WorldWideScience

Sample records for hybrid segmentation techniques

  1. Brain tumor segmentation based on a hybrid clustering technique

    Directory of Open Access Journals (Sweden)

    Eman Abdel-Maksoud

    2015-03-01

    This paper presents an efficient image segmentation approach using K-means clustering technique integrated with Fuzzy C-means algorithm. It is followed by thresholding and level set segmentation stages to provide an accurate brain tumor detection. The proposed technique can get benefits of the K-means clustering for image segmentation in the aspects of minimal computation time. In addition, it can get advantages of the Fuzzy C-means in the aspects of accuracy. The performance of the proposed image segmentation approach was evaluated by comparing it with some state of the art segmentation algorithms in case of accuracy, processing time, and performance. The accuracy was evaluated by comparing the results with the ground truth of each processed image. The experimental results clarify the effectiveness of our proposed approach to deal with a higher number of segmentation problems via improving the segmentation quality and accuracy in minimal execution time.

  2. Solving Segment Routing Problems with Hybrid Constraint Programming Techniques

    OpenAIRE

    Hartert, Renaud; Schaus, Pierre; Vissicchio, Stefano; Bonaventure, Olivier; International Conference on Principles and Practice of Constraint Programming (CP2014)

    2015-01-01

    Segment routing is an emerging network technology that exploits the existence of several paths between a source and a destination to spread the traffic in a simple and elegant way. The major commercial network vendors already support segment routing, and several Internet actors are ready to use segment routing in their network. Unfortunately, by changing the way paths are computed, segment routing poses new op- timization problems which cannot be addressed with previous research contributions...

  3. Brain tumor segmentation based on a hybrid clustering technique

    OpenAIRE

    Eman Abdel-Maksoud; Mohammed Elmogy; Rashid Al-Awadi

    2015-01-01

    Image segmentation refers to the process of partitioning an image into mutually exclusive regions. It can be considered as the most essential and crucial process for facilitating the delineation, characterization, and visualization of regions of interest in any medical image. Despite intensive research, segmentation remains a challenging problem due to the diverse image content, cluttered objects, occlusion, image noise, non-uniform object texture, and other factors. There are many algorithms...

  4. Cervical anterior hybrid technique with bi-level Bryan artificial disc replacement and adjacent segment fusion for cervical myelopathy over three consecutive segments.

    Science.gov (United States)

    Chen, Jiang; Xu, Lin; Jia, Yu-Song; Sun, Qi; Li, Jin-Yu; Zheng, Chen-Ying; Bai, Chun-Xiao; Yu, Qin-Sheng

    2016-05-01

    This study aimed to assess the preliminary clinical efficacy and feasibility of the hybrid technique for multilevel cervical myelopathy. Considering the many shortcomings of traditional treatment methods for multilevel cervical degenerative myelopathy, hybrid surgery (bi-level Bryan artificial disc [Medtronic Sofamor Danek, Memphis, TN, USA] replacement and anterior cervical discectomy and fusion) should be considered. Between March 2006 and November 2012, 108 patients (68 men and 40 women, average age 45years) underwent hybrid surgery. Based on the Japanese Orthopaedic Association (JOA) score, Neck Disability Index (NDI), and Odom's criteria, the clinical symptoms and neurological function before and after surgery were evaluated. Mean surgery duration was 90minutes, with average blood loss of 30mL. Mean follow-up duration was 36months. At the final follow-up, the mean JOA (± standard deviation) scores were significantly higher compared with preoperative values (15.08±1.47 versus 9.18±1.22; P<0.01); meanwhile, NDI values were markedly decreased (12.32±1.03 versus 42.68±1.83; P<0.01). Using Odom's criteria, the clinical outcomes were rated as excellent (76 patients), good (22 patients), fair (six patients), and poor (four patients). These findings indicate that the hybrid method provides an effective treatment for cervical myelopathy over three consecutive segments, ensuring a good clinical outcome. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Hybrid Decompression and Fixation Technique Versus Plated 3-Vertebra Corpectomy for 4-Segment Cervical Myelopathy: Analysis of 81 Cases With a Minimum 2-Year Follow-Up.

    Science.gov (United States)

    Odate, Seiichi; Shikata, Jitsuhiko; Kimura, Hiroaki; Soeda, Tsunemitsu

    2016-07-01

    A retrospective comparative study. The purpose of this study was to compare the stability and outcomes of a hybrid technique with those of a 3-vertebra corpectomy in the management of 4-segment cervical myelopathy. Patients with primarily ventral disease and loss of cervical lordosis are considered good candidates for anterior surgery. Cervical corpectomy is commonly performed in patients with multilevel cervical myelopathy. Corpectomies including >3 vertebraes entail an extremely high risk of reconstruction failure. To avoid the need to perform a 3-vertebra corpectomy, we use a hybrid decompression and fixation technique. This hybrid technique is a technique to obtain optimum decompression and fixation in patients with multilevel cervical myelopathy. A total of 81 patients with multilevel cervical myelopathy who underwent 4-segment cervical fixation with a minimum 2-year follow-up were included. The hybrid technique involved combining a plated 2-vertebra corpectomy and single-level discectomy with stand-alone cage fixation. This technique was performed in 39 patients, and the plated 3-vertebra corpectomy was performed in 42 patients. Nine patients (21%) who underwent the plated 3-vertebra corpectomy were treated with halo immobilization, but no patient in the hybrid group required this treatment (P=0.002). There were fewer instances of reconstruction failure in the hybrid group than in the 3-vertebra corpectomy group (0% vs. 10%, respectively; P=0.048) and fewer instances of C5 palsy (3% vs. 17%, respectively; P vertebra corpectomy for 4-segment cervical fixation: a shorter graft bone and plate are required; the fixed segment has greater initial stability; postoperative external immobilization is simplified; and the risk of reconstruction failure and postoperative C5 palsy is reduced markedly.

  6. A Hybrid Technique Based on Combining Fuzzy K-means Clustering and Region Growing for Improving Gray Matter and White Matter Segmentation

    Directory of Open Access Journals (Sweden)

    Ashraf Afifi

    2012-07-01

    Full Text Available In this paper we present a hybrid approach based on combining fuzzy k-means clustering, seed region growing, and sensitivity and specificity algorithms to measure gray (GM and white matter (WM tissue. The proposed algorithm uses intensity and anatomic information for segmenting of MRIs into different tissue classes, especially GM and WM. It starts by partitioning the image into different clusters using fuzzy k-means clustering. The centers of these clusters are the input to the region growing (SRG method for creating the closed regions. The outputs of SRG technique are fed to sensitivity and specificity algorithm to merge the similar regions in one segment. The proposed algorithm is applied to challenging applications: gray matter/white matter segmentation in magnetic resonance image (MRI datasets. The experimental results show that the proposed technique produces accurate and stable results.

  7. Improving Semantic Updating Method on 3d City Models Using Hybrid Semantic-Geometric 3d Segmentation Technique

    Science.gov (United States)

    Sharkawi, K.-H.; Abdul-Rahman, A.

    2013-09-01

    to LoD4. The accuracy and structural complexity of the 3D objects increases with the LoD level where LoD0 is the simplest LoD (2.5D; Digital Terrain Model (DTM) + building or roof print) while LoD4 is the most complex LoD (architectural details with interior structures). Semantic information is one of the main components in CityGML and 3D City Models, and provides important information for any analyses. However, more often than not, the semantic information is not available for the 3D city model due to the unstandardized modelling process. One of the examples is where a building is normally generated as one object (without specific feature layers such as Roof, Ground floor, Level 1, Level 2, Block A, Block B, etc). This research attempts to develop a method to improve the semantic data updating process by segmenting the 3D building into simpler parts which will make it easier for the users to select and update the semantic information. The methodology is implemented for 3D buildings in LoD2 where the buildings are generated without architectural details but with distinct roof structures. This paper also introduces hybrid semantic-geometric 3D segmentation method that deals with hierarchical segmentation of a 3D building based on its semantic value and surface characteristics, fitted by one of the predefined primitives. For future work, the segmentation method will be implemented as part of the change detection module that can detect any changes on the 3D buildings, store and retrieve semantic information of the changed structure, automatically updates the 3D models and visualize the results in a userfriendly graphical user interface (GUI).

  8. 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.

  9. Comparative genomic hybridization: Detection of segmental aneusomies

    Energy Technology Data Exchange (ETDEWEB)

    Cronin, J.E.; Magrane, G.G.; Gray, J.W. [Univ. of California, San Francisco, CA (United States)] [and others

    1994-09-01

    Comparative genomic hybridization (CGH) has been used successfully to detect whole chromosome and segmental aneusomies. However, its sensitivity for detection of segmental aneusomies is still not well known. We present here an analysis of CGH sensitivity with emphasis on detection of abnormalities commonly found during pre-and neo-natal diagnosis. CGH is performed by hybridizing green and red fluorescing test and normal DNA samples, respectively, to normal metaphase spreads and measuring green:red fluorescence ratios along all chromosomes. The ratios are normalized such that 2 copies of a normal chromosome region in the test sample gives a ratio of 1.0. Alterations in test vs. control gene copy number range from 1.5 [trisomy] to 0.5 [monosomy]. Clinical samples analyzed included Wolf Hirschhorn (4p-), Cri du Chat (5p-) and DiGeorge (22q-). In addition, 7 cell lines with chromosome 21 segmental aneusomies were analyzed. These included 3 with terminal duplications, 1 with a terminal deletion, 1 with an interstitial deletion and 2 with interstitial amplifications. The DiGeorge deletion was the only deletion not deleted by CGH. This is not surprising as standard G banding does not routinely detect this 1-2 megabase deletion. The 4p- and 5p- monosomies were detected and breakpoints correctly assigned prospectively. Proximal alterations involving 21q22.11 are unambiguously defined. Specifically, two interstitial aneusomies involving this region are detected. Studies involving late prophase chromosome normal spreads gave identical breakpoints. Thus, analysis of extended chromosomes did not improve the sensitivity of the technique. Taken together, these data suggest that CGH can detect segmental aneusomies greater than 8 megabases in extent. Smaller aneusomies can, at times, be detected. Work is now underway to modify the analysis software to increase sensitivity and to decrease the amount of material needed for analysis.

  10. Segmentation of Color Images Based on Different Segmentation Techniques

    Directory of Open Access Journals (Sweden)

    Purnashti Bhosale

    2013-03-01

    Full Text Available In this paper, we propose an Color image segmentation algorithm based on different segmentation techniques. We recognize the background objects such as the sky, ground, and trees etc based on the color and texture information using various methods of segmentation. The study of segmentation techniques by using different threshold methods such as global and local techniques and they are compared with one another so as to choose the best technique for threshold segmentation. Further segmentation is done by using clustering method and Graph cut method to improve the results of segmentation.

  11. Image Segmentation by Using Threshold Techniques

    CERN Document Server

    Al-amri, Salem Saleh; D., Khamitkar S

    2010-01-01

    This paper attempts to undertake the study of segmentation image techniques by using five threshold methods as Mean method, P-tile method, Histogram Dependent Technique (HDT), Edge Maximization Technique (EMT) and visual Technique and they are compared with one another so as to choose the best technique for threshold segmentation techniques image. These techniques applied on three satellite images to choose base guesses for threshold segmentation image.

  12. Segmented Hybrid Gasostatic Bearing Optimization

    Directory of Open Access Journals (Sweden)

    Prodan Nikolay Vasilevich

    2014-07-01

    Full Text Available The purpose of research-development of methods of numerical optimization rotatable support pads gasostatic hybrid bearing. In the world‘s aerospace engineering the gas-dynamic bearings are currently most common. They are characterized by the supporting layer of different designs, which ensures the workability of the rotors during starts and stops. The main problem of this bearing type, apart from the construction complexity is the wear of this supporting layer. Gas-static bearing has no such defect, since there is no physical contact between solid surfaces. This study presents the results of the hybrid bearing’s calculation, combining both technologies. The slotted nozzle of non-conventional shape that mirrors the solution of Reynolds equation’s isoline is studied. The dependences of the main parameters on the speed of the shaft’s rotation are discussed. The aerodynamic resistance of pads for different regimes of operation is investigated.

  13. An Approach with Hybrid Segmental Mechanics.

    Science.gov (United States)

    Mishra, Harsh Ashok; Maurya, Raj Kumar

    2016-06-01

    Present case report provides an insight into the hybrid segmental mechanics with treatment of 13-year-old male, considering the side effects of sole continuous arch wire sliding mechanics. Patient was diagnosed as a case of skeletal class I jaw relationship, low mandibular plane angle, class II molar relation on right and class I molar relation on left side, anterior cross bite, crowding of 12mm in upper, 5mm in lower arch. He also had proclined upper and lower anteriors by 2mm, convex profile and incompetent lips. Total treatment duration was 20 months, during which segmental canine retraction was performed with TMA (Titanium, Molybdenum, Aluminum) 'T' loop retraction spring followed by consolidation of spaces with continuous arch mechanics. Most of the treatment objectives were met with good intraoral and facial results within reasonable framework of time. This approach used traditional twin brackets, which offered the versatility to use continuous arch-wire mechanics, segmental mechanics and hybrid sectional mechanics.

  14. Hybrid Method for 3D Segmentation of Magnetic Resonance Images

    Institute of Scientific and Technical Information of China (English)

    ZHANGXiang; ZHANGDazhi; TIANJinwen; LIUJian

    2003-01-01

    Segmentation of some complex images, especially in magnetic resonance brain images, is often difficult to perform satisfactory results using only single approach of image segmentation. An approach towards the integration of several techniques seems to be the best solution. In this paper a new hybrid method for 3-dimension segmentation of the whole brain is introduced, based on fuzzy region growing, edge detection and mathematical morphology, The gray-level threshold, controlling the process of region growing, is determined by fuzzy technique. The image gradient feature is obtained by the 3-dimension sobel operator considering a 3×3×3 data block with the voxel to be evaluated at the center, while the gradient magnitude threshold is defined by the gradient magnitude histogram of brain magnetic resonance volume. By the combined methods of edge detection and region growing, the white matter volume of human brain is segmented perfectly. By the post-processing using mathematical morphological techniques, the whole brain region is obtained. In order to investigate the validity of the hybrid method, two comparative experiments, the region growing method using only gray-level feature and the thresholding method by combining gray-level and gradient features, are carried out. Experimental results indicate that the proposed method provides much better results than the traditional method using a single technique in the 3-dimension segmentation of human brain magnetic resonance data sets.

  15. IMPROVED HYBRID SEGMENTATION OF BRAIN MRI TISSUE AND TUMOR USING STATISTICAL FEATURES

    Directory of Open Access Journals (Sweden)

    S. Allin Christe

    2010-08-01

    Full Text Available Medical image segmentation is the most essential and crucial process in order to facilitate the characterization and visualization of the structure of interest in medical images. Relevant application in neuroradiology is the segmentation of MRI data sets of the human brain into the structure classes gray matter, white matter and cerebrospinal fluid (CSF and tumor. In this paper, brain image segmentation algorithms such as Fuzzy C means (FCM segmentation and Kohonen means(K means segmentation were implemented. In addition to this, new hybrid segmentation technique, namely, Fuzzy Kohonen means of image segmentation based on statistical feature clustering is proposed and implemented along with standard pixel value clustering method. The clustered segmented tissue images are compared with the Ground truth and its performance metric is also found. It is found that the feature based hybrid segmentation gives improved performance metric and improved classification accuracy rather than pixel based segmentation.

  16. Wavelet-based technique for target segmentation

    Science.gov (United States)

    Sadjadi, Firooz A.

    1995-07-01

    Segmentation of targets embedded in clutter obtained by IR imaging sensors is one of the challenging problems in automatic target recognition (ATR). In this paper a new texture-based segmentation technique is presented that uses the statistics of 2D wavelet decomposition components of the lcoal sections of the image. A measure of statistical similarity is then used to segment the image and separate the target from the background. This technique is applied on a set of real sequential IR imagery and has shown to produce a high degree of segmentation accuracy across varying ranges.

  17. 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

  18. Using Data Mining Techniques in Customer Segmentation

    Directory of Open Access Journals (Sweden)

    Hasan Ziafat

    2014-09-01

    Full Text Available Data mining plays important role in marketing and is quite new. Although this field expands rapidly, data mining is still foreign issue for many marketers who trust only their experiences. Data mining techniques cannot substitute the significant role of domain experts and their business knowledge. In the other words, data mining algorithms are powerful but cannot effectively work without the active support of business experts. We can gain useful results by combining these techniques and business expertise. For instance ability of a data mining technique can be substantially increased by combining person experience in the field or information of business can be integrated into a data mining model to build a more successful result. Moreover, these results should always be evaluated by business experts. Thus, business knowledge can help and enrich the data mining results. On the other hand, data mining techniques can extract patterns that even the most experienced business people may have missed. In conclusion, the combination of business domain expertise with the power of data mining techniques can help organizations gain a competitive advantage in their efforts to optimize customer management. Clustering algorithms, a group of data mining technique, is one of most common used way to segment data set according to their similarities. This paper focuses on the topic of customer segmentation using data mining techniques. In the other words, we theoretically discuss about customer relationship management and then utilize couple of data mining algorithm specially clustering techniques for customer segmentation. We concentrated on behavioral segmentation.

  19. A Hybrid Segmentation Framework for Computer-Assisted Dental Procedures

    Science.gov (United States)

    Hosntalab, Mohammad; Aghaeizadeh Zoroofi, Reza; Abbaspour Tehrani-Fard, Ali; Shirani, Gholamreza; Reza Asharif, Mohammad

    Teeth segmentation in computed tomography (CT) images is a major and challenging task for various computer assisted procedures. In this paper, we introduced a hybrid method for quantification of teeth in CT volumetric dataset inspired by our previous experiences and anatomical knowledge of teeth and jaws. In this regard, we propose a novel segmentation technique using an adaptive thresholding, morphological operations, panoramic re-sampling and variational level set algorithm. The proposed method consists of several steps as follows: first, we determine the operation region in CT slices. Second, the bony tissues are separated from other tissues by utilizing an adaptive thresholding technique based on the 3D pulses coupled neural networks (PCNN). Third, teeth tissue is classified from other bony tissues by employing panorex lines and anatomical knowledge of teeth in the jaws. In this case, the panorex lines are estimated using Otsu thresholding and mathematical morphology operators. Then, the proposed method is followed by calculating the orthogonal lines corresponding to panorex lines and panoramic re-sampling of the dataset. Separation of upper and lower jaws and initial segmentation of teeth are performed by employing the integral projections of the panoramic dataset. Based the above mentioned procedures an initial mask for each tooth is obtained. Finally, we utilize the initial mask of teeth and apply a variational level set to refine initial teeth boundaries to final contour. In the last step a surface rendering algorithm known as marching cubes (MC) is applied to volumetric visualization. The proposed algorithm was evaluated in the presence of 30 cases. Segmented images were compared with manually outlined contours. We compared the performance of segmentation method using ROC analysis of the thresholding, watershed and our previous works. The proposed method performed best. Also, our algorithm has the advantage of high speed compared to our previous works.

  20. Different Image Segmentation Techniques for Dental Image Extraction

    Directory of Open Access Journals (Sweden)

    R. Bala Subramanyam

    2014-07-01

    Full Text Available Image segmentation is the process of partitioning a digital image into multiple segments and often used to locate objects and boundaries (lines, curves etc.. In this paper, we have proposed image segmentation techniques: Region based, Texture based, Edge based. These techniques have been implemented on dental radiographs and gained good results compare to conventional technique known as Thresholding based technique. The quantitative results show the superiority of the image segmentation technique over three proposed techniques and conventional technique.

  1. Classifier Directed Data Hybridization for Geographic Sample Supervised Segment Generation

    Directory of Open Access Journals (Sweden)

    Christoff Fourie

    2014-11-01

    Full Text Available Quality segment generation is a well-known challenge and research objective within Geographic Object-based Image Analysis (GEOBIA. Although methodological avenues within GEOBIA are diverse, segmentation commonly plays a central role in most approaches, influencing and being influenced by surrounding processes. A general approach using supervised quality measures, specifically user provided reference segments, suggest casting the parameters of a given segmentation algorithm as a multidimensional search problem. In such a sample supervised segment generation approach, spatial metrics observing the user provided reference segments may drive the search process. The search is commonly performed by metaheuristics. A novel sample supervised segment generation approach is presented in this work, where the spectral content of provided reference segments is queried. A one-class classification process using spectral information from inside the provided reference segments is used to generate a probability image, which in turn is employed to direct a hybridization of the original input imagery. Segmentation is performed on such a hybrid image. These processes are adjustable, interdependent and form a part of the search problem. Results are presented detailing the performances of four method variants compared to the generic sample supervised segment generation approach, under various conditions in terms of resultant segment quality, required computing time and search process characteristics. Multiple metrics, metaheuristics and segmentation algorithms are tested with this approach. Using the spectral data contained within user provided reference segments to tailor the output generally improves the results in the investigated problem contexts, but at the expense of additional required computing time.

  2. Iris Pattern Segmentation using Automatic Segmentation and Window Technique

    OpenAIRE

    Swati Pandey; Prof. Rajeev Gupta

    2013-01-01

    A Biometric system is an automatic identification of an individual based on a unique feature or characteristic. Iris recognition has great advantage such as variability, stability and security. In thispaper, use the two methods for iris segmentation -An automatic segmentation method and Window method. Window method is a novel approach which comprises two steps first finds pupils' center andthen two radial coefficients because sometime pupil is not perfect circle. The second step extract the i...

  3. A Hybrid Method for Segmentation and Visualization of Teeth in Multi-Slice CT scan Images

    Directory of Open Access Journals (Sweden)

    Mohammad Hosntalab

    2009-12-01

    Full Text Available Introduction: Various computer assisted medical procedures such as dental implant, orthodontic planning, face, jaw and cosmetic surgeries require automatic quantification and volumetric visualization of teeth. In this regard, segmentation is a major step. Material and Methods: In this paper, inspired by our previous experiences and considering the anatomical knowledge of teeth and jaws, we propose a hybrid technique for teeth segmentation and visualization in CT volumetric data. The major steps of the proposed techniques are as follows: (1 Separation of teeth in CT dataset; (2 Initial segmentation of teeth in panoramic projection; (3 Final segmentation of teeth in CT dataset; (4 3D visualization of teeth. Results: The proposed algorithm was evaluated in 30 multi-slice CT datasets. Segmented images were compared with manually outlined contours. In order to evaluate the proposed method, we utilized several common performance measures such as sensitivity, specificity, precision, accuracy and mean error rate. The experimental results reveal the effectiveness of the proposed method. Discussion and Conclusion: In the proposed algorithm, the variationallevel set technique was utilized to trace the contour of the teeth. In view of the fact that this technique is based on the characteristics of the overall region of the tooth image, it is possible to extract a very smooth and accurate tooth contour using this technique. For the available datasets, the proposed technique was more successful in teeth segmentation compared to previous techniques.

  4. FIST: a fast interactive segmentation technique

    Science.gov (United States)

    Padfield, Dirk; Bhotika, Rahul; Natanzon, Alexander

    2015-03-01

    Radiologists are required to read thousands of patient images every day, and any tools that can improve their workflow to help them make efficient and accurate measurements is of great value. Such an interactive tool must be intuitive to use, and we have found that users are accustomed to clicking on the contour of the object for segmentation and would like the final segmentation to pass through these points. The tool must also be fast to enable real-time interactive feedback. To meet these needs, we present a segmentation workflow that enables an intuitive method for fast interactive segmentation of 2D and 3D objects. Given simple user clicks on the contour of an object in one 2D view, the algorithm generates foreground and background seeds and computes foreground and background distributions that are used to segment the object in 2D. It then propagates the information to the two orthogonal planes in a 3D volume and segments all three 2D views. The automated segmentation is automatically updated as the user continues to add points around the contour, and the algorithm is re-run using the total set of points. Based on the segmented objects in these three views, the algorithm then computes a 3D segmentation of the object. This process requires only limited user interaction to segment complex shapes and significantly improves the workflow of the user.

  5. Atlas-Based Prostate Segmentation Using an Hybrid Registration

    CERN Document Server

    Martin, Sébastien; Troccaz, Jocelyne

    2008-01-01

    Purpose: This paper presents the preliminary results of a semi-automatic method for prostate segmentation of Magnetic Resonance Images (MRI) which aims to be incorporated in a navigation system for prostate brachytherapy. Methods: The method is based on the registration of an anatomical atlas computed from a population of 18 MRI exams onto a patient image. An hybrid registration framework which couples an intensity-based registration with a robust point-matching algorithm is used for both atlas building and atlas registration. Results: The method has been validated on the same dataset that the one used to construct the atlas using the "leave-one-out method". Results gives a mean error of 3.39 mm and a standard deviation of 1.95 mm with respect to expert segmentations. Conclusions: We think that this segmentation tool may be a very valuable help to the clinician for routine quantitative image exploitation.

  6. Optical image segmentation using wavelet filtering techniques

    Science.gov (United States)

    Veronin, Christopher P.

    1990-12-01

    This research effort successfully implemented an automatic, optically based image segmentation scheme for locating potential targets in a cluttered FLIR image. Such a design is critical to achieve real-time segmentation and classification for machine vision applications. The segmentation scheme used in this research was based on texture discrimination and employs orientation specific, bandpass spatial filters as its main component. The orientation specific, bandpass spatial filters designed during this research include symmetrically located circular apertures implemented on heavy, black aluminum foil; cosine and sine Gabor filters implemented with detour-phase computer generated holography photoreduced onto glass slides; and symmetrically located circular apertures implemented on a liquid crystal television (LCTV) for real-time filter selection. The most successful design was the circular aperture pairs implemented on the aluminum foil. Segmentation was illustrated for simple and complex texture slides, glass template slides, and static and real-time FLIR imagery displayed on an LCTV.

  7. Brain anatomical structure segmentation by hybrid discriminative/generative models.

    Science.gov (United States)

    Tu, Z; Narr, K L; Dollar, P; Dinov, I; Thompson, P M; Toga, A W

    2008-04-01

    In this paper, a hybrid discriminative/generative model for brain anatomical structure segmentation is proposed. The learning aspect of the approach is emphasized. In the discriminative appearance models, various cues such as intensity and curvatures are combined to locally capture the complex appearances of different anatomical structures. A probabilistic boosting tree (PBT) framework is adopted to learn multiclass discriminative models that combine hundreds of features across different scales. On the generative model side, both global and local shape models are used to capture the shape information about each anatomical structure. The parameters to combine the discriminative appearance and generative shape models are also automatically learned. Thus, low-level and high-level information is learned and integrated in a hybrid model. Segmentations are obtained by minimizing an energy function associated with the proposed hybrid model. Finally, a grid-face structure is designed to explicitly represent the 3-D region topology. This representation handles an arbitrary number of regions and facilitates fast surface evolution. Our system was trained and tested on a set of 3-D magnetic resonance imaging (MRI) volumes and the results obtained are encouraging.

  8. A Survey on Image Segmentation Techniques Used In Leukemia Detection

    Directory of Open Access Journals (Sweden)

    Mashiat Fatma

    2014-04-01

    Full Text Available Image segmentation commonly known as partitioning of an image is one of the intrinsic parts of any image processing technique. In this image processing step, the digital image of choice is segregated into sets of pixels on the basis of some predefined and preselected measures or standards. There have been presented many algorithms for segmenting a digital image. This paper presents a general review of algorithms that have been presented for the purpose of image segmentation.

  9. A Hough Transform based Technique for Text Segmentation

    CERN Document Server

    Saha, Satadal; Nasipuri, Mita; Basu, Dipak Kr

    2010-01-01

    Text segmentation is an inherent part of an OCR system irrespective of the domain of application of it. The OCR system contains a segmentation module where the text lines, words and ultimately the characters must be segmented properly for its successful recognition. The present work implements a Hough transform based technique for line and word segmentation from digitized images. The proposed technique is applied not only on the document image dataset but also on dataset for business card reader system and license plate recognition system. For standardization of the performance of the system the technique is also applied on public domain dataset published in the website by CMATER, Jadavpur University. The document images consist of multi-script printed and hand written text lines with variety in script and line spacing in single document image. The technique performs quite satisfactorily when applied on mobile camera captured business card images with low resolution. The usefulness of the technique is verifie...

  10. A Survey Paper on Fuzzy Image Segmentation Techniques

    Directory of Open Access Journals (Sweden)

    Ms. R. Saranya Pon Selvi

    2014-03-01

    Full Text Available The image segmentation plays an important role in the day-to-day life. The new technologies are emerging in the field of Image processing, especially in the domain of segmentation.Segmentation is considered as one of the main steps in image processing. It divides a digital image into multiple regions in order to analyze them. It is also used to distinguish different objects in the image. Several image segmentation techniques have been developed by the researchers in order to make images smooth and easy to evaluate. This paper presents a brief outline on some of the most commonly used segmentation techniques like thresholding, Region based, Model based, Edge detection..etc. mentioning its advantages as well as the drawbacks. Some of the techniques are suitable for noisy images.

  11. Hybrid PET/MRI co-segmentation based on joint fuzzy connectedness and graph cut.

    Science.gov (United States)

    Sbei, Arafet; ElBedoui, Khaoula; Barhoumi, Walid; Maksud, Philippe; Maktouf, Chokri

    2017-10-01

    Tumor segmentation from hybrid PET/MRI scans may be highly beneficial in radiotherapy treatment planning. Indeed, it gives for both modalities the suitable information that could make the delineation of tumors more accurate than using each one apart. We aim in this work to propose a co-segmentation method that deals with several challenges, notably the lack of one-to-one correspondence between tumors of the two modalities and the boundaries' smoothing. The proposed method is designed to surpass these limits, we propose a segmentation method based on the GCsum(max) technique. The method takes the advantage of Iterative Relative Fuzzy Connectedness (IRFC) on seeds initialization, and the standard min-cut/max-flow technique for the boundary smoothing. Seed initialization was accurately performed thanks to high uptake regions on PET. Besides, a visibility weighting scheme was adapted to achieve the task of co-segmentation using the IRFC algorithm. Then, given the co-segmented regions, we introduce a morphological-based technique that provides object seeds to standard Graph Cut (GC) allowing it to avoid the shrinking problem. Finally, for each modality, the segmentation task is formulated as an energy minimization problem which is resolved by a min-cut/max-flow technique. The overlap ratio (denoted DSC) between our segmentation results and the ground-truth for PET images is 92.63  ±  1.03, while the DSC for MRI images is 90.61  ±  3.70. The proposed method was tested on different types of diseases and it outperformed the state-of-the-art methods. We show its superiority in terms of assymetric relation between PET and MRI and tumors heterogeneity. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Segmentation techniques for extracting humans from thermal images

    CSIR Research Space (South Africa)

    Dickens, JS

    2011-11-01

    Full Text Available A pedestrian detection system for underground mine vehicles is being developed that requires the segmentation of people from thermal images in underground mine tunnels. A number of thresholding techniques are outlined and their performance on a...

  13. IMAGE SEGMENTATION BASED ON MARKOV RANDOM FIELD AND WATERSHED TECHNIQUES

    Institute of Scientific and Technical Information of China (English)

    纳瑟; 刘重庆

    2002-01-01

    This paper presented a method that incorporates Markov Random Field(MRF), watershed segmentation and merging techniques for performing image segmentation and edge detection tasks. MRF is used to obtain an initial estimate of x regions in the image under process where in MRF model, gray level x, at pixel location i, in an image X, depends on the gray levels of neighboring pixels. The process needs an initial segmented result. An initial segmentation is got based on K-means clustering technique and the minimum distance, then the region process in modeled by MRF to obtain an image contains different intensity regions. Starting from this we calculate the gradient values of that image and then employ a watershed technique. When using MRF method it obtains an image that has different intensity regions and has all the edge and region information, then it improves the segmentation result by superimpose closed and an accurate boundary of each region using watershed algorithm. After all pixels of the segmented regions have been processed, a map of primitive region with edges is generated. Finally, a merge process based on averaged mean values is employed. The final segmentation and edge detection result is one closed boundary per actual region in the image.

  14. SAR Image Segmentation using Vector Quantization Technique on Entropy Images

    CERN Document Server

    Kekre, H B; Sarode, Tanuja K

    2010-01-01

    The development and application of various remote sensing platforms result in the production of huge amounts of satellite image data. Therefore, there is an increasing need for effective querying and browsing in these image databases. In order to take advantage and make good use of satellite images data, we must be able to extract meaningful information from the imagery. Hence we proposed a new algorithm for SAR image segmentation. In this paper we propose segmentation using vector quantization technique on entropy image. Initially, we obtain entropy image and in second step we use Kekre's Fast Codebook Generation (KFCG) algorithm for segmentation of the entropy image. Thereafter, a codebook of size 128 was generated for the Entropy image. These code vectors were further clustered in 8 clusters using same KFCG algorithm and converted into 8 images. These 8 images were displayed as a result. This approach does not lead to over segmentation or under segmentation. We compared these results with well known Gray L...

  15. Segmented arch or continuous arch technique? A rational approach

    Directory of Open Access Journals (Sweden)

    Sergei Godeiro Fernandes Rabelo Caldas

    2014-04-01

    Full Text Available This study aims at revising the biomechanical principles of the segmented archwire technique as well as describing the clinical conditions in which the rational use of scientific biomechanics is essential to optimize orthodontic treatment and reduce the side effects produced by the straight wire technique.

  16. Stochastic segmentation models for array-based comparative genomic hybridization data analysis.

    Science.gov (United States)

    Lai, Tze Leung; Xing, Haipeng; Zhang, Nancy

    2008-04-01

    Array-based comparative genomic hybridization (array-CGH) is a high throughput, high resolution technique for studying the genetics of cancer. Analysis of array-CGH data typically involves estimation of the underlying chromosome copy numbers from the log fluorescence ratios and segmenting the chromosome into regions with the same copy number at each location. We propose for the analysis of array-CGH data, a new stochastic segmentation model and an associated estimation procedure that has attractive statistical and computational properties. An important benefit of this Bayesian segmentation model is that it yields explicit formulas for posterior means, which can be used to estimate the signal directly without performing segmentation. Other quantities relating to the posterior distribution that are useful for providing confidence assessments of any given segmentation can also be estimated by using our method. We propose an approximation method whose computation time is linear in sequence length which makes our method practically applicable to the new higher density arrays. Simulation studies and applications to real array-CGH data illustrate the advantages of the proposed approach.

  17. Segmental Refinement: A Multigrid Technique for Data Locality

    KAUST Repository

    Adams, Mark F.

    2016-08-04

    We investigate a domain decomposed multigrid technique, termed segmental refinement, for solving general nonlinear elliptic boundary value problems. We extend the method first proposed in 1994 by analytically and experimentally investigating its complexity. We confirm that communication of traditional parallel multigrid is eliminated on fine grids, with modest amounts of extra work and storage, while maintaining the asymptotic exactness of full multigrid. We observe an accuracy dependence on the segmental refinement subdomain size, which was not considered in the original analysis. We present a communication complexity analysis that quantifies the communication costs ameliorated by segmental refinement and report performance results with up to 64K cores on a Cray XC30.

  18. A Comparison of X-Ray Image Segmentation Techniques

    Directory of Open Access Journals (Sweden)

    STOLOJESCU-CRISAN, C.

    2013-08-01

    Full Text Available Image segmentation operation has a great importance in most medical imaging applications, by extracting anatomical structures from medical images. There are many image segmentation techniques available in the literature, each of them having advantages and disadvantages. The extraction of bone contours from X-ray images has received a considerable amount of attention in the literature recently, because they represent a vital step in the computer analysis of this kind of images. The aim of X-ray segmentation is to subdivide the image in various portions, so that it can help doctors during the study of the bone structure, for the detection of fractures in bones, or for planning the treatment before surgery. The goal of this paper is to review the most important image segmentation methods starting from a data base composed by real X-ray images. We will discuss the principle and the mathematical model for each method, highlighting the strengths and weaknesses.

  19. Improved object segmentation using Markov random fields, artificial neural networks, and parallel processing techniques

    Science.gov (United States)

    Foulkes, Stephen B.; Booth, David M.

    1997-07-01

    Object segmentation is the process by which a mask is generated which identifies the area of an image which is occupied by an object. Many object recognition techniques depend on the quality of such masks for shape and underlying brightness information, however, segmentation remains notoriously unreliable. This paper considers how the image restoration technique of Geman and Geman can be applied to the improvement of object segmentations generated by a locally adaptive background subtraction technique. Also presented is how an artificial neural network hybrid, consisting of a single layer Kohonen network with each of its nodes connected to a different multi-layer perceptron, can be used to approximate the image restoration process. It is shown that the restoration techniques are very well suited for parallel processing and in particular the artificial neural network hybrid has the potential for near real time image processing. Results are presented for the detection of ships in SPOT panchromatic imagery and the detection of vehicles in infrared linescan images, these being a fair representation of the wider class of problem.

  20. Technique for Measuring Hybrid Electronic Component Reliability

    Energy Technology Data Exchange (ETDEWEB)

    Green, C.C.; Hernandez, C.L.; Hosking, F.M.; Robinson, D.; Rutherford, B.; Uribe, F.

    1999-01-01

    Materials compatibility studies of aged, engineered materials and hardware are critical to understanding and predicting component reliability, particularly for systems with extended stockpile life requirements. Nondestructive testing capabilities for component reliability would significantly enhance lifetime predictions. For example, if the detection of crack propagation through a solder joint can be demonstrated, this technique could be used to develop baseline information to statistically determine solder joint lifelengths. This report will investigate high frequency signal response techniques for nondestructively evaluating the electrical behavior of thick film hybrid transmission lines.

  1. SAR Image Segmentation Based On Hybrid PSOGSA Optimization Algorithm

    Directory of Open Access Journals (Sweden)

    Amandeep Kaur

    2014-09-01

    Full Text Available Image segmentation is useful in many applications. It can identify the regions of interest in a scene or annotate the data. It categorizes the existing segmentation algorithm into region-based segmentation, data clustering, and edge-base segmentation. Region-based segmentation includes the seeded and unseeded region growing algorithms, the JSEG, and the fast scanning algorithm. Due to the presence of speckle noise, segmentation of Synthetic Aperture Radar (SAR images is still a challenging problem. We proposed a fast SAR image segmentation method based on Particle Swarm Optimization-Gravitational Search Algorithm (PSO-GSA. In this method, threshold estimation is regarded as a search procedure that examinations for an appropriate value in a continuous grayscale interval. Hence, PSO-GSA algorithm is familiarized to search for the optimal threshold. Experimental results indicate that our method is superior to GA based, AFS based and ABC based methods in terms of segmentation accuracy, segmentation time, and Thresholding.

  2. Hybrid ultrasound imaging techniques (fusion imaging).

    Science.gov (United States)

    Sandulescu, Daniela Larisa; Dumitrescu, Daniela; Rogoveanu, Ion; Saftoiu, Adrian

    2011-01-07

    Visualization of tumor angiogenesis can facilitate non-invasive evaluation of tumor vascular characteristics to supplement the conventional diagnostic imaging goals of depicting tumor location, size, and morphology. Hybrid imaging techniques combine anatomic [ultrasound, computed tomography (CT), and/or magnetic resonance imaging (MRI)] and molecular (single photon emission CT and positron emission tomography) imaging modalities. One example is real-time virtual sonography, which combines ultrasound (grayscale, colour Doppler, or dynamic contrast harmonic imaging) with contrast-enhanced CT/MRI. The benefits of fusion imaging include an increased diagnostic confidence, direct comparison of the lesions using different imaging modalities, more precise monitoring of interventional procedures, and reduced radiation exposure.

  3. New real time needle segmentation technique using grayscale Hough transformation

    Science.gov (United States)

    Qiu, Wu; Zhou, Hua; Ding, Mingyue; Zhang, Songgeng

    2007-12-01

    Real-time needle segmentation and tracking is very important in image-guided surgery, biopsy, and therapy. In this paper, we described an automated technique to provide real-time needle segmentation from a sequence of 2-D ultrasound images for the use of guidance of a needle to the target in soft tissues. The Hough transform is used to find straight lines or analytic curves in binary image. Hough transform is applied usually to binary images. Hence one needs to convert, initially, the gray level image to a binary one (through thresholding, edge detection, or thinning) in order to apply the HT. While in the process of binarization, some information about line segments in the image may be lost when an inappropriate threshold is used. Gray-Scale Hough Transform can detect the line without binarization. Unfortunately, its high computational cost often prevents it from being applied in real-time applications without the help of specially designed hardware. In this paper, we proposed a needle segmentation technique based on a real-time gray-scale Hough transform. It is composed of an improved Gray Hough Transformation and a coarse-fine search strategy. Furthermore, the RTGHT (Real-Time Gray-Scale Hough Transform) technique is evaluated by patient breast biopsy images. Experiments with patient breast biopsy ultrasound (US) image sequences showed that our approach can segment the biopsy needle in real time (i.e., less than 60 ms) with the angular rms error of about 1° and the position rms error of about 0.5 mm an affordable PC computer without the help of specially designed hardware.

  4. Segmental Refinement: A Multigrid Technique for Data Locality

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Mark [Columbia Univ., New York, NY (United States). Applied Physics and Applied Mathematics Dept.; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-10-27

    We investigate a technique - segmental refinement (SR) - proposed by Brandt in the 1970s as a low memory multigrid method. The technique is attractive for modern computer architectures because it provides high data locality, minimizes network communication, is amenable to loop fusion, and is naturally highly parallel and asynchronous. The network communication minimization property was recognized by Brandt and Diskin in 1994; we continue this work by developing a segmental refinement method for a finite volume discretization of the 3D Laplacian on massively parallel computers. An understanding of the asymptotic complexities, required to maintain textbook multigrid efficiency, are explored experimentally with a simple SR method. A two-level memory model is developed to compare the asymptotic communication complexity of a proposed SR method with traditional parallel multigrid. Performance and scalability are evaluated with a Cray XC30 with up to 64K cores. We achieve modest improvement in scalability from traditional parallel multigrid with a simple SR implementation.

  5. Hybrid ultrasound imaging techniques(fusion imaging)

    Institute of Scientific and Technical Information of China (English)

    Daniela Larisa Sandulescu; Daniela Dumitrescu; Ion Rogoveanu; Adrian Saftoiu

    2011-01-01

    Visualization of tumor angiogenesis can facilitate noninvasive evaluation of tumor vascular characteristics to supplement the conventional diagnostic imaging goals of depicting tumor location,size,and morphology.Hybrid imaging techniques combine anatomic [ultrasound,computed tomography(CT),and/or magnetic resonance imaging(MRI)] and molecular(single photon emission CT and positron emission tomography)imaging modalities.One example is real-time virtual sonography,which combines ultrasound(grayscale,colour Doppler,or dynamic contrast harmonic imaging)with contrast-enhanced CT/MRI.The benefits of fusion imaging include an increased diagnostic confidence,direct comparison of the lesions using different imaging modalities,more precise monitoring of interventional procedures,and reduced radiation exposure.

  6. HYBRID INTERNET TRAFFIC CLASSIFICATION TECHNIQUE1

    Institute of Scientific and Technical Information of China (English)

    Li Jun; Zhang Shunyi; Lu Yanqing; Yan Junrong

    2009-01-01

    Accurate and real-time classification of network traffic is significant to network operation and management such as QoS differentiation, traffic shaping and security surveillance. However, with many newly emerged P2P applications using dynamic port numbers, masquerading techniques, and payload encryption to avoid detection, traditional classification approaches turn to be ineffective. In this paper, we present a layered hybrid system to classify current Internet traffic, motivated by variety of network activities and their requirements of traffic classification. The proposed method could achieve fast and accurate traffic classification with low overheads and robustness to accommodate both known and unknown/encrypted applications. Furthermore, it is feasible to be used in the context of real-time traffic classification. Our experimental results show the distinct advantages of the proposed classification system, compared with the one-step Machine Learning (ML) approach.

  7. Motion segmentation method for hybrid characteristic on human motion.

    Science.gov (United States)

    Lau, Newman; Wong, Ben; Chow, Daniel

    2009-03-11

    Motion segmentation and analysis are used to improve the process of classification of motion and information gathered on repetitive or periodic characteristic. The classification result is useful for ergonomic and postural safety analysis, since repetitive motion is known to be related to certain musculoskeletal disorders. Past studies mainly focused on motion segmentation on particular motion characteristic with certain prior knowledge on static or periodic property of motion, which narrowed method's applicability. This paper attempts to introduce a method to tackle human joint motion without having prior knowledge. The motion is segmented by a two-pass algorithm. Recursive least square (RLS) is firstly used to estimate possible segments on the input human-motion set. Further, period identification and extra segmentation process are applied to produce meaningful segments. Each of the result segments is modeled by a damped harmonic model, with frequency, amplitude and duration produced as parameters for ergonomic evaluation and other human factor studies such as task safety evaluation and sport analysis. Experiments show that the method can handle periodic, random and mixed characteristics on human motion, which can also be extended to the usage in repetitive motion in workflow and irregular periodic motion like sport movement.

  8. 3D Medical Volume Segmentation Using Hybrid Multiresolution Statistical Approaches

    Directory of Open Access Journals (Sweden)

    Shadi AlZu'bi

    2010-01-01

    that 3D methodologies can accurately detect the Region Of Interest (ROI. Automatic segmentation has been achieved using HMMs where the ROI is detected accurately but suffers a long computation time for its calculations.

  9. A Hybrid 3D Learning-and-Interaction-based Segmentation Approach Applied on CT Liver Volumes

    Directory of Open Access Journals (Sweden)

    M. Danciu

    2013-04-01

    Full Text Available Medical volume segmentation in various imaging modalities using real 3D approaches (in contrast to slice-by-slice segmentation represents an actual trend. The increase in the acquisition resolution leads to large amount of data, requiring solutions to reduce the dimensionality of the segmentation problem. In this context, the real-time interaction with the large medical data volume represents another milestone. This paper addresses the twofold problem of the 3D segmentation applied to large data sets and also describes an intuitive neuro-fuzzy trained interaction method. We present a new hybrid semi-supervised 3D segmentation, for liver volumes obtained from computer tomography scans. This is a challenging medical volume segmentation task, due to the acquisition and inter-patient variability of the liver parenchyma. The proposed solution combines a learning-based segmentation stage (employing 3D discrete cosine transform and a probabilistic support vector machine classifier with a post-processing stage (automatic and manual segmentation refinement. Optionally, an optimization of the segmentation can be achieved by level sets, using as initialization the segmentation provided by the learning-based solution. The supervised segmentation is applied on elementary cubes in which the CT volume is decomposed by tilling, thus ensuring a significant reduction of the data to be classified by the support vector machine into liver/not liver. On real volumes, the proposed approach provides good segmentation accuracy, with a significant reduction in the computational complexity.

  10. Hybrid of Fuzzy Logic and Random Walker Method for Medical Image Segmentation

    National Research Council Canada - National Science Library

    Jasdeep Kaur; Manish Mahajan

    2015-01-01

    ...’ treatment are based on information extracted from radiological images. Several algorithms and techniques have developed for image segmentation and have their own advantages and disadvantages...

  11. A New Generic Taxonomy on Hybrid Malware Detection Technique

    CERN Document Server

    Robiah, Y; Zaki, M Mohd; Shahrin, S; Faizal, M A; Marliza, R

    2009-01-01

    Malware is a type of malicious program that replicate from host machine and propagate through network. It has been considered as one type of computer attack and intrusion that can do a variety of malicious activity on a computer. This paper addresses the current trend of malware detection techniques and identifies the significant criteria in each technique to improve malware detection in Intrusion Detection System (IDS). Several existing techniques are analyzing from 48 various researches and the capability criteria of malware detection technique have been reviewed. From the analysis, a new generic taxonomy of malware detection technique have been proposed named Hybrid Malware Detection Technique (Hybrid MDT) which consists of Hybrid Signature and Anomaly detection technique and Hybrid Specification based and Anomaly detection technique to complement the weaknesses of the existing malware detection technique in detecting known and unknown attack as well as reducing false alert before and during the intrusion ...

  12. A hybrid algorithm for the segmentation of books in libraries

    Science.gov (United States)

    Hu, Zilong; Tang, Jinshan; Lei, Liang

    2016-05-01

    This paper proposes an algorithm for book segmentation based on bookshelves images. The algorithm can be separated into three parts. The first part is pre-processing, aiming at eliminating or decreasing the effect of image noise and illumination conditions. The second part is near-horizontal line detection based on Canny edge detector, and separating a bookshelves image into multiple sub-images so that each sub-image contains an individual shelf. The last part is book segmentation. In each shelf image, near-vertical line is detected, and obtained lines are used for book segmentation. The proposed algorithm was tested with the bookshelf images taken from OPIE library in MTU, and the experimental results demonstrate good performance.

  13. Hybridizing Differential Evolution with a Genetic Algorithm for Color Image Segmentation

    Directory of Open Access Journals (Sweden)

    R. V. V. Krishna

    2016-10-01

    Full Text Available This paper proposes a hybrid of differential evolution and genetic algorithms to solve the color image segmentation problem. Clustering based color image segmentation algorithms segment an image by clustering the features of color and texture, thereby obtaining accurate prototype cluster centers. In the proposed algorithm, the color features are obtained using the homogeneity model. A new texture feature named Power Law Descriptor (PLD which is a modification of Weber Local Descriptor (WLD is proposed and further used as a texture feature for clustering. Genetic algorithms are competent in handling binary variables, while differential evolution on the other hand is more efficient in handling real parameters. The obtained texture feature is binary in nature and the color feature is a real value, which suits very well the hybrid cluster center optimization problem in image segmentation. Thus in the proposed algorithm, the optimum texture feature centers are evolved using genetic algorithms, whereas the optimum color feature centers are evolved using differential evolution.

  14. Application of hybrid techniques (self-organizing map and fuzzy algorithm) using backscatter data for segmentation and fine-scale roughness characterization of seepage-related seafloor along the western continental margin of India

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, B.; Menezes, A.A.A.; Dandapath, S.; Fernandes, W.A.; Karisiddaiah, S.M.; Haris, K.; Gokul, G.S.

    (involving pockmarks and faulted structures) subjected to strong bottom currents and seasonal upwelling. Index Terms ─ Multi-beam backscatter, Seafloor classification and characterizations, Self-Organizing map (SOM), Fuzzy C- means (FCM), Power spectral..., ANN techniques were proposed for hydro-acoustic data classification [10]. The SOM exercises unsupervised competitive learning on the unknown dataset (input) onto coarser clusters i.e., primary classifications [11]. For real time survey applications...

  15. Lung segmentation refinement based on optimal surface finding utilizing a hybrid desktop/virtual reality user interface.

    Science.gov (United States)

    Sun, Shanhui; Sonka, Milan; Beichel, Reinhard R

    2013-01-01

    Recently, the optimal surface finding (OSF) and layered optimal graph image segmentation of multiple objects and surfaces (LOGISMOS) approaches have been reported with applications to medical image segmentation tasks. While providing high levels of performance, these approaches may locally fail in the presence of pathology or other local challenges. Due to the image data variability, finding a suitable cost function that would be applicable to all image locations may not be feasible. This paper presents a new interactive refinement approach for correcting local segmentation errors in the automated OSF-based segmentation. A hybrid desktop/virtual reality user interface was developed for efficient interaction with the segmentations utilizing state-of-the-art stereoscopic visualization technology and advanced interaction techniques. The user interface allows a natural and interactive manipulation of 3-D surfaces. The approach was evaluated on 30 test cases from 18 CT lung datasets, which showed local segmentation errors after employing an automated OSF-based lung segmentation. The performed experiments exhibited significant increase in performance in terms of mean absolute surface distance errors (2.54±0.75 mm prior to refinement vs. 1.11±0.43 mm post-refinement, p≪0.001). Speed of the interactions is one of the most important aspects leading to the acceptance or rejection of the approach by users expecting real-time interaction experience. The average algorithm computing time per refinement iteration was 150 ms, and the average total user interaction time required for reaching complete operator satisfaction was about 2 min per case. This time was mostly spent on human-controlled manipulation of the object to identify whether additional refinement was necessary and to approve the final segmentation result. The reported principle is generally applicable to segmentation problems beyond lung segmentation in CT scans as long as the underlying segmentation utilizes the

  16. Wind Speed Forecasting Using Hybrid Wavelet Transform—ARMA Techniques

    Directory of Open Access Journals (Sweden)

    Diksha Kaur

    2015-01-01

    Full Text Available The objective of this paper is to develop a novel wind speed forecasting technique, which produces more accurate prediction. The Wavelet Transform (WT along with the Auto Regressive Moving Average (ARMA is chosen to form a hybrid whose combination is expected to give minimum Mean Absolute Prediction Error (MAPE. A simulation study has been conducted by comparing the forecasting results using the Wavelet-ARMA with the ARMA and Artificial Neural Network (ANN-Ensemble Kalman Filter (EnKF hybrid technique to verify the effectiveness of the proposed hybrid method. Results of the proposed hybrid show significant improvements in the forecasting error.

  17. Quantitative evaluation of six graph based semi-automatic liver tumor segmentation techniques using multiple sets of reference segmentation

    Science.gov (United States)

    Su, Zihua; Deng, Xiang; Chefd'hotel, Christophe; Grady, Leo; Fei, Jun; Zheng, Dong; Chen, Ning; Xu, Xiaodong

    2011-03-01

    Graph based semi-automatic tumor segmentation techniques have demonstrated great potential in efficiently measuring tumor size from CT images. Comprehensive and quantitative validation is essential to ensure the efficacy of graph based tumor segmentation techniques in clinical applications. In this paper, we present a quantitative validation study of six graph based 3D semi-automatic tumor segmentation techniques using multiple sets of expert segmentation. The six segmentation techniques are Random Walk (RW), Watershed based Random Walk (WRW), LazySnapping (LS), GraphCut (GHC), GrabCut (GBC), and GrowCut (GWC) algorithms. The validation was conducted using clinical CT data of 29 liver tumors and four sets of expert segmentation. The performance of the six algorithms was evaluated using accuracy and reproducibility. The accuracy was quantified using Normalized Probabilistic Rand Index (NPRI), which takes into account of the variation of multiple expert segmentations. The reproducibility was evaluated by the change of the NPRI from 10 different sets of user initializations. Our results from the accuracy test demonstrated that RW (0.63) showed the highest NPRI value, compared to WRW (0.61), GWC (0.60), GHC (0.58), LS (0.57), GBC (0.27). The results from the reproducibility test indicated that GBC is more sensitive to user initialization than the other five algorithms. Compared to previous tumor segmentation validation studies using one set of reference segmentation, our evaluation methods use multiple sets of expert segmentation to address the inter or intra rater variability issue in ground truth annotation, and provide quantitative assessment for comparing different segmentation algorithms.

  18. Hybrid artificial neural network segmentation and classification of dynamic contrast-enhanced MR imaging (DEMRI) of osteosarcoma.

    Science.gov (United States)

    Glass, J O; Reddick, W E

    1998-11-01

    The evaluation of pediatric osteosarcoma has suffered from the lack of an accurate imaging measure of response. One major problem is that osteosarcoma do not shrink in response to chemotherapy; instead, viable tumor is replaced by necrotic tissue. Currently available techniques that use dynamic contrast-enhanced magnetic resonance imaging to quantitatively evaluate tumor response fail to assess the percentage of necrosis. At present, histopathologic evaluation of resected tissue is the only means of measuring the percentage of necrosis in treated osteosarcoma. The current study presents a non-invasive method to visualize necrotic and viable tumor and quantitatively assess the response of osteosarcoma. Our technique uses a hybrid neural network consisting of a Kohonen self-organizing map to segment dynamic contrast-enhanced magnetic resonance images and a multi-layer backpropagation neural network to classify the segmented images. Because the hybrid neural network is completely automated, our technique removes both inter- and intra-operator error. An analysis comparing the percentage of necrosis from our technique to the histopathologic analysis revealed a highly significant Spearman correlation coefficient of 0.617 with p < 0.001.

  19. Hybrid of Fuzzy Logic and Random Walker Method for Medical Image Segmentation

    OpenAIRE

    Jasdeep Kaur; Manish Mahajan

    2015-01-01

    The procedure of partitioning an image into various segments to reform an image into somewhat that is more significant and easier to analyze, defined as image segmentation. In real world applications, noisy images exits and there could be some measurement errors too. These factors affect the quality of segmentation, which is of major concern in medical fields where decisions about patients’ treatment are based on information extracted from radiological images. Several algorithms and technique...

  20. Hybrid Clustering And Boundary Value Refinement for Tumor Segmentation using Brain MRI

    Science.gov (United States)

    Gupta, Anjali; Pahuja, Gunjan

    2017-08-01

    The method of brain tumor segmentation is the separation of tumor area from Brain Magnetic Resonance (MR) images. There are number of methods already exist for segmentation of brain tumor efficiently. However it’s tedious task to identify the brain tumor from MR images. The segmentation process is extraction of different tumor tissues such as active, tumor, necrosis, and edema from the normal brain tissues such as gray matter (GM), white matter (WM), as well as cerebrospinal fluid (CSF). As per the survey study, most of time the brain tumors are detected easily from brain MR image using region based approach but required level of accuracy, abnormalities classification is not predictable. The segmentation of brain tumor consists of many stages. Manually segmenting the tumor from brain MR images is very time consuming hence there exist many challenges in manual segmentation. In this research paper, our main goal is to present the hybrid clustering which consists of Fuzzy C-Means Clustering (for accurate tumor detection) and level set method(for handling complex shapes) for the detection of exact shape of tumor in minimal computational time. using this approach we observe that for a certain set of images 0.9412 sec of time is taken to detect tumor which is very less in comparison to recent existing algorithm i.e. Hybrid clustering (Fuzzy C-Means and K Means clustering).

  1. A HYBRID FIREFLY ALGORITHM WITH FUZZY-C MEAN ALGORITHM FOR MRI BRAIN SEGMENTATION

    Directory of Open Access Journals (Sweden)

    Mutasem K. Alsmadi

    2014-01-01

    Full Text Available Image processing is one of the essential tasks to extract suspicious region and robust features from the Magnetic Resonance Imaging (MRI. A numbers of the segmentation algorithms were developed in order to satisfy and increasing the accuracy of brain tumor detection. In the medical image processing brain image segmentation is considered as a complex and challenging part. Fuzzy c-means is unsupervised method that has been implemented for clustering of the MRI and different purposes such as recognition of the pattern of interest and image segmentation. However; fuzzy c-means algorithm still suffers many drawbacks, such as low convergence rate, getting stuck in the local minima and vulnerable to initialization sensitivity. Firefly algorithm is a new population-based optimization method that has been used successfully for solving many complex problems. This paper proposed a new dynamic and intelligent clustering method for brain tumor segmentation using the hybridization of Firefly Algorithm (FA with Fuzzy C-Means algorithm (FCM. In order to automatically segment MRI brain images and improve the capability of the FCM to automatically elicit the proper number and location of cluster centres and the number of pixels in each cluster in the abnormal (multiple sclerosis lesions MRI images. The experimental results proved the effectiveness of the proposed FAFCM in enhancing the performance of the traditional FCM clustering. Moreover; the superiority of the FAFCM with other state-of-the-art segmentation methods is shown qualitatively and quantitatively. Conclusion: A novel efficient and reliable clustering algorithm presented in this work, which is called FAFCM based on the hybridization of the firefly algorithm with fuzzy c-mean clustering algorithm. Automatically; the hybridized algorithm has the capability to cluster and segment MRI brain images.

  2. Advanced techniques in medical image segmentation of the liver

    OpenAIRE

    López Mir, Fernando

    2016-01-01

    [EN] Image segmentation is, along with multimodal and monomodal registration, the operation with the greatest applicability in medical image processing. There are many operations and filters, as much as applications and cases, where the segmentation of an organic tissue is the first step. The case of liver segmentation in radiological images is, after the brain, that on which the highest number of scientific publications can be found. This is due, on the one hand, to the need to continue inno...

  3. Improved Framework for Breast Cancer Detection using Hybrid Feature Extraction Technique and FFNN

    Directory of Open Access Journals (Sweden)

    Ibrahim Mohamed Jaber Alamin

    2016-10-01

    Full Text Available Breast Cancer early detection using terminologies of image processing is suffered from the less accuracy performance in different automated medical tools. To improve the accuracy, still there are many research studies going on different phases such as segmentation, feature extraction, detection, and classification. The proposed framework is consisting of four main steps such as image preprocessing, image segmentation, feature extraction and finally classification. This paper presenting the hybrid and automated image processing based framework for breast cancer detection. For image preprocessing, both Laplacian and average filtering approach is used for smoothing and noise reduction if any. These operations are performed on 256 x 256 sized gray scale image. Output of preprocessing phase is used at efficient segmentation phase. Algorithm is separately designed for preprocessing step with goal of improving the accuracy. Segmentation method contributed for segmentation is nothing but the improved version of region growing technique. Thus breast image segmentation is done by using proposed modified region growing technique. The modified region growing technique overcoming the limitations of orientation as well as intensity. The next step we proposed is feature extraction, for this framework we have proposed to use combination of different types of features such as texture features, gradient features, 2D-DWT features with higher order statistics (HOS. Such hybrid feature set helps to improve the detection accuracy. For last phase, we proposed to use efficient feed forward neural network (FFNN. The comparative study between existing 2D-DWT feature extraction and proposed HOS-2D-DWT based feature extraction methods is proposed.

  4. Unsupervised Neural Techniques Applied to MR Brain Image Segmentation

    Directory of Open Access Journals (Sweden)

    A. Ortiz

    2012-01-01

    Full Text Available The primary goal of brain image segmentation is to partition a given brain image into different regions representing anatomical structures. Magnetic resonance image (MRI segmentation is especially interesting, since accurate segmentation in white matter, grey matter and cerebrospinal fluid provides a way to identify many brain disorders such as dementia, schizophrenia or Alzheimer’s disease (AD. Then, image segmentation results in a very interesting tool for neuroanatomical analyses. In this paper we show three alternatives to MR brain image segmentation algorithms, with the Self-Organizing Map (SOM as the core of the algorithms. The procedures devised do not use any a priori knowledge about voxel class assignment, and results in fully-unsupervised methods for MRI segmentation, making it possible to automatically discover different tissue classes. Our algorithm has been tested using the images from the Internet Brain Image Repository (IBSR outperforming existing methods, providing values for the average overlap metric of 0.7 for the white and grey matter and 0.45 for the cerebrospinal fluid. Furthermore, it also provides good results for high-resolution MR images provided by the Nuclear Medicine Service of the “Virgen de las Nieves” Hospital (Granada, Spain.

  5. Improvements in analysis techniques for segmented mirror arrays

    Science.gov (United States)

    Michels, Gregory J.; Genberg, Victor L.; Bisson, Gary R.

    2016-08-01

    The employment of actively controlled segmented mirror architectures has become increasingly common in the development of current astronomical telescopes. Optomechanical analysis of such hardware presents unique issues compared to that of monolithic mirror designs. The work presented here is a review of current capabilities and improvements in the methodology of the analysis of mechanically induced surface deformation of such systems. The recent improvements include capability to differentiate surface deformation at the array and segment level. This differentiation allowing surface deformation analysis at each individual segment level offers useful insight into the mechanical behavior of the segments that is unavailable by analysis solely at the parent array level. In addition, capability to characterize the full displacement vector deformation of collections of points allows analysis of mechanical disturbance predictions of assembly interfaces relative to other assembly interfaces. This capability, called racking analysis, allows engineers to develop designs for segment-to-segment phasing performance in assembly integration, 0g release, and thermal stability of operation. The performance predicted by racking has the advantage of being comparable to the measurements used in assembly of hardware. Approaches to all of the above issues are presented and demonstrated by example with SigFit, a commercially available tool integrating mechanical analysis with optical analysis.

  6. A Hybrid Approach for Improving Image Segmentation: Application to Phenotyping of Wheat Leaves.

    Science.gov (United States)

    Chopin, Joshua; Laga, Hamid; Miklavcic, Stanley J

    2016-01-01

    In this article we propose a novel tool that takes an initial segmented image and returns a more accurate segmentation that accurately captures sharp features such as leaf tips, twists and axils. Our algorithm utilizes basic a-priori information about the shape of plant leaves and local image orientations to fit active contour models to important plant features that have been missed during the initial segmentation. We compare the performance of our approach with three state-of-the-art segmentation techniques, using three error metrics. The results show that leaf tips are detected with roughly one half of the original error, segmentation accuracy is almost always improved and more than half of the leaf breakages are corrected.

  7. A Hybrid Approach for Segmentation and Tracking of Myxococcus Xanthus Swarms.

    Science.gov (United States)

    Chen, Jianxu; Alber, Mark S; Chen, Danny Z

    2016-09-01

    Cell segmentation and motion tracking in time-lapse images are fundamental problems in computer vision, and are also crucial for various biomedical studies. Myxococcus xanthus is a type of rod-like cells with highly coordinated motion. The segmentation and tracking of M. xanthus are challenging, because cells may touch tightly and form dense swarms that are difficult to identify individually in an accurate manner. The known cell tracking approaches mainly fall into two frameworks, detection association and model evolution, each having its own advantages and disadvantages. In this paper, we propose a new hybrid framework combining these two frameworks into one and leveraging their complementary advantages. Also, we propose an active contour model based on the Ribbon Snake, which is seamlessly integrated with our hybrid framework. Evaluated by 10 different datasets, our approach achieves considerable improvement over the state-of-the-art cell tracking algorithms on identifying complete cell trajectories, and higher segmentation accuracy than performing segmentation in individual 2D images.

  8. Ultra Wide Band localization and tracking hybrid technique using VRTs

    Directory of Open Access Journals (Sweden)

    Mohd Shamian Zianal

    2012-12-01

    Full Text Available This research presents hybrid radar tracking technique consisting of Time Of Arrival (TOA and Received Signal Strength (RSS techniques. This hybrid design increases efficiency, accuracy and sensitivity of radar system. The radar used in this research is multistatic radar with one transmitter and three receivers. One common drawback in RSS and TOA techniques is high level synchronization in transmitter and receivers. The hybrid design also suffers from transmitter-receiver synchronization. To overcome TX-RX synchronization problem Virtual Reference Tags (VRTs are used. These tags are virtually mapped over the surveillance area giving radar design different reference points from which it can accurately locate intruder and monitor its movements. Also four cases of different

  9. Comparative study of retinal vessel segmentation based on global thresholding techniques.

    Science.gov (United States)

    Mapayi, Temitope; Viriri, Serestina; Tapamo, Jules-Raymond

    2015-01-01

    Due to noise from uneven contrast and illumination during acquisition process of retinal fundus images, the use of efficient preprocessing techniques is highly desirable to produce good retinal vessel segmentation results. This paper develops and compares the performance of different vessel segmentation techniques based on global thresholding using phase congruency and contrast limited adaptive histogram equalization (CLAHE) for the preprocessing of the retinal images. The results obtained show that the combination of preprocessing technique, global thresholding, and postprocessing techniques must be carefully chosen to achieve a good segmentation performance.

  10. Comparative Study of Retinal Vessel Segmentation Based on Global Thresholding Techniques

    Directory of Open Access Journals (Sweden)

    Temitope Mapayi

    2015-01-01

    Full Text Available Due to noise from uneven contrast and illumination during acquisition process of retinal fundus images, the use of efficient preprocessing techniques is highly desirable to produce good retinal vessel segmentation results. This paper develops and compares the performance of different vessel segmentation techniques based on global thresholding using phase congruency and contrast limited adaptive histogram equalization (CLAHE for the preprocessing of the retinal images. The results obtained show that the combination of preprocessing technique, global thresholding, and postprocessing techniques must be carefully chosen to achieve a good segmentation performance.

  11. Target segmentation in IR imagery using a wavelet-based technique

    Science.gov (United States)

    Sadjadi, Firooz A.

    1995-10-01

    Segmentation of ground based targets embedded in clutter obtained by airborne Infrared (IR) imaging sensors is one of the challenging problems in automatic target recognition. In this paper a new texture based segmentation technique is presented that uses the statistics of 2D wavelet decomposition components of the local sections of the image. A measure of statistical similarity is then used to segment the image and separate the target from the background. This technique is applied on a set of real sequential IR imagery and has shown to produce a high degree of segmentation accuracy across varying ranges.

  12. Thinning and line segmentation by line-following techniques

    Science.gov (United States)

    Larmagnac, Jean-Pierre

    1998-04-01

    A method for segmentation of elongated shapes is presented, including two stages: (1) Thinning of elongated shapes into chain coded lines. (2) Extraction of the main features. Thinning process: a square perimeter is developed around each current pixel, initially at level 255, belonging to a line being extracted. THe size of the square is progressively increased until one or more stick(s), frames by background pixels, appear(s) on the perimeter. From the beginning and the final indices of each stick we deduce the Freeman code leading to the following pixel on the line. Generally, two sticks are present on the square perimeter. One corresponds to the backward direction. To discard the non valid stick, each new detected pixel is marked by lowering its value by one shift right. In presence of a fork, or crossing point, there are more than one valid stick: The closest direction to the previous one is chosen; the current pixel is marked and stored in a list of branching points, for later processing. Filtering and segmentation: median filtering of extended codes, obtained from the corrected sums of 4 consecutive Freeman's codes allows to eliminate much of the quantization noise, without altering significant direction changes, and to segment the line into straight segments, arcs and corners.

  13. Comparison of thyroid segmentation techniques for 3D ultrasound

    Science.gov (United States)

    Wunderling, T.; Golla, B.; Poudel, P.; Arens, C.; Friebe, M.; Hansen, C.

    2017-02-01

    The segmentation of the thyroid in ultrasound images is a field of active research. The thyroid is a gland of the endocrine system and regulates several body functions. Measuring the volume of the thyroid is regular practice of diagnosing pathological changes. In this work, we compare three approaches for semi-automatic thyroid segmentation in freehand-tracked three-dimensional ultrasound images. The approaches are based on level set, graph cut and feature classification. For validation, sixteen 3D ultrasound records were created with ground truth segmentations, which we make publicly available. The properties analyzed are the Dice coefficient when compared against the ground truth reference and the effort of required interaction. Our results show that in terms of Dice coefficient, all algorithms perform similarly. For interaction, however, each algorithm has advantages over the other. The graph cut-based approach gives the practitioner direct influence on the final segmentation. Level set and feature classifier require less interaction, but offer less control over the result. All three compared methods show promising results for future work and provide several possible extensions.

