. The operator's interventions steer the automatic segmentation steps that follow. This improves the efficiency and quality of the final segmentation. Semi-automatic segmentation tools (interactive region growing, live-wire, etc.) improve both the accuracy and throughput of the operator when working in manual mode. The quality of automatic segmentation has been evaluated by comparing the results of fully automated analysis to manual analysis of the same images. The comparison shows a high degree of correlation that validates the quality of the automatic segmentation approach.

  13. Atmospheric analysis and prediction model development, volume 1

    NASA Technical Reports Server (NTRS)

    Kesel, P. G.; Wellck, R. E.; Langland, R. A.; Lewit, H. L.

    1976-01-01

    A set of hemispheric atmospheric analysis and prediction models was designed and tested. All programs were executed on either a 63 x 63 or 187 x 187 polar stereographic grid of the Northern Hemisphere. Parameters for objective analysis included sea surface temperature, sea level pressure, and twelve levels (from 1,000 to 100 millibars) of temperatures, heights, and winds. Stratospheric extensions (up to 10 millibars) were also provided. Four versions of a complex atmospheric prediction model, based on primitive equations, were programmed and tested. These models were executed on either the 63 x 63 or 187 x 187 grid, using either five or ten computational layers. The coarse-mesh (63 x 63) models were tested using real data for the period 21-23 April 1976. The fine-mesh (187 x 187) models were debugged, but insufficient computer resources precluded production tests. Preliminary test results for the 63 x 63 models are provided. Problem areas and proposed solutions are discussed.

  14. Spaceborne power systems preference analyses. Volume 2: Decision analysis

    NASA Technical Reports Server (NTRS)

    Smith, J. H.; Feinberg, A.; Miles, R. F., Jr.

    1985-01-01

    Sixteen alternative spaceborne nuclear power system concepts were ranked using multiattribute decision analysis. The purpose of the ranking was to identify promising concepts for further technology development and the issues associated with such development. Four groups were interviewed to obtain preference. The four groups were: safety, systems definition and design, technology assessment, and mission analysis. The highest ranked systems were the heat-pipe thermoelectric systems, heat-pipe Stirling, in-core thermionic, and liquid-metal thermoelectric systems. The next group contained the liquid-metal Stirling, heat-pipe Alkali Metal Thermoelectric Converter (AMTEC), heat-pipe Brayton, liquid-metal out-of-core thermionic, and heat-pipe Rankine systems. The least preferred systems were the liquid-metal AMTEC, heat-pipe thermophotovoltaic, liquid-metal Brayton and Rankine, and gas-cooled Brayton. The three nonheat-pipe technologies selected matched the top three nonheat-pipe systems ranked by this study.

  15. Structural analysis of cylindrical thrust chambers, volume 3

    NASA Technical Reports Server (NTRS)

    Pearson, M. L.

    1981-01-01

    A system of three computer programs is described for use in conjunction with the BOPAGE finite element program. The programs are demonstrated by analyzing cumulative plastic deformation in a regeneratively cooled rocket thrust chamber. The codes provide the capability to predict geometric and material nonlinear behavior of cyclically loaded structures without performing a cycle-by-cycle analysis over the life of the structure. The program set consists of a BOPACE restart tape reader routine, and extrapolation program and a plot package.

  16. Fully automated segmentation of whole breast in MR images by use of dynamic programming

    NASA Astrophysics Data System (ADS)

    Jiang, Luan; Lian, Yanyun; Gu, Yajia; Hu, Xiaoxin; Li, Qiang

    2014-03-01

    Breast segmentation is an important and challenging task for computerized analysis of background parenchymal enhancement (BPE) in dynamic contrast enhanced magnetic resonance images (DCE-MRI). The purpose of this study is to develop and evaluate a fully automated technique for accurate segmentation of whole breast in three-dimensional (3-D) DCE-MRI. The whole breast segmentation consists of two steps, i.e., the delineation of the chest wall and breast skin line. A sectional dynamic programming method was first designed in each 2-D slice to trace the upper and/or lower boundaries of the chest wall. The statistical distribution of gray levels of the breast skin line was employed as weighting factor to enhance the skin line, and dynamic programming was then applied to delineate breast skin line slice-by-slice within the automatically extracted volume of interest (VOI). Our method also took advantages of the continuity of chest wall and skin line across adjacent slices. Finally, the segmented breast skin line and the detected chest wall were connected to create the whole breast segmentation. The preliminary results on 70 cases show that the proposed method can obtain accurate segmentation of whole breast based on subjective observation. With the manually delineated region of 16 breasts in 8 cases, our method achieved Dice overlap measure of 92.1% +/- 1.9% (mean +/- SD) and volume agreement of 91.6% +/- 4.7% for whole breast segmentation. It took approximately 4 minutes and 2.5 minutes for our method to segment the breast in an MR scan of 160 slices and 108 slices, respectively.

  17. Involvement of Wingless\\/Armadillo signaling in the posterior sequential segmentation in the cricket, Gryllus bimaculatus (Orthoptera), as revealed by RNAi analysis

    Microsoft Academic Search

    Katsuyuki Miyawaki; Taro Mito; Isao Sarashina; Hongjie Zhang; Yohei Shinmyo; Hideyo Ohuchi; Sumihare Noji

    2004-01-01

    In insects, there are two different modes of segmentation. In the higher dipteran insects (like Drosophila), their segmentation takes place almost simultaneously in the syncytial blastoderm. By contrast, in the orthopteran insects (like Schistocerca (grasshopper)), the anterior segments form almost simultaneously in the cellular blastoderm and then the remaining posterior part elongates to form segments sequentially from the posterior proliferative

  18. Wind tunnel test IA300 analysis and results, volume 1

    NASA Technical Reports Server (NTRS)

    Kelley, P. B.; Beaufait, W. B.; Kitchens, L. L.; Pace, J. P.

    1987-01-01

    The analysis and interpretation of wind tunnel pressure data from the Space Shuttle wind tunnel test IA300 are presented. The primary objective of the test was to determine the effects of the Space Shuttle Main Engine (SSME) and the Solid Rocket Booster (SRB) plumes on the integrated vehicle forebody pressure distributions, the elevon hinge moments, and wing loads. The results of this test will be combined with flight test results to form a new data base to be employed in the IVBC-3 airloads analysis. A secondary objective was to obtain solid plume data for correlation with the results of gaseous plume tests. Data from the power level portion was used in conjunction with flight base pressures to evaluate nominal power levels to be used during the investigation of changes in model attitude, eleveon deflection, and nozzle gimbal angle. The plume induced aerodynamic loads were developed for the Space Shuttle bases and forebody areas. A computer code was developed to integrate the pressure data. Using simplified geometrical models of the Space Shuttle elements and components, the pressure data were integrated to develop plume induced force and moments coefficients that can be combined with a power-off data base to develop a power-on data base.

