WorldWideScience

Sample records for segmental construction

  1. Construction of precast high performance concrete segmental bridges.

    OpenAIRE

    Ruiz Ripoll, Lidia

    2016-01-01

    The construction of both medium and long span precast concrete segmental bridges is widely spread throughout Spain. Usually, the segments have multiple-keyed epoxy joints, and are assembled by internal prestressing. Yet, there is a more recent type of bridge with dry joints and external prestressing. In these last ones, shear is transferred through physical support between keys and friction between faces of the compressed joint. This shear force is evaluated using friction coefficients from t...

  2. Five low energy phosphorene allotropes constructed through gene segments recombination.

    Science.gov (United States)

    He, Chaoyu; Zhang, ChunXiao; Tang, Chao; Ouyang, Tao; Li, Jin; Zhong, Jianxin

    2017-04-27

    Based on the crystal structures of the previously proposed low energy η-P and θ-P, five new phosphorene allotropes were predicted through gene segments recombination method. These five new phosphorene allotropes are confirmed dynamically stable and energetically more favorable than their parents (η-P and θ-P). Especially, the XX-XX type G1-P is confirmed energetically more favorable than most of all the previously proposed phosphorene allotropes, including black phosphorene and blue phosphorene, which is highly expected to be synthesized in future experiment through vapor deposition or epitaxial growth method like blue β-P. The calculated results also show that such a new promising phosphorene allotrope G1-P is a potential candidate for application in nano-electronics according to its middle band gap of about 1.491 eV from DFT-HSE06 calculation.

  3. Segmental vs non-segmental thoracic pedicle screws constructs in adolescent idiopathic scoliosis: is there any implant alloy effect?

    Science.gov (United States)

    Di Silvestre, Mario; Bakaloudis, Georgeous; Ruosi, Carlo; Pipola, Valerio; Colella, Gianluca; Greggi, Tiziana; Ruffilli, Alberto; Vommaro, Francesco

    2017-10-01

    The aim of this study is to understand how many anchor sites are necessary to obtain maximum posterior correction of idiopathic scoliotic curve and if the alloy of instrumentation, stainless steel or titanium, may have a role in the percent of scoliosis correction. We reviewed 143 consecutive patients, affected by AIS (Lenke 1-2), who underwent a posterior spinal fusion with pedicle screw-only instrumentation between 2002 and 2005. According to the implant density and alloy used we divided the cohort in four groups. All 143 patients were reviewed at an average follow-up of 7, 2 years, the overall final main thoracic curve correction averaged 61.4%, whereas the implant density within the major curve averaged 71%. A significant correlation was observed between final% MT correction and preoperative MT flexibility and implant density. When stainless steel instrumentation is used non-segmental pedicle screw constructs seem to be equally effective as segmental instrumentations in obtaining satisfactory results in patients with main thoracic AIS. When the implant alloy used is titanium one, an implant density of ≥60% should be guaranteed to achieve similar results.

  4. Outdoor Illegal Construction Identification Algorithm Based on 3D Point Cloud Segmentation

    Science.gov (United States)

    An, Lu; Guo, Baolong

    2018-03-01

    Recently, various illegal constructions occur significantly in our surroundings, which seriously restrict the orderly development of urban modernization. The 3D point cloud data technology is used to identify the illegal buildings, which could address the problem above effectively. This paper proposes an outdoor illegal construction identification algorithm based on 3D point cloud segmentation. Initially, in order to save memory space and reduce processing time, a lossless point cloud compression method based on minimum spanning tree is proposed. Then, a ground point removing method based on the multi-scale filtering is introduced to increase accuracy. Finally, building clusters on the ground can be obtained using a region growing method, as a result, the illegal construction can be marked. The effectiveness of the proposed algorithm is verified using a publicly data set collected from the International Society for Photogrammetry and Remote Sensing (ISPRS).

  5. Robust Segmentation of Planar and Linear Features of Terrestrial Laser Scanner Point Clouds Acquired from Construction Sites

    Science.gov (United States)

    Maalek, Reza; Lichti, Derek D; Ruwanpura, Janaka Y

    2018-01-01

    Automated segmentation of planar and linear features of point clouds acquired from construction sites is essential for the automatic extraction of building construction elements such as columns, beams and slabs. However, many planar and linear segmentation methods use scene-dependent similarity thresholds that may not provide generalizable solutions for all environments. In addition, outliers exist in construction site point clouds due to data artefacts caused by moving objects, occlusions and dust. To address these concerns, a novel method for robust classification and segmentation of planar and linear features is proposed. First, coplanar and collinear points are classified through a robust principal components analysis procedure. The classified points are then grouped using a new robust clustering method, the robust complete linkage method. A robust method is also proposed to extract the points of flat-slab floors and/or ceilings independent of the aforementioned stages to improve computational efficiency. The applicability of the proposed method is evaluated in eight datasets acquired from a complex laboratory environment and two construction sites at the University of Calgary. The precision, recall, and accuracy of the segmentation at both construction sites were 96.8%, 97.7% and 95%, respectively. These results demonstrate the suitability of the proposed method for robust segmentation of planar and linear features of contaminated datasets, such as those collected from construction sites. PMID:29518062

  6. Construction of Korean male tomographic model segmented from PET-CT data

    International Nuclear Information System (INIS)

    Lee, Choon Sik; Park, Sang Kyun; Lee, Jai Ki

    2004-01-01

    Tomographic human models provide currently the most realistic representation of human anatomy for radiation dosimetry calculation. Most of the models have been constructed by using computed tomographic (CT) or magnetic resonance (MR) images obtained from a single individual. Each scan has its inherent advantages and disadvantages. CT scan gives a considerable radiation dose to a subject, and MR scan takes too long time to get clear images of an immobile subject. An emerging source of medical images for the construction of tomographic models is PET-CT, which is performed when looking for cancer. In this study, a tomographic model of Korean adult male was developed by processing whole-body CT images of a PET-CT-scanned healthy volunteer. The 343 slices of the CT images were semi-automatically segmented layer by layer using a graphic software and screen digitizer. The 3rd Korean tomographic model, named KRMAN-2, consisting of 300x150x344 voxels of a size of 2x2x5mm 3 , was constructed. Examples of application to Monte Carlo radiation dosimetry calculation in idealized whole-body irradiations were given and discussed

  7. Investigation of efficiency of air cleaning from acetone using a segmental construction biofilter

    Directory of Open Access Journals (Sweden)

    Denas Bacevičius

    2015-10-01

    Full Text Available Volatile organic compounds, e. g. acetone, have a direct impact on climate change, decrease of ozone in the air, and on the growth of greenhouse effect. One of the most popular air purifying methods from VOC is a biological air cleaning. Experimental investigations were conducted to determine the efficiency of the new structure of biofilter with polypropylene plates segments. During the investigations the efficiency of segmental construction biofilter of air purification at different initial concentrations of pollutants was determined. Different concentrations of pollutants were estimated during the acetone dilution with water. During the tests the efficiency of biofilter air purification from acetone vapor and its change under different concentrations of vapors was set. Based on test results, the maximum efficiency of biofilter air purification was up to 93%. Studies have shown that increasing the allowable pollutant concentration, the efficiency of air purification unit decreases. Increasing the concentration of supplied acetone vapor into the biofilter from 232 to 701 mg/m3, cleaning efficiency decreased from 92.8 to 82.3%. Since microorganisms fail to oxidize organic compounds, the filter works better at lower initial concentrations of pollutants.

  8. Patch-based image segmentation of satellite imagery using minimum spanning tree construction

    Energy Technology Data Exchange (ETDEWEB)

    Skurikhin, Alexei N [Los Alamos National Laboratory

    2010-01-01

    We present a method for hierarchical image segmentation and feature extraction. This method builds upon the combination of the detection of image spectral discontinuities using Canny edge detection and the image Laplacian, followed by the construction of a hierarchy of segmented images of successively reduced levels of details. These images are represented as sets of polygonized pixel patches (polygons) attributed with spectral and structural characteristics. This hierarchy forms the basis for object-oriented image analysis. To build fine level-of-detail representation of the original image, seed partitions (polygons) are built upon a triangular mesh composed of irregular sized triangles, whose spatial arrangement is adapted to the image content. This is achieved by building the triangular mesh on the top of the detected spectral discontinuities that form a network of constraints for the Delaunay triangulation. A polygonized image is represented as a spatial network in the form of a graph with vertices which correspond to the polygonal partitions and graph edges reflecting pairwise partitions relations. Image graph partitioning is based on the iterative graph oontraction using Boruvka's Minimum Spanning Tree algorithm. An important characteristic of the approach is that the agglomeration of partitions is constrained by the detected spectral discontinuities; thus the shapes of agglomerated partitions are more likely to correspond to the outlines of real-world objects.

  9. Along-Axis Structure and Crustal Construction Processes of Spreading Segments in Iceland: Implications for Magmatic Rifts

    Science.gov (United States)

    Siler, D. L.; Karson, J. A.

    2017-10-01

    Magmatic rift systems are composed of discrete spreading segments defined by morphologic, structural, and volcanic features that vary systematically along strike. In Iceland, structural features mapped in the glaciated and exhumed Miocene age upper crust correlate with analogous features in the seismically and volcanically active neovolcanic zone. Integrating information from both the active rift zones and ancient crust provides a three-dimensional perspective of crustal structure and the volcanic and tectonic processes that construct crust along spreading segments. Crustal exposures in the Skagi region of northern Iceland reveal significant along-strike variations in geologic structure. The upper crust at exhumed magmatic centers (segment centers) is characterized by a variety of intrusive rocks, high-temperature hydrothermal alteration, and geologic evidence for kilometer-scale subsidence. In contrast, the upper crust along segment limbs, which extend along strike from magmatic centers, is characterized by thick sections of gently dipping lava flows, cut by varying proportions of subvertical dikes. This structure implies relatively minor upper crustal subsidence and lateral dike intrusion. The differing modes of subsidence beneath segment centers and segment limbs require along-axis mass redistribution in the underlying upper, middle, and lower crust during crustal construction. This along-axis material transport is accomplished through lateral dike intrusion in the upper crust and by along-axis flow of magmatic to high-temperature solid-state gabbroic material in the middle and lower crust. These processes, inferred from outcrop evidence in Skagi, are consistent with processes inferred to be important during active rifting in Iceland and at analogous magmatic oceanic and continental rifts.

  10. Resulting long-term intestinal motility in dogs following construction of a reversed jejunal segment after extensive small bowel resection.

    Science.gov (United States)

    Uchiyama, M; Iwafuchi, M; Ohsawa, Y; Yagi, M; Iinuma, Y; Ohtani, S

    1994-10-01

    To evaluate the long-term function and effective motility of a reversed jejunal segment after extensive small bowel resection, the authors continuously measured postoperative bowel motility during interdigestive and postprandial periods in conscious dogs 6 to 10 months after surgery. The long-term findings were compared with previously reported short-term results measured 2 to 4 weeks after the operation. In the long-term follow-up dogs with a 20-cm reversed jejunal segment constructed after extensive (75% to 80%) small bowel resection, the fasting duodenal migrating myoelectric (or motor) complex (MMC) was often interrupted in the jejunum above the reversed segment, and did not migrate smoothly to the reversed segment or terminal ileum. The MMCs arising from the duodenum predominantly propagated to the ileum through the inherent anatomic continuity of the bowel. In addition, brief small discordant contractions were frequent in the reversed segment and the jejunum, above the proximal anastomosis. These findings are similar to those of the MMC propagation pattern noted 2 to 4 weeks after surgery. However, the postprandial duration without duodenal MMC activity was significantly shorter in the dogs with long-term follow-up than in those with short-term follow-up (both were longer than in control dogs). Marked dilatation of the jejunum and reversed jejunal segment was noted across the proximal anastomosis. These results suggest that the transit time and passage of intestinal contents can be delayed and stagnated for at least 10 months after extensive small bowel resection with a 20-cm reversed jejunal segment.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Construction of carrier state viruses with partial genomes of the segmented dsRNA bacteriophages

    International Nuclear Information System (INIS)

    Sun Yang; Qiao Xueying; Mindich, Leonard

    2004-01-01

    The cystoviridae are bacteriophages with genomes of three segments of dsRNA enclosed within a polyhedral capsid. Two members of this family, PHI6 and PHI8, have been shown to form carrier states in which the virus replicates as a stable episome in the host bacterium while expressing reporter genes such as kanamycin resistance or lacα. The carrier state does not require the activity of all the genes necessary for phage production. It is possible to generate carrier states by infecting cells with virus or by electroporating nonreplicating plasmids containing cDNA copies of the viral genomes into the host cells. We have found that carrier states in both PHI6 and PHI8 can be formed at high frequency with all three genomic segments or with only the large and small segments. The large genomic segment codes for the proteins that constitute the inner core of the virus, which is the structure responsible for the packaging and replication of the genome. In PHI6, a carrier state can be formed with the large and middle segment if mutations occur in the gene for the major structural protein of the inner core. In PHI8, carrier state formation requires the activity of genes 8 and 12 of segment S

  12. Occupational health and safety issues in the informal economic segment of Pakistan: a survey of construction sites.

    Science.gov (United States)

    Ahmed, Ishfaq; Shaukat, Muhammad Zeeshan; Usman, Ahmad; Nawaz, Muhammad Musarrat; Nazir, Mian Sajid

    2018-06-01

    This research covers the current status of occupational health and safety (OHS)-related practices in the informal construction segment of Pakistan. Data were collected, through interviews, from 316 construction sites employing 3577 workers. The results of the study reveal that both employers and workers lack knowledge of OHS laws/standards and no practices of this nature are enacted at these construction sites. Alarmingly, work-related accidents, whenever they happen, are not given due attention and there is no formal injury-report system. The informal construction industry employs a huge portion of the informal workforce, and lack of OHS happens at tremendous human cost. These research findings may thus play their role in strengthening the case for reforms in the sector. This study, if properly utilized, may also enable employers of the sector by increasing their knowledge about OHS practices and, as a result, trying to offer safer environments for their workers.

  13. Market segmentation and analysis of Japan's residential post and beam construction market.

    Science.gov (United States)

    Joseph A. Roos; Ivan L. Eastin; Hisaaki Matsuguma

    2005-01-01

    A mail survey of Japanese post and beam builders was conducted to measure their level of ethnocentrism, market orientation, risk aversion, and price consciousness. The data were analyzed utilizing factor and cluster analysis. The results showed that Japanese post and beam builders can be divided into three distinct market segments: open to import...

  14. E-Learning System Using Segmentation-Based MR Technique for Learning Circuit Construction

    Science.gov (United States)

    Takemura, Atsushi

    2016-01-01

    This paper proposes a novel e-Learning system using the mixed reality (MR) technique for technical experiments involving the construction of electronic circuits. The proposed system comprises experimenters' mobile computers and a remote analysis system. When constructing circuits, each learner uses a mobile computer to transmit image data from the…

  15. Engraftment of Prevascularized, Tissue Engineered Constructs in a Novel Rabbit Segmental Bone Defect Model

    Directory of Open Access Journals (Sweden)

    Alexandre Kaempfen

    2015-06-01

    Full Text Available The gold standard treatment of large segmental bone defects is autologous bone transfer, which suffers from low availability and additional morbidity. Tissue engineered bone able to engraft orthotopically and a suitable animal model for pre-clinical testing are direly needed. This study aimed to evaluate engraftment of tissue-engineered bone with different prevascularization strategies in a novel segmental defect model in the rabbit humerus. Decellularized bone matrix (Tutobone seeded with bone marrow mesenchymal stromal cells was used directly orthotopically or combined with a vessel and inserted immediately (1-step or only after six weeks of subcutaneous “incubation” (2-step. After 12 weeks, histological and radiological assessment was performed. Variable callus formation was observed. No bone formation or remodeling of the graft through TRAP positive osteoclasts could be detected. Instead, a variable amount of necrotic tissue formed. Although necrotic area correlated significantly with amount of vessels and the 2-step strategy had significantly more vessels than the 1-step strategy, no significant reduction of necrotic area was found. In conclusion, the animal model developed here represents a highly challenging situation, for which a suitable engineered bone graft with better prevascularization, better resorbability and higher osteogenicity has yet to be developed.

  16. Construction of chromosome segment substitution lines enables QTL mapping for flowering and morphological traits in Brassica rapa

    Directory of Open Access Journals (Sweden)

    Xiaonan eLi

    2015-06-01

    Full Text Available Chromosome segment substitution lines (CSSLs represent a powerful method for precise quantitative trait loci (QTL detection of complex agronomical traits in plants. In this study, we used a marker-assisted backcrossing strategy to develop a population consisting of 63 CSSLs, derived from backcrossing of the F1 generated from a cross between two Brassica rapa subspecies: ‘Chiifu’ (ssp. pekinensis, the Brassica A genome-represented line used as the donor, and ‘49caixin’ (ssp. parachinensis, a non-heading cultivar used as the recipient. The 63 CSSLs covered 87.95% of the B. rapa genome. Among them, 39 lines carried a single segment; 15 lines, two segments; and nine lines, three or more segments of the donor parent chromosomes. To verify the potential advantage of these CSSL lines, we used them to locate QTL for six morphology-related traits. A total of 58 QTL were located on eight chromosomes for all six traits: 17 for flowering time, 14 each for bolting time and plant height, 6 for plant diameter, 2 for leaf width, and 5 for flowering stalk diameter. Co-localized QTL were mainly distributed on eight genomic regions in A01, A02, A05, A06, A08, A09, and A10, present in the corresponding CSSLs. Moreover, new chromosomal fragments that harbored QTL were identified using the findings of previous studies. The CSSL population constructed in our study paves the way for fine mapping and cloning of candidate genes involved in late bolting, flowering, and plant architecture-related traits in B. rapa. Furthermore, it has great potential for future marker-aided gene/QTL pyramiding of other interesting traits in B. rapa breeding.

  17. Construction of a cDNA library from human retinal pigment epithelial cells challenged with rod outer segments.

    Science.gov (United States)

    Cavaney, D M; Rakoczy, P E; Constable, I J

    1995-05-01

    To study genes expressed by retinal pigment epithelial (RPE) cells during phagocytosis and digestion of rod outer segments (ROS), a complementary (c)DNA library was produced using an in-vitro model. The cDNA library can be used to study molecular changes which contribute to the development of diseases due to a failure in outer segment phagocytosis and digestion by RPE cells. Here we demonstrate a way to study genes and their functions using a molecular biological approach and describing the first step involved in this process, the construction of a cDNA library. Human RPE cells obtained from the eyes of a seven-year-old donor were cultured and challenged with bovine ROS. The culture was harvested and total RNA was extracted. Complementary DNA was transcribed from the messenger (m)RNA and was directionally cloned into the LambdaGEM-4 bacteriophage vector successfully. Some clones were picked and the DNA extracted, to determine the size of the inserts as a measure of the quality of the library. Molecular biology and cell culture are important tools to be used in eye research, especially in areas where tissue is limiting and animal models are not available. We now have a ROS challenged RPE cDNA library which will be used to identify genes responsible for degrading phagocytosed debris within the retinal pigment epithelium.

  18. Fast and accurate semi-automated segmentation method of spinal cord MR images at 3T applied to the construction of a cervical spinal cord template.

    Directory of Open Access Journals (Sweden)

    Mohamed-Mounir El Mendili

    Full Text Available To design a fast and accurate semi-automated segmentation method for spinal cord 3T MR images and to construct a template of the cervical spinal cord.A semi-automated double threshold-based method (DTbM was proposed enabling both cross-sectional and volumetric measures from 3D T2-weighted turbo spin echo MR scans of the spinal cord at 3T. Eighty-two healthy subjects, 10 patients with amyotrophic lateral sclerosis, 10 with spinal muscular atrophy and 10 with spinal cord injuries were studied. DTbM was compared with active surface method (ASM, threshold-based method (TbM and manual outlining (ground truth. Accuracy of segmentations was scored visually by a radiologist in cervical and thoracic cord regions. Accuracy was also quantified at the cervical and thoracic levels as well as at C2 vertebral level. To construct a cervical template from healthy subjects' images (n=59, a standardization pipeline was designed leading to well-centered straight spinal cord images and accurate probability tissue map.Visual scoring showed better performance for DTbM than for ASM. Mean Dice similarity coefficient (DSC was 95.71% for DTbM and 90.78% for ASM at the cervical level and 94.27% for DTbM and 89.93% for ASM at the thoracic level. Finally, at C2 vertebral level, mean DSC was 97.98% for DTbM compared with 98.02% for TbM and 96.76% for ASM. DTbM showed similar accuracy compared with TbM, but with the advantage of limited manual interaction.A semi-automated segmentation method with limited manual intervention was introduced and validated on 3T images, enabling the construction of a cervical spinal cord template.

  19. Fast and accurate semi-automated segmentation method of spinal cord MR images at 3T applied to the construction of a cervical spinal cord template.

    Science.gov (United States)

    El Mendili, Mohamed-Mounir; Chen, Raphaël; Tiret, Brice; Villard, Noémie; Trunet, Stéphanie; Pélégrini-Issac, Mélanie; Lehéricy, Stéphane; Pradat, Pierre-François; Benali, Habib

    2015-01-01

    To design a fast and accurate semi-automated segmentation method for spinal cord 3T MR images and to construct a template of the cervical spinal cord. A semi-automated double threshold-based method (DTbM) was proposed enabling both cross-sectional and volumetric measures from 3D T2-weighted turbo spin echo MR scans of the spinal cord at 3T. Eighty-two healthy subjects, 10 patients with amyotrophic lateral sclerosis, 10 with spinal muscular atrophy and 10 with spinal cord injuries were studied. DTbM was compared with active surface method (ASM), threshold-based method (TbM) and manual outlining (ground truth). Accuracy of segmentations was scored visually by a radiologist in cervical and thoracic cord regions. Accuracy was also quantified at the cervical and thoracic levels as well as at C2 vertebral level. To construct a cervical template from healthy subjects' images (n=59), a standardization pipeline was designed leading to well-centered straight spinal cord images and accurate probability tissue map. Visual scoring showed better performance for DTbM than for ASM. Mean Dice similarity coefficient (DSC) was 95.71% for DTbM and 90.78% for ASM at the cervical level and 94.27% for DTbM and 89.93% for ASM at the thoracic level. Finally, at C2 vertebral level, mean DSC was 97.98% for DTbM compared with 98.02% for TbM and 96.76% for ASM. DTbM showed similar accuracy compared with TbM, but with the advantage of limited manual interaction. A semi-automated segmentation method with limited manual intervention was introduced and validated on 3T images, enabling the construction of a cervical spinal cord template.

  20. Software SCMS re-engineering for a objected oriented language (JAVA) for use in construction of segmented phantoms

    International Nuclear Information System (INIS)

    Possani, Rafael Guedes

    2012-01-01

    Recent treatment planning systems depend strongly on CT images and the tendency is that the internal dosimetry procedures in nuclear medicine therapy be also based on images, such as magnetic resonance imaging (MRI) and computed tomography (CT), to extract anatomical and histological information, as well as, functional imaging or activities map as PET and SPECT. This information associated with a radiation transport simulation software is used to estimate internal dose in patients undergoing treatment in nuclear medicine. This work aims to re-engineer the software SCMS, which is an interface software between the Monte Carlo code MCNP, and the medical images, that carry information from the patient in treatment. In other words, the necessary information contained in the images are interpreted and presented in a specific format to the Monte Carlo MCNP code to perform the simulation of radiation transport. Therefore, the user does not need to understand the complex process of inputting data on MCNP, as the SCMS is responsible for automatically constructing anatomical data from the patient, as well as the radioactive source data. The SCMS was originally developed in Fortran-77. In this work it was rewritten in an object-oriented language (JAVA). New features and data options have also been incorporated into the software. Thus, the new software has a number of improvements, such as intuitive GUI and a menu for the selection of the energy spectra correspondent to a specific radioisotope stored in a XML data bank. The new version also supports new materials and the user can specify an image region of interest for the calculation of absorbed dose. (author)

  1. Comparison of the Resistance to Bending Forces of the 4.5 LCP Plate-rod Construct and of 4.5 LCP Alone Applied to Segmental Femoral Defects in Miniature Pigs

    Directory of Open Access Journals (Sweden)

    Lucie Urbanová

    2010-01-01

    Full Text Available The study deals with the determination of mechanical properties, namely resistance to bending forces, of flexible buttress osteosynthesis using two different bone-implant constructs stabilizing experimental segmental femoral bone defects (segmental ostectomy in a miniature pig ex vivo model using 4.5 mm titanium LCP and a 3 mm intramedullary pin (“plate and rod” construct (PR-LCP, versus the 4.5 mm titanium LCP alone (A-LCP. The “plate and rod” fixation (PR-LCP of the segmental femoral defect is significantly more resistant (p in vivo experiments in the miniature pig to investigate bone defect healing after transplantation of mesenchymal stem cells in combination with biocompatible scaffolds.

  2. Active Segmentation.

    Science.gov (United States)

    Mishra, Ajay; Aloimonos, Yiannis

    2009-01-01

    The human visual system observes and understands a scene/image by making a series of fixations. Every fixation point lies inside a particular region of arbitrary shape and size in the scene which can either be an object or just a part of it. We define as a basic segmentation problem the task of segmenting that region containing the fixation point. Segmenting the region containing the fixation is equivalent to finding the enclosing contour- a connected set of boundary edge fragments in the edge map of the scene - around the fixation. This enclosing contour should be a depth boundary.We present here a novel algorithm that finds this bounding contour and achieves the segmentation of one object, given the fixation. The proposed segmentation framework combines monocular cues (color/intensity/texture) with stereo and/or motion, in a cue independent manner. The semantic robots of the immediate future will be able to use this algorithm to automatically find objects in any environment. The capability of automatically segmenting objects in their visual field can bring the visual processing to the next level. Our approach is different from current approaches. While existing work attempts to segment the whole scene at once into many areas, we segment only one image region, specifically the one containing the fixation point. Experiments with real imagery collected by our active robot and from the known databases 1 demonstrate the promise of the approach.

  3. Segmentation: Identification of consumer segments

    DEFF Research Database (Denmark)

    Høg, Esben

    2005-01-01

    It is very common to categorise people, especially in the advertising business. Also traditional marketing theory has taken in consumer segments as a favorite topic. Segmentation is closely related to the broader concept of classification. From a historical point of view, classification has its...... origin in other sciences as for example biology, anthropology etc. From an economic point of view, it is called segmentation when specific scientific techniques are used to classify consumers to different characteristic groupings. What is the purpose of segmentation? For example, to be able to obtain...... a basic understanding of grouping people. Advertising agencies may use segmentation totarget advertisements, while food companies may usesegmentation to develop products to various groups of consumers. MAPP has for example investigated the positioning of fish in relation to other food products...

  4. Segmental Vitiligo.

    Science.gov (United States)

    van Geel, Nanja; Speeckaert, Reinhart

    2017-04-01

    Segmental vitiligo is characterized by its early onset, rapid stabilization, and unilateral distribution. Recent evidence suggests that segmental and nonsegmental vitiligo could represent variants of the same disease spectrum. Observational studies with respect to its distribution pattern point to a possible role of cutaneous mosaicism, whereas the original stated dermatomal distribution seems to be a misnomer. Although the exact pathogenic mechanism behind the melanocyte destruction is still unknown, increasing evidence has been published on the autoimmune/inflammatory theory of segmental vitiligo. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Rediscovering market segmentation.

    Science.gov (United States)

    Yankelovich, Daniel; Meer, David

    2006-02-01

    In 1964, Daniel Yankelovich introduced in the pages of HBR the concept of nondemographic segmentation, by which he meant the classification of consumers according to criteria other than age, residence, income, and such. The predictive power of marketing studies based on demographics was no longer strong enough to serve as a basis for marketing strategy, he argued. Buying patterns had become far better guides to consumers' future purchases. In addition, properly constructed nondemographic segmentations could help companies determine which products to develop, which distribution channels to sell them in, how much to charge for them, and how to advertise them. But more than 40 years later, nondemographic segmentation has become just as unenlightening as demographic segmentation had been. Today, the technique is used almost exclusively to fulfill the needs of advertising, which it serves mainly by populating commercials with characters that viewers can identify with. It is true that psychographic types like "High-Tech Harry" and "Joe Six-Pack" may capture some truth about real people's lifestyles, attitudes, self-image, and aspirations. But they are no better than demographics at predicting purchase behavior. Thus they give corporate decision makers very little idea of how to keep customers or capture new ones. Now, Daniel Yankelovich returns to these pages, with consultant David Meer, to argue the case for a broad view of nondemographic segmentation. They describe the elements of a smart segmentation strategy, explaining how segmentations meant to strengthen brand identity differ from those capable of telling a company which markets it should enter and what goods to make. And they introduce their "gravity of decision spectrum", a tool that focuses on the form of consumer behavior that should be of the greatest interest to marketers--the importance that consumers place on a product or product category.

  6. Multiple Segmentation of Image Stacks

    DEFF Research Database (Denmark)

    Smets, Jonathan; Jaeger, Manfred

    2014-01-01

    We propose a method for the simultaneous construction of multiple image segmentations by combining a recently proposed “convolution of mixtures of Gaussians” model with a multi-layer hidden Markov random field structure. The resulting method constructs for a single image several, alternative...

  7. Mixed segmentation

    DEFF Research Database (Denmark)

    Hansen, Allan Grutt; Bonde, Anders; Aagaard, Morten

    content analysis and audience segmentation in a single-source perspective. The aim is to explain and understand target groups in relation to, on the one hand, emotional response to commercials or other forms of audio-visual communication and, on the other hand, living preferences and personality traits...

  8. Local constructions of gender-based violence amongst IDPs in northern Uganda: analysis of archival data collected using a gender- and age-segmented participatory ranking methodology.

    Science.gov (United States)

    Ager, Alastair; Bancroft, Carolyn; Berger, Elizabeth; Stark, Lindsay

    2018-01-01

    Gender-based violence (GBV) is a significant problem in conflict-affected settings. Understanding local constructions of such violence is crucial to developing preventive and responsive interventions to address this issue. This study reports on a secondary analysis of archived data collected as part of formative qualitative work - using a group participatory ranking methodology (PRM) - informing research on the prevalence of GBV amongst IDPs in northern Uganda in 2006. Sixty-four PRM group discussions were held with women, with men, with girls (aged 14 to 18 years), and with boys (aged 14 to 18 years) selected on a randomized basis across four internally displaced persons (IDP) camps in Lira District. Discussions elicited problems facing women in the camps, and - through structured participatory methods - consensus ranking of their importance and narrative accounts explaining these judgments. Amongst forms of GBV faced by women, rape was ranked as the greatest concern amongst participants (with a mean problem rank of 3.4), followed by marital rape (mean problem rank of 4.5) and intimate partner violence (mean problem rank of 4.9). Girls ranked all forms of GBV as higher priority concerns than other participants. Discussions indicated that these forms of GBV were generally considered normalized within the camp. Gender roles and power, economic deprivation, and physical and social characteristics of the camp setting emerged as key explanatory factors in accounts of GBV prevalence, although these played out in different ways with respect to differing forms of violence. All groups acknowledged GBV to represent a significant threat - among other major concerns such as transportation, water, shelter, food and security - for women residing in the camps. Given evidence of the significantly higher risk in the camp of intimate partner violence and marital rape, the relative prominence of the issue of rape in all rankings suggests normalization of violence within the home

  9. Scintillation counter, segmented shield

    International Nuclear Information System (INIS)

    Olson, R.E.; Thumim, A.D.

    1975-01-01

    A scintillation counter, particularly for counting gamma ray photons, includes a massive lead radiation shield surrounding a sample-receiving zone. The shield is disassembleable into a plurality of segments to allow facile installation and removal of a photomultiplier tube assembly, the segments being so constructed as to prevent straight-line access of external radiation through the shield into radiation-responsive areas. Provisions are made for accurately aligning the photomultiplier tube with respect to one or more sample-transmitting bores extending through the shield to the sample receiving zone. A sample elevator, used in transporting samples into the zone, is designed to provide a maximum gamma-receiving aspect to maximize the gamma detecting efficiency. (U.S.)

  10. Brookhaven segment interconnect

    International Nuclear Information System (INIS)

    Morse, W.M.; Benenson, G.; Leipuner, L.B.

    1983-01-01

    We have performed a high energy physics experiment using a multisegment Brookhaven FASTBUS system. The system was composed of three crate segments and two cable segments. We discuss the segment interconnect module which permits communication between the various segments

  11. Efficient Algorithms for Segmentation of Item-Set Time Series

    Science.gov (United States)

    Chundi, Parvathi; Rosenkrantz, Daniel J.

    We propose a special type of time series, which we call an item-set time series, to facilitate the temporal analysis of software version histories, email logs, stock market data, etc. In an item-set time series, each observed data value is a set of discrete items. We formalize the concept of an item-set time series and present efficient algorithms for segmenting a given item-set time series. Segmentation of a time series partitions the time series into a sequence of segments where each segment is constructed by combining consecutive time points of the time series. Each segment is associated with an item set that is computed from the item sets of the time points in that segment, using a function which we call a measure function. We then define a concept called the segment difference, which measures the difference between the item set of a segment and the item sets of the time points in that segment. The segment difference values are required to construct an optimal segmentation of the time series. We describe novel and efficient algorithms to compute segment difference values for each of the measure functions described in the paper. We outline a dynamic programming based scheme to construct an optimal segmentation of the given item-set time series. We use the item-set time series segmentation techniques to analyze the temporal content of three different data sets—Enron email, stock market data, and a synthetic data set. The experimental results show that an optimal segmentation of item-set time series data captures much more temporal content than a segmentation constructed based on the number of time points in each segment, without examining the item set data at the time points, and can be used to analyze different types of temporal data.

  12. Segmented trapped vortex cavity

    Science.gov (United States)

    Grammel, Jr., Leonard Paul (Inventor); Pennekamp, David Lance (Inventor); Winslow, Jr., Ralph Henry (Inventor)

    2010-01-01

    An annular trapped vortex cavity assembly segment comprising includes a cavity forward wall, a cavity aft wall, and a cavity radially outer wall there between defining a cavity segment therein. A cavity opening extends between the forward and aft walls at a radially inner end of the assembly segment. Radially spaced apart pluralities of air injection first and second holes extend through the forward and aft walls respectively. The segment may include first and second expansion joint features at distal first and second ends respectively of the segment. The segment may include a forward subcomponent including the cavity forward wall attached to an aft subcomponent including the cavity aft wall. The forward and aft subcomponents include forward and aft portions of the cavity radially outer wall respectively. A ring of the segments may be circumferentially disposed about an axis to form an annular segmented vortex cavity assembly.

  13. Pavement management segment consolidation

    Science.gov (United States)

    1998-01-01

    Dividing roads into "homogeneous" segments has been a major problem for all areas of highway engineering. SDDOT uses Deighton Associates Limited software, dTIMS, to analyze life-cycle costs for various rehabilitation strategies on each segment of roa...

  14. Speaker segmentation and clustering

    OpenAIRE

    Kotti, M; Moschou, V; Kotropoulos, C

    2008-01-01

    07.08.13 KB. Ok to add the accepted version to Spiral, Elsevier says ok whlile mandate not enforced. This survey focuses on two challenging speech processing topics, namely: speaker segmentation and speaker clustering. Speaker segmentation aims at finding speaker change points in an audio stream, whereas speaker clustering aims at grouping speech segments based on speaker characteristics. Model-based, metric-based, and hybrid speaker segmentation algorithms are reviewed. Concerning speaker...

  15. Spinal segmental dysgenesis

    Directory of Open Access Journals (Sweden)

    N Mahomed

    2009-06-01

    Full Text Available Spinal segmental dysgenesis is a rare congenital spinal abnormality , seen in neonates and infants in which a segment of the spine and spinal cord fails to develop normally . The condition is segmental with normal vertebrae above and below the malformation. This condition is commonly associated with various abnormalities that affect the heart, genitourinary, gastrointestinal tract and skeletal system. We report two cases of spinal segmental dysgenesis and the associated abnormalities.

  16. Automatic Melody Segmentation

    NARCIS (Netherlands)

    Rodríguez López, Marcelo

    2016-01-01

    The work presented in this dissertation investigates music segmentation. In the field of Musicology, segmentation refers to a score analysis technique, whereby notated pieces or passages of these pieces are divided into “units” referred to as sections, periods, phrases, and so on. Segmentation

  17. Reflection symmetry-integrated image segmentation.

    Science.gov (United States)

    Sun, Yu; Bhanu, Bir

    2012-09-01

    This paper presents a new symmetry-integrated region-based image segmentation method. The method is developed to obtain improved image segmentation by exploiting image symmetry. It is realized by constructing a symmetry token that can be flexibly embedded into segmentation cues. Interesting points are initially extracted from an image by the SIFT operator and they are further refined for detecting the global bilateral symmetry. A symmetry affinity matrix is then computed using the symmetry axis and it is used explicitly as a constraint in a region growing algorithm in order to refine the symmetry of the segmented regions. A multi-objective genetic search finds the segmentation result with the highest performance for both segmentation and symmetry, which is close to the global optimum. The method has been investigated experimentally in challenging natural images and images containing man-made objects. It is shown that the proposed method outperforms current segmentation methods both with and without exploiting symmetry. A thorough experimental analysis indicates that symmetry plays an important role as a segmentation cue, in conjunction with other attributes like color and texture.

  18. Segmentation, advertising and prices

    NARCIS (Netherlands)

    Galeotti, Andrea; Moraga González, José

    This paper explores the implications of market segmentation on firm competitiveness. In contrast to earlier work, here market segmentation is minimal in the sense that it is based on consumer attributes that are completely unrelated to tastes. We show that when the market is comprised by two

  19. Sipunculans and segmentation

    DEFF Research Database (Denmark)

    Wanninger, Andreas; Kristof, Alen; Brinkmann, Nora

    2009-01-01

    mechanisms may act on the level of gene expression, cell proliferation, tissue differentiation and organ system formation in individual segments. Accordingly, in some polychaete annelids the first three pairs of segmental peripheral neurons arise synchronously, while the metameric commissures of the ventral...

  20. Pancreas and cyst segmentation

    Science.gov (United States)

    Dmitriev, Konstantin; Gutenko, Ievgeniia; Nadeem, Saad; Kaufman, Arie

    2016-03-01

    Accurate segmentation of abdominal organs from medical images is an essential part of surgical planning and computer-aided disease diagnosis. Many existing algorithms are specialized for the segmentation of healthy organs. Cystic pancreas segmentation is especially challenging due to its low contrast boundaries, variability in shape, location and the stage of the pancreatic cancer. We present a semi-automatic segmentation algorithm for pancreata with cysts. In contrast to existing automatic segmentation approaches for healthy pancreas segmentation which are amenable to atlas/statistical shape approaches, a pancreas with cysts can have even higher variability with respect to the shape of the pancreas due to the size and shape of the cyst(s). Hence, fine results are better attained with semi-automatic steerable approaches. We use a novel combination of random walker and region growing approaches to delineate the boundaries of the pancreas and cysts with respective best Dice coefficients of 85.1% and 86.7%, and respective best volumetric overlap errors of 26.0% and 23.5%. Results show that the proposed algorithm for pancreas and pancreatic cyst segmentation is accurate and stable.

  1. Lay-out and construction of a pressure vessel built-up of cast steel segments for a pebble-bed high temperature reactor with a thermal power of 3000 MW

    International Nuclear Information System (INIS)

    Voigt, J.

    1978-03-01

    The prestressed cast vessel is an alternative to the prestressed concrete vessel for big high temperature reactors. In this report different cast steel vessel concepts for an HTR for generation of current with 3000 MW(th) are compared concerning their realization and economy. The most favourable variant serves as a base for the lay-out of the single vessel components as cast steel segments, bracing, cooling and outer sealing. Hereby the actual available possibilities of production and transport are considered. For the concept worked out possibilities of inspection and repair are suggested. A comparison of costs with adequate proposititons of the industry for a prestressed concrete and a cast iron pressure vessel investigates the economical competition. (orig.) [de

  2. Segmentation of consumer's markets and evaluation of market's segments

    OpenAIRE

    ŠVECOVÁ, Iveta

    2013-01-01

    The goal of this bachelor thesis was to explain a possibly segmentation of consumer´s markets for a chosen company, and to present a suitable goods offer, so it would be suitable to the needs of selected segments. The work is divided into theoretical and practical part. First part describes marketing, segmentation, segmentation of consumer's markets, consumer's market, market's segments a other terms. Second part describes an evaluation of questionnaire survey, discovering of market's segment...

  3. The Effects of Transition and War on the Construction of Some Segments of National Identity among Croats and Serbs (An Empirical Survey in the Former War Areas of Western and Eastern Slavonia

    Directory of Open Access Journals (Sweden)

    Dragutin Babić

    2005-09-01

    Full Text Available The author analyses the effects of transition and war on the formation of some segments of national identity among Croats and Serbs. The basis for the analysis was an empirical survey conducted in Western and Eastern Slavonia. The analysis included three groups of war migrants and victims of war – indigenous Croats, indigenous Serbs and immigrants. The survey was conducted between September and December 2004, in villages and towns of Western and Eastern Slavonia. It used a survey questionnaire with 48 closed-type questions. The survey took account of the following variables among respondents: sociospatial status, age, gender and level of education. The analysed variable: respondents’ sociospatial status, proved to be in correlation with the perception of some segments of national identity among Croats and Serbs. The results of the survey showed differences in the opinions and evaluations of respondents from Western and Eastern Slavonia. Indigenous Croats, more than indigenous Serbs, stressed the meaning and importance of religion (Catholicism in national identity. Indigenous Croats were more exclusive than indigenous Serbs as to the possibilities of full participation of former Communists in the Croat and Serb national communities. The responses of immigrants were more radical and exclusive in comparison with indigenous persons, and in this regard responses of immigrants in Western Slavonia (mostly ethnic Croats were more radical than responses of immigrants in Eastern Slavonia (mostly ethnic Serbs. Although they were somewhat laced with exclusive opinions on the possibilities of including various subidentities in the national identities of Croats and Serbs, the respondents’ answers indicate that in the post-war period, in former war areas, tolerance is also quite present, more noticeably within one’s own group than towards the other nationality.

  4. Innovations in nuclear concrete constructions

    International Nuclear Information System (INIS)

    Tatum, C.B.

    1983-01-01

    The technical requirements and scope of concrete work on nuclear projects present significant engineering and construction challenges. These demands represent the extremes in many areas of construction operations. In meeting these challenges, engineering and construction forces have developed several innovations which can be beneficially applied to other types of construction. Innovative approaches in the general categories of engineering scope, construction input to engineering, work planning, special methods and techniques, and satisfaction of quality assurance requirements are given in this paper. The transfer of this technology to other segments of the construction industry will improve overall performance by avoiding the problem areas encountered on nuclear projects

  5. Segmental tuberculosis verrucosa cutis

    Directory of Open Access Journals (Sweden)

    Hanumanthappa H

    1994-01-01

    Full Text Available A case of segmental Tuberculosis Verrucosa Cutis is reported in 10 year old boy. The condition was resembling the ascending lymphangitic type of sporotrichosis. The lesions cleared on treatment with INH 150 mg daily for 6 months.

  6. Chromosome condensation and segmentation

    International Nuclear Information System (INIS)

    Viegas-Pequignot, E.M.

    1981-01-01

    Some aspects of chromosome condensation in mammalians -humans especially- were studied by means of cytogenetic techniques of chromosome banding. Two further approaches were adopted: a study of normal condensation as early as prophase, and an analysis of chromosome segmentation induced by physical (temperature and γ-rays) or chemical agents (base analogues, antibiotics, ...) in order to show out the factors liable to affect condensation. Here 'segmentation' means an abnormal chromosome condensation appearing systematically and being reproducible. The study of normal condensation was made possible by the development of a technique based on cell synchronization by thymidine and giving prophasic and prometaphasic cells. Besides, the possibility of inducing R-banding segmentations on these cells by BrdU (5-bromodeoxyuridine) allowed a much finer analysis of karyotypes. Another technique was developed using 5-ACR (5-azacytidine), it allowed to induce a segmentation similar to the one obtained using BrdU and identify heterochromatic areas rich in G-C bases pairs [fr

  7. International EUREKA: Initialization Segment

    International Nuclear Information System (INIS)

    1982-02-01

    The Initialization Segment creates the starting description of the uranium market. The starting description includes the international boundaries of trade, the geologic provinces, resources, reserves, production, uranium demand forecasts, and existing market transactions. The Initialization Segment is designed to accept information of various degrees of detail, depending on what is known about each region. It must transform this information into a specific data structure required by the Market Segment of the model, filling in gaps in the information through a predetermined sequence of defaults and built in assumptions. A principal function of the Initialization Segment is to create diagnostic messages indicating any inconsistencies in data and explaining which assumptions were used to organize the data base. This permits the user to manipulate the data base until such time the user is satisfied that all the assumptions used are reasonable and that any inconsistencies are resolved in a satisfactory manner

  8. Fluence map segmentation

    International Nuclear Information System (INIS)

    Rosenwald, J.-C.

    2008-01-01

    The lecture addressed the following topics: 'Interpreting' the fluence map; The sequencer; Reasons for difference between desired and actual fluence map; Principle of 'Step and Shoot' segmentation; Large number of solutions for given fluence map; Optimizing 'step and shoot' segmentation; The interdigitation constraint; Main algorithms; Conclusions on segmentation algorithms (static mode); Optimizing intensity levels and monitor units; Sliding window sequencing; Synchronization to avoid the tongue-and-groove effect; Accounting for physical characteristics of MLC; Importance of corrections for leaf transmission and offset; Accounting for MLC mechanical constraints; The 'complexity' factor; Incorporating the sequencing into optimization algorithm; Data transfer to the treatment machine; Interface between R and V and accelerator; and Conclusions on fluence map segmentation (Segmentation is part of the overall inverse planning procedure; 'Step and Shoot' and 'Dynamic' options are available for most TPS (depending on accelerator model; The segmentation phase tends to come into the optimization loop; The physical characteristics of the MLC have a large influence on final dose distribution; The IMRT plans (MU and relative dose distribution) must be carefully validated). (P.A.)

  9. Gamifying Video Object Segmentation.

    Science.gov (United States)

    Spampinato, Concetto; Palazzo, Simone; Giordano, Daniela

    2017-10-01

    Video object segmentation can be considered as one of the most challenging computer vision problems. Indeed, so far, no existing solution is able to effectively deal with the peculiarities of real-world videos, especially in cases of articulated motion and object occlusions; limitations that appear more evident when we compare the performance of automated methods with the human one. However, manually segmenting objects in videos is largely impractical as it requires a lot of time and concentration. To address this problem, in this paper we propose an interactive video object segmentation method, which exploits, on one hand, the capability of humans to identify correctly objects in visual scenes, and on the other hand, the collective human brainpower to solve challenging and large-scale tasks. In particular, our method relies on a game with a purpose to collect human inputs on object locations, followed by an accurate segmentation phase achieved by optimizing an energy function encoding spatial and temporal constraints between object regions as well as human-provided location priors. Performance analysis carried out on complex video benchmarks, and exploiting data provided by over 60 users, demonstrated that our method shows a better trade-off between annotation times and segmentation accuracy than interactive video annotation and automated video object segmentation approaches.

  10. Strategic market segmentation

    Directory of Open Access Journals (Sweden)

    Maričić Branko R.

    2015-01-01

    Full Text Available Strategic planning of marketing activities is the basis of business success in modern business environment. Customers are not homogenous in their preferences and expectations. Formulating an adequate marketing strategy, focused on realization of company's strategic objectives, requires segmented approach to the market that appreciates differences in expectations and preferences of customers. One of significant activities in strategic planning of marketing activities is market segmentation. Strategic planning imposes a need to plan marketing activities according to strategically important segments on the long term basis. At the same time, there is a need to revise and adapt marketing activities on the short term basis. There are number of criteria based on which market segmentation is performed. The paper will consider effectiveness and efficiency of different market segmentation criteria based on empirical research of customer expectations and preferences. The analysis will include traditional criteria and criteria based on behavioral model. The research implications will be analyzed from the perspective of selection of the most adequate market segmentation criteria in strategic planning of marketing activities.

  11. Applications of magnetic resonance image segmentation in neurology

    Science.gov (United States)

    Heinonen, Tomi; Lahtinen, Antti J.; Dastidar, Prasun; Ryymin, Pertti; Laarne, Paeivi; Malmivuo, Jaakko; Laasonen, Erkki; Frey, Harry; Eskola, Hannu

    1999-05-01

    After the introduction of digital imagin devices in medicine computerized tissue recognition and classification have become important in research and clinical applications. Segmented data can be applied among numerous research fields including volumetric analysis of particular tissues and structures, construction of anatomical modes, 3D visualization, and multimodal visualization, hence making segmentation essential in modern image analysis. In this research project several PC based software were developed in order to segment medical images, to visualize raw and segmented images in 3D, and to produce EEG brain maps in which MR images and EEG signals were integrated. The software package was tested and validated in numerous clinical research projects in hospital environment.

  12. Utilising Tree-Based Ensemble Learning for Speaker Segmentation

    DEFF Research Database (Denmark)

    Abou-Zleikha, Mohamed; Tan, Zheng-Hua; Christensen, Mads Græsbøll

    2014-01-01

    In audio and speech processing, accurate detection of the changing points between multiple speakers in speech segments is an important stage for several applications such as speaker identification and tracking. Bayesian Information Criteria (BIC)-based approaches are the most traditionally used...... for a certain condition, the model becomes biased to the data used for training limiting the model’s generalisation ability. In this paper, we propose a BIC-based tuning-free approach for speaker segmentation through the use of ensemble-based learning. A forest of segmentation trees is constructed in which each...... tree is trained using a sampled version of the speech segment. During the tree construction process, a set of randomly selected points in the input sequence is examined as potential segmentation points. The point that yields the highest ΔBIC is chosen and the same process is repeated for the resultant...

  13. Segmented block copolymers with monodisperse aramide end-segments

    NARCIS (Netherlands)

    Araichimani, A.; Gaymans, R.J.

    2008-01-01

    Segmented block copolymers were synthesized using monodisperse diaramide (TT) as hard segments and PTMO with a molecular weight of 2 900 g · mol-1 as soft segments. The aramide: PTMO segment ratio was increased from 1:1 to 2:1 thereby changing the structure from a high molecular weight multi-block

  14. Scorpion image segmentation system

    Science.gov (United States)

    Joseph, E.; Aibinu, A. M.; Sadiq, B. A.; Bello Salau, H.; Salami, M. J. E.

    2013-12-01

    Death as a result of scorpion sting has been a major public health problem in developing countries. Despite the high rate of death as a result of scorpion sting, little report exists in literature of intelligent device and system for automatic detection of scorpion. This paper proposed a digital image processing approach based on the floresencing characteristics of Scorpion under Ultra-violet (UV) light for automatic detection and identification of scorpion. The acquired UV-based images undergo pre-processing to equalize uneven illumination and colour space channel separation. The extracted channels are then segmented into two non-overlapping classes. It has been observed that simple thresholding of the green channel of the acquired RGB UV-based image is sufficient for segmenting Scorpion from other background components in the acquired image. Two approaches to image segmentation have also been proposed in this work, namely, the simple average segmentation technique and K-means image segmentation. The proposed algorithm has been tested on over 40 UV scorpion images obtained from different part of the world and results obtained show an average accuracy of 97.7% in correctly classifying the pixel into two non-overlapping clusters. The proposed 1system will eliminate the problem associated with some of the existing manual approaches presently in use for scorpion detection.

  15. Optimal graph based segmentation using flow lines with application to airway wall segmentation

    DEFF Research Database (Denmark)

    Petersen, Jens; Nielsen, Mads; Lo, Pechin

    2011-01-01

    This paper introduces a novel optimal graph construction method that is applicable to multi-dimensional, multi-surface segmentation problems. Such problems are often solved by refining an initial coarse surface within the space given by graph columns. Conventional columns are not well suited for ...

  16. Optimal graph based segmentation using flow lines with application to airway wall segmentation

    DEFF Research Database (Denmark)

    Petersen, Jens; Nielsen, Mads; Lo, Pechin Chien Pau

    2011-01-01

    This paper introduces a novel optimal graph construction method that is applicable to multi-dimensional, multi-surface segmentation problems. Such problems are often solved by refining an initial coarse surface within the space given by graph columns. Conventional columns are not well suited...