  14. A hybrid localization technique for patient tracking.

    Science.gov (United States)

    Rodionov, Denis; Kolev, George; Bushminkin, Kirill

    2013-01-01

    Nowadays numerous technologies are employed for tracking patients and assets in hospitals or nursing homes. Each of them has advantages and drawbacks. For example, WiFi localization has relatively good accuracy but cannot be used in case of power outage or in the areas with poor WiFi coverage. Magnetometer positioning or cellular network does not have such problems but they are not as accurate as localization with WiFi. This paper describes technique that simultaneously employs different localization technologies for enhancing stability and average accuracy of localization. The proposed algorithm is based on fingerprinting method paired with data fusion and prediction algorithms for estimating the object location. The core idea of the algorithm is technology fusion using error estimation methods. For testing accuracy and performance of the algorithm testing simulation environment has been implemented. Significant accuracy improvement was showed in practical scenarios.

  15. Adaptive Thresholding Technique for Retinal Vessel Segmentation Based on GLCM-Energy Information

    OpenAIRE

    Temitope Mapayi; Serestina Viriri; Jules-Raymond Tapamo

    2015-01-01

    Although retinal vessel segmentation has been extensively researched, a robust and time efficient segmentation method is highly needed. This paper presents a local adaptive thresholding technique based on gray level cooccurrence matrix- (GLCM-) energy information for retinal vessel segmentation. Different thresholds were computed using GLCM-energy information. An experimental evaluation on DRIVE database using the grayscale intensity and Green Channel of the retinal image demo...

  16. New techniques for emulsion analysis in a hybrid experiment

    Energy Technology Data Exchange (ETDEWEB)

    Kodama, K. (Aichi University of Education, Kariya 448 (Japan)); Ushida, N. (Aichi University of Education, Kariya 448 (Japan)); Mokhtarani, A. (University of California (Davis), Davis, CA 95616 (United States)); Paolone, V.S. (University of California (Davis), Davis, CA 95616 (United States)); Volk, J.T. (University of California (Davis), Davis, CA 95616 (United States)); Wilcox, J.O. (University of California (Davis), Davis, CA 95616 (United States)); Yager, P.M. (University of California (Davis), Davis, CA 95616 (United States)); Edelstein, R.M. (Carnegie-Mellon University, Pittsburgh, PA 15213 (United States)); Freyberger, A.P. (Carnegie-Mellon University, Pittsburgh, PA 15213 (United States)); Gibaut, D.B. (Carnegie-Mellon University, Pittsburgh, PA 15213 (United States)); Lipton, R.J. (Carnegie-Mellon University, Pittsburgh, PA 15213 (United States)); Nichols, W.R. (Carnegie-Mellon University, Pittsburgh, PA 15213 (United States)); Potter, D.M. (Carnegie-Mellon Univers

    1994-08-01

    A new method, called graphic scanning, was developed by the Nagoya University Group for emulsion analysis in a hybrid experiment. This method enhances both speed and reliability of emulsion analysis. Details of the application of this technique to the analysis of Fermilab experiment E653 are described. ((orig.))

  17. A Hybridized Centroid Technique for 3D Molodensky-Badekas ...

    African Journals Online (AJOL)

    Richannan

    two new hybrid centroid techniques known as the harmonic-quadratic mean and arithmetic- ... was subsequently involved in triangulation nets with other trigonometric ..... The functional relation that is used to compute the TLS solution is given by ..... mathematical models is an approximation of reality, hence it is worth noting ...

  18. Manufacturing technique and performance of functionally graded concrete segment in shield tunnel

    Institute of Scientific and Technical Information of China (English)

    Baoguo MA; Dinghua ZOU; Li XU

    2009-01-01

    The quality of segment is very important to theservice life of shield tunnel. Concerning the complex engineering environment of the Wuhan Yangtze River Shield Tunnel, the principle of functionally graded materials was introduced to design and produce the functionally graded concrete segment (FGCS). Its key manufacturing technique was proposed and its perfor-mance was tested.

  19. A hybrid method for airway segmentation and automated measurement of bronchial wall thickness on CT.

    Science.gov (United States)

    Xu, Ziyue; Bagci, Ulas; Foster, Brent; Mansoor, Awais; Udupa, Jayaram K; Mollura, Daniel J

    2015-08-01

    Inflammatory and infectious lung diseases commonly involve bronchial airway structures and morphology, and these abnormalities are often analyzed non-invasively through high resolution computed tomography (CT) scans. Assessing airway wall surfaces and the lumen are of great importance for diagnosing pulmonary diseases. However, obtaining high accuracy from a complete 3-D airway tree structure can be quite challenging. The airway tree structure has spiculated shapes with multiple branches and bifurcation points as opposed to solid single organ or tumor segmentation tasks in other applications, hence, it is complex for manual segmentation as compared with other tasks. For computerized methods, a fundamental challenge in airway tree segmentation is the highly variable intensity levels in the lumen area, which often causes a segmentation method to leak into adjacent lung parenchyma through blurred airway walls or soft boundaries. Moreover, outer wall definition can be difficult due to similar intensities of the airway walls and nearby structures such as vessels. In this paper, we propose a computational framework to accurately quantify airways through (i) a novel hybrid approach for precise segmentation of the lumen, and (ii) two novel methods (a spatially constrained Markov random walk method (pseudo 3-D) and a relative fuzzy connectedness method (3-D)) to estimate the airway wall thickness. We evaluate the performance of our proposed methods in comparison with mostly used algorithms using human chest CT images. Our results demonstrate that, on publicly available data sets and using standard evaluation criteria, the proposed airway segmentation method is accurate and efficient as compared with the state-of-the-art methods, and the airway wall estimation algorithms identified the inner and outer airway surfaces more accurately than the most widely applied methods, namely full width at half maximum and phase congruency.

  20. A new iterative triclass thresholding technique in image segmentation.

    Science.gov (United States)

    Cai, Hongmin; Yang, Zhong; Cao, Xinhua; Xia, Weiming; Xu, Xiaoyin

    2014-03-01

    We present a new method in image segmentation that is based on Otsu's method but iteratively searches for subregions of the image for segmentation, instead of treating the full image as a whole region for processing. The iterative method starts with Otsu's threshold and computes the mean values of the two classes as separated by the threshold. Based on the Otsu's threshold and the two mean values, the method separates the image into three classes instead of two as the standard Otsu's method does. The first two classes are determined as the foreground and background and they will not be processed further. The third class is denoted as a to-be-determined (TBD) region that is processed at next iteration. At the succeeding iteration, Otsu's method is applied on the TBD region to calculate a new threshold and two class means and the TBD region is again separated into three classes, namely, foreground, background, and a new TBD region, which by definition is smaller than the previous TBD regions. Then, the new TBD region is processed in the similar manner. The process stops when the Otsu's thresholds calculated between two iterations is less than a preset threshold. Then, all the intermediate foreground and background regions are, respectively, combined to create the final segmentation result. Tests on synthetic and real images showed that the new iterative method can achieve better performance than the standard Otsu's method in many challenging cases, such as identifying weak objects and revealing fine structures of complex objects while the added computational cost is minimal.

  1. A novel hybrid surface micromachined segmented mirror for large aperture laser applications

    Institute of Scientific and Technical Information of China (English)

    Jie Li; Haiqing Chen; Hongbin Yu

    2006-01-01

    @@ A novel hybrid surface micromachined segmented mirror array is described. This device is capable of scaling to large apertures for correcting time-varying aberrations in laser applications. Each mirror is composed of bottom electrode, support part, and mirror plate, in which a T-shaped beam structure is used to support the mirror plate. It can provide mirror with vertical movement and rotation around two horizontal axes. The test results show that the maximum deflection along the vertical direction of the mirror plate is 2μm, while the rotation angles around x and y axes are ±2.3° and ±1.45°, respectively.

  2. Bonding techniques for hybrid active pixel sensors (HAPS)

    Science.gov (United States)

    Bigas, M.; Cabruja, E.; Lozano, M.

    2007-05-01

    A hybrid active pixel sensor (HAPS) consists of an array of sensing elements which is connected to an electronic read-out unit. The most used way to connect these two different devices is bump bonding. This interconnection technique is very suitable for these systems because it allows a very fine pitch and a high number of I/Os. However, there are other interconnection techniques available such as direct bonding. This paper, as a continuation of a review [M. Lozano, E. Cabruja, A. Collado, J. Santander, M. Ullan, Nucl. Instr. and Meth. A 473 (1-2) (2001) 95-101] published in 2001, presents an update of the different advanced bonding techniques available for manufacturing a hybrid active pixel detector.

  3. Measuring glioma volumes: A comparison of linear measurement based formulae with the manual image segmentation technique

    Directory of Open Access Journals (Sweden)

    Sanjeev A Sreenivasan

    2016-01-01

    Conclusions: Manual region of interest-based image segmentation is the standard technique for measuring glioma volumes. For routine clinical use, the simple formula v = abc/2 (or the formula for volume of an ellipsoid could be used as alternatives.

  4. Atlas-based segmentation technique incorporating inter-observer delineation uncertainty for whole breast

    Science.gov (United States)

    Bell, L. R.; Dowling, J. A.; Pogson, E. M.; Metcalfe, P.; Holloway, L.

    2017-01-01

    Accurate, efficient auto-segmentation methods are essential for the clinical efficacy of adaptive radiotherapy delivered with highly conformal techniques. Current atlas based auto-segmentation techniques are adequate in this respect, however fail to account for inter-observer variation. An atlas-based segmentation method that incorporates inter-observer variation is proposed. This method is validated for a whole breast radiotherapy cohort containing 28 CT datasets with CTVs delineated by eight observers. To optimise atlas accuracy, the cohort was divided into categories by mean body mass index and laterality, with atlas’ generated for each in a leave-one-out approach. Observer CTVs were merged and thresholded to generate an auto-segmentation model representing both inter-observer and inter-patient differences. For each category, the atlas was registered to the left-out dataset to enable propagation of the auto-segmentation from atlas space. Auto-segmentation time was recorded. The segmentation was compared to the gold-standard contour using the dice similarity coefficient (DSC) and mean absolute surface distance (MASD). Comparison with the smallest and largest CTV was also made. This atlas-based auto-segmentation method incorporating inter-observer variation was shown to be efficient (0.7, MASD <9.3mm) between the auto-segmented contours and CTV volumes.

  5. Wind Speed Forecasting Using Hybrid Wavelet Transform—ARMA Techniques

    OpenAIRE

    Diksha Kaur; Tek Tjing Lie; Nirmal K. C. Nair; Brice Vallès

    2015-01-01

    The objective of this paper is to develop a novel wind speed forecasting technique, which produces more accurate prediction. The Wavelet Transform (WT) along with the Auto Regressive Moving Average (ARMA) is chosen to form a hybrid whose combination is expected to give minimum Mean Absolute Prediction Error (MAPE). A simulation study has been conducted by comparing the forecasting results using the Wavelet-ARMA with the ARMA and Artificial Neural Network (ANN)-Ensemble Kalman Filter (EnKF) hy...

  6. Magnetic resonance imaging segmentation techniques using batch-type learning vector quantization algorithms.

    Science.gov (United States)

    Yang, Miin-Shen; Lin, Karen Chia-Ren; Liu, Hsiu-Chih; Lirng, Jiing-Feng

    2007-02-01

    In this article, we propose batch-type learning vector quantization (LVQ) segmentation techniques for the magnetic resonance (MR) images. Magnetic resonance imaging (MRI) segmentation is an important technique to differentiate abnormal and normal tissues in MR image data. The proposed LVQ segmentation techniques are compared with the generalized Kohonen's competitive learning (GKCL) methods, which were proposed by Lin et al. [Magn Reson Imaging 21 (2003) 863-870]. Three MRI data sets of real cases are used in this article. The first case is from a 2-year-old girl who was diagnosed with retinoblastoma in her left eye. The second case is from a 55-year-old woman who developed complete left side oculomotor palsy immediately after a motor vehicle accident. The third case is from an 84-year-old man who was diagnosed with Alzheimer disease (AD). Our comparisons are based on sensitivity of algorithm parameters, the quality of MRI segmentation with the contrast-to-noise ratio and the accuracy of the region of interest tissue. Overall, the segmentation results from batch-type LVQ algorithms present good accuracy and quality of the segmentation images, and also flexibility of algorithm parameters in all the comparison consequences. The results support that the proposed batch-type LVQ algorithms are better than the previous GKCL algorithms. Specifically, the proposed fuzzy-soft LVQ algorithm works well in segmenting AD MRI data set to accurately measure the hippocampus volume in AD MR images.

  7. Toward accurate tooth segmentation from computed tomography images using a hybrid level set model

    Energy Technology Data Exchange (ETDEWEB)

    Gan, Yangzhou; Zhao, Qunfei [Department of Automation, Shanghai Jiao Tong University, and Key Laboratory of System Control and Information Processing, Ministry of Education of China, Shanghai 200240 (China); Xia, Zeyang, E-mail: zy.xia@siat.ac.cn, E-mail: jing.xiong@siat.ac.cn; Hu, Ying [Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, and The Chinese University of Hong Kong, Shenzhen 518055 (China); Xiong, Jing, E-mail: zy.xia@siat.ac.cn, E-mail: jing.xiong@siat.ac.cn [Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 510855 (China); Zhang, Jianwei [TAMS, Department of Informatics, University of Hamburg, Hamburg 22527 (Germany)

    2015-01-15

    Purpose: A three-dimensional (3D) model of the teeth provides important information for orthodontic diagnosis and treatment planning. Tooth segmentation is an essential step in generating the 3D digital model from computed tomography (CT) images. The aim of this study is to develop an accurate and efficient tooth segmentation method from CT images. Methods: The 3D dental CT volumetric images are segmented slice by slice in a two-dimensional (2D) transverse plane. The 2D segmentation is composed of a manual initialization step and an automatic slice by slice segmentation step. In the manual initialization step, the user manually picks a starting slice and selects a seed point for each tooth in this slice. In the automatic slice segmentation step, a developed hybrid level set model is applied to segment tooth contours from each slice. Tooth contour propagation strategy is employed to initialize the level set function automatically. Cone beam CT (CBCT) images of two subjects were used to tune the parameters. Images of 16 additional subjects were used to validate the performance of the method. Volume overlap metrics and surface distance metrics were adopted to assess the segmentation accuracy quantitatively. The volume overlap metrics were volume difference (VD, mm{sup 3}) and Dice similarity coefficient (DSC, %). The surface distance metrics were average symmetric surface distance (ASSD, mm), RMS (root mean square) symmetric surface distance (RMSSSD, mm), and maximum symmetric surface distance (MSSD, mm). Computation time was recorded to assess the efficiency. The performance of the proposed method has been compared with two state-of-the-art methods. Results: For the tested CBCT images, the VD, DSC, ASSD, RMSSSD, and MSSD for the incisor were 38.16 ± 12.94 mm{sup 3}, 88.82 ± 2.14%, 0.29 ± 0.03 mm, 0.32 ± 0.08 mm, and 1.25 ± 0.58 mm, respectively; the VD, DSC, ASSD, RMSSSD, and MSSD for the canine were 49.12 ± 9.33 mm{sup 3}, 91.57 ± 0.82%, 0.27 ± 0.02 mm, 0

  8. A hybrid and adaptive segmentation method using color and texture information

    Science.gov (United States)

    Meurie, C.; Ruichek, Y.; Cohen, A.; Marais, J.

    2010-01-01

    This paper presents a new image segmentation method based on the combination of texture and color informations. The method first computes the morphological color and texture gradients. The color gradient is analyzed taking into account the different color spaces. The texture gradient is computed using the luminance component of the HSL color space. The texture gradient procedure is achieved using a morphological filter and a granulometric and local energy analysis. To overcome the limitations of a linear/barycentric combination, the two morphological gradients are then mixed using a gradient component fusion strategy (to fuse the three components of the color gradient and the unique component of the texture gradient) and an adaptive technique to choose the weighting coefficients. The segmentation process is finally performed by applying the watershed technique using different type of germ images. The segmentation method is evaluated in different object classification applications using the k-means algorithm. The obtained results are compared with other known segmentation methods. The evaluation analysis shows that the proposed method gives better results, especially with hard image acquisition conditions.

  9. Early Oscillation Detection Technique for Hybrid DC/DC Converters

    Science.gov (United States)

    Wang, Bright L.

    2011-01-01

    Oscillation or instability is a situation that must be avoided for reliable hybrid DC/DC converters. A real-time electronics measurement technique was developed to detect catastrophic oscillations at early stages for hybrid DC/DC converters. It is capable of identifying low-level oscillation and determining the degree of the oscillation at a unique frequency for every individual model of the converters without disturbing their normal operations. This technique is specially developed for space-used hybrid DC/DC converters, but it is also suitable for most of commercial and military switching-mode power supplies. This is a weak-electronic-signal detection technique to detect hybrid DC/DC converter oscillation presented as a specific noise signal at power input pins. It is based on principles of feedback control loop oscillation and RF signal modulations, and is realized by using signal power spectral analysis. On the power spectrum, a channel power amplitude at characteristic frequency (CPcf) and a channel power amplitude at switching frequency (CPsw) are chosen as oscillation level indicators. If the converter is stable, the CPcf is a very small pulse and the CPsw is a larger, clear, single pulse. At early stage of oscillation, the CPcf increases to a certain level and the CPsw shows a small pair of sideband pulses around it. If the converter oscillates, the CPcf reaches to a higher level and the CPsw shows more high-level sideband pulses. A comprehensive stability index (CSI) is adopted as a quantitative measure to accurately assign a degree of stability to a specific DC/DC converter. The CSI is a ratio of normal and abnormal power spectral density, and can be calculated using specified and measured CPcf and CPsw data. The novel and unique feature of this technique is the use of power channel amplitudes at characteristic frequency and switching frequency to evaluate stability and identify oscillations at an early stage without interfering with a DC/DC converter s

  10. A Review On Segmentation Based Image Compression Techniques

    Directory of Open Access Journals (Sweden)

    S.Thayammal

    2013-11-01

    Full Text Available Abstract -The storage and transmission of imagery become more challenging task in the current scenario of multimedia applications. Hence, an efficient compression scheme is highly essential for imagery, which reduces the requirement of storage medium and transmission bandwidth. Not only improvement in performance and also the compression techniques must converge quickly in order to apply them for real time applications. There are various algorithms have been done in image compression, but everyone has its own pros and cons. Here, an extensive analysis between existing methods is performed. Also, the use of existing works is highlighted, for developing the novel techniques which face the challenging task of image storage and transmission in multimedia applications.

  11. Adaptive thresholding technique for retinal vessel segmentation based on GLCM-energy information.

    Science.gov (United States)

    Mapayi, Temitope; Viriri, Serestina; Tapamo, Jules-Raymond

    2015-01-01

    Although retinal vessel segmentation has been extensively researched, a robust and time efficient segmentation method is highly needed. This paper presents a local adaptive thresholding technique based on gray level cooccurrence matrix- (GLCM-) energy information for retinal vessel segmentation. Different thresholds were computed using GLCM-energy information. An experimental evaluation on DRIVE database using the grayscale intensity and Green Channel of the retinal image demonstrates the high performance of the proposed local adaptive thresholding technique. The maximum average accuracy rates of 0.9511 and 0.9510 with maximum average sensitivity rates of 0.7650 and 0.7641 were achieved on DRIVE and STARE databases, respectively. When compared to the widely previously used techniques on the databases, the proposed adaptive thresholding technique is time efficient with a higher average sensitivity and average accuracy rates in the same range of very good specificity.

  12. Evaluation of hippocampal volume based on MRI applying manual and automatic segmentation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Doring, Thomas M.; Gasparetto, Emerson L. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil); Kubo, Tadeu T.A.; Domingues, Romeu C. [Clinica de Diagnostico por Imagem (CDPI), Rio de Janeiro, RJ (Brazil)

    2010-03-15

    Various segmentation techniques using MR sequences, including manual and automatic protocols, have been developed to optimize the determination of the hippocampal volume. For clinical application, automated methods with high reproducibility and accuracy potentially may be more efficient than manual volumetry. This study aims to compare the hippocampal volumes obtained from manual and automatic segmentation methods (FreeSurfer and FSL). The automatic segmentation method FreeSurfer showed high correlation. Comparing the absolute hippocampal volumes, there is an overestimation by the automated methods. Applying a correction factor to the automatic method, it may be an alternative for the estimation of the absolute hippocampal volume. (author)

  13. A REVIEW ON SEGMENTATION TECHNIQUES OF LINES, WORDS AND CHARACTERS ON GUJARATI HANDWRITTEN DOCUMENT USING OCR

    OpenAIRE

    Nilam Mistry*, Sameer Vashi, Vidhi Patel, Kunal Shah, Denish Rixawapla, Foram Rakholiya, Rakesh Savant

    2016-01-01

    OCR is technique to convert the handwritten or printed document into the digital format by scanning it which can be understandable by a computer. OCR is important and challenging task in many computer vision applications. Segmentation is generally the first stage in any attempt to analyse or interpret an image automatically.  Segmentation is separate the document into lines, lines to words and words to characters which has been one of the major laboriousness in handwritten text recogniti...

  14. An alignment and integration technique for mirror segment pairs on the Constellation-X telescope

    Science.gov (United States)

    Hadjimichael, Theo; Owens, Scott; Lehan, John; Olsen, Larry; Saha, Timo; Wallace, Tom; Zhang, Will

    2007-09-01

    We present the concepts behind the current alignment and integration technique for a Constellation-X primary-secondary mirror segment pair prior to an x-ray beam line test. We examine the effects of a passive mount on thin glass x-ray mirror segments, and the issues of mount shape and environment on alignment. We also investigate how bonding and transfer to a permanent housing affects the quality of the final image.

  15. Patch forest: a hybrid framework of random forest and patch-based segmentation

    Science.gov (United States)

    Xie, Zhongliu; Gillies, Duncan

    2016-03-01

    The development of an accurate, robust and fast segmentation algorithm has long been a research focus in medical computer vision. State-of-the-art practices often involve non-rigidly registering a target image with a set of training atlases for label propagation over the target space to perform segmentation, a.k.a. multi-atlas label propagation (MALP). In recent years, the patch-based segmentation (PBS) framework has gained wide attention due to its advantage of relaxing the strict voxel-to-voxel correspondence to a series of pair-wise patch comparisons for contextual pattern matching. Despite a high accuracy reported in many scenarios, computational efficiency has consistently been a major obstacle for both approaches. Inspired by recent work on random forest, in this paper we propose a patch forest approach, which by equipping the conventional PBS with a fast patch search engine, is able to boost segmentation speed significantly while retaining an equal level of accuracy. In addition, a fast forest training mechanism is also proposed, with the use of a dynamic grid framework to efficiently approximate data compactness computation and a 3D integral image technique for fast box feature retrieval.

  16. A Hybrid Segmentation Model based on Watershed and Gradient Vector Flow for the Detection of Brain Tumor

    Directory of Open Access Journals (Sweden)

    D. Jayadevappa

    2009-09-01

    Full Text Available Medical Image segmentation deals with segmentation of tumor in CT and MR images for improved quality in medical diagnosis. Geometric Vector Flow (GVF enhances the concave object extraction capability. However, it suffers from high computational requirement andsensitiveness to noise. This paper intends to combine watershed algorithm with GVF snake model to reduce the computational complexity, to improve the insensitiveness to noise, and capture range. Specifically, the image will be segmented firstly through watershed algorithm and then the edges produced will be the initial contour of GVF model. This enhances the tumor boundaries and tuning the regulating parameters of the GVF snake mode by couplingthe smoothness of the edge map obtained due to watershed algorithm. The proposed method is compared with recent hybrid segmentation algorithm based on watershed and balloon snake. Superiority of the proposed work is observed in terms of capture range, concave objectextraction capability, sensitivity to noise, computational complexity, and segmentation accuracy.

  17. Segmentation techniques evaluation based on a single compact breast mass classification scheme

    Science.gov (United States)

    Matheus, Bruno R. N.; Marcomini, Karem D.; Schiabel, Homero

    2016-03-01

    In this work some segmentation techniques are evaluated by using a simple centroid-based classification system regarding breast mass delineation in digital mammography images. The aim is to determine the best one for future CADx developments. Six techniques were tested: Otsu, SOM, EICAMM, Fuzzy C-Means, K-Means and Level-Set. All of them were applied to segment 317 mammography images from DDSM database. A single compact set of attributes was extracted and two centroids were defined, one for malignant and another for benign cases. The final classification was based on proximity with a given centroid and the best results were presented by the Level-Set technique with a 68.1% of Accuracy, which indicates this method as the most promising for breast masses segmentation aiming a more precise interpretation in schemes CADx.

  18. Hybrid Artificial Root Foraging Optimizer Based Multilevel Threshold for Image Segmentation

    Science.gov (United States)

    Liu, Yang; Liu, Junfei

    2016-01-01

    This paper proposes a new plant-inspired optimization algorithm for multilevel threshold image segmentation, namely, hybrid artificial root foraging optimizer (HARFO), which essentially mimics the iterative root foraging behaviors. In this algorithm the new growth operators of branching, regrowing, and shrinkage are initially designed to optimize continuous space search by combining root-to-root communication and coevolution mechanism. With the auxin-regulated scheme, various root growth operators are guided systematically. With root-to-root communication, individuals exchange information in different efficient topologies, which essentially improve the exploration ability. With coevolution mechanism, the hierarchical spatial population driven by evolutionary pressure of multiple subpopulations is structured, which ensure that the diversity of root population is well maintained. The comparative results on a suit of benchmarks show the superiority of the proposed algorithm. Finally, the proposed HARFO algorithm is applied to handle the complex image segmentation problem based on multilevel threshold. Computational results of this approach on a set of tested images show the outperformance of the proposed algorithm in terms of optimization accuracy computation efficiency. PMID:27725826

  19. Resonant frequency calculations using a hybrid perturbation-Galerkin technique

    Science.gov (United States)

    Geer, James F.; Andersen, Carl M.

    1991-01-01

    A two-step hybrid perturbation Galerkin technique is applied to the problem of determining the resonant frequencies of one or several degrees of freedom nonlinear systems involving a parameter. In one step, the Lindstedt-Poincare method is used to determine perturbation solutions which are formally valid about one or more special values of the parameter (e.g., for large or small values of the parameter). In step two, a subset of the perturbation coordinate functions determined in step one is used in Galerkin type approximation. The technique is illustrated for several one degree of freedom systems, including the Duffing and van der Pol oscillators, as well as for the compound pendulum. For all of the examples considered, it is shown that the frequencies obtained by the hybrid technique using only a few terms from the perturbation solutions are significantly more accurate than the perturbation results on which they are based, and they compare very well with frequencies obtained by purely numerical methods.

  20. Hybrid Technique of Lamellar Keratoplasty (DMEK-S

    Directory of Open Access Journals (Sweden)

    Pavel Studeny

    2013-01-01

    Full Text Available Purpose: To evaluate the outcomes of the hybrid technique of posterior lamellar keratoplasty (DMEK-S. Materials and Methods: 71 eyes of 55 patients enrolled in a single-center study underwent posterior lamellar keratoplasty with a hybrid lamella DMEK-S implanted using a solution implantation technique, owing to endothelial dysfunction. The outcome measures studied were visual acuity and endothelial cell density. Results: The rate of endothelial cell loss caused by surgery was 43.8%. During followups, we observed the stabilization of postoperative findings, or at minimum a very low rate of corneal endothelial cell loss. The UCDVA and BCDVA dramatically improved postoperatively. The rebubbling rate in our group of patients was 61.9%. We replaced the lamella due to its failure or malfunction in 17 patients (23.9%. Conclusion: In summary, DMEK-S combines the advantages of DSEK/DSAEK and DMEK. The central zone of bare Descemet’s membrane and endothelium allows for very good visual outcomes, and the peripheral rim allows for better manipulation of the lamella during implantation. It is an effective method of treating the endothelial dysfunction of various etiologies, but the high complication rate needs to be addressed before widespread implementation of the technique in the future.

  1. Colour image segmentation using unsupervised clustering technique for acute leukemia images

    Science.gov (United States)

    Halim, N. H. Abd; Mashor, M. Y.; Nasir, A. S. Abdul; Mustafa, N.; Hassan, R.

    2015-05-01

    Colour image segmentation has becoming more popular for computer vision due to its important process in most medical analysis tasks. This paper proposes comparison between different colour components of RGB(red, green, blue) and HSI (hue, saturation, intensity) colour models that will be used in order to segment the acute leukemia images. First, partial contrast stretching is applied on leukemia images to increase the visual aspect of the blast cells. Then, an unsupervised moving k-means clustering algorithm is applied on the various colour components of RGB and HSI colour models for the purpose of segmentation of blast cells from the red blood cells and background regions in leukemia image. Different colour components of RGB and HSI colour models have been analyzed in order to identify the colour component that can give the good segmentation performance. The segmented images are then processed using median filter and region growing technique to reduce noise and smooth the images. The results show that segmentation using saturation component of HSI colour model has proven to be the best in segmenting nucleus of the blast cells in acute leukemia image as compared to the other colour components of RGB and HSI colour models.

  2. STUDY OF IMAGE SEGMENTATION TECHNIQUES ON RETINAL IMAGES FOR HEALTH CARE MANAGEMENT WITH FAST COMPUTING

    Directory of Open Access Journals (Sweden)

    Srikanth Prabhu

    2012-02-01

    Full Text Available The role of segmentation in image processing is to separate foreground from background. In this process, the features become clearly visible when appropriate filters are applied on the image. In this paper emphasis has been laid on segmentation of biometric retinal images to filter out the vessels explicitly for evaluating the bifurcation points and features for diabetic retinopathy. Segmentation on images is performed by calculating ridges or morphology. Ridges are those areas in the images where there is sharp contrast in features. Morphology targets the features using structuring elements. Structuring elements are of different shapes like disk, line which is used for extracting features of those shapes. When segmentation was performed on retinal images problems were encountered during image pre-processing stage. Also edge detection techniques have been deployed to find out the contours of the retinal images. After the segmentation has been performed, it has been seen that artifacts of the retinal images have been minimal when ridge based segmentation technique was deployed. In the field of Health Care Management, image segmentation has an important role to play as it determines whether a person is normal or having any disease specially diabetes. During the process of segmentation, diseased features are classified as diseased one’s or artifacts. The problem comes when artifacts are classified as diseased ones. This results in misclassification which has been discussed in the analysis Section. We have achieved fast computing with better performance, in terms of speed for non-repeating features, when compared to repeating features.

  3. A hybrid sequential deposition fabrication technique for micro fuel cells

    Science.gov (United States)

    Stanley, Kevin G.; Czyzewska, Eva K.; Vanderhoek, Tom P. K.; Fan, Lilian L. Y.; Abel, Keith A.; Wu, Q. M. Jonathan; Parameswaran, M. Ash

    2005-10-01

    Micro fuel cell systems have elicited significant interest due to their promise for instantly rechargeable, longer duration and portable power. Most micro fuel cell systems are either built as miniaturized plate-and-frame or silicon-based microelectromechanical systems (MEMS). Plate-and-frame systems are difficult to fabricate smaller than 20 cm3. Existing micro fuel cell designs cannot meet the cost, scale and power requirements of some portable power markets. Traditional MEMS scaling advantages do not apply to fuel cells because the minimum area for the fuel cell is fixed by the catalyst area required for a given power output, and minimum volume set by mass transport limitations. We have developed a new hybrid technique that borrows from both micro and macro machining techniques to create fuel cells in the 1-20 cm3 range, suitable for cell phones, PDAs and smaller devices.

  4. An Adaptive Hybrid Multiprocessor technique for bioinformatics sequence alignment

    KAUST Repository

    Bonny, Talal

    2012-07-28

    Sequence alignment algorithms such as the Smith-Waterman algorithm are among the most important applications in the development of bioinformatics. Sequence alignment algorithms must process large amounts of data which may take a long time. Here, we introduce our Adaptive Hybrid Multiprocessor technique to accelerate the implementation of the Smith-Waterman algorithm. Our technique utilizes both the graphics processing unit (GPU) and the central processing unit (CPU). It adapts to the implementation according to the number of CPUs given as input by efficiently distributing the workload between the processing units. Using existing resources (GPU and CPU) in an efficient way is a novel approach. The peak performance achieved for the platforms GPU + CPU, GPU + 2CPUs, and GPU + 3CPUs is 10.4 GCUPS, 13.7 GCUPS, and 18.6 GCUPS, respectively (with the query length of 511 amino acid). © 2010 IEEE.

  5. The Efficacy of Lumbar Hybrid Stabilization Using the DIAM™ to Delay Adjacent Segment Degeneration: An Intervention Comparison Study With a Minimum Two-Year Follow-up.

    Science.gov (United States)

    Lee, Chang-Hyun; Hyun, Seung-Jae; Kim, Ki-Jeong; Jahng, Tae-Ahn; Yoon, Sang Hoon; Kim, Hyun-Jib

    2013-04-29

    BACKGROUND:: Although posterior lumbar interbody fusion (PLIF) has a successful fusion rate, the long-term outcome of PLIF is occasionally below expectations because of adjacent segment degeneration (ASD). OBJECTIVE:: To evaluate the ability of hybrid stabilization using DIAM(Device for Interspinous Assisted Motion) to delay ASD. METHODS:: An intervention comparison study of 75 patients (hybrid, 25; PLIF, 50) was performed. The indications for hybrid stabilization were facet joint degeneration, Pfirrmann grade II-III, and stenosis at the rostral adjacent segment. The PLIF group consisted of patients matched for age, gender, and fusion. The hybrid stabilization procedure included traditional PLIF and DIAM installation at a superior adjacent segment. The outcomes were analyzed using linear mixed model analysis. Conditional logistic regression was performed to calculate the odds ratio for the association of surgical methods. RESULTS:: The hybrid group (24%) revealed fewer ASDs than the PLIF group (48%). Among ASDs, spondylolisthesis occurred more frequently in the PLIF group than the hybrid group. Hybrid surgery was significantly associated with ASD; the odds ratio for hybrid surgery was 0.28 when compared to PLIF. Foraminal height of the PLIF group decreased more than the hybrid group (P=.01). Segmental mobility showed a greater increase in the PLIF group than the hybrid group (P=.04). However, the clinical outcomes did not show significant differences between the groups. CONCLUSION:: Hybrid stabilization using DIAM and pedicle screws can be used for patients with facet degeneration at adjacent segments but should be further investigated.

  6. A new anastomosis technique for intestinal diseases with proximal dilated segments

    Directory of Open Access Journals (Sweden)

    Metin Gündüz

    2016-01-01

    Full Text Available A number of techniques have been described for intestinal anastomosis. We describe a different, simple, and safe technique that can be used in patients with intestinal diseases, such as jejunoileal atresia and perforation that has proximal dilated segments. In this technique, an atraumatic bowel clamp was applied on the proximal dilated bowel at a 90° angle. In the narrow distal segment, we resected the bowel at a 0° angle and continued at a 30° angle from the antimesenteric side. Finally, a two-layer interrupted anastomosis was performed. We applied this technique to a 31-day-old patient who had a divided jejunostomy due to malrotation and perforation with a proximal dilated bowel. Neither anastomotic complications nor feeding and passage problems were seen postoperatively.

  7. The commercial use of segmentation and predictive modeling techniques for database marketing in the Netherlands

    NARCIS (Netherlands)

    Verhoef, PC; Spring, PN; Hoekstra, JC; Leeflang, PSH

    2003-01-01

    Although the application of segmentation and predictive modeling is an important topic in the database marketing (DBM) literature, no study has yet investigated the extent of adoption of these techniques. We present the results of a Dutch survey involving 228 database marketing companies. We find th

  8. The commercial use of segmentation and predictive modeling techniques for database marketing in the Netherlands

    NARCIS (Netherlands)

    Verhoef, PC; Spring, PN; Hoekstra, JC; Leeflang, PSH

    Although the application of segmentation and predictive modeling is an important topic in the database marketing (DBM) literature, no study has yet investigated the extent of adoption of these techniques. We present the results of a Dutch survey involving 228 database marketing companies. We find

  9. 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.

  10. A Proposed Hybrid Technique for Recognizing Arabic Characters

    Directory of Open Access Journals (Sweden)

    S F Bahgat

    2012-07-01

    Full Text Available Optical character recognition systems improve human-machine interaction and are urgently required for many governmental and commercial departments. A considerable progress in the recognition techniques of Latin and Chinese characters has been achieved. By contrast, Arabic Optical Character Recognition (AOCR is still lagging although the interest and research in this area is becoming more intensive than before. This is because the Arabic is a cursive language, written from right to left, each character has two to four different forms according to its position in the word, and most characters are associated with complementary parts above, below, or inside the character. The process of Arabic character recognition passes through several stages; the most serious and error-prone of which are segmentation, and feature extraction & classification. This research focuses on the feature extraction and classification stage, being as important as the segmentation stage. Features can be classified into two categories; Local features, which are usually geometric, and Global features, which are either topological or statistical. Four approaches related to the statistical category are to be investigated, namely: Moment Invariants, Gray Level Co-occurrence Matrix, Run Length Matrix, and Statistical Properties of Intensity Histogram. The paper aims at fusing the features of these methods to get the most representative feature vector that maximizes the recognition rate.

  11. Comparison of atlas-based techniques for whole-body bone segmentation

    DEFF Research Database (Denmark)

    Arabi, Hossein; Zaidi, Habib

    2017-01-01

    square distance (MSD) as image similarity measures for calculating the weighting factors, along with other atlas-dependent algorithms, such as (v) shape-based averaging (SBA) and (vi) Hofmann's pseudo-CT generation method. The performance evaluation of the different segmentation techniques was carried...... criterion, global weighting atlas fusion methods provided moderate improvement of whole-body bone segmentation (DSC ='0.65'±'0.05) compared to non-weighted IA (DSC ='0.60'±'0.02). The local weighed atlas fusion approach using the MSD similarity measure outperformed the other strategies by achieving a DSC...

  12. A Dataset and a Technique for Generalized Nuclear Segmentation for Computational Pathology.

    Science.gov (United States)

    Kumar, Neeraj; Verma, Ruchika; Sharma, Sanuj; Bhargava, Surabhi; Vahadane, Abhishek; Sethi, Amit

    2017-03-06

    Nuclear segmentation in digital microscopic tissue images can enable extraction of high-quality features for nuclear morphometrics and other analysis in computational pathology. Conventional image processing techniques such as Otsu thresholding and watershed segmentation do not work effectively on challenging cases, such as chromatin-sparse and crowded nuclei. In contrast, machine learning-based segmentation can generalize across various nuclear appearances. However, training machine learning algorithms require datasets of images in which a vast number of nuclei have been annotated. Publicly accessible and annotated datasets, along with widely agreed upon metrics to compare techniques, have catalyzed tremendous innovation and progress on other image classification problems, particularly in object recognition. Inspired by their success, we introduce a large publicly accessible dataset of H&E stained tissue images with more than 21,000 painstakingly annotated nuclear boundaries, whose quality was validated by a medical doctor. Because our dataset is taken from multiple hospitals and includes a diversity of nuclear appearances from several patients, disease states, and organs, techniques trained on it are likely to generalize well and work right out-of-the-box on other H&E stained images. We also propose a new metric to evaluate nuclear segmentation results that penalizes object- and pixel-level errors in a unified manner, unlike previous metrics that penalize only one type of error. We also propose a segmentation technique based on deep learning that lays special emphasis on identifying the nuclear boundaries, including those between the touching or overlapping nuclei, and works well on a diverse set of test images.

  13. Automatic segmentation of blood vessels from retinal fundus images through image processing and data mining techniques

    Indian Academy of Sciences (India)

    R Geetharamani; Lakshmi Balasubramanian

    2015-09-01

    Machine Learning techniques have been useful in almost every field of concern. Data Mining, a branch of Machine Learning is one of the most extensively used techniques. The ever-increasing demands in the field of medicine are being addressed by computational approaches in which Big Data analysis, image processing and data mining are on top priority. These techniques have been exploited in the domain of ophthalmology for better retinal fundus image analysis. Blood vessels, one of the most significant retinal anatomical structures are analysed for diagnosis of many diseases like retinopathy, occlusion and many other vision threatening diseases. Vessel segmentation can also be a pre-processing step for segmentation of other retinal structures like optic disc, fovea, microneurysms, etc. In this paper, blood vessel segmentation is attempted through image processing and data mining techniques. 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 algorithm and second level classification using C4.5 enhanced with bagging techniques. Association of every pixel against the feature vector necessitates Big Data analysis. The proposed methodology was evaluated on a publicly available database, STARE. The results reported 95.05% accuracy on entire dataset; however the accuracy was 95.20% on normal images and 94.89% on pathological images. A comparison of these results with the existing methodologies is also reported. This methodology can help ophthalmologists in better and faster analysis and hence early treatment to the patients.

  14. Recent Results with a segmented Hybrid Photon Detector for a novel parallax-free PET Scanner for Brain Imaging

    CERN Document Server

    Braem, André; Joram, Christian; Mathot, Serge; Séguinot, Jacques; Weilhammer, Peter; Ciocia, F; De Leo, R; Nappi, E; Vilardi, I; Argentieri, A; Corsi, F; Dragone, A; Pasqua, D

    2007-01-01

    We describe the design, fabrication and test results of a segmented Hybrid Photon Detector with integrated auto-triggering front-end electronics. Both the photodetector and its VLSI readout electronics are custom designed and have been tailored to the requirements of a recently proposed novel geometrical concept of a Positron Emission Tomograph. Emphasis is laid on the PET specific features of the device. The detector has been fabricated in the photocathode facility at CERN.

  15. Recent results with a segmented Hybrid Photon Detector for a novel, parallax-free PET Scanner for Brain Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Braem, A. [CERN, PH Department, CH-1211 Geneva (Switzerland); Chesi, E. [CERN, PH Department, CH-1211 Geneva (Switzerland); Joram, C. [CERN, PH Department, CH-1211 Geneva (Switzerland); Mathot, S. [CERN, PH Department, CH-1211 Geneva (Switzerland); Seguinot, J. [CERN, PH Department, CH-1211 Geneva (Switzerland); Weilhammer, P. [CERN, PH Department, CH-1211 Geneva (Switzerland)]. E-mail: Peter.Weilhammer@cern.ch; Ciocia, F. [INFN, Sezione di Bari and University of Bari, Bari (Italy); De Leo, R. [INFN, Sezione di Bari and University of Bari, Bari (Italy); Nappi, E. [INFN, Sezione di Bari and University of Bari, Bari (Italy); Vilardi, I. [INFN, Sezione di Bari and University of Bari, Bari (Italy); Argentieri, A. [INFN, Sezione di Bari and Politechnic of Bari, Bari (Italy); Corsi, F. [INFN, Sezione di Bari and Politechnic of Bari, Bari (Italy); Dragone, A. [INFN, Sezione di Bari and Politechnic of Bari, Bari (Italy); Pasqua, D. [INFN, Sezione di Bari and Politechnic of Bari, Bari (Italy)

    2007-02-01

    We describe the design, fabrication and test results of a segmented Hybrid Photon Detector with integrated auto-triggering front-end electronics. Both the photodetector and its VLSI readout electronics are custom designed and have been tailored to the requirements of a recently proposed novel geometrical concept of a Positron Emission Tomograph. Emphasis is laid on the PET specific features of the device. The detector has been fabricated in the photocathode facility at CERN.

  16. A segmented Hybrid Photon Detector with integrated auto-triggering front-end electronics for a PET scanner

    CERN Document Server

    Chesi, Enrico Guido; Joram, C; Mathot, S; Séguinot, Jacques; Weilhammer, P; Ciocia, F; De Leo, R; Nappi, E; Vilardi, I; Argentieri, A; Corsi, F; Dragone, A; Pasqua, D

    2006-01-01

    We describe the design, fabrication and test results of a segmented Hybrid Photon Detector with integrated auto-triggering front-end electronics. Both the photodetector and its VLSI readout electronics are custom designed and have been tailored to the requirements of a recently proposed novel geometrical concept of a Positron Emission Tomograph. Emphasis is put on the PET specific features of the device. The detector has been fabricated in the photocathode facility at CERN.

  17. Control strategy of interlinking converters as the key segment of hybrid AC–DC microgrids

    DEFF Research Database (Denmark)

    Baharizadeh, Mehdi; Karshenas, Hamid Reza; Guerrero, Josep M.

    2016-01-01

    , which again deteriorates the IC ac-side voltage quality. The proposed strategy is based on droop method, similar to what is used in the autonomous control of sources in an AC-MG. This technique uses voltage-controlled method and does not need frequency measurement in its structure. This considerably......This study is concerned with presenting control strategy for interlink converters in hybrid microgrids. When both ac microgrids (AC-MGs) and dc microgrids are in the vicinity of each other, they can be interconnected via ac-dc converters, known as ICs, making it possible to exchange energy between...... two grids. Common methods employed in IC control strategy use frequency variation and CCM in their structure. This method requires the frequency variation at IC ac-side to be large, leading to poor power quality and stability of AC-MG. Furthermore, CCM does not directly regulate the IC ac-side voltage...

  18. A real-time technique for optical alignment of telescopes with segmented optics

    Science.gov (United States)

    DiVittorio, Michael; Gathright, John

    2003-02-01

    While telescopes with segmented optics (currently Keck and HET and in the future GTC, CELT, GSMT, NGST, etc) present extra challenges in terms of optical alignment, they also present the opportunity for using an alignment technique not available to telescopes with monolithic optics. We present a technique for aligning telescope secondary mirrors utilizing the segmented nature of the primary. The data required is gathered in direct image mode and can be collected from science instrument detectors (as compared to a wavefront sensor). From this data aberrations (focus and coma) are calculated from which secondary piston and tip/tilt (or decenter) corrections are determined. In addition, tip/tilt corrections for each of the primary mirror segments can also be calculated. Furthermore, other aberrations are available to determine other alignment or support issues including differentiating secondary tip/tilt from decenter, focal surface tilt, and instrument aberrations. This technique has been used nightly on the Keck I and II telescopes over the last 8 years and has made a significant improvement in image quality.

  19. A Segmental Approach with SWT Technique for Denoising the EOG Signal

    Directory of Open Access Journals (Sweden)

    Naga Rajesh

    2015-01-01

    Full Text Available The Electrooculogram (EOG signal is often contaminated with artifacts and power-line while recording. It is very much essential to denoise the EOG signal for quality diagnosis. The present study deals with denoising of noisy EOG signals using Stationary Wavelet Transformation (SWT technique by two different approaches, namely, increasing segments of the EOG signal and different equal segments of the EOG signal. For performing the segmental denoising analysis, an EOG signal is simulated and added with controlled noise powers of 5 dB, 10 dB, 15 dB, 20 dB, and 25 dB so as to obtain five different noisy EOG signals. The results obtained after denoising them are extremely encouraging. Root Mean Square Error (RMSE values between reference EOG signal and EOG signals with noise powers of 5 dB, 10 dB, and 15 dB are very less when compared with 20 dB and 25 dB noise powers. The findings suggest that the SWT technique can be used to denoise the noisy EOG signal with optimum noise powers ranging from 5 dB to 15 dB. This technique might be useful in quality diagnosis of various neurological or eye disorders.

  20. IMPROVED HYBRID SEGMENTATION OF BRAIN MRI TISSUE AND TUMOR USING STATISTICAL FEATURES

    OpenAIRE

    S. Allin Christe; K. Malathy; A.Kandaswamy

    2010-01-01

    Medical image segmentation is the most essential and crucial process in order to facilitate the characterization and visualization of the structure of interest in medical images. Relevant application in neuroradiology is the segmentation of MRI data sets of the human brain into the structure classes gray matter, white matter and cerebrospinal fluid (CSF) and tumor. In this paper, brain image segmentation algorithms such as Fuzzy C means (FCM) segmentation and Kohonen means(K means) segmentati...

  1. OFF-LINE HANDWRITING RECOGNITION USING VARIOUS HYBRID MODELING TECHNIQUES AND CHARACTER N-GRAMS

    NARCIS (Netherlands)

    Brakensiek, A.; Rottland, J.; Kosmala, A.; Rigoll, G.

    2004-01-01

    In this paper a system for on-line cursive handwriting recognition is described. The system is based on Hidden Markov Models (HMMs) using discrete and hybrid modeling techniques. Here, we focus on two aspects of the recognition system. First, we present different hybrid modeling techniques, whereas

  2. Comparison of atlas-based techniques for whole-body bone segmentation.

    Science.gov (United States)

    Arabi, Hossein; Zaidi, Habib

    2017-02-01

    We evaluate the accuracy of whole-body bone extraction from whole-body MR images using a number of atlas-based segmentation methods. The motivation behind this work is to find the most promising approach for the purpose of MRI-guided derivation of PET attenuation maps in whole-body PET/MRI. To this end, a variety of atlas-based segmentation strategies commonly used in medical image segmentation and pseudo-CT generation were implemented and evaluated in terms of whole-body bone segmentation accuracy. Bone segmentation was performed on 23 whole-body CT/MR image pairs via leave-one-out cross validation procedure. The evaluated segmentation techniques include: (i) intensity averaging (IA), (ii) majority voting (MV), (iii) global and (iv) local (voxel-wise) weighting atlas fusion frameworks implemented utilizing normalized mutual information (NMI), normalized cross-correlation (NCC) and mean square distance (MSD) as image similarity measures for calculating the weighting factors, along with other atlas-dependent algorithms, such as (v) shape-based averaging (SBA) and (vi) Hofmann's pseudo-CT generation method. The performance evaluation of the different segmentation techniques was carried out in terms of estimating bone extraction accuracy from whole-body MRI using standard metrics, such as Dice similarity (DSC) and relative volume difference (RVD) considering bony structures obtained from intensity thresholding of the reference CT images as the ground truth. Considering the Dice criterion, global weighting atlas fusion methods provided moderate improvement of whole-body bone segmentation (DSC= 0.65 ± 0.05) compared to non-weighted IA (DSC= 0.60 ± 0.02). The local weighed atlas fusion approach using the MSD similarity measure outperformed the other strategies by achieving a DSC of 0.81 ± 0.03 while using the NCC and NMI measures resulted in a DSC of 0.78 ± 0.05 and 0.75 ± 0.04, respectively. Despite very long computation time, the extracted

  3. PET-guided delineation of radiation therapy treatment volumes: a survey of image segmentation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Zaidi, Habib [Geneva University Hospital, Division of Nuclear Medicine, Geneva 4 (Switzerland); Geneva University, Geneva Neuroscience Center, Geneva (Switzerland); El Naqa, Issam [Washington University School of Medicine, Department of Radiation Oncology, St. Louis, MO (United States)

    2010-11-15

    Historically, anatomical CT and MR images were used to delineate the gross tumour volumes (GTVs) for radiotherapy treatment planning. The capabilities offered by modern radiation therapy units and the widespread availability of combined PET/CT scanners stimulated the development of biological PET imaging-guided radiation therapy treatment planning with the aim to produce highly conformal radiation dose distribution to the tumour. One of the most difficult issues facing PET-based treatment planning is the accurate delineation of target regions from typical blurred and noisy functional images. The major problems encountered are image segmentation and imperfect system response function. Image segmentation is defined as the process of classifying the voxels of an image into a set of distinct classes. The difficulty in PET image segmentation is compounded by the low spatial resolution and high noise characteristics of PET images. Despite the difficulties and known limitations, several image segmentation approaches have been proposed and used in the clinical setting including thresholding, edge detection, region growing, clustering, stochastic models, deformable models, classifiers and several other approaches. A detailed description of the various approaches proposed in the literature is reviewed. Moreover, we also briefly discuss some important considerations and limitations of the widely used techniques to guide practitioners in the field of radiation oncology. The strategies followed for validation and comparative assessment of various PET segmentation approaches are described. Future opportunities and the current challenges facing the adoption of PET-guided delineation of target volumes and its role in basic and clinical research are also addressed. (orig.)

  4. Brain tumor classification using the diffusion tensor image segmentation (D-SEG) technique

    Science.gov (United States)

    Jones, Timothy L.; Byrnes, Tiernan J.; Yang, Guang; Howe, Franklyn A.; Bell, B. Anthony; Barrick, Thomas R.

    2015-01-01

    Background There is an increasing demand for noninvasive brain tumor biomarkers to guide surgery and subsequent oncotherapy. We present a novel whole-brain diffusion tensor imaging (DTI) segmentation (D-SEG) to delineate tumor volumes of interest (VOIs) for subsequent classification of tumor type. D-SEG uses isotropic (p) and anisotropic (q) components of the diffusion tensor to segment regions with similar diffusion characteristics. Methods DTI scans were acquired from 95 patients with low- and high-grade glioma, metastases, and meningioma and from 29 healthy subjects. D-SEG uses k-means clustering of the 2D (p,q) space to generate segments with different isotropic and anisotropic diffusion characteristics. Results Our results are visualized using a novel RGB color scheme incorporating p, q and T2-weighted information within each segment. The volumetric contribution of each segment to gray matter, white matter, and cerebrospinal fluid spaces was used to generate healthy tissue D-SEG spectra. Tumor VOIs were extracted using a semiautomated flood-filling technique and D-SEG spectra were computed within the VOI. Classification of tumor type using D-SEG spectra was performed using support vector machines. D-SEG was computationally fast and stable and delineated regions of healthy tissue from tumor and edema. D-SEG spectra were consistent for each tumor type, with constituent diffusion characteristics potentially reflecting regional differences in tissue microstructure. Support vector machines classified tumor type with an overall accuracy of 94.7%, providing better classification than previously reported. Conclusions D-SEG presents a user-friendly, semiautomated biomarker that may provide a valuable adjunct in noninvasive brain tumor diagnosis and treatment planning. PMID:25121771

  5. Hybrid inverse lithography techniques for advanced hierarchical memories

    Science.gov (United States)

    Xiao, Guangming; Hooker, Kevin; Irby, Dave; Zhang, Yunqiang; Ward, Brian; Cecil, Tom; Hall, Brett; Lee, Mindy; Kim, Dave; Lucas, Kevin

    2014-03-01

    Traditional segment-based model-based OPC methods have been the mainstream mask layout optimization techniques in volume production for memory and embedded memory devices for many device generations. These techniques have been continually optimized over time to meet the ever increasing difficulties of memory and memory periphery patterning. There are a range of difficult issues for patterning embedded memories successfully. These difficulties include the need for a very high level of symmetry and consistency (both within memory cells themselves and between cells) due to circuit effects such as noise margin requirements in SRAMs. Memory cells and access structures consume a large percentage of area in embedded devices so there is a very high return from shrinking the cell area as much as possible. This aggressive scaling leads to very difficult resolution, 2D CD control and process window requirements. Additionally, the range of interactions between mask synthesis corrections of neighboring areas can extend well beyond the size of the memory cell, making it difficult to fully take advantage of the inherent designed cell hierarchy in mask pattern optimization. This is especially true for non-traditional (i.e., less dependent on geometric rule) OPC/RET methods such as inverse lithography techniques (ILT) which inherently have more model-based decisions in their optimizations. New inverse methods such as model-based SRAF placement and ILT are, however, well known to have considerable benefits in finding flexible mask pattern solutions to improve process window, improve 2D CD control, and improve resolution in ultra-dense memory patterns. They also are known to reduce recipe complexity and provide native MRC compliant mask pattern solutions. Unfortunately, ILT is also known to be several times slower than traditional OPC methods due to the increased computational lithographic optimizations it performs. In this paper, we describe and present results for a methodology to

  6. Lesion Detection in CT Images Using Deep Learning Semantic Segmentation Technique

    Science.gov (United States)

    Kalinovsky, A.; Liauchuk, V.; Tarasau, A.

    2017-05-01

    In this paper, the problem of automatic detection of tuberculosis lesion on 3D lung CT images is considered as a benchmark for testing out algorithms based on a modern concept of Deep Learning. For training and testing of the algorithms a domestic dataset of 338 3D CT scans of tuberculosis patients with manually labelled lesions was used. The algorithms which are based on using Deep Convolutional Networks were implemented and applied in three different ways including slice-wise lesion detection in 2D images using semantic segmentation, slice-wise lesion detection in 2D images using sliding window technique as well as straightforward detection of lesions via semantic segmentation in whole 3D CT scans. The algorithms demonstrate superior performance compared to algorithms based on conventional image analysis methods.

  7. A hybrid hierarchical approach for brain tissue segmentation by combining brain atlas and least square support vector machine.

    Science.gov (United States)

    Kasiri, Keyvan; Kazemi, Kamran; Dehghani, Mohammad Javad; Helfroush, Mohammad Sadegh

    2013-10-01

    In this paper, we present a new semi-automatic brain tissue segmentation method based on a hybrid hierarchical approach that combines a brain atlas as a priori information and a least-square support vector machine (LS-SVM). The method consists of three steps. In the first two steps, the skull is removed and the cerebrospinal fluid (CSF) is extracted. These two steps are performed using the toolbox FMRIB's automated segmentation tool integrated in the FSL software (FSL-FAST) developed in Oxford Centre for functional MRI of the brain (FMRIB). Then, in the third step, the LS-SVM is used to segment grey matter (GM) and white matter (WM). The training samples for LS-SVM are selected from the registered brain atlas. The voxel intensities and spatial positions are selected as the two feature groups for training and test. SVM as a powerful discriminator is able to handle nonlinear classification problems; however, it cannot provide posterior probability. Thus, we use a sigmoid function to map the SVM output into probabilities. The proposed method is used to segment CSF, GM and WM from the simulated magnetic resonance imaging (MRI) using Brainweb MRI simulator and real data provided by Internet Brain Segmentation Repository. The semi-automatically segmented brain tissues were evaluated by comparing to the corresponding ground truth. The Dice and Jaccard similarity coefficients, sensitivity and specificity were calculated for the quantitative validation of the results. The quantitative results show that the proposed method segments brain tissues accurately with respect to corresponding ground truth.

  8. Automated segmentation of the quadratus lumborum muscle from magnetic resonance images using a hybrid atlas based - geodesic active contour scheme.

    Science.gov (United States)

    Jurcak, V; Fripp, J; Engstrom, C; Walker, D; Salvado, O; Ourselin, S; Crozier, S

    2008-01-01

    This study presents a novel method for the automatic segmentation of the quadratus lumborum (QL) muscle from axial magnetic resonance (MR) images using a hybrid scheme incorporating the use of non-rigid registration with probabilistic atlases (PAs) and geodesic active contours (GACs). The scheme was evaluated on an MR database of 7mm axial images of the lumbar spine from 20 subjects (fast bowlers and athletic controls). This scheme involved several steps, including (i) image pre-processing, (ii) generation of PAs for the QL, psoas (PS) and erector spinae+multifidus (ES+MT) muscles and (iii) segmentation, using 3D GACs initialized and constrained by the propagation of the PAs using non-rigid registration. Pre-processing of the images involved bias field correction based on local entropy minimization with a bicubic spline model and a reverse diffusion interpolation algorithm to increase the slice resolution to 0.98 x 0.98 x 1.75mm. The processed images were then registered (affine and non-rigid) and used to generate an average atlas. The PAs for the QL, PS and ES+MT were then generated by propagation of manual segmentations. These atlases were further analysed with specialised filtering to constrain the QL segmentation from adjacent non-muscle tissues (kidney, fat). This information was then used in 3D GACs to obtain the final segmentation of the QL. The automatic segmentation results were compared with the manual segmentations using the Dice similarity metric (DSC), with a median DSC for the right and left QL muscles of 0.78 (mean = 0.77, sd=0.07) and 0.75 (mean =0.74, sd=0.07), respectively.

  9. AN EFFICIENT TECHNIQUE FOR RETINAL VESSEL SEGMENTATION AND DENOISING USING MODIFIED ISODATA AND CLAHE

    Directory of Open Access Journals (Sweden)

    Khan Bahadar Khan

    2016-11-01

    Full Text Available Retinal damage caused due to complications of diabetes is known as Diabetic Retinopathy (DR. In this case, the vision is obscured due to the damage of retinal tinny blood vessels of the retina. These tinny blood vessels may cause leakage which affect the vision and can lead to complete blindness. Identification of these new retinal vessels and their structure is essential for analysis of DR. Automatic blood vessels segmentation plays a significant role to assist subsequent automatic methodologies that aid to such analysis. In literature most of the people have used computationally hungry a strong preprocessing steps followed by a simple thresholding and post processing, But in our proposed technique we utilize an arrangement of  light pre-processing which consists of Contrast Limited Adaptive Histogram Equalization (CLAHE for contrast enhancement, a difference image of green channel from its Gaussian blur filtered image to remove local noise or geometrical object, Modified Iterative Self Organizing Data Analysis Technique (MISODATA for segmentation of vessel and non-vessel pixels based on global and local thresholding, and a strong  post processing using region properties (area, eccentricity to eliminate the unwanted region/segment, non-vessel pixels and noise that never been used to reject misclassified foreground pixels. The strategy is tested on the publically accessible DRIVE (Digital Retinal Images for Vessel Extraction and STARE (STructured Analysis of the REtina databases. The performance of proposed technique is assessed comprehensively and the acquired accuracy, robustness, low complexity and high efficiency and very less computational time that make the method an efficient tool for automatic retinal image analysis. Proposed technique perform well as compared to the existing strategies on the online available databases in term of accuracy, sensitivity, specificity, false positive rate, true positive rate and area under receiver

  10. Hybrid artificial pinning centers of elongated-nanorods and segmented-nanorods in YBa2Cu3O7 films

    Science.gov (United States)

    Horide, Tomoya; Sakamoto, Nobuhiro; Ichinose, Ataru; Otsubo, Koji; Kitamura, Takanori; Matsumoto, Kaname

    2016-10-01

    To control the anisotropy of critical current density (J c), hybrid artificial pinning centers (APCs) of elongated-nanorods and segmented-nanorods were incorporated into YBa2Cu3O7 films. The elongated-nanorods and segmented-nanorods were formed by fabricating multilayer films using YBa2Cu3O7+BaSnO3 targets with a different BaSnO3 content. According to the elastic calculation, the BaSnO3-free YBa2Cu3O7 regions between BaSnO3 segmented-nanorods were highly strained, resulting in their alignment along the c-axis. Pinning of the vortex kinks and straight vortices by the nanorod ends improved J c in a wide range around B//ab. The angular dependence of J c systematically varied with the multilayer structure of layer thickness and BSO content. J c depended on the layer thickness even with keeping the constant average BSO content, showing that the BaSnO3 distribution, as well as the average BaSnO3 content, affected the J c. The hybrid pinning effect of elongated-nanorods and nanorod ends improved the J c anisotropy although the effect was not so large in the present films. The control of strain and interface is expected to lead to further improvement of J c.

  11. A hybrid semi-automatic method for liver segmentation based on level-set methods using multiple seed points.

    Science.gov (United States)

    Yang, Xiaopeng; Yu, Hee Chul; Choi, Younggeun; Lee, Wonsup; Wang, Baojian; Yang, Jaedo; Hwang, Hongpil; Kim, Ji Hyun; Song, Jisoo; Cho, Baik Hwan; You, Heecheon

    2014-01-01

    The present study developed a hybrid semi-automatic method to extract the liver from abdominal computerized tomography (CT) images. The proposed hybrid method consists of a customized fast-marching level-set method for detection of an optimal initial liver region from multiple seed points selected by the user and a threshold-based level-set method for extraction of the actual liver region based on the initial liver region. The performance of the hybrid method was compared with those of the 2D region growing method implemented in OsiriX using abdominal CT datasets of 15 patients. The hybrid method showed a significantly higher accuracy in liver extraction (similarity index, SI=97.6 ± 0.5%; false positive error, FPE = 2.2 ± 0.7%; false negative error, FNE=2.5 ± 0.8%; average symmetric surface distance, ASD=1.4 ± 0.5mm) than the 2D (SI=94.0 ± 1.9%; FPE = 5.3 ± 1.1%; FNE=6.5 ± 3.7%; ASD=6.7 ± 3.8mm) region growing method. The total liver extraction time per CT dataset of the hybrid method (77 ± 10 s) is significantly less than the 2D region growing method (575 ± 136 s). The interaction time per CT dataset between the user and a computer of the hybrid method (28 ± 4 s) is significantly shorter than the 2D region growing method (484 ± 126 s). The proposed hybrid method was found preferred for liver segmentation in preoperative virtual liver surgery planning.

  12. Automatic lung segmentation from thoracic computed tomography scans using a hybrid approach with error detection.

    NARCIS (Netherlands)

    Rikxoort, E.M. van; Hoop, B. de; Viergever, M.A.; Prokop, M.; Ginneken, B. van

    2009-01-01

    Lung segmentation is a prerequisite for automated analysis of chest CT scans. Conventional lung segmentation methods rely on large attenuation differences between lung parenchyma and surrounding tissue. These methods fail in scans where dense abnormalities are present, which often occurs in clinical

  13. Image segmentation techniques for improved processing of landmine responses in ground-penetrating radar data

    Science.gov (United States)

    Torrione, Peter A.; Collins, Leslie

    2007-04-01

    As ground penetrating radar sensor phenomenology improves, more advanced statistical processing approaches become applicable to the problem of landmine detection in GPR data. Most previous studies on landmine detection in GPR data have focused on the application of statistics and physics based prescreening algorithms, new feature extraction approaches, and improved feature classification techniques. In the typical framework, prescreening algorithms provide spatial location information of anomalous responses in down-track / cross-track coordinates, and feature extraction algorithms are then tasked with generating low-dimensional information-bearing feature sets from these spatial locations. However in time-domain GPR, a significant portion of the data collected at prescreener flagged locations may be unrelated to the true anomaly responses - e.g. ground bounce response, responses either temporally "before" or "after" the anomalous response, etc. The ability to segment the information-bearing region of the GPR image from the background of the image may thus provide improved performance for feature-based processing of anomaly responses. In this work we will explore the application of Markov random fields (MRFs) to the problem of anomaly/background segmentation in GPR data. Preliminary results suggest the potential for improved feature extraction and overall performance gains via application of image segmentation approaches prior to feature extraction.

  14. Techniques to distinguish between electron and photon induced events using segmented germanium detectors

    Energy Technology Data Exchange (ETDEWEB)

    Kroeninger, K.

    2007-06-05

    Two techniques to distinguish between electron and photon induced events in germanium detectors were studied: (1) anti-coincidence requirements between the segments of segmented germanium detectors and (2) the analysis of the time structure of the detector response. An 18-fold segmented germanium prototype detector for the GERDA neutrinoless double beta-decay experiment was characterized. The rejection of photon induced events was measured for the strongest lines in {sup 60}Co, {sup 152}Eu and {sup 228}Th. An accompanying Monte Carlo simulation was performed and the results were compared to data. An overall agreement with deviations of the order of 5-10% was obtained. The expected background index of the GERDA experiment was estimated. The sensitivity of the GERDA experiment was determined. Special statistical tools were developed to correctly treat the small number of events expected. The GERDA experiment uses a cryogenic liquid as the operational medium for the germanium detectors. It was shown that germanium detectors can be reliably operated through several cooling cycles. (orig.)

  15. Coupling Turbulence in Hybrid LES-RANS Techniques

    Science.gov (United States)

    Woodruff, Stephen L.

    2011-01-01

    A formulation is proposed for hybrid LES-RANS computations that permits accurate computations during resolution changes, so that resolution may be changed at will in order to employ only as much resolution in each subdomain as is required by the physics. The two components of this formulation, establishing the accuracy of a hybrid model at constant resolutions throughout the RANS-to-LES range and maintaining that accuracy when resolution is varied, are demonstrated for decaying, homogeneous, isotropic turbulence.

  16. Hybrid Segmentation of Vessels and Automated Flow Measures in In-Vivo Ultrasound Imaging

    DEFF Research Database (Denmark)

    Moshavegh, Ramin; Martins, Bo; Hansen, Kristoffer Lindskov

    2016-01-01

    expert segmentations. The flowrig results also demonstrated that the PSVs measured from VFI had a mean relative error of 14.5% in comparison with the actual PSVs. The error for the PSVs measured from spectral Doppler was 29.5%, indicating that VFI is 15% more precise than spectral Doppler in PSV...... method implements automated VFI flow measures such as peak systolic velocity (PSV) and volume flow. An evaluation of the performance of the segmentation algorithm relative to expert manual segmentation of 60 frames randomly chosen from 6 ultrasound sequences (10 frame randomly chosen from each sequence...... measurement....

  17. Hybrid estimation technique for predicting butene concentration in polyethylene reactor

    Science.gov (United States)

    Mohd Ali, Jarinah; Hussain, M. A.

    2016-03-01

    A component of artificial intelligence (AI), which is fuzzy logic, is combined with the so-called conventional sliding mode observer (SMO) to establish a hybrid type estimator to predict the butene concentration in the polyethylene production reactor. Butene or co-monomer concentration is another significant parameter in the polymerization process since it will affect the molecular weight distribution of the polymer produced. The hybrid estimator offers straightforward formulation of SMO and its combination with the fuzzy logic rules. The error resulted from the SMO estimation will be manipulated using the fuzzy rules to enhance the performance, thus improved on the convergence rate. This hybrid estimation is able to estimate the butene concentration satisfactorily despite the present of noise in the process.

  18. Hybrid computer techniques for solving partial differential equations

    Science.gov (United States)

    Hammond, J. L., Jr.; Odowd, W. M.

    1971-01-01

    Techniques overcome equipment limitations that restrict other computer techniques in solving trivial cases. The use of curve fitting by quadratic interpolation greatly reduces required digital storage space.

  19. Segmental dynamics of polyethylene-alt-propylene studied by NMR spin echo techniques

    Science.gov (United States)

    Lozovoi, A.; Mattea, C.; Hofmann, M.; Saalwaechter, K.; Fatkullin, N.; Stapf, S.