  19. Dynamic contact analysis technique for rapidly sliding elastic bodies with node-to-segment contact and differentiated constraints

    NASA Astrophysics Data System (ADS)

    Lee, Kisu

    2014-04-01

    For a stabilized Newmark time integration of dynamic contact problems of the rapidly sliding bodies, considering the equality and inequality contact constraints and a high-speed contact point motion sliding on the deforming contact surface, the velocity and acceleration contact constraints are derived. Also, to suppress the numerical oscillations accompanied by the node-to-segment contact of the finite element models, a pseudo-node-to-node contact technique is suggested with the linear shape function elements having the almost equal segment lengths on the contact surface. The numerical simulations are performed with a high-speed punch moving on the beam and the high-speed rotating disks to check the stability and accuracy of the solution.

  20. X-ray diffraction strain analysis of a single axial InAs1–xPx nanowire segment

    PubMed Central

    Keplinger, Mario; Mandl, Bernhard; Kriegner, Dominik; Holý, Václav; Samuelsson, Lars; Bauer, Günther; Deppert, Knut; Stangl, Julian

    2015-01-01

    The spatial strain distribution in and around a single axial InAs1–xPx hetero-segment in an InAs nanowire was analyzed using nano-focused X-ray diffraction. In connection with finite-element-method simulations a detailed quantitative picture of the nanowire’s inhomogeneous strain state was achieved. This allows for a detailed understanding of how the variation of the nanowire’s and hetero-segment’s dimensions affect the strain in its core region and in the region close to the nanowire’s side facets. Moreover, ensemble-averaging high-resolution diffraction experiments were used to determine statistical information on the distribution of wurtzite and zinc-blende crystal polytypes in the nanowires. PMID:25537589

  1. X-ray diffraction strain analysis of a single axial InAs 1-x Px nanowire segment.

    PubMed

    Keplinger, Mario; Mandl, Bernhard; Kriegner, Dominik; Holý, Václav; Samuelsson, Lars; Bauer, Günther; Deppert, Knut; Stangl, Julian

    2015-01-01

    The spatial strain distribution in and around a single axial InAs 1-x Px hetero-segment in an InAs nanowire was analyzed using nano-focused X-ray diffraction. In connection with finite-element-method simulations a detailed quantitative picture of the nanowire's inhomogeneous strain state was achieved. This allows for a detailed understanding of how the variation of the nanowire's and hetero-segment's dimensions affect the strain in its core region and in the region close to the nanowire's side facets. Moreover, ensemble-averaging high-resolution diffraction experiments were used to determine statistical information on the distribution of wurtzite and zinc-blende crystal polytypes in the nanowires. PMID:25537589

  2. Cast shadow segmentation using invariant color features

    Microsoft Academic Search

    Elena Salvador; Andrea Cavallaro; Touradj Ebrahimi

    2004-01-01

    Shadows are integral parts of natural scenes and one of the elements contributing to nat- uralness of synthetic scenes. In many image analysis and interpretation applications, shadows interfere with fundamental tasks such as object extraction and description. For this reason, shadow segmentation is an important step in image analysis. In this paper, we propose a new cast shadow segmentation algorithm

  3. Identifying Like-Minded Audiences for Global Warming Public Engagement Campaigns: An Audience Segmentation Analysis and Tool Development

    Microsoft Academic Search

    Edward W. Maibach; Anthony Leiserowitz; Connie Roser-Renouf; C. K. Mertz; Jon Moen

    2011-01-01

    BackgroundAchieving national reductions in greenhouse gas emissions will require public support for climate and energy policies and changes in population behaviors. Audience segmentation – a process of identifying coherent groups within a population – can be used to improve the effectiveness of public engagement campaigns.Methodology\\/Principal FindingsIn Fall 2008, we conducted a nationally representative survey of American adults (n = 2,164)

  4. Changes of material on surfaces of orbital space stations MIR and ISS (Russian segment) after prolonged Space exposition studied by non-destructive methods of surface analysis

    NASA Astrophysics Data System (ADS)

    Skurat, Vladimir; Berezkina, Nadezda; Leipunsky, Ilya; Zhigach, Alexey; Pshechenkov, Pavel; Artemov, Vladimir; Volkov, Ilya; Naumkin, Alexander; Afanasenkova, Elena; Sokolova, Svetlana; Kurilenok, Anna

    Complex of non-destructive methods of physical and chemical analyses of surfaces such as optical microscopy (OM), scanning electron microscopy (SEM), X-Ray electron probe analysis (XEPA), X-Ray photoelectron spectroscopy (XPS), diffuse reflection infrared Fourier transformed spectroscopy (DRIFTS) was developed for investigation of changes of materials on surfaces of spacecraft as a result of their prolonged exposition in space environment conditions. These methods were used for more than 15 years for analyses of changes of many materials (more than 100 samples) on surfaces of Russian space station MIR and ISS (Russian segment).Results of these works are generalised in the paper.

  5. Small-volume analysis of cell-cell signaling molecules in the brain.

    PubMed

    Romanova, Elena V; Aerts, Jordan T; Croushore, Callie A; Sweedler, Jonathan V

    2014-01-01

    Modern science is characterized by integration and synergy between research fields. Accordingly, as technological advances allow new and more ambitious quests in scientific inquiry, numerous analytical and engineering techniques have become useful tools in biological research. The focus of this review is on cutting edge technologies that aid direct measurement of bioactive compounds in the nervous system to facilitate fundamental research, diagnostics, and drug discovery. We discuss challenges associated with measurement of cell-to-cell signaling molecules in the nervous system, and advocate for a decrease of sample volumes to the nanoliter volume regimen for improved analysis outcomes. We highlight effective approaches for the collection, separation, and detection of such small-volume samples, present strategies for targeted and discovery-oriented research, and describe the required technology advances that will empower future translational science. PMID:23748227