  17. Effects of Degree of Segmentation and Learner Disposition on Multimedia Learning

    Science.gov (United States)

    Doolittle, Peter E.; Bryant, Lauren H.; Chittum, Jessica R.

    2015-01-01

    The construction of asynchronous learning environments often involves the creation of self-paced multimedia instructional episodes that provide the learner with control over the pacing of instruction (segmentation); however, does the amount of segmentation impact learning? This study explored the effects of the degree of segmentation on recall and…

  18. Segmentation of complex document

    Directory of Open Access Journals (Sweden)

    Souad Oudjemia

    2014-06-01

    Full Text Available In this paper we present a method for segmentation of documents image with complex structure. This technique based on GLCM (Grey Level Co-occurrence Matrix used to segment this type of document in three regions namely, 'graphics', 'background' and 'text'. Very briefly, this method is to divide the document image, in block size chosen after a series of tests and then applying the co-occurrence matrix to each block in order to extract five textural parameters which are energy, entropy, the sum entropy, difference entropy and standard deviation. These parameters are then used to classify the image into three regions using the k-means algorithm; the last step of segmentation is obtained by grouping connected pixels. Two performance measurements are performed for both graphics and text zones; we have obtained a classification rate of 98.3% and a Misclassification rate of 1.79%.

  19. Connecting textual segments

    DEFF Research Database (Denmark)

    Brügger, Niels

    2017-01-01

    history than just the years of the emergence of the web, the chapter traces the history of how segments of text have deliberately been connected to each other by the use of specific textual and media features, from clay tablets, manuscripts on parchment, and print, among others, to hyperlinks on stand......In “Connecting textual segments: A brief history of the web hyperlink” Niels Brügger investigates the history of one of the most fundamental features of the web: the hyperlink. Based on the argument that the web hyperlink is best understood if it is seen as another step in a much longer and broader...

  20. Segmentation in reading and film comprehension.

    Science.gov (United States)

    Zacks, Jeffrey M; Speer, Nicole K; Reynolds, Jeremy R

    2009-05-01

    When reading a story or watching a film, comprehenders construct a series of representations in order to understand the events depicted. Discourse comprehension theories and a recent theory of perceptual event segmentation both suggest that comprehenders monitor situational features such as characters' goals, to update these representations at natural boundaries in activity. However, the converging predictions of these theories had previously not been tested directly. Two studies provided evidence that changes in situational features such as characters, their locations, their interactions with objects, and their goals are related to the segmentation of events in both narrative texts and films. A 3rd study indicated that clauses with event boundaries are read more slowly than are other clauses and that changes in situational features partially mediate this relation. A final study suggested that the predictability of incoming information influences reading rate and possibly event segmentation. Taken together, these results suggest that processing situational changes during comprehension is an important determinant of how one segments ongoing activity into events and that this segmentation is related to the control of processing during reading. (c) 2009 APA, all rights reserved.

  1. Segmentation in cinema perception.

    Science.gov (United States)

    Carroll, J M; Bever, T G

    1976-03-12

    Viewers perceptually segment moving picture sequences into their cinematically defined units: excerpts that follow short film sequences are recognized faster when the excerpt originally came after a structural cinematic break (a cut or change in the action) than when it originally came before the break.

  2. Dictionary Based Image Segmentation

    DEFF Research Database (Denmark)

    Dahl, Anders Bjorholm; Dahl, Vedrana Andersen

    2015-01-01

    We propose a method for weakly supervised segmentation of natural images, which may contain both textured or non-textured regions. Our texture representation is based on a dictionary of image patches. To divide an image into separated regions with similar texture we use an implicit level sets...

  3. Unsupervised Image Segmentation

    Czech Academy of Sciences Publication Activity Database

    Haindl, Michal; Mikeš, Stanislav

    2014-01-01

    Roč. 36, č. 4 (2014), s. 23-23 R&D Projects: GA ČR(CZ) GA14-10911S Institutional support: RVO:67985556 Keywords : unsupervised image segmentation Subject RIV: BD - Theory of Information http://library.utia.cas.cz/separaty/2014/RO/haindl-0434412.pdf

  4. Metrics for image segmentation

    Science.gov (United States)

    Rees, Gareth; Greenway, Phil; Morray, Denise

    1998-07-01

    An important challenge in mapping image-processing techniques onto applications is the lack of quantitative performance measures. From a systems engineering perspective these are essential if system level requirements are to be decomposed into sub-system requirements which can be understood in terms of algorithm selection and performance optimization. Nowhere in computer vision is this more evident than in the area of image segmentation. This is a vigorous and innovative research activity, but even after nearly two decades of progress, it remains almost impossible to answer the question 'what would the performance of this segmentation algorithm be under these new conditions?' To begin to address this shortcoming, we have devised a well-principled metric for assessing the relative performance of two segmentation algorithms. This allows meaningful objective comparisons to be made between their outputs. It also estimates the absolute performance of an algorithm given ground truth. Our approach is an information theoretic one. In this paper, we describe the theory and motivation of our method, and present practical results obtained from a range of state of the art segmentation methods. We demonstrate that it is possible to measure the objective performance of these algorithms, and to use the information so gained to provide clues about how their performance might be improved.

  5. AISLE: an automatic volumetric segmentation method for the study of lung allometry.

    Science.gov (United States)

    Ren, Hongliang; Kazanzides, Peter

    2011-01-01

    We developed a fully automatic segmentation method for volumetric CT (computer tomography) datasets to support construction of a statistical atlas for the study of allometric laws of the lung. The proposed segmentation method, AISLE (Automated ITK-Snap based on Level-set), is based on the level-set implementation from an existing semi-automatic segmentation program, ITK-Snap. AISLE can segment the lung field without human interaction and provide intermediate graphical results as desired. The preliminary experimental results show that the proposed method can achieve accurate segmentation, in terms of volumetric overlap metric, by comparing with the ground-truth segmentation performed by a radiologist.

  6. Indigenous lunar construction materials

    Science.gov (United States)

    Rogers, Wayne P.; Sture, Stein

    1991-01-01

    The utilization of local resources for the construction and operation of a lunar base can significantly reduce the cost of transporting materials and supplies from Earth. The feasibility of processing lunar regolith to form construction materials and structural components is investigated. A preliminary review of potential processing methods such as sintering, hot-pressing, liquification, and cast basalt techniques, was completed. The processing method proposed is a variation on the cast basalt technique. It involves liquification of the regolith at 1200-1300 C, casting the liquid into a form, and controlled cooling. While the process temperature is higher than that for sintering or hot-pressing (1000-1100 C), this method is expected to yield a true engineering material with low variability in properties, high strength, and the potential to form large structural components. A scenario for this processing method was integrated with a design for a representative lunar base structure and potential construction techniques. The lunar shelter design is for a modular, segmented, pressurized, hemispherical dome which could serve as habitation and laboratory space. Based on this design, estimates of requirements for power, processing equipment, and construction equipment were made. This proposed combination of material processing method, structural design, and support requirements will help to establish the feasibility of lunar base construction using indigenous materials. Future work will refine the steps of the processing method. Specific areas where more information is needed are: furnace characteristics in vacuum; heat transfer during liquification; viscosity, pouring and forming behavior of molten regolith; design of high temperature forms; heat transfer during cooling; recrystallization of basalt; and refinement of estimates of elastic moduli, compressive and tensile strength, thermal expansion coefficient, thermal conductivity, and heat capacity. The preliminary

  7. Status of the segment interconnect, cable segment ancillary logic, and the cable segment hybrid driver projects

    International Nuclear Information System (INIS)

    Swoboda, C.; Barsotti, E.; Chappa, S.; Downing, R.; Goeransson, G.; Lensy, D.; Moore, G.; Rotolo, C.; Urish, J.

    1985-01-01

    The FASTBUS Segment Interconnect (SI) provides a communication path between two otherwise independent, asynchronous bus segments. In particular, the Segment Interconnect links a backplane crate segment to a cable segment. All standard FASTBUS address and data transactions can be passed through the SI or any number of SIs and segments in a path. Thus systems of arbitrary connection complexity can be formed, allowing simultaneous independent processing, yet still permitting devices associated with one segment to be accessed from others. The model S1 Segment Interconnect and the Cable Segment Ancillary Logic covered in this report comply with all the mandatory features stated in the FASTBUS specification document DOE/ER-0189. A block diagram of the SI is shown

  8. Market segmentation: Venezuelan ADRs

    Directory of Open Access Journals (Sweden)

    Urbi Garay

    2012-12-01

    Full Text Available The control on foreign exchange imposed by Venezuela in 2003 constitute a natural experiment that allows researchers to observe the effects of exchange controls on stock market segmentation. This paper provides empirical evidence that although the Venezuelan capital market as a whole was highly segmented before the controls were imposed, the shares in the firm CANTV were, through their American Depositary Receipts (ADRs, partially integrated with the global market. Following the imposition of the exchange controls this integration was lost. Research also documents the spectacular and apparently contradictory rise experienced by the Caracas Stock Exchange during the serious economic crisis of 2003. It is argued that, as it happened in Argentina in 2002, the rise in share prices occurred because the depreciation of the Bolívar in the parallel currency market increased the local price of the stocks that had associated ADRs, which were negotiated in dollars.

  9. Head segmentation in vertebrates

    OpenAIRE

    Kuratani, Shigeru; Schilling, Thomas

    2008-01-01

    Classic theories of vertebrate head segmentation clearly exemplify the idealistic nature of comparative embryology prior to the 20th century. Comparative embryology aimed at recognizing the basic, primary structure that is shared by all vertebrates, either as an archetype or an ancestral developmental pattern. Modern evolutionary developmental (Evo-Devo) studies are also based on comparison, and therefore have a tendency to reduce complex embryonic anatomy into overly simplified patterns. Her...

  10. Video segmentation using keywords

    Science.gov (United States)

    Ton-That, Vinh; Vong, Chi-Tai; Nguyen-Dao, Xuan-Truong; Tran, Minh-Triet

    2018-04-01

    At DAVIS-2016 Challenge, many state-of-art video segmentation methods achieve potential results, but they still much depend on annotated frames to distinguish between background and foreground. It takes a lot of time and efforts to create these frames exactly. In this paper, we introduce a method to segment objects from video based on keywords given by user. First, we use a real-time object detection system - YOLOv2 to identify regions containing objects that have labels match with the given keywords in the first frame. Then, for each region identified from the previous step, we use Pyramid Scene Parsing Network to assign each pixel as foreground or background. These frames can be used as input frames for Object Flow algorithm to perform segmentation on entire video. We conduct experiments on a subset of DAVIS-2016 dataset in half the size of its original size, which shows that our method can handle many popular classes in PASCAL VOC 2012 dataset with acceptable accuracy, about 75.03%. We suggest widely testing by combining other methods to improve this result in the future.

  11. Constructed Wetlands

    Science.gov (United States)

    these systems can improve water quality, engineers and scientists construct systems that replicate the functions of natural wetlands. Constructed wetlands are treatment systems that use natural processes

  12. Market segmentation in behavioral perspective.

    OpenAIRE

    Wells, V.K.; Chang, S.W.; Oliveira-Castro, J.M.; Pallister, J.

    2010-01-01

    A segmentation approach is presented using both traditional demographic segmentation bases (age, social class/occupation, and working status) and a segmentation by benefits sought. The benefits sought in this case are utilitarian and informational reinforcement, variables developed from the Behavioral Perspective Model (BPM). Using data from 1,847 consumers and from a total of 76,682 individual purchases, brand choice and price and reinforcement responsiveness were assessed for each segment a...

  13. Tissues segmentation based on multi spectral medical images

    Science.gov (United States)

    Li, Ya; Wang, Ying

    2017-11-01

    Each band image contains the most obvious tissue feature according to the optical characteristics of different tissues in different specific bands for multispectral medical images. In this paper, the tissues were segmented by their spectral information at each multispectral medical images. Four Local Binary Patter descriptors were constructed to extract blood vessels based on the gray difference between the blood vessels and their neighbors. The segmented tissue in each band image was merged to a clear image.

  14. Segmenting the Adult Education Market.

    Science.gov (United States)

    Aurand, Tim

    1994-01-01

    Describes market segmentation and how the principles of segmentation can be applied to the adult education market. Indicates that applying segmentation techniques to adult education programs results in programs that are educationally and financially satisfying and serve an appropriate population. (JOW)

  15. Market Segmentation for Information Services.

    Science.gov (United States)

    Halperin, Michael

    1981-01-01

    Discusses the advantages and limitations of market segmentation as strategy for the marketing of information services made available by nonprofit organizations, particularly libraries. Market segmentation is defined, a market grid for libraries is described, and the segmentation of information services is outlined. A 16-item reference list is…

  16. Segmentation hyperspectrale de forets tropicales par arbres de partition binaires

    OpenAIRE

    Tochon, Guillaume; Feret, J.B.; Valero, Silvia; Martin, R.E.; Tupayachi, R.; Chanussot, Jocelyn; Salembier Clairon, Philippe Jean; Asner, G.P.

    2013-01-01

    La segmentation d’images de forêts tropicales est un outil important pour faciliter le travail des écologues. Dans ce papier, nous proposons une nouvelle méthode de segmentation pour les images hyperspectrales, basée sur la construction d’un arbre de partition binaire (APB). Nous introduisons tout d’abord une étape de prétraitement combinant une analyse en composantes principales et la définition de cartes de pré-segmentation, afin de réduire spatialement et spectralement le volume de données...

  17. Continuously live image processor for drift chamber track segment triggering

    International Nuclear Information System (INIS)

    Berenyi, A.; Chen, H.K.; Dao, K.

    1999-01-01

    The first portion of the BaBar experiment Level 1 Drift Chamber Trigger pipeline is the Track Segment Finder (TSF). Using a novel method incorporating both occupancy and drift-time information, the TSF system continually searches for segments in the supercells of the full 7104-wire Drift Chamber hit image at 3.7 MHz. The TSF was constructed to operate in a potentially high beam-background environment while achieving high segment-finding efficiency, deadtime-free operation, a spatial resolution of 5 simulated physics events

  18. The semiotics of medical image Segmentation.

    Science.gov (United States)

    Baxter, John S H; Gibson, Eli; Eagleson, Roy; Peters, Terry M

    2018-02-01

    As the interaction between clinicians and computational processes increases in complexity, more nuanced mechanisms are required to describe how their communication is mediated. Medical image segmentation in particular affords a large number of distinct loci for interaction which can act on a deep, knowledge-driven level which complicates the naive interpretation of the computer as a symbol processing machine. Using the perspective of the computer as dialogue partner, we can motivate the semiotic understanding of medical image segmentation. Taking advantage of Peircean semiotic traditions and new philosophical inquiry into the structure and quality of metaphors, we can construct a unified framework for the interpretation of medical image segmentation as a sign exchange in which each sign acts as an interface metaphor. This allows for a notion of finite semiosis, described through a schematic medium, that can rigorously describe how clinicians and computers interpret the signs mediating their interaction. Altogether, this framework provides a unified approach to the understanding and development of medical image segmentation interfaces. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Albedo estimation for scene segmentation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C H; Rosenfeld, A

    1983-03-01

    Standard methods of image segmentation do not take into account the three-dimensional nature of the underlying scene. For example, histogram-based segmentation tacitly assumes that the image intensity is piecewise constant, and this is not true when the scene contains curved surfaces. This paper introduces a method of taking 3d information into account in the segmentation process. The image intensities are adjusted to compensate for the effects of estimated surface orientation; the adjusted intensities can be regarded as reflectivity estimates. When histogram-based segmentation is applied to these new values, the image is segmented into parts corresponding to surfaces of constant reflectivity in the scene. 7 references.

  20. Construction management

    CERN Document Server

    Pellicer, Eugenio; Teixeira, José C; Moura, Helder P; Catalá, Joaquín

    2014-01-01

    The management of construction projects is a wide ranging and challenging discipline in an increasingly international industry, facing continual challenges and demands for improvements in safety, in quality and cost control, and in the avoidance of contractual disputes. Construction Management grew out of a Leonardo da Vinci project to develop a series of Common Learning Outcomes for European Managers in Construction. Financed by the European Union, the project aimed to develop a library of basic materials for developing construction management skills for use in a pan-European context. Focused exclusively on the management of the construction phase of a building project from the contractor's point of view, Construction Management covers the complete range of topics of which mastery is required by the construction management professional for the effective delivery of new construction projects. With the continued internationalisation of the construction industry, Construction Management will be required rea...

  1. FRAMEWORK FOR COMPARING SEGMENTATION ALGORITHMS

    Directory of Open Access Journals (Sweden)

    G. Sithole

    2015-05-01

    Full Text Available The notion of a ‘Best’ segmentation does not exist. A segmentation algorithm is chosen based on the features it yields, the properties of the segments (point sets it generates, and the complexity of its algorithm. The segmentation is then assessed based on a variety of metrics such as homogeneity, heterogeneity, fragmentation, etc. Even after an algorithm is chosen its performance is still uncertain because the landscape/scenarios represented in a point cloud have a strong influence on the eventual segmentation. Thus selecting an appropriate segmentation algorithm is a process of trial and error. Automating the selection of segmentation algorithms and their parameters first requires methods to evaluate segmentations. Three common approaches for evaluating segmentation algorithms are ‘goodness methods’, ‘discrepancy methods’ and ‘benchmarks’. Benchmarks are considered the most comprehensive method of evaluation. This paper shortcomings in current benchmark methods are identified and a framework is proposed that permits both a visual and numerical evaluation of segmentations for different algorithms, algorithm parameters and evaluation metrics. The concept of the framework is demonstrated on a real point cloud. Current results are promising and suggest that it can be used to predict the performance of segmentation algorithms.

  2. Graph run-length matrices for histopathological image segmentation.

    Science.gov (United States)

    Tosun, Akif Burak; Gunduz-Demir, Cigdem

    2011-03-01

    The histopathological examination of tissue specimens is essential for cancer diagnosis and grading. However, this examination is subject to a considerable amount of observer variability as it mainly relies on visual interpretation of pathologists. To alleviate this problem, it is very important to develop computational quantitative tools, for which image segmentation constitutes the core step. In this paper, we introduce an effective and robust algorithm for the segmentation of histopathological tissue images. This algorithm incorporates the background knowledge of the tissue organization into segmentation. For this purpose, it quantifies spatial relations of cytological tissue components by constructing a graph and uses this graph to define new texture features for image segmentation. This new texture definition makes use of the idea of gray-level run-length matrices. However, it considers the runs of cytological components on a graph to form a matrix, instead of considering the runs of pixel intensities. Working with colon tissue images, our experiments demonstrate that the texture features extracted from "graph run-length matrices" lead to high segmentation accuracies, also providing a reasonable number of segmented regions. Compared with four other segmentation algorithms, the results show that the proposed algorithm is more effective in histopathological image segmentation.

  3. Electrocardiogram ST-Segment Morphology Delineation Method Using Orthogonal Transformations.

    Directory of Open Access Journals (Sweden)

    Miha Amon

    Full Text Available Differentiation between ischaemic and non-ischaemic transient ST segment events of long term ambulatory electrocardiograms is a persisting weakness in present ischaemia detection systems. Traditional ST segment level measuring is not a sufficiently precise technique due to the single point of measurement and severe noise which is often present. We developed a robust noise resistant orthogonal-transformation based delineation method, which allows tracing the shape of transient ST segment morphology changes from the entire ST segment in terms of diagnostic and morphologic feature-vector time series, and also allows further analysis. For these purposes, we developed a new Legendre Polynomials based Transformation (LPT of ST segment. Its basis functions have similar shapes to typical transient changes of ST segment morphology categories during myocardial ischaemia (level, slope and scooping, thus providing direct insight into the types of time domain morphology changes through the LPT feature-vector space. We also generated new Karhunen and Lo ève Transformation (KLT ST segment basis functions using a robust covariance matrix constructed from the ST segment pattern vectors derived from the Long Term ST Database (LTST DB. As for the delineation of significant transient ischaemic and non-ischaemic ST segment episodes, we present a study on the representation of transient ST segment morphology categories, and an evaluation study on the classification power of the KLT- and LPT-based feature vectors to classify between ischaemic and non-ischaemic ST segment episodes of the LTST DB. Classification accuracy using the KLT and LPT feature vectors was 90% and 82%, respectively, when using the k-Nearest Neighbors (k = 3 classifier and 10-fold cross-validation. New sets of feature-vector time series for both transformations were derived for the records of the LTST DB which is freely available on the PhysioNet website and were contributed to the LTST DB. The

  4. Managing Media: Segmenting Media Through Consumer Expectancies

    Directory of Open Access Journals (Sweden)

    Matt Eastin

    2014-04-01

    Full Text Available It has long been understood that consumers are motivated to media differently. However, given the lack of comparative model analysis, this assumption is without empirical validation, and thus, the orientation of segmentation from a media management perspective is without motivational grounds. Thus, evolving the literature on media consumption, the current study develops and compares models of media segmentation within the context of use. From this study, six models of media expectancies were constructed so that motivational differences between media (i.e., local and national newspapers, network and cable television, radio, and Internet could be observed. Utilizing higher order statistical analyses the data indicates differences across a model comparison approach for media motivations. Furthermore, these differences vary across numerous demographic factors. Results afford theoretical advancement within the literature of consumer media consumption as well as provide media planners’ insight into consumer choices.

  5. Optimally segmented magnetic structures

    DEFF Research Database (Denmark)

    Insinga, Andrea Roberto; Bahl, Christian; Bjørk, Rasmus

    We present a semi-analytical algorithm for magnet design problems, which calculates the optimal way to subdivide a given design region into uniformly magnetized segments.The availability of powerful rare-earth magnetic materials such as Nd-Fe-B has broadened the range of applications of permanent...... is not available.We will illustrate the results for magnet design problems from different areas, such as electric motors/generators (as the example in the picture), beam focusing for particle accelerators and magnetic refrigeration devices.......We present a semi-analytical algorithm for magnet design problems, which calculates the optimal way to subdivide a given design region into uniformly magnetized segments.The availability of powerful rare-earth magnetic materials such as Nd-Fe-B has broadened the range of applications of permanent...... magnets[1][2]. However, the powerful rare-earth magnets are generally expensive, so both the scientific and industrial communities have devoted a lot of effort into developing suitable design methods. Even so, many magnet optimization algorithms either are based on heuristic approaches[3...

  6. Development of a Novel Segmental Bone Defect Construct

    Science.gov (United States)

    2016-10-01

    polyampholyte polymers.15–17 This resistance to nonspecific protein adsorption has been demonstrated in biosens- ing, drug delivery , and tissue engineering...the nonspecific protein adsorption to hydrogels with different TMA:CAA:SA ratios at cross-linker densities of (a) 13, (b) 23, and (c) 43. ARTICLE ...calcium phosphate mineral referred to as hydroxyapatite, collagen, and other proteins which hold the first two components together. Many researchers

  7. Development of a Novel Segmental Bone Defect Construct

    Science.gov (United States)

    2017-10-01

    synthetic clay laponite XLG by 89 changing the laponite concentration (composition dependence) or the density of the polyethylene 90 glycol with N... clay laponite XLG that showed promise as a tissue engineering scaffold 202 due to its controlled release profiles, good mechanical properties, and...During the 377 optimization of this approach, Ladika et al. focused on finding a polymer solution with similar 378 viscosity to the industry standard

  8. Segmentation of the Infant Food Market

    OpenAIRE

    Hrůzová, Daniela

    2015-01-01

    The theoretical part covers general market segmentation, namely the marketing importance of differences among consumers, the essence of market segmentation, its main conditions and the process of segmentation, which consists of four consecutive phases - defining the market, determining important criteria, uncovering segments and developing segment profiles. The segmentation criteria, segmentation approaches, methods and techniques for the process of market segmentation are also described in t...

  9. Phasing multi-segment undulators

    International Nuclear Information System (INIS)

    Chavanne, J.; Elleaume, P.; Vaerenbergh, P. Van

    1996-01-01

    An important issue in the manufacture of multi-segment undulators as a source of synchrotron radiation or as a free-electron laser (FEL) is the phasing between successive segments. The state of the art is briefly reviewed, after which a novel pure permanent magnet phasing section that is passive and does not require any current is presented. The phasing section allows the introduction of a 6 mm longitudinal gap between each segment, resulting in complete mechanical independence and reduced magnetic interaction between segments. The tolerance of the longitudinal positioning of one segment with respect to the next is found to be 2.8 times lower than that of conventional phasing. The spectrum at all gaps and useful harmonics is almost unchanged when compared with a single-segment undulator of the same total length. (au) 3 refs

  10. Electrochemical construction

    Science.gov (United States)

    Einstein, Harry; Grimes, Patrick G.

    1983-08-23

    An electrochemical cell construction features a novel co-extruded plastic electrode in an interleaved construction with a novel integral separator-spacer. Also featured is a leak and impact resistant construction for preventing the spill of corrosive materials in the event of rupture.

  11. Usability Constructs

    DEFF Research Database (Denmark)

    Hertzum, Morten; Clemmesen, Torkil; Hornbæk, Kasper Anders Søren

    2007-01-01

    Whereas research on usability predominantly employs universal definitions of the aspects that comprise usability, people experience their use of information systems through personal constructs. Based on 48 repertory-grid interviews, this study investigates how such personal constructs are affected...... use of constructs traditionally associated with usability (e.g., easy-to-use, intuitive, and liked). Further analysis of the data is ongoing...

  12. The LOFT Ground Segment

    DEFF Research Database (Denmark)

    Bozzo, E.; Antonelli, A.; Argan, A.

    2014-01-01

    targets per orbit (~90 minutes), providing roughly ~80 GB of proprietary data per day (the proprietary period will be 12 months). The WFM continuously monitors about 1/3 of the sky at a time and provides data for about ~100 sources a day, resulting in a total of ~20 GB of additional telemetry. The LOFT...... Burst alert System additionally identifies on-board bright impulsive events (e.g., Gamma-ray Bursts, GRBs) and broadcasts the corresponding position and trigger time to the ground using a dedicated system of ~15 VHF receivers. All WFM data are planned to be made public immediately. In this contribution...... we summarize the planned organization of the LOFT ground segment (GS), as established in the mission Yellow Book 1 . We describe the expected GS contributions from ESA and the LOFT consortium. A review is provided of the planned LOFT data products and the details of the data flow, archiving...

  13. Segmented heat exchanger

    Science.gov (United States)

    Baldwin, Darryl Dean; Willi, Martin Leo; Fiveland, Scott Byron; Timmons, Kristine Ann

    2010-12-14

    A segmented heat exchanger system for transferring heat energy from an exhaust fluid to a working fluid. The heat exchanger system may include a first heat exchanger for receiving incoming working fluid and the exhaust fluid. The working fluid and exhaust fluid may travel through at least a portion of the first heat exchanger in a parallel flow configuration. In addition, the heat exchanger system may include a second heat exchanger for receiving working fluid from the first heat exchanger and exhaust fluid from a third heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the second heat exchanger in a counter flow configuration. Furthermore, the heat exchanger system may include a third heat exchanger for receiving working fluid from the second heat exchanger and exhaust fluid from the first heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the third heat exchanger in a parallel flow configuration.

  14. International EUREKA: Market Segment

    International Nuclear Information System (INIS)

    1982-03-01

    The purpose of the Market Segment of the EUREKA model is to simultaneously project uranium market prices, uranium supply and purchasing activities. The regional demands are extrinsic. However, annual forward contracting activities to meet these demands as well as inventory requirements are calculated. The annual price forecast is based on relatively short term, forward balances between available supply and desired purchases. The forecasted prices and extrapolated price trends determine decisions related to exploration and development, new production operations, and the operation of existing capacity. Purchasing and inventory requirements are also adjusted based on anticipated prices. The calculation proceeds one year at a time. Conditions calculated at the end of one year become the starting conditions for the calculation in the subsequent year

  15. Probabilistic retinal vessel segmentation

    Science.gov (United States)

    Wu, Chang-Hua; Agam, Gady

    2007-03-01

    Optic fundus assessment is widely used for diagnosing vascular and non-vascular pathology. Inspection of the retinal vasculature may reveal hypertension, diabetes, arteriosclerosis, cardiovascular disease and stroke. Due to various imaging conditions retinal images may be degraded. Consequently, the enhancement of such images and vessels in them is an important task with direct clinical applications. We propose a novel technique for vessel enhancement in retinal images that is capable of enhancing vessel junctions in addition to linear vessel segments. This is an extension of vessel filters we have previously developed for vessel enhancement in thoracic CT scans. The proposed approach is based on probabilistic models which can discern vessels and junctions. Evaluation shows the proposed filter is better than several known techniques and is comparable to the state of the art when evaluated on a standard dataset. A ridge-based vessel tracking process is applied on the enhanced image to demonstrate the effectiveness of the enhancement filter.

  16. Segmented rail linear induction motor

    Science.gov (United States)

    Cowan, Jr., Maynard; Marder, Barry M.

    1996-01-01

    A segmented rail linear induction motor has a segmented rail consisting of a plurality of nonferrous electrically conductive segments aligned along a guideway. The motor further includes a carriage including at least one pair of opposed coils fastened to the carriage for moving the carriage. A power source applies an electric current to the coils to induce currents in the conductive surfaces to repel the coils from adjacent edges of the conductive surfaces.

  17. Segmentation-DrivenTomographic Reconstruction

    DEFF Research Database (Denmark)

    Kongskov, Rasmus Dalgas

    such that the segmentation subsequently can be carried out by use of a simple segmentation method, for instance just a thresholding method. We tested the advantages of going from a two-stage reconstruction method to a one stage segmentation-driven reconstruction method for the phase contrast tomography reconstruction......The tomographic reconstruction problem is concerned with creating a model of the interior of an object from some measured data, typically projections of the object. After reconstructing an object it is often desired to segment it, either automatically or manually. For computed tomography (CT...

  18. Automated medical image segmentation techniques

    Directory of Open Access Journals (Sweden)

    Sharma Neeraj

    2010-01-01

    Full Text Available Accurate segmentation of medical images is a key step in contouring during radiotherapy planning. Computed topography (CT and Magnetic resonance (MR imaging are the most widely used radiographic techniques in diagnosis, clinical studies and treatment planning. This review provides details of automated segmentation methods, specifically discussed in the context of CT and MR images. The motive is to discuss the problems encountered in segmentation of CT and MR images, and the relative merits and limitations of methods currently available for segmentation of medical images.

  19. ADVANCED CLUSTER BASED IMAGE SEGMENTATION

    Directory of Open Access Journals (Sweden)

    D. Kesavaraja

    2011-11-01

    Full Text Available This paper presents efficient and portable implementations of a useful image segmentation technique which makes use of the faster and a variant of the conventional connected components algorithm which we call parallel Components. In the Modern world majority of the doctors are need image segmentation as the service for various purposes and also they expect this system is run faster and secure. Usually Image segmentation Algorithms are not working faster. In spite of several ongoing researches in Conventional Segmentation and its Algorithms might not be able to run faster. So we propose a cluster computing environment for parallel image Segmentation to provide faster result. This paper is the real time implementation of Distributed Image Segmentation in Clustering of Nodes. We demonstrate the effectiveness and feasibility of our method on a set of Medical CT Scan Images. Our general framework is a single address space, distributed memory programming model. We use efficient techniques for distributing and coalescing data as well as efficient combinations of task and data parallelism. The image segmentation algorithm makes use of an efficient cluster process which uses a novel approach for parallel merging. Our experimental results are consistent with the theoretical analysis and practical results. It provides the faster execution time for segmentation, when compared with Conventional method. Our test data is different CT scan images from the Medical database. More efficient implementations of Image Segmentation will likely result in even faster execution times.

  20. A Finite Segment Method for Skewed Box Girder Analysis

    Directory of Open Access Journals (Sweden)

    Xingwei Xue

    2018-01-01

    Full Text Available A finite segment method is presented to analyze the mechanical behavior of skewed box girders. By modeling the top and bottom plates of the segments with skew plate beam element under an inclined coordinate system and the webs with normal plate beam element, a spatial elastic displacement model for skewed box girder is constructed, which can satisfy the compatibility condition at the corners of the cross section for box girders. The formulation of the finite segment is developed based on the variational principle. The major advantage of the proposed approach, in comparison with the finite element method, is that it can simplify a three-dimensional structure into a one-dimensional structure for structural analysis, which results in significant saving in computational times. At last, the accuracy and efficiency of the proposed finite segment method are verified by a model test.

  1. The relevance of segments reports – measurement methodology

    Directory of Open Access Journals (Sweden)

    Tomasz Zimnicki

    2017-09-01

    Full Text Available The segment report is one of the areas of financial statements, and it obliges a company to provide infor-mation about the economic situation in each of its activity areas. The article evaluates the change of segment reporting standards from IAS14R to IFRS8 in the context of feature relevance. It presents the construction of a measure which allows the relevance of segment disclosures to be determined. The created measure was used to study periodical reports published by companies listed on the main market of the Warsaw Stock Exchange from three reporting periods – 2008, 2009 and 2013. Based on the re-search results, it was found that the change of segment reporting standards from IAS14R to IFRS8 in the context of relevance was legitimate.

  2. PTBS segmentation scheme for synthetic aperture radar

    Science.gov (United States)

    Friedland, Noah S.; Rothwell, Brian J.

    1995-07-01

    The Image Understanding Group at Martin Marietta Technologies in Denver, Colorado has developed a model-based synthetic aperture radar (SAR) automatic target recognition (ATR) system using an integrated resource architecture (IRA). IRA, an adaptive Markov random field (MRF) environment, utilizes information from image, model, and neighborhood resources to create a discrete, 2D feature-based world description (FBWD). The IRA FBWD features are peak, target, background and shadow (PTBS). These features have been shown to be very useful for target discrimination. The FBWD is used to accrue evidence over a model hypothesis set. This paper presents the PTBS segmentation process utilizing two IRA resources. The image resource (IR) provides generic (the physics of image formation) and specific (the given image input) information. The neighborhood resource (NR) provides domain knowledge of localized FBWD site behaviors. A simulated annealing optimization algorithm is used to construct a `most likely' PTBS state. Results on simulated imagery illustrate the power of this technique to correctly segment PTBS features, even when vehicle signatures are immersed in heavy background clutter. These segmentations also suppress sidelobe effects and delineate shadows.

  3. Precision segmented reflectors for space applications

    Science.gov (United States)

    Lehman, David H.; Pawlik, Eugene V.; Meinel, Aden B.; Fichter, W. B.

    1990-08-01

    A project to develop precision segmented reflectors (PSRs) which operate at submillimeter wavelengths is described. The development of a light efficient means for the construction of large-aperture segmented reflecting space-based telescopes is the primary aim of the project. The 20-m Large Deployable Reflector (LDR) telescope is being developed for a survey mission, and it will make use of the reflector panels and materials, structures, and figure control being elaborated for the PSR. The surface accuracy of a 0.9-m PSR panel is shown to be 1.74-micron RMS, the goal of 100-micron RMS positioning accuracy has been achieved for a 4-m erectable structure. A voice-coil actuator for the figure control system architecture demonstrated 1-micron panel control accuracy in a 3-axis evaluation. The PSR technology is demonstrated to be of value for several NASA projects involving optical communications and interferometers as well as missions which make use of large-diameter segmented reflectors.

  4. Region segmentation along image sequence

    International Nuclear Information System (INIS)

    Monchal, L.; Aubry, P.

    1995-01-01

    A method to extract regions in sequence of images is proposed. Regions are not matched from one image to the following one. The result of a region segmentation is used as an initialization to segment the following and image to track the region along the sequence. The image sequence is exploited as a spatio-temporal event. (authors). 12 refs., 8 figs

  5. Market segmentation using perceived constraints

    Science.gov (United States)

    Jinhee Jun; Gerard Kyle; Andrew Mowen

    2008-01-01

    We examined the practical utility of segmenting potential visitors to Cleveland Metroparks using their constraint profiles. Our analysis identified three segments based on their scores on the dimensions of constraints: Other priorities--visitors who scored the highest on 'other priorities' dimension; Highly Constrained--visitors who scored relatively high on...

  6. Market Segmentation: An Instructional Module.

    Science.gov (United States)

    Wright, Peter H.

    A concept-based introduction to market segmentation is provided in this instructional module for undergraduate and graduate transportation-related courses. The material can be used in many disciplines including engineering, business, marketing, and technology. The concept of market segmentation is primarily a transportation planning technique by…

  7. IFRS 8 – OPERATING SEGMENTS

    Directory of Open Access Journals (Sweden)

    BOCHIS LEONICA

    2009-05-01

    Full Text Available Segment reporting in accordance with IFRS 8 will be mandatory for annual financial statements covering periods beginning on or after 1 January 2009. The standards replaces IAS 14, Segment Reporting, from that date. The objective of IFRS 8 is to require

  8. Reduplication Facilitates Early Word Segmentation

    Science.gov (United States)

    Ota, Mitsuhiko; Skarabela, Barbora

    2018-01-01

    This study explores the possibility that early word segmentation is aided by infants' tendency to segment words with repeated syllables ("reduplication"). Twenty-four nine-month-olds were familiarized with passages containing one novel reduplicated word and one novel non-reduplicated word. Their central fixation times in response to…

  9. The Importance of Marketing Segmentation

    Science.gov (United States)

    Martin, Gillian

    2011-01-01

    The rationale behind marketing segmentation is to allow businesses to focus on their consumers' behaviors and purchasing patterns. If done effectively, marketing segmentation allows an organization to achieve its highest return on investment (ROI) in turn for its marketing and sales expenses. If an organization markets its products or services to…

  10. Essays in international market segmentation

    NARCIS (Netherlands)

    Hofstede, ter F.

    1999-01-01

    The primary objective of this thesis is to develop and validate new methodologies to improve the effectiveness of international segmentation strategies. The current status of international market segmentation research is reviewed in an introductory chapter, which provided a number of

  11. Automatic segmentation of blood vessels from retinal fundus images ...

    Indian Academy of Sciences (India)

    The retinal blood vessels were segmented through color space conversion and color channel extraction, image pre-processing, Gabor filtering, image postprocessing, feature construction through application of principal component analysis, k-means clustering and first level classification using Naïve–Bayes classification ...

  12. Construction mathematics

    CERN Document Server

    Virdi, Surinder; Virdi, Narinder Kaur

    2014-01-01

    Construction Mathematics is an introductory level mathematics text, written specifically for students of construction and related disciplines. Learn by tackling exercises based on real-life construction maths. Examples include: costing calculations, labour costs, cost of materials and setting out of building components. Suitable for beginners and easy to follow throughout. Learn the essential basic theory along with the practical necessities. The second edition of this popular textbook is fully updated to match new curricula, and expanded to include even more learning exercises. End of chapter exercises cover a range of theoretical as well as practical problems commonly found in construction practice, and three detailed assignments based on practical tasks give students the opportunity to apply all the knowledge they have gained. Construction Mathematics addresses all the mathematical requirements of Level 2 construction NVQs from City & Guilds/CITB and Edexcel courses, including the BTEC First Diploma in...

  13. FFTF constructibility

    International Nuclear Information System (INIS)

    Weber, S.A.; Hulbert, D.I.

    1975-01-01

    The influence of the design criteria on the constructibility of the Fast Flux Test Facility is described. Specifically, the effects of requirements due to maintenance accessibility, inerting of cells, seismicity, codes, and standards are addressed. The design and construction techniques developed to minimize the impact of the design criteria on cost and schedule are presented with particular emphasis on the cleanliness and humidity controls imposed during construction of the sodium systems. (U.S.)

  14. Méthodes de graphe pour la segmentation d'images et le suivi d'objets dynamiques

    OpenAIRE

    Wang , Xiaofang

    2015-01-01

    Image segmentation is a fundamental problem in computer vision. In particular, unsupervised image segmentation is an important component in many high-level algorithms and practical vision systems. In this dissertation, we propose three methods that approach image segmentation from different angles of graph based methods and are proved powerful to address these problems. Our first method develops an original graph construction method. We also analyze different types of graph construction metho...

  15. LDR segmented mirror technology assessment study

    Science.gov (United States)

    Krim, M.; Russo, J.

    1983-01-01

    In the mid-1990s, NASA plans to orbit a giant telescope, whose aperture may be as great as 30 meters, for infrared and sub-millimeter astronomy. Its primary mirror will be deployed or assembled in orbit from a mosaic of possibly hundreds of mirror segments. Each segment must be shaped to precise curvature tolerances so that diffraction-limited performance will be achieved at 30 micron (nominal operating wavelength). All panels must lie within 1 micron on a theoretical surface described by the optical precipitation of the telescope's primary mirror. To attain diffraction-limited performance, the issues of alignment and/or position sensing, position control of micron tolerances, and structural, thermal, and mechanical considerations for stowing, deploying, and erecting the reflector must be resolved. Radius of curvature precision influences panel size, shape, material, and type of construction. Two superior material choices emerged: fused quartz (sufficiently homogeneous with respect to thermal expansivity to permit a thin shell substrate to be drape molded between graphite dies to a precise enough off-axis asphere for optical finishing on the as-received a segment) and a Pyrex or Duran (less expensive than quartz and formable at lower temperatures). The optimal reflector panel size is between 1-1/2 and 2 meters. Making one, two-meter mirror every two weeks requires new approaches to manufacturing off-axis parabolic or aspheric segments (drape molding on precision dies and subsequent finishing on a nonrotationally symmetric dependent machine). Proof-of-concept developmental programs were identified to prove the feasibility of the materials and manufacturing ideas.

  16. PRINCIPLES AND MODELS OF CONSUMER SEGMENTATION IN THE BANKING PRODUCTS AND SERVICES MARKET

    Directory of Open Access Journals (Sweden)

    Andrey V. Tsarev

    2015-01-01

    Full Text Available The process of segmenting consumers ofbanking products and services connects withconducting marketing research. In the processof customer segmentation it is necessary to identify the factors that affect them. Identifi cation of competitive and consumer factors, in particular, is necessary for marketing decision making andthe development of the segment coverage strategy to reach a segment at all stages of planningmarketing activities and evaluating its effectiveness. After determining the basic segments on macro and micro levels the segment coveragestrategies are developed that should be based onthe results of the segmentation map construction.Banking institutions that implement informationtechnology to facilitate collecting and processingcustomer data, such as CRM-systems, receivemore opportunities to identify the client and provide a competitive position in the market.

  17. Segmental vitiligo with segmental morphea: An autoimmune link?

    Directory of Open Access Journals (Sweden)

    Pravesh Yadav

    2014-01-01

    Full Text Available An 18-year old girl with segmental vitiligo involving the left side of the trunk and left upper limb with segmental morphea involving the right side of trunk and right upper limb without any deeper involvement is illustrated. There was no history of preceding drug intake, vaccination, trauma, radiation therapy, infection, or hormonal therapy. Family history of stable vitiligo in her brother and a history of type II diabetes mellitus in the father were elicited. Screening for autoimmune diseases and antithyroid antibody was negative. An autoimmune link explaining the co-occurrence has been proposed. Cutaneous mosiacism could explain the presence of both the pathologies in a segmental distribution.

  18. Construction Management.

    Science.gov (United States)

    Abbott, James F.

    This article provides a detailed discussion of a team approach to building that involves a construction manager, an architect, and a contractor. Bidding methods are outlined; the major components in construction management -- value engineering and fast track scheduling -- and the use of performance specifications are discussed. The construction…

  19. Construction fraud

    NARCIS (Netherlands)

    Graafland, J.J.; Liedekerke, L.; Dubbink, W.; van Liedekerke, L.; van Luijk, H.

    2011-01-01

    Due to the actions of a whistleblower The Netherlands was confronted with a massive case of construction fraud involving almost the entire construction sector. Price fixing, prior consulting, duplicate accounts, fictitious invoices and active corruption of civil servants were rampant practices. This

  20. Superstring construction

    CERN Document Server

    1989-01-01

    The book includes a selection of papers on the construction of superstring theories, mainly written during the years 1984-1987. It covers ten-dimensional supersymmetric and non-supersymmetric strings, four-dimensional heterotic strings and four-dimensional type-II strings. An introduction to more recent developments in conformal field theory in relation to string construction is provided.

  1. Using Predictability for Lexical Segmentation.

    Science.gov (United States)

    Çöltekin, Çağrı

    2017-09-01

    This study investigates a strategy based on predictability of consecutive sub-lexical units in learning to segment a continuous speech stream into lexical units using computational modeling and simulations. Lexical segmentation is one of the early challenges during language acquisition, and it has been studied extensively through psycholinguistic experiments as well as computational methods. However, despite strong empirical evidence, the explicit use of predictability of basic sub-lexical units in models of segmentation is underexplored. This paper presents an incremental computational model of lexical segmentation for exploring the usefulness of predictability for lexical segmentation. We show that the predictability cue is a strong cue for segmentation. Contrary to earlier reports in the literature, the strategy yields state-of-the-art segmentation performance with an incremental computational model that uses only this particular cue in a cognitively plausible setting. The paper also reports an in-depth analysis of the model, investigating the conditions affecting the usefulness of the strategy. Copyright © 2016 Cognitive Science Society, Inc.

  2. The Hierarchy of Segment Reports

    Directory of Open Access Journals (Sweden)

    Danilo Dorović

    2015-05-01

    Full Text Available The article presents an attempt to find the connection between reports created for managers responsible for different business segments. With this purpose, the hierarchy of the business reporting segments is proposed. This can lead to better understanding of the expenses under common responsibility of more than one manager since these expenses should be in more than one report. The structure of cost defined per business segment hierarchy with the aim of new, unusual but relevant cost structure for management can be established. Both could potentially bring new information benefits for management in the context of profit reporting.

  3. Segmental dilatation of the ileum

    Directory of Open Access Journals (Sweden)

    Tune-Yie Shih

    2017-01-01

    Full Text Available A 2-year-old boy was sent to the emergency department with the chief problem of abdominal pain for 1 day. He was just discharged from the pediatric ward with the diagnosis of mycoplasmal pneumonia and paralytic ileus. After initial examinations and radiographic investigations, midgut volvulus was impressed. An emergency laparotomy was performed. Segmental dilatation of the ileum with volvulus was found. The operative procedure was resection of the dilated ileal segment with anastomosis. The postoperative recovery was uneventful. The unique abnormality of gastrointestinal tract – segmental dilatation of the ileum, is described in details and the literature is reviewed.

  4. Accounting for segment correlations in segmented gamma-ray scans

    International Nuclear Information System (INIS)

    Sheppard, G.A.; Prettyman, T.H.; Piquette, E.C.

    1994-01-01

    In a typical segmented gamma-ray scanner (SGS), the detector's field of view is collimated so that a complete horizontal slice or segment of the desired thickness is visible. Ordinarily, the collimator is not deep enough to exclude gamma rays emitted from sample volumes above and below the segment aligned with the collimator. This can lead to assay biases, particularly for certain radioactive-material distributions. Another consequence of the collimator's low aspect ratio is that segment assays at the top and bottom of the sample are biased low because the detector's field of view is not filled. This effect is ordinarily countered by placing the sample on a low-Z pedestal and scanning one or more segment thicknesses below and above the sample. This takes extra time, however, We have investigated a number of techniques that both account for correlated segments and correct for end effects in SGS assays. Also, we have developed an algorithm that facilitates estimates of assay precision. Six calculation methods have been compared by evaluating the results of thousands of simulated, assays for three types of gamma-ray source distribution and ten masses. We will report on these computational studies and their experimental verification

  5. What are Segments in Google Analytics

    Science.gov (United States)

    Segments find all sessions that meet a specific condition. You can then apply this segment to any report in Google Analytics (GA). Segments are a way of identifying sessions and users while filters identify specific events, like pageviews.

  6. CLG for Automatic Image Segmentation

    OpenAIRE

    Christo Ananth; S.Santhana Priya; S.Manisha; T.Ezhil Jothi; M.S.Ramasubhaeswari

    2017-01-01

    This paper proposes an automatic segmentation method which effectively combines Active Contour Model, Live Wire method and Graph Cut approach (CLG). The aim of Live wire method is to provide control to the user on segmentation process during execution. Active Contour Model provides a statistical model of object shape and appearance to a new image which are built during a training phase. In the graph cut technique, each pixel is represented as a node and the distance between those nodes is rep...

  7. Market segmentation, targeting and positioning

    OpenAIRE

    Camilleri, Mark Anthony

    2017-01-01

    Businesses may not be in a position to satisfy all of their customers, every time. It may prove difficult to meet the exact requirements of each individual customer. People do not have identical preferences, so rarely does one product completely satisfy everyone. Many companies may usually adopt a strategy that is known as target marketing. This strategy involves dividing the market into segments and developing products or services to these segments. A target marketing strategy is focused on ...

  8. Worldwide construction

    International Nuclear Information System (INIS)

    Williamson, M.

    1994-01-01

    The paper lists major construction projects in worldwide processing and pipelining, showing capacities, contractors, estimated costs, and time of construction. The lists are divided into refineries, petrochemical plants, sulfur recovery units, gas processing plants, pipelines, and related fuel facilities. This last classification includes cogeneration plants, coal liquefaction and gasification plants, biomass power plants, geothermal power plants, integrated coal gasification combined-cycle power plants, and a coal briquetting plant

  9. Recognition Using Classification and Segmentation Scoring

    National Research Council Canada - National Science Library

    Kimball, Owen; Ostendorf, Mari; Rohlicek, Robin

    1992-01-01

    .... We describe an approach to connected word recognition that allows the use of segmental information through an explicit decomposition of the recognition criterion into classification and segmentation scoring...

  10. Construction history and construction management

    International Nuclear Information System (INIS)

    Agh, S.

    1999-01-01

    The process of pre-design and design preparation of the Mochovce NPP as well as the construction history of the plant is highlighted, including the financing aspect and problems arising from changes in the technological and other conditions of start-up of the reactor units. The results of international audits performed to improve the level of nuclear safety and implementation of the measures suggested are also described. The milestones of the whole construction process and start-up process, the control and quality system, and the methods of control and management of the complex construction project are outlined. (author)

  11. Methods of evaluating segmentation characteristics and segmentation of major faults

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kie Hwa; Chang, Tae Woo; Kyung, Jai Bok [Seoul National Univ., Seoul (Korea, Republic of)] (and others)

    2000-03-15

    Seismological, geological, and geophysical studies were made for reasonable segmentation of the Ulsan fault and the results are as follows. One- and two- dimensional electrical surveys revealed clearly the fault fracture zone enlarges systematically northward and southward from the vicinity of Mohwa-ri, indicating Mohwa-ri is at the seismic segment boundary. Field Geological survey and microscope observation of fault gouge indicates that the Quaternary faults in the area are reactivated products of the preexisting faults. Trench survey of the Chonbuk fault Galgok-ri revealed thrust faults and cumulative vertical displacement due to faulting during the late Quaternary with about 1.1-1.9 m displacement per event; the latest event occurred from 14000 to 25000 yrs. BP. The seismic survey showed the basement surface os cut by numerous reverse faults and indicated the possibility that the boundary between Kyeongsangbukdo and Kyeongsannamdo may be segment boundary.

  12. Segmentation by Large Scale Hypothesis Testing - Segmentation as Outlier Detection

    DEFF Research Database (Denmark)

    Darkner, Sune; Dahl, Anders Lindbjerg; Larsen, Rasmus

    2010-01-01

    a microscope and we show how the method can handle transparent particles with significant glare point. The method generalizes to other problems. THis is illustrated by applying the method to camera calibration images and MRI of the midsagittal plane for gray and white matter separation and segmentation......We propose a novel and efficient way of performing local image segmentation. For many applications a threshold of pixel intensities is sufficient but determine the appropriate threshold value can be difficult. In cases with large global intensity variation the threshold value has to be adapted...... locally. We propose a method based on large scale hypothesis testing with a consistent method for selecting an appropriate threshold for the given data. By estimating the background distribution we characterize the segment of interest as a set of outliers with a certain probability based on the estimated...