    2017-06-01

    Segmental dynamics of a highly entangled melt of linear polyethylene-alt-propylene with a molecular weight of 200 kDa was studied with a novel proton nuclear magnetic resonance (NMR) approach based upon 1H → 2H isotope dilution as applied to a solid-echo build-up function ISE(t), which is constructed from the NMR spin echo signals arising from the Hahn echo (HE) and two variations of the solid-echo pulse sequence. The isotope dilution enables the separation of inter- and intramolecular contributions to this function and allows one to extract the segmental mean-squared displacements in the millisecond time range, which is hardly accessible by other experimental methods. The proposed technique in combination with time-temperature superposition yields information about segmental translation in polyethylene-alt-propylene over 6 decades in time from 10-6 s up to 1 s. The time dependence of the mean-squared displacement obtained in this time range clearly shows three regimes of power law with exponents, which are in good agreement with the tube-reptation model predictions for the Rouse model, incoherent reptation and coherent reptation regimes. The results at short times coincide with the fast-field cycling relaxometry and neutron spin echo data, yet, significantly extending the probed time range. Furthermore, the obtained data are verified as well by the use of the dipolar-correlation effect on the Hahn echo, which was developed before by the co-authors. At the same time, the amplitude ratio of the intermolecular part of the proton dynamic dipole-dipole correlation function over the intramolecular part obtained from the experimental data is not in agreement with the predictions of the tube-reptation model for the regimes of incoherent and coherent reptation.

  20. A hybrid method based on fuzzy clustering and local region-based level set for segmentation of inhomogeneous medical images.

    Science.gov (United States)

    Rastgarpour, Maryam; Shanbehzadeh, Jamshid; Soltanian-Zadeh, Hamid

    2014-08-01

    medical images are more affected by intensity inhomogeneity rather than noise and outliers. This has a great impact on the efficiency of region-based image segmentation methods, because they rely on homogeneity of intensities in the regions of interest. Meanwhile, initialization and configuration of controlling parameters affect the performance of level set segmentation. To address these problems, this paper proposes a new hybrid method that integrates a local region-based level set method with a variation of fuzzy clustering. Specifically it takes an information fusion approach based on a coarse-to-fine framework that seamlessly fuses local spatial information and gray level information with the information of the local region-based level set method. Also, the controlling parameters of level set are directly computed from fuzzy clustering result. This approach has valuable benefits such as automation, no need to prior knowledge about the region of interest (ROI), robustness on intensity inhomogeneity, automatic adjustment of controlling parameters, insensitivity to initialization, and satisfactory accuracy. So, the contribution of this paper is to provide these advantages together which have not been proposed yet for inhomogeneous medical images. Proposed method was tested on several medical images from different modalities for performance evaluation. Experimental results approve its effectiveness in segmenting medical images in comparison with similar methods.

  1. A Hybrid Islanding Detection Technique Using Average Rate of Voltage Change and Real Power Shift

    DEFF Research Database (Denmark)

    Mahat, Pukar; Chen, Zhe; Bak-Jensen, Birgitte

    2009-01-01

    technique is proposed to solve this problem. An average rate of voltage change (passive technique) has been used to initiate a real power shift (active technique), which changes the eal power of distributed generation (DG), when the passive technique cannot have a clear discrimination between islanding......The mainly used islanding detection techniques may be classified as active and passive techniques. Passive techniques don't perturb the system but they have larger nondetection znes, whereas active techniques have smaller nondetection zones but they perturb the system. In this paper, a new hybrid...

  2. Direct detection of expanded trinucleotide repeats using DNA hybridization techniques

    Energy Technology Data Exchange (ETDEWEB)

    Petronis, A.; Tatuch, Y.; Kennedy, J.L. [Univ. of Toronto (Canada)] [and others

    1994-09-01

    Recently, unstable trinucleotide repeats have been shown to be the etiologic factor in several neuropsychiatric diseases, and they may play a similar role in other disorders. To our knowledge, a method that detects expanded trinucleotide sequences with the opportunity for direct localization and cloning has not been achieved. We have developed a set of hybridization-based methods for direct detection of unstable DNA expansion. Our analysis of myotonic dystrophy patients that possess different degrees of (CTG){sub n} expansion, versus unaffected controls, has demonstrated the identification of the trinucleotide instability site without any prior information regarding genetic map location. High stringency modified Southern blot hybridization with a PCR-generated trinucleotide repeat probe allowed us to detect the DNA fragment containing the expansion in myotonic dystrophy patients. The same probe was used for fluorescent in situ hybridization and several regions of (CTG){sub n}/(CAG){sub n} repeats in the human genome were detected, including the myotonic dystrophy locus on chromosome 19q. These strategies can be applied to directly clone genes involved in disorders caused by unstable DNA.

  3. Application of asymptotic waveform approximation technique to hybrid FE/BI method for 3D scattering

    Institute of Scientific and Technical Information of China (English)

    PENG Zhen; SHENG XinQing

    2007-01-01

    The asymptotic waveform evaluation (AWE) technique is a rational function approximation method in computational mathematics, which is used in many applications in computational electromagnetics. In this paper, the performance of the AWE technique in conjunction with hybrid finite element/boundary integral (FE/BI) method is firstly investigated. The formulation of the AWE applied in hybrid FE/BI method is given in detail. The characteristic implementation of the application of the AWE to the hybrid FE/BI method is discussed. Numerical results demonstrate that the AWE technique can greatly speed up the hybrid FE/BI method to acquire wide-band and wide-angle backscatter radar-cross-section (RCS) by complex targets.

  4. An objective evaluation framework for segmentation techniques of functional positron emission tomography studies

    CERN Document Server

    Kim, J; Eberl, S; Feng, D

    2004-01-01

    Segmentation of multi-dimensional functional positron emission tomography (PET) studies into regions of interest (ROI) exhibiting similar temporal behavior is useful in diagnosis and evaluation of neurological images. Quantitative evaluation plays a crucial role in measuring the segmentation algorithm's performance. Due to the lack of "ground truth" available for evaluating segmentation of clinical images, automated segmentation results are usually compared with manual delineation of structures which is, however, subjective, and is difficult to perform. Alternatively, segmentation of co-registered anatomical images such as magnetic resonance imaging (MRI) can be used as the ground truth to the PET segmentation. However, this is limited to PET studies which have corresponding MRI. In this study, we introduce a framework for the objective and quantitative evaluation of functional PET study segmentation without the need for manual delineation or registration to anatomical images of the patient. The segmentation ...

  5. Paraesthesia during the needle-through-needle and the double segment technique for combined spinal epidural anaesthesia.

    Science.gov (United States)

    Ahn, H J; Choi, D H; Kim, C S

    2006-07-01

    Paraesthesia during regional anaesthesia is an unpleasant sensation for patients and, more importantly, in some cases it is related to neurological injury. Relatively few studies have been conducted on the frequency of paraesthesia during combined spinal epidural anaesthesia. We compared two combined spinal epidural anaesthesia techniques: the needle-through-needle technique and the double segment technique in this respect. We randomly allocated 116 parturients undergoing elective Caesarean section to receive anaesthesia using one of these techniques. Both techniques were performed using a 27G pencil point needle, an 18G Tuohy needle, and a 20G multiport epidural catheter from the same manufacturer. The overall frequency of paraesthesia was higher in the needle-through-needle technique group (56.9% vs. 31.6%, p = 0.011). The frequency of paraesthesia at spinal needle insertion was 20.7% in the needle-through-needle technique group and 8.8% in the double segment technique group; whereas the frequency of paraesthesia at epidural catheter insertion was 46.6% in the needle-through-needle technique group and 24.6% in the double segment technique group.

  6. Segmentation of Lungs via Hybridization of CA and Level Set Algorithm

    National Research Council Canada - National Science Library

    A. Anbu Megelin Star; P. Subburaj

    2014-01-01

    ...) and then the level set algorithm is applied for acquiring the acute tumor tissues. As a result of the mentioned process, the tumor sector is segmented and the results are depicted. Studies on lung tumor datasets demonstrate 80-85% overlap performance of the proposed algorithm with less sensitivity to seed initialization, robustness with respect to heterogeneous tumor types and its efficiency in terms of computation time.

  7. [Cotton identification and extraction using near infrared sensor and object-oriented spectral segmentation technique].

    Science.gov (United States)

    Deng, Jin-Song; Shi, Yuan-Yuan; Chen, Li-Su; Wang, Ke; Zhu, Jin-Xia

    2009-07-01

    The real-time, effective and reliable method of identifying crop is the foundation of scientific management for crop in the precision agriculture. It is also one of the key techniques for the precision agriculture. However, this expectation cannot be fulfilled by the traditional pixel-based information extraction method with respect to complicated image processing and accurate objective identification. In the present study, visible-near infrared image of cotton was acquired using high-resolution sensor. Object-oriented segmentation technique was performed on the image to produce image objects and spatial/spectral features of cotton. Afterwards, nearest neighbor classifier integrated the spectral, shape and topologic information of image objects to precisely identify cotton according to various features. Finally, 300 random samples and an error matrix were applied to undertake the accuracy assessment of identification. Although errors and confusion exist, this method shows satisfying results with an overall accuracy of 96.33% and a KAPPA coefficient of 0.926 7, which can meet the demand of automatic management and decision-making in precision agriculture.

  8. Resizing Technique-Based Hybrid Genetic Algorithm for Optimal Drift Design of Multistory Steel Frame Buildings

    Directory of Open Access Journals (Sweden)

    Hyo Seon Park

    2014-01-01

    Full Text Available Since genetic algorithm-based optimization methods are computationally expensive for practical use in the field of structural optimization, a resizing technique-based hybrid genetic algorithm for the drift design of multistory steel frame buildings is proposed to increase the convergence speed of genetic algorithms. To reduce the number of structural analyses required for the convergence, a genetic algorithm is combined with a resizing technique that is an efficient optimal technique to control the drift of buildings without the repetitive structural analysis. The resizing technique-based hybrid genetic algorithm proposed in this paper is applied to the minimum weight design of three steel frame buildings. To evaluate the performance of the algorithm, optimum weights, computational times, and generation numbers from the proposed algorithm are compared with those from a genetic algorithm. Based on the comparisons, it is concluded that the hybrid genetic algorithm shows clear improvements in convergence properties.

  9. A novel technique of three-dimensional reconstruction segmentation and analysis for sliced images of biological tissues

    Institute of Scientific and Technical Information of China (English)

    LI Jing; ZHAO Hai-yan; RUAN Xing-yun; XU Yong-qing; MENG Wei-zheng; LI Kun-peng; ZHANG Jing-qiang

    2005-01-01

    A novel technique of three-dimensional (3D) reconstruction, segmentation, display and analysis of series slices of images including microscopic wide field optical sectioning by deconvolution method, cryo-electron microscope slices by Fourier-Bessel synthesis and electron tomography (ET), and a series of computed tomography (CT) was developed to perform simultaneous measurement on the structure and function of biomedical samples. The paper presents the 3D reconstruction segmentation display and analysis results of pollen spore, chaperonin, virus, head, cervical bone, tibia and carpus. At the same time, it also puts forward some potential applications of the new technique in the biomedical realm.

  10. Preventing proximal junctional failure in long segmental instrumented cases of adult degenerative scoliosis using a multilevel stabilization screw technique

    Directory of Open Access Journals (Sweden)

    Lee Sandquist

    2015-01-01

    Conclusion: PJK and failure are well-recognized suboptimal outcomes of long-segmental fusions of the thoracolumbar spine that can lead to significant neurological morbidity and costly revision surgeries. With no known proximal junction failures to date, the MLSS technique has shown promising results in preventing adverse proximal junctional conditions and can be safely performed under fluoroscopy guidance. Future direction includes a comparative study establishing the relative risk of developing PJK with this novel technique versus a traditional long-segmental thoracolumbar fusion.

  11. A Hybrid IMRT/VMAT Technique for the Treatment of Nasopharyngeal Cancer

    Directory of Open Access Journals (Sweden)

    Nan Zhao

    2015-01-01

    Full Text Available Hybrid IMRT/VMAT technique which combined intensity modulated radiotherapy (IMRT and volumetric modulated arc therapy (VMAT was developed for the treatment of nasopharyngeal cancer (NPC. Two-full-arc VMAT (2ARC-VMAT, 9-field IMRT (9F-IMRT, and Hybrid IMRT/VMAT plans for NPC were compared in terms of the dosimetric quality, sparing of organs at risk (OARs, and delivery efficiency. The Hybrid IMRT/VMAT technique can improve the target dose homogeneity and conformity compared with 9F-IMRT and 2ARC-VMAT. It can reduce the dose delivered to the TMJ, mandible, temporal lobe, and unspecified tissue with fewer MUs compared with 9F-IMRT and dose delivered to parotids, brainstem, and spinal cord compared with 2ARC-VMAT technique. The mean delivery time of Hybrid plans was shorter than that of 9F-IMRT plans (408 s versus 812 s; P=0.00 and longer than that of 2ARC-VMAT plans (408 s versus 179 s; P=0.00. Hybrid IMRT/VMAT technique could be a viable radiotherapy technique with better plan quality.

  12. A hybrid IMRT/VMAT technique for the treatment of nasopharyngeal cancer.

    Science.gov (United States)

    Zhao, Nan; Yang, Ruijie; Jiang, Yuliang; Tian, Suqing; Guo, Fuxin; Wang, Junjie

    2015-01-01

    Hybrid IMRT/VMAT technique which combined intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) was developed for the treatment of nasopharyngeal cancer (NPC). Two-full-arc VMAT (2ARC-VMAT), 9-field IMRT (9F-IMRT), and Hybrid IMRT/VMAT plans for NPC were compared in terms of the dosimetric quality, sparing of organs at risk (OARs), and delivery efficiency. The Hybrid IMRT/VMAT technique can improve the target dose homogeneity and conformity compared with 9F-IMRT and 2ARC-VMAT. It can reduce the dose delivered to the TMJ, mandible, temporal lobe, and unspecified tissue with fewer MUs compared with 9F-IMRT and dose delivered to parotids, brainstem, and spinal cord compared with 2ARC-VMAT technique. The mean delivery time of Hybrid plans was shorter than that of 9F-IMRT plans (408 s versus 812 s; P=0.00) and longer than that of 2ARC-VMAT plans (408 s versus 179 s; P=0.00). Hybrid IMRT/VMAT technique could be a viable radiotherapy technique with better plan quality.

  13. A Hybrid IMRT/VMAT Technique for the Treatment of Nasopharyngeal Cancer

    Science.gov (United States)

    Zhao, Nan; Yang, Ruijie; Jiang, Yuliang; Tian, Suqing; Guo, Fuxin; Wang, Junjie

    2015-01-01

    Hybrid IMRT/VMAT technique which combined intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) was developed for the treatment of nasopharyngeal cancer (NPC). Two-full-arc VMAT (2ARC-VMAT), 9-field IMRT (9F-IMRT), and Hybrid IMRT/VMAT plans for NPC were compared in terms of the dosimetric quality, sparing of organs at risk (OARs), and delivery efficiency. The Hybrid IMRT/VMAT technique can improve the target dose homogeneity and conformity compared with 9F-IMRT and 2ARC-VMAT. It can reduce the dose delivered to the TMJ, mandible, temporal lobe, and unspecified tissue with fewer MUs compared with 9F-IMRT and dose delivered to parotids, brainstem, and spinal cord compared with 2ARC-VMAT technique. The mean delivery time of Hybrid plans was shorter than that of 9F-IMRT plans (408 s versus 812 s; P = 0.00) and longer than that of 2ARC-VMAT plans (408 s versus 179 s; P = 0.00). Hybrid IMRT/VMAT technique could be a viable radiotherapy technique with better plan quality. PMID:25688371

  14. Test and numerical simulation of a new type of hybrid control technique

    Institute of Scientific and Technical Information of China (English)

    Meng Qingli; Zhang Minzheng; Cheng Dong

    2005-01-01

    In this paper, a new hybrid control technique, based on a combination of base-isolation and semi-active variable stiffness/damping in a superstructure, is presented. To illustrate the efficiency of the proposed control system, model tests on a mini-electromagnetic shaking table and a numerical simulation were performed. The test and numerical calculation results indicate that this new hybrid control mode with additional damping and smaller additional stiffness can achieve a better control efficiency.

  15. Management of internal resorption of central incisor using hybrid technique.

    Science.gov (United States)

    Gayathri, Prabakaran; Pandey, Ramesh Kumar; Jain, Eesha

    2014-01-28

    Internal inflammatory root resorption is characterised by progressive destruction of intraradicular dentin and dentinal tubules along the root canal wall. A number of theories have been proposed as a possible cause for internal resorption. It is usually asymptomatic and detected during routine radiographic investigations. Prompt diagnosis and early management of such defects is essential to maintain the integrity of the tooth. Non-surgical and surgical methods are the two main strategies involved in the management of internal resorption. The non-surgical method is usually preferred, but in cases of extensive resorption with external root perforation, surgical intervention has been advocated. The present case illustrates repair of perforating internal resorption by hybrid method, using mineral trioxide aggregate and gutta-percha, following surgical exposure. After a 10-month follow-up, no clinical and radiographic abnormalities were observed. Additionally, there was also marked reduction in periodontal pocket depth.

  16. Constrained Optimization Based on Hybrid Evolutionary Algorithm and Adaptive Constraint-Handling Technique

    DEFF Research Database (Denmark)

    Wang, Yong; Cai, Zixing; Zhou, Yuren

    2009-01-01

    A novel approach to deal with numerical and engineering constrained optimization problems, which incorporates a hybrid evolutionary algorithm and an adaptive constraint-handling technique, is presented in this paper. The hybrid evolutionary algorithm simultaneously uses simplex crossover and two...... mutation operators to generate the offspring population. Additionally, the adaptive constraint-handling technique consists of three main situations. In detail, at each situation, one constraint-handling mechanism is designed based on current population state. Experiments on 13 benchmark test functions...... and four well-known constrained design problems verify the effectiveness and efficiency of the proposed method. The experimental results show that integrating the hybrid evolutionary algorithm with the adaptive constraint-handling technique is beneficial, and the proposed method achieves competitive...

  17. Large-scale multi-zone optimal power dispatch using hybrid hierarchical evolution technique

    Directory of Open Access Journals (Sweden)

    Manjaree Pandit

    2014-03-01

    Full Text Available A new hybrid technique based on hierarchical evolution is proposed for large, non-convex, multi-zone economic dispatch (MZED problems considering all practical constraints. Evolutionary/swarm intelligence-based optimisation techniques are reported to be effective only for small/medium-sized power systems. The proposed hybrid hierarchical evolution (HHE algorithm is specifically developed for solving large systems. The HHE integrates the exploration and exploitation capabilities of particle swarm optimisation and differential evolution in a novel manner such that the search efficiency is improved substantially. Most hybrid techniques export or exchange features or operations from one algorithm to the other, but in HHE their entire individual features are retained. The effectiveness of the proposed algorithm has been verified on six-test systems having different sizes and complexity levels. Non-convex MZED solution for such large and complex systems has not yet been reported.

  18. [Leaf characteristics extraction of rice under potassium stress based on static scan and spectral segmentation technique].

    Science.gov (United States)

    Shi, Yuan-yuan; Deng, Jin-song; Chen, Li-su; Zhang, Dong-yan; Ding, Xiao-dong; Wang, Ke

    2010-01-01

    The timing, convenient and reliable method of diagnosing and monitoring crop nutrition is the foundation of scientific fertilization management. However, this expectation cannot be fulfilled by traditional methods, which always need excessively work on sampling, detection and analysis and even exhibit lagging timing. In the present study, stable images for potassium-stressed leaf were acquired using stationary scanning, and object-oriented segmentation technique was adopted to produce image objects. Afterwards, nearest neighbor classifier integrated the spectral, shape and topologic information of image objects to precisely identify characteristics of potassium-stressed features. Diagnosing with image, the 3rd expanded leaves are superior to the 1st expanded leaves. In order to assess the result, 250 random samples and an error matrix were applied to undertake the accuracy assessment of identification. The results showed that the overall accuracy and kappa coefficient was 96.00% and 0.9453 respectively. The study offered an information extraction method for quantitative diagnosis of rice under potassium stress.

  19. Single Molecule Techniques for Advanced in situ Hybridization

    Energy Technology Data Exchange (ETDEWEB)

    Hollars, C W; Stubbs, L; Carlson, K; Lu, X; Wehri, E

    2003-02-03

    One of the most significant achievements of modern science is completion of the human genome sequence, completed in the year 2000. Despite this monumental accomplishment, researchers have only begun to understand the relationships between this three-billion-nucleotide genetic code and the regulation and control of gene and protein expression within each of the millions of different types of highly specialized cells. Several methodologies have been developed for the analysis of gene and protein expression in situ, yet despite these advancements, the pace of such analyses is extremely limited. Because information regarding the precise timing and location of gene expression is a crucial component in the discovery of new pharmacological agents for the treatment of disease, there is an enormous incentive to develop technologies that accelerate the analytical process. Here we report on the use of plasmon resonant particles as advanced probes for in situ hybridization. These probes are used for the detection of low levels of gene-probe response and demonstrate a detection method that enables precise, simultaneous localization within a cell of the points of expression of multiple genes or proteins in a single sample.

  20. Evaluation of intrastromal corneal ring segments for treatment of keratoconus with a mechanical implantation technique

    Directory of Open Access Journals (Sweden)

    Zeki Tunc

    2013-01-01

    Full Text Available Purpose: To evaluate the clinical outcomes of intrastromal corneal ring segment (ICRS implantation in patients with keratoconus using a mechanical implantation technique. Materials and Methods: Thirty eyes of 17 patients with keratoconus were enrolled. ICRSs (Keraring were implanted after dissection of the tunnel using Tunc′s specially designed dissector under suction. A complete ophthalmic examination was performed, including uncorrected distance visual acuity (UDVA, corrected distance visual acuity (CDVA, spherical equivalent, keratometric readings, inferosuperior asymmetry index (ISAI, and ultrasound pachymetry. All 3-, 6-, and 12-month follow-ups were completed, and statistical analysis was performed. Results: The mean preoperative UDVA for all eyes was 1.36 ± 0.64 logMAR. At 12 months, the mean UDVA was 0.51 ± 0.28 logMAR (P = 0.001, and the mean preoperative CDVA was 0.57 ± 0.29 logMAR, which improved to 0.23 ± 0.18 (P = 0.001 at 1 year. There was a significant reduction in spherical equivalent refractive error from -6.42 ± 4.69 diopters (D preoperatively to -1.26 ± 1.45 D (P = 0.001 at 1 year. In the same period, the mean K-readings improved from 49.38 ± 3.72 D to 44.43 ± 3.13 D (P = 0.001, and the mean ISAI improved from 7.92 ± 3.12 to 4.21 ± 1.96 (P = 0.003. No significant changes in mean central corneal thickness were observed postoperatively. There were no major complications during and or after surgery. Conclusion: ICRS implantation using a unique mechanical dissection technique is a safe and effective treatment for keratoconus. All parameters improved by the 1-year follow-up.

  1. A hybrid classifier using the parallelepiped and Bayesian techniques. [for multispectral image data

    Science.gov (United States)

    Addington, J. D.

    1975-01-01

    A versatile classification scheme is developed which uses the best features of the parallelepiped algorithm and the Bayesian maximum likelihood algorithm. The parallelepiped technique has the advantage of being very fast, especially when implemented into a table look-up scheme; its disadvantage is its inability to distinguish and classify spectral signatures which are similar in nature. This disadvantage is eliminated by the Bayesian technique which is capable of distinguishing subtle differences very well. The hybrid algorithm developed reduces computer time by as much as 90%. A two- and n-dimensional description of the hybrid classifier is given.

  2. The Uses of Student Market Segmentation Techniques in College Recruitment. AIR Forum Paper 1978.

    Science.gov (United States)

    Spiro, Louis M.

    Student market segmentation separates prospective college students into subgroups with similar characteristics, the most commonly used being geography, demography, attitudes, and behavior. Recruitment efforts can then focus on student segments similar to the present student body or on other students that might be attracted. The goal is to make…

  3. GAUSSIAN MIXTURE MODEL BASED LEVEL SET TECHNIQUE FOR AUTOMATED SEGMENTATION OF CARDIAC MR IMAGES

    Directory of Open Access Journals (Sweden)

    G. Dharanibai,

    2011-04-01

    Full Text Available In this paper we propose a Gaussian Mixture Model (GMM integrated level set method for automated segmentation of left ventricle (LV, right ventricle (RV and myocardium from short axis views of cardiacmagnetic resonance image. By fitting GMM to the image histogram, global pixel intensity characteristics of the blood pool, myocardium and background are estimated. GMM provides initial segmentation andthe segmentation solution is regularized using level set. Parameters for controlling the level set evolution are automatically estimated from the Bayesian inference classification of pixels. We propose a new speed function that combines edge and region information that stops the evolving level set at the myocardial boundary. Segmentation efficacy is analyzed qualitatively via visual inspection. Results show the improved performance of our of proposed speed function over the conventional Bayesian driven adaptive speed function in automatic segmentation of myocardium

  4. Comparison of hybrid volumetric modulated arc therapy (VMAT technique and double arc VMAT technique in the treatment of prostate cancer

    Directory of Open Access Journals (Sweden)

    Amaloo Christopher

    2015-09-01

    Full Text Available Background. Volumetric modulated arc therapy (VMAT has quickly become accepted as standard of care for the treatment of prostate cancer based on studies showing it is able to provide faster delivery with adequate target coverage and reduced monitor units while maintaining organ at risk (OAR sparing. This study aims to demonstrate the potential to increase dose conformality with increased planner control and OAR sparing using a hybrid treatment technique compared to VMAT.

  5. HybridArc: A novel radiation therapy technique combining optimized dynamic arcs and intensity modulation

    Energy Technology Data Exchange (ETDEWEB)

    Robar, James L., E-mail: james.robar@cdha.nshealth.ca [Department of Radiation Oncology, Dalhousie University, Halifax (Canada); Department of Physics and Atmospheric Science, Dalhousie University, Halifax (Canada); Thomas, Christopher [Department of Radiation Oncology, Dalhousie University, Halifax (Canada)

    2012-01-01

    This investigation focuses on possible dosimetric and efficiency advantages of HybridArc-a novel treatment planning approach combining optimized dynamic arcs with intensity-modulated radiation therapy (IMRT) beams. Application of this technique to two disparate sites, complex cranial tumors, and prostate was examined. HybridArc plans were compared with either dynamic conformal arc (DCA) or IMRT plans to determine whether HybridArc offers a synergy through combination of these 2 techniques. Plans were compared with regard to target volume dose conformity, target volume dose homogeneity, sparing of proximal organs at risk, normal tissue sparing, and monitor unit (MU) efficiency. For cranial cases, HybridArc produced significantly improved dose conformity compared with both DCA and IMRT but did not improve sparing of the brainstem or optic chiasm. For prostate cases, conformity was improved compared with DCA but not IMRT. Compared with IMRT, the dose homogeneity in the planning target volume was improved, and the maximum doses received by the bladder and rectum were reduced. Both arc-based techniques distribute peripheral dose over larger volumes of normal tissue compared with IMRT, whereas HybridArc involved slightly greater volumes of normal tissues compared with DCA. Compared with IMRT, cranial cases required 38% more MUs, whereas for prostate cases, MUs were reduced by 7%. For cranial cases, HybridArc improves dose conformity to the target. For prostate cases, dose conformity and homogeneity are improved compared with DCA and IMRT, respectively. Compared with IMRT, whether required MUs increase or decrease with HybridArc was site-dependent.

  6. A Hybrid Neural Network-Genetic Algorithm Technique for Aircraft Engine Performance Diagnostics

    Science.gov (United States)

    Kobayashi, Takahisa; Simon, Donald L.

    2001-01-01

    In this paper, a model-based diagnostic method, which utilizes Neural Networks and Genetic Algorithms, is investigated. Neural networks are applied to estimate the engine internal health, and Genetic Algorithms are applied for sensor bias detection and estimation. This hybrid approach takes advantage of the nonlinear estimation capability provided by neural networks while improving the robustness to measurement uncertainty through the application of Genetic Algorithms. The hybrid diagnostic technique also has the ability to rank multiple potential solutions for a given set of anomalous sensor measurements in order to reduce false alarms and missed detections. The performance of the hybrid diagnostic technique is evaluated through some case studies derived from a turbofan engine simulation. The results show this approach is promising for reliable diagnostics of aircraft engines.

  7. A Robust Hybrid Video Watermarking Technique using Mosaicing

    Directory of Open Access Journals (Sweden)

    Jeebananda Panda

    2014-10-01

    Full Text Available Video Watermarking is the technique by which some information is inserted in the video which can be extracted later. It provides protection against any kind of illegal manipulation by third party. In this paper , a non -blind watermarking scheme is proposed which is based on the combination of Discrete Wavelet Transform,(DWT, Discrete Cosine Transform (DCT and Singular Value Decomposition (SVD.The watermark is embedded in the mosaic formed from the frames of the video by modifying the DCT coefficients of LL1 (low frequency sub-band obtained by applying 1-level DWT on the mosaic followed by diagonal based modification of singular value matrix which is obtained by SVD decomposition of LL2 (low frequency sub-band obtained by applying 2-level DWT on the modified LL1.The experimental values of PSNR, Correlation Factor show that the above proposed scheme is imperceptible, secure and robust against various types of attacks.

  8. High performance technique for database applicationsusing a hybrid GPU/CPU platform

    KAUST Repository

    Zidan, Mohammed A.

    2012-07-28

    Many database applications, such as sequence comparing, sequence searching, and sequence matching, etc, process large database sequences. we introduce a novel and efficient technique to improve the performance of database applica- tions by using a Hybrid GPU/CPU platform. In particular, our technique solves the problem of the low efficiency result- ing from running short-length sequences in a database on a GPU. To verify our technique, we applied it to the widely used Smith-Waterman algorithm. The experimental results show that our Hybrid GPU/CPU technique improves the average performance by a factor of 2.2, and improves the peak performance by a factor of 2.8 when compared to earlier implementations. Copyright © 2011 by ASME.

  9. A Plug-in Hybrid Consumer Choice Model with Detailed Market Segmentation

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Zhenhong [ORNL; Greene, David L [ORNL

    2010-01-01

    This paper describes a consumer choice model for projecting U.S. demand for plug-in hybrid electric vehicles (PHEV) in competition among 13 light-duty vehicle technologies over the period 2005-2050. New car buyers are disaggregated by region, residential area, attitude toward technology risk, vehicle usage intensity, home parking and work recharging. The nested multinomial logit (NMNL) model of vehicle choice incorporates daily vehicle usage distributions, refueling and recharging availability, technology learning by doing, and diversity of choice among makes and models. Illustrative results are presented for a Base Case, calibrated to the Annual Energy Outlook (AEO) 2009 Reference Updated Case, and an optimistic technology scenario reflecting achievement of U.S. Department of Energy s (DOE s) FreedomCAR goals. PHEV market success is highly dependent on the degree of technological progress assumed. PHEV sales reach one million in 2037 in the Base Case but in 2020 in the FreedomCARGoals Case. In the FreedomCARGoals Case, PHEV cumulative sales reach 1.5 million by 2015. Together with efficiency improvements in other technologies, petroleum use in 2050 is reduced by about 45% from the 2005 level. After technological progress, PHEV s market success appears to be most sensitive to recharging availability, consumers attitudes toward novel echnologies, and vehicle usage intensity. Successful market penetration of PHEVs helps bring down battery costs for electric vehicles (EVs), resulting in a significant EV market share after 2040.

  10. Automated brain tumor segmentation in magnetic resonance imaging based on sliding-window technique and symmetry analysis

    Institute of Scientific and Technical Information of China (English)

    Lian Yanyun; Song Zhijian

    2014-01-01

    Background Brain tumor segmentation from magnetic resonance imaging (MRI) is an important step toward surgical planning,treatment planning,monitoring of therapy.However,manual tumor segmentation commonly used in clinic is time-consuming and challenging,and none of the existed automated methods are highly robust,reliable and efficient in clinic application.An accurate and automated tumor segmentation method has been developed for brain tumor segmentation that will provide reproducible and objective results close to manual segmentation results.Methods Based on the symmetry of human brain,we employed sliding-window technique and correlation coefficient to locate the tumor position.At first,the image to be segmented was normalized,rotated,denoised,and bisected.Subsequently,through vertical and horizontal sliding-windows technique in turn,that is,two windows in the left and the right part of brain image moving simultaneously pixel by pixel in two parts of brain image,along with calculating of correlation coefficient of two windows,two windows with minimal correlation coefficient were obtained,and the window with bigger average gray value is the location of tumor and the pixel with biggest gray value is the locating point of tumor.At last,the segmentation threshold was decided by the average gray value of the pixels in the square with center at the locating point and 10 pixels of side length,and threshold segmentation and morphological operations were used to acquire the final tumor region.Results The method was evaluated on 3D FSPGR brain MR images of 10 patients.As a result,the average ratio of correct location was 93.4% for 575 slices containing tumor,the average Dice similarity coefficient was 0.77 for one scan,and the average time spent on one scan was 40 seconds.Conclusions An fully automated,simple and efficient segmentation method for brain tumor is proposed and promising for future clinic use.Correlation coefficient is a new and effective feature for tumor

  11. New digital demodulator with matched filters and curve segmentation techniques for BFSK demodulation: Analytical description

    OpenAIRE

    2015-01-01

    The present article relates in general to digital demodulation of Binary Frequency Shift Keying (BFSK). The objective of the present research is to obtain a new processing method for demodulating BFSK-signals in order to reduce hardware complexity in comparison with other methods reported. The solution proposed here makes use of the matched filter theory and curve segmentation algorithms. This paper describes the integration and configuration of a Sampler Correlator and curve segmentation blo...

  12. Locomotion training of legged robots using hybrid machine learning techniques

    Science.gov (United States)

    Simon, William E.; Doerschuk, Peggy I.; Zhang, Wen-Ran; Li, Andrew L.

    1995-01-01

    In this study artificial neural networks and fuzzy logic are used to control the jumping behavior of a three-link uniped robot. The biped locomotion control problem is an increment of the uniped locomotion control. Study of legged locomotion dynamics indicates that a hierarchical controller is required to control the behavior of a legged robot. A structured control strategy is suggested which includes navigator, motion planner, biped coordinator and uniped controllers. A three-link uniped robot simulation is developed to be used as the plant. Neurocontrollers were trained both online and offline. In the case of on-line training, a reinforcement learning technique was used to train the neurocontroller to make the robot jump to a specified height. After several hundred iterations of training, the plant output achieved an accuracy of 7.4%. However, when jump distance and body angular momentum were also included in the control objectives, training time became impractically long. In the case of off-line training, a three-layered backpropagation (BP) network was first used with three inputs, three outputs and 15 to 40 hidden nodes. Pre-generated data were presented to the network with a learning rate as low as 0.003 in order to reach convergence. The low learning rate required for convergence resulted in a very slow training process which took weeks to learn 460 examples. After training, performance of the neurocontroller was rather poor. Consequently, the BP network was replaced by a Cerebeller Model Articulation Controller (CMAC) network. Subsequent experiments described in this document show that the CMAC network is more suitable to the solution of uniped locomotion control problems in terms of both learning efficiency and performance. A new approach is introduced in this report, viz., a self-organizing multiagent cerebeller model for fuzzy-neural control of uniped locomotion is suggested to improve training efficiency. This is currently being evaluated for a possible

  13. GA and PSO culled hybrid technique for economic dispatch problem with prohibited operating zones

    Institute of Scientific and Technical Information of China (English)

    SUDHAKARAN M.; AJAY-D-VIMALRAJ P.; PALANIVELU T.G.

    2007-01-01

    This paper presents an efficient and reliable genetic algorithm (GA) based particle swarm optimization (PSO) technique (hybrid GAPSO) for solving the economic dispatch (ED) problem in power systems. The non-linear characteristics of the generators, such as prohibited operating zones, ramp rate limits and non-smooth cost functions of the practical generator operation are considered. The proposed hybrid algorithm is demonstrated for three different systems and the performance is compared with the GA and PSO in terms of solution quality and computation efficiency. Comparison of results proved that the proposed algorithm can obtain higher quality solutions efficiently in ED problems. A comprehensive software package is developed using MATLAB.

  14. Indirect porcelain veneers in periodontally compromised teeth. The hybrid technique: a case report.

    Science.gov (United States)

    Garcia-Baeza, David; Saavedra, Carlos; Garcia-Adámez, Ramón

    2015-01-01

    The loss of periodontal structure causes an esthetic problem for many patients, especially when the esthetic zone is compromised. Among the various types of solutions is the use of composite resins. While this procedure is not aggressive towards tooth structure, it does require the clinician to have a precise technique, and demands strict longterm maintenance. 1 Another way of treating the compromised teeth is with porcelain veneers. This procedure is especially difficult, however, if carried out on periodontal teeth, as it requires preparation along the roots. 2 The intention of the hybrid technique described in this article is to combine both of these procedures in order to obtain a less aggressive treatment with precise management of the soft tissue and an adequate esthetic outcome. The hybrid technique consists of enlarging the root portion of the teeth with composite resin to obtain a less aggressive tooth preparation, and thereafter placing porcelain veneers.

  15. Horse spleen segmentation technique as large animal model of preclinical trials.

    Science.gov (United States)

    Foz Filho, Roberto P P; Martin, Benedito W de; Lima, Ana Rita de; Miglino, Maria Angélica

    2013-01-01

    The parenchymal distribution of the splenic artery was studied in order to obtain anatomical basis for partial splenectomy. Thirty two spleens were studied, 26 spleens of healthy horses weighing 320 to 450 kg, aged 3 to 12 years and 6 spleens of fetus removed from slaughterhouse. The spleens were submitted to arteriography and scintigraphy in order to have their vascular pattern examined and compared to the external aspect of the organ aiming establish anatomo-surgical segments. All radiographs were photographed with a digital camera and the digital images were submitted to a measuring system for comparative analysis of areas of dorsal and ventral anatomo-surgical segments. Anatomical investigations into the angioarchitecture of the equine spleen showed a paucivascular area, which coincides with a thinner external area, allowing the organ to be divided in two anatomo-surgical segments of approximately 50% of the organ each.

  16. Horse spleen segmentation technique as large animal model of preclinical trials

    Directory of Open Access Journals (Sweden)

    Roberto P.P. Foz Filho

    2013-10-01

    Full Text Available The parenchymal distribution of the splenic artery was studied in order to obtain anatomical basis for partial splenectomy. Thirty two spleens were studied, 26 spleens of healthy horses weighing 320 to 450kg, aged 3 to 12 years and 6 spleens of fetus removed from slaughterhouse. The spleens were submitted to arteriography and scintigraphy in order to have their vascular pattern examined and compared to the external aspect of the organ aiming establish anatomo-surgical segments. All radiographs were photographed with a digital camera and the digital images were submitted to a measuring system for comparative analysis of areas of dorsal and ventral anatomo-surgical segments. Anatomical investigations into the angioarchitecture of the equine spleen showed a paucivascular area, which coincides with a thinner external area, allowing the organ to be divided in two anatomo-surgical segments of approximately 50% of the organ each.

  17. 3D Printed PEG-Based Hybrid Nanocomposites Obtained by Sol-Gel Technique.

    Science.gov (United States)

    Chiappone, Annalisa; Fantino, Erika; Roppolo, Ignazio; Lorusso, Massimo; Manfredi, Diego; Fino, Paolo; Pirri, Candido Fabrizio; Calignano, Flaviana

    2016-03-02

    In this work, three-dimensional (3D) structured hybrid materials were fabricated combining 3D printing technology with in situ generation of inorganic nanoparticles by sol-gel technique. Those materials, consisting of silica nanodomains covalently interconnected with organic polymers, were 3D printed in complex multilayered architectures, incorporating liquid silica precursors into a photocurable oligomer in the presence of suitable photoinitiators and exposing them to a digital light system. A post sol-gel treatment in acidic vapors allowed the in situ generation of the inorganic phase in a dedicated step. This method allows to build hybrid structures operating with a full liquid formulation without meeting the drawbacks of incorporating inorganic powders into 3D printable formulations. The influence of the generated silica nanoparticle on the printed objects was deeply investigated at macro- and nanoscale; the resulting light hybrid structures show improved mechanical properties and, thus, have a huge potential for applications in a variety of advanced technologies.

  18. Closure technique for the hybrid girder cable stayed bridge of Edong Bridge

    Institute of Scientific and Technical Information of China (English)

    Liu Minghu; Tan Hao; Xu GuoPing; Zhao Canhui

    2012-01-01

    Based on Edong Yangtze River Bridge, which is the second longest hybrid girder cable stayed bridge with 926 m long main span, the influencing factors and crucial techniques of the main span closure method for long span hybrid girder cable stayed bridge are studied. After theoretical analysis, numerical evaluation and practical test, the loading assistant closure method is employed in Edong Yangtze River Bridge. The loading assistant closure method, with better thermal adaptability and less influence on bridge line and the forced status, can meet the requirements of the unstressed state control method. Based on the mentioned advantages, the loading assistant closure method is applicable to long span hybrid girder cable stayed bridges. The conclusion can provide a reference for the further design of the similar brid~es.

  19. 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...... and analysed possible segments in the market. Results show that the statistical model used identified two segments - a segment of so-called "fish lovers" and another segment called "traditionalists". The "fish lovers" are very fond of eating fish and they actually prefer fish to other dishes...... 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...

  20. Automatic segmentation of airway tree based on local intensity filter and machine learning technique in 3D chest CT volume.

    Science.gov (United States)

    Meng, Qier; Kitasaka, Takayuki; Nimura, Yukitaka; Oda, Masahiro; Ueno, Junji; Mori, Kensaku

    2017-02-01

    Airway segmentation plays an important role in analyzing chest computed tomography (CT) volumes for computerized lung cancer detection, emphysema diagnosis and pre- and intra-operative bronchoscope navigation. However, obtaining a complete 3D airway tree structure from a CT volume is quite a challenging task. Several researchers have proposed automated airway segmentation algorithms basically based on region growing and machine learning techniques. However, these methods fail to detect the peripheral bronchial branches, which results in a large amount of leakage. This paper presents a novel approach for more accurate extraction of the complex airway tree. This proposed segmentation method is composed of three steps. First, Hessian analysis is utilized to enhance the tube-like structure in CT volumes; then, an adaptive multiscale cavity enhancement filter is employed to detect the cavity-like structure with different radii. In the second step, support vector machine learning will be utilized to remove the false positive (FP) regions from the result obtained in the previous step. Finally, the graph-cut algorithm is used to refine the candidate voxels to form an integrated airway tree. A test dataset including 50 standard-dose chest CT volumes was used for evaluating our proposed method. The average extraction rate was about 79.1 % with the significantly decreased FP rate. A new method of airway segmentation based on local intensity structure and machine learning technique was developed. The method was shown to be feasible for airway segmentation in a computer-aided diagnosis system for a lung and bronchoscope guidance system.

  1. A new hybrid jpeg image compression scheme using symbol reduction technique

    CERN Document Server

    Kumar, Bheshaj; Sinha, G R

    2012-01-01

    Lossy JPEG compression is a widely used compression technique. Normally the JPEG standard technique uses three process mapping reduces interpixel redundancy, quantization, which is lossy process and entropy encoding, which is considered lossless process. In this paper, a new technique has been proposed by combining the JPEG algorithm and Symbol Reduction Huffman technique for achieving more compression ratio. The symbols reduction technique reduces the number of symbols by combining together to form a new symbol. As a result of this technique the number of Huffman code to be generated also reduced. It is simple fast and easy to implement. The result shows that the performance of standard JPEG method can be improved by proposed method. This hybrid approach achieves about 20% more compression ratio than the Standard JPEG.

  2. Hybrid single-beam reconstruction technique for slow and fast varying wave fields.

    Science.gov (United States)

    Falaggis, Konstantinos; Kozacki, Tomasz; Kujawinska, Malgorzata

    2015-06-01

    An iterative single-beam wave field reconstruction technique that employs both non-paraxial, wave propagation based and paraxial deterministic phase retrieval techniques is presented. This approach overcomes two major obstacles that exist in the current state of the art techniques: iterative methods do not reconstruct slowly varying wave fields due to slow convergence and stagnation, and deterministic methods have paraxial limits, making the reconstructions of quickly varying object features impossible. In this work, a hybrid approach is reported that uses paraxial wave field corrections within iterative phase retrieval solvers. This technique is suitable for cases ranging from slow to fast varying wave fields, and unlike the currently available methods, can also reconstruct measurement objects with different regions of both slowly and quickly varying object features. It is further shown that this technique gives a higher accuracy than current single-beam phase retrieval techniques, and in comparison to the iterative methods, has a higher convergence speed.

  3. SEGMENTACIÓN DE FRUTOS DE CAFÉ MEDIANTE MÉTODOS DE CRECIMIENTO DE REGIONES SEGMENTATION OF COFFEE BEANS BY MEANS OF SEEDED REGION GROWING TECHNIQUES

    Directory of Open Access Journals (Sweden)

    Julián Andrés Betancur Acevedo

    2006-06-01

    Full Text Available Se presentan tres diferentes sistemas de segmentación los cuales utilizan la técnica de crecimiento de regiones a partir de semillas SRG (Seeded Region Growing. El primero de ellos, llamado Sistema Euclídeo, hace uso de la distancia euclídea con el fin de encontrar la región de interés (grano de café. El Sistema ACB-PCB utiliza dos medidas de discontinuidad llamadas contraste promedio y contraste periférico, las cuales se derivan del promedio de las componentes de color de los pıxeles que conforman la región y aquellos que conforman dos de sus contornos. Luego de un proceso iterativo, se halla el contorno de contraste promedio ACB y el contorno de contraste periférico PCB, que se usan para segmentar el grano de café. Por último, el Sistema Híbrido utiliza la información de las principales componentes geométricas presentes en la escena (dadas por un Detector de Bordes de Color, y la medida de contraste promedio. Las herramientas de segmentación fueron aplicadas a imágenes de frutos de café, adquiridas bajo condiciones controladas. Los resultados obtenidos muestran un buen desempeño del detector de bordes de color implementado, así como de los sistemas de segmentación, en especial de los sistemas ACB-PCB e Híbrido.Three segmentation systems are presented which use the Seeded Region Growing Technique SRG. The first one, called the Euclidean System, uses a Euclidean distance measure in order to find the region of interest (coffee bean. The ACB-PCB System uses two discontinuity measures called average contrast and peripheral contrast, which are derived from the mean of the color components of the pixels that form the region and those that form two of its boundaries. Following an iterative process, the Average Contrast Boundary ACB and the Peripheral Contrast Boundary PCB are computed for use in performing the coffee bean segmentation. Finally, the Hybrid System uses both information from the principal geometrical components in

  4. Sample preparation and in situ hybridization techniques for automated molecular cytogenetic analysis of white blood cells

    Energy Technology Data Exchange (ETDEWEB)

    Rijke, F.M. van de; Vrolijk, H.; Sloos, W. [Leiden Univ. (Netherlands)] [and others

    1996-06-01

    With the advent in situ hybridization techniques for the analysis of chromosome copy number or structure in interphase cells, the diagnostic and prognostic potential of cytogenetics has been augmented considerably. In theory, the strategies for detection of cytogenetically aberrant cells by in situ hybridization are simple and straightforward. In practice, however, they are fallible, because false classification of hybridization spot number or patterns occurs. When a decision has to be made on molecular cytogenetic normalcy or abnormalcy of a cell sample, the problem of false classification becomes particularly prominent if the fraction of aberrant cells is relatively small. In such mosaic situations, often > 200 cells have to be evaluated to reach a statistical sound figure. The manual enumeration of in situ hybridization spots in many cells in many patient samples is tedious. Assistance in the evaluation process by automation of microscope functions and image analysis techniques is, therefore, strongly indicated. Next to research and development of microscope hardware, camera technology, and image analysis, the optimization of the specimen for the (semi)automated microscopic analysis is essential, since factors such as cell density, thickness, and overlap have dramatic influences on the speed and complexity of the analysis process. Here we describe experiments that have led to a protocol for blood cell specimen that results in microscope preparations that are well suited for automated molecular cytogenetic analysis. 13 refs., 4 figs., 1 tab.

  5. Phase segmentation of X-ray computer tomography rock images using machine learning techniques: an accuracy and performance study

    Science.gov (United States)

    Chauhan, Swarup; Rühaak, Wolfram; Anbergen, Hauke; Kabdenov, Alen; Freise, Marcus; Wille, Thorsten; Sass, Ingo

    2016-07-01

    Performance and accuracy of machine learning techniques to segment rock grains, matrix and pore voxels from a 3-D volume of X-ray tomographic (XCT) grayscale rock images was evaluated. The segmentation and classification capability of unsupervised (k-means, fuzzy c-means, self-organized maps), supervised (artificial neural networks, least-squares support vector machines) and ensemble classifiers (bragging and boosting) were tested using XCT images of andesite volcanic rock, Berea sandstone, Rotliegend sandstone and a synthetic sample. The averaged porosity obtained for andesite (15.8 ± 2.5 %), Berea sandstone (16.3 ± 2.6 %), Rotliegend sandstone (13.4 ± 7.4 %) and the synthetic sample (48.3 ± 13.3 %) is in very good agreement with the respective laboratory measurement data and varies by a factor of 0.2. The k-means algorithm is the fastest of all machine learning algorithms, whereas a least-squares support vector machine is the most computationally expensive. Metrics entropy, purity, mean square root error, receiver operational characteristic curve and 10 K-fold cross-validation were used to determine the accuracy of unsupervised, supervised and ensemble classifier techniques. In general, the accuracy was found to be largely affected by the feature vector selection scheme. As it is always a trade-off between performance and accuracy, it is difficult to isolate one particular machine learning algorithm which is best suited for the complex phase segmentation problem. Therefore, our investigation provides parameters that can help in selecting the appropriate machine learning techniques for phase segmentation.

  6. Biomechanical comparison of interference screw and cortical button with screw hybrid technique for distal biceps brachii tendon repair.

    Science.gov (United States)

    Arianjam, Afshin; Camisa, William; Leasure, Jeremi M; Montgomery, William H

    2013-11-01

    Various fixation techniques have been described for ruptured distal biceps tendons. The authors hypothesized that no significant differences would be found between the mean failure strength, maximum strength, and stiffness of the interference screw and hybrid technique. Fourteen fresh-frozen human cadaveric elbows were prepared. Specimens were randomized to either interference screw or hybrid cortical button with screw fixation. The tendon was pulled at a rate of 4 mm/s until failure. Failure strength, maximum strength, and stiffness were measured and compared. Failure strength, maximum strength, and stiffness were 294±81.9 N, 294±82.1 N, and 64.4±40.5 N/mm, respectively, for the interference screw technique and 333±129 N, 383±121 N, and 56.2±40.5 N/mm, respectively, for the hybrid technique. No statistically significant difference existed between the screw and hybrid technique in failure strength, maximum strength, or stiffness (P>.05). The interference screws primarily failed by pullout of the screw and tendon, whereas in the hybrid technique, failure occurred with screw pullout followed by tearing of the biceps tendon. The results suggest that this hybrid technique is nearly as strong and stiff as the interference screw alone. Although the hybrid technique facilitates tensioning of the reconstructed tendon, the addition of the cortical button did not significantly improve the failure strength of the interference screw alone. Copyright 2013, SLACK Incorporated.

  7. A DG Implementation of a Novel Hybrid RANS/LES Technique With RANS Reconstruction

    CERN Document Server

    Abbà, Antonella; Nini, Michele; Restelli, Marco

    2014-01-01

    A new hybrid RANS/LES technique, based on the hybrid filter proposed by Germano in 2004, has been studied. The novelty herein introduced is represented by the reconstruction of the Reynolds stress tensor. As a consequence, no explicit RANS model is needed. The RANS and LES terms are merged using a constant blending factor. The model is implemented in a numerical code based on a high order Discontinuous Galerkin (DG) finite element formulation. The test case considered for numerical simulations is the turbulent tur- bulent channel flow at Mach = 0.2. The comparison with available DNS data shows a good agreement and, in general, an improvement with re- spect to pure LES results, confirming that the technique herein proposed represents a promising approach to the numerical simulation of turbulent flows.

  8. Manual-protocol inspired technique for improving automated MR image segmentation during label-fusion

    Directory of Open Access Journals (Sweden)

    Nikhil Bhagwat

    2016-07-01

    Full Text Available Recent advances in multi-atlas based algorithms address many of the previous limitations in model-based and probabilistic segmentation methods. However, at the label fusion stage, a majority of algorithms focus primarily on optimizing weight-maps associated with the atlas library based on a theoretical objective function that approximates the segmentation error. In contrast, we propose a novel method - Autocorrecting Walks over Localized Markov Random Fields (AWoL-MRF - that aims at mimicking the sequential process of manual segmentation, which is the gold-standard for virtually all the segmentation methods. AWoL-MRF begins with a set of candidate labels generated by a multi-atlas segmentation pipeline as an initial label distribution and refines low confidence regions based on a localized Markov random field (L-MRF model using a novel sequential inference process (walks. We show that AWoL-MRF produces state-of-the-art results with superior accuracy and robustness with a small atlas library compared to existing methods. We validate the proposed approach by performing hippocampal segmentations on three independent datasets: 1 Alzheimer’s Disease Neuroimaging Database (ADNI; 2 First Episode Psychosis patient cohort; and 3 A cohort of preterm neonates scanned early in life and at term-equivalent age. We assess the improvement in the performance qualitatively as well as quantitatively by comparing AWoL-MRF with majority vote, STAPLE, and Joint Label Fusion methods. AWoL-MRF reaches a maximum accuracy of 0.881 (dataset 1, 0.897 (dataset 2, and 0.807 (dataset 3 based on Dice similarity coefficient metric, offering significant performance improvements with a smaller atlas library (<10 over compared methods. We also evaluate the diagnostic utility of AWoL-MRF by analyzing the volume differences per disease category in the ADNI1: Complete Screening dataset. We have made the source code for AWoL-MRF public at: https://github.com/CobraLab/AWoL-MRF.

  9. Detection of chromosome aberrations in interphase nuclei using fluorescence in situ hybridization technique.

    OpenAIRE

    1993-01-01

    We report here several experiences of interphase cytogenetics, using fluorescence in situ hybridization (FISH) technique, for the detection of chromosome aberrations. FISH, using alpha satellite specific probes of 18, X, Y chromosomes, was done in interphase nuclei from peripheral blood of patients with Edwards' syndrome, Klinefelter's syndrome and Turner's syndrome with healthy male and female controls, respectively. The distributions of fluorescent signals in 100 interphase nuclei were well...

  10. Parenchyma-wise technique for the harvest and implantation of hepatic segment 2-3 grafts: Anatomic basis and surgical steps.

    Science.gov (United States)

    El Gharbawy, Ramadan M; Skandalakis, Lee J; Heffron, Thomas G; Skandalakis, John E

    2011-09-01

    We propose a technique for pediatric liver transplantation that does not waste the donor's parenchyma. Organ shortage has extended criteria for donor acceptance, such that even individuals with livers of suboptimal volume can donate their segment 2-3. By incorporating wise use of parenchyma, our proposed technique for harvesting segment 2-3 for implantation in a pediatric recipient benefits these and other donors, and it might increase donations. This is especially important in countries in which procurement of organs from the deceased is not allowed. Our technique also aims to solve the problem of the large-for-size syndrome for neonates and extremely small infants and to allow for primary closure of the abdomen. This technique enables harvest of the following four grafts: (1) complete segment 2-3; (2) reduced segment 2-3; (3) complete segment 3; and (4) reduced segment 3. The surgeon will select the type that has suitable graft-to-recipient weight ratio and that suits the donor's liver anatomy and volume. These four types benefit the donor by preserving the parenchyma of segment 4 and the left part of the caudate lobe. The three graft types other than the complete segment 2-3 graft will also preserve varying fractions of the parenchyma of segment 2-3. The technique for complete segment 2-3 graft can be put into practice immediately; the techniques for the other three grafts need an imaging modality to preoperatively delineate the donor's fourth-order bile ducts. We expect to correct this deficiency in the near future by developing the requisite imaging technique.

  11. Modified watershed technique and post-processing for segmentation of skin lesions in dermoscopy images.

    Science.gov (United States)

    Wang, Hanzheng; Moss, Randy H; Chen, Xiaohe; Stanley, R Joe; Stoecker, William V; Celebi, M Emre; Malters, Joseph M; Grichnik, James M; Marghoob, Ashfaq A; Rabinovitz, Harold S; Menzies, Scott W; Szalapski, Thomas M

    2011-03-01

    In previous research, a watershed-based algorithm was shown to be useful for automatic lesion segmentation in dermoscopy images, and was tested on a set of 100 benign and malignant melanoma images with the average of three sets of dermatologist-drawn borders used as the ground truth, resulting in an overall error of 15.98%. In this study, to reduce the border detection errors, a neural network classifier was utilized to improve the first-pass watershed segmentation; a novel "edge object value (EOV) threshold" method was used to remove large light blobs near the lesion boundary; and a noise removal procedure was applied to reduce the peninsula-shaped false-positive areas. As a result, an overall error of 11.09% was achieved.

  12. A low-loss hybrid rectification technique for piezoelectric energy harvesting

    Science.gov (United States)

    Schlichting, A. D.; Fink, E.; Garcia, E.

    2013-09-01

    Embedded systems have decreased in size and increased in capability; however, small-scale energy storage technologies still significantly limit these advances. Energy neutral operation using small-scale energy harvesting technologies would allow for longer device operation times and smaller energy storage masses. Vibration energy harvesting is an attractive method due to the prevalence of energy sources in many environments. Losses in efficiency due to AC-DC rectification and conditioning circuits limit its application. This work presents a low-loss hybrid rectification technique for piezoelectric vibration energy harvesting using magnetically actuated reed switches and a passive semiconductor full-bridge rectifier. This method shows the capability to have higher efficiency levels and the rectification of low-voltage harvesters without the need for active electrical components. A theoretical model shows that the hybrid rectification technique performance is highly dependent on the proximity delay and the hysteresis behavior of the reed switches. Experimental results validate the model and support the hypothesis of increased performance using the hybrid rectification technique.

  13. A Comparison of Redundancy Techniques for Private and Hybrid Cloud Storage

    Directory of Open Access Journals (Sweden)

    E.M. Hernandez-Ramirez

    2012-11-01

    Full Text Available File redundancy techniques have been very useful mechanisms for offering fault tolerance and data availability in anykind of storage. Cloud storage is not the exception. This paper presents an evaluation of classical file redundancytechniques implemented in two cloud-storage deployment models, private and hybrid. A small prototype of a privateand hybrid cloud storage was implemented for this evaluation. The performance impact when file redundancy is onlyapplied in a private cloud versus when redundancy is also distributed in a public cloud (the hybrid model is analyzed.Additional to classical file redundancy techniques, an innovative method was evaluated for file redundancy based onan information dispersal algorithm (IDA. The usage of IDA represents a good option for managing sensitive data inhybrid cloud storage. In this technique, only parts of a file need to be sent to the public cloud, avoiding the completefile to be read from outside of the private zone. In this context, there is a trade-off between performance (forreconstructing the original file, it is first necessary to obtain all of its fragments and the security level that coulddetermine the viability of using IDA.

  14. Horse spleen segmentation technique as large animal model of preclinical trials

    OpenAIRE

    Foz Filho, Roberto P. P.; Martin, Benedito W. de; Ana Rita De Lima; Maria Angelica Miglino

    2013-01-01

    The parenchymal distribution of the splenic artery was studied in order to obtain anatomical basis for partial splenectomy. Thirty two spleens were studied, 26 spleens of healthy horses weighing 320 to 450kg, aged 3 to 12 years and 6 spleens of fetus removed from slaughterhouse. The spleens were submitted to arteriography and scintigraphy in order to have their vascular pattern examined and compared to the external aspect of the organ aiming establish anatomo-surgical segments. All radiograph...

  15. An Improved Character Segmentation Algorithm Based on Local Adaptive Thresholding Technique for Chinese NvShu Documents

    Directory of Open Access Journals (Sweden)

    Yangguang Sun

    2014-06-01

    Full Text Available For the structural characteristics of Chinese NvShu character, by combining the basic idea in LLT local threshold algorithm and introducing the maximal between-class variance algorithm into local windows, an improved character segmentation algorithm based on local adaptive thresholding technique for Chinese NvShu documents was presented in this paper. Because of designing the corresponding correction parameters for the threshold and using secondary search mechanism, our proposed method could not only automatically obtain local threshold, but also avoid the loss of the character image information and improve the accuracy of the character image segmentation. Experimental results demonstrated its capability to reduce the effect of background noise, especially for Chinese NvShu character images with uneven illumination and low contrast

  16. ACM-based automatic liver segmentation from 3-D CT images by combining multiple atlases and improved mean-shift techniques.

    Science.gov (United States)

    Ji, Hongwei; He, Jiangping; Yang, Xin; Deklerck, Rudi; Cornelis, Jan

    2013-05-01

    In this paper, we present an autocontext model(ACM)-based automatic liver segmentation algorithm, which combines ACM, multiatlases, and mean-shift techniques to segment liver from 3-D CT images. Our algorithm is a learning-based method and can be divided into two stages. At the first stage, i.e., the training stage, ACM is performed to learn a sequence of classifiers in each atlas space (based on each atlas and other aligned atlases). With the use of multiple atlases, multiple sequences of ACM-based classifiers are obtained. At the second stage, i.e., the segmentation stage, the test image will be segmented in each atlas space by applying each sequence of ACM-based classifiers. The final segmentation result will be obtained by fusing segmentation results from all atlas spaces via a multiclassifier fusion technique. Specially, in order to speed up segmentation, given a test image, we first use an improved mean-shift algorithm to perform over-segmentation and then implement the region-based image labeling instead of the original inefficient pixel-based image labeling. The proposed method is evaluated on the datasets of MICCAI 2007 liver segmentation challenge. The experimental results show that the average volume overlap error and the average surface distance achieved by our method are 8.3% and 1.5 m, respectively, which are comparable to the results reported in the existing state-of-the-art work on liver segmentation.

  17. Segmentation of 3D microPET images of the rat brain via the hybrid gaussian mixture method with kernel density estimation.

    Science.gov (United States)

    Chen, Tai-Been; Chen, Jyh-Cheng; Lu, Henry Horng-Shing

    2012-01-01

    Segmentation of positron emission tomography (PET) is typically achieved using the K-Means method or other approaches. In preclinical and clinical applications, the K-Means method needs a prior estimation of parameters such as the number of clusters and appropriate initialized values. This work segments microPET images using a hybrid method combining the Gaussian mixture model (GMM) with kernel density estimation. Segmentation is crucial to registration of disordered 2-deoxy-2-fluoro-D-glucose (FDG) accumulation locations with functional diagnosis and to estimate standardized uptake values (SUVs) of region of interests (ROIs) in PET images. Therefore, simulation studies are conducted to apply spherical targets to evaluate segmentation accuracy based on Tanimoto's definition of similarity. The proposed method generates a higher degree of similarity than the K-Means method. The PET images of a rat brain are used to compare the segmented shape and area of the cerebral cortex by the K-Means method and the proposed method by volume rendering. The proposed method provides clearer and more detailed activity structures of an FDG accumulation location in the cerebral cortex than those by the K-Means method.

  18. High capacity fiber optic sensor networks using hybrid multiplexing techniques and their applications

    Science.gov (United States)

    Sun, Qizhen; Li, Xiaolei; Zhang, Manliang; Liu, Qi; Liu, Hai; Liu, Deming

    2013-12-01

    Fiber optic sensor network is the development trend of fiber senor technologies and industries. In this paper, I will discuss recent research progress on high capacity fiber sensor networks with hybrid multiplexing techniques and their applications in the fields of security monitoring, environment monitoring, Smart eHome, etc. Firstly, I will present the architecture of hybrid multiplexing sensor passive optical network (HSPON), and the key technologies for integrated access and intelligent management of massive fiber sensor units. Two typical hybrid WDM/TDM fiber sensor networks for perimeter intrusion monitor and cultural relics security are introduced. Secondly, we propose the concept of "Microstructure-Optical X Domin Refecltor (M-OXDR)" for fiber sensor network expansion. By fabricating smart micro-structures with the ability of multidimensional encoded and low insertion loss along the fiber, the fiber sensor network of simple structure and huge capacity more than one thousand could be achieved. Assisted by the WDM/TDM and WDM/FDM decoding methods respectively, we built the verification systems for long-haul and real-time temperature sensing. Finally, I will show the high capacity and flexible fiber sensor network with IPv6 protocol based hybrid fiber/wireless access. By developing the fiber optic sensor with embedded IPv6 protocol conversion module and IPv6 router, huge amounts of fiber optic sensor nodes can be uniquely addressed. Meanwhile, various sensing information could be integrated and accessed to the Next Generation Internet.

  19. A HYBRID TECHNIQUE FOR FREQUENCY DOMAIN IDENTIFICATION OF SERVO SYSTEM WITH FRICTION FORCE

    Directory of Open Access Journals (Sweden)

    SHAIK.RAFI KIRAN,

    2011-03-01

    Full Text Available The system identification process in servo system with frictional force seems to be a complex task becauseof its non-linear nature. For such non-linear systems, a good choice is system identification in frequencydomain. However, most of the techniques are manual and are inappropriate for determination of systemparameters. This makes system identification ineffective for servo systems with frictional force. Toovercome this issue, a hybrid technique is proposed in this paper. The proposed technique exploits neuralnetwork and genetic algorithm to determine the system parameters of servo systems with friction. In theproposed technique, the target parameters are determined from the transfer function derived for thesystem. Subsequently, the system parameters are identified by a process formed by blending the neuralnetwork and genetic algorithm techniques. Prior to performing the identification procedure, backpropagation training is given to the neural network using a pre-examined dataset. Then with thecombined operation of neural network and genetic algorithm, the system parameters that are closer tothe target parameters for the servo system with frictional force are determined. The technique isimplemented and compared with the existing frequency domain identification technique. From thecomparative results, it is evident that the proposed technique outperforms the existing technique.

  20. An improved brain image classification technique with mining and shape prior segmentation procedure.

    Science.gov (United States)

    Rajendran, P; Madheswaran, M

    2012-04-01

    The shape prior segmentation procedure and pruned association rule with ImageApriori algorithm has been used to develop an improved brain image classification system are presented in this paper. The CT scan brain images have been classified into three categories namely normal, benign and malignant, considering the low-level features extracted from the images and high level knowledge from specialists to enhance the accuracy in decision process. The experimental results on pre-diagnosed brain images showed 97% sensitivity, 91% specificity and 98.5% accuracy. The proposed algorithm is expected to assist the physicians for efficient classification with multiple key features per image.

  1. Muscle gap approach under a minimally invasive channel technique for treating long segmental lumbar spinal stenosis: A retrospective study.

    Science.gov (United States)

    Bin, Yang; De Cheng, Wang; Wei, Wang Zong; Hui, Li

    2017-08-01

    This study aimed to compare the efficacy of muscle gap approach under a minimally invasive channel surgical technique with the traditional median approach.In the Orthopedics Department of Traditional Chinese and Western Medicine Hospital, Tongzhou District, Beijing, 68 cases of lumbar spinal canal stenosis underwent surgery using the muscle gap approach under a minimally invasive channel technique and a median approach between September 2013 and February 2016. Both approaches adopted lumbar spinal canal decompression, intervertebral disk removal, cage implantation, and pedicle screw fixation. The operation time, bleeding volume, postoperative drainage volume, and preoperative and postoperative visual analog scale (VAS) score and Japanese Orthopedics Association score (JOA) were compared between the 2 groups.All patients were followed up for more than 1 year. No significant difference between the 2 groups was found with respect to age, gender, surgical segments. No diversity was noted in the operation time, intraoperative bleeding volume, preoperative and 1 month after the operation VAS score, preoperative and 1 month after the operation JOA score, and 6 months after the operation JOA score between 2 groups (P > .05). The amount of postoperative wound drainage (260.90 ± 160 mL vs 447.80 ± 183.60 mL, P gap approach group than in the median approach group (P gap approach under a minimally invasive channel group, the average drainage volume was reduced by 187 mL, and the average VAS score 6 months after the operation was reduced by an average of 0.48.The muscle gap approach under a minimally invasive channel technique is a feasible method to treat long segmental lumbar spinal canal stenosis. It retains the integrity of the posterior spine complex to the greatest extent, so as to reduce the adjacent spinal segmental degeneration and soft tissue trauma. Satisfactory short-term and long-term clinical results were obtained.

  2. Model of Appling Data Mining Techniques in identification, segmentation and Analysis of Customers Behaviour of Electronic Banking Services

    Directory of Open Access Journals (Sweden)

    Mohammad Khanbabaei

    2013-09-01

    Full Text Available Banks need to identify and analyze the behavior of their customers in order to present electorinc services to them. In high volume customers' data set, data mining techniques can help to gain hidden knowledge for supporting marketing decisions. The main problem is how using data mining and RFM analysis model in identification and analysis of customers' behavior in order to segment and classify and select groups of valuable customers. The proposed model in this paper is based on CRISP – DM standard in data mining and in this model, after data preparation and preprocessing, two approaches are presented. 1. Customers segmentation via clustering and then, calculate customer value in clusters and ranking them for finding valuable clusters. 2. Scoring and determine customer value as target attribute in construction of classification models of customers value. Demographic and transactional data set are used to train and test of the proposed model. Results shows using the proposed model can identify and analyze customers with respect to their behaviors and segment and classify them until supporting and promoting marketing decisions can be done.

  3. Contrast-Enhanced MR Angiography (CEMRA) in Peripheral Arterial Occlusive Disease (PAOD): conventional moving table technique versus hybrid technique; Kontrastverstaerkte MR-Angiographie (CEMRA) bei peripherer AVK (pAVK): konventionelle Tischverschiebetechnik versus Hybrid-Technik

    Energy Technology Data Exchange (ETDEWEB)

    Kalle, T. von; Gerlach, A.; Hatopp, A.; Klinger, S.; Prodehl, P.; Arlat, I.P. [Katharinenhospital, Stuttgart (Germany). Radiologisches Inst.