  6. Small-Volume Analysis of Cell–Cell Signaling Molecules in the Brain

    PubMed Central

    Romanova, Elena V; Aerts, Jordan T; Croushore, Callie A; Sweedler, Jonathan V

    2014-01-01

    Modern science is characterized by integration and synergy between research fields. Accordingly, as technological advances allow new and more ambitious quests in scientific inquiry, numerous analytical and engineering techniques have become useful tools in biological research. The focus of this review is on cutting edge technologies that aid direct measurement of bioactive compounds in the nervous system to facilitate fundamental research, diagnostics, and drug discovery. We discuss challenges associated with measurement of cell-to-cell signaling molecules in the nervous system, and advocate for a decrease of sample volumes to the nanoliter volume regimen for improved analysis outcomes. We highlight effective approaches for the collection, separation, and detection of such small-volume samples, present strategies for targeted and discovery-oriented research, and describe the required technology advances that will empower future translational science. PMID:23748227

  7. Shared Segment Analysis and Next-Generation Sequencing Implicates the Retinoic Acid Signaling Pathway in Total Anomalous Pulmonary Venous Return (TAPVR)

    PubMed Central

    Nash, Dustin; Arrington, Cammon B.; Kennedy, Brett J.; Yandell, Mark; Wu, Wilfred; Zhang, Wenying; Ware, Stephanie; Jorde, Lynn B.; Gruber, Peter J.; Yost, H. Joseph

    2015-01-01

    Most isolated congenital heart defects are thought to be sporadic and are often ascribed to multifactorial mechanisms with poorly understood genetics. Total Anomalous Pulmonary Venous Return (TAPVR) occurs in 1 in 15,000 live-born infants and occurs either in isolation or as part of a syndrome involving aberrant left-right development. Previously, we reported causative links between TAVPR and the PDGFRA gene. TAPVR has also been linked to the ANKRD1/CARP genes. However, these genes only explain a small fraction of the heritability of the condition. By examination of phased single nucleotide polymorphism genotype data from 5 distantly related TAPVR patients we identified a single 25 cM shared, Identical by Descent genomic segment on the short arm of chromosome 12 shared by 3 of the patients and their obligate-carrier parents. Whole genome sequence (WGS) analysis identified a non-synonymous variant within the shared segment in the retinol binding protein 5 (RBP5) gene. The RBP5 variant is predicted to be deleterious and is overrepresented in the TAPVR population. Gene expression and functional analysis of the zebrafish orthologue, rbp7, supports the notion that RBP5 is a TAPVR susceptibility gene. Additional sequence analysis also uncovered deleterious variants in genes associated with retinoic acid signaling, including NODAL and retinol dehydrogenase 10. These data indicate that genetic variation in the retinoic acid signaling pathway confers, in part, susceptibility to TAPVR. PMID:26121141

  8. Texture descriptor approaches to level set segmentation in medical images

    NASA Astrophysics Data System (ADS)

    Olveres, Jimena; Nava, Rodrigo; Moya-Albor, Ernesto; Escalante-Ramírez, Boris; Brieva, Jorge; Cristóbal, Gabriel; Vallejo, Enrique

    2014-05-01

    Medical image analysis has become an important tool for improving medical diagnosis and planning treatments. It involves volume or still image segmentation that plays a critical role in understanding image content by facilitating extraction of the anatomical organ or region-of-interest. It also may help towards the construction of reliable computer-aided diagnosis systems. Specifically, level set methods have emerged as a general framework for image segmentation; such methods are mainly based on gradient information and provide satisfactory results. However, the noise inherent to images and the lack of contrast information between adjacent regions hamper the performance of the algorithms, thus, others proposals have been suggested in the literature. For instance, characterization of regions as statistical parametric models to handle level set evolution. In this paper, we study the influence of texture on a level-set-based segmentation and propose the use of Hermite features that are incorporated into the level set model to improve organ segmentation that may be useful for quantifying left ventricular blood flow. The proposal was also compared against other texture descriptors such as local binary patterns, Image derivatives, and Hounsfield low attenuation values.

  9. Semi-Automated Neuron Boundary Detection and Nonbranching Process Segmentation in Electron Microscopy Images

    SciTech Connect

    Jurrus, Elizabeth R.; Watanabe, Shigeki; Giuly, Richard J.; Paiva, Antonio R.; Ellisman, Mark H.; Jorgensen, Erik M.; Tasdizen, Tolga

    2013-01-01

    Neuroscientists are developing new imaging techniques and generating large volumes of data in an effort to understand the complex structure of the nervous system. The complexity and size of this data makes human interpretation a labor-intensive task. To aid in the analysis, new segmentation techniques for identifying neurons in these feature rich datasets are required. This paper presents a method for neuron boundary detection and nonbranching process segmentation in electron microscopy images and visualizing them in three dimensions. It combines both automated segmentation techniques with a graphical user interface for correction of mistakes in the automated process. The automated process first uses machine learning and image processing techniques to identify neuron membranes that deliniate the cells in each two-dimensional section. To segment nonbranching processes, the cell regions in each two-dimensional section are connected in 3D using correlation of regions between sections. The combination of this method with a graphical user interface specially designed for this purpose, enables users to quickly segment cellular processes in large volumes.

  10. Semi-automated Neuron Boundary Detection and Nonbranching Process Segmentation in Electron Microscopy Images

    PubMed Central

    Jurrus, Elizabeth; Watanabe, Shigeki; Giuly, Richard J.; Paiva, Antonio R. C.; Ellisman, Mark H.; Jorgensen, Erik M.; Tasdizen, Tolga

    2013-01-01

    Neuroscientists are developing new imaging techniques and generating large volumes of data in an effort to understand the complex structure of the nervous system. The complexity and size of this data makes human interpretation a labor-intensive task. To aid in the analysis, new segmentation techniques for identifying neurons in these feature rich datasets are required. This paper presents a method for neuron boundary detection and nonbranching process segmentation in electron microscopy images and visualizing them in three dimensions. It combines both automated segmentation techniques with a graphical user interface for correction of mistakes in the automated process. The automated process first uses machine learning and image processing techniques to identify neuron membranes that deliniate the cells in each two-dimensional section. To segment nonbranching processes, the cell regions in each two-dimensional section are connected in 3D using correlation of regions between sections. The combination of this method with a graphical user interface specially designed for this purpose, enables users to quickly segment cellular processes in large volumes. PMID:22644867

  11. Automated Segmentation of Hippocampal Subfields From Ultra-High Resolution In Vivo MRI

    PubMed Central

    Van Leemput, Koen; Bakkour, Akram; Benner, Thomas; Wiggins, Graham; Wald, Lawrence L.; Augustinack, Jean; Dickerson, Bradford C.; Golland, Polina; Fischl, Bruce