  13. Methods of evaluating segmentation characteristics and segmentation of major faults

    International Nuclear Information System (INIS)

    Lee, Kie Hwa; Chang, Tae Woo; Kyung, Jai Bok

    2000-03-01

    Seismological, geological, and geophysical studies were made for reasonable segmentation of the Ulsan fault and the results are as follows. One- and two- dimensional electrical surveys revealed clearly the fault fracture zone enlarges systematically northward and southward from the vicinity of Mohwa-ri, indicating Mohwa-ri is at the seismic segment boundary. Field Geological survey and microscope observation of fault gouge indicates that the Quaternary faults in the area are reactivated products of the preexisting faults. Trench survey of the Chonbuk fault Galgok-ri revealed thrust faults and cumulative vertical displacement due to faulting during the late Quaternary with about 1.1-1.9 m displacement per event; the latest event occurred from 14000 to 25000 yrs. BP. The seismic survey showed the basement surface os cut by numerous reverse faults and indicated the possibility that the boundary between Kyeongsangbukdo and Kyeongsannamdo may be segment boundary

  14. Construction safety

    CERN Document Server

    Li, Rita Yi Man

    2013-01-01

    A close-to-ideal blend of suburb and city, speedy construction of towers of Babylon, the sparkling proportion of glass and steel buildings’ facade at night showcase the wisdom of humans. They also witness the footsteps, sweats and tears of architects and engineers. Unfortunately, these signatures of human civilizations are swathed in towering figures of construction accidents. Fretting about these on sites, different countries adopt different measures on sites. This book firstly sketches the construction accidents on sites, followed by a review on safety measures in some of the developing countries such as Bermuda, Egypt, Kuwait and China; as well as developed countries, for example, the United States, France and Singapore. It also highlights the enormous compensation costs with the courts’ experiences in the United Kingdom and Hong Kong.

  15. An Algorithm for Morphological Segmentation of Esperanto Words

    Directory of Open Access Journals (Sweden)

    Guinard Theresa

    2016-04-01

    Full Text Available Morphological analysis (finding the component morphemes of a word and tagging morphemes with part-of-speech information is a useful preprocessing step in many natural language processing applications, especially for synthetic languages. Compound words from the constructed language Esperanto are formed by straightforward agglutination, but for many words, there is more than one possible sequence of component morphemes. However, one segmentation is usually more semantically probable than the others. This paper presents a modified n-gram Markov model that finds the most probable segmentation of any Esperanto word, where the model’s states represent morpheme part-of-speech and semantic classes. The overall segmentation accuracy was over 98% for a set of presegmented dictionary words.

  16. Image Mosaic Method Based on SIFT Features of Line Segment

    Directory of Open Access Journals (Sweden)

    Jun Zhu

    2014-01-01

    Full Text Available This paper proposes a novel image mosaic method based on SIFT (Scale Invariant Feature Transform feature of line segment, aiming to resolve incident scaling, rotation, changes in lighting condition, and so on between two images in the panoramic image mosaic process. This method firstly uses Harris corner detection operator to detect key points. Secondly, it constructs directed line segments, describes them with SIFT feature, and matches those directed segments to acquire rough point matching. Finally, Ransac method is used to eliminate wrong pairs in order to accomplish image mosaic. The results from experiment based on four pairs of images show that our method has strong robustness for resolution, lighting, rotation, and scaling.

  17. Multi scales based sparse matrix spectral clustering image segmentation

    Science.gov (United States)

    Liu, Zhongmin; Chen, Zhicai; Li, Zhanming; Hu, Wenjin

    2018-04-01

    In image segmentation, spectral clustering algorithms have to adopt the appropriate scaling parameter to calculate the similarity matrix between the pixels, which may have a great impact on the clustering result. Moreover, when the number of data instance is large, computational complexity and memory use of the algorithm will greatly increase. To solve these two problems, we proposed a new spectral clustering image segmentation algorithm based on multi scales and sparse matrix. We devised a new feature extraction method at first, then extracted the features of image on different scales, at last, using the feature information to construct sparse similarity matrix which can improve the operation efficiency. Compared with traditional spectral clustering algorithm, image segmentation experimental results show our algorithm have better degree of accuracy and robustness.

  18. Constructing sanctions

    DEFF Research Database (Denmark)

    Jaeger, Mark Daniel

    2016-01-01

    such an effect. This paper explores sanctions conflicts as social constructs. It purports that rally-around-the-flag is all but one part of the discursive dimension of sanctions conflicts. Sanctions are intricately connected with the conflict setting they occur in. The study suggests a dialectical relation...... between how opponents perceive conflicts and the meaning of sanctions therein. This nexus of different constructions of sanctions moreover extends to “targeted” sanctions as well: As restrictive measures against Zimbabwe demonstrate, they are not the kind of minimally-invasive operations with clinical...

  19. Phase congruency map driven brain tumour segmentation

    Science.gov (United States)

    Szilágyi, Tünde; Brady, Michael; Berényi, Ervin

    2015-03-01

    Computer Aided Diagnostic (CAD) systems are already of proven value in healthcare, especially for surgical planning, nevertheless much remains to be done. Gliomas are the most common brain tumours (70%) in adults, with a survival time of just 2-3 months if detected at WHO grades III or higher. Such tumours are extremely variable, necessitating multi-modal Magnetic Resonance Images (MRI). The use of Gadolinium-based contrast agents is only relevant at later stages of the disease where it highlights the enhancing rim of the tumour. Currently, there is no single accepted method that can be used as a reference. There are three main challenges with such images: to decide whether there is tumour present and is so localize it; to construct a mask that separates healthy and diseased tissue; and to differentiate between the tumour core and the surrounding oedema. This paper presents two contributions. First, we develop tumour seed selection based on multiscale multi-modal texture feature vectors. Second, we develop a method based on a local phase congruency based feature map to drive level-set segmentation. The segmentations achieved with our method are more accurate than previously presented methods, particularly for challenging low grade tumours.

  20. Automatic segmentation of psoriasis lesions

    Science.gov (United States)

    Ning, Yang; Shi, Chenbo; Wang, Li; Shu, Chang

    2014-10-01

    The automatic segmentation of psoriatic lesions is widely researched these years. It is an important step in Computer-aid methods of calculating PASI for estimation of lesions. Currently those algorithms can only handle single erythema or only deal with scaling segmentation. In practice, scaling and erythema are often mixed together. In order to get the segmentation of lesions area - this paper proposes an algorithm based on Random forests with color and texture features. The algorithm has three steps. The first step, the polarized light is applied based on the skin's Tyndall-effect in the imaging to eliminate the reflection and Lab color space are used for fitting the human perception. The second step, sliding window and its sub windows are used to get textural feature and color feature. In this step, a feature of image roughness has been defined, so that scaling can be easily separated from normal skin. In the end, Random forests will be used to ensure the generalization ability of the algorithm. This algorithm can give reliable segmentation results even the image has different lighting conditions, skin types. In the data set offered by Union Hospital, more than 90% images can be segmented accurately.

  1. Skip segment Hirschsprung disease and Waardenburg syndrome

    Directory of Open Access Journals (Sweden)

    Erica R. Gross

    2015-04-01

    Full Text Available Skip segment Hirschsprung disease describes a segment of ganglionated bowel between two segments of aganglionated bowel. It is a rare phenomenon that is difficult to diagnose. We describe a recent case of skip segment Hirschsprung disease in a neonate with a family history of Waardenburg syndrome and the genetic profile that was identified.

  2. U.S. Army Custom Segmentation System

    Science.gov (United States)

    2007-06-01

    segmentation is individual or intergroup differences in response to marketing - mix variables. Presumptions about segments: •different demands in a...product or service category, •respond differently to changes in the marketing mix Criteria for segments: •The segments must exist in the environment

  3. Skip segment Hirschsprung disease and Waardenburg syndrome

    OpenAIRE

    Gross, Erica R.; Geddes, Gabrielle C.; McCarrier, Julie A.; Jarzembowski, Jason A.; Arca, Marjorie J.

    2015-01-01

    Skip segment Hirschsprung disease describes a segment of ganglionated bowel between two segments of aganglionated bowel. It is a rare phenomenon that is difficult to diagnose. We describe a recent case of skip segment Hirschsprung disease in a neonate with a family history of Waardenburg syndrome and the genetic profile that was identified.

  4. Design and construction of the Soegawa viaduct; Soegawa kokakyo no sekkei to seko

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, M.; Sueoka, M. [Japan Highway Public Corporation, Tokyo (Japan); Takahashi, M.; Ito, K. [Kajima Corp., Tokyo (Japan)

    1997-09-30

    This paper describes the precast segment construction of double-span continuous prestressed concrete (PC) box girder with a length of 93 m in the Soegawa Viaduct in Akita Prefecture. The match cast surface of the newly constructed segment is occasionally deformed into arch due to the temperature gradient generated by the hardening heat. To avoid this phenomenon, the minimum segment length more than one-sixth of the segment width of 11.2 m was determined. Compatible type internal/external cable method was adopted for the configuration of PC steel members in the main direction. In this method, steel members for PC were placed outside of concrete as well as inside of concrete. The yard for fabricating segments was made in the back area of abutment of the bridge. Segments fabricated using steel frames were brought in the yard using a crane and stocked. After the support construction, segments were constructed from No.1 segment in order. Since placing accuracy of the whole segments was affected by the placing of the standard segment, the accuracy was improved by the three-dimensional control using surveying equipment. After the construction of segments and tension of PC, the bridge is to be completed in September, 1997. 3 refs., 21 figs., 4 tabs.

  5. Construction work

    CERN Multimedia

    2004-01-01

    Construction work on building 179 will start on the 16th February 2004 and continue until November 2004. The road between buildings 179 and 158 will temporarily become a one way street from Route Democrite towards building 7. The parking places between buildings 179 and 7 will become obsolete. The ISOLDE collaboration would like to apologize for any inconveniences.

  6. A Novel Iris Segmentation Scheme

    Directory of Open Access Journals (Sweden)

    Chen-Chung Liu

    2014-01-01

    Full Text Available One of the key steps in the iris recognition system is the accurate iris segmentation from its surrounding noises including pupil, sclera, eyelashes, and eyebrows of a captured eye-image. This paper presents a novel iris segmentation scheme which utilizes the orientation matching transform to outline the outer and inner iris boundaries initially. It then employs Delogne-Kåsa circle fitting (instead of the traditional Hough transform to further eliminate the outlier points to extract a more precise iris area from an eye-image. In the extracted iris region, the proposed scheme further utilizes the differences in the intensity and positional characteristics of the iris, eyelid, and eyelashes to detect and delete these noises. The scheme is then applied on iris image database, UBIRIS.v1. The experimental results show that the presented scheme provides a more effective and efficient iris segmentation than other conventional methods.

  7. MR brain scan tissues and structures segmentation: local cooperative Markovian agents and Bayesian formulation

    International Nuclear Information System (INIS)

    Scherrer, B.

    2008-12-01

    Accurate magnetic resonance brain scan segmentation is critical in a number of clinical and neuroscience applications. This task is challenging due to artifacts, low contrast between tissues and inter-individual variability that inhibit the introduction of a priori knowledge. In this thesis, we propose a new MR brain scan segmentation approach. Unique features of this approach include (1) the coupling of tissue segmentation, structure segmentation and prior knowledge construction, and (2) the consideration of local image properties. Locality is modeled through a multi-agent framework: agents are distributed into the volume and perform a local Markovian segmentation. As an initial approach (LOCUS, Local Cooperative Unified Segmentation), intuitive cooperation and coupling mechanisms are proposed to ensure the consistency of local models. Structures are segmented via the introduction of spatial localization constraints based on fuzzy spatial relations between structures. In a second approach, (LOCUS-B, LOCUS in a Bayesian framework) we consider the introduction of a statistical atlas to describe structures. The problem is reformulated in a Bayesian framework, allowing a statistical formalization of coupling and cooperation. Tissue segmentation, local model regularization, structure segmentation and local affine atlas registration are then coupled in an EM framework and mutually improve. The evaluation on simulated and real images shows good results, and in particular, a robustness to non-uniformity and noise with low computational cost. Local distributed and cooperative MRF models then appear as a powerful and promising approach for medical image segmentation. (author)

  8. Document segmentation via oblique cuts

    Science.gov (United States)

    Svendsen, Jeremy; Branzan-Albu, Alexandra

    2013-01-01

    This paper presents a novel solution for the layout segmentation of graphical elements in Business Intelligence documents. We propose a generalization of the recursive X-Y cut algorithm, which allows for cutting along arbitrary oblique directions. An intermediate processing step consisting of line and solid region removal is also necessary due to presence of decorative elements. The output of the proposed segmentation is a hierarchical structure which allows for the identification of primitives in pie and bar charts. The algorithm was tested on a database composed of charts from business documents. Results are very promising.

  9. Optimally segmented permanent magnet structures

    DEFF Research Database (Denmark)

    Insinga, Andrea Roberto; Bjørk, Rasmus; Smith, Anders

    2016-01-01

    We present an optimization approach which can be employed to calculate the globally optimal segmentation of a two-dimensional magnetic system into uniformly magnetized pieces. For each segment the algorithm calculates the optimal shape and the optimal direction of the remanent flux density vector......, with respect to a linear objective functional. We illustrate the approach with results for magnet design problems from different areas, such as a permanent magnet electric motor, a beam focusing quadrupole magnet for particle accelerators and a rotary device for magnetic refrigeration....

  10. Intercalary bone segment transport in treatment of segmental tibial defects

    International Nuclear Information System (INIS)

    Iqbal, A.; Amin, M.S.

    2002-01-01

    Objective: To evaluate the results and complications of intercalary bone segment transport in the treatment of segmental tibial defects. Design: This is a retrospective analysis of patients with segmental tibial defects who were treated with intercalary bone segment transport method. Place and Duration of Study: The study was carried out at Combined Military Hospital, Rawalpindi from September 1997 to April 2001. Subjects and methods: Thirteen patients were included in the study who had developed tibial defects either due to open fractures with bone loss or subsequent to bone debridement of infected non unions. The mean bone defect was 6.4 cms and there were eight associated soft tissue defects. Locally made unilateral 'Naseer-Awais' (NA) fixator was used for bone segment transport. The distraction was done at the rate of 1mm/day after 7-10 days of osteotomy. The patients were followed-up fortnightly during distraction and monthly thereafter. The mean follow-up duration was 18 months. Results: The mean time in external fixation was 9.4 months. The m ean healing index' was 1.47 months/cm. Satisfactory union was achieved in all cases. Six cases (46.2%) required bone grafting at target site and in one of them grafting was required at the level of regeneration as well. All the wounds healed well with no residual infection. There was no residual leg length discrepancy of more than 20 mm nd one angular deformity of more than 5 degrees. The commonest complication encountered was pin track infection seen in 38% of Shanz Screws applied. Loosening occurred in 6.8% of Shanz screws, requiring re-adjustment. Ankle joint contracture with equinus deformity and peroneal nerve paresis occurred in one case each. The functional results were graded as 'good' in seven, 'fair' in four, and 'poor' in two patients. Overall, thirteen patients had 31 (minor/major) complications with a ratio of 2.38 complications per patient. To treat the bone defects and associated complications, a mean of

  11. Soft segmented inchworm robot with dielectric elastomer muscles

    Science.gov (United States)

    Conn, Andrew T.; Hinitt, Andrew D.; Wang, Pengchuan

    2014-03-01

    Robotic devices typically utilize rigid components in order to produce precise and robust operation. Rigidity becomes a significant impediment, however, when navigating confined or constricted environments e.g. search-and-rescue, industrial pipe inspection. In such cases adaptively conformable soft structures become optimal. Dielectric elastomers (DEs) are well suited for developing such soft robots since they are inherently compliant and can produce large musclelike actuation strains. In this paper, a soft segmented inchworm robot is presented that utilizes pneumatically-coupled DE membranes to produce inchworm-like locomotion. The robot is constructed from repeated body segments, each with a simple control architecture, so that the total length can be readily adapted by adding or removing segments. Each segment consists of a soft inflatable shell (internal pressure in range of 1.0-15.9 mBar) and a pair of antagonistic DE membranes (VHB 4905). Experimental testing of a single body segment is presented and the relationship between drive voltage, pneumatic pressure and active displacement is characterized. This demonstrates that pneumatic coupling of DE membranes induces complex non-linear electro-mechanical behaviour as drive voltage and pneumatic pressure are altered. Locomotion of a two-segment inchworm robot prototype with a passive length of 80 mm is presented. Artificial setae are included on the body shell to generate anisotropic friction for locomotion. A maximum locomotion speed of 4.1 mm/s was recorded at a drive frequency of 1.5 Hz, which compares favourably to biological counterparts. Future development of the soft inchworm robot are discussed including reflexive low-level control of individual segments.

  12. A Vision Chip for Color Segmentation and Pattern Matching

    Directory of Open Access Journals (Sweden)

    Ralph Etienne-Cummings

    2003-06-01

    Full Text Available A 128(H × 64(V × RGB CMOS imager is integrated with region-of-interest selection, RGB-to-HSI transformation, HSI-based pixel segmentation, (36bins × 12bits-HSI histogramming, and sum-of-absolute-difference (SAD template matching. Thirty-two learned color templates are stored and compared to each image. The chip captures the R, G, and B images using in-pixel storage before passing the pixel content to a multiplying digital-to-analog converter (DAC for white balancing. The DAC can also be used to pipe in images for a PC. The color processing uses a biologically inspired color opponent representation and an analog lookup table to determine the Hue (H of each pixel. Saturation (S is computed using a loser-take-all circuit. Intensity (I is given by the sum of the color components. A histogram of the segments of the image, constructed by counting the number of pixels falling into 36 Hue intervals of 10 degrees, is stored on a chip and compared against the histograms of new segments using SAD comparisons. We demonstrate color-based image segmentation and object recognition with this chip. Running at 30 fps, it uses 1 mW. To our knowledge, this is the first chip that integrates imaging, color segmentation, and color-based object recognition at the focal plane.

  13. The deformation behavior of the cervical spine segment

    Science.gov (United States)

    Kolmakova, T. V.; Rikun, Yu. A.

    2017-09-01

    The paper describes the model of the cervical spine segment (C3-C4) and the calculation results of its deformation behavior at flexion. The segment model was built based on the experimental literature data taking into account the presence of the cortical and cancellous bone tissue of vertebral bodies. Degenerative changes of the intervertebral disk (IVD) were simulated through a reduction of the disc height and an increase of Young's modulus. The construction of the geometric model of the cervical spine segment and the calculations of the stress-strain state were carried out in the ANSYS software complex. The calculation results show that the biggest protrusion of the IVD in bending direction of segment is observed when IVD height is reduced. The disc protrusion is reduced with an increase of Young's modulus. The largest protrusion in the direction of flexion of the segment is the intervertebral disk with height of 4.3 mm and elastic modulus of 2.5 MPa. The results of the study can be useful to specialists in the field of biomechanics, medical materials science and prosthetics.

  14. Hydrophilic segmented block copolymers based on poly(ethylene oxide) and monodisperse amide segments

    NARCIS (Netherlands)

    Husken, D.; Feijen, Jan; Gaymans, R.J.

    2007-01-01

    Segmented block copolymers based on poly(ethylene oxide) (PEO) flexible segments and monodisperse crystallizable bisester tetra-amide segments were made via a polycondensation reaction. The molecular weight of the PEO segments varied from 600 to 4600 g/mol and a bisester tetra-amide segment (T6T6T)

  15. Modelling Constructs

    DEFF Research Database (Denmark)

    Kindler, Ekkart

    2009-01-01

    , these notations have been extended in order to increase expressiveness and to be more competitive. This resulted in an increasing number of notations and formalisms for modelling business processes and in an increase of the different modelling constructs provided by modelling notations, which makes it difficult......There are many different notations and formalisms for modelling business processes and workflows. These notations and formalisms have been introduced with different purposes and objectives. Later, influenced by other notations, comparisons with other tools, or by standardization efforts...... to compare modelling notations and to make transformations between them. One of the reasons is that, in each notation, the new concepts are introduced in a different way by extending the already existing constructs. In this chapter, we go the opposite direction: We show that it is possible to add most...

  16. Construction of calibration curve for accountancy tank

    International Nuclear Information System (INIS)

    Kato, Takayuki; Goto, Yoshiki; Nidaira, Kazuo

    2009-01-01

    Tanks are equipped in a reprocessing plant for accounting solution of nuclear material. The careful measurement of volume in tanks is very important to implement rigorous accounting of nuclear material. The calibration curve relating the volume and level of solution needs to be constructed, where the level is determined by differential pressure of dip tubes. Several calibration curves are usually employed, but it's not explicitly decided how many segment are used, where to select segment, or what should be the degree of polynomial curve. These parameters, i.e., segment and degree of polynomial curve are mutually interrelated to give the better performance of calibration curve. Here we present the construction technique of giving optimum calibration curves and their characteristics. (author)

  17. Dictionary Based Segmentation in Volumes

    DEFF Research Database (Denmark)

    Emerson, Monica Jane; Jespersen, Kristine Munk; Jørgensen, Peter Stanley

    Method for supervised segmentation of volumetric data. The method is trained from manual annotations, and these annotations make the method very flexible, which we demonstrate in our experiments. Our method infers label information locally by matching the pattern in a neighborhood around a voxel ...... to a dictionary, and hereby accounts for the volume texture....

  18. Segmenting Trajectories by Movement States

    NARCIS (Netherlands)

    Buchin, M.; Kruckenberg, H.; Kölzsch, A.; Timpf, S.; Laube, P.

    2013-01-01

    Dividing movement trajectories according to different movement states of animals has become a challenge in movement ecology, as well as in algorithm development. In this study, we revisit and extend a framework for trajectory segmentation based on spatio-temporal criteria for this purpose. We adapt

  19. Segmental Colitis Complicating Diverticular Disease

    Directory of Open Access Journals (Sweden)

    Guido Ma Van Rosendaal

    1996-01-01

    Full Text Available Two cases of idiopathic colitis affecting the sigmoid colon in elderly patients with underlying diverticulosis are presented. Segmental resection has permitted close review of the histopathology in this syndrome which demonstrates considerable similarity to changes seen in idiopathic ulcerative colitis. The reported experience with this syndrome and its clinical features are reviewed.

  20. Leaf segmentation in plant phenotyping

    NARCIS (Netherlands)

    Scharr, Hanno; Minervini, Massimo; French, Andrew P.; Klukas, Christian; Kramer, David M.; Liu, Xiaoming; Luengo, Imanol; Pape, Jean Michel; Polder, Gerrit; Vukadinovic, Danijela; Yin, Xi; Tsaftaris, Sotirios A.

    2016-01-01

    Image-based plant phenotyping is a growing application area of computer vision in agriculture. A key task is the segmentation of all individual leaves in images. Here we focus on the most common rosette model plants, Arabidopsis and young tobacco. Although leaves do share appearance and shape

  1. Probabilistic liver atlas construction.

    Science.gov (United States)

    Dura, Esther; Domingo, Juan; Ayala, Guillermo; Marti-Bonmati, Luis; Goceri, E

    2017-01-13

    Anatomical atlases are 3D volumes or shapes representing an organ or structure of the human body. They contain either the prototypical shape of the object of interest together with other shapes representing its statistical variations (statistical atlas) or a probability map of belonging to the object (probabilistic atlas). Probabilistic atlases are mostly built with simple estimations only involving the data at each spatial location. A new method for probabilistic atlas construction that uses a generalized linear model is proposed. This method aims to improve the estimation of the probability to be covered by the liver. Furthermore, all methods to build an atlas involve previous coregistration of the sample of shapes available. The influence of the geometrical transformation adopted for registration in the quality of the final atlas has not been sufficiently investigated. The ability of an atlas to adapt to a new case is one of the most important quality criteria that should be taken into account. The presented experiments show that some methods for atlas construction are severely affected by the previous coregistration step. We show the good performance of the new approach. Furthermore, results suggest that extremely flexible registration methods are not always beneficial, since they can reduce the variability of the atlas and hence its ability to give sensible values of probability when used as an aid in segmentation of new cases.

  2. Joint shape segmentation with linear programming

    KAUST Repository

    Huang, Qixing

    2011-01-01

    We present an approach to segmenting shapes in a heterogenous shape database. Our approach segments the shapes jointly, utilizing features from multiple shapes to improve the segmentation of each. The approach is entirely unsupervised and is based on an integer quadratic programming formulation of the joint segmentation problem. The program optimizes over possible segmentations of individual shapes as well as over possible correspondences between segments from multiple shapes. The integer quadratic program is solved via a linear programming relaxation, using a block coordinate descent procedure that makes the optimization feasible for large databases. We evaluate the presented approach on the Princeton segmentation benchmark and show that joint shape segmentation significantly outperforms single-shape segmentation techniques. © 2011 ACM.

  3. A method for robust segmentation of arbitrarily shaped radiopaque structures in cone-beam CT projections

    International Nuclear Information System (INIS)

    Poulsen, Per Rugaard; Fledelius, Walther; Keall, Paul J.; Weiss, Elisabeth; Lu Jun; Brackbill, Emily; Hugo, Geoffrey D.

    2011-01-01

    Purpose: Implanted markers are commonly used in radiotherapy for x-ray based target localization. The projected marker position in a series of cone-beam CT (CBCT) projections can be used to estimate the three dimensional (3D) target trajectory during the CBCT acquisition. This has important applications in tumor motion management such as motion inclusive, gating, and tumor tracking strategies. However, for irregularly shaped markers, reliable segmentation is challenged by large variations in the marker shape with projection angle. The purpose of this study was to develop a semiautomated method for robust and reliable segmentation of arbitrarily shaped radiopaque markers in CBCT projections. Methods: The segmentation method involved the following three steps: (1) Threshold based segmentation of the marker in three to six selected projections with large angular separation, good marker contrast, and uniform background; (2) construction of a 3D marker model by coalignment and backprojection of the threshold-based segmentations; and (3) construction of marker templates at all imaging angles by projection of the 3D model and use of these templates for template-based segmentation. The versatility of the segmentation method was demonstrated by segmentation of the following structures in the projections from two clinical CBCT scans: (1) Three linear fiducial markers (Visicoil) implanted in or near a lung tumor and (2) an artificial cardiac valve in a lung cancer patient. Results: Automatic marker segmentation was obtained in more than 99.9% of the cases. The segmentation failed in a few cases where the marker was either close to a structure of similar appearance or hidden behind a dense structure (data cable). Conclusions: A robust template-based method for segmentation of arbitrarily shaped radiopaque markers in CBCT projections was developed.

  4. Study on Load-displacement Test of Rubber Pads of Coal Mine Roadway Constructed by Shield

    Science.gov (United States)

    Yang, Yue; Chen, Xiaoguo; Yang, Liyun

    2017-12-01

    Shield method construction of coal mine roadway is the future trend of the development of deep coal mining. The main shaft supporting is the segment. There is rubber pads between segment and segment. The performance of compression deformation of rubber pad is essential for the overall stability of lining. Through load test, displacement of the rubber pad under load, the thrust force law of the rubber pad deformation, and provide a theoretical basis for the stability analysis of coal mine tunnel shield construction.

  5. Constructing Catalonia

    Directory of Open Access Journals (Sweden)

    Bill Philips

    2009-07-01

    Full Text Available Catalonia, in common with other nations, has long been concerned with the question of identity and difference. Its problematic relationship with Spain has led to an emphasis on differentiating itself from its larger neighbour (if we are to accept, as most Spaniards do not, that Catalonia is not Spain, a situation complicated by the loss of the Spanish colonies of Cuba and The Philippines in 1898, and the Spanish Civil War and subsequent dictatorship from 1936 to 1976. Beginning in the late nineteenth century, the construction of a Catalan identity followed a similar route to that taken by other European nations such as England, Ireland and, indeed, Spain, including an emphasis on rural values, activities and the countryside, and the conversion of specifically local traditions into national past times. It is only in the last ten years or so that this model of Catalan identity has been recognised for what it is – a model constructed and encouraged for and by specific nationalist political interests. Ironically, Catalonia’s identity abroad has also been constructed and manipulated for political purposes, but from quite a different perspective. Orwell’s /Homage to Catalonia/ (1938 narrates an extremely blinkered version of the Spanish Civil War which has achieved iconic status as a result of cold war politics. Subsequent portrayals of the Spanish Civil War – Valentine Cunningham’s /The Penguin Book of Spanish Civil War Verse/ (ed., Penguin, 1980, or Ken Loach’s 1995 film /Land and Freedom/ base their arguments unquestioningly on /Homage to Catalonia/, perpetuating a view of the nation’s recent history that is both reductive and inaccurate

  6. Layout Construction

    DEFF Research Database (Denmark)

    Frandsen, Gudmund Skovbjerg; Palsberg, Jens; Schmidt, Erik Meineche

    We design a system for generating newspaper layout proposals. The input to the system consists of editorial information (text, pictures, etc) and style information (non-editorial information that specifies the aesthetic appearance of a layout). We consider the automation of layout construction...... to pose two main problems. One problem consists in optimizing the layout with respect to the constraints and preferences specified in the style information. Another problem consists in finding a representation of the style information that both supports its use in the combinatorial optimization...

  7. Contextually guided very-high-resolution imagery classification with semantic segments

    Science.gov (United States)

    Zhao, Wenzhi; Du, Shihong; Wang, Qiao; Emery, William J.

    2017-10-01

    Contextual information, revealing relationships and dependencies between image objects, is one of the most important information for the successful interpretation of very-high-resolution (VHR) remote sensing imagery. Over the last decade, geographic object-based image analysis (GEOBIA) technique has been widely used to first divide images into homogeneous parts, and then to assign semantic labels according to the properties of image segments. However, due to the complexity and heterogeneity of VHR images, segments without semantic labels (i.e., semantic-free segments) generated with low-level features often fail to represent geographic entities (such as building roofs usually be partitioned into chimney/antenna/shadow parts). As a result, it is hard to capture contextual information across geographic entities when using semantic-free segments. In contrast to low-level features, "deep" features can be used to build robust segments with accurate labels (i.e., semantic segments) in order to represent geographic entities at higher levels. Based on these semantic segments, semantic graphs can be constructed to capture contextual information in VHR images. In this paper, semantic segments were first explored with convolutional neural networks (CNN) and a conditional random field (CRF) model was then applied to model the contextual information between semantic segments. Experimental results on two challenging VHR datasets (i.e., the Vaihingen and Beijing scenes) indicate that the proposed method is an improvement over existing image classification techniques in classification performance (overall accuracy ranges from 82% to 96%).

  8. Dictionary Based Segmentation in Volumes

    DEFF Research Database (Denmark)

    Emerson, Monica Jane; Jespersen, Kristine Munk; Jørgensen, Peter Stanley

    2015-01-01

    We present a method for supervised volumetric segmentation based on a dictionary of small cubes composed of pairs of intensity and label cubes. Intensity cubes are small image volumes where each voxel contains an image intensity. Label cubes are volumes with voxelwise probabilities for a given...... label. The segmentation process is done by matching a cube from the volume, of the same size as the dictionary intensity cubes, to the most similar intensity dictionary cube, and from the associated label cube we get voxel-wise label probabilities. Probabilities from overlapping cubes are averaged...... and hereby we obtain a robust label probability encoding. The dictionary is computed from labeled volumetric image data based on weighted clustering. We experimentally demonstrate our method using two data sets from material science – a phantom data set of a solid oxide fuel cell simulation for detecting...

  9. Compliance with Segment Disclosure Initiatives

    DEFF Research Database (Denmark)

    Arya, Anil; Frimor, Hans; Mittendorf, Brian

    2013-01-01

    Regulatory oversight of capital markets has intensified in recent years, with a particular emphasis on expanding financial transparency. A notable instance is efforts by the Financial Accounting Standards Board that push firms to identify and report performance of individual business units...... (segments). This paper seeks to address short-run and long-run consequences of stringent enforcement of and uniform compliance with these segment disclosure standards. To do so, we develop a parsimonious model wherein a regulatory agency promulgates disclosure standards and either permits voluntary...... by increasing transparency and leveling the playing field. However, our analysis also demonstrates that in the long run, if firms are unable to use discretion in reporting to maintain their competitive edge, they may seek more destructive alternatives. Accounting for such concerns, in the long run, voluntary...

  10. Segmental osteotomies of the maxilla.

    Science.gov (United States)

    Rosen, H M

    1989-10-01

    Multiple segment Le Fort I osteotomies provide the maxillofacial surgeon with the capabilities to treat complex dentofacial deformities existing in all three planes of space. Sagittal, vertical, and transverse maxillomandibular discrepancies as well as three-dimensional abnormalities within the maxillary arch can be corrected simultaneously. Accordingly, optimal aesthetic enhancement of the facial skeleton and a functional, healthy occlusion can be realized. What may be perceived as elaborate treatment plans are in reality conservative in terms of osseous stability and treatment time required. The close cooperation of an orthodontist well-versed in segmental orthodontics and orthognathic surgery is critical to the success of such surgery. With close attention to surgical detail, the complication rate inherent in such surgery can be minimized and the treatment goals achieved in a timely and predictable fashion.

  11. Segmented fuel and moderator rod

    International Nuclear Information System (INIS)

    Doshi, P.K.

    1987-01-01

    This patent describes a continuous segmented fuel and moderator rod for use with a water cooled and moderated nuclear fuel assembly. The rod comprises: a lower fuel region containing a column of nuclear fuel; a moderator region, disposed axially above the fuel region. The moderator region has means for admitting and passing the water moderator therethrough for moderating an upper portion of the nuclear fuel assembly. The moderator region is separated from the fuel region by a water tight separator

  12. Segmentation of sows in farrowing pens

    DEFF Research Database (Denmark)

    Tu, Gang Jun; Karstoft, Henrik; Pedersen, Lene Juul

    2014-01-01

    The correct segmentation of a foreground object in video recordings is an important task for many surveillance systems. The development of an effective and practical algorithm to segment sows in grayscale video recordings captured under commercial production conditions is described...

  13. Segmentation in local hospital markets.

    Science.gov (United States)

    Dranove, D; White, W D; Wu, L

    1993-01-01

    This study examines evidence of market segmentation on the basis of patients' insurance status, demographic characteristics, and medical condition in selected local markets in California in the years 1983 and 1989. Substantial differences exist in the probability patients may be admitted to particular hospitals based on insurance coverage, particularly Medicaid, and race. Segmentation based on insurance and race is related to hospital characteristics, but not the characteristics of the hospital's community. Medicaid patients are more likely to go to hospitals with lower costs and fewer service offerings. Privately insured patients go to hospitals offering more services, although cost concerns are increasing. Hispanic patients also go to low-cost hospitals, ceteris paribus. Results indicate little evidence of segmentation based on medical condition in either 1983 or 1989, suggesting that "centers of excellence" have yet to play an important role in patient choice of hospital. The authors found that distance matters, and that patients prefer nearby hospitals, moreso for some medical conditions than others, in ways consistent with economic theories of consumer choice.

  14. Feed-forward segmentation of figure-ground and assignment of border-ownership.

    Directory of Open Access Journals (Sweden)

    Hans Supèr

    Full Text Available Figure-ground is the segmentation of visual information into objects and their surrounding backgrounds. Two main processes herein are boundary assignment and surface segregation, which rely on the integration of global scene information. Recurrent processing either by intrinsic horizontal connections that connect surrounding neurons or by feedback projections from higher visual areas provide such information, and are considered to be the neural substrate for figure-ground segmentation. On the contrary, a role of feedforward projections in figure-ground segmentation is unknown. To have a better understanding of a role of feedforward connections in figure-ground organization, we constructed a feedforward spiking model using a biologically plausible neuron model. By means of surround inhibition our simple 3-layered model performs figure-ground segmentation and one-sided border-ownership coding. We propose that the visual system uses feed forward suppression for figure-ground segmentation and border-ownership assignment.

  15. Feed-forward segmentation of figure-ground and assignment of border-ownership.

    Science.gov (United States)

    Supèr, Hans; Romeo, August; Keil, Matthias

    2010-05-19

    Figure-ground is the segmentation of visual information into objects and their surrounding backgrounds. Two main processes herein are boundary assignment and surface segregation, which rely on the integration of global scene information. Recurrent processing either by intrinsic horizontal connections that connect surrounding neurons or by feedback projections from higher visual areas provide such information, and are considered to be the neural substrate for figure-ground segmentation. On the contrary, a role of feedforward projections in figure-ground segmentation is unknown. To have a better understanding of a role of feedforward connections in figure-ground organization, we constructed a feedforward spiking model using a biologically plausible neuron model. By means of surround inhibition our simple 3-layered model performs figure-ground segmentation and one-sided border-ownership coding. We propose that the visual system uses feed forward suppression for figure-ground segmentation and border-ownership assignment.

  16. Roentgenological diagnoss of central segmental lung cancer

    International Nuclear Information System (INIS)

    Gurevich, L.A.; Fedchenko, G.G.

    1984-01-01

    Basing on an analysis of the results of clinicoroentgenological examination of 268 patments roentgenological semiotics of segmental lung cancer is presented. Some peculiarities of the X-ray picture of cancer of different segments of the lungs were revealed depending on tumor site and growth type. For the syndrome of segmental darkening the comprehensive X-ray methods where the chief method is tomography of the segmental bronchi are proposed

  17. Review of segmentation process in consumer markets

    OpenAIRE

    Veronika Jadczaková

    2013-01-01

    Although there has been a considerable debate on market segmentation over five decades, attention was merely devoted to single stages of the segmentation process. In doing so, stages as segmentation base selection or segments profiling have been heavily covered in the extant literature, whereas stages as implementation of the marketing strategy or market definition were of a comparably lower interest. Capitalizing on this shortcoming, this paper strives to close the gap and provide each step...

  18. Market Segmentation from a Behavioral Perspective

    Science.gov (United States)

    Wells, Victoria K.; Chang, Shing Wan; Oliveira-Castro, Jorge; Pallister, John

    2010-01-01

    A segmentation approach is presented using both traditional demographic segmentation bases (age, social class/occupation, and working status) and a segmentation by benefits sought. The benefits sought in this case are utilitarian and informational reinforcement, variables developed from the Behavioral Perspective Model (BPM). Using data from 1,847…

  19. Parallel fuzzy connected image segmentation on GPU

    OpenAIRE

    Zhuge, Ying; Cao, Yong; Udupa, Jayaram K.; Miller, Robert W.

    2011-01-01

    Purpose: Image segmentation techniques using fuzzy connectedness (FC) principles have shown their effectiveness in segmenting a variety of objects in several large applications. However, one challenge in these algorithms has been their excessive computational requirements when processing large image datasets. Nowadays, commodity graphics hardware provides a highly parallel computing environment. In this paper, the authors present a parallel fuzzy connected image segmentation algorithm impleme...

  20. LIFE-STYLE SEGMENTATION WITH TAILORED INTERVIEWING

    NARCIS (Netherlands)

    KAMAKURA, WA; WEDEL, M

    The authors present a tailored interviewing procedure for life-style segmentation. The procedure assumes that a life-style measurement instrument has been designed. A classification of a sample of consumers into life-style segments is obtained using a latent-class model. With these segments, the

  1. The Process of Marketing Segmentation Strategy Selection

    OpenAIRE

    Ionel Dumitru

    2007-01-01

    The process of marketing segmentation strategy selection represents the essence of strategical marketing. We present hereinafter the main forms of the marketing statategy segmentation: undifferentiated marketing, differentiated marketing, concentrated marketing and personalized marketing. In practice, the companies use a mix of these marketing segmentation methods in order to maximize the proffit and to satisfy the consumers’ needs.

  2. Development of rock segment for reduction of amount of cement use

    International Nuclear Information System (INIS)

    Tada, Hiroyuki; Kumasaka, Hiroo; Saito, Akira; Nakaya, Atsushi; Ishii, Takashi; Sanada, Masanori; Noguchi, Akira; Kishi, Hirokazu; Nakama, Shigeo; Fujita, Tomoo

    2013-01-01

    The authors have been developing methods for constructing tunnels using the minimum quantities of cement-type support materials in high-level radioactive waste disposal facilities and advancing research and development about the technical formation of rock segment using low alkali mortar. In this study, the mechanical characteristic values concerning the rock segment and backfill materials were examined. The stability analysis of drift supported by the rock segment and backfilling with gravel were performed. Technical formation and effectiveness of the support planned for further reduction in cement influence was confirmed from the study result. (author)

  3. Responsiveness of culture-based segmentation of organizational buyers

    Directory of Open Access Journals (Sweden)

    Veronika Jadczaková

    2013-01-01

    Full Text Available Much published work over the four decades has acknowledged market segmentation in business-to-business settings yet primarily focusing on observable segmentation bases such as firmographics or geographics. However, such bases were proved to have a weak predictive validity with respect to industrial buying behavior. Therefore, this paper attempts to add a debate to this topic by introducing new (unobservable segmentation base incorporating several facets of business culture, denoted as psychographics. The justification for this approach is that the business culture captures the collective mindset of an organization and thus enables marketers to target the organization as a whole. Given the hypothesis that culture has a merit for micro-segmentation a sample of 278 manufacturing firms was first subjected to principal component analysis and Varimax to reveal underlying cultural traits. In next step, cluster analysis was performed on retained factors to construct business profiles. Finally, non-parametric one-way analysis of variance confirmed discriminative power between profiles based on psychographics in terms of industrial buying behavior. Owing to this, business culture may assist marketers when targeting more effectively than some traditional approaches.

  4. SEMANTIC SEGMENTATION OF BUILDING ELEMENTS USING POINT CLOUD HASHING

    Directory of Open Access Journals (Sweden)

    M. Chizhova

    2018-05-01

    Full Text Available For the interpretation of point clouds, the semantic definition of extracted segments from point clouds or images is a common problem. Usually, the semantic of geometrical pre-segmented point cloud elements are determined using probabilistic networks and scene databases. The proposed semantic segmentation method is based on the psychological human interpretation of geometric objects, especially on fundamental rules of primary comprehension. Starting from these rules the buildings could be quite well and simply classified by a human operator (e.g. architect into different building types and structural elements (dome, nave, transept etc., including particular building parts which are visually detected. The key part of the procedure is a novel method based on hashing where point cloud projections are transformed into binary pixel representations. A segmentation approach released on the example of classical Orthodox churches is suitable for other buildings and objects characterized through a particular typology in its construction (e.g. industrial objects in standardized enviroments with strict component design allowing clear semantic modelling.

  5. Remote Sensing Image Registration with Line Segments and Their Intersections

    Directory of Open Access Journals (Sweden)

    Chengjin Lyu

    2017-05-01

    Full Text Available Image registration is a basic but essential step for remote sensing image processing, and finding stable features in multitemporal images is one of the most considerable challenges in the field. The main shape contours of artificial objects (e.g., roads, buildings, farmlands, and airports can be generally described as a group of line segments, which are stable features, even in images with evident background changes (e.g., images taken before and after a disaster. In this study, a registration method that uses line segments and their intersections is proposed for multitemporal remote sensing images. First, line segments are extracted in image pyramids to unify the scales of the reference image and the test image. Then, a line descriptor based on the gradient distribution of local areas is constructed, and the segments are matched in image pyramids. Lastly, triplets of intersections of matching lines are selected to estimate affine transformation between two images. Additional corresponding intersections are provided based on the estimated transformation, and an iterative process is adopted to remove outliers. The performance of the proposed method is tested on a variety of optical remote sensing image pairs, including synthetic and real data. Compared with existing methods, our method can provide more accurate registration results, even in images with significant background changes.

  6. CT image segmentation methods for bone used in medical additive manufacturing.

    Science.gov (United States)

    van Eijnatten, Maureen; van Dijk, Roelof; Dobbe, Johannes; Streekstra, Geert; Koivisto, Juha; Wolff, Jan

    2018-01-01

    The accuracy of additive manufactured medical constructs is limited by errors introduced during image segmentation. The aim of this study was to review the existing literature on different image segmentation methods used in medical additive manufacturing. Thirty-two publications that reported on the accuracy of bone segmentation based on computed tomography images were identified using PubMed, ScienceDirect, Scopus, and Google Scholar. The advantages and disadvantages of the different segmentation methods used in these studies were evaluated and reported accuracies were compared. The spread between the reported accuracies was large (0.04 mm - 1.9 mm). Global thresholding was the most commonly used segmentation method with accuracies under 0.6 mm. The disadvantage of this method is the extensive manual post-processing required. Advanced thresholding methods could improve the accuracy to under 0.38 mm. However, such methods are currently not included in commercial software packages. Statistical shape model methods resulted in accuracies from 0.25 mm to 1.9 mm but are only suitable for anatomical structures with moderate anatomical variations. Thresholding remains the most widely used segmentation method in medical additive manufacturing. To improve the accuracy and reduce the costs of patient-specific additive manufactured constructs, more advanced segmentation methods are required. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

  7. Constructing a Sophistication Index as a Method of Market ...

    African Journals Online (AJOL)

    This study investigates the process of index construction as a means of measuring a hypothetical construct that can typically not be measured by a single question or item and applying it as a method of market segmentation. The availability of incidental secondary data provided a relevant quantitative basis to illustrate this ...

  8. Weakly supervised semantic segmentation using fore-background priors

    Science.gov (United States)

    Han, Zheng; Xiao, Zhitao; Yu, Mingjun

    2017-07-01

    Weakly-supervised semantic segmentation is a challenge in the field of computer vision. Most previous works utilize the labels of the whole training set and thereby need the construction of a relationship graph about image labels, thus result in expensive computation. In this study, we tackle this problem from a different perspective. We proposed a novel semantic segmentation algorithm based on background priors, which avoids the construction of a huge graph in whole training dataset. Specifically, a random forest classifier is obtained using weakly supervised training data .Then semantic texton forest (STF) feature is extracted from image superpixels. Finally, a CRF based optimization algorithm is proposed. The unary potential of CRF derived from the outputting probability of random forest classifier and the robust saliency map as background prior. Experiments on the MSRC21 dataset show that the new algorithm outperforms some previous influential weakly-supervised segmentation algorithms. Furthermore, the use of efficient decision forests classifier and parallel computing of saliency map significantly accelerates the implementation.

  9. Robust generative asymmetric GMM for brain MR image segmentation.

    Science.gov (United States)

    Ji, Zexuan; Xia, Yong; Zheng, Yuhui

    2017-11-01

    Accurate segmentation of brain tissues from magnetic resonance (MR) images based on the unsupervised statistical models such as Gaussian mixture model (GMM) has been widely studied during last decades. However, most GMM based segmentation methods suffer from limited accuracy due to the influences of noise and intensity inhomogeneity in brain MR images. To further improve the accuracy for brain MR image segmentation, this paper presents a Robust Generative Asymmetric GMM (RGAGMM) for simultaneous brain MR image segmentation and intensity inhomogeneity correction. First, we develop an asymmetric distribution to fit the data shapes, and thus construct a spatial constrained asymmetric model. Then, we incorporate two pseudo-likelihood quantities and bias field estimation into the model's log-likelihood, aiming to exploit the neighboring priors of within-cluster and between-cluster and to alleviate the impact of intensity inhomogeneity, respectively. Finally, an expectation maximization algorithm is derived to iteratively maximize the approximation of the data log-likelihood function to overcome the intensity inhomogeneity in the image and segment the brain MR images simultaneously. To demonstrate the performances of the proposed algorithm, we first applied the proposed algorithm to a synthetic brain MR image to show the intermediate illustrations and the estimated distribution of the proposed algorithm. The next group of experiments is carried out in clinical 3T-weighted brain MR images which contain quite serious intensity inhomogeneity and noise. Then we quantitatively compare our algorithm to state-of-the-art segmentation approaches by using Dice coefficient (DC) on benchmark images obtained from IBSR and BrainWeb with different level of noise and intensity inhomogeneity. The comparison results on various brain MR images demonstrate the superior performances of the proposed algorithm in dealing with the noise and intensity inhomogeneity. In this paper, the RGAGMM

  10. Automatic segmentation of vertebrae from radiographs

    DEFF Research Database (Denmark)

    Mysling, Peter; Petersen, Peter Kersten; Nielsen, Mads

    2011-01-01

    Segmentation of vertebral contours is an essential task in the design of automatic tools for vertebral fracture assessment. In this paper, we propose a novel segmentation technique which does not require operator interaction. The proposed technique solves the segmentation problem in a hierarchical...... is constrained by a conditional shape model, based on the variability of the coarse spine location estimates. The technique is evaluated on a data set of manually annotated lumbar radiographs. The results compare favorably to the previous work in automatic vertebra segmentation, in terms of both segmentation...

  11. Color image Segmentation using automatic thresholding techniques

    International Nuclear Information System (INIS)

    Harrabi, R.; Ben Braiek, E.

    2011-01-01

    In this paper, entropy and between-class variance based thresholding methods for color images segmentation are studied. The maximization of the between-class variance (MVI) and the entropy (ME) have been used as a criterion functions to determine an optimal threshold to segment images into nearly homogenous regions. Segmentation results from the two methods are validated and the segmentation sensitivity for the test data available is evaluated, and a comparative study between these methods in different color spaces is presented. The experimental results demonstrate the superiority of the MVI method for color image segmentation.

  12. MOVING WINDOW SEGMENTATION FRAMEWORK FOR POINT CLOUDS

    Directory of Open Access Journals (Sweden)

    G. Sithole

    2012-07-01

    Full Text Available As lidar point clouds become larger streamed processing becomes more attractive. This paper presents a framework for the streamed segmentation of point clouds with the intention of segmenting unstructured point clouds in real-time. The framework is composed of two main components. The first component segments points within a window shifting over the point cloud. The second component stitches the segments within the windows together. In this fashion a point cloud can be streamed through these two components in sequence, thus producing a segmentation. The algorithm has been tested on airborne lidar point cloud and some results of the performance of the framework are presented.

  13. Unsupervised Performance Evaluation of Image Segmentation

    Directory of Open Access Journals (Sweden)

    Chabrier Sebastien

    2006-01-01

    Full Text Available We present in this paper a study of unsupervised evaluation criteria that enable the quantification of the quality of an image segmentation result. These evaluation criteria compute some statistics for each region or class in a segmentation result. Such an evaluation criterion can be useful for different applications: the comparison of segmentation results, the automatic choice of the best fitted parameters of a segmentation method for a given image, or the definition of new segmentation methods by optimization. We first present the state of art of unsupervised evaluation, and then, we compare six unsupervised evaluation criteria. For this comparative study, we use a database composed of 8400 synthetic gray-level images segmented in four different ways. Vinet's measure (correct classification rate is used as an objective criterion to compare the behavior of the different criteria. Finally, we present the experimental results on the segmentation evaluation of a few gray-level natural images.

  14. Efficient graph-cut tattoo segmentation

    Science.gov (United States)

    Kim, Joonsoo; Parra, Albert; Li, He; Delp, Edward J.

    2015-03-01

    Law enforcement is interested in exploiting tattoos as an information source to identify, track and prevent gang-related crimes. Many tattoo image retrieval systems have been described. In a retrieval system tattoo segmentation is an important step for retrieval accuracy since segmentation removes background information in a tattoo image. Existing segmentation methods do not extract the tattoo very well when the background includes textures and color similar to skin tones. In this paper we describe a tattoo segmentation approach by determining skin pixels in regions near the tattoo. In these regions graph-cut segmentation using a skin color model and a visual saliency map is used to find skin pixels. After segmentation we determine which set of skin pixels are connected with each other that form a closed contour including a tattoo. The regions surrounded by the closed contours are considered tattoo regions. Our method segments tattoos well when the background includes textures and color similar to skin.

  15. Metric Learning for Hyperspectral Image Segmentation

    Science.gov (United States)

    Bue, Brian D.; Thompson, David R.; Gilmore, Martha S.; Castano, Rebecca

    2011-01-01

    We present a metric learning approach to improve the performance of unsupervised hyperspectral image segmentation. Unsupervised spatial segmentation can assist both user visualization and automatic recognition of surface features. Analysts can use spatially-continuous segments to decrease noise levels and/or localize feature boundaries. However, existing segmentation methods use tasks-agnostic measures of similarity. Here we learn task-specific similarity measures from training data, improving segment fidelity to classes of interest. Multiclass Linear Discriminate Analysis produces a linear transform that optimally separates a labeled set of training classes. The defines a distance metric that generalized to a new scenes, enabling graph-based segmentation that emphasizes key spectral features. We describe tests based on data from the Compact Reconnaissance Imaging Spectrometer (CRISM) in which learned metrics improve segment homogeneity with respect to mineralogical classes.

  16. Interferon Induced Focal Segmental Glomerulosclerosis

    Directory of Open Access Journals (Sweden)

    Yusuf Kayar

    2016-01-01

    Full Text Available Behçet’s disease is an inflammatory disease of unknown etiology which involves recurring oral and genital aphthous ulcers and ocular lesions as well as articular, vascular, and nervous system involvement. Focal segmental glomerulosclerosis (FSGS is usually seen in viral infections, immune deficiency syndrome, sickle cell anemia, and hyperfiltration and secondary to interferon therapy. Here, we present a case of FSGS identified with kidney biopsy in a patient who had been diagnosed with Behçet’s disease and received interferon-alpha treatment for uveitis and presented with acute renal failure and nephrotic syndrome associated with interferon.