    2004-01-01

    Patients and Methods: 80 patients (males n = 60, females n = 20, median age = 70 years, diabetics n = 27) with PAOD were examined with a 1,5T system (40 mT/m) using a dedicated phased array peripheral vascular coil. Protocol A consisted of a single injection of Gd-BOPTA with consecutive craniocaudal image acquisition and protocol B of two injections, with the first injection of Gd-BOPTA followed by image acquisition of the popliteocrural and pedal segments and the second injection followed by acquiring the aortoiliac and femoral segments (hybrid technique). The evaluation of the arterial system was directed to the iliac, femoral, popliteocrural and pedal arteries. Results: The visualization of the entire aortopedal vascular system was of diagnostically good or satisfactory quality in 16 of 40 patients using protocol A and in 29 of 40 patients using protocol B (iliac 40 vs. 37, femoral 40 vs. 40, popliteocrural 35 vs. 37, pedal 16 vs. 29); without the pedal station the number increased to 35 of 40 patients for both protocols. The reason of diagnostic limitations was an arteriovenous overlap in 24 of 80 cases, with 19 of 40 cases for protocol A and 5 of 40 for protocol B, located exclusively in the cruropedal region. Conclusion: Moving table hybrid CEMRA is superior to conventional technique in craniocaudal direction by producing less venous overlap of arteries and is especially more suitable for the diagnostic evaluation of the cruropedal region. (orig.) [German] Patienten und Methodik: Untersucht wurden 80 Patienten (maennl. n = 60, weibl. n = 20, mittl. Alter 70 J., Diabetiker n = 27) mit pAVK an einem 1,5-Tesla-Geraet (40 mT/m) mit dedizierter Phased-Array-Oberflaechen-Gefaessspule. Protokoll A beinhaltete eine Kontrastmittel-Injektion (Gd-BOPTA) mit konsekutiver kraniokaudaler Bildakquisition. In Protokoll B erfolgte die Akquisition zunaechst der Unterschenkel- und Fussetage mittels einer ersten, anschliessend der Abdomen-Becken- und Oberschenkeletage mittels

  4. Two additional augmenting screws with posterior short-segment instrumentation without fusion for unstable thoracolumbar burst fracture – Comparisons with transpedicular grafting techniques

    Directory of Open Access Journals (Sweden)

    Yu-Chih Lin

    2016-12-01

    Conclusions: Compared with transpedicular grafting techniques, additional two “augmenting screws” in the fracture vertebra with short-segment instrumentation are sufficient for one-level thoracolumbar burst fracture.

  5. Recent Developments on Hybrid Time-Frequency Numerical Simulation Techniques for RF and Microwave Applications

    Directory of Open Access Journals (Sweden)

    Jorge F. Oliveira

    2013-01-01

    Full Text Available This paper reviews some of the promising doors that functional analysis techniques have recently opened in the field of electronic circuit simulation. Because of the modulated nature of radio frequency (RF signals, the corresponding electronic circuits seem to operate in a slow time scale for the aperiodic information and another, much faster, time scale for the periodic carrier. This apparent multirate behavior can be appropriately described using partial differential equations (PDEs within a bivariate framework, which can be solved in an efficient way using hybrid time-frequency techniques. With these techniques, the aperiodic information dimension is treated in the discrete time domain, while the periodic carrier dimension is processed in the frequency domain, in which the solution is evaluated within a space of harmonically related sinusoidal functions. The objective of this paper is thus to provide a general overview on the most important hybrid time-frequency techniques, as the ones found in commercial tools or the ones recently published in the literature.

  6. CT and MRI assessment and characterization using segmentation and 3D modeling techniques: applications to muscle, bone and brain

    Directory of Open Access Journals (Sweden)

    Paolo Gargiulo

    2014-03-01

    Full Text Available This paper reviews the novel use of CT and MRI data and image processing tools to segment and reconstruct tissue images in 3D to determine characteristics of muscle, bone and brain.This to study and simulate the structural changes occurring in healthy and pathological conditions as well as in response to clinical treatments. Here we report the application of this methodology to evaluate and quantify: 1. progression of atrophy in human muscle subsequent to permanent lower motor neuron (LMN denervation, 2. muscle recovery as induced by functional electrical stimulation (FES, 3. bone quality in patients undergoing total hip replacement and 4. to model the electrical activity of the brain. Study 1: CT data and segmentation techniques were used to quantify changes in muscle density and composition by associating the Hounsfield unit values of muscle, adipose and fibrous connective tissue with different colors. This method was employed to monitor patients who have permanent muscle LMN denervation in the lower extremities under two different conditions: permanent LMN denervated not electrically stimulated and stimulated. Study 2: CT data and segmentation techniques were employed, however, in this work we assessed bone and muscle conditions in the pre-operative CT scans of patients scheduled to undergo total hip replacement. In this work, the overall anatomical structure, the bone mineral density (BMD and compactness of quadriceps muscles and proximal femoral was computed to provide a more complete view for surgeons when deciding which implant technology to use. Further, a Finite element analysis provided a map of the strains around the proximal femur socket when solicited by typical stresses caused by an implant press fitting. Study 3 describes a method to model the electrical behavior of human brain using segmented MR images. The aim of the work is to use these models to predict the electrical activity of the human brain under normal and pathological

  7. CT and MRI Assessment and Characterization Using Segmentation and 3D Modeling Techniques: Applications to Muscle, Bone and Brain

    Science.gov (United States)

    Helgason, Thordur; Ramon, Ceon; jr, Halldór Jónsson; Carraro, Ugo

    2014-01-01

    This paper reviews the novel use of CT and MRI data and image processing tools to segment and reconstruct tissue images in 3D to determine characteristics of muscle, bone and brain. This to study and simulate the structural changes occurring in healthy and pathological conditions as well as in response to clinical treatments. Here we report the application of this methodology to evaluate and quantify: 1. progression of atrophy in human muscle subsequent to permanent lower motor neuron (LMN) denervation, 2. muscle recovery as induced by functional electrical stimulation (FES), 3. bone quality in patients undergoing total hip replacement and 4. to model the electrical activity of the brain. Study 1: CT data and segmentation techniques were used to quantify changes in muscle density and composition by associating the Hounsfield unit values of muscle, adipose and fibrous connective tissue with different colors. This method was employed to monitor patients who have permanent muscle LMN denervation in the lower extremities under two different conditions: permanent LMN denervated not electrically stimulated and stimulated. Study 2: CT data and segmentation techniques were employed, however, in this work we assessed bone and muscle conditions in the pre-operative CT scans of patients scheduled to undergo total hip replacement. In this work, the overall anatomical structure, the bone mineral density (BMD) and compactness of quadriceps muscles and proximal femoral was computed to provide a more complete view for surgeons when deciding which implant technology to use. Further, a Finite element analysis provided a map of the strains around the proximal femur socket when solicited by typical stresses caused by an implant press fitting. Study 3 describes a method to model the electrical behavior of human brain using segmented MR images. The aim of the work is to use these models to predict the electrical activity of the human brain under normal and pathological conditions by

  8. Hybrid machine learning technique for forecasting Dhaka stock market timing decisions.

    Science.gov (United States)

    Banik, Shipra; Khodadad Khan, A F M; Anwer, Mohammad

    2014-01-01

    Forecasting stock market has been a difficult job for applied researchers owing to nature of facts which is very noisy and time varying. However, this hypothesis has been featured by several empirical experiential studies and a number of researchers have efficiently applied machine learning techniques to forecast stock market. This paper studied stock prediction for the use of investors. It is always true that investors typically obtain loss because of uncertain investment purposes and unsighted assets. This paper proposes a rough set model, a neural network model, and a hybrid neural network and rough set model to find optimal buy and sell of a share on Dhaka stock exchange. Investigational findings demonstrate that our proposed hybrid model has higher precision than the single rough set model and the neural network model. We believe this paper findings will help stock investors to decide about optimal buy and/or sell time on Dhaka stock exchange.

  9. Step Response Enhancement of Hybrid Stepper Motors Using Soft Computing Techniques

    Directory of Open Access Journals (Sweden)

    Amged S. El-Wakeel

    2014-05-01

    Full Text Available This paper presents the use of different soft computing techniques for step response enhancement of Hybrid Stepper Motors. The basic differential equations of hybrid stepper motor are used to build up a model using MATLAB software package. The implementation of Fuzzy Logic (FL and Proportional-Integral-Derivative (PID controllers are used to improve the motor performance. The numerical simulations by a PC-based controller show that the PID controller tuned by Genetic Algorithm (GA produces better performance than that tuned by Fuzzy controller. They show that, the Fuzzy PID-like controller produces better performance than the other linear Fuzzy controllers. Finally, the comparison between PID controllers tuned by genetic algorithm and the Fuzzy PID-like controller shows that, the Fuzzy PID-like controller produces better performance.

  10. Segmental sandwich osteotomy and tunnel technique for three-dimensional reconstruction of the jaw atrophy: a case report.

    Science.gov (United States)

    Santagata, Mario; Sgaramella, Nicola; Ferrieri, Ivo; Corvo, Giovanni; Tartaro, Gianpaolo; D'Amato, Salvatore

    2017-12-01

    A three-dimensionally favourable mandibular bone crest is desirable to be able to successfully implant placement to meet the aesthetic and functional criteria in the implant-prosthetic rehabilitation. Several surgical procedures have been advocated for bone augmentation of the atrophic mandible, and the sandwich osteotomy is one of these techniques. The aim of the present case report was to assess the suitability of segmental mandibular sandwich osteotomy combined with a tunnel technique of soft tissue. Based on our knowledge, nobody described before the sandwich osteotomy with tunnel technique to improve the healing of the wound and meet the dimensional requirements of preimplant bone augmentation in cases of a severely atrophic mandible. A 59-year-old woman with a severely atrophied right mandible was treated with the sandwich osteotomy technique filled with autologous bone graft harvested by a cortical bone collector from the ramus. Clinical examination revealed that the mandible was edentulous bilaterally from the first molar to the second molar region. Radiographically, atrophy of the mandibular alveolar ridge in the same teeth site was observed. We began to treat the right side. A horizontal osteotomy of the edentulous mandibular bone was then made with a piezoelectric device after tunnel technique of the soft tissue. The segmental mandibular sandwich osteotomy (SMSO) was finished by two (mesial and distal) slightly divergent vertical osteotomies. The entire bone fragment was displaced cranially, and the desirable position was obtained. The gap was filled completely with autologous bone chips harvested from the mandibular ramus through a cortical bone collector. No barrier membranes were used to protect the grafts. The vertical incisions were closing with interruptive suturing of the flaps with a resorbable material. In this way, the suture will not fall on the osteotomy line of the jaw; the result will be a better predictability of soft and hard tissue

  11. Integration of Morphology and Graph-based Techniques for Fully Automatic Liver Segmentation

    Directory of Open Access Journals (Sweden)

    Hans Burkhardt

    2010-09-01

    Full Text Available Here a fully 3D algorithm for automatic liver segmentation from CT volumetric datasets is presented. The algorithm starts by smoothing the original volume using anisotropic diffusion. The coarse liver region is obtained from the threshold process that is based on a priori knowledge. Then, several morphological operations is performed such as operating the liver to detach the unwanted region connected to the liver and finding the largest component using the connected component labeling (CCL algorithm. At this stage, both 3D and 2D CCL is done subsequently. However, in 2D CCL, the adjacent slices are also affected from current slice changes. Finally, the boundary of the liver is refined using graph-cuts solver. Our algorithm does not require any user interaction or training datasets to be used. The algorithm has been evaluated on 10 CT scans of the liver and the results are encouraging to poor quality of images.

  12. Calibrating apodizer fabrication techniques for high-contrast coronagraphs on segmented and monolithic space telescopes

    Science.gov (United States)

    Sivaramakrishnan, Anand; Greenbaum, Alexandra Z.; Carr, G. Lawrence; Smith, Randy J.; Xi, Xiaoxiang; Zimmerman, Neil T.

    2013-09-01

    High contrast imaging can use pupil apodizers to suppress diffracted starlight from a bright source in order to observe its environs. Metallic half-tone dot transmissive apodizers were developed for the Gemini Planet Imager (GPI) and ESO SPHERE coronagraphs for use in the near-IR. Dot sizes on the scale of the wavelength of the light often result in unexpected variations in the optical transmission vs. superficial dot density relation. We measured 5 and 10 micron half-tone microdot screens' transmissions between 550 -1050 nm to prepare to fabricate apodizations that mitigate diffraction by segments gaps and spiders on future large space telescopes. We utilized slow test beams (f/40, f/80) to estimate the on-axis (far-field, or zero-order) transmission of test patches using a Fourier Transform Spectrograph on Beamline U10B at Brookhaven National Laboratory's National Synchrotron Light Source (BNL NSLS). We also modified our previous GPI IR characterization hardware and methods for this experiment. Our measurements show an internal consistency of 0.1% in transmission, a factor of 5 better than our near-IR GPI work on the NSLS U4IR beamline. The systematics of the set-up appeared to limit the absolute calibration for our f/40 data on the 50-patch, maximum Optical Density 3 (OD3), sample. Credible measurements of transmissions down to about 3% transmission were achieved for this sample. Future work on apodizers for obstructed and segmented primary mirror coronagraphs will require configurations that mimic the intended diffractive configurations closely in order to tune apodizer fabrication to any particular application, and measure chromatic effects in representative diffractive regimes. Further experimental refinements are needed to measure the densest test patches which possess transmissions less than a few percent. The new NSLS-II should provide much greater spectral stability of its synchrotron beam, which will improve measurement accuracy and reduce systematics.

  13. Hybrid PIV-PTV technique for measuring blood flow in rat mesenteric vessels.

    Science.gov (United States)

    Ha, Hojin; Nam, Kweon-Ho; Lee, Sang Joon

    2012-11-01

    The micro-particle tracking velocimetry (μ-PTV) technique is used to obtain the velocity fields of blood flow in the microvasculature under in vivo conditions because it can provide the blood velocity distribution in microvessels with high spatial resolution. The in vivo μ-PTV technique usually requires a few to tens of seconds to obtain a whole velocity profile across the vessel diameter because of the limited number density of tracer particles under in vivo conditions. Thus, the μ-PTV technique alone is limited in measuring unsteady blood flows that fluctuate irregularly due to the heart beating and muscle movement in surrounding tissues. In this study, a new hybrid PIV-PTV technique was established by combining PTV and particle image velocimetry (PIV) techniques to resolve the drawbacks of the μ-PTV method in measuring blood flow in microvessels under in vivo conditions. Images of red blood cells (RBCs) and fluorescent particles in rat mesenteric vessels were obtained simultaneously. Temporal variations of the centerline blood velocity were monitored using a fast Fourier transform-based cross-correlation PIV method. The fluorescence particle images were analyzed using the μ-PTV technique to extract the spatial distribution of the velocity vectors. Data from the μ-PTV and PIV methods were combined to obtain a better estimate of the velocity profile in actual blood flow. This technique will be useful in investigating hemodynamics in microcirculation by measuring unsteady irregular blood flows more accurately.

  14. A Low Cost Vision Based Hybrid Fiducial Mark Tracking Technique for Mobile Industrial Robots

    Directory of Open Access Journals (Sweden)

    Mohammed Y Aalsalem

    2012-07-01

    Full Text Available The field of robotic vision is developing rapidly. Robots can react intelligently and provide assistance to user activities through sentient computing. Since industrial applications pose complex requirements that cannot be handled by humans, an efficient low cost and robust technique is required for the tracking of mobile industrial robots. The existing sensor based techniques for mobile robot tracking are expensive and complex to deploy, configure and maintain. Also some of them demand dedicated and often expensive hardware. This paper presents a low cost vision based technique called “Hybrid Fiducial Mark Tracking” (HFMT technique for tracking mobile industrial robot. HFMT technique requires off-the-shelf hardware (CCD cameras and printable 2-D circular marks used as fiducials for tracking a mobile industrial robot on a pre-defined path. This proposed technique allows the robot to track on a predefined path by using fiducials for the detection of Right and Left turns on the path and White Strip for tracking the path. The HFMT technique is implemented and tested on an indoor mobile robot at our laboratory. Experimental results from robot navigating in real environments have confirmed that our approach is simple and robust and can be adopted in any hostile industrial environment where humans are unable to work.

  15. Automated Image Segmentation And Characterization Technique For Effective Isolation And Representation Of Human Face

    Directory of Open Access Journals (Sweden)

    Rajesh Reddy N

    2014-01-01

    Full Text Available In areas such as defense and forensics, it is necessary to identify the face of the criminals from the already available database. Automated face recognition system involves face isolation, feature extraction and classification technique. Challenges in face recognition system are isolating the face effectively as it may be affected by illumination, posture and variation in skin color. Hence it is necessary to develop an effective algorithm that isolates face from the image. In this paper, advanced face isolation technique and feature extraction technique has been proposed.

  16. Posterior Segment Intraocular Foreign Body: Extraction Surgical Techniques, Timing, and Indications for Vitrectomy

    Directory of Open Access Journals (Sweden)

    Dante A. Guevara-Villarreal

    2016-01-01

    Full Text Available Ocular penetrating injury with Intraocular Foreign Body (IOFB is a common form of ocular injury. Several techniques to remove IOFB have been reported by different authors. The aim of this publication is to review different timing and surgical techniques related to the extraction of IOFB. Material and Methods. A PubMed search on “Extraction of Intraocular Foreign Body,” “Timing for Surgery Intraocular Foreign Body,” and “Surgical Technique Intraocular Foreign Body” was made. Results. Potential advantages of immediate and delayed IOFB removal have been reported with different results. Several techniques to remove IOFB have been reported by different authors with good results. Conclusion. The most important factor at the time to perform IOFB extraction is the experience of the surgeon.

  17. Design and Development of Hybrid Multilevel Inverter employing Dual Reference Modulation Technique for Fuel Cell Applications

    Directory of Open Access Journals (Sweden)

    R. Seyezhai

    2011-10-01

    Full Text Available MultiLevel Inverter (MLI has been recognized as an attractive topology for high voltage DC-AC conversion. This paper focuses on a new dual reference modulation technique for a hybrid multilevel inverter employing Silicon carbide (SiC switches for fuel cell applications. The proposed modulation technique employs two reference waveforms and a single inverted sine wave as the carrier waveform. This technique is compared with the conventional dual carrier waveform in terms of output voltage spectral quality and switching losses. An experimental five-level hybrid inverter test rig has been built using SiC switches to implement the proposed algorithm. Gating signals are generated using PIC microcontroller. The performance of the inverter has been analyzed and compared with the result obtained from theory and simulation. Simulation study of Proportional Integral (PI controller for the inverter employing the proposed modulation strategy has been done in MATLAB/SIMULINK. Keywords: Multilevel inverter, SiC , dual reference modulation, switching losses, PI

  18. A hybrid segmentation approach for geographic atrophy in fundus auto-fluorescence images for diagnosis of age-related macular degeneration.

    Science.gov (United States)

    Lee, Noah; Laine, Andrew F; Smith, R Theodore

    2007-01-01

    Fundus auto-fluorescence (FAF) images with hypo-fluorescence indicate geographic atrophy (GA) of the retinal pigment epithelium (RPE) in age-related macular degeneration (AMD). Manual quantification of GA is time consuming and prone to inter- and intra-observer variability. Automatic quantification is important for determining disease progression and facilitating clinical diagnosis of AMD. In this paper we describe a hybrid segmentation method for GA quantification by identifying hypo-fluorescent GA regions from other interfering retinal vessel structures. First, we employ background illumination correction exploiting a non-linear adaptive smoothing operator. Then, we use the level set framework to perform segmentation of hypo-fluorescent areas. Finally, we present an energy function combining morphological scale-space analysis with a geometric model-based approach to perform segmentation refinement of false positive hypo- fluorescent areas due to interfering retinal structures. The clinically apparent areas of hypo-fluorescence were drawn by an expert grader and compared on a pixel by pixel basis to our segmentation results. The mean sensitivity and specificity of the ROC analysis were 0.89 and 0.98%.

  19. Hardwood species classification with DWT based hybrid texture feature extraction techniques

    Indian Academy of Sciences (India)

    Arvind R Yadav; R S Anand; M L Dewal; Sangeeta Gupta

    2015-12-01

    In this work, discrete wavelet transform (DWT) based hybrid texture feature extraction techniques have been used to categorize the microscopic images of hardwood species into 75 different classes. Initially, the DWT has been employed to decompose the image up to 7 levels using Daubechies (db3) wavelet as decomposition filter. Further, first-order statistics (FOS) and four variants of local binary pattern (LBP) descriptors are used to acquire distinct features of these images at various levels. The linear support vector machine (SVM), radial basis function (RBF) kernel SVM and random forest classifiers have been employed for classification. The classification accuracy obtained with state-of-the-art and DWT based hybrid texture features using various classifiers are compared. The DWT based FOS-uniform local binary pattern (DWTFOSLBPu2) texture features at the 4th level of image decomposition have produced best classification accuracy of 97.67 ± 0.79% and 98.40 ± 064% for grayscale and RGB images, respectively, using linear SVM classifier. Reduction in feature dataset by minimal redundancy maximal relevance (mRMR) feature selection method is achieved and the best classification accuracy of 99.00 ± 0.79% and 99.20 ± 0.42% have been obtained for DWT based FOS-LBP histogram Fourier features (DWTFOSLBP-HF) technique at the 5th and 6th levels of image decomposition for grayscale and RGB images, respectively, using linear SVM classifier. The DWTFOSLBP-HF features selected with mRMR method has also established superiority amongst the DWT based hybrid texture feature extraction techniques for randomly divided database into different proportions of training and test datasets.

  20. Establishment of a Multi-color Genomic in situ Hybridization Technique to Simultaneously Discriminate the Three Interspecific Hybrid Genomes in Gossypium

    Institute of Scientific and Technical Information of China (English)

    Bing Guan; Kai Wang; Bao-Liang Zhou; Wang-Zhen Guo; Tian-Zhen Zhang

    2008-01-01

    To identify alien chromosomes in recipient progenies and to analyze genome components in polyploidy, a genomic In situ hybridization (GISH) technique that is suitable for cotton was developed using increased stringency conditions. The increased stringency conditions were a combination of the four factors in the following optimized state: 100:1 ratio of blocking DNA to probe, 60% formamide wash solution, 43 =C temperature wash and a 13 min wash. Under these specific conditions using gDNA from Gossypium sturtianurn (C1C1) as a probe, strong hybridization signals were only observed on chromosomes from the C1 genome in somatic cells of the hybrid F1 (G. hirsutum×G. sturtianum) (AtDtC1). Therefore, GISH was able to discriminate parental chromosomes in the hybrid. Further, we developed a multi-color GISH to simultaneously discriminate the three genomes of the above hybrid. The results repeatedly displayed the three genomes, At, Dt, and C1, and each set of chromosomes with a unique color, making them easy to identify. The power of the multi-color GISH was proven by analysis of the hexaploid hybrid F1 (G. hirsutum × G. australe) (AtAtDtDtG2G2). We believe that the powerful multi-color GISH technique could be applied extensively to analyze the genome component in polyploidy and to identify alien chromosomes in the recipient progenies.

  1. Direct detection of expanded trinucleotide repeats using PCR and DNA hybridization techniques

    Energy Technology Data Exchange (ETDEWEB)

    Petronis, A.; Tatuch, Y.; Klempan, T.A.; Kennedy, J.L. [Hospital for Sick Children, Toronto (Canada)] [and others

    1996-02-16

    Recently, unstable trinucleotide repeats have been shown to be the etiologic factor in seven neuropsychiatric diseases, and they may play a similar role in other genetic disorders which exhibit genetic anticipation. We have tested one polymerase chain reaction (PCR)-based and two hybridization-based methods for direct detection of unstable DNA expansion in genomic DNA. This technique employs a single primer (asymmetric) PCR using total genomic DNA as a template to efficiently screen for the presence of large trinucleotide repeat expansions. High-stringency Southern blot hybridization with a PCR-generated trinucleotide repeat probe allowed detection of the DNA fragment containing the expansion. Analysis of myotonic dystrophy patients containing different degrees of (CTG){sub n} expansion demonstrated the identification of the site of trinucleotide instability in some affected individuals without any prior information regarding genetic map location. The same probe was used for fluorescent in situ hybridization and several regions of (CTG){sub n}/(CAG){sub n} repeats in the human genome were detected, including the myotonic dystrophy locus on chromosome 19q. Although limited at present to large trinucleotide repeat expansions, these strategies can be applied to directly clone genes involved in disorders caused by large expansions of unstable DNA. 33 refs., 4 figs.

  2. Biocompatibility improvement of titanium implants by coating with hybrid materials synthesized by sol-gel technique.

    Science.gov (United States)

    Catauro, M; Bollino, F; Papale, F

    2014-12-01

    Organic-inorganic hybrid materials based on zirconia and polyethylene glycol (PEG) have been synthesized via sol-gel method in the present study. Those materials, still in the sol phase, have been used to coat a titanium grade 4 (Ti-4) substrate to improve its biological properties. Dip-coating technique has been used to obtain thin films. PEG, a biocompatible polymer, used as the organic phase, has been incorporated with different percentages in an inorganic zirconium-based matrix. Those hybrids have been characterized by Fourier transform infrared spectroscopy (FTIR) to detect interactions between the two phases. The films have been examined using SEM to detect morphological changes with PEG percentages. The potential applications of the hybrid coatings in biomedical field have been evaluated by bioactivity and cytotoxicity tests. The coated titanium was immersed in simulated body fluid (SBF) for 21 days and the hydroxyapatite deposition on its surface was subsequently evaluated, as that feature can be used as an index of bone-bonding capability. SEM equipped with energy dispersive spectrometer (EDS) was used to examine hydroxyapatite formation. NIH 3T3 mouse embryonic fibroblast cells were seeded on specimens to evaluate cells-materials interactions and cell vitality was inspected using WST-8 Assay.

  3. Production of CaCO3/hyperbranched polyglycidol hybrid films using spray-coating technique.

    Science.gov (United States)

    Malinova, Kalina; Gunesch, Manfred; Montero Pancera, Sabrina; Wengeler, Robert; Rieger, Bernhard; Volkmer, Dirk

    2012-05-15

    Biomineralizing organisms employ macromolecules and cellular processing strategies in order to produce highly complex composite materials such as nacre. Bionic approaches translating this knowledge into viable technical production schemes for a large-scale production of biomimetic hybrid materials have met with limited success so far. Investigations presented here thus focus on the production of CaCO(3)/polymer hybrid coatings that can be applied to huge surface areas via reactive spray-coating. Technical requirements for simplicity and cost efficiency include a straightforward one-pot synthesis of low molecular weight hyperbranched polyglycidols (polyethers of 2,3-epoxy-1-propanol) as a simple mimic of biological macromolecules. Polymers functionalized with phosphate monoester, sulfate or carboxylate groups provide a means of controlling CaCO(3) particle density and morphology in the final coatings. We employ reactive spray-coating techniques to generate CaCO(3)/hybrid coatings among which vaterite composites can be prepared in the presence of sulfate-containing hyperbranched polyglycidol. These coatings show high stability and remained unchanged for periods longer than 9 months. By employing carboxylate-based hyperbranched polyglycidol, it is possible to deposit vaterite-calcite composites, whereas phosphate-ester-based hyperbranched polyglycidol leads to calcite composites. Nanoindentation was used to study mechanical properties, showing that coatings thus obtained are slightly harder than pure calcite. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Hybrid OPC modeling with SEM contour technique for 10nm node process

    Science.gov (United States)

    Hitomi, Keiichiro; Halle, Scott; Miller, Marshal; Graur, Ioana; Saulnier, Nicole; Dunn, Derren; Okai, Nobuhiro; Hotta, Shoji; Yamaguchi, Atsuko; Komuro, Hitoshi; Ishimoto, Toru; Koshihara, Shunsuke; Hojo, Yutaka

    2014-03-01

    Hybrid OPC modeling is investigated using both CDs from 1D and simple 2D structures and contours extracted from complex 2D structures, which are obtained by a Critical Dimension-Scanning Electron Microscope (CD-SEM). Recent studies have addressed some of key issues needed for the implementation of contour extraction, including an edge detection algorithm consistent with conventional CD measurements, contour averaging and contour alignment. Firstly, pattern contours obtained from CD-SEM images were used to complement traditional site driven CD metrology for the calibration of OPC models for both metal and contact layers of 10 nm-node logic device, developed in Albany Nano-Tech. The accuracy of hybrid OPC model was compared with that of conventional OPC model, which was created with only CD data. Accuracy of the model, defined as total error root-mean-square (RMS), was improved by 23% with the use of hybrid OPC modeling for contact layer and 18% for metal layer, respectively. Pattern specific benefit of hybrid modeling was also examined. Resist shrink correction was applied to contours extracted from CD-SEM images in order to improve accuracy of the contours, and shrink corrected contours were used for OPC modeling. The accuracy of OPC model with shrink correction was compared with that without shrink correction, and total error RMS was decreased by 0.2nm (12%) with shrink correction technique. Variation of model accuracy among 8 modeling runs with different model calibration patterns was reduced by applying shrink correction. The shrink correction of contours can improve accuracy and stability of OPC model.

  5. Strain analysis in CRT candidates using the novel segment length in cine (SLICE) post-processing technique on standard CMR cine images.

    Science.gov (United States)

    Zweerink, Alwin; Allaart, Cornelis P; Kuijer, Joost P A; Wu, LiNa; Beek, Aernout M; van de Ven, Peter M; Meine, Mathias; Croisille, Pierre; Clarysse, Patrick; van Rossum, Albert C; Nijveldt, Robin

    2017-06-27

    Although myocardial strain analysis is a potential tool to improve patient selection for cardiac resynchronization therapy (CRT), there is currently no validated clinical approach to derive segmental strains. We evaluated the novel segment length in cine (SLICE) technique to derive segmental strains from standard cardiovascular MR (CMR) cine images in CRT candidates. Twenty-seven patients with left bundle branch block underwent CMR examination including cine imaging and myocardial tagging (CMR-TAG). SLICE was performed by measuring segment length between anatomical landmarks throughout all phases on short-axis cines. This measure of frame-to-frame segment length change was compared to CMR-TAG circumferential strain measurements. Subsequently, conventional markers of CRT response were calculated. Segmental strains showed good to excellent agreement between SLICE and CMR-TAG (septum strain, intraclass correlation coefficient (ICC) 0.76; lateral wall strain, ICC 0.66). Conventional markers of CRT response also showed close agreement between both methods (ICC 0.61-0.78). Reproducibility of SLICE was excellent for intra-observer testing (all ICC ≥0.76) and good for interobserver testing (all ICC ≥0.61). The novel SLICE post-processing technique on standard CMR cine images offers both accurate and robust segmental strain measures compared to the 'gold standard' CMR-TAG technique, and has the advantage of being widely available. • Myocardial strain analysis could potentially improve patient selection for CRT. • Currently a well validated clinical approach to derive segmental strains is lacking. • The novel SLICE technique derives segmental strains from standard CMR cine images. • SLICE-derived strain markers of CRT response showed close agreement with CMR-TAG. • Future studies will focus on the prognostic value of SLICE in CRT candidates.

  6. Accuracy and reproducibility of a novel semi-automatic segmentation technique for MR volumetry of the pituitary gland

    Energy Technology Data Exchange (ETDEWEB)

    Renz, Diane M. [Charite University Medicine Berlin, Campus Virchow Clinic, Department of Radiology, Berlin (Germany); Hahn, Horst K.; Rexilius, Jan [Institute for Medical Image Computing, Fraunhofer MEVIS, Bremen (Germany); Schmidt, Peter [Friedrich-Schiller-University, Jena University Hospital, Institute of Diagnostic and Interventional Radiology, Department of Neuroradiology, Jena (Germany); Lentschig, Markus [MR- and PET/CT Centre Bremen, Bremen (Germany); Pfeil, Alexander [Friedrich-Schiller-University, Jena University Hospital, Department of Internal Medicine III, Jena (Germany); Sauner, Dieter [St. Georg Clinic Leipzig, Hospital Hubertusburg, Department of Radiology, Wermsdorf (Germany); Fitzek, Clemens [Asklepios Clinic Brandenburg, Department of Radiology and Neuroradiology, Brandenburg an der Havel (Germany); Mentzel, Hans-Joachim [Friedrich-Schiller-University, Jena University Hospital, Institute of Diagnostic and Interventional Radiology, Department of Pediatric Radiology, Jena (Germany); Kaiser, Werner A. [Friedrich-Schiller-University, Jena University Hospital, Institute of Diagnostic and Interventional Radiology, Jena (Germany); Reichenbach, Juergen R. [Friedrich-Schiller-University, Jena University Hospital, Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena (Germany); Boettcher, Joachim [SRH Clinic Gera, Institute of Diagnostic and Interventional Radiology, Gera (Germany)

    2011-04-15

    Although several reports about volumetric determination of the pituitary gland exist, volumetries have been solely performed by indirect measurements or manual tracing on the gland's boundaries. The purpose of this study was to evaluate the accuracy and reproducibility of a novel semi-automatic MR-based segmentation technique. In an initial technical investigation, T1-weighted 3D native magnetised prepared rapid gradient echo sequences (1.5 T) with 1 mm isotropic voxel size achieved high reliability and were utilised in different in vitro and in vivo studies. The computer-assisted segmentation technique was based on an interactive watershed transform after resampling and gradient computation. Volumetry was performed by three observers with different software and neuroradiologic experiences, evaluating phantoms of known volume (0.3, 0.9 and 1.62 ml) and healthy subjects (26 to 38 years; overall 135 volumetries). High accuracy of the volumetry was shown by phantom analysis; measurement errors were <4% with a mean error of 2.2%. In vitro, reproducibility was also promising with intra-observer variability of 0.7% for observer 1 and 0.3% for observers 2 and 3; mean inter-observer variability was in vitro 1.2%. In vivo, scan-rescan, intra-observer and inter-observer variability showed mean values of 3.2%, 1.8% and 3.3%, respectively. Unifactorial analysis of variance demonstrated no significant differences between pituitary volumes for various MR scans or software calculations in the healthy study groups (p > 0.05). The analysed semi-automatic MR volumetry of the pituitary gland is a valid, reliable and fast technique. Possible clinical applications are hyperplasia or atrophy of the gland in pathological circumstances either by a single assessment or by monitoring in follow-up studies. (orig.)

  7. SU-E-T-16: A Hybrid VMAT/IMRT Technique for the Treatment of Nasopharyngeal Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, N; Yang, R; Wang, J [Peking University Third Hospital, Beijing, Beijing (China)

    2014-06-01

    Purpose: To investigate a Hybrid VMAT/IMRT technique which combines volumetric modulated arc therapy (VMAT) and intensity modulated radiation therapy (IMRT) for nasopharyngeal carcinoma (NPC). Methods: 2 full arcs VMAT, 9-field IMRT and Hybrid VMAT/IMRT plans were created for 10 patients with NPC. The Hybrid VMAT/IMRT technique consisted of 1 full VMAT arc and 7 IMRT fields. The dose distribution of planning target volume (PTV) and organs at risk (OARs) for Hybrid VMAT/IMRT was compared with IMRT and VMAT. The monitor units (MUs) were also evaluated. Results: The Hybrid VMAT/IMRT technique significantly improved target dose homogeneity compared with IMRT and VMAT for PTV70 and PTV54. For PTV70 and PTV60, the Hybrid VMAT/IMRT technique significantly improved target dose conformity compared with IMRT (0.62 vs 0.47; p<0.05 and 0.64 vs 0.58; p<0.05, respectively) and VMAT (0.62 vs 0.43; p<0.05 and 0.64 vs 0.6; p<0.05, respectively). The near maximum dose (D2%) of temporomandibular joint (TMJ), temporal lobe and mandible for Hybrid plans were 5.5%, 7.9% and 5.2% lower than IMRT plans (p<0.05). The mean dose of TMJ, temporal lobe, mandible and unspecified tissue for Hybrid plans were 12.8%, 11.4%, 4.2% and 4.1% lower than IMRT plans (p<0.05). The mean dose of right parotid, mandible and unspecified tissue for Hybrid plans were 3.3%, 2.4% and 3.1% lower than VMAT plans (p<0.05). The mean MUs needed for IMRT, VMAT and Hybrid plans were 2256, 507 and 1394, respectively. Conclusion: Hybrid VMAT/IMRT technique significantly improved the target dose homogeneity and conformity compared with IMRT and VMAT and reduced the dose of OARs and unspecified tissue compared with IMRT with fewer MUs. Compared with VMAT, Hybrid VMAT/IMRT technique can better protect parotid gland, mandible and unspecified tissue. Ruijie Yang was funded by the grant project: National Natural Science Foundation of China (No. 81071237). Other authors have no competing interest for this work.

  8. Apical transportation of manual NiTi instruments and a hybrid technique in severely curved simulated canals

    OpenAIRE

    Aurenaila Nascimento Gonçalves; Matheus Franco da Frota; Emilio Carlos Sponchiado Júnior; Fredson Marcio Acris de Carvalho; Lucas da Fonseca Roberti Garcia; André Augusto Franco Marques

    2015-01-01

    Aim: To evaluate the apical transportation induced by two instrumentation techniques in severely curved simulated canals. Materials and Methods: Forty simulated canals were divided into two groups (n = 20), according to the following instrumentation techniques: ProTaper Universal Manual System and a hybrid technique. The simulated canals in the ProTaper group were prepared following the technique recommended by the manufacturer: SX files in the cervical third of the root canal and S1, S2,...

  9. Enhancement in Seismic Imaging using Diffraction Studies and Hybrid Traveltime Technique for PSDM

    Science.gov (United States)

    Bashir, Y.; Ghosh, D. P.; Moussavi Alashloo, S. Y.; Sum, C. W.

    2016-07-01

    The accurate migration of seismic data is conditional on the parameters which are nominated. The effective velocity used in residual processing for migration is small compared to the original migration velocity. Considering traveltime computation is a significant part of seismic imaging algorithms. Conventional implementation of Kirchhoff migration is essential for precomputing a traveltime table from the categories involving traditional ray-tracing methods and finite difference eikonal solvers. In this paper, we examine the accuracy using, the eikonal solver and paraxial ray tracing traveltime computation in pre-stack Kirchhoff depth migration. This hybrid traveltime technique can be applied to a variety of problems related to faults, fractures, and complex region. To evaluate the relevance of this identical traveltime technique, we applied on a Marmousi data set.

  10. REVIEW OF HEART DISEASE PREDICTION SYSTEM USING DATA MINING AND HYBRID INTELLIGENT TECHNIQUES

    Directory of Open Access Journals (Sweden)

    R. Chitra

    2013-07-01

    Full Text Available The Healthcare industry generally clinical diagnosis is done mostly by doctor’s expertise and experience. Computer Aided Decision Support System plays a major role in medical field. With the growing research on heart disease predicting system, it has become important to categories the research outcomes and provides readers with an overview of the existing heart disease prediction techniques in each category. Neural Networks are one of many data mining analytical tools that can be utilized to make predictions for medical data. From the study it is observed that Hybrid Intelligent Algorithm improves the accuracy of the heart disease prediction system. The commonly used techniques for Heart Disease Prediction and their complexities are summarized in this paper.

  11. Local tetrahedron modeling of microelectronics using the finite-volume hybrid-grid technique

    Energy Technology Data Exchange (ETDEWEB)

    Riley, D.J.; Turner, C.D.

    1995-12-01

    The finite-volume hybrid-grid (FVHG) technique uses both structured and unstructured grid regions in obtaining a solution to the time-domain Maxwell`s equations. The method is based on explicit time differencing and utilizes rectilinear finite-difference time-domain (FDTD) and nonorthogonal finite-volume time-domain (FVTD). The technique directly couples structured FDTD grids with unstructured FVTD grids without the need for spatial interpolation across grid interfaces. In this paper, the FVHG method is applied to simple planar microelectronic devices. Local tetrahedron grids are used to model portions of the device under study, with the remainder of the problem space being modeled with cubical hexahedral cells. The accuracy of propagating microstrip-guided waves from a low-density hexahedron region through a high-density tetrahedron grid is investigated.

  12. Enhancement of Twins Fetal ECG Signal Extraction Based on Hybrid Blind Extraction Techniques

    Directory of Open Access Journals (Sweden)

    Ahmed Kareem Abdullah

    2017-07-01

    Full Text Available ECG machines are noninvasive system used to measure the heartbeat signal. It’s very important to monitor the fetus ECG signals during pregnancy to check the heat activity and to detect any problem early before born, therefore the monitoring of ECG signals have clinical significance and importance. For multi-fetal pregnancy case the classical filtering algorithms are not sufficient to separate the ECG signals between mother and fetal. In this paper the mixture consists of mixing from three ECG signals, the first signal is the mother ECG (M-ECG signal, second signal the Fetal-1 ECG (F1-ECG, and third signal is the Fetal-2 ECG (F2-ECG, these signals are extracted based on modified blind source extraction (BSE techniques. The proposed work based on hybridization between two BSE techniques to ensure that the extracted signals separated well. The results demonstrate that the proposed work very efficiently to extract the useful ECG signals

  13. Estimation of radon concentrations in coal mines using a hybrid technique calibration curve.

    Science.gov (United States)

    Jamil, K; Ali, S

    2001-01-01

    The results of epidemiological studies in various countries show that radon and its progeny cause carcinogenic effects on mine workers. Therefore, it becomes of paramount importance to monitor radon concentrations and consequently determine the radon dose rates in coal mines for the protection of coal miners. A new calibration curve was obtained for radon concentration estimation using hybrid techniques. A calibration curve was generated using 226Ra activity concentration measured by a HPGe detector-based gamma-ray spectrometer versus alpha-track-density rate due to radon and its progeny on CR-39 track detector. Using the slope of the experimentally determined curve in the units of Becqueral per kilogram (Bq kg-1) per unit alpha-track-density per hour (cm-2 h-1), radon concentrations (Bq m-3) were estimated using coal samples from various coal mines in two provinces of Pakistan, Punjab and Balochistan. Consequently, radon dose rates were computed in the simulated environment of the coal mines. Results of these computations may be considered with a caveat that the method developed in this paper provides only a screening method to indicate the radon dose in coal mines. It has been shown that the actual measurements of radon concentrations in the coal mines are in agreement with the estimated radon concentrations using the hybrid-technique calibration curve.

  14. Hybrid Model Testing Technique for Deep-Sea Platforms Based on Equivalent Water Depth Truncation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper, an inner turret moored FPSO which works in the water of 320 m depth, is selected to study the so-called "passively-truncated + numerical-simulation" type of hybrid model testing technique while the truncated water depth is 160 m and the model scale λ=80. During the investigation, the optimization design of the equivalent-depth truncated system is performed by using the similarity of the static characteristics between the truncated system and the full depth one as the objective function. According to the truncated system, the corresponding physical test model is made. By adopting the coupling time domain simulation method, the truncated system model test is numerically reconstructed to carefully verify the computer simulation software and to adjust the corresponding hydrodynamic parameters. Based on the above work, the numerical extrapolation to the full depth system is performed by using the verified computer software and the adjusted hydrodynamic parameters. The full depth system model test is then performed in the basin and the results are compared with those from the numerical extrapolation. At last, the implementation procedure and the key technique of the hybrid model testing of the deep-sea platforms are summarized and printed. Through the above investigations, some beneficial conclusions are presented.

  15. Novel Hybrid Scheduling Technique for Sensor Nodes with Mixed Criticality Tasks

    Directory of Open Access Journals (Sweden)

    Mihai-Victor Micea

    2017-06-01

    Full Text Available Sensor networks become increasingly a key technology for complex control applications. Their potential use in safety- and time-critical domains has raised the need for task scheduling mechanisms specially adapted to sensor node specific requirements, often materialized in predictable jitter-less execution of tasks characterized by different criticality levels. This paper offers an efficient scheduling solution, named Hybrid Hard Real-Time Scheduling (H2RTS, which combines a static, clock driven method with a dynamic, event driven scheduling technique, in order to provide high execution predictability, while keeping a high node Central Processing Unit (CPU utilization factor. From the detailed, integrated schedulability analysis of the H2RTS, a set of sufficiency tests are introduced and demonstrated based on the processor demand and linear upper bound metrics. The performance and correct behavior of the proposed hybrid scheduling technique have been extensively evaluated and validated both on a simulator and on a sensor mote equipped with ARM7 microcontroller.

  16. Skill Assessment of An Hybrid Technique To Estimate Quantitative Precipitation Forecast For Galicia (nw Spain)

    Science.gov (United States)

    Lage, A.; Taboada, J. J.

    Precipitation is the most obvious of the weather elements in its effects on normal life. Numerical weather prediction (NWP) is generally used to produce quantitative precip- itation forecast (QPF) beyond the 1-3 h time frame. These models often fail to predict small-scale variations of rain because of spin-up problems and their coarse spatial and temporal resolution (Antolik, 2000). Moreover, there are some uncertainties about the behaviour of the NWP models in extreme situations (de Bruijn and Brandsma, 2000). Hybrid techniques, combining the benefits of NWP and statistical approaches in a flexible way, are very useful to achieve a good QPF. In this work, a new technique of QPF for Galicia (NW of Spain) is presented. This region has a percentage of rainy days per year greater than 50% with quantities that may cause floods, with human and economical damages. The technique is composed of a NWP model (ARPS) and a statistical downscaling process based on an automated classification scheme of at- mospheric circulation patterns for the Iberian Peninsula (J. Ribalaygua and R. Boren, 1995). Results show that QPF for Galicia is improved using this hybrid technique. [1] Antolik, M.S. 2000 "An Overview of the National Weather Service's centralized statistical quantitative precipitation forecasts". Journal of Hydrology, 239, pp:306- 337. [2] de Bruijn, E.I.F and T. Brandsma "Rainfall prediction for a flooding event in Ireland caused by the remnants of Hurricane Charley". Journal of Hydrology, 239, pp:148-161. [3] Ribalaygua, J. and Boren R. "Clasificación de patrones espaciales de precipitación diaria sobre la España Peninsular". Informes N 3 y 4 del Servicio de Análisis e Investigación del Clima. Instituto Nacional de Meteorología. Madrid. 53 pp.

  17. Fast hybrid CPU- and GPU-based CT reconstruction algorithm using air skipping technique.

    Science.gov (United States)

    Lee, Byeonghun; Lee, Ho; Shin, Yeong Gil

    2010-01-01

    This paper presents a fast hybrid CPU- and GPU-based CT reconstruction algorithm to reduce the amount of back-projection operation using air skipping involving polygon clipping. The algorithm easily and rapidly selects air areas that have significantly higher contrast in each projection image by applying K-means clustering method on CPU, and then generates boundary tables for verifying valid region using segmented air areas. Based on these boundary tables of each projection image, clipped polygon that indicates active region when back-projection operation is performed on GPU is determined on each volume slice. This polygon clipping process makes it possible to use smaller number of voxels to be back-projected, which leads to a faster GPU-based reconstruction method. This approach has been applied to a clinical data set and Shepp-Logan phantom data sets having various ratio of air region for quantitative and qualitative comparison and analysis of our and conventional GPU-based reconstruction methods. The algorithm has been proved to reduce computational time to half without losing any diagnostic information, compared to conventional GPU-based approaches.

  18. A hybrid MAS/MoM technique for 2D impedance scatterers illuminated by closely positioned sources

    DEFF Research Database (Denmark)

    Larsen, Niels Vesterdal; Breinbjerg, Olav

    2005-01-01

    A hybrid technique for 2D scattering problems with impedance structures and closely positioned illuminating sources is presented. This technique combines the method of auxiliary sources (MAS) with a localized method of moments (MoM) region near the source. Significant improvements over standard MAS...

  19. Fingerprint Segmentation

    OpenAIRE

    Jomaa, Diala

    2009-01-01

    In this thesis, a new algorithm has been proposed to segment the foreground of the fingerprint from the image under consideration. The algorithm uses three features, mean, variance and coherence. Based on these features, a rule system is built to help the algorithm to efficiently segment the image. In addition, the proposed algorithm combine split and merge with modified Otsu. Both enhancements techniques such as Gaussian filter and histogram equalization are applied to enhance and improve th...

  20. Posterior lumbar dynamic stabilization instead of arthrodesis for symptomatic adjacent-segment degenerative stenosis: description of a novel technique.

    Science.gov (United States)

    Mashaly, Hazem; Paschel, Erin E; Khattar, Nicolas K; Goldschmidt, Ezequiel; Gerszten, Peter C

    2016-01-01

    OBJECTIVE The development of symptomatic adjacent-segment disease (ASD) is a well-recognized consequence of lumbar fusion surgery. Extension of a fusion to a diseased segment may only lead to subsequent adjacent-segment degeneration. The authors report the use of a novel technique that uses dynamic stabilization instead of arthrodesis for the surgical treatment of symptomatic ASD following a prior lumbar instrumented fusion. METHODS A cohort of 28 consecutive patients was evaluated who developed symptomatic stenosis immediately adjacent to a previous lumbar instrumented fusion. All patients had symptoms of neurogenic claudication refractory to nonsurgical treatment and were surgically treated with decompression and dynamic stabilization instead of extending the fusion construct using a posterior lumbar dynamic stabilization system. Preoperative symptoms, visual analog scale (VAS) pain scores, and perioperative complications were recorded. Clinical outcome was gauged by comparing VAS scores prior to surgery and at the time of last follow-up. RESULTS The mean follow-up duration was 52 months (range 17-94 months). The mean interval from the time of primary fusion surgery to the dynamic stabilization surgery was 40 months (range 10-96 months). The mean patient age was 51 years (range 29-76 years). There were 19 (68%) men and 9 (32%) women. Twenty-three patients (82%) presented with low-back pain at time of surgery, whereas 24 patients (86%) presented with lower-extremity symptoms only. Twenty-four patients (86%) underwent operations that were performed using single-level dynamic stabilization, 3 patients (11%) were treated at 2 levels, and 1 patient underwent 3-level decompression and dynamic stabilization. The most commonly affected and treated level (46%) was L3-4. The mean preoperative VAS pain score was 8, whereas the mean postoperative score was 3. No patient required surgery for symptomatic degeneration rostral to the level of dynamic stabilization during the

  1. WRHT: A Hybrid Technique for Detection of Wormhole Attack in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Rupinder Singh

    2016-01-01

    Full Text Available Wormhole attack is a challenging security threat to wireless sensor networks which results in disrupting most of the routing protocols as this attack can be triggered in different modes. In this paper, WRHT, a wormhole resistant hybrid technique, is proposed, which can detect the presence of wormhole attack in a more optimistic manner than earlier techniques. WRHT is based on the concept of watchdog and Delphi schemes and ensures that the wormhole will not be left untreated in the sensor network. WRHT makes use of the dual wormhole detection mechanism of calculating probability factor time delay probability and packet loss probability of the established path in order to find the value of wormhole presence probability. The nodes in the path are given different ranking and subsequently colors according to their behavior. The most striking feature of WRHT consists of its capacity to defend against almost all categories of wormhole attacks without depending on any required additional hardware such as global positioning system, timing information or synchronized clocks, and traditional cryptographic schemes demanding high computational needs. The experimental results clearly indicate that the proposed technique has significant improvement over the existing wormhole attack detection techniques.

  2. Hybrid Clustering-GWO-NARX neural network technique in predicting stock price

    Science.gov (United States)

    Das, Debashish; Safa Sadiq, Ali; Mirjalili, Seyedali; Noraziah, A.

    2017-09-01

    Prediction of stock price is one of the most challenging tasks due to nonlinear nature of the stock data. Though numerous attempts have been made to predict the stock price by applying various techniques, yet the predicted price is not always accurate and even the error rate is high to some extent. Consequently, this paper endeavours to determine an efficient stock prediction strategy by implementing a combinatorial method of Grey Wolf Optimizer (GWO), Clustering and Non Linear Autoregressive Exogenous (NARX) Technique. The study uses stock data from prominent stock market i.e. New York Stock Exchange (NYSE), NASDAQ and emerging stock market i.e. Malaysian Stock Market (Bursa Malaysia), Dhaka Stock Exchange (DSE). It applies K-means clustering algorithm to determine the most promising cluster, then MGWO is used to determine the classification rate and finally the stock price is predicted by applying NARX neural network algorithm. The prediction performance gained through experimentation is compared and assessed to guide the investors in making investment decision. The result through this technique is indeed promising as it has shown almost precise prediction and improved error rate. We have applied the hybrid Clustering-GWO-NARX neural network technique in predicting stock price. We intend to work with the effect of various factors in stock price movement and selection of parameters. We will further investigate the influence of company news either positive or negative in stock price movement. We would be also interested to predict the Stock indices.

  3. A genome-wide survey of hybrid incompatibility factors by the introgression of marked segments of Drosophila mauritiana chromosomes into Drosophila simulans

    Energy Technology Data Exchange (ETDEWEB)

    True, J.R.; Laurie, C.C. [Duke Univ., Durham, NC (United States); Weir, B.S. [North Carolina State Univ., Raleigh, NC (United States)

    1996-03-01

    In hybrids between Drosophila simulans and D. mauritiana, males are sterile and females are fertile, in compliance with HALDANE`s rule. The genetic basis of this phenomenon was investigated by introgression of segments of the mauritiana genome into a simulans background. A total of 87 positions throughout the mauritiana genome were marked with P-element insertions and replicate introgressions were made by repeated backcrossing to simulans for 15 generations. The fraction of hemizygous X chromosomal introgressions that are male sterile is {approximately}50% greater than the fraction of homozygous autosomal segments. This result suggests that male sterility factors have evolved at a higher rate on the X, but chromosomal differences in segment length cannot be ruled out. The fraction of homozygous autosomal introgressions that are male sterile is several times greater than the fraction that are either female sterile or inviable. This observation strongly indicates that male sterility factors have evolved more rapidly than either female sterility or inviability factors. These results, combined with previous work on these and other species, suggest that HALDANE`s rule has at least two causes: recessivity of incompatibility factors and differential accumulation of sterility factors affecting males and females. 50 refs., 4 figs., 3 tabs.

  4. Potentials of Optical Damage Assessment Techniques in Automotive Crash-Concepts composed of FRP-Steel Hybrid Material Systems

    Science.gov (United States)

    Dlugosch, M.; Spiegelhalter, B.; Soot, T.; Lukaszewicz, D.; Fritsch, J.; Hiermaier, S.

    2017-05-01

    With car manufacturers simultaneously facing increasing passive safety and efficiency requirements, FRP-metal hybrid material systems are one way to design lightweight and crashworthy vehicle structures. Generic automotive hybrid structural concepts have been tested under crash loading conditions. In order to assess the state of overall damage and structural integrity, and primarily to validate simulation data, several NDT techniques have been assessed regarding their potential to detect common damage mechanisms in such hybrid systems. Significant potentials were found particularly in combining 3D-topography laser scanning and X-Ray imaging results. Ultrasonic testing proved to be limited by the signal coupling quality on damaged or curved surfaces.

  5. Segmenting multiple overlapping objects via a hybrid active contour model incorporating shape priors: applications to digital pathology

    Science.gov (United States)

    Ali, Sahirzeeshan; Madabhushi, Anant

    2011-03-01

    Active contours and active shape models (ASM) have been widely employed in image segmentation. A major limitation of active contours, however, is in their (a) inability to resolve boundaries of intersecting objects and to (b) handle occlusion. Multiple overlapping objects are typically segmented out as a single object. On the other hand, ASMs are limited by point correspondence issues since object landmarks need to be identified across multiple objects for initial object alignment. ASMs are also are constrained in that they can usually only segment a single object in an image. In this paper, we present a novel synergistic boundary and region-based active contour model that incorporates shape priors in a level set formulation. We demonstrate an application of these synergistic active contour models using multiple level sets to segment nuclear and glandular structures on digitized histopathology images of breast and prostate biopsy specimens. Unlike previous related approaches, our model is able to resolve object overlap and separate occluded boundaries of multiple objects simultaneously. The energy functional of the active contour is comprised of three terms. The first term comprises the prior shape term, modeled on the object of interest, thereby constraining the deformation achievable by the active contour. The second term, a boundary based term detects object boundaries from image gradients. The third term drives the shape prior and the contour towards the object boundary based on region statistics. The results of qualitative and quantitative evaluation on 100 prostate and 14 breast cancer histology images for the task of detecting and segmenting nuclei, lymphocytes, and glands reveals that the model easily outperforms two state of the art segmentation schemes (Geodesic Active Contour (GAC) and Roussons shape based model) and resolves up to 92% of overlapping/occluded lymphocytes and nuclei on prostate and breast cancer histology images.

  6. Recent advances in knowledge-based paradigms and applications enhanced applications using hybrid artificial intelligence techniques

    CERN Document Server

    Jain, Lakhmi

    2014-01-01

    This book presents carefully selected contributions devoted to the modern perspective of AI research and innovation. This collection covers several areas of applications and motivates new research directions. The theme across all chapters combines several domains of AI research , Computational Intelligence and Machine Intelligence including an introduction to  the recent research and models. Each of the subsequent chapters reveals leading edge research and innovative solution that employ AI techniques with an applied perspective. The problems include classification of spatial images, early smoke detection in outdoor space from video images, emergent segmentation from image analysis, intensity modification in images, multi-agent modeling and analysis of stress. They all are novel pieces of work and demonstrate how AI research contributes to solutions for difficult real world problems that benefit the research community, industry and society.

  7. Hydrophobicity control by a supercritical drying technique in a sol–gel process with hybrid materials

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Hongbo; Qiao, Zemin; Liu, Xiao; Cui, Xudong, E-mail: xudcui@gmail.com

    2015-10-15

    Highlights: • Sol–gel route is combined with polymerization without using modifier. • Supercritical drying control is the key to obtain super-hydrophobic surfaces. • The whole fabrication is technologically controllable and with low costs. • The production rate is higher than 90%. • The method provides a cost-effective way for industry applications. - Abstract: We successfully synthesized one type of cheap super-hydrophobic hybrid porous materials in a sol–gel process. In this route, hydrophilic polymers and TEOS-base sol are used as precursors, the ultraviolet ray-initiated polymerization and supercritical fluid drying techniques are combined together to fulfill this task. All fabricated samples exhibit lotus-leaf-like surface structures with super-hydrophobicity. The underlying mechanisms are carefully investigated using a field-emission scanning electron microscopy (FESEM) and an X-ray photoelectron spectroscopy (XPS). We found that a well-controlled drying process is crucial to the formation of such super-hydrophobic surfaces. As high as 90% production rate is obtained in our route and thus, it might provide a cost-effective way to produce super-hydrophobic hybrid materials for industry applications.

  8. Adaptation of Hybrid FSO/RF Communication System Using Puncturing Technique

    Directory of Open Access Journals (Sweden)

    M. N. Khan

    2016-12-01

    Full Text Available Spectrum of radio frequency (RF communications is limited and expensive to install new applications. Free space optical (FSO communication is a viable technology which offers enormous bandwidth, license free installation, inexpensive deployment and error prone links. The FSO links degrade significantly due to the varying atmospheric and weather conditions (fog, cloud, snow, haze and combination of these. We propose a hybrid FSO/RF communication system which adapts the varying nature of atmosphere and weather. For the adaption of varying atmosphere and weather scenarios, we develop a novel optimization algorithm. The proposed algorithm is based on the well-known puncturing technique. We provide an extrinsic information transfer (EXIT chart for the binary and quaternary mapping scheme for the proposed communication system. We simulate the proposed algorithm for the hybrid communication system and analyze the system performance. The proposed algorithm is computationally less expensive and provide better performance gains over varying atmosphere and weather conditions. The algorithm is suitable for fast speed applications.

  9. A millisecond micro-RNA separation technique by a hybrid structure of nanopillars and nanoslits.

    Science.gov (United States)

    Wu, Qiong; Kaji, Noritada; Yasui, Takao; Rahong, Sakon; Yanagida, Takeshi; Kanai, Masaki; Nagashima, Kazuki; Tokeshi, Manabu; Kawai, Tomoji; Baba, Yoshinobu

    2017-03-08

    A millisecond micro-RNA separation of a mixture of total RNA and genomic DNA, extracted from cultured HeLa cells, was successfully achieved using a hybrid structure of nanopillars and nanoslits contained inside a microchannel. The nanopillars, 250-nm in diameter and 100-nm in height, were fabricated with a 750-nm space inside the nanoslits, which were 100-nm in height and 25-μm in width; the nanopillars were then applied as a new sieve matrix. This ultra-fast technique for the separation of miRNA can be an effective pretreatment for semiconductor nanopore DNA sequencing, which has an optimum reading speed of 1 base/ms to obtain effective signal-to-noise ratio and discriminate each base by ion or tunneling current during the passage of nucleic acids.

  10. Modified Genetic Algorithm for DNA Sequence Assembly by Shotgun and Hybridization Sequencing Techniques

    Directory of Open Access Journals (Sweden)

    Prof.Narayan Kumar Sahu

    2012-09-01

    Full Text Available Since the advent of rapid DNA sequencing methods in 1976, scientists have had the problem of inferring DNA sequences from sequenced fragments. Shotgun sequencing is a well-established biological and computational method used in practice. Many conventional algorithms for shotgun sequencing are based on the notion of pair wise fragment overlap. While shotgun sequencing infers a DNA sequence given the sequences of overlapping fragments, a recent and complementary method, called sequencing by hybridization (SBH, infers a DNA sequence given the set of oligomers that represents all sub words of some fixed length, k. In this paper, we propose a new computer algorithm for DNA sequence assembly that combines in a novel way the techniques of both shotgun and SBH methods. Based on our preliminary investigations, the algorithm promises- to be very fast and practical for DNA sequence assembly [1].

  11. Dual Fixation of Calcaneal Tuberosity Avulsion with Concomitant Achilles Tendon Rupture: A Novel Hybrid Technique

    Directory of Open Access Journals (Sweden)

    Gautham Prabhakar

    2017-01-01

    Full Text Available Fracture of the calcaneal tuberosity with a concomitant Achilles tendon rupture presents a difficult challenge for the treating surgeon. The ultimate goal of treatment is to restore function of both the gastrocnemius-soleus complex and the Achilles tendon. This particular subset of fractures occurs often in diabetics and elderly patients with osteoporosis making fixation of the displaced fragment rather complex. If the Achilles tendon disruption is only discovered later once the fracture is healed, subsequent management is difficult with surgical treatment being more morbid. While this is a rare injury, the consequences of a missed chronic Achilles tendon disruption are severe with significant dysfunction. It is therefore important to have a high index of suspicion for concomitant injury and to be prepared for dual fixation. We present a novel hybrid surgical fixation technique, which may be used in this instance.

  12. Estimation of radon concentrations in coal mines using a hybrid technique calibration curve

    Energy Technology Data Exchange (ETDEWEB)

    Jamil, K.; Ali, S. [PINSTECH, Islamabad (Pakistan). Radiation Physics Division, Environmental Radiation Group

    2001-07-01

    A calibration curve was generated using Ra-226 activity concentration measured by a HPGe detector-based gamma-ray spectrometer versus alpha-track-density rate due to radon and its progeny on CR-39 track detector. Using the slops of the experimentally determined curve in the units of Becquerel per kilogram (Bq kg{sup -1}) per unit alpha -track-density per hour (cm{sup -2}h{sup -1}), radon concentrations (Bq m{sup -3}) were estimated using coal samples from various coal mines in two provinces of Pakistan, Punjab and Balochistan. Consequently, radon dose rates were computed in the simulated environment of the coal mines. These results provide only a screening method to indicate the radon dose in coal mines, It was shown that the actual measurements of radon concentrations in the coal mines are in agreement with the estimated radon concentrations using the hybrid-technique calibration curve.

  13. A millisecond micro-RNA separation technique by a hybrid structure of nanopillars and nanoslits

    Science.gov (United States)

    Wu, Qiong; Kaji, Noritada; Yasui, Takao; Rahong, Sakon; Yanagida, Takeshi; Kanai, Masaki; Nagashima, Kazuki; Tokeshi, Manabu; Kawai, Tomoji; Baba, Yoshinobu

    2017-01-01

    A millisecond micro-RNA separation of a mixture of total RNA and genomic DNA, extracted from cultured HeLa cells, was successfully achieved using a hybrid structure of nanopillars and nanoslits contained inside a microchannel. The nanopillars, 250-nm in diameter and 100-nm in height, were fabricated with a 750-nm space inside the nanoslits, which were 100-nm in height and 25-μm in width; the nanopillars were then applied as a new sieve matrix. This ultra-fast technique for the separation of miRNA can be an effective pretreatment for semiconductor nanopore DNA sequencing, which has an optimum reading speed of 1 base/ms to obtain effective signal-to-noise ratio and discriminate each base by ion or tunneling current during the passage of nucleic acids. PMID:28272420

  14. Development of a fluorescent in situ hybridization (FISH) technique for visualizing CGMMV in plant tissues.

    Science.gov (United States)

    Shargil, D; Zemach, H; Belausov, E; Lachman, O; Kamenetsky, R; Dombrovsky, A

    2015-10-01

    Cucumber green mottle mosaic virus (CGMMV), which belongs to the genus Tobamovirus, is a major pathogen of cucurbit crops grown indoors and in open fields. Currently, immunology (e.g., ELISA) and molecular amplification techniques (e.g., RT-PCR) are employed extensively for virus detection in plant tissues and commercial seed lots diagnostics. In this study, a fluorescent in situ hybridization (FISH) technique, using oligonucleotides whose 5'-terminals were labeled with red cyanine 3 (Cy3) or green fluorescein isothiocyanate (FITC), was developed for the visualization of the pathogen in situ. This simple and reliable method allows detection and localization of CGMMV in the vegetative and reproductive tissues of cucumber and melon. When this technique was applied in male flowers, anther tissues were found to be infected; whereas the pollen grains were found to be virus-free. These results have meaningful epidemiological implications for the management of CGMMV, particularly with regard to virus transfer via seed and the role of insects as CGMMV vectors.

  15. A hybrid technique for private location-based queries with database protection

    KAUST Repository

    Ghinita, Gabriel

    2009-01-01

    Mobile devices with global positioning capabilities allow users to retrieve points of interest (POI) in their proximity. To protect user privacy, it is important not to disclose exact user coordinates to un-trusted entities that provide location-based services. Currently, there are two main approaches to protect the location privacy of users: (i) hiding locations inside cloaking regions (CRs) and (ii) encrypting location data using private information retrieval (PIR) protocols. Previous work focused on finding good trade-offs between privacy and performance of user protection techniques, but disregarded the important issue of protecting the POI dataset D. For instance, location cloaking requires large-sized CRs, leading to excessive disclosure of POIs (O(|D|) in the worst case). PIR, on the other hand, reduces this bound to , but at the expense of high processing and communication overhead. We propose a hybrid, two-step approach to private location-based queries, which provides protection for both the users and the database. In the first step, user locations are generalized to coarse-grained CRs which provide strong privacy. Next, a PIR protocol is applied with respect to the obtained query CR. To protect excessive disclosure of POI locations, we devise a cryptographic protocol that privately evaluates whether a point is enclosed inside a rectangular region. We also introduce an algorithm to efficiently support PIR on dynamic POI sub-sets. Our method discloses O(1) POI, orders of magnitude fewer than CR- or PIR-based techniques. Experimental results show that the hybrid approach is scalable in practice, and clearly outperforms the pure-PIR approach in terms of computational and communication overhead. © 2009 Springer Berlin Heidelberg.

  16. An Alternate Vista in Rehabilitation of Cranial Defects: Combining Digital and Manual Techniques to Fabricate a Hybrid Cranioplast.

    Science.gov (United States)

    Kaur, Harsimran; Nanda, Aditi; Koli, Dheeraj; Verma, Mahesh; Singh, Hukum; Bishnoi, Ishu; Pathak, Pooja; Gupta, Ankur

    2015-06-01

    The desired features of a cranioplast include providing an acceptable contour, continuity with the remaining skull (marginal adaptation), improvising the aesthetic outcome, providing a strengthened prosthesis to avoid fracture in case of repeat trauma, and protecting the remaining neurological structures. Combining digital and manual techniques to fabricate a hybrid polymethylmethacrylate cranioplast during the rehabilitation of a pediatric patient with cranial defect has been described. Utilization of digital techniques (rapid prototyping to obtain skull analog) and manual (hand) sculpting of the prosthesis strengthened with glass fiber enabled the authors to fabricate a hybrid cranioplast. Satisfactory outcome was achieved.

  17. A novel fluorescent in situ hybridization technique for detection of Rickettsia spp. in archival samples

    DEFF Research Database (Denmark)

    Svendsen, Claus Bo; Boye, Mette; Struve, Carsten

    2009-01-01

    A novel, sensitive and specific method for detecting Rickettsia spp. in archival samples is described. The method involves the use of fluorescently marked oligonucleotide probes for in situ hybridization. Specific hybridization of Ricekttsia was found without problems of cross-reactions with bact......A novel, sensitive and specific method for detecting Rickettsia spp. in archival samples is described. The method involves the use of fluorescently marked oligonucleotide probes for in situ hybridization. Specific hybridization of Ricekttsia was found without problems of cross...

  18. Evaluation of intrastromal corneal ring segments for treatment of post-LASIK ectasia patients with a mechanical implantation technique

    Directory of Open Access Journals (Sweden)

    Zeki Tunc

    2011-01-01

    Full Text Available Aim: To evaluate the clinical outcomes of Keraring segment implantation in patients with post- laser-assisted in situ keratomileusis (LASIK ectasia, using a mechanical implantation technique. Materials and Methods: Twelve eyes of 10 patients with post-LASIK ectasia were enrolled. Intracorneal ring segments (ICRS were implanted after dissection of the tunnel using Tunc′s specially designed dissector under suction. A complete ophthalmic examination was performed, including uncorrected distance visual acuity (UDVA, corrected distance visual acuity (CDVA, spherical equivalent, keratometric (K readings, inferosuperior asymmetry index (ISAI, and ultrasound pachymetry. All 3, 6, and 12-month follow-ups were completed, and statistical analysis was performed. Results: The mean preoperative UDVA for all eyes was 1.28 ± 0.59 logMAR. At 12 months, the mean UDVA was 0.36 ± 0.19 logarithm of the Minimum Angle of Resolution (logMAR (P=0.002, and the mean preoperative CDVA was 0.58 ± 0.3 logMAR, which improved to 0.15 ± 0.12 (P=0.002 at 1 year. There was a significant reduction in cylindrical refractive and spherical equivalent refractive error from -5.29 ± 2.47 diopters (D and -5.54 ± 5.04 D preoperatively to -1.47 ± 0.71 D and -0.74 ± 1.07 D (P=0.001, P=0.002, respectively, at 1 year. In the same period, the mean K- readings improved from 47.93 ± 4.84 D to 40.87 ± 2.36 D (P=0.002, and the mean ISAI improved from 5.34 ± 3.05 to 2.37 ± 1.68 (P=0.003. No significant changes in mean central corneal thickness were observed postoperatively. There were no major complications during or after surgery. Conclusion: ICRS implantation using a unique mechanical dissection technique is a safe and effective treatment for post-LASIK ectasia. All parameters showed improvement at 1-year follow-up.