    2009-01-01

    Recent developments in MRI data acquisition technology are starting to yield images that show anatomical features of the hippocampal formation at an unprecedented level of detail, providing the basis for hippocampal subfield measurement. However, a fundamental bottleneck in MRI studies of the hippocampus at the subfield level is that they currently depend on manual segmentation, a laborious process that severely limits the amount of data that can be analyzed. In this article, we present a computational method for segmenting the hippocampal subfields in ultra-high resolution MRI data in a fully automated fashion. Using Bayesian inference, we use a statistical model of image formation around the hippocampal area to obtain automated segmentations. We validate the proposed technique by comparing its segmentations to corresponding manual delineations in ultra-high resolution MRI scans of 10 individuals, and show that automated volume measurements of the larger subfields correlate well with manual volume estimates. Unlike manual segmentations, our automated technique is fully reproducible, and fast enough to enable routine analysis of the hippocampal subfields in large imaging studies. PMID:19405131

  12. Segmenting images analytically in shape space

    NASA Astrophysics Data System (ADS)

    Rathi, Yogesh; Dambreville, Samuel; Niethammer, Marc; Malcolm, James; Levitt, James; Shenton, Martha E.; Tannenbaum, Allen

    2008-03-01

    This paper presents a novel analytic technique to perform shape-driven segmentation. In our approach, shapes are represented using binary maps, and linear PCA is utilized to provide shape priors for segmentation. Intensity based probability distributions are then employed to convert a given test volume into a binary map representation, and a novel energy functional is proposed whose minimum can be analytically computed to obtain the desired segmentation in the shape space. We compare the proposed method with the log-likelihood based energy to elucidate some key differences. Our algorithm is applied to the segmentation of brain caudate nucleus and hippocampus from MRI data, which is of interest in the study of schizophrenia and Alzheimer's disease. Our validation (we compute the Hausdorff distance and the DICE coefficient between the automatic segmentation and ground-truth) shows that the proposed algorithm is very fast, requires no initialization and outperforms the log-likelihood based energy.

  13. Rapid automatic segmentation of the human cerebellum and its lobules (RASCAL)--implementation and application of the patch-based label-fusion technique with a template library to segment the human cerebellum.

    PubMed

    Weier, Katrin; Fonov, Vladimir; Lavoie, Karyne; Doyon, Julien; Collins, D Louis

    2014-10-01

    Reliable and fast segmentation of the human cerebellum with its complex architecture of lobes and lobules has been a challenge for the past decades. Emerging knowledge of the functional integration of the cerebellum in various sensori-motor and cognitive-behavioral circuits demands new automatic segmentation techniques, with accuracies similar to manual segmentations, but applicable to large subject numbers in a reasonable time frame. This article presents the development and application of a novel pipeline for rapid automatic segmentation of the human cerebellum and its lobules (RASCAL) combining patch-based label-fusion and a template library of manually labeled cerebella of 16 healthy controls from the International Consortium for Brain Mapping (ICBM) database. Leave-one-out experiments revealed a good agreement between manual and automatic segmentations (Dice kappa?=?0.82). Intraclass correlation coefficients (ICC) were calculated to test reliability of segmented volumes and were highest (ICC?>?0.9) for global measures (total and hemispherical grey and white matter) followed by larger lobules of the posterior lobe (ICC?>?0.8). Further we applied the pipeline to all 152 young healthy controls of the ICBM database to look for hemispheric and gender differences. The results demonstrated larger native space volumes in men then women (mean (± SD) total cerebellar volume in women?=?217 cm(3) (± 26), men?=?259 cm(3) (± 29); P?volumes for white matter core (men?>?women) and anterior lobe volume (women?>?men). This new method shows great potential for the precise and efficient analysis of the cerebellum in large patient cohorts. PMID:24777876

  14. Automatic segmentation of anterior segment optical coherence tomography images.

    PubMed

    Williams, Dominic; Zheng, Yalin; Bao, Fangjun; Elsheikh, Ahmed

    2013-05-01

    Optical coherence tomography (OCT) images can provide quantitative measurements of the eye's entire anterior segment. A new technique founded on a newly proposed level set-based shape prior segmentation model has been developed for automatic segmentation of the cornea's anterior and posterior boundaries. This technique comprises three major steps: removal of regions containing irrelevant structures and artifacts, estimation of the cornea's location using a thresholding technique, and application of the new level set-based shape prior segmentation model to improve segmentation. The performance of our technique is compared to previously developed methods for analysis of the cornea in 33 OCT images of normal eyes, whereby manual annotations are used as a reference standard. The new technique achieves much improved concordance than previous methods, with a mean Dice's similarity coefficient of > 0.92. This demonstrates the technique's potential to provide accurate and reliable measurements of the anterior segment geometry, which is important for many applications, including the construction of representative numerical simulations of the eye's mechanical behavior. PMID:23640074

  15. Automatic segmentation of anterior segment optical coherence tomography images

    NASA Astrophysics Data System (ADS)

    Williams, Dominic; Zheng, Yalin; Bao, Fangjun; Elsheikh, Ahmed

    2013-05-01

    Optical coherence tomography (OCT) images can provide quantitative measurements of the eye's entire anterior segment. A new technique founded on a newly proposed level set-based shape prior segmentation model has been developed for automatic segmentation of the cornea's anterior and posterior boundaries. This technique comprises three major steps: removal of regions containing irrelevant structures and artifacts, estimation of the cornea's location using a thresholding technique, and application of the new level set-based shape prior segmentation model to improve segmentation. The performance of our technique is compared to previously developed methods for analysis of the cornea in 33 OCT images of normal eyes, whereby manual annotations are used as a reference standard. The new technique achieves much improved concordance than previous methods, with a mean Dice's similarity coefficient of >0.92. This demonstrates the technique's potential to provide accurate and reliable measurements of the anterior segment geometry, which is important for many applications, including the construction of representative numerical simulations of the eye's mechanical behavior.

  16. Algorithms for Fuzzy Segmentation

    Microsoft Academic Search

    Bruno M. Carvalho; C. Joe Gau; Gabor T. Herman; T. Yung Kong

    1999-01-01

    Fuzzy segmentation is an effective way of segmenting out objects in pictures containing both random noise and shading. This is illustrated both on mathematically created pictures and on some obtained from medical imaging. A theory of fuzzy segmentation is presented. To perform fuzzy segmentation, a 'connectedness map' needs to be produced. It is demonstrated that greedy algorithms for creating such

  17. Fluid Vessel Quantity using Non-Invasive PZT Technology Flight Volume Measurements Under Zero G Analysis

    NASA Technical Reports Server (NTRS)

    Garofalo, Anthony A.