  17. A contrario line segment detection

    CERN Document Server

    von Gioi, Rafael Grompone

    2014-01-01

    The reliable detection of low-level image structures is an old and still challenging problem in computer vision. This?book leads a detailed tour through the LSD algorithm, a line segment detector designed to be fully automatic. Based on the a contrario framework, the algorithm works efficiently without the need of any parameter tuning. The design criteria are thoroughly explained and the algorithm's good and bad results are illustrated on real and synthetic images. The issues involved, as well as the strategies used, are common to many geometrical structure detection problems and some possible

  18. Did Globalization Lead to Segmentation?

    DEFF Research Database (Denmark)

    Di Vaio, Gianfranco; Enflo, Kerstin Sofia

    Economic historians have stressed that income convergence was a key feature of the 'OECD-club' and that globalization was among the accelerating forces of this process in the long-run. This view has however been challenged, since it suffers from an ad hoc selection of countries. In the paper......, a mixture model is applied to a sample of 64 countries to endogenously analyze the cross-country growth behavior over the period 1870-2003. Results show that growth patterns were segmented in two worldwide regimes, the first one being characterized by convergence, and the other one denoted by divergence...

  19. Segmentation of deformable organs from medical images using particle swarm optimization and nonlinear shape priors

    Science.gov (United States)

    Afifi, Ahmed; Nakaguchi, Toshiya; Tsumura, Norimichi

    2010-03-01

    In many medical applications, the automatic segmentation of deformable organs from medical images is indispensable and its accuracy is of a special interest. However, the automatic segmentation of these organs is a challenging task according to its complex shape. Moreover, the medical images usually have noise, clutter, or occlusion and considering the image information only often leads to meager image segmentation. In this paper, we propose a fully automated technique for the segmentation of deformable organs from medical images. In this technique, the segmentation is performed by fitting a nonlinear shape model with pre-segmented images. The kernel principle component analysis (KPCA) is utilized to capture the complex organs deformation and to construct the nonlinear shape model. The presegmentation is carried out by labeling each pixel according to its high level texture features extracted using the overcomplete wavelet packet decomposition. Furthermore, to guarantee an accurate fitting between the nonlinear model and the pre-segmented images, the particle swarm optimization (PSO) algorithm is employed to adapt the model parameters for the novel images. In this paper, we demonstrate the competence of proposed technique by implementing it to the liver segmentation from computed tomography (CT) scans of different patients.

  20. An Automatic Cognitive Graph-Based Segmentation for Detection of Blood Vessels in Retinal Images

    Directory of Open Access Journals (Sweden)

    Rasha Al Shehhi

    2016-01-01

    Full Text Available This paper presents a hierarchical graph-based segmentation for blood vessel detection in digital retinal images. This segmentation employs some of perceptual Gestalt principles: similarity, closure, continuity, and proximity to merge segments into coherent connected vessel-like patterns. The integration of Gestalt principles is based on object-based features (e.g., color and black top-hat (BTH morphology and context and graph-analysis algorithms (e.g., Dijkstra path. The segmentation framework consists of two main steps: preprocessing and multiscale graph-based segmentation. Preprocessing is to enhance lighting condition, due to low illumination contrast, and to construct necessary features to enhance vessel structure due to sensitivity of vessel patterns to multiscale/multiorientation structure. Graph-based segmentation is to decrease computational processing required for region of interest into most semantic objects. The segmentation was evaluated on three publicly available datasets. Experimental results show that preprocessing stage achieves better results compared to state-of-the-art enhancement methods. The performance of the proposed graph-based segmentation is found to be consistent and comparable to other existing methods, with improved capability of detecting small/thin vessels.

  1. Application of a semi-automatic cartilage segmentation method for biomechanical modeling of the knee joint.

    Science.gov (United States)

    Liukkonen, Mimmi K; Mononen, Mika E; Tanska, Petri; Saarakkala, Simo; Nieminen, Miika T; Korhonen, Rami K

    2017-10-01

    Manual segmentation of articular cartilage from knee joint 3D magnetic resonance images (MRI) is a time consuming and laborious task. Thus, automatic methods are needed for faster and reproducible segmentations. In the present study, we developed a semi-automatic segmentation method based on radial intensity profiles to generate 3D geometries of knee joint cartilage which were then used in computational biomechanical models of the knee joint. Six healthy volunteers were imaged with a 3T MRI device and their knee cartilages were segmented both manually and semi-automatically. The values of cartilage thicknesses and volumes produced by these two methods were compared. Furthermore, the influences of possible geometrical differences on cartilage stresses and strains in the knee were evaluated with finite element modeling. The semi-automatic segmentation and 3D geometry construction of one knee joint (menisci, femoral and tibial cartilages) was approximately two times faster than with manual segmentation. Differences in cartilage thicknesses, volumes, contact pressures, stresses, and strains between segmentation methods in femoral and tibial cartilage were mostly insignificant (p > 0.05) and random, i.e. there were no systematic differences between the methods. In conclusion, the devised semi-automatic segmentation method is a quick and accurate way to determine cartilage geometries; it may become a valuable tool for biomechanical modeling applications with large patient groups.

  2. Realization of Chinese word segmentation based on deep learning method

    Science.gov (United States)

    Wang, Xuefei; Wang, Mingjiang; Zhang, Qiquan

    2017-08-01

    In recent years, with the rapid development of deep learning, it has been widely used in the field of natural language processing. In this paper, I use the method of deep learning to achieve Chinese word segmentation, with large-scale corpus, eliminating the need to construct additional manual characteristics. In the process of Chinese word segmentation, the first step is to deal with the corpus, use word2vec to get word embedding of the corpus, each character is 50. After the word is embedded, the word embedding feature is fed to the bidirectional LSTM, add a linear layer to the hidden layer of the output, and then add a CRF to get the model implemented in this paper. Experimental results show that the method used in the 2014 People's Daily corpus to achieve a satisfactory accuracy.

  3. A Novel Plant Root Foraging Algorithm for Image Segmentation Problems

    Directory of Open Access Journals (Sweden)

    Lianbo Ma

    2014-01-01

    Full Text Available This paper presents a new type of biologically-inspired global optimization methodology for image segmentation based on plant root foraging behavior, namely, artificial root foraging algorithm (ARFO. The essential motive of ARFO is to imitate the significant characteristics of plant root foraging behavior including branching, regrowing, and tropisms for constructing a heuristic algorithm for multidimensional and multimodal problems. A mathematical model is firstly designed to abstract various plant root foraging patterns. Then, the basic process of ARFO algorithm derived in the model is described in details. When tested against ten benchmark functions, ARFO shows the superiority to other state-of-the-art algorithms on several benchmark functions. Further, we employed the ARFO algorithm to deal with multilevel threshold image segmentation problem. Experimental results of the new algorithm on a variety of images demonstrated the suitability of the proposed method for solving such problem.

  4. Automated method for structural segmentation of nasal airways based on cone beam computed tomography

    Science.gov (United States)

    Tymkovych, Maksym Yu.; Avrunin, Oleg G.; Paliy, Victor G.; Filzow, Maksim; Gryshkov, Oleksandr; Glasmacher, Birgit; Omiotek, Zbigniew; DzierŻak, RóŻa; Smailova, Saule; Kozbekova, Ainur

    2017-08-01

    The work is dedicated to the segmentation problem of human nasal airways using Cone Beam Computed Tomography. During research, we propose a specialized approach of structured segmentation of nasal airways. That approach use spatial information, symmetrisation of the structures. The proposed stages can be used for construction a virtual three dimensional model of nasal airways and for production full-scale personalized atlases. During research we build the virtual model of nasal airways, which can be used for construction specialized medical atlases and aerodynamics researches.

  5. Automating the segmentation of medical images for the production of voxel tomographic computational models

    International Nuclear Information System (INIS)

    Caon, M.

    2001-01-01

    Radiation dosimetry for the diagnostic medical imaging procedures performed on humans requires anatomically accurate, computational models. These may be constructed from medical images as voxel-based tomographic models. However, they are time consuming to produce and as a consequence, there are few available. This paper discusses the emergence of semi-automatic segmentation techniques and describes an application (iRAD) written in Microsoft Visual Basic that allows the bitmap of a medical image to be segmented interactively and semi-automatically while displayed in Microsoft Excel. iRAD will decrease the time required to construct voxel models. Copyright (2001) Australasian College of Physical Scientists and Engineers in Medicine

  6. Pathogenesis of Focal Segmental Glomerulosclerosis

    Directory of Open Access Journals (Sweden)

    Beom Jin Lim

    2016-11-01

    Full Text Available Focal segmental glomerulosclerosis (FSGS is characterized by focal and segmental obliteration of glomerular capillary tufts with increased matrix. FSGS is classified as collapsing, tip, cellular, perihilar and not otherwise specified variants according to the location and character of the sclerotic lesion. Primary or idiopathic FSGS is considered to be related to podocyte injury, and the pathogenesis of podocyte injury has been actively investigated. Several circulating factors affecting podocyte permeability barrier have been proposed, but not proven to cause FSGS. FSGS may also be caused by genetic alterations. These genes are mainly those regulating slit diaphragm structure, actin cytoskeleton of podocytes, and foot process structure. The mode of inheritance and age of onset are different according to the gene involved. Recently, the role of parietal epithelial cells (PECs has been highlighted. Podocytes and PECs have common mesenchymal progenitors, therefore, PECs could be a source of podocyte repopulation after podocyte injury. Activated PECs migrate along adhesion to the glomerular tuft and may also contribute to the progression of sclerosis. Markers of activated PECs, including CD44, could be used to distinguish FSGS from minimal change disease. The pathogenesis of FSGS is very complex; however, understanding basic mechanisms of podocyte injury is important not only for basic research, but also for daily diagnostic pathology practice.

  7. Segmented phantoms reconstruction for skin dosimetry

    International Nuclear Information System (INIS)

    Antunes, Paula C.G.; Siqueira, Paulo T.D.; Yoriyaz, Helio; Fonseca, Gabriel P.; Furnari, Laura; Reis, Gabriela S.

    2009-01-01

    There are several radio-sensitive skin diseases. Skin dosimetry is a difficult task to be properly performed, not only due to skin extension and small thickness, but also because it is usually submitted to high dose gradients. High-resolution medical images along with methods that simulate the interaction of radiation with matter, as the Monte Carlo radiation transport codes, have been widely used in medical physics procedures. These images provide the construction of realistic computational anatomical models, which after being coupled to these codes, retrieve reliable dosimetric assessments. However, present day regular images are unsuitable to correctly perform skin dose distribution evaluations. This inability is due to improper skin discrimination in most of current medical images, once its thickness stands below image resolution, i.e. pixel characteristic sizes are larger than skin thickness. This paper proposes a methodology of voxelized phantom reconstruction and segmentation, by subdividing their basic elements - voxels. It is done in order to better discriminate the skin by assigning more adequate value for skin thickness and its actual localization. Aiming at a more realistic skin modeling one is expected to get more accurate skin dose evaluations. This task is an important issue in many radiotherapy procedures. A particular interest lays in Total Skin Electron Therapy (TSET), which highlights the treatment of the whole body irradiation, a radiotherapy procedure under implementation in the Hospital das Clinicas da Universidade de Sao Paulo (HC-USP). (author)

  8. Hyperspectral image segmentation using a cooperative nonparametric approach

    Science.gov (United States)

    Taher, Akar; Chehdi, Kacem; Cariou, Claude

    2013-10-01

    In this paper a new unsupervised nonparametric cooperative and adaptive hyperspectral image segmentation approach is presented. The hyperspectral images are partitioned band by band in parallel and intermediate classification results are evaluated and fused, to get the final segmentation result. Two unsupervised nonparametric segmentation methods are used in parallel cooperation, namely the Fuzzy C-means (FCM) method, and the Linde-Buzo-Gray (LBG) algorithm, to segment each band of the image. The originality of the approach relies firstly on its local adaptation to the type of regions in an image (textured, non-textured), and secondly on the introduction of several levels of evaluation and validation of intermediate segmentation results before obtaining the final partitioning of the image. For the management of similar or conflicting results issued from the two classification methods, we gradually introduced various assessment steps that exploit the information of each spectral band and its adjacent bands, and finally the information of all the spectral bands. In our approach, the detected textured and non-textured regions are treated separately from feature extraction step, up to the final classification results. This approach was first evaluated on a large number of monocomponent images constructed from the Brodatz album. Then it was evaluated on two real applications using a respectively multispectral image for Cedar trees detection in the region of Baabdat (Lebanon) and a hyperspectral image for identification of invasive and non invasive vegetation in the region of Cieza (Spain). A correct classification rate (CCR) for the first application is over 97% and for the second application the average correct classification rate (ACCR) is over 99%.

  9. Brain Tumor Image Segmentation in MRI Image

    Science.gov (United States)

    Peni Agustin Tjahyaningtijas, Hapsari

    2018-04-01

    Brain tumor segmentation plays an important role in medical image processing. Treatment of patients with brain tumors is highly dependent on early detection of these tumors. Early detection of brain tumors will improve the patient’s life chances. Diagnosis of brain tumors by experts usually use a manual segmentation that is difficult and time consuming because of the necessary automatic segmentation. Nowadays automatic segmentation is very populer and can be a solution to the problem of tumor brain segmentation with better performance. The purpose of this paper is to provide a review of MRI-based brain tumor segmentation methods. There are number of existing review papers, focusing on traditional methods for MRI-based brain tumor image segmentation. this paper, we focus on the recent trend of automatic segmentation in this field. First, an introduction to brain tumors and methods for brain tumor segmentation is given. Then, the state-of-the-art algorithms with a focus on recent trend of full automatic segmentaion are discussed. Finally, an assessment of the current state is presented and future developments to standardize MRI-based brain tumor segmentation methods into daily clinical routine are addressed.

  10. A new framework for interactive images segmentation

    International Nuclear Information System (INIS)

    Ashraf, M.; Sarim, M.; Shaikh, A.B.

    2017-01-01

    Image segmentation has become a widely studied research problem in image processing. There exist different graph based solutions for interactive image segmentation but the domain of image segmentation still needs persistent improvements. The segmentation quality of existing techniques generally depends on the manual input provided in beginning, therefore, these algorithms may not produce quality segmentation with initial seed labels provided by a novice user. In this work we investigated the use of cellular automata in image segmentation and proposed a new algorithm that follows a cellular automaton in label propagation. It incorporates both the pixel's local and global information in the segmentation process. We introduced the novel global constraints in automata evolution rules; hence proposed scheme of automata evolution is more effective than the automata based earlier evolution schemes. Global constraints are also effective in deceasing the sensitivity towards small changes made in manual input; therefore proposed approach is less dependent on label seed marks. It can produce the quality segmentation with modest user efforts. Segmentation results indicate that the proposed algorithm performs better than the earlier segmentation techniques. (author)

  11. Space construction system analysis. Part 2: Cost and programmatics

    Science.gov (United States)

    Vonflue, F. W.; Cooper, W.

    1980-01-01

    Cost and programmatic elements of the space construction systems analysis study are discussed. The programmatic aspects of the ETVP program define a comprehensive plan for the development of a space platform, the construction system, and the space shuttle operations/logistics requirements. The cost analysis identified significant items of cost on ETVP development, ground, and flight segments, and detailed the items of space construction equipment and operations.

  12. Estimating the concentration of gold nanoparticles incorporated on natural rubber membranes using multi-level starlet optimal segmentation

    Energy Technology Data Exchange (ETDEWEB)

    Siqueira, A. F. de, E-mail: siqueiraaf@gmail.com; Cabrera, F. C., E-mail: flavioccabrera@yahoo.com.br [UNESP – Univ Estadual Paulista, Dep de Física, Química e Biologia (Brazil); Pagamisse, A., E-mail: aylton@fct.unesp.br [UNESP – Univ Estadual Paulista, Dep de Matemática e Computação (Brazil); Job, A. E., E-mail: job@fct.unesp.br [UNESP – Univ Estadual Paulista, Dep de Física, Química e Biologia (Brazil)

    2014-12-15

    This study consolidates multi-level starlet segmentation (MLSS) and multi-level starlet optimal segmentation (MLSOS) techniques for photomicrograph segmentation, based on starlet wavelet detail levels to separate areas of interest in an input image. Several segmentation levels can be obtained using MLSS; after that, Matthews correlation coefficient is used to choose an optimal segmentation level, giving rise to MLSOS. In this paper, MLSOS is employed to estimate the concentration of gold nanoparticles with diameter around 47  nm, reduced on natural rubber membranes. These samples were used for the construction of SERS/SERRS substrates and in the study of the influence of natural rubber membranes with incorporated gold nanoparticles on the physiology of Leishmania braziliensis. Precision, recall, and accuracy are used to evaluate the segmentation performance, and MLSOS presents an accuracy greater than 88 % for this application.

  13. Level set method for image segmentation based on moment competition

    Science.gov (United States)

    Min, Hai; Wang, Xiao-Feng; Huang, De-Shuang; Jin, Jing; Wang, Hong-Zhi; Li, Hai

    2015-05-01

    We propose a level set method for image segmentation which introduces the moment competition and weakly supervised information into the energy functional construction. Different from the region-based level set methods which use force competition, the moment competition is adopted to drive the contour evolution. Here, a so-called three-point labeling scheme is proposed to manually label three independent points (weakly supervised information) on the image. Then the intensity differences between the three points and the unlabeled pixels are used to construct the force arms for each image pixel. The corresponding force is generated from the global statistical information of a region-based method and weighted by the force arm. As a result, the moment can be constructed and incorporated into the energy functional to drive the evolving contour to approach the object boundary. In our method, the force arm can take full advantage of the three-point labeling scheme to constrain the moment competition. Additionally, the global statistical information and weakly supervised information are successfully integrated, which makes the proposed method more robust than traditional methods for initial contour placement and parameter setting. Experimental results with performance analysis also show the superiority of the proposed method on segmenting different types of complicated images, such as noisy images, three-phase images, images with intensity inhomogeneity, and texture images.

  14. Hierarchical image segmentation for learning object priors

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, Lakshman [Los Alamos National Laboratory; Yang, Xingwei [TEMPLE UNIV.; Latecki, Longin J [TEMPLE UNIV.; Li, Nan [TEMPLE UNIV.

    2010-11-10

    The proposed segmentation approach naturally combines experience based and image based information. The experience based information is obtained by training a classifier for each object class. For a given test image, the result of each classifier is represented as a probability map. The final segmentation is obtained with a hierarchial image segmentation algorithm that considers both the probability maps and the image features such as color and edge strength. We also utilize image region hierarchy to obtain not only local but also semi-global features as input to the classifiers. Moreover, to get robust probability maps, we take into account the region context information by averaging the probability maps over different levels of the hierarchical segmentation algorithm. The obtained segmentation results are superior to the state-of-the-art supervised image segmentation algorithms.

  15. Image Segmentation Using Minimum Spanning Tree

    Science.gov (United States)

    Dewi, M. P.; Armiati, A.; Alvini, S.

    2018-04-01

    This research aim to segmented the digital image. The process of segmentation is to separate the object from the background. So the main object can be processed for the other purposes. Along with the development of technology in digital image processing application, the segmentation process becomes increasingly necessary. The segmented image which is the result of the segmentation process should accurate due to the next process need the interpretation of the information on the image. This article discussed the application of minimum spanning tree on graph in segmentation process of digital image. This method is able to separate an object from the background and the image will change to be the binary images. In this case, the object that being the focus is set in white, while the background is black or otherwise.

  16. Toxic Anterior Segment Syndrome (TASS

    Directory of Open Access Journals (Sweden)

    Özlem Öner

    2011-12-01

    Full Text Available Toxic anterior segment syndrome (TASS is a sterile intraocular inflammation caused by noninfectious substances, resulting in extensive toxic damage to the intraocular tissues. Possible etiologic factors of TASS include surgical trauma, bacterial endotoxin, intraocular solutions with inappropriate pH and osmolality, preservatives, denatured ophthalmic viscosurgical devices (OVD, inadequate sterilization, cleaning and rinsing of surgical devices, intraocular lenses, polishing and sterilizing compounds which are related to intraocular lenses. The characteristic signs and symptoms such as blurred vision, corneal edema, hypopyon and nonreactive pupil usually occur 24 hours after the cataract surgery. The differential diagnosis of TASS from infectious endophthalmitis is important. The main treatment for TASS formation is prevention. TASS is a cataract surgery complication that is more commonly seen nowadays. In this article, the possible underlying causes as well as treatment and prevention methods of TASS are summarized. (Turk J Oph thal mol 2011; 41: 407-13

  17. A construction process model for implementing constructability in construction

    NARCIS (Netherlands)

    Langkemper, J.; Al-Jibouri, S.; Reymen, I.M.M.J.; Maas, G.J.; Gassel, van F.

    2003-01-01

    In construction, failure of design professionals to consider how a builder will implement the design can result in scheduling problems, cost escalation, delays and disputes during the construction process. The integration of construction knowledge and experience during planning and design is termed

  18. Communication with market segments - travel agencies' perspective

    OpenAIRE

    Lorena Bašan; Jasmina Dlačić; Željko Trezner

    2013-01-01

    Purpose – The purpose of this paper is to research the travel agencies’ communication with market segments. Communication with market segments takes into account marketing communication means as well as the implementation of different business orientations. Design – Special emphasis is placed on the use of different marketing communication means and their efficiency. Research also explores business orientation adaptation when approaching different market segments. Methodology – In explo...

  19. Distance measures for image segmentation evaluation

    OpenAIRE

    Monteiro, Fernando C.; Campilho, Aurélio

    2012-01-01

    In this paper we present a study of evaluation measures that enable the quantification of the quality of an image segmentation result. Despite significant advances in image segmentation techniques, evaluation of these techniques thus far has been largely subjective. Typically, the effectiveness of a new algorithm is demonstrated only by the presentation of a few segmented images and is otherwise left to subjective evaluation by the reader. Such an evaluation criterion can be useful for differ...

  20. IFRS 8 Operating Segments - A Closer Look

    OpenAIRE

    Muthupandian, K S

    2008-01-01

    The International Accounting Standards Board issued the International Financial Reporting Standard 8 Operating Segments. Segment information is one of the most vital aspects of financial reporting for investors and other users. The IFRS 8 requires an entity to adopt the ‘management approach’ to reporting on the financial performance of its operating segments. This article presents a closer look of the standard (objective, scope, and disclosures).

  1. MRI Brain Tumor Segmentation Methods- A Review

    OpenAIRE

    Gursangeet, Kaur; Jyoti, Rani

    2016-01-01

    Medical image processing and its segmentation is an active and interesting area for researchers. It has reached at the tremendous place in diagnosing tumors after the discovery of CT and MRI. MRI is an useful tool to detect the brain tumor and segmentation is performed to carry out the useful portion from an image. The purpose of this paper is to provide an overview of different image segmentation methods like watershed algorithm, morphological operations, neutrosophic sets, thresholding, K-...

  2. Speaker Segmentation and Clustering Using Gender Information

    Science.gov (United States)

    2006-02-01

    used in the first stages of segmentation forder information in the clustering of the opposite-gender speaker diarization of news broadcasts. files, the...AFRL-HE-WP-TP-2006-0026 AIR FORCE RESEARCH LABORATORY Speaker Segmentation and Clustering Using Gender Information Brian M. Ore General Dynamics...COVERED (From - To) February 2006 ProceedinLgs 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Speaker Segmentation and Clustering Using Gender Information 5b

  3. Benchmarking of Remote Sensing Segmentation Methods

    Czech Academy of Sciences Publication Activity Database

    Mikeš, Stanislav; Haindl, Michal; Scarpa, G.; Gaetano, R.

    2015-01-01

    Roč. 8, č. 5 (2015), s. 2240-2248 ISSN 1939-1404 R&D Projects: GA ČR(CZ) GA14-10911S Institutional support: RVO:67985556 Keywords : benchmark * remote sensing segmentation * unsupervised segmentation * supervised segmentation Subject RIV: BD - Theory of Information Impact factor: 2.145, year: 2015 http://library.utia.cas.cz/separaty/2015/RO/haindl-0445995.pdf

  4. Performance of a highly segmented scintillating fibres electromagnetic calorimeter

    International Nuclear Information System (INIS)

    Asmone, A.; Bertino, M.; Bini, C.; De Zorzi, G.; Diambrini Palazzi, G.; Di Cosimo, G.; Di Domenico, A.; Garufi, F.; Gauzzi, P.; Zanello, D.

    1993-01-01

    A prototype of scintillating fibres electromagnetic calorimeter has been constructed and tested with 2, 4 and 8 GeV electron beams at the CERN PS. The calorimeter modules consist of a Bi-Pb-Sn alloy and scintillating fibres. The fibres are parallel to the modules longer axis, and nearly parallel to the incident electrons direction. The calorimeter has two different segmentation regions of 24x24 mm 2 and 8x24 mm 2 cross area respectively. Results on energy and impact point space resolution are obtained and compared for the two different granularities. (orig.)

  5. 3D variational brain tumor segmentation using Dirichlet priors on a clustered feature set.

    Science.gov (United States)

    Popuri, Karteek; Cobzas, Dana; Murtha, Albert; Jägersand, Martin

    2012-07-01

    Brain tumor segmentation is a required step before any radiation treatment or surgery. When performed manually, segmentation is time consuming and prone to human errors. Therefore, there have been significant efforts to automate the process. But, automatic tumor segmentation from MRI data is a particularly challenging task. Tumors have a large diversity in shape and appearance with intensities overlapping the normal brain tissues. In addition, an expanding tumor can also deflect and deform nearby tissue. In our work, we propose an automatic brain tumor segmentation method that addresses these last two difficult problems. We use the available MRI modalities (T1, T1c, T2) and their texture characteristics to construct a multidimensional feature set. Then, we extract clusters which provide a compact representation of the essential information in these features. The main idea in this work is to incorporate these clustered features into the 3D variational segmentation framework. In contrast to previous variational approaches, we propose a segmentation method that evolves the contour in a supervised fashion. The segmentation boundary is driven by the learned region statistics in the cluster space. We incorporate prior knowledge about the normal brain tissue appearance during the estimation of these region statistics. In particular, we use a Dirichlet prior that discourages the clusters from the normal brain region to be in the tumor region. This leads to a better disambiguation of the tumor from brain tissue. We evaluated the performance of our automatic segmentation method on 15 real MRI scans of brain tumor patients, with tumors that are inhomogeneous in appearance, small in size and in proximity to the major structures in the brain. Validation with the expert segmentation labels yielded encouraging results: Jaccard (58%), Precision (81%), Recall (67%), Hausdorff distance (24 mm). Using priors on the brain/tumor appearance, our proposed automatic 3D variational

  6. Track segment synthesis method for NTA film

    International Nuclear Information System (INIS)

    Kumazawa, Shigeru

    1980-03-01

    A method is presented for synthesizing track segments extracted from a gray-level digital picture of NTA film in automatic counting system. In order to detect each track in an arbitrary direction, even if it has some gaps, as a set of the track segments, the method links extracted segments along the track, in succession, to the linked track segments, according to whether each extracted segment bears a similarity of direction to the track or not and whether it is connected with the linked track segments or not. In the case of a large digital picture, the method is applied to each subpicture, which is a strip of the picture, and then concatenates subsets of track segments linked at each subpicture as a set of track segments belonging to a track. The method was applied to detecting tracks in various directions over the eight 364 x 40-pixel subpictures with the gray scale of 127/pixel (picture element) of the microphotograph of NTA film. It was proved to be able to synthesize track segments correctly for every track in the picture. (author)

  7. Segmenting hospitals for improved management strategy.

    Science.gov (United States)

    Malhotra, N K

    1989-09-01

    The author presents a conceptual framework for the a priori and clustering-based approaches to segmentation and evaluates them in the context of segmenting institutional health care markets. An empirical study is reported in which the hospital market is segmented on three state-of-being variables. The segmentation approach also takes into account important organizational decision-making variables. The sophisticated Thurstone Case V procedure is employed. Several marketing implications for hospitals, other health care organizations, hospital suppliers, and donor publics are identified.

  8. Prototype implementation of segment assembling software

    Directory of Open Access Journals (Sweden)

    Pešić Đorđe

    2018-01-01

    Full Text Available IT education is very important and a lot of effort is put into the development of tools for helping students to acquire programming knowledge and for helping teachers in automating the examination process. This paper describes a prototype of the program segment assembling software used in the context of making tests in the field of algorithmic complexity. The proposed new program segment assembling model uses rules and templates. A template is a simple program segment. A rule defines combining method and data dependencies if they exist. One example of program segment assembling by the proposed system is given. Graphical user interface is also described.

  9. Probabilistic Segmentation of Folk Music Recordings

    Directory of Open Access Journals (Sweden)

    Ciril Bohak

    2016-01-01

    Full Text Available The paper presents a novel method for automatic segmentation of folk music field recordings. The method is based on a distance measure that uses dynamic time warping to cope with tempo variations and a dynamic programming approach to handle pitch drifting for finding similarities and estimating the length of repeating segment. A probabilistic framework based on HMM is used to find segment boundaries, searching for optimal match between the expected segment length, between-segment similarities, and likely locations of segment beginnings. Evaluation of several current state-of-the-art approaches for segmentation of commercial music is presented and their weaknesses when dealing with folk music are exposed, such as intolerance to pitch drift and variable tempo. The proposed method is evaluated and its performance analyzed on a collection of 206 folk songs of different ensemble types: solo, two- and three-voiced, choir, instrumental, and instrumental with singing. It outperforms current commercial music segmentation methods for noninstrumental music and is on a par with the best for instrumental recordings. The method is also comparable to a more specialized method for segmentation of solo singing folk music recordings.

  10. Review of segmentation process in consumer markets

    Directory of Open Access Journals (Sweden)

    Veronika Jadczaková

    2013-01-01

    Full Text Available Although there has been a considerable debate on market segmentation over five decades, attention was merely devoted to single stages of the segmentation process. In doing so, stages as segmentation base selection or segments profiling have been heavily covered in the extant literature, whereas stages as implementation of the marketing strategy or market definition were of a comparably lower interest. Capitalizing on this shortcoming, this paper strives to close the gap and provide each step of the segmentation process with equal treatment. Hence, the objective of this paper is two-fold. First, a snapshot of the segmentation process in a step-by-step fashion will be provided. Second, each step (where possible will be evaluated on chosen criteria by means of description, comparison, analysis and synthesis of 32 academic papers and 13 commercial typology systems. Ultimately, the segmentation stages will be discussed with empirical findings prevalent in the segmentation studies and last but not least suggestions calling for further investigation will be presented. This seven-step-framework may assist when segmenting in practice allowing for more confidential targeting which in turn might prepare grounds for creating of a differential advantage.

  11. Interactive segmentation techniques algorithms and performance evaluation

    CERN Document Server

    He, Jia; Kuo, C-C Jay

    2013-01-01

    This book focuses on interactive segmentation techniques, which have been extensively studied in recent decades. Interactive segmentation emphasizes clear extraction of objects of interest, whose locations are roughly indicated by human interactions based on high level perception. This book will first introduce classic graph-cut segmentation algorithms and then discuss state-of-the-art techniques, including graph matching methods, region merging and label propagation, clustering methods, and segmentation methods based on edge detection. A comparative analysis of these methods will be provided

  12. Concept project of joining segment, connecting two folding bridge structures MS-54 and widened DMS-65

    Directory of Open Access Journals (Sweden)

    Jan Marszałek

    2015-09-01

    Full Text Available The article includes the concept project of truss segment enabling the constructions of MS-54 and DMS-65 bridges to joint. At the beginning, the basic technical and exploitative characteristics of joined constructions are introduced. On the basis of this data, geometrical analysis of the component is carried out. As a result, the concept project of fitting, enabling the crossing from two types of foldable constructions to be built, is developed. Sequentially, the computer calculations of the bridge including the part of the designed fitting are carried out.The article contains the fragments of M.A. dissertation awarded by the rector of Military University of Technology as the best from the Faculty of Civil Engineering in 2014. The article is summarized with the conclusions.[b]Keywords[/b]: construction, folding bridges, truss segment

  13. Automated segmentation of pulmonary structures in thoracic computed tomography scans: a review

    International Nuclear Information System (INIS)

    Van Rikxoort, Eva M; Van Ginneken, Bram

    2013-01-01

    Computed tomography (CT) is the modality of choice for imaging the lungs in vivo. Sub-millimeter isotropic images of the lungs can be obtained within seconds, allowing the detection of small lesions and detailed analysis of disease processes. The high resolution of thoracic CT and the high prevalence of lung diseases require a high degree of automation in the analysis pipeline. The automated segmentation of pulmonary structures in thoracic CT has been an important research topic for over a decade now. This systematic review provides an overview of current literature. We discuss segmentation methods for the lungs, the pulmonary vasculature, the airways, including airway tree construction and airway wall segmentation, the fissures, the lobes and the pulmonary segments. For each topic, the current state of the art is summarized, and topics for future research are identified. (topical review)

  14. An automatic system for segmentation, matching, anatomical labeling and measurement of airways from CT images

    DEFF Research Database (Denmark)

    Petersen, Jens; Feragen, Aasa; Owen, Megan

    segmental branches, and longitudinal matching of airway branches in repeated scans of the same subject. Methods and Materials: The segmentation process begins from an automatically detected seed point in the trachea. The airway centerline tree is then constructed by iteratively adding locally optimal paths...... differences. Results: The segmentation method has been used on 9711 low dose CT images from the Danish Lung Cancer Screening Trial (DLCST). Manual inspection of thumbnail images revealed gross errors in a total of 44 images. 29 were missing branches at the lobar level and only 15 had obvious false positives...... measurements to segments matched in multiple images of the same subject using image registration was observed to increase their reproducibility. The anatomical branch labeling tool was validated on a subset of 20 subjects, 5 of each category: asymptomatic, mild, moderate and severe COPD. The average inter...

  15. Precise Alignment and Permanent Mounting of Thin and Lightweight X-ray Segments

    Science.gov (United States)

    Biskach, Michael P.; Chan, Kai-Wing; Hong, Melinda N.; Mazzarella, James R.; McClelland, Ryan S.; Norman, Michael J.; Saha, Timo T.; Zhang, William W.

    2012-01-01

    To provide observations to support current research efforts in high energy astrophysics. future X-ray telescope designs must provide matching or better angular resolution while significantly increasing the total collecting area. In such a design the permanent mounting of thin and lightweight segments is critical to the overall performance of the complete X-ray optic assembly. The thin and lightweight segments used in the assemhly of the modules are desigued to maintain and/or exceed the resolution of existing X-ray telescopes while providing a substantial increase in collecting area. Such thin and delicate X-ray segments are easily distorted and yet must be aligned to the arcsecond level and retain accurate alignment for many years. The Next Generation X-ray Optic (NGXO) group at NASA Goddard Space Flight Center has designed, assembled. and implemented new hardware and procedures mth the short term goal of aligning three pairs of X-ray segments in a technology demonstration module while maintaining 10 arcsec alignment through environmental testing as part of the eventual design and construction of a full sized module capable of housing hundreds of X-ray segments. The recent attempts at multiple segment pair alignment and permanent mounting is described along with an overview of the procedure used. A look into what the next year mll bring for the alignment and permanent segment mounting effort illustrates some of the challenges left to overcome before an attempt to populate a full sized module can begin.

  16. Model-Based Learning of Local Image Features for Unsupervised Texture Segmentation

    Science.gov (United States)

    Kiechle, Martin; Storath, Martin; Weinmann, Andreas; Kleinsteuber, Martin

    2018-04-01

    Features that capture well the textural patterns of a certain class of images are crucial for the performance of texture segmentation methods. The manual selection of features or designing new ones can be a tedious task. Therefore, it is desirable to automatically adapt the features to a certain image or class of images. Typically, this requires a large set of training images with similar textures and ground truth segmentation. In this work, we propose a framework to learn features for texture segmentation when no such training data is available. The cost function for our learning process is constructed to match a commonly used segmentation model, the piecewise constant Mumford-Shah model. This means that the features are learned such that they provide an approximately piecewise constant feature image with a small jump set. Based on this idea, we develop a two-stage algorithm which first learns suitable convolutional features and then performs a segmentation. We note that the features can be learned from a small set of images, from a single image, or even from image patches. The proposed method achieves a competitive rank in the Prague texture segmentation benchmark, and it is effective for segmenting histological images.

  17. Localized Segment Based Processing for Automatic Building Extraction from LiDAR Data

    Science.gov (United States)

    Parida, G.; Rajan, K. S.

    2017-05-01

    The current methods of object segmentation and extraction and classification of aerial LiDAR data is manual and tedious task. This work proposes a technique for object segmentation out of LiDAR data. A bottom-up geometric rule based approach was used initially to devise a way to segment buildings out of the LiDAR datasets. For curved wall surfaces, comparison of localized surface normals was done to segment buildings. The algorithm has been applied to both synthetic datasets as well as real world dataset of Vaihingen, Germany. Preliminary results show successful segmentation of the buildings objects from a given scene in case of synthetic datasets and promissory results in case of real world data. The advantages of the proposed work is non-dependence on any other form of data required except LiDAR. It is an unsupervised method of building segmentation, thus requires no model training as seen in supervised techniques. It focuses on extracting the walls of the buildings to construct the footprint, rather than focussing on roof. The focus on extracting the wall to reconstruct the buildings from a LiDAR scene is crux of the method proposed. The current segmentation approach can be used to get 2D footprints of the buildings, with further scope to generate 3D models. Thus, the proposed method can be used as a tool to get footprints of buildings in urban landscapes, helping in urban planning and the smart cities endeavour.

  18. LOCALIZED SEGMENT BASED PROCESSING FOR AUTOMATIC BUILDING EXTRACTION FROM LiDAR DATA

    Directory of Open Access Journals (Sweden)

    G. Parida

    2017-05-01

    Full Text Available The current methods of object segmentation and extraction and classification of aerial LiDAR data is manual and tedious task. This work proposes a technique for object segmentation out of LiDAR data. A bottom-up geometric rule based approach was used initially to devise a way to segment buildings out of the LiDAR datasets. For curved wall surfaces, comparison of localized surface normals was done to segment buildings. The algorithm has been applied to both synthetic datasets as well as real world dataset of Vaihingen, Germany. Preliminary results show successful segmentation of the buildings objects from a given scene in case of synthetic datasets and promissory results in case of real world data. The advantages of the proposed work is non-dependence on any other form of data required except LiDAR. It is an unsupervised method of building segmentation, thus requires no model training as seen in supervised techniques. It focuses on extracting the walls of the buildings to construct the footprint, rather than focussing on roof. The focus on extracting the wall to reconstruct the buildings from a LiDAR scene is crux of the method proposed. The current segmentation approach can be used to get 2D footprints of the buildings, with further scope to generate 3D models. Thus, the proposed method can be used as a tool to get footprints of buildings in urban landscapes, helping in urban planning and the smart cities endeavour.

  19. Multi-atlas segmentation for abdominal organs with Gaussian mixture models

    Science.gov (United States)

    Burke, Ryan P.; Xu, Zhoubing; Lee, Christopher P.; Baucom, Rebeccah B.; Poulose, Benjamin K.; Abramson, Richard G.; Landman, Bennett A.

    2015-03-01

    Abdominal organ segmentation with clinically acquired computed tomography (CT) is drawing increasing interest in the medical imaging community. Gaussian mixture models (GMM) have been extensively used through medical segmentation, most notably in the brain for cerebrospinal fluid / gray matter / white matter differentiation. Because abdominal CT exhibit strong localized intensity characteristics, GMM have recently been incorporated in multi-stage abdominal segmentation algorithms. In the context of variable abdominal anatomy and rich algorithms, it is difficult to assess the marginal contribution of GMM. Herein, we characterize the efficacy of an a posteriori framework that integrates GMM of organ-wise intensity likelihood with spatial priors from multiple target-specific registered labels. In our study, we first manually labeled 100 CT images. Then, we assigned 40 images to use as training data for constructing target-specific spatial priors and intensity likelihoods. The remaining 60 images were evaluated as test targets for segmenting 12 abdominal organs. The overlap between the true and the automatic segmentations was measured by Dice similarity coefficient (DSC). A median improvement of 145% was achieved by integrating the GMM intensity likelihood against the specific spatial prior. The proposed framework opens the opportunities for abdominal organ segmentation by efficiently using both the spatial and appearance information from the atlases, and creates a benchmark for large-scale automatic abdominal segmentation.

  20. Medical Image Segmentation by Combining Graph Cut and Oriented Active Appearance Models

    Science.gov (United States)

    Chen, Xinjian; Udupa, Jayaram K.; Bağcı, Ulaş; Zhuge, Ying; Yao, Jianhua

    2017-01-01

    In this paper, we propose a novel 3D segmentation method based on the effective combination of the active appearance model (AAM), live wire (LW), and graph cut (GC). The proposed method consists of three main parts: model building, initialization, and segmentation. In the model building part, we construct the AAM and train the LW cost function and GC parameters. In the initialization part, a novel algorithm is proposed for improving the conventional AAM matching method, which effectively combines the AAM and LW method, resulting in Oriented AAM (OAAM). A multi-object strategy is utilized to help in object initialization. We employ a pseudo-3D initialization strategy, and segment the organs slice by slice via multi-object OAAM method. For the segmentation part, a 3D shape constrained GC method is proposed. The object shape generated from the initialization step is integrated into the GC cost computation, and an iterative GC-OAAM method is used for object delineation. The proposed method was tested in segmenting the liver, kidneys, and spleen on a clinical CT dataset and also tested on the MICCAI 2007 grand challenge for liver segmentation training dataset. The results show the following: (a) An overall segmentation accuracy of true positive volume fraction (TPVF) > 94.3%, false positive volume fraction (FPVF) wordpress.com/research/. PMID:22311862

  1. Segmentation of liver tumors on CT images

    International Nuclear Information System (INIS)

    Pescia, D.

    2011-01-01

    This thesis is dedicated to 3D segmentation of liver tumors in CT images. This is a task of great clinical interest since it allows physicians benefiting from reproducible and reliable methods for segmenting such lesions. Accurate segmentation would indeed help them during the evaluation of the lesions, the choice of treatment and treatment planning. Such a complex segmentation task should cope with three main scientific challenges: (i) the highly variable shape of the structures being sought, (ii) their similarity of appearance compared with their surrounding medium and finally (iii) the low signal to noise ratio being observed in these images. This problem is addressed in a clinical context through a two step approach, consisting of the segmentation of the entire liver envelope, before segmenting the tumors which are present within the envelope. We begin by proposing an atlas-based approach for computing pathological liver envelopes. Initially images are pre-processed to compute the envelopes that wrap around binary masks in an attempt to obtain liver envelopes from estimated segmentation of healthy liver parenchyma. A new statistical atlas is then introduced and used to segmentation through its diffeomorphic registration to the new image. This segmentation is achieved through the combination of image matching costs as well as spatial and appearance prior using a multi-scale approach with MRF. The second step of our approach is dedicated to lesions segmentation contained within the envelopes using a combination of machine learning techniques and graph based methods. First, an appropriate feature space is considered that involves texture descriptors being determined through filtering using various scales and orientations. Then, state of the art machine learning techniques are used to determine the most relevant features, as well as the hyper plane that separates the feature space of tumoral voxels to the ones corresponding to healthy tissues. Segmentation is then

  2. Modelling the factors influencing the selection of the construction equipment for Indian construction organizations

    Directory of Open Access Journals (Sweden)

    S.V.S. Raja Prasad

    2016-09-01

    Full Text Available The contribution of Indian construction sector to the GDP is approximately 10%. Under new government policy, it is anticipated that $1000 Billion share for exclusively infrastructure segment would be completed within the next few years. Construction sector in developing country like India still depends on labor and the practice of mechanization, adopting to use of versatile construction equipment is not in force. The need for implementing new technologies and automation is essential to improve the quality, safety and efficiency. To meet the challenges ahead the construction, organizations should focus on utilization of machinery/equipment to achieve desirable results. Modern construction is characterized by the increase in utilization of equipment to accomplish numerous construction activities. The selection of construction equipment often affects the required amount of time and effort. It is therefore important for managements of construction organizations and planners to be familiar with the features of various types of equipment commonly used in construction activities. The selection of appropriate equipment is a crucial decision making process as it involves huge capital investment. The purpose of the present study is to develop a model pertaining to the factors influencing the selection of construction equipment by using interpretive structural modelling and the results indicate that productivity and safety are the important factors in selection of equipment in Indian construction organizations.

  3. Segment-Tube: Spatio-Temporal Action Localization in Untrimmed Videos with Per-Frame Segmentation

    OpenAIRE

    Le Wang; Xuhuan Duan; Qilin Zhang; Zhenxing Niu; Gang Hua; Nanning Zheng

    2018-01-01

    Inspired by the recent spatio-temporal action localization efforts with tubelets (sequences of bounding boxes), we present a new spatio-temporal action localization detector Segment-tube, which consists of sequences of per-frame segmentation masks. The proposed Segment-tube detector can temporally pinpoint the starting/ending frame of each action category in the presence of preceding/subsequent interference actions in untrimmed videos. Simultaneously, the Segment-tube detector produces per-fr...

  4. Incremental and Enhanced Scanline-Based Segmentation Method for Surface Reconstruction of Sparse LiDAR Data

    Directory of Open Access Journals (Sweden)

    Weimin Wang

    2016-11-01

    Full Text Available The segmentation of point clouds is an important aspect of automated processing tasks such as semantic extraction. However, the sparsity and non-uniformity of the point clouds gathered by the popular 3D mobile LiDAR devices pose many challenges for existing segmentation methods. To improve the segmentation results of point clouds from mobile LiDAR devices, we propose an optimized segmentation method based on Scanline Continuity Constraint (SLCC in this work. Unlike conventional scanline-based segmentation methods, SLCC clusters scanlines using the continuity constraints in terms of the distance as well as the direction of two consecutive points. In addition, scanline clusters are agglomerated not only into primitive geometrical shapes but also irregular shapes. Another downside to existing segmentation methods is that they are not capable of incremental processing. This causes unnecessary memory and time consumption for applications that require frame-wise segmentation or when new point clouds are added. In order to address this, we propose an incremental scheme—the Incremental Recursive Segmentation (IRIS, that can be easily applied to any segmentation method. IRIS is achieved by combining the segments of newly added point clouds and the previously segmented results. Furthermore, as an example application, we construct a processing pipeline consisting of plane fitting and surface reconstruction using the segmentation results. Finally, we evaluate the proposed methods on three datasets acquired from a handheld Velodyne HDL-32E LiDAR device. The experimental results verify the efficiency of IRIS for any segmentation method and the advantages of SLCC for processing mobile LiDAR data.

  5. Segmenting Bone Parts for Bone Age Assessment using Point Distribution Model and Contour Modelling

    Science.gov (United States)

    Kaur, Amandeep; Singh Mann, Kulwinder, Dr.

    2018-01-01

    Bone age assessment (BAA) is a task performed on radiographs by the pediatricians in hospitals to predict the final adult height, to diagnose growth disorders by monitoring skeletal development. For building an automatic bone age assessment system the step in routine is to do image pre-processing of the bone X-rays so that features row can be constructed. In this research paper, an enhanced point distribution algorithm using contours has been implemented for segmenting bone parts as per well-established procedure of bone age assessment that would be helpful in building feature row and later on; it would be helpful in construction of automatic bone age assessment system. Implementation of the segmentation algorithm shows high degree of accuracy in terms of recall and precision in segmenting bone parts from left hand X-Rays.

  6. Mild toxic anterior segment syndrome mimicking delayed onset toxic anterior segment syndrome after cataract surgery

    Directory of Open Access Journals (Sweden)

    Su-Na Lee

    2014-01-01

    Full Text Available Toxic anterior segment syndrome (TASS is an acute sterile postoperative anterior segment inflammation that may occur after anterior segment surgery. I report herein a case that developed mild TASS in one eye after bilateral uneventful cataract surgery, which was masked during early postoperative period under steroid eye drop and mimicking delayed onset TASS after switching to weaker steroid eye drop.

  7. GeoSegmenter: A statistically learned Chinese word segmenter for the geoscience domain

    Science.gov (United States)

    Huang, Lan; Du, Youfu; Chen, Gongyang

    2015-03-01

    Unlike English, the Chinese language has no space between words. Segmenting texts into words, known as the Chinese word segmentation (CWS) problem, thus becomes a fundamental issue for processing Chinese documents and the first step in many text mining applications, including information retrieval, machine translation and knowledge acquisition. However, for the geoscience subject domain, the CWS problem remains unsolved. Although a generic segmenter can be applied to process geoscience documents, they lack the domain specific knowledge and consequently their segmentation accuracy drops dramatically. This motivated us to develop a segmenter specifically for the geoscience subject domain: the GeoSegmenter. We first proposed a generic two-step framework for domain specific CWS. Following this framework, we built GeoSegmenter using conditional random fields, a principled statistical framework for sequence learning. Specifically, GeoSegmenter first identifies general terms by using a generic baseline segmenter. Then it recognises geoscience terms by learning and applying a model that can transform the initial segmentation into the goal segmentation. Empirical experimental results on geoscience documents and benchmark datasets showed that GeoSegmenter could effectively recognise both geoscience terms and general terms.

  8. NUCLEAR SEGMENTATION IN MICROSCOPE CELL IMAGES: A HAND-SEGMENTED DATASET AND COMPARISON OF ALGORITHMS

    OpenAIRE

    Coelho, Luís Pedro; Shariff, Aabid; Murphy, Robert F.

    2009-01-01

    Image segmentation is an essential step in many image analysis pipelines and many algorithms have been proposed to solve this problem. However, they are often evaluated subjectively or based on a small number of examples. To fill this gap, we hand-segmented a set of 97 fluorescence microscopy images (a total of 4009 cells) and objectively evaluated some previously proposed segmentation algorithms.

  9. Robust shape regression for supervised vessel segmentation and its application to coronary segmentation in CTA

    DEFF Research Database (Denmark)

    Schaap, Michiel; van Walsum, Theo; Neefjes, Lisan

    2011-01-01

    This paper presents a vessel segmentation method which learns the geometry and appearance of vessels in medical images from annotated data and uses this knowledge to segment vessels in unseen images. Vessels are segmented in a coarse-to-fine fashion. First, the vessel boundaries are estimated...

  10. Limb-segment selection in drawing behaviour

    NARCIS (Netherlands)

    Meulenbroek, R G; Rosenbaum, D A; Thomassen, A.J.W.M.; Schomaker, L R

    How do we select combinations of limb segments to carry out physical tasks? Three possible determinants of limb-segment selection are hypothesized here: (1) optimal amplitudes and frequencies of motion for the effectors; (2) preferred movement axes for the effectors; and (3) a tendency to continue

  11. LIMB-SEGMENT SELECTION IN DRAWING BEHAVIOR

    NARCIS (Netherlands)

    MEULENBROEK, RGJ; ROSENBAUM, DA; THOMASSEN, AJWM; SCHOMAKER, LRB; Schomaker, Lambertus

    How do we select combinations of limb segments to carry out physical tasks? Three possible determinants of limb-segment selection are hypothesized here: (1) optimal amplitudes and frequencies of motion for the effectors; (2) preferred movement axes for the effectors; and (3) a tendency to continue

  12. Handwriting segmentation of unconstrained Oriya text

    Indian Academy of Sciences (India)

    Based on vertical projection profiles and structural features of Oriya characters, text lines are segmented into words. For character segmentation, at first, the isolated and connected (touching) characters in a word are detected. Using structural, topological and water reservoir concept-based features, characters of the word ...

  13. Segmentation precedes face categorization under suboptimal conditions

    NARCIS (Netherlands)

    Van Den Boomen, Carlijn; Fahrenfort, Johannes J; Snijders, Tineke M; Kemner, Chantal

    2015-01-01

    Both categorization and segmentation processes play a crucial role in face perception. However, the functional relation between these subprocesses is currently unclear. The present study investigates the temporal relation between segmentation-related and category-selective responses in the brain,

  14. Bayesian segmentation of brainstem structures in MRI

    DEFF Research Database (Denmark)

    Iglesias, Juan Eugenio; Van Leemput, Koen; Bhatt, Priyanka

    2015-01-01

    the brainstem structures in novel scans. Thanks to the generative nature of the scheme, the segmentation method is robust to changes in MRI contrast or acquisition hardware. Using cross validation, we show that the algorithm can segment the structures in previously unseen T1 and FLAIR scans with great accuracy...