  19. Computed tomography landmark-based semi-automated mesh morphing and mapping techniques: generation of patient specific models of the human pelvis without segmentation.

    Science.gov (United States)

    Salo, Zoryana; Beek, Maarten; Wright, David; Whyne, Cari Marisa

    2015-04-13

    Current methods for the development of pelvic finite element (FE) models generally are based upon specimen specific computed tomography (CT) data. This approach has traditionally required segmentation of CT data sets, which is time consuming and necessitates high levels of user intervention due to the complex pelvic anatomy. The purpose of this research was to develop and assess CT landmark-based semi-automated mesh morphing and mapping techniques to aid the generation and mechanical analysis of specimen-specific FE models of the pelvis without the need for segmentation. A specimen-specific pelvic FE model (source) was created using traditional segmentation methods and morphed onto a CT scan of a different (target) pelvis using a landmark-based method. The morphed model was then refined through mesh mapping by moving the nodes to the bone boundary. A second target model was created using traditional segmentation techniques. CT intensity based material properties were assigned to the morphed/mapped model and to the traditionally segmented target models. Models were analyzed to evaluate their geometric concurrency and strain patterns. Strains generated in a double-leg stance configuration were compared to experimental strain gauge data generated from the same target cadaver pelvis. CT landmark-based morphing and mapping techniques were efficiently applied to create a geometrically multifaceted specimen-specific pelvic FE model, which was similar to the traditionally segmented target model and better replicated the experimental strain results (R(2)=0.873). This study has shown that mesh morphing and mapping represents an efficient validated approach for pelvic FE model generation without the need for segmentation.

  20. Computer-aided diagnosis: a 3D segmentation method for lung nodules in CT images by use of a spiral-scanning technique

    Science.gov (United States)

    Wang, Jiahui; Engelmann, Roger; Li, Qiang

    2008-03-01

    Lung nodule segmentation in computed tomography (CT) plays an important role in computer-aided detection, diagnosis, and quantification systems for lung cancer. In this study, we developed a simple but accurate nodule segmentation method in three-dimensional (3D) CT. First, a volume of interest (VOI) was determined at the location of a nodule. We then transformed the VOI into a two-dimensional (2D) image by use of a "spiral-scanning" technique, in which a radial line originating from the center of the VOI spirally scanned the VOI. The voxels scanned by the radial line were arranged sequentially to form a transformed 2D image. Because the surface of a nodule in 3D image became a curve in the transformed 2D image, the spiral-scanning technique considerably simplified our segmentation method and enabled us to obtain accurate segmentation results. We employed a dynamic programming technique to delineate the "optimal" outline of a nodule in the 2D image, which was transformed back into the 3D image space to provide the interior of the nodule. The proposed segmentation method was trained on the first and was tested on the second Lung Image Database Consortium (LIDC) datasets. An overlap between nodule regions provided by computer and by the radiologists was employed as a performance metric. The experimental results on the LIDC database demonstrated that our segmentation method provided relatively robust and accurate segmentation results with mean overlap values of 66% and 64% for the nodules in the first and second LIDC datasets, respectively, and would be useful for the quantification, detection, and diagnosis of lung cancer.

  1. Organic Scintillators in Nonproliferation Applications With a Hybridized Double-Pulse Rejection Technique

    Science.gov (United States)

    Bourne, Mark Mitchell

    Alternative detection technologies are crucial to meeting demand for neutron detectors, for the current production of He-3, which has been the classical neutron choice, is insufficient. Organic scintillators are a strong candidate as a He-3 alternative due to their high efficiency, fast timing properties, and capabilities for separately identifying gamma-rays and neutrons through pulse shape discrimination (PSD). However, the use of organic scintillators in environments with numerous gamma rays can be limited because overlapping gamma-ray events can be misclassified as neutron events during PSD. To solve this problem, a new, hybridized double-pulse cleaning technique, consisting of three separate cleaning algorithms, was developed. The technique removes gamma-ray double pulses while preserving as many neutron pulses as possible. This technique was applied to separate experiments of Cf-252 and a gamma-ray source when measuring at a 100-kHz count rate and a field of 1000 incident gamma rays per incident neutron. It was found that stilbene scintillators were capable of intrinsic neutron efficiencies between 15-19% when measuring bare Cf-252 and 13-17% when exposed to the gamma-ray field. Misclassification rates ranged from 10-6-10-5, a factor-of-5 better than both the EJ-309 liquid and BB3-5 plastic. Next, plutonium experiments were performed with stilbene to determine which cleaning algorithm was best for each sample. A clear correlation was found that related the correct method of cleaning to the measured gamma ray-to-neutron ratio. When the measured gamma ray-to-neutron ratio is 10 or below, the template cleaning algorithm is preferred, while the fractional and hybrid cleaning algorithms are preferred when the gamma ray-to-neutron ratio is 100 or greater. Discriminating neutron sources such as Cf-252 or AmLi from SNM samples such as plutonium is a top priority in nonproliferation. We demonstrate that time-correlated experiments, utilizing both PSD-capable plastic

  2. A Discrete Wavelet Based Feature Extraction and Hybrid Classification Technique for Microarray Data Analysis

    Directory of Open Access Journals (Sweden)

    Jaison Bennet

    2014-01-01

    Full Text Available Cancer classification by doctors and radiologists was based on morphological and clinical features and had limited diagnostic ability in olden days. The recent arrival of DNA microarray technology has led to the concurrent monitoring of thousands of gene expressions in a single chip which stimulates the progress in cancer classification. In this paper, we have proposed a hybrid approach for microarray data classification based on nearest neighbor (KNN, naive Bayes, and support vector machine (SVM. Feature selection prior to classification plays a vital role and a feature selection technique which combines discrete wavelet transform (DWT and moving window technique (MWT is used. The performance of the proposed method is compared with the conventional classifiers like support vector machine, nearest neighbor, and naive Bayes. Experiments have been conducted on both real and benchmark datasets and the results indicate that the ensemble approach produces higher classification accuracy than conventional classifiers. This paper serves as an automated system for the classification of cancer and can be applied by doctors in real cases which serve as a boon to the medical community. This work further reduces the misclassification of cancers which is highly not allowed in cancer detection.

  3. Fish recognition based on the combination between robust feature selection, image segmentation and geometrical parameter techniques using Artificial Neural Network and Decision Tree

    CERN Document Server

    Alsmadi, Mutasem Khalil Sari; Noah, Shahrul Azman; Almarashdah, Ibrahim

    2009-01-01

    We presents in this paper a novel fish classification methodology based on a combination between robust feature selection, image segmentation and geometrical parameter techniques using Artificial Neural Network and Decision Tree. Unlike existing works for fish classification, which propose descriptors and do not analyze their individual impacts in the whole classification task and do not make the combination between the feature selection, image segmentation and geometrical parameter, we propose a general set of features extraction using robust feature selection, image segmentation and geometrical parameter and their correspondent weights that should be used as a priori information by the classifier. In this sense, instead of studying techniques for improving the classifiers structure itself, we consider it as a black box and focus our research in the determination of which input information must bring a robust fish discrimination.The main contribution of this paper is enhancement recognize and classify fishes...

  4. A Polar Fuzzy Control Scheme for Hybrid Power System Using Vehicle-To-Grid Technique

    Directory of Open Access Journals (Sweden)

    Mohammed Elsayed Lotfy

    2017-07-01

    Full Text Available A novel polar fuzzy (PF control approach for a hybrid power system is proposed in this research. The proposed control scheme remedies the issues of system frequency and the continuity of demand supply caused by renewable sources’ uncertainties. The hybrid power system consists of a wind turbine generator (WTG, solar photovoltaics (PV, a solar thermal power generator (STPG, a diesel engine generator (DEG, an aqua-electrolyzer (AE, an ultra-capacitor (UC, a fuel-cell (FC, and a flywheel (FW. Furthermore, due to the high cost of the battery energy storage system (BESS, a new idea of vehicle-to-grid (V2G control is applied to use the battery of the electric vehicle (EV as equivalent to large-scale energy storage units instead of small batteries to improve the frequency stability of the system. In addition, EV customers’ convenience is taken into account. A minimal-order observer is used to estimate the supply error. Then, the area control error (ACE signal is calculated in terms of the estimated supply error and the frequency deviation. ACE is considered in the frequency domain. Two PF approaches are utilized in the intended system. The mission of each controller is to mitigate one frequency component of ACE. The responsibility for ACE compensation is shared among all parts of the system according to their speed of response. The performance of the proposed control scheme is compared to the conventional fuzzy logic control (FLC. The effectiveness and robustness of the proposed control technique are verified by numerical simulations under various scenarios.

  5. Diagnostic accuracy: theoretical models for preimplantation genetic testing of a single nucleus using the fluorescence in situ hybridization technique

    NARCIS (Netherlands)

    P.N. Scriven; P.M.M. Bossuyt

    2010-01-01

    The aim of this study was to develop and use theoretical models to investigate the accuracy of the fluorescence in situ hybridization (FISH) technique in testing a single nucleus from a preimplantation embryo without the complicating effect of mosaicism. Mathematical models were constructed for thre

  6. Proliferation of endothelial cells on the plasma-treated segmented-polyurethane surface: attempt of construction of a small caliber hybrid vascular graft and antithrombogenicity.

    Science.gov (United States)

    Kaibara; Takahashi; Kurotobi; Suzuki

    2000-12-30

    To prepare a porous segmented-polyurethane (SPU) tube, a solution of SPU containing different concentrations of NaCl was coated on a glass rod and the coated SPU was immediately immersed in water. When the surface of the porous SPU, where bovine aortic endothelial cells are not normally capable of adhering and proliferating, was modified by plasma treatment, the proliferation of endothelial cells could be drastically improved. The cells proliferated confluently on the porous SPU surface prepared at low concentrations of NaCl below 10 g per 100 ml, but poorly on the porous surface prepared at high concentrations of NaCl. The construction of a hybrid vascular graft consisting of a porous SPU tube (2 mm in inner diameter, 5 cm in length) and endothelial cells was attempted. The cells cultured on the inner surface of the tube proliferated to confluency everywhere. From an in vitro antithrombogenic evaluation test, which involved the use of human blood, the present hybrid graft can be considered to provide an inert surface against thrombus formation and blood coagulation. Negligible changes in shape of human leukocytes in contact with bovine aortic endothelial cell surface occurred, suggesting that the bovine aortic endothelial cells used are immunologically less active against human blood.

  7. Silica/polyacrylonitrile hybrid nanofiber membrane separators via sol-gel and electrospinning techniques for lithium-ion batteries

    Science.gov (United States)

    Yanilmaz, Meltem; Lu, Yao; Zhu, Jiadeng; Zhang, Xiangwu

    2016-05-01

    Silica/polyacrylonitrile (SiO2/PAN) hybrid nanofiber membranes were fabricated by using sol-gel and electrospinning techniques and their electrochemical performance was evaluated for use as separators in lithium-ion batteries. The aim of this study was to design high-performance separator membranes with enhanced electrochemical performance and good thermal stability compared to microporous polyolefin membranes. In this study, SiO2 nanoparticle content up to 27 wt% was achieved in the membranes by using sol-gel technique. It was found that SiO2/PAN hybrid nanofiber membranes had superior electrochemical performance with good thermal stability due to their high SiO2 content and large porosity. Compared with commercial microporous polyolefin membranes, SiO2/PAN hybrid nanofiber membranes had larger liquid electrolyte uptake, higher electrochemical oxidation limit, and lower interfacial resistance with lithium. SiO2/PAN hybrid nanofiber membranes with different SiO2 contents (0, 16, 19 and 27 wt%) were also assembled into lithium/lithium iron phosphate cells, and high cell capacities and good cycling performance were demonstrated at room temperature. In addition, cells using SiO2/PAN hybrid nanofiber membranes with high SiO2 contents showed superior C-rate performance compared to those with low SiO2 contents and commercial microporous polyolefin membrane.

  8. A Hybrid Technique for Real Time License Plate Localization with the aid of FFBPNNAPSO

    Directory of Open Access Journals (Sweden)

    Reji PI

    2016-04-01

    Full Text Available Vehicle License Plate Recognition (VLPR is an imperative constituent in Intelligent Transportation Systems (ITS, which encircles three foremost phases essentially License Plate Localization (LPL, Character Segmentation (CS, Character Recognition (CR. In this paper, we have intended to introduce a novel License Plate Localization algorithm subjected to Artificial Neural Networks (ANN. This proposed scheme involves distinct phases of pre-processing, image de-noising and enhancement, feature extraction, Neural Network training and License Plate detection. Followed by the mining of assorted statistical features, geometrical features, edge features and texture features from the vehicular image, they are given as the input to Feed Forward Back Propagation Neural Network (FFBPNN in order to localize the License Plate. During the training process, the parameters of the FFBPNN will be optimized using the eminent Adaptive Particle Swarm Optimization (APSO algorithm in order to improve the Neural Network convergence performance. The License Plate Localization of our proposed technique is analyzed with simple Feed Forward Back propagation Neural Network (FFBPNN in terms of accuracy, sensitivity and specificity. The experimental outcomes demonstrate that the proposed procedure proficiently accomplishes an extremely high localization rate with elevated specificity (91.3%.

  9. A novel hybrid meta-heuristic technique applied to the well-known benchmark optimization problems

    Science.gov (United States)

    Abtahi, Amir-Reza; Bijari, Afsane

    2016-09-01

    In this paper, a hybrid meta-heuristic algorithm, based on imperialistic competition algorithm (ICA), harmony search (HS), and simulated annealing (SA) is presented. The body of the proposed hybrid algorithm is based on ICA. The proposed hybrid algorithm inherits the advantages of the process of harmony creation in HS algorithm to improve the exploitation phase of the ICA algorithm. In addition, the proposed hybrid algorithm uses SA to make a balance between exploration and exploitation phases. The proposed hybrid algorithm is compared with several meta-heuristic methods, including genetic algorithm (GA), HS, and ICA on several well-known benchmark instances. The comprehensive experiments and statistical analysis on standard benchmark functions certify the superiority of the proposed method over the other algorithms. The efficacy of the proposed hybrid algorithm is promising and can be used in several real-life engineering and management problems.

  10. A novel hybrid meta-heuristic technique applied to the well-known benchmark optimization problems

    Science.gov (United States)

    Abtahi, Amir-Reza; Bijari, Afsane

    2017-09-01

    In this paper, a hybrid meta-heuristic algorithm, based on imperialistic competition algorithm (ICA), harmony search (HS), and simulated annealing (SA) is presented. The body of the proposed hybrid algorithm is based on ICA. The proposed hybrid algorithm inherits the advantages of the process of harmony creation in HS algorithm to improve the exploitation phase of the ICA algorithm. In addition, the proposed hybrid algorithm uses SA to make a balance between exploration and exploitation phases. The proposed hybrid algorithm is compared with several meta-heuristic methods, including genetic algorithm (GA), HS, and ICA on several well-known benchmark instances. The comprehensive experiments and statistical analysis on standard benchmark functions certify the superiority of the proposed method over the other algorithms. The efficacy of the proposed hybrid algorithm is promising and can be used in several real-life engineering and management problems.

  11. A hybrid PSO technique for procuring VAR ancillary service in the deregulated electricity markets

    Energy Technology Data Exchange (ETDEWEB)

    El-Araby, E.E. [Department of Electrical Engineering, Suez Canal University (Egypt); Yorino, Naoto [Department of Artificial Complex Systems Engineering, Hiroshima University (Japan)

    2010-07-15

    This paper develops a new market-based technique for acquiring VAR ancillary service in the electricity market. The main objective of the developed market is to enable transmission operator ''TO'' to procure VAR service in a long term contract from the critical VAR providers that satisfy minimum VAR service payment while maintaining system security. Reactive power control problem for voltage stability is introduced into the VAR market problem in an explicit manner for normal and emergency states. An integration of particle swarm optimization ''PSO'' is presented with successive linear programming ''SLP'' for dealing with the VAR ancillary service problem. The problem is formulated as a large-scale nonlinear constrained optimization problem with a non-differentiable objective function representing VAR payment and operational costs. This type of problem is hard to be treated straightforwardly by the classical optimization methods. Therefore, we propose here a two-layer hybrid PSO/SLP approach, which is suited for carrying out the difficulties associated with non-differentiable and discontinuous objective functions. The proposed method has been examined on the standard IEEE 57 bus-system and compared with GA/SLP method to demonstrate its capability. (author)

  12. Optimization of RF power absorption by optimization techniques using the lower hybrid current drive of FTU

    Energy Technology Data Exchange (ETDEWEB)

    Centioli, C. [Associazione Euratom/ENEA Sulla Fusione, Centro Ricerche Frascati, Via E. Fermi 45, CP 65, 00044 Frascati, Rome (Italy); Iannone, F. [Associazione Euratom/ENEA Sulla Fusione, Centro Ricerche Frascati, Via E. Fermi 45, CP 65, 00044 Frascati, Rome (Italy); Mazza, G. [Associazione Euratom/ENEA Sulla Fusione, Centro Ricerche Frascati, Via E. Fermi 45, CP 65, 00044 Frascati, Rome (Italy); Panella, M. [Associazione Euratom/ENEA Sulla Fusione, Centro Ricerche Frascati, Via E. Fermi 45, CP 65, 00044 Frascati, Rome (Italy); Pangione, L. [Dipartimento di Informatica, Sistemi e Produzione, Universita di Roma, Tor Vergata, Via del Politecnico 1, 00133 Rome (Italy)]. E-mail: pangione@frascati.enea.it; Podda, S. [Associazione Euratom/ENEA Sulla Fusione, Centro Ricerche Frascati, Via E. Fermi 45, CP 65, 00044 Frascati, Rome (Italy); Tuccillo, A. [Associazione Euratom/ENEA Sulla Fusione, Centro Ricerche Frascati, Via E. Fermi 45, CP 65, 00044 Frascati, Rome (Italy); Vitale, V. [Associazione Euratom/ENEA Sulla Fusione, Centro Ricerche Frascati, Via E. Fermi 45, CP 65, 00044 Frascati, Rome (Italy); Zaccarian, L. [Dipartimento di Informatica, Sistemi e Produzione, Universita di Roma, Tor Vergata, Via del Politecnico 1, 00133 Rome (Italy)

    2005-11-15

    In this paper, we will report on the experimental results arising from the implementation of optimization techniques to maximize the RF power coupling versus the plasma conditions in the FTU experimental facility. These experiments are carried out by employing the open-source Linux-RTAI control system currently running on the FTU digital feedback loop. The RF power source under consideration is a lower hybrid system (LH) based on six gyrotrons with a nominal power output capability of 1.1 MW each. The optimization of the coupling level between the plasma and the emitting antenna reduces the reflected power, thus maximizing the heating effects in addition to avoiding danger to the emitter (equivalently, annoying safety shutdowns of the system). To this aim, the plasma displacement is modified by suitably adjusting the reference input to the stabilizing feedback, according to a steepest descent algorithm. It will be shown in the paper how this algorithm achieves a satisfactory level of robustness with respect to measurement errors and well performs both in simulation and in experimental tests, thus leading to an improved effectiveness of the RF heating system.

  13. Hybrid LS-LMMSE Channel Estimation Technique for LTE Downlink Systems

    CERN Document Server

    Khlifi, Abdelhakim; 10.5121/ijngn.2011.3401

    2012-01-01

    In this paper, we propose to improve the performance of the channel estimation for LTE Downlink systems under the effect of the channel length. As LTE Downlink system is a MIMO-OFDMA based system, a cyclic prefix (CP) is inserted at the beginning of each transmitted OFDM symbol in order to mitigate both inter-carrier interference (ICI) and inter-symbol interference (ISI). The inserted CP is usually equal to or longer than the channel length. However, the cyclic prefix can be shorter because of some unforeseen channel behaviour. Previous works have shown that in the case where the cyclic prefix is equal to or longer than the channel length, LMMSE performs better than LSE but at the cost of computational complexity .In the other case, LMMSE performs also better than LS only for low SNR values. However, LS shows better performance for LTE Downlink systems for high SNR values. Therefore, we propose a hybrid LS-LMMSE channel estimation technique robust to the channel length effect. MATLAB Monte-Carlo simulations a...

  14. Power Management Based Current Control Technique for Photovoltaic-Battery Assisted Wind-Hydro Hybrid System

    Science.gov (United States)

    Ram Prabhakar, J.; Ragavan, K.

    2013-07-01

    This article proposes new power management based current control strategy for integrated wind-solar-hydro system equipped with battery storage mechanism. In this control technique, an indirect estimation of load current is done, through energy balance model, DC-link voltage control and droop control. This system features simpler energy management strategy and necessitates few power electronic converters, thereby minimizing the cost of the system. The generation-demand (G-D) management diagram is formulated based on the stochastic weather conditions and demand, which would likely moderate the gap between both. The features of management strategy deploying energy balance model include (1) regulating DC-link voltage within specified tolerances, (2) isolated operation without relying on external electric power transmission network, (3) indirect current control of hydro turbine driven induction generator and (4) seamless transition between grid-connected and off-grid operation modes. Furthermore, structuring of the hybrid system with appropriate selection of control variables enables power sharing among each energy conversion systems and battery storage mechanism. By addressing these intricacies, it is viable to regulate the frequency and voltage of the remote network at load end. The performance of the proposed composite scheme is demonstrated through time-domain simulation in MATLAB/Simulink environment.

  15. Development of automatic surveillance of animal behaviour and welfare using image analysis and machine learned segmentation technique.

    Science.gov (United States)

    Nilsson, M; Herlin, A H; Ardö, H; Guzhva, O; Åström, K; Bergsten, C

    2015-11-01

    In this paper the feasibility to extract the proportion of pigs located in different areas of a pig pen by advanced image analysis technique is explored and discussed for possible applications. For example, pigs generally locate themselves in the wet dunging area at high ambient temperatures in order to avoid heat stress, as wetting the body surface is the major path to dissipate the heat by evaporation. Thus, the portion of pigs in the dunging area and resting area, respectively, could be used as an indicator of failure of controlling the climate in the pig environment as pigs are not supposed to rest in the dunging area. The computer vision methodology utilizes a learning based segmentation approach using several features extracted from the image. The learning based approach applied is based on extended state-of-the-art features in combination with a structured prediction framework based on a logistic regression solver using elastic net regularization. In addition, the method is able to produce a probability per pixel rather than form a hard decision. This overcomes some of the limitations found in a setup using grey-scale information only. The pig pen is a difficult imaging environment because of challenging lighting conditions like shadows, poor lighting and poor contrast between pig and background. In order to test practical conditions, a pen containing nine young pigs was filmed from a top view perspective by an Axis M3006 camera with a resolution of 640 × 480 in three, 10-min sessions under different lighting conditions. The results indicate that a learning based method improves, in comparison with greyscale methods, the possibility to reliable identify proportions of pigs in different areas of the pen. Pigs with a changed behaviour (location) in the pen may indicate changed climate conditions. Changed individual behaviour may also indicate inferior health or acute illness.

  16. Validation of a low-dose hybrid RSA and fluoroscopy technique: Determination of accuracy, bias and precision.

    Science.gov (United States)

    Ioppolo, James; Börlin, Niclas; Bragdon, Charles; Li, Mingguo; Price, Roger; Wood, David; Malchau, Henrik; Nivbrant, Bo

    2007-01-01

    Analyzing skeletal kinematics with radiostereometric analysis (RSA) following corrective orthopedic surgery allows the quantitative comparison of different implant designs. The purpose of this study was to validate a technique for dynamically estimating the relative position and orientation of skeletal segments using RSA and single plane X-ray fluoroscopy. Two micrometer-based in vitro phantom models of the skeletal segments in the hip and knee joints were used. The spatial positions of tantalum markers that were implanted into each skeletal segment were reconstructed using RSA. The position and orientation of each segment were determined in fluoroscopy images by minimizing the difference between the markers measured and projected in the image plane. Accuracy was determined in terms of bias and precision by analyzing the deviation between the applied displacement protocol and measured pose estimates. Measured translational accuracy was less than 100 microm parallel to the image plane and less than 700 microm in the direction orthogonal to the image plane. The measured rotational error was less than 1 degrees . Measured translational and rotational bias was not statistically significant at the 95% level of confidence. The technique allows real-time kinematic skeletal measurements to be performed on human subjects implanted with tantalum markers for quantitatively measuring the motion of normal joints and different implant designs.

  17. Fingerprint segmentation: an investigation of various techniques and a parameter study of a variance-based method

    CSIR Research Space (South Africa)

    Msiza, IS

    2011-09-01

    Full Text Available Fingerprint image segmentation plays an important role in any fingerprint image analysis implementation and it should, ideally, be executed during the initial stages of a fingerprint manipulation process. After careful consideration of various...

  18. Hybrid soft computing approaches research and applications

    CERN Document Server

    Dutta, Paramartha; Chakraborty, Susanta

    2016-01-01

    The book provides a platform for dealing with the flaws and failings of the soft computing paradigm through different manifestations. The different chapters highlight the necessity of the hybrid soft computing methodology in general with emphasis on several application perspectives in particular. Typical examples include (a) Study of Economic Load Dispatch by Various Hybrid Optimization Techniques, (b) An Application of Color Magnetic Resonance Brain Image Segmentation by ParaOptiMUSIG activation Function, (c) Hybrid Rough-PSO Approach in Remote Sensing Imagery Analysis,  (d) A Study and Analysis of Hybrid Intelligent Techniques for Breast Cancer Detection using Breast Thermograms, and (e) Hybridization of 2D-3D Images for Human Face Recognition. The elaborate findings of the chapters enhance the exhibition of the hybrid soft computing paradigm in the field of intelligent computing.

  19. Performance improvement of hybrid subcarrier multiplexing optical spectrum code division multiplexing system using spectral direct decoding detection technique

    Science.gov (United States)

    Sahbudin, R. K. Z.; Abdullah, M. K.; Mokhtar, M.

    2009-06-01

    This paper proposes a hybrid subcarrier multiplexing/optical spectrum code division multiplexing (SCM/OSCDM) system for the purpose of combining the advantages of both techniques. Optical spectrum code division multiple-access (OSCDMA) is one of the multiplexing techniques that is becoming popular because of the flexibility in the allocation of channels, ability to operate asynchronously, enhanced privacy and increased capacity in bursty nature networks. On the other hand, subcarrier multiplexing (SCM) technique is able to enhance the channel data rate of OSCDMA systems. In this paper, a newly developed detection technique for the OSCDM called spectral direct decoding (SDD) detection technique is compared mathematically with the AND subtraction detection technique. The system utilizes a new unified code construction named KS (Khazani-Syed) code. The results characterizing the bit-error-rate (BER) show that SDD offers a significant improved performance at BER of 10 -9.

  20. Growth of segmented gold nanorods with nanogaps by the electrochemical wet etching technique for single-electron transistor applications.

    Science.gov (United States)

    Van Hoang, Nguyen; Kumar, Sanjeev; Kim, Gil-Ho

    2009-03-25

    The growth of multisegment nanorods comprising gold (Au) and sacrificial silver (Ag) segments (Au-Ag-Au or Au-Ag-Au-Ag-Au) using the electrochemical wet etching method is reported. The nanorods were fabricated using an alumina template of thickness 100 microm and pore size of 200 nm. A variety of nanorods from single to seven segments comprising alternate Au and Ag segments were fabricated with better control of growth rate. The multisegment nanorods were selectively etched by removing the Ag segments to create gaps in the fabricated nanorods. A careful investigation led to the creation of a wide variety of nanogaps in the fabricated multisegment nanorods. The size of the nanogap was controlled by the passage of current through the electrochemical process, and size below 10 nm was achievable at exchanged charges of approximately 1 mC. A further lowering in the size of nanogaps was achieved by diluting the silver plating solution and a segmented nanorod with nanogap (Au-nanogap-Au) of 3.8 nm at exchanged charges of 0.2 mC was successfully created. In addition, segmented nanorods with two or more nanogaps (Au-nanogap-Au-nanogap-Ag) placed symmetrically and asymmetrically on either side of the central Au segments were also created. A prototype of a single-electron transistor device based on segmented nanorods with two nanogaps is proposed. The results obtained could form the basis for the realization of quantum tunneling devices where the barrier thickness is very critical and demands values less than 5 nm. The encouraging results show the promise of multisegment nanorods for fabricating devices working at the de Broglie wavelength such as single-electron transistors.

  1. 手腕骨三维图像分割方法%A 3D Segmentation Technique for Carpal Bone Images

    Institute of Scientific and Technical Information of China (English)

    李晶; 赵海燕

    2013-01-01

    Targeted at kinematic analysis of the carpal bones and design of fracture fixation for corresponding surgeries, this paper proposes a 3D (Three-Dimensional) technique for segmentation of the carpal bone images on the basis of the spatial position, which contributes to independent investigation of each segmented carpal bone on kinematic features and load-carrying capabilities under different circumstances. As a new segmentation technique in diagnosis and treatment of carpal bone diseases, it can divide the carpal bone images into eight segments that are available separately for review, conifguration, analysis and measurement.%为了对手腕骨进行运动学分析并对骨折手术固定辅助设计,本文提出一种对手腕骨的三维分割方法,即采用基于空间位置的方法将手腕骨独立分开,以便独立研究各部分在不同情况下的运动与受力。该方法将手腕8块腕骨分割开来,并能独立显示控制测量。为手腕骨疾病的诊断治疗提供,新的技术方法。

  2. Research for color image segmentation based on hybrid clustering%混合聚类彩色图像分割方法研究

    Institute of Scientific and Technical Information of China (English)

    施海滨; 周勇

    2011-01-01

    提出了一种基于K-均值算法和EM算法混合聚类的彩色图像分割方法.首先将待分割的RGB彩色图像转化成YUV空间模型,然后将该图像分割成n小块,对每个块的颜色分量用改进的K-均值聚类算法进行聚类分析,最后用EM聚类算法对每个块进行聚类,分割源图像.对K-均值算法和EM算法的初始聚类中心引进了改进算法,加快了算法的收敛速度.并与相似的分割方法进行了比较实验,给出了详细的实验结果与分析.实验表明该方法分割速度快,效果好,具有较高的实用价值.%A new color image segmentation algorithm is introduced based on hybrid clustering including K-means algorithm and EM algorithm, which firstly converts RGB color image into YUV-Space model, and then divides the whole image to n-blocks,clusters the color components of each block with K-means improved in this paper,and finally,segments the source image by clustering each block with EM clustering algorithm.In this paper,a new method is proposed to set initial cluster centers in K-means algorithm and EM algorithm, accelerates the convergence speed.The experiment results and the comparison results with similar approach are provided.Experiment results show the proposed algorithm is effective and has high practical value.

  3. Assessing the transferability of a hybrid Taguchi-objective function method to optimize image segmentation for detecting and counting cave roosting birds using terrestrial laser scanning data

    Science.gov (United States)

    Idrees, Mohammed Oludare; Pradhan, Biswajeet; Buchroithner, Manfred F.; Shafri, Helmi Zulhaidi Mohd; Khairunniza Bejo, Siti

    2016-07-01

    As far back as early 15th century during the reign of the Ming Dynasty (1368 to 1634 AD), Gomantong cave in Sabah (Malaysia) has been known as one of the largest roosting sites for wrinkle-lipped bats (Chaerephon plicata) and swiftlet birds (Aerodramus maximus and Aerodramus fuciphagus) in very large colonies. Until recently, no study has been done to quantify or estimate the colony sizes of these inhabitants in spite of the grave danger posed to this avifauna by human activities and potential habitat loss to postspeleogenetic processes. This paper evaluates the transferability of a hybrid optimization image analysis-based method developed to detect and count cave roosting birds. The method utilizes high-resolution terrestrial laser scanning intensity image. First, segmentation parameters were optimized by integrating objective function and the statistical Taguchi methods. Thereafter, the optimized parameters were used as input into the segmentation and classification processes using two images selected from Simud Hitam (lower cave) and Simud Putih (upper cave) of the Gomantong cave. The result shows that the method is capable of detecting birds (and bats) from the image for accurate population censusing. A total number of 9998 swiftlet birds were counted from the first image while 1132 comprising of both bats and birds were obtained from the second image. Furthermore, the transferability evaluation yielded overall accuracies of 0.93 and 0.94 (area under receiver operating characteristic curve) for the first and second image, respectively, with p value of <0.0001 at 95% confidence level. The findings indicate that the method is not only efficient for the detection and counting cave birds for which it was developed for but also useful for counting bats; thus, it can be adopted in any cave.

  4. A hybrid conformal planning technique with solitary dynamic portal for postmastectomy radiotherapy with regional nodes

    Directory of Open Access Journals (Sweden)

    K Mohamathu Rafic

    2017-01-01

    Full Text Available Purpose: This study focuses on incorporation of a solitary dynamic portal (SDP in conformal planning for postmastectomy radiotherapy (PMRT with nodal regions with an intention to overcome the treatment planning limitations imposed by conventional techniques. Materials and Methods: Twenty-four patients who underwent surgical mastectomy followed by PMRT were included in this study. Initially, a treatment plan comprising tangential beams fitted to beam's-eye-view (BEV of chest wall (CW and a direct anterior field fitted to BEV of nodal region, both sharing a single isocenter was generated using Eclipse treatment planning system. Multiple field-in-fields with optimum beam weights (5% per field were added primarily from the medial tangent, fitted to BEV of entire target volume, and finally converted into a dynamic portal. Dosimetric analysis for the treatment plans and fluence verification for the dynamic portals were performed. Results and Discussion: Conformal plans with SDP showed excellent dose coverage (V95%>95%, higher degree of tumor dose conformity (≤1.25 and homogeneity (≤0.12 without compromising the organ at risk sparing for PMRT with nodal region. Treatment plans with SDP considerably reduced the lower isodose spread to the ipsilateral lung, heart, and healthy tissue without affecting the dose homogeneity. Further, gamma evaluation showed more than 96% pixel pass rate for standard 3%/3 mm dose difference and distance-to-agreement criteria. Moreover, this plan offers less probability of “geometrical miss” at the highly irregular CW with regional nodal radiotherapy. Conclusion: Hybrid conformal plans with SDP would facilitate improved dose distribution and reduced uncertainty in delivery and promises to be a suitable treatment option for complex postmastectomy CW with regional nodal irradiation.

  5. Passive hybrid technique for the vibration mitigation of systems of interconnected stays

    Science.gov (United States)

    Caracoglia, Luca; Jones, Nicholas P.

    2007-11-01

    The problem of stay oscillation mitigation in cable-stayed bridges, usually induced by wind or wind and rain, may require the introduction of passive devices, such as dampers on individual stays or the use of transverse restrainers (cross-ties). The damper performance is often affected by the geometrical constraints of the bridge deck that limit the installation of such devices to locations very close to the end of the cable. On the other hand, cross-ties are generally incapable of direct energy dissipation. Therefore, the authors have proposed and analyzed a hybrid passive system in which the advantages of both techniques are applied to the oscillation mitigation of complex interconnected systems with multiple external dampers at the deck level, in correspondence with the cross-tie lines. This paper summarizes the relevant findings of a research program involving the authors' efforts focused on the in-plane free-vibration analysis of stay-cable systems. This research is also based upon some recent results associated with the analytical solution of a taut-cable with two attached viscous dampers. These findings are initially extended to a simplified network with reduced number of connectors and one damper, for which the derivation of analytical solution is still possible. Subsequently, an existing multistay multidamped arrangement on a real bridge is considered, in which a fully numerical approach is required. The modal behavior is compared to the simplified examples, also enabling the interpretation of the results in the context of more general guidelines for potential future application.

  6. Prediction of monthly regional groundwater levels through hybrid soft-computing techniques

    Science.gov (United States)

    Chang, Fi-John; Chang, Li-Chiu; Huang, Chien-Wei; Kao, I.-Feng

    2016-10-01

    Groundwater systems are intrinsically heterogeneous with dynamic temporal-spatial patterns, which cause great difficulty in quantifying their complex processes, while reliable predictions of regional groundwater levels are commonly needed for managing water resources to ensure proper service of water demands within a region. In this study, we proposed a novel and flexible soft-computing technique that could effectively extract the complex high-dimensional input-output patterns of basin-wide groundwater-aquifer systems in an adaptive manner. The soft-computing models combined the Self Organized Map (SOM) and the Nonlinear Autoregressive with Exogenous Inputs (NARX) network for predicting monthly regional groundwater levels based on hydrologic forcing data. The SOM could effectively classify the temporal-spatial patterns of regional groundwater levels, the NARX could accurately predict the mean of regional groundwater levels for adjusting the selected SOM, the Kriging was used to interpolate the predictions of the adjusted SOM into finer grids of locations, and consequently the prediction of a monthly regional groundwater level map could be obtained. The Zhuoshui River basin in Taiwan was the study case, and its monthly data sets collected from 203 groundwater stations, 32 rainfall stations and 6 flow stations during 2000 and 2013 were used for modelling purpose. The results demonstrated that the hybrid SOM-NARX model could reliably and suitably predict monthly basin-wide groundwater levels with high correlations (R2 > 0.9 in both training and testing cases). The proposed methodology presents a milestone in modelling regional environmental issues and offers an insightful and promising way to predict monthly basin-wide groundwater levels, which is beneficial to authorities for sustainable water resources management.

  7. 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 analy

  8. A review of the hybrid techniques for the fabrication of hard magnetic microactuators based on bonded magnetic powders

    Science.gov (United States)

    Pallapa, M.; Yeow, J. T. W.

    2015-02-01

    Polymer composites based on permanent magnetic bonded powders exhibit immense potential for applications in microactuators and sensors with magnetic performances comparable to their fully dense counterparts. While fabrication and integration of magnetic devices based on bonded magnetic powders is challenging via conventional deposition and electrochemical growth techniques, hybrid fabrication offers a promising alternative. This paper presents the evolution of permanent magnetic materials into bonded magnetic powders, the magnetic performance figures of merit of permanent magnetic materials significant for the design and manufacture of polymer based sensors and actuators. A review of the hybrid fabrication techniques such as replica molding, squeegee coating, spin casting etc are reported. Critical factors affecting the fabrication of polymer magnetic composites such as filler particle size and effect of magnetic field during fabrication are discussed. Prior art based on polymer magnetic composites for the fabrication of hard magnetic films and hard magnetic actuators are presented.

  9. Mixed potential integral equation technique for hybrid microstrip-slotline multilayered circuits using a mixed rectangular-triangular mesh

    Science.gov (United States)

    Sercu, Jeannick; Fache, Niels; Libbrecht, Frank; Lagasse, Paul

    1995-05-01

    In this paper, a mixed potential integral equation (MPIE) formulation for hybrid microstrip-slotline multilayered circuits is presented. This integral equation is solved with the method of moments (MoM) in combination with Galerkin's method. The vector-valued rooftop functions defined over a mixed rectangular-triangular mesh are used to model the electric and magnetic currents on the microstrip and slotline structures. An efficient calculation technique for the quadruple interaction integrals between two cells in the system matrix equation is presented. Two examples of hybrid microstrip-slotline circuits are discussed. The first example compares the simulation results for a microstrip-slotline transition with measured data. The second example illustrates the use of the simulation technique in the design process of a broadband slot-coupled microstrip line transition.

  10. A 3D hybrid grid generation technique and a multigrid/parallel algorithm based on anisotropic agglomeration approach

    Institute of Scientific and Technical Information of China (English)

    Zhang Laiping; Zhao Zhong; Chang Xinghua; He Xin

    2013-01-01

    A hybrid grid generation technique and a multigrid/parallel algorithm are presented in this paper for turbulence flow simulations over three-dimensional (3D) complex geometries.The hybrid grid generation technique is based on an agglomeration method of anisotropic tetrahedrons.Firstly,the complex computational domain is covered by pure tetrahedral grids,in which anisotropic tetrahedrons are adopted to discrete the boundary layer and isotropic tetrahedrons in the outer field.Then,the anisotropic tetrahedrons in the boundary layer are agglomerated to generate prismatic grids.The agglomeration method can improve the grid quality in boundary layer and reduce the grid quantity to enhance the numerical accuracy and efficiency.In order to accelerate the convergence history,a multigrid/parallel algorithm is developed also based on anisotropic agglomeration approach.The numerical results demonstrate the excellent accelerating capability of this multigrid method.

  11. The effectiveness of a high output/short duration radiofrequency current application technique in segmental pulmonary vein isolation for atrial fibrillation

    DEFF Research Database (Denmark)

    Nilsson, Brian; Chen, Xu; Pehrson, Steen;

    2006-01-01

    AIMS: Segmental pulmonary vein (PV) isolation by radiofrequency (RF) catheter ablation has become a curative therapy for atrial fibrillation (AF). However, the long procedure time limits the wide application of this procedure. The aim of the current study was to compare a novel ablation technique...... with a high power output and short application time vs. a conventional technique using a low power output and long application time. METHODS AND RESULTS: The study included 90 consecutive patients (age 53+/-10 years; 66 men). Segmental PV isolation was performed by irrigated RF catheter ablation in both...... groups. In the conventional group (Group 1, 45 patients), the power output was limited to 30 W with a target temperature of 50 degrees C and an RF preset duration of 120 s. In the novel group (Group 2, 45 patients), the maximum power output was preset to 45 W, with a target temperature of 55 degrees C...

  12. Staging of recurrent and advanced lung cancer with 18F-FDG PET in a coincidence technique (hybrid PET).

    Science.gov (United States)

    Schmid, R A; Hautmann, H; Poellinger, B; Kellner, W; Moisseev, A; Brinkbaeumer, K; Weiss, M; Hahn, K; Dresel, S

    2003-01-01

    The aim of this study was to evaluate [18F]fluorodeoxyglucose ( F-FDG) imaging of recurrent or inoperable lung cancer using a hybrid positron emission tomography (PET) device of the third generation. Examinations were compared with the results of conventional staging. Thirty-six patients suffering from recurrent or primarily inoperable lung cancer (29 men, seven women; age 64.8+/-12.0 years) were examined using hybrid PET (Marconi Axis gamma-PET ) 60 min after injection of 370 MBq F-FDG. The data obtained were reconstructed iteratively. All patients received a computed tomography (CT) scan using either the spiral or multislice technique. All lesions suspicious for primary or recurrent tumour were verified by biopsy; mediastinal lymph nodes were considered as malignant, when positive histology or a small axis diameter of greater than 1 cm measured with CT in addition to progression of clinical course was found. Distant metastases were diagnosed by CT and bone scintigraphy. Using hybrid PET all lesions showed a focally elevated glucose metabolism. Lymph node involvement of the ipsilateral peribronchial and hilar station (N1) was identified in 24/26 cases (92%), in 26/29 cases (90%) of ipsilateral central manifestation (N2) and in 11/13 (85%) cases of central contralateral or supraclavicular lymphatic infestation (N3). Pulmonary spread in hybrid PET was found in 4/8 cases (50%), whereas mainly lung metastases with a diameter of 1.5 cm and smaller were missed. Pleural involvement diagnosed by CT was verified in 4/5 patients. All four patients with bony metastases in conventional staging also presented with positive findings in hybrid PET (8/9 lesions). Concordance with conventional staging was found in 28/36 of patients (78%). In 4/36 patients (11%) unknown sites of tumour were detected leading to therapeutic consequences in three patients after radiological confirmation. Hybrid PET would have led to an understaging in four cases (11%), resulting theoretically in

  13. Ecophysiological Analysis of Microorganisms in Complex Microbial Systems by Combination of Fluorescence In Situ Hybridization with Extracellular Staining Techniques

    Science.gov (United States)

    Nielsen, Jeppe Lund; Kragelund, Caroline; Nielsen, Per Halkjær

    Ecophysiological analysis and functions of single cells in complex microbial systems can be examined by simple combinations of Fluorescence in situ hybridization (FISH) for identification with various staining techniques targeting functional phenotypes. In this chapter, we describe methods and protocols optimized for the study of extracellular enzymes, surface hydrophobicity and specific surface structures. Although primarily applied to the study of microbes in wastewater treatment (activated sludge and biofilms), the methods may also be used with minor modifications in several other ecosystems.

  14. POWER OPTIMIZED DATAPATH UNITS OF HYBRID EMBEDDED CORE ARCHITECTURE USING CLOCK GATING TECHNIQUE

    National Research Council Canada - National Science Library

    T.Subhashini; M.Kamaraju

    2015-01-01

    ...% of the total power dissipation. The main goal of this work is to implement a prototype power optimized datapath unit and ALU of Hybrid Embedded Controller Architecture targeted on to the FPGA chip and analyze the power consumption...

  15. RAPD Technique Used to Determine the Purity of Hybrid Hot Pepper Seeds

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Two hybrid hot pepper varieties Xiangyan 5 and Xiangyan 10, and their parents were analyzed the polymerase chain reaction with MJ /PT 200 Peltrier Themal Cycler and DS 800 White-ultravilot Transilluminator to set up a RAPD system adaptable to the purity determination of the hybrid seeds. Among the 39 random primers, 2 and 4 primers were found to be used effectively in Xiangyan 5 and Xiangyan 10 respectively.

  16. Optimisation Sizing of Hybrid Wind-Diesel Systems using Linear Programming Technique

    OpenAIRE

    Gan, Leong Kit; Shek, Jonathan; Mueller, Markus

    2014-01-01

    Despite the great potential of hybrid wind-diesel system in supplying energy to remote or island communities, sizing the system components have been a challenging problem for many project managers due to the reliance on various factors. This work considers utilising a fixed speed wind turbine (induction generator) in the hybrid system. It requires energy for start-up operation and this work takes into account for sizing the battery storage. In addition, the trade-off between the number of bat...

  17. Mechanical Fault Diagnosis of High Voltage Circuit Breakers with Unknown Fault Type Using Hybrid Classifier Based on LMD and Time Segmentation Energy Entropy

    Directory of Open Access Journals (Sweden)

    Nantian Huang

    2016-09-01

    Full Text Available In order to improve the identification accuracy of the high voltage circuit breakers’ (HVCBs mechanical fault types without training samples, a novel mechanical fault diagnosis method of HVCBs using a hybrid classifier constructed with Support Vector Data Description (SVDD and fuzzy c-means (FCM clustering method based on Local Mean Decomposition (LMD and time segmentation energy entropy (TSEE is proposed. Firstly, LMD is used to decompose nonlinear and non-stationary vibration signals of HVCBs into a series of product functions (PFs. Secondly, TSEE is chosen as feature vectors with the superiority of energy entropy and characteristics of time-delay faults of HVCBs. Then, SVDD trained with normal samples is applied to judge mechanical faults of HVCBs. If the mechanical fault is confirmed, the new fault sample and all known fault samples are clustered by FCM with the cluster number of known fault types. Finally, another SVDD trained by the specific fault samples is used to judge whether the fault sample belongs to an unknown type or not. The results of experiments carried on a real SF6 HVCB validate that the proposed fault-detection method is effective for the known faults with training samples and unknown faults without training samples.

  18. A comparison of two non-thrust mobilization techniques applied to the C7 segment in patients with restricted and painful cervical rotation.

    Science.gov (United States)

    Creighton, Doug; Gruca, Mark; Marsh, Douglas; Murphy, Nancy

    2014-11-01

    Cervical mobilization and manipulation have been shown to improve cervical range of motion and pain. Rotatory thrust manipulation applied to the lower cervical segments is associated with controversy and the potential for eliciting adverse reactions (AR). The purpose of this clinical trial was to describe two translatory non-thrust mobilization techniques and evaluate their effect on cervical pain, motion restriction, and whether any adverse effects were reported when applied to the C7 segment. This trial included 30 participants with painful and restricted cervical rotation. Participants were randomly assigned to receive one of the two mobilization techniques. Active cervical rotation and pain intensity measurements were recorded pre- and post-intervention. Within group comparisons were determined using the Wilcoxon signed-rank test and between group comparisons were analyzed using the Mann-Whitney U test. Significance was set at P = 0.05. Thirty participants were evaluated immediately after one of the two mobilization techniques was applied. There was a statistically significant difference (improvement) for active cervical rotation after application of the C7 facet distraction technique for both right (P = 0.022) and left (P = 0.022) rotation. Statistically significant improvement was also found for the C7 facet gliding technique for both right (P = 0.022) and left rotation (P = 0.020). Pain reduction was statistically significant for both right and left rotation after application of both techniques. Both mobilization techniques produced similar positive effects and one was not statistically superior to the other. A single application of both C7 mobilization techniques improved active cervical rotation, reduced perceived pain, and did not produce any AR in 30 patients with neck pain and movement limitation. These two non-thrust techniques may offer clinicians an additional safe and effective manual intervention for patients with limited and

  19. Improved Offline Connected Script Recognition Based on Hybrid Strategy

    Directory of Open Access Journals (Sweden)

    Tanzila Saba

    2010-06-01

    Full Text Available In domain of analytic cursive word recognition, there are two main approaches: explicit segmentation based and implicit segmentation based. However, both approaches have their own shortcomings. To overcome individual weaknesses, this paper presents a hybrid strategy for recognition of strings of characters (words or numerals. In a two stage dynamic programming based, lexicon driven approach, first an explicit segmentation is applied to segment either cursive andwritten words or numeric strings. However, at this stage, segmentation points are not finalized. In the second verification stage, statistical features are extracted from each segmented area to recognize characters using a trained neural network. To enhance segmentation and recognition accuracy, lexicon is consulted using existing dynamic programming matching techniques. Accordingly, segmentation points are altered to decide true character boundaries byusing lexicon feedback. A rigorous experimental protocol shows high performance of the proposed method for cursive handwritten words and numeral strings.

  20. PET/MRI: a novel hybrid imaging technique. Major clinical indications and preliminary experience in Brazil.

    Science.gov (United States)

    Vitor, Taise; Martins, Karine Minaif; Ionescu, Tudor Mihai; Cunha, Marcelo Livorsi da; Baroni, Ronaldo Hueb; Garcia, Marcio Ricardo Taveira; Wagner, Jairo; Campos, Guilherme de Carvalho; Nogueira, Solange Amorim; Guerra, Elaine Gonçalves; Amaro, Edson

    2017-01-01

    In recent years, medical imaging with hybrid techniques has widely accepted and employed in clinical routine. PET/MRI offers significant advantages, including excellent contrast and resolution and reduced ionizing radiation, as compared to well-established PET/CT. Therefore, PET/MRI is a promising modality for oncologic imaging of some regions, such as brain, head and neck, liver and pelvis. This article set out to analyze clinical conditions that could benefit from PET/MRI imaging based on our caseload. The potential of PET/MRI to become the imaging modality of choice for assessment of neurologic and oncologic conditions associated with soft tissues is highlighted. Clinical aspects of PET/MRI and its application to clinical cases are illustrated with examples extracted from the authors' preliminary experience. RESUMO Nos últimos anos, imagens médicas com tecnologias híbridas tornaram-se amplamente aceitas e utilizadas na prática clínica. O PET/RM possui vantagens importantes, incluindo excelentes contrastes e resolução, e menor radiação ionizante, em comparação ao PET/TC. Por isto, é uma modalidade promissora para exames de imagem de pacientes oncológicos, para avaliar o cérebro, cabeça e pescoço, o fígado e a pelve. O objetivo deste artigo foi analisar as situações clínicas que se beneficiariam de exames de PET/RM a partir de uma casuística. Destacamos o potencial desta técnica se tornar o método de imagem de escolha para doenças neurológicas e oncológicas que envolvam partes moles. Os aspectos clínicos de PET/RM e sua aplicação aos casos clínicos são ilustrados com exemplos da experiência inicial dos autores.

  1. Novel fabrication technique of hybrid structure lens array for 3D images

    Science.gov (United States)

    Lee, Junsik; Kim, Junoh; Kim, Cheoljoong; Shin, Dooseub; Koo, Gyohyun; Won, Yong Hyub

    2016-03-01

    Tunable liquid lens arrays can produce three dimensional images by using electrowetting principle that alters surface tensions by applying voltage. This method has advantages of fast response time and low power consumption. However, it is challenging to fabricate a high fill factor liquid lens array and operate three dimensional images which demand high diopter. This study describes a hybrid structure lens array which has not only a liquid lens array but a solid lens array. A concave-shape lens array is unavoidable when using only the liquid lens array and some voltages are needed to make the lens flat. By placing the solid lens array on the liquid lens array, initial diopter can be positive. To fabricate the hybrid structure lens array, a conventional lithographic process in semiconductor manufacturing is needed. A negative photoresist SU-8 was used as chamber master molds. PDMS and UV adhesive replica molding are done sequentially. Two immiscible liquids, DI water and dodecane, are injected in the fabricated chamber, followed by sealing. The fabricated structure has a 20 by 20 pattern of cylindrical shaped circle array and the aperture size of each lens is 1mm. The thickness of the overall hybrid structure is about 2.8mm. Hybrid structure lens array has many advantages. Solid lens array has almost 100% fill factor and allow high efficiency. Diopter can be increased by more than 200 and negative diopter can be shifted to the positive region. This experiment showed several properties of the hybrid structure and demonstrated its superiority.

  2. HybridSPE: A novel technique to reduce phospholipid-based matrix effect in LC-ESI-MS Bioanalysis.

    Science.gov (United States)

    Ahmad, Shafeeque; Kalra, Harsh; Gupta, Amit; Raut, Bharat; Hussain, Arshad; Rahman, Md Akhlaquer

    2012-10-01

    When complex biological materials are analyzed without an adequate sample preparation technique, MS signal and response undergo significant alteration and result in poor quantification and assay. This problem generally takes place due to the presence of several endogenous materials component in samples. One of the major causes of ion suppression in bioanalysis is the presence of phospholipids during LC-MS analysis. The phospholipid-based matrix effect was investigated with a commercially available electro spray ionization (ESI) source coupled with a triple quadrupole mass spectrometer. HybridSPE dramatically reduced the levels of residual phospholipids in biological samples, leading to significant reduction in matrix effects. This new procedure that combines the simplicity of precipitation with the selectivity of SPE allows obtaining much cleaner extracts than with conventional procedures. HybridSPE-precipitation procedure provides significant improvement in bioanalysis and a practical and fast way to ensure the avoidance of phospholipids-based matrix effects. The present review outlines the HybridSPE technique to minimize phospholipids-based matrix effects on LC-ESI-MS bioanalysis.

  3. HybridSPE: A novel technique to reduce phospholipid-based matrix effect in LC-ESI-MS Bioanalysis

    Directory of Open Access Journals (Sweden)

    Shafeeque Ahmad

    2012-01-01

    Full Text Available When complex biological materials are analyzed without an adequate sample preparation technique, MS signal and response undergo significant alteration and result in poor quantification and assay. This problem generally takes place due to the presence of several endogenous materials component in samples. One of the major causes of ion suppression in bioanalysis is the presence of phospholipids during LC-MS analysis. The phospholipid-based matrix effect was investigated with a commercially available electro spray ionization (ESI source coupled with a triple quadrupole mass spectrometer. HybridSPE dramatically reduced the levels of residual phospholipids in biological samples, leading to significant reduction in matrix effects. This new procedure that combines the simplicity of precipitation with the selectivity of SPE allows obtaining much cleaner extracts than with conventional procedures. HybridSPE-precipitation procedure provides significant improvement in bioanalysis and a practical and fast way to ensure the avoidance of phospholipids-based matrix effects. The present review outlines the HybridSPE technique to minimize phospholipids-based matrix effects on LC-ESI-MS bioanalysis.

  4. Hybrid approach to AAA: bilateral "banana" technique to preserve hypogastric artery in complex anatomy aorto-biiliac aneurysm.

    Science.gov (United States)

    Mosquera Arochena, N; Molina Herrero, F; Carbalho Fernandez, C; Rodriguez Feijoo, G; Fernandez Lebrato, R; Barrios Castro, A; Garcia Fernandez, I

    2011-01-01

    The surgical approach for hypogastric preservation in aorto-iliac aneurysm (AAA) open repair (OR) has been described and performed with different techniques but all of them represent a higher mortality and potencial complications to the procedure; this is even more critical in bilateral disease. Since the introduction of the first endograft, a continuous development has occurred, such as the stent graft with specific branch designed for preserving antegrade flow in the hypogastric artery. On highly angulated and tortuous iliac anatomies, the use of Sandwich-Graft technique, as described by Armando Lobato, represents a valid alternative to iliac branch. The hybrid approach could be a good treatment option in young patients with AAA affecting hypogastric arteries. We present the technical description and a case report of bilateral "banana" technique perfor- med with flexible covered stent (Viabahn(®) WL Gore) to preserve both hypogastric arteries combined with open repair in a 52 years old patient. Technical report and Results: A bilateral retrograde endograft was implanted from both external ilac arteries to hypo- gastric artery excluding bilateral common iliac aneurysms followed by an open repair to the AAA (aneurismectomy + aorto bifemoral by-pass) with good inmediate and short-midterm follow up (12 months) This hybrid technique could be a good approach to hypogastric preservation in low risk and young patients reducing potencial complications of hypogastric artery oclusion.

  5. N-doped ZnO films grown from hybrid target by the pulsed laser deposition technique

    Science.gov (United States)

    Martín-Tovar, E. A.; Chan y Díaz, E.; Acosta, M.; Castro-Rodríguez, R.; Iribarren, A.

    2016-10-01

    ZnO thin films were grown by the pulsed laser deposition technique on glass substrate using a hybrid target composed of ZnO powder embedded into a poly(ethyl cyanoacrylate) matrix. The resulting thin film presented ZnO wurtzite structure with very low stress and diffractogram very similar to that of the powder pattern. From comparing with ZnO thin films grown from traditional sintered target, it is suggested that the use of this hybrid target with a soft matrix led to ejection of ZnO clusters that conveniently disposed and adhered to substrate and previous deposited layers. Chemical measurements showed the presence of Zn-N bonds, besides Zn-O ones. Optical absorption profile confirmed the presence of low-polymerized zinc oxynitride molecular subunits, besides ZnO.

  6. Dielectric property determination of hybrid Al2O3-filled MWCNT buckypaper by the rectangular cavity perturbation technique

    Science.gov (United States)

    Miao, Hsin-Yuan; Liu, Jih-Hsin; Saravanan, L.; Tsao, Che-Wei; Pan, Jui-Wen

    2015-04-01

    This study investigated the complex dielectric permittivity of freestanding multiwalled carbon nanotube buckypaper (MWCNT-BP) and a synthesized hybrid alumina-filled buckypaper (Al2O3-BP) composite with different alumina loadings (5-30 wt%). The non-destructive microwave transmission technique for complex permittivity determination involving cavity perturbation was employed to characterize a set of Al2O3-BP sheets. This was done by filling a rectangular cavity resonator with a standard dielectric Teflon sample and then performing permittivity measurements for the buckypaper (BP) samples in the X-band frequency range (7-12 GHz). Field-emission scanning electron microscopy (FESEM) was used to analyze the morphology of the MWCNT-BP and the alumina-loaded BP composites. DC electrical resistivity measurements clearly demonstrated conductor-insulator transition. The effect of alumina loadings on the dielectric properties of the synthesized hybrid Al2O3-BP sheet is discussed.

  7. Image Segmentation Techniques Applied in Coal Production%图像分割技术在煤矿生产中的应用

    Institute of Scientific and Technical Information of China (English)

    李忠杰; 胡文涛; 胡宁

    2012-01-01

    As the special application environment of coal fields, the image segmentation technique is commonly used to directly cut the surveillance image of the underground coal mines video, but it often does not get the desired effect. This paper provides comparisons and analysis of several commonly used image segmentation algorithms in the applications for coal mine environmental requirements.%由于煤矿领域特殊的应用环境,常用的图像分割技术直接对煤矿井下视频监控图像的分割往往得不到理想的效果.本文针对煤矿应用领域的环境要求,对常用的几种图像分割算法进行深入比较分析.

  8. Evaluation of an improved technique for lumen path definition and lumen segmentation of atherosclerotic vessels in CT angiography.

    Science.gov (United States)

    van Velsen, Evert F S; Niessen, Wiro J; de Weert, Thomas T; de Monyé, Cécile; van der Lugt, Aad; Meijering, Erik; Stokking, Rik

    2007-07-01

    Vessel image analysis is crucial when considering therapeutical options for (cardio-) vascular diseases. Our method, VAMPIRE (Vascular Analysis using Multiscale Paths Inferred from Ridges and Edges), involves two parts: a user defines a start- and endpoint upon which a lumen path is automatically defined, and which is used for initialization; the automatic segmentation of the vessel lumen on computed tomographic angiography (CTA) images. Both parts are based on the detection of vessel-like structures by analyzing intensity, edge, and ridge information. A multi-observer evaluation study was performed to compare VAMPIRE with a conventional method on the CTA data of 15 patients with carotid artery stenosis. In addition to the start- and endpoint, the two radiologists required on average 2.5 (SD: 1.9) additional points to define a lumen path when using the conventional method, and 0.1 (SD: 0.3) when using VAMPIRE. The segmentation results were quantitatively evaluated using Similarity Indices, which were slightly lower between VAMPIRE and the two radiologists (respectively 0.90 and 0.88) compared with the Similarity Index between the radiologists (0.92). The evaluation shows that the improved definition of a lumen path requires minimal user interaction, and that using this path as initialization leads to good automatic lumen segmentation results.

  9. Simultaneous Kissing Stenting: A Valuable Technique for Reconstructing the Stenotic Initial Segment of the Right Subclavian Artery.

    Science.gov (United States)

    Zhang, Ping; Chen, Daiqi; Tian, Daishi; Zhang, Qiang; Wang, Minghuan; Li, Qian; Luo, Xiang

    2017-03-01

    Atherosclerotic stenosis or occlusion often involves the subclavian artery. For lesions that are close to the orifice of the right subclavian artery, stenting of the right subclavian artery itself blocks the pathway from the innominate artery to the right carotid artery and causes problems in patients with multiple angiostenosis, especially involving the right carotid system. In this study, we report 2 cases using simultaneous kissing stenting (SKS) of the right subclavian artery and the right carotid artery to relieve right subclavian stenosis and maintain right carotid system patency. Standard stenting methods were used to perform SKS. Two self-expanding stents were implanted simultaneously into the initial segment of the right subclavian artery and the right carotid artery, forming a "Y" shape, with the overlap of the proximal segments in the innominate artery ≥5 mm. After SKS, the stenosed right subclavian artery was dilated, and the patency of the right carotid system was maintained. The symptoms of patients were relieved and the stents were intact at several months of follow-up. In conclusion, SKS of the right subclavian artery and the right carotid artery might be a safe and effective procedure when the stenotic or occlusive lesion in the initial segment of the right subclavian artery is close to the orifice, and lesions (or potential ones) exist in the right carotid system.

  10. Hybrid models for hydrological forecasting: integration of data-driven and conceptual modelling techniques

    NARCIS (Netherlands)

    Corzo Perez, G.A.

    2009-01-01

    This book presents the investigation of different architectures of integrating hydrological knowledge and models with data-driven models for the purpose of hydrological flow forecasting. The models resulting from such integration are referred to as hybrid models. The book addresses the following top

  11. A hybrid method for flood simulation in small catchments combining hydrodynamic and hydrological techniques

    Science.gov (United States)

    Bellos, Vasilis; Tsakiris, George

    2016-09-01

    The study presents a new hybrid method for the simulation of flood events in small catchments. It combines a physically-based two-dimensional hydrodynamic model and the hydrological unit hydrograph theory. Unit hydrographs are derived using the FLOW-R2D model which is based on the full form of two-dimensional Shallow Water Equations, solved by a modified McCormack numerical scheme. The method is tested at a small catchment in a suburb of Athens-Greece for a storm event which occurred in February 2013. The catchment is divided into three friction zones and unit hydrographs of 15 and 30 min are produced. The infiltration process is simulated by the empirical Kostiakov equation and the Green-Ampt model. The results from the implementation of the proposed hybrid method are compared with recorded data at the hydrometric station at the outlet of the catchment and the results derived from the fully hydrodynamic model FLOW-R2D. It is concluded that for the case studied, the proposed hybrid method produces results close to those of the fully hydrodynamic simulation at substantially shorter computational time. This finding, if further verified in a variety of case studies, can be useful in devising effective hybrid tools for the two-dimensional flood simulations, which are lead to accurate and considerably faster results than those achieved by the fully hydrodynamic simulations.

  12. Hybrid models for hydrological forecasting: Integration of data-driven and conceptual modelling techniques

    NARCIS (Netherlands)

    Corzo Perez, G.A.

    2009-01-01

    This book presents the investigation of different architectures of integrating hydrological knowledge and models with data-driven models for the purpose of hydrological flow forecasting. The models resulting from such integration are referred to as hybrid models. The book addresses the following top

  13. Role of hybrid forecasting techniques for transportation planning of broiler meat under uncertain demand in thailand

    Directory of Open Access Journals (Sweden)

    Thoranin Sujjaviriyasup

    2014-12-01

    Full Text Available One of numerous problems experiencing in supply chain management is the demand. Most demands are appeared in terms of uncertainty. The broiler meat industry is inevitably encountering the same problem. In this research, hybrid forecasting model of ARIMA and Support Vector Machine (SVMs are developed to forecast broiler meat export. In addition, ARIMA, SVMs, and Moving Average (MA are chosen for comparing the forecasting efficiency. All the forecasting models are tested and validated using the data of Brazil’s export, Canada’s export, and Thailand’s export. The hybrid model provides accuracy of the forecasted values that are 98.71%, 97.50%, and 93.01%, respectively. In addition, the hybrid model presents the least error of all MAE, RMSE, and MAPE comparing with other forecasting models. As forecasted data are applied to transportation planning, the mean absolute percentage error (MAPE of optimal value of forecasted value and actual value is 14.53%. The hybrid forecasting model shows an ability to reduce risk of total cost of transportation when broiler meat export is forecasted by using MA(2, MA(3, ARIMA, and SVM are 50.59%, 60.18%, 68.01%, and 46.55%, respectively. The results indicate that the developed forecasting model is recommended to broiler meat industries’ supply chain decision.

  14. Hybrid and Model-Based Iterative Reconstruction Techniques for Pediatric CT

    NARCIS (Netherlands)

    den Harder, Annemarie M.; Willemink, Martin J.; Budde, Ricardo P. J.; Schilham, Arnold M. R.; Leiner, Tim; de Jong, Pim A.

    2015-01-01

    OBJECTIVE. Radiation exposure from CT examinations should be reduced to a minimum in children. Iterative reconstruction (IR) is a method to reduce image noise that can be used to improve CT image quality, thereby allowing radiation dose reduction. This article reviews the use of hybrid and model-bas

  15. Hybrid models for hydrological forecasting: integration of data-driven and conceptual modelling techniques

    NARCIS (Netherlands)

    Corzo Perez, G.A.

    2009-01-01

    This book presents the investigation of different architectures of integrating hydrological knowledge and models with data-driven models for the purpose of hydrological flow forecasting. The models resulting from such integration are referred to as hybrid models. The book addresses the following

  16. Hybrid models for hydrological forecasting: Integration of data-driven and conceptual modelling techniques

    NARCIS (Netherlands)

    Corzo Perez, G.A.

    2009-01-01

    This book presents the investigation of different architectures of integrating hydrological knowledge and models with data-driven models for the purpose of hydrological flow forecasting. The models resulting from such integration are referred to as hybrid models. The book addresses the following

  17. Biological evaluation of zirconia/PEG hybrid materials synthesized via sol-gel technique.

    Science.gov (United States)

    Catauro, M; Papale, F; Bollino, F; Gallicchio, M; Pacifico, S

    2014-07-01

    The objective of the following study has been the synthesis via sol-gel and the characterization of novel organic-inorganic hybrid materials to be used in biomedical field. The prepared materials consist of an inorganic zirconia matrix containing as organic component the polyethylene glycol (PEG), a water-soluble polymer used in medical and pharmaceutical fields. Various hybrids have been synthesized changing the molar ratio between the organic and inorganic parts. Fourier transform spectroscopy suggests that the structure of the interpenetrating network is realized by hydrogen bonds between the Zr-OH group in the sol-gel intermediate species and both the terminal alcoholic group and ethereal oxygen atoms in the repeating units of polymer The amorphous nature of the gels has been ascertained by X-ray diffraction analysis. The morphology observation has been carried out by using the Scanning Electron Microscope and has confirmed that the obtained materials are nanostructurated hybrids. The bioactivity of the synthesized system has been shown by the formation of a hydroxyapatite layer on the surface of samples soaked in a fluid simulating the human blood plasma. The potential biocompatibility of hybrids has been assessed as performing indirect MTT cytotoxicity assay towards 3T3 cell line at 24, 48, and 72 h exposure times. Copyright © 2014. Published by Elsevier B.V.