    2013-01-01

    The purpose of the project is to perform analysis of data using the Systems Engineering Educational Discovery (SEED) program data from 2011 and 2012 Fluid Vessel Quantity using Non-Invasive PZT Technology flight volume measurements under Zero G conditions (parabolic Plane flight data). Also experimental planning and lab work for future sub-orbital experiments to use the NASA PZT technology for fluid volume measurement. Along with conducting data analysis of flight data, I also did a variety of other tasks. I provided the lab with detailed technical drawings, experimented with 3d printers, made changes to the liquid nitrogen skid schematics, and learned how to weld. I also programmed microcontrollers to interact with various sensors and helped with other things going on around the lab.

  18. Fluid Vessel Quantity Using Non-invasive PZT Technology Flight Volume Measurements Under Zero G Analysis

    NASA Technical Reports Server (NTRS)

    Garofalo, Anthony A

    2013-01-01

    The purpose of the project is to perform analysis of data using the Systems Engineering Educational Discovery (SEED) program data from 2011 and 2012 Fluid Vessel Quantity using Non-Invasive PZT Technology flight volume measurements under Zero G conditions (parabolic Plane flight data). Also experimental planning and lab work for future sub-orbital experiments to use the NASA PZT technology for fluid volume measurement. Along with conducting data analysis of flight data, I also did a variety of other tasks. I provided the lab with detailed technical drawings, experimented with 3d printers, made changes to the liquid nitrogen skid schematics, and learned how to weld. I also programmed microcontrollers to interact with various sensors and helped with other things going on around the lab.

  19. Congenital heart malformations in Jutland, Denmark: a three year necropsy study in children aged 0-14 years. Epidemiology and classification according to sequential segmental analysis.

    PubMed Central

    Vesterby, A; Nielsen, K; Borg, L; Paulsen, S; Baandrup, U

    1987-01-01

    The use of sequential segmental analysis for describing congenital heart malformations was the method of assessment used in a prospective necropsy study covering Jutland, a well defined geographical and demographic area of Denmark. The study group was 1,154 children of whom 261 (22.6%) had a congenital heart malformation. The most common malformations were ductus arteriosus and ventricular septal defect and there were 77 cases in which connections between chambers or between chambers and great arteries were anomalous (68 liveborn; 37 male and 31 female: nine stillborn; two male and seven female). No difference in sex distribution or seasonal variation was found between those with congenital heart disease and those without. Extracardiac malformations and chromosomal abnormalities were more often seen in children with congenital heart malformation than those without (30.3% vs 16.6%). The sequential segmental analysis is a logical and precise way of describing congenital heart malformations and it should be routinely used to classify cases of congenital heart malformation. PMID:3426901

  20. A comprehensive approach to the segmentation of multichannel three-dimensional MR brain images in multiple sclerosis?

    PubMed Central

    Datta, Sushmita; Narayana, Ponnada A.

    2013-01-01

    Accurate classification and quantification of brain tissues is important for monitoring disease progression, measurement of atrophy, and correlating magnetic resonance (MR) measures with clinical disability. Classification of MR brain images in the presence of lesions, such as multiple sclerosis (MS), is particularly challenging. Images obtained with lower resolution often suffer from partial volume averaging leading to false classifications. While partial volume averaging can be reduced by acquiring volumetric images at high resolution, image segmentation and quantification can be technically challenging. In this study, we integrated the brain anatomical knowledge with non-parametric and parametric statistical classifiers for automatically classifying tissues and lesions on high resolution multichannel three-dimensional images acquired on 60 MS brains. The results of automatic lesion segmentation were reviewed by the expert. The agreement between results obtained by the automated analysis and the expert was excellent as assessed by the quantitative metrics, low absolute volume difference percent (36.18 ± 34.90), low average symmetric surface distance (1.64 mm ± 1.30 mm), high true positive rate (84.75 ± 12.69), and low false positive rate (34.10 ± 16.00). The segmented results were also in close agreement with the corrected results as assessed by Bland–Altman and regression analyses. Finally, our lesion segmentation was validated using the MS lesion segmentation grand challenge dataset (MICCAI 2008). PMID:24179773

  1. Application of Enhanced Large Volume Injection; an Approach to the Analysis of Petroleum Hydrocarbons in Water

    Microsoft Academic Search

    P. Dellavedova; M. Vitelli; V. Ferraro; M. Di Toro; M. Santoro

    2006-01-01

    A novel method for total petroleum hydrocarbon analysis in drinking and groundwater by capillary gas chromatography has been\\u000a developed by means of a technique called Enhanced Large Volume Injection, based on an accessory and an auxiliary gas supply\\u000a using programmed temperature split\\/splitless injection with solvent venting. A detailed description of the instrumental configuration\\u000a and method optimisation is given. The system

  2. Automatic Motion Segmentation for Human Motion Synthesis

    Microsoft Academic Search

    Sebastian Schulz; Annika Woerner

    2010-01-01

    \\u000a Motion segmentation is one of the key techniques in the context of motion analysis and generation. The basic idea is to split\\u000a motion capture data into continuous segments that can be used to generate new motion sequences. For most applications, this\\u000a segmentation is done manually leading to inaccurate and inconsistent results. This makes it difficult to conceive general\\u000a methods for

  3. New evidence suggesting segmentation of Cocos Plate

    Microsoft Academic Search

    L. R. Lew; R. P. Sauermann; J. De Boer

    1985-01-01

    Compilation and analysis of geophysical and geological data indicate that the Cocos plate consists of three segments that have individual poles of rotation and independent motion vectors. Contoured heat-flow and gravity maps of the region delineate the boundaries of the segments within the Cocos plate. These segments have different focal-plane solutions along the Middle America Trench and different sedimentary-basin configurations

  4. HYDRA-II: A hydrothermal analysis computer code: Volume 2, User's manual

    SciTech Connect

    McCann, R.A.; Lowery, P.S.; Lessor, D.L.