  15. Congenital segmental dilatation of the colon

    African Journals Online (AJOL)

    Congenital segmental dilatation of the colon is a rare cause of intestinal obstruction in neonates. We report a case of congenital segmental dilatation of the colon and highlight the clinical, radiological, and histopathological features of this entity. Proper surgical treatment was initiated on the basis of preoperative radiological ...

  16. 47 CFR 101.1505 - Segmentation plan.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Segmentation plan. 101.1505 Section 101.1505 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Service and Technical Rules for the 70/80/90 GHz Bands § 101.1505 Segmentation plan. (a) An entity...

  17. Market Segmentation Using Bayesian Model Based Clustering

    NARCIS (Netherlands)

    Van Hattum, P.

    2009-01-01

    This dissertation deals with two basic problems in marketing, that are market segmentation, which is the grouping of persons who share common aspects, and market targeting, which is focusing your marketing efforts on one or more attractive market segments. For the grouping of persons who share

  18. Convolutional Neural Networks for SAR Image Segmentation

    DEFF Research Database (Denmark)

    Malmgren-Hansen, David; Nobel-Jørgensen, Morten

    2015-01-01

    Segmentation of Synthetic Aperture Radar (SAR) images has several uses, but it is a difficult task due to a number of properties related to SAR images. In this article we show how Convolutional Neural Networks (CNNs) can easily be trained for SAR image segmentation with good results. Besides...

  19. Storing tooth segments for optimal esthetics

    NARCIS (Netherlands)

    Tuzuner, T.; Turgut, S.; Özen, B.; Kılınç, H.; Bagis, B.

    2016-01-01

    Objective: A fractured whole crown segment can be reattached to its remnant; crowns from extracted teeth may be used as pontics in splinting techniques. We aimed to evaluate the effect of different storage solutions on tooth segment optical properties after different durations. Study design: Sixty

  20. Benefit segmentation of the fitness market.

    Science.gov (United States)

    Brown, J D

    1992-01-01

    While considerate attention is being paid to the fitness and wellness needs of people by healthcare and related marketing organizations, little research attention has been directed to identifying the market segments for fitness based upon consumers' perceived benefits of fitness. This article describes three distinct segments of fitness consumers comprising an estimated 50 percent of households. Implications for marketing strategies are also presented.

  1. Moving window segmentation framework for point clouds

    NARCIS (Netherlands)

    Sithole, G.; Gorte, B.G.H.

    2012-01-01

    As lidar point clouds become larger streamed processing becomes more attractive. This paper presents a framework for the streamed segmentation of point clouds with the intention of segmenting unstructured point clouds in real-time. The framework is composed of two main components. The first

  2. Current segmented gamma-ray scanner technology

    International Nuclear Information System (INIS)

    Bjork, C.W.

    1987-01-01

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

  3. Creating Web Area Segments with Google Analytics

    Science.gov (United States)

    Segments allow you to quickly access data for a predefined set of Sessions or Users, such as government or education users, or sessions in a particular state. You can then apply this segment to any report within the Google Analytics (GA) interface.

  4. Unsupervised Retinal Vessel Segmentation Using Combined Filters.

    Directory of Open Access Journals (Sweden)

    Wendeson S Oliveira

    Full Text Available Image segmentation of retinal blood vessels is a process that can help to predict and diagnose cardiovascular related diseases, such as hypertension and diabetes, which are known to affect the retinal blood vessels' appearance. This work proposes an unsupervised method for the segmentation of retinal vessels images using a combined matched filter, Frangi's filter and Gabor Wavelet filter to enhance the images. The combination of these three filters in order to improve the segmentation is the main motivation of this work. We investigate two approaches to perform the filter combination: weighted mean and median ranking. Segmentation methods are tested after the vessel enhancement. Enhanced images with median ranking are segmented using a simple threshold criterion. Two segmentation procedures are applied when considering enhanced retinal images using the weighted mean approach. The first method is based on deformable models and the second uses fuzzy C-means for the image segmentation. The procedure is evaluated using two public image databases, Drive and Stare. The experimental results demonstrate that the proposed methods perform well for vessel segmentation in comparison with state-of-the-art methods.

  5. A NEW APPROACH TO SEGMENT HANDWRITTEN DIGITS

    NARCIS (Netherlands)

    Oliveira, L.S.; Lethelier, E.; Bortolozzi, F.; Sabourin, R.

    2004-01-01

    This article presents a new segmentation approach applied to unconstrained handwritten digits. The novelty of the proposed algorithm is based on the combination of two types of structural features in order to provide the best segmentation path between connected entities. In this article, we first

  6. Spinal cord grey matter segmentation challenge.

    Science.gov (United States)

    Prados, Ferran; Ashburner, John; Blaiotta, Claudia; Brosch, Tom; Carballido-Gamio, Julio; Cardoso, Manuel Jorge; Conrad, Benjamin N; Datta, Esha; Dávid, Gergely; Leener, Benjamin De; Dupont, Sara M; Freund, Patrick; Wheeler-Kingshott, Claudia A M Gandini; Grussu, Francesco; Henry, Roland; Landman, Bennett A; Ljungberg, Emil; Lyttle, Bailey; Ourselin, Sebastien; Papinutto, Nico; Saporito, Salvatore; Schlaeger, Regina; Smith, Seth A; Summers, Paul; Tam, Roger; Yiannakas, Marios C; Zhu, Alyssa; Cohen-Adad, Julien

    2017-05-15

    An important image processing step in spinal cord magnetic resonance imaging is the ability to reliably and accurately segment grey and white matter for tissue specific analysis. There are several semi- or fully-automated segmentation methods for cervical cord cross-sectional area measurement with an excellent performance close or equal to the manual segmentation. However, grey matter segmentation is still challenging due to small cross-sectional size and shape, and active research is being conducted by several groups around the world in this field. Therefore a grey matter spinal cord segmentation challenge was organised to test different capabilities of various methods using the same multi-centre and multi-vendor dataset acquired with distinct 3D gradient-echo sequences. This challenge aimed to characterize the state-of-the-art in the field as well as identifying new opportunities for future improvements. Six different spinal cord grey matter segmentation methods developed independently by various research groups across the world and their performance were compared to manual segmentation outcomes, the present gold-standard. All algorithms provided good overall results for detecting the grey matter butterfly, albeit with variable performance in certain quality-of-segmentation metrics. The data have been made publicly available and the challenge web site remains open to new submissions. No modifications were introduced to any of the presented methods as a result of this challenge for the purposes of this publication. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  7. Scale selection for supervised image segmentation

    DEFF Research Database (Denmark)

    Li, Yan; Tax, David M J; Loog, Marco

    2012-01-01

    schemes are usually unsupervised, as they do not take into account the actual segmentation problem at hand. In this paper, we consider the problem of selecting scales, which aims at an optimal discrimination between user-defined classes in the segmentation. We show the deficiency of the classical...

  8. Geophysical investigations over a segment of the Central Indian Ridge, Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    KameshRaju, K.A.; Ramprasad, T.; Subrahmanyam, C.

    Swath bathymetric, gravity, and magnetic studies were carried out over a 55 km long segment of the Central Indian Ridge. The ridge is characterized by 12 to 15 km wide rift valley bounded by steep walls and prominent volcanic constructional ridges...

  9. Creation of voxel-based models for paediatric dosimetry from automatic segmentation methods

    International Nuclear Information System (INIS)

    Acosta, O.; Li, R.; Ourselin, S.; Caon, M.

    2006-01-01

    Full text: The first computational models representing human anatomy were mathematical phantoms, but still far from accurate representations of human body. These models have been used with radiation transport codes (Monte Carlo) to estimate organ doses from radiological procedures. Although new medical imaging techniques have recently allowed the construction of voxel-based models based on the real anatomy, few children models from individual CT or MRI data have been reported [1,3]. For pediatric dosimetry purposes, a large range of voxel models by ages is required since scaling the anatomy from existing models is not sufficiently accurate. The small number of models available arises from the small number of CT or MRI data sets of children available and the long amount of time required to segment the data sets. The existing models have been constructed by manual segmentation slice by slice and using simple thresholding techniques. In medical image segmentation, considerable difficulties appear when applying classical techniques like thresholding or simple edge detection. Until now, any evidence of more accurate or near-automatic methods used in construction of child voxel models exists. We aim to construct a range of pediatric voxel models, integrating automatic or semi-automatic 3D segmentation techniques. In this paper we present the first stage of this work using pediatric CT data.

  10. Constructing Aligned Assessments Using Automated Test Construction

    Science.gov (United States)

    Porter, Andrew; Polikoff, Morgan S.; Barghaus, Katherine M.; Yang, Rui

    2013-01-01

    We describe an innovative automated test construction algorithm for building aligned achievement tests. By incorporating the algorithm into the test construction process, along with other test construction procedures for building reliable and unbiased assessments, the result is much more valid tests than result from current test construction…

  11. Improving image segmentation by learning region affinities

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, Lakshman [Los Alamos National Laboratory; Yang, Xingwei [TEMPLE UNIV.; Latecki, Longin J [TEMPLE UNIV.

    2010-11-03

    We utilize the context information of other regions in hierarchical image segmentation to learn new regions affinities. It is well known that a single choice of quantization of an image space is highly unlikely to be a common optimal quantization level for all categories. Each level of quantization has its own benefits. Therefore, we utilize the hierarchical information among different quantizations as well as spatial proximity of their regions. The proposed affinity learning takes into account higher order relations among image regions, both local and long range relations, making it robust to instabilities and errors of the original, pairwise region affinities. Once the learnt affinities are obtained, we use a standard image segmentation algorithm to get the final segmentation. Moreover, the learnt affinities can be naturally unutilized in interactive segmentation. Experimental results on Berkeley Segmentation Dataset and MSRC Object Recognition Dataset are comparable and in some aspects better than the state-of-art methods.

  12. A Hybrid Technique for Medical Image Segmentation

    Directory of Open Access Journals (Sweden)

    Alamgir Nyma

    2012-01-01

    Full Text Available Medical image segmentation is an essential and challenging aspect in computer-aided diagnosis and also in pattern recognition research. This paper proposes a hybrid method for magnetic resonance (MR image segmentation. We first remove impulsive noise inherent in MR images by utilizing a vector median filter. Subsequently, Otsu thresholding is used as an initial coarse segmentation method that finds the homogeneous regions of the input image. Finally, an enhanced suppressed fuzzy c-means is used to partition brain MR images into multiple segments, which employs an optimal suppression factor for the perfect clustering in the given data set. To evaluate the robustness of the proposed approach in noisy environment, we add different types of noise and different amount of noise to T1-weighted brain MR images. Experimental results show that the proposed algorithm outperforms other FCM based algorithms in terms of segmentation accuracy for both noise-free and noise-inserted MR images.

  13. Monitoring fish distributions along electrofishing segments

    Science.gov (United States)

    Miranda, Leandro E.

    2014-01-01

    Electrofishing is widely used to monitor fish species composition and relative abundance in streams and lakes. According to standard protocols, multiple segments are selected in a body of water to monitor population relative abundance as the ratio of total catch to total sampling effort. The standard protocol provides an assessment of fish distribution at a macrohabitat scale among segments, but not within segments. An ancillary protocol was developed for assessing fish distribution at a finer scale within electrofishing segments. The ancillary protocol was used to estimate spacing, dispersion, and association of two species along shore segments in two local reservoirs. The added information provided by the ancillary protocol may be useful for assessing fish distribution relative to fish of the same species, to fish of different species, and to environmental or habitat characteristics.

  14. Aging and the segmentation of narrative film.

    Science.gov (United States)

    Kurby, Christopher A; Asiala, Lillian K E; Mills, Steven R

    2014-01-01

    The perception of event structure in continuous activity is important for everyday comprehension. Although the segmentation of experience into events is a normal concomitant of perceptual processing, previous research has shown age differences in the ability to perceive structure in naturalistic activity, such as a movie of someone washing a car. However, past research has also shown that older adults have a preserved ability to comprehend events in narrative text, which suggests that narrative may improve the event processing of older adults. This study tested whether there are age differences in event segmentation at the intersection of continuous activity and narrative: narrative film. Younger and older adults watched and segmented a narrative film, The Red Balloon, into coarse and fine events. Changes in situational features, such as changes in characters, goals, and objects predicted segmentation. Analyses revealed little age-difference in segmentation behavior. This suggests the possibility that narrative structure supports event understanding for older adults.

  15. Cavity contour segmentation in chest radiographs using supervised learning and dynamic programming

    Energy Technology Data Exchange (ETDEWEB)

    Maduskar, Pragnya, E-mail: pragnya.maduskar@radboudumc.nl; Hogeweg, Laurens; Sánchez, Clara I.; Ginneken, Bram van [Diagnostic Image Analysis Group, Radboud University Medical Center, Nijmegen, 6525 GA (Netherlands); Jong, Pim A. de [Department of Radiology, University Medical Center Utrecht, 3584 CX (Netherlands); Peters-Bax, Liesbeth [Department of Radiology, Radboud University Medical Center, Nijmegen, 6525 GA (Netherlands); Dawson, Rodney [University of Cape Town Lung Institute, Cape Town 7700 (South Africa); Ayles, Helen [Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London WC1E 7HT (United Kingdom)

    2014-07-15

    Purpose: Efficacy of tuberculosis (TB) treatment is often monitored using chest radiography. Monitoring size of cavities in pulmonary tuberculosis is important as the size predicts severity of the disease and its persistence under therapy predicts relapse. The authors present a method for automatic cavity segmentation in chest radiographs. Methods: A two stage method is proposed to segment the cavity borders, given a user defined seed point close to the center of the cavity. First, a supervised learning approach is employed to train a pixel classifier using texture and radial features to identify the border pixels of the cavity. A likelihood value of belonging to the cavity border is assigned to each pixel by the classifier. The authors experimented with four different classifiers:k-nearest neighbor (kNN), linear discriminant analysis (LDA), GentleBoost (GB), and random forest (RF). Next, the constructed likelihood map was used as an input cost image in the polar transformed image space for dynamic programming to trace the optimal maximum cost path. This constructed path corresponds to the segmented cavity contour in image space. Results: The method was evaluated on 100 chest radiographs (CXRs) containing 126 cavities. The reference segmentation was manually delineated by an experienced chest radiologist. An independent observer (a chest radiologist) also delineated all cavities to estimate interobserver variability. Jaccard overlap measure Ω was computed between the reference segmentation and the automatic segmentation; and between the reference segmentation and the independent observer's segmentation for all cavities. A median overlap Ω of 0.81 (0.76 ± 0.16), and 0.85 (0.82 ± 0.11) was achieved between the reference segmentation and the automatic segmentation, and between the segmentations by the two radiologists, respectively. The best reported mean contour distance and Hausdorff distance between the reference and the automatic segmentation were

  16. Cavity contour segmentation in chest radiographs using supervised learning and dynamic programming

    International Nuclear Information System (INIS)

    Maduskar, Pragnya; Hogeweg, Laurens; Sánchez, Clara I.; Ginneken, Bram van; Jong, Pim A. de; Peters-Bax, Liesbeth; Dawson, Rodney; Ayles, Helen

    2014-01-01

    Purpose: Efficacy of tuberculosis (TB) treatment is often monitored using chest radiography. Monitoring size of cavities in pulmonary tuberculosis is important as the size predicts severity of the disease and its persistence under therapy predicts relapse. The authors present a method for automatic cavity segmentation in chest radiographs. Methods: A two stage method is proposed to segment the cavity borders, given a user defined seed point close to the center of the cavity. First, a supervised learning approach is employed to train a pixel classifier using texture and radial features to identify the border pixels of the cavity. A likelihood value of belonging to the cavity border is assigned to each pixel by the classifier. The authors experimented with four different classifiers:k-nearest neighbor (kNN), linear discriminant analysis (LDA), GentleBoost (GB), and random forest (RF). Next, the constructed likelihood map was used as an input cost image in the polar transformed image space for dynamic programming to trace the optimal maximum cost path. This constructed path corresponds to the segmented cavity contour in image space. Results: The method was evaluated on 100 chest radiographs (CXRs) containing 126 cavities. The reference segmentation was manually delineated by an experienced chest radiologist. An independent observer (a chest radiologist) also delineated all cavities to estimate interobserver variability. Jaccard overlap measure Ω was computed between the reference segmentation and the automatic segmentation; and between the reference segmentation and the independent observer's segmentation for all cavities. A median overlap Ω of 0.81 (0.76 ± 0.16), and 0.85 (0.82 ± 0.11) was achieved between the reference segmentation and the automatic segmentation, and between the segmentations by the two radiologists, respectively. The best reported mean contour distance and Hausdorff distance between the reference and the automatic segmentation were

  17. Colour application on mammography image segmentation

    Science.gov (United States)

    Embong, R.; Aziz, N. M. Nik Ab.; Karim, A. H. Abd; Ibrahim, M. R.

    2017-09-01

    The segmentation process is one of the most important steps in image processing and computer vision since it is vital in the initial stage of image analysis. Segmentation of medical images involves complex structures and it requires precise segmentation result which is necessary for clinical diagnosis such as the detection of tumour, oedema, and necrotic tissues. Since mammography images are grayscale, researchers are looking at the effect of colour in the segmentation process of medical images. Colour is known to play a significant role in the perception of object boundaries in non-medical colour images. Processing colour images require handling more data, hence providing a richer description of objects in the scene. Colour images contain ten percent (10%) additional edge information as compared to their grayscale counterparts. Nevertheless, edge detection in colour image is more challenging than grayscale image as colour space is considered as a vector space. In this study, we implemented red, green, yellow, and blue colour maps to grayscale mammography images with the purpose of testing the effect of colours on the segmentation of abnormality regions in the mammography images. We applied the segmentation process using the Fuzzy C-means algorithm and evaluated the percentage of average relative error of area for each colour type. The results showed that all segmentation with the colour map can be done successfully even for blurred and noisy images. Also the size of the area of the abnormality region is reduced when compare to the segmentation area without the colour map. The green colour map segmentation produced the smallest percentage of average relative error (10.009%) while yellow colour map segmentation gave the largest percentage of relative error (11.367%).

  18. SEGMENTATION OF SME PORTFOLIO IN BANKING SYSTEM

    Directory of Open Access Journals (Sweden)

    Namolosu Simona Mihaela

    2013-07-01

    Full Text Available The Small and Medium Enterprises (SMEs represent an important target market for commercial Banks. In this respect, finding the best methods for designing and implementing the optimal marketing strategies (for this target are a continuous concern for the marketing specialists and researchers from the banking system; the purpose is to find the most suitable service model for these companies. SME portfolio of a bank is not homogeneous, different characteristics and behaviours being identified. The current paper reveals empirical evidence about SME portfolio characteristics and segmentation methods used in banking system. Its purpose is to identify if segmentation has an impact in finding the optimal marketing strategies and service model and if this hypothesis might be applicable for any commercial bank, irrespective of country/ region. Some banks are segmenting the SME portfolio by a single criterion: the annual company (official turnover; others are considering also profitability and other financial indicators of the company. In some cases, even the banking behaviour becomes a criterion. For all cases, creating scenarios with different thresholds and estimating the impact in profitability and volumes are two mandatory steps in establishing the final segmentation (criteria matrix. Details about each of these segmentation methods may be found in the paper. Testing the final matrix of criteria is also detailed, with the purpose of making realistic estimations. Example for lending products is provided; the product offer is presented as responding to needs of targeted sub segment and therefore being correlated with the sub segment characteristics. Identifying key issues and trends leads to further action plan proposal. Depending on overall strategy and commercial target of the bank, the focus may shift, one or more sub segments becoming high priority (for acquisition/ activation/ retention/ cross sell/ up sell/ increase profitability etc., while

  19. Perspectives of construction robots

    Science.gov (United States)

    Stepanov, M. A.; Gridchin, A. M.

    2018-03-01

    This article is an overview of construction robots features, based on formulating the list of requirements for different types of construction robots in relation to different types of construction works.. It describes a variety of construction works and ways to construct new or to adapt existing robot designs for a construction process. Also, it shows the prospects of AI-controlled machines, implementation of automated control systems and networks on construction sites. In the end, different ways to develop and improve, including ecological aspect, the construction process through the wide robotization, creating of data communication networks and, in perspective, establishing of fully AI-controlled construction complex are formulated.

  20. Construction completion report

    International Nuclear Information System (INIS)

    1990-01-01

    This Construction Completion Report documents the major construction projects at the Waste Isolation Pilot Plant (WIPP) site and related information on contracts, schedules, and other areas which affected construction. This report is not intended to be an exhaustive detailed analysis of construction, but is a general overview and summary of the WIPP construction. 10 refs., 29 figs

  1. Whole vertebral bone segmentation method with a statistical intensity-shape model based approach

    Science.gov (United States)

    Hanaoka, Shouhei; Fritscher, Karl; Schuler, Benedikt; Masutani, Yoshitaka; Hayashi, Naoto; Ohtomo, Kuni; Schubert, Rainer

    2011-03-01

    An automatic segmentation algorithm for the vertebrae in human body CT images is presented. Especially we focused on constructing and utilizing 4 different statistical intensity-shape combined models for the cervical, upper / lower thoracic and lumbar vertebrae, respectively. For this purpose, two previously reported methods were combined: a deformable model-based initial segmentation method and a statistical shape-intensity model-based precise segmentation method. The former is used as a pre-processing to detect the position and orientation of each vertebra, which determines the initial condition for the latter precise segmentation method. The precise segmentation method needs prior knowledge on both the intensities and the shapes of the objects. After PCA analysis of such shape-intensity expressions obtained from training image sets, vertebrae were parametrically modeled as a linear combination of the principal component vectors. The segmentation of each target vertebra was performed as fitting of this parametric model to the target image by maximum a posteriori estimation, combined with the geodesic active contour method. In the experimental result by using 10 cases, the initial segmentation was successful in 6 cases and only partially failed in 4 cases (2 in the cervical area and 2 in the lumbo-sacral). In the precise segmentation, the mean error distances were 2.078, 1.416, 0.777, 0.939 mm for cervical, upper and lower thoracic, lumbar spines, respectively. In conclusion, our automatic segmentation algorithm for the vertebrae in human body CT images showed a fair performance for cervical, thoracic and lumbar vertebrae.

  2. Method of manufacturing a large-area segmented photovoltaic module

    Science.gov (United States)

    Lenox, Carl

    2013-11-05

    One embodiment of the invention relates to a segmented photovoltaic (PV) module which is manufactured from laminate segments. The segmented PV module includes rectangular-shaped laminate segments formed from rectangular-shaped PV laminates and further includes non-rectangular-shaped laminate segments formed from rectangular-shaped and approximately-triangular-shaped PV laminates. The laminate segments are mechanically joined and electrically interconnected to form the segmented module. Another embodiment relates to a method of manufacturing a large-area segmented photovoltaic module from laminate segments of various shapes. Other embodiments relate to processes for providing a photovoltaic array for installation at a site. Other embodiments and features are also disclosed.

  3. Study of the morphology exhibited by linear segmented polyurethanes

    International Nuclear Information System (INIS)

    Pereira, I.M.; Orefice, R.L.

    2009-01-01

    Five series of segmented polyurethanes with different hard segment content were prepared by the prepolymer mixing method. The nano-morphology of the obtained polyurethanes and their microphase separation were investigated by infrared spectroscopy, modulated differential scanning calorimetry and small-angle X-ray scattering. Although highly hydrogen bonded hard segments were formed, high hard segment contents promoted phase mixture and decreased the chain mobility, decreasing the hard segment domain precipitation and the soft segments crystallization. The applied techniques were able to show that the hard-segment content and the hard-segment interactions were the two controlling factors for determining the structure of segmented polyurethanes. (author)

  4. Performance Analysis of Segmentation of Hyperspectral Images Based on Color Image Segmentation

    Directory of Open Access Journals (Sweden)

    Praveen Agarwal

    2017-06-01

    Full Text Available Image segmentation is a fundamental approach in the field of image processing and based on user’s application .This paper propose an original and simple segmentation strategy based on the EM approach that resolves many informatics problems about hyperspectral images which are observed by airborne sensors. In a first step, to simplify the input color textured image into a color image without texture. The final segmentation is simply achieved by a spatially color segmentation using feature vector with the set of color values contained around the pixel to be classified with some mathematical equations. The spatial constraint allows taking into account the inherent spatial relationships of any image and its color. This approach provides effective PSNR for the segmented image. These results have the better performance as the segmented images are compared with Watershed & Region Growing Algorithm and provide effective segmentation for the Spectral Images & Medical Images.

  5. Polyether based segmented copolymers with uniform aramid units

    NARCIS (Netherlands)

    Niesten, M.C.E.J.

    2000-01-01

    Segmented copolymers with short, glassy or crystalline hard segments and long, amorphous soft segments (multi-block copolymers) are thermoplastic elastomers (TPE’s). The hard segments form physical crosslinks for the amorphous (rubbery) soft segments. As a result, this type of materials combines

  6. Concrete construction engineering handbook

    CERN Document Server

    Nawy, Edward G

    2008-01-01

    Provides coverage of concrete construction engineering and technology. This work features discussions focusing on: the advances in engineered concrete materials; reinforced concrete construction; specialized construction techniques; and, design recommendations for high performance.

  7. Cluster Ensemble-Based Image Segmentation

    Directory of Open Access Journals (Sweden)

    Xiaoru Wang

    2013-07-01

    Full Text Available Image segmentation is the foundation of computer vision applications. In this paper, we propose a new cluster ensemble-based image segmentation algorithm, which overcomes several problems of traditional methods. We make two main contributions in this paper. First, we introduce the cluster ensemble concept to fuse the segmentation results from different types of visual features effectively, which can deliver a better final result and achieve a much more stable performance for broad categories of images. Second, we exploit the PageRank idea from Internet applications and apply it to the image segmentation task. This can improve the final segmentation results by combining the spatial information of the image and the semantic similarity of regions. Our experiments on four public image databases validate the superiority of our algorithm over conventional single type of feature or multiple types of features-based algorithms, since our algorithm can fuse multiple types of features effectively for better segmentation results. Moreover, our method is also proved to be very competitive in comparison with other state-of-the-art segmentation algorithms.

  8. An unsupervised strategy for biomedical image segmentation

    Directory of Open Access Journals (Sweden)

    Roberto Rodríguez

    2010-09-01

    Full Text Available Roberto Rodríguez1, Rubén Hernández21Digital Signal Processing Group, Institute of Cybernetics, Mathematics, and Physics, Havana, Cuba; 2Interdisciplinary Professional Unit of Engineering and Advanced Technology, IPN, MexicoAbstract: Many segmentation techniques have been published, and some of them have been widely used in different application problems. Most of these segmentation techniques have been motivated by specific application purposes. Unsupervised methods, which do not assume any prior scene knowledge can be learned to help the segmentation process, and are obviously more challenging than the supervised ones. In this paper, we present an unsupervised strategy for biomedical image segmentation using an algorithm based on recursively applying mean shift filtering, where entropy is used as a stopping criterion. This strategy is proven with many real images, and a comparison is carried out with manual segmentation. With the proposed strategy, errors less than 20% for false positives and 0% for false negatives are obtained.Keywords: segmentation, mean shift, unsupervised segmentation, entropy

  9. Segmentation precedes face categorization under suboptimal conditions

    Directory of Open Access Journals (Sweden)

    Carlijn eVan Den Boomen

    2015-05-01

    Full Text Available Both categorization and segmentation processes play a crucial role in face perception. However, the functional relation between these subprocesses is currently unclear. The present study investigates the temporal relation between segmentation-related and category-selective responses in the brain, using electroencephalography (EEG. Surface segmentation and category content were both manipulated using texture-defined objects, including faces. This allowed us to study brain activity related to segmentation and to categorization. In the main experiment, participants viewed texture-defined objects for a duration of 800 ms. EEG results revealed that segmentation-related responses precede category-selective responses. Three additional experiments revealed that the presence and timing of categorization depends on stimulus properties and presentation duration. Photographic objects were presented for a long and short (92 ms duration and evoked fast category-selective responses in both cases. On the other hand, presentation of texture-defined objects for a short duration only evoked segmentation-related but no category-selective responses. Category-selective responses were much slower when evoked by texture-defined than by photographic objects. We suggest that in case of categorization of objects under suboptimal conditions, such as when low-level stimulus properties are not sufficient for fast object categorization, segmentation facilitates the slower categorization process.

  10. Incorporation of squalene into rod outer segments

    International Nuclear Information System (INIS)

    Keller, R.K.; Fliesler, S.J.

    1990-01-01

    We have reported previously that squalene is the major radiolabeled nonsaponifiable lipid product derived from [ 3 H]acetate in short term incubations of frog retinas. In the present study, we demonstrate that newly synthesized squalene is incorporated into rod outer segments under similar in vitro conditions. We show further that squalene is an endogenous constituent of frog rod outer segment membranes; its concentration is approximately 9.5 nmol/mumol of phospholipid or about 9% of the level of cholesterol. Pulse-chase experiments with radiolabeled precursors revealed no metabolism of outer segment squalene to sterols in up to 20 h of chase. Taken together with our previous absolute rate studies, these results suggest that most, if not all, of the squalene synthesized by the frog retina is transported to rod outer segments. Synthesis of protein is not required for squalene transport since puromycin had no effect on squalene incorporation into outer segments. Conversely, inhibition of isoprenoid synthesis with mevinolin had no effect on the incorporation of opsin into the outer segment. These latter results support the conclusion that the de novo synthesis and subsequent intracellular trafficking of opsin and isoprenoid lipids destined for the outer segment occur via independent mechanisms

  11. A Kalman Filtering Perspective for Multiatlas Segmentation*

    Science.gov (United States)

    Gao, Yi; Zhu, Liangjia; Cates, Joshua; MacLeod, Rob S.; Bouix, Sylvain; Tannenbaum, Allen

    2016-01-01

    In multiatlas segmentation, one typically registers several atlases to the novel image, and their respective segmented label images are transformed and fused to form the final segmentation. In this work, we provide a new dynamical system perspective for multiatlas segmentation, inspired by the following fact: The transformation that aligns the current atlas to the novel image can be not only computed by direct registration but also inferred from the transformation that aligns the previous atlas to the image together with the transformation between the two atlases. This process is similar to the global positioning system on a vehicle, which gets position by inquiring from the satellite and by employing the previous location and velocity—neither answer in isolation being perfect. To solve this problem, a dynamical system scheme is crucial to combine the two pieces of information; for example, a Kalman filtering scheme is used. Accordingly, in this work, a Kalman multiatlas segmentation is proposed to stabilize the global/affine registration step. The contributions of this work are twofold. First, it provides a new dynamical systematic perspective for standard independent multiatlas registrations, and it is solved by Kalman filtering. Second, with very little extra computation, it can be combined with most existing multiatlas segmentation schemes for better registration/segmentation accuracy. PMID:26807162

  12. Segmentation-less Digital Rock Physics

    Science.gov (United States)

    Tisato, N.; Ikeda, K.; Goldfarb, E. J.; Spikes, K. T.

    2017-12-01

    In the last decade, Digital Rock Physics (DRP) has become an avenue to investigate physical and mechanical properties of geomaterials. DRP offers the advantage of simulating laboratory experiments on numerical samples that are obtained from analytical methods. Potentially, DRP could allow sparing part of the time and resources that are allocated to perform complicated laboratory tests. Like classic laboratory tests, the goal of DRP is to estimate accurately physical properties of rocks like hydraulic permeability or elastic moduli. Nevertheless, the physical properties of samples imaged using micro-computed tomography (μCT) are estimated through segmentation of the μCT dataset. Segmentation proves to be a challenging and arbitrary procedure that typically leads to inaccurate estimates of physical properties. Here we present a novel technique to extract physical properties from a μCT dataset without the use of segmentation. We show examples in which we use segmentation-less method to simulate elastic wave propagation and pressure wave diffusion to estimate elastic properties and permeability, respectively. The proposed method takes advantage of effective medium theories and uses the density and the porosity that are measured in the laboratory to constrain the results. We discuss the results and highlight that segmentation-less DRP is more accurate than segmentation based DRP approaches and theoretical modeling for the studied rock. In conclusion, the segmentation-less approach here presented seems to be a promising method to improve accuracy and to ease the overall workflow of DRP.

  13. Segmentation precedes face categorization under suboptimal conditions.

    Science.gov (United States)

    Van Den Boomen, Carlijn; Fahrenfort, Johannes J; Snijders, Tineke M; Kemner, Chantal

    2015-01-01

    Both categorization and segmentation processes play a crucial role in face perception. However, the functional relation between these subprocesses is currently unclear. The present study investigates the temporal relation between segmentation-related and category-selective responses in the brain, using electroencephalography (EEG). Surface segmentation and category content were both manipulated using texture-defined objects, including faces. This allowed us to study brain activity related to segmentation and to categorization. In the main experiment, participants viewed texture-defined objects for a duration of 800 ms. EEG results revealed that segmentation-related responses precede category-selective responses. Three additional experiments revealed that the presence and timing of categorization depends on stimulus properties and presentation duration. Photographic objects were presented for a long and short (92 ms) duration and evoked fast category-selective responses in both cases. On the other hand, presentation of texture-defined objects for a short duration only evoked segmentation-related but no category-selective responses. Category-selective responses were much slower when evoked by texture-defined than by photographic objects. We suggest that in case of categorization of objects under suboptimal conditions, such as when low-level stimulus properties are not sufficient for fast object categorization, segmentation facilitates the slower categorization process.

  14. Bayesian automated cortical segmentation for neonatal MRI

    Science.gov (United States)

    Chou, Zane; Paquette, Natacha; Ganesh, Bhavana; Wang, Yalin; Ceschin, Rafael; Nelson, Marvin D.; Macyszyn, Luke; Gaonkar, Bilwaj; Panigrahy, Ashok; Lepore, Natasha

    2017-11-01

    Several attempts have been made in the past few years to develop and implement an automated segmentation of neonatal brain structural MRI. However, accurate automated MRI segmentation remains challenging in this population because of the low signal-to-noise ratio, large partial volume effects and inter-individual anatomical variability of the neonatal brain. In this paper, we propose a learning method for segmenting the whole brain cortical grey matter on neonatal T2-weighted images. We trained our algorithm using a neonatal dataset composed of 3 fullterm and 4 preterm infants scanned at term equivalent age. Our segmentation pipeline combines the FAST algorithm from the FSL library software and a Bayesian segmentation approach to create a threshold matrix that minimizes the error of mislabeling brain tissue types. Our method shows promising results with our pilot training set. In both preterm and full-term neonates, automated Bayesian segmentation generates a smoother and more consistent parcellation compared to FAST, while successfully removing the subcortical structure and cleaning the edges of the cortical grey matter. This method show promising refinement of the FAST segmentation by considerably reducing manual input and editing required from the user, and further improving reliability and processing time of neonatal MR images. Further improvement will include a larger dataset of training images acquired from different manufacturers.

  15. Deformable segmentation via sparse shape representation.

    Science.gov (United States)

    Zhang, Shaoting; Zhan, Yiqiang; Dewan, Maneesh; Huang, Junzhou; Metaxas, Dimitris N; Zhou, Xiang Sean

    2011-01-01

    Appearance and shape are two key elements exploited in medical image segmentation. However, in some medical image analysis tasks, appearance cues are weak/misleading due to disease/artifacts and often lead to erroneous segmentation. In this paper, a novel deformable model is proposed for robust segmentation in the presence of weak/misleading appearance cues. Owing to the less trustable appearance information, this method focuses on the effective shape modeling with two contributions. First, a shape composition method is designed to incorporate shape prior on-the-fly. Based on two sparsity observations, this method is robust to false appearance information and adaptive to statistically insignificant shape modes. Second, shape priors are modeled and used in a hierarchical fashion. More specifically, by using affinity propagation method, our deformable surface is divided into multiple partitions, on which local shape models are built independently. This scheme facilitates a more compact shape prior modeling and hence a more robust and efficient segmentation. Our deformable model is applied on two very diverse segmentation problems, liver segmentation in PET-CT images and rodent brain segmentation in MR images. Compared to state-of-art methods, our method achieves better performance in both studies.

  16. Unsupervised Segmentation Methods of TV Contents

    Directory of Open Access Journals (Sweden)

    Elie El-Khoury

    2010-01-01

    Full Text Available We present a generic algorithm to address various temporal segmentation topics of audiovisual contents such as speaker diarization, shot, or program segmentation. Based on a GLR approach, involving the ΔBIC criterion, this algorithm requires the value of only a few parameters to produce segmentation results at a desired scale and on most typical low-level features used in the field of content-based indexing. Results obtained on various corpora are of the same quality level than the ones obtained by other dedicated and state-of-the-art methods.

  17. Contractual Incompleteness, Unemployment, and Labour Market Segmentation

    DEFF Research Database (Denmark)

    Altmann, Steffen; Falk, Armin; Grunewald, Andreas

    2014-01-01

    This article provides evidence that involuntary unemployment, and the segmentation of labour markets into firms offering "good" and "bad" jobs, may both arise as a consequence of contractual incompleteness.We provide a simple model that illustrates how unemployment and market segmentation may...... jointly emerge as part of a market equilibrium in environments where work effort is not third-party verifiable. Using experimental labour markets that differ only in the verifiability of effort, we demonstrate empirically that contractual incompleteness can cause unemployment and segmentation. Our data...

  18. Multi-scale Modelling of Segmentation

    DEFF Research Database (Denmark)

    Hartmann, Martin; Lartillot, Olivier; Toiviainen, Petri

    2016-01-01

    pieces. In a second experiment on non-real-time segmentation, musicians indicated boundaries and their strength for six examples. Kernel density estimation was used to develop multi-scale segmentation models. Contrary to previous research, no relationship was found between boundary strength and boundary......While listening to music, people often unwittingly break down musical pieces into constituent chunks such as verses and choruses. Music segmentation studies have suggested that some consensus regarding boundary perception exists, despite individual differences. However, neither the effects...

  19. Polarimetric Segmentation Using Wishart Test Statistic

    DEFF Research Database (Denmark)

    Skriver, Henning; Schou, Jesper; Nielsen, Allan Aasbjerg

    2002-01-01

    A newly developed test statistic for equality of two complex covariance matrices following the complex Wishart distribution and an associated asymptotic probability for the test statistic has been used in a segmentation algorithm. The segmentation algorithm is based on the MUM (merge using moments......) approach, which is a merging algorithm for single channel SAR images. The polarimetric version described in this paper uses the above-mentioned test statistic for merging. The segmentation algorithm has been applied to polarimetric SAR data from the Danish dual-frequency, airborne polarimetric SAR, EMISAR...

  20. Attributed relational graphs for cell nucleus segmentation in fluorescence microscopy images.

    Science.gov (United States)

    Arslan, Salim; Ersahin, Tulin; Cetin-Atalay, Rengul; Gunduz-Demir, Cigdem

    2013-06-01

    More rapid and accurate high-throughput screening in molecular cellular biology research has become possible with the development of automated microscopy imaging, for which cell nucleus segmentation commonly constitutes the core step. Although several promising methods exist for segmenting the nuclei of monolayer isolated and less-confluent cells, it still remains an open problem to segment the nuclei of more-confluent cells, which tend to grow in overlayers. To address this problem, we propose a new model-based nucleus segmentation algorithm. This algorithm models how a human locates a nucleus by identifying the nucleus boundaries and piecing them together. In this algorithm, we define four types of primitives to represent nucleus boundaries at different orientations and construct an attributed relational graph on the primitives to represent their spatial relations. Then, we reduce the nucleus identification problem to finding predefined structural patterns in the constructed graph and also use the primitives in region growing to delineate the nucleus borders. Working with fluorescence microscopy images, our experiments demonstrate that the proposed algorithm identifies nuclei better than previous nucleus segmentation algorithms.

  1. Fabrication of a segmented composite stainless steel-alumina discharge tube for a theta-pinch coil

    International Nuclear Information System (INIS)

    Dickinson, J.M.; Stoddard, S.D.; Muller, J.F.

    1975-11-01

    An 80-mm-diam segmented discharge tube that simulated in a simplified way the blanket and first wall of the Reference Theta-Pinch Reactor (RTPR) has been constructed. The segments were fabricated by plasma-arc spraying an alumina coating on tubular stainless steel trapezoids. These were laid up to form a cylinder that was contained in a fully dense alumina vacuum tube. The fabrication processes are discussed in detail

  2. A proposed framework for consensus-based lung tumour volume auto-segmentation in 4D computed tomography imaging

    Science.gov (United States)

    Martin, Spencer; Brophy, Mark; Palma, David; Louie, Alexander V.; Yu, Edward; Yaremko, Brian; Ahmad, Belal; Barron, John L.; Beauchemin, Steven S.; Rodrigues, George; Gaede, Stewart

    2015-02-01

    This work aims to propose and validate a framework for tumour volume auto-segmentation based on ground-truth estimates derived from multi-physician input contours to expedite 4D-CT based lung tumour volume delineation. 4D-CT datasets of ten non-small cell lung cancer (NSCLC) patients were manually segmented by 6 physicians. Multi-expert ground truth (GT) estimates were constructed using the STAPLE algorithm for the gross tumour volume (GTV) on all respiratory phases. Next, using a deformable model-based method, multi-expert GT on each individual phase of the 4D-CT dataset was propagated to all other phases providing auto-segmented GTVs and motion encompassing internal gross target volumes (IGTVs) based on GT estimates (STAPLE) from each respiratory phase of the 4D-CT dataset. Accuracy assessment of auto-segmentation employed graph cuts for 3D-shape reconstruction and point-set registration-based analysis yielding volumetric and distance-based measures. STAPLE-based auto-segmented GTV accuracy ranged from (81.51  ±  1.92) to (97.27  ±  0.28)% volumetric overlap of the estimated ground truth. IGTV auto-segmentation showed significantly improved accuracies with reduced variance for all patients ranging from 90.87 to 98.57% volumetric overlap of the ground truth volume. Additional metrics supported these observations with statistical significance. Accuracy of auto-segmentation was shown to be largely independent of selection of the initial propagation phase. IGTV construction based on auto-segmented GTVs within the 4D-CT dataset provided accurate and reliable target volumes compared to manual segmentation-based GT estimates. While inter-/intra-observer effects were largely mitigated, the proposed segmentation workflow is more complex than that of current clinical practice and requires further development.

  3. A proposed framework for consensus-based lung tumour volume auto-segmentation in 4D computed tomography imaging

    International Nuclear Information System (INIS)

    Martin, Spencer; Rodrigues, George; Gaede, Stewart; Brophy, Mark; Barron, John L; Beauchemin, Steven S; Palma, David; Louie, Alexander V; Yu, Edward; Yaremko, Brian; Ahmad, Belal

    2015-01-01

    This work aims to propose and validate a framework for tumour volume auto-segmentation based on ground-truth estimates derived from multi-physician input contours to expedite 4D-CT based lung tumour volume delineation. 4D-CT datasets of ten non-small cell lung cancer (NSCLC) patients were manually segmented by 6 physicians. Multi-expert ground truth (GT) estimates were constructed using the STAPLE algorithm for the gross tumour volume (GTV) on all respiratory phases. Next, using a deformable model-based method, multi-expert GT on each individual phase of the 4D-CT dataset was propagated to all other phases providing auto-segmented GTVs and motion encompassing internal gross target volumes (IGTVs) based on GT estimates (STAPLE) from each respiratory phase of the 4D-CT dataset. Accuracy assessment of auto-segmentation employed graph cuts for 3D-shape reconstruction and point-set registration-based analysis yielding volumetric and distance-based measures. STAPLE-based auto-segmented GTV accuracy ranged from (81.51  ±  1.92) to (97.27  ±  0.28)% volumetric overlap of the estimated ground truth. IGTV auto-segmentation showed significantly improved accuracies with reduced variance for all patients ranging from 90.87 to 98.57% volumetric overlap of the ground truth volume. Additional metrics supported these observations with statistical significance. Accuracy of auto-segmentation was shown to be largely independent of selection of the initial propagation phase. IGTV construction based on auto-segmented GTVs within the 4D-CT dataset provided accurate and reliable target volumes compared to manual segmentation-based GT estimates. While inter-/intra-observer effects were largely mitigated, the proposed segmentation workflow is more complex than that of current clinical practice and requires further development. (paper)

  4. Leisure market segmentation : an integrated preferences/constraints-based approach

    NARCIS (Netherlands)

    Stemerding, M.P.; Oppewal, H.; Beckers, T.A.M.; Timmermans, H.J.P.

    1996-01-01

    Traditional segmentation schemes are often based on a grouping of consumers with similar preference functions. The research steps, ultimately leading to such segmentation schemes, are typically independent. In the present article, a new integrated approach to segmentation is introduced, which

  5. An Overview of Techniques for Cardiac Left Ventricle Segmentation on Short-Axis MRI

    Directory of Open Access Journals (Sweden)

    Krasnobaev Arseny

    2016-01-01

    Full Text Available Nowadays, heart diseases are the leading cause of death. Left ventricle segmentation of a human heart in magnetic resonance images (MRI is a crucial step in both cardiac diseases diagnostics and heart internal structure reconstruction. It allows estimating such important parameters as ejection faction, left ventricle myocardium mass, stroke volume, etc. In addition, left ventricle segmentation helps to construct the personalized heart computational models in order to conduct the numerical simulations. At present, the fully automated cardiac segmentation methods still do not meet the accuracy requirements. We present an overview of left ventricle segmentation algorithms on short-axis MRI. A wide variety of completely different approaches are used for cardiac segmentation, including machine learning, graph-based methods, deformable models, and low-level heuristics. The current state-of-the-art technique is a combination of deformable models with advanced machine learning methods, such as deep learning or Markov random fields. We expect that approaches based on deep belief networks are the most promising ones because the main training process of networks with this architecture can be performed on the unlabelled data. In order to improve the quality of left ventricle segmentation algorithms, we need more datasets with labelled cardiac MRI data in open access.

  6. Segmentation of clustered cells in negative phase contrast images with integrated light intensity and cell shape information.

    Science.gov (United States)

    Wang, Y; Wang, C; Zhang, Z

    2018-05-01

    Automated cell segmentation plays a key role in characterisations of cell behaviours for both biology research and clinical practices. Currently, the segmentation of clustered cells still remains as a challenge and is the main reason for false segmentation. In this study, the emphasis was put on the segmentation of clustered cells in negative phase contrast images. A new method was proposed to combine both light intensity and cell shape information through the construction of grey-weighted distance transform (GWDT) within preliminarily segmented areas. With the constructed GWDT, the clustered cells can be detected and then separated with a modified region skeleton-based method. Moreover, a contour expansion operation was applied to get optimised detection of cell boundaries. In this paper, the working principle and detailed procedure of the proposed method are described, followed by the evaluation of the method on clustered cell segmentation. Results show that the proposed method achieves an improved performance in clustered cell segmentation compared with other methods, with 85.8% and 97.16% accuracy rate for clustered cells and all cells, respectively. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  7. Multi-phase simultaneous segmentation of tumor in lung 4D-CT data with context information.

    Directory of Open Access Journals (Sweden)

    Zhengwen Shen

    Full Text Available Lung 4D computed tomography (4D-CT plays an important role in high-precision radiotherapy because it characterizes respiratory motion, which is crucial for accurate target definition. However, the manual segmentation of a lung tumor is a heavy workload for doctors because of the large number of lung 4D-CT data slices. Meanwhile, tumor segmentation is still a notoriously challenging problem in computer-aided diagnosis. In this paper, we propose a new method based on an improved graph cut algorithm with context information constraint to find a convenient and robust approach of lung 4D-CT tumor segmentation. We combine all phases of the lung 4D-CT into a global graph, and construct a global energy function accordingly. The sub-graph is first constructed for each phase. A context cost term is enforced to achieve segmentation results in every phase by adding a context constraint between neighboring phases. A global energy function is finally constructed by combining all cost terms. The optimization is achieved by solving a max-flow/min-cut problem, which leads to simultaneous and robust segmentation of the tumor in all the lung 4D-CT phases. The effectiveness of our approach is validated through experiments on 10 different lung 4D-CT cases. The comparison with the graph cut without context constraint, the level set method and the graph cut with star shape prior demonstrates that the proposed method obtains more accurate and robust segmentation results.

  8. Segmentation of human skull in MRI using statistical shape information from CT data.

    Science.gov (United States)

    Wang, Defeng; Shi, Lin; Chu, Winnie C W; Cheng, Jack C Y; Heng, Pheng Ann

    2009-09-01

    To automatically segment the skull from the MRI data using a model-based three-dimensional segmentation scheme. This study exploited the statistical anatomy extracted from the CT data of a group of subjects by means of constructing an active shape model of the skull surfaces. To construct a reliable shape model, a novel approach was proposed to optimize the automatic landmarking on the coupled surfaces (i.e., the skull vault) by minimizing the description length that incorporated local thickness information. This model was then used to locate the skull shape in MRI of a different group of patients. Compared with performing landmarking separately on the coupled surfaces, the proposed landmarking method constructed models that had better generalization ability and specificity. The segmentation accuracies were measured by the Dice coefficient and the set difference, and compared with the method based on mathematical morphology operations. The proposed approach using the active shape model based on the statistical skull anatomy presented in the head CT data contributes to more reliable segmentation of the skull from MRI data.

  9. Skin Segmentation Based on Graph Cuts

    Institute of Scientific and Technical Information of China (English)

    HU Zhilan; WANG Guijin; LIN Xinggang; YAN Hong

    2009-01-01

    Skin segmentation is widely used in many computer vision tasks to improve automated visualiza-tion. This paper presents a graph cuts algorithm to segment arbitrary skin regions from images. The detected face is used to determine the foreground skin seeds and the background non-skin seeds with the color probability distributions for the foreground represented by a single Gaussian model and for the background by a Gaussian mixture model. The probability distribution of the image is used for noise suppression to alle-viate the influence of the background regions having skin-like colors. Finally, the skin is segmented by graph cuts, with the regional parameter y optimally selected to adapt to different images. Tests of the algorithm on many real wodd photographs show that the scheme accurately segments skin regions and is robust against illumination variations, individual skin variations, and cluttered backgrounds.

  10. Measurements on a prototype segmented Clover detector

    CERN Document Server

    Shepherd, S L; Cullen, D M; Appelbe, D E; Simpson, J; Gerl, J; Kaspar, M; Kleinböhl, A; Peter, I; Rejmund, M; Schaffner, H; Schlegel, C; France, G D

    1999-01-01

    The performance of a segmented Clover germanium detector has been measured. The segmented Clover detector is a composite germanium detector, consisting of four individual germanium crystals in the configuration of a four-leaf Clover, housed in a single cryostat. Each crystal is electrically segmented on its outer surface into four quadrants, with separate energy read-outs from nine crystal zones. Signals are also taken from the inner contact of each crystal. This effectively produces a detector with 16 active elements. One of the purposes of this segmentation is to improve the overall spectral resolution when detecting gamma radiation emitted following a nuclear reaction, by minimising Doppler broadening caused by the opening angle subtended by each detector element. Results of the tests with sources and in beam will be presented. The improved granularity of the detector also leads to an improved isolated hit probability compared with an unsegmented Clover detector. (author)

  11. Constrained bidirectional propagation and stroke segmentation

    Energy Technology Data Exchange (ETDEWEB)

    Mori, S; Gillespie, W; Suen, C Y

    1983-03-01

    A new method for decomposing a complex figure into its constituent strokes is described. This method, based on constrained bidirectional propagation, is suitable for parallel processing. Examples of its application to the segmentation of Chinese characters are presented. 9 references.

  12. Neural Scene Segmentation by Oscillatory Correlation

    National Research Council Canada - National Science Library

    Wang, DeLiang

    2000-01-01

    The segmentation of a visual scene into a set of coherent patterns (objects) is a fundamental aspect of perception, which underlies a variety of important tasks such as figure/ground segregation, and scene analysis...