  18. Rapid high-throughput genotyping of HBV DNA using a modified hybridization-extension technique.

    Science.gov (United States)

    Bao, Han; Zhao, Wenliang; Ruan, Banjun; Wang, Qing; Zhao, Jinrong; Lei, Xiaoying; Wang, Weihua; Liu, Yonglan; Sun, Jianbing; Xiang, An; Guo, Yanhai; Yan, Zhen

    2013-11-07

    China has the highest incidence of hepatitis B virus (HBV) infection worldwide. HBV genotypes have variable impacts on disease pathogenesis and drug tolerance. We have developed a technically simple and accurate method for HBV genotyping that will be applicable to pre-treatment diagnosis and individualized treatment. Multiple sequence alignments of HBV genomes from GenBank were used to design primers and probes for genotyping of HBV A through H. The hybridization was carried out on nitrocellulose (NC) membranes with probes fixed in an array format, which was followed by hybrid amplification by an extension step with DNA polymerase to reinforce the double-stranded DNA hybrids on the NC membrane and subsequent visualization using an avidin-biotin system. Genotyping results were confirmed by DNA sequencing and bioinformatics analysis using the National Center for Biotechnology Information genotyping database, and compared with results from the line probe assay. The data show that multiple sequence alignment defined a 630 bp region in the HBV PreS and S regions that was suitable for genotyping. All genotyping significant single nucleotides in the region were defined. Two-hundred-and-ninety-one HBV-positive serum samples from Northwest Chinese patients were genotyped, and the genotyping rate from the new modified hybridization-extension method was 100% compared with direct sequencing. Compared with line probe assay, the newly developed method is superior, featuring reduced reaction time, lower risk of contamination, and increased accuracy for detecting single nucleotide mutation. In conclusion, a novel hybridization-extension method for HBV genotyping was established, which represents a new tool for accurate and rapid SNP detection that will benefit clinical testing.

  19. Adjustable muscle plication: a new surgical technique for strabismic patients with high risk for anterior segment ischemia

    Institute of Scientific and Technical Information of China (English)

    Carlos; Laria; David; P.Pi?ero

    2015-01-01

    <正>INTRODUCTION Anterior ciliary arteries provide 70%of the vascular supply of the anterior segment.A significant interruption of the vascular flow of these arteries increases the risk for anterior ischemia.Although the frequency of this special condition is low after strabismus surgery(1:13 000)[1],its effects may involve substantial visual problems[2].We report the successful outcome of a new surgical approach for strabismus management in a case of high risk for anterior ischemia.Specifically,we show the correction of the horizontal ocular deviation by means of an adjustable muscle

  20. Energy Spectrum of Ultra-High Energy Cosmic Rays Observed with the Telescope Array Using a Hybrid Technique

    CERN Document Server

    Abu-Zayyad, T; Allen, M; Anderson, R; Azuma, R; Barcikowski, E; Belz, J W; Bergman, D R; Blake, S A; Cady, R; Cheon, B G; Chiba, J; Chikawa, M; Cho, E J; Cho, W R; Fujii, H; Fujii, T; Fukuda, T; Fukushima, M; Hanlon, W; Hayashi, K; Hayashi, Y; Hayashida, N; Hibino, K; Hiyama, K; Honda, K; Iguchi, T; Ikeda, D; Ikuta, K; Inoue, N; Ishii, T; Ishimori, R; Ito, H; Ivanov, D; Iwamoto, S; Jui, C C H; Kadota, K; Kakimoto, F; Kalashev, O; Kanbe, T; Kasahara, K; Kawai, H; Kawakami, S; Kawana, S; Kido, E; Kim, H B; Kim, H K; Kim, J H; Kitamoto, K; Kitamura, S; Kitamura, Y; Kobayashi, K; Kobayashi, Y; Kondo, Y; Kuramoto, K; Kuzmin, V; Kwon, Y J; Lan, J; Lim, S I; Lundquist, J P; Machida, S; Martens, K; Matsuda, T; Matsuura, T; Matsuyama, T; Matthews, J N; Minamino, M; Miyata, K; Murano, Y; Myers, I; Nagasawa, K; Nagataki, S; Nakamura, T; Nam, S W; Nonaka, T; Ogio, S; Ohnishi, M; Ohoka, H; Oki, K; Oku, D; Okuda, T; Ono, M; Oshima, A; Ozawa, S; Park, I H; Pshirkov, M S; Rodriguez, D C; Roh, S Y; Rubtsov, G; Ryu, D; Sagawa, H; Sakurai, N; Sampson, A L; Scott, L M; Shah, P D; Shibata, F; Shibata, T; Shimodaira, H; Shin, B K; Shin, J I; Shirahama, T; Smith, J D; Sokolsky, P; Springer, R W; Stokes, B T; Stratton, S R; Stroman, T; Suzuki, S; Takahashi, Y; Takeda, M; Taketa, A; Takita, M; Tameda, Y; Tanaka, H; Tanaka, K; Tanaka, M; Thomas, S B; Thomson, G B; Tinyakov, P; Tkachev, I; Tokuno, H; Tomida, T; Troitsky, S; Tsunesada, Y; Tsutsumi, K; Tsuyuguchi, Y; Uchihori, Y; Udo, S; Ukai, H; Urban, F; Vasiloff, G; Wada, Y; Wong, T; Yamakawa, Y; Yamane, R; Yamaoka, H; Yamazaki, K; Yang, J; Yoneda, Y; Yoshida, S; Yoshii, H; Zhou, X; Zollinger, R; Zundel, Z

    2013-01-01

    We measure the spectrum of cosmic rays with energies greater than $10^{18.2}$ eV with the Fluorescence Detectors (FDs) and the Surface Detectors (SDs) of the Telescope Array Experiment using the data taken in our first 2.3-year observation from May 27 2008 to September 7 2010. A hybrid air shower reconstruction technique is employed to improve accuracies in determination of arrival directions and primary energies of cosmic rays using both FD and SD data. The energy spectrum presented here is in agreement with our previously published spectra and the HiRes results.

  1. ADAPTING HYBRID MACHINE TRANSLATION TECHNIQUES FOR CROSS-LANGUAGE TEXT RETRIEVAL SYSTEM

    Directory of Open Access Journals (Sweden)

    P. ISWARYA

    2017-03-01

    Full Text Available This research work aims in developing Tamil to English Cross - language text retrieval system using hybrid machine translation approach. The hybrid machine translation system is a combination of rule based and statistical based approaches. In an existing word by word translation system there are lot of issues and some of them are ambiguity, Out-of-Vocabulary words, word inflections, and improper sentence structure. To handle these issues, proposed architecture is designed in such a way that, it contains Improved Part-of-Speech tagger, machine learning based morphological analyser, collocation based word sense disambiguation procedure, semantic dictionary, and tense markers with gerund ending rules, and two pass transliteration algorithm. From the experimental results it is clear that the proposed Tamil Query based translation system achieves significantly better translation quality over existing system, and reaches 95.88% of monolingual performance.

  2. Application of hybrid microwave thermal extraction techniques for mulberry root bark

    OpenAIRE

    Wang Cheng-Chi; Yau Her-Terng

    2013-01-01

    The main focus of this paper is the extraction of compounds from the mulberry root bark using a hybrid microwave thermal process. The shearing mechanism and an integrated circulation system, which increases the rate of contact between the solvent and extractive, are studied. The results are analyzed by the Taguchi method and verified by high performance liquid chromatography. Furthermore, the optimal operating parameters of the extraction of mulberry root b...

  3. Development and Application of Nucleic Acid Hybridization Techniques to Arbovirus Surveillance and Diagnosis.

    Science.gov (United States)

    1986-11-04

    The pVV9 and pWV7 probes were more specific for dengue-2 RNA, but-o ::e cross reaction with other dengue serotypes was noted. ,PdUc1biLity Codes S...contained dengue specific inserts that strongly hybridized to dengue-2 RMA and to the RNA of other dengue serotypes to varying degrees (Figure 6). The pVVl

  4. FPGA Techniques Based New Hybrid Modulation Strategies for Voltage Source Inverters

    OpenAIRE

    Sudha, L. U.; J. Baskaran; Elankurisil, S. A.

    2015-01-01

    This paper corroborates three different hybrid modulation strategies suitable for single-phase voltage source inverter. The proposed method is formulated using fundamental switching and carrier based pulse width modulation methods. The main tale of this proposed method is to optimize a specific performance criterion, such as minimization of the total harmonic distortion (THD), lower order harmonics, switching losses, and heat losses. The proposed method is articulated using fundamental switch...

  5. Application of DNA hybridization techniques in the assessment of diarrheal disease among refugess in Thailand. [Shigella; Escherichia coli; Campylobacter; Cryptosporidium

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, D.N.; Echeverria, P.; Pitarangsi, C.; Seriwatana, J.; Sethabutr, O.; Bodhidatta, L.; Brown, C.; Herrmann, J.E.; Blacklow, N.R.

    1988-01-01

    The epidemiology and etiology of acute diarrheal disease were determined in a Hmong refugee camp on the Thai-Laotian border from April 11 to May 14, 1985. DNA hybridization techniques were used to detect Shigella species, enteroinvasive Escherichia coli, and enterotoxigenic E. coli. A monoclonal enzyme-linked immunosorbent assay was used to detect rotavirus, and standard microbiology was used to detect other enteropathogens. The age-specific diarrheal disease rates were 47 episodes per month per 1000 children less than five years old and 113 episodes per month per 1000 children less than one year old. Rotavirus, enterotoxigenic E. coli, Campylobacter, and Cryptosporidium were the predominant pathogens in children less than two years old. The DNA probe hybridized with 94% of 31 specimens identified as enterotoxigenic E. coli by the standard assays and with none of the specimens in which the standard assays were negative. The probe for Shigella and enteroinvasive E. coli hybridized in eight of 10 stools that contained Shigella and four of 314 stools from which Shigella and enteroinvasive E. coli were not isolated. The use of DNA probes allows specimens to be collected in remote areas with a minimum amount of equipment and technical expertise so that they can be easily transported to a central laboratory for further processing.

  6. Screening of FOXP3-interacted proteins by yeast two-hybrid technique

    Institute of Scientific and Technical Information of China (English)

    Zhou Lina; Wu Jun; Luo Gaoxing; He Weifeng; Chen Xiwei; Bo Ganping; Yuan Shunzong; Zhang Xiaorong; Hu Xiaohong

    2008-01-01

    Objective: To screen the proteins interacting with the Treg specification factor forkhead box protein P3 (FOXP3) by yeast two-hybrid system. Methods: Human FOXP3 gene was amplified by nest RT-PCR from peripheral blood mononuclear cells (PBMC) and inserted into plasmid pGBKT7 to construct the bait vector, then the self-activation and toxicity of the bait vector in host yeast strain AH109 were observed. Thereafter, a human liver cDNA library was screened by the bait vector. The positive clones were selected out by nutrient-deficient culture and back-hybridizing. The sequences from the candidate positive clones were blasted and analyzed by bioinformatics methods. Results: The constructed bait vector encoding FOXP3 was found no self-activation and toxicity in yeast AH109. Three proteins which interacted with FOXP3, including tumor protein D52, splicing factor 3b subunit 1 and hypothetical protein, were identified. Conclusion: Three new candidate proteins interacting with FOXP3 are selected out by this yeast two-hybrid system and library, which may facilitate the further study of FOXP3 in Treg.

  7. 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...

  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. Collision avoidance for a mobile robot based on radial basis function hybrid force control technique

    Institute of Scientific and Technical Information of China (English)

    Wen Shu-Huan

    2009-01-01

    Collision avoidance is always difficult in the planning path for a mobile robot. In this paper, the virtual force field between a mobile robot and an obstacle is formed and regulated to maintain a desired distance by hybrid force control algorithm. Since uncertainties from robot dynamics and obstacle degrade the performance of a collision avoidance task, intelligent control is used to compensate for the uncertainties. A radial basis function (RBF) neural network is used to regulate the force field of an accurate distance between a robot and an obstacle in this paper and then simulation studies are conducted to confirm that the proposed algorithm is effective.

  10. GENERAL: Collision avoidance for a mobile robot based on radial basis function hybrid force control technique

    Science.gov (United States)

    Wen, Shu-Huan

    2009-10-01

    Collision avoidance is always difficult in the planning path for a mobile robot. In this paper, the virtual force field between a mobile robot and an obstacle is formed and regulated to maintain a desired distance by hybrid force control algorithm. Since uncertainties from robot dynamics and obstacle degrade the performance of a collision avoidance task, intelligent control is used to compensate for the uncertainties. A radial basis function (RBF) neural network is used to regulate the force field of an accurate distance between a robot and an obstacle in this paper and then simulation studies are conducted to confirm that the proposed algorithm is effective.

  11. An alternative hybrid evolutionary technique focused on allocating machines and sequencing operations

    Directory of Open Access Journals (Sweden)

    Mariano Frutos

    2016-09-01

    Full Text Available We present here a hybrid algorithm for the Flexible Job-Shop Scheduling Problem (FJSSP. This problem involves the optimal use of resources in a flexible production environment in which each operation can be carried out by more than a single machine. Our algorithm allocates, in a first step, the machines to operations and in a second stage it sequences them by integrating a Multi-Objective Evolutionary Algorithm (MOEA and a path-dependent search algorithm (Multi-Objective Simulated Annealing, which is enacted at the genetic phase of the procedure. The joint interaction of those two components yields a very efficient procedure for solving the FJSSP. An important step in the development of the algorithm was the selection of the right MOEA. Candidates were tested on problems of low, medium and high complexity. Further analyses showed the relevance of the search algorithm in the hybrid structure. Finally, comparisons with other algorithms in the literature indicate that the performance of our alternative is good.

  12. STUDY OF MECHANICAL PROPERTIES OF BANANA-COIR HYBRID COMPOSITE USING EXPERIMENTAL AND FEM TECHNIQUES

    Directory of Open Access Journals (Sweden)

    T. Hariprasad

    2013-06-01

    Full Text Available The use of natural fibers as reinforcement in polymers has gained importance in recent years due to their eco-friendly nature. Thus, an investigation has been undertaken on banana-coir, which is a natural fiber abundantly available in India. Natural fibers are not only strong and lightweight, but also relatively very cheap. Composite plates were prepared with resin 392 g, coir 54 g, and banana 69 g. The purpose of this work is to establish the tensile, flexural, and impact properties of banana-coir reinforced composite materials with a thermo set for treated and untreated fibers. The resin used was epoxy (EP306. The tensile and impact tests showed that treated banana-coir epoxy hybrid composites have higher tensile strength and impact strength than untreated composites. However, untreated fiber composites have greater flexural strength than the treated fiber composites. The finite element analysis (FEA software ANSYS has been employed successfully to evaluate the properties. The stresses at the interface of the banana-coir and matrix, induced by the different loading conditions, were applied to predict the tensile, impact, and flexural properties by using the FEA models. The model output was compared with the experimental results and found to be close. This analysis is useful for realizing the advantages of hybrid fiber reinforced composites in structural applications and for identifying where the stresses are critical and damage the interface under varying loading conditions.

  13. Improved performance of hybrid error control techniques for real-time digital communications over noisy channels

    Science.gov (United States)

    Yang, Charlie Qing

    1993-06-01

    Delay-related performance characteristics are investigated for asynchronous time division multiplexing links. Two methods based on an imbedded Markov chain model are developed and applied to the system with a noisy feedback channel yielding analytical expressions for the buffer occupancy and the block delay. A recursive expression for packet loss probability for systems with a finite transmitter buffer is obtained. The concept of delay limited error control coding is introduced for real-time communications. Performance improvement by truncation of a type-2 hybrid automatic repeat-request (ARQ) protocol with one retransmission is examined showing that the truncated protocol has a bounded delay and bounded queue length under typical conditions. The error performance of the truncated protocol is further analyzed for various mobile fading channels. Matched rate hybrid error control coding for both adaptive and non-adaptive cases is also studied. A new adaptive error control protocol using Reed-Solomon codes is proposed using novel feedback transmissions to achieve faster estimation of channel states. Numerical optimization is carried out by introducing overall and modified throughput as efficiency criteria. Based on channel bit error rate measurement, optimum overall throughput is obtained with minimum implementation complexity.

  14. Hybrid technique coil embolisation for intrahepatic arterioportal fistula in a cat: case report

    Directory of Open Access Journals (Sweden)

    Akiko Uemura

    2016-04-01

    Full Text Available Case summary A 13-month-old, female, mixed breed, 4.0 kg cat was referred with a 6 month history of decreased appetite, loss of vigour and intermittent vomiting. Physical examination revealed no cyanosis or wasting, and no audible heart murmur was auscultated. Blood profile revealed mild anaemia and mildly elevated postprandial serum ammonia (109 µg/dl. Abdominal ultrasonography revealed dilation of an intrahepatic portal vein branch and an intrahepatic aneurysm, with splenomegaly and ascites. Hepatic arteriovenous fistula/hepatic artery–portal vein fistula with multiple acquired portosystemic shunts was strongly suspected. Medical control was achieved using antibiotics, liver-protecting agents, a low-protein diet and blood transfusions. However, because medical treatment proved ineffective, coil embolisation was performed on day 11, using a hybrid approach via the mesenteric vein. Subsequent follow-up showed good appetite, with no signs of diarrhoea or ascites. Abdominal ultrasonography revealed that the mosaic pattern around the site of coil placement in the portal vein branch had improved and pulsatility had disappeared. Relevance and novel information Intrahepatic arterioportal fistula involves a circulatory shunt between the hepatic artery and the hepatic or portal vein within the liver, and may be congenital or acquired. Both forms have been reported in humans, but most cases in cats have been congenital. Few reports have described treatment methods or prognosis in cats. We report here that coil embolisation using a hybrid approach is a procedure offering easy, effective treatment by blocking hepatofugal blood flow.

  15. DRYING OF EMPTY FRUIT BUNCHES AS WASTED BIOMASS BY HYBRID SOLAR–THERMAL DRYING TECHNIQUE

    Directory of Open Access Journals (Sweden)

    H. H. Al-Kayiem

    2013-12-01

    Full Text Available Solar drying of EFB is highly feasible and economic, but the solar drying process is interrupted during cloudy or rainy days and also at night. In the present paper, a combined solar, as the main heat input, and biomass burner, as an auxiliary source of thermal energy, has been investigated experimentally to dry EFB. An experimental model consisting of a solar dryer integrated with a thermal backup unit was designed and fabricated. A series of experimental measurements were carried out in four different drying modes, namely, open sun, mixed direct and indirect solar, thermal backup, and hybrid. The results from the four modes used to dry 2.5 kg of EFB were summarized and compared. The results indicated that the solar drying mode required around 52 to 80 hours to dry the EFB, while the open sun drying mode required 100 hours. Usage of the thermal backup as heat source reduced the drying time to 48–56 hours. With the hybrid mode, the drying time was considerably reduced to 24–32 hours. The results demonstrate that the combined solar and thermal backup effectively enhanced the drying performance. The application of a solar dryer with a biomass burner is practical for massive production of solid fuels from EFB.

  16. Active control of broadband sound transmission through an airplane trim panel using hybrid feedforward and feedback techniques

    Science.gov (United States)

    Ho, Yun-Ren

    This thesis presents a method of actively controlling the sound transmission through two designs of aircraft trim panels using a hybrid feedforward and feedback control technique. The active trim panels are designed for a high stiffness to mass ratio to allow only rigid body modal vibration in the frequency range of interest, thus simplifying the control technique, which is developed to minimize the vibration of a panel and therefore minimize the sound transmission. The hybrid controller consists of an adaptive feedforward (filtered-X LMS algorithm) controller in conjunction with a linear quadratic Gaussian (LQG) feedback controller. The LQG feedback controller is designed to alter the dynamics of the estimated plant model of the filtered-x LMS algorithm, improving control performance for both steady state and transient disturbances. Numerical simulations indicate that the hybrid controller is a more effective method of reducing the vibrations of the panels (and therefore the sound transmission) when compared to using only a feedforward or feedback controller. Experiments were carried out by using two trim panel designs, the first exhibiting only an out-of-plane piston mode, and the second exhibiting three rigid body modes and the first bending mode in control frequency range. For the first trim panel, the implementation of the active control experiment showed that a 5 to 20 dB reduction in both the vibration level and sound pressure level could be achieved over 50 to 500 Hz under a plane acoustic wave excitation. For the second trim panel, the hybrid controller achieved a 5 to 20 dB vibration reduction over the 50 to 400 Hz frequency band under structure-borne excitation. For air-borne excitation, the control scheme produced a 5 to 15 dB vibration reduction over the 70 to 400 Hz bandwidth with a reference microphone attached on the center of the fuselage skin and facing the sound source. In the near field (50 cm from the panel), the sound pressure levels measured

  17. Remediation of uranium-contaminated soil using the Segmented Gate System and containerized vat leaching techniques: a cost effectiveness study

    Energy Technology Data Exchange (ETDEWEB)

    Cummings, M.; Booth, S.R.

    1996-09-01

    Because it is difficult to characterize heterogeneously contaminated soils in detail and to excavate such soils precisely using heavy equipment, it is common for large quantities of uncontaminated soil to be removed during excavation of contaminated sites. Until now, volume reduction of radioactively contaminated soil depended upon manual screening and analysis of samples, a costly and impractical approach, particularly with large volumes of heterogeneously contaminated soil. The baseline approach for the remediation of soils containing radioactive waste is excavation, pretreatment, containerization, and disposal at a federally permitted landfill. However, disposal of low-level radioactive waste is expensive and storage capacity is limited. ThermoNuclean`s Segmented Gate System (SGS) removes only the radioactively contaminated soil, in turn greatly reducing the volume of soils that requires disposal. After processing using the SGS, the fraction of contaminated soil is processed using the containerized vat leaching (CVL) system developed at LANL. Uranium is leached out of the soil in solution. The uranium is recovered with an ion exchange resin, leaving only a small volume of liquid low-level waste requiring disposal. The reclaimed soil can be returned to its original location after treatment with CVL.

  18. Hybrid Neural-Network: Genetic Algorithm Technique for Aircraft Engine Performance Diagnostics Developed and Demonstrated

    Science.gov (United States)

    Kobayashi, Takahisa; Simon, Donald L.

    2002-01-01

    As part of the NASA Aviation Safety Program, a unique model-based diagnostics method that employs neural networks and genetic algorithms for aircraft engine performance diagnostics has been developed and demonstrated at the NASA Glenn Research Center against a nonlinear gas turbine engine model. Neural networks are applied to estimate the internal health condition of the engine, and genetic algorithms are used for sensor fault detection, isolation, and quantification. This hybrid architecture combines the excellent nonlinear estimation capabilities of neural networks with the capability to rank the likelihood of various faults given a specific sensor suite signature. The method requires a significantly smaller data training set than a neural network approach alone does, and it performs the combined engine health monitoring objectives of performance diagnostics and sensor fault detection and isolation in the presence of nominal and degraded engine health conditions.

  19. Enhancement of the mechanical properties of an aluminum metal matrix nanocomposite by the hybridization technique

    Directory of Open Access Journals (Sweden)

    Kalidindi Sita Rama Raju

    2016-07-01

    Full Text Available A uniform distribution of nanoparticles in the matrix plays a prominent role in improving the composite strength. In the present investigation, two types of launching vehicles, such as aluminum powder (primary and CNTs (secondary, are considered to uniformly carry and launch ultra-fine nanoparticles (13 nm into molten metal. The use of a secondary launching vehicle is identified to promote strengthening compared to a regular primary vehicle, as indicated by the good distribution observed from electron micrographs. CNTs are responsible for hybridizing the composite and also assist strengthening by anchoring to the matrix through the destroyed outer-walls and their axial orientation with the matrix. These results help us in attaining a strength of 197 MPa and a hardness of 93 BHN, with a minimal loss in ductility for the H-3 sample.

  20. FPGA techniques based new hybrid modulation strategies for voltage source inverters.

    Science.gov (United States)

    Sudha, L U; Baskaran, J; Elankurisil, S A

    2015-01-01

    This paper corroborates three different hybrid modulation strategies suitable for single-phase voltage source inverter. The proposed method is formulated using fundamental switching and carrier based pulse width modulation methods. The main tale of this proposed method is to optimize a specific performance criterion, such as minimization of the total harmonic distortion (THD), lower order harmonics, switching losses, and heat losses. The proposed method is articulated using fundamental switching and carrier based pulse width modulation methods. Thus, the harmonic pollution in the power system will be reduced and the power quality will be augmented with better harmonic profile for a target fundamental output voltage. The proposed modulation strategies are simulated in MATLAB r2010a and implemented in a Xilinx spartan 3E-500 FG 320 FPGA processor. The feasibility of these modulation strategies is authenticated through simulation and experimental results.

  1. Fusion techniques for hybrid ground-penetrating radar: electromagnetic induction landmine detection systems

    Science.gov (United States)

    Laffin, Matt; Mohamed, Magdi A.; Etebari, Ali; Hibbard, Mark

    2010-04-01

    Hybrid ground penetrating radar (GPR) and electromagnetic induction (EMI) sensors have advanced landmine detection far beyond the capabilities of a single sensing modality. Both probability of detection (PD) and false alarm rate (FAR) are impacted by the algorithms utilized by each sensing mode and the manner in which the information is fused. Algorithm development and fusion will be discussed, with an aim at achieving a threshold probability of detection (PD) of 0.98 with a low false alarm rate (FAR) of less than 1 false alarm per 2 square meters. Stochastic evaluation of prescreeners and classifiers is presented with subdivisions determined based on mine type, metal content, and depth. Training and testing of an optimal prescreener on lanes that contain mostly low metal anti-personnel mines is presented. Several fusion operators for pre-screeners and classifiers, including confidence map multiplication, will be investigated and discussed for integration into the algorithm architecture.

  2. Technique of performing construction works by machines with hybrid: manual and remote control

    Directory of Open Access Journals (Sweden)

    Sevryugina Nadezhda

    2017-01-01

    Full Text Available The article discusses issues dealing with efficiency of construction work mechanization. It offers a mathematical model for assessment of mutual influence between the members of the ‘construction site-machine-operator’ system triad, that can give a quantitative assessment of how the efficiency of a technological task varies with more comprehensive use of operational capacities of the machine, while lower effect that limiting parameters of production environment and technical condition of the machine have on the operator. The article contains a constructive remote control solution for upgrade of the base machine. It describes the conditions for using the machines with hybrid: manual and remote control at construction sites. There is also an imitation model of operator’s scanning pattern and data experimental research that prove the efficiency of remotely controlled technological operations. The article proves that lower psychological load on the operator and better comfort contribute to positive economic effect and higher quality of the construction process.

  3. Wind Power Forecasting techniques in complex terrain: ANN vs. ANN-CFD hybrid approach

    Science.gov (United States)

    Castellani, Francesco; Astolfi, Davide; Mana, Matteo; Burlando, Massimiliano; Meißner, Cathérine; Piccioni, Emanuele

    2016-09-01

    Due to technology developments, renewable energies are becoming competitive against fossil sources and the number of wind farms is growing, which have to be integrated into power grids. Therefore, accurate power forecast is needed and often operators are charged with penalties in case of imbalance. Yet, wind is a stochastic and very local phenomenon, and therefore hard to predict. It has a high variability in space and time and wind power forecast is challenging. Statistical methods, as Artificial Neural Networks (ANN), are often employed for power forecasting, but they have some shortcomings: they require data sets over several years and are not able to capture tails of wind power distributions. In this work a pure ANN power forecast is compared against a hybrid method, based on the combination of ANN and a physical method using computational fluid dynamics (CFD). The validation case is a wind farm sited in southern Italy in a very complex terrain, with a wide spread turbine layout.

  4. A hybrid fringe analysis technique for the elimination of random noise in interferometric wrapped phase maps

    Science.gov (United States)

    Bhat, Gopalakrishna K.

    1994-10-01

    A fringe analysis technique, which makes use of the spatial filtering property of the Fourier transform method, for the elimination of random impulsive noise in the wrapped phase maps obtained using the phase stepping technique, is presented. Phase noise is converted into intensity noise by transforming the wrapped phase map into a continuous fringe pattern inside the digital image processor. Fourier transform method is employed to filter out the intensity noise and recover the clean wrapped phase map. Computer generated carrier fringes are used to preserve the sign information. This technique makes the two dimensional phase unwrapping process less involved, because it eliminates the local phase fluctuations, which act as pseudo 2π discontinuities. The technique is applied for the elimination of noise in a phase map obtained using electro-optic holography.

  5. Prediction of daily rainfall by a hybrid wavelet-season-neuro technique

    Science.gov (United States)

    Altunkaynak, Abdusselam; Nigussie, Tewodros Assefa

    2015-10-01

    Accurate daily rainfall prediction is required for accurate streamflow prediction, flooding risk analysis, constructing a reliable flood control and early warning system. However, because of its nonlinearity, prediction of daily rainfall with high accuracy and long prediction lead time is difficult. There are many daily rainfall prediction methods in the literature, but they are known to yield inaccurate predictions with short lead time, require many physical parameters and involve complicated mathematical equations with huge computational burden. Recently, artificial neural network has been used for predicting rainfall with the objective of addressing the above mentioned problems. But still, the accuracy has not been satisfactory and predictions are with short lead time. In this study, two methods called combined season-multilayer perceptron (SAS-MP) and hybrid wavelet-season-multilayer perceptron (W-SAS-MP) were developed to enhance prediction accuracy and extend prediction lead time of daily rainfall up to 5 days by using data from two stations in Turkey. These two models were compared with the stand-alone multilayer perceptron and another most commonly used method called combined wavelet-multilayer perceptron (W-MP). The performances of the models were evaluated by using coefficient of determination, coefficient of efficiency and root mean squared error. The SAS-MP model was found to be better than W-MP in most cases, except lead time day 1, where W-MP performed better. Throughout all the lead times, however, the hybrid W-SAS-MP model performed best with CE values of 0.911 and 0.909, respectively, for prediction lead time of 1 day and 0.588 and 0.570, respectively, for prediction lead time of 5 days at Stations 17836 and 17837, respectively, at the model testing (validation) phase. Therefore, W-SAS-MP can be an appropriate tool for enhancing daily rainfall prediction accuracy and extend prediction lead time.

  6. Distributed-parameter problem solved on a hybrid computer by a modified function storage technique

    DEFF Research Database (Denmark)

    Poulsen, N.J.

    1969-01-01

    Describes a method which is based on a function storage technique improved by a number of modifications; it fulfils the two main demands: the solution is based directly on the physical equations, and is accurate within 1%......Describes a method which is based on a function storage technique improved by a number of modifications; it fulfils the two main demands: the solution is based directly on the physical equations, and is accurate within 1%...

  7. A Low Cost Vision Based Hybrid Fiducial Mark Tracking Technique for Mobile Industrial Robots

    OpenAIRE

    Mohammed Y Aalsalem; Wazir Zada Khan; Quratul Ain Arshad

    2012-01-01

    The field of robotic vision is developing rapidly. Robots can react intelligently and provide assistance to user activities through sentient computing. Since industrial applications pose complex requirements that cannot be handled by humans, an efficient low cost and robust technique is required for the tracking of mobile industrial robots. The existing sensor based techniques for mobile robot tracking are expensive and complex to deploy, configure and maintain. Also some of them demand dedic...

  8. Applying Subtractive Hybridization Technique to Enrich and Amplify Tumor-Specific Transcripts of Esophageal Squamous Cell Carcinoma.

    Science.gov (United States)

    Mahmoudian, Reihaneh Alsadat; Abbaszadegan, Mohammad Reza; Gholamin, Mehran

    2017-04-01

    Subtractive hybridization (SH) as an efficient and powerful approach can be applied to isolate differentially expressed transcripts as well as detect of involved mRNAs in various cellular processes, particularly diseases and malignancies. This procedure leads to the enrichment of specific low copy transcripts of tumor cells. Having developed a new approach for SH to isolate tumor specific transcripts, we facilitated discovery of uniquely expressed genes in esophageal squamous cell carcinoma (ESCC). Total RNA was extracted from the fresh tumoral and their adjacent normal tissues, and purified using the Switch Mechanism At the 5' end of Reverse Transcript (SMART) method. Following cDNA synthesis of normal mRNAs using magnetic beads, it was hybridized with tumor mRNAs. To enhance efficiency of subtraction, hybridization was repeated three rounds. Finally, amplification of subtracted tumor-specific transcripts was carried out using in vitro transcription. The subtracted tumoral mRNAs was analyzed quantitatively using real-time PCR for both tumor-specific and housekeeping genes. The subtracted mRNA was confirmed as tumor-specific mRNA pool using RT-PCR and quantitative real-time PCR assessment. The elevated level of tumor-specific transcripts such as MAGE-A4 and CD44 as well as declined copy number of housekeeping genes such as GAPDH, β actin and β2-microglobulin, were confirmed in subtracted tumoral mRNA. The presence of tumor genes was confirmed after the SH procedure. The designed SH method in combination with SMART technique can isolate and amplify high quality tumor-specific transcripts even from small amount of tumor tissues. Removal of common transcripts from the extracted tumoral mRNAs using SH, leads to the enrichment of tumor-specific transcripts. The isolated transcripts are of interest because of their probable roles in ESCC progression and development. In addition, these tumor-specific mRNAs can be applied for future vaccine cancer studies.

  9. An Enhanced Level Set Segmentation for Multichannel Images Using Fuzzy Clustering and Lattice Boltzmann Method

    Directory of Open Access Journals (Sweden)

    Savita Agrawal

    2015-11-01

    Full Text Available In the last decades, image segmentation has proved its applicability in various areas like satellite image processing, medical image processing and many more. In the present scenario the researchers tries to develop hybrid image segmentation techniques to generates efficient segmentation. Due to the development of the parallel programming, the lattice Boltzmann method (LBM has attracted much attention as a fast alternative approach for solving partial differential equations. In this project work, first designed an energy functional based on the fuzzy c-means objective function which incorporates the bias field that accounts for the intensity in homogeneity of the real-world image. Using the gradient descent method, corresponding level set equations are obtained from which we deduce a fuzzy external force for the LBM solver based on the model by Zhao. The method is speedy, robust for denoise, and does not dependent on the position of the initial contour, effective in the presence of intensity in homogeneity, highly parallelizable and can detect objects with or without edges. For the implementation of segmentation techniques defined for gray images, most of the time researchers determines single channel segments of the images and superimposes the single channel segment information on color images. This idea leads to provide color image segmentation using single channel segments of multi channel images. Though this method is widely adopted but doesn’t provide complete true segmentation of multichannel ie color images because a color image contains three different channels for Red, green and blue components. Hence segmenting a color image, by having only single channel segments information, will definitely loose important segment regions of color images. To overcome this problem this paper work starts with the development of Enhanced Level Set Segmentation for single channel Images Using Fuzzy Clustering and Lattice Boltzmann Method. For the

  10. An Enhanced Level Set Segmentation for Multichannel Images Using Fuzzy Clustering and Lattice Boltzmann Method

    Directory of Open Access Journals (Sweden)

    Savita Agrawal

    2014-05-01

    Full Text Available In the last decades, image segmentation has proved its applicability in various areas like satellite image processing, medical image processing and many more. In the present scenario the researchers tries to develop hybrid image segmentation techniques to generates efficient segmentation. Due to the development of the parallel programming, the lattice Boltzmann met hod (LBM has attracted much attention as a fast alternative approach for solving partial differential equations. In this project work, first designed an energy functional based on the fuzzy c-means objective function which incorporates the bias field that accounts for the intensity in homogeneity of the real-world image. Using the gradient descent method, corresponding level set equations are obtained from which we deduce a fuzzy external force for the LBM solver based on the model by Zhao. The method is speedy, robust for denoise, and does not dependent on the position of the initial contour, effective in the presence of intensity in homogeneity, highly parallelizable and can detect objects with or without edges. For the implementation of segmentation techniques defined for gr ay images, most of the time researchers determines single channel segments of the images and superimposes the single channel segment information on color images. This idea leads to provide color image segmentation using single channel segments of multi chann el images. Though this method is widely adopted but doesn’t provide complete true segmentation of multichannel ie color images because a color image contains three different channels for Red, green and blue components. Hence segmenting a color image, b y having only single channel segments information, will definitely loose important segment regions of color images. To overcome this problem this paper work starts with the development of Enhanced Level Set Segmentation for single channel Images Using Fuzzy Clustering and Lattice Boltzmann Method. For the

  11. Electromagnetic self-consistent field initialization and fluid advance techniques for hybrid-kinetic PWFA code Architect

    Science.gov (United States)

    Massimo, F.; Marocchino, A.; Rossi, A. R.

    2016-09-01

    The realization of Plasma Wakefield Acceleration experiments with high quality of the accelerated bunches requires an increasing number of numerical simulations to perform first-order assessments for the experimental design and online-analysis of the experimental results. Particle in Cell codes are the state-of-the-art tools to study the beam-plasma interaction mechanism, but due to their requirements in terms of number of cores and computational time makes them unsuitable for quick parametric scans. Considerable interest has been shown thus in methods which reduce the computational time needed for the simulation of plasma acceleration. Such methods include the use of hybrid kinetic-fluid models, which treat the relativistic bunches as in a PIC code and the background plasma electrons as a fluid. A technique to properly initialize the bunch electromagnetic fields in the time explicit hybrid kinetic-fluid code Architect is presented, as well the implementation of the Flux Corrected Transport scheme for the fluid equations integrated in the code.

  12. HyMaP: A hybrid magnitude-phase approach to unsupervised segmentation of tumor areas in breast cancer histology images

    Directory of Open Access Journals (Sweden)

    Adnan M Khan

    2013-01-01

    Full Text Available Background: Segmentation of areas containing tumor cells in standard H&E histopathology images of breast (and several other tissues is a key task for computer-assisted assessment and grading of histopathology slides. Good segmentation of tumor regions is also vital for automated scoring of immunohistochemical stained slides to restrict the scoring or analysis to areas containing tumor cells only and avoid potentially misleading results from analysis of stromal regions. Furthermore, detection of mitotic cells is critical for calculating key measures such as mitotic index; a key criteria for grading several types of cancers including breast cancer. We show that tumor segmentation can allow detection and quantification of mitotic cells from the standard H&E slides with a high degree of accuracy without need for special stains, in turn making the whole process more cost-effective. Method: Based on the tissue morphology, breast histology image contents can be divided into four regions: Tumor, Hypocellular Stroma (HypoCS, Hypercellular Stroma (HyperCS, and tissue fat (Background. Background is removed during the preprocessing stage on the basis of color thresholding, while HypoCS and HyperCS regions are segmented by calculating features using magnitude and phase spectra in the frequency domain, respectively, and performing unsupervised segmentation on these features. Results: All images in the database were hand segmented by two expert pathologists. The algorithms considered here are evaluated on three pixel-wise accuracy measures: precision, recall, and F1-Score. The segmentation results obtained by combining HypoCS and HyperCS yield high F1-Score of 0.86 and 0.89 with re-spect to the ground truth. Conclusions: In this paper, we show that segmentation of breast histopathology image into hypocellular stroma and hypercellular stroma can be achieved using magnitude and phase spectra in the frequency domain. The segmentation leads to demarcation of tumor

  13. Model Predictive Control techniques with application to photovoltaic, DC Microgrid, and a multi-sourced hybrid energy system

    Science.gov (United States)

    Shadmand, Mohammad Bagher

    Renewable energy sources continue to gain popularity. However, two major limitations exist that prevent widespread adoption: availability and variability of the electricity generated and the cost of the equipment. The focus of this dissertation is Model Predictive Control (MPC) for optimal sized photovoltaic (PV), DC Microgrid, and multi-sourced hybrid energy systems. The main considered applications are: maximum power point tracking (MPPT) by MPC, droop predictive control of DC microgrid, MPC of grid-interaction inverter, MPC of a capacitor-less VAR compensator based on matrix converter (MC). This dissertation firstly investigates a multi-objective optimization technique for a hybrid distribution system. The variability of a high-penetration PV scenario is also studied when incorporated into the microgrid concept. Emerging (PV) technologies have enabled the creation of contoured and conformal PV surfaces; the effect of using non-planar PV modules on variability is also analyzed. The proposed predictive control to achieve maximum power point for isolated and grid-tied PV systems speeds up the control loop since it predicts error before the switching signal is applied to the converter. The low conversion efficiency of PV cells means we want to ensure always operating at maximum possible power point to make the system economical. Thus the proposed MPPT technique can capture more energy compared to the conventional MPPT techniques from same amount of installed solar panel. Because of the MPPT requirement, the output voltage of the converter may vary. Therefore a droop control is needed to feed multiple arrays of photovoltaic systems to a DC bus in microgrid community. Development of a droop control technique by means of predictive control is another application of this dissertation. Reactive power, denoted as Volt Ampere Reactive (VAR), has several undesirable consequences on AC power system network such as reduction in power transfer capability and increase in

  14. Glaucoma detection using novel optic disc localization, hybrid feature set and classification techniques.

    Science.gov (United States)

    Akram, M Usman; Tariq, Anam; Khalid, Shehzad; Javed, M Younus; Abbas, Sarmad; Yasin, Ubaid Ullah

    2015-12-01

    Glaucoma is a chronic and irreversible neuro-degenerative disease in which the neuro-retinal nerve that connects the eye to the brain (optic nerve) is progressively damaged and patients suffer from vision loss and blindness. The timely detection and treatment of glaucoma is very crucial to save patient's vision. Computer aided diagnostic systems are used for automated detection of glaucoma that calculate cup to disc ratio from colored retinal images. In this article, we present a novel method for early and accurate detection of glaucoma. The proposed system consists of preprocessing, optic disc segmentation, extraction of features from optic disc region of interest and classification for detection of glaucoma. The main novelty of the proposed method lies in the formation of a feature vector which consists of spatial and spectral features along with cup to disc ratio, rim to disc ratio and modeling of a novel mediods based classier for accurate detection of glaucoma. The performance of the proposed system is tested using publicly available fundus image databases along with one locally gathered database. Experimental results using a variety of publicly available and local databases demonstrate the superiority of the proposed approach as compared to the competitors.

  15. All-optical delay technique for supporting multiple antennas in a hybrid optical - wireless transmission system

    DEFF Research Database (Denmark)

    Prince, Kamau; Chiuchiarelli, A; Presi, M

    2008-01-01

    We introduce a novel continuously-variable optical delay technique to support beam-forming wireless communications systems using antenna arrays. We demonstrate delay with 64-QAM modulated signals at a rate of 15 Msymbol/sec with 2.5 GHz carrier frequency.......We introduce a novel continuously-variable optical delay technique to support beam-forming wireless communications systems using antenna arrays. We demonstrate delay with 64-QAM modulated signals at a rate of 15 Msymbol/sec with 2.5 GHz carrier frequency....

  16. Acute thrombosis during left main stenting using tap technique in a patient presenting with non-ST-segment elevation acute coronary syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Natarajan, Deepak, E-mail: deepaknatarajan@me.com

    2015-06-15

    This case reports the sudden development of large burden of thrombi in the left anterior descending coronary artery immediately following distal left main stenting using TAP technique in a middle aged man who presented with non ST-segment elevation acute coronary syndrome despite having been administered 7,500 units of unfractionated heparin and being given 325 mg of aspirin and 60 mg of prasugrel prior to the procedure. The thrombi were managed effectively by giving an intra-coronary high bolus dose of tirofiban (25 mcg/kg) without the need for catheter thrombus extraction. Tirofiban intra-venous infusion was maintained for 18 hours, and the patient was discharged in stable condition on the third day. Importantly there is no controlled study on upstream administration of glycoprotein IIb/IIIa inhibitors in addition to the newer more potent anti-platelet agents in patients with unprotected distal left main disease presenting with non ST-segment elevation acute coronary syndrome, nor is there any data on safety and efficacy of mandatory usage of injectable anti-platelet agents at the start of a procedure in a catheterization laboratory in such a setting.

  17. A Hybrid VLM Preceded SLM Technique Using Clipping and Filtering Method for PAPR Reduction in MIMO-OFDM Systems

    Directory of Open Access Journals (Sweden)

    Meenakshi

    2016-07-01

    Full Text Available MIMO-OFDM is an attractive interface for the next generation WLANs, WMAN, 4G and 5G mobile cellular systems. However the performance of the MIMO-OFDM systems is affected by Peak to Average Power Ratio (PAPR. PAPR is the main disadvantage associated with the MIMO-OFDM systems. So far, many techniques have been proposed to reduce the value of PAPR but high PAPR for MIMO-OFDM systems is still a demanding area and a different issue.In this paper, a hybrid VLM precoded SLM scheme using Clipping & Filtering has been proposed to reduce PAPR in MIMO-OFDM systems. And it has been observed that the proposed scheme has achieved a significant gain in PAPR reduction without increasing the system complexity and affecting the error performance of the system

  18. Therapeutic efficacy of a hybrid mandibular advancement device in the management of obstructive sleep apnea assessed with acoustic reflection technique

    Directory of Open Access Journals (Sweden)

    S S Agarwal

    2015-01-01

    Full Text Available Obstructive sleep apnea (OSA is one of the most common forms of sleep-disordered breathing. Various treatment modalities include behavior modification therapy, nasal continuous positive airway pressure (CPAP, oral appliance therapy, and various surgical modalities. Oral appliances are noninvasive and recommended treatment modality for snoring, mild to moderate OSA cases and severe OSA cases when patient is not compliant to CPAP therapy and unwilling for surgery. Acoustic reflection technique (ART is a relatively new modality for three-dimensional assessment of airway caliber in various clinical situations. The accuracy and reproducibility of acoustic rhinometry and acoustic pharyngometry assessment are comparable to computerized tomography and magnetic resonance imaging. This case report highlights the therapeutic efficacy of an innovative customized acrylic hybrid mandibular advancement device in the management of polysomnography diagnosed OSA cases, and the treatment results were assessed by ART.

  19. Hybrid vapor phase-solution phase growth techniques for improved CZT(S,Se) photovoltaic device performance

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Liang-Yi; Gershon, Talia S.; Haight, Richard A.; Lee, Yun Seog

    2016-12-27

    A hybrid vapor phase-solution phase CZT(S,Se) growth technique is provided. In one aspect, a method of forming a kesterite absorber material on a substrate includes the steps of: depositing a layer of a first kesterite material on the substrate using a vapor phase deposition process, wherein the first kesterite material includes Cu, Zn, Sn, and at least one of S and Se; annealing the first kesterite material to crystallize the first kesterite material; and depositing a layer of a second kesterite material on a side of the first kesterite material opposite the substrate using a solution phase deposition process, wherein the second kesterite material includes Cu, Zn, Sn, and at least one of S and Se, wherein the first kesterite material and the second kesterite material form a multi-layer stack of the absorber material on the substrate. A photovoltaic device and method of formation thereof are also provided.

  20. Hybrid vapor phase-solution phase growth techniques for improved CZT(S,Se) photovoltaic device performance

    Science.gov (United States)

    Chang, Liang-Yi; Gershon, Talia S.; Haight, Richard A.; Lee, Yun Seog

    2016-12-27

    A hybrid vapor phase-solution phase CZT(S,Se) growth technique is provided. In one aspect, a method of forming a kesterite absorber material on a substrate includes the steps of: depositing a layer of a first kesterite material on the substrate using a vapor phase deposition process, wherein the first kesterite material includes Cu, Zn, Sn, and at least one of S and Se; annealing the first kesterite material to crystallize the first kesterite material; and depositing a layer of a second kesterite material on a side of the first kesterite material opposite the substrate using a solution phase deposition process, wherein the second kesterite material includes Cu, Zn, Sn, and at least one of S and Se, wherein the first kesterite material and the second kesterite material form a multi-layer stack of the absorber material on the substrate. A photovoltaic device and method of formation thereof are also provided.

  1. Treatment of breast cancer with simultaneous integrated boost in hybrid plan technique. Influence of flattening filter-free beams

    Energy Technology Data Exchange (ETDEWEB)

    Bahrainy, Marzieh; Kretschmer, Matthias; Joest, Vincent; Kasch, Astrid; Wuerschmidt, Florian; Dahle, Joerg; Lorenzen, Joern [Radiologische Allianz, Hamburg (Germany)

    2016-05-15

    The present study compares in silico treatment plans using hybrid plan technique during hypofractionated radiation of mammary carcinoma with simultaneous integrated boost (SIB). The influence of 6 MV photon radiation in flattening filter free (FFF) mode against the clinical standard flattening filter (FF) mode is to be examined. RT planning took place with FF and FFF radiation plans for 10 left-sided breast cancer patients. Hybrid plans were realised with two tangential IMRT fields and one VMAT field. The dose prescription was in line with the guidelines in the ARO-2010-01 study. The dosimetric verification took place with a manufacturer-independent measurement system. Required dose prescriptions for the planning target volumes (PTV) were achieved for both groups. The average dose values of the ipsi- and contralateral lung and the heart did not differ significantly. The overall average incidental dose to the left anterior descending artery (LAD) of 8.24 ± 3.9 Gy in the FFF group and 9.05 ± 3.7 Gy in the FF group (p < 0.05) were found. The dosimetric verifications corresponded to the clinical requirements. FFF-based RT plans reduced the average treatment time by 17 s/fraction. In comparison to the FF-based hybrid plan technique the FFF mode allows further reduction of the average LAD dose for comparable target volume coverage without adverse low-dose exposure of contralateral structures. The combination of hybrid plan technique and 6 MV photon radiation in the FFF mode is suitable for use with hypofractionated dose schemes. The increased dose rate allows a substantial reduction of treatment time and thus beneficial application of the deep inspiration breath hold technique. (orig.) [German] Vergleich der ''In-silico''-Bestrahlungsplaene der klinisch etablierten Hybridplan-Technik bei hypofraktionierter Bestrahlung des Mammakarzinoms mit simultan integriertem Boost (SIB). Untersucht wird der Einfluss von 6MV-Photonenstrahlung im Flattening

  2. Comparison and performance analysis of closed loop controlled nonlinear system connected PWM inverter based on hybrid technique

    Directory of Open Access Journals (Sweden)

    V.M. Deshmukh

    2015-05-01

    Full Text Available This paper proposed closed loop control of nonlinear system connected inverter based on the optimal neural controller (ONC. The novelty of the proposed method rests on the hybrid technique which is the combined performance of both, particle swarm optimization (PSO technique and Radial basis function neural network (RBFNN. It effectively optimizes the feasible solutions by updating the generations, by taking lesser time with greater reliability. In the proposed method, the PSO generates the dataset according to different loading conditions. The RBFNN is trained by using the target control signals along with the corresponding input load voltage error and change in error. Depending on the load variations, the RBFNN predicts the exact control signals of the inverter during the testing time. Since experimentation and comparison of such inverter models on hardware being relatively expensive, the proposed method is implemented in the MATLAB/Simulink platform and the performance has been validated through the comparison analysis with the conventional techniques. The comparison results have proved the superiority of the proposed method.

  3. 3D printing of high-resolution PLA-based structures by hybrid electrohydrodynamic and fused deposition modeling techniques

    Science.gov (United States)

    Zhang, Bin; Seong, Baekhoon; Nguyen, VuDat; Byun, Doyoung

    2016-02-01

    Recently, the three-dimensional (3D) printing technique has received much attention for shape forming and manufacturing. The fused deposition modeling (FDM) printer is one of the various 3D printers available and has become widely used due to its simplicity, low-cost, and easy operation. However, the FDM technique has a limitation whereby its patterning resolution is too low at around 200 μm. In this paper, we first present a hybrid mechanism of electrohydrodynamic jet printing with the FDM technique, which we name E-FDM. We then develop a novel high-resolution 3D printer based on the E-FDM process. To determine the optimal condition for structuring, we also investigated the effect of several printing parameters, such as temperature, applied voltage, working height, printing speed, flow-rate, and acceleration on the patterning results. This method was capable of fabricating both high resolution 2D and 3D structures with the use of polylactic acid (PLA). PLA has been used to fabricate scaffold structures for tissue engineering, which has different hierarchical structure sizes. The fabrication speed was up to 40 mm/s and the pattern resolution could be improved to 10 μm.

  4. Real-time hybrid simulation technique for performance evaluation of full-scale sloshing dampers in wind turbines

    Science.gov (United States)

    Zhang, Zili; Basu, Biswajit; Nielsen, Saren R. K.

    2016-09-01

    As a variation of the pseudodynamic testing technique, the real-time hybrid simulation (RTHS) technique is executed in real time, thus allowing investigation of structural systems with rate-dependent components. In this paper, the RTHS is employed for performance evaluation of full-scale liquid sloshing dampers in multi-megawatt wind turbines, where the tuned liquid damper (TLD) is manufactured and tested as the physical substructure while the wind turbine is treated as the numerical substructure and modelled in the computer using a 13-degree-of-freedom (13-DOF) aeroelastic model. Wind turbines with 2 MW and 3 MW capacities have been considered under various turbulent wind conditions. Extensive parametric studies have been performed on the TLD, e.g., various tuning ratios by changing the water level, TLD without and with damping screens (various mesh sizes of the screen considered), and TLD with flat and sloped bottoms. The present study provides useful guidelines for employing sloshing dampers in large wind turbines, and indicates huge potentials of applying RTHS technique in the area of wind energy.

  5. Screening for cardiac HERG potassium channel interacting proteins using the yeast two-hybrid technique.

    Science.gov (United States)

    Ma, Qingyan; Yu, Hong; Lin, Jijin; Sun, Yifan; Shen, Xinyuan; Ren, Li

    2014-02-01

    The human ERG protein (HERG or Kv 11.1) encoded by the human ether-a-go-go-related gene (herg) is the pore-forming subunit of the cardiac delayed rectifier potassium current (IKr) responsible for action potential (AP) repolarization. Mutations in HERG lead to long-QT syndrome, a major cause of arrhythmias. Protein-protein interactions are fundamental for ion channel trafficking, membrane localization, and functional modulation. To identify proteins involved in the regulation of the HERG channel, we conducted a yeast two-hybrid screen of a human heart cDNA library using the C-terminus or N-terminus of HERG as bait. Fifteen proteins were identified as HERG amino terminal (HERG-NT)-interacting proteins, including Caveolin-1 (a membrane scaffold protein with multiple interacting partners, including G-proteins, kinases and NOS), the zinc finger protein, FHL2 and PTPN12 (a non-receptor tyrosine phosphatase). Eight HERG carboxylic terminal (HERG-CT)-interacting proteins were also identified, including the NF-κB-interacting protein myotrophin, We have identified multiple potential interacting proteins that may regulate cardiac IKr through cytoskeletal interactions, G-protein modulation, phosphorylation and downstream second messenger and transcription cascades. These findings provide further insight into dynamic modulation of HERG under physiological conditions and arrhythmogenesis.

  6. Speeding-up the hybrid video watermarking techniques in the DWT domain

    Science.gov (United States)

    Chammem, A.; Mitrea, M.; Preteux, F.

    2010-01-01

    The watermarking state of the art exhibits the hybrid methods combining spread spectrum and side information principles. The present study is focussed on speeding up such an algorithm (jointly patented by SFR - Vodafone Group and Institut Telecom). The dead lock on the reference method is first identified: the embedding module accounts for 90% of the whole watermarking chain and that more than 99% of this time is spent on applying an attack procedure (required in order to grant a good robustness to this method). The main issue of the present study is to deploy Monte Carlo generators accurately representing the watermarking attacks. In this respect, two difficulties should be overcome. First, accurate statistical models for the watermarking attacks should be obtained. Secondly, efficient Monte Carlo simulators should be deployed for these models. The last part of the study was devoted to the experimental validations. The mark is inserted in the (9,7) DWT representation of video sequence. Several types of attacks have been considered (linear and non-linear filters, geometrical transformations, ...). The quantitative results proved that the data payload, transparency and robustness properties have been inherited from the reference method. However, the watermarking speed was increased by a factor of 80.

  7. Entrapment of glucoamylase by sol-gel technique in PhTES/TEOS hybrid matrixes

    Directory of Open Access Journals (Sweden)

    B. Vlad-Oros

    2007-12-01

    Full Text Available Mesoporous silica particles were prepared by the sol-gel method from different alkoxysilane precursors and used as a host matrix for encapsulation of glucoamylase, an enzyme widely used in fermentative industry. The aim was to investigate the physico-chemical properties of the different silica powders and their effect on the enzyme kinetics. The encapsulated enzymes followed Michaelis-Menten kinetics. The Michaelis constant (KM and the maximum rate of starch hydrolysis reaction (Vmax were calculated according to the Michaelis-Menten and Lineweaver-Burke plots. The values of the Michaelis constant (KM of the encapsulated enzymes were higher than those of the free enzyme. The temperature and pH infl uence on the activity of free and immobilized glucoamylase were also compared. The results of this study show that the enzymes immobilized in organic/inorganic hybrid silica matrixes (obtained by the sol-gel method, allowing the entrapped glucoamylase to retain its biological activity, are suitable for many different applications, (medicinal, clinical, analytical.

  8. Prediction of peak ground acceleration of Iran's tectonic regions using a hybrid soft computing technique

    Directory of Open Access Journals (Sweden)

    Mostafa Gandomi

    2016-01-01

    Full Text Available A new model is derived to predict the peak ground acceleration (PGA utilizing a hybrid method coupling artificial neural network (ANN and simulated annealing (SA, called SA-ANN. The proposed model relates PGA to earthquake source to site distance, earthquake magnitude, average shear-wave velocity, faulting mechanisms, and focal depth. A database of strong ground-motion recordings of 36 earthquakes, which happened in Iran's tectonic regions, is used to establish the model. For more validity verification, the SA-ANN model is employed to predict the PGA of a part of the database beyond the training data domain. The proposed SA-ANN model is compared with the simple ANN in addition to 10 well-known models proposed in the literature. The proposed model performance is superior to the single ANN and other existing attenuation models. The SA-ANN model is highly correlated to the actual records (R = 0.835 and ρ = 0.0908 and it is subsequently converted into a tractable design equation.

  9. A novel reconstruction method for giant incisional hernia: Hybrid laparoscopic technique

    Directory of Open Access Journals (Sweden)

    G Ozturk

    2015-01-01

    Full Text Available Background and Objectives: Laparoscopic reconstruction of ventral hernia is a popular technique today. Patients with large defects have various difficulties of laparoscopic approach. In this study, we aimed to present a new reconstruction technique that combines laparoscopic and open approach in giant incisional hernias. Materials and Methods: Between January 2006 and August 2012, 28 patients who were operated consequently for incisional hernia with defect size over 10 cm included in this study and separated into two groups. Group 1 (n = 12 identifies patients operated with standard laparoscopic approach, whereas group 2 (n = 16 labels laparoscopic technique combined with open approach. Patients were evaluated in terms of age, gender, body mass index (BMI, mean operation time, length of hospital stay, surgical site infection (SSI and recurrence rate. Results: There are 12 patients in group 1 and 16 patients in group 2. Mean length of hospital stay and SSI rates are similar in both groups. Postoperative seroma formation was observed in six patients for group 1 and in only 1 patient for group 2. Group 1 had 1 patient who suffered from recurrence where group 2 had no recurrence. Discussion: Laparoscopic technique combined with open approach may safely be used as an alternative method for reconstruction of giant incisional hernias.

  10. Hybrid microelectronic technology

    Science.gov (United States)

    Moran, P.

    Various areas of hybrid microelectronic technology are discussed. The topics addressed include: basic thick film processing, thick film pastes and substrates, add-on components and attachment methods, thin film processing, and design of thick film hybrid circuits. Also considered are: packaging hybrid circuits, automating the production of hybrid circuits, application of hybrid techniques, customer's view of hybrid technology, and quality control and assurance in hybrid circuit production.

  11. Hybrid dynamic radioactive particle tracking (RPT) calibration technique for multiphase flow systems

    Science.gov (United States)

    Khane, Vaibhav; Al-Dahhan, Muthanna H.

    2017-04-01

    The radioactive particle tracking (RPT) technique has been utilized to measure three-dimensional hydrodynamic parameters for multiphase flow systems. An analytical solution to the inverse problem of the RPT technique, i.e. finding the instantaneous tracer positions based upon instantaneous counts received in the detectors, is not possible. Therefore, a calibration to obtain a counts-distance map is needed. There are major shortcomings in the conventional RPT calibration method due to which it has limited applicability in practical applications. In this work, the design and development of a novel dynamic RPT calibration technique are carried out to overcome the shortcomings of the conventional RPT calibration method. The dynamic RPT calibration technique has been implemented around a test reactor with 1foot in diameter and 1 foot in height using Cobalt-60 as an isotopes tracer particle. Two sets of experiments have been carried out to test the capability of novel dynamic RPT calibration. In the first set of experiments, a manual calibration apparatus has been used to hold a tracer particle at known static locations. In the second set of experiments, the tracer particle was moved vertically downwards along a straight line path in a controlled manner. The obtained reconstruction results about the tracer particle position were compared with the actual known position and the reconstruction errors were estimated. The obtained results revealed that the dynamic RPT calibration technique is capable of identifying tracer particle positions with a reconstruction error between 1 to 5.9 mm for the conditions studied which could be improved depending on various factors outlined here.

  12. Establishment of Relationships between Material Design and Product Design Domains by Hybrid FEM-ANN Technique

    CERN Document Server

    Prakash, K Soorya; Raj, M Joseph Malvin

    2010-01-01

    In this paper, research on AI based modeling technique to optimize development of new alloys with necessitated improvements in properties and chemical mixture over existing alloys as per functional requirements of product is done. The current research work novels AI in lieu of predictions to establish association between material and product customary. Advanced computational simulation techniques like CFD, FEA interrogations are made viable to authenticate product dynamics in context to experimental investigations. Accordingly, the current research is focused towards binding relationships between material design and product design domains. The input to feed forward back propagation prediction network model constitutes of material design features. Parameters relevant to product design strategies are furnished as target outputs. The outcomes of ANN shows good sign of correlation between material and product design domains. The study enriches a new path to illustrate material factors at the time of new product d...

  13. On Potentials and Limitations of a Hybrid WLAN-RFID Indoor Positioning Technique

    Directory of Open Access Journals (Sweden)

    Silverio C. Spinella

    2010-01-01

    Full Text Available This paper addresses the important issue of position estimation in indoor environments. Starting point of the research is positioning techniques that exploit the knowledge of power levels of RF signals from multiple 802.11 WLAN APs (Access Points. In particular, the key idea in this paper is to enhance the performance of a WLAN fingerprinting approach by coupling it to a RFID-based procedure. WLAN and RFID technologies are synergistically used to provide a platform for a more performing positioning process, in which the very strong identification capabilities of the RFID technology allow to increase the accuracy of positioning systems via WLAN fingerprinting. The algorithm performance is assessed through general and repeatable experimental campaigns, during which the main algorithm parameters are dimensioned. The results testify both to the feasibility of the solution and to its higher accuracy (attainable at very reduced costs compared to traditional positioning techniques.

  14. Evaluation and Optimization Study on a Hybrid EOR Technique Named as Chemical-Alternating-Foam Floods

    Directory of Open Access Journals (Sweden)

    Xu Xingguang

    2017-01-01

    Full Text Available This work presents a novel Enhanced Oil Recovery (EOR method called Chemical-Alternating-Foam (CAF floods in order to overcome the drawbacks of the conventional foam flooding such as insufficient amount of in-situ foams, severe foam collapse and surfactant retention. The first part of this research focused on the comparison of conventional foam floods and CAF floods both of which had the same amount of gas and chemicals. It showed that: (1 CAF floods possessed the much greater Residual Resistance Factor (RRF at elevated temperature; (2 the accumulative oil recovery of the CAF floods was 10%-15% higher than that of the conventional foam flooding. After 1.8 Pore Volume (PV injection, the oil recovery reached the plateau for both methods; (3 CAF floods yielded the most amount of incremental oil at the 98% water cut (water content in the effluent, while the continuous foam floods achieved the best performance at 60% water cut. The second part of this work determined the optimal foam quality (gas/liquid ratio or the volume percent gas within foam, chemical/foam slug size ratio, cycle number and injection sequence for the CAF floods. It was found that the CAF was endowed with the peak performance if the foam quality, chemical/foam slug size ratio, cycle number was fixed at 80%, 1:1 and 3 respectively with the chemical slug being introduced ahead of the foam slug. Through systematic and thorough research, the proposed hybrid process has been approved to be a viable and effective method significantly strengthening the conventional foam flooding.

  15. High process yield rates of thermoplastic nanofluidic devices using a hybrid thermal assembly technique.

    Science.gov (United States)

    Uba, Franklin I; Hu, Bo; Weerakoon-Ratnayake, Kumuditha; Oliver-Calixte, Nyote; Soper, Steven A

    2015-02-21

    Over the past decade, thermoplastics have been used as alternative substrates to glass and Si for microfluidic devices because of the diverse and robust fabrication protocols available for thermoplastics that can generate high production rates of the desired structures at low cost and with high replication fidelity, the extensive array of physiochemical properties they possess, and the simple surface activation strategies that can be employed to tune their surface chemistry appropriate for the intended application. While the advantages of polymer microfluidics are currently being realized, the evolution of thermoplastic-based nanofluidic devices is fraught with challenges. One challenge is assembly of the device, which consists of sealing a cover plate to the patterned fluidic substrate. Typically, channel collapse or substrate dissolution occurs during assembly making the device inoperable resulting in low process yield rates. In this work, we report a low temperature hybrid assembly approach for the generation of functional thermoplastic nanofluidic devices with high process yield rates (>90%) and with a short total assembly time (16 min). The approach involves thermally sealing a high T(g) (glass transition temperature) substrate containing the nanofluidic structures to a cover plate possessing a lower T(g). Nanofluidic devices with critical feature sizes ranging between 25-250 nm were fabricated in a thermoplastic substrate (T(g) = 104 °C) and sealed with a cover plate (T(g) = 75 °C) at a temperature significantly below the T(g) of the substrate. Results obtained from sealing tests revealed that the integrity of the nanochannels remained intact after assembly and devices were useful for fluorescence imaging at high signal-to-noise ratios. The functionality of the assembled devices was demonstrated by studying the stretching and translocation dynamics of dsDNA in the enclosed thermoplastic nanofluidic channels.

  16. Development of a wireless bridge monitoring system for condition assessment using hybrid techniques

    Science.gov (United States)

    Whelan, Matthew J.; Fuchs, Michael P.; Gangone, Michael V.; Janoyan, Kerop D.

    2007-04-01

    The introduction and development of wireless sensor network technology has resulted in rapid growth within the field of structural health monitoring (SHM), as the dramatic cable costs associated with instrumentation of large civil structures is potentially alleviated. Traditionally, condition assessment of bridge structures is accomplished through the use of either vibration measurements or strain sensing. One approach is through quantifying dynamic characteristics and mode shapes developed through the use of relatively dense arrays of accelerometers. Another widely utilized method of condition assessment is bridge load rating, which is enabled through the use of strain sensors. The Wireless Sensor Solution (WSS) developed specifically for diagnostic bridge monitoring provides a hybrid system that interfaces with both accelerometers and strain sensors to facilitate vibration-based bridge evaluation as well as load rating and static analysis on a universal platform. This paper presents the development and testing of a wireless bridge monitoring system designed within the Laboratory for Intelligent Infrastructure and Transportation Technologies (LIITT) at Clarkson University. The system interfaces with low-cost MEMS accelerometers using custom signal conditioning for amplification and filtering tailored to the spectrum of typical bridge vibrations, specifically from ambient excitation. Additionally, a signal conditioning and high resolution ADC interface is provided for strain gauge sensors. To permit compensation for the influence of temperature, thermistor-based temperature sensing is also enabled. In addition to the hardware description, this paper presents features of the software applications and host interface developed for flexible, user-friendly in-network control of and acquisition from the sensor nodes. The architecture of the software radio protocol is also discussed along with results of field deployments including relatively large-scale networks and

  17. Hybrid Machine Learning Technique for Forecasting Dhaka Stock Market Timing Decisions

    OpenAIRE

    Shipra Banik; Khodadad Khan, A. F. M.; Mohammad Anwer

    2014-01-01

    Forecasting stock market has been a difficult job for applied researchers owing to nature of facts which is very noisy and time varying. However, this hypothesis has been featured by several empirical experiential studies and a number of researchers have efficiently applied machine learning techniques to forecast stock market. This paper studied stock prediction for the use of investors. It is always true that investors typically obtain loss because of uncertain investment purposes and unsigh...

  18. A HYBRID TECHNIQUE FOR PAPR REDUCTION OF OFDM USING DHT PRECODING WITH PIECEWISE LINEAR COMPANDING

    Directory of Open Access Journals (Sweden)

    Thammana Ajay

    2016-06-01

    Full Text Available Orthogonal Frequency Division Multiplexing (OFDM is a fascinating approach for wireless communication applications which require huge amount of data rates. However, OFDM signal suffers from its large Peak-to-Average Power Ratio (PAPR, which results in significant distortion while passing through a nonlinear device, such as a transmitter high power amplifier (HPA. Due to this high PAPR, the complexity of HPA as well as DAC also increases. For the reduction of PAPR in OFDM many techniques are available. Among them companding is an attractive low complexity technique for the OFDM signal’s PAPR reduction. Recently, a piecewise linear companding technique is recommended aiming at minimizing companding distortion. In this paper, a collective piecewise linear companding approach with Discrete Hartley Transform (DHT method is expected to reduce peak-to-average of OFDM to a great extent. Simulation results shows that this new proposed method obtains significant PAPR reduction while maintaining improved performance in the Bit Error Rate (BER and Power Spectral Density (PSD compared to piecewise linear companding method.

  19. Well-defined functional mesoporous silica/polymer hybrids prepared by an ICAR ATRP technique integrated with bio-inspired polydopamine chemistry for lithium isotope separation.

    Science.gov (United States)

    Liu, Yuekun; Liu, Xuegang; Ye, Gang; Song, Yang; Liu, Fei; Huo, Xiaomei; Chen, Jing

    2017-05-09

    Mesoporous silica/polymer hybrids with well-preserved mesoporosity were prepared by integrating the initiators for continuous activator regeneration (ICAR) atom transfer radical polymerization (ATRP) technique with the bio-inspired polydopamine (PDA) chemistry. By manipulating the auto-oxidative polymerization of dopamine, uniform PDA layers were deposited on the surfaces and pore walls of ordered mesoporous silicas (OMSs), thereby promoting the immobilization of ATRP initiators. Poly(glycidyl methacrylate) (PGMA) brushes were then grown from the OMSs by using the ICAR ATRP technique. The evolution of the mesoporous silica/polymer hybrids during synthesis, in terms of morphology, structure, surface and porous properties, was detailed. And, parameters influencing the controlled growth of polymer chains in the ICAR ATRP system were studied. Taking advantage of the abundant epoxy groups in the PGMA platform, post-functionalization of the mesoporous silica/polymer hybrids by the covalent attachment of macrocyclic ligands for the adsorptive separation of lithium isotopes was realized. Adsorption behavior of the functionalized hybrids toward lithium ions was fully investigated, highlighting the good selectivity, and effects of temperature, solvent and counter ions. The ability for lithium isotope separation was evaluated. A higher separation factor could be obtained in systems with softer counter anions and lower polarity solvents. More importantly, due to the versatility of the ICAR ATRP technique, combined with the non-surface specific PDA chemistry, the methodology established in this work would provide new opportunities for the preparation of advanced organic-inorganic porous hybrids for broadened applications.