    1987-09-01

    HYDRA-II is a hydrothermal computer code capable of three-dimensional analysis of coupled conduction, convection, and thermal radiation problems. This code is especially appropriate for simulating the steady-state performance of spent fuel storage systems. The code has been evaluated for this application for the US Department of Energy's Commercial Spent Fuel Management Program. HYDRA-II provides a finite-difference solution in cartesian coordinates to the equations governing the conservation of mass, momentum, and energy. A cylindrical coordinate system may also be used to enclose the cartesian coordinate system. This exterior coordinate system is useful for modeling cylindrical cask bodies. The difference equations for conservation of momentum incorporate directional porosities and permeabilities that are available to model solid structures whose dimensions may be smaller than the computational mesh. The equation for conservation of energy permits modeling of orthotropic physical properties and film resistances. Several automated methods are available to model radiation transfer within enclosures and from fuel rod to fuel rod. The documentation of HYDRA-II is presented in three separate volumes. Volume 1 - Equations and Numerics describes the basic differential equations, illustrates how the difference equations are formulated, and gives the solution procedures employed. This volume, Volume 2 - User's Manual, contains code flow charts, discusses the code structure, provides detailed instructions for preparing an input file, and illustrates the operation of the code by means of a sample problem. The final volume, Volume 3 - Verification/Validation Assessments, provides a comparison between the analytical solution and the numerical simulation for problems with a known solution. 6 refs.

  5. Predicting Nonauditory Adverse Radiation Effects Following Radiosurgery for Vestibular Schwannoma: A Volume and Dosimetric Analysis

    SciTech Connect

    Hayhurst, Caroline; Monsalves, Eric; Bernstein, Mark; Gentili, Fred [Gamma Knife Unit, Division of Neurosurgery, University Health Network, Toronto (Canada); Heydarian, Mostafa; Tsao, May [Radiation Medicine Program, Princess Margaret Hospital, Toronto (Canada); Schwartz, Michael [Radiation Oncology Program and Division of Neurosurgery, Sunnybrook Hospital, Toronto (Canada); Prooijen, Monique van [Radiation Medicine Program, Princess Margaret Hospital, Toronto (Canada); Millar, Barbara-Ann; Menard, Cynthia [Radiation Oncology Program, Princess Margaret Hospital, Toronto (Canada); Kulkarni, Abhaya V. [Division of Neurosurgery, Hospital for Sick Children, University of Toronto (Canada); Laperriere, Norm [Radiation Oncology Program, Princess Margaret Hospital, Toronto (Canada); Zadeh, Gelareh, E-mail: Gelareh.Zadeh@uhn.on.ca [Gamma Knife Unit, Division of Neurosurgery, University Health Network, Toronto (Canada)

    2012-04-01

    Purpose: To define clinical and dosimetric predictors of nonauditory adverse radiation effects after radiosurgery for vestibular schwannoma treated with a 12 Gy prescription dose. Methods: We retrospectively reviewed our experience of vestibular schwannoma patients treated between September 2005 and December 2009. Two hundred patients were treated at a 12 Gy prescription dose; 80 had complete clinical and radiological follow-up for at least 24 months (median, 28.5 months). All treatment plans were reviewed for target volume and dosimetry characteristics; gradient index; homogeneity index, defined as the maximum dose in the treatment volume divided by the prescription dose; conformity index; brainstem; and trigeminal nerve dose. All adverse radiation effects (ARE) were recorded. Because the intent of our study was to focus on the nonauditory adverse effects, hearing outcome was not evaluated in this study. Results: Twenty-seven (33.8%) patients developed ARE, 5 (6%) developed hydrocephalus, 10 (12.5%) reported new ataxia, 17 (21%) developed trigeminal dysfunction, 3 (3.75%) had facial weakness, and 1 patient developed hemifacial spasm. The development of edema within the pons was significantly associated with ARE (p = 0.001). On multivariate analysis, only target volume is a significant predictor of ARE (p = 0.001). There is a target volume threshold of 5 cm3, above which ARE are more likely. The treatment plan dosimetric characteristics are not associated with ARE, although the maximum dose to the 5th nerve is a significant predictor of trigeminal dysfunction, with a threshold of 9 Gy. The overall 2-year tumor control rate was 96%. Conclusions: Target volume is the most important predictor of adverse radiation effects, and we identified the significant treatment volume threshold to be 5 cm3. We also established through our series that the maximum tolerable dose to the 5th nerve is 9 Gy.

  6. Independent Orbiter Assessment (IOA): Analysis of the Electrical Power Distribution and Control Subsystem, Volume 2

    NASA Technical Reports Server (NTRS)

    Schmeckpeper, K. R.

    1987-01-01

    The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results corresponding to the Orbiter Electrical Power Distribution and Control (EPD and C) hardware. The EPD and C hardware performs the functions of distributing, sensing, and controlling 28 volt DC power and of inverting, distributing, sensing, and controlling 117 volt 400 Hz AC power to all Orbiter subsystems from the three fuel cells in the Electrical Power Generation (EPG) subsystem. Volume 2 continues the presentation of IOA analysis worksheets and contains the potential critical items list.

  7. Magnetic resonance velocity imaging derived pressure differential using control volume analysis

    PubMed Central

    2011-01-01

    Background Diagnosis and treatment of hydrocephalus is hindered by a lack of systemic understanding of the interrelationships between pressures and flow of cerebrospinal fluid in the brain. Control volume analysis provides a fluid physics approach to quantify and relate pressure and flow information. The objective of this study was to use control volume analysis and magnetic resonance velocity imaging to non-invasively estimate pressure differentials in vitro. Method A flow phantom was constructed and water was the experimental fluid. The phantom was connected to a high-resolution differential pressure sensor and a computer controlled pump producing sinusoidal flow. Magnetic resonance velocity measurements were taken and subsequently analyzed to derive pressure differential waveforms using momentum conservation principles. Independent sensor measurements were obtained for comparison. Results Using magnetic resonance data the momentum balance in the phantom was computed. The measured differential pressure force had amplitude of 14.4 dynes (pressure gradient amplitude 0.30 Pa/cm). A 12.5% normalized root mean square deviation between derived and directly measured pressure differential was obtained. These experiments demonstrate one example of the potential utility of control volume analysis and the concepts involved in its application. Conclusions This study validates a non-invasive measurement technique for relating velocity measurements to pressure differential. These methods may be applied to clinical measurements to estimate pressure differentials in vivo which could not be obtained with current clinical sensors. PMID:21414222

  8. 1 | P a g e Corpus Callosum deformation analysis in Multiple Sclerosis

    E-print Network

    Paris-Sud XI, Université de

    1 | P a g e Corpus Callosum deformation analysis in Multiple Sclerosis *F. Derraz, **A. Pinti, *B to Multiple Sclerosis (MS) lesion. We propose an approach for 3D segmentation of the volume of interest based the criterion established in this paper. Key words : Segmentation, multiple sclerosis, corpus callosum, medical

  9. SRB Environment Evaluation and Analysis. Volume 3: ASRB Plume Induced Environments

    NASA Technical Reports Server (NTRS)

    Bender, R. L.; Brown, J. R.; Reardon, J. E.; Everson, J.; Coons, L. W.; Stuckey, C. I.; Fulton, M. S.