  13. Variational mesh segmentation via quadric surface fitting

    KAUST Repository

    Yan, Dongming

    2012-11-01

    We present a new variational method for mesh segmentation by fitting quadric surfaces. Each component of the resulting segmentation is represented by a general quadric surface (including plane as a special case). A novel energy function is defined to evaluate the quality of the segmentation, which combines both L2 and L2 ,1 metrics from a triangle to a quadric surface. The Lloyd iteration is used to minimize the energy function, which repeatedly interleaves between mesh partition and quadric surface fitting. We also integrate feature-based and simplification-based techniques in the segmentation framework, which greatly improve the performance. The advantages of our algorithm are demonstrated by comparing with the state-of-the-art methods. © 2012 Elsevier Ltd. All rights reserved.

  14. Probabilistic segmentation of remotely sensed images

    NARCIS (Netherlands)

    Gorte, B.

    1998-01-01

    For information extraction from image data to create or update geographic information systems, objects are identified and labeled using an integration of segmentation and classification. This yields geometric and thematic information, respectively.

    Bayesian image

  15. Medical image segmentation using genetic algorithms.

    Science.gov (United States)

    Maulik, Ujjwal

    2009-03-01

    Genetic algorithms (GAs) have been found to be effective in the domain of medical image segmentation, since the problem can often be mapped to one of search in a complex and multimodal landscape. The challenges in medical image segmentation arise due to poor image contrast and artifacts that result in missing or diffuse organ/tissue boundaries. The resulting search space is therefore often noisy with a multitude of local optima. Not only does the genetic algorithmic framework prove to be effective in coming out of local optima, it also brings considerable flexibility into the segmentation procedure. In this paper, an attempt has been made to review the major applications of GAs to the domain of medical image segmentation.

  16. Joint shape segmentation with linear programming

    KAUST Repository

    Huang, Qixing; Koltun, Vladlen; Guibas, Leonidas

    2011-01-01

    program is solved via a linear programming relaxation, using a block coordinate descent procedure that makes the optimization feasible for large databases. We evaluate the presented approach on the Princeton segmentation benchmark and show that joint shape

  17. Variational mesh segmentation via quadric surface fitting

    KAUST Repository

    Yan, Dongming; Wang, Wen Ping; Liu, Yang; Yang, Zhouwang

    2012-01-01

    We present a new variational method for mesh segmentation by fitting quadric surfaces. Each component of the resulting segmentation is represented by a general quadric surface (including plane as a special case). A novel energy function is defined to evaluate the quality of the segmentation, which combines both L2 and L2 ,1 metrics from a triangle to a quadric surface. The Lloyd iteration is used to minimize the energy function, which repeatedly interleaves between mesh partition and quadric surface fitting. We also integrate feature-based and simplification-based techniques in the segmentation framework, which greatly improve the performance. The advantages of our algorithm are demonstrated by comparing with the state-of-the-art methods. © 2012 Elsevier Ltd. All rights reserved.

  18. Pitch Synchronous Segmentation of Speech Signals

    Data.gov (United States)

    National Aeronautics and Space Administration — The Pitch Synchronous Segmentation (PSS) that accelerates speech without changing its fundamental frequency method could be applied and evaluated for use at NASA....

  19. Field Sampling from a Segmented Image

    CSIR Research Space (South Africa)

    Debba, Pravesh

    2008-06-01

    Full Text Available This paper presents a statistical method for deriving the optimal prospective field sampling scheme on a remote sensing image to represent different categories in the field. The iterated conditional modes algorithm (ICM) is used for segmentation...

  20. Retina image–based optic disc segmentation

    Directory of Open Access Journals (Sweden)

    Ching-Lin Wang

    2016-05-01

    Full Text Available The change of optic disc can be used to diagnose many eye diseases, such as glaucoma, diabetic retinopathy and macular degeneration. Moreover, retinal blood vessel pattern is unique for human beings even for identical twins. It is a highly stable pattern in biometric identification. Since optic disc is the beginning of the optic nerve and main blood vessels in retina, it can be used as a reference point of identification. Therefore, optic disc segmentation is an important technique for developing a human identity recognition system and eye disease diagnostic system. This article hence presents an optic disc segmentation method to extract the optic disc from a retina image. The experimental results show that the optic disc segmentation method can give impressive results in segmenting the optic disc from a retina image.

  1. Handwriting segmentation of unconstrained Oriya text

    Indian Academy of Sciences (India)

    Segmentation of handwritten text into lines, words and characters .... We now discuss here some terms relating to water reservoirs that will be used in feature ..... is found. Next, based on the touching position, reservoir base-area points, ...

  2. Mixed raster content segmentation, compression, transmission

    CERN Document Server

    Pavlidis, George

    2017-01-01

    This book presents the main concepts in handling digital images of mixed content, traditionally referenced as mixed raster content (MRC), in two main parts. The first includes introductory chapters covering the scientific and technical background aspects, whereas the second presents a set of research and development approaches to tackle key issues in MRC segmentation, compression and transmission. The book starts with a review of color theory and the mechanism of color vision in humans. In turn, the second chapter reviews data coding and compression methods so as to set the background and demonstrate the complexity involved in dealing with MRC. Chapter three addresses the segmentation of images through an extensive literature review, which highlights the various approaches used to tackle MRC segmentation. The second part of the book focuses on the segmentation of color images for optimized compression, including multi-layered decomposition and representation of MRC and the processes that can be employed to op...

  3. A competition in unsupervised color image segmentation

    Czech Academy of Sciences Publication Activity Database

    Haindl, Michal; Mikeš, Stanislav

    2016-01-01

    Roč. 57, č. 9 (2016), s. 136-151 ISSN 0031-3203 R&D Projects: GA ČR(CZ) GA14-10911S Institutional support: RVO:67985556 Keywords : Unsupervised image segmentation * Segmentation contest * Texture analysis Subject RIV: BD - Theory of Information Impact factor: 4.582, year: 2016 http://library.utia.cas.cz/separaty/2016/RO/haindl-0459179.pdf

  4. Learning Semantic Segmentation with Diverse Supervision

    OpenAIRE

    Ye, Linwei; Liu, Zhi; Wang, Yang

    2018-01-01

    Models based on deep convolutional neural networks (CNN) have significantly improved the performance of semantic segmentation. However, learning these models requires a large amount of training images with pixel-level labels, which are very costly and time-consuming to collect. In this paper, we propose a method for learning CNN-based semantic segmentation models from images with several types of annotations that are available for various computer vision tasks, including image-level labels fo...

  5. Unfolding Implementation in Industrial Market Segmentation

    DEFF Research Database (Denmark)

    Bøjgaard, John; Ellegaard, Chris

    2011-01-01

    to pave the way towards closing this gap. The extent of implementation coverage is assessed and various notions of implementation are identified. Implementation as the task of converting segmentation plans into action (referred to as execution) is identified as a particularly beneficial focus area...... for marketing management. Three key elements and challenges connected to execution of market segmentation are identified — organization, motivation, and adaptation....

  6. Mounting and Alignment of IXO Mirror Segments

    Science.gov (United States)

    Chan, Kai-Wing; Zhang, William; Evans, Tyler; McClelland, Ryan; Hong, Melinda; Mazzarella, James; Saha, Timo; Jalota, Lalit; Olsen, Lawrence; Byron, Glenn

    2010-01-01

    A suspension-mounting scheme is developed for the IXO (International X-ray Observatory) mirror segments in which the figure of the mirror segment is preserved in each stage of mounting. The mirror, first fixed on a thermally compatible strongback, is subsequently transported, aligned and transferred onto its mirror housing. In this paper, we shall outline the requirement, approaches, and recent progress of the suspension mount processes.

  7. Active Mask Segmentation of Fluorescence Microscope Images

    OpenAIRE

    Srinivasa, Gowri; Fickus, Matthew C.; Guo, Yusong; Linstedt, Adam D.; Kovačević, Jelena

    2009-01-01

    We propose a new active mask algorithm for the segmentation of fluorescence microscope images of punctate patterns. It combines the (a) flexibility offered by active-contour methods, (b) speed offered by multiresolution methods, (c) smoothing offered by multiscale methods, and (d) statistical modeling offered by region-growing methods into a fast and accurate segmentation tool. The framework moves from the idea of the “contour” to that of “inside and outside”, or, masks, allowing for easy mul...

  8. Primary Segmental Volvulus Mimicking Ileal Atresia

    Science.gov (United States)

    Rao, Sadashiva; B Shetty, Kishan

    2013-01-01

    Neonatal intestinal volvulus in the absence of malrotation is a rare occurrence and rarer still is the intestinal volvulus in absence of any other predisposing factors. Primary segmental volvulus in neonates is very rare entity, which can have catastrophic outcome if not intervened at appropriate time. We report two such cases, which were preoperatively diagnosed as ileal atresia and intraoperatively revealed to be primary segmental volvulus of the ileum. PMID:26023426

  9. Osmotic and Heat Stress Effects on Segmentation.

    Directory of Open Access Journals (Sweden)

    Julian Weiss

    Full Text Available During vertebrate embryonic development, early skin, muscle, and bone progenitor populations organize into segments known as somites. Defects in this conserved process of segmentation lead to skeletal and muscular deformities, such as congenital scoliosis, a curvature of the spine caused by vertebral defects. Environmental stresses such as hypoxia or heat shock produce segmentation defects, and significantly increase the penetrance and severity of vertebral defects in genetically susceptible individuals. Here we show that a brief exposure to a high osmolarity solution causes reproducible segmentation defects in developing zebrafish (Danio rerio embryos. Both osmotic shock and heat shock produce border defects in a dose-dependent manner, with an increase in both frequency and severity of defects. We also show that osmotic treatment has a delayed effect on somite development, similar to that observed in heat shocked embryos. Our results establish osmotic shock as an alternate experimental model for stress, affecting segmentation in a manner comparable to other known environmental stressors. The similar effects of these two distinct environmental stressors support a model in which a variety of cellular stresses act through a related response pathway that leads to disturbances in the segmentation process.

  10. SVM Pixel Classification on Colour Image Segmentation

    Science.gov (United States)

    Barui, Subhrajit; Latha, S.; Samiappan, Dhanalakshmi; Muthu, P.

    2018-04-01

    The aim of image segmentation is to simplify the representation of an image with the help of cluster pixels into something meaningful to analyze. Segmentation is typically used to locate boundaries and curves in an image, precisely to label every pixel in an image to give each pixel an independent identity. SVM pixel classification on colour image segmentation is the topic highlighted in this paper. It holds useful application in the field of concept based image retrieval, machine vision, medical imaging and object detection. The process is accomplished step by step. At first we need to recognize the type of colour and the texture used as an input to the SVM classifier. These inputs are extracted via local spatial similarity measure model and Steerable filter also known as Gabon Filter. It is then trained by using FCM (Fuzzy C-Means). Both the pixel level information of the image and the ability of the SVM Classifier undergoes some sophisticated algorithm to form the final image. The method has a well developed segmented image and efficiency with respect to increased quality and faster processing of the segmented image compared with the other segmentation methods proposed earlier. One of the latest application result is the Light L16 camera.

  11. Event segmentation ability uniquely predicts event memory.

    Science.gov (United States)

    Sargent, Jesse Q; Zacks, Jeffrey M; Hambrick, David Z; Zacks, Rose T; Kurby, Christopher A; Bailey, Heather R; Eisenberg, Michelle L; Beck, Taylor M

    2013-11-01

    Memory for everyday events plays a central role in tasks of daily living, autobiographical memory, and planning. Event memory depends in part on segmenting ongoing activity into meaningful units. This study examined the relationship between event segmentation and memory in a lifespan sample to answer the following question: Is the ability to segment activity into meaningful events a unique predictor of subsequent memory, or is the relationship between event perception and memory accounted for by general cognitive abilities? Two hundred and eight adults ranging from 20 to 79years old segmented movies of everyday events and attempted to remember the events afterwards. They also completed psychometric ability tests and tests measuring script knowledge for everyday events. Event segmentation and script knowledge both explained unique variance in event memory above and beyond the psychometric measures, and did so as strongly in older as in younger adults. These results suggest that event segmentation is a basic cognitive mechanism, important for memory across the lifespan. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Process Segmentation Typology in Czech Companies

    Directory of Open Access Journals (Sweden)

    Tucek David

    2016-03-01

    Full Text Available This article describes process segmentation typology during business process management implementation in Czech companies. Process typology is important for a manager’s overview of process orientation as well as for a manager’s general understanding of business process management. This article provides insight into a process-oriented organizational structure. The first part analyzes process segmentation typology itself as well as some original results of quantitative research evaluating process segmentation typology in the specific context of Czech company strategies. Widespread data collection was carried out in 2006 and 2013. The analysis of this data showed that managers have more options regarding process segmentation and its selection. In terms of practicality and ease of use, the most frequently used method of process segmentation (managerial, main, and supportive stems directly from the requirements of ISO 9001. Because of ISO 9001:2015, managers must now apply risk planning in relation to the selection of processes that are subjected to process management activities. It is for this fundamental reason that this article focuses on process segmentation typology.

  13. Fold distributions at clover, crystal and segment levels for segmented clover detectors

    International Nuclear Information System (INIS)

    Kshetri, R; Bhattacharya, P

    2014-01-01

    Fold distributions at clover, crystal and segment levels have been extracted for an array of segmented clover detectors for various gamma energies. A simple analysis of the results based on a model independant approach has been presented. For the first time, the clover fold distribution of an array and associated array addback factor have been extracted. We have calculated the percentages of the number of crystals and segments that fire for a full energy peak event

  14. I/O-Efficient Construction of Constrained Delaunay Triangulations

    DEFF Research Database (Denmark)

    Agarwal, Pankaj Kumar; Arge, Lars; Yi, Ke

    2005-01-01

    In this paper, we designed and implemented an I/O-efficient algorithm for constructing constrained Delaunay triangulations. If the number of constraining segments is smaller than the memory size, our algorithm runs in expected O( N B logM/B NB ) I/Os for triangulating N points in the plane, where...

  15. Rational approximation of vertical segments

    Science.gov (United States)

    Salazar Celis, Oliver; Cuyt, Annie; Verdonk, Brigitte

    2007-08-01

    In many applications, observations are prone to imprecise measurements. When constructing a model based on such data, an approximation rather than an interpolation approach is needed. Very often a least squares approximation is used. Here we follow a different approach. A natural way for dealing with uncertainty in the data is by means of an uncertainty interval. We assume that the uncertainty in the independent variables is negligible and that for each observation an uncertainty interval can be given which contains the (unknown) exact value. To approximate such data we look for functions which intersect all uncertainty intervals. In the past this problem has been studied for polynomials, or more generally for functions which are linear in the unknown coefficients. Here we study the problem for a particular class of functions which are nonlinear in the unknown coefficients, namely rational functions. We show how to reduce the problem to a quadratic programming problem with a strictly convex objective function, yielding a unique rational function which intersects all uncertainty intervals and satisfies some additional properties. Compared to rational least squares approximation which reduces to a nonlinear optimization problem where the objective function may have many local minima, this makes the new approach attractive.

  16. Deformable meshes for medical image segmentation accurate automatic segmentation of anatomical structures

    CERN Document Server

    Kainmueller, Dagmar

    2014-01-01

    ? Segmentation of anatomical structures in medical image data is an essential task in clinical practice. Dagmar Kainmueller introduces methods for accurate fully automatic segmentation of anatomical structures in 3D medical image data. The author's core methodological contribution is a novel deformation model that overcomes limitations of state-of-the-art Deformable Surface approaches, hence allowing for accurate segmentation of tip- and ridge-shaped features of anatomical structures. As for practical contributions, she proposes application-specific segmentation pipelines for a range of anatom

  17. Measuring the three process segments of a customer's service experience for an out-patient surgery center.

    Science.gov (United States)

    Wicks, Angela M; Chin, Wynne W

    2008-01-01

    The purpose of this research is to develop an alternative method of measuring out-patient satisfaction where satisfaction is the central construct. The Gap Model operationalized by SERVQUAL is widely used to measure service quality. However, the SERVQUAL instrument only measures expectations (resulting from the pre-process segment of the service experience) and perceptions (resulting from the post-process segment). All three segments should be measured. The lack of proper segmentation and methodological criticisms in the literature motivated this study. A partial least squares (PLS) approach, a form of structural equation modeling, is used to develop a framework to evaluate patient satisfaction in three service process segments: pre-process, process, and post-process service experiences. Results indicate that each process stage mediates subsequent stages, that the process segment is the most important to the patient and that the antecedents have differing impacts on patient satisfaction depending where in the process the antecedent is evaluated. Only one out-patient surgery center was evaluated. Patient satisfaction criteria specific to hospital selection are not included in this study. Results indicate what is important to patients in each service process segment that focus where ambulatory surgery centers should allocate resources. This study is the first to evaluate patient satisfaction with all three process segments.

  18. Semiautomated segmentation of head and neck cancers in 18F-FDG PET scans: A just-enough-interaction approach.

    Science.gov (United States)

    Beichel, Reinhard R; Van Tol, Markus; Ulrich, Ethan J; Bauer, Christian; Chang, Tangel; Plichta, Kristin A; Smith, Brian J; Sunderland, John J; Graham, Michael M; Sonka, Milan; Buatti, John M

    2016-06-01

    The purpose of this work was to develop, validate, and compare a highly computer-aided method for the segmentation of hot lesions in head and neck 18F-FDG PET scans. A semiautomated segmentation method was developed, which transforms the segmentation problem into a graph-based optimization problem. For this purpose, a graph structure around a user-provided approximate lesion centerpoint is constructed and a suitable cost function is derived based on local image statistics. To handle frequently occurring situations that are ambiguous (e.g., lesions adjacent to each other versus lesion with inhomogeneous uptake), several segmentation modes are introduced that adapt the behavior of the base algorithm accordingly. In addition, the authors present approaches for the efficient interactive local and global refinement of initial segmentations that are based on the "just-enough-interaction" principle. For method validation, 60 PET/CT scans from 59 different subjects with 230 head and neck lesions were utilized. All patients had squamous cell carcinoma of the head and neck. A detailed comparison with the current clinically relevant standard manual segmentation approach was performed based on 2760 segmentations produced by three experts. Segmentation accuracy measured by the Dice coefficient of the proposed semiautomated and standard manual segmentation approach was 0.766 and 0.764, respectively. This difference was not statistically significant (p = 0.2145). However, the intra- and interoperator standard deviations were significantly lower for the semiautomated method. In addition, the proposed method was found to be significantly faster and resulted in significantly higher intra- and interoperator segmentation agreement when compared to the manual segmentation approach. Lack of consistency in tumor definition is a critical barrier for radiation treatment targeting as well as for response assessment in clinical trials and in clinical oncology decision-making. The properties

  19. Semiautomated segmentation of head and neck cancers in 18F-FDG PET scans: A just-enough-interaction approach

    Energy Technology Data Exchange (ETDEWEB)

    Beichel, Reinhard R., E-mail: reinhard-beichel@uiowa.edu [Department of Electrical and Computer Engineering, University of Iowa, Iowa City, Iowa 52242 (United States); Iowa Institute for Biomedical Imaging, University of Iowa, Iowa City, Iowa 52242 (United States); Department of Internal Medicine, University of Iowa, Iowa City, Iowa 52242 (United States); Van Tol, Markus; Ulrich, Ethan J.; Bauer, Christian [Department of Electrical and Computer Engineering, University of Iowa, Iowa City, Iowa 52242 (United States); Iowa Institute for Biomedical Imaging, The University of Iowa, Iowa City, Iowa 52242 (United States); Chang, Tangel; Plichta, Kristin A. [Department of Radiation Oncology, University of Iowa, Iowa City, Iowa 52242 (United States); Smith, Brian J. [Department of Biostatistics, University of Iowa, Iowa City, Iowa 52242 (United States); Sunderland, John J.; Graham, Michael M. [Department of Radiology, University of Iowa, Iowa City, Iowa 52242 (United States); Sonka, Milan [Department of Electrical and Computer Engineering, University of Iowa, Iowa City, Iowa 52242 (United States); Department of Radiation Oncology, The University of Iowa, Iowa City, Iowa 52242 (United States); Iowa Institute for Biomedical Imaging, University of Iowa, Iowa City, Iowa 52242 (United States); Buatti, John M. [Department of Radiation Oncology, University of Iowa, Iowa City, Iowa 52242 (United States); Iowa Institute for Biomedical Imaging, University of Iowa, Iowa City, Iowa 52242 (United States)

    2016-06-15

    Purpose: The purpose of this work was to develop, validate, and compare a highly computer-aided method for the segmentation of hot lesions in head and neck 18F-FDG PET scans. Methods: A semiautomated segmentation method was developed, which transforms the segmentation problem into a graph-based optimization problem. For this purpose, a graph structure around a user-provided approximate lesion centerpoint is constructed and a suitable cost function is derived based on local image statistics. To handle frequently occurring situations that are ambiguous (e.g., lesions adjacent to each other versus lesion with inhomogeneous uptake), several segmentation modes are introduced that adapt the behavior of the base algorithm accordingly. In addition, the authors present approaches for the efficient interactive local and global refinement of initial segmentations that are based on the “just-enough-interaction” principle. For method validation, 60 PET/CT scans from 59 different subjects with 230 head and neck lesions were utilized. All patients had squamous cell carcinoma of the head and neck. A detailed comparison with the current clinically relevant standard manual segmentation approach was performed based on 2760 segmentations produced by three experts. Results: Segmentation accuracy measured by the Dice coefficient of the proposed semiautomated and standard manual segmentation approach was 0.766 and 0.764, respectively. This difference was not statistically significant (p = 0.2145). However, the intra- and interoperator standard deviations were significantly lower for the semiautomated method. In addition, the proposed method was found to be significantly faster and resulted in significantly higher intra- and interoperator segmentation agreement when compared to the manual segmentation approach. Conclusions: Lack of consistency in tumor definition is a critical barrier for radiation treatment targeting as well as for response assessment in clinical trials and in

  20. Local Competition-Based Superpixel Segmentation Algorithm in Remote Sensing

    Directory of Open Access Journals (Sweden)

    Jiayin Liu

    2017-06-01

    Full Text Available Remote sensing technologies have been widely applied in urban environments’ monitoring, synthesis and modeling. Incorporating spatial information in perceptually coherent regions, superpixel-based approaches can effectively eliminate the “salt and pepper” phenomenon which is common in pixel-wise approaches. Compared with fixed-size windows, superpixels have adaptive sizes and shapes for different spatial structures. Moreover, superpixel-based algorithms can significantly improve computational efficiency owing to the greatly reduced number of image primitives. Hence, the superpixel algorithm, as a preprocessing technique, is more and more popularly used in remote sensing and many other fields. In this paper, we propose a superpixel segmentation algorithm called Superpixel Segmentation with Local Competition (SSLC, which utilizes a local competition mechanism to construct energy terms and label pixels. The local competition mechanism leads to energy terms locality and relativity, and thus, the proposed algorithm is less sensitive to the diversity of image content and scene layout. Consequently, SSLC could achieve consistent performance in different image regions. In addition, the Probability Density Function (PDF, which is estimated by Kernel Density Estimation (KDE with the Gaussian kernel, is introduced to describe the color distribution of superpixels as a more sophisticated and accurate measure. To reduce computational complexity, a boundary optimization framework is introduced to only handle boundary pixels instead of the whole image. We conduct experiments to benchmark the proposed algorithm with the other state-of-the-art ones on the Berkeley Segmentation Dataset (BSD and remote sensing images. Results demonstrate that the SSLC algorithm yields the best overall performance, while the computation time-efficiency is still competitive.

  1. Local Competition-Based Superpixel Segmentation Algorithm in Remote Sensing.

    Science.gov (United States)

    Liu, Jiayin; Tang, Zhenmin; Cui, Ying; Wu, Guoxing

    2017-06-12

    Remote sensing technologies have been widely applied in urban environments' monitoring, synthesis and modeling. Incorporating spatial information in perceptually coherent regions, superpixel-based approaches can effectively eliminate the "salt and pepper" phenomenon which is common in pixel-wise approaches. Compared with fixed-size windows, superpixels have adaptive sizes and shapes for different spatial structures. Moreover, superpixel-based algorithms can significantly improve computational efficiency owing to the greatly reduced number of image primitives. Hence, the superpixel algorithm, as a preprocessing technique, is more and more popularly used in remote sensing and many other fields. In this paper, we propose a superpixel segmentation algorithm called Superpixel Segmentation with Local Competition (SSLC), which utilizes a local competition mechanism to construct energy terms and label pixels. The local competition mechanism leads to energy terms locality and relativity, and thus, the proposed algorithm is less sensitive to the diversity of image content and scene layout. Consequently, SSLC could achieve consistent performance in different image regions. In addition, the Probability Density Function (PDF), which is estimated by Kernel Density Estimation (KDE) with the Gaussian kernel, is introduced to describe the color distribution of superpixels as a more sophisticated and accurate measure. To reduce computational complexity, a boundary optimization framework is introduced to only handle boundary pixels instead of the whole image. We conduct experiments to benchmark the proposed algorithm with the other state-of-the-art ones on the Berkeley Segmentation Dataset (BSD) and remote sensing images. Results demonstrate that the SSLC algorithm yields the best overall performance, while the computation time-efficiency is still competitive.

  2. Single-segment and double-segment INTACS for post-LASIK ectasia.

    Directory of Open Access Journals (Sweden)

    Hassan Hashemi

    2014-09-01

    Full Text Available The objective of the present study was to compare single segment and double segment INTACS rings in the treatment of post-LASIK ectasia. In this interventional study, 26 eyes with post-LASIK ectasia were assessed. Ectasia was defined as progressive myopia regardless of astigmatism, along with topographic evidence of inferior steepening of the cornea after LASIK. We excluded those with a history of intraocular surgery, certain eye conditions, and immune disorders, as well as monocular, pregnant and lactating patients. A total of 11 eyes had double ring and 15 eyes had single ring implantation. Visual and refractive outcomes were compared with preoperative values based on the number of implanted INTACS rings. Pre and postoperative spherical equivalent were -3.92 and -2.29 diopter (P=0.007. The spherical equivalent decreased by 1 ± 3.2 diopter in the single-segment group and 2.56 ± 1.58 diopter in the double-segment group (P=0.165. Mean preoperative astigmatism was 2.38 ± 1.93 diopter which decreased to 2.14 ± 1.1 diopter after surgery (P=0.508; 0.87 ± 1.98 diopter decrease in the single-segment group and 0.67 ± 1.2 diopter increase in the double-segment group (P=0.025. Nineteen patients (75% gained one or two lines, and only three, who were all in the double-segment group, lost one or two lines of best corrected visual acuity. The spherical equivalent and vision significantly decreased in all patients. In these post-LASIK ectasia patients, the spherical equivalent was corrected better with two segments compared to single segment implantation; nonetheless, the level of astigmatism in the single-segment group was significantly better than that in the double-segment group.

  3. Abdominal multi-organ segmentation from CT images using conditional shape-location and unsupervised intensity priors.

    Science.gov (United States)

    Okada, Toshiyuki; Linguraru, Marius George; Hori, Masatoshi; Summers, Ronald M; Tomiyama, Noriyuki; Sato, Yoshinobu

    2015-12-01

    This paper addresses the automated segmentation of multiple organs in upper abdominal computed tomography (CT) data. The aim of our study is to develop methods to effectively construct the conditional priors and use their prediction power for more accurate segmentation as well as easy adaptation to various imaging conditions in CT images, as observed in clinical practice. We propose a general framework of multi-organ segmentation which effectively incorporates interrelations among multiple organs and easily adapts to various imaging conditions without the need for supervised intensity information. The features of the framework are as follows: (1) A method for modeling conditional shape and location (shape-location) priors, which we call prediction-based priors, is developed to derive accurate priors specific to each subject, which enables the estimation of intensity priors without the need for supervised intensity information. (2) Organ correlation graph is introduced, which defines how the conditional priors are constructed and segmentation processes of multiple organs are executed. In our framework, predictor organs, whose segmentation is sufficiently accurate by using conventional single-organ segmentation methods, are pre-segmented, and the remaining organs are hierarchically segmented using conditional shape-location priors. The proposed framework was evaluated through the segmentation of eight abdominal organs (liver, spleen, left and right kidneys, pancreas, gallbladder, aorta, and inferior vena cava) from 134 CT data from 86 patients obtained under six imaging conditions at two hospitals. The experimental results show the effectiveness of the proposed prediction-based priors and the applicability to various imaging conditions without the need for supervised intensity information. Average Dice coefficients for the liver, spleen, and kidneys were more than 92%, and were around 73% and 67% for the pancreas and gallbladder, respectively. Copyright © 2015

  4. Segmentation algorithm on smartphone dual camera: application to plant organs in the wild

    Science.gov (United States)

    Bertrand, Sarah; Cerutti, Guillaume; Tougne, Laure

    2018-04-01

    In order to identify the species of a tree, the different organs that are the leaves, the bark, the flowers and the fruits, are inspected by botanists. So as to develop an algorithm that identifies automatically the species, we need to extract these objects of interest from their complex natural environment. In this article, we focus on the segmentation of flowers and fruits and we present a new method of segmentation based on an active contour algorithm using two probability maps. The first map is constructed via the dual camera that we can find on the back of the latest smartphones. The second map is made with the help of a multilayer perceptron (MLP). The combination of these two maps to drive the evolution of the object contour allows an efficient segmentation of the organ from a natural background.

  5. Development of a hadron blind detector using a finely segmented pad readout

    Energy Technology Data Exchange (ETDEWEB)

    Kanno, Koki, E-mail: kkanno@post.kek.jp [Department of Physics, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Aoki, Kazuya [High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba-shi, Ibaraki 305-0801 (Japan); Aramaki, Yoki; En' yo, Hideto; Kawama, Daisuke [RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Komatsu, Yusuke; Masumoto, Shinichi [Department of Physics, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Nakai, Wataru [Department of Physics, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Obara, Yuki [Department of Physics, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Ozawa, Kyoichiro; Sekimoto, Michiko [High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba-shi, Ibaraki 305-0801 (Japan); Shibukawa, Takuya [Department of Physics, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Takahashi, Tomonori [Research Center for Nuclear Physics (RCNP), Osaka University, 10-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Watanabe, Yosuke [Department of Physics, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Yokkaichi, Satoshi [RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)

    2016-05-21

    We constructed a hadron blind detector (HBD) using a finely segmented pad readout. The finely segmented pad readout enabled us to adopt an advanced particle identification method which applies a threshold to the number of pad hits in addition to the total amount of collected charge. The responses of the detector to electrons and pions were evaluated using a negatively charged secondary beam at 1.0 GeV/c containing 20% electrons at the J-PARC K1.1BR beam line. We observed 7.3 photoelectrons per incident electron. Using the advanced particle identification method, an electron detection efficiency of 83% was achieved with a pion rejection factor of 120. The method improved the pion rejection by approximately a factor of five, compared to the one which just applies a threshold to the amount of collected charge. The newly introduced finely segmented pad readout was found to be effective in rejecting pions.

  6. Development of a hadron blind detector using a finely segmented pad readout

    International Nuclear Information System (INIS)

    Kanno, Koki; Aoki, Kazuya; Aramaki, Yoki; En'yo, Hideto; Kawama, Daisuke; Komatsu, Yusuke; Masumoto, Shinichi; Nakai, Wataru; Obara, Yuki; Ozawa, Kyoichiro; Sekimoto, Michiko; Shibukawa, Takuya; Takahashi, Tomonori; Watanabe, Yosuke; Yokkaichi, Satoshi

    2016-01-01

    We constructed a hadron blind detector (HBD) using a finely segmented pad readout. The finely segmented pad readout enabled us to adopt an advanced particle identification method which applies a threshold to the number of pad hits in addition to the total amount of collected charge. The responses of the detector to electrons and pions were evaluated using a negatively charged secondary beam at 1.0 GeV/c containing 20% electrons at the J-PARC K1.1BR beam line. We observed 7.3 photoelectrons per incident electron. Using the advanced particle identification method, an electron detection efficiency of 83% was achieved with a pion rejection factor of 120. The method improved the pion rejection by approximately a factor of five, compared to the one which just applies a threshold to the amount of collected charge. The newly introduced finely segmented pad readout was found to be effective in rejecting pions.

  7. A Flux-Pinning Mechanism for Segment Assembly and Alignment

    Science.gov (United States)

    Gersh-Range, Jessica A.; Arnold, William R.; Peck, Mason A.; Stahl, H. Philip

    2011-01-01

    Currently, the most compelling astrophysics questions include how planets and the first stars formed and whether there are protostellar disks that contain large organic molecules. Although answering these questions requires space telescopes with apertures of at least 10 meters, such large primaries are challenging to construct by scaling up previous designs; the limited capacity of a launch vehicle bounds the maximum diameter of a monolithic primary, and beyond a certain size, deployable telescopes cannot fit in current launch vehicle fairings. One potential solution is connecting the primary mirror segments edgewise using flux-pinning mechanisms, which are analogous to non-contacting damped springs. In the baseline design, a flux-pinning mechanism consists of a magnet and a superconductor separated by a predetermined gap, with the damping adjusted by placing aluminum near the interface. Since flux pinning is possible only when the superconductor is cooled below a critical temperature, flux-pinning mechanisms are uniquely suited for cryogenic space telescopes. By placing these mechanisms along the edges of the mirror segments, a primary can be built up over time. Since flux pinning requires no mechanical deployments, the assembly process could be robotic or use some other non-contacting scheme. Advantages of this approach include scalability and passive stability.

  8. Novel whole brain segmentation and volume estimation using quantitative MRI

    Energy Technology Data Exchange (ETDEWEB)

    West, J. [Linkoeping University, Radiation Physics, Department of Medical and Health Sciences, Faculty of Health Sciences, Linkoeping (Sweden); Linkoeping University, Center for Medical Imaging Science and Visualization (CMIV), Linkoeping (Sweden); SyntheticMR AB, Linkoeping (Sweden); Warntjes, J.B.M. [Linkoeping University, Center for Medical Imaging Science and Visualization (CMIV), Linkoeping (Sweden); SyntheticMR AB, Linkoeping (Sweden); Linkoeping University and Department of Clinical Physiology UHL, County Council of Oestergoetland, Clinical Physiology, Department of Medical and Health Sciences, Faculty of Health Sciences, Linkoeping (Sweden); Lundberg, P. [Linkoeping University, Center for Medical Imaging Science and Visualization (CMIV), Linkoeping (Sweden); Linkoeping University and Department of Radiation Physics UHL, County Council of Oestergoetland, Radiation Physics, Department of Medical and Health Sciences, Faculty of Health Sciences, Linkoeping (Sweden); Linkoeping University and Department of Radiology UHL, County Council of Oestergoetland, Radiology, Department of Medical and Health Sciences, Faculty of Health Sciences, Linkoeping (Sweden)

    2012-05-15

    Brain segmentation and volume estimation of grey matter (GM), white matter (WM) and cerebro-spinal fluid (CSF) are important for many neurological applications. Volumetric changes are observed in multiple sclerosis (MS), Alzheimer's disease and dementia, and in normal aging. A novel method is presented to segment brain tissue based on quantitative magnetic resonance imaging (qMRI) of the longitudinal relaxation rate R{sub 1}, the transverse relaxation rate R{sub 2} and the proton density, PD. Previously reported qMRI values for WM, GM and CSF were used to define tissues and a Bloch simulation performed to investigate R{sub 1}, R{sub 2} and PD for tissue mixtures in the presence of noise. Based on the simulations a lookup grid was constructed to relate tissue partial volume to the R{sub 1}-R{sub 2}-PD space. The method was validated in 10 healthy subjects. MRI data were acquired using six resolutions and three geometries. Repeatability for different resolutions was 3.2% for WM, 3.2% for GM, 1.0% for CSF and 2.2% for total brain volume. Repeatability for different geometries was 8.5% for WM, 9.4% for GM, 2.4% for CSF and 2.4% for total brain volume. We propose a new robust qMRI-based approach which we demonstrate in a patient with MS. (orig.)

  9. Novel whole brain segmentation and volume estimation using quantitative MRI

    International Nuclear Information System (INIS)

    West, J.; Warntjes, J.B.M.; Lundberg, P.

    2012-01-01

    Brain segmentation and volume estimation of grey matter (GM), white matter (WM) and cerebro-spinal fluid (CSF) are important for many neurological applications. Volumetric changes are observed in multiple sclerosis (MS), Alzheimer's disease and dementia, and in normal aging. A novel method is presented to segment brain tissue based on quantitative magnetic resonance imaging (qMRI) of the longitudinal relaxation rate R 1 , the transverse relaxation rate R 2 and the proton density, PD. Previously reported qMRI values for WM, GM and CSF were used to define tissues and a Bloch simulation performed to investigate R 1 , R 2 and PD for tissue mixtures in the presence of noise. Based on the simulations a lookup grid was constructed to relate tissue partial volume to the R 1 -R 2 -PD space. The method was validated in 10 healthy subjects. MRI data were acquired using six resolutions and three geometries. Repeatability for different resolutions was 3.2% for WM, 3.2% for GM, 1.0% for CSF and 2.2% for total brain volume. Repeatability for different geometries was 8.5% for WM, 9.4% for GM, 2.4% for CSF and 2.4% for total brain volume. We propose a new robust qMRI-based approach which we demonstrate in a patient with MS. (orig.)

  10. SALIENCY BASED SEGMENTATION OF SATELLITE IMAGES

    Directory of Open Access Journals (Sweden)

    A. Sharma

    2015-03-01

    Full Text Available Saliency gives the way as humans see any image and saliency based segmentation can be eventually helpful in Psychovisual image interpretation. Keeping this in view few saliency models are used along with segmentation algorithm and only the salient segments from image have been extracted. The work is carried out for terrestrial images as well as for satellite images. The methodology used in this work extracts those segments from segmented image which are having higher or equal saliency value than a threshold value. Salient and non salient regions of image become foreground and background respectively and thus image gets separated. For carrying out this work a dataset of terrestrial images and Worldview 2 satellite images (sample data are used. Results show that those saliency models which works better for terrestrial images are not good enough for satellite image in terms of foreground and background separation. Foreground and background separation in terrestrial images is based on salient objects visible on the images whereas in satellite images this separation is based on salient area rather than salient objects.

  11. Exploratory analysis of genomic segmentations with Segtools

    Directory of Open Access Journals (Sweden)

    Buske Orion J

    2011-10-01

    Full Text Available Abstract Background As genome-wide experiments and annotations become more prevalent, researchers increasingly require tools to help interpret data at this scale. Many functional genomics experiments involve partitioning the genome into labeled segments, such that segments sharing the same label exhibit one or more biochemical or functional traits. For example, a collection of ChlP-seq experiments yields a compendium of peaks, each labeled with one or more associated DNA-binding proteins. Similarly, manually or automatically generated annotations of functional genomic elements, including cis-regulatory modules and protein-coding or RNA genes, can also be summarized as genomic segmentations. Results We present a software toolkit called Segtools that simplifies and automates the exploration of genomic segmentations. The software operates as a series of interacting tools, each of which provides one mode of summarization. These various tools can be pipelined and summarized in a single HTML page. We describe the Segtools toolkit and demonstrate its use in interpreting a collection of human histone modification data sets and Plasmodium falciparum local chromatin structure data sets. Conclusions Segtools provides a convenient, powerful means of interpreting a genomic segmentation.

  12. Multidimensional Brain MRI segmentation using graph cuts

    International Nuclear Information System (INIS)

    Lecoeur, Jeremy

    2010-01-01

    This thesis deals with the segmentation of multimodal brain MRIs by graph cuts method. First, we propose a method that utilizes three MRI modalities by merging them. The border information given by the spectral gradient is then challenged by a region information, given by the seeds selected by the user, using a graph cut algorithm. Then, we propose three enhancements of this method. The first consists in finding an optimal spectral space because the spectral gradient is based on natural images and then inadequate for multimodal medical images. This results in a learning based segmentation method. We then explore the automation of the graph cut method. Here, the various pieces of information usually given by the user are inferred from a robust expectation-maximization algorithm. We show the performance of these two enhanced versions on multiple sclerosis lesions. Finally, we integrate atlases for the automatic segmentation of deep brain structures. These three new techniques show the adaptability of our method to various problems. Our different segmentation methods are better than most of nowadays techniques, speaking of computation time or segmentation accuracy. (authors)

  13. Experience with mechanical segmentation of reactor internals

    International Nuclear Information System (INIS)

    Carlson, R.; Hedin, G.

    2003-01-01

    Operating experience from BWE:s world-wide has shown that many plants experience initial cracking of the reactor internals after approximately 20 to 25 years of service life. This ''mid-life crisis'', considering a plant design life of 40 years, is now being addressed by many utilities. Successful resolution of these issues should give many more years of trouble-free operation. Replacement of reactor internals could be, in many cases, the most favourable option to achieve this. The proactive strategy of many utilities to replace internals in a planned way is a market-driven effort to minimize the overall costs for power generation, including time spent for handling contingencies and unplanned outages. Based on technical analyses, knowledge about component market prices and in-house costs, a cost-effective, optimized strategy for inspection, mitigation and replacements can be implemented. Also decommissioning of nuclear plants has become a reality for many utilities as numerous plants worldwide are closed due to age and/or other reasons. These facts address a need for safe, fast and cost-effective methods for segmentation of internals. Westinghouse has over the last years developed methods for segmentation of internals and has also carried out successful segmentation projects. Our experience from the segmentation business for Nordic BWR:s is that the most important parameters to consider when choosing a method and equipment for a segmentation project are: - Safety, - Cost-effectiveness, - Cleanliness, - Reliability. (orig.)

  14. Segmentation and Visualisation of Human Brain Structures

    Energy Technology Data Exchange (ETDEWEB)

    Hult, Roger

    2003-10-01

    In this thesis the focus is mainly on the development of segmentation techniques for human brain structures and of the visualisation of such structures. The images of the brain are both anatomical images (magnet resonance imaging (MRI) and autoradiography) and functional images that show blood flow (functional magnetic imaging (fMRI), positron emission tomography (PET), and single photon emission tomography (SPECT)). When working with anatomical images, the structures segmented are visible as different parts of the brain, e.g. the brain cortex, the hippocampus, or the amygdala. In functional images, the activity or the blood flow that be seen. Grey-level morphology methods are used in the segmentations to make tissue types in the images more homogenous and minimise difficulties with connections to outside tissue. A method for automatic histogram thresholding is also used. Furthermore, there are binary operations such as logic operation between masks and binary morphology operations. The visualisation of the segmented structures uses either surface rendering or volume rendering. For the visualisation of thin structures, surface rendering is the better choice since otherwise some voxels might be missed. It is possible to display activation from a functional image on the surface of a segmented cortex. A new method for autoradiographic images has been developed, which integrates registration, background compensation, and automatic thresholding to get faster and more reliable results than the standard techniques give.

  15. Segmentation and Visualisation of Human Brain Structures

    International Nuclear Information System (INIS)

    Hult, Roger

    2003-01-01

    In this thesis the focus is mainly on the development of segmentation techniques for human brain structures and of the visualisation of such structures. The images of the brain are both anatomical images (magnet resonance imaging (MRI) and autoradiography) and functional images that show blood flow (functional magnetic imaging (fMRI), positron emission tomography (PET), and single photon emission tomography (SPECT)). When working with anatomical images, the structures segmented are visible as different parts of the brain, e.g. the brain cortex, the hippocampus, or the amygdala. In functional images, the activity or the blood flow that be seen. Grey-level morphology methods are used in the segmentations to make tissue types in the images more homogenous and minimise difficulties with connections to outside tissue. A method for automatic histogram thresholding is also used. Furthermore, there are binary operations such as logic operation between masks and binary morphology operations. The visualisation of the segmented structures uses either surface rendering or volume rendering. For the visualisation of thin structures, surface rendering is the better choice since otherwise some voxels might be missed. It is possible to display activation from a functional image on the surface of a segmented cortex. A new method for autoradiographic images has been developed, which integrates registration, background compensation, and automatic thresholding to get faster and more reliable results than the standard techniques give

  16. Compound image segmentation of published biomedical figures.

    Science.gov (United States)

    Li, Pengyuan; Jiang, Xiangying; Kambhamettu, Chandra; Shatkay, Hagit

    2018-04-01

    Images convey essential information in biomedical publications. As such, there is a growing interest within the bio-curation and the bio-databases communities, to store images within publications as evidence for biomedical processes and for experimental results. However, many of the images in biomedical publications are compound images consisting of multiple panels, where each individual panel potentially conveys a different type of information. Segmenting such images into constituent panels is an essential first step toward utilizing images. In this article, we develop a new compound image segmentation system, FigSplit, which is based on Connected Component Analysis. To overcome shortcomings typically manifested by existing methods, we develop a quality assessment step for evaluating and modifying segmentations. Two methods are proposed to re-segment the images if the initial segmentation is inaccurate. Experimental results show the effectiveness of our method compared with other methods. The system is publicly available for use at: https://www.eecis.udel.edu/~compbio/FigSplit. The code is available upon request. shatkay@udel.edu. Supplementary data are available online at Bioinformatics.

  17. Infants generalize representations of statistically segmented words

    Directory of Open Access Journals (Sweden)

    Katharine eGraf Estes

    2012-10-01

    Full Text Available The acoustic variation in language presents learners with a substantial challenge. To learn by tracking statistical regularities in speech, infants must recognize words across tokens that differ based on characteristics such as the speaker’s voice, affect, or the sentence context. Previous statistical learning studies have not investigated how these types of surface form variation affect learning. The present experiments used tasks tailored to two distinct developmental levels to investigate the robustness of statistical learning to variation. Experiment 1 examined statistical word segmentation in 11-month-olds and found that infants can recognize statistically segmented words across a change in the speaker’s voice from segmentation to testing. The direction of infants’ preferences suggests that recognizing words across a voice change is more difficult than recognizing them in a consistent voice. Experiment 2 tested whether 17-month-olds can generalize the output of statistical learning across variation to support word learning. The infants were successful in their generalization; they associated referents with statistically defined words despite a change in voice from segmentation to label learning. Infants’ learning patterns also indicate that they formed representations of across-word syllable sequences during segmentation. Thus, low probability sequences can act as object labels in some conditions. The findings of these experiments suggest that the units that emerge during statistical learning are not perceptually constrained, but rather are robust to naturalistic acoustic variation.

  18. Contour tracing for segmentation of mammographic masses

    International Nuclear Information System (INIS)

    Elter, Matthias; Held, Christian; Wittenberg, Thomas

    2010-01-01

    CADx systems have the potential to support radiologists in the difficult task of discriminating benign and malignant mammographic lesions. The segmentation of mammographic masses from the background tissue is an important module of CADx systems designed for the characterization of mass lesions. In this work, a novel approach to this task is presented. The segmentation is performed by automatically tracing the mass' contour in-between manually provided landmark points defined on the mass' margin. The performance of the proposed approach is compared to the performance of implementations of three state-of-the-art approaches based on region growing and dynamic programming. For an unbiased comparison of the different segmentation approaches, optimal parameters are selected for each approach by means of tenfold cross-validation and a genetic algorithm. Furthermore, segmentation performance is evaluated on a dataset of ROI and ground-truth pairs. The proposed method outperforms the three state-of-the-art methods. The benchmark dataset will be made available with publication of this paper and will be the first publicly available benchmark dataset for mass segmentation.

  19. Poly(ether amide) segmented block copolymers with adipicacid based tetra amide segments

    NARCIS (Netherlands)

    Biemond, G.J.E.; Feijen, Jan; Gaymans, R.J.

    2007-01-01

    Poly(tetramethylene oxide)-based poly(ether ester amide)s with monodisperse tetraamide segments were synthesized. The tetraamide segment was based on adipic acid, terephthalic acid, and hexamethylenediamine. The synthesis method of the copolymers and the influence of the tetraamide concentration,

  20. Market Segmentation in Business Technology Base: The Case of Segmentation of Sparkling

    Directory of Open Access Journals (Sweden)

    Valéria Riscarolli

    2014-08-01

    Full Text Available A common market segmentation premise for products and services rules consumer behavior as the segmentation center piece. Would this be the logic for segmentation used by small technology based companies? In this article we target at determining the principles of market segmentation used by a vitiwinery company, as research object. This company is recognized by its products excellence, either in domestic as well as in the foreign market, among 13 distinct countries. The research method used is a case study, through information from the company’s CEOs and crossed by primary information from observation and formal registries and documents of the company. In this research we look at sparkling wines market segmentation. Main results indicate that the winery studied considers only technological elements as the basis to build a market segment. One may conclude that a market segmentation for this company is based upon technological dominion of sparkling wines production, aligned with a premium-price policy. In the company, directorship believes that as sparkling wines market is still incipient in the country, sparkling wine market segments will form and consolidate after the evolution of consumers tasting preferences, depending on technologies that boost sparkling wines quality. 

  1. ONE SEGMENT OF THE BULGARIAN-ENGLISH PAREMIOLOGICAL CORE

    Directory of Open Access Journals (Sweden)

    KOTOVA M.Y.

    2015-12-01

    Full Text Available The English proverbial parallels of the Russian-Bulgarian paremiological core are analysed in the article. The comparison of current Bulgarian proverbs and their English proverbial parallels is based upon the material of the author’s multi-lingual dictionary and her collection of Bulgarian-Russian proverbial parallels published as a result of her sociolinguistic paremiological experiment from 2003 (on the basis of 100 questionnaires filled by 100 Bulgarian respondents and supported in 2013 with the current Bulgarian contexts from the Bulgarian Internet. The number of 'alive' Bulgarian-English proverbial parallels, constructed from the paremiological questionnaires (pointed out by 70 % - 100 % respondents is 62, the biggest part of which belongs to the proverbial parallels with a similar inner form (35, i.e. the biggest part of the segment of the current Bulgarian-English paremiological core (reflecting the Russian paremiological minimum contains proverbial parallels with a similar inner form.

  2. Dynamics in international market segmentation of new product growth

    NARCIS (Netherlands)

    Lemmens, A.; Croux, C.; Stremersch, S.

    2012-01-01

    Prior international segmentation studies have been static in that they have identified segments that remain stable over time. This paper shows that country segments in new product growth are intrinsically dynamic. We propose a semiparametric hidden Markov model to dynamically segment countries based

  3. Modeling vehicle interior noise exposure dose on freeways: Considering weaving segment designs and engine operation.

    Science.gov (United States)

    Li, Qing; Qiao, Fengxiang; Yu, Lei; Shi, Junqing

    2017-07-05

    Vehicle interior noise functions at the dominant frequencies of 500 Hz below and around 800 Hz, which fall into the bands that may impair hearing. Recent studies demonstrated that freeway commuters are chronically exposed to vehicle interior noise, bearing the risk of hearing impairment. The interior noise evaluation process is mostly conducted in a laboratory environment. The test results and the developed noise models may underestimate or ignore the noise effects from dynamic traffic and road conditions and configuration. However, the interior noise is highly associated with vehicle maneuvering. The vehicle maneuvering on a freeway weaving segment is more complex because of its nature of conflicting areas. This research is intended to explore the risk of the interior noise exposure on freeway weaving segments for freeway commuters and to improve the interior noise estimation by constructing a decision tree learning-based noise exposure dose (NED) model, considering weaving segment designs and engine operation. On-road driving tests were conducted on 12 subjects on State Highway 288 in Houston, Texas. On-board Diagnosis (OBD) II, a smartphone-based roughness app, and a digital sound meter were used to collect vehicle maneuvering and engine information, International Roughness Index, and interior noise levels, respectively. Eleven variables were obtainable from the driving tests, including the length and type of a weaving segment, serving as predictors. The importance of the predictors was estimated by their out-of-bag-permuted predictor delta errors. The hazardous exposure level of the interior noise on weaving segments was quantified to hazard quotient, NED, and daily noise exposure level, respectively. Results showed that the risk of hearing impairment on freeway is acceptable; the interior noise level is the most sensitive to the pavement roughness and is subject to freeway configuration and traffic conditions. The constructed NED model shows high predictive

  4. Construction dust amelioration techniques.

    Science.gov (United States)

    2012-04-01

    Dust produced on seasonal road construction sites in Alaska is both a traffic safety and environmental concern. Dust emanating from : unpaved road surfaces during construction severely reduces visibility and impacts stopping sight distance, and contr...

  5. Improving concrete overlay construction.

    Science.gov (United States)

    2010-03-01

    Several road construction projects involving concrete overlays at the state and county levels in Iowa in 2009 were studied for : construction techniques and methods. The projects that were evaluated consisted of sites in four Iowa counties: Osceola, ...