  20. 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)

  1. 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)

  2. A sixth order hybrid finite difference scheme based on the minimized dispersion and controllable dissipation technique

    Science.gov (United States)

    Sun, Zhen-sheng; Luo, Lei; Ren, Yu-xin; Zhang, Shi-ying

    2014-08-01

    The dispersion and dissipation properties of a scheme are of great importance for the simulation of flow fields which involve a broad range of length scales. In order to improve the spectral properties of the finite difference scheme, the authors have previously proposed the idea of optimizing the dispersion and dissipation properties separately and a fourth order scheme based on the minimized dispersion and controllable dissipation (MDCD) technique is thus constructed [29]. In the present paper, we further investigate this technique and extend it to a sixth order finite difference scheme to solve the Euler and Navier-Stokes equations. The dispersion properties of the scheme is firstly optimized by minimizing an elaborately designed integrated error function. Then the dispersion-dissipation condition which is newly derived by Hu and Adams [30] is introduced to supply sufficient dissipation to damp the unresolved wavenumbers. Furthermore, the optimized scheme is blended with an optimized Weighted Essentially Non-Oscillation (WENO) scheme to make it possible for the discontinuity-capturing. In this process, the approximation-dispersion-relation (ADR) approach is employed to optimize the spectral properties of the nonlinear scheme to yield the true wave propagation behavior of the finite difference scheme. Several benchmark test problems, which include broadband fluctuations and strong shock waves, are solved to validate the high-resolution, the good discontinuity-capturing capability and the high-efficiency of the proposed scheme.

  3. A Hybrid Approach for Detecting Suspicious Accounts in Money Laundering Using Data Mining Techniques

    Directory of Open Access Journals (Sweden)

    Ch. Suresh

    2016-05-01

    Full Text Available Money laundering is a criminal activity to disguise black money as white money. It is a process by which illegal funds and assets are converted into legitimate funds and assets. Money Laundering occurs in three stages: Placement, Layering, and Integration. It leads to various criminal activities like Political corruption, smuggling, financial frauds, etc. In India there is no successful Anti Money laundering techniques which are available. The Reserve Bank of India (RBI, has issued guidelines to identify the suspicious transactions and send it to Financial Intelligence Unit (FIU. FIU verifies if the transaction is actually suspicious or not. This process is time consuming and not suitable to identify the illegal transactions that occurs in the system. To overcome this problem we propose an efficient Anti Money Laundering technique which can able to identify the traversal path of the Laundered money using Hash based Association approach and successful in identifying agent and integrator in the layering stage of Money Laundering by Graph Theoretic Approach.

  4. Development and validation of a hybrid simulation technique for cone beam CT: application to an oral imaging system

    Science.gov (United States)

    Zhang, G.; Pauwels, R.; Marshall, N.; Shaheen, E.; Nuyts, J.; Jacobs, R.; Bosmans, H.

    2011-09-01

    This paper proposes a hybrid technique to simulate the complete chain of an oral cone beam computed tomography (CBCT) system for the study of both radiation dose and image quality. The model was developed around a 3D Accuitomo 170 unit (J Morita, Japan) with a tube potential range of 60-90 kV. The Monte Carlo technique was adopted to simulate the x-ray generation, filtration and collimation. Exact dimensions of the bow-tie filter were estimated iteratively using experimentally acquired flood images. Non-flat radiation fields for different exposure settings were mediated via 'phase spaces'. Primary projection images were obtained by ray tracing at discrete energies and were fused according to the two-dimensional energy modulation templates derived from the phase space. Coarse Monte Carlo simulations were performed for scatter projections and the resulting noisy images were smoothed by Richardson-Lucy fitting. Resolution and noise characteristics of the flat panel detector were included using the measured modulation transfer function (MTF) and the noise power spectrum (NPS), respectively. The Monte Carlo dose calculation was calibrated in terms of kerma free-in-air about the isocenter, using an ionization chamber, and was subsequently validated by comparison against the measured air kerma in water at various positions of a cylindrical water phantom. The resulting dose discrepancies were found <10% for most cases. Intensity profiles of the experimentally acquired and simulated projection images of the water phantom showed comparable fractional increase over the common area as changing from a small to a large field of view, suggesting that the scatter was accurately accounted. Image validation was conducted using two small phantoms and the built-in quality assurance protocol of the system. The reconstructed simulated images showed high resemblance on contrast resolution, noise appearance and artifact pattern in comparison to experimentally acquired images, with <5

  5. A novel technique to neutralize the Yawing moment due to asymmetric thrust in a hybrid buoyant aircraft

    Science.gov (United States)

    Haque, Anwar U.; Asrar, Waqar; Omar, Ashraf A.; Sulaeman, Erwin; J. S Ali, Mohamed

    2016-03-01

    Dorsal fin is used in swimming animals like shark for the generation of thrust as well as to meet the requirement of the lateral stability. In the case of aircraft, rudders are normally used for the said requirement. In the present work, this nature inspired idea is explored for its application to neutralize the unavoidable asymmetric thrust produced by the twin engines of a hybrid buoyant aircraft. First, the estimation of asymmetric thrust is obtained with the help of analytical techniques for maximum thrust condition at 4 degree angle of attack. The moment generated by it is utilized for the sizing of a dorsal fin which looks similar to a tapered wing and is placed aft of the center of gravity. Wind tunnel testing at subsonic speed is carried out to explore the design features of this rotatable dorsal fin. It is found that a small rotation of 5 degree can generate the required moment. However, such rotation requires a complete pneumatic/electro-mechanical system and an alternative of it is to use a cambered airfoil for the dorsal fin installed at fixed location. Such a flow controlling device can also be used as an antenna mast, which is commonly installed out the fuselage of the aircraft for communication purposes. Moreover, by incorporating this technique, a pilot doesn't have to put an extra effort to make the aircraft stable in the presence of side wind.

  6. Research on Theories and Techniques of Irrigation for Safeguarding Seed Production of Two-Line Hybrid Rice

    Institute of Scientific and Technical Information of China (English)

    ZOU Jiang-shi; L(U) Chuan-gen; YAO Ke-min; HU Ning; XIA Shi-jian

    2006-01-01

    By inducing frequency, intensity and duration of lower temperature in the middle and last ten-day periods in August in the rice-growing areas of southern China, increasing temperature for safe seed production was defined as 2℃. During the sensitive period of fertility, characters of panicle height and canopy structure of TGMS rice, Pei'ai64S, were measured.Results showed that temperature changes caused by irrigation in fields were below 40 cm of rice plant, and heating effect was significant at 20 cm when the temperature was increased by 3.1℃. For the present study, the following irrigation techniques were put forth: the water depth of 15-20 cm, current water used, irrigating after 17:00 and bailing at 10:00 in sunny or cloudy weather, irrigating on whole day, in shady or rainy weather, increasing inflows and outflows in large fields. In the present experiment, pollen fertility and self-fertilized seed setting rate accepted that the techniques were feasible and effective for against lower temperature and safeguarding seed production of two-line hybrid rice.

  7. A novel technique to neutralize the Yawing moment due to asymmetric thrust in a hybrid buoyant aircraft

    Directory of Open Access Journals (Sweden)

    Haque Anwar U

    2016-01-01

    Full Text Available Dorsal fin is used in swimming animals like shark for the generation of thrust as well as to meet the requirement of the lateral stability. In the case of aircraft, rudders are normally used for the said requirement. In the present work, this nature inspired idea is explored for its application to neutralize the unavoidable asymmetric thrust produced by the twin engines of a hybrid buoyant aircraft. First, the estimation of asymmetric thrust is obtained with the help of analytical techniques for maximum thrust condition at 4 degree angle of attack. The moment generated by it is utilized for the sizing of a dorsal fin which looks similar to a tapered wing and is placed aft of the center of gravity. Wind tunnel testing at subsonic speed is carried out to explore the design features of this rotatable dorsal fin. It is found that a small rotation of 5 degree can generate the required moment. However, such rotation requires a complete pneumatic/electro-mechanical system and an alternative of it is to use a cambered airfoil for the dorsal fin installed at fixed location. Such a flow controlling device can also be used as an antenna mast, which is commonly installed out the fuselage of the aircraft for communication purposes. Moreover, by incorporating this technique, a pilot doesn’t have to put an extra effort to make the aircraft stable in the presence of side wind.

  8. Optimizing an Industrial Scale Naphtha Catalytic Reforming Plant Using a Hybrid Artificial Neural Network and Genetic Algorithm Technique

    Directory of Open Access Journals (Sweden)

    Sepehr Sadighi

    2015-07-01

    Full Text Available In this paper, a hybrid model for estimating the activity of a commercial Pt-Re/Al2O3 catalyst in an industrial scale heavy naphtha catalytic-reforming unit (CRU is presented. This model is also capable of predicting research octane number (RON and yield of gasoline. In the proposed model, called DANN, the decay function of heterogeneous catalysts is combined with a recurrent-layer artificial neural network. During a life cycle (919 days, fifty-eight points are selected for building and training the DANN (60%, nineteen data points for testing (20%, and the remained ones for validating steps. Results show that DANN can acceptably estimate the activity of catalyst during its life in consideration of all process variables. Moreover, it is confirmed that the proposed model is capable of predicting RON and yield of gasoline for unseen (validating data with AAD% (average absolute deviation of 0.272% and 0.755%, respectively. After validating the model, the octane barrel level (OCB of the plant is maximized by manipulating the inlet temperature of reactors, and hydrogen to hydrocarbon molar ratio whilst all process limitations are taken into account. During a complete life cycle results show that the decision variables, generated by the optimization program, can increase the RON, process yield and OCB of CRU to about 1.15%, 3.21%, and 4.56%, respectively. © 2015 BCREC UNDIP. All rights reserved.Received: 27th July 2014; Revised: 31st May 2015; Accepted: 31th May 2015 How to Cite: Sadighi, S., Mohaddecy, R.S., Norouzian, A. (2015. Optimizing an Industrial Scale Naphtha Catalytic Reforming Plant Using a Hybrid Artificial Neural Network and Genetic Algorithm Technique. Bulletin of Chemical Reaction Engineering & Catalysis, 10(2: 210-220. (doi:10.9767/bcrec.10.2.7171.210-220 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.10.2.7171.210-220  

  9. Rapid full Mueller matrix imaging polarimetry based on the hybrid phase modulation technique

    Science.gov (United States)

    Han, Chien-Yuan; Du, Cheng-You; Jhou, Jhe-Yi

    2017-01-01

    In this work, we present a novel method of Mueller matrix imaging polarimetry, which comprises dual liquid crystal variable retarders at the polarization generation portion and a photoelastic modulator at the polarization analysis portion. The light source can be operated either in the continuous mode, which provides an in-situ calibration process for the liquid crystal variable retarders, or in the pulse mode to deduce the full two-dimensional Mueller matrix with 16 images from the camera. We measured the Mueller matrix images of air as a standard test, as well as a quarter wave plate to determine its azimuthal angle and phase retardation by the polar decomposition technique. Finally, the decomposed Mueller matrix images of a biopolymer specimen with the conformational change produced by heat treatment are presented.

  10. MULTILEVEL APPROACH OF CBIR TECHNIQUES FOR VEGETABLE CLASSIFICATION USING HYBRID IMAGE FEATURES

    Directory of Open Access Journals (Sweden)

    D. Latha

    2016-02-01

    Full Text Available CBIR is a technique to retrieve images semantically relevant to query image from an image database. The challenge in CBIR is to develop a method that should increase the retrieval accuracy and reduce the retrieval time. In order to improve the retrieval accuracy and runtime, a multilevel CBIR approach is proposed in this paper. In the first level, the color attributes like mean and standard deviations are proposed to calculate on HSV color space to retrieve the images with minimum disparity distance from the database. In order to minimize search area, in the second level Local Ternary Pattern is proposed on images which were selected from the first level. Experimental results and comparisons demonstrate the superiority of the proposed approach.

  11. A Hybrid Model for the Mid-Long Term Runoff Forecasting by Evolutionary Computaion Techniques

    Institute of Scientific and Technical Information of China (English)

    Zou Xiu-fen; Kang Li-shan; Cae Hong-qing; Wu Zhi-jian

    2003-01-01

    The mid-long term hydrology forecasting is one of most challenging problems in hydrological studies. This paper proposes an efficient dynamical system prediction model using evolutionary computation techniques. The new model overcomes some disadvantages of conventional hydrology fore casting ones. The observed data is divided into two parts: the slow "smooth and steady" data, and the fast "coarse and fluctuation" data. Under the divide and conquer strategy, the behavior of smooth data is modeled by ordinary differential equations based on evolutionary modeling, and that of the coarse data is modeled using gray correlative forecasting method. Our model is verified on the test data of the mid-long term hydrology forecast in tbe northeast region of China. The experimental results show that the model is superior to gray system prediction model (GSPM).

  12. Evaluation of intrusive mechanics of the type "segmented arch" on a macerated human skull using the laser reflection technique and holographic interferometry.

    Science.gov (United States)

    Dermaut, L R; Vanden Bulcke, M M

    1986-03-01

    Twelve different systems of intrusion, based on the principle of the "segmented arch," were evaluated on a macerated human skull. The number of teeth involved in the anterior unit and the location of the application points of intrusive force were considered to be variables. Initial displacements of the anterior teeth after loading were registered by means of the laser reflection technique and double exposure holographic recordings. An attempt was made to define "this" intrusive system, achieving the most genuine intrusion (for definition, see text) without flaring of the teeth. When two central incisors were incorporated in the sectional wire, strong torque forces appeared, especially when the intrusive forces seized more distally. When four or six anterior teeth were pinned in the sectional wire, tooth movement seemed to be under better control. When the six front teeth were incorporated in the sectional wire, the center of resistance (for definition, see text) was located more to the distal side of the canines. It seemed more difficult, however, to define the center of resistance of the four incisors; it was situated approximately distal to the lateral incisors. In some of the intrusive systems, the teeth underwent independent mesial or distal rotations. This was easily observed with the laser measuring techniques used.

  13. Integrating Internet Video Conferencing Techniques and Online Delivery Systems with Hybrid Classes to Enhance Student Interaction and Learning in Accelerated Programs

    Science.gov (United States)

    Beckwith, E. George; Cunniff, Daniel T.

    2009-01-01

    Online course enrollment has increased dramatically over the past few years. The authors cite the reasons for this rapid growth and the opportunities open for enhancing teaching/learning techniques such as video conferencing and hybrid class combinations. The authors outlined an example of an accelerated learning, eight-class session course…

  14. Fabrication of 2×2 Thermo-Optic Switches with Organic-Inorganic Hybrid Materials Prepared by Sol-Gel Technique

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    2×2 Mach-Zehnder interferometric thermo-optic switch was fabricated with organic/inorganic hybrid materials by sol-gel technique and direct UV patterning. The switching time of device was measured to be 4.2 ms and switching power 9.3 mW.

  15. A hybrid stock trading framework integrating technical analysis with machine learning techniques

    Directory of Open Access Journals (Sweden)

    Rajashree Dash

    2016-03-01

    Full Text Available In this paper, a novel decision support system using a computational efficient functional link artificial neural network (CEFLANN and a set of rules is proposed to generate the trading decisions more effectively. Here the problem of stock trading decision prediction is articulated as a classification problem with three class values representing the buy, hold and sell signals. The CEFLANN network used in the decision support system produces a set of continuous trading signals within the range 0–1 by analyzing the nonlinear relationship exists between few popular technical indicators. Further the output trading signals are used to track the trend and to produce the trading decision based on that trend using some trading rules. The novelty of the approach is to engender the profitable stock trading decision points through integration of the learning ability of CEFLANN neural network with the technical analysis rules. For assessing the potential use of the proposed method, the model performance is also compared with some other machine learning techniques such as Support Vector Machine (SVM, Naive Bayesian model, K nearest neighbor model (KNN and Decision Tree (DT model.

  16. Flexible Riser Monitoring Using Hybrid Magnetic/Optical Strain Gage Techniques through RLS Adaptive Filtering

    Directory of Open Access Journals (Sweden)

    Pipa Daniel

    2010-01-01

    Full Text Available Flexible riser is a class of flexible pipes which is used to connect subsea pipelines to floating offshore installations, such as FPSOs (floating production/storage/off-loading unit and SS (semisubmersible platforms, in oil and gas production. Flexible risers are multilayered pipes typically comprising an inner flexible metal carcass surrounded by polymer layers and spiral wound steel ligaments, also referred to as armor wires. Since these armor wires are made of steel, their magnetic properties are sensitive to the stress they are subjected to. By measuring their magnetic properties in a nonintrusive manner, it is possible to compare the stress in the armor wires, thus allowing the identification of damaged ones. However, one encounters several sources of noise when measuring electromagnetic properties contactlessly, such as movement between specimen and probe, and magnetic noise. This paper describes the development of a new technique for automatic monitoring of armor layers of flexible risers. The proposed approach aims to minimize these current uncertainties by combining electromagnetic measurements with optical strain gage data through a recursive least squares (RLSs adaptive filter.

  17. Heart dose reduction in breast cancer treatment with simultaneous integrated boost. Comparison of treatment planning and dosimetry for a novel hybrid technique and 3D-CRT

    Energy Technology Data Exchange (ETDEWEB)

    Joest, Vincent; Kretschmer, Matthias; Sabatino, Marcello; Wuerschmidt, Florian; Dahle, Joerg; Lorenzen, Joern [Radiological Alliance, Hamburg (Germany); Ueberle, Friedrich [University of Applied Sciences, Faculty Life Sciences, Hamburg (Germany)

    2015-09-15

    The present study compares in silico treatment plans of clinically established three-dimensional conformal radiotherapy (3D-CRT) with a hybrid technique consisting of intensity-modulated radiotherapy (IMRT) and volumetric modulated arc radiotherapy (VMAT) during normally fractionated radiation of mammary carcinomas with simultaneous integrated boost on the basis of dose-volume histogram (DVH) parameters. Radiation treatment planning was performed with a hybrid and a 3D-CRT treatment plan for 20 patients. Hybrid plans were implemented with two tangential IMRT fields and a VMAT field in the angular range of the tangents. Verification of the plan was performed with a manufacturer-independent measurement system consisting of a detector array and rotation unit. The mean values of the heart dose for the entire patient collective were 3.6 ± 2.5 Gy for 3D-CRT and 2.9 ± 2.1 Gy for the hybrid technique (p < 0.01). For the left side (n = 10), the mean values for the left anterior descending artery were 21.8 ± 7.4 Gy for 3D-CRT and 17.6 ± 7.4 Gy for the hybrid technique (p < 0.01). The mean values of the ipsilateral lung were 11.9 ± 1.6 Gy for 3D-CRT and 10.5 ± 1.3 Gy for the hybrid technique (p < 0.01). Calculated dose distributions in the hybrid arm were in good accordance with measured dose (on average 95.6 ± 0.5 % for γ < 1 and 3 %/3 mm). The difference of the mean treatment time per fraction was 7 s in favor of 3D-CRT. Compared with the established 3D-CRT technique, the hybrid technique allows for a decrease in dose, particularly of the mean heart and lung dose with comparable target volume acquisition and without disadvantageous low-dose load of contralateral structures. Uncomplicated implementation of the hybrid technique was demonstrated in this context. The hybrid technique combines the advantages of tangential IMRT with the superior sparing of organs at risk by VMAT. (orig.) [German] Die vorliegende Studie vergleicht ''in silico

  18. Chitosan-pectin hybrid nanoparticles prepared by coating and blending techniques.

    Science.gov (United States)

    Rampino, A; Borgogna, M; Bellich, B; Blasi, P; Virgilio, F; Cesàro, A

    2016-03-10

    The preparation of chitosan nanoparticles in combination with pectins, as additional mucoadhesive biopolymers, was investigated. Pectins from apple and from citrus fruit were considered; polygalacturonic acid was taken as a reference. Tripolyphosphate was used as an anionic cross-linker. Two different techniques were compared, namely the coating and the blending. Coated nanoparticles (NPs) in the ratio pectin:NPs from 2:1 to 5:1 evidenced that the size of NPs increased as the amount of pectin (both from apple and citrus fruit) was increased. In particular, for NPs coated with pectin from citrus fruit the size ranges from 200 to 260nm; while for NPs coated with pectin from apple the size ranges from 330 to 450nm. A minimum value of Z-potential around -35mV was obtained for the ratio pectin:NPs 4:1, while further addition of pectin did not decrease the Z-potential. Also blended NPs showed a dependence of the size on the ratio of the components: for a given ratio pectin:tripolyphosphate the size increases as the fraction of chitosan increases; for a low ratio chitosan:pectin a high amount of tripolyphosphate was needed to obtain a compact structure. The effect of the additional presence of loaded proteins in chitosan-pectin nanoparticles was also investigated, since proteins contribute to alter the electrostatic interactions among charged species. FT-IR and DSC characterization are presented to confirm the interactions between biopolymers. Finally, the biocompatibility of the used materials was assessed by the chorioallantoic membrane assay, confirming the safety of the materials.

  19. Hybrid approach combining multiple characterization techniques and simulations for microstructural analysis of proton exchange membrane fuel cell electrodes

    Science.gov (United States)

    Cetinbas, Firat C.; Ahluwalia, Rajesh K.; Kariuki, Nancy; De Andrade, Vincent; Fongalland, Dash; Smith, Linda; Sharman, Jonathan; Ferreira, Paulo; Rasouli, Somaye; Myers, Deborah J.

    2017-03-01

    The cost and performance of proton exchange membrane fuel cells strongly depend on the cathode electrode due to usage of expensive platinum (Pt) group metal catalyst and sluggish reaction kinetics. Development of low Pt content high performance cathodes requires comprehensive understanding of the electrode microstructure. In this study, a new approach is presented to characterize the detailed cathode electrode microstructure from nm to μm length scales by combining information from different experimental techniques. In this context, nano-scale X-ray computed tomography (nano-CT) is performed to extract the secondary pore space of the electrode. Transmission electron microscopy (TEM) is employed to determine primary C particle and Pt particle size distributions. X-ray scattering, with its ability to provide size distributions of orders of magnitude more particles than TEM, is used to confirm the TEM-determined size distributions. The number of primary pores that cannot be resolved by nano-CT is approximated using mercury intrusion porosimetry. An algorithm is developed to incorporate all these experimental data in one geometric representation. Upon validation of pore size distribution against gas adsorption and mercury intrusion porosimetry data, reconstructed ionomer size distribution is reported. In addition, transport related characteristics and effective properties are computed by performing simulations on the hybrid microstructure.

  20. Recovery and reuse of hexavalent chromium from aqueous solutions by a hybrid technique of electrodialysis and ion exchange

    Energy Technology Data Exchange (ETDEWEB)

    Gayathri, R. [Sengunthar Engineering College, Tiruchengode (India). Dept. of Civil Engineering], e-mail: gay3civil@gmail.com; Senthil Kumar, P. [SSN College of Engineering, Chennai (India). Dept. of Chemical Engineering], E-mail: senthilkumarp@ssn.edu.in

    2010-01-15

    The chrome plating industry is one of the highly polluting industries whose effluent mainly consists of chromium(VI). This compound is highly toxic to aquatic life and human health. The rinse water constituents reflect the chrome plating bath characteristics; generally dead tank wash water contains about 1% of the plating bath concentration. Other metals and metal compounds usually considered as toxic can be precipitated out by suitably adjusting the pH of the wastewaters. However, Cr(VI) is soluble in almost all pH ranges and therefore an efficient treatment is required for the removal and recovery of chromium, and also for the reuse of wastewaters. The present study aims to recover the chromium by a hybrid technique of electrodialysis and ion exchange for the removal and concentration of chromate ions from the effluent. The different modes of operation like batch recirculation process, batch recirculation process with continuous dipping and continuous process were carried out to remove and recover the chromium from the effluent and the percentage reductions of chromium were found to be 98.69%, 99.18% and 100%, respectively. (author)

  1. A hybrid experimental-numerical technique for determining 3D velocity fields from planar 2D PIV data

    Science.gov (United States)

    Eden, A.; Sigurdson, M.; Mezić, I.; Meinhart, C. D.

    2016-09-01

    Knowledge of 3D, three component velocity fields is central to the understanding and development of effective microfluidic devices for lab-on-chip mixing applications. In this paper we present a hybrid experimental-numerical method for the generation of 3D flow information from 2D particle image velocimetry (PIV) experimental data and finite element simulations of an alternating current electrothermal (ACET) micromixer. A numerical least-squares optimization algorithm is applied to a theory-based 3D multiphysics simulation in conjunction with 2D PIV data to generate an improved estimation of the steady state velocity field. This 3D velocity field can be used to assess mixing phenomena more accurately than would be possible through simulation alone. Our technique can also be used to estimate uncertain quantities in experimental situations by fitting the gathered field data to a simulated physical model. The optimization algorithm reduced the root-mean-squared difference between the experimental and simulated velocity fields in the target region by more than a factor of 4, resulting in an average error less than 12% of the average velocity magnitude.

  2. Degradation of Tectilon Yellow 2G by hybrid technique: combination of sonolysis and biodegradation using mutant Pseudomonas putida.

    Science.gov (United States)

    Srinivasan, Raman; Kathiravan, Mathur Nadarajan; Gopinath, Kannappan Panchamoorthy

    2011-02-01

    Degradation of Tectilon Yellow 2G (TY2G), an azo dye has been studied by hybrid technique involving pretreatment by sonochemical method and further biological treatment by Pseudomonas putida mutant. Pretreatment experiments were carried out by sonolysis of the dye solution at different concentrations (100-1000 mg/L). Wild type Gram-negative P. putida species isolated from the textile effluent contaminated soil, which was found to be effective towards dye degradation, has been acclimatized so as to consume TY2G as the sole source of nutrition. Mutant strain was obtained from the acclimatized species by random mutagenesis using the chemical mutagen ethidium bromide for various time intervals (6-30 min). The optimum mutagenesis exposure time for obtaining the most efficient species for dye degradation was found to be 18 min. An efficient mutant strain P. putida ACT 1 has been isolated and was used for growth experiments. The mutant strain showed a better growth compared to the wild strain. The substrate utilization kinetics has been modeled using Monod and Haldane model equations of which the Haldane model provided a better fit. The enzyme kinetics of the mutant and wild species was obtained using Michaelis-Menten equation. The mutated species showed better enzyme kinetics towards the degradation of TY2G.

  3. Hybrid evolutionary techniques in feed forward neural network with distributed error for classification of handwritten Hindi `SWARS'

    Science.gov (United States)

    Kumar, Somesh; Pratap Singh, Manu; Goel, Rajkumar; Lavania, Rajesh

    2013-12-01

    In this work, the performance of feedforward neural network with a descent gradient of distributed error and the genetic algorithm (GA) is evaluated for the recognition of handwritten 'SWARS' of Hindi curve script. The performance index for the feedforward multilayer neural networks is considered here with distributed instantaneous unknown error i.e. different error for different layers. The objective of the GA is to make the search process more efficient to determine the optimal weight vectors from the population. The GA is applied with the distributed error. The fitness function of the GA is considered as the mean of square distributed error that is different for each layer. Hence the convergence is obtained only when the minimum of different errors is determined. It has been analysed that the proposed method of a descent gradient of distributed error with the GA known as hybrid distributed evolutionary technique for the multilayer feed forward neural performs better in terms of accuracy, epochs and the number of optimal solutions for the given training and test pattern sets of the pattern recognition problem.

  4. Heat Treatment Parameters to Optimize Friction and Wear behavior of Novel Hybrid Aluminium Composites Using Taguchi Technique

    Directory of Open Access Journals (Sweden)

    V.C.Uvaraja

    2014-05-01

    Full Text Available In the present study, an Al 7075 alloy is used as the matrix and varying weight percentage of Silicon Carbide (SiC and constant weight percentage of Boron Carbide (B4C as the reinforcing material. The composite is produced using stir casting technique. The composite thus formed is termed as hybrid composite. The samples are prepared for heat treatment process by subjecting to solutionizing temperature of 530o C for 1 hr followed by quenching in water. Further the specimens are subjected to artificial aging for durations of 4, 6 and 8 hr at a temperature of 175°C. The mechanical and tribological properties of composites before and after heat treatment are examined by Vickers hardness test machine and pin-on-disc test machine respectively. The wear rate and friction co-efficient of heat treatment parameters are evaluated based on Taguchi technique. The analysis is further extended to the optimization of test parameters using Design of Experiment (DoE based on L9 orthogonal array. The developed Analysis of Variance (ANOVA and the regression equations is obtained through MINITAB R16 are used to investigate the influence of parameters like sliding speed, applied load, sliding time, and percentage of reinforcement on the dry sliding wear and friction co-efficient of the composites. The wear surface morphology and wear mechanism of the pins are investigated using Scanning Electron Microscope (SEM and are correlated them with wear test results. Finally, confirmation tests are carried out to verify the experimental results.

  5. The application of fluorescence in situ hybridization (FISH technique for studying the microbial communities in intestinal tissues of white shrimp (Penaeus vannamei

    Directory of Open Access Journals (Sweden)

    Supamattaya, K.

    2005-02-01

    Full Text Available Fluorescence in situ hybridization technique is very useful for the evaluation of microbial communities in various environments. It is possible to apply this technique to study the intestinal microflora in white shrimp (Penaeus vannamei. Different fixatives and storage temperature were tested in this technique. It was found that fixation with 10% buffered formalin for 12 hours and changed to 70% ethanol shown positive results when compared to the fixation with Davidson's fixative or RF fixative. The best signaling was obtainedfrom the samples which were stored in -20ºC. By using the DNA probe targeted to the Eubacteria domain (EUB338 probe, 5′-GCT GCC TCC CGT AGG AGT-3′ labeled with fluorescein as a hybridizing probe, it was found that most intestinal microflora were aggregated with the intestinal contents, or dispersed in the lumen. There was not evidence of the attachment of the microflora with the intestinal epithelium in this study.

  6. Influence of the polymer amount on bioactivity and biocompatibility of SiO{sub 2}/PEG hybrid materials synthesized by sol–gel technique

    Energy Technology Data Exchange (ETDEWEB)

    Catauro, M., E-mail: michelina.catauro@unina2.it [Department of Industrial and Information Engineering, Second University of Naples, Via Roma 29, 81031 Aversa (Italy); Bollino, F.; Papale, F. [Department of Industrial and Information Engineering, Second University of Naples, Via Roma 29, 81031 Aversa (Italy); Gallicchio, M.; Pacifico, S. [Department of Environmental Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, Via Vivaldi 43, 81100 Caserta (Italy)

    2015-03-01

    SiO{sub 2}/PEG organic–inorganic hybrid materials, which differ in polyethylene glycol (PEG) content, were synthesized by sol–gel technique and the characterization of their structure and biological properties was carried out in order to evaluate the possible use in biomedical field. FT-IR spectroscopy detected that the two components of the hybrids (SiO{sub 2} and PEG) are linked by hydrogen bonds between the Si–OH groups of the inorganic phase and the terminal alcoholic groups and/or the ethereal oxygen atoms in the repeating units of polymer. X-ray diffraction analysis ascertained the amorphous nature of the gels and the observation of their morphology by SEM microscopy confirmed that the interpenetration of the two phases (organic and inorganic) occurs on nanometric scale. The biological characterization was carried out as a function of the polymer amount to study its influence on material behavior. The results showed that the synthesized materials were bioactive and biocompatible. The formation of a hydroxyapatite layer, indeed, was observed on their surface by SEM/EDX analysis after soaking in simulated body fluid. Moreover, the biocompatibility of SiO{sub 2}/PEG hybrids was assessed performing MTT and SRB cytotoxicity tests on fibroblast cell NIH 3T3 after 24 and 48 h of exposure, as well as Trypan Blue dye exclusion test. The response to the presence of the investigated materials was positive. The cell growth and proliferation showed dependence on polymer amount and time of exposure to the material extracts. Therefore, the obtained results are encouraging for the use of the obtained hybrids in dental or orthopedic applications. - Highlights: • SiO{sub 2}/PEG hybrid biomaterials synthesized by sol–gel method at various PEG percentages • Chemical and morphological characterization of hybrid materials • Chemical interactions between inorganic and organic components • Biological characterizations with MTT and SRB cytotoxicity tests

  7. A fast and robust new pore-network extraction method based on hybrid median axis and maximal inscribed ball techniques

    Science.gov (United States)

    Timofey, Sizonenko; Karsanina, Marina; Byuk, Irina; Gerke, Kirill

    2016-04-01

    To characterize pore structure relevant to single and multi-phase flow modelling it is of special interest to extract topology of the pore space. This is usually achieved using so-called pore-network models. Such models are useful not only to characterize pore space and pore size distributions, but also provide means to simulate flow and transport with very limited computational resources compared to other pore-scale modelling techniques. The main drawback of the pore-network approach is that they have first to simplify the pore space geometry. This crucial step is both time consuming and prone to numerous errors. Two most popular methods based on median axis or inscribed maximal balls have their own strong sides and disadvantages. To address aforementioned problems related to pore-network extraction here we propose a novel method utilizing the advantages of both popular approaches. Combining two algorithms resulted in much faster and robust extraction methodology. Moreover, we have found that accurate topology representation requires extension of the conventional pore-body and pore-throat classification. We test our new methodology using pore structures with "analytical solutions" such as different sphere packs. In addition, we rigorously compare it against inscribed maximal balls methodology's results using numerous 3D images of sandstone and carbonate rocks, soils and some other porous materials. Another verification includes permeability calculations which are also compared both against lab data and voxel based pore-scale modelling simulations. This work was partially supported by RFBR grant 15-34-20989 (X-ray tomography and image fusion) and RSF grant 14-17-00658 (image segmentation and pore-scale modelling).

  8. Hybrid-SAR Technique: Joint Analysis Using Phase-Based and Amplitude-Based Methods for the Xishancun Giant Landslide Monitoring

    Directory of Open Access Journals (Sweden)

    Tengteng Qu

    2016-10-01

    Full Text Available Early detection and early warning are of great importance in giant landslide monitoring because of the unexpectedness and concealed nature of large-scale landslides. In China, the western mountainous areas are prone to landslides and feature many giant complex landslides, especially following the Wenchuan Earthquake in 2008. This work concentrates on a new technique, known as the “hybrid-SAR technique”, that combines both phase-based and amplitude-based methods to detect and monitor large-scale landslides in Li County, Sichuan Province, southwestern China. This work aims to develop a robust methodological approach to promptly identify diverse landslides with different deformation magnitudes, sliding modes and slope geometries, even when the available satellite data are limited. The phase-based and amplitude-based techniques are used to obtain the landslide displacements from six TerraSAR-X Stripmap descending scenes acquired from November 2014 to March 2015. Furthermore, the application circumstances and influence factors of hybrid-SAR are evaluated according to four aspects: (1 quality of terrain visibility to the radar sensor; (2 landslide deformation magnitude and different sliding mode; (3 impact of dense vegetation cover; and (4 sliding direction sensitivity. The results achieved from hybrid-SAR are consistent with in situ measurements. This new hybrid-SAR technique for complex giant landslide research successfully identified representative movement areas, e.g., an extremely slow earthflow and a creeping region with a displacement rate of 1 cm per month and a typical rotational slide with a displacement rate of 2–3 cm per month downwards and towards the riverbank. Hybrid-SAR allows for a comprehensive and preliminary identification of areas with significant movement and provides reliable data support for the forecasting and monitoring of landslides.

  9. Brain image segmentation method with hybrid model based on FESS%基于FESS的混合模型脑图像分割方法

    Institute of Scientific and Technical Information of China (English)

    连远锋; 赵剡; 何晖光; 陈雪姣

    2013-01-01

    提出一种基于FESS的混合模型脑图像分割方法.其特点在于生成模型与判别模型得到了有效结合.生成模型通过条件随机场融合体素点的灰度信息、形状信息以及区域相邻关系,实现对脑子结构外观特征的描述.在此基础上,利用生成模型将训练样本映射到FESS特征空间;判别模型中采用LS-SVM分类器并将数据场应用于混合分割模型的训练过程中,降低了判别模型由于训练数据不平衡而引起的性能波动并提高其泛化能力.实验结果表明,与若干前沿的脑图像分割方法相比,该方法具有更好的分割质量和性能.%This paper presents a new brain image segmentation method based on free energy score space FESS),which combines the advantages of both generative model and discriminative model.Through conditional random field,the generative model fuses the grey scale information,shape information and spatial neighborhood relation of the volume pixels ; and the appearance feature description of subcortical structure is realized.Based on the above,the generative model is used to map the training samples to FESS feature space.Furthermore;in the discriminative model,the LS-SVM classifier is used and the data field is applied in the training process of the mixed segmentation model,which reduces the performance fluctuation of the discriminative model induced by the imbalanced training data sets and effectively improves the generalization capability.Experimental results show that the proposed model possesses better segmentation quality and performance compared with several other state-of-the-art brain image segmentation approaches.

  10. Assessment of fusion facility dose rate map using mesh adaptivity enhancements of hybrid Monte Carlo/deterministic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, Ahmad M., E-mail: ibrahimam@ornl.gov [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Wilson, Paul P. [University of Wisconsin-Madison, 1500 Engineering Dr., Madison, WI 53706 (United States); Sawan, Mohamed E., E-mail: sawan@engr.wisc.edu [University of Wisconsin-Madison, 1500 Engineering Dr., Madison, WI 53706 (United States); Mosher, Scott W.; Peplow, Douglas E.; Grove, Robert E. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States)

    2014-10-15

    Highlights: •Calculate the prompt dose rate everywhere throughout the entire fusion energy facility. •Utilize FW-CADIS to accurately perform difficult neutronics calculations for fusion energy systems. •Develop three mesh adaptivity algorithms to enhance FW-CADIS efficiency in fusion-neutronics calculations. -- Abstract: Three mesh adaptivity algorithms were developed to facilitate and expedite the use of the CADIS and FW-CADIS hybrid Monte Carlo/deterministic techniques in accurate full-scale neutronics simulations of fusion energy systems with immense sizes and complicated geometries. First, a macromaterial approach enhances the fidelity of the deterministic models without changing the mesh. Second, a deterministic mesh refinement algorithm generates meshes that capture as much geometric detail as possible without exceeding a specified maximum number of mesh elements. Finally, a weight window coarsening algorithm decouples the weight window mesh and energy bins from the mesh and energy group structure of the deterministic calculations in order to remove the memory constraint of the weight window map from the deterministic mesh resolution. The three algorithms were used to enhance an FW-CADIS calculation of the prompt dose rate throughout the ITER experimental facility and resulted in a 23.3% increase in the number of mesh tally elements in which the dose rates were calculated in a 10-day Monte Carlo calculation. Additionally, because of the significant increase in the efficiency of FW-CADIS simulations, the three algorithms enabled this difficult calculation to be accurately solved on a regular computer cluster, eliminating the need for a world-class super computer.

  11. Skin Images Segmentation

    Directory of Open Access Journals (Sweden)

    Ali E. Zaart

    2010-01-01

    Full Text Available Problem statement: Image segmentation is a fundamental step in many applications of image processing. Skin cancer has been the most common of all new cancers detected each year. At early stage detection of skin cancer, simple and economic treatment can cure it mostly. An accurate segmentation of skin images can help the diagnosis to define well the region of the cancer. The principal approach of segmentation is based on thresholding (classification that is lied to the problem of the thresholds estimation. Approach: The objective of this study is to develop a method to segment the skin images based on a mixture of Beta distributions. We assume that the data in skin images can be modeled by a mixture of Beta distributions. We used an unsupervised learning technique with Beta distribution to estimate the statistical parameters of the data in skin image and then estimate the thresholds for segmentation. Results: The proposed method of skin images segmentation was implemented and tested on different skin images. We obtained very good results in comparing with the same techniques with Gamma distribution. Conclusion: The experiment showed that the proposed method obtained very good results but it requires more testing on different types of skin images.

  12. Segmentation and additive approach: A reliable technique to study noncovalent interactions of large molecules at the surface of single-wall carbon nanotubes.

    Science.gov (United States)

    Torres, Ana M; Scheiner, Steve; Roy, Ajit K; Garay-Tapia, Andrés M; Bustamante, John; Kar, Tapas

    2016-08-05

    This investigation explores a new protocol, named Segmentation and Additive approach (SAA), to study exohedral noncovalent functionalization of single-walled carbon nanotubes with large molecules, such as polymers and biomolecules, by segmenting the entire system into smaller units to reduce computational cost. A key criterion of the segmentation process is the preservation of the molecular structure responsible for stabilization of the entire system in smaller segments. Noncovalent interaction of linoleic acid (LA, C18 H32 O2 ), a fatty acid, at the surface of a (10,0) zigzag nanotube is considered for test purposes. Three smaller segmented models have been created from the full (10,0)-LA system and interaction energies were calculated for these models and compared with the full system at different levels of theory, namely ωB97XD, LDA. The success of this SAA is confirmed as the sum of the interaction energies is in very good agreement with the total interaction energy. Besides reducing computational cost, another merit of SAA is an estimation of the contributions from different sections of the large system to the total interaction energy which can be studied in-depth using a higher level of theory to estimate several properties of each segment. On the negative side, bulk properties, such as HOMO-LUMO (highest occupied molecular orbital - lowest occupied molecular orbital) gap, of the entire system cannot be estimated by adding results from segment models. © 2016 Wiley Periodicals, Inc.

  13. Image Segmentation for Food Quality Evaluation Using Computer Vision System

    Directory of Open Access Journals (Sweden)

    Nandhini. P

    2014-02-01

    Full Text Available Quality evaluation is an important factor in food processing industries using the computer vision system where human inspection systems provide high variability. In many countries food processing industries aims at producing defect free food materials to the consumers. Human evaluation techniques suffer from high labour costs, inconsistency and variability. Thus this paper provides various steps for identifying defects in the food material using the computer vision systems. Various steps in computer vision system are image acquisition, Preprocessing, image segmentation, feature identification and classification. The proposed framework provides the comparison of various filters where the hybrid median filter was selected as the filter with the high PSNR value and is used in preprocessing. Image segmentation techniques such as Colour based binary Image segmentation, Particle swarm optimization are compared and image segmentation parameters such as accuracy, sensitivity , specificity are calculated and found that colour based binary image segmentation is well suited for food quality evaluation. Finally this paper provides an efficient method for identifying the defected parts in food materials.

  14. Analysis, control and optimal operations in hybrid power systems advanced techniques and applications for linear and nonlinear systems

    CERN Document Server

    Bizon, Nicu; Mahdavi Tabatabaei, Naser

    2014-01-01

    This book explains and analyzes the dynamic performance of linear and nonlinear systems, particularly for Power Systems including Hybrid Power Sources. Offers a detailed description of system stability using state space energy conservation principle, and more.

  15. Robust segmentation and retrieval of environmental sounds

    Science.gov (United States)

    Wichern, Gordon

    The proliferation of mobile computing has provided much of the world with the ability to record any sound of interest, or possibly every sound heard in a lifetime. The technology to continuously record the auditory world has applications in surveillance, biological monitoring of non-human animal sounds, and urban planning. Unfortunately, the ability to record anything has led to an audio data deluge, where there are more recordings than time to listen. Thus, access to these archives depends on efficient techniques for segmentation (determining where sound events begin and end), indexing (storing sufficient information with each event to distinguish it from other events), and retrieval (searching for and finding desired events). While many such techniques have been developed for speech and music sounds, the environmental and natural sounds that compose the majority of our aural world are often overlooked. The process of analyzing audio signals typically begins with the process of acoustic feature extraction where a frame of raw audio (e.g., 50 milliseconds) is converted into a feature vector summarizing the audio content. In this dissertation, a dynamic Bayesian network (DBN) is used to monitor changes in acoustic features in order to determine the segmentation of continuously recorded audio signals. Experiments demonstrate effective segmentation performance on test sets of environmental sounds recorded in both indoor and outdoor environments. Once segmented, every sound event is indexed with a probabilistic model, summarizing the evolution of acoustic features over the course of the event. Indexed sound events are then retrieved from the database using different query modalities. Two important query types are sound queries (query-by-example) and semantic queries (query-by-text). By treating each sound event and semantic concept in the database as a node in an undirected graph, a hybrid (content/semantic) network structure is developed. This hybrid network can

  16. TiO{sub 2}/PCL hybrid materials synthesized via sol–gel technique for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Catauro, M., E-mail: michelina.catauro@unina2.it [Department of Industrial and Information Engineering, Second University of Naples, Via Roma 29, 81031 Aversa (Italy); Bollino, F.; Papale, F. [Department of Industrial and Information Engineering, Second University of Naples, Via Roma 29, 81031 Aversa (Italy); Marciano, S.; Pacifico, S. [Department Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, Via Vivaldi 43, 81100 Caserta (Italy)

    2015-02-01

    The aim of the present work has been the synthesis of organic/inorganic hybrid materials based on titanium dioxide and poly(ε-caprolactone) (PCL) to be used in the biomedical field. Several materials have been synthesized using sol–gel methods by adding different amounts of polymer to the inorganic sol. The obtained gels have been characterized using Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) and atomic force microscopy (AFM). The FT-IR data allowed us to hypothesize that the structure formed was that of an interpenetrating network, realized by hydrogen bonds between Ti-OH groups in the sol–gel intermediate species and carbonyl groups in the polymer repeating units. SEM and AFM analyses highlighted that the obtained materials were nanostructurated hybrids. To evaluate the biological properties of the hybrids, their bioactivity and cytotoxicity were investigated as a function of the PCL amount. The bioactivity of the synthesized systems was proven by the formation of a hydroxyapatite layer on the surface of samples soaked in a fluid simulating human blood plasma (SBF). MTT cytotoxicity tests and Trypan Blue dye exclusion tests were carried out exposing NIH-3T3 mouse embryonic fibroblasts for 24 and 48 h to extracts from the investigated hybrid materials. The results showed that all the hybrids had a non-cytotoxic effect on target cells. - Highlights: • TiO{sub 2}/PCL hybrids were obtained by the sol–gel process for biomedical applications. • Synthesized materials were found to be first-class hybrid nanocomposites. • Hybrids appear to be bioactive, a fundamental characteristic for osseointegration. • MTT and Trypan Blue viability test show that the materials are biocompatible. • The organic phase is able to modulate the biocompatibility of the materials.

  17. Investigation of kinetics and thermodynamics of DNA hybridization by means of 2-D fluorescence spectroscopy and soft/hard modeling techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ebrahimi, Sara; Kompany-Zareh, Mohsen, E-mail: kmpz@dr.com

    2016-02-04

    Reversible hybridization reaction plays a key role in fundamental biological processes, in many laboratory techniques, and also in DNA based sensing devices. Comprehensive investigation of this process is, therefore, essential for the development of more sophisticated applications. Kinetics and thermodynamics of the hybridization reaction, as a second order process, are systematically investigated with the aid of the soft and hard chemometric methods. Labeling two complementary 21 mer DNA single strands with FAM and Texas red fluorophores, enabled recording of the florescence excitation−emission matrices during the experiments which led to three-way data sets. The presence of fluorescence resonance energy transfer in excitation and emission modes and the closure in concentration mode, made the three-way data arrays rank deficient. To acquire primary chemical information, restricted Tucker3 as a soft method was employed. Herein a model-based method, hard restricted trilinear decomposition, is introduced for in depth analysis of rank deficient three-way data sets. By employing proposed hard method, the nonlinear model parameters as well as the correct profiles could be estimated. In addition, a simple constraint is presented to extract chemically reasonable output profiles regarding the core elements of restricted Tucker3 model. - Highlights: • Hard restricted trilinear decomposition (HrTD) was introduced for model-based analysis of three-way rank deficient data. • DNA hybridization was investigated by two-dimensional fluorescence spectroscopy and soft/hard multi-way techniques. • Restricted Tucker3 analysis enabled accurate estimation of pure FRET profiles in the hybridized form. • HrTD was successfully employed to estimate kinetic and equilibrium parameters of DNA hybridization system. • The performance of the proposed methods in response to different physical stimuli was successfully evaluated.

  18. Detection of chromosomal abnormalities by comparative genomic hybridization.

    Science.gov (United States)

    Lapierre, Jean-Michel; Tachdjian, Gérard

    2005-04-01

    Comparative genomic hybridization (CGH) is a modified in-situ hybridization technique. In this type of analysis, two differentially labeled genomic DNAs (study and reference) are cohybridized to normal metaphase spreads or to microarray. Chromosomal locations of copy number changes in the DNA segments of the study genome are revealed by a variable fluorescence intensity ratio along each target chromosome. Thus, CGH allows detection and mapping of DNA sequence copy differences between two genomes in a single experiment. Since its development, comparative genomic hybridization has been applied mostly as a research tool in the field of cancer cytogenetics to identify genetic changes in many previously unknown regions. It is also a powerful tool for detection and identification of unbalanced chromosomal abnormalities in prenatal, postnatal and preimplantation diagnostics. The development of comparative genomic hybridization and increase in resolution analysis by using the microarray-based technique offer new information on chromosomal pathologies and thus better management of patients.

  19. New Technique for Automatic Segmentation of Blood Vessels in CT Scan Images of Liver Based on Optimized Fuzzy C-Means Method

    Directory of Open Access Journals (Sweden)

    Katayoon Ahmadi

    2016-01-01

    Full Text Available Automatic segmentation of medical CT scan images is one of the most challenging fields in digital image processing. The goal of this paper is to discuss the automatic segmentation of CT scan images to detect and separate vessels in the liver. The segmentation of liver vessels is very important in the liver surgery planning and identifying the structure of vessels and their relationship to tumors. Fuzzy C-means (FCM method has already been proposed for segmentation of liver vessels. Due to classical optimization process, this method suffers lack of sensitivity to the initial values of ​​class centers and segmentation of local minima. In this article, a method based on FCM in conjunction with genetic algorithms (GA is applied for segmentation of liver’s blood vessels. This method was simulated and validated using 20 CT scan images of the liver. The results showed that the accuracy, sensitivity, specificity, and CPU time of new method in comparison with FCM algorithm reaching up to 91%, 83.62, 94.11%, and 27.17 were achieved, respectively. Moreover, selection of optimal and robust parameters in the initial step led to rapid convergence of the proposed method. The outcome of this research assists medical teams in estimating disease progress and selecting proper treatments.

  20. Coupling physical chemical techniques with hydrotalcite-like compounds to exploit their structural features and new multifunctional hybrids with luminescent properties.

    Science.gov (United States)

    Costantino, Umberto; Costantino, Ferdinando; Elisei, Fausto; Latterini, Loredana; Nocchetti, Morena

    2013-08-28

    Hydrotalcite-like compounds (HTlc), belonging to the large class of Layered Double Hydroxides (LDH), have excited wide interest owing to the incredible number of their potential and achieved applications in physical, chemical and bio-chemical fields. This perspective review deals with recent advances in the application of physical-chemical techniques for the study of HTlc structure and for the design and synthesis, using intercalation chemistry routes, of new hybrid materials. Firstly, a rapid survey on the most common synthetic strategies for the attainment of HTlc with different crystallinity degree and crystal size and for their modification to obtain hybrids has been made, and the use of coupled techniques (XRPD, luminescence, Solid State MAS NMR and Molecular Dynamics) to gain structural information is reported. Then, the design, synthesis and photophysical characterization of azoic dyes-intercalated and co-intercalated HTlc hybrid materials are described. Hybrids constituted of ZnAl-HTlc, co-intercalated with stearate anions and methyl orange or methyl yellow dyes, have been used as nanofillers of hydrophobic polymers. The polymeric nano-composites obtained have been characterized by means of XRPD patterns, Thermo-Gravimetric Analysis and Confocal Fluorescence Microscopy. This latter technique has been found to be an excellent, complementary and non-invasive tool to probe the dispersion degree of the fluorescent fillers into the polymeric matrices and their stability in the compounding process. Finally, the synthesis and spectroscopic characterization of nanoparticle (NP) decorated HTlc for advanced antimicrobial and photo-catalytic applications are also reported. The review terminates with a concluding short note and future trends.

  1. A Novel Hybrid Ultramicrotomy/FIB-SEM Technique: Preparation of Serial Electron-Transparent Thin Sections of a Hayabusa Grain

    Science.gov (United States)

    Berger, Eve L.; Keller, Lindsay P.

    2014-01-01

    The Japanese space agency's (JAXA) Hayabusa mission returned the first particulate samples (typically SEM). Using a diamond trim knife, the epoxy surrounding the grain is removed on 3 sides (to within a few microns of the grain); the depth of material removed extends well below the bottom of the particle. The sample is attached to an SEM pin mount, the epoxy coated with conductive paint, and the entire assembly coated with approx. 40nm of carbon to eliminate sample charging during FIB work. A protective carbon cap is placed according to the plan for the 15 FIB sections. The central 'spine' of the cap runs perpendicular to the front of the sample, and the 'ribs' protruding from either side run parallel. Each rib indicates the location of a planned FIB section, and the spine contains the final two planned sections. We use a cap with a 4 micron-wide spine and 2micron-wide ribs that have ?3.5 micron of space between them (narrower cuts result in too much re-deposition of material inside the trenches). Using a 30kV, 3nA ion-beam we expose the front surface of the grain and commence milling trenches between sections. Rather than using the typical C-cut to prepare the sample for lift-out, an L-cut is used instead, leaving the sample connected by an interior tab. tab. Sections are lifted out, attached to TEM grids and thinned to electron transparency. TEM analyses show that our hybrid technique preserves both interior and edge features, including surface modifications from exposure to the space environment, such as damaged rims that form in response to solar wind implantation effects and adhering grains. In addition, the FIB sections provide larger areas that are free of fractures and chatter effects in comparison to the microtome thin sections, thus enabling more accurate measurements of solar flare particle track densities that are used to determine the surface exposure age of the particles.

  2. 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…

  3. Sagittal Plane Correction Using the Lateral Transpsoas Approach: A Biomechanical Study on the Effect of Cage Angle and Surgical Technique on Segmental Lordosis.

    Science.gov (United States)

    Melikian, Rojeh; Yoon, Sangwook Tim; Kim, Jin Young; Park, Kun Young; Yoon, Caroline; Hutton, William

    2016-09-01

    Cadaveric biomechanical study. To determine the degree of segmental correction that can be achieved through lateral transpsoas approach by varying cage angle and adding anterior longitudinal ligament (ALL) release and posterior element resection. Lordotic cage insertion through the lateral transpsoas approach is being used increasingly for restoration of sagittal alignment. However, the degree of correction achieved by varying cage angle and ALL release and posterior element resection is not well defined. Thirteen lumbar motion segments between L1 and L5 were dissected into single motion segments. Segmental angles and disk heights were measured under both 50 N and 500 N compressive loads under the following conditions: intact specimen, discectomy (collapsed disk simulation), insertion of parallel cage, 10° cage, 30° cage with ALL release, 30° cage with ALL release and spinous process (SP) resection, 30° cage with ALL release, SP resection, facetectomy, and compression with pedicle screws. Segmental lordosis was not increased by either parallel or 10° cages as compared with intact disks, and contributed small amounts of lordosis when compared with the collapsed disk condition. Placement of 30° cages with ALL release increased segmental lordosis by 10.5°. Adding SP resection increased lordosis to 12.4°. Facetectomy and compression with pedicle screws further increased lordosis to approximately 26°. No interventions resulted in a decrease in either anterior or posterior disk height. Insertion of a parallel or 10° cage has little effect on lordosis. A 30° cage insertion with ALL release resulted in a modest increase in lordosis (10.5°). The addition of SP resection and facetectomy was needed to obtain a larger amount of correction (26°). None of the cages, including the 30° lordotic cage, caused a decrease in posterior disk height suggesting hyperlordotic cages do not cause foraminal stenosis. N/A.

  4. COED Transactions, Vol. IX, No. 3, March 1977. Evaluation of a Complex Variable Using Analog/Hybrid Computation Techniques.

    Science.gov (United States)

    Marcovitz, Alan B., Ed.

    Described is the use of an analog/hybrid computer installation to study those physical phenomena that can be described through the evaluation of an algebraic function of a complex variable. This is an alternative way to study such phenomena on an interactive graphics terminal. The typical problem used, involving complex variables, is that of…

  5. The karyotype of Festucopsis serpentini (Poaceae Triticeae) from Albania studied by banding techniques and in situ hybridization

    DEFF Research Database (Denmark)

    Linde-Laursen, I.; Seberg, O.; Frederiksen, S.;

    1996-01-01

    The karyotypes of two populations of Festucopsis serpentini (2n = 2x = 14) endemic to Albania were investigated in detail by Giemsa C- and N-banding, AgNO3 staining, and in situ hybridization with an rDNA probe. The complements consisted of 14 large chromosomes, 10 metacentric and 4 SAT-chromosom...

  6. Application of optimization technique to noncrystalline x-ray diffraction microscopy: Guided hybrid input-output method

    Science.gov (United States)

    Chen, Chien-Chun; Miao, Jianwei; Wang, C. W.; Lee, T. K.

    2007-08-01

    We have developed an algorithm that combines the concept of optimization with the conventional hybrid input-output (HIO) algorithm for phase retrieval of oversampled diffraction intensities. In particular, the optimization algorithm of guiding searching direction to locate the global minimum has been implemented. Compared with HIO, this guided HIO algorithm retrieves the lost phase information from diffraction intensities with much better accuracy.

  7. Decisive factor in increase of loading at adjacent segments after lumbar fusion: operative technique, pedicle screws, or fusion itself: biomechanical analysis using finite element

    Science.gov (United States)

    Park, Joon-Hee; Kim, Ho-Joong; Kang, Kyoung-Tak; Kim, Ka-yeon; Chun, Heoung-Jae; Moon, Seong-Hwan; Lee, Hwan-Mo

    2010-03-01

    The aim of this study is to investigate the change in biomechanical milieu following removal of pedicle screws or removal of spinous process with posterior ligament complex in instrumented single level lumbar arthrodesis. We developed and validated a finite element model (FEM) of the intact lumbar spine (L2-4). Four scenarios of L3-4 lumbar fusion were simulated: posterolateral fusion (PLF) at L3-4 using pedicle screw system with preservation of PLC (Pp WiP), L3-4 lumbar posterolateral fusion state after removal of pedicle screw system with preservation of PLC (Pp WoP), L3-4 using pedicle screw system without preservation PLC (Sp WiP), L3-4 lumbar posterolateral fusion state after removal of pedicle screw system without preservation of PLC (Sp WoP). For these models, we investigated the range of motion and maximal Von mises stress of disc in all segments under various moments. All fusion models demonstrated increase in range of motion at adjacent segments compared to the intact model.For the four fusion models, the WiP model s P had the largest increase in range of motion at each adjacent segment. This study demonstrated that removal of pedicle screw system and preservation of PLC after complete lumbar spinal fusion could reduce the stress of adjacent segments synergistically and might have beneficial effects in preventing ASD.

  8. An efficient algorithm for color image segmentation

    Directory of Open Access Journals (Sweden)

    Shikha Yadav

    2016-09-01

    Full Text Available In field of image processing, image segmentation plays an important role that focus on splitting the whole image into segments. Representation of an image so that it can be more easily analysed and involves more information is an important segmentation goal. The process of partitioning an image can be usually realized by Region based, Boundary based or edge based method. In this work a hybrid approach is followed that combines improved bee colony optimization and Tabu search for color image segmentation. The results produced from this hybrid approach are compared with non-sorted particle swarm optimization, non-sorted genetic algorithm and improved bee colony optimization. Results show that the Hybrid algorithm has better or somewhat similar performance as compared to other algorithms that are based on population. The algorithm is successfully implemented on MATLAB.

  9. Obtention of tumor volumes in PET images stacks using techniques of colored image segmentation; Obtencao de volumes tumorais em pilhas de imagens PET usando tecnicas de segmentacao de imagens coloridas

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Jose W.; Lopes Filho, Ferdinand J., E-mail: jose.wilson@recife.ifpe.edu.br [Instituto Federal de Educacao e Tecnologia de Pernambuco (IFPE) Recife, PE (Brazil); Vieira, Igor F., E-mail: igoradiologia@gmail.com [Universidade Federal de Pernambuco (DEN/UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear; Lima, Fernando R.A.; Cordeiro, Landerson P., E-mail: leoxofisico@gmail.com, E-mail: falima@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-NE), Recife, PE (Brazil)

    2014-07-01

    This work demonstrated step by step how to segment color images of the chest of an adult in order to separate the tumor volume without significantly changing the values of the components R (Red), G (Green) and B (blue) of the colors of the pixels. For having information which allow to build color map you need to segment and classify the colors present at appropriate intervals in images. The used segmentation technique is to select a small rectangle with color samples in a given region and then erase with a specific color called 'rubber' the other regions of image. The tumor region was segmented into one of the images available and the procedure is displayed in tutorial format. All necessary computational tools have been implemented in DIP (Digital Image Processing), software developed by the authors. The results obtained, in addition to permitting the construction the colorful map of the distribution of the concentration of activity in PET images will also be useful in future work to enter tumors in voxel phantoms in order to perform dosimetric assessments.

  10. 节段设计原则在面部瘢痕外科治疗中的临床应用%Clinical Application of Segmental Excision Technique in Facial Scar Plasty

    Institute of Scientific and Technical Information of China (English)

    高伟成; 尹康; 胡晓庆; 郑翔宇; 万昌阳; 刘大猛

    2016-01-01

    目的:探讨节段设计原则在面部瘢痕治疗中的应用。方法自2012年1月至2014年6月,对38例面部瘢痕患者,在修复面部瘢痕时,以面部张力线、组织器官活动分区,以及面部凹凸曲面为界,将瘢痕分解成多个节段瘢痕,对多节段瘢痕采用手术切除,常规美容外科技术分层减张缝合。于术后3~6个月手术切口愈合稳定后,将留存的节段间点状瘢痕行手术或点阵激光治疗。结果术后随访1~3年,瘢痕质地、色泽较好,无明显瘢痕挛缩,无明显凹陷畸形。结论针对面部线型瘢痕,根据面部皮肤张力线对其进行多节段分解,采用手术联合激光等综合手段,可以获得较好的美容效果。%Objective To observe the effect of segmental excision technique in the treatment of facial scar. Methods From January 2012 to June 2014, 38 cases with facial scar were treated. Based on the skin tension lines, facial organ zonation and contour lines, the whole scar was segmented into two or more segments. Then segmental scars were excised and repaired by plastic technique. After 3-6 months, the punctuate scars were treated with fractional laser skin regeneration technique or directly excision. Results All cases were followed up for 1 to 3 years. The color and texture of scar were improved, moreover, no apparent contracture, incision lines were obscured. Facial contours were restored without distorting surrounding structures. Conclusion Segmental excision technique combining secondary fractional laser skin regeneration technique for the punctuate scars is an effective method for facial scar treatment, especially irregular linear scar and contracture scar.

  11. 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%.

  12. Microscopic Halftone Image Segmentation

    Institute of Scientific and Technical Information of China (English)

    WANG Yong-gang; YANG Jie; DING Yong-sheng

    2004-01-01

    Microscopic halftone image recognition and analysis can provide quantitative evidence for printing quality control and fault diagnosis of printing devices, while halftone image segmentation is one of the significant steps during the procedure. Automatic segmentation on microscopic dots by the aid of the Fuzzy C-Means (FCM) method that takes account of the fuzziness of halftone image and utilizes its color information adequately is realized. Then some examples show the technique effective and simple with better performance of noise immunity than some usual methods. In addition, the segmentation results obtained by the FCM in different color spaces are compared, which indicates that the method using the FCM in the f1f2f3 color space is superior to the rest.

  13. Remote sensing images segmentation by Deriche's filter and neural network

    Science.gov (United States)

    Koffi, Raphael K.; Solaiman, Basel; Mouchot, Marie-Catherine

    1994-12-01

    An image segmentation method for remote sensing data using hybride techniques is proposed. Edge detection approach for segmentation is considered in our study. Our aim is to integrate segmentation results in further processing namely classification. Images of the land from satellite are often corrupted by noise. On one hand, optimal edge detectors insure good noise immunity. On the other hand, the multi-layer perceptron (MLP) neural network has been found to be suited for classification. So we propose to combine these two techniques to improve segmentation process. Satellites for remote sensing provide several images for the same area, coded differently according to spectral bands. In order to bear in mind spectral and spatial information, neighborhood relation of pixels and different bands are taken into consideration during the classification realized by the neural network. Samples which constituate the training set for the MLP are selected from the third, fourth and fifth band and represent edge and non-edge patterns. Each sample vector is composed of the value of a current pixel in the local maxima image (enhancement image obtained by Deriche's filter) and its 8 nearest neighbors. The proposed method provides satisfactory results for our application and compared to other similar methods.

  14. 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.

  15. Magneto-optical mode conversion in a hybrid glass waveguide made by sol-gel and ion-exchange techniques

    Science.gov (United States)

    Royer, François; Amata, Hadi; Parsy, François; Jamon, Damien; Ghibaudo, Elise; Broquin, Jean-Emmanuel; Neveu, Sophie

    2012-01-01

    The integration of magneto-optical materials with classical technologies being still a difficult problem, this study explores the possibility to realize a mode converter based on a hybrid structure. A composite magneto-optical layer made of a silica/zirconia matrix doped by magnetic nanoparticles is coated on the top face of ion-exchanged glass waveguides. Optical characterizations that have been carried out demonstrated the efficiency of these hybrid structures in terms of lateral confinement. Furthermore, TE to TM mode conversion has been observed when a longitudinal magnetic field is applied to the device. The amount of this conversion is analysed taking into account the magneto-optical confinement and the modal birefringence of the structure.

  16. Recombinant expression of TLR5 proteins by ligand supplementation and a leucine-rich repeat hybrid technique

    OpenAIRE

    Hong, Minsun; Yoon, Sung-il; Wilson, Ian A.

    2012-01-01

    Vertebrate TLR5 directly binds bacterial flagellin proteins and activates innate immune responses against pathogenic flagellated bacteria. Structural and biochemical studies on the TLR5/flagellin interaction have been challenging due to the technical difficulty in obtaining active recombinant proteins of TLR5 ectodomain (TLR5-ECD). We recently succeeded in production of the N-terminal leucine rich repeats (LRRs) of Danio rerio (dr) TLR5-ECD in a hybrid with another LRR protein, hagfish variab...

  17. 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.

  18. Preservation or Restoration of Segmental and Regional Spinal Lordosis Using Minimally Invasive Interbody Fusion Techniques in Degenerative Lumbar Conditions: A Literature Review.

    Science.gov (United States)

    Uribe, Juan S; Myhre, Sue Lynn; Youssef, Jim A

    2016-04-01

    A literature review. The purpose of this study was to review lumbar segmental and regional alignment changes following treatment with a variety of minimally invasive surgery (MIS) interbody fusion procedures for short-segment, degenerative conditions. An increasing number of lumbar fusions are being performed with minimally invasive exposures, despite a perception that minimally invasive lumbar interbody fusion procedures are unable to affect segmental and regional lordosis. Through a MEDLINE and Google Scholar search, a total of 23 articles were identified that reported alignment following minimally invasive lumbar fusion for degenerative (nondeformity) lumbar spinal conditions to examine aggregate changes in postoperative alignment. Of the 23 studies identified, 28 study cohorts were included in the analysis. Procedural cohorts included MIS ALIF (two), extreme lateral interbody fusion (XLIF) (16), and MIS posterior/transforaminal lumbar interbody fusion (P/TLIF) (11). Across 19 study cohorts and 720 patients, weighted average of lumbar lordosis preoperatively for all procedures was 43.5° (range 28.4°-52.5°) and increased 3.4° (9%) (range -2° to 7.4°) postoperatively (P lordosis increased, on average, by 4° from a weighted average of 8.3° preoperatively (range -0.8° to 15.8°) to 11.2° at postoperative time points (range -0.2° to 22.8°) (P lordosis and change in lumbar lordosis (r = 0.413; P = 0.003), wherein lower preoperative lumbar lordosis predicted a greater increase in postoperative lumbar lordosis. Significant gains in both weighted average lumbar lordosis and segmental lordosis were seen following MIS interbody fusion. None of the segmental lordosis cohorts and only two of the 19 lumbar lordosis cohorts showed decreases in lordosis postoperatively. These results suggest that MIS approaches are able to impact regional and local segmental alignment and that preoperative patient factors can impact the extent of correction gained

  19. Magnetic resonance image segmentation using semi-automated software for quantification of knee articular cartilage - initial evaluation of a technique for paired scans

    Energy Technology Data Exchange (ETDEWEB)

    Brem, M.H. [Brigham and Women' s Hospital, Department of Radiology, Boston, MA (United States); Friedrich-Alexander-University Erlangen Nurenberg, Division of Orthopaedic and Trauma Surgery, Department of Surgery, Erlangen (Germany); Lang, P.K.; Neumann, G.; Schlechtweg, P.M.; Yoshioka, H.; Pappas, G.; Duryea, J. [Brigham and Women' s Hospital, Department of Radiology, Boston, MA (United States); Schneider, E. [LLC, SciTrials, Rocky River, OH (United States); Cleveland Clinic, Imaging Institute, Cleveland, OH (United States); Jackson, R.; Yu, J. [Ohio State University, Diabetes and Metabolism and Radiology, Department of Endocrinology, Columbus, OH (United States); Eaton, C.B. [Center for Primary Care and Prevention and the Warren Alpert Medical School of Brown University, Memorial Hospital of Rhode Island, Providence, RI (United States); Hennig, F.F. [Friedrich-Alexander-University Erlangen Nurenberg, Division of Orthopaedic and Trauma Surgery, Department of Surgery, Erlangen (Germany)

    2009-05-15

    Software-based image analysis is important for studies of cartilage changes in knee osteoarthritis (OA). This study describes an evaluation of a semi-automated cartilage segmentation software tool capable of quantifying paired images for potential use in longitudinal studies of knee OA. We describe the methodology behind the analysis and demonstrate its use by determination of test-retest analysis precision of duplicate knee magnetic resonance imaging (MRI) data sets. Test-retest knee MR images of 12 subjects with a range of knee health were evaluated from the Osteoarthritis Initiative (OAI) pilot MR study. Each subject was removed from the magnet between the two scans. The 3D DESS (sagittal, 0.456 mm x 0.365 mm, 0.7 mm slice thickness, TR 16.5 ms, TE 4.7 ms) images were obtained on a 3-T Siemens Trio MR system with a USA Instruments quadrature transmit-receive extremity coil. Segmentation of one 3D-image series was first performed and then the corresponding retest series was segmented by viewing both image series concurrently in two adjacent windows. After manual registration of the series, the first segmentation cartilage outline served as an initial estimate for the second segmentation. We evaluated morphometric measures of the bone and cartilage surface area (tAB and AC), cartilage volume (VC), and mean thickness (ThC.me) for medial/lateral tibia (MT/LT), total femur (F) and patella (P). Test-retest reproducibility was assessed using the root-mean square coefficient of variation (RMS CV%). For the paired analyses, RMS CV % ranged from 0.9% to 1.2% for VC, from 0.3% to 0.7% for AC, from 0.6% to 2.7% for tAB and 0.8% to 1.5% for ThC.me. Paired image analysis improved the measurement precision of cartilage segmentation. Our results are in agreement with other publications supporting the use of paired analysis for longitudinal studies of knee OA. (orig.)