    1991-01-01

    Contract NAS8-37891 was expanded in late 1989 to initiate analysis of Shuttle plume induced environments as a result of the substitution of the Advanced Solid Rocket Booster (ASRB) for the Redesigned Solid Rocket Booster (RSRB). To support this analysis, REMTECH became involved in subscale and full-scale solid rocket motor test programs which further expanded the scope of work. Later contract modifications included additional tasks to produce initial design cycle environments and to specify development flight instrumentation. Volume 3 of the final report describes these analyses and contains a summary of reports resulting from various studies.

  10. Fabrication, testing, and analysis of anisotropic carbon/glass hybrid composites: volume 1: technical report.

    SciTech Connect

    Wetzel, Kyle K. (Wetzel Engineering, Inc. Lawrence, Kansas); Hermann, Thomas M. (Wichita state University, Wichita, Kansas); Locke, James (Wichita state University, Wichita, Kansas)

    2005-11-01

    Anisotropic carbon/glass hybrid composite laminates have been fabricated, tested, and analyzed. The laminates have been fabricated using vacuum-assisted resin transfer molding (VARTM). Five fiber complexes and a two-part epoxy resin system have been used in the study to fabricate panels of twenty different laminate constructions. These panels have been subjected to physical testing to measure density, fiber volume fraction, and void fraction. Coupons machined from these panels have also been subjected to mechanical testing to measure elastic properties and strength of the laminates using tensile, compressive, transverse tensile, and in-plane shear tests. Interlaminar shear strength has also been measured. Out-of-plane displacement, axial strain, transverse strain, and inplane shear strain have also been measured using photogrammetry data obtained during edgewise compression tests. The test data have been reduced to characterize the elastic properties and strength of the laminates. Constraints imposed by test fixtures might be expected to affect measurements of the moduli of anisotropic materials; classical lamination theory has been used to assess the magnitude of such effects and correct the experimental data for the same. The tensile moduli generally correlate well with experiment without correction and indicate that factors other than end constraints dominate. The results suggest that shear moduli of the anisotropic materials are affected by end constraints. Classical lamination theory has also been used to characterize the level of extension-shear coupling in the anisotropic laminates. Three factors affecting the coupling have been examined: the volume fraction of unbalanced off-axis layers, the angle of the off-axis layers, and the composition of the fibers (i.e., carbon or glass) used as the axial reinforcement. The results indicate that extension/shear coupling is maximized with the least loss in axial tensile stiffness by using carbon fibers oriented 15{sup o} from the long axis for approximately two-thirds of the laminate volume (discounting skin layers), with reinforcing carbon fibers oriented axially comprising the remaining one-third of the volume. Finite element analysis of each laminate has been performed to examine first ply failure. Three failure criteria--maximum stress, maximum strain, and Tsai-Wu--have been compared. Failure predicted by all three criteria proves generally conservative, with the stress-based criteria the most conservative. For laminates that respond nonlinearly to loading, large error is observed in the prediction of failure using maximum strain as the criterion. This report documents the methods and results in two volumes. Volume 1 contains descriptions of the laminates, their fabrication and testing, the methods of analysis, the results, and the conclusions and recommendations. Volume 2 contains a comprehensive summary of the individual test results for all laminates.

  11. Reproducible isolation of distinct, overlapping segments of the phosphoproteome

    E-print Network

    Cai, Long

    Reproducible isolation of distinct, overlapping segments of the phosphoproteome Bernd Bodenmiller1 detect different, partially overlapping segments of the phosphoproteome and that, at present, no single method is sufficient for a comprehensive phosphoproteome analysis. Among the several hundred known

  12. Brain Volumes in Schizophrenia: A Meta-Analysis in Over 18 000 Subjects

    PubMed Central

    Haijma, Sander V.

    2013-01-01

    Although structural brain alterations in schizophrenia have been demonstrated extensively, their quantitative distribution has not been studied over the last 14 years despite advances in neuroimaging. Moreover, a volumetric meta-analysis has not been conducted in antipsychotic-naive patients. Therefore, meta-analysis on cross-sectional volumetric brain alterations in both medicated and antipsychotic-naive patients was conducted. Three hundred seventeen studies published from September 1, 1998 to January 1, 2012 comprising over 9000 patients were selected for meta-analysis, including 33 studies in antipsychotic-naive patients. In addition to effect sizes, potential modifying factors such as duration of illness, sex composition, current antipsychotic dose, and intelligence quotient matching status of participants were extracted where available. In the sample of medicated schizophrenia patients (n = 8327), intracranial and total brain volume was significantly decreased by 2.0% (effect size d = ?0.17) and 2.6% (d = ?0.30), respectively. Largest effect sizes were observed for gray matter structures, with effect sizes ranging from ?0.22 to ?0.58. In the sample of antipsychotic-naive patients (n = 771), volume reductions in caudate nucleus (d = ?0.38) and thalamus (d = ?0.68) were more pronounced than in medicated patients. White matter volume was decreased to a similar extent in both groups, while gray matter loss was less extensive in antipsychotic-naive patients. Gray matter reduction was associated with longer duration of illness and higher dose of antipsychotic medication at time of scanning. Therefore, brain loss in schizophrenia is related to a combination of (early) neurodevelopmental processes—reflected in intracranial volume reduction—as well as illness progression. PMID:23042112

  13. Modifications to a two-control-volume, frequency dependent, transfer-function analysis of hole-pattern gas annular seals 

    E-print Network

    Shin, Yoon Shik

    2007-04-25

    A rotordynamic analysis of hole-pattern gas annular seals using a two-control-volume model, Ha and Childs and frequency dependent transfer-function model, Kleynhans and Childs is modified with four features. The energy ...