  6. Construction project management handbook.

    Science.gov (United States)

    2012-03-01

    The purpose of the FTA Construction Project Management Handbook is to provide guidelines for use by public transit agencies (Agen-cies) undertaking substantial construction projects, either for the first time or with little prior experience with cons...

  7. Visualization of construction engineering

    International Nuclear Information System (INIS)

    Okada, Hisako; Miura, Jun

    2000-01-01

    It is required for nuclear power plant construction to reduce construction cost and shorten construction period. An early and accurate construction planning including schedule coordination among the companies has recently become more important and it is possible to obtain necessary information for construction planning in early stage. In this situation, we have been developing a visualization system for construction engineering for nuclear power plants. This system has an interface with the existing Plant Layout 3D-CAD system and consists of three sub systems: (1) Scheduling and simulation system, (2) Yard planning system and (3) Scaffolding planning system. This paper describes overview of this system. This visualization system is very helpful for construction engineers to easily understand situation and environment around installation area, to easily plan a work sequence and confirm the planned schedule, and it is also effective for customers and workers to understand the planning. As a result, this visualization system enables safety and high quality construction. (author)

  8. Construction Sector (NAICS 23)

    Science.gov (United States)

    Find environmental regulatory information for the construction sector, including the construction of buildings or engineering projects. This includes RCRA information for hazardous waste, refrigeration compliance, asbestos, effluent guidelines & lead laws

  9. Organizational Behaviour in Construction

    DEFF Research Database (Denmark)

    Kreiner, Kristian

    2013-01-01

    Review of: Organizational Behaviour in Construction / Anthony Walker (Wiley-Blackwell,2011 336 pp)......Review of: Organizational Behaviour in Construction / Anthony Walker (Wiley-Blackwell,2011 336 pp)...

  10. USAID Construction Assessment

    Data.gov (United States)

    US Agency for International Development — The USAID construction assessment is a survey of the character, scope, value and management of construction activities supported by USAID during the period from June...

  11. Validating MEDIQUAL Constructs

    Science.gov (United States)

    Lee, Sang-Gun; Min, Jae H.

    In this paper, we validate MEDIQUAL constructs through the different media users in help desk service. In previous research, only two end-users' constructs were used: assurance and responsiveness. In this paper, we extend MEDIQUAL constructs to include reliability, empathy, assurance, tangibles, and responsiveness, which are based on the SERVQUAL theory. The results suggest that: 1) five MEDIQUAL constructs are validated through the factor analysis. That is, importance of the constructs have relatively high correlations between measures of the same construct using different methods and low correlations between measures of the constructs that are expected to differ; and 2) five MEDIQUAL constructs are statistically significant on media users' satisfaction in help desk service by regression analysis.

  12. Why segmentation matters: experience-driven segmentation errors impair “morpheme” learning

    Science.gov (United States)

    Finn, Amy S.; Hudson Kam, Carla L.

    2015-01-01

    We ask whether an adult learner’s knowledge of their native language impedes statistical learning in a new language beyond just word segmentation (as previously shown). In particular, we examine the impact of native-language word-form phonotactics on learners’ ability to segment words into their component morphemes and learn phonologically triggered variation of morphemes. We find that learning is impaired when words and component morphemes are structured to conflict with a learner’s native-language phonotactic system, but not when native-language phonotactics do not conflict with morpheme boundaries in the artificial language. A learner’s native-language knowledge can therefore have a cascading impact affecting word segmentation and the morphological variation that relies upon proper segmentation. These results show that getting word segmentation right early in learning is deeply important for learning other aspects of language, even those (morphology) that are known to pose a great difficulty for adult language learners. PMID:25730305

  13. Why segmentation matters: Experience-driven segmentation errors impair "morpheme" learning.

    Science.gov (United States)

    Finn, Amy S; Hudson Kam, Carla L

    2015-09-01

    We ask whether an adult learner's knowledge of their native language impedes statistical learning in a new language beyond just word segmentation (as previously shown). In particular, we examine the impact of native-language word-form phonotactics on learners' ability to segment words into their component morphemes and learn phonologically triggered variation of morphemes. We find that learning is impaired when words and component morphemes are structured to conflict with a learner's native-language phonotactic system, but not when native-language phonotactics do not conflict with morpheme boundaries in the artificial language. A learner's native-language knowledge can therefore have a cascading impact affecting word segmentation and the morphological variation that relies upon proper segmentation. These results show that getting word segmentation right early in learning is deeply important for learning other aspects of language, even those (morphology) that are known to pose a great difficulty for adult language learners. (c) 2015 APA, all rights reserved).

  14. Rhythm-based segmentation of Popular Chinese Music

    DEFF Research Database (Denmark)

    Jensen, Karl Kristoffer

    2005-01-01

    We present a new method to segment popular music based on rhythm. By computing a shortest path based on the self-similarity matrix calculated from a model of rhythm, segmenting boundaries are found along the di- agonal of the matrix. The cost of a new segment is opti- mized by matching manual...... and automatic segment boundaries. We compile a small song database of 21 randomly selected popular Chinese songs which come from Chinese Mainland, Taiwan and Hong Kong. The segmenting results on the small corpus show that 78% manual segmentation points are detected and 74% auto- matic segmentation points...

  15. Underwater Object Segmentation Based on Optical Features

    Directory of Open Access Journals (Sweden)

    Zhe Chen

    2018-01-01

    Full Text Available Underwater optical environments are seriously affected by various optical inputs, such as artificial light, sky light, and ambient scattered light. The latter two can block underwater object segmentation tasks, since they inhibit the emergence of objects of interest and distort image information, while artificial light can contribute to segmentation. Artificial light often focuses on the object of interest, and, therefore, we can initially identify the region of target objects if the collimation of artificial light is recognized. Based on this concept, we propose an optical feature extraction, calculation, and decision method to identify the collimated region of artificial light as a candidate object region. Then, the second phase employs a level set method to segment the objects of interest within the candidate region. This two-phase structure largely removes background noise and highlights the outline of underwater objects. We test the performance of the method with diverse underwater datasets, demonstrating that it outperforms previous methods.

  16. Nuclear propulsion apparatus with alternate reactor segments

    International Nuclear Information System (INIS)

    Szekely, T.

    1979-01-01

    Nuclear propulsion apparatus comprising: (a) means for compressing incoming air; (b) nuclear fission reactor means for heating said air; (c) means for expanding a portion of the heated air to drive said compressing means; (d) said nuclear fission reactor means being divided into a plurality of radially extending segments; (e) means for directing a portion of the compressed air for heating through alternate segments of said reactor means and another portion of the compressed air for heating through the remaining segments of said reactor means; and (f) means for further expanding the heated air from said drive means and the remaining heated air from said reactor means through nozzle means to effect reactive thrust on said apparatus. 12 claims

  17. Segmental blood pressure after total hip replacement

    DEFF Research Database (Denmark)

    Gebuhr, Peter Henrik; Soelberg, M; Henriksen, Jens Henrik Sahl

    1992-01-01

    Twenty-nine patients due to have a total hip replacement had their systemic systolic and segmental blood pressures measured prior to operation and 1 and 6 weeks postoperatively. No patients had signs of ischemia. The segmental blood pressure was measured at the ankle and at the toes. A significant...... drop was found in all pressures 1 week postoperatively. The decrease followed the systemic pressure and was restored to normal after 6 weeks. In a group of six patients with preoperatively decreased ankle pressure, a significant transient further decrease in the ankle-toe gradient pressure was found...... on the operated side. None of the patients had symptoms from the lowered pressure. We conclude that in patients without signs of ischemia, the postoperative segmental pressure decrease is reversible and therefore not dangerous....

  18. Active mask segmentation of fluorescence microscope images.

    Science.gov (United States)

    Srinivasa, Gowri; Fickus, Matthew C; Guo, Yusong; Linstedt, Adam D; Kovacević, Jelena

    2009-08-01

    We propose a new active mask algorithm for the segmentation of fluorescence microscope images of punctate patterns. It combines the (a) flexibility offered by active-contour methods, (b) speed offered by multiresolution methods, (c) smoothing offered by multiscale methods, and (d) statistical modeling offered by region-growing methods into a fast and accurate segmentation tool. The framework moves from the idea of the "contour" to that of "inside and outside," or masks, allowing for easy multidimensional segmentation. It adapts to the topology of the image through the use of multiple masks. The algorithm is almost invariant under initialization, allowing for random initialization, and uses a few easily tunable parameters. Experiments show that the active mask algorithm matches the ground truth well and outperforms the algorithm widely used in fluorescence microscopy, seeded watershed, both qualitatively, as well as quantitatively.

  19. Natural color image segmentation using integrated mechanism

    Institute of Scientific and Technical Information of China (English)

    Jie Xu (徐杰); Pengfei Shi (施鹏飞)

    2003-01-01

    A new method for natural color image segmentation using integrated mechanism is proposed in this paper.Edges are first detected in term of the high phase congruency in the gray-level image. K-mean cluster is used to label long edge lines based on the global color information to estimate roughly the distribution of objects in the image, while short ones are merged based on their positions and local color differences to eliminate the negative affection caused by texture or other trivial features in image. Region growing technique is employed to achieve final segmentation results. The proposed method unifies edges, whole and local color distributions, as well as spatial information to solve the natural image segmentation problem.The feasibility and effectiveness of this method have been demonstrated by various experiments.

  20. Continuation of Sets of Constrained Orbit Segments

    DEFF Research Database (Denmark)

    Schilder, Frank; Brøns, Morten; Chamoun, George Chaouki

    Sets of constrained orbit segments of time continuous flows are collections of trajectories that represent a whole or parts of an invariant set. A non-trivial but simple example is a homoclinic orbit. A typical representation of this set consists of an equilibrium point of the flow and a trajectory...... that starts close and returns close to this fixed point within finite time. More complicated examples are hybrid periodic orbits of piecewise smooth systems or quasi-periodic invariant tori. Even though it is possible to define generalised two-point boundary value problems for computing sets of constrained...... orbit segments, this is very disadvantageous in practice. In this talk we will present an algorithm that allows the efficient continuation of sets of constrained orbit segments together with the solution of the full variational problem....

  1. CERES: A new cerebellum lobule segmentation method.

    Science.gov (United States)

    Romero, Jose E; Coupé, Pierrick; Giraud, Rémi; Ta, Vinh-Thong; Fonov, Vladimir; Park, Min Tae M; Chakravarty, M Mallar; Voineskos, Aristotle N; Manjón, Jose V

    2017-02-15

    The human cerebellum is involved in language, motor tasks and cognitive processes such as attention or emotional processing. Therefore, an automatic and accurate segmentation method is highly desirable to measure and understand the cerebellum role in normal and pathological brain development. In this work, we propose a patch-based multi-atlas segmentation tool called CERES (CEREbellum Segmentation) that is able to automatically parcellate the cerebellum lobules. The proposed method works with standard resolution magnetic resonance T1-weighted images and uses the Optimized PatchMatch algorithm to speed up the patch matching process. The proposed method was compared with related recent state-of-the-art methods showing competitive results in both accuracy (average DICE of 0.7729) and execution time (around 5 minutes). Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Video-based noncooperative iris image segmentation.

    Science.gov (United States)

    Du, Yingzi; Arslanturk, Emrah; Zhou, Zhi; Belcher, Craig

    2011-02-01

    In this paper, we propose a video-based noncooperative iris image segmentation scheme that incorporates a quality filter to quickly eliminate images without an eye, employs a coarse-to-fine segmentation scheme to improve the overall efficiency, uses a direct least squares fitting of ellipses method to model the deformed pupil and limbic boundaries, and develops a window gradient-based method to remove noise in the iris region. A remote iris acquisition system is set up to collect noncooperative iris video images. An objective method is used to quantitatively evaluate the accuracy of the segmentation results. The experimental results demonstrate the effectiveness of this method. The proposed method would make noncooperative iris recognition or iris surveillance possible.

  3. Interaction features for prediction of perceptual segmentation

    DEFF Research Database (Denmark)

    Hartmann, Martin; Lartillot, Olivier; Toiviainen, Petri

    2017-01-01

    As music unfolds in time, structure is recognised and understood by listeners, regardless of their level of musical expertise. A number of studies have found spectral and tonal changes to quite successfully model boundaries between structural sections. However, the effects of musical expertise...... and experimental task on computational modelling of structure are not yet well understood. These issues need to be addressed to better understand how listeners perceive the structure of music and to improve automatic segmentation algorithms. In this study, computational prediction of segmentation by listeners...... was investigated for six musical stimuli via a real-time task and an annotation (non real-time) task. The proposed approach involved computation of novelty curve interaction features and a prediction model of perceptual segmentation boundary density. We found that, compared to non-musicians’, musicians...

  4. SIDES - Segment Interconnect Diagnostic Expert System

    International Nuclear Information System (INIS)

    Booth, A.W.; Forster, R.; Gustafsson, L.; Ho, N.

    1989-01-01

    It is well known that the FASTBUS Segment Interconnect (SI) provides a communication path between two otherwise independent, asynchronous bus segments. The SI is probably the most important module in any FASTBUS data acquisition network since it's failure to function can cause whole segments of the network to be inaccessible and sometimes inoperable. This paper describes SIDES, an intelligent program designed to diagnose SI's both in situ as they operate in a data acquisition network, and in the laboratory in an acceptance/repair environment. The paper discusses important issues such as knowledge acquisition; extracting knowledge from human experts and other knowledge sources. SIDES can benefit high energy physics experiments, where SI problems can be diagnosed and solved more quickly. Equipment pool technicians can also benefit from SIDES, first by decreasing the number of SI's erroneously turned in for repair, and secondly as SIDES acts as an intelligent assistant to the technician in the diagnosis and repair process

  5. Heterotic string construction

    International Nuclear Information System (INIS)

    Schellekens, A.N.

    1989-01-01

    In this paper an elementary introduction to the principles of four-dimensional string construction will be given. Although the emphasis is on lattice constructions, almost all results have further, and often quite straightforward generalizations to other constructions. Since heterotic strings look phenomenologically more promising than type-II theories the authors only consider the former, although everything can easily be generalized to type-II theories. Some additional aspects of lattice constructions are discussed, and an extensive review can be found

  6. Parallel fuzzy connected image segmentation on GPU.

    Science.gov (United States)

    Zhuge, Ying; Cao, Yong; Udupa, Jayaram K; Miller, Robert W

    2011-07-01

    Image segmentation techniques using fuzzy connectedness (FC) principles have shown their effectiveness in segmenting a variety of objects in several large applications. However, one challenge in these algorithms has been their excessive computational requirements when processing large image datasets. Nowadays, commodity graphics hardware provides a highly parallel computing environment. In this paper, the authors present a parallel fuzzy connected image segmentation algorithm implementation on NVIDIA's compute unified device Architecture (CUDA) platform for segmenting medical image data sets. In the FC algorithm, there are two major computational tasks: (i) computing the fuzzy affinity relations and (ii) computing the fuzzy connectedness relations. These two tasks are implemented as CUDA kernels and executed on GPU. A dramatic improvement in speed for both tasks is achieved as a result. Our experiments based on three data sets of small, medium, and large data size demonstrate the efficiency of the parallel algorithm, which achieves a speed-up factor of 24.4x, 18.1x, and 10.3x, correspondingly, for the three data sets on the NVIDIA Tesla C1060 over the implementation of the algorithm on CPU, and takes 0.25, 0.72, and 15.04 s, correspondingly, for the three data sets. The authors developed a parallel algorithm of the widely used fuzzy connected image segmentation method on the NVIDIA GPUs, which are far more cost- and speed-effective than both cluster of workstations and multiprocessing systems. A near-interactive speed of segmentation has been achieved, even for the large data set.

  7. Safety in construction industry

    International Nuclear Information System (INIS)

    Khan, A.M.

    1979-01-01

    Causative factors of accidents in construction industry in the context of experience of construction work of the Rajasthan Atomic Power Project are enumerated. The aspect of accident cost - direct and indirect - is discussed briefly. Setting up of a safety set-up at construction sites is emphasized and principles which should guide the accident prevention programme are spelt out. (M.G.B.)

  8. CT identification of bronchopulmonary segments: 50 normal subjects

    International Nuclear Information System (INIS)

    Osbourne, D.; Vock, P.; Godwin, J.D.; Silverman, P.M.

    1984-01-01

    A systematic evaluation of the fissures, segmental bronchi and arteries, bronchopulmonary segments, and peripheral pulmonary parenchyma was made from computed tomographic (CT) scans of 50 patients with normal chest radiographs. Seventy percent of the segmental bronchi and 76% of the segmental arteries were identified. Arteries could be traced to their sixth- and seventh-order branches; their orientation to the plane of the CT section allowed gross identification and localization of bronchopulmonary segments

  9. Segmentation of Lung Structures in CT

    DEFF Research Database (Denmark)

    Lo, Pechin Chien Pau

    This thesis proposes and evaluates new algorithms for segmenting various lung structures in computed tomography (CT) images, namely the lungs, airway trees and vessel trees. The main objective of these algorithms is to facilitate a better platform for studying Chronic Obstructive Pulmonary Disease......, 200 randomly selected CT scans were manually evaluated by medical experts, and only negligible or minor errors were found in nine scans. The proposed algorithm has been used to study how changes in smoking behavior affect CT based emphysema quantification. The algorithms for segmenting the airway...

  10. Coupled Shape Model Segmentation in Pig Carcasses

    DEFF Research Database (Denmark)

    Hansen, Mads Fogtmann; Larsen, Rasmus; Ersbøll, Bjarne Kjær

    2006-01-01

    levels inside the outline as well as in a narrow band outside the outline. The maximum a posteriori estimate of the outline is found by gradient descent optimization. In order to segment a group of mutually dependent objects we propose 2 procedures, 1) the objects are found sequentially by conditioning...... the initialization of the next search from already found objects; 2) all objects are found simultaneously and a repelling force is introduced in order to avoid overlap between outlines in the solution. The methods are applied to segmentation of cross sections of muscles in slices of CT scans of pig backs for quality...

  11. Self-assembling segmented coiled tubing

    Science.gov (United States)

    Raymond, David W.

    2016-09-27

    Self-assembling segmented coiled tubing is a concept that allows the strength of thick-wall rigid pipe, and the flexibility of thin-wall tubing, to be realized in a single design. The primary use is for a drillstring tubular, but it has potential for other applications requiring transmission of mechanical loads (forces and torques) through an initially coiled tubular. The concept uses a spring-loaded spherical `ball-and-socket` type joint to interconnect two or more short, rigid segments of pipe. Use of an optional snap ring allows the joint to be permanently made, in a `self-assembling` manner.

  12. Segmentation of the Indian photovoltaic market

    International Nuclear Information System (INIS)

    Srinivasan, S.

    2005-01-01

    This paper provides an analytical framework studying the actors, networks and institutions and examines the evolution of the Indian Solar Photovoltaic (PV) Market. Different market segments, along the lines of demand and supply of PV equipment, i.e. on the basis of geography, end-use application, subsidy policy and other financing mechanisms, are detailed. The objective of this effort is to identify segments that require special attention from policy makers, donors and the Ministry of Non-Conventional Energy Sources. The paper also discusses the evolution of the commercial PV market in certain parts of the country and trends in the maturity of the market. (author)

  13. Unsupervised information extraction by text segmentation

    CERN Document Server

    Cortez, Eli

    2013-01-01

    A new unsupervised approach to the problem of Information Extraction by Text Segmentation (IETS) is proposed, implemented and evaluated herein. The authors' approach relies on information available on pre-existing data to learn how to associate segments in the input string with attributes of a given domain relying on a very effective set of content-based features. The effectiveness of the content-based features is also exploited to directly learn from test data structure-based features, with no previous human-driven training, a feature unique to the presented approach. Based on the approach, a

  14. Innovative visualization and segmentation approaches for telemedicine

    Science.gov (United States)

    Nguyen, D.; Roehrig, Hans; Borders, Marisa H.; Fitzpatrick, Kimberly A.; Roveda, Janet

    2014-09-01

    In health care applications, we obtain, manage, store and communicate using high quality, large volume of image data through integrated devices. In this paper we propose several promising methods that can assist physicians in image data process and communication. We design a new semi-automated segmentation approach for radiological images, such as CT and MRI to clearly identify the areas of interest. This approach combines the advantages from both the region-based method and boundary-based methods. It has three key steps compose: coarse segmentation by using fuzzy affinity and homogeneity operator, image division and reclassification using the Voronoi Diagram, and refining boundary lines using the level set model.

  15. Strategies for regular segmented reductions on GPU

    DEFF Research Database (Denmark)

    Larsen, Rasmus Wriedt; Henriksen, Troels

    2017-01-01

    We present and evaluate an implementation technique for regular segmented reductions on GPUs. Existing techniques tend to be either consistent in performance but relatively inefficient in absolute terms, or optimised for specific workloads and thereby exhibiting bad performance for certain input...... is in the context of the Futhark compiler, the implementation technique is applicable to any library or language that has a need for segmented reductions. We evaluate the technique on four microbenchmarks, two of which we also compare to implementations in the CUB library for GPU programming, as well as on two...

  16. Actinic Granuloma with Focal Segmental Glomerulosclerosis

    Directory of Open Access Journals (Sweden)

    Ruedee Phasukthaworn

    2016-02-01

    Full Text Available Actinic granuloma is an uncommon granulomatous disease, characterized by annular erythematous plaque with central clearing predominately located on sun-damaged skin. The pathogenesis is not well understood, ultraviolet radiation is recognized as precipitating factor. We report a case of a 52-year-old woman who presented with asymptomatic annular erythematous plaques on the forehead and both cheeks persisting for 2 years. The clinical presentation and histopathologic findings support the diagnosis of actinic granuloma. During that period of time, she also developed focal segmental glomerulosclerosis. The association between actinic granuloma and focal segmental glomerulosclerosis needs to be clarified by further studies.

  17. Segmentation and informality in Vietnam : a survey of the literature: country case study on labour market segmentation

    OpenAIRE

    Cling, Jean-Pierre; Razafindrakoto, Mireille; Roubaud, François

    2014-01-01

    Labour market segmentation is usually defined as the division of the labour markets into separate sub-markets or segments, distinguished by different characteristics and behavioural rules (incomes, contracts, etc.). The economic debate on the segmentation issue has been focusing in developed countries, and especially in Europe, on contractual segmentation and dualism.

  18. Performance of an open-source heart sound segmentation algorithm on eight independent databases.

    Science.gov (United States)

    Liu, Chengyu; Springer, David; Clifford, Gari D

    2017-08-01

    Heart sound segmentation is a prerequisite step for the automatic analysis of heart sound signals, facilitating the subsequent identification and classification of pathological events. Recently, hidden Markov model-based algorithms have received increased interest due to their robustness in processing noisy recordings. In this study we aim to evaluate the performance of the recently published logistic regression based hidden semi-Markov model (HSMM) heart sound segmentation method, by using a wider variety of independently acquired data of varying quality. Firstly, we constructed a systematic evaluation scheme based on a new collection of heart sound databases, which we assembled for the PhysioNet/CinC Challenge 2016. This collection includes a total of more than 120 000 s of heart sounds recorded from 1297 subjects (including both healthy subjects and cardiovascular patients) and comprises eight independent heart sound databases sourced from multiple independent research groups around the world. Then, the HSMM-based segmentation method was evaluated using the assembled eight databases. The common evaluation metrics of sensitivity, specificity, accuracy, as well as the [Formula: see text] measure were used. In addition, the effect of varying the tolerance window for determining a correct segmentation was evaluated. The results confirm the high accuracy of the HSMM-based algorithm on a separate test dataset comprised of 102 306 heart sounds. An average [Formula: see text] score of 98.5% for segmenting S1 and systole intervals and 97.2% for segmenting S2 and diastole intervals were observed. The [Formula: see text] score was shown to increases with an increases in the tolerance window size, as expected. The high segmentation accuracy of the HSMM-based algorithm on a large database confirmed the algorithm's effectiveness. The described evaluation framework, combined with the largest collection of open access heart sound data, provides essential resources for

  19. Design of large size segmented GEM foils and Drift PCB for CBM MUCH

    International Nuclear Information System (INIS)

    Saini, J.; Dubey, A.K.; Chattopadhyay, S.

    2016-01-01

    Triple GEM (Gas Electron Multiplier), sector shaped detectors will be used for Muon tracking in the Compressed Baryonic Matter (CBM) experiment at Anti-proton Ion Research (FAIR) facility at Darmstadt, Germany. The sizes of the detectors modules in the Muon Chambers (MUCH) are of the order of 1 meter with active area of about 75cms. Progressive pad geometry is chosen for the readout from these detectors. In construction of these chambers, three GEM foils are stacked on top of each other in a 3/2/2/2 gap configuration. The GEM foils are double layered copper clad 50μm thin Kapton foil. Each GEM foil has millions of holes on it. Foils of large surface area are prone to damages due to discharges owing to the high capacitance of the foil. Hence, these foils have their top surfaces divided into segments of about 100 sq.cm. Further segmentation may be necessary when there are high rate requirements, as in the case of CBM. For the GEM foils of CBM MUCH, a 24 segment layout has been adopted. Short-circuit in any of the GEM-holes will make entire foil un-usable. To reduce such occurrences, segment to segment isolation using opto-coupler in series with the GEM-foil segments has been introduced. Hence, a novel design for GEM chamber drift-PCB and foils has been made. In this scheme, each segment is powered and controlled individually. At the same time, the design takes into account, the space constraints, not only in x-y plane, but also in the z, due to compact assembly of MUCH detector layers

  20. Development and Implementation of a Corriedale Ovine Brain Atlas for Use in Atlas-Based Segmentation.

    Directory of Open Access Journals (Sweden)

    Kishan Andre Liyanage

    Full Text Available Segmentation is the process of partitioning an image into subdivisions and can be applied to medical images to isolate anatomical or pathological areas for further analysis. This process can be done manually or automated by the use of image processing computer packages. Atlas-based segmentation automates this process by the use of a pre-labelled template and a registration algorithm. We developed an ovine brain atlas that can be used as a model for neurological conditions such as Parkinson's disease and focal epilepsy. 17 female Corriedale ovine brains were imaged in-vivo in a 1.5T (low-resolution MRI scanner. 13 of the low-resolution images were combined using a template construction algorithm to form a low-resolution template. The template was labelled to form an atlas and tested by comparing manual with atlas-based segmentations against the remaining four low-resolution images. The comparisons were in the form of similarity metrics used in previous segmentation research. Dice Similarity Coefficients were utilised to determine the degree of overlap between eight independent, manual and atlas-based segmentations, with values ranging from 0 (no overlap to 1 (complete overlap. For 7 of these 8 segmented areas, we achieved a Dice Similarity Coefficient of 0.5-0.8. The amygdala was difficult to segment due to its variable location and similar intensity to surrounding tissues resulting in Dice Coefficients of 0.0-0.2. We developed a low resolution ovine brain atlas with eight clinically relevant areas labelled. This brain atlas performed comparably to prior human atlases described in the literature and to intra-observer error providing an atlas that can be used to guide further research using ovine brains as a model and is hosted online for public access.

  1. Improved dynamic-programming-based algorithms for segmentation of masses in mammograms

    International Nuclear Information System (INIS)

    Dominguez, Alfonso Rojas; Nandi, Asoke K.

    2007-01-01

    In this paper, two new boundary tracing algorithms for segmentation of breast masses are presented. These new algorithms are based on the dynamic programming-based boundary tracing (DPBT) algorithm proposed in Timp and Karssemeijer, [S. Timp and N. Karssemeijer, Med. Phys. 31, 958-971 (2004)] The DPBT algorithm contains two main steps: (1) construction of a local cost function, and (2) application of dynamic programming to the selection of the optimal boundary based on the local cost function. The validity of some assumptions used in the design of the DPBT algorithm is tested in this paper using a set of 349 mammographic images. Based on the results of the tests, modifications to the computation of the local cost function have been designed and have resulted in the Improved-DPBT (IDPBT) algorithm. A procedure for the dynamic selection of the strength of the components of the local cost function is presented that makes these parameters independent of the image dataset. Incorporation of this dynamic selection procedure has produced another new algorithm which we have called ID 2 PBT. Methods for the determination of some other parameters of the DPBT algorithm that were not covered in the original paper are presented as well. The merits of the new IDPBT and ID 2 PBT algorithms are demonstrated experimentally by comparison against the DPBT algorithm. The segmentation results are evaluated with base on the area overlap measure and other segmentation metrics. Both of the new algorithms outperform the original DPBT; the improvements in the algorithms performance are more noticeable around the values of the segmentation metrics corresponding to the highest segmentation accuracy, i.e., the new algorithms produce more optimally segmented regions, rather than a pronounced increase in the average quality of all the segmented regions

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

    Science.gov (United States)

    Subudhi, Priyambada; Mukhopadhyay, Susanta

    2018-03-01

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

  3. Interactive-cut: Real-time feedback segmentation for translational research.

    Science.gov (United States)

    Egger, Jan; Lüddemann, Tobias; Schwarzenberg, Robert; Freisleben, Bernd; Nimsky, Christopher

    2014-06-01

    In this contribution, a scale-invariant image segmentation algorithm is introduced that "wraps" the algorithm's parameters for the user by its interactive behavior, avoiding the definition of "arbitrary" numbers that the user cannot really understand. Therefore, we designed a specific graph-based segmentation method that only requires a single seed-point inside the target-structure from the user and is thus particularly suitable for immediate processing and interactive, real-time adjustments by the user. In addition, color or gray value information that is needed for the approach can be automatically extracted around the user-defined seed point. Furthermore, the graph is constructed in such a way, so that a polynomial-time mincut computation can provide the segmentation result within a second on an up-to-date computer. The algorithm presented here has been evaluated with fixed seed points on 2D and 3D medical image data, such as brain tumors, cerebral aneurysms and vertebral bodies. Direct comparison of the obtained automatic segmentation results with costlier, manual slice-by-slice segmentations performed by trained physicians, suggest a strong medical relevance of this interactive approach. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Hierarchical graph-based segmentation for extracting road networks from high-resolution satellite images

    Science.gov (United States)

    Alshehhi, Rasha; Marpu, Prashanth Reddy

    2017-04-01

    Extraction of road networks in urban areas from remotely sensed imagery plays an important role in many urban applications (e.g. road navigation, geometric correction of urban remote sensing images, updating geographic information systems, etc.). It is normally difficult to accurately differentiate road from its background due to the complex geometry of the buildings and the acquisition geometry of the sensor. In this paper, we present a new method for extracting roads from high-resolution imagery based on hierarchical graph-based image segmentation. The proposed method consists of: 1. Extracting features (e.g., using Gabor and morphological filtering) to enhance the contrast between road and non-road pixels, 2. Graph-based segmentation consisting of (i) Constructing a graph representation of the image based on initial segmentation and (ii) Hierarchical merging and splitting of image segments based on color and shape features, and 3. Post-processing to remove irregularities in the extracted road segments. Experiments are conducted on three challenging datasets of high-resolution images to demonstrate the proposed method and compare with other similar approaches. The results demonstrate the validity and superior performance of the proposed method for road extraction in urban areas.

  5. a Super Voxel-Based Riemannian Graph for Multi Scale Segmentation of LIDAR Point Clouds

    Science.gov (United States)

    Li, Minglei

    2018-04-01

    Automatically segmenting LiDAR points into respective independent partitions has become a topic of great importance in photogrammetry, remote sensing and computer vision. In this paper, we cast the problem of point cloud segmentation as a graph optimization problem by constructing a Riemannian graph. The scale space of the observed scene is explored by an octree-based over-segmentation with different depths. The over-segmentation produces many super voxels which restrict the structure of the scene and will be used as nodes of the graph. The Kruskal coordinates are used to compute edge weights that are proportional to the geodesic distance between nodes. Then we compute the edge-weight matrix in which the elements reflect the sectional curvatures associated with the geodesic paths between super voxel nodes on the scene surface. The final segmentation results are generated by clustering similar super voxels and cutting off the weak edges in the graph. The performance of this method was evaluated on LiDAR point clouds for both indoor and outdoor scenes. Additionally, extensive comparisons to state of the art techniques show that our algorithm outperforms on many metrics.

  6. Asphalt Pavement Pothole Detection and Segmentation Based on Wavelet Energy Field

    Directory of Open Access Journals (Sweden)

    Penghui Wang

    2017-01-01

    Full Text Available Potholes are one type of pavement surface distresses whose assessment is essential for developing road network maintenance strategies. Existing methods for automatic pothole detection either rely on expensive and high-maintenance equipment or could not segment the pothole accurately. In this paper, an asphalt pavement pothole detection and segmentation method based on energy field is put forward. The proposed method mainly includes two processes. Firstly, the wavelet energy field of the pavement image is constructed to detect the pothole by morphological processing and geometric criterions. Secondly, the detected pothole is segmented by Markov random field model and the pothole edge is extracted accurately. This methodology has been implemented in a MATLAB prototype, trained, and tested on 120 pavement images. The results show that it can effectively distinguish potholes from cracks, patches, greasy dirt, shadows, and manhole covers and accurately segment the pothole. For pothole detection, the method reaches an overall accuracy of 86.7%, with 83.3% precision and 87.5% recall. For pothole segmentation, the overlap degree between the extracted pothole region and the original pothole region is mostly more than 85%, which accounts for 88.6% of the total detected pavement pothole images.

  7. Impact of freeway weaving segment design on light-duty vehicle exhaust emissions.

    Science.gov (United States)

    Li, Qing; Qiao, Fengxiang; Yu, Lei; Chen, Shuyan; Li, Tiezhu

    2018-06-01

    data set as well as in the validation data set, with the R values of 0.91 and 0.90, respectively. Existing emission models usually rely on vehicle operation information to compute a generalized emission result, regardless of road configuration. In practice, while driving through a weaving segment, drivers are inclined to perform erratic maneuvers, such as hard braking and hard acceleration due to the complex weaving maneuver required. As a result, the exhaust emissions within a weaving segment vary from those on a basic segment. This research proposes to involve road configuration, in terms of the type and length of a weaving segment, in constructing an emission nonlinear model, which significantly improves emission estimations at a microscopic level.

  8. Dynamic Post-Earthquake Image Segmentation with an Adaptive Spectral-Spatial Descriptor

    Directory of Open Access Journals (Sweden)

    Genyun Sun

    2017-08-01

    Full Text Available The region merging algorithm is a widely used segmentation technique for very high resolution (VHR remote sensing images. However, the segmentation of post-earthquake VHR images is more difficult due to the complexity of these images, especially high intra-class and low inter-class variability among damage objects. Herein two key issues must be resolved: the first is to find an appropriate descriptor to measure the similarity of two adjacent regions since they exhibit high complexity among the diverse damage objects, such as landslides, debris flow, and collapsed buildings. The other is how to solve over-segmentation and under-segmentation problems, which are commonly encountered with conventional merging strategies due to their strong dependence on local information. To tackle these two issues, an adaptive dynamic region merging approach (ADRM is introduced, which combines an adaptive spectral-spatial descriptor and a dynamic merging strategy to adapt to the changes of merging regions for successfully detecting objects scattered globally in a post-earthquake image. In the new descriptor, the spectral similarity and spatial similarity of any two adjacent regions are automatically combined to measure their similarity. Accordingly, the new descriptor offers adaptive semantic descriptions for geo-objects and thus is capable of characterizing different damage objects. Besides, in the dynamic region merging strategy, the adaptive spectral-spatial descriptor is embedded in the defined testing order and combined with graph models to construct a dynamic merging strategy. The new strategy can find the global optimal merging order and ensures that the most similar regions are merged at first. With combination of the two strategies, ADRM can identify spatially scattered objects and alleviates the phenomenon of over-segmentation and under-segmentation. The performance of ADRM has been evaluated by comparing with four state-of-the-art segmentation methods

  9. Sustainable construction: construction and demolition waste reconsidered.

    Science.gov (United States)

    del Río Merino, Mercedes; Izquierdo Gracia, Pilar; Weis Azevedo, Isabel Salto

    2010-02-01

    Construction activity in Europe has increased substantially in the past decade. Likewise, there has also been a commensurate rise in the generation of construction and demolition waste (C&DW). This, together with the fact that in many European countries the rate of recycling and reuse of C&DW is still quite low has engendered a serious environmental problem and a motivation to develop strategies and management plans to solve it. Due to its composition, there is a significant potential to reuse and/or recycle C&DW, and thereby, contribute to improving the sustainability of construction and development, but practical procedures are not yet widely known or practiced in the construction industry. This article (a) summarizes the different applications that are presently practiced to optimize the recovery and/or application of C&DW for reuse, and (b) proposes various measures and strategies to improve the processing of this waste. The authors suggest that to enhance environmental effectiveness, a conscious and comprehensive C&DW management plan should be implemented in each jurisdiction. More precisely, this study presents a holistic approach towards C&DW management, through which environmental benefits can be achieved through the application of new construction methods that can contribute to sustainable growth.

  10. TPX tokamak construction management

    International Nuclear Information System (INIS)

    Knutson, D.; Kungl, D.; Seidel, P.; Halfast, C.

    1995-01-01

    A construction management contract normally involves the acquisition of a construction management firm to assist in the design, planning, budget conformance, and coordination of the construction effort. In addition the construction management firm acts as an agent in the awarding of lower tier contracts. The TPX Tokamak Construction Management (TCM) approach differs in that the construction management firm is also directly responsible for the assembly and installation of the tokamak including the design and fabrication of all tooling required for assembly. The Systems Integration Support (SIS) contractor is responsible for the architect-engineering design of ancillary systems, such as heating and cooling, buildings, modifications and site improvements, and a variety of electrical requirements, including switchyards and >4kV power distribution. The TCM will be responsible for the procurement of materials and the installation of the ancillary systems, which can either be performed directly by the TCM or subcontracted to a lower tier subcontractor. Assurance that the TPX tokamak is properly assembled and ready for operation when turned over to the operations team is the primary focus of the construction management effort. To accomplish this a disciplined constructability program will be instituted. The constructability effort will involve the effective and timely integration of construction expertise into the planning, component design, and field operations. Although individual component design groups will provide liaison during the machine assembly operations, the construction management team is responsible for assembly

  11. Towards green construction

    International Nuclear Information System (INIS)

    Bajracharya, Bijaya B.; Shrestha, Prasanna M.

    2000-01-01

    Sustainability is the key to any development works. In the operation phase, hydro power is the most sustainable form of energy. However construction activities for the same power station are usually far from being green. The popular myth is that construction activity converts green into grey. Despite this popular myth, construction of a hydro power project in Nepal has made the project area greener than earlier during the construction phase itself. Choice of construction technology, appropriate level of environmental impact assessment, monitoring of environmental parameters along side the construction progress followed by mitigation at the right time; launching community development programmes side by side, having environmental specification in contractual documents and self-reliance to fulfill environmental obligations by contractors itself are the key factors in the environmental management within the construction activities. The main conclusions in the paper is the need to change the way to think about the project constraints

  12. How engineering facilitates construction

    International Nuclear Information System (INIS)

    Bailey, D.T.

    1976-01-01

    During a recent survey, construction personnel at jobsites were asked, ''what are the ten most unwanted construction problems.'' One reoccurring answer was design/construction incompatibility. In fact, many designs were impractical from a construction point of view. The reasons for this problem can be identified: Once construction begins, engineering is under intense pressure to issue new drawings to allow work to progress according to schedule. Other reasons may be the relative inexperience of the design personnel in construction, changes in design criteria and delays in receipt of supplier or client information. A description is presented of ways to solve this problem by obtaining construction expertise and input into the various phases and products of the engineering work

  13. Lung segment geometry study: simulation of largest possible tumours that fit into bronchopulmonary segments.

    Science.gov (United States)

    Welter, S; Stöcker, C; Dicken, V; Kühl, H; Krass, S; Stamatis, G

    2012-03-01

    Segmental resection in stage I non-small cell lung cancer (NSCLC) has been well described and is considered to have similar survival rates as lobectomy but with increased rates of local tumour recurrence due to inadequate parenchymal margins. In consequence, today segmentectomy is only performed when the tumour is smaller than 2 cm. Three-dimensional reconstructions from 11 thin-slice CT scans of bronchopulmonary segments were generated, and virtual spherical tumours were placed over the segments, respecting all segmental borders. As a next step, virtual parenchymal safety margins of 2 cm and 3 cm were subtracted and the size of the remaining tumour calculated. The maximum tumour diameters with a 30-mm parenchymal safety margin ranged from 26.1 mm in right-sided segments 7 + 8 to 59.8 mm in the left apical segments 1-3. Using a three-dimensional reconstruction of lung CT scans, we demonstrated that segmentectomy or resection of segmental groups should be feasible with adequate margins, even for larger tumours in selected cases. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  14. Effects of Armature Winding Segmentation with Multiple Converters on the Short Circuit Torque of 10-MW Superconducting Wind Turbine Generators

    DEFF Research Database (Denmark)

    Liu, Dong; Polinder, Henk; Abrahamsen, Asger Bech

    2017-01-01

    Superconducting synchronous generators (SCSGs) are drawing more attention in large direct-drive wind turbine applications. Despite low weight and compactness, the short circuit torque of an SCSG may be too high for wind turbine constructions due to a large magnetic air gap of an SCSG. This paper...... aims at assessing the effects of armature winding segmentation on reducing the short circuit torque of 10-MW SCSGs. A concept of armature winding segmentation with multiple power electronic converters is presented. Four SCSG designs using different topologies are examined. Results show that armature...... winding segmentation effectively reduce the short circuit torque in all the four SCSG designs when one segment is shorted at the terminal....

  15. Segmented detector for recoil neutrons in the p(γ, n)π+ reaction

    International Nuclear Information System (INIS)

    Korkmaz, E.; O'Rielly, G.V.; Hutcheon, D.A.; Feldman, G.; Jordan, D.; Kolb, N.R.; Pywell, R.E.; Retzlaff, G.A.; Sawatzky, B.D.; Skopik, D.M.; Vogt, J.M.; Cairns, E.; Giesen, U.; Holm, L.; Opper, A.K.; Rozon, F.M.; Soukup, J.

    1999-01-01

    A segmented neutron detector has been constructed and used for recoil neutron (6-13 MeV) measurements of the reaction γp→nπ + very close to threshold. BC-505 liquid scintillator was used to allow pulse shape discrimination between neutrons and photons. A measurement of the absolute efficiency of the detector was performed using stopped pions in the reaction π - p→nγ. Results of the efficiency calibration are compared to a Monte Carlo simulation. (author)

  16. A large-acceptance Bragg curve spectrometer with a longitudinal electric field and a segmented anode

    International Nuclear Information System (INIS)

    Farrar, K.A.; Hasan, A.T.; Prosser, F.W.; Sanders, S.J.; Henderson, D.J.

    1994-01-01

    A large-acceptance Bragg curve spectrometer with a longitudinal electron collection field and a segmented anode has been constructed and tested. The effects on the charge resolution of the entrance angle and entrance position of the incident particle have been studied. Simulations have been done in order to isolate the contribution to the overall detector performance of the signal-shaping electronics from that of the intrinsic design of the detector. ((orig.))

  17. Detection and correction of false segmental duplications caused by genome mis-assembly

    Science.gov (United States)

    2010-01-01

    Diploid genomes with divergent chromosomes present special problems for assembly software as two copies of especially polymorphic regions may be mistakenly constructed, creating the appearance of a recent segmental duplication. We developed a method for identifying such false duplications and applied it to four vertebrate genomes. For each genome, we corrected mis-assemblies, improved estimates of the amount of duplicated sequence, and recovered polymorphisms between the sequenced chromosomes. PMID:20219098

  18. Simulating Deformations of MR Brain Images for Validation of Atlas-based Segmentation and Registration Algorithms

    OpenAIRE

    Xue, Zhong; Shen, Dinggang; Karacali, Bilge; Stern, Joshua; Rottenberg, David; Davatzikos, Christos

    2006-01-01

    Simulated deformations and images can act as the gold standard for evaluating various template-based image segmentation and registration algorithms. Traditional deformable simulation methods, such as the use of analytic deformation fields or the displacement of landmarks followed by some form of interpolation, are often unable to construct rich (complex) and/or realistic deformations of anatomical organs. This paper presents new methods aiming to automatically simulate realistic inter- and in...

  19. ℓ1/2-norm regularized nonnegative low-rank and sparse affinity graph for remote sensing image segmentation

    Science.gov (United States)

    Tian, Shu; Zhang, Ye; Yan, Yiming; Su, Nan

    2016-10-01

    Segmentation of real-world remote sensing images is a challenge due to the complex texture information with high heterogeneity. Thus, graph-based image segmentation methods have been attracting great attention in the field of remote sensing. However, most of the traditional graph-based approaches fail to capture the intrinsic structure of the feature space and are sensitive to noises. A ℓ-norm regularization-based graph segmentation method is proposed to segment remote sensing images. First, we use the occlusion of the random texture model (ORTM) to extract the local histogram features. Then, a ℓ-norm regularized low-rank and sparse representation (LNNLRS) is implemented to construct a ℓ-regularized nonnegative low-rank and sparse graph (LNNLRS-graph), by the union of feature subspaces. Moreover, the LNNLRS-graph has a high ability to discriminate the manifold intrinsic structure of highly homogeneous texture information. Meanwhile, the LNNLRS representation takes advantage of the low-rank and sparse characteristics to remove the noises and corrupted data. Last, we introduce the LNNLRS-graph into the graph regularization nonnegative matrix factorization to enhance the segmentation accuracy. The experimental results using remote sensing images show that when compared to five state-of-the-art image segmentation methods, the proposed method achieves more accurate segmentation results.

  20. Assignment of simian rotavirus SA11 temperature-sensitive mutant groups B and E to genome segments

    International Nuclear Information System (INIS)

    Gombold, J.L.; Estes, M.K.; Ramig, R.F.

    1985-01-01

    Recombinant (reassortant) viruses were selected from crosses between temperature-sensitive (ts) mutants of simian rotavirus SA11 and wild-type human rotavirus Wa. The double-stranded genome RNAs of the reassortants were examined by electrophoresis in Tris-glycine-buffered polyacrylamide gels and by dot hybridization with a cloned DNA probe for genome segment 2. Analysis of replacements of genome segments in the reassortants allowed construction of a map correlating genome segments providing functions interchangeable between SA11 and Wa. The reassortants revealed a functional correspondence in order of increasing electrophoretic mobility of genome segments. Analysis of the parental origin of genome segments in ts+ SA11/Wa reassortants derived from the crosses SA11 tsB(339) X Wa and SA11 tsE(1400) X Wa revealed that the group B lesion of tsB(339) was located on genome segment 3 and the group E lesion of tsE(1400) was on segment 8

  1. Assignment of simian rotavirus SA11 temperature-sensitive mutant groups B and E to genome segments

    Energy Technology Data Exchange (ETDEWEB)

    Gombold, J.L.; Estes, M.K.; Ramig, R.F.

    1985-05-01

    Recombinant (reassortant) viruses were selected from crosses between temperature-sensitive (ts) mutants of simian rotavirus SA11 and wild-type human rotavirus Wa. The double-stranded genome RNAs of the reassortants were examined by electrophoresis in Tris-glycine-buffered polyacrylamide gels and by dot hybridization with a cloned DNA probe for genome segment 2. Analysis of replacements of genome segments in the reassortants allowed construction of a map correlating genome segments providing functions interchangeable between SA11 and Wa. The reassortants revealed a functional correspondence in order of increasing electrophoretic mobility of genome segments. Analysis of the parental origin of genome segments in ts+ SA11/Wa reassortants derived from the crosses SA11 tsB(339) X Wa and SA11 tsE(1400) X Wa revealed that the group B lesion of tsB(339) was located on genome segment 3 and the group E lesion of tsE(1400) was on segment 8.

  2. Translocations used to generate chromosome segment duplications ...

    Indian Academy of Sciences (India)

    a duplication (Dp) of the translocated segment and four inviable (white, W) ascospores with .... of this work, namely, the definition of breakpoint junction sequences of 12 ..... then our results would place supercontig 10.9 in distal. LG VIR. A third ...

  3. Optical Character Recognition Using Active Contour Segmentation

    Directory of Open Access Journals (Sweden)

    Nabeel Oudah

    2018-01-01

    Full Text Available Document analysis of images snapped by camera is a growing challenge. These photos are often poor-quality compound images, composed of various objects and text; this makes automatic analysis complicated. OCR is one of the image processing techniques which is used to perform automatic identification of texts. Existing image processing techniques need to manage many parameters in order to clearly recognize the text in such pictures. Segmentation is regarded one of these essential parameters. This paper discusses the accuracy of segmentation process and its effect over the recognition process. According to the proposed method, the images were firstly filtered using the wiener filter then the active contour algorithm could be applied in the segmentation process. The Tesseract OCR Engine was selected in order to evaluate the performance and identification accuracy of the proposed method. The results showed that a more accurate segmentation process shall lead to a more accurate recognition results. The rate of recognition accuracy was 0.95 for the proposed algorithm compared with 0.85 for the Tesseract OCR Engine.

  4. Multichannel shopper segments and their covariates

    NARCIS (Netherlands)

    Konus, U.; Verhoef, P.C.; Neslin, S.A.

    2008-01-01

    The proliferation of channels has created new challenges for research, including understanding how consumers may be segmented with respect to their information search and purchase behavior in multichannel environment. This research considers shopping a dynamic process that consists of search and

  5. Vessel-guided airway tree segmentation

    DEFF Research Database (Denmark)

    Lo, Pechin Chien Pau; Sporring, Jon; Ashraf, Haseem

    2010-01-01

    This paper presents a method for airway tree segmentation that uses a combination of a trained airway appearance model, vessel and airway orientation information, and region growing. We propose a voxel classification approach for the appearance model, which uses a classifier that is trained to di...

  6. A mechanical perspective on vertebral segmentation

    NARCIS (Netherlands)

    Truskinovsky, L.; Vitale, G.; Smit, T.H.

    2014-01-01

    Segmentation is a characteristic feature of the vertebrate body plan. The prevailing paradigm explaining its origin is the 'clock and wave-front' model, which assumes that the interaction of a molecular oscillator (clock) with a traveling gradient of morphogens (wave) pre-defines spatial

  7. Segmentation of elongated structures in medical images

    NARCIS (Netherlands)

    Staal, Jozef Johannes

    2004-01-01

    The research described in this thesis concerns the automatic detection, recognition and segmentation of elongated structures in medical images. For this purpose techniques have been developed to detect subdimensional pointsets (e.g. ridges, edges) in images of arbitrary dimension. These

  8. Multichannel Shopper Segments and Their Covariates

    NARCIS (Netherlands)

    Konus, Umut; Verhoef, Peter C.; Neslin, Scott A.

    2008-01-01

    The proliferation of channels has created new challenges for research, including understanding how consumers may be segmented with respect to their information search and purchase behavior in multichannel environment. This research considers shopping a dynamic process that consists of search and

  9. Segmental mode of neural patterning in sipuncula

    DEFF Research Database (Denmark)

    Kristof, Alen; Wollesen, Tim; Wanninger, Andreas

    2008-01-01

    Recent molecular phylogenetic analyses suggest a close relationship between two worm-shaped phyla, the nonsegmented Sipuncula (peanut worms) and the segmented Annelida (e.g., earthworms and polychaetes) [1-5]. The striking differences in their bodyplans are exemplified by the annelids' paired...