  20. Hybrid FOSS Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Armstrong researchers are continuing their efforts to further develop FOSS technologies. A hybrid FOSS technique (HyFOSS) employs conventional continuous grating...

  1. [Segmental neurofibromatosis].

    Science.gov (United States)

    Zulaica, A; Peteiro, C; Pereiro, M; Pereiro Ferreiros, M; Quintas, C; Toribio, J

    1989-01-01

    Four cases of segmental neurofibromatosis (SNF) are reported. It is a rare entity considered to be a localized variant of neurofibromatosis (NF)-Riccardi's type V. Two cases are male and two female. The lesions are located to the head in a patient and the other three cases in the trunk. No family history nor transmission to progeny were manifested. The rest of the organs are undamaged.

  2. MO-F-CAMPUS-J-05: Toward MRI-Only Radiotherapy: Novel Tissue Segmentation and Pseudo-CT Generation Techniques Based On T1 MRI Sequences

    Energy Technology Data Exchange (ETDEWEB)

    Aouadi, S; McGarry, M; Hammoud, R; Torfeh, T; Perkins, G; Al-Hammadi, N [Hamad Medical Corporation, NCCCR, Doha (Qatar)

    2015-06-15

    Purpose: To develop and validate a 4 class tissue segmentation approach (air cavities, background, bone and soft-tissue) on T1 -weighted brain MRI and to create a pseudo-CT for MRI-only radiation therapy verification. Methods: Contrast-enhanced T1-weighted fast-spin-echo sequences (TR = 756ms, TE= 7.152ms), acquired on a 1.5T GE MRI-Simulator, are used.MRIs are firstly pre-processed to correct for non uniformity using the non parametric, non uniformity intensity normalization algorithm. Subsequently, a logarithmic inverse scaling log(1/image) is applied, prior to segmentation, to better differentiate bone and air from soft-tissues. Finally, the following method is enrolled to classify intensities into air cavities, background, bone and soft-tissue:Thresholded region growing with seed points in image corners is applied to get a mask of Air+Bone+Background. The background is, afterward, separated by the scan-line filling algorithm. The air mask is extracted by morphological opening followed by a post-processing based on knowledge about air regions geometry. The remaining rough bone pre-segmentation is refined by applying 3D geodesic active contours; bone segmentation evolves by the sum of internal forces from contour geometry and external force derived from image gradient magnitude.Pseudo-CT is obtained by assigning −1000HU to air and background voxels, performing linear mapping of soft-tissue MR intensities in [-400HU, 200HU] and inverse linear mapping of bone MR intensities in [200HU, 1000HU]. Results: Three brain patients having registered MRI and CT are used for validation. CT intensities classification into 4 classes is performed by thresholding. Dice and misclassification errors are quantified. Correct classifications for soft-tissue, bone, and air are respectively 89.67%, 77.8%, and 64.5%. Dice indices are acceptable for bone (0.74) and soft-tissue (0.91) but low for air regions (0.48). Pseudo-CT produces DRRs with acceptable clinical visual agreement to CT

  3. Design and Implementation of Yi Automatic Segmentation Technique in Computer%计算机彝文自动分词技术的设计研究

    Institute of Scientific and Technical Information of China (English)

    王成平

    2012-01-01

    The automatic word segmentation is an indispensable basic work of Yi language information processing, As long as Yi language information processing related to the retrieval, translation, syntactic a-nalysis , semantic analysis,it requires the use of word as basic unit. On this basis according to characteristics of Yi language,the automatic word segmentation standard and design of word vocabulary are described. The technology of automatic word segmentation is proposed, which based on established vocabulary of Yi language. The technology includes algorithm selection,system architecture,and implementation process. And sample tests are given,the accuracy rate and speed of word segmentation are quite satisfactory, Finally,on characteristics of Yi language and the difficulty of achieve automatic word segmentation is analyzed.%实现彝语文自动分词是计算机彝文信息处理中一项不可缺少的基础性工作,计算机彝文信息处理只要涉及到信息检索、机器翻译、语法分析、语义分析等方面的应用,就都需要以词为基本的处理单位.论文以彝语言的特点作为出发点,首先提出了计算机彝文分词规则与分词词表的设计思路,其次提出了实现计算机彝文自动分词技术的算法基础、系统结构,以及实现流程,而且进行了抽样测试,其分词的速度和准确率都比较高.论文最后根据彝语言的特点对实现计算机彝文自动分词的难点进行了分析.

  4. Fiber-wireless integrated mobile backhaul network based on a hybrid millimeter-wave and free-space-optics architecture with an adaptive diversity combining technique.

    Science.gov (United States)

    Zhang, Junwen; Wang, Jing; Xu, Yuming; Xu, Mu; Lu, Feng; Cheng, Lin; Yu, Jianjun; Chang, Gee-Kung

    2016-05-01

    We propose and experimentally demonstrate a novel fiber-wireless integrated mobile backhaul network based on a hybrid millimeter-wave (MMW) and free-space-optics (FSO) architecture using an adaptive combining technique. Both 60 GHz MMW and FSO links are demonstrated and fully integrated with optical fibers in a scalable and cost-effective backhaul system setup. Joint signal processing with an adaptive diversity combining technique (ADCT) is utilized at the receiver side based on a maximum ratio combining algorithm. Mobile backhaul transportation of 4-Gb/s 16 quadrature amplitude modulation frequency-division multiplexing (QAM-OFDM) data is experimentally demonstrated and tested under various weather conditions synthesized in the lab. Performance improvement in terms of reduced error vector magnitude (EVM) and enhanced link reliability are validated under fog, rain, and turbulence conditions.

  5. The Hybrid Programming Technique Of Calling MATLAB Library Functions From Visual C++%Visual C++调用MATLAB函数库的混合编程技术

    Institute of Scientific and Technical Information of China (English)

    徐治

    2015-01-01

    The Visual C++ and MATLAB hybrid programming technique uses VC++ as the powerful software development tool, and directly calls the immense MATLAB algorithm function library while implementing a sophisti-cated algorithm. This approach can achieve the complementation of merits and greatly reduce the coding time of so-phisticated algorithm. This paper introduces the principle of hybrid programming, then details the MATLAB compiler based techniques of coding and project configuration which calls MATLAB function library from VC++.%Visual C++与MATLAB的混合编程技术是以VC++作为强有力的软件开发工具,而在实现复杂算法时则直接调用MATLAB涵盖很广的算法函数库。这种方式可以做到优势互补,大大减少复杂算法的编码时间。本文介绍了混合编程的基本原理,并详细介绍了基于MATLAB编译器的VC++调用MATLAB函数库的代码编写及项目配置等方面的技术。

  6. Hybrid Brain–Computer Interface Techniques for Improved Classification Accuracy and Increased Number of Commands: A Review

    Directory of Open Access Journals (Sweden)

    Keum-Shik Hong

    2017-07-01

    Full Text Available In this article, non-invasive hybrid brain–computer interface (hBCI technologies for improving classification accuracy and increasing the number of commands are reviewed. Hybridization combining more than two modalities is a new trend in brain imaging and prosthesis control. Electroencephalography (EEG, due to its easy use and fast temporal resolution, is most widely utilized in combination with other brain/non-brain signal acquisition modalities, for instance, functional near infrared spectroscopy (fNIRS, electromyography (EMG, electrooculography (EOG, and eye tracker. Three main purposes of hybridization are to increase the number of control commands, improve classification accuracy and reduce the signal detection time. Currently, such combinations of EEG + fNIRS and EEG + EOG are most commonly employed. Four principal components (i.e., hardware, paradigm, classifiers, and features relevant to accuracy improvement are discussed. In the case of brain signals, motor imagination/movement tasks are combined with cognitive tasks to increase active brain–computer interface (BCI accuracy. Active and reactive tasks sometimes are combined: motor imagination with steady-state evoked visual potentials (SSVEP and motor imagination with P300. In the case of reactive tasks, SSVEP is most widely combined with P300 to increase the number of commands. Passive BCIs, however, are rare. After discussing the hardware and strategies involved in the development of hBCI, the second part examines the approaches used to increase the number of control commands and to enhance classification accuracy. The future prospects and the extension of hBCI in real-time applications for daily life scenarios are provided.

  7. Artifact reduction in multichannel pervasive EEG using hybrid WPT-ICA and WPT-EMD signal decomposition techniques

    CERN Document Server

    Bono, Valentina; Das, Saptarshi; Maharatna, Koushik

    2014-01-01

    In order to reduce the muscle artifacts in multi-channel pervasive Electroencephalogram (EEG) signals, we here propose and compare two hybrid algorithms by combining the concept of wavelet packet transform (WPT), empirical mode decomposition (EMD) and Independent Component Analysis (ICA). The signal cleaning performances of WPT-EMD and WPT-ICA algorithms have been compared using a signal-to-noise ratio (SNR)-like criterion for artifacts. The algorithms have been tested on multiple trials of four different artifact cases viz. eye-blinking and muscle artifacts including left and right hand movement and head-shaking.

  8. 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.

  9. Hybrid-Thresholding based Image Super-Resolution Technique by the use of Triplet Half-Band Wavelets

    Science.gov (United States)

    Chopade, Pravin B.; Rahulkar, Amol D.; Patil, Pradeep M.

    2016-12-01

    This paper presents a modified image super-resolution scheme based on the wavelet coefficients hybrid-thresholding by the use of triplet half-band wavelets (THW) derived from the generalized half-band polynomial. At first, discrete wavelet transform (DWT) is obtained from triplet half-band kernels and it applied on the low-resolution image to obtain the high frequency sub-bands. These high frequency sub-bands and the original low-resolution image are interpolated to enhance the resolution. Second, stationary wavelet transform is obtained by using THW, which is employed to minimize the loss due to the use of DWT. In addition, hybrid thresholding scheme on wavelet coefficients scheme is proposed on these estimated high-frequency sub-bands in order to reduce the spatial domain noise. These sub-bands are combined together by inverse discrete wavelet transform obtained from THW to generate a high-resolution image. The proposed approach is validated by comparing the quality metrics with existing filter banks and well-known super-resolution scheme.

  10. An enhanced security solution for electronic medical records based on AES hybrid technique with SOAP/XML and SHA-1.

    Science.gov (United States)

    Kiah, M L Mat; Nabi, Mohamed S; Zaidan, B B; Zaidan, A A

    2013-10-01

    This study aims to provide security solutions for implementing electronic medical records (EMRs). E-Health organizations could utilize the proposed method and implement recommended solutions in medical/health systems. Majority of the required security features of EMRs were noted. The methods used were tested against each of these security features. In implementing the system, the combination that satisfied all of the security features of EMRs was selected. Secure implementation and management of EMRs facilitate the safeguarding of the confidentiality, integrity, and availability of e-health organization systems. Health practitioners, patients, and visitors can use the information system facilities safely and with confidence anytime and anywhere. After critically reviewing security and data transmission methods, a new hybrid method was proposed to be implemented on EMR systems. This method will enhance the robustness, security, and integration of EMR systems. The hybrid of simple object access protocol/extensible markup language (XML) with advanced encryption standard and secure hash algorithm version 1 has achieved the security requirements of an EMR system with the capability of integrating with other systems through the design of XML messages.

  11. Implementing a Novel Hybrid Maximum Power Point Tracking Technique in DSP via Simulink/MATLAB under Partially Shaded Conditions

    Directory of Open Access Journals (Sweden)

    Shahrooz Hajighorbani

    2016-01-01

    Full Text Available This paper presents a hybrid maximum power point tracking (MPPT method to detect the global maximum power point (GMPP under partially shaded conditions (PSCs, which have more complex characteristics with multiple peak power points. The hybrid method can track the GMPP when a partial shadow occurs either before or after acquiring the MPP under uniform conditions. When PS occurs after obtaining the MPP during uniform conditions, the new operating point should be specified by the modified linear function, which reduces the searching zone of the GMPP and has a significant effect on reducing the reaching time of the GMPP. Simultaneously, the possible MPPs are scanned and stored when shifting the operating point to a new reference voltage. Finally, after determining the possible location of the GMPP, the GMPP is obtained using the modified P&O. Conversely, when PS occurs before obtaining the MPP, the referenced MPP should be specified. Thus, after recognizing the possible location of the GMPP, the modified P&O can be used to obtain the GMPP. The simulation and experimental implementations for the proposed algorithm are performed with different scenarios of shadowing under different irradiations, which clearly indicate that the proposed method is robust and has a fast tracking speed. Moreover, this work presents the load sizing method for PSCs to avoid controller failure when detecting the GMPP. Additionally, in this paper, the user-friendly method for programming the digital signal processing (DSP via Simulink/MATLAB is presented in detail.

  12. Reconstruction of irradiated mandible after segmental resection of osteoradionecrosis-a technique employing a microvascular latissimus dorsi flap and subsequent particulate iliac bone grafting

    DEFF Research Database (Denmark)

    Hillerup, Soren; Elberg, Jens Jorgen; Thorn, Jens Jorgen

    2014-01-01

    The fibula osteocutaneous flap has revolutionized the options of mandibular segmental defect bridging in osteoradionecrosis (ORN). In selected cases, however, the fibula flap is not an option because of atherosclerosis or other features that compromise the vascularity of the lower leg and foot......, and the defect site was primed with a LD musculocutaneous flap wrapped around the reconstruction plate to bring in vascularized tissue and optimize healing conditions for a subsequent particulate iliac free bone graft reconstruction. The management of defect closure was successful in all 15 patients. Twelve...

  13. Mixed segmentation

    DEFF Research Database (Denmark)

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

    This book is about using recent developments in the fields of data analytics and data visualization to frame new ways of identifying target groups in media communication. Based on a mixed-methods approach, the authors combine psychophysiological monitoring (galvanic skin response) with textual...... 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...

  14. A comparative study on medical image segmentation methods

    OpenAIRE

    Praylin Selva Blessy SELVARAJ ASSLEY; Helen Sulochana CHELLAKKON

    2014-01-01

    Image segmentation plays an important role in medical images. It has been a relevant research area in computer vision and image analysis. Many segmentation algorithms have been proposed for medical images. This paper makes a review on segmentation methods for medical images. In this survey, segmentation methods are divided into five categories: region based, boundary based, model based, hybrid based and atlas based. The five different categories with their principle ideas, advantages and disa...

  15. Research of clinical application of segmented arch technique for deep overbite correction%片段弓在深覆(牙合)矫治中的临床应用研究

    Institute of Scientific and Technical Information of China (English)

    王宝红; 周洪

    2012-01-01

    目的:探讨片段弓矫治重度深覆(牙合)患者的作用机制及临床作用要点.方法:对16例成人重度深覆(牙合)患者,用片段弓来打开咬合,并对咬合打开前后的硬软组织变化进行分析.结果:①戴用片段弓3~6个月(平均4.5月)后,覆(牙合)达到正常,切牙段出现整体压低,而对支抗后牙几乎无影响,上颌磨牙的角度、垂直距离与上颌切牙的角度均未改变.②压低上切牙时平均每月0.47mm,共压低了2.12mm,6~8周后可看见压低效果.③在观察期内,随着上中切牙的压低,上切牙唇下暴露量减少,上下唇间隙平均减小,并且上唇有下降趋势.结论:片段弓矫治深覆(牙合)主要依靠上下前牙的整体压低,因此片段弓适用于下颌平面角较大、前牙过长或前牙齿槽突发育过度、上下唇间隙过大、上切牙唇下暴露较多的重度深覆牙患者.%Objective The purpose of this study was to investigate the efficiency of segmented arch technique in deep overbite correction. Methods A total of 16 Ⅱ ~ I degree deepbite female patients ,aged from 18 to 32 (average 22.3 years old),were selected to be treated with segmented arch technique, The profile change were studied using the computer-aid X-ray cephalometric analysis.Periapical resorption was observed on periapical radiography.SPSS 10.0 statistical software was used to calculate means and standard deviation. Paired T-test was concluded to determine the statistical significance of the mean values,Ridit test was used to evaluate the degree of the periapical resorption. Results ①After segmented arch technique was used 3 to 6 months.overbite corrected,incisor segment was been intruded absolutely.while the angle of maxilla incisor and molar had no change,also had the vertical dimension of maxilla molar.So absolute intrusion of incisor was statistically significant.almost had no influence to the anchorage dental.② Maxillary incisor intruded 2.12mm,averaged 0.47mm

  16. Thermal conductivity prediction of nanoscale phononic crystal slabs using a hybrid lattice dynamics-continuum mechanics technique

    Directory of Open Access Journals (Sweden)

    Charles M. Reinke

    2011-12-01

    Full Text Available Recent work has demonstrated that nanostructuring of a semiconductor material to form a phononic crystal (PnC can significantly reduce its thermal conductivity. In this paper, we present a classical method that combines atomic-level information with the application of Bloch theory at the continuum level for the prediction of the thermal conductivity of finite-thickness PnCs with unit cells sized in the micron scale. Lattice dynamics calculations are done at the bulk material level, and the plane-wave expansion method is implemented at the macrosale PnC unit cell level. The combination of the lattice dynamics-based and continuum mechanics-based dispersion information is then used in the Callaway-Holland model to calculate the thermal transport properties of the PnC. We demonstrate that this hybrid approach provides both accurate and efficient predictions of the thermal conductivity.

  17. Thermal conductivity prediction of nanoscale phononic crystal slabs using a hybrid lattice dynamics-continuum mechanics technique

    Science.gov (United States)

    Reinke, Charles M.; Su, Mehmet F.; Davis, Bruce L.; Kim, Bongsang; Hussein, Mahmoud I.; Leseman, Zayd C.; Olsson-III, Roy H.; El-Kady, Ihab

    2011-12-01

    Recent work has demonstrated that nanostructuring of a semiconductor material to form a phononic crystal (PnC) can significantly reduce its thermal conductivity. In this paper, we present a classical method that combines atomic-level information with the application of Bloch theory at the continuum level for the prediction of the thermal conductivity of finite-thickness PnCs with unit cells sized in the micron scale. Lattice dynamics calculations are done at the bulk material level, and the plane-wave expansion method is implemented at the macrosale PnC unit cell level. The combination of the lattice dynamics-based and continuum mechanics-based dispersion information is then used in the Callaway-Holland model to calculate the thermal transport properties of the PnC. We demonstrate that this hybrid approach provides both accurate and efficient predictions of the thermal conductivity.

  18. The characteristics of novel bimodal Ag-TiO2 nanoparticles generated by hybrid laser-ultrasonic technique

    Science.gov (United States)

    Hamad, Abubaker; Li, Lin; Liu, Zhu; Zhong, Xiang Li; Burke, Grace; Wang, Tao

    2016-04-01

    Silver-titania (Ag-TiO2) nanoparticles with smaller Ag nanoparticles attached to larger TiO2 nanoparticles were generated by hybrid ultrasonic vibration and picosecond laser ablation of Ag and Ti bulk targets in deionised water, for the first time. The laser has a wavelength of 1064 nm and a pulse duration of 10 ps. It was observed that without the ultrasonic vibration, Ag and TiO2 nanoparticles did not combine, thus the role of ultrasonic vibration is essential. In addition, colloidal TiO2 and Ag nanoparticles were generated separately for comparison under the same laser beam characteristics and process conditions. The absorption spectra of colloidal Ag-TiO2 cluster nanoparticles were examined by UV-Vis spectroscopy, and size distribution was characterised using transmission electron microscopy. The morphology and composition of Ag-TiO2 nanoparticles were examined using scanning transmission electron microscopy in high-angle annular dark field, and energy-dispersive X-ray spectroscopy. The crystalline structures were investigated by X-ray diffraction. The size of larger TiO2 particles was in the range 30-150 nm, and the smaller-sized Ag nanoparticles attached to the TiO2 was mainly in the range of 10-15 nm. The yield is more than 50 % with the remaining nanoparticles in the form of uncombined Ag and TiO2. The nanoparticles generated had strong antibacterial effects as tested against E. coli. A discussion is given on the role of ultrasonic vibration in the formation of Ag-TiO2 hybrid nanoparticles by picosecond laser ablation.

  19. 基于混合能量活动轮廓模型的人脸分割方法∗%Face Segmentation Based on a Hybrid Energy Based Active Contour Model

    Institute of Scientific and Technical Information of China (English)

    龚勋; 王国胤; 李天瑞; 李昕昕; 夏冉; 冯林

    2013-01-01

    Influenced by factors like facial features, accessories, facial outer contours are extracted by the traditional geometric active contour models and conatin depressions and result in fragmentation, etc. To address these problems, according to the characteristics of human face image, the study proposes a hybrid energy based geometric active contour model via combining the energies of contour outer tension force and skin color with the global energy. First an outwards tension force, computed by neighborhoods of contour points, is added to the contour. This force makes the curve insusceptible to the facial features and accessories, but move towards to the facial outer contour. As skin color is the major feature of a human face. Skin color energy is integrated to ensure a more robust algorithm. Finally, an improved skin tone detection model is proposed based on the single Gaussian function. It could generate initial position that are close to the real facial contour, laying a good foundation for contour evolution. The proposed method gives essentially accurate face segmentations on two public face databases. Take the manually segmentations as the ground truth, the proposed method compares favorably to both traditional global and local energy algorithms. Next a more challenging set containing 100 faces of life photos with variances in pose is introduced with illumination and backgrounds. Segmentation results have validated that the proposed method could extract outer facial contour steadily and accurately under such variances.%  由于受到面部五官、饰物等因素的影响,传统几何活动轮廓模型获取人脸外轮廓会产生凹陷、分片等现象。针对人脸图像的特点,将边缘外张力能量及肤色能量与全局能量结合,提出一种基于混合能量泛函的几何活动轮廓模型,有效地避免了这些问题。首先,根据演化曲线的邻域信息赋予边缘点向外的张力,使曲线能够克服面部特征及

  20. Accurate and Fast Iris Segmentation

    Directory of Open Access Journals (Sweden)

    G. AnnaPoorani,

    2010-06-01

    Full Text Available A novel iris segmentation approach for noisy iris is proposed in this paper. The proposed approach comprises of specular reflection removal, pupil localization, iris localization and eyelid localization. Reflection map computation is devised to get the reflection ROI of eye image using adaptive threshold technique. Bilinear interpolation is used to fill these reflection points in the eye image. Variant of edge-based segmentation technique is adopted to detect the pupil boundary from the eye image. Gradient based heuristic approach is devised to detect the iris boundary from theeye image. Eyelid localization is designed to detect the eyelids using the edge detection and curve fitting. Feature sequence combined into spatial domain segments the iris texture patterns properly. Empirical results show that the proposed approach is effective and suitable to deal with the noisy eye image for iris segmentation.

  1. Segmented blockcopolymers with uniform amide segments

    NARCIS (Netherlands)

    Husken, D.; Krijgsman, J.; Gaymans, R.J.

    2004-01-01

    Segmented blockcopolymers based on poly(tetramethylene oxide) (PTMO) soft segments and uniform crystallisable tetra-amide segments (TxTxT) are made via polycondensation. The PTMO soft segments, with a molecular weight of 1000 g/mol, are extended with terephthalic groups to a molecular weight of 6000

  2. Distance measures for image segmentation evaluation

    OpenAIRE

    Monteiro, Fernando C.; Campilho, Aurélio C.

    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...

  3. Principles of Video Segmentation Scenarios

    Directory of Open Access Journals (Sweden)

    M. R. KHAMMAR

    2013-05-01

    Full Text Available Video segmentation is the first step toward automatic video processing such as browsing, retrieval, and indexing. Many algorithms and techniques have been proposed a few years ago. They can cover the topic of video segmentation from different angles and it is beneficial to review the most important properties of them in brief in order to clarify the subject and find out the latest challenges and drawbacks. In this paper, the important parameters which are involved in video segmentation are discussed and video shot detection systems are compared together.

  4. Investigation of kinetics and thermodynamics of DNA hybridization by means of 2-D fluorescence spectroscopy and soft/hard modeling techniques.

    Science.gov (United States)

    Ebrahimi, Sara; Kompany-Zareh, Mohsen

    2016-02-01

    Reversible hybridization reaction plays a key role in fundamental biological processes, in many laboratory techniques, and also in DNA based sensing devices. Comprehensive investigation of this process is, therefore, essential for the development of more sophisticated applications. Kinetics and thermodynamics of the hybridization reaction, as a second order process, are systematically investigated with the aid of the soft and hard chemometric methods. Labeling two complementary 21 mer DNA single strands with FAM and Texas red fluorophores, enabled recording of the florescence excitation-emission matrices during the experiments which led to three-way data sets. The presence of fluorescence resonance energy transfer in excitation and emission modes and the closure in concentration mode, made the three-way data arrays rank deficient. To acquire primary chemical information, restricted Tucker3 as a soft method was employed. Herein a model-based method, hard restricted trilinear decomposition, is introduced for in depth analysis of rank deficient three-way data sets. By employing proposed hard method, the nonlinear model parameters as well as the correct profiles could be estimated. In addition, a simple constraint is presented to extract chemically reasonable output profiles regarding the core elements of restricted Tucker3 model.

  5. Laser alloying metallographic study by image segmentation techniques; Estudio de las fases metalograficas de aleaciones superficiales obtenidas por tecnicas laser mediante segmentacion de imagenes

    Energy Technology Data Exchange (ETDEWEB)

    Tejera, M.; Mavilio, A.; Fernandez, M.; Muniz, G.; Varela, R.

    2005-07-01

    In this work are presented the metallographic characteristics of an alloy obtained by means of the application of a laser beam on a titanium carbide powder layer deposited in a steel surface. The treated steel was studied by optic microscopy and three well defined metallographic interesting zones were observed. Texture patterns corresponding of these zones were obtained from these images. The identification and the segmentation of these zones using the method of Difference Histogram (DH) and a Run Length variant (RL) is realized in sections of images of steels treated with the same procedure. A procedure for the qualitative detection of these zones in laser steel alloying and to study the texture modification in the heat affected zone is obtained. In this way is evaluated the proposed descriptors effectiveness: (Author)

  6. Development and Application of Power Markets Segmentation Technique%电力客户细分技术应用研究

    Institute of Scientific and Technical Information of China (English)

    罗佳; 郑方鹏; 姚刚

    2016-01-01

    随着新的电改方案《关于进一步深化电力体制改革的若干意见》(中发〔2015〕9号)及其配套文件的印发,新一轮的电力体制改革已拉开序幕。在这种形势下,传统的直面客户的电网企业,必须在营销理念、营销方式、营销技术等方面进行调整,以便做好电网建设,更好地服务于广大客户。基于电力客户细分管理理论是探索的可能应用手段之一。文章就客户细分技术在贵州电力市场试验性研究进行分析,以期其能作为一种有效的营销管理工具。%The new power system reform has been on after the document No. ZF[2015]9 and its supporting documents issued. In this new situation, the traditional face of the customer 's power grid enterprises have to read just their market ideas, operation mode and marketing methods to serve better for their customers, power grid operating and construction. The strategy based upon market segmentation is one of the methods. The market segmentation experiment in Guizhou was described and expect to ifnd a suitable market tools.

  7. Photoelastic Stress Analysis by Use of Hybrid Technique and Fringe Phase Shifting Method%利用混合法和相移技术的光弹性应力分析

    Institute of Scientific and Technical Information of China (English)

    白泰铉

    2006-01-01

    Photoelastic fringe patterns for stress analysis are investigated by use of hybrid technique and fringe phase shift method. The first one is a hybrid method which combines the conformal mapping technique and measured data away from the edge of a geometric discontinuity. Photoelastic data are hybridized with complex variable/mapping techniques to calculate photoelastic stress-field around a circular hole or an elliptical hole in plates under uniaxial tensile loading. This method determines full-field stresses in perforated finite tensile plates containing either a circular or an elliptical hole. The second one is a fringe phase shift method to separate isochromatics and isoclinics from photoelastic fringes of a circular disk under diametric compression by use of phase shift method. Digitally determined isochromatics and isoclinics are agreed well with those of manual measurements.

  8. Progress on Application of Yeast Two-hybrid Technique%酵母双杂交技术应用进展

    Institute of Scientific and Technical Information of China (English)

    王婷; 葛怀娜; 郭宏

    2015-01-01

    Yeast two-hybrid system is one of the most powerful and widely used method to detect protein-protein interaction in living cells.Yeast two-hybrid technique is cost-effective, easy to operate, can reach the whole-genome level, and identify the interaction between different varieties.Compared with the traditional detected method, it has obvious advantages and has been applied in more and more fields.In this paper, the yeast two-hybrid technology principle and application were reviewed, including the applications on discovering new protein and proteins’new function, setting up the protein linkage map, studing of human genome DNA library, screening target for drug, and so on.The paper was expected to provide reference for the application of yeast two-hybrid system.%酵母双杂交技术是鉴定蛋白互作最有效和最广泛的分子生物学技术。该技术能直接作用于活细胞,检测细胞内蛋白质互作,具有成本低、易操作、可达到全基因组水平、能进行品种间的互作鉴定等诸多优点。较之传统的检测方法有明显优势,已在越来越多的领域得到应用。对酵母双杂交的技术原理以及应用进行了综述,介绍了该技术在发现新蛋白质、探究蛋白质功能、建立基因组蛋白连锁图、研究人类DNA文库和筛选药物作用位点等方面的重要应用,以期为该技术的广泛应用提供参考。

  9. Realization of MMI Power Splitter by UV-light Imprinting Technique Using Hybrid Sol-Gel SiO2 Materials

    Institute of Scientific and Technical Information of China (English)

    WANG Yue; WU Yuan-Da; LI Jian-Guang; WANG Hong-Jie; HU Xiong-Wei

    2008-01-01

    An efficient fabrication scheme of buried ridge, waveguide devices is demonstrated by UV-light imprinting technique using organic-inorganic hybrid sol-gel Zr-doped SiO2 materials. The refractive indices of a guiding layer and a cladding layer for the buried ridge waveguide structure are 1.537 and 1.492 measured at 1550nm, respectively. The tested results show more circular mode profiles due to existence of the cladding layer. A buried ridge single-mode waveguide operating at 1550nm has a low propagation loss (O.088 dB/cm) and the 1 × 2 MMI power splitter exhibits uniform outputs, with a very low splitting loss of O.029dB at 1549nm.

  10. Suppression subtraction hybridization (SSH) and macroarray techniques reveal differential gene expression profiles in brain of sea bream infected with nodavirus.

    Science.gov (United States)

    Dios, S; Poisa-Beiro, L; Figueras, A; Novoa, B

    2007-03-01

    Despite of the impact that viruses have on aquatic organisms, relatively little is known on how fish fight against these infections. In this work, the brain gene expression pattern of sea bream (Sparus aurata) in response to nodavirus infection was investigated. We used the suppression subtractive hybridization (SSH) method to generate a subtracted cDNA library enriched with gene transcripts differentially expressed after 1 day post-infection. Some of the ESTs from the infected tissues fell in gene categories related to stress and immune responses. For the reverse library (ESTs expressed in controls compared with infected tissues) the most abundant transcripts were of ribosomal and mitochondrial nature. Several ESTs potentially induced by virus exposure were selected for in vivo expression studies. We observed a clear difference in expression between infected and control samples for two candidate genes, ubiquitin conjugating enzyme 7 interacting protein, which seems to play an important role in apoptosis and the interferon induced protein with helicase C domain 1 (mda-5) that contributes to apoptosis and regulates the type I IFN production, a key molecule of the antiviral innate response in most organisms.

  11. Crude oil price forecasting based on hybridizing wavelet multiple linear regression model, particle swarm optimization techniques, and principal component analysis.

    Science.gov (United States)

    Shabri, Ani; Samsudin, Ruhaidah

    2014-01-01

    Crude oil prices do play significant role in the global economy and are a key input into option pricing formulas, portfolio allocation, and risk measurement. In this paper, a hybrid model integrating wavelet and multiple linear regressions (MLR) is proposed for crude oil price forecasting. In this model, Mallat wavelet transform is first selected to decompose an original time series into several subseries with different scale. Then, the principal component analysis (PCA) is used in processing subseries data in MLR for crude oil price forecasting. The particle swarm optimization (PSO) is used to adopt the optimal parameters of the MLR model. To assess the effectiveness of this model, daily crude oil market, West Texas Intermediate (WTI), has been used as the case study. Time series prediction capability performance of the WMLR model is compared with the MLR, ARIMA, and GARCH models using various statistics measures. The experimental results show that the proposed model outperforms the individual models in forecasting of the crude oil prices series.

  12. Prediction of peak ground acceleration of Iran’s tectonic regions using a hybrid soft computing technique

    Institute of Scientific and Technical Information of China (English)

    Mostafa Gandomi; Mohsen Soltanpour; Mohammad R. Zolfaghari; Amir H. Gandomi

    2016-01-01

    A new model is derived to predict the peak ground acceleration (PGA) utilizing a hybrid method coupling artificial neural network (ANN) and simulated annealing (SA), called SA-ANN. The proposed model re-lates PGA to earthquake source to site distance, earthquake magnitude, average shear-wave velocity, faulting mechanisms, and focal depth. A database of strong ground-motion recordings of 36 earthquakes, which happened in Iran’s tectonic regions, is used to establish the model. For more validity verification, the SA-ANN model is employed to predict the PGA of a part of the database beyond the training data domain. The proposed SA-ANN model is compared with the simple ANN in addition to 10 well-known models proposed in the literature. The proposed model performance is superior to the single ANN and other existing attenuation models. The SA-ANN model is highly correlated to the actual records (R ¼ 0.835 and r ¼ 0.0908) and it is subsequently converted into a tractable design equation.

  13. Crude Oil Price Forecasting Based on Hybridizing Wavelet Multiple Linear Regression Model, Particle Swarm Optimization Techniques, and Principal Component Analysis

    Directory of Open Access Journals (Sweden)

    Ani Shabri

    2014-01-01

    Full Text Available Crude oil prices do play significant role in the global economy and are a key input into option pricing formulas, portfolio allocation, and risk measurement. In this paper, a hybrid model integrating wavelet and multiple linear regressions (MLR is proposed for crude oil price forecasting. In this model, Mallat wavelet transform is first selected to decompose an original time series into several subseries with different scale. Then, the principal component analysis (PCA is used in processing subseries data in MLR for crude oil price forecasting. The particle swarm optimization (PSO is used to adopt the optimal parameters of the MLR model. To assess the effectiveness of this model, daily crude oil market, West Texas Intermediate (WTI, has been used as the case study. Time series prediction capability performance of the WMLR model is compared with the MLR, ARIMA, and GARCH models using various statistics measures. The experimental results show that the proposed model outperforms the individual models in forecasting of the crude oil prices series.

  14. Human Segmentation Using Haar-Classifier

    Directory of Open Access Journals (Sweden)

    Dharani S

    2014-07-01

    Full Text Available Segmentation is an important process in many aspects of multimedia applications. Fast and perfect segmentation of moving objects in video sequences is a basic task in many computer visions and video investigation applications. Particularly Human detection is an active research area in computer vision applications. Segmentation is very useful for tracking and recognition the object in a moving clip. The motion segmentation problem is studied and reviewed the most important techniques. We illustrate some common methods for segmenting the moving objects including background subtraction, temporal segmentation and edge detection. Contour and threshold are common methods for segmenting the objects in moving clip. These methods are widely exploited for moving object segmentation in many video surveillance applications, such as traffic monitoring, human motion capture. In this paper, Haar Classifier is used to detect humans in a moving video clip some features like face detection, eye detection, full body, upper body and lower body detection.

  15. Analysis of High Yield and Efficiency Technique in Hybrid Rice Zhongzheyou No.1%杂交水稻中浙优1号高产高效技术途径分析

    Institute of Scientific and Technical Information of China (English)

    刘伟明

    2009-01-01

    To understand the high yield and efficiency technique in hybrid rice Zhongzheyou No.1, we conducted the correlation analysis, regression analysis and path analysis of hybrid rice Zhongzheyou No.1 based on the data of its ear, grain and weight at different yield levels. From this study, we put forward the high yield and efficiency technique in Zhongzheyou No.1: on the basis of certain effective ear number, filled grains per ear should be mainly targeted with a consideration to 1 000-grain weight.

  16. A hybrid color space for skin detection using genetic algorithm heuristic search and principal component analysis technique.

    Directory of Open Access Journals (Sweden)

    Mahdi Maktabdar Oghaz

    Full Text Available Color is one of the most prominent features of an image and used in many skin and face detection applications. Color space transformation is widely used by researchers to improve face and skin detection performance. Despite the substantial research efforts in this area, choosing a proper color space in terms of skin and face classification performance which can address issues like illumination variations, various camera characteristics and diversity in skin color tones has remained an open issue. This research proposes a new three-dimensional hybrid color space termed SKN by employing the Genetic Algorithm heuristic and Principal Component Analysis to find the optimal representation of human skin color in over seventeen existing color spaces. Genetic Algorithm heuristic is used to find the optimal color component combination setup in terms of skin detection accuracy while the Principal Component Analysis projects the optimal Genetic Algorithm solution to a less complex dimension. Pixel wise skin detection was used to evaluate the performance of the proposed color space. We have employed four classifiers including Random Forest, Naïve Bayes, Support Vector Machine and Multilayer Perceptron in order to generate the human skin color predictive model. The proposed color space was compared to some existing color spaces and shows superior results in terms of pixel-wise skin detection accuracy. Experimental results show that by using Random Forest classifier, the proposed SKN color space obtained an average F-score and True Positive Rate of 0.953 and False Positive Rate of 0.0482 which outperformed the existing color spaces in terms of pixel wise skin detection accuracy. The results also indicate that among the classifiers used in this study, Random Forest is the most suitable classifier for pixel wise skin detection applications.

  17. A hybrid color space for skin detection using genetic algorithm heuristic search and principal component analysis technique.

    Science.gov (United States)

    Maktabdar Oghaz, Mahdi; Maarof, Mohd Aizaini; Zainal, Anazida; Rohani, Mohd Foad; Yaghoubyan, S Hadi

    2015-01-01

    Color is one of the most prominent features of an image and used in many skin and face detection applications. Color space transformation is widely used by researchers to improve face and skin detection performance. Despite the substantial research efforts in this area, choosing a proper color space in terms of skin and face classification performance which can address issues like illumination variations, various camera characteristics and diversity in skin color tones has remained an open issue. This research proposes a new three-dimensional hybrid color space termed SKN by employing the Genetic Algorithm heuristic and Principal Component Analysis to find the optimal representation of human skin color in over seventeen existing color spaces. Genetic Algorithm heuristic is used to find the optimal color component combination setup in terms of skin detection accuracy while the Principal Component Analysis projects the optimal Genetic Algorithm solution to a less complex dimension. Pixel wise skin detection was used to evaluate the performance of the proposed color space. We have employed four classifiers including Random Forest, Naïve Bayes, Support Vector Machine and Multilayer Perceptron in order to generate the human skin color predictive model. The proposed color space was compared to some existing color spaces and shows superior results in terms of pixel-wise skin detection accuracy. Experimental results show that by using Random Forest classifier, the proposed SKN color space obtained an average F-score and True Positive Rate of 0.953 and False Positive Rate of 0.0482 which outperformed the existing color spaces in terms of pixel wise skin detection accuracy. The results also indicate that among the classifiers used in this study, Random Forest is the most suitable classifier for pixel wise skin detection applications.

  18. Variable weight Khazani-Syed code using hybrid fixed-dynamic technique for optical code division multiple access system

    Science.gov (United States)

    Anas, Siti Barirah Ahmad; Seyedzadeh, Saleh; Mokhtar, Makhfudzah; Sahbudin, Ratna Kalos Zakiah

    2016-10-01

    Future Internet consists of a wide spectrum of applications with different bit rates and quality of service (QoS) requirements. Prioritizing the services is essential to ensure that the delivery of information is at its best. Existing technologies have demonstrated how service differentiation techniques can be implemented in optical networks using data link and network layer operations. However, a physical layer approach can further improve system performance at a prescribed received signal quality by applying control at the bit level. This paper proposes a coding algorithm to support optical domain service differentiation using spectral amplitude coding techniques within an optical code division multiple access (OCDMA) scenario. A particular user or service has a varying weight applied to obtain the desired signal quality. The properties of the new code are compared with other OCDMA codes proposed for service differentiation. In addition, a mathematical model is developed for performance evaluation of the proposed code using two different detection techniques, namely direct decoding and complementary subtraction.

  19. A comparative analysis of different hybrid MCDM techniques considering a case of selection of 3D printers

    Directory of Open Access Journals (Sweden)

    Debapriyo Paul

    2015-07-01

    Full Text Available A multitude of techniques fall under the domain of Multi- Criteria Decision Making (MCDM which is used to select the best alternative among the available ones. The objective of this paper is to compare some of these techniques with respect to the problem of selection of 3D printers, which is associated with multiple attributes. The weights of the criteria were determined using analytical network process (ANP. Next, the alternatives were ranked using three different MCDM techniques- 1.TOPSIS which ranks alternatives having the shortest distance to the ideal solution as well as the greatest distance from the negative-ideal solution 2. Deng’s Similarity based Approach where the most preferred alternative should have the highest degree of similarity to the positive ideal solution and the lowest degree of similarity to the negative-ideal solution and 3.PROMETHEE and GAIA. The solutions for each of these three cases were analyzed thoroughly, and reasons for any deviations were discussed.

  20. Plugin procedure in segmentation and application to hyperspectral image segmentation

    CERN Document Server

    Girard, R

    2010-01-01

    In this article we give our contribution to the problem of segmentation with plug-in procedures. We give general sufficient conditions under which plug in procedure are efficient. We also give an algorithm that satisfy these conditions. We give an application of the used algorithm to hyperspectral images segmentation. Hyperspectral images are images that have both spatial and spectral coherence with thousands of spectral bands on each pixel. In the proposed procedure we combine a reduction dimension technique and a spatial regularisation technique. This regularisation is based on the mixlet modelisation of Kolaczyck and Al.

  1. Segmentation of knee injury swelling on infrared images

    Science.gov (United States)

    Puentes, John; Langet, Hélène; Herry, Christophe; Frize, Monique

    2011-03-01

    Interpretation of medical infrared images is complex due to thermal noise, absence of texture, and small temperature differences in pathological zones. Acute inflammatory response is a characteristic symptom of some knee injuries like anterior cruciate ligament sprains, muscle or tendons strains, and meniscus tear. Whereas artificial coloring of the original grey level images may allow to visually assess the extent inflammation in the area, their automated segmentation remains a challenging problem. This paper presents a hybrid segmentation algorithm to evaluate the extent of inflammation after knee injury, in terms of temperature variations and surface shape. It is based on the intersection of rapid color segmentation and homogeneous region segmentation, to which a Laplacian of a Gaussian filter is applied. While rapid color segmentation enables to properly detect the observed core of swollen area, homogeneous region segmentation identifies possible inflammation zones, combining homogeneous grey level and hue area segmentation. The hybrid segmentation algorithm compares the potential inflammation regions partially detected by each method to identify overlapping areas. Noise filtering and edge segmentation are then applied to common zones in order to segment the swelling surfaces of the injury. Experimental results on images of a patient with anterior cruciate ligament sprain show the improved performance of the hybrid algorithm with respect to its separated components. The main contribution of this work is a meaningful automatic segmentation of abnormal skin temperature variations on infrared thermography images of knee injury swelling.

  2. Study of the variability in upper and lower airway morphology in Sprague-Dawley rats using modern micro-CT scan-based segmentation techniques.

    Science.gov (United States)

    De Backer, Jan W; Vos, Wim G; Burnell, Patricia; Verhulst, Stijn L; Salmon, Phil; De Clerck, Nora; De Backer, Wilfried

    2009-05-01

    Animal models are being used extensively in pre-clinical and safety assessment studies to assess the effectiveness and safety of new chemical entities and delivery systems. Although never entirely replacing the need for animal testing, the use of computer simulations could eventually reduce the amount of animals needed for research purposes and refine the data acquired from the animal studies. Computational fluid dynamics is a powerful tool that makes it possible to simulate flow and particle behavior in animal or patient-specific respiratory models, for purposes of inhaled delivery. This tool requires an accurate representation of the respiratory system, respiration and dose delivery attributes. The aim of this study is to develop a representative airway model of the Sprague-Dawley rat using static and dynamic micro-CT scans. The entire respiratory tract was modeled, from the snout and nares down to the central airways at the point where no distinction could be made between intraluminal air and the surrounding tissue. For the selection of the representative model, variables such as upper airway movement, segmentation length, airway volume and size are taken into account. Dynamic scans of the nostril region were used to illustrate the characteristic morphology of this region in anaesthetized animals. It could be concluded from this study that it was possible to construct a highly detailed representative model of a Sprague-Dawley rat based on imaging modalities such as micro-CT scans.

  3. A hybrid electron and photon IMRT planning technique that lowers normal tissue integral patient dose using standard hardware.

    Science.gov (United States)

    Rosca, Florin

    2012-06-01

    To present a mixed electron and photon IMRT planning technique using electron beams with an energy range of 6-22 MeV and standard hardware that minimizes integral dose to patients for targets as deep as 7.5 cm. Ten brain cases, two lung, a thyroid, an abdominal, and a parotid case were planned using two planning techniques: a photon-only IMRT (IMRT) versus a mixed modality treatment (E+IMRT) that includes an enface electron beam and a photon IMRT portion that ensures a uniform target coverage. The electron beam is delivered using a regular cutout placed in an electron cone. The electron energy was chosen to provide a good trade-off between minimizing integral dose and generating a uniform, deliverable plan. The authors choose electron energies that cover the deepest part of PTV with the 65%-70% isodose line. The normal tissue integral dose, the dose for ring structures around the PTV, and the volumes of the 75%, 50%, and 25% isosurfaces were used to compare the dose distributions generated by the two planning techniques. The normal tissue integral dose was lowered by about 20% by the E+IMRT plans compared to the photon-only IMRT ones for most studied cases. With the exception of lungs, the dose reduction associated to the E+IMRT plans was more pronounced further away from the target. The average dose ratio delivered to the 0-2 cm and the 2-4 cm ring structures for brain patients for the two planning techniques were 89.6% and 70.8%, respectively. The enhanced dose sparing away from the target for the brain patients can also be observed in the ratio of the 75%, 50%, and 25% isodose line volumes for the two techniques, which decreases from 85.5% to 72.6% and further to 65.1%, respectively. For lungs, the lateral electron beams used in the E+IMRT plans were perpendicular to the mostly anterior/posterior photon beams, generating much more conformal plans. The authors proved that even using the existing electron delivery hardware, a mixed electron/photon planning

  4. Simultaneous Segmentation and Statistical Label Fusion.

    Science.gov (United States)

    Asman, Andrew J; Landmana, Bennett A

    2012-02-23

    Labeling or segmentation of structures of interest in medical imaging plays an essential role in both clinical and scientific understanding. Two of the common techniques to obtain these labels are through either fully automated segmentation or through multi-atlas based segmentation and label fusion. Fully automated techniques often result in highly accurate segmentations but lack the robustness to be viable in many cases. On the other hand, label fusion techniques are often extremely robust, but lack the accuracy of automated algorithms for specific classes of problems. Herein, we propose to perform simultaneous automated segmentation and statistical label fusion through the reformulation of a generative model to include a linkage structure that explicitly estimates the complex global relationships between labels and intensities. These relationships are inferred from the atlas labels and intensities and applied to the target using a non-parametric approach. The novelty of this approach lies in the combination of previously exclusive techniques and attempts to combine the accuracy benefits of automated segmentation with the robustness of a multi-atlas based approach. The accuracy benefits of this simultaneous approach are assessed using a multi-label multi- atlas whole-brain segmentation experiment and the segmentation of the highly variable thyroid on computed tomography images. The results demonstrate that this technique has major benefits for certain types of problems and has the potential to provide a paradigm shift in which the lines between statistical label fusion and automated segmentation are dramatically blurred.

  5. SEGMENTAL FRACTURE OF PROXIMAL SHAFT FEMUR OF POLIO AFFECTED PARALYTIC LIMB TREATED WITH 95 DEGREE ANGLED PLATE FIXATION BY MIPO TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Rajan

    2014-11-01

    Full Text Available Subtrochanteric fractures extending below lesser trochanter are always difficult to treat and their higher incidence of unsatisfactory results are noted after operative treatment. There are various implants available for fixation but in this study we did 95 DEG ANGLED PLATE FIXATION BY MIPO TECHNIQUE

  6. Modeling the structure and absorption spectra of stilbazolium merocyanine in polar and nonpolar solvents using hybrid QM/MM techniques.

    Science.gov (United States)

    Murugan, N Arul; Kongsted, Jacob; Rinkevicius, Zilvinas; Aidas, Kestutis; Ågren, Hans

    2010-10-28

    We have performed Car-Parrinello mixed quantum mechanics/molecular mechanics (CP-QM/MM) calculations for stilbazolium merocyanine (SM) in polar and nonpolar solvents in order to explore the role of solute molecular geometry, solvation shell structure, and different interaction mechanisms on the absorption spectra and its dependence on solvent polarity. On the basis of the average bond length values and group charge distributions, we find that the SM molecule remains in a neutral quinonoid form in chloroform (a nonpolar solvent) while it transforms to a charge-separated benzenoid form in water (a polar solvent). Based on a quantum mechanical/molecular mechanical response technique, with different MM descriptions for the water environment, absorption spectra were obtained as averages over configurations derived from the CP-QM/MM simulations. We show that for SM in water the solute polarization plays a major role in predictions of the λ(max) and solvatochromic shift and that once this effect is included the contributions from solvent polarization and intermolecular charge transfer become less important. For SM in chloroform and water solvents, we have also performed absorption spectra calculations using a polarizable continuum model in order to address its relative performance compared to the QM/MM response technique. In the case of SM in water, our study supports the notion that, in order to predict accurate absorption spectra and solvatochromic shifts, it is important to use a discrete description of the solvent when it, as in water, is involved in site-specific interaction with the solute molecule. The technique is thus shown to outperform the more conventional polarizable continuum model in predicting the solvatochromic shift.

  7. 基于竞选算法的图像多阈值分割技术%Multilevel Thresholding Segmentation Technique Based on Election Campaign Optimization Algorithm

    Institute of Scientific and Technical Information of China (English)

    涂叙安; 吕文阁

    2016-01-01

    This paper presents a method to get the optimal threshold based on gray-level histogram transform, using the election campaign algorithm as the basis of rapid search the global optimal threshold algorithm. First,select multiple grey value for a group divided gray-level histogram into several parts, this histograms synthesized normal distribution function and multiplied by their weights, add them as a new distribution function. after that,the new function and the original histogram are normalized respectively and in the solution space solving the absolute value of difference between them,the smallest set of grey value as the image segmentation thresholds.%提出了一种基于灰度直方图变换求解最佳阈值的方法,采用竞选算法作为快速搜索全局最优阈值的基础算法。首先,选取多个灰度值为一组,将整个灰度直方图分割成几部分,分别对这些直方图拟合成正态分布函数后加权相加合成一个新的分布函数,然后,将优化分布函数与原直方图分别归一化处理,在解空间内求解它们差值的绝对值的和,取和值最小的那组灰度值作为图像的分割阈值。

  8. Empleo de la técnica hibridación in situ fluorescente para visualizar microorganismos Use of fluorescence in situ hybridization technique to visualize microorganisms

    Directory of Open Access Journals (Sweden)

    Raúl Rodríguez Martínez

    2011-12-01

    Full Text Available La hibridación in situ fluorescente (FISH, es una técnica que emplea sondas de oligonucleótidos marcadas con fluorocromos las cuales van dirigidas hacia secuencias específicas del ácido ribonucleico ribosomal (ARNr, lo que permite la identificación rápida y específica de células microbianas ya sea que estén como células individuales o se encuentren agrupadas en su ambiente natural. El conocimiento de la composición y distribución de los microorganismos en los hábitats naturales, proporciona un soporte sólido para comprender la interacción entre las diversas especies que componen el micro hábitat. El objetivo de la revisión es presentar la forma como ha evolucionado la hibridación, el empleo del ARNr como molécula diana, los tipos de marcaje, los marcadores fluorescentes empleados hoy en día, la metodología, así como las mejoras que se le han hecho a la técnica FISH al emplearse en conjunto con otras técnicas en la identificación microbiana. Salud UIS 2011; 43 (3: 307-316Fluorescence in situ hybridization (FISH, is a technique that uses oligonucleotides probes labeled with fluorochromes which are directed to specific sequences of ribosomal ribonucleic acid (rRNA, this allows the rapid and specific identification of microbial cells whether as individual cells or grouped cells in their natural environment. Knowledge of the composition and distribution of microorganisms in natural habitats provides a solid support to understand interaction between different species in the microhabitat. This review shows how hybridization has evolved, the use of rRNA as target molecule, the type of labeling, the labeled uses today in fluorescent and the methodology, as well as the improvements that have been made to the FISH technique when is used in conjunction with other techniques in microbial identification. Salud UIS 2011; 43 (3: 307-316

  9. Transactivating effect of complete S protein of hepatitis B virus and cloning of genes transactivated by complete S protein using suppression subtractive hybridization technique

    Institute of Scientific and Technical Information of China (English)

    Gui-Qin Bai; Yan Liu; Jun Cheng; Shu-Lin Zhang; Ya-Fei Yue; Yan-Ping Huang; Li-Ying Zhang

    2005-01-01

    AIM: To investigate the transactivating effect of complete S protein of hepatitis B virus (HBV) and to construct a subtractive cDNA library of genes transactivated by complete S protein of HBV by suppression subtractive hybridization (SSH) technique and to clone genes associated with its transactivation activity, and to pave the way for elucidating the pathogenesis of hepatitis B virus infection.METHODS: pcDNA3.1(-)-complete S containing full-length HBV S gene was constructed by insertion of HBV complete S gene into BarmH-I/Kpn I sites. HepG2 cells were cotransfected with pcDNA3.1(-)-complete S and pSV-lacZ.After 48 h, cells were collected and detected for the expression of β-galactosidase (β-gal). Suppression subtractive hybridization and bioinformatics techniques were used.The mRNA of HepG2 cells transfected with pcDNA3.1(-)-complete S and pcDNA3.1(-) empty vector was isolated,and detected for the expression of complete S protein by reverse transcription polymerase chain reaction (RT-PCR)method, and cDNA was synthesized. After digestion with restriction enzyme RcaI, cDNA fragments were obtained.Tester cDNA was then divided into two groups and ligated to the specific adaptors 1 and 2, respectively. After tester cDNA had been hybridized with driver cDNA twice and underwent nested PCR twice, amplified cDNA fragments were subcloned into pGEM-Teasy vectors to set up the subtractive library. Amplification of the library was carried out within E. coli strain DH5α. The cDNA was sequenced and analyzed in GenBank with BLAST search after polymerase chain reaction (PCR) amplification.RESULTS: The complete S mRNA could be detected by RT-PCR in HepG2 cells transfected with the pcDNA3.1(-)-complete S. The activity of β-gal in HepG2 cells transfected with the pcDNA3.1(-)-complete S was 6.9 times higher than that of control plasmid. The subtractive library of genes transactivated by HBV complete S protein was constructed successfully. The amplified library contains 86

  10. Hybrid and Etch-Less Electrooptic Waveguide Modulator Based on Photo-Bleaching and Strain Induced Optical Waveguide Technique in Polymer.

    Science.gov (United States)

    Kim, Richard; Kang, Byeong-Mo; Jeong, Woon-Jo; Jung, Yang-June; Park, Hyuk-Reol; Kim, Chang-Dae; So, Soon-Youl; Lee, Jin; Park, Gye-Choon; Park, Yongjun

    2016-02-01

    A hybrid and etchless electrooptic (EO) polymer waveguide modulator based on both a photo-bleaching-induced optical waveguide (PBOW) and a strain-induced optical waveguide (SIOW) is described. The SIOW is defined by a metal strip line stressor deposited on top of the upper cladding that introduces the refractive index change within the core region. The PBOW technique is used to form an optical waveguide which is based on a photo-bleaching process, known as a photo-oxidation that is an irreversible decomposition of EO material, resulting in a permanent decrease in index of refraction. It is shown that this proposed fabrication idea combining two etchless techniques can be applicable to a wide range of polymer photonic integrated circuits. Preliminary results obtained from fabricated devices reveal that their half-wave voltage are ranging from 8 V to 10 V, their extinction ratio exhibits more than 15 dB, and the fiber-to-waveguide-to-lens loss is estimated to be ~9.5 dB for TM polarization at 1.55/m wavelength in the active interaction of ~1.5 cm long.

  11. Ranking factors involved in product design using a hybrid model of Quality Function Deployment, Data Envelopment Analysis and TOPSIS technique

    Directory of Open Access Journals (Sweden)

    Davood Feiz

    2014-08-01

    Full Text Available Quality function deployment (QFD is one such extremely important quality management tool, which is useful in product design and development. Traditionally, QFD rates the design requirements (DRs with respect to customer requirements, and aggregates the rating to get relative importance score of DRs. An increasing number of studies emphasize on the need to incorporate additional factors, such as cost and environmental impact, while calculating the relative importance of DRs. However, there are different methodologies for driving the relative importance of DRs, when several additional factors are considered. TOPSIS (technique for order preferences by similarity to ideal solution is suggested for the purpose of the research. This research proposes new approach of TOPSIS for considering the rating of DRs with respect to CRs, and several additional factors, simultaneously. Proposed method is illustrated using by step-by-step procedure. The proposed methodology was applied for the Sanam Electronic Company in Iran.

  12. Novel preparation of controlled porosity particle/fibre loaded scaffolds using a hybrid micro-fluidic and electrohydrodynamic technique.

    Science.gov (United States)

    Parhizkar, Maryam; Sofokleous, Panagiotis; Stride, Eleanor; Edirisinghe, Mohan

    2014-11-27

    The purpose of this research was to produce multi-dimensional scaffolds containing biocompatible particles and fibres. To achieve this, two techniques were combined and used: T-Junction microfluidics and electrohydrodynamic (EHD) processing. The former was used to form layers of monodispersed bovine serum albumin (BSA) bubbles, which upon drying formed porous scaffolds. By altering the T-Junction processing parameters, bubbles with different diameters were produced and hence the scaffold porosity could be controlled. EHD processing was used to spray or spin poly(lactic-co-glycolic) (PLGA), polymethysilsesquioxane (PMSQ) and collagen particles/fibres onto the scaffolds during their production and after drying. As a result, multifunctional BSA scaffolds with controlled porosity containing PLGA, PMSQ and collagen particles/fibres were obtained. Product morphology was studied by optical and scanning electron microscopy. These products have potential applications in many advanced biomedical, pharmaceutical and cosmetic fields e.g. bone regeneration, drug delivery, cosmetic cream lathers, facial scrubbing creams etc.

  13. A Hybrid Reliable Data Transmission based on Ant-agent Resource Allocation Technique in EEMCC Protocol for MANETS

    Directory of Open Access Journals (Sweden)

    Dr. M. Rajanbabu

    2014-04-01

    Full Text Available Real time multicast applications in mobile adhoc network brings forward added advantages in wireless network. The fragile and mobile environment of adhoc network produces the need of bandwidth allocation for real time applications. Reliability is also an important factor in multicasting in mobile adhoc networks (MANETs, as it confirms eventual delivery of all the data to all the group members, without enforcing any particular delivery order in EEMCCP. In the first phase of this paper, we design an "ant agent-resource allocation‟ technique for reserving bandwidth for real-time multicast applications. In the forward phase, the source sends a forward ant agent which collects the bandwidth information of intermediate nodes and reserves a bandwidth for real-time flow for each multicast receiver. In the backward phase, the backward ant confirms the allocation and feeds the bandwidth information to the source.

  14. Cytogenetic analysis from DNA by comparative genomic hybridization.

    Science.gov (United States)

    Tachdjian, G; Aboura, A; Lapierre, J M; Viguié, F

    2000-01-01

    Comparative genomic hybridization (CGH) is a modified in situ hybridization technique which allows detection and mapping of DNA sequence copy differences between two genomes in a single experiment. In CGH analysis, two differentially labelled genomic DNA (study and reference) are co-hybridized to normal metaphase spreads. Chromosomal locations of copy number changes in the DNA segments of the study genome are revealed by a variable fluorescence intensity ratio along each target chromosome. Since its development, CGH has been applied mostly as a research tool in the field of cancer cytogenetics to identify genetic changes in many previously unknown regions. CGH may also have a role in clinical cytogenetics for detection and identification of unbalanced chromosomal abnormalities.

  15. Hybrid technique for DeBakey type Ⅰ aortic dissection%DeBakeyⅠ型主动脉夹层的杂交手术治疗

    Institute of Scientific and Technical Information of China (English)

    郑先杰; 郭大乔; 张双林; 张庄; 赵爱国; 张国瑜; 张筱扬; 董彦军; 段淑敏; 符伟国

    2010-01-01

    Objective To explore the efficacy,indication and the treatment of complication of concomitant thoracic aortic replacement and endoluminal stent grafting (hybrid technique) for DeBakey type Ⅰ aortic dissection. Methods From September 2005 to June 2009,12 patients with acute DeBakey type Ⅰ aortic dissection were diagnosed by contrast-enhanced CT or MRI scan, and underwent hybrid technique.Computed tomography angiography (CTA) was performed in each patient at 2,6 months after operation to check up the post-operative course,such as ascending aortic and vascular prosthesis of aortic arch and decending aorta. The time of the post-operational follow-up was 6 -36 months. Results All patients successfully recovered from surgery procedure,no serious complication. The time of cardiopulmonary bypass was 196 -298 (264.0 ± 36.6) min,arrest time of ascending aortic was 89 -276 (213.6 ±43.8) min. All patients were discharged from hospital. Contrast-enhanced CT or MRI indicated the vascular prosthesis to been unobstructed,no endo-stent dislocation and no organ ischemia, the false lumen and thrombosis disappeared in 10 patients,but false lumen and leakage happened in 2 patients at 2 months after operation.The false lumen disappeared at 6 months after operation. Conclusions Hybrid technique for DeBakey type Ⅰ aortic dissection is satisfactory in short term effect with less invasiveness and definite safety. However,further studies are needed to evaluate its long-term outcomes.%目的 探讨DeBakey Ⅰ型主动脉夹层行升主动脉并全弓置换加降主动脉支架置入术(即杂交手术)的疗效、适应证的选择和并发症的处理.方法 2005年9月至2009年6月,经CT增强扫描或磁共振确诊DeBakey Ⅰ型主动脉夹层患者12例,均行杂交手术.术后2、6个月复查胸部CT增强扫描,了解升主动脉、主动脉弓人工血管及降主动脉血管内覆膜支架的情况.结果 12例患者全部手术成功,无严

  16. Improving the prediction of going concern of Taiwanese listed companies using a hybrid of LASSO with data mining techniques.

    Science.gov (United States)

    Goo, Yeung-Ja James; Chi, Der-Jang; Shen, Zong-De

    2016-01-01

    The purpose of this study is to establish rigorous and reliable going concern doubt (GCD) prediction models. This study first uses the least absolute shrinkage and selection operator (LASSO) to select variables and then applies data mining techniques to establish prediction models, such as neural network (NN), classification and regression tree (CART), and support vector machine (SVM). The samples of this study include 48 GCD listed companies and 124 NGCD (non-GCD) listed companies from 2002 to 2013 in the TEJ database. We conduct fivefold cross validation in order to identify the prediction accuracy. According to the empirical results, the prediction accuracy of the LASSO-NN model is 88.96 % (Type I error rate is 12.22 %; Type II error rate is 7.50 %), the prediction accuracy of the LASSO-CART model is 88.75 % (Type I error rate is 13.61 %; Type II error rate is 14.17 %), and the prediction accuracy of the LASSO-SVM model is 89.79 % (Type I error rate is 10.00 %; Type II error rate is 15.83 %).

  17. Strategic market segmentation

    National Research Council Canada - National Science Library

    Maričić Branko R; Đorđević Aleksandar

    2015-01-01

    ..., 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...

  18. A comparative study on medical image segmentation methods

    Directory of Open Access Journals (Sweden)

    Praylin Selva Blessy SELVARAJ ASSLEY

    2014-03-01

    Full Text Available Image segmentation plays an important role in medical images. It has been a relevant research area in computer vision and image analysis. Many segmentation algorithms have been proposed for medical images. This paper makes a review on segmentation methods for medical images. In this survey, segmentation methods are divided into five categories: region based, boundary based, model based, hybrid based and atlas based. The five different categories with their principle ideas, advantages and disadvantages in segmenting different medical images are discussed.

  19. Visceral hybrid reconstruction of thoracoabdominal aortic aneurysm after open repair of type a aortic dissection by the Bentall procedure with the elephant trunk technique: A case report

    Directory of Open Access Journals (Sweden)

    Marjanović Ivan

    2014-01-01

    Full Text Available Introduction. Reconstruction of chronic type B dissection and thoracoabdominal aortic aneurysm (TAAA remaining after the emergency reconstruction of the ascending thoracic aorta and aortic arch for acute type A dissection represents one of the major surgical challenges. Complications of chronic type B dissection are aneurysmal formation and rupture of an aortic aneurysm with a high mortality rate. We presented a case of visceral hybrid reconstruction of TAAA secondary to chronic dissection type B after the Bentall procedure with the elephant trunk technique due to acute type A aortic dissection in a high-risk patient. Case report. A 62 year-old woman was admitted to our institution for reconstruction of Crawford type I TAAA secondary to chronic dissection. The patient had had an acute type A aortic dissection 3 years before and undergone reconstruction by the Bentall procedure with the elephant trunk technique with valve replacement. On admission the patient had coronary artery disease (myocardial infarction, two times in the past 3 years, congestive heart disease with ejection fraction of 25% and chronic obstructive pulmonary disease. On computed tomography (CT of the aorta TAAA was revealed with a maximum diameter of 93 mm in the descending thoracic aorta secondary to chronic dissection. All the visceral arteries originated from the true lumen with exception of the celiac artery (CA, and the end of chronic dissection was below the origin of the superior mesenteric artery (SMA. The patient was operated on using surgical visceral reconstruction of the SMA, CA and the right renal artery (RRA as the first procedure. Postoperative course was without complications. Endovascular TAAA reconstruction was performed as the second procedure one month later, when the elephant trunk was used as the proximal landing zone for the endograft, and distal landing zone was the level of origin of the RRA. Postoperatively, the patient had no neurological deficit and

  20. Comparison of pure and hybrid iterative reconstruction techniques with conventional filtered back projection: Image quality assessment in the cervicothoracic region

    Energy Technology Data Exchange (ETDEWEB)

    Katsura, Masaki, E-mail: mkatsura-tky@umin.ac.jp [Department of Radiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan); Sato, Jiro; Akahane, Masaaki; Matsuda, Izuru; Ishida, Masanori; Yasaka, Koichiro; Kunimatsu, Akira; Ohtomo, Kuni [Department of Radiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan)

    2013-02-15

    Objectives: To evaluate the impact on image quality of three different image reconstruction techniques in the cervicothoracic region: model-based iterative reconstruction (MBIR), adaptive statistical iterative reconstruction (ASIR), and filtered back projection (FBP). Methods: Forty-four patients underwent unenhanced standard-of-care clinical computed tomography (CT) examinations which included the cervicothoracic region with a 64-row multidetector CT scanner. Images were reconstructed with FBP, 50% ASIR-FBP blending (ASIR50), and MBIR. Two radiologists assessed the cervicothoracic region in a blinded manner for streak artifacts, pixilated blotchy appearances, critical reproduction of visually sharp anatomical structures (thyroid gland, common carotid artery, and esophagus), and overall diagnostic acceptability. Objective image noise was measured in the internal jugular vein. Data were analyzed using the sign test and pair-wise Student's t-test. Results: MBIR images had significant lower quantitative image noise (8.88 ± 1.32) compared to ASIR images (18.63 ± 4.19, P < 0.01) and FBP images (26.52 ± 5.8, P < 0.01). Significant improvements in streak artifacts of the cervicothoracic region were observed with the use of MBIR (P < 0.001 each for MBIR vs. the other two image data sets for both readers), while no significant difference was observed between ASIR and FBP (P > 0.9 for ASIR vs. FBP for both readers). MBIR images were all diagnostically acceptable. Unique features of MBIR images included pixilated blotchy appearances, which did not adversely affect diagnostic acceptability. Conclusions: MBIR significantly improves image noise and streak artifacts of the cervicothoracic region over ASIR and FBP. MBIR is expected to enhance the value of CT examinations for areas where image noise and streak artifacts are problematic.