  14. Final safety analysis report for the Galileo Mission: Volume 1, Reference design document

    SciTech Connect

    Not Available

    1988-05-01

    The Galileo mission uses nuclear power sources called Radioisotope Thermoelectric Generators (RTGs) to provide the spacecraft's primary electrical power. Because these generators contain nuclear material, a Safety Analysis Report (SAR) is required. A preliminary SAR and an updated SAR were previously issued that provided an evolving status report on the safety analysis. As a result of the Challenger accident, the launch dates for both Galileo and Ulysses missions were later rescheduled for November 1989 and October 1990, respectively. The decision was made by agreement between the DOE and the NASA to have a revised safety evaluation and report (FSAR) prepared on the basis of these revised vehicle accidents and environments. The results of this latest revised safety evaluation are presented in this document (Galileo FSAR). Volume I, this document, provides the background design information required to understand the analyses presented in Volumes II and III. It contains descriptions of the RTGs, the Galileo spacecraft, the Space Shuttle, the Inertial Upper Stage (IUS), the trajectory and flight characteristics including flight contingency modes, and the launch site. There are two appendices in Volume I which provide detailed material properties for the RTG.

  15. A comparison of volume-based and surface-based multi-voxel pattern analysis.

    PubMed

    Oosterhof, Nikolaas N; Wiestler, Tobias; Downing, Paul E; Diedrichsen, Jörn

    2011-05-15

    For functional magnetic resonance imaging (fMRI), multi-voxel pattern analysis (MVPA) has been shown to be a sensitive method to detect areas that encode certain stimulus dimensions. By moving a searchlight through the volume of the brain, one can continuously map the information content about the experimental conditions of interest to the brain. Traditionally, the searchlight is defined as a volume sphere that does not take into account the anatomy of the cortical surface. Here we present a method that uses a cortical surface reconstruction to guide voxel selection for information mapping. This approach differs in two important aspects from a volume-based searchlight definition. First, it uses only voxels that are classified as grey matter based on an anatomical scan. Second, it uses a surface-based geodesic distance metric to define neighbourhoods of voxels, and does not select voxels across a sulcus. We study here the influence of these two factors onto classification accuracy and onto the spatial specificity of the resulting information map. In our example data set, participants pressed one of four fingers while undergoing fMRI. We used MVPA to identify regions in which local fMRI patterns can successfully discriminate which finger was moved. We show that surface-based information mapping is a more sensitive measure of local information content, and provides better spatial selectivity. This makes surface-based information mapping a useful technique for a data-driven analysis of information representation in the cerebral cortex. PMID:20621701

  16. High volume methane gas hydrate deposits in fine grained sediments from the Krishna-Godavari Basin: Analysis from Micro CT scanning

    NASA Astrophysics Data System (ADS)

    Rees, E. V.; Clayton, C.; Priest, J.; Schultheiss, P. J.

    2009-12-01

    The Indian National Gas Hydrate Program (NGHP) Expedition 1, of 2006, investigated several methane gas hydrate deposits on the continental shelf around the coast of India. Using pressure coring techniques (HYACINTH and PCS), intact gas-hydrate bearing, fine-grained sediment cores were recovered during the expedition. Once recovered, these cores were rapidly depressurized and submerged in liquid nitrogen, therefore preserving the structure and form of the hydrate within the host sediment. High resolution X-Ray CT scanning was later employed to image the internal structure of the gas hydrate, analyze the trends in vein orientation, and collect volumetric data. A scanning resolution of 0.08mm allowed for a detailed view of the three-dimensional distribution of the hydrate within the sediment from which detailed analysis of vein orientation could be made. Two distinct directions of vein growth were identified in each core section studied, which suggested the presence of a specific stress regime in the Krishna-Godavari basin during hydrate formation. In addition, image segmentation of gas hydrate from the sediment allowed for volumetric analysis of the hydrate content within each core section. Results from this analysis showed that high volumes of gas hydrate, up to approximately 70% of the pore space, were present. This high volume of methane gas hydrate can have a significant impact on the stability of the host sediment if dissociation of the hydrate were to occur in-situ, through the development of excess pore pressure, increase in water content and change in salinity of the host sediment.

  17. Transactions of NAMRI/SME 351 Volume 32, 2004 FOURIER ANALYSIS OF X-RAY MICRODIFFRACTION PROFILES TO

    E-print Network

    Yao, Y. Lawrence

    Transactions of NAMRI/SME 351 Volume 32, 2004 FOURIER ANALYSIS OF X-RAY MICRODIFFRACTION PROFILES, IBM T. J. Watson Research Center Yorktown Heights, NY 10598 KEYWORDS Fourier analysis, Microdifraction analyzed via Fourier analysis for single crystal Aluminum and Copper samples subjected to micro scale laser

  18. THE WATERSHED TRANSFORMATION APPLIED TO IMAGE SEGMENTATION

    Microsoft Academic Search

    S. BEUCHER

    1991-01-01

    Image segmentation by mathematical morphology is a methodology based upon the notions of watershed and homotopy modification. This paper aims at introducing this methodology through various examples of segmentation in materials sciences, electron microscopy and scene analysis. First, we define our basic tool, the watershed transform. We show that this transformation can be built by implementing a flooding process on

  19. Probabilities for Jumping Fault Segment Stepovers

    NASA Astrophysics Data System (ADS)

    Shaw, B. E.; Dieterich, J. H.

    2006-12-01

    Seismic hazard analysis relies heavily on the segmentation of faults. The ability of ruptures to break multiple segments has a big impact on estimated hazard. Current practice for estimating multiple segment breakage relies on panels of experts voting on their opinions for each case. Here, we explore the probability of elastodynamic ruptures jumping segment stepovers in numerical simulations of segmented fault systems. We find a simple functional form for the probability of jumping a segment stepover as a function of stepover distance: an exponential falloff with distance. We suggest this simple parameterization of jumping probabilities, combined with sparse observational data to fix the lengthscale parameter, as a new approach to estimating multisegment earthquake hazard.

  20. Probabilities for jumping fault segment stepovers

    NASA Astrophysics Data System (ADS)

    Shaw, Bruce E.; Dieterich, James H.

    2007-01-01

    Seismic hazard analysis relies heavily on the segmentation of faults. The ability of ruptures to break multiple segments has a big impact on estimated hazard. Current practice for estimating multiple segment breakage relies on panels of experts voting on their opinions for each case. Here, we explore the probability of elastodynamic ruptures jumping segment stepovers in numerical simulations of segmented fault systems. We find a simple functional form for the probability of jumping a segment stepover as a function of stepover distance: an exponential falloff with distance. We suggest this simple parameterization of jumping probabilities, combined with sparse observational data to fix the lengthscale parameter, as a new approach to estimating multisegment earthquake hazard.