  10. Segmentation of users of social networking websites

    NARCIS (Netherlands)

    Lorenzo-Romero, C.; Alarcon-del-Amo, M.d.C.; Constantinides, Efthymios

    2012-01-01

    The typology of networked consumers in The Netherlands presented in this study, was based on an online survey and obtained using latent segmentation analysis. This approach is based on the frequency with which users perform different activities, their sociodemographic variables, social networking

  11. Segmentation and Classification of Burn Color Images

    Science.gov (United States)

    2001-10-25

    SEGMENTATION AND CLASSIFICATION OF BURN COLOR IMAGES Begoña Acha1, Carmen Serrano1, Laura Roa2 1Área de Teoría de la Señal y Comunicaciones ...2000, Las Vegas (USA), pp. 411-415. [21] G. Wyszecki and W.S. Stiles, Color Science: Concepts and Methods, Quantitative Data and Formulae (New

  12. Segmentation by watersheds : definition and parallel implementation

    NARCIS (Netherlands)

    Roerdink, Jos B.T.M.; Meijster, Arnold

    1997-01-01

    The watershed algorithm is a method for image segmentation widely used in the area of mathematical morphology. In this paper we first address the problem of how to define watersheds. It is pointed out that various existing definitions are not equivalent. In particular we explain the differences

  13. Strategy-Based Segmentation of Industrial Markets

    NARCIS (Netherlands)

    Verhallen, Theo M.M.; Frambach, Ruud T.; Prabhu, Jaideep

    Segmentation of industrial markets is typically based on observable characteristics of firms such as their location and size. However, such variables have been found to be poor predictors of industrial buying behavior. To improve the effectiveness and power of existing approaches to industrial

  14. Identifying spatial segments in international markets

    NARCIS (Netherlands)

    Ter Hofstede, F; Wedel, M; Steenkamp, JBEM

    2002-01-01

    The identification of geographic target markets is critical to the success of companies that are expanding internationally. Country borders have traditionally been used to delineate such target markets, resulting in accessible segments and cost efficient entry strategies. However, at present such

  15. Segmentation and classification of biological objects

    DEFF Research Database (Denmark)

    Schultz, Nette

    1995-01-01

    The present thesis is on segmentation and classification of biological objects using statistical methods. It is based on case studies dealing with different kinds of pork meat images, and we introduce appropriate statistical methods to solve the tasks in the case studies. The case studies concern...

  16. Language-universal constraints on speech segmentation

    NARCIS (Netherlands)

    Norris, D.; McQueen, J.M.; Cutler, A.; Butterfield, S.; Kearns, R.K.

    2001-01-01

    Two word-spotting experiments are reported that examine whether the Possible-Word Constraint (PWC; Norris, McQueen, Cutler & Butterfield, 1997) is a language-specific or language-universal strategy for the segmentation of continuous speech. The PWC disfavors parses which leave an impossible residue

  17. Word segmentation with universal prosodic cues.

    Science.gov (United States)

    Endress, Ansgar D; Hauser, Marc D

    2010-09-01

    When listening to speech from one's native language, words seem to be well separated from one another, like beads on a string. When listening to a foreign language, in contrast, words seem almost impossible to extract, as if there was only one bead on the same string. This contrast reveals that there are language-specific cues to segmentation. The puzzle, however, is that infants must be endowed with a language-independent mechanism for segmentation, as they ultimately solve the segmentation problem for any native language. Here, we approach the acquisition problem by asking whether there are language-independent cues to segmentation that might be available to even adult learners who have already acquired a native language. We show that adult learners recognize words in connected speech when only prosodic cues to word-boundaries are given from languages unfamiliar to the participants. In both artificial and natural speech, adult English speakers, with no prior exposure to the test languages, readily recognized words in natural languages with critically different prosodic patterns, including French, Turkish and Hungarian. We suggest that, even though languages differ in their sound structures, they carry universal prosodic characteristics. Further, these language-invariant prosodic cues provide a universally accessible mechanism for finding words in connected speech. These cues may enable infants to start acquiring words in any language even before they are fine-tuned to the sound structure of their native language. Copyright © 2010. Published by Elsevier Inc.

  18. Laser Truss Sensor for Segmented Telescope Phasing

    Science.gov (United States)

    Liu, Duncan T.; Lay, Oliver P.; Azizi, Alireza; Erlig, Herman; Dorsky, Leonard I.; Asbury, Cheryl G.; Zhao, Feng

    2011-01-01

    A paper describes the laser truss sensor (LTS) for detecting piston motion between two adjacent telescope segment edges. LTS is formed by two point-to-point laser metrology gauges in a crossed geometry. A high-resolution (distribution can be optimized using the range-gated metrology (RGM) approach.

  19. Wide-band segmented power distribution networks

    NARCIS (Netherlands)

    Tereshchenko, O.V.; Buesink, Frederik Johannes Karel; Leferink, Frank Bernardus Johannes

    2013-01-01

    This paper discusses a novel design of Power Distribution Network (PDN). By physical structuring of the power plane into repetitive symmetrical and asymmetrical segments of varying size, suppression of the propagation of unwanted noise throughout the PDN over a wide frequency range is achieved.

  20. Automatic liver volume segmentation and fibrosis classification

    Science.gov (United States)

    Bal, Evgeny; Klang, Eyal; Amitai, Michal; Greenspan, Hayit

    2018-02-01

    In this work, we present an automatic method for liver segmentation and fibrosis classification in liver computed-tomography (CT) portal phase scans. The input is a full abdomen CT scan with an unknown number of slices, and the output is a liver volume segmentation mask and a fibrosis grade. A multi-stage analysis scheme is applied to each scan, including: volume segmentation, texture features extraction and SVM based classification. Data contains portal phase CT examinations from 80 patients, taken with different scanners. Each examination has a matching Fibroscan grade. The dataset was subdivided into two groups: first group contains healthy cases and mild fibrosis, second group contains moderate fibrosis, severe fibrosis and cirrhosis. Using our automated algorithm, we achieved an average dice index of 0.93 ± 0.05 for segmentation and a sensitivity of 0.92 and specificity of 0.81for classification. To the best of our knowledge, this is a first end to end automatic framework for liver fibrosis classification; an approach that, once validated, can have a great potential value in the clinic.

  1. Skeleton-based Hierarchical Shape Segmentation

    NARCIS (Netherlands)

    Reniers, Dennie; Telea, Alexandru

    2007-01-01

    We present an effective framework for segmenting 3D shapes into meaningful components using the curve skeleton. Our algorithm identifies a number of critical points on the curve skeleton, either fully automatically as the junctions of the curve skeleton, or based on user input. We use these points

  2. Improving sequence segmentation learning by predicting trigrams

    NARCIS (Netherlands)

    van den Bosch, A.; Daelemans, W.; Dagan, I.; Gildea, D.

    2005-01-01

    Symbolic machine-learning classifiers are known to suffer from near-sightedness when performing sequence segmentation (chunking) tasks in natural language processing: without special architectural additions they are oblivious of the decisions they made earlier when making new ones. We introduce a

  3. Analysis of prestressed concrete wall segments

    International Nuclear Information System (INIS)

    Koziak, B.D.P.; Murray, D.W.

    1979-06-01

    An iterative numerical technique for analysing the biaxial response of reinforced and prestressed concrete wall segments subject to combinations of prestressing, creep, temperature and live loads is presented. Two concrete constitutive relations are available for this analysis. The first is a uniaxially bilinear model with a tension cut-off. The second is a nonlinear biaxial relation incorporating equivalent uniaxial strains to remove the Poissons's ratio effect under biaxial loading. Predictions from both the bilinear and nonlinear model are compared with observations from experimental wall segments tested in tension. The nonlinear model results are shown to be close to those of the test segments, while the bilinear results are good up to cracking. Further comparisons are made between the nonlinear analysis using constant membrane force-moment ratios, constant membrane force-curvature ratios, and a nonlinear finite difference analysis of a test containment structure. Neither nonlinear analysis could predict the reponse of every wall segment within the structure, but the constant membrane force-moment analysis provided lower bound results. (author)

  4. A toolbox for multiple sclerosis lesion segmentation

    Energy Technology Data Exchange (ETDEWEB)

    Roura, Eloy; Oliver, Arnau; Valverde, Sergi; Llado, Xavier [University of Girona, Computer Vision and Robotics Group, Girona (Spain); Cabezas, Mariano; Pareto, Deborah; Rovira, Alex [Vall d' Hebron University Hospital, Magnetic Resonance Unit, Dept. of Radiology, Barcelona (Spain); Vilanova, Joan C. [Girona Magnetic Resonance Center, Girona (Spain); Ramio-Torrenta, Lluis [Dr. Josep Trueta University Hospital, Institut d' Investigacio Biomedica de Girona, Multiple Sclerosis and Neuroimmunology Unit, Girona (Spain)

    2015-10-15

    Lesion segmentation plays an important role in the diagnosis and follow-up of multiple sclerosis (MS). This task is very time-consuming and subject to intra- and inter-rater variability. In this paper, we present a new tool for automated MS lesion segmentation using T1w and fluid-attenuated inversion recovery (FLAIR) images. Our approach is based on two main steps, initial brain tissue segmentation according to the gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) performed in T1w images, followed by a second step where the lesions are segmented as outliers to the normal apparent GM brain tissue on the FLAIR image. The tool has been validated using data from more than 100 MS patients acquired with different scanners and at different magnetic field strengths. Quantitative evaluation provided a better performance in terms of precision while maintaining similar results on sensitivity and Dice similarity measures compared with those of other approaches. Our tool is implemented as a publicly available SPM8/12 extension that can be used by both the medical and research communities. (orig.)

  5. Uncertainties in segmentation and their visualisation

    NARCIS (Netherlands)

    Lucieer, Arko

    2004-01-01

    This thesis focuses on uncertainties in remotely sensed image segmentation and their visualisation. The first part describes a visualisation tool, allowing interaction with the parameters of a fuzzy classification algorithm by visually adjusting fuzzy membership functions of classes in a 3D feature

  6. Benchmark for license plate character segmentation

    Science.gov (United States)

    Gonçalves, Gabriel Resende; da Silva, Sirlene Pio Gomes; Menotti, David; Shwartz, William Robson

    2016-09-01

    Automatic license plate recognition (ALPR) has been the focus of many researches in the past years. In general, ALPR is divided into the following problems: detection of on-track vehicles, license plate detection, segmentation of license plate characters, and optical character recognition (OCR). Even though commercial solutions are available for controlled acquisition conditions, e.g., the entrance of a parking lot, ALPR is still an open problem when dealing with data acquired from uncontrolled environments, such as roads and highways when relying only on imaging sensors. Due to the multiple orientations and scales of the license plates captured by the camera, a very challenging task of the ALPR is the license plate character segmentation (LPCS) step, because its effectiveness is required to be (near) optimal to achieve a high recognition rate by the OCR. To tackle the LPCS problem, this work proposes a benchmark composed of a dataset designed to focus specifically on the character segmentation step of the ALPR within an evaluation protocol. Furthermore, we propose the Jaccard-centroid coefficient, an evaluation measure more suitable than the Jaccard coefficient regarding the location of the bounding box within the ground-truth annotation. The dataset is composed of 2000 Brazilian license plates consisting of 14000 alphanumeric symbols and their corresponding bounding box annotations. We also present a straightforward approach to perform LPCS efficiently. Finally, we provide an experimental evaluation for the dataset based on five LPCS approaches and demonstrate the importance of character segmentation for achieving an accurate OCR.

  7. Segmenting the MBA Market: An Australian Strategy.

    Science.gov (United States)

    Everett, James E.; Armstrong, Robert W.

    1990-01-01

    A University of Western Australia market segmentation study for the masters program in business administration examined the relationship between Graduate Management Admission Test scores, work experience, faculty of undergraduate degree, gender, and academic success in the program. Implications of the results for establishing admission criteria…

  8. Informational segmentation in international capital markets

    OpenAIRE

    Wahl, Jack E.

    1988-01-01

    The economic influence of barriers to international information acquisition and, hence, of informational segmentation in international capital markets depends heavily upon the prevailing level of risk aversion. We find that these barriers are likely to have second order economic impact only. Furthermore, improving international informational integration is likely to Increase all asset prices when causing less heterogeneity of international subjective probability beliefs.

  9. Hierarchical pre-segmentation without prior knowledge

    NARCIS (Netherlands)

    Kuijper, A.; Florack, L.M.J.

    2001-01-01

    A new method to pre-segment images by means of a hierarchical description is proposed. This description is obtained from an investigation of the deep structure of a scale space image – the input image and the Gaussian filtered ones simultaneously. We concentrate on scale space critical points –

  10. Document flow segmentation for business applications

    Science.gov (United States)

    Daher, Hani; Belaïd, Abdel

    2013-12-01

    The aim of this paper is to propose a document flow supervised segmentation approach applied to real world heterogeneous documents. Our algorithm treats the flow of documents as couples of consecutive pages and studies the relationship that exists between them. At first, sets of features are extracted from the pages where we propose an approach to model the couple of pages into a single feature vector representation. This representation will be provided to a binary classifier which classifies the relationship as either segmentation or continuity. In case of segmentation, we consider that we have a complete document and the analysis of the flow continues by starting a new document. In case of continuity, the couple of pages are assimilated to the same document and the analysis continues on the flow. If there is an uncertainty on whether the relationship between the couple of pages should be classified as a continuity or segmentation, a rejection is decided and the pages analyzed until this point are considered as a "fragment". The first classification already provides good results approaching 90% on certain documents, which is high at this level of the system.

  11. A toolbox for multiple sclerosis lesion segmentation

    International Nuclear Information System (INIS)

    Roura, Eloy; Oliver, Arnau; Valverde, Sergi; Llado, Xavier; Cabezas, Mariano; Pareto, Deborah; Rovira, Alex; Vilanova, Joan C.; Ramio-Torrenta, Lluis

    2015-01-01

    Lesion segmentation plays an important role in the diagnosis and follow-up of multiple sclerosis (MS). This task is very time-consuming and subject to intra- and inter-rater variability. In this paper, we present a new tool for automated MS lesion segmentation using T1w and fluid-attenuated inversion recovery (FLAIR) images. Our approach is based on two main steps, initial brain tissue segmentation according to the gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) performed in T1w images, followed by a second step where the lesions are segmented as outliers to the normal apparent GM brain tissue on the FLAIR image. The tool has been validated using data from more than 100 MS patients acquired with different scanners and at different magnetic field strengths. Quantitative evaluation provided a better performance in terms of precision while maintaining similar results on sensitivity and Dice similarity measures compared with those of other approaches. Our tool is implemented as a publicly available SPM8/12 extension that can be used by both the medical and research communities. (orig.)

  12. Local Stereo Matching Using Adaptive Local Segmentation

    NARCIS (Netherlands)

    Damjanovic, S.; van der Heijden, Ferdinand; Spreeuwers, Lieuwe Jan

    We propose a new dense local stereo matching framework for gray-level images based on an adaptive local segmentation using a dynamic threshold. We define a new validity domain of the fronto-parallel assumption based on the local intensity variations in the 4-neighborhood of the matching pixel. The

  13. Prague texture segmentation data generator and benchmark

    Czech Academy of Sciences Publication Activity Database

    Mikeš, Stanislav; Haindl, Michal

    2006-01-01

    Roč. 2006, č. 64 (2006), s. 67-68 ISSN 0926-4981 R&D Projects: GA MŠk(CZ) 1M0572; GA AV ČR(CZ) 1ET400750407; GA AV ČR IAA2075302 Institutional research plan: CEZ:AV0Z10750506 Keywords : image segmentation * texture * benchmark * web Subject RIV: BD - Theory of Information

  14. Segmentation and Classification of Burn Color Images

    National Research Council Canada - National Science Library

    Acha, Begonya

    2001-01-01

    .... In the classification part, we take advantage of color information by clustering, with a vector quantization algorithm, the color centroids of small squares, taken from the burnt segmented part of the image, in the (V1, V2) plane into two possible groups, where V1 and V2 are the two chrominance components of the CIE Lab representation.

  15. Multiscale Vessel-guided Airway Tree Segmentation

    DEFF Research Database (Denmark)

    Lo, Pechin Chien Pau; Sporring, Jon; de Bruijne, Marleen

    2009-01-01

    This paper presents a method for airway tree segmentation that uses a combination of a trained airway appearance model, vessel and airway orientation information, and region growing. The method uses a voxel classification based appearance model, which involves the use of a classifier that is trai...

  16. Ambulatory ST segment monitoring after myocardial infarction

    DEFF Research Database (Denmark)

    Mickley, H

    1994-01-01

    as important reasons for the inconsistent findings. The precise role of ambulatory ST segment monitoring in clinical practice has yet to be established. Direct comparisons with exercise stress testing may not be appropriate for two reasons. Firstly, the main advantage of ambulatory monitoring may...

  17. Improving cerebellar segmentation with statistical fusion

    Science.gov (United States)

    Plassard, Andrew J.; Yang, Zhen; Prince, Jerry L.; Claassen, Daniel O.; Landman, Bennett A.

    2016-03-01

    The cerebellum is a somatotopically organized central component of the central nervous system well known to be involved with motor coordination and increasingly recognized roles in cognition and planning. Recent work in multiatlas labeling has created methods that offer the potential for fully automated 3-D parcellation of the cerebellar lobules and vermis (which are organizationally equivalent to cortical gray matter areas). This work explores the trade offs of using different statistical fusion techniques and post hoc optimizations in two datasets with distinct imaging protocols. We offer a novel fusion technique by extending the ideas of the Selective and Iterative Method for Performance Level Estimation (SIMPLE) to a patch-based performance model. We demonstrate the effectiveness of our algorithm, Non- Local SIMPLE, for segmentation of a mixed population of healthy subjects and patients with severe cerebellar anatomy. Under the first imaging protocol, we show that Non-Local SIMPLE outperforms previous gold-standard segmentation techniques. In the second imaging protocol, we show that Non-Local SIMPLE outperforms previous gold standard techniques but is outperformed by a non-locally weighted vote with the deeper population of atlases available. This work advances the state of the art in open source cerebellar segmentation algorithms and offers the opportunity for routinely including cerebellar segmentation in magnetic resonance imaging studies that acquire whole brain T1-weighted volumes with approximately 1 mm isotropic resolution.

  18. Encapsulation of nodal segments of lobelia chinensis

    Directory of Open Access Journals (Sweden)

    Weng Hing Thong

    2015-04-01

    Full Text Available Lobelia chinensis served as an important herb in traditional chinese medicine. It is rare in the field and infected by some pathogens. Therefore, encapsulation of axillary buds has been developed for in vitro propagation of L. chinensis. Nodal explants of L. chinensis were used as inclusion materials for encapsulation. Various combinations of calcium chloride and sodium alginate were tested. Encapsulation beads produced by mixing 50 mM calcium chloride and 3.5% sodium alginate supported the optimal in vitro conversion potential. The number of multiple shoots formed by encapsulated nodal segments was not significantly different from the average of shoots produced by non-encapsulated nodal segments. The encapsulated nodal segments regenerated in vitro on different medium. The optimal germination and regeneration medium was Murashige-Skoog medium. Plantlets regenerated from the encapsulated nodal segments were hardened, acclimatized and established well in the field, showing similar morphology with parent plants. This encapsulation technology would serve as an alternative in vitro regeneration system for L. chinensis.

  19. RGB-D Segmentation of Poultry Entrails

    DEFF Research Database (Denmark)

    Philipsen, Mark Philip; Jørgensen, Anders; Guerrero, Sergio Escalera

    2016-01-01

    and passed to a Random Forest classifier, which classifies the supervoxels as either belonging to heart, lung, liver or misc. The dataset consists of 150 individual entrails, with 30 of these being reserved for evaluation. Segmentation performance is evaluated on a voxel-by-voxel basis, achieving an average...

  20. Superresolution improves MRI cortical segmentation with FACE

    DEFF Research Database (Denmark)

    Eskildsen, Simon Fristed; Manjón, José V.; Coupé, Pierrick

    the cerebral cortex have been developed during the last decade (Dale 1999, Kim 2005, Eskildsen 2006). In many studies, the resolution of the morphological image acquisition sequence is chosen to be relatively low (~1mm3) due to time and equipment constraints. To improve segmentation accuracy, such low...

  1. The Activity Structure of Lesson Segments.

    Science.gov (United States)

    Burns, Robert B.; Anderson, Lorin W.

    1987-01-01

    Approaches classroom instruction and teacher effectiveness by conceptualizing the physical milieu shaping teacher-student interactions. Lessons are viewed as a series of segments with three components (purpose, activity format, and assignment) that help characterize the instructional environment. Scripts are suggested to help regulate activity…

  2. Segmentation and packaging reactor vessels internals

    International Nuclear Information System (INIS)

    Boucau, Joseph

    2014-01-01

    Document available in abstract form only, full text follows: With more than 25 years of experience in the development of reactor vessel internals and reactor vessel segmentation and packaging technology, Westinghouse has accumulated significant know-how in the reactor dismantling market. The primary challenges of a segmentation and packaging project are to separate the highly activated materials from the less-activated materials and package them into appropriate containers for disposal. Since disposal cost is a key factor, it is important to plan and optimize waste segmentation and packaging. The choice of the optimum cutting technology is also important for a successful project implementation and depends on some specific constraints. Detailed 3-D modeling is the basis for tooling design and provides invaluable support in determining the optimum strategy for component cutting and disposal in waste containers, taking account of the radiological and packaging constraints. The usual method is to start at the end of the process, by evaluating handling of the containers, the waste disposal requirements, what type and size of containers are available for the different disposal options, and working backwards to select a cutting method and finally the cut geometry required. The 3-D models can include intelligent data such as weight, center of gravity, curie content, etc, for each segmented piece, which is very useful when comparing various cutting, handling and packaging options. The detailed 3-D analyses and thorough characterization assessment can draw the attention to material potentially subject to clearance, either directly or after certain period of decay, to allow recycling and further disposal cost reduction. Westinghouse has developed a variety of special cutting and handling tools, support fixtures, service bridges, water filtration systems, video-monitoring systems and customized rigging, all of which are required for a successful reactor vessel internals

  3. Construction time of PWRs

    International Nuclear Information System (INIS)

    Moreira, João M.L.; Gallinaro, Bruno; Carajilescov, Pedro

    2013-01-01

    The construction time of PWRs is studied considering published data about nuclear power plants in the world. For the 268 PWRs in operation in 2010, the mode of the construction time distribution is around 5–6 years, and 80% of the plants were built in less than 120 months. To circumvent the problem of comparing plants with different size we normalized the construction time to plants with 1 GW. We restricted the analysis to 201 PWRs which suffered less from external factors that were beyond the control of the management from 1965 to 2010. The results showed that the normalized construction time did not increase over the years and nor with the plants’ gross power level. The learning rate of the industry regarding normalized construction times showed a reduction with 95% confidence level of about 0.56±0.07 months for each 10 GW of installed capacity. Over the years the normalized construction time decreased and became more predictable. The data showed that countries with more centralized regulatory, construction and operation environments were able to build PWRs in shorter times. Countries less experienced with the nuclear technology built PWRs in longer times. - Highlights: ► The construction time of PWRs is analyzed based on historical data. ► Different factors affecting construction time are considered in the analyses. ► The normalized construction time of PWRs decreased with time and gross power level. ► Countries with more centralized institutions built PWRs more quickly

  4. Segmentation of ribs in digital chest radiographs

    Science.gov (United States)

    Cong, Lin; Guo, Wei; Li, Qiang

    2016-03-01

    Ribs and clavicles in posterior-anterior (PA) digital chest radiographs often overlap with lung abnormalities such as nodules, and cause missing of these abnormalities, it is therefore necessary to remove or reduce the ribs in chest radiographs. The purpose of this study was to develop a fully automated algorithm to segment ribs within lung area in digital radiography (DR) for removal of the ribs. The rib segmentation algorithm consists of three steps. Firstly, a radiograph was pre-processed for contrast adjustment and noise removal; second, generalized Hough transform was employed to localize the lower boundary of the ribs. In the third step, a novel bilateral dynamic programming algorithm was used to accurately segment the upper and lower boundaries of ribs simultaneously. The width of the ribs and the smoothness of the rib boundaries were incorporated in the cost function of the bilateral dynamic programming for obtaining consistent results for the upper and lower boundaries. Our database consisted of 93 DR images, including, respectively, 23 and 70 images acquired with a DR system from Shanghai United-Imaging Healthcare Co. and from GE Healthcare Co. The rib localization algorithm achieved a sensitivity of 98.2% with 0.1 false positives per image. The accuracy of the detected ribs was further evaluated subjectively in 3 levels: "1", good; "2", acceptable; "3", poor. The percentages of good, acceptable, and poor segmentation results were 91.1%, 7.2%, and 1.7%, respectively. Our algorithm can obtain good segmentation results for ribs in chest radiography and would be useful for rib reduction in our future study.

  5. Global multi-scale segmentation of continental and coastal waters from the watersheds to the continental margins

    NARCIS (Netherlands)

    Laruelle, G.G.; Dürr, H.H.; Lauerwald, R.; Hartmann, J.; Slomp, C.P.; Goossens, N.; Regnier, P.A.G.

    2013-01-01

    Past characterizations of the land–ocean continuum were constructed either from a continental perspective through an analysis of watershed river basin properties (COSCATs: COastal Segmentation and related CATchments) or from an oceanic perspective, through a regionalization of the proximal and

  6. Constructing Student Problems in Phylogenetic Tree Construction.

    Science.gov (United States)

    Brewer, Steven D.

    Evolution is often equated with natural selection and is taught from a primarily functional perspective while comparative and historical approaches, which are critical for developing an appreciation of the power of evolutionary theory, are often neglected. This report describes a study of expert problem-solving in phylogenetic tree construction.…

  7. Reconstruction of segmented human voxel phantoms for skin dosimetry

    International Nuclear Information System (INIS)

    Antunes, Paula C.G.; Siqueira, Paulo de Tarso D.; Yoriyaz, Helio; Fonseca, Gabriel P.; Reis, Gabriela; Furnari, Laura

    2009-01-01

    High-resolution medical images along with methods that simulate the interaction of radiation with matter, as the Monte Carlo radiation transport codes, have been widely used in medical physics procedures. These images provide the construction of realistic anatomical models, which after being coupled to these codes, may drive to better assessments of dose distributions on the patient. These anatomical models constructed from medical images are known as voxel phantoms (voxel - volume element of an image). Present day regular images are unsuitable to correctly perform skin dose distribution evaluations. This inability is due to improper skin discrimination in most of the current medical images, once its thickness stands below the resolution of the pixels that form the image. This paper proposes the voxel phantom reconstruction by subdividing and segmenting the elements that form the phantom. It is done in order to better discriminate the skin by assigning it more adequate thickness and actual location, allowing a better dosimetric evaluation of the skin. This task is an important issue in many radiotherapy procedures. Particular interest lays in Total Skin Irradiation (TSI) with electron beams, where skin dose evaluation stands as the treatment key point of the whole body irradiation. This radiotherapy procedure is under implementation at the Hospital das Clinicas da Universidade de Sao Paulo (HC-USP). (author)

  8. Generalized pixel profiling and comparative segmentation with application to arteriovenous malformation segmentation.

    Science.gov (United States)

    Babin, D; Pižurica, A; Bellens, R; De Bock, J; Shang, Y; Goossens, B; Vansteenkiste, E; Philips, W

    2012-07-01

    Extraction of structural and geometric information from 3-D images of blood vessels is a well known and widely addressed segmentation problem. The segmentation of cerebral blood vessels is of great importance in diagnostic and clinical applications, with a special application in diagnostics and surgery on arteriovenous malformations (AVM). However, the techniques addressing the problem of the AVM inner structure segmentation are rare. In this work we present a novel method of pixel profiling with the application to segmentation of the 3-D angiography AVM images. Our algorithm stands out in situations with low resolution images and high variability of pixel intensity. Another advantage of our method is that the parameters are set automatically, which yields little manual user intervention. The results on phantoms and real data demonstrate its effectiveness and potentials for fine delineation of AVM structure. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. A novel line segment detection algorithm based on graph search

    Science.gov (United States)

    Zhao, Hong-dan; Liu, Guo-ying; Song, Xu

    2018-02-01

    To overcome the problem of extracting line segment from an image, a method of line segment detection was proposed based on the graph search algorithm. After obtaining the edge detection result of the image, the candidate straight line segments are obtained in four directions. For the candidate straight line segments, their adjacency relationships are depicted by a graph model, based on which the depth-first search algorithm is employed to determine how many adjacent line segments need to be merged. Finally we use the least squares method to fit the detected straight lines. The comparative experimental results verify that the proposed algorithm has achieved better results than the line segment detector (LSD).

  10. Professional entrepreneurial identity construction

    DEFF Research Database (Denmark)

    Ramsgaard, Michael Breum

    The present study investigates the construction of a professional identity as an entrepreneur in a sample of people with educational background in nutrition and health. The study examines the connection between professional identity construction and entrepreneurial business emergence using...... ‘entrepreneurial preparedness’ as parameter. This research seeks to address the following questions: What significant components or characteristics do entrepreneurs rely on in the early processes of constructing an entrepreneurial identity....

  11. Imperfect construction of microclusters

    Science.gov (United States)

    Schneider, E.; Zhou, K.; Gilbert, G.; Weinstein, Y. S.

    2014-01-01

    Microclusters are the basic building blocks used to construct cluster states capable of supporting fault-tolerant quantum computation. In this paper, we explore the consequences of errors on microcluster construction using two error models. To quantify the effect of the errors we calculate the fidelity of the constructed microclusters and the fidelity with which two such microclusters can be fused together. Such simulations are vital for gauging the capability of an experimental system to achieve fault tolerance.

  12. VE of construction industry

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1987-10-15

    This book gives descriptions of basic of VE of construction industry including doing away with mannerism, necessity of cost reduction, management method of cost reduction, thinking of idea, target of VE, starting VE activity, technical method of VE of construction industry such as thinking of idea with brainstorming, function trade method, new brainstorming, MM method, morphology analysis and lateral thinking, cases of VE of construction industry.

  13. VE of construction industry

    International Nuclear Information System (INIS)

    1987-10-01

    This book gives descriptions of basic of VE of construction industry including doing away with mannerism, necessity of cost reduction, management method of cost reduction, thinking of idea, target of VE, starting VE activity, technical method of VE of construction industry such as thinking of idea with brainstorming, function trade method, new brainstorming, MM method, morphology analysis and lateral thinking, cases of VE of construction industry.

  14. HITACHI construction CAE system

    International Nuclear Information System (INIS)

    Yoshida, M.

    1994-01-01

    Construction and maintenance of nuclear power plants have important problems such as shortening the construction period and reducing the construction cost. Recently, the problem of insufficient construction labor has arisen, and as drastic strategic development has become a necessary counter-measure. The following four principles are included in the measures to be taken for efficient execution of the construction work within the short construction period: (1) reduction of on-site work and expansion of module block making, (2)improvement of the accuracy of the on-site work process, adjustment and expansion of the work in parallel with the construction process, (3)improvement of efficiency of the on-site work and mechanization and automation of the work, (4)improvement of the accuracy of the management of the construction. A three dimensional simulation system plant construction plan CAE, comprising five modules has been developed. A project management system was also developed to improve the accuracy and efficiency of management work in the field

  15. Segmentation-Based And Segmentation-Free Methods for Spotting Handwritten Arabic Words

    OpenAIRE

    Ball , Gregory R.; Srihari , Sargur N.; Srinivasan , Harish

    2006-01-01

    http://www.suvisoft.com; Given a set of handwritten documents, a common goal is to search for a relevant subset. Attempting to find a query word or image in such a set of documents is called word spotting. Spotting handwritten words in documents written in the Latin alphabet, and more recently in Arabic, has received considerable attention. One issue is generating candidate word regions on a page. Attempting to definitely segment the document into such regions (automatic segmentation) can mee...

  16. A combined segmenting and non-segmenting approach to signal quality estimation for ambulatory photoplethysmography

    International Nuclear Information System (INIS)

    Wander, J D; Morris, D

    2014-01-01

    Continuous cardiac monitoring of healthy and unhealthy patients can help us understand the progression of heart disease and enable early treatment. Optical pulse sensing is an excellent candidate for continuous mobile monitoring of cardiovascular health indicators, but optical pulse signals are susceptible to corruption from a number of noise sources, including motion artifact. Therefore, before higher-level health indicators can be reliably computed, corrupted data must be separated from valid data. This is an especially difficult task in the presence of artifact caused by ambulation (e.g. walking or jogging), which shares significant spectral energy with the true pulsatile signal. In this manuscript, we present a machine-learning-based system for automated estimation of signal quality of optical pulse signals that performs well in the presence of periodic artifact. We hypothesized that signal processing methods that identified individual heart beats (segmenting approaches) would be more error-prone than methods that did not (non-segmenting approaches) when applied to data contaminated by periodic artifact. We further hypothesized that a fusion of segmenting and non-segmenting approaches would outperform either approach alone. Therefore, we developed a novel non-segmenting approach to signal quality estimation that we then utilized in combination with a traditional segmenting approach. Using this system we were able to robustly detect differences in signal quality as labeled by expert human raters (Pearson’s r = 0.9263). We then validated our original hypotheses by demonstrating that our non-segmenting approach outperformed the segmenting approach in the presence of contaminated signal, and that the combined system outperformed either individually. Lastly, as an example, we demonstrated the utility of our signal quality estimation system in evaluating the trustworthiness of heart rate measurements derived from optical pulse signals. (paper)

  17. Compatibility of Segments of Thermoelectric Generators

    Science.gov (United States)

    Snyder, G. Jeffrey; Ursell, Tristan

    2009-01-01

    A method of calculating (usually for the purpose of maximizing) the power-conversion efficiency of a segmented thermoelectric generator is based on equations derived from the fundamental equations of thermoelectricity. Because it is directly traceable to first principles, the method provides physical explanations in addition to predictions of phenomena involved in segmentation. In comparison with the finite-element method used heretofore to predict (without being able to explain) the behavior of a segmented thermoelectric generator, this method is much simpler to implement in practice: in particular, the efficiency of a segmented thermoelectric generator can be estimated by evaluating equations using only hand-held calculator with this method. In addition, the method provides for determination of cascading ratios. The concept of cascading is illustrated in the figure and the definition of the cascading ratio is defined in the figure caption. An important aspect of the method is its approach to the issue of compatibility among segments, in combination with introduction of the concept of compatibility within a segment. Prior approaches involved the use of only averaged material properties. Two materials in direct contact could be examined for compatibility with each other, but there was no general framework for analysis of compatibility. The present method establishes such a framework. The mathematical derivation of the method begins with the definition of reduced efficiency of a thermoelectric generator as the ratio between (1) its thermal-to-electric power-conversion efficiency and (2) its Carnot efficiency (the maximum efficiency theoretically attainable, given its hot- and cold-side temperatures). The derivation involves calculation of the reduced efficiency of a model thermoelectric generator for which the hot-side temperature is only infinitesimally greater than the cold-side temperature. The derivation includes consideration of the ratio (u) between the

  18. Skip segment Hirschsprung's disease: a systematic review.

    LENUS (Irish Health Repository)

    O'Donnell, Anne-Marie

    2012-02-01

    PURPOSE: Hirschsprung\\'s disease is characterised by the congenital absence of ganglion cells beginning in the distal rectum and extending proximally for varying distances. \\'Zonal aganglionosis\\' is a phenomenon involving a zone of aganglionosis occurring within normally innervated intestine. \\'Skip segment\\' Hirschsprung\\'s disease (SSHD) involves a \\'skip area\\' of normally ganglionated intestine, surrounded proximally and distally by aganglionosis. While Hirschsprung\\'s disease is believed to be the result of incomplete craniocaudal migration of neural crest-derived cells, the occurrence of SSHD has no clear embryological explanation. The aim of this study was to perform a systematic review of SSHD, reported in the literature between 1954 and 2009, in order to determine the clinical characteristics of this rare entity and its significance. METHODS: The first reported case of SSHD was published in 1954. A systematic review of SSHD cases in the literature, from 1954 to 2009, was carried out using the electronic database \\'Pubmed\\'. Detailed information was recorded regarding the age, gender, presenting symptoms and location of the skip segment in each patient. RESULTS: 24 cases of SSHD have been reported in the literature to date. 18\\/24 (75%) of these cases were males and 6\\/24 (25%) were females. Of these, 22\\/24 (92%) were cases of total colonic aganglionosis (TCA), and 2\\/24 (8%) were rectosigmoid Hirschsprung\\'s disease. Of the 22 TCA cases, 9 (41%) had a skip segment in the transverse colon, 6 (27%) in the ascending colon, 2 (9%) in the caecum and 5 (23%) had multiple skip segments. In both rectosigmoid Hirschsprung\\'s disease cases, the skip segment was in the sigmoid colon. Overall, the length of the skip segment was variable, with the entire transverse colon ganglionated in some cases. CONCLUSION: SSHD occurs predominantly in patients with TCA. The existence of a skip area of normally innervated colon in TCA may influence surgical

  19. Noise destroys feedback enhanced figure-ground segmentation but not feedforward figure-ground segmentation

    Science.gov (United States)

    Romeo, August; Arall, Marina; Supèr, Hans

    2012-01-01

    Figure-ground (FG) segmentation is the separation of visual information into background and foreground objects. In the visual cortex, FG responses are observed in the late stimulus response period, when neurons fire in tonic mode, and are accompanied by a switch in cortical state. When such a switch does not occur, FG segmentation fails. Currently, it is not known what happens in the brain on such occasions. A biologically plausible feedforward spiking neuron model was previously devised that performed FG segmentation successfully. After incorporating feedback the FG signal was enhanced, which was accompanied by a change in spiking regime. In a feedforward model neurons respond in a bursting mode whereas in the feedback model neurons fired in tonic mode. It is known that bursts can overcome noise, while tonic firing appears to be much more sensitive to noise. In the present study, we try to elucidate how the presence of noise can impair FG segmentation, and to what extent the feedforward and feedback pathways can overcome noise. We show that noise specifically destroys the feedback enhanced FG segmentation and leaves the feedforward FG segmentation largely intact. Our results predict that noise produces failure in FG perception. PMID:22934028

  20. Construction of six Oryza sativa x O. rufipogon Chromosome Segment Substitution Line (CSSL) Libraries

    Science.gov (United States)

    Transgressive variation has been observed in rice (Oryza sativa) as an increase in grain yield and attributed to the ancestral parent, O. rufipogon, in mapping populations developed from several adapted rice varieties crossed with a single O. rufipogon accession. To explore this phenomenon of transg...

  1. Liaison Acquisition, Word Segmentation and Construction in French: A Usage-Based Account

    Science.gov (United States)

    Chevrot, Jean-Pierre; Dugua, Celine; Fayol, Michel

    2009-01-01

    In the linguistics field, liaison in French is interpreted as an indicator of interactions between the various levels of language organization. The current study examines the same issue while adopting a developmental perspective. Five experiments involving children aged two to six years provide evidence for a developmental scenario which…

  2. Beyond Retinal Layers: A Deep Voting Model for Automated Geographic Atrophy Segmentation in SD-OCT Images.

    Science.gov (United States)

    Ji, Zexuan; Chen, Qiang; Niu, Sijie; Leng, Theodore; Rubin, Daniel L

    2018-01-01

    To automatically and accurately segment geographic atrophy (GA) in spectral-domain optical coherence tomography (SD-OCT) images by constructing a voting system with deep neural networks without the use of retinal layer segmentation. An automatic GA segmentation method for SD-OCT images based on the deep network was constructed. The structure of the deep network was composed of five layers, including one input layer, three hidden layers, and one output layer. During the training phase, the labeled A-scans with 1024 features were directly fed into the network as the input layer to obtain the deep representations. Then a soft-max classifier was trained to determine the label of each individual pixel. Finally, a voting decision strategy was used to refine the segmentation results among 10 trained models. Two image data sets with GA were used to evaluate the model. For the first dataset, our algorithm obtained a mean overlap ratio (OR) 86.94% ± 8.75%, absolute area difference (AAD) 11.49% ± 11.50%, and correlation coefficients (CC) 0.9857; for the second dataset, the mean OR, AAD, and CC of the proposed method were 81.66% ± 10.93%, 8.30% ± 9.09%, and 0.9952, respectively. The proposed algorithm was capable of improving over 5% and 10% segmentation accuracy, respectively, when compared with several state-of-the-art algorithms on two data sets. Without retinal layer segmentation, the proposed algorithm could produce higher segmentation accuracy and was more stable when compared with state-of-the-art methods that relied on retinal layer segmentation results. Our model may provide reliable GA segmentations from SD-OCT images and be useful in the clinical diagnosis of advanced nonexudative AMD. Based on the deep neural networks, this study presents an accurate GA segmentation method for SD-OCT images without using any retinal layer segmentation results, and may contribute to improved understanding of advanced nonexudative AMD.

  3. Estimation of network path segment delays

    Science.gov (United States)

    Nichols, Kathleen Marie

    2018-05-01

    A method for estimation of a network path segment delay includes determining a scaled time stamp for each packet of a plurality of packets by scaling a time stamp for each respective packet to minimize a difference of at least one of a frequency and a frequency drift between a transport protocol clock of a host and a monitoring point. The time stamp for each packet is provided by the transport protocol clock of the host. A corrected time stamp for each packet is determined by removing from the scaled time stamp for each respective packet, a temporal offset between the transport protocol clock and the monitoring clock by minimizing a temporal delay variation of the plurality of packets traversing a segment between the host and the monitoring point.

  4. Retinal Image Preprocessing: Background and Noise Segmentation

    Directory of Open Access Journals (Sweden)

    Usman Akram

    2012-09-01

    Full Text Available Retinal images are used for the automated screening and diagnosis of diabetic retinopathy. The retinal image quality must be improved for the detection of features and abnormalities and for this purpose preprocessing of retinal images is vital. In this paper, we present a novel automated approach for preprocessing of colored retinal images. The proposed technique improves the quality of input retinal image by separating the background and noisy area from the overall image. It contains coarse segmentation and fine segmentation. Standard retinal images databases Diaretdb0, Diaretdb1, DRIVE and STARE are used to test the validation of our preprocessing technique. The experimental results show the validity of proposed preprocessing technique.

  5. Pyramidal approach to license plate segmentation

    Science.gov (United States)

    Postolache, Alexandru; Trecat, Jacques C.

    1996-07-01

    Car identification is a goal in traffic control, transport planning, travel time measurement, managing parking lot traffic and so on. Most car identification algorithms contain a standalone plate segmentation process followed by a plate contents reading. A pyramidal algorithm for license plate segmentation, looking for textured regions, has been developed on a PC based system running Unix. It can be used directly in applications not requiring real time. When input images are relatively small, real-time performance is in fact accomplished by the algorithm. When using large images, porting the algorithm to special digital signal processors can easily lead to preserving real-time performance. Experimental results, for stationary and moving cars in outdoor scenes, showed high accuracy and high scores in detecting the plate. The algorithm also deals with cases where many character strings are present in the image, and not only the one corresponding to the plate. This is done by the means of a constrained texture regions classification.

  6. Segmentation and Location Computation of Bin Objects

    Directory of Open Access Journals (Sweden)

    C.R. Hema

    2008-11-01

    Full Text Available In this paper we present a stereo vision based system for segmentation and location computation of partially occluded objects in bin picking environments. Algorithms to segment partially occluded objects and to find the object location [midpoint,x, y and z coordinates] with respect to the bin area are proposed. The z co ordinate is computed using stereo images and neural networks. The proposed algorithms is tested using two neural network architectures namely the Radial Basis Function nets and Simple Feedforward nets. The training results fo feedforward nets are found to be more suitable for the current application.The proposed stereo vision system is interfaced with an Adept SCARA Robot to perform bin picking operations. The vision system is found to be effective for partially occluded objects, in the absence of albedo effects. The results are validated through real time bin picking experiments on the Adept Robot.

  7. Stability of latent class segments over time

    DEFF Research Database (Denmark)

    Mueller, Simone

    2011-01-01

    Dynamic stability, as the degree to which identified segments at a given time remain unchanged over time in terms of number, size and profile, is a desirable segment property which has received limited attention so far. This study addresses the question to what degree latent classes identified from...... logit model suggests significant changes in the price sensitivity and the utility from environmental claims between both experimental waves. A pooled scale adjusted latent class model is estimated jointly over both waves and the relative size of latent classes is compared across waves, resulting...... in significant differences in the size of two out of seven classes. These differences can largely be accounted for by the changes on the aggregated level. The relative size of latent classes is correlated at 0.52, suggesting a fair robustness. An ex-post characterisation of latent classes by behavioural...

  8. Wall Construction; Carpentry: 901892.

    Science.gov (United States)

    Dade County Public Schools, Miami, FL.

    The curriculum guide outlines a course designed to provide instruction in floor and wall layout, and in the diverse methods and construction of walls. Upon completion of this course the students should have acquired a knowledge of construction plans and structural foundations in addition to a basic knowledge of mathematics. The course consists of…

  9. Safety in construction?

    NARCIS (Netherlands)

    Swuste, P.H.J.J.

    2013-01-01

    The available literature on Construction Safety is not very optimistic about the chances of evidence-based safety in the construction industry exerting a positive influence. Many articles indicate that the structures and processes that are designed to ensure safety in the industry are poor. Safety

  10. INDOT Construction Inspection Priorities

    Science.gov (United States)

    2012-05-01

    In the last decade, the Indiana Department of Transportation (INDOT) has experienced an increase in their construction projects (e.g., INDOTs : construction spending was $789 million in 2006 and increased to $1,081.4 million in 2010); while the le...

  11. Employment and winter construction

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place; Larsen, Jacob Norvig

    2011-01-01

    Reduced seasonal building activity in the construction sector is often assumed to be related to hard winter conditions for building activities and poor working conditions for construction workers, resulting in higher costs and poor quality of building products, particularly in the northern hemisp...... of contracts for workers is more likely to explain differences in seasonal activity than climatic or technological factors....

  12. Human Resource Construction

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Centering on strategic objective of reform and development,CIAE formulated its objectives in human resource construction for the 13th Five-year Plan period,and achieved new apparent progress in human resource construction in 2015.1 Implementation of"LONGMA Project"

  13. Governmentalities of Construction

    DEFF Research Database (Denmark)

    Gottlieb, Stefan; Jensen, Jens Stissing

    2016-01-01

    In this paper, we apply Foucault’s concept of governmentality in a dual analysis of the formation and transformation of the construction sector and the construction worker. The governmentality concept is well-suited for such an analysis as it directs attention to the ways in which control is the ...

  14. Nuclear reactor constructions

    International Nuclear Information System (INIS)

    Baddley, A.H.

    1981-01-01

    A method of constructing a radiation shielding plug for use in the roof of the coolant containment vault of liquid metal cooled fast breeder reactors is described. The construction allows relative movement of that part of service cables and pipes which are carried by the fixed roof and that part which is carried by the rotatable plug. (U.K.)

  15. Constructional and Conceptual Composition

    Science.gov (United States)

    Dodge, Ellen Kirsten

    2010-01-01

    Goldberg's (1995) recognition that, in addition to various word-level constructions, sentences also instantiate meaningful argument structure constructions enables a non-polysemy-based analysis of various verb 'alternations' (Levin 1993). In such an analysis, meaning variations associated with the use of the same verb in different argument…

  16. Personal Usability Constructs

    DEFF Research Database (Denmark)

    Hertzum, Morten; Clemmensen, Torkil; Hornbæk, Kasper

    2011-01-01

    Whereas the concept of usability is predominantly defined analytically, people relate to systems through personal usability constructs. Based on 48 repertory-grid interviews, this study investigates how such personal constructs are affected by two factors crucial to the international development...

  17. Industrialization for sustainable construction?

    NARCIS (Netherlands)

    Egmond - de Wilde De Ligny, van E.L.C.; Barrett, P; Amaratunga, D.; Haigh, R; Keraminiyage, K.; Pathirage, C

    2010-01-01

    Sustainable construction (SuCo), which genesis dates in the early 1990’s, advocates the creation and operation of a quality and healthy built environment based on resource efficiency, life cycle economics and ecological principles. (Kibert, 2003). Currently the Construction Industry does not meet

  18. Cerebrovascular plaque segmentation using object class uncertainty snake in MR images

    Science.gov (United States)

    Das, Bipul; Saha, Punam K.; Wolf, Ronald; Song, Hee Kwon; Wright, Alexander C.; Wehrli, Felix W.

    2005-04-01

    Atherosclerotic cerebrovascular disease leads to formation of lipid-laden plaques that can form emboli when ruptured causing blockage to cerebral vessels. The clinical manifestation of this event sequence is stroke; a leading cause of disability and death. In vivo MR imaging provides detailed image of vascular architecture for the carotid artery making it suitable for analysis of morphological features. Assessing the status of carotid arteries that supplies blood to the brain is of primary interest to such investigations. Reproducible quantification of carotid artery dimensions in MR images is essential for plaque analysis. Manual segmentation being the only method presently makes it time consuming and sensitive to inter and intra observer variability. This paper presents a deformable model for lumen and vessel wall segmentation of carotid artery from MR images. The major challenges of carotid artery segmentation are (a) low signal-to-noise ratio, (b) background intensity inhomogeneity and (c) indistinct inner and/or outer vessel wall. We propose a new, effective object-class uncertainty based deformable model with additional features tailored toward this specific application. Object-class uncertainty optimally utilizes MR intensity characteristics of various anatomic entities that enable the snake to avert leakage through fuzzy boundaries. To strengthen the deformable model for this application, some other properties are attributed to it in the form of (1) fully arc-based deformation using a Gaussian model to maximally exploit vessel wall smoothness, (2) construction of a forbidden region for outer-wall segmentation to reduce interferences by prominent lumen features and (3) arc-based landmark for efficient user interaction. The algorithm has been tested upon T1- and PD- weighted images. Measures of lumen area and vessel wall area are computed from segmented data of 10 patient MR images and their accuracy and reproducibility are examined. These results correspond

  19. Ancestral patterning of tergite formation in a centipede suggests derived mode of trunk segmentation in trilobites.

    Directory of Open Access Journals (Sweden)

    Javier Ortega-Hernández

    Full Text Available Trilobites have a rich and abundant fossil record, but little is known about the intrinsic mechanisms that orchestrate their body organization. To date, there is disagreement regarding the correspondence, or lack thereof, of the segmental units that constitute the trilobite trunk and their associated exoskeletal elements. The phylogenetic position of trilobites within total-group Euarthropoda, however, allows inferences about the underlying organization in these extinct taxa to be made, as some of the fundamental genetic processes for constructing the trunk segments are remarkably conserved among living arthropods. One example is the expression of the segment polarity gene engrailed, which at embryonic and early postembryonic stages is expressed in extant panarthropods (i.e. tardigrades, onychophorans, euarthropods as transverse stripes that define the posteriormost region of each trunk segment. Due to its conservative morphology and allegedly primitive trunk tagmosis, we have utilized the centipede Strigamia maritima to study the correspondence between the expression of engrailed during late embryonic to postembryonic stages, and the development of the dorsal exoskeletal plates (i.e. tergites. The results corroborate the close correlation between the formation of the tergite borders and the dorsal expression of engrailed, and suggest that this association represents a symplesiomorphy within Euarthropoda. This correspondence between the genetic and phenetic levels enables making accurate inferences about the dorsoventral expression domains of engrailed in the trunk of exceptionally preserved trilobites and their close relatives, and is suggestive of the widespread occurrence of a distinct type of genetic segmental mismatch in these extinct arthropods. The metameric organization of the digestive tract in trilobites provides further support to this new interpretation. The wider evolutionary implications of these findings suggest the presence of a

  20. Tracking fuzzy borders using geodesic curves with application to liver segmentation on planning CT

    International Nuclear Information System (INIS)

    Yuan, Yading; Chao, Ming; Sheu, Ren-Dih; Rosenzweig, Kenneth; Lo, Yeh-Chi

    2015-01-01

    Purpose: This work aims to develop a robust and efficient method to track the fuzzy borders between liver and the abutted organs where automatic liver segmentation usually suffers, and to investigate its applications in automatic liver segmentation on noncontrast-enhanced planning computed tomography (CT) images. Methods: In order to track the fuzzy liver–chestwall and liver–heart borders where oversegmentation is often found, a starting point and an ending point were first identified on the coronal view images; the fuzzy border was then determined as a geodesic curve constructed by minimizing the gradient-weighted path length between these two points near the fuzzy border. The minimization of path length was numerically solved by fast-marching method. The resultant fuzzy borders were incorporated into the authors’ automatic segmentation scheme, in which the liver was initially estimated by a patient-specific adaptive thresholding and then refined by a geodesic active contour model. By using planning CT images of 15 liver patients treated with stereotactic body radiation therapy, the liver contours extracted by the proposed computerized scheme were compared with those manually delineated by a radiation oncologist. Results: The proposed automatic liver segmentation method yielded an average Dice similarity coefficient of 0.930 ± 0.015, whereas it was 0.912 ± 0.020 if the fuzzy border tracking was not used. The application of fuzzy border tracking was found to significantly improve the segmentation performance. The mean liver volume obtained by the proposed method was 1727 cm 3 , whereas it was 1719 cm 3 for manual-outlined volumes. The computer-generated liver volumes achieved excellent agreement with manual-outlined volumes with correlation coefficient of 0.98. Conclusions: The proposed method was shown to provide accurate segmentation for liver in the planning CT images where contrast agent is not applied. The authors’ results also clearly demonstrated